Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/10/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
304 PM CDT SAT AUG 8 2015
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
A FEW ISOLATED SHOWERS AND THUNDERSTORMS HAVE POPPED UP ACROSS THE
STATE DURING THE LAST COUPLE OF HOURS AND THESE HAVE BEEN EXTREMELY
ISOLATED IN NATURE. WITH A STALLED BOUNDARY ACROSS THE STATE...DO
EXPECT A FEW MORE SHOWERS AND THUNDERSTORMS TO POP UP IN THE HEAT OF
THE DAY...WHICH THE HRRR HAS BEEN CONSISTENT IN SHOWING AS WELL.
SUNDAY WILL BE SLIGHTLY HOTTER AS THE RIDGE BUILDS INTO THE
AREA...THE AXIS OF HIGHEST DEW POINTS WILL SHIFT A BIT MORE TO THE
EAST. AS A RESULT...THIS WILL ADD NE ARKANSAS INTO THE HEAT ADVISORY.
A HOT DAY CAN BE EXPECTED ON MONDAY AS WELL WITH SLIGHTLY LOWER DEW
POINTS. AT THIS POINT IT APPEARS THE ONLY AREAS ABLE TO REACH
EXCESSIVE HEAT WARNING CRITERIA WILL BE ACROSS SE PORTIONS OF THE
CWA...BUT AT THIS POINT ITS BORDERLINE. WILL DEFER TO THE MID
SHIFT...AS THE NUMBERS ARE SO CLOSE TO CRITERIA. A FRONT WILL MOVE
THROUGH THE STATE ON MONDAY...WITH LITTLE IN THE WAY OF
PRECIPITATION EXPECTED UNTIL THE FRONT REACHES SOUTHERN ARKANSAS. IT
CONTINUES TO LOOK THAT THE BEST CHANCES FOR PRECIPITATION WILL BE TO
THE SOUTH OF THE STATE...BUT DID GO AND INCLUDE SLIGHT CHANCE POPS
ACROSS SOUTHERN PORTIONS OF THE STATE.
&&
.LONG TERM...WEDNESDAY THROUGH FRIDAY
SOME EXCESSIVE HEAT RELIEF IS IN STORE BEGINNING WEDNESDAY. AS
THE UPPER RIDGE SHIFTS WEST ALLOWING AND IN THE WAKE OF A WEAK
COLD FRONT MAX TEMPS DURING THIS PERIOD WILL RUN AT OR BELOW
NORMAL. DRIER CONDITIONS AS WELL AS DEWPOINTS FALL INTO THE UPPER
50S TO MID 60S. LOOKS TO BE A DRY PERIOD AS STABLE NORTHERLY FLOW
ALOFT AND WEAK NE SURFACE FLOW DOMINATE AND EMBEDDED UPPER LEVEL
DISTURBANCES SEEM UNLIKELY AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 92 74 99 79 / 10 0 0 10
CAMDEN AR 103 77 104 78 / 20 0 0 10
HARRISON AR 94 74 97 74 / 20 0 0 10
HOT SPRINGS AR 102 78 103 78 / 20 0 0 10
LITTLE ROCK AR 100 77 103 80 / 10 0 0 10
MONTICELLO AR 102 77 103 80 / 10 0 0 10
MOUNT IDA AR 102 75 102 74 / 20 0 0 10
MOUNTAIN HOME AR 93 74 98 75 / 20 0 0 10
NEWPORT AR 92 73 98 77 / 10 0 0 10
PINE BLUFF AR 100 76 103 78 / 10 0 0 10
RUSSELLVILLE AR 99 76 101 75 / 20 0 0 10
SEARCY AR 95 73 100 76 / 10 0 0 10
STUTTGART AR 96 75 101 77 / 10 0 0 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BAXTER-BOONE-
CLEBURNE-INDEPENDENCE-JACKSON-MARION-MONROE-NEWTON-SEARCY-STONE-
VAN BUREN-WOODRUFF.
HEAT ADVISORY FROM 11 AM TO 8 PM CDT SUNDAY FOR BAXTER-BOONE-
CLEBURNE-FULTON-INDEPENDENCE-IZARD-JACKSON-MARION-NEWTON-SEARCY-
SHARP-STONE-VAN BUREN.
EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR ARKANSAS-
BRADLEY-CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-
PULASKI-SALINE-SCOTT-WHITE-YELL.
EXCESSIVE HEAT WARNING FROM 11 AM TO 8 PM CDT SUNDAY FOR
ARKANSAS-BRADLEY-CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-
DREW-FAULKNER-GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-
PRAIRIE-PULASKI-SALINE-SCOTT-WHITE-WOODRUFF-YELL.
HEAT ADVISORY FROM 11 AM TO 8 PM CDT MONDAY FOR ARKANSAS-BRADLEY-
CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-JACKSON-JEFFERSON-JOHNSON-
LINCOLN-LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.
&&
$$
SHORT TERM...65 / LONG TERM...32
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
1245 AM CDT SAT 8 2015
.AVIATION...
OVERALL VFR FLIGHT CONDITIONS ARE EXPECTED OVERNIGHT...ALTHOUGH
PATCHY MVFR CEILINGS WILL BE SEEN...ESPECIALLY OVER NORTHERN AR.
SOME FOG WILL ALSO BE POSSIBLE WITH SCATTERED MVFR CONDITIONS. A
WEAK AND STALLED FRONTAL BOUNDARY WILL SPLIT THE STATE...WITH WINDS
NE TO E AT 3 TO 8 MPH OVER NORTHERN TO CENTRAL AR...WHILE S TO SW 3
TO 8 MPH OVER SOUTHERN AR. AN ISOLATED SHOWER OR THUNDERSTORM MAY BE
SEEN...BUT CONFIDENCE IS LOW AND DID NOT INCLUDE IN TAFS. SATURDAY
WILL SEE VFR CONDITIONS WITH OVERALL DRY WEATHER.
&&
.PREV DISCUSSION... /ISSUED 957 PM CDT FRI AUG 7 2015/
.UPDATE...
SFC DATA INDC THAT THE QUASI-STATIONARY BNDRY BISECTED THE FA
ALONG THE AR RVR THIS EVENING. SFC DEWPOINTS CONT TO POOL ALONG
AND N OF THE BNDRY...WHERE READINGS ARE HOVERING ARND 80F. AIRMASS
RMNS VERY UNSTABLE IN THIS SECTOR AS WELL...WITH 08/00Z KLZK RAOB
SHOWING SBCAPE APCHG 6K J/KG WITH LTL IN THE WAY OF CINH.
STARTING TO SEE SOME SCTD CONVECTION DVLP OVR FAR ERN AR ATTM. THE
RAPID UPDATE MODEL DATA CONT TO INDC SCTD CONVECTION FORMING
FURTHER NWWD INTO PARTS OF NERN AR LATE THIS EVENING INTO THE
OVERNIGHT HOURS. PLAN TO KEEP SLGT CHC POPS IN PLACE PER GOING
FCST AND WL CONT TO MONITOR RADAR/MODEL TRENDS.
THUS...NO SIG CHGS WERE MADE TO THE CURRENT FCST. JUST UPDATED
HRLY TEMPS TO ACCOUNT FOR LATEST TRENDS. ALL UPDATES OUT. /44/
&&
PREV DISCUSSION... /ISSUED 239 PM CDT FRI AUG 7 2015/
SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
AN AREA OF SHOWERS AND THUNDERSTORMS MOVED FROM SOUTH CENTRAL
MISSOURI AND TRACKED SOUTHEAST THROUGH PORTIONS OF EASTERN ARKANSAS.
THESE STORMS CONTINUED TO STRENGTHEN DURING THE MID MORNING HOURS
AND LED TO INCREASED CLOUD COVER THROUGH THE EASTERN HALF OF THE
STATE. BY THE EARLY AFTERNOON HOURS...MOSTLY SUNNY SKIES WERE SEEN
AROUND THE STATE WITH TEMPERATURES WARMING INTO THE MID TO UPPER 90S
WITH A FEW LOCATIONS IN WESTERN ARKANSAS ALREADY TOPPING 100
DEGREES. HEAT INDICES AROUND THE STATE HAVE REACHED 112 AT
RUSSELLVILLE WITH A FEW LOCATIONS TOPPING 110.
FOR TONIGHT...KEPT SLIGHT CHANCE POPS ACROSS EASTERN PORTIONS OF THE
AREA WITH BOTH THE HRRR AND WRF SHOWING REDEVELOPMENT ACROSS EASTERN
ARKANSAS.
IN THE COMING DAYS...WILL CONTINUE TO SEE A STRONG RIDGE OF HIGH
PRESSURE BUILD INTO THE REGION WITH TEMPERATURES EXPECTED TO CLIMB
EVEN HOTTER THAN WHAT HAS BEEN SEEN TODAY. FOR NOW...HAVE EXTENDED
AND EXPANDED THE EXCESSIVE HEAT WARNING INTO SATURDAY AND CONTINUED
WITH THE HEAT ADVISORY AT THE REMAINING COUNTIES EXCEPT ACROSS
NORTHEAST ARKANSAS.
HOT TEMPERATURES WILL CONTINUE ON SUNDAY WITH FEWER CLOUDS AND
SLIGHTLY LOWER DEWPOINTS...GENERALLY ACROSS SOUTHWEST AND CENTRAL
ARKANSAS. HOWEVER DEWPOINTS WILL GENERALLY INCREASE ACROSS NORTHEAST
ARKANSAS WHICH WILL LIKELY CAUSE HEAT ADVISORIES/WARNINGS TO BE
EXTENDED AND EXPANDED.
UPPER LEVEL RIDGE WILL BEGIN TO RETREAT ON MONDAY...ALLOWING A COLD
FRONT TO APPROACH THE STATE FROM THE NORTH. AT THIS POINT...IT DOES
NOT APPEAR THAT THERE WILL BE HIGH CHANCE FOR PRECIPITATION WITH
THIS FRONT...BUT SLIGHTLY COOLER TEMPS AND DRIER AIR WILL MOVE INTO
THE STATE FOR THE LONG TERM.
LONG TERM...TUESDAY THROUGH FRIDAY NIGHT
THE UPPER LEVEL RIDGE OF HIGH PRESSURE THAT HAS PERSISTED OVER THE
REGION FOR THE PAST SEVERAL WEEKS WILL RETREAT WESTARD DURING THE
EXTENDED TERM...CHANGING THE UPPER LEVEL FLOW PATTERN TO A
NORTHERLY TO NORTHWESTERLY FLOW. AT THE SURFACE A HIGH PRESSURE
SYSTEM WILL SLOWLY MOVE TO THE EAST ACROSS THE UPPER MIDWEST INTO
THE OHIO VALLEY...KEEPING THE FORECAST AREA ALONG THE SOUTHERN
PERIPHERY OF THE HIGH. THIS WILL RESULT IN A DRY NORTHERLY TO
NORTHEASTERLY SURFACE FLOW.
THIS SETUP WILL ALLOW TEMPERATURES TO REMAIN JUST A BIT COOLER THAN
THEY HAVE BEEN AT PRESENT...MOST NOTABLY ACROSS THE NORTHERN HALF OF
THE AREA. SURFACE DEWPOINTS WILL EVENTUALLY DROP DOWN TO BE ABOUT 10
TO 15 DEGREES LOWER THAN THEY ARE RIGHT NOW...WHICH WILL BE A
WELCOME RELIEF...PUSHING MAXIMUM APPARENT TEMPERATURES DOWN INTO THE
MID 80S ACROSS THE NORTH TO THE MID 90S ACROSS THE SOUTH.
WITH THE NORTH TO NORTHWESTERLY FLOW AT THE UPPER LEVELS...A
SHORTWAVE OR TWO COULD RIPPLE ACROSS THE FORECAST AREA DURING THE
EXTENDED TERM...AND ISOLATED SHOWERS AND THUNDERSTORMS CANNOT BE
RULED OUT. HOWEVER...WITH THE MOISTURE LEVELS REMAINING LOWER...THE
CHANCES FOR PRECIPITATION SHOULD BE RATHER LOW...AND BELOW MENTION
IN MANY AREAS.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM 7 AM SATURDAY TO 7 PM CDT SUNDAY FOR BAXTER-
BOONE-INDEPENDENCE-JACKSON-MARION-NEWTON-SEARCY-STONE.
EXCESSIVE HEAT WARNING UNTIL 7 PM CDT SATURDAY FOR BRADLEY-
CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-FAULKNER-
GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-LOGAN-LONOKE-
OUACHITA-PERRY-POPE-PULASKI-SALINE-YELL.
EXCESSIVE HEAT WARNING FROM 7 AM TO 7 PM CDT SATURDAY FOR
ARKANSAS-MONTGOMERY-PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR ARKANSAS-MONTGOMERY-
PIKE-POLK-PRAIRIE-SCOTT-WHITE.
HEAT ADVISORY UNTIL 7 PM CDT SUNDAY FOR CLEBURNE-MONROE-VAN
BUREN-WOODRUFF.
&&
$$
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
245 PM MST SAT AUG 8 2015
.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...
&&
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EAST OF PHOENIX
TONIGHT...BUT STORM CHANCES WILL WANE ACROSS THE ENTIRE AREA ON
SUNDAY AS DRIER AIR MOVES INTO THE AREA. A RETURN TO A MORE TYPICAL
MONSOON FLOW IS EXPECTED BY THE MIDDLE OF NEXT WEEK...ALTHOUGH DRIER
AIR IS ONCE AGAIN FORECAST TO OVERSPREAD THE AREA BY THE END OF THE
WEEK.
&&
.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WELL-DEFINED SOUTHWESTERLY FLOW IN
THE 850 TO 300 MB LAYER BETWEEN A LOW PRESSURE SYSTEM ACROSS THE
NORTHERN ROCKIES AND AN ANTICYCLONE ACROSS TX. DRIER AIR CONTINUES TO
OVERSPREAD THE AREA AND IS MOST PRONOUNCED FURTHER WEST. AT THE
SURFACE...DEWPOINTS REMAIN ELEVATED IN THE WAKE OF YESTERDAY`S
RAINFALL...AND ARE AS HIGH AS MID TO UPPER 60S ACROSS THE PHOENIX
AREA.
LATEST SATELLITE IMAGERY AND REGIONAL WEBCAMS INDICATE THAT CU IS
STRUGGLING TO DEVELOP VERTICALLY ACROSS THE LOWER DESERTS. THIS IS
LIKELY DUE TO DRY AIR IN THE 850-750 MB LAYER AND A WARM BULGE
AROUND 700 MB EVIDENT IN SEVERAL ACARS PHX SOUNDINGS. LATEST
MESOANALYSIS IS THEREFORE LIKELY OVERESTIMATING INSTABILITY ACROSS
CENTRAL AZ. LATEST RUNS OF THE HRRR CONTINUE TO INITIATE CONVECTION
TOO EARLY AND SUBSEQUENTLY DELAY THE ONSET OF ISOLATED SHOWERS AND
THUNDERSTORMS LATER IN THE AFTERNOON.
A SLIGHT CHANCE OF THUNDERSTORMS WILL PERSIST INTO THIS
EVENING...THOUGH THE BEST CHANCE WILL MAINLY BE CONFINED TO THE
HIGHER TERRAIN EAST OF PHOENIX IN THE VICINITY OF THE DEEPER
MOISTURE. CONSENSUS OF THE LATEST LOCAL/NCEP/U OF AZ WRFS ALSO
SUGGEST NEGLIGIBLE CHANCES OF RAINFALL OR THUNDERSTORM-RELATED
IMPACTS THROUGH THIS EVENING.
&&
.PREVIOUS DISCUSSION...
DRIER AIR WILL ALMOST CERTAINLY OVERSPREAD THE ENTIRE AREA BY LATE
TONIGHT...EFFECTIVELY PUTTING THE BRAKES ON WIDESPREAD MONSOON
CONVECTION FOR THE NEXT SEVERAL DAYS. WHILE THERE WILL BE SMALL
POCKETS OF MOISTURE IN THE MOUNTAINS EAST OF PHOENIX...INSTABILITY
AND A SUFFICIENT TRIGGER APPEAR TO BE LACKING.
A RETURN TO A MORE TYPICAL MONSOON PATTERN IS EXPECTED BY
TUESDAY/WEDNESDAY AND THIS MORNING`S GFS AND ECMWF /AND ENSEMBLES/
SUGGEST AN IMPRESSIVE INCREASE IN MOISTURE. NOT ONLY THAT...BUT THEY
ALSO DEPICT A FAST MOVING 250-300MV PV ANOMALY IN THE AREA TUESDAY
AFTERNOON. INHERITED FORECAST DEPICTED ELEVATED POPS AND I SEE NO
REASON TO REVERSE THIS THINKING. WITH MOISTURE FORECAST TO REMAIN IN
PLACE ON WEDNESDAY AS WELL...BOTH DAYS COULD BE ACTIVE AT SOME POINT
OR ANOTHER. WEDNESDAY`S POPS ARE A BIT MORE BROAD-BRUSHED THAN I`D
LIKE BUT THERE`S ALWAYS A POSSIBILITY OF A REMNANT MCV TO KICK OFF
CONVECTION.
A BIT ATYPICAL FROM WHAT ONE WOULD EXPECT NORMALLY...BUT THE BL WILL
BEGIN TO DRY OUT FROM THURSDAY ONWARD DESPITE NORMALLY FAVORABLE
EASTERLY FLOW IN THE MID LEVELS. RATHER THAN PULLING MOISTURE
NORTHWARD FROM THE GULF OF CALIFORNIA...IT WOULD APPEAR THE UPPER
RIDGE WILL MIGRATE NORTHWARD AND ADVECT A DRY AIRMASS FROM TEXAS/NEW
MEXICO INTO PLACE BY THE END OF THE WEEK. DIDN`T WANT TO BUY INTO
THIS DRYING TREND AT FACE VALUE SINCE THE ENSEMBLES MAINTAIN SOME
DEGREE OF MOISTURE ACROSS THE AREA /AND SLIGHT VEERING IN THE MID
LEVEL FLOW WOULD KEEP MOISTURE IN PLACE/...THUS I MAINTAINED LOW END
CLIMO-LIKE POPS THROUGH THE END OF THE WEEK. IF DRY AIR ENDS UP
MATERIALIZING AS ADVERTISED IN THE DETERMINISTIC
GUIDANCE...TEMPERATURES WILL ALMOST CERTAINLY ECLIPSE THE 110 DEGREE
MARK ACROSS THE DESERTS AND I STARTED NUDGING HIGHS UP A BIT LATE IN
THE FORECAST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MAJORITY OF THE MONSOON STORM ACTIVITY WILL REMAIN ACROSS EASTERN AZ
TONIGHT...WITH ONLY THE SLIGHTEST OF CHANCES OF ANY ACTIVITY
SURVIVING INTO THE PHX METRO THIS EVENING. MONSOON MOISTURE BOUNDARY
REMAINS ACROSS THE SOUTH-CENTRAL AZ DESERTS...GENERATING THE CU
FIELDS WITH A STRAY...COMPACT...BUT SHORT-LIVED SHOWER OR TWO
SQUEEZING OUT OF THE TALLEST CU...HENCE THE VCSH IN THE KIWA TAF.
SKIES WILL GRADUALLY CLEAR INTO THE EVENING...WITH SOME FEW MID
LEVEL CIGS LINGERING. MOSTLY LIGHT WINDS TO CONTINUE INTO THE
EVENING...TAKING UP SWTSRLY HEADINGS LATER INTO THE AFTN AND
MAINTAINING THOSE LATER INTO THE EVENING THAN TYPICAL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY CLEAR SKIES AND PERIODS OF ELEVATED WEST TO SW WINDS TO
PERSIST FOR THE TAF PERIODS AS DRY AIR CONTINUES TO MOVE INTO THE
AREA FROM THE WEST.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SUBTLE RETURN OF MONSOON MOISTURE COUPLED WITH SOME PASSING UPPER
LEVEL DISTURBANCES FROM THE SOUTHEAST WILL RAISE STORM CHANCES AND
HUMIDITIES FOR TUESDAY. STORM CHANCES WILL EXPAND OUT OF THE EASTERN
AZ HIGHER TERRAIN THROUGH THE LOWER DESERT LOCALES AND TOWARDS THE
CO RIVER VALLEY. CONDITIONS DRY OUT AGAIN BY THE MIDDLE PART OF THE
WEEK AND DAYTIME TEMPERATURES RESPOND IN KIND...WITH THE POTENTIAL
TO GO ABOVE SEASONALLY NORMAL READINGS. WINDS WILL BE LIGHT THROUGH
MUCH OF THE PERIOD FOLLOWING TYPICAL DIURNAL DIRECTIONS EXCEPT FOR
AFTERNOON UPSLOPE BREEZES GUSTING AT TIMES UP TO 20 MPH.
&&
.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
PREVIOUS DISCUSSION...LEINS
AVIATION...NOLTE
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
212 PM MST SAT AUG 8 2015
.SYNOPSIS...
ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE EAST OF PHOENIX
TONIGHT...BUT STORM CHANCES WILL WANE ACROSS THE ENTIRE AREA ON
SUNDAY AS DRIER AIR MOVES INTO THE AREA. A RETURN TO A MORE TYPICAL
MONSOON FLOW IS EXPECTED BY THE MIDDLE OF NEXT WEEK...ALTHOUGH DRIER
AIR IS ONCE AGAIN FORECAST TO OVERSPREAD THE AREA BY THE END OF THE
WEEK.
&&
.DISCUSSION...
LATEST STREAMLINE ANALYSIS SHOWS A WELL-DEFINED SOUTHWESTERLY FLOW IN
THE 850 TO 300 MB LAYER BETWEEN A LOW PRESSURE SYSTEM ACROSS THE
NORTHERN ROCKIES AND AN ANTICYCLONE ACROSS TX. DRIER AIR CONTINUES TO
OVERSPREAD THE AREA AND IS MOST PRONOUNCED FURTHER WEST. AT THE
SURFACE...DEWPOINTS REMAIN ELEVATED IN THE WAKE OF YESTERDAY`S
RAINFALL...AND ARE AS HIGH AS MID TO UPPER 60S ACROSS THE PHOENIX
AREA.
LATEST SATELLITE IMAGERY AND REGIONAL WEBCAMS INDICATE THAT CU IS
STRUGGLING TO DEVELOP VERTICALLY ACROSS THE LOWER DESERTS. THIS IS
LIKELY DUE TO DRY AIR IN THE 850-750 MB LAYER AND A WARM BULGE
AROUND 700 MB EVIDENT IN SEVERAL ACARS PHX SOUNDINGS. LATEST
MESOANALYSIS IS THEREFORE LIKELY OVERESTIMATING INSTABILITY ACROSS
CENTRAL AZ. LATEST RUNS OF THE HRRR CONTINUE TO INITIATE CONVECTION
TOO EARLY AND SUBSEQUENTLY DELAY THE ONSET OF ISOLATED SHOWERS AND
THUNDERSTORMS LATER IN THE AFTERNOON.
A SLIGHT CHANCE OF THUNDERSTORMS WILL PERSIST INTO THIS
EVENING...THOUGH THE BEST CHANCE WILL MAINLY BE CONFINED TO THE
HIGHER TERRAIN EAST OF PHOENIX IN THE VICINITY OF THE DEEPER
MOISTURE. CONSENSUS OF THE LATEST LOCAL/NCEP/U OF AZ WRFS ALSO
SUGGEST NEGLIGIBLE CHANCES OF RAINFALL OR THUNDERSTORM-RELATED
IMPACTS THROUGH THIS EVENING.
&&
.PREVIOUS DISCUSSION...
DRIER AIR WILL ALMOST CERTAINLY OVERSPREAD THE ENTIRE AREA BY LATE
TONIGHT...EFFECTIVELY PUTTING THE BRAKES ON WIDESPREAD MONSOON
CONVECTION FOR THE NEXT SEVERAL DAYS. WHILE THERE WILL BE SMALL
POCKETS OF MOISTURE IN THE MOUNTAINS EAST OF PHOENIX...INSTABILITY
AND A SUFFICIENT TRIGGER APPEAR TO BE LACKING.
A RETURN TO A MORE TYPICAL MONSOON PATTERN IS EXPECTED BY
TUESDAY/WEDNESDAY AND THIS MORNING`S GFS AND ECMWF /AND ENSEMBLES/
SUGGEST AN IMPRESSIVE INCREASE IN MOISTURE. NOT ONLY THAT...BUT THEY
ALSO DEPICT A FAST MOVING 250-300MV PV ANOMALY IN THE AREA TUESDAY
AFTERNOON. INHERITED FORECAST DEPICTED ELEVATED POPS AND I SEE NO
REASON TO REVERSE THIS THINKING. WITH MOISTURE FORECAST TO REMAIN IN
PLACE ON WEDNESDAY AS WELL...BOTH DAYS COULD BE ACTIVE AT SOME POINT
OR ANOTHER. WEDNESDAY`S POPS ARE A BIT MORE BROAD-BRUSHED THAN I`D
LIKE BUT THERE`S ALWAYS A POSSIBILITY OF A REMNANT MCV TO KICK OFF
CONVECTION.
A BIT ATYPICAL FROM WHAT ONE WOULD EXPECT NORMALLY...BUT THE BL WILL
BEGIN TO DRY OUT FROM THURSDAY ONWARD DESPITE NORMALLY FAVORABLE
EASTERLY FLOW IN THE MID LEVELS. RATHER THAN PULLING MOISTURE
NORTHWARD FROM THE GULF OF CALIFORNIA...IT WOULD APPEAR THE UPPER
RIDGE WILL MIGRATE NORTHWARD AND ADVECT A DRY AIRMASS FROM TEXAS/NEW
MEXICO INTO PLACE BY THE END OF THE WEEK. DIDN`T WANT TO BUY INTO
THIS DRYING TREND AT FACE VALUE SINCE THE ENSEMBLES MAINTAIN SOME
DEGREE OF MOISTURE ACROSS THE AREA /AND SLIGHT VEERING IN THE MID
LEVEL FLOW WOULD KEEP MOISTURE IN PLACE/...THUS I MAINTAINED LOW END
CLIMO-LIKE POPS THROUGH THE END OF THE WEEK. IF DRY AIR ENDS UP
MATERIALIZING AS ADVERTISED IN THE DETERMINISTIC
GUIDANCE...TEMPERATURES WILL ALMOST CERTAINLY ECLIPSE THE 110 DEGREE
MARK ACROSS THE DESERTS AND I STARTED NUDGING HIGHS UP A BIT LATE IN
THE FORECAST.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
THE UPPER LOW THAT HELPED TO DRAW MONSOON MOISTURE...AND
CONSIDERABLE SHOWER/THUNDERSTORM ACTIVITY INTO THE GREATER PHOENIX
AREA FRIDAY AFTERNOON/EVENING IS NOW MOVING AWAY FROM THE
REGION...INTO NE NV/SW ID. AS THIS LOW CENTER MOVES AWAY...DRIER
SOUTHWESTERLY FLOW IS EXPECTED TO OVERSPREAD SOUTH-CENTRAL
ARIZONA...WITH A HIGH PROBABILITY THAT THUNDERSTORM ACTIVITY WILL
REMAIN WELL EAST OF THE PHOENIX AREA TERMINALS TODAY. CURRENT BKN-
OVC CIGS ARE EXPECTED TO BECOME FEW-SCT BY THIS AFTERNOON/EVENING.
WINDS TO REVERT BACK TO TYPICAL DIURNAL TRENDS...BUT WITH WESTERLY
WINDS LINGERING LATER INTO THE EVENING HOURS THEN WHAT IS NORMALLY
SEEN THIS TIME OF YEAR.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DRY SOUTHWESTERLY FLOW ALOFT TO KEEP SKIES MAINLY CLEAR THROUGH THE
TAF PERIOD. WINDS TO REMAIN MAINLY FROM A WESTERLY DIRECTION AT KIPL
AND FROM A SOUTH-SOUTHWESTERLY DIRECTION AT KBLH THROUGH THE TAF
PERIOD.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
INCREASING MOISTURE INTO EARLY NEXT WEEK WILL PUSH CHANCES OF
SHOWERS AND THUNDERSTORMS INTO THE SOUTHERN AND WESTERN ARIZONA
DESERTS. MINIMUM RELATIVE HUMIDITIES OF 10 TO 20 PERCENT RANGE WILL
BE COMMON ACROSS THE DESERTS THIS WEEKEND WITH SOME IMPROVEMENT
GOING INTO EARLY NEXT WEEK. DRIEST LOCATION WILL BE SOUTHEAST
CALIFORNIA THIS WEEKEND WITH MINIMUM RH VALUES INTO THE SINGLE
DIGITS. HIGH TEMPERATURES WILL BE AROUND OR SLIGHTLY ABOVE NORMAL
THROUGH THE PERIOD. WINDS WILL BE LIGHT THROUGH MUCH OF THE PERIOD
FOLLOWING TYPICAL DIURNAL DIRECTIONS EXCEPT FOR AFTERNOON UPSLOPE
BREEZES GUSTING AT TIMES UP TO 20 MPH.
&&
.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
PREVIOUS DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
935 PM MST FRI AUG 7 2015
.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR MAINLY
EAST AND SOUTH OF TUCSON THIS WEEKEND. EXPECT GREATER COVERAGE OF
THUNDERSTORMS BY TUESDAY FOLLOWED BY ANOTHER REDUCTION OF
THUNDERSTORM ACTIVITY LATE NEXT WEEK. ABOVE NORMAL DAYTIME
TEMPERATURES WILL PREVAIL INTO THE UPCOMING WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AT
THIS TIME MOSTLY FROM ERN SANTA CRUZ COUNTY EWD ACROSS SRN COCHISE
COUNTY TO THE NEW MEXICO BORDER. OTHER ISOLATED TO SCATTERED SHOWERS
WERE FROM THE TUCSON METRO AREA NWD INTO SOUTH CENTRAL/SERN PINAL
COUNTY. CLOUD TOPS WERE GENERALLY COOLING DURING THE PAST 1-2 HOURS
ACROSS COCHISE/SANTA CRUZ COUNTIES EAST-TO-SOUTH OF TUCSON.
OTHERWISE...MOSTLY CLOUDY SKIES WERE ACROSS THE AREA EXCEPT ACROSS
WRN PIMA COUNTY WHERE CLEAR SKIES PREVAILED. DEWPOINTS AT LOWER
ELEVATIONS VALID 04Z WERE MAINLY IN THE 60S...AND THESE TEMPS WERE
NEARLY 5-10 DEGS F HIGHER VERSUS 24 HOURS AGO. 08/00Z KTWC SOUNDING
TOTAL PRECIP WATER VALUE WAS 1.67 INCH...WITH MLCAPE OF 412 J/KG.
08/00Z NAM/GFS...08/03Z RAP13 AND 08/03Z HRRR DEPICT ONLY A VERY
GRADUAL REDUCTION IN THE COVERAGE OF SHOWERS/TSTMS THE REST OF
TONIGHT INTO EARLY SAT MORNING. THESE MODELS FAVOR ERN PIMA
COUNTY...ERN SANTA CRUZ COUNTY AND WRN COCHISE COUNTY WITH THE
GREATEST POTENTIAL FOR ADDITIONAL SHOWERS/TSTMS.
THUS...FOR THE REST OF TONIGHT INTO EARLY SAT MORNING...HAVE
CONTINUED WITH ISOLATED TO SCATTERED SHOWERS/TSTMS FROM TUCSON EWD/
SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. PRECIP-FREE CONDITIONS
SHOULD CONTINUE ACROSS WRN PIMA COUNTY...SOUTH CENTRAL PINAL COUNTY
AND THE TOHONO O`ODHAM NATION. LOCALLY HEAVY RAINFALL SHOULD OCCUR
WITH THE STRONGER SHOWERS/TSTMS.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 09/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA WILL OCCUR FROM KTUS VICINITY EAST
AND SOUTH INTO SATURDAY MORNING. SCATTERED TO PERHAPS NUMEROUS
-TSRA/-SHRA WILL THEN OCCUR MAINLY EAST OF KTUS SATURDAY AFTERNOON
AND EVENING. EXPECT MVFR CONDITIONS AND BRIEF WIND GUSTS OF 35-45
KTS WITH THE STRONGER TSRA. OTHERWISE...CLEAR SKIES OR MOSTLY CLEAR
SKIES WILL PREVAIL ACROSS WESTERN PIMA COUNTY WEST OF KTUS.
ELSEWHERE...CLOUD DECKS WILL GENERALLY RANGE FROM 7-12K FT AGL.
SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS APART FROM TSRA GUSTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY
EAST AND SOUTH OF TUCSON THROUGH MONDAY. SCATTERED THUNDERSTORMS
WILL THEN OCCUR ACROSS MUCH OF SOUTHEAST ARIZONA TUESDAY INTO
WEDNESDAY. ANOTHER DRYING TREND IS ON TAP DURING THE LATTER PART OF
NEXT WEEK. HOWEVER...THERE WILL BE ENOUGH MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS FAVORING THE WHITE MOUNTAINS AND LOCATIONS
SOUTH OF TUCSON THURSDAY AND FRIDAY.
&&
.PREV DISCUSSION /206 PM MST/...SYNOPTICALLY SPEAKING...AN UPPER
LEVEL LOW PRESSURE CENTER IS TRACKING ACROSS NORTHERN CALIFORNIA AND
THE GREAT BASIN. THE JET DYNAMICS ASSOCIATED WITH THE LOW ARE
SPREADING ACROSS THE STATE HELPING TO ENHANCE THE CHANCE FOR
CONTINUED STORMS INTO THE EVENING. HEAVY RAINFALL...FREQUENT
LIGHTNING...SMALL HAIL...AND STRONG WIND GUSTS WILL ALL BE THREATS
WITH THE STORMS.
THE AREA OF LOW PRESSURE TO OUR NORTH IS EXPECTED TO TRACK EASTWARD
OVER THE NEXT 48 HOURS. IT IS ANTICIPATED THAT THE LOW WILL ACT TO
SHIFT THE DEEP MOISTURE EAST OF THE AREA FOR MUCH OF THE WEEKEND.
ALTHOUGH THE DEEPEST MOISTURE WILL MOVE EASTWARD OVER NEW MEXICO AND
SW TEXAS...ENOUGH WILL LINGER FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND NEAR THE NEW MEXICO BORDER BOTH SATURDAY AND
SUNDAY AFTERNOON. ANOTHER SURGE OF MOISTURE WILL BE POSSIBLE ACROSS
ALL OF SOUTHEAST ARIZONA MONDAY AND TUESDAY AS HIGH PRESSURE
REBOUNDS WESTWARD INTO NM AND CO.
MID RANGE MODELS ARE IN GOOD AGREEMENT THAT THE NEXT MONSOON SURGE
WILL BE FOCUSED ON MONDAY/TUESDAY WITH UPPER LEVEL RIDGING
SUPPRESSING WIDESPREAD CONVECTION BEGINNING EARLY WEDNESDAY AND
LINGERING INTO LATE WEEK. ALONG WITH A REDUCTION IN STORM COVERAGE
DURING THIS PERIOD...TEMPERATURES WILL LIKELY HAVE A CHANCE TO WARM
TO ABOVE NORMAL READINGS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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FRANCIS
PREVIOUS DISCUSSION...CANTIN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
915 PM MST FRI AUG 7 2015
.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS WILL OCCUR MAINLY
EAST AND SOUTH OF TUCSON INTO EARLY NEXT WEEK. EXPECT GREATER
COVERAGE OF THUNDERSTORMS TUESDAY INTO WEDNESDAY FOLLOWED BY REDUCED
ACTIVITY LATE NEXT WEEK. ABOVE NORMAL DAYTIME TEMPERATURES WILL
PREVAIL INTO THE UPCOMING WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS WERE OCCURRING AT
THIS TIME MOSTLY FROM ERN SANTA CRUZ COUNTY EWD ACROSS SRN COCHISE
COUNTY TO THE NEW MEXICO BORDER. OTHER ISOLATED TO SCATTERED SHOWERS
WERE FROM THE TUCSON METRO AREA NWD INTO SOUTH CENTRAL/SERN PINAL
COUNTY. CLOUD TOPS WERE GENERALLY COOLING DURING THE PAST 1-2 HOURS
ACROSS COCHISE/SANTA CRUZ COUNTIES EAST-TO-SOUTH OF TUCSON.
OTHERWISE...MOSTLY CLOUDY SKIES WERE ACROSS THE AREA EXCEPT ACROSS
WRN PIMA COUNTY WHERE CLEAR SKIES PREVAILED. DEWPOINTS AT LOWER
ELEVATIONS VALID 04Z WERE MAINLY IN THE 60S...AND THESE TEMPS WERE
NEARLY 5-10 DEGS F HIGHER VERSUS 24 HOURS AGO. 08/00Z KTWC SOUNDING
TOTAL PRECIP WATER VALUE WAS 1.67 INCH...WITH MLCAPE OF 412 J/KG.
08/00Z NAM/GFS...08/03Z RAP13 AND 08/03Z HRRR DEPICT ONLY A VERY
GRADUAL REDUCTION IN THE COVERAGE OF SHOWERS/TSTMS THE REST OF
TONIGHT INTO EARLY SAT MORNING. THESE MODELS FAVOR ERN PIMA
COUNTY...ERN SANTA CRUZ COUNTY AND WRN COCHISE COUNTY WITH THE
GREATEST POTENTIAL FOR ADDITIONAL SHOWERS/TSTMS.
THUS...FOR THE REST OF TONIGHT INTO EARLY SAT MORNING...HAVE
CONTINUED WITH ISOLATED TO SCATTERED SHOWERS/TSTMS FROM TUCSON EWD/
SWD TO THE NEW MEXICO/INTERNATIONAL BORDERS. PRECIP-FREE CONDITIONS
SHOULD CONTINUE ACROSS WRN PIMA COUNTY...SOUTH CENTRAL PINAL COUNTY
AND THE TOHONO O`ODHAM NATION. LOCALLY HEAVY RAINFALL SHOULD OCCUR
WITH THE STRONGER SHOWERS/TSTMS.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 09/06Z.
ISOLATED TO SCATTERED -TSRA/-SHRA WILL OCCUR FROM KTUS VICINITY EAST
AND SOUTH INTO SATURDAY MORNING. SCATTERED TO PERHAPS NUMEROUS
-TSRA/-SHRA WILL THEN OCCUR MAINLY EAST OF KTUS SATURDAY AFTERNOON
AND EVENING. EXPECT MVFR CONDITIONS AND BRIEF WIND GUSTS OF 35-45
KTS WITH THE STRONGER TSRA. OTHERWISE...CLEAR SKIES OR MOSTLY CLEAR
SKIES WILL PREVAIL ACROSS WESTERN PIMA COUNTY WEST OF KTUS.
ELSEWHERE...CLOUD DECKS WILL GENERALLY RANGE FROM 7-12K FT AGL.
SURFACE WIND WILL MAINLY BE LESS THAN 10 KTS APART FROM TSRA GUSTS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MAINLY
EAST AND SOUTH OF TUCSON THROUGH MONDAY. SCATTERED THUNDERSTORMS
WILL THEN OCCUR ACROSS MUCH OF SOUTHEAST ARIZONA TUESDAY INTO
WEDNESDAY. ANOTHER DRYING TREND IS ON TAP DURING THE LATTER PART OF
NEXT WEEK. HOWEVER...THERE WILL BE ENOUGH MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS FAVORING THE WHITE MOUNTAINS AND LOCATIONS
SOUTH OF TUCSON THURSDAY AND FRIDAY.
&&
.PREV DISCUSSION /206 PM MST/...SYNOPTICALLY SPEAKING...AN UPPER
LEVEL LOW PRESSURE CENTER IS TRACKING ACROSS NORTHERN CALIFORNIA AND
THE GREAT BASIN. THE JET DYNAMICS ASSOCIATED WITH THE LOW ARE
SPREADING ACROSS THE STATE HELPING TO ENHANCE THE CHANCE FOR
CONTINUED STORMS INTO THE EVENING. HEAVY RAINFALL...FREQUENT
LIGHTNING...SMALL HAIL...AND STRONG WIND GUSTS WILL ALL BE THREATS
WITH THE STORMS.
THE AREA OF LOW PRESSURE TO OUR NORTH IS EXPECTED TO TRACK EASTWARD
OVER THE NEXT 48 HOURS. IT IS ANTICIPATED THAT THE LOW WILL ACT TO
SHIFT THE DEEP MOISTURE EAST OF THE AREA FOR MUCH OF THE WEEKEND.
ALTHOUGH THE DEEPEST MOISTURE WILL MOVE EASTWARD OVER NEW MEXICO AND
SW TEXAS...ENOUGH WILL LINGER FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS ALONG AND NEAR THE NEW MEXICO BORDER BOTH SATURDAY AND
SUNDAY AFTERNOON. ANOTHER SURGE OF MOISTURE WILL BE POSSIBLE ACROSS
ALL OF SOUTHEAST ARIZONA BY TUESDAY AS HIGH PRESSURE REBOUNDS
WESTWARD INTO NM AND CO.
MID RANGE MODELS ARE IN GOOD AGREEMENT THAT THE NEXT MONSOON SURGE
WILL BE FOCUSED ON TUESDAY AND WEDNESDAY WITH UPPER LEVEL RIDGING
SUPPRESSING WIDESPREAD CONVECTION BEGINNING EARLY THURSDAY AND
LINGERING INTO LATE WEEK. ALONG WITH A REDUCTION IN STORM COVERAGE
DURING THIS PERIOD...TEMPERATURES WILL LIKELY HAVE A CHANCE TO WARM
TO ABOVE NORMAL READINGS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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FRANCIS
PREVIOUS DISCUSSION...CANTIN
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
551 PM MDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 302 PM MDT SUN AUG 9 2015
SIGNIFICANTLY DRIER AIR WILL REMAIN OVER THE AREA OVERNIGHT. THE
12Z KGJT SOUNDING HAD PRECIPITABLE WATER OF 0.63 IN. DEWPOINTS
WILL CONTINUE TO DROP INTO THE 40S AND EVEN UPPER 30S AT SOME
LOCATIONS. CAPE VALUES ARE PROJECTED IN THE RAP13 AND HRRR TO
REMAIN LOW AS WELL...SO CONVECTION EARLY THIS EVENING WILL BE
WEAK AND ONLY OVER AND DOWNWIND OF RIDGES. ONLY LIGHT
PRECIPITATION IS EXPECTED WITH THESE STORMS ALONG WITH GUSTY
WINDS. THUNDERSTORMS SHOULD DISSIPATE WELL BEFORE MIDNIGHT WITH
NEARLY CLEAR SKIES EXPECTED AGAIN OVERNIGHT.
MOISTURE BEGINS TO INCREASE FROM THE SOUTH AGAIN ON MONDAY...SO EXPECTING
SCATTERED ACTIVITY IN THE SAN JUANS MONDAY EVENING AS THE 12Z NAM
AND GFS INDICATE A H5 VORTICITY MAX REACHING THE FOUR CORNERS
MONDAY EVENING. THE EURO IS A BIT SLOWER WITH THIS ENERGY...BUT IN
ANY CASE IT DOES LOOK LIKE SHOWERS AND ISO TSTORMS WILL CONTINUE
THROUGH THE OVERNIGHT HOURS ON MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 302 PM MDT SUN AUG 9 2015
TUESDAY MORNING WILL BE A MUGGY ONE...WITH CLOUD COVER AND RAIN
SHOWERS ACROSS MUCH OF THE REGION BY MIDDAY. MONSOONAL MOISTURE
WILL BE AT ITS HIGHEST THIS WEEK ON TUESDAY AFTERNOON AS
PRECIPITABLE WATER VALUES ACROSS THE FOUR CORNERS REACH UPWARDS OF
1.2 INCHES AND MORE THAN 0.75 INCHES REACHING THE UT/CO/WY BORDER.
THOUGH DEEP MOISTURE WILL BE IN PLACE...NOT FEELING VERY CONFIDENT
ON THE THREAT OF FLASH FLOODING SINCE WE WILL LIKELY BE DEALING
WITH WIDESPREAD CLOUD COVER AGAIN AND LACK OF LIFTING DUE TO
DAYTIME HEATING. LOCALIZED FLASH FLOODING COULD OCCUR IF THERE IS
SOME CLEARING WHICH PRODUCES ENOUGH LIFT FOR MORE VERTICALLY
SUPPORTED THUNDERSTORMS. WEDNESDAY WILL LIKELY BE MORE OF A THREAT
DAY FOR FLASH FLOODING WITH SKY CONDITIONS LESS CLOUDY BUT WITH
DEEP MOISTURE STILL IN PLACE. FORECAST CONVECTIVE INDICES ON THE
NAM ARE MORE FAVORABLE FOR HEAVY RAIN PRODUCING THUNDERSTORMS ON
WEDNESDAY THAN TUESDAY...SO THESE DAYS WILL NEED TO BE WATCHED FOR
POTENTIAL IMPACTS. THE LACK OF JET SUPPORT WILL KEEP STEERING
WINDS LIGHT THROUGH THE END OF THE WEEK SO ANY SHOWERS AND STORMS
WHICH DEVELOP WILL MOVE SLOWLY. SOME DRYING OCCURS LATER IN THE
WORK WEEK DUE TO HIGH PRESSURE AMPLIFYING OVER THE ROCKIES...BUT
PRECIPITABLE WATER VALUES REMAIN NEAR THREE QUARTERS OF AN INCH
SO DIURNALLY INDUCED SHOWERS AND THUNDERSTORMS WILL DEVELOP
EVERYDAY OVER HIGHER TERRAIN.
NEXT SATURDAY...A TROUGH OVER THE PACIFIC NORTHWEST IS PROGGED TO MOVE
INLAND NORTH OF COLORADO. THE INTERACTION OF THIS TROUGH WITH THE
HIGH PRESSURE IN PLACE OVER THE ROCKIES WILL DRIVE A 50 KT JET
INTO NE UTAH AND NW COLORADO AND POTENTIALLY CREATE MORE
CONVECTIVE ACTIVITY UP NORTH NEXT WEEKEND.
BUMPED HIGH TEMPS UP A COUPLE OF DEGREES IN THE LOWER VALLEYS
TOWARD THE END OF THE WEEK CLOSER TO MOS GUIDANCE FOR A MIDDLE
GROUND SOLUTION. FEEL THAT MOS GUIDANCE IS TOO HOT BUT PREVIOUS
FORECAST WAS TOO LOW CONSIDERING THE EXPECTED AMOUNT OF SUNSHINE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 551 PM MDT SUN AUG 9 2015
LOW CLOUD TOP CONVECTION THROUGH 02Z THIS EVENING WITH LOCAL
SPRINKLES OR -TSRA WITH OUTFLOW 25KT WIND. CLEARING OVERNIGHT BUT
MOISTURE SURGE FROM THE SOUTH ON MONDAY BRING A BETTER CHANCE FOR
-SHRA/-TSRA...ESPECIALLY OVER SW COLORADO AND THE CENTRAL COLORADO
MOUNTAINS. ISOLATED +TSRA WITH CIGS OBSCURING MOUNTAIN TOPS FROM
THE STRONGEST CELLS MONDAY AFTERNOON.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...CC/JAM
LONG TERM...JAM
AVIATION...PF
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1125 AM MDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 956 AM MDT SAT AUG 8 2015
ADJUSTED POPS TO REFLECT LATEST HIGH RES MODEL GUIDANCE RUNS THIS
MORNING. LATEST GUIDANCE IN GOOD AGREEMENT FOR SCATTERED SHOWERS
AND THUNDERSTORMS OVER THE PALMER DIVIDE AND FAR SE CO THIS
AFTERNOON...INCLUDING BACA...BENT...PROWERS...AND KIOWA COUNTIES.
FAR SE CO MAY SEE A FEW STRONG TO SEVERE STORMS LATE THIS
AFTERNOON...AS 30-35 KNOTS OF 0-6 KM BULK SHEAR WILL BE PRESENT
WITH 1000-1500 J/KG OF CAPE AVAILABLE. UPPER LEVEL DISTURBANCES
WITHIN THE MONSOON PLUME WILL HELP TO INITIATE CONVECTION...BUT
THE LIMITING FACTOR COULD BE CAPE...WITH NAM AND HRRR SHOWING DEW
POINTS ONLY IN THE UPPER 40S TO LOW 50S ACROSS THE I-25 CORRIDOR
WITH VALUES SLIGHTLY HIGHER TOWARDS FAR SE CO. LUKINBEAL
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT SAT AUG 8 2015
...ANOTHER ROUND OF THUNDERSTORMS TODAY...A FEW STRONG ACROSS THE
SOUTHEAST PLAINS...
MONSOON PLUME EXTENDS ACROSS CO WITH A COUPLE OF EMBEDDED WAVES
MOVING THROUGH SOUTHWEST FLOW ALOFT. THE FIRST IS MOVING ACROSS THE
SE MTS INTO THE ADJACENT PLAINS EARLY THIS MORNING. THIS WAVE IS
PRETTY WEAK...BUT IS ENHANCING SOME MID/HIGH CLOUD DECK OVER THE
EASTERN PORTIONS OF THE AREA...WITH SOME SPOTTY SHOWERS ACROSS THE
PLAINS AT TIMES. THIS WAVE SHOULD LIFT OFF TO THE NORTHEAST THROUGH
THE MORNING. MEANWHILE...SHOWERS WILL CONTINUE ALONG THE CONTDVD AS
THE NEXT WAVE ACROSS NW AZ LIFTS UP INTO THE 4 CORNERS REGION THIS
MORNING. THIS WAVE WILL MOVE ACROSS THE REMAINDER OF CO DURING THE
AFTERNOON. ACROSS THE PLAINS...SFC LOW IS POSITIONED ACROSS FAR
SOUTHEAST CO...WITH WEST TO NORTHWEST WINDS ALONG THE I-25 CORRIDOR
AND SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. MODELS SUGGEST A
WEAK NORTHERLY SURGE WILL WRAP AROUND THE NORTH SIDE OF THE SFC LOW
INTO THE SE PLAINS...WHICH WILL INCREASE DEW POINTS AGAIN FROM THE
LOWER TO MID 50S...TO MID-UPPER 50S NEAR THE BORDER BY AFTERNOON.
WINDS DON`T LOOK VERY STRONG ACROSS THE PLAINS...BUT THERE SHOULD BE
SOME CONVERGENCE ALONG THIS BOUNDARY WHICH SETS UP ACROSS SOUTHEAST
PLAINS. DEEP LAYER SHEAR LOOKS A LITTLE STRONGER TODAY...BUT CAPES
LOOK LOWER THAN YESTERDAY. EACH SUCCESSIVE RUN OF THE HRRR SEEMS TO
BE TRENDING THE DEW POINTS DOWNWARD ACROSS SE CO WITH HIGHER DEW
POINTS AND CAPES ACROSS SOUTHWEST KANSAS. WILL HAVE TO WATCH TRENDS
IN THE LATEST HIGH RES MODELS AND OBSERVATIONS TODAY TO HONE DOWN
THESE DETAILS. CERTAINLY ENOUGH MOISTURE WILL BE PRESENT FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS. MAIN THREAT WILL BE
LOCALLY HEAVY RAINFALL...WHICH COULD OCCUR JUST ABOUT ANYWHERE.
DEPENDING ON THE POSITION OF THE BOUNDARY AND AMOUNT OF DEW POINT
RETURN...COULD SEE AN ISOLATED STRONG TO SEVERE THUNDERSTORM ACROSS
THE SOUTHEAST COUNTIES...NAMELY KIOWA...BENT...PROWERS...AND BACA
COUNTIES. LARGE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY STORM
THREATS.
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST TONIGHT WITH MORE
DRYING EXPECTED TO SPREAD IN FROM THE WEST AS THE MONSOON PLUME
SHIFTS EASTWARD. THIS SHOULD RESULT IN COOLER LOWS TONIGHT THAN
THIS MORNING ACROSS THE WESTERN MOUNTAIN VALLEYS.
MEANWHILE...MODELS SPREAD HIGHER DEW POINTS BACK INTO THE SE
PLAINS...AND MAY HAVE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
FAR SOUTHEAST PLAINS TOWARDS MORNING. -KT
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM MDT SAT AUG 8 2015
NOT MANY ADJUSTMENTS REQUIRED DURING THE LONGER TERM WITH
RELATIVELY ACTIVE METEOROLOGICAL CONDITIONS ANTICIPATED. PRIMARY
METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES...POPS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL AND STRONGER STORMS AT TIMES.
LATEST PV ANALYSIS...COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS STILL SUGGEST THAT UPPER HIGH CENTERED OVER NORTHEASTERN
TEXAS AT 12Z SUNDAY WILL BEGIN PROGRESSING WEST AND BECOME
CENTERED OVER THE TEXAS PANHANDLE REGION BY TUESDAY. UPPER RIDGE
IS STILL PROJECTED TO BECOME CENTERED OVER THE NORTHERN NEW
MEXICO/COLORADO REGION FROM LATER WEDNESDAY INTO FRIDAY.
DEEPEST ATMOSPHERIC MOISTURE PROFILES DURING THE LONGER TERM ARE
STILL PROJECTED FROM SUNDAY INTO TUESDAY NIGHT. THE MOIST ATMOSPHERIC
PROFILE WILL INTERACT WITH FAVORABLE LOW-LEVEL WIND FLOW...THE
DAILY OROGRAPHIC CYCLE AND UPPER DISTURBANCES AT TIMES TO PRODUCE
GENERALLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO AT LEAST
TUESDAY NIGHT WITH SLIGHTLY DECREASED POPS THEN EXPECTED BY LATER
IN THE WEEK.
PER PREVIOUS DISCUSSIONS...ESPECIALLY DURING THE SUNDAY INTO
TUESDAY NIGHT TIME-FRAME...THE PROJECTED HIGHER PRECIPITABLE
WATER VALUES ARE EXPECTED TO GENERATE LOCALLY HEAVY RAINFALL
CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING AT
TIMES...ESPECIALLY IF THE HEAVY RAINFALL IMPACTS RECENT BURN
SCARS. ALSO...STRONGER STORMS AT TIMES ARE ALSO ANTICIPATED
DUE TO SOMEWHAT ELEVATED CAPE...LI AND BULK SHEAR VALUES.
ALSO...GENERALLY ABOVE CLIMATOLOGICAL EARLY TO MID AUGUST
TEMPERATURES ARE STILL PROJECTED DURING THE MAJORITY OF THE LONGER
TERM WITH MONDAY AND TUESDAY HAVING THE HIGHEST POTENTIAL OF
EXPERIENCING BELOW SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1122 AM MDT SAT AUG 8 2015
VFR CONDITIONS EXPECTED AT THE TAF SITES THROUGH THE AFTERNOON AND
EARLY EVENING...WITH BRIEF MVFR CIGS/VIS POSSIBLE UNDER STRONGER
THUNDERSTORMS. SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS...PALMER DIVIDE...AND RATON MESA THIS AFTERNOON BEFORE
SPREADING ACROSS THE EASTERN PLAINS. ALL THREE TAF SITES COULD SEE
VCTS AFTER 21-22Z WITH GUSTY OUTFLOW WINDS BEING THE PRIMARY
CONCERN. OVERNIGHT LASTEST MODEL GUIDANCE IS SUGGESTING A STRATUS
DECK DEVELOPING ACROSS THE EASTERN PLAINS AS OUTFLOW BOUNDARIES FROM
WESTERN KS AND SE UPSLOPE FLOW PUSH MOIST LOW LEVEL MOISTURE INTO
THE I-25 CORRIDOR. STARTING AROUND 08Z...KCOS AND KPUB WILL LIKELY
BE IMPACTED BY THE STRATUS DECK WITH MVFR TO BRIEF IFR CONDITIONS
POSSIBLE OVERNIGHT INTO EARLY TOMORROW MORNING DUE TO CIGS...WITH
STRATUS EXPECTED TO CLEAR OUT BY 15Z AS WINDS SHIFT TO A N/NE
COMPONENT AT KCOS AND KPUB. LUKINBEAL
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/HODANISH
AVIATION...AL/HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1013 AM MDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 956 AM MDT SAT AUG 8 2015
ADJUSTED POPS TO REFLECT LATEST HIGH RES MODEL GUIDANCE RUNS THIS
MORNING. LATEST GUIDANCE IN GOOD AGREEMENT FOR SCATTERED SHOWERS
AND THUNDERSTORMS OVER THE PALMER DIVIDE AND FAR SE CO THIS
AFTERNOON...INCLUDING BACA...BENT...PROWERS...AND KIOWA COUNTIES.
FAR SE CO MAY SEE A FEW STRONG TO SEVERE STORMS LATE THIS
AFTERNOON...AS 30-35 KNOTS OF 0-6 KM BULK SHEAR WILL BE PRESENT
WITH 1000-1500 J/KG OF CAPE AVAILABLE. UPPER LEVEL DISTURBANCES
WITHIN THE MONSOON PLUME WILL HELP TO INITIATE CONVECTION...BUT
THE LIMITING FACTOR COULD BE CAPE...WITH NAM AND HRRR SHOWING DEW
POINTS ONLY IN THE UPPER 40S TO LOW 50S ACROSS THE I-25 CORRIDOR
WITH VALUES SLIGHTLY HIGHER TOWARDS FAR SE CO. LUKINBEAL
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT SAT AUG 8 2015
...ANOTHER ROUND OF THUNDERSTORMS TODAY...A FEW STRONG ACROSS THE
SOUTHEAST PLAINS...
MONSOON PLUME EXTENDS ACROSS CO WITH A COUPLE OF EMBEDDED WAVES
MOVING THROUGH SOUTHWEST FLOW ALOFT. THE FIRST IS MOVING ACROSS THE
SE MTS INTO THE ADJACENT PLAINS EARLY THIS MORNING. THIS WAVE IS
PRETTY WEAK...BUT IS ENHANCING SOME MID/HIGH CLOUD DECK OVER THE
EASTERN PORTIONS OF THE AREA...WITH SOME SPOTTY SHOWERS ACROSS THE
PLAINS AT TIMES. THIS WAVE SHOULD LIFT OFF TO THE NORTHEAST THROUGH
THE MORNING. MEANWHILE...SHOWERS WILL CONTINUE ALONG THE CONTDVD AS
THE NEXT WAVE ACROSS NW AZ LIFTS UP INTO THE 4 CORNERS REGION THIS
MORNING. THIS WAVE WILL MOVE ACROSS THE REMAINDER OF CO DURING THE
AFTERNOON. ACROSS THE PLAINS...SFC LOW IS POSITIONED ACROSS FAR
SOUTHEAST CO...WITH WEST TO NORTHWEST WINDS ALONG THE I-25 CORRIDOR
AND SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. MODELS SUGGEST A
WEAK NORTHERLY SURGE WILL WRAP AROUND THE NORTH SIDE OF THE SFC LOW
INTO THE SE PLAINS...WHICH WILL INCREASE DEW POINTS AGAIN FROM THE
LOWER TO MID 50S...TO MID-UPPER 50S NEAR THE BORDER BY AFTERNOON.
WINDS DON`T LOOK VERY STRONG ACROSS THE PLAINS...BUT THERE SHOULD BE
SOME CONVERGENCE ALONG THIS BOUNDARY WHICH SETS UP ACROSS SOUTHEAST
PLAINS. DEEP LAYER SHEAR LOOKS A LITTLE STRONGER TODAY...BUT CAPES
LOOK LOWER THAN YESTERDAY. EACH SUCCESSIVE RUN OF THE HRRR SEEMS TO
BE TRENDING THE DEW POINTS DOWNWARD ACROSS SE CO WITH HIGHER DEW
POINTS AND CAPES ACROSS SOUTHWEST KANSAS. WILL HAVE TO WATCH TRENDS
IN THE LATEST HIGH RES MODELS AND OBSERVATIONS TODAY TO HONE DOWN
THESE DETAILS. CERTAINLY ENOUGH MOISTURE WILL BE PRESENT FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS. MAIN THREAT WILL BE
LOCALLY HEAVY RAINFALL...WHICH COULD OCCUR JUST ABOUT ANYWHERE.
DEPENDING ON THE POSITION OF THE BOUNDARY AND AMOUNT OF DEW POINT
RETURN...COULD SEE AN ISOLATED STRONG TO SEVERE THUNDERSTORM ACROSS
THE SOUTHEAST COUNTIES...NAMELY KIOWA...BENT...PROWERS...AND BACA
COUNTIES. LARGE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY STORM
THREATS.
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST TONIGHT WITH MORE
DRYING EXPECTED TO SPREAD IN FROM THE WEST AS THE MONSOON PLUME
SHIFTS EASTWARD. THIS SHOULD RESULT IN COOLER LOWS TONIGHT THAN
THIS MORNING ACROSS THE WESTERN MOUNTAIN VALLEYS.
MEANWHILE...MODELS SPREAD HIGHER DEW POINTS BACK INTO THE SE
PLAINS...AND MAY HAVE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
FAR SOUTHEAST PLAINS TOWARDS MORNING. -KT
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM MDT SAT AUG 8 2015
NOT MANY ADJUSTMENTS REQUIRED DURING THE LONGER TERM WITH
RELATIVELY ACTIVE METEOROLOGICAL CONDITIONS ANTICIPATED. PRIMARY
METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES...POPS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL AND STRONGER STORMS AT TIMES.
LATEST PV ANALYSIS...COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS STILL SUGGEST THAT UPPER HIGH CENTERED OVER NORTHEASTERN
TEXAS AT 12Z SUNDAY WILL BEGIN PROGRESSING WEST AND BECOME
CENTERED OVER THE TEXAS PANHANDLE REGION BY TUESDAY. UPPER RIDGE
IS STILL PROJECTED TO BECOME CENTERED OVER THE NORTHERN NEW
MEXICO/COLORADO REGION FROM LATER WEDNESDAY INTO FRIDAY.
DEEPEST ATMOSPHERIC MOISTURE PROFILES DURING THE LONGER TERM ARE
STILL PROJECTED FROM SUNDAY INTO TUESDAY NIGHT. THE MOIST ATMOSPHERIC
PROFILE WILL INTERACT WITH FAVORABLE LOW-LEVEL WIND FLOW...THE
DAILY OROGRAPHIC CYCLE AND UPPER DISTURBANCES AT TIMES TO PRODUCE
GENERALLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO AT LEAST
TUESDAY NIGHT WITH SLIGHTLY DECREASED POPS THEN EXPECTED BY LATER
IN THE WEEK.
PER PREVIOUS DISCUSSIONS...ESPECIALLY DURING THE SUNDAY INTO
TUESDAY NIGHT TIME-FRAME...THE PROJECTED HIGHER PRECIPITABLE
WATER VALUES ARE EXPECTED TO GENERATE LOCALLY HEAVY RAINFALL
CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING AT
TIMES...ESPECIALLY IF THE HEAVY RAINFALL IMPACTS RECENT BURN
SCARS. ALSO...STRONGER STORMS AT TIMES ARE ALSO ANTICIPATED
DUE TO SOMEWHAT ELEVATED CAPE...LI AND BULK SHEAR VALUES.
ALSO...GENERALLY ABOVE CLIMATOLOGICAL EARLY TO MID AUGUST
TEMPERATURES ARE STILL PROJECTED DURING THE MAJORITY OF THE LONGER
TERM WITH MONDAY AND TUESDAY HAVING THE HIGHEST POTENTIAL OF
EXPERIENCING BELOW SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 500 AM MDT SAT AUG 8 2015
VFR CONDITIONS EXPECT THIS MORNING AT THE TAF SITES...THOUGH
WILL HAVE TO WATCH KALS CLOSELY AS T/TD SPREADS ARE CLOSE. FOR NOW
THINK EXTENSIVE MID AND HIGH CLOUD COVER SHOULD PREVENT ANY PATCHY
GROUND FOG DEVELOPMENT. THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS...AND PALMER AND RATON MESA REGIONS BY AFTERNOON. AS
THESE THUNDERSTORMS SPREAD EASTWARD ACROSS THE LOWER
ELEVATIONS...ALL THREE TAF SITES COULD SEE VCTS AFTER 20-21Z.
GUSTY ERRATIC WINDS...AND VFR TO BRIEF MVFR CIGS/VIS WILL BE
POSSIBLE WITH THE STRONGER STORMS. THUNDERSTORMS SHOULD MOVE
EASTWARD AND DIMINISH THIS EVENING...WITH CONDITIONS REMAINING
VFR. COULD SEE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
SOUTHEAST PLAINS SATURDAY NIGHT...BUT FOR NOW MOST LIKELY AREA
APPEARS TO BE EAST OF THE I-25 CORRIDOR AND THE KCOS AND KPUB
TERMINALS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/HODANISH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
502 AM MDT SAT AUG 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM MDT SAT AUG 8 2015
...ANOTHER ROUND OF THUNDERSTORMS TODAY...A FEW STRONG ACROSS THE
SOUTHEAST PLAINS...
MONSOON PLUME EXTENDS ACROSS CO WITH A COUPLE OF EMBEDDED WAVES
MOVING THROUGH SOUTHWEST FLOW ALOFT. THE FIRST IS MOVING ACROSS THE
SE MTS INTO THE ADJACENT PLAINS EARLY THIS MORNING. THIS WAVE IS
PRETTY WEAK...BUT IS ENHANCING SOME MID/HIGH CLOUD DECK OVER THE
EASTERN PORTIONS OF THE AREA...WITH SOME SPOTTY SHOWERS ACROSS THE
PLAINS AT TIMES. THIS WAVE SHOULD LIFT OFF TO THE NORTHEAST THROUGH
THE MORNING. MEANWHILE...SHOWERS WILL CONTINUE ALONG THE CONTDVD AS
THE NEXT WAVE ACROSS NW AZ LIFTS UP INTO THE 4 CORNERS REGION THIS
MORNING. THIS WAVE WILL MOVE ACROSS THE REMAINDER OF CO DURING THE
AFTERNOON. ACROSS THE PLAINS...SFC LOW IS POSITIONED ACROSS FAR
SOUTHEAST CO...WITH WEST TO NORTHWEST WINDS ALONG THE I-25 CORRIDOR
AND SOUTHERN PORTIONS OF THE SOUTHEAST PLAINS. MODELS SUGGEST A
WEAK NORTHERLY SURGE WILL WRAP AROUND THE NORTH SIDE OF THE SFC LOW
INTO THE SE PLAINS...WHICH WILL INCREASE DEW POINTS AGAIN FROM THE
LOWER TO MID 50S...TO MID-UPPER 50S NEAR THE BORDER BY AFTERNOON.
WINDS DON`T LOOK VERY STRONG ACROSS THE PLAINS...BUT THERE SHOULD BE
SOME CONVERGENCE ALONG THIS BOUNDARY WHICH SETS UP ACROSS SOUTHEAST
PLAINS. DEEP LAYER SHEAR LOOKS A LITTLE STRONGER TODAY...BUT CAPES
LOOK LOWER THAN YESTERDAY. EACH SUCCESSIVE RUN OF THE HRRR SEEMS TO
BE TRENDING THE DEW POINTS DOWNWARD ACROSS SE CO WITH HIGHER DEW
POINTS AND CAPES ACROSS SOUTHWEST KANSAS. WILL HAVE TO WATCH TRENDS
IN THE LATEST HIGH RES MODELS AND OBSERVATIONS TODAY TO HONE DOWN
THESE DETAILS. CERTAINLY ENOUGH MOISTURE WILL BE PRESENT FOR AT
LEAST ISOLATED TO SCATTERED THUNDERSTORMS. MAIN THREAT WILL BE
LOCALLY HEAVY RAINFALL...WHICH COULD OCCUR JUST ABOUT ANYWHERE.
DEPENDING ON THE POSITION OF THE BOUNDARY AND AMOUNT OF DEW POINT
RETURN...COULD SEE AN ISOLATED STRONG TO SEVERE THUNDERSTORM ACROSS
THE SOUTHEAST COUNTIES...NAMELY KIOWA...BENT...PROWERS...AND BACA
COUNTIES. LARGE HAIL AND DAMAGING WINDS WOULD BE THE PRIMARY STORM
THREATS.
THUNDERSTORMS SHOULD DIMINISH FROM WEST TO EAST TONIGHT WITH MORE
DRYING EXPECTED TO SPREAD IN FROM THE WEST AS THE MONSOON PLUME
SHIFTS EASTWARD. THIS SHOULD RESULT IN COOLER LOWS TONIGHT THAN
THIS MORNING ACROSS THE WESTERN MOUNTAIN VALLEYS.
MEANWHILE...MODELS SPREAD HIGHER DEW POINTS BACK INTO THE SE
PLAINS...AND MAY HAVE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
FAR SOUTHEAST PLAINS TOWARDS MORNING. -KT
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM MDT SAT AUG 8 2015
NOT MANY ADJUSTMENTS REQUIRED DURING THE LONGER TERM WITH
RELATIVELY ACTIVE METEOROLOGICAL CONDITIONS ANTICIPATED. PRIMARY
METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES...POPS AND THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL AND STRONGER STORMS AT TIMES.
LATEST PV ANALYSIS...COMPUTER SIMULATIONS AND FORECAST MODEL
SOUNDINGS STILL SUGGEST THAT UPPER HIGH CENTERED OVER NORTHEASTERN
TEXAS AT 12Z SUNDAY WILL BEGIN PROGRESSING WEST AND BECOME
CENTERED OVER THE TEXAS PANHANDLE REGION BY TUESDAY. UPPER RIDGE
IS STILL PROJECTED TO BECOME CENTERED OVER THE NORTHERN NEW
MEXICO/COLORADO REGION FROM LATER WEDNESDAY INTO FRIDAY.
DEEPEST ATMOSPHERIC MOISTURE PROFILES DURING THE LONGER TERM ARE
STILL PROJECTED FROM SUNDAY INTO TUESDAY NIGHT. THE MOIST ATMOSPHERIC
PROFILE WILL INTERACT WITH FAVORABLE LOW-LEVEL WIND FLOW...THE
DAILY OROGRAPHIC CYCLE AND UPPER DISTURBANCES AT TIMES TO PRODUCE
GENERALLY SCATTERED SHOWER AND THUNDERSTORM ACTIVITY INTO AT LEAST
TUESDAY NIGHT WITH SLIGHTLY DECREASED POPS THEN EXPECTED BY LATER
IN THE WEEK.
PER PREVIOUS DISCUSSIONS...ESPECIALLY DURING THE SUNDAY INTO
TUESDAY NIGHT TIME-FRAME...THE PROJECTED HIGHER PRECIPITABLE
WATER VALUES ARE EXPECTED TO GENERATE LOCALLY HEAVY RAINFALL
CAPABLE OF PRODUCING LOCALIZED FLASH FLOODING AT
TIMES...ESPECIALLY IF THE HEAVY RAINFALL IMPACTS RECENT BURN
SCARS. ALSO...STRONGER STORMS AT TIMES ARE ALSO ANTICIPATED
DUE TO SOMEWHAT ELEVATED CAPE...LI AND BULK SHEAR VALUES.
ALSO...GENERALLY ABOVE CLIMATOLOGICAL EARLY TO MID AUGUST
TEMPERATURES ARE STILL PROJECTED DURING THE MAJORITY OF THE LONGER
TERM WITH MONDAY AND TUESDAY HAVING THE HIGHEST POTENTIAL OF
EXPERIENCING BELOW SEASONAL TEMPERATURES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 500 AM MDT SAT AUG 8 2015
VFR CONDITIONS EXPECT THIS MORNING AT THE TAF SITES...THOUGH
WILL HAVE TO WATCH KALS CLOSELY AS T/TD SPREADS ARE CLOSE. FOR NOW
THINK EXTENSIVE MID AND HIGH CLOUD COVER SHOULD PREVENT ANY PATCHY
GROUND FOG DEVELOPMENT. THUNDERSTORMS WILL DEVELOP OVER THE
MOUNTAINS...AND PALMER AND RATON MESA REGIONS BY AFTERNOON. AS
THESE THUNDERSTORMS SPREAD EASTWARD ACROSS THE LOWER
ELEVATIONS...ALL THREE TAF SITES COULD SEE VCTS AFTER 20-21Z.
GUSTY ERRATIC WINDS...AND VFR TO BRIEF MVFR CIGS/VIS WILL BE
POSSIBLE WITH THE STRONGER STORMS. THUNDERSTORMS SHOULD MOVE
EASTWARD AND DIMINISH THIS EVENING...WITH CONDITIONS REMAINING
VFR. COULD SEE SOME STRATUS DEVELOP ACROSS PORTIONS OF THE
SOUTHEAST PLAINS SATURDAY NIGHT...BUT FOR NOW MOST LIKELY AREA
APPEARS TO BE EAST OF THE I-25 CORRIDOR AND THE KCOS AND KPUB
TERMINALS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
700 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH SUN AS LOW
PRESSURE REMAINS WELL OFFSHORE...THOUGH A SPOT SHOWER IS POSSIBLE
ACROSS THE INTERIOR SUN AFTERNOON. LOW PRESSURE WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MON NIGHT INTO WED
MORNING. A TREND TOWARD DRIER WEATHER IS LIKELY THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
7 PM UPDATE...HIGH CIRRUS CLOUDS REMAIN IN PLACE ACROSS SOUTHERN
NEW ENGLAND THIS EVENING. MADE SOME ADJUSTMENTS TO THE SKY COVER
TO ACCOUNT FOR THE LATEST SATELLITE TRENDS. OTHERWISE...THE
FORECAST IS ON TRACK.
315 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU WHICH IS EVIDENT ON SATELLITE NEAR
BERKSHIRES.
MEANWHILE COASTAL LOW IS THROWING BACK SOME PATCHY MID AND HIGH
CLOUDS ALONG S COAST...CAPE COD AND ISLANDS. EXPECT THESE CLOUDS
TO THICKEN UP TONIGHT BUT NO RAIN EXPECTED AS BEST LIFT STAYS
OFFSHORE WITH PROGRESSIVE UPPER FLOW. SOME OF HIGH-RES MODELS
/HRRR...RAP AND ARW-WRF/ WANT TO BRING RAINFALL TO SE NEW ENGLAND
LATER TONIGHT BUT THAT LOOKS TO BE OVERDONE.
ANOTHER PLEASANTLY COOL NIGHT AHEAD WITH GOOD RADIATIONAL COOLING
CONDITIONS AWAY FROM INFLUENCE OF MID/HIGH CLOUDS NEAR S COAST.
LEANED TOWARD COOLER GFS LAMP GUIDANCE WHICH BRINGS LOWS INTO
UPPER 40S ACROSS NW MA AND MAINLY 50S ELSEWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
EXPECTING A GOOD AMOUNT OF CLOUDINESS NEAR CAPE COD AND ISLANDS
SUN DUE TO INCREASING NE FLOW ON PERIPHERY OF COASTAL LOW. MODEL
CROSS SECTIONS SHOW GOOD AMOUNT OF LOW LEVEL MOISTURE BELOW 950 MB
WHICH SHOULD BECOME TRAPPED. NO REAL MECHANISM FOR RAINFALL SO DRY
WEATHER ANTICIPATED AS DEEPER MOISTURE AND LIFT REMAIN WELL
OFFSHORE. SOME QUESTION AS TO WHETHER OR NOT LOW CLOUDS WILL BREAK
DURING AFTERNOON...BUT FOR NOW LEANED TOWARD THEM HANGING ON.
ACROSS INTERIOR...MODELS CONTINUE TO HINT AT POSSIBILITY OF FEW
SHOWERS BY AFTERNOON DUE TO SUBTLE LIFT FROM UPPER TROUGH. LOW
LEVEL CONVERGENCE IS MINIMAL DUE TO WEAK WIND FIELDS...SO ANY
ACTIVITY WOULD BE TIED TO TERRAIN. STABILITY PARAMETERS MARGINAL
SO EXPECT AN ISOLATED SHOWER OR PERHAPS A THUNDERSTORM ACROSS NW
AND POSSIBLY N CENTRAL MA.
HIGHS SHOULD BE A LITTLE COOLER THAN TODAY...ESPECIALLY NEAR COAST
DUE TO NE FLOW AND CLOUDINESS...RANGING FROM AROUND 70 ON OUTER
CAPE TO AROUND 80 FARTHER INLAND.
SUBSIDENCE AND SOME DRYING SUN NIGHT SHOULD LEAD TO AT LEAST
PARTIAL CLEARING...BUT CONTINUED ONSHORE FLOW MAY KEEP CLOUDS
LOCKED IN CLOSER TO COAST. LOWS SHOULD DROP BACK INTO 50S AND
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* UNSETTLED WEATHER LIKELY LATE MON NIGHT THROUGH WED MORNING
* TEMPS SLIGHTLY BELOW NORMAL FOR MUCH OF THE WEEK
* POSSIBLE RETURN TO AUGUST HEAT FOR SATURDAY
OVERALL...MODELS ARE IN DECENT AGREEMENT THROUGH MUCH OF THE LONG
TERM. THERE ARE A COUPLE OF DISCREPANCIES THAT CONTINUE THROUGH THE
PERIOD. AS FAR AS SENSIBLE WEATHER GOES...THE MODELS ARE IN
AGREEMENT. LOOKING AT AN UPPER LEVEL TROUGH IN THE GREAT LAKES
MONDAY SLOWLY MOVING EASTWARD OVER THE NORTHEAST AND NEW ENGLAND BY
WEDNESDAY AND POTENTIALLY STALLING THERE THROUGH THE END OF THE
FORECAST PERIOD. THE ECMWF KEEPS THE PATTERN MORE AMPLIFIED...WHILE
THE GFS HAS A FLATTER FLOW AT THE MID-LEVELS WITH THE TROUGH
RETREATING INTO SOUTHEASTERN CANADA.
THIS TROUGH RESULTS IN LOW PRESSURE DEVELOPING IN THE GREAT LAKES
AND MOVING INTO QUEBEC TUESDAY. THE ECMWF PRODUCES A TRIPLE POINT
LOW OVER NEW JERSEY OFF THE MAIN LOW IN QUEBEC AND TRANSLATES THE
TRIPLE POINT LOW ALONG THE SOUTHERN NEW ENGLAND COAST. THE GFS
DEPICTS NO SUCH REDEVELOPMENT BUT KEEPS A STRONG SOUTHERLY FLOW
AHEAD OF THE COLD FRONT EXTENDING FROM THE QUEBEC LOW. THESE
DIFFERENCES COULD AFFECT THE OVERALL NATURE OF THE RAIN /WHETHER ITS
MORE STRATIFORM OR SHOWERY/ BUT REGARDLESS OF THE NATURE OR THE TYPE
OF SYSTEM...TUESDAY IS LIKELY TO BE WET. MODELS HINT THAT THE RAIN
COULD MOVE INTO OUR WESTERN ZONES LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT THE BULK OF THE RAIN APPEARS TO HOLD OFF TIL
AFTER 12Z TUESDAY. RAIN CONTINUES THROUGH TUESDAY INTO THE FIRST
PART OF THE DAY ON WEDNESDAY BUT THEN WILL TAPER OFF AS EITHER THE
FRONT MOVES THROUGH OR THE LOW PRESSURE EJECTS TOWARDS THE MARITIMES.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY WITH A POSSIBILITY OF A
FEW DIURNAL SHOWERS HERE AND THERE EACH DAY. TEMPERATURES ARE
EXPECTED TO BE BELOW TO NEAR NORMAL UNTIL THE WEEKEND WHEN DEPENDING
ON THE MODEL COULD SEE A RETURN TO AUGUST HEAT AND HUMIDITY.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
00Z UPDATE...HIGH CONFIDENCE.
VFR TONIGHT WITH LIGHT N/NE WINDS. SHOULD SEE MVFR CIGS SPREAD
FROM OCEAN ONTO CAPE COD AND ISLANDS EARLY SUN MORNING. SOME
QUESTION AS TO WHETHER OR NOT CIGS SCT OUT OR LIFT TO VFR SUN
AFTERNOON. FOR NOW WE THINK CIGS WILL REMAIN MVFR THROUGH MUCH OF
DAY AND INTO SUN NIGHT. OTHERWISE VFR ELSEWHERE WITH BRIEF SHOWER
POSSIBLE ACROSS NW MA SUN AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR/IFR
CIGS/VSBYS ENTERING WESTERN ZONES LATE MONDAY NIGHT WITH -RA.
TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY IN
WIDESPREAD RAIN/FOG.
WEDNESDAY...MODERATE CONFIDENCE. LINGERING MVFR/IFR CONDITIONS IN
DEPARTING RAIN. IMPROVING CONDITIONS THROUGH THE DAY.
THURSDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF
BRIEF MVFR CONDITIONS IN DIURNAL -SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH SUN NIGHT.
DROPPED SCA ON OUTER S COASTAL WATERS WHERE SEAS HAVE SUBSIDED.
LIGHT N/NE WINDS GIVE WAY TO INCREASING NE WINDS SUN AND
ESPECIALLY SUN NIGHT...AS LOW PRESSURE PASSES WELL SE OF NEW
ENGLAND. SEAS SHOULD BEGIN TO BUILD LATER IN DAY AND COULD REACH 5
FT BY SUN NIGHT E AND S OF NANTUCKET...WHICH MAY REQUIRE SCA IN
LATER FORECASTS. DRY WEATHER EXPECTED THROUGH PERIOD.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE
BUILDS OVER THE WATERS.
TUESDAY...MODERATE CONFIDENCE. WINDS AND SEAS INCREASE AS EITHER A
COLD FRONT OR A LOW PRESSURE SYSTEM MOVE OVER THE WATERS. SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SEAS IF NOT WINDS AS
WELL. VISIBILITIES MAY BE LIMITED AT TIMES IN RAIN.
WEDNESDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS LOW
PRESSURE PULLS AWAY FROM SOUTHERN NEW ENGLAND.
THURSDAY...MODERATE CONFIDENCE. QUIET BOATING WEATHER EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RLG/JWD
NEAR TERM...RLG/JWD
SHORT TERM...JWD
LONG TERM...RLG
AVIATION...RLG/JWD
MARINE...RLG/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
315 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH SUN AS LOW
PRESSURE REMAINS WELL OFFSHORE...THOUGH A SPOT SHOWER IS POSSIBLE
ACROSS THE INTERIOR SUN AFTERNOON. LOW PRESSURE WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MON NIGHT INTO WED
MORNING. A TREND TOWARD DRIER WEATHER IS LIKELY THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
315 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU WHICH IS EVIDENT ON SATELLITE NEAR
BERKSHIRES.
MEANWHILE COASTAL LOW IS THROWING BACK SOME PATCHY MID AND HIGH
CLOUDS ALONG S COAST...CAPE COD AND ISLANDS. EXPECT THESE CLOUDS
TO THICKEN UP TONIGHT BUT NO RAIN EXPECTED AS BEST LIFT STAYS
OFFSHORE WITH PROGRESSIVE UPPER FLOW. SOME OF HIGH-RES MODELS
/HRRR...RAP AND ARW-WRF/ WANT TO BRING RAINFALL TO SE NEW ENGLAND
LATER TONIGHT BUT THAT LOOKS TO BE OVERDONE.
ANOTHER PLEASANTLY COOL NIGHT AHEAD WITH GOOD RADIATIONAL COOLING
CONDITIONS AWAY FROM INFLUENCE OF MID/HIGH CLOUDS NEAR S COAST.
LEANED TOWARD COOLER GFS LAMP GUIDANCE WHICH BRINGS LOWS INTO
UPPER 40S ACROSS NW MA AND MAINLY 50S ELSEWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
EXPECTING A GOOD AMOUNT OF CLOUDINESS NEAR CAPE COD AND ISLANDS
SUN DUE TO INCREASING NE FLOW ON PERIPHERY OF COASTAL LOW. MODEL
CROSS SECTIONS SHOW GOOD AMOUNT OF LOW LEVEL MOISTURE BELOW 950 MB
WHICH SHOULD BECOME TRAPPED. NO REAL MECHANISM FOR RAINFALL SO DRY
WEATHER ANTICIPATED AS DEEPER MOISTURE AND LIFT REMAIN WELL
OFFSHORE. SOME QUESTION AS TO WHETHER OR NOT LOW CLOUDS WILL BREAK
DURING AFTERNOON...BUT FOR NOW LEANED TOWARD THEM HANGING ON.
ACROSS INTERIOR...MODELS CONTINUE TO HINT AT POSSIBILITY OF FEW
SHOWERS BY AFTERNOON DUE TO SUBTLE LIFT FROM UPPER TROUGH. LOW
LEVEL CONVERGENCE IS MINIMAL DUE TO WEAK WIND FIELDS...SO ANY
ACTIVITY WOULD BE TIED TO TERRAIN. STABILITY PARAMETERS MARGINAL
SO EXPECT AN ISOLATED SHOWER OR PERHAPS A THUNDERSTORM ACROSS NW
AND POSSIBLY N CENTRAL MA.
HIGHS SHOULD BE A LITTLE COOLER THAN TODAY...ESPECIALLY NEAR COAST
DUE TO NE FLOW AND CLOUDINESS...RANGING FROM AROUND 70 ON OUTER
CAPE TO AROUND 80 FARTHER INLAND.
SUBSIDENCE AND SOME DRYING SUN NIGHT SHOULD LEAD TO AT LEAST
PARTIAL CLEARING...BUT CONTINUED ONSHORE FLOW MAY KEEP CLOUDS
LOCKED IN CLOSER TO COAST. LOWS SHOULD DROP BACK INTO 50S AND
LOWER 60S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGHLIGHTS...
* UNSETTLED WEATHER LIKELY LATE MON NIGHT THROUGH WED MORNING
* TEMPS SLIGHTLY BELOW NORMAL FOR MUCH OF THE WEEK
* POSSIBLE RETURN TO AUGUST HEAT FOR SATURDAY
OVERALL...MODELS ARE IN DECENT AGREEMENT THROUGH MUCH OF THE LONG
TERM. THERE ARE A COUPLE OF DISCREPANCIES THAT CONTINUE THROUGH THE
PERIOD. AS FAR AS SENSIBLE WEATHER GOES...THE MODELS ARE IN
AGREEMENT. LOOKING AT AN UPPER LEVEL TROUGH IN THE GREAT LAKES
MONDAY SLOWLY MOVING EASTWARD OVER THE NORTHEAST AND NEW ENGLAND BY
WEDNESDAY AND POTENTIALLY STALLING THERE THROUGH THE END OF THE
FORECAST PERIOD. THE ECMWF KEEPS THE PATTERN MORE AMPLIFIED...WHILE
THE GFS HAS A FLATTER FLOW AT THE MID-LEVELS WITH THE TROUGH
RETREATING INTO SOUTHEASTERN CANADA.
THIS TROUGH RESULTS IN LOW PRESSURE DEVELOPING IN THE GREAT LAKES
AND MOVING INTO QUEBEC TUESDAY. THE ECMWF PRODUCES A TRIPLE POINT
LOW OVER NEW JERSEY OFF THE MAIN LOW IN QUEBEC AND TRANSLATES THE
TRIPLE POINT LOW ALONG THE SOUTHERN NEW ENGLAND COAST. THE GFS
DEPICTS NO SUCH REDEVELOPMENT BUT KEEPS A STRONG SOUTHERLY FLOW
AHEAD OF THE COLD FRONT EXTENDING FROM THE QUEBEC LOW. THESE
DIFFERENCES COULD AFFECT THE OVERALL NATURE OF THE RAIN /WHETHER ITS
MORE STRATIFORM OR SHOWERY/ BUT REGARDLESS OF THE NATURE OR THE TYPE
OF SYSTEM...TUESDAY IS LIKELY TO BE WET. MODELS HINT THAT THE RAIN
COULD MOVE INTO OUR WESTERN ZONES LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT THE BULK OF THE RAIN APPEARS TO HOLD OFF TIL
AFTER 12Z TUESDAY. RAIN CONTINUES THROUGH TUESDAY INTO THE FIRST
PART OF THE DAY ON WEDNESDAY BUT THEN WILL TAPER OFF AS EITHER THE
FRONT MOVES THROUGH OR THE LOW PRESSURE EJECTS TOWARDS THE MARITIMES.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY WITH A POSSIBILITY OF A
FEW DIURNAL SHOWERS HERE AND THERE EACH DAY. TEMPERATURES ARE
EXPECTED TO BE BELOW TO NEAR NORMAL UNTIL THE WEEKEND WHEN DEPENDING
ON THE MODEL COULD SEE A RETURN TO AUGUST HEAT AND HUMIDITY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
18Z UPDATE...HIGH CONFIDENCE.
VFR THIS AFTERNOON AND TONIGHT WITH LIGHT N/NE WINDS. SEA BREEZE
ALONG E MA COAST THIS AFTERNOON WHICH KEEP WINDS MORE E OR SE.
SHOULD SEE MVFR CIGS SPREAD FROM OCEAN ONTO CAPE COD AND ISLANDS
EARLY SUN MORNING. SOME QUESTION AS TO WHETHER OR NOT CIGS SCT OUT
OR LIFT TO VFR SUN AFTERNOON. FOR NOW WE THINK CIGS WILL REMAIN
MVFR THROUGH MUCH OF DAY AND INTO SUN NIGHT. OTHERWISE VFR
ELSEWHERE WITH BRIEF SHOWER POSSIBLE ACROSS NW MA SUN AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR/IFR
CIGS/VSBYS ENTERING WESTERN ZONES LATE MONDAY NIGHT WITH -RA.
TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY IN
WIDESPREAD RAIN/FOG.
WEDNESDAY...MODERATE CONFIDENCE. LINGERING MVFR/IFR CONDITIONS IN
DEPARTING RAIN. IMPROVING CONDITIONS THROUGH THE DAY.
THURSDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF
BRIEF MVFR CONDITIONS IN DIURNAL -SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH SUN NIGHT.
DROPPED SCA ON OUTER S COASTAL WATERS WHERE SEAS HAVE SUBSIDED.
LIGHT N/NE WINDS GIVE WAY TO INCREASING NE WINDS SUN AND
ESPECIALLY SUN NIGHT...AS LOW PRESSURE PASSES WELL SE OF NEW
ENGLAND. SEAS SHOULD BEGIN TO BUILD LATER IN DAY AND COULD REACH 5
FT BY SUN NIGHT E AND S OF NANTUCKET...WHICH MAY REQUIRE SCA IN
LATER FORECASTS. DRY WEATHER EXPECTED THROUGH PERIOD.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE
BUILDS OVER THE WATERS.
TUESDAY...MODERATE CONFIDENCE. WINDS AND SEAS INCREASE AS EITHER A
COLD FRONT OR A LOW PRESSURE SYSTEM MOVE OVER THE WATERS. SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SEAS IF NOT WINDS AS
WELL. VISIBILITIES MAY BE LIMITED AT TIMES IN RAIN.
WEDNESDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS LOW
PRESSURE PULLS AWAY FROM SOUTHERN NEW ENGLAND.
THURSDAY...MODERATE CONFIDENCE. QUIET BOATING WEATHER EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RLG/JWD
NEAR TERM...JWD
SHORT TERM...JWD
LONG TERM...RLG
AVIATION...RLG/JWD
MARINE...RLG/JWD
AREA FORECAST DISCUSSION
NWS TAUNTON MA
128 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THIS AFTERNOON AS LOW
PRESSURE REMAINS WELL OFFSHORE. A SPOT SHOWER IS POSSIBLE ON
SUNDAY. DRY WEATHER LINGERS INTO MONDAY. A LOW PRESSURE WILL
RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MONDAY
NIGHT INTO WEDNESDAY. A TREND TOWARD DRIER WEATHER IS LIKELY
THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
130 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU. COASTAL LOW IS THROWING BACK SOME PATCHY
MID AND HIGH CLOUDS NEAR S COAST BUT DO NOT EXPECT THAT TO BE MUCH
OF AN ISSUE.
FORECAST HIGHS IN 70S/LOWER 80S ON TRACK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
SECONDARY LOW PRES WILL ONCE AGAIN SLIDE WELL S OF THE REGION. THE
INCREASE IN ISALLOBARIC FLOW WILL KEEP INTERIOR WINDS A BIT HIGHER
AND LEFTOVER CLOUDS ARE LIKELY TO LEAD TO WARMER MINS...ALTHOUGH
STILL IN THE UPPER 50S AND LOW 60S. DRY WX REMAINS THOUGH AS THE
PRECIP SHIELD SHOULD REMAIN WELL SE OF THE REGION...EVEN ACK.
SUN...
A BIT TRICKIER FORECAST FOR SUN. THERE ARE DIFFERENCES IN QPF
OUTPUT ACROSS THE INTERIOR OF MA/CT. NAM/MESOSCALE GUIDANCE IS
MOST ROBUST WHILE GFS/ECMWF ARE DRIER. THIS IS REFLECTED IN BUFKIT
SOUNDINGS...WITH NAM MORE MOIST AND AND GFS DRIER. PWATS ARE
DIFFERENT ALSO...WITH NEARLY 1 STD DEVIATION ABOVE NORMAL IN THE
NAM...NEAR NORMAL IN THE GFS/ECMWF. THERE IS A LIFT SOURCE IN THE
FORM OF A WEAK...BUT FAST MOVING SHORTWAVE WHICH SHOW SOME TIMING
DIFFERENCES. THEREFORE...CAN/T RULE OUT A SPOT SHOWER MAINLY FOR
WRN MA OR CT...BUT THE PRECIP SHIELD ASSOCIATED WITH LOW PRES
OFFSHORE REMAINS OFFSHORE. HOWEVER...CHANCE POPS WILL BE THE MAX
AS THEY ARE LIKELY TO BE FAIRLY SCATTERED AND RELATIVELY LIGHT
GIVEN THE LOWER END PWATS.
WILL ALSO INCLUDE THUNDER AS EACH MODEL SHOWS MODEST SFC
CAPE...PARTICULARLY IF THE NAM VERIFIES.
TEMPS REMAIN BELOW NORMAL UNDER RENEWED NE FLOW WITH LOW PRES NEAR
THE BENCHMARK. RANG BETWEEN LOW 70S AND LOW 80S EXPECTED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...
* SCATTERED SHOWERS/T-STORMS AT TIMES LATE MONDAY INTO WEDNESDAY
* TEMPERATURES NEAR OR SLIGHTLY LOWER THAN NORMAL
SYNOPTIC OVERVIEW...
BROAD...FLAT MID-LEVEL FLOW OVER THE NORTHERN USA EVENTUALLY
AMPLIFIES INTO A MID-LEVEL TROUGH OVER THE EASTERN USA TOWARD THE
MIDDLE OF NEXT WEEK. THIS RESULTS IN AN ACTIVE PATTERN LATE MONDAY
INTO WEDNESDAY FOR SOUTHERN NEW ENGLAND. ENSEMBLES AND DETERMINISTIC
GUIDANCE ARE IN RATHER GOOD AGREEMENT ON THE LARGE SCALE FLOW...ALONG
WITH THE AMPLITUDE. BUT AS USUAL AT THIS TIME RANGE...ARE
STRUGGLING WITH THE INDIVIDUAL FRONTAL WAVES AND EXACT TIMING.
THUS FOLLOWED A MODEL BLEND FOR THIS PORTION OF THE FORECAST.
DAILY SENSIBLE WEATHER DETAILS...
SUNDAY NIGHT AND MONDAY...MOST OF THE GUIDANCE SUGGESTS DRY
WEATHER...ESPECIALLY FOR RI AND EASTERN MA...WITH A LOW RISK OF
SHOWER/T-STORMS LATE MONDAY FOR WESTERN MA AS MID LEVEL TROUGH
APPROACHES.
TUESDAY AND WEDNESDAY...MID LEVEL TROUGH AND ATTENDING FRONTAL WAVE
APPROACH. INCREASED RISK FOR SHOWERS AND THUNDERSTORMS. VERY MOIST
AIR EXPECTED...WITH DEW POINTS IN THE MID TO UPPER 60S. GIVEN MID
LEVEL TROUGH AMPLITUDE...AT LEAST MODEST FORCING FOR ASCENT IS
EXPECTED. THIS COMBINATION WILL RESULT IN A RISK FOR HEAVY
DOWNPOURS. WIND FIELDS ALOFT ARE MODEST...BUT INSTABILITY APPEARS
MARGINAL. GIVEN THE TIME RANGE HERE A LOW RISK OF STRONG STORMS.
THURSDAY AND FRIDAY...LATEST GUIDANCE CONTINUES TO SUGGEST THE MID
LEVEL TROUGH OVER THE NORTHEAST SHOULD BEGIN TO DEAMPLIFY. THIS WILL
RESULT IN A TREND TOWARD DRIER AND WARMER WEATHER LATE NEXT WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
18Z UPDATE...HIGH CONFIDENCE.
VFR THIS AFTERNOON AND TONIGHT WITH LIGHT N/NE WINDS. SEA BREEZE
ALONG E MA COAST THIS AFTERNOON WHICH KEEP WINDS MORE E OR SE.
SHOULD SEE MVFR CIGS SPREAD FROM OCEAN ONTO CAPE COD AND ISLANDS
EARLY SUN MORNING. SOME QUESTION AS TO WHETHER OR NOT CIGS SCT OUT
OR LIFT TO VFR SUN AFTERNOON. FOR NOW WE THINK CIGS WILL REMAIN
MVFR THROUGH MUCH OF DAY AND INTO SUN NIGHT. OTHERWISE VFR
ELSEWHERE WITH BRIEF SHOWER POSSIBLE ACROSS NW MA SUN AFTERNOON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY THROUGH WEDNESDAY/...
FORECAST CONFIDENCE...HIGH CONFIDENCE MONDAY...THEN MODERATE
CONFIDENCE TUESDAY AND WEDNESDAY.
MONDAY...VFR WITH LOW RISK OF SHOWERS/T-STORMS LATE WESTERN MA/CT
TUESDAY AND WEDNESDAY...UNSETTLED. SCATTERED SHOWERS/THUNDERSTORMS.
MVFR TO IFR POSSIBLE. HEAVY DOWNPOURS POSSIBLE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SUNDAY/...
LIGHT N/NE FLOW THIS AFTERNOON ON WATERS. LEAVING SCA POSTED FOR
SEAS ON OUTER S COASTAL WATERS BUT CERTAINLY LOOKS MARGINAL AND
MAY DROP WITH 4 PM FORECAST.
TONIGHT INTO TOMORROW...MODERATE CONFIDENCE. NORTH TO NORTHEAST
FLOW REMAINS...BUT SHOULD BE GENERALLY BELOW THE 25 KT THRESHOLD
THANKS TO INFLUENCE OF HIGH PRES TO THE N. THIS SHOULD ALSO KEEP
SEAS BELOW 5 FEET...BUT THE PERSISTENT FLOW MAY INCREASE SWELLS
ALONG THE E COAST. FOR NOW...NOT CONFIDENT ENOUGH FOR AN SMALL
CRAFT ADVISORIES...BUT WILL NEED TO WATCH.
OUTLOOK /SUNDAY NIGHT THROUGH WEDNESDAY/...
SUNDAY NIGHT...LIGHT E/NE WINDS. STRONGER WINDS SE OF NANTUCKET. E
SWELLS 3-5 FT.
MONDAY...WEAK HIGH PRESSURE. DRY WEATHER. LIGHT WINDS WITH SUBSIDING
EAST SWELLS.
TUESDAY AND WEDNESDAY...UNSETTLED...WITH SHOWERS AND THUNDERSTORMS
AS A FRONTAL WAVE APPROACHES.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ254-
255.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...JWD
SHORT TERM...DOODY
LONG TERM...BELK
AVIATION...JWD
MARINE...JWD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1009 PM CDT SUN AUG 9 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* LIGHT SOUTH-SOUTHEAST WINDS EVENTUALLY BACKING TO ESE AND
REMAINING BELOW 10 KTS.
* GRADUAL LOWERING OF CIG/VIS THROUGH MVFR/IFR OVERNIGHT. A FEW
SPOTTY SHOWERS POSSIBLE LATE EVENING. IMPROVEMENT FROM IFR/MVFR
EXPECTED DURING MONDAY MORNING.
* NORTHERLY WINDS MONDAY...LIKELY BECOMING NORTHEAST WITH LAKE
BREEZE DURING THE AFTERNOON.
* CHANCE OF ISOLATED/SCATTERED TSRA MONDAY AFTERNOON.
RATZER
//DISCUSSION...UPDATED 00Z...
AREA OF SURFACE LOW PRESSURE OVER THE LOWER MISSOURI VALLEY WILL
CONTINUE TO TRACK SOUTHEAST INTO THE LOWER OHIO VALLEY TONIGHT. TO
THE NORTH...A SERIES OF MINOR MID-LEVEL DISTURBANCES WILL RIPPLE
ACROSS THE FORECAST AREA WITHIN THE ELEVATED FRONTAL ZONE NORTH OF
THE SURFACE FRONT. THIS MAY SUPPORT A FEW SPOTTY SHOWERS ESPECIALLY
FROM CHICAGO AND AREAS SOUTH AND EAST LATER THIS EVENING. AS
MOIST LOW LEVELS COOL NOCTURNALLY...WILL LIKELY SEE DEVELOPMENT OF
LOWER CLOUD DECKS/FOG...WHICH IS EXPECTED TO LOWER THROUGH MVFR
INTO IFR LATER TONIGHT ESPECIALLY FOR ORD/MDW WHERE LIGHT WINDS
EVENTUALLY BECOME MORE EAST/NORTHEAST OFF OF LAKE MICHIGAN.
VARIOUS MODELS ARE FAIRLY INSISTENT IN IFR CONDITIONS...POSSIBLY
EVEN LIFR...DEVELOPING BY THE PRE-DAWN HOURS...WITH IMPROVEMENT
THEN BEGINNING AFTER SUNRISE.
LIGHT GENERALLY SOUTH-SOUTHEAST WINDS SHOULD GRADUALLY SHIFT TO
FROM SOUTHEAST TO THE NORTH-NORTHEAST THROUGH MONDAY MORNING.
WINDS INLAND WILL TREND MORE NNW...THOUGH ORD/MDW/GYY WILL LIKELY
MAINTAIN OR REDEVELOP A NE COMPONENT OFF OF THE LAKE IN THE
AFTERNOON. ANOTHER UPPER DISTURBANCE AND ONLY SLOW DRYING IN THE
LOW LEVELS MAY SUPPORT ISOLATED-SCATTERED TSRA FOR A PERIOD MONDAY
AFTERNOON...POSSIBLY ALONG LAKE BREEZE BOUNDARY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* MEDIUM-HIGH IN WINDS.
* MEDIUM-LOW IN CIG/VIS TRENDS TONIGHT/EARLY MONDAY.
* MEDIUM-LOW IN MONDAY AFTERNOON TSRA.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
RATZER
&&
.MARINE...
251 PM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY MONDAY EVENING. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE
LATE TONIGHT INTO MONDAY MORNING SHIFTING WINDS NORTHERLY. ANOTHER
WEAK LOW WILL MOVE SOUTH OF THE LAKE MONDAY AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE GRADIENT WILL
TIGHTEN BETWEEN THESE TWO FEATURES WITH NORTHERLY WINDS INCREASING
TO 15-25 KTS BY TUESDAY MORNING. AS THE HIGH MOVES EAST...THESE
NORTHERLY WINDS WILL SLOWLY DIMINISH TUESDAY NIGHT INTO WEDNESDAY.
WINDS WILL SHIFT TO THE SOUTHWEST WEDNESDAY NIGHT AS THE HIGH
SETTLES SOUTHEAST OF THE LAKE AND DEPENDING ON HOW STRONG THE
GRADIENT BECOMES...SPEEDS MAY INCREASE INTO THE 15-25KT RANGE
THURSDAY INTO THURSDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
836 PM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 825 PM CDT SUN AUG 9 2015
THE BOUNDARY THAT WAS PRODUCED BY THE STORMS THIS MORNING WAS
LOCATED OVER SOUTHEAST ILLINOIS BACK INTO EAST CENTRAL MISSOURI.
A CLUSTER OF STORMS WAS TRACKING ESE ALONG THIS MESOSCALE FEATURE
AND MAY CLIP OUR FAR SOUTHEAST COUNTIES. MEANWHILE...FURTHER TO
THE NORTHWEST...A WEAK COOL FRONT WAS LOCATED FROM CENTRAL
WISCONSIN SOUTHWEST THROUGH NORTHERN IOWA WITH A BAND OF STORMS
OVER PARTS OF NORTHWEST IOWA. THE ACTUAL SYNOPTIC SCALE COOL
FRONT TO OUR NORTHWEST IS FORECAST TO PUSH ACROSS THE FORECAST
AREA MONDAY MORNING. UNTIL THEN...WILL CONTINUE WITH THE CHANCES
FOR SHOWERS AND STORMS...ESPECIALLY ACROSS THE SOUTH OVERNIGHT
WITH LOWER POPS AS YOU HEAD NORTH OF I-74. WITH THE ADDED MOISTURE
FROM THE RAINFALL TODAY...LIGHT WINDS AND A GRADUAL TREND TOWARDS
CLEARING SKIES LATE TONIGHT...FOG WILL BE A CONCERN AND WILL
CONTINUE TO HOLD WITH THAT IN THE FORECAST THRU MONDAY MORNING.
HAVE MADE SOME MINOR ADJUSTMENTS TO THE RAIN CHANCES...ESPECIALLY
ACROSS THE NORTH AND MADE SOME TWEAKS TO THE SKY COVER FOR THE
LATE NIGHT HOURS. WE SHOULD HAVE THE UPDATE OUT BY 845 PM.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 253 PM CDT SUN AUG 9 2015
BASED ON SURFACE DATA...APPEARS THERE IS A BOUNDARY STRETCHING FROM
NORTHERN MO/SOUTHERN IA INTO NORTHERN PART OF CENTRAL IL.
HOWEVER...THE EFFECTIVE BOUNDARY SHOULD BE MUCH FURTHER SOUTH AS A
RESULT OF THE MCS THAT MOVED ACROSS THE AREA EARLIER THIS MORNING
PUSHING IT SOUTH OF THE CWA. HRRR DOES NOT SHOW ANY PCPN IN THE CWA
TONIGHT...BUT DOES HAVE THE SMALL AREA OF PCPN IN NORTHERN MO MOVING
EAST-SOUTHEAST INTO SOUTHERN IL THIS EVENING. BUT WITH A WEAK
CONVERGENT BOUNDARY IN THE AREA AM INCLINED TO KEEP A CHANCE FOR
POPS IN THE FORECAST FOR TONIGHT. TREND SHOULD BE...AND MODELS DO
SUPPORT THAT THIS WEAK BOUNDARY SHOULD MOVE SOUTH DURING THE
OVERNIGHT PERIOD. SO CHANCE POPS SOUTHEAST OF THE ILLINOIS RIVER
TONIGHT. ENDING OF PCPN CHANCES WILL START ALONG THE RIVER AND THEN
PROGRESS SOUTHEAST THROUGH THE PERIOD. OTHER ISSUE OVERNIGHT WILL BE
FOG DEVELOPMENT. WITH LOTS OF BREAKS IN THE CLOUDS THIS EVENING AND
OVERNIGHT...COMBINED WITH THE ABUNDANCE OF LOW LEVEL MOISTURE FROM
THE RAIN THIS MORNING...AND LIGHT WINDS...BELIEVE FOG WILL DEVELOP
THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. SO HAVE INCLUDED
AREAS OF FOG IN THE FORECAST THE NORTHERN AND CENTRAL PARTS OF THE
AREA. ONLY PLACE WITHOUT ANY FOG WILL BE AREAS SOUTHEAST OF I-70.
OVERNIGHT LOWS AROUND 70S LOOKS REASONABLE WITH COOLEST TEMPS UP
NORTH WHERE MORE BREAKS IN CLOUDS SHOULD BE.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN AUG 9 2015
A FRONTAL BOUNDARY CURRENTLY FROM NORTHERN WISCONSIN TO NORTHERN
NEBRASKA WILL PUSH INTO SOUTHEAST ILLINOIS BY MID MORNING
MONDAY...AIDED BY SEVERAL AREAS OF THUNDERSTORM DEVELOPMENT AHEAD OF
THE FRONT THIS EVENING INTO TONIGHT. THE EFFECTIVE FRONT WILL LIKELY
BE LINGERING IN SOUTHEAST PORTIONS OF THE CENTRAL IL FORECAST AREA
THROUGH THE MORNING AND HAVE CONTINUED PRECIPITATION CHANCES IN THAT
AREA THROUGH NOON. MOST OF THE THUNDERSTORM ACTIVITY WILL TEND TO
MOVE EASTWARD THROUGH THE DAY...HOWEVER AN UPPER LEVEL SHORTWAVE
WILL APPROACH FROM THE NORTHWEST BY AFTERNOON...AND LIFT ASSOCIATED
WITH THIS FEATURE WILL CAUSE CHANCES FOR SHOWERS AND THUNDERSTORMS
TO RE-DEVELOP FOR AFTERNOON AND EARLY EVENING...MAINLY FROM THE
ILLINOIS RIVER NORTHWESTWARD. HIGHS EXPECTED TO REACH FROM AROUND 81
IN GALESBURG TO THE MID 80S SPRINGFIELD TO PARIS SOUTHWARD WITH
WINDS BECOMING NORTHWEST UP TO 10 MPH.
AFTER THIS FEATURE PASSES THROUGH...DRY CONDITIONS ARE EXPECTED
THROUGH MUCH OF THE WEEK AS A PRONOUNCED UPPER LEVEL RIDGE BUILDS
OVER THE CENTRAL U.S. AND TROUGHING OVER THE NORTHEASTERN U.S. A
COOL NORTHWEST FLOW PATTERN BETWEEN THE RIDGE AND TROUGH WILL BRING
HIGH TEMPERATURES PRIMARILY IN THE LOW 80S AND LOWS IN THE LOW 60S
THROUGH THURSDAY. A COLD FRONT EMBEDDED IN THIS FLOW PATTERN WILL
DROP INTO THE GREAT LAKES/MIDWEST AREA FRIDAY. MODELS CONTINUE SOME
RUN TO RUN INCONSISTENCIES FOR THIS FEATURE...BUT BULK OF GUIDANCE
CONTINUES TO SUGGEST PRECIPITATION ASSOCIATED WITH THIS FEATURE MAY
STRUGGLE TO REACH AS FAR SOUTHWEST AS CENTRAL ILLINOIS.
THEREFORE...HAVE INCORPORATED SLIGHT CHANCES FOR THUNDERSTORMS
MAINLY I-72 NORTHWARD. DRY CONDITIONS SHOULD THEN RETURN THROUGH THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM CDT SUN AUG 9 2015
MAIN CONCERN THIS PERIOD WILL BE WITH COVERAGE OF ANY CONVECTION
THAT MAY REDEVELOP...ESPECIALLY AT SPI AND DEC...AND THE FOG
AND STRATUS THREAT LATER TONIGHT. BOUNDARY LEFT OVER FROM THE
MORNING CONVECTION HAS SLIPPED SOUTH OF THE TAF SITES AND APPEARS
THAT IT WILL BE THE PRIMARY FOCUS FOR SHOWERS AND STORMS TONIGHT.
A SECOND FRONT WELL TO OUR NORTHWEST WILL PUSH INTO OUR AREA
MONDAY MORNING. WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE
THIS EVENING AT SPI AND DEC WITH THE PRIMARY THREAT FOR STORMS
SHIFTING SOUTH OF I72 CLOSER TO I-70 BY LATE EVENING.
THEN THE FOCUS SHIFTS TOWARDS FOG AS ABUNDANT LOW LEVEL MOISTURE
FROM THIS MORNING`S RAIN COMBINED WITH A LIGHT WIND FLOW WILL
BRING ABOUT LOW CIGS AND VSBYS LATE TONIGHT INTO MONDAY MORNING.
MOST OF THE FORECAST MODELS BRING CIGS DOWN TO MVFR WITH SOME
TEMPO IFR CIGS AND VSBYS IN STRATUS AND FOG EARLY MONDAY MORNING
SO WILL CONTINUE FROM PREVIOUS TRENDS IN BRINGING THE VSBYS AND
CIGS DOWN AFTER 03Z. WHAT FOG/STRATUS WE DO SEE OVERNIGHT SHOULD
DISSIPATE BY 13Z WITH SOME SCT-BKN CUMULUS FROM 2500-3500 FEET.
SURFACE WINDS SHOULD BE LIGHT AND VARIABLE TONIGHT AND THEN BECOME
NORTHWEST TO NORTH AT 10 TO 15 KTS BY AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...AUTEN
LONG TERM...ONTON
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
653 PM CDT SUN AUG 9 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* LIGHT SOUTH-SOUTHEAST WINDS EARLY THIS EVENING EVENTUALLY
BACKING TO ESE...BUT REMAINING BELOW 10 KTS.
* GRADUAL LOWERING OF CIG/VIS THROUGH MVFR/IFR LATER THIS EVENING
AND OVERNIGHT. A FEW SPOTTY SHOWERS POSSIBLE LATE EVENING.
IMPROVEMENT FROM IFR/MVFR EXPECTED DURING MONDAY MORNING.
* NORTHERLY WINDS MONDAY...LIKELY BECOMING NORTHEAST WITH LAKE
BREEZE DURING THE AFTERNOON.
* CHANCE OF ISOLATED/SCATTERED TSRA MONDAY AFTERNOON.
RATZER
//DISCUSSION...UPDATED 00Z...
AREA OF SURFACE LOW PRESSURE OVER THE LOWER MISSOURI VALLEY WILL
CONTINUE TO TRACK SOUTHEAST INTO THE LOWER OHIO VALLEY TONIGHT. TO
THE NORTH...A SERIES OF MINOR MID-LEVEL DISTURBANCES WILL RIPPLE
ACROSS THE FORECAST AREA WITHIN THE ELEVATED FRONTAL ZONE NORTH OF
THE SURFACE FRONT. THIS MAY SUPPORT A FEW SPOTTY SHOWERS ESPECIALLY
FROM CHICAGO AND AREAS SOUTH AND EAST LATER THIS EVENING. AS
MOIST LOW LEVELS COOL NOCTURNALLY...WILL LIKELY SEE DEVELOPMENT OF
LOWER CLOUD DECKS/FOG...WHICH IS EXPECTED TO LOWER THROUGH MVFR
INTO IFR LATER TONIGHT ESPECIALLY FOR ORD/MDW WHERE LIGHT WINDS
EVENTUALLY BECOME MORE EAST/NORTHEAST OFF OF LAKE MICHIGAN.
VARIOUS MODELS ARE FAIRLY INSISTENT IN IFR CONDITIONS...POSSIBLY
EVEN LIFR...DEVELOPING BY THE PRE-DAWN HOURS...WITH IMPROVEMENT
THEN BEGINNING AFTER SUNRISE.
LIGHT GENERALLY SOUTH-SOUTHEAST WINDS SHOULD GRADUALLY SHIFT TO
FROM SOUTHEAST TO THE NORTH-NORTHEAST THROUGH MONDAY MORNING.
WINDS INLAND WILL TREND MORE NNW...THOUGH ORD/MDW/GYY WILL LIKELY
MAINTAIN OR REDEVELOP A NE COMPONENT OFF OF THE LAKE IN THE
AFTERNOON. ANOTHER UPPER DISTURBANCE AND ONLY SLOW DRYING IN THE
LOW LEVELS MAY SUPPORT ISOLATED-SCATTERED TSRA FOR A PERIOD MONDAY
AFTERNOON...POSSIBLY ALONG LAKE BREEZE BOUNDARY.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM-HIGH IN WINDS.
* MEDIUM IN CIG/VIS TRENDS TONIGHT/EARLY MONDAY.
* MEDIUM-LOW IN MONDAY AFTERNOON TSRA.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
RATZER
&&
.MARINE...
251 PM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY MONDAY EVENING. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE
LATE TONIGHT INTO MONDAY MORNING SHIFTING WINDS NORTHERLY. ANOTHER
WEAK LOW WILL MOVE SOUTH OF THE LAKE MONDAY AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE GRADIENT WILL
TIGHTEN BETWEEN THESE TWO FEATURES WITH NORTHERLY WINDS INCREASING
TO 15-25 KTS BY TUESDAY MORNING. AS THE HIGH MOVES EAST...THESE
NORTHERLY WINDS WILL SLOWLY DIMINISH TUESDAY NIGHT INTO WEDNESDAY.
WINDS WILL SHIFT TO THE SOUTHWEST WEDNESDAY NIGHT AS THE HIGH
SETTLES SOUTHEAST OF THE LAKE AND DEPENDING ON HOW STRONG THE
GRADIENT BECOMES...SPEEDS MAY INCREASE INTO THE 15-25KT RANGE
THURSDAY INTO THURSDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
601 PM CDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 253 PM CDT SUN AUG 9 2015
BASED ON SURFACE DATA...APPEARS THERE IS A BOUNDARY STRETCHING FROM
NORTHERN MO/SOUTHERN IA INTO NORTHERN PART OF CENTRAL IL.
HOWEVER...THE EFFECTIVE BOUNDARY SHOULD BE MUCH FURTHER SOUTH AS A
RESULT OF THE MCS THAT MOVED ACROSS THE AREA EARLIER THIS MORNING
PUSHING IT SOUTH OF THE CWA. HRRR DOES NOT SHOW ANY PCPN IN THE CWA
TONIGHT...BUT DOES HAVE THE SMALL AREA OF PCPN IN NORTHERN MO MOVING
EAST-SOUTHEAST INTO SOUTHERN IL THIS EVENING. BUT WITH A WEAK
CONVERGENT BOUNDARY IN THE AREA AM INCLINED TO KEEP A CHANCE FOR
POPS IN THE FORECAST FOR TONIGHT. TREND SHOULD BE...AND MODELS DO
SUPPORT THAT THIS WEAK BOUNDARY SHOULD MOVE SOUTH DURING THE
OVERNIGHT PERIOD. SO CHANCE POPS SOUTHEAST OF THE ILLINOIS RIVER
TONIGHT. ENDING OF PCPN CHANCES WILL START ALONG THE RIVER AND THEN
PROGRESS SOUTHEAST THROUGH THE PERIOD. OTHER ISSUE OVERNIGHT WILL BE
FOG DEVELOPMENT. WITH LOTS OF BREAKS IN THE CLOUDS THIS EVENING AND
OVERNIGHT...COMBINED WITH THE ABUNDANCE OF LOW LEVEL MOISTURE FROM
THE RAIN THIS MORNING...AND LIGHT WINDS...BELIEVE FOG WILL DEVELOP
THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. SO HAVE INCLUDED
AREAS OF FOG IN THE FORECAST THE NORTHERN AND CENTRAL PARTS OF THE
AREA. ONLY PLACE WITHOUT ANY FOG WILL BE AREAS SOUTHEAST OF I-70.
OVERNIGHT LOWS AROUND 70S LOOKS REASONABLE WITH COOLEST TEMPS UP
NORTH WHERE MORE BREAKS IN CLOUDS SHOULD BE.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN AUG 9 2015
A FRONTAL BOUNDARY CURRENTLY FROM NORTHERN WISCONSIN TO NORTHERN
NEBRASKA WILL PUSH INTO SOUTHEAST ILLINOIS BY MID MORNING
MONDAY...AIDED BY SEVERAL AREAS OF THUNDERSTORM DEVELOPMENT AHEAD OF
THE FRONT THIS EVENING INTO TONIGHT. THE EFFECTIVE FRONT WILL LIKELY
BE LINGERING IN SOUTHEAST PORTIONS OF THE CENTRAL IL FORECAST AREA
THROUGH THE MORNING AND HAVE CONTINUED PRECIPITATION CHANCES IN THAT
AREA THROUGH NOON. MOST OF THE THUNDERSTORM ACTIVITY WILL TEND TO
MOVE EASTWARD THROUGH THE DAY...HOWEVER AN UPPER LEVEL SHORTWAVE
WILL APPROACH FROM THE NORTHWEST BY AFTERNOON...AND LIFT ASSOCIATED
WITH THIS FEATURE WILL CAUSE CHANCES FOR SHOWERS AND THUNDERSTORMS
TO RE-DEVELOP FOR AFTERNOON AND EARLY EVENING...MAINLY FROM THE
ILLINOIS RIVER NORTHWESTWARD. HIGHS EXPECTED TO REACH FROM AROUND 81
IN GALESBURG TO THE MID 80S SPRINGFIELD TO PARIS SOUTHWARD WITH
WINDS BECOMING NORTHWEST UP TO 10 MPH.
AFTER THIS FEATURE PASSES THROUGH...DRY CONDITIONS ARE EXPECTED
THROUGH MUCH OF THE WEEK AS A PRONOUNCED UPPER LEVEL RIDGE BUILDS
OVER THE CENTRAL U.S. AND TROUGHING OVER THE NORTHEASTERN U.S. A
COOL NORTHWEST FLOW PATTERN BETWEEN THE RIDGE AND TROUGH WILL BRING
HIGH TEMPERATURES PRIMARILY IN THE LOW 80S AND LOWS IN THE LOW 60S
THROUGH THURSDAY. A COLD FRONT EMBEDDED IN THIS FLOW PATTERN WILL
DROP INTO THE GREAT LAKES/MIDWEST AREA FRIDAY. MODELS CONTINUE SOME
RUN TO RUN INCONSISTENCIES FOR THIS FEATURE...BUT BULK OF GUIDANCE
CONTINUES TO SUGGEST PRECIPITATION ASSOCIATED WITH THIS FEATURE MAY
STRUGGLE TO REACH AS FAR SOUTHWEST AS CENTRAL ILLINOIS.
THEREFORE...HAVE INCORPORATED SLIGHT CHANCES FOR THUNDERSTORMS
MAINLY I-72 NORTHWARD. DRY CONDITIONS SHOULD THEN RETURN THROUGH THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM CDT SUN AUG 9 2015
MAIN CONCERN THIS PERIOD WILL BE WITH COVERAGE OF ANY CONVECTION
THAT MAY REDEVELOP...ESPECIALLY AT SPI AND DEC...AND THE FOG
AND STRATUS THREAT LATER TONIGHT. BOUNDARY LEFT OVER FROM THE
MORNING CONVECTION HAS SLIPPED SOUTH OF THE TAF SITES AND APPEARS
THAT IT WILL BE THE PRIMARY FOCUS FOR SHOWERS AND STORMS TONIGHT.
A SECOND FRONT WELL TO OUR NORTHWEST WILL PUSH INTO OUR AREA
MONDAY MORNING. WIDELY SCATTERED THUNDERSTORMS WILL BE POSSIBLE
THIS EVENING AT SPI AND DEC WITH THE PRIMARY THREAT FOR STORMS
SHIFTING SOUTH OF I72 CLOSER TO I-70 BY LATE EVENING.
THEN THE FOCUS SHIFTS TOWARDS FOG AS ABUNDANT LOW LEVEL MOISTURE
FROM THIS MORNING`S RAIN COMBINED WITH A LIGHT WIND FLOW WILL
BRING ABOUT LOW CIGS AND VSBYS LATE TONIGHT INTO MONDAY MORNING.
MOST OF THE FORECAST MODELS BRING CIGS DOWN TO MVFR WITH SOME
TEMPO IFR CIGS AND VSBYS IN STRATUS AND FOG EARLY MONDAY MORNING
SO WILL CONTINUE FROM PREVIOUS TRENDS IN BRINGING THE VSBYS AND
CIGS DOWN AFTER 03Z. WHAT FOG/STRATUS WE DO SEE OVERNIGHT SHOULD
DISSIPATE BY 13Z WITH SOME SCT-BKN CUMULUS FROM 2500-3500 FEET.
SURFACE WINDS SHOULD BE LIGHT AND VARIABLE TONIGHT AND THEN BECOME
NORTHWEST TO NORTH AT 10 TO 15 KTS BY AFTERNOON.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AUTEN
LONG TERM...ONTON
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT SAT AUG 8 2015
.SHORT TERM...
320 PM CDT
THROUGH SUNDAY...
MAIN CONCERN IS WITH CONVECTIVE POTENTIAL LATE TONIGHT INTO
SUNDAY. RAOBS AND AIRCRAFT SOUNDINGS TODAY SHOWED AN ENVIRONMENT
HOSTILE TO PRECIP MAINTENANCE. THEREFORE DESPITE SOME FORCING FROM
A CONVECTIVELY INDUCED SHORTWAVE OVERHEAD...LIGHT RADAR ECHOES
OVER AREA ARE LIKELY VIRGA AND HAVE PULLED MENTION OF SPRINKLES
THE REST OF TODAY. CONVERGENT AXIS IN FRONTAL ZONE OF DISSIPATING
WEAK LOW OVER SOUTHERN LAKE MICHIGAN DID INITIATIVE SOME
CONVECTION OVER NORTH CENTRAL INDIANA...AND WOULD EXPECT FURTHER
DEVELOPMENT TO REMAIN EAST OF THE CWA. OVERALL...WITH PLENTY OF
CLOUD COVER WELL BACK TO THE WEST...INCLUDING PATCHY LOWER CLOUDS
IN SPOTS...JUST EXPECTING A MOSTLY CLOUDY REST OF THE DAY INTO
TONIGHT. VERY WEAK GRADIENT WILL YIELD LIGHT/CALM WINDS OVERNIGHT
AND LOW DEWPOINT SPREADS COULD SET STAGE FOR SOME PATCHY FOG OR
HAZE. LOW TEMPS WILL BE IN THE MID 60S TO AROUND 70.
FOCUS LATE TONIGHT INTO SUNDAY WILL BE ON MCS EXPECTED TO DEVELOP
OVER EASTERN NEBRASKA AND WESTERN IOWA THIS EVENING. MCS IS LIKELY
TO RIDE ALONG INSTABILITY AXIS THAT WILL MAINLY BE SOUTH OF THE
CWA OFF TO THE EAST-SOUTHEAST INTO SUNDAY MORNING. CONSENSUS OF
MODEL GUIDANCE IS TO KEEP INSTABILITY MINIMAL AT BEST FOR MUCH OF
THE CWA...LIMITING THUNDER POTENTIAL. CANNOT COMPLETELY RULE OUT
THUNDER GIVEN MODEST LOW LEVEL JET/WAA REGIME. RECENT HI-RES
CAMS...INCLUDING 4KM NAM AND EXPERIMENTAL HRRR DEPICT A REASONABLE
SCENARIO IN WHICH STRATIFORM NORTH OF MCS OVERSPREADS MUCH OF CWA
FROM WESTNORTHWEST TO EAST SOUTHEAST AFTER MIDNIGHT THROUGH MID
SUNDAY MORNING/BY WHICH TIME IT WILL PROBABLY BE DECAYING. HAVE
FOCUSED CATEGORICAL POPS INTO SOUTHERN CWA WHERE CONFIDENCE IS
HIGHEST IN WIDESPREAD COVERAGE. ITS POSSIBLE FAR NORTHEAST CWA
COULD SEE LITTLE OR NO RAIN. BEST CHANCE FOR HEAVY DOWNPOURS LOOKS
TO BE IN FAR SOUTHERN CWA WHERE MORE ROBUST CONVECTION COULD PASS
THROUGH...THOUGH ANY THREAT FOR STRONG TO SEVERE STORMS SHOULD
STAY SOUTHWEST OF THE CWA GIVEN ANTICIPATED DECAYING TREND OF MCS.
A GOOD DEAL OF UNCERTAINTY THE REMAINDER OF SUNDAY REGARDING
CONVECTIVE TRENDS. A SURFACE LOW LOOKS TO EVOLVE EASTWARD INTO THE
MID MISSISSIPPI VALLEY BY LATER IN THE DAY...WITH RETURN FLOW AND
WEST-SOUTHWEST LLJ ALSO DEVELOPING. LINGERING CLOUD COVER WILL
LIMIT DESTABILIZATION AND THUNDER POTENTIAL...ESPECIALLY FARTHER
NORTH UNTIL LATE DAY. ANOTHER SHORTWAVE WILL APPROACH FROM WEST IN
LATE AFTERNOON AND THERE SHOULD BE ENOUGH 925-850 MB MOISTURE
CONVERGENCE TO SUPPORT CHANCE POPS NORTH OF I-80 AND LIKELIESSOUTH
OF I-80. MODERATE WESTERLY MIDLEVEL FLOW WILL RESULT IN 30-40 KT
OF WEST-NORTHWEST 0-6KM SHEAR. THIS WILL SUPPORT SOME THREAT FOR
STRONG TO SEVERE STORMS WELL SOUTH OF I-80 CLOSER TO EXPECTED
TRACK OF SFC LOW AND WHERE TEMPS AROUND 80 AND LOW-MID 70S
DEWPOINTS COULD BRING SLIGHTLY BETTER INSTABILITY. MAIN THREAT
WOULD BE GUSTY TO DAMAGING WINDS...AS HAIL APPEARS UNLIKELY WITH
700-500 MB LAPSE RATES LESS THAN 6 CELSIUS PER KM. SUNDAY OVERALL
WILL BE A CLOUDY AND MUGGY DAY...WITH HIGHS IN THE MID 70S TO
AROUND 80.
RC
&&
.LONG TERM...
320 PM CDT
SUNDAY NIGHT THROUGH SATURDAY...
THE BEST CHANCE FOR PRECIP IN THE EXTENDED WILL BE SUNDAY EVENING
THROUGH MONDAY AFTERNOON...WITH VERY SLIGHT CHANCES OF PRECIP LATE
NEXT WEEK.
A COMPLEX OF STORMS WILL BE DIMINISHING OVER THE REGION SUNDAY
EVENING AND NIGHT. THE UPPER LEVEL VORTICITY PATTERN IS VERY CHAOTIC
WITH GUIDANCE INDICATING THE MAIN MCV WILL BE OVER CENTRAL IL AND
VORT STREAMERS ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE OVER
WISCONSIN. WITH SUCH A MESSY PATTERN...DECIDED TO ONLY MAKE MINOR
ADJUSTMENTS TO PRECIP CHANCES SUNDAY NIGHT. HAVE A CHANCE OF
THUNDERSTORMS ALONG AND EAST OF I-39 WITH BETTER CHANCES EAST OF I-
55. COULD SEE A FEW STRONG TO SEVERE STORMS SOUTH OF I-80 BUT
CONDITIONS WILL BE WEAKENING AS THE EVENING PROGRESSES.
OVERALL...HAVE LOW CONFIDENCE IN EXACTLY HOW SUNDAY NIGHT WILL PLAY
OUT DUE TO SO MANY MESOSCALE FEATURES AND WHETHER OR NOT THE
ATMOSPHERE WILL BE ABLE TO RECOVER FROM SUNDAY MORNING/S STORMS.
A SHORT WAVE MOVING WITH THE UPPER LEVEL TROUGH ROTATES THROUGH
MONDAY WITH A DECENT VORTICITY STREAMER. WENT WITH A CHANCE OF
SHOWERS AND STORMS MAINLY NORTH OF I-80 MONDAY. THINKING THE NAM IS
ONCE AGAIN TOO MOIST LEADING TO TOO MUCH CONVECTIVE DEVELOPMENT.
THINKING SHOWERS AND STORMS WILL DRIFT SOUTH OF THE IL/WI STATE LINE
MONDAY AFTERNOON AND THEN WEAKEN AS THEY CONTINUE TO SHIFT SOUTH
MONDAY EVENING. MONDAY EVENING MAY END UP BEING DRY...BUT DID NOT
HAVE ENOUGH CONFIDENCE IN A DRY FORECAST SO KEPT A SLIGHT CHANCE OF
SHOWERS AND STORMS ALONG AND SOUTH OF I-80 MONDAY EVENING.
THE UPPER LEVEL TROUGH AXIS SHIFTS EAST THROUGH WISCONSIN WITH
COOLER UPPER LEVEL AIR SINKING SOUTH THROUGH THE REGION. HIGH
PRESSURE THEN BUILDS IN FOR WEDNESDAY AND THURSDAY LEADING TO DRY
CONDITIONS THROUGH THURSDAY. HIGH TEMPS TUESDAY WILL BE AROUND
80...THEN IN THE UPPER 70S WEDNESDAY. LAKE BREEZES BOTH DAYS WILL
KEEP LOCATIONS ALONG THE LAKE IN THE MID 70S. TEMPS REBOUND INTO
THE LOW TO MID 80S THURSDAY WITH NO LAKE COOLING.
THE NEXT LOW PRESSURE SYSTEM MOVES OVER JAMES BAY THURSDAY EVENING
AND PUSHES THE HIGH PRESSURE SOUTH OVER THE OHIO VALLEY. THE LOWS
COLD FRONT SINKS SOUTH OVER FAR NORTHERN IL FRIDAY AFTERNOON SO HAVE
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND STORMS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WIND SHIFT TO NE AT ORD EXPECTED BY 00Z...PREVAILING SPEED
ANTICIPATED TO BE NEAR BUT JUST UNDER 10 KTS.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE SUNDAY.
MM/RATZER
//DISCUSSION...UPDATED 22Z...
LAKE BREEZE PUSHED INLAND SOUTH OF ORD...THOUGH COMPLEX NATURE OF
SFC PRESSURE GRADIENT ASSOCIATED WITH WEAK LOW MOVING SOUTHEAST
ACROSS LAKE MICHIGAN HAS HELD LAKE BREEZE EAST OF ORD THROUGH LATE
AFTERNOON. THIS WILL CHANGE NEXT 1-2 HOURS AS LARGER SCALE FLOW
PATTERN WHICH WAS SHIFTING TO THE NORTH...FLIPS OVER TO THE
NORTHEAST. WIND HAS SHIFTED AT KUGN...AND CAN BEGIN TO SEE
BOUNDARY MOVING SOUTHWEST IN TORD TDWR REFLECTIVITY OVER SOUTHEAST
LAKE CO IL. EXTRAPOLATION OF THIS FEATURE SUGGEST 2330-0000Z SHIFT
TO NORTHEAST FOR ORD. AS WITH MANY LAKE BREEZE/DENSITY CURRENTS...
SPEED MAY FLIRT WITH THE 10-15 KT RANGE BRIEFLY...THOUGH FORECAST
SOUNDINGS DEPICT WINDS LESS THAN 10 KTS THROUGH MIXED LAYER AND
EXPECTATION IS THAT PREVAILING WIND SPEED WILL BE JUST UNDER 10
KTS.
RATZER
PREVIOUS DISCUSSION FROM 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO- CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE SHORE
AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH IN WINDS
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
320 PM CDT
HIGH PRESSURE STRETCHES FROM QUEBEC THROUGH THE OHIO VALLEY WHILE
LOW PRESSURE IS OVER MANITOBA. BOTH SYSTEMS WILL SHIFT EAST WITH THE
LOW REACHING JAMES BAY BY MONDAY MORNING. AS SUCH LIGHT NORTHEAST
WINDS BECOME SOUTH TO SOUTHEAST SUNDAY. THE TROUGH ASSOCIATED WITH
THE LOWS COLD/STATIONARY FRONT SHIFTS THROUGH LATE SUNDAY NIGHT INTO
MONDAY MORNING WITH WINDS BECOMING NORTH BEHIND IT. A WEAK CLOSED
LOW FORMS OVER THE EASTERN GREAT LAKES MONDAY EVENING AND DEEPENS AS
IT SHIFTS NORTHEAST. AT THE SAME TIME HIGH PRESSURE WILL BE PUSHING
EAST OVER THE WESTERN GREAT LAKES. THIS WILL LEAD TO NORTH WINDS
INCREASING TO 10 TO 20 KT MONDAY NIGHT THROUGH TUESDAY NIGHT. WINDS
WEAKEN WEDNESDAY WITH THE HIGH OVERHEAD...AND THEN BACK TO SOUTHWEST
AS THE HIGH IS PUSHED SOUTH BY THE NEXT LOW OVER JAMES BAY THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
321 PM CDT SAT AUG 8 2015
.SHORT TERM...
320 PM CDT
THROUGH SUNDAY...
MAIN CONCERN IS WITH CONVECTIVE POTENTIAL LATE TONIGHT INTO
SUNDAY. RAOBS AND AIRCRAFT SOUNDINGS TODAY SHOWED AN ENVIRONMENT
HOSTILE TO PRECIP MAINTENANCE. THEREFORE DESPITE SOME FORCING FROM
A CONVECTIVELY INDUCED SHORTWAVE OVERHEAD...LIGHT RADAR ECHOES
OVER AREA ARE LIKELY VIRGA AND HAVE PULLED MENTION OF SPRINKLES
THE REST OF TODAY. CONVERGENT AXIS IN FRONTAL ZONE OF DISSIPATING
WEAK LOW OVER SOUTHERN LAKE MICHIGAN DID INITIATIVE SOME
CONVECTION OVER NORTH CENTRAL INDIANA...AND WOULD EXPECT FURTHER
DEVELOPMENT TO REMAIN EAST OF THE CWA. OVERALL...WITH PLENTY OF
CLOUD COVER WELL BACK TO THE WEST...INCLUDING PATCHY LOWER CLOUDS
IN SPOTS...JUST EXPECTING A MOSTLY CLOUDY REST OF THE DAY INTO
TONIGHT. VERY WEAK GRADIENT WILL YIELD LIGHT/CALM WINDS OVERNIGHT
AND LOW DEWPOINT SPREADS COULD SET STAGE FOR SOME PATCHY FOG OR
HAZE. LOW TEMPS WILL BE IN THE MID 60S TO AROUND 70.
FOCUS LATE TONIGHT INTO SUNDAY WILL BE ON MCS EXPECTED TO DEVELOP
OVER EASTERN NEBRASKA AND WESTERN IOWA THIS EVENING. MCS IS LIKELY
TO RIDE ALONG INSTABILITY AXIS THAT WILL MAINLY BE SOUTH OF THE
CWA OFF TO THE EAST-SOUTHEAST INTO SUNDAY MORNING. CONSENSUS OF
MODEL GUIDANCE IS TO KEEP INSTABILITY MINIMAL AT BEST FOR MUCH OF
THE CWA...LIMITING THUNDER POTENTIAL. CANNOT COMPLETELY RULE OUT
THUNDER GIVEN MODEST LOW LEVEL JET/WAA REGIME. RECENT HI-RES
CAMS...INCLUDING 4KM NAM AND EXPERIMENTAL HRRR DEPICT A REASONABLE
SCENARIO IN WHICH STRATIFORM NORTH OF MCS OVERSPREADS MUCH OF CWA
FROM WESTNORTHWEST TO EAST SOUTHEAST AFTER MIDNIGHT THROUGH MID
SUNDAY MORNING/BY WHICH TIME IT WILL PROBABLY BE DECAYING. HAVE
FOCUSED CATEGORICAL POPS INTO SOUTHERN CWA WHERE CONFIDENCE IS
HIGHEST IN WIDESPREAD COVERAGE. ITS POSSIBLE FAR NORTHEAST CWA
COULD SEE LITTLE OR NO RAIN. BEST CHANCE FOR HEAVY DOWNPOURS LOOKS
TO BE IN FAR SOUTHERN CWA WHERE MORE ROBUST CONVECTION COULD PASS
THROUGH...THOUGH ANY THREAT FOR STRONG TO SEVERE STORMS SHOULD
STAY SOUTHWEST OF THE CWA GIVEN ANTICIPATED DECAYING TREND OF MCS.
