Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/13/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
900 PM MST THU JUL 10 2014
.SYNOPSIS...STORM COVERAGE AND INTENSITY SHOULD INCREASE THIS
WEEKEND AS AN UPPER LEVEL DISTURBANCE APPROACHES THE AREA FROM THE
EAST. OTHERWISE...A CHANCE OF THUNDERSTORMS WILL CONTINUE INTO NEXT
WEEK. MOST STORMS WILL OCCUR DURING THE AFTERNOON AND EVENING HOURS
BUT SOME WILL LINGER OVERNIGHT. SOME STORMS WILL PRODUCE LOCALLY
HEAVY RAINFALL AND STRONG WINDS.
&&
.DISCUSSION...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
GREENLEE/GRAHAM/COCHISE COUNTIES WITH DRY CONDITIONS ELSEWHERE AT
THIS TIME. A LARGE MCS ENCOMPASSED NEARLY THE ERN HALF OF SONORA
MEXICO...AND THIS CONVECTIVE ACTIVITY IS ASSOCIATED WITH DIFFLUENCE
ALOFT AS PER THE 11/00Z 300 MB UPPER AIR PLOT. CLOUD TOPS WERE
GENERALLY COOLING DURING THE PAST 1-2 HOURS ACROSS NERN SONORA.
11/01Z RUC HRRR AND TO SOME EXTENT THE 11/00Z NAM DEPICT AT LEAST
ISOLATED COVERAGE OF SHOWERS/TSTMS LATER TONIGHT MOSTLY EAST AND
SOUTH OF TUCSON. HAVE NOTED THAT THE 11/01Z RUC BRINGS PRECIP ECHOES
INTO TUCSON AROUND 11Z-12Z FRIDAY. THIS SOLUTION SEEMS PLAUSIBLE
ALBEIT PERHAPS SOMEWHAT SLOW GIVEN CURRENT RADAR/SATELLITE TRENDS.
THE OFFICIAL FORECAST DEPICTS DECREASING POPS ACROSS MUCH OF THE
AREA DURING THE NEXT FEW HOURS. HOWEVER...HAVE MAINTAINED A SLIGHT
CHANCE OF SHOWERS/TSTMS LATE TONIGHT FROM TUCSON EWD/SWD.
PRECIP-FREE CONDITIONS SHOULD OCCUR ACROSS WRN PIMA COUNTY. 11/00Z
NAM SUGGESTS THAT COVERAGE OF SHOWERS/TSTMS SHOULD INCREASE FRI
VERSUS THIS AFTERNOON/EVE. THE FAVORED AREA FOR SHOWERS/TSTMS FRI
AFTERNOON WILL BE EAST AND SOUTH OF TUCSON...WITH ISOLATED
SHOWERS/TSTMS TO OCCUR WEST-TO-NORTHWEST OF TUCSON. HIGH TEMPS FRI
WILL BE NEARLY IDENTICAL TO TEMPS ACHIEVED THIS AFTERNOON.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 12/06Z.
ISOLATED -TSRA/-SHRA MOSTLY EAST AND SOUTH OF KTUS THE REST OF
TONIGHT. THE BULK OF THESE SHOWERS/THUNDERSTORMS SHOULD END AROUND
DAYBREAK FRIDAY. EXPECT SCATTERED TSRA/SHRA FROM KTUS EASTWARD AND
SOUTHWARD FRIDAY AFTERNOON AND FRIDAY EVENING...WITH A LESSER CHANCE
OF SHOWERS/THUNDERSTORMS NORTHWEST OF KTUS. MVFR VISIBILITIES WILL
OCCUR WITH +TSRA...AS WELL AS WIND GUSTS MOSTLY AROUND 35-40 KTS.
OTHERWISE...CLOUD DECKS WILL BE AROUND 8-15K FT AGL. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE WILL REMAIN SUFFICIENT TO PROVIDE SCATTERED
TO PERHAPS NUMEROUS MAINLY AFTERNOON AND EVENING THUNDERSTORMS INTO
NEXT WEEK.
&&
.PREV DISCUSSION...WE SHOULD SEE A SIMILAR THREAT FOR SHOWERS AND
THUNDERSTORMS ON FRIDAY...BUT BY THIS WEEKEND AN EASTERLY WAVE
CURRENTLY OVER THE STATE OF COAHUILA MEXICO...WHICH IS JUST SOUTH OF
SOUTHWESTERN TEXAS...WILL MAKE ITS WAY THOUGH NORTHWEST MEXICO THIS
WEEKEND AND EARLY NEXT WEEK. THIS SYSTEM IS EXPECTED TO BRING AN
ENHANCED RISK FOR SHOWERS AND THUNDERSTORMS BEGINNING SATURDAY...BUT
ESPECIALLY SUNDAY INTO MONDAY. I INCREASED THE POP FORECAST AT BIT
FOR SATURDAY THROUGH MONDAY...BUT ESPECIALLY SATURDAY NIGHT AND
SUNDAY NIGHT FOR THE FAR WESTERN DESERTS NEAR AJO AND ORGAN PIPE FOR
THE POTENTIAL OF SEEING A THREAT FOR THUNDERSTORMS WELL INTO THE
NIGHT AS EASTERLY FLOW NORTH OF THE WAVE HELPS TO PUSH STORMS THAT
DEVELOP OVER EASTERN ZONES INTO THE LOWER DESERTS. ONCE THE EASTERLY
WAVE MOVES ACROSS NORTHERN BAJA AND THE NORTHERN GULF OF
CALIFORNIA...EXPECT CONVECTIVE ACTIVITY TO DROP DOWN TO ISOLATED
OVER THE WESTERN ZONES AND SCATTERED OVER THE EAST.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
PREV DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
909 AM PDT FRI JUL 11 2014
.UPDATE...
WE MADE A SMALL ADJUSTMENT TO INCLUDE THE RENO-CARSON VICINITY,
SUSANVILLE AND HAWTHORNE IN THE ISOLATED THUNDERSTORM AREA THIS
AFTERNOON. THIS CHANGE WILL BE MOST NOTABLE FOR THE WEB PAGE SO
THAT THESE CITY CENTERS WILL BE INCLUDED IN THE THUNDERSTORM
THREAT. MOIST AND UNSTABLE CONDITIONS ARE LIKELY TO CONTINUE
THROUGH THIS AFTERNOON WITH THE WEST WINDS LATER TODAY NOT
BRINGING MUCH DRYING. IN ADDITION, THE CAPPING INVERSION BETWEEN
400-450 MB ON THE RENO 12Z SOUNDING WHICH MAY HAVE LIMITED
LIGHTNING ACTIVITY OVERNIGHT IS PROJECTED TO ERODE BY MID
AFTERNOON.
THE 12Z NAM AND EARLY MORNING HRRR RUNS BROUGHT ISOLATED CONVECTION
EVEN FARTHER WEST TO A PORTION OF THE SIERRA ZONES, BUT CONFIDENCE
IS MARGINAL SINCE BETTER LOW LEVEL CONVERGENCE SHOULD BE EAST OF
THE TAHOE BASIN AND NORTHERN MONO COUNTY BY THE TIME WE REACH PEAK
HEATING. MJD
&&
.PREVIOUS DISCUSSION... /ISSUED 620 AM PDT FRI JUL 11 2014/
UPDATE...
UPDATING TO REMOVE THUNDERSTORMS FROM THIS MORNING. INSTABILITY
HAS BEEN WEAK OVERNIGHT WITH ONLY SHOWERS ACROSS NORTHEAST
CALIFORNIA AND NORTHWEST NEVADA. EXPECT THIS TREND TO CONTINUE
THROUGH THE MORNING WITH ONLY SHOWERS. OTHERWISE, NO CHANGES AS
SOLAR HEATING SHOULD RESULT IN ISOLATED SHOWERS AND STORMS THIS
AFTERNOON FOCUSED NORTH OF I-80. WALLMANN
FIRE WEATHER...
WITH INSTABILITY WEAKER THAN EXPECTED OVERNIGHT, ONLY LIGHT
SHOWERS FORMED. LIGHTNING WAS LIMITED TO A FEW ISOLATED STRIKES
WEST OF THE CREST. WITH THIS TREND TO CONTINUE THROUGH THE
MORNING, HAVE CANCELED THE RED FLAG WARNING. ISOLATED
THUNDERSTORMS ARE EXPECTED TO FORM LATER TODAY, BUT WITH THE
MOISTURE IN PLACE EXCEPT THEM TO BE MOSTLY WET. WALLMANN
PREVIOUS DISCUSSION... /ISSUED 311 AM PDT FRI JUL 11 2014/
SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS FOR THE SIERRA AND WESTERN
NEVADA MAY CONTINUE NORTH OF SUSANVILLE AND GERLACH THIS MORNING.
ANOTHER ROUND OF STORMS IS POSSIBLE FROM NEAR INTERSTATE 80 NORTH
THIS AFTERNOON BEFORE HIGH PRESSURE STRENGTHENS OVER THE WEEKEND
FOR DRIER AND HOTTER CONDITIONS.
SHORT TERM...
EXPANDED COVERAGE OF THUNDERSTORMS SLIGHTLY FURTHER SOUTH FOR THIS
AFTERNOON AND EVENING. NO OTHER MAJOR CHANGES TO THE SHORT TERM
FORECAST.
AS OF 3 AM, WEAK ISOLATED-SCATTERED SHOWERS WERE MOVING NORTHWEST
ACROSS NORTHEASTERN CALIFORNIA AND NORTHWEST NEVADA MAINLY NORTH OF
HIGHWAY 50. WATER VAPOR IMAGERY ALSO SHOWED THE NEGATIVELY-TILTED
TROUGH JUST OFF THE CALIFORNIA COAST AND ITS ASSOCIATED JET
PUSHING INTO NORTHERN CALIFORNIA THIS MORNING. ISOLATED
THUNDERSTORMS AND LIGHTNING HAVE ALREADY BEGUN TO AFFECT AREAS
WEST OF THE CREST NEAR GRASS VALLEY AND REDDING EARLY THIS
MORNING. THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD AS
FORCING/INSTABILITY PUSHES IN WITH THE TROUGH THROUGH THE MORNING.
FORECAST MODELS AND HIGH RESOLUTION FORECASTS (HRRR) STILL
INDICATING THAT THE BEST FORCING WILL FOCUS WEST OF THE SIERRA AND
ACROSS FAR NORTHERN CALIFORNIA AND SOUTHERN OREGON. WITH THE
POTENTIAL FOR ELEVATED CONVECTION ACROSS NORTHEASTERN CALIFORNIA
AND NORTHWEST NEVADA, DRY LIGHTNING AND POSSIBLE FIRE STARTS IS A
CONCERN. CHECK OUT THE FIRE WEATHER DISCUSSION FOR MORE DETAILS.
THE MAIN UPPER FORCING/JET NOSE SLIDES INTO EXTREME NORTHERN
NEVADA AND SOUTHEAST OREGON BETWEEN MID MORNING AND EARLY
AFTERNOON TODAY. WITH THE SLOWER TIMING OF THE INCOMING TROUGH AND
ITS UPPER LEVEL FORCING, WENT AHEAD AND SPREAD THE POTENTIAL FOR
ISOLATED THUNDERSTORMS FURTHER SOUTH FOR THIS AFTERNOON/EVENING.
THUNDERSTORMS WILL LIKELY FORM ALONG THE SIERRA AND THEN BE PUSHED
EASTWARD BY THE ZEPHYR WINDS IN THE AFTERNOON. KEPT THUNDERSTORMS
OUT OF TAHOE AND THE SIERRA FOR THIS REASON. OTHERWISE, INCREASING
SOUTHWEST FLOW ALOFT THROUGH THE DAY WILL GRADUALLY STABILIZE AND
DRY OUT THE ATMOSPHERE BY THE EVENING.
DRIER AND MORE STABLE AIR REALLY INVADES THE EASTERN SIERRA AND
WESTERN NEVADA BY SATURDAY AS THE FOUR CORNERS RIDGE BEGINS TO BUILD
WESTWARD INTO CALIFORNIA AND NEVADA. DAYTIME HIGHS ON SATURDAY WILL
BE NEAR OR SLIGHTLY ABOVE AVERAGE, BUT EXPECT TO SEE A SIGNIFICANT
WARMUP INTO NEXT WEEK. ELW
LONG TERM...MONDAY THROUGH THURSDAY...
HIGH PRESSURE REMAINS OVER NEVADA NEXT WEEK WITH A DAILY THREAT OF
THUNDERSTORMS ALONG WITH ABOVE AVERAGE TEMPERATURES. THE MODELS,
ESPECIALLY THE GFS AND EC, REMAIN IN VERY GOOD AGREEMENT ON THIS.
GFS/EC NOW IN BETTER AGREEMENT WITH SOME MID-LEVEL COOLING WITH MORE
INSTABILITY MONDAY ALONG AND JUST EAST OF THE SIERRA CREST. WITH
MOISTURE STILL IN PLACE FROM THIS WEEK`S EVENT, THUNDERSTORMS ARE
POSSIBLE IN THIS AREA. TEMPERATURES WILL REMAIN HOT AND INTO THE
TRIPLE DIGITS IN WESTERN NEVADA AND 80S TO LOW 90S SIERRA. WITH THIS
BEING THE FIRST THUNDERSTORM DAY, A MIX OF WET AND DRY ARE POSSIBLE
WITH PW AROUND 0.8 INCHES. MONDAY WOULD BE THE BIGGEST CONCERN FOR
FIRE WEATHER.
ON TUESDAY INTO WEDNESDAY, THE HIGH SHIFTS A BIT FURTHER EAST INTO
EASTERN NEVADA WITH MOISTURE STREAMING UP FROM THE MONSOON. EXPECT
COVERAGE OF STORMS TO INCREASE WITH THE BEST DAY FOR STORMS LIKELY
WEDNESDAY. DAYTIME TEMPS WILL LIKELY SEE A COOLING TREND DUE TO
INCREASED CLOUD COVER.
ON THURSDAY, IT APPEARS A WEAK TROUGH WILL BEGIN TO MOVE INTO THE
PACNW CREATING A LIGHT SW FLOW. THIS SHOULD START A DRYING TREND SO
BEGAN TO TREND THE THREAT OF STORMS DOWNWARD. WALLMANN
AVIATION...
ISOLATED THUNDERSTORMS REMAIN POSSIBLE THIS MORNING, MAINLY NORTH OF
LAKE TAHOE INTO LASSEN COUNTY. BKN-OVC CIGS TO REMAIN NEAR 10 KFT.
THIS AFTERNOON, EXPECT MORE SHOWERS AND STORMS TO BE CONCENTRATED
NORTH OF I-80 WITH SFC WND GUSTS TO 40 KTS THE PRIMARY THREAT.
AFTERNOON SW WINDS ALSO LIKELY INTO THE RENO-TAHOE TERMINALS THIS
AFTERNOON WITH PEAK GUSTS 25 KTS 22-03Z. THIS WEEKEND LOOKS DRY WITH
THE NEXT THREAT OF THUNDERSTORMS NEXT WEEK. WALLMANN
FIRE WEATHER...
THIS MORNING, GOOD INSTABILITY ALOFT, STEEP UPPER LEVEL LAPSE RATES,
AND FORCING FROM THE MID AND UPPER-LEVEL WAVE WILL CONTINUE THE
THREAT FOR ELEVATED THUNDERSTORMS. STORMS WILL BE A MIX OF
WET AND DRY, AS PRECIPITABLE WATER INCREASES TO OVER 0.80". BUT AS
THE WAVE PUSHES INLAND, THE MIDLEVEL STEERING FLOW WILL INCREASE TO
OVER 30KTS. THIS INCREASED STORM SPEED WILL ALLOW FOR LESS RAINFALL
OVERALL AND HIGHER POTENTIAL FOR DRY LIGHTNING STRIKES. RED FLAG
WARNING IS IN EFFECT THROUGH 11 AM THIS MORNING FOR AREAS NORTH OF
TAHOE IN NORTHEASTERN CALIFORNIA AND THE NORTHEAST SIERRA. IT
STILL APPEARS THE BRUNT OF THE STORMS WILL REMAIN WEST OF THE
CREST THIS MORNING. SO FAR, LIGHTNING HAS BEEN LIMITED TO AROUND
LAKE OROVILLE. LATEST HRRR SHOWS STORMS TO INCREASE A BIT MORE
AFTER SUNRISE SO WILL LEAVE FORECAST ALONE FOR NOW.
THIS AFTERNOON CONVECTION WILL AGAIN DEVELOP IN NORTHWEST NEVADA
AND NORTHEAST CA. THESE STORMS WILL BE A MIX OF WET AND DRY STORMS
AS WELL, AS MID LEVEL FLOW REMAINS STRONGER.
THE NEXT THREAT FOR THUNDERSTORMS WILL BE MONDAY UNDER THE STRONG
RIDGE AND VERY HOT TEMPERATURES. THAT WILL BE THE BEST DAY FOR DRY
LIGHTNING DUE TO THE VERY HOT TEMPERATURES. BY TUESDAY/WEDNESDAY
MOISTURE WILL INCREASE WITH THE STORMS WET AND LOCALLY HEAVY RAINS
POSSIBLE. HOON/WALLMANN
&&
.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 RENO NV
620 AM PDT FRI JUL 11 2014
.UPDATE...
UPDATING TO REMOVE THUNDERSTORMS FROM THIS MORNING. INSTABILITY
HAS BEEN WEAK OVERNIGHT WITH ONLY SHOWERS ACROSS NORTHEAST
CALIFORNIA AND NORTHWEST NEVADA. EXPECT THIS TREND TO CONTINUE
THROUGH THE MORNING WITH ONLY SHOWERS. OTHERWISE, NO CHANGES AS
SOLAR HEATING SHOULD RESULT IN ISOLATED SHOWERS AND STORMS THIS
AFTERNOON FOCUSED NORTH OF I-80. WALLMANN
&&
.FIRE WEATHER...
WITH INSTABILITY WEAKER THAN EXPECTED OVERNIGHT, ONLY LIGHT
SHOWERS FORMED. LIGHTNING WAS LIMITED TO A FEW ISOLATED STRIKES
WEST OF THE CREST. WITH THIS TREND TO CONTINUE THROUGH THE
MORNING, HAVE CANCELED THE RED FLAG WARNING. ISOLATED
THUNDERSTORMS ARE EXPECTED TO FORM LATER TODAY, BUT WITH THE
MOISTURE IN PLACE EXCEPT THEM TO BE MOSTLY WET. WALLMANN
&&
.PREVIOUS DISCUSSION... /ISSUED 311 AM PDT FRI JUL 11 2014/
SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS FOR THE SIERRA AND WESTERN
NEVADA MAY CONTINUE NORTH OF SUSANVILLE AND GERLACH THIS MORNING.
ANOTHER ROUND OF STORMS IS POSSIBLE FROM NEAR INTERSTATE 80 NORTH
THIS AFTERNOON BEFORE HIGH PRESSURE STRENGTHENS OVER THE WEEKEND
FOR DRIER AND HOTTER CONDITIONS.
SHORT TERM...
EXPANDED COVERAGE OF THUNDERSTORMS SLIGHTLY FURTHER SOUTH FOR THIS
AFTERNOON AND EVENING. NO OTHER MAJOR CHANGES TO THE SHORT TERM
FORECAST.
AS OF 3 AM, WEAK ISOLATED-SCATTERED SHOWERS WERE MOVING NORTHWEST
ACROSS NORTHEASTERN CALIFORNIA AND NORTHWEST NEVADA MAINLY NORTH OF
HIGHWAY 50. WATER VAPOR IMAGERY ALSO SHOWED THE NEGATIVELY-TILTED
TROUGH JUST OFF THE CALIFORNIA COAST AND ITS ASSOCIATED JET
PUSHING INTO NORTHERN CALIFORNIA THIS MORNING. ISOLATED
THUNDERSTORMS AND LIGHTNING HAVE ALREADY BEGUN TO AFFECT AREAS
WEST OF THE CREST NEAR GRASS VALLEY AND REDDING EARLY THIS
MORNING. THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD AS
FORCING/INSTABILITY PUSHES IN WITH THE TROUGH THROUGH THE MORNING.
FORECAST MODELS AND HIGH RESOLUTION FORECASTS (HRRR) STILL
INDICATING THAT THE BEST FORCING WILL FOCUS WEST OF THE SIERRA AND
ACROSS FAR NORTHERN CALIFORNIA AND SOUTHERN OREGON. WITH THE
POTENTIAL FOR ELEVATED CONVECTION ACROSS NORTHEASTERN CALIFORNIA
AND NORTHWEST NEVADA, DRY LIGHTNING AND POSSIBLE FIRE STARTS IS A
CONCERN. CHECK OUT THE FIRE WEATHER DISCUSSION FOR MORE DETAILS.
THE MAIN UPPER FORCING/JET NOSE SLIDES INTO EXTREME NORTHERN
NEVADA AND SOUTHEAST OREGON BETWEEN MID MORNING AND EARLY
AFTERNOON TODAY. WITH THE SLOWER TIMING OF THE INCOMING TROUGH AND
ITS UPPER LEVEL FORCING, WENT AHEAD AND SPREAD THE POTENTIAL FOR
ISOLATED THUNDERSTORMS FURTHER SOUTH FOR THIS AFTERNOON/EVENING.
THUNDERSTORMS WILL LIKELY FORM ALONG THE SIERRA AND THEN BE PUSHED
EASTWARD BY THE ZEPHYR WINDS IN THE AFTERNOON. KEPT THUNDERSTORMS
OUT OF TAHOE AND THE SIERRA FOR THIS REASON. OTHERWISE, INCREASING
SOUTHWEST FLOW ALOFT THROUGH THE DAY WILL GRADUALLY STABILIZE AND
DRY OUT THE ATMOSPHERE BY THE EVENING.
DRIER AND MORE STABLE AIR REALLY INVADES THE EASTERN SIERRA AND
WESTERN NEVADA BY SATURDAY AS THE FOUR CORNERS RIDGE BEGINS TO BUILD
WESTWARD INTO CALIFORNIA AND NEVADA. DAYTIME HIGHS ON SATURDAY WILL
BE NEAR OR SLIGHTLY ABOVE AVERAGE, BUT EXPECT TO SEE A SIGNIFICANT
WARMUP INTO NEXT WEEK. ELW
LONG TERM...MONDAY THROUGH THURSDAY...
HIGH PRESSURE REMAINS OVER NEVADA NEXT WEEK WITH A DAILY THREAT OF
THUNDERSTORMS ALONG WITH ABOVE AVERAGE TEMPERATURES. THE MODELS,
ESPECIALLY THE GFS AND EC, REMAIN IN VERY GOOD AGREEMENT ON THIS.
GFS/EC NOW IN BETTER AGREEMENT WITH SOME MID-LEVEL COOLING WITH MORE
INSTABILITY MONDAY ALONG AND JUST EAST OF THE SIERRA CREST. WITH
MOISTURE STILL IN PLACE FROM THIS WEEK`S EVENT, THUNDERSTORMS ARE
POSSIBLE IN THIS AREA. TEMPERATURES WILL REMAIN HOT AND INTO THE
TRIPLE DIGITS IN WESTERN NEVADA AND 80S TO LOW 90S SIERRA. WITH THIS
BEING THE FIRST THUNDERSTORM DAY, A MIX OF WET AND DRY ARE POSSIBLE
WITH PW AROUND 0.8 INCHES. MONDAY WOULD BE THE BIGGEST CONCERN FOR
FIRE WEATHER.
ON TUESDAY INTO WEDNESDAY, THE HIGH SHIFTS A BIT FURTHER EAST INTO
EASTERN NEVADA WITH MOISTURE STREAMING UP FROM THE MONSOON. EXPECT
COVERAGE OF STORMS TO INCREASE WITH THE BEST DAY FOR STORMS LIKELY
WEDNESDAY. DAYTIME TEMPS WILL LIKELY SEE A COOLING TREND DUE TO
INCREASED CLOUD COVER.
ON THURSDAY, IT APPEARS A WEAK TROUGH WILL BEGIN TO MOVE INTO THE
PACNW CREATING A LIGHT SW FLOW. THIS SHOULD START A DRYING TREND SO
BEGAN TO TREND THE THREAT OF STORMS DOWNWARD. WALLMANN
AVIATION...
ISOLATED THUNDERSTORMS REMAIN POSSIBLE THIS MORNING, MAINLY NORTH OF
LAKE TAHOE INTO LASSEN COUNTY. BKN-OVC CIGS TO REMAIN NEAR 10 KFT.
THIS AFTERNOON, EXPECT MORE SHOWERS AND STORMS TO BE CONCENTRATED
NORTH OF I-80 WITH SFC WND GUSTS TO 40 KTS THE PRIMARY THREAT.
AFTERNOON SW WINDS ALSO LIKELY INTO THE RENO-TAHOE TERMINALS THIS
AFTERNOON WITH PEAK GUSTS 25 KTS 22-03Z. THIS WEEKEND LOOKS DRY WITH
THE NEXT THREAT OF THUNDERSTORMS NEXT WEEK. WALLMANN
FIRE WEATHER...
THIS MORNING, GOOD INSTABILITY ALOFT, STEEP UPPER LEVEL LAPSE RATES,
AND FORCING FROM THE MID AND UPPER-LEVEL WAVE WILL CONTINUE THE
THREAT FOR ELEVATED THUNDERSTORMS. STORMS WILL BE A MIX OF
WET AND DRY, AS PRECIPITABLE WATER INCREASES TO OVER 0.80". BUT AS
THE WAVE PUSHES INLAND, THE MIDLEVEL STEERING FLOW WILL INCREASE TO
OVER 30KTS. THIS INCREASED STORM SPEED WILL ALLOW FOR LESS RAINFALL
OVERALL AND HIGHER POTENTIAL FOR DRY LIGHTNING STRIKES. RED FLAG
WARNING IS IN EFFECT THROUGH 11 AM THIS MORNING FOR AREAS NORTH OF
TAHOE IN NORTHEASTERN CALIFORNIA AND THE NORTHEAST SIERRA. IT
STILL APPEARS THE BRUNT OF THE STORMS WILL REMAIN WEST OF THE
CREST THIS MORNING. SO FAR, LIGHTNING HAS BEEN LIMITED TO AROUND
LAKE OROVILLE. LATEST HRRR SHOWS STORMS TO INCREASE A BIT MORE
AFTER SUNRISE SO WILL LEAVE FORECAST ALONE FOR NOW.
THIS AFTERNOON CONVECTION WILL AGAIN DEVELOP IN NORTHWEST NEVADA
AND NORTHEAST CA. THESE STORMS WILL BE A MIX OF WET AND DRY STORMS
AS WELL, AS MID LEVEL FLOW REMAINS STRONGER.
THE NEXT THREAT FOR THUNDERSTORMS WILL BE MONDAY UNDER THE STRONG
RIDGE AND VERY HOT TEMPERATURES. THAT WILL BE THE BEST DAY FOR DRY
LIGHTNING DUE TO THE VERY HOT TEMPERATURES. BY TUESDAY/WEDNESDAY
MOISTURE WILL INCREASE WITH THE STORMS WET AND LOCALLY HEAVY RAINS
POSSIBLE. HOON/WALLMANN
&&
.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 RENO NV
311 AM PDT FRI JUL 11 2014
.SYNOPSIS...
ISOLATED TO SCATTERED THUNDERSTORMS FOR THE SIERRA AND WESTERN
NEVADA MAY CONTINUE NORTH OF SUSANVILLE AND GERLACH THIS MORNING.
ANOTHER ROUND OF STORMS IS POSSIBLE FROM NEAR INTERSTATE 80 NORTH
THIS AFTERNOON BEFORE HIGH PRESSURE STRENGTHENS OVER THE WEEKEND
FOR DRIER AND HOTTER CONDITIONS.
&&
.SHORT TERM...
EXPANDED COVERAGE OF THUNDERSTORMS SLIGHTLY FURTHER SOUTH FOR THIS
AFTERNOON AND EVENING. NO OTHER MAJOR CHANGES TO THE SHORT TERM
FORECAST.
AS OF 3 AM, WEAK ISOLATED-SCATTERED SHOWERS WERE MOVING NORTHWEST
ACROSS NORTHEASTERN CALIFORNIA AND NORTHWEST NEVADA MAINLY NORTH OF
HIGHWAY 50. WATER VAPOR IMAGERY ALSO SHOWED THE NEGATIVELY-TILTED
TROUGH JUST OFF THE CALIFORNIA COAST AND ITS ASSOCIATED JET
PUSHING INTO NORTHERN CALIFORNIA THIS MORNING. ISOLATED
THUNDERSTORMS AND LIGHTNING HAVE ALREADY BEGUN TO AFFECT AREAS
WEST OF THE CREST NEAR GRASS VALLEY AND REDDING EARLY THIS
MORNING. THUNDERSTORMS ARE EXPECTED TO BECOME MORE WIDESPREAD AS
FORCING/INSTABILITY PUSHES IN WITH THE TROUGH THROUGH THE MORNING.
FORECAST MODELS AND HIGH RESOLUTION FORECASTS (HRRR) STILL
INDICATING THAT THE BEST FORCING WILL FOCUS WEST OF THE SIERRA AND
ACROSS FAR NORTHERN CALIFORNIA AND SOUTHERN OREGON. WITH THE
POTENTIAL FOR ELEVATED CONVECTION ACROSS NORTHEASTERN CALIFORNIA
AND NORTHWEST NEVADA, DRY LIGHTNING AND POSSIBLE FIRE STARTS IS A
CONCERN. CHECK OUT THE FIRE WEATHER DISCUSSION FOR MORE DETAILS.
THE MAIN UPPER FORCING/JET NOSE SLIDES INTO EXTREME NORTHERN
NEVADA AND SOUTHEAST OREGON BETWEEN MID MORNING AND EARLY
AFTERNOON TODAY. WITH THE SLOWER TIMING OF THE INCOMING TROUGH AND
ITS UPPER LEVEL FORCING, WENT AHEAD AND SPREAD THE POTENTIAL FOR
ISOLATED THUNDERSTORMS FURTHER SOUTH FOR THIS AFTERNOON/EVENING.
THUNDERSTORMS WILL LIKELY FORM ALONG THE SIERRA AND THEN BE PUSHED
EASTWARD BY THE ZEPHYR WINDS IN THE AFTERNOON. KEPT THUNDERSTORMS
OUT OF TAHOE AND THE SIERRA FOR THIS REASON. OTHERWISE, INCREASING
SOUTHWEST FLOW ALOFT THROUGH THE DAY WILL GRADUALLY STABILIZE AND
DRY OUT THE ATMOSPHERE BY THE EVENING.
DRIER AND MORE STABLE AIR REALLY INVADES THE EASTERN SIERRA AND
WESTERN NEVADA BY SATURDAY AS THE FOUR CORNERS RIDGE BEGINS TO BUILD
WESTWARD INTO CALIFORNIA AND NEVADA. DAYTIME HIGHS ON SATURDAY WILL
BE NEAR OR SLIGHTLY ABOVE AVERAGE, BUT EXPECT TO SEE A SIGNIFICANT
WARMUP INTO NEXT WEEK. ELW
.LONG TERM...MONDAY THROUGH THURSDAY...
HIGH PRESSURE REMAINS OVER NEVADA NEXT WEEK WITH A DAILY THREAT OF
THUNDERSTORMS ALONG WITH ABOVE AVERAGE TEMPERATURES. THE MODELS,
ESPECIALLY THE GFS AND EC, REMAIN IN VERY GOOD AGREEMENT ON THIS.
GFS/EC NOW IN BETTER AGREEMENT WITH SOME MID-LEVEL COOLING WITH MORE
INSTABILITY MONDAY ALONG AND JUST EAST OF THE SIERRA CREST. WITH
MOISTURE STILL IN PLACE FROM THIS WEEK`S EVENT, THUNDERSTORMS ARE
POSSIBLE IN THIS AREA. TEMPERATURES WILL REMAIN HOT AND INTO THE
TRIPLE DIGITS IN WESTERN NEVADA AND 80S TO LOW 90S SIERRA. WITH THIS
BEING THE FIRST THUNDERSTORM DAY, A MIX OF WET AND DRY ARE POSSIBLE
WITH PW AROUND 0.8 INCHES. MONDAY WOULD BE THE BIGGEST CONCERN FOR
FIRE WEATHER.
ON TUESDAY INTO WEDNESDAY, THE HIGH SHIFTS A BIT FURTHER EAST INTO
EASTERN NEVADA WITH MOISTURE STREAMING UP FROM THE MONSOON. EXPECT
COVERAGE OF STORMS TO INCREASE WITH THE BEST DAY FOR STORMS LIKELY
WEDNESDAY. DAYTIME TEMPS WILL LIKELY SEE A COOLING TREND DUE TO
INCREASED CLOUD COVER.
ON THURSDAY, IT APPEARS A WEAK TROUGH WILL BEGIN TO MOVE INTO THE
PACNW CREATING A LIGHT SW FLOW. THIS SHOULD START A DRYING TREND SO
BEGAN TO TREND THE THREAT OF STORMS DOWNWARD. WALLMANN
&&
.AVIATION...
ISOLATED THUNDERSTORMS REMAIN POSSIBLE THIS MORNING, MAINLY NORTH OF
LAKE TAHOE INTO LASSEN COUNTY. BKN-OVC CIGS TO REMAIN NEAR 10 KFT.
THIS AFTERNOON, EXPECT MORE SHOWERS AND STORMS TO BE CONCENTRATED
NORTH OF I-80 WITH SFC WND GUSTS TO 40 KTS THE PRIMARY THREAT.
AFTERNOON SW WINDS ALSO LIKELY INTO THE RENO-TAHOE TERMINALS THIS
AFTERNOON WITH PEAK GUSTS 25 KTS 22-03Z. THIS WEEKEND LOOKS DRY WITH
THE NEXT THREAT OF THUNDERSTORMS NEXT WEEK. WALLMANN
&&
.FIRE WEATHER...
THIS MORNING, GOOD INSTABILITY ALOFT, STEEP UPPER LEVEL LAPSE RATES,
AND FORCING FROM THE MID AND UPPER-LEVEL WAVE WILL CONTINUE THE
THREAT FOR ELEVATED THUNDERSTORMS. STORMS WILL BE A MIX OF
WET AND DRY, AS PRECIPITABLE WATER INCREASES TO OVER 0.80". BUT AS
THE WAVE PUSHES INLAND, THE MIDLEVEL STEERING FLOW WILL INCREASE TO
OVER 30KTS. THIS INCREASED STORM SPEED WILL ALLOW FOR LESS RAINFALL
OVERALL AND HIGHER POTENTIAL FOR DRY LIGHTNING STRIKES. RED FLAG
WARNING IS IN EFFECT THROUGH 11 AM THIS MORNING FOR AREAS NORTH OF
TAHOE IN NORTHEASTERN CALIFORNIA AND THE NORTHEAST SIERRA. IT
STILL APPEARS THE BRUNT OF THE STORMS WILL REMAIN WEST OF THE
CREST THIS MORNING. SO FAR, LIGHTNING HAS BEEN LIMITED TO AROUND
LAKE OROVILLE. LATEST HRRR SHOWS STORMS TO INCREASE A BIT MORE
AFTER SUNRISE SO WILL LEAVE FORECAST ALONE FOR NOW.
THIS AFTERNOON CONVECTION WILL AGAIN DEVELOP IN NORTHWEST NEVADA
AND NORTHEAST CA. THESE STORMS WILL BE A MIX OF WET AND DRY STORMS
AS WELL, AS MID LEVEL FLOW REMAINS STRONGER.
THE NEXT THREAT FOR THUNDERSTORMS WILL BE MONDAY UNDER THE STRONG
RIDGE AND VERY HOT TEMPERATURES. THAT WILL BE THE BEST DAY FOR DRY
LIGHTNING DUE TO THE VERY HOT TEMPERATURES. BY TUESDAY/WEDNESDAY
MOISTURE WILL INCREASE WITH THE STORMS WET AND LOCALLY HEAVY RAINS
POSSIBLE. HOON/WALLMANN
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...RED FLAG WARNING UNTIL 11 AM PDT THIS MORNING CAZ271-278.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1012 PM MDT THU JUL 10 2014
.UPDATE...
ISSUED AT 1012 PM MDT THU JUL 10 2014
A WIDE BAND OF SHOWERS AND T-STORMS STRETCHED FROM EAGLE COUNTY
IN WRN COLORADO TO WELL UP ACRS SERN SOUTH DAKOTA THIS EVENING AND
HAS PRETTY MUCH REMAINED IN THIS POSITION FOR MOST OF THE DAY.
OUR CWA HAS BEEN ON THE SOUTHERN FRINGE OF THIS BAND. HAVE SEEN
LITTLE TO NO LIGHTNING ON THE PLAINS TODAY DUE IN LARGE PART TO
MARGINAL INSTABILITY AND MINIMAL CAPES. HIGH COUNTRY SAW THE BULK
OF THE CONVECTION/T-STORM ACTIVITY TODAY AND EVEN THIS EVENING
WITH THE NEXT WAVE OF STORMS NOW PASSING OVER THE GORE...PARK AND
TEN MILE RANGES. SWLY FLOW ALOFT IS EXPECTED TO CARRY THESE
STORMS ACRS NORTHERN AND CENTRAL PORTIONS OF THE FRONT RANGE IN
THE NEXT COUPLE OF HOURS SOME WEAKENING ALONG THE WAY. MEANWHILE
ON THE PLAINS...THE RAP AN HRRR INDICATE A RESURGENCE IN
SHOWER/STORM FORMATION ALONG THE WY/NE BORDERS AND ACRS THE NERN
CORNER OF THE STATE DURING THE LATE EVENING/ERLY MORNING HOURS.
GOOD SHEAR AND MOISTURE /LOW-MID 60F DEWPTS/ NOW IN PLACE ACRS
NERN WELD...MORGAN...WASHINGTON...LOGAN...SEDGWICK AND PHILLIPS
COUNTIES COULD LEAD TO THE DVLPMNT OF SHOWERS/T-STORMS IN THIS
AREA IN NEXT COUPLE OF HRS. AT THIS TIME...NOTHING GOING ON OUT
THERE...BUT OUTFLOW BNDYS FROM NEBRASKA STORMS AND A COLD FRONT
DROPPING IN FROM THE NORTH SHOULD PROVIDE THE NEEDED LIFT TO
GENERATE THIS CONVECTION...POSSIBLY AS FAR WEST AS THE DENVER
METRO AREA. COULD SEE THE BEST CHANCE FOR PRECIP ACRS NERN
COLORADO TONIGHT IN THE NEXT 2-4 HOURS. MADE ADJUSTMENTS TO THE
EVENING FORECAST PACKAGE TO REFLECT ALL OF THIS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 329 PM MDT THU JUL 10 2014
STORMS HAVE FORMED OVER THE HIGHER TERRAIN DURING THE EARLY
AFTERNOON HOURS. WESTERLY FLOW ALOFT WILL PUSH SOME OF THE STORMS
OFF THE HIGHER TERRAIN. AIRMASS OVER THE FRONT RANGE URBAN CORRIDOR
IS DRY WITH DEW POINTS IN THE MID 30S TO MID 40S RESULTING IN A 50+
TEMPERATURE/DEW POINT SPREAD. THIS WILL MAKE IT DIFFICULT FOR STORMS
TO MAINTAIN OFF THE HIGHER TERRAIN...THOUGH A FEW WILL. RAINFALL
WILL MAINLY BE LIGHT BECAUSE OF THE DRY AIRMASS. BRIEF HEAVY RAIN
WILL BE POSSIBLE OVER THE HIGHER TERRAIN AND EASTERN PLAINS WHERE
THERE IS MORE MOISTURE.
THREAT FOR STORMS WILL DECREASE THIS EVENING. HOWEVER A COLD FRONT
WILL PUSH SOUTH TONIGHT AND INCREASE THE MOISTURE. BECAUSE OF
THIS...WILL KEEP LOW POPS IN THE FORECAST THROUGH THE NIGHT.
A MOIST AIRMASS WILL BE IN PLACE FRIDAY WITH PRECIPITABLE WATER
VALUES OF OVER AN INCH. DEW POINTS WILL BE IN THE 50S THROUGH THE
DAY. CAPES WILL BE HIGHER FRIDAY BECAUSE OF THE INCREASED
MOISTURE...POSSIBLY UP TO 1500 J/KG IF THE HIGHER DEW POINTS ON
THE GFS MODEL OCCURS. SHEAR WILL BE MARGINAL FOR SEVERE
STORMS...BUT MAY BE ENOUGH FOR A FEW SEVERE STORMS...MAINLY EAST.
HEAVY RAIN WILL LIKELY OCCUR WITH THE STRONGER STORMS. FORTUNATELY
WINDS ALOFT WILL BE 15 TO 25 KNOTS...SO STORMS SHOULD MOVE OFF TO
THE EAST ONCE THEY FORM. IF STORMS REFORM OR TRAIN OVER THE SAME
AREA...FLASH FLOODING WILL BE POSSIBLE.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 329 PM MDT THU JUL 10 2014
THUNDERSTORMS TO CONTINUE ACROSS THE AREA FRIDAY EVENING...MAINLY
ACROSS THE PLAINS AS BACK EDGE OF MID LEVEL TROUGH MOVES OVER THE
REGION. WITH PRECIPITABLE WATER VALUES OVER AN INCH ACROSS THE
PLAINS. LOCALLY HEAVY RAIN WILL BE POSSIBLE. IN ADDITION...WITH
CAPE VALUES OF AROUND 1000 J/KG EXPECTED FAR NORTHEAST CORNER SOME
HAIL CAN BE EXPECTED. LOOKS LIKE THERE WILL BE ENOUGH STORM MOTION
TO LIMIT THE THREAT FOR FLOODING. MOST STORMS TO END AROUND
MIDNIGHT AS SUBSIDENCE INCREASES.
ON SATURDAY...RIDGE RETROGRADES WITH FLOW BECOMING WESTERLY. STILL
A GOOD FETCH OF SUBTROPICAL MOISTURE ACROSS THE STATE WITH
PRECIPITABLE WATER VALUES OVER AN INCH ACROSS THE PLAINS. MID
LEVEL SHORTWAVE LOOKS TO MOVE SOUTHEAST ACROSS THE NORTHERN PLAINS
STATES DURING THE AFTERNOON WITH SOME MID LEVEL QG ASCENT ACROSS
NORTHEAST COLORADO. COMBINATION OF LIFT AND MOISTURE TO PROVIDE A
CHANCE OF THUNDERSTORMS MOST LOCATIONS DURING THE AFTERNOON.
MODELS GENERATE QPF ACROSS MUCH OF THE AREA...WITH THE GFS SHOWING
THE MOST. WITH SUFFICIENT MOISTURE AVAILABLE...STORMS COULD
PRODUCE LOCALLY HEAVY RAIN. APPEARS THERE IS ENOUGH STORM MOTION
TO KEEP THE STORMS MOVING...LIMITING THE FLASH FLOOD THREAT.
MODELS SHOW CAPE VALUES AROUND 1000-1500 J/KG NORTHEAST
PLAINS...SO HAIL ALSO A POSSIBILITY. COOLER AIRMASS OVER THE
AREA...WITH HIGHS IN THE MIDDLE 80S ACROSS THE PLAINS. FOR
SUNDAY...NORTHWEST FLOW ALOFT CONTINUES WITH UPPER RIDGE ACROSS
THE GREAT BASIN. CENTER OF THE HIGH LOOKS TO BE OVER EASTERN
NEVADA. WESTERLY FLOW ALOFT TO BRING SLIGHTLY DRIER AIR INTO
COLORADO...SHUNTING SOME OF THE SUBTROPICAL MOISTURE FEED SOUTH
AND EAST OF THE CFWA. STILL SUFFICIENT MOISTURE FOR A CHANCE OF
AFTERNOON AND EVENING THUNDERSTORMS MOST LOCATIONS...BUT MID LEVEL
SUBSIDENCE MAY LIMIT THE COVERAGE OF STORMS. STORMS COULD STILL
PRODUCE BRIEF HEAVY RAIN. LITTLE CHANGE IN TEMPERATURES EXPECTED
FROM SATURDAY...WITH HIGHS IN THE MIDDLE 80S OVER NORTHEAST
COLORADO. ON MONDAY...THE NORTHWEST FLOW ALOFT CONTINUES. MODELS
SHOW A MID LEVEL SHORTWAVE MOVING ACROSS CENTRAL PLAINS DURING THE
AFTERNOON WITH THE TAIL END INTO NORTHEAST COLORADO. WEAK FRONT
LOOKS TO PUSH INTO NORTHEAST PLAINS WITH SLIGHTLY COOLER AIR. BOTH
ECMWF AND GFS SHOW SUBTROPICAL MOISTURE PUSHING NORTHWARD AGAIN
WITH AN INCREASE IN PRECIPITABLE WATER. SHOULD SEE A CHANCE OF
AFTERNOON AND EVENING THUNDERSTORMS MOST LOCATIONS DUE TO THE LIFT
AND MOISTURE.
FOR THE LATER DAYS...TUESDAY THROUGH THURSDAY: MODELS SHOW
DEEPENING UPPER TROUGH ACROSS THE NORTHERN AND CENTRAL PLAINS
STATES TUESDAY AND WEDNESDAY WITH A MID LEVEL SHORTWAVE TROUGH
MOVING INTO NORTHEAST COLORADO TUESDAY AFTERNOON INTO WEDNESDAY.
SURFACE FRONT LOOKS TO PUSH INTO THE NORTHEAST PLAINS DURING THE
AFTERNOON. SUFFICIENT LIFT AND MOISTURE FOR A CHANCE OF MAINLY
AFTERNOON AND EVENING THUNDERSTORMS...BEST CHANCE EAST OF THE
CONTINENTAL DIVIDE. COOLER AIR TO SPILL INTO NORTHEAST COLORADO
BEHIND THE FRONT...WITH HIGHS EXPECTED TO ONLY BE IN THE MID AND
UPPER 70S ACROSS THE PLAINS. MODELS SHOW TROUGH MOVING INTO
SOUTHEAST COLORADO THURSDAY...WITH A DECREASING CHANCE FOR
THUNDERSTORMS. TEMPERATURES WARM SLIGHTLY BUT STILL BE A BIT
BELOW AVERAGE.
&&
.AVIATION...(FOR THE TAFS THROUGH 06Z FRIDAY EVENING)
ISSUED AT 1012 PM MDT THU JUL 10 2014
PARTLY CLOUDY SKIES OVER THE METRO AREA AT PRESENT TIME WILL BECOME
MOSTLY CLOUDY TO OVERCAST SOON AFTER THE PASSAGE OF A COLD FRONT/
STRONG THUNDERSTORM OUTFLOW BOUNDARY FROM THE NORTH. THIS FRONTAL
BOUNDARY NOW RACING SOUTH THROUGH CENTRAL WELD COUNTY...SHOULD
ARRIVE IN THE DENVER AREA BY 0430Z...IF NOT SOONER. EXPECT GUSTY
NORTH-NORTHEAST WINDS TO AROUND 25KTS FOR ABOUT AN HOUR OR SO
AFTER ITS PASSAGE THEN EAST-NORTHEAST WINDS OF 7-13KTS FOR THE
REST OF THE NIGHT. ALSO LOOK FOR SKIES TO FILL WITH LOW AND MID-
LEVEL CLOUDS AND A 30-40 PCT CHANCE OF SHOWERS AND ISOLATED
T-STORMS THROUGH 08Z. COULD SEE CEILINGS LOWERING TO AROUND 5000
FT ALG...PARTICULARLY AT APA AND BJC AFTER MIDNIGHT. MOSTLY CLOUDY
SKIES ARE EXPECTED TO LINGER UNTIL AROUND SUNRISE THEN SKIES WILL
PARTIALLY CLEAR.
&&
.HYDROLOGY...
ISSUED AT 329 PM MDT THU JUL 10 2014
THREAT FOR FLASHING FLOODING TODAY WILL BE VERY LOW DUE TO A
DRY AIRMASS AND STORMS MOVING AROUND 15 MPH.
THE THREAT FOR FLASH FLOODING WILL INCREASE FRIDAY. AIRMASS WILL
BECOME MOIST. THE NUMBER OF THUNDERSTORMS IS ALSO EXPECTED TO
INCREASE WITH HEAVY RAIN ACCOMPANYING THE STRONGER STORMS. STORMS
WILL BE MOVING AROUND 10 TO 20 MPH ON FRIDAY. IF STORMS REFORM OR
TRAIN OVER THE SAME AREA FLASH FLOODING WILL BE POSSIBLE.
THUNDERSTORMS WILL BE POSSIBLE SATURDAY AND SUNDAY. AIRMASS TO
REMAIN FAIRLY MOIST SATURDAY WITH SOME DRYING SUNDAY. LOCALLY
HEAVY RAIN WILL BE POSSIBLE WITH SOME OF THE STORMS SATURDAY...BUT
STORMS SHOULD BE MOVING AROUND 15 TO 20 MPH...LIMITING THE FLASH
FLOOD THREAT. &&
.BOU WATCHES/WARNINGS/ADVISORIES...
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BAKER
SHORT TERM...MEIER
LONG TERM...D-L
AVIATION...BAKER
HYDROLOGY...MEIER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
656 AM EDT FRI JUL 11 2014
.SYNOPSIS...
TRANQUIL WEATHER TODAY AND TOMORROW AS HIGH PRESSURE SETTLES OVER
THE REGION. UNSETTLED WEATHER IN THE FORM OF SHOWERS AND
THUNDERSTORMS RETURNS LATE SUNDAY INTO EARLY NEXT WEEK. THERE IS
THE POTENTIAL FOR STRONG WINDS AND HEAVY RAINFALL.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
7 AM UPDATE....
COLD FRONT IS NOW SOUTH OF NANTUCKET WITH ALL LOCATIONS REPORTING
N TO NE WINDS. DRIER/LESS HUMID AIRMASS BEGINNING TO STREAM ACROSS
THE REGION WITH DEW PTS NOW IN THE 50S...EXCEPT STILL IN THE 60S
CLOSER TO THE FRONT ACROSS THE SOUTH COAST. MID LEVEL TROUGH
REMAINS WEST OF NEW ENGLAND AND AS A RESULT SW FLOW ALOFT PREVAILS
ACROSS THE REGION. THIS IS RESULTING IN MID AND HIGH CLOUDS MOVING
ACROSS EASTERN CT/RI AND EASTERN MA. HOWEVER BACK EDGE OF THIS
CLOUD SHIELD IS FROM AROUND HARTFORD CT NORTHEAST TO MANCHESTER NH
AND MOVING STEADILY EASTWARD. THUS EXPECT DECREASING CLOUDS AS THE
MORNING PROGRESSES. SOME OF THE GUIDANCE INCLUDING THE HRRR HINTS
AT THE POTENTIAL FOR A FEW AFTERNOON SHOWERS AS THE MID LEVEL
TROUGH MOVES THRU THE REGION. HOWEVER A CLOSER INSPECTION OF THE
GUID INDICATES MID LEVEL DRY AIR BECOMES DEEPER AS THE DAY
PROGRESSES. THIS SHOULD PRECLUDE SHOWER DEVELOPMENT AND ONLY YIELD
SOME MODERATE BUILDUPS. PREVIOUS FORECAST HANDLES THIS WELL SO NO
MAJOR CHANGES EXPECTED WITH THIS UPDATE. EARLIER DISCUSSION BELOW.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
RAIN SHIELD CONTINUES TO MOVE NORTHEASTWARD AND HAS DROPPED SOME
PRECIP ACROSS MVY EARLY THIS MORNING. BELIEVE THAT ACK WILL ALSO
GET CLIPPED WITHIN THE HOUR AS RAIN SHOWERS CONTINUE TO MOVE OVER
THE REGION. STATIONARY FRONT IS STILL STRADDLING JUST SOUTH OF THE
MAINLAND...PER SURFACE DEWPOINT OBSERVATIONS. THIS FRONT WILL
CONTINUE A VERY SLOW SOUTHWARD MOVEMENT THROUGH OUT THE DAY.
CIRRUS SHIELD HAS REALLY LIMITED ANY RADIATIONAL COOLING EARLY
THIS MORNING SO BELIEVE THAT MIN TEMPS WILL REMAIN STEADY OVER
THE NEXT FEW HOURS. OTHERWISE A PRETTY QUIET NIGHT WITH COMFORTABLE
CONDITIONS.
TODAY...
HIGH PRESSURE WILL BUILD OVER THE REGION TODAY WITH THE STALLED
FRONT STILL LINGERING TO THE SOUTH. ALTHOUGH THE LOW LEVELS WILL BE
DRY...SOME INCREASE MOISTURE IN THE MID TO UPPER LEVELS WILL PRODUCE
SOME DIURNAL CU THIS AFTERNOON. SOME OF THE MODEL GUIDANCE IS STILL
TRYING TO SQUEEZE OUT SOME QPF TODAY AS UPPER LEVEL JET MOVES OVER
THE REGION PROVIDING SOME LIFT. BECAUSE THERE IS A GOOD AMOUNT OF
DRY AIR IN THE LOW LEVELS PER SOUNDINGS...KEPT A DRY FORECAST.
TEMPERATURES WILL CONTINUE TO BE COOLER THEN THE START OF THE WORK
WEEK WITH HIGHS REACHING IN THE LOW TO MID 80S. SEA BREEZES WILL
DEVELOP ALONG BOTH COASTLINES KEEPING COASTAL AREAS IN THE 70S.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT...
HIGH PRESSURE WILL CONTINUE TO DOMINATE ACROSS SOUTHERN NEW ENGLAND
TONIGHT. THIS WILL ALLOW FOR A WEAK PRESSURE GRADIENT AND WITH
MOSTLY CLEAR SKIES COULD SEE SOME RADIATIONAL COOLING. TEMPS WILL
GENERALLY BE IN THE UPPER 50S WITH LOW 60S ACROSS THE METRO REGIONS.
PATCHY FOG MAY DEVELOP ESPECIALLY ACROSS VALLEY REGIONS BUT HAVE
A LOWER CONFIDENCE.
TOMORROW...
HIGH PRESSURE WILL BEGIN TO SLIDE EASTWARD ON SATURDAY. MOISTURE
WILL SLOWLY INCREASE AS WINDS WILL SWITCH TO THE SOUTHWEST NEAR THE
END OF THE DAY. THIS WILL ALLOW FOR MORE DIURNAL CU TO DEVELOP.
STILL A PRETTY WEAK PRESSURE GRADIENT SO SEA BREEZE DEVELOPMENT
LOOKS LIKELY ALONG BOTH COASTLINES.
FULL MOON WILL OCCUR OVER THE WEEKEND ALLOWING FOR THE
ASTRONOMICAL HIGH TIDES TO OCCUR. THERE COULD BE SOME MINOR
SPLASHOVER ACROSS SCITUATE AND P-TOWN HARBOR. OTHERWISE EXPECT
VERY LITTLE IMPACT ON THE LATE SATURDAY HIGH TIDE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGHLIGHTS...
* MORE HUMID AND BREEZY SUNDAY...SHOWERS POSSIBLE LATE
* STRONG TO SEVERE THUNDERSTORMS & HEAVY RAINFALL POSSIBLE MON/TUE
* TREND TOWARD DRIER AND LESS HUMID WEATHER MID TO LATE NEXT WEEK
SYNOPTIC OVERVIEW AND MODEL PREFERENCES...
GUIDANCE CONTINUES TO SIMULATE AN EVOLVING HIGHLY ANOMALOUS
AMPLIFIED NORTHERN STREAM THIS PERIOD WITH A FULL LATITUDE RIDGE
DEVELOPING ACROSS THE WESTERN CONUS INTO CANADA. DOWNSTREAM A POTENT
CLOSED LOW ADVECTS SOUTHWARD INTO THE GREAT LAKES EARLY NEXT WEEK.
THIS YIELDS A DEEP MOIST SW FLOW ALONG THE EASTERN SEABOARD WITH AN
INFLUX OF GULF AND ATLANTIC MOISTURE INTO NEW ENGLAND. A STRONG
FRONTAL ZONE WILL ACCOMPANY THIS CLOSED LOW AND WILL BECOME THE
FOCUS FOR CONVECTION AND HEAVY RAINFALL EARLY NEXT WEEK ACROSS NEW
ENGLAND. ANOMALOUS JET DYNAMICS ASSOCIATED WITH THIS FEATURE
COMBINED WITH PEAK CLIMATOLOGICAL HEATING WILL INCREASE THE RISK FOR
STRONG TO SEVERE STORMS HERE IN SOUTHERN NEW ENGLAND. ALSO GIVEN THE
DEEP SOUTHWEST FLOW THESE STORMS WILL HAVE THE POTENTIAL OF BACK
BUILDING AND TRAINING OVER THE SAME AREA YIELDING A RISK OF FLASH
FLOODING. AS FOR MODEL GUIDANCE...BOTH THE 12Z GEFS AND ECENS
ENSEMBLES ALONG WITH THE 00Z DETERMINISTIC RUNS OF GFS AND ECMWF ARE
IN VERY GOOD AGREEMENT ON TROUGH/RIDGE AMPLITUDE AND TIMING OF
FRONTAL PASSAGE. THUS WILL BLEND ALL DATA SOURCES FOR THIS PORTION
OF THE FORECAST.
DAILY DETAILS...
SAT NIGHT...
QUIET/DRY WEATHER AS HIGH PRES LINGERS ALONG THE COAST. SEASONABLE
TEMPS WITH LOWS IN THE LOW TO MID 60S. TOLERABLE HUMIDITY WITH DEW
PTS IN THE U50S TO L60S.
SUNDAY...
BECOMING MORE HUMID AND BREEZY AS LOW LEVEL WARM AIR ADVECTION
INCREASES AS SURFACE HIGH DRIFTS OFFSHORE. NICE WEATHER LINGERS MUCH
OF THE DAY ACROSS EASTERN NEW ENGLAND PER GOOD MODEL AGREEMENT ON
WARM ADVECTION PRECIP ARRIVING AFTER 18Z ACROSS WESTERN NEW ENGLAND
AND PROBABLY NOT UNTIL AFTER 00Z OVER RI AND EASTERN MA. THUS DRY
WEATHER FOR MUCH OF THE DAYLIGHT HOURS ACROSS RI AND EASTERN MA.
EARLY NEXT WEEK...
WARM AND MUGGY CONDITIONS AHEAD OF A STRONG FRONTAL BOUNDARY
APPROACHING THE REGION FROM THE WEST. AS MID LEVEL FLOW AMPLIFIES
AND BACKS...DEEP S-SW FLOW ALOFT DEVELOPS ALONG THE EASTERN
SEABOARD. THIS RESULTS IN A SLOW MOVING FRONTAL BOUNDARY WITH AN
INFLUX OF GULF AND ATLC MSTR. STRONG JET DYNAMICS COUPLED WITH AT
LEAST MODEST INSTABILITY INCREASES THE RISK OF STRONG TO SEVERE
STORMS ALONG AND AHEAD OF THE APPROACHING FRONT MON AND TUE. IN
ADDITION THE DEEP S-SW FLOW ALOFT WILL PROVIDE AN ENVIRONMENT
FAVORABLE FOR BACK BUILDING STORMS AND TRAINING OVER THE SAME AREA.
THUS A RISK OF FLASHING FLOODING.
MID TO LATE NEXT WEEK...
ENSEMBLES AND DETERMINISTIC GUIDANCE SUGGEST A FRONTAL PASSAGE
AROUND WED ALONG WITH MID TO UPPER TROUGH DEAMPLIFYING AS IT LIFTS
NE INTO ONTARIO AND QUEBEC. THIS SUPPORTS A TREND TOWARD DRIER AND
LESS HUMID WEATHER MID TO LATE NEXT WEEK.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY/...HIGH CONFIDENCE.
7 AM UPDATE...NO MAJOR CHANGES FROM 06Z TAFS. MVFR VSBYS IN PATCHY
SHALLOW FOG OVER CAPE COD AND THE ISLANDS WILL IMPROVE TO VFR BY
15Z. EARLIER DISCUSSION BELOW.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TODAY TIL TOMORROW...VFR THROUGH THE PERIOD. SEA BREEZES ONCE
AGAIN LIKELY AT NEAR SHORE TERMINALS FOR TODAY AND TOMORROW.
LOW CONFIDENCE ON PATCHY FOG ACROSS THE SOUTH COASTLINE.
KBOS TAF...HIGH CONFIDENCE IN TAF. SEA BREEZE SHOULD START 13-15Z
TODAY.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT...HIGH CONFIDENCE FOR VFR AND DRY WEATHER.
SUNDAY...VFR BUT LOW RISK OF MVFR LATE IN THE DAY WESTERN NEW
ENGLAND AS SHOWERS ENTER THIS AREA. HIGH CONFIDENCE ON TRENDS BUT
LOWER CONFIDENCE ON EXACT TIMING.
SUNDAY NIGHT THROUGH TUESDAY...LOW TO MODERATE CONFIDENCE. MAINLY
VFR DURING THE DAYLIGHT HOURS BUT LOWERING TO MVFR/IFR AT NIGHT IN
AREAS OF FOG. ALSO MVFR IN SCT SHOWERS/TSTMS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TODAY THROUGH SATURDAY/...HIGH CONFIDENCE.
A COLD FRONT WILL SLOWLY MOVE SOUTH OF THE WATERS TODAY AND
TOMORROW. A FEW ISOLATED SHOWERS MAY OCCUR TODAY BUT DRY WEATHER
SHOULD PREVAIL BY THE AFTERNOON LASTING THROUGH THE PERIOD. WINDS
AND SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS THROUGH
SATURDAY.
OUTLOOK...SATURDAY NIGHT THROUGH TUESDAY...
SATURDAY NIGHT...QUIET BOATING WEATHER WITH LIGHT SSW WINDS AND DRY
WEATHER.
SUNDAY...SSW WINDS INCREASE AS FRONT APPROACHES. SHOWERS/TSTMS HOLD
OFF UNTIL SUN NIGHT.
MON AND TUE...PERSISTENT MODEST SSW WINDS 15-20 KT WITH HIGHER
GUSTS. SCT TSTMS WITH HEAVY RAIN AND STRONG WINDS POSSIBLE. PATCHY
DENSE FOG POSSIBLE ESPECIALLY AT NIGHT AND EARLY MORNING.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...DUNTEN
SHORT TERM...DUNTEN
LONG TERM...NOCERA
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1018 AM EDT FRI JUL 11 2014
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE NORTHEAST STATES TODAY, THEN
SHIFT OFFSHORE LATER TONIGHT AND SATURDAY. A WARM FRONT SHOULD
LIFT NORTH OF THE REGION SUNDAY, THEN A COLD FRONT IS FORECAST TO
ARRIVE LATE MONDAY NIGHT AND ESPECIALLY TUESDAY. THIS FRONT SHOULD
BE SETTLING TO OUR SOUTH AND EAST WEDNESDAY, AS HIGH PRESSURE
GRADUALLY ARRIVES FROM THE WEST DURING THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SFC FRONTAL BOUNDARY THAT STALLED OVER THE DELMARVA YESTERDAY
HAS FINALLY MOVED SOUTH AND EAST OF THE REGION THIS MORNING. A BROAD
SFC HIPRES OVER UPSTATE NY WILL BUILD EWD INTO NEW ENGLAND TODAY.
LIGHT NELY FLOW AROUND THE HIGH THIS MORNING HAS BEEN ASSOCIATED
WITH MARINE STRATUS ALONG THE SRN NJ COAST/DELMARVA. STRATUS IS
ALREADY MIXING OUT QUICKLY DURING THE MID MORNING IN SRN NJ AND NRN
DELAWARE BUT FARTHER SOUTH, WHERE THE 925 MB COLD FRONT HAS LAGGED
BEHIND THE SFC BOUNDARY AND LLVL MOISTURE HAS POOLED, LOW CLOUDS
WILL TAKE LONGER TO ERODE FROM NORTH TO SOUTH.
SEVERAL HIRES MODELS SHOW POP UP SHOWERS AND STORMS DEVELOPING IN
EXTREME SERN PA AND OVER THE DELMARVA THIS AFTN DURING THE PEAK
HEATING HRS. THIS APPEARS TO BE WHERE THE HIGHER MOISTURE RESIDES
WITH SFC DEWPOINTS IN THE UPPER 60S VS UPPER 50S/LOWER 60S FARTHER
NORTH). LIFT WOULD BE ATTRIBUTED TO AN APPROACHING SHORTWAVE TROUGH
AXIS AND EVEN THE RUC SHOWS SFC CONVERGENCE DEVELOPING NEAR THE ERN
SHORE OF THE CHSPK BAY AROUND 18Z. THE FORCING WILL BE WEAK THOUGH,
FAVORING MINIMAL CONVECTIVE COVERAGE. INSTABILITY/SHEAR PROFILES NOT
INDICATIVE OF A SEVERE THREAT, BUT CANNOT RULE OUT AN ISO STRONG
STORM DEVELOP OVER THE DELMARVA.
MAX TEMPS TODAY IN THE LOW TO MID 80S EXCEPT 5-10F COOLER ALONG THE
COAST AND IN THE POCONOS. MAY NEED TO LOWER TEMPS A COUPLE OF
DEGREES IN THE CENTRAL DELMARVA IF LOW CLOUDS HOLD ON A BIT LONGER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
THE MID LEVEL TROUGH IS FORECAST TO MOVE TO OUR EAST TONIGHT. ANY
ISOLATED PRECIPITATION EARLY THIS EVENING SHOULD DISSIPATE QUICKLY
AS THE ATMOSPHERE CONTINUES TO TO STABILIZE AND AS HIGH PRESSURE
BUILDS INTO OUR REGION FROM THE NORTH.
THE SKY IS EXPECTED TO BE MOSTLY CLEAR FOR TONIGHT AND THE WIND
SHOULD BECOME LIGHT AND VARIABLE. THE COMBINATION IS ANTICIPATED TO
ALLOW TEMPERATURES TO FALL INTO THE UPPER 50S TO MIDDLE 60S IN MUCH
OF OUR REGION.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE OVERALL SYNOPTIC SETUP IS COMPRISED OF A POTENT UPPER-LEVEL
TROUGH THAT CLOSES OFF AS IT DIGS ACROSS THE MIDWEST AND GREAT LAKES
REGION SUNDAY AND MONDAY, THEN BEGINS TO SHIFT INTO PORTIONS OF THE
NORTHEAST TUESDAY AND WEDNESDAY. THIS FEATURE WILL DRIVE A COLD
FRONT ACROSS OUR AREA IN THE TUESDAY INTO WEDNESDAY TIME FRAME WITH
CONVECTIVE EPISODES AHEAD OF IT. THERE IS THE POTENTIAL FOR STRONG
TO SEVERE THUNDERSTORMS TO OCCUR ESPECIALLY TUESDAY AS THE MAIN
FEATURES ALOFT MOVE THROUGH. WE USED A MODEL BLEND FOR SATURDAY INTO
MONDAY, THEN MOSTLY BLENDED THE 00Z WPC GUIDANCE INTO CONTINUITY
THEREAFTER.
FOR SATURDAY AND SUNDAY...AS THE CENTER OF HIGH PRESSURE SHIFTS
FARTHER OFFSHORE SATURDAY, THE FLOW WILL TURN FROM EAST-SOUTHEAST TO
MORE SOUTHERLY. AS THIS OCCURS, SOME INCREASE IN THE WAA AHEAD OF AN
AMPLIFYING UPPER-LEVEL TROUGH INTO THE GREAT LAKES REGION SHOULD
ORGANIZE A WARM FRONT TO OUR SOUTHWEST. THIS FRONT SHOULD THEN START
MIGRATING NORTHWARD SUNDAY. OVERALL SATURDAY LOOKS TO BE DRY WITH
HIGH PRESSURE CLOSE ENOUGH TO START AND THEN OVERALL A LACK OF
ORGANIZED LIFT. IF ISOLATED CONVECTION WHERE TO FORM IN THE
AFTERNOON, IT SHOULD BE TO OUR WEST ON THE PERIPHERY OF THE SURFACE
HIGH AND CLOSER TO THE TERRAIN INFLUENCES. AS THE UPPER-LEVEL FLOW
STARTS TO TURN MORE CYCLONIC SUNDAY, SOME SHOWERS AND THUNDERSTORMS
SHOULD DEVELOP MAINLY INLAND IN THE AFTERNOON PERHAPS FOCUSED NEAR A
LEE SIDE TROUGH. THIS WOULD BREAK OUR STRING OF NICE WEATHER ON THE
WEEKENDS AT LEAST FOR A PORTION OF OUR CWA.
FOR MONDAY THROUGH WEDNESDAY...A ROBUST UPPER-LEVEL TROUGH/CLOSED
LOW FOR THIS TIME OF THE YEAR IS FORECAST TO SLIDE ACROSS THE GREAT
LAKES REGION AND TOWARD THE NORTHEAST. LOW PRESSURE TRACKING ACROSS
CANADA WILL PULL A COLD FRONT INTO THE EAST LATER TUESDAY INTO
WEDNESDAY. THE PRESENCE OF STRENGTHENING CYCLONIC FLOW IN
COMBINATION WITH AN INCREASINGLY UNSTABLE AIRMASS WILL INITIATE
SHOWERS AND THUNDERSTORMS. THIS MAY BE TIED TO AN INITIAL LEE SIDE
TROUGH MONDAY WITH MORE OF A CONVECTIVE ORGANIZATION ACROSS OUR
WESTERN ZONES, THEN MORE FOCUSED TUESDAY WITH THE COLD FRONT /ALSO A
PRE-FRONTAL TROUGH/ ALONG WITH SOME COOLING ALOFT AND STRONGER FLOW.
THE INSTABILITY SHOULD BE ENHANCED SOME AS DEEPER MOISTURE ADVECTS
NORTHEASTWARD IN ADVANCE OF THE SURFACE FRONT. IT WILL BE WARM AND
HUMID AS WELL, AND MONDAY LOOKS TO BE THE HOTTEST DAY AS THE
LOW-LEVEL WAA SHOULD PEAK. AS OF NOW, WE ARE NOT ANTICIPATING ANY
HEAT RELATED HAZARDS ACROSS THE CWA.
THE LARGE SCALE LIFT IS FORECAST TO INCREASE SUBSTANTIALLY TUESDAY
WITH THE PRESENCE OF A STRONG SHORT WAVE SLIDING ACROSS THE REGION.
THIS COULD RESULT IN SOME STRONG TO SEVERE CONVECTIVE EPISODES
MONDAY AND PARTICULARLY ON TUESDAY. WHILE THERE IS LESS CERTAINTY
WITH THE DETAILS, THE POTENTIAL IS THERE FOR SEVERE THUNDERSTORMS.
BASED ON THE FORECAST SOUNDINGS, IT APPEARS THAT LINE SEGMENTS WITH
EMBEDDED BOWING STRUCTURES WOULD BE THE MAIN STORM MODE GIVEN A MORE
UNIDIRECTIONAL FLOW THROUGH THE COLUMN. THE CONVECTION THAT OCCURS
ON MONDAY MAY HAVE AN IMPACT ON WHAT DEVELOPS ON TUESDAY. THE PW
VALUES ARE FORECAST TO INCREASE TO AROUND 2 INCHES MONDAY AND
TUESDAY, WHICH WILL ALLOW FOR LOCALLY HEAVY RAIN TO OCCUR. THIS
COULD ALSO INCREASE THE THREAT FOR WATER LOADED DOWNDRAFTS. WE WILL
MAINTAIN A MENTION IN THE HAZARDOUS WEATHER OUTLOOK.
THE COLD FRONT SHOULD BE EASING TO OUR SOUTH AND EAST DURING
WEDNESDAY, WITH DRYING ARRIVING FROM THE NORTHWEST. THERE COULD BE
SOME CONVECTION LINGERING TO START ACROSS OUR EASTERN ZONES, AND
THEREFORE MUCH OF THE REGION WAS KEPT DRY.
FOR THURSDAY...A LARGE UPPER-LEVEL TROUGH IS FORECAST TO BE IN
PLACE, HOWEVER THE CENTER OF IT LOOKS TO BE NORTH OF THE GREAT
LAKES. THIS WILL MAINTAIN CYCLONIC FLOW ACROSS OUR AREA AS SURFACE
HIGH PRESSURE GRADUALLY BUILDS IN FROM THE WEST. WE ARE ANTICIPATING
A COOLER AIRMASS TO BE IN PLACE ALONG WITH LOWER DEW POINTS. NO
MAJOR CHANGES WERE MADE TO THIS TIME FRAME.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
EARLIER LOW CLOUDS AT MIV/ACY DISSIPATED BETWEEN 12-13Z THIS MRNG.
VFR TODAY, BUT AN ISO POP UP SHRA/TSRA POSSIBLE IN SOUTHWESTERN AREA
TERMINALS. THE BEST CHANCE TO SEE THIS ACTIVITY WOULD BE ILG, BUT
COVERAGE TOO LOW TO INCLUDE IN 12Z TAFS. NE WINDS 5-10 KT TDA WILL
BECOME SELY THIS EVE AROUND 5 KT.
OUTLOOK...
SATURDAY...PERHAPS LOCAL MVFR/IFR STRATUS OR FOG TO START,
OTHERWISE VFR. SOUTHERLY WINDS MAINLY 5-10 KNOTS.
SUNDAY AND MONDAY...TIMES OF SUB-VFR WITH SOME SHOWERS AND
THUNDERSTORMS AROUND. THE BEST CHANCE APPEARS TO BE FOR THE FARTHER
INLAND TERMINALS EACH AFTERNOON AND EVENING.
TUESDAY...A BETTER CHANCE FOR ORGANIZED SHOWERS AND THUNDERSTORMS AS
A COLD FRONT ARRIVES. SOME STORMS MAY PRODUCE GUSTY SURFACE WINDS.
&&
.MARINE...
THE FRONTAL BOUNDARY WILL CONTINUE TO SINK TO OUR SOUTH TODAY,
ALLOWING HIGH PRESSURE FROM THE NORTH TO BUILD ACROSS THE COASTAL
WATERS OF NEW JERSEY AND DELAWARE FOR TONIGHT. NE WINDS AROUND
10-15 KT ARE OCCURRING OVER THE COASTAL ATLANTIC WATERS THIS MRNG.
THESE WINDS WILL DECREASE BY LATE AFTN. LIGHT AND VARIABLE WINDS
TNGT.
WIND SPEEDS AND WAVE HEIGHTS ARE ANTICIPATED TO REMAIN BELOW THE
SMALL CRAFT ADVISORY CRITERIA FOR TODAY AND TONIGHT.
OUTLOOK...
SATURDAY...HIGH PRESSURE NEAR THE NEW ENGLAND COAST WILL SHIFT
FARTHER OFFSHORE. THIS WILL RESULT IN THE FLOW TURNING MORE
SOUTHERLY WITH TIME, HOWEVER IT IS ANTICIPATED TO BE LIGHT.
SUNDAY THROUGH TUESDAY...THE FLOW BECOMES MORE SOUTHWESTERLY ON
SUNDAY. THESE WINDS STRENGTHEN MONDAY AND TUESDAY AHEAD OF A COLD
FRONT, HOWEVER THEY SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA. IF ENOUGH MIXING OCCURS ON TUESDAY, SOME MARGINAL ADVISORY
GUSTS CAN OCCUR ESPECIALLY NEARSHORE. THE SOUTHERLY FLOW WILL BUILD
THE SEAS AND AN ADVISORY MAY BE NEEDED MONDAY AND TUESDAY FOR THE
COASTAL WATER ZONES. THE WAVEWATCH GUIDANCE HOWEVER COULD BE
OVERDONE GIVEN THE SOUTHERLY FLOW WITHIN A WAA REGIME. SOME SHOWERS
AND THUNDERSTORMS ARE ANTICIPATED MONDAY AND TUESDAY, SOME WITH
POTENTIALLY GUSTY WINDS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GORSE
NEAR TERM...KLEIN
SHORT TERM...IOVINO
LONG TERM...GORSE
AVIATION...GORSE/IOVINO/KLEIN
MARINE...GORSE/IOVINO/KLEIN
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
935 PM EDT SAT JUL 12 2014
.UPDATE...
SHOWERS AND STORMS HAVE DECREASED FAIRLY QUICKLY LATE THIS AFTERNOON
AND EVENING WITH MOST OF THE LIGHT RAIN ACTIVITY ACROSS THE INLAND
CENTRAL PARTS OF THE FORECAST AREA. A SW-NE ORIENTED MID LEVEL
TROUGH WITH EMBEDDED VORT LOBE CONTINUES TO LIFT SLOWLY WNW TO
NW...AND RAP MODEL SHOWS THE TROUGH AXIS LOCATED FROM ABOUT JESUP
GA TO VALDOSTA GA BY 12Z SUN SO A FEW SHOWERS WILL BE POSSIBLE
NEAR THIS AREA OVERNIGHT. AT SFC...WEAK LOW LEVEL TROUGHING WILL
BE LOCATED ROUGHLY NORTH TO SOUTH NEAR THE COASTAL LOCATIONS WITH
WEAK CONVERGENCE ENABLING SCT SHOWERS AND A FEW THUNDERSTORMS TO
DEVELOP AT TIMES MAINLY FROM THE COAST TO 60 NM FROM SHORE THROUGH
EARLY SUN MORNING. LOWS TONIGHT IN THE LOWER TO MID 70S AGAIN.
AS MID TO UPPER LEVEL CLOUD DEBRIS FADE TONIGHT...PATCHY TO
POSSIBLY AREAS OF FOG SHOULD DEVELOP...MAINLY IN SE GA AFTER MIDNIGHT.
&&
.AVIATION...
MVFR VISIBILITIES ARE EXPECTED THROUGH 12Z AT VQQ...WITH PERIODS
OF IFR CONDITIONS POSSIBLE. MVFR VISIBILITIES MAY DEVELOP AT GNV
AFTER 08Z. VFR CONDITIONS ARE EXPECTED ELSEWHERE AND SHOULD
PREVAIL REGION-WIDE BY 13Z. SCATTERED SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP AFTER 16Z...WITH TIMING AND INTENSITY
IN DOUBT AT THE DUVAL COUNTY TERMINALS AND SSI. USED VCTS FOR
THOSE TERMINALS AND A PROB30 FOR SUB-VFR CONDITIONS AT GNV...AS
ACTIVITY SHOULD BE MORE NUMEROUS AND FOCUSED INLAND DURING THE
LATE AFTERNOON AND EVENING HOURS. THE SEA BREEZE WILL MOVE
INLAND AFTER 15Z...WITH SOUTHEAST WINDS OF 10-15 KTS EXPECTED AT
SSI AND CRG.
&&
.MARINE...
A WEAK SE TO S FLOW IS ANTICIPATED REST OF TONIGHT AROUND 10 KT
AND SEAS OF ABOUT 2-3 FT. SCT SHOWERS AND ISOLD TSTMS EXPECTED
INTO SUN MORNING.
RIP CURRENTS: A LOW RISK ANTICIPATED THROUGH SUNDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 71 92 73 94 / 30 50 50 40
SSI 74 86 75 89 / 40 40 30 40
JAX 72 90 74 91 / 30 50 50 40
SGJ 73 86 74 87 / 30 30 30 30
GNV 71 89 72 89 / 30 50 50 50
OCF 71 90 72 89 / 20 50 50 50
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
SHASHY/NELSON/GUILLET
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
330 AM EDT FRI JUL 11 2014
.SYNOPSIS...
07Z WATER VAPOR AND H4 RAP ANALYSIS SHOWING AN UNIMPRESSIVE UPPER
LEVEL PATTERN ACROSS THE CONUS. RIDGING OVER THE SOUTHERN
PLAINS/SOUTHWEST DIPS SLIGHTLY DOWNSTREAM INTO AN EASTERN CONUS
TROUGH. THIS TROUGH DROPS DOWN INTO THE SOUTHEAST CONUS BUT IS
REALLY ONLY ACTING TO BRIEFLY WEAKEN THE UPPER RIDGE THAT HAS BEEN
IN PLACE. THIS WEAKNESS WILL LINGER OVER THE NORTHERN PART OF THE
STATE THROUGH SATURDAY...BUT GENERALLY HAVE LITTLE OVERALL IMPACT ON
OUR SENSIBLE WEATHER. DEEP MOISTURE IS IN PLACE ACROSS THE PENINSULA
EARLY THIS MORNING...ALTHOUGH A SWATH OF DRIER AIR CAN BE SEEN
CLEARLY IN WV IMAGERY APPROACHING THE SE FLORIDA COAST. MODELS HAVE
BEEN STRUGGLING WITH THE STRENGTH OF THE DRIER AIR THAT WILL BE
ARRIVING WITH THIS FEATURE OVER PREVIOUS DAYS...BUT SEEM TO HAVE
COME TO A CONSENSUS THAT THE IMPACT TO OUR CONVECTIVE COVERAGE WILL
BE LIMITED AT BEST AS THE SWATH ROTATES INTO THE SOUTHERN PENINSULA
TODAY. WE WILL TALK MORE ABOUT ANY IMPACT FROM THIS DRY AIR TODAY IN
THE SHORT TERM DISCUSSION BELOW.
AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS REMAINS ALIGNED OVER THE
CENTRAL PORTION OF THE STATE THIS MORNING. THE GRADIENT IS REALLY
LIGHT AND OUR CURRENT FLOW IS MOSTLY CONTROLLED BY THE DIURNAL LAND
BREEZE / SEA BREEZE CYCLES. LAND BREEZE IS RECENTLY BECOMING ACTIVE
ONCE AGAIN OVER THE COASTAL WATERS...WITH MORE AND MORE CONVECTIVE
ACTIVITY SHOWING UP ON REGIONAL RADARS. GENERALLY SPEAKING THIS
ACTIVITY SHOULD REMAIN JUST OFFSHORE THROUGH THE NEXT SEVERAL HOURS
AS THE BEST CONVERGENCE REMAINS OFFSHORE. ONLY EXCEPTION MIGHT BE UP
TOWARD CEDAR KEY AND CRYSTAL RIVER WHERE THE FLOW MAY ALLOW A BETTER
CHANCE FOR STORMS TO DEVELOP AT THE COAST...OR MIGRATE TO THE COAST
BEFORE SUNRISE. ELSEWHERE OVER LAND WE ARE SEEING A DRY AND
SEASONABLE MORNING UNDER SOME AREAS OF THIN HIGHER CLOUDS LEFTOVER
FROM THE CONVECTION ON THURSDAY.
&&
.SHORT TERM (TODAY AND TONIGHT)...
TODAY...FINAL DAY OF THE WORK WEEK IS UPON US. ARE WE LOOKING FOR
ANYTHING SPECIAL IN THE FORECAST TODAY? WELL...ACTUALLY NO. A VERY
TYPICAL SUMMER PATTERN REMAIN IN PLACE...AND THE ONE FEATURE (DRY
AIR ARRIVING ALOFT OVER THE SOUTHERN PART OF THE STATE) THAT LOOKED
EARLIER LIKE IT MIGHT RESULT IN REDUCED CONVECTION...NOW DOES NOT
APPEAR TO HAVE ENOUGH INFLUENCE TO REALLY IMPACT THE OVERALL
FORECAST. THE MAJORITY OF THE FORECAST AREA TODAY WILL ACTUALLY FIND
ITSELF UNDER A MOIST COLUMN WITH MID-LEVEL THETAE VALUES ABOVE CLIMO
AND PW VALUES APPROACHING OR EXCEEDING 2" (DEPENDING ON THE SELECTED
GUIDANCE). LOOKING AT A CROSS SECTION FROM NORTH TO SOUTH ACROSS THE
FORECAST AREA FOR THIS AFTERNOON...WE SEE EVEN DOWN TOWARD FORT
MYERS THE MINIMUM THETAE VALUES IN THE COLUMN ONLY DROP TO AROUND
325-328K. THIS IS NEAR NORMAL FOR THIS TIME OF YEAR...AND THE DEPTH
OF THIS "DRIER" ZONE IS NOT GREAT. MID-LEVEL TEMPERATURES (500MB OR
SO) ARE AROUND -8C TODAY. THESE VALUES ARE ALSO NEAR CLIMO AND
ALTHOUGH THEY WILL NOT OVERLY SUPPORT NUMEROUS STRONG UPDRAFTS IN
THE HAIL GROWTH ZONE...THEY SHOULD NOT SUPPRESS UPDRAFTS EITHER.
WITH ALL THIS IN MIND...THE DEEP MOISTURE OVER MUCH OF THE AREA TIPS
THE SCALES IN FAVOR OF AN ATMOSPHERE THAT IS SUPPORTIVE OF DEEP
CONVECTION.
NOW...MUCH OF THE TIME WE ARE DIAGNOSING THE POSITION OF THE
SUBTROPICAL RIDGE AXIS TO DETERMINE THE MEAN 1000-700MB FLOW AND
WHERE THIS SYNOPTIC FLOW WILL INTERACT WITH THE SEA-BREEZE TO MOST
FOCUS LIFT FOR STORMS. TODAY THE RIDGE AXIS IS OVER THE CENTRAL TO
NORTH-CENTRAL PORTIONS OF THE PENINSULA AND IS RATHER WEAK. THIS
POSITION AND FORM LEAVES MOST OF THE AREA IN A RATHER VARIABLE FLOW
PATTERN...AND EVEN THE SOUTHEAST FLOW DOWN TOWARD FORT MYERS IS ONLY
A FEW KNOTS. THEREFORE...THE NORMAL SPATIAL AND TEMPORAL PATTERNS OF
DEFINED REGIMES GO "OUT THE WINDOW" TODAY. EVEN WHERE WE DO HAVE A
MEASURABLE DIRECTION TO THE FLOW (SYNOPTIC OR SEA-BREEZE)...IT IS
WEAK ENOUGH THAT ANY THUNDERSTORM OUTFLOW WILL EASILY OVERWHELM IT.
ON THESE TYPES OF DAYS...STORMS MAY DEVELOP NEAR THE COAST AND MOVE
INLAND...ONLY TO COME BACK TOWARD THE COAST LATER IN THE DAY WITH
THE OUTFLOW FROM SECOND/THIRD/OR FOURTH GENERATION STORMS. THEREFORE
WILL NOT GET TOO DETAILED WITH THE POP GRIDS...BUT SHOW ABOVE CLIMO
COVERAGE (50-65%) THROUGH THE AFTERNOON/EVENING. THIS IS A GOOD
"MIDDLE OF THE ROAD" RANGE FOR MOST PLACES GIVEN THE UNDEFINED
PATTERN...BUT FAVORABLE THERMODYNAMICS. CERTAINLY SOME REGIONS WILL
SEE HIGHER COVERAGE...BUT IT WOULD BE JUST A GUESS TO TRY AND
PINPOINT EXACTLY WHERE. WILL LET THE NEXT SHIFT EVALUATE THE
CONVECTIVE PATTERN EARLY IN THE PROCESS LATER THIS MORNING AND
UPDATE AS NECESSARY.
OTHERWISE...OUTSIDE THE STORMS WE SHOULD SEE A WARM AND MUGGY JULY
DAY. TEMPERATURES WHERE THE STORMS HOLD OFF LONG ENOUGH WILL GET UP
TO WITHIN A DEGREE OR 2 OF 90. WEAK OFFSHORE FLOW THIS MORNING AT
THE BEACHES WILL SHIFT TO WEAK ONSHORE AFTER 1-2 PM.
TONIGHT...
EVENING SHOWERS AND STORMS WILL TAPER OFF WITH SUNSET AND THE LOSS
OF DIURNAL HEATING. LAND BREEZE CONVERGENCE WILL THEN RAMP SCT
CONVECTION BACK UP OVER THE COASTAL WATERS DURING THE SECOND HALF OF
THE NIGHT...AND INTO EARLY SATURDAY MORNING. GENERALLY SPEAKING WILL
BE LOOKING FOR A DRY FORECAST OVER MUCH OF THE LAND MASS AFTER 10-11
PM. LOW TEMPERATURES LOOK SEASONABLE WITH LOWER 70S INLAND AND
MIDDLE TO UPPER 70S NEAR THE COAST. HAVE A GREAT FRIDAY AND ENJOY
YOUR WEEKEND!
&&
.MID TERM (SATURDAY AND SUNDAY)...
THE SOUTHERN END OF AN EASTERN CONUS UPPER LEVEL TROUGH ACROSS
NORTH FL SAT LIFTS NORTHEASTWARD SAT NIGHT AND SUN AS UPPER LEVEL
RIDGING BUILDS IN ACROSS THE STATE. ATLANTIC HIGH PRESSURE RIDGES
WEST AS IT REMAINS IN THE VICINITY OF LATITUDE 30. THERE WILL BE
ENOUGH MOISTURE FOR ISOLATED BECOMING SCATTERED THUNDERSTORMS...
WITH THE HIGHEST ODDS INLAND IN THE AFTERNOONS. HOWEVER EXPECT SOME
COASTAL SHOWERS/STORMS IN THE EVENING AND MORNING HOURS.
TEMPERATURES RUN NEAR NORMAL.
&&
.LONG TERM (MONDAY THROUGH NEXT THURSDAY)...
UPPER RIDGING INITIALLY ACROSS FL FROM THE GULF TO THE ATLANTIC
SHIFTS SOUTHWARD DURING EARLY TO MID WEEK AS A RATHER ROBUST LOW
SWINGS DOWN OUT OF WESTERN CANADA AND THROUGH THE MIDWEST AND GREAT
LAKES BEFORE LIFTING BACK INTO QUEBEC. THE SURFACE RIDGE AXIS SLOWLY
TRAVERSES DOWN THE STATE...REACHING NORTHERN CUBAN COASTAL WATERS BY
THE END OF THE PERIOD. THE ATMOSPHERE CONTINUES MOIST WITH ISOLATED
TO SCATTERED SHOWERS AND STORMS. AS THE PREVAILING FLOW BECOMES
SOUTHWEST AND WESTERLY EXPECT MORE MORNING COASTAL SHOWERS THAT
INCREASE TO SCATTERED STORMS INLAND IN THE AFTERNOON.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
EARLY THIS MORNING. CONVECTION JUST OFFSHORE WILL LIKELY BE VISIBLE
FROM THE NEAR SHORE TERMINALS...BUT DO NOT EXPECT ANY OF THESE CELLS
TO MIGRATE ONSHORE TO IMPACT ANY TERMINALS UNTIL AT EARLIEST MID
MORNING. A GOOD COVERAGE OF SHOWERS AND STORMS EXPECTED FOR THE
AFTERNOON AND EARLY EVENING HOURS. WEAK FLOW WILL MAKE TIMING STORMS
FOR ANY PARTICULAR TERMINAL DIFFICULT...BUT ANTICIPATE OFF AND ON
STORMS IN THE VICINITY OF THE TERMINALS AFTER 18Z.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS REMAIN IN PLACE ACROSS THE FLORIDA
PENINSULA AND EASTERN GULF THE NEXT SEVERAL DAYS. A LIGHT GRADIENT
PROVIDES LOW WINDS AND SEAS THROUGH THE WEEKEND...OUTSIDE OF
SCATTERED THUNDERSTORMS. THUNDERSTORMS OVER THE WATER SHOULD BE MOST
NUMEROUS DURING THE LATE NIGHT AND EARLY MORNING HOURS.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS EXPECTED THROUGH THE UPCOMING
WEEKEND AS RELATIVE HUMIDITY VALUES REMAINS WELL ABOVE CRITICAL
LEVELS. THUNDERSTORMS LOOK TO BE QUITE NUMEROUS IN NATURE LATER THIS
AFTERNOON AND EARLY EVENING WITH LOCALLY HEAVY RAINFALL POSSIBLE.
WEAK TRANSPORT WINDS THE NEXT COUPLE OF DAYS SHOULD HELP KEEP
DISPERSION LEVELS RATHER LOW AS WELL. NO SIGNIFICANT FOG IS
EXPECTED...ALTHOUGH SOME PATCHY GROUND FOG IS POSSIBLE EACH NIGHT IN
LOCALIZED SPOTS THAT RECEIVE SIGNIFICANT LATE DAY RAINFALL.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 76 91 77 / 60 40 40 20
FMY 92 74 93 76 / 60 20 50 20
GIF 91 74 92 75 / 60 40 40 10
SRQ 89 75 91 75 / 50 40 30 20
BKV 91 72 92 73 / 50 40 40 20
SPG 90 78 90 79 / 50 40 40 20
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
MID TERM/LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
707 AM EDT FRI JUL 11 2014
.SYNOPSIS...
A WEAK STATIONARY FRONT WILL DISSIPATE NORTH OF THE AREA THROUGH
TONIGHT. ATLANTIC HIGH PRESSURE WILL BUILD IN OVER THE WEEKEND
INTO EARLY NEXT WEEK. THEN...A COLD FRONT WILL SLOWLY MOVE
SOUTHEAST THROUGH THE REGION TUESDAY THROUGH THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY FRIDAY MORNING...SOME HIGH RESOLUTION GUIDANCE INCLUDING THE
RUC13 AND THE HRRR SUGGEST THAT THE ONSET OF DIURNAL CONVECTION
COULD BE DELAYED A COUPLE OF HOURS INTO EARLY/MID AFTERNOON. GIVEN
THE PLUME OF PWATS AROUND 2 INCHES OVER THE REGION...HIGHEST
ALONG THE COAST...STILL FEEL THAT CONVECTION WILL BEGIN TO FIRE
BY LATE MORNING/MIDDAY. PER EARLY MORNING RADAR TRENDS AND TO
ACCOUNT FOR THE SUBTLE MODEL TREND TOWARD A SLIGHTLY LATER ONSET
OF THUNDERSTORMS... ADJUSTED HOURLY POPS THIS MORNING. OTHERWISE...
OVERALL FORECAST REASONING HAS NOT CHANGED.
EXPECT AN ACTIVE CONVECTION REGIME ACROSS THE FORECAST
AREA TODAY...PERHAPS FEATURING GREATER OVERALL COVERAGE AS
COMPARED WITH THURSDAY PM.
AS THE ENVIRONMENT WARMS/DESTABILIZES BY LATE MORNING/MIDDAY
ADDITIONAL SHOWERS/THUNDERSTORMS SHOULD READILY DEVELOP ALONG VARIOUS
BOUNDARIES...INCLUDING THE SEA BREEZE NEAR THE COAST AND
OUTFLOW LEFT BY OVERNIGHT CONVECTION ACROSS INLAND COUNTIES. THEN...
CONVECTION WILL INCREASE IN COVERAGE AS A COMPLEX OUTFLOW BOUNDARY
REGIME DEVELOPS THROUGH THE AFTERNOON.
MODEL GUIDANCE DIFFERS REGARDING THE FOCUS OF GREATEST
SHOWER/THUNDERSTORM COVERAGE. SOME GUIDANCE DEPICTS HIGHEST POPS
NEAR THE COAST...WHILE OTHER GUIDANCE DEPICTS GREATEST COVERAGE
INLAND AND STILL OTHER GUIDANCE MORE OR LESS SPLITS THE
DIFFERENCE. THE EARLY FRIDAY MORNING FORECAST INDICATES MAX POPS
HIGH CHANCE TO LIKELY...HIGHEST IN A SWATH CENTERED AROUND THE
I-95 CORRIDOR THIS AFTERNOON/EARLY EVENING.
HIGH PWATS AND THE POTENTIAL FOR BOUNDARY INTERACTIONS/LOCALLY
ENHANCED UPDRAFTS SUGGESTS A CHANCE FOR THE USUAL/ISOLATED PULSE
SEVERE EPISODES FEATURING DAMAGING WET MICROBURSTS. OF GREATER
CONCERN...PWATS EXCEEDING 2 INCHES AND THE POTENTIAL FOR
ERRATIC/SLOW THUNDERSTORM PROPAGATION WILL PRESENT THE CHANCE FOR
LOCALLY EXCESSIVE RAINFALL. WILL HIGHLIGHT THE POTENTIAL FOR
LOCALLY HEAVY RAIN WITHIN THE HAZARDOUS WEATHER OUTLOOK AND WILL
MENTION HEAVY RAIN WITHIN PUBLIC PRODUCTS.
CLOUDS/PRECIPITATION SHOULD HOLD TEMPERATURES BELOW LEVELS OF THE
PAST FEW DAYS...PERHAPS FALLING SHORT OF 90F AT KCHS/KSAV IF
THUNDERSTORMS FIRE EARLY. HOWEVER...WHERE THUNDERSTORMS ARE DELAYED
OR DO NOT OCCUR...TEMPERATURES SHOULD TOP OUT IN THE LOWER 90S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE ACTIVE CONVECTIVE REGIME SHOULD CONTINUE INTO THIS
EVENING...ESPECIALLY ACROSS SOUTHERN/INLAND COUNTIES...THEN
DIURNAL/PRECIPITATION STABILIZATION SHOULD TRANSLATE TO DIMINISHING
SHOWER/THUNDERSTORM COVERAGE. THEN...SOME GUIDANCE DEPICTS AN UPTICK
IN CONVECTION OVERNIGHT...ESPECIALLY EAST OF I-95/ALONG THE COAST
AND OVER ADJACENT COASTAL WATERS.
IF PRECIPITATION COVERAGE IS SUFFICIENT...PERHAPS PATCHY GROUND FOG
AND EVEN SOME STRATUS WILL DEVELOP OVERNIGHT. OTHERWISE...TEMPS
SHOULD BOTTOM OUT IN THE LOWER TO MID 70S MOST AREAS.
A BROAD UPPER LEVEL RIDGE WILL EXPAND TO THE EAST ON SATURDAY WHILE
SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTH. THE DRIER LOW-LEVEL
AIR LOOKS TO STAY JUST TO OUR NORTH...WHILE WE MAINTAIN 70+ SURFACE
DEWPOINTS IN PLACE WITH AN ONSHORE FLOW. A WEAK SURFACE TROUGH
ACROSS SOUTHEAST GA...COMBINED WITH A CONSIDERABLE SEA BREEZE AND
INCREASING MOISTURE CONVERGENCE SHOULD YIELD SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON. SLIGHTLY WARMER MID
LEVELS AND LESS CONVERGENCE ACROSS SOUTHERN SC MAY MAKE FOR MORE
ISOLATED COVERAGE. INLAND HIGHS WILL REACH THE LOWER 90S WHILE AREAS
CLOSER TO THE COAST MAY STRUGGLE TO HIT 90 DUE TO THE PREVAILING
ONSHORE FLOW.
BROAD UPPER RIDGING PERSISTS ON SUNDAY WHILE ATLANTIC HIGH PRESSURE
REBUILDS TO OUR EAST. DEEP LAYERED FLOW BECOMES SOUTHERLY DURING THE
AFTERNOON THOUGH A WEAK SURFACE TROUGH WILL PERSIST ACROSS SOUTHEAST
GA. MODELS SHOW THE GREATEST LOW-LEVEL INSTABILITY AGAIN ACROSS
INTERIOR SOUTHEAST GA COINCIDENT WITH THE TROUGH. SCATTERED SHOWERS
AND THUNDERSTORMS EXPECTED DURING THE HOURS OF PEAK HEATING...
ESPECIALLY INTERIOR AREAS WHERE THE SEA BREEZE ENCOUNTERS MODERATE
INSTABILITY DURING THE AFTERNOON. SLIGHT INCREASE IN HEIGHTS AND A
LATER SEA BREEZE SHOULD ALLOW FOR WARM TEMPS IN THE LOWER TO MIDDLE
90S.
THE UPPER RIDGE BREAKS DOWN SLIGHTLY ON MONDAY WITH LOW AND MID
LEVEL FLOW BECOMING MORE WEST TO SOUTHWESTERLY. AS THE ATLANTIC HIGH
BUILDS THE INLAND TROUGH SHOULD DISSIPATE. ALTHOUGH WE LOSE THE
SYNOPTIC SCALE CONVERGENCE AXIS...MOISTURE ADVECTION WILL PUSH PWATS
ABOVE 2.1 INCHES DURING THE AFTERNOON AND THICKNESSES WILL ALLOW
TEMPS TO RISE INTO THE LOW TO MIDDLE 90S YET AGAIN. THUS WE STILL
EXPECT SCATTERED SHOWERS AND TSTMS TO DEVELOP MAINLY DURING THE
AFTERNOON AND EVENING...ESPECIALLY ONCE THE SEA BREEZE SETS UP.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
MUCH OF NEXT WEEK WILL BE DOMINATED BY AN UNSEASONABLY STRONG UPPER
LEVEL TROUGH ACROSS THE CENTRAL UNITED STATES. A VERY DEEP SWLY FLOW
WILL PRECEDE A SLOW-MOVING COLD FRONT EXPECTED TO DRIFT THROUGH THE
AREA TUESDAY INTO WEDNESDAY. MODELS ARE IN SURPRISINGLY GOOD
AGREEMENT THROUGH WEDNESDAY...AFTER WHICH THEY DIVERGE WITH REGARD
TO HOW FAR OFFSHORE THE COLD FRONT PROGRESSES. MODEL PWATS HOVER
AROUND 2.2 INCHES TUESDAY INTO WEDNESDAY...WHICH COUPLED WITH A
SURFACE BOUNDARY AND MODERATE SURFACE HEATING WILL RESULT IN GOOD
COVERAGE OF SHOWERS/STORMS. HEAVY RAINFALL WILL DEFINITELY BE A
CONCERN GIVEN SUCH A MOIST ENVIRONMENT AND THE SLOW-MOVING FRONT. WE
BUMPED POPS UP TO AROUND 50 PERCENT.
THURSDAY INTO FRIDAY THE GFS HANGS THE FRONT ALONG THE COAST WHILE
THE ECMWF PUSHES IT FARTHER OFFSHORE WITH DRY HIGH PRESSURE BUILDING
FROM THE WEST. WE TOOK A COMPROMISE SOLUTION AND TONED DOWN POPS
DURING THE PERIOD BUT MAINTAINED AT LEAST ISOLATED COVERAGE.
EXCEPT FOR A WARMER DAY ON TUESDAY...THE REMAINDER OF THE PERIOD
WILL FEATURE HIGH TEMPS CLOSE TO 90.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR THIS MORNING. THEN...GUIDANCE POINTS TOWARD AN ACTIVE DAY FOR
SHOWERS/THUNDERSTORMS BEGINNING 15-18Z AND CONTINUING INTO THIS
EVENING. SOME THUNDERSTORMS WILL PRODUCE GUSTY WINDS AND BRIEF IFR
OR LOWER CONDITIONS IN HEAVY RAIN. 12Z TAFS WILL MAINTAIN ONGOING
VCTS ACCOMPANIED BY A 4 HOUR TEMPO PERIOD FOR DIRECT THUNDERSTORM
IMPACTS. HOWEVER...PRECISE TIMING/MAGNITUDE OF IMPACTS REMAIN
ELUSIVE...SO EXPECT AMENDMENTS AS DICTATED BY NEAR TERM CONVECTIVE
TRENDS THROUGH THE 12Z TAF PERIOD.
FLIGHT RESTRICTIONS COULD DEVELOP OVERNIGHT IF HEAVY RAIN OCCURS...
BUT FORECAST CONFIDENCE REMAINS TOO LOW TO WARRANT A MENTION
WITHIN 12Z TAFS.
EXTENDED AVIATION OUTLOOK...MAINLY VFR. BRIEF FLIGHT RESTRICTIONS
POSSIBLE DUE MAINLY TO AFTERNOON SHOWERS/THUNDERSTORMS WITH THE
GREATEST COVERAGE TUESDAY INTO WEDNESDAY.
&&
.MARINE...
A WEAK PRESSURE PATTERN AND THE PRESENCE OF BOUNDARIES...INCLUDING
THE LAND BREEZE BOUNDARY OVER COASTAL WATERS THIS MORNING...AND
OTHER FACTORS INCLUDING WATER TEMPS IN THE 80S...DEEP MOISTURE AND
LOW LCLS WILL SUPPORT THE POTENTIAL FOR ISOLATED WATERSPOUTS TODAY.
THE WEAK PRESSURE PATTERN WILL PREVAIL TODAY AND TONIGHT. AN EARLY
MORNING LAND BREEZE/OFFSHORE WINDS MAINLY 10 KT OR LESS WILL GIVE
WAY TO THE SEA BREEZE CIRCULATION/ONSHORE WINDS MAINLY 15 KT OR LESS
BY AFTERNOON. HOWEVER...EXPECTED THUNDERSTORMS/ASSOCIATED OUTFLOW
WILL GREATLY ALTER LOCAL WINDS THROUGH THE PERIOD. THUS...LOCAL
WINDS WILL OCCASIONALLY VARY SIGNIFICANTLY FROM DETERMINISTIC WIND
DIRECTION/SPEED FORECASTS PRESENTED WITHIN THE LATEST FORECAST
PACKAGE. SEAS WILL REMAIN IN THE 2-3 FT RANGE...PERHAPS AS HIGH AS
4 FT BEYOND 20 NM ESPECIALLY THIS MORNING.
SOUTHEAST FLOW ON SATURDAY BECOMES MORE SOUTHERLY SUNDAY INTO MONDAY
AS ATLANTIC HIGH PRESSURE GRADUALLY STRENGTHENS. THROUGH THE WEEKEND
THE AFTERNOON SEA BREEZE ALONG THE COAST AND WEAK NOCTURNAL SURGING
WILL BE THE MAIN FEATURES. MONDAY NIGHT THROUGH THURSDAY WE EXPECT
INCREASING SOUTH TO SOUTHWESTERLY FLOW AHEAD OF A SLOWLY ADVANCING
COLD FRONT. SUSTAINED WINDS OF 15-20 KT OVER THE COASTAL WATERS WITH
SEAS BUILDING AS HIGH AS 5 FT EXPECTED. THIS SHOULD REMAIN JUST
BELOW ADVISORY THRESHOLDS ALTHOUGH A SHORT-DURATION SMALL CRAFT
CANNOT BE COMPLETELY RULED OUT. WINDS IN CHARLESTON HARBOR WILL BE
GUSTY DURING THIS PERIOD DUE TO THE ENHANCED GRADIENT...AND A SMALL
CRAFT ADVISORY FOR A BEEFY AFTERNOON SEA BREEZE TUESDAY OR WEDNESDAY
IS NOT OUT OF THE QUESTION.
&&
.TIDES/COASTAL FLOODING...
ELEVATED TIDES COULD BRIEFLY EXCEED COASTAL FLOOD ADVISORY LEVELS
AROUND 8 PM THIS EVENING...BUT AS OF EARLY FRIDAY MORNING
DEPARTURES REMAIN SMALL. THUS...DO NOT PLAN TO ISSUE ANY
ADVISORIES THIS MORNING.
ASTRONOMICAL HIGH TIDES DUE TO THE FULL MOON/PERIGEE AND LIGHT TO
MODERATE ONSHORE WINDS COULD RESULT IN MINOR COASTAL FLOODING NEAR
THE TIMES OF HIGH TIDE DURING THE EVENING HOURS SATURDAY THROUGH EARLY
NEXT WEEK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...SPR
SHORT TERM...JRL/SPR
LONG TERM...JRL
AVIATION...JRL/SPR
MARINE...JRL/SPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
954 PM CDT SAT JUL 12 2014
.MESOSCALE DISCUSSION...
953 PM CDT
CLUSTER OF STORMS ACROSS NORTH CENTRAL IL CONTINUES TO SHOW STRONG
SIGNS OF ORGANIZATION WITH LIKELY SOME MESOSCALE CONVECTIVE VORTEX
(MCV) NOW HAVING DEVELOPED BASED ON RADAR IMAGERY. THIS HAS A
SLIGHT SOUTH OF EAST PROPAGATION WHICH FOLLOWS THE INSTABILITY
AXIS AND SURFACE BOUNDARY. CONTINUING TRENDS AND A STRENGTHENING
LOW-LEVEL JET PER VAD WIND PROFILER DATA SUPPORT SEVERE POTENTIAL
TOWARD THE FAR WESTERN CHICAGO METRO AREA BY 1030-1100PM AND THE
CENTRAL METRO BY MIDNIGHT.