A GOOD DEAL OF UNCERTAINTY THE REMAINDER OF SUNDAY REGARDING
CONVECTIVE TRENDS. A SURFACE LOW LOOKS TO EVOLVE EASTWARD INTO THE
MID MISSISSIPPI VALLEY BY LATER IN THE DAY...WITH RETURN FLOW AND
WEST-SOUTHWEST LLJ ALSO DEVELOPING. LINGERING CLOUD COVER WILL
LIMIT DESTABILIZATION AND THUNDER POTENTIAL...ESPECIALLY FARTHER
NORTH UNTIL LATE DAY. ANOTHER SHORTWAVE WILL APPROACH FROM WEST IN
LATE AFTERNOON AND THERE SHOULD BE ENOUGH 925-850 MB MOISTURE
CONVERGENCE TO SUPPORT CHANCE POPS NORTH OF I-80 AND LIKELIKES
SOUTH OF I-80. MODERATE WESTERLY MIDLEVEL FLOW WILL RESULT IN
30-40 KT OF WEST-NORTHWEST 0-6KM SHEAR. THIS WILL SUPPORT SOME
THREAT FOR STRONG TO SEVERE STORMS WELL SOUTH OF I-80 CLOSER TO
EXPECTED TRACK OF SFC LOW AND WHERE TEMPS AROUND 80 AND LOW-MID
70S DEWPOINTS COULD BRING SLIGHTLY BETTER INSTABILITY. MAIN THREAT
WOULD BE GUSTY TO DAMAGING WINDS...AS HAIL APPEARS UNLIKELY WITH
700-500 MB LAPSE RATES LESS THAN 6 CELSIUS PER KM. SUNDAY OVERALL
WILL BE A CLOUDY AND MUGGY DAY...WITH HIGHS IN THE MID 70S TO
AROUND 80.
RC
&&
.LONG TERM...
320 PM CDT
SUNDAY NIGHT THROUGH SATURDAY...
THE BEST CHANCE FOR PRECIP IN THE EXTENDED WILL BE SUNDAY EVENING
THROUGH MONDAY AFTERNOON...WITH VERY SLIGHT CHANCES OF PRECIP LATE
NEXT WEEK.
A COMPLEX OF STORMS WILL BE DIMINISHING OVER THE REGION SUNDAY
EVENING AND NIGHT. THE UPPER LEVEL VORTICITY PATTERN IS VERY CHAOTIC
WITH GUIDANCE INDICATING THE MAIN MCV WILL BE OVER CENTRAL IL AND
VORT STREAMERS ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE OVER
WISCONSIN. WITH SUCH A MESSY PATTERN...DECIDED TO ONLY MAKE MINOR
ADJUSTMENTS TO PRECIP CHANCES SUNDAY NIGHT. HAVE A CHANCE OF
THUNDERSTORMS ALONG AND EAST OF I-39 WITH BETTER CHANCES EAST OF I-
55. COULD SEE A FEW STRONG TO SEVERE STORMS SOUTH OF I-80 BUT
CONDITIONS WILL BE WEAKENING AS THE EVENING PROGRESSES.
OVERALL...HAVE LOW CONFIDENCE IN EXACTLY HOW SUNDAY NIGHT WILL PLAY
OUT DUE TO SO MANY MESOSCALE FEATURES AND WHETHER OR NOT THE
ATMOSPHERE WILL BE ABLE TO RECOVER FROM SUNDAY MORNING/S STORMS.
A SHORT WAVE MOVING WITH THE UPPER LEVEL TROUGH ROTATES THROUGH
MONDAY WITH A DECENT VORTICITY STREAMER. WENT WITH A CHANCE OF
SHOWERS AND STORMS MAINLY NORTH OF I-80 MONDAY. THINKING THE NAM IS
ONCE AGAIN TOO MOIST LEADING TO TOO MUCH CONVECTIVE DEVELOPMENT.
THINKING SHOWERS AND STORMS WILL DRIFT SOUTH OF THE IL/WI STATE LINE
MONDAY AFTERNOON AND THEN WEAKEN AS THEY CONTINUE TO SHIFT SOUTH
MONDAY EVENING. MONDAY EVENING MAY END UP BEING DRY...BUT DID NOT
HAVE ENOUGH CONFIDENCE IN A DRY FORECAST SO KEPT A SLIGHT CHANCE OF
SHOWERS AND STORMS ALONG AND SOUTH OF I-80 MONDAY EVENING.
THE UPPER LEVEL TROUGH AXIS SHIFTS EAST THROUGH WISCONSIN WITH
COOLER UPPER LEVEL AIR SINKING SOUTH THROUGH THE REGION. HIGH
PRESSURE THEN BUILDS IN FOR WEDNESDAY AND THURSDAY LEADING TO DRY
CONDITIONS THROUGH THURSDAY. HIGH TEMPS TUESDAY WILL BE AROUND
80...THEN IN THE UPPER 70S WEDNESDAY. LAKE BREEZES BOTH DAYS WILL
KEEP LOCATIONS ALONG THE LAKE IN THE MID 70S. TEMPS REBOUND INTO
THE LOW TO MID 80S THURSDAY WITH NO LAKE COOLING.
THE NEXT LOW PRESSURE SYSTEM MOVES OVER JAMES BAY THURSDAY EVENING
AND PUSHES THE HIGH PRESSURE SOUTH OVER THE OHIO VALLEY. THE LOWS
COLD FRONT SINKS SOUTH OVER FAR NORTHERN IL FRIDAY AFTERNOON SO HAVE
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND STORMS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE APPROACHING ORD AT 22Z.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE.
MM
//DISCUSSION...UPDATED 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO-CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE
SHORE AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM IN WINDS..LOW IN ORD LAKE BREEZE.
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
320 PM CDT
HIGH PRESSURE STRETCHES FROM QUEBEC THROUGH THE OHIO VALLEY WHILE
LOW PRESSURE IS OVER MANITOBA. BOTH SYSTEMS WILL SHIFT EAST WITH THE
LOW REACHING JAMES BAY BY MONDAY MORNING. AS SUCH LIGHT NORTHEAST
WINDS BECOME SOUTH TO SOUTHEAST SUNDAY. THE TROUGH ASSOCIATED WITH
THE LOWS COLD/STATIONARY FRONT SHIFTS THROUGH LATE SUNDAY NIGHT INTO
MONDAY MORNING WITH WINDS BECOMING NORTH BEHIND IT. A WEAK CLOSED
LOW FORMS OVER THE EASTERN GREAT LAKES MONDAY EVENING AND DEEPENS AS
IT SHIFTS NORTHEAST. AT THE SAME TIME HIGH PRESSURE WILL BE PUSHING
EAST OVER THE WESTERN GREAT LAKES. THIS WILL LEAD TO NORTH WINDS
INCREASING TO 10 TO 20 KT MONDAY NIGHT THROUGH TUESDAY NIGHT. WINDS
WEAKEN WEDNESDAY WITH THE HIGH OVERHEAD...AND THEN BACK TO SOUTHWEST
AS THE HIGH IS PUSHED SOUTH BY THE NEXT LOW OVER JAMES BAY THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
309 PM CDT SAT AUG 8 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 307 PM CDT SAT AUG 8 2015
REMNANTS OF AN MCS OVER EASTERN MO AT MID AFTERNOON HAS ISOLATED
LIGHT SHOWERS AND SPRINKLES OVER CENTRAL IL WEST OF I-57 AND
DRIFTING EASTWARD. MOST OF OUR AREA SHOULD STAY DRY INTO THIS
EVENING WITH JUST A FEW LIGHT SHOWERS OR SPRINKLES POSSIBLE OVER
PARTS OF CENTRAL IL WITH PARTLY TO MOSTLY CLOUDY SKIES. ANOTHER MCS
WILL LIKELY DEVELOP OVER WESTERN IA AND FAR EASTERN NEBRASKA ON NOSE
OF AN 35-45 KT 850 MB SW JET THIS EVENING AND TRACK ESE ACROSS IA
AND EVENTUALLY INTO CENTRAL IL DURING OVERNIGHT. 4KM WRF AND TAIL
END OF HRRR MODEL SHOWS MOST OF CONVECTION SREADING EAST TOWARD IL
RIVER VALLEY BETWEEN 08Z-10Z AND APPROACHING I-57 AROUND 12Z.
CONTINUED MENTION OF HEAVY RAIN FROM PEORIA NW LATE TONIGHT AFTER
09Z/4 AM WITH QPF OVERNIGHT HALF TO THREE QUARTER INCHES AND LOCALLY
1 INCH FROM GALESBURG AND MACOMB WEST. SPC HAS MARGINAL RISK OF
SEVERE STORMS OVERNIGHT WEST OF PEORIA AND SPRINGFIELD FOR GUSTY
WINDS AND SMALL HAIL WHILE SLIGHT RISK OF SEVERE IS FROM QUINCY
WESTWARD ACROSS NORTHERN MO AND SOUTHERN IA. SE IL/WABASH RIVER
VALLEY WILL LIKELY STAY DRY MOST OF TONIGHT AND PATCHY FOG COULD
FORM OVERNIGHT IN FAR SOUTHEAST IL WHERE LESS CLOUD COVER. MUGGY
LOWS TONIGHT IN THE UPPER 60S AND LOWER 70S WHICH IS CLOSE TO
CURRENT DEWPOINTS AND LIGHT WINDS TONIGHT.
&&
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 307 PM CDT SAT AUG 8 2015
A THUNDERSTORM COMPLEX/MCS IS EXPECTED TO TRACK EASTWARD ACROSS
ILLINOIS SUNDAY MORNING...LIKELY WEAKENING THROUGH THE DAYTIME.
ALTHOUGH STILL WAITING FOR THIS SYSTEM TO DEVELOP AROUND EASTERN
NB/WESTERN IA THIS EVENING...RECENT TRENDS HAVE BEEN FOR SIMILAR
SYSTEMS TO DEVELOP SLIGHTLY SOUTHWARD FROM EARLY FORECASTS...AND
LATEST MODEL RUNS HINT AT THIS AS WELL. THEREFORE...HAVE TRENDED
HEAVIER PRECIPITATION AMOUNTS A BIT SOUTHWARD FROM PREVIOUS PACKAGE
WITH AMOUNTS FROM AROUND 1 TO 1.5 INCHES POSSIBLE NORTH OF I-72 AND
WEST OF I-55 BY NOON SUNDAY...WITH THE HIGHER END OF THAT RANGE MORE
LIKELY TOWARD THE GALESBURG AREA. LOWER AMOUNTS AND LOWER
PRECIPITATION CHANCES EXPECTED WITH THIS SYSTEM SOUTH OF I-72 TOWARD
THE EFFINGHAM/I-70 AREA.
A BIT OF A BREAK IN THUNDERSTORM ACTIVITY LIKELY FOR MIDDAY SUNDAY
AS THE OVERNIGHT SYSTEM MOVES OFF TO THE EAST. EXACT TIMING...CLOUD
COVER LEFT BEHIND...AND BOUNDARIES LEFT BEHIND FROM THE OVERNIGHT
SYSTEM WILL IMPACT THE POSSIBILITY OF ANOTHER THUNDERSTORM COMPLEX
DEVELOPING SUNDAY NIGHT. CURRENT MODEL CONSENSUS FORMS THIS FARTHER
SOUTH TOWARD THE OHIO VALLEY AREA AND HAVE TRENDED PRECIP CHANCES
TOWARD THAT AREA FOR SUNDAY NIGHT INTO MONDAY.
AFTER THAT...UPPER RIDGING WILL BUILD OVER THE CENTRAL CONUS AND
DEEP TROUGHING WILL DEVELOP DOWNSTREAM ACROSS THE GREAT LAKES/OHIO
RIVER VALLEY. AS A RESULT...MUCH OF THE EXTENDED BEYOND MONDAY IS
COOL/DRY. GFS/ECMWF SHOW THE NEXT FRONTAL BOUNDARY DROPPING INTO
THE GREAT LAKES AREA JUST NORTH OF CENTRAL IL FRIDAY. HOWEVER...BOTH
LARGELY DISSIPATE THE FEATURE AND WILL MENTION JUST A SLIGHT CHANCE
POP ACROSS THE NORTHERN HALF OF THE CWA ON FRIDAY UNTIL BETTER MODEL
CONSISTENCY IS ACHIEVED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1259 PM CDT SAT AUG 8 2015
WEAKENING MCS OVER CENTRAL MO WITH SCATTERED RAIN SHOWERS AS FAR
EAST AS THE IL RIVER TO CONTINUE TO WEAKEN IS IT PUSHES EAST
ACROSS CENTRAL IL THIS AFTERNOON. HAVE VCSH THIS AFTERNOON ALONG
WITH SCATTERED CUMULUS CLOUDS AND BROKEN MID/HIGH CLOUDS.
MEANWHILE A WEAK SURFACE TROF MOVING SE TOWARD DEC AND CMI EARLY
THIS AFTERNOON COULD TRIGGER VERY ISOLATED CONVECTION THIS
AFTERNOON ALONG WITH BROKEN MVFR CEILINGS 2-3K FT. ALSO SEEING A
WIND SHIFT FROM SW DIRECTION TO WNW GENERALLY LESS THAN 10 KTS.
ANOTHER MCS EXPECTED TO DEVELOP OVER IA THIS EVENING AND SPREAD SE
INTO CENTRAL IL OVERNIGHT INTO SUNDAY MORNING. HAVE MVFR VSBYS
3-5 MILES AND CEILINGS FROM 2-4K FT POSSIBLE WITH CONVECTION AT
PIA AT 08Z...NEAR I-55 AT BMI AND SPI BY 10Z AND CMI BY 12Z.
CONVECTION MORE LIKELY ALONG I-74 LATER TONIGHT INTO SUNDAY
MORNING AND EXPECTED TO DIMINISH LATE SUNDAY MORNING OR BY MIDDAY
SUNDAY. SSE WINDS OF 5-10 KTS EXPECTED BY LATER SUNDAY MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...ONTON
AVIATION...07
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
251 PM CDT SAT AUG 8 2015
.UPDATE...1154 AM CDT
12Z RAOBS AND RECENT AMDAR SOUNDINGS SHOW A SIGNIFICANT WARM NOSE
ABOVE 850 MB...AS WELL AS PLENTY OF DRY AIR BETWEEN 850 AND 700
MB. LIGHT STRATIFORM PRECIP REMNANTS ON NORTHERN EDGE OF EARLY
MORNING MCS OVER IOWA HAS BEEN ERODING WITH EASTWARD EXTENT AS IT
ENCOUNTERS HOSTILE ENVIRONMENT FOR PRECIP. SOME SCATTERED
SPRINKLES COULD GET INTO PORTIONS OF WEST AND SOUTHWEST CWA THIS
AFTERNOON AS THERE IS SOME FORCING FROM CONVECTIVELY INDUCED
SHORTWAVE. HOWEVER WOULD NOT EXPECT ANY ORGANIZED RAIN TO SURVIVE
INTO THE CWA. THE WARM NOSE ALOFT ALSO THROWS INTO DOUBT ANY
ISOLATED CONVECTION BEING ABLE TO INITIATE IN SOUTHEAST CWA THIS
AFTERNOON IN CONVERGENT AXIS OF DISSIPATING SURFACE LOW AND LAKE
BREEZE EXPECTED TO MOVE INLAND. CONVECTIVE TEMPS IN MID 90S MAKE
IT UNLIKELY THAT CAPE IS AS HIGH AS SHOWN ON SPC MESOANALYSIS...AS
RAP INITIALIZATION HAS A HIGH BIAS WITH TEMPS. SOME CUMULUS HAS
POPPED UP...BUT NOT APPEARING TOO AGITATED UNDER CIRRUS SHIELD.
HAVE KEPT JUST SLIGHT CHANCE POPS IN SOUTHEAST 1/3 OF CWA THIS
AFTERNOON.
OTHERWISE...TEMPERATURES ARE EXHIBITING A NORTH TO
SOUTH GRADIENT...DRIVEN BY LOWER STRATUS IN NORTHERN CWA KEEPING
TEMPS IN 70S WHILE LOWER-MID 80S IN SOUTHEAST 1/2 OF CWA GIVEN
THAT FILTERED SUN STILL MAKING IT THROUGH ADVANCING CIRRUS SHIELD
AND CUMULUS DEVELOPMENT. LAKE BREEZE WILL KEEP SHORE AREAS IN 70S
THIS AFTERNOON.
RC
&&
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* LAKE BREEZE APPROACHING ORD AT 22Z.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE.
MM
//DISCUSSION...UPDATED 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO-CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE
SHORE AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM IN WINDS..LOW IN ORD LAKE BREEZE.
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 PM CDT SAT AUG 8 2015
.UPDATE...
1154 AM CDT
12Z RAOBS AND RECENT AMDAR SOUNDINGS SHOW A SIGNIFICANT WARM NOSE
ABOVE 850 MB...AS WELL AS PLENTY OF DRY AIR BETWEEN 850 AND 700
MB. LIGHT STRATIFORM PRECIP REMNANTS ON NORTHERN EDGE OF EARLY
MORNING MCS OVER IOWA HAS BEEN ERODING WITH EASTWARD EXTENT AS IT
ENCOUNTERS HOSTILE ENVIRONMENT FOR PRECIP. SOME SCATTERED
SPRINKLES COULD GET INTO PORTIONS OF WEST AND SOUTHWEST CWA THIS
AFTERNOON AS THERE IS SOME FORCING FROM CONVECTIVELY INDUCED
SHORTWAVE. HOWEVER WOULD NOT EXPECT ANY ORGANIZED RAIN TO SURVIVE
INTO THE CWA. THE WARM NOSE ALOFT ALSO THROWS INTO DOUBT ANY
ISOLATED CONVECTION BEING ABLE TO INITIATE IN SOUTHEAST CWA THIS
AFTERNOON IN CONVERGENT AXIS OF DISSIPATING SURFACE LOW AND LAKE
BREEZE EXPECTED TO MOVE INLAND. CONVECTIVE TEMPS IN MID 90S MAKE
IT UNLIKELY THAT CAPE IS AS HIGH AS SHOWN ON SPC MESOANALYSIS...AS
RAP INITIALIZATION HAS A HIGH BIAS WITH TEMPS. SOME CUMULUS HAS
POPPED UP...BUT NOT APPEARING TOO AGITATED UNDER CIRRUS SHIELD.
HAVE KEPT JUST SLIGHT CHANCE POPS IN SOUTHEAST 1/3 OF CWA THIS
AFTERNOON.
OTHERWISE...TEMPERATURES ARE EXHIBITING A NORTH TO
SOUTH GRADIENT...DRIVEN BY LOWER STRATUS IN NORTHERN CWA KEEPING
TEMPS IN 70S WHILE LOWER-MID 80S IN SOUTHEAST 1/2 OF CWA GIVEN
THAT FILTERED SUN STILL MAKING IT THROUGH ADVANCING CIRRUS SHIELD
AND CUMULUS DEVELOPMENT. LAKE BREEZE WILL KEEP SHORE AREAS IN 70S
THIS AFTERNOON.
RC
&&
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* LAKE BREEZE APPROACHING AT 20Z.
* MVFR CEILINGS IN FOG AND RAIN SUNDAY MORNING AND DAYTIME.
* ISOLATED THUNDERSTORM CHANCE.
MM
//DISCUSSION...UPDATED 18Z...
SURFACE ANALYSIS INDICATES A WEAK LOW AND ASSOCIATED
TROUGH/BOUNDARY WITHIN THE DOMINANT HIGH OVER MUCH OF THE GREAT
LAKES. THIS HAS CAUSED THE WIND FIELD TO BECOME QUITE CONVOLUTED
WITH A MESO-CYCLONE CENTERED NORTH OF CHICAGO. RADAR IMAGERY DOES
INDICATE A LAKE BREEZE PROGGED TO REACH ORD/MDW AROUND 19-20Z.
TIMING MAY NEED ADJUSTING IF THE BOUNDARY STALLS BETWEEN THE
SHORE AND ORD...BUT AT THIS PACE WINDS SHOULD BE NORTHEAST AT 20Z.
A MORE SUBSTANTIAL LOW WILL APPROACH INTO SUNDAY WITH
MOISTURE CONTENT ON THE RISE THROUGH TONIGHT. FORECAST SOUNDINGS
INDICATE A LOW LEVEL INVERSION FROM 09-13Z. SURFACE MOISTURE IS
ADEQUATE ENOUGH TO ALLOW FOR SOME FOG...FOLLOWED BY THE ARRIVAL OF
RAIN SUNDAY MORNING. RAIN/SHOWERY CONDITIONS ARE EXPECTED TO
PERSIST MUCH OF THE DAY AND THERE WILL MAY ALSO BE A PERIOD OF
THUNDER AS WELL. TIMING OF THUNDER IS UNDER QUESTION AS THE
INITIAL ARRIVAL OF THE LOW MAY SUPPORT A BRIEF UPTICK IN LAPSE
RATES...OTHERWISE WILL HAVE TO WAIT FOR ADDL SFC HEATING AFTER 20Z
SUNDAY.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM-HIGH IN WINDS AND LAKE BREEZE.
* MEDIUM IN MVFR FOG...MEDIUM HIGH IN RAIN.
* LOW IN THUNDER AND TIMING.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1154 AM CDT SAT AUG 8 2015
.UPDATE...
1154 AM CDT
12Z RAOBS AND RECENT AMDAR SOUNDINGS SHOW A SIGNIFICANT WARM NOSE
ABOVE 850 MB...AS WELL AS PLENTY OF DRY AIR BETWEEN 850 AND 700
MB. LIGHT STRATIFORM PRECIP REMNANTS ON NORTHERN EGDE OF EARLY
MORNING MCS OVER IOWA HAS BEEN ERODING WITH EASTWARD EXTENT AS IT
ENCOUNTERS HOSTILE ENVIRONMENT FOR PRECIP. SOME SCATTERED
SPRINKLES COULD GET INTO PORTIONS OF WEST AND SOUTHWEST CWA THIS
AFTERNOON AS THERE IS SOME FORCING FROM CONVECTIVELY INDUCED
SHORTWAVE. HOWEVER WOULD NOT EXPECT ANY ORGANIZED RAIN TO SURVIVE
INTO THE CWA. THE WARM NOSE ALOFT ALSO THROWS INTO DOUBT ANY
ISOLATED CONVECTION BEING ABLE TO INITIATE IN SOUTHEAST CWA THIS
AFTERNOON IN CONVERGENT AXIS OF DISSIPATING SURFACE LOW AND LAKE
BREEZE EXPECTED TO MOVE INLAND. CONVECTIVE TEMPS IN MID 90S MAKE
IT UNLIKELY THAT CAPE IS AS HIGH AS SHOWN ON SPC MESOANALYSIS...AS
RAP INITIALIZATION HAS A HIGH BIAS WITH TEMPS. SOME CUMULUS HAS
POPPED UP...BUT NOT APPEARING TOO AGITATED UNDER CIRRUS SHIELD.
HAVE KEPT JUST SLIGHT CHANCE POPS IN SOUTHEAST 1/3 OF CWA THIS
AFTERNOON.
OTHERWISE...TEMPERATURES ARE EXHIBITING A NORTH TO
SOUTH GRADIENT...DRIVEN BY LOWER STRATUS IN NORTHERN CWA KEEPING
TEMPS IN 70S WHILE LOWER-MID 80S IN SOUTHEAST 1/2 OF CWA GIVEN
THAT FILTERED SUN STILL MAKING IT THROUGH ADVANCING CIRRUS SHIELD
AND CUMULUS DEVELOPMENT. LAKE BREEZE WILL KEEP SHORE AREAS IN 70S
THIS AFTERNOON.
RC
&&
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE/NORTHEAST WINDS APPROACHING THIS AFTERNOON
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN AND ISOLATED THUNDER SUNDAY MORNING.
MM
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARLIER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON TIMING.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY
MORNING...MEDIUM LOW WITH TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON TIMING...LOW WITH
THUNDER CHANCES.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1107 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* LAKE BREEZE/NORTHEAST WINDS APPROACHING THIS AFTERNOON
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN AND ISOLATED THUNDER SUNDAY MORNING.
MM
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARLIER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON TIMING.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY
MORNING...MEDIUM LOW WITH TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON TIMING...LOW WITH
THUNDER CHANCES.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
902 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WEST/NORTHWEST WINDS BECOMING NORTHEAST THIS AFTERNOON.
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN SUNDAY MORNING...WITH POSSIBLE THUNDER.
RODRIGUEZ/MM
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARLIER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY
MORNING...MEDIUM LOW WITH EXACT TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON EXACT TIMING...LOW
WITH THUNDER CHANCES.
RODRIGUEZ/MM
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
650 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
* MVFR CIGS/VIS POSSIBLE LATE TONIGHT INTO SUNDAY MORNING.
* RAIN SUNDAY MORNING...WITH POSSIBLE THUNDER.
RODRIGUEZ
//DISCUSSION...UPDATED 12Z...
VFR AND DRY CONDITIONS IN PLACE THIS MORNING AS WEAK SURFACE LOW
CONTINUES TO WEAKEN. SOME LOWER STRATUS HAD BRIEFLY DEVELOPED
EARILER THIS MORNING BUT HAS ALREADY BEGUN TO ERODE AND WILL
CONTINUE TO DO SO THIS MORNING. HAVE MAINTAINED DRY CONDITIONS
THROUGH THIS AFTERNOON...BUT WITH AN ISOLATED SPRINKLE STILL
BRIEFLY POSSIBLE. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON. HIGHER CHANCES FOR PRECIP...REDUCED VIS AND LOWER
CEILINGS WILL ARRIVE LATE TONIGHT INTO EARLY SUNDAY MORNING WITH
THE APPROACH OF ANOTHER SYSTEM. SOME TIMING DIFFERENCES WITH THE
ONSET OF PRECIP WITH THE EXACT TIMING IN THE TAF LIKELY BEING
CHANGED BUT WITH ITS ARRIVAL...IT WILL LIKELY PERSIST THROUGH THE
REMAINING FORECAST PERIOD. HAVE LEFT OUT ANY MENTION OF THUNDER AT
THIS TIME WITH THE HIGHEST INSTABILITY TO THE SOUTH OF THE
TERMINALS...BUT WILL NEED TO MONITOR FOR POSSIBLE BETTER
DEVELOPMENT WHICH COULD LEAD TO AT LEAST ISOLATED THUNDER DURING
THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
* HIGH WITH MVFR CIGS/VIS LATE TONIGHT INTO SUNDAY MORNING...LOW
MEDIUM WITH EXACT TIMING.
* HIGH WITH RAIN SUNDAY MORNING...MEDIUM ON EXACT TIMING...LOW
WITH POSSIBLE THUNDER.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...CHANCE OF THUNDERSTORMS.
MONDAY...CHANCE OF THUNDERSTORMS.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...SLIGHT CHANCE OF SHOWERS LATE.
FRIDAY...VFR.
RODRIGUEZ
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
404 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* MVFR CIGS/VIS POSSIBLE THIS MORNING.
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WEAKENING SURFACE LOW CONTINUES TO PUSH THROUGH THE REGION EARLY
THIS MORNING WITH RADAR IMAGERY DEPICTING LIGHT ISOLATED SHOWERY
ACTIVITY EAST/NORTHEAST OF THE TERMINALS. ANY FURTHER PRECIP
DEVELOPMENT WILL REMAIN TO THE EAST OF ALL THE TERMINALS...WITH
DRY CONDITIONS EXPECTED THIS MORNING THROUGH MUCH OF THE DAY.
SHORT TERM GUIDANCE HINTING AT SOME TYPE OF LIGHT PRECIP LATER
THIS AFTERNOON...BUT THINK THIS MAY BE A BIT AGRESSIVE AS FAIRLY
DRY LOW LEVELS WILL REMAIN IN PLACE. IF ANYTHING WERE TO PUSH
ACROSS THE TERMINALS LATER THIS AFTERNOON IT WOULD LIKELY ONLY BE
AN ISOLATED SPRINKLE. VFR CEILINGS EXPECTED THIS MORNING AND
THROUGH THE FORECAST PERIOD...WITH AREAS OF FOG STILL POSSIBLE
EARLY THIS MORNING. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM IN MVFR CIGS/VIS THIS MORNING.
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA/MVFR. SOUTH-SOUTHEAST WINDS.
MONDAY...SLGT CHANCE OF AFTN SHRA/TSRA. OTHERWISE VFR. NORTH-
NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. WEST WINDS.
RATZER
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
345 AM CDT
SUNDAY NIGHT THROUGH FRIDAY...
THE SURFACE LOW SLIDES BY TO THE SOUTH SUNDAY NIGHT...BUT LOOKS
LIKE THERE COULD BE SOME LINGERING RAIN/SHOWERS ON THE BACK
SIDE...THOUGH THE TREND SHOULD BE DOWNWARD. UPPER LEVEL FLOW
BECOMES MORE AMPLIFIED MONDAY. WITH NORTHWEST FLOW ALOFT...ANOTHER
DISTURBANCE WILL PASS OVER THE AREA AHEAD OF A SOUTHWARD MOVING
COLD FRONT. THIS WILL BRING ANOTHER CHANCE OF SHOWERS AND STORMS
MONDAY BEFORE COOLER HIGH PRESSURE BUILDS IN FOR DRY CONDITIONS
THROUGH AT LEAST MID WEEK. STORM CHANCES RETURN FOR THE LATTER
HALF OF THE WEEK IN VERY AMPLIFIED NORTHWEST FLOW ALOFT.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR VIS POSSIBLE THIS MORNING.
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WEAKENING SURFACE LOW CONTINUES TO PUSH THROUGH THE REGION EARLY
THIS MORNING WITH RADAR IMAGERY DEPICTING LIGHT ISOLATED SHOWERY
ACTIVITY EAST/NORTHEAST OF THE TERMINALS. ANY FURTHER PRECIP
DEVELOPMENT WILL REMAIN TO THE EAST OF ALL THE TERMINALS...WITH
DRY CONDITIONS EXPECTED THIS MORNING THROUGH MUCH OF THE DAY.
SHORT TERM GUIDANCE HINTING AT SOME TYPE OF LIGHT PRECIP LATER
THIS AFTERNOON...BUT THINK THIS MAY BE A BIT AGRESSIVE AS FAIRLY
DRY LOW LEVELS WILL REMAIN IN PLACE. IF ANYTHING WERE TO PUSH
ACROSS THE TERMINALS LATER THIS AFTERNOON IT WOULD LIKELY ONLY BE
AN ISOLATED SPRINKLE. VFR CEILINGS EXPECTED THIS MORNING AND
THROUGH THE FORECAST PERIOD...WITH AREAS OF FOG STILL POSSIBLE
EARLY THIS MORNING. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN MVFR VIS THIS MORNING.
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA/MVFR. SOUTH-SOUTHEAST WINDS.
MONDAY...SLGT CHANCE OF AFTN SHRA/TSRA. OTHERWISE VFR. NORTH-
NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. WEST WINDS.
RATZER
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
332 AM CDT SAT AUG 8 2015
.SHORT TERM...
326 AM CDT
THROUGH SUNDAY...
AN ACTIVE PATTERN WILL BE IN PLACE FOR A FEW DAYS BEFORE THINGS
QUIET DOWN NEXT WEEK. SOMEWHAT MESSY SURFACE PATTERN IN PLACE WITH
A WEAK SURFACE LOW/TROUGH AXIS PROGGED TO SINK SOUTHEASTWARD SLOWLY
TODAY...THOUGH IT WILL LOSE SOME DEFINITION TODAY...ALLOWING WEAK
HIGH PRESSURE TO CONTROL THE LOWER LEVELS. ALOFT...HIGH PRESSURE
REMAINS ANCHORED OVER THE SOUTHERN STATES...A STRONG CLOSED LOW IN
THE CANADIAN PRAIRIES...AND LOW PRESSURE MOVING INTO THE GREAT BASIN.
COMPLEX OF THUNDERSTORMS MARCHING EASTWARD ACROSS KS/NE/IA IS ALREADY
SHOWING SOME WEAKENING SIGNS IN THE IR IMAGERY...ESPECIALLY ON
ITS NORTHERN AND EASTERN EDGES...AS THE LOW LEVEL JET FEEDING THIS
MCS WILL REMAIN FOCUSED IN THE PLAINS. THERE IS AN UPPER LEVEL
SHORTWAVE/MODEST SPEED MAX AHEAD OF THE GREAT BASIN LOW THAT WILL
CONTINUE EASTWARD AROUND THE NORTHERN PERIPHERY OF THE SOUTHERN
UNITED STATES HIGH PRESSURE RIDGE IN THE STRONGER WESTERLY FLOW
ACROSS THE MIDWEST. THIS WAVE IS THE COMPLICATING FACTOR IN THE
FORECAST FOR THIS AFTERNOON. NAM/GFS/ECMWF/SREF ALL CONTINUE TO
SIGNIFICANTLY WEAKEN THE MCS AS IT ENTERS INTO ILLINOIS...AND
ESPECIALLY NORTHEAST ILLINOIS. SHORT-TERM GUIDANCE INCLUDING THE
RAP/HRRR/EXPERIMENTAL HRRR PAINT A SLIGHTLY SIMILAR PICTURE...BUT
SHOW SOME OF THE PRECIPITATION SURVIVING THROUGH THE AREA.
SOUNDINGS IN NE IL/NW IN ARE QUITE DRY IN THE LOW LEVELS..AND THIS
REMAINS THE CASE THROUGH THE DAY AS WELL. AT THIS POINT OUR
FEELING IS THAT THIS WILL ARRIVE IN THE FORM OF SPRINKLES OR
POSSIBLY SOME VERY LIGHT RAIN. HAVE GONE WITH SPRINKLES FOR
NOW...THOUGH THIS WILL BEAR WATCHING AS THIS COMPLEX CONTINUES
EASTWARD AND MAY INTRODUCE POPS BEFORE THIS SHIFT ENDS IF THIS
TREND CONTINUES. CLOUD COVER WILL THICKEN QUICKLY TODAY
REGARDLESS...AND THIS COULD PREVENT SOME LOCATIONS FROM GETTING
INTO THE 80S TODAY WITH SOME INCREASE IN HUMIDITY. THERE COULD BE
SOME ADDITIONAL SHOWERS OR STORMS AHEAD OF THE SOUTHEASTWARD
SINKING SURFACE TROUGH OUT AHEAD OF MAIN STORM SYSTEM THIS
AFTERNOON WHERE A MENTION EXISTS THIS AFTERNOON/EARLY EVENING.
ADDITIONAL SHORTWAVE NOTED BY 500 MB SPEED MAX AGAIN AROUND 50
KT WILL MOVE AROUND THE PERIPHERY ALONG A SIMILAR PATH...WITH THE
NEXT ONE SLATED FOR SUNDAY MORNING. THE DIFFERENCE WITH THIS WAVE
IS THE LOW LEVEL JET/MOISTURE TRANSPORT WILL BE FOCUSED CLOSER TO
OUR REGION. LAPSE RATES AT THIS POINT DO NOT LOOK IMPRESSIVE AT
THIS POINT IN TIME. THE MAIN FOCUS TIME WILL BE LATE TONIGHT INTO
EARLY SUNDAY. THE LLJ/MOISTURE CONVERGENCE PEAKS IN OUR SOUTHERN
ZONES WHERE HIGHER CONFIDENCE IN HEAVIER PRECIPITATION RATES
EXIST GIVEN PWATS AROUND 2". MOST AREAS...EXCEPT POSSIBLY THE FAR
NORTH AND EAST...LOOK TO SEE PRECIP WITH THIS ROUND.
DESTABILIZATION LATER IN THE DAY LIKELY WILL BE INHIBITED BY
EXTENSIVE CLOUD COVER FROM MORNING ACTIVITY ALSO. SPC STILL
HIGHLIGHTS SOUTHERN AND EASTERN PORTIONS OF THE AREA IN A MARGINAL
RISK FOR SEVERE WEATHER...THOUGH STILL MANY QUESTION MARKS ON THE
EVOLUTION. THE HIGHER RISK LOOKS TO BE JUST SOUTH OF THE AREA AS
MODELS KEEP THE SURFACE LOW SOUTH AND LEAVE OUR AREA IN THE COLD
SECTOR. WITH THE FLOW TURNING NORTHWESTERLY AND ADDITIONAL
DISTURBANCES MOVING THROUGH...WILL STILL NEED TO KEEP AN EYE ON IF
ANY CLEARING OCCURS OR IF THE WARM SECTOR INCHES A BIT FARTHER
NORTH. AT THIS POINT...MOST AREAS HANG ONTO CLOUDY CONDITIONS WITH
HIGHS NOT GETTING OUT OF THE 70S.
KMD
&&
.LONG TERM...
259 PM CDT
LATEST MORNING DISCUSSION FORTHCOMING...PREVIOUS DISCUSSION
BELOW...
SATURDAY NIGHT THROUGH FRIDAY...
THE BEST CHANCE FOR PRECIP AND STORMS WILL BE LATE SATURDAY NIGHT
INTO SUNDAY MORNING WITH AN ADDITIONAL SLIGHT CHANCE TO CHANCE OF
PRECIP THROUGH MONDAY AFTERNOON. AS THE UPPER LEVEL LOW SHIFTS EAST
OVER QUEBEC EARLY NEXT WEEK...WE WILL GET UNDER A RIDGING PATTERN
AND A SURFACE HIGH PRESSURE SYSTEM. THIS WILL LEAD TO DRY CONDITIONS
THROUGH MOST OF NEXT WEEK.
FOR SATURDAY NIGHT AND SUNDAY...
EXPECTING A LINGERING MCV TO SUPPORT STORM DEVELOPMENT OVER IOWA
SATURDAY AFTERNOON AND EVENING WITH THE AREA OF STORMS SHIFTING EAST
ACROSS NORTHERN IL AND NW INDIANA EARLY SUNDAY MORNING. HAVE THE
GREATEST CONFIDENCE IN WIDESPREAD RAIN ALONG AND SOUTH OF I-88. NOT
OVERLY EXCITED ABOUT SVR POTENTIAL AS THE STORM COMPLEX MOVES INTO
THE REGION. THE GFS KEEPS THE LLJ NOSE OVER WEST CENTRAL IL WHILE
THE NAM BRINGS IT INTO CENTRAL IL. THE NAM IS TYPICALLY A BIT TOO
AMBITIOUS WITH CAPE VALUES AS WELL SO LEANING TOWARD THE GFS
SOLUTION OF A DECAYING MCS. HOWEVER...IF THE NAM IS CORRECT...THE
MCS COULD PRODUCE SOME STRONG WINDS. EITHER WAY MOST IF NOT ALL OF
THE CWA SHOULD SEE NEEDED ACCUMULATING RAINFALL FROM THE DECAYING
SYSTEM OF STORMS.
KEPT A CHANCE OF AFTERNOON AND EVENING PRECIP AS I AM NOT OVERLY
CONFIDENT THAT WE WILL DESTABILIZE ENOUGH TO SEE A SECOND ROUND OF
STORMS SUNDAY. HAVE LOW CONFIDENCE IN WHEN AND WHERE ADDITIONAL
SHOWERS AND STORMS WILL FORM SUNDAY AFTERNOON AND EVENING.
DEVELOPMENT DEPENDS ON WHERE THE MCV STALLS AND HOW QUICKLY WE
RECOVER FROM THE MORNING/S CONVECTION. GUIDANCE FEATURES NEW
DEVELOPMENT ROUGHLY ALONG AND EAST OF THE I-55 CORRIDOR...BUT ONCE
AGAIN HAVE LOW CONFIDENCE IN TIMING...EXACT LOCATION...AND COVERAGE
OF ANY ADDITIONAL STORMS. IF AFTERNOON STORMS DO DEVELOP...STRAYED
FROM THE OVERLY AMBITIOUS NAM WHICH SEEMS TO HAVE MUCH TOO HIGH CAPE
AND SHEAR VALUES.
KEPT HIGH TEMPS SUNDAY IN THE LOW 80S AND HIGH TEMPS COULD BE EVEN
LOWER IF THE CLOUD SHIELD FROM THE MORNING/S CONVECTION LINGERS
THROUGHOUT THE DAY.
MONDAY THROUGH FRIDAY...
THE UPPER LEVEL TROUGH/S SECONDARY TROUGH AXIS SWINGS THROUGH MONDAY
MORNING WITH SURFACE HIGH PRESSURE BUILDING IN BEHIND IT. HAVE A
SLIGHT CHANCE TO LOW END CHANCE OF SHOWERS AND STORMS OCCURRING AS
THE TROUGH AXIS AND UPPER LEVEL VORT STREAMER SLIDE THROUGH MONDAY
AFTERNOON. NOT EXPECTING WIDESPREAD DEVELOPMENT MONDAY AFTERNOON.
DRY CONDITIONS ARE THEN FORECAST THROUGH THURSDAY AS WE ARE UNDER
THE INFLUENCE OF A SURFACE HIGH. LAKE BREEZES ARE POSSIBLE MONDAY
THROUGH WEDNESDAY LEADING TO LAKE SIDE COOLING. AWAY FROM THE LAKE
EXPECTING HIGH TEMPS AROUND 80. THE HIGH THEN DRIFTS EAST LATE IN
THE WEEK WITH ANOTHER LOW PRESSURE SYSTEM IMPACTING THE MID WEST
THURSDAY NIGHT INTO FRIDAY. GUIDANCE DIFFERS IN THE EXACT PATH OF
THIS LOW SO KEPT PRECIP CHANCES IN THE CHANCE OR LOWER RANGE.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MVFR VIS POSSIBLE THIS MORNING.
* WESTERLY WINDS BECOMING NORTHEAST THIS AFTERNOON.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
WEAKENING SURFACE LOW CONTINUES TO PUSH THROUGH THE REGION EARLY
THIS MORNING WITH RADAR IMAGERY DEPICTING LIGHT ISOLATED SHOWERY
ACTIVITY EAST/NORTHEAST OF THE TERMINALS. ANY FURTHER PRECIP
DEVELOPMENT WILL REMAIN TO THE EAST OF ALL THE TERMINALS...WITH
DRY CONDITIONS EXPECTED THIS MORNING THROUGH MUCH OF THE DAY.
SHORT TERM GUIDANCE HINTING AT SOME TYPE OF LIGHT PRECIP LATER
THIS AFTERNOON...BUT THINK THIS MAY BE A BIT AGRESSIVE AS FAIRLY
DRY LOW LEVELS WILL REMAIN IN PLACE. IF ANYTHING WERE TO PUSH
ACROSS THE TERMINALS LATER THIS AFTERNOON IT WOULD LIKELY ONLY BE
AN ISOLATED SPRINKLE. VFR CEILINGS EXPECTED THIS MORNING AND
THROUGH THE FORECAST PERIOD...WITH AREAS OF FOG STILL POSSIBLE
EARLY THIS MORNING. SOUTH SOUTHWEST WINDS WILL TURN MORE WEST AND
NORTHWEST THROUGH THIS MORNING BEFORE WEAKENING FLOW ALLOWS
DEVELOPING LAKE BREEZE TO PUSH ACROSS THE TERMINALS THIS
AFTERNOON.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM IN MVFR VIS THIS MORNING.
* HIGH WITH WIND SPEED/DIRECTION AND WIND SHIFT...MEDIUM ON EXACT
TIMING...LOW MEDIUM ON SPEEDS BELOW 10KT.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...CHANCE OF TSRA/MVFR. SOUTH-SOUTHEAST WINDS.
MONDAY...SLGT CHANCE OF AFTN SHRA/TSRA. OTHERWISE VFR. NORTH-
NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. WEST WINDS.
RATZER
&&
.MARINE...
307 AM CDT
DESPITE LOW PRESSURE NEAR THE SOUTHERN END OF THE LAKE WEAKENING
THIS MORNING...HIGH PRESSURE TO THE EAST/NORTHEAST IS ALLOWING FOR
A FAIRLY TIGHT SURFACE GRADIENT ACROSS MUCH OF THE LAKE. EAST
SOUTHEAST WINDS OF 15 TO 25 KT WITH OCCASIONAL GUSTS TO 30 KT
CONTINUE EARLY THIS MORNING OVER MUCH OF THE OPEN WATERS BUT AS
THIS LOW SLOWLY MOVES EAST...STRONGEST WINDS WILL BECOME MORE
FOCUSED ACROSS THE NORTH HALF THROUGH MID TO LATE MORNING BEFORE
OBSERVING A DIMINISHING TREND INTO THE AFTERNOON. IT IS BECOMING
MORE LIKELY FOR A FURTHER SOUTHWARD TREND WITH THE NEXT LOW
PRESSURE SYSTEM ON SUNDAY AND ALTHOUGH DIRECTIONS WILL LIKELY
VARY...SPEEDS ARE NOT EXPECTED TO BE AS HIGH AS PREVIOUSLY
THOUGHT. BY MONDAY...THIS LOW WILL BE EAST OF THE LAKE WITH
NORTHERLY WINDS EXPECTED TO PREVAIL THROUGH MID WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
136 AM EDT SAT AUG 8 2015
.SYNOPSIS...
ISSUED AT 814 PM EDT FRI AUG 7 2015
AN UPPER LEVEL DISTURBANCE TRACKING ACROSS THE GREAT LAKES TONIGHT
MAY BRING AN ISOLATED SHOWER TO PARTS OF EXTREME NORTHWEST
INDIANA AND SOUTHWEST LOWER MICHIGAN. LOW TEMPERATURES TONIGHT
WILL RANGE FROM THE UPPER 50S TO LOWER 60S. HIGH TEMPERATURES ON
SATURDAY WILL REACH BACK TO AROUND THE 80 DEGREE MARK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
A COMPACT UPPER LEVEL SHORT WAVE WILL CONTINUE EASTWARD ACROSS
THE WESTERN GREAT LAKES THIS EVENING...ALTHOUGH LATEST SHORT TERM
TRENDS SEEM TO SUGGEST THIS SHORT WAVE IS BECOMING INCREASINGLY
SHEARED. A LARGE AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS
IS ACCOMPANYING THIS VORT. SHORT TERM RAP TRENDS SUGGEST THIS WAVE
WILL BECOMING INCREASINGLY SHEARED WITH A MORE NARROWED CHANNEL OF
DPVA WORKING FROM WEST TO EAST ACROSS THE LOCAL AREA IN THE 22Z-
04Z TIMEFRAME. LOW LEVEL THETAE TROUGH CURRENTLY RESIDING ACROSS
THE AREA IS PROVIDING A FAIRLY SHARP WEST-EAST INSTABILITY
GRADIENT FROM THE MID MS VALLEY TO THE OHIO VALLEY...AND WOULD
EXPECT SOME DIMINISHING TREND IN COVERAGE AS THIS WAVE LOSES SOME
POTENCY AND DUE TO EFFECTS OF INITIALLY DRY AIR MASS ACROSS THE
REGION. HAVE MAINTAINED SOME SLIGHT CHANCE POPS PARTICULARLY
ACROSS THE FAR NORTHWEST/NORTH THIS EVENING FOLLOWING THIS
FORCING...WITH MORE QUESTIONABLE MOISTURE RETURN ACROSS REMAINDER
OF THE AREA ARGUING FOR MAINTENANCE OF DRY FORECAST.
FORCING WITH THIS WAVE WILL WANE LATE EVENING...BUT LAGGING LOW
LEVEL THETAE RIDGE MAY BEGIN TO HAVE SOME INFLUENCE OVERNIGHT INTO
EARLY SATURDAY MORNING. HAVE OPTED TO KEEP SOME SLIGHT CHANCE POPS
GOING OVERNIGHT INTO EARLY SATURDAY MORNING ACROSS THE
NORTH/NORTHWEST DUE TO LINGERING ADVECTIVE FORCING AND APPROACH OF A
VERY WEAK REMNANT SFC TROUGH. SOME EASTWARD PROGRESSION OF DAMPENED
LOW LEVEL THERMAL RIDGING ON SATURDAY SHOULD SOMEWHAT OFFSET
EXPECTED MORE CLOUD COVER ON SATURDAY FOR HIGHS ONCE AGAIN AROUND
80...OR POSSIBLY INTO THE LOWER 80S DEPENDING ON EXTENT OF CLOUD
COVER.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 410 PM EDT FRI AUG 7 2015
AN UPPER LEVEL SYSTEM OVER THE WESTERN CONUS WILL EJECT AN
UPPER LEVEL TROF OVER THE LARGE UPPER LEVEL SOUTHERN PLAINS RIDGE
AND THEN THE TROF WILL MOVE INTO THE UPPER GREAT LAKES REGION BY
EARLY SUNDAY. NCEP MODELS...THE CANADIAN GEM AND THE ECMWF WERE
SHOWING LARGE DIFFERENCES IN HANDLING THIS SYSTEM. FAVOR A
SOUTHERN TRACK WHICH IS SUPPORTED THE BY ECMWF AND THE CPS
ANALOGS. ALSO...MOST MODELS TRACKED THE SYSTEM EARLIER THIS WEEK
TOO FAR NORTH. SO FOR THIS PACKAGE...KEPT A CHANCE FOR STORMS
SUNDAY. HOWEVER...INCREASED STORM CHANCES A LITTLE OVER SOUTHWEST
AREAS IN DEFERENCE TO THE ECMWF. IF THE SOUTHERN TRACK
VERIFIES...CHANCES FOR SEVERE STORMS SHOULD BE LIMITED MORE TO THE
SOUTH AND SOUTHWEST. OTHERWISE...SOME LINGERING SHOWERS AND STORMS
ARE POSSIBLE MONDAY AND THEN CONDITIONS SHOULD BE DRY WITH
TEMPERATURES A LITTLE BELOW NORMAL AS A LARGE UPPER LEVEL TROF
REMAINS OVER THE AREA NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 136 AM EDT SAT AUG 8 2015
PRIMARILY VFR CONDITIONS EXPECTED THIS PERIOD. SUBTLE LOW LEVEL
THETA-E RIDGE AND WEAK MIDLEVEL SHORTWAVE MAY TOUCH OFF A FEW
ISOLATED SHOWERS THIS AFTERNOON BUT CHANCES TOO LOW FOR INCLUSION
IN THE TAF AND IMPACTS MINIMAL ANYWAY. DESPITE SLIGHTLY INCREASED
MOISTURE...CEILINGS EXPECTED TO REMAIN ABOVE 3 KFT. WINDS WILL
SLOWLY VEER TO A MORE WESTERLY DIRECTION BY THIS
AFTERNOON...BECOMING LIGHT AND VARIABLE BY THE END OF THE PERIOD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...T
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS TOPEKA KS
644 PM CDT SUN AUG 9 2015
...UPDATE TO SHORT TERM CONVECTIVE FORECAST AND AVIATION FORECAST
DISCUSSION...
.UPDATE...
ISSUED AT 629 PM CDT SUN AUG 9 2015
THE NEXT 12 HOURS OF THE FORECAST REMAIN QUITE UNCERTAIN IN TERMS
OF DETAILS. OVER THE NEXT FEW HOURS, EXPECT ELEVATED SHOWERS TO
CONTINUE WITHOUT MUCH CHANCE OF INTENSIFICATION. AT THE SAME TIME,
THE ATMOSPHERE OVER NORTHEAST KANSAS IS VERY UNSTABLE AND ONLY
WEAKLY CAPPED (PER 00Z TOP SOUNDING) SO IF THE LIFT PRODUCING
THESE SHOWERS CAN MANAGE TO LIFT SURFACE BASED PARCELS AN ISOLATED
STRONG STORM WOULD BECOME QUICKLY POSSIBLE. WILL ALSO BE CLOSELY
WATCHING THE THUNDERSTORM CLUSTER IN NORTHERN NEBRASKA AS IT HAS
NOW BEGUN MORE OF A SOUTHWARD PROPAGATION COMPONENT. THIS CLUSTER
SEEMS LIKELY TO WORK ITS WAY SOUTHEAST THROUGH THE EVENING, AND
EVEN IF IT SHOULD WEAKEN BEFORE ARRIVAL OR PASS EAST OF THE
FORECAST AREA, THERE WOULD LIKELY BE AN OUTFLOW BOUNDARY PUSHING
THROUGH THE AREA WHICH MAY ACT AS A FOCUS FOR LOCALIZED CONVECTIVE
DEVELOPMENT OVERNIGHT. FINALLY, ALSO CONTINUE TO WATCH THE AREA OF
LIFT MOVING OUT OF FAR WESTERN OKLAHOMA AND SOUTHWEST KANSAS AS
THE RAP/HRRR IN PARTICULAR ALONG WITH SOME LARGER SCALE MODELS ARE
CONSISTENT IN DEVELOPING AN MCS IN THESE AREAS WHICH COULD IMPACT
AT LEAST SOUTHERN PARTS OF THE FORECAST AREA. THROUGH ALL OF THESE
UNCERTAINTIES REGARDING FORCING MECHANISMS, THE OVERNIGHT AIRMASS
IS LIKELY TO REMAIN QUITE UNSTABLE, WITH FORECAST SOUNDINGS
INDICATING AMPLE CAPE ROOTED AS LOW AS 2000 FEET AGL...AND SHOULD
STORMS DEVELOP THEY WILL MAINTAIN THE CAPABILITY TO PRODUCE STRONG
TO SEVERE STORMS WITH DAMAGING WIND THE MAIN HAZARD AND SOME
POTENTIAL FOR LARGE HAIL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
CURRENT SURFACE ANALYSIS SHOWS THE MAIN SYNOPTIC BOUNDARY EXTENDING
SOUTHWARD FROM KANSAS CITY TO WICHITA, WHICH IS FORECAST TO SAG
SOUTHWARD THROUGH THE AFTERNOON AND EVENING HOURS. ALTHOUGH THE MORE
EVIDENT THERMAL GRADIENT HAS PUSHED INTO SOUTHEAST KS AND HAS BEEN
RESPONSIBLE FOR SCATTERED SHOWERS AND ISOLATED THUNDER THIS MORNING.
THIS HAS KEPT THE CLOUD COVER AROUND MUCH LONGER THAN FORECASTED,
BUT AN AREA OF CLEAR SKIES IS WORKING EASTWARD ACROSS NORTHEAST KS,
WHICH MAY ALLOW TEMPERATURES TO WARM INTO THE LOWER TO MIDDLE 90S.
HIGH MOISTURE POOLING IN THE BOUNDARY LAYER HAS KEPT DEW POINTS IN
THE MID TO UPPER 70S. EXPECT THAT HEAT INDICES WILL BE IN THE LOWER
100S THROUGH EARLY EVENING FOR LOCATIONS ALONG AND SOUTH OF I-70.
THERE WILL BE A FEW THINGS OF CONCERN LATER THIS EVENING AND
OVERNIGHT. THE MODELS SHOW A SHORTWAVE TROUGH ON THE NORTHERN
PERIPHERY OF THE UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS WILL
TRACK ACROSS SOUTHERN KS TONIGHT. THIS MAY SUPPORT THE DEVELOPMENT
OF AN MCS OR MULTICELL CLUSTER IN WESTERN OR CENTRAL KS THIS EVENING
NORTH OF THE SURFACE BOUNDARY. SURFACE BASED CONVECTION HAS ALREADY
BEGAN IN NORTHWEST KS. AS THAT BOUNDARY DRIFTS SOUTHWARD THE TRACK
OF THE MCS MAY ALSO DO THE SAME AS DEPICTED BY THE NAM. THE PAST FEW
RUNS OF THE HRRR HAVE BEEN CLIPPING THE SOUTHERN FORECAST AREA WITH
THIS MCS. INSTABILITY HAS BEEN SOMEWHAT LIMITED TODAY ACROSS
SOUTHERN KS AS OPPOSED TO NORTHERN KS, WHICH HAS SET UP A DECENT
GRADIENT. THEREFORE IT IS UNCERTAIN HOW SEVERE THESE STORMS WILL BE
THIS EVENING, BUT THE TRACK MAY BE MORE FOCUSED ALONG THIS
INSTABILITY GRADIENT INSTEAD. AS FOR NOW THE BEST CHANCES FOR PRECIP
WILL BE SOUTH OF I-70 LATE THIS EVENING AND EARLY MORNING WITH THE
SLIGHT CHANCE FOR A STRONG STORM. WITH PLENTY OF MOISTURE AROUND AND
LIGHT LOW LEVEL WINDS ASSOCIATED WITH THE BOUNDARY THERE IS A CHANCE
FOR HAZE AND OR FOG EARLY TOMORROW MORNING. THERE ARE SOME
INDICATIONS THAT THE SKIES COULD CLEAR LATE TONIGHT AND ALLOW FOR
BOUNDARY LAYER COOLING. A FEW OF THE MODELS ARE HINTING AT A
NORTHERN SHORTWAVE THAT WILL TRACK OVER SD AND NE OVERNIGHT. THIS
MAY ALSO SUPPORT A SOUTHEASTWARD MOVING MCS THAT COULD REACH
NORTHERN KS AROUND SUNRISE. IN FACT, THE INSTABILITY IS ALREADY
DECENT IN THAT AREA, WHICH WOULD SUPPORT THIS SCENARIO BETTER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
THERE IS NOT MUCH CHANGE IN THE FORECAST FOR MONDAY NIGHT THROUGH
SUNDAY AS MODELS CONTINUE TO SHOW AN UPPER LEVEL RIDGE AMPLIFYING
TO THE WEST AND SOUTHWEST CAUSING NORTHWEST FLOW TO SET UP OVER
THE FORECAST AREA. ABOUT THE ONLY THING OF CONCERN IS THE
POSSIBILITY FOR SOME ELEVATED PRECIP ACROSS NORTH CENTRAL KS LATE
TUESDAY NIGHT AND WEDNESDAY MORNING. THERE ARE INDICATIONS THAT
CONVECTION IN THE MOUNTAINS COULD GENERATE A VORT MAX AND THEN
DRIFT EAST AND SOUTH THROUGH CENTRAL KS. FOR NOW MOST GUIDANCE
KEEPS ANY PRECIP JUST TO THE WEST OF THE FORECAST AREA. THIS SEEMS
TO MAKE SINCE AS MODELS BRING THE CENTER OF THE 850 MB RIDGE OVER
THE FORECAST AREA BY 12Z WED WITH NO REAL RETURN FLOW AND THE
DEEPER MOISTURE AXIS REMAINING OVER WESTERN KS. SO THE FORECAST
REMAINS DRY THROUGH NEXT WEEKEND WITH NO OBVIOUS SIGNS OF FORCING
IMPACTING THE FORECAST AREA AFTER WEDNESDAY.
TEMPS ARE EXPECTED TO BE COOLER THAN NORMAL FOR TUESDAY THROUGH
THURSDAY. MODELS ARE IN AGREEMENT THAT A MODIFIED HIGH PRESSURE
SYSTEM WILL BUILD INTO THE AREA WITH SOME WEAK COLD AIR ADVECTION
AND DRYER AIR. BECAUSE OF THIS LOWS SHOULD BE IN THE LOWER AND MID
60S WITH HIGHS IN THE 80S. BY FRIDAY AND INTO THE WEEKEND, THE
UPPER RIDGE IS EXPECTED TO PROPAGATE EAST INTO THE PLAINS AS AN
UPPER TROUGH OVER THE PACIFIC NORTHWEST COAST MOVES INLAND. THIS
SHOULD SHIFT THE THERMAL RIDGE OUT INTO THE PLAINS WITH HIGHS
WARMING BACK INTO THE LOWER AND MID 90S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 629 PM CDT SUN AUG 9 2015
THIS TAF HAS ABOVE NORMAL UNCERTAINTY ESPECIALLY BEYOND 05Z. VFR
CONDITIONS WITH SCATTERED SHOWERS ARE LIKELY THIS EVENING. AFTER
04-06Z, THERE IS POTENTIAL FOR MORE ORGANIZED STORMS TO MOVE
OVER/NEAR TAF SITES, BUT STORMS COULD JUST AS EASILY REMAIN BOTH
NORTH AND SOUTH OF SITES. FOR NOW HAVE HIGHLIGHTED BEST POTENTIAL
TIMING WITH A VCTS. IT THEN APPEARS THAT SEVERAL HOURS OF MVFR
CIGS ARE LIKELY AFTER SUNRISE THROUGH THE MORNING, ALTHOUGH THERE
IS POTENTIAL FOR THESE CIGS TO BE IN THE IFR RANGE ESPECIALLY
BETWEEN 12-14Z...OR COULD REMAIN SCATTERED WITH NO CEILING.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...SANDERS
LONG TERM...WOLTERS
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
527 PM MDT SUN AUG 9 2015
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 132 PM MDT SUN AUG 9 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE CONTINUING
TO DOMINATE PATTERN ACROSS SOUTHERN P.LAINS WITH WESTERLY FLOW
ACROSS THE NORTHERN PLAINS. H7 SHORTWAVE TROUGH HAS WEAKENED AND
SHIFTED EAST...WITH ANOTHER H7 SHORTWAVE TROUGH OVER NORTHCENTRAL
COLORADO. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER OUR
CWA...WITH A STATIONARY FRONT EXTENDING FROM NORTHEAST COLORADO
ACROSS NORTHCENTRAL NEBRASKA.
THIS AFTERNOON-TONIGHT...AS FIRST H7 TROUGH HAS WEAKENED AND SHIFTED
EAST SUBSIDENCE HAS SPREAD INTO THE WESTERN PART OF THE FORECAST
AREA WITH LOWER TD VALUES (UPPER 40S/LOWER 50S) ADVECTING INTO THE
WESTERN PARTS OF THE FORECAST AREA. RESULT HAS BEEN CAPE VALUES
DROPPING OFF SHARPLY AND SABLE AIR MOVING BACK OVER THE CWA. SHORT
RANGE GUIDANCE CONTINUES TO KEEP HIGHER TD/CAPE VALUES IN OUR
EASTERN CWA WITH ONLY 100-500 J/KG IN THE WEST THROUGH THE EVENING.
CAPE VALUES AROUND 2000 J/KG ACROSS OUR EASTERN CWA COULD SUPPORT A
FEW MARGINALLY SEVERE THUNDERSTORMS IF SOMETHING WAS TO DEVELOP
ALONG WHAT IS LIKELY A DEVELOPING DRY LINE. NOT A LOT OF CONFIDENCE
AND HI RES GUIDANCE HAS TRENDED AWAY FROM ADDITIONAL DEVELOPMENT IN
OUR EAST. IT APPEARS THAT CHANCES ARE DECREASING FOR MOST OF THE CWA
THIS AFTERNOON. THERE IS THE POSSIBILITY FOR A SHOWER OR
THUNDERSTORM IN THE WESTERN CWA AS ANOTHER SHORTWAVE MOVES IN FROM
THE WEST LATE THIS AFTERNOON THROUGH THIS EVENING...WITH BEST
PRECIP SIGNAL IN THE SW. NOT A LOT OF CONFIDENCE AT THIS POINT IN
COVERAGE...SO I DECIDED TO LIMIT POPS TO THE WEST THIS EVENING
WITH A DOWNWARD TREND THROUGH 06Z.
IT DOES APPEAR THAT HIGHER TD VALUES WILL BEGIN TO RECOVER OVERNIGHT
FROM THE EAST/NORTHEAST WITH SURFACE HIGH PRESSURE/LOW LEVEL
STABILITY SUPPORTING POSSIBLE FOG/STRATUS DEVELOPMENT. BASED ON
SHORT RANGE GUIDANCE AND PERSISTENCE I KEPT HIGHER FOG COVERAGE
(AREAS) LIMITED TO REPUBLICAN RIVER VALLEY IN SW NEBRASKA.
MONDAY...GUIDANCE CONTINUES TO SHOW PRECIP SIGNAL LINGERING ACROSS
THE SW PART OF OUR CWA. ANY SHORTWAVE TROUGHS/VORT MAXES ROTATING
THROUGH PERIPHERY OF THE RIDGE APPEAR TO REMAIN SW OF OUR CWA WITH
VERY LIMITED FORCING. INSTABILITY DOES BEGIN TO INCREASE SO IF
ACTIVITY WAS TO DEVELOP TO THE WEST WE COULD SEE DEVELOPMENT TOWARDS
THE SW PART OF OUR FORECAST AREA. I WASNT CONFIDENT ENOUGH TO
INCREASE POPS DESPITE OVERLAPPING QPF FIELDS IN GUIDANCE...SO I
LIMITED POPS TO 20/30 RANGE MONDAY AFTERNOON. HIGH TEMPS AS WITH THE
LAST FEW DAYS WILL BE HIGHLY DEPENDENT ON MORNING STRATUS CLEARING
WHICH IS CURRENTLY EXPECTED. RESULT SHOULD BE SEASONAL HIGHS IN THE
UPPER 80S/AROUND 90.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM MDT SUN AUG 9 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. SOUTHERN UNITED STATES RIDGE REMAINS CENTERED
OVER CENTRAL/EASTERN TEXAS.
MODELS STARTED OUT FINE AT JET LEVEL. AT MID LEVELS...THE
GFS/CANADIAN WERE INITIALLY DOING BETTER THAN THE REST OF THE OUT
WITH THE NAM/SREF THE WORST OF THE REST OF THE BUNCH. THE SREF
LOOKED LIKE IT WAS THE BEST AT THE SURFACE. IT LOOKED LIKE THE
GFS...CANADIAN AND ECMWF WERE DOING THE BEST ON THE LOW LEVEL
THERMAL FIELD AT THIS TIME.
MONDAY NIGHT...LOW LEVEL UPSLOPE WINDS WILL BE IN PLACE THROUGH THE
NIGHT AS SURFACE RIDGE NOSES DOWN INTO THE AREA. AS SHOWN THE LAST
TWO DAYS...THE SHORTWAVE RIDGE AT 700 MB WILL SLOWLY MOVE TOWARD THE
EAST THROUGH THE NIGHT AS A SHORTWAVE MOVES IN FROM THE WEST. MODELS
HAVE SLOWED THINGS UP A LITTLE...AS HAS THE TREND BEEN THE LAST FEW
DAYS AS WELL. THE GFS IS THE FURTHEST EAST WHICH IS NOT AN UCOMMON
THING WHEN IT COMES TO BREAKING DOWN RIDGES TOO FAST.
SO ONLY PROGRESSED THE POPS SLOWLY TO THE EAST THROUGH THE NIGHT.
THE COMBINATION OF SLOW STORM MOVEMENT...PWS OF 1 TO 1.5 INCHES AND
THE COMMON HEAVY RAIN SCENARIO OF A SHORTWAVE MOVING UP THE WEST
SIDE OF A RIDGE COULD PRODUCE SOME LOCALIZED HEAVY RAINFALL. RAMPED
THE AMOUNTS UP A LITTLE AND INCREASED THE INTENSITY OF THE RAINFALL
AS WELL. THE BEST CHANCE FOR RAINFALL WILL BE IN THE SOUTHWEST THIRD
TO HALF OF THE AREA. THIS PERIOD WILL NEED TO BE WASHED CLOSELY.
TUESDAY/TUESDAY NIGHT...SLOWLY EVOLVING SITUATION THAT BEGINS MONDAY
NIGHT...SLOWLY MOVING CONVECTIVELY INDUCED SYSTEM...CONTINUE THROUGH
THIS ENTIRE PERIOD. MODELS ARE IN GOOD AGREEMENT ABOUT THIS. MORE
THAN LIKELY SOME DEGREE OF CONVECTION WILL CONTINUE FROM THIS
PREVIOUS THROUGH THIS ENTIRE PERIOD. AGAIN SAME HEAVY RAIN SCENARIO
IS IN PLACE AS IN THE PREVIOUS PERIOD AND WILL HAVE TO BE WATCHED
CLOSELY. ALSO THE SOUTHWEST THIRD TO HALF WILL HAVE THE BEST CHANCE
OF RAINFALL...ESPECIALLY DURING THE DAY. THE AREA OF RAINFALL WILL
SLOWLY MOVE TO THE SOUTH AND EAST DURING THE NIGHT.
COMBINATION OF UPSLOPE SURFACE WINDS...LOTS OF CLOUD COVER AND
ONGOING PRECIPITATION...WILL KEEP TEMPERATURES FROM WARMING UP TOO
MUCH...ESPECIALLY IN THE SOUTHWEST HALF. SO LOWERED TEMPERATURES
AROUND 5 DEGREES OR SO. THE COOLEST OUTPUT HAS TEMPERATURES COOLER
THAN WHAT I HAVE THEM.
WEDNESDAY...SLOW MOVING UPPER SYSTEM WILL KEEP RAINFALL AROUND
THROUGH THE MORNING HOURS IN THE SOUTHEAST HALF. IF THERE IS ANY
MORE SLOWLY...THE POPS WILL NEED TO BE RAISED. TEMPERATURES WILL BE
A LITTLE WARMER BUT HOW MUCH WILL DEPEND ON HOW FAST THE SYSTEM AND
ASSOCIATED CLOUDS/RAINFALL MOVE OUT OF THE AREA. AGAIN IF ANY MORE
SLOWING TEMPERATURES WILL NEED TO BE LOWERED.
WEDNESDAY NIGHT THROUGH SUNDAY...NOT TOO MUCH HAS CHANGED FROM WHAT
THE MODELS HAVE BEEN DOING/SHOWING FROM THE LAST FEW DAYS. MODELS
STILL DIFFER ON THE AMPLITUDED AND POSITION OF WHAT IS NOW THE
SOUTHERN RIDGE THAT TRANSITIONS TO A MORE CENTERED WESTERN RIDGE. IN
GENERAL UPPER RIDGE STAYS CENTERED NEAR THE FOUR CORNERS REGION.
SINCE MUCH DOES CHANGE ALOFT...THE SURFACE ALSO DOES NOT CHANGE TOO
MUCH. A SURFACE TROUGH OR LINGERING FRONTAL BOUNDARY STAYS NEAR OR
OVER THE WESTERN PORTION OF THE AREA.
FORECAST WILL HINGE ON SMALL IMPORTANT DETAILS THAT WILL BE HARD TO
PIN DOWN AT THIS TIME SCALE. POSITION OF THE RIDGE SHOULD ALLOW
SUBTROPICAL MOISTURE/WEAK SHORTWAVE TROUGHS TO ROTATE AROUND THE
RIDGE INTO THE AREA. ALSO THE SURFACE BOUNDARY SHOULD HELP SET
THUNDERSTORMS OFF. THERE WILL NOT BE HIGH PRECIPITATION CHANCES BUT
HARD TO SAY THERE WILL NOT BE ANYTHING AT ALL. PER THE OVERNIGHT
DISCUSSION/REASONING...THE WESTERN PORTION OF THE AREA WILL PROBABLY
SEE THE BEST CHANCE DUE TO THE PROXIMITY OF THE SURFACE BOUNDARY.
THE NEW CRH_INIT IS IN GOOD AGREEMENT WITH THE ABOVE MENTIONED
SCENARIO/REASONING...SO ONCE AGAIN MADE NO CHANGES TO IT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 521 PM MDT SUN AUG 9 2015
VFR CONDITIONS ARE EXPECTED AT KGLD FOR THE NEXT 24 HOURS. KMCK
WILL BE VFR BUT NOT FOR THE ENTIRE TIME. LATER TONIGHT BOUNDARY
LAYER RH INCREASES TO 90 PERCENT OR MORE IN AN AREA INCLUDING
KMCK. VFR CONDITIONS WILL RETURN TO KMCK BY MID MORNING. LATER
MONDAY AFTERNOON THERE IS A SLIGHT CHANCE OF THUNDERSTORMS NEAR
KGLD BUT WILL HOLD OFF MENTIONING VCTS DUE TO LATER TIMING OF
STORMS INTO KGLD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
451 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERAL WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM
FRONT IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE
WEAK SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE
FORECAST AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY
LINGER THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE
EVENING HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND
TO SUPPORT POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM MDT SAT AUG 8 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. THIS FLOW BECOMES MORE OF A SPLIT WITH THE
TROUGHS OVER THE WESTERN AND EASTERN PORTIONS OF THE COUNTRY. OLD
CUTOFF LOW IS NOW BEING EJECTED INTO THE NORTH CENTRAL PORTION OF
THE COUNTRY. MONSOONAL MOISTURE CONTINUES TO PULLED UP INTO THE
REGION WITH EMBEDDED SHORTWAVE TROUGHS WITHIN THIS FLOW. AIR MASS
REMAINS MOIST THROUGH A SIGNIFICANT DEPTH.
AT JET LEVEL...THE GFS FOLLOWED BY THE NAM/CANADIAN WERE INITIALLY
DOING THE BEST HERE. AT MID LEVELS...MODELS WERE CLOSE WITH THE
GFS/CANADIAN/UKMET DOING SLIGHTLY BETTER. THE SREF AND NAM WERE
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. MODELS WERE
HAVING A LITTLE TROUBLE ON THE LOW LEVEL THERMAL FIELD...THEY TENDED
TO BE TOO COOL. OVERALL WOULD HAVE TO GIVE A SLIGHT EDGE TO THE NAM
AND SREF.
SUNDAY NIGHT...LOOKS LIKE SOME WEAK BOUNDARY SAGS SOUTH ACROSS THE
AREA. MODELS ARE A LITTLE FASTER IN TAKING THE INITIAL SHORTWAVE
THROUGH ALTHOUGH THERE IS NOT VERY GOOD AGREEMENT IN THAT. MODELS
WANT TO BRING ANOTHER SHORTWAVE IN NORTHWEST FLOW DURING THE
OVERNIGHT HOURS WITH ALSO NOT A LOT OF AGREEMENT. RIGHT REAR
QUADRANT AFFECTS THE FAR NORTHERN PORTION OF THE AREA. WILL KEEP THE
SLIGHT TO LOW CHANCE POPS WITH A GRADUAL DECREASE THROUGH THE NIGHT.
LOOKS LIKE THERE WILL BE MAINLY STRATUS WITH NOT AS GOOD OF A CHANCE
OF FOG.
MONDAY/MONDAY NIGHT...RIDGE BEGINS TO BUILD INTO THE AREA WITH THE
UPPER JET BEING PUSHED FURTHER NORTH AWAY FROM THE AREA. AREA IS IN
POST FRONTAL UPSLOPE REGIME. RIDGING ALOFT LOOKS A LITTLE STRONGER
AND FURTHER WEST DURING THE DAY THAN WAS SHOWN YESTERDAY SO WILL
PUSH THE POPS FURTHER WEST. WILL HAVE SOME CLOUD COVER TO START THE
DAY WITH A COOLER AIR MASS AND UPSLOPE WINDS PRESENT THROUGH THE DAY
SO WILL DEFINITELY BE COOLER.
700 MB RIDGE MOVES A LITTLE TO THE EAST DURING THE NIGHT WITH
INCREASING LIFT COMING IN FROM THE SOUTHWEST. SO POPS SHOULD STAY
CONFINED TO THE SOUTHWEST HALF OF THE AREA WITH A GRADUAL INCREASE
THROUGH WITH STORMS NOT MOVING VERY FAST. THAT COMBINED WITH HIGH
PWS WILL SET THE STAGE MODERATE TO LOCALLY HEAVY RAINFALL.
TUESDAY...ABOVE MENTIONED SHORTWAVE RIDGE AND TROUGH CONTINUE TO
MOVE SLOWLY EAST THROUGH THE DAY. MOIST AIR MASS REMAIN IN PLACE
WITH INCREASING LIFT. IT IS POSSIBLE THAT THERE COULD BE SOME
PRECIPITATION AT THE BEGINNING AND THEN IT SHOULD GRADUALLY
INCREASE IN COVERAGE AND INTENSITY. SO HAVE THE HIGHER POPS IN THE
AFTERNOON.
EASTERLY WINDS...CLOUD COVER AND DEVELOPING PRECIPITATION SHOULD
KEEP TEMPERATURES SHOULD KEEP TEMPERATURES FROM WARMING VERY MUCH.
TUESDAY NIGHT THROUGH SATURDAY...DETERMINISTIC AND ENSEMBLE OUTPUT
IN BETTER AGREEMENT IN REGARDS TO THE EVOLUTION OF THE UPPER
PATTERN. ESSENTIALLY MODELS BUILD THE RIDGE...NOW CENTERED TO OUR
SOUTH...FURTHER TO THE WEST AND NORTH. THE DIFFERENCES INCREASE A
LITTLE TOWARD THE END OF THE PERIOD BUT NOT AS BAD AS YESTERDAY. THE
CENTER OF THE RIDGE WILL BE NEAR THE FOUR CORNERS REGION LEAVING A
WEAKER NORTHERLY FLOW OVER THE AREA.
IN THIS PATTERN WOULD ANTICIPATE THE SUBTROPICAL MOISTURE TO BE ABLE
TO ROTATE AROUND THE RIDGE WITH WEAK/SUBTLE SHORTWAVES ROTATING
AROUND IT. WPC PROGS SHOW A PERSISTENT FRONTAL BOUNDARY ALONG OR
OVER THE WESTERN PORTION OF THE AREA UNTIL THE LAST DAY WHEN A DRY
LINE/SURFACE TROUGH SETS UP IN THE SAME PLACE. WITH VERY SUBTLE
FEATURES...I CANNOT RULE OUT CHANCES FOR THUNDERSTORMS ALMOST EVERY
PERIOD.
SO ANY SLIGHT CHANCE TO LOW CHANCE POPS TO DRY CONDITIONS DO NOT
SEEM UNREASONABLE DEPENDING ON HOW THE DETAILS WORK OUT. SO ONCE
AGAIN DID NOT MAKE ANY CHANGES TO WHAT THE CRH_INIT GAVE ME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 440 PM MDT SAT AUG 8 2015
VFR CONDITIONS WILL CONTINUE THIS EVENING FOR KGLD AND KMCK. A
SHORTWAVE MOVING THROUGH THE REGION WILL BRING A SLIGHT CHANCE OF
A THUNDERSTORM TO KGLD THIS EVENING WITH A LESSER CHANCE AT KMCK.
OVERNIGHT BOUNDARY LAYER MOISTURE INCREASES TO THE POINT THAT
STRATUS AND FOG AND RESULTING MVFR CONDTIONS CAN BE EXPECTED AT
KGLD. CIGS AT KMCK SHOULD NOT BE AS LOW AS KGLD BUT WILL STILL BE
MVFR. VFR CONDITIONS RETURN BY LATE SUNDAY MORNING AND CONTINUE
THROUGH THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
309 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERAL WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM
FRONT IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE
WEAK SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE
FORECAST AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY
LINGER THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE
EVENING HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND
TO SUPPORT POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM MDT SAT AUG 8 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. THIS FLOW BECOMES MORE OF A SPLIT WITH THE
TROUGHS OVER THE WESTERN AND EASTERN PORTIONS OF THE COUNTRY. OLD
CUTOFF LOW IS NOW BEING EJECTED INTO THE NORTH CENTRAL PORTION OF
THE COUNTRY. MONSOONAL MOISTURE CONTINUES TO PULLED UP INTO THE
REGION WITH EMBEDDED SHORTWAVE TROUGHS WITHIN THIS FLOW. AIR MASS
REMAINS MOIST THROUGH A SIGNIFICANT DEPTH.
AT JET LEVEL...THE GFS FOLLOWED BY THE NAM/CANADIAN WERE INITIALLY
DOING THE BEST HERE. AT MID LEVELS...MODELS WERE CLOSE WITH THE
GFS/CANADIAN/UKMET DOING SLIGHTLY BETTER. THE SREF AND NAM WERE
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. MODELS WERE
HAVING A LITTLE TROUBLE ON THE LOW LEVEL THERMAL FIELD...THEY TENDED
TO BE TOO COOL. OVERALL WOULD HAVE TO GIVE A SLIGHT EDGE TO THE NAM
AND SREF.
SUNDAY NIGHT...LOOKS LIKE SOME WEAK BOUNDARY SAGS SOUTH ACROSS THE
AREA. MODELS ARE A LITTLE FASTER IN TAKING THE INITIAL SHORTWAVE
THROUGH ALTHOUGH THERE IS NOT VERY GOOD AGREEMENT IN THAT. MODELS
WANT TO BRING ANOTHER SHORTWAVE IN NORTHWEST FLOW DURING THE
OVERNIGHT HOURS WITH ALSO NOT A LOT OF AGREEMENT. RIGHT REAR
QUADRANT AFFECTS THE FAR NORTHERN PORTION OF THE AREA. WILL KEEP THE
SLIGHT TO LOW CHANCE POPS WITH A GRADUAL DECREASE THROUGH THE NIGHT.
LOOKS LIKE THERE WILL BE MAINLY STRATUS WITH NOT AS GOOD OF A CHANCE
OF FOG.
MONDAY/MONDAY NIGHT...RIDGE BEGINS TO BUILD INTO THE AREA WITH THE
UPPER JET BEING PUSHED FURTHER NORTH AWAY FROM THE AREA. AREA IS IN
POST FRONTAL UPSLOPE REGIME. RIDGING ALOFT LOOKS A LITTLE STRONGER
AND FURTHER WEST DURING THE DAY THAN WAS SHOWN YESTERDAY SO WILL
PUSH THE POPS FURTHER WEST. WILL HAVE SOME CLOUD COVER TO START THE
DAY WITH A COOLER AIR MASS AND UPSLOPE WINDS PRESENT THROUGH THE DAY
SO WILL DEFINITELY BE COOLER.
700 MB RIDGE MOVES A LITTLE TO THE EAST DURING THE NIGHT WITH
INCREASING LIFT COMING IN FROM THE SOUTHWEST. SO POPS SHOULD STAY
CONFINED TO THE SOUTHWEST HALF OF THE AREA WITH A GRADUAL INCREASE
THROUGH WITH STORMS NOT MOVING VERY FAST. THAT COMBINED WITH HIGH
PWS WILL SET THE STAGE MODERATE TO LOCALLY HEAVY RAINFALL.
TUESDAY...ABOVE MENTIONED SHORTWAVE RIDGE AND TROUGH CONTINUE TO
MOVE SLOWLY EAST THROUGH THE DAY. MOIST AIR MASS REMAIN IN PLACE
WITH INCREASING LIFT. IT IS POSSIBLE THAT THERE COULD BE SOME
PRECIPITATION AT THE BEGINNING AND THEN IT SHOULD GRADUALLY
INCREASE IN COVERAGE AND INTENSITY. SO HAVE THE HIGHER POPS IN THE
AFTERNOON.
EASTERLY WINDS...CLOUD COVER AND DEVELOPING PRECIPITATION SHOULD
KEEP TEMPERATURES SHOULD KEEP TEMPERATURES FROM WARMING VERY MUCH.
TUESDAY NIGHT THROUGH SATURDAY...DETERMINISTIC AND ENSEMBLE OUTPUT
IN BETTER AGREEMENT IN REGARDS TO THE EVOLUTION OF THE UPPER
PATTERN. ESSENTIALLY MODELS BUILD THE RIDGE...NOW CENTERED TO OUR
SOUTH...FURTHER TO THE WEST AND NORTH. THE DIFFERENCES INCREASE A
LITTLE TOWARD THE END OF THE PERIOD BUT NOT AS BAD AS YESTERDAY. THE
CENTER OF THE RIDGE WILL BE NEAR THE FOUR CORNERS REGION LEAVING A
WEAKER NORTHERLY FLOW OVER THE AREA.
IN THIS PATTERN WOULD ANTICIPATE THE SUBTROPICAL MOISTURE TO BE ABLE
TO ROTATE AROUND THE RIDGE WITH WEAK/SUBTLE SHORTWAVES ROTATING
AROUND IT. WPC PROGS SHOW A PERSISTENT FRONTAL BOUNDARY ALONG OR
OVER THE WESTERN PORTION OF THE AREA UNTIL THE LAST DAY WHEN A DRY
LINE/SURFACE TROUGH SETS UP IN THE SAME PLACE. WITH VERY SUBTLE
FEATURES...I CANNOT RULE OUT CHANCES FOR THUNDERSTORMS ALMOST EVERY
PERIOD.
SO ANY SLIGHT CHANCE TO LOW CHANCE POPS TO DRY CONDITIONS DO NOT
SEEM UNREASONABLE DEPENDING ON HOW THE DETAILS WORK OUT. SO ONCE
AGAIN DID NOT MAKE ANY CHANGES TO WHAT THE CRH_INIT GAVE ME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM MDT SAT AUG 8 2015
1500-2500 KFT STRATUS SHOULD CLEAR BY THE VALID TAF PERIOD AT KGLD.
SHORT RANGE GUIDANCE AND SATELLITE TRENDS INDICATE THIS SHOULD
WILL LINGER AT KMCK THROUGH THE EARLY AFTERNOON BEFORE LIFTING.
SCATTERED THUNDERSTORM WILL DEVELOP MAINLY SOUTH OF INTERSTATE
70...WITH ACTIVITY MOVING WITHIN THE VICINITY OF KGLD AFTER 00Z.
NOT A LOT OF CONFIDENCE COVERAGE AT KGLD WILL NECESSITATE MORE
THAN VCTS MENTION AT THIS POINT...SO WE WILL NEED TO MONITOR
TRENDS AS THUNDERSTORMS INITIATE SOUTH AND TRACK NORTHEAST. WITH
VERY MOIST AIR MASS IN PLACE EXPECT STRATUS/FOG TO REDEVELOP
09-10Z. THERE IS A POSSIBILITY BASED ON HI RES GUIDANCE OF VLIFR
CONDITIONS AROUND 12Z AT KGLD AND KMCK...HOWEVER GUIDANCE ISNT
SHOWING A LOT OF CONSISTENCY AND IT MAY END UP BEING MORE OF A
TEMPORARY CONDITION. IN ANY CASE STRATUS/FOG SHOULD CLEAR WITH
RISING SUN MID MORNING SUNDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
229 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERE WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM FRONT
IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE WEAK
SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE FORECAST
AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY LINGER
THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE EVENING
HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND TO SUPPORT
POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 222 AM MDT SAT AUG 8 2015
AN UPPER LEVEL RIDGE WILL BE IN PLACE OVER THE TRI STATE AREA TO
START OFF THE LONG TERM PERIOD TUESDAY. THE CENTRAL AREA OF HIGH
PRESSURE WILL CONTINUE TO RETROGRADE AND INCREASE IN AMPLITUDE OVER
THE ROCKY MOUNTAIN RANGE AND THE NORTHERN PLAINS WEDNESDAY. WITH
THE PRESENCE OF THE UPPER RIDGE...JET AREAS AND POCKETS OF VORTICITY
WILL REMAIN WELL AWAY FROM THE TRI STATE AREA...WHICH WILL BRING
UPPER STABILITY FOR THE REST OF THE FORECAST PERIOD.
AT THE SURFACE...A COOLER AIR MASS WITH A SURFACE HIGH PRESSURE
FILTERING INTO THE PLAINS BEHIND A COLD FRONTAL PASSAGE WILL BRING
COOLER HIGH TEMPERATURES IN THE MID TO UPPER 80S ON TUESDAY. ON THE
FRONT SIDE OF THE HIGH PRESSURE SYSTEM...EASTERLY UPSLOPE FLOW WILL
BRING MOISTURE INTO THE HIGH PLAINS DURING THE MORNING HOURS BEFORE
SURFACE WINDS SHIFT TO THE SOUTH/SOUTHEAST. GFS/ECMWF HINT AT A
SURFACE DRY LINE POSITIONED MORE ALONG THE SOUTHWESTERN PORTION OF
THE FORECAST AREA...SO THUNDERSTORMS LOOK MORE LIKELY TO FORM ALONG
THE VICINITY OF THE FORECAST AREA ALONG THIS BOUNDARY. A DEVELOPING
SURFACE TROUGH IN EASTERN COLORADO MAY ALLOW STORMS TO DEVELOP
ELSEWHERE WITH CAPE AND MOISTURE PROFILES SUFFICIENT ENOUGH FOR
DEVELOPMENT.
THE UPPER LEVEL HIGH WILL THEN MOVE AND BECOME POSITIONED DIRECTLY
OVER THE TRI STATE AREA FOR THE END OF THE COMING WEEK...WHICH WILL
DRY OUT CONDITIONS WITH A LACK OF UPPER OR SURFACE FORCING.
EXPECTING TEMPERATURES IN THE LOW TO MID 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1139 AM MDT SAT AUG 8 2015
1500-2500 KFT STRATUS SHOULD CLEAR BY THE VALID TAF PERIOD AT KGLD.
SHORT RANGE GUIDANCE AND SATELLITE TRENDS INDICATE THIS SHOULD
WILL LINGER AT KMCK THROUGH THE EARLY AFTERNOON BEFORE LIFTING.
SCATTERED THUNDERSTORM WILL DEVELOP MAINLY SOUTH OF INTERSTATE
70...WITH ACTIVITY MOVING WITHIN THE VICINITY OF KGLD AFTER 00Z.
NOT A LOT OF CONFIDENCE COVERAGE AT KGLD WILL NECESSITATE MORE
THAN VCTS MENTION AT THIS POINT...SO WE WILL NEED TO MONITOR
TRENDS AS THUNDERSTORMS INITIATE SOUTH AND TRACK NORTHEAST. WITH
VERY MOIST AIR MASS IN PLACE EXPECT STRATUS/FOG TO REDEVELOP
09-10Z. THERE IS A POSSIBILITY BASED ON HI RES GUIDANCE OF VLIFR
CONDITIONS AROUND 12Z AT KGLD AND KMCK...HOWEVER GUIDANCE ISNT
SHOWING A LOT OF CONSISTENCY AND IT MAY END UP BEING MORE OF A
TEMPORARY CONDITION. IN ANY CASE STRATUS/FOG SHOULD CLEAR WITH
RISING SUN MID MORNING SUNDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
501 AM CDT SAT AUG 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM CDT SAT AUG 8 2015
THUNDERSTORMS WERE MOVING ACROSS NORTH CENTRAL AND NORTHEAST
KANSAS THIS MORNING AT 09Z. THE LOW LEVEL JET HAS HELPED TO
MAINTAIN THE CONVECTION AS IT MOVES ACROSS THE CWA THIS MORNING.
THE STORMS ARE EXPECTED TO MOVE ACROSS NORTHEAST AND EAST CENTRAL
KANSAS THIS MORNING. THIS MAY COMPLICATE THE TEMPERATURE FORECAST
FOR LATER TODAY, BUT FOR NOW WILL CONTINUE WITH TEMPERATURES
REACHING THE LOWER 90S NEAR THE NEBRASKA BORDER TO AROUND 100 NEAR
CENTRAL KANSAS. AFTERNOON HEAT INDICES WILL RANGE FROM 105 TO 109
AND WILL KEEP THE HEAT ADVISORY GOING AS IS FOR TODAY.
THUNDERSTORMS ARE FORECAST TO REDEVELOP THIS AFTERNOON AND EVENING
NEAR A SURFACE TROUGH ACROSS SOUTHERN NEBRASKA AND BUILD SOUTHWEST
INTO NORTH CENTRAL KANSAS. A WAVE IS EXPECTED TO MOVE ACROSS
NEBRASKA AND NORTHERN KANSAS THIS EVENING AND INTO MISSOURI AND
IOWA BY SUNDAY MORNING. SHEAR AND INSTABILITY WILL BE FAVORABLE
FOR STRONG TO SEVERE CONVECTION AND WIND PROFILES SHOWING LARGE
LOOPED HODOGRAPHS, SO EXPECT LARGE HAIL, DAMAGING WINDS AND A
POSSIBLE TORNADO AS THE MAIN HAZARDS. HIGH MOISTURE CONTENT IN THE
ATMOSPHERE WILL LEAD TO RAINFALL RATES NEAR 2 INCHES PER HOUR
WHICH MAY LEAD TO FLASH FLOODING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM CDT SAT AUG 8 2015
EARLY MORNING SUNDAY A SHORTWAVE IS EXPECTED TO MOVE ACROSS EASTERN
NEBRASKA AND INTO IOWA WHILE A SURFACE FRONT EXTENDS ACROSS THE
FORECAST AREA. EXPECT SCATTERED THUNDERSTORMS MAY BE ONGOING TO
START THE MORNING BEFORE MOVING OFF TO THE EAST. THE FRONTAL
BOUNDARY IS EXPECTED TO MOVE INTO EAST CENTRAL KANSAS GENERALLY
SOUTH OF INTERSTATE 35 BY LATE AFTERNOON. ANOTHER WAVE WILL EJECT
OUT OF THE ROCKIES AND MOVE ACROSS NORTHERN KANSAS IN THE AFTERNOON
AND THEN PHASE WITH A LONGER WAVELENGTH TROUGH DROPPING SOUTHEAST
FROM THE NORTHERN PLAINS SUNDAY NIGHT. MOISTURE WILL POOL NEAR AND
SOUTH OF THE BOUNDARY AS PRECIPITABLE WATER VALUES REMAIN AROUND
TWO INCHES. EXPECT ANOTHER ROUND OF STORMS TO DEVELOP NEAR THE
BOUNDARY WITH ELEVATED STORMS TO THE NORTH. LOW LEVEL JET WILL
INCREASE ISENTROPIC LIFT TO THE NORTH OF THE BOUNDARY INITIALLY,
BEFORE VEERING TO THE SOUTHWEST BY MONDAY MORNING. SHEAR AND
INSTABILITY WILL BE SUPPORTIVE OF A FEW STRONG STORMS SUNDAY
AFTERNOON AND SUNDAY NIGHT. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE
ESPECIALLY ACROSS EAST CENTRAL KANSAS. THE UPPER TROUGH WILL MOVE
OFF TO THE EAST BRINING AN END TO PRECIPITATION DURING THE DAY. THE
UPPER RIDGE THEN AMPLIFIES ACROSS THE ROCKIES INTO CENTRAL CANADA
AND SHARPENS IN THE TUESDAY THROUGH FRIDAY TIME PERIOD. SURFACE HIGH
PRESSURE WILL SLIDE INTO THE CENTRAL PLAINS AND REMAIN FOR MUCH OF
THE TUESDAY THROUGH FRIDAY TIME PERIOD. UPSLOPE CONVECTION ALONG THE
FRONT RANGE AND HIGH PLAINS IS EXPECTED TO REMAIN TO THE WEST OF THE
FORECAST AREA SO WILL MAINTAIN A DRY FORECAST. TEMPERATURES SUNDAY
WILL WARM INTO THE LOWER TO MID 90S SOUTH OF THE FRONT WITH MID 80S
NEAR THE NEBRASKA BORDER. AFTERNOON HEAT INDICES IN EAST CENTRAL
KANSAS WILL TOP OUT IN THE 100 TO 102 DEGREE RANGE. BELOW NORMAL
TEMPERATURES IN THE 80S ARE EXPECTED FOR THE REST OF THE PERIOD WITH
LOWS IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI AUG 7 2015
THERE IS QUITE A BIT OF UNCERTAINTY IN WHERE THE MCS WILL GO
DURING THE EARLY MORNING HOURS. THE HRRR HAS BEEN CONSISTENTLY
BRINGING THE ELEVATED STORMS THROUGH EASTERN KS, ALTHOUGH IT SEEMS
TO BE DELAYING THE PROGRESS TO MORE MID MORNING. MEANWHILE THE
OPERATIONAL MODELS CONTINUE TO FOCUS THE MOST LIKELY TRACK OF THE
STORMS ACROSS SOUTHERN NEB AND FAR NORTHERN KS. WITH PROFILER DATA
SHOWING THE DECENT LOW LEVEL JET VEERING TO THE SOUTH AND
SOUTHWEST, THINK THERE IS A CHANCE FOR ELEVATED STORMS TO MOVE
INTO THE TERMINALS SO WILL INCLUDE A VCTS WITH VFR CONDITIONS AND
MONITOR TRENDS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TODAY TO 9 PM CDT THIS EVENING FOR
KSZ010>012-021>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...65/53
LONG TERM...53
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
223 AM MDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 1018 PM MDT FRI AUG 7 2015
UPDATE SENT TO CANCEL SEVERE THUNDERSTORM WATCH FOR THE ENTIRE
AREA. SEVERE THREAT HAS SHIFTED EAST OF THE CWA...BUT DO EXPECT
SCATTERED RW/TRW TO PERSIST BUT TAPER AS THE OVERNIGHT HRS
PROGRESS. FLASH FLOOD WARNING REMAINS IN EFFECT FOR HITCHCOCK
COUNTY IN NEBRASKA. CONCERN IS FOR HEAVY RAINFALL THAT OCCURRED
JUST TO THE NORTH EARLIER THIS EVENING IN CHASE/HAYS COUNTIES...
WILL FILTER SOUTH VIA THE FRENCHMEN CREEK AND AFFECT AREAS LIKE
STRATTON...CULBERTSON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 222 AM MDT SAT AUG 8 2015
AN UPPER LEVEL RIDGE WILL BE IN PLACE OVER THE TRI STATE AREA TO
START OFF THE LONG TERM PERIOD TUESDAY. THE CENTRAL AREA OF HIGH
PRESSURE WILL CONTINUE TO RETROGRADE AND INCREASE IN AMPLITUDE OVER
THE ROCKY MOUNTAIN RANGE AND THE NORTHERN PLAINS WEDNESDAY. WITH
THE PRESENCE OF THE UPPER RIDGE...JET AREAS AND POCKETS OF VORTICITY
WILL REMAIN WELL AWAY FROM THE TRI STATE AREA...WHICH WILL BRING
UPPER STABILITY FOR THE REST OF THE FORECAST PERIOD.
AT THE SURFACE...A COOLER AIR MASS WITH A SURFACE HIGH PRESSURE
FILTERING INTO THE PLAINS BEHIND A COLD FRONTAL PASSAGE WILL BRING
COOLER HIGH TEMPERATURES IN THE MID TO UPPER 80S ON TUESDAY. ON THE
FRONT SIDE OF THE HIGH PRESSURE SYSTEM...EASTERLY UPSLOPE FLOW WILL
BRING MOISTURE INTO THE HIGH PLAINS DURING THE MORNING HOURS BEFORE
SURFACE WINDS SHIFT TO THE SOUTH/SOUTHEAST. GFS/ECMWF HINT AT A
SURFACE DRY LINE POSITIONED MORE ALONG THE SOUTHWESTERN PORTION OF
THE FORECAST AREA...SO THUNDERSTORMS LOOK MORE LIKELY TO FORM ALONG
THE VICINITY OF THE FORECAST AREA ALONG THIS BOUNDARY. A DEVELOPING
SURFACE TROUGH IN EASTERN COLORADO MAY ALLOW STORMS TO DEVELOP
ELSEWHERE WITH CAPE AND MOISTURE PROFILES SUFFICIENT ENOUGH FOR
DEVELOPMENT.
THE UPPER LEVEL HIGH WILL THEN MOVE AND BECOME POSITIONED DIRECTLY
OVER THE TRI STATE AREA FOR THE END OF THE COMING WEEK...WHICH WILL
DRY OUT CONDITIONS WITH A LACK OF UPPER OR SURFACE FORCING.
EXPECTING TEMPERATURES IN THE LOW TO MID 90S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1114 PM MDT FRI AUG 7 2015
SCATTERED SHOWERS AND 6SM IN FOG WILL GIVE WAY TO 1SM OR LESS IN
FOG BY 10Z SATURDAY THRU 14Z-15Z...WITH CEILINGS OVC010 OR LESS.
FROM 14Z-15Z ONWARD...VFR CONDITIONS WITH SCT050-150. WINDS WILL
HAVE VARYING DIRECTION THRU FORECAST PERIOD WITH 5-15KTS RANGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...MK
AVIATION...JN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1114 PM MDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 1018 PM MDT FRI AUG 7 2015
UPDATE SENT TO CANCEL SEVERE THUNDERSTORM WATCH FOR THE ENTIRE
AREA. SEVERE THREAT HAS SHIFTED EAST OF THE CWA...BUT DO EXPECT
SCATTERED RW/TRW TO PERSIST BUT TAPER AS THE OVERNIGHT HRS
PROGRESS. FLASH FLOOD WARNING REMAINS IN EFFECT FOR HITCHCOCK
COUNTY IN NEBRASKA. CONCERN IS FOR HEAVY RAINFALL THAT OCCURRED
JUST TO THE NORTH EARLIER THIS EVENING IN CHASE/HAYS COUNTIES...
WILL FILTER SOUTH VIA THE FRENCHMEN CREEK AND AFFECT AREAS LIKE
STRATTON...CULBERTSON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM MDT FRI AUG 7 2015
FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES AND ANY HEAVY
RAINFALL THREAT. SATELLITE IS SHOWING AN AMPLIFIED AND MOSTLY
PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. THIS FLOW
BECOMES MORE OF A SPLIT WITH THE TROUGHS ALONG THE WEST AND EAST
COASTS. A LOT OF PACIFIC AND MONSOONAL MOISTURE IS BEING PULLED UP
INTO THE REGION. CURRENTLY A SYNOPTIC BOUNDARY REMAINS DRAPED TO
OUR SOUTH AND WEST.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...MODELS WERE
NOT TOO FAR APART. THE CANADIAN/UKMET/GFS LED THE PACK WITH OTHERS
NOT FAR BEHIND WITH THE SREF THE WORST. THE NAM/SREF WERE HANDLING
THE SURFACE WIND AND PRESSURE FIELD THE BEST. MODELS TENDED TO BE
A LITTLE COOL ON THE LOW LEVEL THERMAL FIELD WITH THE GFS/CANADIAN
DOING THE BEST.
SATURDAY NIGHT...TO BEGIN THE NIGHT...SURFACE BOUNDARY IS DRAPED
OVER THE FAR SOUTH AND WEST CENTRAL PORTION OF THE AREA. THIS
BOUNDARY GRADUALLY SINKS SOUTH THROUGH THE NIGHT. SHORTWAVE TROUGH
MOVES THROUGH FROM THE SOUTHWEST THROUGH THE NIGHT WITH THE BEST
LIFT BASICALLY OVER THE SOUTHWEST HALF. MAIN JET AXIS/LIFT STAYS NOT
TOO FAR TO OUR NORTH AND WEST THROUGH MOST OF THE PERIOD. LATE IN
THE NIGHT A RIGHT REAR QUADRANT GETS CLOSER TO THE NORTHWEST PORTION.
RIGHT NOW THE HIGHEST POPS LOOK TO BE IN THE SOUTHWEST HALF. PWS
REMAIN NEAR 1.5 INCHES. THAT WITH STORM MOTIONS ONLY 10 TO 15 KNOTS
ALONG THAT FLOW COMING OVER THE TOP OF THE SOUTHERN BOUNDARY WILL
MAKE MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE. ALSO POSSIBLE LATE
IN THE NIGHT WITH MOIST LOW LEVELS AND LITTLE TO NO WIND THAT PATCHY
FOG COULD DEVELOP WHERE NO PRECIPITATION IS GOING ON.
SUNDAY/SUNDAY NIGHT...IT LOOKS LIKE THERE MAY BE SOME LINGERING
RAINFALL AND PATCHY FOG IN THE MORNING. FOR THE REMAINDER OF THE
PERIOD...BOUNDARY LOOKS TO BE TO THE SOUTH AND WEST OF THE AREA WITH
A WEAK LOW LEVEL UPSLOPE REGIME IN PLACE. HOWEVER...MODELS ARE
HINTING AT A WEAK SECONDARY BOUNDARY MOVING INTO THE NORTHWEST HALF
OF THE AREA DURING THE LATE AFTERNOON INTO THE EVENING. THIS SINKS A
LITTLE FURTHER SOUTHEAST DURING THE LAST HALF OF THE NIGHT.
THE MID LEVEL FORCING THROUGH THE PERIOD REMAINS RATHER WEAK WITH
THE STRONGEST IN THE EVENING. RIGHT REAR QUADRANT OF THE JET REMAINS
NEAR THE NORTHERN AND WESTERN PORTIONS OF THE AREA THROUGH THE DAY
BUT GETS CLOSER/HAS MORE AFFECT ON THOSE LOCATIONS BY THE END OF THE
DAY. THE NORTHERN PORTION OF THE AREA KEEPS GETTING AFFECTED BY THIS
THROUGH THE MIDDLE OF THE NIGHT. WITH A VARIETY OF FORCING IN
DIFFERENT TIMES AND PLACES...WILL BROADBRUSH CHANCE POPS FOR THE
ENTIRE NIGHT.
FOR THE HIGH TEMPERATURES...WILL HAVE LOW LEVEL UPSLOPE IN PLACE
THROUGH THE DAY ALONG WITH LINGERING CLOUD COVER IN THE MORNING AND
DEVELOPING CLOUD COVER IN THE AFTERNOON WITH THE CONVECTION. MODEL
GUIDANCE HAS TENDED TO BE A LITTLE WARM.
MONDAY...JET REMAINS WELL NORTH OF THE AREA THROUGH THE DAY. MID
LEVEL SHORTWAVE RIDGE IS IN PLACE THROUGH THE DAY WITH A LOT OF
DRYING. A SHORTWAVE TROUGH STARTS GETTING CLOSER DURING THE END OF
THE DAY. AREA IS IN A POST FRONTAL AIR MASS. DEPENDING ON WHICH
MODEL YOU USE...THERE COULD BE A WEAK SUBTLE SURFACE BOUNDARY IN THE
FAR SOUTH/SOUTHWEST. SO AT THIS TIME...WILL HAVE SLIGHT TO LOW
CHANCE POPS IN THE FAR SOUTH AND SOUTHWEST PORTION OF THE AREA IN
THE AFTERNOON.
HIGH TEMPERATURES WILL BE COOLER THAN THE PREVIOUS DAY DUE TO LOWER
850 MB TEMPERATURES...UPSLOPE WINDS AND LINGERING MORNING FOG/STRATUS
THAT BEGINS SUNDAY NIGHT.
MONDAY NIGHT THROUGH SATURDAY...CONTINUED AMPLIFIED PATTERN
REMAINS IN PLACE THROUGH THE PERIOD. HOWEVER...THE DETERMINISTIC
AND ENSEMBLE OUTPUT SPREAD GETS WORSE WITH TIME...ALMOST
COMPLETELY OUT OF PHASE AT TIMES. THE DIFFERENCES INVOLVE HOW THE
PERSISTENT SOUTHERN UNITED STATES RIDGE AND WEST TROUGH EVOLVE
WITH TIME. IN GENERAL THE ECMWF REMAINS STRONGER WITH THE RIDGE.
FOR THE WESTERN TROUGH...ALL OUTPUT SUPPORTS A DEEPENING ALONG THE
COAST UPPER TROUGH.
DESPITE THOSE DIFFERENCES...THE CENTER OF THE RIDGE...STILL RATHER
FAR SOUTH...AND THE POSITION OF THE UPPER TROUGH SHOULD CONTINUE TO
ALLOW PACIFIC AND MONSOONAL MOISTURE TO PULLED UP INTO THE REGION
WITH PERIODIC SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW. AT THE
SURFACE...WPC GRAPHICS SHOW A PERSISTENT FRONTAL BOUNDARY STILL
DRAPED NOT TOO FAR TO OUR SOUTH AND WEST OR OVER THE AREA. THIS
KEEPS A CONTINUED UPSLOPE FLOW OVER THE AREA.
GIVEN THE BIG MODEL DIFFERENCES...THE GENERAL PATTERN SUPPORTED
CONTINUED BOUTS OF MOISTURE/LIFT/RAINFALL...AND THE PROXIMITY OF A
BOUNDARY AND UPSLOPE FLOW...SHOULD SEE A CONTINUED THREAT FOR
THUNDERSTORMS AND DO NOT FEEL COMFORTABLE MAKING ANY MAJOR
ADJUSTMENTS TO THE GUIDANCE. THE DETAILS WILL HAVE TO BE REFINED AS
WE GET CLOSER TO EACH EVENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1114 PM MDT FRI AUG 7 2015
SCATTERED SHOWERS AND 6SM IN FOG WILL GIVE WAY TO 1SM OR LESS IN
FOG BY 10Z SATURDAY THRU 14Z-15Z...WITH CEILINGS OVC010 OR LESS.
FROM 14Z-15Z ONWARD...VFR CONDITIONS WITH SCT050-150. WINDS WILL
HAVE VARYING DIRECTION THRU FORECAST PERIOD WITH 5-15KTS RANGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1135 PM CDT FRI AUG 7 2015
...AVIATION UPDATE...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 336 PM CDT FRI AUG 7 2015
ONGOING BAND OF ELEVATED SHOWERS AND THUNDERSTORMS OVER NORTH
CENTRAL KANSAS CONTINUE TO BE ROOTED AROUND 10-12 THOUSAND FEET AS
CEILINGS ARE NOT EVEN BEING MEASURED AT ASOS SITES. PARCELS LIFTED
FROM THIS LEVEL ARE LIKELY REALIZING ON THE ORDER OF 400-800 J/KG OF
CAPE AND RADAR TRENDS SUPPORT THIS AS WELL. THE BAND OF ELEVATED
FORCING/CONVERGENCE/WARM ADVECTION APPEARS LIKELY TO CONTINUE FOR A
WHILE ALTHOUGH INSTABILITY OF THESE ELEVATED PARCELS MAY WANE WITH
TIME. BOTTOM LINE IS THAT THE SCATTERED SHOWERS AND A FEW STORMS
WILL CONTINUE FOR A FEW HOURS BUT LIKELY DECREASE IN COVERAGE DURING
THE EVENING.
FARTHER WEST, A DEEP TROUGH OVER NEVADA WAS SPINNING AMPLE MOISTURE
AND ENERGY NORTHEAST ACROSS THE CENTRAL ROCKIES AND INTO THE PLAINS.
WIDESPREAD PRESSURE FALLS AND A VERY MOIST BOUNDARY LAYER OVER THE
HIGH PLAINS OF COLORADO INTO NORTH TEXAS WILL LIKELY RESULT IN
WIDESPREAD THUNDERSTORM DEVELOPMENT THIS AFTERNOON AND EVENING.
THESE STORMS APPEAR LIKELY TO CONGEAL INTO ONE OR MORE CONVECTIVE
CLUSTERS AND MOVE TO THE EAST AND NORTHEAST. THE MOST LIKELY CLUSTER
SEEMS AIMED TO MOVE ACROSS NEBRASKA TONIGHT, BUT MORE RECENT MODEL
RUNS AND OBSERVATIONAL DATA SUGGEST THE POTENTIAL FOR ANOTHER WELL
ORGANIZED CLUSTER TO DEVELOP IN SOUTHWEST KANSAS AND MOVE TOWARD THE
NORTHEAST...LIKELY IMPACTING A GOOD PART OF THE LOCAL FORECAST AREA.
WHILE THUNDERSTORMS ARE LIKELY TO DEVELOP, THEIR EVOLUTION HAS LESS
CONFIDENCE AS THEY WILL INTERACT WITH THE UPPER RIDGE, DRY AIR JUST
ABOVE THE BOUNDARY LAYER, AND A STOUT INVERSION/CAP JUST OFF THE
SURFACE. SO, HAVE LOWER POPS WITH SOUTHERN EXTENT GIVEN THE GREATER
UNCERTAINTY, BUT THE POTENTIAL DOES EXIST FOR WIDESPREAD STORMS
ESPECIALLY OVER THE NORTHERN HALF OF THE FORECAST AREA TONIGHT...
MAINLY AFTER MIDNIGHT. MODERATE INSTABILITY SHOULD BE AVAILABLE FOR
ANY STORMS THAT DO DEVELOP, BUT THE EXTENT OF COLD POOL
ORGANIZATION, ESPECIALLY GIVEN THE STRONG CAP, IS IN QUESTION. WOULD
NOT BE SURPRISED TO SEE AN ORGANIZED COLD POOL SUPPORT DAMAGING WIND
GUSTS INTO PART OF THE AREA...ESPECIALLY NORTH CENTRAL KANSAS...BUT
IT SEEMS UNLIKELY AT THE SAME TIME.
THUNDERSTORMS WILL SHIFT NORTHEAST OF THE AREA ON SATURDAY MORNING
WITH A VERY MOIST BOUNDARY LAYER REMAINING IN PLACE. THE SUN WILL
COME OUT IN FULL FORCE AND EXPECT A VERY HOT DAY WITH HIGHS WELL
INTO THE 90S AND LOWER 100S IN SOME AREAS. WHILE SOME GUIDANCE (GFS
IN PARTICULAR) MIXES VERY DEEP, IT DOES NOT APPEAR REALISTIC AND
HAVE FORECAST CLOSER TO HOW PAST EVENTS HAVE BEHAVED...MAINTAINING A
SHALLOW LAYER OF VERY HIGH NEAR-SURFACE DEWPOINTS AND HIGH HEAT
INDICES THROUGH THE AFTERNOON. WILL NEED TO CLOSELY MONITOR THE
FORECAST, ESPECIALLY FOR DEWPOINTS AND THE BEHAVIOR OF ANY REMNANT
OUTFLOW, AS PARTS OF THE AREA MAY APPROACH THE 110 HEAT INDEX
CRITERIA FOR AN EXCESSIVE HEAT WARNING.
BY LATE IN THE AFTERNOON, EXPECT EXTREME CAPE TO DEVELOP ACROSS
NORTHERN AND EASTERN KANSAS WHILE A REMNANT OUTFLOW BOUNDARY
AND/OR WEAK SYNOPTIC FRONT SETS UP ACROSS PARTS OF THE LOCAL AREA
AND INTO SOUTHEAST NEBRASKA. A BAND OF SEASONALLY STRONG MID LEVEL
FLOW OVER THE TOP OF STRENGTHENING LOW LEVEL FLOW WILL SUPPORT
LARGE LOOPING HODOGRAPHS ACROSS NORTHERN KANSAS AND ANY STORMS
THAT DEVELOP APPEAR LIKELY TO DEVELOP SUPERCELL STRUCTURES. ANY
STORMS IN THE LATE AFTERNOON AND EARLY EVENING WILL POSE A THREAT
FOR RATHER LARGE HAIL, DAMAGING WINDS, AND A NON-ZERO TORNADO
POTENTIAL. THE MAIN QUESTION IS WHERE THOSE STORMS WILL DEVELOP
AND CURRENT SUGGESTIONS POINT TO AREAS NEAR AND NORTH OF THE NE/KS
BORDER.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 PM CDT FRI AUG 7 2015
ONGOING CONVECTION MAY LINGER THROUGH THE LATE EVENING HOURS MAINLY
FOR AREAS NORTH OF I-70. DURING THIS TIME FRAME A COLD FRONT
POSSIBLY REINFORCED BY AN OUTFLOW BOUNDARY SHOULD EXTEND FROM FAR
NORTHEAST KS TO CENTRAL KS AND GRADUALLY SLIDE SOUTHWARD OVERNIGHT.
INSTABILITY BEHIND THE FRONT APPEARS TO STILL POSE THE RISK FOR
ELEVATED STORMS, WHILE DEEP LAYER SHEAR IS FORECAST TO DECREASE
OVERALL. THE LOW TEMPERATURES SUNDAY MORNING WILL BE QUITE WARM IN
THE MID TO UPPER 70S WITH THE EXCEPTION OF FAR NORTHERN KS WHERE
PRECIP MAY COOL THINGS OFF A TOUCH. AS THAT FRONT SLIDES SOUTHWARD
THE MODELS ARE HINTING AT WEAK SHORTWAVES TRACKING OVER KS DURING
THE DAY SUNDAY. AS FOR NOW THE COVERAGE APPEARS TO BE SCATTERED DUE
TO THE WEAK LARGE SCALE FORCING. WITH POSSIBLE PRECIP AND CLOUDS
AROUND THE AREA HIGH TEMPERATURES ARE SOMEWHAT UNCERTAIN. BY SUNDAY
EVENING THE FRONT SHOULD REACH THE OK/KS STATE LINE. ALTHOUGH
ELEVATED SHOWERS AND STORMS WILL STILL BE POSSIBLE OVERNIGHT SUNDAY
ESPECIALLY SINCE THE MID/UPPER LEVEL FLOW BECOMES MORE WESTERLY
OPENING THE DOOR FOR MORE WEAK SHORTWAVES TO TRACK OVER THE REGION
WITH THE BETTER CHANCES SOUTH OF I-70. COOLER AIR WILL PUSH
SOUTHWARD ON MONDAY GIVING US HIGHS IN THE MID TO UPPER 80S. MOST OF
THE DAYTIME HOURS SHOULD BE DRY ON MONDAY ALTHOUGH A SHORTWAVE WILL
DIG ACROSS THE UPPER MIDWEST LATE MONDAY BRINGING A SECONDARY
BOUNDARY SOUTHWARD THROUGH NE. STORMS DEVELOPING ON THIS BOUNDARY
COULD GET CLOSE TO FAR NORTHERN KS.
MID WEEK TIME FRAME LOOKS TO BE QUIET WEATHER WISE AT THIS POINT.
BOTH GFS AND ECMWF ARE IN GOOD AGREEMENT EARLY IN THE PERIOD WITH
A LARGE SCALE TROUGH OVER THE WEST AND EAST COAST OF THE CONUS. IN
THE MIDDLE GROUND IS A HIGHLY AMPLIFIED RIDGE OVER THE CENTRAL
CONUS. THE DIFFERENCE COMES LATER IN THE PERIOD WHERE THE GFS DOES
SUGGEST THAT THE RIDGE AXIS WILL BECOME MORE NARROW OVER THE
CENTRAL CONUS BY LATE WEDNESDAY AS A CUT-OFF LOW MAY SET UP ALONG
THE CENTRAL CALIFORNIA COAST. THE MAIN WESTERLIES ARE FORCED
AROUND THE NORTHERN PERIPHERY OF THIS UPPER LOW WHICH COULD ALLOW
FOR A TROUGH TO DIG INTO THE NORTHERN ROCKIES WITH AN ASSOCIATED
DEEPENING LOW MOVING ALONG THE US/CANADIAN BORDER. WITHIN A
LEESIDE TROUGH SETTING UP AND THIS MID TO UPPER LEVEL TROUGH
FEATURE TO THE NORTH, A SURFACE WARM FRONT COULD EXTEND INTO THE
CENTRAL PLAINS AND CAUSE SOME SMALL CHANCES FOR PRECIP BY AROUND
FRIDAY MORNING TIME FRAME. THIS CHANCE LOOKS TO BE MINIMAL AT THIS
POINT, SO OPTED TO KEEP SLIGHT POP CHANCES IN THE FORECAST AT THIS
TIME. TEMPS ARE EXPECTED TO BE IN CHECK DURING THE UPCOMING WEEK WITH
A CANADIAN HIGH PRESSURE RIDGE INFLUENCING THE REGION, SO HIGHS
SHOULD REMAIN IN THE UPPER 80S WITH LOWS IN THE MID TO UPPER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI AUG 7 2015
THERE IS QUITE A BIT OF UNCERTAINTY IN WHERE THE MCS WILL GO
DURING THE EARLY MORNING HOURS. THE HRRR HAS BEEN CONSISTENTLY
BRINGING THE ELEVATED STORMS THROUGH EASTERN KS, ALTHOUGH IT SEEMS
TO BE DELAYING THE PROGRESS TO MORE MID MORNING. MEANWHILE THE
OPERATIONAL MODELS CONTINUE TO FOCUS THE MOST LIKELY TRACK OF THE
STORMS ACROSS SOUTHERN NEB AND FAR NORTHERN KS. WITH PROFILER DATA
SHOWING THE DECENT LOW LEVEL JET VEERING TO THE SOUTH AND
SOUTHWEST, THINK THERE IS A CHANCE FOR ELEVATED STORMS TO MOVE
INTO THE TERMINALS SO WILL INCLUDE A VCTS WITH VFR CONDITIONS AND
MONITOR TRENDS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY FROM NOON TO 9 PM CDT SATURDAY FOR KSZ010>012-
021>024-026-034>040-054>056-058-059.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM...DRAKE/SANDERS
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1018 PM MDT FRI AUG 7 2015
.UPDATE...
ISSUED AT 1018 PM MDT FRI AUG 7 2015
UPDATE SENT TO CANCEL SEVERE THUNDERSTORM WATCH FOR THE ENTIRE
AREA. SEVERE THREAT HAS SHIFTED EAST OF THE CWA...BUT DO EXPECT
SCATTERED RW/TRW TO PERSIST BUT TAPER AS THE OVERNIGHT HRS
PROGRESS. FLASH FLOOD WARNING REMAINS IN EFFECT FOR HITCHCOCK
COUNTY IN NEBRASKA. CONCERN IS FOR HEAVY RAINFALL THAT OCCURRED
JUST TO THE NORTH EARLIER THIS EVENING IN CHASE/HAYS COUNTIES...
WILL FILTER SOUTH VIA THE FRENCHMEN CREEK AND AFFECT AREAS LIKE
STRATTON...CULBERTSON.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 159 PM MDT FRI AUG 7 2015
BIGGEST CHALLENGE IN SHORT TERM IS THUNDERSTORM POTENTIAL THIS
AFTERNOON AND OVERNIGHT. NUMEROUS RUNS OF THE RAP PERSIST IN
BREAKING OUT SCATTERED AFTERNOON CONVECTION ACROSS THE CENTRAL
AND NORTHEAST COUNTIES...GENERALLY IN THE VICINITY OF A VERY WEAK
DECAYING SURFACE BOUNDARY. HAVE SOME DOUBTS ABOUT THIS LOOKING AT
CURRENT SATELLITE TRENDS AND SPC MESOANALYSIS CINH...BUT HAVE LEFT
THE SLIGHT CHANCE POPS NONETHELESS.
BIGGER ISSUE IS DEVELOPMENT OF STORMS OVER COLORADO LATER THIS
AFTERNOON AND THEIR SUBSEQUENT MOVEMENT. WATER VAPOR IMAGERY
SHOWS THE APPROACH OF THE NEXT UPSTREAM SHORTWAVE TROUGH AND RADAR
NOW SHOWS INITIAL THUNDERSTORM DEVELOPMENT SOUTH OF DENVER. MOST
GUIDANCE...INCLUDING THE CONVECTION-ALLOWING MODELS...INDICATES
BEST COVERAGE OF STORMS WILL BE ACROSS NORTHEAST COLORADO INTO
SOUTHWEST NEBRASKA...CLIPPING NORTHWEST KANSAS WITH LESSER
COVERAGE SOUTH AND EAST. ULTIMATELY IT DEPENDS ON UPSCALE
DEVELOPMENT AND WHETHER OR NOT A DECENT MCS CAN DEVELOP AND
PRODUCE STORMS FURTHER SOUTHEAST OF THE MAIN SHORTWAVE. HAVE
CONTINUED THE PREVIOUS FORECAST TREND OF BEST COVERAGE NORTH AND
NORTHWEST WITH LESSER POTENTIAL SOUTH OF I-70.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 334 PM MDT FRI AUG 7 2015
FORECAST PROBLEM WILL BE THUNDERSTORM CHANCES AND ANY HEAVY
RAINFALL THREAT. SATELLITE IS SHOWING AN AMPLIFIED AND MOSTLY
PROGRESSIVE FLOW FROM THE PACIFIC INTO NORTH AMERICA. THIS FLOW
BECOMES MORE OF A SPLIT WITH THE TROUGHS ALONG THE WEST AND EAST
COASTS. A LOT OF PACIFIC AND MONSOONAL MOISTURE IS BEING PULLED UP
INTO THE REGION. CURRENTLY A SYNOPTIC BOUNDARY REMAINS DRAPED TO
OUR SOUTH AND WEST.
AT JET LEVEL...MODELS STARTED OUT FINE. AT MID LEVELS...MODELS WERE
NOT TOO FAR APART. THE CANADIAN/UKMET/GFS LED THE PACK WITH OTHERS
NOT FAR BEHIND WITH THE SREF THE WORST. THE NAM/SREF WERE HANDLING
THE SURFACE WIND AND PRESSURE FIELD THE BEST. MODELS TENDED TO BE
A LITTLE COOL ON THE LOW LEVEL THERMAL FIELD WITH THE GFS/CANADIAN
DOING THE BEST.
SATURDAY NIGHT...TO BEGIN THE NIGHT...SURFACE BOUNDARY IS DRAPED
OVER THE FAR SOUTH AND WEST CENTRAL PORTION OF THE AREA. THIS
BOUNDARY GRADUALLY SINKS SOUTH THROUGH THE NIGHT. SHORTWAVE TROUGH
MOVES THROUGH FROM THE SOUTHWEST THROUGH THE NIGHT WITH THE BEST
LIFT BASICALLY OVER THE SOUTHWEST HALF. MAIN JET AXIS/LIFT STAYS NOT
TOO FAR TO OUR NORTH AND WEST THROUGH MOST OF THE PERIOD. LATE IN
THE NIGHT A RIGHT REAR QUADRANT GETS CLOSER TO THE NORTHWEST PORTION.
RIGHT NOW THE HIGHEST POPS LOOK TO BE IN THE SOUTHWEST HALF. PWS
REMAIN NEAR 1.5 INCHES. THAT WITH STORM MOTIONS ONLY 10 TO 15 KNOTS
ALONG THAT FLOW COMING OVER THE TOP OF THE SOUTHERN BOUNDARY WILL
MAKE MODERATE TO LOCALLY HEAVY RAINFALL POSSIBLE. ALSO POSSIBLE LATE
IN THE NIGHT WITH MOIST LOW LEVELS AND LITTLE TO NO WIND THAT PATCHY
FOG COULD DEVELOP WHERE NO PRECIPITATION IS GOING ON.
SUNDAY/SUNDAY NIGHT...IT LOOKS LIKE THERE MAY BE SOME LINGERING
RAINFALL AND PATCHY FOG IN THE MORNING. FOR THE REMAINDER OF THE
PERIOD...BOUNDARY LOOKS TO BE TO THE SOUTH AND WEST OF THE AREA WITH
A WEAK LOW LEVEL UPSLOPE REGIME IN PLACE. HOWEVER...MODELS ARE
HINTING AT A WEAK SECONDARY BOUNDARY MOVING INTO THE NORTHWEST HALF
OF THE AREA DURING THE LATE AFTERNOON INTO THE EVENING. THIS SINKS A
LITTLE FURTHER SOUTHEAST DURING THE LAST HALF OF THE NIGHT.
THE MID LEVEL FORCING THROUGH THE PERIOD REMAINS RATHER WEAK WITH
THE STRONGEST IN THE EVENING. RIGHT REAR QUADRANT OF THE JET REMAINS
NEAR THE NORTHERN AND WESTERN PORTIONS OF THE AREA THROUGH THE DAY
BUT GETS CLOSER/HAS MORE AFFECT ON THOSE LOCATIONS BY THE END OF THE
DAY. THE NORTHERN PORTION OF THE AREA KEEPS GETTING AFFECTED BY THIS
THROUGH THE MIDDLE OF THE NIGHT. WITH A VARIETY OF FORCING IN
DIFFERENT TIMES AND PLACES...WILL BROADBRUSH CHANCE POPS FOR THE
ENTIRE NIGHT.
FOR THE HIGH TEMPERATURES...WILL HAVE LOW LEVEL UPSLOPE IN PLACE
THROUGH THE DAY ALONG WITH LINGERING CLOUD COVER IN THE MORNING AND
DEVELOPING CLOUD COVER IN THE AFTERNOON WITH THE CONVECTION. MODEL
GUIDANCE HAS TENDED TO BE A LITTLE WARM.
MONDAY...JET REMAINS WELL NORTH OF THE AREA THROUGH THE DAY. MID
LEVEL SHORTWAVE RIDGE IS IN PLACE THROUGH THE DAY WITH A LOT OF
DRYING. A SHORTWAVE TROUGH STARTS GETTING CLOSER DURING THE END OF
THE DAY. AREA IS IN A POST FRONTAL AIR MASS. DEPENDING ON WHICH
MODEL YOU USE...THERE COULD BE A WEAK SUBTLE SURFACE BOUNDARY IN THE
FAR SOUTH/SOUTHWEST. SO AT THIS TIME...WILL HAVE SLIGHT TO LOW
CHANCE POPS IN THE FAR SOUTH AND SOUTHWEST PORTION OF THE AREA IN
THE AFTERNOON.
HIGH TEMPERATURES WILL BE COOLER THAN THE PREVIOUS DAY DUE TO LOWER
850 MB TEMPERATURES...UPSLOPE WINDS AND LINGERING MORNING FOG/STRATUS
THAT BEGINS SUNDAY NIGHT.
MONDAY NIGHT THROUGH SATURDAY...CONTINUED AMPLIFIED PATTERN
REMAINS IN PLACE THROUGH THE PERIOD. HOWEVER...THE DETERMINISTIC
AND ENSEMBLE OUTPUT SPREAD GETS WORSE WITH TIME...ALMOST
COMPLETELY OUT OF PHASE AT TIMES. THE DIFFERENCES INVOLVE HOW THE
PERSISTENT SOUTHERN UNITED STATES RIDGE AND WEST TROUGH EVOLVE
WITH TIME. IN GENERAL THE ECMWF REMAINS STRONGER WITH THE RIDGE.
FOR THE WESTERN TROUGH...ALL OUTPUT SUPPORTS A DEEPENING ALONG THE
COAST UPPER TROUGH.
DESPITE THOSE DIFFERENCES...THE CENTER OF THE RIDGE...STILL RATHER
FAR SOUTH...AND THE POSITION OF THE UPPER TROUGH SHOULD CONTINUE TO
ALLOW PACIFIC AND MONSOONAL MOISTURE TO PULLED UP INTO THE REGION
WITH PERIODIC SHORTWAVE TROUGHS EMBEDDED WITHIN THIS FLOW. AT THE
SURFACE...WPC GRAPHICS SHOW A PERSISTENT FRONTAL BOUNDARY STILL
DRAPED NOT TOO FAR TO OUR SOUTH AND WEST OR OVER THE AREA. THIS
KEEPS A CONTINUED UPSLOPE FLOW OVER THE AREA.
GIVEN THE BIG MODEL DIFFERENCES...THE GENERAL PATTERN SUPPORTED
CONTINUED BOUTS OF MOISTURE/LIFT/RAINFALL...AND THE PROXIMITY OF A
BOUNDARY AND UPSLOPE FLOW...SHOULD SEE A CONTINUED THREAT FOR
THUNDERSTORMS AND DO NOT FEEL COMFORTABLE MAKING ANY MAJOR
ADJUSTMENTS TO THE GUIDANCE. THE DETAILS WILL HAVE TO BE REFINED AS
WE GET CLOSER TO EACH EVENT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 546 PM MDT FRI AUG 7 2015
BOTH SITES WILL SEE VFR CONDITIONS GIVE WAY TO THUNDERSTORM
DEVELOPMENT FROM 02Z-06Z. AFT 06Z...FOG BEGINS TO DEVELOP AS
WINDS SLACKEN BY 06Z WITH 6SM DROPPING DOWN TO 1SM OR LESS WITH
CEILINGS BLW OVC010 BY 09Z...LASTING THRU 15Z ESPECIALLY FOR KMCK.
AFT THAT...VFR WITH SCATTERED CLOUD COVER. WINDS SE
15-25KTS...BECM LGT/VAR BY 06Z THEN NNE AROUND 10KTS 14Z-15Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...DLF
LONG TERM...BULLER
AVIATION...JN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1057 PM EDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1045 PM EDT SUN AUG 9 2015
A SHORTWAVE MOVING THROUGH THE OH VALLEY REGION IS BRINGING SOME
SHOWERS TO SOUTHERN OH AND NORTHERN KY. KCVG ONLY TRACED AS THESE
PASSED...SO THESE LIKELY DO NOT AMOUNT TO MUCH MORE THAN
SPRINKLES. OTHERWISE...MODELS INDICATE ADDITIONAL CONVECTION
UPSTREAM WILL MOVE EAST AND OR DEVELOP AND MOVE EAST TO EAST
SOUTHEAST AS IT WORKS AROUND THE MID LEVEL RIDGE CENTERED OVER THE
SOUTHERN PLAINS. DUE TO UNCERTAINTY IN TIMING AND MODEL
DIFFERENCES IN EVOLUTION OF CONVECTION OVERNIGHT AND INTO THE DAY
ON MONDAY...NO CHANGES WERE MADE TO POPS TOWARD DAWN. THE ONLY
CHANGES TO POPS WERE IN THE SHORT TERM TO ACCOUNT FOR THE SHOWERS
MOVING TOWARD NE KY. OTHERWISE...HOURLY GRIDS WERE FRESHENED UP
BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS.
UPDATE ISSUED AT 820 PM EDT SUN AUG 9 2015
A MID LEVEL RIDGE OF HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH A SERIES OF SHORTWAVES MOVING THROUGH OR NEARING THE
LOWER OH VALLEY AS THEY MOVE AROUND THIS RIDGE. AT THE SAME TIME...
A SERIES OF SHORTWAVE TROUGH WILL APPROACH OR MOVE THROUGH THE
GREAT LAKES. ALL OF THIS WILL BEGIN TO CARVE OUT AN EASTERN US
TROUGH WHILE THE RIDGE BUILDS NORTH INTO THE NORTHERN ROCKIES. AT
THE SFC..AN AREA OF LOW PRESSURE WILL TRACK INTO THE LOWER GREAT
LAKES WITH THE WARM FRONT LIFTING INTO THE REGION WHILE A COLD
FRONT MOVES INTO THE LOWER OH VALLEY. OVERALL...MOISTURE AND
FORCING WILL INCREASE OVERNIGHT ACROSS THE OH VALLEY REGION...BUT
CONFIDENCE REMAINS LOW IN THE EVOLUTION OF CONVECTION OVERNIGHT.
WITH RECENT MODEL GUIDANCE STILL SUPPORTING CHANCES FOR CONVECTION
LATE TONIGHT AND SOME DISAGREEMENT AS TO WHERE CHANCES MAY BE
BEST...NO CHANGES WERE MADE TO POPS AND WEATHER ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 825 PM EDT SUN AUG 9 2015
VFR IS CURRENTLY OBSERVED ACROSS THE AREA AND VFR SHOULD PERSIST
THROUGH AT LEAST 6Z. HOWEVER...WITH INCREASING MID AND HIGH LEVEL
MOISTURE...MID AND HIGH CLOUDS WILL ALSO INCREASE AND SHOULD KEEP
FOG AT BAY AT LEAST FOR THE TAF SITES. A SERIES OF SHORTWAVE
TROUGHS AND AN APPROACHING COLD FRONT WILL BRING A THREAT FOR
A SEMI- ORGANIZED CLUSTER OF SHOWERS AND STORMS TO MOVE INTO CWA
PARTICULARLY THE NORTH AROUND 9Z...AND THEN TRANSLATE SOUTH AND
EAST. A TEMPO GROUP WITH CIGS AND VIS INTO THE IFR TO MVFR RANGE
WITH THE CONVECTION WAS CONTINUED TO BE USED AT SYM...JKL AND SJS.
ADDITIONAL STORMS WILL BE POSSIBLE THROUGH THE REST OF THE
DAY...PARTICULARLY AFTER 16Z TO 18Z...WHEN ANOTHER TEMPO GROUP WAS
USED. OUTSIDE OF THESE TIMES PREVAILING VFR WITH VCTS WAS USED.
THUNDERSTORM WIND GUSTS COULD REACH 25 KT OR HIGHER...ALTHOUGH
OUTSIDE OF STORMS WINDS SHOULD AVERAGE 10 KT OR LESS THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
833 PM EDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 820 PM EDT SUN AUG 9 2015
A MID LEVEL RIDGE OF HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH A SERIES OF SHORTWAVES MOVING THROUGH OR NEARING THE
LOWER OH VALLEY AS THEY MOVE AROUND THIS RIDGE. AT THE SAME TIME...
A SERIES OF SHORTWAVE TROUGH WILL APPROACH OR MOVE THROUGH THE
GREAT LAKES. ALL OF THIS WILL BEGIN TO CARVE OUT AN EASTERN US
TROUGH WHILE THE RIDGE BUILDS NORTH INTO THE NORTHERN ROCKIES. AT
THE SFC..AN AREA OF LOW PRESSURE WILL TRACK INTO THE LOWER GREAT
LAKES WITH THE WARM FRONT LIFTING INTO THE REGION WHILE A COLD
FRONT MOVES INTO THE LOWER OH VALLEY. OVERALL...MOISTURE AND
FORCING WILL INCREASE OVERNIGHT ACROSS THE OH VALLEY REGION...BUT
CONFIDENCE REMAINS LOW IN THE EVOLUTION OF CONVECTION OVERNIGHT.
WITH RECENT MODEL GUIDANCE STILL SUPPORTING CHANCES FOR CONVECTION
LATE TONIGHT AND SOME DISAGREEMENT AS TO WHERE CHANCES MAY BE
BEST...NO CHANGES WERE MADE TO POPS AND WEATHER ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 825 PM EDT SUN AUG 9 2015
VFR IS CURRENTLY OBSERVED ACROSS THE AREA AND VFR SHOULD PERSIST
THROUGH AT LEAST 6Z. HOWEVER...WITH INCREASING MID AND HIGH LEVEL
MOISTURE...MID AND HIGH CLOUDS WILL ALSO INCREASE AND SHOULD KEEP
FOG AT BAY AT LEAST FOR THE TAF SITES. A SERIES OF SHORTWAVE
TROUGHS AND AN APPROACHING COLD FRONT WILL BRING A THREAT FOR
A SEMI- ORGANIZED CLUSTER OF SHOWERS AND STORMS TO MOVE INTO CWA
PARTICULARLY THE NORTH AROUND 9Z...AND THEN TRANSLATE SOUTH AND
EAST. A TEMPO GROUP WITH CIGS AND VIS INTO THE IFR TO MVFR RANGE
WITH THE CONVECTION WAS CONTINUED TO BE USED AT SYM...JKL AND SJS.
ADDITIONAL STORMS WILL BE POSSIBLE THROUGH THE REST OF THE
DAY...PARTICULARLY AFTER 16Z TO 18Z...WHEN ANOTHER TEMPO GROUP WAS
USED. OUTSIDE OF THESE TIMES PREVAILING VFR WITH VCTS WAS USED.
THUNDERSTORM WIND GUSTS COULD REACH 25 KT OR HIGHER...ALTHOUGH
OUTSIDE OF STORMS WINDS SHOULD AVERAGE 10 KT OR LESS THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1052 PM EDT SUN AUG 9 2015
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 326 PM EDT SUN AUG 9 2015
SHOWERS AND THUNDERSTORMS CHANCES WILL INCREASE TONIGHT INTO MONDAY.
MANY AREAS SHOULD SEE AROUND A HALF INCH OF RAIN IN THIS PERIOD...
HOWEVER SEVERE WEATHER IS GENERALLY NOT EXPECTED. A FEW SHOWERS MAY
LINGER INTO MONDAY EVENING...BUT WE SHOULD GRADUALLY DRY OUT...
MAKING FOR A PLEASANT TUESDAY WITH LESS HUMIDITY.
MUCH OF THE REMAINDER OF THE WEEK LOOKS DRY WITH NEAR OR SLIGHTLY
ABOVE NORMAL TEMPERATURES...WITH DAYTIME HIGHS GENERALLY 80 TO 85.
A WIDELY SCATTERED THUNDERSTORM WILL BE POSSIBLE ON THURSDAY.
&&
.UPDATE...
ISSUED AT 1050 PM EDT SUN AUG 9 2015
I HAVE UPDATED THE FORECAST TO INCREASE THE RISK FOR THUNDERSTORMS
TOWARD MORNING OVER OUR SOUTHWEST CWA THEN SPREAD THAT CONVECTION
EASTWARD. WE ALREADY HAD LIKELY POP FOR MONDAY MORNING AFTER 8
AM...SO THIS JUST STARTS THE CONVECTION A TOUCH SOONER.
WHAT I AM SEEING FROM BOTH THE WATER VAPOR IMAGE LOOPS AND
WATCHING THE RAP MODEL HOURLY IS THAT WE HAVE A JET EXIT REGION
WITH DECENT PVU (POTENTIAL VORTICITY) IN THE 500 TO 300 MB LAYER
COMING THROUGH THE I-94 TO I-96 AREA BETWEEN 4 AM AND 9 AM THIS
MORNING. A WEAK LLJ DEVELOPS IN RESPONSE TO THIS AIMED AT AZO
BTW 8 AM AND 10 AM. SINCE THE HRRR...HRRR EXPERIMENTAL...AND
RAP13 HAVE BEEN RATHER CONSISTENT WITH THIS AND IT MAKES SENSE
GIVEN WHAT IS GOING ON NOW... I AM DID UPDATE THE GRIDS TO REFLECT
THE IDEA OF THUNDERSTORMS TOWARD MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 326 PM EDT SUN AUG 9 2015
RAIN CHANCES OVER SW MI WILL PEAK DURING THE FIRST HALF OF MONDAY AS
A COLD FRONT APPROACHES. GIVEN THE FRONT/S TIMING SEVERE WEATHER IS
GENERALLY NOT EXPECTED. WE DRY OUT MONDAY EVENING...BECOMING COOLER
AND LESS HUMID INTO TUESDAY.
A COLD FRONT WAS MOVING ACROSS THE MN/WI BORDER THIS AFTERNOON AND
HAS AN AREA OF SHOWERS AND STORMS WITH IT. THE STRONGEST AREA OF
STORMS WAS ASSOCIATED WITH THE LEFT EXIT REGION OF THE UPPER JET.
THE FRONT AND THE UPPER JET WILL MAKE IT/S WAY THROUGH THE CWA
MONDAY MORNING INTO EARLY AFTERNOON...NORMALLY A MIN TIME FOR SEVERE
WX. THIS LIKELY FAVORS AREAS TO OUR EAST FOR THE POTENTIAL OF
STRONGER STORMS. THE OTHER PARAMETER GOING AGAINST SEVERE STORMS IS
THAT THE 0-6 KM BULK SHEAR IS ONLY 20-25 KNOTS OVER SW MI AS THE
FRONT COMES THROUGH.
HOWEVER THE FRONT WILL BE HEADING INTO A JUICY AIR MASS WITH DEW
POINTS AROUND 70 ALONG I-94...AND MID TO UPPER 60S ELSEWHERE ACROSS
THE CWA. SO EXPECT THE STORMS OVER MN/WI TO HOLD TOGETHER AND
EXPAND...BRINGING A BENEFICIAL RAIN TO MOST OF THE CWA LATE TONIGHT
INTO MONDAY. RAIN TOTALS WILL VARY GREATLY GIVEN THE CONVECTIVE
NATURE...BUT MOST AREAS SHOULD SEE A HALF TO THREE QUARTERS OF INCH
OF RAIN. THE SHOWERS AND STORMS WILL END FROM WEST TO EAST WITH THE
FRONTAL PASSAGE MONDAY AFTERNOON INTO THE EVENING.
COOLER AND LESS HUMID AIR WILL FILTER IN BEHIND THE FRONT. HIGHS IN
THE 70S CAN BE EXPECTED FOR TUESDAY AS THE UPPER FLOW BECOMES
NORTHWESTERLY. OUTSIDE CHANCE THAT A FEW SHOWERS MAY POP UP ACROSS
CENTRAL LOWER TUESDAY DUE TO THE COOL AIR ALOFT. I DID NOT ADD
THIS...BUT I DID INCREASE THE CLOUD COVER IN THE FORECAST. WE
SHOULD SEE DIURNAL CU AT THE VERY LEAST...WHICH SHOULD BECOME BKN TO
OVC AT TIMES DURING THE AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 326 PM EDT SUN AUG 9 2015
FAIR WEATHER IS ANTICIPATED WEDNESDAY WITH A HIGH PRESSURE RIDGE
CENTERED OVER THE LOWER GREAT LAKES REGION STILL IN CONTROL OF THE
WX PATTERN.
IT WILL TURN WARMER AND MORE HUMID THURSDAY IN SW FLOW OUT AHEAD OF
AN APPROACHING COLD FRONT. THE COLD FRONT WILL BRING A CHANCE OF
RAIN AND THUNDERSTORMS LATE THURSDAY THROUGH THURSDAY NIGHT INTO
FRIDAY.
FAIR WX WILL RETURN BEHIND THAT SYSTEM FOR FRIDAY NIGHT THROUGH THE
WEEKEND AS A HIGH PRESSURE RIDGE BUILDS SLOWLY EAST ACROSS THE GREAT
LAKES REGION. TEMPERATURES NEXT WEEKEND WILL AVERAGE NEAR TO
SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 738 PM EDT SUN AUG 9 2015
A FEW SHOWERS AND ISOLATED THUNDERSTORMS ARE POSSIBLE THIS
EVENING. WITH THE WARM FRONT NEAR I-75 AT 21Z... IT WOULD SEEM
THE JXN AND LAN TAF SITES HAVE THE GREATEST RISK OF THUNDERSTORMS
EARLY THIS EVENING SO I PUT VCTS THERE. THAT CONVECTION AREA SHOULD
BE EAST OF THE TAF SITES AFTER 02Z. I EXPECT JUST A VFR CIGS
ACROSS THE AREA FROM THEN TILL AROUND 09Z OR SO. THE SOUTHERLY
FLOW OF MOIST AIR INTO THE AREA COMBINED WITH NIGHT TIME COOLING
WILL LEAD TO A LOW STRATUS DECK TOWARD MORNING BUT NOT MUCH IN THE
WAY OF SHOWERS. THE FRONTAL CONVECTIVE BAND...BASED ON THE HRRR-CR
FALLS APART OVERNIGHT BUT RE-FIRES AROUND 13-14Z NEAR THE LAKE
MICHIGAN SHORE THAN MOVES EAST ACROSS THE CWA WITH THE COLD FRONT.
SKIES SHOULD CLEAR LATE IN THE AFTERNOON AS DRY AIR BEHIND THE
COLD FRONT REACHES THE AREA.
&&
.MARINE...
ISSUED AT 326 PM EDT SUN AUG 9 2015
RATHER QUIET CONDITIONS ARE EXPECTED ON THE TONIGHT INTO MONDAY.
HOWEVER NORTHERLY WINDS WILL INCREASE BEHIND THE FRONT AND WAVES
WILL BEGIN TO BUILD MONDAY EVENING INTO TUESDAY. PEAK WINDS AND
WAVES SHOULD OCCUR INTO TUESDAY...AND WE MAY NEED A SMALL CRAFT
ADVISORY BY TUESDAY AFTERNOON. WINDS AND WAVES SHOULD THEN DIMINISH
LATE TUESDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 PM EDT SUN AUG 9 2015
NO HYDRO IMPACTS ARE EXPECTED OVER THE NEXT WEEK. THE CHANCE FOR
SCATTERED SHOWERS WILL INCREASE THROUGH THE AFTERNOON AND ESPECIALLY
THE EVENING. RAIN CHANCES ARE HIGHEST THIS EVENING INTO MONDAY
AFTERNOON ALONG WITH THE POTENTIAL FOR ISOLATED STORMS. STORM
CHANCES WILL BE HIGHEST EARLY MONDAY AFTERNOON ACROSS THE EASTERN
FORECAST AREA. WE COULD SEE A FEW STRONG STORMS AT THAT TIME CAPABLE
OF LOCALLY HIGHER RAINFALL AMOUNTS. BUT IN GENERAL...WIDESPREAD
RAINFALL IS FORECAST TO REMAIN BELOW 0.75 INCHES AND MOST LIKELY IN
THE 0.25 TO 0.50 INCH RANGE. ANY RAINFALL TONIGHT INTO MONDAY WILL
LIKELY BE BENEFICIAL FOR MOST.
OUTLOOK...THE REST OF THE WORK WEEK LOOKS QUIET AND MAINLY DRY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...LAURENS
AVIATION...WDM
HYDROLOGY...EBW
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
746 PM EDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN AUG 9 2015
A NW FLOW BTWN AN UPR RDG IN THE PLAINS AND A DOWNSTREAM TROF OVER
ERN CANADA WL DOMINATE THE GREAT LKS EARLY THIS WEEK...BRINGING A
PERIOD OF BLO NORMAL TEMPS FOR MON NGT INTO WED. WARMER WX AND A CHC
OF SHOWERS/TS WL THEN BE THE RULE ON THU IN ADVANCE OF A COLD FNT
ASSOCIATED WITH A DISTURBANCE DROPPING SEWD THRU NW ONTARIO. EXPECT
DRY AND A BIT COOLER WX LATE IN THE WEEK WITH HI PRES TRAILING THE
FNT. THE NEXT CHC OF SHOWERS/TS AND WARMER WX WL RETURN NEXT SUN
AHEAD OF THE NEXT SHRTWV/COLD FNT TOPPING THE PERSISTENT UPR RDG IN
THE PLAINS.
MON NGT...SHRTWV DIVING SEWD IN THE NW FLOW ALF BTWN PLAINS RDG AND
ERN TROF IS FCST TO DIG THRU THE AREA. SOME OF THE MODELS SHOW SOME
WEAK DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE PVA AHEAD OF THIS
DISTURBANCE AND GENERATE SOME SPOTTY LGT PCPN OVER THE AREA...MAINLY
OVER THE HIER TERRAIN NEAR LK SUP WITH UPSLOPE N WINDS. BUT ABSENCE
OF STRONGER FORCING AND ARRIVAL OF THIS DISTURBANCE DURING PERIOD OF
NOCTURNAL COOLING WL LIMIT INTENSITY AND COVERAGE OF ANY SHOWERS. DO
EXPECT MORE LO CLDS IN THESE UPSLOPE AREAS WITH AN INCRS IN LLVL RH
AS H85 TEMPS WITHIN THERMAL TROF FALL TO 8-10C BY 12Z TUE. STEADY N
WINDS WL LIMIT THE DIURNAL TEMP FALL DESPITE THE LLVL COOLING TREND.
MOST PLACES SHOULD SEE MINS IN THE 50S...WITH THE LOWER TEMPS AT THE
COOLER SPOTS OVER THE INTERIOR W HALF WHERE THE WINDS WL BE A BIT
LIGHTER CLOSER TO SFC HI PRES RDG BLDG INTO MN.
TUE/TUE NGT...EXPECT DRY WX TO PREVAIL DURING THIS TIME UNDER
CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR DVGC/SUBSIDENCE LEFT IN THE
WAKE OF EXITING SHRTWV. SC IN THE UPSLOPE AREAS ON TUE MRNG SHOULD
EXPAND WITH DAYTIME HEATING UNDER THERMAL TROF...BUT CLOSER APRCH OF
SFC HI PRES FCST TO ARRIVE OVER THE W BY 00Z WED/INCRSGLY ACYC LLVL
FLOW/LOWERING SUBSIDENCE INVRN WL LIKELY RESULT IN MORE SUNSHINE W-E
THRU THE AFTN. UNDER MOCLR SKIES...TUE NGT WL BE COOL ESPECIALLY
OVER THE INTERIOR W HALF WITH LIGHTER WINDS CLOSER TO SFC HI PRES
RDG SINKING INTO WI. BUT WITH MIN PWAT NOT MUCH BLO 0.75 INCH IN
THIS AREA...DO NOT EXPECT MIN TEMPS TO BE TOO CHILLY.
WED/WED NGT...SFC HI PRES IS FCST TO SINK S INTO THE MID MS RIVER
VALLEY THRU THIS TIME. AS THE MSLP FALLS OVER NW ONTARIO IN ADVANCE
OF SHRTWV RIDING OVER THE TOP OF PLAINS RDG INTO FAR NW ONTARIO...
UPR MI WL BE DOMINATED BY AN INCRSG WSW FLOW. EXPECT SOME CLDS
ASSOCIATED WITH BAND OF INCRSG WAA/ISENTROPIC ASCENT BEST SHOWN ON
THE 300-305K SFCS TO IMPACT THE UPR LKS WED AFTN/EVNG. MANY OF THE
MODELS GENERATE SOME PCPN AS WELL...BUT RELATIVE DRYNESS OF THE
LLVLS AND MODEST PWAT FCST NEAR 1 INCH /ABOUT NORMAL/ WARRANT ONLY
LO CHC POPS.
THU/THU NGT...SHRTWV OVER FAR NW ONTARIO AT 12Z THU IS PROGGED TO
SLIDE SE INTO WRN QUEBEC THU NGT AND DRAG A COLD FNT ACRS UPR MI
SOMETIME THU AFTN/EVNG. ARRIVAL OF THIS BNDRY/BAND OF MODEST DEEP
LYR FORCING AT A TIME WHEN DAYTIME HEATING WL HAVE AN IMPACT FAVORS
SOME SHOWERS/TS...BUT ABSENCE OF MUCH IN THE WAY OF HGT FALLS WELL
TO THE SW OF TRACK OF SHRTWV/SHARPEST FORCING...QUESTIONS ABOUT
DEGREE OF MSTR INFLOW AHEAD OF THE FNT AND TIMING DIFFERENCES AMONG
THE MODELS ON FROPA TIMING WARRANT NO HIER THAN LO CHC POPS ATTM.
THU LOOKS TO BE A WARM DAY WITH H85 TEMPS PUSHING 18-20C AHEAD OF
THE FNT.
EXTENDED...HI PRES TRAILING THE COLD FROPA WL BRING MOCLR WX FOR FRI
AND SAT. FRI WL BE COOLER WITH H85 TEMPS DIPPING TO ARND 14C...BUT
THEN SAT WL TURN WARMER AS THE HI SHIFTS TO THE E AND RETURN SSW
FLOW LIFTS H85 TEMPS UP TO 16C. THE NEXT CHC OF SHOWERS/TS WL ARRIVE
ON SUN AHEAD OF NEXT DISTURBANCE RIDING OVER THE PLAINS RDG.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 746 PM EDT SUN AUG 9 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN THIS EVENING MAY STILL BRUSH
KSAW BUT CONFIDENCE IN TSRA POTENTIAL WAS TOO LOW TO MENTION IN THE
TAF. OTHERWISE...ONLY A FEW LINGERING LIGHT SHOWERS ARE POSSIBLE
EARLY IN THE PERIOD AT CMX/IWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA TONIGHT AND BREAKS IN THE
CLOUDS OCCUR...EXPECT GROUND FOG MAY DEVELOP AT ALL THREE
SITES...ESPECIALLY AT SAW WHERE RAIN FELL AND THE LIGHTEST WINDS ARE
WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST SITES...AS
LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE NIGHT AND LEAD
TO MORE MIXING INTO THE DRIER AIR ALOFT. FINALLY FOR
TOMORROW...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE MONDAY AFTERNOON AND EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM EDT SAT AUG 8 2015
THE UPPER GREAT LAKES REGION WILL BE BETWEEN UPPER LEVEL FEATURES
OVER THE NEXT 24 HOURS...LEADING TO SOME UNCERTAINTY IN THE COVERAGE
AND AMOUNT OF PRECIPITATION THAT WILL OCCUR AHEAD OF THE COLD FRONT
TONIGHT. THE MAIN SHORTWAVE IS CURRENTLY LOCATED JUST TO THE EAST OF
LAKE WINNIPEG AND HAS A 1002MB SURFACE LOW LOCATED WITH IT. A COLD
FRONT STRETCHES SOUTH-SOUTHEAST FROM THIS LOW AND INTO NORTHERN
MINNESOTA (CURRENTLY FROM THE LAKE OF THE WOODS TO JUST TO THE EAST
OF FARGO). HAVE SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AROUND
PARK RAPIDS MINNESOTA A COUPLE HOURS AGO AND THEY HAVE BEEN MAKING
THERE WAY TO THE EAST TOWARDS LEECH LAKE AHEAD OF THAT FRONT AND IN
THE RIBBON OF DEEPER MOISTURE FROM 925-700MB AHEAD OF THE ASSOCIATED
TROUGH. OVER THE U.P....THE ABUNDANT DRY AIR SEEN ABOVE 700MB ON THE
12Z KGRB SOUNDING AND ON RAP ANALYSIS DATA...ASSOCIATED WITH THE
SURFACE RIDGE FROM A HIGH NEAR JAMES BAY...HAS BEEN LIMITING THE
EASTWARD EXTENT OF THE OF SHOWERS AS THEY MOVE INTO WESTERN LAKE
SUPERIOR. BUT WITH THE MOISTURE BELOW 700MB...HAVE SEEN DIURNAL CU
FILL IN THE GAPS FROM EARLIER TODAY BETWEEN THE SOUTHEASTERLY FLOW
UPSLOPE FOG AND LOW CLOUDS. TEMPERATURES HAVE WARMED INTO THE 70S
ACROSS THE AREA...WITH THE WARMEST VALUES OVER THE EAST WITH MORE
SUNSHINE. FINALLY FARTHER TO THE SOUTH...A SHORTWAVE ROUNDING THE
UPPER RIDGE OVER TEXAS/OKLAHOMA LED TO AN MCS MOVING THROUGH
NORTHEAST KANSAS AND SOUTHWEST MISSOURI EARLY THIS MORNING AND IT
HAS SINCE DISSIPATED. BUT WITH ANOTHER WAVE ROUNDING THE RIDGE
THROUGH NEBRASKA...WOULD EXPECT REDEVELOPMENT TO THE EAST OF THAT
AREA OVER THE NEXT COUPLE OF HOURS.
WITH THE SOUTHERN SHORTWAVE STAYING WELL TO THE SOUTH OF THE
AREA...THE MAIN FOCUS WILL BE WITH THE UPPER LOW NEAR LAKE WINNIPEG
SLOWLY WEAKENING AS IT MOVES EAST TOWARDS JAMES BAY. THIS WILL LEAD
TO THE SURFACE LOW FOLLOWING SUIT AND SLOWLY DRAGGING THE COLD FRONT
EAST ACROSS THE CWA. HAVE ALREADY SEEN SHOWERS/THUNDERSTORMS DEVELOP
IN NORTHERN MINNESOTA AHEAD OF THE FRONT AND WITH THE STORM MOTION
VALUES INDICATING EASTWARD MOVEMENT UP TO 30KTS...WOULD EXPECT THE
SHOWERS TO SPREAD EAST INTO WESTERN LAKE SUPERIOR AND EVENTUALLY THE
WESTERN U.P. TONIGHT. LIKE LAST NIGHT AND TODAY...THEY WILL BE
BATTLING THE EXISTING DRY MID LEVEL AIR AS THEY MOVE OUT AHEAD OF
THE SLOW MOVING SURFACE-850MB TROUGH...SO WOULD EXPECT SOME
DIMINISHMENT AS THEY HEAD TO THE EAST AND INTO THE CWA TONIGHT.
WOULD EXPECT SOME MARGINALLY SEVERE STORMS TO MOVE INTO WESTERN LAKE
SUPERIOR BEFORE THE DRY AIR AND LOSS OF DIURNAL HEATING STARTS TO
TAKE ITS TOLL. OVER THE CENTRAL AND EASTERN U.P....AM EXPECTED SOME
PATCHY GROUND FOG TO DEVELOP TONIGHT. THICKNESS WILL DEPEND ON THE
AMOUNT OF DECOUPLING THAT OCCURS TONIGHT. HAVE SHOWN THE THICKEST
FOG (AREAS COVERAGE) OVER THE CENTRAL U.P. FOR SOUTHERN
MARQUETTE...DICKINSON...DELTA...AND NORTHERN MENOMINEE COUNTIES.
WITH THE COLD FRONT STILL OFF TO THE WEST OF THE U.P. ON SUNDAY
MORNING...EXPECT THERE TO BE TIME FOR DIURNAL HEATING TO INCREASE
THE POTENTIAL FOR SHOWERS/THUNDERSTORMS OVER THE WEST/CENTRAL U.P.
DURING THE AFTERNOON. MODELS HAVE A VARIETY OF IDEAS ON ML CAPE
VALUES...RANGING FROM 250-2000 J/KG TOMORROW AFTERNOON JUST AHEAD OF
THE FRONT. LOOKING AT MODIFIED SOUNDINGS AND MEAN ML CAPE VALUES
FROM THE NCAR ENSEMBLES AND SREF...FEEL THAT VALUES AROUND 500-750
J/KG ARE A FAIRLY REASONABLE EXPECTATION AT THIS POINT. WITH 0-6KM
BULK SHEAR VALUES GENERALLY AROUND 25-30KTS...THERE IS THE POTENTIAL
FOR AN ISOLATED STRONGER STORM TOMORROW AFTERNOON. THAT MATCHES THE
IDEA FROM UPDRAFT VELOCITY/HELICITY FROM THE CAM/S AND CAM
ENSEMBLES. WITH WET BULB ZERO VALUES NEARING 10KFT AND FREEZING
LEVEL ABOVE 12KFT...THINK THAT WILL COMBINE WITH THE MARGINAL SHEAR
TO KEEP THE HAIL THREAT BORDERLINE. LIKED THE PREVIOUS SHIFTS
HANDLING OF THE DEVELOPMENT OF THE SHOWERS/THUNDERSTORMS ACROSS THE
CENTRAL U.P. (RAMPING UP TO LOCALIZED LIKELY VALUES OVER MARQUETTE
COUNTY) AND HAVE ONLY MADE MINOR ADJUSTMENTS BASED OFF LATEST MODEL
TRENDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM EDT SAT AUG 8 2015
AFTER ANY LINGERING SHOWERS END ON MON FOLLOWING A SUN NGT COLD
FROPA...THE NW FLOW BTWN A BLDG UPR RDG IN THE PLAINS AND AN
AMPLIFYING TROF OVER ERN NAMERICA WL BE THE DOMINATING INFLUENCE ON
UPR MI WX EARLY IN THE WEEK. THE RESULT WL BE A RETURN OF DRY AND
COOLER WX FOR THE MOST PART MON INTO WED. THE NEXT CHC OF SHOWERS/TS
WL ARRIVE WITH WARMER AIR WED NGT THRU THU NGT AHEAD OF A SHRTWV
MOVING OVER THE TOP OF THE RDG/THRU NW ONTARIO AND ITS ATTENDANT
COLD FNT. HI PRES TRAILING THIS COLD FNT SHOULD BRING A SEASONABLE
AIRMASS/DRIER WX LATE IN THE WEEK.
SUN NGT...SHRTWV DRIFTING ESEWD THRU FAR NORTHERN ONTARIO WL REACH
NEAR JAMES BAY BY 12Z MON AND DRAG ATTENDANT COLD FNT SLOWLY THRU
THE UPR LKS. SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE
ONTARIO SHRTWV WL BE REMAIN TO THE N AND H85 THETA E ADVECTION/
DEEPER MSTR INFLOW WL BE WEAK AT BEST...EXPECT NO MORE THAN A CHC OF
SHOWERS/TS. THE BEST CHC FOR THIS PCPN WL BE IN THE EVNG OVER
CENTRAL UPR MI...WHERE AXIS OF SOMEWHAT HIER H85 THETA E WL BE
PRESENT AT TIME WHEN DAYTIME HEATING WL STILL BE A FACTOR. THE
MAJORITY OF THE MODELS SHOW A TRAILING SHRTWV/AREA OF HIER MID LVL
MSTR/SOME DPVA AND H7-3 QVECTOR CNVGC APRCHG FM CENTRAL MN FOLLOWING
THE COLD FROPA. HOWEVER...NOCTURNAL COOLING AND LLVL DRYING/
NEGATIVE H85 THETA E ADVCTN WL LIMIT THE COVERAGE/INTENSITY OF ANY
SHOWERS THAT MIGHT ACCOMPANYING THIS HIER LVL FORCING. EXPECT THE
LOWEST MIN TEMPS OVER THE W...WHERE H85 TEMPS ARE FCST TO FALL TO
ARND 11C BY DAYBREAK.
MON...EXPECT ANY LINGERING SHOWERS OVER THE E AND SCENTRAL TO
DIMINISH WITH ARRIVAL OF DEEP DRYING/INCRSG LLVL ACYC NNW FLOW AHEAD
OF CNDN HI PRES BLDG INTO MANITOBA. LINGERING MID CLDS WL GIVE WAY
TO SOME DIURNAL CU/SC IN THE AFTN. EXPECT HI TEMPS MAINLY IN THE 70S
TO NEAR 80 OVER THE SCNTRL WITH H85 TEMPS IN THE 12-14C RANGE.
LOCATIONS NEAR LK SUP WL BE COOLEST WITH A NW FLOW OFF THE WATER.
MON NGT THRU TUE NGT...ARRIVAL OF MORE VIGOROUS DEEP LYR QVECTOR
DVGC/SUBSIDENCE UNDER CONFLUENT NW FLOW ALOFT BTWN PLAINS RDG/ERN
TROF AND H85 TEMPS FALLING AS LO AS 8 TO 10C IN THE LLVL NLY FLOW
AHEAD OF CNDN HI PRES BLDG TOWARD THE UPR LKS WL RESULT IN A PERIOD
OF COOLER AND DRIER WX FOR THE CWA. SOME OF THE MODELS HAVE BEEN
GENERATING SOME LGT PCPN MAINLY DURING DAYTIME HEATING ON TUE
ACCOMPANYING THE PASSAGE OF A SHRTWV IN THE NW FLOW. BUT ABSENCE OF
ANY MSTR INFLOW...LARGER SCALE NEGATIVE DYNAMIC FORCING/SUBSIDENCE
THAT WL MAINTAIN MID LVL CAPPING SHOWN ON THE GFS FCST SDNGS AS WELL
AS DIFFLUENT LLVL FLOW WARRANTS MAINTAINING GOING DRY FCST FOR NOW.
BUT THERE WL BE A GOOD DEAL OF DIURNAL CU ON TUE UNDER INCOMING H85
THERMAL TROF. EXPECT LO TEMPS ON TUE NGT TO FALL INTO THE 40S AT THE
COOLER INTERIOR LOCATIONS WITH MOCLR SKIES/LIGHT WINDS AS THE SFC HI
PRES MOVES OVHD.
WED...AS THE HI CENTER DRIFTS TO THE S...THE LLVL FLOW WL TURN TO
THE WSW. THE WARMING RELATED TO SOME WAA AND CONTINUED SUBSIDENCE
UNDER THE SLOWLY EXPANDING PLAINS RDG/RISING HGTS IS FCST TO BOOST
H85 TEMPS TO ARND 16C OVER THE W LATE IN THE DAY. EXPECT A WARMER
DAY THAN ON TUE...WITH HI TEMPS AT LEAST APRCHG 80 ESPECIALLY OVER
THE W AWAY FM LK MODERATION...EVEN IF SOME WAA CLDS SPILL OVER THE
CWA IN THE AFTN.
WED NGT THRU THU NGT...ALTHOUGH THERE ARE SOME DIFFERENCES IN THE
DETAILS AS EXPECTED SO FAR INTO THE FUTURE...THE LONGER RANGE
GUIDANCE INDICATES A SHRTWV RIDING OVER THE PLAINS RDG WL DROP SEWD
THRU NW ONTARIO ON THU/THU NGT AND DRAG A COLD FNT THRU THE UPR LKS
ON THU NGT. SOME OF THE MODELS GENERATE SOME LGT PCPN AS EARLY AS
WED NGT IN THE WSW FLOW/WAA BTWN THE RETREATING HI PRES TO THE S AND
FALLING MSLP OVER SCENTRAL CANADA AHEAD OF THE SHRTWV. BUT LINGERING
LLVL ACYC FLOW AND RELATIVE DRYNESS OF AIRMASS INDICATE ANY SHOWERS
WL BE WIDELY SCT AT BEST. A BETTER CHC FOR SHOWERS/TS APPEARS WL
COME LATE THU/THU EVNG WITH THE ARRIVAL OF SOME DEEP LYR QVECTOR
CNVGC ASSOCIATED WITH THE ONTARIO SHRTWV AND AHEAD OF APRCHG COLD
FNT DURING PERIOD OF DAYTIME HEATING. THE 12Z GFS IS MOST VIGOROUS
WITH THIS DISTURBANCE AND INDICATES THE POTENTIAL FOR SOME SVR
STORMS WITH MUCAPE FCST AS HI AS 2500 J/KG AND DEEP LYR SHEAR UP TO
40 KTS. THE 12Z ECMWF/CNDN MODELS SHOW A LESS IMPRESSIVE SCENARIO
WITH WEAKER MSTR RETURN. GIVEN MODEL DIFFERENCES AND UNCERTAINTY ON
THE DEGREE OF MSTR RETURN WITH SHARPEST FORCING REMAINING TO THE
NE...CONSENSUS LO CHC POPS AT THIS POINT SEEM REASONABLE. THU LOOKS
TO BE THE WARMEST DAY OF THE WEEK UNDER THERMAL RDG/H85 TEMPS UP TO
18-20C AHEAD OF INCOMING COLD FNT.
FRI/SAT...HI PRES TRAILING THE SHRTWV SHOULD BRING DRY AND SOMEWHAT
COOLER WX AT LEAST ON FRI/FRI NGT. THERE IS SOME UNCERTAINTY ON HOW
QUICKLY WAA SHOWERS/TS RETURN BTWN THE RETREATING HI AND ANOTHER
SHRTWV RIDING OVER THE PLAINS RDG LATER ON SAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 150 PM EDT SAT AUG 8 2015
VFR DIURNAL CLOUDS WILL BE THE MAIN SHORT TERM CONCERN. THESE
CEILINGS HAVE BEEN GRADUALLY RISING WITH DAYTIME HEATING AND MIXING
AND EXPECT THAT TO CONTINUE INTO THE AFTERNOON AND THE HIGH END
MVFR CEILINGS SHOULD TRANSITION TO VFR WITHIN THE NEXT COUPLE
HOURS. OTHERWISE...A COLD FRONT FROM MINNESOTA THAT WILL MOVE
ACROSS THE AREA ON SUNDAY MAY PUSH A COUPLE SHOWERS THROUGH THE
WESTERN HALF OF UPPER MICHIGAN AND ONLY HAD ENOUGH CONFIDENCE TO
INCLUDE VCSH AT KCMX OVERNIGHT AND LATE IN THE PERIOD AT KSAW. ALSO
FOR KSAW...DEPENDING ON THE AMOUNT OF SCATTERING OF THE CLOUDS THIS
EVENING...COULD SEE LIFR-IFR CONDITIONS DEVELOP WITH PATCHY GROUND
FOG OVERNIGHT TONIGHT. HAVE WENT WITH LOW END MVFR VISIBILITIES FOR
NOW...BUT WILL BE SOMETHING TO MONITOR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 250 PM EDT SAT AUG 8 2015
A LOW MOVING FROM JUST EAST OF LAKE WINNIPEG TO JAMES BAY THIS
WEEKEND WILL SWEEP A SURFACE TROUGH ACROSS LAKE SUPERIOR ON
SUNDAY...LEADING TO A SHIFT IN THE WINDS FROM A LIGHT SOUTH TO
SOUTHEASTERLY DIRECTION TO THE NORTHWEST BY MONDAY. WITH A
GENERALLY LIGHT PRESSURE GRADIENT IN PLACE...EXPECT WINDS TO STAY
BELOW 20KTS THROUGH THE PERIOD...ESPECIALLY AFTER TUESDAY WHEN HIGH
PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THE MIDDLE OF
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
250 PM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM EDT SAT AUG 8 2015
THE UPPER GREAT LAKES REGION WILL BE BETWEEN UPPER LEVEL FEATURES
OVER THE NEXT 24 HOURS...LEADING TO SOME UNCERTAINTY IN THE COVERAGE
AND AMOUNT OF PRECIPITATION THAT WILL OCCUR AHEAD OF THE COLD FRONT
TONIGHT. THE MAIN SHORTWAVE IS CURRENTLY LOCATED JUST TO THE EAST OF
LAKE WINNIPEG AND HAS A 1002MB SURFACE LOW LOCATED WITH IT. A COLD
FRONT STRETCHES SOUTH-SOUTHEAST FROM THIS LOW AND INTO NORTHERN
MINNESOTA (CURRENTLY FROM THE LAKE OF THE WOODS TO JUST TO THE EAST
OF FARGO). HAVE SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AROUND
PARK RAPIDS MINNESOTA A COUPLE HOURS AGO AND THEY HAVE BEEN MAKING
THERE WAY TO THE EAST TOWARDS LEECH LAKE AHEAD OF THAT FRONT AND IN
THE RIBBON OF DEEPER MOISTURE FROM 925-700MB AHEAD OF THE ASSOCIATED
TROUGH. OVER THE U.P....THE ABUNDANT DRY AIR SEEN ABOVE 700MB ON THE
12Z KGRB SOUNDING AND ON RAP ANALYSIS DATA...ASSOCIATED WITH THE
SURFACE RIDGE FROM A HIGH NEAR JAMES BAY...HAS BEEN LIMITING THE
EASTWARD EXTENT OF THE OF SHOWERS AS THEY MOVE INTO WESTERN LAKE
SUPERIOR. BUT WITH THE MOISTURE BELOW 700MB...HAVE SEEN DIURNAL CU
FILL IN THE GAPS FROM EARLIER TODAY BETWEEN THE SOUTHEASTERLY FLOW
UPSLOPE FOG AND LOW CLOUDS. TEMPERATURES HAVE WARMED INTO THE 70S
ACROSS THE AREA...WITH THE WARMEST VALUES OVER THE EAST WITH MORE
SUNSHINE. FINALLY FARTHER TO THE SOUTH...A SHORTWAVE ROUNDING THE
UPPER RIDGE OVER TEXAS/OKLAHOMA LED TO AN MCS MOVING THROUGH
NORTHEAST KANSAS AND SOUTHWEST MISSOURI EARLY THIS MORNING AND IT
HAS SINCE DISSIPATED. BUT WITH ANOTHER WAVE ROUNDING THE RIDGE
THROUGH NEBRASKA...WOULD EXPECT REDEVELOPMENT TO THE EAST OF THAT
AREA OVER THE NEXT COUPLE OF HOURS.
WITH THE SOUTHERN SHORTWAVE STAYING WELL TO THE SOUTH OF THE
AREA...THE MAIN FOCUS WILL BE WITH THE UPPER LOW NEAR LAKE WINNIPEG
SLOWLY WEAKENING AS IT MOVES EAST TOWARDS JAMES BAY. THIS WILL LEAD
TO THE SURFACE LOW FOLLOWING SUIT AND SLOWLY DRAGGING THE COLD FRONT
EAST ACROSS THE CWA. HAVE ALREADY SEEN SHOWERS/THUNDERSTORMS DEVELOP
IN NORTHERN MINNESOTA AHEAD OF THE FRONT AND WITH THE STORM MOTION
VALUES INDICATING EASTWARD MOVEMENT UP TO 30KTS...WOULD EXPECT THE
SHOWERS TO SPREAD EAST INTO WESTERN LAKE SUPERIOR AND EVENTUALLY THE
WESTERN U.P. TONIGHT. LIKE LAST NIGHT AND TODAY...THEY WILL BE
BATTLING THE EXISTING DRY MID LEVEL AIR AS THEY MOVE OUT AHEAD OF
THE SLOW MOVING SURFACE-850MB TROUGH...SO WOULD EXPECT SOME
DIMINISHMENT AS THEY HEAD TO THE EAST AND INTO THE CWA TONIGHT.
WOULD EXPECT SOME MARGINALLY SEVERE STORMS TO MOVE INTO WESTERN LAKE
SUPERIOR BEFORE THE DRY AIR AND LOSS OF DIURNAL HEATING STARTS TO
TAKE ITS TOLL. OVER THE CENTRAL AND EASTERN U.P....AM EXPECTED SOME
PATCHY GROUND FOG TO DEVELOP TONIGHT. THICKNESS WILL DEPEND ON THE
AMOUNT OF DECOUPLING THAT OCCURS TONIGHT. HAVE SHOWN THE THICKEST
FOG (AREAS COVERAGE) OVER THE CENTRAL U.P. FOR SOUTHERN
MARQUETTE...DICKINSON...DELTA...AND NORTHERN MENOMINEE COUNTIES.
WITH THE COLD FRONT STILL OFF TO THE WEST OF THE U.P. ON SUNDAY
MORNING...EXPECT THERE TO BE TIME FOR DIURNAL HEATING TO INCREASE
THE POTENTIAL FOR SHOWERS/THUNDERSTORMS OVER THE WEST/CENTRAL U.P.
DURING THE AFTERNOON. MODELS HAVE A VARIETY OF IDEAS ON ML CAPE
VALUES...RANGING FROM 250-2000 J/KG TOMORROW AFTERNOON JUST AHEAD OF
THE FRONT. LOOKING AT MODIFIED SOUNDINGS AND MEAN ML CAPE VALUES
FROM THE NCAR ENSEMBLES AND SREF...FEEL THAT VALUES AROUND 500-750
J/KG ARE A FAIRLY REASONABLE EXPECTATION AT THIS POINT. WITH 0-6KM
BULK SHEAR VALUES GENERALLY AROUND 25-30KTS...THERE IS THE POTENTIAL
FOR AN ISOLATED STRONGER STORM TOMORROW AFTERNOON. THAT MATCHES THE
IDEA FROM UPDRAFT VELOCITY/HELICITY FROM THE CAM/S AND CAM
ENSEMBLES. WITH WET BULB ZERO VALUES NEARING 10KFT AND FREEZING
LEVEL ABOVE 12KFT...THINK THAT WILL COMBINE WITH THE MARGINAL SHEAR
TO KEEP THE HAIL THREAT BORDERLINE. LIKED THE PREVIOUS SHIFTS
HANDLING OF THE DEVELOPMENT OF THE SHOWERS/THUNDERSTORMS ACROSS THE
CENTRAL U.P. (RAMPING UP TO LOCALIZED LIKELY VALUES OVER MARQUETTE
COUNTY) AND HAVE ONLY MADE MINOR ADJUSTMENTS BASED OFF LATEST MODEL
TRENDS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 506 AM EDT SAT AUG 8 2015
DURING THE LONG TERM...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA IS
FCST TO MOVE SLOWLY E INTO NRN ONTARIO BY SUN MORNING. AS THIS
FEATURE CONTINUES TO SHIFT SLOWLY E...A BUILDING RIDGE TO THE LEE OF
THE ROCKIES WILL FORCE A DEEPENING TROF INTO ERN NAMERICA DURING THE
FIRST HALF OF NEXT WEEK. THIS TROF WILL LIKELY LINGER THRU THE REST
OF THE WEEK. PRIOR TO THE DEEPENING TROF...A SERIES OF SHORTWAVES
TRACKING ACROSS THE PLAINS TO THE GREAT LAKES WILL PROVIDE SOME
OPPORTUNITY FOR SHRA/TSTMS. DEEPENING ERN TROF AND RESULTING NW FLOW
INTO THE GREAT LAKES DURING THE FIRST HALF OF NEXT WEEK WILL THEN
BRING DRY WEATHER. HOWEVER...TYPICAL FOR SUMMERTIME NW FLOW...ANY
SUBTLE SHORTWAVE DROPPING THRU THE AREA COULD SPARK ISOLD AFTN
CONVECTION. PCPN CHANCES WILL RETURN LATE IN THE WEEK AS THERE ARE
INDICATIONS OF A DECENT SHORTWAVE ROUNDING THE WRN PLAINS RIDGE AND
THEN DROPPING INTO THE ERN TROF. THIS WOULD RESULT IN POSSIBLE
CONVECTION WITH LOW-LEVEL JET/WAA REGIME AHEAD OF WAVE AND ALSO WITH
COLD FRONT THAT WOULD DROP S INTO THE GREAT LAKES. AS FOR TEMPS...
AFTER READINGS NOT TOO FAR FROM NORMAL (ON THE WARM SIDE OF NORMAL
FOR MOST LOCATIONS)...DEVELOPING NW FLOW EARLY NEXT WEEK WILL DROP
TEMPS TO BLO NORMAL...BUT NOT SIGNIFICANTLY AS THERE WON`T BE A TAP
OF CHILLY AIR FROM NORTHERN CANADA. ABOVE NORMAL TEMPS WILL RETURN
BY THU AHEAD OF THE AFOREMENTIONED SHORTWAVE ROUNDING THE RIDGE.
SOME COOLING SHOULD THEN FOLLOW BY THE WEEKEND...DEPENDING ON HOW
SHARPLY THE SHORTWAVE DROPS INTO THE ERN TROF.
BEGINNING SUN/SUN NIGHT...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA
WILL HAVE OPENED UP AND WILL BE DRIFTING ACROSS NRN ONTARIO. TO THE
S OF THIS FEATURE...THERE REMAINS UNCERTAINTY IN THE WEAKER
SHORTWAVE ENERGY TRACKING ACROSS THE PLAINS TO THE GREAT LAKES...
PARTICULARLY WITH RESPECT TO WHERE CONVECTION WILL BE FIRING WITH
THESE MORE SUBTLE FEATURES. HOWEVER...THERE HAS BEEN A FAIRLY
CONSISTENT SIGNAL IN THE MODELS FOR A SUBTLE SFC WAVE AND MORE
SUBSTANTIAL CONVECTIVE ACTIVITY TRACKING EASTWARD FROM VCNTY OF IA
EARLY SUN ON THE NRN EDGE OF STRONG INSTABILITY IN THAT AREA. THIS
WILL HELP KEEP STRONG INSTABILITY FROM BUILDING N ALONG COLD FRONT
THAT WILL BE MOVING INTO THE UPPER LAKES SUN/SUN NIGHT IN
ASSOCIATION WITH THE NRN ONTARIO SHORTWAVE. AHEAD OF APPROACHING
COLD FRONT...NAM/GFS SHOW MLCAPE INCREASING TO ROUGHLY 500 TO
1500J/KG OVER THE W HALF OF UPPER MI SUN (NAM AS HIGH AS 2000J/KG).
WHILE THERE MAY BE A FEW SHRA IN THE MORNING...APPROACHING COLD
FRONT AND WEAK DEEP LAYER QVECTOR CONVERGENCE SHOULD SPARK SCT
CONVECTION IN THE AFTN WHICH WILL THEN SPREAD E INTO SUN NIGHT
ALONG/AHEAD OF PASSING COLD FRONT. WITH DEEP LAYER SHEAR NO GREATER
THAN AROUND 25KT...NOT ANTICIPATING ANY SVR STORMS. HOWEVER...IF
INSTABILITY ENDS UP AT OR ABOVE THE HIGH END OF THE CURRENTLY
EXPECTED RANGE...COULDN`T RULE OUT A BRIEF ISOLD SVR STORM. LATEST
SPC OUTLOOKS DO NOT HIGHLIGHT UPPER MI FOR A SVR RISK SUN/SUN
NIGHT...AND THAT LOOKS RIGHT ON TRACK.
ON MON...COLD FRONT SHOULD BE JUST E OF THE FCST AREA AT 12Z...
ENDING THE RISK OF MORE ORGANIZED PCPN. THE NAM STILL MANAGES TO
BUILD MLCAPE UPWARDS OF 1500J/KG OVER THE SCNTRL AND E...BUT THE GFS
SHOWS LESS THAN 50J/KG. SINCE OTHER MODELS SUPPORT THE GFS WITH A
STRONGER PRES GRADIENT BTWN HIGH PRES BUILDING INTO THE NRN PLAINS
AND LOW PRES/COLD FRONT TO THE E...WILL FAVOR THE THE DRIER/LACK OF
INSTABILITY GFS SOLUTION. WILL LINGER SCHC POPS FOR SHRA OVER THE E
EARLY. OTHERWISE...PLAN TO CARRY A DRY FCST ON MON. EXPECT HIGHS IN
THE 70S...BUT IT WILL BE COOLER NEAR LAKE SUPERIOR...ESPECIALLY OVER
THE E UNDER NNW WINDS THERE.
MON NIGHT THRU WED...BUILDING UPPER RIDGE WITH AXIS ROUGHLY OVER THE
WRN HIGH PLAINS WILL FORCE A DEEPENING ERN NAMERICA TROF AND NW FLOW
OVER THE GREAT LAKES...RESULTING IN COOLER WEATHER...BUT ONLY A
LITTLE BLO NORMAL FOR EARLY/MID AUG. IN THE INTERIOR...NIGHTTIME MIN
TEMPS WILL PROBABLY BE IN THE 40S IN THE USUAL COOL SPOTS. THERE
CONTINUES TO BE SOME INDICATION OF A WEAK SHORTWAVE DROPPING THRU
THE UPPER LAKES ON TUE WHICH COULD GENERATE A FEW ISOLD SHRA WITH
DAYTIME HEATING. AT THIS POINT...THE POTENTIAL IS STILL LOW ENOUGH
TO PRECLUDE A MENTION OF PCPN IN THE FCST FOR TUE. WITH UPPER TROF
SHIFTING A BIT FARTHER E ON WED AND SFC HIGH PRES MORE FIRMLY OVER
THE AREA...DRY WEATHER IS EXPECTED TO CONTINUE. MAX TEMPS WILL BE A
LITTLE HIGHER ON WED.
THU/FRI...TRENDS IN MEDIUM RANGE GUIDANCE ARE FOR A STRONGER
SHORTWAVE TO CUT THRU THE NRN PORTION OF THE WRN RIDGE AND THEN DROP
MORE SHARPLY TO THE SE INTO THE ERN NAMERICA TROF LATE NEXT WEEK. IF
THIS TREND CONTINUES WITH THE NEXT SET OF MEDIUM RANGE GUIDANCE...
THEN SHRA/TSTM CHANCES WILL NEED TO BE INCREASED FOR THU...WITH PCPN
POSSIBLE AS EARLY AS WED DEPENDING ON WHERE WAA IS FOCUSED AHEAD OF
THE SHORTWAVE. THE 00Z ECWMF/GFS INDICATE COLD FRONT WILL BE S OF
THE AREA BY FRI...LEADING TO A DRY DAY AND SOME COOLING. WILL WAIT
TO SEE IF THESE TRENDS FOR THU/FRI HOLD UP IN THE NEXT ROUND OF
GUIDANCE BEFORE SHIFTING FCST MORE STRONGLY TOWARD THIS SOLUTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 150 PM EDT SAT AUG 8 2015
VFR DIURNAL CLOUDS WILL BE THE MAIN SHORT TERM CONCERN. THESE
CEILINGS HAVE BEEN GRADUALLY RISING WITH DAYTIME HEATING AND MIXING
AND EXPECT THAT TO CONTINUE INTO THE AFTERNOON AND THE HIGH END
MVFR CEILINGS SHOULD TRANSITION TO VFR WITHIN THE NEXT COUPLE
HOURS. OTHERWISE...A COLD FRONT FROM MINNESOTA THAT WILL MOVE
ACROSS THE AREA ON SUNDAY MAY PUSH A COUPLE SHOWERS THROUGH THE
WESTERN HALF OF UPPER MICHIGAN AND ONLY HAD ENOUGH CONFIDENCE TO
INCLUDE VCSH AT KCMX OVERNIGHT AND LATE IN THE PERIOD AT KSAW. ALSO
FOR KSAW...DEPENDING ON THE AMOUNT OF SCATTERING OF THE CLOUDS THIS
EVENING...COULD SEE LIFR-IFR CONDITIONS DEVELOP WITH PATCHY GROUND
FOG OVERNIGHT TONIGHT. HAVE WENT WITH LOW END MVFR VISIBILITIES FOR
NOW...BUT WILL BE SOMETHING TO MONITOR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 250 PM EDT SAT AUG 8 2015
A LOW MOVING FROM JUST EAST OF LAKE WINNIPEG TO JAMES BAY THIS
WEEKEND WILL SWEEP A SURFACE TROUGH ACROSS LAKE SUPERIOR ON
SUNDAY...LEADING TO A SHIFT IN THE WINDS FROM A LIGHT SOUTH TO
SOUTHEASTERLY DIRECTION TO THE NORTHWEST BY MONDAY. WITH A
GENERALLY LIGHT PRESSURE GRADIENT IN PLACE...EXPECT WINDS TO STAY
BELOW 20KTS THROUGH THE PERIOD...ESPECIALLY AFTER TUESDAY WHEN HIGH
PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THE MIDDLE OF
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
506 AM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 506 AM EDT SAT AUG 8 2015
DURING THE LONG TERM...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA IS
FCST TO MOVE SLOWLY E INTO NRN ONTARIO BY SUN MORNING. AS THIS
FEATURE CONTINUES TO SHIFT SLOWLY E...A BUILDING RIDGE TO THE LEE OF
THE ROCKIES WILL FORCE A DEEPENING TROF INTO ERN NAMERICA DURING THE
FIRST HALF OF NEXT WEEK. THIS TROF WILL LIKELY LINGER THRU THE REST
OF THE WEEK. PRIOR TO THE DEEPENING TROF...A SERIES OF SHORTWAVES
TRACKING ACROSS THE PLAINS TO THE GREAT LAKES WILL PROVIDE SOME
OPPORTUNITY FOR SHRA/TSTMS. DEEPENING ERN TROF AND RESULTING NW FLOW
INTO THE GREAT LAKES DURING THE FIRST HALF OF NEXT WEEK WILL THEN
BRING DRY WEATHER. HOWEVER...TYPICAL FOR SUMMERTIME NW FLOW...ANY
SUBTLE SHORTWAVE DROPPING THRU THE AREA COULD SPARK ISOLD AFTN
CONVECTION. PCPN CHANCES WILL RETURN LATE IN THE WEEK AS THERE ARE
INDICATIONS OF A DECENT SHORTWAVE ROUNDING THE WRN PLAINS RIDGE AND
THEN DROPPING INTO THE ERN TROF. THIS WOULD RESULT IN POSSIBLE
CONVECTION WITH LOW-LEVEL JET/WAA REGIME AHEAD OF WAVE AND ALSO WITH
COLD FRONT THAT WOULD DROP S INTO THE GREAT LAKES. AS FOR TEMPS...
AFTER READINGS NOT TOO FAR FROM NORMAL (ON THE WARM SIDE OF NORMAL
FOR MOST LOCATIONS)...DEVELOPING NW FLOW EARLY NEXT WEEK WILL DROP
TEMPS TO BLO NORMAL...BUT NOT SIGNIFICANTLY AS THERE WON`T BE A TAP
OF CHILLY AIR FROM NORTHERN CANADA. ABOVE NORMAL TEMPS WILL RETURN
BY THU AHEAD OF THE AFOREMENTIONED SHORTWAVE ROUNDING THE RIDGE.
SOME COOLING SHOULD THEN FOLLOW BY THE WEEKEND...DEPENDING ON HOW
SHARPLY THE SHORTWAVE DROPS INTO THE ERN TROF.
BEGINNING SUN/SUN NIGHT...MID LEVEL LOW CURRENTLY OVER SRN MANITOBA
WILL HAVE OPENED UP AND WILL BE DRIFTING ACROSS NRN ONTARIO. TO THE
S OF THIS FEATURE...THERE REMAINS UNCERTAINTY IN THE WEAKER
SHORTWAVE ENERGY TRACKING ACROSS THE PLAINS TO THE GREAT LAKES...
PARTICULARLY WITH RESPECT TO WHERE CONVECTION WILL BE FIRING WITH
THESE MORE SUBTLE FEATURES. HOWEVER...THERE HAS BEEN A FAIRLY
CONSISTENT SIGNAL IN THE MODELS FOR A SUBTLE SFC WAVE AND MORE
SUBSTANTIAL CONVECTIVE ACTIVITY TRACKING EASTWARD FROM VCNTY OF IA
EARLY SUN ON THE NRN EDGE OF STRONG INSTABILITY IN THAT AREA. THIS
WILL HELP KEEP STRONG INSTABILITY FROM BUILDING N ALONG COLD FRONT
THAT WILL BE MOVING INTO THE UPPER LAKES SUN/SUN NIGHT IN
ASSOCIATION WITH THE NRN ONTARIO SHORTWAVE. AHEAD OF APPROACHING
COLD FRONT...NAM/GFS SHOW MLCAPE INCREASING TO ROUGHLY 500 TO
1500J/KG OVER THE W HALF OF UPPER MI SUN (NAM AS HIGH AS 2000J/KG).
WHILE THERE MAY BE A FEW SHRA IN THE MORNING...APPROACHING COLD
FRONT AND WEAK DEEP LAYER QVECTOR CONVERGENCE SHOULD SPARK SCT
CONVECTION IN THE AFTN WHICH WILL THEN SPREAD E INTO SUN NIGHT
ALONG/AHEAD OF PASSING COLD FRONT. WITH DEEP LAYER SHEAR NO GREATER
THAN AROUND 25KT...NOT ANTICIPATING ANY SVR STORMS. HOWEVER...IF
INSTABILITY ENDS UP AT OR ABOVE THE HIGH END OF THE CURRENTLY
EXPECTED RANGE...COULDN`T RULE OUT A BRIEF ISOLD SVR STORM. LATEST
SPC OUTLOOKS DO NOT HIGHLIGHT UPPER MI FOR A SVR RISK SUN/SUN
NIGHT...AND THAT LOOKS RIGHT ON TRACK.
ON MON...COLD FRONT SHOULD BE JUST E OF THE FCST AREA AT 12Z...
ENDING THE RISK OF MORE ORGANIZED PCPN. THE NAM STILL MANAGES TO
BUILD MLCAPE UPWARDS OF 1500J/KG OVER THE SCNTRL AND E...BUT THE GFS
SHOWS LESS THAN 50J/KG. SINCE OTHER MODELS SUPPORT THE GFS WITH A
STRONGER PRES GRADIENT BTWN HIGH PRES BUILDING INTO THE NRN PLAINS
AND LOW PRES/COLD FRONT TO THE E...WILL FAVOR THE THE DRIER/LACK OF
INSTABILITY GFS SOLUTION. WILL LINGER SCHC POPS FOR SHRA OVER THE E
EARLY. OTHERWISE...PLAN TO CARRY A DRY FCST ON MON. EXPECT HIGHS IN
THE 70S...BUT IT WILL BE COOLER NEAR LAKE SUPERIOR...ESPECIALLY OVER
THE E UNDER NNW WINDS THERE.
MON NIGHT THRU WED...BUILDING UPPER RIDGE WITH AXIS ROUGHLY OVER THE
WRN HIGH PLAINS WILL FORCE A DEEPENING ERN NAMERICA TROF AND NW FLOW
OVER THE GREAT LAKES...RESULTING IN COOLER WEATHER...BUT ONLY A
LITTLE BLO NORMAL FOR EARLY/MID AUG. IN THE INTERIOR...NIGHTTIME MIN
TEMPS WILL PROBABLY BE IN THE 40S IN THE USUAL COOL SPOTS. THERE
CONTINUES TO BE SOME INDICATION OF A WEAK SHORTWAVE DROPPING THRU
THE UPPER LAKES ON TUE WHICH COULD GENERATE A FEW ISOLD SHRA WITH
DAYTIME HEATING. AT THIS POINT...THE POTENTIAL IS STILL LOW ENOUGH
TO PRECLUDE A MENTION OF PCPN IN THE FCST FOR TUE. WITH UPPER TROF
SHIFTING A BIT FARTHER E ON WED AND SFC HIGH PRES MORE FIRMLY OVER
THE AREA...DRY WEATHER IS EXPECTED TO CONTINUE. MAX TEMPS WILL BE A
LITTLE HIGHER ON WED.
THU/FRI...TRENDS IN MEDIUM RANGE GUIDANCE ARE FOR A STRONGER
SHORTWAVE TO CUT THRU THE NRN PORTION OF THE WRN RIDGE AND THEN DROP
MORE SHARPLY TO THE SE INTO THE ERN NAMERICA TROF LATE NEXT WEEK. IF
THIS TREND CONTINUES WITH THE NEXT SET OF MEDIUM RANGE GUIDANCE...
THEN SHRA/TSTM CHANCES WILL NEED TO BE INCREASED FOR THU...WITH PCPN
POSSIBLE AS EARLY AS WED DEPENDING ON WHERE WAA IS FOCUSED AHEAD OF
THE SHORTWAVE. THE 00Z ECWMF/GFS INDICATE COLD FRONT WILL BE S OF
THE AREA BY FRI...LEADING TO A DRY DAY AND SOME COOLING. WILL WAIT
TO SEE IF THESE TRENDS FOR THU/FRI HOLD UP IN THE NEXT ROUND OF
GUIDANCE BEFORE SHIFTING FCST MORE STRONGLY TOWARD THIS SOLUTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY MORNING)
ISSUED AT 1210 AM EDT SAT AUG 8 2015
A LOW CENTERED IN SOUTHERN WISCONSIN WILL MOVE SLOWLY EAST THIS
MORNING ALLOWING ISOLATED SHOWERS TO SLOWLY DISSIPATE. LINGERING LOW-
LEVEL MOISTURE WILL ALLOW FOR LIFR TO POSSIBLY VLIFR CONDITIONS TO
PERSIST AT ALL TAF SITES OVERNIGHT IN A LIGHT E-SE WIND FLOW. DRIER
AIR SHOULD GRADUALLY MOVE INTO THE AREA LATER THIS MORNING INTO THE
AFTERNOON BRINGING AN IMPROVEMENT TO CEILINGS AND VISIBILITIES WITH
VFR CONDITIONS EXPECTED BY AFTERNOON. A FRONTAL SYSTEM APPROACHING
FROM THE WEST TOWARD EVENING COULD BRING A CHANCE FOR SHOWERS LATE
IN THE TAF PERIOD AT BOTH KIWD AND KCMX. MEANWHILE...KSAW COULD SEE
A REDEVELOPMENT OF STRATUS AND MVFR CIGS BY LATE EVENING IN A
CONTINUED UPSLOPE SSE FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT AUG 8 2015
WILL CONTINUE TO TRACK BOAT OBSERVATIONS THIS MORNING TO GET A
BETTER HANDLE ON ANY FOG THAT MAY BET SET UP ACROSS LAKE SUPERIOR.
HOWEVER AT THIS TIME...IT LOOKS LIKE PATCHY TO AREAS OF FOG WILL BE
ABOUT THE EXTENT OF IT THIS MORNING...BEFORE DISSIPATING THIS
AFTERNOON.
EXPECT A WEAKENING LOW OVER E WI/S LAKE MI THIS MORNING. A SECONDARY
LOW LAKE WINNIPEG WILL SLOWLY MOVE E OVER THE NEXT FEW DAYS AND
REACH S JAMES BAY BY MONDAY. THAT LOW WILL SWEEP A TROUGH ACROSS THE
UPPER GREAT LAKES REGION ON SUNDAY. A HIGH PRESSURE RIDGE STRETCHING
FROM MANITOBA TO THE N PLAINS MONDAY WILL SLIDE OVER THE GREAT LAKES
TUESDAY AND WEDNESDAY. EXPECT WIND GUSTS LESS THAN 25KTS THROUGH THE
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 AM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 PM EDT FRI AUG 7 2015
FCST FOCUS IN THE MEDIUM RANGE PERIOD WL BE ON POPS THE SECOND HALF
OF THIS WEEKEND ASSOCIATED WITH STRONG DISTUBANCE OVER SCENTRAL
CANADA THAT WL BE DROPPING SLOWLY ESEWD THRU NW ONTARIO AND DRAGGING
A COLD FNT ACRS UPR MI ON SUN NGT. TEMPS AHEAD OF THE COLD FROPA WL
BE AOA NORMAL. DURING THE FIRST HALF OF THE NEXT WEEK...EXPECT TEMPS
TO FALL BLO NORMAL WITH NW FLOW ALOFT DEVELOPING BTWN A BLDG UPR RDG
IN THE PLAINS AND DEEPENING TROF DOWNSTREAM IN ERN NAMERICA. CNDN HI
PRES UNDER THIS NW FLOW ALOFT WL BRING GENERALLY DRY WX DURING THE
MON THRU WED PERIOD. LOOKS LIKE TEMPS WL REBOUND AOA NORMAL LATER IN
THE WEEK AS PLAINS RDG BLDS TOWARD THE WRN LKS.
SAT NGT THRU SUN NGT...STRONG SHRTWV OVER FAR NW ONTARIO THAT WL BE
TOPPING UPR RDG IN THE PLAINS IS FCST TO SLIDE SLOWLY ESE THRU NRN
ONTARIO. ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES...MOST OF
THE LATEST GUIDANCE INDICATE A FASTER PRIMARY COLD FROPA ON SUN NGT.
SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE ONTARIO SHRTWV
WL REMAIN TO THE N OF UPR MI...POPS/PCPN AMOUNTS AS EARLY AS SAT NGT
IN ADVANCE OF THIS COLD FNT WL DEPEND ON THE DEGREE TO WHICH MSTR
INFLOW INTO THE UPR LKS WL BE DISRUPTED BY A W-E ORIENTED BNDRY
STRETCHING FM IOWA INTO THE LOWER LKS AND CONVECTION THAT FIRES
ALONG THIS AXIS ACCOMPANYING THE PASSAGE OF ANOTHER SHRTWV OVER THAT
AREA. THE 12Z NAM IS MOST EXTREME SHOWING A NEAR ABSENCE OF PCPN
ACRS THE CWA DURING THIS ENTIRE PERIOD WITH A LACK OF ANY MSTR
INFLOW/DYNAMIC FORCING TO THE N OF STRONG TS COMPLEX/DEEPER SFC LO
TRACKING ALONG THE BNDRY. THE OTHER MODELS SHOW A MORE PRONOUNCED
AXIS OF HIER H85 THETA E AND THUS MORE DEEP LYR MSTR CNVGC/FORCING/
QPF. BEST CHC FOR SOMWHAT HIER POPS WL BE OVER THE W ON SAT EVNG AND
THEN THE CENTRAL ON SUN AFTN/EVNG...WHEN THE 12Z GFS SHOWS MUCAPE AS
HI AS 2500 J/KG...DURING PERIODS OF DAYTIME HEATING. BUT GIVEN
MODEL/TIMING UNCERTAINTIES AND SUPPORT FOR LARGER SCALE FORCING TO
PASS TO THE N AND S OF THE CWA...FCST WL POPS WL BE NO HIER THAN THE
CHC CATEGORY.
MON...SINCE RECENT MEDIUM RANGE GUIDANCE HAS TRENDED TO SPEED UP
PASSAGE OF COLD FROPA ATTENDANT TO SHRTWV SHIFTING ESEWD THRU NW
ONTARIO AND ARRIVAL OF DEEP LYR QVECTOR DVGC/LARGER SCALE
SUBSIDENCE/MID LVL DRYING...PCPN CHCS FOR MON LOOK TO BE
DIMINISHING. WITH MORE SUNSHINE...H85 TEMPS FCST IN IN THE 10 TO 12C
RANGE WL SUPPORT MAX TEMPS IN THE 70S. LOCATIONS NEAR LK SUP WL BE
COOLEST WITH LLVL NNW FLOW IN ADVANCE OF APRCHG CNDN HI PRES.
MON NGT THRU WED...THE UPR RDG IN THE PLAINS IS FCST TO AMPLIFY
EARLY IN THE WEEK...ALLOWING THE TROF IN ERN NAMERICA TO DEEPEN AND
A MORE PRONOUNCED NW FLOW ALOFT BTWN THESE FEATURES TO PREVAIL OVER
THE GREAT LKS. THE ARRIVAL OF CNDN HI PRES/H85 TEMPS AS LO AS 8 TO
10C WL RESULT IN GENERALLY DRY AND COOLER WX FOR MON NGT INTO WED.
ALTHOUGH SOME OF THE MODELS INDICATE A SHRTWV EMBEDDED IN THE NW
FLOW ALOFT COULD CAUSE SOME SHOWERS DURING DAYTIME HEATING ON TUE...
THE COVERAGE/INTENSITY OF THESE SHOWERS WL BE LIMITED BY THE ABSENCE
OF ANY DEEPER MSTR AND GENERAL LARGER SCALE SUBSIDENCE UNDER THE
CONFLUENT NW FLOW ALOFT. RETAINED GOING DRY FCST FOR NOW. WITH
PLENTY OF SUNSHINE...WED AFTN WL TURN WARMER AS H85 TEMPS REBOUND
TOWARD 15C OVER THE W AS THE PLAINS RDG SHIFTS TOWARD THE WRN LKS.
LATE WEEK...A NUMBER OF THE EXTENDED MODELS SHOW ANOTHER SHRTWV
ROUNDING THE TOP OF THE PLAINS RDG WL INFLUENCE THE AREA ON THU AND
BRING THE THREAT OF SOME SHOWERS/TS. AS THE UPR RDG TO THE W BUILDS
BACK TOWARD THE UPR LKS IN THE WAKE OF THIS SHRTWV PASSAGE...FRI
SHOULD BE DRY AND WARMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY MORNING)
ISSUED AT 1210 AM EDT SAT AUG 8 2015
A LOW CENTERED IN SOUTHERN WISCONSIN WILL MOVE SLOWLY EAST THIS
MORNING ALLOWING ISOLATED SHOWERS TO SLOWLY DISSIPATE. LINGERING LOW-
LEVEL MOISTURE WILL ALLOW FOR LIFR TO POSSIBLY VLIFR CONDITIONS TO
PERSIST AT ALL TAF SITES OVERNIGHT IN A LIGHT E-SE WIND FLOW. DRIER
AIR SHOULD GRADUALLY MOVE INTO THE AREA LATER THIS MORNING INTO THE
AFTERNOON BRINGING AN IMPROVEMENT TO CEILINGS AND VISIBILITIES WITH
VFR CONDITIONS EXPECTED BY AFTERNOON. A FRONTAL SYSTEM APPROACHING
FROM THE WEST TOWARD EVENING COULD BRING A CHANCE FOR SHOWERS LATE
IN THE TAF PERIOD AT BOTH KIWD AND KCMX. MEANWHILE...KSAW COULD SEE
A REDEVELOPMENT OF STRATUS AND MVFR CIGS BY LATE EVENING IN A
CONTINUED UPSLOPE SSE FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 442 AM EDT SAT AUG 8 2015
WILL CONTINUE TO TRACK BOAT OBSERVATIONS THIS MORNING TO GET A
BETTER HANDLE ON ANY FOG THAT MAY BET SET UP ACROSS LAKE SUPERIOR.
HOWEVER AT THIS TIME...IT LOOKS LIKE PATCHY TO AREAS OF FOG WILL BE
ABOUT THE EXTENT OF IT THIS MORNING...BEFORE DISSIPATING THIS
AFTERNOON.
EXPECT A WEAKENING LOW OVER E WI/S LAKE MI THIS MORNING. A SECONDARY
LOW LAKE WINNIPEG WILL SLOWLY MOVE E OVER THE NEXT FEW DAYS AND
REACH S JAMES BAY BY MONDAY. THAT LOW WILL SWEEP A TROUGH ACROSS THE
UPPER GREAT LAKES REGION ON SUNDAY. A HIGH PRESSURE RIDGE STRETCHING
FROM MANITOBA TO THE N PLAINS MONDAY WILL SLIDE OVER THE GREAT LAKES
TUESDAY AND WEDNESDAY. EXPECT WIND GUSTS LESS THAN 25KTS THROUGH THE
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...KF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 AM EDT SAT AUG 8 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 330 PM EDT FRI AUG 7 2015
A WEAK AREA OF LOW PRESSURE WILL MOVE INTO THE AREA TONIGHT AND
BRING SCATTERED SHOWERS. MOST OF THESE SHOWERS SHOULD EXIT THE AREA
LATE TONIGHT...GIVING THE REGION A NICE SATURDAY.
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL ARRIVE SUNDAY
AFTERNOON AND LINGER INTO THE EVENING. THIS WILL BE A MORE
WIDESPREAD RAIN...AND THERE MAY BE A FEW STRONG STORMS TOO.
TEMPERATURES THROUGH THE WEEKEND WILL BE MILD WITH DAYTIME HIGHS
MAINLY IN THE UPPER 70S TO AROUND 80.
A FEW SHOWERS MAY LINGER INTO MONDAY...BUT THEN WE SHOULD SEE A DRY
PERIOD FROM MONDAY NIGHT THROUGH THURSDAY. ANOTHER CHANCE OF RAIN
WILL MOVE IN FOR THURSDAY NIGHT AND FRIDAY. HIGHS EACH DAY SHOULD
REMAIN IN THE UPPER 70 TO MID 80S.
&&
.UPDATE...
ISSUED AT 928 PM EDT FRI AUG 7 2015
THE SHORTWAVE CURRENTLY MOVING ACROSS LOWER MICHIGAN CONTINUES TO
PRODUCE MODERATE RAIN OVER OUR NORTHERN COUNTIES. SEVERAL MESONET
SITES HAVE HAD BETWEEN .35 AND .50 INCHES OF RAIN OVER WESTERN
MASON COUNTY SO FAR THIS EVENING. AS A RESULT I HAVE INCREASED THE
POP TO NEAR 100% OVER OUR NORTHERN COUNTIES THROUGH AT LEAST
MIDNIGHT AND I ALSO INCREASED QPF TO NEAR HALF INCH OVER THE NW
SECTIONS OF OUR FORECAST AREA TONIGHT.
SOUTHERN AREAS...DUE TO THE DRY EASTERLY LOW LEVEL INFLOW TO THE
SYSTEM...WILL ONLY SEE SPRINKLES OR POSSIBLY AND A FEW HUNDERTHS
OF AN INCH OF RAIN IN ISOLATED LOCATIONS. FOR THE MOST PART AREAS
NEAR AND SOUTH OF INTERSTATE 96 WILL NOT SEE MUCH IN THE WAY OF
MEASURABLE RAIN TONIGHT.
THIS SYSTEM WILL SLOWLY CONTINUE TO WEAKEN AS IT MOVES ACROSS THE
AREA SO THE RAINFALL RATES WILL DECREASE OVER OUR NORTHERN
COUNTIES BY MIDNIGHT. EVEN SO THERE IS A TRAILING UPPER WAVE THAT
WILL COME ACROSS SOUTHWEST LOWER MICHIGAN JUST PRIOR TO SUNRISE.
THIS WILL RESULT IN ADDITIONAL SHOWERS ACROSS THE AREA. THE
LATEST RAP MODEL AND ASSOCIATED MODEL SOUNDINGS DO NOT SHOW ENOUGH
INSTABILITY FOR THUNDERSTORMS SO I EXPUNGED THE MENTION OF
THUNDERSTORMS FROM OUR OVERNIGHT FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI AUG 7 2015
A GOOD CHANCE OF RAIN TONIGHT...ESPECIALLY EARLY ON. THEN ANOTHER
STRONG CHANCE OF RAIN COMES SUNDAY AFTERNOON INTO THE EVENING.
TOPS WERE SLOWLY WARMING WITH THE SYSTEM THAT WAS MOVING ACROSS LAKE
MICHIGAN THIS AFTERNOON. HOWEVER...AS MENTIONED IN AN EARLIER
UPDATE...THE LOW LEVEL JET FUELING THESE SHOWERS WILL HOLD TOGETHER
THROUGH THIS EVENING...BUT THEN SLOWLY WEAKEN AND MOVE INTO NORTHERN
LOWER LATER TONIGHT. WILL INCREASE POPS TO LIKELY OVER CENTRAL
LOWER...WHILE KEEPING CHANCE POPS ELSEWHERE. SOME WEAK INSTABILITY
ARRIVES LATE TONIGHT WITH THE HIGHER DEW POINTS...SO INCLUDED THE
MENTION OF ISOLATED THUNDER.
OTHER THAN SOME LINGERING MORNING SHOWERS ACROSS THE NE CWA SATURDAY
MORNING...THE REST OF THE CWA SHOULD BE DRY ON SATURDAY AS WE WILL
BE IN BETWEEN SYSTEMS. LOW CLOUDS WILL BE COMMONPLACE FIRST
THING...BUT THESE SHOULD BREAK UP THROUGH THE DAY FOR PARTLY SUNNY
SKIES IN THE AFTERNOON.
THE MODELS ARE IN BETTER AGREEMENT SHOWING LOW PRESSURE EJECTING OUT
OF THE CENTRAL PLAINS ON SATURDAY AND TRACKING IT ACROSS THE LOWER
GREAT LAKES SUNDAY NIGHT. THE SYSTEM CONTINUES TO LOOK MORE
IMPRESSIVE WITH GOOD JET DYNAMICS MOVING ACROSS SW MI STARTING LATE
SATURDAY NIGHT AND CONTINUING INTO SUNDAY EVENING. AGREE WITH SPC
INCLUDING PORTIONS OF THE CWA IN THE MARGINAL RISK OF SEVERE.
HOWEVER SINCE WE WILL BE ON THE COOL SIDE OF THE SYSTEM MOST OF THE
INSTABILITY WILL BE ELEVATED. THIS LEAVES LARGE HAIL AS THE MAIN
SEVERE THREAT. INSTABILITY SHOULD NOT BE OFF THE CHARTS...SO ANY
SEVERE THREAT SHOULD BE LOW END. SEVERE TIME FRAME SHOULD SHOULD BE
LATE AFTERNOON/EARLY EVENING SUNDAY.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI AUG 7 2015
NO SIGNIFICANT CHANGE WITH A COLD FRONT EXPECTED TO BRING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ON MONDAY...AND THEN DRY AND
SEASONABLY COOL THROUGH NEXT WEEK. LOOKING FURTHER...SEASONABLY WARM
CONDITIONS RETURN TOWARDS NEXT WEEKEND WITH CONTINUED DRY CONDITIONS
THROUGH WEEK TWO.
MONDAYS FRONTAL PASSAGE SHOULD BE SUPPORTED BY ROUGHLY 500 J/KG OF
CAPE AND 0-6KM SHEAR OF 30KTS WHICH WOULD BE ENOUGH FOR A FEW
ISOLATED STRONG STORMS. HOWEVER...THE FORCING IS NOT OVERLY
IMPRESSIVE OR ORGANIZED BUT...THEN AGAIN...LATEST NWP IS TRENDING
STRONGER...SO POPS ARE UP A BIT TODAY.
REST OF THE WEEK LOOKS A LOT LIKE THIS WEEK WITH HIGH PRESSURE AND
LIKELY SOME DIURNAL FAIR WEATHER CLOUDINESS THROUGHOUT THE WEEK.
UPPER PATTERN CONTINUES TO FEATURE RIDGE OVER CENTRAL WEST WITH
CLOSED HIGH OVER WEST TEXAS AND A DOWNSTREAM TROUGH OVER THE EAST.
THE PATTERN AMPLIFIES A BIT EARLY NEXT WEEK LEADING TO THE COOLER
AND DRIER AIR OVER MICHIGAN FOR MIDWEEK AND THEN FLATTENS WITH
WARMER AND LIKELY A BIT MORE HUMID AIR FOR NEXT WEEKEND. LOOKING
FURTHER OUT THE PATTERN APPEARS TO MORE OR LESS REPEAT IN WEEK TWO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 123 AM EDT SAT AUG 8 2015
LIGHT RAIN SHOWERS CONTINUE TO MOVE ACROSS CENTRAL LOWER MI. A FEW
SHOWERS MAY CLIP THE NRN TAF SITES OVERNIGHT BUT NO RESTRICTIONS
TO VSBY. VFR EXPECTED THROUGH THE PERIOD.
&&
.MARINE...
ISSUED AT 330 PM EDT FRI AUG 7 2015
WINDS AND WAVES WILL STAY UNDER 3 FEET THROUGH THE SHORT TERM.
THUNDERSTORMS WILL BE THE MAIN THREAT...COMING IN LATE SATURDAY
NIGHT AND LINGERING THROUGH SUNDAY EVENING.
&&
.HYDROLOGY...
ISSUED AT 1241 PM EDT FRI AUG 7 2015
NO FLOODING ISSUES EXPECTED FOR THE NEXT WEEK OR MORE AS A
RELATIVELY DRY PATTERN REMAINS IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...COBB
AVIATION...04
HYDROLOGY...MACZKO
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A SHORTWAVE HAS UNDERCUT THE UPPER RIDGE OVER THE UPPER MISSISSIPPI
VALLEY AND IS NOW DIVING SOUTHEAST ACROSS EASTERN WISCONSIN. THAT
WAVE IS SUPPORTING THE SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
MOVING ACROSS THAT AREA. FARTHER TO THE WEST...A 1008MB SURFACE LOW
IS LOCATED NEAR EAU CLAIRE WISCONSIN. TO THE NORTHEAST OF THE
SURFACE LOW...AN AREA OF SHOWERS ARE MOVING EAST ACROSS UPPER
MICHIGAN AT THIS TIME...TIED TO THE NORTHERN EDGE OF THE 850-700MB Q-
VECTOR CONVERGENCE AND BROAD WARM AIR ADVECTION. THE HEAVIEST RAIN
SO FAR TODAY HAS FALLEN OVER THE WESTERN HALF OF THE U.P....WITH 0.5
TO 0.65 INCHES OF RAIN FALLING OVER THE BARAGA PLAINS TODAY. AMOUNTS
DIMINISH TO A TENTH OF AN INCH THROUGH 2PM FROM NEGAUNEE SOUTH TO
IRON MOUNTAIN AND EVEN LESS FARTHER TO THE EAST.
THE SURFACE LOW AND SHORTWAVE WILL SLOWLY DISSIPATE AS THEY MOVE TO
THE EAST-SOUTHEAST TONIGHT...LIMITING THE INFLUENCE OF BOTH FEATURES
THROUGH THE NIGHT. EXPECT THE SHOWERS TO DIMINISH AND DRIFT TO THE
SOUTHEAST THROUGH THE EVENING (TIED TO THE 850-700MB Q-VECTOR
CONVERGENCE)...AND LARGELY BE OUT OF THE CWA AROUND 06Z. BUT WITH
THE MODELS CONTINUING TO SHOW LOW LEVEL MOISTURE PIVOTING TO THE
NORTHWEST ON THE NORTHEAST SIDE OF THE 925-850 TROUGH IN
CENTRAL/NORTHERN WISCONSIN...EXPECT ABUNDANT LOW CLOUDS TO BE IN
PLACE ACROSS THE AREA. THESE LOW CLOUDS CAN ALREADY BE SEEN OVER
EASTERN MINNESOTA AND WESTERN WISCONSIN...AND THEY HAVE BEEN WORKING
INTO WESTERN UPPER MICHIGAN THROUGH THE DAY. THINK DRYING AND
INCREASING SUBSIDENCE ABOVE THAT...GENERALLY ABOVE 750MB OVER THE
WEST...WILL ALSO HELP THE DIMINISHMENT OF THE WIDESPREAD SHOWERS.
DID HOLD ONTO THE SHOWERS A LITTLE LONGER OVER THE HIGHER TERRAIN
UPSLOPE AREAS IN CENTRAL UPPER MICHIGAN DUE TO THE FAVORABLY
SOUTHEASTERLY FLOW...BUT THE PRECIPITATION MAY FALL MORE AS DRIZZLE
THAN RAIN. IN ADDITION...HAVE TRENDED FOG UP TO AREAS TO WIDESPREAD
VALUES OVER THE WEST/CENTRAL U.P. WHERE THE BETTER RAIN HAS FALLEN
AND TIED TO THE LOWEST 5KFT BEING SATURATED ON THE NAM/GFS
SOUNDINGS. ONE ITEM TO WATCH...THE LATEST RAP RUNS HAVE BEEN HOLDING
ONTO DRIER NEAR SURFACE AIR OVER THE NORTH CENTRAL...WHICH WOULD
GREATLY REDUCE THE POTENTIAL FOR LOW CLOUDS AND FOG.
EXPECT THE LOW LEVEL MOISTURE TO HOLD ON THROUGH THE FIRST HALF OF
SATURDAY OVER THE WESTERN HALF TO TWO-THIRDS OF THE U.P. BEFORE THE
CONTINUED SUBSIDENCE AND INFLUX OF DRIER AIR TRIES TO BREAK OF THE
CLOUDS. WHILE THAT SHOULD RAISE THE CEILINGS ACROSS THE AREA...STILL
EXPECT THE WESTERN CWA TO REMAIN MOSTLY CLOUDY...WHILE THE EASTERN
THIRD OF THE U.P. WILL EXPERIENCE LINGERING MID CLOUDS IN THE
MORNING...TRANSITIONING TO DIURNAL CU IN THE AFTERNOON.
CONTINUED TO SHOW SLIGHT CHANCE POPS MOVING INTO WESTERN LAKE
SUPERIOR AND FAR WESTERN UPPER MICHIGAN TOMORROW AFTERNOON...AHEAD
OF THE SURFACE TROUGH MOVING INTO NORTHERN MINNESOTA AND THE
NORTHERN EDGE OF A SHORTWAVE MOVING THROUGH SOUTHERN MINNESOTA AND
NORTHERN IOWA. THINK MOST OF THE PRECIPITATION WILL STAY OFF TO THE
WEST FOR TOMORROW.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 314 PM EDT FRI AUG 7 2015
FCST FOCUS IN THE MEDIUM RANGE PERIOD WL BE ON POPS THE SECOND HALF
OF THIS WEEKEND ASSOCIATED WITH STRONG DISTUBANCE OVER SCENTRAL
CANADA THAT WL BE DROPPING SLOWLY ESEWD THRU NW ONTARIO AND DRAGGING
A COLD FNT ACRS UPR MI ON SUN NGT. TEMPS AHEAD OF THE COLD FROPA WL
BE AOA NORMAL. DURING THE FIRST HALF OF THE NEXT WEEK...EXPECT TEMPS
TO FALL BLO NORMAL WITH NW FLOW ALOFT DEVELOPING BTWN A BLDG UPR RDG
IN THE PLAINS AND DEEPENING TROF DOWNSTREAM IN ERN NAMERICA. CNDN HI
PRES UNDER THIS NW FLOW ALOFT WL BRING GENERALLY DRY WX DURING THE
MON THRU WED PERIOD. LOOKS LIKE TEMPS WL REBOUND AOA NORMAL LATER IN
THE WEEK AS PLAINS RDG BLDS TOWARD THE WRN LKS.
SAT NGT THRU SUN NGT...STRONG SHRTWV OVER FAR NW ONTARIO THAT WL BE
TOPPING UPR RDG IN THE PLAINS IS FCST TO SLIDE SLOWLY ESE THRU NRN
ONTARIO. ALTHOUGH THERE ARE STILL SOME TIMING DIFFERENCES...MOST OF
THE LATEST GUIDANCE INDICATE A FASTER PRIMARY COLD FROPA ON SUN NGT.
SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE ONTARIO SHRTWV
WL REMAIN TO THE N OF UPR MI...POPS/PCPN AMOUNTS AS EARLY AS SAT NGT
IN ADVANCE OF THIS COLD FNT WL DEPEND ON THE DEGREE TO WHICH MSTR
INFLOW INTO THE UPR LKS WL BE DISRUPTED BY A W-E ORIENTED BNDRY
STRETCHING FM IOWA INTO THE LOWER LKS AND CONVECTION THAT FIRES
ALONG THIS AXIS ACCOMPANYING THE PASSAGE OF ANOTHER SHRTWV OVER THAT
AREA. THE 12Z NAM IS MOST EXTREME SHOWING A NEAR ABSENCE OF PCPN
ACRS THE CWA DURING THIS ENTIRE PERIOD WITH A LACK OF ANY MSTR
INFLOW/DYNAMIC FORCING TO THE N OF STRONG TS COMPLEX/DEEPER SFC LO
TRACKING ALONG THE BNDRY. THE OTHER MODELS SHOW A MORE PRONOUNCED
AXIS OF HIER H85 THETA E AND THUS MORE DEEP LYR MSTR CNVGC/FORCING/
QPF. BEST CHC FOR SOMWHAT HIER POPS WL BE OVER THE W ON SAT EVNG AND
THEN THE CENTRAL ON SUN AFTN/EVNG...WHEN THE 12Z GFS SHOWS MUCAPE AS
HI AS 2500 J/KG...DURING PERIODS OF DAYTIME HEATING. BUT GIVEN
MODEL/TIMING UNCERTAINTIES AND SUPPORT FOR LARGER SCALE FORCING TO
PASS TO THE N AND S OF THE CWA...FCST WL POPS WL BE NO HIER THAN THE
CHC CATEGORY.
MON...SINCE RECENT MEDIUM RANGE GUIDANCE HAS TRENDED TO SPEED UP
PASSAGE OF COLD FROPA ATTENDANT TO SHRTWV SHIFTING ESEWD THRU NW
ONTARIO AND ARRIVAL OF DEEP LYR QVECTOR DVGC/LARGER SCALE
SUBSIDENCE/MID LVL DRYING...PCPN CHCS FOR MON LOOK TO BE
DIMINISHING. WITH MORE SUNSHINE...H85 TEMPS FCST IN IN THE 10 TO 12C
RANGE WL SUPPORT MAX TEMPS IN THE 70S. LOCATIONS NEAR LK SUP WL BE
COOLEST WITH LLVL NNW FLOW IN ADVANCE OF APRCHG CNDN HI PRES.
MON NGT THRU WED...THE UPR RDG IN THE PLAINS IS FCST TO AMPLIFY
EARLY IN THE WEEK...ALLOWING THE TROF IN ERN NAMERICA TO DEEPEN AND
A MORE PRONOUNCED NW FLOW ALOFT BTWN THESE FEATURES TO PREVAIL OVER
THE GREAT LKS. THE ARRIVAL OF CNDN HI PRES/H85 TEMPS AS LO AS 8 TO
10C WL RESULT IN GENERALLY DRY AND COOLER WX FOR MON NGT INTO WED.
ALTHOUGH SOME OF THE MODELS INDICATE A SHRTWV EMBEDDED IN THE NW
FLOW ALOFT COULD CAUSE SOME SHOWERS DURING DAYTIME HEATING ON TUE...
THE COVERAGE/INTENSITY OF THESE SHOWERS WL BE LIMITED BY THE ABSENCE
OF ANY DEEPER MSTR AND GENERAL LARGER SCALE SUBSIDENCE UNDER THE
CONFLUENT NW FLOW ALOFT. RETAINED GOING DRY FCST FOR NOW. WITH
PLENTY OF SUNSHINE...WED AFTN WL TURN WARMER AS H85 TEMPS REBOUND
TOWARD 15C OVER THE W AS THE PLAINS RDG SHIFTS TOWARD THE WRN LKS.
LATE WEEK...A NUMBER OF THE EXTENDED MODELS SHOW ANOTHER SHRTWV
ROUNDING THE TOP OF THE PLAINS RDG WL INFLUENCE THE AREA ON THU AND
BRING THE THREAT OF SOME SHOWERS/TS. AS THE UPR RDG TO THE W BUILDS
BACK TOWARD THE UPR LKS IN THE WAKE OF THIS SHRTWV PASSAGE...FRI
SHOULD BE DRY AND WARMER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY MORNING)
ISSUED AT 1210 AM EDT SAT AUG 8 2015
A LOW CENTERED IN SOUTHERN WISCONSIN WILL MOVE SLOWLY EAST THIS
MORNING ALLOWING ISOLATED SHOWERS TO SLOWLY DISSIPATE. LINGERING LOW-
LEVEL MOISTURE WILL ALLOW FOR LIFR TO POSSIBLY VLIFR CONDITIONS TO
PERSIST AT ALL TAF SITES OVERNIGHT IN A LIGHT E-SE WIND FLOW. DRIER
AIR SHOULD GRADUALLY MOVE INTO THE AREA LATER THIS MORNING INTO THE
AFTERNOON BRINGING AN IMPROVEMENT TO CEILINGS AND VISIBILITIES WITH
VFR CONDITIONS EXPECTED BY AFTERNOON. A FRONTAL SYSTEM APPROACHING
FROM THE WEST TOWARD EVENING COULD BRING A CHANCE FOR SHOWERS LATE
IN THE TAF PERIOD AT BOTH KIWD AND KCMX. MEANWHILE...KSAW COULD SEE
A REDEVELOPMENT OF STRATUS AND MVFR CIGS BY LATE EVENING IN A
CONTINUED UPSLOPE SSE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 254 PM EDT FRI AUG 7 2015
A LOW PRESSURE SYSTEM OVER WESTERN WISCONSIN WILL DISSIPATE TONIGHT
INTO SATURDAY MORNING AS IT MOVES EAST. MEANWHILE...A STRONGER LOW
NEAR LAKE WINNIPEG WILL MOVE TO JAMES BAY BY MONDAY..SWEEPING A
BROAD TROUGH ACROSS THE UPPER GREAT LAKES REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE TROUGH...AND CONTINUE INTO THE MIDDLE OF
NEXT WEEK. WITH WEAK PRESSURE GRADIENTS EXPECTED...WINDS ARE
EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. FINALLY...WITH
RAIN AND ABUNDANT LOW LEVEL MOISTURE MOVING OVER WESTERN AND
CENTRAL LAKE SUPERIOR...COULD SEE SOME PATCHY FOG OVER THOSE AREAS
TONIGHT INTO SATURDAY MORNING...BUT DON/T EXPECT WIDESPREAD...DENSE
FOG AT THIS TIME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...VOSS
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
335 PM CDT SAT AUG 8 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 336 PM CDT SAT AUG 8 2015
THE MAIN SHORT TERM CONCERN IS THE CONVECTIVE THREAT INTO THE
EVENING AND REDEVELOPING SUNDAY.
WIDELY SCATTERED SHOWERS CONTINUE TO MOVE EAST ACROSS THE AREA.
SOME HEATING OCCURRED TO THE WEST AND SOUTH AS CLOUDS CLEARED SOME.
THE LATEST SPC MESOSCALE ANALYSIS SHOWS MLCAPE 1500-200 J/KG OVER
THE MN PORTION OF THE AREA. BEST SHEAR IS LOCATED OVER NORTHEAST MN
IN THE AREA WHERE A MORE CONCENTRATED AREA OF STORMS CURRENTLY
RESIDES. ANY REAL SEVERE POTENTIAL WILL BE FOUND IN THIS AREA INTO
THE EVENING...POSSIBLE MAKING IT INTO THE NORTHEAST PORTION OF THE
CWA. WILL CONTINUE THE HIGHER CHANCE POPS IN THIS AREA...TRAILING
OFF TO SLIGHT CHANCE TO THE SOUTH. UPPER TROUGH MOVING ACROSS THE
NORTHERN PORTION OF THE STATE SHOULD DRIVE MAIN CONVECTIVE THREAT
OVER THE NORTHEAST. ALSO...SHOULD SEE STORMS GRADUALLY WEAKEN WITH
THE LOSS OF HEATING INTO THE EVENING.
AT THE MOMENT...FEEL THERE WILL BE ENOUGH CLOUD COVER AROUND FROM
THE FRONT TO THE NORTH AND THE MCS TO THE SOUTH TO LIMIT SIGNIFICANT
FOG. HOWEVER...IF THE SKY CLEARS OUT SIGNIFICANTLY LATE
TONIGHT...FOG MAY BECOME MORE OF AN ISSUE WITH LIGHT WINDS AND
HIGHER DEWPOINTS AROUND.
THE SURFACE FRONT DROPS INTO THE AREA SUNDAY WITH ATTENDANT CHANCE
OF -TSRA MAINLY IN THE AFTERNOON. WE CURRENTLY HAVE A MARGINAL
SEVERE RISK OVER THE SOUTHWEST PORTION OVER THE CWA...WHICH LOOKS
BEST AT THIS TIME.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 336 PM CDT SAT AUG 8 2015
THE LONG TERM FORECAST IS BOOK-ENDED WITH SHOWER AND
THUNDERSTORM CHANCES...BUT WILL BE MARKED OVERALL BY DRY AND
BENIGN WEATHER.
SUNDAY NIGHT THE WASHED OUT BOUNDARY WILL BE STRETCHED FROM
SOUTHERN MN INTO CENTRAL WI. THIS WILL BE THE MOST LIKELY
OPPORTUNITY FOR SHOWERS AND THUNDERSTORMS AS A SHORTWAVE MOVES
OVERHEAD ON THE NORTHERN PERIPHERY OF THE SOUTHERN PLAINS MID
LEVEL RIDGE. MOISTURE CONVERGENCE IS ADMITTEDLY BETTER TO THE
SOUTH...BUT WE WILL HAVE PLENTY OF ANTECEDENT MOISTURE TO COMBINE
WITH THE LIFT PROVIDED BY THE SHORTWAVE TROUGH.
MONDAY MORNING WILL LIKELY BE MET WITH LINGERING SHOWERS AND
THUNDERSTORMS OVER SOUTHEAST MN...BUT EXPECT THE BOUNDARY AND
ASSOCIATED PRECIP TO BE OUT OF THE AREA BY THE AFTERNOON.
MONDAY NIGHT AND TUESDAY BRINGS THE ARRIVAL OF BROAD SURFACE HIGH
PRESSURE...WHICH WILL TRANSLATE TO LIGHT WINDS...MOSTLY
CLEAR/SUNNY SKIES...AND SEASONAL TEMPS. COULD SEE SOME FOG
FORMATION DURING THE OVERNIGHT PERIODS...BUT AN OTHERWISE A BENIGN
WEATHER FORECAST WITH FEW CONCERNS IS ANTICIPATED INTO THURSDAY.
THURSDAY NOW LOOKS TO FEATURE SMALL SHOWER AND THUNDERSTORM
CHANCES WITH THE ARRIVAL OF A WEAK BOUNDARY ACROSS THE AREA AS A
WEAK MID LEVEL TROUGH SKIRTS THE INTERNATIONAL BORDER. HAVE
INCLUDED 20-30 POPS ON THURSDAY AND THURSDAY NIGHT...BUT IT
CERTAINLY DOES NOT LOOK TO BE A WASHOUT.
HIGH TEMPS THROUGH THE PERIOD WILL VARY FROM THE UPPER 70S TO
LOWER 80S...WITH THE EXCEPTION OF THURSDAY WHEN SLIGHTLY HIGHER
TEMPS ARE EXPECTED AHEAD OF THE APPROACHING BOUNDARY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1255 PM CDT SAT AUG 8 2015
-SHRA/ISOLD -TSRA OVER MUCH OF CENTRAL MN LATE THIS MORNING. THIS
ARE BEING GENERATED AHEAD OF SURFACE BOUNDARY OVER THE DAKOTAS
WITH SOME WEAK LOWER LEVEL FRONTOGENESIS/WAA. LATEST HRRR TRENDS
SHOW THIS AREA MOVING EAST THE REST OF THE AFTERNOON. SOME
REDEVELOPMENT EXPECTED ALONG/AHEAD OF THE BOUNDARY...MAINLY
OVER THE NORTHWEST AREA/KAXN/KSTC INTO THE EVENING. APPEAR
ACTIVITY WILL BE MAINLY DIURNAL WITH WEAKENING TREND EXPECTED BY
SUNSET. MVFR CIGS CURRENTLY OVER WISCONSIN WILL LIFT THIS
AFTERNOON AND MAY BREAK OUT IN SPOTS. OTHERWISE MAINLY VFR OUTSIDE
OF -SHRA/-TSRA WHICH WILL REMAIN WIDELY SCT/ISOLD. IF THE SKY
CLEARS OUT SIGNIFICANTLY...WILL LIKELY SEE MORE FOG DEVELOP. MOST
OF THE AREA IS EXPECTED TO MAINTAIN SOME CLOUD COVER WHICH SHOULD
LIMIT SIGNIFICANT FOG AT TAF SITES.
KMSP...VFR EXPECTED WITH MIX OF CLOUD HEIGHTS INTO THE AFTERNOON.
-SHRA BAND OVER CENTRAL MN WILL AFFECT THE AREA THROUGH ABOUT 22Z
OR SO. CONFIDENCE ON THUNDER IS LOW AT THIS TIME. BETTER CHANCE OF
THAT NEAR THE SURFACE BOUNDARY TO THE NORTHWEST AND IN SOME
CLEARING OVER SOUTH CENTRAL MN. SHOULD SEE ANY SHOWERS COME TO AN
END THIS EVENING AND THEN REDEVELOPMENT POSSIBLE INTO SUNDAY
AFTERNOON/EVENING WITH THE FRONT. SFC WINDS SE-S THIS AFTERNOON
BECOMING LIGHT OVERNIGHT.
/OUTLOOK FOR KMSP/
SUN NITE....VFR. CHC MVFR CIGS -TSRA. WINDS NW 5-10 KNOTS.
MON-TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...LS
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1254 PM CDT SAT AUG 8 2015
.UPDATED FOR 18Z AVIATION DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 418 AM CDT SAT AUG 8 2015
MAIN CONCERN FOR THE SHORT TERM REMAINS THE CHANCE OF SHOWERS AND
THUNDERSTORMS. TROUGH EXTENDING FROM LARGE UPPER LOW IN SOUTHERN
MANITOBA EXTENDS TO MN AND SD...BUT ITS SOUTHERN REACH IS CERTAINLY
BEING AFFECTED BY THE MCS IN IOWA. HEIGHTS BEGIN RISING SLIGHTLY
THIS AFTERNOON ONCE THE MCS PASSES THE REGION. SLIGHT RIDGING
CONTINUES INTO THIS EVENING OVER MN AND WI...UNTIL THE NEXT WEAK
SHORT WAVE APPROACHES LATE TONIGHT...BUT THE IMPACT OF THAT WILL
MAINLY BE ON SUNDAY. HAVE KEPT POPS FOR LATE TONIGHT IN WESTERN
SECTIONS.
MEANWHILE...SPOTTY SHOWERS AND THUNDERSTORMS CONTINUE TO DEVELOP
EARLY THIS MORNING FROM NORTHERN MN INTO SE SD AND SW MN. SHEAR
VALUES ARE OK FOR STORMS BUT LOW AND MID LEVEL LAPSE RATES ARE
RATHER POOR TODAY AND TONIGHT. A VARIETY OF CAMS DID FLAG THE RECENT
DEVELOPMENT OF STORMS IN EASTERN SD...AND THIS IS EVIDENT IN THE
STORMS RECENTLY DEVELOPED IN EASTERN SD. WILL NEED TO CONTINUE THE
MENTION OF POPS THIS MORNING...ESPECIALLY IN WEST CENTRAL AND
CENTRAL MN. MAIN THERMAL GRADIENT IS DRAPED FROM NORTHEAST MN TO THE
WEST CENTRAL...AND THIS IS WHERE STORMS COULD REDEVELOP LATER THIS
AFTERNOON WITH ENOUGH HEATING.
LOW CLOUDS FROM RICE LAKE TO EAU CLAIRE AREA WILL GRADUALLY DIMINISH
LATER THIS MORNING. A LITTLE DENSE FOG HAS FORMED JUST ON THE
PERIPHERY OF THE LOW CLOUDS...BUT THIS SHOULD DISSIPATE DURING THE
MID MORNING AFTER SOME HEATING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 418 AM CDT SAT AUG 8 2015
MINNESOTA AND WISCONSIN WILL BE BETWEEN DISTURBANCES ON SUNDAY.
THE SATURDAY NIGHT MCS ACROSS IOWA WILL BE HEADED EAST ACROSS
NORTHERN AND CENTRAL IL SUNDAY MORNING...WITH THE LAST OF THE
WESTERN ENERGY EJECTING EASTWARD ACROSS THE DAKOTAS BY AFTERNOON.
THIS LEAVES THE AREA WITH LITTLE TO SUPPORT THUNDERSTORM
DEVELOPMENT UNTIL THE NORTHERN PLAINS ENERGY ARRIVES SUNDAY NIGHT.
POPS WERE INCREASED ACROSS MN SUNDAY NIGHT AS THIS WAVE TRACKS
EAST SOUTHEASTWARD ON THE NORTHEAST PERIPHERY OF THE RETROGRADING
MID LEVEL RIDGE TO THE SOUTH. MODELS ARE IN PRETTY GOOD AGREEMENT
IN ADVERTISING SHOWERS AND THUNDERSTORMS ACROSS WRN/SRN MN SUNDAY
NIGHT. RAINFALL AMOUNTS SHOULD NOT BE ALL THAT SIGNIFICANT ON A
WIDESPREAD BASIS WITH THE ABSENCE OF A LLJ HELPING TO ORGANIZE
THE ACTIVITY...BUT PW VALUES NEARING 1.75 INCHES WILL LEND
CREDENCE TO LOCALIZED HEAVY RAINFALL RATES TOWARD SOUTHWESTERN
MINNESOTA.
AFTER THAT PIECE OF ENERGY EXITS TO THE SOUTHEAST MONDAY
MORNING...SURFACE HIGH PRESSURE WILL SLOWLY TRACK SOUTHEAST ACROSS
THE MISSISSIPPI VALLEY NEXT WEEK. A GRADUAL WARMING TREND CAN BE
EXPECTED WITH THICKNESSES BUILDING THROUGH THE WEEK. COULD SEE A
WEAK FRONT PUSH THROUGH LATE WEEK IF ANOTHER TROUGH SWINGS THROUGH
EASTERN CANADA. THIS WOULD BRING THE NEXT LOW CHANCE OF STORMS.
OTHERWISE...SEVERAL DAYS OF DRY WEATHER ARE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1255 PM CDT SAT AUG 8 2015
-SHRA/ISOLD -TSRA OVER MUCH OF CENTRAL MN LATE THIS MORNING. THIS
ARE BEING GENERATED AHEAD OF SURFACE BOUNDARY OVER THE DAKOTAS
WITH SOME WEAK LOWER LEVEL FRONTOGENESIS/WAA. LATEST HRRR TRENDS
SHOW THIS AREA MOVING EAST THE REST OF THE AFTERNOON. SOME
REDEVELOPMENT EXPECTED ALONG/AHEAD OF THE BOUNDARY...MAINLY
OVER THE NORTHWEST AREA/KAXN/KSTC INTO THE EVENING. APPEAR
ACTIVITY WILL BE MAINLY DIURNAL WITH WEAKENING TREND EXPECTED BY
SUNSET. MVFR CIGS CURRENTLY OVER WISCONSIN WILL LIFT THIS
AFTERNOON AND MAY BREAK OUT IN SPOTS. OTHERWISE MAINLY VFR OUTSIDE
OF -SHRA/-TSRA WHICH WILL REMAIN WIDELY SCT/ISOLD. IF THE SKY
CLEARS OUT SIGNIFICANTLY...WILL LIKELY SEE MORE FOG DEVELOP. MOST
OF THE AREA IS EXPECTED TO MAINTAIN SOME CLOUD COVER WHICH SHOULD
LIMIT SIGNIFICANT FOG AT TAF SITES.
KMSP...VFR EXPECTED WITH MIX OF CLOUD HEIGHTS INTO THE AFTERNOON.
-SHRA BAND OVER CENTRAL MN WILL AFFECT THE AREA THROUGH ABOUT 22Z
OR SO. CONFIDENCE ON THUNDER IS LOW AT THIS TIME. BETTER CHANCE OF
THAT NEAR THE SURFACE BOUNDARY TO THE NORTHWEST AND IN SOME
CLEARING OVER SOUTH CENTRAL MN. SHOULD SEE ANY SHOWERS COME TO AN
END THIS EVENING AND THEN REDEVELOPMENT POSSIBLE INTO SUNDAY
AFTERNOON/EVENING WITH THE FRONT. SFC WINDS SE-S THIS AFTERNOON
BECOMING LIGHT OVERNIGHT.
/OUTLOOK FOR KMSP/
SUN NITE....VFR. CHC MVFR CIGS -TSRA. WINDS NW 5-10 KNOTS.
MON-TUE...VFR. WINDS NW 5-10 KTS.
WED...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TDK
LONG TERM...BORGHOFF
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS DULUTH MN
335 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 331 AM CDT SAT AUG 8 2015
UPDATED TO EXPAND FOG ADVISORY TO ST. CROIX RIVER VALLEY OF PINE
AND BURNETT COUNTY...WHERE VISIBILITIES ARE CURRENTLY A HALF
MILE...AND SHOULD ONLY GET WORSE IN THE NEXT FEW HOURS. EXPIRATION
TIME REMAINS THE SAME.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
COMPLICATED WEATHER SCENE OUT THERE THIS MORNING WITH A STRONG
SURFACE LOW OVER MANITOBA...AND A WEAK FRON DRAPED SOUTH ACROSS
THE EASTERN DAKOTAS. LAST EVENING THUNDERSTORMS DEVELOPED ALONG
THIS FRONT...AND HAVE PUSHED EAST INTO THE FOREAST AREA EARLY THIS
MORNING. THEY HAVE BEEN MAINTAINING STRENGTH ACROSS THE WESTERN
CWA...BUT ONCE THEY GET INTO THE CENTRAL PORTIONS OF THE CWA THEY
HAVE BEEN DIMINISHING RAPIDLY DUE TO THE LACK OF INSTABILITY
FARTHER EAST. ALSO OF CONCERN THIS MORNING IS THE FOG. LAST NIGHTS
RAINFALL CREATED EXCELLENT PRECONDITIONS FOR FOG...AND WITH OUR
TEMPERATURES AND DEWPOINTS IN THE MIDDLE-UPPER 50S HERE WE ARE
WITH FOG OVER MUCH OF THE FORECAST AREA. IT IS WORST AROUND LAKE
SUPERIOR FROM ASHLAND...THROUGH THE TWIN PORTS AND UP THE NORTH
SHORE WHERE A QUARTER MILE VISIBILITY IS PRETTY COMMON. ANY STORMS
THAT GET FAR ENOUGH EAST TO MOVE ACROSS THE FOG IS LIKELY TO BRING
THE VISIBILITY UP TEMPORARILY...BUT IT SHOULD GO RIGHT BACK DOWN.
FOG SHOULD DISSIPATE WITH THE INCREASING TEMPERATURES IN THE
MORNING SO HAVE PUT OUT A DENSE FOG ADVISORY FOR THE WORST
AFFECTED AREAS UNTIL 10 AM.
TODAY THE EARLY MORNING CONVECTION IS LIKELY TO DISSIPATE IN THE
NEXT 3-6 HOURS...ESPECIALLY AS IT IS ALREADY SHOWING SIGNS OF
WEAKENING WITH WEAKER STORMS AND MORE STRATIFORM APPEARANCE ON
RADAR. IN COMBINATION WITH THE WEAKENING TREND AS STORMS MOVE
EAST...EXPECT US TO BE DOWN TO JUST SHOWERS BY SUNRISE OR SHORTLY
AFTER. HOWEVER...THIS IS UNLIKELY TO LAST AS INSTABILITY WILL BUILD
ONCE AGAIN AHEAD OF THE COLD FRONT AS IT SLOWLY MOVES INTO THE
WESTERN CWA THIS AFTERNOON. BETWEEN THAT AND THE RESPECTABLE SHEAR
THAT WILL BE OVER THE AREA THIS AFTERNOON WE SHOULD HAVE SOME STRONG
TO EVEN A FEW SEVERE STORMS THIS AFTERNOON AND EVENING AS THE FRONT
SAGS SLOWLY ACROSS NORTHERN MINNESOTA. THE FRONT SHOULD CONTINUE TO
SAG SOUTHEAST OVERNIGHT TONIGHT...AND CONTINUE ON INTO NORTHWEST
WISCONSIN FOR SUNDAY. HOWEVER...ON SUNDAY THE CONVERGENCE ALONG THE
BOUNDARY IS MUCH WEAKER...THE SHEAR IS MUCH WEAKER AS IS THE
INSTABILITY...SO DO NOT EXPECT AS MUCH INTENSITY OR COVERAGE FROM
THE STORMS AND HAVE GONE WITH LOWER POPS. OTHERWISE...TEMPERATURES
TO REMAIN SEASONABLE...WITH COOLER TEMPS NEAR THE LAKE AS USUAL.
EXPECT FOG AGAIN ACROSS THE AREA TONIGHT WITH THE RECENT RAINFALL
AND LIGHT WINDS...AND HAVE PUT IN AREAS OF FOG FOR A LARGE PORTION
OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
A WEAKENING UPPER LEVEL TROF IS FORECAST TO MOVE OUT OF THE AREA
SUNDAY EVENING...BUT NOT BEFORE DROPPING SOME RAIN ALONG THE
SOUTHERN EDGE OF THE REGION. THIS ACTIVITY WILL QUICKLY DEPART BY
06Z AND HAVE REMOVED THE POPS THEREAFTER AS HIGH PRESSURE IS
BUILDING IN. ON MONDAY...EVEN THOUGH HIGH PRESSURE COVERS THE
AREA...AN UPPER LEVEL TROF WILL SWING THROUGH THE ARROWHEAD AND HAVE
POPS TO REFLECT THIS. THE TROF MOVES EAST OF THE AREA MONDAY NIGHT
LEAVING THE SFC HIGH IN CHARGE. UPPER LEVEL RIDGING EDGES BACK
ACROSS THE REGION TUESDAY WHILE THE SFC HIGH REMAINS NEARBY. THE
RIDGING PREVAILS THROUGH WEDNESDAY. WEDNESDAY NIGHT FINDS A MID
LEVEL TROF MOVING ACROSS THE ARROWHEAD. THE GFS IS SUFFERING FROM
CONVECTIVE/GRIDSCALE FEEDBACK AND PUSHES A LARGE COLD FRONT INTO NE
MN. MEANWHILE...THE ECMWF HAS A WEAK SFC TROF ALONG THE CANADIAN
BORDER WITH SOME LIGHT QPF WITH THE GEM FURTHER TO THE WEST WITH THE
TROF AND NO RAIN. USED A BLEND OF THE GEM/ECMWF FOR POPS. MODEL
DIFFERENCES BECOME QUITE LARGE THURSDAY AND FRIDAY WITH THE HANDLING
OF AN UPPER TROF AND ASSOCIATED FRONTAL BOUNDARY. KEPT WITH THE
BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 106 AM CDT SAT AUG 8 2015
A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVE INTO THE NORTHLAND
DURING THE FORECAST PERIOD. THIS HAS GENERATED SHOWERS AND STORMS
OVER WESTERN AND NORTH CENTRAL MINNESOTA. CURRENTLY STORMS ARE
MOVING THROUGH KINL. EXPECTING THIS ACTIVITY TO SPREAD EASTWARDS
AND AFFECT ALL OTHER TERMINALS...EXCEPT FOR KHYR BETWEEN 07Z AND
12Z. THIS MATCHES WELL WITH THE CURRENT RADAR TRENDS ALONG WITH
THE LAST SEVERAL HRRR RUNS.
EXPECTING ALL TERMINALS TO SEE EITHER IFR OR LIFR CONDITIONS AT
SOME POINT AS THE NIGHT PROGRESSES INTO THE EARLY MORNING HOURS.
MOST CONFIDENT OF LIFR CIGS AND VISBYS FOR KDLH AND KHYR UNTIL 14Z
TO 17Z.
WILL SEE ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT
DUE TO DAY TIME HEATING IN COMBINATION WITH THE FRONT MOVING
THROUGH MINNESOTA SATURDAY AFTERNOON. THINK THAT KINL AND KBRD MAY
BE ON THE BACKSIDE OF THE FRONT BY THE TIME THIS OCCURS...SO LEFT
IN AS VCSH...AND EVENTUALLY BROUGHT KINL AND KBRD TO VFR
CONDITIONS BETWEEN 21Z AND 02Z. EXPECTING ALL OTHER TERMINALS TO
SEE SHOWERS AND STORMS DURING THE AFTERNOON...HOWEVER UNSURE ON
THE EXACT LOCATION OF SPECIFIC STORMS...SO LEFT AS VCTS. SOME OF
THESE STORMS MAY BE STRONG DURING THE AFTERNOON AND HEADING INTO
THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 72 60 78 58 / 40 50 10 10
INL 78 54 74 55 / 40 10 0 10
BRD 79 60 80 58 / 50 40 20 10
HYR 76 60 78 57 / 20 30 20 20
ASX 74 60 78 58 / 30 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001>003-
006.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037-038.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...LE
LONG TERM...GSF
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
322 AM CDT SAT AUG 8 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
COMPLICATED WEATHER SCENE OUT THERE THIS MORNING WITH A STRONG
SURFACE LOW OVER MANITOBA...AND A WEAK FRON DRAPED SOUTH ACROSS
THE EASTERN DAKOTAS. LAST EVENING THUNDERSTORMS DEVELOPED ALONG
THIS FRONT...AND HAVE PUSHED EAST INTO THE FOREAST AREA EARLY THIS
MORNING. THEY HAVE BEEN MAINTAINING STRENGTH ACROSS THE WESTERN
CWA...BUT ONCE THEY GET INTO THE CENTRAL PORTIONS OF THE CWA THEY
HAVE BEEN DIMINISHING RAPIDLY DUE TO THE LACK OF INSTABILITY
FARTHER EAST. ALSO OF CONCERN THIS MORNING IS THE FOG. LAST NIGHTS
RAINFALL CREATED EXCELLENT PRECONDITIONS FOR FOG...AND WITH OUR
TEMPERATURES AND DEWPOINTS IN THE MIDDLE-UPPER 50S HERE WE ARE
WITH FOG OVER MUCH OF THE FORECAST AREA. IT IS WORST AROUND LAKE
SUPERIOR FROM ASHLAND...THROUGH THE TWIN PORTS AND UP THE NORTH
SHORE WHERE A QUARTER MILE VISIBILITY IS PRETTY COMMON. ANY STORMS
THAT GET FAR ENOUGH EAST TO MOVE ACROSS THE FOG IS LIKELY TO BRING
THE VISIBILITY UP TEMPORARILY...BUT IT SHOULD GO RIGHT BACK DOWN.
FOG SHOULD DISSIPATE WITH THE INCREASING TEMPERATURES IN THE
MORNING SO HAVE PUT OUT A DENSE FOG ADVISORY FOR THE WORST
AFFECTED AREAS UNTIL 10 AM.
TODAY THE EARLY MORNING CONVECTION IS LIKELY TO DISSIPATE IN THE
NEXT 3-6 HOURS...ESPECIALLY AS IT IS ALREADY SHOWING SIGNS OF
WEAKENING WITH WEAKER STORMS AND MORE STRATIFORM APPEARANCE ON
RADAR. IN COMBINATION WITH THE WEAKENING TREND AS STORMS MOVE
EAST...EXPECT US TO BE DOWN TO JUST SHOWERS BY SUNRISE OR SHORTLY
AFTER. HOWEVER...THIS IS UNLIKELY TO LAST AS INSTABILITY WILL BUILD
ONCE AGAIN AHEAD OF THE COLD FRONT AS IT SLOWLY MOVES INTO THE
WESTERN CWA THIS AFTERNOON. BETWEEN THAT AND THE RESPECTABLE SHEAR
THAT WILL BE OVER THE AREA THIS AFTERNOON WE SHOULD HAVE SOME STRONG
TO EVEN A FEW SEVERE STORMS THIS AFTERNOON AND EVENING AS THE FRONT
SAGS SLOWLY ACROSS NORTHERN MINNESOTA. THE FRONT SHOULD CONTINUE TO
SAG SOUTHEAST OVERNIGHT TONIGHT...AND CONTINUE ON INTO NORTHWEST
WISCONSIN FOR SUNDAY. HOWEVER...ON SUNDAY THE CONVERGENCE ALONG THE
BOUNDARY IS MUCH WEAKER...THE SHEAR IS MUCH WEAKER AS IS THE
INSTABILITY...SO DO NOT EXPECT AS MUCH INTENSITY OR COVERAGE FROM
THE STORMS AND HAVE GONE WITH LOWER POPS. OTHERWISE...TEMPERATURES
TO REMAIN SEASONABLE...WITH COOLER TEMPS NEAR THE LAKE AS USUAL.
EXPECT FOG AGAIN ACROSS THE AREA TONIGHT WITH THE RECENT RAINFALL
AND LIGHT WINDS...AND HAVE PUT IN AREAS OF FOG FOR A LARGE PORTION
OF THE AREA.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 320 AM CDT SAT AUG 8 2015
A WEAKENING UPPER LEVEL TROF IS FORECAST TO MOVE OUT OF THE AREA
SUNDAY EVENING...BUT NOT BEFORE DROPPING SOME RAIN ALONG THE
SOUTHERN EDGE OF THE REGION. THIS ACTIVITY WILL QUICKLY DEPART BY
06Z AND HAVE REMOVED THE POPS THEREAFTER AS HIGH PRESSURE IS
BUILDING IN. ON MONDAY...EVEN THOUGH HIGH PRESSURE COVERS THE
AREA...AN UPPER LEVEL TROF WILL SWING THROUGH THE ARROWHEAD AND HAVE
POPS TO REFLECT THIS. THE TROF MOVES EAST OF THE AREA MONDAY NIGHT
LEAVING THE SFC HIGH IN CHARGE. UPPER LEVEL RIDGING EDGES BACK
ACROSS THE REGION TUESDAY WHILE THE SFC HIGH REMAINS NEARBY. THE
RIDGING PREVAILS THROUGH WEDNESDAY. WEDNESDAY NIGHT FINDS A MID
LEVEL TROF MOVING ACROSS THE ARROWHEAD. THE GFS IS SUFFERING FROM
CONVECTIVE/GRIDSCALE FEEDBACK AND PUSHES A LARGE COLD FRONT INTO NE
MN. MEANWHILE...THE ECMWF HAS A WEAK SFC TROF ALONG THE CANADIAN
BORDER WITH SOME LIGHT QPF WITH THE GEM FURTHER TO THE WEST WITH THE
TROF AND NO RAIN. USED A BLEND OF THE GEM/ECMWF FOR POPS. MODEL
DIFFERENCES BECOME QUITE LARGE THURSDAY AND FRIDAY WITH THE HANDLING
OF AN UPPER TROF AND ASSOCIATED FRONTAL BOUNDARY. KEPT WITH THE
BLEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 106 AM CDT SAT AUG 8 2015
A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVE INTO THE NORTHLAND
DURING THE FORECAST PERIOD. THIS HAS GENERATED SHOWERS AND STORMS
OVER WESTERN AND NORTH CENTRAL MINNESOTA. CURRENTLY STORMS ARE
MOVING THROUGH KINL. EXPECTING THIS ACTIVITY TO SPREAD EASTWARDS
AND AFFECT ALL OTHER TERMINALS...EXCEPT FOR KHYR BETWEEN 07Z AND
12Z. THIS MATCHES WELL WITH THE CURRENT RADAR TRENDS ALONG WITH
THE LAST SEVERAL HRRR RUNS.
EXPECTING ALL TERMINALS TO SEE EITHER IFR OR LIFR CONDITIONS AT
SOME POINT AS THE NIGHT PROGRESSES INTO THE EARLY MORNING HOURS.
MOST CONFIDENT OF LIFR CIGS AND VISBYS FOR KDLH AND KHYR UNTIL 14Z
TO 17Z.
WILL SEE ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT
DUE TO DAY TIME HEATING IN COMBINATION WITH THE FRONT MOVING
THROUGH MINNESOTA SATURDAY AFTERNOON. THINK THAT KINL AND KBRD MAY
BE ON THE BACKSIDE OF THE FRONT BY THE TIME THIS OCCURS...SO LEFT
IN AS VCSH...AND EVENTUALLY BROUGHT KINL AND KBRD TO VFR
CONDITIONS BETWEEN 21Z AND 02Z. EXPECTING ALL OTHER TERMINALS TO
SEE SHOWERS AND STORMS DURING THE AFTERNOON...HOWEVER UNSURE ON
THE EXACT LOCATION OF SPECIFIC STORMS...SO LEFT AS VCTS. SOME OF
THESE STORMS MAY BE STRONG DURING THE AFTERNOON AND HEADING INTO
THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 72 60 78 58 / 40 50 10 10
INL 78 54 74 55 / 40 10 0 10
BRD 79 60 80 58 / 50 40 20 10
HYR 76 60 78 57 / 20 30 20 20
ASX 74 60 78 58 / 30 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001>003.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
LS...NONE.
&&
$$
SHORT TERM...LE
LONG TERM...GSF
AVIATION...WL
AREA FORECAST DISCUSSION
NWS DULUTH MN
106 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 106 AM CDT SAT AUG 8 2015
UPDATED AVIATION DISCUSSION BELOW FOR THE 06Z TAF ISSUANCE
UPDATE ISSUED AT 841 PM CDT FRI AUG 7 2015
WE WENT AHEAD AND ISSUED A DENSE FOG ADVISORY FOR THE TWIN PORTS
AND ALONG THE NORTH SHORE TONIGHT INTO SATURDAY MORNING.
VISIBILITIES CONTINUE TO DROP AND THAT TREND WILL CONTINUE
OVERNIGHT FOR MOST AREAS.
UPDATE ISSUED AT 807 PM CDT FRI AUG 7 2015
WE HAVE MADE SOME UPDATES TO ADJUST POPS/FOG/CLOUDS THIS EVENING.
A BROKEN LINE OF STORMS EXTENDED FROM SOUTHEAST MANITOBA INTO
EASTERN SOUTH DAKOTA THIS EVENING AND WAS MOVING TOWARD THE EAST.
THIS WAS OCCURRING IN AN AXIS OF MLCAPE AROUND 2000J/KG AND STEEP
LAPSE RATES. THE CONVECTION HAS SHOWN SOME SIGNS OF
WEAKENING AS IT PROGRESSES EAST...BUT A STRONG OR POSSIBLE
ISOLATED SEVERE STORM WILL BE POSSIBLE OVER OUR WESTERN ZONES
LATER THIS EVENING INTO THE EARLY MORNING HOURS.
FOG HAS PERSISTED AROUND LAKE SUPERIOR AND WE MAY HAVE TO ISSUE A
DENSE FOG ADVISORY FOR THE HEAD OF LAKE SUPERIOR NORTH ALONG
PORTIONS OF THE NORTH SHORE. SEVERAL OBSERVATIONS WERE DOWN TO A
QUARTER MILE. WE WILL WAIT A BIT LONGER BEFORE ISSUING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 344 PM CDT FRI AUG 7 2015
MAIN CONCERN FOR TODAY IS THE POTENTIAL FOR THUNDERSTORMS LATE THIS
AFTERNOON ACROSS NORTH-CENTRAL MINNESOTA...FOG OVERNIGHT...AND RAIN
CHANCES THROUGH THE DAY SATURDAY. EARLY THIS AFTERNOON AN UPPER LOW
EVIDENT ON WATER VAPOR SATELLITE IMAGERY WAS TRACKING ACROSS
SOUTHERN SASKATCHEWAN EAST INTO SOUTHERN MANITOBA. THIS UPPER LOW
AND ACCOMPANY SFC LOW WILL LIFT NORTHEAST INTO NORTHWESTERN ONTARIO
OVER THE WEEKEND. A WEAK COLD FRONT ASSOCIATED WITH THIS LOW IS
CURRENTLY OVER EASTERN NORTH DAKOTA AND WILL MOVE EAST INTO
NORTHWESTERN MINNESOTA TONIGHT...THEN STALL OUT THROUGH MUCH OF
SATURDAY AS IT IS DRAPED FROM LAKE OF THE WOODS IN NORTHERN
MINNESOTA TO AROUND FARGO NORTH DAKOTA. THIS COLD FRONT WILL SERVE
AS A BOUNDARY FOR ANY STORM INITIATION TONIGHT...AND AS A DRIVER FOR
SHOWERS AND STORMS AS THEY MOVE ACROSS THE REGION TOMORROW.
TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW NORMAL...ESPECIALLY
ALONG THE NORTH SHORE OF LAKE SUPERIOR.
LATE TODAY...CLEARING SKIES FROM WEST TO EAST. A CU FIELD WAS
OBSERVED ON VISIBLE SATELLITE EARLY THIS AFTERNOON...NOT SURPRISING
GIVEN THE INSTABILITY OVER NORTH CENTRAL MINNESOTA...MUCAPE VALUES
1500-2000 J/KG. IN ADDITION TO THE AFOREMENTIONED COLD FRONT
CURRENTLY OVER EASTERN NORTH DAKOTA...A WEAK STATIONARY FRONT IS
CURRENTLY ANALYZED FROM LAKE OF THE WOODS SOUTHEAST TO ABOUT MOOSE
LAKE. WHILE MUCH OF THE CWA REMAINS CAPPED...THERE IS A NARROW
CORRIDOR WHICH SPC MESOANALYSIS INDICATES HAS VERY LITTLE CIN
LEFT...BUT LACK OF ANY LOCAL FORCING MECHANISM WILL LIKELY PREVENT
ANY STORM DEVELOPMENT THROUGH THE AFTERNOON.
TONIGHT...AN ISOLATED STORM OR TWO WILL FIRE ACROSS THE RED RIVER
VALLEY THIS EVENING AND MOVE EAST INTO NORTH CENTRAL/NORTHEAST
MINNESOTA TOWARDS THE MORNING. COVERAGE EXPECTED TO BE SPARSE...BUT
WITH ELEVATED INSTABILITY AND 25-35 KTS DEEP LAYER SHEAR COULD SEE
STORMS SUSTAIN INTO THE NIGHT. STORMS MAY BE CAPABLE OF SMALL
HAIL/GUSTY WINDS...BUT SEVERE THREAT SHOULD BE MINIMAL. ELSEWHERE
EXPECT AREAS OF FOG TO DEVELOP ESPECIALLY NEAR LAKE SUPERIOR.
OVERNIGHT LOWS IN THE MID TO UPPER 50S.
SATURDAY...SCATTERED SHOWERS AND ISOLATED STORMS THROUGH THE DAY AND
INTO THE NIGHT AS A COLD FRONT MOVES THROUGH. SEVERE THUNDERSTORMS
NOT EXPECTED. NOT EXPECTING A COMPLETE WASHOUT...TRYING TO
COMMUNICATE THIS WITH THE USE OF JUST 40-60 PERCENT POPS AND AREAL
COVERAGE WORDING FOR THE WEATHER GRIDS...BUT A FEW DOWNPOURS
POSSIBLE. HIGHS IN THE 70S...EXPECT NEAR LAKE SUPERIOR WHERE HIGHS
WILL BE IN THE MID TO UPPER 60S.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 344 PM CDT FRI AUG 7 2015
VERY SLOW MOVING UPPER TROF AND ASSOCIATED LOW LEVEL FRONTAL ZONE
WILL MOVE ACROSS THE REGION SAT NITE/SUN BRINGING A CHANCE OF
SHOWERS/TSTORMS IN MOST AREAS. AT THIS TIME..IT APPEARS THAT THE
AXIS OF HIGHEST QUALITY LOW LEVEL MOISTURE WILL REMAIN SOUTH OF THE
DULUTH CWA. HOWEVER..THERE IS THE USUAL UNCERTAINTY IN
PLACEMENT/TIMING OF CONVECTIVE POTENTIAL THAT WILL BE LARGELY
DEPENDENT ON WHERE BOUNDARIES END UP AND OTHER CUMULATIVE EFFECTS
FROM SEVERAL ROUNDS OF CONVECTION BEFORE THIS TIME PERIOD. WITH A
WARM FRONTAL BOUNDARY PROGGED SOMEWHERE IN THE VICINITY OF THE I94
CORRIDOR AND THE NOSE OF A LLJ POINTED INTO WRN WI SAT NIGHT..THERE
APPEARS TO BE AT LEAST SOME POTENTIAL FOR HEAVY RAIN IN THE ERN HALF
OF OUR CWA SAT NIGHT INTO PERHAPS MIDDAY SUNDAY.
AT LEAST SOME LOW CHANCES FOR PRECIP ARE EXPECTED TO LINGER INTO
MONDAY AS THE FRONTAL ZONE IS EXPECTED TO TAKE ITS TIME MOVING
SOUTHEASTWARD. IT WILL LIKELY TAKE UNTIL SOMETIME MONDAY NIGHT WHEN
MORE SUBSTANTIAL LOW LEVEL RIDGING BUILDS BEFORE PRECIP WILL
COMPLETELY END. IN ADDITION..THERE COULD BE SOME SMALL RISK OF
SHOWERS ACROSS THE MN ARROWHEAD TUE..DEPENDING ON HOW COLD TEMPS GET
ALOFT.
THEREAFTER..HIGH PRESSURE SHOULD REMAIN IN CONTROL FOR MOST OF NEXT
WEEK..WITH WARM DAYS..AND COOL NIGHTS ESPECIALLY ACROSS INTERIOR NE
MINNESOTA. A WEAK FRONT INTERACTING WITH A BUILDING THERMAL RIDGE
COULD BRING SMALL CHANCES FOR TSTORMS TO NORTHERN MN WED NIGHT INTO
THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 106 AM CDT SAT AUG 8 2015
A FRONTAL BOUNDARY WILL CONTINUE TO SLOWLY MOVE INTO THE NORTHLAND
DURING THE FORECAST PERIOD. THIS HAS GENERATED SHOWERS AND STORMS
OVER WESTERN AND NORTH CENTRAL MINNESOTA. CURRENTLY STORMS ARE
MOVING THROUGH KINL. EXPECTING THIS ACTIVITY TO SPREAD EASTWARDS
AND AFFECT ALL OTHER TERMINALS...EXCEPT FOR KHYR BETWEEN 07Z AND
12Z. THIS MATCHES WELL WITH THE CURRENT RADAR TRENDS ALONG WITH
THE LAST SEVERAL HRRR RUNS.
EXPECTING ALL TERMINALS TO SEE EITHER IFR OR LIFR CONDITIONS AT
SOME POINT AS THE NIGHT PROGRESSES INTO THE EARLY MORNING HOURS.
MOST CONFIDENT OF LIFR CIGS AND VISBYS FOR KDLH AND KHYR UNTIL 14Z
TO 17Z.
WILL SEE ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT
DUE TO DAY TIME HEATING IN COMBINATION WITH THE FRONT MOVING
THROUGH MINNESOTA SATURDAY AFTERNOON. THINK THAT KINL AND KBRD MAY
BE ON THE BACKSIDE OF THE FRONT BY THE TIME THIS OCCURS...SO LEFT
IN AS VCSH...AND EVENTUALLY BROUGHT KINL AND KBRD TO VFR
CONDITIONS BETWEEN 21Z AND 02Z. EXPECTING ALL OTHER TERMINALS TO
SEE SHOWERS AND STORMS DURING THE AFTERNOON...HOWEVER UNSURE ON
THE EXACT LOCATION OF SPECIFIC STORMS...SO LEFT AS VCTS. SOME OF
THESE STORMS MAY BE STRONG DURING THE AFTERNOON AND HEADING INTO
THE EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 59 78 58 77 / 40 20 10 10
INL 53 76 53 75 / 20 10 10 10
BRD 60 81 58 79 / 40 20 10 10
HYR 59 78 57 77 / 30 40 20 10
ASX 59 79 57 76 / 40 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR WIZ001.
MN...DENSE FOG ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MNZ020-021-
037.
LS...NONE.
&&
$$
UPDATE...WL
SHORT TERM...JJM
LONG TERM...MILLER
AVIATION...WL
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1252 PM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 1033 AM CDT SAT AUG 8 2015
MCS REMNANTS HAVE BEEN STEADILY DECAYING ACROSS NORTH CENTRAL MO
AND CENTRAL MO. POPS HAVE BEEN REDUCED ACCORDINGLY.
KANOFSKY
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPAGATING SOUTHEAST INTO SOUTH CENTRAL
ILLINOIS ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH
THIS SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1234 PM CDT SAT AUG 8 2015
SPECIFICS FOR KUIN: LIGHT RAIN SHOWERS ARE POSSIBLE AT KUIN
THROUGH 08/19Z. INITIALLY EASTERLY WINDS WILL BECOME SOUTHEASTERLY
TO SOUTHERLY THROUGH THE PERIOD. A THUNDERSTORM COMPLEX IS
EXPECTED TO DEVELOP UPSTREAM OVERNIGHT AND REACH KUIN AFTER
09/06Z. THERE IS SOME UNCERTAINTY ON WHERE THE COMPLEX WILL FORM
AND WHEN IT MIGHT REACH KUIN.
SPECIFICS FOR KCOU: INITIALLY SOUTHEASTERLY WINDS WILL BECOME
SOUTHWESTERLY THROUGH THE TAF PERIOD IN RESPONSE TO AN APPROACHING
LOW PRESSURE CENTER. A THUNDERSTORM COMPLEX IS EXPECTED TO
DEVELOP UPSTREAM OVERNIGHT AND REACH KCOU AFTER 08/03Z. THERE IS
SOME UNCERTAINTY ON WHERE THE COMPLEX WILL FORM AND WHEN IT MIGHT
REACH KCOU.
SPECIFICS FOR KSTL, KSUS, KCPS: LIGHT WINDS HAVE BEEN SLOW TO
BECOME SOUTHEASTERLY THIS MORNING. LIGHT NORTHWEST TO WEST WINDS
MAY PERSIST FOR A FEW MORE HOURS BEFORE TURNING SOUTHEASTERLY IN
RESPONSE TO A DEVELOPING SURFACE LOW OVER KS. LIGHT WINDS AT KCOU
HAVE RECENTLY TURNED SOUTHEASTERLY, SUGGESTING THAT THE WIND
DIRECTION SHOULD FOLLOW SUIT AT ST. LOUIS METRO AREA TERMINALS
WITHIN THE NEXT 2-5 HOURS. A THUNDERSTORM COMPLEX IS EXPECTED TO
DEVELOP UPSTREAM OVERNIGHT AND PROGRESS SOUTHEASTWARDS, EVENTUALLY
REACHING THE TERMINALS AFTER 09/09Z.
KANOFSKY
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1250 PM CDT SAT AUG 8 2015
...AVIATION UPDATE...
.SHORT TERM...(Today through Sunday)
Issued at 305 AM CDT SAT AUG 08 2015
First concern is ongoing convection across northern Kansas.
Successive runs of the HRRR dissipates this area before it gets
into the forecast area as does the RAP. Given expanding ridging
would expect it to dissipate as it gets closer and stay north of
the area. Will monitor radar trends and update as needed. For now
will keep dry forecast for the morning hours.
Attention then turns to the aforementioned expanding ridge across
the area. This ridge will dominate the weather through Sunday with
increasing heat and humidity. Heat advisory already in effect for
much of the area from this afternoon through Sunday evening. Expect
afternoon heat indicies in the 100 to 110 degree range both days.
Biggest question will be the need to expand the advisory further
eastward. Eastern Ozarks best chance to hit advisory criteria would
be Sunday afternoon. Will allow day shift to evaluate it further.
.LONG TERM...(Sunday night through Friday)
Issued at 305 AM CDT SAT AUG 08 2015
Upper ridge retracts westward Sunday night and Monday allowing for a
surface frontal boundary to slip southward into the area. This will
bring our next chance for rain. Medium range models showing the
better chances across central Missouri from late Sunday night into
Monday morning.
Pattern then dominated by a northwest flow regime with a surface
high building southward into the area. This will result in quiet
and dry weather with near to slightly below normal temperatures.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Pilots flying in and out of the southwest Missouri airports will
experience VFR conditions over the next 24 hours.
Southeast surface winds will be common as cloud cover begins to
clear out for the rest of today and tonight.
Thunderstorms will once again develop tonight, however, they are
expected to remain north of the Ozarks.
Safe Travels.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 10 PM CDT Sunday for MOZ055-056-066>069-
077>081-088>096-101>105.
KS...HEAT ADVISORY until 10 PM CDT Sunday for KSZ073-097-101.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Cramer
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1231 PM CDT SAT AUG 8 2015
.DISCUSSION...
Issued at 357 AM CDT SAT AUG 8 2015
As was anticipated last night, High Plains convection has congealed
into an overnight MCS, which has made pretty good progression across
northern Kansas, into north central Kansas. Models have had a rough
time resolving exactly how this MCS will behave as it continues east.
NAM consistently indicates that this complex will lose steam as the
night progresses, but HRRR continues to insist that the complex will
continue it, albeit weakening along the way, into the KC metro around
sunrise. General thought as the morning progresses is a bit in the
middle between these two solutions. The low level jet, apparently
helping this complex persist is not very strong, but it also doesn`t
appear to weaken much as one gets closer to the KC Metro. However,
with the outflow from these storms already pushing out ahead of the
complex, there is a good bet that stabilization of the effective
layer will gradually occur and the storms will eventually lose their
strength. Have the best chance of rain occurring across the far
northwestern part of the CWA, in NW Missouri and NE Kansas, with
diminishing (but non-zero) chances farther south and east.
The focus then shifts to a complicated and conditional forecast for
Saturday. Heat headlines currently ongoing will be allowed to
continue, however confidence in these abnormally hot temperatures
isn`t quite as high as it was yesterday. The aforementioned storm
complex could change the evolution of the heat today across a good
portion of the area. If the HRRR has its way and the complex dives
all the way into the KC Metro it would bring at least some rain into
the morning hours, with likely some cloud debris lingering around
for a good portion of the morning. Even with all these qualifiers
it`s still anticipated that the surface will recover, despite the
stable rain cooled air moving through this morning. Expect heat
indices to jump into the 100 to 105 range this afternoon with some
locations perhaps reaching a little higher, mainly along and south
of the MO River.
That leads to the complications and conditions related to the storm
chances later this afternoon and this evening. Mid level flow
continues to reside over the central and northern plains with the
center of the mid level ridge well south of the forecast area in the
eastern southern plains. At the surface an unseasonably deep trough
will form across the central High Plains and eject into the lower
central plains. In response to this low to the west S/SE winds will
pick up during the day, and likely overcome the cooler air, causing
temperatures to jump back into the upper 80s, and very possibly the
lower 90s. Across far northern Missouri, where cloud debris will
likely be the thickest, as well as perhaps along or north of the
warm front temperatures won`t get quite as warm as areas along and
south of I-70. Depending on how well skies clear out this afternoon
another round of storms will be possible, most likely across SE
Nebraska, eastward across northern Missouri and southern Iowa. Most
models continue to indicate a scenario where storms indeed fire
later today. The lack of any appreciable mid level support for
ascent this afternoon will exaggerate the capping inversion, which
will keep storms at bay for at least the afternoon, into the evening
hours. By the 22z to 00z time period the low level jet at 850 mb
will pick up in intensity and likely give the final push needed to
get storms to go up, likely in SE Nebraska or NE Kansas. Should these
storms become surface based, which isn`t out of the question, a very
impressive thermal and wind profile will be in place to bring some
powerful storms. With the aforementioned SE surface flow, the
strengthening LLJ, as well as the westerly mid level flow around 40
kts. The wind profile will be ample for supercell storms to form
later this evening in the SE Neb/NW Mo/NE Ks area. ML CAPE values
approaching 2000 to 3000 J/KG will provide the necessary instability
to complement the deep layer shear nicely. Given that supercells are
possible, hail and wind would be the most likely hazards with these
storms; however not to be discounted, very impressive hodographs are
present across the area of concern, with very long and clockwise
curved hodographs. This would introduce a rather concerning tornado
risk, especially for early August. Given the weak forcing it`s
certainly possible that early storms will be somewhat discreet,
which would increase the concern for supercellular storms. However,
by 00z to 03z the discreet storms will likely congeal into a more
robust complex and drive eastward, likely along the MO/IA border,
bringing a wind and hail threat, along with a flash flooding threat.