THE PRIMARY THREAT WITH THIS WILL BE STRAIGHT-LINE WINDS HOWEVER
AN ISOLATED TORNADO THREAT IS IN PLACE GIVEN SURFACE BASED
CONVECTION POSSIBLE...AS THERE HAS BEEN GUSTINESS IN SURFACE
OBSERVATIONS AND ADAPTED SOUNDINGS INDICATE THE LFC IS VERY LOW
/BELOW 3000 FT/ ACROSS MUCH OF THE AREA. IN ADDITION...THE LOW-
LEVEL JET CONTINUES TO STRENGTHEN WITH LOW- LEVEL SHEAR AND
HELICITY BOTH HIGH IN PLACES WHERE LIFT CAN OCCUR FROM THE
SURFACE. THIS IS MOST FAVORED IN DISCRETE STORMS SUCH AS SEEN IN
HENRY AND MERCER COUNTY IN WESTERN IL. SOME OF THIS BEHAVIOR COULD
BE POSSIBLE IN A SMALL- SCALE WARM AIR ADVECTION WING AHEAD OF THE
CLUSTER OF STORMS IN NORTH CENTRAL IL.
DESPITE SOME QUICKER FORWARD PROGRESSION WITH A COMPLEX...FLASH
FLOODING THREAT CONTINUES WITH VERY EFFICIENT RAINFALL RATES.
MTF
&&
.DISCUSSION...
311 PM CDT
THIS AFTERNOON...
THE SURFACE LOW IS OVER NORTHERN MANITOBA AND THE UPPER LEVEL LOW IS
STACKED JUST ABOVE IT. STILL HAVE MOSTLY CLOUD SKIES WITH A FEW
BREAKS OF SUN AND WE ARE SLOWLY RECOVERING FROM THIS MORNING/S
CONVECTION. THE 18Z DVN SOUNDING FEATURED 1.7 INCHES OF PWAT AND
AROUND 1500 J/KG OF CAPE. THE SOUNDING ALSO HAD A STOUT CAP AT 850MB
WHICH MATCHES WELL WITH THE LATEST AMDAR SOUNDINGS. LAPSE RATES TO
950 MB WERE SURPRISINGLY STEEP GIVEN THE THICK CLOUD COVER. WITH THE
CAP IN PLACE AND SLOW RECOVERY NOT EXPECTING MUCH CONVECTIVE
ACTIVITY AHEAD OF THE MAIN LINE OF STORMS. IN GENERAL EXPECTING
CLOUDS TO CONTINUE THIN AND TEMPS RISE INTO THE MID 80S BY LATE THIS
AFTN. IT WILL CONTINUE TO BE MUGGY AS PWAT VALUES INCREASE TO
AROUND 2 INCHES.
THIS EVENING AND TONIGHT...
AN UPPER LEVEL SHORTWAVE CURRENTLY OVER IOWA WILL MOVE OVER THE CWA
THIS EVENING ADDING FORCING FOR STORMS. A SURFACE LOW IS OVER
NORTHERN MANITOBA AND ITS COLD FRONT STRETCHES FROM NORTHWEST
WISCONSIN THROUGH CENTRAL IOWA. A LINE OF STORMS WILL FORM ALONG
THE FRONT AND SLOWLY PUSH SOUTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. 850MB STEERING FLOW WILL BE WEST AT 30-40 KT AHEAD OF THE
LINE BUT ONLY AROUND 15 KT FROM THE NORTH BEHIND THE FRONT. TIMING
DIFFERS BETWEEN THE MODELS BUT THINKING A BLEND OF OUR LOCAL ARW AND
THE RAP LOOK REASONABLE. THE NAM LOOKS TOO FAST WHILE THE HRRR LOOKS
TOO SLOW.
THE LINE MAY PRODUCE SEVERE WIND GUSTS IN EXCESS OF 60 MPH...BUT THE
MAIN CONCERN WILL BE FLASH FLOODING. PWAT VALUES REMAIN HIGH AT
1.7-1.8 INCHES AND VALUES WILL INCREASE TO AROUND 2 INCHES BY THIS
EVENING. HAVE ISSUED A FLASH FLOOD WATCH FOR THE ENTIRE WARNING
AREA FOR THIS EVENING THROUGH TOMORROW MORNING. TOTAL RAINFALL FROM
THIS STORM WILL BE IN EXCESS OF 1 INCH. THE HIGHEST TOTALS WILL
LIKELY BE ALONG THE IL/WI STATE LINE WHERE RAINFALL TOTALS WILL
EASILY APPROACH 2 INCHES. IN ADDITION...SOME AREAS THIS MORNING
FROM COOK COUNTY SOUTH THROUGH PONTIAC AND GIBSON CITY SAW MULTIPLE
INCHES OF RAIN OVERNIGHT INTO THIS MORNING. THESE AREAS WILL BE THE
MOST SUSCEPTIBLE TO FLASH FLOODING AS WATER LEVELS ARE ALREADY
HIGH.
TEMPERATURES WILL QUICKLY FALL BEHIND THE LINE OF STORMS AND LOWS
WILL BE IN THE UPPER 60S TO LOWER 70S.
SUNDAY AND MONDAY...
THE UPPER LEVEL LOW SPLITS SUNDAY NIGHT AND THE FIRST TROUGH AXIS
MOVES THROUGH MONDAY NIGHT. AT THE SURFACE A SECOND COLD FRONT
MOVES THROUGH SUNDAY AND THEN STALLS OUT JUST SOUTH OF THE CWA
MONDAY MORNING. THE HIGHEST INSTABILITY VALUES WILL BE SOUTH OF I-80
SO ONLY HAVE A CHANCE OF STORMS SOUTH OF I-80. NOT EXPECTING MUCH IN
THE WAY OF PRECIP AT THIS TIME.
A BAND OF SHOWERS AND STORMS MAY FORM SUNDAY NIGHT FIRST ALONG THE
IL/WI STATE LINE AND THEN SPREAD SOUTH AS A VORTICITY STREAMER FROM
THE UPPER LEVEL LOW PUSHES SOUTH THROUGH THE REGION. THE SHOWERS
MAY PERSIST INTO LATE SUNDAY NIGHT AND BY THEN ONLY EXPECTING
SHOWERS. CONFIDENCE IS MEDIUM WITH THE STORMS DEVELOPING AND
COVERAGE.
YET ANOTHER COLD FRONT COMES THROUGH MONDAY AND HAVE A CHANCE OF
SHOWERS AND STORMS MONDAY AFTERNOON AND EVENING. THE BIGGER STORY
WILL BE THE COOL AIR THAT FOLLOWS THE COLD FRONT. HIGHS ON SUNDAY
WILL BE IN THE LOWER 80S WHILE MONDAY/S HIGHS WILL BE IN THE MID TO
UPPER 70S. MONDAY NIGHT LOOKS CRISP WITH LOWS IN THE LOWER 50S.
EXTENDED...TUESDAY THROUGH FRIDAY...
THE UPPER LEVEL TROUGH SLOWLY LIFTS NE THROUGH THURSDAY WHILE A
SURFACE HIGH BUILDS OVER THE REGION TUESDAY NIGHT. THE EXTENDED
LOOKS DRY WITH BELOW NORMAL TEMPERATURES.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* TSRA 0400Z-0700Z WITH IFR VISIBIILTY IN HEAVY RAIN AND GUSTY
WINDS AT THE LEADING EDGE.
* MVFR CIGS THROUGHOUT THE NIGHT WITH TEMPORARY IFR LIKELY DURING
THE TSRA.
* SMALL CHANCE FOR SHRA/TSRA LATE SUNDAY AFTERNOON/EARLY SUNDAY
EVE.
//DISCUSSION...UPDATED 03Z...
PREV DISCUSSION...UPDATED 00Z...
A SURFACE WARM FRONT IS DRAPED ACROSS NORTHERN IL...PRETTY NEAR THE
CHICAGO AREA TERMINALS. THIS WILL SERVE AS A FOCUS FOR STORMS AS
THE EVENING PROGRESSES...WITH STORMS LIKELY TO EXPAND EASTWARD
THROUGH MID-EVENING AS AN UPPER DISTURBANCE MOVES OVER THE AREA.
IT STILL REMAINS TRICKY TO TIME THE FIRST STORMS...BUT THE
GREATEST COVERAGE LOOKS TO BE THE TIMES WITH PREVAILING TSRA IN
THE TAFS. DUE TO A SUBSTANTIAL AMOUNT OF MOISTURE...HIGH RAINFALL
RATES AND LOW VISIBILITY...POTENTIALLY TO LIFR...IS TEMPORARILY
EXPECTED.
PATCHY MVFR CIGS HAVE BEEN SEEN ALONG AND NORTH OF THE WARM FRONT
AND THAT SHOULD CONTINUE UNTIL THE STORM ARRIVAL TIME. IN THE WAKE
OF THE STORMS...LINGERING MVFR CIGS MAY PERSIST FOR UP TO SEVERAL
HOURS.
WINDS ARE SOUTH-SOUTHWEST AT MUCH OF THE TAF SITES EARLY THIS
EVE AND THAT SHOULD CONTINUE. AS STORMS MOVE OVER...OF COURSE SOME
VARIABILITY CAN BE EXPECTED. A LARGE WELL-DEFINED COMPLEX OF
STORMS IS NOT EXPECTED...WHICH CAN SOMETIMES RESULT IN A SOUTHEAST
WIND AFTERWARD.
THE INITIAL COOL FRONT WILL MOVE THROUGH OVERNIGHT TURNING WINDS
TO THE NORTHWEST. A SECONDARY STRONGER ONE WILL MOVE THROUGH LATE
IN THE DAY SUNDAY. THIS COULD TRIGGER A FEW SHOWERS OR
STORMS...THOUGH THERE IS LIMITED FORCING.
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH IN TSRA TIMING. HIGH IN AT LEAST TEMPORARY IFR VISIBILITY
DURING THE TSRA.
* HIGH THAT MVFR CIGS WILL CONTINUE AFTER THE STORMS FOR AT LEAST
A COUPLE HOURS...WITH POSSIBLE IFR CIGS. LOW IN PRECISE
DEPARTURE TIME.
* LOW IN ANY SHRA/TSRA SUNDAY AFTERNOON/EARLY SUNDAY EVE.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF AFTERNOON TSRA.
TUESDAY...CHANCE OF SHRA.
WEDNESDAY-FRIDAY...VFR LIKELY.
MTF
&&
.MARINE...
423 PM CDT
SOUTHERLY FLOW PERSISTING OVER THE ENTIRE LAKE THIS AFTERNOON AS
HIGH PRESSURE REMAINS SITUATED OVER THE ATLANTIC COAST...AND AS A
TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE JUST
WEST OF THE LAKE. AS THESE SOUTHERLY WINDS BECOME MORE SOUTHWEST
AND THEN EVENTUALLY WEST TONIGHT WITH THE PASSAGE OF THIS
TROUGH...DO EXPECT SPEEDS TO REMAIN IN THE 10 TO 20 KT RANGE.
EXPECTED COMPLEX OF SHOWERS AND THUNDERSTORMS WILL LIKELY PROVIDE
ERRATIC WINDS LATER THIS EVENING AND OVERNIGHT...AS WELL AS THE
POSSIBILITY FOR SLIGHTLY HIGHER SPEEDS. DO EXPECT MORE OF A WEST
NORTHWEST WIND ACROSS THE LAKE ON SUNDAY...AS A SECONDARY
TROUGH/FRONT MOVE SOUTHEAST THROUGH THE GREAT LAKES REGION.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 PM SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
PM SUNDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
708 PM CDT SAT JUL 12 2014
.MESOSCALE DISCUSSION...
555 PM CDT
LOCAL AREA CONTINUES TO DESTABILIZE EARLY THIS EVENING...ESPECIALLY
ACROSS SOUTHWESTERN COUNTIES IN THE CWA WHERE PARTIAL CLEARING AND
STRONG SOUTHWEST WINDS HAVE ALLOWED TEMPERATURES TO WARM INTO THE
LOWER TO MID 80S WITH DEWPOINTS INTO THE MID 70S. FARTHER NORTH
AND NORTHEAST MORE EXTENSIVE CLOUD COVER HAS HAMPERED
DESTABILIZATION TO SOME DEGREE...HOWEVER 22Z AMDAR SOUNDING OUT OF
ORD PAIRED WITH NAM MOISTURE PROFILES INDICATES AROUND 1000 J/KG
MLCAPE WITH AROUND 100 J/KG MLCIN TO OVERCOME. THIS LINES UP WELL
WITH SPC MESOANALYSIS SHOWING THE CAP OVER THE NORTHEAST CORNER OF
IL WITH OVER 2000 J/KG MLCAPE OVER THE SOUTHWEST WHICH IS MOSTLY
UNCAPPED. SHEARED VORT LOBE IS DRIVING EAST ACROSS MN/IA AND WI
CURRENTLY AND HAS PROVIDED SOME BROAD SCALE ASCENT TO KICK OFF A
FEW THUNDERSTORMS ALONG A FRONTAL BOUNDARY THAT STRETCHES FROM
SOUTH CENTRAL IA TO NEAR THE QUAD CITIES WHERE PWATS HAVE POOLED
TO AROUND 2 INCHES. A CORRIDOR OF 40+ KT 0-6KM SHEAR WILL SUPPORT
ORGANIZED THUNDERSTORMS AS ALREADY EVIDENT BY THE SUPERCELL NORTH
OF THE QUAD CITIES. EXPECT LINE OF STORMS TO CONTINUE TO FILL IN
AS THE EVENING PROGRESSES WITH A STEADY FEED OF MOISTURE INTO THE
REGION AS 40-50 KT LOW LEVEL JET DEVELOPS LATER THIS EVENING
HELPING TO MAINTAIN THUNDERSTORMS THROUGH THE LATE EVENING AND
OVERNIGHT HOURS. AS PREVIOUSLY DISCUSSED...HEAVY RAIN AND STRONG
WINDS STILL APPEAR TO BE THE PRIMARY THREATS THIS EVENING AND
TONIGHT.
DEUBELBEISS
&&
.DISCUSSION...
311 PM CDT
THIS AFTERNOON...
THE SURFACE LOW IS OVER NORTHERN MANITOBA AND THE UPPER LEVEL LOW IS
STACKED JUST ABOVE IT. STILL HAVE MOSTLY CLOUD SKIES WITH A FEW
BREAKS OF SUN AND WE ARE SLOWLY RECOVERING FROM THIS MORNING/S
CONVECTION. THE 18Z DVN SOUNDING FEATURED 1.7 INCHES OF PWAT AND
AROUND 1500 J/KG OF CAPE. THE SOUNDING ALSO HAD A STOUT CAP AT 850MB
WHICH MATCHES WELL WITH THE LATEST AMDAR SOUNDINGS. LAPSE RATES TO
950 MB WERE SURPRISINGLY STEEP GIVEN THE THICK CLOUD COVER. WITH THE
CAP IN PLACE AND SLOW RECOVERY NOT EXPECTING MUCH CONVECTIVE
ACTIVITY AHEAD OF THE MAIN LINE OF STORMS. IN GENERAL EXPECTING
CLOUDS TO CONTINUE THIN AND TEMPS RISE INTO THE MID 80S BY LATE THIS
AFTN. IT WILL CONTINUE TO BE MUGGY AS PWAT VALUES INCREASE TO
AROUND 2 INCHES.
THIS EVENING AND TONIGHT...
AN UPPER LEVEL SHORTWAVE CURRENTLY OVER IOWA WILL MOVE OVER THE CWA
THIS EVENING ADDING FORCING FOR STORMS. A SURFACE LOW IS OVER
NORTHERN MANITOBA AND ITS COLD FRONT STRETCHES FROM NORTHWEST
WISCONSIN THROUGH CENTRAL IOWA. A LINE OF STORMS WILL FORM ALONG
THE FRONT AND SLOWLY PUSH SOUTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. 850MB STEERING FLOW WILL BE WEST AT 30-40 KT AHEAD OF THE
LINE BUT ONLY AROUND 15 KT FROM THE NORTH BEHIND THE FRONT. TIMING
DIFFERS BETWEEN THE MODELS BUT THINKING A BLEND OF OUR LOCAL ARW AND
THE RAP LOOK REASONABLE. THE NAM LOOKS TOO FAST WHILE THE HRRR LOOKS
TOO SLOW.
THE LINE MAY PRODUCE SEVERE WIND GUSTS IN EXCESS OF 60 MPH...BUT THE
MAIN CONCERN WILL BE FLASH FLOODING. PWAT VALUES REMAIN HIGH AT
1.7-1.8 INCHES AND VALUES WILL INCREASE TO AROUND 2 INCHES BY THIS
EVENING. HAVE ISSUED A FLASH FLOOD WATCH FOR THE ENTIRE WARNING
AREA FOR THIS EVENING THROUGH TOMORROW MORNING. TOTAL RAINFALL FROM
THIS STORM WILL BE IN EXCESS OF 1 INCH. THE HIGHEST TOTALS WILL
LIKELY BE ALONG THE IL/WI STATE LINE WHERE RAINFALL TOTALS WILL
EASILY APPROACH 2 INCHES. IN ADDITION...SOME AREAS THIS MORNING
FROM COOK COUNTY SOUTH THROUGH PONTIAC AND GIBSON CITY SAW MULTIPLE
INCHES OF RAIN OVERNIGHT INTO THIS MORNING. THESE AREAS WILL BE THE
MOST SUSCEPTIBLE TO FLASH FLOODING AS WATER LEVELS ARE ALREADY
HIGH.
TEMPERATURES WILL QUICKLY FALL BEHIND THE LINE OF STORMS AND LOWS
WILL BE IN THE UPPER 60S TO LOWER 70S.
SUNDAY AND MONDAY...
THE UPPER LEVEL LOW SPLITS SUNDAY NIGHT AND THE FIRST TROUGH AXIS
MOVES THROUGH MONDAY NIGHT. AT THE SURFACE A SECOND COLD FRONT
MOVES THROUGH SUNDAY AND THEN STALLS OUT JUST SOUTH OF THE CWA
MONDAY MORNING. THE HIGHEST INSTABILITY VALUES WILL BE SOUTH OF I-80
SO ONLY HAVE A CHANCE OF STORMS SOUTH OF I-80. NOT EXPECTING MUCH IN
THE WAY OF PRECIP AT THIS TIME.
A BAND OF SHOWERS AND STORMS MAY FORM SUNDAY NIGHT FIRST ALONG THE
IL/WI STATE LINE AND THEN SPREAD SOUTH AS A VORTICITY STREAMER FROM
THE UPPER LEVEL LOW PUSHES SOUTH THROUGH THE REGION. THE SHOWERS
MAY PERSIST INTO LATE SUNDAY NIGHT AND BY THEN ONLY EXPECTING
SHOWERS. CONFIDENCE IS MEDIUM WITH THE STORMS DEVELOPING AND
COVERAGE.
YET ANOTHER COLD FRONT COMES THROUGH MONDAY AND HAVE A CHANCE OF
SHOWERS AND STORMS MONDAY AFTERNOON AND EVENING. THE BIGGER STORY
WILL BE THE COOL AIR THAT FOLLOWS THE COLD FRONT. HIGHS ON SUNDAY
WILL BE IN THE LOWER 80S WHILE MONDAY/S HIGHS WILL BE IN THE MID TO
UPPER 70S. MONDAY NIGHT LOOKS CRISP WITH LOWS IN THE LOWER 50S.
EXTENDED...TUESDAY THROUGH FRIDAY...
THE UPPER LEVEL TROUGH SLOWLY LIFTS NE THROUGH THURSDAY WHILE A
SURFACE HIGH BUILDS OVER THE REGION TUESDAY NIGHT. THE EXTENDED
LOOKS DRY WITH BELOW NORMAL TEMPERATURES.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* SCATTERED TSRA BETWEEN 0130Z-0400Z WITH TSRA LIKELY LATE THIS
EVE INTO EARLY OVERNIGHT. TEMPORARY IFR VISIBILITY LIKELY WITHIN
STORMS AND POSSIBLE IFR.
* MVFR CIGS POSSIBLE THROUGHOUT THE NIGHT WITH TEMPORARY IFR
POSSIBLE DURING THE TSRA.
* SMALL CHANCE FOR SHRA/TSRA LATE SUNDAY AFTERNOON/EARLY SUNDAY
EVE.
//DISCUSSION...UPDATED 00Z...
A SURFACE WARM FRONT IS DRAPED ACROSS NORTHERN IL...PRETTY NEAR THE
CHICAGO AREA TERMINALS. THIS WILL SERVE AS A FOCUS FOR STORMS AS
THE EVENING PROGRESSES...WITH STORMS LIKELY TO EXPAND EASTWARD
THROUGH MID-EVENING AS AN UPPER DISTURBANCE MOVES OVER THE AREA.
IT STILL REMAINS TRICKY TO TIME THE FIRST STORMS...BUT THE
GREATEST COVERAGE LOOKS TO BE THE TIMES WITH PREVAILING TSRA IN
THE TAFS. DUE TO A SUBSTANTIAL AMOUNT OF MOISTURE...HIGH RAINFALL
RATES AND LOW VISIBILITY...POTENTIALLY TO LIFR...IS TEMPORARILY
EXPECTED.
PATCHY MVFR CIGS HAVE BEEN SEEN ALONG AND NORTH OF THE WARM FRONT
AND THAT SHOULD CONTINUE UNTIL THE STORM ARRIVAL TIME. IN THE WAKE
OF THE STORMS...LINGERING MVFR CIGS MAY PERSIST FOR UP TO SEVERAL
HOURS.
WINDS ARE SOUTH-SOUTHWEST AT MUCH OF THE TAF SITES EARLY THIS
EVE AND THAT SHOULD CONTINUE. AS STORMS MOVE OVER...OF COURSE SOME
VARIABILITY CAN BE EXPECTED. A LARGE WELL-DEFINED COMPLEX OF
STORMS IS NOT EXPECTED...WHICH CAN SOMETIMES RESULT IN A SOUTHEAST
WIND AFTERWARD.
THE INITIAL COOL FRONT WILL MOVE THROUGH OVERNIGHT TURNING WINDS
TO THE NORTHWEST. A SECONDARY STRONGER ONE WILL MOVE THROUGH LATE
IN THE DAY SUNDAY. THIS COULD TRIGGER A FEW SHOWERS OR
STORMS...THOUGH THERE IS LIMITED FORCING.
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* MEDIUM IN TSRA TIMING. HIGH IN AT LEAST TEMPORARY IFR VISIBILITY
DURING THE TSRA.
* HIGH IN MVFR CIGS REMAINING 1500 FT OR HIGHER OUTSIDE OF STORMS
THIS EVE. LOW IN DEPARTURE TIME OF MVFR CIGS LATE TONIGHT/SUNDAY
MORNING.
* LOW IN ANY SHRA/TSRA SUNDAY AFTERNOON/EARLY SUNDAY EVE.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF AFTERNOON TSRA.
TUESDAY...CHANCE OF SHRA.
WEDNESDAY-FRIDAY...VFR LIKELY.
MTF
&&
.MARINE...
423 PM CDT
SOUTHERLY FLOW PERSISTING OVER THE ENTIRE LAKE THIS AFTERNOON AS
HIGH PRESSURE REMAINS SITUATED OVER THE ATLANTIC COAST...AND AS A
TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE JUST
WEST OF THE LAKE. AS THESE SOUTHERLY WINDS BECOME MORE SOUTHWEST
AND THEN EVENTUALLY WEST TONIGHT WITH THE PASSAGE OF THIS
TROUGH...DO EXPECT SPEEDS TO REMAIN IN THE 10 TO 20 KT RANGE.
EXPECTED COMPLEX OF SHOWERS AND THUNDERSTORMS WILL LIKELY PROVIDE
ERRATIC WINDS LATER THIS EVENING AND OVERNIGHT...AS WELL AS THE
POSSIBILITY FOR SLIGHTLY HIGHER SPEEDS. DO EXPECT MORE OF A WEST
NORTHWEST WIND ACROSS THE LAKE ON SUNDAY...AS A SECONDARY
TROUGH/FRONT MOVE SOUTHEAST THROUGH THE GREAT LAKES REGION.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 PM SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
PM SUNDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1115 AM CDT FRI JUL 11 2014
.DISCUSSION...
259 AM CDT
TODAY...
LARGEST FOCUS FOR THE DAY WILL BE ON THE GRADUAL DEPARTURE TO THE
SFC RIDGE...WHICH GUIDANCE HAS SLOWED SLIGHTLY. THIS SHUD ALLOW FOR
A MOSTLY DRY DAY...HOWEVER AS THE EVENING PROGRESSES AND HIGHER DEW
PTS STEADILY ADVECT NORTH ACROSS THE FORECAST AREA...PRECIP CHANCES
WILL STEADILY INCREASE. AT THIS TIME CONFIDENCE IS HIGH THAT ANY
PRECIP WILL NOW HOLD OFF UNTIL AFT 00Z...SO HAVE PUSHED THE TIMING
BACK A FEW HOURS. THE THERMAL TROUGH THAT HELPED TO KEEP TEMPS DOWN
A FEW DEGREES WILL ALSO DEPART TODAY...HOWEVER CLOUDS WILL BE
STEADILY ON THE INCREASE THROUGHOUT THE AFTERNOON. BUT EXPECT TEMPS
REBOUNDING INTO THE UPR 70S TO LOW 80S. WINDS SHUD BE GENERALLY
SOUTHERLY...THE ONLY EXCEPTION COULD BE FAR NORTHEAST IL WHERE WINDS
MAY BE SLIGHTLY TURNED FROM THE SOUTHEAST AND USHER IN SLIGHTLY
COOLER AIR INTO NORTHEAST LAKE COUNTY.
TONIGHT THROUGH SATURDAY...
AS PREVIOUSLY NOTED...HAVE PUSHED BACK THE TIMING OF THE PRECIP
UNTIL AFT 00Z. SOME WEAK DIFFLUENCE IN THE MID-LVLS IS STILL
PRESENT...ALTHOUGH STEADILY WEAKENING AS THE EVENING PROGRESSES.
WARM/MOIST AIR WILL CONTINUE TO ADVECT NORTH INTO THE FORECAST
AREA...WITH SKIES BECOMING MOSTLY CLOUDY. INSTABILITY AT THE ONSET
IS NOT SIGNIFICANT...SO EXPECT THE LEADING EDGE OF THE PRECIP TO
PERHAPS NOT HAVE MUCH CONVECTION WITH IT. THIS WILL HOWEVER CHANGE
AS THE OVERNIGHT HOURS PROGRESS INTO SAT MORNING. HI-RES LCL ARW8KM
HAS FOR A FEW CYCLES BEEN SUGGESTIVE OF A LOBE OF VORTICITY SLIDING
EAST/SOUTHEAST ACROSS IA/CENTRAL IL AFT 09Z SAT THEN TURNING
SOUTHEAST. PWAT VALUES CONTINUE TO BE PROGGED AT 3 TO 4 SIGMA...OR
HOVERING AT 2" FOR MUCH OF THE FORECAST AREA. SO ANY CONVECTION THAT
DEVELOPS COULD EASILY PRODUCE SOME BRIEF HEAVY DOWNPOURS.
SAT MORNING MAY FEATURE A BRIEF LULL IN THE ACTIVITY...DESPITE THE
HIGH DEW PTS THAT WILL CONTINUE TO ADVECT NORTH/NORTHEAST ACROSS THE
REGION. A FEW SOLUTIONS HAVE CONTINUED TO POINT TOWARDS DEW PTS
NEARING THE MID 70S BY SAT AFTN. SO A VERY HUMID ENVIRONMENT IS IN
SHAPE FOR SAT...FORTUNATELY ABUNDANT CLOUD COVER WILL KEEP TEMPS
FROM GETTING TOO OUT OF CONTROL. THUS HAVE ONLY MADE MINOR
ADJUSTMENTS TO THE AFTN HIGHS...WHICH WILL GENERALLY BE IN THE
LOW/MID 80S.
THE FOCUS FOR ADDTL CONVECTIVE DEVELOPMENT WILL BE ON THE SHORTWAVE
PROGGED TO BE LIFTING INTO THE CENTRAL PLAINS SAT AFTN. THE MAIN
TROUGH AXIS WILL BE STARTING TO DIG INTO THE NORTHERN PLAINS SAT
AFTN/EVE...WHICH WILL AID IN INCREASING THE SOUTHWEST LLVL FLOW SAT
EVE FOR THE FORECAST AREA. THIS COUPLED WITH INCREASING
SHEAR...COULD AID IN THE POTENTIAL FOR STRONG TO PERHAPS SEVERE
STORMS TO DEVELOP SAT EVE. GENERAL STORM MOTION SHOULD BE WEST-EAST.
CONFIDENCE...MEDIUM/HIGH.
SUNDAY THROUGH THURSDAY...
FOCUS FOR THE SECOND HALF OF THE WEEKEND INTO NEXT WEEK WILL BE THE
UNSEASONABLY COOL WEATHER EXPECTED FOR NEXT WEEK. ALTHOUGH PRIOR TO
THE ARRIVAL...SUN WILL FEATURE A COUPLE BOUNDARIES PUSHING EAST
ACROSS THE REGION. A WEAK BOUNDARY SHUD BE ORIENTED FROM NORTHERN MO
STRETCHING NORTHEAST THRU SOUTHERN MI...WITH A SECONDARY WAVE
APPROACHING THE REGION LATE SUN NGT/EARLY MON. THE 500MB VORT WILL
BE ARRIVING OVER THE UPPER MIDWEST LATE SUN...WITH A FEW WEAK LOBES
OF VORTICITY PIVOTING ARND THE AXIS. 850MB THERMAL TROUGH WILL ONLY
CONTINUE TO COOL AS TIME PROGRESSES...AND EXPECT BY TUE TEMPS ALOFT
TO NEAR -3 SIGMA. ENSEMBLES HAVE MAINTAINED A HIGH CONFIDENCE WITH
MINIMAL SPREAD FOR NUMEROUS CYCLES. BASED ON THE PATTERN OF A HIGH
AMPLITUDE RIDGE DEVELOPING ACROSS THE WESTERN CONUS/CANADA...THIS
WILL TRANSLATE INTO A DEEP/STRONG TROUGH FOR THE GREAT LAKES. EXPECT
TEMPS TUE TO STRUGGLE TO WARM BEYOND THE UPR 60S FOR SOME LOCATIONS
NORTH OF I-80...AND PERHAPS ARND 70 ELSEWHERE.
AS THE EXTENDED PERIODS PROGRESS...THE POTENCY OF THE TROUGH BEGINS
TO MODERATE AND TEMPS START TO WARM GENERALLY INTO THE MID 70S WITH
BROAD SFC RIDGING BUILDING IN.
CONFIDENCE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* POTENTIAL FOR A LAKE BREEZE THIS AFTERNOON.
* TSRA LATER TONIGHT WITH MVFR/IFR POSSIBLE.
* MVFR CONDITIONS AFTER TSRA NEAR DAYBREAK SATURDAY.
MDB
//DISCUSSION...UPDATED 16Z...
BAND OF SPRINKLES AND MAYBE A FEW SHOWERS CONTINUES TO MOVE ACROSS
NORTHWEST AND INTO NORTH-CENTRAL ILLINOIS. THIS MAY BRING
SPRINKLES OR A LIGHT SHOWER TO RFD BY MIDDAY BUT THAT MAY BE TOO
PESSIMISTIC. OTHERWISE...WINDS ARE STARTING TO INCREASE IN SPEED
ACROSS NORTH CENTRAL ILLINOIS WITH MORE VARIABILITY ACROSS THE
CHICAGO AREA AND NW INDIANA. STILL APPEARS THE TREND FOR THESE
AREAS WILL BE TO END UP SOUTH-SOUTHEAST WITH A LAKE BREEZE STAYING
EAST OF ORD/MDW...THOUGH GYY MAY SEE MORE OF AN EASTERLY SHIFT
THAN CURRENTLY INDICATED. MID AND HIGH CLOUD COVER WILL CONTINUE
TO INCREASE.
MDB
FROM 12Z...
BENIGN CONDITIONS THIS MORNING ACROSS THE TERMINALS AS HIGH
PRESSURE SHIFTS EAST OF THE AREA RESULTING IN LIGHT SSE WINDS.
WINDS WILL GRADUALLY PICK UP OUT OF THE SOUTH FROM WEST TO EAST AS
THE GRADIENT INCREASES. LAKE BREEZE IS THE FIRST CHALLENGE IN THIS
TAF PACKAGE. CONCERN IS THAT THE GRADIENT WILL NOT BE STRONG
ENOUGH TO PREVENT THE LAKE BREEZE FROM MAKING IT TO MDW AND
POSSIBLY ORD. THERE IS MIXED SIGNALS IN HIGH RESOLUTION
GUIDANCE...AS THE HRRR BRINGS THE LAKE BREEZE THROUGH BOTH ORD AND
MDW...WHILE MOST OTHER GUIDANCE BRINGS IT CLOSE BEFORE LOWER LEVEL
SOUTHERLY WINDS PICK UP. WILL CONTINUE WITH CURRENT THINKING THAT
IT WILL GET TO MDW AND NOT QUITE TO ORD BUT CONFIDENCE ON THIS IS
NOT SUPER HIGH.
ONCE SOUTHERLY WINDS PICK UP AND LIMIT THE LAKE BREEZE...CONCERN
SHIFTS TO THUNDERSTORM ACTIVITY LATER TONIGHT. HAVE GONE WITH
PROB30 TSRA AS CONFIDENCE IS NOT HIGH ON THE TIMING AT THIS POINT
AND IT COULD ACTUALLY BE A LITTLE SOONER THAN IN THE CURRENT
FORECAST. IT LOOKS LIKE SHOWERS WITH EMBEDDED THUNDER AS
INSTABILITY IS NOT ALL THAT HIGH. AFTER THUNDERSTORM ACTIVITY
CLEARS...EXPECT LINGERING LOW LEVEL MOISTURE AND A LIGHT GRADIENT
WILL RESULT IN MVFR CIGS FOR A TIME.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW CONFIDENCE IN LAKE BREEZE REACHING ORD TODAY...LOW TO
MEDIUM CONFIDENCE IN GETTING VERY CLOSE TO MDW.
* MEDIUM CONFIDENCE IN TSRA IMPACTING THE TERMINALS LATE
TONIGHT...BUT LOW CONFIDENCE ON TIMING.
* MEDIUM CONFIDENCE ON MVFR CIGS FOLLOWING TSRA...BUT LOW
CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...TSRA WITH MVFR/IFR POSSIBLE.
SUNDAY THROUGH TUESDAY...PERIODIC CHANCES FOR TSRA/SHRA. PRIMARILY VFR.
WEDNESDAY THROUGH THURSDAY...SMALL CHANCES FOR SHRA. PRIMARILY VFR.
KMD
&&
.MARINE...
332 AM CDT
HIGH PRESSURE HAS SHIFTED TO THE EASTERN GREAT LAKES EARLY THIS
MORNING...AND WINDS HAVE TURNED MORE SOUTHERLY ACROSS THE LAKE.
EXPECT SPEEDS TO INCREASE TODAY IN RESPONSE TO A STRONGER GRADIENT
CREATED BY LOW PRESSURE CENTERED IN NORTHERN MANITOBA AND INTO THE
NORTHERN PLAINS. THE STRONGER GRADIENT WILL BE OVER THE NORTHERN
HALF OF THE LAKE...WHERE SOUTH WINDS INCREASE TO 15 TO 25 KT...WHILE
THE SOUTH HALF WILL SEE S TO SE WINDS AT 10-20 KT. WINDS DIMINISH
SATURDAY AS A TROUGH OF LOW PRESSURE MOVES OVERHEAD AND BECOME
SOUTHWEST SATURDAY NIGHT.
A LOW PASSES WELL NORTH OF THE LAKE SATURDAY NIGHT AND SUNDAY AND
ITS COLD FRONT SWINGS OVER THE LAKE SUNDAY MORNING. WINDS BECOME
WEST BEHIND THE FRONT MAINLY FOR THE NORTHERN HALF...AND THEN A
SECOND FRONT PUSHES DOWN THE LAKE SUNDAY NIGHT INTO MONDAY BEFORE
FINALLY CLEARING THE LAKE MONDAY EVENING. WINDS WILL BECOME NORTH
TO NORTHWEST 10-20 KT BEHIND THE FRONT. WINDS DIMINISH LATE TUESDAY
NIGHT AND THEN HIGH PRESSURE MOVES OVER THE LAKE WEDNESDAY NIGHT.
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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
900 AM CDT FRI JUL 11 2014
.DISCUSSION...
259 AM CDT
TODAY...
LARGEST FOCUS FOR THE DAY WILL BE ON THE GRADUAL DEPARTURE TO THE
SFC RIDGE...WHICH GUIDANCE HAS SLOWED SLIGHTLY. THIS SHUD ALLOW FOR
A MOSTLY DRY DAY...HOWEVER AS THE EVENING PROGRESSES AND HIGHER DEW
PTS STEADILY ADVECT NORTH ACROSS THE FORECAST AREA...PRECIP CHANCES
WILL STEADILY INCREASE. AT THIS TIME CONFIDENCE IS HIGH THAT ANY
PRECIP WILL NOW HOLD OFF UNTIL AFT 00Z...SO HAVE PUSHED THE TIMING
BACK A FEW HOURS. THE THERMAL TROUGH THAT HELPED TO KEEP TEMPS DOWN
A FEW DEGREES WILL ALSO DEPART TODAY...HOWEVER CLOUDS WILL BE
STEADILY ON THE INCREASE THROUGHOUT THE AFTERNOON. BUT EXPECT TEMPS
REBOUNDING INTO THE UPR 70S TO LOW 80S. WINDS SHUD BE GENERALLY
SOUTHERLY...THE ONLY EXCEPTION COULD BE FAR NORTHEAST IL WHERE WINDS
MAY BE SLIGHTLY TURNED FROM THE SOUTHEAST AND USHER IN SLIGHTLY
COOLER AIR INTO NORTHEAST LAKE COUNTY.
TONIGHT THROUGH SATURDAY...
AS PREVIOUSLY NOTED...HAVE PUSHED BACK THE TIMING OF THE PRECIP
UNTIL AFT 00Z. SOME WEAK DIFFLUENCE IN THE MID-LVLS IS STILL
PRESENT...ALTHOUGH STEADILY WEAKENING AS THE EVENING PROGRESSES.
WARM/MOIST AIR WILL CONTINUE TO ADVECT NORTH INTO THE FORECAST
AREA...WITH SKIES BECOMING MOSTLY CLOUDY. INSTABILITY AT THE ONSET
IS NOT SIGNIFICANT...SO EXPECT THE LEADING EDGE OF THE PRECIP TO
PERHAPS NOT HAVE MUCH CONVECTION WITH IT. THIS WILL HOWEVER CHANGE
AS THE OVERNIGHT HOURS PROGRESS INTO SAT MORNING. HI-RES LCL ARW8KM
HAS FOR A FEW CYCLES BEEN SUGGESTIVE OF A LOBE OF VORTICITY SLIDING
EAST/SOUTHEAST ACROSS IA/CENTRAL IL AFT 09Z SAT THEN TURNING
SOUTHEAST. PWAT VALUES CONTINUE TO BE PROGGED AT 3 TO 4 SIGMA...OR
HOVERING AT 2" FOR MUCH OF THE FORECAST AREA. SO ANY CONVECTION THAT
DEVELOPS COULD EASILY PRODUCE SOME BRIEF HEAVY DOWNPOURS.
SAT MORNING MAY FEATURE A BRIEF LULL IN THE ACTIVITY...DESPITE THE
HIGH DEW PTS THAT WILL CONTINUE TO ADVECT NORTH/NORTHEAST ACROSS THE
REGION. A FEW SOLUTIONS HAVE CONTINUED TO POINT TOWARDS DEW PTS
NEARING THE MID 70S BY SAT AFTN. SO A VERY HUMID ENVIRONMENT IS IN
SHAPE FOR SAT...FORTUNATELY ABUNDANT CLOUD COVER WILL KEEP TEMPS
FROM GETTING TOO OUT OF CONTROL. THUS HAVE ONLY MADE MINOR
ADJUSTMENTS TO THE AFTN HIGHS...WHICH WILL GENERALLY BE IN THE
LOW/MID 80S.
THE FOCUS FOR ADDTL CONVECTIVE DEVELOPMENT WILL BE ON THE SHORTWAVE
PROGGED TO BE LIFTING INTO THE CENTRAL PLAINS SAT AFTN. THE MAIN
TROUGH AXIS WILL BE STARTING TO DIG INTO THE NORTHERN PLAINS SAT
AFTN/EVE...WHICH WILL AID IN INCREASING THE SOUTHWEST LLVL FLOW SAT
EVE FOR THE FORECAST AREA. THIS COUPLED WITH INCREASING
SHEAR...COULD AID IN THE POTENTIAL FOR STRONG TO PERHAPS SEVERE
STORMS TO DEVELOP SAT EVE. GENERAL STORM MOTION SHOULD BE WEST-EAST.
CONFIDENCE...MEDIUM/HIGH.
SUNDAY THROUGH THURSDAY...
FOCUS FOR THE SECOND HALF OF THE WEEKEND INTO NEXT WEEK WILL BE THE
UNSEASONABLY COOL WEATHER EXPECTED FOR NEXT WEEK. ALTHOUGH PRIOR TO
THE ARRIVAL...SUN WILL FEATURE A COUPLE BOUNDARIES PUSHING EAST
ACROSS THE REGION. A WEAK BOUNDARY SHUD BE ORIENTED FROM NORTHERN MO
STRETCHING NORTHEAST THRU SOUTHERN MI...WITH A SECONDARY WAVE
APPROACHING THE REGION LATE SUN NGT/EARLY MON. THE 500MB VORT WILL
BE ARRIVING OVER THE UPPER MIDWEST LATE SUN...WITH A FEW WEAK LOBES
OF VORTICITY PIVOTING ARND THE AXIS. 850MB THERMAL TROUGH WILL ONLY
CONTINUE TO COOL AS TIME PROGRESSES...AND EXPECT BY TUE TEMPS ALOFT
TO NEAR -3 SIGMA. ENSEMBLES HAVE MAINTAINED A HIGH CONFIDENCE WITH
MINIMAL SPREAD FOR NUMEROUS CYCLES. BASED ON THE PATTERN OF A HIGH
AMPLITUDE RIDGE DEVELOPING ACROSS THE WESTERN CONUS/CANADA...THIS
WILL TRANSLATE INTO A DEEP/STRONG TROUGH FOR THE GREAT LAKES. EXPECT
TEMPS TUE TO STRUGGLE TO WARM BEYOND THE UPR 60S FOR SOME LOCATIONS
NORTH OF I-80...AND PERHAPS ARND 70 ELSEWHERE.
AS THE EXTENDED PERIODS PROGRESS...THE POTENCY OF THE TROUGH BEGINS
TO MODERATE AND TEMPS START TO WARM GENERALLY INTO THE MID 70S WITH
BROAD SFC RIDGING BUILDING IN.
CONFIDENCE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* POTENTIAL FOR A LAKE BREEZE THIS AFTERNOON.
* TSRA LATER TONIGHT WITH MVFR/IFR POSSIBLE.
* MVFR CONDITIONS AFTER TSRA NEAR DAYBREAK SATURDAY.
MDB
//DISCUSSION...UPDATED 14Z...
NOT MUCH CHANGE IN FORECAST THINKING WITH REGARD TO WINDS FOR
TODAY.
MDB
FROM 12Z...
BENIGN CONDITIONS THIS MORNING ACROSS THE TERMINALS AS HIGH
PRESSURE SHIFTS EAST OF THE AREA RESULTING IN LIGHT SSE WINDS.
WINDS WILL GRADUALLY PICK UP OUT OF THE SOUTH FROM WEST TO EAST AS
THE GRADIENT INCREASES. LAKE BREEZE IS THE FIRST CHALLENGE IN THIS
TAF PACKAGE. CONCERN IS THAT THE GRADIENT WILL NOT BE STRONG
ENOUGH TO PREVENT THE LAKE BREEZE FROM MAKING IT TO MDW AND
POSSIBLY ORD. THERE IS MIXED SIGNALS IN HIGH RESOLUTION
GUIDANCE...AS THE HRRR BRINGS THE LAKE BREEZE THROUGH BOTH ORD AND
MDW...WHILE MOST OTHER GUIDANCE BRINGS IT CLOSE BEFORE LOWER LEVEL
SOUTHERLY WINDS PICK UP. WILL CONTINUE WITH CURRENT THINKING THAT
IT WILL GET TO MDW AND NOT QUITE TO ORD BUT CONFIDENCE ON THIS IS
NOT SUPER HIGH.
ONCE SOUTHERLY WINDS PICK UP AND LIMIT THE LAKE BREEZE...CONCERN
SHIFTS TO THUNDERSTORM ACTIVITY LATER TONIGHT. HAVE GONE WITH
PROB30 TSRA AS CONFIDENCE IS NOT HIGH ON THE TIMING AT THIS POINT
AND IT COULD ACTUALLY BE A LITTLE SOONER THAN IN THE CURRENT
FORECAST. IT LOOKS LIKE SHOWERS WITH EMBEDDED THUNDER AS
INSTABILITY IS NOT ALL THAT HIGH. AFTER THUNDERSTORM ACTIVITY
CLEARS...EXPECT LINGERING LOW LEVEL MOISTURE AND A LIGHT GRADIENT
WILL RESULT IN MVFR CIGS FOR A TIME.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* LOW CONFIDENCE IN LAKE BREEZE REACHING ORD TODAY...LOW TO
MEDIUM CONFIDENCE IN GETTING VERY CLOSE TO MDW.
* MEDIUM CONFIDENCE IN TSRA IMPACTING THE TERMINALS LATE
TONIGHT...BUT LOW CONFIDENCE ON TIMING.
* MEDIUM CONFIDENCE ON MVFR CIGS FOLLOWING TSRA...BUT LOW
CONFIDENCE ON TIMING.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...TSRA WITH MVFR/IFR POSSIBLE.
SUNDAY THROUGH TUESDAY...PERIODIC CHANCES FOR TSRA/SHRA. PRIMARILY VFR.
WEDNESDAY THROUGH THURSDAY...SMALL CHANCES FOR SHRA. PRIMARILY VFR.
KMD
&&
.MARINE...
332 AM CDT
HIGH PRESSURE HAS SHIFTED TO THE EASTERN GREAT LAKES EARLY THIS
MORNING...AND WINDS HAVE TURNED MORE SOUTHERLY ACROSS THE LAKE.
EXPECT SPEEDS TO INCREASE TODAY IN RESPONSE TO A STRONGER GRADIENT
CREATED BY LOW PRESSURE CENTERED IN NORTHERN MANITOBA AND INTO THE
NORTHERN PLAINS. THE STRONGER GRADIENT WILL BE OVER THE NORTHERN
HALF OF THE LAKE...WHERE SOUTH WINDS INCREASE TO 15 TO 25 KT...WHILE
THE SOUTH HALF WILL SEE S TO SE WINDS AT 10-20 KT. WINDS DIMINISH
SATURDAY AS A TROUGH OF LOW PRESSURE MOVES OVERHEAD AND BECOME
SOUTHWEST SATURDAY NIGHT.
A LOW PASSES WELL NORTH OF THE LAKE SATURDAY NIGHT AND SUNDAY AND
ITS COLD FRONT SWINGS OVER THE LAKE SUNDAY MORNING. WINDS BECOME
WEST BEHIND THE FRONT MAINLY FOR THE NORTHERN HALF...AND THEN A
SECOND FRONT PUSHES DOWN THE LAKE SUNDAY NIGHT INTO MONDAY BEFORE
FINALLY CLEARING THE LAKE MONDAY EVENING. WINDS WILL BECOME NORTH
TO NORTHWEST 10-20 KT BEHIND THE FRONT. WINDS DIMINISH LATE TUESDAY
NIGHT AND THEN HIGH PRESSURE MOVES OVER THE LAKE WEDNESDAY NIGHT.
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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
644 AM CDT FRI JUL 11 2014
.DISCUSSION...
259 AM CDT
TODAY...
LARGEST FOCUS FOR THE DAY WILL BE ON THE GRADUAL DEPARTURE TO THE
SFC RIDGE...WHICH GUIDANCE HAS SLOWED SLIGHTLY. THIS SHUD ALLOW FOR
A MOSTLY DRY DAY...HOWEVER AS THE EVENING PROGRESSES AND HIGHER DEW
PTS STEADILY ADVECT NORTH ACROSS THE FORECAST AREA...PRECIP CHANCES
WILL STEADILY INCREASE. AT THIS TIME CONFIDENCE IS HIGH THAT ANY
PRECIP WILL NOW HOLD OFF UNTIL AFT 00Z...SO HAVE PUSHED THE TIMING
BACK A FEW HOURS. THE THERMAL TROUGH THAT HELPED TO KEEP TEMPS DOWN
A FEW DEGREES WILL ALSO DEPART TODAY...HOWEVER CLOUDS WILL BE
STEADILY ON THE INCREASE THROUGHOUT THE AFTERNOON. BUT EXPECT TEMPS
REBOUNDING INTO THE UPR 70S TO LOW 80S. WINDS SHUD BE GENERALLY
SOUTHERLY...THE ONLY EXCEPTION COULD BE FAR NORTHEAST IL WHERE WINDS
MAY BE SLIGHTLY TURNED FROM THE SOUTHEAST AND USHER IN SLIGHTLY
COOLER AIR INTO NORTHEAST LAKE COUNTY.
TONIGHT THROUGH SATURDAY...
AS PREVIOUSLY NOTED...HAVE PUSHED BACK THE TIMING OF THE PRECIP
UNTIL AFT 00Z. SOME WEAK DIFFLUENCE IN THE MID-LVLS IS STILL
PRESENT...ALTHOUGH STEADILY WEAKENING AS THE EVENING PROGRESSES.
WARM/MOIST AIR WILL CONTINUE TO ADVECT NORTH INTO THE FORECAST
AREA...WITH SKIES BECOMING MOSTLY CLOUDY. INSTABILITY AT THE ONSET
IS NOT SIGNIFICANT...SO EXPECT THE LEADING EDGE OF THE PRECIP TO
PERHAPS NOT HAVE MUCH CONVECTION WITH IT. THIS WILL HOWEVER CHANGE
AS THE OVERNIGHT HOURS PROGRESS INTO SAT MORNING. HI-RES LCL ARW8KM
HAS FOR A FEW CYCLES BEEN SUGGESTIVE OF A LOBE OF VORTICITY SLIDING
EAST/SOUTHEAST ACROSS IA/CENTRAL IL AFT 09Z SAT THEN TURNING
SOUTHEAST. PWAT VALUES CONTINUE TO BE PROGGED AT 3 TO 4 SIGMA...OR
HOVERING AT 2" FOR MUCH OF THE FORECAST AREA. SO ANY CONVECTION THAT
DEVELOPS COULD EASILY PRODUCE SOME BRIEF HEAVY DOWNPOURS.
SAT MORNING MAY FEATURE A BRIEF LULL IN THE ACTIVITY...DESPITE THE
HIGH DEW PTS THAT WILL CONTINUE TO ADVECT NORTH/NORTHEAST ACROSS THE
REGION. A FEW SOLUTIONS HAVE CONTINUED TO POINT TOWARDS DEW PTS
NEARING THE MID 70S BY SAT AFTN. SO A VERY HUMID ENVIRONMENT IS IN
SHAPE FOR SAT...FORTUNATELY ABUNDANT CLOUD COVER WILL KEEP TEMPS
FROM GETTING TOO OUT OF CONTROL. THUS HAVE ONLY MADE MINOR
ADJUSTMENTS TO THE AFTN HIGHS...WHICH WILL GENERALLY BE IN THE
LOW/MID 80S.
THE FOCUS FOR ADDTL CONVECTIVE DEVELOPMENT WILL BE ON THE SHORTWAVE
PROGGED TO BE LIFTING INTO THE CENTRAL PLAINS SAT AFTN. THE MAIN
TROUGH AXIS WILL BE STARTING TO DIG INTO THE NORTHERN PLAINS SAT
AFTN/EVE...WHICH WILL AID IN INCREASING THE SOUTHWEST LLVL FLOW SAT
EVE FOR THE FORECAST AREA. THIS COUPLED WITH INCREASING
SHEAR...COULD AID IN THE POTENTIAL FOR STRONG TO PERHAPS SEVERE
STORMS TO DEVELOP SAT EVE. GENERAL STORM MOTION SHOULD BE WEST-EAST.
CONFIDENCE...MEDIUM/HIGH.
SUNDAY THROUGH THURSDAY...
FOCUS FOR THE SECOND HALF OF THE WEEKEND INTO NEXT WEEK WILL BE THE
UNSEASONABLY COOL WEATHER EXPECTED FOR NEXT WEEK. ALTHOUGH PRIOR TO
THE ARRIVAL...SUN WILL FEATURE A COUPLE BOUNDARIES PUSHING EAST
ACROSS THE REGION. A WEAK BOUNDARY SHUD BE ORIENTED FROM NORTHERN MO
STRETCHING NORTHEAST THRU SOUTHERN MI...WITH A SECONDARY WAVE
APPROACHING THE REGION LATE SUN NGT/EARLY MON. THE 500MB VORT WILL
BE ARRIVING OVER THE UPPER MIDWEST LATE SUN...WITH A FEW WEAK LOBES
OF VORTICITY PIVOTING ARND THE AXIS. 850MB THERMAL TROUGH WILL ONLY
CONTINUE TO COOL AS TIME PROGRESSES...AND EXPECT BY TUE TEMPS ALOFT
TO NEAR -3 SIGMA. ENSEMBLES HAVE MAINTAINED A HIGH CONFIDENCE WITH
MINIMAL SPREAD FOR NUMEROUS CYCLES. BASED ON THE PATTERN OF A HIGH
AMPLITUDE RIDGE DEVELOPING ACROSS THE WESTERN CONUS/CANADA...THIS
WILL TRANSLATE INTO A DEEP/STRONG TROUGH FOR THE GREAT LAKES. EXPECT
TEMPS TUE TO STRUGGLE TO WARM BEYOND THE UPR 60S FOR SOME LOCATIONS
NORTH OF I-80...AND PERHAPS ARND 70 ELSEWHERE.
AS THE EXTENDED PERIODS PROGRESS...THE POTENCY OF THE TROUGH BEGINS
TO MODERATE AND TEMPS START TO WARM GENERALLY INTO THE MID 70S WITH
BROAD SFC RIDGING BUILDING IN.
CONFIDENCE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* POTENTIAL FOR A LAKE BREEZE THIS AFTERNOON
* TSRA LATER TONIGHT WITH MVFR/IFR POSSIBLE
* MVFR CONDITIONS AFTER TSRA NEAR DAYBREAK SATURDAY
KMD
//DISCUSSION...UPDATED 12Z...
BENIGN CONDITIONS THIS MORNING ACROSS THE TERMINALS AS HIGH
PRESSURE SHIFTS EAST OF THE AREA RESULTING IN LIGHT SSE WINDS.
WINDS WILL GRADUALLY PICK UP OUT OF THE SOUTH FROM WEST TO EAST AS
THE GRADIENT INCREASES. LAKE BREEZE IS THE FIRST CHALLENGE IN THIS
TAF PACKAGE. CONCERN IS THAT THE GRADIENT WILL NOT BE STRONG
ENOUGH TO PREVENT THE LAKE BREEZE FROM MAKING IT TO MDW AND
POSSIBLY ORD. THERE IS MIXED SIGNALS IN HIGH RESOLUTION
GUIDANCE...AS THE HRRR BRINGS THE LAKE BREEZE THROUGH BOTH ORD AND
MDW...WHILE MOST OTHER GUIDANCE BRINGS IT CLOSE BEFORE LOWER LEVEL
SOUTHERLY WINDS PICK UP. WILL CONTINUE WITH CURRENT THINKING THAT
IT WILL GET TO MDW AND NOT QUITE TO ORD BUT CONFIDENCE ON THIS IS
NOT SUPER HIGH.
ONCE SOUTHERLY WINDS PICK UP AND LIMIT THE LAKE BREEZE...CONCERN
SHIFTS TO THUNDERSTORM ACTIVITY LATER TONIGHT. HAVE GONE WITH
PROB30 TSRA AS CONFIDENCE IS NOT HIGH ON THE TIMING AT THIS POINT
AND IT COULD ACTUALLY BE A LITTLE SOONER THAN IN THE CURRENT
FORECAST. IT LOOKS LIKE SHOWERS WITH EMBEDDED THUNDER AS
INSTABILITY IS NOT ALL THAT HIGH. AFTER THUNDERSTORM ACTIVITY
CLEARS...EXPECT LINGERING LOW LEVEL MOISTURE AND A LIGHT GRADIENT
WILL RESULT IN MVFR CIGS FOR A TIME.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* LOW CONFIDENCE IN LAKE BREEZE REACHING ORD FRIDAY...LOW TO
MEDIUM CONFIDENCE IN GETTING VERY CLOSE TO MDW
* MEDIUM CONFIDENCE IN TSRA IMPACTING THE TERMINALS LATE
TONIGHT...BUT LOW CONFIDENCE ON TIMING
* MEDIUM CONFIDENCE ON MVFR CIGS FOLLOWING TSRA...BUT LOW
CONFIDENCE ON TIMING
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...TSRA WITH MVFR/IFR POSSIBLE.
SUNDAY THROUGH TUESDAY...PERIODIC CHANCES FOR TSRA/SHRA. PRIMARILY VFR.
WEDNESDAY THROUGH THURSDAY...SMALL CHANCES FOR SHRA. PRIMARILY VFR.
KMD
&&
.MARINE...
332 AM CDT
HIGH PRESSURE HAS SHIFTED TO THE EASTERN GREAT LAKES EARLY THIS
MORNING...AND WINDS HAVE TURNED MORE SOUTHERLY ACROSS THE LAKE.
EXPECT SPEEDS TO INCREASE TODAY IN RESPONSE TO A STRONGER GRADIENT
CREATED BY LOW PRESSURE CENTERED IN NORTHERN MANITOBA AND INTO THE
NORTHERN PLAINS. THE STRONGER GRADIENT WILL BE OVER THE NORTHERN
HALF OF THE LAKE...WHERE SOUTH WINDS INCREASE TO 15 TO 25 KT...WHILE
THE SOUTH HALF WILL SEE S TO SE WINDS AT 10-20 KT. WINDS DIMINISH
SATURDAY AS A TROUGH OF LOW PRESSURE MOVES OVERHEAD AND BECOME
SOUTHWEST SATURDAY NIGHT.
A LOW PASSES WELL NORTH OF THE LAKE SATURDAY NIGHT AND SUNDAY AND
ITS COLD FRONT SWINGS OVER THE LAKE SUNDAY MORNING. WINDS BECOME
WEST BEHIND THE FRONT MAINLY FOR THE NORTHERN HALF...AND THEN A
SECOND FRONT PUSHES DOWN THE LAKE SUNDAY NIGHT INTO MONDAY BEFORE
FINALLY CLEARING THE LAKE MONDAY EVENING. WINDS WILL BECOME NORTH
TO NORTHWEST 10-20 KT BEHIND THE FRONT. WINDS DIMINISH LATE TUESDAY
NIGHT AND THEN HIGH PRESSURE MOVES OVER THE LAKE WEDNESDAY NIGHT.
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/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS TOPEKA KS
641 PM CDT Sat Jul 12 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 336 PM CDT SAT JUL 12 2014
19Z water vapor imagery shows a broad mid level ridge centered over
northern OK/southern KS while a deep closed low spun over Manitoba
and was beginning to move south. One trough axis appears to have
rotated through NEB with a second shortwave trough digging southeast
through ND. At the surface a cold front stretched from northwest KS
into central IA, and has been slowly moving southeast this afternoon.
For tonight and Sunday, the models continue to show the cold front
moving through the forecast area late tonight. This seems to make
since with the initial mid level trough rotating through IA tonight
and the ridge overhead breaking down. Most of the model guidance
shows a well defined band of frontogenesis within the mid levels of
the atmosphere along with a narrow axis of moisture. This appears to
be the main driver of precip tonight and Sunday as forecast
soundings continue to show limited moisture in the lower atmosphere.
So think there is a good chance for elevated showers and storms to
develop this evening and overnight rather than deep moist convection
from surface parcels. Not sure if the HRRR is handling the
frontogenesis as well as it depicts convection and is the reason it
has been one of the drier solutions. Would not be surprised to see
precip lingering through the morning much like it has over
northeastern NEB and northern IA today. Since I`m expecting precip
to be elevated, chances for severe weather appear to be very limited
due to modest elevated instability from 700-500MB lapse rates only
around 6 C/km.
There does not appear to be a big surge in cold dry air behind the
front tonight. Obs upstream show decent moisture pooling behind the
boundary. With mostly cloudy skies anticipated behind the front and
dewpoints remaining in the mid and upper 60s behind the front, think
lows will once again be mild. Areas along the NEB state line should
see lows in the upper 60s while elsewhere is expected to remain in
the lower 70s. Think highs Sunday will depend on how much insolation
reaches the ground. With skies likely to remain partly to mostly
cloudy across east central KS from the elevated showers, have highs
in the mid 80s across Anderson and Coffey counties. Elsewhere think there
could be enough sunshine for highs to reach the upper 80s to around
90. Considered maybe bumping highs up a degree or two from what I
have now since there isn`t a lot of cold air advection behind the
front, but held off since models show some cooling at 850 and the
thermal ridge setting up further south.
.LONG TERM...(Sunday Night through Saturday)
Issued at 336 PM CDT SAT JUL 12 2014
Will linger a low pop across the far southeast counties of the cwa for
Sunday evening...otherwise will leave the remainder of the forecast dry
overnight except for the far northwest corner with the approach of the
next shortwave trough. As this wave and stronger cold front moves
through...mid level frontogenesis will increase from north to south
through midday with decreasing lift in the mid to late afternoon
across the southern cwa. Will therefore go dry all areas of the
county warning area. Rainfall amounts will generally average a tenth
to a third of an inch during the day.
Much cooler and drier air works southward across the cwa through the
night with 850 temps by sunrise Tuesday falling into the 7 to 10 deg
C range with diminishing winds and mostly clear skies. This will
probably be the coolest morning of the week with lows in the low to
middle 50s all areas which will be near or just above record lows
for July 15th.
By late Tuesday night models try to bring the remnants of an MCS
east and southeast across central Ks which may clip the far
southwest corner of the cwa by sunrise...then the southern half of
the cwa during the day. Have inserted low pops across this
area...and inched low temps up due to more cloudcover...but still
unseasonably cool in the middle to upper 50s and highs in the 70s.
As another northwest flow shortwave moves from the central high
plains into the southern plains...most of the precip through the end
of the week should remain south of the cwa with weak upper ridging
building back into the area by the weekend. Will keep the remainder
of the fcst beyond Wednesday dry with a gradual warming trend. Highs
will warm through the 80s as low temps moderate through the 60s to
around 70 by Saturday night.
&&
.AVIATION...(For the 00Z TAFs through 00Z Sunday Evening)
Issued at 631 PM CDT SAT JUL 12 2014
VFR prevails through forecast as a cold front tracks southeast,
veering south winds to the north aft 07Z at KMHK and 08Z at
KTOP/KFOE. Low level moisture through 9 kft is fairly shallow with
VFR cloud bases expected as light SHRA with possible embedded
thunder impacts sites between 07Z and 13Z. Dependent on coverage
and intensity of showers, there is some indication from guidance
of a SCT MVFR deck forming as showers exit Sunday morning.
Lowered cigs to 3 kft for this issuance and will continue to see
how convection and short term guidance trends.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
606 PM CDT Sat Jul 12 2014
...Updated aviation discussion...
.SHORT TERM...(This evening through Sunday)
ISSUED AT 100 PM CDT SAT JUL 12 2014
Short range models indicate the upper level shortwave in the
Northern Plains pushing eastward into the Great Lakes Region
tonight. As the shortwave moves across the region, an attendant
frontal boundary will shift slowly southward out of Nebraska into
northwest and north central Kansas this evening. Ample low level
moisture will be present with surface dewpoints well into the lower
to mid 60s(F) across central and southwest Kansas. Even with a weak
flow aloft in place across the high plains of western Kansas, enough
instability and forcing will exist to support thunderstorm
development in the vicinity of the boundary across west central,
central, and portions of southwest Kansas tonight. Although the
flow aloft will remain fairly weak as mentioned above, CAPE values
in excess of 1000 J/Kg and steep lapse rates suggest the
possibility for stronger storms with gusty winds the primary
threat. Widespread severe weather is not expected.
Little change is expected to the air mass in place across the high
plains of western Kansas tonight. As a result, look for lows back
down into the 60s(F) across west central Kansas to the lower 70s(F)
in south central Kansas. Slightly cooler temperatures are likely
Sunday as a weak frontal boundary pushes southward into Oklahoma.
Expect highs only up into the 80s(F) across central Kansas with
lower to mid 90s(F) still possible closer to the Oklahoma border.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 240 PM CDT SAT JUL 12 2014
By Sunday evening, the strong cold front will be down in Northern
Oklahoma, but still pretty close to the Kansas southern border.
Thunderstorms will be possible, mainly down along the Kansas and
Oklahoma border, with 30 to 40 percent chances. The flow aloft will
be northwest, with a high pressure center over Nevada and a strong
upper low pressure area over Western Ontario. Minor short waves
will travel southeast in the NW flow, and will help trigger storms
near the cold front. The surface high pressure, cold in nature,
will settle into the southern Mississippi Valley, with an east to
southeast upslope flow forming near the surface over Western
Kansas.
One after another upper short wave, some larger than others, will
flow through Western Kansas and bring rain chances to our CWA, from
Monday into Wednesday night. The rain Monday and Monday night will
mainly be from upslope precipitation, and some thunderstorm
activity is still possible. Going into Tuesday, a real cool down
will take affect, with Maximum Temperatures Tuesday falling into
the mid to upper 70s, and Wednesday only into the lower to mid 70s
for high temperatures. Thursday still looks cool with an upslope
affect, and highs should be in the upper 70s to near 80 degrees.
The precipitation will end sometime on Thursday, with a mid to
upper level downslope pattern forming. Friday`s maximum temperatures
will rise to the middle to upper 80s, on their way to lower 90s by
Saturday.
By Saturday, there will be a lee side trough enter far western
Kansas, and by afternoon there could be some thunderstorms, with 20
to 30 percent chances in our west and southwest zones.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 602 PM CDT SAT JUL 12 2014
Moisture will increase in the 800mb to 600mb level tonight as an
upper level disturbance moves across the western Kansas. VFR
conditions can be expected given that the main moisture will be
at or above the 800mb level. In addition to the increasing clouds
there will also be a chance for some scattered thunderstorms.
Based on the latest RAP and HRRR along with most recent radar
trend will favor thunderstorms between 00z and 04z at Hays and
Garden City, and in the Dodge area between 04z and 09z. Given the
scattered nature of these storms tonight will go with VCTS at all
taf sites. A cold front will cross western Kansas overnight which
will shift a south/southwest wind to the north/northeast. Will
base timing of the frontal passage with the NAM, RAP and HRRR.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 70 89 68 88 / 30 30 30 30
GCK 68 88 67 87 / 40 20 30 30
EHA 68 91 67 87 / 30 40 40 50
LBL 69 92 68 88 / 30 30 30 40
HYS 68 88 68 88 / 40 20 30 40
P28 72 94 71 90 / 20 30 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JJohnson
LONG TERM...Burke
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS JACKSON KY
928 PM EDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 928 PM EDT SAT JUL 12 2014
WITH WINDS DECOUPLING IN THE VALLEYS...TEMPS HAVE DROPPED AND DEW
POINTS HAVE JUMPED. HAVE UPDATED GRIDS TO ACCOUNT FOR THE LATEST OBS.
THE FORECAST FOR OVERNIGHT REMAINS UNCHANGED.
UPDATE ISSUED AT 614 PM EDT SAT JUL 12 2014
A SIGNIFICANT AMOUNT OF CIRRUS HAS MOVED INTO THE REGION...BUT IT
WAS GRADUALLY DISSIPATING. INCREASED SKY COVER FOR EARLY THIS
EVENING...BUT STAYED WITH A TREND TOWARD THE LOWER VALUES OF THE
PREVIOUS FORECAST FOR LATE TONIGHT. DRY SURFACE AIR AND WARM AIR
ADVECTION TONIGHT WOULD FAVOR SOME RIDGE/VALLEY TEMPERATURE
DIFFERENCES...AND HAVE LOWERED VALLEY MINS JUST A BIT FOR TONIGHT.
WITHOUT OVERCAST SKIES OR SIGNIFICANT WIND...CLIMATOLOGY STRONGLY
FAVORS AT LEAST SOME FOG IN THE DEEPER VALLEYS AT THIS TIME OF YEAR.
SO...DESPITE THE DRY AIR...HAVE ADDED SOME PATCHY FOG IN VALLEYS FOR
LATE TONIGHT...BUT PREVIOUS THINKING OF LESS SUBSTANTIAL FOG THAN IN
RECENT NIGHTS SHOULD STILL PLAY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 315 PM EDT SAT JUL 12 2014
ISOLATED CONVECTION MAINLY TIED TO TERRAIN IS EXPECTED TO REMAIN TO
OUR SOUTH AND SOUTHEAST OVER SW VA AND THE HIGHER TERRAIN OF TN AND
NC FOR THE REMAINDER OF THIS AFTERNOON. THE AREA OF SHOWERS AND
THUNDERSTORMS OVER WESTERN INDIANA AND WESTERN KY IS AHEAD OF A NEARLY
STATIONARY WARM FRONTAL BOUNDARY THAT REPRESENTS THE LEADING EDGE OF
70 PLUS DEW POINT TEMPERATURES OVER IL AND MO. SATELLITE...RADAR AND
LIGHTNING TRENDS ALL SHOW CONTINUING WEAKENING OF CONVECTION OVER
INDIANA...BUT THERE HAS BEEN SOME DEVELOPMENT INTO WESTERN KY. THE
SHORT RANGE RAP AND HRRR CONTINUE TO SHOW OVERALL DECAY OF CONVECTION
TO OUR WEST...AND ONLY IMPACT IN OUR AREA WILL BE SOME INCREASE IN
HIGH LEVEL CLOUDS.
WITH VERY DRY LOW LEVEL AIR IN PLACE IN EASTERN KY THIS
AFTERNOON...NOTE DEW POINT AS LOW AS 48 AT QUICKSAND MESONET...THERE
WILL BE EVEN LESS FOG TONIGHT AS THERE WAS LAST NIGHT. GUIDANCE NOT
HANDLING THE DRY AIR VERY WELL...AND EXPECT THERE TO BE ABOUT A 5
DEGREE RIDGE VALLEY TEMPERATURE SPLIT FOR TONIGHT.
ON SUNDAY INSTABILITY WILL INCREASE AHEAD OF AN APPROACHING COLD
FRONT WITH MUCAPE IN EXCESS OF 4000 J/KG DEVELOPING IN A CORRIDOR
NORTH OF THE OH RIVER ACROSS SOUTHERN IN AND OH. BEST SHEAR WILL ALSO
BE NORTH OF THE OH RIVER SUNDAY AFTERNOON AND CURRENT THINKING IS
THAT THUNDERSTORMS WILL DEVELOP ACROSS OH AND INDIANA AND THEN
PROGRESS INTO NORTHERN PARTS OF THE FORECAST AREA LATE SUNDAY
AFTERNOON OR SUNDAY NIGHT. AT THE SAME TIME SOME ISOLATED TO
SCATTERED CONVECTION MAY DEVELOP OVER THE SOUTHEAST MOUNTAINS SUNDAY
AFTERNOON. THIS WOULD ALSO BE IN A CORRIDOR OF SLIGHTLY GREATER
INSTABILITY AND ALSO PARTIALLY TIED TO THE HIGHER TERRAIN. THE MODELS
HAVE BEEN CONSISTENT AT HINTING AT THIS POSSIBILITY IN THE SE
FORECAST AREA. CONSIDERING ALL THIS WILL BRING CHANCE PROBABILITY OF
SHOWERS AND THUNDERSTORMS TO THE SOUTHEAST AND NORTHERN PARTS OF THE
FORECAST AREA FIRST ON SUNDAY...WITH THE CENTRAL AND SOUTHWEST PARTS
OF THE FORECAST AREA THE LAST TO SEE THE RAIN CHANCES.
THE CONVECTION THAT DEVELOPS TO OUR NORTH ON SUNDAY HAS SEVERE
POTENTIAL...BUT AS IT MOVES INTO OUR AREA SUNDAY NIGHT AWAY FROM
BEST SUPPORT...THE SEVERE THREAT WILL DECREASE. THE DAY 2 SEVERE
WEATHER OUTLOOK WITH ONLY OUR FAR NW COUNTIES HAVING A SLIGHT RISK OF
SEVERE WEATHER THROUGH 12Z MONDAY CONTINUES TO LOOK GOOD. WITH PW
INCREASING THROUGH SUNDAY NIGHT TO 1.7 TO POSSIBLY GREATER THAN 2
INCHES SOME HEAVY RAINERS ARE DEFINITELY A POSSIBILITY SUNDAY NIGHT. MUCH
OF THE AREA HAS BEEN PLACED IN THE DAY 2 EXCESSIVE RAINFALL OUTLOOK
VALID 00Z MONDAY TO 00Z TUESDAY. FLASH FLOOD GUIDANCE IS FAIRLY HIGH
HOWEVER...AND PART OF THE AREA IS CURRENTLY IN D1 DROUGHT. INITIALLY...
AT LEAST FOR SUNDAY NIGHT...WHICH IS THE FIRST HALF OF THIS OUTLOOK
PERIOD THE FLASH FLOOD THREAT LOOKS BE ISOLATED AT WORST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 315 PM EDT SAT JUL 12 2014
THE GFS IS SHOWING SOME DECENT CONTINUITY THROUGH THE LAST FEW
CYCLES BUT STILL APPEARS OUTSIDE THE RANGE OF OTHER SOLUTIONS AND
TOO PROGRESSIVE...ESPECIALLY CONSIDERING THE EXPECTED AMPLITUDE OF
THE MID AND UPPER LEVEL PATTERNS. THE ECMWF...WHICH HAS BEEN MORE
CONSISTENT IS ADVERTISING A SLOWER SYSTEM THAT PUNCHES FURTHER SOUTH
THAN OTHER MODELS AND IS ON THE SLOWER SIDE OF THE ENVELOPE OF
SOLUTIONS THROUGH THE MID TERM. JUST THE SAME MODELS ROUGHLY AGREE
ON THE OVERALL SCENARIO OF THE LARGE SCALE PATTERN. THE MAIN...AND
MOST SIGNIFICANT DIFFERENCES CROP UP RESOLVING SURFACE FEATURES AND
THE TIMING OF SFC SYSTEMS THROUGH OUR AREA. ATTM TENDENCY IS TO LEAN
TOWARDS THE ECMWF SOLUTION THROUGH THE MID RANGE AFTER USING A
CONSENSUS SOLUTION TO INITIALIZE THE EXTENDED PORTION OF THE
FORECAST PACKAGE. WILL STICK TO A BLENDED APPROACH FOR THE END OF
THE FORECAST WINDOW AS ADDITIONAL ENERGY EMERGES FROM THE PACIFIC
NW/CANADA CAUSING THE PATTERN TO BECOME LESS AMPLIFIED...BUT ALSO
ALLOWING FOR THE MEAN STORM TRACK TO RETURN NORTHWARD CLOSER TO OUR
NECK OF THE WOODS.
HEIGHTS FALL DROP STEADILY THROUGH THE FIRST HALF OF THE PERIOD AS A
SPLITTING UPPER LEVEL LOW DROPS A SIGNIFICANT PORTION OF ITS ENERGY
INTO THE THE UPPER MIDWEST AND GREAT LAKES...RESULTING IN A LARGE
DEEP TROUGH ACROSS THE ENTIRE EASTERN CONUS BY MID WEEK. SURFACE
FRONTAL ZONE WILL DROP SOUTHWARD ALONG THE OHIO RIVER BY LATE SUNDAY
OR SUNDAY NIGHT. A SECOND STRONGER...FASTER FRONTAL BOUNDARY WILL
FOLLOW QUICKLY BEHIND THE FIRST SLIDING THROUGH OUR AREA AS SOON AS
MONDAY NIGHT...OR AS LATE AS TUESDAY AFTERNOON DEPENDING ON WHICH
MODEL YOU LOOK AT. IT STILL SEEMS LIKE THE GFS IS HAVING TROUBLE
RESOLVING THE TIMING OR PASSAGE OF THESE TWO FRONTAL BOUNDARIES...
WITH A TENDENCY TO MERGE EACH DISTINCT BOUNDARY INTO A SINGLE FINAL
SYSTEM THAT MOVES THROUGH EASTERN KENTUCKY TOO QUICKLY.
WE ARE STILL LOOKING AT THE POTENTIAL FOR SOME SEVERE WEATHER THOUGH
THE TIME OF DAY AND EXACT AMOUNT OF SUNLIGHT WILL BE SOMETHING THAT
WILL NEED TO BE FACTORED IN. AS IS TYPICAL...THE NAM IS CONSIDERABLY
MORE UNSTABLE IN THE BOUNDARY LAYER BECAUSE OF ITS WET BIAS. THE NAM
IS ALSO SHOWING HIGHER BULK SHEAR VALUES THROUGH THE EARLY MONDAY
MORNING TO MONDAY AFTERNOON TIME FRAME. PWATS AND LIFT THROUGH THE
COLUMN ARE MUCH MORE IMPRESSIVE AS WELL WHEN COMPARED TO THE GFS.
EXPECT THE TRUTH WILL LIE SOMEWHERE IN THE MIDDLE THOUGH THAT MAY BE
A BAD ASSUMPTION GIVEN THE GFS MIGHT BE HAVING TROUBLE
DISTINGUISHING SURFACE AND BOUNDARY LAYER DETAILS. FREEZING LEVELS
REMAIN HIGH. SO WHILE SOME HEAVY RAIN CAN NOT BE RULED OUT...STORM
MOTION IS HIGH ENOUGH THAT HYDRO PROBLEMS SHOULD NOT BECOME TOO MUCH
OF A PROBLEM...AT LEAST BASED ON CURRENT GUIDANCE. BIGGEST THREAT
FOR SEVERE WEATHER WILL GENERALLY LIE ACROSS OUR BLUE GRASS COUNTIES
SUNDAY...BUT THEN EXPAND SOUTHEASTWARD TO ENCOMPASS OUR ENTIRE
FORECAST AREA BY MONDAY.
WE ARE STILL LOOKING AT UNSEASONABLE COLD WEATHER FOR THE PEAK OF
SUMMER HEATING THROUGH THE MIDDLE OF UPCOMING WEEK. ECMWF H850 TEMPS
DROP TO AROUND 8C AND THE GFS HAS TRENDED TOWARDS THE ECMWF. ECMWF
MOS GUIDANCE IS QUITE COOL WITH AFTERNOON HIGHS IN THE LOWER TO MID
70S AND LOWS SOLIDLY IN THE 50S FROM TUESDAY THROUGH FRIDAY. WHILE
THERE IS SOME MODERATION TOWARDS THE END OF THE WEEK...THERE IS A
GOOD POTENTIAL FOR SOME RECORD COLD MORNING LOWS AND EVEN A FEW
RECORD LOW MAXES. GFS MOS IS CONSIDERABLY WARMER BUT HAS SHOWN SIGNS
OF COOLING. PAST EXPERIENCE HAS TAUGHT THAT A BLEND OF GUIDANCE
MAKES A BEST FIRST GUESS...AFTER A TWEAK TOWARDS THE TYPICALLY MORE
ACCURATE ECMWF MOS.
ADDITIONAL ENERGY MOVING OUT OF THE NORTHWEST AND INTO THE BASE OF
THE BY THEN LIFTING EASTERN CONUS TROUGH WILL BRING A THREAT OF RAIN
BACK INTO THE FORECAST AREA AT THE END OF THE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 723 PM EDT SAT JUL 12 2014
PREDOMINANTLY VFR WITH LIGHT WINDS IS EXPECTED DURING THE PERIOD. AN
EXCEPTION WILL BE LOCALIZED FOG IN DEEP VALLEYS LATE TONIGHT AND
EARLY SUNDAY. THERE COULD ALSO BE A FEW SHOWERS AND THUNDERSTORMS
POPPING UP DURING THE DAY ON SUNDAY...WITH LOCALIZED RESTRICTIONS TO
CIGS/VSBY. THE PROBABILITY OF ANY GIVEN TAF SITE GETTING HIT IS TOO
LOW TO WARRANT MENTIONING IT IN A TAF AT THIS POINT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...SBH
LONG TERM...RAY
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
723 PM EDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 614 PM EDT SAT JUL 12 2014
A SIGNIFICANT AMOUNT OF CIRRUS HAS MOVED INTO THE REGION...BUT IT
WAS GRADUALLY DISSIPATING. INCREASED SKY COVER FOR EARLY THIS
EVENING...BUT STAYED WITH A TREND TOWARD THE LOWER VALUES OF THE
PREVIOUS FORECAST FOR LATE TONIGHT. DRY SURFACE AIR AND WARM AIR
ADVECTION TONIGHT WOULD FAVOR SOME RIDGE/VALLEY TEMPERATURE
DIFFERENCES...AND HAVE LOWERED VALLEY MINS JUST A BIT FOR TONIGHT.
WITHOUT OVERCAST SKIES OR SIGNIFICANT WIND...CLIMATOLOGY STRONGLY
FAVORS AT LEAST SOME FOG IN THE DEEPER VALLEYS AT THIS TIME OF YEAR.
SO...DESPITE THE DRY AIR...HAVE ADDED SOME PATCHY FOG IN VALLEYS FOR
LATE TONIGHT...BUT PREVIOUS THINKING OF LESS SUBSTANTIAL FOG THAN IN
RECENT NIGHTS SHOULD STILL PLAY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 315 PM EDT SAT JUL 12 2014
ISOLATED CONVECTION MAINLY TIED TO TERRAIN IS EXPECTED TO REMAIN TO
OUR SOUTH AND SOUTHEAST OVER SW VA AND THE HIGHER TERRAIN OF TN AND
NC FOR THE REMAINDER OF THIS AFTERNOON. THE AREA OF SHOWERS AND
THUNDERSTORMS OVER WESTERN INDIANA AND WESTERN KY IS AHEAD OF A NEARLY
STATIONARY WARM FRONTAL BOUNDARY THAT REPRESENTS THE LEADING EDGE OF
70 PLUS DEW POINT TEMPERATURES OVER IL AND MO. SATELLITE...RADAR AND
LIGHTNING TRENDS ALL SHOW CONTINUING WEAKENING OF CONVECTION OVER
INDIANA...BUT THERE HAS BEEN SOME DEVELOPMENT INTO WESTERN KY. THE
SHORT RANGE RAP AND HRRR CONTINUE TO SHOW OVERALL DECAY OF CONVECTION
TO OUR WEST...AND ONLY IMPACT IN OUR AREA WILL BE SOME INCREASE IN
HIGH LEVEL CLOUDS.
WITH VERY DRY LOW LEVEL AIR IN PLACE IN EASTERN KY THIS
AFTERNOON...NOTE DEW POINT AS LOW AS 48 AT QUICKSAND MESONET...THERE
WILL BE EVEN LESS FOG TONIGHT AS THERE WAS LAST NIGHT. GUIDANCE NOT
HANDLING THE DRY AIR VERY WELL...AND EXPECT THERE TO BE ABOUT A 5
DEGREE RIDGE VALLEY TEMPERATURE SPLIT FOR TONIGHT.
ON SUNDAY INSTABILITY WILL INCREASE AHEAD OF AN APPROACHING COLD
FRONT WITH MUCAPE IN EXCESS OF 4000 J/KG DEVELOPING IN A CORRIDOR
NORTH OF THE OH RIVER ACROSS SOUTHERN IN AND OH. BEST SHEAR WILL ALSO
BE NORTH OF THE OH RIVER SUNDAY AFTERNOON AND CURRENT THINKING IS
THAT THUNDERSTORMS WILL DEVELOP ACROSS OH AND INDIANA AND THEN
PROGRESS INTO NORTHERN PARTS OF THE FORECAST AREA LATE SUNDAY
AFTERNOON OR SUNDAY NIGHT. AT THE SAME TIME SOME ISOLATED TO
SCATTERED CONVECTION MAY DEVELOP OVER THE SOUTHEAST MOUNTAINS SUNDAY
AFTERNOON. THIS WOULD ALSO BE IN A CORRIDOR OF SLIGHTLY GREATER
INSTABILITY AND ALSO PARTIALLY TIED TO THE HIGHER TERRAIN. THE MODELS
HAVE BEEN CONSISTENT AT HINTING AT THIS POSSIBILITY IN THE SE
FORECAST AREA. CONSIDERING ALL THIS WILL BRING CHANCE PROBABILITY OF
SHOWERS AND THUNDERSTORMS TO THE SOUTHEAST AND NORTHERN PARTS OF THE
FORECAST AREA FIRST ON SUNDAY...WITH THE CENTRAL AND SOUTHWEST PARTS
OF THE FORECAST AREA THE LAST TO SEE THE RAIN CHANCES.
THE CONVECTION THAT DEVELOPS TO OUR NORTH ON SUNDAY HAS SEVERE
POTENTIAL...BUT AS IT MOVES INTO OUR AREA SUNDAY NIGHT AWAY FROM
BEST SUPPORT...THE SEVERE THREAT WILL DECREASE. THE DAY 2 SEVERE
WEATHER OUTLOOK WITH ONLY OUR FAR NW COUNTIES HAVING A SLIGHT RISK OF
SEVERE WEATHER THROUGH 12Z MONDAY CONTINUES TO LOOK GOOD. WITH PW
INCREASING THROUGH SUNDAY NIGHT TO 1.7 TO POSSIBLY GREATER THAN 2
INCHES SOME HEAVY RAINERS ARE DEFINITELY A POSSIBILITY SUNDAY NIGHT. MUCH
OF THE AREA HAS BEEN PLACED IN THE DAY 2 EXCESSIVE RAINFALL OUTLOOK
VALID 00Z MONDAY TO 00Z TUESDAY. FLASH FLOOD GUIDANCE IS FAIRLY HIGH
HOWEVER...AND PART OF THE AREA IS CURRENTLY IN D1 DROUGHT. INITIALLY...
AT LEAST FOR SUNDAY NIGHT...WHICH IS THE FIRST HALF OF THIS OUTLOOK
PERIOD THE FLASH FLOOD THREAT LOOKS BE ISOLATED AT WORST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 315 PM EDT SAT JUL 12 2014
THE GFS IS SHOWING SOME DECENT CONTINUITY THROUGH THE LAST FEW
CYCLES BUT STILL APPEARS OUTSIDE THE RANGE OF OTHER SOLUTIONS AND
TOO PROGRESSIVE...ESPECIALLY CONSIDERING THE EXPECTED AMPLITUDE OF
THE MID AND UPPER LEVEL PATTERNS. THE ECMWF...WHICH HAS BEEN MORE
CONSISTENT IS ADVERTISING A SLOWER SYSTEM THAT PUNCHES FURTHER SOUTH
THAN OTHER MODELS AND IS ON THE SLOWER SIDE OF THE ENVELOPE OF
SOLUTIONS THROUGH THE MID TERM. JUST THE SAME MODELS ROUGHLY AGREE
ON THE OVERALL SCENARIO OF THE LARGE SCALE PATTERN. THE MAIN...AND
MOST SIGNIFICANT DIFFERENCES CROP UP RESOLVING SURFACE FEATURES AND
THE TIMING OF SFC SYSTEMS THROUGH OUR AREA. ATTM TENDENCY IS TO LEAN
TOWARDS THE ECMWF SOLUTION THROUGH THE MID RANGE AFTER USING A
CONSENSUS SOLUTION TO INITIALIZE THE EXTENDED PORTION OF THE
FORECAST PACKAGE. WILL STICK TO A BLENDED APPROACH FOR THE END OF
THE FORECAST WINDOW AS ADDITIONAL ENERGY EMERGES FROM THE PACIFIC
NW/CANADA CAUSING THE PATTERN TO BECOME LESS AMPLIFIED...BUT ALSO
ALLOWING FOR THE MEAN STORM TRACK TO RETURN NORTHWARD CLOSER TO OUR
NECK OF THE WOODS.
HEIGHTS FALL DROP STEADILY THROUGH THE FIRST HALF OF THE PERIOD AS A
SPLITTING UPPER LEVEL LOW DROPS A SIGNIFICANT PORTION OF ITS ENERGY
INTO THE THE UPPER MIDWEST AND GREAT LAKES...RESULTING IN A LARGE
DEEP TROUGH ACROSS THE ENTIRE EASTERN CONUS BY MID WEEK. SURFACE
FRONTAL ZONE WILL DROP SOUTHWARD ALONG THE OHIO RIVER BY LATE SUNDAY
OR SUNDAY NIGHT. A SECOND STRONGER...FASTER FRONTAL BOUNDARY WILL
FOLLOW QUICKLY BEHIND THE FIRST SLIDING THROUGH OUR AREA AS SOON AS
MONDAY NIGHT...OR AS LATE AS TUESDAY AFTERNOON DEPENDING ON WHICH
MODEL YOU LOOK AT. IT STILL SEEMS LIKE THE GFS IS HAVING TROUBLE
RESOLVING THE TIMING OR PASSAGE OF THESE TWO FRONTAL BOUNDARIES...
WITH A TENDENCY TO MERGE EACH DISTINCT BOUNDARY INTO A SINGLE FINAL
SYSTEM THAT MOVES THROUGH EASTERN KENTUCKY TOO QUICKLY.
WE ARE STILL LOOKING AT THE POTENTIAL FOR SOME SEVERE WEATHER THOUGH
THE TIME OF DAY AND EXACT AMOUNT OF SUNLIGHT WILL BE SOMETHING THAT
WILL NEED TO BE FACTORED IN. AS IS TYPICAL...THE NAM IS CONSIDERABLY
MORE UNSTABLE IN THE BOUNDARY LAYER BECAUSE OF ITS WET BIAS. THE NAM
IS ALSO SHOWING HIGHER BULK SHEAR VALUES THROUGH THE EARLY MONDAY
MORNING TO MONDAY AFTERNOON TIME FRAME. PWATS AND LIFT THROUGH THE
COLUMN ARE MUCH MORE IMPRESSIVE AS WELL WHEN COMPARED TO THE GFS.
EXPECT THE TRUTH WILL LIE SOMEWHERE IN THE MIDDLE THOUGH THAT MAY BE
A BAD ASSUMPTION GIVEN THE GFS MIGHT BE HAVING TROUBLE
DISTINGUISHING SURFACE AND BOUNDARY LAYER DETAILS. FREEZING LEVELS
REMAIN HIGH. SO WHILE SOME HEAVY RAIN CAN NOT BE RULED OUT...STORM
MOTION IS HIGH ENOUGH THAT HYDRO PROBLEMS SHOULD NOT BECOME TOO MUCH
OF A PROBLEM...AT LEAST BASED ON CURRENT GUIDANCE. BIGGEST THREAT
FOR SEVERE WEATHER WILL GENERALLY LIE ACROSS OUR BLUE GRASS COUNTIES
SUNDAY...BUT THEN EXPAND SOUTHEASTWARD TO ENCOMPASS OUR ENTIRE
FORECAST AREA BY MONDAY.
WE ARE STILL LOOKING AT UNSEASONABLE COLD WEATHER FOR THE PEAK OF
SUMMER HEATING THROUGH THE MIDDLE OF UPCOMING WEEK. ECMWF H850 TEMPS
DROP TO AROUND 8C AND THE GFS HAS TRENDED TOWARDS THE ECMWF. ECMWF
MOS GUIDANCE IS QUITE COOL WITH AFTERNOON HIGHS IN THE LOWER TO MID
70S AND LOWS SOLIDLY IN THE 50S FROM TUESDAY THROUGH FRIDAY. WHILE
THERE IS SOME MODERATION TOWARDS THE END OF THE WEEK...THERE IS A
GOOD POTENTIAL FOR SOME RECORD COLD MORNING LOWS AND EVEN A FEW
RECORD LOW MAXES. GFS MOS IS CONSIDERABLY WARMER BUT HAS SHOWN SIGNS
OF COOLING. PAST EXPERIENCE HAS TAUGHT THAT A BLEND OF GUIDANCE
MAKES A BEST FIRST GUESS...AFTER A TWEAK TOWARDS THE TYPICALLY MORE
ACCURATE ECMWF MOS.
ADDITIONAL ENERGY MOVING OUT OF THE NORTHWEST AND INTO THE BASE OF
THE BY THEN LIFTING EASTERN CONUS TROUGH WILL BRING A THREAT OF RAIN
BACK INTO THE FORECAST AREA AT THE END OF THE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 723 PM EDT SAT JUL 12 2014
PREDOMINANTLY VFR WITH LIGHT WINDS IS EXPECTED DURING THE PERIOD. AN
EXCEPTION WILL BE LOCALIZED FOG IN DEEP VALLEYS LATE TONIGHT AND
EARLY SUNDAY. THERE COULD ALSO BE A FEW SHOWERS AND THUNDERSTORMS
POPPING UP DURING THE DAY ON SUNDAY...WITH LOCALIZED RESTRICTIONS TO
CIGS/VSBY. THE PROBABILITY OF ANY GIVEN TAF SITE GETTING HIT IS TOO
LOW TO WARRANT MENTIONING IT IN A TAF AT THIS POINT.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...HAL
SHORT TERM...SBH
LONG TERM...RAY
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1237 PM CDT FRI JUL 11 2014
.DISCUSSION...
11/18Z TAF ISSUANCE.
&&
.AVIATION...
FEW CU BEGINNING TO DEVELOP ACRS THE AREA...WITH DEEPEST CLOUDS
CONCENTRATED ALONG THE SEABREEZE NR THE COAST. SFC HIGH PRES
CNTRD OHD IS PRODUCING NR CALM OR LT VRBL WINDS...AND PER LATEST
VISBL SATELLITE TRENDS...THE SEABREEZE TRANSITIONS TO LAND BREEZE
S OF VERMILION BAY DUE A BETTER OFFSHORE WIND COMPONENT. A FEW
SMALL ISOLTD SH OR TS HAVE DEVELOPED ALONG THE BOUNDARY...WITH
LITTLE ELSEWHERE AS WEAK MID LVL RIDGING HELPS LIMIT CONVECTION.
REMOVED TEMPO GROUPS FM SRN SITES BUT KEPT VCTS AS SOME INLAND
PROGRESSION OF SEABREEZE STILL ANTICIPATED DURING THE AFTN.
OTHERWISE...VFR EXPECTED TO PREVAIL THROUGH THE PERIOD. 24
&&
.PREV DISCUSSION... /ISSUED 1039 AM CDT FRI JUL 11 2014/
UPDATE...
VISIBLE SATELLITE IMAGERY SHOWING CLOUDS BOILING UP ALONG THE
COASTLINE PRETTY MUCH OUTLINING THE SEA BREEZE RIGHT ALONG THE
COAST. CLOUD BUILDUP INITIALLY LOOKED BETTER NEAR SABINE LAKE
AREA...THEN POOF...GONE...TO STABLE THERE STILL. THERE IS ALSO
BUILDUP FROM EAST OF GRAND CHENIER EXTENDING EAST TO PECAN
ISLAND. RADAR ALSO SHOWING THE INITIAL BUDDINGS OF SHOWERS
DEVELOPING EAST OF PECAN ISLAND. ONE THING TO NOTE TODAY...THE UPPER
LEVEL STEERING CURRENTS LOOK VERY WEAK. THEREFORE...EXPECT
CONVECTION TO HOLD PRETTY TIGHT TO THE SEA BREEZE. OUTFLOW
BOUNDARIES WILL NEED TO BE EXCEPTIONAL TODAY TO GET BETTER
DISTRIBUTION. MY INITIAL THOUGHTS...ZONE FORECAST PACKAGE LOOKS
PRETTY GOOD. I WILL NOT MAKE ANY CHANGES TO THE CURRENT PACKAGE. I
DO SEE THAT THIS EVENING... HIGH RESOLUTION RAPID REFRESH MODEL
(HRRR) AND WEATHER RESEARCH AND FORECAST MODEL (WRF) ARE SHOWING
SOME CARRYOVER INTO THE EVENING PACKAGE FOR SOME RAIN TO CONTINUE
IN SOME AREAS MOSTLY BETWEEN THE I-10 CORRIDOR BETWEEN LAKE
CHARLES AND LAFAYETTE. WILL MONITOR AND MAKE CHANGES LATER TO
EVENING ZONES IF THIS TREND CONTINUES IN THE HRRR AND WRF MODELS.
DID I SAY IT WAS GOING TO BE HOT AND HUMID TODAY? WELL...DRINK
PLENTY OF FLUID IF YOUR GOING TO BE OUTSIDE. YOU ARE GOING TO NEED
GOOD RE-HYDRATION IF OUT TODAY. :)
PREV DISCUSSION... /ISSUED 508 AM CDT FRI JUL 11 2014/
AVIATION...
WEAK HIGH PRESSURE ACROSS CENTRAL LOUISIANA WILL PERMIT THE RETURN
OF THE SEA BREEZE ACROSS THE FORECAST AREA. PERSISTENCE BRINGS
THE SEA BREEZE ONSHORE BY MID-MORNING...BEFORE REACHING THE LAKES
REGION AND PINEY HILLS REGION BY LATE AFTERNOON.
LIFT ATTENDING UPPER LEVEL DIVERGENCE (AN ANTICYCLONIC SHEAR ZONE
ALOFT) WILL GIVE AN ADDED BOOST TO THE FRONTAL LIFT ATTENDING THE
SEA BREEZE.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED...TAPERING OFF WITH
PASSAGE OF SEA BREEZE.
JT
PREV DISCUSSION... /ISSUED 352 AM CDT FRI JUL 11 2014/
DISCUSSION...RADAR CURRENTLY SHOWING JUST A FEW SHOWERS AND
THUNDERSTORMS OVER THE NEAR COASTAL WATERS. SATELLITE DEPICTING
CLEAR SKIES INLAND. OBS BEGINNING TO PICK UP ON SOME LIGHT FOG
DEVELOPMENT HERE AND THERE WHICH HAS BEEN THE CASE THE LAST SEVERAL
NIGHTS.
TODAY AND THE WEEKEND...WITH A WEAKNESS REMAINING ALOFT...AND LOW
LEVEL SOUTHERLIES MAINTAINING ADEQUATE MOISTURE OVER THE FORECAST AREA...
WILL CONTINUE TO SEE DAILY SHOWER AND THUNDERSTORM DEVELOPMENT.
TRIGGER FOR THIS DEVELOPMENT WILL COME FROM A WEAK SEA BREEZE AND
ACCOMPANYING CONVERGENCE SLOWLY ADVANCING NORTHWARD....AS WELL AS
CONVECTIVE OUTFLOWS. OTHERWISE EXPECT A CONTINUATION OF NEAR NORMAL
TEMPERATURES...GENERALLY SPELLING SOMEWHAT HOT AND HUMID
DAYS...AND WARM AND MUGGY NIGHTS.
REMAINDER OF FORECAST...INTENSE CYCLONE PROGGED SIMILARLY BY
MODELS TO DROP OUT OF MID-CANADA AND INTO GREAT LAKES REGION EARLY
IN THE NEW-WEEK. THIS UNLIKELY MID-JULY FEATURE WILL BE
RESPONSIBLE FOR ADVANCING A COOL FRONT INTO THE AREA
TUESDAY...POSSIBLY PUNCHING FEATURE AS FAR SOUTH AS THE NORTHERN GULF
WATERS BEFORE WASHING OUT. SCENARIO PROMPTED AN INCREASE IN POPS
FOR TUESDAY AND TUESDAY NIGHT. SOUTHERN PORTION OF COLD DOME
GLANCING THE AREA WILL BRING NO MORE THAN A SLIGHT DECREASE IN
TEMPS AND DEWPOINTS. MUCH MORE IMPRESSIVE LOWERING OF THESE
ELEMENTS WILL OCCUR FURTHER NORTH AND LIKELY WILL BE RECORD-
BREAKING. RAIN CHANCES THEN CONTINUE THROUGH THE REST OF THE
FORECAST AS STRONG SOUTHERLIES DEVELOP AND IMPULSES APPROACH
AND MOVE OVERHEAD WITHIN A RELATIVELY STRONG JULY NORTHWEST FLOW
ALOFT.
MARINE...WEAK HIGH PRESSURE WILL CONTINUE TO HOLD OVER THE GULF
WATERS MAINTAINING LIGHT WINDS AND LOWS SEAS. ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY WILL GENERALLY BE THROUGH THE NIGHT-TIME
HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 93 75 93 75 / 30 10 30 10
KBPT 92 76 92 76 / 30 20 30 10
KAEX 94 75 93 75 / 20 10 20 10
KLFT 93 76 93 76 / 30 20 30 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1039 AM CDT FRI JUL 11 2014
.UPDATE...
VISIBLE SATELLITE IMAGERY SHOWING CLOUDS BOILING UP ALONG THE
COASTLINE PRETTY MUCH OUTLINING THE SEA BREEZE RIGHT ALONG THE
COAST. CLOUD BUILDUP INITIALLY LOOKED BETTER NEAR SABINE LAKE
AREA...THEN POOF...GONE...TO STABLE THERE STILL. THERE IS ALSO
BUILDUP FROM EAST OF GRAND CHENIER EXTENDING EAST TO PECAN
ISLAND. RADAR ALSO SHOWING THE INITIAL BUDDINGS OF SHOWERS
DEVELOPING EAST OF PECAN ISLAND. ONE THING TO NOTE TODAY...THE UPPER
LEVEL STEERING CURRENTS LOOK VERY WEAK. THEREFORE...EXPECT
CONVECTION TO HOLD PRETTY TIGHT TO THE SEA BREEZE. OUTFLOW
BOUNDARIES WILL NEED TO BE EXCEPTIONAL TODAY TO GET BETTER
DISTRIBUTION. MY INITIAL THOUGHTS...ZONE FORECAST PACKAGE LOOKS
PRETTY GOOD. I WILL NOT MAKE ANY CHANGES TO THE CURRENT PACKAGE. I
DO SEE THAT THIS EVENING... HIGH RESOLUTION RAPID REFRESH MODEL
(HRRR) AND WEATHER RESEARCH AND FORECAST MODEL (WRF) ARE SHOWING
SOME CARRYOVER INTO THE EVENING PACKAGE FOR SOME RAIN TO CONTINUE
IN SOME AREAS MOSTLY BETWEEN THE I-10 CORRIDOR BETWEEN LAKE
CHARLES AND LAFAYETTE. WILL MONITOR AND MAKE CHANGES LATER TO
EVENING ZONES IF THIS TREND CONTINUES IN THE HRRR AND WRF MODELS.
DID I SAY IT WAS GOING TO BE HOT AND HUMID TODAY? WELL...DRINK
PLENTY OF FLUID IF YOUR GOING TO BE OUTSIDE. YOU ARE GOING TO NEED
GOOD RE-HYDRATION IF OUT TODAY. :)
&&
.PREV DISCUSSION... /ISSUED 508 AM CDT FRI JUL 11 2014/
AVIATION...
WEAK HIGH PRESSURE ACROSS CENTRAL LOUISIANA WILL PERMIT THE RETURN
OF THE SEA BREEZE ACROSS THE FORECAST AREA. PERSISTENCE BRINGS
THE SEA BREEZE ONSHORE BY MID-MORNING...BEFORE REACHING THE LAKES
REGION AND PINEY HILLS REGION BY LATE AFTERNOON.
LIFT ATTENDING UPPER LEVEL DIVERGENCE (AN ANTICYCLONIC SHEAR ZONE
ALOFT) WILL GIVE AN ADDED BOOST TO THE FRONTAL LIFT ATTENDING THE
SEA BREEZE.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED...TAPERING OFF WITH
PASSAGE OF SEA BREEZE.
JT
PREV DISCUSSION... /ISSUED 352 AM CDT FRI JUL 11 2014/
DISCUSSION...RADAR CURRENTLY SHOWING JUST A FEW SHOWERS AND
THUNDERSTORMS OVER THE NEAR COASTAL WATERS. SATELLITE DEPICTING
CLEAR SKIES INLAND. OBS BEGINNING TO PICK UP ON SOME LIGHT FOG
DEVELOPMENT HERE AND THERE WHICH HAS BEEN THE CASE THE LAST SEVERAL
NIGHTS.
TODAY AND THE WEEKEND...WITH A WEAKNESS REMAINING ALOFT...AND LOW
LEVEL SOUTHERLIES MAINTAINING ADEQUATE MOISTURE OVER THE FORECAST AREA...
WILL CONTINUE TO SEE DAILY SHOWER AND THUNDERSTORM DEVELOPMENT.
TRIGGER FOR THIS DEVELOPMENT WILL COME FROM A WEAK SEA BREEZE AND
ACCOMPANYING CONVERGENCE SLOWLY ADVANCING NORTHWARD....AS WELL AS
CONVECTIVE OUTFLOWS. OTHERWISE EXPECT A CONTINUATION OF NEAR NORMAL
TEMPERATURES...GENERALLY SPELLING SOMEWHAT HOT AND HUMID
DAYS...AND WARM AND MUGGY NIGHTS.
REMAINDER OF FORECAST...INTENSE CYCLONE PROGGED SIMILARLY BY
MODELS TO DROP OUT OF MID-CANADA AND INTO GREAT LAKES REGION EARLY
IN THE NEW-WEEK. THIS UNLIKELY MID-JULY FEATURE WILL BE
RESPONSIBLE FOR ADVANCING A COOL FRONT INTO THE AREA
TUESDAY...POSSIBLY PUNCHING FEATURE AS FAR SOUTH AS THE NORTHERN GULF
WATERS BEFORE WASHING OUT. SCENARIO PROMPTED AN INCREASE IN POPS
FOR TUESDAY AND TUESDAY NIGHT. SOUTHERN PORTION OF COLD DOME
GLANCING THE AREA WILL BRING NO MORE THAN A SLIGHT DECREASE IN
TEMPS AND DEWPOINTS. MUCH MORE IMPRESSIVE LOWERING OF THESE
ELEMENTS WILL OCCUR FURTHER NORTH AND LIKELY WILL BE RECORD-
BREAKING. RAIN CHANCES THEN CONTINUE THROUGH THE REST OF THE
FORECAST AS STRONG SOUTHERLIES DEVELOP AND IMPULSES APPROACH
AND MOVE OVERHEAD WITHIN A RELATIVELY STRONG JULY NORTHWEST FLOW
ALOFT.
MARINE...WEAK HIGH PRESSURE WILL CONTINUE TO HOLD OVER THE GULF
WATERS MAINTAINING LIGHT WINDS AND LOWS SEAS. ISOLATED SHOWER AND
THUNDERSTORM ACTIVITY WILL GENERALLY BE THROUGH THE NIGHT-TIME
HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 93 76 93 77 / 30 10 30 10
KBPT 92 76 92 76 / 30 20 30 10
KAEX 94 75 93 75 / 20 10 20 10
KLFT 93 76 93 76 / 30 20 30 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC/MARINE...06
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
957 PM EDT SAT JUL 12 2014
.SYNOPSIS...
HIGH PRESSURE REMAINS OFF THE COAST THROUGH THE WEEKEND. LOW PRESSURE
MOVES ACROSS THE GREAT LAKES REGION WITH THE TRAILING COLD FRONT APPROACHING
FROM THE NORTHWEST EARLY NEXT WEEK. THE FRONT IS EXPECTED TO SLOWLY
PUSH THROUGH THE LOCAL AREA LATE TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
LATEST ANALYSIS SHOWING WEAK SFC HIGH PRESSURE CENTERED OFF THE
MID ATLC COAST...WITH LOW PRESSURE DEEPENING ACRS THE MID/UPPER
MS VALLEY. FLOW ALOFT IS WNW. NEARLY ALL HE ISOLATED SHOWER
ACTIVITY OVER THE MOUNTAINS HAS DISSIPATED AND NO SHOWERS ARE
SHOWING UP ANYWHERE IN THE REGION. WILL WATCH A WEAK WAVE EVIDENT
ON SATELLITE IMAGERY MOVING ESE ACROSS WEST VA. HRRR TRIES TO
DEVELOP A FEW SHOWERS ASSOCIATED WITH THIS WAVE AS IT MOVES INTO
CENTRAL VA BETWEEN 07-11Z. BELIEVE THE HRRR IS OVERDOING THE
DEVELOPMENT...THOUGH THE RAP ALSO HINTS THAT A ISOLATED SHOWER OR
TWO MAY DEVELOP. THERE IS NOT MUCH CONFIDENCE IN ANY EARLY MORNING
SHOWER ACTIVITY...BUT HAVE PUT A MENTION OF AN ISOLATED SHOWER IN
THE FORECAST NORTH AND WEST OF RIC OVERNIGHT. MOST OF THE AREA IF
NOT ALL WILL REMAIN DRY OVERNIGHT. LOWS TONIGHT MAINLY IN THE
UPPER 60S TO LOWER 70S. OVERALL...EXPECT LESS FOG THAN PAST 2
NIGHTS AS LOW LEVEL FLOW SHIFTS MORE TO THE S/SW OVERNIGHT (SOME
PATCHY FOG POSSIBLE MAINLY OVER INTERIOR SE VA/NE NC).
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
COMBINATION OF HIGH PRESSURE OFF THE COAST AND A DEEPENING LOW
PRESSURE SYSTEM TRACKING THROUGH THE GREAT LAKES AND ERN CANADA
WILL ALLOW WINDS TO SHIFT TO THE SSW. TEMPERATURES WILL WARM A FEW
DEGREES OVER TODAY`S READINGS...WITH LOWER-MID 90S ALONG/WEST OF
THE I-95 CORRIDOR...TO UPPER 80S TO LOWER 90S FARTHER EAST. BULK
OF FORCING FOR SHOWERS/TSTMS LOOKS TO STAY N OF AKQ CWA FOR THE
MOST PART SO WILL FAVOR THE DRIER GFS OVER THE WETTER NAM
SOLUTION. WILL CARRY A 30% POP OVER THE FAR NORTH...WITH 20% POPS
INTO CENTRAL VA AND DRY ACRS APPROXIMATELY THE SOUTHERN 1/2 OF THE
CWA.
DEEP UPPER LOW OVER MANITOBA LOOKS TO PUSH A STRONG SHORTWAVE
SE THROUGH THE UPPER MIDWEST INTO THE WRN LAKES ON MON. THIS
ALLOWS LOW LEVEL FLOW FROM THE SW TO INCREASE FURTHER. SPC HAS NW
1/3 OF CWA OUTLINED FOR SLIGHT RISK FOR SEVERE TSTMS ALTHOUGH MUCH
UNCERTAINTY REMAINS GIVEN THIS IS 2 DAYS OUT. A STRONG SW FLOW IN
BOUNDARY LAYER OFTEN DRIES AKQ CWA OUT (ESPECIALLY SE VA/NE NC).
FOR NOW...WILL MAINTAIN HIGH CHC POPS DEVELOPING BY MON AFTN OVER
THE NW COUNTIES TAPERED TO ONLY 20% POPS IN SE VA/NE NC (THINK GFS
DEPICTION OF AM SHOWERS IN THE SE IS OVERDONE). HIGHS LOWER TO MID
90S MOST AREAS (UPPER 80S TO LOWER 90S AT THE BEACHES). POPS
ACTUALLY MAY INCREASE SOMEWHAT MON EVENING ALL THE WAY TO THE
COAST SO WILL HAVE AT LEAST 30% POPS ALL ZONES. WARM/HUMID MON
NIGHT W/ LOWS MAINLY 70-75 F. BY TUE...COLD FRONT MOVES CLOSER TO
THE REGION AND UPPER LEVEL SUPPORT INCLUDING RRQ FORCING FROM THE
UPPER JET ARRIVES. WILL CARRY LIKELY POPS BY AFTN ALL ZONES...SOME
SEVERE POTENTIAL WILL TEND TO TRANSITION TO MAINLY A HEAVY RAIN
THREAT TUE NIGHT. HIGHS IN THE UPPER 80S TO LOWER 90S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS AN ANOMALOUS TROUGH DEVELOPS OVER THE ERN CONUS...HEIGHT FALLS
AND INCREASING WINDS ALOFT WILL RESULT IN BETTER FORCING FOR ASCENT
OVER THE LOCAL AREA. STRONG SPEED MAX ROUNDS THE DEEP CLOSED LOW
OVER THE GREAT LAKES TUES...EJECTING THE LOW NEWD INTO SE CANADA.
THE COLD FRONT DROPS INTO THE REGION TUES NIGHT. STRONGEST DYNAMICS
LIFT WELL NORTH OF THE REGION WITH THE CLOSED LOW...BUT HEIGHT FALLS
AND PERTURBATIONS IN THE WSW FLOW WILL RESULT IN SCT-NUMEROUS
SHOWERS/THUNDERSTORMS. STRONG TO SEVERE THUNDERSTORMS ALSO POSSIBLE
AS MODELS DEPICT MARGINAL SHEAR AND MLCAPE > 2000 J/KG. ANOMALOUS
TROUGH WILL PUSH THE SRN PORTION OF THE FRONT INTO THE DEEP
SOUTH...BUT THE ERN PORTION LIKELY STALLING OVER/OFF THE
MID-ATLANTIC COAST AS AN ANOMALOUS UPPER RIDGE REMAINS PARKED OVER
THE WRN ATLANTIC. WILL MAINTAIN ELEVATED POPS WEDS ACROSS THE SE AS
THE FRONT WILL LIKELY LINGER OVER THE REGION. HIGHS EXPECTED IN THE
LOW TO MID 80S FOR THE WEEK AFTER FRONTAL PASSAGE. SFC HIGH
PRESSURE WILL BE SLOW TO BUILD INTO THE REGION IN WAKE OF THE FRONT
AS UPPER TROUGH REMAINS OVER THE ERN CONUS. MODEL GUIDANCE DEPICTING
THE HIGH RIDGING SOUTH ACROSS THE MID-ATLANTIC CREATING NE/ENE
WINDS. THIS SETUP CAN CAUSE DAYTIME TEMPS TO BE BELOW CLIMO WITH
CLOUDY CONDITIONS. THE STALLED FRONTAL BOUNDARY REMAINS ACROSS THE
SE THROUGH THE WEEKEND AND WITH A PASSING SHORTWAVE TROUGH...SHOWERS
AND THUNDERSTORMS MAY BE POSSIBLE SAT NIGHT INTO SUN.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
SURFACE HIGH PRESSURE CONTS TO DOMINATE THE REGION WITH VFR CONDS
AND LIGHT SE TO S WINDS. EXPECT VFR CONDS THRU 06Z WITH NO EXPECTED
FLIGHT HAZARDS. WINDS DROP OFF ENOUGH LATER TONIGHT TO ALLOW SOME
LIGHT FOG TO DEVELOP AT ATT TERMINALS BUT KORF...WERE ENOUGH WIND
EXPECTED TO MINIMIZE FOG THREAT. ATTM...HAVE TEMPO IFR ONLY AT
KSBY. SHOULD WINDS DROP OFF MORE THAN EXPECTED...FOG COULD BE A
LITTLE MORE DENSE AT KSBY/KPHF. WINDS BECOME SSW ON SUNDAY AS THE
HIGH MOVES OFFSHORE. HAVE MAINTAINED DRY FORECAST IN
TERMINALS...ALTHO NAM WOULD SUGGEST POTENTIAL FOR SCATTERED TSTMS
AT KRIC/KPHF/KORF IN THE 19Z TO 22Z TIME FRAME.
WEAK SHORTWAVE TROUGH MOVING ACROSS THE AREA MONDAY AFTN/EVENING
COULD PRODUCE ADDITIONAL SHWRS/TSTMS. A COLD FRONT WILL BRING THE
POTENTIAL FOR SHWRS/TSTMS TUESDAY INTO WEDNESDAY.
&&
.MARINE...
CALM CONDITIONS WILL CONTINUE TODAY AS A STATIONARY BOUNDARY REMAINS
SOUTH OF THE AKQ MARINE WATERS. MEANWHILE...BROAD AREA OF HIGH
PRESSURE STRETCHES FROM NEW ENGLAND THROUGH THE SE CONUS TODAY. FLOW
RETURNS TO THE SOUTH LATE SAT NIGHT AND SUN AS THE HIGH SLIDES
OFFSHORE...INCREASING SLIGHTLY TO 10-15 KT GUSTING TO 18-20 KT
SUNDAY EVENING. SLY FLOW PERSISTS THROUGH EARLY NEXT WEEK. A COLD
FRONT WILL APPROACH THE WATERS LATE MONDAY...CROSSING THE WATERS WED
MORNING. PERSISTENT SLY FLOW MAY PUSH SEAS TO 5-6 FT ACROSS THE
NORTHERN WATERS BY MONDAY NIGHT. HIGH PRESSURE BUILDS IN POST FRONT
BRIEFLY TURNING WINDS TO THE NE WITH THE WINDS BECOMING WEAK AND
VARIABLE AS THE HIGH BUILDING EAST AND AN AREA OF LOW PRESSURE FORMS
ALONG THE STALLED FRONTAL BOUNDARY ACROSS THE SOUTHEAST.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...JDM/LKB/JAO
LONG TERM...DAP
AVIATION...WRS
MARINE...DAP
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1138 PM EDT SAT JUL 12 2014
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 1138 PM EDT SAT JUL 12 2014
CONVECTION IS EXPANDING IN COVERAGE AND EVOLVING PRETTY MUCH AS
EXPECTED LATE THIS EVENING. A BAND OF STORMS IS TAKING SHAPE FROM
NEAR HOLLAND...TO KENOSHA WI...AND THEN DOWN THROUGH METRO
CHICAGO. RAP MODEL INDICATES LLJ CONTINUES TO RAMP UP AND REGIONAL VWP
PROFILES AT LOT...IWX...AND DVN INDICATE 40 KNOTS AT 850 MB WITH
THE CORE OF WIND IN THE MIDDLE OF THESE SITES AROUND 45 TO 50
KNOTS.
INSTABILITY IS THE GREATEST NEAR CHICAGO WITH AROUND 3000 J/KG OF
MU CAPE WITH A DECENT GRADIENT TRENDING DOWN TO THE NORTH AND
EAST. 1000 J/KG IS NOW COMING INTO THE SW CORNER OF THE CWFA. THE
LLJ WILL CONTINUE TO MOVE ENE INTO THE AREA AS THE WAVE NEAR
CHICAGO MOVES E. THE RAP MODEL CONTINUES TO INDICATE THAT
1000-1500 J/KG OF CAPE WILL GET TO I-94 WITH LESSER AMOUNTS TO THE
NORTH BEFORE IT TAILS OFF LATER TONIGHT AS THE LLJ SHIFTS EAST OF
THE AREA.
50 KNOTS OF EFFECTIVE SHEAR IS IN PLACE NEAR CHICAGO AND IS
HELPING THE ORGANIZATION OF THE STORMS. 30-40 KNOTS OF 0-1KM SHEAR
SUPPORTS THE CONTINUED THINKING OF A POSSIBLE TORNADO NEAR THE
WARM FRONT WHICH LOOKS TO BE FROM CHICAGO TO GARY TO SW OF FORT
WAYNE. THIS IS COMING TO FRUITION WITH SOME INDICATIONS OF
ROTATION IN WI/IL AND OVER LAKE MICHIGAN. LOW LCL/S OF 500-750 M ALSO
WOULD HELP SUPPORT A POSSIBLE TORNADO.
&&
.SYNOPSIS...
ISSUED AT 231 PM EDT SAT JUL 12 2014
A COLD FRONT WILL PUSH THROUGH THE REGION LATE TONIGHT INTO SUNDAY
MORNING. THIS SYSTEM WILL TRIGGER THUNDERSTORMS. SOME OF THE
STORMS WILL CONTAIN HEAVY RAIN AND A FEW COULD TURN SEVERE. A
DRIER AIRMASS WILL FILTER IN FROM THE NORTHWEST ON SUNDAY. A COOL
CANADIAN AIRMASS ARRIVES FOR EARLY NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 231 PM EDT SAT JUL 12 2014
CHALLENGE IN THE SHORT TERM DEALS WITH THE SEVERE POTENTIAL
TONIGHT. LOOKS LIKE AN INCREASED POTENTIAL FOR SEVERE WEATHER WILL
EXIST.
THE FORCING FROM AN APPROACHING MID LEVEL WAVE COMBINES WITH THE
INSTABILITY AND A LOW LEVEL JET TO TRIGGER THUNDERSTORMS TONIGHT.
GOOD DIFFLUENCE WAS NOTED AT THE TROP. THE MAIN TIMEFRAME LOOKS
TO BE 03Z TO 08Z. DAMAGING WINDS SEEMS LIKE THE MAIN THREAT WITH A
50 KNOT LOW LEVEL JET. GIVEN THE HIGH 0 TO 1 KM SHEAR...LOW LCL
AND LOW LEVEL CAPE...WOULD NOT RULE OUT A TORNADO AS WELL. THIS
RISK SEEMS HIGHEST AROUND INTERSTATE 94 GIVEN THE FORECASTED LOW
LEVEL JET LOCATION. HAZARDS WERE UPDATED IN THE HWO AND SOCIAL
MEDIA POSTS. HIGH POPS ALL ZONES. BY 09Z NORTHWEST COUNTIES SHOULD
SEE A DIMINISHING TREND TO THE PRECIPITATION.
FORECAST SOUNDINGS FOR SUNDAY AFTERNOON INTO SUNDAY NIGHT SHOULD A
LIMITED RISK FOR PRECIPITATION. WITH MOST LOCATIONS TO REMAIN
DRY...I LOWERED POPS.
THE UPPER LOW PIVOTS THROUGH THE REGION ON MONDAY. THIS WILL ACT
TO KEEP IT COOL WITH A RISK FOR A THUNDERSTORM...ESPECIALLY IN THE
AFTERNOON.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 231 PM EDT SAT JUL 12 2014
THE LONG TERM PERIOD WILL SEE A STEADY MODERATING TREND AS THE DEEP
UPPER TROUGH MOVES SLOWLY EASTWARD. VERY COLD H5 TEMPS NEAR -19C
WILL RESULT IN UNSTABLE CONDITIONS. THIS TIME OF YEAR THAT USUALLY
MEANS PM STORMS WITH SMALL HAIL. TRENDED CLOUD COVER UPWARD DURING
THE AFTERNOON TUESDAY OVER INLAND AREAS. INCLUDED A THUNDER MENTION
TUESDAY AFTERNOON AND WEDNESDAY AFTERNOON. BY THURSDAY THE UPPER LOW
WILL BE EAST OF THE CWA AND THE PCPN THREAT WILL BE GREATLY
DIMINISHED. A VERY CHILLY DAY IS EXPECTED TUESDAY WITH HIGHS IN THE
MID 60S. HOWEVER...BY THE WEEKEND TEMPS WILL BE BACK TO AROUND 80.
THE LAST HALF OF THE PERIOD LOOKS DRY AS SFC HIGH PRESSURE WILL
DEVELOP OVER LOWER MICHIGAN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 757 PM EDT SAT JUL 12 2014
MVFR CONDITIONS ARE EXPECTED TO BECOME MORE WIDESPREAD THIS
EVENING AS RAIN CONTINUES TO INCREASE IN COVERAGE. TSTM POTENTIAL
WILL INCREASE SIGNIFICANTLY BETWEEN 02Z AND 04Z... LASTING 2-4
HOURS AT MOST LOCATIONS. POTENTIAL EXISTS FOR SOME STRONG TO SVR
STORMS WITH TORRENTIAL DOWNPOURS... ESPECIALLY ALONG THE I-94
CORRIDOR. THIS COULD LEAD TO AREAS OF IFR/LIFR VSBYS AS WELL AS A
BRIEF WIND GUST OVER 30KTS.
IFR CIGS WILL PROBABLY BECOME COMMON FOR A FEW HOURS LATE TONIGHT
BEHIND THE DEPARTING RAIN BEFORE CONDITIONS IMPROVE TO VFR BY MID
TO LATE MORNING SUNDAY. SFC WINDS WILL INCREASE OUT OF THE WEST TO
12-22 KTS FOR SUNDAY AFTERNOON.
&&
.MARINE...
ISSUED AT 231 PM EDT SAT JUL 12 2014
OVERALL CONDITIONS ARE EXPECTED TO REMAIN BELOW CRITERIA FOR
HEADLINES. CONVECTION COULD LEAD TO BRIEF PERIOD OF STRONGER WINDS
AND HIGHER WAVES.
&&
.HYDROLOGY...
ISSUED AT 231 PM EDT SAT JUL 12 2014
AT THIS TIME NO WATCH FOR FLOODING. THE THOUGHT IS THAT THE STORMS
WILL TRACK STEADILY EAST...ROUGHLY 03Z TO 08Z. MOST LOCATIONS WILL
SEE A STORM THAT LASTS FOR AN HOUR OR PERHAPS TWO. GENERALLY AN
INCH OF RAIN WILL ACCOMPANY THE STORMS...BUT LOCAL AMOUNTS COULD
TOP 2 INCHES. URBAN AND POOR DRAINAGE FLOODING APPEARS TO BE THE
MAIN RISK FROM THESE STORMS. PWAT VALUES OVER 2 INCHES AND GOOD
FORCING SUPPORT MOST LOCATIONS SEEING THESE HEAVY DOWNPOURS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
MESOSCALE...NJJ
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...93
AVIATION...MEADE
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
818 PM EDT SAT JUL 12 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 422 PM EDT SAT JUL 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID/UPPER LEVEL LOW FROM
WRN HUDSON BAY INTO NRN MANITOBA. A LINE OF SHRA/TSRA THROUGH SRN
MANITOBA WAS ASSOCIATED WITH A PROMINENT SHORTWAVE TROUGH AND COLD
FRONT NEARING WINNIPEG. FARTHER SOUTH...A WEAKER SHRTWV FROM ERN MN
INTO WRN WI COMBINED WITH MORE ABUNDANT MOISTURE (PWAT VALUES AROUND
1.5 INCH) SUPPORTED AN AREA OF SHRA AND ISOLD TSRA FROM SE MN INTO
CNTRL AND NRN WI. CONVERGENCE ALON LAKE SUPERIOR AND LAKE MICHIGAN
LAKE BREEZE BOUNDARIES WHERE MLCAPE HAS CLIMBED TO NEAR 1K J/KG HAS
TRIGGERED ISOLD ISOLD SHRA/TSRA FROM FAR NW DELTA COUNTY INTO NRN
SCHOOLCRAFT COUNTY.
TONIGHT...EXPECT ADDITIONAL SHRA/TSRA DEVELOPMENT ALONG THE LAKE
BREEZE BOUNDARIES INLAND FROM CNTRL INTO ERN UPPER MI INTO THIS
EVENING TIL THE LOSS OF DAYTIME HEATING. THERE IS MORE UNCERTAINTY
REGARDING THE SHRA/TSRA OVER NRN WI AS SEVERAL HIGH RES MODELS
SUGGEST THAT THEY MAY EXPAND INTO SRN UPPER MI AND POSSIBLE TOWARD
MQT/P53 AS THE WI SHRTWV ADVANCES TO THE EAST.
HOWEVER...RADAR/SATELLITE TRENDS WOULD FAVOR KEEPING HIGHER
COVERAGE/POPS MAINLY OVER THE FAR S/SE CWA. ADDITIONAL SHRA AND
POSSIBLY ISOLD THUNDER WILL BE POSSIBLE AS THE MANITOBA FRONT/SHRTWV
MOVE INTO UPPER MI OVERNIGHT. HOWEVER...SINCE THE PCPN FOCUS ARRIVES
WHEN MUCAPE HAS DIMINISHED TO 400 J/KG OR LESS...ONLY SLIGHT
CHANCE POPS WERE INCLUDED.
SUNDAY...AFTER ANY LINGERING SHRA DEPART FROM THE FAR ERN CWA
EARLY...BREEZY AND COOLER WEATHER IS EXPECTED BEHIND THE COLD FRONT.
HOWEVER...WITH WNW WINDS AND 850 MB TEMPS IN THE 6C-8C RANGE...MAX
READINGS SHOULD STILL CLIMB INTO THE UPPER 60S TO LOWER 70S FROM NW
TO SE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 422 PM EDT SAT JUL 12 2014
MAIN CONCERNS DURING THIS TIME PERIOD WILL BE RAIN CHANCES MONDAY
AND TUESDAY WITH COOLER THAN NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK.
SUNDAY NIGHT THROUGH TUESDAY...THE MAIN SURFACE LOW WILL BE CENTERED
OVER JAMES BAY AROUND 00Z/14 WHILE THE MAIN UPPER LEVEL
ENERGY/CLOSED LOW WILL REMAIN OVER THE ONTARIO/MANITOBA BORDER. THIS
WILL PLACE THE UPPER PENINUSLA AND MUCH OF THE EASTERN HALF OF THE
COUNTRY IN BROAD UPPER LEVEL TROUGHING. THE BREAK IN PRECIPITATION
WILL CONTINUE SUNDAY NIGHT AS A BRIEF WEDGE OF DRY AIR PUSHES
THROUGH THE CWA. BY LATE SUNDAY NIGHT...DEEPER MOISTURE...ASSOCIATED
WITH THE UPPER LEVEL 500MB LOW IN SOUTHERN CANADA...WILL APPROACH
THE FAR WESTERN U.P. IN ADDITION...A SURFACE TROUGH WILL EXTEND
SOUTHWESTWARD FROM THE PARENT SURFACE LOW INTO NORTHERN MN. THIS
WILL HELP TO KEEP THE BETTER FORCING TO THE NORTHWEST OF THE U.P.
SUNDAY NIGHT. THE SURFACE LOW WILL SHIFT FROM JAMES BAY 12Z/14 TO
CENTRAL QUEBEC BY 18Z/15. THIS WILL ALLOW THE SURFACE TROUGH TO PUSH
ACROSS THE U.P. THROUGH THE DAY MONDAY AND INTO THE LOWER GREAT
LAKES MONDAY NIGHT. AT THE SAME TIME THE UPPER LEVEL 500MB CLOSED
LOW OVER NORTHERN MN WILL SWEEP ACROSS THE U.P. AND REACH THE
QUEBEC/SOUTHERN ONTARIO BORDER BY 18Z/15. AS FAR AS PRECIP
GOES...HAVE KEPT THE TREND OF INCREASING POPS THROUGH THE DAY
MONDAY...DUE LARGELY TO THE CONVERGENCE ALONG THE SURFACE
TROUGH/INCREASED 1000-500MB RH/VORT MAX PRESSING THROUGH THE U.P.
ALONG WITH DIURNAL HEATING.
ONCE THE BETTER FORCING EXITS THE REGION MONDAY
EVENING...PRECIPITATION CHANCES WILL SLOWLY DIMINISH. STILL KEPT
ONGOING CHANCES OF SHOWERS IN THE FORECAST THROUGH TUESDAY AS THE
UPPER LEVEL 500MB AND INCREASED MOISTURE LINGERS ACROSS THE AREA.
THERE ARE SOME DIFFERENCES IN THE MODELS...WITH THE GFS HAS BEEN
MORE PROGRESSIVE WITH THE UPPER LEVEL LOW WHILE THE EC/GEM KEEP THE
UPPER LEVEL LOW OVER THE U.P. THROUGH TUESDAY AFTERNOON BEFORE
EXITING THE CWA BY 00Z/16. THE 12Z RUN OF THE GFS IS COMING INTO
BETTER AGREEMENT WITH THE EC/GEM LENDING MORE SUPPORT TO THESE
SOLUTIONS. TUESDAY WILL LIKELY END UP BEING THE COOLEST DAY OF THE
WEEK WITH THE UPPER LEVEL LOW PASSING THROUGH THE AREA PULLING 850MB
TEMPS DOWN TO AROUND 4 TO 5C. HIGHS WILL STRUGGLE TO GET INTO THE
60S ACROSS MANY AREAS...WHILE NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 77 DEGREES.
TUESDAY NIGHT THROUGH THE REST OF THE EXTENDED...VERY QUIET WEATHER
EXPECTED THROUGH THIS TIME PERIOD WITH SLOWLY MODERATING
TEMPERATURES THROUGH THE UPCOMING WEEKEND AS UPPER LEVEL RIDGING
BEGINS TO BUILD BACK INTO THE REGION. AT THE SURFACE...BROAD HIGH
PRESSURE WILL BUILD ACROSS THE UPPER GREAT LAKES REGION AND LINGER
THROUGH FRIDAY NIGHT. THE GFS KEEPS THE HIGH POSITIONED OVER THE
AREA THROUGH SATURDAY WHILE THE EC SLIDES THE HIGH
EASTWARD...ALLOWING A SURFACE LOW AND UPPER LEVEL TROUGH ALONG WITH
INCREASED MOISTURE TO PUSH INTO THE FAR WESTERN CWA. WITH MODEL
DIFFERENCES WILL STICK WITH A CONSENSUS OF THE MODELS FOR
SATURDAY..WHICH BRINGS A CHANCE OF SHOWERS TO THE FAR WESTERN U.P.
DURING THE AFTERNOON AND EVENING HOURS SATURDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 818 PM EDT SAT JUL 12 2014
VFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD AT
KIWD/KCMX/KSAW. HOWEVER...SINCE PCPN HAS OCCURRED AT KSAW...IT`S
POSSIBLE FOG AND STRATUS COULD DEVELOP FOR A TIME TONIGHT BEFORE
WINDS PICK UP AHEAD OF FAST APPROACHING COLD FRONT. ALTHOUGH SHRA
ALONG COLD FRONT WILL BE DISSIPATING...COLD FRONT MAY STILL BRING
-SHRA AND SOME GUSTY WINDS TO KIWD/KCMX BTWN ROUGHLY 05Z AND 07Z.
OTHERWISE...BEHIND COLD FRONT...GUSTY WINDS ARE EXPECTED SUN WITH
ALL TERMINALS GUSTING 20-30KT. STRONGEST WINDS WILL BE AT KCMX
WHICH IS MORE EXPOSED WITH A WNW WIND.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT SAT JUL 12 2014
SOUTHWEST WINDS THIS EVENING WILL SHIFT SHARPLY TO THE WEST LATE
TONIGHT AS A COLD FRONT ARRIVES. THERE MAY BE SOME WIND GUSTS UP
TO 25 KTS AT LEAST BRIEFLY LATE TONIGHT OVER WEST AND NORTH CENTRAL
LK SUPERIOR BEHIND THE FRONT. AREAS OF FOG ARE CURRENTLY OVER LAKE
SUPERIOR WILL DISSIPATE ON SUNDAY IN WAKE OF THE STRONGER FRONT AS
STRONG DRY ADVECTION TAKES OVER. EXPECT NORTHWEST WINDS TO 20 KTS AT
TIMES INTO EARLY THIS WEEK IN WAKE OF THE COLD FRONT AND AS HIGH
PRESSURE BUILDS OVER THE NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
432 PM EDT FRI JUL 11 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 429 PM EDT FRI JUL 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL PATTERN THROUGH THE
NRN CONUS BETWEEN A TROUGH OVER CNTRL CANADA AND A RIDGE OVER THE
SRN PLAINS. A WEAK SHORTWAVE TROUGH OVER LAKE SUPERIOR INTO CNTRL
UPPER MI HELPED PRODUCE SOME LIGHT SHOWERS ACROSS THE CWA TODAY.
SCT/ISOLD SHRA/TSRA FROM NEAR KINL INTO N CNTRL MN HAD DEVELOPED
ALONG A COLD FRONT/TROUGH AHEAD OF ANOTHER WEAK SHRTWV MOVING
THROUGH NORTH DAKOTA. MOSTLY CLOUDY SKIES OVER UPPER MI HAD LIMITED
TEMPS TO THE LOWER TO MID 70S AND LIMITED MLCAPE VALUES TO LESS THAN
400 J/KG.
TONIGHT...EXPECT THAT SHRA/TSRA OVER NRN MN WILL EXPAND IN COVERAGE
AND MOVE TOWARD UPPER MI. HOWEVER...WITH ONLY MARGINAL INSTABILITY
FCST OVER THE AREA...MUCAPE INTO THE 400-800 J/KG RANGE...THE
CONVECTION SHOULD WEAKEN WITH ONLY ISOLD TSRA. SCT SHRA COVERAGE
WITH CHANCE POPS WAS MENTIONED GIVEN THE WEAK FORCING ASSOCIATED
WITH THE FRONT AND SHRTWV SLIDING THROUGH THE NRN GREAT LAKES. THE
REMAINING SHOWERS ARE EXPECTED TO MOVE INTO THE ERN CWA LATE THIS
EVENING AND DIMINISH FROM WEST TO EAST OVERNIGHT.
SATURDAY...THE WEAKENING COLD FRONT THROUGH UPPER MI WILL PROVIDE A
BOUNDARY/FOCUS FOR POTENTIAL SHRA/TSRA DEVELOPMENT...ESPECIALLY WITH
ONSET OF STRONGER DAYTIME HEATING. EXPECT THE GREATEST PCPN COVERAGE
OVER THE SOUTH AND THROUGH ERN UPPER MI WHERE THE HIGHER RES MODELS
SUGGEST THE LOW LEVEL CONV WILL BE STRONGEST. MLCAPE VALUES TO NEAR
1K J/KG...PER GEM-REGIONAL AND GFS COMBINED WITH 0-6KM SHEAR VALUES
OF 35-40 KNOTS COULD SUPPORT SOME STRONG AND POSSIBLY SEVERE STORMS
IF CLOUD DEPENDENT INSTABILITY IS REALIZED. THE MODELS HAVE ALSO SHOWN A
CONSISTENT SIGNAL THAT SHRA/TSRA WILL MOVE INTO WI ASSOCIATED WITH
STRONGER SHORTWAVE TROUGH. THERE IS STILL TIMING/POSITION UNCERTAINTY
ON HOW IT WOULD AFFECT MAINLY SRN UPPER MI BY LATE AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 431 PM EDT FRI JUL 11 2014
THE MAIN STORY IN THE LONG TERM CONTINUES TO BE THE SEPTEMBER-LIKE
CONDITIONS EXPECTED ACROSS THE UPPER GREAT LAKES EARLY NEXT WEEK.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...A DEEP MID-LEVEL LOW OVER FAR
SOUTHWEST HUDSON BAY WILL CONTINUE ITS TREK SOUTHWARD AT THE
BEGINNING OF THE PERIOD. CONVECTIVE POTENTIAL ACROSS THE SOUTHEAST
HALF FOR SATURDAY NIGHT WILL DEPEND HEAVILY ON BOTH THE AMOUNT OF
DIURNAL HEATING SATURDAY AND THE LOCATION OF THE DECAYING LOW-LEVEL
CONVERGENCE ZONE. WHILE MCS ACTIVITY LOOKS TO BE MOST PRONOUNCED
ALONG THE NOSE OF A DEVELOPING LOW-LEVEL JET ACROSS WI SATURDAY
AFTERNOON AND EVENING...RESIDUAL 305-315K ISENTROPIC LIFT NORTH OF
THE LOW-LEVEL BOUNDARY MAY BE ENOUGH TO TAP INTO REMAINING MUCAPE OF
AROUND 500 J/KG AS NOTED BY BOTH THE 12Z NAM AND 12Z GEM. ANY
THUNDER ACTIVITY SHOULD REMAIN WEAK THIS FAR NORTH GIVEN A STABLE
SFC LAYER AND OVERALL LIMITED INSTABILITY. HOWEVER...A FEW STRONGER
GUSTS CANNOT BE RULED OUT IN THE EARLY EVENING HOURS FAR SOUTH
CENTRAL WITH ANY STORM ROOTED ALONG THE SFC CONVERGENCE ZONE.
A MID-LEVEL TROUGH AXIS ASSOCIATED WITH THE DEEP LOW WILL CROSS THE
CWA FROM WEST TO EAST LATE SATURDAY NIGHT INTO SUNDAY. WITH LITTLE
ADDITIONAL SUPPORT AND GENERALLY DRY CONDITIONS...ONLY SOME ISOLATED
SHOWER ACTIVITY IS EXPECTED. AFTER THE TROUGH PASSAGE ON
SUNDAY...SKIES LOOK TO BECOME MOSTLY CLEAR FOR A 12-18 HOUR WINDOW.
THIS WILL ALLOW FOR INCREASED MIXING ACROSS THE WEST...WITH WESTERLY
GUSTS TO 25 MPH ACROSS THE KEWEENAW.
MONDAY AND TUESDAY...BY MONDAY MORNING...THE MID-LEVEL LOW WILL
SPLIT INTO TWO WAVES OVER ONTARIO. THE EASTERN SEGMENT OVER
SOUTHERN JAMES BAY WILL EJECT NORTHEASTWARD ACROSS QUEBEC THROUGH
MONDAY. MEANWHILE...THE WESTERN SEGMENT WILL BE TRACKING
SOUTHEASTWARD ACROSS THE BOUNDARY WATERS OF MN AROUND 12Z MONDAY.
THIS WESTERN EXTENSION WILL BECOME STACKED UPWARD FROM H7...SO
PROGRESSION OF THE SYSTEM WILL BE QUITE SLOW. THE MID/UPPER-LOW IS
PROGGED TO TRACK FROM NEAR DLH MONDAY AFTERNOON TO NEAR GRB BY
TUESDAY AFTERNOON. GIVEN THE OVERALL DYNAMICS OF THE SYSTEM...THE
ENTIRE AREA SHOULD SEE AT LEAST SOME SHOWERS DURING THE DAY. ONE
LIMITING FACTOR TO COVERAGE IS A PRESENCE OF DEEP MOISTURE. SOMEWHAT
DRY AIR ABOVE H5 SHOULD KEEP SHOWERS LESS WIDESPREAD AWAY FROM THE
LOW CENTER. SOME DIURNAL HEATING ASSISTANCE WILL ALSO ALLOW FOR
GREATER COVERAGE AWAY FROM THE GREAT LAKES. THEREFORE...THE BEST
COVERAGE IS EXPECTED ALONG THE WI BORDER...WHERE LIKELY POPS HAVE
BEEN INTRODUCED.
TEMPS WILL BE QUITE COOL FOR MID-JULY...WITH H8 TEMPS AT OR BELOW
5C. WITH CLOUDY AND SHOWERS AROUND...HIGHS WILL STRUGGLE TO GET OUT
OF THE 50S ACROSS MUCH OF THE CWA BOTH MONDAY AND TUESDAY. SOME
LOCALES ALONG LAKE SUPERIOR MAY EVEN FAIL TO REACH 50. THESE NUMBERS
ARE 25 DEGREES BELOW AVERAGE...AND WILL LIKELY SET RECORD LOW
MAXIMUM TEMPS ACROSS THE AREA.
SHOWERY ACTIVITY WILL CONTINUE INTO TUESDAY WITH THE PASSAGE OF A
DEFORMATION/FGEN REGION ON THE BACKSIDE OF THE MID/UPPER LOW. THESE
SHOWERS WILL BE SLOW TO MOVE EASTWARD AS THE LOW ONLY REACHES
NORTHERN LAKE HURON BY LATE TUESDAY NIGHT.
WEDNESDAY THROUGH FRIDAY...THE GFS ADVERTISES A MUCH QUICKER
DEPARTURE OF THE MID-LEVEL LOW THAN THE ECMWF/GEM. THIS HAS
IMPLICATIONS ON THE AMOUNT OF MOISTURE AVAILABLE FOR CONTINUED CLOUD
COVER AND HIGH TEMPS ACROSS THE AREA. OTHERWISE...THE STOUT RIDGE
ACROSS THE WESTERN STATES AND PROVINCES THAT DEVELOPED IN RESPONSE
TO THE DEEP EASTERN TROUGH WILL BEGIN TO SHIFT ACROSS THE NORTHERN
PLAINS ON THURSDAY AND THE UPPER GREAT LAKES ON FRIDAY. THIS SHOULD
BRING AN OVERALL QUIET PERIOD OF WEATHER WITH A GRADUAL WARMING
TREND INTO THE WEEKEND. TEMPS LOOK TO BE BACK TO JUST BELOW AVERAGE
BY FRIDAY. HOWEVER...A FEW DIURNAL INLAND SHOWERS COULD BE POSSIBLE
WITH RETURN MOISTURE THURSDAY AFTERNOON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 152 PM EDT FRI JUL 11 2014
A BAND OF LIGHT SHOWERS MOVING THROUGH UPPER MICHIGAN THROUGH EARLY
AFTERNOON IS NOT EXPECTED TO BE HEAVY ENOUGH...PER RADAR TRENDS...TO
REDUCE CONDITIONS TO MVFR. THE NEXT SHOT OF SOME SHRA AND POSSIBLE
TSRA IS EXPECTED THIS EVENING AS A WEAK COLD FRONT APPROACHES FROM
MN. LOCATION AND COVERAGE OF ANY PCPN IS QUITE UNCERTAIN...SO ONLY A
VCNTY SHRA MENTION WAS INCLUDED FOR NOW. LIKE TODAY...CONDITIONS
SHOULD STAY MAINLY VFR INTO SATURDAY MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT FRI JUL 11 2014
SOUTH WINDS OF UP TO 20 KTS...POSSIBLY 25 KTS AT HIGHER PLATFORMS
ABOVE MARINE LAYER...EXPECTED INTO THIS EVENING WILL DIMINISH
OVERNIGHT WITH WINDS SHIFTING TO SW. AS SCT SHOWERS ASSOCIATED WITH A
WEAK COLD FRONT OR TROUGH MOVE THROUGH LAKE SUPERIOR...FOG WILL BE
POSSIBLE ACROSS THE ENTIRE LAKE WITH THE TROUGH PASSAGE. LIGHT WINDS
WILL CONTINUE THROUGH SUNDAY BEFORE ANOTHER TROUGH PASSES
SOUTHEASTWARD ACROSS LAKE SUPERIOR SUNDAY NIGHT. GUSTY NORTHWEST
WINDS TO 20 KNOTS EXPECTED BEHIND THIS TROUGH EARLY NEXT WEEK AS HIGH
PRESSURE BUILDS OVER THE NORTHERN PLAINS. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EDT FRI JUL 11 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 429 PM EDT FRI JUL 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A ZONAL PATTERN THROUGH THE
NRN CONUS BETWEEN A TROUGH OVER CNTRL CANADA AND A RIDGE OVER THE
SRN PLAINS. A WEAK SHORTWAVE TROUGH OVER LAKE SUPERIOR INTO CNTRL
UPPER MI HELPED PRODUCE SOME LIGHT SHOWERS ACROSS THE CWA TODAY.
SCT/ISOLD SHRA/TSRA FROM NEAR KINL INTO N CNTRL MN HAD DEVELOPED
ALONG A COLD FRONT/TROUGH AHEAD OF ANOTHER WEAK SHRTWV MOVING
THROUGH NORTH DAKOTA. MOSTLY CLOUDY SKIES OVER UPPER MI HAD LIMITED
TEMPS TO THE LOWER TO MID 70S AND LIMITED MLCAPE VALUES TO LESS THAN
400 J/KG.
TONIGHT...EXPECT THAT SHRA/TSRA OVER NRN MN WILL EXPAND IN COVERAGE
AND MOVE TOWARD UPPER MI. HOWEVER...WITH ONLY MARGINAL INSTABILITY
FCST OVER THE AREA...MUCAPE INTO THE 400-800 J/KG RANGE...THE
CONVECTION SHOULD WEAKEN WITH ONLY ISOLD TSRA. SCT SHRA COVERAGE
WITH CHANCE POPS WAS MENTIONED GIVEN THE WEAK FORCING ASSOCIATED
WITH THE FRONT AND SHRTWV SLIDING THROUGH THE NRN GREAT LAKES. THE
REMAINING SHOWERS ARE EXPECTED TO MOVE INTO THE ERN CWA LATE THIS
EVENING AND DIMINISH FROM WEST TO EAST OVERNIGHT.
SATURDAY...THE WEAKENING COLD FRONT THROUGH UPPER MI WILL PROVIDE A
BOUNDARY/FOCUS FOR POTENTIAL SHRA/TSRA DEVELOPMENT...ESPECIALLY WITH
ONSET OF STRONGER DAYTIME HEATING. EXPECT THE GREATEST PCPN COVERAGE
OVER THE SOUTH AND THROUGH ERN UPPER MI WHERE THE HIGHER RES MODELS
SUGGEST THE LOW LEVEL CONV WILL BE STRONGEST. MLCAPE VALUES TO NEAR
1K J/KG...PER GEM-REGIONAL AND GFS COMBINED WITH 0-6KM SHEAR VALUES
OF 35-40 KNOTS COULD SUPPORT SOME STRONG AND POSSIBLY SEVERE STORMS
IF CLOUD DEPENDENT INSTABILITY IS REALIZED. THE MODELS HAVE ALSO SHOWN A
CONSISTENT SIGNAL THAT SHRA/TSRA WILL MOVE INTO WI ASSOCIATED WITH
STRONGER SHORTWAVE TROUGH. THERE IS STILL TIMING/POSITION UNCERTAINTY
ON HOW IT WOULD AFFECT MAINLY SRN UPPER MI BY LATE AFTERNOON.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 418 AM EDT FRI JUL 11 2014
UNCERTAINTY STILL EXISTS FOR THE WEEKEND AS SUBTLE SHORTWAVES AND
CONVECTIVE COMPLEXES MAKE FORECASTING DIFFICULT.
FOR SAT...THE LOW PRESSURE SYSTEM OVER CENTRAL CANADA WILL REMAIN
STATIONARY AS A WEAK COLD FRONT MOVES INTO THE CWA. THE FRONT WILL
BE OVER NWRN UPPER MI AT 12Z SAT AND LOOKS TO WASH OUT AS IT MOVE
FARTHER INTO UPPER MI. THINK THERE COULD BE SCATTERED SHOWERS AND
THUNDERSTORMS ALONG THE FRONT OVER NWRN UPPER MI. AM MORE UNCERTAIN
WITH CONVECTIVE CHANCES OVER CENTRAL/ERN UPPER MI AS MODELS SHOW A
CONVECTIVE COMPLEX MOVING S OF THE CWA SOMETIME LATE SAT AFTERNOON
INTO EARLY SAT NIGHT. THE NAM IS THE FARTHEST N WITH SHOWING THE
COMPLEX SKIRTING THE SERN CWA. WHILE THIS CANNOT BE COMPLETELY RULED
OUT...WENT MORE WITH THE CONSENSUS APPROACH IN KEEPING THE COMPLEX
FARTHER S. DEPENDING ON THE STRENGTH/TRACK/TIMING OF THE COMPLEX /IF
IT FORMS/...CONVECTION MAY OR MAY NOT DEVELOP FARTHER N OVER THE
CENTRAL AND ERN CWA. IF CONVECTION TO THE S IS MORE
MINIMAL...CONVECTION MAY BE ABLE TO STRENGTHEN OVER THE SCENTRAL CWA
WHERE CAPE VALUES MAY EVEN RISE TO NEAR 1000J/KG WITH DEEP LAYER
SHEAR AROUND 40KTS.
A STRONGER COLD FRONT MOVES THROUGH ON SUN...WITH MODEL VARIABILITY
WITH THE TIMING OF THAT FRONT...ALTHOUGH THE MAJORITY OF MODELS HAVE
IT PASSING THROUGH MUCH OF THE AREA IN THE MORNING TO EARLY
AFTERNOON. THIS DOES NOT ALLOW MUCH TIME FOR INSTABILITY TO DEVELOP.
THINK THAT SCATTERED SHOWERS WILL DEVELOP ALONG THE FRONT OVER
MAINLY ERN UPPER MI...WHERE AT LEAST SOME HEATING WILL OCCUR BEFORE
THE FRONT...AND A WEAK SHORTWAVE RIDING ALONG THAT FRONT...PASSES
THROUGH. PRECIP CHANCES PUSH S THROUGH THE DAY ALONG WITH THE FRONT.
BY 12Z MON...THE UPPER LOW THAT WAS OVER CENTRAL CANADA WILL BE NEAR
INL. THE LOW WILL THEN SHIFT SE AND ACROSS THE GENERAL AREA INTO
TUE...AND SHOULD BE E OF THE CWA BY WED AT THE LATEST...WITH THE GFS
MOVING IT OUT FAR FASTER THAN THE ECMWF AND GEM-NH. AS THAT UPPER
LOW MOVES IN ON MON...THE COLD CORE BEING OVERHEAD OR NEARBY
COMBINED WITH THE HEIGHT FALLS AND DYNAMICS OF THE SYSTEM WILL LEAD
TO SCATTERED SHOWERS OVER MUCH OF THE AREA ON MON INTO TUE.
WITH HOW ANOMALOUSLY STRONG THE LOW WILL BE...THE BIG STORY IN THE
LONG TERM IS TEMPERATURES. 850MB TEMPS WILL BE COLDEST ON TUE AT
4-5C...RESULTING IN HIGH TEMPERATURES IN THE LOW 50S /OR POSSIBLE
NOT EVEN REACHING 50/ OVER NRN UPPER MI...WITH HIGHS IN THE LOW 60S
OVER SCENTRAL UPPER MI. RECORD LOW HIGH TEMPS FOR TUE AT NWS
MARQUETTE IS DEGREES...WHICH QUITE LIKELY WILL BE WARMER THAN WHAT
WE SEE ON TUE. IN FACT THE COLDEST HIGH TEMP FOR THE MONTH OF JULY
IS 51...AND THAT IS NOT EVEN OUT OF THE REALM OF POSSIBILITIES TO
TIE OR BREAK. ALTHOUGH TEMPS DO WARM WED AND THU...THEY SHOULD
CONTINUE TO BE BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 152 PM EDT FRI JUL 11 2014
A BAND OF LIGHT SHOWERS MOVING THROUGH UPPER MICHIGAN THROUGH EARLY
AFTERNOON IS NOT EXPECTED TO BE HEAVY ENOUGH...PER RADAR TRENDS...TO
REDUCE CONDITIONS TO MVFR. THE NEXT SHOT OF SOME SHRA AND POSSIBLE
TSRA IS EXPECTED THIS EVENING AS A WEAK COLD FRONT APPROACHES FROM
MN. LOCATION AND COVERAGE OF ANY PCPN IS QUITE UNCERTAIN...SO ONLY A
VCNTY SHRA MENTION WAS INCLUDED FOR NOW. LIKE TODAY...CONDITIONS
SHOULD STAY MAINLY VFR INTO SATURDAY MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EDT FRI JUL 11 2014
SOUTH WINDS OF UP TO 20 KTS...POSSIBLY 25 KTS AT HIGHER PLATFORMS
ABOVE MARINE LAYER... EXPECTED INTO THIS EVENING WILL DIMINISH
OVERNIGHT WITH WINDS SHIFTING TO SW. AS SCT SHOWERS ASSOCIATED WITH A
WEAK COLD FRONT OR TROUGH MOVE THROUGH LAKE SUPERIOR...FOG WILL BE
POSSIBLE ACROSS THE ENTIRE LAKE WITH THE TROUGH PASSAGE. LIGHT WINDS
WILL CONTINUE THROUGH SUNDAY BEFORE ANOTHER TROUGH PASSES
SOUTHEASTWARD ACROSS LAKE SUPERIOR SUNDAY NIGHT. GUSTY NORTHWEST
WINDS TO 20 KNOTS EXPECTED BEHIND THIS TROUGH EARLY NEXT WEEK AS
HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1045 PM CDT SAT JUL 12 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 308 PM CDT SAT JUL 12 2014
RADAR IMAGERY CONTINUES TO SHOW RAIN WITH EMBEDDED THUNDERSTORMS
OVER THE AREA AS OF 330 PM. PCPN WAS FOCUSED OVER TWO AREAS... ONE
NEAR THE IOWA BORDER AND ANOTHER FROM EAST CENTRAL INTO WEST CENTRAL
MINNESOTA. THE FORMER AREA WAS BEING SUPPORTED BY A SHORTWAVE
EVIDENT IN WATER VAPOR IMAGERY OVER FAR SOUTHERN MINNESOTA AND THE
MAIN INSTABILITY GRADIENT/BAROCLINIC ZONE. HOWEVER... THE LATTER WAS
BEING AIDED BY THE SECONDARY FRONT/DEWPOINT GRADIENT DROPPING
SOUTHEAST THROUGH THE AREA AHEAD OF THE SHORTWAVE TROUGH PUSHING
EAST FROM THE DAKOTAS INTO MINNESOTA. MLCAPE VALUES OF 250-1000 J/KG
WERE APPARENT IN THE SPC MESOANALYSIS OVER THE EASTERN PORTION OF
THE AREA... WHERE EMBEDDED STORMS WITH HIGH RAINFALL RATES WERE
PRESENT. SOME PEA SIZED HAIL WAS OCCURRING WITH THE STRONGEST
STORMS... WHICH HAD SOME BETTER CORES ABV 25K FT AGL. THE HRRR HAS
HAD A DECENT HANDLE ON THINGS THROUGH THE DAY... SO GENERALLY
FOLLOWED ITS GUIDANCE TOGETHER WITH NEIGHBORHOOD PROBABILITIES FROM
THE HOPWRF. THAT BEING SAID... EXPECT THINGS TO SHIFT EAST/SOUTH
THROUGH EARLY EVENING... WITH MOST OF THE CWFA BECOMING PCPN FREE
BETWEEN 00Z AND 03Z. WE COULD SEE SOME SHRA SNEAK BACK INTO THE
NORTHWEST/NORTH CENTRAL PORTION OF THE AREA LATER THIS EVENING AND
OVERNIGHT BEHIND THE FRONTAL BOUNDARY AS THE MID-UPPER LEVEL PV LOBE
SWINGS THROUGH THAT AREA. COLD ADVECTION WILL ASSERT ITSELF OVER THE
AREA ON SUNDAY. SUBSIDENCE WITH THE COLD ADVECTION SHOULD BE
SUFFICIENT TO KEEP ANY SHRA FROM DEVELOPING ON SUNDAY GIVEN THAT THE
BETTER LOW-MID LEVEL LAPSE RATES WILL STILL BE UPSTREAM AND CLOSER
TO THE UPPER LOW AT THAT POINT. SO... EXPECT MAINLY JUST DIURNAL CU
WITH TEMPERATURES GETTING INTO THE LOWER TO MIDDLE 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 308 PM CDT SAT JUL 12 2014
THE UPPER LOW WILL BEGIN DIGGING SOUTH AGGRESSIVELY SUNDAY NIGHT
AND WILL REACH THE CENTRAL GREAT LAKES MONDAY. CLOUDS AND
SCATTERED TO NUMEROUS SHOWERS WILL ACCOMPANY THE LOW
MONDAY...GREATEST COVERAGE NEAR THE LOW OVER WESTERN WI. STEEP LOW
LEVEL LAPSE RATES IN THE STRONG CAA REGIME MAY RESULT IN SOME
ISOLATED THUNDER...BUT NOTHING THAT WILL BE TOO STRONG GIVEN THE
RELATIVELY SHALLOW INSTABILITY/MOIST LAYER - MORE LIKE AN ISOLATED
STRIKE OR TWO AT BEST.
THE BIGGER STORY MONDAY WILL BE THE MUCH COOLER THAN NORMAL
TEMPERATURES EXPECTED. 925 MB TEMPS OF ONLY ABOUT +10C AND 850 MB
TEMPS AT BEST A FEW DEGREES ABOVE 0C WILL ALLOW HIGHS TO ONLY
REACH THE LOW TO MID 60S...EVEN IF THE SUN CAN MAKE A BRIEF
APPEARANCE. RECORD LOW MAX TEMPS ARE 68 AT MSP...STC AND EAU AND
RECORD LOWS MONDAY NIGHT ARE MID TO UPPER 40S. THE RECORD LOWS MAY
BE A BIT OF A STRETCH...BUT THE COLD HIGHS SHOULD BE RELATIVELY
EASILY ATTAINABLE IF HIGHS ARE NOT REACHED AT 06Z MONDAY.
THE TROUGH WILL SLOWLY LIFT OUT FOR MID TO LATE WEEK...BUT THE
MOISTURE WILL EXIT AS EARLY AS MONDAY NIGHT. THEREFORE...EXPECTING
A MOSTLY CLEAR REST OF THE WEEK WITH SLOWLY MODERATING TEMPERATURES.
FOR MOST...THIS MAY BE CONSIDERED THE NICEST WEEK OF THE SUMMER
THUS FAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1045 PM CDT SAT JUL 12 2014
TWO ISSUES TO DEAL WITH OUT THE GATE WITH THE 06Z TAFS. THE FIRST
IS PATCHY FOG FORMING ACROSS SOUTHERN MN THROUGH WEST CENTRAL WI
WHERE WINDS HAVE BECOME QUITE LIGHT AHEAD OF AN APPROACHING COLD
FRONT ALONG WITH DEW POINTS HOLDING IN THE MIDDLE TO UPPER 60S.
THIS IS ON TOP OF THE RAIN THAT FELL TODAY. THIS AFFECTS
KRWF...KRNH AND KEAU. NOT TOO KEEN ON KMSP HAVING MVFR BR WITH A
BIGGER SPREAD BETWEEN THE TEMP AND DEW POINT (HEAT ISLAND). HAVE
INCLUDED MVFR CIGS AS WELL FOR KRNH AND KEAU FOR A FEW HOURS
BEFORE THE COLD FRONT MOVES THROUGH. THE AFOREMENTIONED FRONT WILL
PUSH THROUGH KAXN BY THE START OF THE PERIOD AND WORK IT WAYS TO A
POSITION SOUTH OF A KRWF TO KEAU LINE BY 12Z. WINDS WILL BRIEFLY
TURN DUE NORTH AND PERHAPS EVEN A LITTLE NORTHEAST BEHIND THE
FRONT BEFORE SETTLING BACK TO A NW DIRECTION. A FEW SHOWERS AND
ISOLATED THUNDERSTORMS ALONG THE FRONT CONTINUE TO WEAKEN...BUT A
FEW BOGEYS MAY MAKE IT INTO CENTRAL MN AND WEST CENTRAL WI DURING
THE EARLY MORNING HOURS. VCSH INCLUDED. VFR ON SUNDAY WITH
INCREASING NORTHWEST WINDS. SPEEDS 12-16 KNOTS FOR THE LATE
MORNING AND AFTERNOON ALONG WITH GUSTS UP TO 25 KNOTS.
KMSP...A COLD FRONT ACROSS NORTHERN MN WILL PASS THE AIRFIELD IN
THE 09Z-10Z TIME FRAME. A DRY PASSAGE FORECAST WITH BKN-OVC VFR
CLOUDS. SCT CLOUDS ON SUNDAY WITH BREEZY NORTHWEST WINDS
(16G23KTS) FOR THE AFTERNOON AND EARLY EVENING.
/OUTLOOK FOR KMSP/
MON...MVFR PSBL WITH CHC OF SHRA/TSRA. NW WINDS 15-30 KTS.
TUE...VFR. NW WINDS 10-15 KTS.
WED...VFR. NW WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...BORGHOFF
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
707 PM CDT SAT JUL 12 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 308 PM CDT SAT JUL 12 2014
RADAR IMAGERY CONTINUES TO SHOW RAIN WITH EMBEDDED THUNDERSTORMS
OVER THE AREA AS OF 330 PM. PCPN WAS FOCUSED OVER TWO AREAS... ONE
NEAR THE IOWA BORDER AND ANOTHER FROM EAST CENTRAL INTO WEST CENTRAL
MINNESOTA. THE FORMER AREA WAS BEING SUPPORTED BY A SHORTWAVE
EVIDENT IN WATER VAPOR IMAGERY OVER FAR SOUTHERN MINNESOTA AND THE
MAIN INSTABILITY GRADIENT/BAROCLINIC ZONE. HOWEVER... THE LATTER WAS
BEING AIDED BY THE SECONDARY FRONT/DEWPOINT GRADIENT DROPPING
SOUTHEAST THROUGH THE AREA AHEAD OF THE SHORTWAVE TROUGH PUSHING
EAST FROM THE DAKOTAS INTO MINNESOTA. MLCAPE VALUES OF 250-1000 J/KG
WERE APPARENT IN THE SPC MESOANALYSIS OVER THE EASTERN PORTION OF
THE AREA... WHERE EMBEDDED STORMS WITH HIGH RAINFALL RATES WERE
PRESENT. SOME PEA SIZED HAIL WAS OCCURRING WITH THE STRONGEST
STORMS... WHICH HAD SOME BETTER CORES ABV 25K FT AGL. THE HRRR HAS
HAD A DECENT HANDLE ON THINGS THROUGH THE DAY... SO GENERALLY
FOLLOWED ITS GUIDANCE TOGETHER WITH NEIGHBORHOOD PROBABILITIES FROM
THE HOPWRF. THAT BEING SAID... EXPECT THINGS TO SHIFT EAST/SOUTH
THROUGH EARLY EVENING... WITH MOST OF THE CWFA BECOMING PCPN FREE
BETWEEN 00Z AND 03Z. WE COULD SEE SOME SHRA SNEAK BACK INTO THE
NORTHWEST/NORTH CENTRAL PORTION OF THE AREA LATER THIS EVENING AND
OVERNIGHT BEHIND THE FRONTAL BOUNDARY AS THE MID-UPPER LEVEL PV LOBE
SWINGS THROUGH THAT AREA. COLD ADVECTION WILL ASSERT ITSELF OVER THE
AREA ON SUNDAY. SUBSIDENCE WITH THE COLD ADVECTION SHOULD BE
SUFFICIENT TO KEEP ANY SHRA FROM DEVELOPING ON SUNDAY GIVEN THAT THE
BETTER LOW-MID LEVEL LAPSE RATES WILL STILL BE UPSTREAM AND CLOSER
TO THE UPPER LOW AT THAT POINT. SO... EXPECT MAINLY JUST DIURNAL CU
WITH TEMPERATURES GETTING INTO THE LOWER TO MIDDLE 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 308 PM CDT SAT JUL 12 2014
THE UPPER LOW WILL BEGIN DIGGING SOUTH AGGRESSIVELY SUNDAY NIGHT
AND WILL REACH THE CENTRAL GREAT LAKES MONDAY. CLOUDS AND
SCATTERED TO NUMEROUS SHOWERS WILL ACCOMPANY THE LOW
MONDAY...GREATEST COVERAGE NEAR THE LOW OVER WESTERN WI. STEEP LOW
LEVEL LAPSE RATES IN THE STRONG CAA REGIME MAY RESULT IN SOME
ISOLATED THUNDER...BUT NOTHING THAT WILL BE TOO STRONG GIVEN THE
RELATIVELY SHALLOW INSTABILITY/MOIST LAYER - MORE LIKE AN ISOLATED
STRIKE OR TWO AT BEST.
THE BIGGER STORY MONDAY WILL BE THE MUCH COOLER THAN NORMAL
TEMPERATURES EXPECTED. 925 MB TEMPS OF ONLY ABOUT +10C AND 850 MB
TEMPS AT BEST A FEW DEGREES ABOVE 0C WILL ALLOW HIGHS TO ONLY
REACH THE LOW TO MID 60S...EVEN IF THE SUN CAN MAKE A BRIEF
APPEARANCE. RECORD LOW MAX TEMPS ARE 68 AT MSP...STC AND EAU AND
RECORD LOWS MONDAY NIGHT ARE MID TO UPPER 40S. THE RECORD LOWS MAY
BE A BIT OF A STRETCH...BUT THE COLD HIGHS SHOULD BE RELATIVELY
EASILY ATTAINABLE IF HIGHS ARE NOT REACHED AT 06Z MONDAY.
THE TROUGH WILL SLOWLY LIFT OUT FOR MID TO LATE WEEK...BUT THE
MOISTURE WILL EXIT AS EARLY AS MONDAY NIGHT. THEREFORE...EXPECTING
A MOSTLY CLEAR REST OF THE WEEK WITH SLOWLY MODERATING TEMPERATURES.
FOR MOST...THIS MAY BE CONSIDERED THE NICEST WEEK OF THE SUMMER
THUS FAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 707 PM CDT SAT JUL 12 2014
RAIN HAS PUSHED EAST OF ALL OF THE TAF SITES EARLY THIS EVENING
WITH THE EXCEPTION OF KEAU. EVEN THERE...THE RAIN WILL END WITH IN
AN HOUR. THE BACK EDGE OF THE VFR CLOUD SHIELD WAS WORKING INTO
WEST CENTRAL WI WITH GENERALLY CLR-SCT CONDITIONS ACROSS CENTRAL
AND SOUTHERN MN. THERE ARE TWO CONCERNS OVERNIGHT. THE FIRST IS
THE COLD FRONT AND BAND OF SHRA/TSRA MOVING INTO NW MN ATTM. THE
ACTIVITY IS MOVING SE NEAR 45 KNOTS. SHORT TERM CONVECTIVE MODELS
HAVE A GOOD HANDLE ON THE LINE WITH SIGNIFICANT WEAKENING AFTER
SUNSET. THIS RESULTS IN ONLY A FEW SHOWERS POSSIBLY BRUSHING
KAXN...KSTC AND KRNH DURING THE LATE EVENING HOURS. A VCSH AS
USED. THE OTHER CONCERN OVERNIGHT IS FOG. THE SITE THAT HAS THE
BEST CHANCE IS KEAU WHERE CLEARING WILL OCCUR THIS EVENING AFTER
AN AFTERNOON OF RAIN. KEPT MVFR BR IN THE OVERNIGHT FORECAST. THE
OTHER SITES LOOKS TO HAVE TOO MUCH WIND PLUS THE DEW POINTS WILL
BE LOWERING AS THE NIGHT PROGRESSES. SUNDAY WILL BE A REFRESHING
DAY WITH INCREASING NORTHWEST WINDS OF 12-16 KNOTS BY AFTERNOON
ALONG WITH GUSTS FROM 20 TO 25 KNOTS. FEW-SCT SC DURING THE DAY
ON SUNDAY.
KMSP...VFR CONDITIONS FORECAST THROUGH THE PERIOD. LIGHT WNW WINDS
TONIGHT THEN INCREASING TO AROUND 15 KNOTS FOR SUNDAY AFTERNOON/EARLY
EVENING ALONG WITH GUSTS TO 25 KNOTS.
/OUTLOOK FOR KMSP/
MON...MVFR PSBL WITH CHC OF SHRA/TSRA. NW WINDS 15-30 KTS.
TUE...VFR. NW WINDS 10-15 KTS.
WED...VFR. NW WINDS 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...BORGHOFF
AVIATION...RAH
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
241 PM CDT FRI JUL 11 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CDT FRI JUL 11 2014
LATEST VISIBLE IMAGERY SHOWS AN AREA OF EXTENSIVE LOW CLOUDS NEAR
AND DOWNWIND OF THE SURFACE FRONT/TROUGH AXIS WITH A MORE HEALTHY CU
FIELD TRYING TO DEVELOP NEAR ITS BACK EDGE AND POINTS UPSTREAM.
CLOUDS HAVE MANAGED TO BREAK UP SOUTHEAST OF THERE... INCLUDING THE
SOUTHERN AND EASTERN PORTION OF THE TWIN CITIES... IN THE WAKE OF
THIS MORNING/S CONVECTION. INSTABILITY HAS INCREASE ACROSS THE
WESTERN CWFA... WITH MLCAPE VALUES AOA 500 J/KG WITH NEAR 1500 J/KG
OVER THE FAR WEST. A SUBTLE SHORTWAVE FEATURE CAN BE SEEN IN THE
WATER VAPOR IMAGERY MOVING EAST THROUGH THE ZONAL FLOW ACROSS NORTH
DAKOTA AT THE CURRENT TIME. THIS COULD WORK WITH THE WEAK
CONVERGENCE PRESENT NEAR THE SURFACE TROUGH TO GENERATE SOME
ISOLATED/SCATTERED SHRA/TSRA LATE THIS AFTERNOON INTO EARLY THIS
EVENING. THE NAM IS NOT PARTICULARLY OPTIMISTIC ABOUT ANYTHING OVER
OUR AREA... WHILE THE GFS AND ECMWF MANAGE TO SHOW SOME LIGHT PCPN.
THE CAMS ARE A MIXED BAG... WITH MANY SUCH AS THE HRRR AND A COUPLE
HOPWRF MEMBERS KEEPING THINGS GENERALLY DRY... WHILE A COUPLE HOPWRF
MEMBERS AND THE HIRES WINDOW RUNS MANAGE TO SHOW A FEW CONVECTIVE
CELLS. ALLOWED FOR CHANCE POPS OVER THE AREA FROM LATE AFTERNOON
INTO EVENING TO ACCOUNT FOR THE POSSIBILITY OF A FEW SHRA/TSRA
GETTING GOING. OTHERWISE... THE MAIN LARGE SCALE SUPPORT FOR PCPN
THROUGH TOMORROW LOOKS TO SHIFT TO THE SOUTHERN PORTION OF THE AREA
AND EVEN MORE SO PERHAPS INTO IOWA WHERE THE BAROCLINIC ZONE LOOKS
TO STALL OUT AND THE BEST FRONTOGENESIS AND THETA-E ADVECTION IS
EXPECTED. ALLOWED FOR SOME OF THIS TO SPREAD NORTH DURING THE DAY ON
SATURDAY AS THE FLOW STARTS TO AMPLIFY AND WE SEE A SOMEWHAT
HEALTHIER SHORTWAVE ARRIVE FROM THE WEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CDT FRI JUL 11 2014
THE LONG TERM PORTION OF THE FORECAST WILL BE GREATLY INFLUENCED BY
A HIGHLY AMPLIFIED LARGE SCALE PATTERN...WITH A DEEP TROUGH
DOMINATING EASTERN CANADA/CONUS...AND RIDGING PREVAILING OVER THE
WEST. SAID PATTERN WILL TRANSLATE TO BELOW NORMAL TEMPERATURES FOR
THE EASTERN TWO-THIRDS OF THE CONUS THROUGH MUCH OF NEXT WEEK.
SATURDAY EVENING SHOULD BRING THE EXIT OF ANY LINGERING SHOWERS
AND THUNDERSTORMS...WITH SKIES CLEARING OUT BY SUNDAY.
THUNDERSTORMS LOOK A BIT LESS LIKELY FOR SUNDAY PER THE 12Z MODEL
RUNS...WITH THE ONLY SLIM POTENTIAL APPEARING TO BE OVER FAR
SOUTHERN MN WHERE DIURNALLY-INDUCED ACTIVITY COULD DEVELOP IN THE
WANING BAROCLINIC ZONE.
MONDAY BRINGS THE ARRIVAL OF THE UPPER LOW OVERHEAD...MADE EVIDENT
BY SCATTERED SHOWERS AND TEMPERATURES NEARING 20 DEGREES BELOW
NORMAL. HIGHS IN THE LOW/MID 60S WILL COMBINE WITH BREEZY NORTHWEST
WINDS TO MAKE FOR A CHILLY DAY.
TUESDAY THE TROUGH CENTER WILL HAVE SHIFTED EAST OF THE AREA...SO
SHOWER CHANCES WILL BE MAINLY CONFINED TO WEST CENTRAL WI
COUNTIES. HIGHS WILL MODERATE A TAD...BUT WILL LIKELY STILL TOP
OUT IN THE MID/UPPER 60S.
WEDNESDAY AND THURSDAY THE LOW LIFTS INTO QUEBEC AND HEIGHTS RISE
A BIT. THIS WILL MEAN GRADUALLY MODERATING TEMPERATURES AND DRY
WEATHER...WITH HIGHS IN THE LOW/MID 70S ON WEDNESDAY...AND
MID/UPPER 70S FOR THURSDAY.
BY FRIDAY THE FLOW TRANSITIONS TO NEARLY ZONAL ACROSS THE
CONUS...AS WEAK MID LEVEL TROUGHING OVER SOUTHERN
SASKATCHEWAN/MANITOBA INDUCES HIGH PLAINS SURFACE CYCLOGENESIS.
SOUTHERLY FLOW AHEAD OF THIS FEATURE WILL AID IN FURTHER TEMPERATURE
MODERATION ON FRIDAY...WITH HIGHS IN THE UPPER 70S AND LOWER 80S.
STILL LOOKS TO BE DRY ON FRIDAY...ALTHOUGH THE AFOREMENTIONED
TROUGH SHOULD FACILITATE SHOWER AND THUNDERSTORM CHANCES AT SOME
POINT NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 156 PM CDT FRI JUL 11 2014
WILL HAVE VARIOUS ISSUES THROUGH THE PERIOD. LINGERING CEILINGS
ACROSS THE AREA SHOULD GENERALLY IMPROVE THROUGH THE AFTERNOON...
WHILE REMAINING MOST FOCUS NEAR AND DOWNSTREAM OF THE FRONT/TROUGH
WHERE SOME MVFR REMAINS. THERE IS A CHANCE FOR A FEW SHRA/TSRA
FROM 21Z THROUGH 03Z AT MOST SITES... BUT COVERAGE IS EXPECTED TO
BE LOW IF THINGS OCCUR... SO LEFT ANY MENTION OUT OF THE FORECAST
FOR NOW. LATER TONIGHT WE COULD SEE SOME FOG AT MOST SITES... AND
IT COULD BE WORSE THAN FORECAST IF WINDS DIE AND WE HAVE LESS IN
THE WAY OF MID-HIGH CLOUDS THAN EXPECTED. HINTED AT SOME LOWER
VISIBILITIES... BUT DID NOT GO AS LOW AS WHAT IS POSSIBLE GIVEN
THE UNCERTAINTY. SHRA/TSRA WILL BE POSSIBLE AGAIN ON SATURDAY...
BUT THERE REMAINS UNCERTAINTY ON HOW FAR NORTH ACROSS THE AREA IT
WILL EXTEND... SO PLAYED THINGS OPTIMISTIC FOR NOW AND DID NOT
INCLUDE TOO MUCH OF A MENTION.
KMSP...CONFIDENCE IN FORECAST SPECIFICS IS LOW GIVEN SLOWLY MOVING
FRONT/TROUGH AND LINGERING BAROCLINIC ZONE WITHOUT ANY SIGNIFICANT
FORCING FEATURE OVER THE AREA. FOG ISSUES AND PERHAPS SOME STRATUS
COULD BE WORSE THAN INDICATED LATER TONIGHT... AND PCPN COULD BE
MORE WIDESPREAD INTO THE AREA LATER TONIGHT.
/OUTLOOK FOR KMSP/
SATURDAY NIGHT...VFR. WEST WIND LESS THAN 10 KT BECOMING NORTH.
SUNDAY...VFR. NORTHWEST WIND 5 TO 15 KT.
SUNDAY NIGHT. MVFR POSSIBLE WITH A CHANCE OF SHRA/TSRA. NORTHWEST
WIND 5 TO 15 KT. MONDAY...MVFR POSSIBLE WITH A CHANCE OF
SHRA/TSRA. NORTHWEST WIND 10 TO 20 KT. MONDAY NIGHT...MVFR
POSSIBLE. NORTHWEST WIND 5 TO 10 KT. TUESDAY...VFR. NORTHWEST WIND
LESS THAN 10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...TRH
LONG TERM...LS
AVIATION...TRH
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1015 AM CDT FRI JUL 11 2014
.UPDATE...
MORNING SURFACE ANALYSIS INDICATES FRONTAL BOUNDARY STALLED IN THE
AREA WITH DRIER AIR MOVING INTO NRN MS PER WATER VAPOR IMAGERY.
PWATS HAVE DECREASED NEAR 1.0 INCHES IN 12Z BMX SOUNDING WHILE 12Z
KJAN AND OTHER REGIONAL SOUNDINGS ALONG/W ARE CLOSER TO 1.6-2.0
INCHES. RUC/GFS/EURO INDICATES SOME OF THIS DRIER AIR WILL FILTER
INTO THE E/NE LATER TODAY. ANOTHER S/WV DISTURBANCE WILL MOVE INTO
THE WRN AREAS TODAY AS THE H5 UPPER RIDGE OVER THE CENTRAL PLAINS
MOVES TO THE SE TODAY. FLOW ALOFT HAS BECOME MORE FROM THE NW/N AND
WILL CONTINUE TO BECOME MORE FROM THE N THROUGH THE AFTERNOON. AS
SOME OF THE DRIER AIR FILTERS IN THE E/NE AND THE S/WV MOVES
IN...EXPECT THE BEST POPS TO REMAIN ALONG/W OF THE I-55 CORRIDOR
WITH DECREASING POPS IN THE E/NE. ADJUSTED POPS TO REFLECT HIGHEST
IN THE W MAINLY AFTER 17Z. LOCAL WET MICROBURST CHECKLIST REVEALS A
RISK DUE TO GOOD VERTICAL TOTALS APPROACHING 27-28 DEG C AND SBCAPES
AROUND 3000 J/KG. EXPECTING THE ACTIVITY TO REMAIN ISOLATED TO
POSSIBLY SCATTERED IN THE W BUT NOT WIDESPREAD ENOUGH TO MENTION IN
THE HWO. A STRONG TO SEVERE STORM CAN NOT BE RULED OUT BUT WOULD
REMAIN ISOLATED AT MOST. LOCALLY HEAVY RAIN IS ALSO POSSIBLE DUE TO
DEEP MOISTURE AND SLOW STORM MOVEMENT. HIGHS TODAY LOOK ON TRACK IN
THE LOWER 90S DUE TO STORMS/CLOUDS IN THE REGION. A HOT AND HUMID
AFTERNOON IS IN STORE WITH HEAT INDICES IN THE UPPER 90S TO NEAR 100
DEGREES IN W/SW. ADJUSTED HOURLY TEMPS/DEWPOINTS/SKY GRIDS TO CURRENT
TRENDS. REST OF THE FORECAST IS ON TRACK. /DC/
&&
.AVIATION...CONVECTION ALREADY DEVELOPING THIS MORNING OVER NW MS
WILL CONTINUE TO DROP S AND INCREASE IN COVERAGE THROUGH THE
AFTERNOON AS ADVERTISED BY THE HRRR MODEL. WILL CONTINUE VICINITY TS
IN W MS TAF SITES WHILE EASTERN AREAS WILL SEE SOMEWHAT LESS
COVERAGE. CONVECTION WILL WIND DOWN DURING THE EARLY EVENING WITH
MVFR VISIBILITIES IN MIST DEVELOPING AFTER 06Z IN THOSE AREAS THAT
GET RAINFALL TODAY. VFR CONDITIONS WILL RETURN BY 14Z DUE TO
INCREASED MIXING. /26/
&&
.PREV DISCUSSION... /ISSUED 355 AM CDT FRI JUL 11 2014/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...A DISTURBANCE THAT
MOVED INTO MY NORTHWEST ZONES YESTERDAY EVENING AND HAS BEEN
RESPONSIBLE FOR SHOWERS AND A FEW STORMS LINGERING OVER THE CWA
OVERNIGHT...CONTINUES ITS TREK TO THE SOUTHEAST OVER THE AREA THIS
MORNING. MEANWHILE LOOKING UPSTREAM...IT APPEARS THAT ANOTHER
DISTURBANCE IS POISED TO MOVE INTO AND THROUGH THE FORECAST AREA
FROM NORTHWEST TO SOUTHEAST YET AGAIN THROUGH THE COURSE OF TODAY.
THIS...A VERY MOIST AIRMASS AS WE REMAIN SOUTH OF A FRONT MEANDERING
ABOUT OVER NORTH MISSISSIPPI (I.E. PRECIPITABLE H2O VALUES AROUND 2
INCHES)...AND DAYTIME HEATING...WILL AGAIN LEAD TO SHOWERS AND
STORMS DEVELOPING PREDOMINATELY DURING THE AFTERNOON HOURS TODAY.
BECAUSE OF THIS MOISTURE RICH AIRMASS...LOCALLY HEAVY RAIN AGAIN
LOOKS TO BE THE BIGGEST CONCERN WITH CONVECTION TODAY...ALTHOUGH
SOME GUSTS AROUND 30 MPH CAN`T BE RULED OUT WITH THE MOST INTENSE
CONVECTION.
BEST RAIN CHANCES TODAY AGAIN APPEAR TO BE OVER AREAS GENERALLY
ALONG AND WEST OF THE HIGHWAY 49 CORRIDOR. WITH SOME SLIGHTLY DRIER
AIR FILTERING IN...PLUS THE OVERALL MID/UPPER FLOW ACROSS THE
AREA...RAIN CHANCES LOOK TO BE LESS OVER EAST CENTRAL AND NORTHEAST
MISSISSIPPI. CONVECTION WILL BEGIN TO WANE AFTER SUNSET THIS
EVENING.
FOR SATURDAY AND SATURDAY NIGHT...A DEEPER PUSH OF SLIGHTLY DRY AIR
INTO THE REGION IS CURRENTLY FORECAST. IN ADDITION TO THIS...AN
INCREASE IN MID/UPPER LEVEL RIDGING WILL ALLOW FOR LESS RAIN CHANCES
OVER THE CWA AS THEY BECOME CONFINED TO MAINLY LOCALES SOUTH OF THE
INTERSTATE 20 CORRIDOR. ONCE AGAIN...CONVECTION WILL BE CONFINED TO
MAINLY THE AFTERNOON HOURS...WITH A GRADUAL DISSIPATION IN ACTIVITY
EXPECTED AFTER SUNSET.
AS FAR AS TEMPERATURES ARE CONCERNED...I STAYED PRETTY CLOSE TO
GUIDANCE IN TERMS OF LOW TEMPERATURES. HOWEVER...BECAUSE OF MOIST
GROUND CONDITIONS AND CLOUDS...ESPECIALLY FOR THIS AFTERNOON...I DID
ADJUST HIGHS TEMPERATURES DOWN A BIT. /19/
LONG TERM...SUNDAY THROUGH FRIDAY...BROAD RIDGING WILL BE IN PLACE
OVER THE REGION AT THE START OF THE LONG TERM. THIS WILL BRING
SLIGHTLY ABOVE NORMAL TEMPERATURES TO THE REGION. GUIDANCE WAS A
LITTLE ROBUST IN HIGHS FOR SUNDAY AND FELT THAT GIVEN ENOUGH GROUND
MOISTURE PRESENT STILL FROM RECENT RAINFALL AND POTENTIAL FOR ADDITIONAL
CONVECTION...GOING SLIGHTLY CLOSER TO THE NAM/ECMWF WOULD BE A
BETTER FIT. WITH HIGHS IN THE 90S...AND PLENTY OF MOISTURE IN
PLACE(PW VALUES AROUND 1.7-1.9 INCHES)...THERE SHOULD BE SOME
AFTERNOON AND EARLY EVENING CONVECTION. ANOTHER CONCERN FOR SUNDAY
WILL BE FROM HEAT STRESS. MUGGY CONDITIONS WILL OCCUR AND THIS COULD
BRING SOME HEAT INDICES...ESPECIALLY IN THE WESTERN PORTIONS OF THE
CWA...TO AROUND 101-103 DEGREES. VALUES SHOULD STILL REMAIN BELOW
CRITERIA FOR ANY ADVISORIES BUT THIS WILL NEED TO BE MONITORED FOR
AT LEAST MAYBE SOME MENTION OF LIMITED POTENTIAL IN THE HWO.
THE MAIN STORY OF THE EXTENDED FORECAST IS IN THE PATTERN CHANGE
THAT WILL BE UNDERWAY AT THE START TO MIDDLE OF THE WORK WEEK. A
LARGE UPPER TROUGH WILL TAKE SHAPE AND SET UP OVER THE GREAT LAKES
REGION. THIS WILL SEND AN UNSEASONABLY STRONG COLD FRONT OUR WAY FOR
TUESDAY INTO WEDNESDAY. SHOWERS AND THUNDERSTORMS WILL OCCUR ALONG
AND AHEAD OF THE FRONT ON TUESDAY BUT AT THIS TIME PARAMETERS DONT
LOOK VERY IMPRESSIVE FOR SEVERE STORMS. AS THE FRONT MOVES
THROUGH...CHANCES FOR RAIN WILL CONTINUE ESPECIALLY IN THE SOUTH
WHERE DRIER AIR WILL BE SLOWER TO MOVE IN. TEMPERATURES THROUGH MID
WEEK WILL BE FAIRLY PLEASANT IN THE 80S FOR MOST ALL LOCATIONS AND
EVEN LOWER 80S IN THE NORTH. OVERNIGHT LOWS WILL BE IN THE 60S.
AS THE UPPER TROUGH REMAINS EXTENDED ACROSS THE SOUTH...SEVERAL WEAK
DISTURBANCES IN THE FLOW WILL MOVE ACROSS OUR AREA THROUGH THE END
OF THE WEEK. THESE WILL COMBINE WITH MOISTURE CHARACTERIZED BY ~1.7
INCH FORECAST PW VALUES...AND KEEP AT LEAST SOME CHANCE FOR RAIN IN
THE FORECAST. TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH THE END
OF THE WEEK. /28/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 93 70 94 70 / 29 11 5 9
MERIDIAN 92 69 94 69 / 13 9 7 7
VICKSBURG 93 68 93 69 / 37 12 7 10
HATTIESBURG 93 70 95 72 / 24 10 18 13
NATCHEZ 91 70 93 71 / 36 15 22 14
GREENVILLE 92 71 94 71 / 36 10 3 8
GREENWOOD 92 69 93 69 / 26 10 3 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DC/26/19/28
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1100 PM MDT Thu Jul 10 2014
.DISCUSSION...
Update forthcoming. Lingering monsoonal moisture, along with
atmospheric instability along the southwest Montana/Idaho border, is
allowing isolated thunderstorms to continue. However, the moisture
source is beginning to decrease and convective activity should
further decrease with the loss of daytime heating. Have scaled back
the POP field through midnight, keeping POPs over extreme south and
southeast Montana. Have scaled back POPs even further after
midnight. In the north, circulation around an upper low centered
over western Saskatchewan is pushing moisture into an unstable
airmass and across the Canadian prairie. This moisture has combined
with a cold front moving south and the result is the development of
isolated thunderstorms. Satellite imagery indicates a strong
thunderstorm moving east-southeast across southern Alberta at this
time. RUC model data and HRRR analysis want to bring the core of
this storm south of the international border after 05z, affecting
areas along the Hi-Line. Have gone with low POPs across the northern
portion of the county warning area for this reason, bringing the
threat as far south as Lewistown and as far west as Great Falls per
the RUC. Temperatures look reasonable.
&&
.AVIATION...
UPDATED 0500Z.
VFR conditions will generally continue across the area through at
least Friday evening. Moisture wrapping around a low pressure system
in central Canada combined with a weak cold front moving south
through north central/central Montana area has caused scattered
thunderstorms to develop across north central Montana (including
KCTB KHVR). These storms will likely weaken as they spread south
into central (KGTF KLWT) Montana through, so have only mentioned
VCSH in those TAFs at this time. Clouds/showers/storms will decrease
after 15Z as the system exits the area. However, monsoonal moisture
will move back into southwest Montana (including KBZN) after 18Z,
bringing a chance of thunderstorms there.
Coulston
&&
.PREV DISCUSSION...Issued 242 PM MDT Thu Jul 10 2014
Thursday through Saturday...Hot and dry conditions will continue
as the slowly moving large scale ridge continues to be dominant
force in the weather pattern over much of the Western United States.
Will continue to remain in a transition period on the edge of the
ridge through at least the next 24 hours. This will allow for
showers to develop as moisture allows. The best chance will be
with afternoon heating over the Mountains of Southwest Montana and
across the highline Thursday Evening as a weak disturbance moves
across the northern counties. By Friday a slight increase in
available moisture will allow for more showers and thunderstorms
to develop with afternoon heating...however showers will likely be
limited to scattered at best coverage. Another round of showers
will again occur on Saturday during peak heating mainly over the
higher terrain. Suk
Saturday night through Thursday...An upper level ridge high
pressure will be over the region this weekend...then the upper level
ridge will shift westward on Monday...as a fairly strong upper level
low pressure over the Great Lakes area rotates a bit cooler air into
the region. As the upper level low over the Great Lakes begins to
move eastward on Tuesday...the upper level ridge will also start to
shift back eastward for Tuesday afternoon through Thursday. Thus
fairly warm temperatures are expected for Sunday...then seasonable
temperatures for Monday and Tuesday...with a return to slightly
above normal temperatures for Wednesday and Thursday. In terms of
precipitation...confidence is quite low on any one given day...thus
most days the chances for thunderstorms are fairly isolated. The
best time frame for any storms to occur will be late afternoon
through around Midnight...but again the thunderstorm activity should
be fairly isolated and not have significant impacts on any one given
day. Brusda
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 54 78 54 86 / 20 10 10 10
CTB 51 75 50 84 / 20 10 10 10
HLN 58 84 58 88 / 10 10 20 20
BZN 53 83 54 83 / 10 30 20 40
WEY 44 79 44 76 / 30 50 40 50
DLN 54 84 55 83 / 10 20 20 40
HVR 56 80 53 88 / 20 20 10 10
LWT 54 78 53 84 / 20 20 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
www.facebook.com/US.NationalWeatherService.GreatFalls.gov
AREA FORECAST DISCUSSION...UPDATED
NWS OMAHA/VALLEY NE
1055 PM CDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 1055 PM CDT SAT JUL 12 2014
SURFACE FRONT HAD PUSHED SOUTH OF THE FORECAST AREA EARLIER...BUT TSTMS
FINALLY DID DEVELOP MID TO LATE EVENING ALONG ELEVATED PORTION OF
THE FRONT NEAR THE 850 MB LEVEL. HRRR MODEL HAD BEEN DOING A FAIRLY
DECENT JOB HANDLING THAT. STORMS SHOULD PUSH SOUTHEAST OUT OF THE
AREA LATER TONIGHT. ADDED SOME MENTION OF FOG NRN ZONES LATER TONIGHT.
PATCH OF MID CLOUDS DROPPING SWD FROM SOUTH DAKOTA COULD BRING A BIT
OF LIGHT PCPN TO PARTS OF NORTHEAST NEBRASKA TOWARD SUNRISE.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 247 PM CDT SAT JUL 12 2014
FORECAST CONCERNS IN THE SHORT TERM WILL BE THUNDERSTORM RE-
DEVELOPMENT AND POTENTIAL FOR LOCALLY HEAVY RAIN...SEVERE WEATHER.
THIS MORNING/S OAX SOUNDING HAD 1.71 IN PWAT AND A WARM CLOUD LAYER
OF OVER 10K FT. CLOSED H5 LOW PRESSURE WAS CENTERED OVER MANITOBA
AND EXTENDED INTO THE NORTHERN CONUS WITH THE STRONG SHORTWAVE
OVER WISCONSIN/SOUTHERN MINNESOTA. H7 MOISTURE OF 6DEG C WAS POOLED
OVER NORTHERN NEBRASKA...BUT WERE 2 TO 3 DEG C LOWER THAN
FORECAST BY THE NAM FRIDAY. WARM H7 TEMPERATURES +10C COVERED MUCH
OF SCENTRAL AND SOUTHERN NEBRASKA. H85 DEWPOINTS WERE ALSO POOLED
IN NORTHERN NEBRASKA WITH 14-16DEG C.
AT MIDDAY...THE BULK OF THE CONVECTION WAS CLOSER TO THE COLD FRONT
OVER SOUTHERN MINNESOTA...ANOTHER BOUNDARY WAS NEAR I80.
IN BETWEEN...IT WAS CLOUDY WITH AREAS OF SPRINKLES/SHOWERS. THIS
AFTERNOON/EVENING...H5 SHORTWAVE TROF ENERGY WILL SWING THROUGH
AND STRENGTHEN FROM IOWA INTO SOUTHERN NEBRASKA...THEN SHIFT
SOUTHWARD OUT OF THE AREA AFTER 09Z. AT 20Z...THE SURFACE FRONT
HAD PUSHED THROUGH MOST OF THE METRO AREA AND WAS NEAR LNK. CAN
SEE THE FRONT ON THE WSR-88D WITH NOT MUCH IN THE WAY OF ECHOES.
SHOULD SEE AN INCREASE IN THE COVERAGE OF STORMS THIS EVENING
WITH THE HEATING AND CONVERGENCE ALONG THE FRONT AND INCREASED
UPPER LEVEL SUPPORT. THE HRRR/RAP DO HAVE SOME ISO TO SCT
CONVECTION...THEN INCREASE COVERAGE ESPECIALLY IN THE 03Z-06Z TIME
PERIOD SOUTH OF THE METRO AREAS IN SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. HAVE ONLY ISO/SCT COVERAGE IN THE FORECAST THROUGH
03Z...THEN INCREASE TO LIKELY COVERAGE IN SOUTHEAST NEB AND
SOUTHWEST IOWA. THE LOW LEVEL JET SHOULD FOCUS MORE TO OUR
EAST...BUT MAY MENTION LOCALLY HEAVY RAIN FOR A FEW HOURS IN
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
SEVERE STORMS CANNOT BE RULED OUT WITH MODERATE INSTABILITY AND
SUFFICIENT SHEAR. SEEMS LIKE HEAVY RAIN WOULD BE MORE OF A
CONCERN DUE TO THE PWATS AVAILABLE AND HIGH EFFICIENCY. H85
CONVERGENCE APPEARS WEAKER IN OUR AREA AND STRONGER FARTHER EAST
INTO IOWA...SO THIS MAY TEMPER SEVERE POTENTIAL. THE STORM
PREDICTION CENTER DOES HAVE OUR AREA IN THE SLIGHT RISK FOR
SEVERE STORMS. THE WPC EXCESSIVE RAINFALL FORECASTS DO MENTION
SOUTHEAST NEBRASKA AND FAR SOUTHWEST IOWA THROUGH
TONIGHT...HOWEVER AFTERNOON UPDATE SHRUNK THE AREA FOR THE
EXCESSIVE RAINFALL THOUGH AND NOW IS JUST CLIPPING OUR AREA.
THE MOISTURE DOES NOT CLEAR OUT CLEANLY AND THERE IS SOME MID
LEVEL WARM AIR ADVECTION WITH CYCLONIC FLOW AROUND THE STORM
SYSTEM TO THE NORTHEAST THROUGH MONDAY. ISOLATED SHOWERS/TSTORMS
WILL BE POSSIBLE SUNDAY THROUGH MONDAY MORNING.
SURFACE HIGH PRESSURE BUILDS IN FOR MONDAY NIGHT AND TUESDAY WITH
NEAR RECORD LOWS MONDAY MORNING AND HIGHS IN THE 70S TUESDAY ABOUT
15 DEGREES BELOW NORMAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 247 PM CDT SAT JUL 12 2014
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN TUESDAY
THROUGH SATURDAY. LOOK FOR BELOW NORMAL HIGHS IN THE 70S.
WEDNESDAY AND THURSDAY...THEN HIGHS IN THE 80S FRIDAY AND
SATURDAY. WILL KEEP MAINLY DRY AND MAY NEED TO ADD POPS FOR
SATURDAY WITH A FRONT MOVING INTO THE AREA.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 620 PM CDT SAT JUL 12 2014
IT APPEARS THAT VFR CONDITIONS WILL PREVAIL MOST OF THE PERIOD...
WITH BEST TSTM CHANCES SOUTH OF THE TAF SITES. WILL AMEND IF NEEDED.
SOME MVFR VSBYS ARE POSSIBLE TOWARD SUNRISE.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
326 PM CDT FRI JUL 11 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 326 PM CDT FRI JUL 11 2014
A WARM FRONT EXTENDING FROM NEAR IMPERIAL IN SOUTHWEST NEBRASKA TO
OMAHA IN EASTERN NEBRASKA...WILL REMAIN NEARLY STATIONARY THROUGH
TONIGHT. A SOUTHERLY LOW LEVEL JET WILL DEVELOP ACROSS WESTERN
KANSAS THIS EVENING. THE NOSE OF THE JET WILL BE DIRECTED AT
SOUTHWEST NEBRASKA THROUGH THE EVENING HOURS...AND THEN VEER
SOUTHWEST TOWARD SOUTH CENTRAL NEBRASKA AFTER MIDNIGHT.
A COUPLE OF DIFFERENT SCENARIOS ARE POSSIBLE REGARDING CONVECTIVE
CHANCES LATE THIS AFTERNOON AND EVENING. FIRST...THUNDERSTORMS
CURRENTLY DEVELOPING NEAR THE LARAMIE RANGE ACROSS SOUTHEAST WYOMING
/AIDED BY A FAIRLY SIGNIFICANT SHORTWAVE ALOFT MOVING EASTWARD
TOWARD THAT AREA/ SHOULD PROPAGATE EAST INTO WESTERN NEBRASKA THIS
EVENING. DEEP MOISTURE AND UNSTABLE CONDITIONS RESIDE ACROSS MUCH OF
NEBRASKA TO THE NORTH OF THE AFOREMENTIONED WARM FRONT. LOW LEVEL
EASTERLY SURFACE WINDS NORTH OF FRONT WILL AID STORM-RELATIVE
INFLOW...AND THE DEVELOPING SOUTHERLY LOW LEVEL JET SHOULD FURTHER
SUPPORT INFLOW AS WELL AS CONTINUED MOISTURE ADVECTION. DUE TO THE
SEEMINGLY FAVORABLE CONDITIONS...THESE STORMS WILL LIKELY FORM INTO
A CLUSTER AND POSSIBLY AN MCS AS THEY MOVE EAST TOWARD CENTRAL/NORTH
CENTRAL NEBRASKA MID EVENING ONWARD. THE SECOND AND LESS LIKELY
SCENARIO WOULD BE FOR A FEW SURFACE BASED STORMS TO DEVELOP ACROSS
FAR SOUTHWEST NEBRASKA NEAR THE WARM FRONT LATE THIS AFTERNOON AND
EVENING. THESE WOULD LIKELY BE HIGH BASED AND ISOLATED. THE LATEST
RUN OF THE HRRR MODEL SUPPORTS THE FIRST SCENARIO...AND THE FORECAST
WILL BE TAILORED IN THAT DIRECTION.
A SHORTWAVE DISTURBANCE WILL BE CROSSING THE AREA SATURDAY
MORNING...WITH AT LEAST SCATTERED ELEVATED SHOWERS AND THUNDERSTORMS
EXPECTED TO BE ONGOING THROUGH THE MORNING HOURS. A WEAK COLD FRONT
WILL DROP SOUTH THROUGH THE AREA SATURDAY AFTERNOON. THIS FRONT WILL
MERGE WITH THE WARM FRONT ACROSS SOUTHERN NEBRASKA OR NORTHERN
KANSAS...WHERE SURFACE BASED CONVECTION IS POSSIBLE LATE IN THE
AFTERNOON. ACROSS OUR AREA...MOIST EAST/NORTHEAST UPSLOPE LOW LEVEL
FLOW WILL CONTINUE...AND THUNDERSTORMS SHOULD DEVELOP EASTWARD OFF
THE HIGHER TERRAIN INTO WESTERN NEBRASKA LATE SATURDAY AFTERNOON AND
EVENING. ACTIVITY SHOULD REMAIN SCATTERED AS FORCING IS EXPECTED TO
BE WEAK AS SHORTWAVE PUSHES EAST OF THE AREA. WILL LIMIT POPS TO 30
PERCENT FOR MOST LOCATIONS DURING THE AFTERNOON.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 326 PM CDT FRI JUL 11 2014
THE MAIN POINTS OF THE LONG TERM FORECAST INCLUDE COOLER
TEMPERATURES AND A DECREASE IN CHANCES OF SHOWERS/THUNDERSTORMS. THE
PERIOD STARTS OFF WITH AN UPPER LEVEL DISTURBANCE PASSING THROUGH
THE NORTHERN PLAINS INTO THE GREAT LAKES REGION. A STATIONARY FRONT
WILL EXIST TO THE SOUTH IN KS SATURDAY NIGHT...WHILE A COLD FRONT
ASSOCIATED WITH THE DISTURBANCE PUSHES SOUTH ACROSS THE DAKOTAS. A
STRONGER UPPER LEVEL WAVE ROTATING AROUND THE MAIN UPPER LEVEL LOW
WILL MOVE SOUTHEAST ACROSS ND/MN/WI ON MONDAY. STRONG SURFACE HIGH
PRESSURE WILL FOLLOW THIS UPPER LOW AND HELP PUSH UNSEASONABLY COOL
TEMPERATURES INTO THE REGION ON MONDAY. THE HIGH WILL SETTLE IN OVER
THE AREA MONDAY NIGHT...MAKING FOR A COOL TUESDAY MORNING. WITH THE
HIGH SLOW TO MOVE EAST...HIGHS WILL BE IN THE 70S ON TUESDAY AND
WEDNESDAY. TEMPERATURES BEGIN TO REBOUND CLOSER TO NORMAL TOWARD THE
END OF THE WEEK UNDER UPPER LEVEL RIDGING.
STRONG THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT AND SUNDAY
NIGHT. MODERATE INSTABILITY AND DEEP SHEAR OF 30-40 KTS MAY LEAD TO
A FEW SEVERE STORMS SATURDAY NIGHT. INSTABILITY AND SHEAR BOTH LOOK
A LITTLE WEAKER FOR SUNDAY...LIMITING THE SEVERE RISK A BIT COMPARED
TO SATURDAY NIGHT. THERE IS ALSO MORE UNCERTAINTY REGARDING THE
LOCATION OF THE FRONT AND INSTABILITY ON SUNDAY. A FEW OTHER CHANCES
WILL EXIST ACROSS THE AREA EARLY IN THE WEEK...PRIMARILY IN THE SW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1236 PM CDT FRI JUL 11 2014
A WARM FRONT WILL EXTEND FROM NEAR KGLD TO KLXN TO KGRI LATE THIS
AFTERNOON. UNSTABLE CONDITIONS WILL BE IN PLACE TO THE NORTH OF THE
FRONT...BUT A STOUT CAPPING INVERSION ALOFT WILL KEEP THUNDERSTORM
ACTIVITY ISOLATED AT BEST THROUGH EARLY THIS EVENING. BY MID
EVENING...A LINE OF STRONG TO POSSIBLE SEVERE THUNDERSTORMS IS
EXPECTED TO MOVE EAST OUT OF NORTHEAST COLORADO AND THE NEBRASKA
PANHANDLE. THIS ACTIVITY SHOULD REMAINED CONFINED TO AREAS GENERALLY
ALONG AND ESPECIALLY NORTH OF INTERSTATE 80. STRONG WINDS WILL BE
LIKELY WITH THIS ACTIVITY. THIS COULD IMPACT BOTH THE KLBF AND KVTN
TAF SITES THROUGH THE EVENING HOURS. VFR CONDITIONS ARE EXPECTED
OVERALL...BUT LOCAL IFR CONDITIONS ARE POSSIBLE NEAR ANY
THUNDERSTORM ACTIVITY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TAYLOR
LONG TERM...KNUTSVIG
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
328 PM MDT FRI JUL 11 2014
.SYNOPSIS...
AN ACTIVE SHOWER AND THUNDERSTORM PERIOD IS ON TAP FOR THE NEXT
WEEK. SHOWERS AND THUNDERSTORMS WILL FAVOR WESTERN AND NORTHERN
NEW MEXICO FOR THE REST OF TODAY AND SATURDAY...BEFORE THE FOCUS
SHIFTS...OR PERHAPS JUST SPREADS...INTO EASTERN NEW MEXICO SUNDAY
THROUGH MUCH OF NEXT WEEK. SEVERAL BACK DOOR COLD FRONT NEXT WEEK
WILL BE A FOCUS FOR PRECIPITATION ACROSS THE PLAINS. THIS WILL
ALSO COOL TEMPERATURES BACK BELOW NORMAL. STORMS WILL MOVE SLOWLY
ALL WEEK...THUS THE POTENTIAL FOR FLOODING EXISTS DAILY...
ESPECIALLY OVER BURN SCARS.
&&
.DISCUSSION...
WATER VAPOR AND VIS SATELLITE IMAGERY SHOWING SUBSTANTIAL DRY AIR
AND SUBSIDENCE MOVING INTO MUCH OF EASTERN AND PORTIONS OF CENTRAL
NM AHEAD OF AN EASTERLY WAVE. MONSOONAL PLUME IS CERTAINLY FOCUSED
ACROSS WESTERN NM WHERE FLASH FLOOD WATCH IS IN PLACE AND PWATS ARE
AT OR JUST ABOVE NORMAL. APPEARS LIKE THE DRY AIR HAS PUSHED FURTHER
WEST THAN MODELS SUGGESTED...BUT THE 17Z HRRR APPEARS TO BE ON TRACK
WITH SHIFTING THE FOCUS FOR PRECIPITATION TONIGHT FURTHER TO THE
NORTHWEST...WHERE THETA-E RIDGE AXIS LIES. HAVE INCREASED POPS IN
THIS AREA AS THESE LOCALES HAVE RECEIVED PLENTY OF SUNSHINE
TODAY...AND WITH GOOD INSTABILITY AND STORM MOTIONS GENERALLY TOWARD
THE WEST...IT MAKES SENSE THAT STORMS FAVOR THAT AREA TONIGHT. THERE
IS ALSO A PRECARIOUS BOUNDARY RIGHT ALONG THE NE NM/SE CO BORDER
THAT HAS RECENTLY SPARKED AN ISOLATED STORM. LOOKS LIKE THIS
BOUNDARY WILL STAY NORTH OF THE AREA...THUS HAVE KEPT POPS AT A
MINIMUM. ABQ AREA WILL BE TRICKY...AS STORMS THUS FAR HAVE STRUGGLED
THAT HAVE FORMED ON THE SANDIAS DUE TO THE DRY AIR...BUT ADDITIONAL
STORMS HAVE DEVELOPED EAST OF THE MTNS AND BASED ON STORM
MOTIONS...SHOULD ARRIVE IN ABQ PRIOR TO 6PM IF THEY HOLD TOGETHER.
THE EASTERLY WAVE SLIDES SOUTH OF THE STATE TONIGHT. THERE WILL
STILL BE SOME DRY AIR IN PLACE OVER THE EAST TOMORROW...BUT THE UPPER
HIGH THAT IS OVER THE NE NOW...WILL START TO SHIFT WNW. THIS WILL
MEAN LITTLE CHANGE FOR STORM COVERAGE AND PLACEMENT FOR SATURDAY.
MOST STORMS WILL TRAVEL WESTWARD...EXCEPT STORMS ACROSS THE NE WHICH
MAY DRIFT EASTWARD. THESE NE STORMS WILL DEVELOP ALONG A WEAK COLD
FRONT THAT WILL GENERALLY STALL ACROSS THE AREA. OUTFLOW BOUNDARIES
LATER IN THE EVENING MAY PUSH IT FURTHER SOUTH HOWEVER.
THE WEAK FRONT ACROSS THE NE LOOKS TO BE REINFORCED A BIT ON
SUNDAY...AND THIS MAY PUSH THE FRONT FURTHER SOUTH. HAVE EXPANDED
CHANCE POPS ACROSS THE NE FOR THIS REASON. OTHERWISE...THE UPPER
HIGH WILL BE CENTERED ACROSS THE GREAT BASIN...WHICH GENERALLY TILTS
THE WEAK MONSOONAL PLUME OVER INTO MORE OF THE STATE.
WITH AN EXISTING BOUNDARY IN PLAY ACROSS THE EAST...HAVE INCREASED
POPS ACROSS THE PLAINS FOR MONDAY. THEN THE STRONGER
FRONT...ASSOCIATED WITH THE STRONG UPPER LOW ACROSS THE GREAT
LAKES...WILL ARRIVE MONDAY NIGHT AND TUESDAY...PUTTING ADDITIONAL
FOCUS FOR STORMS ACROSS THE EAST. THE WEST WILL REMAIN ACTIVE
TOO...ESPECIALLY IF THE FRONT PUSHES THRU THE GAPS.
NORTHWEST FLOW WILL BE IN PLACE OVER NM MID WEEK AS THE PATTERN
BECOMES QUITE AMPLIFIED. THIS IS NOT GOOD IN TERMS OF RECEIVING
MOISTURE FROM THE SOUTH...THE TRADITIONAL MONSOON WAY...BUT REGULAR
DISTURBANCES IN THE NORTHWEST FLOW WILL CONTINUE USHER IN MOISTURE
ACROSS THE EAST BEHIND BACK DOOR FRONTS...AND ONE SUCH STRONG FRONT
LOOKS TO ARRIVE WEDNESDAY NIGHT...WHICH MAY PUSH THRU THE GAPS OF
THE CENTRAL MTN CHAIN ONCE AGAIN. THUS...AN ACTIVE PATTERN WILL
PERSIST THRU THE NEXT WEEK. MODELS ARE HINTING AT REBUILDING THE
UPPER HIGH OVER NM NEXT WEEKEND. STAY TUNED.
34
&&
.FIRE WEATHER...
AN ACTIVE MONSOON MOISTURE PLUME WILL CONTINUE WITH WETTING RAIN
OVER THE WESTERN...CENTRAL AND NORTHERN CENTRAL ZONES THIS AFTERNOON
AND SATURDAY. AN EXPANSION IN THE WETTING RAIN PATTERN WILL COMMENCE
ON SUNDAY WHEN A BACK DOOR FRONT SUPPORTS INCREASED CHANCES OF
PRECIPITATION ACROSS NORTHEASTERN ZONES. A WIDESPREAD WET PATTERN
WILL THEN BE IN PLACE FOR THE WORK WEEK WITH INCREASED CHANCES OF
BURN SCAR FLOODING.
UPPER LEVEL HIGH CURRENTLY IS CENTERED OVER EXTREME EASTERN TEXAS
WITH AN EASTERLY WAVE CENTERED JUST SOUTH OF THE BIG BEND AREA AND
SLOWLY DRIFTING TO THE NORTHWEST. A BROAD AREA OF SUBSIDENCE AHEAD
OF THE WAVE IS USHERING IN MID LEVEL DRY AIR INTO EASTERN NEW
MEXICO...THUS SHUTTING DOWN WETTING RAIN ACROSS THE EASTERN ZONES.
SURFACE MOISTURE REMAINS IN PLACE ACROSS THE EAST WHERE SOME
EXCELLENT RH RECOVERIES ARE EXPECTED TONIGHT...WITH MAINLY GOOD
VALUES ELSEWHERE.
UPCOMING PATTERN CHANGES ARE CURRENTLY DEVELOPING WELL NORTH OF NEW
MEXICO AS AN UPPER RIDGE BUILDS OVER THE WEST COAST AND AN UPPER LOW
DEEPENS OVER CENTRAL CANADA. THIS PATTERN WILL AMPLIFY STARTING
SUNDAY AS THE HIGH CONTINUES TO STRENGTHEN AS THE LOW MOVES TOWARD
THE GREAT LAKES. THE FIRST OF SEVERAL BACK DOOR FRONTS WILL EDGE
INTO THE NORTHEAST ON SUNDAY...WITH COOLER TEMPERATURES...ENHANCED
LOW LEVEL MOISTURE AND INCREASED CHANCES OF WETTING RAIN FROM THE
NORTH CENTRAL MOUNTAIN TO THE NORTHEAST PLAINS. MONSOON PLUME WILL
PERSIST ACROSS THE WEST THUS ONLY THE EXTREME EAST CENTRAL PLAINS
LOOK TO REMAIN DRY.