Given the LLJ maintenance overnight and PWAT values approaching 2 to
2.5 inches it`s possible that areas along and north of HWY 36
tonight could see some flooding and/or flash flooding. By early
Sunday morning expect these storms to have moved off to the east and
chances for rain gradually diminishing through the day on Sunday.
For Sunday, warm conditions will continue for the forecast area,
again, mainly across the southern zones. Anticipate temperatures
again to reach the 90s, with heat indices in the 100 to 105 range
across areas along and south of the MO River. But again, depending
on how the area clears, the areal extent of the heat for Sunday is a
bit up in the air, so will forgo a heat headline for now, but one
may be necessary for areas along and south of the MO River.
For Sunday, into Monday the large ridge will shift a little back to
the west, putting the forecast area under more of an influence of
the large trough over the Great Lakes region as opposed to the
western ridge. A short wave trough will glide through the area on
Monday, which should bring another chance for some rain, as well as
a cooler air mass. For the rest of the week, expect temperatures to
be a bit more comfortable with temperatures generally in the 80s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1231 PM CDT SAT AUG 8 2015
Main concerns with afternoon forecast involve possibilities for
renewed convection later today/evening as a seasonably strong sfc
low tracks east from the central High Plains. Current thinking is
main show will remain north of Kansas City terminals later
tonight...with main threats confined to STJ after the 00z time
frame. Considering the amount of uncertainty on just where convection
does form...have decided to offer a VCTS mention at STJ beginning at
2z or so. Once convective trends are better established...updates
will be issued accordingly. Otherwise...expect VFR conditions at
remaining sites with southeast winds eventually becoming southwest
after 12z Sunday morning.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 9 PM CDT this evening for KSZ025-057-060-102.
EXCESSIVE HEAT WARNING until 9 PM CDT this evening for
KSZ103>105.
MO...HEAT ADVISORY until 9 PM CDT this evening for MOZ011>014-020>023-
030-031-038-039-043>046-053-054.
EXCESSIVE HEAT WARNING until 9 PM CDT this evening for MOZ028-
029-037.
&&
$$
DISCUSSION...Leighton
AVIATION...32
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1036 AM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 1033 AM CDT SAT AUG 8 2015
MCS REMNANTS HAVE BEEN STEADILY DECAYING ACROSS NORTH CENTRAL MO
AND CENTRAL MO. POPS HAVE BEEN REDUCED ACCORDINGLY.
KANOFSKY
&&
ISSUED AT 434 AM CDT SAT AUG 8 2015
WILL BE ISSUING A DENSE FOG ADVISORY THROUGH 13Z FOR THE SOUTHERN
MISSOURI COUNTIES IN THE CWA WHERE THE VISIBILITY HAS DROPPED TO
1/4SM. HAVE ALSO ADJUSTED POPS UP TO LIKELY CATEGORY FOR THE
NORTHERN CWA WHERE REMNANTS OF THE MCS WILL BE TRACKING THIS
MORNING.
CVKING
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM CDT SAT AUG 8 2015
LOW VSBYS IN FOG SHOULD IMPROVE OVER THE NEXT HOUR OR TWO TO VFR.
UNTIL THEN...MVFR AND IFR VSBYS WILL PREVAIL ACROSS PARTS OF
EASTERN AND CENTRAL MISSOURI. ADDITIONALLY...LIGHT SHOWERS
CURRENTLY OVER WESTERN MISSOURI WILL LIKELY DRIFT INTO PARTS OF
NORTHEAST MISSOURI BETWEEN 14Z AND 16Z. DON`T EXPECT MUCH IMPACT
FROM THIS LIGHT RAIN OTHER THAN WET RUNWAYS. ONCE FOG DISSIPATES
AND RAIN EVAPORATES EXPECT VFR FLIGHT CONDITIONS TO PREVAIL INTO
THE EVENING HOURS. ANOTHER COMPLEX OF STORMS IS EXPECTED TO FORM
TONIGHT OVER IOWA AND THE SOUTHERN FRINGES OF THE COMPLEX WILL
LIKELY IMPACT NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS AFTER
06Z.
SPECIFICS FOR KSTL:
VFR FLIGHT CONDITIONS AND LIGHT SOUTHEAST FLOW IS EXPECTED TO
PREVAIL AT LAMBERT AT LEAST THROUGH TONIGHT. THERE IS A SLIGHT
CHANCE OF ISOLATED THUNDERSTORMS LATE THIS AFTERNOON, BUT IF ANY
STORMS DO FORM THE AREAL COVERAGE IS EXPECTED TO BE VERY LOW.
THERE IS ANOTHER CHANCE FOR STORMS EARLY SUNDAY MORNING, BUT
CONFIDENCE IN THE THUNDERSTORM TRENDS IS LOW AT THIS TIME SO HAVE
LEFT MENTION OF STORMS OUR FOR NOW.
CARNEY
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 90 76 95 75 / 20 20 30 40
QUINCY 84 71 89 70 / 40 60 40 20
COLUMBIA 90 75 94 72 / 40 20 20 40
JEFFERSON CITY 91 76 96 74 / 30 20 20 40
SALEM 87 72 91 73 / 10 10 30 40
FARMINGTON 88 72 94 74 / 10 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
717 AM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 434 AM CDT SAT AUG 8 2015
WILL BE ISSUING A DENSE FOG ADVISORY THROUGH 13Z FOR THE SOUTHERN
MISSOURI COUNTIES IN THE CWA WHERE THE VISIBILITY HAS DROPPED TO
1/4SM. HAVE ALSO ADJUSTED POPS UP TO LIKELY CATEGORY FOR THE
NORTHERN CWA WHERE REMNANTS OF THE MCS WILL BE TRACKING THIS
MORNING.
CVKING
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM CDT SAT AUG 8 2015
LOW VSBYS IN FOG SHOULD IMPROVE OVER THE NEXT HOUR OR TWO TO VFR.
UNTIL THEN...MVFR AND IFR VSBYS WILL PREVAIL ACROSS PARTS OF
EASTERN AND CENTRAL MISSOURI. ADDITIONALLY...LIGHT SHOWERS
CURRENTLY OVER WESTERN MISSOURI WILL LIKELY DRIFT INTO PARTS OF
NORTHEAST MISSOURI BETWEEN 14Z AND 16Z. DON`T EXPECT MUCH IMPACT
FROM THIS LIGHT RAIN OTHER THAN WET RUNWAYS. ONCE FOG DISSIPATES
AND RAIN EVAPORATES EXPECT VFR FLIGHT CONDITIONS TO PREVAIL INTO
THE EVENING HOURS. ANOTHER COMPLEX OF STORMS IS EXPECTED TO FORM
TONIGHT OVER IOWA AND THE SOUTHERN FRINGES OF THE COMPLEX WILL
LIKELY IMPACT NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS AFTER
06Z.
SPECIFICS FOR KSTL:
VFR FLIGHT CONDITIONS AND LIGHT SOUTHEAST FLOW IS EXPECTED TO
PREVAIL AT LAMBERT AT LEAST THROUGH TONIGHT. THERE IS A SLIGHT
CHANCE OF ISOLATED THUNDERSTORMS LATE THIS AFTERNOON, BUT IF ANY
STORMS DO FORM THE AREAL COVERAGE IS EXPECTED TO BE VERY LOW.
THERE IS ANOTHER CHANCE FOR STORMS EARLY SUNDAY MORNING, BUT
CONFIDENCE IN THE THUNDERSTORM TRENDS IS LOW AT THIS TIME SO HAVE
LEFT MENTION OF STORMS OUR FOR NOW.
CARNEY
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 90 76 95 75 / 20 20 30 40
QUINCY 84 71 89 70 / 70 60 40 20
COLUMBIA 90 75 94 72 / 40 20 20 40
JEFFERSON CITY 91 76 96 74 / 30 20 20 40
SALEM 87 72 91 73 / 20 10 30 40
FARMINGTON 88 72 94 74 / 10 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR CRAWFORD MO-
IRON MO-MADISON MO-REYNOLDS MO-ST. FRANCOIS MO-STE.
GENEVIEVE MO-WASHINGTON MO.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
634 AM CDT SAT AUG 8 2015
.DISCUSSION...
Issued at 357 AM CDT SAT AUG 8 2015
As was anticipated last night, High Plains convection has congealed
into an overnight MCS, which has made pretty good progression across
northern Kansas, into north central Kansas. Models have had a rough
time resolving exactly how this MCS will behave as it continues east.
NAM consistently indicates that this complex will lose steam as the
night progresses, but HRRR continues to insist that the complex will
continue it, albeit weakening along the way, into the KC metro around
sunrise. General thought as the morning progresses is a bit in the
middle between these two solutions. The low level jet, apparently
helping this complex persist is not very strong, but it also doesn`t
appear to weaken much as one gets closer to the KC Metro. However,
with the outflow from these storms already pushing out ahead of the
complex, there is a good bet that stabilization of the effective
layer will gradually occur and the storms will eventually lose their
strength. Have the best chance of rain occurring across the far
northwestern part of the CWA, in NW Missouri and NE Kansas, with
diminishing (but non-zero) chances farther south and east.
The focus then shifts to a complicated and conditional forecast for
Saturday. Heat headlines currently ongoing will be allowed to
continue, however confidence in these abnormally hot temperatures
isn`t quite as high as it was yesterday. The aforementioned storm
complex could change the evolution of the heat today across a good
portion of the area. If the HRRR has its way and the complex dives
all the way into the KC Metro it would bring at least some rain into
the morning hours, with likely some cloud debris lingering around
for a good portion of the morning. Even with all these qualifiers
it`s still anticipated that the surface will recover, despite the
stable rain cooled air moving through this morning. Expect heat
indices to jump into the 100 to 105 range this afternoon with some
locations perhaps reaching a little higher, mainly along and south
of the MO River.
That leads to the complications and conditions related to the storm
chances later this afternoon and this evening. Mid level flow
continues to reside over the central and northern plains with the
center of the mid level ridge well south of the forecast area in the
eastern southern plains. At the surface an unseasonably deep trough
will form across the central High Plains and eject into the lower
central plains. In response to this low to the west S/SE winds will
pick up during the day, and likely overcome the cooler air, causing
temperatures to jump back into the upper 80s, and very possibly the
lower 90s. Across far northern Missouri, where cloud debris will
likely be the thickest, as well as perhaps along or north of the
warm front temperatures won`t get quite as warm as areas along and
south of I-70. Depending on how well skies clear out this afternoon
another round of storms will be possible, most likely across SE
Nebraska, eastward across northern Missouri and southern Iowa. Most
models continue to indicate a scenario where storms indeed fire
later today. The lack of any appreciable mid level support for
ascent this afternoon will exaggerate the capping inversion, which
will keep storms at bay for at least the afternoon, into the evening
hours. By the 22z to 00z time period the low level jet at 850 mb
will pick up in intensity and likely give the final push needed to
get storms to go up, likely in SE Nebraska or NE Kansas. Should these
storms become surface based, which isn`t out of the question, a very
impressive thermal and wind profile will be in place to bring some
powerful storms. With the aforementioned SE surface flow, the
strengthening LLJ, as well as the westerly mid level flow around 40
kts. The wind profile will be ample for supercell storms to form
later this evening in the SE Neb/NW Mo/NE Ks area. ML CAPE values
approaching 2000 to 3000 J/KG will provide the necessary instability
to complement the deep layer shear nicely. Given that supercells are
possible, hail and wind would be the most likely hazards with these
storms; however not to be discounted, very impressive hodographs are
present across the area of concern, with very long and clockwise
curved hodographs. This would introduce a rather concerning tornado
risk, especially for early August. Given the weak forcing it`s
certainly possible that early storms will be somewhat discreet,
which would increase the concern for supercellular storms. However,
by 00z to 03z the discreet storms will likely congeal into a more
robust complex and drive eastward, likely along the MO/IA border,
bringing a wind and hail threat, along with a flash flooding threat.
Given the LLJ maintenance overnight and PWAT values approaching 2 to
2.5 inches it`s possible that areas along and north of HWY 36
tonight could see some flooding and/or flash flooding. By early
Sunday morning expect these storms to have moved off to the east and
chances for rain gradually diminishing through the day on Sunday.
For Sunday, warm conditions will continue for the forecast area,
again, mainly across the southern zones. Anticipate temperatures
again to reach the 90s, with heat indices in the 100 to 105 range
across areas along and south of the MO River. But again, depending
on how the area clears, the areal extent of the heat for Sunday is a
bit up in the air, so will forgo a heat headline for now, but one
may be necessary for areas along and south of the MO River.
For Sunday, into Monday the large ridge will shift a little back to
the west, putting the forecast area under more of an influence of
the large trough over the Great Lakes region as opposed to the
western ridge. A short wave trough will glide through the area on
Monday, which should bring another chance for some rain, as well as
a cooler air mass. For the rest of the week, expect temperatures to
be a bit more comfortable with temperatures generally in the 80s.
&&
.AVIATION...(For the 12Z TAFS through 12Z Sunday Morning)
Issued at 629 AM CDT SAT AUG 8 2015
Morning showers and thunderstorms will likely move out of the area by
mid morning, with VFR conditions prevailing. Winds will pick up out
of the southeast by mid to late morning around 15 to 20 kts. KSTJ
could see some thunderstorm activity later tonight, but the bulk of
it should remain north of KSTJ nearer to the IA/MO border.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY from Noon today to 9 PM CDT this evening for
KSZ025-057-060-102.
EXCESSIVE HEAT WARNING from Noon today to 9 PM CDT this evening
for KSZ103>105.
MO...HEAT ADVISORY from Noon today to 9 PM CDT this evening for
MOZ011>014-020>023-030-031-038-039-043>046-053-054.
EXCESSIVE HEAT WARNING from Noon today to 9 PM CDT this evening
for MOZ028-029-037.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
437 AM CDT SAT AUG 8 2015
.UPDATE:
ISSUED AT 434 AM CDT SAT AUG 8 2015
WILL BE ISSUING A DENSE FOG ADVISORY THROUGH 13Z FOR THE SOUTHERN
MISSOURI COUNTIES IN THE CWA WHERE THE VISIBILITY HAS DROPPED TO
1/4SM. HAVE ALSO ADJUSTED POPS UP TO LIKELY CATEGORY FOR THE
NORTHERN CWA WHERE REMNANTS OF THE MCS WILL BE TRACKING THIS
MORNING.
CVKING
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1055 PM CDT FRI AUG 7 2015
WEAKENING COLD FRONT EXTENDING FROM A SURFACE LOW OVER WI SW INTO
NORTHEAST MO WILL CONTINUE MOVING SOUTHEASTWARD LATE TONIGHT AND
DISSIPATE. COULD NOT RULE OUT AN ISOLATED SHOWER/STORM ALONG THIS
WEAK FRONT...BUT FOR NOW WILL LEAVE UIN TAF DRY. HIGH LEVEL
CLOUDINESS WILL STREAM EASTWARD FROM THE PLAINS LATE TONIGHT...
MAINLY FROM CONVECTION ACROSS KANSAS AND NEBRASKA. WITH LIGHT
SURFACE WINDS AND RELATIVELY HIGH SURFACE DEW POINTS...THERE MAY
BE SOME FOG LATE TONIGHT/EARLY SATURDAY MORNING...ALTHOUGH THE NAM
MOS GUIDANCE APPEARS OVERDONE ON ITS STRATUS/FOG FORECAST AT THE
TAF SITES. SOUTHEASTERLY SURFACE WINDS ON SATURDAY WITH SCATTERED
DIURNAL CUMULUS ALONG WITH HIGH LEVEL CLOUDS AGAIN.
SPECIFICS FOR KSTL: SOME HIGH LEVEL CLOUDS FOR LATE TONIGHT.
LIGHT E-SELY SURFACE WIND LATE TONIGHT WILL STRENGTHEN TO AROUND
7-8 KNOTS SATURDAY AFTERNOON. SCATTERED DIURNAL CUMULUS CLOUDS
WILL DEVELOP AGAIN FOR LATE SATURDAY MORNING AND AFTERNOON.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 91 76 95 75 / 10 20 30 40
QUINCY 87 71 89 70 / 50 60 40 20
COLUMBIA 90 75 94 72 / 30 20 20 40
JEFFERSON CITY 91 76 96 74 / 20 20 20 40
SALEM 87 72 91 73 / 10 10 30 40
FARMINGTON 88 72 94 74 / 5 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
358 AM CDT SAT AUG 8 2015
.DISCUSSION...
Issued at 357 AM CDT SAT AUG 8 2015
As was anticipated last night, High Plains convection has congealed
into an overnight MCS, which has made pretty good progression across
northern Kansas, into north central Kansas. Models have had a rough
time resolving exactly how this MCS will behave as it continues east.
NAM consistently indicates that this complex will lose steam as the
night progresses, but HRRR continues to insist that the complex will
continue it, albeit weakening along the way, into the KC metro around
sunrise. General thought as the morning progresses is a bit in the
middle between these two solutions. The low level jet, apparently
helping this complex persist is not very strong, but it also doesn`t
appear to weaken much as one gets closer to the KC Metro. However,
with the outflow from these storms already pushing out ahead of the
complex, there is a good bet that stabilization of the effective
layer will gradually occur and the storms will eventually lose their
strength. Have the best chance of rain occurring across the far
northwestern part of the CWA, in NW Missouri and NE Kansas, with
diminishing (but non-zero) chances farther south and east.
The focus then shifts to a complicated and conditional forecast for
Saturday. Heat headlines currently ongoing will be allowed to
continue, however confidence in these abnormally hot temperatures
isn`t quite as high as it was yesterday. The aforementioned storm
complex could change the evolution of the heat today across a good
portion of the area. If the HRRR has its way and the complex dives
all the way into the KC Metro it would bring at least some rain into
the morning hours, with likely some cloud debris lingering around
for a good portion of the morning. Even with all these qualifiers
it`s still anticipated that the surface will recover, despite the
stable rain cooled air moving through this morning. Expect heat
indices to jump into the 100 to 105 range this afternoon with some
locations perhaps reaching a little higher, mainly along and south
of the MO River.
That leads to the complications and conditions related to the storm
chances later this afternoon and this evening. Mid level flow
continues to reside over the central and northern plains with the
center of the mid level ridge well south of the forecast area in the
eastern southern plains. At the surface an unseasonably deep trough
will form across the central High Plains and eject into the lower
central plains. In response to this low to the west S/SE winds will
pick up during the day, and likely overcome the cooler air, causing
temperatures to jump back into the upper 80s, and very possibly the
lower 90s. Across far northern Missouri, where cloud debris will
likely be the thickest, as well as perhaps along or north of the
warm front temperatures won`t get quite as warm as areas along and
south of I-70. Depending on how well skies clear out this afternoon
another round of storms will be possible, most likely across SE
Nebraska, eastward across northern Missouri and southern Iowa. Most
models continue to indicate a scenario where storms indeed fire
later today. The lack of any appreciable mid level support for
ascent this afternoon will exaggerate the capping inversion, which
will keep storms at bay for at least the afternoon, into the evening
hours. By the 22z to 00z time period the low level jet at 850 mb
will pick up in intensity and likely give the final push needed to
get storms to go up, likely in SE Nebraska or NE Kansas. Should these
storms become surface based, which isn`t out of the question, a very
impressive thermal and wind profile will be in place to bring some
powerful storms. With the aforementioned SE surface flow, the
strengthening LLJ, as well as the westerly mid level flow around 40
kts. The wind profile will be ample for supercell storms to form
later this evening in the SE Neb/NW Mo/NE Ks area. ML CAPE values
approaching 2000 to 3000 J/KG will provide the necessary instability
to complement the deep layer shear nicely. Given that supercells are
possible, hail and wind would be the most likely hazards with these
storms; however not to be discounted, very impressive hodographs are
present across the area of concern, with very long and clockwise
curved hodographs. This would introduce a rather concerning tornado
risk, especially for early August. Given the weak forcing it`s
certainly possible that early storms will be somewhat discreet,
which would increase the concern for supercellular storms. However,
by 00z to 03z the discreet storms will likely congeal into a more
robust complex and drive eastward, likely along the MO/IA border,
bringing a wind and hail threat, along with a flash flooding threat.
Given the LLJ maintenance overnight and PWAT values approaching 2 to
2.5 inches it`s possible that areas along and north of HWY 36
tonight could see some flooding and/or flash flooding. By early
Sunday morning expect these storms to have moved off to the east and
chances for rain gradually diminishing through the day on Sunday.
For Sunday, warm conditions will continue for the forecast area,
again, mainly across the southern zones. Anticipate temperatures
again to reach the 90s, with heat indices in the 100 to 105 range
across areas along and south of the MO River. But again, depending
on how the area clears, the areal extent of the heat for Sunday is a
bit up in the air, so will forgo a heat headline for now, but one
may be necessary for areas along and south of the MO River.
For Sunday, into Monday the large ridge will shift a little back to
the west, putting the forecast area under more of an influence of
the large trough over the Great Lakes region as opposed to the
western ridge. A short wave trough will glide through the area on
Monday, which should bring another chance for some rain, as well as
a cooler air mass. For the rest of the week, expect temperatures to
be a bit more comfortable with temperatures generally in the 80s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1203 AM CDT SAT AUG 8 2015
Mainly VFR expected through the period. Main concern will be
potential thunderstorm complex reaching terminals in some weakened
form between 09-14Z. Still expect mainly VFR conditions with this
activity. Cloud canopy currently overspreading region will limit
shallow fog potential. Otherwise, southeast winds will increase to
AOA 12kts by mid- morning. Additional chances for storms during the
afternoon/evening look to remain north of terminals through TAF
period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY from 11 AM this morning to 9 PM CDT this evening
for KSZ025-057-060-102.
EXCESSIVE HEAT WARNING from 11 AM this morning to 9 PM CDT this
evening for KSZ103>105.
MO...HEAT ADVISORY from 11 AM this morning to 9 PM CDT this evening
for MOZ011>014-020>023-030-031-038-039-043>046-053-054.
EXCESSIVE HEAT WARNING from 11 AM this morning to 9 PM CDT this
evening for MOZ028-029-037.
&&
$$
DISCUSSION...Leighton
AVIATION...Blair
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
305 AM CDT SAT AUG 8 2015
.SHORT TERM...(Today through Sunday)
Issued at 305 AM CDT SAT AUG 08 2015
First concern is ongoing convection across northern Kansas.
Successive runs of the HRRR dissipates this area before it gets
into the forecast area as does the RAP. Given expanding ridging
would expect it to dissipate as it gets closer and stay north of
the area. Will monitor radar trends and update as needed. For now
will keep dry forecast for the morning hours.
Attention then turns to the aforementioned expanding ridge across
the area. This ridge will dominate the weather through Sunday with
increasing heat and humidity. Heat advisory already in effect for
much of the area from this afternoon through Sunday evening. Expect
afternoon heat indicies in the 100 to 110 degree range both days.
Biggest question will be the need to expand the advisory further
eastward. Eastern Ozarks best chance to hit advisory criteria would
be Sunday afternoon. Will allow day shift to evaluate it further.
.LONG TERM...(Sunday night through Friday)
Issued at 305 AM CDT SAT AUG 08 2015
Upper ridge retracts westward Sunday night and Monday allowing for a
surface frontal boundary to slip southward into the area. This will
bring our next chance for rain. Medium range models showing the
better chances across central Missouri from late Sunday night into
Monday morning.
Pattern then dominated by a northwest flow regime with a surface
high building southward into the area. This will result in quiet
and dry weather with near to slightly below normal temperatures.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1133 PM CDT FRI AUG 07 2015
Generally VFR conditions are expected at area terminals tonight
through Saturday. The exception may be patchy light fog late
tonight into early Friday morning which could lead to a brief
interval of MVFR visibilities. Otherwise a light southerly wind
will develop Saturday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY from Noon today to 10 PM CDT Sunday for MOZ055-056-
066>069-077>081-088>096-101>105.
KS...HEAT ADVISORY from Noon today to 10 PM CDT Sunday for KSZ073-097-
101.
&&
$$
SHORT TERM...Raberding
LONG TERM...Raberding
AVIATION...Foster
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
256 AM CDT SAT AUG 8 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 255 AM CDT SAT AUG 8 2015
MCS OVER EASTERN NEBRASKA AND NORTH CENTRAL KANSAS IS FORECAST TO
DECAY AS IT MOVES EAST TODAY. HAVE INTRODUCED SOME SLIGHT CHANCE
POPS INTO THE FORECAST FOR TODAY ALONG AND NORTH OF I-70 AS LATEST
RUNS OF HRRR SUGGEST TAIL END OF THE DECAYING SYSTEM COULD BRING
SOME ISOLATED TO SCATTERED SHOWERS/STORMS ACROSS THE AREA THIS
MORNING AND EARLY AFTERNOON. TEMPERATURES ARE GOING TO BE TRICKY
WITH CONVECTIVE DEBRIS CLOUD COVER. HAVE DECIDED TO STICK WITH A
HEALTHY BLEND OF THE LATEST GUIDANCE AND LET THE DAY SHIFT ADJUST IF
CLOUD COVER AND PRECIPITATION LIMIT INSOLATION.
CVKING
.LONG TERM: (TONIGHT THROUGH FRIDAY)
ISSUED AT 255 AM CDT SAT AUG 8 2015
THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND EVENING
TO THE NORTHWEST OF THE CWA AND GROW UPSCALE INTO ANOTHER MCS. THE
TRACK OF THE SYSTEM IS STILL FORECAST TO JUST GRAZE THE NORTHERN CWA
TONIGHT...POSSIBLY PROPOGATING SOUTHEAST INTO SOUTH CENTRAL ILLINOIS
ON SUNDAY MORNING. SEVERE WEATHER THREAT ASSOCIATED WITH THIS
SYSTEM IS DAMAGING WIND GUSTS IN EXCESS OF 60 MPH.
ANOTHER STRUGGLE BETWEEN CONVECTIVE DEBRIS AND VERY WARM
TEMPERATURES ALOFT RESULTS IN A LOW CONFIDENCE TEMPERATURE FORECAST
FOR SUNDAY. POTENTIAL IS CERTAINLY THERE FOR A HOT AND STEAMY DAY
WITH HEAT INDEX VALUES ABOVE 105 DEGREES IN THE AFTERNOON AND
EVENING. WILL CONTINUE TO HIGHLIGHT IN THE HWO AND ALLOW DAYSHIFT
ANOTHER SET OF MODEL RUNS BEFORE ISSUING ANY HEADLINES FOR HEAT ON
SUNDAY.
CONVECTION SHOULD REDEVELOP AGAIN SUNDAY AFTERNOON AND CONTINUE INTO
THE NIGHT...PROBABLY INITIALLY ON THE OUTFLOW BOUNDARY FROM THE
MORNING MCS AND THEN THE COLD FRONT SETTLING SOUTH ACROSS THE
REGION. HAVE KEPT HIGH CHANCE POPS BUT COULD SEE LATER SHIFTS
INCREASING TO LIKELY.
REMAINDER OF THE FORECAST FEATURES SLIGHTLY BELOW NORMAL
TEMPERATURES AND DRY CONDITIONS AS NORTH TO NORTHWEST FLOW CONTINUES
TO DELIVER HIGH PRESSURE TO THE REGION.
CVKING
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1055 PM CDT FRI AUG 7 2015
WEAKENING COLD FRONT EXTENDING FROM A SURFACE LOW OVER WI SW INTO
NORTHEAST MO WILL CONTINUE MOVING SOUTHEASTWARD LATE TONIGHT AND
DISSIPATE. COULD NOT RULE OUT AN ISOLATED SHOWER/STORM ALONG THIS
WEAK FRONT...BUT FOR NOW WILL LEAVE UIN TAF DRY. HIGH LEVEL
CLOUDINESS WILL STREAM EASTWARD FROM THE PLAINS LATE TONIGHT...
MAINLY FROM CONVECTION ACROSS KANSAS AND NEBRASKA. WITH LIGHT
SURFACE WINDS AND RELATIVELY HIGH SURFACE DEW POINTS...THERE MAY
BE SOME FOG LATE TONIGHT/EARLY SATURDAY MORNING...ALTHOUGH THE NAM
MOS GUIDANCE APPEARS OVERDONE ON ITS STRATUS/FOG FORECAST AT THE
TAF SITES. SOUTHEASTERLY SURFACE WINDS ON SATURDAY WITH SCATTERED
DIURNAL CUMULUS ALONG WITH HIGH LEVEL CLOUDS AGAIN.
SPECIFICS FOR KSTL: SOME HIGH LEVEL CLOUDS FOR LATE TONIGHT.
LIGHT E-SELY SURFACE WIND LATE TONIGHT WILL STRENGTHEN TO AROUND
7-8 KNOTS SATURDAY AFTERNOON. SCATTERED DIURNAL CUMULUS CLOUDS
WILL DEVELOP AGAIN FOR LATE SATURDAY MORNING AND AFTERNOON.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 91 76 95 75 / 10 20 30 40
QUINCY 87 71 89 70 / 20 60 40 20
COLUMBIA 90 75 94 72 / 10 20 20 40
JEFFERSON CITY 91 76 96 74 / 10 20 20 40
SALEM 87 72 91 73 / 10 10 30 40
FARMINGTON 88 72 94 74 / 10 10 20 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
614 PM CDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
CHANCE FOR THUNDERSTORMS AND THEIR SEVERITY TONIGHT ARE THE PRIMARY
FORECAST CONCERNS.
THUNDERSTORMS WERE FIRING AT MID AFTERNOON ALONG A WEAK SURFACE
BOUNDARY STRETCHING FROM SOUTHEAST SOUTH DAKOTA INTO WESTERN
NEBRASKA. THESE STORMS HAVE PLENTY OF INSTABILITY AND SHEAR TO FEED
ON...SOME 2500 J/KG OF MLCAPE AND 40KT OF EFFECTIVE BULK SHEAR...AS
PER LATEST RAP OBJECTIVE ANALYSIS. ALREADY GETTING REPORTS OF SEVERE
HAIL JUST WEST OF OUR AREA WHERE VIGOROUS UPDRAFTS WERE SEEN. AND
FREEZING LEVELS ARE QUITE A BIT LOWER THAN LAST EVENING. SO A
CONTINUED HAIL THREAT IS CERTAINLY EXPECTED...WITH MODEST MICROBURST
POTENTIAL ALSO NOTED ON RAP PROGS.
PERHAPS A BIGGER SHOW WITH POTENTIALLY MORE WIDESPREAD SEVERE LATER
THIS EVENING IS POSSIBLE. MID LEVEL SHORTWAVE DIVING INTO WESTERN
SOUTH DAKOTA WILL CONTINUE SOUTHEAST THIS EVENING...PUSHING A COLD
FRONT ALONG WITH IT. SHEAR PROFILES SHOULD ACTUALLY INCREASE IN
MAGNITUDE GIVEN MID LEVEL SPEED MAX TIED TO WAVE. SHEAR VECTORS ARE
LINING UP NEARLY PARALLEL WITH EXPECTED FRONTAL/CONVECTIVE
LINE...SUPPORTING MORE OF A LINEAR STORM MODE. WIND
FIELDS...PREDICTED DOWNDRAFT CAPE AND LAYER THETA-E DIFFERENCES
APPROACHING 30 ALL SUGGEST SEVERE WIND POTENTIAL AS LINE RACES INTO
EASTERN NEBRASKA. SEVERAL MESOSCALE HI-RES MODELS ARE OFFERING
VARIED OPINIONS AROUND THIS LINE OF THINKING...SO WILL HIT EVENING
THUNDER CHANCES PRETTY HARD. EXPECT STORMS TO SLOWLY DIE OFF LATER
THIS EVENING AND OVERNIGHT AS THEY APPROACH INTERSTATE 80 AND
BEYOND...HOWEVER SEVERE THREAT APPEARS TO LINGER FOR SOME TIME AFTER
DARK.
BY MONDAY MORNING LINGERING STORMS SHOULD BE EXITING OUR
SOUTHEAST CWA. HOWEVER WEAK IMPULSE IN MID LEVEL FLOW COULD TAP
WANING INSTABILITY IN THE MID AFTERNOON TO PRODUCE A STORM OR TWO
IN SOUTHWEST IOWA. THEN NORTHERLY SURFACE FLOW UNDER HIGH PRESSURE
WILL FORETELL A RELATIVELY DRY PERIOD OVER THE NEXT COUPLE OF
DAYS.
HIGHS BOTH TUESDAY AND WEDNESDAY WILL GRADUALLY INCREASE INTO THE
LOWER AND MIDDLE 80S UNDER PLENTY OF SUNSHINE. AND DEW POINTS SHOULD
BE LOWER ON TUESDAY BEFORE BEGINNING TO RETURN WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
OUR RELATIVELY QUIET WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH
THE REST OF THE WEEK. MID LEVEL HIGH PRESSURE RIDGE IS FORECAST BY
BOTH ECMWF AND GFS TO BUILD FROM THE SOUTHERN PLAINS INTO THE
NORTHERN ROCKIES...AND EXPAND A BIT TO THE EAST. THIS WILL TAKE MAIN
STORM TRACK NORTH AND EAST OF OUR AREA...AND ALLOW FOR WARMER
TEMPERATURES BOTH AT THE SURFACE AND ALOFT. WILL MAINTAIN OUR DRY
FORECAST UNTIL MAYBE SATURDAY NIGHT OR SUNDAY WHEN RIDGE IS FORECAST
TO BEGIN TO BREAK DOWN. HIGHS MAINLY IN THE UPPER 80S AND LOWER 90S
SHOULD PREVAIL.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 612 PM CDT SUN AUG 9 2015
BAND OF THUNDERSTORMS WILL AFFECT KOFK FOR THE FIRST FEW HOURS OF
THE TAF PERIOD. THEN ANOTHER LINE OF STORMS MOVING SOUTHEAST WILL
ENTER EASTERN NEBRASKA...AFFECTING KOFK BETWEEN 04Z AND 06Z...THEN
KLNK AND KOMA BETWEEN 06Z AND 09Z. MVFR CIGS/VSBYS WILL BE COMMON
IN STORMS...BUT BRIEFLY LOWER CONDITIONS ARE CERTAINLY POSSIBLE.
STRONG WINDS MAY ACCOMPANY STORMS AS WELL. BEHIND THIS SECOND BAND
OF THUNDERSTORMS...AREAS OF MVFR FOG ARE LIKELY THROUGH 14Z...WITH
A SMALL CHANCE OF MVFR/IFR CIGS AS WELL. THEN NORTH WINDS UNDER
12KT AND VFR CONDITIONS ARE FORECAST BEYOND 14Z AT ALL SITES.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
315 PM CDT SAT AUG 8 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CDT SAT AUG 8 2015
NO BIG CHANGES FROM PREVIOUS THINKING...MAIN CONCERN IS POTENTIAL
FOR SEVERE WEATHER AND HEAVY RAIN. THE SEVERE THREAT WOULD MAINLY
BE PRIOR TO 06Z TONIGHT AND THEN ALSO LATE SUN AFTN/SUN EVENING.
HEAVY RAIN THREAT IS PRIOR TO ABOUT 08Z TONIGHT...AND MAINLY IN
SWRN IA.
JET PATTERN AT 12Z SHOWED 300 MB WINDS OF 50 TO 80 KNOTS FROM SRN
CA INTO SD/ND/MN. A 500 MB LOW WAS OVER SRN ID AT 12Z BUT WATER
VAPOR IMAGERY/RECENT RUC MODEL INITILIZATIONS SHOWED IT HAD MOVED
TO NEAR THE ID/MT/WY BORDER AREA AS OF EARLY THIS AFTN. THIS WILL
CONTINUE TO TRACK SLOWLY NEWD/EWD TONIGHT. THE 19Z KOAX SOUNDING
SHOWED THAT THE MID LEVELS HAD WARMED A BIT SINCE 12Z. OUR 12Z
700 MB TEMP WAS 7.6 C BUT HAD INCREASED TO 10.7 C AS OF 19Z.
19Z SPC MESOANALYSIS SHOWED THAT THERE WAS STILL QUITE A BIT OF
LOWEST 100 MB CONVECTIVE INHIBITION (MLCIN) AND MOST OF THE AREA
WAS NOT OVERLY UNSTABLE. HIGHEST MLCAPE WAS NEAR THE KS BORDER...
AROUND 2000 J/KG. CAP WAS WEAKEST FROM SWRN KS INTO PARTS OF CNTRL
KS AS OF MID AFTN...NEAR AND AHEAD OF SFC LOW PRES CENTER.
THERE REMAINS A CONDITIONAL THREAT OF SEVERE WEATHER FOR MOST OF
THE AREA. 0-6 KM SHEAR IS EXPECTED TO BE ADEQUATE FOR ROTATING
STORMS...BUT THERE IS SOME UNCERTAINTY AS TO WHEN AND WHERE
STRONG/SEVERE STORMS MAY FORM. THE MODELS OFFER VARYING SOLUTIONS.
ONE THING WE SAY IS THAT IT DOES APPEAR THAT BEST FOCUS WILL
SHIFT TO IA AND NRN MO LATER TONIGHT WITH A 30-50 KNOT LOW LEVEL
JET. LOWS SHOULD RANGE FROM MID 60S N TO AROUND 70 S.
WILL KEEP STORM CHANCES OVERNIGHT AND SUNDAY MORNING FOR AT LEAST
PARTS OF THE FCST AREA. BETTER POTENTIAL THOUGH APPEARS TO BE
LATER IN THE DAY ACRS OUR NRN ZONES...AS A FRONTAL SYSTEM DROPS
INTO THE AREA. KEPT SOME LOW POPS FOR LATE SUNDAY NIGHT AND MONDAY
BUT NOT IMPRESSED WITH RAIN POTENTIAL IN THOSE PERIODS FOR NOW...
ESPECIALLY MONDAY WHEN SURFACE RIDGE AXIS WILL BE BUILDING DOWN
ACROSS THE REGION.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT AUG 8 2015
PCPN CHANCES LOOK TO BE 14 PERCENT OR LESS FROM MONDAY NIGHT
ONWARD...SO FCST TEXT WILL NOT HAVE ANY MENTION OF TSTMS IN THOSE
PERIODS. 500 MB RIDGE IS EXPECTED TO BUILD W AND N FROM OK AND TX
MUCH OF THE WEEK...THEN FLATTEN A BIT BY NEXT WEEKEND AS TROUGH
MOVES EAST FROM THE PACIFIC NW AND NRN ROCKIES. LEFT A BLEND OF
GFS AND ECMWF TEMPS IN THE EXTENDED PERIOD...BUT HIGHS MAY END UP
BEING A BIT WARMER THAN THAT.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1217 PM CDT SAT AUG 8 2015
GENERALLY VFR CONDITIONS ARE EXPECTED INTO THE OVERNIGHT PERIOD.
WE WILL SEE A BKN MID AND HIGH LEVEL DECK THROUGH THE DAY TODAY
AND LIGHT SOUTHEAST WINDS. THERE IS SOME THREAT OF SHRA AT
KLNK/KOMA LATE THIS AFTN INTO THE EARLY EVENING AND WILL INCLUDE A
TEMPO GROUP FOR THESE TAFS. OVERNIGHT WE EXPECT SOME IFR CIGS
DEVELOP FOR KOMA/KOFK...WHICH MAY GET CLOSE TO KLNK BY SUN MRNG.
WE WILL ALSO SEE SOME MVFR VSBY OVERNIGHT AS WELL. CONDITIONS
SHOULD IMPROVE BY MID TO LATE MORNING SUNDAY.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...BOUSTEAD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1148 PM CDT FRI AUG 7 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
THE PRIMARY FORECAST CONCERNS ARE IN REGARDS TO THE POTENTIAL FOR
TSTMS/RAIN LATER TONIGHT AND INTO SATURDAY...PLUS THE CHANCE OF
SEVERE WEATHER SATURDAY.
MAIN FEATURES FROM THE UPPER AIR MAPS THIS MORNING INCLUDED THE
FOLLOWING. AT 300 MB A 75 KT JET STREAK WAS OVER SRN CA PUNCHING TO
THE E/NE. THE 500 MB PATTERN IN GENERAL SHOWED TROUGHING ACROSS THE
W AND E COASTS AND A RIDGE CENTERED OVER TX/OK. CLOSED LOWS WERE
NOTED OVER SRN ALTA AND OVER CNTRL CA. 12 HOUR HEIGHT FALLS WERE
AROUND 50 METERS WITH THE CA SYSTEM...WHICH CONTINUED TO LIFT INTO
NV ACCORDING TO RECENT WATER VAPOR IMAGERY AND RECENT RUC MODEL
INITIALIZATIONS. A THERMAL RIDGE AT 700 MB EXTENDED FROM THE TX
PNHDL UP INTO CO. FAIRLY DECENT MOISTURE WAS NOTED AT 700 MB FROM
AZ INTO SRN NV WITH DEWPOINTS 5-8 DEGREES C. THE KOAX SOUNDING
THIS MORNING HAD ABOUT 0.94 INCHES OF PRECIPITABLE WATER (PW). THIS
WILL BE INCREASING OVER THE AREA TONIGHT. 12Z GFS SHOWED VALUES
APPROACHING 2 INCHES FOR MOST OF OUR AREA BY 12Z SAT AND NEAR 2.25
INCHES BY 00Z SUN. THE 12Z NAM WAS A BIT HIGHER AND MIGHT HAVE
BEEN A BIT OVERDONE.
PREVIOUS FORECAST TREND WAS FOR INCREASING POPS OVERNIGHT AND THAT
STILL SEEMS ON TRACK. WILL KEEP HIGHEST POPS PRIOR TO 12Z SAT OVER
ERN NE...SHIFTING HIGHEST NUMBERS TO NERN NE BY LATE MORNING. MID
LEVEL TEMPS ARE EXPECTED TO WARM SAT MORNING OVER THE SRN HALF OF
THE FCST AREA...SO SHIFTED HIGHEST POPS TO OUR WRN IA ZONES FOR THE
LATE AFTN AND EVENING. CONVECTIVE EVOLUTION AFTER THE MORNING STORMS
IS UNCERTAIN...BUT SHEAR PARAMETERS COULD BE FAVORABLE FOR SOME
SUPERCELLS IN THE AFTN AND EVENING. BEST SHOT FOR HEAVY RAIN WILL
BE ACROSS IOWA SATURDAY NIGHT.
STORM CHANCES SHOULD DIMINISH AFTER MIDNIGHT SATURDAY NIGHT...AND
SUNDAY RAIN CHANCES LOOK FAIRLY LOW. MID LEVEL RIDGE AXIS WILL START
TO BUILD FROM TX UP INTO SASK MONDAY WITH DECENT TROUGHING OVER THE
GREAT LAKES REGION.
.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 PM CDT FRI AUG 7 2015
A STRONG MID TROPOSPHERIC RIDGE WILL BE BUILDING AT THE START OF
THIS PERIOD OVER MID AMERICA. BY LATE WEEK...THE CENTER OF THE
ANTICYCLONE THAT STARTED OUT OVER TX/OK SHOULD RETROGRADE BACK
INTO NM AND CO. THIS PATTERN GENERALLY PRODUCES WARMER THAN NORMAL
TEMPERATURES (ESPECIALLY HIGHS) AND BELOW NORMAL PCPN. SO...BUMPED
UP HIGHS A BIT COMPARED TO A GFS/ECMWF BLEND.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1143 PM CDT FRI AUG 7 2015
VFR CONDITIONS STILL PREVAIL AT ALL SITES...BUT SHRA AND POSSIBLY
TSRA WILL AFFECT SITES TONIGHT AND INTO THE EARLY MORNING HOURS.
HAVE INCLUDED PREVAILING SHRA/TEMPO THUNDER AT ALL SITES...WITH
ACTIVITY WANING BY MID-MORNING. WITH CONSIDERABLE UNCERTAINTY
REGARDING CONVECTIVE EVOLUTION LATER TODAY/THIS EVENING...HAVE
OPTED TO KEEP MENTION OUT OF TAFS FOR NOW. POTENTIAL DOES EXIST
FOR SHRA/TSRA AT SITES FROM LATE AFTERNOON THROUGH EVENING...WITH
A SOMEWHAT HIGHER RISK AT KOMA/KLNK THAN KOFK.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...MAYES
AREA FORECAST DISCUSSION
NWS ELKO NV
536 PM PDT SUN AUG 9 2015
.SYNOPSIS...TEMPERATURES WILL REMAIN TYPICAL FOR AUGUST ACROSS
NEVADA THIS WEEK. MONSOON MOISTURE WILL RETURN TO EASTERN NEVADA
BY MIDWEEK...INCREASING THE COVERAGE OF SHOWERS AND THUNDERSTORMS.
&&
.UPDATE...RADAR INDICATES ISOLATED SHOWERS CONTINUING TO
REGENERATE ACROSS NORTHERN NEVADA. INCREASED POP/WX/SKY GRIDS FOR
THE NEXT SEVERAL HOURS. SHOWER ACTIVITY WILL REMAIN ISOLATED
BEFORE DISSIPATING AFTER SUNSET. TURNER
&&
.PREV DISCUSSION... /ISSUED AT 318 PM /
SYNOPSIS...TEMPERATURES RUNNING SLIGHTLY BELOW NORMAL FOR THIS
TIME OF YEAR. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
ACROSS NORTHERN NEVADA THIS AFTERNOON. THERE IS A CHANCE FOR
MONSOON MOISTURE MIDWEEK...FOLLOWED BY ANOTHER PACIFIC STORM NEXT
WEEKEND.
SHORT TERM...TODAY THROUGH TUESDAY. THE HRRR IS PRETTY CONVECTIVE
NORTH OF INTERSTATE 80 THIS AFTERNOON AND INTO THE EVENING...WHICH
GAINS SOME SUPPORT FROM THE LATEST VISIBLE IMAGE ON SATELLITE.
HOWEVER...WITH REGARD TO QPF...THE NAM AND THE HRRR MAY BE OVER
DOING IT A BIT...ALTHOUGH THE PLACEMENT OF THE CONVECTION IS
VERY FEASIBLE. LIGHTNING STRIKES HAVE BEEN OBSERVED OVER PORTIONS
OF ELKO COUNTY NEAR THE IDAHO BORDER. THE HRRR HAS THE CONVECTION
BASICALLY BEING SHUNTED AT 2Z...AND BY 5Z THE LKN CWA IS TSRA
FREE. TOMORROW THE GFS BRINGS A SLUG OF MOISTURE BY 18Z AND THE
NAM HAS NOTHING AT 18Z...AND A FRACTION OF THE QPF SHIELD BY 00Z
WITH AN OFF SET PLACEMENT. THE POPS IN THIS FORECAST PACKAGE
REPRESENTS A CONSALL MODEL BLEND APPROACH...BUT NOT THE BEST
CONFIDENCE. TUESDAY...MORE OF THE SAME CONSALL BLENDING...WITH THE
QPF ON THE EASTERN PORTION OF THE CWA...WHICH ACCOUNTS FOR THE
PROGRESSIVE NATURE OF THE INCOMING PACIFIC LOW.
LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. A NORTHEAST PACIFIC LOW
MOVES ASHORE AND STRUGGLES TO ENTER THE INTERIOR WEST AS IT MOVES
AGAINST THE FOUR CORNERS RIDGE. THIS CREATES MOSTLY DRY FLOW INTO
THE GREAT BASIN...BUT AT TIMES WEAKNESSES IN THE RIDGE-TROUGH
BOUNDARY WILL ALLOW FOR LIMITED MOISTURE INTO THE REGION.
HENCE...PERIODS OF ISOLATED THUNDERSTORMS OF THE HYBRID VARIETY
THROUGH ABOUT FRIDAY. NEXT WEEKEND LOOKS DRY. TEMPS NEAR NORMAL. ONE
THING THOUGH...WINDS INCREASE WEDNESDAY AND THURSDAY WITH LOWER RH
VALUES FOR A POSSIBLE FIRE WEATHER SITUATION. STAY TUNED FOR WHEN
THIS TIME COMES INTO THE SHORT TERM PERIOD.
AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO KELY AND KTPH
THROUGH MONDAY AFTERNOON. ISOLATED THUNDERSTORMS ARE POSSIBLE OVER
NORTHERN NEVADA EARLY SUNDAY EVENING AND MONDAY AFTERNOON. MOST WILL
STAY CLEAR OF KWMC AND KEKO.
FIRE WEATHER...VIRGA...ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ACROSS NORTHERN NEVADA THIS AFTERNOON. SO FAR FWZ 470...HAS
GOTTEN THE LIONS SHARE OF THE LIGHTNING AS CONVECTION HAS BEGUN
TO PERCOLATE OVER NORTHERN NV. THERE IS A CHANCE FOR MONSOON
MOISTURE MIDWEEK...FOLLOWED BY A WIND EVENT THURSDAY AND FRIDAY.
THE MODELS ARE FLIPPING A BIT AND NOT HANDLING THE MONSOON SURGE
FOLLOWED BY A ANOTHER PACNW STORM WELL. THIS ASSESSMENT IS BACKED
BY THE NCEP RMOP WHICH IS IN MARKEDLY LESS CONFIDENT TERRITORY BY
F72...WITH REGARD TO THE ENSEMBLE MEAN FORECAST AT 500 MB.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS ELKO NV
325 PM PDT SAT AUG 8 2015
.SYNOPSIS...REMNANT MOISTURE WILL FUEL ISOLATED TO SCATTERED
THUNDERSTORMS THIS AFTERNOON. DRIER CONDITIONS ANTICIPATED SUNDAY
AND MONDAY. THE MONSOON WILL RETURN OVER EASTERN NEVADA MIDWEEK.
&&
.SHORT TERM...TODAY THROUGH MONDAY. THE LONGWAVE PATTERN FEATURES
AN H5 LOW OVER IDAHO...AND A CLOSED LOW UPSTREAM OFF THE COAST OF
BRITISH COLUMBIA...AND A DOME OF HIGH PRESSURE OVER TEXAS.
SUFFICIENT LI`S AND CAPES FOR CONVECTION INTO THE EVENING...AND
BOTH THE HRRR AND THE 18Z NAM PINGING INTO TSRA FOR THE LKN CWA.
THE CONVECTIVE TEMP FOR 21Z IS 77F FOR KEKO WITH A PW OF .73 OF AN
INCH. THE 18Z RUN OF THE GFS IS MORE STABLE...BUT...POPS WERE
HEDGED TOWARDS A NAM/HRRR COMPROMISE AND REALTIME OBSERVATIONS.
AS TIME ELAPSES...EXPECT THE PWS TO DRY OUT...AND EXPECT AFTERNOON
TEMPERATURES TO REMAIN SLIGHTLY BELOW NORMAL FOR THE MONTH OF
AUGUST.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY. THE LONG TERM MODELS ARE
IN MUCH BETTER AGREEMENT TODAY THAN PREVIOUSLY. EVEN DEPICTING THE
SLUG OF MOISTURE COMING UP OUT OF THE GULF OF CALI WED INTO THU IS
NICELY DONE. THIS IS IN AGREEMENT WITH PREVIOUS IDEAS...TOO.
OVERALL...THERE IS NOT MUCH CHANGE TO THE PREVIOUS FORECAST PACKAGE
OTHER THAN SOME TWEAKS TO MAKE SURE WE AGREE WITH SURROUNDING
OFFICES` FORECASTS. TEMPS WILL BE NEAR NORMAL WITH A LITTLE COOL
DOWN DUE TO CLOUDS. MOSTLY DRY PERIOD WITH INCREASED SOUTHWEST FLOW
FROM PACIFIC LOW COMING IN FIRST PART. ISOLATED MAINLY SOLAR DRIVEN
TERRAIN ENHANCED THUNDERSTORMS COULD OCCUR LATE MONDAY INTO TUESDAY
OVER WHITE PINE COUNTY AND THE JARBIDGE AREA. LOW AND CENTRAL NOAM
RIDGE WORK IN TANDEM WEDNESDAY TO BRING SOME LIMITED RH INTO EASTERN
NEVADA SO HAVE KEPT LOW POP MOSTLY THERE WED AND THUR.
WITH INCREASE OF CONVECTION WEDNESDAY AND THURSDAY AND TIGHTENING OF
GRADIENT ALOFT MIXING WINDS DOWN...COULD SEE SOME FIRE WX CONCERNS
MID TO LATE WEEK.
FRIDAY AND SATURDAY...DRIER AS UPPER LOW OPENS UP AND MOVES
NORTHEAST INTO THE NORTHERN ROCKIES.
&&
.AVIATION...REMNANT MOISTURE AND INSTABILITY HAS ALLOWED FOR
AFTERNOON CUMULUS DEVELOPMENT. CHANCE OF SHOWERS/STORMS, ALTHOUGH
SLIGHT, POSSIBLE THROUGH THE EVENING FOR KEKO, KWMC, AND KELY WITH
THE BEST POTENTIAL IN KEKO. THIS ACTIVITY SHOULD DISSIPATE AFTER
SUNDOWN AND DRY AND VFR CONDITIONS EXPECTED FOR SUN.
&&
.FIRE WEATHER...MORE LIGHTNING POSSIBLE THIS AFTERNOON...WITH THE
BEST LIGHTNING SHOW OVER 467 TODAY SO FAR. EXPECTING A DRYING
TREND...BUT BY MIDWEEK MODELS HINT AT ANOTHER MONSOON SURGE.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98/97
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1038 AM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL DOMINATE OUR WEATHER THROUGH SUNDAY BRINGING
MAINLY DRY CONDITIONS AND COMFORTABLE TEMPERATURES. THE NEXT
SIGNIFICANT CHANCE FOR SHOWERS AND THUNDERSTORMS WILL BE MONDAY
INTO TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VISIBLE SATELLITE IMAGERY SHOWS A MID-HI CLOUD SHIELD MOVING
EASTWARD ASSOCIATED WITH A SHORT WAVE OVER THE GREAT LAKES. THIS
WAVE WAS SEEN WELL IN THE WATER VAPOR IMAGERY. THIS FEATURE HAS
SOME LIGHT PRECIP OR EVEN SOME VIRGA ASSOCIATED WITH IT SINCE IT
WAS MOISTURE STARVED. THIS WAVE WILL SPREAD MID-HI CLDS ACRS THE
REGION THIS AFTERNOON INTO THE EVENING. LOOKING AT KBUF RADAR THE
RADAR ECHOES WERE HAVING A DIFFICULT TIME PENETRATING INTO WRN NY
SUGGESTING ACVTY WAS DRYING UP. SO HAVE OPTED TO KEEP POPS LESS
THAN 15 PCT THRU AFTERNOON IN NY AND NC PA SIMILAR TO PREVIOUS
SHIFT. AT BEST MAYBE SOME AREA GETS A SPRINKLE OR TWO FROM THIS
BUT I FEEL THAT IS A LONG SHOT. SOUTH OF THIS WAVE IN PA THERE WAS
MAINLY CLEAR SKIES AND STRG INSOLATION AND THE LATEST NAM WAS
DEVELOPING ISLD CONVECTION OVER THE HIGHER TERRAIN OF THE
CATSKILLS...POCONOS AND OTHER HIGHLANDS OF NRN PA. THE 12Z NAM
HAS SFC BASED CAPES BETWEEN 500 AND 1000 J/KG IN THESE AREAS.
LOOKING AT THE LL MOISTURE FIELDS IN THE NAM MODEL VS
REALITY...IT APPEARS THE NAM IS A OVERDONE HERE. THIS WUD BE THE
ONLY OTHER CHC FOR ANY PRECIP IN THE REGION. THE LATEST HRRR MODEL
SHOWS NO RADAR ECHOES IN THE BGM FORECAST AREA THRU THIS EVENING.
THE LATEST RAP (WHICH DRYS THE BNDRY LAYER WAY TOO MUCH) BRINGS
SOME SPRINKLES TO THE FINGER LAKES THIS EVENING WITH THE ABV
MENTIONED WAVE. BUT GIVEN THE DRIER BNDRY LAYER IN THIS MODEL NO
CONVECTION POPS IN NE PA OR CATSKILLS. THE RAPS SFC DWPTS DROP
INTO THE 40S WHICH IS UNREALISTIC.
FOR TONIGHT...LEFT PREV SHIFTS SLGHT CHC FOR SHRA IN OUR SRN AND
SW ZONES WHICH IS FROM STUEBEN CO NY TO NE PA FOR NOW AS WE WAIT
FOR THE ALL THE NEW 12Z GUIDC. IF ANYTHING MIGHT HAVE TO PUT SLGHT
CHC FARTHER N TO ACCOUNT FOR THE GREAT LAKES SHORT WAVE WHICH
MOVES ACRS THE REGION. IN ANY EVENT...WE ARE NOT TALKING ABT MUCH
SENSIBLE WX OTHER THAN MAINLY CLDY SKIES TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
4 AM UPDATE...
LIMITED INSTABILITY AND MOISTURE...WITH ONLY WEAK SHORTWAVES
TRAVERSING WNW-ESE FLOW ALOFT...WILL KEEP SHOWER CHANCES /AND
COVERAGE/ SLIGHT AT BEST SUNDAY-SUNDAY NIGHT. HOWEVER...FOR MONDAY
INTO ESPECIALLY MONDAY NIGHT...MODEL CONSENSUS CONTINUES TO SHOW
AMPLIFYING TROUGH DIGGING INTO THE GREAT LAKES REGION MONDAY-
MONDAY NIGHT...WITH INCREASING MOISTURE AND INSTABILITY AHEAD OF
IT. AT THE SAME TIME...A SURFACE LOW IS DEPICTED AS TRACKING INTO
OUR REGION MONDAY NIGHT. THE MODELS DIFFER IN SOME DETAILS...SUCH
AS HIGHER PRECIPITABLE WATER VALUES IN THE NAM...AND A SLOWER
EVOLUTION IN THE ECMWF. BUT FOR THE GENERAL IDEA...MODELS ARE IN
FAIRLY GOOD AGREEMENT.
WE CONTINUE WITH A FORECAST OF INCREASING SHOWER CHANCES
MONDAY...PEAKING LATE MONDAY THROUGH ESPECIALLY MONDAY NIGHT WHEN
SHOWERS WILL BE ESPECIALLY LIKELY. WITH INSTABILITY ALSO
BECOMING PRESENT...THERE WILL BE A CHANCE OF THUNDERSTORMS AS
WELL...HOWEVER MID LEVEL LAPSE RATES AND SHEAR WILL BOTH BE ON THE
LOW SIDE SO SEVERE PROSPECTS ARE MINIMAL. THOUGH PRECIPITABLE
WATER VALUES WILL NOT BE VERY HIGH...THEY ARE FORECAST TO GET
TO AROUND 2 STANDARD DEVIATIONS ABOVE NORMAL...WHICH COMBINED WITH
SLOW SYSTEM PROGRESSION COULD YIELD LOCALIZED HEAVY RAINFALL
/PERHAPS A FEW LOCATIONS GETTING MORE THAN AN INCH/. OVERALL
EXCESSIVE RAINFALL POTENTIAL DOES NOT APPEAR VERY SIGNIFICANT YET
BUT THIS WILL HAVE TO BE MONITORED.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
FOLLOWED CLOSE TO WPC GUIDANCE. OVERALL, UNSETTLED TO START THE
PERIOD WITH AN IMPROVING TREND LATER IN THE WEEK.
UPPER LEVEL TROUGH LINGERS OVER THE AREA MUCH OF THE WEEK. THE
RESULT WILL BE ABUNDANT CLOUDINESS WITH CONTINUING SCATTERED
SHOWERS AND THE CHANCE OF THUNDERSTORMS...ESPECIALLY DURING THE
AFTERNOON HOURS DUE TO DIURNAL HEATING. EXPECT THIS TO OCCUR ON
TUESDAY WITH SHOWERS AND ANY STORMS DYING DOWN AFTER SUNSET AND
THEN POPPING UP AGAIN WEDNESDAY AFTERNOON. BY THURSDAY, AS THE
DEEPER MOISTURE MOVES AWAY EXPECT MORE IN THE WAY OF SOME SUNSHINE
WITH ONLY A SLIGHT CHANCE OF SHOWERS FOLLOWED BY DRY WEATHER FOR
NEXT FRIDAY. THE UPPER LOW AND CLOUDINESS WILL KEEP TEMPS RUNNING
COOLER THAN AVERAGE FOR MOST OF THE LONG RANGE WITH HIGHS MAINLY
IN THE 70S AND LOWS IN THE 50S. BY NEXT FRIDAY, TEMPS RETURN TO
SEASONAL.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
DRY WX CONTS OVER THE AREA BRINGING VFR CONDS. XCPTN CONTS TO BE
LATE AT NGT WHEN LGT WINDS ALLOW VLY FOG TO DVLP. BRIEF
RESTRICTIONS TO IFR PSBL AT ELM LATE NGT...MVFR ELSEWHERE. LGT WLY
FLOW...ESP DURING THE DAY WITH MIXING...WILL CONT. DRAINAGE WINDS
TAKEOVER AT NGT.
.OUTLOOK...
SUN... EXCEPT FOR POSSIBLE EARLY MORNING RESTRICTIONS DUE TO FOG
(MAINLY KELM)...VFR IS EXPECTED.
MON-TUE... RESTRICTIONS POSSIBLE FROM SHOWERS/THUNDERSTORMS.
WED...VFR...BUT POTENTIAL BRIEF RESTRICTIONS IN SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/MDP
NEAR TERM...DJN
SHORT TERM...MDP
LONG TERM...PCF
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
307 PM EDT SAT AUG 8 2015
.SYNOPSIS...
LOW PRESSURE OFF THE NORTH CAROLINA COAST WILL MOVE NORTHEAST
AND ALLOW DRIER AND COOLER AIR TO SETTLE OVER THE AREA THROUGH
EARLY NEXT WEEK. RAIN CHANCES WILL INCREASE TUESDAY INTO WEDNESDAY
AS A COLD FRONT MAKES ITS WAY THROUGH THE REGION. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT LATE WEDNESDAY INTO THE EARLY PART
OF NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...THE SURFACE LOW WAS LOCATED OFFSHORE OF CAPE
HATTERAS AND LIFTING NORTHEAST. STRATOCU WILL PERSIST IN WRAPAROUND
CIRCULATION THROUGH THE REMAINDER OF THE AFTERNOON. A FEW VERY SMALL
AND ISOLATED SHOWERS HAVE POPPED UP ALONG THE NORTHERN TIER OF THE
CWA. THE HRRR DOES DEVELOP SOME OF THIS ACTIVITY FURTHER AS IS
MOVES SOUTHWARD SO AM INCLINED TO KEEP A SMALL POP FOR ISOLATED
SHOWERS THROUGH SUNSET.
OVERNIGHT...LOW CLOUDS SHOULD CONTINUE TO DECREASE HOWEVER MAY SEE
SOME UPPER-LEVEL REMNANTS FROM THE DYING MCC IN THE PLAINS. LIGHT
NNE FLOW OVERNIGHT WILL HINDER FOG DEVELOPMENT BUT WILL LET MIN
TEMPS FALL JUST BELOW CLIMO MOST AREAS.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...AGREEABLE AND EARLY FALL-TYPE FEEL DAYBREAK
SUNDAY WITH MINIMUMS HAVING DIPPED INTO THE UPPER 60S MOST AREAS
BUT WELL REMOVED FROM RECORD LOWS FOR AUGUST 9TH OF 60 AT ILM IN
1997...60 AT FLO IN 2002...AND 62 AT CRE IN 2004. SUNSHINE WILL BE
MORE IN ABUNDANCE SUNDAY AND MONDAY COMPARED TO RECENT DAYS. THE
RELATIVELY LOW DEWPOINT READINGS WILL RESULT IN AN AIR-MASS WHICH
IS PLEASANTLY VOID OF HIGH HUMIDITY CONTENT...ALTHOUGH RETURN FLOW
AND INCREASING ABSOLUTE HUMIDITY WILL LIKELY BE OBSERVED LATE MON.
LATE MONDAY NIGHT INTO VERY EARLY TUESDAY AN APPROACHING SHORTWAVE
AND ASSOCIATED FRONTAL SYSTEM WILL DELIVER A CHANCE OF RAINFALL.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...THE MAIN FOCUS OF THE EXTENDED WILL BE ON
THE COLD FRONT MOVING ACROSS THE REGION LATE TUESDAY INTO EARLY
WEDNESDAY. A POTENT MID LEVEL SHORTWAVE WILL MOVE ACROSS THE GREAT
LAKES/MIDWEST ALONG WITH THIS FRONT. MEDIUM RANGE GUIDANCE SHOWS
FEW CHANGES THIS AFTERNOON AND WE CONTINUE TO ADVERTISE GOOD
CHANCE POPS FOR TUESDAY AND INTO PART OF WEDNESDAY. THE FRONT
MAKES IT ALL THE WAY TO THE FLORIDA PANHANDLE INITIALLY THEN
STALLS. SOME GUIDANCE SHOWS THE FRONT A LITTLE FURTHER TO THE
NORTH BEFORE WASHING OUT. WILL KEEP SLIGHT CHANCE POPS IN FOR
LATER PERIODS TO ADDRESS. TEMPERATURES THROUGHOUT THE PERIOD ARE
WITHIN A COUPLE OF DEGREES OF CLIMATOLOGY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...STUBBORN STRATUS WILL SLOWLY RISE AND SCATTER BY MID
AFTERNOON. ALMOST A DUE NORTH WIND TODAY...GUSTY NEAR THE COAST.
CLEARING SKIES TONIGHT WITH SOME PATCHY FOG POSSIBLE...MAINLY
INLAND. FOG SHOULD STAY IN THE MVFR RANGE. SUNDAY...A NICE
AVIATION DAY WITH NEARLY CLEAR SKIES AND A LIGHT NORTHEAST WIND
AND WEAK HIGH PRESSURE IN PLACE. SOME ISOLATED CONVECTION IS
POSSIBLE OVER THE WESTERN PORTION OF THE REGION...LIKELY AFTER THE
TAF TIME WINDOW.
EXTENDED OUTLOOK...SCATTERED STORMS POSSIBLE ON MONDAY AND
TUESDAY...WITH PERIODS OF MVFR POSSIBLE. OTHERWISE EXPECT VFR
THROUGH THE EXTENDED PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...THE SURFACE LOW WAS LOCATED OFF THE COAST OF
CAPE HATTERAS AND MOVING NORTHEAST THIS AFTERNOON. A NORTHERLY
WIND TRAJECTORY ON THE BACK SIDE OF THE LOW WILL CONTINUE
OVERNIGHT...AND THE PRESSURE GRADIENT WILL TREND WEAKER. THERE IS
AN OUTSIDE CHANCE OF A STRAY SHOWER OVERNIGHT...HOWEVER FOR THE
MOST PART EXPECT NO SIGNIFICANT REDEVELOPMENT OVER THE WATERS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...N-NE WINDS WILL BE GRACING THE 0-20 NM WATERS
DAYBREAK SUNDAY WITH SURFACE LOW PRESSURE ABOUT 100 NM OFFSHORE OF
CAPE HATTERAS. LATE SUNDAY A TRANSITION PERIOD...AS WINDS SWING
FROM THE SE 12 KT OR LESS. SE WINDS MONDAY WILL INCREASE MONDAY
NIGHT TO 13-18 KT AND BECOME S-SSW AHEAD OF AN APPROACHING LOW
PRESSURE SYSTEM FROM THE WEST. NO ADVISORIES APPEAR TO BE NEEDED
FOR THIS TIME PERIOD CURRENTLY. A FEW MARINE TSTMS ARE POSSIBLE
VERY EARLY TUESDAY BY THE PRE-DAWN HOURS. SEAS SUNDAY MAINLY NE
WAVES 3-4 FT EVERY 5-6 SECONDS. SEAS MONDAY ENE 2-3 FT EVERY 6-7
SECONDS AND ESE WAVES 1-2 FT EVERY 10 SECONDS.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...SOUTHWEST WINDS OF 15-20 KNOTS WILL PERSIST
OVER THE WATERS TUESDAY INTO WEDNESDAY MORNING. A COLD FRONT WILL
EASE ACROSS THE WATERS WEDNESDAY WITH WINDS TURNING TO NORTHWEST
WITH A VERY LIGHT SPEED. BY THURSDAY HIGH PRESSURE BUILDS IN
FURTHER ALLOWING A BETTER DEFINED NORTHEAST FLOW TO DEVELOP.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CRM
SHORT TERM...MJC
LONG TERM...SHK
AVIATION...DL/CRM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1240 PM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 1240 PM CDT SAT AUG 8 2015
LATEST RADAR LOOPS INDICATE ONLY SMALL SHOWERS...LIKELY FROM MIDDLE
CLOUDS...ALONG THE ND/SD BORDER IN THE FAR WEST. MAY OR MAY NOT BE
REACHING THE GROUND. LATEST ITERATIONS OF THE HRRR HAVE INDICATED
SHOWERS ADVANCING NORTHEASTWARD A BIT SLOWER THAN EXPECTED. HAVE
LOWERED CHANCES OF SHOWERS EARLY THIS AFTERNOON...THEN INCREASED
TO SCATTERED/LIKELY CHANCES OF THUNDERSHOWERS IN THE SOUTHWEST BY
MID-AFTERNOON. ALSO RAISED THE FORECAST MAX TEMPERATURES IN THE
SOUTH CENTRAL/SOUTHEAST PART OF THE STATE WITH CLOUD COVER IN SD
NOT YET REACHING NORTHWARD INTO THE STATE AND HOURLY TRENDS ON THE
UPSWING A BIT HIGHER THAN IN PREVIOUS FORECAST.
UPDATE ISSUED AT 934 AM CDT SAT AUG 8 2015
FOG HAS DISSIPATED ACROSS THE JAMES VALLEY AREA...WITH SOME LOW
CLOUDS STILL LINGERING IN LAMOURE COUNTY. ADJUSTED HOURLY
TEMPERATURE TRENDS...BUT OTHERWISE THE FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG HAS DISSIPATED NEAR THE JAMESTOWN ASOS...BUT THERE ARE
LIKELY STILL SOME PATCHES IN VALLEYS. THUS...LEFT PATCHY FOG IN
THE FORECAST FOR A COUPLE MORE HOURS. OTHERWISE...THE FORECAST
LOOKS TO BE ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT AUG 8 2015
LOW PRESSURE ACROSS SOUTHERN MANITOBA WILL MOVE SLOWLY EAST
TODAY...REPLACED WITH A SURFACE RIDGE. SOME SCATTERED CU AT
KISN/KMOT ON THE SOUTHWEST EDGE OF THE INFLUENCE OF THE MANITOBA
LOW. FOR SOUTHERN ND TAFS...EXPECTING INCREASING CLOUDS DURING THE
AFTERNOON/EVENING...BEGINNING WITH MID LEVEL CLOUDS AND BECOMING
MVFR LATE TONIGHT. BEST CHANCE OF SHOWERS REACHING THE I94 CORRIDOR
WHERE TAF SITES RESIDE IS LATE. EXPECT SHOWERS AND SCATTERED
THUNDERSTORMS TO OCCUR THIS AFTERNOON/EVENING SOUTH OF THE TAF
SITES...AT KHEI...LINTON FOR EXAMPLE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
934 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 934 AM CDT SAT AUG 8 2015
FOG HAS DISSIPATED ACROSS THE JAMES VALLEY AREA...WITH SOME LOW
CLOUDS STILL LINGERING IN LAMOURE COUNTY. ADJUSTED HOURLY
TEMPERATURE TRENDS...BUT OTHERWISE THE FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG HAS DISSIPATED NEAR THE JAMESTOWN ASOS...BUT THERE ARE
LIKELY STILL SOME PATCHES IN VALLEYS. THUS...LEFT PATCHY FOG IN
THE FORECAST FOR A COUPLE MORE HOURS. OTHERWISE...THE FORECAST
LOOKS TO BE ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG NEAR KJMS WILL DISSIPATE BY 13Z. LOW PRESSURE ACROSS
SOUTHERN MANITOBA WILL MOVE SLOWLY EAST TODAY...REPLACED WITH A
SURFACE RIDGE. SKIES WILL BE MOSTLY CLEAR NORTH WITH INCREASING
CLOUDS SOUTH DURING THE DAY. VFR CONDITIONS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JV
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
644 AM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG HAS DISSIPATED NEAR THE JAMESTOWN ASOS...BUT THERE ARE
LIKELY STILL SOME PATCHES IN VALLEYS. THUS...LEFT PATCHY FOG IN
THE FORECAST FOR A COUPLE MORE HOURS. OTHERWISE...THE FORECAST
LOOKS TO BE ON TRACK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM CDT SAT AUG 8 2015
PATCHY FOG NEAR KJMS WILL DISSIPATE BY 13Z. LOW PRESSURE ACROSS
SOUTHERN MANITOBA WILL MOVE SLOWLY EAST TODAY...REPLACED WITH A
SURFACE RIDGE. SKIES WILL BE MOSTLY CLEAR NORTH WITH INCREASING
CLOUDS SOUTH DURING THE DAY. VFR CONDITIONS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
413 AM CDT SAT AUG 8 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST LATER TODAY AND
INCLUDING THE SOUTH CENTRAL TONIGHT.
CURRENTLY...ZONAL FLOW ALOFT REMAINS OVER THE NORTHERN PLAINS
WITH STACKED LOW PRESSURE MOVING SLOWLY EAST ACROSS SOUTHERN
MANITOBA AND UPPER LEVEL RIDGING OVER THE CENTRAL PLAINS. MOSTLY
CLEAR SKIES OVER MUCH OF WESTERN AND CENTRAL NORTH DAKOTA THIS
MORNING. T/TD SPREADS AT OR NEAR ZERO OVER MANY OBSERVING SITES
OVER NORTHERN NORTH DAKOTA AND ACROSS BOTH THE WESTERN DEVILS LAKE
AND JAMES RIVER BASINS. LAST FEW HRRR RUNS CONTINUE TO INDICATE AT
LEAST PATCHY FOG DEVELOPMENT OVER THESE AREAS YET EARLY THIS
MORNING AND WILL LEAVE IN THE FORECAST.
EMBEDDED SHORT WAVE TROUGH/IMPULSE LIFTING EAST-NORTHEAST ACROSS
THE INTERMOUNTAIN WEST THIS MORNING WILL TRACK EASTWARD INTO THE
NORTHERN HIGH PLAINS TODAY...THEN INTO AND ACROSS THE DAKOTAS
LATER TONIGHT INTO SUNDAY. ASSOCIATED SURFACE LOW WILL MOVE FROM
WYOMING THIS MORNING INTO SOUTH DAKOTA LATER TODAY AND TONIGHT.
PRECIPITATION WILL START TO DEVELOP INTO SOUTHWEST NORTH DAKOTA
THIS AFTERNOON WITH THE APPROACH OF THE MID LEVEL WAVE AND AS THE
SFC LOW MOVES INTO WESTERN SOUTH DAKOTA. PRECIPITATION THEN
SPREADS SLOWLY EAST INTO MY SOUTH CENTRAL COUNTIES TONIGHT. RIDGE
OF SURFACE HIGH PRESSURE BUILDING OVER FAR SOUTH CENTRAL
CANADA/NORTHERN ND WILL KEEP MOST AREAS NORTH OF INTERSTATE 94
DRY. HEAVIEST RAINFALL EXPECTED TO REMAIN OVER SOUTH DAKOTA. CAPE
RATHER WEAK BUT ENOUGH TO LEAVE A SLIGHT CHANCE/ISOLATED MENTION
OF THUNDERSTORMS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 347 AM CDT SAT AUG 8 2015
THE FOCUS THIS MORNING IS ON SUBTROPICAL RIDGE LOCATION.
THE MAIN CHANGE IN MODEL CONSENSUS OVER THE PAST 48 HOURS HAS BEEN
THE WESTWARD SHIFTING OF THE SUBTROPICAL RIDGE AXIS FROM THE CENTRAL
DAKOTAS INTO WESTERN MONTANA BY WEDNESDAY. THE SLOWER PROGRESSION OF
CYCLONIC FLOW WILL ACT TO EXTEND THE DRY PERIOD NEXT WEEK AND
INCREASE HIGH TEMPERATURES ACROSS THE DAKOTAS.
GREATER UNCERTAINTY CREEPS INTO THE FORECAST ON WEDNESDAY NIGHT...AS
MID LEVEL SHORTWAVES MAKE IT INTO THE DAKOTAS IN A FEW GEFS
MEMBERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 410 AM CDT SAT AUG 8 2015
LOW PRESSURE ACROSS SOUTHERN MANITOBA WILL MOVE SLOWLY EAST
TODAY...REPLACED WITH A SURFACE RIDGE. SKIES WILL BE MOSTLY CLEAR
NORTH WITH INCREASING CLOUDS SOUTH DURING THE DAY. VFR CONDITIONS
EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NH
LONG TERM...SCHECK
AVIATION...NH
AREA FORECAST DISCUSSION
NWS NORMAN OK
1035 PM CDT SUN AUG 9 2015
.DISCUSSION...
&&
.AVIATION...
A WEAK FRONT WILL MOVE FROM NORTHERN TO CENTRAL OKLAHOMA MONDAY
MORNING. ISOLATED THUNDERSTORMS ARE POSSIBLE NEAR AND ALONG THE
FRONT ON MONDAY.
&&
.PREV DISCUSSION... /ISSUED 913 PM CDT SUN AUG 9 2015/
UPDATE...
UPDATED HOURLY TEMPERATURE/DEWPOINT/WIND GRIDS.
DISCUSSION...
SFC OBSERVATIONS INDICATE POOLING OF MOISTURE ACROSS PORTIONS OF
NORTHERN OKLAHOMA. MANY LOCATIONS ARE REPORTING DEWPOINTS IN THE LOW
TO MID 70S. THIS POOLING MIGHT BE A RESULT OF A REMNANT OUTFLOW
BOUNDARY. OPTED TO INCREASE DEWPOINTS TO BETTER FIT WITH CURRENT
OBSERVATIONS. MINOR ADJUSTMENTS WERE ALSO MADE TO THE TEMPERATURE
AND WIND GRIDS.
OTHERWISE...THE FORECAST REMAINS ON TRACK. THE LAST FEW HRRR RUNS
AND THE LATEST NAM INDICATE A CONTINUED CHANCE OF SHOWERS AND
STORMS NEAR THE KANSAS/OKLAHOMA BORDER OVERNIGHT.
MAHALE
PREV DISCUSSION... /ISSUED 706 PM CDT SUN AUG 9 2015/
DISCUSSION...
AVIATION...
THUNDERSTORMS WILL OCCASIONALLY AFFECT NORTHWEST OKLAHOMA INTO
TONIGHT. A WEAK FRONT WILL MOVE FROM NORTHERN TO CENTRAL OKLAHOMA
MONDAY MORNING. ISOLATED THUNDERSTORMS ARE POSSIBLE NEAR AND ALONG
THE FRONT ON MONDAY.
PREV DISCUSSION... /ISSUED 254 PM CDT SUN AUG 9 2015/
DISCUSSION...
A FEW SHOWERS CONTINUE TO LINGER ALONG THE STATIONARY FRONT THIS
AFTERNOON ACROSS EXTREME NORTHERN OK. SOUTH OF HERE...AN OUTFLOW
BOUNDARY CAN BE SEEN SLOWLY MOVING TO THE SOUTH FROM NEAR
HENNESSEY TO PERRY. ISOLATED STORMS MAY MANAGE TO DEVELOP ALONG
THIS BOUNDARY THROUGH THE AFTERNOON/EARLY EVENING...PERHAPS AS FAR
WEST AS CLINTON. IF THEY DO...THEY WILL HAVE THE POTENTIAL TO
PRODUCE SEVERE WIND GUSTS. OTHERWISE...STILL EXPECT HIGHEST POPS
LATER TONIGHT ALONG THE BOUNDARY ACROSS NW AND NORTHERN OK AS A
SHORTWAVE TROUGH ROUNDS THE RIDGE. SOME HEAVY RAINFALL AND WIND
GUSTS NEAR 40 TO 50 MPH WILL BE THE MAIN THREATS WITH THESE
STORMS.
AS THE FRONT SLOWLY PROGRESSES SOUTHWARD TOMORROW MORNING THROUGH
TOMORROW AFTERNOON...LOW POPS WILL ACCOMPANY IT OVER CENTRAL OK.
STILL EXPECT HEAT INDICES AHEAD OF THE FRONT TO EXCEED 105 DEGREES
SO ANOTHER HEAT ADVISORY HAS BEEN ISSUED FOR SOUTHERN OK.
DEPENDING ON CLOUD COVER/LINGERING PRECIP TOMORROW HIGH TEMPS MAY
NEED TO BE INCREASED FURTHER NORTH...WHICH COULD RESULT IN AN
EXPANSION OF THE HEAT ADVISORY INTO CENTRAL OK. BELOW AVG TEMPS
ARE STILL EXPECTED BEHIND THE FRONT TUE-FRI. BY TUESDAY...MOST OF
THE RAIN CHCS WILL SHIFT TO THE NW/W WITHIN A MID LEVEL MOIST AXIS
AS SEVERAL MID LEVEL SHORTWAVE TROUGHS CONTINUE TO ROUND THE
EASTERN FRINGE OF THE RIDGE. IT APPEARS RAIN CHANCES WILL SLOWLY
SHIFT EAST INTO CENTRAL OK THROUGH THROUGH MID WEEK BEFORE DRIER
AIR IMPACTS THE REGION FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 75 96 73 90 / 20 30 20 10
HOBART OK 75 99 74 93 / 20 30 20 30
WICHITA FALLS TX 77 103 77 97 / 0 10 20 20
GAGE OK 71 94 70 87 / 50 30 30 30
PONCA CITY OK 76 95 72 88 / 40 20 10 10
DURANT OK 76 104 77 96 / 0 0 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY FROM 1 PM TO 8 PM CDT MONDAY FOR OKZ032-039>043-
045>048-050>052.
TX...NONE.
&&
$$
10/09/09
AREA FORECAST DISCUSSION
NWS NORMAN OK
913 PM CDT SUN AUG 9 2015
.UPDATE...
UPDATED HOURLY TEMPERATURE/DEWPOINT/WIND GRIDS.
&&
.DISCUSSION...
SFC OBSERVATIONS INDICATE POOLING OF MOISTURE ACROSS PORTIONS OF
NORTHERN OKLAHOMA. MANY LOCATIONS ARE REPORTING DEWPOINTS IN THE LOW
TO MID 70S. THIS POOLING MIGHT BE A RESULT OF A REMNANT OUTFLOW
BOUNDARY. OPTED TO INCREASE DEWPOINTS TO BETTER FIT WITH CURRENT
OBSERVATIONS. MINOR ADJUSTMENTS WERE ALSO MADE TO THE TEMPERATURE
AND WIND GRIDS.
OTHERWISE...THE FORECAST REMAINS ON TRACK. THE LAST FEW HRRR RUNS
AND THE LATEST NAM INDICATE A CONTINUED CHANCE OF SHOWERS AND
STORMS NEAR THE KANSAS/OKLAHOMA BORDER OVERNIGHT.
MAHALE
&&
.PREV DISCUSSION... /ISSUED 706 PM CDT SUN AUG 9 2015/
DISCUSSION...
AVIATION...
THUNDERSTORMS WILL OCCASIONALLY AFFECT NORTHWEST OKLAHOMA INTO
TONIGHT. A WEAK FRONT WILL MOVE FROM NORTHERN TO CENTRAL OKLAHOMA
MONDAY MORNING. ISOLATED THUNDERSTORMS ARE POSSIBLE NEAR AND ALONG
THE FRONT ON MONDAY.
PREV DISCUSSION... /ISSUED 254 PM CDT SUN AUG 9 2015/
DISCUSSION...
A FEW SHOWERS CONTINUE TO LINGER ALONG THE STATIONARY FRONT THIS
AFTERNOON ACROSS EXTREME NORTHERN OK. SOUTH OF HERE...AN OUTFLOW
BOUNDARY CAN BE SEEN SLOWLY MOVING TO THE SOUTH FROM NEAR
HENNESSEY TO PERRY. ISOLATED STORMS MAY MANAGE TO DEVELOP ALONG
THIS BOUNDARY THROUGH THE AFTERNOON/EARLY EVENING...PERHAPS AS FAR
WEST AS CLINTON. IF THEY DO...THEY WILL HAVE THE POTENTIAL TO
PRODUCE SEVERE WIND GUSTS. OTHERWISE...STILL EXPECT HIGHEST POPS
LATER TONIGHT ALONG THE BOUNDARY ACROSS NW AND NORTHERN OK AS A
SHORTWAVE TROUGH ROUNDS THE RIDGE. SOME HEAVY RAINFALL AND WIND
GUSTS NEAR 40 TO 50 MPH WILL BE THE MAIN THREATS WITH THESE
STORMS.
AS THE FRONT SLOWLY PROGRESSES SOUTHWARD TOMORROW MORNING THROUGH
TOMORROW AFTERNOON...LOW POPS WILL ACCOMPANY IT OVER CENTRAL OK.
STILL EXPECT HEAT INDICES AHEAD OF THE FRONT TO EXCEED 105 DEGREES
SO ANOTHER HEAT ADVISORY HAS BEEN ISSUED FOR SOUTHERN OK.
DEPENDING ON CLOUD COVER/LINGERING PRECIP TOMORROW HIGH TEMPS MAY
NEED TO BE INCREASED FURTHER NORTH...WHICH COULD RESULT IN AN
EXPANSION OF THE HEAT ADVISORY INTO CENTRAL OK. BELOW AVG TEMPS
ARE STILL EXPECTED BEHIND THE FRONT TUE-FRI. BY TUESDAY...MOST OF
THE RAIN CHCS WILL SHIFT TO THE NW/W WITHIN A MID LEVEL MOIST AXIS
AS SEVERAL MID LEVEL SHORTWAVE TROUGHS CONTINUE TO ROUND THE
EASTERN FRINGE OF THE RIDGE. IT APPEARS RAIN CHANCES WILL SLOWLY
SHIFT EAST INTO CENTRAL OK THROUGH THROUGH MID WEEK BEFORE DRIER
AIR IMPACTS THE REGION FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 75 96 73 90 / 20 30 20 10
HOBART OK 75 99 74 93 / 30 30 20 30
WICHITA FALLS TX 77 103 77 97 / 0 10 20 20
GAGE OK 71 94 70 87 / 50 30 30 30
PONCA CITY OK 76 95 72 88 / 40 20 10 10
DURANT OK 76 104 77 96 / 0 0 10 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY FROM 1 PM TO 8 PM CDT MONDAY FOR OKZ032-039>043-
045>048-050>052.
TX...NONE.
&&
$$
10/11
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
518 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE OHIO VALLEY
LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID AND
UNSETTLED CONDITIONS THAT WILL BRING RAIN THE TO THE REGION MONDAY
AND TUESDAY. HIGH PRESSURE SHOULD DOMINATE THE REST OF THE COMING
WORK WEEK FROM WEDNESDAY TO FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
WEAK UPPER TROFFING AND SOME UPWARD VERTICAL MOTION BEING FORCED
BY THE APPROACHING LEFT EXIT OF AN UPPER JET STREAK HAVE ALLOWED
THE SKY TO FILL WITH PUFFY CU. SO FAR JUST LIGHT RETURNS ON
RADAR...SOME OVER SOMERSET COUNTY AND A FEW OTHERS NORTH OF THE NY
BORDER. RAP MESO ANAL SHOWS A FINGER CAPE EXCEEDING 1000J POKING
UP INTO WESTERN PA...WITH INSTABILITY OVER CENTRAL AREAS MUCH MORE
SUPPRESSED. ENSEMBLES SHOW SMALL CHANCE POPS...FOR THE NEXT 6-8
HOURS...OVER THE LAURELS WITH THE SREF WETTER THAN THE SEEMINGLY
MORE REASONABLE GEFS. HRRR SUPPORTS THE IDEA OF JUST SOME SMALL
CELLULAR CONVECTION DEVELOPING OVER THE NEXT FEW HOURS...THEN
DYING AFTER SUNDOWN...LEAVING THE BULK OF THE OVERNIGHT PRECIP-
FREE.
OVERNIGHT LOWS IN THE MID 50S TO MID 60S WILL BE VERY NEAR NORMAL
FOR EARLY AUGUST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE UPPER
HEIGHTS CONTINUE TO SLOWLY BUILD AND THE MEAN BLYR FLOW WEAKENS
AND BECOMES WEST OR NW.
WEAK SHORTWAVE ENERGY RIDING THE BUILDING RIDGE IS TIMED INTO THE
REGION DURING MAX HEATING...LEADING TO THE DEVELOPMENT OF A BIT
MORE IN THE WAY OF INSTABILITY THAN TODAY. I STILL KEPT POPS ON
THE LOW SIDE...BUT THE AREA COVERAGE FOR THE CHANCE OF A POP-UP
SHOWER OR THUNDERSTORMS WILL BE A BIT LARGER...MAINLY SUNDAY
AFTERNOON.
HIGH TEMPS WILL RANGE FROM NEAR 80 OVER THE FAR NORTH TO MID 80S
OVER THE FAR SOUTH. VERY NEAR OR MAYBE A TAD BELOW NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AN APPROACHING COLD FRONT AND DEEPENING TROUGH OVER EASTERN NORTH
AMERICA WILL BE THE KEY PLAYER IN THE WEATHER DURING THIS PERIOD.
THE FRONT COULD PROVIDE US RAIN MON-TUE AND THE DEEPENING TROUGH
COOL DRY WEATHER WED-FRI.
WARM MOIST AIR WILL MOVE IN AHEAD OF THE APPROACHING COLD FRONT.
THIS WILL INCREASE THE CHANCE OF RAIN OVERNIGHT MONDAY INTO
TUESDAY. BASED ON THE NCEP GEFS AND SREF-PARA THE CHANCE OF RAIN
GOES UP SLOWLY SUNDAY NIGHT INTO MONDAY EVENING. THEN IT COMES UP
FAST MONDAY AFTERNOON AND OVERNIGHT INTO TUESDAY.
AT THIS TIME BEST CHANCE OF RAIN SHOULD BE AROUND 2 PM MONDAY
UNTIL ABOUT 8 AM TUESDAY. THE RAIN PROBABILITIES IN THE GEFS BEGIN
TO DROP OFF FAST AFTER 8 AM TUESDAY. POPS GET LOW AFTER 8 PM
TUESDAY AND THE REST OF THE PERIOD WED-FRIDAY LOOKS TO BE DRY AT
THIS TIME.
THE POTENTIAL FOR A WIDESPREAD 0.5 TO 0.8 INCH RAINFALL EVENT IS
CURRENTLY FORECAST AS THE FRONTAL SYSTEM MOVES ACROSS THE STATE.
BIAS CORRECTING THESE DATA WOULD IMPLY PERHAPS 0.25 TO 0.50 INCHES
OF RAIN IS MORE LIKELY.
THE SURGE OF HIGH PW AIR MONDAY-TUESDAY IS REPLACED BY BELOW
NORMALLY LOW PW AIR WEDNESDAY INTO FRIDAY. IT WILL BE VERY DRY
AFTER THE RAIN. IN ADDITION TO THE DRY AIR...THE GEFS AND NAEFS
FORECAST BELOW NORMAL 850 HPA TEMPERATURES IMPLYING WEDNESDAY-FRIDAY
WILL BE SLIGHTLY COOLER THAN NORMAL. THE TEMPERATURES SHOULD BEGIN
TO REBOUND ON FRIDAY AND INTO NEXT WEEKEND. SHOULD BE A COOL DRY
PERIOD.
THE FLY IN THE OINTMENT IS ALWAYS THE COLD AIR ALOFT WHICH COULD
TRIGGER ISOLATED SHOWERS OUR COARSER LONGER RANGE MODELS WILL NOT
PICK UP ON. WE CANNOT RULE OUT ISOLATED INSTABILITY SHOWERS
WEDNESDAY AFTERNOON AND WE HAVE NO SKILL FORECASTING THESE AT 4
DAYS OUT. BUT THE DEEP TROUGH AND MID-LEVEL COOL AIR IS A PATTERN
WHICH MIGHT FAVOR SUCH A SCENARIO WEDNESDAY AND POSSIBLY THURSDAY
BUT WOULD NOT PUT THAT IN FORECAST AT THIS TIME RANGE.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
A FEW SHOWERS ACROSS THE SW.
ADDED VCSH TO JST.
OTHERWISE MINOR ADJUSTMENTS TO 21Z TAF PACKAGE.
EARLIER DISCUSSION BELOW.
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY.
SCT-BKN CUMULUS CLOUDS HAVE DEVELOPED AND WILL COVER MUCH OF THE
AIRSPACE THROUGH LATE DAY WITH A SMALL CHANCE OF A STRAY
SHOWER...MAINLY OVER THE LAUREL HIGHLANDS INTO THE NORTHERN
MOUNTAINS THROUGH EVENING.
SLOWLY INCREASING LOW LEVEL MOISTURE OVERNIGHT WILL LEAD TO THE
POSSIBILITY OF A FEW HOURS OF MVFR/IFR AROUND SUNRISE. CONDITIONS
WILL IMPROVE RAPIDLY AFTER SUNRISE SUNDAY WITH ANOTHER DAY VERY
MUCH LIKE TODAY...WITH HIGH BASED CLOUDS AND LIGHT WINDS. THERE
COULD BE A STRAY AFTERNOON OR EVENING SHOWER/THUNDERSTORMS IN
SPOTS.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...GRUMM
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
254 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE OHIO VALLEY
LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID AND
UNSETTLED CONDITIONS THAT WILL BRING RAIN THE TO THE REGION MONDAY
AND TUESDAY. HIGH PRESSURE SHOULD DOMINATE THE REST OF THE COMING
WORK WEEK FROM WEDNESDAY TO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK UPPER TROFFING AND SOME UPWARD VERTICAL MOTION BEING FORCED
BY THE APPROACHING LEFT EXIT OF AN UPPER JET STREAK HAVE ALLOWED
THE SKY TO FILL WITH PUFFY CU. SO FAR JUST LIGHT RETURNS ON
RADAR...SOME OVER SOMERSET COUNTY AND A FEW OTHERS NORTH OF THE NY
BORDER. RAP MESO ANAL SHOWS A FINGER CAPE EXCEEDING 1000J POKING
UP INTO WESTERN PA...WITH INSTABILITY OVER CENTRAL AREAS MUCH MORE
SUPPRESSED. ENSEMBLES SHOW SMALL CHANCE POPS...FOR THE NEXT 6-8
HOURS...OVER THE LAURELS WITH THE SREF WETTER THAN THE SEEMINGLY
MORE REASONABLE GEFS. HRRR SUPPORTS THE IDEA OF JUST SOME SMALL
CELLULAR CONVECTION DEVELOPING OVER THE NEXT FEW HOURS...THEN
DYING AFTER SUNDOWN...LEAVING THE BULK OF THE OVERNIGHT PRECIP-
FREE.
OVERNIGHT LOWS IN THE MID 50S TO MID 60S WILL BE VERY NEAR NORMAL
FOR EARLY AUGUST.
&&
.SHORT TERM /SUNDAY/...
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE UPPER
HEIGHTS CONTINUE TO SLOWLY BUILD AND THE MEAN BLYR FLOW WEAKENS
AND BECOMES WEST OR NW.
WEAK SHORTWAVE ENERGY RIDING THE BUILDING RIDGE IS TIMED INTO THE
REGION DURING MAX HEATING...LEADING TO THE DEVELOPMENT OF A BIT
MORE IN THE WAY OF INSTABILITY THAN TODAY. I STILL KEPT POPS ON
THE LOW SIDE...BUT THE AREA COVERAGE FOR THE CHANCE OF A POP-UP
SHOWER OR THUNDERSTORMS WILL BE A BIT LARGER...MAINLY SUNDAY
AFTERNOON.
HIGH TEMPS WILL RANGE FROM NEAR 80 OVER THE FAR NORTH TO MID 80S
OVER THE FAR SOUTH. VERY NEAR OR MAYBE A TAD BELOW NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AN APPROACHING COLD FRONT AND DEEPENING TROUGH OVER EASTERN NORTH
AMERICA WILL BE THE KEY PLAYER IN THE WEATHER DURING THIS PERIOD.
THE FRONT COULD PROVIDE US RAIN MON-TUE AND THE DEEPENING TROUGH
COOL DRY WEATHER WED-FRI.
WARM MOIST AIR WILL MOVE IN AHEAD OF THE APPROACHING COLD FRONT.
THIS WILL INCREASE THE CHANCE OF RAIN OVERNIGHT MONDAY INTO
TUESDAY. BASED ON THE NCEP GEFS AND SREF-PARA THE CHANCE OF RAIN
GOES UP SLOWLY SUNDAY NIGHT INTO MONDAY EVENING. THEN IT COMES UP
FAST MONDAY AFTERNOON AND OVERNIGHT INTO TUESDAY.
AT THIS TIME BEST CHANCE OF RAIN SHOULD BE AROUND 2 PM MONDAY
UNTIL ABOUT 8 AM TUESDAY. THE RAIN PROBABILITIES IN THE GEFS BEGIN
TO DROP OFF FAST AFTER 8 AM TUESDAY. POPS GET LOW AFTER 8 PM
TUESDAY AND THE REST OF THE PERIOD WED-FRIDAY LOOKS TO BE DRY AT
THIS TIME.
THE POTENTIAL FOR A WIDESPREAD 0.5 TO 0.8 INCH RAINFALL EVENT IS
CURRENTLY FORECAST AS THE FRONTAL SYSTEM MOVES ACROSS THE STATE.
BIAS CORRECTING THESE DATA WOULD IMPLY PERHAPS 0.25 TO 0.50 INCHES
OF RAIN IS MORE LIKELY.
THE SURGE OF HIGH PW AIR MONDAY-TUESDAY IS REPLACED BY BELOW
NORMALLY LOW PW AIR WEDNESDAY INTO FRIDAY. IT WILL BE VERY DRY
AFTER THE RAIN. IN ADDITION TO THE DRY AIR...THE GEFS AND NAEFS
FORECAST BELOW NORMAL 850 HPA TEMPERATURES IMPLYING WEDNESDAY-FRIDAY
WILL BE SLIGHTLY COOLER THAN NORMAL. THE TEMPERATURES SHOULD BEGIN
TO REBOUND ON FRIDAY AND INTO NEXT WEEKEND. SHOULD BE A COOL DRY
PERIOD.
THE FLY IN THE OINTMENT IS ALWAYS THE COLD AIR ALOFT WHICH COULD
TRIGGER ISOLATED SHOWERS OUR COARSER LONGER RANGE MODELS WILL NOT
PICK UP ON. WE CANNOT RULE OUT ISOLATED INSTABILITY SHOWERS
WEDNESDAY AFTERNOON AND WE HAVE NO SKILL FORECASTING THESE AT 4
DAYS OUT. BUT THE DEEP TROUGH AND MID-LEVEL COOL AIR IS A PATTERN
WHICH MIGHT FAVOR SUCH A SCENARIO WEDNESDAY AND POSSIBLY THURSDAY
BUT WOULD NOT PUT THAT IN FORECAST AT THIS TIME RANGE.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY.
SCT-BKN CUMULUS CLOUDS HAVE DEVELOPED AND WILL COVER MUCH OF THE
AIRSPACE THROUGH LATE DAY WITH A SMALL CHANCE OF A STRAY
SHOWER...MAINLY OVER THE LAUREL HIGHLANDS INTO THE NORTHERN
MOUNTAINS THROUGH EVENING.
SLOWLY INCREASING LOW LEVEL MOISTURE OVERNIGHT WILL LEAD TO THE
POSSIBILITY OF A FEW HOURS OF MVFR/IFR AROUND SUNRISE. CONDITIONS
WILL IMPROVE RAPIDLY AFTER SUNRISE SUNDAY WITH ANOTHER DAY VERY
MUCH LIKE TODAY...WITH HIGH BASED CLOUDS AND LIGHT WINDS. THERE
COULD BE A STRAY AFTERNOON OR EVENING SHOWER/THUNDERSTORMS IN
SPOTS.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...GRUMM/LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...GRUMM
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
218 PM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE OHIO VALLEY
LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID AND
UNSETTLED CONDITIONS THAT WILL LAST INTO THE START OF THE NEW WORK
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK UPPER TROFFING AND SOME UPWARD VERTICAL MOTION BEING FORCED
BY THE APPROACHING LEFT EXIT OF AN UPPER JET STREAK HAVE ALLOWED
THE SKY TO FILL WITH PUFFY CU. SO FAR JUST LIGHT RETURNS ON
RADAR...SOME OVER SOMERSET COUNTY AND A FEW OTHERS NORTH OF THE NY
BORDER. RAP MESO ANAL SHOWS A FINGER CAPE EXCEEDING 1000J POKING
UP INTO WESTERN PA...WITH INSTABILITY OVER CENTRAL AREAS MUCH MORE
SUPPRESSED. ENSEMBLES SHOW SMALL CHANCE POPS...FOR THE NEXT 6-8
HOURS...OVER THE LAURELS WITH THE SREF WETTER THAN THE SEEMINGLY
MORE REASONABLE GEFS. HRRR SUPPORTS THE IDEA OF JUST SOME SMALL
CELLULAR CONVECTION DEVELOPING OVER THE NEXT FEW HOURS...THEN
DYING AFTER SUNDOWN...LEAVING THE BULK OF THE OVERNIGHT PRECIP-
FREE.
OVERNIGHT LOWS IN THE MID 50S TO MID 60S WILL BE VERY NEAR NORMAL
FOR EARLY AUGUST.
&&
.SHORT TERM /SUNDAY/...
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE UPPER
HEIGHTS CONTINUE TO SLOWLY BUILD AND THE MEAN BLYR FLOW WEAKENS
AND BECOMES WEST OR NW.
WEAK SHORTWAVE ENERGY RIDING THE BUILDING RIDGE IS TIMED INTO THE
REGION DURING MAX HEATING...LEADING TO THE DEVELOPMENT OF A BIT
MORE IN THE WAY OF INSTABILITY THAN TODAY. I STILL KEPT POPS ON
THE LOW SIDE...BUT THE AREA COVERAGE FOR THE CHANCE OF A POP-UP
SHOWER OR THUNDERSTORMS WILL BE A BIT LARGER...MAINLY SUNDAY
AFTERNOON.
HIGH TEMPS WILL RANGE FROM NEAR 80 OVER THE FAR NORTH TO MID 80S
OVER THE FAR SOUTH. VERY NEAR OR MAYBE A TAD BELOW NORMAL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A WEAK TROUGH OF LOW PRESSURE AT THE SURFACE AND ALOFT SLIDE
SLOWLY SE ACROSS THE STATE EARLY NEXT WEEK.
USING THE GEFS ENSEMBLES THE STRONGEST FLOW AND MOISTURE REMAINS
TO THE NORTH AND EAST OF CENTRAL PA. THERE/S ONLY A SLIGHT CHANCE
OF SHOWERS SUNDAY AFTERNOON. THIS IS SPECIFICALLY THE RESULT OF A
WEAK SHORTWAVE RIDING N PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS
PLUMES INDICATE A GRADUAL WARMING TREND INTO THE WEEKEND...WITH
READINGS CLOSE TO AVERAGE FOR EARLY AUGUST.
THE MODELS FOR THE LONG RANGE PATTERN COME TO A FAIR AGREEMENT
THOUGH SLIGHT TIMING DIFFERENCES ARE PRESENT. THE NEXT WEATHER
SYSTEM...AND THE BEST CHANCE FOR PRECIPITATION WILL BE A COLD
FRONT THAT PASSES THROUGH TUESDAY. WITH SLOW MOVEMENT OF FRONT...
HAVE GIVEN A BROAD BRUSH OF POPS MONDAY NIGHT THROUGH TUESDAY
NIGHT. HAVE KEPT MAIN FRONTAL PASSAGE LATE TUESDAY
INTO TUE NIGHT...THOUGH CAN/T RULE OUT THE FRONT STALLING AND
PASSING WEDNESDAY. HIGHER PWATS WORK INTO THE REGION ON SW FLOW
AS HGTS FALL AHEAD OF APPROACHING TROF MONDAY...SO CHC OF
SHRA/TSRA CONTINUES. DEEPENING TROUGH POSSIBLY STALLED COLD FRONT
WILL LKLY RESULT IN SCATTERED SHRA/TSRA TUESDAY NIGHT INTO
WEDNESDAY. THE GEFS AND EC BOTH CURRENTLY INDICATE THE POSSIBILITY
OF HVY RAINFALL ACROSS EASTERN PA ASSOC WITH THIS SLOWING FRONT.
COOLER/DRIER WX IS LIKELY BY MIDWEEK AS THE LONG TERM PATTERN WILL
BE DOMINATED BY A ROTATING QUASI-STATIONARY UPPER LEVEL LOW
CENTERED OVER EASTERN CANADA. EXPECT THIS SYSTEM TO BRING COOL MID
LVL TEMPS OVR THE REGION AND COULD PROMOTE PM SHOWERS...ESP OVR
THE MTNS THROUGH THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS EXPECTED THROUGH SUNDAY.
SCT-BKN CUMULUS CLOUDS HAVE DEVELOPED AND WILL COVER MUCH OF THE
AIRSPACE THROUGH LATE DAY WITH A SMALL CHANCE OF A STRAY
SHOWER...MAINLY OVER THE LAUREL HIGHLANDS INTO THE NORTHERN
MOUNTAINS THROUGH EVENING.
SLOWLY INCREASING LOW LEVEL MOISTURE OVERNIGHT WILL LEAD TO THE
POSSIBILITY OF A FEW HOURS OF MVFR/IFR AROUND SUNRISE. CONDITIONS
WILL IMPROVE RAPIDLY AFTER SUNRISE SUNDAY WITH ANOTHER DAY VERY
MUCH LIKE TODAY...WITH HIGH BASED CLOUDS AND LIGHT WINDS. THERE
COULD BE A STRAY AFTERNOON OR EVENING SHOWER/THUNDERSTORMS IN
SPOTS.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1029 AM EDT SAT AUG 8 2015
.SYNOPSIS...
HIGH PRESSURE OVER CENTRAL QUEBEC CANADA WILL RIDGE SOUTH INTO
THE AREA TODAY. WEAK LOW PRESSURE WILL MOVE OUT OF THE CENTRAL
UNITED STATES LATER SUNDAY AND SUNDAY NIGHT...BRINGING MORE HUMID
AND UNSETTLED CONDITIONS THAT WILL LAST INTO THE START OF THE NEW
WORK WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE TO THE NORTH WILL KEEP MOST AREAS DRY AND PARTLY TO
MOSTLY SUNNY TODAY. THE REGION IS UNDER A GENERAL WEAKNESS IN THE
UPPER AIR PATTERN. THE APPROACH OF A JET STREAK OUT OF THE LOWER GR
LAKES LATER TODAY COULD PROVIDE JUST ENOUGH LIFT TO TRIGGER AN
ISOLATED SHOWER OR TWO. MID LEVEL LAPSE RATES ARE EXPECTED TO BE
WEAK AND WHILE THE MODELS DEVELOP SOME CAPE...IT WILL BE VERY
MEAGER. HRRR SHOWS SOME WIDELY SCATTERED SMALL CELLULAR CONVECTION
WHICH GENERALLY EQUATES TO NOT MUCH OF ANYTHING HAPPENING...SO I
BACKED OFF THE POPS PRETTY HARD...CONFINING THE VERY LOW CHANCES
FOR A POP UP SHOWER MAINLY TO OUR WESTERN HIGHER TERRAIN.
HIGH TEMPS TODAY WILL RANGE FROM THE MID 70S ACROSS THE LAUREL
HIGHLANDS AND PORTIONS OF THE NRN MTNS...TO THE U70S TO L80S
ACROSS THE SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
PERSISTENT...JET EXIT REGION AND ASSOCIATED WEAK-MDT LIFT WILL BE
OVR THE REGION TONIGHT AND SUNDAY. THIS HIGHER LEVEL UVVEL AND
CONTINUED LIGHT EASTERLY FLOW IN THE UPPER BLYR WILL HELP TO
MAINTAIN PLENTY OF CLOUDS AND SOME SPOTTY SHOWERS.
LOWS EARLY SUNDAY WILL BE IN THE MID TO UPPER 50S OVER THE
NORTHERN MOUNTAINS...AND LOWER TO MID 60S IN THE SOUTHERN VALLEYS.
CONDITIONS SHOULD WARM AND PARTIALLY CLEAR SUNDAY AS THE MEAN BLYR
FLOW WEAKENS AND BECOMES WEST OR NW. A LIGHT SHOWER CAN`T BE RULED
OUT SUNDAY...BUT MOST OF THEM SHOULD OCCUR FROM THE CENTRAL MTS TO
THE LAUREL HIGHLANDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WEAK TROUGH OF LOW PRESSURE AT THE SURFACE AND ALOFT SLIDE
SLOWLY SE ACROSS THE STATE EARLY NEXT WEEK.
USING THE GEFS ENSEMBLES THE STRONGEST FLOW AND MOISTURE REMAINS
TO THE NORTH AND EAST OF CENTRAL PA. THERE/S ONLY A SLIGHT CHANCE
OF SHOWERS SUNDAY AFTERNOON. THIS IS SPECIFICALLY THE RESULT OF A
WEAK SHORTWAVE RIDING N PERIPHERY OF MISS VALLEY UPPER RIDGE. GEFS
PLUMES INDICATE A GRADUAL WARMING TREND INTO THE WEEKEND...WITH
READINGS CLOSE TO AVERAGE FOR EARLY AUGUST.
THE MODELS FOR THE LONG RANGE PATTERN COME TO A FAIR AGREEMENT
THOUGH SLIGHT TIMING DIFFERENCES ARE PRESENT. THE NEXT WEATHER
SYSTEM...AND THE BEST CHANCE FOR PRECIPITATION WILL BE A COLD
FRONT THAT PASSES THROUGH TUESDAY. WITH SLOW MOVEMENT OF FRONT...
HAVE GIVEN A BROAD BRUSH OF POPS MONDAY NIGHT THROUGH TUESDAY
NIGHT. HAVE KEPT MAIN FRONTAL PASSAGE LATE TUESDAY
INTO TUE NIGHT...THOUGH CAN/T RULE OUT THE FRONT STALLING AND
PASSING WEDNESDAY. HIGHER PWATS WORK INTO THE REGION ON SW FLOW
AS HGTS FALL AHEAD OF APPROACHING TROF MONDAY...SO CHC OF
SHRA/TSRA CONTINUES. DEEPENING TROUGH POSSIBLY STALLED COLD FRONT
WILL LKLY RESULT IN SCATTERED SHRA/TSRA TUESDAY NIGHT INTO
WEDNESDAY. THE GEFS AND EC BOTH CURRENTLY INDICATE THE POSSIBILITY
OF HVY RAINFALL ACROSS EASTERN PA ASSOC WITH THIS SLOWING FRONT.
COOLER/DRIER WX IS LIKELY BY MIDWEEK AS THE LONG TERM PATTERN WILL
BE DOMINATED BY A ROTATING QUASI-STATIONARY UPPER LEVEL LOW
CENTERED OVER EASTERN CANADA. EXPECT THIS SYSTEM TO BRING COOL MID
LVL TEMPS OVR THE REGION AND COULD PROMOTE PM SHOWERS...ESP OVR
THE MTNS THROUGH THE LATTER HALF OF NEXT WEEK.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS EXPECTED THROUGH MOST OF THE WEEKEND.
SCT-BKN MID CLOUDS SHOULD COVER MUCH OF THE AIRSPACE TODAY WITH
LOW CONFIDENCE IN A STRAY SHOWER...MAINLY OVER THE LAUREL
HIGHLANDS INTO THE NORTHERN MOUNTAINS THIS AFTERNOON AND EVENING.
SHORT DURATION SUB-VFR RESTRICTIONS ARE POSSIBLE DURING THE
PREDAWN AND EARLY MORNING HOURS SUNDAY DUE TO PATCHY FOG/LOW
CLOUDS.
MORE ACTIVE WX FCST INTO EARLY NEXT WEEK WITH SHOWERS/TSTMS LKLY
MON INTO TUE.
OUTLOOK...
MON-TUE...VFR-MVFR. SHOWERS LKLY/ISOLD TSTMS.
WED...MVFR-VFR CIGS/SCT SHOWERS WEST. MAINLY VFR CENTRAL/EAST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...FITZGERALD/LAMBERT
LONG TERM...LAMBERT/RXR
AVIATION...STEINBUGL
AREA FORECAST DISCUSSION
NWS AMARILLO TX
1057 PM CDT SUN AUG 9 2015
.AVIATION...
06Z TAFS...STILL SOME QUESTION ON TIMING OF CONVECTION THROUGH THE
OVERNIGHT HOURS. SCATTERED THUNDERSTORMS HAVE AND WILL CONTINUE TO
DEVELOP ACROSS THE NORTHERN AND CENTRAL TEXAS PANHANDLE...AND SLOWLY
SUBSIDE BY MORNING. COVERAGE IS EXPECTED TO INCREASE AGAIN TOMORROW
AFTERNOON AND EVENING ACROSS THE PANHANDLES...STARTING WITH PROB30
IN THE AFTERNOON AND PREVAILING ACROSS NORTHERN SITES LATE MONDAY
NIGHT. CONFIDENCE IS LOW IN WIND DIRECTION AT KAMA AS A WEAK BOUNDARY
REMAINS NEAR THE AREA AND IS UNCLEAR HOW QUICKLY WINDS WILL SHIFT
NORTHEASTERLY BEHIND IT.
ELSENHEIMER
&&
.PREV DISCUSSION... /ISSUED 431 PM CDT SUN AUG 9 2015/
DISCUSSION...
A WEAK BOUNDARY SLOWLY SAGGING SOUTH SHOULD BE THE FOCUS FOR STORM
DEVELOPMENT THIS AFTERNOON AND INTO THE OVERNIGHT HOURS. STORMS COULD
ALSO DEVELOP ALONG AN AREA OF CONVERGENCE FROM CANADIAN TO BUSHLAND.
THIS DEVELOPMENT IS SHOWN IN THE HRRR OUTPUT, BUT MORNING CLOUD
COVER HAS SLOWED THE WARMING IN THESE AREAS WHICH MAY DELAY THE
INITIATION TO LATER IN THIS EVENING. ANY STORMS THAT DO DEVELOP ALONG
THIS CONVERGENCE AREA SHOULD MOVE OFF INTO WESTERN OKLAHOMA LATER
THIS EVENING AS A WEAK SHORTWAVE SEEN IN WATER VAPOR IMAGERY OVER
SOUTHERN NEW MEXICO ROUND THE RIDGE. THIS SHORTWAVE SHOULD ALSO HELP
CONVECTION TO DEVELOP ALONG THE SOUTHWARD MOVING BOUNDARY. BOTH
ROUNDS OF STORMS SHOULD HAVE THE POTENTIAL TO BECOME STRONG TO
MARGINALLY SEVERE WITH AROUND 2000 J/KG AND DEEP LAYER SHEAR AROUND
20-25KT. HEAVY RAIN WILL ALSO BE OF CONCERN WITH ANY STORM THAT
DEVELOPS. PWAT VALUES OVERNIGHT CONTINUE TO HOVER RIGHT AROUND THE
+2SD FOR THIS TIME OF YEAR. WHILE AVERAGE FORECAST AMOUNTS RANGE FROM
A QUARTER OF AN INCH UP TO THREE QUARTERS OF AN INCH, THERE REMAINS
AS RISK FOR LOCALIZED AMOUNTS UP TO 1.5 INCHES WITH THE STORMS
THROUGH MONDAY MORNING.
A FEW LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE FOR THE
MONDAY MORNING COMMUTE BUT RAINFALL AMOUNTS FROM THESE STORMS SHOULD
BE LESS THAN THE OVERNIGHT STORMS. AFTER A BRIEF LULL AROUND MIDDAY
THE NEXT ROUND OF STORMS IS EXPECTED TO DEVELOP AS THE UPPER LEVEL
FLOW BECOMES MORE NORTHWESTERLY. THE WIND SHIFT, WHILE MOSTLY SOUTH
OF THE PANHANDLES, SHOULD STILL BE POSITIONED TO ALLOW SIZABLE
ISENTROPIC UPGLIDE MONDAY AFTERNOON INTO TUESDAY. THE THOUGHT OF A
FLASH FLOOD WATCH FOR MONDAY AFTERNOON INTO TUESDAY MORNING
CONTINUES TO COME UP BUT THERE HAS BEEN SIGNIFICANT DISCREPANCIES
BETWEEN MODEL RUNS. YESTERDAY THE GFS SHOWED UP TO 3 INCHES FOR THE
NORTHWEST AND SHOWS AROUND AN INCH STORM TOTAL (JUST LIKE THE ECMWF
SHOWED YESTERDAY). TODAY IT`S THE MORNING NAM WHICH SHOWS 2-4 INCHES
ACROSS THE WESTERN OKLAHOMA PANHANDLE WITH EVEN HIGHER AMOUNTS IN
SOUTHEASTERN COLORADO (ALTHOUGH THE 18Z RUN HAS ALREADY BEGUN TO
BACK OFF ON THESE AMOUNTS). AS A RESULT OF THESE DISCREPANCIES WILL
HOLD OFF ON ISSUING A WATCH UNTIL THE IMPACTED AREA CAN BE NARROWED
DOWN. RAINFALL AMOUNTS WITH THIS ROUND ARE EXPECTED TO BE HIGHEST
ACROSS THE NORTHERN TEXAS AND OKLAHOMA PANHANDLES AND RANGE BETWEEN
THREE QUARTERS OF AN INCH UP TO 1.5 INCHES WITH LOCALLY HIGHER
AMOUNTS POSSIBLE. AMOUNTS ACROSS THE SOUTHERN TEXAS PANHANDLE LOOK TO
RANGE BETWEEN A QUARTER OF AN INCH UP TO THREE QUARTERS OF AN INCH
WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
WEDNESDAY THROUGH THE REST OF THE WEEK...THE RIDGE CONTINUES TO MOVE
INTO THE CONTINENTAL DIVIDE TO KEEP THE PANHANDLES WITH A NORTH-
NORTHWEST FLOW REGIME ALOFT. THIS WILL KEEP OFF AN ON RAIN CHANCES IN
THE FORECAST AND SLIGHTLY COOLER TEMPERATURES THROUGH THE END OF THE
WEEK.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
18/6
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
852 PM CDT SUN AUG 9 2015
.UPDATE... /NPW CANCELED/
ALL HEAT INDEX REPORTS IN THE AREA FELL BELOW 105 AND WELL BELOW
THE ADVISORY CRITERIA OF 108/110 DEGREES FOR EAST/WEST COUNTIES.
A SPECIAL WEATHER STATEMENT FOR THE NEXT COUPLE DAYS REPLACES THE
CANCELED HEAT ADVISORY.
&&
.PREV DISCUSSION... /ISSUED 637 PM CDT SUN AUG 9 2015/
AVIATION.../00Z TAF CYCLE/
VFR SKC ACROSS MUCH OF THE REGION WITH ONLY A FEW/SCT250 CIRRUS
CLOUDS AS OF 09/2330Z. VFR WILL CONTINUE UNTIL 09Z OR SO WITH
DEVELOPMENT OF MVFR STRATUS CLOUDS INVOF KSAT/KSSF AND KAUS THROUGH
14-15Z. HIGHEST CONFIDENCE EXISTS FOR SAT/SSF PER SOUNDING ANALYSIS
AND HRRR OUTPUT. KAUS COULD ALSO BE IMPACTED WITH BKN015 CIGS BUT
MAY BE MORE SPORADIC. KDRT SHOULD STAY VFR THROUGH THE NIGHT BUT
STRATUS WAS CLOSE BY THIS MORNING AND THIS TREND WILL NEED TO
MONITORED IN THE 06Z TAF ISSUANCE. CURRENT SURFACE WINDS OF 10-15 KT
OUT OF THE SE WILL CALM TO 5-10KT OVERNIGHT. VFR CONDITIONS WILL
PREVAIL MONDAY AFTER 15Z WITH A REPEAT OF TODAY.
PREV DISCUSSION... /ISSUED 240 PM CDT SUN AUG 9 2015/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE THIS AFTERNOON. CURRENT
HEAT ADVISORY WILL EXPIRE THIS EVENING. PEAK HEATING HAS YET TO
OCCUR BUT LOOKS LIKE A FEW SPOTS WILL HIT ADVISORY CRITERIA MAINLY
OVER THE FAR EAST...DECENT MIXING ACROSS THE REST OF THE AREA WILL
DROP DEW POINTS THROUGH THE DAY. MILD NIGHT TONIGHT WITH A REPEAT
OF STRATUS FORMATION ACROSS CENTRAL SECTIONS WITH STRONGER LOW LEVEL
SOUTHERLY FLOW. ANOTHER HOT DAY ON MONDAY BUT THE UPPER RIDGE WILL
START A WESTWARD MOVEMENT THAT WILL BRING SLIGHT ADJUSTMENTS TO POP
AND TEMPS LATER IN THE WEEK. FAIRLY LOW DEWPOINTS WILL GENERALLY
KEEP AREA HEAT INDEX VALUES JUST BELOW HEAT ADVISORY CRITERIA
LEVELS. A WEAK FRONT WILL PUSH SOUTH INTO THE RED RIVER
AREA...HELPING TO DECREASE THE GRADIENT MONDAY NIGHT AND LIMIT THE
EARLY MORNING CLOUD COVER BY TUESDAY.
LONG TERM (TUESDAY THROUGH SUNDAY)...
AS THE UPPER RIDGE SHIFTS WEST BY MID WEEK...A SIMILAR
PATTERN WILL DEVELOP LIKE THE END OF JULY. A WEAK BACKDOOR COOL
FRONT WILL PUSH INTO EAST AND NE TEXAS AS MID AND UPPER FLOW BECOMES
INCREASINGLY EASTERLY/NORTHEASTERLY. RH TIME SECTIONS SHOWS AN
INCREASE IN MID LEVEL MOISTURE STARTING LATE TUE INTO WED. THIS
MOISTURE INCREASE...ALONG WITH THE EXPECTED HOT TEMPS...SHOULD BE
ENOUGH TO FIRE UP ISOLATED/SCT CONVECTION DURING THE
AFTERNOON/EVENING HOURS ON WED AND AGAIN ON THU. LIKE THE PREVIOUS
SYSTEM ABOUT 10 DAYS AGO...STORMS COULD PRODUCE SOME STRONG
DOWNDRAFTS...WITH SEVERAL OUTFLOW BOUNDARIES LIKELY HELPING TO
INITIATE ADDITIONAL STORMS. THIS MID LEVEL MOISTURE WILL PUSH WEST
THROUGH THE WEEK...AND BY WEEKS END...POP WILL BE CONFINED TO THE
FAR WEST AND NORTHWEST.
BY THE WEEKEND AND EARLY NEXT WEEK...LONG RANGE MODELS ARE SHOWING
AN UPPER LOW OVER THE SE U.S. MOVING WEST ALONG THE NORTHERN GULF
COAST...MOVING TOWARD THE TEXAS COAST. LOWERING 500MB HEIGHTS AND
BETTER MOISTURE LEVELS WILL KEEP THE INTENSE HEAT AWAY...BUT THE
HIGHER DEWPOINTS MIGHT ACTUALLY KEEP HEAT INDEX VALUES PLENTY WARM.
CANT RULE OUT SOME CHANCES OF RAIN ESPECIALLY IN THE COASTAL PLAINS
DUE TO THE PROXIMITY OF THE UPPER LOW. THE HOPE WILL BE FOR THIS
SYSTEM AND MOISTURE TO PUSH FARTHER INLAND AND GIVE SOME RAIN
CHANCES BEYOND THE 7 DAY PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 102 78 101 77 / 0 0 0 - 10
AUSTIN BERGSTROM INTL AIRPORT 74 101 74 101 76 / 0 0 0 - 10
NEW BRAUNFELS MUNI AIRPORT 77 102 76 101 76 / 0 0 0 0 -
BURNET MUNI AIRPORT 73 101 76 101 78 / 0 0 0 - 10
DEL RIO INTL AIRPORT 77 102 77 103 78 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 75 102 77 102 79 / 0 0 0 - 10
HONDO MUNI AIRPORT 74 101 74 102 75 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 76 100 75 101 77 / 0 0 0 - -
LA GRANGE - FAYETTE REGIONAL 75 101 77 103 77 / 0 0 0 10 10
SAN ANTONIO INTL AIRPORT 78 101 77 101 78 / 0 0 0 0 -
STINSON MUNI AIRPORT 77 102 76 101 77 / 0 0 0 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...ALLEN
SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS AMARILLO TX
645 PM CDT SUN AUG 9 2015
.AVIATION...
CONVECTION AND A WIND SHIFT WILL BE THE MAIN FOCUS OF THE 00Z TAF
ISSUANCE. ISOLATED CONVECTION HAS DEVELOPED ACROSS THE PANHANDLES
THIS AFTERNOON. KAMA ALREADY HAD A STORM DEVELOP JUST OUTSIDE OF THE
10 MILE RADIUS AND HAS SINCE BEGUN TO DISSIPATE. BOTH KDHT AND KGUY
WILL HAVE A CHANCE FOR CONVECTION AS THE EVENING HOURS PROGRESS. ANY
STORM WHICH AFFECTS A TERMINAL COULD BE CAPABLE OF PRODUCING GUSTY
WINDS UP TO 40KTS AND HEAVY RAIN WHICH COULD REDUCE FLIGHT
CATEGORIES. TAF AMENDMENTS WILL BE LIKELY. EXPECT ISOLATED
CONVECTIVE COVERAGE TO INCREASE ALONG A SURFACE TROUGH DROPPING
SOUTHWARD OUT OF THE OKLAHOMA PANHANDLE OVERNIGHT. THERE WILL LIKELY
BE A LULL IN CONVECTIVE ACTIVITY TOMORROW MORNING BEFORE THE NEXT
ROUND OF STORMS DEVELOP DURING THE EARLY AFTERNOON. HAVE CARRIED
PROB30 GROUPS FOR THIS NEXT ROUND OF CONVECTION.
&&
.PREV DISCUSSION... /ISSUED 431 PM CDT SUN AUG 9 2015/
DISCUSSION...
A WEAK BOUNDARY SLOWLY SAGGING SOUTH SHOULD BE THE FOCUS FOR STORM
DEVELOPMENT THIS AFTERNOON AND INTO THE OVERNIGHT HOURS. STORMS COULD
ALSO DEVELOP ALONG AN AREA OF CONVERGENCE FROM CANADIAN TO BUSHLAND.
THIS DEVELOPMENT IS SHOWN IN THE HRRR OUTPUT, BUT MORNING CLOUD
COVER HAS SLOWED THE WARMING IN THESE AREAS WHICH MAY DELAY THE
INITIATION TO LATER IN THIS EVENING. ANY STORMS THAT DO DEVELOP ALONG
THIS CONVERGENCE AREA SHOULD MOVE OFF INTO WESTERN OKLAHOMA LATER
THIS EVENING AS A WEAK SHORTWAVE SEEN IN WATER VAPOR IMAGERY OVER
SOUTHERN NEW MEXICO ROUND THE RIDGE. THIS SHORTWAVE SHOULD ALSO HELP
CONVECTION TO DEVELOP ALONG THE SOUTHWARD MOVING BOUNDARY. BOTH
ROUNDS OF STORMS SHOULD HAVE THE POTENTIAL TO BECOME STRONG TO
MARGINALLY SEVERE WITH AROUND 2000 J/KG AND DEEP LAYER SHEAR AROUND
20-25KT. HEAVY RAIN WILL ALSO BE OF CONCERN WITH ANY STORM THAT
DEVELOPS. PWAT VALUES OVERNIGHT CONTINUE TO HOVER RIGHT AROUND THE
+2SD FOR THIS TIME OF YEAR. WHILE AVERAGE FORECAST AMOUNTS RANGE FROM
A QUARTER OF AN INCH UP TO THREE QUARTERS OF AN INCH, THERE REMAINS
AS RISK FOR LOCALIZED AMOUNTS UP TO 1.5 INCHES WITH THE STORMS
THROUGH MONDAY MORNING.
A FEW LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE FOR THE
MONDAY MORNING COMMUTE BUT RAINFALL AMOUNTS FROM THESE STORMS SHOULD
BE LESS THAN THE OVERNIGHT STORMS. AFTER A BRIEF LULL AROUND MIDDAY
THE NEXT ROUND OF STORMS IS EXPECTED TO DEVELOP AS THE UPPER LEVEL
FLOW BECOMES MORE NORTHWESTERLY. THE WIND SHIFT, WHILE MOSTLY SOUTH
OF THE PANHANDLES, SHOULD STILL BE POSITIONED TO ALLOW SIZABLE
ISENTROPIC UPGLIDE MONDAY AFTERNOON INTO TUESDAY. THE THOUGHT OF A
FLASH FLOOD WATCH FOR MONDAY AFTERNOON INTO TUESDAY MORNING
CONTINUES TO COME UP BUT THERE HAS BEEN SIGNIFICANT DISCREPANCIES
BETWEEN MODEL RUNS. YESTERDAY THE GFS SHOWED UP TO 3 INCHES FOR THE
NORTHWEST AND SHOWS AROUND AN INCH STORM TOTAL (JUST LIKE THE ECMWF
SHOWED YESTERDAY). TODAY IT`S THE MORNING NAM WHICH SHOWS 2-4 INCHES
ACROSS THE WESTERN OKLAHOMA PANHANDLE WITH EVEN HIGHER AMOUNTS IN
SOUTHEASTERN COLORADO (ALTHOUGH THE 18Z RUN HAS ALREADY BEGUN TO
BACK OFF ON THESE AMOUNTS). AS A RESULT OF THESE DISCREPANCIES WILL
HOLD OFF ON ISSUING A WATCH UNTIL THE IMPACTED AREA CAN BE NARROWED
DOWN. RAINFALL AMOUNTS WITH THIS ROUND ARE EXPECTED TO BE HIGHEST
ACROSS THE NORTHERN TEXAS AND OKLAHOMA PANHANDLES AND RANGE BETWEEN
THREE QUARTERS OF AN INCH UP TO 1.5 INCHES WITH LOCALLY HIGHER
AMOUNTS POSSIBLE. AMOUNTS ACROSS THE SOUTHERN TEXAS PANHANDLE LOOK TO
RANGE BETWEEN A QUARTER OF AN INCH UP TO THREE QUARTERS OF AN INCH
WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
WEDNESDAY THROUGH THE REST OF THE WEEK...THE RIDGE CONTINUES TO MOVE
INTO THE CONTINENTAL DIVIDE TO KEEP THE PANHANDLES WITH A NORTH-
NORTHWEST FLOW REGIME ALOFT. THIS WILL KEEP OFF AN ON RAIN CHANCES IN
THE FORECAST AND SLIGHTLY COOLER TEMPERATURES THROUGH THE END OF THE
WEEK.
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
14
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
637 PM CDT SUN AUG 9 2015
.AVIATION.../00Z TAF CYCLE/
VFR SKC ACROSS MUCH OF THE REGION WITH ONLY A FEW/SCT250 CIRRUS
CLOUDS AS OF 09/2330Z. VFR WILL CONTINUE UNTIL 09Z OR SO WITH
DEVELOPMENT OF MVFR STRATUS CLOUDS INVOF KSAT/KSSF AND KAUS THROUGH
14-15Z. HIGHEST CONFIDENCE EXISTS FOR SAT/SSF PER SOUNDING ANALYSIS
AND HRRR OUTPUT. KAUS COULD ALSO BE IMPACTED WITH BKN015 CIGS BUT
MAY BE MORE SPORADIC. KDRT SHOULD STAY VFR THROUGH THE NIGHT BUT
STRATUS WAS CLOSE BY THIS MORNING AND THIS TREND WILL NEED TO
MONITORED IN THE 06Z TAF ISSUANCE. CURRENT SURFACE WINDS OF 10-15 KT
OUT OF THE SE WILL CALM TO 5-10KT OVERNIGHT. VFR CONDITIONS WILL
PREVAIL MONDAY AFTER 15Z WITH A REPEAT OF TODAY.
&&
.PREV DISCUSSION... /ISSUED 240 PM CDT SUN AUG 9 2015/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE THIS AFTERNOON. CURRENT
HEAT ADVISORY WILL EXPIRE THIS EVENING. PEAK HEATING HAS YET TO
OCCUR BUT LOOKS LIKE A FEW SPOTS WILL HIT ADVISORY CRITERIA MAINLY
OVER THE FAR EAST...DECENT MIXING ACROSS THE REST OF THE AREA WILL
DROP DEW POINTS THROUGH THE DAY. MILD NIGHT TONIGHT WITH A REPEAT
OF STRATUS FORMATION ACROSS CENTRAL SECTIONS WITH STRONGER LOW LEVEL
SOUTHERLY FLOW. ANOTHER HOT DAY ON MONDAY BUT THE UPPER RIDGE WILL
START A WESTWARD MOVEMENT THAT WILL BRING SLIGHT ADJUSTMENTS TO POP
AND TEMPS LATER IN THE WEEK. FAIRLY LOW DEWPOINTS WILL GENERALLY
KEEP AREA HEAT INDEX VALUES JUST BELOW HEAT ADVISORY CRITERIA
LEVELS. A WEAK FRONT WILL PUSH SOUTH INTO THE RED RIVER
AREA...HELPING TO DECREASE THE GRADIENT MONDAY NIGHT AND LIMIT THE
EARLY MORNING CLOUD COVER BY TUESDAY.
LONG TERM (TUESDAY THROUGH SUNDAY)...
AS THE UPPER RIDGE SHIFTS WEST BY MID WEEK...A SIMILAR
PATTERN WILL DEVELOP LIKE THE END OF JULY. A WEAK BACKDOOR COOL
FRONT WILL PUSH INTO EAST AND NE TEXAS AS MID AND UPPER FLOW BECOMES
INCREASINGLY EASTERLY/NORTHEASTERLY. RH TIME SECTIONS SHOWS AN
INCREASE IN MID LEVEL MOISTURE STARTING LATE TUE INTO WED. THIS
MOISTURE INCREASE...ALONG WITH THE EXPECTED HOT TEMPS...SHOULD BE
ENOUGH TO FIRE UP ISOLATED/SCT CONVECTION DURING THE
AFTERNOON/EVENING HOURS ON WED AND AGAIN ON THU. LIKE THE PREVIOUS
SYSTEM ABOUT 10 DAYS AGO...STORMS COULD PRODUCE SOME STRONG
DOWNDRAFTS...WITH SEVERAL OUTFLOW BOUNDARIES LIKELY HELPING TO
INITIATE ADDITIONAL STORMS. THIS MID LEVEL MOISTURE WILL PUSH WEST
THROUGH THE WEEK...AND BY WEEKS END...POP WILL BE CONFINED TO THE
FAR WEST AND NORTHWEST.
BY THE WEEKEND AND EARLY NEXT WEEK...LONG RANGE MODELS ARE SHOWING
AN UPPER LOW OVER THE SE U.S. MOVING WEST ALONG THE NORTHERN GULF
COAST...MOVING TOWARD THE TEXAS COAST. LOWERING 500MB HEIGHTS AND
BETTER MOISTURE LEVELS WILL KEEP THE INTENSE HEAT AWAY...BUT THE
HIGHER DEWPOINTS MIGHT ACTUALLY KEEP HEAT INDEX VALUES PLENTY WARM.
CANT RULE OUT SOME CHANCES OF RAIN ESPECIALLY IN THE COASTAL PLAINS
DUE TO THE PROXIMITY OF THE UPPER LOW. THE HOPE WILL BE FOR THIS
SYSTEM AND MOISTURE TO PUSH FARTHER INLAND AND GIVE SOME RAIN
CHANCES BEYOND THE 7 DAY PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 103 76 102 78 101 / 0 0 0 0 -
AUSTIN BERGSTROM INTL AIRPORT 102 74 101 74 101 / 0 0 0 0 -
NEW BRAUNFELS MUNI AIRPORT 101 77 102 76 101 / 0 0 0 0 0
BURNET MUNI AIRPORT 101 73 101 76 101 / 0 0 0 0 -
DEL RIO INTL AIRPORT 103 77 102 77 103 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 102 75 102 77 102 / 0 0 0 0 -
HONDO MUNI AIRPORT 101 74 101 74 102 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 101 76 100 75 101 / 0 0 0 0 -
LA GRANGE - FAYETTE REGIONAL 101 75 101 77 103 / 0 0 0 0 10
SAN ANTONIO INTL AIRPORT 101 78 101 77 101 / 0 0 0 0 0
STINSON MUNI AIRPORT 101 77 102 76 101 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BASTROP...BEXAR...CALDWELL...COMAL...DE WITT...
DIMMIT...FAYETTE...FRIO...GONZALES...GUADALUPE...HAYS...KARNES...
LAVACA...LEE...MEDINA...TRAVIS...WILLIAMSON...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...ALLEN
SYNOPTIC/GRIDS...OAKS
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
234 PM CDT SAT AUG 8 2015
.SHORT TERM...
BIGGEST CHANGE FROM EARLIER FORECASTS WAS TO EXPAND ISOLATED STORM
MENTION EASTWARD ACROSS MUCH OF THE CAPROCK THIS EVENING. EARLY
AFTERNOON ANALYSIS INDICATES A FAVORABLE COLLOCATION OF SURFACE
TROUGHING AND STEEP MID-LEVEL LAPSE RATES JUST WEST OF THE TX-NM
BORDER. SURFACE DEWPOINTS AREA WIDE ARE RUNNING 5-15 DEGS HIGHER
THAN THIS TIME YESTERDAY AND ARE YIELDING 1000-2000 J/KG OF MLCAPE
ACROSS THE SOUTH PLAINS. ALREADY NOTICING SOME CU BUILDING SOUTH OF
CVS AT 19Z AS DEEP MIXING THERE CATAPULTS PARCELS TO THEIR CCL
LEVELS. THIS THEME SHOULD EXPAND SOUTHWARD ALONG THE SURFACE TROUGH
WITH A FEW STORMS LIKELY TO BE DOTTING OUR WESTERN ZONES BY LATE
AFTERNOON. AS THESE PULSE-TYPE CELLS MOVE SLOWLY NORTHEAST...OUTFLOW
REGENERATION OF NEW STORMS SEEMS PLAUSIBLE THROUGH EARLY EVENING IN
LIGHT OF MEAGER CIN. HRRR HAS BEEN QUITE ADAMANT IN BLOSSOMING A
LARGER COVERAGE OF STORMS BEFORE SUNSET...BUT WITH NO DISCERNIBLE
BACKGROUND SUPPORT AVAILABLE IT SEEMS A SAFER BET TO KEEP PRECIP
MENTION ON THE ISOLATED SIDE. A DECENT NOCTURNAL LLJ MAY KEEP SOME
SEMBLANCE OF THESE EARLIER STORMS INTACT AFTER MIDNIGHT.
SUNDAY WILL SEE A TALL AND CLOSED ANTICYCLONE RETROGRADE TO CENTRAL
TEXAS COMPLETE WITH RISING HEIGHTS AND THICKNESSES LOCALLY. THIS
PROCESS WILL HELP REORIENT THE SURFACE TROUGH FROM N-S TO NE-SW
ACROSS THE WRN TX PANHANDLE INTO ERN NM. BEST STORM CHANCES SHOULD
PLAY OUT IN THE NRN PANHANDLE NEAR THE INTERSECTION OF THE TROUGH
AND A STALLING FRONT...BUT DEEP MIXING AND WEAK CAPE IN OUR NW
COUNTIES COULD SPUR A FEW LATE AFTERNOON STORMS. OTHERWISE...MAX
TEMPS LOOK TO SHAKE OUT A DEGREE OR TWO WARMER THAN TODAY.
.LONG TERM...
UPPER LEVEL RIDGE IS EXPECTED TO BE CENTERED OVER EAST
TEXAS SUNDAY EVENING WHILST VIGOROUS UPPER LEVEL LOW SLIDES DOWN THE
COAST OF BRITISH COLUMBIA. THE STRENGTH OF THE RIDGE IS EXPECTED TO
BE SUFFICIENTLY STRONG TO HOLD THE LOW OFF THE PACIFIC NORTHWEST
COAST AT LEAST THROUGH 120 HOURS BEFORE IT EJECTS NEWRD INTO SRN
CANADA. TO OUR NORTH A SHORTWAVE PASSES EARLY MONDAY ACROSS THE
CENTRAL PLAINS FOLLOWED BY ANOTHER SURGE OF ENERGY ROTATING ABOUT
HUDSON BAY LOW EARLY TUESDAY BEFORE RIDGE BUILDS STRONGLY ALL THE
WAY UP TO NUNAVUT. AS THE HIGH SLOWLY RETROGRADES...FLOW WILL
BECOME MORE NORTHERLY TO NORTHEASTERLY WITH TIME AND THIS SHOULD
HELP COOL TEMPS A BIT IN THE LATTER EXTENDED.
BEST RAIN CHANCES DURING THE EXTENDED WILL EXIST FROM SUNDAY EVENING
INTO TUESDAY AS FRONTAL BOUNDARY SAGS INTO THE REGION. HIGHEST
POTENTIAL WILL EXIST NORTH AND WEST. TRENDS HAVE BEEN EDGING THE
BOUNDARY FURTHER SOUTH WITH EACH RUN AND THIS CERTAINLY FITS THE
PATTERN THIS SUMMER. THINGS LOOK TO DRY OUT ON WEDNESDAY WITH
PERHAPS A FEW SCT SHOWERS NEAR THE ESCARPMENT BUT OVERALL TRENDING
DRIER FOR THE REMAINDER OF THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 94 67 90 / 20 20 20 30
TULIA 66 95 68 92 / 20 0 20 30
PLAINVIEW 65 95 70 93 / 20 0 10 20
LEVELLAND 68 96 70 95 / 20 0 10 20
LUBBOCK 71 98 72 96 / 20 0 10 10
DENVER CITY 68 98 69 96 / 20 0 10 10
BROWNFIELD 68 98 70 96 / 20 0 10 10
CHILDRESS 73 102 75 99 / 0 0 10 20
SPUR 70 101 72 99 / 0 0 10 0
ASPERMONT 75 104 75 103 / 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
93/26
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 241 PM CDT SAT AUG 8 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SURFACE
HIGH PRESSURE CENTERED OVER NORTHERN LAKE MICHIGAN...AND NOSING INTO
THE SOUTHERN PART OF THE STATE. MEANWHILE...A COLD FRONT IS SLOWLY
MOVING INTO NE MINNESOTA WHERE SMALL CLUSTERS OF THUNDERSTORMS
OCCASIONALLY DEVELOP. A FEW OTHER STORMS HAVE FIRED OVER SOUTHERN
MINNESOTA IN A WARM ADVECTION ZONE. OTHERWISE...LOW LEVEL COOL AIR
HAS DELAYED CLEARING ACROSS MUCH OF THE REGION EXCEPT FOR FAR N-C
WISCONSIN WHERE SKIES ARE STARTING TO CLEAR. AREAS OF SPRINKLES OR
LIGHT RAIN ARE FALLING OUT OF A MID-DECK OVER WESTERN AND SOUTHERN
WISCONSIN...BUT HAVE BEEN DISSIPATING AS THEY APPROACH CENTRAL
WISCONSIN. FORECAST CONCERNS INCLUDE CLOUD TRENDS AND THUNDERSTORM
POTENTIAL OVER THE NEXT 24 HOURS.
TONIGHT...MID-LEVEL WARM ADVECTION WILL RAMP UP OVER SOUTHWEST
WISCONSIN...WHILE A COLD FRONT SAGS INTO NORTHWEST WISCONSIN LATE.
THE MAJORITY OF SHORT-TERM GUIDANCE SUGGESTS ANY CONVECTION THAT
DEVELOPS OVER SOUTHERN MINNESOTA AND NORTHERN IOWA WILL DROP TO THE
SOUTHEAST OF THE AREA TONIGHT. A BETTER CHANCE OF SHOWERS AND
STORMS LOOK TO OCCUR OVER N-C WISCONSIN ALONG THE FRONT WHERE
ELEVATED INSTABILITY WILL SHIFT INTO LATE IN THE NIGHT. THIS SEEMS
REASONABLE SINCE ISOLATED CONVECTION HAS BEEN OCCURRING ALL DAY OVER
NE MINNESOTA. SO LEFT A SLIGHT CHANCE TO ACCOUNT FOR THAT.
OTHERWISE...CLOUD TRENDS CONTINUE TO POSE A HEADACHE. EAST TO
SOUTHEAST LOW LEVEL FLOW WILL CONTINUE TO COLD ADVECT THROUGH THE
EVENING OVER EASTERN WISCONSIN...BELOW A WARM LAYER CENTERED AROUND
850MB. THIS WOULD ARGUE TO SLOW DOWN THE CLEARING TREND LATER THIS
AFTERNOON AND EVENING. IF CLEARING DOES OCCUR...PATCHY FOG COULD
BECOME AN ISSUE...BUT THATS MAINLY OVER CENTRAL AND N-C WI. LOWS IN
THE UPPER 50S TO LOW 60S.
SUNDAY...WEAK MID-LEVEL WARM ADVECTION WILL SPREAD OVER NORTHEAST
WISCONSIN AS THE COLD FRONT STALLS ACROSS NW WISCONSIN. COULD HAVE
A FEW LIGHT SHOWERS/SPRINKLES GRAZE THE SOUTHERN FORECAST AREA IN
THE WARM ADVECTION ZONE...MAINLY IN THE MORNING. MOST OF THE
ATTENTION WILL BE PLACED ON THE COLD FRONT THOUGH. ISOLATED
CONVECTION WILL OCCUR ACROSS N-C WISCONSIN DURING THE
MORNING...BEFORE INSTABILITY BUILDS THROUGH THE AFTERNOON. PROGGED
SOUNDINGS INDICATE AMPLE INSTABILITY (ML CAPE UP TO 2000 J/KG)...BUT
0-6KM BULK SHEARS ARE ONLY AROUND 20 KTS. THESE PROGGED CONDITIONS
WOULD ARGUE FOR PULSE TYPE STORMS...WITH A FEW STRONG OR ISOLATED
SEVERE STORMS POSSIBLE. THE BEST COVERAGE OF STORMS APPEARS TO BE
AFTER 3 PM IN THE AFTERNOON. HIGHS RANGING FROM THE UPPER 70S NORTH
TO MID 80S SOUTH.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 241 PM CDT SAT AUG 8 2015
A WEAK LOW PRESSURE SYSTEM OVER MANITOBA WILL MOVE EAST TO
SOUTHERN HUDSON BAY DURING THE NEXT COUPLE OF DAYS. THE LOW WILL
DRAG A COLD FRONT ACROSS WISCONSIN. THERE WILL BE A CHANCE FOR
SHOWERS AND THUNDERSTORMS AHEAD OF AND ALONG THE FRONT...ENDING
MONDAY AFTERNOON AS NORTHWEST WINDS FOLLOW IN AND MOISTURE GETS
SCOURED OUT OF THE AREA. ONLY AN ISOLATED SHOWER OR TWO IS
EXPECTED MONDAY NIGHT.
AFTER THE FRONT MOVES ON BY...A HIGH PRESSURE RIDGE WILL
STRENGTHEN OVER THE U.S. PLAINS STATES/MIDWEST. THE LONGWAVE
PATTERN OVER NORTH AMERICA WILL BECOME INCREASINGLY AMPLIFIED AND
A LOW PRESSURE TROUGH WILL EXPAND SOUTH OVER THE EASTERN UNITED
STATES. THIS PATTERN WILL PRODUCE A NORTHWEST FLOW OVER WISCONSIN
AND CREATE CONSIDERABLE UNCERTAINTY IN PRECIPITATION PREDICTION
FOR THE WORK WEEK. HOWEVER...THE PREDICTION OF TEMPERATURES
SHOULD BE RELIABLY WITHIN THE NORMAL TO SLIGHTLY BELOW NORMAL
RANGE FOR THIS TIME OF THE YEAR THROUGH NEXT WEEKEND. THE BLEND
OF MODELS SUGGESTS THAT...AFTER MONDAY...THE NEXT SIGNIFICANT
CHANCE FOR PRECIPITATION COMES ON FRIDAY AS A SHORTWAVE RIDES DOWN
ON THE NORTHWEST FLOW OUT OF CANADA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1206 PM CDT SAT AUG 8 2015
CIGS WILL GRADUALLY RISE THIS AFTERNOON WITH FURTHER
DAYTIME HEATING. CENTRAL AND N-C WI WILL SEE SLOWER IMPROVEMENT
THAN TAF SITES OVER EASTERN WI. MOSTLY VFR TONIGHT...THOUGH VSBYS
WILL LIKELY DROP LATE TONIGHT DUE TO A COMBO OF LIGHT WINDS AND HIGH
HUMIDITY. A COLD FRONT WILL MOVE INTO NORTH-CENTRAL WISCONSIN ON
SUNDAY BRINGING A THREAT OF SHOWERS AND STORMS. IMPACTS COULD BE
FELT AS EARLY AS MID-MORNING AT RHI BUT UNCERTAINTY OF TIMING IS
RATHER HIGH. ANY STORMS ARE NOT EXPECTED TO REACH INTO CENTRAL OR
EAST-CENTRAL WI TAF SITES UNTIL LATE IN THE DAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ML
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1154 PM CDT FRI AUG 7 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 312 PM CDT FRI AUG 7 2015
SEVERAL CONCERNS WITH THE FORECAST DURING THIS PERIOD. THE FIRST
COMES TONIGHT AND WHETHER THERE WILL BE ANY VALLEY FOG OR NOT. IN
FAVOR OF THE FOG FORMING IS THE LITTLE BIT OF RAIN THIS MORNING
AND THE CLOUDS THAT HAVE TRAPPED THIS MOISTURE. THE 07.12Z NAM IS
THE MOST AGGRESSIVE WITH SHOWING SATURATION OCCURRING AT THE
SURFACE FOR THE VALLEY LOCATIONS. THE NAM ALSO HAS THE MOST AMOUNT
OF WIND JUST ABOVE THE SURFACE FOR MORE MIXING...WHICH GOES
AGAINST FOG FORMATION. 07.17Z RAP SOUNDINGS WHILE HAVING A DEEPER
LAYER OF LIGHT WINDS...COMES CLOSE TO SATURATING AT THE SURFACE
AND THEN REALLY DRIES OUT JUST ABOVE THE SURFACE. THE 07.12Z GFS
IS EVEN DRIER THAN THE RAP...SO HAVE DOUBTS THAT THERE WILL BE A
LOT OF FOG IN THE VALLEYS TONIGHT. ANOTHER COMPLICATING FACTOR
COULD BE THE INCREASE IN HIGH LEVEL CLOUDS FOR LATE TONIGHT AHEAD
OF AN APPROACHING SHORT WAVE TROUGH. PATCHY VALLEY FOG WAS ALREADY
IN THE FORECAST AND DO NOT PLAN TO MAKE ANY CHANGES TO THIS.
WITH THE APPROACHING SHORT WAVE TROUGH...THE GFS SEEMS TO HAVE THE
MOST SUPPORT FROM THE OTHER MODELS WITH THE 07.12Z ECMWF LOOKING
SIMILAR ALONG WITH THE 07.12Z HI-RES ARW AND NMM. WATER VAPOR
SATELLITE INDICATES THIS WAVE IS COMING OUT OF THE ROCKIES OVER
EASTERN WYOMING AND NORTHERN COLORADO THIS AFTERNOON AND SHOULD
THEN TRACK EAST ACROSS IOWA INTO SOUTHERN WISCONSIN AND NORTHERN
ILLINOIS BY LATE SATURDAY MORNING. THE GFS SUGGESTS THIS WAVE WILL
PRODUCE SOME WEAK TO MODERATE PV ADVECTION IN THE 500-300 MB LAYER
ACROSS NORTHEAST IOWA INTO FAR SOUTHERN WISCONSIN LATE TONIGHT
INTO EARLY SATURDAY MORNING. THE BOUNDARY THAT WENT THROUGH TODAY
SHOULD BE HUNG UP OVER CENTRAL IOWA AND IT IS EXPECTED THAT WEAK
TO MODERATE FRONTOGENESIS WILL OCCUR NORTH OF THIS BOUNDARY. THE
BEST ISENTROPIC UP GLIDE ON THE 310K SURFACE IS EXPECTED TO
REMAIN SOUTH OF THE BOUNDARY ACROSS CENTRAL AND SOUTHERN IOWA WITH
POSSIBLY 1 TO 2 UBAR/S OVER NORTHEAST IOWA. THE GENERAL CONSENSUS
AMONG THE MODELS IS THAT A COMPLEX OF SHOWERS AND STORMS SHOULD
FORM OVER NEBRASKA TONIGHT AND MOVE EAST ALONG AND NORTH OF THE
BOUNDARY. THE GFS AND HI-RES ARW AND NMM WOULD SUGGEST THERE IS AT
LEAST A CHANCE THAT THIS COMPLEX SURVIVES LONG ENOUGH TO GET INTO
THE SOUTHERN PARTS OF THE FORECAST AREA WHILE THE 07.12Z ECMWF
STARTS TO DISSIPATE THE COMPLEX AND ONLY BRINGS IN SOME REMAINS
SATURDAY AFTERNOON ACROSS THE SOUTH. WILL BRING IN SOME 20 TO 40
PERCENT CHANCES ACROSS NORTHEAST IOWA SATURDAY MORNING FOR THIS
COMPLEX.
ANOTHER SHORT WAVE TROUGH IS THEN EXPECTED TO COME OUT OF THE
ROCKIES AND TRACK ACROSS THE REGION SATURDAY NIGHT. THE TRACK AND
FORCING LOOK TO BE VERY SIMILAR TO THE WAVE FOR LATE TONIGHT INTO
SATURDAY MORNING WITH THE EXCEPTION THAT THE SURFACE BOUNDARY
SHOULD GET PUSHED FARTHER SOUTH INTO SOUTHERN IOWA OR NORTHERN
MISSOURI. THE COMPLEX OF STORMS WITH THIS NEXT WAVE IS EXPECTED TO
FORM OVER SOUTHWEST IOWA AND THEN TRACK EAST AND SHOULD LARGELY
STAY TO THE SOUTH OF THE FORECAST AREA. THE GFS IS SLIGHTLY
FARTHER NORTH THAN THE ECMWF AND TO HONOR THIS WILL HAVE SOME 20
TO 40 PERCENT CHANCES FROM ABOUT INTERSTATE 90 SOUTH.
BY SUNDAY NIGHT THE MEAN RIDGE WILL BE TRYING TO BUILD OVER THE
ROCKIES WITH AN UPPER LEVEL LOW OVER NORTHERN ONTARIO. THIS WILL
START TO SET UP A NORTHWEST FLOW OVER THE REGION WITH THE
POSSIBILITY OF A WEAK SHORT WAVE TROUGH ROTATING AROUND THE UPPER
LEVEL LOW AND ACROSS THE AREA. THE FORCING WITH THIS WAVE LOOKS TO
BE RATHER WEAK...BUT IT COULD PUSH A WEAK SURFACE BOUNDARY INTO
THE AREA WITH THE POSSIBILITY OF SOME ACTIVITY ALONG IT. WILL
CARRY SOME 30 TO 40 PERCENT CHANCES SUNDAY FOR THIS FEATURE WITH
SOME LINGERING 20 TO 30 PERCENT CHANCES INTO SUNDAY NIGHT.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 312 PM CDT FRI AUG 7 2015
ONCE THE SHORT WAVE TROUGH FROM SUNDAY NIGHT EXITS THE AREA...A
LARGE AREA OF HIGH PRESSURE WILL BUILD IN OVER THE UPPER MIDWEST.
THIS HIGH LOOKS TO DOMINATE THE REGION FROM MONDAY NIGHT THROUGH
WEDNESDAY NIGHT. THE ECMWF WOULD SUGGESTS IT HOLDS TIGHT OVER THE
REGION THROUGH THE END OF THE WEEK WHILE THE GFS BRINGS A COLD
FRONT ACROSS THE UPPER MIDWEST THURSDAY THROUGH FRIDAY. WILL JUST
CARRY SOME LOW 20 TO 30 PERCENT RAIN CHANCES LATE IN THE PERIOD TO
HONOR THE GFS SOLUTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1154 PM CDT FRI AUG 7 2015
STILL HAVE SOME CONCERN ABOUT VALLEY FOG AFFECTING KLSE OVERNIGHT.
THE TEMPERATURE/DEW POINT DEPARTURE IS CURRENTLY 4 DEGREES AND THE
WINDS ARE CALM AT THE OFFICE. THIS WOULD BE FAVORABLE FOR VALLEY
FOG. HOWEVER SOME MID TO HIGH LEVEL DEBRIS CLOUDS /FROM
CONVECTION IN THE DAKOTAS/ WILL BE MOVING SOUTHEAST INTO THE AREA
TONIGHT AND THE COMBINATION OF THESE CLOUDS ALONG WITH INCREASING
WINDS ALOFT MAY INHIBIT VALLEY FOG. DUE TO THIS...JUST OPTED TO
ADD BCFG TO THE TAF BETWEEN 08.10Z AND 08.14Z.
ON SATURDAY AND SATURDAY EVENING...A SHORT WAVE TROUGH MOVING EAST
ACROSS IOWA WILL KEEP MID CLOUDS ACROSS THE AREA THROUGH THIS TIME
PERIOD. WINDS THROUGHOUT THE PERIOD WILL BE SOUTHERLY AND LESS
THAN 10 KNOTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS RENO NV
230 AM PDT MON AUG 10 2015
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE THROUGH THIS MORNING WITH A SLIGHT
CHANCE OF THUNDERSTORMS NORTH OF INTERSTATE 80. SOUTH FLOW THEN
RESUMES MONDAY AFTERNOON AS LOW PRESSURE DROPS OFF THE WEST
COAST. DRY CONDITIONS WITH TYPICAL AFTERNOON BREEZES AND NEAR
NORMAL TEMPERATURES ARE EXPECTED. WINDY CONDITIONS ARE POSSIBLE
THURSDAY AS THE LOW MOVES INTO OREGON.
&&
.SHORT TERM...
WATER VAPOR AND IR SATELLITE IMAGERY SHOW A DEFINED UPPER LEVEL
DISTURBANCE MOVING INTO THE CALIFORNIA INTERIOR THIS MORNING. AS A
RESULT, ISOLATED VIRGA SHOWERS HAVE FORMED NORTH OF THE TAHOE
BASIN NORTHWARD INTO NORTHERN LASSEN COUNTY. THE HRRR AND NAM
CONCUR THAT ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
THROUGH MID MORNING TODAY AS THIS WAVE MOVES NORTHWARD. ANY
THUNDERSTORMS THAT DO RESULT WILL BE DRY WITH DRY LIGHTNING THE
PRIMARY THREAT. NEW FIRE STARTS WILL BE POSSIBLE, BUT COVERAGE OF
CELLS DOES NOT WARRANT A RED FLAG WATCH OR WARNING.
AS FOR CONSIDERATIONS INVOLVING THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, HAVE EXTENDED AREAS OF SMOKE THROUGH MID
MORNING IN SOUTHERN MONO COUNTY WITH HAZE PERSISTING INTO THE
AFTERNOON. FIRE ACTIVITY THIS MORNING WILL DETERMINE WHETHER OR
NOT THESE CONDITIONS PERSIST INTO TUESDAY.
OTHERWISE, LOW PRESSURE DEEPENS AND DROPS SOUTH IN THE EASTERN
PACIFIC WITH HIGH PRESSURE LOCATED OVER THE WESTERN PLAINS OF THE
UNITED STATES. THIS LEAVES THE SIERRA AND WESTERN NEVADA IN A
NEUTRAL PRESSURE ADVECTION REGION RESULTING IN GENERALLY BENIGN
WEATHER CONDITIONS. MOISTURE TRANSPORT VECTORS ARE NOT FAVORABLE
FOR A MONSOONAL MOISTURE SURGE AT THIS TIME. THE MOST SIGNIFICANT
IMPACTS THROUGH MID WEEK WILL COME FROM DRIER SOUTH TO WESTERLY
FLOW EACH AFTERNOON WITH LOCALLY BREEZY CONDITIONS FROM TYPICAL
AFTERNOON ZEPHYRS. AS SEEN WITH THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, THESE WINDS AND DRY CONDITIONS COULD
ACTIVATE HOLDOVERS ALLOWING FOR RAPID FIRE GROWTH. BOYD
.LONG TERM...THURSDAY THROUGH SUNDAY...
MEDIUM RANGE OPERATIONAL MODELS ARE IN GOOD AGREEMENT AGAIN THIS
CYCLE THROUGH EARLY SATURDAY. AFTER THAT DIFFERENCES APPEAR...AS
THEY HAVE BEEN DOING SO FOR THE PAST FEW DAYS. UPPER LOW MOVES INTO
THE PAC NW ON THURSDAY WITH STRONG LOW LEVEL PRESSURE AND THERMAL
GRADIENTS OVER THE NORTHERN PART OF THE FORECAST AREA NORTH INTO
OREGON. THESE STRONG GRADIENTS SHOULD DRIVE GUSTY WEST TO SOUTHWEST
WINDS OVER THE NORTHERN 2/3RDS OF THE FORECAST AREA THURSDAY
AFTERNOON AND EVENING. INCREASED MIXING WILL PUSH TEMPS AT OR ABOVE
AVERAGE FOR ALL BUT THE FAR NORTHERN FORECAST AREA AND HUMIDITY
VALUES SHOULD BE FAIRLY LOW. THIS COMBINATION WILL LIKELY PRODUCE
CRITICAL FIRE WEATHER CONDITIONS FOR AT LEAST THE AREA NORTH OF
HIGHWAY 50.
UPPER LOW MOVES EAST FRIDAY WITH A LESSENING OF THE GRADIENT AND
ATTENDANT WINDS. TEMPS WILL ALSO DECREASE OVER FAR NORTHERN AREAS OF
THE CWA. DRY SOUTHWEST FLOW WILL KEEP ANY MENTION OF PCPN OUT OF THE
FORECAST THROUGH AT LEAST SATURDAY. THE OPERATIONAL MODELS START TO
DIVERGE SATURDAY WITH THE GFS HOLDING ON TO THE TROUGH A BIT LONGER
WHILE THE ECMWF STARTS TO WEAKEN THE TROUGH AND BUILD A FLAT RIDGE.
BY SUNDAY THE ECMWF IS MORE AGGRESSIVE BUILDING THE RIDGE AND THE
GFS MAINTAINS A WEAK TROUGH. THE GEFS ENSEMBLE MEMBERS SHOW SOME
SUPPORT FOR BOTH SOLUTIONS SO A COMPROMISE WAS MADE. THIS MEANT
KEEPING THE HIGH TEMPS BELOW THE ECMWF GUIDANCE FOR SATURDAY AND
SUNDAY.
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST. IF THE ECMWF
SOLUTION IS MORE CORRECT THEN WE MIGHT SEE AND OUTSIDE CHANCE AT
WEAK CONVECTION OVER THE FAR SOUTHERN CWA BY SUNDAY AS LIGHT UPSLOPE
FLOW BRINGS A BIT MORE MOISTURE BACK TO THE REGION. OTHERWISE DRY
WITH NEAR SEASONAL TEMPERATURES FOR THE EXTENDED PERIOD AND TYPICAL
AFTERNOON WINDS ONCE WE GET PAST THURSDAY. 20
&&
.AVIATION...
A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING
NORTH OF INTERSTATE 80 AS AN UPPER LEVEL WAVE OF LOW PRESSURE MOVES
NORTH. OUTSIDE OF THE WAVE THERE SHOULD BE VFR CONDITIONS TODAY.
TYPICAL SUMMER AFTERNOON WINDS ARE LIKELY TODAY WITH GUSTS EAST OF
THE SIERRA IN THE 20-25 KT RANGE.
HAZE AND SMOKE FROM CALIFORNIA FIRES WILL PRODUCE PERIODS OF
LOWERED VISIBILITY TODAY AND TUESDAY.
FAIRLY LIGHT WINDS TUESDAY. RIDGE WINDS BEGIN TO INCREASE WEDNESDAY
AND THEN GUSTY WINDS DEVELOP THURSDAY AHEAD OF A SURFACE BOUNDARY
THAT MOVES THROUGH THURSDAY NIGHT. INCREASED TURBULENCE IS HIGHLY
PROBABLE FROM LATE WEDNESDAY THROUGH THURSDAY. 20
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1148 PM MDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 302 PM MDT SUN AUG 9 2015
SIGNIFICANTLY DRIER AIR WILL REMAIN OVER THE AREA OVERNIGHT. THE
12Z KGJT SOUNDING HAD PRECIPITABLE WATER OF 0.63 IN. DEWPOINTS
WILL CONTINUE TO DROP INTO THE 40S AND EVEN UPPER 30S AT SOME
LOCATIONS. CAPE VALUES ARE PROJECTED IN THE RAP13 AND HRRR TO
REMAIN LOW AS WELL...SO CONVECTION EARLY THIS EVENING WILL BE
WEAK AND ONLY OVER AND DOWNWIND OF RIDGES. ONLY LIGHT
PRECIPITATION IS EXPECTED WITH THESE STORMS ALONG WITH GUSTY
WINDS. THUNDERSTORMS SHOULD DISSIPATE WELL BEFORE MIDNIGHT WITH
NEARLY CLEAR SKIES EXPECTED AGAIN OVERNIGHT.
MOISTURE BEGINS TO INCREASE FROM THE SOUTH AGAIN ON MONDAY...SO EXPECTING
SCATTERED ACTIVITY IN THE SAN JUANS MONDAY EVENING AS THE 12Z NAM
AND GFS INDICATE A H5 VORTICITY MAX REACHING THE FOUR CORNERS
MONDAY EVENING. THE EURO IS A BIT SLOWER WITH THIS ENERGY...BUT IN
ANY CASE IT DOES LOOK LIKE SHOWERS AND ISO TSTORMS WILL CONTINUE
THROUGH THE OVERNIGHT HOURS ON MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 302 PM MDT SUN AUG 9 2015
TUESDAY MORNING WILL BE A MUGGY ONE...WITH CLOUD COVER AND RAIN
SHOWERS ACROSS MUCH OF THE REGION BY MIDDAY. MONSOONAL MOISTURE
WILL BE AT ITS HIGHEST THIS WEEK ON TUESDAY AFTERNOON AS
PRECIPITABLE WATER VALUES ACROSS THE FOUR CORNERS REACH UPWARDS OF
1.2 INCHES AND MORE THAN 0.75 INCHES REACHING THE UT/CO/WY BORDER.
THOUGH DEEP MOISTURE WILL BE IN PLACE...NOT FEELING VERY CONFIDENT
ON THE THREAT OF FLASH FLOODING SINCE WE WILL LIKELY BE DEALING
WITH WIDESPREAD CLOUD COVER AGAIN AND LACK OF LIFTING DUE TO
DAYTIME HEATING. LOCALIZED FLASH FLOODING COULD OCCUR IF THERE IS
SOME CLEARING WHICH PRODUCES ENOUGH LIFT FOR MORE VERTICALLY
SUPPORTED THUNDERSTORMS. WEDNESDAY WILL LIKELY BE MORE OF A THREAT
DAY FOR FLASH FLOODING WITH SKY CONDITIONS LESS CLOUDY BUT WITH
DEEP MOISTURE STILL IN PLACE. FORECAST CONVECTIVE INDICES ON THE
NAM ARE MORE FAVORABLE FOR HEAVY RAIN PRODUCING THUNDERSTORMS ON
WEDNESDAY THAN TUESDAY...SO THESE DAYS WILL NEED TO BE WATCHED FOR
POTENTIAL IMPACTS. THE LACK OF JET SUPPORT WILL KEEP STEERING
WINDS LIGHT THROUGH THE END OF THE WEEK SO ANY SHOWERS AND STORMS
WHICH DEVELOP WILL MOVE SLOWLY. SOME DRYING OCCURS LATER IN THE
WORK WEEK DUE TO HIGH PRESSURE AMPLIFYING OVER THE ROCKIES...BUT
PRECIPITABLE WATER VALUES REMAIN NEAR THREE QUARTERS OF AN INCH
SO DIURNALLY INDUCED SHOWERS AND THUNDERSTORMS WILL DEVELOP
EVERYDAY OVER HIGHER TERRAIN.
NEXT SATURDAY...A TROUGH OVER THE PACIFIC NORTHWEST IS PROGGED TO MOVE
INLAND NORTH OF COLORADO. THE INTERACTION OF THIS TROUGH WITH THE
HIGH PRESSURE IN PLACE OVER THE ROCKIES WILL DRIVE A 50 KT JET
INTO NE UTAH AND NW COLORADO AND POTENTIALLY CREATE MORE
CONVECTIVE ACTIVITY UP NORTH NEXT WEEKEND.
BUMPED HIGH TEMPS UP A COUPLE OF DEGREES IN THE LOWER VALLEYS
TOWARD THE END OF THE WEEK CLOSER TO MOS GUIDANCE FOR A MIDDLE
GROUND SOLUTION. FEEL THAT MOS GUIDANCE IS TOO HOT BUT PREVIOUS
FORECAST WAS TOO LOW CONSIDERING THE EXPECTED AMOUNT OF SUNSHINE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1142 PM MDT SUN AUG 9 2015
EXPECT VFR CONDITIONS THROUGH MONDAY MORNING ACROSS THE REGION.
INCREASING MOISTURE FROM THE SOUTH WILL BRING ISOLATED/SCATTERED SHOWERS
AND THUNDERSTORMS SPREADING SOUTH TO NORTH LATE MONDAY AFTERNOON
AND CONTINUING MONDAY NIGHT. THE BEST FOCUS WILL BE OVER
SOUTHWESTERN COLORADO AND SOUTHERN AND CENTRAL MOUNTAIN LOCATIONS.
STRONGER CELLS WILL HAVE CIGS OBSCURING MOUNTAIN TOPS BY LATE
MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...CC/JAM
LONG TERM...JAM
AVIATION...MPM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 AM EDT MON AUG 10 2015
.DISCUSSION...
TODAY-TONIGHT...
POPS WELL BLO CLIMO AVG IN THE WAKE OF A DISSIPATING FRONTAL
BOUNDARY OVER S FL/NRN BAHAMAS. THE TROF WILL COMBINE WITH A NARROW
H100-H70 HI PRES RIDGE SPANNING THE ERN SEABOARD TO GENERATE A DEEP
NERLY FLOW REGIME OVER THE FL PENINSULA. PATTERNS SUCH AS THIS ONE
ARE ONE OF THE MOST STABLE FOR CENTRAL FL...AND THIS ONE WILL BE NO
DIFFERENT.
A MID LVL THERMAL RIDGE ASSOCD WITH THE RIDGE CURRENTLY BLANKETS
MUCH CENTRAL FL WITH H70 TEMPS BTWN 9-10C AND H50 TEMPS ARND -5C...
YIELDING AVG LAPSE RATES ARND 5.5C/KM THRU THE LYR. H85-H70 LAPSE
RATES ARE NO BETTER WITH VALUES ARND 5C/KM. THE 00Z RAOBS AT
KJAX/KXMR SHOW PWAT VALUES BTWN 1.6"-1.7"...WHILE RAP ANALYSIS
INDICATES H100-H70 MEAN RH VALUES STRUGGLING TO HOLD THE 70PCT
LINE...H85-H50 VALUES LARGELY ARND 40PCT.
AVAILABLE MOISTURE IS SUFFICIENT TO SUPPORT ISOLD CONVECTION...AS
RADAR TREND HAS SHOWN OVER THE PAST SVRL HRS OVER THE ATLC WATERS...
BUT LITTLE MORE. FURTHERMORE...THE ONSHORE FLOW WILL PROMOTE THE
EARLY FORMATION OF THE EAST COAST SEA BREEZE THAT WILL FAVOR THE W
FL PENINSULA FOR DIURNAL CONVECTION...POPS AOB 20PCT. SEA BREEZE
KEEP COASTAL TEMPS IN THE U80S...INTERIOR TEMPS IN THE L90S. MIN
TEMPS IN THE L/M70S.
A BROADLY WEAK BERMUDA RIDGE WL ATTEMPT TO BECOME RE-ESTABLISHED
NEAR CENTRAL FL DURING TUE. THE FEATURE WL BE NUDGED SWD HOWEVER
BY AN APCHG SHORTWAVE OVERNIGHT AND INTO WED. INCRSG RAIN CHCS WL
OCCUR AT MIDWEEK WITH UPR TROUGH AND ASCD SFC BOUNDARY MOVING INTO
N FL DURING WED...INCRSG LOCAL MOISTURE AND LIKELIHOOD OF AFTN
SHOWERS AND STORMS ACROSS THE AREA. SLIGHTLY HIGHER RAIN CHCS ARE
INDICATED OVER NORTHERN COUNTIES INTO THE OVERNIGHT PERIOD WHEN
BOUNDARY IS ADVERTISED STALLING NORTH OF CENTRAL FL.
THE WEAKENING BOUNDARY WI LINGER OVER N FL INTO LATE WEEK WITH
AMPLE LAYER MOISTURE ACROSS THE REGION ALONG WITH FAVORABLE
STEERING REGIME TO PRODUCE SCT TO NMRS DIURNAL SHOWERS AND SLOW
MOVING STORMS. A GENERALLY WEAK PRESSURE PATTERN WL PREVAIL FROM
THE WEEKEND INTO NEXT WEEK BRINGING HIGHER THAN NORMAL RAIN
COVERAGE AT LEAST INTO EARLY NEXT WEEK.
&&
.AVIATION...THRU 11/12Z
WINDS: THRU 10/14Z...NE AOB 4KTS. BTWN 10/14Z-10/16Z...E/NE 7-10KTS
CONTG THRU 11/02Z. BTWN 11/02Z-11/04Z...BCMG VRBL AOB 3KTS.
VSBY/WX/CIGS: THRU 10/12Z...PTCHY MVFR BR/LCL LIFR FG VCNTY
KVRB/KFPR...BRIEF ISOLD MVFR SHRAS COASTAL SITES. BTWN 10/12Z-
10/16Z...ISOLD MVFR SHRAS COASTAL SITES. BTWN 10/16Z-10/24Z...ISOLD
IFR TSRAS INTERIOR SITES. AFT 11/04Z...SLGT CHC MVFR SHRAS BTWN KTIX-
KSUA.
&&
.MARINE...
TODAY-TONIGHT...WEAK PGRAD IN THE WAKE OF A DISSIPATING FRONTAL
TROF WILL COMBINE WITH A HIGH PRES RIDGE OVER THE DEEP SOUTH TO
GENERATE A LIGHT E/NE BREEZE TODAY...BCMG A LIGHT TO GENTLE S/SW
BREEZE OVERNIGHT AS A NEW FRONTAL BOUNDARY WORKS ITS WAY INTO
THE DEEP SOUTH. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE...
MAINLY IN AN ERLY SWELL.
PRESENCE OF A WEAK RIDGE OVER THE WATERS AT MIDWEEK WL PRODUCE
FAVORABLE BOATING CONDITIONS WITH SEAS AROUND 2 FT OR LESS NEAR
SHORE AND 2 TO 3 FT OVER THE OUTER WATERS. THESE SIMILAR
CONDITIONS CAN BE EXPECTED INTO THE WEEKEND AS WELL WITH AN
INCREASE IN STORMS NEAR THE IMMEDIATE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 88 74 92 74 / 10 0 20 20
MCO 92 74 95 75 / 20 0 30 20
MLB 88 76 91 75 / 10 10 30 20
VRB 89 73 92 73 / 20 20 30 30
LEE 93 74 94 76 / 20 10 30 20
SFB 92 73 95 76 / 20 0 30 20
ORL 93 74 94 77 / 20 0 30 20
FPR 89 72 92 72 / 20 20 30 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
526 AM EDT MON AUG 10 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL PUSH FARTHER OFF THE COAST TODAY. MOISTURE
WILL INCREASE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA LATE TUESDAY AND
TUESDAY NIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE
ASSOCIATED WITH THE FRONT. DRYING WITH A DIMINISHED SHOWER CHANCE
WILL OCCUR BEHIND THE FRONT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RIDGE ALONG THE COAST WILL BE SHIFTING FARTHER OFFSHORE
THROUGH TONIGHT. AN INCREASE IN MOISTURE SHOULD OCCUR IN A
SOUTHERLY FLOW. THE MODELS INDICATE UPPER SUPPORT WILL OCCUR
THROUGH TONIGHT WITH AN H5 DIFLUENT PATTERN. ENHANCED LIFT MAY
OCCUR THIS MORNING AND TONIGHT AHEAD OF SHORTWAVE TROUGHS.
BELIEVE A LEAD SHORTWAVE TROUGH WAS HELPING SUPPORT THE SCATTERED
SHOWERS IN THE FORECAST AREA EARLY THIS MORNING. THE CONVECTION
ALLOWING MODELS GENERALLY SHOWED SCATTERED SHOWER AND THUNDERSTORM
COVERAGE TODAY AND THIS APPEARS REASONABLE WITH SHORTWAVE TROUGH
TIMING NOT DIURNALLY FAVORABLE. THE GUIDANCE CONSENSUS MOS
SUPPORTED POPS OF 20 TO 30 PERCENT TODAY.
THE THUNDERSTORM CHANCE SHOULD INCREASE TONIGHT AHEAD OF THE NEXT
SHORTWAVE TROUGH. THE HRRR DISPLAYED CONSIDERABLE COVERAGE ABOUT
TO ENTER THE FORECAST AREA FROM THE WEST TOWARD SUNSET. THE SPC
WRF SHOWED THIS AREA DIMINISHING AS IT MOVED THROUGH THE FORECAST
AREA DURING THE 800 PM TO 100 AM TIME FRAME. FORECASTED A POP
AROUND 40 PERCENT CLOSE TO THE GUIDANCE CONSENSUS.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE TODAY.
LEANED TOWARD THE WARMER GUIDANCE BECAUSE OF EXPECTED CLOUDINESS
AND MIXING TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CONVERGENCE INTO A PRE-FRONTAL TROUGH AND COLD FRONT TUESDAY AND
TUESDAY NIGHT PLUS UPPER-LEVEL TROUGHING SHOULD LEAD TO NUMEROUS
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. WE LEANED
TOWARD THE HIGHER POP GUIDANCE. SHOWER AND THUNDERSTORM COVERAGE
MAY BE GREATEST EARLY TUESDAY AHEAD OF A MID-LEVEL SHORTWAVE
TROUGH AND AGAIN TUESDAY EVENING NEAR STRONGER CONVERGENCE JUST
AHEAD OF THE FRONT. THE MODELS INDICATE MODERATE INSTABILITY AND
PRECIPITABLE WATER OVER 2 INCHES. THUNDERSTORMS WITH DAMAGING WIND
AND EXCESSIVE RAIN WILL BE POSSIBLE. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF INDICATE UPPER TROUGHING CONTINUING OVER THE
EASTERN PART OF THE NATION THROUGH THE MEDIUM-RANGE PERIOD. THE
MODELS DISPLAY A FRONTAL SYSTEM LINGERING NEAR THE SOUTHEAST
COAST. DEEP MOISTURE APPEARS TO REMAIN SOUTH AND EAST OF THE
FORECAST AREA. THE GFS AND ECMWF MOS HAVE TEMPERATURES NEAR
CLIMATOLOGY WITH POPS 10 TO 30 PERCENT.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A FEW SHOWERS HAVE DEVELOPED OVER THE WESTERN MIDLANDS AND CSRA
EARLY THIS MORNING. GIVEN LATEST RADAR TRENDS...HAVE INCLUDED A
TEMPO GROUP FOR SHOWERS FOR AGS/DNL UNTIL 12Z. CLOUDS AND A 15 TO 20
KNOT LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL BEFORE SUNRISE. LIGHT
SE WINDS EARLY BECOMING SOUTH TO SOUTHWEST 5 TO 10 KNOTS BY LATE
MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP ACROSS THE
AREA BY EARLY THIS EVENING...BUT GIVEN LOW CONFIDENCE IN TIMING
AND AREAL COVERAGE...HAVE NOT INCLUDED CONVECTION IN THE TAFS ATTM.
EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE
TUESDAY THROUGH TUESDAY NIGHT AS AN APPROACHING FRONTAL BOUNDARY
MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
413 AM EDT MON AUG 10 2015
.SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT WILL IMPACT THE CWFA IN THE SHORT TERM PORTION OF THE
FORECAST AREA. THE FRONT CURRENTLY STRETCHES FROM THE MID
MISSISSIPPI RIVER VALLEY TO THE TENNESSEE VALLEY. THE BOUNDARY WILL
SLIP SLOWLY SOUTH TODAY...AND CROSS MUCH OF THE FORECAST AREA ON
TUESDAY.
DEWPOINTS HAVE BEGUN TO CREEP UP ACROSS THE CWFA...A SIGN OF
INCREASING LOW LEVEL MOISTURE. PRECIPITATION CHANCES WILL INCREASE
TODAY AHEAD OF THE FROPA. HI-RES MODELS ARE SHOWING A RATHER
ORGANIZED LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTH ACROSS
NORTH AND CENTRAL GA THIS AFTERNOON. THE LOCAL WRF AND THE HRRR DO
DIFFER A BIT...WITH THE WRF BEING LATER WITH THE CONVECTION. HAVE
TRIED TO COMPROMISE ON TIMING. BOTH MODELS...HOWEVER...INDICATE VERY
GOOD RAIN CHANCES ACROSS NORTHERN GA TODAY. SO...HAVE RAISED POPS TO
LIKELY IN THAT REGION.
ATMOS WILL BE FAVORABLE FOR STRONG TO ISOLATED SEVERE STORMS. GOOD
SURFACE INSTABILITY WILL BE PRESENT...WITH AN ASSIST BY A SHORTWAVE
DROPPING SOUTH IN THE MID LEVEL FLOW. MODELS CURRENTLY KEEP LAPSE
RATES FAIRLY WEAK...BUT THE SHORTWAVE WILL PROVIDE SOME LIFT.
COPIOUS CLOUD COVER SHOULD HELP LIMIT SEVERE STORM COVERAGE.
THE MAIN FOCUS FOR TODAYS CONVECTION SHOULD BE ANY
OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FROM THE THUNDERSTORM
COMPLEX CURRENTLY ACROSS THE MID MISSISSIPPI RIVER VALLEY. THE
ACTUAL FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR STORMS TOMORROW.
TEMPS SHOULD BE A FEW DEGREES COOLER THAN YESTERDAYS VALUES DUE TO
THE INCREASED CLOUD COVER. TEMP/DEWPOINT VALUES REMAIN BELOW
CRITICAL THRESHOLDS FOR A HEAT ADVISORY AT THIS TIME.
NLISTEMAA
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE IN DECENT AGREEMENT WITH AFOREMENTIONED FRONTAL BOUNDARY
IN THE SHORT TERM LINGERING ACROSS THE SOUTHERN TIER OF THE CWA
FOR TUESDAY NIGHT INTO WEDNESDAY...THEN FINALLY PUSHING JUST SOUTH
OF THE AREA AND BECOMING MORE DIFFUSE THRU THE REST OF THE WORK
WEEK. HAVE TRENDED CHANCE TO SLIGHT POPS ACCORDINGLY AND ADVECTION
OF ABNORMALLY DRY AIR IN FROM THE NW WILL ALLOW FOR A RATHER
PLEASANT WED AND THURS WITH SLIGHTLY BELOW NORMAL HIGHS AND
RESULTANT AFTERNOON RH VALUES IN THE 40S.
FOR FRIDAY INTO THE WEEKEND...A BROAD/WEAK AREA OF LOW PRESSURE
LOOKS TO DEVELOP ACROSS THE NORTHERN GOM ALLOWING FOR SOME LOW
LEVEL MOISTURE TRANSPORT OFF THE ATLANTIC. HAVE CONTINUED TO
ADVERTISE A RETURN OF SLIGHT TO LOW END CHANCE POPS FOR PORTIONS
OF THE AREA...MAINLY FOR DIURNALLY DRIVEN CONVECTION. NO OTHER
CLEAR FORCING MECHANISM LOOKS TO BE PRESENT SO NOT EXPECTING
ANYTHING WIDESPREAD AND RATHER STAGNANT AIRMASS IN PLACE SO
DEVELOPMENT SHOULD BE TYPICAL SUMMERTIME OUTFLOW DRIVEN. TEMPS
SHOULD BE SLIGHTLY WARMER THAN MIDWEEK BUT CLOSE TO NORMAL OR
SLIGHTLY BELOW WITH ENHANCED CLOUD COVERAGE.
BAKER
&&
.AVIATION...
06Z UPDATE...
HIGH RES MODELS ARE BRINGING IN PRECIP A LITTLE EARLIER THAN
PREVIOUS RUNS. HAVE PUSHED BACK THE PROB GROUP A COUPLE OF
HOURS. CIGS AROUND 045 DURING THE AFTERNOON. MODEL SOUNDINGS ARE
ALSO SHOWING SOME POTENTIAL FOR MVFR CIGS OVERNIGHT.
//ATL CONFIDENCE...06Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 72 89 71 / 40 40 30 30
ATLANTA 90 74 88 72 / 40 40 30 20
BLAIRSVILLE 84 67 83 63 / 60 40 30 10
CARTERSVILLE 90 71 88 68 / 60 40 30 20
COLUMBUS 93 76 91 74 / 40 30 40 40
GAINESVILLE 87 72 87 71 / 60 40 30 20
MACON 92 74 90 73 / 40 30 40 40
ROME 91 72 89 68 / 60 40 30 10
PEACHTREE CITY 91 72 89 70 / 40 30 30 30
VIDALIA 92 73 92 74 / 30 20 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BAKER
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS LINCOLN IL
305 AM CDT MON AUG 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VISBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE PAST
HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL DENSE
FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY DENSE
OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
&&
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CDT SUN AUG 9 2015
MAIN FORECAST CONCERN WILL BE CIGS AND VSBYS OVERNIGHT AS FOG
BECOMES MORE WIDESPREAD. OVERALL...LITTLE CHANGE IN THINKING
FROM EARLIER THIS EVENING. WIDELY SCATTERED SHOWERS WERE NOTED
ALONG THE I-74 CORRIDOR WITH ANOTHER AREA OF SHOWERS AND STORMS
SOUTH OF I-70. LATEST SURFACE ANALYSIS AND SURFACE OBSERVATIONS
TO OUR WEST AND NORTHWEST STILL INDICATES SOME CLOUD COVER WHICH
MAY PREVENT THE FOG FROM BECOMING TO WIDESPREAD EARLY MONDAY
MORNING. HOWEVER...WE DO SEE SOME SIZEABLE BREAKS IN THE OVERCAST
AS WELL SO ANY PROLONGED PERIOD OF CLEAR SKIES WILL LEAD TO SOME
LOCALLY DENSE (IFR OR VLIFR CONDITIONS) FOG FOR A TIME EARLY
MONDAY MORNING. THE FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z
MONDAY WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY
LATE MORNING WITH SCATTERED TO BROKEN CUMULUS IN THE AFTERNOON
WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS WILL BE
LIGHT AND VARIABLE TONIGHT AND THEN SWING INTO THE NORTHWEST
TO NORTH MONDAY MORNING AT 10 TO 15 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 AM CDT MON AUG 10 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GRADUAL LOWERING OF CIG/VIS THROUGH MVFR/IFR OVERNIGHT. A FEW
SPOTTY SHOWERS POSSIBLE. IMPROVEMENT FROM IFR/MVFR EXPECTED
DURING MONDAY MORNING.
* NORTHERLY WINDS MONDAY...LIKELY BECOMING NORTHEAST WITH LAKE
BREEZE DURING THE AFTERNOON.
* SCATTERED TSRA MONDAY AFTERNOON.
KMD
//DISCUSSION...UPDATED 06Z...
A FEW LOW TOPPED SHOWERS IN COOK COUNTY AND OVER THE LAKE IN MOIST
SW FLOW ATOP A LINGERING ELEVATED FRONT. CARRYING A VCSH FOR THESE
FOR THE NEXT FEW HOURS BUT SHOULD BE LOW IMPACT.
OVERNIGHT CONCERN FOCUSES ON CEILING AND VISIBILITY.
DETERIORATION OF CONDITIONS HAD BEEN SLOW GOING BUT THE DOWNWARD
TREND IS PICKING UP QUICKLY...ESPECIALLY IN OUTLYING AREAS WHERE
SOME CLEARING SKIES HAVE ALLOWED CIGS AND VIS TO DROP INTO IFR AND
EVEN LIFR. EXPECT THIS TREND TO CONTINUE AT LEAST FOR THE NEXT 4-6
HOURS BEFORE HIGHER CLOUDS BEGIN TO SPREAD OVERHEAD. MVFR
CONDITIONS ARE ALSO MOVING INTO THE CHICAGOLAND TERMINALS.
SLIGHTLY HIGHER DEWPOINT DEPRESSIONS MAY PRECLUDE IFR FROM GETTING
TO ORD/MDW BUT WILL BE A CLOSE CALL.
CONCERN SHIFTS TO SEVERAL ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. TIMING OF THE SHORTWAVE OVER MINNESOTA BRINGS
ACTIVITY THROUGH RFD BY 17Z AND THROUGH THE CHICAGO TERMINALS
AROUND 18-20Z. HAVE CARRIED A VCTS FOR THIS TIME FRAME AS THERE
SHOULD BE CAPE AROUND DUE TO THE MOIST AIR MASS AND INCREASED
LAPSE RATES AHEAD OF THIS WAVE. FAVORABLE TIMING OF THE WAVE
THOUGH SLIGHTLY EARLY...BUT SHOULD ALSO BE A CONVERGENT AXIS AS
THE LAKE BREEZE BEGINS TO SETUP AS WELL. CARRIED A VCSH AFTER DUE
TO THE FORCING POSSIBLY BEING THROUGH THE TERMINALS AND SLIGHTLY
SHALLOWER MOISTURE AVAILABILITY. COVERAGE LOOKS TO BE SCATTERED AT
THIS POINT.
LASTLY...WINDS WILL SHIFT TO NORTHERLY MONDAY MORNING...THEN GAIN
AN ONSHORE COMPONENT THROUGH THE MORNING/EARLY AFTERNOON AS THE
LAKE INFLUENCE KICKS IN. AT THIS POINT MOST HI-RES GUIDANCE KEEPS
WINDS UNDER 10 KT...THOUGH EXPECT A FEW GUSTS AT THE SENSORS TO
GET CLOSE TO THAT THRESHOLD.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
* MEDIUM IN CIG/VIS TRENDS TONIGHT/EARLY MONDAY.
* MEDIUM-LOW IN MONDAY AFTERNOON TSRA.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
RATZER
&&
.MARINE...
251 AM CDT
LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY THIS EVENING. THIS WILL ENABLE A TRAILING SURFACE TROUGH TO PASS
OVER THE LAKE THIS MORNING AND SHIFT WINDS NORTHERLY. SEVERAL WEAK
LOWS ALONG THE TROUGH AXIS WILL CONSOLIDATE INTO A SLIGHTLY DEEPER
LOW OVER THE EASTERN GREAT LAKES. HIGH PRESSURE OVER THE NORTHERN
PLAINS WILL SHIFT INTO UPPER MIDWEST TOMORROW. IN BETWEEN THESE TWO
FEATURES...NORTHERLY WINDS WILL INCREASE TO 15-25 KTS BY TUESDAY
MORNING. AS THE HIGH MOVES EAST...THESE NORTHERLY WINDS WILL SLOWLY
DIMINISH TUESDAY NIGHT INTO WEDNESDAY. WINDS WILL SHIFT TO THE
SOUTHWEST WEDNESDAY NIGHT AS THE HIGH SETTLES SOUTHEAST OF THE LAKE
AND LOW PRESSURE APPROACHES HUDSON BAY. SPEEDS LOOK TO INCREASE INTO
THE 15-25KT RANGE THURSDAY INTO THURSDAY NIGHT. HIGH PRESSURE WILL
SHIFT WINDS BACK NORTHERLY TOWARD THE WEEKEND.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
123 AM CDT MON AUG 10 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GRADUAL LOWERING OF CIG/VIS THROUGH MVFR/IFR OVERNIGHT. A FEW
SPOTTY SHOWERS POSSIBLE. IMPROVEMENT FROM IFR/MVFR EXPECTED
DURING MONDAY MORNING.
* NORTHERLY WINDS MONDAY...LIKELY BECOMING NORTHEAST WITH LAKE
BREEZE DURING THE AFTERNOON.
* SCATTERED TSRA MONDAY AFTERNOON.
KMD
//DISCUSSION...UPDATED 06Z...
A FEW LOW TOPPED SHOWERS IN COOK COUNTY AND OVER THE LAKE IN MOIST
SW FLOW ATOP A LINGERING ELEVATED FRONT. CARRYING A VCSH FOR THESE
FOR THE NEXT FEW HOURS BUT SHOULD BE LOW IMPACT.
OVERNIGHT CONCERN FOCUSES ON CEILING AND VISIBILITY.
DETERIORATION OF CONDITIONS HAD BEEN SLOW GOING BUT THE DOWNWARD
TREND IS PICKING UP QUICKLY...ESPECIALLY IN OUTLYING AREAS WHERE
SOME CLEARING SKIES HAVE ALLOWED CIGS AND VIS TO DROP INTO IFR AND
EVEN LIFR. EXPECT THIS TREND TO CONTINUE AT LEAST FOR THE NEXT 4-6
HOURS BEFORE HIGHER CLOUDS BEGIN TO SPREAD OVERHEAD. MVFR
CONDITIONS ARE ALSO MOVING INTO THE CHICAGOLAND TERMINALS.
SLIGHTLY HIGHER DEWPOINT DEPRESSIONS MAY PRECLUDE IFR FROM GETTING
TO ORD/MDW BUT WILL BE A CLOSE CALL.
CONCERN SHIFTS TO SEVERAL ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. TIMING OF THE SHORTWAVE OVER MINNESOTA BRINGS
ACTIVITY THROUGH RFD BY 17Z AND THROUGH THE CHICAGO TERMINALS
AROUND 18-20Z. HAVE CARRIED A VCTS FOR THIS TIME FRAME AS THERE
SHOULD BE CAPE AROUND DUE TO THE MOIST AIR MASS AND INCREASED
LAPSE RATES AHEAD OF THIS WAVE. FAVORABLE TIMING OF THE WAVE
THOUGH SLIGHTLY EARLY...BUT SHOULD ALSO BE A CONVERGENT AXIS AS
THE LAKE BREEZE BEGINS TO SETUP AS WELL. CARRIED A VCSH AFTER DUE
TO THE FORCING POSSIBLY BEING THROUGH THE TERMINALS AND SLIGHTLY
SHALLOWER MOISTURE AVAILABILITY. COVERAGE LOOKS TO BE SCATTERED AT
THIS POINT.
LASTLY...WINDS WILL SHIFT TO NORTHERLY MONDAY MORNING...THEN GAIN
AN ONSHORE COMPONENT THROUGH THE MORNING/EARLY AFTERNOON AS THE
LAKE INFLUENCE KICKS IN. AT THIS POINT MOST HI-RES GUIDANCE KEEPS
WINDS UNDER 10 KT...THOUGH EXPECT A FEW GUSTS AT THE SENSORS TO
GET CLOSE TO THAT THRESHOLD.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
* MEDIUM IN CIG/VIS TRENDS TONIGHT/EARLY MONDAY.
* MEDIUM-LOW IN MONDAY AFTERNOON TSRA.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
RATZER
&&
.MARINE...
251 PM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY MONDAY EVENING. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE
LATE TONIGHT INTO MONDAY MORNING SHIFTING WINDS NORTHERLY. ANOTHER
WEAK LOW WILL MOVE SOUTH OF THE LAKE MONDAY AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE GRADIENT WILL
TIGHTEN BETWEEN THESE TWO FEATURES WITH NORTHERLY WINDS INCREASING
TO 15-25 KTS BY TUESDAY MORNING. AS THE HIGH MOVES EAST...THESE
NORTHERLY WINDS WILL SLOWLY DIMINISH TUESDAY NIGHT INTO WEDNESDAY.
WINDS WILL SHIFT TO THE SOUTHWEST WEDNESDAY NIGHT AS THE HIGH
SETTLES SOUTHEAST OF THE LAKE AND DEPENDING ON HOW STRONG THE
GRADIENT BECOMES...SPEEDS MAY INCREASE INTO THE 15-25KT RANGE
THURSDAY INTO THURSDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1101 PM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 825 PM CDT SUN AUG 9 2015
THE BOUNDARY THAT WAS PRODUCED BY THE STORMS THIS MORNING WAS
LOCATED OVER SOUTHEAST ILLINOIS BACK INTO EAST CENTRAL MISSOURI.
A CLUSTER OF STORMS WAS TRACKING ESE ALONG THIS MESOSCALE FEATURE
AND MAY CLIP OUR FAR SOUTHEAST COUNTIES. MEANWHILE...FURTHER TO
THE NORTHWEST...A WEAK COOL FRONT WAS LOCATED FROM CENTRAL
WISCONSIN SOUTHWEST THROUGH NORTHERN IOWA WITH A BAND OF STORMS
OVER PARTS OF NORTHWEST IOWA. THE ACTUAL SYNOPTIC SCALE COOL
FRONT TO OUR NORTHWEST IS FORECAST TO PUSH ACROSS THE FORECAST
AREA MONDAY MORNING. UNTIL THEN...WILL CONTINUE WITH THE CHANCES
FOR SHOWERS AND STORMS...ESPECIALLY ACROSS THE SOUTH OVERNIGHT
WITH LOWER POPS AS YOU HEAD NORTH OF I-74. WITH THE ADDED MOISTURE
FROM THE RAINFALL TODAY...LIGHT WINDS AND A GRADUAL TREND TOWARDS
CLEARING SKIES LATE TONIGHT...FOG WILL BE A CONCERN AND WILL
CONTINUE TO HOLD WITH THAT IN THE FORECAST THRU MONDAY MORNING.
HAVE MADE SOME MINOR ADJUSTMENTS TO THE RAIN CHANCES...ESPECIALLY
ACROSS THE NORTH AND MADE SOME TWEAKS TO THE SKY COVER FOR THE
LATE NIGHT HOURS. WE SHOULD HAVE THE UPDATE OUT BY 845 PM.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 253 PM CDT SUN AUG 9 2015
BASED ON SURFACE DATA...APPEARS THERE IS A BOUNDARY STRETCHING FROM
NORTHERN MO/SOUTHERN IA INTO NORTHERN PART OF CENTRAL IL.
HOWEVER...THE EFFECTIVE BOUNDARY SHOULD BE MUCH FURTHER SOUTH AS A
RESULT OF THE MCS THAT MOVED ACROSS THE AREA EARLIER THIS MORNING
PUSHING IT SOUTH OF THE CWA. HRRR DOES NOT SHOW ANY PCPN IN THE CWA
TONIGHT...BUT DOES HAVE THE SMALL AREA OF PCPN IN NORTHERN MO MOVING
EAST-SOUTHEAST INTO SOUTHERN IL THIS EVENING. BUT WITH A WEAK
CONVERGENT BOUNDARY IN THE AREA AM INCLINED TO KEEP A CHANCE FOR
POPS IN THE FORECAST FOR TONIGHT. TREND SHOULD BE...AND MODELS DO
SUPPORT THAT THIS WEAK BOUNDARY SHOULD MOVE SOUTH DURING THE
OVERNIGHT PERIOD. SO CHANCE POPS SOUTHEAST OF THE ILLINOIS RIVER
TONIGHT. ENDING OF PCPN CHANCES WILL START ALONG THE RIVER AND THEN
PROGRESS SOUTHEAST THROUGH THE PERIOD. OTHER ISSUE OVERNIGHT WILL BE
FOG DEVELOPMENT. WITH LOTS OF BREAKS IN THE CLOUDS THIS EVENING AND
OVERNIGHT...COMBINED WITH THE ABUNDANCE OF LOW LEVEL MOISTURE FROM
THE RAIN THIS MORNING...AND LIGHT WINDS...BELIEVE FOG WILL DEVELOP
THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. SO HAVE INCLUDED
AREAS OF FOG IN THE FORECAST THE NORTHERN AND CENTRAL PARTS OF THE
AREA. ONLY PLACE WITHOUT ANY FOG WILL BE AREAS SOUTHEAST OF I-70.
OVERNIGHT LOWS AROUND 70S LOOKS REASONABLE WITH COOLEST TEMPS UP
NORTH WHERE MORE BREAKS IN CLOUDS SHOULD BE.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN AUG 9 2015
A FRONTAL BOUNDARY CURRENTLY FROM NORTHERN WISCONSIN TO NORTHERN
NEBRASKA WILL PUSH INTO SOUTHEAST ILLINOIS BY MID MORNING
MONDAY...AIDED BY SEVERAL AREAS OF THUNDERSTORM DEVELOPMENT AHEAD OF
THE FRONT THIS EVENING INTO TONIGHT. THE EFFECTIVE FRONT WILL LIKELY
BE LINGERING IN SOUTHEAST PORTIONS OF THE CENTRAL IL FORECAST AREA
THROUGH THE MORNING AND HAVE CONTINUED PRECIPITATION CHANCES IN THAT
AREA THROUGH NOON. MOST OF THE THUNDERSTORM ACTIVITY WILL TEND TO
MOVE EASTWARD THROUGH THE DAY...HOWEVER AN UPPER LEVEL SHORTWAVE
WILL APPROACH FROM THE NORTHWEST BY AFTERNOON...AND LIFT ASSOCIATED
WITH THIS FEATURE WILL CAUSE CHANCES FOR SHOWERS AND THUNDERSTORMS
TO RE-DEVELOP FOR AFTERNOON AND EARLY EVENING...MAINLY FROM THE
ILLINOIS RIVER NORTHWESTWARD. HIGHS EXPECTED TO REACH FROM AROUND 81
IN GALESBURG TO THE MID 80S SPRINGFIELD TO PARIS SOUTHWARD WITH
WINDS BECOMING NORTHWEST UP TO 10 MPH.
AFTER THIS FEATURE PASSES THROUGH...DRY CONDITIONS ARE EXPECTED
THROUGH MUCH OF THE WEEK AS A PRONOUNCED UPPER LEVEL RIDGE BUILDS
OVER THE CENTRAL U.S. AND TROUGHING OVER THE NORTHEASTERN U.S. A
COOL NORTHWEST FLOW PATTERN BETWEEN THE RIDGE AND TROUGH WILL BRING
HIGH TEMPERATURES PRIMARILY IN THE LOW 80S AND LOWS IN THE LOW 60S
THROUGH THURSDAY. A COLD FRONT EMBEDDED IN THIS FLOW PATTERN WILL
DROP INTO THE GREAT LAKES/MIDWEST AREA FRIDAY. MODELS CONTINUE SOME
RUN TO RUN INCONSISTENCIES FOR THIS FEATURE...BUT BULK OF GUIDANCE
CONTINUES TO SUGGEST PRECIPITATION ASSOCIATED WITH THIS FEATURE MAY
STRUGGLE TO REACH AS FAR SOUTHWEST AS CENTRAL ILLINOIS.
THEREFORE...HAVE INCORPORATED SLIGHT CHANCES FOR THUNDERSTORMS
MAINLY I-72 NORTHWARD. DRY CONDITIONS SHOULD THEN RETURN THROUGH THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CDT SUN AUG 9 2015
MAIN FORECAST CONCERN WILL BE CIGS AND VSBYS OVERNIGHT AS FOG
BECOMES MORE WIDESPREAD. OVERALL...LITTLE CHANGE IN THINKING
FROM EARLIER THIS EVENING. WIDELY SCATTERED SHOWERS WERE NOTED
ALONG THE I-74 CORRIDOR WITH ANOTHER AREA OF SHOWERS AND STORMS
SOUTH OF I-70. LATEST SURFACE ANALYSIS AND SURFACE OBSERVATIONS
TO OUR WEST AND NORTHWEST STILL INDICATES SOME CLOUD COVER WHICH
MAY PREVENT THE FOG FROM BECOMING TO WIDESPREAD EARLY MONDAY
MORNING. HOWEVER...WE DO SEE SOME SIZEABLE BREAKS IN THE OVERCAST
AS WELL SO ANY PROLONGED PERIOD OF CLEAR SKIES WILL LEAD TO SOME
LOCALLY DENSE (IFR OR VLIFR CONDITIONS) FOG FOR A TIME EARLY
MONDAY MORNING. THE FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z
MONDAY WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY
LATE MORNING WITH SCATTERED TO BROKEN CUMULUS IN THE AFTERNOON
WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS WILL BE
LIGHT AND VARIABLE TONIGHT AND THEN SWING INTO THE NORTHWEST
TO NORTH MONDAY MORNING AT 10 TO 15 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...AUTEN
LONG TERM...ONTON
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
555 AM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 350 AM EDT MON AUG 10 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A LOW
PRESSURE SYSTEM MOVES ACROSS THE REGION. A FEW OF THESE STORMS MAY
PRODUCE HEAVY RAIN AND GUSTY WINDS ALONG AND EAST OF INTERSTATE 69
THIS AFTERNOON. HIGH PRESSURE AND DRY CONDITIONS RETURN OVERNIGHT
AND PERSIST UNTIL THE END OF THE WEEK. ONE LAST MUGGY DAY TODAY
WITH HIGHS AROUND 80 DEGREES BUT LESS HUMID AND SLIGHTLY COOLER
CONDITIONS EXPECTED FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT MON AUG 10 2015
ANOTHER "GRUNGY" DAY IN STORE FOR THE LOCAL FORECAST AREA AS BROAD
MID/UPPER LEVEL HEIGHT FALLS INDUCE MODEST SURFACE CYCLOGENESIS OVER
THE GREAT LAKES WITH A VERY MOIST/MARGINALLY UNSTABLE ENVIRONMENT IN
PLACE. THIS SETUP WILL LIKELY LEAD TO SEVERAL ROUNDS OF SPORADIC
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. ALREADY A FEW ISOLATED
SHOWERS POPPING UP ACROSS THE REGION AND SHOULD SEE THIS ACTIVITY
GRADUALLY EXPAND DURING THE DAY AS DIFFUSE SURFACE BOUNDARY
CURRENTLY OVER IOWA PUSHES EASTWARD AND CAPITALIZES ON SOME DEGREE
OF DIURNAL HEATING. LAST FEW RUNS OF HRRR (AND TO A LESSER EXTENT
THE RAP) FINALLY SEEM TO HAVE A LITTLE BETTER HANDLE ON THE CURRENT
PICTURE AND SUGGEST PRECIP WILL EXPAND IN OUR NORTHWEST COUNTIES
DURING THE LATE MORNING (~14Z) AND PUSH SOUTHEASTWARD THROUGH THE
DAY. THIS SEEMS REASONABLE BASED ON LATEST RADAR MOSAIC/SURFACE OBS
AND BACKGROUND SYNOPTIC PATTERN. HAVE THEREFORE MASSAGED POP GRIDS A
BIT TO REFLECT THIS EXPECTED EVOLUTION. MIDLEVEL LAPSE RATES DO GET
A LITTLE BETTER WITH APPROACHING TROUGH AND AMPLE LOW LEVEL MOISTURE
WILL SUPPORT AROUND 1500 J/KG OF SBCAPE IN OUR EASTERN HALF THIS
AFTERNOON DESPITE ABUNDANT CLOUD COVER. THIS SHOULD BE ENOUGH FOR
DECENT COVERAGE OF THUNDERSTORMS BUT POTENTIAL FOR STRONG UPDRAFTS
AND SEVERE WEATHER APPEARS LOW. PASSING MIDLEVEL SPEED MAX DOES
YIELD GOOD DEEP LAYER SHEAR NUMBERS BUT WIND PROFILES IN THE 0-3KM
LAYER ARE FAIRLY LIGHT AND...GIVEN LESS THAN STELLAR INSTABILITY
VALUES...SUGGEST A LOW SEVERE RISK. MAIN THREAT WOULD BE AN ISOLATED
STRONG/SEVERE DOWNBURST WHERE ANY POCKETS OF ENHANCED CAPE MANAGE TO
DEVELOP. POCKETS OF HEAVY RAIN ALSO POSSIBLE GIVEN PW VALUES AROUND
1.75 INCHES BUT RECENT DRY SPELL AND OVERALL LACKLUSTER SYNOPTIC
FORCING SUGGEST THREAT FOR WIDESPREAD FLOODING IS LOW. PRECIP
SHOULD EXIT THE CWA BY THIS EVENING WITH COOLER AND MUCH DRIER AIR
FILTERING SOUTH. AFTER A MUGGY DAY TODAY WITH HIGHS AROUND
80F...EXPECT DEWPOINTS AND LOW TEMPS TO DROP BACK INTO THE LOWER
60S OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 350 AM EDT MON AUG 10 2015
HIGH PRESSURE OVER THE UPR MIDWEST TUE WILL MOVE SE TO INDIANA
WED PROVIDING FAIR WEATHER ACROSS OUR AREA. NW FLOW ALOFT WILL
ADVECT A COOL CANADIAN AIRMASS S-SE INTO OUR AREA RESULTING IN BLO
NORMAL TEMPS THROUGH THIS TIMEFRAME. DRY WX SHOULD CONT THU AS THE
HIGH MOVES SE OF THE AREA WITH WAA ON THE BACKSIDE OF THE HIGH
RESULTING IN A LITTLE WARMER TEMPS.
A CDFNT IS EXPECTED TO DROP SLOWLY S-SE ACROSS THE GRTLKS THU NGT-
FRI NGT. UPR RIDGE AXIS OVER THE ROCKIES IS ALSO EXPECTED TO MOVE
EAST IN THIS TIMEFRAME SO A GENERAL WKNG TREND OF THE FRONT IS
EXPECTED... BUT MEDIUM RANGE MODELS IN DECENT AGREEMENT SUGGESTING
AT LEAST SOME CONVECTION MAY FORM ALONG/AHEAD OF THE FRONT SO HAVE
ADDED LOW POPS FOR LATE IN THE WORKWEEK. BY THE WEEKEND THE UPR
RIDGE AXIS SHOULD MOVE OVER OUR AREA PROVIDING DRY WX WITH ABOVE
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 555 AM EDT MON AUG 10 2015
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE IN COVERAGE
TODAY AS A MIDLEVEL TROUGH APPROACHES THE REGION AND INTERSECTS A
VERY MOIST AIRMASS. ISOLATED THUNDERSTORMS POSSIBLE THIS MORNING
BUT BETTER CHANCES STILL LOOK TO BE AT KFWA THIS AFTERNOON.
PERIODS OF MVFR CONDITIONS POSSIBLE AS WEAK FRONTAL BOUNDARY
APPROACHES THE AREA BUT LATEST HI-RES/RAPID UPDATE GUIDANCE
SUGGESTS CEILINGS WILL LIKELY REMAIN ABOVE FUEL ALTERNATE
CRITERIA. CONDITIONS WILL IMPROVE BY THIS EVENING AS FRONT EXITS
AND DRIER AIR FILTERS SOUTH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
350 AM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 350 AM EDT MON AUG 10 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A LOW
PRESSURE SYSTEM MOVES ACROSS THE REGION. A FEW OF THESE STORMS MAY
PRODUCE HEAVY RAIN AND GUSTY WINDS ALONG AND EAST OF INTERSTATE 69
THIS AFTERNOON. HIGH PRESSURE AND DRY CONDITIONS RETURN OVERNIGHT
AND PERSIST UNTIL THE END OF THE WEEK. ONE LAST MUGGY DAY TODAY
WITH HIGHS AROUND 80 DEGREES BUT LESS HUMID AND SLIGHTLY COOLER
CONDITIONS EXPECTED FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT MON AUG 10 2015
ANOTHER "GRUNGY" DAY IN STORE FOR THE LOCAL FORECAST AREA AS BROAD
MID/UPPER LEVEL HEIGHT FALLS INDUCE MODEST SURFACE CYCLOGENESIS OVER
THE GREAT LAKES WITH A VERY MOIST/MARGINALLY UNSTABLE ENVIRONMENT IN
PLACE. THIS SETUP WILL LIKELY LEAD TO SEVERAL ROUNDS OF SPORADIC
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. ALREADY A FEW ISOLATED
SHOWERS POPPING UP ACROSS THE REGION AND SHOULD SEE THIS ACTIVITY
GRADUALLY EXPAND DURING THE DAY AS DIFFUSE SURFACE BOUNDARY
CURRENTLY OVER IOWA PUSHES EASTWARD AND CAPITALIZES ON SOME DEGREE
OF DIURNAL HEATING. LAST FEW RUNS OF HRRR (AND TO A LESSER EXTENT
THE RAP) FINALLY SEEM TO HAVE A LITTLE BETTER HANDLE ON THE CURRENT
PICTURE AND SUGGEST PRECIP WILL EXPAND IN OUR NORTHWEST COUNTIES
DURING THE LATE MORNING (~14Z) AND PUSH SOUTHEASTWARD THROUGH THE
DAY. THIS SEEMS REASONABLE BASED ON LATEST RADAR MOSAIC/SURFACE OBS
AND BACKGROUND SYNOPTIC PATTERN. HAVE THEREFORE MASSAGED POP GRIDS A
BIT TO REFLECT THIS EXPECTED EVOLUTION. MIDLEVEL LAPSE RATES DO GET
A LITTLE BETTER WITH APPROACHING TROUGH AND AMPLE LOW LEVEL MOISTURE
WILL SUPPORT AROUND 1500 J/KG OF SBCAPE IN OUR EASTERN HALF THIS
AFTERNOON DESPITE ABUNDANT CLOUD COVER. THIS SHOULD BE ENOUGH FOR
DECENT COVERAGE OF THUNDERSTORMS BUT POTENTIAL FOR STRONG UPDRAFTS
AND SEVERE WEATHER APPEARS LOW. PASSING MIDLEVEL SPEED MAX DOES
YIELD GOOD DEEP LAYER SHEAR NUMBERS BUT WIND PROFILES IN THE 0-3KM
LAYER ARE FAIRLY LIGHT AND...GIVEN LESS THAN STELLAR INSTABILITY
VALUES...SUGGEST A LOW SEVERE RISK. MAIN THREAT WOULD BE AN ISOLATED
STRONG/SEVERE DOWNBURST WHERE ANY POCKETS OF ENHANCED CAPE MANAGE TO
DEVELOP. POCKETS OF HEAVY RAIN ALSO POSSIBLE GIVEN PW VALUES AROUND
1.75 INCHES BUT RECENT DRY SPELL AND OVERALL LACKLUSTER SYNOPTIC
FORCING SUGGEST THREAT FOR WIDESPREAD FLOODING IS LOW. PRECIP
SHOULD EXIT THE CWA BY THIS EVENING WITH COOLER AND MUCH DRIER AIR
FILTERING SOUTH. AFTER A MUGGY DAY TODAY WITH HIGHS AROUND
80F...EXPECT DEWPOINTS AND LOW TEMPS TO DROP BACK INTO THE LOWER
60S OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 350 AM EDT MON AUG 10 2015
HIGH PRESSURE OVER THE UPR MIDWEST TUE WILL MOVE SE TO INDIANA
WED PROVIDING FAIR WEATHER ACROSS OUR AREA. NW FLOW ALOFT WILL
ADVECT A COOL CANADIAN AIRMASS S-SE INTO OUR AREA RESULTING IN BLO
NORMAL TEMPS THROUGH THIS TIMEFRAME. DRY WX SHOULD CONT THU AS THE
HIGH MOVES SE OF THE AREA WITH WAA ON THE BACKSIDE OF THE HIGH
RESULTING IN A LITTLE WARMER TEMPS.
A CDFNT IS EXPECTED TO DROP SLOWLY S-SE ACROSS THE GRTLKS THU NGT-
FRI NGT. UPR RIDGE AXIS OVER THE ROCKIES IS ALSO EXPECTED TO MOVE
EAST IN THIS TIMEFRAME SO A GENERAL WKNG TREND OF THE FRONT IS
EXPECTED... BUT MEDIUM RANGE MODELS IN DECENT AGREEMENT SUGGESTING
AT LEAST SOME CONVECTION MAY FORM ALONG/AHEAD OF THE FRONT SO HAVE
ADDED LOW POPS FOR LATE IN THE WORKWEEK. BY THE WEEKEND THE UPR
RIDGE AXIS SHOULD MOVE OVER OUR AREA PROVIDING DRY WX WITH ABOVE
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 136 AM EDT MON AUG 10 2015
AVIATION CONDITIONS STILL EXPECTED TO GRADUALLY DETERIORATE
THROUGH THE MORNING AS BROAD TROUGH APPROACHES THE GREAT LAKES AND
INTERACTS WITH VERY MOIST ENVIRONMENT. LIGHT WINDS AND HIGH
SURFACE DEWPOINTS SUGGEST SOME PATCHY FOG AND LOW STRATUS POSSIBLE
LATER THIS MORNING. LEFT FORECAST CATEGORIES LARGELY IN PLACE DUE
TO LOWER CONFIDENCE...JUST ADJUSTED TIMING. ALSO ADDED A -SHRA
MENTION GIVEN MOST HI-RES GUIDANCE SHOW PRECIP BLOSSOMING AROUND
KSBN LATER THIS MORNING. CHANCE FOR A FEW THUNDERSTORMS AT KFWA
THIS AFTERNOON GIVEN SOME MARGINAL DIURNAL DESTABILIZATION BUT
EXACT TIMING AND COVERAGE REMAIN UNCERTAIN. CONDITIONS SHOULD
IMPROVE BY THE END OF THE TAF PERIOD AS FRONT EXITS AND DRIER AIR
FILTERS SOUTH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1137 PM MDT SUN AUG 9 2015
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 132 PM MDT SUN AUG 9 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE CONTINUING
TO DOMINATE PATTERN ACROSS SOUTHERN P.LAINS WITH WESTERLY FLOW
ACROSS THE NORTHERN PLAINS. H7 SHORTWAVE TROUGH HAS WEAKENED AND
SHIFTED EAST...WITH ANOTHER H7 SHORTWAVE TROUGH OVER NORTHCENTRAL
COLORADO. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER OUR
CWA...WITH A STATIONARY FRONT EXTENDING FROM NORTHEAST COLORADO
ACROSS NORTHCENTRAL NEBRASKA.
THIS AFTERNOON-TONIGHT...AS FIRST H7 TROUGH HAS WEAKENED AND SHIFTED
EAST SUBSIDENCE HAS SPREAD INTO THE WESTERN PART OF THE FORECAST
AREA WITH LOWER TD VALUES (UPPER 40S/LOWER 50S) ADVECTING INTO THE
WESTERN PARTS OF THE FORECAST AREA. RESULT HAS BEEN CAPE VALUES
DROPPING OFF SHARPLY AND SABLE AIR MOVING BACK OVER THE CWA. SHORT
RANGE GUIDANCE CONTINUES TO KEEP HIGHER TD/CAPE VALUES IN OUR
EASTERN CWA WITH ONLY 100-500 J/KG IN THE WEST THROUGH THE EVENING.
CAPE VALUES AROUND 2000 J/KG ACROSS OUR EASTERN CWA COULD SUPPORT A
FEW MARGINALLY SEVERE THUNDERSTORMS IF SOMETHING WAS TO DEVELOP
ALONG WHAT IS LIKELY A DEVELOPING DRY LINE. NOT A LOT OF CONFIDENCE
AND HI RES GUIDANCE HAS TRENDED AWAY FROM ADDITIONAL DEVELOPMENT IN
OUR EAST. IT APPEARS THAT CHANCES ARE DECREASING FOR MOST OF THE CWA
THIS AFTERNOON. THERE IS THE POSSIBILITY FOR A SHOWER OR
THUNDERSTORM IN THE WESTERN CWA AS ANOTHER SHORTWAVE MOVES IN FROM
THE WEST LATE THIS AFTERNOON THROUGH THIS EVENING...WITH BEST
PRECIP SIGNAL IN THE SW. NOT A LOT OF CONFIDENCE AT THIS POINT IN
COVERAGE...SO I DECIDED TO LIMIT POPS TO THE WEST THIS EVENING
WITH A DOWNWARD TREND THROUGH 06Z.
IT DOES APPEAR THAT HIGHER TD VALUES WILL BEGIN TO RECOVER OVERNIGHT
FROM THE EAST/NORTHEAST WITH SURFACE HIGH PRESSURE/LOW LEVEL
STABILITY SUPPORTING POSSIBLE FOG/STRATUS DEVELOPMENT. BASED ON
SHORT RANGE GUIDANCE AND PERSISTENCE I KEPT HIGHER FOG COVERAGE
(AREAS) LIMITED TO REPUBLICAN RIVER VALLEY IN SW NEBRASKA.
MONDAY...GUIDANCE CONTINUES TO SHOW PRECIP SIGNAL LINGERING ACROSS
THE SW PART OF OUR CWA. ANY SHORTWAVE TROUGHS/VORT MAXES ROTATING
THROUGH PERIPHERY OF THE RIDGE APPEAR TO REMAIN SW OF OUR CWA WITH
VERY LIMITED FORCING. INSTABILITY DOES BEGIN TO INCREASE SO IF
ACTIVITY WAS TO DEVELOP TO THE WEST WE COULD SEE DEVELOPMENT TOWARDS
THE SW PART OF OUR FORECAST AREA. I WASNT CONFIDENT ENOUGH TO
INCREASE POPS DESPITE OVERLAPPING QPF FIELDS IN GUIDANCE...SO I
LIMITED POPS TO 20/30 RANGE MONDAY AFTERNOON. HIGH TEMPS AS WITH THE
LAST FEW DAYS WILL BE HIGHLY DEPENDENT ON MORNING STRATUS CLEARING
WHICH IS CURRENTLY EXPECTED. RESULT SHOULD BE SEASONAL HIGHS IN THE
UPPER 80S/AROUND 90.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM MDT SUN AUG 9 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. SOUTHERN UNITED STATES RIDGE REMAINS CENTERED
OVER CENTRAL/EASTERN TEXAS.
MODELS STARTED OUT FINE AT JET LEVEL. AT MID LEVELS...THE
GFS/CANADIAN WERE INITIALLY DOING BETTER THAN THE REST OF THE OUT
WITH THE NAM/SREF THE WORST OF THE REST OF THE BUNCH. THE SREF
LOOKED LIKE IT WAS THE BEST AT THE SURFACE. IT LOOKED LIKE THE
GFS...CANADIAN AND ECMWF WERE DOING THE BEST ON THE LOW LEVEL
THERMAL FIELD AT THIS TIME.
MONDAY NIGHT...LOW LEVEL UPSLOPE WINDS WILL BE IN PLACE THROUGH THE
NIGHT AS SURFACE RIDGE NOSES DOWN INTO THE AREA. AS SHOWN THE LAST
TWO DAYS...THE SHORTWAVE RIDGE AT 700 MB WILL SLOWLY MOVE TOWARD THE
EAST THROUGH THE NIGHT AS A SHORTWAVE MOVES IN FROM THE WEST. MODELS
HAVE SLOWED THINGS UP A LITTLE...AS HAS THE TREND BEEN THE LAST FEW
DAYS AS WELL. THE GFS IS THE FURTHEST EAST WHICH IS NOT AN UCOMMON
THING WHEN IT COMES TO BREAKING DOWN RIDGES TOO FAST.
SO ONLY PROGRESSED THE POPS SLOWLY TO THE EAST THROUGH THE NIGHT.
THE COMBINATION OF SLOW STORM MOVEMENT...PWS OF 1 TO 1.5 INCHES AND
THE COMMON HEAVY RAIN SCENARIO OF A SHORTWAVE MOVING UP THE WEST
SIDE OF A RIDGE COULD PRODUCE SOME LOCALIZED HEAVY RAINFALL. RAMPED
THE AMOUNTS UP A LITTLE AND INCREASED THE INTENSITY OF THE RAINFALL
AS WELL. THE BEST CHANCE FOR RAINFALL WILL BE IN THE SOUTHWEST THIRD
TO HALF OF THE AREA. THIS PERIOD WILL NEED TO BE WASHED CLOSELY.
TUESDAY/TUESDAY NIGHT...SLOWLY EVOLVING SITUATION THAT BEGINS MONDAY
NIGHT...SLOWLY MOVING CONVECTIVELY INDUCED SYSTEM...CONTINUE THROUGH
THIS ENTIRE PERIOD. MODELS ARE IN GOOD AGREEMENT ABOUT THIS. MORE
THAN LIKELY SOME DEGREE OF CONVECTION WILL CONTINUE FROM THIS
PREVIOUS THROUGH THIS ENTIRE PERIOD. AGAIN SAME HEAVY RAIN SCENARIO
IS IN PLACE AS IN THE PREVIOUS PERIOD AND WILL HAVE TO BE WATCHED
CLOSELY. ALSO THE SOUTHWEST THIRD TO HALF WILL HAVE THE BEST CHANCE
OF RAINFALL...ESPECIALLY DURING THE DAY. THE AREA OF RAINFALL WILL
SLOWLY MOVE TO THE SOUTH AND EAST DURING THE NIGHT.
COMBINATION OF UPSLOPE SURFACE WINDS...LOTS OF CLOUD COVER AND
ONGOING PRECIPITATION...WILL KEEP TEMPERATURES FROM WARMING UP TOO
MUCH...ESPECIALLY IN THE SOUTHWEST HALF. SO LOWERED TEMPERATURES
AROUND 5 DEGREES OR SO. THE COOLEST OUTPUT HAS TEMPERATURES COOLER
THAN WHAT I HAVE THEM.
WEDNESDAY...SLOW MOVING UPPER SYSTEM WILL KEEP RAINFALL AROUND
THROUGH THE MORNING HOURS IN THE SOUTHEAST HALF. IF THERE IS ANY
MORE SLOWLY...THE POPS WILL NEED TO BE RAISED. TEMPERATURES WILL BE
A LITTLE WARMER BUT HOW MUCH WILL DEPEND ON HOW FAST THE SYSTEM AND
ASSOCIATED CLOUDS/RAINFALL MOVE OUT OF THE AREA. AGAIN IF ANY MORE
SLOWING TEMPERATURES WILL NEED TO BE LOWERED.
WEDNESDAY NIGHT THROUGH SUNDAY...NOT TOO MUCH HAS CHANGED FROM WHAT
THE MODELS HAVE BEEN DOING/SHOWING FROM THE LAST FEW DAYS. MODELS
STILL DIFFER ON THE AMPLITUDED AND POSITION OF WHAT IS NOW THE
SOUTHERN RIDGE THAT TRANSITIONS TO A MORE CENTERED WESTERN RIDGE. IN
GENERAL UPPER RIDGE STAYS CENTERED NEAR THE FOUR CORNERS REGION.
SINCE MUCH DOES CHANGE ALOFT...THE SURFACE ALSO DOES NOT CHANGE TOO
MUCH. A SURFACE TROUGH OR LINGERING FRONTAL BOUNDARY STAYS NEAR OR
OVER THE WESTERN PORTION OF THE AREA.
FORECAST WILL HINGE ON SMALL IMPORTANT DETAILS THAT WILL BE HARD TO
PIN DOWN AT THIS TIME SCALE. POSITION OF THE RIDGE SHOULD ALLOW
SUBTROPICAL MOISTURE/WEAK SHORTWAVE TROUGHS TO ROTATE AROUND THE
RIDGE INTO THE AREA. ALSO THE SURFACE BOUNDARY SHOULD HELP SET
THUNDERSTORMS OFF. THERE WILL NOT BE HIGH PRECIPITATION CHANCES BUT
HARD TO SAY THERE WILL NOT BE ANYTHING AT ALL. PER THE OVERNIGHT
DISCUSSION/REASONING...THE WESTERN PORTION OF THE AREA WILL PROBABLY
SEE THE BEST CHANCE DUE TO THE PROXIMITY OF THE SURFACE BOUNDARY.
THE NEW CRH_INIT IS IN GOOD AGREEMENT WITH THE ABOVE MENTIONED
SCENARIO/REASONING...SO ONCE AGAIN MADE NO CHANGES TO IT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1131 PM MDT SUN AUG 9 2015
VFR CONDITIONS ARE EXPECTED AT KGLD FOR THE NEXT 24 HOURS. LATER
TONIGHT, BOUNDARY LAYER RH INCREASES TO 90 PERCENT OR MORE IN AN
AREA INCLUDING KMCK. CONDITIONS THERE MAY GET AS LOW AS IFR. VFR
CONDITIONS WILL RETURN TO KMCK BY MID MORNING. LATER MONDAY
AFTERNOON AND EVENING THERE IS A SLIGHT CHANCE OF THUNDERSTORMS
NEAR KGLD SO WILL INCLUDE VCTS. KMCK SHOULD NOT HAVE THUNDERSTORMS
UNTIL AFTER 06Z TUESDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1159 PM CDT SUN AUG 9 2015
...UPDATE TO SHORT TERM CONVECTIVE FORECAST AND AVIATION FORECAST
DISCUSSION...
.UPDATE...
ISSUED AT 1152 PM CDT SUN AUG 9 2015
WHILE FORCING MECHANISMS REMAIN WEAK, THE ATMOSPHERE REMAINS QUITE
UNSTABLE WITH 2000-4000 J/KG OF MUCAPE ROOTED 2-3K FEET OFF THE
SURFACE. EFFECTIVE SHEAR IS SUFFICIENT TO SUSTAIN SUPERCELL
STRUCTURES MAINLY OVER NORTHERN PARTS OF THE AREA AND THE STORM
OVER REPUBLIC COUNTY HAS SHOWN SIGNS OF ORGANIZATION ALTHOUGH IT
HAS SO FAR REMAINED BELOW SEVERE LIMITS AND STRUGGLED TO REMAIN
ORGANIZED FOR A PROLONGED PERIOD. AN ADDITIONAL AREA OF
CONVERGENCE AND INCREASING CLOUD COVER IN THE 3500 FOOT AGL RANGE
INDICATE THAT ADDITIONAL SCATTERED STORMS MAY DEVELOP GENERALLY
ALONG THE I-70 CORRIDOR IN THE NEXT COUPLE OF HOURS AND THEN
PERHAPS INTO EAST CENTRAL KANSAS. BASICALLY, THERE ARE SEVERAL
AREAS OF WEAK FORCING AND WHETHER OR NOT ANY OF THESE AREAS CAN
INITIATE CONVECTION ARE THE PRIMARY QUESTION. IF STORMS DEVELOP, A
FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH WIND REMAINING THE
PRIMARY HAZARD ALONG WITH POCKETS OF HEAVY RAIN AND A SMALL CHANCE
FOR MARGINALLY SEVERE HAIL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
CURRENT SURFACE ANALYSIS SHOWS THE MAIN SYNOPTIC BOUNDARY EXTENDING
SOUTHWARD FROM KANSAS CITY TO WICHITA, WHICH IS FORECAST TO SAG
SOUTHWARD THROUGH THE AFTERNOON AND EVENING HOURS. ALTHOUGH THE MORE
EVIDENT THERMAL GRADIENT HAS PUSHED INTO SOUTHEAST KS AND HAS BEEN
RESPONSIBLE FOR SCATTERED SHOWERS AND ISOLATED THUNDER THIS MORNING.
THIS HAS KEPT THE CLOUD COVER AROUND MUCH LONGER THAN FORECASTED,
BUT AN AREA OF CLEAR SKIES IS WORKING EASTWARD ACROSS NORTHEAST KS,
WHICH MAY ALLOW TEMPERATURES TO WARM INTO THE LOWER TO MIDDLE 90S.
HIGH MOISTURE POOLING IN THE BOUNDARY LAYER HAS KEPT DEW POINTS IN
THE MID TO UPPER 70S. EXPECT THAT HEAT INDICES WILL BE IN THE LOWER
100S THROUGH EARLY EVENING FOR LOCATIONS ALONG AND SOUTH OF I-70.
THERE WILL BE A FEW THINGS OF CONCERN LATER THIS EVENING AND
OVERNIGHT. THE MODELS SHOW A SHORTWAVE TROUGH ON THE NORTHERN
PERIPHERY OF THE UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS WILL
TRACK ACROSS SOUTHERN KS TONIGHT. THIS MAY SUPPORT THE DEVELOPMENT
OF AN MCS OR MULTICELL CLUSTER IN WESTERN OR CENTRAL KS THIS EVENING
NORTH OF THE SURFACE BOUNDARY. SURFACE BASED CONVECTION HAS ALREADY
BEGAN IN NORTHWEST KS. AS THAT BOUNDARY DRIFTS SOUTHWARD THE TRACK
OF THE MCS MAY ALSO DO THE SAME AS DEPICTED BY THE NAM. THE PAST FEW
RUNS OF THE HRRR HAVE BEEN CLIPPING THE SOUTHERN FORECAST AREA WITH
THIS MCS. INSTABILITY HAS BEEN SOMEWHAT LIMITED TODAY ACROSS
SOUTHERN KS AS OPPOSED TO NORTHERN KS, WHICH HAS SET UP A DECENT
GRADIENT. THEREFORE IT IS UNCERTAIN HOW SEVERE THESE STORMS WILL BE
THIS EVENING, BUT THE TRACK MAY BE MORE FOCUSED ALONG THIS
INSTABILITY GRADIENT INSTEAD. AS FOR NOW THE BEST CHANCES FOR PRECIP
WILL BE SOUTH OF I-70 LATE THIS EVENING AND EARLY MORNING WITH THE
SLIGHT CHANCE FOR A STRONG STORM. WITH PLENTY OF MOISTURE AROUND AND
LIGHT LOW LEVEL WINDS ASSOCIATED WITH THE BOUNDARY THERE IS A CHANCE
FOR HAZE AND OR FOG EARLY TOMORROW MORNING. THERE ARE SOME
INDICATIONS THAT THE SKIES COULD CLEAR LATE TONIGHT AND ALLOW FOR
BOUNDARY LAYER COOLING. A FEW OF THE MODELS ARE HINTING AT A
NORTHERN SHORTWAVE THAT WILL TRACK OVER SD AND NE OVERNIGHT. THIS
MAY ALSO SUPPORT A SOUTHEASTWARD MOVING MCS THAT COULD REACH
NORTHERN KS AROUND SUNRISE. IN FACT, THE INSTABILITY IS ALREADY
DECENT IN THAT AREA, WHICH WOULD SUPPORT THIS SCENARIO BETTER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
THERE IS NOT MUCH CHANGE IN THE FORECAST FOR MONDAY NIGHT THROUGH
SUNDAY AS MODELS CONTINUE TO SHOW AN UPPER LEVEL RIDGE AMPLIFYING
TO THE WEST AND SOUTHWEST CAUSING NORTHWEST FLOW TO SET UP OVER
THE FORECAST AREA. ABOUT THE ONLY THING OF CONCERN IS THE
POSSIBILITY FOR SOME ELEVATED PRECIP ACROSS NORTH CENTRAL KS LATE
TUESDAY NIGHT AND WEDNESDAY MORNING. THERE ARE INDICATIONS THAT
CONVECTION IN THE MOUNTAINS COULD GENERATE A VORT MAX AND THEN
DRIFT EAST AND SOUTH THROUGH CENTRAL KS. FOR NOW MOST GUIDANCE
KEEPS ANY PRECIP JUST TO THE WEST OF THE FORECAST AREA. THIS SEEMS
TO MAKE SINCE AS MODELS BRING THE CENTER OF THE 850 MB RIDGE OVER
THE FORECAST AREA BY 12Z WED WITH NO REAL RETURN FLOW AND THE
DEEPER MOISTURE AXIS REMAINING OVER WESTERN KS. SO THE FORECAST
REMAINS DRY THROUGH NEXT WEEKEND WITH NO OBVIOUS SIGNS OF FORCING
IMPACTING THE FORECAST AREA AFTER WEDNESDAY.
TEMPS ARE EXPECTED TO BE COOLER THAN NORMAL FOR TUESDAY THROUGH
THURSDAY. MODELS ARE IN AGREEMENT THAT A MODIFIED HIGH PRESSURE
SYSTEM WILL BUILD INTO THE AREA WITH SOME WEAK COLD AIR ADVECTION
AND DRYER AIR. BECAUSE OF THIS LOWS SHOULD BE IN THE LOWER AND MID
60S WITH HIGHS IN THE 80S. BY FRIDAY AND INTO THE WEEKEND, THE
UPPER RIDGE IS EXPECTED TO PROPAGATE EAST INTO THE PLAINS AS AN
UPPER TROUGH OVER THE PACIFIC NORTHWEST COAST MOVES INLAND. THIS
SHOULD SHIFT THE THERMAL RIDGE OUT INTO THE PLAINS WITH HIGHS
WARMING BACK INTO THE LOWER AND MID 90S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1152 PM CDT SUN AUG 9 2015
LOWER THAN NORMAL CONFIDENCE CONTINUES IN THE TAF. SCATTERED
THUNDERSTORMS MAY DEVELOP NEAR/OVER TAF SITES AT JUST ABOUT ANY
TIME THROUGH 13 OR 14Z. OTHERWISE DO EXPECT MVFR CIGS TO DEVELOP
IN THE NEXT FEW HOURS, PROBABLY BY 08Z...AND WITH SUCH AMPLE LOW
LEVEL MOISTURE MAY SEE SOME VIS RESTRICTIONS ESPECIALLY AFTER 09Z.
CIGS, LIKELY IN THE MVFR RANGE, EXPECTED TO CONTINUE THROUGH
AROUND NOON BEFORE SCATTERING OUT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...SANDERS
LONG TERM...WOLTERS
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 AM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 150 AM EDT MON AUG 10 2015
UPPER WAVE RIDING THROUGH THE FLOW HAS FIRED OFF SOME SHOWERS
AHEAD OF MAIN SURFACE LOW PRESSURE/COLD FRONT STILL DEVELOPING
ACROSS THE MIDWEST THIS EARLY MORNING HOUR. ALL THE PRECIP HAS
REMAINED LIGHT IN NATURE AT THIS POINT BASED OF THE LATEST WSR-88D
SWEEPS. DID UPDATE GRIDS TO ADD AT LEAST SOME ISOLATED POPS ACROSS
MUCH OF THE REGION OVERNIGHT...OTHERWISE MINOR ADJUSTMENTS MADE TO
THE TEMPS/DEWS/WINDS TOWARD LATEST OBS/TRENDS.
UPDATE ISSUED AT 1045 PM EDT SUN AUG 9 2015
A SHORTWAVE MOVING THROUGH THE OH VALLEY REGION IS BRINGING SOME
SHOWERS TO SOUTHERN OH AND NORTHERN KY. KCVG ONLY TRACED AS THESE
PASSED...SO THESE LIKELY DO NOT AMOUNT TO MUCH MORE THAN
SPRINKLES. OTHERWISE...MODELS INDICATE ADDITIONAL CONVECTION
UPSTREAM WILL MOVE EAST AND OR DEVELOP AND MOVE EAST TO EAST
SOUTHEAST AS IT WORKS AROUND THE MID LEVEL RIDGE CENTERED OVER THE
SOUTHERN PLAINS. DUE TO UNCERTAINTY IN TIMING AND MODEL
DIFFERENCES IN EVOLUTION OF CONVECTION OVERNIGHT AND INTO THE DAY
ON MONDAY...NO CHANGES WERE MADE TO POPS TOWARD DAWN. THE ONLY
CHANGES TO POPS WERE IN THE SHORT TERM TO ACCOUNT FOR THE SHOWERS
MOVING TOWARD NE KY. OTHERWISE...HOURLY GRIDS WERE FRESHENED UP
BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS.
UPDATE ISSUED AT 820 PM EDT SUN AUG 9 2015
A MID LEVEL RIDGE OF HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH A SERIES OF SHORTWAVES MOVING THROUGH OR NEARING THE
LOWER OH VALLEY AS THEY MOVE AROUND THIS RIDGE. AT THE SAME TIME...
A SERIES OF SHORTWAVE TROUGH WILL APPROACH OR MOVE THROUGH THE
GREAT LAKES. ALL OF THIS WILL BEGIN TO CARVE OUT AN EASTERN US
TROUGH WHILE THE RIDGE BUILDS NORTH INTO THE NORTHERN ROCKIES. AT
THE SFC..AN AREA OF LOW PRESSURE WILL TRACK INTO THE LOWER GREAT
LAKES WITH THE WARM FRONT LIFTING INTO THE REGION WHILE A COLD
FRONT MOVES INTO THE LOWER OH VALLEY. OVERALL...MOISTURE AND
FORCING WILL INCREASE OVERNIGHT ACROSS THE OH VALLEY REGION...BUT
CONFIDENCE REMAINS LOW IN THE EVOLUTION OF CONVECTION OVERNIGHT.
WITH RECENT MODEL GUIDANCE STILL SUPPORTING CHANCES FOR CONVECTION
LATE TONIGHT AND SOME DISAGREEMENT AS TO WHERE CHANCES MAY BE
BEST...NO CHANGES WERE MADE TO POPS AND WEATHER ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 115 AM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL ACROSS EASTERN KY THIS OVERNIGHT HOUR.
THERE ARE A FEW SHOWERS AND SPRINKLES THAT HAVE DEVELOPED ACROSS
PORTIONS OF THE REGION...SO DID GO WITH SOME VCSH AT MOST
SITES. HOWEVER SITES SHOULD REMAIN VFR THROUGH MUCH OF THE
BEGINNING OF THE PERIOD. UPSTREAM MCS RELATED CONVECTION IN
WESTERN KY HAS BEEN ON A WEAKENING TREND AND WILL PROBABLY MISS
THE REGION IN GENERAL. OTHERWISE THINK THE BETTER CONVECTION WILL
DEVELOP LATER MORNING INTO THE AFTERNOON HOURS. THEREFORE STAYED
CLOSE TO THE PREVIOUS FORECAST WITH TEMPO GROUP TO EXPRESS DROPS
TO MVFR/IFR AT TIMES TOMORROW AFTERNOON AND EARLY EVENING. WINDS
WILL BE GENERALLY LIGHT THROUGH THE PERIOD WITH HIGHER GUSTS
POSSIBLE IN STRONGER STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
115 AM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1045 PM EDT SUN AUG 9 2015
A SHORTWAVE MOVING THROUGH THE OH VALLEY REGION IS BRINGING SOME
SHOWERS TO SOUTHERN OH AND NORTHERN KY. KCVG ONLY TRACED AS THESE
PASSED...SO THESE LIKELY DO NOT AMOUNT TO MUCH MORE THAN
SPRINKLES. OTHERWISE...MODELS INDICATE ADDITIONAL CONVECTION
UPSTREAM WILL MOVE EAST AND OR DEVELOP AND MOVE EAST TO EAST
SOUTHEAST AS IT WORKS AROUND THE MID LEVEL RIDGE CENTERED OVER THE
SOUTHERN PLAINS. DUE TO UNCERTAINTY IN TIMING AND MODEL
DIFFERENCES IN EVOLUTION OF CONVECTION OVERNIGHT AND INTO THE DAY
ON MONDAY...NO CHANGES WERE MADE TO POPS TOWARD DAWN. THE ONLY
CHANGES TO POPS WERE IN THE SHORT TERM TO ACCOUNT FOR THE SHOWERS
MOVING TOWARD NE KY. OTHERWISE...HOURLY GRIDS WERE FRESHENED UP
BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS.
UPDATE ISSUED AT 820 PM EDT SUN AUG 9 2015
A MID LEVEL RIDGE OF HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH A SERIES OF SHORTWAVES MOVING THROUGH OR NEARING THE
LOWER OH VALLEY AS THEY MOVE AROUND THIS RIDGE. AT THE SAME TIME...
A SERIES OF SHORTWAVE TROUGH WILL APPROACH OR MOVE THROUGH THE
GREAT LAKES. ALL OF THIS WILL BEGIN TO CARVE OUT AN EASTERN US
TROUGH WHILE THE RIDGE BUILDS NORTH INTO THE NORTHERN ROCKIES. AT
THE SFC..AN AREA OF LOW PRESSURE WILL TRACK INTO THE LOWER GREAT
LAKES WITH THE WARM FRONT LIFTING INTO THE REGION WHILE A COLD
FRONT MOVES INTO THE LOWER OH VALLEY. OVERALL...MOISTURE AND
FORCING WILL INCREASE OVERNIGHT ACROSS THE OH VALLEY REGION...BUT
CONFIDENCE REMAINS LOW IN THE EVOLUTION OF CONVECTION OVERNIGHT.
WITH RECENT MODEL GUIDANCE STILL SUPPORTING CHANCES FOR CONVECTION
LATE TONIGHT AND SOME DISAGREEMENT AS TO WHERE CHANCES MAY BE
BEST...NO CHANGES WERE MADE TO POPS AND WEATHER ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 115 AM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL ACROSS EASTERN KY THIS OVERNIGHT HOUR.
THERE ARE A FEW SHOWERS AND SPRINKLES THAT HAVE DEVELOPED ACROSS
PORTIONS OF THE REGION...SO DID GO WITH SOME VCSH AT MOST
SITES. HOWEVER SITES SHOULD REMAIN VFR THROUGH MUCH OF THE
BEGINNING OF THE PERIOD. UPSTREAM MCS RELATED CONVECTION IN
WESTERN KY HAS BEEN ON A WEAKENING TREND AND WILL PROBABLY MISS
THE REGION IN GENERAL. OTHERWISE THINK THE BETTER CONVECTION WILL
DEVELOP LATER MORNING INTO THE AFTERNOON HOURS. THEREFORE STAYED
CLOSE TO THE PREVIOUS FORECAST WITH TEMPO GROUP TO EXPRESS DROPS
TO MVFR/IFR AT TIMES TOMORROW AFTERNOON AND EARLY EVENING. WINDS
WILL BE GENERALLY LIGHT THROUGH THE PERIOD WITH HIGHER GUSTS
POSSIBLE IN STRONGER STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
509 AM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 119 AM EDT MON AUG 10 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN MAY STILL BRUSH KSAW EARLY
IN THE TAF PERIOD. OTHERWISE...MAINLY DRY CONDITIONS ARE EXPECTED
OVERNIGHT AT KCMX/KIWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA OVERNIGHT AND BREAKS IN
THE CLOUDS OCCUR...EXPECT SOME SHALLOW FOG TO DEVELOP AT ALL THREE
TERMINALS...ESPECIALLY AT KSAW WHERE RAIN FELL AND THE LIGHTEST
WINDS WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST
TERMINALS...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE
NIGHT WHICH WILL RESULT IN MORE MIXING INTO THE DRIER AIR ALOFT.
FOR TODAY...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE AFTERNOON AND EVENING.
SCT/ISOLD SHRA MAY BE POSSIBLE DURING THE EVENING BUT SHOULD HAVE
LITTLE IMPACT ON CIGS/VSBY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
240 AM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 119 AM EDT MON AUG 10 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN MAY STILL BRUSH KSAW EARLY
IN THE TAF PERIOD. OTHERWISE...MAINLY DRY CONDITIONS ARE EXPECTED
OVERNIGHT AT KCMX/KIWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA OVERNIGHT AND BREAKS IN
THE CLOUDS OCCUR...EXPECT SOME SHALLOW FOG TO DEVELOP AT ALL THREE
TERMINALS...ESPECIALLY AT KSAW WHERE RAIN FELL AND THE LIGHTEST
WINDS WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST
TERMINALS...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE
NIGHT WHICH WILL RESULT IN MORE MIXING INTO THE DRIER AIR ALOFT.
FOR TODAY...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE AFTERNOON AND EVENING.
SCT/ISOLD SHRA MAY BE POSSIBLE DURING THE EVENING BUT SHOULD HAVE
LITTLE IMPACT ON CIGS/VSBY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 AM EDT MON AUG 10 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 PM EDT SUN AUG 9 2015
SHOWERS AND THUNDERSTORMS CHANCES WILL INCREASE TONIGHT INTO MONDAY.
MANY AREAS SHOULD SEE AROUND A HALF INCH OF RAIN IN THIS PERIOD...
HOWEVER SEVERE WEATHER IS GENERALLY NOT EXPECTED. A FEW SHOWERS MAY
LINGER INTO MONDAY EVENING...BUT WE SHOULD GRADUALLY DRY OUT...
MAKING FOR A PLEASANT TUESDAY WITH LESS HUMIDITY.
MUCH OF THE REMAINDER OF THE WEEK LOOKS DRY WITH NEAR OR SLIGHTLY
ABOVE NORMAL TEMPERATURES...WITH DAYTIME HIGHS GENERALLY 80 TO 85.
A WIDELY SCATTERED THUNDERSTORM WILL BE POSSIBLE ON THURSDAY.
&&
.UPDATE...
ISSUED AT 1050 PM EDT SUN AUG 9 2015
I HAVE UPDATED THE FORECAST TO INCREASE THE RISK FOR THUNDERSTORMS
TOWARD MORNING OVER OUR SOUTHWEST CWA THEN SPREAD THAT CONVECTION
EASTWARD. WE ALREADY HAD LIKELY POP FOR MONDAY MORNING AFTER 8
AM...SO THIS JUST STARTS THE CONVECTION A TOUCH SOONER.
WHAT I AM SEEING FROM BOTH THE WATER VAPOR IMAGE LOOPS AND
WATCHING THE RAP MODEL HOURLY IS THAT WE HAVE A JET EXIT REGION
WITH DECENT PVU (POTENTIAL VORTICITY) IN THE 500 TO 300 MB LAYER
COMING THROUGH THE I-94 TO I-96 AREA BETWEEN 4 AM AND 9 AM THIS
MORNING. A WEAK LLJ DEVELOPS IN RESPONSE TO THIS AIMED AT AZO
BTW 8 AM AND 10 AM. SINCE THE HRRR...HRRR EXPERIMENTAL...AND
RAP13 HAVE BEEN RATHER CONSISTENT WITH THIS AND IT MAKES SENSE
GIVEN WHAT IS GOING ON NOW... I AM DID UPDATE THE GRIDS TO REFLECT
THE IDEA OF THUNDERSTORMS TOWARD MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 326 PM EDT SUN AUG 9 2015
RAIN CHANCES OVER SW MI WILL PEAK DURING THE FIRST HALF OF MONDAY AS
A COLD FRONT APPROACHES. GIVEN THE FRONT/S TIMING SEVERE WEATHER IS
GENERALLY NOT EXPECTED. WE DRY OUT MONDAY EVENING...BECOMING COOLER
AND LESS HUMID INTO TUESDAY.
A COLD FRONT WAS MOVING ACROSS THE MN/WI BORDER THIS AFTERNOON AND
HAS AN AREA OF SHOWERS AND STORMS WITH IT. THE STRONGEST AREA OF
STORMS WAS ASSOCIATED WITH THE LEFT EXIT REGION OF THE UPPER JET.
THE FRONT AND THE UPPER JET WILL MAKE IT/S WAY THROUGH THE CWA
MONDAY MORNING INTO EARLY AFTERNOON...NORMALLY A MIN TIME FOR SEVERE
WX. THIS LIKELY FAVORS AREAS TO OUR EAST FOR THE POTENTIAL OF
STRONGER STORMS. THE OTHER PARAMETER GOING AGAINST SEVERE STORMS IS
THAT THE 0-6 KM BULK SHEAR IS ONLY 20-25 KNOTS OVER SW MI AS THE
FRONT COMES THROUGH.
HOWEVER THE FRONT WILL BE HEADING INTO A JUICY AIR MASS WITH DEW
POINTS AROUND 70 ALONG I-94...AND MID TO UPPER 60S ELSEWHERE ACROSS
THE CWA. SO EXPECT THE STORMS OVER MN/WI TO HOLD TOGETHER AND
EXPAND...BRINGING A BENEFICIAL RAIN TO MOST OF THE CWA LATE TONIGHT
INTO MONDAY. RAIN TOTALS WILL VARY GREATLY GIVEN THE CONVECTIVE
NATURE...BUT MOST AREAS SHOULD SEE A HALF TO THREE QUARTERS OF INCH
OF RAIN. THE SHOWERS AND STORMS WILL END FROM WEST TO EAST WITH THE
FRONTAL PASSAGE MONDAY AFTERNOON INTO THE EVENING.
COOLER AND LESS HUMID AIR WILL FILTER IN BEHIND THE FRONT. HIGHS IN
THE 70S CAN BE EXPECTED FOR TUESDAY AS THE UPPER FLOW BECOMES
NORTHWESTERLY. OUTSIDE CHANCE THAT A FEW SHOWERS MAY POP UP ACROSS
CENTRAL LOWER TUESDAY DUE TO THE COOL AIR ALOFT. I DID NOT ADD
THIS...BUT I DID INCREASE THE CLOUD COVER IN THE FORECAST. WE
SHOULD SEE DIURNAL CU AT THE VERY LEAST...WHICH SHOULD BECOME BKN TO
OVC AT TIMES DURING THE AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 326 PM EDT SUN AUG 9 2015
FAIR WEATHER IS ANTICIPATED WEDNESDAY WITH A HIGH PRESSURE RIDGE
CENTERED OVER THE LOWER GREAT LAKES REGION STILL IN CONTROL OF THE
WX PATTERN.
IT WILL TURN WARMER AND MORE HUMID THURSDAY IN SW FLOW OUT AHEAD OF
AN APPROACHING COLD FRONT. THE COLD FRONT WILL BRING A CHANCE OF
RAIN AND THUNDERSTORMS LATE THURSDAY THROUGH THURSDAY NIGHT INTO
FRIDAY.
FAIR WX WILL RETURN BEHIND THAT SYSTEM FOR FRIDAY NIGHT THROUGH THE
WEEKEND AS A HIGH PRESSURE RIDGE BUILDS SLOWLY EAST ACROSS THE GREAT
LAKES REGION. TEMPERATURES NEXT WEEKEND WILL AVERAGE NEAR TO
SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 123 AM EDT MON AUG 10 2015
SCATTERED SHOWERS WILL CONTINUE TO DEVELOP OVERNIGHT AS SOUTH FLOW
AHEAD OF A COLD FRONT INCREASES. MVFR CIGS/VSBYS POSSIBLE PRIOR TO
AND JUST AFTER SUNRISE.
A COLD FRONT MAY TRIGGER NON SEVERE STORMS THIS
AFTERNOON...ESPECIALLY NEAR THE EASTERN TAF SITES.
&&
.MARINE...
ISSUED AT 326 PM EDT SUN AUG 9 2015
RATHER QUIET CONDITIONS ARE EXPECTED ON THE TONIGHT INTO MONDAY.
HOWEVER NORTHERLY WINDS WILL INCREASE BEHIND THE FRONT AND WAVES
WILL BEGIN TO BUILD MONDAY EVENING INTO TUESDAY. PEAK WINDS AND
WAVES SHOULD OCCUR INTO TUESDAY...AND WE MAY NEED A SMALL CRAFT
ADVISORY BY TUESDAY AFTERNOON. WINDS AND WAVES SHOULD THEN DIMINISH
LATE TUESDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 PM EDT SUN AUG 9 2015
NO HYDRO IMPACTS ARE EXPECTED OVER THE NEXT WEEK. THE CHANCE FOR
SCATTERED SHOWERS WILL INCREASE THROUGH THE AFTERNOON AND ESPECIALLY
THE EVENING. RAIN CHANCES ARE HIGHEST THIS EVENING INTO MONDAY
AFTERNOON ALONG WITH THE POTENTIAL FOR ISOLATED STORMS. STORM
CHANCES WILL BE HIGHEST EARLY MONDAY AFTERNOON ACROSS THE EASTERN
FORECAST AREA. WE COULD SEE A FEW STRONG STORMS AT THAT TIME CAPABLE
OF LOCALLY HIGHER RAINFALL AMOUNTS. BUT IN GENERAL...WIDESPREAD
RAINFALL IS FORECAST TO REMAIN BELOW 0.75 INCHES AND MOST LIKELY IN
THE 0.25 TO 0.50 INCH RANGE. ANY RAINFALL TONIGHT INTO MONDAY WILL
LIKELY BE BENEFICIAL FOR MOST.
OUTLOOK...THE REST OF THE WORK WEEK LOOKS QUIET AND MAINLY DRY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...LAURENS
AVIATION...04
HYDROLOGY...EBW
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 AM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN AUG 9 2015
A NW FLOW BTWN AN UPR RDG IN THE PLAINS AND A DOWNSTREAM TROF OVER
ERN CANADA WL DOMINATE THE GREAT LKS EARLY THIS WEEK...BRINGING A
PERIOD OF BLO NORMAL TEMPS FOR MON NGT INTO WED. WARMER WX AND A CHC
OF SHOWERS/TS WL THEN BE THE RULE ON THU IN ADVANCE OF A COLD FNT
ASSOCIATED WITH A DISTURBANCE DROPPING SEWD THRU NW ONTARIO. EXPECT
DRY AND A BIT COOLER WX LATE IN THE WEEK WITH HI PRES TRAILING THE
FNT. THE NEXT CHC OF SHOWERS/TS AND WARMER WX WL RETURN NEXT SUN
AHEAD OF THE NEXT SHRTWV/COLD FNT TOPPING THE PERSISTENT UPR RDG IN
THE PLAINS.
MON NGT...SHRTWV DIVING SEWD IN THE NW FLOW ALF BTWN PLAINS RDG AND
ERN TROF IS FCST TO DIG THRU THE AREA. SOME OF THE MODELS SHOW SOME
WEAK DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE PVA AHEAD OF THIS
DISTURBANCE AND GENERATE SOME SPOTTY LGT PCPN OVER THE AREA...MAINLY
OVER THE HIER TERRAIN NEAR LK SUP WITH UPSLOPE N WINDS. BUT ABSENCE
OF STRONGER FORCING AND ARRIVAL OF THIS DISTURBANCE DURING PERIOD OF
NOCTURNAL COOLING WL LIMIT INTENSITY AND COVERAGE OF ANY SHOWERS. DO
EXPECT MORE LO CLDS IN THESE UPSLOPE AREAS WITH AN INCRS IN LLVL RH
AS H85 TEMPS WITHIN THERMAL TROF FALL TO 8-10C BY 12Z TUE. STEADY N
WINDS WL LIMIT THE DIURNAL TEMP FALL DESPITE THE LLVL COOLING TREND.
MOST PLACES SHOULD SEE MINS IN THE 50S...WITH THE LOWER TEMPS AT THE
COOLER SPOTS OVER THE INTERIOR W HALF WHERE THE WINDS WL BE A BIT
LIGHTER CLOSER TO SFC HI PRES RDG BLDG INTO MN.
TUE/TUE NGT...EXPECT DRY WX TO PREVAIL DURING THIS TIME UNDER
CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR DVGC/SUBSIDENCE LEFT IN THE
WAKE OF EXITING SHRTWV. SC IN THE UPSLOPE AREAS ON TUE MRNG SHOULD
EXPAND WITH DAYTIME HEATING UNDER THERMAL TROF...BUT CLOSER APRCH OF
SFC HI PRES FCST TO ARRIVE OVER THE W BY 00Z WED/INCRSGLY ACYC LLVL
FLOW/LOWERING SUBSIDENCE INVRN WL LIKELY RESULT IN MORE SUNSHINE W-E
THRU THE AFTN. UNDER MOCLR SKIES...TUE NGT WL BE COOL ESPECIALLY
OVER THE INTERIOR W HALF WITH LIGHTER WINDS CLOSER TO SFC HI PRES
RDG SINKING INTO WI. BUT WITH MIN PWAT NOT MUCH BLO 0.75 INCH IN
THIS AREA...DO NOT EXPECT MIN TEMPS TO BE TOO CHILLY.
WED/WED NGT...SFC HI PRES IS FCST TO SINK S INTO THE MID MS RIVER
VALLEY THRU THIS TIME. AS THE MSLP FALLS OVER NW ONTARIO IN ADVANCE
OF SHRTWV RIDING OVER THE TOP OF PLAINS RDG INTO FAR NW ONTARIO...
UPR MI WL BE DOMINATED BY AN INCRSG WSW FLOW. EXPECT SOME CLDS
ASSOCIATED WITH BAND OF INCRSG WAA/ISENTROPIC ASCENT BEST SHOWN ON
THE 300-305K SFCS TO IMPACT THE UPR LKS WED AFTN/EVNG. MANY OF THE
MODELS GENERATE SOME PCPN AS WELL...BUT RELATIVE DRYNESS OF THE
LLVLS AND MODEST PWAT FCST NEAR 1 INCH /ABOUT NORMAL/ WARRANT ONLY
LO CHC POPS.
THU/THU NGT...SHRTWV OVER FAR NW ONTARIO AT 12Z THU IS PROGGED TO
SLIDE SE INTO WRN QUEBEC THU NGT AND DRAG A COLD FNT ACRS UPR MI
SOMETIME THU AFTN/EVNG. ARRIVAL OF THIS BNDRY/BAND OF MODEST DEEP
LYR FORCING AT A TIME WHEN DAYTIME HEATING WL HAVE AN IMPACT FAVORS
SOME SHOWERS/TS...BUT ABSENCE OF MUCH IN THE WAY OF HGT FALLS WELL
TO THE SW OF TRACK OF SHRTWV/SHARPEST FORCING...QUESTIONS ABOUT
DEGREE OF MSTR INFLOW AHEAD OF THE FNT AND TIMING DIFFERENCES AMONG
THE MODELS ON FROPA TIMING WARRANT NO HIER THAN LO CHC POPS ATTM.
THU LOOKS TO BE A WARM DAY WITH H85 TEMPS PUSHING 18-20C AHEAD OF
THE FNT.
EXTENDED...HI PRES TRAILING THE COLD FROPA WL BRING MOCLR WX FOR FRI
AND SAT. FRI WL BE COOLER WITH H85 TEMPS DIPPING TO ARND 14C...BUT
THEN SAT WL TURN WARMER AS THE HI SHIFTS TO THE E AND RETURN SSW
FLOW LIFTS H85 TEMPS UP TO 16C. THE NEXT CHC OF SHOWERS/TS WL ARRIVE
ON SUN AHEAD OF NEXT DISTURBANCE RIDING OVER THE PLAINS RDG.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 119 AM EDT MON AUG 10 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN MAY STILL BRUSH KSAW EARLY
IN THE TAF PERIOD. OTHERWISE...MAINLY DRY CONDITIONS ARE EXPECTED
OVERNIGHT AT KCMX/KIWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA OVERNIGHT AND BREAKS IN
THE CLOUDS OCCUR...EXPECT SOME SHALLOW FOG TO DEVELOP AT ALL THREE
TERMINALS...ESPECIALLY AT KSAW WHERE RAIN FELL AND THE LIGHTEST
WINDS WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST
TERMINALS...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE
NIGHT WHICH WILL RESULT IN MORE MIXING INTO THE DRIER AIR ALOFT.
FOR TODAY...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE AFTERNOON AND EVENING.
SCT/ISOLD SHRA MAY BE POSSIBLE DURING THE EVENING BUT SHOULD HAVE
LITTLE IMPACT ON CIGS/VSBY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 AM CDT MON AUG 10 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 10 2015
EXPECT A FEW SHOWERS OR THUNDERSTORMS TO LINGER INTO EARLY THIS
EVENING, BUT SHOULD BE GONE BEFORE MIDNIGHT. DRIER AIR IS FORECAST
TO BUILD ACROSS THE AREA BEHIND THE FRONT TONIGHT AND TUESAY...AND
LAST AT LEAST THROUGH THE END OF THE WEEK WITH DEWPOINT
TEMPERATURES DROPPING INTO THE 60S. A HIGH AMPLITUDE UPPER LEVEL
PATTERN LOCKS THE DRY LOW LEVEL RIDGE OVER THE MISSISSIPPI VALLEY,
SO PRECIPITATION CHANCES ARE VIRTUALLY NIL. THIS SHOULD MAKE FOR
RELATIVELY COMFORTABLE WEATHER FOR WHAT ARE TYPICALLY THE DOG-DAYS
OF SUMMER WITH HIGHS NEAR OR A FEW DEGREES BELOW NORMAL IN THE MID
TO UPPER 80S AND LOWS WELL BELOW NORMAL IN THE 60S.
CARNEY
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1056 PM CDT SUN AUG 9 2015
BACKBUILDING MCS JUST EAST AND SOUTH OF THE ST LOUIS METRO AREA.
THERE MAY CONTINUE TO BE ISOLATED SHOWERS/STORMS IMPACTING THE ST
LOUIS AREA TAFS UNTIL AROUND 08Z MON. COULD NOT RULE OUT SOME
ADDITIONAL DEVELOPMENT AS WELL LATE TONIGHT/EARLY MONDAY MORNING
AS A COLD FRONT MOVES SOUTHWARD THROUGH OUR AREA LATE TONIGHT AND
MONDAY MORNING. S-SWLY SURFACE WINDS WILL VEER AROUND TO A N-NWLY
DIRECTION AFTER FROPA. THE MODEL MOS GUIDANCE WAS HINTING AT POST
FRONTAL MVFR CLOUD CEILINGS MAINLY EARLY MONDAY MORNING.
SPECIFICS FOR KSTL: ISOLATED SHOWERS AND STORMS MAY CONTINUE TO
IMPACT STL LATE TONIGHT DUE TO BACKBUILDING MCS AND AS A COLD
FRONT MOVES SOUTHWARD THROUGH STL AREA AROUND 12Z MONDAY. S-SWLY
SURFACE WINDS WILL VEER AROUND TO A NWLY DIRECTION AFTER FROPA
EARLY MONDAY MORNING. THERE WILL ALSO LIKELY BE POST FRONTAL MVFR
CIGS MONDAY MORNING.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 40 30 10 5
QUINCY 83 64 84 62 / 40 30 5 0
COLUMBIA 87 67 85 63 / 40 30 5 0
JEFFERSON CITY 89 68 86 63 / 40 30 5 0
SALEM 86 70 84 63 / 40 30 10 5
FARMINGTON 86 69 84 61 / 40 30 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
333 AM CDT MON AUG 10 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (MONDAY THROUGH NEXT SUNDAY)
ISSUED AT 325 PM CDT SUN AUG 9 2015
(MONDAY THROUGH WEDNESDAY)
UPPER FLOW WILL BEGIN TO TURN OUT OF THE NORTHWEST BY TOMORROW AS
UPPER HIGH OVER OVER SOUTHERN HIGH PLAINS BEGINS TO BUILDS AND
TROUGH DIGS IN OVER THE NORTHEASTERN CONUS. THIS WILL HELP PUSH THE
SURFACE COLD FRONT THROUGH THE CWA EARLY IN THE DAY MONDAY. BOTH
THE NAM AND GFS ARE SHOWING A WEAK SHORTWAVE TROUGH MOVING ACROSS
MISSOURI AND ILLINOIS MIDDAY MONDAY. THE ASCENT FROM THE TROUGH
SHOULD BE ENOUGH TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS IN THE
INSTABILITY GENERATED BY MIDDAY OVER THE SOUTHERN CWA. ADDITIONAL
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS
NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS DURING THE AFTERNOON AS
A SECONDARY TROUGH MOVES ACROSS IOWA. CHANCES FOR RAIN WILL DECREASE
TUESDAY AND WEDNESDAY AS THE UPPER FLOW CONTINUES TO AMPLIFY AND THE
VERTICAL MOTION BECOMES MORE SUBSIDENT AS HIGH PRESSURE BUILDS INTO
THE AREA.
MOS TEMPERATURES THE NEXT FEW DAYS ARE IN REASONABLE AGREEMENT WITH
EACH OTHER AND WITH MIXING UP TO THE 900-800MB LAYER...SO HAVE
GENERALLY FOLLOWED THEM.
(THURSDAY THROUGH SUNDAY)
EXPECT A DRY PERIOD AS AREA WILL BE DOMINATED BY A LARGE AREA OF
SURFACE HIGH PRESSURE UNDER NORTHWESTERLY UPPER FLOW ALOFT. 850MB
TEMPERATURES FROM THE GFS ENSEMBLE MEAN WILL BE IN THE 12-18C RANGE
WHICH SUPPORTS HIGHS IN THE 80S.
BRITT
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1056 PM CDT SUN AUG 9 2015
BACKBUILDING MCS JUST EAST AND SOUTH OF THE ST LOUIS METRO AREA.
THERE MAY CONTINUE TO BE ISOLATED SHOWERS/STORMS IMPACTING THE ST
LOUIS AREA TAFS UNTIL AROUND 08Z MON. COULD NOT RULE OUT SOME
ADDITIONAL DEVELOPMENT AS WELL LATE TONIGHT/EARLY MONDAY MORNING
AS A COLD FRONT MOVES SOUTHWARD THROUGH OUR AREA LATE TONIGHT AND
MONDAY MORNING. S-SWLY SURFACE WINDS WILL VEER AROUND TO A N-NWLY
DIRECTION AFTER FROPA. THE MODEL MOS GUIDANCE WAS HINTING AT POST
FRONTAL MVFR CLOUD CEILINGS MAINLY EARLY MONDAY MORNING.
SPECIFICS FOR KSTL: ISOLATED SHOWERS AND STORMS MAY CONTINUE TO
IMPACT STL LATE TONIGHT DUE TO BACKBUILDING MCS AND AS A COLD
FRONT MOVES SOUTHWARD THROUGH STL AREA AROUND 12Z MONDAY. S-SWLY
SURFACE WINDS WILL VEER AROUND TO A NWLY DIRECTION AFTER FROPA
EARLY MONDAY MORNING. THERE WILL ALSO LIKELY BE POST FRONTAL MVFR
CIGS MONDAY MORNING.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 40 30 10 5
QUINCY 83 64 84 62 / 40 30 5 0
COLUMBIA 87 67 85 63 / 40 30 5 0
JEFFERSON CITY 89 68 86 63 / 40 30 5 0
SALEM 86 70 84 63 / 40 30 10 5
FARMINGTON 86 69 84 61 / 40 30 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 AM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
CHANCE FOR THUNDERSTORMS AND THEIR SEVERITY TONIGHT ARE THE PRIMARY
FORECAST CONCERNS.
THUNDERSTORMS WERE FIRING AT MID AFTERNOON ALONG A WEAK SURFACE
BOUNDARY STRETCHING FROM SOUTHEAST SOUTH DAKOTA INTO WESTERN
NEBRASKA. THESE STORMS HAVE PLENTY OF INSTABILITY AND SHEAR TO FEED
ON...SOME 2500 J/KG OF MLCAPE AND 40KT OF EFFECTIVE BULK SHEAR...AS
PER LATEST RAP OBJECTIVE ANALYSIS. ALREADY GETTING REPORTS OF SEVERE
HAIL JUST WEST OF OUR AREA WHERE VIGOROUS UPDRAFTS WERE SEEN. AND
FREEZING LEVELS ARE QUITE A BIT LOWER THAN LAST EVENING. SO A
CONTINUED HAIL THREAT IS CERTAINLY EXPECTED...WITH MODEST MICROBURST
POTENTIAL ALSO NOTED ON RAP PROGS.
PERHAPS A BIGGER SHOW WITH POTENTIALLY MORE WIDESPREAD SEVERE LATER
THIS EVENING IS POSSIBLE. MID LEVEL SHORTWAVE DIVING INTO WESTERN
SOUTH DAKOTA WILL CONTINUE SOUTHEAST THIS EVENING...PUSHING A COLD
FRONT ALONG WITH IT. SHEAR PROFILES SHOULD ACTUALLY INCREASE IN
MAGNITUDE GIVEN MID LEVEL SPEED MAX TIED TO WAVE. SHEAR VECTORS ARE
LINING UP NEARLY PARALLEL WITH EXPECTED FRONTAL/CONVECTIVE
LINE...SUPPORTING MORE OF A LINEAR STORM MODE. WIND
FIELDS...PREDICTED DOWNDRAFT CAPE AND LAYER THETA-E DIFFERENCES
APPROACHING 30 ALL SUGGEST SEVERE WIND POTENTIAL AS LINE RACES INTO
EASTERN NEBRASKA. SEVERAL MESOSCALE HI-RES MODELS ARE OFFERING
VARIED OPINIONS AROUND THIS LINE OF THINKING...SO WILL HIT EVENING
THUNDER CHANCES PRETTY HARD. EXPECT STORMS TO SLOWLY DIE OFF LATER
THIS EVENING AND OVERNIGHT AS THEY APPROACH INTERSTATE 80 AND
BEYOND...HOWEVER SEVERE THREAT APPEARS TO LINGER FOR SOME TIME AFTER
DARK.
BY MONDAY MORNING LINGERING STORMS SHOULD BE EXITING OUR
SOUTHEAST CWA. HOWEVER WEAK IMPULSE IN MID LEVEL FLOW COULD TAP
WANING INSTABILITY IN THE MID AFTERNOON TO PRODUCE A STORM OR TWO
IN SOUTHWEST IOWA. THEN NORTHERLY SURFACE FLOW UNDER HIGH PRESSURE
WILL FORETELL A RELATIVELY DRY PERIOD OVER THE NEXT COUPLE OF
DAYS.
HIGHS BOTH TUESDAY AND WEDNESDAY WILL GRADUALLY INCREASE INTO THE
LOWER AND MIDDLE 80S UNDER PLENTY OF SUNSHINE. AND DEW POINTS SHOULD
BE LOWER ON TUESDAY BEFORE BEGINNING TO RETURN WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
OUR RELATIVELY QUIET WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH
THE REST OF THE WEEK. MID LEVEL HIGH PRESSURE RIDGE IS FORECAST BY
BOTH ECMWF AND GFS TO BUILD FROM THE SOUTHERN PLAINS INTO THE
NORTHERN ROCKIES...AND EXPAND A BIT TO THE EAST. THIS WILL TAKE MAIN
STORM TRACK NORTH AND EAST OF OUR AREA...AND ALLOW FOR WARMER
TEMPERATURES BOTH AT THE SURFACE AND ALOFT. WILL MAINTAIN OUR DRY
FORECAST UNTIL MAYBE SATURDAY NIGHT OR SUNDAY WHEN RIDGE IS FORECAST
TO BEGIN TO BREAK DOWN. HIGHS MAINLY IN THE UPPER 80S AND LOWER 90S
SHOULD PREVAIL.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1223 AM CDT MON AUG 10 2015
THUNDERSTORMS AFFECTING KOMA WERE MOVING AWAY AND WILL
EAST/SOUTHEAST OF THE TAF SITE BEFORE 06Z. OTHERWISE...THERE WILL
BE A CHANCE OF ADDITIONAL THUNDERSTORMS IN THE AREA...BUT NOT
CONFIDENT ENOUGH THAT STORMS WOULD DIRECTLY IMPACT ANY TAF
LOCATIONS. OCCASIONAL MVFR CONDITIONS AT ALL THREE TAF SITES
THROUGH ABOUT 13-15Z...THEN VFR AFTER THAT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
133 AM EDT MON AUG 10 2015
.SYNOPSIS...
DRY WEATHER AND SEASONAL TEMPERATURES WILL CONTINUE TONIGHT AND
MONDAY AS HIGH PRESSURE REMAINS OVER THE REGION, BUT CONDITIONS TAKE
A TURN FOR THE WORSE MONDAY NIGHT THROUGH TUESDAY NIGHT AS LOW
PRESSURE TRACKS OVER THE REGION. A WIDESPREAD RAIN EVENT IS EXPECTED
WITH STORM TOTALS OF A HALF TO ONE AND A HALF INCHES OF RAIN.
CHANCES FOR SHOWERS CONTINUE INTO WEDNESDAY BEFORE DRIER CONDITIONS
RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 116 AM EDT MONDAY...UPDATED TO CAPTURE LATEST TEMP/DWPT/WIND
AND SKY CONDITIONS. SOME PATCHY FOG ALREADY DEVELOPING WILL
CONTINUE TO SPREAD IN AREAL COVERAGE ACRS THE DEEPER PROTECTED
RIVER VALLEYS WITH TEMPS FALLING BACK INTO THE U40S DACKS TO L/M
50S SLV/NEK/CENTRAL VT TO NEAR 60F CPV.
MINOR ADJUSTMENTS TO SKY COVER AND MINIMUM TEMPERATURES (REALLY
AT THE NOISE LEVEL) TO COVER CURRENT OBSERVATIONAL TRENDS. A FEW
SPOTS IN THE ST LAWRENCE VALLEY WERE ALREADY WITHIN A DEGREE OF
FORECAST MINIMUM TEMPERATURES SO I DID LOWER THOSE VALUES BY A FEW
DEGREES. ALSO INCORPORATED LATEST RAP UPPER LEVEL RH PROGS INTO
THE CLOUD FORECAST OVERNIGHT, SHOWING AT LEAST SOME CI/CS
OVERSPREADING THE REGION FROM WEST TO EAST AFTER MIDNIGHT, THOUGH
BY AND LARGE CLEAR TO PARTLY CLOUDY SKIES WILL STILL BE THE
PREVAILING RULE. HAVE A GREAT NIGHT.
PRIOR DISCUSSION FROM 738 PM EDT SUNDAY... MINOR ADJUSTMENTS TO
FORECAST AS OF 700 PM, MAINLY TO KEEP 10-20% POPS ACROSS NC/NE VT
THROUGH 9 PM OR SO TO ACCOUNT FOR CURRENT WIDELY SCT SHOWER
ACTIVITY WHICH HAS SURPRISINGLY INCREASED IN AREAL COVERAGE OVER
THE PAST HOUR OR SO. THIS ACTIVITY IS DEVELOPING IN WEAKLY
CONVERGENT LOW TO MID LEVEL FLOW ALONG A DIFFUSE SFC
TROUGH/BACKDOOR FRONT ORIENTED NNW TO SSE ACROSS SOUTHERN QUEBEC
INTO NORTHEASTERN VT AND SOUTHWARD INTO CENTRAL NH WHERE IT
BECOMES DIFFICULT TO IDENTIFY. GIVEN THIS ACTIVITY AND ALLOWING
FOR SCATTERED AREAS OF WET GROUND TO FOSTER ENHANCED SFC MOISTURE
FLUXES OVERNIGHT I ALSO INTRODUCED SLIGHTLY HIGHER COVERAGE OF
BR/FG ACROSS THIS AREA WHICH LATEST BTV4/BTV6 KM OUTPUT SHOWS
QUITE NICELY. OTHERWISE INHERITED FORECAST REMAINS IN GOOD SHAPE
SHOWING MAINLY CLR/PTLY CLOUDY SKIES OVERNIGHT (OUTSIDE THE FOG)
AS TEMPERATURES BOTTOM OUT IN THE 50S TO AROUND 60 BY SUNRISE
MONDAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 355 PM EDT SUNDAY...MONDAY WILL BE OUR LAST DAY OF THIS
NICE STRETCH OF WEATHER AS ALL AVAILABLE GUIDANCE IS IN GOOD
AGREEMENT SHOWING THE BEST LOW/MID LEVEL MOISTURE AND FORCING
ASSOCIATED WITH OUR NEXT SYSTEM IS WEST OF THE AREA THROUGH 00Z
TUESDAY. AFTER MORNING FOG BURNS OFF WE`LL SEE INCREASING CLOUDS
FROM THE WEST WHICH MAY TEMPER AFTERNOON TEMPS, BUT PROGGED 850MB
TEMPS OF 12-14C WILL SUPPORT HIGHS IN THE UPPER 70S MOUNTAINS TO
LOW/MID 80S IN THE VALLEYS.