FOR THE WORK WEEK...THE AMPLIFIED PATTERN PERSISTS WITH HIGH
PRESSURE TO THE WEST AND REGULAR WIND SHIFTS INTO THE NORTHEAST
MAINTAINING MOIST LOW LEVEL EAST TO SOUTHEAST FLOW ACROSS THE
EASTERN PLAINS THROUGH THE WORK WEEK. EXTEND MODELS SHOW REASONABLE
AGREEMENT WITH UPPER LEVEL DISTURBANCES IN THE NORTHWEST FLOW ALOFT
ON EARLY WEDNESDAY AND AGAIN ON THURSDAY. WHILE THERE IS STILL
UNCERTAINTY IN THE TIMING OF SPECIFIC FEATURES...THE CHANCES FOR
WIDESPREAD WETTING RAIN FOR THE WORK WEEK...RESULTING IN POSSIBLE BURN
SCAR FLOODING... ARE FAIRLY CERTAIN. OVERNIGHT RH RECOVERIES LOOK TO
BE GOOD TO EXCELLENT THROUGH THE WORK WEEK. PERIODS OF POOR TO FAIR
VENTILATION CAN BE EXPECTED...ESPECIALLY ACROSS THE NORTH ON
SUNDAY...PORTIONS OF THE WEST ON MONDAY AND TUESDAY...AND THE
NORTHEAST TO EAST WEDNESDAY INTO THURSDAY.
05
&&
.AVIATION...
18Z TAF CYCLE
AMPLE MONSOON MOISTURE MOISTURE REMAINS IN PLACE ACROSS WESTERN
ZONES WHILE DRIER MID LEVEL AIR HAS MOVED OVER EASTERN ZONES.
THUNDERSTORMS WILL BE PLENTIFUL THIS AFTERNOON MAINLY ACROSS THE
NORTHERN AND WESTERN HIGHER TERRAIN. THUNDERSTORMS WILL BE NEARLY
STATIONARY OR SLOW MOVING AND CAPABLE OF MODERATE TO HEAVY
DOWNPOURS RESULTING IN LOCAL MVFR CONDITIONS AND MOUNTAIN
OBSCURATIONS. GUSTY OUTFLOWS UP TO 45 KT WILL ACCOMPANY THESE
STORMS. SHOWERS WILL LINGER DURING THE OVERNIGHT HOURS ESPECIALLY
CENTRAL VALLEYS AND WEST CENTRAL OR SOUTHWEST ZONES WITH
OCCASIONAL MVFR CONDITIONS. SURFACE MOISTURE WILL PERSIST ACROSS
THE EAST AND LOW CLOUDS ARE POSSIBLE OVER PORTIONS OF THE EASTERN
PLAINS SATURDAY MORNING...WITH BEST CHANCES AT KROW AND KCVS AND
LESSER CHANCES AT KTCC AND KLVS.
05
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 65 93 65 92 / 30 20 20 30
DULCE........................... 53 88 51 86 / 40 30 40 50
CUBA............................ 56 85 56 82 / 50 50 60 50
GALLUP.......................... 59 88 59 87 / 50 40 30 40
EL MORRO........................ 57 80 56 79 / 50 60 50 40
GRANTS.......................... 58 86 57 85 / 50 40 40 30
QUEMADO......................... 58 80 57 81 / 50 50 40 40
GLENWOOD........................ 60 87 59 88 / 40 40 40 30
CHAMA........................... 49 80 48 78 / 60 50 60 60
LOS ALAMOS...................... 61 83 61 79 / 40 40 50 40
PECOS........................... 57 79 57 76 / 40 50 40 40
CERRO/QUESTA.................... 52 80 54 76 / 50 50 50 50
RED RIVER....................... 47 74 48 69 / 50 60 60 70
ANGEL FIRE...................... 44 78 43 73 / 40 60 50 60
TAOS............................ 53 85 54 80 / 40 40 50 40
MORA............................ 54 79 54 73 / 30 50 40 50
ESPANOLA........................ 60 89 61 85 / 40 30 50 30
SANTA FE........................ 59 83 60 79 / 30 40 40 40
SANTA FE AIRPORT................ 60 88 61 85 / 30 30 40 30
ALBUQUERQUE FOOTHILLS........... 67 89 68 88 / 30 30 30 30
ALBUQUERQUE HEIGHTS............. 69 91 70 90 / 20 20 30 20
ALBUQUERQUE VALLEY.............. 67 92 67 91 / 20 20 30 20
ALBUQUERQUE WEST MESA........... 68 91 69 90 / 20 20 30 20
LOS LUNAS....................... 65 93 65 92 / 20 10 30 20
RIO RANCHO...................... 68 93 69 90 / 20 20 40 20
SOCORRO......................... 70 94 70 94 / 20 10 20 20
SANDIA PARK/CEDAR CREST......... 62 86 62 84 / 30 40 40 30
TIJERAS......................... 62 87 62 85 / 30 30 40 30
MORIARTY/ESTANCIA............... 57 84 57 83 / 20 40 30 30
CLINES CORNERS.................. 57 83 59 81 / 10 30 20 20
GRAN QUIVIRA.................... 61 84 62 83 / 20 30 20 20
CARRIZOZO....................... 64 85 64 85 / 10 20 20 20
RUIDOSO......................... 55 81 56 81 / 10 30 20 30
CAPULIN......................... 62 82 59 73 / 5 30 50 60
RATON........................... 59 86 60 78 / 5 30 40 50
SPRINGER........................ 61 88 62 81 / 5 20 20 50
LAS VEGAS....................... 55 84 56 79 / 10 20 20 30
CLAYTON......................... 64 91 65 84 / 5 5 20 50
ROY............................. 64 86 64 81 / 5 10 10 50
CONCHAS......................... 68 92 68 88 / 5 0 5 30
SANTA ROSA...................... 65 89 67 86 / 5 0 5 20
TUCUMCARI....................... 68 93 68 92 / 5 5 5 20
CLOVIS.......................... 62 88 63 89 / 5 5 5 10
PORTALES........................ 64 89 64 90 / 5 5 5 5
FORT SUMNER..................... 67 89 67 90 / 5 5 5 10
ROSWELL......................... 66 91 67 94 / 5 5 5 5
PICACHO......................... 60 85 62 86 / 5 5 5 10
ELK............................. 57 80 58 80 / 10 10 10 30
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 8 PM MDT THIS EVENING FOR THE FOLLOWING
ZONES...NMZ504-506>508-511.
&&
$$
34
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 AM EDT FRI JUL 11 2014
.SYNOPSIS...A WEAKENING SURFACE BOUNDARY WILL DRIFT TOWARD THE COAST
TODAY. WEAK HIGH PRESSURE WILL SETTLE OVER THE REGION SATURDAY AND
SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 1000 PM THURSDAY...
AFTERNOON AND EARLY EVENING CONVECTION HAS STABILIZED MOST AREAS EAST
OF US HWY 1...WHILE SPC MESOANALYSIS AND RAP SOUNDINGS SHOW AROUND
500 J/KG MLCAPE AND LESS THAN ONLY 100 J/KG MLCINH OVER THE WESTERN
PIEDMONT. THE UPPER TROUGH AND ASSOCIATED VORTICITY MAX ARE STILL
TO THE WEST...APPROACHING THE APPALACHIANS THIS EVENING. THE
PRIMARY COLD FRONT IS ALSO JUST WEST OF OR BEGINNING TO CROSS THE
MOUNTAINS...WITH A SHARP TROUGH IN THE LESS OF THE MOUNTAINS.
BLENDED TPW SHOW PW STILL WELL ABOVE 1.5 INCHES. RADAR TRENDS HAVE
BEEN DOWNWARD TO JUST A COUPLE ISOLATED SHOWERS OVER DAVIDSON AND
RANDOLPH/CHATHAM COUNTIES....AND THE HRRR SHOWS VERY LITTLE QPF
AFTER MIDNIGHT. THERE MAY STILL BE A FEW SHOWERS OR AN ISOLATED
STORM GIVEN THE AFOREMENTIONED FORCING...ESPECIALLY WITH THE UPPER
VORT MAX AND PRIMARY COLD FRONT. WILL LOWER POPS A BIT
AREAWIDE...WHILE KEEPING A SLIGHT CHANCE WEST AND CHANCE EAST. ALSO
ADDING PATCHY FOG GIVEN THE WIDESPREAD RAIN AND PARTIAL CLEARING
AHEAD OF THE FRONT. -BLS
FOR FRI/FRI NIGHT: AS THE DAMPENING SHEAR AXIS SHIFTS TO OUR SE IN
LINE WITH THE DISSIPATING SURFACE TROUGH... THE HIGHER PW VALUES
WILL ACCORDINGLY SHIFT TO THE COASTAL PLAIN... LEAVING A LIGHT NNE
LOW LEVEL FLOW AND RELATIVELY (FOR JULY) DRY COLUMN OVER THE NRN AND
WRN CWA. MODELS GENERALLY INDICATE VERY LITTLE PRECIP COVERAGE...
CONFINING AFTERNOON CONVECTION TO THE COASTAL PLAIN AND SE SANDHILLS
WHERE MODELS PROJECT MUCAPE PEAKING AT 1000-1500 J/KG. WILL RETAIN
CHANCE POPS HERE WITH ISOLATED CHANCES TO THE NW. A DIP IN
THICKNESSES TO SLIGHTLY BELOW NORMAL VALUES SUPPORTS HIGHS OF 85-90.
EXPECT LITTLE MORE THAN PATCHY SHOWERS FRI NIGHT. LOWS 66-71. -GIH
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 315 PM THURSDAY...
THE MID LEVEL TROUGH AXIS (CURRENTLY MOVING TOWARDS THE AREA) WILL
PUSH OFFSHORE ON SATURDAY...WHILE THE MID LEVEL RIDGE TRIES TO BUILD
EASTWARD TOWARDS THE REGION. MODELS HAVE TRENDED DRIER FOR THE
WEEKEND...ESPECIALLY ON SATURDAY GIVEN THE DRIER AIR FILTERING INTO
THE REGION BEHIND THE DEPARTING TROUGH. IN FACT...FORECAST SOUNDINGS
INDICATE VERY LIMITED DEEP LAYER MOISTURE...WITH PWAT VALUES PROGGED
TO RANGE BETWEEN 1-1.25 INCHES (WELL BELOW NORMAL). THEREFORE...
WILL GO WITH A MOSTLY DRY FORECAST FOR SATURDAY. MOISTURE WILL START
TO RECOVER SOME ON SUNDAY AND A SURFACE TROUGH WILL SHARPEN UP OVER
THE REGION...LEADING TO A BETTER CHANCE OF MOSTLY DIURNAL TYPE
STORMS...ALTHOUGH OVERALL COVERAGE SHOULD STILL BE RATHER LOW. LOW
LEVEL THICKNESS VALUES ARE PROGGED TO BE NEAR 1420M ON SATURDAY AND
GIVEN EXPECTED LACK OF PRECIP...TEMPS SHOULD RISE INTO THE UPPER 80S
TO LOWER 90S. BY SUNDAY...LOW LEVEL THICKNESS VALUES ARE EXPECTED TO
CLIMB ANOTHER 5-10M...RESULTING HIGH TEMPS A FEW DEGREES
WARMER...GENERALLY LOW TO MID 90S (ALTHOUGH MORE CLOUDS MAY BE
AROUND WHICH WOULD TEMPER THE WARMING SOME).
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 315 PM THURSDAY...
A DEEP VORTEX IS PROGGED TO MOVE SOUTH OUT OF CANADA AND EVENTUALLY
ACROSS THE GREAT LAKES THROUGH THE MIDDLE OF NEXT WEEK. THIS WILL
RESULT IN A DEEP TROUGH DEVELOPING OVER THE EASTERN HALF OF THE
CONUS. THEREFORE...PRECIP CHANCES WILL BE ON THE INCREASE FOR NEXT
WEEK...ESPECIALLY LATE TUESDAY INTO EARLY WEDNESDAY AS A FRONT
APPROACHES THE AREA. ALSO...GIVEN THIS UNSEASONABLY STRONG TROUGH...
THE MID LEVEL FLOW IS EXPECTED TO STRENGTHEN AND THEREFORE THE
POSSIBILITY OF AN ORGANIZED SEVERE THREAT WILL EXIST AND THIS WILL BE
MONITORED OVER THE NEXT SEVERAL DAYS. THEN THERE IS STILL A GOOD BIT
OF UNCERTAINTY WITH REGARDS TO IF THIS FRONT WILL PUSH ALL THE WAY
THROUGH THE AREA...BUT FOR NOW IT LOOKS LIKE THE FRONT WILL STALL
SOMEWHERE ACROSS THE CAROLINAS. THUS...WILL SHOW A LITTLE DECREASE
IN POPS FOR THE LATTER HALF OF THE WEEK...BUT WILL KEEP A CHANCE IN
GIVEN THE UNCERTAINTY WITH REGARDS TO WHERE THE FRONT ENDS UP. HIGH
TEMPS AHEAD OF THE FRONT ARE EXPECTED TO BE IN THE LOW TO MID 90S ON
MONDAY AND POSSIBLY TUESDAY...ALTHOUGH DEPENDING ON THE TIMING OF
THE PRECIP...TEMPS COULD BE SLIGHTLY LOWER ON TUESDAY. THEN SLIGHTLY
COOLER TEMPS ARE EXPECTED WEDNESDAY AND THURSDAY GIVEN THE DEEP
TROUGHING OVER THE EAST COAST AND THE POSSIBILITY THAT THE FRONT
WILL PUSH THROUGH THE AREA.
&&
AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 145 AM FRIDAY...
A NEARLY SATURATED LOW LEVEL AIR MASS WILL SUPPORT THE DEVELOPMENT
OF WIDESPREAD FOG AND LOW CLOUDS OVERNIGHT...AND INTO THE FIRST HALF
OF THIS MORNING. THIS SHOULD LEAD TO WIDESPREAD IFR/LIFR
CONDITIONS. IN ADDITION...COULD SEE A FEW SHOWERS DEVELOP ALONG A
SLOW MOVING SURFACE FRONT OVER THE SANDHILLS AND COASTAL PLAIN
OVERNIGHT INTO THE MID MORNING HOURS.
BETWEEN 14Z AND 16Z...SHOULD SEE VISIBILITIES AND CEILINGS IMPROVE
THOUGH STILL EXPECT MVFR CEILINGS TO OCCUR AT ALL TAF SITES.
AFTER 16Z...AS DRIER AIR BECOMES MORE ESTABLISHED OVER THE WESTERN
AND NORTHERN PIEDMONT...SHOULD SEE MVFR CEILINGS LIFT INTO A
SCATTERED STRATOCUMULUS FIELD WITH BASES 2000-3000FT.
ELSEWHERE...MVFR CEILINGS WILL PERSIST WITH CEILINGS 1500-2800FT
EXPECTED. IN ADDITION WILL SEE AN INCREASE IN SHOWER AND
THUNDERSTORM COVERAGE OVER THE COASTAL PLAIN THOUGH EXPECT MOST OF
THE ACTIVITY TO OCCUR TO THE EAST-SE OF KFAY AND KRWI.
FRIDAY NIGHT THROUGH SUNDAY...A WEAK AREA OF HIGH PRESSURE WILL
BUILD THEN SETTLE INTO THE REGION. THIS WEATHER SYSTEM SHOULD
MAINTAIN VFR CONDITIONS ACROSS CENTRAL NC.
THE WEATHER PATTERN WILL GRADUALLY BECOME UNSETTLED EARLY NEXT WEEK
AS A LOW PRESSURE SYSTEM APPROACHES FROM THE NORTHWEST. THIS SHOULD
LEAD TO AN INCREASE IN LOW AND MID LEVEL MOISTURE...RESULTING IN
EARLY MORNING FOG AND LOW CLOUDS. ALSO...EXPECT PERIODS OF MVFR
CEILINGS AND VISIBILITY DUE TO SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON...ESPECIALLY TUESDAY AFTERNOON INTO TUESDAY NIGHT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/BLS
SHORT TERM...KRD
LONG TERM...KRD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1000 PM CDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 1000 PM CDT SAT JUL 12 2014
BUMPED UP WINDS A BIT CLOSER TO WHAT THE HRRR HAS AS WINDS ALONG
THE GUST FRONT AS IT CONTINUES THROUGH OUR SOUTHERN COUNTIES HAVE
BEEN PRETTY STRONG. SHOWERS CONTINUE FROM THE CENTRAL RED RIVER
VALLEY TOWARDS BEMIDJI...AND THE SHORT RANGE MODELS CONTINUE TO
HAVE THE ACTIVITY MOVING SOUTH AND BECOMING WEAKER AND MORE
SCATTERED. ADJUSTED POPS ACCORDINGLY.
UPDATE ISSUED AT 650 PM CDT SAT JUL 12 2014
ADJUSTED POPS FOR LINE OF STORMS MOVING THROUGH THE NORTHERN
COUNTIES. MESOSCALE MODELS PERSIST IN EVENTUALLY BREAKING UP THE
LINE AS IT MOVES SOUTH...A LITTLE LESS SO IN OUR EASTERN COUNTIES.
GIVEN THE WEAKENING INSTABILITY FURTHER SOUTH THIS SEEMS
REASONABLE. KEPT POPS DECREASING THROUGH THIS EVENING BEFORE
EVENTUALLY ENDING AFTER MIDNIGHT. RAIN COOLED AIR HAS ALREADY
DROPPED TEMPS INTO THE 50S ALONG THE NORTHERN TIER...SO LOWERED
TEMPS FOR THE REST OF THE EVENING BUT KEPT LOWS AROUND 50 FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 310 PM CDT SAT JUL 12 2014
IN THE VERY NEAR TERM THE MAIN FOCUS IS THE SLIGHT RISK OF SEVERE
WEATHER EARLY THIS EVENING. WV SHOWS STRONG DRY PUNCH...SUGGESTIVE
OF JET DEPICTED IN MODELS...PUNCHING RAPIDLY SOUTH. VARIOUS HIGH
RES MODELS SHOW A FAST MOVING LINE OF TSRA ALONG COLD FRONT. MARGINAL
INSTABILITY...0 - 1KM CAPE TO 700 J/KG AND SWI -2C BUT 0 - 6KM
BULK SHEAR CLIMBS TO 60KTS AT 00Z...YET IS POST FRONTAL. BASED ON
THE ATMOSPHERIC PROFILE SUSPECT MAIN THREAT IS DAMAGING WINDS. 15Z
SREF 3HR SVR TSTM PROB SUPPORTS +TSRA 21Z - 03Z.
FRONTAL BOUNDARY ZIPS THROUGH CWFA OVERNIGHT. WINDS SHOULD
DIMINISH AFTER INITIAL PUSH WITH CONVECTION AND LOW LEVEL CAA IS
SPENT. FROM A BOUNDARY LAYER STANDPOINT THE AIRMASS IS ONLY
SLIGHTLY COOLER 12Z SUNDAY THAN 12Z THIS MORNING. SO EXPECT MIN
TEMPS A FEW DEGREES LOWER THAN SATURDAY. STRONGER LOW LEVEL CAA
DEVELOPS DURING THE DAY SO TEMPERATURES WILL BE SLOW TO
RECOVER....HIGHS PERHAPS 10F COOLER. WINDS INCREASE AS WELL WITH
DIRECTION FAVORING A MORE EFFECTIVE MIXING PROFILE. VARIOUS
GUIDANCE SUGGEST A WINDY DAY...PERHAPS CLOSE TO WIND ADV CRITERIA
BY SUNDAY AFTERNOON.
WINDS DIMINISH SUNDAY NIGHT BUT SUSTAINED LOW LEVEL CAA
...ISALLOBARIC COMPONENT AND 30+KTS AT 850 SUGGEST ONLY MODEST
DECREASE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT JUL 12 2014
DEEP UPPER LOW HAS BEEN CONSISTENTLY FORECAST TO DROP FROM SOUTHWEST
ONTARIO INTO THE WESTERN GREAT LAKES MONDAY. BEST CHANCE FOR
SHOWERS SHOULD BE CLOSER TO THE DEEP CIRCULATION. WITH COLDER AIR
ALOFT -RASH POSSIBLE WEST OF RRV AS WELL. LACK OF SIGNIFICANT
INSTABILITY WILL NOT INTRODUCE THUNDER...BUT ISOLD -TSRA PSBL DUE
TO STRENGTH OF 700 COLD POOL.
VARIOUS MODELS HAVE CONTINUED TO COME CLOSER TOGETHER PAINTING MONDAY
AS A CHILLY MID JULY DAY. DYNAMIC MODELS TEND TO BE WARMER WHILE THE
MOS/BC/WEIGHTED MODELS COOLER. LOCAL VERIFICATION SUGGESTS THE
DYNAMIC MODELS HAVE BEEN TOO WARM SO WILL LEAN TOWARDS THE
WEIGHTED MOS/BC VERSIONS. LATEST FORECASTS STILL PRESENT
POSSIBILITY OF RECORD OR NEAR RECORD LOW MAXIMUM TEMPERATURES
MONDAY.
QUITE WEATHER FOR TUESDAY AS HIGH SETTLES IN AND GRADIENT RELAXES.
LOW LEVEL THERMAL PROFILE SUGGESTS 2C TO 4C WARMING AND SHOULD BE A
FAIR AMOUNT OF SOLAR...YET LACK OF MIXING KEEPS TEMPERATURE BELOW
MEDIAN.
SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT (WITHOUT MUCH
EVIDENCE OF ANY SHORT WAVE ACTION) SHOULD MEAN MAINLY SUNNY DRY
WEATHER FOR THE WED/THUR TIME FRAME COMING OUT OF OUR UNSEASONABLY
START TO THE WEEK. THE MERCURY WILL STILL BE RECOVERING WEDNESDAY
BEFORE HEADING TO MORE AVERAGE LEVELS THURSDAY AND FRIDAY. GFS (AND
TO A LESSER EXTENT THE ECMWF) IS PAINTING ANOTHER DEEPER LOW SCENARIO
NEAR INTERNATIONAL BORDER BY FRIDAY/SATURDAY...WITH ASSOCIATED
VOLUMINOUS PRECIPITATION AMOUNTS. THIS SEEMS SUSPECT AT THIS TIME
AND HAVE ONLY INCLUDED LOW POPS MAINLY EASTERN FORECAST AREA FOR
NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 650 PM CDT SAT JUL 12 2014
LINE OF THUNDERSTORMS WILL BE MOVING INTO KDVL SHORTLY AND KGFK
AND KTVF IN THE NEXT HOUR OR SO. WILL KEEP VCTS AND VFR CIGS AND
AMEND AS NEEDED AS ONLY THE HEAVIER CELLS HAVE BEEN REDUCING
CATEGORIES AT ALL. WINDS MAY BE AN ISSUE AS THE STORMS MOVE
THROUGH AS THERE HAVE BEEN SOME GUSTS UP AROUND 40 KTS IN SOME
PLACES. THE STORMS WILL WEAKEN AS THEY MOVE SOUTH AND CONDITIONS
WILL BE MORE QUIET AFTER 06Z. VFR CONDITIONS AND NORTHWEST WINDS
UNDER 12 KTS WILL PREVAIL THROUGH EARLY MORNING. WINDS WILL PICK
UP AGAIN AND BECOME RATHER BREEZY WITH GUSTS ABOVE 25 KTS BY MID
MORNING. WITH CONVECTIVE TEMPS IN THE MID 60S...THINK THAT MOSTLY
CLEAR SKIES WILL GIVE WAY TO A STRATOCU DECK BY MID DAY. CIGS
SHOULD REMAIN ABOVE 5000 FT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...EWENS
LONG TERM...WJB
AVIATION...JR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
116 PM CDT FRI JUL 11 2014
.UPDATE...
ISSUED AT 115 PM CDT FRI JUL 11 2014
QUICK UPDATE TO FURTHER EXPAND ISOLATED SHOWERS/THUNDERSTORMS FROM
SOUTHWEST THROUGH SOUTH CENTRAL AND INTO THE JAMES RIVER VALLEY.
OTHERWISE NO OTHER CHANGES FROM PREVIOUS FORECAST.
UPDATE ISSUED AT 1210 PM CDT FRI JUL 11 2014
LATEST LOCAL/REGIONAL RADAR SHOWS ISOLATED THUNDERSTORMS INTO
SOUTHWEST NORTH DAKOTA...PART OF THE SAME SHORTWAVE ENERGY AND JET
SUPPORT THAT WAS ACROSS THE NORTHWEST EARLIER THIS MORNING.
OBSERVATIONS OUTSIDE THE BISMARCK OFFICE SHOW A MID LEVEL CAP IS
CURRENTLY IN PLACE. HOWEVER...DECENT MID LEVEL LAPSE RATES AND
SHEAR PER SPC MESOANALYSIS IS MAINTAINING CURRENT AREA OF
PRECIPITATION AS IT CONTINUES TO ADVANCE EAST. HAVE NUDGED THE
ISOLATED PRECIPITATION AREA SLIGHTLY FARTHER EAST THIS AFTERNOON
GIVEN LATEST TRENDS. OTHERWISE THE REST OF THE FORECAST REMAINS IN
GOOD SHAPE
FOR TONIGHT...THE LATEST GFS IS MUCH DRIER FOR THE OVERNIGHT
PERIOD INTO SATURDAY MORNING...WHICH IS OPPOSITE OF THE 12Z NAM
SOLUTION. THE LATEST CANADIAN GEM MAINTAINS PRECIPITATION OVER
SOUTHWEST AND SOUTHERN NORTH DAKOTA TONIGHT INTO SATURDAY MORNING.
WILL AWAIT THE ECMWF BEFORE MAKING CHANGES AND COLLABORATE WITH
NEIGHBORING OFFICES BEFORE MAKING CHANGES.
UPDATE ISSUED AT 802 AM CDT FRI JUL 11 2014
LATEST SURFACE ANALYSIS PLACES THE COLD FRONT INTO THE JAMES RIVER
VALLEY WITH 3HR PRESSURE RISES INCREASING RAPIDLY FARTHER WEST.
PATCHY FOG MAINLY ALONG AND AHEAD OF THE FRONT CONTINUES BUT
IMPROVING CONDITIONS HAVE BEGUN AS EXPECTED FROM PREVIOUS FORECAST.
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS IN NORTHEAST MONTANA
ALSO WEAKENING WITH TIME AS THEY MOVE INTO NORTHWESTERN NORTH
DAKOTA. THE LATEST HRRR AND RAP13 SHOW THESE SHOWERS WANING
THROUGH THE MORNING HOURS BEFORE ENDING BETWEEN 16Z-17Z. OVERALL
THE CURRENT GRIDDED FORECAST IN ON TRACK.
UPDATE ISSUED AT 609 AM CDT FRI JUL 11 2014
AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST MONTANA NEAR
RIGHT ENTRANCE REGION OF UPPER JET KEEP TRYING TO PUSH EAST...BUT
STRUGGLE TO HOLD TOGETHER ONCE THEY APPROACH THE STATE LINE.
EXPECT A FEW WILL START TO HOLD TOGETHER SO WILL MAINTAIN LOW POPS
AND PUSH THE POPS EAST A LITTLE. PATCHY FOG CONTINUES OVER THE
AREA...BUT EXPECT THIS TO IMPROVE NOT LONG AFTER SUNRISE. UPDATES
HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT FRI JUL 11 2014
MAIN FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE THE
CHANCE FOR SHOWERS AND THUNDERSTORMS NOW THROUGH TONIGHT.
CURRENTLY...FRONTAL BOUNDARY CONTINUES TO MOVE SLOWLY SOUTH AND
EAST ACROSS THE STATE...NOW POSITIONED ACROSS CENTRAL NORTH
DAKOTA. THE OUTFLOW BOUNDARY WHICH EARLIER PRODUCED A FEW
STRONGER STORMS NORTH CENTRAL...CONTINUES TO GENERATE WEAK
CONVECTION AS IT MOVES SOUTH. PAST HOUR HAVE SEEN WEAK ECHOS
DEVELOP ACROSS SHERIDAN AND NORTHERN BURLEIGH COUNTIES. WILL
MAINTAIN A MENTION OF SHOWERS/THUNDERSTORMS FOR THESE AREAS AND
ACROSS MY SOUTHEAST THROUGH 12Z FOR THIS FEATURE. ADDITIONAL
SHOWERS AND THUNDERSTORMS DEVELOPED THE PAST FEW HOURS ACROSS
NORTHERN MONTANA UNDER THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL
JET STREAK MOVING SLOWLY EAST ALONG THE INTERNATIONAL BORDER.
SOME OF THIS ACTIVITY MAY ENTER WESTERN NORTH DAKOTA...MAINLY AFTER
12Z.
WILL ALSO MAINTAIN PATCHY FOG WORDING THROUGH 15Z BASED ON LATEST
OBSERVATIONS.
FOR TODAY...FORCING ASSOCIATED WITH THE UPPER JET STREAK REALLY
DOES NOT MATERIALIZE ACROSS NORTH DAKOTA UNTIL TONIGHT WHEN
DIVERGENCE ALOFT INCREASES. MAY SEE SOME ELEVATED
SHOWERS/THUNDERSTORMS THIS MORNING/AFTERNOON WEST...BUT DOES APPEAR
MOST SHOWER/THUNDERSTORM ACTIVITY WILL NOT GET GOING UNTIL AFTER
00Z. WHEN IT DOES...EXPECT PRECIPITATION TO BE CONFINED TO THE
SOUTHERN ONE HALF...IF NOT SOUTHERN ONE THIRD...WITH SUBSIDENCE
ASSOCIATED WITH SURFACE HIGH PRESSURE OVER MY NORTH. THE THREAT
FOR SEVERE WEATHER SHOULD REMAIN OFF TO OUR SOUTH WITH MODELS
INDICATING A STABLE AIRMASS OVER MUCH OF THE STATE. THE FAR SOUTH
WILL SEE THE BEST CHANCE FOR A STRAY STRONGER STORM OR
TWO...MAINLY LATE THIS AFTERNOON OR EVENING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI JUL 11 2014
ON SATURDAY...DEEPENING UPPER LOW SLIDES DOWN THE WESTERN SHORES OF
HUDSON BAY WHILE A FEW WAVES CONTINUE TO SWING THROUGH CYCLONIC FLOW
ALOFT THRU THE AREA. THIS WILL KEEP CHANCES FOR SHOWERS/STORMS IN
THE FORECAST PRIMARILY OVER SOUTHERN NORTH DAKOTA.
SUNDAY INTO MONDAY...AFOREMENTIONED UPPER LOW CONTINUES ITS
SOUTHERLY SLIDE TOWARDS NORTHERN MINNESOTA/LAKE SUPERIOR. MODELS
CONTINUE TO BE IN PRETTY GOOD AGREEMENT WITH THE TRACK OF THIS
SYSTEM. COOLER AIRMASS SWINGING AROUND THE LOW WILL PUSH INTO THE
AREA...WITH THE MAIN PUSH COMING LATE SUNDAY INTO MONDAY. THIS WILL
BRING WELL BELOW AVERAGE TEMPS TO THE REGION EARLY NEXT WEEK...WITH
MOST LOCATIONS SEEING HIGHS AROUND 15 TO 20 DEGREES BELOW AVERAGE ON
MONDAY. WILL HAVE TO WATCH THE TREND WITH THIS AS TEMPS MAY NEED TO
BE LOWERED EVEN FURTHER. A FEW SHOWERS WILL BE POSSIBLE ON MONDAY AS
VARIETY OF WAVES WRAP THROUGH CYCLONIC FLOW...PARTICULARLY FROM THE
TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY.
FOR THE REMAINDER OF THE EXTENDED...UPPER LOW MOVES OFF TO THE EAST
WHILE RIDGE OVER THE WESTERN CONUS KEEPS NORTHWEST FLOW OVER OUR
AREA KEEPING CONDITIONS MAINLY DRY. TEMPERATURES WILL WARM THROUGH
MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1210 PM CDT FRI JUL 11 2014
VFR CIGS/VSBYS EXPECTED THROUGH THE PERIOD. EXPECT ISOLATED SHOWERS
AND THUNDERSTORMS THROUGH 00Z SATURDAY AT KDIK. THERE WILL BE A
RENEWED THREAT FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
AT KDIK MAINLY AFTER 05Z SATURDAY. THIS MAY REACH KBIS AND HENCE A
VCSH IS IN THE OVERNIGHT PERIOD FORECAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...NH
LONG TERM...JJS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1210 PM CDT FRI JUL 11 2014
.UPDATE...
ISSUED AT 1210 PM CDT FRI JUL 11 2014
LATEST LOCAL/REGIONAL RADAR SHOWS ISOLATED THUNDERSTORMS INTO
SOUTHWEST NORTH DAKOTA...PART OF THE SAME SHORTWAVE ENERGY AND JET
SUPPORT THAT WAS ACROSS THE NORTHWEST EARLIER THIS MORNING.
OBSERVATIONS OUTSIDE THE BISMARCK OFFICE SHOW A MID LEVEL CAP IS
CURRENTLY IN PLACE. HOWEVER...DECENT MID LEVEL LAPSE RATES AND
SHEAR PER SPC MESOANALYSIS IS MAINTAINING CURRENT AREA OF
PRECIPITATION AS IT CONTINUES TO ADVANCE EAST. HAVE NUDGED THE
ISOLATED PRECIPITATION AREA SLIGHTLY FARTHER EAST THIS AFTERNOON
GIVEN LATEST TRENDS. OTHERWISE THE REST OF THE FORECAST REMAINS IN
GOOD SHAPE
FOR TONIGHT...THE LATEST GFS IS MUCH DRIER FOR THE OVERNIGHT
PERIOD INTO SATURDAY MORNING...WHICH IS OPPOSITE OF THE 12Z NAM
SOLUTION. THE LATEST CANADIAN GEM MAINTAINS PRECIPITATION OVER
SOUTHWEST AND SOUTHERN NORTH DAKOTA TONIGHT INTO SATURDAY MORNING.
WILL AWAIT THE ECMWF BEFORE MAKING CHANGES AND COLLABORATE WITH
NEIGHBORING OFFICES BEFORE MAKING CHANGES.
UPDATE ISSUED AT 802 AM CDT FRI JUL 11 2014
LATEST SURFACE ANALYSIS PLACES THE COLD FRONT INTO THE JAMES RIVER
VALLEY WITH 3HR PRESSURE RISES INCREASING RAPIDLY FARTHER WEST.
PATCHY FOG MAINLY ALONG AND AHEAD OF THE FRONT CONTINUES BUT
IMPROVING CONDITIONS HAVE BEGUN AS EXPECTED FROM PREVIOUS FORECAST.
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS IN NORTHEAST MONTANA
ALSO WEAKENING WITH TIME AS THEY MOVE INTO NORTHWESTERN NORTH
DAKOTA. THE LATEST HRRR AND RAP13 SHOW THESE SHOWERS WANING
THROUGH THE MORNING HOURS BEFORE ENDING BETWEEN 16Z-17Z. OVERALL
THE CURRENT GRIDDED FORECAST IN ON TRACK.
UPDATE ISSUED AT 609 AM CDT FRI JUL 11 2014
AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST MONTANA NEAR
RIGHT ENTRANCE REGION OF UPPER JET KEEP TRYING TO PUSH EAST...BUT
STRUGGLE TO HOLD TOGETHER ONCE THEY APPROACH THE STATE LINE.
EXPECT A FEW WILL START TO HOLD TOGETHER SO WILL MAINTAIN LOW POPS
AND PUSH THE POPS EAST A LITTLE. PATCHY FOG CONTINUES OVER THE
AREA...BUT EXPECT THIS TO IMPROVE NOT LONG AFTER SUNRISE. UPDATES
HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT FRI JUL 11 2014
MAIN FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE THE
CHANCE FOR SHOWERS AND THUNDERSTORMS NOW THROUGH TONIGHT.
CURRENTLY...FRONTAL BOUNDARY CONTINUES TO MOVE SLOWLY SOUTH AND
EAST ACROSS THE STATE...NOW POSITIONED ACROSS CENTRAL NORTH
DAKOTA. THE OUTFLOW BOUNDARY WHICH EARLIER PRODUCED A FEW
STRONGER STORMS NORTH CENTRAL...CONTINUES TO GENERATE WEAK
CONVECTION AS IT MOVES SOUTH. PAST HOUR HAVE SEEN WEAK ECHOS
DEVELOP ACROSS SHERIDAN AND NORTHERN BURLEIGH COUNTIES. WILL
MAINTAIN A MENTION OF SHOWERS/THUNDERSTORMS FOR THESE AREAS AND
ACROSS MY SOUTHEAST THROUGH 12Z FOR THIS FEATURE. ADDITIONAL
SHOWERS AND THUNDERSTORMS DEVELOPED THE PAST FEW HOURS ACROSS
NORTHERN MONTANA UNDER THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL
JET STREAK MOVING SLOWLY EAST ALONG THE INTERNATIONAL BORDER.
SOME OF THIS ACTIVITY MAY ENTER WESTERN NORTH DAKOTA...MAINLY AFTER
12Z.
WILL ALSO MAINTAIN PATCHY FOG WORDING THROUGH 15Z BASED ON LATEST
OBSERVATIONS.
FOR TODAY...FORCING ASSOCIATED WITH THE UPPER JET STREAK REALLY
DOES NOT MATERIALIZE ACROSS NORTH DAKOTA UNTIL TONIGHT WHEN
DIVERGENCE ALOFT INCREASES. MAY SEE SOME ELEVATED
SHOWERS/THUNDERSTORMS THIS MORNING/AFTERNOON WEST...BUT DOES APPEAR
MOST SHOWER/THUNDERSTORM ACTIVITY WILL NOT GET GOING UNTIL AFTER
00Z. WHEN IT DOES...EXPECT PRECIPITATION TO BE CONFINED TO THE
SOUTHERN ONE HALF...IF NOT SOUTHERN ONE THIRD...WITH SUBSIDENCE
ASSOCIATED WITH SURFACE HIGH PRESSURE OVER MY NORTH. THE THREAT
FOR SEVERE WEATHER SHOULD REMAIN OFF TO OUR SOUTH WITH MODELS
INDICATING A STABLE AIRMASS OVER MUCH OF THE STATE. THE FAR SOUTH
WILL SEE THE BEST CHANCE FOR A STRAY STRONGER STORM OR
TWO...MAINLY LATE THIS AFTERNOON OR EVENING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI JUL 11 2014
ON SATURDAY...DEEPENING UPPER LOW SLIDES DOWN THE WESTERN SHORES OF
HUDSON BAY WHILE A FEW WAVES CONTINUE TO SWING THROUGH CYCLONIC FLOW
ALOFT THRU THE AREA. THIS WILL KEEP CHANCES FOR SHOWERS/STORMS IN
THE FORECAST PRIMARILY OVER SOUTHERN NORTH DAKOTA.
SUNDAY INTO MONDAY...AFOREMENTIONED UPPER LOW CONTINUES ITS
SOUTHERLY SLIDE TOWARDS NORTHERN MINNESOTA/LAKE SUPERIOR. MODELS
CONTINUE TO BE IN PRETTY GOOD AGREEMENT WITH THE TRACK OF THIS
SYSTEM. COOLER AIRMASS SWINGING AROUND THE LOW WILL PUSH INTO THE
AREA...WITH THE MAIN PUSH COMING LATE SUNDAY INTO MONDAY. THIS WILL
BRING WELL BELOW AVERAGE TEMPS TO THE REGION EARLY NEXT WEEK...WITH
MOST LOCATIONS SEEING HIGHS AROUND 15 TO 20 DEGREES BELOW AVERAGE ON
MONDAY. WILL HAVE TO WATCH THE TREND WITH THIS AS TEMPS MAY NEED TO
BE LOWERED EVEN FURTHER. A FEW SHOWERS WILL BE POSSIBLE ON MONDAY AS
VARIETY OF WAVES WRAP THROUGH CYCLONIC FLOW...PARTICULARLY FROM THE
TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY.
FOR THE REMAINDER OF THE EXTENDED...UPPER LOW MOVES OFF TO THE EAST
WHILE RIDGE OVER THE WESTERN CONUS KEEPS NORTHWEST FLOW OVER OUR
AREA KEEPING CONDITIONS MAINLY DRY. TEMPERATURES WILL WARM THROUGH
MID-WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1210 PM CDT FRI JUL 11 2014
VFR CIGS/VSBYS EXPECTED THROUGH THE PERIOD. EXPECT ISOLATED SHOWERS
AND THUNDERSTORMS THROUGH 00Z SATURDAY AT KDIK. THERE WILL BE A
RENEWED THREAT FOR SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
AT KDIK MAINLY AFTER 05Z SATURDAY. THIS MAY REACH KBIS AND HENCE A
VCSH IS IN THE OVERNIGHT PERIOD FORECAST.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...NH
LONG TERM...JJS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
802 AM CDT FRI JUL 11 2014
.UPDATE...
ISSUED AT 802 AM CDT FRI JUL 11 2014
LATEST SURFACE ANALYSIS PLACES THE COLD FRONT INTO THE JAMES RIVER
VALLEY WITH 3HR PRESSURE RISES INCREASING RAPIDLY FARTHER WEST.
PATCHY FOG MAINLY ALONG AND AHEAD OF THE FRONT CONTINUES BUT
IMPROVING CONDITIONS HAVE BEGUN AS EXPECTED FROM PREVIOUS FORECAST.
AREA OF SHOWERS AND ISOLATED THUNDERSTORMS IN NORTHEAST MONTANA
ALSO WEAKENING WITH TIME AS THEY MOVE INTO NORTHWESTERN NORTH
DAKOTA. THE LATEST HRRR AND RAP13 SHOW THESE SHOWERS WANING
THROUGH THE MORNING HOURS BEFORE ENDING BETWEEN 16Z-17Z. OVERALL
THE CURRENT GRIDDED FORECAST IN ON TRACK.
UPDATE ISSUED AT 609 AM CDT FRI JUL 11 2014
AREA OF SHOWERS AND THUNDERSTORMS OVER NORTHEAST MONTANA NEAR
RIGHT ENTRANCE REGION OF UPPER JET KEEP TRYING TO PUSH EAST...BUT
STRUGGLE TO HOLD TOGETHER ONCE THEY APPROACH THE STATE LINE.
EXPECT A FEW WILL START TO HOLD TOGETHER SO WILL MAINTAIN LOW POPS
AND PUSH THE POPS EAST A LITTLE. PATCHY FOG CONTINUES OVER THE
AREA...BUT EXPECT THIS TO IMPROVE NOT LONG AFTER SUNRISE. UPDATES
HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT FRI JUL 11 2014
MAIN FORECAST HIGHLIGHT IN THE SHORT TERM PERIOD WILL BE THE
CHANCE FOR SHOWERS AND THUNDERSTORMS NOW THROUGH TONIGHT.
CURRENTLY...FRONTAL BOUNDARY CONTINUES TO MOVE SLOWLY SOUTH AND
EAST ACROSS THE STATE...NOW POSITIONED ACROSS CENTRAL NORTH
DAKOTA. THE OUTFLOW BOUNDARY WHICH EARLIER PRODUCED A FEW
STRONGER STORMS NORTH CENTRAL...CONTINUES TO GENERATE WEAK
CONVECTION AS IT MOVES SOUTH. PAST HOUR HAVE SEEN WEAK ECHOS
DEVELOP ACROSS SHERIDAN AND NORTHERN BURLEIGH COUNTIES. WILL
MAINTAIN A MENTION OF SHOWERS/THUNDERSTORMS FOR THESE AREAS AND
ACROSS MY SOUTHEAST THROUGH 12Z FOR THIS FEATURE. ADDITIONAL
SHOWERS AND THUNDERSTORMS DEVELOPED THE PAST FEW HOURS ACROSS
NORTHERN MONTANA UNDER THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL
JET STREAK MOVING SLOWLY EAST ALONG THE INTERNATIONAL BORDER.
SOME OF THIS ACTIVITY MAY ENTER WESTERN NORTH DAKOTA...MAINLY AFTER
12Z.
WILL ALSO MAINTAIN PATCHY FOG WORDING THROUGH 15Z BASED ON LATEST
OBSERVATIONS.
FOR TODAY...FORCING ASSOCIATED WITH THE UPPER JET STREAK REALLY
DOES NOT MATERIALIZE ACROSS NORTH DAKOTA UNTIL TONIGHT WHEN
DIVERGENCE ALOFT INCREASES. MAY SEE SOME ELEVATED
SHOWERS/THUNDERSTORMS THIS MORNING/AFTERNOON WEST...BUT DOES APPEAR
MOST SHOWER/THUNDERSTORM ACTIVITY WILL NOT GET GOING UNTIL AFTER
00Z. WHEN IT DOES...EXPECT PRECIPITATION TO BE CONFINED TO THE
SOUTHERN ONE HALF...IF NOT SOUTHERN ONE THIRD...WITH SUBSIDENCE
ASSOCIATED WITH SURFACE HIGH PRESSURE OVER MY NORTH. THE THREAT
FOR SEVERE WEATHER SHOULD REMAIN OFF TO OUR SOUTH WITH MODELS
INDICATING A STABLE AIRMASS OVER MUCH OF THE STATE. THE FAR SOUTH
WILL SEE THE BEST CHANCE FOR A STRAY STRONGER STORM OR
TWO...MAINLY LATE THIS AFTERNOON OR EVENING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 325 AM CDT FRI JUL 11 2014
ON SATURDAY...DEEPENING UPPER LOW SLIDES DOWN THE WESTERN SHORES OF
HUDSON BAY WHILE A FEW WAVES CONTINUE TO SWING THROUGH CYCLONIC FLOW
ALOFT THRU THE AREA. THIS WILL KEEP CHANCES FOR SHOWERS/STORMS IN
THE FORECAST PRIMARILY OVER SOUTHERN NORTH DAKOTA.
SUNDAY INTO MONDAY...AFOREMENTIONED UPPER LOW CONTINUES ITS
SOUTHERLY SLIDE TOWARDS NORTHERN MINNESOTA/LAKE SUPERIOR. MODELS
CONTINUE TO BE IN PRETTY GOOD AGREEMENT WITH THE TRACK OF THIS
SYSTEM. COOLER AIRMASS SWINGING AROUND THE LOW WILL PUSH INTO THE
AREA...WITH THE MAIN PUSH COMING LATE SUNDAY INTO MONDAY. THIS WILL
BRING WELL BELOW AVERAGE TEMPS TO THE REGION EARLY NEXT WEEK...WITH
MOST LOCATIONS SEEING HIGHS AROUND 15 TO 20 DEGREES BELOW AVERAGE ON
MONDAY. WILL HAVE TO WATCH THE TREND WITH THIS AS TEMPS MAY NEED TO
BE LOWERED EVEN FURTHER. A FEW SHOWERS WILL BE POSSIBLE ON MONDAY AS
VARIETY OF WAVES WRAP THROUGH CYCLONIC FLOW...PARTICULARLY FROM THE
TURTLE MOUNTAINS TO THE JAMES RIVER VALLEY.
FOR THE REMAINDER OF THE EXTENDED...UPPER LOW MOVES OFF TO THE EAST
WHILE RIDGE OVER THE WESTERN CONUS KEEPS NORTHWEST FLOW OVER OUR
AREA KEEPING CONDITIONS MAINLY DRY. TEMPERATURES WILL WARM THROUGH
MID-WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 609 AM CDT FRI JUL 11 2014
LCL IFR VIS IN FG OVER WRN/CNTRL ND WILL IMPROVE BY MID-MORNING.
ISOLD SHRA/-TSRA WILL CONTINUE OVER WRN ND THIS MORN...POSSIBLY
INTO THE AFTERNOON. ISOLD/SCT SHRA/-TSRA WILL BE POSSIBLE OVER SRN
ND TONIGHT. OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...NH
LONG TERM...JJS
AVIATION...JJS
AREA FORECAST DISCUSSION
NWS PORTLAND OR
241 PM PDT FRI JUL 11 2014
.SYNOPSIS...MOIST AND UNSTABLE SOUTH FLOW ALOFT WILL CONTINUE TO
SPREAD INTO THE AREA TONIGHT. THIS WILL RESULT IN THE THREAT OF
THUNDERSTORMS TO THE CASCADES AND POSSIBLY AS FAR WEST AS THE COAST
RANGE BY LATE THIS EVENING. AN UPPER LOW OFF THE NORTH CALIFORNIA
COAST SATURDAY IS EXPECTED TO MOVE NORTH TO NORTHEAST AND INLAND INTO
EXTREME SW OREGON SUNDAY FOR ANOTHER THREAT OF THUNDERSTORMS...
EXTENDING FROM THE COAST RANGE...THE VALLEYS AND TO THE CASCADES.
WELL-ABOVE NORMAL DAYTIME TEMPERATURES CAN BE EXPECTED THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TONIGHT THROUGH MONDAY...PRIMARY FORECAST CHALLENGES
REMAIN THE THUNDERSTORM POTENTIAL THROUGH TONIGHT AND AGAIN SUNDAY.
VISIBLE AND INFRA-RED SATELLITE IMAGERY SHOW MID AND HIGH-LEVEL
MOISTURE CONTINUNING TO STREAM N INTO THE AREA FROM SWRN OREGON. IR
LOOP INDICATED THE COLDEST TOPPPED CLOUDS IN DOUGLAS COUNTY AND
EXTREME SERN LANE COUNTY. LOCAL LIGHTNING DETECTION PRODUCT AS OF 20Z
NOT SHOWING ANYMORE LIGHTNING. WATER VAPOR IMAGERY SHOWS THE PRIMARY
CIRCULATION CENTER NEAR 40N 129W GRADUALLY DRIFTING NW. THERE MAY BE
A SECONDARY SUBTLE SHORT-WAVE NEAR KBOK. STILL... DEFORMATION AXIS
OVER SRN AND CENTRAL OREGON AS SEEN IN WATER VAPOR CONTINUES TO
MIGRATE NWD THIS AFTERNOON. NAM AND GFS MODEL SOUNDINGS FOR VARIOUS
LOCATIONS IN THE WILLAMETTE VALLEY NOT AT ALL IMPRESSIVE REGARDING
CONVECTION. MAIN INHIBITING FACTOR SEEMS TO BE CONVECTIVE INHIBITION
OR CIN AND THE HIGH CONVECTIVE TRIGGER TEMPS. 12Z NAM VALID 03Z SAT
SHOWED THE HIGHEST 700 MB THETA-E AIR GENEALLY S OF A FLORENCE TO
EUGENE LINE. ALSO...700 MB EAST FLOW WILL TEND TO PUSH THE BEST
DYNAMICS FURTHER AWAY FROM THE AREA. THE 18Z HRRR ALSO NOT VERY
SUPPORTIVE OF CONVECTION IN THE CWA. AT 23Z IT DEPICTS AN AREA OF
35-45 DBZ ECHOES IN CENTRAL AND WRN DOUGLAS COUNTY...BUT BY 02Z SAT
REFLECTIVITY COVERAGE QUICKLY DIMINISHES WITH JUST WEAK RETURNS OFF
THE CENTRAL COAST AND ANOTHER AREA IN ERN LANE COUNTY. WILL LEAVE
CURRENT THUNDERSTORM FORECAST FOR TONIGHT ALONE BUT WOULD NOT BE
SURPRISED IF VERY LITTLE LIGHTNING OCCURRED.
SATURDAY LOOKS TO BE AN IN-BETWEEN DAY AS A TRANSITORY 500 MB RIDGE
MOVES OVER THE AREA IN THE WAKE OF TONIGHTS SHORT-WAVE. MODEL
SOUNDINGS FOR SAT AFTERNOON...PARTICULARLY THE GFS...ARE SOMEWHAT
DRY...POSSIBLY INDICATING DECENT SUBSIDENCE BEHIND THE DEPARTING
SYSTEM...BUT MORE LIKELY THAT THE AIR MASS WILL BE SO WARM AND CAN
HOLD MUCH MORE MOISTURE THAN AN AIR MASS UNDER SEASONAL CONDITIONS.
MAIN ISSUE SATURDAY WILL BE THE RISING 850 MB TEMPS...CLIMBING TO
AROUND 22C OVER KPDX. THIS WILL BE THE START OF A MULTI-DAY HOT
SPELL. WILL ISSUE A HEAT ADVISORY FOR THIS EPISODE. HAVE KEPT ANY
THUNDERSTORM MENTION SAT TO THE CASCADES WHERE MID-LEVEL LAPSE RATES
CLOSE TO 8C/KM ARE FORECAST BY THE GFS MODEL SOUNDING.
SUNDAY LOOKS TO BE QUITE INTERESTING. ANOTHER ROUND OF MOIST SOUTH
FLOW ALOFT BEGINS TO SPREAD INTO SWRN OREGON AS EARLY AS SAT EVENING.
GFS AND ECMWF SIMILAR WITH THE OVERALL DETAILS...BUT THE 12Z NAM
APPEARS TO BE AN OUTLIER. THE 12Z ECMWF AND 12Z GFS BRING THE NEXT
LOW CENTER TO NEAR 41N 129W BY 12Z SUN. THE NAM IS A LITTLE MORE SW
WITH THE FEATURE AND MUCH SLOWER MOVING IT THROUGH THE FORECAST AREA.
UNLIKE TODAYS SYSTEM...THIS NEXT ONE IS EXPECTED TO
HAVE JET SUPPORT. GFS AND ECMWF SHOW A 60-80 KT 300 MB JET SEGMENT
MOVING INTO SWRN OREGON SUN MORNING. FORECAST AREA WILL BE IN THE
FAVORED QUADRANT OF THE JET SEGMENT FOR ADDITIONAL CONVECTIVE
SUPPORT. GFS MODEL SOUNDINGS FOR KPDX AND FOR A POINT IN THE N OREGON
CASCADES VALID SUN AFTERNOON ARE QUITE IMPRESSIVE. THE KPDX SOUNDING
VALID 00Z MON HAS A SURFACE-BASED CAPE OF NEARLY 600 J/KG...LIFTED
INDEX OF -2...TOTAL TOTALS OF 51 AND PRECIPITABLE WATER OF 1.37
INCHES. THE CASCADE SOUNDING IS EVEN MORE IMPRESSIVE WITH A CAPE OF
OVER 900 J/KG...LI OF -4...TOTAL TOTALS OF 54...0-6KM BULK SHEAR OF
NEARLY 40 KT...PRECIPITABLE WATER 1.66 INCHES...AND A SWEAT INDEX OF
311 (WE USE 250 AS THE BENCHMARK FOR POSSIBLE SEVERE). THE SREF
CALIBRATED PROBABILITY OF THUNDERSTORMS VALID 00Z-03Z MON SHOWS A 50
PERCENT BULLS-EYE OVER THE CASCADES AND THE 30 PERCENT CONTOUR TO THE
COAST. ALL IN ALL...MODELS ARE SHOWING SEVERAL INGREDIENTS COMING
TOGETHER FOR A CLASSIC PAC NW THUNDERSTORM EVENT. THUNDERSTORM
ACTIVITY SHOULD CONTINUE THROUGH SUN NIGHT...ESPECIALLY IN THE NERN
ZONES. WILL ALSO TONE DOWN SUN MAX TEMPS AS THERE SHOULD BE EXTENSIVE
CLOUD COVER DESPITE 850 MB FORECAST TEMPS OF 21-23C.
WOULD EXPECT A FLOOD OF MARINE AIR SUN NIGHT AND MON MORNING BEHIND
THE DEPARTING SHORT-WAVE. THIS WILL QUICKLY STABILIZE THINGS SUCH
THAT BY MON AFTERNOON ANY CONVECTION SHOULD BE WELL EAST OF THE AREA.
850 TEMPS 00Z TUE TO REMAIN IN THE 21-23C RANGE AND A 1000-500 MB
THICKNESS RIDGE NEAR THE OREGON COAST RANGE. WEISHAAR
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...MAIN EMPHASIS WILL BE ON
THE UNSEASONABLY HOT CONDITIONS THROUGH MUCH OF THE PERIOD. 12Z ECMWF
MAINTAINS THE HOT PATTERN THROUGH AT LEAST WED. IT DOES HINT AT THE
POSSIBILITY OF A LITTLE MARINE AIR SEEPAGE BEGINNING WEDNESDAY...BUT
MORE SO ON THURSDAY. DO NOT AGREE WITH THE GFS SOLUTION OF HAVING A
DEEP UPPER LOW SWING THROUGH LATE IN THE WEEK. 12Z ECMWF KEEPS THE
AREA IN NWLY FLOW ALOFT AND ONSHORE LOW-LEVEL FLOW...KEEPING DAYTIME
TEMPERATURES SLIGHTLY ABOVE AVERAGE. A PRIMARY CONCERN WILL BE THE
HIGH DEW POINTS...RESULTING IN UNCOMFORTABLE NIGHTTIME PERIODS.
WEISHAAR
&&
.AVIATION...MARINE STRATUS REMAINS ALONG THE COASTLINE WITH IFR
AND LOCAL LIFR CIGS AND VIS THIS AFTERNOON. SOME AREAS WILL CLEAR
TO THE COASTLINE BUT EXPECT STRATUS TO MOVE BACK IN TO THE COAST
RANGE EARLY THIS EVENING WITH EXTENSIVE IFR AND LIFR TONIGHT. NOT
MUCH CHANGE FOR TOMORROW ALONG THE COAST. INLAND AREAS WILL REMAIN
VFR WITH THE MAIN THREAT BEING THE MID LEVEL MOISTURE MOVING UP FROM
THE SOUTH ASSOCIATED WITH THE DISTURBANCE ALOFT OVER SOUTHERN
OREGON. CIGS WILL BE 8000 TO 12000 FEET TONIGHT WITH SOME ISOLATED
SHOWERS MOSTLY ALOFT DURING THE EVENING IN THE SOUTH SPREADING
NORTH. THERE IS A SLIGHT CHANCE OF ELEVATED THUNDERSTORMS FROM
KSXT TO KCVO 23Z-04Z...INCLUDING THE ADJACENT COAST RANGE AND
CASCADES. THERE REMAINS A POSSIBILITY OF SOME ELEVATED
THUNDERSTORMS SPREADING NORTH KCVO-KPDX DURING THE EVENING 03Z-
09Z. SCHNEIDER
KPDX AND APPROACHES...VFR TODAY AND TONIGHT. THERE WILL BE A 15
PERCENT CHANCE OF A THUNDERSTORM AFTER 03Z AND LIKELY A LOT OF MID
LEVEL CLOUDS WITH A FEW SHOWERS MOSTLY ALOFT FROM 03Z-09Z AS DEBRIS
FROM STORMS ELSEWHERE MOVES OVER THE AREA. STRATUS IS NOT EXPECTED
TO REACH THE TERMINAL SATURDAY MORNING. SCHNEIDER
&&
.MARINE...HIGH PRES WILL REMAIN OVER THE NE PAC THROUGH THE
WEEKEND...KEEPING WINDS FROM THE N TO NW. THE GRADIENTS WILL
CONTINUE TO BE WEAK FOR LIGHTER WINDS TONIGHT THROUGH SATURDAY
NIGHT. THE OFFSHORE HIGH AND THE INLAND THERMAL LOW WILL
STRENGTHEN SUNDAY FOR INCREASING NORTHWEST WINDS BY AFTERNOON AND
LIKELY REACH SMALL CRAFT ADVISORY LEVELS...THEN REMAIN BRISK INTO
THE MIDDLE OF NEXT WEEK.
SEAS CONTINUE TO FALL TONIGHT AND SATURDAY. BY SATURDAY AFTERNOON
THE NORTHWEST FRESH SWELL ABATES UNDER LIGHT WINDS AND THE ENP
MODEL INDICATES WE WILL START TO SEE A LONG PERIOD WEST SWELL OF 2
TO 3 FT. THIS WOULD NORMALLY BE MASKED BY THE NORTHWEST WIND
SEAS. ALL IN ALL THE SEAS WILL REMAIN BELOW 5 FT UNTIL THE
NORTHWESTERLY INCREASE SUNDAY AFTERNOON. THE COLUMBIA BAR WILL
SEE A VERY STRONG EBB EARLY SATURDAY MORNING BUT WITH RELATIVELY
LIGHT INCOMING SWELL WAVES WILL REMAIN BELOW SMALL CRAFT
LEVELS...STILL MARINERS SHOULD BE CAUTIOUS CROSS THE BARS DURING
THIS VERY STRONG EBB. SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HEAT ADVISORY FROM 5 AM SATURDAY TO 2 PM PDT TUESDAY FOR
CASCADE FOOTHILLS IN LANE COUNTY-CASCADES IN LANE
COUNTY-CENTRAL COAST RANGE OF WESTERN OREGON-CENTRAL COLUMBIA
RIVER GORGE-CENTRAL WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST
OREGON-GREATER PORTLAND METRO AREA-LOWER COLUMBIA-NORTHERN
OREGON CASCADE FOOTHILLS-NORTHERN OREGON CASCADES-SOUTH
WILLAMETTE VALLEY-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA
RIVER GORGE.
WA...HEAT ADVISORY FROM 5 AM SATURDAY TO 2 PM PDT TUESDAY FOR
CENTRAL COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-I-5
CORRIDOR IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE
FOOTHILLS-SOUTH WASHINGTON CASCADES-WESTERN COLUMBIA RIVER
GORGE-WILLAPA HILLS.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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
NWS PORTLAND OR
942 AM PDT FRI JUL 11 2014
.SYNOPSIS...MOIST AND UNSTABLE SOUTH FLOW ALOFT WILL SPREAD INTO THE
AREA TODAY AND TONIGHT. THIS BRINGS THE THREAT OF THUNDERSTORMS TO
THE CASCADES AND POSSIBLY AS FAR WEST AS THE COAST RANGE BY LATER
THIS EVENING. AN UPPER LOW OFF THE NORTH CALIFORNIA COAST SATURDAY IS
EXPECTED TO MOVE NORTH TO NORTHEAST AND INLAND INTO EXTREME SW OREGON
SUNDAY FOR ANOTHER THREAT OF THUNDERSTORMS...EXTENDING FROM THE COAST
RANGE...THE VALLEYS AND TO THE CASCADES. WELL-ABOVE NORMAL DAYTIME
TEMPERATURES CAN BE EXPECTED FRIDAY THROUGH THE MIDDLE OF NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH SUNDAY...PRIMARY FORECAST CHALLENGES WILL
BE THUNDERSTORM POTENTIAL THIS AFTERNOON THROUGH TONIGHT AND AGAIN
SUNDAY. MORNING VISIBLE SATELLITE IMAGERY SHOWS THE MARINE STRATUS
CONFINED TO THE COAST AND MAJOR COASTAL RIVER DRAINAGES AND ALONG THE
COLUMBIA RIVER TO NEAR KPDX. MID AND HIGH LEVEL CLOUDS SPREADING
NORTH INTO SRN DOUGLAS COUNTY ASSOCIATED WITH AN UPPER LEVEL
DISTURBANCE NEAR 40N 129W. WATER VAPOR IMAGERY SHOWS SELY DIFFLUENT
FLOW ALOFT INTO SWRN OREGON THIS MORNING. ALTHOUGH THE ACTUAL LOW
CENTER IS WELL OFF THE COAST...THE DIFFLUENT FLOW AND ASSOCIATED
DEFORMATION AREA HAS ALLOWED THE AIR MASS TO BECOME MORE MOIST.
MAIN CONCERN TODAY CONTINUES TO BE THE CONVECTIVE THREAT. AREAS SOUTH
OF AN ALBANY-NEWPORT LINE STAND THE BEST CHANCE OF THUNDERSTORMS.
LATEST NAM MODEL RUN SHOWS A VORTICITY LOBE ROTATING INTO THE FAR S
PART OF THE FORECAST AREA MID TO LATE AFTERNOON. HIGHEST 700 MB THETA
E AIR OFF THE NAM VALID 21Z IS CONFINED TO AREAS SOUTH OF SRN LANE
COUNTY. AM A LITTLE CONCERNED THAT THE BEST DYNAMICS WILL BE PUSHED
TO THE CENTRAL OREGON COASTLINE BY LATE AFTERNOON AND EARLY EVENING
DUE TO EAST 700 MB FLOW...THUS REDUCING THE CONVECTIVE THREAT FURTHER
NORTH. THE 10Z HRRR RUN SHOWS THE LEADING EDGE OF THE 30 DBZ
REFLECTIVITY SHIELD TO BE IN CENTRAL LANE COUNTY AT 00Z SAT. OPTED TO
MENTION SLIGHT CHANCE OF TS FURTHER WEST IN THE CENTRAL OREGON COAST
RANGE THIS AFTERNOON AND INTO ALL OF THE COAST RANGE 00Z-06Z SAT. NAM
AND NAMM MODEL SOUNDINGS FOR KEUG VIA BUFKIT NOT ALL THAT IMPRESSIVE
FOR CONVECTION. AT 02Z NAMM MODEL SOUNDING SHOWING MINIMAL
SURFACE-BASED CONVECTIVE AVAILABLE POTENTIAL ENERGY (CAPE) WITH OVER
300 J/KG CONVECTION INHIBITION (CIN) TO OVERCOME. HOWEVER...LIFTED
INDICES LOWER TO NEAR 0 WITH MODEL PRECIPITABLE WATER UP TO 1.3
INCHES. THIS SHORT-WAVE DOES NOT APPEAR TO HAVE MUCH...IF ANY...JET
SUPPORT. FEEL THAT OVERALL CONVECTIVE THREAT WILL WANE PRETTY QUICKLY
AFTER 06Z AS THE MAIN CIRCULATION CENTER CONTINUES TO DRIFT NW-N.
SATURDAY LOOKS TO BE AN IN-BETWEEN DAY AS A TRANSITORY 500 MB RIDGE
MOVES OVER THE AREA IN THE WAKE OF TONIGHTS SHORT-WAVE. MODEL
SOUNDINGS FOR SAT AFTERNOON...PARTICULARLY THE GFS...ARE SOMEWHAT
DRY...POSSIBLY INDICATING DECENT SUBSIDENCE BEHIND THE DEPARTING
SYSTEM...BUT MORE LIKELY THAT THE AIR MASS WILL BE SO WARM AND CAN
HOLD MUCH MORE MOISTURE THAN AN AIR MASS UNDER SEASONAL CONDITIONS.
MAIN ISSUE SATURDAY WILL BE THE RISING 850 MB TEMPS...CLIMBING TO
AROUND 22C OVER KPDX. THIS WILL BE THE START OF A MULTI-DAY HOT
SPELL. KEPT ANY THUNDERSTORM MENTION SAT TO THE CASCADES WHERE
MID-LEVEL LAPSE RATES CLOSE TO 8C/KM ARE FORECAST BY THE GFS MODEL
SOUNDING.
SUNDAY CONTINUES TO LOOK MORE AND MORE INTERESTING. ANOTHER ROUND OF
MOIST SOUTH FLOW ALOFT BEGINS TO SPREAD INTO SWRN OREGON AS EARLY AS
SAT EVENING. MODELS STARTING TO CONVERGE ON A GENERAL SOLUTION. THE
12Z NAM...00Z ECMWF AND 06Z GFS BRING THE NEXT LOW CENTER TO NEAR 41N
129W BY 12Z SUN. UNLIKE TODAYS SYSTEM...THIS NEXT ONE IS EXPECTED TO
HAVE JET SUPPORT. NAM AND ECMWF SHOW A 60-80 KT 300 MB JET SEGMENT
MOVING INTO SWRN OREGON SUN MORNING. FORECAST AREA WILL BE IN THE
FAVORED QUADRANT OF THE JET SEGMENT FOR ADDITIONAL CONVECTIVE
SUPPORT. NAM MODEL SOUNDINGS FOR KPDX VALID SUN AFTERNOON ARE QUITE
IMPRESSIVE. BY 23Z THE MODEL SOUNDING SHOWS OVER 1500 J/KG CAPE...LI
OF -3 AND AN EQUILIBRIUM LEVEL IN EXCESS OF 37000 FEET. STORM
PREDICTION CENTER (SPC) EVEN MENTIONS THE POSSIBILITY OF A FEW STORMS
APPROACHING SEVERE LIMITS. NAM MODEL SOUNDINGS FOR THE CASCADES ARE
EVEN MORE IMPRESSIVE...WITH TOTAL TOTALS IN EXCESS OF 50...SWEAT
INDEX OVER 250 (THE NORMAL BENCHMARK WE USE FOR POSSIBLE SEVERE
WEATHER) AND 0-6KM BULK SHEAR VALUES OF 30-35 KTS. THUNDERSTORM
ACTIVITY SHOULD CONTINUE THROUGH SUN NIGHT...ESPECIALLY IN THE NERN
ZONES. WILL ALSO TONE DOWN SUN MAX TEMPS AS THERE SHOULD BE EXTENSIVE
CLOUD COVER DESPITE 850 MB FORECAST TEMPS OF 21-23C. WEISHAAR
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY...MAIN EMPHASIS WILL BE ON
THE UNSEASONABLY HOT CONDITIONS THROUGH MUCH OF THE PERIOD. LATEST
GFS HAS COME AROUND TO THE 00Z ECMWF IDEA OF A NOT SO OMINOUS HEAT
WAVE. STILL...EXPECT INLAND MAX TEMPS IN THE 90S MON THROUGH AT LEAST
WED. 00Z FRI MEX GUIDANCE GIVES KPDX A MAX OF 95 MON AND
TUE...INSTEAD OF THE 100 IT SHOWED YESTERDAY. THE BIGGER CONCERN WILL
BE THE HIGH DEW POINTS...RESULTING IN UNCOMFORTABLE NIGHTTIME
PERIODS. HOT SPELLS BEYOND 3-4 DAYS ARE RARE. WILL BE LIKELY GOING
WITH AN EXCESSIVE HEAT ADVISORY SAT-WED FOR THE AFTERNOON FORECAST
PACKAGE. THERE MAY BE SLIGHT RELIEF BEGINNING AROUND WED...BUT MAX
TEMPS WILL REMAIN SEVERAL DEGREES ABOVE NORMAL. WEISHAAR
&&
.AVIATION...MARINE INVERSION ABOUT 2000 FEET DEEP ALONG THE COAST
THIS MORNING WITH LIGHT NW FLOW KEEPING THE IFR AND LIFR STRATUS
PACKED INTO THE BASES OF THE COAST RANGE. EXPECT A LATE BREAKOUT
IN MOST COASTAL AREAS 20-23Z AND THEN IFR CONDITIONS RETURNING
AFTER ABOUT 03Z. INLAND THERE HAS BEEN STRATUS THAT MOVED DOWN THE
COLUMBIA RIVER TO KPDX THIS MORNING BUT THIS WILL DISSIPATE
RAPIDLY. A WEATHER DISTURBANCE IS ROTATING UP AROUND A LOW
OFFSHORE AND WILL MOVE ACROSS THE AREA THIS AFTERNOON AND TONIGHT.
THIS WILL RESULT IN MID AND LEVEL MOISTURE INCREASE AND SCATTERED
THUNDERSTORMS OVER THE MOUNTAINS. THE 700MB FLOW BECOMES SOUTH
THIS AFTERNOON AND THEN SOUTHEAST DURING THE EVENING AND EXPECT A
FEW THUNDERSTORMS WILL DRIFT OUT OVER THE WILLAMETTE VALLEY. THE
HIGHER THREAT IS IN THE SOUTHERN WILLAMETTE VALLEY. EXPECT
THUNDERSTORMS TO BE RELATIVELY HIGH BASED. SCHNEIDER
KPDX AND APPROACHES...VFR TODAY AND TONIGHT. THERE WILL BE A 15
PERCENT CHANCE OF A THUNDERSTORM AFTER 00Z AND LIKELY A LOT OF MID
LEVEL CLOUDS FROM 03Z-09Z AS DEBRIS FROM STORMS ELSEWHERE MOVES OVER
THE AREA. SCHNEIDER
&&
.MARINE...HIGH PRES WILL REMAIN OVER THE NE PAC THROUGH THE
WEEKEND...KEEPING WINDS FROM THE N TO NW. THE GRADIENTS WILL BE
WEAKER TODAY AND SATURDAY FOR WEAKER WINDS THAN THE LAST COUPLE OF
DAYS. THE MODELS INDICATE THE NORTH TO NORTHWEST WINDS WILL THEN
STRENGTHEN SUNDAY AND POSSIBLY REACH SMALL CRAFT ADVISORY
LEVELS...THEN REMAIN BRISK INTO THE MIDDLE OF NEXT WEEK.
SEAS ARE NOW FALLING...CURRENTLY AT AROUND 6 FT AND WILL CONTINUE
TO FALL TODAY. THIS WILL ALSO REDUCE THE WAVES ON THE COLUMBIA
RIVER BAR...BUT THERE IS A VERY STRONG EBB TOMORROW MORNING AND
THAT WILL RESULT IN BREAKERS. CONDITIONS SHOULD STAY JUST BELOW
SMALL CRAFT ADVISORY CATEGORY BUT BOATERS SHOULD REMAIN CAUTIOUS
DURING THE EBB. SEAS WILL LIKELY BUILD AGAIN IN THE INCREASING
NORTHWEST WINDS LATER SUNDAY AND MONDAY. SCHNEIDER
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT... HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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
NWS MEDFORD OR
920 AM PDT FRI JUL 11 2014
.DISCUSSION...THE FIRST ROUND OF CONVECTION IS MOVING THROUGH THE
REGION THIS MORNING AS A STRONG SHORT WAVES CYCLES THROUGH FROM THE
SOUTH. WITH THE INCREASED CLOUD COVER HAVE LOWERED HIGH TEMPERATURES
FOR TODAY. THERE ARE SEVERAL MORE SHORT WAVES THAT WILL MOVE THROUGH
AND THE BIGGEST CONCERN WILL BE HOW MUCH INSTABILITY IS MAXED OUT
WITH THE FIRST LINE OF CONVECTION AND ITS EFFECTS ON LATER
THUNDERSTORM DEVELOPMENT. WILL STICK WITH THE CURRENT FORECAST ON
THE THUNDERSTORMS AT THIS TIME. SVEN
PREVIOUS DISCUSSION...VERY WARM TEMPERATURES WILL CONTINUE INTO THE
WEEKEND AS THE UPPER LEVEL RIDGE WILL ONLY WEAKEN TEMPORARILY. A
LOW PRESSURE TROUGH APPROACHING NORTHERN CALIFORNIA COAST THIS
MORNING WILL SEND A BAND OF MOISTURE INTO OUR FORECAST AREA ALONG
WITH AREAS OF INSTABILITY. SO FAR THERE HAVE BEEN CLOUD TO CLOUD
LIGHTNING STRIKES JUST SOUTH OF SISKIYOU COUNTY OVERNIGHT.
MOISTURE IS EXPECTED TO SPREAD INTO EASTERN SISKIYOU COUNTY MAINLY
FROM THE CASCADES EASTWARD AROUND DAY BREAK. THE NAM12 TAKES MOST
OF THIS MOISTURE NORTH ALONG AND JUST EAST OF THE CASCADES WITH
ANOTHER BAND OF MOISTURE ROTATING BACK ACROSS SW OREGON. THE SHORT
TERM HRRR MODEL SHOWS A SIMILAR TRACK ON FORECAST RADAR RETURN BUT
SHOWS A MODERATE RETURN (30-40DBZ) EXPANDING BACK INTO NW JACKSON
COUNTY AND EASTERN DOUGLAS COUNTY INTO FIRE ZONE 617 BY THIS
AFTERNOON. THE NAM12 SHOWS MORE INSTABILITY FURTHER WEST INTO
JOSEPHINE AND JACKSON COUNTY WHERES THE GFS KEEPS NEGATIVE LIFTED
INDEX MAINLY NEAR THE CASCADES WHILE ERODING ANY CAPPING BY MID
MORNING. MY FEELING ON THIS IS THAT WE MAY SEE TWO DISTINCT BAND
OF CONVECTION, ONE TRAVELLING NORTH INTO THE KLAMATH BASIN AND THE
OTHER COMING UP THROUGH THE HAPPY CAMP DISTRICT INTO THE ILLINOIS
VALLEY AND THEN NORTHWARD INTO THE UMPQUA BASIN. CURRENT RED FLAG
WARNING COVERS THIS TREND AND WILL KEEP AREAL COVERAGE AS IS. BOTH
MODELS SHOW CLEARING ACROSS THE WEST SIDE THIS AFTERNOON AND THIS
MAY BE CONDUCIVE TO THE SECOND ROUND OF CONVECTION FROM SURFACE
HEATING.
FOR SATURDAY..THERE WILL BE MORE H7-H5 MOISTURE EAST OF THE
CASCADES AND THIS IS WHERE MOST CONVECTION WILL BE LOCATED. THE
AIR MASS WILL BE MUCH DRIER WEST OF THE CASCADES. HAVE KEPT ALL OF
THUNDERSTORMS FORECAST TO THE EAST OF THE CASCADES.
ON SUNDAY..ANOTHER ROUND OF TROUGH WILL APPROACH THE COAST AGAIN.
ONE THING THAT MAKES THIS TROUGH DIFFERENT IS THE PRESENCE OF 75KT
JETMAX MOVING INTO NW CALIFORNIA AND SW OREGON. IN ADDITION BOTH
MODELS INDICATE ENOUGH MOISTURE TO GENERATE THUNDERSTORMS. /FB
&&
.AVIATION...BASED ON THE 11/06Z TAFS...IFR CONDITIONS
ARE PRESENT ALONG THE COAST AND ARE EXPECTED TO PERSIST THROUGH
EARLY THIS MORNING...WITH CLEARING IN THE LATE FRIDAY MORNING.
ELSEWHERE...EXPECT MAINLY VFR CONDITIONS EARLY THIS MORNING THEN AS
THUNDERSTORMS DEVELOP MAY SEE LOCAL MVFR CIGS DEVELOP DURING THE DAY
WITH A RETURN TO VFR DURING THE EVENING. THUNDERSTORMS WILL HAVE
THE LARGEST IMPACT ON INLAND AREAS TODAY. THUNDERSTORMS WILL AFFECT
NORTHERN CALIFORNIA FIRST EARLY THIS MORNING...AND THEN SPREAD INTO
SOUTHERN OREGON DURING THE MORNING AND CONTINUING INTO THE
AFTERNOON. GREATEST COVERAGE OF THUNDERSTORMS EXPECTED
LATE IN THE MORNING INTO THE AFTERNOON. VERY GUSTY WINDS AND HAIL
ARE EXPECTED WITH SOME OF THESE STORMS. /CC
&&
.MARINE...UPDATED THURSDAY 11 JULY 300 AM PDT...WINDS HAVE
WEAKENED CONSIDERABLY...AND SEAS WILL GRADUALLY DIMINISH THROUGH
TODAY. SEAS ARE COMING DOWN A BIT SLOWER THAN PREVIOUSLY
FORECAST...SO HAVE EXTENDED THE SMALL CRAFT ADVISORY OUT A FEW MORE
HOURS. A WEAK LOW PRESSURE WILL MOVE THROUGH THE WATERS TODAY INTO
TOMORROW...BUT WINDS WILL REMAIN GENERALLY LIGHT UNTIL SUNDAY
AFTERNOON. THE THERMAL TROUGH PATTERN WILL REDEVELOP SUNDAY AND
STRENGTHEN MONDAY...RESULTING IN ANOTHER ROUND OF MODERATE TO
STRONG NORTH WINDS AND BUILDING SHORT PERIOD SEAS. -BPN
&&
.FIRE WEATHER...SATELLITE AND RADAR IMAGERY TO THE SOUTH SHOW SOME
CONVECTION HAS BEGUN IN ASSOCIATION WITH A SHORT WAVE AND MONSOONAL
MOISTURE THAT WILL BE MOVING INTO OUR AREA LATER THIS MORNING
THROUGH THIS AFTERNOON. SOME CLOUD-TO-CLOUD LIGHTNING HAS ALSO BEEN
DEPICTED WITH THESE BUILDUPS...SUGGESTING THAT A GOOD DEAL OF
INSTABILITY EXISTS OVER THE AREA THIS MORNING EVEN BEFORE SOLAR
HEATING BEGINS. MUCH DEPENDS ON THE TIMING OF THE SHORTWAVE AND THE
ARRIVAL OF MOISTURE...AS WELL AS WHAT AREAS RECEIVE THE MOST
HEATING...AND THE EXACT LOCATION OF JET ENERGY OVERHEAD WHICH COULD
LEND TO MORE NUMEROUS CELLS. STEERING WINDS ARE EXPECTED TO BE FROM
THE SOUTH AND SOUTHEAST WHICH IS A FAVORABLE FLOW TO GET STORMS TO
SPREAD OUT OVER THE VALLEYS WEST OF THE CASCADES. GIVEN THE DRY
FUELS AND EXPECTED NUMEROUS LIGHTNING STRIKES EXPECTED...HAVE
CONTINUED RED FLAG WARNINGS FOR NORTHERN CAL AND MOST OF OREGON
ZONES. THE EXCEPTION WILL BE THE COASTAL ZONES...WHERE THE
ATMOSPHERE SHOULD REMAIN MUCH MORE STABLE. EVEN THEN...CAN NOT RULE
OUT ISOLATED THUNDERSTORMS FOR FIRE ZONES 615 AND 618. MODELS
SUGGEST THE BULK OF THE ACTION WILL SHIFT NORTH DURING THE DAY TODAY
AND COULD BE OUT OF THE AREA BY THIS AFTERNOON...BUT AGAIN MUCH
DEPENDS ON THE TIMING. ANOTHER UPPER LOW WILL MOVE TOWARDS THE AREA
SUNDAY, BUT THE MODELS SUGGEST MOST OF THE INSTABILITY AND
THUNDERSTORM POTENTIAL WILL BE FROM AROUND CRATER LAKE NORTH. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR ORZ624-625.
RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR
ORZ616-617-619>623.
CA...RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR
CAZ280>282-284-285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS
UNTIL 11 AM PDT THIS
MORNING FOR PZZ350-356-370-376.
$$
FJB/FJB/CC
AREA FORECAST DISCUSSION...CORRECTED
NWS MEDFORD OR
507 AM PDT FRI JUL 11 2014
.DISCUSSION...VERY WARM TEMPERATURES WILL CONTINUE INTO THE
WEEKEND AS THE UPPER LEVEL RIDGE WILL ONLY WEAKEN TEMPORARILY. A
LOW PRESSURE TROUGH APPROACHING NORTHERN CALIFORNIA COAST THIS
MORNING WILL SEND A BAND OF MOISTURE INTO OUR FORECAST AREA ALONG
WITH AREAS OF INSTABILITY. SO FAR THERE HAVE BEEN CLOUD TO CLOUD
LIGHTNING STRIKES JUST SOUTH OF SISKIYOU COUNTY OVERNIGHT.
MOISTURE IS EXPECTED TO SPREAD INTO EASTERN SISKIYOU COUNTY MAINLY
FROM THE CASCADES EASTWARD AROUND DAY BREAK. THE NAM12 TAKES MOST
OF THIS MOISTURE NORTH ALONG AND JUST EAST OF THE CASCADES WITH
ANOTHER BAND OF MOISTURE ROTATING BACK ACROSS SW OREGON. THE SHORT
TERM HRRR MODEL SHOWS A SIMILAR TRACK ON FORECAST RADAR RETURN BUT
SHOWS A MODERATE RETURN (30-40DBZ) EXPANDING BACK INTO NW JACKSON
COUNTY AND EASTERN DOUGLAS COUNTY INTO FIRE ZONE 617 BY THIS
AFTERNOON. THE NAM12 SHOWS MORE INSTABILITY FURTHER WEST INTO
JOSEPHINE AND JACKSON COUNTY WHERES THE GFS KEEPS NEGATIVE LIFTED
INDEX MAINLY NEAR THE CASCADES WHILE ERODING ANY CAPPING BY MID
MORNING. MY FEELING ON THIS IS THAT WE MAY SEE TWO DISTINCT BAND
OF CONVECTION, ONE TRAVELLING NORTH INTO THE KLAMATH BASIN AND THE
OTHER COMING UP THROUGH THE HAPPY CAMP DISTRICT INTO THE ILLINOIS
VALLEY AND THEN NORTHWARD INTO THE UMPQUA BASIN. CURRENT RED FLAG
WARNING COVERS THIS TREND AND WILL KEEP AREAL COVERAGE AS IS. BOTH
MODELS SHOW CLEARING ACROSS THE WEST SIDE THIS AFTERNOON AND THIS
MAY BE CONDUCIVE TO THE SECOND ROUND OF CONVECTION FROM SURFACE
HEATING.
FOR SATURDAY..THERE WILL BE MORE H7-H5 MOISTURE EAST OF THE
CASCADES AND THIS IS WHERE MOST CONVECTION WILL BE LOCATED. THE
AIR MASS WILL BE MUCH DRIER WEST OF THE CASCADES. HAVE KEPT ALL OF
THUNDERSTORMS FORECAST TO THE EAST OF THE CASCADES.
ON SUNDAY..ANOTHER ROUND OF TROUGH WILL APPROACH THE COAST AGAIN.
ONE THING THAT MAKES THIS TROUGH DIFFERENT IS THE PRESENCE OF 75KT
JETMAX MOVING INTO NW CALIFORNIA AND SW OREGON. IN ADDITION BOTH
MODELS INDICATE ENOUGH MOISTURE TO GENERATE THUNDERSTORMS. /FB
&&
.AVIATION...BASED ON THE 11/06Z TAFS...IFR CONDITIONS
ARE PRESENT ALONG THE COAST AND ARE EXPECTED TO PERSIST THROUGH
EARLY THIS MORNING...WITH CLEARING IN THE LATE FRIDAY MORNING.
ELSEWHERE...EXPECT MAINLY VFR CONDITIONS EARLY THIS MORNING THEN AS
THUNDERSTORMS DEVELOP MAY SEE LOCAL MVFR CIGS DEVELOP DURING THE DAY
WITH A RETURN TO VFR DURING THE EVENING. THUNDERSTORMS WILL HAVE
THE LARGEST IMPACT ON INLAND AREAS TODAY. THUNDERSTORMS WILL AFFECT
NORTHERN CALIFORNIA FIRST EARLY THIS MORNING...AND THEN SPREAD INTO
SOUTHERN OREGON DURING THE MORNING AND CONTINUING INTO THE
AFTERNOON. GREATEST COVERAGE OF THUNDERSTORMS EXPECTED
LATE IN THE MORNING INTO THE AFTERNOON. VERY GUSTY WINDS AND HAIL
ARE EXPECTED WITH SOME OF THESE STORMS. /CC
&&
.MARINE...UPDATED THURSDAY 11 JULY 300 AM PDT...WINDS HAVE
WEAKENED CONSIDERABLY...AND SEAS WILL GRADUALLY DIMINISH THROUGH
TODAY. SEAS ARE COMING DOWN A BIT SLOWER THAN PREVIOUSLY
FORECAST...SO HAVE EXTENDED THE SMALL CRAFT ADVISORY OUT A FEW MORE
HOURS. A WEAK LOW PRESSURE WILL MOVE THROUGH THE WATERS TODAY INTO
TOMORROW...BUT WINDS WILL REMAIN GENERALLY LIGHT UNTIL SUNDAY
AFTERNOON. THE THERMAL TROUGH PATTERN WILL REDEVELOP SUNDAY AND
STRENGTHEN MONDAY...RESULTING IN ANOTHER ROUND OF MODERATE TO
STRONG NORTH WINDS AND BUILDING SHORT PERIOD SEAS. -BPN
&&
.FIRE WEATHER...SATELLITE AND RADAR IMAGERY TO THE SOUTH SHOW SOME
CONVECTION HAS BEGUN IN ASSOCIATION WITH A SHORT WAVE AND MONSOONAL
MOISTURE THAT WILL BE MOVING INTO OUR AREA LATER THIS MORNING
THROUGH THIS AFTERNOON. SOME CLOUD-TO-CLOUD LIGHTNING HAS ALSO BEEN
DEPICTED WITH THESE BUILDUPS...SUGGESTING THAT A GOOD DEAL OF
INSTABILITY EXISTS OVER THE AREA THIS MORNING EVEN BEFORE SOLAR
HEATING BEGINS. MUCH DEPENDS ON THE TIMING OF THE SHORTWAVE AND THE
ARRIVAL OF MOISTURE...AS WELL AS WHAT AREAS RECEIVE THE MOST
HEATING...AND THE EXACT LOCATION OF JET ENERGY OVERHEAD WHICH COULD
LEND TO MORE NUMEROUS CELLS. STEERING WINDS ARE EXPECTED TO BE FROM
THE SOUTH AND SOUTHEAST WHICH IS A FAVORABLE FLOW TO GET STORMS TO
SPREAD OUT OVER THE VALLEYS WEST OF THE CASCADES. GIVEN THE DRY
FUELS AND EXPECTED NUMEROUS LIGHTNING STRIKES EXPECTED...HAVE
CONTINUED RED FLAG WARNINGS FOR NORTHERN CAL AND MOST OF OREGON
ZONES. THE EXCEPTION WILL BE THE COASTAL ZONES...WHERE THE
ATMOSPHERE SHOULD REMAIN MUCH MORE STABLE. EVEN THEN...CAN NOT RULE
OUT ISOLATED THUNDERSTORMS FOR FIRE ZONES 615 AND 618. MODELS
SUGGEST THE BULK OF THE ACTION WILL SHIFT NORTH DURING THE DAY TODAY
AND COULD BE OUT OF THE AREA BY THIS AFTERNOON...BUT AGAIN MUCH
DEPENDS ON THE TIMING. ANOTHER UPPER LOW WILL MOVE TOWARDS THE AREA
SUNDAY, BUT THE MODELS SUGGEST MOST OF THE INSTABILITY AND
THUNDERSTORM POTENTIAL WILL BE FROM AROUND CRATER LAKE NORTH. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR ORZ624-625.
RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR
ORZ616-617-619>623.
CA...RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR
CAZ280>282-284-285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THIS
MORNING FOR PZZ350-356-370-376.
$$
FJB/FJB/CC
AREA FORECAST DISCUSSION
NWS MEDFORD OR
339 AM PDT FRI JUL 11 2014
.DISCUSSION...VERY WARM TEMPERATURES WILL CONTINUE INTO THE
WEEKEND AS THE UPPER LEVEL RIDGE WILL ONLY WEAKEN BUT NOT BROKEN.
A LOW PRESSURE TROUGH APPROACHING NORTHERN CALIFORNIA COAST THIS
MORNING WILL SEND A BAND OF MOISTURE INTO OUR FORECAST AREA ALONG
WITH AREAS OF INSTABILITY. SO FAR THERE HAVE BEEN CLOUD TO CLOUD
LIGHTNING STRIKES JUST SOUTH OF SISKIYOU COUNTY OVERNIGHT.
MOISTURE IS EXPECTED TO SPREAD INTO EASTERN SISKIYOU COUNTY MAINLY
FROM THE CASCADES EASTWARD AROUND DAY BREAK. THE NAM12 TAKES MOST
OF THIS MOISTURE NORTH ALONG AND JUST EAST OF THE CASCADES WITH
ANOTHER BAND OF MOISTURE ROTATING BACK ACROSS SW OREGON. THE SHORT
TERM HRRR MODEL SHOWS A SIMILAR TRACK ON FORECAST RADAR RETURN BUT
SHOWS A MODERATE RETURN (30-40DBZ) EXPANDING BACK INTO NW JACKSON
COUNTY AND EASTERN DOUGLAS COUNTY INTO FIRE ZONE 617 BY THIS
AFTERNOON. THE NAM12 SHOWS MORE INSTABILITY FURTHER WEST INTO
JOSEPHINE AND JACKSON COUNTY WHERES THE GFS KEEPS NEGATIVE LIFTED
INDEX MAINLY NEAR THE CASCADES WHILE ERODING ANY CAPPING BY MID
MORNING. MY FEELING ON THIS IS THAT WE MAY SEE TWO DISTINCT BAND
OF CONVECTION, ONE TRAVELLING NORTH INTO THE KLAMATH BASIN AND THE
OTHER COMING UP THROUGH THE HAPPY CAMP DISTRICT INTO THE ILLINOIS
VALLEY AND THEN NORTHWARD INTO THE UMPQUA BASIN. CURRENT RED FLAG
WARNING COVERS THIS TREND AND WILL KEEP AREAL COVERAGE AS IS. BOTH
MODELS SHOW CLEARING ACROSS THE WEST SIDE THIS AFTERNOON AND THIS
MAY BE CONDUCIVE TO THE SECOND ROUND OF CONVECTION FROM SURFACE
HEATING.
FOR SATURDAY..THERE WILL BE MORE H7-H5 MOISTURE EAST OF THE
CASCADES AND THIS IS WHERE MOST CONVECTION WILL BE LOCATED. THE
AIR MASS WILL BE MUCH DRIER WEST OF THE CASCADES. HAVE KEPT ALL OF
THUNDERSTORMS FORECAST TO THE EAST OF THE CASCADES.
ON SUNDAY..ANOTHER ROUND OF TROUGH WILL APPROACH THE COAST AGAIN.
ONE THING THAT MAKES THIS TROUGH DIFFERENT IS THE PRESENCE OF 75KT
JETMAX MOVING INTO NW CALIFORNIA AND SW OREGON. IN ADDITION BOTH
MODELS INDICATE ENOUGH MOISTURE TO GENERATE THUNDERSTORMS. /FB
&&
.AVIATION...BASED ON THE 11/06Z TAFS...IFR CONDITIONS
ARE PRESENT ALONG THE COAST AND ARE EXPECTED TO PERSIST THROUGH
EARLY THIS MORNING...WITH CLEARING IN THE LATE FRIDAY MORNING.
ELSEWHERE...EXPECT MAINLY VFR CONDITIONS EARLY THIS MORNING THEN AS
THUNDERSTORMS DEVELOP MAY SEE LOCAL MVFR CIGS DEVELOP DURING THE DAY
WITH A RETURN TO VFR DURING THE EVENING. THUNDERSTORMS WILL HAVE
THE LARGEST IMPACT ON INLAND AREAS TODAY. THUNDERSTORMS WILL AFFECT
NORTHERN CALIFORNIA FIRST EARLY THIS MORNING...AND THEN SPREAD INTO
SOUTHERN OREGON DURING THE MORNING AND CONTINUING INTO THE
AFTERNOON. GREATEST COVERAGE OF THUNDERSTORMS EXPECTED
LATE IN THE MORNING INTO THE AFTERNOON. VERY GUSTY WINDS AND HAIL
ARE EXPECTED WITH SOME OF THESE STORMS. /CC
&&
.MARINE...UPDATED THURSDAY 11 JULY 300 AM PDT...WINDS HAVE
WEAKENED CONSIDERABLY...AND SEAS WILL GRADUALLY DIMINISH THROUGH
TODAY. SEAS ARE COMING DOWN A BIT SLOWER THAN PREVIOUSLY
FORECAST...SO HAVE EXTENDED THE SMALL CRAFT ADVISORY OUT A FEW MORE
HOURS. A WEAK LOW PRESSURE WILL MOVE THROUGH THE WATERS TODAY INTO
TOMORROW...BUT WINDS WILL REMAIN GENERALLY LIGHT UNTIL SUNDAY
AFTERNOON. THE THERMAL TROUGH PATTERN WILL REDEVELOP SUNDAY AND
STRENGTHEN MONDAY...RESULTING IN ANOTHER ROUND OF MODERATE TO
STRONG NORTH WINDS AND BUILDING SHORT PERIOD SEAS. -BPN
&&
.FIRE WEATHER...SATELLITE AND RADAR IMAGERY TO THE SOUTH SHOW SOME
CONVECTION HAS BEGUN IN ASSOCIATION WITH A SHORT WAVE AND MONSOONAL
MOISTURE THAT WILL BE MOVING INTO OUR AREA LATER THIS MORNING
THROUGH THIS AFTERNOON. SOME CLOUD-TO-CLOUD LIGHTNING HAS ALSO BEEN
DEPICTED WITH THESE BUILDUPS...SUGGESTING THAT A GOOD DEAL OF
INSTABILITY EXISTS OVER THE AREA THIS MORNING EVEN BEFORE SOLAR
HEATING BEGINS. MUCH DEPENDS ON THE TIMING OF THE SHORTWAVE AND THE
ARRIVAL OF MOISTURE...AS WELL AS WHAT AREAS RECEIVE THE MOST
HEATING...AND THE EXACT LOCATION OF JET ENERGY OVERHEAD WHICH COULD
LEND TO MORE NUMEROUS CELLS. STEERING WINDS ARE EXPECTED TO BE FROM
THE SOUTH AND SOUTHEAST WHICH IS A FAVORABLE FLOW TO GET STORMS TO
SPREAD OUT OVER THE VALLEYS WEST OF THE CASCADES. GIVEN THE DRY
FUELS AND EXPECTED NUMEROUS LIGHTNING STRIKES EXPECTED...HAVE
CONTINUED RED FLAG WARNINGS FOR NORTHERN CAL AND MOST OF OREGON
ZONES. THE EXCEPTION WILL BE THE COASTAL ZONES...WHERE THE
ATMOSPHERE SHOULD REMAIN MUCH MORE STABLE. EVEN THEN...CAN NOT RULE
OUT ISOLATED THUNDERSTORMS FOR FIRE ZONES 615 AND 618. MODELS
SUGGEST THE BULK OF THE ACTION WILL SHIFT NORTH DURING THE DAY TODAY
AND COULD BE OUT OF THE AREA BY THIS AFTERNOON...BUT AGAIN MUCH
DEPENDS ON THE TIMING. ANOTHER UPPER LOW WILL MOVE TOWARDS THE AREA
SUNDAY, BUT THE MODELS SUGGEST MOST OF THE INSTABILITY AND
THUNDERSTORM POTENTIAL WILL BE FROM AROUND CRATER LAKE NORTH. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR ORZ624-625.
RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR
ORZ616-617-619>623.
CA...RED FLAG WARNING UNTIL 6 PM PDT THIS EVENING FOR
CAZ280>282-284-285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM PDT THIS
MORNING FOR PZZ350-356-370-376.
$$
FJB/FJB/CC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1107 PM EDT SAT JUL 12 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST OFF THE MID ATLANTIC COAST SETTING
UP AN INCREASINGLY HUMID AIR FLOW OVER THE REGION. A PAIR OF COLD
FRONTS EARLY NEXT WEEK WILL EVENTUALLY USHER IN COOLER AND DRIER
AIR FOR MIDWEEK. THE COOL CONDITIONS WILL LAST THROUGH LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADAR SHOWS ONE LONELY SHOWER JUST EAST OF
WILLIAMSPORT...OTHERWISE IT`S DRY WITH JUST SOME THIN HIGH
CLOUDINESS DRIFTING ACROSS.
I USED THE LATEST HRRR AND NAM AND BACKED OFF ON THE TIMING OF
THE SHOWERS EXPECTED TO MOVE INTO THE NWRN ZONES LATER TONIGHT.
A POTENT SHORT WAVE IS HELPING ORGANIZE A LINE OF STORMS FROM
WISCONSIN TO SOUTHERN MISSOURI. THIS WILL PUSH SHOWERS AND
THUNDERSTORMS INTO NWRN ZONES AROUND OR SHORTLY AFTER SUNRISE.
INCREASING HIGH CLOUDS OVERNIGHT WILL HELP KEEP MIN TEMPS ABOVE
NORMAL...ONLY DROPPING INTO THE LOW TO MID 60S REGION-WIDE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SFC COLD FRONT WILL BE SLIDING GRADUALLY SE ACROSS THE GLAKES
SUNDAY...REACHING A LINE FROM NEAR CYYZ TO KTOL TO KIND AROUND 00Z
MONDAY.
REMNANT MID AND HIGH CLOUDS ARE EXPECTED FOR THE MORNING/MIDDAY
HOURS SUNDAY...FROM THE POTENTIAL UPSTREAM MCS. SCATTERED
SHRA/ISOLATED TSRA WILL DRIFT QUICKLY EAST /AT 35-40 KTS/ ACROSS
THE NORTHERN MTNS BETWEEN 12-16 SUNDAY.
AFTERWARD...A COMPLEX CLOUD/LLVL HEATING PATTERN WITH SEVERAL
OUTFLOW BOUNDARIES WILL FIRE OFF NEW /AND LOCALLY STRONG TO SVR
TSRA/ AS MEAN SFC BASED CAPES VIA THE SREF RAMP UP TO BETWEEN
1000-1500 J/KG...WITH POCKETS OF LOCALLY HIGHER INSTABILITY NEAR
2500 J/KG /VIA THE 12Z NAM/.
WHAT SIGNIFICANT POCKETS OF HIGHER CAPES CAN DEVELOP...THEY/LL
HAVE THE OPPORTUNITY TO COMBINE WITH MODERATELY STRONG SPEED AND
DIRECTIONAL SHEAR TO CREATE EHI/S OF 1.5-2.5 M2/S2. SPC ALSO NOTES
THAT MODEL HODOGRAPHS FAVOR BOWING LINE SEGMENTS AND EVEN A FEW
SUPERCELLS/BRIEF TORNADOES ACROSS THE CWA. THEIR DAY 2 SLIGHT RISK
AREA FOR SUNDAY COVERS A LITTLE MORE THAN THE SE HALF OF PENN.
THERE SHOULD BE 2-3 PRIMARY AREAS OF CONVECTION...THE FIRST BEING
DEVELOPING ACROSS CENTRAL/NRN PENN INVOF OF OUTFLOW
BOUNDARIES...THE SECOND NEAR THE LEE TROUGH ACROSS THE CENTRAL
MTNS AND SUSQ VALLEY...AND THE THIRD FORMING ACROSS THE WRN
MTNS...ALONG AND AHEAD OF THE APPROACHING CFRONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE FOCUS FOR THE BEST CONVERGENCE SHIFTS SLOWLY EAST ACROSS THE
AREA SUNDAY NIGHT AND MONDAY. HEIGHT FALLS OF 10DAM ARE EXPECTED
MONDAY AS A SIGNIFICANT TROUGH PUSHES FORCIBLY INTO THE NRN GREAT
LAKES. SPC HAS MOST OF THE CWA /EXCEPT FOR THE FAR NW ZONES/ IN
THE SLIGHT RISK AREA FOR MONDAY.
THE STORMS BOTH SUNDAY AND MONDAY WILL BE MOVING PRETTY FAST FROM
WEST TO EAST...BUT TRAINING IS POSSIBLE DUE TO THE E-W BAROCLINIC
ZONE.
PWATS INCREASE TO NEAR 2 INCHES ON MONDAY. THUS...SOME HEAVY RAIN
AND PERHAPS LOCALIZED FLOODING ARE POSSIBLE. CURRENTLY...3HR FFG
ACROSS THE REGION IS IN THE 2.5 TO 3.5 INCH RANGE...WHICH WILL
TEMPER THE RISK OF FLASH FLOODING UNLESS SEVERAL TSRA CAN TRAIN
OVER THE SAME LOCATIONS OVER THE SPAN OF JUST A FEW HOURS. SEVERAL
ROUNDS OF SHOWERS/TSRA SHOULD LOWER THESE FFG VALUES BY MONDAY
WHEN THE CFRONT MOVES THROUGH. WILL NOT MENTION FLOODING IN THE
HWO YET...BUT WILL CONTINUE TO MENTION THE POSSIBILITY OF SEVERE
TSRA MICROBURSTS.
THE GFS AND NAM GUIDANCE IS MUCH QUICKER TO PUSH THE FRONT
THROUGH...WITH THE ECMWF DEEPENING THE UPPER LEVEL TROUGH...THOUGH
THE LATEST RUN HAS OPENED UP THE CLOSED LOW. HOWEVER THE GFS
BRINGS IN THE DRIER AIR THROUGH QUICKER...KEEPING ALL BUT THE ERN
THIRD OF THE AREA DRY ON TUESDAY. THE EC DEVELOPS A COHERENT SFC
LOW OVER THE MID MS VALLEY AND MOVES IT TO OUR W/N ON TUESDAY AS
IT DEEPENS TO NEAR 1003MB. WILL THEREFORE KEEP ON WITH MENTIONS OF
SHRA/TSRA FOR THE ENTIRE SHORT TERM PERIOD.
HIGH AMPLITUDE RIDGE/TROUGH PATTERN DEVELOPS ACROSS THE MUCH OF
NORTH AMERICA BEGINNING LATE IN THE WEEKEND...AND CONTINUES
THROUGH THE FIRST HALF OF NEXT WEEK.
THE BRUNT OF THE GREATEST 850-700 MB TEMP ANOMALIES AND
ASSOCIATED BELOW NORMAL 500 MB HEIGHTS WILL BE AIMED AT THE LOWER
OHIO VALLEY AND MID MISS VALLEY TUESDAY AND WEDNESDAY...WITH OUR
REGION RESIDING ON THE ACTIVE/EASTERN SIDE OF THIS SLOW MOVING
FEATURE.
AS ADDITIONAL ENERGY IS DRIVEN SSE INTO THE BACK SIDE OF THE HIGH
AMPLITUDE MIDWEST TROUGH...PROLONGED HIGH PWAT AIR /AND LIFT
BENEATH THE RIGHT ENTRANCE REGION OF AN UPPER JET/ MAY LINGER
ACROSS THE SERN ZONES WITH SCATTERED...MAINLY AFTERNOON TSRA
WEDNESDAY AFTERNOON.
THE PATTERN OVER THE NRN CONUS AND SRN CANADA APPEARS TO DE-
AMPLIFY LATER NEXT WEEK AS THE EASTERN U.S. TROUGH BEGINS TO SHEAR
OUT TO THE NE.
THE DRIEST PERIOD OF THE LONG TERM WILL BE THURSDAY AND
FRIDAY...THOUGH SOME ISOLATED CONVECTION STILL CANT BE RULED OUT
EITHER OF THOSE TWO DAYS.
TEMPS START OUT AOA NORMAL PRECEDING THE CFROPA NEXT SUNDAY...AND
PERHAPS MONDAY ACROSS THE SE ZONES...THEN COOL TO AT LEAST 4-6F
BELOW NORMAL FOR DAYTIME HIGHS TUESDAY THROUGH THURSDAY. TEMPS
WILL LIKELY REBOUND TO NEAR NORMAL LATE NEXT WEEK.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS...CLEAR SKIES AND CALM WINDS...WILL PREVAIL
ACROSS PENNSYLVANIA TONIGHT.
MVFR FOG IS POSSIBLE ACROSS THE CENTRAL VALLEYS AND SUSQUEHANNA
REGION TAF SITES EARLY SUNDAY MORNING. RESIDUAL MOISTURE FROM
RAINFALL SATURDAY EVENING WILL AID IN FOG FORMATION AT KMDT AND
KLNS.
AN APPROACHING WARM FRONT WILL BRING THE CHANCE OF TSRA IMPACTS
TO THE NW MTNS SUNDAY. RA CHANCES AND CLOUD COVER WILL INCREASE
FROM NW TO SE THROUGHOUT THE DAY...BUT SITES WILL REMAIN MAINLY
VFR THROUGH THE TAF PERIOD. BRIEF REDUCTIONS IN VSBY AND CIGS ARE
POSSIBLE TOMORROW AFTERNOON IN THUNDERSTORMS.
OUTLOOK...
SUN...BRIEF THUNDERSTORM IMPACTS POSSIBLE.
SUN NIGHT-MON NIGHT...NUMEROUS SHOWERS/TSRA WITH MAINLY BRIEF
PERIODS OF IFR TO MVFR.
TUES-WED...THUNDERSTORM IMPACTS POSSIBLE...MAINLY IN THE
AFTERNOON.
THU...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...LAMBERT/COLBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1025 PM EDT SAT JUL 12 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST OFF THE MID ATLANTIC COAST SETTING
UP AN INCREASINGLY HUMID AIR FLOW OVER THE REGION. A PAIR OF COLD
FRONTS EARLY NEXT WEEK WILL EVENTUALLY USHER IN COOLER AND DRIER
AIR FOR MIDWEEK. THE COOL CONDITIONS WILL LAST THROUGH LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
RADAR SHOWS ONE LONELY SHOWER JUST EAST OF
WILLIAMSPORT...OTHERWISE IT`S DRY WITH JUST SOME THIN HIGH
CLOUDINESS DRIFTING ACROSS.