AS MENTIONED, ALL GUIDANCE IS IN GOOD AGREEMENT HANDLING A DEEPENING
MID/UPPER TROUGH ACROSS THE GREAT LAKES AND SURFACE LOW TRACKING
FROM THE OHIO VALLEY MONDAY NIGHT AND ACROSS THE BTV CWA TUESDAY.
00Z GFS CAME AROUND TO THE NAM/ECMWF/CMC SLOWER TIMING AND THE 12Z
RUNS SLOWED THE ARRIVAL OF DEEP LAYER MOISTURE EVEN FURTHER TO NOW
AFTER MIDNIGHT. HEAVIEST QPF AXIS CONTINUES TO POINT TOWARDS
NORTHERN NEW YORK WHERE 1-1.5" STORM TOTAL IS EXPECTED THROUGH
TUESDAY, WHILE POINTS EASTWARD WILL BE GENERALLY LESS THAN AN INCH
WITH SOME DOWNSLOPING EFFECTS EXPECTED ACROSS PORTIONS OF THE
GREEN MOUNTAINS ASSOCIATED WITH A LOW LEVEL SOUTHEASTERLY JET OF
40-50 KNOTS IMPACTING THE AREA TUESDAY. SOUNDINGS CONTINUE TO SHOW
THESE RIDGETOP WINDS ARE ABOVE THE INVERSION LEVEL AROUND 2000
FT, SO NOT EXPECTING STRONG GUSTS REACHING THE SURFACE, BUT 25-35
MPH SEEM REASONABLE ALONG THE FAVORED LOCALES OF THE WESTERN
SLOPES FROM RUTLAND TO UNDERHILL. CAN`T RULE OUT A FEW RUMBLES OF
THUNDER THROUGH THE EVENT EITHER WITH MODELS SHOWING SOME SLIGHT
ELEVATED INSTABILITY BUT AREAL COVERAGE SHOULD BE PRETTY LIMITED.
TUESDAY NIGHT THE SURFACE LOW TRACKS EAST OF THE REGION WITH A MID-
LEVEL DRY SLOT SHIFTING OVER THE REGION. PRECIP WILL END FROM WEST
TO EAST BY MIDNIGHT, WITH CONDITIONS GENERALLY DRY THROUGH SUNRISE.
MID-LEVEL HEIGHTS/THICKNESS DON`T FALL MUCH SO IT WILL BE A MILD
NIGHT UNDER PLENTY OF CLOUD COVER WITH LOWS IN THE UPPER 50S TO MID
60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 259 PM EDT SUNDAY...UNSETTLED WEATHER CONTINUES THROUGH THE
EXTENDED PERIOD WITH UPPER TROUGH REMAINING IN PLACE OVER THE
NORTHEAST AND PASSAGE OF ANOTHER SURFACE FRONT ON FRIDAY.
STARTING 12Z WEDNESDAY...SURFACE FRONT WILL HAVE PASSED ON TO THE
EAST WITH A WESTERLY LOW LEVEL FLOW. 500 MB TROUGH LAGGING BEHIND
SURFACE FEATURE AND WILL BE SETTLING IN ON WEDNESDAY. COMBINATION
OF COLD POOL ALOFT, LOW LEVEL UPSLOPE FLOW, AND MOISTURE TRAPPED
IN THE LOW LEVELS WILL RESULT IN MAINLY DAYTIME SHOWERS IN THE
RESULTING INSTABILITY AND LIFT.
IF ANY TIME WILL BE QUIET IT WOULD BE THURSDAY WHEN THE REGION IS
BETWEEN SYSTEMS. UPPER LOW GETS KICKED OUT AS NEXT LOW APPROACHES,
AND AN AREA OF SHORTWAVE RIDGING PASSES OVER. WESTERLY UPSLOPE LOW
LEVEL FLOW TURNS MORE SOUTHERLY BY END OF DAY, AND A BAND OF DRIER
AIR MOVES IN TO MINIMIZE CHANCES FOR RAIN. FRIDAY HAS RAIN CHANCES
AGAIN WHEN COLD FRONT MOVES THROUGH AT THE SURFACE AGAIN AND UPPER
SHORTWAVE THAT MOVED DOWN IN THE NORTHWEST FLOW DROPS INTO THE
BASE OF THE MEAN TROUGH. CHANCE FOR SHOWERS INTO SATURDAY WITH
SAME POST FRONTAL SCENARIO OF INSTABILITY DRIVEN BY COLD POOL
ALOFT AND LIFT FROM LOW LEVEL UPSLOPE FLOW.
MENTIONED THUNDER ON WEDNESDAY AND FRIDAY AS CAPE, MEAGER THOUGH
IT IS, INCREASES TO 250-500 J/KG AND COULD GET ENOUGH VERTICAL
DEVELOPMENT FOR LIGHTNING. NOT MUCH CHANGE IN TEMPERATURES
THROUGHOUT, WE NEVER GET MUCH CHANCE TO WARM APPRECIABLY, AND THE
AIR BEHIND THE FRONTS IS NOT PARTICULARLY COOL EITHER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 06Z TUESDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR OVERNIGHT INTO EARLY MONDAY MORNING AT
MPV/SLK/MSS. SCT CUMULUS FIELD WILL GRADUALLY DIMINISH OVERNIGHT.
THIS CLEARING WILL ALLOW FOR THE FORMATION OF FOG/BR AT SLK/MPV/MSS.
DENSEST AND MOST PERSISTENT FOG EXPECTED AT MPV BETWEEN 07Z AND 13Z.
AFTER 12-13Z MONDAY MORNING EXPECTING BOTH SCATTERED HIGH CIRRUS TO
FILTER ACROSS AS WELL AS THE DEVELOPMENT OF ADDITIONAL CUMULUS
CLOUDS BY AFTERNOON. CLOUD COVERAGE INCREASES AREA-WIDE MONDAY
EVENING. A FEW RAIN SHOWERS ARE POSSIBLE AT SLK AFTER 21Z.
COVERAGE OF RAIN SHOWERS INCREASES ACROSS NORTHERN NY BETWEEN
00-06Z TUESDAY...AFFECTING SLK/MSS/PBG. LIGHT AND LOCALLY
VARIABLE WINDS (EXCEPT SE DRAINAGE AT RUT) BECOME SOUTHERLY FROM
5-8 KNOTS ON MONDAY.
OUTLOOK 06Z TUESDAY THROUGH FRIDAY...
06Z TUE - 00Z WED...DETERIORATING CONDITIONS LIKELY (MVFR
POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND STRATUS.
00Z WED - 00Z THU...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS.
00Z THU - 00Z FRI...VFR WITH A FEW SCATTERED RAIN SHOWERS STILL
POSSIBLE.
00Z FRI ONWARD...VFR WITH PERIODS MVFR IN SCATTERED SHOWERS ALONG
A COLD FRONT...MAINLY AFTER 18Z.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...JMG/TABER
SHORT TERM...LAHIFF
LONG TERM...HANSON
AVIATION...RJS/MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
118 AM EDT MON AUG 10 2015
.SYNOPSIS...
DRY WEATHER AND SEASONAL TEMPERATURES WILL CONTINUE TONIGHT AND
MONDAY AS HIGH PRESSURE REMAINS OVER THE REGION, BUT CONDITIONS TAKE
A TURN FOR THE WORSE MONDAY NIGHT THROUGH TUESDAY NIGHT AS LOW
PRESSURE TRACKS OVER THE REGION. A WIDESPREAD RAIN EVENT IS EXPECTED
WITH STORM TOTALS OF A HALF TO ONE AND A HALF INCHES OF RAIN.
CHANCES FOR SHOWERS CONTINUE INTO WEDNESDAY BEFORE DRIER CONDITIONS
RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 116 AM EDT MONDAY...UPDATED TO CAPTURE LATEST TEMP/DWPT/WIND
AND SKY CONDITIONS. SOME PATCHY FOG ALREADY DEVELOPING WILL
CONTINUE TO SPREAD IN AREAL COVERAGE ACRS THE DEEPER PROTECTED
RIVER VALLEYS WITH TEMPS FALLING BACK INTO THE U40S DACKS TO L/M
50S SLV/NEK/CENTRAL VT TO NEAR 60F CPV.
MINOR ADJUSTMENTS TO SKY COVER AND MINIMUM TEMPERATURES (REALLY
AT THE NOISE LEVEL) TO COVER CURRENT OBSERVATIONAL TRENDS. A FEW
SPOTS IN THE ST LAWRENCE VALLEY WERE ALREADY WITHIN A DEGREE OF
FORECAST MINIMUM TEMPERATURES SO I DID LOWER THOSE VALUES BY A FEW
DEGREES. ALSO INCORPORATED LATEST RAP UPPER LEVEL RH PROGS INTO
THE CLOUD FORECAST OVERNIGHT, SHOWING AT LEAST SOME CI/CS
OVERSPREADING THE REGION FROM WEST TO EAST AFTER MIDNIGHT, THOUGH
BY AND LARGE CLEAR TO PARTLY CLOUDY SKIES WILL STILL BE THE
PREVAILING RULE. HAVE A GREAT NIGHT.
PRIOR DISCUSSION FROM 738 PM EDT SUNDAY... MINOR ADJUSTMENTS TO
FORECAST AS OF 700 PM, MAINLY TO KEEP 10-20% POPS ACROSS NC/NE VT
THROUGH 9 PM OR SO TO ACCOUNT FOR CURRENT WIDELY SCT SHOWER
ACTIVITY WHICH HAS SURPRISINGLY INCREASED IN AREAL COVERAGE OVER
THE PAST HOUR OR SO. THIS ACTIVITY IS DEVELOPING IN WEAKLY
CONVERGENT LOW TO MID LEVEL FLOW ALONG A DIFFUSE SFC
TROUGH/BACKDOOR FRONT ORIENTED NNW TO SSE ACROSS SOUTHERN QUEBEC
INTO NORTHEASTERN VT AND SOUTHWARD INTO CENTRAL NH WHERE IT
BECOMES DIFFICULT TO IDENTIFY. GIVEN THIS ACTIVITY AND ALLOWING
FOR SCATTERED AREAS OF WET GROUND TO FOSTER ENHANCED SFC MOISTURE
FLUXES OVERNIGHT I ALSO INTRODUCED SLIGHTLY HIGHER COVERAGE OF
BR/FG ACROSS THIS AREA WHICH LATEST BTV4/BTV6 KM OUTPUT SHOWS
QUITE NICELY. OTHERWISE INHERITED FORECAST REMAINS IN GOOD SHAPE
SHOWING MAINLY CLR/PTLY CLOUDY SKIES OVERNIGHT (OUTSIDE THE FOG)
AS TEMPERATURES BOTTOM OUT IN THE 50S TO AROUND 60 BY SUNRISE
MONDAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 355 PM EDT SUNDAY...MONDAY WILL BE OUR LAST DAY OF THIS
NICE STRETCH OF WEATHER AS ALL AVAILABLE GUIDANCE IS IN GOOD
AGREEMENT SHOWING THE BEST LOW/MID LEVEL MOISTURE AND FORCING
ASSOCIATED WITH OUR NEXT SYSTEM IS WEST OF THE AREA THROUGH 00Z
TUESDAY. AFTER MORNING FOG BURNS OFF WE`LL SEE INCREASING CLOUDS
FROM THE WEST WHICH MAY TEMPER AFTERNOON TEMPS, BUT PROGGED 850MB
TEMPS OF 12-14C WILL SUPPORT HIGHS IN THE UPPER 70S MOUNTAINS TO
LOW/MID 80S IN THE VALLEYS.
AS MENTIONED, ALL GUIDANCE IS IN GOOD AGREEMENT HANDLING A DEEPENING
MID/UPPER TROUGH ACROSS THE GREAT LAKES AND SURFACE LOW TRACKING
FROM THE OHIO VALLEY MONDAY NIGHT AND ACROSS THE BTV CWA TUESDAY.
00Z GFS CAME AROUND TO THE NAM/ECMWF/CMC SLOWER TIMING AND THE 12Z
RUNS SLOWED THE ARRIVAL OF DEEP LAYER MOISTURE EVEN FURTHER TO NOW
AFTER MIDNIGHT. HEAVIEST QPF AXIS CONTINUES TO POINT TOWARDS
NORTHERN NEW YORK WHERE 1-1.5" STORM TOTAL IS EXPECTED THROUGH
TUESDAY, WHILE POINTS EASTWARD WILL BE GENERALLY LESS THAN AN INCH
WITH SOME DOWNSLOPING EFFECTS EXPECTED ACROSS PORTIONS OF THE
GREEN MOUNTAINS ASSOCIATED WITH A LOW LEVEL SOUTHEASTERLY JET OF
40-50 KNOTS IMPACTING THE AREA TUESDAY. SOUNDINGS CONTINUE TO SHOW
THESE RIDGETOP WINDS ARE ABOVE THE INVERSION LEVEL AROUND 2000
FT, SO NOT EXPECTING STRONG GUSTS REACHING THE SURFACE, BUT 25-35
MPH SEEM REASONABLE ALONG THE FAVORED LOCALES OF THE WESTERN
SLOPES FROM RUTLAND TO UNDERHILL. CAN`T RULE OUT A FEW RUMBLES OF
THUNDER THROUGH THE EVENT EITHER WITH MODELS SHOWING SOME SLIGHT
ELEVATED INSTABILITY BUT AREAL COVERAGE SHOULD BE PRETTY LIMITED.
TUESDAY NIGHT THE SURFACE LOW TRACKS EAST OF THE REGION WITH A MID-
LEVEL DRY SLOT SHIFTING OVER THE REGION. PRECIP WILL END FROM WEST
TO EAST BY MIDNIGHT, WITH CONDITIONS GENERALLY DRY THROUGH SUNRISE.
MID-LEVEL HEIGHTS/THICKNESS DON`T FALL MUCH SO IT WILL BE A MILD
NIGHT UNDER PLENTY OF CLOUD COVER WITH LOWS IN THE UPPER 50S TO MID
60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 259 PM EDT SUNDAY...UNSETTLED WEATHER CONTINUES THROUGH THE
EXTENDED PERIOD WITH UPPER TROUGH REMAINING IN PLACE OVER THE
NORTHEAST AND PASSAGE OF ANOTHER SURFACE FRONT ON FRIDAY.
STARTING 12Z WEDNESDAY...SURFACE FRONT WILL HAVE PASSED ON TO THE
EAST WITH A WESTERLY LOW LEVEL FLOW. 500 MB TROUGH LAGGING BEHIND
SURFACE FEATURE AND WILL BE SETTLING IN ON WEDNESDAY. COMBINATION
OF COLD POOL ALOFT, LOW LEVEL UPSLOPE FLOW, AND MOISTURE TRAPPED
IN THE LOW LEVELS WILL RESULT IN MAINLY DAYTIME SHOWERS IN THE
RESULTING INSTABILITY AND LIFT.
IF ANY TIME WILL BE QUIET IT WOULD BE THURSDAY WHEN THE REGION IS
BETWEEN SYSTEMS. UPPER LOW GETS KICKED OUT AS NEXT LOW APPROACHES,
AND AN AREA OF SHORTWAVE RIDGING PASSES OVER. WESTERLY UPSLOPE LOW
LEVEL FLOW TURNS MORE SOUTHERLY BY END OF DAY, AND A BAND OF DRIER
AIR MOVES IN TO MINIMIZE CHANCES FOR RAIN. FRIDAY HAS RAIN CHANCES
AGAIN WHEN COLD FRONT MOVES THROUGH AT THE SURFACE AGAIN AND UPPER
SHORTWAVE THAT MOVED DOWN IN THE NORTHWEST FLOW DROPS INTO THE
BASE OF THE MEAN TROUGH. CHANCE FOR SHOWERS INTO SATURDAY WITH
SAME POST FRONTAL SCENARIO OF INSTABILITY DRIVEN BY COLD POOL
ALOFT AND LIFT FROM LOW LEVEL UPSLOPE FLOW.
MENTIONED THUNDER ON WEDNESDAY AND FRIDAY AS CAPE, MEAGER THOUGH
IT IS, INCREASES TO 250-500 J/KG AND COULD GET ENOUGH VERTICAL
DEVELOPMENT FOR LIGHTNING. NOT MUCH CHANGE IN TEMPERATURES
THROUGHOUT, WE NEVER GET MUCH CHANCE TO WARM APPRECIABLY, AND THE
AIR BEHIND THE FRONTS IS NOT PARTICULARLY COOL EITHER.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR AGAIN LATE TONIGHT/EARLY MONDAY MORNING AT
MPV/SLK/MSS. SCT CUMULUS FIELD FROM THIS AFTERNOON AND EVENING
WILL GRADUALLY DIMINISH THROUGH THE REMAINDER OF THE EVENING AND
OVERNIGHT HOURS. THIS CLEARING WILL ALLOW FOR THE FORMATION OF
FOG/BR AT SLK/MPV/MSS. DENSEST AND MOST PERSISTENT FOG EXPECTED AT
MPV BETWEEN 07Z AND 13Z. AFTER 12-13Z MONDAY MORNING EXPECTING
BOTH SCATTERED HIGH CIRRUS TO FILTER ACROSS AS WELL AS THE
DEVELOPMENT OF ADDITIONAL CUMULUS CLOUDS BY AFTERNOON. A FEW
SCATTERED RAIN SHOWERS ARE EVEN POSSIBLE AT SLK AFTER 21Z. LIGHT
AND LOCALLY VARIABLE WINDS (EXCEPT SE DRAINAGE AT RUT) BECOME
SOUTHERLY FROM 5-8 KNOTS ON MONDAY.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR WITH PERIODS OF MVFR IN
LINGERING SCATTERED SHOWERS.
00Z THURSDAY-00Z FRIDAY...VFR WITH A FEW SCATTERED RAIN SHOWERS
STILL POSSIBLE.
00Z FRIDAY ONWARD...VFR WITH PERIODS MVFR IN SCATTERED
SHOWERS ALONG A COLD FRONT...MAINLY AFTER 18Z.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...JMG/TABER
SHORT TERM...LAHIFF
LONG TERM...HANSON
AVIATION...MUCCILLI
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
500 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY WISE/BEST...NOT TO RUN WITH ANY
ONE MODEL SOLUTION. WITH ADJUSTMENTS BEING MADE DURING THE COURSE OF
THE DAY AND EVENING BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
THIS EVENING INTO WV. HOWEVER...AS OF THIS EARLY HOUR...COULD NOT
HIGHLIGHT A SPECIFIC THREAT AREA. WOULD NOT BE SURPRISED IF SPC
UPDATES ON DAY 1...INCLUDED SOME SLIGHT RISK AREAS...AS THIS WHOLE
SYSTEM EVOLVES/DEVELOPS.
OVERALL NOT TOO EXCITED WITH THE THIN CAPE AND RELATIVELY WEAK FLOW
AS DISCUSSED. MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
ONE MID LEVEL DISTURBANCE MOVING THROUGH SRN WV AT 06Z WITH
A FEW LIGHT SHOWERS. WIDESPREAD CLOUDS AT 4 TO 10 THSD FT SHOULD
LIMITED COVERAGE OF ANY THICKER FOG THIS MORNING. ANY BREAKS COULD
BRING BRIEF IFR IN WV MOUNTAIN VALLEYS SUCH AS EKN.
CONVECTION DROPPING SE THROUGH WRN KY TOWARD TN BUT A FEW SHOWERS
MAY FORM FURTHER E AND AFFECT SW VA THIS MORNING.
WILL HAVE MOSTLY 3 TO 5 THSD FT SCT TO BKN AGL TODAY WITH LAYERS
ABOVE. COULD NOT TIME ANY DEFINITE ROUNDS OF CONVECTION THIS
AFTERNOON SO HAVE VCNTY THUNDERSTORM IN MOST TAF SITES. TRIED TO
INCREASE COVERAGE IN SE OHIO AFTER 20Z...THEN MOVE INTO WV FOR 00Z
TO 06Z. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT BKN TO OVC AND
VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
WITH WEAK LOW PRESSURE DEVELOPING IN UPPER OHIO VALLEY
TODAY...HAVE ITS ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY. CEILINGS DETERIORATING FURTHER BUT MOSTLY
AFTER 06Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING OF ROUNDS OF CONVECTION THIS
AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/10/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H M M H H H H H H H H
HTS CONSISTENCY H H M M H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M L L L M M H H H H H
PKB CONSISTENCY H H M M H H H H H H H H
CKB CONSISTENCY H H M M M H H H H H H H
AFTER 06Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING LOW CEILINGS AND SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
351 AM EDT MON AUG 10 2015
.SYNOPSIS...
RETURN FLOW OFF THE GULF OF MEXICO WILL BRING IN MOISTURE TODAY
AHEAD OF THE NEXT COLD FRONT. EXPECT SHOWERS AND THUNDERSTORMS AHEAD
OF THE FRONT UNTIL THIS FRONT PASSES LATE TUESDAY. COOLER AND DRIER
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER FROM WEDNESDAY INTO
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOME LINGERING -SHRA/TSTMS ACROSS THE NC PIEDMONT AND EXTREME SRN
ZONES THIS MORNING. THIS ACTIVITY IS REMAINING FAIRLY STATIONARY
ALONG THE EDGE OF A ERN SFC HIGH WITH MOIST W/LY LIFT. SOME
ADDITIONAL CELLS COULD FILL IN THROUGH DAYBREAK...BUT OVERALL THE
ACTIVITY WILL REMAIN SHALLOW WITH ECHO TOPS AROUND 20 KFT. ENUF CELL
MOVEMENT IS EVIDENT TO HAVE MUCH OF A HYDRO CONCERN...BUT WILL
MONITOR FOR ANY POSSIBLE ISSUES.
THE FCST FOR THIS AFTERNOON IS A LITTLE TRICKY AS CLOUD COVER ACROSS
THE ERN ZONES SHOULD INHIBIT DEEP INSTABILITY UNTIL LATE DAY. PLAN
VIEW SBCAPE SHOWS THE BEST POTENTIAL ACROSS THE UPPER SAVANNAH
VALLEY AND NORTH ACROSS THE BLUE RIDGE AND MOST OF THE UPSTATE.
THERE IS NOT A LOT OF DYNAMIC FORCING TO BE HAD. THE H3 FLOW DOES
BECOME DIFFLUENT AND THIS WILL HELP BRING IN A PRE/FRONTAL
TROF...BUT NO WELL DEFINED NOR ACUTE S/W ENERGY SHOULD BE AVAILABLE.
EXCEPT PERHAPS ACROSS NE GA AND THE FAR WRN UPSTATE PER SOME HIRES
MOD SOLNS. SO...EXPECT ISOL TSTM ACTIVITY TO BEGIN ACROSS THE MTNS
AND ARND 17Z OR SO...THEN SLOWLY FILL IN TO THE EAST THROUGHOUT THE
AFTERNOON/EVENING. POPS HAVE BEEN BUMPED DOWN ACROSS THE NC PIEDMONT AND
SE/RN UPSTATE DUE TO UNCERTAINTY WITH INSTABILITY AND PROGRESSION OF
THE PF/TROF. THE STRONGER STORMS WILL DEVELOP ACROSS NE GA ALONG
THE SC BORDER AND THE SRN BLUE RIDGE. BULK SHEAR IS NOT THAT
IMPRESSIVE...ON THE ORDER OF 20 KTS...BUT AREAS OF GOOD DIFF HEATING
COULD SUPPORT ISOL SEVERE CONVECTION.
THE BETTER ULVL ENERGY AND A S/W TROF MOVES INTO THE NC MTNS AFT 00Z
WHICH WILL THEN CROSS THE FA THROUGH THE OVERNIGHT. CROSS SECTIONS
DEPICT AROUND 150 J/KG OF ELCAPE...SO THUNDER MENTION WILL REMAIN
ALL ZONES WHILE POPS DROP TO THE LOWER CHANCE RANGE BY DAYBREAK. THE
UPPER PATTERN BECOMES MORE CYCLONIC AND DIFFLUENT OVERNIGHT AS
WELL...SO STRONG AND HIGH RAINFALL RATE STORMS ARE POSSIBLE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 315 AM MON...SFC COLD FRONT IS PROGGED TO PUSH THRU THE AREA
TUE ENHANCING FORCING IN AN OTHERWISE FAVORABLE ENVIRONMENT FOR DEEP
CONVECTION. FRONTAL TROUGH AXIS WILL CROSS THE MTNS IN THE MRNG AND
MODEST COVERAGE OF SHRA/TSRA IS EXPECTED THEN. DESTABILIZATION WILL
OCCUR PRIOR TO THE FRONT ITSELF. HIGHER RES GUIDANCE SUGGESTS THE
MRNG ACTIVITY WILL DISSIPATE AND/OR PROPAGATE OUT OF THE AREA BEFORE
A SECOND ROUND DEVELOPS OVER THE MTNS WITH THE FRONT.
THE PIEDMONT ACTIVITY...PARTICULAR THAT BEGINNING EARLIER IN THE
DAY...POSES A HEAVY RAIN THREAT DUE TO PWAT VALUES AT OR ABOVE THE
90TH PERCENTILE...BUT AS DRIER AIR WORKS IN ALOFT BEHIND THE TROUGH
PWATS DIP BACK TO VALUES NEAR CLIMATOLOGICAL MEDIAN. STORMS SHOULD
MOVE PRETTY QUICKLY GIVEN THE BRISK FLOW ALOFT...AND NO WELL-DEFINED
LLJ IS SEEN ON PROFILES. SO ANY HYDRO CONCERNS APPEAR LIKELY TO
REMAIN LOCALIZED ESPECIALLY IN LIGHT OF DRY SOIL CONDITIONS OVERALL.
INSTABILITY IS NOT THE GREATEST BUT SHEAR IS APPRECIABLE. 0-6KM BULK
VALUES PEAK AT 30-35 KT WHICH WILL ALLOW AT LEAST LOOSE ORGANIZATION.
SO AT THE OTHER END OF THE SPECTRUM...AS DRYING OCCURS ALOFT THE
LATER ROUND OF STORMS WILL BE CAPABLE OF DAMAGING WINDS ON A SOMEWHAT
LARGER SCALE THAN WE OFTEN SEE THIS TIME OF YEAR. SPC DAY 2 OUTLOOK
PAINTS OUR PIEDMONT IN A MARGINAL RISK AREA BUT THERE APPEARS TO BE
SOME RISK THROUGHOUT THE AREA...UNLESS THE FRONT ARRIVES EARLIER THAN
ANTICIPATED.
THE FRONT BRINGS DRIER AND COOLER AIR ACRS THE AREA TUE NIGHT AS POPS
DROP TO UNMENTIONABLY LOW VALUES. DIURNAL CONVECTION IS NOT EXPECTED
WED AND DEWPOINTS WILL BE COMFORTABLY LOW FOR MID-AUGUST. MINS THU
MORNING WILL BE SLIGHTLY BELOW CLIMO ALSO.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 AM TUE...HIGHLY AMPLIFIED UPPER PATTERN FEATURING SHARP ERN
TROUGH AND WRN RIDGE EXPECTED THU...BEGINNING TO BREAK DOWN BY LATE
FRI AS THE TROUGH LIFTS AND RIDGE BEGINS TO SHEAR. AT THE SFC THIS
MEANS BROAD SFC HIGH PRESSURE SPREADS EAST. A PORTION OF THE
RETREATING TROUGH SHEARS OFF OVER THE CENTRAL GULF COAST SATURDAY
POSSIBLY LEADING TO THE DEVELOPMENT OF A SFC LOW ALONG STALLED FRONT.
THESE FEATURES INITIATE MOIST RETURN FLOW FRI WHICH MAY CONTINUE INTO
THE WEEKEND PER GFS SOLUTION. THIS WOULD PROBABLY ALLOW SOME DIURNAL
CONVECTION TO RESUME AT LEAST OVER THE BLUE RIDGE. THE 09/12Z EC AND
TO SOME EXTENT THE 10/00Z GEM DEPICT A SECOND SFC HIGH MOVING THRU
THE OHIO VALLEY WHICH LEADS IT TO KEEP A DRIER AND MORE NORTHERLY
FLOW INTO OUR AREA. MAINLY SCHC POPS ARE MENTIONED EACH DAY OF THE
PERIOD...AND MAINLY NEAR THE BLUE RIDGE. TEMPS WILL START OFF A FEW
DEGREES BELOW CLIMO IN THE CONTINENTAL AIRMASS...MODERATING TO NEAR
CLIMO BY SUNDAY NIGHT AS IT MODIFIES.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT...CONTINUED IDEA OF PREVIOUS TAF WITH BRINGING IN LOW SCT
STCU BEFORE SUNRISE. NOT ENUF MOISTURE RESPONSE ON RAP SOUNDINGS TO
GO FOR A CIG ATTM. STILL EXPECT TSTMS THIS AFTERNOON...BUT MAY HAVE
TO PUSH BACK TIMING ON THE 12Z TAF. MODEL PROGRESSION OF MUCAPE IS
IS SLOW TO MOVE EAST AS LLVL CLOUD COVER COULD PERSIST THROUGH NOON
OR SO. IN FACT THE PREFRONTAL DEEP CONVECTION MAY REMAIN WEST OF
THE TERMINAL UNTIL LATE IN THE PERIOD.
ELSEWHERE...SOME MVFR/IFR IS POSSIBLE AT KAVL AND KHKY THIS MORNING
AS TTD/S ARE RUNNING 1-2 F. POSSIBLE VSBY CONCERNS ACROSS THE SC
SITES AS WELL ARND DAYBREAK. CONVECTIVE ACTIVITY WILL AFFECT KAVL
ARND 18Z AS PREFRONTAL TROF DEVELOPS AND FORCING SPREADS EAST
INDUCING THUNDER AT THE OTHER TERMINALS 1-3 HRS LATER. PRECIP AND
THUNDER WILL PERSIST NEAR ALL TERMINALS LATE IN THE TAF PERIOD WITH
SOME VSBY/CIGS ISSUES PROBABLE.
OUTLOOK...HEAVY RAINFALL MON AFTN/EVENING ASSOCIATED WITH THE COLD
FRONT/SHORTWAVE COULD LEAD TO SOME MORNING RESTRICTIONS TUE.
DRIER/VFR CONDITIONS RETURN BY TUE EVENING...AND SHOULD PREVAIL THRU
AT LEAST THURSDAY.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 83% HIGH 89% HIGH 100% HIGH 93%
KAVL HIGH 84% HIGH 88% HIGH 96% HIGH 83%
KHKY HIGH 86% HIGH 82% HIGH 100% HIGH 97%
KGMU HIGH 91% MED 76% HIGH 90% HIGH 93%
KAND HIGH 87% HIGH 93% HIGH 100% HIGH 93%
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_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...SBK
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
134 AM EDT MON AUG 10 2015
.SYNOPSIS...
A SOUTH TO SOUTHWEST WIND FLOW WILL DEVELOP TONIGHT AND CONTINUE INTO
MONDAY BRINGING IN MOISTURE OFF THE GULF AHEAD OF THE NEXT COLD
FRONT. EXPECT SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT UNTIL
THIS FRONT PASSES LATE TUESDAY. COOLER AND DRIER HIGH PRESSURE WILL
BE IN CONTROL OF OUR WEATHER FOR THE LAST HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 130 AM EDT MONDAY...NO SIGFNT CHANGES NEEDED TO THE GOING
FCST. CLOUD COVER WAS UPDATED TO ACCOUNT FOR THICK CI ADV ACROSS THE
NRN ZONES. MADE SOME MINOR TWEAKS TO T/TD GRIDS ACROSS THE UPSTATE.
AS OF 1030 PM EDT SUNDAY...ONLY ISOLATED CONVECTION STILL OUT THERE
THIS EVENING BUT RAPIDLY DISSIPATING. MOST GRIDS LOOK GOOD WITH ONLY
MINOR CHANGES BASED ON OBSERVATIONAL TRENDS.
AS OF 730 PM EDT SUNDAY...VERY FEW ADDITIONAL CHANGES TO THE GRIDS
THIS EVENING WITH JUST MINOR TWEAKS TO POPS/SKY/TEMPS/DEWPOINTS.
CONVECTION IS BEGINNING TO WANE AS EXPECTED THOUGH THERE IS STILL
SOME ENHANCED CU AT THE HIGHER ELEVATIONS...BUT THE TREND IS
DEFINITELY DOWN. STILL MONITORING OVERNIGHT FOG POTENTIAL WHICH WILL
BE HEAVILY DEPENDENT ON HOW THE GROUND RESPONDS TO THE RAINFALL THIS
EVENING. OVERALL NO SIGNIFICANT CHANGES AT THIS TIME.
AS OF 430 PM EDT SUNDAY...HAVE INCREASED POPS ACROSS MAINLY THE
UPSTATE TO ACCOUNT FOR INCREASING SHOWER ACTIVITY. ONLY ISOLATED
LIGHTNING STRIKES HERE AND THERE SO KEPT THUNDER WORDING AT CHANCE
WITH LIKELY SHOWERS. VERY EFFICIENT RAINFALL PRODUCERS WITH ONE
REPORT OF 2 INCHES IN 45 MINUTES IN TRANSYLVANIA COUNTY. WILL
CONTINUE TO MONITOR AND ADJUST POPS ACCORDINGLY AS NECESSARY. MADE
SIMILAR ADJUSTMENTS TO SKY COVER FOR THE NEXT FEW HOURS...AND SOME
MINOR TWEAKS TO HOURLY TEMPS/WINDS/DEWPOINTS BASED ON OBS.
AS OF 230 PM EDT SUNDAY...CU FIELD IS BUBBLING INTO ISOLATED SHOWERS
ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA. WITH CAPE GENERALLY
LIMITED TO THE 1000-1500 J/KG RANGE ACROSS THIS AREA...IT/S
DEBATABLE AS TO WHETHER ANY UPDRAFTS WILL BECOME STRONG ENOUGH TO
PRODUCE LIGHTNING...BUT WILL CONTINUE A MENTION OF ISOLATED/WIDELY
SCT SHOWERS AND STORMS ACROSS THE WESTERN 2/3 OF THE FORECAST AREA
THROUGH THE AFTERNOON. ANY LINGERING CONVECTION SHOULD DISSIPATE
RATHER QUICKLY AFTER SUNSET...GIVING WAY TO A TYPICALLY WARM/MUGGY
NIGHT...WITH MIN TEMPS EXPECTED TO AVERAGE A COUPLE OF DEGREES ABOVE
CLIMO...POSSIBLY EVEN WARMER DEPENDING UPON IF/HOW SOON LOW CLOUDS
EXPAND ACROSS THE FORECAST AREA WITHIN INCREASING SOUTHERLY FLOW
REGIME.
SUBSTANTIVE UPPER HEIGHT FALLS WILL OVERSPREAD THE EASTERN CONUS BY
THE END OF THE NEAR TERM PERIOD...ALLOWING FOR RETROGRESSION OF THE
LONG WAVE PATTERN. HIGHER RESOLUTION SHORT TERM MODELS ARE IN GOOD
AGREEMENT IN DROPPING A SHORT WAVE TROUGH INTO WESTERN NC BY MONDAY
AFTERNOON...ACCOMPANIED BY INCREASING DEEP LAYER MOISTURE. IMPROVING
MID-LEVEL LAPSE RATES RESPONDING TO RIDGE RETROGRESSION SHOULD
RESULT IN IMPROVED...BUT STILL SOMEWHAT MODEST INSTABILITY PROFILES.
CONSIDERING THESE INGREDIENTS...COVERAGE OF CONVECTION SHOULD BE
QUITE RESPECTABLE MONDAY AFTERNOON...AND ANYWHERE FROM 50-70 POPS
WILL BE ADVERTISED...GENERALLY ALONG/NORTH OF I-85...TAPERING TO
30-40 PERCENT SOUTH OF THERE. DESPITE INCREASING SHEAR PROFILES
DEVELOP AS A CONSEQUENCE OF ANOMALOUSLY STRONG HEIGHT FALLS...THE
SEVERE CONVECTIVE THREAT APPEARS MARGINAL AT BEST MON PM...OWING TO
THE EXPECTED ABSENCE OF ROBUST INSTABILITY. STILL CAN/T RULE OUT
SOME ISOLATED SEVERE STORMS...ESP IF THE SHEAR PROVES STRONG ENOUGH
TO ORGANIZE SMALL CONVECTIVE CLUSTERS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 230 PM SUNDAY...A LARGE UPPER TROF WILL DIG ACRS THE GREAT
LAKES AND OHIO VALLEY MONDAY NIGHT THRU TUESDAY...SHARPENING THE
TROF AXIS ALONG THE APPALACHIANS BY WEDNESDAY. THIS WILL COINCIDE
WITH A COLD FROPA ON TUESDAY...WHICH SHUD HAVE DECENT QG FORCING AND
MOISTURE FOR GOOD CONVECTIVE COVERAGE. MOISTURE AND UPGLIDE AHEAD OF
THE FRONT WILL KEEP A CHC POP THRU THE OVERNIGHT MONDAY NIGHT. THEN
ON TUESDAY...THE MODELS ARE IN DECENT AGREEMENT ON THE FRONT
CROSSING THE CWFA TUESDAY EVENING. THERE SHUD STILL BE PLENTY OF
INSTBY FOR AT LEAST A SOLID CHC POP ALONG AND EAST OF THE BLUE
RIDGE. SBCAPE WILL RANGE FROM 1500-2500 J/KG PER THE GFS/NAM BLEND.
THE 0-6 KM BULK SHEAR WILL BE AROUND 25-30 KTS. SO EXPECT SOME
ORGANIZATION POTENTIAL WITH CONVECTION TUESDAY AFTN/EVE. THE DAY 3
CONVECTIVE OUTLOOK HAS A MARGINAL RISK ROUGHLY ALONG I-85 AND EAST.
TEMPS WILL BE A CATEGORY OR TWO ABOVE NORMAL MONDAY NIGHT AND
TUESDAY...THEN AT OR SLIGHTLY BELOW NORMAL TUESDAY NIGHT AND
WEDNESDAY DRIER AIR AND COOLER THICKNESSES COME IN BEHIND THE FRONT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 145 PM SUNDAY...STARTING AT 00Z THURSDAY...THE 500MB PATTERN
SHOWS A TROUGH OVER THE EAST WITH AXIS ALONG THE APPALACHIANS AND A
RIDGE OVER THE ROCKIES. GOING INTO FRIDAY AND SATURDAY...THE
SOUTHERN PART OF THE EASTERN TROUGH IS EXPECTED SHEAR OFF GRADUALLY
INTO A CUT OFF UPPER LOW WHICH SHOULD BE FORMED BY SATURDAY NIGHT
OVER THE MISS DELTA. THIS CUT OFF LOW IS EXPECTED TO DRIFT WEST TO
THE TEXAS COAST BY SUNDAY NIGHT WHICH IS THE END OF THE CURRENT
FORECAST PERIOD.
AT THE SURFACE FOR WED NIGHT...DRY HIGH PRESSURE CENTERED NEAR
CHICAGO AND A STALLED OUT FRONT FROM THE GULF COAST TO NRN FLORIDA
THEN OUT OVER THE ATLANTIC OFF THE CAROLINA COAST. THE FRONT IS
CLOSE ENOUGH THROUGH THE EARLY WEEKEND THAT IF A STRONG WAVE OF LOW
PRESSURE WERE TO PASS ALONG IT...THE RESULT MAY BE A FEW SHOWERS FOR
OUR SE ZONES MAINLY OVER THE PIEDMONT OR OVER THE FAR SOUTHERN MTNS.
CURRENT LOW LEVEL WIND FORECAST HAS A NORTHERLY WIND WED
NIGHT...PERHAPS AN UPSLOPE WIND FROM THE EAST TO SE THURSDAY AND
THURSDAY NIGHT...THEN LIGHT AND VARIABLE THROUGH SUNDAY NIGHT. ON
SUNDAY...THE FRONT IS FORECAST TO DRIFT MORE SOUTH OVER FLORIDA AND
DRIER AIR OVER OUR AREA WITH HIGH PRESSURE. ALTHOUGH CAPES ARE
FORECAST TO BE AROUND 2000 OR ABOVE FOR THE NC MTNS LATE SAT AND
SUN...THERE IS VERY LITTLE MOISTURE. TEMPS A FEW DEGREES BELOW
NORMAL THURSDAY THEN SLOWLY RECOVERING TO AROUND NORMAL SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...CONTINUED IDEA OF PREVIOUS TAF WITH BRINGING IN LOW SCT
STCU BEFORE SUNRISE. NOT ENUF MOISTURE RESPONSE ON RAP SOUNDINGS TO
GO FOR A CIG ATTM. STILL EXPECT TSTMS THIS AFTERNOON...BUT MAY HAVE
TO PUSH BACK TIMING ON THE 12Z TAF. MODEL PROGRESSION OF MUCAPE IS
IS SLOW TO MOVE EAST AS LLVL CLOUD COVER COULD PERSIST THROUGH NOON
OR SO. IN FACT THE PREFRONTAL DEEP CONVECTION MAY REMAIN WEST OF
THE TERMINAL UNTIL LATE IN THE PERIOD.
ELSEWHERE...SOME MVFR/IFR IS POSSIBLE AT KAVL AND KHKY THIS MORNING
AS TTD/S ARE RUNNING 1-2 F. POSSIBLE VSBY CONCERNS ACROSS THE SC
SITES AS WELL ARND DAYBREAK. CONVECTIVE ACTIVITY WILL AFFECT KAVL
ARND 18Z AS PREFRONTAL TROF DEVELOPS AND FORCING SPREADS EAST
INDUCING THUNDER AT THE OTHER TERMINALS 1-3 HRS LATER. PRECIP AND
THUNDER WILL PERSIST NEAR ALL TERMINALS LATE IN THE TAF PERIOD WITH
SOME VSBY/CIGS ISSUES PROBABLE.
OUTLOOK...HEAVY RAINFALL MON AFTN/EVENING ASSOCIATED WITH THE COLD
FRONT/SHORTWAVE COULD LEAD TO SOME MORNING RESTRICTIONS TUE.
DRIER/VFR CONDITIONS RETURN BY TUE EVENING...AND SHOULD PREVAIL THRU
AT LEAST THURSDAY.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 95% HIGH 90% HIGH 100%
KAVL HIGH 100% MED 78% HIGH 100% HIGH 93%
KHKY HIGH 100% HIGH 90% HIGH 85% HIGH 100%
KGMU HIGH 100% MED 68% MED 70% HIGH 100%
KAND HIGH 100% HIGH 95% HIGH 95% 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_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...SBK/TDP
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
439 AM CDT MON AUG 10 2015
.DISCUSSION...
A COMPLEX WEATHER DAY ACROSS THE MIDSOUTH. THE UPPER LEVEL RIDGE
THAT BROUGHT TRIPLE DIGIT HEAT CLOSE TO THE MIDSOUTH YESTERDAY HAD
RETROGRADED OVER THE PAST 12 HOURS...RETURNING NORTHWEST FLOW
ALOFT TO THE MIDSOUTH.
SEVERAL THUNDERSTORM COMPLEXES HAD FORMED OVER SOUTHERN MO EARLY
THIS MORNING...MOVING SOUTHEAST ALONG THE UPPER RIDGE PERIPHERY.
ASSUMING THE COLD POOL CAN REMAIN ESTABLISHED THROUGH SUNRISE...
850-500MB THICKNESS FIELDS SUGGEST THESE STORMS WILL MOVE
SOUTH/SOUTHEAST THROUGH NORTHEAST AR...WEST TN AND NORTHEAST MS.
THE HRRR MODEL HAS BEEN CONSISTENT IN DEPICTING SUCH A SCENARIO.
THE AIRMASS FEEDING THESE STORMS WAS RICH WITH MOISTURE...WITH
PRECIPITABLE WATER VALUES AROUND 2.25 INCHES. THE LOW LEVEL JET
HAS BEEN A RELATIVELY WEAK 20KTS...BUT ADEQUATE TO MAINTAIN
STORMS EARLY THIS MORNING.
THUNDERSTORM EVOLUTION THROUGH MIDDAY WILL HAVE SIGNIFICANT
IMPACTS ON AFTERNOON HEAT INDICES. HAVE TRIMMED BACK HEAT
HEADLINES TO REFLECT THE IMPACTS OF THUNDERSTORM OUTFLOW AND
INITIAL CLOUD COVER. HEAT INDEX FORECAST CONFIDENCE IS MARGINAL...
BUT PERHAPS BEST OVER THE MS RIVER DELTA...FROM CLARKSDALE TO
CHARLESTON MS. THIS AREA WILL LEAST LIKELY BE IMPACTED BY
THUNDERSTORM OUTFLOW AND CLOUD COVER...AND NEAREST TO THE
AFTERNOON LOW LEVEL THERMAL RIDGE OVER SOUTHERN AR AND CENTRAL MS.
A WEAK COLD FRONTAL PASSAGE APPEARS ON TRACK FOR LATE THIS EVENING
AND EARLY OVERNIGHT. COOLER AND DRIER AIR WILL LAG 12 TO 18 HOURS
BEHIND THE INITIAL WIND SHIFT...BUT LIKELY SUFFICIENT TO KEEP
TUESDAY AFTERNOON HEAT INDICES BELOW ADVISORY CRITERIA.
WEDNESDAY AND THURSDAY SHOULD SEE COOLER AND DRIER CONDITIONS...WITH
NORTHERLY WINDS. DAYTIME TEMPS WILL GRADUALLY MODERATE TO NEAR
NORMAL VALUES FROM FRIDAY THROUGH NEXT MONDAY...AS THE UPPER RIDGE
BUILDS INTO THE MIDDLE MS RIVER VALLEY. RAIN CHANCES FROM MIDWEEK
THROUGH EARLY NEXT WEEK APPEAR MINIMAL.
PWB
&&
.AVIATION...
06Z TAF CYCLE
A MESOSCALE CONVECTIVE SYSTEM IS BACK BUILDING ACROSS SOUTHEASTERN
MO AND SOUTHERN IL. THIS SYSTEM IS EXPECTED TO GENERATE A SOUTHWARD
MOVING OUTFLOW BOUNDARY THAT WILL RESULT IN SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS AFFECTING KMKL AND KJBR AFTER
10/08Z...KMEM AFTER 10/11Z AND CONTINUE THROUGH MUCH OF THE MORNING.
CONDITIONS MAY LOWER TO MVFR OR IFR IN THE HEAVIER THUNDERSTORMS
ESPECIALLY AT KMKL AND KJBR. SCATTERED SHOWERS AND THUNDERSTORMS
WILL DEVELOP ALONG AND AHEAD OF A COLD FRONT APPROACHING AND MOVING
INTO THE AREA FROM THE NORTH BEGINNING MONDAY AFTERNOON. VFR
CONDITIONS WILL OCCUR MUCH OF THE PERIOD AT THE TAF SITES OUTSIDE
ANY SHOWERS AND THUNDERSTORMS.
LIGHT WINDS TONIGHT BECOMING WESTERLY MONDAY 6-8 KTS. WINDS MAY BE
STRONG AND GUSTY NEAR THUNDERSTORMS.
AFTER 11/00Z...THE COLD FRONT WILL CONTINUE SOUTHWARD THOUGH THE
REGION. WINDS TURNING TO THE NE AT 4-7 KTS WITH THE THREAT OF
SHOWERS AND THUNDERSTORM ENDING FOLLOWING THE FRONT.
JCL
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR PHILLIPS.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR CRITTENDEN-CROSS-LEE AR-POINSETT-ST. FRANCIS.
MO...NONE.
MS...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR CALHOUN-COAHOMA-QUITMAN-TALLAHATCHIE-YALOBUSHA.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR BENTON MS-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TUNICA-
UNION.
TN...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR FAYETTE-SHELBY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1228 AM CDT MON AUG 10 2015
.AVIATION.../06Z TAFS/
NO CONCERNS WITH HIGH PRESSURE REMAINING IN CONTROL AT THE SURFACE
AND ALOFT. SATELLITE CURRENTLY SHOWING LOW CLOUD DEVELOPMENT OVER
THE COASTAL PLAINS. EXPECT TO SEE KSAT/KSSF BECOME MVFR 07Z-08Z.
NOT AS CONFIDENT FOR KAUS AND WILL CONTINUE WITH A TEMPO FOR MVFR
CIGS THERE. KDRT WILL ONLY SEE AN HOUR OR TWO OD SCT SO NO ISSUES.
S/SE WINDS WILL DECREASE TO NEAR 10 KNOTS AFTER 06Z. SOUTHERLY
WINDS INCREASE TO 10-15 KNOTS WITH GUSTS TO NEAR 20 KNOTS AFTER
15Z AND BECOME SELY SAME SPEEDS AFTER 21Z. LIKELY TO SEE LESS LOW
CLOUD DEVELOPMENT FOR MON NIGHT INTO TUES MORNING SO NO ISSUES FOR
THE 30 HOUR TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 852 PM CDT SUN AUG 9 2015/
UPDATE... /NPW CANCELED/
ALL HEAT INDEX REPORTS IN THE AREA FELL BELOW 105 AND WELL BELOW
THE ADVISORY CRITERIA OF 108/110 DEGREES FOR EAST/WEST COUNTIES.
A SPECIAL WEATHER STATEMENT FOR THE NEXT COUPLE DAYS REPLACES THE
CANCELED HEAT ADVISORY.
PREV DISCUSSION... /ISSUED 637 PM CDT SUN AUG 9 2015/
AVIATION.../00Z TAF CYCLE/
VFR SKC ACROSS MUCH OF THE REGION WITH ONLY A FEW/SCT250 CIRRUS
CLOUDS AS OF 09/2330Z. VFR WILL CONTINUE UNTIL 09Z OR SO WITH
DEVELOPMENT OF MVFR STRATUS CLOUDS INVOF KSAT/KSSF AND KAUS THROUGH
14-15Z. HIGHEST CONFIDENCE EXISTS FOR SAT/SSF PER SOUNDING ANALYSIS
AND HRRR OUTPUT. KAUS COULD ALSO BE IMPACTED WITH BKN015 CIGS BUT
MAY BE MORE SPORADIC. KDRT SHOULD STAY VFR THROUGH THE NIGHT BUT
STRATUS WAS CLOSE BY THIS MORNING AND THIS TREND WILL NEED TO
MONITORED IN THE 06Z TAF ISSUANCE. CURRENT SURFACE WINDS OF 10-15 KT
OUT OF THE SE WILL CALM TO 5-10KT OVERNIGHT. VFR CONDITIONS WILL
PREVAIL MONDAY AFTER 15Z WITH A REPEAT OF TODAY.
PREV DISCUSSION... /ISSUED 240 PM CDT SUN AUG 9 2015/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE THIS AFTERNOON. CURRENT
HEAT ADVISORY WILL EXPIRE THIS EVENING. PEAK HEATING HAS YET TO
OCCUR BUT LOOKS LIKE A FEW SPOTS WILL HIT ADVISORY CRITERIA MAINLY
OVER THE FAR EAST...DECENT MIXING ACROSS THE REST OF THE AREA WILL
DROP DEW POINTS THROUGH THE DAY. MILD NIGHT TONIGHT WITH A REPEAT
OF STRATUS FORMATION ACROSS CENTRAL SECTIONS WITH STRONGER LOW LEVEL
SOUTHERLY FLOW. ANOTHER HOT DAY ON MONDAY BUT THE UPPER RIDGE WILL
START A WESTWARD MOVEMENT THAT WILL BRING SLIGHT ADJUSTMENTS TO POP
AND TEMPS LATER IN THE WEEK. FAIRLY LOW DEWPOINTS WILL GENERALLY
KEEP AREA HEAT INDEX VALUES JUST BELOW HEAT ADVISORY CRITERIA
LEVELS. A WEAK FRONT WILL PUSH SOUTH INTO THE RED RIVER
AREA...HELPING TO DECREASE THE GRADIENT MONDAY NIGHT AND LIMIT THE
EARLY MORNING CLOUD COVER BY TUESDAY.
LONG TERM (TUESDAY THROUGH SUNDAY)...
AS THE UPPER RIDGE SHIFTS WEST BY MID WEEK...A SIMILAR
PATTERN WILL DEVELOP LIKE THE END OF JULY. A WEAK BACKDOOR COOL
FRONT WILL PUSH INTO EAST AND NE TEXAS AS MID AND UPPER FLOW BECOMES
INCREASINGLY EASTERLY/NORTHEASTERLY. RH TIME SECTIONS SHOWS AN
INCREASE IN MID LEVEL MOISTURE STARTING LATE TUE INTO WED. THIS
MOISTURE INCREASE...ALONG WITH THE EXPECTED HOT TEMPS...SHOULD BE
ENOUGH TO FIRE UP ISOLATED/SCT CONVECTION DURING THE
AFTERNOON/EVENING HOURS ON WED AND AGAIN ON THU. LIKE THE PREVIOUS
SYSTEM ABOUT 10 DAYS AGO...STORMS COULD PRODUCE SOME STRONG
DOWNDRAFTS...WITH SEVERAL OUTFLOW BOUNDARIES LIKELY HELPING TO
INITIATE ADDITIONAL STORMS. THIS MID LEVEL MOISTURE WILL PUSH WEST
THROUGH THE WEEK...AND BY WEEKS END...POP WILL BE CONFINED TO THE
FAR WEST AND NORTHWEST.
BY THE WEEKEND AND EARLY NEXT WEEK...LONG RANGE MODELS ARE SHOWING
AN UPPER LOW OVER THE SE U.S. MOVING WEST ALONG THE NORTHERN GULF
COAST...MOVING TOWARD THE TEXAS COAST. LOWERING 500MB HEIGHTS AND
BETTER MOISTURE LEVELS WILL KEEP THE INTENSE HEAT AWAY...BUT THE
HIGHER DEWPOINTS MIGHT ACTUALLY KEEP HEAT INDEX VALUES PLENTY WARM.
CANT RULE OUT SOME CHANCES OF RAIN ESPECIALLY IN THE COASTAL PLAINS
DUE TO THE PROXIMITY OF THE UPPER LOW. THE HOPE WILL BE FOR THIS
SYSTEM AND MOISTURE TO PUSH FARTHER INLAND AND GIVE SOME RAIN
CHANCES BEYOND THE 7 DAY PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 102 78 101 77 / 0 0 0 - 10
AUSTIN BERGSTROM INTL AIRPORT 74 101 74 101 76 / 0 0 0 - 10
NEW BRAUNFELS MUNI AIRPORT 77 102 76 101 76 / 0 0 0 0 -
BURNET MUNI AIRPORT 73 101 76 101 78 / 0 0 0 - 10
DEL RIO INTL AIRPORT 77 102 77 103 78 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 75 102 77 102 79 / 0 0 0 - 10
HONDO MUNI AIRPORT 74 101 74 102 75 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 76 100 75 101 77 / 0 0 0 - -
LA GRANGE - FAYETTE REGIONAL 75 101 77 103 77 / 0 0 0 10 10
SAN ANTONIO INTL AIRPORT 78 101 77 101 78 / 0 0 0 0 -
STINSON MUNI AIRPORT 77 102 76 101 77 / 0 0 0 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
314 AM EDT MON AUG 10 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTHEAST INTO THE REGION TODAY BEFORE
SLIDING TO THE NORTH LATER TONIGHT. A STRONG COLD FRONT WILL PUSH
EAST INTO THE MOUNTAINS BY EARLY TUESDAY AND ACROSS THE REMAINDER
OF THE REGION BY TUESDAY EVENING. HIGH PRESSURE BUILDS INTO THE
AREA BEHIND THE FRONT BY WEDNESDAY...BRINGING SOMEWHAT COOLER AND
DRIER AIR FOR MIDWEEK INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 AM EDT MONDAY...
CLUSTERS OF VERY SLOW MOVING SHOWERS CONTINUE TO DEVELOP EARLY THIS
MORNING ESPCLY OVER THE EAST IN ADVANCE OF A RATHER STRONG MID LEVEL
WAVE DIPPING IN FROM THE NW JUST NORTH OF THE FRONT TO THE SW. THIS
UNDERDONE BY MOST SHORT TERM MODELS INCLUDING THE HRRR SO BUMPING UP
POPS TO AT LEAST CHANCE IN PARTS OF THE EAST AND SLIGHTS OVER THE WEST
WHERE SHRA MORE SPOTTY NATURE CLOSER TO THE ACTUAL IMPULSE ALOFT.
ONCE THIS FEATURE PASSES...LOTS OF UNCERTAINTY IN REGARDS TO THE
CONVECTIVE ENVIRONMENT FROM LATE MORNING INTO THE AFTERNOON WITH A WARM
FRONT HEADING INTO THE MOUNTAINS WHILE CLOUD COVER MAY STAY RATHER
EXTENSIVE. GUIDANCE SOLUTIONS RANGE FROM THE BEST LIFT STAYING WEST OF
THE MOUNTAINS UNTIL THIS EVENING SUPPORTING ONLY SCATTERED SHRA/TSRA
BLUE RIDGE LATER...TO MORE OUTFLOW DRIVEN SUPPORT FROM THE MCS TO THE
WEST WITH THIS RESIDUAL WAVE INTERACTING WITH AT LEAST SOME HEATING
TO PRODUCE MORE MULTICELLULAR BANDS/CLUSTERS SIMILAR TO THE GFS/EC
AND NCAR ENSEMBLE. THIS ALONG THE LINGERING HIGHER 85H THETA-E RIDGE
WEST AND WHERE MODELS SUGGEST AT LEAST SOME DECENT CAPE MAY EXIST BUT
LATER. THUS TRENDED MORE ALONG THOSE LINES AND BUMPED GOING POPS TO A
PERIOD OF CATEGORICAL FAR WEST LATE AND LEFT LIKELYS IN ALL EXCEPT THE
SE WHERE MAY BE LATE OR THIS EVENING BEFORE WHATS LEFT OF WESTERN
COVERAGE MOVES EAST GIVEN WEAK STEERING. THIS COULD ALSO LEAD TO
MORE OF A HEAVY RAINFALL THREAT VS SEVERE GIVEN RATHER MEAGER FLOW
ALOFT AND LACK OF GOOD LAPSES UNLESS HEATING IS BETTER. NUDGED
HIGHS DOWN A FEW DEGREES TO ACCOUNT FOR EARLY CLOUDS/SHRA AND
POTENTIAL FOR QUICK DEVELOPMENT THIS AFTERNOON WITH ANY INSOLATION
PER PWATS OF NEARLY 2 INCHES.
GUIDANCE PUSHES A LOBE OF CONVECTION EAST/NE THIS EVENING AS THE WARM
FRONT LIFTS NORTH AND THE COLD FRONT APPROACHES FROM THE WEST LATE.
THINK BEST COVERAGE THROUGH MIDNIGHT OR SO WITH A RESIDUAL WAVE
OVERHEAD BEFORE POSSIBLY SEEING A BREAK IN ALL EXCEPT THE NORTH LATE AS
THE REGION SLIPS IN BETWEEN THE EXITING WARM FRONT AND UPSTREAM COLD
FRONT. THE COLD FRONT MAY ALSO END UP BRINGING ANOTHER BAND OF
SHRA INTO THE NW SLOPES TOWARD DAYBREAK...SO BLENDING POPS FROM
LIKELYS MOST SPOTS TO INIT...TO MAINLY CHANCE IN ALL EXCEPT THE
EAST/SE OVERNIGHT...AND OVER THE NW LATE. AGAIN MORE HEAVY RAIN
POTENTIAL BUT EXPECT SHRA/TSRA TO MOVE A BIT MORE LATE AS WESTERLY
FLOW DEEPENS SOME AHEAD OF THE COLD FRONT. STILL QUITE WARM/MUGGY
WITH LOWS UPPER 60S/LOW 70S EXCEPT MID 60S VALLEYS AND IN SPOTS
THAT RECEIVE HEAVIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
MODELS HAVE OUR NEXT COLD FRONT MOVING ACROSS THE MOUNTAINS TUESDAY
MORNING...STALLING NEAR THE BLUE RIDGE BY THE AFTERNOON. THE FRONT
WILL EVENTUALLY CLEAR THE PIEDMONT TUESDAY EVENING...WAITING ON A
SURFACE WAVE THAT WILL DEVELOP OVER THE CAROLINAS THEN MOVE OFF THE
MID ATLANTIC COAST. WE CAN NOT RULE OUT SCATTERED SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS TUESDAY AFTERNOON...BUT THE
MAJORITY OF THE STRONGER CONVECTION WILL BE ALONG AND EAST OF HWY
29. THE COVERAGE OF STRONG STORMS FOR THE FORECAST AREA WILL DEPEND
ON THE LOCATION OF THE COLD FRONT AND THE TRACK OF THIS SURFACE
WAVE. MOST MODELS ARE KEEPING THE STRONGER CONVECTION WITH THE
SURFACE LOW OVER CENTRAL NORTH CAROLINA AND THE COASTAL PIEDMONT OF
VIRGINIA. FOR NOW...WILL KEEP CHANCE POPS ACROSS THE FORECAST AREA.
POPS WILL INCREASE IF THE FRONT REMAINS FARTHER TO THE WEST OR
LOWER/DECREASING THROUGH THE AFTERNOON IF THE FRONT PUSHES EAST OF
THE BLUE RIDGE. THE FRONT WILL BE ALONG THE CAROLINA COAST ON
WEDNESDAY. THE DEW POINT FRONT WILL CROSS OVER THE REGION BY
WEDNESDAY EVENING. WITH THE UPPER LEVEL TROUGH OVERHEAD AND
LINGERING LOW LEVEL MOISTURE WEDNESDAY...A GOOD AMOUNT OF FAIR
WEATHER CUMULUS CLOUDS WILL BE PRESENT...BUT NOT EXPECTING ANY TO
PRODUCE MEASURE RAINFALL.
TEMPERATURES ARE EXPECTED TO WARM TO NEAR NORMAL LEVELS TUESDAY.
BEHIND THE FRONT...COOLER THAN NORMAL CONDITIONS ARE EXPECTED...70S
WEST TO LOWER TO MID 80S EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...
MODELS ARE ADVERTISING A RETREAT OF THE UPPER TROF OVER THE
NORTHEAST THIS TIME FRAME. THE LARGE UPPER RIDGE OVER THE CENTRAL
UNITED STATES SLIGHTLY RETROGRADES AND BUILDS NORTHEAST INTO THE
OHIO VALLEY AS A LOW CUTS OFF SOMEWHERE AROUND THE NORTHERN GULF.
AT THE SURFACE BY THURSDAY...HIGH PRESSURE WILL EXTEND FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC REGION. THIS HIGH REMAINS
OVER THE FORECAST AREA THROUGH FRIDAY. MODELS WERE BEGINNING TO
SUGGEST A WEAK LOW OR SOME LEE TROUGHING MAY DEVELOP ON THE EASTERN
SIDE OF THE APPALACHIANS ON SATURDAY. STILL NOT ENOUGH LIFT OR
MOISTURE FOR ANY SUBSTANTIAL PROBABILITY OF PRECIPITATION.
WILL BE STARTING THURSDAY MORNING WITH BELOW NORMAL MINIMUM
TEMPERATURES THEN AIR MASS GRADUALLY MODERATES THROUGH SUNDAY.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
AS OF 1245 AM EDT MONDAY...
STILL SEEING ISOLATED SLOW MOVING SHOWERS AROUND THE KLYH VICINITY
AND EXPECT THESE TO LINGER A WHILE LONGER BEFORE PUSHING EAST AND
WEAKENING WELL BEFORE DAYBREAK. THIS MAY BRING A PERIOD OF LOWER
MVFR VSBY IN SHRA FOR KLYH OVER THE NEXT COUPLE OF HOURS ALONG
WITH A MVFR CIG. OTRW EXPECTING ONLY ISOLATED ADDED SHOWER
COVERAGE OVERNIGHT WITH LOTS OF STRATO-CU/AC PUSHING IN FROM THE
NW AHEAD OF A WARM FRONT TO THE WEST. MODELS CONTINUE TO BRING A
LOW END VFR/HIGH END MVFR CIGS OVER MOST OF THE AREA...SO TWEAKED
CIGS DOWN IN SPOTS BUT NOT AS LOW AS CURRENT GUIDANCE. THUS WILL
LEAN TOWARD VFR THROUGH MOST OF THE OVERNIGHT BUT SEEING SOME FOG
POTENTIAL AT KBLF/KLWB/KBCB AS WELL AS KLYH IN THE PRE DAWN HOURS
WHEN PERIODS OF IFR/MVFR COULD DEVELOP IF CLOUDS ARE LESS.
BASED ON FORECAST CONSENSUS SHOULD SEE VFR TO MVFR CIGS MONDAY
MORNING WITH SHOWERS AND A FEW THUNDERSTORMS ARRIVING INTO THE
WEST TOWARD MIDDAY/18Z AND EAST BY 20Z. KEPT VCTS IN WITH MODERATE
SHRA AT ALL SITES AFTER 18Z-20Z...WITH MVFR CIGS AT ALL EXCEPT VFR
AT KDAN WHERE WILL HOLD OFF ON PRECIP. SHOWERS LIKELY TO LINGER OR
REDEVELOP OVER THE WEST AFTER THE INITIAL CONVECTION SO LEAVING IN
A MVFR MENTION INTO THE EVENING FOR ALL SITES EXCEPT OVER THE
SOUTHEAST. SHOWERS AND ADDED TSRA COULD ALSO PERSIST OVER THE
SOUTH AND WEST INTO LATER MONDAY NIGHT GIVEN OUTFLOW AND APPROACH
OF THE COLD FRONT FROM THE WEST LATE. OTRW CUTTING BACK ON ADDED
SHRA BY MIDNIGHT AT MOST LOCATIONS FOR NOW TO SEE HOW TRENDS
UNFOLD LATER ON.
EXTENDED AVIATION DISCUSSION...
TUESDAY...SHOWERS AND STORMS INCREASE AGAIN ACROSS THE REGION
THANKS TO BOTH A FRONTAL BOUNDARY ENTERING THE REGION AND A
SHORTWAVE TROUGH PROGRESSING EASTWARD THROUGH THE OHIO VALLEY.
MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT SUB-VFR CONDITIONS WHERE
CONVECTION BECOMES MORE ORGANIZED. STRONGER STORMS WILL BE
POSSIBLE LATER TUESDAY...MAINLY ALONG AND EAST OF THE KLYH-KDAN
CORRIDOR.
BY WEDNESDAY INTO FRIDAY...ANOTHER AREA OF HIGH PRESSURE BUILDS
INTO THE REGION MAKING FOR OVERALL VFR CONDITIONS. PATCHY LATE
NIGHT AND EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG WILL AGAIN
BE POSSIBLE...THOUGH AIRMASS WILL LIKELY BE DRIER.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/JM/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1154 PM CDT SUN AUG 9 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 214 PM CDT SUN AUG 9 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD
FRONT STRETCHING FROM SOUTHWEST MINNESOTA TO THE WESTERN UPPER
PENINSULA. THIS FRONT HAS BEEN MOSTLY INACTIVE SO FAR
TODAY...OUTSIDE OF A FEW SHOWERS OVER VILAS COUNTY EARLY THIS
MORNING. LOW STRATUS OVER NORTHERN WISCONSIN HAVE HELD BACK TEMPS
SOMEWHAT...WHICH IS KEEPING INSTABILITY LIMITED TO UNDER 800 J/KG SO
FAR THIS AFTERNOON. THE STRATUS IS SHOWING NO SIGNS OF BREAKING UP
EITHER. BIGGER CONCERNS REVOLVE AROUND THE SHOWERS AND
THUNDERSTORMS MOVING INTO WESTERN WISCONSIN ASSOCIATED WITH A
SHORTWAVE IMPULSE. THUNDERSTORMS ARE EXPANDING WITHIN THE
INSTABILITY AXIS OVER NORTHWEST WISCONSIN...AND A ROUGH TIMING SHOWS
STORMS MOVING INTO NORTH-CENTRAL WISCONSIN IN THE 3-5PM RANGE. DUE
TO THE LIMITED INSTABILITY...STILL THE SEVERE THREAT IS RATHER LOW.
BUT SMALL HAIL AND GUSTY STRAIGHT LINE WINDS WILL BE POSSIBLE.
FORECAST CONCERNS REVOLVE AROUND THUNDERSTORM POTENTIAL.
TONIGHT...THE COLD FRONT WILL REMAIN NEARLY STATIONARY FOR THE REST
OF THE AFTERNOON...AND THEN SHIFT SOUTHEAST AS THE SHORTWAVE IMPULSE
MOVES ACROSS THE AREA THIS EVENING. SHOWERS AND THUNDERSTORMS NOW
LOOK LIKELY ACROSS MOST OF THE AREA THIS EVENING...EXCEPT FOR MAYBE
THE SOUTHERN TIER. HAVE INCREASED PRECIP CHANCES INTO THE LIKELY
RANGE...AS THE SHORTWAVE SHOULD BE ABLE TO INTERACT WITH SOME OF
LINGERING DAYTIME INSTABILITY. THE RAINFALL SHOULD HELP GIVE SOME
SOUTHEAST PUSH TO THE COLD FRONT WHICH WILL MOVE INTO EAST-CENTRAL
WISCONSIN LATE. WITH THE RAINFALL AND FRONT NEARBY...THINK LOW
STRATUS AND/OR FOG WILL REDEVELOP AFTER MIDNIGHT. SOME DENSE FOG
LIKE EARLY THIS MORNING IS POSSIBLE IN SPOTS.
MONDAY...THE FRONT DOES NOT MAKE MUCH PROGRESS SOUTHWARD...LEAVING
NORTHEAST WISCONSIN IN CLOSE PROXIMITY TO THE FRONT. THOUGH HAVE
SOME CONCERN THAT TONIGHTS RAIN WILL PUSH THE FRONT SOUTH OF THE
AREA...LEFT A CHANCE OF STORMS IN THE FORECAST DURING THE AFTERNOON
OVER THE EAST. NO SEVERE STORMS ARE EXPECTED DUE TO MEAGER 0-6KM
SHEAR OF 10 KTS. HIGHS TO RANGE FROM THE MID 70S TO LOW 80S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 214 PM CDT SUN AUG 9 2015
A TRANSITION IN THE UPPER LEVEL FLOW IS EXPECTED STARTING
TUESDAY...WHEN HIGH PRESSURE WILL STRENGTHEN OVER THE ROCKIES IN A
BLOCKING PATTERN THAT WILL KEEP THE NORTHEAST U.S. UNDER A LOW
PRESSURE TROUGH AND WISCONSIN UNDER A NORTHWEST FLOW. THIS
SCENARIO WILL PRODUCE DRIER CONDITIONS IN GENERAL FOR NORTHEAST
WISCONSIN...ALTHOUGH MODELS AGREE ON A CHANCE FOR PRECIPITATION
LATER IN THE WORK WEEK AS A WEAK COLD FRONT SWEEPS DOWN ON THE
NORTHWEST FLOW OUT OF CANADA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1154 PM CDT SUN AUG 9 2015
A WEAK COLD FRONT WILL MOVE ACROSS THE REGION
OVERNIGHT ACCOMPANIED BY SCATTERED SHOWERS. THERE ARE A LOT OF
MIDDLE CLOUDS WHICH MAY BREAK UP ENOUGH FOR LOW CLOUDS OR FOG TO
FORM LATER TONIGHT IN SOME AREAS. THE FOG WOULD END BY 15Z MONDAY
WITH VFR CONDITION EXPECTED BY AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ML
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS RENO NV
541 AM PDT MON AUG 10 2015
.UPDATE...
WE HAVE SEEN A FEW LIGHTNING STRIKES WITH THE WAVE LIFTING NORTH
ACROSS NE CA AND FAR NW NV THIS MORNING. AS THIS WAVES MOVES NORTH
THE TSTM/SHOWER ACTIVITY SHOULD END FROM SOUTH TO NORTH. WILL MAKE
SOME MINOR ADJUSTMENTS TO TIMING OF THE WEATHER THIS MORNING TO
ACCOUNT FOR THIS DECREASE FROM SOUTH TO NORTH. OTHERWISE NO
CHANGES TO THE CURRENT FORECAST. 20
&&
.PREVIOUS DISCUSSION... /ISSUED 230 AM PDT MON AUG 10 2015/
SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE THROUGH THIS MORNING WITH A SLIGHT
CHANCE OF THUNDERSTORMS NORTH OF INTERSTATE 80. SOUTH FLOW THEN
RESUMES MONDAY AFTERNOON AS LOW PRESSURE DROPS OFF THE WEST
COAST. DRY CONDITIONS WITH TYPICAL AFTERNOON BREEZES AND NEAR
NORMAL TEMPERATURES ARE EXPECTED. WINDY CONDITIONS ARE POSSIBLE
THURSDAY AS THE LOW MOVES INTO OREGON.
SHORT TERM...
WATER VAPOR AND IR SATELLITE IMAGERY SHOW A DEFINED UPPER LEVEL
DISTURBANCE MOVING INTO THE CALIFORNIA INTERIOR THIS MORNING. AS A
RESULT, ISOLATED VIRGA SHOWERS HAVE FORMED NORTH OF THE TAHOE
BASIN NORTHWARD INTO NORTHERN LASSEN COUNTY. THE HRRR AND NAM
CONCUR THAT ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
THROUGH MID MORNING TODAY AS THIS WAVE MOVES NORTHWARD. ANY
THUNDERSTORMS THAT DO RESULT WILL BE DRY WITH DRY LIGHTNING THE
PRIMARY THREAT. NEW FIRE STARTS WILL BE POSSIBLE, BUT COVERAGE OF
CELLS DOES NOT WARRANT A RED FLAG WATCH OR WARNING.
AS FOR CONSIDERATIONS INVOLVING THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, HAVE EXTENDED AREAS OF SMOKE THROUGH MID
MORNING IN SOUTHERN MONO COUNTY WITH HAZE PERSISTING INTO THE
AFTERNOON. FIRE ACTIVITY THIS MORNING WILL DETERMINE WHETHER OR
NOT THESE CONDITIONS PERSIST INTO TUESDAY.
OTHERWISE, LOW PRESSURE DEEPENS AND DROPS SOUTH IN THE EASTERN
PACIFIC WITH HIGH PRESSURE LOCATED OVER THE WESTERN PLAINS OF THE
UNITED STATES. THIS LEAVES THE SIERRA AND WESTERN NEVADA IN A
NEUTRAL PRESSURE ADVECTION REGION RESULTING IN GENERALLY BENIGN
WEATHER CONDITIONS. MOISTURE TRANSPORT VECTORS ARE NOT FAVORABLE
FOR A MONSOONAL MOISTURE SURGE AT THIS TIME. THE MOST SIGNIFICANT
IMPACTS THROUGH MID WEEK WILL COME FROM DRIER SOUTH TO WESTERLY
FLOW EACH AFTERNOON WITH LOCALLY BREEZY CONDITIONS FROM TYPICAL
AFTERNOON ZEPHYRS. AS SEEN WITH THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, THESE WINDS AND DRY CONDITIONS COULD
ACTIVATE HOLDOVERS ALLOWING FOR RAPID FIRE GROWTH. BOYD
LONG TERM...THURSDAY THROUGH SUNDAY...
MEDIUM RANGE OPERATIONAL MODELS ARE IN GOOD AGREEMENT AGAIN THIS
CYCLE THROUGH EARLY SATURDAY. AFTER THAT DIFFERENCES APPEAR...AS
THEY HAVE BEEN DOING SO FOR THE PAST FEW DAYS. UPPER LOW MOVES INTO
THE PAC NW ON THURSDAY WITH STRONG LOW LEVEL PRESSURE AND THERMAL
GRADIENTS OVER THE NORTHERN PART OF THE FORECAST AREA NORTH INTO
OREGON. THESE STRONG GRADIENTS SHOULD DRIVE GUSTY WEST TO SOUTHWEST
WINDS OVER THE NORTHERN 2/3RDS OF THE FORECAST AREA THURSDAY
AFTERNOON AND EVENING. INCREASED MIXING WILL PUSH TEMPS AT OR ABOVE
AVERAGE FOR ALL BUT THE FAR NORTHERN FORECAST AREA AND HUMIDITY
VALUES SHOULD BE FAIRLY LOW. THIS COMBINATION WILL LIKELY PRODUCE
CRITICAL FIRE WEATHER CONDITIONS FOR AT LEAST THE AREA NORTH OF
HIGHWAY 50.
UPPER LOW MOVES EAST FRIDAY WITH A LESSENING OF THE GRADIENT AND
ATTENDANT WINDS. TEMPS WILL ALSO DECREASE OVER FAR NORTHERN AREAS OF
THE CWA. DRY SOUTHWEST FLOW WILL KEEP ANY MENTION OF PCPN OUT OF THE
FORECAST THROUGH AT LEAST SATURDAY. THE OPERATIONAL MODELS START TO
DIVERGE SATURDAY WITH THE GFS HOLDING ON TO THE TROUGH A BIT LONGER
WHILE THE ECMWF STARTS TO WEAKEN THE TROUGH AND BUILD A FLAT RIDGE.
BY SUNDAY THE ECMWF IS MORE AGGRESSIVE BUILDING THE RIDGE AND THE
GFS MAINTAINS A WEAK TROUGH. THE GEFS ENSEMBLE MEMBERS SHOW SOME
SUPPORT FOR BOTH SOLUTIONS SO A COMPROMISE WAS MADE. THIS MEANT
KEEPING THE HIGH TEMPS BELOW THE ECMWF GUIDANCE FOR SATURDAY AND
SUNDAY.
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST. IF THE ECMWF
SOLUTION IS MORE CORRECT THEN WE MIGHT SEE AND OUTSIDE CHANCE AT
WEAK CONVECTION OVER THE FAR SOUTHERN CWA BY SUNDAY AS LIGHT UPSLOPE
FLOW BRINGS A BIT MORE MOISTURE BACK TO THE REGION. OTHERWISE DRY
WITH NEAR SEASONAL TEMPERATURES FOR THE EXTENDED PERIOD AND TYPICAL
AFTERNOON WINDS ONCE WE GET PAST THURSDAY. 20
AVIATION...
A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING
NORTH OF INTERSTATE 80 AS AN UPPER LEVEL WAVE OF LOW PRESSURE MOVES
NORTH. OUTSIDE OF THE WAVE THERE SHOULD BE VFR CONDITIONS TODAY.
TYPICAL SUMMER AFTERNOON WINDS ARE LIKELY TODAY WITH GUSTS EAST OF
THE SIERRA IN THE 20-25 KT RANGE.
HAZE AND SMOKE FROM CALIFORNIA FIRES WILL PRODUCE PERIODS OF
LOWERED VISIBILITY TODAY AND TUESDAY.
FAIRLY LIGHT WINDS TUESDAY. RIDGE WINDS BEGIN TO INCREASE WEDNESDAY
AND THEN GUSTY WINDS DEVELOP THURSDAY AHEAD OF A SURFACE BOUNDARY
THAT MOVES THROUGH THURSDAY NIGHT. INCREASED TURBULENCE IS HIGHLY
PROBABLE FROM LATE WEDNESDAY THROUGH THURSDAY. 20
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
401 AM MDT MON AUG 10 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 401 AM MDT MON AUG 10 2015
SHOWERS AND TSTMS CONTINUE EARLY THIS MORNING OVER THE ECNTRL PLAINS
DUE TO COMBINATION OF FNTL PASSAGE AND SOME WK MID LVL ASCENT MOVING
ACROSS. THIS ACTIVITY SHOULD BEGIN TO GRADUALLY END BY 12Z.
FOR LATER TODAY AN UPPER LEVEL HIGH WILL BEGIN TO REBUILD OVER THE
SRN ROCKIES WITH WLY FLOW ALOFT ACROSS NRN CO. MEANWHILE AS SFC
HIGH PRES BEGINS TO MOVE ESE OF THE AREA THE LOW LVL FLOW WILL
BECOME MORE SELY EAST OF THE MTNS AND KEEP DEEPER MOISTURE IN PLACE.
PW`S ARE FCST TO INCREASE INTO THE 1.00 TO 1.25 RANGE BY MID TO LATE
AFTN OVER NERN CO. AT THIS TIME CANNOT SEE ANY DEFINED DISTURBANCE
AFFECTING THE AREA THIS AFTN OR EVENING HOWEVER GRIDDED DATA DOES
SHOW SOME WL MID LVL ASCENT AFFECTING THE AREA.
OVERALL SHOULD SEE A GOOD CHC OF STORMS DEVELOPING IN AND NR THE
FOOTHILLS AND ACROSS THE PALMER DIVDE BY EARLY AFTN WITH ACTIVITY
SPREADING SLOWLY EASTWARD ACROSS THE PLAINS FM LATE AFTN INTO THE
EARLY EVENING HOURS. ONE THING THAT MODELS ARE NOT SHOWING IS A
DENVER CYCLONE WHICH IS A BIT SURPRISING CONSIDERING THE LOW LVL
FLOW WILL BE SELY. IF ONE DOES DVLP THE CONVERGENCE ZONE COULD END
BEING A FOCUS FOR HEAVIER RAINFALL OVER PORTIONS OF THE URBAN
CORRIDOR OR JUST TO THE EAST. WITH HIGH PW`S SOME STORMS WILL HAVE
THE POTENTIAL TO PRODUCE 1 TO 2 INCHES OF RAIN WITH LOCALLY HIGHER
AMOUNTS POSSIBLE IN A FEW SPOTS IF THE DENVER CONVERGENCE ZONE DOES
DEVELOP. AS FOR TEMPS 850-700 MB TEMPS DROP A FEW MORE DEGREES TODAY
SO READINGS WILL HOLD IN THE 80S ACROSS NERN CO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 401 AM MDT MON AUG 10 2015
LITTLE CHANGE TO THE FORECAST PACKAGE FOR THE LATTER FORECAST
PERIODS THIS TIME AROUND. MEDIUM RANGE MODELS CONTINUE INDICATING
THAT A STRONG UPPER LEVEL RIDGE WILL BUILD OVER COLORADO AND THE
FOUR CORNERS REGION THROUGH MOST OF THE WEEK. SPECIFIC HUMIDITY
FIELDS CONTINUE SHOWING HEALTHY AMOUNTS OF MOISTURE ROTATING OVER
THE STATE FROM THE SOUTH THROUGH THE FORECAST PERIOD. BUT MODEL
QPF CHARTS ARE NO LONGER SHOWING ANY PERIODS OF PARTICULARLY HEAVY
RAINFALL. MODEL SOUNDINGS FOR TUESDAY AND WEDNESDAY SHOW THAT
PRECIPITABLE WATER VALUES AROUND DENVER WILL REMAIN AT OR SLIGHTLY
ABOVE 1 INCH...WHICH MEANS THAT THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL. STORM MOTIONS ARE ALSO EXPECTED
TO BE WEAK...MEANING THAT WE WILL HAVE TO WATCH OUT FOR LOCAL
FLOODING PROBLEMS WHEN STORMS DEVELOP.
MODEL SOUNDINGS ALSO SHOW THAT THE AIRMASS WILL BE MOST UNSTABLE
ON TUESDAY...AND THEN STABILIZE LATER IN THE WEEK. THE INCREASE IN
STABILITY WILL BE DUE TO WARMING MID-LEVEL TEMPERATURES UNDER THE
CENTER OF THE SUBSIDENT HIGH PRESSURE ALOFT. THE EXPECTED PRESENCE
OF THE SUBTROPICAL MOISTURE AT MID AND UPPER LEVELS WILL MAKE IT
HARD TO COMPLETELY REMOVE THE MENION OF SHOWER ACTIVITY THOUGH.
THEREFORE...THE FORECAST WILL HAVE THE HIGHEST CHANCES OF SHOWERS
OVER THE MOUNTAINS IN THE AFTERNOONS AND EVENINGS WITH THE PLAINS
HAVING A SLIGHT CHANCE OF THUNDERSTORMS IN THE EVENINGS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 401 AM MDT MON AUG 10 2015
LIGHT DRAINAGE WINDS HAVE DEVELOPED EARLY THIS MORNING HOWEVER ONCE
MIXING OCCURS EXPECT WINDS WILL GRADUALLY BECOME MORE EARLY BY LATE
MORNING AND THEN MORE SELY BY AFTN. NEITHER THE HRRR OR RAP IS
SHOWING A DENVER CYCLONE THIS AFTN. IF ONE DOES DVLP THEN WIND
DIRECTIONS COULD END UP BEING CONSIDERABLY DIFFERENT DEPENDING ON
WHERE THE CONVERGENCE ZN SETS UP. TSTM THREAT WILL INCREASE BY
EARLY AFTN WITH SOME POTENTIAL FOR LOWER CEILINGS/VISIBILITIES IF
AIRPORT TAKES A DIRECT HIT FROM A STRONGER STORM. FURTHERMORE
CURRENT DATA SUGGESTS TSTM THREAT COULD CONTINUE INTO THE EARLY
EVENING HOURS AS WELL SO WILL HAVE TO KEEP IN AT LEAST A PROB GROUP
THRU 03Z. OVERNIGHT THERE WILL BE SOME POTENTIAL FOR STRATUS/FOG
TOWARDS MORNING BASED ON THE HI RES MODELS AS THEY SHOW A DENVER
CYCLONE NR DIA.
&&
.HYDROLOGY...
ISSUED AT 401 AM MDT MON AUG 10 2015
A FEW THUNDERSTORMS MAY DROP FROM 1 TO 2 INCHES OF RAIN IN 45
MINUTES OR LESS ALONG THE FRONT RANGE...PLAINS AND ACROSS THE
PALMER DIVIDE THIS AFTERNOON INTO THE EARLY EVENING HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...DANKERS
AVIATION...RPK
HYDROLOGY...RPK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1105 AM EDT MON AUG 10 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL PUSH FARTHER OFF THE COAST TODAY. MOISTURE
WILL INCREASE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA LATE TUESDAY AND
TUESDAY NIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE
ASSOCIATED WITH THE FRONT. DRYING WITH A DIMINISHED SHOWER CHANCE
WILL OCCUR BEHIND THE FRONT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RIDGE ALONG THE COAST WILL BE SHIFTING FARTHER OFFSHORE
THROUGH TONIGHT. AN INCREASE IN MOISTURE SHOULD OCCUR IN A
SOUTHERLY FLOW. THE MODELS INDICATE UPPER SUPPORT WILL OCCUR
THROUGH TONIGHT WITH AN H5 DIFLUENT PATTERN. ENHANCED LIFT MAY
OCCUR TONIGHT AHEAD OF SHORTWAVE TROUGH.
THE CONVECTION ALLOWING MODELS GENERALLY SHOWED SCATTERED SHOWER
AND THUNDERSTORM COVERAGE TODAY AND THIS APPEARS REASONABLE WITH
SHORTWAVE TROUGH TIMING NOT DIURNALLY FAVORABLE. THE GUIDANCE
CONSENSUS MOS SUPPORTED POPS OF 20 TO 30 PERCENT TODAY.
THE THUNDERSTORM CHANCE SHOULD INCREASE TONIGHT AHEAD OF THE NEXT
SHORTWAVE TROUGH. THE HRRR DISPLAYED CONSIDERABLE COVERAGE ABOUT
TO ENTER THE FORECAST AREA FROM THE WEST TOWARD SUNSET. THE SPC
WRF SHOWED THIS AREA DIMINISHING AS IT MOVED THROUGH THE FORECAST
AREA DURING THE 800 PM TO 100 AM TIME FRAME. FORECASTED A POP
AROUND 40 PERCENT CLOSE TO THE GUIDANCE CONSENSUS.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE TODAY.
LEANED TOWARD THE WARMER GUIDANCE BECAUSE OF EXPECTED CLOUDINESS
AND MIXING TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CONVERGENCE INTO A PRE-FRONTAL TROUGH AND COLD FRONT TUESDAY AND
TUESDAY NIGHT PLUS UPPER-LEVEL TROUGHING SHOULD LEAD TO NUMEROUS
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. WE LEANED
TOWARD THE HIGHER POP GUIDANCE. SHOWER AND THUNDERSTORM COVERAGE
MAY BE GREATEST EARLY TUESDAY AHEAD OF A MID-LEVEL SHORTWAVE
TROUGH AND AGAIN TUESDAY EVENING NEAR STRONGER CONVERGENCE JUST
AHEAD OF THE FRONT. THE MODELS INDICATE MODERATE INSTABILITY AND
PRECIPITABLE WATER OVER 2 INCHES. THUNDERSTORMS WITH DAMAGING WIND
AND EXCESSIVE RAIN WILL BE POSSIBLE. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF INDICATE UPPER TROUGHING CONTINUING OVER THE
EASTERN PART OF THE NATION THROUGH THE MEDIUM-RANGE PERIOD. THE
MODELS DISPLAY A FRONTAL SYSTEM LINGERING NEAR THE SOUTHEAST
COAST. DEEP MOISTURE APPEARS TO REMAIN SOUTH AND EAST OF THE
FORECAST AREA. THE GFS AND ECMWF MOS HAVE TEMPERATURES NEAR
CLIMATOLOGY WITH POPS 10 TO 30 PERCENT.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF SHOWER/THUNDERSTORM ACTIVITY
THIS AFTERNOON AND TONIGHT.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP ACROSS THE
AREA BY LATE AFTERNOON/EARLY THIS EVENING...BUT GIVEN LOW
CONFIDENCE IN TIMING AND AREAL COVERAGE...HAVE NOT INCLUDED
CONVECTION IN THE TAFS ATTM. WINDS WILL CONTINUE OUT OF THE SOUTH
AT AROUND 5 TO 10 KNOTS THROUGH TONIGHT...BECOMING MORE
SOUTHWESTERLY OVERNIGHT.
EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE
TUESDAY THROUGH TUESDAY NIGHT AS AN APPROACHING FRONTAL BOUNDARY
MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
744 AM EDT MON AUG 10 2015
.PREV DISCUSSION... /ISSUED 413 AM EDT MON AUG 10 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT WILL IMPACT THE CWFA IN THE SHORT TERM PORTION OF THE
FORECAST AREA. THE FRONT CURRENTLY STRETCHES FROM THE MID
MISSISSIPPI RIVER VALLEY TO THE TENNESSEE VALLEY. THE BOUNDARY WILL
SLIP SLOWLY SOUTH TODAY...AND CROSS MUCH OF THE FORECAST AREA ON
TUESDAY.
DEWPOINTS HAVE BEGUN TO CREEP UP ACROSS THE CWFA...A SIGN OF
INCREASING LOW LEVEL MOISTURE. PRECIPITATION CHANCES WILL INCREASE
TODAY AHEAD OF THE FROPA. HI-RES MODELS ARE SHOWING A RATHER
ORGANIZED LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTH ACROSS
NORTH AND CENTRAL GA THIS AFTERNOON. THE LOCAL WRF AND THE HRRR DO
DIFFER A BIT...WITH THE WRF BEING LATER WITH THE CONVECTION. HAVE
TRIED TO COMPROMISE ON TIMING. BOTH MODELS...HOWEVER...INDICATE VERY
GOOD RAIN CHANCES ACROSS NORTHERN GA TODAY. SO...HAVE RAISED POPS TO
LIKELY IN THAT REGION.
ATMOS WILL BE FAVORABLE FOR STRONG TO ISOLATED SEVERE STORMS. GOOD
SURFACE INSTABILITY WILL BE PRESENT...WITH AN ASSIST BY A SHORTWAVE
DROPPING SOUTH IN THE MID LEVEL FLOW. MODELS CURRENTLY KEEP LAPSE
RATES FAIRLY WEAK...BUT THE SHORTWAVE WILL PROVIDE SOME LIFT.
COPIOUS CLOUD COVER SHOULD HELP LIMIT SEVERE STORM COVERAGE.
THE MAIN FOCUS FOR TODAYS CONVECTION SHOULD BE ANY
OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FROM THE THUNDERSTORM
COMPLEX CURRENTLY ACROSS THE MID MISSISSIPPI RIVER VALLEY. THE
ACTUAL FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR STORMS TOMORROW.
TEMPS SHOULD BE A FEW DEGREES COOLER THAN YESTERDAYS VALUES DUE TO
THE INCREASED CLOUD COVER. TEMP/DEWPOINT VALUES REMAIN BELOW
CRITICAL THRESHOLDS FOR A HEAT ADVISORY AT THIS TIME.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE IN DECENT AGREEMENT WITH AFOREMENTIONED FRONTAL BOUNDARY
IN THE SHORT TERM LINGERING ACROSS THE SOUTHERN TIER OF THE CWA
FOR TUESDAY NIGHT INTO WEDNESDAY...THEN FINALLY PUSHING JUST SOUTH
OF THE AREA AND BECOMING MORE DIFFUSE THRU THE REST OF THE WORK
WEEK. HAVE TRENDED CHANCE TO SLIGHT POPS ACCORDINGLY AND ADVECTION
OF ABNORMALLY DRY AIR IN FROM THE NW WILL ALLOW FOR A RATHER
PLEASANT WED AND THURS WITH SLIGHTLY BELOW NORMAL HIGHS AND
RESULTANT AFTERNOON RH VALUES IN THE 40S.
FOR FRIDAY INTO THE WEEKEND...A BROAD/WEAK AREA OF LOW PRESSURE
LOOKS TO DEVELOP ACROSS THE NORTHERN GOM ALLOWING FOR SOME LOW
LEVEL MOISTURE TRANSPORT OFF THE ATLANTIC. HAVE CONTINUED TO
ADVERTISE A RETURN OF SLIGHT TO LOW END CHANCE POPS FOR PORTIONS
OF THE AREA...MAINLY FOR DIURNALLY DRIVEN CONVECTION. NO OTHER
CLEAR FORCING MECHANISM LOOKS TO BE PRESENT SO NOT EXPECTING
ANYTHING WIDESPREAD AND RATHER STAGNANT AIRMASS IN PLACE SO
DEVELOPMENT SHOULD BE TYPICAL SUMMERTIME OUTFLOW DRIVEN. TEMPS
SHOULD BE SLIGHTLY WARMER THAN MIDWEEK BUT CLOSE TO NORMAL OR
SLIGHTLY BELOW WITH ENHANCED CLOUD COVERAGE.
BAKER
&&
.AVIATION...
12Z UPDATE...
HI-RES MODELS CONTINUE TO BRING AN ORGANIZED LINE OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON. THE HRRR SEEMS TO
HAVE THE BEST HANDLE ON THE SYSTEM AND HAS HAD MORE RUN TO RUN
CONSISTENCY. WINDS WILL REMAIN ON THE WEST SIDE.
//ATL CONFIDENCE...12Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 72 89 71 / 40 40 30 30
ATLANTA 90 74 88 72 / 40 40 30 20
BLAIRSVILLE 84 67 83 63 / 60 40 30 10
CARTERSVILLE 90 71 88 68 / 60 40 30 20
COLUMBUS 93 76 91 74 / 40 30 40 40
GAINESVILLE 87 72 87 71 / 60 40 30 20
MACON 92 74 90 73 / 40 30 40 40
ROME 91 72 89 68 / 60 40 30 10
PEACHTREE CITY 91 72 89 70 / 40 30 30 30
VIDALIA 92 73 92 74 / 30 20 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
633 AM EDT MON AUG 10 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL PUSH FARTHER OFF THE COAST TODAY. MOISTURE
WILL INCREASE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA LATE TUESDAY AND
TUESDAY NIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE
ASSOCIATED WITH THE FRONT. DRYING WITH A DIMINISHED SHOWER CHANCE
WILL OCCUR BEHIND THE FRONT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RIDGE ALONG THE COAST WILL BE SHIFTING FARTHER OFFSHORE
THROUGH TONIGHT. AN INCREASE IN MOISTURE SHOULD OCCUR IN A
SOUTHERLY FLOW. THE MODELS INDICATE UPPER SUPPORT WILL OCCUR
THROUGH TONIGHT WITH AN H5 DIFLUENT PATTERN. ENHANCED LIFT MAY
OCCUR THIS MORNING AND TONIGHT AHEAD OF SHORTWAVE TROUGHS.
BELIEVE A LEAD SHORTWAVE TROUGH WAS HELPING SUPPORT THE SCATTERED
SHOWERS IN THE FORECAST AREA EARLY THIS MORNING. THE CONVECTION
ALLOWING MODELS GENERALLY SHOWED SCATTERED SHOWER AND THUNDERSTORM
COVERAGE TODAY AND THIS APPEARS REASONABLE WITH SHORTWAVE TROUGH
TIMING NOT DIURNALLY FAVORABLE. THE GUIDANCE CONSENSUS MOS
SUPPORTED POPS OF 20 TO 30 PERCENT TODAY.
THE THUNDERSTORM CHANCE SHOULD INCREASE TONIGHT AHEAD OF THE NEXT
SHORTWAVE TROUGH. THE HRRR DISPLAYED CONSIDERABLE COVERAGE ABOUT
TO ENTER THE FORECAST AREA FROM THE WEST TOWARD SUNSET. THE SPC
WRF SHOWED THIS AREA DIMINISHING AS IT MOVED THROUGH THE FORECAST
AREA DURING THE 800 PM TO 100 AM TIME FRAME. FORECASTED A POP
AROUND 40 PERCENT CLOSE TO THE GUIDANCE CONSENSUS.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE TODAY.
LEANED TOWARD THE WARMER GUIDANCE BECAUSE OF EXPECTED CLOUDINESS
AND MIXING TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CONVERGENCE INTO A PRE-FRONTAL TROUGH AND COLD FRONT TUESDAY AND
TUESDAY NIGHT PLUS UPPER-LEVEL TROUGHING SHOULD LEAD TO NUMEROUS
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. WE LEANED
TOWARD THE HIGHER POP GUIDANCE. SHOWER AND THUNDERSTORM COVERAGE
MAY BE GREATEST EARLY TUESDAY AHEAD OF A MID-LEVEL SHORTWAVE
TROUGH AND AGAIN TUESDAY EVENING NEAR STRONGER CONVERGENCE JUST
AHEAD OF THE FRONT. THE MODELS INDICATE MODERATE INSTABILITY AND
PRECIPITABLE WATER OVER 2 INCHES. THUNDERSTORMS WITH DAMAGING WIND
AND EXCESSIVE RAIN WILL BE POSSIBLE. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF INDICATE UPPER TROUGHING CONTINUING OVER THE
EASTERN PART OF THE NATION THROUGH THE MEDIUM-RANGE PERIOD. THE
MODELS DISPLAY A FRONTAL SYSTEM LINGERING NEAR THE SOUTHEAST
COAST. DEEP MOISTURE APPEARS TO REMAIN SOUTH AND EAST OF THE
FORECAST AREA. THE GFS AND ECMWF MOS HAVE TEMPERATURES NEAR
CLIMATOLOGY WITH POPS 10 TO 30 PERCENT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A FEW SHOWERS HAVE DEVELOPED OVER PORTIONS OF THE MIDLANDS AND
CSRA EARLY THIS MORNING. GIVEN LATEST RADAR TRENDS...HAVE INCLUDED
A TEMPO GROUP FOR SHOWERS FOR AGS/DNL/CAE/CUB UNTIL 13Z. CLOUDS
AND A 15 TO 20 KNOT LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
BEFORE SUNRISE. LIGHT SE WINDS EARLY BECOMING SOUTH TO SOUTHWEST 5
TO 10 KNOTS BY LATE MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP ACROSS THE
AREA BY LATE AFTERNOON/EARLY THIS EVENING...BUT GIVEN LOW
CONFIDENCE IN TIMING AND AREAL COVERAGE...HAVE NOT INCLUDED
CONVECTION IN THE TAFS ATTM.
EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE
TUESDAY THROUGH TUESDAY NIGHT AS AN APPROACHING FRONTAL BOUNDARY
MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT MON AUG 10 2015
UPDATED THE FORECAST DURING MID MORNING WITH DENSE FOG ADVISORY
ENDING AT 9 AM ACROSS NORTHERN HALF OF CWA. WILL ISSUE ANOTHER
UPDATE LATE THIS MORNING TO REMOVE MENTION OF PATCHY FOG THIS
MORNING. OTHERWISE REST OF FORECAST LOOKS ON TRACK THIS AFTERNOON.
HAVE 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS
WARM AND HUMID CONDITIONS PREVAIL WITH DEWPOINTS OF 70-75F AND
SEASONABLE HIGHS IN THE LOW TO MID 80S. A WEAK FRONTAL BOUNDARY
JUST SE OF A RANTOUL TO DECATUR TO TAYLORVILLE LINE WILL PUSH SE
ACROSS SOUTHEAST IL DURING THIS AFTERNOON GIVING ISOLATED SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF IT WHERE UNSTABLE AIRMASS
WITH CAPES OF 1500-2500 J/KG. MEANWHILE A SHORT WAVE TROF OVER SE
WI INTO IA WILL SHIFT SE INTO THE IL RIVER VALLEY LATER THIS
AFTEROON GIVING A CHANCE OF SHOWERS/THUNDESTORMS THERE AS WELL.
SPC KEEPS MARGINAL RISK OF SEVERE STORMS SE OF CWA THIS AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VSBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE
PAST HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL
DENSE FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY
DENSE OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 657 AM CDT MON AUG 10 2015
MAIN CONCERN INITIALLY WILL BE CIGS AND VSBYS IN DENSE FOG. VLIFR
AND LIFR CONDITIONS WILL AFFECT ALL BUT BMI INITIALLY, WHERE IFR
CONDITIONS PREVAIL AT 12Z. FORECAST SOUNDINGS SHOW WELL SATURATED
SURFACE LAYER AND INVERSION, SO FOG MAY LINGER FOR SEVERAL HOURS
AFTER SUNRISE. FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z THIS
MORNING WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY LATE
MORNING. SCATTERED TO BROKEN CUMULUS SHOULD REMAIN IN THE
AFTERNOON WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS
WILL BECOME NORTH-NORTHWEST THIS MORNING AT 8 TO 13 KTS.
SPOTTY SHOWERS AND STORMS MAY DEVELOP THIS AFTERNOON INTO EARLY
EVENING ALONG A TROUGH OF LOW PRESSURE PASSING FROM NW TO SE
ACROSS THE AREA. HRRR AND RAP MODELS FOCUS CHANCES MAINLY FROM PIA
AND NW 21Z-01Z, THEN DISSIPATE THE LINE OF SHOWERS. FOR NOW, WILL
USE VCSH FOR PIA AND KEEP THE OTHER TAF SITES DRY.
ANOTHER ROUND OF FOG COULD DEVELOP LATE TONIGHT, SO WE ADDED MVFR
FOG ACROSS THE BOARD AFTER 11/09Z TO TREND IN THAT DIRECTION.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
658 AM CDT MON AUG 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VSBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE
PAST HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL
DENSE FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY
DENSE OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 657 AM CDT MON AUG 10 2015
MAIN CONCERN INITIALLY WILL BE CIGS AND VSBYS IN DENSE FOG. VLIFR
AND LIFR CONDITIONS WILL AFFECT ALL BUT BMI INITIALLY, WHERE IFR
CONDITIONS PREVAIL AT 12Z. FORECAST SOUNDINGS SHOW WELL SATURATED
SURFACE LAYER AND INVERSION, SO FOG MAY LINGER FOR SEVERAL HOURS
AFTER SUNRISE. FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z THIS
MORNING WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY LATE
MORNING. SCATTERED TO BROKEN CUMULUS SHOULD REMAIN IN THE
AFTERNOON WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS
WILL BECOME NORTH-NORTHWEST THIS MORNING AT 8 TO 13 KTS.
SPOTTY SHOWERS AND STORMS MAY DEVELOP THIS AFTERNOON INTO EARLY
EVENING ALONG A TROUGH OF LOW PRESSURE PASSING FROM NW TO SE
ACROSS THE AREA. HRRR AND RAP MODELS FOCUS CHANCES MAINLY FROM PIA
AND NW 21Z-01Z, THEN DISSIPATE THE LINE OF SHOWERS. FOR NOW, WILL
USE VCSH FOR PIA AND KEEP THE OTHER TAF SITES DRY.
ANOTHER ROUND OF FOG COULD DEVELOP LATE TONIGHT, SO WE ADDED MVFR
FOG ACROSS THE BOARD AFTER 11/09Z TO TREND IN THAT DIRECTION.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR ILZ027>031-
036>038-041>043-045>051.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1118 AM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 1115 AM EDT MON AUG 10 2015
SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THIS AFTERNOON
AND WILL BECOME MORE NUMEROUS OVER NORTHEAST INDIANA AND NORTHWEST
OHIO AS A LOW PRESSURE SYSTEM MOVES ACROSS THE REGION. A FEW OF
THESE STORMS MAY PRODUCE HEAVY RAIN AND GUSTY WINDS ALONG AND EAST
OF INTERSTATE 69. HIGH PRESSURE AND DRY CONDITIONS WILL RETURN
OVERNIGHT AND PERSIST UNTIL THE END OF THE WEEK. TODAY WILL BE THE
LAST MUGGY DAY FOR A WHILE WITH HIGHS AROUND 80 DEGREES. LESS HUMID
AND SLIGHTLY COOLER CONDITIONS EXPECTED FOR THE REST OF THE WEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EDT MON AUG 10 2015
THE COMBINATION OF A WEAK MID LEVEL TROUGH AND LOW LEVEL THETAE
ADVECTION AT THE NOSE OF LOW LEVEL MOISTURE AXIS HAS ALLOWED FOR
SCATTERED SHOWER DEVELOPMENT ACROSS PORTIONS OF SOUTH CENTRAL
LOWER MICHIGAN/FAR NORTHEAST INDIANA THIS MORNING. REGIONAL AMDAR
SOUNDINGS JUST TO THE WEST DO DEPICT A RELATIVELY WARM 800-700 HPA
WHICH IS LIKELY PROVIDING SOME INHIBITION FOR SFC BASED PARCELS
ALONG ADVANCING FRONTAL BOUNDARY. AT LEAST TWO ADDITIONAL UPSTREAM
PERTURBATIONS APPEAR POISED TO TRACK ACROSS THE SOUTHERN GREAT
LAKES THIS EVENING...THE FIRST PUSHING INTO NORTHEAST ILLINOIS
CURRENTLY...WITH A SECOND UPPER SHORT WAVE ENTERING SOUTHERN
MINNESOTA. APPROACH OF THIS FIRST WAVE EARLY THIS AFTERNOON SHOULD
ALLOW FOR SOME COOLING OF AFOREMENTIONED 800-700 HPA WARM LAYER
AND A POTENTIAL OF SCATTERED SHOWER/ISOLATED THUNDERSTORM
DEVELOPMENT EVEN BEHIND INITIAL WIND SHIFT. IT STILL APPEARS AS
THOUGH MORE VIGOROUS CONVECTION SHOULD AFFECT AREAS EAST OF I-69
WHERE BETTER INSTABILITY AXIS SHOULD BE SITUATED. SEVERE THREAT
STILL APPEARS LOW BASED ON MARGINAL INSTABILITY PROFILES AND
OVERALL MODEST NATURE TO MID/UPPER FORCING. LOCALIZED HEAVIER
DOWNPOURS STILL APPAER TO BE THE MAIN THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT MON AUG 10 2015
ANOTHER "GRUNGY" DAY IN STORE FOR THE LOCAL FORECAST AREA AS BROAD
MID/UPPER LEVEL HEIGHT FALLS INDUCE MODEST SURFACE CYCLOGENESIS OVER
THE GREAT LAKES WITH A VERY MOIST/MARGINALLY UNSTABLE ENVIRONMENT IN
PLACE. THIS SETUP WILL LIKELY LEAD TO SEVERAL ROUNDS OF SPORADIC
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. ALREADY A FEW ISOLATED
SHOWERS POPPING UP ACROSS THE REGION AND SHOULD SEE THIS ACTIVITY
GRADUALLY EXPAND DURING THE DAY AS DIFFUSE SURFACE BOUNDARY
CURRENTLY OVER IOWA PUSHES EASTWARD AND CAPITALIZES ON SOME DEGREE
OF DIURNAL HEATING. LAST FEW RUNS OF HRRR (AND TO A LESSER EXTENT
THE RAP) FINALLY SEEM TO HAVE A LITTLE BETTER HANDLE ON THE CURRENT
PICTURE AND SUGGEST PRECIP WILL EXPAND IN OUR NORTHWEST COUNTIES
DURING THE LATE MORNING (~14Z) AND PUSH SOUTHEASTWARD THROUGH THE
DAY. THIS SEEMS REASONABLE BASED ON LATEST RADAR MOSAIC/SURFACE OBS
AND BACKGROUND SYNOPTIC PATTERN. HAVE THEREFORE MASSAGED POP GRIDS A
BIT TO REFLECT THIS EXPECTED EVOLUTION. MIDLEVEL LAPSE RATES DO GET
A LITTLE BETTER WITH APPROACHING TROUGH AND AMPLE LOW LEVEL MOISTURE
WILL SUPPORT AROUND 1500 J/KG OF SBCAPE IN OUR EASTERN HALF THIS
AFTERNOON DESPITE ABUNDANT CLOUD COVER. THIS SHOULD BE ENOUGH FOR
DECENT COVERAGE OF THUNDERSTORMS BUT POTENTIAL FOR STRONG UPDRAFTS
AND SEVERE WEATHER APPEARS LOW. PASSING MIDLEVEL SPEED MAX DOES
YIELD GOOD DEEP LAYER SHEAR NUMBERS BUT WIND PROFILES IN THE 0-3KM
LAYER ARE FAIRLY LIGHT AND...GIVEN LESS THAN STELLAR INSTABILITY
VALUES...SUGGEST A LOW SEVERE RISK. MAIN THREAT WOULD BE AN ISOLATED
STRONG/SEVERE DOWNBURST WHERE ANY POCKETS OF ENHANCED CAPE MANAGE TO
DEVELOP. POCKETS OF HEAVY RAIN ALSO POSSIBLE GIVEN PW VALUES AROUND
1.75 INCHES BUT RECENT DRY SPELL AND OVERALL LACKLUSTER SYNOPTIC
FORCING SUGGEST THREAT FOR WIDESPREAD FLOODING IS LOW. PRECIP
SHOULD EXIT THE CWA BY THIS EVENING WITH COOLER AND MUCH DRIER AIR
FILTERING SOUTH. AFTER A MUGGY DAY TODAY WITH HIGHS AROUND
80F...EXPECT DEWPOINTS AND LOW TEMPS TO DROP BACK INTO THE LOWER
60S OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 350 AM EDT MON AUG 10 2015
HIGH PRESSURE OVER THE UPR MIDWEST TUE WILL MOVE SE TO INDIANA
WED PROVIDING FAIR WEATHER ACROSS OUR AREA. NW FLOW ALOFT WILL
ADVECT A COOL CANADIAN AIRMASS S-SE INTO OUR AREA RESULTING IN BLO
NORMAL TEMPS THROUGH THIS TIMEFRAME. DRY WX SHOULD CONT THU AS THE
HIGH MOVES SE OF THE AREA WITH WAA ON THE BACKSIDE OF THE HIGH
RESULTING IN A LITTLE WARMER TEMPS.
A CDFNT IS EXPECTED TO DROP SLOWLY S-SE ACROSS THE GRTLKS THU NGT-
FRI NGT. UPR RIDGE AXIS OVER THE ROCKIES IS ALSO EXPECTED TO MOVE
EAST IN THIS TIMEFRAME SO A GENERAL WKNG TREND OF THE FRONT IS
EXPECTED... BUT MEDIUM RANGE MODELS IN DECENT AGREEMENT SUGGESTING
AT LEAST SOME CONVECTION MAY FORM ALONG/AHEAD OF THE FRONT SO HAVE
ADDED LOW POPS FOR LATE IN THE WORKWEEK. BY THE WEEKEND THE UPR
RIDGE AXIS SHOULD MOVE OVER OUR AREA PROVIDING DRY WX WITH ABOVE
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 555 AM EDT MON AUG 10 2015
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE IN COVERAGE
TODAY AS A MIDLEVEL TROUGH APPROACHES THE REGION AND INTERSECTS A
VERY MOIST AIRMASS. ISOLATED THUNDERSTORMS POSSIBLE THIS MORNING
BUT BETTER CHANCES STILL LOOK TO BE AT KFWA THIS AFTERNOON.
PERIODS OF MVFR CONDITIONS POSSIBLE AS WEAK FRONTAL BOUNDARY
APPROACHES THE AREA BUT LATEST HI-RES/RAPID UPDATE GUIDANCE
SUGGESTS CEILINGS WILL LIKELY REMAIN ABOVE FUEL ALTERNATE
CRITERIA. CONDITIONS WILL IMPROVE BY THIS EVENING AS FRONT EXITS
AND DRIER AIR FILTERS SOUTH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...SKIPPER
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD
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AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1120 AM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1120 AM EDT MON AUG 10 2015
14Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE CROSSING
THROUGH THE OHIO VALLEY NORTH OF KENTUCKY. A TRAILING COLD FRONT
ASSOCIATED WITH THIS IS APPROACHING THE REGION. HOWEVER...AHEAD OF
THIS BOUNDARY...AMPLE MOISTURE IS POOLING THROUGH EASTERN
KENTUCKY WITH DEWPOINTS PREDOMINATELY IN THE LOWER 70S. MORNING
BREAKS IN THE CLOUD COVER WILL HELP TO BUILD INSTABILITY THROUGH
THE CWA AS TEMPERATURES ARE CURRENTLY IN THE UPPER 70S AND LOWER
80S ON THEIR WAY TO THE MID AND UPPER 80S. THE QUESTION IS WHETHER
THE DEBRIS CLOUDS FROM THE EARLIER CONVECTION TO THE WEST WILL BE
ENOUGH TO INHIBIT THE DEVELOPMENT OF WIDESPREAD AND ORGANIZED
STORMS THROUGH THE AREA LATER THIS AFTERNOON. ALREADY A GROUP OF
SHOWERS AND DEVELOPING STORMS ARE TRACKING INTO THE CUMBERLAND
VALLEY. EXPECT THESE TO SPREAD INTO THE EARLY AFTERNOON WITH
ADDITIONAL POCKETS OF CONVECTION EXPANDING TO THE NORTH AND EAST.
THE LATEST HRRR MODEL AGREES WITH THIS SCENARIO WITH PEAK
CONVECTIVE ACTIVITY TAKING PLACE OVER THE JKL CWA BETWEEN 19 AND
23Z. HAVE UPDATED THE GRIDS WITH THIS IN MIND AS WELL AS INFUSED
THE LATEST SHORTBLEND GUIDANCE INTO THE T AND TD GRIDS. THOSE
LATER ONES WERE UPDATED TO BETTER REFLECT THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS WITH A
FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 654 AM EDT MON AUG 10 2015
WSR-88D CONTINUES TO INDICATE SOME ISOLATED SHOWERS MOVING
SOUTHEAST ACROSS PORTIONS OF EASTERN KY. EXPECT THIS MORNING
SHOWER ACTIVITY TO REMAIN LIGHT. THE HEAVIER STORMS REMAINED SOUTH
AND WEST OF THE REGION...AS MCS DIVED SOUTH TOWARD THE MORE
UNSTABLE ENVIRONMENT WHERE UPPER 70S TO LOW 80 DEWPOINTS WERE
REPORTED. STILL LOOKING AT INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS AS WE MOVE INTO THE AFTERNOON HOURS AHEAD OF A
APPROACHING COLD FRONT. SOME MINOR UPDATES TO POPS AND THEN
UPDATES TO TEMPS/DEWS/WINDS TO MATCH CURRENT CONDITIONS/TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
OVERALL MODELS REMAIN IN GOOD AGREEMENT WITH OVERARCHING SYNOPTIC
PATTERN WITH TROUGHING CONTINUE TO DEEPEN IN THE EASTERN CONUS
THROUGH THE PERIOD. THIS MORNING WE ARE BEING MET WITH A FEW
SHOWERS SPREADING SE ACROSS PORTIONS OF EASTERN KY SEEN ON WSR-
88D. THIS HAS BEEN BROUGHT ON BY UPPER LEVEL WAVE AND INCREASING
LOW LVL JET ACROSS THE OHIO/TN VALLEYS. THESE ARE DEVELOPING AHEAD
OF AN APPROACHING SURFACE LOW PRESSURE AND COLD FRONT ACROSS THE
MIDWEST THIS MORNING. WHILE WE DO HAVE SHOWERS AND PERHAPS A
ISOLATED THUNDERSTORM THIS MORNING...BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL EXIST AS WE MOVE INTO THE AFTERNOON AHEAD OF
THE COLD FRONT.
THE QUESTION IS HOW MUCH DOES ON GOING ACTIVITY AND CLOUD COVER
PLAY ON THE OVERALL DESTABILIZATION...RIGHT NOW THIS LOOKS TO
HAVE SOME AFFECTS BUT INCREASING LOW LEVEL JET AND SOME INSULATION
LOOK TO BE ENOUGH TO FIRE OF STORMS THIS AFTERNOON. THIS LOOKS
REASONABLE WITH CA MODELS SHOWING GOOD AGREEMENT OF BEST ACTIVITY
GENERALLY AFTER 18Z. WHILE SOME OF THESE STORMS COULD BE
STRONG...THINKING OVERALL SEVERE THREAT REMAINS LOW WITH SHEAR
BEING MARGINAL AT BEST. THAT SAID MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUST...AND THIS LINES UP WELL WITH SPC THINKING AND
OVERALL BROAD MARGINAL RISK. AFTER THIS SHOWER AND STORM ACTIVITY
WILL WAIN IN THE EVENING AND OVERNIGHT HOURS AS FRONT SLOWLY MOVES
EAST ACROSS THE REGION. MAINTAIN SOME INSTABILITY SHOWERS MAINLY
IN THE FAR EAST THROUGH THE DAY ON TUESDAY. OTHERWISE SOME SPOTS
ARE EXPECTED TO BEGIN THE DRYING OUT PROCESS IN THE WAKE OF THE
COLD FRONT...AS WE TRANSITION TO W/NW FLOW. THE OTHER ISSUE IS HOW
MUCH IF ANY FOG WILL BE SEEN EARLY TUESDAY GIVEN CLOUD COVER...SO
RIGHT NOW LEFT OUT OF THE FORECAST GIVEN LOWER CONFIDENCE. THAT
SAID VALLEYS AND AREAS THAT RECEIVED RAIN WILL HAVE THE BEST
CHANCES OF SEEING REASONABLE PRODUCTION.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
QUIET LONG TERM PERIOD IN STORE AS AN EXPANSIVE UPPER LEVEL RIDGE
OVER THE FOUR CORNERS REGION EXTENDS NORTHWARD INTO CENTRAL
CANADA. WHILE A TROUGH REMAINS IN PLACE OVER THE EASTERN CONUS...THE
HIGH AMPLITUDE RIDGE TO OUR WEST PLACES THE SOURCE REGION FOR OUR
AIRMASS ALOFT OVER THE PRAIRIE PROVINCES OF CANADA...SO NOT MUCH
OPPORTUNITY FOR MOISTURE RETURN. MODELS INDICATE A PIECE OF THE
UPPER TROUGH OVER THE EAST WILL RETROGRADE SOUTHWEST AND POSSIBLY
BREAK OFF INTO A WEAK CLOSED LOW OVER THE DEEP SOUTH. THIS MAY BRING
ENOUGH LOW LEVEL MOISTURE IN OFF THE ATLANTIC TO CAUSE SOME ISOLATED
DIURNAL CONVECTION OVER THE HIGHER TERRAIN OF THE SOUTHERN
APPALACHIANS AT TIMES...BUT NOT LIKELY AFFECTING OUR AREA. THE NET
RESULT SHOULD BE A DRY FORECAST WITH PLEASANT TEMPS AND HUMIDITY
MID WEEK SLOWLY MODERATING BACK TO SEASONAL NORMS BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 700 AM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL THIS MORNING ACROSS EASTERN KY...HOWEVER
SHORT DROPS TO MVFR VIS HAS BEEN SEEN IN SOME OF THE RAIN SHOWER
ACTIVITY SEEN ON WSR-88D SWEEPS. MUCH OF THE MORNING SHOULD
REMAIN VFR WITH BETTER STORM ACTIVITY REMAINING IN WESTERN END OF
THE STATE INTO TN ASSOCIATED WITH MCS. FROPA IS STILL EXPECTED TO
MOVE EASTWARD TOWARD THE REGION TODAY AND STORM ACTIVITY WILL FORM
AHEAD OF THE FRONT. OVERALL THE CONVECTIVE ALLOWING MODELS BRING
BEST CHANCES AFTER 18Z AND RIGHT NOW THINK WILL ADJUST TAF SITES
IN THAT DIRECTION...GIVEN THAT SOME SITES LIKELY HAD VCTS STARTING
TOO EARLY. AFTER THIS THE QUESTION OF HOW MUCH FOG DO WE GET IN
THE WAKE OF THE PRECIP AND FROPA...GIVEN THE UNCERTAINTY WENT WITH
JUST A GENERAL 4SM AFTER TEMPO GROUP FOR TS. OVERALL WINDS WILL
REMAIN GENERALLY LIGHT THROUGH THE PERIOD AROUND 5 TO 10
KNOTS...WITH CAVEAT OF ANY OF THE STORMS HAVE THE POTENTIAL TO
PRODUCE HIGHER GUST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1008 AM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE THIS MORNING TO FOCUS SHOWER COVERAGE ACROSS THE
SRN PIEDMONT...SCNTRL VA...AND SRN RICHMOND METRO AREAS THROUGH
THE REST OF THIS MORNING BEFORE SHOWERS DISSIPATE.
PREVIOUS DISCUSSION (651 AM)...RADAR TRENDS INDICATE SHOWERS
HOLDING TOGETHER BETTER THAN EXPECTED OVER AN INCREASINGLY MOIST
AIR MASS. LATEST RAP GUIDANCE DEPICTS WEAK VORT MAX OVER THE
REGION...PROVIDING SUBTLE FORCING OVER AN AREA OF ISENTROPIC
LIFT...HELPING DRIVE THE SHOWERS. THIS LIFT IS PROGGED TO SPREAD
NEWD ACROSS CENTRAL VA THRU MID MORNING. HIGH PRESSURE ALONG THE
COAST WILL BEGIN TO WIN OUT...HELPING ERODE THE SHOWERS AS THEY
SPREAD EAST OF INTERSTATE 95. MID LEVEL CLOUDS HAVE ALSO
OVERSPREAD THE AREA...RESULTING IN A MOSTLY CLOUDY SKY (PARTLY
CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND LATEST STATISTICAL
GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS THE PIEDMONT INTO
CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREVIOUS DISCUSSION (407 AM)...LATEST REGIONAL RADAR MOSAIC
DEPICTS AN AREA OF SHOWERS OVER THE ERN VA PIEDMONT EARLY THIS
MORNING...SLOWING SPREADING EWD. THIS IN ASSOCIATION WITH AN AREA
OF ISENTROPIC LIFT AND WEAKENING ENERGY ALOFT. EXPECT THIS AREA OF
SHOWERS TO DISSIPATE AS IT SPREADS EWD INTO THE LOCAL PIEDMONT
COUNTIES AS THE ENERGY ALOFT WEAKENS. HOWEVER...CLOUD COVER WILL
CONTINUE TO OVERSPREAD MUCH OF THE AREA THIS MORNING...RESULTING
IN A MOSTLY CLOUDY SKY. OTHERWISE...MID- LEVEL HEIGHT FALLS OVER
THE MID- ATLANTIC REGION HAS ALLOWED MOISTURE TO RETURN EARLY THIS
MORNING...WITH PWATS PROGGED AROUND 1.5 TO 1.8 INCHES AND
DEWPOINTS WARMING INTO THE MID 60S. AT THE SFC...HIGH PRESSURE HAS
ALIGNED ALONG THE COAST WITH A WARM FRONT LOCATED OVER THE OH/KY
VALLEYS. A COLD FRONT IS RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUE AFTERNOON...WHICH
WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR THUNDER.
STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED AROUND 1K
J/KG TUE AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE 20 TO 30
KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG WITH
LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TSCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTENT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTENT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD STATEMENT HAS BEEN ISSUED FOR THE BAY SIDE OF THE
LWR MD ERN SHORE THRU MIDDAY...SPECIFICALLY FOR BISHOPS HEAD WHERE
LEVELS ARE EXPECTED TO BE ABOUT A TENTH OF A FOOT BLO MINOR FLOOD
THRESHOLDS.
PREVIOUS DISCUSSION...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ656-
658.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/BMD/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR
TIDES/COASTAL FLOODING...MPR/MAS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
954 AM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE THIS MORNING TO FOCUS SHOWER COVERAGE ACROSS THE
SRN PIEDMONT...SCNTRL VA...AND SRN RICHMOND METRO AREAS THROUGH
THE REST OF THIS MORNING BEFORE SHOWERS DISSIPATE.
PREVIOUS DISCUSSION (651 AM)...RADAR TRENDS INDICATE SHOWERS
HOLDING TOGETHER BETTER THAN EXPECTED OVER AN INCREASINGLY MOIST
AIR MASS. LATEST RAP GUIDANCE DEPICTS WEAK VORT MAX OVER THE
REGION...PROVIDING SUBTLE FORCING OVER AN AREA OF ISENTROPIC
LIFT...HELPING DRIVE THE SHOWERS. THIS LIFT IS PROGGED TO SPREAD
NEWD ACROSS CENTRAL VA THRU MID MORNING. HIGH PRESSURE ALONG THE
COAST WILL BEGIN TO WIN OUT...HELPING ERODE THE SHOWERS AS THEY
SPREAD EAST OF INTERSTATE 95. MID LEVEL CLOUDS HAVE ALSO
OVERSPREAD THE AREA...RESULTING IN A MOSTLY CLOUDY SKY (PARTLY
CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND LATEST STATISTICAL
GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS THE PIEDMONT INTO
CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREVIOUS DISCUSSION (407 AM)...LATEST REGIONAL RADAR MOSAIC
DEPICTS AN AREA OF SHOWERS OVER THE ERN VA PIEDMONT EARLY THIS
MORNING...SLOWING SPREADING EWD. THIS IN ASSOCIATION WITH AN AREA
OF ISENTROPIC LIFT AND WEAKENING ENERGY ALOFT. EXPECT THIS AREA OF
SHOWERS TO DISSIPATE AS IT SPREADS EWD INTO THE LOCAL PIEDMONT
COUNTIES AS THE ENERGY ALOFT WEAKENS. HOWEVER...CLOUD COVER WILL
CONTINUE TO OVERSPREAD MUCH OF THE AREA THIS MORNING...RESULTING
IN A MOSTLY CLOUDY SKY. OTHERWISE...MID- LEVEL HEIGHT FALLS OVER
THE MID- ATLANTIC REGION HAS ALLOWED MOISTURE TO RETURN EARLY THIS
MORNING...WITH PWATS PROGGED AROUND 1.5 TO 1.8 INCHES AND
DEWPOINTS WARMING INTO THE MID 60S. AT THE SFC...HIGH PRESSURE HAS
ALIGNED ALONG THE COAST WITH A WARM FRONT LOCATED OVER THE OH/KY
VALLEYS. A COLD FRONT IS RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUE AFTERNOON...WHICH
WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR THUNDER.
STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED AROUND 1K
J/KG TUE AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE 20 TO 30
KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG WITH
LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TSCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTENT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTENT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ656-
658.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/BMD/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR
TIDES/COASTAL FLOODING...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
651 AM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...
RADAR TRENDS INDICATE SHOWERS HOLDING TOGETHER BETTER THAN
EXPECTED OVER AN INCREASINGLY MOIST AIR MASS. LATEST RAP GUIDANCE
DEPICTS WEAK VORT MAX OVER THE REGION...PROVIDING SUBTLE FORCING
OVER AN AREA OF ISENTROPIC LIFT...HELPING DRIVE THE SHOWERS. THIS
LIFT IS PROGGED TO SPREAD NEWD ACROSS CENTRAL VA THRU MID MORNING.
HIGH PRESSURE ALONG THE COAST WILL BEGIN TO WIN OUT...HELPING
ERODE THE SHOWERS AS THEY SPREAD EAST OF INTERSTATE 95. MID LEVEL
CLOUDS HAVE ALSO OVERSPREAD THE AREA...RESULTING IN A MOSTLY
CLOUDY SKY (PARTLY CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND
LATEST STATISTICAL GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS
THE PIEDMONT INTO CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREV DISCUSSION...
LATEST REGIONAL RADAR MOSAIC DEPICTS AN AREA OF SHOWERS OVER THE
ERN VA PIEDMONT EARLY THIS MORNING...SLOWING SPREADING EWD. THIS
IN ASSOCIATION WITH AN AREA OF ISENTROPIC LIFT AND WEAKENING
ENERGY ALOFT. EXPECT THIS AREA OF SHOWERS TO DISSIPATE AS IT
SPREADS EWD INTO THE LOCAL PIEDMONT COUNTIES AS THE ENERGY ALOFT
WEAKENS. HOWEVER...CLOUD COVER WILL CONTINUE TO OVERSPREAD MUCH OF
THE AREA THIS MORNING...RESULTING IN A MOSTLY CLOUDY SKY.
OTHERWISE...MID- LEVEL HEIGHT FALLS OVER THE MID- ATLANTIC REGION
HAS ALLOWED MOISTURE TO RETURN EARLY THIS MORNING...WITH PWATS
PROGGED AROUND 1.5 TO 1.8 INCHES AND DEWPOINTS WARMING INTO THE
MID 60S. AT THE SFC...HIGH PRESSURE HAS ALIGNED ALONG THE COAST
WITH A WARM FRONT LOCATED OVER THE OH/KY VALLEYS. A COLD FRONT IS
RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUES
AFTERNOON...WHICH WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR
THUNDER. STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED
AROUND 1K J/KG TUES AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE
20 TO 30 KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG
WITH LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTANT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTANT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ656-
658.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 733 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT THAT HAS PASSED...VFR CONDITIONS SHOULD
PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX/KSAW. THERE MAY BE A BRIEF
PERIOD OF HIGH MVFR CIGS THIS MORNING AS DAYTIME HEATING LEADS TO
CUMULUS DEVELOPMENT...AND THEN NEAR OR JUST AFTER THIS FCST
PERIOD...THERE ARE SOME INDICATIONS THAT LOW CLOUDS (LOW MVFR
CIGS/PERHAPS IFR) MAY DEVELOP...MAINLY AT KSAW. AN APPROACHING
DISTURBANCE WILL GENERATE SHOWERS NW OF LAKE SUPERIOR TODAY. SOME OF
THESE SHOWERS MAY BE ABLE TO REACH UPPER MI LATE THIS AFTN/EARLY
THIS EVENING BEFORE DISSIPATING. POTENTIAL OF THESE SHRA REACHING
ANY OF THE TERMINALS (KCMX IN PARTICULAR) IS TOO LOW TO INCLUDE A
MENTION IN FCST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1037 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1037 AM CDT MON AUG 10 2015
UPDATED THE FORECAST THROUGH AROUND MIDNIGHT...FOCUSING ON PCPN
CHANCES AND CLOUD COVER. LATEST MODEL SOUNDINGS AND HRRR RUNS
SUGGEST THERE WILL BE SCT/BKN CUMULUS ACROSS MUCH OF THE FORECAST
AREA BY EARLY THIS AFTERNOON...SO EXPANDED CLOUD COVER. THE LATEST
NAM12/SREF/GFS/HRRR INDICATED THE NORTHERN AND SE FORECAST AREA
COULD GET ISOLATED/SCATTERED SHOWERS AND STORMS THIS AFTERNOON AND
EARLY EVENING...SO INCREASED AND EXPANDED COVERAGE OF PCPN
CHANCES.
THERE MAY BE A THREAT FOR ISOLATED STRONG STORMS IN THE COOK
COUNTY AREA OF THE ARROWHEAD THIS AFTERNOON AND EARLY EVENING. THE
NAM12 AND GFS SOUNDINGS FOR THE HIGHER TERRAIN OF THE ARROWHEAD
INDICATE MUCAPE COULD BUILD TO AROUND 1000 J/KG BY THE MIDDLE OF
THE AFTERNOON...AND THERE WOULD BE ABOUT 30 TO 35 KNOTS OF DEEP
LAYER WIND SHEAR. ALSO...FREEZING LEVELS WILL BE RELATIVELY LOW IN
THE HIGHER TERRAIN...ABOUT 9000 FT. THEREFORE...WOULD NOT BE
SURPRISED BY ISOLATED STORMS CAPABLE OF PRODUCING SMALL HAIL AND
GUSTY WINDS.
UPDATE ISSUED AT 612 AM CDT MON AUG 10 2015
PATCHY FOG WAS DOTTING THE LANDSCAPE...BUT SHOULD BURN OFF
QUICKLY. STILL ANTICIPATING SHOWERS AND STORMS WITH THE SHORTWAVE
TROF SET TO CLIP THE ARROWHEAD TODAY. LOWERED THE POPS IN NW WI A
BIT AS THE TROF STAYS A BIT FURTHER EAST.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
A SFC LOW CENTER WAS MOVING THROUGH EASTERN LAKE SUPERIOR AT 07Z
WITH ITS ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH NW WI. AREAS OF
FOG HAD FORMED ONCE AGAIN ACROSS MUCH OF THE REGION. EXPECT THE FOG
TO LINGER UNTIL 14Z. AS THE FRONT EXITS NW WI...HIGH PRESSURE BUILDS
ACROSS THE AREA. HOWEVER...AN UPPER LEVEL SHORTWAVE TROF WILL REACH
THE INTERNATIONAL BORDER BY 18Z AND PROCEED ACROSS THE ARROWHEAD AND
OVER LAKE SUPERIOR. SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN
TO AFFECT THE ARROWHEAD WWD TO NEAR CDD AT 15Z. STORMS WILL
PERCOLATE OVER THE ARROWHEAD THROUGH THE AFTERNOON WITH SOME STORM
DEVELOPMENT IN NW WI IN THE AFTERNOON.
THE SHORTWAVE TROF REACHES NORTHERN LOWER MICHIGAN BY 06Z TUESDAY.
ONE MORE IMPULSE WILL CLIP THE ARROWHEAD BEHIND THE TROF AND RESULT
IN SOME ISOLD SHOWERS FROM CKC TO GRAND PORTAGE. THIS ACTIVITY WILL
DIMINISH BY 03Z AS FORCING MOVES EAST AND SFC RIDGING COVERS THE
AREA. THE SFC RIDGING PERSISTS THROUGH TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
WARMER MID-WEEK WITH HIGHS IN THE LOW TO MID 80S ACROSS THE
REGION...THEN NOT AS HOT BUT STILL ABOVE NORMAL THROUGH SATURDAY
WITH HIGHS IN THE UPPER 70S TO LOW 80S. TWO MAIN PERIODS OF POSSIBLE
PRECIPITATION...ONE ON WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT
SWEEPS THROUGH FROM NORTHWEST TO SOUTHEAST...THEN AGAIN SATURDAY
NIGHT INTO SUNDAY AS ANOTHER COLD FRONT MOVES THROUGH. SOME
UNCERTAINTY EXISTS WITH THE TIMING OF THE LATE WEEKEND SYSTEM...BUT
IN GENERAL HAVE AN AVERAGE LEVEL OF CONFIDENCE FOR THE FORECAST.
ON THE SYNOPTIC SCALE A UPPER LEVEL RIDGE CENTERED OVER THE HIGH
PLAINS WILL GRADUALLY DRIFT WESTWARD TOWARDS THE FOUR CORNERS
THROUGH THE REST OF THE WORK WEEK...LEADING TO NORTHWEST FLOW ALOFT
LOCALLY. AHEAD OF A COLD FRONT/MID LEVEL DISTURBANCE SOUTHWESTERLY
WINDS COULD BECOME BREEZY WITH STRONG WARM AIR ADVECTION LEADING TO
PROBABLY THE WARMEST DAY OF THE FORECAST PERIOD. THERE IS A WEAK MID-
LEVEL IMPULSES IN THE NORTHWESTERLY FLOW WITH AN ASSOCIATED SFC LOW
THAT MOVES ACROSS NORTHWEST MINNESOTA INTO NORTHERN WISCONSIN LATE
WEDNESDAY INTO THURSDAY. THIS WILL BE SUPPORTED BY A 60-80 KT UPPER
LEVEL JET STREAK OVER THE UPPER MISSISSIPPI VALLEY...POSSIBLY
PEAKING UP TO 100 KTS IN STRENGTH OVER CENTRAL MINNESOTA. MODEL
SOUNDINGS DEPICT MODEST MID-LEVEL LAPSE RATES TO SUPPORT
THUNDERSTORMS...AND THE STRONG WINDS ALOFT WILL RESULT IN 35-45 KTS
DEEP LAYER SHEAR SUPPORTIVE OF POSSIBLY A FEW STRONG STORMS
OVERNIGHT INTO THURSDAY. COVERAGE OF STORMS MAY BE LIMITED GIVEN
ELEVATED NATURE AND DEPENDENCE ON UPSTREAM CONVECTION
EVOLUTION...BUT IN GENERAL THIS PERIOD LOOKS GOOD FOR
ISOLATED/SCATTERED STORMS.
FRIDAY/SATURDAY A HIGH PRESSURE OVER SOUTHERN SASKATCHEWAN/MANITOBA
DRIFTS INTO THE NORTHERN PLAINS THEN EAST ACROSS THE UPPER GREAT
LAKES RESULTING IN SUNNY SKIES AND SEASONABLE TO JUST ABOVE NORMAL
TEMPERATURES...UPPER 70S TO MID 80S. LATE SATURDAY INTO SUNDAY AN
UPPER LOW ENTERING BRITISH COLUMBIA WILL ABSORB THE ENERGY FROM AN
UPPER LOW OFF THE COAST OF THE PACIFIC NORTHWEST...DEEPENING INTO AN
UPPER LOW/TROUGH AS IT CROSSES THE CANADIAN PRAIRIE. A SECONDARY SFC
LOW/LEE TROUGH WILL DEVELOP OVER THE NORTHERN PLAINS ON SATURDAY
ALONG A COLD FRONT EXTENDING FROM NEAR THE MAIN SFC LOW IN SOUTHERN
CANADA INTO THE CENTRAL PLAINS. GUIDANCE IS IN FAIRLY REMARKABLE
AGREEMENT FOR THIS TIME RANGE...WITH ECMWF/GFS/GEM DEPICTING A
STRONG COLD FRONT IN THE EASTERN DAKOTAS/FAR WESTERN MINNESOTA
AROUND 00Z SUNDAY /SAT NIGHT/ PROGRESSING EASTWARD...THOUGH FROM
THERE MODEL SOLUTIONS DIVERGE. PRECIP CHANCES LOOK FAIRLY HIGH
REGARDLESS OF SPECIFICS. MOISTURE CONTENT WITH THIS SYSTEM MAY BE ON
THE HIGH SIDE GIVEN THE PACIFIC INFLUENCES. COOLER TEMPERATURES
EXPECTED IN WAKE OF THIS FRONT WITH HIGHS NEAR OR SLIGHTLY BELOW
SEASONABLE...IN THE LOW TO MID 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 647 AM CDT MON AUG 10 2015
WITH MINOR EXCEPTIONS...VFR CONDITIONS ARE EXPECTED THROUGH THE
TAF PERIOD THROUGHOUT THE REGION. PATCHY FOG RESULTING IN IFR
CONDITIONS AT HYR THIS MORNING BUT WILL LIFT AND CLEAR OUT OVER
THE NEXT HOUR. OTHERWISE EXPECTING SCATTERED/BROKEN 4-5KFT CLOUD
DECK TO DEVELOP THIS AFTERNOON WITH AN ISOLATED SHOWER POSSIBLE AT
HIB AND INL. OVERNIGHT TONIGHT SKIES GRADUALLY CLEAR OUT WITH
PATCHY FOG AGAIN POSSIBLE...FELT MOST CONFIDENT FOR HIB SO
INCLUDED A MENTION OF MVFR VISIBILITY LATE TONIGHT. OTHER SITES
MAY SEE FOG BUT CHANCES SEEM TOO LOW TO INCLUDE IN THIS TAF
ISSUANCE GIVEN THE COVERAGE OF FOG LAST NIGHT WAS A BIT LESS THAN
ORIGINALLY ANTICIPATED. WINDS LIGHT OUT OF THE NORTH-
NORTHWEST...WITH A FEW GUSTS TO AROUND 17 KTS POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 77 57 75 59 / 20 10 0 10
INL 74 52 77 56 / 20 10 0 10
BRD 79 55 80 56 / 0 0 0 0
HYR 77 55 76 53 / 20 20 0 10
ASX 76 57 73 54 / 20 20 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
940 AM CDT AUG 10 2015
.UPDATE...LATEST SATELLITE IMAGERY WAS SHOWING A WEAKENING MCS
ASSOCIATED WITH A SHORT WAVE OVER THE MIDSOUTH. IT HAD SENT A DRY
OUTFLOW BOUNDARY INTO OUR NORTHERN COUNTIES AS OF MID MORNING. THE
BOUNDARY WILL BE MOVING INTO A CAPPED REGION WITH THE STRONG
SUBTROPICAL RIDGE CENTERED OVER THE WESTERN ARKLATEX. IT SHOULD
LIMIT THE STRONG THUNDERSTORM POTENTIAL FOR THIS AFTERNOON. WILL
MONITOR THE BOUNDARY AS IT MOVES THROUGH THE REGION FOR ANY GOOD CU
FIELD CONVERGENCE ON SATELLITE. IT WILL BE ANOTHER HOT DAY. THE
BLOWOFF FROM THE MCS MAY HAMPER TEMPS SLIGHTLY IN THE
NORTHEAST...BUT WILL HOLD ONTO THE UPPER 90S IN THAT AREA. TEMPS
HAVE ALREADY HIT 90 AT JAN AS OF 920 AM. CURRENT POPS LOOK TO BE ON
TRACK. THE HRRR HIRES DEVELOPS SOME DECENT CONVECTIVE COVERAGE FOR
THIS AFTERNOON EAST OF MS RIVER WITH THE OUTFLOW BOUNDARY MOVING
THROUGH. SO WITH THAT IN MIND WILL MAKE NO CHANGES TO CURRENT
FORECAST TEMPS AND POPS./17/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE DAY AT MOST
TERMINALS. ISOLATED TO SCATTERED STORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON, MOST LIKELY TO BE AROUND GTR, JAN/HKS, MEI, AND HBG/PIB
THROUGH EARLY EVENING. BRIEF CIG/VISBY REDUCTIONS DUE TO +RA AND
GUSTY WINDS ARE POSSIBLE WITH THE STORMS. LATER TONIGHT, A SHORT
PERIOD OF PATCHY FOG IS POSSIBLE AROUND DAYBREAK, MAINLY AT SITES
ALONG AND SOUTH OF I-20. /DL/
&&
./PREVIOUS DISCUSSION...529 AM CDT MON AUG 10 2015
.DISCUSSION...
TODAY THROUGH TUESDAY NIGHT...
A STRONG SUBTROPICAL RIDGE CENTERED OVER THE ARKLATEX REGION...
SUPPORTS ANOTHER DAY OF EXCESSIVE HEAT ACROSS THE ARKLAMISS WITH
H850 TEMPERATURES EXPECTED TO PEAK AROUND 25 DEG C...BUT MESOSCALE
INFLUENCES RAISE UNCERTAINTY REGARDING THE EXACT DURATION/INTENSITY
OF TODAY`S HEAT EVENT. A SIGNIFICANT SHORTWAVE TROUGH MOVING THROUGH
THE MID MS VALLEY REGION HAS INITIATED A MESOSCALE CONVECTIVE
SYSTEM THAT IS MOVING SOUTHEAST INTO NE AR/WRN TN. EXTRAPOLATION OF
THE OUTFLOW BOUNDARY ASSOCIATED WITH THIS MCS BRINGS IT TO THE HWY
82 CORRIDOR LATE THIS MORNING...AND RECENT RUNS OF THE HRRR HAVE A
GOOD HANDLE ON THIS ASSUMING CURRENT TIMING IS MAINTAINED.
PER HRRR GUIDANCE...THE DENSITY OF THE OUTFLOW WILL BE SUFFICIENT
FOR IT TO CONTINUE MOVING SOUTHWARD THROUGH THE ENTIRE AREA BY LATE
AFTN...HOWEVER IT WILL BE MOVING INTO AND AIRMASS THAT IS SOMEWHAT
CAPPED AND THIS COULD LIMIT OVERALL THUNDERSTORM POTENTIAL. STORM
DEVELOPMENT AND INTENSITY WILL BE GOVERNED BY HOW MUCH DESTABILIZATION
CAN TAKE PLACE PRECEDING THE FAST-MOVING BOUNDARY. THE NEW SPC SSEO
IS HINTING AT A GREATER THREAT FOR STORMS OVER EASTERN/SOUTHERN MS
LATE THIS AFTN/EVNG...BUT THE TIMING COULD BE TOO SLOW. WILL BE
MONITORING TRENDS TO POTENTIALLY ADD A LIMITED THREAT FOR SEVERE
STORMS FOR THIS AFTN/EVNG...ESPECIALLY IF THE BOUNDARY SLOWS DOWN
SOME.
ASIDE FROM THE STORM POTENTIAL TODAY...THE BOUNDARY WILL ACT TO
DISRUPT HEATING AND COULD HELP TO MITIGATE OVERALL HEAT STRESS IF THE
AIRMASS IS UNABLE TO RECOVER AND HEAT BACK UP IN THE WAKE OF THE
BOUNDARY. CURRENT INDICATIONS IN THE HRRR ARE THAT RE- HEATING SO TO
SPEAK WILL TAKE PLACE OVER NORTH CENTRAL/NE MS...BUT LOCATIONS
FARTHER SOUTH/WEST MAY SEE A PRE-MATURE ENDING TO THE DIURNAL
TEMPERATURE TREND THAT COULD RESULT IN HIGH TEMPERATURES/HEAT INDICES
THAT ARE A LITTLE LESS THAN PREVIOUSLY EXPECTED.
THE FORECAST FOR TUESDAY LARGELY HINGES ON TODAY AND THIS EVENING`S
CONVECTIVE EVOLUTION. IT SHOULD BE THE LAST DAY OF DANGEROUS HEAT IN
THIS EPISODE WITH GREATEST CONFIDENCE FOR HIGHER HEAT INDICES MAINLY
ALONG/S OF THE I-20 CORRIDOR. CONFIDENCE IS HIGH ENOUGH TO WARRANT
ISSUANCE OF A HEAT ADVISORY...BUT THERE IS SOME MARGINAL POTENTIAL
THAT AN EXCESSIVE HEAT WARNING COULD BECOME NECESSARY OVER PORTIONS
OF NE LA/SW MS. CONCERNING STORM POTENTIAL...FOR NOW HAVE STUCK WITH
THE IDEA THAT STORMS TODAY WILL LIMIT TUESDAY`S CONVECTIVE
DEVELOPMENT TO MAINLY ERN/SRN MS AHEAD OF AN APPROACHING FRONT AND
THE LEADING EDGE OF MUCH DRIER AIR. IT IS POSSIBLE THAT A MARGINAL
THREAT FOR SEVERE STORMS WILL EXIST DEPENDING ON THE AMOUNT OF
DESTABILIZATION. /EC/
WEDNESDAY THROUGH NEXT SUNDAY...
UNFORTUNATELY THROUGHOUT THE CURRENT LONG TERM PORTION OF THE
FORECAST...IT APPEARS THERE`S VERY LITTLE HOPE IN THE WAY OF GETTING
SOME MUCH NEEDED RAINFALL OVER THE REGION. HOWEVER...THE "SILVER
LINING" DURING THE PERIOD WILL BE FOUND IN GETTING SOME RELIEF FROM
THE OPPRESSIVE HEAT THAT`S PLAGUED THE FORECAST AREA IN RECENT
DAYS/WEEKS.
THE FORECAST AREA WILL BECOME FIXED BETWEEN AN UPPER TROUGH OVER THE
EAST COAST OF THE UNITED STATES AND THE STUBBORN UPPER RIDGE
CENTERED NEAR THE FOUR CORNERS REGION. NORTHERLY FLOW ALOFT AND AT
THE SURFACE THROUGH MUCH OF THE WEEK WILL ADVECT DRIER AIR INTO THE
REGION. WHILE HIGHS TOP OUT IN THE LOW TO MIDDLE 90S...THE
NOTICEABLY DRIER AIR WILL HELP TO MAKE FOR MORE TOLERABLE CONDITIONS
EACH AFTERNOON...AS WELL AS OVERNIGHT AS LOWS FALL INTO THE 60S AND
70S. AS EXPECTED THROUGH...DEW POINTS WILL MODERATE UP SLIGHTLY
OVER THE WEEKEND...AND THE CHANCES OF AT LEAST SOME ISOLATED
CONVECTION RETURNING TO THE FORECAST SATURDAY AND SUNDAY. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 102 77 99 75 / 30 31 32 21
MERIDIAN 100 73 94 74 / 23 42 43 29
VICKSBURG 103 77 99 73 / 22 18 23 15
HATTIESBURG 100 76 98 76 / 20 17 49 42
NATCHEZ 101 78 98 75 / 27 16 33 20
GREENVILLE 101 77 96 73 / 12 18 7 7
GREENWOOD 100 75 95 72 / 24 28 15 8
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MSZ018-
019-025>066-072>074.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
MSZ040>043-047>066-072>074.
LA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
LAZ007>009-015-016-023>026.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
LAZ007>009-015-016-023>026.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR ARZ074-
075.
&&
$$
EC/19/
AREA FORECAST DISCUSSION
NWS JACKSON MS
529 AM CDT MON AUG 10 2015
.DISCUSSION...
TODAY THROUGH TUESDAY NIGHT...
A STRONG SUBTROPICAL RIDGE CENTERED OVER THE ARKLATEX REGION...
SUPPORTS ANOTHER DAY OF EXCESSIVE HEAT ACROSS THE ARKLAMISS WITH
H850 TEMPERATURES EXPECTED TO PEAK AROUND 25 DEG C...BUT MESOSCALE
INFLUENCES RAISE UNCERTAINTY REGARDING THE EXACT DURATION/INTENSITY
OF TODAY`S HEAT EVENT. A SIGNIFICANT SHORTWAVE TROUGH MOVING THROUGH
THE MID MS VALLEY REGION HAS INITIATED A MESOSCALE CONVECTIVE
SYSTEM THAT IS MOVING SOUTHEAST INTO NE AR/WRN TN. EXTRAPOLATION OF
THE OUTFLOW BOUNDARY ASSOCIATED WITH THIS MCS BRINGS IT TO THE HWY
82 CORRIDOR LATE THIS MORNING...AND RECENT RUNS OF THE HRRR HAVE A
GOOD HANDLE ON THIS ASSUMING CURRENT TIMING IS MAINTAINED.
PER HRRR GUIDANCE...THE DENSITY OF THE OUTFLOW WILL BE SUFFICIENT
FOR IT TO CONTINUE MOVING SOUTHWARD THROUGH THE ENTIRE AREA BY LATE
AFTN...HOWEVER IT WILL BE MOVING INTO AND AIRMASS THAT IS SOMEWHAT
CAPPED AND THIS COULD LIMIT OVERALL THUNDERSTORM POTENTIAL. STORM
DEVELOPMENT AND INTENSITY WILL BE GOVERNED BY HOW MUCH DESTABILIZATION
CAN TAKE PLACE PRECEDING THE FAST-MOVING BOUNDARY. THE NEW SPC SSEO
IS HINTING AT A GREATER THREAT FOR STORMS OVER EASTERN/SOUTHERN MS
LATE THIS AFTN/EVNG...BUT THE TIMING COULD BE TOO SLOW. WILL BE
MONITORING TRENDS TO POTENTIALLY ADD A LIMITED THREAT FOR SEVERE
STORMS FOR THIS AFTN/EVNG...ESPECIALLY IF THE BOUNDARY SLOWS DOWN
SOME.
ASIDE FROM THE STORM POTENTIAL TODAY...THE BOUNDARY WILL ACT TO
DISRUPT HEATING AND COULD HELP TO MITIGATE OVERALL HEAT STRESS IF THE
AIRMASS IS UNABLE TO RECOVER AND HEAT BACK UP IN THE WAKE OF THE
BOUNDARY. CURRENT INDICATIONS IN THE HRRR ARE THAT RE- HEATING SO TO
SPEAK WILL TAKE PLACE OVER NORTH CENTRAL/NE MS...BUT LOCATIONS
FARTHER SOUTH/WEST MAY SEE A PRE-MATURE ENDING TO THE DIURNAL
TEMPERATURE TREND THAT COULD RESULT IN HIGH TEMPERATURES/HEAT INDICES
THAT ARE A LITTLE LESS THAN PREVIOUSLY EXPECTED.
THE FORECAST FOR TUESDAY LARGELY HINGES ON TODAY AND THIS EVENING`S
CONVECTIVE EVOLUTION. IT SHOULD BE THE LAST DAY OF DANGEROUS HEAT IN
THIS EPISODE WITH GREATEST CONFIDENCE FOR HIGHER HEAT INDICES MAINLY
ALONG/S OF THE I-20 CORRIDOR. CONFIDENCE IS HIGH ENOUGH TO WARRANT
ISSUANCE OF A HEAT ADVISORY...BUT THERE IS SOME MARGINAL POTENTIAL
THAT AN EXCESSIVE HEAT WARNING COULD BECOME NECESSARY OVER PORTIONS
OF NE LA/SW MS. CONCERNING STORM POTENTIAL...FOR NOW HAVE STUCK WITH
THE IDEA THAT STORMS TODAY WILL LIMIT TUESDAY`S CONVECTIVE
DEVELOPMENT TO MAINLY ERN/SRN MS AHEAD OF AN APPROACHING FRONT AND
THE LEADING EDGE OF MUCH DRIER AIR. IT IS POSSIBLE THAT A MARGINAL
THREAT FOR SEVERE STORMS WILL EXIST DEPENDING ON THE AMOUNT OF
DESTABILIZATION. /EC/
WEDNESDAY THROUGH NEXT SUNDAY...
UNFORTUNATELY THROUGHOUT THE CURRENT LONG TERM PORTION OF THE
FORECAST...IT APPEARS THERE`S VERY LITTLE HOPE IN THE WAY OF GETTING
SOME MUCH NEEDED RAINFALL OVER THE REGION. HOWEVER...THE "SILVER
LINING" DURING THE PERIOD WILL BE FOUND IN GETTING SOME RELIEF FROM
THE OPPRESSIVE HEAT THAT`S PLAGUED THE FORECAST AREA IN RECENT
DAYS/WEEKS.
THE FORECAST AREA WILL BECOME FIXED BETWEEN AN UPPER TROUGH OVER THE
EAST COAST OF THE UNITED STATES AND THE STUBBORN UPPER RIDGE
CENTERED NEAR THE FOUR CORNERS REGION. NORTHERLY FLOW ALOFT AND AT
THE SURFACE THROUGH MUCH OF THE WEEK WILL ADVECT DRIER AIR INTO THE
REGION. WHILE HIGHS TOP OUT IN THE LOW TO MIDDLE 90S...THE
NOTICEABLY DRIER AIR WILL HELP TO MAKE FOR MORE TOLERABLE CONDITIONS
EACH AFTERNOON...AS WELL AS OVERNIGHT AS LOWS FALL INTO THE 60S AND
70S. AS EXPECTED THROUGH...DEW POINTS WILL MODERATE UP SLIGHTLY
OVER THE WEEKEND...AND THE CHANCES OF AT LEAST SOME ISOLATED
CONVECTION RETURNING TO THE FORECAST SATURDAY AND SUNDAY. /19/
&&
.AVIATION...VFR CONDITIONS WILL BE THE GENERAL RULE TODAY THROUGH
TONIGHT. THE EXCEPTIONS WILL BE A MIX OF HAZE/MIST EARLY THIS MORNING
THAT MAY RESULT IN OCCASIONAL MVFR VSBYS...AND ANY TSRA ACTIVITY THAT
DEVELOPS IN ASSOCIATION WITH AN APPROACHING OUTFLOW
BOUNDARY...ESPECIALLY IN THE GTR AREA. CURRENT EXTRAPOLATION BRINGS
THE BOUNDARY TO VICINITY OF GTR BY AROUND 15Z...BUT THINKING IT WILL
SLOW DOWN SOME AND DELAY TIMING TO MORE OF THE AFTN/EVNG. /EC
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 102 77 99 75 / 30 31 32 21
MERIDIAN 100 73 94 74 / 23 42 43 29
VICKSBURG 103 77 99 73 / 22 18 23 15
HATTIESBURG 100 76 98 76 / 20 17 49 42
NATCHEZ 101 78 98 75 / 27 16 33 20
GREENVILLE 101 77 96 73 / 12 18 7 7
GREENWOOD 100 75 95 72 / 24 28 15 8
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MSZ018-
019-025>066-072>074.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
MSZ040>043-047>066-072>074.
LA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
LAZ007>009-015-016-023>026.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
LAZ007>009-015-016-023>026.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR ARZ074-
075.
&&
$$
EC/19/
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
615 AM CDT MON AUG 10 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 10 2015
EXPECT A FEW SHOWERS OR THUNDERSTORMS TO LINGER INTO EARLY THIS
EVENING, BUT SHOULD BE GONE BEFORE MIDNIGHT. DRIER AIR IS FORECAST
TO BUILD ACROSS THE AREA BEHIND THE FRONT TONIGHT AND TUESAY...AND
LAST AT LEAST THROUGH THE END OF THE WEEK WITH DEWPOINT
TEMPERATURES DROPPING INTO THE 60S. A HIGH AMPLITUDE UPPER LEVEL
PATTERN LOCKS THE DRY LOW LEVEL RIDGE OVER THE MISSISSIPPI VALLEY,
SO PRECIPITATION CHANCES ARE VIRTUALLY NIL. THIS SHOULD MAKE FOR
RELATIVELY COMFORTABLE WEATHER FOR WHAT ARE TYPICALLY THE DOG-DAYS
OF SUMMER WITH HIGHS NEAR OR A FEW DEGREES BELOW NORMAL IN THE MID
TO UPPER 80S AND LOWS WELL BELOW NORMAL IN THE 60S.
CARNEY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 611 AM CDT MON AUG 10 2015
MAIN AREA OF CONVECTION REMAINS SOUTH OF TERMINALS FROM NEAR LAKE
OF THE OZARKS TO BOOTHEEL OF MISSOURI. COLD FRONT JUST NOW
CROSSING MISSOURI/IOWA STATE LINE AND WILL CONTINUE TO MOVE SOUTH
ACROSS THE AREA THIS MORNING. COULD SEE SOME SHOWERS AND STORMS
DEVELOP ALONG THIS BOUNDARY TODAY...BUT COVERAGE IS EXPECTED TO BE
ISOLATED TO WIDELY SCATTERED AND THEREFORE IS LEFT OUT OF TERMINAL
FORECAST AT THIS TIME. LIGHT SOUTH WIND WILL BECOME NORTHERLY
BEHIND THE FRONT. SOME IFR FOG AND STRATUS EARLY THIS MORNING
SHOULD IMPROVE THROUGH THE MORNING WITH MOSTLY CLEAR CONDITIONS
EXPECTED THIS EVENING AS HIGH PRESSURE MOVES INTO THE REGION.
SPECIFICS FOR KSTL:
IFR STRATUS NEARBY AT KSUS AND KCPS AND MAY IMPACT TERMINAL EARLY
THIS MORNING. OTHERWISE...WIND SHIFT WITH COLD FRONT EXPECTED
AROUND 15Z. VFR CONDITIONS EXPECTED THIS AFTERNOON WITH THE
POTENTIAL OF A SHOWER OR STORM. CHANCES ARE TOO LOW TO INCLUDE IN
FORECAST AT THIS TIME.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 40 30 10 5
QUINCY 83 64 84 62 / 40 30 5 0
COLUMBIA 87 67 85 63 / 40 30 5 0
JEFFERSON CITY 89 68 86 63 / 40 30 5 0
SALEM 86 70 84 63 / 40 30 10 5
FARMINGTON 86 69 84 61 / 40 30 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1020 AM EDT MON AUG 10 2015
.SYNOPSIS...A WARM FRONT TO OUR SOUTHWEST THIS MORNING WILL LIFT
NORTH ACROSS THE AREA TODAY. A COLD FRONT WILL SWEEP THROUGH THE
REGION TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE
AREA ON WEDNESDAY AND PERSIST THROUGH THE REMAINDER OF THE WORK
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1020 AM MONDAY...
CURRENT FORECAST IS IN GOOD SHAPE. MAIN CHANGES WERE TO EXPAND IN
TIME AND AREA THE BAND OF PATCHY SHOWERS CURRENTLY TRACKING THROUGH
THE CWA... DRIVEN BY WEAK MOIST ISENTROPIC UPGLIDE IN THE LOW LEVELS
AND A WEAK MID LEVEL WAVE... AND TO DELAY AFTERNOON CONVECTION IN
THE WEST. HIGH-PW AIR (1.8-2.0") PERSISTS OVER CENTRAL NC WITH
CONSIDERABLE MID AND HIGH DEBRIS CLOUDINESS FROM UPSTREAM MCS ACTION
OVERSPREADING THE AREA FROM THE NW... AND THIS SHOULD SOMEWHAT CURB
THE POTENTIAL FOR INSTABILITY THIS AFTERNOON. EXTRAPOLATION WOULD
FAVOR ANY MCVS GENERATED BY LAST NIGHT`S THE CONVECTIVE COMPLEXES
ACROSS SRN KS/MO/IL INTO WRN KY/TN LIKELY TRACKING WELL TO OUR SW...
AND THIS TREND IS INDICATED BY THE NSSL WRF AND NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES. THESE MODEL PACKAGES ALSO SUGGEST THAT
THE CHANCE FOR DEEP CONVECTION EAST OF HIGHWAY 1 THIS AFTERNOON INTO
TONIGHT IS QUITE LOW... AND THE HRRR ALSO DEPICTS LITTLE TO NO
COVERAGE OVER ALL BUT THE FAR WRN CWA AFTERNOON THROUGH AT LEAST
23Z. AFTER SLOWLY TRENDING THE COVERAGE OF SHOWERS DOWN THIS MORNING
INTO EARLY AFTERNOON AS THEY TREND EASTWARD WITH WANING UPGLIDE...
HAVE REDUCED CONVECTION CHANCES TO SLIGHT OR NIL IN THE EAST THIS
AFTERNOON... AND HAVE CUT BACK COVERAGE IN THE WRN CWA A BIT AS
WELL. GIVEN THE GENERALLY MOSTLY CLOUDY SKIES TODAY... HAVE CUT A
COUPLE OF DEGREES OFF HIGHS... NOW RANGING FROM 84 TO 90. -GIH
EARLIER DISCUSSION AS OF 255 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE EXTENDING INTO EASTERN VA AND NC. MEANWHILE A WARM
FRONT EXTENDING FROM NEAR NASHVILLE TN SOUTHEAST TO NEAR SAVANNAH GA
WAS BEGINNING TO SLOWLY LIFT NORTHWARD...LIKELY LIFTING THROUGH
CENTRAL NC THIS AFTERNOON AND EVENING. FURTHER ALOFT...A RATHER WEAK
DIFFLUENT NORTHWEST FLOW ALOFT WAS EXPECTED TO STRENGTHEN AND
GRADUALLY BACK AND BECOME SOUTHWESTERLY BY LATE TONIGHT AS AN UPPER
TROUGH DROPS INTO THE GREAT LAKES REGION.
REGIONAL RADAR IMAGERY SHOWS SCT SHOWERS SLOWLY DEVELOPING AND
EXPANDING ACROSS THE YADKIN VALLEY AND THE WESTERN PIEDMONT OF
VA/NC/SC. THIS PRECIPITATION APPEARS TO BE ASSOCIATED WITH SOME
ISENTROPIC UPGLIDE NEAR THE 305K SURFACE ENHANCED BY A WEAK SHORT
WAVE ALOFT AND REMNANTS OF AN UPSTREAM MCS. NWP GUIDANCE SUGGESTS
THAT THESE SHOWERS MAY BECOME MORE NUMEROUS AS THEY MOVE INTO THE
WESTERN PIEDMONT TOWARD DAYBREAK. THE PRECIPITATION SHOULD BEGIN TO
DIMINISH LATE THIS MORNING BEFORE REACHING THE COASTAL PLAIN.
MUCH OF THE DAY TODAY SHOULD FEATURE A FAIR AMOUNT OF CLOUDINESS BUT
MAINLY DRY CONDITIONS ACROSS CENTRAL NC. WITH LITTLE FORCING FOR
ASCENT AND WITH ONLY WEAK INSTABILITY PRESENT THIS AFTERNOON AND
FAIRLY MEAGER MID LEVEL LAPSE RATES...CONVECTIVE COVERAGE SHOULD BE
RATHER LIMITED. THE ENVIRONMENT FOR CONVECTION BECOMES A LITTLE BIT
MORE FAVORABLE THIS EVENING AND OVERNIGHT ACROSS THE WESTERN
PIEDMONT AND TRIAD AREA AS LARGER SCALE FORCING APPROACHES AND MID
LEVEL LAPSE RATE ACCORDINGLY INCREASE. STILL...CONVECTION ALLOWING
MODELS HAVE TRENDED NOTICEABLY LESS ACTIVE FOR THIS AFTERNOON AND
TONIGHT WITH NOCTURNAL CONVECTION NOW APPEARING MORE FOCUSED ACROSS
VA/WV. HIGHS TODAY WILL BE COMPLICATED BY THE AMOUNT OF SUNSHINE AND
WITH A TREND TOWARD LESS PRECIPITATION AND PERHAPS THINNER CLOUDS
HAVE ADJUSTED MAXES UP EVER-SO-SLIGHTLY...HIGHS SHOULD RANGE SHOULD
RANGE FROM 84 TO 91. LOWS TONIGHT WILL BE MODERATED BY A GOOD DEAL
OF CLOUD COVER...LOWS SHOULD RANGE BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 AM MONDAY...
A STRENGTHENING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES AND
NORTHEAST DURING THE PERIOD WITH THE MAIN TROUGH AXIS SHIFTING
ACROSS CENTRAL NC TOWARD DAYBREAK WEDNESDAY. THE ASSOCIATED COLD
FRONT WILL MOVE ACROSS THE APPALACHIANS TUESDAY AFTERNOON AND
THROUGH CENTRAL NC TUESDAY NIGHT...REACHING THE COAST TOWARD
WEDNESDAY MORNING.
SCATTERED CONVECTION IS EXPECTED AHEAD OF THE FRONT TUESDAY MORNING
AND EARLY AFTERNOON. AS NOTED IN THE PREVIOUS DISCUSSION...THIS MAY
PLAY A ROLE IN SUBSEQUENT CONVECTION TUESDAY AFTERNOON AND EVENING.
WITH THE UPPER TROUGH CONTAINING MULTIPLE VORTICITY CENTERS...EXPECT
SHOWERS AND THUNDERSTORMS TO MOVE ACROSS CENTRAL NC IN MULTIPLE
CLUSTER OR BANDS THROUGHOUT THE AFTERNOON AS OPPOSED TO ONE WELL
ORGANIZED LINE. THE CLOUDS AND PRECIPITATION WITH THESE CLUSTERS
SHOULD RETARD INSTABILITY A BIT. SPC HAS CENTRAL NC OUTLOOKED WITH A
MARGINAL THREAT OF SEVERE STORMS WHICH SEEMS REASONABLE GIVEN THE
STRONGER DEEP LAYER FLOW AND BULK SHEAR VALUES OF 20-25 KTS
SUGGESTING SOME STORM ORGANIZATION POSSIBLE. CAPE VALUES SHOULD
RANGE FROM WEAK TO LOW END MODERATE WITH MLCAPE VALUES CLIMBING TO
THE 750-1250 J/KG RANGE. THIS ENVIRONMENT WOULD SUPPORT A
MULTICELLULAR/LINE SEGMENT CONVECTIVE MODE WITH A FEW STRONG STORMS
AND POSSIBLY A SEVERE THUNDERSTORMS WITH DAMAGING WINDS THE MOST
LIKELY THREAT. WITH A LINGERING SHORT WAVE TROUGH LIKELY TO MOVE
ACROSS CENTRAL NC LATE TUESDAY EVENING...ANOTHER ROUND OF STORMS IS
POSSIBLE WITH THIS FEATURE AND THE ASSOCIATED COLD FRONT. THE FRONT
SHOULD EXIT THE RAH CWA BETWEEN 06-12Z AND BRING THE PRECIPITATION
TO AN END. HIGHS IN THE 86 TO 91 RANGE WITH LOWS TUESDAY NIGHT IN
THE 65 TO 73 RANGE. -BLAES
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 255 AM MONDAY...
WEDNESDAY THROUGH FRIDAY... UPPER AIR PATTERN WILL BE DOMINATED BY A
STRONG...AMPLIFIED RIDGE ALONG THE SPINE OF THE ROCKIES...AND A L/W
TROUGH ALONG THE EASTERN SEABOARD. THIS TROUGH IS AT ITS MOST
AMPLIFIED/DEEPEST AT MID WEEK THEN WEAKENS/BROADENS BY THE END OF
THE WEEK. THIS SET-UP WILL SPREAD A DRIER STABLE AIR MASS INTO
CENTRAL NC ON WEDNESDAY WHICH SHOULD LINGER THROUGH THE REMAINDER OF
THE WORK WEEK AS AN AREA OF HIGH PRESSURE AT THE SURFACE BUILDS INTO
THEN SETTLES OVERHEAD BY FRIDAY. ASIDE FROM A SLIGHT CHANCE OF A
SHOWER EARLY WEDNESDAY OVER THE SE COUNTIES AS A COLD FRONT EXITS
THE REGION...EXPECT DRY WEATHER WEDNESDAY THROUGH FRIDAY...AND
TEMPERATURES AVERAGING FAIRLY CLOSE TO NORMAL FOR MID AUGUST. ONE
THING THAT WILL BE LACKING WILL BE THE TYPICAL LATE SUMMER HUMIDITY
AS AFTERNOON DEWPOINTS WILL DROP INTO THE 50S-LOWER 60S EACH
AFTERNOON...ESPECIALLY ON THURSDAY AND FRIDAY. THIS WILL LEAD TO
FAIRLY COMFORTABLE CONDITIONS FOR MID-AUGUST.
FOR SATURDAY THROUGH SUNDAY...THE UPPER RIDGE BECOMES ORIENTATED SW-
NE FROM THE DESERT SW INTO THE GREAT LAKES WHILE THE L/W TROUGH
MAINTAINS A PRESENCE ALONG THE EASTERN SEABOARD. THE SFC HIGH
WEAKENS WITH TIME BUT CONTINUES TO INFLUENCE THE SENSIBLE WEATHER
OVER CENTRAL NC AS THE LOW LEVEL FLOW WILL MAINTAIN A FAIRLY MILD
AIR MASS FOR THIS TIME OF YEAR. ENOUGH MOISTURE MAY CREEP BACK INTO
SECTIONS OF OUR COASTAL PLAIN AND SANDHILL COUNTIES BY SUNDAY TO
SPARK AN ISOLATED SHOWER OR STORM IN THE AFTERNOON. THE ATMOSPHERE
WILL UNDERGO SLIGHT MODIFICATION...LEADING TO TEMPS SLIGHTLY ABOVE
NORMAL BY SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD ALTHOUGH A
STRENGTHENING SOUTHWESTERLY FLOW WILL PROVIDE INCREASING MOISTURE
AND CLOUDS ALONG WITH A CHANCE OF CONVECTION...MAINLY ACROSS THE
WESTERN PIEDMONT.
SCATTERED SHOWERS ACROSS THE WESTERN AND NORTHERN PIEDMONT NEAR THE
KGSO/KINT TERMINALS WILL CONTINUE TO MOVE SOUTH AND EAST THIS
MORNING BUT GRADUALLY WEAKEN AS THEY APPROACH THE NORTHEAST PIEDMONT
INCLUDING KRDU TERMINAL. THESE SHOWERS MAY PRODUCE A BRIEF MVFR
CIG/VSBY RESTRICTION. OTHERWISE...VFR CONDITIONS WITH LAYERS OF MID
AND HIGH CLOUDS ARE EXPECTED THIS MORNING ALONG WITH A SOUTH WIND
AROUND 10KTS OR LESS.
INCREASING AND LOWERING VFR CLOUDS ARE EXPECTED THIS AFTERNOON AND
EVENING WITH CEILINGS GENERALLY RANGING BETWEEN 4-10KFT. WINDS WILL
STRENGTHEN FROM THE SOUTH AND SOUTHWEST AFTER A WARM FRONT MOVES
THROUGH THE AREA WITH GUSTS UP TO 16KTS AT TIMES AT THE
KINT/KGSO/KRDU TERMINALS. WHILE AN ISOLATED SHOWER CANT BE RULED OUT
DURING THE LATE MORNING INTO THE MID AFTERNOON HOURS THE COVERAGE
SHOULD BE LIMITED ENOUGH TO EXCLUDE FROM THE TAFS. DURING THE LATE
AFTERNOON...SCT THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS WESTERN
NC AND THEN MOVE EAST IMPACTING THE KINT/KGSO/KRDU TERMINALS BETWEEN
20-02Z WITH MVFR VSBY AND CIG RESTRICTIONS. THESE STORMS WILL PUSH
EAST POTENTIALLY REACHING KFAY/KRWI TOWARD MIDNIGHT. GUIDANCE ALSO
SUGGESTS THAT A LAYER OF IFR/MVFR STRATUS MAY DEVELOP TOWARD
DAYBREAK AT THE KFAY/KRWI TERMINALS.
LOOKING BEYOND 06Z TUE...THUNDERSTORMS WILL LIKELY PUSH EAST MONDAY
NIGHT AND WEAKEN WITH A PERIOD OF ADVERSE AVIATION CONDITIONS
POSSIBLE. ANOTHER PERIOD OF SHOWERS/THUNDERSTORMS WITH ADVERSE
AVIATION CONDITIONS APPEARS TO BE A GOOD BET TUESDAY AND TUESDAY
NIGHT AS A COLD FRONT MOVES THROUGH THE AREA. FAIR WEATHER WITH
MAINLY VFR CONDITIONS ARE EXPECTED FROM WEDNESDAY INTO FRIDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...WSS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
834 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 815 AM CDT MON AUG 10 2015
12Z BISMARCK SKEW-T SHOWS A CONVECTIVE TEMPERATURE OF 77F TODAY
WHICH WILL BE REACHED BETWEEN 16Z-17Z/11AM-NOON CDT. EXPECTING
SOME CUMULUS TO DEVELOP...HOWEVER TIME-HEIGHT CROSS SECTIONS SHOW
LIMITED MOISTURE IN THE 850-700MB LAYER...WITH DRIER AIR ABOVE.
LATEST WATER VAPOR IMAGERY LOOP REVEALS A SHORTWAVE/VORTICITY LOBE
LOCATED IN FAR SOUTHEAST SASKATCHEWAN EXTENDING INTO WESTERN NORTH
DAKOTA. THIS SHORTWAVE IS PICKED UP BY THE GFS AND IS FORECAST TO
REACH THE JAMES RIVER VALLEY 21Z-00Z. 850MB-700MB LAPSE RATES
FORECAST AT 9.5C/KM LATE THIS AFTERNOON IN CENTRAL NORTH DAKOTA.
HI RESOLUTION MODELS HRRR/ARW WEST/NMM WEST INDICATE ISOLATED
SHOWERS BETWEEN BISMARCK AND JAMESTOWN 21Z-00Z. THE PREVIOUS
DISCUSSION MENTIONED THIS POTENTIAL. BUFKIT SOUNDINGS CURRENTLY
MAINTAIN A SHALLOW POCKET OF MOISTURE REMAINING IN PLACE LATE THIS
AFTERNOON WHEN THE MAX OMEGA/VERTICAL MOTION IN THE LOWEST LAYERS
IS REACHED. WITH VERY MINIMAL AREAL COVERAGE AT THIS TIME...WILL
KEEP THINGS DRY AND WATCH THE TRENDS AND ADJUST IF NEEDED LATER
THIS MORNING. FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 542 AM CDT MON AUG 10 2015
MADE A QUICK UPDATE TO ADD PATCHY FOG FROM HETTINGER...THOUGH
WASHBURN...TO RUGBY AND ROLETTE. OBSERVATIONS THIS MORNING HAVE
FAVORED THAT REGION FOR FOG...AND THIS ALSO LINES UP WITH THE
LATEST ITERATIONS OF THE HRRR AND RAP13. A COUPLE ROGUE SHOWERS
DEVELOPED OVERNIGHT IN PARTS OF LOGAN AND MCINTOSH COUNTIES...BUT
THOSE HAVE DISSIPATED. THE REMAINDER OF THE FORECAST IS ON TRACK
AND ONLY ADJUSTED TO CAPTURE THE LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT MON AUG 10 2015
A QUIET START TO THE DAY IS EXPECTED WITH HIGH PRESSURE IN PLACE
AT THE SURFACE ACROSS THE NORTHERN PLAINS. WILL HAVE TO MONITOR
VISIBILITIES OVER THE NEXT FEW HOURS WITH LOW TEMPERATURE /
DEWPOINT SPREADS...OTHERWISE SKIES WILL BE MOSTLY SUNNY EARLY THIS
MORNING.
A POTENTIAL CONCERN FOR TODAY IS THE CHANCE FOR AN ISOLATED SHOWER
OR THUNDERSTORM THIS AFTERNOON. SOME OF THE HI-RES MODEL
SOLUTIONS HAVE HINTED AT THE POSSIBILITY OF AN ISOLATED SHOWER AS
LOW LEVEL LAPSE RATES STEEPEN THIS AFTERNOON. FORECAST SOUNDINGS
SHOW ONLY A SMALL AREA OF INCREASED MOISTURE (RELATIVE HUMIDITY)
THIS AFTERNOON AROUND H85...WITH VERY DRY AIR IN PLACE IN THE LOW
LEVELS. FOR NOW...WILL STAY WITH THE DRY FORECAST AND ONLY SHOW
SOME INCREASE IN CLOUDS AS CUMULUS DEVELOPS THIS AFTERNOON. HIGH
TEMPERATURES TODAY WILL BE IN THE 80S.
TONIGHT WILL SEE CLEARING SKIES AS THE CUMULUS DISSIPATES DURING
THE EVENING. LOWS SHOULD GENERALLY BE IN THE MID 50S TO NEAR 60.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 314 AM CDT MON AUG 10 2015
DETERMINISTIC MODELS AND ENSEMBLE OUTPUT CONTINUE TO INDICATE
STRONG UPPER LEVEL RIDGE BUILDING ACROSS WESTERN NORTH AMERICA AND
SLOWLY MOVING ACROSS THE NORTHERN PLAINS BY LATE WEEK AS DEEP
UPPER LOW MOVES INTO THE PAC NW BY THU/FRI. HIGH TEMPS ACROSS
WESTERN AND CENTRAL ND WILL REACH MID/UPPER 90S BY WEDNESDAY AND
THURSDAY WITH THE HIGHEST TEMPS ACROSS THE WEST. TEMPS WILL REMAIN
ABOVE NORMAL...BUT SLIGHTLY LOWER BY FRI AND SAT AS UPPER LEVEL
RIDGE AXIS SLOWLY PUSHES EAST OF US. MODELS GENERATE SOME
CONVECTIVE PRECIP TUE NIGHT AND WED WITH GFS INDICATING SOME
ELEVATED INSTABILITY AND A LOW LEVEL JET STRENGTHENING TUE NIGHT
AND UP TO 2000 J/KG OF SURFACE BASED CAPE ON WEDNESDAY. PROXIMITY
OF UPPER LEVEL RIDGE AND GENERAL ANTICYCLONIC FLOW WILL LIMIT
CONVECTIVE POTENTIAL...BUT AN ISOLATED SHOWER OR THUNDERSTORM IS
NOT OUT OF THE QUESTION WITH MODELS SHOWING A FEW WEAK SHORTWAVE
TROUGHS RIDING OVER THE RIDGE. BETTER CHANCE FOR PRECIP WILL BEGIN
FRIDAY EVENING AS COLD FRONT MOVES THROUGH THE REGION ON SATURDAY
PER GFS/ECMWF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 542 AM CDT MON AUG 10 2015
EXPECT VFR CONDITIONS TO DOMINATE FOR THE 12Z TAF PERIOD. VERY
PATCHY FOG HAS DEVELOPED ACROSS PARTS OF CENTRAL INTO NORTHEAST
NORTH DAKOTA...BUT DO NOT EXPECT IT TO PERSIST. WILL MONITOR THE
LATEST OBSERVATIONS AND TRY TO KEEP ANY FOG MENTION TO A MINIMUM.
WINDS SHOULD STAY LESS THAN 10KTS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...CK
LONG TERM...JNS
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
542 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 542 AM CDT MON AUG 10 2015
MADE A QUICK UPDATE TO ADD PATCHY FOG FROM HETTINGER...THOUGH
WASHBURN...TO RUGBY AND ROLETTE. OBSERVATIONS THIS MORNING HAVE
FAVORED THAT REGION FOR FOG...AND THIS ALSO LINES UP WITH THE
LATEST ITERATIONS OF THE HRRR AND RAP13. A COUPLE ROGUE SHOWERS
DEVELOPED OVERNIGHT IN PARTS OF LOGAN AND MCINTOSH COUNTIES...BUT
THOSE HAVE DISSIPATED. THE REMAINDER OF THE FORECAST IS ON TRACK
AND ONLY ADJUSTED TO CAPTURE THE LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT MON AUG 10 2015
A QUIET START TO THE DAY IS EXPECTED WITH HIGH PRESSURE IN PLACE
AT THE SURFACE ACROSS THE NORTHERN PLAINS. WILL HAVE TO MONITOR
VISIBILITIES OVER THE NEXT FEW HOURS WITH LOW TEMPERATURE /
DEWPOINT SPREADS...OTHERWISE SKIES WILL BE MOSTLY SUNNY EARLY THIS
MORNING.
A POTENTIAL CONCERN FOR TODAY IS THE CHANCE FOR AN ISOLATED SHOWER
OR THUNDERSTORM THIS AFTERNOON. SOME OF THE HI-RES MODEL
SOLUTIONS HAVE HINTED AT THE POSSIBILITY OF AN ISOLATED SHOWER AS
LOW LEVEL LAPSE RATES STEEPEN THIS AFTERNOON. FORECAST SOUNDINGS
SHOW ONLY A SMALL AREA OF INCREASED MOISTURE (RELATIVE HUMIDITY)
THIS AFTERNOON AROUND H85...WITH VERY DRY AIR IN PLACE IN THE LOW
LEVELS. FOR NOW...WILL STAY WITH THE DRY FORECAST AND ONLY SHOW
SOME INCREASE IN CLOUDS AS CUMULUS DEVELOPS THIS AFTERNOON. HIGH
TEMPERATURES TODAY WILL BE IN THE 80S.
TONIGHT WILL SEE CLEARING SKIES AS THE CUMULUS DISSIPATES DURING
THE EVENING. LOWS SHOULD GENERALLY BE IN THE MID 50S TO NEAR 60.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 314 AM CDT MON AUG 10 2015
DETERMINISTIC MODELS AND ENSEMBLE OUTPUT CONTINUE TO INDICATE
STRONG UPPER LEVEL RIDGE BUILDING ACROSS WESTERN NORTH AMERICA AND
SLOWLY MOVING ACROSS THE NORTHERN PLAINS BY LATE WEEK AS DEEP
UPPER LOW MOVES INTO THE PAC NW BY THU/FRI. HIGH TEMPS ACROSS
WESTERN AND CENTRAL ND WILL REACH MID/UPPER 90S BY WEDNESDAY AND
THURSDAY WITH THE HIGHEST TEMPS ACROSS THE WEST. TEMPS WILL REMAIN
ABOVE NORMAL...BUT SLIGHTLY LOWER BY FRI AND SAT AS UPPER LEVEL
RIDGE AXIS SLOWLY PUSHES EAST OF US. MODELS GENERATE SOME
CONVECTIVE PRECIP TUE NIGHT AND WED WITH GFS INDICATING SOME
ELEVATED INSTABILITY AND A LOW LEVEL JET STRENGTHENING TUE NIGHT
AND UP TO 2000 J/KG OF SURFACE BASED CAPE ON WEDNESDAY. PROXIMITY
OF UPPER LEVEL RIDGE AND GENERAL ANTICYCLONIC FLOW WILL LIMIT
CONVECTIVE POTENTIAL...BUT AN ISOLATED SHOWER OR THUNDERSTORM IS
NOT OUT OF THE QUESTION WITH MODELS SHOWING A FEW WEAK SHORTWAVE
TROUGHS RIDING OVER THE RIDGE. BETTER CHANCE FOR PRECIP WILL BEGIN
FRIDAY EVENING AS COLD FRONT MOVES THROUGH THE REGION ON SATURDAY
PER GFS/ECMWF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 542 AM CDT MON AUG 10 2015
EXPECT VFR CONDITIONS TO DOMINATE FOR THE 12Z TAF PERIOD. VERY
PATCHY FOG HAS DEVELOPED ACROSS PARTS OF CENTRAL INTO NORTHEAST
NORTH DAKOTA...BUT DO NOT EXPECT IT TO PERSIST. WILL MONITOR THE
LATEST OBSERVATIONS AND TRY TO KEEP ANY FOG MENTION TO A MINIMUM.
WINDS SHOULD STAY LESS THAN 10KTS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...CK
LONG TERM...JNS
AVIATION...CK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1108 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NO REAL CHANGES TO THE FORECAST. TWEEKED POPS A TAD TO ACCOUNT FOR
DEVELOPING CONVECTION. OTHERWISE, NO OTHER CHANGES ARE EXPECTED.
PREVIOUS DISCUSSION...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY
WISE/BEST...NOT TO RUN WITH ANY ONE MODEL SOLUTION. WITH
ADJUSTMENTS BEING MADE DURING THE COURSE OF THE DAY AND EVENING
BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL OUTSIDE OF BRIEF MVFR CONDITIONS IN
CONVECTION THIS AFTERNOON.
INCREASED THUNDERSTORM COVERAGE IN SE OHIO AFTER 20Z...THEN MOVE
INTO WV FOR 00Z TO 06Z. COULD NOT RULE OUT A FEW STRONG TO SEVERE
CELLS. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT BKN TO OVC AND
VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
LINGERING SHOWERS 06Z TO 12Z TUESDAY...CEILINGS COULD LOWER TO NEAR
1 THSD FT NEAR FRONT AND VSBY 3 TO 5 MILES...AND LINGER PAST
12Z TUESDAY IN THE WV MOUNTAINS.
HAVE ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY...THEN NEAR A EKN TO HTS LINE BY 12Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
EDT 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H M M M M M H M M M
BKW CONSISTENCY H H H H M M M M M M H H
EKN CONSISTENCY H H H H M M M M M M M H
PKB CONSISTENCY H H H H H M M M M M M M
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 12Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...JS/KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...JS/KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
645 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY WISE/BEST...NOT TO RUN WITH ANY
ONE MODEL SOLUTION. WITH ADJUSTMENTS BEING MADE DURING THE COURSE OF
THE DAY AND EVENING BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
IN THE WAKE OF THE OVERNIGHT MID LEVEL DISTURBANCE AND A FEW LIGHT SHOWERS
OR SPRINKLES...THE MID DECK WAS THINNING AT 10Z...ALLOWING SOME
DENSER VALLEY FOG IN THE WV MOUNTAIN VALLEYS.
THE FOG SHOULD DISSIPATE BY 13Z.
AT 10Z...MAIN CONVECTION COMPLEXES DROPPING SE THROUGH WRN KY AND TN...BUT
A FEW SHOWERS MAY FORM FURTHER E AND AFFECT HTS TRI STATE AND SW VA THIS
MORNING.
WILL HAVE MOSTLY 3 TO 5 THSD FT SCT TO BKN AGL CU FORMING TODAY WITH LAYERS
ABOVE. COULD NOT TIME ANY DEFINITE ROUNDS OF CONVECTION THIS
AFTERNOON SO HAVE VCNTY THUNDERSTORM IN MOST TAF SITES.
HOWEVER...LATER IN THE DAY...TRIED TO INCREASE THUNDERSTORM COVERAGE IN SE
OHIO AFTER 20Z...THEN MOVE INTO WV FOR 00Z TO 06Z. COULD NOT RULE OUT A
FEW STRONG TO SEVERE CELLS. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT
BKN TO OVC AND VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
LINGERING SHOWERS 06Z TO 12Z TUESDAY...CEILINGS COULD LOWER TO NEAR
1 THSD FT NEAR FRONT AND VSBY 3 TO 5 MILES...AND LINGER PAST
12Z TUESDAY IN THE WV MOUNTAINS.
HAVE ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY...THEN NEAR A EKN TO HTS LINE BY 12Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/10/15
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY M H H H H H H H H H H H
HTS CONSISTENCY M H H H H H H H H M M M
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY L L M M H H H H H H M M
PKB CONSISTENCY M H H H H H H H H H H M
CKB CONSISTENCY M M H H H H H H H H H H
AFTER 12Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
604 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY WISE/BEST...NOT TO RUN WITH ANY
ONE MODEL SOLUTION. WITH ADJUSTMENTS BEING MADE DURING THE COURSE OF
THE DAY AND EVENING BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
THIS EVENING INTO WV. HOWEVER...AS OF THIS EARLY HOUR...COULD NOT
HIGHLIGHT A SPECIFIC THREAT AREA. WOULD NOT BE SURPRISED IF SPC
UPDATES ON DAY 1...INCLUDED SOME SLIGHT RISK AREAS...AS THIS WHOLE
SYSTEM EVOLVES/DEVELOPS.
OVERALL NOT TOO EXCITED WITH THE THIN CAPE AND RELATIVELY WEAK FLOW
AS DISCUSSED. MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
IN THE WAKE OF THE OVERNIGHT MID LEVEL DISTURBANCE AND A FEW LIGHT SHOWERS
OR SPRINKLES...THE MID DECK WAS THINNING AT 10Z...ALLOWING SOME
DENSER VALLEY FOG IN THE WV MOUNTAIN VALLEYS.
THE FOG SHOULD DISSIPATE BY 13Z.
AT 10Z...MAIN CONVECTION COMPLEXES DROPPING SE THROUGH WRN KY AND TN...BUT
A FEW SHOWERS MAY FORM FURTHER E AND AFFECT HTS TRI STATE AND SW VA THIS
MORNING.
WILL HAVE MOSTLY 3 TO 5 THSD FT SCT TO BKN AGL CU FORMING TODAY WITH LAYERS
ABOVE. COULD NOT TIME ANY DEFINITE ROUNDS OF CONVECTION THIS
AFTERNOON SO HAVE VCNTY THUNDERSTORM IN MOST TAF SITES.
HOWEVER...LATER IN THE DAY...TRIED TO INCREASE THUNDERSTORM COVERAGE IN SE
OHIO AFTER 20Z...THEN MOVE INTO WV FOR 00Z TO 06Z. COULD NOT RULE OUT A
FEW STRONG TO SEVERE CELLS. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT
BKN TO OVC AND VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
LINGERING SHOWERS 06Z TO 12Z TUESDAY...CEILINGS COULD LOWER TO NEAR
1 THSD FT NEAR FRONT AND VSBY 3 TO 5 MILES...AND LINGER PAST
12Z TUESDAY IN THE WV MOUNTAINS.
HAVE ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY...THEN NEAR A EKN TO HTS LINE BY 12Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/10/15
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY M H H H H H H H H H H H
HTS CONSISTENCY M H H H H H H H H M M M
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY L L M M H H H H H H M M
PKB CONSISTENCY M H H H H H H H H H H M
CKB CONSISTENCY M M H H H H H H H H H H
AFTER 12Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1057 AM CDT MON AUG 10 2015
.UPDATE...
LOWERED TEMPS A FEW DEGREES ACROSS THE NORTH AND ADJUSTED POPS
SLIGHTLY.
&&
.DISCUSSION...
SCATTERED SHOWERS AND STORMS CONTINUE ALONG A WEAK MID LEVEL
CONVERGENCE ZONE ACROSS NORTH CENTRAL OK. THIS ZONE WILL SLOWLY
SHIFT SOUTHWARD DURING THE DAY BUT WITH LITTLE TO NO OTHER
SUPPORT PRESENT (LLJ DISSIPATING) EXPECT COVERAGE WILL DIMINISH
THROUGH THIS AFTERNOON. THE HRRR APPEARS TO HAVE A PRETTY GOOD
HANDLE ON THE FORECAST SO WEIGHTED POPS HEAVILY TOWARDS IT.
TEMPS WHERE ALSO LOWERED 2-4 DEGREES ACROSS NORTHERN OK...AND
PORTIONS OF CENTRAL OK...WHERE CLOUD COVER WILL LIKELY LINGER
THROUGH THE DAY. ALL UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT MON AUG 10 2015/
DISCUSSION...
MAIN CONCERNS WILL BE PRECIP ACROSS THE NORTH AND HEAT FARTHER
SOUTH TODAY AND THEN COOL-OFF AND PRECIP CHANCES THIS WEEK.
CONT TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS NORTHWEST
INTO NORTHERN OKLAHOMA THIS MORNING NEAR A SLOW MOVING COLD FRONT.
THIS FRONT IS A BIT SLOWER THAN MODELS HAVE BEEN SHOWING. THIS
WILL ALLOW FOR TEMPS TO BE A BIT WARMER ACROSS PARTS OF THE AREA
TODAY. BECAUSE OF THIS WE WILL END UP WITH SOME HIGHER HEAT
INDICES AND WILL NECESSITATE THE NEED TO BRING THE HEAT ADVISORY
FARTHER NORTH INTO CENTRAL OKLAHOMA.
FRONT STILL EXPECTED TO PUSH SOUTH TOWARD THE RED RIVER BY TUESDAY
MORNING. SLIGHTLY COOLER TEMPS EXPECTED BEHIND THE FRONT. AS THIS
IS OCCURRING... UPPER RIDGE WILL BE BUILDING BACK NORTH ACROSS THE
SOUTHERN/CENTRAL ROCKIES. MODELS CONT TO INDICATE AT LEAST A
CHANCE FOR SOME ADDITIONAL PRECIP CHANCES INTO THE MIDDLE OF THE
WEEK AS WE COME UNDER THE INFLUENCE OF WEAK NORTHWEST FLOW.
HOWEVER TODAY`S MODEL RUNS HAVE SHIFTED THE MOISTURE PLUME FARTHER
WEST AND KEEP MUCH IN THE WAY OF PRECIP CONFINED TO FAR WESTERN
OKLAHOMA AND THE EASTERN TEXAS PANHANDLE AS WE GET INTO WED/THU
TIMEFRAME.
BEYOND THIS IT APPEARS THAT MOISTURE PLUME WILL DISSIPATE AND
UPPER FLOW BECOMES MORE NORTHERLY AS UPPER RIDGE CONT BUILD NORTH
AND NORTHEAST INTO THE CENTRAL AND NORTHERN PLAINS. ALTHOUGH
DRY... THIS PATTERN SHOULD KEEP THE HOTTEST TEMPS TO OUR WEST AND
NORTH BY LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 96 74 90 70 / 30 20 10 10
HOBART OK 97 74 93 70 / 30 20 20 20
WICHITA FALLS TX 104 76 97 73 / 0 10 20 10
GAGE OK 91 70 87 68 / 50 30 30 20
PONCA CITY OK 92 73 89 68 / 60 10 0 10
DURANT OK 104 77 97 73 / 0 10 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR OKZ025>032-039>043-
045>048-050>052.
TX...NONE.
&&
$$
03/14
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
601 AM CDT MON AUG 10 2015
.DISCUSSION... /ISSUED 439 AM CDT MON AUG 10 2015/
A COMPLEX WEATHER DAY ACROSS THE MIDSOUTH. THE UPPER LEVEL RIDGE
THAT BROUGHT TRIPLE DIGIT HEAT CLOSE TO THE MIDSOUTH YESTERDAY HAD
RETROGRADED OVER THE PAST 12 HOURS...RETURNING NORTHWEST FLOW
ALOFT TO THE MIDSOUTH.
SEVERAL THUNDERSTORM COMPLEXES HAD FORMED OVER SOUTHERN MO EARLY
THIS MORNING...MOVING SOUTHEAST ALONG THE UPPER RIDGE PERIPHERY.
ASSUMING THE COLD POOL CAN REMAIN ESTABLISHED THROUGH SUNRISE...
850-500MB THICKNESS FIELDS SUGGEST THESE STORMS WILL MOVE
SOUTH/SOUTHEAST THROUGH NORTHEAST AR...WEST TN AND NORTHEAST MS.
THE HRRR MODEL HAS BEEN CONSISTENT IN DEPICTING SUCH A SCENARIO.
THE AIRMASS FEEDING THESE STORMS WAS RICH WITH MOISTURE...WITH
PRECIPITABLE WATER VALUES AROUND 2.25 INCHES. THE LOW LEVEL JET
HAS BEEN A RELATIVELY WEAK 20KTS...BUT ADEQUATE TO MAINTAIN
STORMS EARLY THIS MORNING.
THUNDERSTORM EVOLUTION THROUGH MIDDAY WILL HAVE SIGNIFICANT
IMPACTS ON AFTERNOON HEAT INDICES. HAVE TRIMMED BACK HEAT
HEADLINES TO REFLECT THE IMPACTS OF THUNDERSTORM OUTFLOW AND
INITIAL CLOUD COVER. HEAT INDEX FORECAST CONFIDENCE IS MARGINAL...
BUT PERHAPS BEST OVER THE MS RIVER DELTA...FROM CLARKSDALE TO
CHARLESTON MS. THIS AREA WILL LEAST LIKELY BE IMPACTED BY
THUNDERSTORM OUTFLOW AND CLOUD COVER...AND NEAREST TO THE
AFTERNOON LOW LEVEL THERMAL RIDGE OVER SOUTHERN AR AND CENTRAL MS.
A WEAK COLD FRONTAL PASSAGE APPEARS ON TRACK FOR LATE THIS EVENING
AND EARLY OVERNIGHT. COOLER AND DRIER AIR WILL LAG 12 TO 18 HOURS
BEHIND THE INITIAL WIND SHIFT...BUT LIKELY SUFFICIENT TO KEEP
TUESDAY AFTERNOON HEAT INDICES BELOW ADVISORY CRITERIA.
WEDNESDAY AND THURSDAY SHOULD SEE COOLER AND DRIER CONDITIONS...WITH
NORTHERLY WINDS. DAYTIME TEMPS WILL GRADUALLY MODERATE TO NEAR
NORMAL VALUES FROM FRIDAY THROUGH NEXT MONDAY...AS THE UPPER RIDGE
BUILDS INTO THE MIDDLE MS RIVER VALLEY. RAIN CHANCES FROM MIDWEEK
THROUGH EARLY NEXT WEEK APPEAR MINIMAL.
PWB
&&
.AVIATION...
12Z TAF SET
LATEST HRRR SHOWS LINE OF CONVECTION THAT CURRENTLY STRETCHES FROM
NEAR KMKL BACK TO THE NW ACROSS SW MO WILL CONTINUE TO PUSH
SOUTHEAST THROUGH THE MIDSOUTH. CONVECTION SHOULD BE SOUTH OF KTUP
BY 20Z. THEREAFTER...LOW CONFIDENCE ON TAFS IF ANY REDEVELOPMENT
WILL OCCUR OR NOT. PUT IN VCTS WORDING AT KJBR AROUND 23Z FOR A
COUPLE OF HOURS BUT HAVE MY DOUBTS IF ATMOSPHERE WILL RECOVER AS
THICK CIRRUS DECK MAY BE OVER CWA FOR MOST OF DAY LIMITING DAYTIME
HEATING. IF CLOUDS CLEAR OVERNIGHT COULD SEE SOME DENSE FOG AT
SOME OF THE TAF SITES BUT FOR NOW HAVE LEFT MENTION OUT. WINDS
WILL TURN AROUND TO THE N GUSTING TO 25-30 KTS INITIALLY BEHIND
GUST FRONT MOVING SOUTHWARD. EXPECT WINDS SHOULD TURN BACK TO SSW
BEFORE SWITCHING BACK TO THE NORTH. WIND DIRECTION AND SPEED WILL
BE VARIABLE TODAY DUE TO THE CONVECTION.
KRM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR PHILLIPS.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR CRITTENDEN-CROSS-LEE AR-POINSETT-ST. FRANCIS.
MO...NONE.
MS...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR CALHOUN-COAHOMA-QUITMAN-TALLAHATCHIE-YALOBUSHA.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR BENTON MS-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TUNICA-
UNION.
TN...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR FAYETTE-SHELBY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
659 AM EDT MON AUG 10 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTHEAST INTO THE REGION TODAY BEFORE
SLIDING TO THE NORTH LATER TONIGHT. A STRONG COLD FRONT WILL PUSH
EAST INTO THE MOUNTAINS BY EARLY TUESDAY AND ACROSS THE REMAINDER
OF THE REGION BY TUESDAY EVENING. HIGH PRESSURE BUILDS INTO THE
AREA BEHIND THE FRONT BY WEDNESDAY...BRINGING SOMEWHAT COOLER AND
DRIER AIR FOR MIDWEEK INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 AM EDT MONDAY...
CLUSTERS OF VERY SLOW MOVING SHOWERS CONTINUE TO DEVELOP EARLY THIS
MORNING ESPCLY OVER THE EAST IN ADVANCE OF A RATHER STRONG MID LEVEL
WAVE DIPPING IN FROM THE NW JUST NORTH OF THE FRONT TO THE SW. THIS
UNDERDONE BY MOST SHORT TERM MODELS INCLUDING THE HRRR SO BUMPING UP
POPS TO AT LEAST CHANCE IN PARTS OF THE EAST AND SLIGHTS OVER THE WEST
WHERE SHRA MORE SPOTTY NATURE CLOSER TO THE ACTUAL IMPULSE ALOFT.
ONCE THIS FEATURE PASSES...LOTS OF UNCERTAINTY IN REGARDS TO THE
CONVECTIVE ENVIRONMENT FROM LATE MORNING INTO THE AFTERNOON WITH A WARM
FRONT HEADING INTO THE MOUNTAINS WHILE CLOUD COVER MAY STAY RATHER
EXTENSIVE. GUIDANCE SOLUTIONS RANGE FROM THE BEST LIFT STAYING WEST OF
THE MOUNTAINS UNTIL THIS EVENING SUPPORTING ONLY SCATTERED SHRA/TSRA
BLUE RIDGE LATER...TO MORE OUTFLOW DRIVEN SUPPORT FROM THE MCS TO THE
WEST WITH THIS RESIDUAL WAVE INTERACTING WITH AT LEAST SOME HEATING
TO PRODUCE MORE MULTICELLULAR BANDS/CLUSTERS SIMILAR TO THE GFS/EC
AND NCAR ENSEMBLE. THIS ALONG THE LINGERING HIGHER 85H THETA-E RIDGE
WEST AND WHERE MODELS SUGGEST AT LEAST SOME DECENT CAPE MAY EXIST BUT
LATER. THUS TRENDED MORE ALONG THOSE LINES AND BUMPED GOING POPS TO A
PERIOD OF CATEGORICAL FAR WEST LATE AND LEFT LIKELYS IN ALL EXCEPT THE
SE WHERE MAY BE LATE OR THIS EVENING BEFORE WHATS LEFT OF WESTERN
COVERAGE MOVES EAST GIVEN WEAK STEERING. THIS COULD ALSO LEAD TO
MORE OF A HEAVY RAINFALL THREAT VS SEVERE GIVEN RATHER MEAGER FLOW
ALOFT AND LACK OF GOOD LAPSES UNLESS HEATING IS BETTER. NUDGED
HIGHS DOWN A FEW DEGREES TO ACCOUNT FOR EARLY CLOUDS/SHRA AND
POTENTIAL FOR QUICK DEVELOPMENT THIS AFTERNOON WITH ANY INSOLATION
PER PWATS OF NEARLY 2 INCHES.
GUIDANCE PUSHES A LOBE OF CONVECTION EAST/NE THIS EVENING AS THE WARM
FRONT LIFTS NORTH AND THE COLD FRONT APPROACHES FROM THE WEST LATE.
THINK BEST COVERAGE THROUGH MIDNIGHT OR SO WITH A RESIDUAL WAVE
OVERHEAD BEFORE POSSIBLY SEEING A BREAK IN ALL EXCEPT THE NORTH LATE AS
THE REGION SLIPS IN BETWEEN THE EXITING WARM FRONT AND UPSTREAM COLD
FRONT. THE COLD FRONT MAY ALSO END UP BRINGING ANOTHER BAND OF
SHRA INTO THE NW SLOPES TOWARD DAYBREAK...SO BLENDING POPS FROM
LIKELYS MOST SPOTS TO INIT...TO MAINLY CHANCE IN ALL EXCEPT THE
EAST/SE OVERNIGHT...AND OVER THE NW LATE. AGAIN MORE HEAVY RAIN
POTENTIAL BUT EXPECT SHRA/TSRA TO MOVE A BIT MORE LATE AS WESTERLY
FLOW DEEPENS SOME AHEAD OF THE COLD FRONT. STILL QUITE WARM/MUGGY
WITH LOWS UPPER 60S/LOW 70S EXCEPT MID 60S VALLEYS AND IN SPOTS
THAT RECEIVE HEAVIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
MODELS HAVE OUR NEXT COLD FRONT MOVING ACROSS THE MOUNTAINS TUESDAY
MORNING...STALLING NEAR THE BLUE RIDGE BY THE AFTERNOON. THE FRONT
WILL EVENTUALLY CLEAR THE PIEDMONT TUESDAY EVENING...WAITING ON A
SURFACE WAVE THAT WILL DEVELOP OVER THE CAROLINAS THEN MOVE OFF THE
MID ATLANTIC COAST. WE CAN NOT RULE OUT SCATTERED SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS TUESDAY AFTERNOON...BUT THE
MAJORITY OF THE STRONGER CONVECTION WILL BE ALONG AND EAST OF HWY
29. THE COVERAGE OF STRONG STORMS FOR THE FORECAST AREA WILL DEPEND
ON THE LOCATION OF THE COLD FRONT AND THE TRACK OF THIS SURFACE
WAVE. MOST MODELS ARE KEEPING THE STRONGER CONVECTION WITH THE
SURFACE LOW OVER CENTRAL NORTH CAROLINA AND THE COASTAL PIEDMONT OF
VIRGINIA. FOR NOW...WILL KEEP CHANCE POPS ACROSS THE FORECAST AREA.
POPS WILL INCREASE IF THE FRONT REMAINS FARTHER TO THE WEST OR
LOWER/DECREASING THROUGH THE AFTERNOON IF THE FRONT PUSHES EAST OF
THE BLUE RIDGE. THE FRONT WILL BE ALONG THE CAROLINA COAST ON
WEDNESDAY. THE DEW POINT FRONT WILL CROSS OVER THE REGION BY
WEDNESDAY EVENING. WITH THE UPPER LEVEL TROUGH OVERHEAD AND
LINGERING LOW LEVEL MOISTURE WEDNESDAY...A GOOD AMOUNT OF FAIR
WEATHER CUMULUS CLOUDS WILL BE PRESENT...BUT NOT EXPECTING ANY TO
PRODUCE MEASURE RAINFALL.
TEMPERATURES ARE EXPECTED TO WARM TO NEAR NORMAL LEVELS TUESDAY.
BEHIND THE FRONT...COOLER THAN NORMAL CONDITIONS ARE EXPECTED...70S
WEST TO LOWER TO MID 80S EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...
MODELS ARE ADVERTISING A RETREAT OF THE UPPER TROF OVER THE
NORTHEAST THIS TIME FRAME. THE LARGE UPPER RIDGE OVER THE CENTRAL
UNITED STATES SLIGHTLY RETROGRADES AND BUILDS NORTHEAST INTO THE
OHIO VALLEY AS A LOW CUTS OFF SOMEWHERE AROUND THE NORTHERN GULF.
AT THE SURFACE BY THURSDAY...HIGH PRESSURE WILL EXTEND FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC REGION. THIS HIGH REMAINS
OVER THE FORECAST AREA THROUGH FRIDAY. MODELS WERE BEGINNING TO
SUGGEST A WEAK LOW OR SOME LEE TROUGHING MAY DEVELOP ON THE EASTERN
SIDE OF THE APPALACHIANS ON SATURDAY. STILL NOT ENOUGH LIFT OR
MOISTURE FOR ANY SUBSTANTIAL PROBABILITY OF PRECIPITATION.
WILL BE STARTING THURSDAY MORNING WITH BELOW NORMAL MINIMUM
TEMPERATURES THEN AIR MASS GRADUALLY MODERATES THROUGH SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 645 AM EDT MONDAY...
CLUSTERS OF SHOWERS REMAIN PERSISTENT ESPCLY ACROSS THE EAST THIS
MORNING WHERE ISOLATED COVERAGE CONTINUES TO AFFECT KLYH/KDAN.
ALSO SEEING SPOTTY LIGHT SHOWERS OVER THE WEST SO WILL START OFF
WITH AT LEAST A VCSH AT MOST LOCATIONS FROM THE BLUE RIDGE EAST
EARLY ON. OTRW EXPECTING A MIX OF AC AND STRATO-CU CIGS THIS
MORNING WITH MOST OF THE VFR VARIETY EXCEPT IN THE VICINITY OF
EASTERN SHOWERS WHERE MVFR REMAINS POSSIBLE. ALSO SOME PATCHY FOG
WILL MAKE FOR LOCALIZED MVFR/IFR THROUGH MID MORNING IN THE
VALLEYS SUCH AS KLWB. ONCE THE CURRENT MID LEVEL WAVE
PASSES...EXPECTING A LULL IN SHOWERS WITH SOME IMPROVEMENT IN CIGS
BEFORE THE NEXT ROUND OF DEEPER MOISTURE ARRIVES THIS AFTERNOON.
EXTENT OF MORE ORGANIZED CONVECTION REMAINS IN QUESTION THIS
AFTERNOON WITH SOLUTIONS FOCUSING MAINLY OVER THE WEST FOR MORE
WIDESPREAD COVERAGE. THIS SHOULD ALLOW ADDED SHOWERS AND A FEW
THUNDERSTORMS TO DEVELOP OVER THE WEST TOWARD EARLY AFTERNOON AND
OUT EAST BY 20Z/4PM. THUS KEPT VCTS IN WITH MODERATE SHRA AT ALL
SITES AFTER 18Z-20Z...WITH MVFR CIGS AT ALL EXCEPT VFR AT KDAN
WHERE WILL HOLD OFF ON PRECIP. SHOWERS LIKELY TO LINGER OR
REDEVELOP OVER THE WEST AFTER THE INITIAL CONVECTION SO LEAVING IN
A MVFR MENTION INTO THE EVENING FOR ALL SITES EXCEPT OVER THE
SOUTHEAST. SHOWERS AND ADDED TSRA COULD ALSO PERSIST OVER THE
SOUTH AND WEST INTO LATER TONIGHT GIVEN OUTFLOW AND APPROACH OF
THE COLD FRONT FROM THE WEST LATE. OTRW CUTTING BACK ON ADDED SHRA
BY MIDNIGHT AT MOST LOCATIONS FOR NOW TO SEE HOW TRENDS UNFOLD
WITH RUNS LATER TODAY.
EXTENDED AVIATION DISCUSSION...
TUESDAY...SHOWERS AND STORMS INCREASE AGAIN ACROSS THE REGION
THANKS TO BOTH A FRONTAL BOUNDARY ENTERING THE REGION AND A
SHORTWAVE TROUGH PROGRESSING EASTWARD THROUGH THE OHIO VALLEY.
MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT SUB-VFR CONDITIONS WHERE
CONVECTION BECOMES MORE ORGANIZED. STRONGER STORMS WILL BE
POSSIBLE LATER TUESDAY...MAINLY ALONG AND EAST OF THE KLYH-KDAN
CORRIDOR.
BY WEDNESDAY INTO FRIDAY...ANOTHER AREA OF HIGH PRESSURE BUILDS
INTO THE REGION MAKING FOR OVERALL VFR CONDITIONS. PATCHY LATE
NIGHT AND EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG WILL AGAIN
BE POSSIBLE...THOUGH AIRMASS WILL LIKELY BE DRIER.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/JM/WP
Area Forecast Discussion
National Weather Service Spokane WA
458 AM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Northeast Blue Mountains
and Camas Prairie areas and propagating as far north as the Northeast
Mountains and Northern Panhandle. A few record high temperatures
may be set Wednesday. A cold front thursday will bring another
active thunderstorm threat along with cooler temperatures by next
weekend.
&&
.DISCUSSION...
...STRONG WINDS POSSIBLE WITH THUNDERSTORMS TODAY...
Today and Tonight: There are a couple of vorticity maximums to
watch out for today. Both are swinging around the base of a deep
upper level low pressure system off of the coast of WA. The first,
and more likely to have the bigger impact, is a shortwave
disturbance currently pushing into northern California early this
morning. This disturbance is progged to quickly push northeast and
begin to push up into the region between noon and 200 PM PDT.
Before we do see the effects of this disturbance, we will see some
lingering light shower activity mainly across the northern half of
the forecast area through this morning.
Satellite imagery indicates a lot of clearing occurring behind
these showers. This will set up a situation where there should be
plenty of sunshine for the atmosphere to destabilize by the
afternoon before the disturbance over California makes it this far
north. Moisture will increase across the region with dew points
expected to remain right around 50 degrees. This will set up the
ingredients for a decent amount of surface based CAPE to work
with. Models are generally showing somewhere in the neighborhood
of 500-1500 J/KG of surface based CAPE across the eastern half of
the forecast area; this generally includes areas east of a line
extending from Ritzville to Republic. Thunderstorms are expected
to initiate over northeast OR and in the southern Panhandle in the
early afternoon and the push northward into southeastern WA and
into the central Panhandle through the afternoon hours. Main
threats with the thunderstorms will be for strong outflow winds.
The WRF-NMM, WRF-ARW and HRRR models all show a signal of a gust
front emanating northward from the convection. These models have
also been consistent with this idea over the past few runs. I
increase winds across the Palouse, into the basin, the Spokane-
Coeur d`Alene corridor and into the northern mtns and ID
Panhandle. These winds may also result in blowing dust with
reduced visibility possible across portions of I-90 and highway 2.
Forecast confidence in the strong outflow winds and blowing dust
is only moderate and there is some bust potential as all the
ingredients need to come together. With that said, there is enough
evidence that concerns are increasing.
Thunderstorms are also expected to include frequent cloud to
ground lightning strikes. There will be some rain with the heavier
thunderstorm cores, but, away from these course, there will also
be a lot of evaporation that takes place. This should result in a
higher potential for new fire starts from lightning strikes. The
Fire Weather Watch will remain as is for now and will be
reassessed later in the morning.
A second disturbance will push up more across central OR in the
wake of the first. This piece of energy will spark off more
thunderstorms that will push northward through the late afternoon
hours. These thunderstorms will push into southern WA by the
evening, but much of the energy will begin to curl off to the
west. This should reduce the amount of forcing that enters the
region with this wave and is expected to result in thunderstorms
diminishing in intensity by this time. /SVH
Tues through Sunday: The Thurs/Fri ejection of the upper trough
still looks like the main focus as far as any widespread thunder
threat and post- frontal windy wx. The vast majority of model
guidance remain similar with digging the upper low S down the Pac
Nw coast. The primary challenge will be dealing with the ejection
of this low NE into Ern Wa and N Idaho Thurs & Fri. The ECMWF is
now only slightly faster to eject this wave NE, and both the GFS
and ECMWF continue with the trend of taking the low nearly
straight north across Wrn Wa and the Cascades. This would mean the
highest threat of thunder would be along and near the Cascades,
definitely NOT where we would prefer given the current wildfires
that may be enhanced by gusty outflow, not to mention new fire
starts. And if this Cascades pcpn is slow to exit, another issue
COULD be debris flows on current and recent burns. Though this is
the most important part of the fcst, it may not be the most
challenging part. As the wave digs S down the coast, Ern Wa and N
Idaho will be in a prolonged southerly fetch of increasing
moisture within a high- amplitude thermal ridge. This will not
only help to destabilize the sfc, but will also complicate matters
since there are at least three nocturnal subtle waves that move N
into Ern Wa through Wed. All of these accompany weak to moderate
convective/potential instability not rooted at the surface that
could produce a few overnight lightning strikes. Overnight low
temps will be very mild. And within the aforementioned thermal
ridge, Spokane may not be the only place that tops record high
temps Wed.bz
&&
.AVIATION...
12Z TAFS: A potent shortwave trough of lower pressure will push
across the region after 20Z. The atmosphere become increasingly
unstable at this time with scattered thunderstorms across much of
extreme eastern WA and into the ID panhandle. The focus of this
thunderstorm activity is expected to remain east of a line from
KMWH to KOMK. Timing of storms at KLWS and KPUW is expected
between 20-00Z and between 23-04Z at KGEG, KSFF and KCOE. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening is
moderate. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 91 64 97 66 100 69 / 20 40 10 20 10 10
Coeur d`Alene 92 59 97 63 99 65 / 30 40 10 20 10 10
Pullman 90 55 96 60 98 63 / 40 30 10 20 20 10
Lewiston 96 65 102 69 106 71 / 40 20 20 20 20 10
Colville 94 60 99 59 104 59 / 20 20 10 20 20 20
Sandpoint 90 54 95 59 98 57 / 20 30 10 20 20 20
Kellogg 92 56 96 60 98 63 / 30 50 10 20 10 20
Moses Lake 94 63 100 64 103 66 / 10 20 10 20 10 10
Wenatchee 94 72 99 70 102 75 / 10 30 10 20 20 10
Omak 96 66 101 66 102 67 / 20 30 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for Northern and Central Idaho Panhandle (Zone 101).
WA...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for East Washington Palouse and Spokane Area (Zone
674).
FIRE Weather Watch from this afternoon through late tonight for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
300 AM PDT MON AUG 10 2015
.SYNOPSIS...A LOW PRESSURE SYSTEM CENTERED OFF THE WASHINGTON COAST
ALONG 130W EARLY THIS MORNING WILL CONTINUE MOVING SOUTHWARD OFF THE
COAST...REACHING WEST OF THE NORTHERN CALIFORNIA COAST TUESDAY...
THEN LIFTING OUT TO THE NORTHEAST AND THROUGH THE PACIFIC NORTHWEST
THURSDAY AND FRIDAY. LOOK FOR OCCASIONAL SHOWERS OR THUNDERSTORMS IN
THE AFTERNOONS AND EVENINGS DURING THE WEEK THAT MAY DRIFT OUT INTO
THE VALLEYS AND THE COAST RANGE AT TIMES IN THE EVENINGS AND
OVERNIGHT PERIODS. THE BEST CHANCE OF MORE WIDESPREAD SHOWERS OR
THUNDERSTORMS IS LATER THURSDAY INTO FRIDAY AS THE LOW MOVES ONSHORE
AND INLAND. WARMER AND DRY WEATHER IS EXPECTED TO RETURN NEXT
WEEKEND.
&&
.SHORT TERM...AS ADVERTISED...A CLOSED UPPER LOW WAS LOCATED OFF THE
WASHINGTON COAST EARLY THIS MORNING CENTERED ALONG 130W. THE LOW WILL
CONTINUE TO MOVE SOUTHWARD AND WILL BE CENTERED OFF THE OREGON COAST
THIS AFTERNOON. THIS WILL CAUSE THE FLOW ALOFT TO BACK TO MORE
SOUTHERLY TODAY...WARMING THE AIR MASS SOME. A BAROCLINIC OR FRONTAL
ZONE HAS DEVELOPED OVER THE COASTAL WATERS BUT WILL HAVE TROUBLE
MAKING MUCH INLAND PROGRESSION TODAY DUE TO THE SOUTHERLY FLOW ALOFT.
THE COAST MIGHT GET BRUSHED WITH A FEW SHOWERS THOUGH. TEMPS INLAND
TODAY WILL BE IN AT LEAST THE MID 80S AND POSSIBLY THE UPPER 80S. THE
MODELS ALSO INDICATE THAT CONVECTION WILL DEVELOP OVER THE CASCADES
AND FOOTHILLS THIS AFTERNOON AS A SHORT WAVE LIFTS NORTH ALONG THE
EASTERN PERIPHERY OF THE OFFSHORE LOW...AND POSSIBLY EVEN OVER THE
VALLEY OR INTO THE COAST RANGE LATER TODAY OR TONIGHT. THERE IS SOME
UPPER JET SUPPORT FOR THIS CONVECTION TODAY AND THIS EVENING...AND
SOME OF THE THUNDERSTORMS THAT DO DEVELOP COULD BE STRONGER THAN WHAT
WE NORMALLY SEE. AS THE LOW CONTINUES TO MOVE SOUTH TONIGHT INTO
TUESDAY...THE UPPER FLOW TURNS SOUTHEASTERLY AND WILL CAUSE ANY
RESIDUAL ACTIVITY TO DRIFT OUT OVER THE VALLEYS AND TOWARD THE COAST
RANGE TONIGHT.
THINGS SHOULD SETTLE DOWN BY TUESDAY MORNING AS THE LAST OF THE
MOISTURE DRIFTS OUT OVER THE COASTAL WATERS AND WEAKENS. THE LOW WILL
CONTINUE TO MOVE SOUTH AND BE CENTERED SOUTH OF 40N AND WEST OF 130W
OFF THE NORTHERN CALIFORNIA COAST BY LATER TUESDAY. THERE IS AGAIN A
CHANCE OF THUNDER OVER THE CASCADES TUESDAY AFTERNOON THAT COULD
DRIFT OUT OVER THE VALLEYS TUESDAY NIGHT UNDER PREVAILING SOUTHEAST
FLOW ALOFT. THE AIR MASS WILL CONTINUE TO BE QUITE WARM TO THE EAST
AND NORTHEAST OF THE LOW ON TUESDAY...AND INLAND TEMPS MAY APPROACH
90 ON TUESDAY.
THE LOW MEANDERS OFF THE NORTHERN CALIFORNIA COAST WEDNESDAY. THE
MODELS SUGGEST THAT AFTER THE RESIDUAL CONVECTIVE ACTIVITY FROM
TUESDAY NIGHT DRIFTS NORTHWEST AND AWAY FROM OUR AREA WEDNESDAY
MORNING...THAT ACTIVITY WILL BE LESS WEDNESDAY AFTERNOON AND EVENING.
HAVE KEPT A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDER OVER THE
CASCADES.
THE MODELS SHOW OUR CURRENT SOUTH WINDS ALONG THE COAST THIS MORNING
TURNING NORTHERLY IN THE WAKE OF THE LOW LATER TODAY AND TONIGHT. THE
WINDS THEN TURN BACK TO SOUTHERLY AGAIN WEDNESDAY AS A SOUTHERLY WIND
REVERSAL AND STRATUS SURGE MOVES UP THE COAST IN RESPONSE TO SHORT
WAVE MOVING NORTH ALONG THE COAST. THIS SHOULD BUILD THE MARINE LAYER
ALONG THE COAST AND IS THE FIRST STEP IN STARTING TO INCREASE THE
ONSHORE FLOW. WE MAY SEE SOME PATCHY DRIZZLE IN THIS STRENGTHENING
MARINE LAYER. THE SOUTHERLY WINDS THAT DEVELOP ALONG THE COAST
WEDNESDAY MAY BE A BIT BREEZY AS WELL. TOLLESON
.LONG TERM...THE LOW THAT DROPPED SOUTH ALONG THE COAST DURING THE
EARLY PART OF THE FORECAST IS EXPECTED TO APPROACH THE OREGON COAST
THURSDAY AND MOVE NORTHEAST ACROSS SOUTHWEST WASHINGTON AND NORTHWEST
OREGON THURSDAY NIGHT AND EARLY FRIDAY. THIS WILL BRING AN INCREASED
CHANCE OF SHOWERS...WITH A FEW THUNDERSTORMS POSSIBLE DUE TO
INSTABILITY FROM THE COLD POOL ALOFT WITH THE UPPER LOW. THIS WILL
ALSO BRING A STRONG SOUTHWEST MARINE PUSH TO OUR FORECAST AREA WITH
WIDESPREAD CLOUDS AND COOLER TEMPS THROUGH FRIDAY. THE MODELS ARE
THEN GENERALLY DRY FOR THE WEEKEND BUT DIFFER ON HOW WARM IT WILL
BE...AND HAVE OPTED FOR A BLEND OF THE MODELS FOR NOW AS NORTHWEST
FLOW ALOFT PREVAILS. THE MODELS HINT AT ANOTHER TROUGH DROPPING DOWN
FROM THE NORTHWEST EARLY NEXT WEEK...BUT THE GFS IS STRONGER AND DIGS
IT MORE SOUTHWARD WHILE THE ECMWF KEEPS THE MAIN PART OF THE TROUGH
SLIDING BY TO OUR NORTH. HAVE OPTED TO STAY DRY FOR NOW BUT WITH SOME
ONSHORE FLOW CONTINUING/INCREASING. TOLLESON
&&
.AVIATION...VFR CONDITIONS WITH CIGS BETWEEN 10K-25K FT WILL
GENERALLY PERSIST NEXT 24 HRS FOR INLAND SITES. MVFR AND IFR CIGS
ALONG THE COAST WILL CONTINUE TONIGHT UNDER SOUTH-SOUTHWEST
FLOW...BUT CIGS APPEAR TO BE RISING PARTICULARLY ALONG THE N OR
COAST. EXPECT MOSTLY MVFR CIGS ON THE COAST THROUGH MORNING. FOR
MON...CHANCE OF TSRA FROM THE COAST RANGE EASTWARD IN THE LATE
AFTERNOON AND EVENING BUT WITH DISAGREEMENT AMONG MODELS...WILL LEAVE
OUT MENTION FOR NOW.
KPDX AND APPROACHES...VFR NEXT 24 HOURS. SLIGHT CHANCE SHRA OR TSRA
MAINLY AFTER 00Z. BOWEN
&&
.MARINE...NOT MUCH CHANGE TO THE FORECAST WITH WINDS BELOW ABOUT 15
KTS AND SEAS AROUND 4 FT THROUGH MUCH OF THE WEEK. WEAK SURFACE LOW
CURRENTLY SITS OFF THE WASHINGTON COAST OVER THE OFFSHORE WATERS BUT
BIGGEST IMPACT WILL BE VARIABLE WIND DIRECTION WITH A VARYING DEGREE
OF SOUTH OR WEST COMPONENT IN THE WIND AS THE LOW SLOWLY DRIFTS
THROUGH THE REGION OVER THE NEXT 48 HOURS. SURFACE HIGH PRESSURE
BUILDS OVER THE NE PACIFIC STARTING MIDWEEK AND ESPECIALLY INTO LATE
WEEK. THE NEXT THREAT FOR SMALL CRAFT ADVISORY STRENGTH WINDS LOOKS
TO BE AROUND FRIDAY AS THERMAL LOW PRESSURE DEEPENS ALONG THE N
CALIFORNIA/SW OREGON COAST. HOWEVER MODELS HAVE AT LEAST TEMPORARILY
BACKED OFF ON WINDS LATE WEEK.BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM NOON TODAY TO 11 PM PDT TUESDAY FOR
CENTRAL OREGON CASCADE FOOTHILLS-MT. HOOD NATIONAL FOREST
WEST OF CASCADE CREST-NORTH OREGON CASCADE FOOTHILLS-
WILLAMETTE NATIONAL FOREST.
WA...FIRE WEATHER WATCH FROM 1 PM PDT THIS AFTERNOON THROUGH LATE
TONIGHT FOR EXTREME SOUTH WASHINGTON CASCADES AND FOOTHILLS.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
258 AM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Northeast Blue Mountains
and Camas Prairie areas and propagating as far north as the Northeast
Mountains and Northern Panhandle. A few record high temperatures
may be set Wednesday. A cold front thursday will bring another
active thunderstorm threat along with cooler temperatures by next
weekend.
&&
.DISCUSSION...
...STRONG WINDS POSSIBLE WITH THUNDERSTORMS TODAY...
Today and Tonight: There are a couple of vorticity maximums to
watch out for today. Both are swinging around the base of a deep
upper level low pressure system off of the coast of WA. The first,
and more likely to have the bigger impact, is a shortwave
disturbance currently pushing into northern California early this
morning. This disturbance is progged to quickly push northeast and
begin to push up into the region between noon and 200 PM PDT.
Before we do see the effects of this disturbance, we will see some
lingering light shower activity mainly across the northern half of
the forecast area through this morning.
Satellite imagery indicates a lot of clearing occurring behind
these showers. This will set up a situation where there should be
plenty of sunshine for the atmosphere to destabilize by the
afternoon before the disturbance over California makes it this far
north. Moisture will increase across the region with dew points
expected to remain right around 50 degrees. This will set up the
ingredients for a decent amount of surface based CAPE to work
with. Models are generally showing somewhere in the neighborhood
of 500-1500 J/KG of surface based CAPE across the eastern half of
the forecast area; this generally includes areas east of a line
extending from Ritzville to Republic. Thunderstorms are expected
to initiate over northeast OR and in the southern Panhandle in the
early afternoon and the push northward into southeastern WA and
into the central Panhandle through the afternoon hours. Main
threats with the thunderstorms will be for strong outflow winds.
The WRF-NMM, WRF-ARW and HRRR models all show a signal of a gust
front emanating northward from the convection. These models have
also been consistent with this idea over the past few runs. I
increase winds across the Palouse, into the basin, the Spokane-
Coeur d`Alene corridor and into the northern mtns and ID
Panhandle. These winds may also result in blowing dust with
reduced visibility possible across portions of I-90 and highway 2.
Forecast confidence in the strong outflow winds and blowing dust
is only moderate and there is some bust potential as all the
ingredients need to come together. With that said, there is enough
evidence that concerns are increasing.
Thunderstorms are also expected to include frequent cloud to
ground lightning strikes. There will be some rain with the heavier
thunderstorm cores, but, away from these course, there will also
be a lot of evaporation that takes place. This should result in a
higher potential for new fire starts from lightning strikes. The
Fire Weather Watch will remain as is for now and will be
reassessed later in the morning.
A second disturbance will push up more across central OR in the
wake of the first. This piece of energy will spark off more
thunderstorms that will push northward through the late afternoon
hours. These thunderstorms will push into southern WA by the
evening, but much of the energy will begin to curl off to the
west. This should reduce the amount of forcing that enters the
region with this wave and is expected to result in thunderstorms
diminishing in intensity by this time. /SVH
Tues through Sunday: The Thurs/Fri ejection of the upper trough
still looks like the main focus as far as any widespread thunder
threat and post- frontal windy wx. The vast majority of model
guidance remain similar with digging the upper low S down the Pac
Nw coast. The primary challenge will be dealing with the ejection
of this low NE into Ern Wa and N Idaho Thurs & Fri. The ECMWF is
now only slightly faster to eject this wave NE, and both the GFS
and ECMWF continue with the trend of taking the low nearly
straight north across Wrn Wa and the Cascades. This would mean the
highest threat of thunder would be along and near the Cascades,
definitely NOT where we would prefer given the current wildfires
that may be enhanced by gusty outflow, not to mention new fire
starts. And if this Cascades pcpn is slow to exit, another issue
COULD be debris flows on current and recent burns. Though this is
the most important part of the fcst, it may not be the most
challenging part. As the wave digs S down the coast, Ern Wa and N
Idaho will be in a prolonged southerly fetch of increasing
moisture within a high- amplitude thermal ridge. This will not
only help to destabilize the sfc, but will also complicate matters
since there are at least three nocturnal subtle waves that move N
into Ern Wa through Wed. All of these accompany weak to moderate
convective/potential instability not rooted at the surface that
could produce a few overnight lightning strikes. Overnight low
temps will be very mild. And within the aforementioned thermal
ridge, Spokane may not be the only place that tops record high
temps Wed.bz
&&
.AVIATION...
06Z TAFS: A closed upper level low pressure system will remain
positioned off of the Washington Coast. Disturbance rotating
ahead of this low will move north and northeast and bring
increased mid level clouds along with some showers and
thunderstorms overnight tonight into Monday morning. Additional
disturbances will bring more potential for showers and
thunderstorms after 23Z Monday into the evening that could bring a
better chance of gusty wind. All TAF sites are expected to remain
VFR through 06Z tuesday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 91 64 97 66 100 69 / 20 40 10 20 10 10
Coeur d`Alene 92 59 97 63 99 65 / 30 40 10 20 10 10
Pullman 90 55 96 60 98 63 / 40 30 10 20 20 10
Lewiston 96 65 102 69 106 71 / 40 20 20 20 20 10
Colville 94 60 99 59 104 59 / 20 20 10 20 20 20
Sandpoint 90 54 95 59 98 57 / 20 30 10 20 20 20
Kellogg 92 56 96 60 98 63 / 30 50 10 20 10 20
Moses Lake 94 63 100 64 103 66 / 10 20 10 20 10 10
Wenatchee 94 72 99 70 102 75 / 10 30 10 20 20 10
Omak 96 66 101 66 102 67 / 20 30 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for Northern and Central Idaho Panhandle (Zone 101).
WA...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for East Washington Palouse and Spokane Area (Zone
674).
FIRE Weather Watch from this afternoon through late tonight for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1046 AM CDT MON AUG 10 2015
.UPDATE...
A 500MB TROUGH WILL SWING THROUGH THE GREAT LAKES REGION TODAY AND
TONIGHT. VORTICITY ADVECTION WITH AN EMBEDDED SHORTWAVE WILL LEAD TO
SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS SOUTH CENTRAL
AND SOUTHEAST WI NOW THROUGH 3 PM. THE 14Z HRRR RUN IS SHOWING THIS
BUT LOOKS A LITTLE OVERDONE. RADAR IS ALREADY SHOWING A FEW MORE
SHOWERS DEVELOPING ALREADY. THERE IS MODERATE INSTABILITY IN PLACE
OVER SOUTHERN WI WITH UP TO 1000 J/KG OF SURFACE-BASED CAPE. SHEAR
IS MINIMAL... SO NOT EXPECTING ANY SEVERE THUNDERSTORMS- JUST
SCATTERED STORMS WITH HEAVY DOWNPOURS. STORMS ARE SLOW-MOVING SO UP
TO A QUARTER INCH OF RAIN WOULD BE POSSIBLE WITH A SINGLE STORM.
THE SURFACE COLD FRONT ALREADY WENT THROUGH THE AREA EARLY THIS
MORNING... BUT THE UPPER LEVEL COLD FRONT WILL NOT CLEAR SOUTHERN WI
UNTIL LATE TONIGHT. THERE IS ONE MORE SHORTWAVE TO CROSS THE AREA
OVERNIGHT... BUT THAT SHOULD COME THROUGH DRY. THE COLUMN WILL BE
DRYING OUT AND IT IS ALSO COMING THROUGH DURING A DIURNALLY
UNFAVORABLE TIME OF DAY FOR CONVECTION.
&&
.AVIATION/18Z TAFS/...
SCATTERED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS SOUTH
CENTRAL AND SOUTHEAST WI LATE THIS MORNING AND WILL PERSIST THROUGH
MID AFTERNOON. THESE ARE DUE TO THE PASSAGE OF AN UPPER LEVEL COLD
FRONT AND THE DEVELOPMENT OF A LAKE BREEZE FRONT. AREAS OF MVFR CIGS
WILL BE POSSIBLE BY THE MIDDLE TO LATE MORNING WITH THE INITIAL
CUMULUS DEVELOPMENT BUT LIFT TO 3.5-5.0 KFT THROUGH THE AFTERNOON.
COLD AND DRY AIR ADVECTION TO PREVAIL TNT ON NLY WINDS SO FOG
POTENTIAL IS VERY LOW.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
TUESDAY THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
418 AM MDT MON AUG 10 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 222 AM MDT MON AUG 10 2015
TRANQUIL WEATHER CONDITIONS TO START THE FORECAST PERIOD WITH MOSTLY
CLEAR SKIES IN PLACE ACROSS THE REGION. THERE IS STILL THE POTENTIAL
FOR PATCHY FOG TO DEVELOP ALONG AND EAST OF THE LARAMIE RANGE GIVEN
WEAK UPSLOPE AND EXCELLENT LOW-LEVEL SATURATION INDICATED BY NAM/GFS
BUFKIT SOUNDINGS. THE HRRR HAS NOT BEEN OVERLY SUPPORTIVE...BUT WILL
MAINTAIN MENTION OF FOG THROUGH ABOUT 15Z...WHEN BOUNDARY LAYER RHS
SHOULD DECREASE. A STALLED N-S ORIENTED COLD FRONT ALONG THE LARAMIE
RANGE WILL SUPPORT CONTINUED LOW-LEVEL UPSLOPE TODAY. EXPECT SHOWERS
AND THUNDERSTORMS TO DEVELOP OVER THE MOUNTAINS AFTER 21Z...AND MOVE
EAST ONTO THE PLAINS THROUGH THE EVENING. CANNOT ENTIRELY RULE OUT A
STRONGER STORM OR TWO IF THE GFS VERIFIES WITH SBCAPE NEAR 1000 J/KG
ALONG THE I-80 CORRIDOR BETWEEN CYS-SNY...ESPECIALLY GIVEN 0 TO 6 KM
SHEAR IN EXCESS OF 35 KTS. SHOULD NOT BE LOOKING AT ANYTHING SEVERE
THOUGH.
A TYPICAL AUGUST WEATHER PATTERN WILL CONTINUE THROUGH MID WEEK WITH
UPPER-LEVEL RIDGING THE DOMINANT FEATURE. SOUTHWEST FLOW ALOFT WILL
YIELD A PERSISTENT FEED OF MONSOONAL MOISTURE...GIVING WAY TO DAILY
CHANCES FOR CONVECTION GENERALLY ALONG AND WEST OF THE LARAMIE RANGE
ON TUESDAY AND WEDNESDAY AFTERNOONS. A GRADUAL WARMING TREND CAN BE
EXPECTED AS RIDGING STRENGTHENS...AND H7 TEMPS INCREASE TO NEAR +16
DEG C BY 00Z THU. SHOULD SEE MORE WIDESPREAD 90S FOR AFTERNOON HIGHS
BY THE END OF THE PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 222 AM MDT MON AUG 10 2015
ALL MEDIUM TO LONG RANGE MODELS SHOW THE UPPER LEVEL HIGH...CENTERED
NEAR THE FOUR CORNERS REGION...DOMINATING THE WEATHER PATTERN LATE
THIS WEEK AND INTO NEXT WEEKEND. THE HIGH SHOWS SOME SIGNS OF
RETROGRADING OR WEAKENING BY NEXT WEEKEND...AS ENERGY FROM THE
NORTHERN PACIFIC DIVES SOUTHEAST INTO THE NORTHWEST UNITED STATES.
ANY NOTICEABLE CHANGES TO THE PATTERN ARE NOT EXPECTED TO OCCUR
OVER THE NEXT 7 DAYS THOUGH...SO EXPECTED PERSISTENT SOUTHWEST
FLOW ALOFT AND ADVECTION OF MONSOON MOISTURE LATE THIS WEEK AND
NEXT WEEKEND. HIGH TEMPERATURES WILL BE ABOVE NORMAL THROUGH
SATURDAY WITH READINGS IN THE 80S TO LOW 90S ACROSS MOST OF THE
AREA. PORTIONS OF WESTERN NEBRASKA AND FAR EASTERN WYOMING WILL
LIKELY REACH THE MID TO UPPER 90S ON FRIDAY AS 700MB TEMPERATURES
PEAK BETWEEN 15C TO 18C. WITH PW/S INCREASING TO OVER ONE
INCH ACROSS THE FRONT RANGE...THERE WILL BE PLENTY OF MOISTURE FOR
SHOWERS AND TSTORMS TO DEVELOP OVER THE HIGHER TERRAIN. NOT
CONFIDENT ON THE COVERAGE AT THIS TIME...BUT SOME OF THESE TSTORMS
MAY CONTAIN VERY HEAVY RAINFALL. IN ADDITION...SHOWERS AND TSTORMS
WILL NOT MOVE ALL THAT MUCH THROUGH EACH AFTERNOON. THUS THERE IS
SOME CONCERN FOR FLASH FLOODING. KEPT POP BETWEEN 20 TO 30 PERCENT
FOR THE HIGH VALLEYS AND HIGH PLAINS...WITH VALUES CLOSER TO 50
PERCENT IN THE MOUNTAINS. SEVERE TSTORMS APPEAR UNLIKELY AT THIS
TIME DUE TO THE LACK OF SHEAR ACROSS THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)
ISSUED AT 300 AM MDT MON AUG 10 2015
MVFR CIGS AND PATCHY FOG IS EXPECTED EARLY THIS MORNING BEFORE
LIFTING BY 15Z OVER MOST TERMINALS. LOW CLOUDS MAY LINGER THROUGH
THE DAY OVER KSNY...KAIA...AND KCDR HOWEVER. ANOTHER ROUND OF
SHOWERS AND TSTORMS ARE EXPECTED MAINLY OVER SOUTHEAST WYOMING
THIS AFTERNOON AND INTO THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 222 AM MDT MON AUG 10 2015
NO MAJOR FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. NON-CRITICAL
CONDITIONS ARE EXPECTED WITH WIND GUSTS EXPECTED TO REMAIN BELOW 25
MPH AND HUMIDITIES GENERALLY ABOVE 20 PERCENT WITH GOOD TO EXCELLENT
RECOVERY OVERNIGHT. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS COULD
OCCUR EACH AFTERNOON THROUGH THE WEEK. THE MAIN HAZARD FROM THESE
STORMS WILL BE GUSTY AND ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
942 AM MST MON AUG 10 2015
.SYNOPSIS...
SOUTHERLY FLOW ALOFT WILL GRADUALLY INCREASE MOISTURE
LEVELS ACROSS THE REGION TODAY THROUGH TUESDAY...WITH TUESDAY
AFTERNOON AND EVENING SEEING THE BEST CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS SOUTH CENTRAL ARIZONA. VERY STRONG HIGH
PRESSURE ALOFT BUILDING INTO THE REGION FROM THE EAST WILL THEN
BRING MUCH ABOVE NORMAL TEMPERATURES AND REDUCE THUNDERSTORM CHANCES
FROM WEDNESDAY ONWARD INTO SATURDAY...WITH COOLER TEMPERATURES AND
BETTER CHANCES FOR STORMS RETURNING FROM SUNDAY ONWARD INTO EARLY
NEXT WEEK.
&&
.DISCUSSION...
DEBRIS CLOUDINESS PERSISTS THIS MORNING ACROSS EAST-CENTRAL AZ BUT IS
SHOWING SIGNS OF BREAKING APART. HIGH-RES WRFS ARE EXHIBITING
SOMEWHAT MORE VARIABILITY THIS MORNING IN THE PLACEMENT OF THE
AFTERNOON CONVECTION...THOUGH THE CONSENSUS IS THAT ACTIVITY WILL BE
MOST LIKELY FROM PHOENIX EASTWARD. LATEST RUNS OF THE HRRR INDICATE
THAT THE MORNING CLOUDS WILL INHIBIT CONVECTION...SUGGESTING ONLY
ISOLATED STORMS LATE THIS AFTERNOON...MAINLY ACROSS NORTHERN GILA
COUNTY.
SHORT-TERM UPDATES TO THE FORECAST ARE NEEDED THIS MORNING...MAINLY
TO ACCOUNT FOR THE DELAYED RISE IN TEMPERATURES. OTHERWISE...THE
FORECAST REMAINS ON TRACK.
&&
.PREVIOUS DISCUSSION...
IT NOW APPEARS THAT TUESDAY WILL LIKELY BE THE MOST ACTIVE DAY...AS
THE FLOW ALOFT BECOMES SOUTHERLY THROUGH THE WHOLE COLUMN WITH LESS
CLOUDINESS LIKELY ON TUESDAY MORNING THEN WHAT WE ARE SEEING
TODAY...WITH SOME DECENT MID-LEVEL SHEAR PERHAPS ENHANCING THE
THUNDERSTORM INTENSIFY/COVERAGE...AND AT LEAST SOME STORM ACTIVITY
WORKING ITS WAY INTO SW AZ.
WEDNESDAY THROUGH SATURDAY...
IT NOW LOOKS INCREASINGLY LIKELY THAT WE WILL SEE SOME VERY HOT
TEMPERATURES DURING THIS PERIOD AS THE MAIN LONG-WAVE PATTERN RE-
ADJUSTS ITSELF OVER NORTH AMERICA...WITH RATHER DEEP TROFING DROPPING
DOWN INTO THE GREAT LAKES/NE US...AND THE MAIN UPPER RIDGE AXIS BEING
FORCED WESTWARD OVER THE DESERT SW. EVEN THOUGH OUR MID/UPPER-LEVEL
FLOW IS EXPECTED TO REMAIN MAINLY FROM A SE-LY DIRECTION DURING THIS
PERIOD...WHICH NORMALLY IS THE BEST DIRECTION FOR MONSOON MOISTURE TO
BE IMPORTED INTO THE REGION...THE UPPER HIGH CENTER THAT IS FORECAST
TO BUILD OVER OUR REGION IS EXPECTED TO BE QUITE STRONG...WITH 500MB
HEIGHTS RISING INTO THE 596-598DM RANGE BY THU-FRI. THIS UPPER HIGH
CENTER...WHICH HAS BEEN CENTERED OVER THE GULF COAST REGION THE LAST
FEW DAYS...HAS BROUGHT THAT REGION VERY HOT AND DRY CONDITIONS...WITH
HIGHS APPROACHING OR EXCEEDING 100 DEGREES AT MANY
LOCATIONS...INCLUDING HOUSTON AND NEW ORLEANS. STRONG SUBSIDENCE
ALOFT HAS COMPLETELY SHUT DOWN THE CONVECTION THAT NORMALLY KEEPS
HIGHS DOWN IN THE LOW-MID 90S AT THESE COASTAL LOCATIONS...AND IT
APPEARS THAT THIS SUBSIDENCE IS HEADED OUR WAY...AS INDICATED ON THE
LATEST FORECAST SOUNDINGS. THUS...IT APPEARS THAT THUNDERSTORM
ACTIVITY WILL BE NOTICEABLY REDUCED DURING THIS PERIOD...WITH MOST
ACTIVITY BEING CONFINED TO THE HIGHER TERRAIN OF SOUTH-CENTRAL AND SW
AZ. THIS LACK OF CONVECTIVE ACTIVITY/INCREASED SUNSHINE ALONG WITH
VERY WARM AIR ALOFT (500MB TEMPS IN THE -3C TO -4C RANGE) IS ALSO
EXPECTED TO ALLOW OUT TEMPERATURES TO RISE WELL ABOVE NORMAL...WITH
WIDESPREAD READINGS IN THE 110-115F RANGE ACROSS THE LOWER DESERTS.
THESE VERY HOT DAYS ALONG WITH NIGHTTIME LOWS NEAR 90 AT THE WARMER
URBAN LOCATIONS MAKES THE ISSUANCE OF HEAT PRODUCTS LATER THIS WEEK
VERY LIKELY...ESPECIALLY FOR THE THU-FRI TIME PERIOD.
SUNDAY AND MONDAY...
ALTHOUGH SOME MODEL DISAGREEMENT DOES CROP UP DURING THIS
PERIOD...IT APPEARS LIKELY THAT THE RIDGING OVER THE DESERT SOUTHWEST
WILL BEGIN TO WEAKEN...WITH COOLER TEMPERATURES AND A BETTER CHANCE
FOR THUNDERSTORMS RETURNING TO THE REGION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A REMNANT CIRCULATION CENTER NEAR TUCSON WILL ROTATE THROUGH THE
PHOENIX AREA THIS MORNING. AT THIS POINT IT APPEARS THE ONLY IMPACT
WILL BE INCREASED MID LEVEL CLOUDS AND POSSIBLY A FEW SPRINKLES...BUT
THAT`S ABOUT IT. LOOKING AHEAD TO THIS AFTERNOON...STORMS ARE
POSSIBLE SOUTH/EAST OF PHOENIX BUT ARE EXPECTED TO DISSIPATE BEFORE
REACHING ANY OF THE PHOENIX TERMINALS. MOST LIKELY IMPACT WOULD BE A
MID EVENING SOUTHEASTERLY OUTFLOW SOME TIME BETWEEN 03Z-06Z. WILL
LEAVE ALL OTHER WEATHER OUT OF THE TAFS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DISTANT HIGH CLOUDS SHOULD BE THE ONLY IMPACT AT BOTH SE CA SITES.
WINDS SHOULD BE LIGHT /CAN`T RULE OUT AN OCCASIONAL LATE DAY GUST/ AND
FOLLOW DIURNAL TENDENCIES.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
MONSOON MOISTURE WILL LINGER OVER THE REGION WEDNESDAY BEFORE SOME
DRIER AIR BEGINS TO ADVECT INTO THE AREA. SLIGHT CHANCES FOR STORMS
WILL CONTINUE...BEFORE TAPERING OFF HEADING THROUGH THE LATE WEEK
AND INTO THE EARLY WEEKEND. AS HUMIDITIES AND DEWPOINTS BEGIN TO
SLOWLY DROP...TEMPERATURES WILL BEGIN TO WARM AND HEADING ABOVE
SEASONAL NORMALS FOR THE END OF THE WEEK. WINDS WILL GENERALLY BE
LIGHT THROUGH THE MAJORITY OF THE FORECAST PERIOD WITH
PERIODS OF UPSLOPE AFTERNOON GUSTINESS.
&&
.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
PREVIOUS DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
346 PM MDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
TSRA MOST NUMEROUS THIS AFTERNOON OVER THE PLAINS SOUTH OF THE
ARKANSAS RIVER...THOUGH AN ISOLATED CELL OVER TELLER AND EL PASO
COUNTIES EARLIER IN THE DAY MANAGED TO PRODUCE FLASH FLOODING OVER
WESTERN PORTIONS OF COLORADO SPRINGS AND THE EASTERN EDGE OF THE
WALDO CANYON BURN SCAR. MAIN QUESTION FOR TONIGHT WILL REVOLVE
AROUND LOCATION OF HEAVIER RAINFALL AND HOW LATE WILL STORMS
PERSIST INTO TUE MORNING. 19Z/20Z RUNS OF THE HRRR BRING ANOTHER
WAVE OF TSRA AND HEAVY RAIN THROUGH EL PASO COUNTY 00Z-02Z...THEN
ACROSS PUEBLO COUNTY AND NORTHERN PORTIONS OF THE ARKANSAS VALLEY
02Z-05Z. 12Z VERSIONS OF THE NAM/NAM 4KM/NSSL WRF ON THE OTHER
HAND...KEEP HEAVIEST RAINFALL MAINLY OVER THE MOUNTAINS
OVERNIGHT...WITH FOCUS FOR MOST TSRA SHIFTING TOWARD THE SAN JUAN
MOUNTAINS AFTER 06Z AS AREA OF DEEP TROPICAL MOISTURE OVER THE 4
CORNERS ROTATES NORTHEASTWARD. FORECAST LEANS A LITTLE TOWARD THE
HRRR...AS LAPS CAPES ARE STILL ABOVE 1000 J/KG OVER THE EASTERN
MOUNTAINS AND I-25 CORRIDOR...SUGGESTING ANOTHER BOUT OF TSRA IS
POSSIBLE. CONSIDERED A FLASH FLOOD WATCH FOR EL PASO COUNTY FOR
THIS EVENING AS HEAVY RAIN HAS FALLEN ACROSS THE REGION...THOUGH
WITH HRRR SHIFTING AXIS OF STRONGER STORMS SOUTH FAIRLY
QUICKLY...WILL REFRAIN FROM ISSUANCE AT THIS POINT. POCKETS OF
HEAVY RAIN LOOK POSSIBLE FARTHER SOUTH OVER THE PLAINS...BUT MOST
AREAS HAVE BEEN DRY ENOUGH LATELY TO TAKE AT LEAST A COUPLE HOURS
OF HEAVER PRECIP. PRECIP SLOWLY WANES OVERNIGHT...BUT NEVER
COMPLETELY COMES TO AN END...SO WILL KEEP SOME POPS GOING MANY
AREAS INTO EARLY TUE MORNING.
ON TUE...MOISTURE REMAINS IN PLACE...THOUGH HEIGHTS BEGIN TO BUILD
SLIGHTLY AS UPPER HIGH STARTS ITS NORTHWARD EXPANSION. STILL
APPEARS MOST LOCATIONS WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE AGAIN...THOUGH EXTENT OF OVERNIGHT CONVECTION
AND POTENTIAL MCS OVER THE EASTERN PLAINS/NERN NM WILL LIKELY PLAY
A ROLE IN AMOUNT OF CONVECTIVE COVERAGE...ESPECIALLY OVER THE
PLAINS WHERE EARLY MORNING SHOWERS COULD LIMIT INSTABILITY. BROAD-
BRUSH OF SCATTERED POPS LOOKS FINE...AND WITH MOISTURE LEVELS
REMAINING RELATIVELY HIGH...LOCALLY HEAVY RAINFALL WILL AGAIN BE
POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
UPPER RIDGE EXPANDS NORTHWARD WED-FRI...WITH THE UPPER LEVEL HIGH
PRESSURE CENTER REMAINING ALONG THE CO/NM BORDER THROUGH THE
PERIOD. TRAPPED MOISTURE UNDER THE HIGH WILL CONTINUE TO BE
RECYCLED...WITH DAILY AFTERNOON/EVENING TSRA OVER THE
MOUNTAINS...THOUGH COVERAGE MAY BECOME RATHER SPARSE WED/THU AS
TEMPERATURES ALOFT WARM. PLAINS/VALLEY TSRA CHANCES LOOK FAIRLY
LOW...THOUGH TOUGH TO RULE OUT A COUPLE STORMS DRIFTING AWAY FROM
THE MOUNTAINS EACH DAY...ESPECIALLY ALONG AND WEST OF I-25.
FORECAST HAS LOW POPS FOR ALL AREAS EACH DAY WED-FRI...WHICH MAY
BE A LITTLE OVERDONE...BUT WILL RUN WITH FOR NOW. RIDGE FLATTENS
SLIGHTLY FRI INTO THE WEEKEND...WHILE WEAK FRONT OOZES INTO THE
EASTERN PLAINS LATE SUN. EXPECT A GRADUAL INCREASE IN TSRA CHANCE
MOST LOCATIONS AS SLIGHTLY DEEPER MOISTURE MOVES IN FROM THE
WEST...WHILE LOW LEVELS ON THE PLAINS MOISTEN AND WLY STEERING
CURRENTS BECOME MORE FAVORABLE FOR STORMS TO MOVE ONTO THE PLAINS.
TEMPS FROM WED INTO THE WEEKEND WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 235 PM MDT MON AUG 10 2015
SCATTERED TO NUMEROUS TSRA WERE OVER THE AREA THIS AFTERNOON WITH
THE GREATEST COVERAGE OF STORMS SOUTH OF THE ARKANSAS RIVER. WHILE
KPUB AND KCOS ARE CURRENTLY FREE OF CONVECTION AS OF
21Z...MESOSCALE MODELS INDICATE ANOTHER ROUND OF TSRA DROPPING
SOUTH THROUGH KCOS 00Z-02Z...THEN THROUGH KPUB 01Z-03Z...SO WILL
MAINTAIN A VCTS MENTION BOTH SITES UNTIL AROUND 03Z. AT
KALS...WILL ALSO KEEP VCTS IN THE TAF INTO THE EVENING AS
WELL...WITH STORMS ENDING 01-03Z. OVERNIGHT...TSRA MAY LINGER OVER
THE PLAINS EAST OF I-25 MUCH OF THE NIGHT...WITH A THREAT OF
SHOWERS AT TAF SITES 03Z-09Z. ON TUESDAY...TSRA WILL DEVELOP LATE
MORNING OVER THE MOUNTAINS...THEN SPREAD TO LOWER
ELEVATIONS...INCLUDING ALL TAF SITES IN THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS PEACHTREE CITY GA
152 PM EDT MON AUG 10 2015
.PREV DISCUSSION... /ISSUED 413 AM EDT MON AUG 10 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT WILL IMPACT THE CWFA IN THE SHORT TERM PORTION OF THE
FORECAST AREA. THE FRONT CURRENTLY STRETCHES FROM THE MID
MISSISSIPPI RIVER VALLEY TO THE TENNESSEE VALLEY. THE BOUNDARY WILL
SLIP SLOWLY SOUTH TODAY...AND CROSS MUCH OF THE FORECAST AREA ON
TUESDAY.
DEWPOINTS HAVE BEGUN TO CREEP UP ACROSS THE CWFA...A SIGN OF
INCREASING LOW LEVEL MOISTURE. PRECIPITATION CHANCES WILL INCREASE
TODAY AHEAD OF THE FROPA. HI-RES MODELS ARE SHOWING A RATHER
ORGANIZED LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTH ACROSS
NORTH AND CENTRAL GA THIS AFTERNOON. THE LOCAL WRF AND THE HRRR DO
DIFFER A BIT...WITH THE WRF BEING LATER WITH THE CONVECTION. HAVE
TRIED TO COMPROMISE ON TIMING. BOTH MODELS...HOWEVER...INDICATE VERY
GOOD RAIN CHANCES ACROSS NORTHERN GA TODAY. SO...HAVE RAISED POPS TO
LIKELY IN THAT REGION.
ATMOS WILL BE FAVORABLE FOR STRONG TO ISOLATED SEVERE STORMS. GOOD
SURFACE INSTABILITY WILL BE PRESENT...WITH AN ASSIST BY A SHORTWAVE
DROPPING SOUTH IN THE MID LEVEL FLOW. MODELS CURRENTLY KEEP LAPSE
RATES FAIRLY WEAK...BUT THE SHORTWAVE WILL PROVIDE SOME LIFT.
COPIOUS CLOUD COVER SHOULD HELP LIMIT SEVERE STORM COVERAGE.
THE MAIN FOCUS FOR TODAYS CONVECTION SHOULD BE ANY
OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FROM THE THUNDERSTORM
COMPLEX CURRENTLY ACROSS THE MID MISSISSIPPI RIVER VALLEY. THE
ACTUAL FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR STORMS TOMORROW.
TEMPS SHOULD BE A FEW DEGREES COOLER THAN YESTERDAYS VALUES DUE TO
THE INCREASED CLOUD COVER. TEMP/DEWPOINT VALUES REMAIN BELOW
CRITICAL THRESHOLDS FOR A HEAT ADVISORY AT THIS TIME.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE IN DECENT AGREEMENT WITH AFOREMENTIONED FRONTAL BOUNDARY
IN THE SHORT TERM LINGERING ACROSS THE SOUTHERN TIER OF THE CWA
FOR TUESDAY NIGHT INTO WEDNESDAY...THEN FINALLY PUSHING JUST SOUTH
OF THE AREA AND BECOMING MORE DIFFUSE THRU THE REST OF THE WORK
WEEK. HAVE TRENDED CHANCE TO SLIGHT POPS ACCORDINGLY AND ADVECTION
OF ABNORMALLY DRY AIR IN FROM THE NW WILL ALLOW FOR A RATHER
PLEASANT WED AND THURS WITH SLIGHTLY BELOW NORMAL HIGHS AND
RESULTANT AFTERNOON RH VALUES IN THE 40S.
FOR FRIDAY INTO THE WEEKEND...A BROAD/WEAK AREA OF LOW PRESSURE
LOOKS TO DEVELOP ACROSS THE NORTHERN GULF OF MEXICO ALLOWING FOR
SOME LOW LEVEL MOISTURE TRANSPORT OFF THE ATLANTIC. HAVE CONTINUED
TO ADVERTISE A RETURN OF SLIGHT TO LOW END CHANCE POPS FOR PORTIONS
OF THE AREA...MAINLY FOR DIURNALLY DRIVEN CONVECTION. NO OTHER CLEAR
FORCING MECHANISM LOOKS TO BE PRESENT SO NOT EXPECTING ANYTHING
WIDESPREAD AND RATHER STAGNANT AIRMASS IN PLACE SO DEVELOPMENT
SHOULD BE TYPICAL SUMMERTIME OUTFLOW DRIVEN. TEMPS SHOULD BE
SLIGHTLY WARMER THAN MIDWEEK BUT CLOSE TO NORMAL OR SLIGHTLY BELOW
WITH ENHANCED CLOUD COVERAGE.
BAKER
&&
.AVIATION...
18Z UPDATE...
CURRENT RADAR SHOWS SCATTERED SHOWERS DEVELOPING AROUND ALL TAF
SITES. A MORE ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS WAS NOTED
OVER NE AL AND MOVING ESE. HI-RES MODELS BRING TH MORE ORGANIZED
CONVECTION TO THE NW ACROSS THE ATLANTA AREA TAF SITES BETWEEN 20-
24Z. WILL CONTINUE TO SHOW TEMPO TSRA 20-24Z FOR NOW... WITH VCSH
HANDLING THE CURRENT SHOWERS UNTIL 20Z. SCATTERED SHOWERS MAY LINGER
OVERNIGHT... WITH MVFR CIGS EXPECTED TO SETTLE IN OVER MOST TAF
SITES BY 09Z TUE... THEN PERSIST THROUGH 15-16Z TUE. A PRE-FRONTAL
TROUGH SHOULD PUSH SOUTH OF ATLANTA TAF SITES BY 17-18Z... WITH A
DRIER NW FLOW SPREADING VFR CONDITIONS INTO THE AREA TUE AFTERNOON.
//ATL CONFIDENCE...18Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
/39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 72 89 71 / 40 40 30 30
ATLANTA 90 74 88 72 / 40 40 30 20
BLAIRSVILLE 84 67 83 63 / 60 40 30 10
CARTERSVILLE 90 71 88 68 / 60 40 30 20
COLUMBUS 93 76 91 74 / 40 30 40 40
GAINESVILLE 87 72 87 71 / 60 40 30 20
MACON 92 74 90 73 / 40 30 40 40
ROME 91 72 89 68 / 60 40 30 10
PEACHTREE CITY 91 72 89 70 / 40 30 30 30
VIDALIA 92 73 92 74 / 30 20 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
509 PM CDT MON AUG 10 2015
.MESOSCALE DISCUSSION...
349 PM CDT
THREE LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE TO TRACK
SOUTHWARD FROM CENTRAL WISCONSIN TO NORTHERN ILLINOIS. THE FIRST
LINE...NOW EXTENDING FROM LONG POINT TO DE MOTTE...HAS LOST MUCH OF
ITS STRENGTH AS THE OUTFLOW BOUNDARY HAS OUTRUN THE MAIN LINE OF
STORMS. THIS OUTFLOW HAS SHOWN GUSTS OF 25KT AT IKK WITH SIMILAR
VALUES EXPECTED FOR THE REMAINDER OF ITS LIFE IN THE CWA. SINCE THIS
LINE HAS THE MOST UNTAPPED INSTABILITY TO WORK WITH...A FEW GIRTHY
YET SUB-SEVERE STORMS ARE POSSIBLE.
THE MIDDLE LINE OF STORM EXTENDING FROM BUFFALO TO NORTH CHICAGO IS
CURRENTLY SHOWING THE MOST UPWARD GROWTH AND OUTFLOW INTERACTIONS.
DOPPLER RADAR SHOWS NUMEROUS OUTFLOW WAVES FROM MULTIPLE PREVIOUS
STORMS. THESE INTERACTIONS CAN ACT TO CREATE LOW LEVEL WIND SHEAR
AND MAY PROMPT BRIEF FUNNEL CLOUD DEVELOPMENT. ONE CELL IN
PARTICULAR FROM CAROL STREAM HEADED SOUTH TOWARD DOWNERS GROVE HAS
SHOWN NEARLY 60 DBZ OF REFLECTIVITY ABOVE THE -20C LINE. 1 INCH HAIL
IS NOT OUT OF THE QUESTION WITH CELLS SIMILAR TO THIS OVER THE NEXT
2-3 HOURS WHILE DAYTIME HEATING IS STILL ABUNDANT. EXPECT CONTINUED
INTERACTIONS TO ALSO FUEL CELL GROWTH. IN THIS REGIME...EVEN
VERTICALLY CHALLENGED CELLS MAY SHOW SIGNS OF BRIEF ROTATION...BUT
WIDESPREAD TORNADIC ACTIVITY IS NOT ANTICIPATED.
THE THIRD/NORTHERLY LINE MARKS A COLD FRONT WHERE DEWPOINT
TEMPERATURES DROP ROUGHLY 10 DEGREES. THIS LINE HAS THE MOST
SUFFICIENT FORCING MECHANISM...BUT LITTLE IN THE WAY OF INSTABILITY.
THE FRONT WILL BE HALFWAY ACROSS THE CWA BY 23Z (MENDOTA TO
PLAINFIELD TO GARY)...AT WHICH POINT THE LOSS OF DAYTIME HEATING IS
EXPECTED TO CEASE REMAINING THUNDER CHANCES. THIS IS SUPPORTED BY
THE EXPERIMENTAL HRRR THAT SUGGESTS ISOLATED LINGERING SHOWERS
THROUGH 00Z.
MM
&&
.SHORT TERM...
237 PM CDT
THROUGH TONIGHT...
A SERIES OF SHORTWAVE TROUGHS CONTINUE TO TRACK SOUTHEAST ACROSS THE
REGION GENERATING BANDS OF SHOWERS AND THUNDERSTORMS. THE FIRST WAVE
IS CROSSING FAR SOUTHERN LAKE MICHIGAN PUSHING A BAND OF SHOWERS AND
STORMS SOUTHWARD ALONG THE I-80 CORRIDOR AT THIS TIME WITH ANOTHER
CLUSTER OUT OVER LAKE MICHIGAN. WITH THE MOVEMENT OF THE WAVE
HAVING AN EASTWARD COMPONENT THE BETTER LARGER SCALE FORCING WILL
BE SHIFTING AWAY FROM THE CURRENT BAND OF ACTIVITY ALONG I-80 SO
THIS AREA MAY START TO FADE IN COVERAGE OVER THE NEXT COUPLE HOURS.
IN ADDITION...OUTFLOW IS NOW OUTRUNNING THE CONVECTION SUPPORTING A
DOWNWARD TREND. HOWEVER...WITH AN UNSTABLE AIRMASS IN PLACE THE
OUTFLOW MAY GENERATE NEW STORMS SOUTH OF I-80 BUT THE EXITING OF THE
UPPER FORCING SUGGESTS MORE ISOLATED COVERAGE TO ANYTHING
ADDITIONAL. AREAS OF NORTHWEST INDIANA PROBABLY HAVE THE BEST CHANCE
FOR RENEWED DEVELOPMENT FROM THIS FIRST WAVE THROUGH LATE AFTERNOON.
ATTENTION TURNS TO A SECOND WAVE TRACKING ACROSS CENTRAL WISCONSIN
WHICH IS GENERATING SCATTERED CONVECTION ACROSS MUCH OF SOUTHERN
WISCONSIN. THIS ACTIVITY IS MORE DISJOINTED IN COVERAGE BUT WILL
LIKELY CONTINUE INTO NORTHERN ILLINOIS INTO LATE AFTERNOON...WITH
ADDITIONAL DEVELOPMENT ACROSS NORTHERN ILLINOIS IN THE MEANTIME.
STORM ORGANIZATION WILL LIKELY BE A BIGGER CHALLENGE NORTH OF I-80
GIVEN THE PREVIOUS ACTIVITY BUT SOME BRIEF PULSING OF UPDRAFTS MAY
PRODUCE SOME SMALL HAIL AND SOME SUB SEVERE WIND GUSTS. A SUBTLE
COOL FRONTAL BOUNDARY WILL BRING A PUSH OF DRIER AIR INTO THE AREA
EARLY THIS EVENING AS THE UPPER WAVE EXITS. THIS WILL BRING AN END
TO ANY CONVECTION. WILL KEEP A MINIMAL CHANCE FOR POPS VERY EARLY
THIS EVENING. OTHERWISE DRY WEATHER IS EXPECT TONIGHT. CANNOT RULE
OUT SOME PATCHY FOG LATE ACROSS SOUTHERN AREAS WHERE WINDS WILL BE
LIGHTEST BUT THERE MAY BE ENOUGH OF A BREEZE TO MITIGATE ANY
DEVELOPMENT. FURTHER NORTH...DECREASING DEWPOINTS AND A SLIGHT
BREEZE SHOULD FURTHER REDUCE THE CHANCE FOR FOG DEVELOPMENT.
MDB
&&
.LONG TERM...
TUESDAY THROUGH MONDAY...
306 PM...MAIN FORECAST CONCERN IS PRECIP CHANCES THURSDAY NIGHT
THRU FRIDAY NIGHT AND AGAIN SUNDAY NIGHT INTO MONDAY.
HIGH PRESSURE WILL BUILD ACROSS THE REGION TUESDAY AND TUESDAY NIGHT
AND THEN SLOWLY SAG SOUTHEAST OF THE AREA WEDNESDAY NIGHT INTO
THURSDAY. THIS WILL PROVIDE DRY WEATHER WITH NORTHEAST WINDS OFF THE
LAKE TUESDAY AND THEN A LAKE BREEZE WEDNESDAY...KEEPING AREAS NEAR
THE LAKE A FEW DEGREES COOLER BUT WITH MOSTLY SUNNY SKIES...TEMPS
INLAND SHOULD REACH AROUND 80 BOTH DAYS.
WINDS TURN SOUTHWESTERLY WEDNESDAY NIGHT AS THE LOW LEVELS BEGIN TO
WARM SOME OVERNIGHT. NOT SURE HOW LOW TEMPS WILL DROP NOW WEDNESDAY
NIGHT INTO THURSDAY MORNING WITH THIS WARMING ALOFT. STILL POSSIBLE
FOR SOME MID/UPPER 50S LOW TEMPS AWAY FROM URBAN AREAS AND PERHAPS
MOST LIKELY INTO NORTHWEST INDIANA. THURSDAY LOOKING TO BE A BREEZY
WARM DAY AS HIGHS REBOUND BACK INTO THE MID 80S.
AN UPPER LEVEL WAVE IS EXPECTED TO MOVE ACROSS THE WESTERN LAKES
REGION THURSDAY NIGHT INTO FRIDAY WHICH WILL BE THE NEXT CHANCE FOR
SHOWERS/THUNDERSTORMS. OVERALL CONFIDENCE IS SOMEWHAT LOW REGARDING
COVERAGE/TIMING BUT CHANCE POPS INTO FRIDAY EVENING LOOK REASONABLE.
WINDS WILL LIKELY TURN OFF THE LAKE POSSIBLY FRIDAY AFTERNOON BUT
ESPECIALLY ON SATURDAY.
THE UPPER RIDGE BUILDS BACK INTO THE REGION SUNDAY INTO MONDAY.
TEMPS WILL LIKELY RISE BACK INTO THE MID...PERHAPS UPPER 80S DURING
THIS TIME PERIOD WITH A STRONGER COLD FRONT MOVING SOUTH INTO THE
UPPER MIDWEST/NORTHERN LAKES REGION SUNDAY/SUNDAY NIGHT. STILL
TIMING DIFFERENCES WITH HOW FAST THIS FRONT MOVES SOUTH ACROSS THE
AREA EARLY NEXT WEEK. OUTSIDE OF ANY LAKE COOLING...APPEARS HIGHS
IN THE MID 80...PERHAPS UPPER 80S...IS ON TRACK FROM THURSDAY
UNTIL THIS FRONT ARRIVES EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* ISOLATED SHRA NEXT 2-3 HOURS...THOUGH TSRA COVERAGE DECREASING
VCNTY ORD/MDW AND BECOMING FOCUSED MAINLY SOUTH-SOUTHWEST OF
THE TERMINALS.
* NORTHERLY WINDS AT OR BELOW 10 KTS...THOUGH DIRECTION VARIABLE
AT TIMES INTO EARLY EVENING WITH SHRA OUTFLOW.
* LAKE BREEZE DEVELOPMENT TUESDAY AFTERNOON.
MM/RATZER
//DISCUSSION...UPDATED 18Z...
LINE OF THUNDERSTORMS ALONG A NOW DEFINED BOUNDARY CONTINUES TO
SWEEP ACROSS THE CHICAGO TERMINALS EARLY THIS AFTERNOON. MAIN
CELLS APPEAR TO MISS ORD AND MDW...WITH VICINITY THUNDER COVERING
THIS FEATURE. SECOND BOUNDARY APPEARS TO ENTER THE AIRSPACE AROUND
20Z AS NOTED IN WEAK RADAR RETURNS IN CENTRAL WISCONSIN. THE
INITIAL LINE SHOULD LOWER INSTABILITY...LEAVING LESS ENERGY FOR
THE SECOND BOUNDARY TO TAP INTO. HAVE LEFT VCSH IN THE TAF WITH NO
MENTION OF THUNDER. FORECAST SOUNDINGS STILL SHOW LAPSE RATES
IN THE 8-10 C/KM RANGE WITH CONVECTIVE TEMPS OF 80F...SO THUNDER IS
NOT COMPLETELY OUT OF THE QUESTION IN THE 20-23Z TIMEFRAME.
BEHIND THE BOUNDARY...MAINLY VFR CONDITIONS ARE LIKELY FOR AN
EXTENDED PERIOD OF TIME. WHILE OUTLYING AREAS MAY SEE PATCHY AM
FOG...THE CHICAGO TERMINALS SHOULD STAY VFR. THE FOLLOWING FEW
DAYS WILL ALLOW FOR LAKE BREEZE CHANCES GENERALLY INITIALIZING IN
THE 19-22Z TIMEFRAME.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH FOR SHRA/TSRA TRENDS INTO THIS EVENING.
* MEDIUM-HIGH IN WIND DIRECTION THIS EVENING.
* MEDIUM FOR LAKE BREEZE TUESDAY.
MM/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...VFR. NNE WINDS ABOVE 10 KT.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. EAST WINDS.
SUNDAY...VFR. SOUTH-SOUTHWEST WINDS.
KMD
&&
.MARINE...
306 PM...LOW PRESSURE OVER THE SOUTHERN LAKES THIS AFTERNOON WILL
MOVE TO NEAR LAKE ONTARIO TUESDAY MORNING AS IT SLOWLY DEEPENS.
THIS LOW WILL THEN ABSORB ANOTHER LOW OVER NORTHERN QUEBEC ON
TUESDAY. THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES
BETWEEN THIS LOW AND HIGH PRESSURE OVER THE PLAINS WHICH WILL
BUILD SOUTHEAST TUESDAY INTO WEDNESDAY. NORTHERLY WINDS WILL
INCREASE TO 15-25KTS LATER TONIGHT AND CONTINUE INTO TUESDAY
EVENING...BEFORE DIMINISHING TUESDAY NIGHT INTO WEDNESDAY MORNING
AS THE HIGH APPROACHES.
LOW PRESSURE WILL MOVE ACROSS ONTARIO THURSDAY AS THE HIGH REMAINS
OVER THE OHIO VALLEY AND THIS WILL TIGHTEN GRADIENT ACROSS LAKE
MICHIGAN THURSDAY INTO THURSDAY NIGHT WITH SOUTHWEST WINDS PERHAPS
AS HIGH AS 15-25 KT WHICH WILL THEN DIMINISH LATER THURSDAY NIGHT
INTO FRIDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 7 AM
WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 4
AM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
350 PM CDT MON AUG 10 2015
.MESOSCALE DISCUSSION...
349 PM CDT
THREE LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE TO TRACK
SOUTHWARD FROM CENTRAL WISCONSIN TO NORTHERN ILLINOIS. THE FIRST
LINE...NOW EXTENDING FROM LONG POINT TO DE MOTTE...HAS LOST MUCH OF
ITS STRENGTH AS THE OUTFLOW BOUNDARY HAS OUTRUN THE MAIN LINE OF
STORMS. THIS OUTFLOW HAS SHOWN GUSTS OF 25KT AT IKK WITH SIMILAR
VALUES EXPECTED FOR THE REMAINDER OF ITS LIFE IN THE CWA. SINCE THIS
LINE HAS THE MOST UNTAPPED INSTABILITY TO WORK WITH...A FEW GIRTHY
YET SUB-SEVERE STORMS ARE POSSIBLE.
THE MIDDLE LINE OF STORM EXTENDING FROM BUFFALO TO NORTH CHICAGO IS
CURRENTLY SHOWING THE MOST UPWARD GROWTH AND OUTFLOW INTERACTIONS.
DOPPLER RADAR SHOWS NUMEROUS OUTFLOW WAVES FROM MULTIPLE PREVIOUS
STORMS. THESE INTERACTIONS CAN ACT TO CREATE LOW LEVEL WIND SHEAR
AND MAY PROMPT BRIEF FUNNEL CLOUD DEVELOPMENT. ONE CELL IN
PARTICULAR FROM CAROL STREAM HEADED SOUTH TOWARD DOWNERS GROVE HAS
SHOWN NEARLY 60 DBZ OF REFLECTIVITY ABOVE THE -20C LINE. 1 INCH HAIL
IS NOT OUT OF THE QUESTION WITH CELLS SIMILAR TO THIS OVER THE NEXT
2-3 HOURS WHILE DAYTIME HEATING IS STILL ABUNDANT. EXPECT CONTINUED
INTERACTIONS TO ALSO FUEL CELL GROWTH. IN THIS REGIME...EVEN
VERTICALLY CHALLENGED CELLS MAY SHOW SIGNS OF BRIEF ROTATION...BUT
WIDESPREAD TORNADIC ACTIVITY IS NOT ANTICIPATED.