I USED THE LATEST HRRR AND NAM AND BACKED OFF ON THE TIMING OF
THE SHOWERS EXPECTED TO MOVE INTO THE NWRN ZONES LATER TONIGHT.
A POTENT SHORT WAVE IS HELPING ORGANIZE A LINE OF STORMS FROM
WISCONSIN TO SOUTHERN MISSOURI. THIS WILL PUSH SHOWERS AND
THUNDERSTORMS INTO NWRN ZONES AROUND OR SHORTLY AFTER SUNRISE.
INCREASING HIGH CLOUDS OVERNIGHT WILL HELP KEEP MIN TEMPS ABOVE
NORMAL...ONLY DROPPING INTO THE LOW TO MID 60S REGION-WIDE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SFC COLD FRONT WILL BE SLIDING GRADUALLY SE ACROSS THE GLAKES
SUNDAY...REACHING A LINE FROM NEAR CYYZ TO KTOL TO KIND AROUND 00Z
MONDAY.
REMNANT MID AND HIGH CLOUDS ARE EXPECTED FOR THE MORNING/MIDDAY
HOURS SUNDAY...FROM THE POTENTIAL UPSTREAM MCS. SCATTERED
SHRA/ISOLATED TSRA WILL DRIFT QUICKLY EAST /AT 35-40 KTS/ ACROSS
THE NORTHERN MTNS BETWEEN 12-16 SUNDAY.
AFTERWARD...A COMPLEX CLOUD/LLVL HEATING PATTERN WITH SEVERAL
OUTFLOW BOUNDARIES WILL FIRE OFF NEW /AND LOCALLY STRONG TO SVR
TSRA/ AS MEAN SFC BASED CAPES VIA THE SREF RAMP UP TO BETWEEN
1000-1500 J/KG...WITH POCKETS OF LOCALLY HIGHER INSTABILITY NEAR
2500 J/KG /VIA THE 12Z NAM/.
WHAT SIGNIFICANT POCKETS OF HIGHER CAPES CAN DEVELOP...THEY/LL
HAVE THE OPPORTUNITY TO COMBINE WITH MODERATELY STRONG SPEED AND
DIRECTIONAL SHEAR TO CREATE EHI/S OF 1.5-2.5 M2/S2. SPC ALSO NOTES
THAT MODEL HODOGRAPHS FAVOR BOWING LINE SEGMENTS AND EVEN A FEW
SUPERCELLS/BRIEF TORNADOES ACROSS THE CWA. THEIR DAY 2 SLIGHT RISK
AREA FOR SUNDAY COVERS A LITTLE MORE THAN THE SE HALF OF PENN.
THERE SHOULD BE 2-3 PRIMARY AREAS OF CONVECTION...THE FIRST BEING
DEVELOPING ACROSS CENTRAL/NRN PENN INVOF OF OUTFLOW
BOUNDARIES...THE SECOND NEAR THE LEE TROUGH ACROSS THE CENTRAL
MTNS AND SUSQ VALLEY...AND THE THIRD FORMING ACROSS THE WRN
MTNS...ALONG AND AHEAD OF THE APPROACHING CFRONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE FOCUS FOR THE BEST CONVERGENCE SHIFTS SLOWLY EAST ACROSS THE
AREA SUNDAY NIGHT AND MONDAY. HEIGHT FALLS OF 10DAM ARE EXPECTED
MONDAY AS A SIGNIFICANT TROUGH PUSHES FORCIBLY INTO THE NRN GREAT
LAKES. SPC HAS MOST OF THE CWA /EXCEPT FOR THE FAR NW ZONES/ IN
THE SLIGHT RISK AREA FOR MONDAY.
THE STORMS BOTH SUNDAY AND MONDAY WILL BE MOVING PRETTY FAST FROM
WEST TO EAST...BUT TRAINING IS POSSIBLE DUE TO THE E-W BAROCLINIC
ZONE.
PWATS INCREASE TO NEAR 2 INCHES ON MONDAY. THUS...SOME HEAVY RAIN
AND PERHAPS LOCALIZED FLOODING ARE POSSIBLE. CURRENTLY...3HR FFG
ACROSS THE REGION IS IN THE 2.5 TO 3.5 INCH RANGE...WHICH WILL
TEMPER THE RISK OF FLASH FLOODING UNLESS SEVERAL TSRA CAN TRAIN
OVER THE SAME LOCATIONS OVER THE SPAN OF JUST A FEW HOURS. SEVERAL
ROUNDS OF SHOWERS/TSRA SHOULD LOWER THESE FFG VALUES BY MONDAY
WHEN THE CFRONT MOVES THROUGH. WILL NOT MENTION FLOODING IN THE
HWO YET...BUT WILL CONTINUE TO MENTION THE POSSIBILITY OF SEVERE
TSRA MICROBURSTS.
THE GFS AND NAM GUIDANCE IS MUCH QUICKER TO PUSH THE FRONT
THROUGH...WITH THE ECMWF DEEPENING THE UPPER LEVEL TROUGH...THOUGH
THE LATEST RUN HAS OPENED UP THE CLOSED LOW. HOWEVER THE GFS
BRINGS IN THE DRIER AIR THROUGH QUICKER...KEEPING ALL BUT THE ERN
THIRD OF THE AREA DRY ON TUESDAY. THE EC DEVELOPS A COHERENT SFC
LOW OVER THE MID MS VALLEY AND MOVES IT TO OUR W/N ON TUESDAY AS
IT DEEPENS TO NEAR 1003MB. WILL THEREFORE KEEP ON WITH MENTIONS OF
SHRA/TSRA FOR THE ENTIRE SHORT TERM PERIOD.
HIGH AMPLITUDE RIDGE/TROUGH PATTERN DEVELOPS ACROSS THE MUCH OF
NORTH AMERICA BEGINNING LATE IN THE WEEKEND...AND CONTINUES
THROUGH THE FIRST HALF OF NEXT WEEK.
THE BRUNT OF THE GREATEST 850-700 MB TEMP ANOMALIES AND
ASSOCIATED BELOW NORMAL 500 MB HEIGHTS WILL BE AIMED AT THE LOWER
OHIO VALLEY AND MID MISS VALLEY TUESDAY AND WEDNESDAY...WITH OUR
REGION RESIDING ON THE ACTIVE/EASTERN SIDE OF THIS SLOW MOVING
FEATURE.
AS ADDITIONAL ENERGY IS DRIVEN SSE INTO THE BACK SIDE OF THE HIGH
AMPLITUDE MIDWEST TROUGH...PROLONGED HIGH PWAT AIR /AND LIFT
BENEATH THE RIGHT ENTRANCE REGION OF AN UPPER JET/ MAY LINGER
ACROSS THE SERN ZONES WITH SCATTERED...MAINLY AFTERNOON TSRA
WEDNESDAY AFTERNOON.
THE PATTERN OVER THE NRN CONUS AND SRN CANADA APPEARS TO DE-
AMPLIFY LATER NEXT WEEK AS THE EASTERN U.S. TROUGH BEGINS TO SHEAR
OUT TO THE NE.
THE DRIEST PERIOD OF THE LONG TERM WILL BE THURSDAY AND
FRIDAY...THOUGH SOME ISOLATED CONVECTION STILL CANT BE RULED OUT
EITHER OF THOSE TWO DAYS.
TEMPS START OUT AOA NORMAL PRECEDING THE CFROPA NEXT SUNDAY...AND
PERHAPS MONDAY ACROSS THE SE ZONES...THEN COOL TO AT LEAST 4-6F
BELOW NORMAL FOR DAYTIME HIGHS TUESDAY THROUGH THURSDAY. TEMPS
WILL LIKELY REBOUND TO NEAR NORMAL LATE NEXT WEEK.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS WILL PREVAIL FOR THE REGION TONIGHT. VCSH
WILL REMAIN POSSIBLE AT KMDT AND KLNS FOR THE NEXT FEW HOURS. VSBY
AND CIGS MAY BRIEFLY DROP TO MVFR AT THESE SITES....BUT DUE TO
BREVITY AND UNCERTAINTY WILL LEAVE OUT FROM ACTUAL TAFS.
MVFR FOG IS POSSIBLE ACROSS THE CENTRAL VALLEYS AND SUSQUEHANNA
REGION TAF SITES EARLY SUNDAY MORNING. RESIDUAL MOISTURE FROM
RAINFALL THIS EVENING WILL AID IN FOG FORMATION AT KMDT AND KLNS.
AN APPROACHING WARM FRONT WILL BRING THE CHANCE OF TSRA IMPACTS
TO THE NW MTNS TOWARD DAWN SUNDAY. RA CHANCES WILL INCREASE FROM
NW TO SE THROUGHOUT THE DAY...BUT MOST SITES WILL REMAIN VFR
THROUGH THE TAF PERIOD. BRIEF REDUCTIONS IN VSBY AND CIGS ARE
POSSIBLE TOMORROW AFTERNOON IN THUNDERSTORMS.
OUTLOOK...
SUN...BRIEF THUNDERSTORM IMPACTS POSSIBLE.
SUN NIGHT-MON NIGHT...NUMEROUS SHOWERS/TSRA WITH MAINLY BRIEF
PERIODS OF IFR TO MVFR.
TUES-WED...THUNDERSTORM IMPACTS POSSIBLE...MAINLY IN THE
AFTERNOON.
THU...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...DANGELO/LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...LAMBERT/COLBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
801 PM EDT SAT JUL 12 2014
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST OFF THE MID ATLANTIC COAST SETTING
UP AN INCREASINGLY HUMID AIR FLOW OVER THE REGION. A PAIR OF COLD
FRONTS EARLY NEXT WEEK WILL EVENTUALLY USHER IN COOLER AND DRIER
AIR FOR MIDWEEK. THE COOL CONDITIONS WILL LAST THROUGH LATE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WEAK AREA OF CONVERGENCE EVIDENT EARLIER IN THE CU FIELD OVER
MY EASTERN ZONES RESULTED IN SEVERAL PULSE THUNDERSTORMS...SOME
OF WHICH CAUSED A QUICK 1-3 INCHES OF RAIN TO FALL IN THE HUMID
AIRMASS. ACTIVITY HAS SHOWN A DECREASE OVER THE LAST HOUR...BUT
STILL SOME CELLS NORTH OF HARRISBURG...AS WELL AS NE OF
WILLIAMSPORT. HRRR GUIDANCE SUGGESTS THE CONVECTION WILL CONTINUE
TO FADE WITH THE SETTING SUN.
A FAIRLY POTENT VORT MAX/SHORT WAVE TROUGH WILL PUSH EAST THROUGH
THE LOWER LAKES LATE TONIGHT. SHRA/TSRA SHOULD APPROACH THE NWRN
COUNTIES AS A 35-40KT SWRLY LLJET DEVELOPS IN OHIO AND SPREADS
INTO NRN PA.
WILL KEEP CONTINUITY WITH POPS INCREASING TONIGHT...WITH THE
ARRIVAL OF SHOWERS/TSRA MAINLY AFTER 07Z SUNDAY. CLOUD COVER
INCREASES OVERNIGHT...SO TEMPS WILL LIKELY NOT DROP TO NEAR
NORMAL. EXPECT FAIRLY UNIFORM LOWS IN THE 60S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SFC COLD FRONT WILL BE SLIDING GRADUALLY SE ACROSS THE GLAKES
SUNDAY...REACHING A LINE FROM NEAR CYYZ TO KTOL TO KIND AROUND 00Z
MONDAY.
REMNANT MID AND HIGH CLOUDS ARE EXPECTED FOR THE MORNING/MIDDAY
HOURS SUNDAY...FROM THE POTENTIAL UPSTREAM MCS. SCATTERED
SHRA/ISOLATED TSRA WILL DRIFT QUICKLY EAST /AT 35-40 KTS/ ACROSS
THE NORTHERN MTNS BETWEEN 12-16 SUNDAY.
AFTERWARD...A COMPLEX CLOUD/LLVL HEATING PATTERN WITH SEVERAL
OUTFLOW BOUNDARIES WILL FIRE OFF NEW /AND LOCALLY STRONG TO SVR
TSRA/ AS MEAN SFC BASED CAPES VIA THE SREF RAMP UP TO BETWEEN
1000-1500 J/KG...WITH POCKETS OF LOCALLY HIGHER INSTABILITY NEAR
2500 J/KG /VIA THE 12Z NAM/.
WHAT SIGNIFICANT POCKETS OF HIGHER CAPES CAN DEVELOP...THEY/LL
HAVE THE OPPORTUNITY TO COMBINE WITH MODERATELY STRONG SPEED AND
DIRECTIONAL SHEAR TO CREATE EHI/S OF 1.5-2.5 M2/S2. SPC ALSO NOTES
THAT MODEL HODOGRAPHS FAVOR BOWING LINE SEGMENTS AND EVEN A FEW
SUPERCELLS/BRIEF TORNADOES ACROSS THE CWA. THEIR DAY 2 SLIGHT RISK
AREA FOR SUNDAY COVERS A LITTLE MORE THAN THE SE HALF OF PENN.
THERE SHOULD BE 2-3 PRIMARY AREAS OF CONVECTION...THE FIRST BEING
DEVELOPING ACROSS CENTRAL/NRN PENN INVOF OF OUTFLOW
BOUNDARIES...THE SECOND NEAR THE LEE TROUGH ACROSS THE CENTRAL
MTNS AND SUSQ VALLEY...AND THE THIRD FORMING ACROSS THE WRN
MTNS...ALONG AND AHEAD OF THE APPROACHING CFRONT.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
THE FOCUS FOR THE BEST CONVERGENCE SHIFTS SLOWLY EAST ACROSS THE
AREA SUNDAY NIGHT AND MONDAY. HEIGHT FALLS OF 10DAM ARE EXPECTED
MONDAY AS A SIGNIFICANT TROUGH PUSHES FORCIBLY INTO THE NRN GREAT
LAKES. SPC HAS MOST OF THE CWA /EXCEPT FOR THE FAR NW ZONES/ IN
THE SLIGHT RISK AREA FOR MONDAY.
THE STORMS BOTH SUNDAY AND MONDAY WILL BE MOVING PRETTY FAST FROM
WEST TO EAST...BUT TRAINING IS POSSIBLE DUE TO THE E-W BAROCLINIC
ZONE.
PWATS INCREASE TO NEAR 2 INCHES ON MONDAY. THUS...SOME HEAVY RAIN
AND PERHAPS LOCALIZED FLOODING ARE POSSIBLE. CURRENTLY...3HR FFG
ACROSS THE REGION IS IN THE 2.5 TO 3.5 INCH RANGE...WHICH WILL
TEMPER THE RISK OF FLASH FLOODING UNLESS SEVERAL TSRA CAN TRAIN
OVER THE SAME LOCATIONS OVER THE SPAN OF JUST A FEW HOURS. SEVERAL
ROUNDS OF SHOWERS/TSRA SHOULD LOWER THESE FFG VALUES BY MONDAY
WHEN THE CFRONT MOVES THROUGH. WILL NOT MENTION FLOODING IN THE
HWO YET...BUT WILL CONTINUE TO MENTION THE POSSIBILITY OF SEVERE
TSRA MICROBURSTS.
THE GFS AND NAM GUIDANCE IS MUCH QUICKER TO PUSH THE FRONT
THROUGH...WITH THE ECMWF DEEPENING THE UPPER LEVEL TROUGH...THOUGH
THE LATEST RUN HAS OPENED UP THE CLOSED LOW. HOWEVER THE GFS
BRINGS IN THE DRIER AIR THROUGH QUICKER...KEEPING ALL BUT THE ERN
THIRD OF THE AREA DRY ON TUESDAY. THE EC DEVELOPS A COHERENT SFC
LOW OVER THE MID MS VALLEY AND MOVES IT TO OUR W/N ON TUESDAY AS
IT DEEPENS TO NEAR 1003MB. WILL THEREFORE KEEP ON WITH MENTIONS OF
SHRA/TSRA FOR THE ENTIRE SHORT TERM PERIOD.
HIGH AMPLITUDE RIDGE/TROUGH PATTERN DEVELOPS ACROSS THE MUCH OF
NORTH AMERICA BEGINNING LATE IN THE WEEKEND...AND CONTINUES
THROUGH THE FIRST HALF OF NEXT WEEK.
THE BRUNT OF THE GREATEST 850-700 MB TEMP ANOMALIES AND
ASSOCIATED BELOW NORMAL 500 MB HEIGHTS WILL BE AIMED AT THE LOWER
OHIO VALLEY AND MID MISS VALLEY TUESDAY AND WEDNESDAY...WITH OUR
REGION RESIDING ON THE ACTIVE/EASTERN SIDE OF THIS SLOW MOVING
FEATURE.
AS ADDITIONAL ENERGY IS DRIVEN SSE INTO THE BACK SIDE OF THE HIGH
AMPLITUDE MIDWEST TROUGH...PROLONGED HIGH PWAT AIR /AND LIFT
BENEATH THE RIGHT ENTRANCE REGION OF AN UPPER JET/ MAY LINGER
ACROSS THE SERN ZONES WITH SCATTERED...MAINLY AFTERNOON TSRA
WEDNESDAY AFTERNOON.
THE PATTERN OVER THE NRN CONUS AND SRN CANADA APPEARS TO DE-
AMPLIFY LATER NEXT WEEK AS THE EASTERN U.S. TROUGH BEGINS TO SHEAR
OUT TO THE NE.
THE DRIEST PERIOD OF THE LONG TERM WILL BE THURSDAY AND
FRIDAY...THOUGH SOME ISOLATED CONVECTION STILL CANT BE RULED OUT
EITHER OF THOSE TWO DAYS.
TEMPS START OUT AOA NORMAL PRECEDING THE CFROPA NEXT SUNDAY...AND
PERHAPS MONDAY ACROSS THE SE ZONES...THEN COOL TO AT LEAST 4-6F
BELOW NORMAL FOR DAYTIME HIGHS TUESDAY THROUGH THURSDAY. TEMPS
WILL LIKELY REBOUND TO NEAR NORMAL LATE NEXT WEEK.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS WILL PREVAIL FOR THE REGION TONIGHT. VCSH
WILL REMAIN POSSIBLE AT KMDT AND KLNS FOR THE NEXT FEW HOURS. VSBY
AND CIGS MAY BRIEFLY DROP TO MVFR AT THESE SITES....BUT DUE TO
BREVITY AND UNCERTAINTY WILL LEAVE OUT FROM ACTUAL TAFS.
MVFR FOG IS POSSIBLE ACROSS THE CENTRAL VALLEYS AND SUSQUEHANNA
REGION TAF SITES EARLY SUNDAY MORNING. RESIDUAL MOISTURE FROM
RAINFALL THIS EVENING WILL AID IN FOG FORMATION AT KMDT AND KLNS.
AN APPROACHING WARM FRONT WILL BRING THE CHANCE OF TSRA IMPACTS
TO THE NW MTNS TOWARD DAWN SUNDAY. RA CHANCES WILL INCREASE FROM
NW TO SE THROUGHOUT THE DAY...BUT MOST SITES WILL REMAIN VFR
THROUGH THE TAF PERIOD. BRIEF REDUCTIONS IN VSBY AND CIGS ARE
POSSIBLE TOMORROW AFTERNOON IN THUNDERSTORMS.
OUTLOOK...
SUN...BRIEF THUNDERSTORM IMPACTS POSSIBLE.
SUN NIGHT-MON NIGHT...NUMEROUS SHOWERS/TSRA WITH MAINLY BRIEF
PERIODS OF IFR TO MVFR.
TUES-WED...THUNDERSTORM IMPACTS POSSIBLE...MAINLY IN THE
AFTERNOON.
THU...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...DANGELO/LAMBERT
LONG TERM...DANGELO/CERU
AVIATION...LAMBERT/COLBERT
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
437 AM EDT FRI JUL 11 2014
.SYNOPSIS...
THE UPPER AIR FLOW WILL BECOME WESTERLY THIS WEEKEND. TEMPERATURES
WILL BE SEASONABLE TODAY BUT BECOME HOTTER ON SATURDAY AND
SUNDAY. DESPITE THE INFLUENCE OF HIGH PRESSURE AT THE
SURFACE...THE AREA WILL REMAIN VULNERABLE FOR ISOLATED SHOWERS AND
THUNDERSTORMS TO POP UP EACH AFTERNOON OFF THE HIGH TERRAIN.
HIGHER CHANCES OF STORMS ARE EXPECTED MONDAY AND TUESDAY AS A
VERY STRONG TROUGH OF POLAR AIR WILL PUSH SOUTHWARD INTO THE GREAT
LAKES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOG BEGINNING TO SHOW IT/S HAND...DEVELOPING IN THE COOL SINKS
WHERE THE RAINFALL OCCURRED YESTERDAY. VISBYS WILL GRADUALLY
DECLINE IN MANY SPOTS ACROSS THE SRN HALF OF THE REGION...WHERE
THE AMBIENT MOISTURE IS HIGHEST. THE FOG WILL BURN OFF BY 9 AM AS
THE ATMOS MIXES QUICKLY UNDER OTHERWISE SUNNY SKIES. THE VERY DRY
/FOR JULY/ DEWPOINTS NEAR 50F IN THE NORTHERN TIER WILL MOST
LIKELY RISE A BIT THIS MORNING. THE PATTERN OF CONVECTIVE CLOUDS
POPPING UP LATE MORNING OVER THE HIGH TERRAIN OF THE ALLEGHENIES
WILL HAPPEN ONCE AGAIN TODAY. A SUBTLE SHORT WAVE FEATURE OVER THE
NORTHWEST THIS MORNING WILL SLIDE EAST AND WILL LIKELY CAUSE THE
SHORT CU TO GROW BIGGER AND PRODUCE ISOLD T/SHRA IN THE AFTN. IT
MAY ALSO HELP SOME SHRA GROW IN THE SERN PART OF THE AREA - AGAIN
MAINLY OFF THE ELEVATED HEATING SURFACES - AND DRIFT EASTWARD.
TEMPS WILL PROBABLY BE A LITTLE MORE HOMOGENOUS TODAY- THE DRIER
AIR OVER THE NW WILL BE HEATED EASILY BY THE JULY SUN...AND MORE
CLOUDS OVER THE SE IN MID-DAY/AFTN WILL CUT A DEG OR TWO OFF
YESTERDAY/S MAXES THERE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
AFTN CONVECTION WILL WANE VERY QUICKLY AS WE WILL BE IN THE
UNFAVORABLE WAKE/HEIGHT BUMP/SUBSIDENCE OF A WEAK SHORT WAVE.
WILL CHOP THE POPS OFF AFTER SUNSET...BUT IT MAY HAPPEN EARLIER.
MINS TONIGHT WILL BE SIMILAR TO THIS MORNING. SATURDAY LOOKS LIKE
THERE COULD STILL BE A FEW SHRA AROUND. WILL KEEP ON WITH THE
IDEA OF TERRAIN INDUCED SHRA. NO BIG CHANGES TO THE AIRMASS...NOR
TO THE UPPER PATTERN/TEMPS THROUGH THE SHORT TERM. BUT THE SFC
HIGH DOES SLIDE TO THE SHORE AND ALLOW MORE SOUTHERLY WINDS.
THUS...TEMPS SHOULD GET HOTTER FOR SAT. U80S ARE EXPECTED IN THE
EASTERN VALLEYS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
STALLED FRONT ALONG THE SOUTHEAST COAST SHOULD PIVOT BACK NWD AS
WARM FRONT SAT NGT INTO EARLY SUNDAY WITH S-SWLY LLJ INC LLVL MSTR
FLUX THRU THE UPPER OH VLY INTO WRN PA IN ADVANCE OF LEAD
SHORTWAVE ENERGY AND ASSOCD SFC COLD FRONT MOVG SEWD ACRS THE GRT
LKS-MIDWEST.
AMPLIFICATION OF THE UPPER PATTERN BEGINS EARLY NEXT WEEK WITH A
MODEL CONSENSUS GENERALLY INDICATING A FRONTAL PCPN AXIS SHIFTING
SEWD THRU THE GRT LKS/OH VLY REGIONS INTO CENTRAL PA SUN-MON.
ALTHOUGH PREDICTABILITY IS TOO LOW ATTM...A SEVERE WX THREAT
SHOULD SPREAD SEWD IN TIME FROM THE UPPER MIDWEST/GRT LKS/OH VLY
INTO THE MID ATLC AND NORTHEAST STATES...ALONG SRN PERIPHERY OF
STRONGER WINDS/CYC FLOW ALOFT AND SEVERAL REINFORCING COLD
FRONTAL SURGES ASSOCIATED WITH THE AMPLIFYING SYNOPTIC UPPER
TROUGH. EACH COLD FRONTAL SURGE WILL PROVIDE AN OPPORTUNITY FOR
SHOWERS/TSTMS THROUGH AT LEAST TUESDAY.
THE HIGHLY ANOMALOUS AMPLIFICATION OF THE LARGE SCALE PATTERN IS
A VIRTUAL LOCK BY THE END OF THE PERIOD AS INDICATED BY ALL MEDIUM
RANGE GLOBAL NUMERICAL MODELS AND ENSEMBLE SYSTEMS. THIS WELL-
ADVERTISED HIGH MERIDIONAL EVENT WILL FEATURE A FULL-LATITUDE
RIDGE AND SEARING HEAT OUT WEST...NOT BE BE OUTDONE BY THE RETURN
OF THE POLAR VORTEX IN THE EAST OVER QUE/ONT AND THE UPPER GREAT
LAKES. CONSIDERING THE MAGNITUDE OF THE UPPER LEVEL TROUGH WITH
500MB STANDARDIZED ANOMALIES ON THE ORDER OF -3 TO -4SD IN BOTH
THE DETERMINISTIC GLOBAL MODELS AND THEIR RESPECTIVE ENSEMBLE
MEANS...CONFIDENCE IN A PERIOD OF BELOW AVG TEMPS /DURING WHAT IS
CLIMATOLOGICALLY THE HOTTEST TIME OF THE YEAR/ IS VERY HIGH FROM
TUE-THU OF NEXT WEEK.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
MCLEAR SKIES AND LIGHT WIND WILL PROMOTE AREAS OF FOG EARLY THIS
MORNING ACROSS SOUTHERN PA...WHERE THE GROUND REMAINS WET FROM RAIN
LAST EVENING. A COMBINATION OF 05Z DWPT DEPRESSIONS...SREF AND
LATEST RAP OUTPUT ALL SUGGEST IFR VSBYS AT KAOO AND KLNS ARE VERY
LIKELY EARLY THIS AM AND POSSIBLE AT KUNV AND KMDT. FURTHER
NORTH...CAN/T RULE OUT SOME FOG TOWARD DAYBREAK AT KBFD AND KIPT.
HOWEVER...THIS AREA MISSED THE RAINFALL FROM LAST EVENING AND
LATEST RAP SUGGESTS DRIER AIR POISED ACROSS NY STATE WILL WORK
INTO NORTHERN PA ON NORTHERLY BREEZE EARLY THIS AM...MINIMIZING
THE FOG THREAT.
ANY EARLY FOG SHOULD BURN OFF BY ARND 12Z. WITH HIGH PRESSURE
OVER THE AREA...THERE IS A HIGH CONFIDENCE IN WIDESPREAD VFR
CONDS AND LGT WIND THE REST OF TODAY.
OUTLOOK...
SAT...NO SIG WX EXPECTED.
SUN-TUE...BRIEF...MAINLY PM...THUNDERSTORM IMPACTS POSSIBLE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1004 PM EDT SAT JUL 12 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL LINGER OVER THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA THE REST OF THE WEEKEND. AN UNSEASONABLY STRONG
COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON MONDAY AND
CROSS THE REGION TUESDAY. COOLER THAN NORMAL TEMPERATURES WILL
ARRIVE FROM MID TO LATE WEEK BEHIND THE FRONT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 10 PM...LATEST RADAR IMAGES INDICATE ONLY A COUPLE OF WEAK
SHOWERS ACROSS THE MTNS AND FOOTHILLS. I WILL UPDATE TO LOWER POPS
TO SCHC. FOG HAS STARTED TO FORM ACROSS THE EXTREME WESTERN NC MTN
VALLEYS...FORECAST APPEARS ON TRACK.
AS OF 740 PM...THE FORECAST TRENDS LOOK GOOD. I WILL UPDATE TO
ADJUST SKY AND TEMPERATURES TO OBSERVATIONS. CONDITIONS LOOK
FAVORABLE FOR MTN VALLEY FOG TONIGHT...A LITTLE LESS COVERAGE AND
DURATION THAN THIS MORNING. KCAE RADAR INDICATES THAT A SEA BREEZE
BOUNDARY WAS TRACKING STEADILY WEST. SOME PATCHY FOG IS POSSIBLE IN
THE WAKE OF THE BOUNDARY...GENERALLY ACROSS THE MIDLANDS.
AS 530 PM...THE CURRENT FORECAST REMAINS IN GREAT SHAPE. SCT
CONVECTION OVER THE MTNS HAS TRENDED WEAKER OVER THE PAST HOUR...BUT
COVERAGE HAS REMAINED NEARLY UNCHANGED. I WILL UPDATE THE FORECAST
TO ALIGN SKY WITH SATELLITE OBSERVATIONS AND TO TWEAK TEMPS.
OTHERWISE...CHANGES TO FORECAST WILL BE MINOR.
AT 245 PM EDT SATURDAY... CURRENT MESOANALYSIS INDICATES CAPES OVER
THE MOUNTAINS ARE AROUND 1500 J/KG AND GENERALLY LESS THAN 1000 J/KG
EAST OF THE MOUNTAINS. RAP FORECAST INTO THE EVENING SHOWS CAPE
PERSISTS FOR A WHILE IN THE FAR WESTERN ZONES... ALIGNED WITH THE
AXIS OF HIGH TERRAIN... BUT CAPE DECREASES SUBSTANTIALLY IN THE
EAST. AS HAS BEEN THE CASE DURING THE PAST COUPLE OF NIGHTS...
ISOLATED CONVECTIVE STORMS MIGHT CONTINUE WELL AFTER SUNSET. VERY
LIGHT WINDS THROUGH A DEEP LAYER COULD RESULT IN SLOWLY MOVING
THUNDERSTORMS AND THE POTENTIAL FOR LOCALLY EXCESSIVE RAINFALL.
OTHERWISE... PRIMARY FEATURE ALOFT AFFECTING OUR WEATHER THROUGH
SUNDAY IS A RIDGE EXTENDING FROM THE WEST COAST ACROSS THE SOUTHERN
STATES TO THE CAROLINAS. AT THE SURFACE... HIGH PRESSURE WITH A VERY
WEAK GRADIENT WILL COVER THE REGION. AS HEIGHTS FALL OVER THE
NORTHERN U.S. ON SUNDAY... THE EASTERN PERIPHERY OF THE UPPER LEVEL
RIDGE WILL WITHDRAW WESTWARD A BIT... BUT THROUGH TOMORROW THE RIDGE
IS GOING TO BE THE PRIMARY PLAYER IN CONTINUING THE CURRENT PERIOD
OF GENERALLY TRANQUIL WEATHER. THE AIR MASS OVER THE WESTERN ZONES
WILL REMAIN FAIRLY MOIST AND MODERATELY UNSTABLE THUS SUPPORTING
SCATTERED SHOWERS AND THUNDERSTORMS WHICH WILL BE MOST NUMEROUS OVER
THE HIGHER TERRAIN. CAPE VALUES EAST OF THE MOUNTAINS ON SUNDAY WILL
BE HELD AT BAY BY A RATHER WARM TEMPERATURE PROFILE. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE... BUT CUMULUS AND TOWERING
CUMULUS SHOULD DOMINATE THE SKY IN OUR PIEDMONT ZONES TOMORROW. LOWS
WILL BE AROUND 70 IN THE PIEDMONT AND IN THE 60S IN THE MOUNTAINS.
HIGHS ON SUNDAY WILL BE FAIRLY CLOSE TO NORMAL... PERHAPS A FEW
DEGREES ABOVE NORMAL AT A FEW LOCATIONS. HIGHS WILL BE AROUND 90
EAST OF THE MOUNTAINS AND IN THE LOWER AND MID 80S IN THE MOUNTAIN
VALLEYS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 230 PM EDT SATURDAY...THE SHORT RANGE PERIOD INITIALIZES
SUNDAY EVENING WITH A BROAD LONGWAVE UPPER TROF ROTATING ACROSS
SOUTHERN ONTARIO. MEANWHILE...BERMUDA HIGH WILL CONTINUE TO ADVECT
WARM/MOIST AIR ACROSS THE SOUTHEAST...NORTHWARD INTO THE MID
ATLANTIC STATES. EXPECTING ONGOING CONVECTION ACROSS THE HIGH
TERRAIN AT FORECAST INITIALIZATION DUE TO IMPROVED INSTABILITY AXIS
AND WEAK SOUTHERLY UPSLOPE FLOW. CHANCE LEVEL POPS WILL BE
FEATURED INITIALLY ACROSS THE HIGH TERRAIN BEFORE TAPERING DOWN TO
SLIGHT CHANCE LEVELS BY DAYBREAK. BY MONDAY MORNING...THE
FIRST...AND WEAKER OF TWO COLD FRONTAL BOUNDARIES WILL APPROACH THE
REGION FROM THE WEST. ADJACENT WEAK UPPER IMPULSE COMBINED WITH
BOUNDARY INTRUSION WILL SPAWN CONVECTION ACROSS THE
MOUNTAINS/FOOTHILLS DURING THE AFTERNOON HOURS ON MONDAY. DUE TO
THE SUSTAINED SOUTHERLY FLOW IN DAYS PAST...THE ATMOSPHERE WILL HAVE
RECOVERED ENOUGH TO YIELD A MODERATELY UNSTABLE WARM SECTOR AHEAD OF
THIS FRONT. THUS...EXPECTING SHOWERS AND THUNDERSTORMS TO SPILL OUT
OF THE HIGH TERRAIN AND PROPAGATE EAST INTO THE PIEDMONT/FOOTHILLS
MONDAY EVENING. AS SAID ABOVE...SUBSTANTIAL CAPE WILL BE PRESENT TO
SUPPORT SOME DEEPER UPDRAFTS LEADING TO A FEW STRONG/SEVERE
THUNDERSTORMS MONDAY AFTERNOON/EVENING...DESPITE WEAKER YET
IMPROVING SHEAR. FORECAST WILL FEATURE LIKELY POPS ACROSS THE
MAJORITY OF THE MOUNTAIN/FOOTHILLS ZONES WHILE LOWER CHANCE POPS ARE
HIGHLIGHTED SOUTH EASTWARD ACROSS NORTHEAST GA AND THE NC/SC
PIEDMONTS.
TUESDAY MORNING THE ABOVE MENTIONED BOUNDARY WILL HAVE ESSENTIALLY
DISSIPATED AND BECOME STATIONARY ACROSS CENTRAL NC...SOUTHWARD
INTO THE MIDLANDS OF SC. AT THE SAME TIME THE RATHER
DEEP/IMPRESSIVE UPPER LOW WILL ROTATE DOWN ACROSS THE GREAT LAKES
WHILE SURFACE CYCLOGENESIS OCCURS ALONG THE EASTERN SEABOARD. THE
STRONG COLD FRONT WILL BE PUSHING THROUGH THE OHIO VALLEY BY EARLY
MORNING...EASTWARD INTO THE CENTRAL/SOUTHERN APPS BY MID/LATE
MORNING...THEN FINALLY FURTHER EAST INTO THE PIEDMONT REGIONS ON
TUESDAY AFTERNOON/EVENING. EXPECTING THE ABOVE MENTIONED SURFACE
CYCLONE TO DEEPEN SLIGHTLY AND AID IN DEVELOPMENT OF A LEE SIDE
TROF ACROSS THE PIEDMONT/COASTAL PLAINS OF NC LATE IN THE
AFTERNOON. THIS WEAK/DIFFUSE BOUNDARY COULD PROVIDE A FOCUS FOR
SURFACE CONVERGENCE AHEAD OF THE APPROACHING/STRONG COLD FRONT.
THERE WILL BE SUFFICIENT UPPER SUPPORT...SHEAR...AND BUOYANCY IN
PLACE TO SUPPORT ORGANIZED STRONG/SEVERE CONVECTION ACROSS THE
ENTIRE REGION ON TUESDAY. THE FORECAST WILL FEATURE WIDESPREAD
LIKELY POPS FOR TUESDAY ENCOMPASSING THE ENTIRE REGION. WILL
CONTINUE WITH SEVERE THUNDERSTORM POSSIBLE WORDING IN THE HWO FOR
BOTH MONDAY EVENING/OVERNIGHT...AND THROUGH THE DAY ON TUESDAY.
TEMPERATURES WILL BE ABOVE NORMAL ON MONDAY AS DEEP SOUTHERLY FLOW
PREVAILS AMONGST PARTLY CLOUDY SKIES WHILE MOSTLY CLOUDY SKIES
COMBINE WITH PRECIPITATION TO KEEP HIGHS A FEW DEGREES BELOW NORMAL
FOR TUESDAY. BY WEDNESDAY MORNING...THE FRONT WILL BE EXITING TO
THE EAST ALLOWING FOR POPS TO TREND DOWN...ALONG WITH TEMPS. LOWS
ON WEDNESDAY MORNING WILL REMAIN AT OR JUST BELOW NORMAL ACROSS THE
LOWER TERRAIN WHERE THE FROPA OCCURS LATER...WHILE THE HIGH TERRAIN
WILL SEE LOWS ON THE ORDER OF 5 DEGREES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM SAT...A BROAD TROUGH WILL BE IN PLACE ACROSS THE ERN
TWO THIRDS OF THE CONUS ON WED AS A DEEP LOW PRESSURE SYSTEM SPINS
OVER ERN CANADA AND THE NRN GREAT LAKES. DEEP LAYER DRYING IS
EXPECTED ON WEDNESDAY BEHIND THE SLOWLY DEPARTING/STALLING COLD
FRONT...WITH MAINLY NW FLOW ACROSS THE REGION. WEAK SFC HIGH PRES
WILL BUILD OVER FROM THE N...AND MAX TEMPS SHOULD DIP TO TWO
CATEGORIES BELOW NORMAL BY WED AFTN. AS THE WEAK HIGH SETTLES INTO
PLACE TO OUR N...LOW LEVEL EASTERLY FLOW COULD DEVELOP INTO THE SRN
APPALACHIANS BY THU. IT IS QUESTIONABLE HOW MUCH MOISTURE WILL
RETURN TO THE PROFILES...BUT SLIGHTLY IMPROVED BL RH COULD HELP
TRIGGER ISOLD TO SCT AFTN SHOWERS...ESPECIALLY IN AND NEAR THE MTNS.
MAX TEMPS LOOK TO BE A SOLID 5 TO 10 DEGREES BELOW NORMAL THU
AFTN...POSSIBLY MORE IF WE CLOUD UP QUICKER.
THOUGH SUBTLE MODEL DIFFERENCES EXIST BY LATE WEEK...THERE IS
REASONABLE CONSENSUS REGARDING SHORTWAVE ENERGY DIVING THROUGH THE
SRN PLAINS INTO THE BROAD TROUGH ON THU...AND THEN MOVING TO THE
BASE OF THE SRN APPALACHIANS BY FRI. THIS MAY BRING A WEAK SFC
REFLECTION AND ADDITIONAL MOISTURE BACK TO THE REGION...INTERACTING
WITH THE WEAK SFC HIGH TO THE NORTH AND POSSIBLY PROVIDING SOME
DEGREE OF COLD AIR DAMMING FRI INTO SAT. WILL KEEP MAXES WELL BELOW
NORMAL DURING THIS PERIOD...WITH MAINLY CHC POPS...HIGHEST NEAR THE
BLUE RIDGE.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
AT KCLT...VERY QUIET PATTERN WILL REMAIN ACROSS THE TERMINAL THROUGH
THE TAF PERIOD. THE FORECAST WILL FEATURE SSW WINDS WITH VFR
CLOUDS...PRIMARILY SCT BETWEEN 040-060KFT. I WILL HIGHLIGHT THE
POTENTIAL FOR MVFR HAZE WITH A TEMPO FROM 10Z-14Z. WINDS SHOULD VEER
FROM THE SW AN HOUR OR TWO AFTER SUNRISE SUNDAY.
ELSEWHERE...CONDITIONS WILL BE VERY SIMILAR TO CLT. KAVL WILL
MAINTAIN DEWPOINTS IN THE MID 60 THROUGH LATE TONIGHT. BASED ON
FORECAST TEMPERATURES...THE XOVER TEMPERATURE SHOULD BE SLIGHTLY
EXCEEDED LATE TONIGHT. I WILL BASE THE TIMING OF SUB-IFR VIS AND
CEILINGS ON SAT MORNING OBS AND FORECAST SOUNDINGS. KHKY WILL MAY
SEE A PERIOD OF DAWN MVFR FOG...OTHERWISE VFR.
OUTLOOK...RESTRICTIONS IN THUNDERSTORMS ARE POSSIBLE MONDAY AND
TUESDAY. UNLIMITED CEILING AND UNRESTRICTED VISIBILITY WILL RETURN
ON WEDNESDAY FOLLOWING COLD FRONTAL PASSAGE.
CONFIDENCE TABLE...
02-08Z 08-14Z 14-20Z 20-02Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL HIGH 85% MED 73% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 86% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...LGL/NED
SHORT TERM...CDG
LONG TERM...HG
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
750 PM EDT SAT JUL 12 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL LINGER OVER THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA THE REST OF THE WEEKEND. AN UNSEASONABLY STRONG
COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST ON MONDAY AND
CROSS THE REGION TUESDAY. COOLER THAN NORMAL TEMPERATURES WILL
ARRIVE FROM MID TO LATE WEEK BEHIND THE FRONT.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 740 PM...THE FORECAST TRENDS LOOK GOOD. I WILL UPDATE TO
ADJUST SKY AND TEMPERATURES TO OBSERVATIONS. CONDITIONS LOOK
FAVORABLE FOR MTN VALLEY FOG TONIGHT...A LITTLE LESS COVERAGE AND
DURATION THAN THIS MORNING. KCAE RADAR INDICATES THAT A SEA BREEZE
BOUNDARY WAS TRACKING STEADILY WEST. SOME PATCHY FOG IS POSSIBLE IN
THE WAKE OF THE BOUNDARY...GENERALLY ACROSS THE MIDLANDS.
AS 530 PM...THE CURRENT FORECAST REMAINS IN GREAT SHAPE. SCT
CONVECTION OVER THE MTNS HAS TRENDED WEAKER OVER THE PAST HOUR...BUT
COVERAGE HAS REMAINED NEARLY UNCHANGED. I WILL UPDATE THE FORECAST
TO ALIGN SKY WITH SATELLITE OBSERVATIONS AND TO TWEAK TEMPS.
OTHERWISE...CHANGES TO FORECAST WILL BE MINOR.
AT 245 PM EDT SATURDAY... CURRENT MESOANALYSIS INDICATES CAPES OVER
THE MOUNTAINS ARE AROUND 1500 J/KG AND GENERALLY LESS THAN 1000 J/KG
EAST OF THE MOUNTAINS. RAP FORECAST INTO THE EVENING SHOWS CAPE
PERSISTS FOR A WHILE IN THE FAR WESTERN ZONES... ALIGNED WITH THE
AXIS OF HIGH TERRAIN... BUT CAPE DECREASES SUBSTANTIALLY IN THE
EAST. AS HAS BEEN THE CASE DURING THE PAST COUPLE OF NIGHTS...
ISOLATED CONVECTIVE STORMS MIGHT CONTINUE WELL AFTER SUNSET. VERY
LIGHT WINDS THROUGH A DEEP LAYER COULD RESULT IN SLOWLY MOVING
THUNDERSTORMS AND THE POTENTIAL FOR LOCALLY EXCESSIVE RAINFALL.
OTHERWISE... PRIMARY FEATURE ALOFT AFFECTING OUR WEATHER THROUGH
SUNDAY IS A RIDGE EXTENDING FROM THE WEST COAST ACROSS THE SOUTHERN
STATES TO THE CAROLINAS. AT THE SURFACE... HIGH PRESSURE WITH A VERY
WEAK GRADIENT WILL COVER THE REGION. AS HEIGHTS FALL OVER THE
NORTHERN U.S. ON SUNDAY... THE EASTERN PERIPHERY OF THE UPPER LEVEL
RIDGE WILL WITHDRAW WESTWARD A BIT... BUT THROUGH TOMORROW THE RIDGE
IS GOING TO BE THE PRIMARY PLAYER IN CONTINUING THE CURRENT PERIOD
OF GENERALLY TRANQUIL WEATHER. THE AIR MASS OVER THE WESTERN ZONES
WILL REMAIN FAIRLY MOIST AND MODERATELY UNSTABLE THUS SUPPORTING
SCATTERED SHOWERS AND THUNDERSTORMS WHICH WILL BE MOST NUMEROUS OVER
THE HIGHER TERRAIN. CAPE VALUES EAST OF THE MOUNTAINS ON SUNDAY WILL
BE HELD AT BAY BY A RATHER WARM TEMPERATURE PROFILE. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE... BUT CUMULUS AND TOWERING
CUMULUS SHOULD DOMINATE THE SKY IN OUR PIEDMONT ZONES TOMORROW. LOWS
WILL BE AROUND 70 IN THE PIEDMONT AND IN THE 60S IN THE MOUNTAINS.
HIGHS ON SUNDAY WILL BE FAIRLY CLOSE TO NORMAL... PERHAPS A FEW
DEGREES ABOVE NORMAL AT A FEW LOCATIONS. HIGHS WILL BE AROUND 90
EAST OF THE MOUNTAINS AND IN THE LOWER AND MID 80S IN THE MOUNTAIN
VALLEYS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 230 PM EDT SATURDAY...THE SHORT RANGE PERIOD INITIALIZES
SUNDAY EVENING WITH A BROAD LONGWAVE UPPER TROF ROTATING ACROSS
SOUTHERN ONTARIO. MEANWHILE...BERMUDA HIGH WILL CONTINUE TO ADVECT
WARM/MOIST AIR ACROSS THE SOUTHEAST...NORTHWARD INTO THE MID
ATLANTIC STATES. EXPECTING ONGOING CONVECTION ACROSS THE HIGH
TERRAIN AT FORECAST INITIALIZATION DUE TO IMPROVED INSTABILITY AXIS
AND WEAK SOUTHERLY UPSLOPE FLOW. CHANCE LEVEL POPS WILL BE
FEATURED INITIALLY ACROSS THE HIGH TERRAIN BEFORE TAPERING DOWN TO
SLIGHT CHANCE LEVELS BY DAYBREAK. BY MONDAY MORNING...THE
FIRST...AND WEAKER OF TWO COLD FRONTAL BOUNDARIES WILL APPROACH THE
REGION FROM THE WEST. ADJACENT WEAK UPPER IMPULSE COMBINED WITH
BOUNDARY INTRUSION WILL SPAWN CONVECTION ACROSS THE
MOUNTAINS/FOOTHILLS DURING THE AFTERNOON HOURS ON MONDAY. DUE TO
THE SUSTAINED SOUTHERLY FLOW IN DAYS PAST...THE ATMOSPHERE WILL HAVE
RECOVERED ENOUGH TO YIELD A MODERATELY UNSTABLE WARM SECTOR AHEAD OF
THIS FRONT. THUS...EXPECTING SHOWERS AND THUNDERSTORMS TO SPILL OUT
OF THE HIGH TERRAIN AND PROPAGATE EAST INTO THE PIEDMONT/FOOTHILLS
MONDAY EVENING. AS SAID ABOVE...SUBSTANTIAL CAPE WILL BE PRESENT TO
SUPPORT SOME DEEPER UPDRAFTS LEADING TO A FEW STRONG/SEVERE
THUNDERSTORMS MONDAY AFTERNOON/EVENING...DESPITE WEAKER YET
IMPROVING SHEAR. FORECAST WILL FEATURE LIKELY POPS ACROSS THE
MAJORITY OF THE MOUNTAIN/FOOTHILLS ZONES WHILE LOWER CHANCE POPS ARE
HIGHLIGHTED SOUTH EASTWARD ACROSS NORTHEAST GA AND THE NC/SC
PIEDMONTS.
TUESDAY MORNING THE ABOVE MENTIONED BOUNDARY WILL HAVE ESSENTIALLY
DISSIPATED AND BECOME STATIONARY ACROSS CENTRAL NC...SOUTHWARD
INTO THE MIDLANDS OF SC. AT THE SAME TIME THE RATHER
DEEP/IMPRESSIVE UPPER LOW WILL ROTATE DOWN ACROSS THE GREAT LAKES
WHILE SURFACE CYCLOGENESIS OCCURS ALONG THE EASTERN SEABOARD. THE
STRONG COLD FRONT WILL BE PUSHING THROUGH THE OHIO VALLEY BY EARLY
MORNING...EASTWARD INTO THE CENTRAL/SOUTHERN APPS BY MID/LATE
MORNING...THEN FINALLY FURTHER EAST INTO THE PIEDMONT REGIONS ON
TUESDAY AFTERNOON/EVENING. EXPECTING THE ABOVE MENTIONED SURFACE
CYCLONE TO DEEPEN SLIGHTLY AND AID IN DEVELOPMENT OF A LEE SIDE
TROF ACROSS THE PIEDMONT/COASTAL PLAINS OF NC LATE IN THE
AFTERNOON. THIS WEAK/DIFFUSE BOUNDARY COULD PROVIDE A FOCUS FOR
SURFACE CONVERGENCE AHEAD OF THE APPROACHING/STRONG COLD FRONT.
THERE WILL BE SUFFICIENT UPPER SUPPORT...SHEAR...AND BUOYANCY IN
PLACE TO SUPPORT ORGANIZED STRONG/SEVERE CONVECTION ACROSS THE
ENTIRE REGION ON TUESDAY. THE FORECAST WILL FEATURE WIDESPREAD
LIKELY POPS FOR TUESDAY ENCOMPASSING THE ENTIRE REGION. WILL
CONTINUE WITH SEVERE THUNDERSTORM POSSIBLE WORDING IN THE HWO FOR
BOTH MONDAY EVENING/OVERNIGHT...AND THROUGH THE DAY ON TUESDAY.
TEMPERATURES WILL BE ABOVE NORMAL ON MONDAY AS DEEP SOUTHERLY FLOW
PREVAILS AMONGST PARTLY CLOUDY SKIES WHILE MOSTLY CLOUDY SKIES
COMBINE WITH PRECIPITATION TO KEEP HIGHS A FEW DEGREES BELOW NORMAL
FOR TUESDAY. BY WEDNESDAY MORNING...THE FRONT WILL BE EXITING TO
THE EAST ALLOWING FOR POPS TO TREND DOWN...ALONG WITH TEMPS. LOWS
ON WEDNESDAY MORNING WILL REMAIN AT OR JUST BELOW NORMAL ACROSS THE
LOWER TERRAIN WHERE THE FROPA OCCURS LATER...WHILE THE HIGH TERRAIN
WILL SEE LOWS ON THE ORDER OF 5 DEGREES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM SAT...A BROAD TROUGH WILL BE IN PLACE ACROSS THE ERN
TWO THIRDS OF THE CONUS ON WED AS A DEEP LOW PRESSURE SYSTEM SPINS
OVER ERN CANADA AND THE NRN GREAT LAKES. DEEP LAYER DRYING IS
EXPECTED ON WEDNESDAY BEHIND THE SLOWLY DEPARTING/STALLING COLD
FRONT...WITH MAINLY NW FLOW ACROSS THE REGION. WEAK SFC HIGH PRES
WILL BUILD OVER FROM THE N...AND MAX TEMPS SHOULD DIP TO TWO
CATEGORIES BELOW NORMAL BY WED AFTN. AS THE WEAK HIGH SETTLES INTO
PLACE TO OUR N...LOW LEVEL EASTERLY FLOW COULD DEVELOP INTO THE SRN
APPALACHIANS BY THU. IT IS QUESTIONABLE HOW MUCH MOISTURE WILL
RETURN TO THE PROFILES...BUT SLIGHTLY IMPROVED BL RH COULD HELP
TRIGGER ISOLD TO SCT AFTN SHOWERS...ESPECIALLY IN AND NEAR THE MTNS.
MAX TEMPS LOOK TO BE A SOLID 5 TO 10 DEGREES BELOW NORMAL THU
AFTN...POSSIBLY MORE IF WE CLOUD UP QUICKER.
THOUGH SUBTLE MODEL DIFFERENCES EXIST BY LATE WEEK...THERE IS
REASONABLE CONSENSUS REGARDING SHORTWAVE ENERGY DIVING THROUGH THE
SRN PLAINS INTO THE BROAD TROUGH ON THU...AND THEN MOVING TO THE
BASE OF THE SRN APPALACHIANS BY FRI. THIS MAY BRING A WEAK SFC
REFLECTION AND ADDITIONAL MOISTURE BACK TO THE REGION...INTERACTING
WITH THE WEAK SFC HIGH TO THE NORTH AND POSSIBLY PROVIDING SOME
DEGREE OF COLD AIR DAMMING FRI INTO SAT. WILL KEEP MAXES WELL BELOW
NORMAL DURING THIS PERIOD...WITH MAINLY CHC POPS...HIGHEST NEAR THE
BLUE RIDGE.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT KCLT...VERY QUIET PATTERN WILL REMAIN ACROSS THE TERMINAL THROUGH
THE TAF PERIOD. THE FORECAST WILL FEATURE SSW WINDS WITH VFR
CLOUDS...PRIMARILY SCT BETWEEN 040-060KFT. I WILL HIGHLIGHT THE
POTENTIAL FOR MVFR HAZE WITH A TEMPO FROM 10Z-14Z. WINDS SHOULD VEER
FROM THE SW AN HOUR OR TWO AFTER SUNRISE SUNDAY.
ELSEWHERE...CONDITIONS WILL BE VERY SIMILAR TO CLT. KAVL WILL
MAINTAIN DEWPOINTS IN THE MID 60 THROUGH LATE TONIGHT. BASED ON
FORECAST TEMPERATURES...THE XOVER TEMPERATURE SHOULD BE SLIGHTLY
EXCEEDED LATE TONIGHT. I WILL BASE THE TIMING OF SUB-IFR VIS AND
CEILINGS ON SAT MORNING OBS AND FORECAST SOUNDINGS. KHKY WILL MAY
SEE A PERIOD OF DAWN MVFR FOG...OTHERWISE VFR.
OUTLOOK...RESTRICTIONS IN THUNDERSTORMS ARE POSSIBLE MONDAY AND
TUESDAY. UNLIMITED CEILING AND UNRESTRICTED VISIBILITY WILL RETURN
ON WEDNESDAY FOLLOWING COLD FRONTAL PASSAGE.
CONFIDENCE TABLE...
23-05Z 05-11Z 11-17Z 17-23Z
KCLT HIGH 100% HIGH 100% HIGH 94% MED 66%
KGSP HIGH 100% HIGH 100% HIGH 94% MED 66%
KAVL HIGH 100% MED 74% MED 74% MED 66%
KHKY HIGH 100% HIGH 100% HIGH 91% MED 66%
KGMU HIGH 100% HIGH 100% HIGH 94% MED 66%
KAND HIGH 100% HIGH 100% HIGH 80% MED 66%
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...HG
NEAR TERM...LGL/NED
SHORT TERM...CDG
LONG TERM...HG
AVIATION...NED
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
924 PM CDT SAT JUL 12 2014
.UPDATE...
LINE OF LIGHT SHOWERS/EMBEDDED TSRA CONTS TO SLOWLY SAG SOUTH
AHEAD OF COLD FROPA FROM THE NORTH. LATEST RUC SHOWS THAT
CONVECTION HAS FIRED IN WEAK ZONE OF 700HPA THETA-E
FORCING...ALTHOUGH FEEL THAT MOST WAS DIURNALLY DRIVEN AND HAVE
SEEN A WEAKENING AS THE SUN SETS. HAVE UPDATED GRIDS TO ACCOUNT
FOR THIS MINOR LINE SAGGING SOUTH ALONG WITH ASSOCIATED CLOUD
COVER GRIDS. UPDATED ZONE FORECAST PRODUCT ALREADY SENT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
FORECAST CHALLENGE WILL BE TEMPERATURES THROUGHOUT THE SHORT TERM
PERIOD.
CURRENTLY...UNDER PARTLY TO MOSTLY SUNNY SKIES...WINDS ARE LIGHT
AND TEMPERATURES ARE WARMING THROUGH THE 60S...70S AND 80S. A
BROAD AREA OF RAIN SHOWERS IS TRUDGING ACROSS WEST CENTRAL
MINNESOTA.
TONIGHT THROUGH MONDAY NIGHT...A COUPLE OF DRY COLD FRONTAL
PASSAGES WORKING FROM NORTH TO SOUTH WILL BEFALL THE FORECAST
AREA LATER TONIGHT AND THEN AGAIN SUNDAY NIGHT. THIS WILL SET THE
TABLE FOR SOME UNSEASONABLY COOL TEMPERATURES DURING THE EARLY
PART OF THIS UPCOMING WEEK AS A NORTHERN CANADIAN SOURCE-REGIONED
AIRMASS ADVECTS DOWN INTO THE DAKOTAS AND MINNESOTA. ON
MONDAY...IN PARTICULAR...925HPA THERMAL PROGS ARE IN THE LOW TEENS
WHILE 850HPA THERMAL PROGS ARE ONLY IN THE SINGLE DIGITS ACROSS A
GOOD CHUNK OF THE CWA WHICH COULD END UP TRANSLATING INTO SOME
RECORD COOL HIGH TEMPERATURES. IT IS ALSO POSSIBLE THAT A FEW
LOCATIONS COULD TIE OR BREAK LOW TEMPERATURE RECORDS MONDAY
NIGHT/EARLY TUESDAY MORNING.
&&
.CLIMATOLOGY...AN ANOMALOUSLY COLD LOW PRESSURE SYSTEM WILL MOVE
INTO THE UPPER MIDWEST EARLY NEXT WEEK...RESULTING IN THE
POSSIBILITY OF A FEW RECORD COOL MAXIMUM TEMPERATURES ON MONDAY
AND RECORD MINIMUM TEMPERATURES MONDAY NIGHT. SEE BELOW:
MONDAY...RECORD OR NEAR RECORD COOL MAXIMUM TEMPERATURES
FORECAST FOR MONDAY JULY FOURTEENTH...
...LOCATION......FORECAST....RECORD COOL MAXIMUM TEMP...
WHEATON MN.........63..............72 IN 1949
SISSETON...........64..............70 IN 1993
WATERTOWN..........64..............61 IN 1962
ABERDEEN...........66..............65 IN 1962
MOBRIDGE...........68..............64 IN 1962
PIERRE.............70..............65 IN 1989
MONDAY NIGHT...RECORD OR NEAR RECORD MINIMUM TEMPERATURES
FORECAST FOR EARLY TUESDAY MORNING JULY FIFTEENTH...
CITY.........FORECAST TEMP...RECORD TEMP...YEAR SET
ABERDEEN...........49............41..........1912
KENNEBEC...........50............36..........1912
MOBRIDGE...........48............45..........1912
PIERRE.............49............52..........1961
SISSETON...........50............48..........1952
TIMBER LAKE........48............39..........1912
WATERTOWN..........47............38..........1912
WHEATON............50............46..........1924
&&
.LONG TERM...TUESDAY THROUGH SATURDAY
OVERALL THE PATTERN LOOKS FAIRLY BENIGN OVER THE CWA FOR MOST OF
THE PERIOD. UNUSUALLY DEEP MID LEVEL TROF FOR THE TIME OF YEAR
DROPS INTO THE GREAT LAKES AND DRAGS COLDER TO MUCH COLDER THAN
NORMAL AIR DOWN INTO THE NORTHERN PLAINS OUT OF CANADA. 8H TEMPS
IN THE SINGLE DIGITS SUGGESTS SOME PRETTY CHILLY HIGHS FOR THE
EARLY PART OF THE FORECAST. ALSO...ON WEDNESDAY MORNING LOWS MAY
WELL DROP INTO THE 40S UNDER SFC HIGH. CHC OF RAIN AND WARMER
TEMPERATURES RETURN TOWARD THE END OF THE WEEK AS
MOISTURE/INSTABILITY MAKE THEIR WAY BACK NORTH VIA SOUTH WINDS.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. ISOLD TRW-
SOUTH OF KMBG IS NOT EXPECTED TO IMPACT THE KPIR TERMINAL. BECAUSE
OF ABUNDANT LOW LEVEL MOISTURE...PATCHY FOG IS STILL POSSIBLE AFT
06Z...ESPECIALLY FOR THE KABR AND KATY TERMINALS. THAT
SAID...LATEST AFC ANLYS SHOWS MUCH DRIER AIR WORKING SOUTH SO
COULD BE A BIT DIFFICULT FOR PATCHY FOG TO DEVELOP. WILL FOREGO
ANY MENTION ATTM AND MONITOR.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...HINTZ
SHORT TERM...DORN
LONG TERM...TDK
AVIATION...HINTZ
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1229 AM CDT FRI JUL 11 2014
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT
SHORT WAVE TROUGH CLOUD COVER AND SCATTERED LIGHT SHOWERS HAVE
LESSENED THE BUILDUP OF INSTABILITY ACROSS THE REGION LATE THIS
AFTERNOON. THE SPC ANALYSIS SHOWED ONLY 500 TO 1500 J/KG OF MIXED
LAYER CAPE FROM NORTH TO SOUTH ACROSS THE CWA LATE THIS AFTERNOON.
ALTHOUGH...THE DEEP LAYER SHEAR WAS IMPRESSIVE UP TO OVER 50
KNOTS. EXPECT SOME MORE BUILDUP OF INSTABILITY INTO THE EVENING
ACROSS THE CWA AS CLOUDS AND LIGHT SHOWERS MOVE EAST. THE GFS AND
HI-RES MODELS STILL SHOWING NUMEROUS SHOWERS/STORMS DEVELOPING
MAINLY ACROSS THE EASTERN CWA THIS EVENING. CENTRAL SD ALSO SEEING
MORE SUNSHINE AND WARMING LATE THIS AFTERNOON. WITH AN INCREASING
85H LLJ ACROSS MAINLY THE EAST THIS EVENING...EXPECT A GOOD CHANCE
OF SHOWERS/STORMS ACROSS THIS REGION. INCREASED POPS THIS EVENING.
THE MODELS THEN SHOW A WEAK BOUNDARY DROPPING SLOWLY SOUTHEAST
TONIGHT AND FRIDAY BRINGING WINDS AROUND TO THE EAST AND NORTHEAST
ACROSS MOST OF THE CWA. AFTER THE CONVECTION TONIGHT...EXPECT MOST
OF FRIDAY TO NOW BE DRY ACROSS THE CWA. THE MODELS THEN SHOW
ANOTHER SHORT WAVE TROUGH FROM THE NORTHWEST DROPPING ACROSS THE
CWA FRIDAY NIGHT AND SATURDAY ALONG WITH A GOOD JET STREAK
DEVELOPING TO OUR NORTH AND NORTHEAST. THIS WILL PUT US IN THE
FAVORABLE RR QUADRANT. THUS...HAVE IN CHANCES OF MAINLY ELEVATED
SHOWERS/STORMS FOR FRIDAY NIGHT AND SATURDAY WITH EVERYTHING
MOVING OFF TO THE SOUTHEAST SATURDAY NIGHT. HIGHS WILL BE IN THE
80S ON FRIDAY AND A FEW DEGREES COOLER ON SATURDAY.
.LONG TERM...SUNDAY THROUGH THURSDAY
SUNDAY SHOULD PROVE TO BE THE WARMEST DAY OF THE EXTENDED FORECAST
PERIOD...WITH ANOMALOUSLY COOL AIR ADVECTING DOWN INTO THE CWA
MONDAY AND STICKING AROUND THROUGH PROBABLY WEDNESDAY...AT LEAST.
THIS SHOULD SPELL SOME MUCH BELOW NORMAL TEMPERATURES THROUGHOUT
THE PERIOD AND DRY CONDITIONS THROUGHOUT THE PERIOD. COLD AIR
INSTABILITY CU/STRATO-CU WILL LIKELY ONLY ADD INSULT TO INJURY ON
MONDAY CLOUDING THINGS UP AND KEEPING JULY INSOLATION FROM TAKING
THE EDGE OFF THE COLDNESS OF THE AIR ON MONDAY.
&&
.CLIMATOLOGICALLY...
AN ANOMALOUSLY COLD LOW PRESSURE SYSTEM WILL MOVE INTO UPPER
MIDWEST EARLY NEXT WEEK. THE COMBINATION OF A COOL CANADIAN
AIRMASS ALONG WITH INCREASING CLOUDS AND A CHANCE FOR SHOWERS
COULD RESULT IN A FEW RECORD LOW HIGH TEMPERATURES ON MONDAY.
BELOW IS A LIST OF LOCATIONS THAT COULD SEE NEAR RECORD COLD
READINGS ON MONDAY:
...LOCATION......FORECAST....RECORD LOW HIGH TEMP...
WHEATON MN 64 72 IN 1949
SISSETON 65 70 IN 1993
WATERTOWN 65 61 IN 1962
ABERDEEN 67 65 IN 1962
MOBRIDGE 69 64 IN 1962
PIERRE 72 65 IN 1989
&&
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
THUNDERSTORMS CONTINUE TO BE A THREAT THROUGH THE OVERNIGHT HOURS
AS A LOW LEVEL JET STRENGTHENS. THE BEST CHANCES FOR THUNDER
REMAIN FROM SOUTH CENTRAL SOUTH DAKOTA THROUGH NORTHEAST SOUTH
DAKOTA...MAINLY FORECAST TO POSSIBLY IMPACT THE KATY TAF SITE.
BEYOND BRIEF PERIODS OF REDUCED CIGS/VSBYS ASSOCIATED WITH
STRONGER STORMS...MVFR/IRF CIGS AND VSBYS ARE ALSO POSSIBLE AT THE
KATY TAF SITE. THE WARM MOIST AIRMASS IN PLACE WILL LIKELY RESULT IN
LOWER CLOUDS AND THE POTENTIAL FOR PATCHY FOG DEVELOPMENT THROUGH
THE EARLY MORNING HOURS. FRIDAY...A WEAK COLD FRONT WILL SLIDE
FROM NORTHWEST TO SOUTHEAST ACROSS THE STATE OF SOUTH DAKOTA.
WINDS WILL SWITCH AROUND TO THE EAST NORTHEAST BEHIND THE FRONT.
ADDITIONAL SHOWERS AND THUNDERSTORMS ARE POSSIBLE ALONG THE
BOUNDARY AND IN CONJUNCTION WITH UPPER LEVEL ENERGY FRIDAY NIGHT.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...DORN
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
641 PM CDT SAT JUL 12 2014...CORRECTED
.UPDATED...
UPDATED FOR ADDING RAIN CHANCES ACROSS THE WEST THROUGH EARLY
EVENING.
&&
.DISCUSSION...
A FEW POP UP THUNDERSHOWERS HAVE DEVELOP OVER NORTHEAST ARKANSAS
AND THE BOOTHEEL OF MISSOURI IN THE HIGH CENTER OVER THE PAST
HOUR. THIS ACTIVITY IS LIKELY TO CONTINUE INTO THE 7-9PM TIME
FRAME WITH THE LINGERING SOLAR HEATING. ALSO AS A RESULT CLOUD
COVER HAS INCREASED IN THIS REGION. HAVE ADJUSTED THE EVENING
FORECAST ACCORDINGLY.
JAB
&&
.PREV DISCUSSION... /ISSUED 632 PM CDT SAT JUL 12 2014/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 326 PM CDT SAT JUL 12 2014/
DISCUSSION...
TONIGHT INTO TUESDAY...
VERY ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE
FORECAST AREA...95 PERCENT OF THE FORECAST WILL SEE NOTHING FROM
THESE...BUT AS THEY ARE DEVELOPING ON RADAR HAVE ADDED PRE-FIRST
PERIOD ISOLATED STORMS TO THE GRIDS. HRRR 3KM MODEL SHOWED THESE
STARTING TO DEVELOP AROUND 20Z...AND THEY DID...MAYBE I SHOULD
"LISTEN" TO THESE NEW HI-RES MODELS AFTER ALL...THOUGHT THE
DRY AIR ALOFT WITH THE RIDGING AND THE CAPPING SEEN ON THE
FORECAST SOUNDINGS ABOVE 700MB WOULD KEEP STORMS FROM
OCCURRING...BUT NOT TODAY AS I GUESS IT WAS OVERCOME WITH THE CAPES
PUSHING 3.5 TO 4.5K J/KG. PRECIP ENDS SHORTLY AFTER SUNSET WITH THE
LOSS OF HEATING AND CLOUDS WILL MOSTLY DISSIPATE WITH CLEAR TO
MOSTLY CLEAR SKIES.
MODELS STILL SHOWING THE WARMER TEMPS FOR TOMORROW WITH DEWPTS
AROUND THE LOWER 70S...PUSHING APPARENT TEMPS INTO THE 100-104
RANGE...OR JUST BELOW THE HEAT ADVISORY CRITERIA...HOTTEST DAY OF
THE YEAR POSSIBLY AND SHOULD BE DRY. THINGS BEGIN TO CHANGE AS WE
MOVE INTO MONDAY...EARLY DURING THE DAY THE DEEP TROUGH WILL START
TO PUSH SOUTH DIGGING INTO THE MIDDLE MS VALLEY...PRE FRONTAL
TROUGH PRECIP POSSIBLE ON MONDAY...SOME CHANCES FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON AND EVENING...ALL DEPENDING ON
CLOUD COVER AND IF ATMOSPHERE GETS WORKED OVER SOME OR NOT ABLE TO
FULLY DESTABILIZE TO CREATE VERY STRONG STORMS...SOMETHING TO
WATCH. CAPES EXCEED 2 TO 3K J/KG AND MODEST SHEAR...NOTHING OVERLY
EXCITING...BUT POSSIBLE STRONG TO SEVERE. DEEP TROUGH AXIS PUSHES
THROUGH OVERNIGHT MONDAY AND DRIVES THE COLD FRONT INTO NORTHERN
MS BY MID AFTN TUESDAY...BEST CHANCES FOR PRECIP EXISTS MONDAY
NIGHT THROUGH MIDDAY TUESDAY FOR MUCH...IF NOT ALL OF THE AREA.
DECREASING THROUGH THE AFTERNOON AND EVENING FROM NORTH TO SOUTH
AND THE BOUNDARY SAGS. NOT THINKING MUCH CHANCE FOR SEVERE STORMS
ON TUESDAY...BUT SOME MODELS DO SHOW DECENT CAPE STILL IN
PLACE...BUT UPPER LEVEL SUPPORT IS ALMOST NIL WITH UPPER LEVEL LOW
IN QUEBEC.
WEDNESDAY INTO NEXT WEEKEND...
MODELS SHOW DRYING ON WEDNESDAY WITH DECENT NORTHERLY FLOW PUSHING
MUCH COOLER AIR INTO THE REGION...HIGHS NEAR 80 TO THE LOWER
80S...NEARLY 10-15 DEGREES BELOW NORMAL. NORTHERLY FLOW CONTINUES
INTO THURSDAY WITH COOLER THAN NORMAL AND LIKELY DRY CONDITIONS.
MODELS DIVERGE SOME AS WE APPROACH THE WEEKEND...SOME STARTING TO
SHOW AN UPPER LEVEL FEATURE MOVE ACROSS THE REGION FRIDAY INTO
SATURDAY AND CREATING SHOWERS AND THUNDERSTORMS. HAVE LOW POPS IN
AS LITTLE CONSISTENCY SEEN THE LAST TWO DAYS WITH HOW THIS WILL
PLAY OUT WITH THE AMPLIFIED PATTERN OVER THE CONUS BREAKING
DOWN. GFS ENSEMBLE MEAN SHOWS THE REGION WET FRIDAY AND
SATURDAY AND THE EURO ALSO THIS AFTN...AND THAT MAYBE THE LIKELY
TREND TOWARDS A WET FORECAST FOR THOSE DAYS. -ABS
&&
.AVIATION...
00Z TAFS
FOLLOWING DISSIPATION OF SCATTERED SHRA/TSRA NORTH OF JBR THROUGH
01Z OR SO... CLEAR SKIES AND LIGHT WINDS WILL PREVAIL THROUGH THE
OVERNIGHT. BRIEF MVFR VSBY POSSIBLE AT MKL AND TUP TOWARD SUNRISE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
641 PM CDT SAT JUL 12 2014
.UPDATED...
UPDATED FOR ADDING RAIN CHANCES ACROSS THE WEST THROUGH EARLY EVENING.
&&
.DISCUSSION...
A FEW POP UP THUNDERSHOWERS HAVE DEVELOP OVER NORTHEAST ARKANSAS
AND THE BOOTHEEL OF MISSOURI IN THE RIDGE CENTER OVER THE PAST
HOUR. THIS ACTIVITY IS LIKELY TO CONTINUE INTO THE 7-9PM TIME
FRAME WITH THE LINGERING SOLAR HEATING. ALSO AS A RESULT CLOUD
COVER HAS INCREASED IN THIS REGION. HAVE ADJUSTED THE EVENING
FORECAST ACCORDINGLY.
JAB
&&
.PREV DISCUSSION... /ISSUED 632 PM CDT SAT JUL 12 2014/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 326 PM CDT SAT JUL 12 2014/
DISCUSSION...
TONIGHT INTO TUESDAY...
VERY ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE
FORECAST AREA...95 PERCENT OF THE FORECAST WILL SEE NOTHING FROM
THESE...BUT AS THEY ARE DEVELOPING ON RADAR HAVE ADDED PRE-FIRST
PERIOD ISOLATED STORMS TO THE GRIDS. HRRR 3KM MODEL SHOWED THESE
STARTING TO DEVELOP AROUND 20Z...AND THEY DID...MAYBE I SHOULD
"LISTEN" TO THESE NEW HI-RES MODELS AFTER ALL...THOUGHT THE
DRY AIR ALOFT WITH THE RIDGING AND THE CAPPING SEEN ON THE
FORECAST SOUNDINGS ABOVE 700MB WOULD KEEP STORMS FROM
OCCURRING...BUT NOT TODAY AS I GUESS IT WAS OVERCOME WITH THE CAPES
PUSHING 3.5 TO 4.5K J/KG. PRECIP ENDS SHORTLY AFTER SUNSET WITH THE
LOSS OF HEATING AND CLOUDS WILL MOSTLY DISSIPATE WITH CLEAR TO
MOSTLY CLEAR SKIES.
MODELS STILL SHOWING THE WARMER TEMPS FOR TOMORROW WITH DEWPTS
AROUND THE LOWER 70S...PUSHING APPARENT TEMPS INTO THE 100-104
RANGE...OR JUST BELOW THE HEAT ADVISORY CRITERIA...HOTTEST DAY OF
THE YEAR POSSIBLY AND SHOULD BE DRY. THINGS BEGIN TO CHANGE AS WE
MOVE INTO MONDAY...EARLY DURING THE DAY THE DEEP TROUGH WILL START
TO PUSH SOUTH DIGGING INTO THE MIDDLE MS VALLEY...PRE FRONTAL
TROUGH PRECIP POSSIBLE ON MONDAY...SOME CHANCES FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON AND EVENING...ALL DEPENDING ON
CLOUD COVER AND IF ATMOSPHERE GETS WORKED OVER SOME OR NOT ABLE TO
FULLY DESTABILIZE TO CREATE VERY STRONG STORMS...SOMETHING TO
WATCH. CAPES EXCEED 2 TO 3K J/KG AND MODEST SHEAR...NOTHING OVERLY
EXCITING...BUT POSSIBLE STRONG TO SEVERE. DEEP TROUGH AXIS PUSHES
THROUGH OVERNIGHT MONDAY AND DRIVES THE COLD FRONT INTO NORTHERN
MS BY MID AFTN TUESDAY...BEST CHANCES FOR PRECIP EXISTS MONDAY
NIGHT THROUGH MIDDAY TUESDAY FOR MUCH...IF NOT ALL OF THE AREA.
DECREASING THROUGH THE AFTERNOON AND EVENING FROM NORTH TO SOUTH
AND THE BOUNDARY SAGS. NOT THINKING MUCH CHANCE FOR SEVERE STORMS
ON TUESDAY...BUT SOME MODELS DO SHOW DECENT CAPE STILL IN
PLACE...BUT UPPER LEVEL SUPPORT IS ALMOST NIL WITH UPPER LEVEL LOW
IN QUEBEC.
WEDNESDAY INTO NEXT WEEKEND...
MODELS SHOW DRYING ON WEDNESDAY WITH DECENT NORTHERLY FLOW PUSHING
MUCH COOLER AIR INTO THE REGION...HIGHS NEAR 80 TO THE LOWER
80S...NEARLY 10-15 DEGREES BELOW NORMAL. NORTHERLY FLOW CONTINUES
INTO THURSDAY WITH COOLER THAN NORMAL AND LIKELY DRY CONDITIONS.
MODELS DIVERGE SOME AS WE APPROACH THE WEEKEND...SOME STARTING TO
SHOW AN UPPER LEVEL FEATURE MOVE ACROSS THE REGION FRIDAY INTO
SATURDAY AND CREATING SHOWERS AND THUNDERSTORMS. HAVE LOW POPS IN
AS LITTLE CONSISTENCY SEEN THE LAST TWO DAYS WITH HOW THIS WILL
PLAY OUT WITH THE AMPLIFIED PATTERN OVER THE CONUS BREAKING
DOWN. GFS ENSEMBLE MEAN SHOWS THE REGION WET FRIDAY AND
SATURDAY AND THE EURO ALSO THIS AFTN...AND THAT MAYBE THE LIKELY
TREND TOWARDS A WET FORECAST FOR THOSE DAYS. -ABS
&&
.AVIATION...
00Z TAFS
FOLLOWING DISSIPATION OF SCATTERED SHRA/TSRA NORTH OF JBR THROUGH
01Z OR SO... CLEAR SKIES AND LIGHT WINDS WILL PREVAIL THROUGH THE
OVERNIGHT. BRIEF MVFR VSBY POSSIBLE AT MKL AND TUP TOWARD SUNRISE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
632 PM CDT SAT JUL 12 2014
.UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 326 PM CDT SAT JUL 12 2014/
DISCUSSION...
TONIGHT INTO TUESDAY...
VERY ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE
FORECAST AREA...95 PERCENT OF THE FORECAST WILL SEE NOTHING FROM
THESE...BUT AS THEY ARE DEVELOPING ON RADAR HAVE ADDED PRE-FIRST
PERIOD ISOLATED STORMS TO THE GRIDS. HRRR 3KM MODEL SHOWED THESE
STARTING TO DEVELOP AROUND 20Z...AND THEY DID...MAYBE I SHOULD
"LISTEN" TO THESE NEW HI-RES MODELS AFTER ALL...THOUGHT THE
DRY AIR ALOFT WITH THE RIDGING AND THE CAPPING SEEN ON THE
FORECAST SOUNDINGS ABOVE 700MB WOULD KEEP STORMS FROM
OCCURRING...BUT NOT TODAY AS I GUESS IT WAS OVERCOME WITH THE CAPES
PUSHING 3.5 TO 4.5K J/KG. PRECIP ENDS SHORTLY AFTER SUNSET WITH THE
LOSS OF HEATING AND CLOUDS WILL MOSTLY DISSIPATE WITH CLEAR TO
MOSTLY CLEAR SKIES.
MODELS STILL SHOWING THE WARMER TEMPS FOR TOMORROW WITH DEWPTS
AROUND THE LOWER 70S...PUSHING APPARENT TEMPS INTO THE 100-104
RANGE...OR JUST BELOW THE HEAT ADVISORY CRITERIA...HOTTEST DAY OF
THE YEAR POSSIBLY AND SHOULD BE DRY. THINGS BEGIN TO CHANGE AS WE
MOVE INTO MONDAY...EARLY DURING THE DAY THE DEEP TROUGH WILL START
TO PUSH SOUTH DIGGING INTO THE MIDDLE MS VALLEY...PRE FRONTAL
TROUGH PRECIP POSSIBLE ON MONDAY...SOME CHANCES FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON AND EVENING...ALL DEPENDING ON
CLOUD COVER AND IF ATMOSPHERE GETS WORKED OVER SOME OR NOT ABLE TO
FULLY DESTABILIZE TO CREATE VERY STRONG STORMS...SOMETHING TO
WATCH. CAPES EXCEED 2 TO 3K J/KG AND MODEST SHEAR...NOTHING OVERLY
EXCITING...BUT POSSIBLE STRONG TO SEVERE. DEEP TROUGH AXIS PUSHES
THROUGH OVERNIGHT MONDAY AND DRIVES THE COLD FRONT INTO NORTHERN
MS BY MID AFTN TUESDAY...BEST CHANCES FOR PRECIP EXISTS MONDAY
NIGHT THROUGH MIDDAY TUESDAY FOR MUCH...IF NOT ALL OF THE AREA.
DECREASING THROUGH THE AFTERNOON AND EVENING FROM NORTH TO SOUTH
AND THE BOUNDARY SAGS. NOT THINKING MUCH CHANCE FOR SEVERE STORMS
ON TUESDAY...BUT SOME MODELS DO SHOW DECENT CAPE STILL IN
PLACE...BUT UPPER LEVEL SUPPORT IS ALMOST NIL WITH UPPER LEVEL LOW
IN QUEBEC.
WEDNESDAY INTO NEXT WEEKEND...
MODELS SHOW DRYING ON WEDNESDAY WITH DECENT NORTHERLY FLOW PUSHING
MUCH COOLER AIR INTO THE REGION...HIGHS NEAR 80 TO THE LOWER
80S...NEARLY 10-15 DEGREES BELOW NORMAL. NORTHERLY FLOW CONTINUES
INTO THURSDAY WITH COOLER THAN NORMAL AND LIKELY DRY CONDITIONS.
MODELS DIVERGE SOME AS WE APPROACH THE WEEKEND...SOME STARTING TO
SHOW AN UPPER LEVEL FEATURE MOVE ACROSS THE REGION FRIDAY INTO
SATURDAY AND CREATING SHOWERS AND THUNDERSTORMS. HAVE LOW POPS IN
AS LITTLE CONSISTENCY SEEN THE LAST TWO DAYS WITH HOW THIS WILL
PLAY OUT WITH THE AMPLIFIED PATTERN OVER THE CONUS BREAKING
DOWN. GFS ENSEMBLE MEAN SHOWS THE REGION WET FRIDAY AND
SATURDAY AND THE EURO ALSO THIS AFTN...AND THAT MAYBE THE LIKELY
TREND TOWARDS A WET FORECAST FOR THOSE DAYS. -ABS
&&
.AVIATION...
00Z TAFS
FOLLOWING DISSIPATION OF SCATTERED SHRA/TSRA NORTH OF JBR THROUGH
01Z OR SO... CLEAR SKIES AND LIGHT WINDS WILL PREVAIL THROUGH THE
OVERNIGHT. BRIEF MVFR VSBY POSSIBLE AT MKL AND TUP TOWARD SUNRISE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
305 AM EDT FRI JUL 11 2014
.SHORT TERM (TODAY AND TONIGHT)...
SURFACE HIGH PRESSURE TO THE NORTH WILL PROVIDE A LOW LEVEL NE
FLOW...WITH A DRY NW FLOW THROUGH THE MID AND UPPER LEVELS. FORECAST
SOUNDINGS IN THE TN VALLEY LOOK PRETTY STABLE TODAY...SO MOST OF THE
AREA SHOULD STAY DRY. SOME CONVECTIVE DEVELOPMENT MAY OCCUR THIS
AFTERNOON IN THE HIGHER TERRAIN OF SW NC AND THE SMOKIES...AS
DEPICTED BY THE RAP AND HRRR. WILL INCLUDE A SLIGHT CHANCE POP IN
THOSE AREAS. ANYTHING THAT DEVELOPS SHOULD DISSIPATE BY 00Z. WILL
HAVE TEMPERATURES TODAY A LITTLE HIGHER THAN YESTERDAY...BUT BELOW
GFS MOS GUIDANCE WHICH SEEMS TOO WARM.
.LONG TERM (SATURDAY THROUGH THURSDAY)...
A FLAT RIDGE OF HIGH PRESSURE WILL BE OVER THE TENNESSEE VALLEY
FOR SATURDAY AND SUNDAY WITH A GRADUAL INCREASE IN
MOISTURE/INSTABILITY. ONLY FORCING FOR CONVECTION WITH BE
OROGRAPHIC..SO WILL HAVE POPS MAINLY OVER THE HIGHER ELEVATIONS.
FOR MONDAY AND TUESDAY...AN UNUSUALLY STRONG UPPER LOW WILL DROP
ACROSS THE GREAT LAKES REGION. STRONG UPPER TROUGHING WILL BE OVER
THE TENNESSEE VALLEY/SOUTHERN APPALACHIANS WITH A COLD FRONT PASSAGE
FOR LATE MONDAY NIGHT/TUESDAY. INCREASING INSTABILITY AHEAD OF THE
BOUNDARY WILL INCREASE THE COVERAGE OF STORMS FOR MONDAY/MONDAY
NIGHT AND TUESDAY. DUE TO THE STRENGTH OF THE FRONT FOR JULY AND
DECENT INSTABILITY...I AM CONCERNED FOR STRONG TO SEVERE STORMS FOR
MONDAY AFTERNOON/EVENING. MAIN CONCERN WILL BE DAMAGING WINDS.
WILL CALL FOR HIGH CHANCE/LIKELY POPS FOR MONDAY AFTERNOON THROUGH
TUESDAY. AS TIMING OF FROPA AND POTENTIAL OF PRE-FRONTAL TROUGH
BECOMES MORE CLEAR...CATEGORICAL POPS WILL LIKELY BE NEEDED.
AN UNSEASONABLY COOL AIRMASS SPILLS INTO THE AREA FOR WEDNESDAY AND
THURSDAY WITH MAINLY DRY CONDITIONS. GENERALLY WENT A DEGREE OR TWO
COOLER THAN GFS MEX HIGHS THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 90 69 93 70 / 10 10 10 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 88 67 91 69 / 10 10 10 10
OAK RIDGE, TN 88 66 91 68 / 10 10 10 10
TRI CITIES AIRPORT, TN 88 63 88 64 / 10 10 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS/DH
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
355 AM CDT Fri Jul 11 2014
.SHORT TERM...
(Today and tonight)
Rain chances return to much of West Central TX today as an
upper-level cyclone that has cut off from the TUTT (tropical upper
tropospheric trough) moves west across the Mexican state of
Coahuila. A slug of deep moisture attendant to this feature is
moving northwest up the Rio Grande Valley and will increase
precipitable water values to as much as 1.70" across the southwest
half of the CWA this morning, with column moisture values dropping a
bit during the afternoon hours through vertical mixing. The HRRR and
WRF-ARW develop isolated convection through mid afternoon across
much of the area, but the best chance of precipitation will reside
southwest of a Sterling City to Junction line. Mid-level cloud cover
will keep temps in the upper 80s to lower 90s across the
southwestern zones today, with mid 90s expected once again across
the Big Country and Heartland.
I do not anticipate a nocturnal flare-up tonight over West Central
TX (like we are currently seeing to our south) given the anticipated
location of the TUTT low. However, a few showers or thunderstorms
may linger into the evening hours, dissipating shortly after sunset.
Overnight lows will again be seasonal, bottoming out in the upper
60s to mid 70s.
So what is this TUTT low? A TUTT low is a cold core cyclone,
typically located near the tropopause (near 200 mb). These features
are not uncommon during the summer and often produce precipitation
during the summer months as they drift to the west along the
southern flank of the subtropical ridge. Per Whitfield and Lyons
(1992), precipitation is favored on the eastern flank of the TUTT
low, albeit skewed to the southeast quadrant.
.LONG TERM...
(Saturday through Thursday)
TUTT will be moving west of West Central Texas Saturday, but
cloudiness in southwest zones, including Crockett county, will keep
temperatures in the lower 90s. Farther north in the Big Country,
highs in the upper 90s are expected.
Upper level high pressure will keep the region dry and warm into
Monday. However a weather pattern change is in store Tuesday on, as
a large upper low develops in the Great Lakes. This will bring West
Central Texas into northwest flow aloft. A cold front also moves in
Tuesday, becoming stationary over the region. This combination will
bring a chance of showers and thunderstorms through Thursday.
Locally heavy rainfall potential exists as precipitable waters
increase 1/2 inch...to 1.5 to 2 inches. Timing of storm complexes is
difficult this far out, so kept rain chances in the 20 to 30 percent
range. Both the EC and GFS models, however, are similar in timing of
the front and the upper pattern change, so there is increasing
confidence in shower and thunderstorm development.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 94 74 96 72 97 / 10 5 5 0 0
San Angelo 92 70 94 71 96 / 20 10 5 0 0
Junction 91 70 94 71 96 / 20 10 5 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Johnson/04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
617 PM CDT SAT JUL 12 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 309 PM CDT SAT JUL 12 2014
MAIN FORECAST CONCERNS ARE ON SEVERE THUNDERSTORM POTENTIAL OVER
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. HOWEVER...THE SEVERE
POTENTIAL APPEARS TO BE DECREASING THIS AFTERNOON AS WIDESPREAD
SHOWERS AND ISOLATED THUNDERSTORMS OVERSPREAD THESE AREAS. THE
MAIN CONCERN IS SHIFTING MORE TOWARD A HEAVY RAIN THREAT FOR LATE
THIS AFTERNOON INTO THIS EVENING.
KEEPING A CLOSE EYE ON THUNDERSTORM DEVELOPMENT ALONG A COLD FRONT
AND UPPER LEVEL DISTURBANCE THIS AFTERNOON. MESOSCALE MODELS
CONTINUE TO FIRE STORMS OVER THESE AREAS LATE THIS AFTERNOON AND
THEN THEY PUSH THIS ACTIVITY TO THE EAST DURING THE EVENING HOURS.
HOWEVER...THE STRONGEST 850 MB MOISTURE TRANSPORT FOCUSED SOUTH AND
EAST OF THE FORECAST AREA. EFFECTIVE BULK SHEAR OF 40 TO 50 KTS AND
MUCAPE VALUES OF 1000-1500 J/KG WOULD SUPPORT SUPERCELL STRUCTURES
OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. ALSO...IF SURFACE
BASED CONVECTION DEVELOPS THERE COULD EVEN BE THE POTENTIAL TO SEE
AN ISOLATED TORNADO. HOWEVER...0-1 KM SHEAR IS VERY WEAK AND WE
WOULD HAVE TO SEE THE SURFACE LOW AND WARM FRONT MAKE IT A LITTLE
FURTHER NORTH TO HAVE TORNADO POTENTIAL. PRECIPITABLE WATER
VALUES AND WARM CLOUD DEPTH CONTINUES TO SUPPORT HEAVY RAINFALL
POTENTIAL...WITH PW VALUES OF 1.5 TO 1.9 AND WARM CLOUD DEPTH OF
3.5 TO 4.0 KM ALONG AND SOUTH OF INTERSTATE 90. THERE IS A
SECONDARY BOUNDARY STRETCHING FROM NORTHWEST WISCONSIN SOUTHWEST
THROUGH THE TWIN CITIES AREA TO THE INTERSTATE 90 CORRIDOR THEN
STRETCHING BACK TO THE WEST. THIS BOUNDARY PUSHES SOUTHEAST VERY
SLOWLY LATE THIS AFTERNOON INTO THIS EVENING AND WE WILL HAVE TO
KEEP AN EYE ON CONVECTION NEAR THIS BOUNDARY. IF IT STALLS THERE
COULD ENOUGH LOCALIZED VORTICITY TO SEE A NON SUPERCELL TORNADO OR
TWO IF SURFACE BASED CONVECTION OCCURS. ALSO...STORMS NEAR THIS
BOUNDARY HAVE BEEN FAIRLY SLOW MOVING AND WOULD HAVE THE POTENTIAL
TO PRODUCE LOCALLY HEAVY RAINFALL. SHOWERS AND THUNDERSTORMS WILL
TAPER OFF AND END THIS EVENING AS A SHORTWAVE TROUGH EXITS THE
REGION.MOSTLY CLOUDY SKIES ARE EXPECTED THROUGH THE EVENING THEN
WE SHOULD SEE A DECREASING CLOUD TREND LATE TONIGHT INTO EARLY
SUNDAY MORNING. PLAN ON OVERNIGHT LOWS IN THE UPPER 50S TO LOWER
60S. A WEAK FRONT WILL SLIDE THROUGH THE AREA TOMORROW BUT WILL
MOSTLY GENERATE SOME CUMULUS ALONG AND SOUTH OF INTERSTATE 90.
FORECAST SOUNDINGS SUGGEST WE COULD BUILD JUST ENOUGH CAPE FOR
AN ISOLATED SHOWER OR THUNDERSTORM SO HAVE ADDED A SLIGHT CHANCE
FOR THIS ACTIVITY DURING THE AFTERNOON HOURS. OTHERWISE...PLAN ON
HIGH TEMPERATURES RANGING FROM THE LOWER 70S OVER NORTH CENTRAL
WISCONSIN TO THE UPPER 70S ACROSS NORTHEAST IOWA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 309 PM CDT SAT JUL 12 2014
A DEEP TROUGH DIVES INTO THE REGION SUNDAY NIGHT THROUGH MONDAY
BRINING UNSEASONABLY COLD TEMPERATURES AND CHANCES FOR SHOWERS TO
THE REGION. 850 MB TEMPERATURES FALL TO AROUND 4 C MONDAY INTO
TUESDAY...SETTING THE STAGE FOR POTENTIAL RECORD COOL HIGH
TEMPERATURES. SCATTERED SHOWERS ARE EXPECTED ACROSS THE AREA ON
MONDAY. WITH THE SHOWERS/CLOUD COVER...TEMPERATURES WILL BE RATHER
CHILLY FOR THIS TIME OF YEAR WITH HIGHS ONLY MAKING IT INTO THE
UPPER 50S TO POSSIBLY AROUND 60 OVER NORTH CENTRAL WISCONSIN.
ELSEWHERE HIGHS WILL ONLY MAKE IT INTO THE 60S. CANNOT RULE OUT
SLIGHTLY WARMER TEMPERATURES OVER PORTIONS OF NORTHEAST IOWA INTO
FAR SOUTHWEST WISCONSIN WHERE HIGHS COULD APPROACH 70. MUCH OF THE
AREAS WILL BE CLOSE TO SEEING RECORD COOL HIGH TEMPERATURES ON
TUESDAY WITH HIGHS ONLY IN THE 60S. SEE CLIMATE SECTION BELOW FOR
FOR RECORD LOWEST HIGH TEMPERATURES FOR MONDAY AND TUESDAY. THE
TROUGH PULLS EAST OF THE REGION TUESDAY NIGHT INTO WEDNESDAY. WE
SHOULD SEE TEMPERATURES START TO MODERATE WEDNESDAY THROUGH
THURSDAY WITH HIGHS CLIMBING BACK INTO THE 70S. HIGH PRESSURE WILL
PROVIDE DRY AND QUIET WEATHER WEDNESDAY THROUGH FRIDAY. FLOW
ALOFT BECOMES ZONAL FOR NEXT WEEKEND AND WE COULD SEE CHANCES FOR
SHOWERS AND THUNDERSTORMS RETURN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 616 PM CDT SAT JUL 12 2014
THE BACK EDGE OF THE SHOWERS IS PROGRESSING STEADILY EAST AND
SHOULD BE PAST OR VERY CLOSE TO BE BEING PAST KLSE BY 00Z AND WILL
SHOW ONLY A VCSH THERE FOR A COUPLE OF HOURS THIS EVENING.
CEILINGS BEHIND THE SHOWERS GO BACK UP TO VFR AND THEN BASED ON
SATELLITE...SHOULD SCATTER OUT BY THE MIDDLE OF THE EVENING.
SKIES THEN EXPECTED TO GO CLEAR OVERNIGHT AND WITH THE
RAIN...CONCERNED ABOUT THE POSSIBILITY OF FOG DEVELOPMENT. IT DOES
NOT LOOK LIKE THE SURFACE WINDS WILL COMPLETELY DECOUPLE AND BOTH
THE 12.18Z NAM AND 12.21Z RAP SOUNDINGS SHOW WINDS OF 15 TO 20
KNOTS JUST ABOVE THE SURFACE. IF THESE WINDS DEVELOP AS
EXPECTED...THEY SHOULD CREATE ENOUGH MIXING AND MAY KEEP THE FOG
FROM FORMING. FOR NOW...WILL STAY WITH THE PREVIOUS TRENDS OF
SHOWING MVFR VISIBILITY AT KRST WHERE THE SKIES WILL CLEAR OUT
FIRST WITH NO RESTRICTIONS AT KLSE. SECONDARY COLD FRONT WILL
COME THROUGH SUNDAY MORNING SWINGING THE WINDS AROUND TO THE
NORTHWEST AND ENOUGH MIXING BEHIND THIS FOR SOME GUSTS TO AROUND
20 KNOTS AT KRST SUNDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 309 PM CDT SAT JUL 12 2014
A FEW STRONGER THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY
DOWNPOURS WITH RAINFALL RATES OF 1-2 INCHES PER HOUR THIS
AFTERNOON INTO EARLY THIS EVENING. THIS WILL LEAD TO PONDING OF
WATER AND LOCALIZED FLOODING IS POSSIBLE...ESPECIALLY IN URBAN
AREAS.
&&
.CLIMATE...
ISSUED AT 309 PM CDT SAT JUL 12 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE MONDAY AND TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI RIVER
VALLEY.
FOR LA CROSSE...
MONDAY....FORECAST HIGH 69. RECORD 65 IN 1994
TUESDAY...FORECAST HIGH 68. RECORD 68 IN 1962
FOR ROCHESTER...
MONDAY....FORECAST HIGH 64. RECORD 64 IN 1952
TUESDAY...FORECAST HIGH 67. RECORD 67 IN 1962
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
HYDROLOGY...WETENKAMP
CLIMATE...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1250 PM CDT FRI JUL 11 2014
.UPDATE...
ISSUED AT 844 AM CDT FRI JUL 11 2014
FORECAST HAS BEEN UPDATED TO RAISE POPS CONSIDERABLY THROUGH THE
MORNING HOURS AS THE REMNANTS OF AN OVERNIGHT CONVECTIVE SYSTEM
TRACK TO THE EAST THROUGH THE REGION...PARTICULARLY IN SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. INSTABILITY REMAINS FAIRLY
WEAK...SO ANY THUNDERSTORMS SHOULD REMAIN FAIRLY ISOLATED. NOT
SURE HOW MUCH ACTIVITY WILL REDEVELOP IN THE AFTERNOON AS THIS
FEATURE MOVES OFF TO THE EAST BY THIS AFTERNOON. TEMPERATURES WILL
REMAIN DOWN DUE TO THE CLOUD COVER AND RAIN THIS MORNING...BUT
COULD MAKE A BRIEF REBOUND IN THE LATE AFTERNOON HOURS...SO HAVE
ADJUSTED THAT PART OF THE FORECAST AS WELL. UPDATES COMING
SHORTLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL U.S....A WEAK RIDGE OVER MICHIGAN...
A SHORTWAVE TROUGH CROSSING MN WITH THE CORE NEAR DULUTH...A WEAK
SHORTWAVE CROSSING NEBRASKA...AND A DEEP UPPER TROUGH OVER SOUTH
CENTRAL CANADA. DPVA AHEAD OF THE MN SHORTWAVE TROUGH COMBINED WITH
850MB MOISTURE TRANSPORT SEEN BY STRONGER 850MB WINDS ON RADARS FROM
EASTERN SOUTH DAKOTA INTO NORTHERN MN HAS SUPPORTED SHOWERS AND
STORMS NORTH OF MINNEAPOLIS. THE NEBRASKA SHORTWAVE AND ANOTHER NOSE
OF 850MB MOISTURE TRANSPORT HAS SUPPORTED OTHER SHORTWAVES AND
STORMS FROM NEBRASKA INTO SIOUX FALLS AREA. THE FORECAST AREA
MEANWHILE HAS ONLY SEEN A FEW LIGHT SHOWERS WEST OF THE MS RIVER
STEMMING FROM ACCAS CLOUDS ON THE EASTERN EXTENT OF THE MOISTURE
TRANSPORT ZONE. THE AIRMASS OVER THE REGION HAS CERTAINLY BECOME
WARMER AND MORE MOIST OVER THE PAST 24 HOURS. 850MB TEMPS HAVE
CLIMBED TO 12-15C ACCORDING TO 00Z SOUNDINGS WITH 20-25C READINGS IN
THE DAKOTAS. MEANWHILE...PRECIPITABLE WATER VALUES ARE UP TO 1-1.5
INCHES WITH A 2 INCH MAXIMA NEAR SIOUX FALLS PER RAP AND GOES
DERIVED.
THE FORECAST FOR TODAY IS RADICALLY DRIER THAN WHAT IT LOOKED LIKE
24 HOURS AGO. MUCH OF THIS IS A FUNCTION OF THE 850MB MOISTURE
TRANSPORT BEING INCORRECT. INSTEAD OF THE NOSE COMING RIGHT AT THE
FORECAST AREA...ITS IN NORTHERN MN AND NEAR SIOUX FALLS.
ADDITIONALLY...THE SHORTWAVE TRACKING ACROSS MN IS MOVING FASTER
THAN EARLIER PROJECTIONS.
RE-ANALYZING TODAYS FORECAST. IT APPEARS THE SHOWERS AND STORMS
TAKING PLACE NORTH OF MINNEAPOLIS WILL PROGRESS TO THE EAST THIS
MORNING WITH THE CORE OF THE SHORTWAVE TROUGH...PERHAPS CLIPPING
TAYLOR COUNTY. TO THE WEST...REGARDING THE SHOWERS AND STORMS
CROSSING NEBRASKA AND SIOUX FALLS...THESE MAY MAKE IT INTO NORTHEAST
IOWA LATE IN THE MORNING PER HRRR AND 11.00Z GFS PROGS. HOWEVER...
THE 850MB MOISTURE TRANSPORT NOSE SUPPORTING THEM IS PROGGED TO
DRAMATICALLY WEAKEN IN ALL MODELS...SO ITS POSSIBLE THEY DIE BEFORE
REACHING NORTHEAST IOWA. THIS LEAVES REALLY THE ONLY OTHER THREAT OF
PRECIPITATION FOR THE MORNING BEING THIS ACCAS WHICH COULD SHOWER
HERE AND THERE ACROSS MUCH OF THE FORECAST AREA DURING THE MORNING.
HEADING INTO THE AFTERNOON...DESPITE THE FACT THAT THE HIGHER
PRECIPITABLE WATER ZONE OVER SIOUX FALLS AREA IS PROGGED TO SHIFT
EAST INTO THE AREA...THERES NO FORCING TO DO ANYTHING WITH THAT
MOISTURE. SURFACE BOUNDARY WISE...A COLD FRONT LOOKS TO EXTEND
SOUTHWEST TO NORTHEAST ACROSS MN WHILE A WARM FRONT IS ACROSS
NEBRASKA...BOTH BEING WEST OF THE AREA. ADDITIONALLY...500MB HEIGHTS
ARE RISING IN THE WAKE OF THE SHORTWAVE TROUGH TO PROVIDE
SUBSIDENCE. 11.00Z NAM/GFS/REGIONAL CANADIAN ARE ALL DRY AND HAVE
TRENDED THE FORECAST EVEN MORE IN THAT DIRECTION. ONLY THE 11.00Z
HIRES ARW HAS SOME ISOLATED DIURNAL CONVECTION SO KEPT A 20 PERCENT
CHANCE IN CASE. WITH A DRIER FORECAST AND 850MB TEMPS BETWEEN 14-16C
TODAY...HAVE RAISED TEMPERATURES A FEW DEGREES. PLENTY OF MID CLOUD
WILL HAMPER HIGHS FROM REACHING FULL POTENTIAL...THOUGH.
FOR TONIGHT...THERE IS GOOD MODEL AGREEMENT FOR 850MB MOISTURE
TRANSPORT TO INCREASE ACROSS THE CENTRAL PLAINS INTO THE I-80
CORRIDOR ACROSS NEBRASKA AND IOWA. THE CAUSE FOR THE INCREASE IS
TIED TO A FAIRLY STRONG MONSOONAL SHORTWAVE SEEN ON WATER VAPOR
IMAGERY OVER LAS VEGAS...ROTATING UP AROUND THE CENTRAL PLAINS RIDGE
INTO SOUTH DAKOTA BY 12Z SATURDAY. GIVEN THE HIGH PRECIPITABLE WATER
AIRMASS IN PLACE...IT SEEMS ALL BUT CERTAIN SHOWERS AND
THUNDERSTORMS WILL FIRE ON THE NOSE OF THAT 850MB MOISTURE TRANSPORT
ZONE. SOME OF THESE STORMS COULD WORK INTO LOCATIONS SOUTH OF
INTERSTATE 90 AFTER MIDNIGHT...THOUGH BELIEVE THE GREATER FOCUS FOR
THEM WILL OCCUR SOUTH AND WEST OF THE AREA PRIOR TO 12Z SATURDAY.
ALSO CANNOT RULE OUT A FEW SHOWERS AND STORMS THROUGH THE NIGHT
CROSSING TAYLOR/CLARK COUNTIES FROM THE COLD FRONT OVER MN TRACKING
THROUGH THERE. WITH A HIGH PRECIPITABLE WATER AIRMASS IN PLACE AND
MID CLOUD SPREADING IN FROM THE SOUTHWEST...ANTICIPATING A WARM
NIGHT. IN FACT...HIGHER DEWPOINTS ADVECTING IN COULD RESULT IN SOME
FOG.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN LONG TERM CONCERNS ARE ON SEVERE WEATHER POTENTIAL SATURDAY
AFTERNOON/EVENING AND THE UNSEASONABLY COLD AIR MONDAY INTO TUESDAY.
SATURDAYS FOCUS IS ENTIRELY ON THE CURRENT MONSOONAL SHORTWAVE NEAR
LAS VEGAS. MODEL CONSENSUS BRINGS THIS SHORTWAVE THROUGH OUR AREA AT
ABOUT THE TIME OF PEAK HEATING. 0-6KM...0-3KM AND 0-1KM SHEAR VALUES
ALL REALLY INCREASE THROUGH THE DAY IN RESPONSE TO THE SHORTWAVE...
TOPPING OUT AT 21Z AROUND 60 KTS...45 KT AND 20-25 KT RESPECTIVELY.
THIS IS PLENTY FOR ORGANIZED SEVERE CONVECTION. THE DEEPER SHEAR IS
ALSO NICELY CYCLONICALLY CURVED. MEANWHILE...THE ATMOSPHERE IS
JUICED UP PRECIPITABLE WATER WISE WITH VALUES OF 2 INCHES GETTING
ADVECTED INTO THE AREA. ALSO GOOD MODEL CONSENSUS EXISTS FOR 750-
2000 J/KG OF MLCAPE TO BUILD UP SOUTH OF I-90...LIMITED BY PLENTIFUL
CLOUD COVER...WITH EVEN HIGHER VALUES BUILDING UP IN A CAPPED
AIRMASS NEAR I-80. THUS...SEE SOME CHANCE FOR A SEVERE WEATHER EVENT
SATURDAY AFTERNOON. HAIL THREAT IS LIMITED BY THE HIGH PRECIPITABLE
WATER AND WARM CLOUD DEPTHS AROUND 4 KM. THESE PARAMETERS INCREASE
THE HEAVY RAIN AND FLASH FLOODING CONCERN...HOWEVER...THE STRONG
SHEAR SHOULD PROMOTE PROGRESSIVE CONVECTION. ADDITIONALLY...THE
RECENT DRY PERIOD WILL ALLOW SOILS TO ABSORB MORE WATER. THE STRONG
SHEAR DEFINITELY MAKES DAMAGING WINDS A CONCERN. CANNOT RULE OUT A
TORNADO EITHER GIVEN THE 0-1KM SHEAR AND A WARM FRONT LIKELY TO SIT
NEAR/SOUTH OF US-20. REALLY THE ONLY ISSUE WITH SATURDAY AMONGST THE
MODELS IS THE PLACEMENT OF AFTERNOON CONVECTION. THE 11.00Z
NAM/REGIONAL CANADIAN ARE ALONG/NORTH OF I-90...WHICH BOTH HAVE HAD
A NORTHWARD BIAS TO SEVERE CONVECTIVE EVENTS THIS YEAR. PREFER THE
FARTHER SOUTH 11.00Z GFS/ECMWF/HIRES ARW. MUCH OF THE CONVECTION
SHOULD PUSH SOUTHEAST OF THE AREA BY 03Z WITH THE PASSAGE OF THE
SHORTWAVE...FOLLOWED BY SIGNIFICANT DRYING OF PRECIPITABLE WATER OF
NEARLY 1 INCH BY 12Z SUNDAY.
ON SUNDAY...THE DEEP UPPER TROUGH OVER SOUTH CENTRAL CANADA IS
PROGGED TO BEGIN ITS DESCENT INTO OUR REGION. A COLD FRONT AHEAD OF
THE TROUGH SHOULD DROP SOUTH THROUGH THE AREA...AGAIN AT THE TIME OF
PEAK HEATING. 0-6KM SHEAR IS RUNNING 40-50 KT WITH 0-3KM AT 25-35KT.
HOWEVER...INSTABILITY LOOKS TO BE SEVERELY LACKING RESULTING FROM THE
SIGNIFICANT DRYING OF PRECIPITABLE WATER SATURDAY NIGHT. 11.00Z GFS
HAS THE GREATEST INSTABILITY AT 500-1000 J/KG OF MLCAPE...BUT THINK
ITS DEWPOINTS IN THE LOW 60S POOLING AROUND THE BOUNDARY ARE TOO
HIGH. FOR NOW HAVE CONTINUED SOME CHANCES OF PRECIPITATION FOR THE
FRONT...BUT BELIEVE THE DRIER 11.00Z ECMWF/CANADIAN/NAM WILL COME
TRUE. MUCH COOLER AND DRIER AIR SINKS SOUTH INTO THE AREA SUNDAY
NIGHT IN THE WAKE OF THE FRONT.
MONDAY AND TUESDAY STILL LOOK LIKE A TASTE OF FALL AS A SHOT OF
MODIFIED ARCTIC AIR COMES INTO THE REGION. AN UPPER LOW WITHIN THE
DEEP UPPER TROUGH IS PROGGED TO SLIDE ACROSS NORTHERN WI MONDAY
EVENING. COOL TEMPERATURES ALOFT...DAYTIME HEATING AND DPVA AHEAD OF
THE UPPER LOW SHOULD PROMOTE SHOWER DEVELOPMENT ACROSS MUCH OF THE
REGION MONDAY. THIS WILL BE ESPECIALLY TRUE OVER NORTHERN WI. HAVE
RAISED PRECIPITATION CHANCES AND FURTHER INCREASES MAY BE NECESSARY.
PRECIPITATION CHANCES CONTINUE INTO TUESDAY AS WELL WITH THE COLD
AIR ALOFT STILL AROUND. 850MB TEMPERATURES PLUMMET TO 4-6C ON MONDAY
ON A BREEZY NORTHWEST WIND AND HOLD THERE THROUGH TUESDAY. THESE ARE
2-2.5 STANDARD DEVIATIONS BELOW NORMAL SUGGESTING RECORDS ARE
POSSIBLE. SEE CLIMATE SECTION BELOW FOR MORE DETAILS.
THE WEATHER QUIETS DOWN THEN FOR WEDNESDAY AND THROUGH THE END OF
THE WEEK AS THE DEEP UPPER TROUGH GRADUALLY EJECTS OUT. PLENTIFUL
DRY CANADIAN AIR PLUNGES SOUTH THROUGH MUCH OF THE EASTERN U.S....
RESULTING IN A DRY FORECAST FOR WEDNESDAY AND BEYOND. TEMPERATURES
WILL GRADUALLY WARM EACH DAY AS THE SUN HELPS MODIFY THE COLD AIR.
WE SHOULD BE BACK CLOSE TO NORMAL BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1250 PM CDT FRI JUL 11 2014
A BAND OF LIGHT RAIN AND A FEW THUNDERSTORMS WILL MOVE THROUGH THE
TAF REGION EARLY THIS AFTERNOON. THESE SHOWERS LOOK LIKE THEY ARE
MAINLY EAST OF RST ALREADY...SO IT WILL MAINLY BE LSE THAT IS
UNDER THE THREAT OF SEEING SOME BRIEFLY LOWER CONDITIONS TO
MVFR/IFR. AFTER A PERIOD OF VFR THIS AFTERNOON...2-3KFT CLOUD
COVER SHOULD MOVE IN THIS EVENING AHEAD OF THE COLD FRONT AND
REMAIN STUCK OVER THE REGION INTO TOMORROW MORNING. WHILE SOME
SPOTTY RAIN SHOWERS/STORMS ARE POSSIBLE LATE THIS AFTERNOON INTO
TONIGHT...THE NEXT MAIN THREAT IS NOT EXPECTED TO ARRIVE UNTIL
TOMORROW AFTERNOON.
&&
.CLIMATE...
ISSUED AT 255 AM CDT FRI JUL 11 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE ON TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI
RIVER VALLEY. FORECAST HIGH TEMPERATURES FOR TUESDAY ARE 65 AT
ROCHESTER AND 66 AT LA CROSSE. THESE TEMPERATURES WOULD BREAK THE
RECORD LOWEST HIGH TEMPERATURES FOR JULY 15TH. THE OLD RECORDS ARE
68 AT LA CROSSE SET BACK IN 1962 AND 67 AT ROCHESTER ALSO SET
BACK IN 1962.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...AJ
LONG TERM....AJ
AVIATION...HALBACH
CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
844 AM CDT FRI JUL 11 2014
.UPDATE...
ISSUED AT 844 AM CDT FRI JUL 11 2014
FORECAST HAS BEEN UPDATED TO RAISE POPS CONSIDERABLY THROUGH THE
MORNING HOURS AS THE REMNANTS OF AN OVERNIGHT CONVECTIVE SYSTEM
TRACK TO THE EAST THROUGH THE REGION...PARTICULARLY IN SOUTHEAST
MINNESOTA AND WESTERN WISCONSIN. INSTABILITY REMAINS FAIRLY
WEAK...SO ANY THUNDERSTORMS SHOULD REMAIN FAIRLY ISOLATED. NOT
SURE HOW MUCH ACTIVITY WILL REDEVELOP IN THE AFTERNOON AS THIS
FEATURE MOVES OFF TO THE EAST BY THIS AFTERNOON. TEMPERATURES WILL
REMAIN DOWN DUE TO THE CLOUD COVER AND RAIN THIS MORNING...BUT
COULD MAKE A BRIEF REBOUND IN THE LATE AFTERNOON HOURS...SO HAVE
ADJUSTED THAT PART OF THE FORECAST AS WELL. UPDATES COMING
SHORTLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL U.S....A WEAK RIDGE OVER MICHIGAN...
A SHORTWAVE TROUGH CROSSING MN WITH THE CORE NEAR DULUTH...A WEAK
SHORTWAVE CROSSING NEBRASKA...AND A DEEP UPPER TROUGH OVER SOUTH
CENTRAL CANADA. DPVA AHEAD OF THE MN SHORTWAVE TROUGH COMBINED WITH
850MB MOISTURE TRANSPORT SEEN BY STRONGER 850MB WINDS ON RADARS FROM
EASTERN SOUTH DAKOTA INTO NORTHERN MN HAS SUPPORTED SHOWERS AND
STORMS NORTH OF MINNEAPOLIS. THE NEBRASKA SHORTWAVE AND ANOTHER NOSE
OF 850MB MOISTURE TRANSPORT HAS SUPPORTED OTHER SHORTWAVES AND
STORMS FROM NEBRASKA INTO SIOUX FALLS AREA. THE FORECAST AREA
MEANWHILE HAS ONLY SEEN A FEW LIGHT SHOWERS WEST OF THE MS RIVER
STEMMING FROM ACCAS CLOUDS ON THE EASTERN EXTENT OF THE MOISTURE
TRANSPORT ZONE. THE AIRMASS OVER THE REGION HAS CERTAINLY BECOME
WARMER AND MORE MOIST OVER THE PAST 24 HOURS. 850MB TEMPS HAVE
CLIMBED TO 12-15C ACCORDING TO 00Z SOUNDINGS WITH 20-25C READINGS IN
THE DAKOTAS. MEANWHILE...PRECIPITABLE WATER VALUES ARE UP TO 1-1.5
INCHES WITH A 2 INCH MAXIMA NEAR SIOUX FALLS PER RAP AND GOES
DERIVED.
THE FORECAST FOR TODAY IS RADICALLY DRIER THAN WHAT IT LOOKED LIKE
24 HOURS AGO. MUCH OF THIS IS A FUNCTION OF THE 850MB MOISTURE
TRANSPORT BEING INCORRECT. INSTEAD OF THE NOSE COMING RIGHT AT THE
FORECAST AREA...ITS IN NORTHERN MN AND NEAR SIOUX FALLS.
ADDITIONALLY...THE SHORTWAVE TRACKING ACROSS MN IS MOVING FASTER
THAN EARLIER PROJECTIONS.
RE-ANALYZING TODAYS FORECAST. IT APPEARS THE SHOWERS AND STORMS
TAKING PLACE NORTH OF MINNEAPOLIS WILL PROGRESS TO THE EAST THIS
MORNING WITH THE CORE OF THE SHORTWAVE TROUGH...PERHAPS CLIPPING
TAYLOR COUNTY. TO THE WEST...REGARDING THE SHOWERS AND STORMS
CROSSING NEBRASKA AND SIOUX FALLS...THESE MAY MAKE IT INTO NORTHEAST
IOWA LATE IN THE MORNING PER HRRR AND 11.00Z GFS PROGS. HOWEVER...
THE 850MB MOISTURE TRANSPORT NOSE SUPPORTING THEM IS PROGGED TO
DRAMATICALLY WEAKEN IN ALL MODELS...SO ITS POSSIBLE THEY DIE BEFORE
REACHING NORTHEAST IOWA. THIS LEAVES REALLY THE ONLY OTHER THREAT OF
PRECIPITATION FOR THE MORNING BEING THIS ACCAS WHICH COULD SHOWER
HERE AND THERE ACROSS MUCH OF THE FORECAST AREA DURING THE MORNING.
HEADING INTO THE AFTERNOON...DESPITE THE FACT THAT THE HIGHER
PRECIPITABLE WATER ZONE OVER SIOUX FALLS AREA IS PROGGED TO SHIFT
EAST INTO THE AREA...THERES NO FORCING TO DO ANYTHING WITH THAT
MOISTURE. SURFACE BOUNDARY WISE...A COLD FRONT LOOKS TO EXTEND
SOUTHWEST TO NORTHEAST ACROSS MN WHILE A WARM FRONT IS ACROSS
NEBRASKA...BOTH BEING WEST OF THE AREA. ADDITIONALLY...500MB HEIGHTS
ARE RISING IN THE WAKE OF THE SHORTWAVE TROUGH TO PROVIDE
SUBSIDENCE. 11.00Z NAM/GFS/REGIONAL CANADIAN ARE ALL DRY AND HAVE
TRENDED THE FORECAST EVEN MORE IN THAT DIRECTION. ONLY THE 11.00Z
HIRES ARW HAS SOME ISOLATED DIURNAL CONVECTION SO KEPT A 20 PERCENT
CHANCE IN CASE. WITH A DRIER FORECAST AND 850MB TEMPS BETWEEN 14-16C
TODAY...HAVE RAISED TEMPERATURES A FEW DEGREES. PLENTY OF MID CLOUD
WILL HAMPER HIGHS FROM REACHING FULL POTENTIAL...THOUGH.
FOR TONIGHT...THERE IS GOOD MODEL AGREEMENT FOR 850MB MOISTURE
TRANSPORT TO INCREASE ACROSS THE CENTRAL PLAINS INTO THE I-80
CORRIDOR ACROSS NEBRASKA AND IOWA. THE CAUSE FOR THE INCREASE IS
TIED TO A FAIRLY STRONG MONSOONAL SHORTWAVE SEEN ON WATER VAPOR
IMAGERY OVER LAS VEGAS...ROTATING UP AROUND THE CENTRAL PLAINS RIDGE
INTO SOUTH DAKOTA BY 12Z SATURDAY. GIVEN THE HIGH PRECIPITABLE WATER
AIRMASS IN PLACE...IT SEEMS ALL BUT CERTAIN SHOWERS AND
THUNDERSTORMS WILL FIRE ON THE NOSE OF THAT 850MB MOISTURE TRANSPORT
ZONE. SOME OF THESE STORMS COULD WORK INTO LOCATIONS SOUTH OF
INTERSTATE 90 AFTER MIDNIGHT...THOUGH BELIEVE THE GREATER FOCUS FOR
THEM WILL OCCUR SOUTH AND WEST OF THE AREA PRIOR TO 12Z SATURDAY.
ALSO CANNOT RULE OUT A FEW SHOWERS AND STORMS THROUGH THE NIGHT
CROSSING TAYLOR/CLARK COUNTIES FROM THE COLD FRONT OVER MN TRACKING
THROUGH THERE. WITH A HIGH PRECIPITABLE WATER AIRMASS IN PLACE AND
MID CLOUD SPREADING IN FROM THE SOUTHWEST...ANTICIPATING A WARM
NIGHT. IN FACT...HIGHER DEWPOINTS ADVECTING IN COULD RESULT IN SOME
FOG.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN LONG TERM CONCERNS ARE ON SEVERE WEATHER POTENTIAL SATURDAY
AFTERNOON/EVENING AND THE UNSEASONABLY COLD AIR MONDAY INTO TUESDAY.
SATURDAYS FOCUS IS ENTIRELY ON THE CURRENT MONSOONAL SHORTWAVE NEAR
LAS VEGAS. MODEL CONSENSUS BRINGS THIS SHORTWAVE THROUGH OUR AREA AT
ABOUT THE TIME OF PEAK HEATING. 0-6KM...0-3KM AND 0-1KM SHEAR VALUES
ALL REALLY INCREASE THROUGH THE DAY IN RESPONSE TO THE SHORTWAVE...
TOPPING OUT AT 21Z AROUND 60 KTS...45 KT AND 20-25 KT RESPECTIVELY.
THIS IS PLENTY FOR ORGANIZED SEVERE CONVECTION. THE DEEPER SHEAR IS
ALSO NICELY CYCLONICALLY CURVED. MEANWHILE...THE ATMOSPHERE IS
JUICED UP PRECIPITABLE WATER WISE WITH VALUES OF 2 INCHES GETTING
ADVECTED INTO THE AREA. ALSO GOOD MODEL CONSENSUS EXISTS FOR 750-
2000 J/KG OF MLCAPE TO BUILD UP SOUTH OF I-90...LIMITED BY PLENTIFUL
CLOUD COVER...WITH EVEN HIGHER VALUES BUILDING UP IN A CAPPED
AIRMASS NEAR I-80. THUS...SEE SOME CHANCE FOR A SEVERE WEATHER EVENT
SATURDAY AFTERNOON. HAIL THREAT IS LIMITED BY THE HIGH PRECIPITABLE
WATER AND WARM CLOUD DEPTHS AROUND 4 KM. THESE PARAMETERS INCREASE
THE HEAVY RAIN AND FLASH FLOODING CONCERN...HOWEVER...THE STRONG
SHEAR SHOULD PROMOTE PROGRESSIVE CONVECTION. ADDITIONALLY...THE
RECENT DRY PERIOD WILL ALLOW SOILS TO ABSORB MORE WATER. THE STRONG
SHEAR DEFINITELY MAKES DAMAGING WINDS A CONCERN. CANNOT RULE OUT A
TORNADO EITHER GIVEN THE 0-1KM SHEAR AND A WARM FRONT LIKELY TO SIT
NEAR/SOUTH OF US-20. REALLY THE ONLY ISSUE WITH SATURDAY AMONGST THE
MODELS IS THE PLACEMENT OF AFTERNOON CONVECTION. THE 11.00Z
NAM/REGIONAL CANADIAN ARE ALONG/NORTH OF I-90...WHICH BOTH HAVE HAD
A NORTHWARD BIAS TO SEVERE CONVECTIVE EVENTS THIS YEAR. PREFER THE
FARTHER SOUTH 11.00Z GFS/ECMWF/HIRES ARW. MUCH OF THE CONVECTION
SHOULD PUSH SOUTHEAST OF THE AREA BY 03Z WITH THE PASSAGE OF THE
SHORTWAVE...FOLLOWED BY SIGNIFICANT DRYING OF PRECIPITABLE WATER OF
NEARLY 1 INCH BY 12Z SUNDAY.
ON SUNDAY...THE DEEP UPPER TROUGH OVER SOUTH CENTRAL CANADA IS
PROGGED TO BEGIN ITS DESCENT INTO OUR REGION. A COLD FRONT AHEAD OF
THE TROUGH SHOULD DROP SOUTH THROUGH THE AREA...AGAIN AT THE TIME OF
PEAK HEATING. 0-6KM SHEAR IS RUNNING 40-50 KT WITH 0-3KM AT 25-35KT.
HOWEVER...INSTABILITY LOOKS TO BE SEVERELY LACKING RESULTING FROM THE
SIGNIFICANT DRYING OF PRECIPITABLE WATER SATURDAY NIGHT. 11.00Z GFS
HAS THE GREATEST INSTABILITY AT 500-1000 J/KG OF MLCAPE...BUT THINK
ITS DEWPOINTS IN THE LOW 60S POOLING AROUND THE BOUNDARY ARE TOO
HIGH. FOR NOW HAVE CONTINUED SOME CHANCES OF PRECIPITATION FOR THE
FRONT...BUT BELIEVE THE DRIER 11.00Z ECMWF/CANADIAN/NAM WILL COME
TRUE. MUCH COOLER AND DRIER AIR SINKS SOUTH INTO THE AREA SUNDAY
NIGHT IN THE WAKE OF THE FRONT.
MONDAY AND TUESDAY STILL LOOK LIKE A TASTE OF FALL AS A SHOT OF
MODIFIED ARCTIC AIR COMES INTO THE REGION. AN UPPER LOW WITHIN THE
DEEP UPPER TROUGH IS PROGGED TO SLIDE ACROSS NORTHERN WI MONDAY
EVENING. COOL TEMPERATURES ALOFT...DAYTIME HEATING AND DPVA AHEAD OF
THE UPPER LOW SHOULD PROMOTE SHOWER DEVELOPMENT ACROSS MUCH OF THE
REGION MONDAY. THIS WILL BE ESPECIALLY TRUE OVER NORTHERN WI. HAVE
RAISED PRECIPITATION CHANCES AND FURTHER INCREASES MAY BE NECESSARY.
PRECIPITATION CHANCES CONTINUE INTO TUESDAY AS WELL WITH THE COLD
AIR ALOFT STILL AROUND. 850MB TEMPERATURES PLUMMET TO 4-6C ON MONDAY
ON A BREEZY NORTHWEST WIND AND HOLD THERE THROUGH TUESDAY. THESE ARE
2-2.5 STANDARD DEVIATIONS BELOW NORMAL SUGGESTING RECORDS ARE
POSSIBLE. SEE CLIMATE SECTION BELOW FOR MORE DETAILS.
THE WEATHER QUIETS DOWN THEN FOR WEDNESDAY AND THROUGH THE END OF
THE WEEK AS THE DEEP UPPER TROUGH GRADUALLY EJECTS OUT. PLENTIFUL
DRY CANADIAN AIR PLUNGES SOUTH THROUGH MUCH OF THE EASTERN U.S....
RESULTING IN A DRY FORECAST FOR WEDNESDAY AND BEYOND. TEMPERATURES
WILL GRADUALLY WARM EACH DAY AS THE SUN HELPS MODIFY THE COLD AIR.
WE SHOULD BE BACK CLOSE TO NORMAL BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 635 AM CDT FRI JUL 11 2014
FORCING REMAINS WEAK ACROSS THE AREA TODAY AND THE BULK OF THE
MOISTURE AT AND ABOVE 850MB. SCT SHRA EXPECTED TO SPREAD ACROSS THE
TAF SITES THIS MORNING INTO EARLY THIS AFTERNOON BUT MOST VSBYS TO
REMAIN 10SM WITH VFR CIGS. GRADIENT TIGHTENS OVER THE AREA TODAY AND
WITH DIURNAL WARMING/MIXING BRISK/GUSTY SOUTH TO SOUTHWEST WINDS
EXPECTED FOR THE LATE MORNING AND AFTERNOON HOURS TODAY.
MOISTURE CONTINUES TO INCREASE TONIGHT BUT SIGNALS FOR SHRA/TSRA
OVER THE AREA QUITE VARIED. MORE OF A SIGNAL FOR CONVECTION TO FIRE
WEST AND SOUTH OF THE TAF SITES TONIGHT SO LEFT VCTS/VCSH MENTIONS
OUT OF THE KRST/KLSE TAFS FOR NOW GIVEN LOW CONFIDENCE IN ANY SHRA/
TSRA IN THE AREA LATER TONIGHT. WITH THE INCREASING MOISTURE AND
APPROACH OF A SFC FRONT/TROUGH AXIS DID INCREASE THE LOWER CLOUDS
TONIGHT. CARRIED SOME MVFR BR AT KRST AND INCLUDED 4K-5K FT CIGS AT
BOTH KRST/KLSE AFTER 06-07Z FOR NOW.
&&
.CLIMATE...
ISSUED AT 255 AM CDT FRI JUL 11 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE ON TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI
RIVER VALLEY. FORECAST HIGH TEMPERATURES FOR TUESDAY ARE 65 AT
ROCHESTER AND 66 AT LA CROSSE. THESE TEMPERATURES WOULD BREAK THE
RECORD LOWEST HIGH TEMPERATURES FOR JULY 15TH. THE OLD RECORDS ARE
68 AT LA CROSSE SET BACK IN 1962 AND 67 AT ROCHESTER ALSO SET
BACK IN 1962.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
635 AM CDT FRI JUL 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL U.S....A WEAK RIDGE OVER MICHIGAN...
A SHORTWAVE TROUGH CROSSING MN WITH THE CORE NEAR DULUTH...A WEAK
SHORTWAVE CROSSING NEBRASKA...AND A DEEP UPPER TROUGH OVER SOUTH
CENTRAL CANADA. DPVA AHEAD OF THE MN SHORTWAVE TROUGH COMBINED WITH
850MB MOISTURE TRANSPORT SEEN BY STRONGER 850MB WINDS ON RADARS FROM
EASTERN SOUTH DAKOTA INTO NORTHERN MN HAS SUPPORTED SHOWERS AND
STORMS NORTH OF MINNEAPOLIS. THE NEBRASKA SHORTWAVE AND ANOTHER NOSE
OF 850MB MOISTURE TRANSPORT HAS SUPPORTED OTHER SHORTWAVES AND
STORMS FROM NEBRASKA INTO SIOUX FALLS AREA. THE FORECAST AREA
MEANWHILE HAS ONLY SEEN A FEW LIGHT SHOWERS WEST OF THE MS RIVER
STEMMING FROM ACCAS CLOUDS ON THE EASTERN EXTENT OF THE MOISTURE
TRANSPORT ZONE. THE AIRMASS OVER THE REGION HAS CERTAINLY BECOME
WARMER AND MORE MOIST OVER THE PAST 24 HOURS. 850MB TEMPS HAVE
CLIMBED TO 12-15C ACCORDING TO 00Z SOUNDINGS WITH 20-25C READINGS IN
THE DAKOTAS. MEANWHILE...PRECIPITABLE WATER VALUES ARE UP TO 1-1.5
INCHES WITH A 2 INCH MAXIMA NEAR SIOUX FALLS PER RAP AND GOES
DERIVED.
THE FORECAST FOR TODAY IS RADICALLY DRIER THAN WHAT IT LOOKED LIKE
24 HOURS AGO. MUCH OF THIS IS A FUNCTION OF THE 850MB MOISTURE
TRANSPORT BEING INCORRECT. INSTEAD OF THE NOSE COMING RIGHT AT THE
FORECAST AREA...ITS IN NORTHERN MN AND NEAR SIOUX FALLS.
ADDITIONALLY...THE SHORTWAVE TRACKING ACROSS MN IS MOVING FASTER
THAN EARLIER PROJECTIONS.
RE-ANALYZING TODAYS FORECAST. IT APPEARS THE SHOWERS AND STORMS
TAKING PLACE NORTH OF MINNEAPOLIS WILL PROGRESS TO THE EAST THIS
MORNING WITH THE CORE OF THE SHORTWAVE TROUGH...PERHAPS CLIPPING
TAYLOR COUNTY. TO THE WEST...REGARDING THE SHOWERS AND STORMS
CROSSING NEBRASKA AND SIOUX FALLS...THESE MAY MAKE IT INTO NORTHEAST
IOWA LATE IN THE MORNING PER HRRR AND 11.00Z GFS PROGS. HOWEVER...
THE 850MB MOISTURE TRANSPORT NOSE SUPPORTING THEM IS PROGGED TO
DRAMATICALLY WEAKEN IN ALL MODELS...SO ITS POSSIBLE THEY DIE BEFORE
REACHING NORTHEAST IOWA. THIS LEAVES REALLY THE ONLY OTHER THREAT OF
PRECIPITATION FOR THE MORNING BEING THIS ACCAS WHICH COULD SHOWER
HERE AND THERE ACROSS MUCH OF THE FORECAST AREA DURING THE MORNING.
HEADING INTO THE AFTERNOON...DESPITE THE FACT THAT THE HIGHER
PRECIPITABLE WATER ZONE OVER SIOUX FALLS AREA IS PROGGED TO SHIFT
EAST INTO THE AREA...THERES NO FORCING TO DO ANYTHING WITH THAT
MOISTURE. SURFACE BOUNDARY WISE...A COLD FRONT LOOKS TO EXTEND
SOUTHWEST TO NORTHEAST ACROSS MN WHILE A WARM FRONT IS ACROSS
NEBRASKA...BOTH BEING WEST OF THE AREA. ADDITIONALLY...500MB HEIGHTS
ARE RISING IN THE WAKE OF THE SHORTWAVE TROUGH TO PROVIDE
SUBSIDENCE. 11.00Z NAM/GFS/REGIONAL CANADIAN ARE ALL DRY AND HAVE
TRENDED THE FORECAST EVEN MORE IN THAT DIRECTION. ONLY THE 11.00Z
HIRES ARW HAS SOME ISOLATED DIURNAL CONVECTION SO KEPT A 20 PERCENT
CHANCE IN CASE. WITH A DRIER FORECAST AND 850MB TEMPS BETWEEN 14-16C
TODAY...HAVE RAISED TEMPERATURES A FEW DEGREES. PLENTY OF MID CLOUD
WILL HAMPER HIGHS FROM REACHING FULL POTENTIAL...THOUGH.
FOR TONIGHT...THERE IS GOOD MODEL AGREEMENT FOR 850MB MOISTURE
TRANSPORT TO INCREASE ACROSS THE CENTRAL PLAINS INTO THE I-80
CORRIDOR ACROSS NEBRASKA AND IOWA. THE CAUSE FOR THE INCREASE IS
TIED TO A FAIRLY STRONG MONSOONAL SHORTWAVE SEEN ON WATER VAPOR
IMAGERY OVER LAS VEGAS...ROTATING UP AROUND THE CENTRAL PLAINS RIDGE
INTO SOUTH DAKOTA BY 12Z SATURDAY. GIVEN THE HIGH PRECIPITABLE WATER
AIRMASS IN PLACE...IT SEEMS ALL BUT CERTAIN SHOWERS AND
THUNDERSTORMS WILL FIRE ON THE NOSE OF THAT 850MB MOISTURE TRANSPORT
ZONE. SOME OF THESE STORMS COULD WORK INTO LOCATIONS SOUTH OF
INTERSTATE 90 AFTER MIDNIGHT...THOUGH BELIEVE THE GREATER FOCUS FOR
THEM WILL OCCUR SOUTH AND WEST OF THE AREA PRIOR TO 12Z SATURDAY.
ALSO CANNOT RULE OUT A FEW SHOWERS AND STORMS THROUGH THE NIGHT
CROSSING TAYLOR/CLARK COUNTIES FROM THE COLD FRONT OVER MN TRACKING
THROUGH THERE. WITH A HIGH PRECIPITABLE WATER AIRMASS IN PLACE AND
MID CLOUD SPREADING IN FROM THE SOUTHWEST...ANTICIPATING A WARM
NIGHT. IN FACT...HIGHER DEWPOINTS ADVECTING IN COULD RESULT IN SOME
FOG.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN LONG TERM CONCERNS ARE ON SEVERE WEATHER POTENTIAL SATURDAY
AFTERNOON/EVENING AND THE UNSEASONABLY COLD AIR MONDAY INTO TUESDAY.
SATURDAYS FOCUS IS ENTIRELY ON THE CURRENT MONSOONAL SHORTWAVE NEAR
LAS VEGAS. MODEL CONSENSUS BRINGS THIS SHORTWAVE THROUGH OUR AREA AT
ABOUT THE TIME OF PEAK HEATING. 0-6KM...0-3KM AND 0-1KM SHEAR VALUES
ALL REALLY INCREASE THROUGH THE DAY IN RESPONSE TO THE SHORTWAVE...
TOPPING OUT AT 21Z AROUND 60 KTS...45 KT AND 20-25 KT RESPECTIVELY.
THIS IS PLENTY FOR ORGANIZED SEVERE CONVECTION. THE DEEPER SHEAR IS
ALSO NICELY CYCLONICALLY CURVED. MEANWHILE...THE ATMOSPHERE IS
JUICED UP PRECIPITABLE WATER WISE WITH VALUES OF 2 INCHES GETTING
ADVECTED INTO THE AREA. ALSO GOOD MODEL CONSENSUS EXISTS FOR 750-
2000 J/KG OF MLCAPE TO BUILD UP SOUTH OF I-90...LIMITED BY PLENTIFUL
CLOUD COVER...WITH EVEN HIGHER VALUES BUILDING UP IN A CAPPED
AIRMASS NEAR I-80. THUS...SEE SOME CHANCE FOR A SEVERE WEATHER EVENT
SATURDAY AFTERNOON. HAIL THREAT IS LIMITED BY THE HIGH PRECIPITABLE
WATER AND WARM CLOUD DEPTHS AROUND 4 KM. THESE PARAMETERS INCREASE
THE HEAVY RAIN AND FLASH FLOODING CONCERN...HOWEVER...THE STRONG
SHEAR SHOULD PROMOTE PROGRESSIVE CONVECTION. ADDITIONALLY...THE
RECENT DRY PERIOD WILL ALLOW SOILS TO ABSORB MORE WATER. THE STRONG
SHEAR DEFINITELY MAKES DAMAGING WINDS A CONCERN. CANNOT RULE OUT A
TORNADO EITHER GIVEN THE 0-1KM SHEAR AND A WARM FRONT LIKELY TO SIT
NEAR/SOUTH OF US-20. REALLY THE ONLY ISSUE WITH SATURDAY AMONGST THE
MODELS IS THE PLACEMENT OF AFTERNOON CONVECTION. THE 11.00Z
NAM/REGIONAL CANADIAN ARE ALONG/NORTH OF I-90...WHICH BOTH HAVE HAD
A NORTHWARD BIAS TO SEVERE CONVECTIVE EVENTS THIS YEAR. PREFER THE
FARTHER SOUTH 11.00Z GFS/ECMWF/HIRES ARW. MUCH OF THE CONVECTION
SHOULD PUSH SOUTHEAST OF THE AREA BY 03Z WITH THE PASSAGE OF THE
SHORTWAVE...FOLLOWED BY SIGNIFICANT DRYING OF PRECIPITABLE WATER OF
NEARLY 1 INCH BY 12Z SUNDAY.
ON SUNDAY...THE DEEP UPPER TROUGH OVER SOUTH CENTRAL CANADA IS
PROGGED TO BEGIN ITS DESCENT INTO OUR REGION. A COLD FRONT AHEAD OF
THE TROUGH SHOULD DROP SOUTH THROUGH THE AREA...AGAIN AT THE TIME OF
PEAK HEATING. 0-6KM SHEAR IS RUNNING 40-50 KT WITH 0-3KM AT 25-35KT.
HOWEVER...INSTABILITY LOOKS TO BE SEVERELY LACKING RESULTING FROM THE
SIGNIFICANT DRYING OF PRECIPITABLE WATER SATURDAY NIGHT. 11.00Z GFS
HAS THE GREATEST INSTABILITY AT 500-1000 J/KG OF MLCAPE...BUT THINK
ITS DEWPOINTS IN THE LOW 60S POOLING AROUND THE BOUNDARY ARE TOO
HIGH. FOR NOW HAVE CONTINUED SOME CHANCES OF PRECIPITATION FOR THE
FRONT...BUT BELIEVE THE DRIER 11.00Z ECMWF/CANADIAN/NAM WILL COME
TRUE. MUCH COOLER AND DRIER AIR SINKS SOUTH INTO THE AREA SUNDAY
NIGHT IN THE WAKE OF THE FRONT.
MONDAY AND TUESDAY STILL LOOK LIKE A TASTE OF FALL AS A SHOT OF
MODIFIED ARCTIC AIR COMES INTO THE REGION. AN UPPER LOW WITHIN THE
DEEP UPPER TROUGH IS PROGGED TO SLIDE ACROSS NORTHERN WI MONDAY
EVENING. COOL TEMPERATURES ALOFT...DAYTIME HEATING AND DPVA AHEAD OF
THE UPPER LOW SHOULD PROMOTE SHOWER DEVELOPMENT ACROSS MUCH OF THE
REGION MONDAY. THIS WILL BE ESPECIALLY TRUE OVER NORTHERN WI. HAVE
RAISED PRECIPITATION CHANCES AND FURTHER INCREASES MAY BE NECESSARY.
PRECIPITATION CHANCES CONTINUE INTO TUESDAY AS WELL WITH THE COLD
AIR ALOFT STILL AROUND. 850MB TEMPERATURES PLUMMET TO 4-6C ON MONDAY
ON A BREEZY NORTHWEST WIND AND HOLD THERE THROUGH TUESDAY. THESE ARE
2-2.5 STANDARD DEVIATIONS BELOW NORMAL SUGGESTING RECORDS ARE
POSSIBLE. SEE CLIMATE SECTION BELOW FOR MORE DETAILS.
THE WEATHER QUIETS DOWN THEN FOR WEDNESDAY AND THROUGH THE END OF
THE WEEK AS THE DEEP UPPER TROUGH GRADUALLY EJECTS OUT. PLENTIFUL
DRY CANADIAN AIR PLUNGES SOUTH THROUGH MUCH OF THE EASTERN U.S....
RESULTING IN A DRY FORECAST FOR WEDNESDAY AND BEYOND. TEMPERATURES
WILL GRADUALLY WARM EACH DAY AS THE SUN HELPS MODIFY THE COLD AIR.
WE SHOULD BE BACK CLOSE TO NORMAL BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 635 AM CDT FRI JUL 11 2014
FORCING REMAINS WEAK ACROSS THE AREA TODAY AND THE BULK OF THE
MOISTURE AT AND ABOVE 850MB. SCT SHRA EXPECTED TO SPREAD ACROSS THE
TAF SITES THIS MORNING INTO EARLY THIS AFTERNOON BUT MOST VSBYS TO
REMAIN 10SM WITH VFR CIGS. GRADIENT TIGHTENS OVER THE AREA TODAY AND
WITH DIURNAL WARMING/MIXING BRISK/GUSTY SOUTH TO SOUTHWEST WINDS
EXPECTED FOR THE LATE MORNING AND AFTERNOON HOURS TODAY.
MOISTURE CONTINUES TO INCREASE TONIGHT BUT SIGNALS FOR SHRA/TSRA
OVER THE AREA QUITE VARIED. MORE OF A SIGNAL FOR CONVECTION TO FIRE
WEST AND SOUTH OF THE TAF SITES TONIGHT SO LEFT VCTS/VCSH MENTIONS
OUT OF THE KRST/KLSE TAFS FOR NOW GIVEN LOW CONFIDENCE IN ANY SHRA/
TSRA IN THE AREA LATER TONIGHT. WITH THE INCREASING MOISTURE AND
APPROACH OF A SFC FRONT/TROUGH AXIS DID INCREASE THE LOWER CLOUDS
TONIGHT. CARRIED SOME MVFR BR AT KRST AND INCLUDED 4K-5K FT CIGS AT
BOTH KRST/KLSE AFTER 06-07Z FOR NOW.
&&
.CLIMATE...
ISSUED AT 255 AM CDT FRI JUL 11 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE ON TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI
RIVER VALLEY. FORECAST HIGH TEMPERATURES FOR TUESDAY ARE 65 AT
ROCHESTER AND 66 AT LA CROSSE. THESE TEMPERATURES WOULD BREAK THE
RECORD LOWEST HIGH TEMPERATURES FOR JULY 15TH. THE OLD RECORDS ARE
68 AT LA CROSSE SET BACK IN 1962 AND 67 AT ROCHESTER ALSO SET
BACK IN 1962.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
327 AM CDT FRI JUL 11 2014
.TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
SHORT TERM MODELS SHOWING A GENERAL WARM AIR ADVECTION PATTERN
ACROSS THE AREA DURING THIS TIME. 500 MB VORTICITY MAXIMUM OVER
SOUTHERN MINNESOTA HELPING GENERATE SCATTERED LIGHT SHOWERS OR
DRIZZLE ACROSS SOUTHEAST MINNESOTA INTO FAR NORTHERN IOWA. ACTIVITY
FURTHER TO THE WEST DRIVEN MAINLY BY 850 MB LOW LEVEL JET NOSE/WARM
AIR ADVECTION. THIS ACTIVITY WILL TRY TO SHIFT TOWARD THE AREA THIS
MORNING...BUT HRRR SHOWS IT HAVING A HARD TIME GETTING HERE WITH DRY
AIR IN LOW LEVELS.
MAY SEE SOME OF THIS ACTIVITY IN THE AFTERNOON ACROSS SOUTH CENTRAL
WISCONSIN...AS 700 MB MOISTURE INCREASES WITH WEAK ELEVATED CAPE.
KEPT EASTERN AREAS DRY. SHOULD SEE INCREASE IN CLOUDS TODAY...WHICH
MAY HOLD DOWN TEMPERATURES A BIT. 925 MB TEMPERATURE FIELDS SUGGEST
UPPER 70S INLAND...WITH MID 70S TURNING COOLER NEAR THE LAKE WITH
SOUTHEAST WINDS IN THE AFTERNOON.
850 MB LOW LEVEL JET NOSE AND FOCUSED WARM AIR ADVECTION REMAINS
SOUTHWEST AND SOUTH OF THE AREA TONIGHT. AREA FORECAST SOUNDINGS
SHOW ELEVATED CAPES INCREASING GRADUALLY...GETTING UP TO AROUND 700
J/KG IN THE FAR WEST. GENERAL WARM AIR ADVECTION SHOULD CONTINUE TO
BRING IN MOISTURE AT THE 700 MB LEVEL. CONTINUED TO GRADUALLY
INCREASE POPS TONIGHT...HIGHEST IN THE FAR SOUTH AND FAR SOUTHWEST
LATER TONIGHT. LOWS SHOULD REMAIN IN THE MID 60S.
.SATURDAY - CONFIDENCE...MEDIUM
MID LEVEL SHORTWAVE WILL APPROACH. 850 JET INCREASES TOWARDS SRN
WI DURG THE AFTN...ESP ON THE NAM. HOWEVER GFS AND ECMWF ARE
SHOWING A MORE GLANCING SHOT OF THE JETLET WITH THE NAM SHOWING A
MORE DEVELOPED 850 LOW ACROSS NRN WI WITH THE JET AXIS ACROSS
SRN/CNTRL WI. WARM FRONT WILL BE IN THE VCNTY OF SRN WI PER THE
GFS/ECMWF WITH SURFACE COLD FRONT ARRIVING SATURDAY NIGHT. WITH
THE MORE FAVORABLE NORTHWARD TRACK AND DEVELOPMENT SHOWN BY THE
NAM COMES WITH IT THE HIGHER CWASP NUMBERS...WHILE THE GFS AND
ECMWF SHOW LESS IMPRESSIVE NUMBERS. EVEN IN THE LATTER SCENARIO
THERE WILL BE ENOUGH FAVORABLE FACTORS IN PLACE FOR SOME DECENT
STORMS WITH 0-1KM SHEAR INCREASING TO 20 KNOTS AND 0-6KM SHEAR
35-45 KTS. FRONTOGENETICAL FORCING WILL INCREASE WITH TIME. WHILE
SOME DISAGREEMENT BETWEEN THE MODELS ON STORM SEVERITY THE
CONSISTENT MESSAGE IS SOME HEAVY RAINFALL POTENTIAL. PRECIPITABLE
WATER VALUES ON BOTH EXCEED 2 INCHES WITH A WEAKNESS IN CORFIDI
VECTORS LATER SAT AFTN INTO THE EVE HRS. SOME SVR POTENTIAL ON THE
TABLE PER SWODY1 ESP WITH NAM SOLUTION AND HIGHER CWASP BUT HEAVY
RAIN THREAT HAS SOME CONSENSUS AMONGST THE MODELS. SO AT THIS TIME
WILL OPT TO LEAVE SVR OUT OF THE GRIDS BUT MENTION SLGT RISK SVR
AND HEAVY RAIN POTENTIAL IN THE HWO.
.SUNDAY - CONFIDENCE...MEDIUM
WITH THE FRONT TO THE SOUTHEAST NW WINDS WILL USHER IN COOLER 850
TEMPS. THE NAM AND ECMWF ARE SHOWING A DRY SOLUTION WHILE THE GFS
HAS SHRA/ISOLD TSRA WITH A SECONDARY BOUNDARY. UPPER FLOW IS
BROADLY CYCLONIC WITH ANY VORT...MAINLY THE SHEAR/ELONGATED
VARIETY...ACROSS NORTHERN WI. WILL KEEP CHCY POPS FOR NOW BASED ON
COLLAB WITH SURROUNDING OFFICES.
.MONDAY - CONFIDENCE...MEDIUM
MORE PRONOUNCED INTRUSION OF VORTICITY AS LARGE UPPER LOW DRIVES
SOUTHEAST FROM CANADA INTO WISCONSIN. EXPECT BETTER COVERAGE OF
SHRA IN THIS REGIME. ALSO 850 TEMPS CONTINUE TO TAKE A TUMBLE TO
UNDER 10C.
.TUESDAY - CONFIDENCE...MEDIUM
UPPER LOW SHIFTS A BIT EAST INTO
LOWER MI. FLOW ACROSS SRN WI STILL STRONGLY CYCLONIC SO WITH THE GFS
AND ECMWF STILL SHOWING QPF IN THIS REGIME WILL KEEP SHRA POTENTIAL
IN THE FCST. A VERY COOL AIRMASS WILL BE IN PLACE FOR JULY
STANDARDS. 925 TEMPS ONLY MODIFY TO 10-13C IN THE AFTN HRS...WHICH
TRANSLATES TO HIGHS FOR MOST NOT GETTING OUT OF THE MID 60S.
.WEDNESDAY - CONFIDENCE...MEDIUM
UPPER FLOW STILL SHOWING A CYCLONIC CURVATURE THOUGH SURFACE HIGH
DRAWS CLOSER AND AIRMASS DRIES OUT. MAY NEED A SMALL CHANCE AS WE
GET CLOSER BUT FOR NOW WILL GO WITH THE DRY ALLBLEND AND COLLAB
WITH SURROUNDING OFFICES.
.THURSDAY - CONFIDENCE...MEDIUM
LINGERING CYCLONIC FLOW CONTINUES TO LOSE ITS GRIP WITH A DRY AND
WEAKER NORTHWEST FLOW EXPECTED. 925 TEMPS MODIFY A BIT DEEPER INTO
THE TEENS CELSIUS.
&&
.AVIATION/12Z TAFS/...VFR CONDITIONS ARE EXPECTED TODAY INTO MOST OF
TONIGHT. MIDDLE TO HIGH CLOUDS WILL CONTINUE TO INCREASE ACROSS THE
AREA TODAY...AS WARMER AIR MOVES INTO THE REGION. ANY RAIN SHOWER
ACTIVITY SHOULD WEAKEN AS IT MOVES EAST TOWARD MADISON THIS MORNING...
BUT MAY SEE WIDELY SCATTERED ACTIVITY THIS AFTERNOON THERE. NO MENTION
IN TAFS FOR NOW DUE TO LOW AREAL COVERAGE. SOUTH WINDS WILL BECOME
GUSTY AT TIMES AT MADISON TODAY...WITH WINDS SHIFTING SOUTHEAST AT
THE EASTERN SITES THIS AFTERNOON WITH LAKE BREEZE.
LEFT VICINITY SHOWER/THUNDERSTORM WORDING IN TAFS FOR LATER
TONIGHT...AS MORE WARM AND MOIST AIR TRIES TO PUSH INTO THE AREA.
BEST CHANCES WILL REMAIN JUST SOUTH OF THE AREA. MAY SEE LIGHT FOG
DEVELOP WITH MVFR VISIBILITIES LATER TONIGHT ACROSS TAF SITES...AS
WINDS WEAKEN SOMEWHAT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...WOOD
SATURDAY THROUGH THURSDAY...COLLAR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
255 AM CDT FRI JUL 11 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN SHORT TERM CONCERN IS ON PRECIPITATION CHANCES TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE CENTRAL U.S....A WEAK RIDGE OVER MICHIGAN...
A SHORTWAVE TROUGH CROSSING MN WITH THE CORE NEAR DULUTH...A WEAK
SHORTWAVE CROSSING NEBRASKA...AND A DEEP UPPER TROUGH OVER SOUTH
CENTRAL CANADA. DPVA AHEAD OF THE MN SHORTWAVE TROUGH COMBINED WITH
850MB MOISTURE TRANSPORT SEEN BY STRONGER 850MB WINDS ON RADARS FROM
EASTERN SOUTH DAKOTA INTO NORTHERN MN HAS SUPPORTED SHOWERS AND
STORMS NORTH OF MINNEAPOLIS. THE NEBRASKA SHORTWAVE AND ANOTHER NOSE
OF 850MB MOISTURE TRANSPORT HAS SUPPORTED OTHER SHORTWAVES AND
STORMS FROM NEBRASKA INTO SIOUX FALLS AREA. THE FORECAST AREA
MEANWHILE HAS ONLY SEEN A FEW LIGHT SHOWERS WEST OF THE MS RIVER
STEMMING FROM ACCAS CLOUDS ON THE EASTERN EXTENT OF THE MOISTURE
TRANSPORT ZONE. THE AIRMASS OVER THE REGION HAS CERTAINLY BECOME
WARMER AND MORE MOIST OVER THE PAST 24 HOURS. 850MB TEMPS HAVE
CLIMBED TO 12-15C ACCORDING TO 00Z SOUNDINGS WITH 20-25C READINGS IN
THE DAKOTAS. MEANWHILE...PRECIPITABLE WATER VALUES ARE UP TO 1-1.5
INCHES WITH A 2 INCH MAXIMA NEAR SIOUX FALLS PER RAP AND GOES
DERIVED.
THE FORECAST FOR TODAY IS RADICALLY DRIER THAN WHAT IT LOOKED LIKE
24 HOURS AGO. MUCH OF THIS IS A FUNCTION OF THE 850MB MOISTURE
TRANSPORT BEING INCORRECT. INSTEAD OF THE NOSE COMING RIGHT AT THE
FORECAST AREA...ITS IN NORTHERN MN AND NEAR SIOUX FALLS.
ADDITIONALLY...THE SHORTWAVE TRACKING ACROSS MN IS MOVING FASTER
THAN EARLIER PROJECTIONS.
RE-ANALYZING TODAYS FORECAST. IT APPEARS THE SHOWERS AND STORMS
TAKING PLACE NORTH OF MINNEAPOLIS WILL PROGRESS TO THE EAST THIS
MORNING WITH THE CORE OF THE SHORTWAVE TROUGH...PERHAPS CLIPPING
TAYLOR COUNTY. TO THE WEST...REGARDING THE SHOWERS AND STORMS
CROSSING NEBRASKA AND SIOUX FALLS...THESE MAY MAKE IT INTO NORTHEAST
IOWA LATE IN THE MORNING PER HRRR AND 11.00Z GFS PROGS. HOWEVER...
THE 850MB MOISTURE TRANSPORT NOSE SUPPORTING THEM IS PROGGED TO
DRAMATICALLY WEAKEN IN ALL MODELS...SO ITS POSSIBLE THEY DIE BEFORE
REACHING NORTHEAST IOWA. THIS LEAVES REALLY THE ONLY OTHER THREAT OF
PRECIPITATION FOR THE MORNING BEING THIS ACCAS WHICH COULD SHOWER
HERE AND THERE ACROSS MUCH OF THE FORECAST AREA DURING THE MORNING.
HEADING INTO THE AFTERNOON...DESPITE THE FACT THAT THE HIGHER
PRECIPITABLE WATER ZONE OVER SIOUX FALLS AREA IS PROGGED TO SHIFT
EAST INTO THE AREA...THERES NO FORCING TO DO ANYTHING WITH THAT
MOISTURE. SURFACE BOUNDARY WISE...A COLD FRONT LOOKS TO EXTEND
SOUTHWEST TO NORTHEAST ACROSS MN WHILE A WARM FRONT IS ACROSS
NEBRASKA...BOTH BEING WEST OF THE AREA. ADDITIONALLY...500MB HEIGHTS
ARE RISING IN THE WAKE OF THE SHORTWAVE TROUGH TO PROVIDE
SUBSIDENCE. 11.00Z NAM/GFS/REGIONAL CANADIAN ARE ALL DRY AND HAVE
TRENDED THE FORECAST EVEN MORE IN THAT DIRECTION. ONLY THE 11.00Z
HIRES ARW HAS SOME ISOLATED DIURNAL CONVECTION SO KEPT A 20 PERCENT
CHANCE IN CASE. WITH A DRIER FORECAST AND 850MB TEMPS BETWEEN 14-16C
TODAY...HAVE RAISED TEMPERATURES A FEW DEGREES. PLENTY OF MID CLOUD
WILL HAMPER HIGHS FROM REACHING FULL POTENTIAL...THOUGH.
FOR TONIGHT...THERE IS GOOD MODEL AGREEMENT FOR 850MB MOISTURE
TRANSPORT TO INCREASE ACROSS THE CENTRAL PLAINS INTO THE I-80
CORRIDOR ACROSS NEBRASKA AND IOWA. THE CAUSE FOR THE INCREASE IS
TIED TO A FAIRLY STRONG MONSOONAL SHORTWAVE SEEN ON WATER VAPOR
IMAGERY OVER LAS VEGAS...ROTATING UP AROUND THE CENTRAL PLAINS RIDGE
INTO SOUTH DAKOTA BY 12Z SATURDAY. GIVEN THE HIGH PRECIPITABLE WATER
AIRMASS IN PLACE...IT SEEMS ALL BUT CERTAIN SHOWERS AND
THUNDERSTORMS WILL FIRE ON THE NOSE OF THAT 850MB MOISTURE TRANSPORT
ZONE. SOME OF THESE STORMS COULD WORK INTO LOCATIONS SOUTH OF
INTERSTATE 90 AFTER MIDNIGHT...THOUGH BELIEVE THE GREATER FOCUS FOR
THEM WILL OCCUR SOUTH AND WEST OF THE AREA PRIOR TO 12Z SATURDAY.
ALSO CANNOT RULE OUT A FEW SHOWERS AND STORMS THROUGH THE NIGHT
CROSSING TAYLOR/CLARK COUNTIES FROM THE COLD FRONT OVER MN TRACKING
THROUGH THERE. WITH A HIGH PRECIPITABLE WATER AIRMASS IN PLACE AND
MID CLOUD SPREADING IN FROM THE SOUTHWEST...ANTICIPATING A WARM
NIGHT. IN FACT...HIGHER DEWPOINTS ADVECTING IN COULD RESULT IN SOME
FOG.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 255 AM CDT FRI JUL 11 2014
MAIN LONG TERM CONCERNS ARE ON SEVERE WEATHER POTENTIAL SATURDAY
AFTERNOON/EVENING AND THE UNSEASONABLY COLD AIR MONDAY INTO TUESDAY.
SATURDAYS FOCUS IS ENTIRELY ON THE CURRENT MONSOONAL SHORTWAVE NEAR
LAS VEGAS. MODEL CONSENSUS BRINGS THIS SHORTWAVE THROUGH OUR AREA AT
ABOUT THE TIME OF PEAK HEATING. 0-6KM...0-3KM AND 0-1KM SHEAR VALUES
ALL REALLY INCREASE THROUGH THE DAY IN RESPONSE TO THE SHORTWAVE...
TOPPING OUT AT 21Z AROUND 60 KTS...45 KT AND 20-25 KT RESPECTIVELY.
THIS IS PLENTY FOR ORGANIZED SEVERE CONVECTION. THE DEEPER SHEAR IS
ALSO NICELY CYCLONICALLY CURVED. MEANWHILE...THE ATMOSPHERE IS
JUICED UP PRECIPITABLE WATER WISE WITH VALUES OF 2 INCHES GETTING
ADVECTED INTO THE AREA. ALSO GOOD MODEL CONSENSUS EXISTS FOR 750-
2000 J/KG OF MLCAPE TO BUILD UP SOUTH OF I-90...LIMITED BY PLENTIFUL
CLOUD COVER...WITH EVEN HIGHER VALUES BUILDING UP IN A CAPPED
AIRMASS NEAR I-80. THUS...SEE SOME CHANCE FOR A SEVERE WEATHER EVENT
SATURDAY AFTERNOON. HAIL THREAT IS LIMITED BY THE HIGH PRECIPITABLE
WATER AND WARM CLOUD DEPTHS AROUND 4 KM. THESE PARAMETERS INCREASE
THE HEAVY RAIN AND FLASH FLOODING CONCERN...HOWEVER...THE STRONG
SHEAR SHOULD PROMOTE PROGRESSIVE CONVECTION. ADDITIONALLY...THE
RECENT DRY PERIOD WILL ALLOW SOILS TO ABSORB MORE WATER. THE STRONG
SHEAR DEFINITELY MAKES DAMAGING WINDS A CONCERN. CANNOT RULE OUT A
TORNADO EITHER GIVEN THE 0-1KM SHEAR AND A WARM FRONT LIKELY TO SIT
NEAR/SOUTH OF US-20. REALLY THE ONLY ISSUE WITH SATURDAY AMONGST THE
MODELS IS THE PLACEMENT OF AFTERNOON CONVECTION. THE 11.00Z
NAM/REGIONAL CANADIAN ARE ALONG/NORTH OF I-90...WHICH BOTH HAVE HAD
A NORTHWARD BIAS TO SEVERE CONVECTIVE EVENTS THIS YEAR. PREFER THE
FARTHER SOUTH 11.00Z GFS/ECMWF/HIRES ARW. MUCH OF THE CONVECTION
SHOULD PUSH SOUTHEAST OF THE AREA BY 03Z WITH THE PASSAGE OF THE
SHORTWAVE...FOLLOWED BY SIGNIFICANT DRYING OF PRECIPITABLE WATER OF
NEARLY 1 INCH BY 12Z SUNDAY.
ON SUNDAY...THE DEEP UPPER TROUGH OVER SOUTH CENTRAL CANADA IS
PROGGED TO BEGIN ITS DESCENT INTO OUR REGION. A COLD FRONT AHEAD OF
THE TROUGH SHOULD DROP SOUTH THROUGH THE AREA...AGAIN AT THE TIME OF
PEAK HEATING. 0-6KM SHEAR IS RUNNING 40-50 KT WITH 0-3KM AT 25-35KT.
HOWEVER...INSTABILITY LOOKS TO BE SEVERELY LACKING RESULTING FROM THE
SIGNIFICANT DRYING OF PRECIPITABLE WATER SATURDAY NIGHT. 11.00Z GFS
HAS THE GREATEST INSTABILITY AT 500-1000 J/KG OF MLCAPE...BUT THINK
ITS DEWPOINTS IN THE LOW 60S POOLING AROUND THE BOUNDARY ARE TOO
HIGH. FOR NOW HAVE CONTINUED SOME CHANCES OF PRECIPITATION FOR THE
FRONT...BUT BELIEVE THE DRIER 11.00Z ECMWF/CANADIAN/NAM WILL COME
TRUE. MUCH COOLER AND DRIER AIR SINKS SOUTH INTO THE AREA SUNDAY
NIGHT IN THE WAKE OF THE FRONT.
MONDAY AND TUESDAY STILL LOOK LIKE A TASTE OF FALL AS A SHOT OF
MODIFIED ARCTIC AIR COMES INTO THE REGION. AN UPPER LOW WITHIN THE
DEEP UPPER TROUGH IS PROGGED TO SLIDE ACROSS NORTHERN WI MONDAY
EVENING. COOL TEMPERATURES ALOFT...DAYTIME HEATING AND DPVA AHEAD OF
THE UPPER LOW SHOULD PROMOTE SHOWER DEVELOPMENT ACROSS MUCH OF THE
REGION MONDAY. THIS WILL BE ESPECIALLY TRUE OVER NORTHERN WI. HAVE
RAISED PRECIPITATION CHANCES AND FURTHER INCREASES MAY BE NECESSARY.
PRECIPITATION CHANCES CONTINUE INTO TUESDAY AS WELL WITH THE COLD
AIR ALOFT STILL AROUND. 850MB TEMPERATURES PLUMMET TO 4-6C ON MONDAY
ON A BREEZY NORTHWEST WIND AND HOLD THERE THROUGH TUESDAY. THESE ARE
2-2.5 STANDARD DEVIATIONS BELOW NORMAL SUGGESTING RECORDS ARE
POSSIBLE. SEE CLIMATE SECTION BELOW FOR MORE DETAILS.
THE WEATHER QUIETS DOWN THEN FOR WEDNESDAY AND THROUGH THE END OF
THE WEEK AS THE DEEP UPPER TROUGH GRADUALLY EJECTS OUT. PLENTIFUL
DRY CANADIAN AIR PLUNGES SOUTH THROUGH MUCH OF THE EASTERN U.S....
RESULTING IN A DRY FORECAST FOR WEDNESDAY AND BEYOND. TEMPERATURES
WILL GRADUALLY WARM EACH DAY AS THE SUN HELPS MODIFY THE COLD AIR.
WE SHOULD BE BACK CLOSE TO NORMAL BY NEXT WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1120 PM CDT THU JUL 10 2014
REGIONAL RADARS CONTINUE TO SHOW SOME LIGHT SHOWERS MOVING TOWARD
THE AREA BUT SURFACE OBSERVATIONS SHOW LITTLE IF ANYTHING IS
HITTING THE GROUND AND WHAT IS...IS NOTHING MORE THAN SHOWERS.
THESE SHOWERS ARE IN ASSOCIATION WITH A SHORT WAVE TROUGH MOVING
ACROSS NORTHERN MINNESOTA. THE 11.02Z HRRR SHOWS THE MAIN AREA OF
SHOWERS PASSING NORTH OF THE REGION WITH THE SHORT WAVE TROUGH
WITH JUST THE SPRINKLES COMING THROUGH OVERNIGHT AND WILL CONTINUE
TO SHOW A VCSH FOR THIS ACTIVITY WITH VFR CEILINGS. MORE
CONVECTION HAS FORMED OVER NEBRASKA AHEAD OF THE NEXT SHORT WAVE
TROUGH. THIS WAVE IS SHOWN BY THE 11.00Z NAM TO SLIDE SOUTH OF THE
AREA ACROSS IOWA BUT THE ACTIVITY MAY DISSIPATE AS IT APPROACHES.
BOTH THE HRRR AND NAM SHOW THIS HAPPENING AS THE ACTIVITY MOVES
OUT OF THE CAPE AXIS. WITH THIS ACTIVITY EXPECTED TO MISS THE
AREA...WILL DROP THE VCSH BY MID MORNING WHEN THE GRADIENT BECOMES
TIGHT ENOUGH AND THE MIXING GETS GOING TO PRODUCE SOME GUSTY SOUTH
WINDS. LOOK FOR THESE GUSTS TO DIMINISH EARLY FRIDAY EVENING AS
THE LOW LEVEL INVERSION DEVELOPS AND CUTS OFF THE MIXING.
&&
.CLIMATE...
ISSUED AT 255 AM CDT FRI JUL 11 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE ON TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI
RIVER VALLEY. FORECAST HIGH TEMPERATURES FOR TUESDAY ARE 65 AT
ROCHESTER AND 66 AT LA CROSSE. THESE TEMPERATURES WOULD BREAK THE
RECORD LOWEST HIGH TEMPERATURES FOR JULY 15TH. THE OLD RECORDS ARE
68 AT LA CROSSE SET BACK IN 1962 AND 67 AT ROCHESTER ALSO SET
BACK IN 1962.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1120 PM CDT THU JUL 10 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 337 PM CDT THU JUL 10 2014
A SHORTWAVE TROUGH WILL MOVE ACROSS SOUTHERN MINNESOTA/NORTHERN
IOWA THIS EVENING AND EDGE INTO WESTERN SECTIONS OF THE FORECAST
AREA AROUND 00Z. THIS WAVE WILL BRING ISOLATED SHOWERS AND MAYBE A
COUPLE OF THUNDERSTORMS TO THESE AREAS AS IT MOVES IN. THIS
ACTIVITY SHOULD APPROACH THE MISSISSIPPI RIVER LATE THIS EVENING
INTO THE OVERNIGHT HOURS AND WILL INCREASE IN COVERAGE AS 850 MB
MOISTURE TRANSPORT EDGES INTO THE FORECAST AREA. INSTABILITY IS
LIMITED SO HAVE HELD THUNDERSTORM COVERAGE TO ISOLATED UNTIL
FRIDAY MORNING. FORECAST MODELS JUST AREN/T DOING THAT GREAT OF A
JOB HANDLING THIS SHORTWAVE. MESOSCALE MODELS SEEM TO HAVE A
BETTER HANDLE ON THIS WAVE SO HAVE LEANED TOWARDS THEM FOR
PRECIPITATION CHANCES LATE TONIGHT INTO FRIDAY. STRONGER 850 MB
MOISTURE TRANSPORT MOVES INTO THE AREA LATE TOMORROW MORNING INTO
THE AFTERNOON HOURS SO THIS IS WHEN WE SHOULD SEE SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE FORECAST AREA. A WEAK
FRONTAL BOUNDARY THEN SAGS SOUTH INTO THE REGION LATE FRIDAY
AFTERNOON INTO FRIDAY NIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 337 PM CDT THU JUL 10 2014
THE BOUNDARY SETTLES IN FRIDAY NIGHT INTO EARLY SATURDAY MORNING
WITH A VERY BAGGY PRESSURE GRADIENT OVER THE FORECAST AREA. THIS
WEAK GRADIENT COMBINED WITH THE EXPECTED RAIN ON FRIDAY ALONG WITH
DEWPOINTS CLIMBING INTO THE MID TO UPPER 60S WILL SET THE STAGE
FOR FOG DEVELOPMENT. THERE IS SIGNALS IN THE SREF/ARW/NMM FOR
DENSE FOG OVER PORTIONS OF THE FORECAST AREA. IF THESE TRENDS
CONTINUE...FOG COVERAGE WILL NEED TO BE INCREASED AND THERE WOULD
BE THE POTENTIAL TO SEE DENSE FOG. WILL HAVE TO KEEP A VERY CLOSE
EYE ON THIS. THE BOUNDARY THEN EDGES SOUTH SATURDAY AFTERNOON INTO
NORTHEAST IOWA/FAR SOUTHWEST WISCONSIN. AFTERNOON 0-3 KM MUCAPE
VALUES CLIMB INTO THE 1500-1700 J/KG RANGE. 0-6 KM BULK SHEAR
ISN/T ALL THAT GREAT SATURDAY AFTERNOON...RANGING FROM 25 TO 35
KTS. HOWEVER...THERE COULD BE SLIGHTLY STRONGER SHEAR SOUTH OF
INTERSTATE 90 WHERE A SHORTWAVE COULD BE A LITTLER STRONGER THAN
WHAT FORECAST MODELS ARE SUGGESTING. THE MAIN WARM FRONT LOOKS TO
BE POSITIONED OVER CENTRAL IOWA INTO NORTHERN ILLINOIS. THIS AREA
COULD SEE BETTER SHEAR FOR SUPERCELLS AND POSSIBLY SOME TORNADOES
NEAR THE FRONT. ACROSS THE LOCAL AREA...PULSE SEVERE STORMS LOOK
TO BE THE MAIN HAZARD WITH LARGE HAIL AND POSSIBLY DAMAGING WINDS.
LOCALLY HEAVY RAINFALL MAY ALSO BE A CONCERN.
AN UNSEASONABLY DEEP TROUGH DIVES INTO THE REGION LATE SUNDAY
INTO MONDAY NIGHT. THERE IS THE POTENTIAL TO SEE SOME STRONGER TO
POSSIBLY SEVERE STORMS SUNDAY AFTERNOON WITH STRONGER SHEAR OVER
THE REGION. HOWEVER...INSTABILITY WILL BE A MAJOR LIMITING FACTOR.
THE COLDEST AIR WILL SETTLE IN FOR TUESDAY WHEN 850 MB
STANDARDIZED ANOMALIES FALL INTO THE -1.5 TO -2.0 RANGE. TUESDAY
WILL LIKELY BE A DAY FOR RECORD COLD HIGH TEMPERATURES. SEE
CLIMATE SECTION BELOW. TEMPERATURES LOOK TO MODERATE A BIT IN THE
WAKE OF THIS TROUGH WEDNESDAY INTO THURSDAY...WITH HIGHS CLIMBING
BACK INTO THE 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1120 PM CDT THU JUL 10 2014
REGIONAL RADARS CONTINUE TO SHOW SOME LIGHT SHOWERS MOVING TOWARD
THE AREA BUT SURFACE OBSERVATIONS SHOW LITTLE IF ANYTHING IS
HITTING THE GROUND AND WHAT IS...IS NOTHING MORE THAN SHOWERS.
THESE SHOWERS ARE IN ASSOCIATION WITH A SHORT WAVE TROUGH MOVING
ACROSS NORTHERN MINNESOTA. THE 11.02Z HRRR SHOWS THE MAIN AREA OF
SHOWERS PASSING NORTH OF THE REGION WITH THE SHORT WAVE TROUGH
WITH JUST THE SPRINKLES COMING THROUGH OVERNIGHT AND WILL CONTINUE
TO SHOW A VCSH FOR THIS ACTIVITY WITH VFR CEILINGS. MORE
CONVECTION HAS FORMED OVER NEBRASKA AHEAD OF THE NEXT SHORT WAVE
TROUGH. THIS WAVE IS SHOWN BY THE 11.00Z NAM TO SLIDE SOUTH OF THE
AREA ACROSS IOWA BUT THE ACTIVITY MAY DISSIPATE AS IT APPROACHES.
BOTH THE HRRR AND NAM SHOW THIS HAPPENING AS THE ACTIVITY MOVES
OUT OF THE CAPE AXIS. WITH THIS ACTIVITY EXPECTED TO MISS THE
AREA...WILL DROP THE VCSH BY MID MORNING WHEN THE GRADIENT BECOMES
TIGHT ENOUGH AND THE MIXING GETS GOING TO PRODUCE SOME GUSTY SOUTH
WINDS. LOOK FOR THESE GUSTS TO DIMINISH EARLY FRIDAY EVENING AS
THE LOW LEVEL INVERSION DEVELOPS AND CUTS OFF THE MIXING.
&&
.CLIMATE...
ISSUED AT 337 PM CDT THU JUL 10 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE ON TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI
RIVER VALLEY. FORECAST HIGH TEMPERATURES FOR TUESDAY ARE 65 AT
ROCHESTER AND 66 AT LA CROSSE. THESE TEMPERATURES WOULD BREAK THE
RECORD LOWEST HIGH TEMPERATURES FOR JULY 15TH. THE OLD RECORDS ARE
68 AT LA CROSSE SET BACK IN 1962 AND 67 AT ROCHESTER ALSO SET
BACK IN 1962.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
CLIMATE...WETENKAMP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
827 PM MDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 811 PM MDT SAT JUL 12 2014
RECENT RADAR TRENDS SHOW SHOWERS AND TSTMS HAVE INCREASED IN BOTH
COVERAGE AND INTENSITY ACROSS PARTS OF THE CWA THIS EVE. SCATTERED
THUNDERSTORMS WERE LOCATED ALONG A LINE FROM TOR TO NEAR AIA IN
THE NEBRASKA PANHANDLE. THIS IS LIKELY IN RESPONSE TO MIDLVL THETA
E ADVECTION ASSOCIATED WITH A STRONG SHORTWAVE DISTURBANCE PASSING
TO THE N. WEAK FRONTAL BOUNDARY WILL PUSH SOUTH ACROSS THE REST OF
THE AREA INTO THE OVERNIGHT...ENHANCING LLVL CONVERGENCE. THIS
COMBINED WITH THE INCREASE IN INSTABILITY SUGGESTS A CONTINUATION
OF CONVECTIVE ACTIVITY FOR A FEW MORE HOURS. HRRR COMPOSITE RADAR
BASICALLY NAILED THE TIMING AND LOCATION OF THESE STORMS...AND THE
LATEST RUN SHOWS THE SAME ACTIVITY MOVING INTO THE I80 CORRIDOR
AFTER 04Z. LOCALLY HEAVY RAIN AND PERHAPS SOME SMALL HAIL WILL BE
THE PRIMARY THREATS WITH THE VERY MOIST AIR MASS IN PLACE. WENT
AHEAD AND INCREASED POPS INTO THE CHANCE CATEGORY ALONG AND SOUTH
EAST OF A LINE FROM AIA TO CYS. ALSO ADJUSTED CLOUD TRENDS TO
MATCH PCPN COVERAGE. ANVIL BLOWOFF AND MOISTENING LLVLS COULD SLOW
DOWN RADIATIONAL COOLING A BIT...SO INCREASED LOW TEMPS BY A
DEGREE OR TWO AS WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 307 PM MDT SAT JUL 12 2014
NOT NEARLY AS MUCH CONVECTION THIS AFTERNOON WITH MOST OF IT
CONFINED TO AREAS AROUND THE MOUNTAINS NEAR THE COLORADO BORDER.
SATELLITE SUGGESTING A MINOR WAVE MOVING SOUTHEAST OVER THE CWA
PRESENTLY WITH CONVECTION ENDING BEHIND IT. WILL TRIM POPS OVER
THE EASTERN PARTS OF THE CWA THROUGH THIS EVENING GIVEN TRENDS AND
CAPPING EFFECTS THERE. COULD SEE A FEW SHOWERS CURRENTLY COMING
OFF THE BIGHORNS MTNS DRIFT INTO NORTHERN PARTS OF THE CWA BY THIS
EVENING. OTHERWISE QUIET WEATHER EXPECTED OVERALL TONIGHT INTO
SUNDAY MORNING.
NORTHWESTERLY UPPER FLOW WILL PERSIST OVER THE AREA SUNDAY THROUGH
MONDAY WITH WEAK RIPPLES SLIDING SOUTHEAST ACROSS THE AREA AT
TIMES. THESE COMBINED WITH SOME UPSLOPE FLOW AND INSTABILITY
SHOULD ALLOW FOR WIDELY SCTD CONVECTION SUNDAY AFTERNOON AND AGAIN
MONDAY AFTERNOON. BETTER CHANCES WILL EXIST OVER AND CLOSE TO THE
MTNS WHERE UPSLOPE WILL BE ENHANCED WHILE WEAK CAPPING AND LOW
INSTABILITY SHOULD HINDER ACTIVITY FARTHER EAST OVER THE PLAINS.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 307 PM MDT SAT JUL 12 2014
GENERAL WEATHER PATTERN TO REMAIN IN PLACE THROUGH THE EXTENDED
FORECAST PERIOD. TUESDAY STARTS OFF UNDER NORTHWEST FLOW ALOFT.
MODELS IN RELATIVELY GOOD AGREEMENT WITH A SHORTWAVE MOVING ACROSS
THE FORECAST AREA TUESDAY AFTERNOON AND NIGHT. PLENTY OF INSTABILITY
AND FORCING WILL GIVE WAY TO ANOTHER ROUND OF AFTERNOON AND EVENING
THUNDERSTORMS. SEVERE STORM POTENTIAL ON THE LOW SIDE WITH MINIMAL
SHEAR EXPECTED...HOWEVER...HEAVY RAIN MAY AGAIN BE A CONCERN WITH
SOME THUNDERSTORMS. EXPECTING A FEW SHOWERS AND THUNDERSTORMS TO
LINGER LATE INTO TUESDAY NIGHT AS THE SHORTWAVE PASSES THROUGH THE
AREA.
LITTLE CHANGE FOR WEDNESDAY AS THE MODELS ARE SHOWING ANOTHER
POTENTIAL SHORTWAVE MOVING OVER THE AREA. THIS WAVE DOES LOOK WEAKER
THAN TUESDAYS BUT LOOKS LIKE ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS MAINLY IN THE AFTERNOON AND EVENING. AGAIN WIND AND
HAIL THREATS WILL BE MINIMAL BUT SOME HEAVY RAINERS ARE A DECENT
BET. PRECIPITABLE WATER VALUES COULD BE RUNNING FROM 1 INCH TO 1.25
INCHES FOR AREAS EAST OF THE LARAMIE RANGE...AND STORM MOTIONS
SHOULD BE RELATIVELY SLOW. TOUGH TO SAY HOW WIDESPREAD HEAVY RAINS
WILL BE TUESDAY OR WEDNESDAY BUT IT WILL BE SOMETHING TO MONITOR
MORE CLOSELY EARLY NEXT WEEK.
IF THERE IS GOING TO BE A QUIET DAY WEATHER WISE NEXT WEEK IT WOULD
BE THURSDAY AS MODELS SHOWING UPPER LEVEL RIDGING ALOFT OVER THE
CENTRAL ROCKIES. THERE SHOULD BE ENOUGH UPPER LEVEL SUBSIDENCE TO
INHIBIT MOST CONVECTION WITH NOT MUCH MORE THAN ISOLATED AFTERNOON
CONVECTION IN AND AROUND THE MOUNTAINS. RIDGE TO MAINLY STAY IN
PLACE FRIDAY WITH WEAK SHORTWAVE ENERGY POSSIBLE BUT IS LOOKS LIKE
THE NEXT BREAKDOWN OF THE RIDGE WILL COME NEXT WEEKEND AS UPPER
LEVEL ENERGY DIGS SOUTHWARD OUT OF MONTANA. TEMPERATURES THROUGH
MOST OF NEXT WEEK WILL BE BELOW AVERAGE WITH HIGHS GENERALLY IN THE
70S. WARMER TEMPERATURES CLOSER TO NORMAL LATE IN THE WEEK WITH THE
UPPER RIDGE IN PLACE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY AFTERNOON)
ISSUED AT 613 PM MDT SAT JUL 12 2014
LATEST TRENDS IN RADAR AND SATELLITE IMAGERY SHOW A FEW SHOWERS
AND THUNDERSTORMS DEVELOPING NORTH OF A KRWL THROUGH KCDR LINE
THIS EVENING. SHORT TERM MODEL GUIDANCE SUGGESTS THIS
ACTIVITY WILL INCREASE IN COVERAGE AND MOVE SOUTH ACROSS THE
FORECAST AREA THROUGH 06Z. THREFORE...ADDED IN MENTION FOR AT
LEAST VCSH FOR ALL TERMINALS...WITH TS WORDING FOR THE WYO SITES
IN ADDITION TO KCDR WHERE CONFIDENCE IS HIGHEST FOR TSTORM
ACTIVITY. WINDS WILL REMAIN LIGHT THRU THE REMAINDER OF THE
NIGHT...WITH FOG STILL A POSSIBILITY LATE TONIGHT AFTER CONVECTION
CLEARS...ESPECIALLY ALONG AND WEST OF THE LARAMIE RANGE. SHOWERS
AND STORMS LOOK TO DEVELOP ONCE AGAIN FROM KCYS TO KSNY SUNDAY
AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 307 PM MDT SAT JUL 12 2014
CONCERNS TO REMAIN LOW OVER THE NEXT FEW DAYS WITH NON-CRITICAL
CONDITIONS EXPECTED. RECENT RAINS HAVE MOISTENED FUELS OVER MANY
AREAS FURTHER MITIGATING CONCERNS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAMMER
SHORT TERM...RE
LONG TERM...SML
AVIATION...RJM
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
935 PM MST SAT JUL 12 2014
.SYNOPSIS...
MONSOON MOISTURE WILL START TO MOVE WESTWARD BACK OVER THE LOWER
DESERTS ON SUNDAY...BUT THE BEST CHANCES FOR ANY STORMS WILL REMAIN
ACROSS THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX. THE MOISTURE
SURGE WILL OVERTAKE ALL OF THE REGION EARLY NEXT WEEK WITH INCREASED
CHANCES OF THUNDERSTORMS AND SLIGHTLY COOLER TEMPERATURES. NEAR
NORMAL TEMPERATURES AND SLIGHT CHANCES FOR THUNDERSTORMS ARE
FORECAST THROUGH THE REST OF NEXT WEEK.
&&
.DISCUSSION...
THIS EVENING SAW THE BEGINNING OF A TRANSITION TO A MORE ACTIVE
MONSOON PATTERN. CONVECTION DEVELOPED EARLY OVER THE MOGOLLON RIM
AND A SIGNIFICANT INCREASE IN EASTERLY MID-LEVEL FLOW HELPED MAKE
FOR A VALIANT ATTEMPT FOR THIS ACTIVITY TO PUSH INTO THE LOWER
DESERTS. AN EXTREMELY DRY BOUNDARY LAYER AND STABLE AIR IN-PLACE
HOWEVER HELPED TO ERODE THIS ACTIVITY BEFORE IT COULD PUSH VERY FAR
OFF THE HIGH TERRAIN. STRONG GUSTY WINDS HOWEVER DID DEVELOP BEHIND
A COUPLE OUTFLOW BOUNDARIES AND PUSHED SOME BLOWING DUST FROM PINAL
COUNTY INTO THE PHOENIX METROPOLITAN AREA. THE DUST WAS NOT AS DENSE
AS THAT GENERATED BY RECENT STORMS HOWEVER AND THOUGH VISIBILITIES
DID DROP LOCALLY BELOW ONE HALF MILE...THESE RESTRICTIONS DID NOT
LAST LONG. VERY LITTLE RAIN FELL IN THE LOWER DESERTS...THOUGH
DEWPOINTS DID RISE CONSIDERABLY FROM PHOENIX ON EASTWARD.
CURRENTLY ACTIVITY CONTINUES TO DEVELOP OVER GILA AND YAVAPAI
COUNTIES. SOME LIGHT SHOWERS ARE BEGINNING TO WORK THEIR WAY INTO
NORTHERN MARICOPA COUNTY. BIGGEST THREAT WILL CONTINUE TO BE GUSTY
SURFACE WINDS FROM ANY STRONGER SHOWERS OR STORMS THAT DEVELOP.
PRESENTLY THE HRRR HIGH RESOLUTION MODEL SEEMS TO HAVE A GOOD HANDLE
ON THE LOCATION AND TIMING OF CONVECTION THAT IS DEVELOPING. THIS
MODEL CONTINUES TO SHOW SOME PRECIPITATION MOVING INTO THE LOWER
DESERTS THROUGH AROUND 2 AM / 9Z. DECIDED THEREFORE TO KEEP SOME
SLIGHT CHANCE POPS IN THE FORECAST UNTIL THAT TIME.
SEVERAL DEGREES OF COOLING OCCURRED IN THE EASTERN THIRD OF THE
FORECAST AREA WHEN THE BOUNDARIES MOVED THROUGH. MADE SOME MINOR
ADJUSTMENTS THEREFORE TO SUNDAY MINIMUM TEMPERATURES TO ACCOUNT FOR
COOLER EXPECTED READINGS.
TOMORROW AND MONDAY LOOK TO BE ON TRACK AS MORE ACTIVE DAYS. SUNDAY
MIGHT NOT BE QUITE AS ACTIVE HOWEVER IF DEBRIS CLOUDINESS LINGERS
OVERHEAD FOR A GOOD PORTION OF THE DAY.
&&
.PREV DISCUSSION...
ISSUED AT 100 PM MST SAT JUL 12 2014
STORMS BEGINNING TO DEVELOP AS EXPECTED NORTH AND EAST OF
PHOENIX...WITH REGIONAL RADAR IMAGERY INDICATING STORMS FROM NEAR
PAYSON TO SAN CARLOS AS OF 19Z. MEANWHILE ACROSS THE DESERTS...ITS
A VERY TYPICAL MID JULY DAY WITH MOSTLY CLEAR SKIES AND TEMPS IN THE
LOWER 100S. DEWPOINTS HAVE MIXED OUT QUITE A BIT SINCE THIS MORNING
WITH READINGS GENERALLY IN THE UPPER 40S TO LOWER 50S. HIGHS RIGHT
AROUND THE 110 DEGREE MARK STILL LOOK ON TARGET FOR LATER THIS
AFTERNOON AND NO LATE-DAY ADJUSTMENTS APPEAR NECESSARY.
12Z MODELS CONTINUE TO INDICATE STORMS WILL FORM NORTH/EAST OF
PHOENIX THIS AFTERNOON...THEN PROPAGATE OFF THE MOUNTAINS AND INTO A
LARGELY UNFAVORABLE ENVIRONMENT ACROSS THE DESERTS. MLCAPES ARE
FORECAST TO REMAIN AROUND ZERO THANKS MOSTLY TO MIXING RATIOS ONLY
AROUND 5-6 G/KG. THERE IS A VERY NARROW SLIVER OF CAPE FORECAST FROM
AROUND 600-500MB SO IN THEORY THERE COULD BE A FEW STORMS THAT
DEVELOP AS BOUNDARIES COLLIDE...BUT THESE WOULD BE EXTREMELY SHORT
LIVED. WINDS AND DUST WILL BE THE PRIMARY THREATS ACROSS THE DESERTS
TODAY AND I WILL MAINTAIN AREAS OF BLOWING DUST IN THE GRIDS MAINLY
FOR THE EAST VALLEY AND PINAL COUNTY.
THERE WILL BE A SUBTLE INCREASE IN MOISTURE ACROSS THE AREA ON
SUNDAY WITH STORMS ONCE AGAIN FORECAST TO DEVELOP TO THE EAST AND
PROPAGATE INTO THE DESERTS. UNLIKE TODAY...THERE SHOULD BE AT LEAST
SOME INSTABILITY TO WORK WITH ACROSS THE PHOENIX AREA ALTHOUGH
MLCAPES BARELY CREEP ABOVE 100 J/KG. POPS FOR SUNDAY WILL BE
SLIGHTLY HIGHER THAN THOSE FOR TODAY WITH DUST AND WINDS ONCE AGAIN
BEING THE PRIMARY THREATS. STORM ACTIVITY SHOULD AGAIN INITIATE OVER
HIGHER TERRAIN AREAS FIRST SUNDAY AFTERNOON...BUT WITH BETTER
MOISTURE PROFILES AND INCREASED INSTABILITY WE SHOULD SEE SOME
STORMS SURVIVE INTO THE LOWER DESERTS. FORECAST SOUNDINGS STILL SHOW
A FAVORABLE ENVIRONMENT FOR OUTFLOW DEVELOPMENT AND THE POTENTIAL
FOR SOME STRONG WINDS.
BY MONDAY THE FULL FORCE OF THE SOUTHEASTERLY LOW LEVEL FLOW AND
MOISTURE WILL SPREAD WESTWARD THROUGH SOUTHERN ARIZONA INTO
SOUTHEAST CALIFORNIA. PWATS INCREASE TO BETWEEN 1.75 TO 2.00 INCHES
BY MONDAY AFTERNOON WHICH WILL PRESENT MORE OF A HEAVY RAINFALL AND
FLASH FLOODING THREAT AND SLIGHTLY LESS OF A STRONG WIND THREAT. THE
POP FORECAST FOR MONDAY AND TUESDAY BLANKETS MAINLY SLIGHT CHANCES
ACROSS THE LOWER DESERTS AND CHANCES TO THE NORTH AND EAST OF
PHOENIX. TEMPERATURES WILL DROP BACK DOWN TO AROUND SEASONAL NORMALS
WITH BETTER CHANCES OF BEING A FEW DEGREES BELOW NORMAL DUE TO
POTENTIAL SIGNIFICANT CLOUD COVER MONDAY THROUGH WEDNESDAY.
AS THE SUBTROPICAL HIGH CENTER SHIFTS FROM OVER THE GREAT BASIN
EARLY IN THE WEEK TO MAINLY OVER NORTHEAST ARIZONA...WE WILL LOSE
OUR STRONG SOUTHEASTERLY FLOW OF MOISTURE. EVEN THOUGH THE MONSOON
MOISTURE WILL BE SOMEWHAT CUT-OFF...THE REMAINING LEFT OVER MOISTURE
ACROSS ARIZONA WILL CONTINUE TO BRING SLIGHT CHANCES FOR STORMS
MAINLY FROM PHOENIX EASTWARD ON WEDNESDAY. THE GFS SHOWS DRIER
AIR MARCHING ACROSS ARIZONA FROM THE WEST STARTING THURSDAY WHILE
THE EUROPEAN IS A BIT SLOWER AND RETAINS MORE MOISTURE ACROSS THE
REGION. HAVE COMPROMISED BETWEEN THE TWO MODELS AND COME UP WITH
FORECAST POPS MAINLY FOCUSED TO THE NORTH AND EAST OF PHOENIX FOR
THURSDAY AND FRIDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...THUNDERSTORMS
AND SHOWERS DEVELOPING OVER THE HIGHER TERRAIN WILL KEEP BROKEN TO
OVERCAST SKIES OVER MOST OF SOUTH-CENTRAL ARIZONA THROUGH SUNDAY
MORNING. CEILINGS WILL BE AOA 15 KFT. WINDS WILL BE GENERALLY 5 TO
10 KTS...THOUGH DIRECTION WILL BE VARIABLE AND DICTATED BY
BOUNDARIES THAT PROPAGATE FROM DEVELOPING STORMS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
HIGH CLOUDINESS AOA 25 KFT IS EXPECTED THROUGH SUNDAY MORNING. WINDS
ARE EXPECTED TO BE VARIABLE AND LESS THAN 10 KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SURGE OF RENEWED MONSOON MOISTURE WILL AFFECT THE DISTRICT EARLY
IN THE WEEK LEADING TO SIGNIFICANTLY INCREASED CHANCES OF SHOWERS
AND THUNDERSTORMS...HIGHER HUMIDITIES...AND SLIGHTLY LOWER AFTERNOON
HIGH TEMPERATURES. THE BEST OPPORTUNITY FOR WETTING RAIN WILL OCCUR
EARLY IN THE WEEK...WITH CHANCES GENERALLY TAPERING DOWN LATER IN
THE WEEK AS DRIER AIR ONCE AGAIN FILTERS INTO THE REGION. WINDS WILL
REMAIN RATHER LIGHT WITH ONLY OCCASIONAL AFTERNOON GUSTS...HOWEVER
SUBSTANTIALLY STRONGER GUSTS WILL ACCOMPANY ANY AFTERNOON AND
EVENING THUNDERSTORMS. MINIMUM HUMIDITY LEVELS WILL GENERALLY ONLY
FALL INTO A 20 TO 30 PERCENT RANGE WITH GOOD TO EXCELLENT OVERNIGHT
RECOVERY....ALBEIT LOWER HUMIDITIES CAN BE EXPECTED LATE IN THE WEEK.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MCLANE/LEINS/KUHLMAN
AVIATION...MCLANE
FIRE WEATHER...LEINS
AREA FORECAST DISCUSSION
NWS ALBANY NY
353 AM EDT SUN JUL 13 2014
.SYNOPSIS...
WITH A WARM FRONT PASSING THROUGH THE REGION...A MOIST SOUTHERLY
FLOW WILL ALLOW FOR SOME SHOWERS AND THUNDERSTORMS TODAY...MAINLY
THIS AFTERNOON AND EVENING. ANY THUNDERSTORM WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY DOWNPOURS. WITH A SLOW MOVING COLD FRONT
APPROACHING FROM THE WEST...THE THREAT FOR SHOWERS AND THUNDERSTORMS
WILL CONTINUE INTO MONDAY AND TUESDAY. COOLER AND LESS HUMID AIR
WILL MOVE INTO THE REGION BEHIND THIS FRONTAL BOUNDARY FOR LATER IN
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 353 AM EDT...A DEEP 500 HPA LOW IS CURRENTLY DROPPING ACROSS
SOUTHERN CANADA TOWARDS THE NORTHERN PLAINS AND UPPER MIDWEST.
MEANWHILE...THE 500 HPA FLOW IS FAIRLY ZONAL OVER OUR AREA...WITH
RIDGING JUST DOWNSTREAM OVER THE WESTERN ATLANTIC.
AT THE SFC...A WARM FRONT IS CURRENTLY APPROACHING THE REGION FROM
THE GREAT LAKES...WHILE HIGH PRESSURE CONTINUES TO RETREAT OFF THE
NEW ENGLAND COAST. A SOUTHERLY FLOW IN PLACE HAS BEEN TRANSPORTING
MOIST AIR INTO THE REGION...WITH DEWPOINTS NOW MAINLY IN THE 60S.
ALTHOUGH THE DAY LOOKS TO START RAIN FREE...THERE WILL BE AN
INCREASING THREAT FOR SHOWERS AND THUNDERSTORMS AS WE GO THROUGH
THE DAY TODAY. THE COMBINATION OF A PASSING WEAK UPPER LEVEL
DISTURBANCE...THE NEARBY SFC BOUNDARY AND DAYTIME HEATING WILL
ALLOW FOR SHOWERS/TSTMS TO DEVELOP. THE LATEST 05Z 3KM HRRR SHOWS
A BROKEN LINE OF SHOWERS AND THUNDERSTORMS APPROACHING OUR AREA
FROM THE WEST DURING THE EARLY TO MID AFTN HOURS AND CONTINUING
INTO THE EVENING. OUR LOCAL HIRESWRF SHOWS A SIMILAR
SETUP...ALTHOUGH IT LOOKS A FEW HOURS SLOWER THAN THE HRRR.
THE MAIN THREAT WITH ANY THUNDERSTORM TODAY WILL BE VERY HEAVY
RAINFALL. PWAT VALUES SURGE TO NEARLY TWO INCHES BY LATE
TODAY...WHICH IS ABOUT 2 STD ABOVE NORMAL BASED OF CLIMO. WITH FZL
LEVELS EXPECTED TO BE AROUND 15 KFT AND CAPE LIMITED TO JUST
500-1000 J/KG...THE SETUP LOOKS FAVORABLE FOR WARM RAIN PROCESSES
TO DOMINATE AND LOCALLY HEAVY RAINFALL TO OCCUR. RAINFALL RATES
MAY EASILY EXCEED ONE INCH PER HOUR...AND MAY REACH 2.00-2.50
INCHES PER HOUR WITHIN THE HEAVIEST THUNDERSTORMS.
IT IS STILL UNCLEAR THE EXACT POTENTIAL FOR SEVERE STORMS TODAY.
EXTENSIVE HIGH LEVEL CLOUD COVER THIS MORNING WILL LIMIT SOLAR
INSOLATION...AND INSTABILITY LOOKS TO BE 1000 J/KG OR LESS. 0-6
KM BULK SHEAR OF AROUND 30 KTS THIS AFTN MAY BE ENOUGH TO ALLOW
FOR SOME ORGANIZATION OF STORMS...BUT THE LIMITED INSTABILITY MAY
HINDER THE DEVELOPMENT OF WIDESPREAD SEVERE STORMS. RIGHT NOW...WE
CANNOT RULE OUT ANY SEVERE STORMS...BUT IT APPEARS TO BE MORE
ISOLATED THAN A WIDESPREAD TYPE OF SEVERE WEATHER DAY. GUSTY
WINDS WOULD BE THE MAIN THREAT WITH ANY STORM...AS THE HIGH FZL
LEVELS AND POOR MID LEVEL LAPSE RATES /GENERALLY LESS THAN 6 C PER
KM/ WILL PREVENT MUCH LARGE HAIL FROM OCCURRING.
MAX TEMPS LOOK TO RANGE FROM THE MID 70S TO MID 80S...WITH THE
WARMEST TEMPS OVER THE MID HUDSON VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THERE WILL BE A CONTINUED THREAT FOR SHOWERS AND THUNDERSTORMS
THROUGH THE ENTIRE SHORT TERM PERIOD.
AS THE DEEP CUTOFF UPPER LEVEL LOW SLOWLY SPINS ACROSS THE MIDWEST
AND GREAT LAKES REGION...A SFC COLD FRONT WILL SLOWLY APPROACH OUR
AREA FROM THE WEST. WITH A CONTINUED MOIST SOUTHERLY FLOW AHEAD OF
THIS SYSTEM...THERE WILL BE SHOWERS AND THUNDERSTORMS AFFECTING
OUR REGION FOR THE NEXT FEW DAYS UNTIL THE COLD FRONT CAN CROSS
THROUGH OUR AREA. IT IS STILL UNCLEAR EXACTLY WHEN THIS COLD
FRONTAL PASSAGE WILL OCCUR...AS THE MODELS ARE STILL NOT IN TOTAL
AGREEMENT...BUT IT LOOKS TO BE SOMETIME BETWEEN LATE TUESDAY AND
EARLY WEDNESDAY MORNING.
BEFORE THEN...REPEATED ROUNDS OF SHOWERS AND THUNDERSTORMS CAN BE
EXPECTED. WITH PWATS REMAINING HIGH...THERE WILL BE A CONTINUED
THREAT FOR HEAVY RAINFALL WITH ANY THUNDERSTORM...AND POTENTIALLY
FLASH FLOODING. WITH EXPECTED CLOUD COVER...INSTABILITY WILL BE
LIMITED...SO THE SEVERE POTENTIAL LOOKS LOW.
DAYTIME HIGHS LOOK TO REACH THE 70S TO LOW 80S...AND OVERNIGHT
LOWS WILL MAINLY BE IN THE 60S.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE FINAL STAGE OF THE COLD FRONT WILL PASS TO OUR EAST WEDNESDAY
MORNING AS LARGE UPPER LOW AND DEEP CYCLONIC FLOW MIGRATES DOWN WELL
INTO THE CONUS. THIS WILL USHER IN RATHER COOL AND DRY CONDITIONS
FOR THE REMAINDER OF THE WEEK AS LARGE ELONGATED SURFACE HIGH MOVES
ACROSS THE REGION. H850 TEMPS WILL AVERAGE AROUND +10C RESULTING IN
COOLER THAN NORMAL HIGHS AND RATHER COOL NIGHTS WITH LOW HUMIDITY
VALUES. THE HEART OF THIS UPPER LOW MOVES ACROSS THURSDAY WHERE
SOME OF THE MOUNTAINOUS TERRAIN COULD SEE A SHOWER AS LAPSE RATES
STEEPEN DURING THE PEAK HEATING.
AS THE MAIN UPPER LOW BEGINS TO RETREAT NORTHWARD...A CYCLONIC
ENTITY IS LEFT BEHIND ACROSS THE TENNESSEE VALLEY PER THE 00Z GLOBAL
MODEL FORECASTS. SHORT WAVE ENERGY OUT OF THE INTERMOUNTAIN WEST
BECOMES EMBEDDED WITHIN THE DOWNSTREAM TROUGH/ENTITY AND AMPLIFIES
THE FLOW ACROSS THE SOUTHEAST CONUS. THIS IN TURN ATTEMPTS TO BRING
NORTHWARD MOISTURE IN THE FORM OF CLOUDS AND THE CHANCE FOR SHOWERS
LATER FRIDAY INTO SATURDAY. AT THIS TIME...WE WILL HOLD POPS INTO
THE SLIGHT CHANCE NORTH PORTIONS OF THE CWA TO CHANCE SOUTHERN
PORTIONS. THERE WILL BE SOME SLIGHT MODIFICATION TO THE THERMAL
PROFILES AS H850 TEMPS MODERATE TO ABOVE +10C.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
CANOPY OF SCT-BKN VFR CIGS WITH HIGH AND MID LEVEL CLOUD DECK ACROSS
THE REGION. THE EARLIER SHOWERS HAVE DISSIPATED BUT DID IMPACT
KGFL. HERE WITH NEAR CALM WINDS AND VERY NARROW DEWPOINT
DEPRESSIONS...IFR CONDITIONS HAVE ALREADY OCCURRED AND WILL CONTINUE
TO PLACE A TEMPO GROUP FOR ADDITIONAL IFR RESTRICTIONS EXPECTED.
THE REMAINDER OF THE TAF SITES...COMBINATION OF LARGER DEWPOINT
DEPRESSIONS OR AN ELEVATED SOUTHERLY WINDS SHOULD LIMIT THE
POTENTIAL FOR RESTRICTIONS.
HOWEVER...THE CHANCES FOR SHRA/TSRA WILL INCREASE BY SUNDAY
AFTERNOON...AND ESPECIALLY LATE IN THE DAY FOR ALL THE TERMINALS AS
THE FRONTAL BOUNDARY APPROACHES. WILL MENTION PROB30 GROUPS FOR TSRA
WITH MVFR CONDITIONS...ALTHOUGH IFR WILL BE POSSIBLE WITHIN ANY
CONVECTION.
SURFACE WINDS WILL BE SOUTHERLY LESS THAN 10 KT TONIGHT /SLIGHTLY
HIGHER IN KALB/...INCREASING TO 10-15 KT WITH SOME HIGHER GUSTS ON
SUNDAY.
OUTLOOK...
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
WEDNESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL BE LIMITED OVER THE NEXT FEW DAYS. A
SLOW MOVING FRONTAL SYSTEM WILL BRING SEVERAL OPPORTUNITIES FOR
SHOWERS AND LOCALLY HEAVY THUNDERSTORMS BETWEEN TODAY AND TUESDAY.
RH VALUES WILL GENERALLY REMAIN ABOVE 60 PERCENT THROUGH MONDAY
NIGHT.
&&
.HYDROLOGY...
A SLOW MOVING FRONTAL SYSTEM WILL BRING REPEATED ROUNDS OF SHOWERS
AND THUNDERSTORMS TO THE REGION BEGINNING TODAY AND LASTING
THROUGH TUESDAY NIGHT.
WITH PWAT VALUES NEAR TWO INCHES...THERE WILL BE A RISK FOR LOCALLY HEAVY
RAINFALL WITHIN ANY THUNDERSTORM. AT THE VERY LEAST...RAINFALL
RATES WILL BE HIGH ENOUGH TO CAUSE FLOODING OF SMALL STREAMS...POOR
DRAINAGE...LOW LYING AND URBAN AREAS. IF THUNDERSTORMS TRACK OVER
THE SAME LOCATION WITHIN A SHORT PERIOD OF TIME...FLASH FLOODING
WILL BE POSSIBLE...ESPECIALLY WITHIN ANY URBAN LOCATIONS.
ONCE THE COLD FRONT PASSES THROUGH THE AREA SOMETIME LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING...THE THREAT FOR HEAVY RAIN WILL END
AND COOLER AND LESS HUMID AIR WILL WORK INTO OUR REGION FOR THE
REMAINDER OF THE WEEK. THIS WILL ALLOW FOR ANY HIGH WATER TO
RECEDE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR
WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS
SHORT TERM...FRUGIS
LONG TERM...BGM
AVIATION...BGM
FIRE WEATHER...FRUGIS
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1251 AM CDT SUN JUL 13 2014
.MESOSCALE DISCUSSION..1204 AM CDT
AREA OF RAIN WITH EMBEDDED CONVECTION...PARTIALLY FROM DECAYED
MCS...CONTINUES TO SHIFT EAST DRIVEN BY STRONGER MID-LEVEL WINDS
AND ELONGATED SHORT WAVE. RAINFALL RATES OF ONE HALF TO
SPORADICALLY ONE INCH PER HOUR ARE BEING OBSERVED BASED ON
OBSERVATIONS AND RADAR ESTIMATED TOTALS. RAINFALL SHOULD LAST
AROUND 2-3 HOURS IN THE CHICAGO METRO AREA AND ADJACENT LOCATIONS.
HAVE COORDINATED WITH THE NORTH CENTRAL RIVER FORECAST CENTER ON
THEIR FLASH FLOOD GUIDANCE FOR THE SOUTHERN CHICAGO METRO AREA.
GIVEN CONFIDENCE IS HIGH FROM THEM IN LOW VALUES OF ONLY 1.25 TO
2.00 INCHES IN THREE HOURS FOR FLOODING...DUE TO THE HEAVY
RAINFALL OBSERVED EARLY SATURDAY MORNING...HAVE GONE AHEAD AND
ISSUED A FLASH FLOOD WARNING FOR THE CENTRAL TO SOUTHERN CHICAGO
METRO AREA.
PROPAGATION IS EXPECTED TO CONTINUE EAST-SOUTHEAST...THOUGH SOME
SLOWING IS EXPECTED FOR AREAS ALONG AND SOUTH OF THE KANKAKEE
RIVER AS THE 30-40 KT LOW-LEVEL JET OFFSETS SOUTHWARD MOVEMENT.
THIS COULD CREATE TRAINING AND FLOODING PROBLEMS...AGAIN
PARTICULARLY FOR THE AREAS HIT HARD ON SATURDAY MORNING /SUCH AS
WESTERN FORD AND SOUTHERN LIVINGSTON COUNTIES/.
MTF
&&
.DISCUSSION...
311 PM CDT
THIS AFTERNOON...
THE SURFACE LOW IS OVER NORTHERN MANITOBA AND THE UPPER LEVEL LOW IS
STACKED JUST ABOVE IT. STILL HAVE MOSTLY CLOUD SKIES WITH A FEW
BREAKS OF SUN AND WE ARE SLOWLY RECOVERING FROM THIS MORNING/S
CONVECTION. THE 18Z DVN SOUNDING FEATURED 1.7 INCHES OF PWAT AND
AROUND 1500 J/KG OF CAPE. THE SOUNDING ALSO HAD A STOUT CAP AT 850MB
WHICH MATCHES WELL WITH THE LATEST AMDAR SOUNDINGS. LAPSE RATES TO
950 MB WERE SURPRISINGLY STEEP GIVEN THE THICK CLOUD COVER. WITH THE
CAP IN PLACE AND SLOW RECOVERY NOT EXPECTING MUCH CONVECTIVE
ACTIVITY AHEAD OF THE MAIN LINE OF STORMS. IN GENERAL EXPECTING
CLOUDS TO CONTINUE THIN AND TEMPS RISE INTO THE MID 80S BY LATE THIS
AFTN. IT WILL CONTINUE TO BE MUGGY AS PWAT VALUES INCREASE TO
AROUND 2 INCHES.
THIS EVENING AND TONIGHT...
AN UPPER LEVEL SHORTWAVE CURRENTLY OVER IOWA WILL MOVE OVER THE CWA
THIS EVENING ADDING FORCING FOR STORMS. A SURFACE LOW IS OVER
NORTHERN MANITOBA AND ITS COLD FRONT STRETCHES FROM NORTHWEST
WISCONSIN THROUGH CENTRAL IOWA. A LINE OF STORMS WILL FORM ALONG
THE FRONT AND SLOWLY PUSH SOUTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. 850MB STEERING FLOW WILL BE WEST AT 30-40 KT AHEAD OF THE
LINE BUT ONLY AROUND 15 KT FROM THE NORTH BEHIND THE FRONT. TIMING
DIFFERS BETWEEN THE MODELS BUT THINKING A BLEND OF OUR LOCAL ARW AND
THE RAP LOOK REASONABLE. THE NAM LOOKS TOO FAST WHILE THE HRRR LOOKS
TOO SLOW.
THE LINE MAY PRODUCE SEVERE WIND GUSTS IN EXCESS OF 60 MPH...BUT THE
MAIN CONCERN WILL BE FLASH FLOODING. PWAT VALUES REMAIN HIGH AT
1.7-1.8 INCHES AND VALUES WILL INCREASE TO AROUND 2 INCHES BY THIS
EVENING. HAVE ISSUED A FLASH FLOOD WATCH FOR THE ENTIRE WARNING
AREA FOR THIS EVENING THROUGH TOMORROW MORNING. TOTAL RAINFALL FROM
THIS STORM WILL BE IN EXCESS OF 1 INCH. THE HIGHEST TOTALS WILL
LIKELY BE ALONG THE IL/WI STATE LINE WHERE RAINFALL TOTALS WILL
EASILY APPROACH 2 INCHES. IN ADDITION...SOME AREAS THIS MORNING
FROM COOK COUNTY SOUTH THROUGH PONTIAC AND GIBSON CITY SAW MULTIPLE
INCHES OF RAIN OVERNIGHT INTO THIS MORNING. THESE AREAS WILL BE THE
MOST SUSCEPTIBLE TO FLASH FLOODING AS WATER LEVELS ARE ALREADY
HIGH.
TEMPERATURES WILL QUICKLY FALL BEHIND THE LINE OF STORMS AND LOWS
WILL BE IN THE UPPER 60S TO LOWER 70S.
SUNDAY AND MONDAY...
THE UPPER LEVEL LOW SPLITS SUNDAY NIGHT AND THE FIRST TROUGH AXIS
MOVES THROUGH MONDAY NIGHT. AT THE SURFACE A SECOND COLD FRONT
MOVES THROUGH SUNDAY AND THEN STALLS OUT JUST SOUTH OF THE CWA
MONDAY MORNING. THE HIGHEST INSTABILITY VALUES WILL BE SOUTH OF I-80
SO ONLY HAVE A CHANCE OF STORMS SOUTH OF I-80. NOT EXPECTING MUCH IN
THE WAY OF PRECIP AT THIS TIME.
A BAND OF SHOWERS AND STORMS MAY FORM SUNDAY NIGHT FIRST ALONG THE
IL/WI STATE LINE AND THEN SPREAD SOUTH AS A VORTICITY STREAMER FROM
THE UPPER LEVEL LOW PUSHES SOUTH THROUGH THE REGION. THE SHOWERS
MAY PERSIST INTO LATE SUNDAY NIGHT AND BY THEN ONLY EXPECTING
SHOWERS. CONFIDENCE IS MEDIUM WITH THE STORMS DEVELOPING AND
COVERAGE.
YET ANOTHER COLD FRONT COMES THROUGH MONDAY AND HAVE A CHANCE OF
SHOWERS AND STORMS MONDAY AFTERNOON AND EVENING. THE BIGGER STORY
WILL BE THE COOL AIR THAT FOLLOWS THE COLD FRONT. HIGHS ON SUNDAY
WILL BE IN THE LOWER 80S WHILE MONDAY/S HIGHS WILL BE IN THE MID TO
UPPER 70S. MONDAY NIGHT LOOKS CRISP WITH LOWS IN THE LOWER 50S.
EXTENDED...TUESDAY THROUGH FRIDAY...
THE UPPER LEVEL TROUGH SLOWLY LIFTS NE THROUGH THURSDAY WHILE A
SURFACE HIGH BUILDS OVER THE REGION TUESDAY NIGHT. THE EXTENDED
LOOKS DRY WITH BELOW NORMAL TEMPERATURES.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHRA/TSRA THROUGH 0730Z WITH OCCASIONAL MVFR OR IFR
VISIBILITIES.