THE THIRD/NORTHERLY LINE MARKS A COLD FRONT WHERE DEWPOINT
TEMPERATURES DROP ROUGHLY 10 DEGREES. THIS LINE HAS THE MOST
SUFFICIENT FORCING MECHANISM...BUT LITTLE IN THE WAY OF INSTABILITY.
THE FRONT WILL BE HALFWAY ACROSS THE CWA BY 23Z (MENDOTA TO
PLAINFIELD TO GARY)...AT WHICH POINT THE LOSS OF DAYTIME HEATING IS
EXPECTED TO CEASE REMAINING THUNDER CHANCES. THIS IS SUPPORTED BY
THE EXPERIMENTAL HRRR THAT SUGGESTS ISOLATED LINGERING SHOWERS
THROUGH 00Z.
MM
&&
.SHORT TERM...
237 PM CDT
THROUGH TONIGHT...
A SERIES OF SHORTWAVE TROUGHS CONTINUE TO TRACK SOUTHEAST ACROSS THE
REGION GENERATING BANDS OF SHOWERS AND THUNDERSTORMS. THE FIRST WAVE
IS CROSSING FAR SOUTHERN LAKE MICHIGAN PUSHING A BAND OF SHOWERS AND
STORMS SOUTHWARD ALONG THE I-80 CORRIDOR AT THIS TIME WITH ANOTHER
CLUSTER OUT OVER LAKE MICHIGAN. WITH THE MOVEMENT OF THE WAVE
HAVING AN EASTWARD COMPONENT THE BETTER LARGER SCALE FORCING WILL
BE SHIFTING AWAY FROM THE CURRENT BAND OF ACTIVITY ALONG I-80 SO
THIS AREA MAY START TO FADE IN COVERAGE OVER THE NEXT COUPLE HOURS.
IN ADDITION...OUTFLOW IS NOW OUTRUNNING THE CONVECTION SUPPORTING A
DOWNWARD TREND. HOWEVER...WITH AN UNSTABLE AIRMASS IN PLACE THE
OUTFLOW MAY GENERATE NEW STORMS SOUTH OF I-80 BUT THE EXITING OF THE
UPPER FORCING SUGGESTS MORE ISOLATED COVERAGE TO ANYTHING
ADDITIONAL. AREAS OF NORTHWEST INDIANA PROBABLY HAVE THE BEST CHANCE
FOR RENEWED DEVELOPMENT FROM THIS FIRST WAVE THROUGH LATE AFTERNOON.
ATTENTION TURNS TO A SECOND WAVE TRACKING ACROSS CENTRAL WISCONSIN
WHICH IS GENERATING SCATTERED CONVECTION ACROSS MUCH OF SOUTHERN
WISCONSIN. THIS ACTIVITY IS MORE DISJOINTED IN COVERAGE BUT WILL
LIKELY CONTINUE INTO NORTHERN ILLINOIS INTO LATE AFTERNOON...WITH
ADDITIONAL DEVELOPMENT ACROSS NORTHERN ILLINOIS IN THE MEANTIME.
STORM ORGANIZATION WILL LIKELY BE A BIGGER CHALLENGE NORTH OF I-80
GIVEN THE PREVIOUS ACTIVITY BUT SOME BRIEF PULSING OF UPDRAFTS MAY
PRODUCE SOME SMALL HAIL AND SOME SUB SEVERE WIND GUSTS. A SUBTLE
COOL FRONTAL BOUNDARY WILL BRING A PUSH OF DRIER AIR INTO THE AREA
EARLY THIS EVENING AS THE UPPER WAVE EXITS. THIS WILL BRING AN END
TO ANY CONVECTION. WILL KEEP A MINIMAL CHANCE FOR POPS VERY EARLY
THIS EVENING. OTHERWISE DRY WEATHER IS EXPECT TONIGHT. CANNOT RULE
OUT SOME PATCHY FOG LATE ACROSS SOUTHERN AREAS WHERE WINDS WILL BE
LIGHTEST BUT THERE MAY BE ENOUGH OF A BREEZE TO MITIGATE ANY
DEVELOPMENT. FURTHER NORTH...DECREASING DEWPOINTS AND A SLIGHT
BREEZE SHOULD FURTHER REDUCE THE CHANCE FOR FOG DEVELOPMENT.
MDB
&&
.LONG TERM...
TUESDAY THROUGH MONDAY...
306 PM...MAIN FORECAST CONCERN IS PRECIP CHANCES THURSDAY NIGHT
THRU FRIDAY NIGHT AND AGAIN SUNDAY NIGHT INTO MONDAY.
HIGH PRESSURE WILL BUILD ACROSS THE REGION TUESDAY AND TUESDAY NIGHT
AND THEN SLOWLY SAG SOUTHEAST OF THE AREA WEDNESDAY NIGHT INTO
THURSDAY. THIS WILL PROVIDE DRY WEATHER WITH NORTHEAST WINDS OFF THE
LAKE TUESDAY AND THEN A LAKE BREEZE WEDNESDAY...KEEPING AREAS NEAR
THE LAKE A FEW DEGREES COOLER BUT WITH MOSTLY SUNNY SKIES...TEMPS
INLAND SHOULD REACH AROUND 80 BOTH DAYS.
WINDS TURN SOUTHWESTERLY WEDNESDAY NIGHT AS THE LOW LEVELS BEGIN TO
WARM SOME OVERNIGHT. NOT SURE HOW LOW TEMPS WILL DROP NOW WEDNESDAY
NIGHT INTO THURSDAY MORNING WITH THIS WARMING ALOFT. STILL POSSIBLE
FOR SOME MID/UPPER 50S LOW TEMPS AWAY FROM URBAN AREAS AND PERHAPS
MOST LIKELY INTO NORTHWEST INDIANA. THURSDAY LOOKING TO BE A BREEZY
WARM DAY AS HIGHS REBOUND BACK INTO THE MID 80S.
AN UPPER LEVEL WAVE IS EXPECTED TO MOVE ACROSS THE WESTERN LAKES
REGION THURSDAY NIGHT INTO FRIDAY WHICH WILL BE THE NEXT CHANCE FOR
SHOWERS/THUNDERSTORMS. OVERALL CONFIDENCE IS SOMEWHAT LOW REGARDING
COVERAGE/TIMING BUT CHANCE POPS INTO FRIDAY EVENING LOOK REASONABLE.
WINDS WILL LIKELY TURN OFF THE LAKE POSSIBLY FRIDAY AFTERNOON BUT
ESPECIALLY ON SATURDAY.
THE UPPER RIDGE BUILDS BACK INTO THE REGION SUNDAY INTO MONDAY.
TEMPS WILL LIKELY RISE BACK INTO THE MID...PERHAPS UPPER 80S DURING
THIS TIME PERIOD WITH A STRONGER COLD FRONT MOVING SOUTH INTO THE
UPPER MIDWEST/NORTHERN LAKES REGION SUNDAY/SUNDAY NIGHT. STILL
TIMING DIFFERENCES WITH HOW FAST THIS FRONT MOVES SOUTH ACROSS THE
AREA EARLY NEXT WEEK. OUTSIDE OF ANY LAKE COOLING...APPEARS HIGHS
IN THE MID 80...PERHAPS UPPER 80S...IS ON TRACK FROM THURSDAY
UNTIL THIS FRONT ARRIVES EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* THUNDER FOR 1 HOUR AND SHRA MOVING THROUGH TERMINALS CURRENTLY.
* NORTH TO NORTHEAST WINDS GENERALLY UNDER 9KT TODAY...EXCEPT
BRIEF NORTHEAST GUSTS TO 20KT.
* LAKE BREEZE DEVELOPMENT TUESDAY AFTERNOON.
MM
//DISCUSSION...UPDATED 18Z...
LINE OF THUNDERSTORMS ALONG A NOW DEFINED BOUNDARY CONTINUES TO
SWEEP ACROSS THE CHICAGO TERMINALS EARLY THIS AFTERNOON. MAIN
CELLS APPEAR TO MISS ORD AND MDW...WITH VICINITY THUNDER COVERING
THIS FEATURE. SECOND BOUNDARY APPEARS TO ENTER THE AIRSPACE AROUND
20Z AS NOTED IN WEAK RADAR RETURNS IN CENTRAL WISCONSIN. THE
INITIAL LINE SHOULD LOWER INSTABILITY...LEAVING LESS ENERGY FOR
THE SECOND BOUNDARY TO TAP INTO. HAVE LEFT VCSH IN THE TAF WITH NO
MENTION OF THUNDER. FORECAST SOUNDINGS STILL SHOW LAPSE RATES
IN THE 8-10 C/KM RANGE WITH CONVECTIVE TEMPS OF 80F...SO THUNDER IS
NOT COMPLETELY OUT OF THE QUESTION IN THE 20-23Z TIMEFRAME.
BEHIND THE BOUNDARY...MAINLY VFR CONDITIONS ARE LIKELY FOR AN
EXTENDED PERIOD OF TIME. WHILE OUTLYING AREAS MAY SEE PATCHY AM
FOG...THE CHICAGO TERMINALS SHOULD STAY VFR. THE FOLLOWING FEW
DAYS WILL ALLOW FOR LAKE BREEZE CHANCES GENERALLY INITIALIZING IN
THE 19-22Z TIMEFRAME.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH FOR SHRA AND MEDIUM HIGH FOR THUNDER.
* HIGH FOR WINDS TODAY.
* MEDIUM FOR LAKE BREEZE TUESDAY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...VFR. NNE WINDS ABOVE 10 KT.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. EAST WINDS.
SUNDAY...VFR. SOUTH-SOUTHWEST WINDS.
KMD
&&
.MARINE...
306 PM...LOW PRESSURE OVER THE SOUTHERN LAKES THIS AFTERNOON WILL
MOVE TO NEAR LAKE ONTARIO TUESDAY MORNING AS IT SLOWLY DEEPENS.
THIS LOW WILL THEN ABSORB ANOTHER LOW OVER NORTHERN QUEBEC ON
TUESDAY. THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES
BETWEEN THIS LOW AND HIGH PRESSURE OVER THE PLAINS WHICH WILL
BUILD SOUTHEAST TUESDAY INTO WEDNESDAY. NORTHERLY WINDS WILL
INCREASE TO 15-25KTS LATER TONIGHT AND CONTINUE INTO TUESDAY
EVENING...BEFORE DIMINISHING TUESDAY NIGHT INTO WEDNESDAY MORNING
AS THE HIGH APPROACHES.
LOW PRESSURE WILL MOVE ACROSS ONTARIO THURSDAY AS THE HIGH REMAINS
OVER THE OHIO VALLEY AND THIS WILL TIGHTEN GRADIENT ACROSS LAKE
MICHIGAN THURSDAY INTO THURSDAY NIGHT WITH SOUTHWEST WINDS PERHAPS
AS HIGH AS 15-25 KT WHICH WILL THEN DIMINISH LATER THURSDAY NIGHT
INTO FRIDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 7 AM
WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 4
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
255 PM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 254 PM CDT MON AUG 10 2015
ISOLATED SHOWERS AND THUNDERSTORMS WILL OCCUR UNTIL SUNSET OVER
CENTRAL AND SOUTHEAST IL. A FRONTAL BOUNDARY ALONG A PARIS TO
CHARLESTON TO EFFINGHAM TO VANDALIA LINE WILL PUSH THROUGH SE IL
LATE THIS AFTERNOON GIVING ISOLATED CONVECTION THERE. MEANWHILE AN
UPPER LEVEL SHORT WAVE OVER SOUTHERN LAKE MI INTO NORTHERN IL WILL
PUSH INTO CENTRAL IL BY 00Z WITH THE BRUNT OF ITS LIFT PASSING NE OF
CENTRAL IL OVER NORTHERN HALF OF INDIANA INTO SOUTHERN LOWER MI.
SCATTERED SHOWERS AND THUNDERSTORMS OVER NORTHERN IL JUST NORTH OF
CWA WILL PUSH SE INTO THE IL RIVER VALLEY LATE THIS AFTERNOON AND
TOWARD I-72 EARLY THIS EVENING. CAPES PEAK FROM 1500-3000 J/KG THIS
AFTERNOON WITH BULK SHEAR OF 20-40 KTS. THIS COULD SUPPORT A FEW
STRONG THUNDERSTORMS FROM I-74 NE AND FROM I-70 SE UNTIL 00Z/7 PM.
WEAK HIGH PRESSURE BUILD ACROSS THE MIDWEST INTO TONIGHT AND NW
WINDS TO BRING IN SOMEWHAT COOLER AND LESS HUMID AIR. LOWS OVERNIGHT
IN MID 60S WITH SOME UPPER 60S SOUTH OF I-70. PATCHY SHALLOW GROUND
FOG POSSIBLE LATE TONIGHT SE OF THE IL RIVER AND MORE WIDESPREAD IN
AREAS EAST AND SOUTH OF CENTRAL IL.
&&
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 254 PM CDT MON AUG 10 2015
SURFACE HIGH PRESSURE WILL BUILD INTO THE MIDWEST THROUGH MIDWEEK
WHILE NORTHWEST FLOW AFFECTS THE AREA BETWEEN UPPER LEVEL RIDGING
OVER THE ROCKIES/WESTERN PLAINS AND TROUGHING OVER THE EAST COAST.
RELATIVELY MILD TEMPERATURES AND LESS HUMIDITY WILL BE ASSOCIATED
WITH THIS PATTERN AND HIGHS ARE EXPECTED IN THE LOW TO MID 80S
TUESDAY THROUGH THURSDAY...WITH DEWPOINTS IN THE 60S. LOWS FROM
AROUND 60 TO 65 EXPECTED EACH NIGHT.
A WEAKENING COLD FRONT CONTINUES IN MODEL FORECASTS FOR FRIDAY. THE
BULK OF MODEL GUIDANCE DROPS THE FRONTAL BOUNDARY FROM THE GREAT
LAKES REGION SOUTHWARD...PRIMARILY THROUGH AREAS EAST OF ILLINOIS.
THE BOUNDARY COULD BE A FOCUS FOR SHOWERS AND THUNDERSTORMS IN
NORTHERN AND EAST CENTRAL IL FRIDAY AND FRIDAY NIGHT. VERY LITTLE
COLD AIR IS EXPECTED TO PUSH INTO CENTRAL IL...AND TEMPERATURES
SHOULD CONTINUE A SLOW CLIMB INTO THE MID AND UPPER 80S FRIDAY
THROUGH MONDAY. ANOTHER COLD FRONT COULD POTENTIALLY AFFECT THE AREA
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1258 PM CDT MON AUG 10 2015
A FRONTAL BOUNDARY SOUTH OF I-72 WILL PUSH INTO SOUTHEAST IL
DURING THIS AFTERNOON WITH NW WIND 5-10 KTS BEHIND THIS BOUNDARY
OVER CENTRAL IL AIRPORTS. ISOLATED CONVECTION STARTED TO
DEVELOPING ALONG THIS BOUNDARY WHICH HAS MISSED THE CENTRAL IL
TAF SITES. AN UPPER LEVEL TROF OVER SE WI AND NW IL WILL MOVE
INTO THE IL RIVER VALLEY LATE THIS AFTERNOON. SCATTERED CONVECTION
OVER NORTHERN IL NORTH OF I-80 WILL SPREAD SE AT 30 MPH TOWARD PIA
BY 20Z AND BMI AND POSSIBLY CMI BETWEEN 21-22Z AS IT BECOMES MORE
ISOLATED. SO CARRIED VCTS/VCSH TO ADDRESS THIS CHANCE WITH MVFR
CEILINGS POSSIBLE AT TIMES THIS AFTERNOON. ISOLATED CONVECTION
SHOULD END BY SUNSET LEAVING MOSTLY CLEAR SKIES AND LIGHT NW WINDS
TONIGHT. HAVE 3-5 MILES FOG FROM 09Z-14Z WHILE MORE WIDESPREAD
AND DENSER FOG TO OCCUR NE OF CMI OVER INDIANA AND NE IL AND SW
OF SPI OVER SW IL INTO MO AND WESTERN KY PER HRRR MODEL VSBY
FORECAST THRU 07Z. WINDS TO BE NORTH 5-9 KTS AFTER 14Z TUE
MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...ONTON
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
101 PM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT MON AUG 10 2015
UPDATED THE FORECAST DURING MID MORNING WITH DENSE FOG ADVISORY
ENDING AT 9 AM ACROSS NORTHERN HALF OF CWA. WILL ISSUE ANOTHER
UPDATE LATE THIS MORNING TO REMOVE MENTION OF PATCHY FOG THIS
MORNING. OTHERWISE REST OF FORECAST LOOKS ON TRACK THIS AFTERNOON.
HAVE 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS
WARM AND HUMID CONDITIONS PREVAIL WITH DEWPOINTS OF 70-75F AND
SEASONABLE HIGHS IN THE LOW TO MID 80S. A WEAK FRONTAL BOUNDARY
JUST SE OF A RANTOUL TO DECATUR TO TAYLORVILLE LINE WILL PUSH SE
ACROSS SOUTHEAST IL DURING THIS AFTERNOON GIVING ISOLATED SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF IT WHERE UNSTABLE AIRMASS
WITH CAPES OF 1500-2500 J/KG. MEANWHILE A SHORT WAVE TROF OVER SE
WI INTO IA WILL SHIFT SE INTO THE IL RIVER VALLEY LATER THIS
AFTEROON GIVING A CHANCE OF SHOWERS/THUNDESTORMS THERE AS WELL.
SPC KEEPS MARGINAL RISK OF SEVERE STORMS SE OF CWA THIS AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VSBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE
PAST HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL
DENSE FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY
DENSE OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1258 PM CDT MON AUG 10 2015
A FRONTAL BOUNDARY SOUTH OF I-72 WILL PUSH INTO SOUTHEAST IL
DURING THIS AFTERNOON WITH NW WIND 5-10 KTS BEHIND THIS BOUNDARY
OVER CENTRAL IL AIRPORTS. ISOLATED CONVECTION STARTED TO
DEVELOPING ALONG THIS BOUNDARY WHICH HAS MISSED THE CENTRAL IL
TAF SITES. AN UPPER LEVEL TROF OVER SE WI AND NW IL WILL MOVE
INTO THE IL RIVER VALLEY LATE THIS AFTERNOON. SCATTERED CONVECTION
OVER NORTHERN IL NORTH OF I-80 WILL SPREAD SE AT 30 MPH TOWARD PIA
BY 20Z AND BMI AND POSSIBLY CMI BETWEEN 21-22Z AS IT BECOMES MORE
ISOLATED. SO CARRIED VCTS/VCSH TO ADDRESS THIS CHANCE WITH MVFR
CEILINGS POSSIBLE AT TIMES THIS AFTERNOON. ISOLATED CONVECTION
SHOULD END BY SUNSET LEAVING MOSTLY CLEAR SKIES AND LIGHT NW WINDS
TONIGHT. HAVE 3-5 MILES FOG FROM 09Z-14Z WHILE MORE WIDESPREAD
AND DENSER FOG TO OCCUR NE OF CMI OVER INDIANA AND NE IL AND SW
OF SPI OVER SW IL INTO MO AND WESTERN KY PER HRRR MODEL VSBY
FORECAST THRU 07Z. WINDS TO BE NORTH 5-9 KTS AFTER 14Z TUE
MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...07
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
338 PM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 335 PM EDT MON AUG 10 2015
A COUPLE OF UPPER LEVEL DISTURBANCES WILL CONTINUE TO PRODUCE
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING. DRIER AIR WILL
FILTER INTO THE AREA LATER THIS EVENING INTO THE OVERNIGHT BEHIND
THIS SYSTEM. DRY WEATHER IS THEN EXPECTED THROUGH MID WEEK. LOW
TEMPERATURES TONIGHT WILL DROP INTO THE LOWER TO MID 60S. HIGH
TEMPERATURES ON TUESDAY WILL REACH INTO THE MID TO UPPER 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
LEAD SHORT WAVE WHICH TRACKED ACROSS THE AREA EARLIER TODAY ALLOWED
FOR INITIAL WEAK LAKE ENHANCED SURFACE TROUGH TO SERVE AS FOCUSING
MECHANISM FOR SCATTERED SHOWERS/ISOLATED STORMS. OVER PAST
HOUR...STARTING TO SEE UPSWING IN CONVECTIVE COVERAGE ALONG THIS
BOUNDARY AS A STRONGER UPSTREAM VORT MAX ACROSS NORTHERN ILLINOIS
CONTINUES TO APPROACH THE AREA. A SECONDARY AREA OF
SCATTERED/NUMEROUS SHOWERS/STORMS HAS DEVELOPED ACROSS FAR
SOUTHERN/AND MAINLY SOUTH OF FORECAST AREA ACROSS CENTRAL INDIANA.
THIS AREA APPEARS BE TIED MORE CLOSELY TO ENHANCED LOW LEVEL THETAE
ADVECTION...WHICH ALSO IS COLOCATED WITH MORE PRONOUNCED INSTABILITY
AXIS WITH LATEST RUC ANALYSIS DEPICTING 100 HPA MLCAPES ON THE ORDER
OF 1000-1500 J/KG. MODEST DEEP LAYER SHEAR AND AND WEAK TO MODERATE
INSTABILITY WILL CONTINUE TO POSE SOME THREAT OF ISOLD STRONG STORMS
WITH GUSTY WINDS AS THE MAIN THREAT. WHILE BRIEF VERY HEAVY RAINFALL
IS POSSIBLE...PROPAGATION VECTORS ARE SLIGHTLY MORE PROGRESSIVE THIS
AFTERNOON IN COMPARISON TO LAST EVENING AND CURRENT THINKING IS THAT
WHILE LOCALIZED PONDING OF WATER/MINOR FLOODING IS POSSIBLE WITH THE
STRONGER STORMS...FLASH FLOODING CONCERNS SHOULD BE MINIMAL.
PRIMARY INSTABILITY AXIS SHOULD BEGIN TO ADVECT ACROSS FAR EASTERN
PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON...BUT WEAK
INSTABILITY WILL REMAIN ACROSS ENTIRE FORECAST AREA AS
AFOREMENTIONED NORTHERN ILLINOIS VORT MAX ALLOWS FOR EROSION OF
RELATIVELY 800-700 HPA LAYER NOTED PER EARLIER AMDAR REGIONAL
SOUNDINGS. THIS SHOULD ALLOW FOR ENOUGH LINGERING INSTABILITY WITH
STRONGER ILLINOIS VORT MAX TO KEEP SOME CHANCE OF ISOLD-SCT
CONVECTION ACROSS THE AREA EARLY THIS EVENING. QUIET CONDITIONS
EXPECTED LATER THIS EVENING INTO THE OVERNIGHT AS SECONDARY SFC
TROUGH USHERS IN COOLER AND DRIER LOW LEVEL AIR. QUIET WEATHER
EXPECTED FOR TUESDAY WITH PERSISTENT MID LEVEL SUBSIDENCE...ALTHOUGH
THE NEXT IN SERIES OF UPPER LEVEL SHORT WAVES IS EXPECTED TO DIG
ACROSS THE GREAT LAKES EARLY TUESDAY...WHICH COULD PROMOTE AN
ISOLATED SHOWER ACROSS SOUTHEAST LOWER MICHIGAN. GIVEN VERY MARGINAL
MOISTURE PROFILES...WILL OMIT FROM FORECAST WITH JUST SLIGHTLY MORE
CONCENTRATED DIURNAL CU ACROSS THE FAR NORTHEAST. DESPITE LOW LEVEL
CAA...GOOD DEAL OF INSOLATION MOST AREAS SHOULD ALLOW FOR HIGHS IN
THE MID TO UPPER 70S.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
HIGH PRESSURE MOVING OUT OF CANADA WILL BRING COOL...DRY
WEATHER FOR THE FIRST PORTION OF THE LONG TERM PERIOD. AS THE
LONGWAVE PATTERN BECOMES MORE ZONAL INTO THE WEEKEND...
TEMPERATURES WILL WARM AND A FEW FRONTAL BOUNDARIES WILL DROP
SOUTHWARD INTO THE GREAT LAKES REGION WITH SHOWERS AND
THUNDERSTORMS POSSIBLE. THE FIRST OF THESE FRONTS WILL DROP
THROUGH ON FRIDAY. A FEW STORMS ARE POSSIBLE ALONG THIS
FRONT...BUT LIMITED INSTABILITY SHOULD LIMIT WIDESPREAD
DEVELOPMENT. THIS FIRST FRONT WILL SETTLE SOUTH OF THE AREA OVER
THE WEEKEND WHICH SHOULD KEEP OUR AREA DRY.
BETTER SHOWERS AND STORM CHANCES RETURN BY THE EARLY PART OF NEXT
WEEK AS MODEL CONSENSUS STALLS A FRONTAL BOUNDARY ACROSS THE
SOUTHERN GREAT LAKES. DEWPOINTS IN THE UPPER 60S TO LOW 70S COUPLED
WITH DAYTIME HEATING SHOULD PROVIDE WEAK TO MODERATE INSTABILITY
EACH DAY...DEPENDING ON THE DEGREE OF HEATING. AT THIS TIME...MID
LEVEL LAPSE RATES AND DEEP LAYER SHEAR LOOK LACKLUSTER WHICH SHOULD
PRECLUDE ANY ORGANIZED SEVERE WEATHER THREAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 138 PM EDT MON AUG 10 2015
LAKE ENHANCED SURFACE TROUGH AXIS HAS BEEN FOCAL POINT FOR
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS NORTH CENTRAL
INDIANA. THE IMMEDIATE NEAR TERM FOCUS IN THE NEXT 2 HOURS FOR
THIS ACTIVITY SHOULD REMAIN SOUTHEAST OF KSBN...AND AFFECT MAINLY
KFWA BETWEEN 19Z-22Z. THIS SURFACE TROUGH DOES MARK A PARTICULARLY
PRONOUNCED GRADIENT IN TERMS OF MOISTURE...AND ADDITIONAL
SHOWERS/STORMS HAVE DEVELOPED ACROSS NORTHEAST ILLINOIS IN CLOSER
PROXIMITY TO STRONGER UPPER VORT MAX. THUS...STILL EXPECTING
SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM TO AFFECT KSBN IN THE
20Z-22Z TIMEFRAME. WITH INSTABILITY SOMEWHAT ON THE MARGINAL SIDE
AND EXPECTED TO BE MORE PRONOUNCED AT KFWA...WILL LIMIT THUNDER
MENTION TO VCTS AT KFWA. SHOWERS/STORMS SHOULD DIMINISH AFTER 23Z
WITH DRIER AIR ADVECTING INTO NORTHERN INDIANA AND QUIET AVIATION
WEATHER CONDITIONS THROUGH THE REMAINDER OF THE PERIOD. NORTHWEST
WINDS SHOULD INCREASE IN GUSTINESS INTO THE 15 TO 20 KNOT RANGE
FOR TUESDAY AFTERNOON.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...BENTLEY
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
325 PM CDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 321 PM CDT MON AUG 10 2015
Light northeasterly surface winds prevailed across western and
central kansas this afternoon. Regional WSR88D as still showing 30
to 40 dbz reflectivity returns across the TX panhandles into
northeast oklahoma associated with the low to mid level baroclinic
zone that since has shifted south. Meanwhile a few surface based
storms have developed in south central and southeast colorado.
widespread 1.3 to 1.5 precipitable water values covered the
forecast area, with the greatest amounts in the south.
&&
.SHORT TERM...(THIS EVENING THROUGH Tuesday)
ISSUED AT 321 PM CDT MON AUG 10 2015
The latest arw and HRRR models were the most aggressive models
with respect to developing convection this afternoon. The 4 km nam
and the nmm were not as aggressive. However the nmm and 4 km HRRR
were also more aggressive with thunderstorms. The severe threat
will be minimal today and tonight with any storms that develop as
continued amplification the the upper ridge weakened the shear
profiles. However very heavy rainfall from efficient warm rain
processes will still be likely for the next day or so, but
steering flow will be weak or non existent. based on the HRRR,
thunderstorm coverage could become scattered by late in the
afternoon. additionally. thunderstorms development across
southeast colorado could spread into far southwest kansas later
this evening aided by weak vorticity advection embedded in the
northwest flow in the models.
.LONG TERM...(Tuesday NIGHT THROUGH Monday)
ISSUED AT 321 PM CDT MON AUG 10 2015
Beyond the short term, increasingly less humid conditions will
develop across central and much of western kansas as surface high
pressure from the northern plains begins to have greater
influence. The general low level moisture transport signal will
remain firmly anchored across the the western counties where the
main if any thunderstorms chances will be located, and the low
level jet may be the best mechanism for get a few thunderstorms
going. Generally high temperatures are forecast around 5 degrees
below climatology through the extended. Lowered dew points should
translate into overnight lows of a few degrees lower as well on
average.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Tuesday AFTERNOON)
ISSUED AT 1245 PM CDT MON AUG 10 2015
Light northeasterly upslope surface winds will continue through
the day, as a surface high pressure center over the northern
plains shifts to the southeast with time. The ARW and HRRR convective
allowing models indicate potential for convective redevelopment ,
but opposed to the less aggressive runs of the NMM and 4km NAM.
Additionally with surface convergence and upslope flow, and an
impulse aloft moving out of new mexico, higher probability for
storms exists over the far southeast kansas counties later this
evening. in either case, there is not enough confidence at this
time to include either tempo groups of prevailing convective
conditions at gck, much less ddc or hys.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 86 66 89 / 30 30 30 30
GCK 66 85 65 89 / 30 40 40 20
EHA 66 82 66 90 / 60 50 30 20
LBL 68 85 67 89 / 50 40 30 20
HYS 64 86 66 88 / 10 20 30 20
P28 70 86 68 88 / 10 10 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1246 PM CDT MON AUG 10 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT MON AUG 10 2015
A shortwave trough progressing across the northern plains has
pushed a cold front through western Kansas early this morning. A
few elevated showers and thunderstorms had developed and these
are expected to dissipate later this morning. A few thunderstorms
may redevelop this afternoon with daytime heating given the very
moist airmass north of the front, deep subtropical moisture at mid
levels and resultant weak capping. An organized cluster of
thunderstorms will probably develop just south and southwest of
Kansas along the frontal boundary this evening and tonight.
However, some elevated shower and thunderstorm activity is still
expected across far southwest Kansas tonight. Highs today will be
in the upper 80s to lower 90s.
.LONG TERM...(Tuesday THROUGH Sunday)
ISSUED AT 259 AM CDT MON AUG 10 2015
A cooler, post frontal regime can be expected this week with highs
mainly in the 80s through Thursday. However the airmass north of
the front will still be moist. Nocturnal showers and thunderstorms
are possible Tuesday night along and west of a line from Hays to
Dodge City given mid level warm advection. This precipitation will
probably be a little father east by Wednesday night, possibly all
the way into central Kansas. However, it does not appear as
though these will be organized heavy rains events. Drying and a
slight warming trend can be expected by the weekend as the mid to
upper level flow becomes more meridional as opposed to a more
favorable northwesterly direction, with highs warming into the
lower 90s. The next cold front may arrive by late Saturday night
or Sunday with small chances for thunderstorms.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Tuesday AFTERNOON)
ISSUED AT 1245 PM CDT MON AUG 10 2015
light northeasterly upslope surface winds will continue through the
day, as a surface high pressure center over the northern plains
shifts to the southeast with time. the arw and HRRR convective
allowing models indicate potential for convective redevelopment ,
but opposed to the less aggressive runs of the nmm and 4 km NAM.
additionally with surface convergence and upslope flow, and an
impulse aloft moving out of new mexico, higher probability for
storms exists over the far southeast kansas counties. in either
case, there is not enough confidence at this time to include
either tempo groups of prevailing convective conditions at gck,
much less ddc or hys.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 92 66 84 66 / 30 20 30 30
GCK 90 66 82 65 / 30 30 40 30
EHA 89 66 81 66 / 40 70 50 30
LBL 91 68 84 67 / 30 60 40 30
HYS 89 64 85 66 / 10 10 20 30
P28 92 70 87 68 / 60 10 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS JACKSON KY
653 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
350 PM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
301 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 145 PM EDT MON AUG 10 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE CURRENT POP PATTERN
WITH SOME ADJUSTMENTS BASED ON THE LATEST HRRR INTO THE EVENING.
ALSO FINE TUNED THE T/TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1120 AM EDT MON AUG 10 2015
14Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE CROSSING
THROUGH THE OHIO VALLEY NORTH OF KENTUCKY. A TRAILING COLD FRONT
ASSOCIATED WITH THIS IS APPROACHING THE REGION. HOWEVER...AHEAD OF
THIS BOUNDARY...AMPLE MOISTURE IS POOLING THROUGH EASTERN
KENTUCKY WITH DEWPOINTS PREDOMINATELY IN THE LOWER 70S. MORNING
BREAKS IN THE CLOUD COVER WILL HELP TO BUILD INSTABILITY THROUGH
THE CWA AS TEMPERATURES ARE CURRENTLY IN THE UPPER 70S AND LOWER
80S ON THEIR WAY TO THE MID AND UPPER 80S. THE QUESTION IS WHETHER
THE DEBRIS CLOUDS FROM THE EARLIER CONVECTION TO THE WEST WILL BE
ENOUGH TO INHIBIT THE DEVELOPMENT OF WIDESPREAD AND ORGANIZED
STORMS THROUGH THE AREA LATER THIS AFTERNOON. ALREADY A GROUP OF
SHOWERS AND DEVELOPING STORMS ARE TRACKING INTO THE CUMBERLAND
VALLEY. EXPECT THESE TO SPREAD INTO THE EARLY AFTERNOON WITH
ADDITIONAL POCKETS OF CONVECTION EXPANDING TO THE NORTH AND EAST.
THE LATEST HRRR MODEL AGREES WITH THIS SCENARIO WITH PEAK
CONVECTIVE ACTIVITY TAKING PLACE OVER THE JKL CWA BETWEEN 19 AND
23Z. HAVE UPDATED THE GRIDS WITH THIS IN MIND AS WELL AS INFUSED
THE LATEST SHORTBLEND GUIDANCE INTO THE T AND TD GRIDS. THOSE
LATER ONES WERE UPDATED TO BETTER REFLECT THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS WITH A
FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 654 AM EDT MON AUG 10 2015
WSR-88D CONTINUES TO INDICATE SOME ISOLATED SHOWERS MOVING
SOUTHEAST ACROSS PORTIONS OF EASTERN KY. EXPECT THIS MORNING
SHOWER ACTIVITY TO REMAIN LIGHT. THE HEAVIER STORMS REMAINED SOUTH
AND WEST OF THE REGION...AS MCS DIVED SOUTH TOWARD THE MORE
UNSTABLE ENVIRONMENT WHERE UPPER 70S TO LOW 80 DEWPOINTS WERE
REPORTED. STILL LOOKING AT INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS AS WE MOVE INTO THE AFTERNOON HOURS AHEAD OF A
APPROACHING COLD FRONT. SOME MINOR UPDATES TO POPS AND THEN
UPDATES TO TEMPS/DEWS/WINDS TO MATCH CURRENT CONDITIONS/TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
OVERALL MODELS REMAIN IN GOOD AGREEMENT WITH OVERARCHING SYNOPTIC
PATTERN WITH TROUGHING CONTINUE TO DEEPEN IN THE EASTERN CONUS
THROUGH THE PERIOD. THIS MORNING WE ARE BEING MET WITH A FEW
SHOWERS SPREADING SE ACROSS PORTIONS OF EASTERN KY SEEN ON WSR-
88D. THIS HAS BEEN BROUGHT ON BY UPPER LEVEL WAVE AND INCREASING
LOW LVL JET ACROSS THE OHIO/TN VALLEYS. THESE ARE DEVELOPING AHEAD
OF AN APPROACHING SURFACE LOW PRESSURE AND COLD FRONT ACROSS THE
MIDWEST THIS MORNING. WHILE WE DO HAVE SHOWERS AND PERHAPS A
ISOLATED THUNDERSTORM THIS MORNING...BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL EXIST AS WE MOVE INTO THE AFTERNOON AHEAD OF
THE COLD FRONT.
THE QUESTION IS HOW MUCH DOES ON GOING ACTIVITY AND CLOUD COVER
PLAY ON THE OVERALL DESTABILIZATION...RIGHT NOW THIS LOOKS TO
HAVE SOME AFFECTS BUT INCREASING LOW LEVEL JET AND SOME INSULATION
LOOK TO BE ENOUGH TO FIRE OF STORMS THIS AFTERNOON. THIS LOOKS
REASONABLE WITH CA MODELS SHOWING GOOD AGREEMENT OF BEST ACTIVITY
GENERALLY AFTER 18Z. WHILE SOME OF THESE STORMS COULD BE
STRONG...THINKING OVERALL SEVERE THREAT REMAINS LOW WITH SHEAR
BEING MARGINAL AT BEST. THAT SAID MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUST...AND THIS LINES UP WELL WITH SPC THINKING AND
OVERALL BROAD MARGINAL RISK. AFTER THIS SHOWER AND STORM ACTIVITY
WILL WAIN IN THE EVENING AND OVERNIGHT HOURS AS FRONT SLOWLY MOVES
EAST ACROSS THE REGION. MAINTAIN SOME INSTABILITY SHOWERS MAINLY
IN THE FAR EAST THROUGH THE DAY ON TUESDAY. OTHERWISE SOME SPOTS
ARE EXPECTED TO BEGIN THE DRYING OUT PROCESS IN THE WAKE OF THE
COLD FRONT...AS WE TRANSITION TO W/NW FLOW. THE OTHER ISSUE IS HOW
MUCH IF ANY FOG WILL BE SEEN EARLY TUESDAY GIVEN CLOUD COVER...SO
RIGHT NOW LEFT OUT OF THE FORECAST GIVEN LOWER CONFIDENCE. THAT
SAID VALLEYS AND AREAS THAT RECEIVED RAIN WILL HAVE THE BEST
CHANCES OF SEEING REASONABLE PRODUCTION.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
215 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 145 PM EDT MON AUG 10 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE CURRENT POP PATTERN
WITH SOME ADJUSTMENTS BASED ON THE LATEST HRRR INTO THE EVENING.
ALSO FINE TUNED THE T/TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1120 AM EDT MON AUG 10 2015
14Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE CROSSING
THROUGH THE OHIO VALLEY NORTH OF KENTUCKY. A TRAILING COLD FRONT
ASSOCIATED WITH THIS IS APPROACHING THE REGION. HOWEVER...AHEAD OF
THIS BOUNDARY...AMPLE MOISTURE IS POOLING THROUGH EASTERN
KENTUCKY WITH DEWPOINTS PREDOMINATELY IN THE LOWER 70S. MORNING
BREAKS IN THE CLOUD COVER WILL HELP TO BUILD INSTABILITY THROUGH
THE CWA AS TEMPERATURES ARE CURRENTLY IN THE UPPER 70S AND LOWER
80S ON THEIR WAY TO THE MID AND UPPER 80S. THE QUESTION IS WHETHER
THE DEBRIS CLOUDS FROM THE EARLIER CONVECTION TO THE WEST WILL BE
ENOUGH TO INHIBIT THE DEVELOPMENT OF WIDESPREAD AND ORGANIZED
STORMS THROUGH THE AREA LATER THIS AFTERNOON. ALREADY A GROUP OF
SHOWERS AND DEVELOPING STORMS ARE TRACKING INTO THE CUMBERLAND
VALLEY. EXPECT THESE TO SPREAD INTO THE EARLY AFTERNOON WITH
ADDITIONAL POCKETS OF CONVECTION EXPANDING TO THE NORTH AND EAST.
THE LATEST HRRR MODEL AGREES WITH THIS SCENARIO WITH PEAK
CONVECTIVE ACTIVITY TAKING PLACE OVER THE JKL CWA BETWEEN 19 AND
23Z. HAVE UPDATED THE GRIDS WITH THIS IN MIND AS WELL AS INFUSED
THE LATEST SHORTBLEND GUIDANCE INTO THE T AND TD GRIDS. THOSE
LATER ONES WERE UPDATED TO BETTER REFLECT THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS WITH A
FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 654 AM EDT MON AUG 10 2015
WSR-88D CONTINUES TO INDICATE SOME ISOLATED SHOWERS MOVING
SOUTHEAST ACROSS PORTIONS OF EASTERN KY. EXPECT THIS MORNING
SHOWER ACTIVITY TO REMAIN LIGHT. THE HEAVIER STORMS REMAINED SOUTH
AND WEST OF THE REGION...AS MCS DIVED SOUTH TOWARD THE MORE
UNSTABLE ENVIRONMENT WHERE UPPER 70S TO LOW 80 DEWPOINTS WERE
REPORTED. STILL LOOKING AT INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS AS WE MOVE INTO THE AFTERNOON HOURS AHEAD OF A
APPROACHING COLD FRONT. SOME MINOR UPDATES TO POPS AND THEN
UPDATES TO TEMPS/DEWS/WINDS TO MATCH CURRENT CONDITIONS/TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
OVERALL MODELS REMAIN IN GOOD AGREEMENT WITH OVERARCHING SYNOPTIC
PATTERN WITH TROUGHING CONTINUE TO DEEPEN IN THE EASTERN CONUS
THROUGH THE PERIOD. THIS MORNING WE ARE BEING MET WITH A FEW
SHOWERS SPREADING SE ACROSS PORTIONS OF EASTERN KY SEEN ON WSR-
88D. THIS HAS BEEN BROUGHT ON BY UPPER LEVEL WAVE AND INCREASING
LOW LVL JET ACROSS THE OHIO/TN VALLEYS. THESE ARE DEVELOPING AHEAD
OF AN APPROACHING SURFACE LOW PRESSURE AND COLD FRONT ACROSS THE
MIDWEST THIS MORNING. WHILE WE DO HAVE SHOWERS AND PERHAPS A
ISOLATED THUNDERSTORM THIS MORNING...BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL EXIST AS WE MOVE INTO THE AFTERNOON AHEAD OF
THE COLD FRONT.
THE QUESTION IS HOW MUCH DOES ON GOING ACTIVITY AND CLOUD COVER
PLAY ON THE OVERALL DESTABILIZATION...RIGHT NOW THIS LOOKS TO
HAVE SOME AFFECTS BUT INCREASING LOW LEVEL JET AND SOME INSULATION
LOOK TO BE ENOUGH TO FIRE OF STORMS THIS AFTERNOON. THIS LOOKS
REASONABLE WITH CA MODELS SHOWING GOOD AGREEMENT OF BEST ACTIVITY
GENERALLY AFTER 18Z. WHILE SOME OF THESE STORMS COULD BE
STRONG...THINKING OVERALL SEVERE THREAT REMAINS LOW WITH SHEAR
BEING MARGINAL AT BEST. THAT SAID MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUST...AND THIS LINES UP WELL WITH SPC THINKING AND
OVERALL BROAD MARGINAL RISK. AFTER THIS SHOWER AND STORM ACTIVITY
WILL WAIN IN THE EVENING AND OVERNIGHT HOURS AS FRONT SLOWLY MOVES
EAST ACROSS THE REGION. MAINTAIN SOME INSTABILITY SHOWERS MAINLY
IN THE FAR EAST THROUGH THE DAY ON TUESDAY. OTHERWISE SOME SPOTS
ARE EXPECTED TO BEGIN THE DRYING OUT PROCESS IN THE WAKE OF THE
COLD FRONT...AS WE TRANSITION TO W/NW FLOW. THE OTHER ISSUE IS HOW
MUCH IF ANY FOG WILL BE SEEN EARLY TUESDAY GIVEN CLOUD COVER...SO
RIGHT NOW LEFT OUT OF THE FORECAST GIVEN LOWER CONFIDENCE. THAT
SAID VALLEYS AND AREAS THAT RECEIVED RAIN WILL HAVE THE BEST
CHANCES OF SEEING REASONABLE PRODUCTION.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
QUIET LONG TERM PERIOD IN STORE AS AN EXPANSIVE UPPER LEVEL RIDGE
OVER THE FOUR CORNERS REGION EXTENDS NORTHWARD INTO CENTRAL
CANADA. WHILE A TROUGH REMAINS IN PLACE OVER THE EASTERN CONUS...THE
HIGH AMPLITUDE RIDGE TO OUR WEST PLACES THE SOURCE REGION FOR OUR
AIRMASS ALOFT OVER THE PRAIRIE PROVINCES OF CANADA...SO NOT MUCH
OPPORTUNITY FOR MOISTURE RETURN. MODELS INDICATE A PIECE OF THE
UPPER TROUGH OVER THE EAST WILL RETROGRADE SOUTHWEST AND POSSIBLY
BREAK OFF INTO A WEAK CLOSED LOW OVER THE DEEP SOUTH. THIS MAY BRING
ENOUGH LOW LEVEL MOISTURE IN OFF THE ATLANTIC TO CAUSE SOME ISOLATED
DIURNAL CONVECTION OVER THE HIGHER TERRAIN OF THE SOUTHERN
APPALACHIANS AT TIMES...BUT NOT LIKELY AFFECTING OUR AREA. THE NET
RESULT SHOULD BE A DRY FORECAST WITH PLEASANT TEMPS AND HUMIDITY
MID WEEK SLOWLY MODERATING BACK TO SEASONAL NORMS BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1217 PM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE THIS MORNING TO FOCUS SHOWER COVERAGE ACROSS THE
SRN PIEDMONT...SCNTRL VA...AND SRN RICHMOND METRO AREAS THROUGH
THE REST OF THIS MORNING BEFORE SHOWERS DISSIPATE.
PREVIOUS DISCUSSION (651 AM)...RADAR TRENDS INDICATE SHOWERS
HOLDING TOGETHER BETTER THAN EXPECTED OVER AN INCREASINGLY MOIST
AIR MASS. LATEST RAP GUIDANCE DEPICTS WEAK VORT MAX OVER THE
REGION...PROVIDING SUBTLE FORCING OVER AN AREA OF ISENTROPIC
LIFT...HELPING DRIVE THE SHOWERS. THIS LIFT IS PROGGED TO SPREAD
NEWD ACROSS CENTRAL VA THRU MID MORNING. HIGH PRESSURE ALONG THE
COAST WILL BEGIN TO WIN OUT...HELPING ERODE THE SHOWERS AS THEY
SPREAD EAST OF INTERSTATE 95. MID LEVEL CLOUDS HAVE ALSO
OVERSPREAD THE AREA...RESULTING IN A MOSTLY CLOUDY SKY (PARTLY
CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND LATEST STATISTICAL
GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS THE PIEDMONT INTO
CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREVIOUS DISCUSSION (407 AM)...LATEST REGIONAL RADAR MOSAIC
DEPICTS AN AREA OF SHOWERS OVER THE ERN VA PIEDMONT EARLY THIS
MORNING...SLOWING SPREADING EWD. THIS IN ASSOCIATION WITH AN AREA
OF ISENTROPIC LIFT AND WEAKENING ENERGY ALOFT. EXPECT THIS AREA OF
SHOWERS TO DISSIPATE AS IT SPREADS EWD INTO THE LOCAL PIEDMONT
COUNTIES AS THE ENERGY ALOFT WEAKENS. HOWEVER...CLOUD COVER WILL
CONTINUE TO OVERSPREAD MUCH OF THE AREA THIS MORNING...RESULTING
IN A MOSTLY CLOUDY SKY. OTHERWISE...MID- LEVEL HEIGHT FALLS OVER
THE MID- ATLANTIC REGION HAS ALLOWED MOISTURE TO RETURN EARLY THIS
MORNING...WITH PWATS PROGGED AROUND 1.5 TO 1.8 INCHES AND
DEWPOINTS WARMING INTO THE MID 60S. AT THE SFC...HIGH PRESSURE HAS
ALIGNED ALONG THE COAST WITH A WARM FRONT LOCATED OVER THE OH/KY
VALLEYS. A COLD FRONT IS RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUE AFTERNOON...WHICH
WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR THUNDER.
STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED AROUND 1K
J/KG TUE AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE 20 TO 30
KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG WITH
LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TSCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SCA OVER THE OCEAN HAS BEEN CANCELLED AS SEAS HAVE FAILED TO STAY
UP NEAR 5 FT. OTHER SCA OVER THE BAY REMAINS IN PLACE AND MAY HAVE
TO ISSUE OTHER HEADLINES WITH THIS AFTERNOONS FORECAST PACKAGE.
PREVIOUS DISCUSSION...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTENT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTENT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD STATEMENT HAS BEEN ISSUED FOR THE BAY SIDE OF THE
LWR MD ERN SHORE THRU MIDDAY...SPECIFICALLY FOR BISHOPS HEAD WHERE
LEVELS ARE EXPECTED TO BE ABOUT A TENTH OF A FOOT BLO MINOR FLOOD
THRESHOLDS.
PREVIOUS DISCUSSION...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/BMD/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MAS/MPR
TIDES/COASTAL FLOODING...MAS/MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 PM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS CURRENTLY OVER NORTHERN ONTARIO DROP ACROSS LK SUPERIOR AND
MOVE INTO NORTHERN UPR MICHIGAN ON NORTH WINDS. CIGS SHOULD SETTLE
INTO LOW MVFR RANGE AROUND SUNRISE ON TUESDAY...WITH SOME POTENTIAL
OF IFR CIGS THROUGH TUE MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS CURRENTLY OVER NORTHERN ONTARIO DROP ACROSS LK SUPERIOR AND
MOVE INTO NORTHERN UPR MICHIGAN ON NORTH WINDS. CIGS SHOULD SETTLE
INTO LOW MVFR RANGE AROUND SUNRISE ON TUESDAY...WITH SOME POTENTIAL
OF IFR CIGS THROUGH TUE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
147 PM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS CURRENTLY OVER NORTHERN ONTARIO DROP ACROSS LK SUPERIOR AND
MOVE INTO NORTHERN UPR MICHIGAN ON NORTH WINDS. CIGS SHOULD SETTLE
INTO LOW MVFR RANGE AROUND SUNRISE ON TUESDAY...WITH SOME POTENTIAL
OF IFR CIGS THROUGH TUE MORNING. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS DULUTH MN
1252 PM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1037 AM CDT MON AUG 10 2015
UPDATED THE FORECAST THROUGH AROUND MIDNIGHT...FOCUSING ON PCPN
CHANCES AND CLOUD COVER. LATEST MODEL SOUNDINGS AND HRRR RUNS
SUGGEST THERE WILL BE SCT/BKN CUMULUS ACROSS MUCH OF THE FORECAST
AREA BY EARLY THIS AFTERNOON...SO EXPANDED CLOUD COVER. THE LATEST
NAM12/SREF/GFS/HRRR INDICATED THE NORTHERN AND SE FORECAST AREA
COULD GET ISOLATED/SCATTERED SHOWERS AND STORMS THIS AFTERNOON AND
EARLY EVENING...SO INCREASED AND EXPANDED COVERAGE OF PCPN
CHANCES.
THERE MAY BE A THREAT FOR ISOLATED STRONG STORMS IN THE COOK
COUNTY AREA OF THE ARROWHEAD THIS AFTERNOON AND EARLY EVENING. THE
NAM12 AND GFS SOUNDINGS FOR THE HIGHER TERRAIN OF THE ARROWHEAD
INDICATE MUCAPE COULD BUILD TO AROUND 1000 J/KG BY THE MIDDLE OF
THE AFTERNOON...AND THERE WOULD BE ABOUT 30 TO 35 KNOTS OF DEEP
LAYER WIND SHEAR. ALSO...FREEZING LEVELS WILL BE RELATIVELY LOW IN
THE HIGHER TERRAIN...ABOUT 9000 FT. THEREFORE...WOULD NOT BE
SURPRISED BY ISOLATED STORMS CAPABLE OF PRODUCING SMALL HAIL AND
GUSTY WINDS.
UPDATE ISSUED AT 612 AM CDT MON AUG 10 2015
PATCHY FOG WAS DOTTING THE LANDSCAPE...BUT SHOULD BURN OFF
QUICKLY. STILL ANTICIPATING SHOWERS AND STORMS WITH THE SHORTWAVE
TROF SET TO CLIP THE ARROWHEAD TODAY. LOWERED THE POPS IN NW WI A
BIT AS THE TROF STAYS A BIT FURTHER EAST.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
A SFC LOW CENTER WAS MOVING THROUGH EASTERN LAKE SUPERIOR AT 07Z
WITH ITS ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH NW WI. AREAS OF
FOG HAD FORMED ONCE AGAIN ACROSS MUCH OF THE REGION. EXPECT THE FOG
TO LINGER UNTIL 14Z. AS THE FRONT EXITS NW WI...HIGH PRESSURE BUILDS
ACROSS THE AREA. HOWEVER...AN UPPER LEVEL SHORTWAVE TROF WILL REACH
THE INTERNATIONAL BORDER BY 18Z AND PROCEED ACROSS THE ARROWHEAD AND
OVER LAKE SUPERIOR. SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN
TO AFFECT THE ARROWHEAD WWD TO NEAR CDD AT 15Z. STORMS WILL
PERCOLATE OVER THE ARROWHEAD THROUGH THE AFTERNOON WITH SOME STORM
DEVELOPMENT IN NW WI IN THE AFTERNOON.
THE SHORTWAVE TROF REACHES NORTHERN LOWER MICHIGAN BY 06Z TUESDAY.
ONE MORE IMPULSE WILL CLIP THE ARROWHEAD BEHIND THE TROF AND RESULT
IN SOME ISOLD SHOWERS FROM CKC TO GRAND PORTAGE. THIS ACTIVITY WILL
DIMINISH BY 03Z AS FORCING MOVES EAST AND SFC RIDGING COVERS THE
AREA. THE SFC RIDGING PERSISTS THROUGH TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
WARMER MID-WEEK WITH HIGHS IN THE LOW TO MID 80S ACROSS THE
REGION...THEN NOT AS HOT BUT STILL ABOVE NORMAL THROUGH SATURDAY
WITH HIGHS IN THE UPPER 70S TO LOW 80S. TWO MAIN PERIODS OF POSSIBLE
PRECIPITATION...ONE ON WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT
SWEEPS THROUGH FROM NORTHWEST TO SOUTHEAST...THEN AGAIN SATURDAY
NIGHT INTO SUNDAY AS ANOTHER COLD FRONT MOVES THROUGH. SOME
UNCERTAINTY EXISTS WITH THE TIMING OF THE LATE WEEKEND SYSTEM...BUT
IN GENERAL HAVE AN AVERAGE LEVEL OF CONFIDENCE FOR THE FORECAST.
ON THE SYNOPTIC SCALE A UPPER LEVEL RIDGE CENTERED OVER THE HIGH
PLAINS WILL GRADUALLY DRIFT WESTWARD TOWARDS THE FOUR CORNERS
THROUGH THE REST OF THE WORK WEEK...LEADING TO NORTHWEST FLOW ALOFT
LOCALLY. AHEAD OF A COLD FRONT/MID LEVEL DISTURBANCE SOUTHWESTERLY
WINDS COULD BECOME BREEZY WITH STRONG WARM AIR ADVECTION LEADING TO
PROBABLY THE WARMEST DAY OF THE FORECAST PERIOD. THERE IS A WEAK MID-
LEVEL IMPULSES IN THE NORTHWESTERLY FLOW WITH AN ASSOCIATED SFC LOW
THAT MOVES ACROSS NORTHWEST MINNESOTA INTO NORTHERN WISCONSIN LATE
WEDNESDAY INTO THURSDAY. THIS WILL BE SUPPORTED BY A 60-80 KT UPPER
LEVEL JET STREAK OVER THE UPPER MISSISSIPPI VALLEY...POSSIBLY
PEAKING UP TO 100 KTS IN STRENGTH OVER CENTRAL MINNESOTA. MODEL
SOUNDINGS DEPICT MODEST MID-LEVEL LAPSE RATES TO SUPPORT
THUNDERSTORMS...AND THE STRONG WINDS ALOFT WILL RESULT IN 35-45 KTS
DEEP LAYER SHEAR SUPPORTIVE OF POSSIBLY A FEW STRONG STORMS
OVERNIGHT INTO THURSDAY. COVERAGE OF STORMS MAY BE LIMITED GIVEN
ELEVATED NATURE AND DEPENDENCE ON UPSTREAM CONVECTION
EVOLUTION...BUT IN GENERAL THIS PERIOD LOOKS GOOD FOR
ISOLATED/SCATTERED STORMS.
FRIDAY/SATURDAY A HIGH PRESSURE OVER SOUTHERN SASKATCHEWAN/MANITOBA
DRIFTS INTO THE NORTHERN PLAINS THEN EAST ACROSS THE UPPER GREAT
LAKES RESULTING IN SUNNY SKIES AND SEASONABLE TO JUST ABOVE NORMAL
TEMPERATURES...UPPER 70S TO MID 80S. LATE SATURDAY INTO SUNDAY AN
UPPER LOW ENTERING BRITISH COLUMBIA WILL ABSORB THE ENERGY FROM AN
UPPER LOW OFF THE COAST OF THE PACIFIC NORTHWEST...DEEPENING INTO AN
UPPER LOW/TROUGH AS IT CROSSES THE CANADIAN PRAIRIE. A SECONDARY SFC
LOW/LEE TROUGH WILL DEVELOP OVER THE NORTHERN PLAINS ON SATURDAY
ALONG A COLD FRONT EXTENDING FROM NEAR THE MAIN SFC LOW IN SOUTHERN
CANADA INTO THE CENTRAL PLAINS. GUIDANCE IS IN FAIRLY REMARKABLE
AGREEMENT FOR THIS TIME RANGE...WITH ECMWF/GFS/GEM DEPICTING A
STRONG COLD FRONT IN THE EASTERN DAKOTAS/FAR WESTERN MINNESOTA
AROUND 00Z SUNDAY /SAT NIGHT/ PROGRESSING EASTWARD...THOUGH FROM
THERE MODEL SOLUTIONS DIVERGE. PRECIP CHANCES LOOK FAIRLY HIGH
REGARDLESS OF SPECIFICS. MOISTURE CONTENT WITH THIS SYSTEM MAY BE ON
THE HIGH SIDE GIVEN THE PACIFIC INFLUENCES. COOLER TEMPERATURES
EXPECTED IN WAKE OF THIS FRONT WITH HIGHS NEAR OR SLIGHTLY BELOW
SEASONABLE...IN THE LOW TO MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1238 PM CDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS WITH A SCT-BKN
CLOUD DECK AROUND 040-050 THIS AFTERNOON AND VCSH AROUND INL AND
HIB. CLOUDS SCOUR OUT THIS EVENING AND TONIGHT. MAY SEE SOME
PATCHY FOG LATE TONIGHT AND TUE MORNING. NW WINDS WILL GUST 10 TO
15 KTS TODAY AND BECOME LIGHT FROM THE NW TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 77 57 75 59 / 20 10 0 10
INL 75 52 77 56 / 20 10 0 10
BRD 79 55 80 56 / 0 0 0 0
HYR 77 55 76 53 / 20 20 0 10
ASX 76 57 73 54 / 20 20 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
113 PM CDT MON AUG 10 2015
.UPDATE:
ISSUED AT 1255 PM CDT MON AUG 10 2015
NO MAJOR CHANGES MADE. UPDATE WAS MAINLY FOR FINE TUNING POPS AND
SKY COVER FOR THE AFTN. BAND OF SHRAS AND ISLD TSTMS DVLPD LATE
THIS MRNG ALONG THE FRONT. THIS ACTIVITY WILL CONTINUE TO
PERCOLATE THRU THE AFTN AS IT SLOWLY DRIFTS SE. NE MO AND W CNTRL
IL MAY GET CLIPPED LATE THIS AFTN WITH THE TAIL END OF PRECIP
ASSOC WITH A WEAK SHORT WAVE TO OUR NE. NUDGED HIGH TEMPS UP A
A COUPLE DEGREES ACROSS NTHRN ZONES WHERE THERE ARE LESS CLOUDS
AND DOWN A COUPLE DEGREES ACROSS STHRN ZONES WHERE CONVECTIVE
DEBRIS CLOUDS ARE LINGERING.
MILLER
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 10 2015
EXPECT A FEW SHOWERS OR THUNDERSTORMS TO LINGER INTO EARLY THIS
EVENING, BUT SHOULD BE GONE BEFORE MIDNIGHT. DRIER AIR IS FORECAST
TO BUILD ACROSS THE AREA BEHIND THE FRONT TONIGHT AND TUESDAY...AND
LAST AT LEAST THROUGH THE END OF THE WEEK WITH DEWPOINT
TEMPERATURES DROPPING INTO THE 60S. A HIGH AMPLITUDE UPPER LEVEL
PATTERN LOCKS THE DRY LOW LEVEL RIDGE OVER THE MISSISSIPPI VALLEY,
SO PRECIPITATION CHANCES ARE VIRTUALLY NIL. THIS SHOULD MAKE FOR
RELATIVELY COMFORTABLE WEATHER FOR WHAT ARE TYPICALLY THE DOG-DAYS
OF SUMMER WITH HIGHS NEAR OR A FEW DEGREES BELOW NORMAL IN THE MID
TO UPPER 80S AND LOWS WELL BELOW NORMAL IN THE 60S.
CARNEY
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1255 PM CDT MON AUG 10 2015
PATCHES OF MVFR STRATUS CONTINUE TO DOT THE REGION EARLY THIS
AFTN. CLOUD HEIGHTS SHOULD CLIMB THRU THE AFTN WITH MVFR CIGS
BCMNG AROUND 21Z. A BAND OF SHRAS AND ISLD TSTMS DVLPD LATE THIS
AFTN ALONG A COLD FRONT. THIS ACTIVITY WILL CONTINUE TO PERCOLATE
THRU THE AFTN WHILE SLOWLY DRIFTING SE. VSBYS MAY BRIEFLY DIP TO
IFR UNDER THE HEAVIEST CORES. ANOTHER AREA OF PRECIP ASSOC WITH AN
UPPER LVL DISTURBANCE NEAR THE STHRN END OF LK MI MAY CLIP KUIN
LATE THIS AFTN BUT CHANCES AREA MINIMAL ATTM. PRECIP SHOULD DSSPT
AND SKIES SLOWLY CLEAR AFTER SUNSET.
SPECIFICS FOR KSTL:
BROKEN LINE OF SHRAS AND ISLD TSTMS HAS DVLPD JUST NORTH OF THE MO
RVR FROM NEAR KC TO STL. VSBYS MAY DROP TO IFR UNDER THE STRONGEST
CORES BUT WILL BE BRIEF. THIS ACTIVITY WILL DRIFT SE THRU THE
AFTN. CONVECTIVE ELEMENTS WILL BE TRANSIENT THE AFTN AND WILL
UNDOUBTABLY HAVE TO UPDATE THE TAF AS THE LINE APPROACHES THE
TERMINAL. SPOTTY MVFR CIGS WILL CONTINUE TO RAISE THRU THE AFN
BECMNG VFR IN A FEW HRS. PRECIP AND CLOUDS WILL SLOWLY DIMINISH
AFTER SUNSET WITH VFR CONDITIONS EXPECTED FOR THE REST OF THE
FCST PRD.
MILLER
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 30 20 5 0
QUINCY 85 64 84 62 / 20 20 5 0
COLUMBIA 87 67 85 63 / 30 10 5 0
JEFFERSON CITY 87 68 86 63 / 30 10 5 0
SALEM 84 70 84 63 / 30 20 10 0
FARMINGTON 84 69 84 61 / 30 20 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ELKO NV
345 PM PDT MON AUG 10 2015
.SYNOPSIS...POCKETS OF MOISTURE AND INSTABILITY WILL FUEL
THUNDERSTORM ACTIVITY. CONVECTION IS EXPECTED THIS AFTERNOON AND
EVENING OVER PORTIONS OF NORTHEASTERN NEVADA. TEMPERATURES WILL
BE NEAR NORMAL. EXPECTING ANOTHER MONSOON SURGE THIS WEEK.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY. KLRX HAS BEEN ACTIVE OVER
ELKO COUNTY THIS AFTERNOON. THE JET IS DIRECTLY OVER THE LKN
CWA...PROVIDING SUFFICIENT UPWARD VERTICAL VELOCITY OVER NE NV.
QPF-WISE...THE HRRR IS OVER DONE SOUTH OF I-80...THE NAM IS OVER
DONE IN LANDER AND EUREKA COUNTIES AND THE GFS IS UNDER DONE FOR
ALL THE EASTERN ZONES THIS AFTERNOON AND EVENING. THE MODELS
CONTINUE TO STRUGGLE WITH THE ENERGY BEING EJECTED FROM THE
PACIFIC LOW AND THE PLACEMENT OF THE MOISTURE.
TOMORROW...EXPECTING THE MONSOON SURGE TO MOVE ACROSS ARIZONA AND
INTO THE EASTERN GREAT BASIN THIS FORECAST PERIOD. THE NAM HAS THE
FETCH OF MOISTURE BISECTING CENTRAL NV AND THE GFS KEEPS IT
RESTRICTED TO THE EASTERN GREAT BASIN. THE NCEP RMOP IS ALSO
DEPICTING MODELING ISSUES AS EARLY AS 24 HRS. THE NAEFS ANOMALIES
ARE PINGING INTO A STRONG IVT...WITH A 30 YEAR RETURN INTERVAL FOR
WEDNESDAY. IF THAT VERIFIES...IT WOULD TRANSLATE INTO POTENTIAL
FLOODING ISSUES NEAR THE BORDER OF UTAH...BUT THAT SHOULD BE
TEMPERED WITH THE VAGARIES OF THE MODELS PERFORMANCES THE PAST
SEVERAL DAYS. NO SHORTAGE OF UNCERTAINTY THIS PERIOD...BUT ALSO
SOME POTENTIALLY INTERESTING WEATHER ON THE HORIZON. STAY TUNED
FOR MORE DETAILS.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT MONDAY. THE MODELS HAVE
DISAGREED ON TIMING...STRENGTH...POSITION AND JUST ABOUT EVERYTHING
ELSE FOR A WEEK...COMING A LITTLE CLOSER EACH DAY. TODAY...THEY SEEM
TO BE IN ALMOST PERFECT AGREEMENT. MODERATELY SERIOUS DISAGREEMENT
DOES NOT APPEAR UNTIL SUNDAY NIGHT.
MAJOR MODELS HAVE A SLUG OF QUASI-MONSOON MOISTURE EXITING THE
REGION WEDNESDAY NIGHT WITH SOME LEFTOVER CONVECTION IN THE EASTERN
BORDERLANDS. THIS SLIDES ON EAST AND A DRY SOUTHWEST FLOW SETS UP
FOR THE REMAINDER. THERE WILL NO DOUBT BE AN ISOLATED DRY STORM NOW
AND THEN WITH HEAT AND SOME ELEVATED MOISTURE AND HUMIDITY. BUT HAVE
KEPT POPS LOW ENOUGH AFTER THURSDAY TO ESSENTIALLY ELIMINATE MENTION
OF SENSIBLE WEATHER.
TEMPS REMAIN NEAR TO SLIGHTLY ABOVE NORMAL. WINDS WILL KICK UP
THURSDAY AND WITH LOW RH`S COULD SEE SOME FIRE WEATHER PROBLEMS.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO KELY AND KTPH
THROUGH TUESDAY AFTERNOON. ISOLATED THUNDERSTORMS WILL CONTINUE TO
MOVE THROUGH EASTERN NEVADA THIS AFTERNOON AND EARLY
EVENING...AFFECTING MAINLY KEKO AND DISTANTLY KELY. THE USUAL GUSTY
WINDS AROUND STORMS...SHOWERS...AND VIRGA. DIMINISH OVERNIGHT BUT
FIRE UP AGAIN TUESDAY AFTERNOON.
&&
.FIRE WEATHER...MULTIPLE THUNDERSTORMS HAVE POPPED UP OVER 469 AND
470 TODAY. EXPECTING ACTIVITY TO TAPER OFF THIS EVENING. THE NEXT
CONVECTIVE PUSH WILL BE MONSOONAL IN NATURE...ALTHOUGH WETTING
RAINS WILL BE PROBABLE...ALTHOUGH NOT NECESSARILY COINCIDENT WITH
THE LIGHTNING STRIKES.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98/97
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
304 PM EDT MON AUG 10 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TUESDAY AND EXTEND INTO WEDNESDAY AS
A COLD FRONT MAKES ITS WAY INTO THE AREA. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT LATE WEDNESDAY...OFFERING SEASONABLE
AND MAINLY DRY CONDITIONS INTO NEXT WEEKEND. A CHANCE OF RAIN
MAY RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND
DIRECTS MOISTURE ONSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...CLOUD COVER HAS BEEN PRETTY EXTENSIVE ACROSS
THE INLAND HALF OF THE CWA...BUT COASTAL SECTIONS HAVE ONCE AGAIN
EXPERIENCED A GREAT EARLY-AUGUST DAY. MOISTURE WILL CONTINUE TO
INCREASE IN BOTH THE MID-LEVELS AND AT THE SURFACE...FINALLY
OVERCOMING THE VERY DRY AIR IN PLACE AS THE SURFACE RIDGE OVERHEAD
SHIFTS OFFSHORE. SHOWERS THAT HAD DEVELOPED WEST OF THE CWA HAVE
ERODED AS EXPECTED THANKS TO ENCOUNTERING DRY AIR...AND HIGH RES
GUIDANCE INCLUDING THE HRRR AND NSSL WRF BOTH KEEP THE CWA DRY
THROUGH TONIGHT. HAVE REMOVED MENTION OF POP FROM EVEN IN THE FAR
INLAND ZONES THROUGH DARK TO ACCOUNT FOR TRENDS IN SATELLITE AND
RADAR.
TONIGHT...COLUMN SATURATION WILL CONTINUE TO INCREASE WITH PWATS
RISING TOWARDS 2 INCHES BY TUESDAY MORNING. COLD FRONT APPROACHING
FROM THE WEST WILL BE NEAR THE CWA BY MORNING...WITH SHOWERS AND
THUNDERSTORMS INCREASING AHEAD OF IT. FORECAST PROFILES SUGGEST
ENOUGH SATURATION INLAND THAT POP HAS BEEN RAMPED UP TO HIGH CHC
FROM I-95 WESTWARD BY 8AM TUESDAY...WITH JUST SCHC ALONG THE
COAST...BUT MOST OF THE PRECIP WILL HOLD OFF UNTIL AFTER THIS PERIOD.
INCREASING CLOUD COVER AND CONTINUED LIGHT SOUTHERLY WINDS WILL KEEP
MINS ELEVATED TO ABOVE SEASONABLE NORMS TONIGHT. THE MAV AND MET ARE
IN GOOD AGREEMENT...AND HAVE FORECAST MORE CLOSELY TO THE SLIGHTLY
WARMER MAV NUMBERS. EXPECT LOWS IN THE 72-75 DEGREE RANGE THROUGHOUT
THE AREA.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE PRIME WEATHER CAPTION FOR TUE/WED IS RAIN
AS AN APPROACHING FRONTAL SYSTEM WITH RELATIVELY HIGH AMOUNTS OF
INGESTED PRECIPITABLE WATER...CROSSES THE APPALACHIAN MOUNTAINS
EARLY TUESDAY AND MOVES TO THE COAST TUESDAY NIGHT. IT APPEARS A
WEAK WAVE OF LOW PRESSURE MOVING NNE ALONG THE FRONT MAY SUSTAIN
ISOLATED COASTAL SHOWERS SLIGHTLY BEHIND THE DECAYING FRONTAL SYSTEM
ON WEDNESDAY. BEST FIT AND CONSENSUS QPF DEPICTIONS OF STORM/SYSTEM
TOTAL POINTS GENERALLY TO 0.50-0.75 INCHES OF RAIN TUE/WED AND
HIGHEST ALONG AREAS IN PROXIMITY TO THE COAST. A TREND OF DRYING
WILL PREVAIL ON WEDNESDAY ESPECIALLY INLAND...IN THE FACE OF
ISOLATED COASTAL SHOWERS.
POST-FRONTAL DOWNSLOPE WIND FLOW WEDNESDAY WITH LITTLE COLD AIR
ADVECTION WILL LIKELY RESULT IN A SEASONABLY WARM DAY WEDNESDAY
ALTHOUGH WE WILL OBSERVE SEVERAL DEGREES OF DEWPOINT DROPS THROUGH
WEDNESDAY...TAKING A SLIGHT EDGE OFF THE HUMIDITY LEVELS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING WILL PERSIST ACROSS THE
EAST/SOUTHEAST THROUGH SATURDAY WITH MORE OF A ZONAL PATTERN
DEVELOPING THEREAFTER. GENERALLY QUIET WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES FROM THE MIDWEST TO THE APPALACHIANS THROUGH THE
PERIOD. THE HIGH WILL WEAKEN WITH THE MID LEVEL TROUGH THUS LEAVING
A WEAK PRESSURE PATTERN BOTH AT THE SURFACE AND ALOFT. HAVE
CONTINUED THE SLIGHT CHANCE POPS WHICH ARE MOSTLY CONFINED TO THE
COASTAL AND OFFSHORE ZONES. THE TEMPERATURE CURVE FOLLOWS THE SAME
PROGRESSION WITH COOL READINGS EARLY ON...FRIDAY SHOULD BE THE
COOLEST WITH 850MB TEMPERATURES NEAR 15 DEGREES C. THERMAL PROFILES
SLOWLY MODIFY FROM THAT POINT ON. READINGS MAY ECLIPSE CLIMATOLOGY
JUST BY A DEGREE OR TWO BY THE END OF THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...A BIT TRICKY WITH RESPECT TO PRECIP THIS AFTERNOON.
CONVECTION ONGOING JUST WEST OF THE REGION AND THE MODELS ARE
SIMILAR IN BRINGING THE CONVECTION TO THE I-95 CORRIDOR...BUT
MOISTURE IS LIMITED AND HAVE REMOVED ANY MENTION OF SHOWERS DURING
THE DAYLIGHT HOURS. TONIGHT...ISOLATED CONVECTION POSSIBLE OVER
THE WESTERN THIRD OF THE REGION...WITH MID CLOUD CEILINGS DUE TO
CONVECTIVE DEBRIS. TUESDAY...SHOWERS ON THE INCREASE AS YET
ANOTHER COLD FRONT APPROACHES. CONVECTION COULD BECOME NUMEROUS
AFTER THE END OF THE FORECAST PERIOD WITH FRONTAL LIFT AND
INSTABILITY.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND STORMS TUESDAY NIGHT WITH
INTERMITTENT MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY WITH
ISOLATED MORNING CONVECTION. VFR THURSDAY THROUGH SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...WEAK RIDGE OF HIGH PRESSURE WILL SLOWLY SHIFT
OFFSHORE TONIGHT...SO ALTHOUGH THE GRADIENT WILL REMAIN LIGHT
KEEPING WIND SPEEDS TO 10 KTS OR LESS...DIRECTION WILL CONTINUE TO
VEER THROUGH TONIGHT...FROM CURRENT ESE ALL THE WAY TO SSW LATE.
CURRENT BUOY OBS SHOW A MIX OF 5 SEC AND 10 SEC WAVES...WITH THE 10
SEC WAVE DOMINANT DUE TO THE LIGHT WINDS...AND THESE WILL PERSIST
THROUGH THE PERIOD MAINTAINING WAVE HEIGHTS OF 2-3 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...MAIN MARINE HEADLINE THIS PERIOD REMAINS
APPROACH AND DECAY OF A COLD FRONTAL SYSTEM OVER THE COASTAL
WATERS DURING THE DAY WEDNESDAY. THIS MAY BRING A BRIEF PERIOD
OF N-NW WINDS WEDNESDAY...PRECEDED BY COASTAL RAINSHOWERS AND
ISOLATED TSTMS TUESDAY NIGHT. A FEW TSTMS MAY IMPACT THE OUTER
WATERS ON WEDNESDAY AS WELL SINCE THE FRONT MAY SLOWLY DISSIPATE
THERE MID-WEEK. SEAS WILL BUILD TO 3-4 FT TUESDAY NIGHT AHEAD OF
THE COLD FRONT IN 15-20 KT SW WINDS...POSSIBLY 5 FT VERY OUTER
PORTION. SEAS SETTLING TO 2-3 FT WED AFTN AND EVENING AS WIND
SPEEDS GO LIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE WILL MOVE FROM THE MIDWEST TO THE
APPALACHIANS THROUGH THE PERIOD. THE HIGH WILL SLOWLY WEAKEN LEAVING
A BENIGN PRESSURE PATTERN BY SATURDAY. FOR THURSDAY AND FRIDAY
WINDS WONT BE OVERWHELMING AND EXPECT A EAST/NORTHEAST DIRECTION IN
A RANGE OF 10-15 KNOTS...MOSTLY HOVERING IN THE LOWER END OF THE
RANGE. SPEEDS DROP TO TEN KNOTS AND BELOW BY SATURDAY. SIGNIFICANT
SEAS WILL BE 1-3 FEET WITH AN EQUAL MIX OF A SHORTER PERIOD WIND
WAVE AND SWELL COMPONENT.
&&
.EQUIPMENT...
AS OF 130 PM MONDAY...POWER TO THE ILM ASOS HAS BEEN LOST DUE TO
A POWER SURGE. A REPLACEMENT IS ON ORDER...BUT IT IS LIKELY THAT
ILM ASOS WILL BE WITHOUT AUTOMATED OBSERVATIONS THROUGH TODAY AND
PART OF TUESDAY. THE ILM TOWER SHOULD AMEND OBSERVATIONS UNTIL 11
PM TONIGHT...AND RESUME EARLY TUESDAY MORNING. OVERNIGHT OBS MAY
WILL BE MISSING FOR ALL PARAMETERS. AMD NOT SKED HAS BEEN APPENDED
TO THE ILM TAF AND WILL REMAIN AS SUCH UNTIL POWER IS RESTORED TO
THE SITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...SHK
AVIATION...JDW/DL
MARINE...JDW/MJC/SHK
EQUIPMENT...JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
252 PM EDT MON AUG 10 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY...
AND PUSH SOUTHEAST THROUGH THE AREA LATE TUESDAY THROUGH TUESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1020 AM MONDAY...
CURRENT FORECAST IS IN GOOD SHAPE. MAIN CHANGES WERE TO EXPAND IN
TIME AND AREA THE BAND OF PATCHY SHOWERS CURRENTLY TRACKING THROUGH
THE CWA... DRIVEN BY WEAK MOIST ISENTROPIC UPGLIDE IN THE LOW LEVELS
AND A WEAK MID LEVEL WAVE... AND TO DELAY AFTERNOON CONVECTION IN
THE WEST. HIGH-PW AIR (1.8-2.0") PERSISTS OVER CENTRAL NC WITH
CONSIDERABLE MID AND HIGH DEBRIS CLOUDINESS FROM UPSTREAM MCS ACTION
OVERSPREADING THE AREA FROM THE NW... AND THIS SHOULD SOMEWHAT CURB
THE POTENTIAL FOR INSTABILITY THIS AFTERNOON. EXTRAPOLATION WOULD
FAVOR ANY MCVS GENERATED BY LAST NIGHT`S THE CONVECTIVE COMPLEXES
ACROSS SRN KS/MO/IL INTO WRN KY/TN LIKELY TRACKING WELL TO OUR SW...
AND THIS TREND IS INDICATED BY THE NSSL WRF AND NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES. THESE MODEL PACKAGES ALSO SUGGEST THAT
THE CHANCE FOR DEEP CONVECTION EAST OF HIGHWAY 1 THIS AFTERNOON INTO
TONIGHT IS QUITE LOW... AND THE HRRR ALSO DEPICTS LITTLE TO NO
COVERAGE OVER ALL BUT THE FAR WRN CWA AFTERNOON THROUGH AT LEAST
23Z. AFTER SLOWLY TRENDING THE COVERAGE OF SHOWERS DOWN THIS MORNING
INTO EARLY AFTERNOON AS THEY TREND EASTWARD WITH WANING UPGLIDE...
HAVE REDUCED CONVECTION CHANCES TO SLIGHT OR NIL IN THE EAST THIS
AFTERNOON... AND HAVE CUT BACK COVERAGE IN THE WRN CWA A BIT AS
WELL. GIVEN THE GENERALLY MOSTLY CLOUDY SKIES TODAY... HAVE CUT A
COUPLE OF DEGREES OFF HIGHS... NOW RANGING FROM 84 TO 90. -GIH
EARLIER DISCUSSION AS OF 255 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE EXTENDING INTO EASTERN VA AND NC. MEANWHILE A WARM
FRONT EXTENDING FROM NEAR NASHVILLE TN SOUTHEAST TO NEAR SAVANNAH GA
WAS BEGINNING TO SLOWLY LIFT NORTHWARD...LIKELY LIFTING THROUGH
CENTRAL NC THIS AFTERNOON AND EVENING. FURTHER ALOFT...A RATHER WEAK
DIFFLUENT NORTHWEST FLOW ALOFT WAS EXPECTED TO STRENGTHEN AND
GRADUALLY BACK AND BECOME SOUTHWESTERLY BY LATE TONIGHT AS AN UPPER
TROUGH DROPS INTO THE GREAT LAKES REGION.
REGIONAL RADAR IMAGERY SHOWS SCT SHOWERS SLOWLY DEVELOPING AND
EXPANDING ACROSS THE YADKIN VALLEY AND THE WESTERN PIEDMONT OF
VA/NC/SC. THIS PRECIPITATION APPEARS TO BE ASSOCIATED WITH SOME
ISENTROPIC UPGLIDE NEAR THE 305K SURFACE ENHANCED BY A WEAK SHORT
WAVE ALOFT AND REMNANTS OF AN UPSTREAM MCS. NWP GUIDANCE SUGGESTS
THAT THESE SHOWERS MAY BECOME MORE NUMEROUS AS THEY MOVE INTO THE
WESTERN PIEDMONT TOWARD DAYBREAK. THE PRECIPITATION SHOULD BEGIN TO
DIMINISH LATE THIS MORNING BEFORE REACHING THE COASTAL PLAIN.
MUCH OF THE DAY TODAY SHOULD FEATURE A FAIR AMOUNT OF CLOUDINESS BUT
MAINLY DRY CONDITIONS ACROSS CENTRAL NC. WITH LITTLE FORCING FOR
ASCENT AND WITH ONLY WEAK INSTABILITY PRESENT THIS AFTERNOON AND
FAIRLY MEAGER MID LEVEL LAPSE RATES...CONVECTIVE COVERAGE SHOULD BE
RATHER LIMITED. THE ENVIRONMENT FOR CONVECTION BECOMES A LITTLE BIT
MORE FAVORABLE THIS EVENING AND OVERNIGHT ACROSS THE WESTERN
PIEDMONT AND TRIAD AREA AS LARGER SCALE FORCING APPROACHES AND MID
LEVEL LAPSE RATE ACCORDINGLY INCREASE. STILL...CONVECTION ALLOWING
MODELS HAVE TRENDED NOTICEABLY LESS ACTIVE FOR THIS AFTERNOON AND
TONIGHT WITH NOCTURNAL CONVECTION NOW APPEARING MORE FOCUSED ACROSS
VA/WV. HIGHS TODAY WILL BE COMPLICATED BY THE AMOUNT OF SUNSHINE AND
WITH A TREND TOWARD LESS PRECIPITATION AND PERHAPS THINNER CLOUDS
HAVE ADJUSTED MAXES UP EVER-SO-SLIGHTLY...HIGHS SHOULD RANGE SHOULD
RANGE FROM 84 TO 91. LOWS TONIGHT WILL BE MODERATED BY A GOOD DEAL
OF CLOUD COVER...LOWS SHOULD RANGE BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 AM MONDAY...
A STRENGTHENING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES AND
NORTHEAST DURING THE PERIOD WITH THE MAIN TROUGH AXIS SHIFTING
ACROSS CENTRAL NC TOWARD DAYBREAK WEDNESDAY. THE ASSOCIATED COLD
FRONT WILL MOVE ACROSS THE APPALACHIANS TUESDAY AFTERNOON AND
THROUGH CENTRAL NC TUESDAY NIGHT...REACHING THE COAST TOWARD
WEDNESDAY MORNING.
SCATTERED CONVECTION IS EXPECTED AHEAD OF THE FRONT TUESDAY MORNING
AND EARLY AFTERNOON. AS NOTED IN THE PREVIOUS DISCUSSION...THIS MAY
PLAY A ROLE IN SUBSEQUENT CONVECTION TUESDAY AFTERNOON AND EVENING.
WITH THE UPPER TROUGH CONTAINING MULTIPLE VORTICITY CENTERS...EXPECT
SHOWERS AND THUNDERSTORMS TO MOVE ACROSS CENTRAL NC IN MULTIPLE
CLUSTER OR BANDS THROUGHOUT THE AFTERNOON AS OPPOSED TO ONE WELL
ORGANIZED LINE. THE CLOUDS AND PRECIPITATION WITH THESE CLUSTERS
SHOULD RETARD INSTABILITY A BIT. SPC HAS CENTRAL NC OUTLOOKED WITH A
MARGINAL THREAT OF SEVERE STORMS WHICH SEEMS REASONABLE GIVEN THE
STRONGER DEEP LAYER FLOW AND BULK SHEAR VALUES OF 20-25 KTS
SUGGESTING SOME STORM ORGANIZATION POSSIBLE. CAPE VALUES SHOULD
RANGE FROM WEAK TO LOW END MODERATE WITH MLCAPE VALUES CLIMBING TO
THE 750-1250 J/KG RANGE. THIS ENVIRONMENT WOULD SUPPORT A
MULTICELLULAR/LINE SEGMENT CONVECTIVE MODE WITH A FEW STRONG STORMS
AND POSSIBLY A SEVERE THUNDERSTORMS WITH DAMAGING WINDS THE MOST
LIKELY THREAT. WITH A LINGERING SHORT WAVE TROUGH LIKELY TO MOVE
ACROSS CENTRAL NC LATE TUESDAY EVENING...ANOTHER ROUND OF STORMS IS
POSSIBLE WITH THIS FEATURE AND THE ASSOCIATED COLD FRONT. THE FRONT
SHOULD EXIT THE RAH CWA BETWEEN 06-12Z AND BRING THE PRECIPITATION
TO AN END. HIGHS IN THE 86 TO 91 RANGE WITH LOWS TUESDAY NIGHT IN
THE 65 TO 73 RANGE. -BLAES
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
THE MAIN FRONT WILL SHIFT OFFSHORE ON WEDNESDAY...WITH GENERAL UPPER
LEVEL TROUGHINESS LINGERING OVER THE CAROLINAS THROUGH MONDAY. AT
THE SURFACE...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
REMAIN OVERHEAD THROUGH MONDAY. WITH THAT IN MIND...MOST OF THE
EXTENDED PERIOD WILL REMAIN DRY...WITH JUST A SLIGHT CHANCE FOR
SHOWERS OVER THE WESTERN HALF OF THE STATE OVER THE WEEKEND.
TEMPERATURES DURING THE PERIOD WILL FEATURE HIGHS IN THE MID 80S TO
AROUND 90 DEGREES WITH OVERNIGHT LOWS GENERALLY IN THE MID 60S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM MONDAY...
AVIATION CONDITIONS WILL BE SUB-VFR FOR THE MAJORITY OF THE NEXT 24
HOURS AT INT/GSO... HOWEVER AT RDU/FAY/RWI... THE SUB-VFR CONDITIONS
WILL BE MORE SPORADIC WITH VFR DOMINATING AT LEAST THROUGH THIS
EVENING. A MOIST SOUTHWESTERLY SURFACE FLOW INTO NC AHEAD OF AN
APPROACHING COLD FRONT... COMBINED WITH LEFTOVER CLOUD COVER FROM
STORM COMPLEXES TO THE WEST AND NORTHWEST OF NC... WILL KEEP MOSTLY
CLOUDY SKIES AT ALL CENTRAL NC TERMINALS THROUGH TUE. CURRENT MVFR
CIGS AT INT/GSO ARE EXPECTED TO LIFT BRIEFLY TO MAINLY VFR AFTER 21-
22Z TODAY... BUT THEN DROP BACK DOWN TO VFR AND POTENTIALLY IFR
STARTING MID EVENING WITH NUMEROUS SHOWERS AND A FEW STORMS MOVING
IN MAINLY AFTER 01Z... LASTING WELL INTO THE OVERNIGHT HOURS WITH
PERIODIC MVFR VSBYS. MVFR CIGS AND PATCHY SHOWERS ARE LIKELY TO HOLD
AT INT/GSO THROUGH THE END OF THE TAF VALID PERIOD... WITH PATCHY
SHOWERS GIVING WAY TO MORE ORGANIZED THUNDERSTORMS TOWARD THE VERY
END OF THE TAF VALID PERIOD (18Z TUE). RDU/FAY/RWI COULD SEE A
PERIOD OF MVFR CIGS/VSBYS THROUGH THIS EVENING... BUT THE
PROBABILITIES ARE LOW (HIGHER AT RDU THAN AT FAY/RWI BUT STILL LOW).
AFTER 04Z... PATCHY SHOWERS ARE EXPECTED TO SHIFT EASTWARD NEARING
THESE TAF SITES... AND THEY MAY GENERATE A PERIOD OF MVFR OR BRIEFLY
IFR CIGS AND/OR MVFR VSBYS. SIMILAR TO INT/GSO... THE PATCHY MORNING
SHOWERS MAY GIVE WAY TO SCATTERED STORMS IN THE AFTERNOON.
LOOKING BEYOND 18Z TUE... SUB-VFR AND RAINY/STORMY CONDITIONS WILL
DOMINATE AT ALL SITES THROUGH MUCH OF TUE AFTERNOON AND EVENING...
WITH WINDS HOLDING FROM THE SW AT 9-15 KTS. AS THE FRONT PUSHES SE
THROUGH THE AREA WITH HIGH PRESSURE BUILDING IN... WE`LL SEE A NW-TO-
SE CLEARING TREND TO VFR CONDITIONS... WHICH WILL LAST INTO SAT
WITH LARGELY DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...RAH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 PM EDT MON AUG 10 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY...
AND PUSH SOUTHEAST THROUGH THE AREA LATE TUESDAY THROUGH TUESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1020 AM MONDAY...
CURRENT FORECAST IS IN GOOD SHAPE. MAIN CHANGES WERE TO EXPAND IN
TIME AND AREA THE BAND OF PATCHY SHOWERS CURRENTLY TRACKING THROUGH
THE CWA... DRIVEN BY WEAK MOIST ISENTROPIC UPGLIDE IN THE LOW LEVELS
AND A WEAK MID LEVEL WAVE... AND TO DELAY AFTERNOON CONVECTION IN
THE WEST. HIGH-PW AIR (1.8-2.0") PERSISTS OVER CENTRAL NC WITH
CONSIDERABLE MID AND HIGH DEBRIS CLOUDINESS FROM UPSTREAM MCS ACTION
OVERSPREADING THE AREA FROM THE NW... AND THIS SHOULD SOMEWHAT CURB
THE POTENTIAL FOR INSTABILITY THIS AFTERNOON. EXTRAPOLATION WOULD
FAVOR ANY MCVS GENERATED BY LAST NIGHT`S THE CONVECTIVE COMPLEXES
ACROSS SRN KS/MO/IL INTO WRN KY/TN LIKELY TRACKING WELL TO OUR SW...
AND THIS TREND IS INDICATED BY THE NSSL WRF AND NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES. THESE MODEL PACKAGES ALSO SUGGEST THAT
THE CHANCE FOR DEEP CONVECTION EAST OF HIGHWAY 1 THIS AFTERNOON INTO
TONIGHT IS QUITE LOW... AND THE HRRR ALSO DEPICTS LITTLE TO NO
COVERAGE OVER ALL BUT THE FAR WRN CWA AFTERNOON THROUGH AT LEAST
23Z. AFTER SLOWLY TRENDING THE COVERAGE OF SHOWERS DOWN THIS MORNING
INTO EARLY AFTERNOON AS THEY TREND EASTWARD WITH WANING UPGLIDE...
HAVE REDUCED CONVECTION CHANCES TO SLIGHT OR NIL IN THE EAST THIS
AFTERNOON... AND HAVE CUT BACK COVERAGE IN THE WRN CWA A BIT AS
WELL. GIVEN THE GENERALLY MOSTLY CLOUDY SKIES TODAY... HAVE CUT A
COUPLE OF DEGREES OFF HIGHS... NOW RANGING FROM 84 TO 90. -GIH
EARLIER DISCUSSION AS OF 255 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE EXTENDING INTO EASTERN VA AND NC. MEANWHILE A WARM
FRONT EXTENDING FROM NEAR NASHVILLE TN SOUTHEAST TO NEAR SAVANNAH GA
WAS BEGINNING TO SLOWLY LIFT NORTHWARD...LIKELY LIFTING THROUGH
CENTRAL NC THIS AFTERNOON AND EVENING. FURTHER ALOFT...A RATHER WEAK
DIFFLUENT NORTHWEST FLOW ALOFT WAS EXPECTED TO STRENGTHEN AND
GRADUALLY BACK AND BECOME SOUTHWESTERLY BY LATE TONIGHT AS AN UPPER
TROUGH DROPS INTO THE GREAT LAKES REGION.
REGIONAL RADAR IMAGERY SHOWS SCT SHOWERS SLOWLY DEVELOPING AND
EXPANDING ACROSS THE YADKIN VALLEY AND THE WESTERN PIEDMONT OF
VA/NC/SC. THIS PRECIPITATION APPEARS TO BE ASSOCIATED WITH SOME
ISENTROPIC UPGLIDE NEAR THE 305K SURFACE ENHANCED BY A WEAK SHORT
WAVE ALOFT AND REMNANTS OF AN UPSTREAM MCS. NWP GUIDANCE SUGGESTS
THAT THESE SHOWERS MAY BECOME MORE NUMEROUS AS THEY MOVE INTO THE
WESTERN PIEDMONT TOWARD DAYBREAK. THE PRECIPITATION SHOULD BEGIN TO
DIMINISH LATE THIS MORNING BEFORE REACHING THE COASTAL PLAIN.
MUCH OF THE DAY TODAY SHOULD FEATURE A FAIR AMOUNT OF CLOUDINESS BUT
MAINLY DRY CONDITIONS ACROSS CENTRAL NC. WITH LITTLE FORCING FOR
ASCENT AND WITH ONLY WEAK INSTABILITY PRESENT THIS AFTERNOON AND
FAIRLY MEAGER MID LEVEL LAPSE RATES...CONVECTIVE COVERAGE SHOULD BE
RATHER LIMITED. THE ENVIRONMENT FOR CONVECTION BECOMES A LITTLE BIT
MORE FAVORABLE THIS EVENING AND OVERNIGHT ACROSS THE WESTERN
PIEDMONT AND TRIAD AREA AS LARGER SCALE FORCING APPROACHES AND MID
LEVEL LAPSE RATE ACCORDINGLY INCREASE. STILL...CONVECTION ALLOWING
MODELS HAVE TRENDED NOTICEABLY LESS ACTIVE FOR THIS AFTERNOON AND
TONIGHT WITH NOCTURNAL CONVECTION NOW APPEARING MORE FOCUSED ACROSS
VA/WV. HIGHS TODAY WILL BE COMPLICATED BY THE AMOUNT OF SUNSHINE AND
WITH A TREND TOWARD LESS PRECIPITATION AND PERHAPS THINNER CLOUDS
HAVE ADJUSTED MAXES UP EVER-SO-SLIGHTLY...HIGHS SHOULD RANGE SHOULD
RANGE FROM 84 TO 91. LOWS TONIGHT WILL BE MODERATED BY A GOOD DEAL
OF CLOUD COVER...LOWS SHOULD RANGE BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 AM MONDAY...
A STRENGTHENING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES AND
NORTHEAST DURING THE PERIOD WITH THE MAIN TROUGH AXIS SHIFTING
ACROSS CENTRAL NC TOWARD DAYBREAK WEDNESDAY. THE ASSOCIATED COLD
FRONT WILL MOVE ACROSS THE APPALACHIANS TUESDAY AFTERNOON AND
THROUGH CENTRAL NC TUESDAY NIGHT...REACHING THE COAST TOWARD
WEDNESDAY MORNING.
SCATTERED CONVECTION IS EXPECTED AHEAD OF THE FRONT TUESDAY MORNING
AND EARLY AFTERNOON. AS NOTED IN THE PREVIOUS DISCUSSION...THIS MAY
PLAY A ROLE IN SUBSEQUENT CONVECTION TUESDAY AFTERNOON AND EVENING.
WITH THE UPPER TROUGH CONTAINING MULTIPLE VORTICITY CENTERS...EXPECT
SHOWERS AND THUNDERSTORMS TO MOVE ACROSS CENTRAL NC IN MULTIPLE
CLUSTER OR BANDS THROUGHOUT THE AFTERNOON AS OPPOSED TO ONE WELL
ORGANIZED LINE. THE CLOUDS AND PRECIPITATION WITH THESE CLUSTERS
SHOULD RETARD INSTABILITY A BIT. SPC HAS CENTRAL NC OUTLOOKED WITH A
MARGINAL THREAT OF SEVERE STORMS WHICH SEEMS REASONABLE GIVEN THE
STRONGER DEEP LAYER FLOW AND BULK SHEAR VALUES OF 20-25 KTS
SUGGESTING SOME STORM ORGANIZATION POSSIBLE. CAPE VALUES SHOULD
RANGE FROM WEAK TO LOW END MODERATE WITH MLCAPE VALUES CLIMBING TO
THE 750-1250 J/KG RANGE. THIS ENVIRONMENT WOULD SUPPORT A
MULTICELLULAR/LINE SEGMENT CONVECTIVE MODE WITH A FEW STRONG STORMS
AND POSSIBLY A SEVERE THUNDERSTORMS WITH DAMAGING WINDS THE MOST
LIKELY THREAT. WITH A LINGERING SHORT WAVE TROUGH LIKELY TO MOVE
ACROSS CENTRAL NC LATE TUESDAY EVENING...ANOTHER ROUND OF STORMS IS
POSSIBLE WITH THIS FEATURE AND THE ASSOCIATED COLD FRONT. THE FRONT
SHOULD EXIT THE RAH CWA BETWEEN 06-12Z AND BRING THE PRECIPITATION
TO AN END. HIGHS IN THE 86 TO 91 RANGE WITH LOWS TUESDAY NIGHT IN
THE 65 TO 73 RANGE. -BLAES
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 255 AM MONDAY...
WEDNESDAY THROUGH FRIDAY... UPPER AIR PATTERN WILL BE DOMINATED BY A
STRONG...AMPLIFIED RIDGE ALONG THE SPINE OF THE ROCKIES...AND A L/W
TROUGH ALONG THE EASTERN SEABOARD. THIS TROUGH IS AT ITS MOST
AMPLIFIED/DEEPEST AT MID WEEK THEN WEAKENS/BROADENS BY THE END OF
THE WEEK. THIS SET-UP WILL SPREAD A DRIER STABLE AIR MASS INTO
CENTRAL NC ON WEDNESDAY WHICH SHOULD LINGER THROUGH THE REMAINDER OF
THE WORK WEEK AS AN AREA OF HIGH PRESSURE AT THE SURFACE BUILDS INTO
THEN SETTLES OVERHEAD BY FRIDAY. ASIDE FROM A SLIGHT CHANCE OF A
SHOWER EARLY WEDNESDAY OVER THE SE COUNTIES AS A COLD FRONT EXITS
THE REGION...EXPECT DRY WEATHER WEDNESDAY THROUGH FRIDAY...AND
TEMPERATURES AVERAGING FAIRLY CLOSE TO NORMAL FOR MID AUGUST. ONE
THING THAT WILL BE LACKING WILL BE THE TYPICAL LATE SUMMER HUMIDITY
AS AFTERNOON DEWPOINTS WILL DROP INTO THE 50S-LOWER 60S EACH
AFTERNOON...ESPECIALLY ON THURSDAY AND FRIDAY. THIS WILL LEAD TO
FAIRLY COMFORTABLE CONDITIONS FOR MID-AUGUST.
FOR SATURDAY THROUGH SUNDAY...THE UPPER RIDGE BECOMES ORIENTATED SW-
NE FROM THE DESERT SW INTO THE GREAT LAKES WHILE THE L/W TROUGH
MAINTAINS A PRESENCE ALONG THE EASTERN SEABOARD. THE SFC HIGH
WEAKENS WITH TIME BUT CONTINUES TO INFLUENCE THE SENSIBLE WEATHER
OVER CENTRAL NC AS THE LOW LEVEL FLOW WILL MAINTAIN A FAIRLY MILD
AIR MASS FOR THIS TIME OF YEAR. ENOUGH MOISTURE MAY CREEP BACK INTO
SECTIONS OF OUR COASTAL PLAIN AND SANDHILL COUNTIES BY SUNDAY TO
SPARK AN ISOLATED SHOWER OR STORM IN THE AFTERNOON. THE ATMOSPHERE
WILL UNDERGO SLIGHT MODIFICATION...LEADING TO TEMPS SLIGHTLY ABOVE
NORMAL BY SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM MONDAY...
AVIATION CONDITIONS WILL BE SUB-VFR FOR THE MAJORITY OF THE NEXT 24
HOURS AT INT/GSO... HOWEVER AT RDU/FAY/RWI... THE SUB-VFR CONDITIONS
WILL BE MORE SPORADIC WITH VFR DOMINATING AT LEAST THROUGH THIS
EVENING. A MOIST SOUTHWESTERLY SURFACE FLOW INTO NC AHEAD OF AN
APPROACHING COLD FRONT... COMBINED WITH LEFTOVER CLOUD COVER FROM
STORM COMPLEXES TO THE WEST AND NORTHWEST OF NC... WILL KEEP MOSTLY
CLOUDY SKIES AT ALL CENTRAL NC TERMINALS THROUGH TUE. CURRENT MVFR
CIGS AT INT/GSO ARE EXPECTED TO LIFT BRIEFLY TO MAINLY VFR AFTER 21-
22Z TODAY... BUT THEN DROP BACK DOWN TO VFR AND POTENTIALLY IFR
STARTING MID EVENING WITH NUMEROUS SHOWERS AND A FEW STORMS MOVING
IN MAINLY AFTER 01Z... LASTING WELL INTO THE OVERNIGHT HOURS WITH
PERIODIC MVFR VSBYS. MVFR CIGS AND PATCHY SHOWERS ARE LIKELY TO HOLD
AT INT/GSO THROUGH THE END OF THE TAF VALID PERIOD... WITH PATCHY
SHOWERS GIVING WAY TO MORE ORGANIZED THUNDERSTORMS TOWARD THE VERY
END OF THE TAF VALID PERIOD (18Z TUE). RDU/FAY/RWI COULD SEE A
PERIOD OF MVFR CIGS/VSBYS THROUGH THIS EVENING... BUT THE
PROBABILITIES ARE LOW (HIGHER AT RDU THAN AT FAY/RWI BUT STILL LOW).
AFTER 04Z... PATCHY SHOWERS ARE EXPECTED TO SHIFT EASTWARD NEARING
THESE TAF SITES... AND THEY MAY GENERATE A PERIOD OF MVFR OR BRIEFLY
IFR CIGS AND/OR MVFR VSBYS. SIMILAR TO INT/GSO... THE PATCHY MORNING
SHOWERS MAY GIVE WAY TO SCATTERED STORMS IN THE AFTERNOON.
LOOKING BEYOND 18Z TUE... SUB-VFR AND RAINY/STORMY CONDITIONS WILL
DOMINATE AT ALL SITES THROUGH MUCH OF TUE AFTERNOON AND EVENING...
WITH WINDS HOLDING FROM THE SW AT 9-15 KTS. AS THE FRONT PUSHES SE
THROUGH THE AREA WITH HIGH PRESSURE BUILDING IN... WE`LL SEE A NW-TO-
SE CLEARING TREND TO VFR CONDITIONS... WHICH WILL LAST INTO SAT
WITH LARGELY DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...WSS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1140 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1124 AM CDT MON AUG 10 2015
LATEST VISIBLE SATELLITE SHOWING A CUMULUS FIELD INITIATING AS
CONVECTIVE TEMPERATURES HAVE BEEN REACHED. QUESTION BECOMES
WHETHER OR NOT A SHORTWAVE TROUGH SLIDING INTO CENTRAL NORTH
DAKOTA AND THE JAMES RIVER VALLEY THIS AFTERNOON WILL BE ABLE TO
GENERATE AN ISOLATED RAIN SHOWER(S) GIVEN SUCH A SHALLOW LAYER OF
HIGHER RELATIVE HUMIDITIES PER TIME HEIGHT CROSS SECTIONS. THE
HIGH RESOLUTION MODELS MAINTAIN THE IDEA OF ISOLATED CELLS
DEVELOPING WHILE THE NAM/GFS KEEP IT DRY. THE RAP13 PUTS 0.01 ON
THE SOUTH OF THE TURTLE MOUNTAINS AND PUSHES THIS AREA NEAR THE
NORTHERN JAMES RIVER VALLEY. DESPITE THE EXPECTED CUMULUS FIELD
GROWING IN COVERAGE WITH STRENGTHENING LOW LEVEL LAPSE RATES THIS
AFTERNOON...WILL KEEP THE FORECAST DRY. THE CHANCE FOR RECEIVING
MEASURABLE PRECIPIATION AND EXACTLY WHERE REMAINS VERY LOW AT THIS
TIME. FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 815 AM CDT MON AUG 10 2015
12Z BISMARCK SKEW-T SHOWS A CONVECTIVE TEMPERATURE OF 77F TODAY
WHICH WILL BE REACHED BETWEEN 16Z-17Z/11AM-NOON CDT. EXPECTING
SOME CUMULUS TO DEVELOP...HOWEVER TIME-HEIGHT CROSS SECTIONS SHOW
LIMITED MOISTURE IN THE 850-700MB LAYER...WITH DRIER AIR ABOVE.
LATEST WATER VAPOR IMAGERY LOOP REVEALS A SHORTWAVE/VORTICITY LOBE
LOCATED IN FAR SOUTHEAST SASKATCHEWAN EXTENDING INTO WESTERN NORTH
DAKOTA. THIS SHORTWAVE IS PICKED UP BY THE GFS AND IS FORECAST TO
REACH THE JAMES RIVER VALLEY 21Z-00Z. 850MB-700MB LAPSE RATES
FORECAST AT 9.5C/KM LATE THIS AFTERNOON IN CENTRAL NORTH DAKOTA.
HI RESOLUTION MODELS HRRR/ARW WEST/NMM WEST INDICATE ISOLATED
SHOWERS BETWEEN BISMARCK AND JAMESTOWN 21Z-00Z. THE PREVIOUS
DISCUSSION MENTIONED THIS POTENTIAL. BUFKIT SOUNDINGS CURRENTLY
MAINTAIN A SHALLOW POCKET OF MOISTURE REMAINING IN PLACE LATE THIS
AFTERNOON WHEN THE MAX OMEGA/VERTICAL MOTION IN THE LOWEST LAYERS
IS REACHED. WITH VERY MINIMAL AREAL COVERAGE AT THIS TIME...WILL
KEEP THINGS DRY AND WATCH THE TRENDS AND ADJUST IF NEEDED LATER
THIS MORNING. FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 542 AM CDT MON AUG 10 2015
MADE A QUICK UPDATE TO ADD PATCHY FOG FROM HETTINGER...THOUGH
WASHBURN...TO RUGBY AND ROLETTE. OBSERVATIONS THIS MORNING HAVE
FAVORED THAT REGION FOR FOG...AND THIS ALSO LINES UP WITH THE
LATEST ITERATIONS OF THE HRRR AND RAP13. A COUPLE ROGUE SHOWERS
DEVELOPED OVERNIGHT IN PARTS OF LOGAN AND MCINTOSH COUNTIES...BUT
THOSE HAVE DISSIPATED. THE REMAINDER OF THE FORECAST IS ON TRACK
AND ONLY ADJUSTED TO CAPTURE THE LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT MON AUG 10 2015
A QUIET START TO THE DAY IS EXPECTED WITH HIGH PRESSURE IN PLACE
AT THE SURFACE ACROSS THE NORTHERN PLAINS. WILL HAVE TO MONITOR
VISIBILITIES OVER THE NEXT FEW HOURS WITH LOW TEMPERATURE /
DEWPOINT SPREADS...OTHERWISE SKIES WILL BE MOSTLY SUNNY EARLY THIS
MORNING.
A POTENTIAL CONCERN FOR TODAY IS THE CHANCE FOR AN ISOLATED SHOWER
OR THUNDERSTORM THIS AFTERNOON. SOME OF THE HI-RES MODEL
SOLUTIONS HAVE HINTED AT THE POSSIBILITY OF AN ISOLATED SHOWER AS
LOW LEVEL LAPSE RATES STEEPEN THIS AFTERNOON. FORECAST SOUNDINGS
SHOW ONLY A SMALL AREA OF INCREASED MOISTURE (RELATIVE HUMIDITY)
THIS AFTERNOON AROUND H85...WITH VERY DRY AIR IN PLACE IN THE LOW
LEVELS. FOR NOW...WILL STAY WITH THE DRY FORECAST AND ONLY SHOW
SOME INCREASE IN CLOUDS AS CUMULUS DEVELOPS THIS AFTERNOON. HIGH
TEMPERATURES TODAY WILL BE IN THE 80S.
TONIGHT WILL SEE CLEARING SKIES AS THE CUMULUS DISSIPATES DURING
THE EVENING. LOWS SHOULD GENERALLY BE IN THE MID 50S TO NEAR 60.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 314 AM CDT MON AUG 10 2015
DETERMINISTIC MODELS AND ENSEMBLE OUTPUT CONTINUE TO INDICATE
STRONG UPPER LEVEL RIDGE BUILDING ACROSS WESTERN NORTH AMERICA AND
SLOWLY MOVING ACROSS THE NORTHERN PLAINS BY LATE WEEK AS DEEP
UPPER LOW MOVES INTO THE PAC NW BY THU/FRI. HIGH TEMPS ACROSS
WESTERN AND CENTRAL ND WILL REACH MID/UPPER 90S BY WEDNESDAY AND
THURSDAY WITH THE HIGHEST TEMPS ACROSS THE WEST. TEMPS WILL REMAIN
ABOVE NORMAL...BUT SLIGHTLY LOWER BY FRI AND SAT AS UPPER LEVEL
RIDGE AXIS SLOWLY PUSHES EAST OF US. MODELS GENERATE SOME
CONVECTIVE PRECIP TUE NIGHT AND WED WITH GFS INDICATING SOME
ELEVATED INSTABILITY AND A LOW LEVEL JET STRENGTHENING TUE NIGHT
AND UP TO 2000 J/KG OF SURFACE BASED CAPE ON WEDNESDAY. PROXIMITY
OF UPPER LEVEL RIDGE AND GENERAL ANTICYCLONIC FLOW WILL LIMIT
CONVECTIVE POTENTIAL...BUT AN ISOLATED SHOWER OR THUNDERSTORM IS
NOT OUT OF THE QUESTION WITH MODELS SHOWING A FEW WEAK SHORTWAVE
TROUGHS RIDING OVER THE RIDGE. BETTER CHANCE FOR PRECIP WILL BEGIN
FRIDAY EVENING AS COLD FRONT MOVES THROUGH THE REGION ON SATURDAY
PER GFS/ECMWF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1124 AM CDT MON AUG 10 2015
VFR CIGS/VSBYS NEXT 24HR...WITH LIGHT WINDS. A SCT CUMULUS FIELD
WILL GROW THROUGH MONDAY AFTERNOON WITH BKN CIGS AT 5000FT
EXPECTED AT KJMS. THE RISK FOR ANY SHOWERS AT KBIS OR KJMS REMAIN
TOO LOW FOR ANY MENTION AT THIS TIME. THE CUMULUS WILL DISSIPATE
AFTER SUNSET WITH A CLEAR SKY TO FOLLOW FOR THE REMAINDER OF THE
TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...CK
LONG TERM...JNS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
212 PM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
NO REAL CHANGES TO THE FORECAST. TWEAKED POPS A TAD TO ACCOUNT
FOR DEVELOPING CONVECTION. OTHERWISE, NO OTHER CHANGES ARE
EXPECTED.
PREVIOUS DISCUSSION...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY
WISE/BEST...NOT TO RUN WITH ANY ONE MODEL SOLUTION. WITH
ADJUSTMENTS BEING MADE DURING THE COURSE OF THE DAY AND EVENING
BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
UPPER TROUGH ACROSS THE EASTERN U.S. ALONG WITH SEVERAL EMBEDDED
SHORTWAVES...WILL KEEP A MENTION OF SHOWERS AND THUNDERSTORMS IN
THE FORECAST FOR THE SHORT TERM PERIOD. IN ADDITION...SOMEWHAT
COOLER WEATHER WILL BE REALIZED TOO. THE POTENTIAL FOR A MORE
POTENT WAVE IS POSSIBLE WEDNESDAY AFTERNOON...BUT THIS STILL
REMAINS IN QUESTION AS MODELS VARY ON THE HANDLING OF THIS
SITUATION. HIGH PRESSURE THEN NUDGES IN FROM THE WEST THIS
THURSDAY AND FRIDAY...FOR A BRIEF BREAK IN THE WEATHER.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WEEKEND AND BEYOND REMAINS RATHER UNCERTAIN. ANOTHER FRONT WILL
APPROACH OVER THE WEEKEND. GFS TENDS TO BRING THE FRONTAL BOUNDARY
THROUGH THE CWA OVER THE WEEKEND...WITH SHOWERS AND THUNDERSTORMS.
WHILE ECMWF IS A DRIER SOLUN...AND TENDS TO WASH OUT THE FRONT
ACROSS THE NORTHERN PART OF CWA. FOR NOW...WENT AHEAD AND PUT A
SLIGHT CHANCE TO CHANCE POPS ACROSS THE CWA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
INCREASED THUNDERSTORM COVERAGE OVER MUCH OF THE REGION THIS
AFTERNOON WITH LOCALIZED MVFR AND POSSIBLE IFR IN SHRA/TSRA/CIGS.
COLD FRONT TO PUSH THROUGH OVERNIGHT TONIGHT WITH MVFR/IFR
CIGS/SHRA/TSRA WITH THE FRONT. BEHIND THE FRONT LINGERING MVFR/IFR
SHOWERS/FOG/CIGS TO 12Z TUESDAY AND LINGER PAST 12Z TUESDAY IN THE
WV MOUNTAINS. CONDITIONS IMPROVE TO VFR...MAINLY BETWEEN 15Z- 18Z
TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M M
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H M H H H H H
EKN CONSISTENCY H H H H H H M M M M M M
PKB CONSISTENCY H H H H H H M M M M M M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 18Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...JS
SHORT TERM...SL
LONG TERM...SL
AVIATION...JS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
156 PM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NO REAL CHANGES TO THE FORECAST. TWEEKED POPS A TAD TO ACCOUNT FOR
DEVELOPING CONVECTION. OTHERWISE, NO OTHER CHANGES ARE EXPECTED.
PREVIOUS DISCUSSION...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY
WISE/BEST...NOT TO RUN WITH ANY ONE MODEL SOLUTION. WITH
ADJUSTMENTS BEING MADE DURING THE COURSE OF THE DAY AND EVENING
BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
INCREASED THUNDERSTORM COVERAGE OVER MUCH OF THE REGION THIS
AFTERNOON WITH LOCALIZED MVFR AND POSSIBLE IFR IN SHRA/TSRA/CIGS.
COLD FRONT TO PUSH THROUGH OVERNIGHT TONIGHT WITH MVFR/IFR
CIGS/SHRA/TSRA WITH THE FRONT. BEHIND THE FRONT LINGERING MVFR/IFR
SHOWERS/FOG/CIGS TO 12Z TUESDAY AND LINGER PAST 12Z TUESDAY IN THE
WV MOUNTAINS. CONDITIONS IMPROVE TO VFR...MAINLY BETWEEN 15Z- 18Z
TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M M
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H M H H H H H
EKN CONSISTENCY H H H H H H M M M M M M
PKB CONSISTENCY H H H H H H M M M M M M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 18Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...JS/KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...JS
AREA FORECAST DISCUSSION
NWS NORMAN OK
1226 PM CDT MON AUG 10 2015
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE.
ISO-SCT -SHRA/-TSRA WILL AFFECT SOME SITES MAINLY NORTH OF KHBR-
KOUN THROUGH 21Z. ADDITIONAL SHRA/TSRA MAY OCCUR AFTER 21Z...BUT
ONLY KEPT PROB30 MENTION NEAR KWWR AND KGAG 06-10Z AS CONFIDENCE
OF OCCURRENCE REMAINS RATHER LOW.
PATCHES OF MVFR/IFR CONDITIONS MAY OCCUR NORTH OF KHBR-KOKC 08-16Z...
PARTICULARLY NEAR KWWR AND KGAG...BUT DID NOT MENTION DUE TO LOW
CONFIDENCE OF OCCURRENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 1057 AM CDT MON AUG 10 2015/
UPDATE...
LOWERED TEMPS A FEW DEGREES ACROSS THE NORTH AND ADJUSTED POPS
SLIGHTLY.
DISCUSSION...
SCATTERED SHOWERS AND STORMS CONTINUE ALONG A WEAK MID LEVEL
CONVERGENCE ZONE ACROSS NORTH CENTRAL OK. THIS ZONE WILL SLOWLY
SHIFT SOUTHWARD DURING THE DAY BUT WITH LITTLE TO NO OTHER
SUPPORT PRESENT (LLJ DISSIPATING) EXPECT COVERAGE WILL DIMINISH
THROUGH THIS AFTERNOON. THE HRRR APPEARS TO HAVE A PRETTY GOOD
HANDLE ON THE FORECAST SO WEIGHTED POPS HEAVILY TOWARDS IT.
TEMPS WHERE ALSO LOWERED 2-4 DEGREES ACROSS NORTHERN OK...AND
PORTIONS OF CENTRAL OK...WHERE CLOUD COVER WILL LIKELY LINGER
THROUGH THE DAY. ALL UPDATED PRODUCTS HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 338 AM CDT MON AUG 10 2015/
DISCUSSION...
MAIN CONCERNS WILL BE PRECIP ACROSS THE NORTH AND HEAT FARTHER
SOUTH TODAY AND THEN COOL-OFF AND PRECIP CHANCES THIS WEEK.
CONT TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS NORTHWEST
INTO NORTHERN OKLAHOMA THIS MORNING NEAR A SLOW MOVING COLD FRONT.
THIS FRONT IS A BIT SLOWER THAN MODELS HAVE BEEN SHOWING. THIS
WILL ALLOW FOR TEMPS TO BE A BIT WARMER ACROSS PARTS OF THE AREA
TODAY. BECAUSE OF THIS WE WILL END UP WITH SOME HIGHER HEAT
INDICES AND WILL NECESSITATE THE NEED TO BRING THE HEAT ADVISORY
FARTHER NORTH INTO CENTRAL OKLAHOMA.
FRONT STILL EXPECTED TO PUSH SOUTH TOWARD THE RED RIVER BY TUESDAY
MORNING. SLIGHTLY COOLER TEMPS EXPECTED BEHIND THE FRONT. AS THIS
IS OCCURRING... UPPER RIDGE WILL BE BUILDING BACK NORTH ACROSS THE
SOUTHERN/CENTRAL ROCKIES. MODELS CONT TO INDICATE AT LEAST A
CHANCE FOR SOME ADDITIONAL PRECIP CHANCES INTO THE MIDDLE OF THE
WEEK AS WE COME UNDER THE INFLUENCE OF WEAK NORTHWEST FLOW.
HOWEVER TODAY`S MODEL RUNS HAVE SHIFTED THE MOISTURE PLUME FARTHER
WEST AND KEEP MUCH IN THE WAY OF PRECIP CONFINED TO FAR WESTERN
OKLAHOMA AND THE EASTERN TEXAS PANHANDLE AS WE GET INTO WED/THU
TIMEFRAME.
BEYOND THIS IT APPEARS THAT MOISTURE PLUME WILL DISSIPATE AND
UPPER FLOW BECOMES MORE NORTHERLY AS UPPER RIDGE CONT BUILD NORTH
AND NORTHEAST INTO THE CENTRAL AND NORTHERN PLAINS. ALTHOUGH
DRY... THIS PATTERN SHOULD KEEP THE HOTTEST TEMPS TO OUR WEST AND
NORTH BY LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 96 74 90 70 / 30 20 10 10
HOBART OK 97 74 93 70 / 30 20 20 20
WICHITA FALLS TX 104 76 97 73 / 0 10 20 10
GAGE OK 91 70 87 68 / 50 30 30 20
PONCA CITY OK 92 73 89 68 / 60 10 0 10
DURANT OK 104 77 97 73 / 0 10 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR OKZ025>032-039>043-
045>048-050>052.
TX...NONE.
&&
$$
03/14/17
AREA FORECAST DISCUSSION
NWS MEDFORD OR
231 PM PDT MON AUG 10 2015
.DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER LOW MARCHING
SOUTH ALONG 130 W. IT ALSO SHOWS A WEAK SHORTWAVE MOVING INTO
SOUTHWEST OREGON BRINGING HIGH AND MID LEVEL CLOUDS WHICH WILL
CONTINUE TO MOVE NORTHEAST. THE STRONGER SHORTWAVE THAT MOVED
THROUGH LAKE AND EASTERN KLAMATH COUNTY HAS MOVED NORTH OF OUR AREA
AND INCREASED LIGHTNING STRIKES HAVE SHOWN UP IN NORTHEAST OREGON
AND TOWARDS THE BLUE MOUNTAINS. GENERALLY CLEAR SKIES ARE IN ITS
WAKE, BUT CUMULUS ARE STARTING TO BUILD UP OVER THE HIGHER TERRAIN
ALONG AND EAST OF THE CASCADES AND NORTHERN CAL.
LOOKING AT DATA SUGGEST THE BEST CHANCE FOR SCATTERED THUNDERSTORMS
WILL BE LATE THIS AFTERNOON AND EVENING AND MOST CENTERED OVER THE
CASCADES. THE MODELS SHOW THE LOWEST LI`S AND HIGHEST BOUNDARY LAYER
CAPE VALUES AND THETA E CONVERGENCE IN THESE AREAS LATE THIS
AFTERNOON. IN ADDITION THE 700 MB WINDS AND THE 700-500MB WINDS WILL
BE FROM THE SOUTH, THEN SHIFT EVER SO SLIGHTLY TO THE SOUTH TO
SOUTHWEST THIS EVENING. THEREFORE WE THINK THE MAJORITY OF
THUNDERSTORMS WILL REMAIN IN THESE AREAS LATE THIS AFTERNOON AND
EVENING. HOWEVER WINDS ALOFT WILL BE STRONGER, THEREFORE STORMS THAT
FORM OVER WESTERN SISKIYOUS COUNTY AND SISKIYOU MOUNTAINS WILL GET
CARRIED NORTH INTO THE WEST SIDE VALLEYS, BUT THEY WILL BE RUNNING
IN AN ENVIRONMENT THAT IS LESS UNSTABLE AND ALSO WITH LESS MID LEVEL
MOISTURE. ALSO STORMS THAT FORM OVER THE CASCADES COULD GET PULLED
SLIGHTLY WESTWARD AND SCATTERED STORMS ARE POSSIBLE ALONG THE
FOOTHILLS OF THE CASCADES IN EASTERN DOUGLAS COUNTY.
OF NOTE THE PAST SEVERAL RUNS OF HIGH RES HRRR MODEL (WHICH UPDATES
HOURLY) CONTINUES TO SHOW VERY LITTLE ACTIVITY FROM THE CASCADES
WEST. IT ACTUALLY SHOWS A FRONTAL BOUNDARY ARRIVING AT THE COAST BY
THIS EVENING USHERING MORE STABLE CONDITIONS BRINGING LIGHT RAIN
WITH MOST OF THE CONVECTION IN MODOC AND LAKE COUNTY. MOST OF THE
CONVECTIVE FEEDBACK IS EAST OF THE CASCADES IN PARTS OF KLAMATH AND
LAKE COUNTY. NOT SURE IF THIS IS CORRECT, BUT IT MAY BE ON TO
SOMETHING GIVEN THE CONSISTENCY FROM RUN TO RUN. SO ITS ENTIRELY
POSSIBLE NOT MUCH WILL HAPPEN WEST OF THE CASCADES.
TONIGHT, THE MODELS ARE IN FRIARLY GOOD AGREEMENT SHOWING WINDS AT
700 AND 700-500MB REMAIN SOUTH TO SOUTHWEST. THE NAM SHOWS MORE OF A
SOUTHEAST COMPONENT OVERNIGHT TONIGHT, BUT THE GFS DOES NOT. THE NAM
SHOWS LIFTED INDICES (LI`S) LOWERING TO AROUND -5 C ALONG THE
COOS/DOUGLAS COUNTY LINE, BUT SUSPECT THAT MAY BE OVERDONE. IN
CONTRAST THE GFS SHOWS LI`S AROUND -1C. THE NAM CONTINUES TO SHOW A
SHORTWAVE MOVING WEST OF THE CASCADES OVERNIGHT TONIGHT, BUT THE GFS
IS MUCH WEAKER. BECAUSE OF THE ABOVE MENTIONED REASONS, WE THINK
THERE WILL BE NOCTURNAL STORMS WEST OF THE CASCADES, BUT THEY WILL
BE ISOLATED.
ON TUESDAY MOST OF THE INSTABILITY WILL BE WEST OF THE CASCADES.
HOWEVER WE`LL ALSO HAVE A MARINE INFLUENCE NEAR THE COAST WHICH
SHOULD STABILIZE THINGS SOME, SO WE DON`T THINK THUNDERSTORMS WILL
BE A CONCERN THERE. SHORTWAVES WILL ROTATE IN FROM THE SOUTHEAST
AHEAD OF THE UPPER LOW AND THIS IN COMBINATION WITH LOWEST LI`S AND
HIGHEST BL CAPE CENTERED FROM WESTERN SISKIYOU COUNTY NORTHEAST
TOWARDS EASTERN DOUGLAS COUNTY COULD BE ENOUGH TO GENERATE ISOLATED
THUNDERSTORMS. OF NOTE THE HIGHEST BL CAPE VALUES AND LOWEST LI`S
ARE IN THE NORTHERN CASCADES NORTH OF CRATER LAKE, SO THERE`S A
CHANCE FOR SCATTERED STORMS THERE.
NOT MUCH CHANGE IN THE PATTERN IS EXPECTED TUESDAY NIGHT THROUGH
WEDNESDAY. THE UPPER LOW WILL REMAIN NEARLY STATIONARY, THEN SLOWLY
MOVE NORTHWARD WEDNESDAY AFTERNOON AS THE UPSTREAM UPPER TROUGH
MOVES TOWARDS WESTERN B.C. THE MODELS PUT THE GREATEST INSTABILITY
ALONG THE CASCADES AND WESTERN SISKIYOU COUNTY TUESDAY NIGHT, THEN
BECOMING MORE STABLE ON WEDNESDAY, THEREFORE THE CONCERN FOR
NOCTURNAL STORMS EXIST AGAIN TUESDAY NIGHT, THEN THE THREAT OF
STORMS SHIFTS NORTH WEDNESDAY.
THE UPPER LOW WILL MOVE INLAND AND ACROSS THE AREA THURSDAY
AFTERNOON AND WE EXPECT A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS
ALONG WITH A BRIEF COOL DOWN. THE UPPER LOW WILL FINALLY KICK
NORTHEAST OF THE AREA FRIDAY AFTERNOON AND A WEAK TROUGH REMAINS,
BUT IT WILL STAY DRY WITH MILDER TEMPERATURES.
WINDS WILL BE ANOTHER CONCERN, PARTICULARLY OVER THE HIGHER TERRAIN
ALONG AND EAST OF THE CASCADES THIS AFTERNOON THROUGH AT LEAST
THURSDAY AFTERNOON. ALSO WINDS ARE ALIGNED UP PRETTY WELL IN THE
SHASTA VALLEY WITH 700MB WINDS BETWEEN 25-35 KTS, SOME OF WHICH
COULD MIX DOWN NEAR THE SURFACE. THE MODEL GUIDANCE SHOWS WIND GUSTS
BETWEEN 45-50 KTS, BUT SUSPECT THIS MAY BE A BIT OVERDONE. THIS IS
BECAUSE THE PRESSURE GRADIENT IS NOT STRONG LIKE WE TYPICALLY SEE IN
THE WINTER THAT WOULD PRODUCE WIND GUST OF THIS MAGNITUDE. SO WHILE
WE EXPECT WINDS TO INCREASE AROUND THE WEED AREA, THEY WON`T BE
ENOUGH TO REACH ADVISORY CRITERIA.
A THERMAL TROUGH WILL DEVELOP ALONG THE COAST FRIDAY NIGHT THROUGH
SATURDAY WITH INCREASING OFFSHORE FLOW. THE PATTERN THAT IS SETTING
UP IS FAVORABLE FOR A CHETCO EFFECT AND THE HIGH TEMPERATURES IN
BROOKINGS COULD EASILY GET INTO THE MID TO UPPER 80S OR LOW 90S.
MEANWHILE TEMPERATURES WILL HEAT UP IN THE WEST SIDE VALLEYS WITH
READINGS IN THE LOWER TO MID 90S. DRY CONDITIONS CONTINUE SUNDAY AND
THE THERMAL TROUGH WILL SHIFT INLAND OVER THE WEST SIDE VALLEYS WITH
TEMPERATURES EXPECTED TO BE IN THE MID 90S.
KEEP IN MIND WHILE THE MODELS REMAIN IN GOOD AGREEMENT WITH THE
OVERALL PATTERN THE NEXT FEW DAYS, THE MAIN CHALLENGE WILL BE
ADDRESSING THE DETAILS OF THE WEATHER, ESPECIALLY AS IT RELATES TO
THUNDERSTORM COVERAGE, SHOWERS AND PATCHY TO AREAS OF SMOKE.
CONFIDENCE REMAINS LOW REGARDING THE MOST FAVORABLE AREAS FOR
THUNDERSTORMS. THEREFORE DETAILS ON THIS COULD CHANGE FROM ONE DAY
TO THE NEXT SO STAY TUNED FOR THE LATEST UPDATES. -PETRUCELLI
&&
.AVIATION...FOR THE 10/18Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE THIS EVENING...THEN PERSIST
THROUGH MID-MORNING TUESDAY. INLAND...VFR CONDITIONS WILL
PREVAIL THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN
SMOKE. ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON WITH THE GREATER COVERAGE OVER THE CASCADES AND SISKIYOUS.
ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE INTO THE MORNING
WEST OF THE CASCADES. STORMS MAY BRING ERRATIC AND GUSTY WINDS AND
LOCAL OBSCURATION OF HIGHER TERRAIN.
&&
.MARINE...UPDATED 230 PM PDT MONDAY 10 AUGUST 2015...A WEAK
SURFACE PRESSURE PATTERN WILL RESULT IN CALM WINDS AND SEAS OVER
THE NEXT SEVERAL DAYS, ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD
BRING A FEW THUNDERSTORMS TO THE COASTAL WATERS TONIGHT INTO EARLY
TUESDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE COAST FRIDAY AND
SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND CHOPPY SEAS,
ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO. ALTHOUGH
STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY STEEP
SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -BPN
&&
.FIRE WEATHER...UPDATED 230 PM PDT MONDAY 10 AUGUST 2015...SOUTHERLY
FLOW INCREASED TODAY...AND SO DID CLOUD COVER. THIS IS INHIBITING
THUNDERSTORM DEVELOPMENT OVER THE AREA...BUT SOME ARE STILL EXPECTED
TO DEVELOP. SCATTERED COVERAGE WILL EVENTUALLY DEVELOP OVER THE
CASCADES WITH ISOLATED COVERAGE OVER MOST OF THE OTHER INLAND AREAS.
ISOLATED THUNDERSTORMS MAY PERSIST THROUGH THE NIGHT...THEN BECOME
SCATTERED AGAIN OVER THE NORTHERN CASCADES TUESDAY AFTERNOON. GUSTY
SOUTH WINDS HAVE ALREADY DEVELOPED AND WILL CONTINUE THROUGH
THURSDAY...WHEN IT MAY BE ESPECIALLY WINDY ON THE EAST SIDE DUE TO
AN UPPER LEVEL TROUGH MOVING ONSHORE. AFTER THE TROUGH MOVES INLAND
...OFFSHORE LOW LEVEL FLOW WILL DEVELOP OVER THE COAST RANGE FRIDAY
NIGHT INTO SATURDAY NIGHT.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR
ORZ616-617-622>624.
RED FLAG WARNING FROM 5 PM TO 11 PM PDT TUESDAY FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM TO 8 PM PDT TUESDAY FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
957 AM PDT MON AUG 10 2015
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS A BAND OF CLOUDS MOVING
NORTH IN ASSOCIATION WITH A SHORTWAVE IN EASTERN KLAMATH AND LAKE
COUNTY. RETURNS FROM THIS FEATURE HAVE BEEN WEAK AND THERE HAVE
BEEN NO REPORTS OF ANY RAINFALL. ALSO NO LIGHTING STRIKES HAVE
BEEN OBSERVED IN OUR FORECAST AREA. THUS HAVE REMOVED POPS AND
THUNDER FROM THE FORECAST IN THESE AREAS. THE WATER VAPOR IMAGE
SHOWS THE UPPER LOW MARCHING SOUTH ALONG 130 W. IT`S ALSO PICKING
UP ON A WEAK SHORTWAVE MOVING INTO NORTHWEST CALIFORNIA AND THIS
WILL MOVE NORTHEAST.
LOOKING AT DATA THIS MORNING WOULD SUGGEST THE BEST CHANCE FOR
SCATTERED THUNDERSTORMS WILL BE LATE THIS AFTERNOON AND EVENING
AND MOST CENTERED OVER THE CASCADES, SISKIYOUS AND WESTERN
SIKSYOU COUNTY. THE MODELS SHOW THE LOWEST LI`S AND HIGHEST
BOUNDARY LAYER CAPE VALUES AND THETA E CONVERGENCE IN THESE AREAS
LATE THIS AFTERNOON. IN ADDITION THE 700 MB WINDS AND THE
700-500MB WINDS ARE FROM THE SOUTH THROUGH EARLY THIS AFTERNOON,
THEN SHIFT EVER SO SLIGHTLY TO THE SOUTH TO SOUTHWEST LATE THIS
AFTERNOON AND EVENING. THEREFORE WE THINK THE MAJORITY OF
THUNDERSTORMS WILL REMAIN IN THESE AREAS LATE THIS AFTERNOON AND
EVENING. HOWEVER WINDS ALOFT WILL BE STRONGER, THEREFORE STORMS
THAT FORM OVER WESTERN SIKSYOU COUNTY AND SISKIYOU MOUNTAINS WILL
GET CARRIED NORTH INTO THE WEST SIDE VALLEYS, BUT THEY WILL BE
RUNNING IN AN ENVIRONMENT THAT IS LESS UNSTABLE AND ALSO WITH
LESS MID LEVEL MOISTURE. ALSO STORMS THAT FORM OVER THE CASCADES
COULD GET PULLED SLIGHTLY WESTWARD AND SCATTERED STORMS ARE
POSSIBLE ALONG THE FOOTHILLS OF THE CASCADES IN EASTERN DOUGLAS
COUNTY.
OF NOTE THE HIGH RES HRRR MODEL SHOWS VERY LITTLE ACTIVITY FROM
THE CASCADES WEST. IT ACTUALLY SHOWS A FRONTAL BOUNDARY ARRIVING
AT THE COAST BY THIS EVENING USHERING MORE STABLE CONDITIONS
BRINGING LIGHT RAIN WITH MOST OF THE CONVECTION IN MODOC AND LAKE
COUNTY. NOT SURE IF THIS IS CORRECT, BUT IT MAY BE ON TO SOMETHING
GIVEN THE BAND OF CLOUDS JUST OFF THE COAST WHICH WILL PUSH
INLAND LATER THIS AFTERNOON.
FOR TONIGHT, THE MODELS ARE IN FRIARLY GOOD AGREEMENT SHOWING
WINDS AT 700 AND 700-500MB REMAIN SOUTH TO SOUTHWEST. THE NAM
SHOWS MORE OF A SOUTHEAST COMPONENT OVERNIGHT TONIGHT, BUT THE
GFS DOES NOT. THE NAM SHOWS LIFTED INDICES (LI`S) LOWERING TO
AROUND -5 C ALONG THE COOS/DOUGLAS COUNTY LINE, BUT SUSPECT THAT
MAY BE OVERDONE. IN CONTRAST THE GFS SHOWS LI`S AROUND -1C. THE
NAM CONTINUES TO SHOW A SHORTWAVE MOVING WEST OF THE CASCADES
OVERNIGHT TONIGHT, BUT THE GFS IS MUCH WEAKER. BECAUSE OF THE
ABOVE MENTIONED REASONS, WE THINK THUNDERSTORMS WILL BE ISOLATED
WEST OF THE CASCADES. -PETRUCELLI
&&
.AVIATION...FOR THE 10/12Z TAF CYCLE...ALONG THE COAST...MVFR TO
IFR CIGS ARE LINGERING MAINLY NORTH OF CAPE BLANCO THIS MORNING,
BUT EXPECT THAT THIS WILL BURN BACK OFFSHORE BY LATE MORNING WITH
VFR CONDITIONS EXPECTED TO LAST INTO TONIGHT. INLAND...VFR
CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS. HOWEVER
THUNDERSTORMS WILL BE A CONCERN AFTER 21Z AND THEY COULD BRING
ERRATIC AND GUSTY WINDS. -PETRUCELLI
&&
.MARINE...UPDATED 830 AM PDT MONDAY 10 AUGUST 2015...A WEAK
SURFACE PRESSURE PATTERN WILL PREVAIL THROUGH THURSDAY NIGHT WITH
OCCASIONALSHOWERS. WINDS WILL BE 10 KT OR LESS AND SEAS LESS THAN 4
FEET THROUGH THURSDAY NIGHT. AN UPPER LEVEL DISTURBANCE WILL ALSO
BRING A SLIGHT CHANCE FOR THUNDERSTORMS TO THE COASTAL WATERS MONDAY
NIGHT INTO EARLY TUESDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY...BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS...STRONGEST IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
&&
.FIRE WEATHER...UPDATED 345 AM PDT MONDAY 10 AUGUST 2015...SOUTHERLY
FLOW INCREASES TODAY...BRINGING MONSOONAL MOISTURE TO THE AREA ALONG
WITH MODERATE TO STRONG SOUTHERLY TO SOUTHWESTERLY
WINDS...ESPECIALLY OVER THE RIDGES AND OCCASIONALLY IN NORTH TO
SOUTH ORIENTED VALLEYS SUCH AS THE SHASTA VALLEY. THUNDERSTORMS WILL
DEVELOP...AFTER A WEAK SHORT WAVE BRINGS CLOUDS AN