* IFR/LIFR CIGS TONIGHT AFTER SHRA/TSRA ENDS...LINGERING INTO THE
MORNING
* SMALL CHANCE FOR SHRA/TSRA LATE SUNDAY AFTERNOON/EARLY SUNDAY
EVE.
KMD
//DISCUSSION...UPDATED 06Z...
SHOWERS AND EMBEDDED THUNDERSTORMS WILL CLEAR THE CHICAGO TERMINALS
IN THE COMING HOURS. THERE IS SOME CONCERN THAT ADDITIONAL DEVELOPMENT
WILL OCCUR... BUT IT LOOKS TO LARGELY REMAIN SOUTH OF THE MAIN
CHICAGO AREA TERMINALS. THERE IS QUITE A BIT OF IFR CIGS AND
VISIBILITIES IN SOUTHERN WISCONSIN AT THE MOMENT...AND THIS HAS
BUILT SOUTH INTO NORTH CENTRAL ILLINOIS. CONCERNED THAT THESE WILL BUILD
ACROSS NE ILLINOIS BEHIND THE THE MAIN PRECIPITATION SHIELD AS
DEWPOINTS REMAIN ELEVATED AND FLOW IS RATHER WEAK. THESE ARE
EXPECTED TO LIFT LATER THIS MORNING.
WINDS SHOULD GENERALLY CONTINUE TO TURN TO THE W AND NW BEHIND THE
INITIAL COOL FRONT THAT IS MOVING THROUGH NOW. A SECONDARY STRONGER
FRONT WILL MOVE THROUGH LATE IN THE DAY SUNDAY. THIS COULD TRIGGER A
FEW SHOWERS OR STORMS...THOUGH THERE IS LIMITED FORCING SO KEPT THE TAFS
DRY.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MODERATE TO HIGH IN TSRA END TIMING. LOW IN ANY REDEVELOPMENT
THAT IF OCCURS SHOULD LARGELY REMAIN SOUTH OF ORD AND MDW.
* MODERATE THAT MVFR/IFR CIGS WILL RETURN AFTER STORMS DEPART...WITH
POSSIBLE LIFR CIGS. LOW IN PRECISE DEPARTURE TIME LATER THIS
MORNING.
* LOW IN ANY SHRA/TSRA SUNDAY AFTERNOON/EARLY SUNDAY EVE.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF AFTERNOON TSRA.
TUESDAY...CHANCE OF SHRA.
WEDNESDAY-FRIDAY...VFR LIKELY.
MTF
&&
.MARINE...
423 PM CDT
SOUTHERLY FLOW PERSISTING OVER THE ENTIRE LAKE THIS AFTERNOON AS
HIGH PRESSURE REMAINS SITUATED OVER THE ATLANTIC COAST...AND AS A
TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE JUST
WEST OF THE LAKE. AS THESE SOUTHERLY WINDS BECOME MORE SOUTHWEST
AND THEN EVENTUALLY WEST TONIGHT WITH THE PASSAGE OF THIS
TROUGH...DO EXPECT SPEEDS TO REMAIN IN THE 10 TO 20 KT RANGE.
EXPECTED COMPLEX OF SHOWERS AND THUNDERSTORMS WILL LIKELY PROVIDE
ERRATIC WINDS LATER THIS EVENING AND OVERNIGHT...AS WELL AS THE
POSSIBILITY FOR SLIGHTLY HIGHER SPEEDS. DO EXPECT MORE OF A WEST
NORTHWEST WIND ACROSS THE LAKE ON SUNDAY...AS A SECONDARY
TROUGH/FRONT MOVE SOUTHEAST THROUGH THE GREAT LAKES REGION.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 PM SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
PM SUNDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1205 AM CDT SUN JUL 13 2014
.MESOSCALE DISCUSSION...
1204 AM CDT
AREA OF RAIN WITH EMBEDDED CONVECTION...PARTIALLY FROM DECAYED
MCS...CONTINUES TO SHIFT EAST DRIVEN BY STRONGER MID-LEVEL WINDS
AND ELONGATED SHORT WAVE. RAINFALL RATES OF ONE HALF TO
SPORADICALLY ONE INCH PER HOUR ARE BEING OBSERVED BASED ON
OBSERVATIONS AND RADAR ESTIMATED TOTALS. RAINFALL SHOULD LAST
AROUND 2-3 HOURS IN THE CHICAGO METRO AREA AND ADJACENT LOCATIONS.
HAVE COORDINATED WITH THE NORTH CENTRAL RIVER FORECAST CENTER ON
THEIR FLASH FLOOD GUIDANCE FOR THE SOUTHERN CHICAGO METRO AREA.
GIVEN CONFIDENCE IS HIGH FROM THEM IN LOW VALUES OF ONLY 1.25 TO
2.00 INCHES IN THREE HOURS FOR FLOODING...DUE TO THE HEAVY
RAINFALL OBSERVED EARLY SATURDAY MORNING...HAVE GONE AHEAD AND
ISSUED A FLASH FLOOD WARNING FOR THE CENTRAL TO SOUTHERN CHICAGO
METRO AREA.
PROPAGATION IS EXPECTED TO CONTINUE EAST-SOUTHEAST...THOUGH SOME
SLOWING IS EXPECTED FOR AREAS ALONG AND SOUTH OF THE KANKAKEE
RIVER AS THE 30-40 KT LOW-LEVEL JET OFFSETS SOUTHWARD MOVEMENT.
THIS COULD CREATE TRAINING AND FLOODING PROBLEMS...AGAIN
PARTICULARLY FOR THE AREAS HIT HARD ON SATURDAY MORNING /SUCH AS
WESTERN FORD AND SOUTHERN LIVINGSTON COUNTIES/.
MTF
&&
.DISCUSSION...
311 PM CDT
THIS AFTERNOON...
THE SURFACE LOW IS OVER NORTHERN MANITOBA AND THE UPPER LEVEL LOW IS
STACKED JUST ABOVE IT. STILL HAVE MOSTLY CLOUD SKIES WITH A FEW
BREAKS OF SUN AND WE ARE SLOWLY RECOVERING FROM THIS MORNING/S
CONVECTION. THE 18Z DVN SOUNDING FEATURED 1.7 INCHES OF PWAT AND
AROUND 1500 J/KG OF CAPE. THE SOUNDING ALSO HAD A STOUT CAP AT 850MB
WHICH MATCHES WELL WITH THE LATEST AMDAR SOUNDINGS. LAPSE RATES TO
950 MB WERE SURPRISINGLY STEEP GIVEN THE THICK CLOUD COVER. WITH THE
CAP IN PLACE AND SLOW RECOVERY NOT EXPECTING MUCH CONVECTIVE
ACTIVITY AHEAD OF THE MAIN LINE OF STORMS. IN GENERAL EXPECTING
CLOUDS TO CONTINUE THIN AND TEMPS RISE INTO THE MID 80S BY LATE THIS
AFTN. IT WILL CONTINUE TO BE MUGGY AS PWAT VALUES INCREASE TO
AROUND 2 INCHES.
THIS EVENING AND TONIGHT...
AN UPPER LEVEL SHORTWAVE CURRENTLY OVER IOWA WILL MOVE OVER THE CWA
THIS EVENING ADDING FORCING FOR STORMS. A SURFACE LOW IS OVER
NORTHERN MANITOBA AND ITS COLD FRONT STRETCHES FROM NORTHWEST
WISCONSIN THROUGH CENTRAL IOWA. A LINE OF STORMS WILL FORM ALONG
THE FRONT AND SLOWLY PUSH SOUTH THROUGH THE CWA THIS EVENING AND
OVERNIGHT. 850MB STEERING FLOW WILL BE WEST AT 30-40 KT AHEAD OF THE
LINE BUT ONLY AROUND 15 KT FROM THE NORTH BEHIND THE FRONT. TIMING
DIFFERS BETWEEN THE MODELS BUT THINKING A BLEND OF OUR LOCAL ARW AND
THE RAP LOOK REASONABLE. THE NAM LOOKS TOO FAST WHILE THE HRRR LOOKS
TOO SLOW.
THE LINE MAY PRODUCE SEVERE WIND GUSTS IN EXCESS OF 60 MPH...BUT THE
MAIN CONCERN WILL BE FLASH FLOODING. PWAT VALUES REMAIN HIGH AT
1.7-1.8 INCHES AND VALUES WILL INCREASE TO AROUND 2 INCHES BY THIS
EVENING. HAVE ISSUED A FLASH FLOOD WATCH FOR THE ENTIRE WARNING
AREA FOR THIS EVENING THROUGH TOMORROW MORNING. TOTAL RAINFALL FROM
THIS STORM WILL BE IN EXCESS OF 1 INCH. THE HIGHEST TOTALS WILL
LIKELY BE ALONG THE IL/WI STATE LINE WHERE RAINFALL TOTALS WILL
EASILY APPROACH 2 INCHES. IN ADDITION...SOME AREAS THIS MORNING
FROM COOK COUNTY SOUTH THROUGH PONTIAC AND GIBSON CITY SAW MULTIPLE
INCHES OF RAIN OVERNIGHT INTO THIS MORNING. THESE AREAS WILL BE THE
MOST SUSCEPTIBLE TO FLASH FLOODING AS WATER LEVELS ARE ALREADY
HIGH.
TEMPERATURES WILL QUICKLY FALL BEHIND THE LINE OF STORMS AND LOWS
WILL BE IN THE UPPER 60S TO LOWER 70S.
SUNDAY AND MONDAY...
THE UPPER LEVEL LOW SPLITS SUNDAY NIGHT AND THE FIRST TROUGH AXIS
MOVES THROUGH MONDAY NIGHT. AT THE SURFACE A SECOND COLD FRONT
MOVES THROUGH SUNDAY AND THEN STALLS OUT JUST SOUTH OF THE CWA
MONDAY MORNING. THE HIGHEST INSTABILITY VALUES WILL BE SOUTH OF I-80
SO ONLY HAVE A CHANCE OF STORMS SOUTH OF I-80. NOT EXPECTING MUCH IN
THE WAY OF PRECIP AT THIS TIME.
A BAND OF SHOWERS AND STORMS MAY FORM SUNDAY NIGHT FIRST ALONG THE
IL/WI STATE LINE AND THEN SPREAD SOUTH AS A VORTICITY STREAMER FROM
THE UPPER LEVEL LOW PUSHES SOUTH THROUGH THE REGION. THE SHOWERS
MAY PERSIST INTO LATE SUNDAY NIGHT AND BY THEN ONLY EXPECTING
SHOWERS. CONFIDENCE IS MEDIUM WITH THE STORMS DEVELOPING AND
COVERAGE.
YET ANOTHER COLD FRONT COMES THROUGH MONDAY AND HAVE A CHANCE OF
SHOWERS AND STORMS MONDAY AFTERNOON AND EVENING. THE BIGGER STORY
WILL BE THE COOL AIR THAT FOLLOWS THE COLD FRONT. HIGHS ON SUNDAY
WILL BE IN THE LOWER 80S WHILE MONDAY/S HIGHS WILL BE IN THE MID TO
UPPER 70S. MONDAY NIGHT LOOKS CRISP WITH LOWS IN THE LOWER 50S.
EXTENDED...TUESDAY THROUGH FRIDAY...
THE UPPER LEVEL TROUGH SLOWLY LIFTS NE THROUGH THURSDAY WHILE A
SURFACE HIGH BUILDS OVER THE REGION TUESDAY NIGHT. THE EXTENDED
LOOKS DRY WITH BELOW NORMAL TEMPERATURES.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 03Z...
* TSRA 0400Z-0700Z WITH IFR VISIBIILTY IN HEAVY RAIN AND GUSTY
WINDS AT THE LEADING EDGE.
* MVFR CIGS THROUGHOUT THE NIGHT WITH TEMPORARY IFR LIKELY DURING
THE TSRA.
* SMALL CHANCE FOR SHRA/TSRA LATE SUNDAY AFTERNOON/EARLY SUNDAY
EVE.
//DISCUSSION...UPDATED 03Z...
PREV DISCUSSION...UPDATED 00Z...
A SURFACE WARM FRONT IS DRAPED ACROSS NORTHERN IL...PRETTY NEAR THE
CHICAGO AREA TERMINALS. THIS WILL SERVE AS A FOCUS FOR STORMS AS
THE EVENING PROGRESSES...WITH STORMS LIKELY TO EXPAND EASTWARD
THROUGH MID-EVENING AS AN UPPER DISTURBANCE MOVES OVER THE AREA.
IT STILL REMAINS TRICKY TO TIME THE FIRST STORMS...BUT THE
GREATEST COVERAGE LOOKS TO BE THE TIMES WITH PREVAILING TSRA IN
THE TAFS. DUE TO A SUBSTANTIAL AMOUNT OF MOISTURE...HIGH RAINFALL
RATES AND LOW VISIBILITY...POTENTIALLY TO LIFR...IS TEMPORARILY
EXPECTED.
PATCHY MVFR CIGS HAVE BEEN SEEN ALONG AND NORTH OF THE WARM FRONT
AND THAT SHOULD CONTINUE UNTIL THE STORM ARRIVAL TIME. IN THE WAKE
OF THE STORMS...LINGERING MVFR CIGS MAY PERSIST FOR UP TO SEVERAL
HOURS.
WINDS ARE SOUTH-SOUTHWEST AT MUCH OF THE TAF SITES EARLY THIS
EVE AND THAT SHOULD CONTINUE. AS STORMS MOVE OVER...OF COURSE SOME
VARIABILITY CAN BE EXPECTED. A LARGE WELL-DEFINED COMPLEX OF
STORMS IS NOT EXPECTED...WHICH CAN SOMETIMES RESULT IN A SOUTHEAST
WIND AFTERWARD.
THE INITIAL COOL FRONT WILL MOVE THROUGH OVERNIGHT TURNING WINDS
TO THE NORTHWEST. A SECONDARY STRONGER ONE WILL MOVE THROUGH LATE
IN THE DAY SUNDAY. THIS COULD TRIGGER A FEW SHOWERS OR
STORMS...THOUGH THERE IS LIMITED FORCING.
//ORD AND MDW CONFIDENCE...UPDATED 03Z...
* HIGH IN TSRA TIMING. HIGH IN AT LEAST TEMPORARY IFR VISIBILITY
DURING THE TSRA.
* HIGH THAT MVFR CIGS WILL CONTINUE AFTER THE STORMS FOR AT LEAST
A COUPLE HOURS...WITH POSSIBLE IFR CIGS. LOW IN PRECISE
DEPARTURE TIME.
* LOW IN ANY SHRA/TSRA SUNDAY AFTERNOON/EARLY SUNDAY EVE.
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF AFTERNOON TSRA.
TUESDAY...CHANCE OF SHRA.
WEDNESDAY-FRIDAY...VFR LIKELY.
MTF
&&
.MARINE...
423 PM CDT
SOUTHERLY FLOW PERSISTING OVER THE ENTIRE LAKE THIS AFTERNOON AS
HIGH PRESSURE REMAINS SITUATED OVER THE ATLANTIC COAST...AND AS A
TROUGH OF LOW PRESSURE AND ASSOCIATED FRONTAL BOUNDARY ARE JUST
WEST OF THE LAKE. AS THESE SOUTHERLY WINDS BECOME MORE SOUTHWEST
AND THEN EVENTUALLY WEST TONIGHT WITH THE PASSAGE OF THIS
TROUGH...DO EXPECT SPEEDS TO REMAIN IN THE 10 TO 20 KT RANGE.
EXPECTED COMPLEX OF SHOWERS AND THUNDERSTORMS WILL LIKELY PROVIDE
ERRATIC WINDS LATER THIS EVENING AND OVERNIGHT...AS WELL AS THE
POSSIBILITY FOR SLIGHTLY HIGHER SPEEDS. DO EXPECT MORE OF A WEST
NORTHWEST WIND ACROSS THE LAKE ON SUNDAY...AS A SECONDARY
TROUGH/FRONT MOVE SOUTHEAST THROUGH THE GREAT LAKES REGION.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...FLASH FLOOD WATCH...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL 1 PM SUNDAY.
IN...FLASH FLOOD WATCH...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 1
PM SUNDAY.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
244 AM MDT SUN JUL 13 2014
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN JUL 13 2014
UPPER FLOW WILL BE NORTHWEST FROM TODAY THROUGH TUESDAY NIGHT. A
SURFACE FRONT WILL MOVE SOUTH INTO NORTHWEST KANSAS LATE THIS
AFTERNOON/EARLY THIS EVENING. HIGH PRESSURE WILL MOVE INTO THE
PLAINS SUNDAY NIGHT AND MONDAY AND PERSIST THROUGH TUESDAY NIGHT.
EARLY THIS MORNING LIGHT SHOWERS CONTINUE OVER THE SOUTHWEST CORNER
OF THE FA. THE HRRR INDICATES THAT THESE SHOWERS SHOULD DISSIPATE
BY 14 OR 15Z. PLAN TO INCLUDE SCATTERED SHOWERS IN THE GRIDS AND
ZONES FOR THESE.
FOR TODAY AND TONIGHT A WEAK FRONT APPROACHES THE NORTHERN FA BY
LATE AFTERNOON. THERE IS A WEAK SHORTWAVE IN THE FLOW AS WELL WHICH
SHOULD SUPPORT LOW CHANCES OF STORMS. CHANCE POPS WILL FOLLOW THE
FRONT SOUTH ACROSS THE FA TONIGHT.
THE GFS AND NAM HAVE DIFFERENCES WITH THE AMOUNT OF FORCING FOR
MONDAY/MONDAY NIGHT. THE NAM DOES NOT INDICATE ANY FORCING UNTIL
AFTER 06Z TUESDAY. THE GFS SHOWS VERY WEAK FORCING FOR MONDAY WITH
A LACK OF FORCING MONDAY NIGHT. AS A RESULT, CONFIDENCE IS LOW SO
WILL KEEP POPS LOW. THE BEST CHANCE OF THUNDERSTORMS WILL BE OVER
EASTERN COLORADO.
TUESDAY/TUESDAY NIGHT GOOD MOISTURE AND FORCING COME TOGETHER OVER
THE FA. INSTABILITY DROPS OFF FOR THIS EVENT SO SHOWERS WITH
ISOLATED THUNDER WILL BE THE PREDOMINANT TYPE OF WEATHER OTHER THAN
TUESDAY AFTERNOON/EVENING IN THE WEST WHERE THERE WILL BE GREATER
INSTABILITY.
MAX TEMPERATURES TODAY AND MONDAY WILL RISE TO THE MID AND UPPER
80S. MUCH COOLER READINGS WILL OCCUR ON TUESDAY WITH MAX
TEMPERATURES AROUND 70. MIN TEMPERATURES WILL COOL TO THE LOWER TO
MID 60S TONIGHT. MIN TEMPERATURES MONDAY AND TUESDAY NIGHTS WILL BE
IN THE MID AND UPPER 50S.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 220 AM MDT SUN JUL 13 2014
WEDNESDAY...AN UPPER LEVEL SHORTWAVE TROUGH WILL SHIFT ACROSS THE
HIGH PLAINS REGION WEDNESDAY...WHICH LOOKS TO BE THE LAST BIT OF
ENERGY ASSOCIATED WITH THE MAIN UPPER LEVEL LOW CENTER OVER THE
EASTERN THIRD OF THE CONUS. THE POSITION OF THE SURFACE HIGH
PRESSURE SYSTEM ON WEDNESDAY WILL FUNNEL LOTS OF MOISTURE INTO THE
AREA...WITH ALL GUIDANCE SUGGESTING AT LEAST SOME CHANCES FOR
PRECIPITATION ACROSS MUCH OF THE AREA. INSTABILITY ALOFT SHOULD
REMAIN OVER EASTERN COLORADO...BUT CANNOT RULE OUT SOME ISOLATED
THUNDERSHOWERS OVER THE REST OF THE AREA WEDNESDAY. DUE TO CLOUD
COVER...RAINFALL AND ALREADY COOLER CANADIAN AIR...HIGH TEMPERATURES
WILL BE 15 TO 20 DEGREES BELOW NORMAL IN THE UPPER 60S TO LOWER
70S...WITH SOME GUIDANCE SUGGESTING TEMPERATURES COULD BE EVEN A BIT
LOWER.
THURSDAY/FRIDAY...A SHORTWAVE RIDGE WILL BEGIN MOVING OVER THE
FORECAST AREA FOR THURSDAY AND FRIDAY. SOME LINGERING CHANCES FOR
THUNDERSHOWERS WILL REMAIN FOR THE REGION ON THURSDAY AS THE SURFACE
CONVERGENCE ZONE SHIFTS SOUTHWARD WITH THE EXITING HIGH PRESSURE
SYSTEM TO THE EAST. WINDS WILL SHIFT AND BRING IN MORE DRY AIR ALOFT
ON FRIDAY...WHICH SHOULD KEEP CONDITIONS DRY FOR MOST OF THE AREA.
CHANCES FOR AFTERNOON THUNDERSTORMS IN EASTERN COLORADO ARE POSSIBLE
ALONG SURFACE TROUGH AND COULD BE SUSTAINABLE WITH PLENTY OF
INSTABILITY. TEMPERATURES WILL BEGIN TO REBOUND THURSDAY IN THE
UPPER 70S TO LOWER 80S...AND THE RETURN OF WARM AIR ADVECTION WILL
BRING TEMPERATURES BACK TO NEAR NORMAL ON FRIDAY.
SATURDAY...THE NEXT UPPER LEVEL TROUGH LOOKS TO BEGIN TO MOVE INTO
THE PACIFIC NORTHWEST ON SATURDAY...WHICH COULD BE THE NEXT WEATHER
MAKER FOR THE REGION NEXT WEEKEND. CHANCES FOR AFTERNOON STORMS WILL
CONTINUE ON SATURDAY AS THE POSSIBILITY OF THE NEXT COLD FRONTAL
PASSAGE WILL AFFECT THE AREA. MODEL TIMING VARIES ON THE PASSAGE TO
EITHER SATURDAY OR SUNDAY...SO CONFIDENCE IS LOW REGARDING PINNING
DOWN PRECIPITATION CHANCES AT THIS TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1117 PM MDT SAT JUL 12 2014
VFR CONDITIONS EXPECTED THROUGH THE PERIOD AT THIS TIME. MAIN
CONVECTION CONTINUES TO BE SOUTH AND WEST OF KGLD. NEWER GUIDANCE
HAS THIS AREA FURTHER SOUTHWEST THAN EARLIER GUIDANCE.
THUNDERSTORM CHANCES LOOK TO BE A LITTLE FURTHER NORTH TOMORROW. A
WEAK SURFACE BOUNDARY AND SHORTWAVE TROUGH WILL CREATE A CHANCE
FOR THUNDERSTORMS AT BOTH SITES...MAINLY AT KGLD. FEEL THE BETTER
CHANCE IS AT KGLD RIGHT NOW SO PUT IN A VCTS MENTION THERE
BEGINNING AT 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...MK
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1151 PM CDT Sat Jul 12 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Sunday)
Issued at 336 PM CDT SAT JUL 12 2014
19Z water vapor imagery shows a broad mid level ridge centered over
northern OK/southern KS while a deep closed low spun over Manitoba
and was beginning to move south. One trough axis appears to have
rotated through NEB with a second shortwave trough digging southeast
through ND. At the surface a cold front stretched from northwest KS
into central IA, and has been slowly moving southeast this afternoon.
For tonight and Sunday, the models continue to show the cold front
moving through the forecast area late tonight. This seems to make
since with the initial mid level trough rotating through IA tonight
and the ridge overhead breaking down. Most of the model guidance
shows a well defined band of frontogenesis within the mid levels of
the atmosphere along with a narrow axis of moisture. This appears to
be the main driver of precip tonight and Sunday as forecast
soundings continue to show limited moisture in the lower atmosphere.
So think there is a good chance for elevated showers and storms to
develop this evening and overnight rather than deep moist convection
from surface parcels. Not sure if the HRRR is handling the
frontogenesis as well as it depicts convection and is the reason it
has been one of the drier solutions. Would not be surprised to see
precip lingering through the morning much like it has over
northeastern NEB and northern IA today. Since I`m expecting precip
to be elevated, chances for severe weather appear to be very limited
due to modest elevated instability from 700-500MB lapse rates only
around 6 C/km.
There does not appear to be a big surge in cold dry air behind the
front tonight. Obs upstream show decent moisture pooling behind the
boundary. With mostly cloudy skies anticipated behind the front and
dewpoints remaining in the mid and upper 60s behind the front, think
lows will once again be mild. Areas along the NEB state line should
see lows in the upper 60s while elsewhere is expected to remain in
the lower 70s. Think highs Sunday will depend on how much insolation
reaches the ground. With skies likely to remain partly to mostly
cloudy across east central KS from the elevated showers, have highs
in the mid 80s across Anderson and Coffey counties. Elsewhere think there
could be enough sunshine for highs to reach the upper 80s to around
90. Considered maybe bumping highs up a degree or two from what I
have now since there isn`t a lot of cold air advection behind the
front, but held off since models show some cooling at 850 and the
thermal ridge setting up further south.
.LONG TERM...(Sunday Night through Saturday)
Issued at 336 PM CDT SAT JUL 12 2014
Will linger a low pop across the far southeast counties of the cwa for
Sunday evening...otherwise will leave the remainder of the forecast dry
overnight except for the far northwest corner with the approach of the
next shortwave trough. As this wave and stronger cold front moves
through...mid level frontogenesis will increase from north to south
through midday with decreasing lift in the mid to late afternoon
across the southern cwa. Will therefore go dry all areas of the
county warning area. Rainfall amounts will generally average a tenth
to a third of an inch during the day.
Much cooler and drier air works southward across the cwa through the
night with 850 temps by sunrise Tuesday falling into the 7 to 10 deg
C range with diminishing winds and mostly clear skies. This will
probably be the coolest morning of the week with lows in the low to
middle 50s all areas which will be near or just above record lows
for July 15th.
By late Tuesday night models try to bring the remnants of an MCS
east and southeast across central Ks which may clip the far
southwest corner of the cwa by sunrise...then the southern half of
the cwa during the day. Have inserted low pops across this
area...and inched low temps up due to more cloudcover...but still
unseasonably cool in the middle to upper 50s and highs in the 70s.
As another northwest flow shortwave moves from the central high
plains into the southern plains...most of the precip through the end
of the week should remain south of the cwa with weak upper ridging
building back into the area by the weekend. Will keep the remainder
of the fcst beyond Wednesday dry with a gradual warming trend. Highs
will warm through the 80s as low temps moderate through the 60s to
around 70 by Saturday night.
&&
.AVIATION...(For the 06Z TAFs through 06Z Sunday Night)
Issued at 1140 PM CDT SAT JUL 12 2014
Isolated TSRA developing along the cold front seen on radar just
south of KMHK. Will mention a VCTS as coverage is low. Main line
of TSRA over southern Nebraska will slowly track southward and
weaken as it reaches terminals. Initial wind shift will arrive
between 06Z- 09Z before scattered showers with embedded thunder
are possible through 13Z. Timing and intensity of the weakening
convection from guidance left low confidence in prevailing TSRA
mention. On the low end chance it occurs, MVFR to IFR cigs are
possible. SCT MVFR cigs appears a better possibility as low level
moisture increases behind the exiting showers. Should expect lower
cigs to quickly dissipate by mid morning with clearing skies and
northerly winds near or just below 10 kts during the afternoon.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Wolters
LONG TERM...63
AVIATION...Bowen
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
207 AM EDT SUN JUL 13 2014
.UPDATE...
ISSUED AT 155 AM EDT SUN JUL 13 2014
A RATHER SUBSTANTIAL AMOUNT OF MID AND HIGH LEVEL CLOUDS ARE
SPREADING EAST SOUTHEAST INTO AND ACROSS EASTERN KY AS A MID LEVEL
WAVE IS PASSING THROUGH THE OH VALLEY. MEANWHILE...VALLEY
LOCATIONS...ESPECIALLY IN THE EAST WERE RUNNING WARMER THAN THE
PREVIOUS FORECAST WITH SLIGHTLY HIGHER DEWPOINTS. THIS COMBINED WITH
THE EXPECTED CLOUD COVER SHOULD LEAD TO MIN T A BIT WARMER THAN THE
PREVIOUS FORECAST. HOURLY GRIDS HAVE BEEN UPDATED ACCORDINGLY.
UPDATE ISSUED AT 928 PM EDT SAT JUL 12 2014
WITH WINDS DECOUPLING IN THE VALLEYS...TEMPS HAVE DROPPED AND DEW
POINTS HAVE JUMPED. HAVE UPDATED GRIDS TO ACCOUNT FOR THE LATEST OBS.
THE FORECAST FOR OVERNIGHT REMAINS UNCHANGED.
UPDATE ISSUED AT 614 PM EDT SAT JUL 12 2014
A SIGNIFICANT AMOUNT OF CIRRUS HAS MOVED INTO THE REGION...BUT IT
WAS GRADUALLY DISSIPATING. INCREASED SKY COVER FOR EARLY THIS
EVENING...BUT STAYED WITH A TREND TOWARD THE LOWER VALUES OF THE
PREVIOUS FORECAST FOR LATE TONIGHT. DRY SURFACE AIR AND WARM AIR
ADVECTION TONIGHT WOULD FAVOR SOME RIDGE/VALLEY TEMPERATURE
DIFFERENCES...AND HAVE LOWERED VALLEY MINS JUST A BIT FOR TONIGHT.
WITHOUT OVERCAST SKIES OR SIGNIFICANT WIND...CLIMATOLOGY STRONGLY
FAVORS AT LEAST SOME FOG IN THE DEEPER VALLEYS AT THIS TIME OF YEAR.
SO...DESPITE THE DRY AIR...HAVE ADDED SOME PATCHY FOG IN VALLEYS FOR
LATE TONIGHT...BUT PREVIOUS THINKING OF LESS SUBSTANTIAL FOG THAN IN
RECENT NIGHTS SHOULD STILL PLAY OUT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 315 PM EDT SAT JUL 12 2014
ISOLATED CONVECTION MAINLY TIED TO TERRAIN IS EXPECTED TO REMAIN TO
OUR SOUTH AND SOUTHEAST OVER SW VA AND THE HIGHER TERRAIN OF TN AND
NC FOR THE REMAINDER OF THIS AFTERNOON. THE AREA OF SHOWERS AND
THUNDERSTORMS OVER WESTERN INDIANA AND WESTERN KY IS AHEAD OF A NEARLY
STATIONARY WARM FRONTAL BOUNDARY THAT REPRESENTS THE LEADING EDGE OF
70 PLUS DEW POINT TEMPERATURES OVER IL AND MO. SATELLITE...RADAR AND
LIGHTNING TRENDS ALL SHOW CONTINUING WEAKENING OF CONVECTION OVER
INDIANA...BUT THERE HAS BEEN SOME DEVELOPMENT INTO WESTERN KY. THE
SHORT RANGE RAP AND HRRR CONTINUE TO SHOW OVERALL DECAY OF CONVECTION
TO OUR WEST...AND ONLY IMPACT IN OUR AREA WILL BE SOME INCREASE IN
HIGH LEVEL CLOUDS.
WITH VERY DRY LOW LEVEL AIR IN PLACE IN EASTERN KY THIS
AFTERNOON...NOTE DEW POINT AS LOW AS 48 AT QUICKSAND MESONET...THERE
WILL BE EVEN LESS FOG TONIGHT AS THERE WAS LAST NIGHT. GUIDANCE NOT
HANDLING THE DRY AIR VERY WELL...AND EXPECT THERE TO BE ABOUT A 5
DEGREE RIDGE VALLEY TEMPERATURE SPLIT FOR TONIGHT.
ON SUNDAY INSTABILITY WILL INCREASE AHEAD OF AN APPROACHING COLD
FRONT WITH MUCAPE IN EXCESS OF 4000 J/KG DEVELOPING IN A CORRIDOR
NORTH OF THE OH RIVER ACROSS SOUTHERN IN AND OH. BEST SHEAR WILL ALSO
BE NORTH OF THE OH RIVER SUNDAY AFTERNOON AND CURRENT THINKING IS
THAT THUNDERSTORMS WILL DEVELOP ACROSS OH AND INDIANA AND THEN
PROGRESS INTO NORTHERN PARTS OF THE FORECAST AREA LATE SUNDAY
AFTERNOON OR SUNDAY NIGHT. AT THE SAME TIME SOME ISOLATED TO
SCATTERED CONVECTION MAY DEVELOP OVER THE SOUTHEAST MOUNTAINS SUNDAY
AFTERNOON. THIS WOULD ALSO BE IN A CORRIDOR OF SLIGHTLY GREATER
INSTABILITY AND ALSO PARTIALLY TIED TO THE HIGHER TERRAIN. THE MODELS
HAVE BEEN CONSISTENT AT HINTING AT THIS POSSIBILITY IN THE SE
FORECAST AREA. CONSIDERING ALL THIS WILL BRING CHANCE PROBABILITY OF
SHOWERS AND THUNDERSTORMS TO THE SOUTHEAST AND NORTHERN PARTS OF THE
FORECAST AREA FIRST ON SUNDAY...WITH THE CENTRAL AND SOUTHWEST PARTS
OF THE FORECAST AREA THE LAST TO SEE THE RAIN CHANCES.
THE CONVECTION THAT DEVELOPS TO OUR NORTH ON SUNDAY HAS SEVERE
POTENTIAL...BUT AS IT MOVES INTO OUR AREA SUNDAY NIGHT AWAY FROM
BEST SUPPORT...THE SEVERE THREAT WILL DECREASE. THE DAY 2 SEVERE
WEATHER OUTLOOK WITH ONLY OUR FAR NW COUNTIES HAVING A SLIGHT RISK OF
SEVERE WEATHER THROUGH 12Z MONDAY CONTINUES TO LOOK GOOD. WITH PW
INCREASING THROUGH SUNDAY NIGHT TO 1.7 TO POSSIBLY GREATER THAN 2
INCHES SOME HEAVY RAINERS ARE DEFINITELY A POSSIBILITY SUNDAY NIGHT. MUCH
OF THE AREA HAS BEEN PLACED IN THE DAY 2 EXCESSIVE RAINFALL OUTLOOK
VALID 00Z MONDAY TO 00Z TUESDAY. FLASH FLOOD GUIDANCE IS FAIRLY HIGH
HOWEVER...AND PART OF THE AREA IS CURRENTLY IN D1 DROUGHT. INITIALLY...
AT LEAST FOR SUNDAY NIGHT...WHICH IS THE FIRST HALF OF THIS OUTLOOK
PERIOD THE FLASH FLOOD THREAT LOOKS BE ISOLATED AT WORST.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 315 PM EDT SAT JUL 12 2014
THE GFS IS SHOWING SOME DECENT CONTINUITY THROUGH THE LAST FEW
CYCLES BUT STILL APPEARS OUTSIDE THE RANGE OF OTHER SOLUTIONS AND
TOO PROGRESSIVE...ESPECIALLY CONSIDERING THE EXPECTED AMPLITUDE OF
THE MID AND UPPER LEVEL PATTERNS. THE ECMWF...WHICH HAS BEEN MORE
CONSISTENT IS ADVERTISING A SLOWER SYSTEM THAT PUNCHES FURTHER SOUTH
THAN OTHER MODELS AND IS ON THE SLOWER SIDE OF THE ENVELOPE OF
SOLUTIONS THROUGH THE MID TERM. JUST THE SAME MODELS ROUGHLY AGREE
ON THE OVERALL SCENARIO OF THE LARGE SCALE PATTERN. THE MAIN...AND
MOST SIGNIFICANT DIFFERENCES CROP UP RESOLVING SURFACE FEATURES AND
THE TIMING OF SFC SYSTEMS THROUGH OUR AREA. ATTM TENDENCY IS TO LEAN
TOWARDS THE ECMWF SOLUTION THROUGH THE MID RANGE AFTER USING A
CONSENSUS SOLUTION TO INITIALIZE THE EXTENDED PORTION OF THE
FORECAST PACKAGE. WILL STICK TO A BLENDED APPROACH FOR THE END OF
THE FORECAST WINDOW AS ADDITIONAL ENERGY EMERGES FROM THE PACIFIC
NW/CANADA CAUSING THE PATTERN TO BECOME LESS AMPLIFIED...BUT ALSO
ALLOWING FOR THE MEAN STORM TRACK TO RETURN NORTHWARD CLOSER TO OUR
NECK OF THE WOODS.
HEIGHTS FALL DROP STEADILY THROUGH THE FIRST HALF OF THE PERIOD AS A
SPLITTING UPPER LEVEL LOW DROPS A SIGNIFICANT PORTION OF ITS ENERGY
INTO THE THE UPPER MIDWEST AND GREAT LAKES...RESULTING IN A LARGE
DEEP TROUGH ACROSS THE ENTIRE EASTERN CONUS BY MID WEEK. SURFACE
FRONTAL ZONE WILL DROP SOUTHWARD ALONG THE OHIO RIVER BY LATE SUNDAY
OR SUNDAY NIGHT. A SECOND STRONGER...FASTER FRONTAL BOUNDARY WILL
FOLLOW QUICKLY BEHIND THE FIRST SLIDING THROUGH OUR AREA AS SOON AS
MONDAY NIGHT...OR AS LATE AS TUESDAY AFTERNOON DEPENDING ON WHICH
MODEL YOU LOOK AT. IT STILL SEEMS LIKE THE GFS IS HAVING TROUBLE
RESOLVING THE TIMING OR PASSAGE OF THESE TWO FRONTAL BOUNDARIES...
WITH A TENDENCY TO MERGE EACH DISTINCT BOUNDARY INTO A SINGLE FINAL
SYSTEM THAT MOVES THROUGH EASTERN KENTUCKY TOO QUICKLY.
WE ARE STILL LOOKING AT THE POTENTIAL FOR SOME SEVERE WEATHER THOUGH
THE TIME OF DAY AND EXACT AMOUNT OF SUNLIGHT WILL BE SOMETHING THAT
WILL NEED TO BE FACTORED IN. AS IS TYPICAL...THE NAM IS CONSIDERABLY
MORE UNSTABLE IN THE BOUNDARY LAYER BECAUSE OF ITS WET BIAS. THE NAM
IS ALSO SHOWING HIGHER BULK SHEAR VALUES THROUGH THE EARLY MONDAY
MORNING TO MONDAY AFTERNOON TIME FRAME. PWATS AND LIFT THROUGH THE
COLUMN ARE MUCH MORE IMPRESSIVE AS WELL WHEN COMPARED TO THE GFS.
EXPECT THE TRUTH WILL LIE SOMEWHERE IN THE MIDDLE THOUGH THAT MAY BE
A BAD ASSUMPTION GIVEN THE GFS MIGHT BE HAVING TROUBLE
DISTINGUISHING SURFACE AND BOUNDARY LAYER DETAILS. FREEZING LEVELS
REMAIN HIGH. SO WHILE SOME HEAVY RAIN CAN NOT BE RULED OUT...STORM
MOTION IS HIGH ENOUGH THAT HYDRO PROBLEMS SHOULD NOT BECOME TOO MUCH
OF A PROBLEM...AT LEAST BASED ON CURRENT GUIDANCE. BIGGEST THREAT
FOR SEVERE WEATHER WILL GENERALLY LIE ACROSS OUR BLUE GRASS COUNTIES
SUNDAY...BUT THEN EXPAND SOUTHEASTWARD TO ENCOMPASS OUR ENTIRE
FORECAST AREA BY MONDAY.
WE ARE STILL LOOKING AT UNSEASONABLE COLD WEATHER FOR THE PEAK OF
SUMMER HEATING THROUGH THE MIDDLE OF UPCOMING WEEK. ECMWF H850 TEMPS
DROP TO AROUND 8C AND THE GFS HAS TRENDED TOWARDS THE ECMWF. ECMWF
MOS GUIDANCE IS QUITE COOL WITH AFTERNOON HIGHS IN THE LOWER TO MID
70S AND LOWS SOLIDLY IN THE 50S FROM TUESDAY THROUGH FRIDAY. WHILE
THERE IS SOME MODERATION TOWARDS THE END OF THE WEEK...THERE IS A
GOOD POTENTIAL FOR SOME RECORD COLD MORNING LOWS AND EVEN A FEW
RECORD LOW MAXES. GFS MOS IS CONSIDERABLY WARMER BUT HAS SHOWN SIGNS
OF COOLING. PAST EXPERIENCE HAS TAUGHT THAT A BLEND OF GUIDANCE
MAKES A BEST FIRST GUESS...AFTER A TWEAK TOWARDS THE TYPICALLY MORE
ACCURATE ECMWF MOS.
ADDITIONAL ENERGY MOVING OUT OF THE NORTHWEST AND INTO THE BASE OF
THE BY THEN LIFTING EASTERN CONUS TROUGH WILL BRING A THREAT OF RAIN
BACK INTO THE FORECAST AREA AT THE END OF THE WEEK AND INTO THE
WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 155 AM EDT SUN JUL 13 2014
PREDOMINANTLY VFR WITH LIGHT WINDS IS EXPECTED TO CONTINUE FOR MUCH
OF THE PERIOD. AN EXCEPTION WILL BE LOCALIZED FOG IN DEEP VALLEYS
THROUGH 12Z OR 13Z. THERE COULD ALSO BE A FEW SHOWERS AND
THUNDERSTORMS POPPING UP AROUND 16Z AND AFTER...WITH LOCALIZED
RESTRICTIONS TO CIGS/VSBY. AT LEAST ISOLATED TO SCATTERED SHRA AND
TSRA SHOULD MOVE INTO THE NORTHWEST PART OF THE AREA AFTER 22Z WITH
SOME OR ALL OF THE TAF SITES POSSIBLY AFFECTED DURING THE LAST 6
HOURS OF THE PERIOD. WITH THAT IN MIND...OPTED FOR A MENTION OF VCTS
LATE IN THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...SBH
LONG TERM...RAY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
355 AM EDT SUN JUL 13 2014
.SYNOPSIS...
HIGH PRESSURE IN THE WESTERN ATLANTIC WILL KEEP SOUTHERLY FLOW
ACROSS THE MID ATLANTIC THROUGH MONDAY. A COLD FRONT WILL CROSS
THE AREA TUESDAY. HIGH PRESSURE WILL BUILD ALONG THE EASTERN
SEABOARD FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SCT-BKN MID-HIGH CLOUDS CONTINUE TO STREAM THROUGH THE CWA EARLY
THIS MORNING...FOUND WITHIN A WARM ADVECTION ZONE WELL AHEAD OF AN
UPPER TROUGH DIGGING INTO THE UPPER MIDWEST. SEVERAL SETS OF
GUIDANCE INCLUDING THE 00Z NAM AND RECENT RUNS OF THE HRRR AND LWX
WRF-ARW SUGGEST A FEW SHOWERS DEVELOPING/PROPAGATING EASTWARD ACROSS
THE NORTHERN VIRGINIA PIEDMONT/LOWER SOUTHERN MARYLAND THROUGH
DAYBREAK. ACCORDING TO THESE MODELS...SOME DEVELOPMENT SHOULD HAVE
ALREADY TAKEN PLACE /BY 06Z/ AND THE RADAR HAS YET TO INDICATE AS
SUCH EXCEPT FOR AN ISOLATED SHOWER NEAR MARTINSBURG. DESPITE WARM
ADVECTION...BELIEVE THIS IS OVERDONE AND WILL CONTINUE WITH A DRY
FORECAST THROUGH DAYBREAK /EXCEPT FOR ACCOUNTING FOR THE
AFOREMENTIONED ISOLATED SHOWER/ AND AMEND IF TRENDS CHANGE. WITH
CLOUDS OVERHEAD...ANY EARLY MORNING FOG SHOULD BE PATCHY AND MAINLY
RELEGATED TO THE USUAL FOG PRONE AREAS.
WITH SOUTH/SOUTHWEST FLOW IN PLACE...ATMOSPHERE WILL CONTINUE TO
MOISTEN THROUGH THE DAY WITH MODELS INDICATING PRECIPITABLE WATER
VALUES INCREASING TO 1.75 TO 2 INCHES BY THE END OF TODAY. WARM
TEMPERATURES AND A MOIST ENVIRONMENT ALONG WITH SOME BREAKS IN THE
MID CLOUDS THIS MORNING WILL ALLOW FOR INCREASING INSTABILITY THIS
AFTERNOON...POSSIBLY IN EXCESS OF 1000 J/KG. PRESENCE OF A TROUGH
WILL ALSO BE APPARENT AND BELIEVE THIS WILL HELP TO TRIGGER ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS DURING THE AFTERNOON.
INITIATION WOULD LIKELY OCCUR FIRST NEAR/WEST OF THE BLUE
RIDGE...BUT CONVECTION THEN MAY MOVE EASTWARD THROUGH EARLY EVENING.
THIS IS MORE IN LINE WITH 00Z NAM/03Z SREFS GUIDANCE. WHILE SHEAR
MAY INITIALLY BE ON THE WEAK SIDE...INSTABILITY MAY BE ENOUGH TO
SUPPORT A FEW STRONG TO SEVERE THUNDERSTORMS WITH LOCALLY DAMAGING
WIND GUSTS.
LWX WRF-ARW ACTUALLY DOESN/T PROJECT A LOT OF AFTERNOON
CONVECTION...INSTEAD FOCUSING MORE ON ORGANIZED CONVECTION IN
PENNSYLVANIA THAT WOULD SHIFT SOUTHEAST DURING THE EVENING. AS
MENTIONED ABOVE...WHILE BELIEVE THAT THERE WOULD BE SOME INITIAL
CONVECTION IN THE AFTERNOON/EARLY EVENING EVEN THOUGH IT/S NOT WELL
DEPICTED ON THE WRF-ARW...ALSO AM CONCERNED THAT ORGANIZED
CONVECTION TO THE NORTH COULD SINK SOUTHEASTWARD DURING BY LATE
EVENING. THERE ARE OBVIOUSLY SOME UNCERTAINTIES WITH THE
EVOLUTION/MOVEMENT/TIMING OF SUCH CONVECTION AND THUS AM INCLINED TO
CONTINUE CHANCE POPS INTO THE NIGHT WITH THE HIGHEST POPS ACROSS THE
NORTHERN PORTION OF THE CWA. SHEAR MAY BE A BETTER BY THAT TIME THIS
CONVECTION WOULD AFFECT THE CWA AND THUS A DAMAGING WIND GUST RISK
MAY CONTINUE WELL INTO THE EVENING.
BIAS CORRECTED SREFS HAS PERFORMED WELL FOR TEMPERATURES
RECENTLY...AND USED THIS WITH A LITTLE BCADJMAV FOR MAXIMA/MINIMA.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
MID-ATLANTIC WILL CONTINUE TO RESIDE IN A WARM SECTOR MONDAY THROUGH
MONDAY NIGHT AS A COLD FRONT GRADUALLY WORKS SOUTHEASTWARD...LIKELY
RESIDING JUST NORTHWEST OF THE CWA LATE MONDAY NIGHT.
IT IS UNCLEAR WHERE THERE WILL BE AN EARLY MORNING LULL IN
CONVECTION OR IF THERE COULD BE ONGOING CONVECTION ACROSS THE
NORTHWEST PORTION OF THE CWA. WHETHER THIS IS THE CASE OR
NOT...MONDAY AFTERNOON HAS THE POTENTIAL TO BE ACTIVE AS SREFS
INDICATES SUFFICIENT CAPE AND SHEAR BY AFTERNOON TO SUPPORT THE
POTENTIAL FOR SEVERE THUNDERSTORMS. WHILE THE PRIMARY THREAT WILL BE
DAMAGING WIND GUSTS...LARGE HAIL AND ISOLATED TORNADOES CAN/T BE
RULED OUT. GIVEN HIGH PRECIPITABLE WATER ENVIRONMENT...SOME OF THE
THUNDERSTORMS MAY PRODUCE HEAVY RAINFALL WHICH MAY POSE A FLASH
FLOODING RISK ACROSS THE CWA.
WHILE BOTH THE SEVERE RISK AND CONVECTIVE COVERAGE SHOULD DIMINISH
IN THE EVENING...WILL CONTINUE WITH CHANCE POPS OVERNIGHT GIVEN
MOIST ATMOSPHERE AND COLD FRONT JUST TO THE NORTHWEST OF THE CWA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AT THE START OF TUE...THE CDFNT...WHILE APPROACHING...WL STILL
RESIDE NW OF CWFA. THERE WL BE AN EVER STEEPENING TROF AXIS ALONG
THE I-95 CORRIDOR THAT WL SERVE AS A FOCUSING MECHANISM. SUSPECT
THAT THE TRUE CFP WL BE TOUGH TO DETERMINE AS ENERGY FM THE FNT WL
BE ABSORBED BY THE TROF DURING THE COURSE OF THE DAY. BY MID-LT
AFTN...THAT TRANSITION WL BE COMPLETE.
SUCH A PROGRESSION WL GNLY KEEP THE MOST UNSTBL AIR ACRS THE
TIDEWATER AND DELMARVA. HWVR...PLENTY OF SHEAR WL BE PRESENT...THX
TO THE RRQ OF A 120 KT UPR JETMAX. GIVEN KINEMATICS AND FORCED SFC
CNVGNC/ASCENT...STILL THINK THAT LKLY POPS THE WAY TO GO. SINCE AMS
WL STILL BE VERY MOIST...W/ DEWPTS IN THE UPR 60S OR NEAR 70F AND
PWAT 1.5-2.0 INCHES...ANY TSRA WL BE HVY RAINERS. WHILE THE BEST
COMBO OF INSTBY/LIFT WL BE SE OF AREA...IT/LL STILL BE PSBL TO HV
LCL WET MICROBURSTS OR HAIL SUPPORTING STRONG UPDRAFTS. THEREFORE...
THE SVR WORDING WL REMAIN IN HWO. EVOLUTION OF SVR PROBS WL PARTLY
BE DETERMINED BY CDFNTL PROGRESS AND MAY BE INHIBITED BY DEBRIS
CLDS. MON LOOKS LIKE THE MORE VIOLENT DAY...BUT THERE IS A MARGINAL
RISK TUE AS WELL.
A SHARP H5 TROF AXIS WL FOLLOW TUE NGT-WED. AM NOT QUITE SURE HOW
QUICKLY THE SFC BNDRY WL CLEAR AREA AT FIRST. AM THEREFORE HOLDING
ONTO SOME POPS ALONG THE BAY/SRN MD TUE NGT. HWVR...ONCE THE UPR
AXIS SWEEPS THRU...ITLL KICK THE FNT TO THE COAST. COOL DRY CNDN AIR
WL STREAM INTO CWFA THEREAFTER. THAT/LL SET UP SVRL ATYPICAL JULY
DAYS.
BY DAYS 6-7 /FRI-SAT/...HIPRES WL MV OFFSHORE...SETTING UP RETURN
FLOW AND PERHAPS AN APPROACHING WMFNT. TSRA CHCS RETURN TO THE FCST
DUE TO THE INHERENT INSTBY/LIFT.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
PLENTY OF MID CLOUDS WERE MOVING ACROSS THE CWA AGAIN EARLY THIS
MORNING AND THIS WILL INHIBIT FOG FORMATION. IF SOME CLEARING
OCCURS AT CHO/MRB...BRIEF MVFR IS POSSIBLE BY DAYBREAK.
OTHERWISE...EXPECT VFR EARLY THIS MORNING WITH JUST A LOW
PROBABILITY OF STRATUS SNEAKING INTO MTN/BWI. FOR THE REST OF THE
DAY...A FEW THUNDERSTORMS ARE EXPECTED TO DEVELOP NEAR A TROUGH THIS
AFTERNOON MOVING EASTWARD THROUGH EARLY EVENING. THIS MAY WARRANT
VCTS INCLUSION BY 12Z TAF TIME. IT/S ALSO POSSIBLE THAT
THUNDERSTORMS IN PENNSYLVANIA SLIDE SOUTHEASTWARD BY LATE
EVENING...ALTHOUGH CONFIDENCE IN EXACT EVOLUTION/TIMING IS LOW.
LEE TROUGH AND A MOIST/UNSTABLE ENVIRONMENT WILL LEAD TO MORE
NUMEROUS THUNDERSTORMS FOR MONDAY...PARTICULARLY FOR THE AFTERNOON.
HEAVY RAINFALL/STRONG WINDS WILL BE POSSIBLE IN STORMS.
SCT-NMRS TSRA DURING THE DAY TUE...PERHAPS LINGERING INTO THE EVNG
FOR THE METROS. FLGT RESTRICTIONS XPCTD W/IN STORMS ALTHO SHUD HV
HEALTHY PDS OF VFR AS WELL.
WED-THU...HIPRES BLDS. VFR.
&&
.MARINE...
SOUTHERLY WINDS CONTINUE TO CHANNEL UP THE BAY EARLY THIS MORNING.
SPEEDS HAVE DIMINISHED A LITTLE THE PAST FEW HOURS...BUT TPLM2
CONTINUES TO GUST AOA 20 KT. SCA REMAINS IN EFFECT TIL 10Z. WINDS
SHOULD DIMINISH SOME THIS MORNING BUT THE LULL MAY NOT BE THAT LONG
AS LATER THIS AFTERNOON INTO THIS EVENING SOUTHERLY FLOW IS LIKELY
TO BE IN SCA RANGE AGAIN. HAVE EXTENDED PREVIOUS SCA INTO THE NIGHT.
AM UNCERTAIN WHETHER SCA CONDITIONS WILL CONTINUE INTO MONDAY OR
NOT...IT/LL BE CLOSE BUT DON/T HAVE THE CONFIDENCE TO EXTEND
ADVISORY THAT FAR YET. ANOTHER NOTE IS THAT THUNDERSTORMS THIS
AFTERNOON/EVENING AND AGAIN MONDAY MAY PRODUCE STRONG WIND GUSTS.
TROF AXIS OVER WATERS TUE MRNG...TO BE JOINED BY CDFNT TUE AFTN-NGT.
SINCE THERE WL BE A BNDRY NEARLY OVERHEAD...GRADIENT FLOW WL BE
LGT-- SLY BCMG WLY. HWVR...THIS SETUP WL PRODUCE NMRS TSRA...EACH WL
CONTAIN A GUSTY WND THREAT AS WELL AS VERY HEAVY RAIN. THUS...SMW/S
XPCTD.
COOLER/DRIER AIR WL SURGE INTO AREA WED AND STAY THRU THU. GDNC NOW
STARTING TO PICK UP ON MIXING POTL IN THE MID BAY WED. WL ADD PSBL
SCA TO SYN/HWO.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS HAVE INCREASED TO 1/2 TO 2/3RDS FOOT ON THE BAY AS
SOUTHERLY FLOW STRENGTHENS. THIS MODEST INCREASE AND A FULL MOON
IS ALL THATS NEEDED TO REACH MINOR THRESHOLD AT ANNAPOLIS FOR HIGH
TIDE EARLY THIS UPCOMING MORNING. HAVE ISSUED CSTL FLOOD ADVY.
DEPARTURES OF 1/4 TO 1/3 FT ON THE POTOMAC CAUSING NO ISSUES AT
THIS TIME.
THE MORNING TIDE IS THE HIGHER OF THE TWO ASTRONOMICALLY. WE WILL
BE IN A SIMILAR SITUATION MON MORNING...W/ PERHAPS SW DC GETTING
IN ON THE ACT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
ANZ531>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM EDT
MONDAY FOR ANZ532>534-537-540-541-543.
&&
$$
SYNOPSIS...HTS
NEAR TERM...BPP
SHORT TERM...BPP
LONG TERM...HTS
AVIATION...BPP/HTS
MARINE...BPP/HTS
TIDES/COASTAL FLOODING...HTS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
317 AM EDT SUN JUL 13 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 422 PM EDT SAT JUL 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID/UPPER LEVEL LOW FROM
WRN HUDSON BAY INTO NRN MANITOBA. A LINE OF SHRA/TSRA THROUGH SRN
MANITOBA WAS ASSOCIATED WITH A PROMINENT SHORTWAVE TROUGH AND COLD
FRONT NEARING WINNIPEG. FARTHER SOUTH...A WEAKER SHRTWV FROM ERN MN
INTO WRN WI COMBINED WITH MORE ABUNDANT MOISTURE (PWAT VALUES AROUND
1.5 INCH) SUPPORTED AN AREA OF SHRA AND ISOLD TSRA FROM SE MN INTO
CNTRL AND NRN WI. CONVERGENCE ALON LAKE SUPERIOR AND LAKE MICHIGAN
LAKE BREEZE BOUNDARIES WHERE MLCAPE HAS CLIMBED TO NEAR 1K J/KG HAS
TRIGGERED ISOLD ISOLD SHRA/TSRA FROM FAR NW DELTA COUNTY INTO NRN
SCHOOLCRAFT COUNTY.
TONIGHT...EXPECT ADDITIONAL SHRA/TSRA DEVELOPMENT ALONG THE LAKE
BREEZE BOUNDARIES INLAND FROM CNTRL INTO ERN UPPER MI INTO THIS
EVENING TIL THE LOSS OF DAYTIME HEATING. THERE IS MORE UNCERTAINTY
REGARDING THE SHRA/TSRA OVER NRN WI AS SEVERAL HIGH RES MODELS
SUGGEST THAT THEY MAY EXPAND INTO SRN UPPER MI AND POSSIBLE TOWARD
MQT/P53 AS THE WI SHRTWV ADVANCES TO THE EAST.
HOWEVER...RADAR/SATELLITE TRENDS WOULD FAVOR KEEPING HIGHER
COVERAGE/POPS MAINLY OVER THE FAR S/SE CWA. ADDITIONAL SHRA AND
POSSIBLY ISOLD THUNDER WILL BE POSSIBLE AS THE MANITOBA FRONT/SHRTWV
MOVE INTO UPPER MI OVERNIGHT. HOWEVER...SINCE THE PCPN FOCUS ARRIVES
WHEN MUCAPE HAS DIMINISHED TO 400 J/KG OR LESS...ONLY SLIGHT
CHANCE POPS WERE INCLUDED.
SUNDAY...AFTER ANY LINGERING SHRA DEPART FROM THE FAR ERN CWA
EARLY...BREEZY AND COOLER WEATHER IS EXPECTED BEHIND THE COLD FRONT.
HOWEVER...WITH WNW WINDS AND 850 MB TEMPS IN THE 6C-8C RANGE...MAX
READINGS SHOULD STILL CLIMB INTO THE UPPER 60S TO LOWER 70S FROM NW
TO SE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 316 AM EDT SUN JUL 13 2014
MAIN FOCUS IN THE LONG TERM IS WITH POPS/TEMPS MON-WED.
MODELS CONTINUE TO DIFFER ON EXACT TRACK/STRENGTH DETAILS OF A
CLOSED UPPER LOW SET TO MOVE ACROSS THE AREA MON INTO TUE. THE LOW
IS CURRENTLY HANGING OUT OVER EXTREME NWRN ONTARIO AND IT SET TO
SPLIT IN TWO TODAY...SENDING A PIECE OF ENERGY INTO QUEBEC WHILE THE
OTHER ROTATES OVER OR NEAR THE CWA. MODELS PROBABLY WILL NOT BE IN
BETTER AGREEMENT UNTIL THE 00Z/14 RUNS WHICH WILL BE AFTER A LOT OF
THE ENERGY HAS SPLIT OUT OF THE SYSTEM. AS IT STANDS NOW...AT LEAST
MUCH OF THE CWA SHOULD SEE RAIN MON INTO MON NIGHT...WITH PRECIP
LINGERING INTO TUE. FACTORS CONTRIBUTING TO THE PRECIP INCLUDE THE
ENERGY/HEIGHT FALLS FROM THE UPPER LOW MOVING OVERHEAD...DAYTIME
INSTABILITY RESULTING FROM THE ANOMALOUSLY COLD TEMPS IN THE UPPER
LOW...AND NLY FLOW OFF LAKE SUPERIOR BETWEEN TROUGHING E AND A HIGH
WELL TO THE W. BEST CHANCES FOR RAIN BY FAR WILL BE ON MON DURING
PEAK HEATING...WHEN LIKELY POPS ARE IN THE FORECAST. THERE MAY WELL
BE SOME DRY SPOTS DEPENDING ON EXACT TRACK/STRENGTH OF THE COMPACTS
UPPER LOW...SO THOSE DETAILS WILL NEED TO BE MONITORED BY LATER
SHIFTS WHEN MODELS /HOPEFULLY/ COME INTO BETTER AGREEMENT. HAVE HIGH
TEMPS IN THE 50S W AND AROUND 60 S AND E. THESE TEMPS WILL BE AROUND
20 DEGREES BELOW NORMAL.
WITH THE N WINDS AND COLD CORE OF THE LOW STILL OVER THE CWA TUE
MORNING...HAVE SLIGHT CHANCE TO LOW END CHANCE POPS
LINGERING...MAINLY IN THE MORNING. THE UPPER LOW SHUNTS QUICKLY TO
THE NE ON TUE...WITH A SFC HIGH BECOMING MORE DOMINANT OVER THE WRN
CWA AS THE DAY PROGRESSES. HIGH TEMPS WILL LIKELY STRUGGLE TO REACH
60 IN MOST LOCATIONS...WITH SOME LAKE SUPERIOR SHORELINE AREAS
POSSIBLY NOT GETTING ABOVE 50. THESE TEMPS WILL BE AROUND
20-25 DEGREES BELOW NORMAL.
THINK THE MIN TEMP FORECAST FOR TUE NIGHT COULD BE TOO WARM...BUT
ONLY IF ENOUGH CLEARING OCCURS. WITH THE COLD DAY ON TUE...CLEARING
/OF UNCERTAIN MAGNITUDE/ TUE NIGHT FROM W TO TO E MAY LEAD TO SOME
COLDER MIN TEMPS OVER WRN UPPER MI. AMONG THE REASONS FOR THE
UNCERTAINTY ARE POSSIBLE SHORTWAVE ENERGY TRACKING AROUND THE
DEPARTING LOW/TROUGH AS INDICATED BY THE ECMWF AND THE POSSIBILITY
THAT THE WINDS MAY STAY UP ENOUGH TO KEEP TEMPS FROM BOTTOMING OUT
AS MUCH.
REMAINING UPPER TROUGHING WILL CONTINUE TO WEAKEN WED AS UPPER
RIDGING BUILDS TOWARD THE CWA. SKIES WILL BE MOSTLY SUNNY...AND THE
AIRMASS OVERALL WARMER...WHICH WILL ALLOW FOR WARMER SFC TEMPS WITH
HIGHS FROM AROUND 60 ALONG LAKE SUPERIOR TO AROUND 70 INLAND.
FORECAST WED NIGHT THROUGH NEXT SAT LOOKS PRETTY QUIET. NORMAL
UNCERTAINTY EXISTS DURING THIS PERIOD...BUT WITH WEAK UPPER RIDING
BUILDING INTO THE CENTRAL CONUS...SIGNIFICANT PRECIP IS NOT
EXPECTED. IN GENERAL...A WARMING TREND IS EXPECTED INTO THE WEEKEND.
BY SAT...HIGH TEMPS COULD REACH 80 OVER THE INTERIOR W.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 104 AM EDT SUN JUL 13 2014
VFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD AT
KIWD/KCMX/KSAW. HOWEVER...SINCE PCPN OCCURRED AT KSAW...IT`S
POSSIBLE FOG AND STRATUS COULD DEVELOP FOR A TIME OVERNIGHT BEFORE
WINDS PICK UP AHEAD OF FAST APPROACHING COLD FRONT. BECAUSE
UNCERTAINTY IS HIGH...MENTION WAS NOT INCLUDED. ALTHOUGH SHRA ALONG
APPROACHING COLD FRONT ARE WEAKENING/DISSIPATING...COLD FRONT MAY
STILL BRING -SHRA AND SOME GUSTY WINDS TO KIWD/KCMX IN THE NEXT
COUPLE OF HRS. OTHERWISE...BEHIND COLD FRONT...GUSTY WINDS ARE
EXPECTED TODAY WITH ALL TERMINALS GUSTING 20-30KT. STRONGEST WINDS
WILL BE AT KCMX WHICH IS MORE EXPOSED WITH A WNW WIND.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT SAT JUL 12 2014
SOUTHWEST WINDS THIS EVENING WILL SHIFT SHARPLY TO THE WEST LATE
TONIGHT AS A COLD FRONT ARRIVES. THERE MAY BE SOME WIND GUSTS UP
TO 25 KTS AT LEAST BRIEFLY LATE TONIGHT OVER WEST AND NORTH CENTRAL
LK SUPERIOR BEHIND THE FRONT. AREAS OF FOG ARE CURRENTLY OVER LAKE
SUPERIOR WILL DISSIPATE ON SUNDAY IN WAKE OF THE STRONGER FRONT AS
STRONG DRY ADVECTION TAKES OVER. EXPECT NORTHWEST WINDS TO 20 KTS AT
TIMES INTO EARLY THIS WEEK IN WAKE OF THE COLD FRONT AND AS HIGH
PRESSURE BUILDS OVER THE NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
105 AM EDT SUN JUL 13 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 422 PM EDT SAT JUL 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID/UPPER LEVEL LOW FROM
WRN HUDSON BAY INTO NRN MANITOBA. A LINE OF SHRA/TSRA THROUGH SRN
MANITOBA WAS ASSOCIATED WITH A PROMINENT SHORTWAVE TROUGH AND COLD
FRONT NEARING WINNIPEG. FARTHER SOUTH...A WEAKER SHRTWV FROM ERN MN
INTO WRN WI COMBINED WITH MORE ABUNDANT MOISTURE (PWAT VALUES AROUND
1.5 INCH) SUPPORTED AN AREA OF SHRA AND ISOLD TSRA FROM SE MN INTO
CNTRL AND NRN WI. CONVERGENCE ALON LAKE SUPERIOR AND LAKE MICHIGAN
LAKE BREEZE BOUNDARIES WHERE MLCAPE HAS CLIMBED TO NEAR 1K J/KG HAS
TRIGGERED ISOLD ISOLD SHRA/TSRA FROM FAR NW DELTA COUNTY INTO NRN
SCHOOLCRAFT COUNTY.
TONIGHT...EXPECT ADDITIONAL SHRA/TSRA DEVELOPMENT ALONG THE LAKE
BREEZE BOUNDARIES INLAND FROM CNTRL INTO ERN UPPER MI INTO THIS
EVENING TIL THE LOSS OF DAYTIME HEATING. THERE IS MORE UNCERTAINTY
REGARDING THE SHRA/TSRA OVER NRN WI AS SEVERAL HIGH RES MODELS
SUGGEST THAT THEY MAY EXPAND INTO SRN UPPER MI AND POSSIBLE TOWARD
MQT/P53 AS THE WI SHRTWV ADVANCES TO THE EAST.
HOWEVER...RADAR/SATELLITE TRENDS WOULD FAVOR KEEPING HIGHER
COVERAGE/POPS MAINLY OVER THE FAR S/SE CWA. ADDITIONAL SHRA AND
POSSIBLY ISOLD THUNDER WILL BE POSSIBLE AS THE MANITOBA FRONT/SHRTWV
MOVE INTO UPPER MI OVERNIGHT. HOWEVER...SINCE THE PCPN FOCUS ARRIVES
WHEN MUCAPE HAS DIMINISHED TO 400 J/KG OR LESS...ONLY SLIGHT
CHANCE POPS WERE INCLUDED.
SUNDAY...AFTER ANY LINGERING SHRA DEPART FROM THE FAR ERN CWA
EARLY...BREEZY AND COOLER WEATHER IS EXPECTED BEHIND THE COLD FRONT.
HOWEVER...WITH WNW WINDS AND 850 MB TEMPS IN THE 6C-8C RANGE...MAX
READINGS SHOULD STILL CLIMB INTO THE UPPER 60S TO LOWER 70S FROM NW
TO SE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 422 PM EDT SAT JUL 12 2014
MAIN CONCERNS DURING THIS TIME PERIOD WILL BE RAIN CHANCES MONDAY
AND TUESDAY WITH COOLER THAN NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK.
SUNDAY NIGHT THROUGH TUESDAY...THE MAIN SURFACE LOW WILL BE CENTERED
OVER JAMES BAY AROUND 00Z/14 WHILE THE MAIN UPPER LEVEL
ENERGY/CLOSED LOW WILL REMAIN OVER THE ONTARIO/MANITOBA BORDER. THIS
WILL PLACE THE UPPER PENINUSLA AND MUCH OF THE EASTERN HALF OF THE
COUNTRY IN BROAD UPPER LEVEL TROUGHING. THE BREAK IN PRECIPITATION
WILL CONTINUE SUNDAY NIGHT AS A BRIEF WEDGE OF DRY AIR PUSHES
THROUGH THE CWA. BY LATE SUNDAY NIGHT...DEEPER MOISTURE...ASSOCIATED
WITH THE UPPER LEVEL 500MB LOW IN SOUTHERN CANADA...WILL APPROACH
THE FAR WESTERN U.P. IN ADDITION...A SURFACE TROUGH WILL EXTEND
SOUTHWESTWARD FROM THE PARENT SURFACE LOW INTO NORTHERN MN. THIS
WILL HELP TO KEEP THE BETTER FORCING TO THE NORTHWEST OF THE U.P.
SUNDAY NIGHT. THE SURFACE LOW WILL SHIFT FROM JAMES BAY 12Z/14 TO
CENTRAL QUEBEC BY 18Z/15. THIS WILL ALLOW THE SURFACE TROUGH TO PUSH
ACROSS THE U.P. THROUGH THE DAY MONDAY AND INTO THE LOWER GREAT
LAKES MONDAY NIGHT. AT THE SAME TIME THE UPPER LEVEL 500MB CLOSED
LOW OVER NORTHERN MN WILL SWEEP ACROSS THE U.P. AND REACH THE
QUEBEC/SOUTHERN ONTARIO BORDER BY 18Z/15. AS FAR AS PRECIP
GOES...HAVE KEPT THE TREND OF INCREASING POPS THROUGH THE DAY
MONDAY...DUE LARGELY TO THE CONVERGENCE ALONG THE SURFACE
TROUGH/INCREASED 1000-500MB RH/VORT MAX PRESSING THROUGH THE U.P.
ALONG WITH DIURNAL HEATING.
ONCE THE BETTER FORCING EXITS THE REGION MONDAY
EVENING...PRECIPITATION CHANCES WILL SLOWLY DIMINISH. STILL KEPT
ONGOING CHANCES OF SHOWERS IN THE FORECAST THROUGH TUESDAY AS THE
UPPER LEVEL 500MB AND INCREASED MOISTURE LINGERS ACROSS THE AREA.
THERE ARE SOME DIFFERENCES IN THE MODELS...WITH THE GFS HAS BEEN
MORE PROGRESSIVE WITH THE UPPER LEVEL LOW WHILE THE EC/GEM KEEP THE
UPPER LEVEL LOW OVER THE U.P. THROUGH TUESDAY AFTERNOON BEFORE
EXITING THE CWA BY 00Z/16. THE 12Z RUN OF THE GFS IS COMING INTO
BETTER AGREEMENT WITH THE EC/GEM LENDING MORE SUPPORT TO THESE
SOLUTIONS. TUESDAY WILL LIKELY END UP BEING THE COOLEST DAY OF THE
WEEK WITH THE UPPER LEVEL LOW PASSING THROUGH THE AREA PULLING 850MB
TEMPS DOWN TO AROUND 4 TO 5C. HIGHS WILL STRUGGLE TO GET INTO THE
60S ACROSS MANY AREAS...WHILE NORMAL HIGHS THIS TIME OF YEAR ARE
AROUND 77 DEGREES.
TUESDAY NIGHT THROUGH THE REST OF THE EXTENDED...VERY QUIET WEATHER
EXPECTED THROUGH THIS TIME PERIOD WITH SLOWLY MODERATING
TEMPERATURES THROUGH THE UPCOMING WEEKEND AS UPPER LEVEL RIDGING
BEGINS TO BUILD BACK INTO THE REGION. AT THE SURFACE...BROAD HIGH
PRESSURE WILL BUILD ACROSS THE UPPER GREAT LAKES REGION AND LINGER
THROUGH FRIDAY NIGHT. THE GFS KEEPS THE HIGH POSITIONED OVER THE
AREA THROUGH SATURDAY WHILE THE EC SLIDES THE HIGH
EASTWARD...ALLOWING A SURFACE LOW AND UPPER LEVEL TROUGH ALONG WITH
INCREASED MOISTURE TO PUSH INTO THE FAR WESTERN CWA. WITH MODEL
DIFFERENCES WILL STICK WITH A CONSENSUS OF THE MODELS FOR
SATURDAY..WHICH BRINGS A CHANCE OF SHOWERS TO THE FAR WESTERN U.P.
DURING THE AFTERNOON AND EVENING HOURS SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 104 AM EDT SUN JUL 13 2014
VFR CONDITIONS SHOULD PREVAIL THRU THE FCST PERIOD AT
KIWD/KCMX/KSAW. HOWEVER...SINCE PCPN OCCURRED AT KSAW...IT`S
POSSIBLE FOG AND STRATUS COULD DEVELOP FOR A TIME OVERNIGHT BEFORE
WINDS PICK UP AHEAD OF FAST APPROACHING COLD FRONT. BECAUSE
UNCERTAINTY IS HIGH...MENTION WAS NOT INCLUDED. ALTHOUGH SHRA ALONG
APPROACHING COLD FRONT ARE WEAKENING/DISSIPATING...COLD FRONT MAY
STILL BRING -SHRA AND SOME GUSTY WINDS TO KIWD/KCMX IN THE NEXT
COUPLE OF HRS. OTHERWISE...BEHIND COLD FRONT...GUSTY WINDS ARE
EXPECTED TODAY WITH ALL TERMINALS GUSTING 20-30KT. STRONGEST WINDS
WILL BE AT KCMX WHICH IS MORE EXPOSED WITH A WNW WIND.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 422 PM EDT SAT JUL 12 2014
SOUTHWEST WINDS THIS EVENING WILL SHIFT SHARPLY TO THE WEST LATE
TONIGHT AS A COLD FRONT ARRIVES. THERE MAY BE SOME WIND GUSTS UP
TO 25 KTS AT LEAST BRIEFLY LATE TONIGHT OVER WEST AND NORTH CENTRAL
LK SUPERIOR BEHIND THE FRONT. AREAS OF FOG ARE CURRENTLY OVER LAKE
SUPERIOR WILL DISSIPATE ON SUNDAY IN WAKE OF THE STRONGER FRONT AS
STRONG DRY ADVECTION TAKES OVER. EXPECT NORTHWEST WINDS TO 20 KTS AT
TIMES INTO EARLY THIS WEEK IN WAKE OF THE COLD FRONT AND AS HIGH
PRESSURE BUILDS OVER THE NORTHERN PLAINS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...ROLFSON
MARINE...JLB
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1237 AM EDT SUN JUL 13 2014
LATEST UPDATE...
AVIATION
.MESOSCALE DISCUSSION...
ISSUED AT 1138 PM EDT SAT JUL 12 2014
CONVECTION IS EXPANDING IN COVERAGE AND EVOLVING PRETTY MUCH AS
EXPECTED LATE THIS EVENING. A BAND OF STORMS IS TAKING SHAPE FROM
NEAR HOLLAND...TO KENOSHA WI...AND THEN DOWN THROUGH METRO
CHICAGO. RAP MODEL INDICATES LLJ CONTINUES TO RAMP UP AND REGIONAL VWP
PROFILES AT LOT...IWX...AND DVN INDICATE 40 KNOTS AT 850 MB WITH
THE CORE OF WIND IN THE MIDDLE OF THESE SITES AROUND 45 TO 50
KNOTS.
INSTABILITY IS THE GREATEST NEAR CHICAGO WITH AROUND 3000 J/KG OF
MU CAPE WITH A DECENT GRADIENT TRENDING DOWN TO THE NORTH AND
EAST. 1000 J/KG IS NOW COMING INTO THE SW CORNER OF THE CWFA. THE
LLJ WILL CONTINUE TO MOVE ENE INTO THE AREA AS THE WAVE NEAR
CHICAGO MOVES E. THE RAP MODEL CONTINUES TO INDICATE THAT
1000-1500 J/KG OF CAPE WILL GET TO I-94 WITH LESSER AMOUNTS TO THE
NORTH BEFORE IT TAILS OFF LATER TONIGHT AS THE LLJ SHIFTS EAST OF
THE AREA.
50 KNOTS OF EFFECTIVE SHEAR IS IN PLACE NEAR CHICAGO AND IS
HELPING THE ORGANIZATION OF THE STORMS. 30-40 KNOTS OF 0-1KM SHEAR
SUPPORTS THE CONTINUED THINKING OF A POSSIBLE TORNADO NEAR THE
WARM FRONT WHICH LOOKS TO BE FROM CHICAGO TO GARY TO SW OF FORT
WAYNE. THIS IS COMING TO FRUITION WITH SOME INDICATIONS OF
ROTATION IN WI/IL AND OVER LAKE MICHIGAN. LOW LCL/S OF 500-750 M ALSO
WOULD HELP SUPPORT A POSSIBLE TORNADO.
&&
.SYNOPSIS...
ISSUED AT 231 PM EDT SAT JUL 12 2014
A COLD FRONT WILL PUSH THROUGH THE REGION LATE TONIGHT INTO SUNDAY
MORNING. THIS SYSTEM WILL TRIGGER THUNDERSTORMS. SOME OF THE
STORMS WILL CONTAIN HEAVY RAIN AND A FEW COULD TURN SEVERE. A
DRIER AIRMASS WILL FILTER IN FROM THE NORTHWEST ON SUNDAY. A COOL
CANADIAN AIRMASS ARRIVES FOR EARLY NEXT WEEK.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 231 PM EDT SAT JUL 12 2014
CHALLENGE IN THE SHORT TERM DEALS WITH THE SEVERE POTENTIAL
TONIGHT. LOOKS LIKE AN INCREASED POTENTIAL FOR SEVERE WEATHER WILL
EXIST.
THE FORCING FROM AN APPROACHING MID LEVEL WAVE COMBINES WITH THE
INSTABILITY AND A LOW LEVEL JET TO TRIGGER THUNDERSTORMS TONIGHT.
GOOD DIFFLUENCE WAS NOTED AT THE TROP. THE MAIN TIMEFRAME LOOKS
TO BE 03Z TO 08Z. DAMAGING WINDS SEEMS LIKE THE MAIN THREAT WITH A
50 KNOT LOW LEVEL JET. GIVEN THE HIGH 0 TO 1 KM SHEAR...LOW LCL
AND LOW LEVEL CAPE...WOULD NOT RULE OUT A TORNADO AS WELL. THIS
RISK SEEMS HIGHEST AROUND INTERSTATE 94 GIVEN THE FORECASTED LOW
LEVEL JET LOCATION. HAZARDS WERE UPDATED IN THE HWO AND SOCIAL
MEDIA POSTS. HIGH POPS ALL ZONES. BY 09Z NORTHWEST COUNTIES SHOULD
SEE A DIMINISHING TREND TO THE PRECIPITATION.
FORECAST SOUNDINGS FOR SUNDAY AFTERNOON INTO SUNDAY NIGHT SHOULD A
LIMITED RISK FOR PRECIPITATION. WITH MOST LOCATIONS TO REMAIN
DRY...I LOWERED POPS.
THE UPPER LOW PIVOTS THROUGH THE REGION ON MONDAY. THIS WILL ACT
TO KEEP IT COOL WITH A RISK FOR A THUNDERSTORM...ESPECIALLY IN THE
AFTERNOON.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 231 PM EDT SAT JUL 12 2014
THE LONG TERM PERIOD WILL SEE A STEADY MODERATING TREND AS THE DEEP
UPPER TROUGH MOVES SLOWLY EASTWARD. VERY COLD H5 TEMPS NEAR -19C
WILL RESULT IN UNSTABLE CONDITIONS. THIS TIME OF YEAR THAT USUALLY
MEANS PM STORMS WITH SMALL HAIL. TRENDED CLOUD COVER UPWARD DURING
THE AFTERNOON TUESDAY OVER INLAND AREAS. INCLUDED A THUNDER MENTION
TUESDAY AFTERNOON AND WEDNESDAY AFTERNOON. BY THURSDAY THE UPPER LOW
WILL BE EAST OF THE CWA AND THE PCPN THREAT WILL BE GREATLY
DIMINISHED. A VERY CHILLY DAY IS EXPECTED TUESDAY WITH HIGHS IN THE
MID 60S. HOWEVER...BY THE WEEKEND TEMPS WILL BE BACK TO AROUND 80.
THE LAST HALF OF THE PERIOD LOOKS DRY AS SFC HIGH PRESSURE WILL
DEVELOP OVER LOWER MICHIGAN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1237 AM EDT SUN JUL 13 2014
MAIN ISSUE FOR AVIATION INTERESTS WITH THE 06Z FCSTS WILL BE
ONGOING CONVECTION AND RESIDUAL FOG/STRATUS THROUGH SUN MORNING.
THE MAIN AREA OF CONVECTION WILL MOVE INTO ALL OF THE TERMINALS BY
06Z. HEAVY RAIN AND A MOIST ATMOSPHERE ARE ALMOST SURE TO PRODUCE
IFR CONDITIONS OR WORSE. WE EXPECT THAT SHOWERS AND STORMS WILL
START COMING TO AN END AROUND 08Z AT KMKG AND THEN BY 11-12Z AT
KJXN. WE DO EXPECT FOG/STRATUS TO HANG AROUND AFTER THE END OF THE RAIN.
CONDITIONS WILL THEN GRADUALLY IMPROVE SUN MORNING AS CIGS LIFT
AND ANY FOG DISSIPATES. WE EXPECT THAT MOST SITES SHOULD BECOME
VFR TOWARD 16Z OR SO WITH SOME SCT CUMULUS/STRATOCUMULUS HANGING
AROUND. GUSTY WINDS TO AROUND 20-25 KNOTS WILL DEVELOP IN THE
AFTERNOON...AND THEN END AROUND 00-01Z.
&&
.MARINE...
ISSUED AT 231 PM EDT SAT JUL 12 2014
OVERALL CONDITIONS ARE EXPECTED TO REMAIN BELOW CRITERIA FOR
HEADLINES. CONVECTION COULD LEAD TO BRIEF PERIOD OF STRONGER WINDS
AND HIGHER WAVES.
&&
.HYDROLOGY...
ISSUED AT 231 PM EDT SAT JUL 12 2014
AT THIS TIME NO WATCH FOR FLOODING. THE THOUGHT IS THAT THE STORMS
WILL TRACK STEADILY EAST...ROUGHLY 03Z TO 08Z. MOST LOCATIONS WILL
SEE A STORM THAT LASTS FOR AN HOUR OR PERHAPS TWO. GENERALLY AN
INCH OF RAIN WILL ACCOMPANY THE STORMS...BUT LOCAL AMOUNTS COULD
TOP 2 INCHES. URBAN AND POOR DRAINAGE FLOODING APPEARS TO BE THE
MAIN RISK FROM THESE STORMS. PWAT VALUES OVER 2 INCHES AND GOOD
FORCING SUPPORT MOST LOCATIONS SEEING THESE HEAVY DOWNPOURS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
MESOSCALE...NJJ
SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...93
AVIATION...NJJ
HYDROLOGY...MJS
MARINE...MJS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1135 PM CDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 1055 PM CDT SAT JUL 12 2014
SURFACE FRONT HAD PUSHED SOUTH OF THE FORECAST AREA EARLIER...BUT TSTMS
FINALLY DID DEVELOP MID TO LATE EVENING ALONG ELEVATED PORTION OF
THE FRONT NEAR THE 850 MB LEVEL. HRRR MODEL HAD BEEN DOING A FAIRLY
DECENT JOB HANDLING THAT. STORMS SHOULD PUSH SOUTHEAST OUT OF THE
AREA LATER TONIGHT. ADDED SOME MENTION OF FOG NRN ZONES LATER TONIGHT.
PATCH OF MID CLOUDS DROPPING SWD FROM SOUTH DAKOTA COULD BRING A BIT
OF LIGHT PCPN TO PARTS OF NORTHEAST NEBRASKA TOWARD SUNRISE.
&&
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 247 PM CDT SAT JUL 12 2014
FORECAST CONCERNS IN THE SHORT TERM WILL BE THUNDERSTORM RE-
DEVELOPMENT AND POTENTIAL FOR LOCALLY HEAVY RAIN...SEVERE WEATHER.
THIS MORNING/S OAX SOUNDING HAD 1.71 IN PWAT AND A WARM CLOUD LAYER
OF OVER 10K FT. CLOSED H5 LOW PRESSURE WAS CENTERED OVER MANITOBA
AND EXTENDED INTO THE NORTHERN CONUS WITH THE STRONG SHORTWAVE
OVER WISCONSIN/SOUTHERN MINNESOTA. H7 MOISTURE OF 6DEG C WAS POOLED
OVER NORTHERN NEBRASKA...BUT WERE 2 TO 3 DEG C LOWER THAN
FORECAST BY THE NAM FRIDAY. WARM H7 TEMPERATURES +10C COVERED MUCH
OF SCENTRAL AND SOUTHERN NEBRASKA. H85 DEWPOINTS WERE ALSO POOLED
IN NORTHERN NEBRASKA WITH 14-16DEG C.
AT MIDDAY...THE BULK OF THE CONVECTION WAS CLOSER TO THE COLD FRONT
OVER SOUTHERN MINNESOTA...ANOTHER BOUNDARY WAS NEAR I80.
IN BETWEEN...IT WAS CLOUDY WITH AREAS OF SPRINKLES/SHOWERS. THIS
AFTERNOON/EVENING...H5 SHORTWAVE TROF ENERGY WILL SWING THROUGH
AND STRENGTHEN FROM IOWA INTO SOUTHERN NEBRASKA...THEN SHIFT
SOUTHWARD OUT OF THE AREA AFTER 09Z. AT 20Z...THE SURFACE FRONT
HAD PUSHED THROUGH MOST OF THE METRO AREA AND WAS NEAR LNK. CAN
SEE THE FRONT ON THE WSR-88D WITH NOT MUCH IN THE WAY OF ECHOES.
SHOULD SEE AN INCREASE IN THE COVERAGE OF STORMS THIS EVENING
WITH THE HEATING AND CONVERGENCE ALONG THE FRONT AND INCREASED
UPPER LEVEL SUPPORT. THE HRRR/RAP DO HAVE SOME ISO TO SCT
CONVECTION...THEN INCREASE COVERAGE ESPECIALLY IN THE 03Z-06Z TIME
PERIOD SOUTH OF THE METRO AREAS IN SOUTHEAST NEBRASKA AND
SOUTHWEST IOWA. HAVE ONLY ISO/SCT COVERAGE IN THE FORECAST THROUGH
03Z...THEN INCREASE TO LIKELY COVERAGE IN SOUTHEAST NEB AND
SOUTHWEST IOWA. THE LOW LEVEL JET SHOULD FOCUS MORE TO OUR
EAST...BUT MAY MENTION LOCALLY HEAVY RAIN FOR A FEW HOURS IN
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA.
SEVERE STORMS CANNOT BE RULED OUT WITH MODERATE INSTABILITY AND
SUFFICIENT SHEAR. SEEMS LIKE HEAVY RAIN WOULD BE MORE OF A
CONCERN DUE TO THE PWATS AVAILABLE AND HIGH EFFICIENCY. H85
CONVERGENCE APPEARS WEAKER IN OUR AREA AND STRONGER FARTHER EAST
INTO IOWA...SO THIS MAY TEMPER SEVERE POTENTIAL. THE STORM
PREDICTION CENTER DOES HAVE OUR AREA IN THE SLIGHT RISK FOR
SEVERE STORMS. THE WPC EXCESSIVE RAINFALL FORECASTS DO MENTION
SOUTHEAST NEBRASKA AND FAR SOUTHWEST IOWA THROUGH
TONIGHT...HOWEVER AFTERNOON UPDATE SHRUNK THE AREA FOR THE
EXCESSIVE RAINFALL THOUGH AND NOW IS JUST CLIPPING OUR AREA.
THE MOISTURE DOES NOT CLEAR OUT CLEANLY AND THERE IS SOME MID
LEVEL WARM AIR ADVECTION WITH CYCLONIC FLOW AROUND THE STORM
SYSTEM TO THE NORTHEAST THROUGH MONDAY. ISOLATED SHOWERS/TSTORMS
WILL BE POSSIBLE SUNDAY THROUGH MONDAY MORNING.
SURFACE HIGH PRESSURE BUILDS IN FOR MONDAY NIGHT AND TUESDAY WITH
NEAR RECORD LOWS MONDAY MORNING AND HIGHS IN THE 70S TUESDAY ABOUT
15 DEGREES BELOW NORMAL.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 247 PM CDT SAT JUL 12 2014
SURFACE HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN TUESDAY
THROUGH SATURDAY. LOOK FOR BELOW NORMAL HIGHS IN THE 70S.
WEDNESDAY AND THURSDAY...THEN HIGHS IN THE 80S FRIDAY AND
SATURDAY. WILL KEEP MAINLY DRY AND MAY NEED TO ADD POPS FOR
SATURDAY WITH A FRONT MOVING INTO THE AREA.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1135 PM CDT SAT JUL 12 2014
STORMS SHOULD STAY SOUTH OF THE KLNK TAF SITE EARLY THIS MORNING.
SOME PATCHY FOG IS POSSIBLE TOWARD SUNRISE AT ALL THREE LOCATIONS
OTHERWISE EXPECT GENERALLY VFR CONDITIONS. SOME -SHRA COULD OCCUR
AT KOFK TOWARD MORNING. SHRA OR TSRA POSSIBLE AT ALL THREE SITES
MAINLY BETWEEN MID AFTERNOON AND EARLY EVENING.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...MILLER
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
348 AM EDT SUN JUL 13 2014
.SYNOPSIS...
AN UPPER LEVEL LOW DIGGING INTO THE GREAT LAKES WILL BRING PERIODS
OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS. THE
ASSOCIATED FRONTAL SYSTEM WILL WORK OFFSHORE BY TUESDAY
NIGHT...WITH DRIER WEATHER AND COOLER TEMPERATURES WORKING INTO
CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UNSETTLED PTRN OVER THE NXT FEW DAYS AS STRONG UPR LOW...WITH
S/WV`S PIVOTING ARND IT...DROPS SEWD INTO THE GTLAKES. MDLS TDA
SHOW THE DVLPMNT OF A PRE-FNTL TROF ACRS CNTRL NY AND PA THIS
AFTN...WITH CDFNT MOVG INTO WRN NY.
LOW LVL JET FOCUSES ACRS WRN NY ACRS LAKE ONTARIO INTO THE ST
LAWRENCE WHERE BEST UPR LVL DVRGNC WILL BE LOCATED. BIG QUESTION WILL BE
AMT OF HEATING WE GET TDA. ATTM IT APPEARS THAT SUNSHINE WILL BE
LIMITED WITH ALOT OF CONVECTIVE DEBRIS ACRS THE RGN THIS MRNG. MESO
DATA ACTUALLY SHOWS SFC TEMPS FALLING THIS AFTN ACRS CNTRL NY WITH
PSSG OF A CONVECTIVE LINE. NAM CAPES MAX OUT BETWEEN 500-1000
J/KG. GFS CAPES MUCH LESS GNRLY 250-500. LCL WRF GETS CAPE UP TO
750 J/KG BUT INDICATES A TALL SKINNY CAPE. WIND FIELDS LOOK GOOD
HOWEVER. PRECIPITABLE H20 VALUES APRCHNG 2 INCHES. RUC BRN`S IN
THE SUPERCELL RNG THIS AFTN. FOR NOW...WE WILL INDICATE POTNL FOR
+RA AND GUSTY WINDS WITH TSRA THIS AFTN/EVNG.
ACTIVITY SHUD SLIDE INTO NE PA BY EARLY EVNG...WITH BEST CHCS FOR
SHRA/TSRA PERSISTING ACRS THIS AREA TNGT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
UPR LOW CONTINUE TO DIG INTO THE GTLAKES THIS PD WHILE ASSUMING A
NEUTRAL OR SLIGHTLY NEGATIVELY TILT. MSTR XPCTD TO MOV BACK NWD
AHEAD OF THE NXT S/WV AND SFC FNT LATE MON AND MON NGT. SOME
TIMING DIFFS EMERGE LATE IN THE PD BUT TREND WILL BE FOR IMPRVG
CONDITIONS ACRS THE RGN ON TUE NGT. XCPTN MAY BE ACRS THE POCONOS
AND SRN CATSKILLS WHERE POTNL FOR MDT TO HVY SHRA/TSRA MAY EXIST
AS AS A WAVE OF LOW PRES LIFTS NEWD ALONG THE FNT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
345 AM UPDATE...
ONLY MINOR CHGS TO LONG TERM GRIDS AS MODELS HV FINALLY COME INTO
AGREEMENT WITH FROPA OCCURRING BY WED MRNG. UL TROF WL BE HANGING BACK
TO THE WEST WITH SLGT CHC FOR SHOWERS DRG THE DAY WED. TROF LIFTS
OUT ON THURSDAY WITH SFC HIPRES BUILDING IN. THUS, HV KEPT
THURSDAY DRY BFR MOISTURE BEGINS TO CREEP NWD ON FRIDAY IN THE
FORM OF SLGT CHC THUNDER AS HIPRES SHIFTS OFF THE EAST COAST AND
RETURN FLOW BEGINS TO KICK IN.
TEMPS SIMILAR TO PRIOR FCST WITH TEMPS BLO NORMAL BY THE MIDDLE OF
THE WEEK, HIGHS IN THE M70S AND LOWS IN THE L50 AND POSSIBLY U40S
IN NOTORIOUS CLDR VLY LOCATIONS. TEMPS WL MODERATE INTO NEXT
WEEKEND AS SRLY FLOW WL DRAW WARM AIR BACK TO THE REGION.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
06Z UPDATE...
HIGH BKN-OVC CIRRUS DOMINANT ACROSS TERMINALS THROUGH EARLY
MORNING HOURS. AFTER 12Z THESE CLOUDS LOWER TO MID-DECK BUT STILL
VFR. EXPECT LOW VFR DECK TO DEVELOP BY 16Z AT ALL TERMINALS. AS
SURFACE TROUGH MOVES THROUGH AREA EXPECT -TSRA TO DEVELOP AFTER
17Z AND CONTINUING THROUGH 01Z, DEPENDING ON TERMINAL. STILL TOO
FAR OUT TO GET SPECIFIC WITH REGARD TO LIKELIHOOD OF THUNDER AND
POSSIBLE RESTRICTIONS, THUS HAVE GONE WITH PROB30.
LGT/VRB AT ALL SITES TONIGHT. SSW WINDS AT 10 KTS WITH SOME
HIGHER GUSTS IN THE AFTN.
OUTLOOK...
SUN NIGHT THROUGH TUE NGT...POTENTIAL RESTRICTIONS FROM SHRA/TSRA.
WED/THUR...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
327 AM EDT SUN JUL 13 2014
.SYNOPSIS...
AN UPPER LEVEL LOW DIGGING INTO THE GREAT LAKES WILL BRING PERIODS
OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS. THE
ASSOCIATED FRONTAL SYSTEM WILL WORK OFFSHORE BY TUESDAY
NIGHT...WITH DRIER WEATHER AND COOLER TEMPERATURES WORKING INTO
CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UNSETTLED PTRN OVER THE NXT FEW DAYS AS STRONG UPR LOW...WITH
S/WV`S PIVOTING ARND IT...DROPS SEWD INTO THE GTLAKES. MDLS TDA
SHOW THE DVLPMNT OF A PRE-FNTL TROF ACRS CNTRL NY AND PA THIS
AFTN...WITH CDFNT MOVG INTO WRN NY.
LOW LVL JET FOCUSES ACRS WRN NY ACRS LAKE ONTARIO INTO THE ST
LAWRENCE WHERE BEST UPR LVL DVRGNC WILL BE LOCATED. BIG QUESTION WILL BE
AMT OF HEATING WE GET TDA. ATTM IT APPEARS THAT SUNSHINE WILL BE
LIMITED WITH ALOT OF CONVECTIVE DEBRIS ACRS THE RGN THIS MRNG. MESO
DATA ACTUALLY SHOWS SFC TEMPS FALLING THIS AFTN ACRS CNTRL NY WITH
PSSG OF A CONVECTIVE LINE. NAM CAPES MAX OUT BETWEEN 500-1000
J/KG. GFS CAPES MUCH LESS GNRLY 250-500. LCL WRF GETS CAPE UP TO
750 J/KG BUT INDICATES A TALL SKINNY CAPE. WIND FIELDS LOOK GOOD
HOWEVER. PRECIPITABLE H20 VALUES APRCHNG 2 INCHES. RUC BRN`S IN
THE SUPERCELL RNG THIS AFTN. FOR NOW...WE WILL INDICATE POTNL FOR
+RA AND GUSTY WINDS WITH TSRA THIS AFTN/EVNG.
ACTIVITY SHUD SLIDE INTO NE PA BY EARLY EVNG...WITH BEST CHCS FOR
SHRA/TSRA PERSISTING ACRS THIS AREA TNGT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
UPR LOW CONTINUE TO DIG INTO THE GTLAKES THIS PD WHILE ASSUMING A
NUETRAL OR SLIGHTLY NEGATIVELY TILT. MSTR XPCTD TO MOV BACK NWD
AHEAD OF THE NXT S/WV AND SFC FNT LATE MON AND MON NGT. SOME
TIMING DIFFS EMERGE LATE IN THE PD BUT TREND WILL BE FOR IMPRVG
CONDITIONS ACRS THE RGN ON TUE NGT. XCPTN MAY BE ACRS THE POCONOS
AND SRN CATSKILLS WHERE POTNL FOR MDT TO HVY SHRA/TSRA MAY EXIST
AS AS A WAVE OF LOW PRES LIFTS NEWD ALONG THE FNT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
NOON UPDATE...
AT THE BEGINNING OF THE LONG TERM FORECAST A COLD FRONT WILL BE
MOVING THROUGH THE AREA WITH SHOWERS ENDING EARLY TUESDAY NIGHT.
BEYOND THAT THE PERIOD WILL BE DOMINATED BY A CUT OFF LOW OVER
THE NORTHERN GREAT LAKES/SOUTHERN ONTARIO, THAT WILL KEEP OUR
WEATHER COOL. HIGHS DURING THE PERIOD WILL MOSTLY BE IN THE 70S,
WITH NIGHTTIME LOWS IN THE 50S (WITH 40S POSSIBLE IN OUR NORMALLY
COLDER SPOTS). BEYOND TUESDAY NIGHT, RAIN CHANCES LOOK LOW. WE
HAVE A SLIGHT CHANCE FOR A SHOWER WEDNESDAY NIGHT INTO EARLY
THURSDAY AS THE MAIN TROF AXIS MOVES THROUGH, AND YET AGAIN FRIDAY
NIGHT/EARLY SATURDAY AS SOME MOISTURE MOVES UP THE COAST. BOTH
CHANCES ARE TOO LOW RIGHT NOW TO INCLUDE ANY MENTION IN THE
FORECAST.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
06Z UPDATE...
HIGH BKN-OVC CIRRUS DOMINANT ACROSS TERMINALS THROUGH EARLY
MORNING HOURS. AFTER 12Z THESE CLOUDS LOWER TO MID-DECK BUT STILL
VFR. EXPECT LOW VFR DECK TO DEVELOP BY 16Z AT ALL TERMINALS. AS
SURFACE TROUGH MOVES THROUGH AREA EXPECT -TSRA TO DEVELOP AFTER
17Z AND CONTINUING THROUGH 01Z, DEPENDING ON TERMINAL. STILL TOO
FAR OUT TO GET SPECIFIC WITH REGARD TO LIKELIHOOD OF THUNDER AND
POSSIBLE RESTRICTIONS, THUS HAVE GONE WITH PROB30.
LGT/VRB AT ALL SITES TONIGHT. SSW WINDS AT 10 KTS WITH SOME
HIGHER GUSTS IN THE AFTN.
OUTLOOK...
SUN NIGHT THROUGH TUE NGT...POTENTIAL RESTRICTIONS FROM SHRA/TSRA.
WED/THUR...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
LONG TERM...HEDEN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1152 PM CDT SAT JUL 12 2014
.UPDATE...
ISSUED AT 1151 PM CDT SAT JUL 12 2014
ONLY A FEW LINGERING SHOWERS OVER THE SOUTHEASTERN
COUNTIES...ADJUSTED POPS DOWNWARD ACCORDINGLY. THERE HAS BEEN SOME
FOG DEVELOPING WITH LANGDON GOING DOWN TO A QUARTER OF A MILE
BRIEFLY ALTHOUGH IT IS NOW BACK UP. HRRR AND SREF SHOW SOME SIGNS
OF FOG...ALTHOUGH WITH NORTHWEST WINDS BRINGING IN DRIER DEWPOINTS
DO NOT THINK IT WILL BE WIDESPREAD. STILL...WITH RECENT RAIN AND
WINDS PRETTY LIGHT IN SOME AREAS...WILL INCLUDE A PATCHY FOG
MENTION IN THE NORTH WHERE RAINFALL AMOUNTS WERE THE HIGHEST.
UPDATE ISSUED AT 1000 PM CDT SAT JUL 12 2014
BUMPED UP WINDS A BIT CLOSER TO WHAT THE HRRR HAS AS WINDS ALONG
THE GUST FRONT AS IT CONTINUES THROUGH OUR SOUTHERN COUNTIES HAVE
BEEN PRETTY STRONG. SHOWERS CONTINUE FROM THE CENTRAL RED RIVER
VALLEY TOWARDS BEMIDJI...AND THE SHORT RANGE MODELS CONTINUE TO
HAVE THE ACTIVITY MOVING SOUTH AND BECOMING WEAKER AND MORE
SCATTERED. ADJUSTED POPS ACCORDINGLY.
UPDATE ISSUED AT 650 PM CDT SAT JUL 12 2014
ADJUSTED POPS FOR LINE OF STORMS MOVING THROUGH THE NORTHERN
COUNTIES. MESOSCALE MODELS PERSIST IN EVENTUALLY BREAKING UP THE
LINE AS IT MOVES SOUTH...A LITTLE LESS SO IN OUR EASTERN COUNTIES.
GIVEN THE WEAKENING INSTABILITY FURTHER SOUTH THIS SEEMS
REASONABLE. KEPT POPS DECREASING THROUGH THIS EVENING BEFORE
EVENTUALLY ENDING AFTER MIDNIGHT. RAIN COOLED AIR HAS ALREADY
DROPPED TEMPS INTO THE 50S ALONG THE NORTHERN TIER...SO LOWERED
TEMPS FOR THE REST OF THE EVENING BUT KEPT LOWS AROUND 50 FOR NOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 310 PM CDT SAT JUL 12 2014
IN THE VERY NEAR TERM THE MAIN FOCUS IS THE SLIGHT RISK OF SEVERE
WEATHER EARLY THIS EVENING. WV SHOWS STRONG DRY PUNCH...SUGGESTIVE
OF JET DEPICTED IN MODELS...PUNCHING RAPIDLY SOUTH. VARIOUS HIGH
RES MODELS SHOW A FAST MOVING LINE OF TSRA ALONG COLD FRONT. MARGINAL
INSTABILITY...0 - 1KM CAPE TO 700 J/KG AND SWI -2C BUT 0 - 6KM
BULK SHEAR CLIMBS TO 60KTS AT 00Z...YET IS POST FRONTAL. BASED ON
THE ATMOSPHERIC PROFILE SUSPECT MAIN THREAT IS DAMAGING WINDS. 15Z
SREF 3HR SVR TSTM PROB SUPPORTS +TSRA 21Z - 03Z.
FRONTAL BOUNDARY ZIPS THROUGH CWFA OVERNIGHT. WINDS SHOULD
DIMINISH AFTER INITIAL PUSH WITH CONVECTION AND LOW LEVEL CAA IS
SPENT. FROM A BOUNDARY LAYER STANDPOINT THE AIRMASS IS ONLY
SLIGHTLY COOLER 12Z SUNDAY THAN 12Z THIS MORNING. SO EXPECT MIN
TEMPS A FEW DEGREES LOWER THAN SATURDAY. STRONGER LOW LEVEL CAA
DEVELOPS DURING THE DAY SO TEMPERATURES WILL BE SLOW TO
RECOVER....HIGHS PERHAPS 10F COOLER. WINDS INCREASE AS WELL WITH
DIRECTION FAVORING A MORE EFFECTIVE MIXING PROFILE. VARIOUS
GUIDANCE SUGGEST A WINDY DAY...PERHAPS CLOSE TO WIND ADV CRITERIA
BY SUNDAY AFTERNOON.
WINDS DIMINISH SUNDAY NIGHT BUT SUSTAINED LOW LEVEL CAA
...ISALLOBARIC COMPONENT AND 30+KTS AT 850 SUGGEST ONLY MODEST
DECREASE.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 310 PM CDT SAT JUL 12 2014
DEEP UPPER LOW HAS BEEN CONSISTENTLY FORECAST TO DROP FROM SOUTHWEST
ONTARIO INTO THE WESTERN GREAT LAKES MONDAY. BEST CHANCE FOR
SHOWERS SHOULD BE CLOSER TO THE DEEP CIRCULATION. WITH COLDER AIR
ALOFT -RASH POSSIBLE WEST OF RRV AS WELL. LACK OF SIGNIFICANT
INSTABILITY WILL NOT INTRODUCE THUNDER...BUT ISOLD -TSRA PSBL DUE
TO STRENGTH OF 700 COLD POOL.
VARIOUS MODELS HAVE CONTINUED TO COME CLOSER TOGETHER PAINTING MONDAY
AS A CHILLY MID JULY DAY. DYNAMIC MODELS TEND TO BE WARMER WHILE THE
MOS/BC/WEIGHTED MODELS COOLER. LOCAL VERIFICATION SUGGESTS THE
DYNAMIC MODELS HAVE BEEN TOO WARM SO WILL LEAN TOWARDS THE
WEIGHTED MOS/BC VERSIONS. LATEST FORECASTS STILL PRESENT
POSSIBILITY OF RECORD OR NEAR RECORD LOW MAXIMUM TEMPERATURES
MONDAY.
QUITE WEATHER FOR TUESDAY AS HIGH SETTLES IN AND GRADIENT RELAXES.
LOW LEVEL THERMAL PROFILE SUGGESTS 2C TO 4C WARMING AND SHOULD BE A
FAIR AMOUNT OF SOLAR...YET LACK OF MIXING KEEPS TEMPERATURE BELOW
MEDIAN.
SURFACE HIGH PRESSURE AND NORTHWEST FLOW ALOFT (WITHOUT MUCH
EVIDENCE OF ANY SHORT WAVE ACTION) SHOULD MEAN MAINLY SUNNY DRY
WEATHER FOR THE WED/THUR TIME FRAME COMING OUT OF OUR UNSEASONABLY
START TO THE WEEK. THE MERCURY WILL STILL BE RECOVERING WEDNESDAY
BEFORE HEADING TO MORE AVERAGE LEVELS THURSDAY AND FRIDAY. GFS (AND
TO A LESSER EXTENT THE ECMWF) IS PAINTING ANOTHER DEEPER LOW SCENARIO
NEAR INTERNATIONAL BORDER BY FRIDAY/SATURDAY...WITH ASSOCIATED
VOLUMINOUS PRECIPITATION AMOUNTS. THIS SEEMS SUSPECT AT THIS TIME
AND HAVE ONLY INCLUDED LOW POPS MAINLY EASTERN FORECAST AREA FOR
NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1151 PM CDT SAT JUL 12 2014
CONDITIONS WILL REMAIN VFR AS THERE COULD BE SOME PATCHY FOG
FORMATION NEAR THE INTERNATIONAL BORDER BUT THAT IT WILL BE PRETTY
ISOLATED AND NOT AFFECT THE TAF SITES. LIGHT NORTHWEST WINDS WILL
PICK UP TO 15 TO 20 KTS WITH GUSTS ABOVE 25 BY MID MORNING
TOMORROW. STRATOCU FORMATION SHOULD BRING SOME CIGS OF AROUND
5000-8000 FT. MORE WIDESPREAD CLOUDS WILL MOVE DOWN WITH ANOTHER
COLD FRONT. SOME SHOWERS ARE POSSIBLE...BUT PRETTY SCATTERED SO
WILL KEEP IT OUT OF THE TAFS FOR NOW. SOME OF THE GUIDENCE HAS
MVFR CIGS LATE IN THE PERIOD BUT THE SREF PROBABILITIES KEEP THE
BEST CHANCES OVER THE FAR NORTHEASTERN PARTS OF THE FORECAST AREA.
FOR NOW KEPT THINGS VFR BUT MAY HAVE TO PUT SOME LOWER CIGS IN AT
KBJI AND KTVF TOWARDS THE END OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...JR
SHORT TERM...EWENS
LONG TERM...WJB
AVIATION...JR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
404 AM EDT SUN JUL 13 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY AND A MUCH STRONGER
COLD FRONT WILL PUSH INTO THE GREAT LAKES ON MONDAY. HIGH PRESSURE
WILL BEGIN TO BUILD IN FOR MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOT A CLEAR CUT FORECAST FOR TODAY. A COLD FRONT WILL BE MOVING
THROUGH TODAY. THE HRRR MODEL SEEMS TO HAVE A GOOD HANDLE ON THE
SITUATION IN QUICKLY MOVING THE FIRST ROUND OF PRECIPITATION THROUGH
BY AROUND 11 AM AND THEN DEVELOPS MORE SHOWERS AND THUNDERSTORMS
FROM NW PA SW THROUGH THE FDY AREA INTO THE AFTERNOON AS THE
AIRMASS DRIES OUT FROM THE NORTH. AT THIS TIME THE FIRST ROUND OF
SHOWERS AND THUNDERSTORMS IS WEAKENING...SOME LOCALLY HEAVY RAIN
IS STILL POSSIBLE. SOME STRONGER WINDS ALOFT SO WATCHING THE
POTENTIAL FOR SOME GUSTY WINDS WITH SOME OF THE THUNDERSTORMS
ESPECIALLY THIS MORNING. THE THREAT OF SEVERE SHOULD BE MAINLY
INLAND FROM LAKE ERIE.
SINCE WE WILL HAVE SOME DRY SPELLS EVEN THOUGH MOST AREAS WILL
REMAIN MOSTLY CLOUDY...EXCEPT ALONG THE LAKESHORE DIDN`T GO COOLER
THAN GUIDANCE..USED A BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SOME SHOWERS AND THUNDERSTORMS WILL BE LINGERING MAINLY OVER THE
SOUTHERN PORTION OF THE FORECAST AREA EARLY IN THE EVENING.
FOR MONDAY AFTERNOON INTO MONDAY NIGHT WENT WITH CHANCE POPS AS
ANOTHER FRONT WILL BE MOVING THROUGH. AT THIS TIME JUST KEPT THEM
CHANCE POPS AS THE AMOUNT OF MOISTURE IS NOT REAL
HIGH...HOWEVER...SOME OF THE MOS GUIDANCE IS INDICATING 60% POPS.
THIS WILL HAVE TO BE WATCHED.
FOR TUESDAY...GUIDANCE POPS ARE SOMEWHAT LOW BUT CONTINUED A
CHANCE OVER NE OH AND NW PA BECAUSE OF INSTABILITY SHOWERS WITH
THE LAKE AND 850 MB TEMPERATURE DIFFERENCE GETTING CLOSE TO 14C.
ALSO INCLUDED A LOW CHANCE OF THUNDER. A SLIGHT CHANCE OF SHOWERS
WILL LINGER IN THE SNOW BELT AREAS THROUGH WEDNESDAY NIGHT.
HOWEVER...ON WEDNESDAY WITH THE UPPER TROF SWINGING THROUGH WILL
HAVE CHANCE POPS OVER MUCH OF THE FORECAST AREA.
TEMPERATURES WILL BE MUCH BELOW NORMAL STARTING TUESDAY. A BIG
DIFFERENCE IN THE GUIDANCE FOR THE LOWS TONIGHT. USED A BLEND WITH
SOME DECREASE IN CLOUDS AND DRY WEATHER...SOME DRYING SHOULD
OCCUR.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
UPPER LEVEL TROUGH WILL LIFT TOWARDS QUEBEC ON THURSDAY AS HIGH
PRESSURE BUILDS OVERHEAD AT THE SURFACE. A LOW CHANCE POP REMAINS
OVER THE HIGHER TERRAIN OF NW PA BUT OTHERWISE EXPECT MOSTLY DRY
CONDITIONS WITH HEIGHTS STARTING TO CLIMB AND THE AIRMASS DRYING
OUT. LOCATIONS DOWNWIND OF LAKE ERIE IN NE OH/NW PA WILL STILL BE
FAIRLY COOL WITH HIGHS NEAR 70 DEGREES WHILE NW/CENTRAL OHIO WILL
START TO RECOVER WITH HIGHS IN THE MID 70S. DRYING TREND CONTINUES
ON FRIDAY WITH HIGHS WARMING ANOTHER 3-4 DEGREES.
BY SATURDAY WE WILL HAVE TO KEEP AN EYE ON A WEAK UPPER TROUGH
LIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS. MOISTURE WILL
ATTEMPT TO SPREAD NORTH AHEAD OF THE TROUGH ACROSS EASTERN OHIO
WHICH COULD LEAD TO AN INCREASED CU FIELD AND MAYBE EVEN A LOW
CHANCE OF SHOWERS. CONFIDENCE IS TOO LOW IN MOISTURE RETURN TO ADD
POPS TO THE FORECAST BUT IT WILL BE SOMETHING TO CONSIDER OVER
FUTURE MODEL RUNS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AT 06Z REGIONAL RADARS SHOWED A COMPLEX OF THUNDERSTORMS EXTENDING
FROM SOUTHERN LOWER MICHIGAN SW TO CHICAGO AND WESTWARD ALONG AN
APPROACHING COLD FRONTAL BOUNDARY. THE MOST INTENSE PORTION OF THIS
THUNDERSTORM COMPLEX IS EXPECTED TO CONTINUE TO MOVE TO THE EAST
NORTHEAST WHILE GRADUALLY SAGGING SOUTH WITH TIME. IT LOOKS LIKE
SHOWERS WILL FILL IN OVERNIGHT BUT THE COVERAGE AND TIMING OF
THUNDERSTORMS REMAINS A CHALLENGE AS WE WAIT TO SEE HOW THE
COMPLEX EVOLVES. TRIED TO TIME A WINDOW OF THUNDERSTORMS INTO MOST
OF THE TAF SITES BUT THIS WILL LIKELY NEED TO BE ADJUSTED.
DEPENDING ON HOW FAST THE PRECIPITATION SAGS SOUTH...STRONG TO
SEVERE THUNDERSTORMS COULD DEVELOP LATER THIS AFTERNOON ON THE
SOUTHERN FLANK OF THE PRECIPITATION AND EFFECT MAINLY
MFD/CAK/YNG. IFR CONDITIONS WILL BE POSSIBLE WITH HEAVY RAIN IN
THUNDERSTORMS. SOUTHWEST WINDS COULD BE BREEZY AT TIMES AHEAD OF
THE FRONT WITH WINDS POSSIBLY SHIFTING TO THE WEST OFF LAKE ERIE
AT CLE/ERI BEHIND THE RAIN.
SKIES WILL START TO CLEAR TOWARDS THE END OF THE TAF CYCLE AND BR/FG
MAY DEVELOP AT LOCATIONS THAT RECEIVE HEAVY RAIN TODAY. DID NOT
INCLUDE IN THE TAFS AT THIS TIME BUT WILL BE SOMETHING TO WATCH FOR.
OUTLOOK...NON VFR POSSIBLE SUNDAY AFTERNOON THROUGH TUESDAY IN
THUNDERSTORMS.
&&
.MARINE...
SOUTHWESTERLY WINDS WILL INCREASE TODAY AS LOW PRESSURE PASSES NORTH
OF LAKE ERIE THIS MORNING...WITH WINDS ON EASTERN LAKE ERIE NEAR 20
KNOTS AT TIMES. THE TROUGH WILL LIFT TOWARDS QUEBEC THIS AFTERNOON
WITH WINDS SHIFTING TO WESTERLY LATER TODAY AND NW THIS EVENING. IT
LOOKS LIKE THE WINDS MAINTAIN ENOUGH OF A SW OFFSHORE COMPONENT THAT
WAVES PEAK IN THE 2 TO 4 FOOT RANGE...JUST BELOW SMALL CRAFT
ADVISORY CRITERIA. WILL HAVE TO KEEP AN EYE ON WINDS AND WAVE
REPORTS...ESPECIALLY IN THE PENNSYLVANIA WATERS...AND MAY STILL NEED
TO ISSUE AN ADVISORY IF CONDITIONS GET CLOSE ENOUGH.
A STRONGER COLD FRONT WILL MOVE ACROSS THE LAKE ON TUESDAY WITH
WINDS ONCE AGAIN INCREASING TO THE 15 TO 20 KNOT RANGE.
SOUTHWESTERLY WINDS WILL SHIFT TO WESTERLY AND WAVES WILL BUILD DOWN
THE LONG FETCH OF THE LAKE. THE COOLER AIRMASS WILL ALLOW FOR BETTER
WAVE GROWTH AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED EAST OF
CLEVELAND WITH WAVES OF 3 TO 5 FEET. WATERSPOUTS MAY ALSO BE
POSSIBLE THROUGH THE MID-WEEK TIME FRAME GIVEN FAVORABLE INSTABILITY
OVER THE LAKE. HIGH PRESSURE WILL BUILD OVERHEAD BY THURSDAY WITH
GOOD MARINE CONDITIONS TO END THE WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
514 AM EDT SUN JUL 13 2014
.SYNOPSIS...
A STRONG UPPER LEVEL TROUGH WILL DROP INTO THE UPPER GREAT LAKES
BY MONDAY. A PAIR OF COLD FRONTS ASSOCIATED WITH THE TROUGH WILL
HANG UP TO THE NORTHWEST OF THE STATE BRIEFLY...BUT EVENTUALLY
PASS THROUGH AND USHER IN COOLER AND DRIER AIR FOR MIDWEEK. THE
COOL CONDITIONS WILL LAST THROUGH LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A TROUGH ALOFT IS PRODUCING A STREGTHENING BAND OF SHOWERS AND
THUNDERSTORMS THAT IS MOVING INTO NORTHWEST PA AT 09Z. THIS
FEATURE IS TIMED TO CROSS THE NORTHWESTERN MOUNTAINS DURING THE
EARLY MORNING. THE SHOWERS WILL START TO PULL FROM SOME LOWER-
DEWPOINT AIR AS IT MOVES INTO THE ALLEGHENIES...AND SHOULD WEAKEN
AND PERHAPS DISSIPATE BY 12Z AS IT TRIES TO GET INTO THE CENTRAL
MTS. THIS FEATURE IS PRACTICALLY IGNORED BY THE RAP AND HRRR.
HOWEVER...MOST MODELS DO DEVELOP HIGH INSTABILITY AND BUILD CAPE
OVER THE ENTIRE AREA LATER THIS MORNING.
IF THE CLOUD DEBRIS AND COOLING EFFECTS THEREOF ARE NOT TOO
SIGNIFICANT TODAY...THE CAPES THIS AFTN COULD TOP 1500 JOULES. THE
SPC HAS ALMOST THE ENTIRE AREA IN THE SLIGHT RISK AREA TODAY INTO
TONIGHT. THE MAIN FORCING FROM THE MCC TO OUR NW ROLLS THROUGH
RIGHT DURING PEAK HEATING AS WELL. WILL ADD SOME ENHANCED WORDING
TO THE WX GRIDS AT THIS POINT...BUT NOT MENTION SEVERE OUTSIDE THE
HWO. RAINFALL COULD BE HEAVY ACROSS THE NRN TIER...BUT THE SPEED
OF THE CELLS WILL MAKE IT DIFFICULT FOR A SINGLE BURST OF RAIN TO
MAKE ANY FLOODING. MULTIPLE/REPEATED STORMS ARE LIKELY IN THE
NORTHWESTERN HALF OF THE AREA THROUGH THE NEAR TERM...AND THIS MAY
CAUSE LOCAL FLOODING. FFG/S CONTINUE TO BE RATHER HIGH AND SERIOUS
PROBLEMS/FLASH FLOODING IS NOT ANTICIPATED AT THIS TIME. LOCALLY
HEAVY RAIN NEAR LEBANON AND LANCASTER HAS LOWERED FLOOD GUIDANCE
THERE...BUT THE STORMS WILL BE MORE-SCATTERED AROUND THAT LOCAL
AREA TODAY.
THE THICKNESS/PERSISTENCE OF THE CLOUD COVER TODAY WILL BE THE
TRICK TO WHERE TEMPS GO. DUE TO THE CLOUDS AND ANTICIPATED
CONVECTION/RAIN - WILL HANG WITH CONTINUITY AND ADD ABOUT 10F TO
THE CURRENT TEMPS IN THE NW AND ABOUT 15F TO THE CURRENT TEMPS IN
THE SE FOR MAXES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
CONVERGENCE WILL CONCENTRATE FROM JST-UNV-IPT THIS EVENING...AND
ONLY SINK SLOWLY TO THE SOUTH. BUT THIS FIRST SHOT OF COOLER AIR
FROM THE NORTHWEST IS NOT ENOUGH TO DISPLACE THE WARM AIR AND HIGH
MOISTURE SO ADDITIONAL STORMS ARE EXPECTED OVERNIGHT.
REDEVELOPMENT IS ALMOST SURELY IN THE CARDS FOR MONDAY AS CLOUDS
THIN BRIEFLY AND JULY SUN STIRS UP THE BOUNDARY LAYER OVER MOST
OF THE AREA. SLIGHT RISK OUTLOOK FROM SPC IS HELD TO JUST THE S/SE
THIRD OF THE AREA MONDAY. HOWEVER...FEEL THAT STRONG STORMS ARE
POSSIBLE A LITTLE FARTHER TO THE NORTH WITH LOW-LEVEL AMBIENT
MOISTURE STILL HIGH AND OVERALL MOISTURE HIGH WITH PWATS BETWEEN
1.5 AND 2 INCHES. WILL HOLD THE CATG POPS TO THE SE...BUT GO
LIKELY POPS OVER MUCH OF THE REST OF THE AREA ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE GFS AND NAM GUIDANCE IS MUCH QUICKER TO PUSH THE FRONT
THROUGH...WITH THE ECMWF DEEPENING THE UPPER LEVEL TROUGH...THOUGH
THE LATEST RUN HAS OPENED UP THE CLOSED LOW. THE EC DEVELOPS A
COHERENT SFC LOW OVER THE MID MS VALLEY AND MOVES IT TO OUR W/N ON
TUESDAY AS IT DEEPENS TO NEAR 1003MB.
HIGH AMPLITUDE RIDGE/TROUGH PATTERN DEVELOPS ACROSS THE MUCH OF
NORTH AMERICA BEGINNING LATE IN THE WEEKEND...AND CONTINUES
THROUGH THE FIRST HALF OF NEXT WEEK.
THE BRUNT OF THE GREATEST 850-700 MB TEMP ANOMALIES AND
ASSOCIATED BELOW NORMAL 500 MB HEIGHTS WILL BE AIMED AT THE LOWER
OHIO VALLEY AND MID MISS VALLEY TUESDAY AND WEDNESDAY...WITH OUR
REGION RESIDING ON THE ACTIVE/EASTERN SIDE OF THIS SLOW MOVING
FEATURE.
AS ADDITIONAL ENERGY IS DRIVEN SSE INTO THE BACK SIDE OF THE HIGH
AMPLITUDE MIDWEST TROUGH...PROLONGED HIGH PWAT AIR /AND LIFT
BENEATH THE RIGHT ENTRANCE REGION OF AN UPPER JET/ MAY LINGER
ACROSS THE SERN ZONES WITH SCATTERED...MAINLY AFTERNOON TSRA
WEDNESDAY AFTERNOON.
THE PATTERN OVER THE NRN CONUS AND SRN CANADA APPEARS TO DE-
AMPLIFY LATER NEXT WEEK AS THE EASTERN U.S. TROUGH BEGINS TO SHEAR
OUT TO THE NE.
THE DRIEST PERIOD OF THE LONG TERM WILL BE THURSDAY AND
FRIDAY...THOUGH SOME ISOLATED CONVECTION STILL CANT BE RULED OUT
EITHER OF THOSE TWO DAYS.
TEMPS START OUT AOA NORMAL PRECEDING THE CFROPA NEXT SUNDAY...AND
PERHAPS MONDAY ACROSS THE SE ZONES...THEN COOL TO AT LEAST 4-6F
BELOW NORMAL FOR DAYTIME HIGHS TUESDAY THROUGH THURSDAY. TEMPS
WILL LIKELY REBOUND TO NEAR NORMAL LATE NEXT WEEK.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
MAINLY VFR CONDITIONS...CLEAR SKIES AND CALM WINDS...WILL PREVAIL
ACROSS PENNSYLVANIA TONIGHT.
MVFR FOG IS POSSIBLE ACROSS THE CENTRAL VALLEYS AND SUSQUEHANNA
REGION TAF SITES EARLY SUNDAY MORNING. RESIDUAL MOISTURE FROM
RAINFALL SATURDAY EVENING WILL AID IN FOG FORMATION AT KMDT AND
KLNS.
AN APPROACHING WARM FRONT WILL BRING THE CHANCE OF TSRA IMPACTS
TO THE NW MTNS SUNDAY. RA CHANCES AND CLOUD COVER WILL INCREASE
FROM NW TO SE THROUGHOUT THE DAY...BUT SITES WILL REMAIN MAINLY
VFR THROUGH THE TAF PERIOD. BRIEF REDUCTIONS IN VSBY AND CIGS ARE
POSSIBLE TOMORROW AFTERNOON IN THUNDERSTORMS.
OUTLOOK...
SUN...BRIEF THUNDERSTORM IMPACTS POSSIBLE.
SUN NIGHT-MON NIGHT...NUMEROUS SHOWERS/TSRA WITH MAINLY BRIEF
PERIODS OF IFR TO MVFR.
TUES-WED...THUNDERSTORM IMPACTS POSSIBLE...MAINLY IN THE
AFTERNOON.
THU...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...CERU
AVIATION...LAMBERT/COLBERT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
115 AM EDT SUN JUL 13 2014
.SYNOPSIS...
WEAK HIGH PRESSURE WILL LINGER OVER THE WESTERN CAROLINAS AND
NORTHEAST GEORGIA TODAY...BEFORE A FRONT APPROACHES. AN
UNSEASONABLY STRONG COLD FRONT WILL APPROACH THE AREA FROM THE
NORTHWEST ON MONDAY AND CROSS THE REGION TUESDAY. COOLER THAN NORMAL
TEMPERATURES WILL ARRIVE FROM MID TO LATE WEEK BEHIND THE FRONT.
&&
.NEAR TERM /THROUGH TODAY/...
0515 UTC UPDATE...POPS WERE LOWERED PER RADAR TRENDS AND CLOUD
COVER FROM SATELLITE IMAGERY. WINDS WERE UPDATED FORM THE LATEST NAM
AND ADJMAV.
AS OF 10 PM...LATEST RADAR IMAGES INDICATE ONLY A COUPLE OF WEAK
SHOWERS ACROSS THE MTNS AND FOOTHILLS. I WILL UPDATE TO LOWER POPS
TO SCHC. FOG HAS STARTED TO FORM ACROSS THE EXTREME WESTERN NC MTN
VALLEYS...FORECAST APPEARS ON TRACK.
AS OF 740 PM...THE FORECAST TRENDS LOOK GOOD. I WILL UPDATE TO
ADJUST SKY AND TEMPERATURES TO OBSERVATIONS. CONDITIONS LOOK
FAVORABLE FOR MTN VALLEY FOG TONIGHT...A LITTLE LESS COVERAGE AND
DURATION THAN THIS MORNING. KCAE RADAR INDICATES THAT A SEA BREEZE
BOUNDARY WAS TRACKING STEADILY WEST. SOME PATCHY FOG IS POSSIBLE IN
THE WAKE OF THE BOUNDARY...GENERALLY ACROSS THE MIDLANDS.
AS 530 PM...THE CURRENT FORECAST REMAINS IN GREAT SHAPE. SCT
CONVECTION OVER THE MTNS HAS TRENDED WEAKER OVER THE PAST HOUR...BUT
COVERAGE HAS REMAINED NEARLY UNCHANGED. I WILL UPDATE THE FORECAST
TO ALIGN SKY WITH SATELLITE OBSERVATIONS AND TO TWEAK TEMPS.
OTHERWISE...CHANGES TO FORECAST WILL BE MINOR.
AT 245 PM EDT SATURDAY... CURRENT MESOANALYSIS INDICATES CAPES OVER
THE MOUNTAINS ARE AROUND 1500 J/KG AND GENERALLY LESS THAN 1000 J/KG
EAST OF THE MOUNTAINS. RAP FORECAST INTO THE EVENING SHOWS CAPE
PERSISTS FOR A WHILE IN THE FAR WESTERN ZONES... ALIGNED WITH THE
AXIS OF HIGH TERRAIN... BUT CAPE DECREASES SUBSTANTIALLY IN THE
EAST. AS HAS BEEN THE CASE DURING THE PAST COUPLE OF NIGHTS...
ISOLATED CONVECTIVE STORMS MIGHT CONTINUE WELL AFTER SUNSET. VERY
LIGHT WINDS THROUGH A DEEP LAYER COULD RESULT IN SLOWLY MOVING
THUNDERSTORMS AND THE POTENTIAL FOR LOCALLY EXCESSIVE RAINFALL.
OTHERWISE... PRIMARY FEATURE ALOFT AFFECTING OUR WEATHER THROUGH
SUNDAY IS A RIDGE EXTENDING FROM THE WEST COAST ACROSS THE SOUTHERN
STATES TO THE CAROLINAS. AT THE SURFACE... HIGH PRESSURE WITH A VERY
WEAK GRADIENT WILL COVER THE REGION. AS HEIGHTS FALL OVER THE
NORTHERN U.S. ON SUNDAY... THE EASTERN PERIPHERY OF THE UPPER LEVEL
RIDGE WILL WITHDRAW WESTWARD A BIT... BUT THROUGH TOMORROW THE RIDGE
IS GOING TO BE THE PRIMARY PLAYER IN CONTINUING THE CURRENT PERIOD
OF GENERALLY TRANQUIL WEATHER. THE AIR MASS OVER THE WESTERN ZONES
WILL REMAIN FAIRLY MOIST AND MODERATELY UNSTABLE THUS SUPPORTING
SCATTERED SHOWERS AND THUNDERSTORMS WHICH WILL BE MOST NUMEROUS OVER
THE HIGHER TERRAIN. CAPE VALUES EAST OF THE MOUNTAINS ON SUNDAY WILL
BE HELD AT BAY BY A RATHER WARM TEMPERATURE PROFILE. AN ISOLATED
SHOWER OR THUNDERSTORM IS POSSIBLE... BUT CUMULUS AND TOWERING
CUMULUS SHOULD DOMINATE THE SKY IN OUR PIEDMONT ZONES TOMORROW. LOWS
WILL BE AROUND 70 IN THE PIEDMONT AND IN THE 60S IN THE MOUNTAINS.
HIGHS ON SUNDAY WILL BE FAIRLY CLOSE TO NORMAL... PERHAPS A FEW
DEGREES ABOVE NORMAL AT A FEW LOCATIONS. HIGHS WILL BE AROUND 90
EAST OF THE MOUNTAINS AND IN THE LOWER AND MID 80S IN THE MOUNTAIN
VALLEYS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
AS OF 230 PM EDT SATURDAY...THE SHORT RANGE PERIOD INITIALIZES
SUNDAY EVENING WITH A BROAD LONGWAVE UPPER TROF ROTATING ACROSS
SOUTHERN ONTARIO. MEANWHILE...BERMUDA HIGH WILL CONTINUE TO ADVECT
WARM/MOIST AIR ACROSS THE SOUTHEAST...NORTHWARD INTO THE MID
ATLANTIC STATES. EXPECTING ONGOING CONVECTION ACROSS THE HIGH
TERRAIN AT FORECAST INITIALIZATION DUE TO IMPROVED INSTABILITY AXIS
AND WEAK SOUTHERLY UPSLOPE FLOW. CHANCE LEVEL POPS WILL BE
FEATURED INITIALLY ACROSS THE HIGH TERRAIN BEFORE TAPERING DOWN TO
SLIGHT CHANCE LEVELS BY DAYBREAK. BY MONDAY MORNING...THE
FIRST...AND WEAKER OF TWO COLD FRONTAL BOUNDARIES WILL APPROACH THE
REGION FROM THE WEST. ADJACENT WEAK UPPER IMPULSE COMBINED WITH
BOUNDARY INTRUSION WILL SPAWN CONVECTION ACROSS THE
MOUNTAINS/FOOTHILLS DURING THE AFTERNOON HOURS ON MONDAY. DUE TO
THE SUSTAINED SOUTHERLY FLOW IN DAYS PAST...THE ATMOSPHERE WILL HAVE
RECOVERED ENOUGH TO YIELD A MODERATELY UNSTABLE WARM SECTOR AHEAD OF
THIS FRONT. THUS...EXPECTING SHOWERS AND THUNDERSTORMS TO SPILL OUT
OF THE HIGH TERRAIN AND PROPAGATE EAST INTO THE PIEDMONT/FOOTHILLS
MONDAY EVENING. AS SAID ABOVE...SUBSTANTIAL CAPE WILL BE PRESENT TO
SUPPORT SOME DEEPER UPDRAFTS LEADING TO A FEW STRONG/SEVERE
THUNDERSTORMS MONDAY AFTERNOON/EVENING...DESPITE WEAKER YET
IMPROVING SHEAR. FORECAST WILL FEATURE LIKELY POPS ACROSS THE
MAJORITY OF THE MOUNTAIN/FOOTHILLS ZONES WHILE LOWER CHANCE POPS ARE
HIGHLIGHTED SOUTH EASTWARD ACROSS NORTHEAST GA AND THE NC/SC
PIEDMONTS.
TUESDAY MORNING THE ABOVE MENTIONED BOUNDARY WILL HAVE ESSENTIALLY
DISSIPATED AND BECOME STATIONARY ACROSS CENTRAL NC...SOUTHWARD
INTO THE MIDLANDS OF SC. AT THE SAME TIME THE RATHER
DEEP/IMPRESSIVE UPPER LOW WILL ROTATE DOWN ACROSS THE GREAT LAKES
WHILE SURFACE CYCLOGENESIS OCCURS ALONG THE EASTERN SEABOARD. THE
STRONG COLD FRONT WILL BE PUSHING THROUGH THE OHIO VALLEY BY EARLY
MORNING...EASTWARD INTO THE CENTRAL/SOUTHERN APPS BY MID/LATE
MORNING...THEN FINALLY FURTHER EAST INTO THE PIEDMONT REGIONS ON
TUESDAY AFTERNOON/EVENING. EXPECTING THE ABOVE MENTIONED SURFACE
CYCLONE TO DEEPEN SLIGHTLY AND AID IN DEVELOPMENT OF A LEE SIDE
TROF ACROSS THE PIEDMONT/COASTAL PLAINS OF NC LATE IN THE
AFTERNOON. THIS WEAK/DIFFUSE BOUNDARY COULD PROVIDE A FOCUS FOR
SURFACE CONVERGENCE AHEAD OF THE APPROACHING/STRONG COLD FRONT.
THERE WILL BE SUFFICIENT UPPER SUPPORT...SHEAR...AND BUOYANCY IN
PLACE TO SUPPORT ORGANIZED STRONG/SEVERE CONVECTION ACROSS THE
ENTIRE REGION ON TUESDAY. THE FORECAST WILL FEATURE WIDESPREAD
LIKELY POPS FOR TUESDAY ENCOMPASSING THE ENTIRE REGION. WILL
CONTINUE WITH SEVERE THUNDERSTORM POSSIBLE WORDING IN THE HWO FOR
BOTH MONDAY EVENING/OVERNIGHT...AND THROUGH THE DAY ON TUESDAY.
TEMPERATURES WILL BE ABOVE NORMAL ON MONDAY AS DEEP SOUTHERLY FLOW
PREVAILS AMONGST PARTLY CLOUDY SKIES WHILE MOSTLY CLOUDY SKIES
COMBINE WITH PRECIPITATION TO KEEP HIGHS A FEW DEGREES BELOW NORMAL
FOR TUESDAY. BY WEDNESDAY MORNING...THE FRONT WILL BE EXITING TO
THE EAST ALLOWING FOR POPS TO TREND DOWN...ALONG WITH TEMPS. LOWS
ON WEDNESDAY MORNING WILL REMAIN AT OR JUST BELOW NORMAL ACROSS THE
LOWER TERRAIN WHERE THE FROPA OCCURS LATER...WHILE THE HIGH TERRAIN
WILL SEE LOWS ON THE ORDER OF 5 DEGREES BELOW NORMAL.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 130 PM SAT...A BROAD TROUGH WILL BE IN PLACE ACROSS THE ERN
TWO THIRDS OF THE CONUS ON WED AS A DEEP LOW PRESSURE SYSTEM SPINS
OVER ERN CANADA AND THE NRN GREAT LAKES. DEEP LAYER DRYING IS
EXPECTED ON WEDNESDAY BEHIND THE SLOWLY DEPARTING/STALLING COLD
FRONT...WITH MAINLY NW FLOW ACROSS THE REGION. WEAK SFC HIGH PRES
WILL BUILD OVER FROM THE N...AND MAX TEMPS SHOULD DIP TO TWO
CATEGORIES BELOW NORMAL BY WED AFTN. AS THE WEAK HIGH SETTLES INTO
PLACE TO OUR N...LOW LEVEL EASTERLY FLOW COULD DEVELOP INTO THE SRN
APPALACHIANS BY THU. IT IS QUESTIONABLE HOW MUCH MOISTURE WILL
RETURN TO THE PROFILES...BUT SLIGHTLY IMPROVED BL RH COULD HELP
TRIGGER ISOLD TO SCT AFTN SHOWERS...ESPECIALLY IN AND NEAR THE MTNS.
MAX TEMPS LOOK TO BE A SOLID 5 TO 10 DEGREES BELOW NORMAL THU
AFTN...POSSIBLY MORE IF WE CLOUD UP QUICKER.
THOUGH SUBTLE MODEL DIFFERENCES EXIST BY LATE WEEK...THERE IS
REASONABLE CONSENSUS REGARDING SHORTWAVE ENERGY DIVING THROUGH THE
SRN PLAINS INTO THE BROAD TROUGH ON THU...AND THEN MOVING TO THE
BASE OF THE SRN APPALACHIANS BY FRI. THIS MAY BRING A WEAK SFC
REFLECTION AND ADDITIONAL MOISTURE BACK TO THE REGION...INTERACTING
WITH THE WEAK SFC HIGH TO THE NORTH AND POSSIBLY PROVIDING SOME
DEGREE OF COLD AIR DAMMING FRI INTO SAT. WILL KEEP MAXES WELL BELOW
NORMAL DURING THIS PERIOD...WITH MAINLY CHC POPS...HIGHEST NEAR THE
BLUE RIDGE.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
AT KCLT...VFR. SW WINDS WILL PERSIST...BECOMING GUSTY DURING THE
DAY. WINDS WILL STAY UP A BIT AFTER SUNSET AS THE PRESSURE GRADIENT
STARTS TO TIGHTEN AHEAD OF AN APPROACHING COLD FRONT. CONVECTIVE
CHANCES ARE QUITE LOW DUE TO WARM AIR ALOFT WHICH WILL LIMIT LIFT.
GUIDANCE DOES NOT FAVOR CIG OR VSBY RESTRICITONS...ALTHOUGH MODEL
TIME HEIGHTS DO SHOW SOME LOW LEVEL MOISTURE AROUND DAYBREAK.
KAVL...MODEL GUIDANCE FAVORS DAYBREAK RESTRICTIONS...AND PERSISTENCE
FROM YESTERDAY WILL BE USED. EXPECT LIFR TO VLIFR VSBY AND CIG
BEFORE DAWN...RETURNING TO VFR BY MID MORNING. SSW WINDS WILL BECOME
GUSTY DURING THE DAY...AND MAY STAY UP A BIT AFTER SUNSET AS THE
PRESSURE GRADIENT TIGHTENS AHEAD OF AN APPROACHING COLD FRONT.
ALTHOUGH CONVECTIVE CHANCES WILL BE GREATEST IN THE MOUNTAINS...THE
CHANCE AT KAVL WILL BE TOO LOW TO MENTION.
ELSEWHERE...VFR. SW WINDS WILL PERSIST...BECOMING GUSTY DURING THE
DAY...AND NOT DIMINSIHING AS MUCH AFTER SUNSET AS THE PRESSURE
GRADIENT TIGHTENS WITH THE APPROACH OF A COLD FRONT. CONVECTIVE
CHANCES WILL BE LIMITED BY WARM AIR ALOFT.
OUTLOOK...RESTRICTIONS IN THUNDERSTORMS ARE POSSIBLE MONDAY AND
TUESDAY. VFR WILL RETURN ON WEDNESDAY BEHIND A COLD FRONT.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 69% MED 74% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 94% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...HG
NEAR TERM...JAT/LGL/NED
SHORT TERM...CDG
LONG TERM...HG
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
316 AM CDT SUN JUL 13 2014
.DISCUSSION...
LATEST SURFACE OBS SHOW VERY WARM AND HUMID CONDITIONS IN PLACE
THIS MORNING WITH CURRENT TEMPS IN THE 70S AND DEWPOINTS IN THE
UPPER 60S TO AROUND 70. THIS DEEPER MOISTURE...AS SHOWN ON 00Z OHX
SOUNDING WITH A PWAT OF 1.7 INCHES...ALON WITH CONVECTIVE
TEMPERATURES IN THE MID 80S PLATEAU TO LOWER 90S ELSEWHERE SHOULD
ALLOW FOR ISOLATED SHOWERS AND THUNDERSTORMS TO DEVELOP TODAY.
MOST LIKELY AREAS TO SEE ANY CONVECTION WILL BE THE PLATEAU AND
NORTHERN ZONES AS HRRR SUGGESTS...BUT CANNOT RULE OUT ACTIVITY
ANYWHERE. DESPITE POSSIBLE PRECIP...STILL EXPECTING ANOTHER HOT
DAY AREAWIDE AS UPPER RIDGE REMAINS ENTRENCHED OVER THE SOUTHERN
CONUS...WITH HIGHS SIMILAR TO YESTERDAY IN THE UPPER 80S TO MID
90S.
CHANGES IN OUR WEATHER PATTERN BEGIN TONIGHT AS AN UNUSUALLY
STRONG TROUGH FOR MID JULY DIGS SOUTHWARD INTO THE EASTERN
CONUS...FORCING AN ALMOST FALL-LIKE COLD FRONT DOWN INTO THE OHIO
VALLEY. MODELS SUGGEST CONVECTION WILL CONTINUE/REDEVELOP ACROSS
THE MIDWEST TODAY THEN MOVE SOUTHWARD SUNDAY NIGHT...POSSIBLY
REACHING OUR NORTHERN ZONES BY SUNRISE MONDAY MORNING. WILL KEEP
MENTION OF LOW POPS TONIGHT FOR THIS POTENTIAL. AS FRONT EDGES
CLOSER ON MONDAY...SCATTERED TO POSSIBLY NUMEROUS SHOWERS AND
STORMS WILL DEVELOP SOUTHWARD THROUGH THE MID STATE FROM MONDAY
INTO MONDAY NIGHT...WARRANTING LIKELY POPS. SPC CONTINUES TO
HIGHLIGHT THE ENTIRE STATE IN A SLIGHT RISK FOR MONDAY/MONDAY
NIGHT...BUT POTENTIAL IMPACTS OF MORNING CONVECTION ALONG WITH
SOMEWHAT LACKLUSTER 00Z FORECAST SOUNDINGS LOOK TO KEEP SEVERE
POTENTIAL ISOLATED ATTM. MAIN THREATS AS IS TYPICAL FOR THIS TIME
OF YEAR WOULD BE GUSTY WINDS AND LOCALLY HEAVY RAINFALL.
COLD FRONT TO PUSH THROUGH THE CWA MONDAY NIGHT INTO
TUESDAY...FORCING PRECIP OUT OF THE AREA BY TUESDAY AFTERNOON.
SPECTACULAR WEATHER IS THEN ANTICIPATED FROM TUESDAY NIGHT THROUGH
THURSDAY AS A COOL AND DRY CANADIAN AIRMASS FILTERS INTO THE
REGION...WITH HIGHS ONLY IN THE UPPER 70S TO LOW 80S AND LOWS IN
THE 50S TO AROUND 60. DESPITE THESE UNUSUALLY COOL TEMPS...RECORD
LOWS IN THE LOW TO MID 50S DO NOT APPEAR IN JEOPARDY ATTM. 00Z
GFS/ECMWF IN EXCELLENT AGREEMENT ON UPPER PATTERN TAKING SHAPE
FORM THURSDAY INTO THE WEEKEND...WITH A POWERFUL UPPER RIDGE
SETTING UP OVER THE FOUR CORNERS AND A DEEP TROUGH REMAINING OVER
THE EASTERN CONUS. THIS PATTERN WILL KEEP THE MID STATE IN NEAR TO
EVEN BELOW NORMAL TEMPS THROUGH THE EXTENDED...WHILE SHORTWAVES
EMBEDDED WITHIN THE TROUGH BRING OCCASIONAL SHOWERS AND
STORMS...WITH NEXT CHANCE FOR RAIN THURSDAY NIGHT THROUGH
SATURDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 95 73 90 69 / 20 30 60 60
CLARKSVILLE 94 71 88 66 / 20 30 60 60
CROSSVILLE 88 68 85 67 / 20 20 60 60
COLUMBIA 95 72 90 70 / 20 20 60 60
LAWRENCEBURG 95 71 90 70 / 20 20 60 60
WAVERLY 95 71 88 66 / 20 30 60 60
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1159 PM CDT SAT JUL 12 2014
.UPDATE...
UPDATED FOR 06Z AVIATION SECTION BELOW.
&&
.PREV DISCUSSION... /ISSUED 641 PM CDT SAT JUL 12 2014...CORRECTED/
UPDATED...
UPDATED FOR ADDING RAIN CHANCES ACROSS THE WEST THROUGH EARLY
EVENING.
DISCUSSION...
A FEW POP UP THUNDERSHOWERS HAVE DEVELOP OVER NORTHEAST ARKANSAS
AND THE BOOTHEEL OF MISSOURI IN THE HIGH CENTER OVER THE PAST
HOUR. THIS ACTIVITY IS LIKELY TO CONTINUE INTO THE 7-9PM TIME
FRAME WITH THE LINGERING SOLAR HEATING. ALSO AS A RESULT CLOUD
COVER HAS INCREASED IN THIS REGION. HAVE ADJUSTED THE EVENING
FORECAST ACCORDINGLY.
JAB
PREV DISCUSSION... /ISSUED 632 PM CDT SAT JUL 12 2014/
UPDATE...
UPDATED FOR 00Z AVIATION DISCUSSION BELOW.
PREV DISCUSSION... /ISSUED 326 PM CDT SAT JUL 12 2014/
DISCUSSION...
TONIGHT INTO TUESDAY...
VERY ISOLATED SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE
FORECAST AREA...95 PERCENT OF THE FORECAST WILL SEE NOTHING FROM
THESE...BUT AS THEY ARE DEVELOPING ON RADAR HAVE ADDED PRE-FIRST
PERIOD ISOLATED STORMS TO THE GRIDS. HRRR 3KM MODEL SHOWED THESE
STARTING TO DEVELOP AROUND 20Z...AND THEY DID...MAYBE I SHOULD
"LISTEN" TO THESE NEW HI-RES MODELS AFTER ALL...THOUGHT THE
DRY AIR ALOFT WITH THE RIDGING AND THE CAPPING SEEN ON THE
FORECAST SOUNDINGS ABOVE 700MB WOULD KEEP STORMS FROM
OCCURRING...BUT NOT TODAY AS I GUESS IT WAS OVERCOME WITH THE CAPES
PUSHING 3.5 TO 4.5K J/KG. PRECIP ENDS SHORTLY AFTER SUNSET WITH THE
LOSS OF HEATING AND CLOUDS WILL MOSTLY DISSIPATE WITH CLEAR TO
MOSTLY CLEAR SKIES.
MODELS STILL SHOWING THE WARMER TEMPS FOR TOMORROW WITH DEWPTS
AROUND THE LOWER 70S...PUSHING APPARENT TEMPS INTO THE 100-104
RANGE...OR JUST BELOW THE HEAT ADVISORY CRITERIA...HOTTEST DAY OF
THE YEAR POSSIBLY AND SHOULD BE DRY. THINGS BEGIN TO CHANGE AS WE
MOVE INTO MONDAY...EARLY DURING THE DAY THE DEEP TROUGH WILL START
TO PUSH SOUTH DIGGING INTO THE MIDDLE MS VALLEY...PRE FRONTAL
TROUGH PRECIP POSSIBLE ON MONDAY...SOME CHANCES FOR STRONG TO
SEVERE STORMS MONDAY AFTERNOON AND EVENING...ALL DEPENDING ON
CLOUD COVER AND IF ATMOSPHERE GETS WORKED OVER SOME OR NOT ABLE TO
FULLY DESTABILIZE TO CREATE VERY STRONG STORMS...SOMETHING TO
WATCH. CAPES EXCEED 2 TO 3K J/KG AND MODEST SHEAR...NOTHING OVERLY
EXCITING...BUT POSSIBLE STRONG TO SEVERE. DEEP TROUGH AXIS PUSHES
THROUGH OVERNIGHT MONDAY AND DRIVES THE COLD FRONT INTO NORTHERN
MS BY MID AFTN TUESDAY...BEST CHANCES FOR PRECIP EXISTS MONDAY
NIGHT THROUGH MIDDAY TUESDAY FOR MUCH...IF NOT ALL OF THE AREA.
DECREASING THROUGH THE AFTERNOON AND EVENING FROM NORTH TO SOUTH
AND THE BOUNDARY SAGS. NOT THINKING MUCH CHANCE FOR SEVERE STORMS
ON TUESDAY...BUT SOME MODELS DO SHOW DECENT CAPE STILL IN
PLACE...BUT UPPER LEVEL SUPPORT IS ALMOST NIL WITH UPPER LEVEL LOW
IN QUEBEC.
WEDNESDAY INTO NEXT WEEKEND...
MODELS SHOW DRYING ON WEDNESDAY WITH DECENT NORTHERLY FLOW PUSHING
MUCH COOLER AIR INTO THE REGION...HIGHS NEAR 80 TO THE LOWER
80S...NEARLY 10-15 DEGREES BELOW NORMAL. NORTHERLY FLOW CONTINUES
INTO THURSDAY WITH COOLER THAN NORMAL AND LIKELY DRY CONDITIONS.
MODELS DIVERGE SOME AS WE APPROACH THE WEEKEND...SOME STARTING TO
SHOW AN UPPER LEVEL FEATURE MOVE ACROSS THE REGION FRIDAY INTO
SATURDAY AND CREATING SHOWERS AND THUNDERSTORMS. HAVE LOW POPS IN
AS LITTLE CONSISTENCY SEEN THE LAST TWO DAYS WITH HOW THIS WILL
PLAY OUT WITH THE AMPLIFIED PATTERN OVER THE CONUS BREAKING
DOWN. GFS ENSEMBLE MEAN SHOWS THE REGION WET FRIDAY AND
SATURDAY AND THE EURO ALSO THIS AFTN...AND THAT MAYBE THE LIKELY
TREND TOWARDS A WET FORECAST FOR THOSE DAYS. -ABS
&&
.AVIATION...
06Z TAFS
FEW CHANGES ANTICIPATED FOR THE 06Z TAFS. VFR WILL PREVAIL THROUGH
THE NEXT 24 HOURS...EXCEPT WHERE BRIEF MVFR VSBY FORMS AT MKL/TUP
EARLY THIS MORNING.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
259 AM CDT SUN JUL 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT SUN JUL 13 2014
MAIN SHORT TERM CONCERN IS ON RAIN POTENTIAL TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED STRONG UPPER RIDGING OVER THE WESTERN U.S. INTO WESTERN
CANADA...WHILE AN ANONYMOUSLY DEEP TROUGH OVER MANITOBA AND NORTHERN
ONTARIO WAS SLOWLY SINKING SOUTH. A PROMINENT DRY SLOT AHEAD OF THE
DESCENDING TROUGH HELPED KICKED THE SHOWERS AND STORMS OUT OF THE
FORECAST AREA BY 03Z LAST EVENING. NORTHWEST FLOW OF 20-35 KT FROM
925MB TO 700MB ALSO WAS BRINGING MUCH DRIER AIR INTO THE AREA...
NOTED BY PRECIPITABLE WATER DOWN TO 1 INCH COMPARED TO AS HIGH AS 2
INCHES AT 00Z. SURFACE DEWPOINTS ARE STILL RELATIVELY HIGH...IN THE
LOW 60S...RESULTING MOSTLY FROM MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. THAT TRAPPING HAS LED TO SOME LOW STRATUS AND FOG
DEVELOPMENT OVERNIGHT. ANOTHER SLUG OF EVEN DRIER AIR WAS EVIDENT
OVER NORTH DAKOTA AND NORTHERN MN WITH PRECIPITABLE WATER AT 0.5
INCH...ALONG WITH SURFACE DEWPOINTS IN THE 40S AND 50S. THIS DRIER
AIR WAS LOCATED BEHIND A COLD FRONT STRETCHING FROM NORTHWEST WI
INTO WEST CENTRAL MN. SOME DYING SHOWERS WERE OVER NORTHWEST WI WITH
THIS FRONT...TIED MOSTLY WITH A SHORTWAVE CROSSING WESTERN LAKE
SUPERIOR. OTHERWISE...THE FRONT IS MOSTLY CLOUD FREE. TEMPERATURE
WISE...850MB TEMPS WERE GENERALLY 13-16C FROM NORTH DAKOTA INTO
WISCONSIN AT 00Z. HOWEVER...5C READINGS WERE SEEN LURKING OVER
CENTRAL MANITOBA WITHIN THE DEEP UPPER TROUGH.
MODELS ARE IN GOOD AGREEMENT DROPPING THE COLD FRONT OVER CENTRAL MN
SOUTHEASTWARD THROUGH THE FORECAST AREA THIS MORNING. DAYTIME
HEATING COMBINED WITH THE LINGERING MOISTURE AROUND WILL LIKELY LEAD
TO A DECENT AMOUNT OF CUMULUS AHEAD OF THE FRONT. ALTHOUGH THE
DETERMINISTIC NAM/GFS/CANADIAN SUGGEST A DRY FRONTAL PASSAGE...NEW
13.00Z ECMWF AS WELL AS THE 13.05Z HRRR AND 3 OF THE 4 HOPWRF
MEMBERS RUN BY THE MPX OFFICE SUGGEST A BAND OF SHOWERS WILL OCCUR
WITH THE FRONT. DEVELOPMENT TIME OCCURS AROUND 14Z / 9 AM AND SINKS
TO THE SOUTH OUT OF THE AREA BY 19Z / 2 PM. INCLUDED A 20 PERCENT
CHANCE AND ISOLATED SHOWERS FOR THIS SHOWER POTENTIAL. DID NOT PUT
ANY THUNDER WITH IT AS THE CAPE IS ONLY PROGGED AT 100-200 J/KG AND
ALL OF THE CAPE IS BELOW THE FREEZING LEVEL. AS THE FRONT PASSES AND
THE LOWER PRECIPITABLE WATER ADVECTS IN BEHIND IT...EXPECT THE
CUMULUS TO GRADUALLY DISSIPATE ALONG WITH DEWPOINTS DROPPING THROUGH
THE 50S. NORTHWEST WINDS SHOULD BECOME A BIT BREEZY TOO IN THE WAKE
OF THE FRONTAL PASSAGE GIVEN A FAVORABLE DEEPER MIXING ENVIRONMENT.
ATTENTION TONIGHT TURNS TO A POTENT SHORTWAVE WITHIN THE DEEP TROUGH
LOCATED IN NORTHEAST MANITOBA. MODELS DROPS THIS SHORTWAVE OVER THE
NORTHERN HALF OF MN BY 12Z...WITH AN UPPER LOW ALSO INDICATED AT
500MB. DPVA AHEAD OF THIS FEATURE COMBINED WITH THE MOIST AND MUCH
COOLER AIR WITHIN THE TROUGH IS EXPECTED TO SPREAD SHOWERS INTO
NORTHWEST WI BY 12Z MONDAY. BELIEVE THESE SHOULD STAY AWAY FROM
TAYLOR COUNTY BEFORE 12Z. SOME CLOUD INCREASE IS LIKELY NORTH OF I-
90 AFTER MIDNIGHT...THOUGH. A SECONDARY COLD FRONTAL PASSAGE SHOULD
COME INTO AND POSSIBLY THROUGH THE AREA BY 12Z AS WELL. ADVECTION
BEHIND THIS FRONT WILL ALLOW TEMPERATURES TO DIP INTO THE 50S...WITH
EVEN A FEW UPPER 40S POSSIBLE IN CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 259 AM CDT SUN JUL 13 2014
THE MAIN ISSUE HERE IN THE LONG TERM IS WITH THE TRACK OF THE UPPER
LOW IN NORTHERN MN AT 12Z MONDAY. THE ECMWF HAS BEEN PERSISTENT AS A
SLOWER...MORE AMPLIFIED SOLUTION...TAKING THE UPPER LOW ACROSS
CENTRAL AND NORTHERN WI MONDAY EVENING AND ACROSS LOWER MICHIGAN ON
TUESDAY. HOWEVER...THE 13.00Z CANADIAN/NAM/GFS ALL ARE IN STEP WITH
EACH OTHER SHOWING A TRACK ACROSS UPPER MICHIGAN ON MONDAY...AND
INTO EAST CENTRAL ONTARIO ON TUESDAY. THESE DIFFERENCES ARE
SIGNIFICANT AS IT IMPACTS THE LOCATION OF DPVA AND DIURNALLY
ENHANCED SHOWER POTENTIAL...ALONG WITH HOW COLD TEMPERATURES WILL BE
MONDAY AND TUESDAY. IT SHOULD BE NOTED THAT THE 13.00Z ECMWF HAS
TRENDED JUST SLIGHTLY TOWARDS THE CANADIAN/NAM/GFS. TO HANDLE THE
DIFFERENCE BETWEEN THESE TWO SOLUTIONS...HAVE DECIDED TO STAY PRETTY
CLOSE TO THE PREVIOUS FORECAST...WHICH WOULD BE IN-LINE WITH A MODEL
CONSENSUS IDEA.
FOR MONDAY...WE SHOULD GRADUALLY SEE SHOWER COVERAGE INCREASE
THROUGH THE DAY AS THE UPPER LOW AND ASSOCIATED COLD AIR ALOFT
APPROACH. THE MOST NUMEROUS COVERAGE IS ANTICIPATED NORTH OF HIGHWAY
29 CLOSER TO THE UPPER LOW. THESE SHOWERS SHOULD MOSTLY DIMINISH
MONDAY NIGHT DUE TO THE LOSS OF DAYTIME HEATING. TUESDAYS RAIN
CHANCES ARE A BIT MORE QUESTIONABLE NOW AFTER SEEING THE 13.00Z
ECMWF. THE FLOW IS STILL CYCLONIC INTO THE REGION...BUT DRY AIR IS
ADVECTING IN AT THE SAME TIME. THE CANADIAN/GFS/NAM ARE ALL
DRY...AND NOW THE ECMWF ONLY HAS SOME LIGHT QPF BETWEEN 12-18Z
TUESDAY BEFORE DRYING OUT. HAVE THEREFORE TRENDED PRECIPITATION
CHANCES LOWER A BIT AND DRIED OUT LOCATIONS WEST OF THE MISSISSIPPI
RIVER. REGARDING TEMPERATURES...850MB TEMPS PLUMMET TO 4-6C IN THE
MORNING WHICH WILL KEEP HIGHS MOSTLY IN THE 60S. THE LONE EXCEPTION
TO THAT IS IN FAR SOUTHWEST WI WHERE THE COLDER AIR ENTERS LAST AND
HAS MORE SUN POTENTIAL IN THE MORNING. WITH LESS SHOWER POTENTIAL ON
TUESDAY...HAVE RAISED HIGHS SLIGHTLY BUT THEY ARE STILL A FAR CRY
FROM NORMAL.
BENIGN WEATHER CONTINUES TO BE THE RULE AFTER TUESDAY. UPPER
TROUGHING DOMINATES MUCH OF THE EASTERN U.S. WEDNESDAY INTO THURSDAY
WITH THE FORECAST AREA ON THE BACK SIDE OF THE TROUGH. THIS FAVORS
SUBSIDENCE ALOFT AND DRYING HIGH PRESSURE AT THE SURFACE. THE GFS
CONTINUES TO SPLATTER LIGHT QPF AROUND DURING THE AFTERNOON AND
EVENINGS AS A RESULT OF TOO MUCH EVAPOTRANSPIRATION. AS WE HEAD INTO
FRIDAY AND SATURDAY...500MB HEIGHTS LOOK TO RISE ACROSS MUCH OF THE
EASTERN U.S. AS THE TROUGH LIFTS OUT. IN FACT...WE COULD EVEN BE
UNDER UPPER RIDGING BY SATURDAY AS A SHORTWAVE TROUGH SLIDES ACROSS
THE NORTHERN ROCKIES. THIS PATTERN HEADING INTO SATURDAY FAVORS A
CONTINUATION OF DRY CONDITIONS ALONG WITH A NICE WARMING TREND
TOWARDS CLOSER TO NORMAL. MUCH OF THE MORE HUMID AIR LOOKS TO BE
STUCK ACROSS THE SOUTHERN U.S. THANKS TO THE COLD/DRY AIR FROM
EARLIER THIS WEEK DROPPING ALL THE WAY DOWN TO THE GULF COAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1145 PM CDT SAT JUL 12 2014
SATELLITE AND SURFACE OBSERVATION INDICATE THE CLOUDS HAVE CLEARED
OUT AND WITH THE MOISTURE FROM THE RAIN...SOME FOG IS STARTING TO
FORM. IT APPEARS THE SURFACE HAS DECOUPLED AND THE STRONGER WINDS
SHOWN IN THE VWP WINDS FROM SURROUNDING RADARS AND IN THE 13.00Z
NAM AND 13.01Z RAP SOUNDINGS MAY NOT INHIBIT THE FOG. HAVE PUT
MORE FOG INTO BOTH TAF SITES WITH THE POSSIBILITY OF BOTH SITES
GOING DOWN TO IFR CONDITIONS OVERNIGHT. THE FOG SHOULD LIFT EARLY
SUNDAY MORNING AS A SECONDARY COLD FRONT COMES THROUGH SWINGING
THE WINDS AROUND TO THE NORTHWEST WITH THE SPEEDS INCREASING TO
AROUND 10 KNOTS. ALSO EXPECTING THIS FRONT TO BE ACCOMPANIED BY A
BAND OF CLOUDS THAT COULD BRING A SHORT PERIOD OF MVFR CEILINGS.
ONCE THE CLOUDS CLEAR OUT BEHIND THE FRONT...THE MIXING BECOMES
DEEP ENOUGH FOR GUSTS TO AROUND 20 KNOTS AT BOTH AIRPORTS. THE
WINDS WILL THEN DIE DOWN EARLY SUNDAY EVENING AS THE LOW LEVEL
INVERSION DEVELOPS AND CUTS OFF THE MIXING.
&&
.CLIMATE...
ISSUED AT 259 AM CDT SUN JUL 13 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE MONDAY AND TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI RIVER
VALLEY.
FOR LA CROSSE...
MONDAY....FORECAST HIGH 68. RECORD 65 IN 1994
TUESDAY...FORECAST HIGH 70. RECORD 68 IN 1962
FOR ROCHESTER...
MONDAY....FORECAST HIGH 64. RECORD 64 IN 1952
TUESDAY...FORECAST HIGH 67. RECORD 67 IN 1962
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04
CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1145 PM CDT SAT JUL 12 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 309 PM CDT SAT JUL 12 2014
MAIN FORECAST CONCERNS ARE ON SEVERE THUNDERSTORM POTENTIAL OVER
NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. HOWEVER...THE SEVERE
POTENTIAL APPEARS TO BE DECREASING THIS AFTERNOON AS WIDESPREAD
SHOWERS AND ISOLATED THUNDERSTORMS OVERSPREAD THESE AREAS. THE
MAIN CONCERN IS SHIFTING MORE TOWARD A HEAVY RAIN THREAT FOR LATE
THIS AFTERNOON INTO THIS EVENING.
KEEPING A CLOSE EYE ON THUNDERSTORM DEVELOPMENT ALONG A COLD FRONT
AND UPPER LEVEL DISTURBANCE THIS AFTERNOON. MESOSCALE MODELS
CONTINUE TO FIRE STORMS OVER THESE AREAS LATE THIS AFTERNOON AND
THEN THEY PUSH THIS ACTIVITY TO THE EAST DURING THE EVENING HOURS.
HOWEVER...THE STRONGEST 850 MB MOISTURE TRANSPORT FOCUSED SOUTH AND
EAST OF THE FORECAST AREA. EFFECTIVE BULK SHEAR OF 40 TO 50 KTS AND
MUCAPE VALUES OF 1000-1500 J/KG WOULD SUPPORT SUPERCELL STRUCTURES
OVER NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. ALSO...IF SURFACE
BASED CONVECTION DEVELOPS THERE COULD EVEN BE THE POTENTIAL TO SEE
AN ISOLATED TORNADO. HOWEVER...0-1 KM SHEAR IS VERY WEAK AND WE
WOULD HAVE TO SEE THE SURFACE LOW AND WARM FRONT MAKE IT A LITTLE
FURTHER NORTH TO HAVE TORNADO POTENTIAL. PRECIPITABLE WATER
VALUES AND WARM CLOUD DEPTH CONTINUES TO SUPPORT HEAVY RAINFALL
POTENTIAL...WITH PW VALUES OF 1.5 TO 1.9 AND WARM CLOUD DEPTH OF
3.5 TO 4.0 KM ALONG AND SOUTH OF INTERSTATE 90. THERE IS A
SECONDARY BOUNDARY STRETCHING FROM NORTHWEST WISCONSIN SOUTHWEST
THROUGH THE TWIN CITIES AREA TO THE INTERSTATE 90 CORRIDOR THEN
STRETCHING BACK TO THE WEST. THIS BOUNDARY PUSHES SOUTHEAST VERY
SLOWLY LATE THIS AFTERNOON INTO THIS EVENING AND WE WILL HAVE TO
KEEP AN EYE ON CONVECTION NEAR THIS BOUNDARY. IF IT STALLS THERE
COULD ENOUGH LOCALIZED VORTICITY TO SEE A NON SUPERCELL TORNADO OR
TWO IF SURFACE BASED CONVECTION OCCURS. ALSO...STORMS NEAR THIS
BOUNDARY HAVE BEEN FAIRLY SLOW MOVING AND WOULD HAVE THE POTENTIAL
TO PRODUCE LOCALLY HEAVY RAINFALL. SHOWERS AND THUNDERSTORMS WILL
TAPER OFF AND END THIS EVENING AS A SHORTWAVE TROUGH EXITS THE
REGION.MOSTLY CLOUDY SKIES ARE EXPECTED THROUGH THE EVENING THEN
WE SHOULD SEE A DECREASING CLOUD TREND LATE TONIGHT INTO EARLY
SUNDAY MORNING. PLAN ON OVERNIGHT LOWS IN THE UPPER 50S TO LOWER
60S. A WEAK FRONT WILL SLIDE THROUGH THE AREA TOMORROW BUT WILL
MOSTLY GENERATE SOME CUMULUS ALONG AND SOUTH OF INTERSTATE 90.
FORECAST SOUNDINGS SUGGEST WE COULD BUILD JUST ENOUGH CAPE FOR
AN ISOLATED SHOWER OR THUNDERSTORM SO HAVE ADDED A SLIGHT CHANCE
FOR THIS ACTIVITY DURING THE AFTERNOON HOURS. OTHERWISE...PLAN ON
HIGH TEMPERATURES RANGING FROM THE LOWER 70S OVER NORTH CENTRAL
WISCONSIN TO THE UPPER 70S ACROSS NORTHEAST IOWA.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 309 PM CDT SAT JUL 12 2014
A DEEP TROUGH DIVES INTO THE REGION SUNDAY NIGHT THROUGH MONDAY
BRINING UNSEASONABLY COLD TEMPERATURES AND CHANCES FOR SHOWERS TO
THE REGION. 850 MB TEMPERATURES FALL TO AROUND 4 C MONDAY INTO
TUESDAY...SETTING THE STAGE FOR POTENTIAL RECORD COOL HIGH
TEMPERATURES. SCATTERED SHOWERS ARE EXPECTED ACROSS THE AREA ON
MONDAY. WITH THE SHOWERS/CLOUD COVER...TEMPERATURES WILL BE RATHER
CHILLY FOR THIS TIME OF YEAR WITH HIGHS ONLY MAKING IT INTO THE
UPPER 50S TO POSSIBLY AROUND 60 OVER NORTH CENTRAL WISCONSIN.
ELSEWHERE HIGHS WILL ONLY MAKE IT INTO THE 60S. CANNOT RULE OUT
SLIGHTLY WARMER TEMPERATURES OVER PORTIONS OF NORTHEAST IOWA INTO
FAR SOUTHWEST WISCONSIN WHERE HIGHS COULD APPROACH 70. MUCH OF THE
AREAS WILL BE CLOSE TO SEEING RECORD COOL HIGH TEMPERATURES ON
TUESDAY WITH HIGHS ONLY IN THE 60S. SEE CLIMATE SECTION BELOW FOR
FOR RECORD LOWEST HIGH TEMPERATURES FOR MONDAY AND TUESDAY. THE
TROUGH PULLS EAST OF THE REGION TUESDAY NIGHT INTO WEDNESDAY. WE
SHOULD SEE TEMPERATURES START TO MODERATE WEDNESDAY THROUGH
THURSDAY WITH HIGHS CLIMBING BACK INTO THE 70S. HIGH PRESSURE WILL
PROVIDE DRY AND QUIET WEATHER WEDNESDAY THROUGH FRIDAY. FLOW
ALOFT BECOMES ZONAL FOR NEXT WEEKEND AND WE COULD SEE CHANCES FOR
SHOWERS AND THUNDERSTORMS RETURN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1145 PM CDT SAT JUL 12 2014
SATELLITE AND SURFACE OBSERVATION INDICATE THE CLOUDS HAVE CLEARED
OUT AND WITH THE MOISTURE FROM THE RAIN...SOME FOG IS STARTING TO
FORM. IT APPEARS THE SURFACE HAS DECOUPLED AND THE STRONGER WINDS
SHOWN IN THE VWP WINDS FROM SURROUNDING RADARS AND IN THE 13.00Z
NAM AND 13.01Z RAP SOUNDINGS MAY NOT INHIBIT THE FOG. HAVE PUT
MORE FOG INTO BOTH TAF SITES WITH THE POSSIBILITY OF BOTH SITES
GOING DOWN TO IFR CONDITIONS OVERNIGHT. THE FOG SHOULD LIFT EARLY
SUNDAY MORNING AS A SECONDARY COLD FRONT COMES THROUGH SWINGING
THE WINDS AROUND TO THE NORTHWEST WITH THE SPEEDS INCREASING TO
AROUND 10 KNOTS. ALSO EXPECTING THIS FRONT TO BE ACCOMPANIED BY A
BAND OF CLOUDS THAT COULD BRING A SHORT PERIOD OF MVFR CEILINGS.
ONCE THE CLOUDS CLEAR OUT BEHIND THE FRONT...THE MIXING BECOMES
DEEP ENOUGH FOR GUSTS TO AROUND 20 KNOTS AT BOTH AIRPORTS. THE
WINDS WILL THEN DIE DOWN EARLY SUNDAY EVENING AS THE LOW LEVEL
INVERSION DEVELOPS AND CUTS OFF THE MIXING.
&&
.HYDROLOGY...
ISSUED AT 309 PM CDT SAT JUL 12 2014
A FEW STRONGER THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY
DOWNPOURS WITH RAINFALL RATES OF 1-2 INCHES PER HOUR THIS
AFTERNOON INTO EARLY THIS EVENING. THIS WILL LEAD TO PONDING OF
WATER AND LOCALIZED FLOODING IS POSSIBLE...ESPECIALLY IN URBAN
AREAS.
&&
.CLIMATE...
ISSUED AT 309 PM CDT SAT JUL 12 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE MONDAY AND TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI RIVER
VALLEY.
FOR LA CROSSE...
MONDAY....FORECAST HIGH 69. RECORD 65 IN 1994
TUESDAY...FORECAST HIGH 68. RECORD 68 IN 1962
FOR ROCHESTER...
MONDAY....FORECAST HIGH 64. RECORD 64 IN 1952
TUESDAY...FORECAST HIGH 67. RECORD 67 IN 1962
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
HYDROLOGY...WETENKAMP
CLIMATE...WETENKAMP
AREA FORECAST DISCUSSION
NWS GOODLAND KS
536 AM MDT SUN JUL 13 2014
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN JUL 13 2014
UPPER FLOW WILL BE NORTHWEST FROM TODAY THROUGH TUESDAY NIGHT. A
SURFACE FRONT WILL MOVE SOUTH INTO NORTHWEST KANSAS LATE THIS
AFTERNOON/EARLY THIS EVENING. HIGH PRESSURE WILL MOVE INTO THE
PLAINS SUNDAY NIGHT AND MONDAY AND PERSIST THROUGH TUESDAY NIGHT.
EARLY THIS MORNING LIGHT SHOWERS CONTINUE OVER THE SOUTHWEST CORNER
OF THE FA. THE HRRR INDICATES THAT THESE SHOWERS SHOULD DISSIPATE
BY 14 OR 15Z. PLAN TO INCLUDE SCATTERED SHOWERS IN THE GRIDS AND
ZONES FOR THESE.
FOR TODAY AND TONIGHT A WEAK FRONT APPROACHES THE NORTHERN FA BY
LATE AFTERNOON. THERE IS A WEAK SHORTWAVE IN THE FLOW AS WELL WHICH
SHOULD SUPPORT LOW CHANCES OF STORMS. CHANCE POPS WILL FOLLOW THE
FRONT SOUTH ACROSS THE FA TONIGHT.
THE GFS AND NAM HAVE DIFFERENCES WITH THE AMOUNT OF FORCING FOR
MONDAY/MONDAY NIGHT. THE NAM DOES NOT INDICATE ANY FORCING UNTIL
AFTER 06Z TUESDAY. THE GFS SHOWS VERY WEAK FORCING FOR MONDAY WITH
A LACK OF FORCING MONDAY NIGHT. AS A RESULT, CONFIDENCE IS LOW SO
WILL KEEP POPS LOW. THE BEST CHANCE OF THUNDERSTORMS WILL BE OVER
EASTERN COLORADO.
TUESDAY/TUESDAY NIGHT GOOD MOISTURE AND FORCING COME TOGETHER OVER
THE FA. INSTABILITY DROPS OFF FOR THIS EVENT SO SHOWERS WITH
ISOLATED THUNDER WILL BE THE PREDOMINANT TYPE OF WEATHER OTHER THAN
TUESDAY AFTERNOON/EVENING IN THE WEST WHERE THERE WILL BE GREATER
INSTABILITY.
MAX TEMPERATURES TODAY AND MONDAY WILL RISE TO THE MID AND UPPER
80S. MUCH COOLER READINGS WILL OCCUR ON TUESDAY WITH MAX
TEMPERATURES AROUND 70. MIN TEMPERATURES WILL COOL TO THE LOWER TO
MID 60S TONIGHT. MIN TEMPERATURES MONDAY AND TUESDAY NIGHTS WILL BE
IN THE MID AND UPPER 50S.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 220 AM MDT SUN JUL 13 2014
WEDNESDAY...AN UPPER LEVEL SHORTWAVE TROUGH WILL SHIFT ACROSS THE
HIGH PLAINS REGION WEDNESDAY...WHICH LOOKS TO BE THE LAST BIT OF
ENERGY ASSOCIATED WITH THE MAIN UPPER LEVEL LOW CENTER OVER THE
EASTERN THIRD OF THE CONUS. THE POSITION OF THE SURFACE HIGH
PRESSURE SYSTEM ON WEDNESDAY WILL FUNNEL LOTS OF MOISTURE INTO THE
AREA...WITH ALL GUIDANCE SUGGESTING AT LEAST SOME CHANCES FOR
PRECIPITATION ACROSS MUCH OF THE AREA. INSTABILITY ALOFT SHOULD
REMAIN OVER EASTERN COLORADO...BUT CANNOT RULE OUT SOME ISOLATED
THUNDERSHOWERS OVER THE REST OF THE AREA WEDNESDAY. DUE TO CLOUD
COVER...RAINFALL AND ALREADY COOLER CANADIAN AIR...HIGH TEMPERATURES
WILL BE 15 TO 20 DEGREES BELOW NORMAL IN THE UPPER 60S TO LOWER
70S...WITH SOME GUIDANCE SUGGESTING TEMPERATURES COULD BE EVEN A BIT
LOWER.
THURSDAY/FRIDAY...A SHORTWAVE RIDGE WILL BEGIN MOVING OVER THE
FORECAST AREA FOR THURSDAY AND FRIDAY. SOME LINGERING CHANCES FOR
THUNDERSHOWERS WILL REMAIN FOR THE REGION ON THURSDAY AS THE SURFACE
CONVERGENCE ZONE SHIFTS SOUTHWARD WITH THE EXITING HIGH PRESSURE
SYSTEM TO THE EAST. WINDS WILL SHIFT AND BRING IN MORE DRY AIR ALOFT
ON FRIDAY...WHICH SHOULD KEEP CONDITIONS DRY FOR MOST OF THE AREA.
CHANCES FOR AFTERNOON THUNDERSTORMS IN EASTERN COLORADO ARE POSSIBLE
ALONG SURFACE TROUGH AND COULD BE SUSTAINABLE WITH PLENTY OF
INSTABILITY. TEMPERATURES WILL BEGIN TO REBOUND THURSDAY IN THE
UPPER 70S TO LOWER 80S...AND THE RETURN OF WARM AIR ADVECTION WILL
BRING TEMPERATURES BACK TO NEAR NORMAL ON FRIDAY.
SATURDAY...THE NEXT UPPER LEVEL TROUGH LOOKS TO BEGIN TO MOVE INTO
THE PACIFIC NORTHWEST ON SATURDAY...WHICH COULD BE THE NEXT WEATHER
MAKER FOR THE REGION NEXT WEEKEND. CHANCES FOR AFTERNOON STORMS WILL
CONTINUE ON SATURDAY AS THE POSSIBILITY OF THE NEXT COLD FRONTAL
PASSAGE WILL AFFECT THE AREA. MODEL TIMING VARIES ON THE PASSAGE TO
EITHER SATURDAY OR SUNDAY...SO CONFIDENCE IS LOW REGARDING PINNING
DOWN PRECIPITATION CHANCES AT THIS TIME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 530 AM MDT SUN JUL 13 2014
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS AT KGLD AND
KMCK. LATER TODAY THERE IS A CHANCE OF THUNDERSTORMS MOVING ACROSS
BOTH SITES FOR A FEW HOURS, SOME MVFR WILL BE POSSIBLE NEAR
STORMS. OTHERWISE CLEARING WILL OCCUR BEHIND THE STORMS FOR THE
REST OF THE NIGHT AND MONDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...MK
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
1111 AM EDT SUN JUL 13 2014
.UPDATE...
ISSUED AT 1110 AM EDT SUN JUL 13 2014
NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED FOR LATEST
OBSERVATIONAL TRENDS. CURRENT THINKING ON THUNDERSTORM DEVELOPMENT IS
CONSISTENT WITH EARLY MORNING FORECAST GRIDS. A COLD FRONT EXTENDING
FROM SE MI TO CENTRAL IL SHOULD SERVE AS FOCUS FOR ORGANIZED
THUNDERSTORM DEVELOPMENT ACROSS OH AND INDIANA THIS AFTERNOON. LATEST
THINKING WHICH IS SUPPORTED BY SHORT RANGE GUIDANCE INCLUDING THE RAP
AND HRRR POINT TOWARDS THIS MOVING INTO THE NORTHERN PART OF THE
FORECAST AREA THIS EVENING. PRIOR TO THIS ISOLATED TO SCATTERED
CONVECTION WILL BE POSSIBLE ACROSS THE AREA...ALTHOUGH LOCALIZED
INSTABILITY OVER THE FAR SE WILL LEAD TO THUNDERSTORM CHANCES THERE
PRIOR TO CHANCES IN THE CENTRAL PART OF THE FORECAST AREA. WILL
CONTINUE TO BRING IN CHANCES TO THE NORTH AND SOUTHEAST PART OF THE
FORECAST AREA BEFORE THE CENTRAL AND SOUTHWEST PARTS OF THE AREA.
UPDATE ISSUED AT 750 AM EDT SUN JUL 13 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON THE RECENT OBSERVATIONS.
OTHERWISE...NO AWOS OR ASOS SITES WERE REPORTING FOG...AS THE MID
CLOUD DECK HAS GENERALLY HINDERED IT FROM DEVELOPING. WITH THAT IN MIND...
FOG WAS REMOVED FROM THE GRIDS TO START THE DAY. OTHERWISE...THE PREVIOUS
FORECAST REMAINS ON TARGET WITH ISOLATED TO SCATTERED CONVECTION ANTICIPATED
TO BEGIN TO DEVELOP AROUND OR SHORTLY AFTER NOON.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 420 AM EDT SUN JUL 13 2014
AN UPPER LEVEL RIDGE WAS CENTERED ACROSS PARTS OF THE SOUTHERN PLAINS
AND EXTENDING EAST INTO THE SOUTHEASTERN STATES...WITH THE RIDGE
EXTENDING INTO THE INTER MOUNTAIN WEST. MEANWHILE TO ITS EAST A
TROUGH EXTENDED SOUTH INTO THE UPPER MS VALLEY REGION AND NORTHERN
GREAT LAKES FROM A RATHER STRONG MID SUMMER UPPER LEVEL LOW CENTERED
OVER NORTHWEST ONTARIO. ONE MID LEVEL SHORTWAVE IS WORKING ACROSS THE
OH VALLEY REGION AT THIS TIME...WITH ANOTHER WORKING ACROSS THE GREAT
LAKES REGION. THIS COMBINATION IS PUSHING A RATHER SHEARED OUT EAST
TO WEST COLD FRONT INTO THE SOUTHERN GREAT LAKES TO MID MS VALLEY
REGION...WITH THE FRONT ALSO APPROACHING THE LOWER OH VALLEY REGION.
MID AND HIGH CLOUDS CONTINUE TO WORK GRADUALLY EAST SOUTHEAST ACROSS
MUCH OF THE AREA. PARTS OF THE SOUTHERN CWA NEAR THE KY/VA/TN TRI
STATE AREA HAVE EXPERIENCED THE LEAST AMOUNT OF CLOUDS AND
TEMPERATURES...ESPECIALLY IN VALLEYS HAVE BEEN SLIGHTLY COLDER IN
THESE LOCATIONS. SO FAR THIS MORNING...NO ASOS OR AWOS SITES HAVE
REPORTED ANY FOG. HOWEVER...NEAR ZERO DEWPOINT DEPRESSIONS IN SOME
VALLEY LOCATIONS SUGGEST THAT AT LEAST SOME LIGHT RIVER VALLEY FOG IS
PROBABLY OCCURRING.
THE SHORTWAVE GENERALLY PASSING BY TO THE NORTH OVER THE NEXT FEW
HOURS WILL SERVE TO FURTHER SHEAR OUT THE COLD FRONT FROM EAST TO
WEST WITH IT STALLING OUT AND WASHING OUT OR MERGING WITH A MORE
SUBSTANTIAL COLD FRONT THAT SHOULD APPROACH THE OH VALLEY LATE IN THE
PERIOD. THIS SECOND COLD FRONT WILL BE PUSHED SOUTHEAST AS THE UPPER
LEVEL FLOW DROPS SOUTH INTO THE GREAT LAKES REGION ON MONDAY...WITH
THE OVERALL PATTERN AMPLIFYING. THIS UPPER LOW AND THE ASSOCIATED
SHORTWAVES TO ROTATE THROUGH THE DEVELOPING TROUGH SHOULD LEAD TO AN
INCREASE IN FORCING LATE TONIGHT AND ON MONDAY. RETURN LOW AND
MOISTURE FLUX AHEAD OF THIS BOUNDARY IS LEADING TO A SUBSTANTIAL
INCREASE IN MOISTURE AT THE LOW LEVELS AND ALOFT. THIS INCREASE IN
MOISTURE WILL CONTINUE WITH PW EXPECTED TO GRADUALLY CLIMB TO CLIMB TO
ABOUT 1.75 INCHES BY LATE AFTERNOON OR EARLY EVENING...WITH SLIGHTLY
HIGHER VALUES ANTICIPATED ACROSS THE FAR NORTHWEST. MODEL FORECAST
SHOW SOME FLUCTUATIONS IN PW VALUES DUE TO DIFFERENT TIMING OF
CONVECTION AND SHORTWAVES. THE GFS SHOWS THE MOST VARIABILITY OF PW
FROM TONIGHT INTO MONDAY. MEANWHILE THE NAM HAS THE HIGHEST VALUES ON
AVERAGE.
CONVECTION WILL BE POSSIBLE AT ANY TIME FROM MIDDAY TODAY THROUGH THE
END OF THE PERIOD. MODEL GUIDANCE CONTINUES TO SHOW THE POTENTIAL FOR
CONVECTION TO DEVELOP ACROSS THE HIGHER TERRAIN NEAR THE VA/TN/KY TRI
STATE AREA FIRST AND THEN ACROSS THE NORTHERN PART OF THE CWA CLOSER
TO THE BOUNDARY AND PASSING SHORTWAVES. GREATER INSTABILITY AND A BIT
STRONGER SHEAR LATER THIS AFTERNOON AND EVENING SHOULD BE REALIZED
ACROSS THE NORTHWEST COUNTIES. MODELS DEVELOP SOME MODERATE INSTABILITY
ACROSS THAT AREA...A FEW STRONG TO POSSIBLY A SEVERE THUNDERSTORM OR
TWO MAY OCCUR. CONVECTION BY THIS EVENING OR TONIGHT ALSO MIGHT TRAIN
WEST TO EAST ACROSS PARTS OF THE AREA...ESPECIALLY NORTHWEST WITH THE
STEERING FLOW BECOMING NEARLY PARALLEL TO THE STALLING BOUNDARY. WITH
THE PW NEAR OR ABOVE THE 75TH PERCENTILE LOCALLY HEAVY RAIN MAY BE
PRIMARY THREAT ACROSS THE NORTH FROM LATE THIS AFTERNOON INTO
TONIGHT. RECENT DAYS HAVE BEEN DRY AND MANY LOCATIONS HAVE BELOW
NORMAL RAINFALL OVER THE PAST 4 TO 6 WEEKS...SO IT WOULD TAKE AN
INITIAL SHOT OR TWO OF HEAVY RAIN FOLLOWED BY ADDITIONAL HEAVY RAIN
SHORTLY THEREAFTER TO PRIME ANY LOCATION.
ON MONDAY...THE GREATER INSTABILITY SHOULD RESIDE FURTHER SOUTHEAST
OF THE STALLED BOUNDARY AND THE APPROACHING FRONT. THIS COMBINED WITH
FORCING FROM HEIGHT FALLS...SHOULD AGAIN LEAD TO ROUNDS OF SHOWERS
AND THUNDERSTORMS. IF PARTS OF THE REGION CLEAR OUT FOR A FEW HOURS...
A PREFRONTAL MULTICELL CLUSTER OR LINE OR TWO OF STORMS COULD BECOME
STRONG TO SEVERE AS MODERATE INSTABILITY IS FORECAST BY THE MODELS
ACROSS THE SOUTH. STRONG WIND GUSTS AND LOCALLY HEAVY RAIN WOULD
AGAIN APPEAR TO BE THE MAIN THREATS FROM THE STORMS. AGAIN...DEPENDING
ON THE EVENTUAL MAGNITUDE AND EXTENT OF INSTABILITY SOME LOCALLY
HEAVY RAIN MIGHT BE A GREATER CONCERN THAN THE SEVERE THREAT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 AM EDT SUN JUL 13 2014
THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT. THE
LARGE SCALE WEATHER PATTERN FEATURES A DEEP TROUGH OF LOW PRESSURE
IN THE UPPER ATMOSPHERE MOVING EAST OUT OF THE GREAT LAKES REGION
AND INTO NEW ENGLAND MONDAY NIGHT THROUGH TUESDAY NIGHT. THE WEATHER
MAKE WITH THIS SYSTEM FOR EASTERN KENTUCKY WILL BE A POTENT SURFACE
COLD FRONT. THIS FRONT LOOKS TO BE ORIENTED FROM WEST TO EAST
AND...IF THE MODELS BE TRUE...WILL MOVE SLOWLY ACROSS CENTRAL AND
EASTERN KENTUCKY MONDAY NIGHT AND TUESDAY. NUMEROUS SHOWERS AND
STORMS ARE EXPECTED TO BREAK OUT ALONG THE BOUNDARY IN THE WARM AND
HUMID AIR MASS THAT WILL BE IN PLACE. SOME OF THE STORMS MONDAY
EVENING COULD BE STRONG TO SEVERE WITH DAMAGING WINDS AND LOCALLY
HEAVY RAINFALL BEING THE PRIMARY THREATS. ONCE THE COLD FRONT MOVES
OUT OF THE AREA TUESDAY NIGHT...A LARGE RIDGE OF CANADIAN HIGH
PRESSURE WILL USHER COOLER AND DRIER AIR INTO THE AREA THROUGH THE
END OF THE WEEK. THE MODELS DIVERGE A BIT WITH THEIR SOLUTIONS FROM
FRIDAY NIGHT ONWARD...SO THAT PORTION OF THE FORECAST WILL BE LOWER
CONFIDENCE. THAT BEING SAID...INCORPORATED THE POSSIBILITY OF
ISOLATED SHOWERS AND STORMS FOR FRIDAY ONWARD DUE TO MODEL
UNCERTAINTY. TEMPERATURES TO BEGIN THE PERIOD WILL BE QUITE
UNSEASONABLE...WITH HIGHS ONLY MAKING IT INTO THE MID TO UPPER 70S
FROM TUESDAY THROUGH THURSDAY. THE AIR MASS WILL MODIFY SLIGHTLY TO
END THE WEEK AND INTO THE WEEKEND...AS HIGHS ARE EXPECTED TO WARM TO
AROUND 80 FROM FRIDAY ONWARD. OVERNIGHT LOWS WILL BE MOSTLY IN THE
LOW TO MID 60S...WITH COOLER LOWS OF THE MID TO UPPER 50S TUESDAY
NIGHT AND WEDNESDAY NIGHT AS THE NEW AIR MASS SETTLES OVER THE
REGION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 750 AM EDT SUN JUL 13 2014
PREDOMINANTLY VFR IS EXPECTED TO CONTINUE FOR MUCH OF THE PERIOD.
WINDS WILL GENERALLY BE LIGHT AS WELL ALTHOUGH DURING PEAK HEATING...
ALTHOUGH DURING PEAK HEATING WINDS MAY BECOME A BIT GUSTY AND SUSTAINED
AS HIGH AS 10KT OUT OF THE SOUTHWEST AS A COLD FRONT DROPS INTO THE
OH VALLEY INCREASES THE PRESS GRADIENT. THE EXCEPTION DURING THE
FIRST 12 HOURS TO VFR WILL BE IN ANY SHOWERS AND THUNDERSTORMS
POPPING UP AROUND 16Z AND AFTER...WHERE LOCALIZED RESTRICTIONS TO
MVFR OR IFR CIGS/VSBY ARE POSSIBLE. MORE ORGANIZED SHRA AND TSRA
SOUTHEAST ACROSS THE AREA FROM 22Z THROUGH THE END OF THE PERIOD.
AGAIN LOCALIZED RESTRICTIONS ARE POSSIBLE WITH THIS. AS FOR NOW...
WE HAVE CONTINUED TO GO WITH VCTS AT ALL FOUR TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...JP
LONG TERM...AR
AVIATION...JP
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1050 AM EDT SUN JUL 13 2014
.SYNOPSIS...
BERMUDA HIGH WILL KEEP SOUTHERLY FLOW ACROSS THE MID-ATLANTIC
THROUGH MONDAY. A COLD FRONT WILL CROSS THE AREA TUESDAY. HIGH
PRESSURE WILL BUILD ALONG THE EASTERN SEABOARD FOR THE SECOND HALF
OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 14Z...MID-LEVEL CLOUDS OVER ABOUT HALF THE CWA WITH THE
BALT-WASH CORRIDOR FAIRLY CLEAR. COLD FRONT IS OVER MIDWEST TO ERN
GREAT LAKES PER RADAR MOSAIC. THE COLD FRONT WILL APPROACH FROM
THE WEST...ENTERING THE AREA TONIGHT. HOT AND MOIST SFC...BUT
POOR LAPSE RATES AND WEAK SHEAR WILL LIMIT THE STORM THREAT TODAY.
SHOULD SEE ONLY ISOLATED AFTERNOON CONVECTIVE THUNDERSTORM
DEVELOPMENT IN THE CWA. FOCUS OF PRECIP IS AHEAD OF THE
APPROACHING FRONT FROM THE WEST. AGREE WITH MORNING HRRR RUNS THAT
DEPICT JUST THIS.
MAX TEMPS TODAY AROUND 90F...LOW 90S SOUTH/SW OF DC METRO.
PRECIP COVERAGE INCREASES THIS EVENING AS THE COLD FRONT
APPROACHES FROM THE WEST. PWATS WILL HAVE INCREASED TO NEAR 2
INCHES BY THEN AND FORCING FROM ONGOING ACTIVITY ALLOWS FOR LIKELY
POPS IN THE NWRN ZONES. FLOW IS WEST OR WSW TONIGHT...SO ACTIVITY
SHOULD BREAK UP/DISSIPATE SOMEWHAT AS IT PROGRESSES EAST. STILL
SHOULD BE A SOMEWHAT ACTIVE NIGHT WITH HEAVY RAIN AND DAMAGING
WIND AS THE MAIN THREATS.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
MID-ATLANTIC WILL CONTINUE TO RESIDE IN A WARM SECTOR MONDAY THROUGH
MONDAY NIGHT AS A COLD FRONT GRADUALLY WORKS SOUTHEASTWARD...LIKELY
RESIDING JUST NORTHWEST OF THE CWA LATE MONDAY NIGHT.
IT IS UNCLEAR WHERE THERE WILL BE AN EARLY MORNING LULL IN
CONVECTION OR IF THERE COULD BE ONGOING CONVECTION ACROSS THE
NORTHWEST PORTION OF THE CWA. WHETHER THIS IS THE CASE OR
NOT...MONDAY AFTERNOON HAS THE POTENTIAL TO BE ACTIVE AS SREFS
INDICATES SUFFICIENT CAPE AND SHEAR BY AFTERNOON TO SUPPORT THE
POTENTIAL FOR SEVERE THUNDERSTORMS. WHILE THE PRIMARY THREAT WILL BE
DAMAGING WIND GUSTS...LARGE HAIL AND ISOLATED TORNADOES CAN/T BE
RULED OUT. GIVEN HIGH PRECIPITABLE WATER ENVIRONMENT...A FLASH
FLOODING RISK WIL BE ACROSS THE CWA.
WHILE BOTH THE SEVERE RISK AND CONVECTIVE COVERAGE SHOULD DIMINISH
IN THE EVENING...WILL CONTINUE WITH CHANCE POPS OVERNIGHT GIVEN
MOIST ATMOSPHERE AND COLD FRONT JUST TO THE NORTHWEST OF THE CWA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AT THE START OF TUE...THE CDFNT...WHILE APPROACHING...WL STILL
RESIDE NW OF CWFA. THERE WL BE AN EVER STEEPENING TROF AXIS ALONG
THE I-95 CORRIDOR THAT WL SERVE AS A FOCUSING MECHANISM. SUSPECT
THAT THE TRUE CFP WL BE TOUGH TO DETERMINE AS ENERGY FM THE FNT WL
BE ABSORBED BY THE TROF DURING THE COURSE OF THE DAY. BY MID-LT
AFTN...THAT TRANSITION WL BE COMPLETE.
SUCH A PROGRESSION WL GNLY KEEP THE MOST UNSTBL AIR ACRS THE
TIDEWATER AND DELMARVA. HWVR...PLENTY OF SHEAR WL BE PRESENT...THX
TO THE RRQ OF A 120 KT UPR JETMAX. GIVEN KINEMATICS AND FORCED SFC
CNVGNC/ASCENT...STILL THINK THAT LKLY POPS THE WAY TO GO. SINCE AMS
WL STILL BE VERY MOIST...W/ DEWPTS IN THE UPR 60S OR NEAR 70F AND
PWAT 1.5-2.0 INCHES...ANY TSRA WL BE HVY RAINERS. WHILE THE BEST
COMBO OF INSTBY/LIFT WL BE SE OF AREA...IT/LL STILL BE PSBL TO HV
LCL WET MICROBURSTS OR HAIL SUPPORTING STRONG UPDRAFTS. THEREFORE...
THE SVR WORDING WL REMAIN IN HWO. EVOLUTION OF SVR PROBS WL PARTLY
BE DETERMINED BY CDFNTL PROGRESS AND MAY BE INHIBITED BY DEBRIS
CLDS. MON LOOKS LIKE THE MORE VIOLENT DAY...BUT THERE IS A MARGINAL
RISK TUE AS WELL.
A SHARP H5 TROF AXIS WL FOLLOW TUE NGT-WED. AM NOT QUITE SURE HOW
QUICKLY THE SFC BNDRY WL CLEAR AREA AT FIRST. AM THEREFORE HOLDING
ONTO SOME POPS ALONG THE BAY/SRN MD TUE NGT. HWVR...ONCE THE UPR
AXIS SWEEPS THRU...IT WILL KICK THE FNT TO THE COAST. COOL DRY CNDN AIR
WL STREAM INTO CWFA THEREAFTER. THAT/LL SET UP SVRL ATYPICAL JULY
DAYS.
BY DAYS 6-7 /FRI-SAT/...HIPRES WL MV OFFSHORE...SETTING UP RETURN
FLOW AND PERHAPS AN APPROACHING WMFNT. TSRA CHCS RETURN TO THE FCST
DUE TO THE INHERENT INSTBY/LIFT.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR WITH MID-LEVEL CLOUDS THROUGH THIS AFTERNOON. ONLY ISOLATED
THUNDERSTORMS THIS AFTERNOON. FOR THE REST OF THE DAY...ISOLATED
TSRA EXPECTED TO DEVELOP NEAR A TROUGH THIS AFTERNOON MOVING
EASTWARD THROUGH EARLY EVENING. THIS MAY WARRANT VCTS INCLUSION BY
12Z TAF TIME. IT/S ALSO POSSIBLE THAT THUNDERSTORMS IN
PENNSYLVANIA SLIDE SOUTHEASTWARD BY LATE EVENING...ALTHOUGH
CONFIDENCE IN EXACT EVOLUTION/TIMING IS LOW.
LEE TROUGH AND A MOIST/UNSTABLE ENVIRONMENT WILL LEAD TO MORE
NUMEROUS THUNDERSTORMS FOR MONDAY...PARTICULARLY FOR THE AFTERNOON.
HEAVY RAINFALL/STRONG WINDS WILL BE POSSIBLE IN STORMS.
SCT-NMRS TSRA DURING THE DAY TUE...PERHAPS LINGERING INTO THE EVNG
FOR THE METROS. FLGT RESTRICTIONS XPCTD W/IN STORMS ALTHO SHUD HV
HEALTHY PDS OF VFR AS WELL.
WED-THU...HIPRES BLDS. VFR.
&&
.MARINE...
SOUTHERLY WINDS CONTINUE TO CHANNEL UP THE BAY LATE THIS MORNING
WITH AN SCA NOW INTO MONDAY MORNING. ANY LULL SHOULD BE SHORT
THROUGH THIS AFTERNOON...WITH 20 TO 25 KT GUSTS THIS EVENING.
THUNDERSTORMS THIS EVENING AND AGAIN MONDAY MAY PRODUCE STRONG
WIND GUSTS.
TROF AXIS OVER WATERS TUE MRNG...TO BE JOINED BY CDFNT TUE AFTN-NGT.
SINCE THERE WL BE A BNDRY NEARLY OVERHEAD...GRADIENT FLOW WL BE
LGT-- SLY BCMG WLY. HWVR...THIS SETUP WL PRODUCE NMRS TSRA...EACH WL
CONTAIN A GUSTY WND THREAT AS WELL AS VERY HEAVY RAIN. THUS...SMW/S
XPCTD.
COOLER/DRIER AIR WL SURGE INTO AREA WED AND STAY THRU THU. GDNC NOW
STARTING TO PICK UP ON MIXING POTL IN THE MID BAY WED. WL ADD PSBL
SCA TO SYN/HWO.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS WILL PERSIST AROUND HALF A FOOT ABOVE A FULL MOON
NORMAL THROUGH MONDAY. SIMILAR HIGH TIDE MONDAY MORNING TO THIS
MORNING...WILL APPROACH MINOR THRESHOLDS AT THE MOST SENSITIVE
SITES AGAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR ANZ530-531-539.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ532>534-540-
541-543.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 10 AM EDT
MONDAY FOR ANZ537.
&&
$$
SYNOPSIS...BAJ/HTS
NEAR TERM...BAJ/BPP
SHORT TERM...BPP
LONG TERM...HTS
AVIATION...BAJ/BPP/HTS
MARINE...BAJ/BPP/HTS
TIDES/COASTAL FLOODING...BAJ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1013 AM EDT SUN JUL 13 2014
.SYNOPSIS...
AN UPPER LEVEL LOW DIGGING INTO THE GREAT LAKES WILL BRING PERIODS
OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS. THE
ASSOCIATED FRONTAL SYSTEM WILL WORK OFFSHORE BY TUESDAY
NIGHT...WITH DRIER WEATHER AND COOLER TEMPERATURES WORKING INTO
CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1010 AM UPDATE...LEADING SHORT WAVE MOVING THROUGH WRN NY WITH
RESULTING CONVECTION SPREADING ACROSS THE FINGER LAKES AND CENTRAL
SRN TIER ATTM. SOME OF THE CONVECTION IS PRODUCING GUSTY WINDS AND
BRIEF HEAVY DOWNPOURS. ACTIVITY IS EXPECTED TO HOLD TOGETHER AND
SPREAD ACROSS THE REGION DURING THE LATE MORNING AND AFTERNOON
HOURS. WILL CONTINUE TREND OF INCREASING POPS INTO THE
CATEGORICAL/LIKELY POP RANGE AND HIGH CHC/LOW LIKELY OVER NE PA.
AS FOR SVR WX POTENTIAL THE MID LEVEL FLOW AND LOW LEVEL
SHEAR/HELICITY ARE VERY FAVORABLE FOR SVR WX BUT THE LIMITING
FACTOR IS THE INSTABILITY. LATEST RAP MODEL GUIDANCE INDICATES
CAPE VALUES OF 400-800 J/KG WHICH SEEMS REASONABLE CONSIDERING THE
ABOUT OF CLOUDS ALREADY OVER THE REGION. A PRE-FRONTAL TROF
CURRENTLY BACK IN OHIO IS PROGGED TO CROSS THE REGION THIS
AFTERNOON AND EVENING WHICH MAY FOCUS ACTIVITY AFTER THIS INITIAL
ACTIVITY. SPC LATEST UPDATE KEEPS MUCH OF THE AREA IN SLIGHT RISK,
IF SUNNY PERIODS DEVELOP THIS AFTERNOON IT COULD GET INTERESTING.
BASED ON ENV WINDS AND LACK OF SIGNIFICANT CAPE THE MAIN SVR WX
THREAT WOULD BE DAMAGING WINDS. ALONG WITH THE SVR POTENTIAL
AIRMASS IS REALLY JUICY SO ANY CONVECTION TODAY WITH HAVE HEAVY
DOWNPOURS.
PREVIOUS DISC...
AN UNSETTLED PTRN OVER THE NXT FEW DAYS AS STRONG UPR LOW...WITH
S/WV`S PIVOTING ARND IT...DROPS SEWD INTO THE GTLAKES. MDLS TDA
SHOW THE DVLPMNT OF A PRE-FNTL TROF ACRS CNTRL NY AND PA THIS
AFTN...WITH CDFNT MOVG INTO WRN NY.
LOW LVL JET FOCUSES ACRS WRN NY ACRS LAKE ONTARIO INTO THE ST
LAWRENCE WHERE BEST UPR LVL DVRGNC WILL BE LOCATED. BIG QUESTION WILL BE
AMT OF HEATING WE GET TDA. ATTM IT APPEARS THAT SUNSHINE WILL BE
LIMITED WITH ALOT OF CONVECTIVE DEBRIS ACRS THE RGN THIS MRNG. MESO
DATA ACTUALLY SHOWS SFC TEMPS FALLING THIS AFTN ACRS CNTRL NY WITH
PSSG OF A CONVECTIVE LINE. NAM CAPES MAX OUT BETWEEN 500-1000
J/KG. GFS CAPES MUCH LESS GNRLY 250-500. LCL WRF GETS CAPE UP TO
750 J/KG BUT INDICATES A TALL SKINNY CAPE. WIND FIELDS LOOK GOOD
HOWEVER. PRECIPITABLE H20 VALUES APRCHNG 2 INCHES. RUC BRN`S IN
THE SUPERCELL RNG THIS AFTN. FOR NOW...WE WILL INDICATE POTNL FOR
+RA AND GUSTY WINDS WITH TSRA THIS AFTN/EVNG.
ACTIVITY SHUD SLIDE INTO NE PA BY EARLY EVNG...WITH BEST CHCS FOR
SHRA/TSRA PERSISTING ACRS THIS AREA TNGT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
UPR LOW CONTINUE TO DIG INTO THE GTLAKES THIS PD WHILE ASSUMING A
NEUTRAL OR SLIGHTLY NEGATIVELY TILT. MSTR XPCTD TO MOV BACK NWD
AHEAD OF THE NXT S/WV AND SFC FNT LATE MON AND MON NGT. SOME
TIMING DIFFS EMERGE LATE IN THE PD BUT TREND WILL BE FOR IMPRVG
CONDITIONS ACRS THE RGN ON TUE NGT. XCPTN MAY BE ACRS THE POCONOS
AND SRN CATSKILLS WHERE POTNL FOR MDT TO HVY SHRA/TSRA MAY EXIST
AS AS A WAVE OF LOW PRES LIFTS NEWD ALONG THE FNT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
345 AM UPDATE...
ONLY MINOR CHGS TO LONG TERM GRIDS AS MODELS HV FINALLY COME INTO
AGREEMENT WITH FROPA OCCURRING BY WED MRNG. UL TROF WL BE HANGING BACK
TO THE WEST WITH SLGT CHC FOR SHOWERS DRG THE DAY WED. TROF LIFTS
OUT ON THURSDAY WITH SFC HIPRES BUILDING IN. THUS, HV KEPT
THURSDAY DRY BFR MOISTURE BEGINS TO CREEP NWD ON FRIDAY IN THE
FORM OF SLGT CHC THUNDER AS HIPRES SHIFTS OFF THE EAST COAST AND
RETURN FLOW BEGINS TO KICK IN.
TEMPS SIMILAR TO PRIOR FCST WITH TEMPS BLO NORMAL BY THE MIDDLE OF
THE WEEK, HIGHS IN THE M70S AND LOWS IN THE L50 AND POSSIBLY U40S
IN NOTORIOUS CLDR VLY LOCATIONS. TEMPS WL MODERATE INTO NEXT
WEEKEND AS SRLY FLOW WL DRAW WARM AIR BACK TO THE REGION.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
12Z UPDATE...
PATCH OF MVFR CIGS HAS DEVELOPED OVER BGM AND AVP THIS MORNING.
EXPECT MVFR CIGS WILL STICK AROUND BETWEEN 12Z AND 13Z BEFORE
SHIFTING SOUTHEAST. EXPECT -TSRA TO DEVELOP ALONG PRE-FRONTAL
TROUGH AFTER 16Z AND CONTINUE THROUGH MOST OF THE AFTERNOON WITH
POTENTIAL MVFR VSBYS AT TIMES. FURTHER SOUTH AT AVP, DO NOT EXPECT
TSRA TO MOVE IN UNTIL 20Z.
IN WAKE OF STORMS, EXPECT LOW-LEVEL MOISTURE TO RESULT IN MVFR
RESTRICTIONS FOR ITH, ELM, BGM AND AVP AFTER 06Z MONDAY. POTENTIAL
EXISTS FOR IFR AT ELM, THUS HAVE TEMPO`D IN 2SM BETWEEN 09Z AND
12Z. AT AVP, SHRA/TSRA MAY CONTINUE THROUGH THE BULK OF THE
OVERNIGHT THOUGH CONFIDENCE IS LOW ON THIS OCCURRING AND IS
DEPENDENT ON HOW IMPENDING WAVE TRACKS.
WINDS 3-8 KTS FROM THE SOUTH WILL BECOME GUSTY OUT OF THE SW THIS
AFTERNOON THEN DIMINISH WITH SUNSET AFTER 00Z.
OUTLOOK...
MON THROUGH TUE NGT...POTENTIAL RESTRICTIONS FROM SHRA/TSRA.
WED/THUR...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RRM
SHORT TERM...
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
646 AM EDT SUN JUL 13 2014
.SYNOPSIS...
AN UPPER LEVEL LOW DIGGING INTO THE GREAT LAKES WILL BRING PERIODS
OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS. THE
ASSOCIATED FRONTAL SYSTEM WILL WORK OFFSHORE BY TUESDAY
NIGHT...WITH DRIER WEATHER AND COOLER TEMPERATURES WORKING INTO
CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UNSETTLED PTRN OVER THE NXT FEW DAYS AS STRONG UPR LOW...WITH
S/WV`S PIVOTING ARND IT...DROPS SEWD INTO THE GTLAKES. MDLS TDA
SHOW THE DVLPMNT OF A PRE-FNTL TROF ACRS CNTRL NY AND PA THIS
AFTN...WITH CDFNT MOVG INTO WRN NY.
LOW LVL JET FOCUSES ACRS WRN NY ACRS LAKE ONTARIO INTO THE ST
LAWRENCE WHERE BEST UPR LVL DVRGNC WILL BE LOCATED. BIG QUESTION WILL BE
AMT OF HEATING WE GET TDA. ATTM IT APPEARS THAT SUNSHINE WILL BE
LIMITED WITH ALOT OF CONVECTIVE DEBRIS ACRS THE RGN THIS MRNG. MESO
DATA ACTUALLY SHOWS SFC TEMPS FALLING THIS AFTN ACRS CNTRL NY WITH
PSSG OF A CONVECTIVE LINE. NAM CAPES MAX OUT BETWEEN 500-1000
J/KG. GFS CAPES MUCH LESS GNRLY 250-500. LCL WRF GETS CAPE UP TO
750 J/KG BUT INDICATES A TALL SKINNY CAPE. WIND FIELDS LOOK GOOD
HOWEVER. PRECIPITABLE H20 VALUES APRCHNG 2 INCHES. RUC BRN`S IN
THE SUPERCELL RNG THIS AFTN. FOR NOW...WE WILL INDICATE POTNL FOR
+RA AND GUSTY WINDS WITH TSRA THIS AFTN/EVNG.
ACTIVITY SHUD SLIDE INTO NE PA BY EARLY EVNG...WITH BEST CHCS FOR
SHRA/TSRA PERSISTING ACRS THIS AREA TNGT.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
UPR LOW CONTINUE TO DIG INTO THE GTLAKES THIS PD WHILE ASSUMING A
NEUTRAL OR SLIGHTLY NEGATIVELY TILT. MSTR XPCTD TO MOV BACK NWD
AHEAD OF THE NXT S/WV AND SFC FNT LATE MON AND MON NGT. SOME
TIMING DIFFS EMERGE LATE IN THE PD BUT TREND WILL BE FOR IMPRVG
CONDITIONS ACRS THE RGN ON TUE NGT. XCPTN MAY BE ACRS THE POCONOS
AND SRN CATSKILLS WHERE POTNL FOR MDT TO HVY SHRA/TSRA MAY EXIST
AS AS A WAVE OF LOW PRES LIFTS NEWD ALONG THE FNT.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
345 AM UPDATE...
ONLY MINOR CHGS TO LONG TERM GRIDS AS MODELS HV FINALLY COME INTO
AGREEMENT WITH FROPA OCCURRING BY WED MRNG. UL TROF WL BE HANGING BACK
TO THE WEST WITH SLGT CHC FOR SHOWERS DRG THE DAY WED. TROF LIFTS
OUT ON THURSDAY WITH SFC HIPRES BUILDING IN. THUS, HV KEPT
THURSDAY DRY BFR MOISTURE BEGINS TO CREEP NWD ON FRIDAY IN THE
FORM OF SLGT CHC THUNDER AS HIPRES SHIFTS OFF THE EAST COAST AND
RETURN FLOW BEGINS TO KICK IN.
TEMPS SIMILAR TO PRIOR FCST WITH TEMPS BLO NORMAL BY THE MIDDLE OF
THE WEEK, HIGHS IN THE M70S AND LOWS IN THE L50 AND POSSIBLY U40S
IN NOTORIOUS CLDR VLY LOCATIONS. TEMPS WL MODERATE INTO NEXT
WEEKEND AS SRLY FLOW WL DRAW WARM AIR BACK TO THE REGION.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
12Z UPDATE...
PATCH OF MVFR CIGS HAS DEVELOPED OVER BGM AND AVP THIS MORNING.
EXPECT MVFR CIGS WILL STICK AROUND BETWEEN 12Z AND 13Z BEFORE
SHIFTING SOUTHEAST. EXPECT -TSRA TO DEVELOP ALONG PRE-FRONTAL
TROUGH AFTER 16Z AND CONTINUE THROUGH MOST OF THE AFTERNOON WITH
POTENTIAL MVFR VSBYS AT TIMES. FURTHER SOUTH AT AVP, DO NOT EXPECT
TSRA TO MOVE IN UNTIL 20Z.
IN WAKE OF STORMS, EXPECT LOW-LEVEL MOISTURE TO RESULT IN MVFR
RESTRICTIONS FOR ITH, ELM, BGM AND AVP AFTER 06Z MONDAY. POTENTIAL
EXISTS FOR IFR AT ELM, THUS HAVE TEMPO`D IN 2SM BETWEEN 09Z AND
12Z. AT AVP, SHRA/TSRA MAY CONTINUE THROUGH THE BULK OF THE
OVERNIGHT THOUGH CONFIDENCE IS LOW ON THIS OCCURRING AND IS
DEPENDENT ON HOW IMPENDING WAVE TRACKS.
WINDS 3-8 KTS FROM THE SOUTH WILL BECOME GUSTY OUT OF THE SW THIS
AFTERNOON THEN DIMINISH WITH SUNSET AFTER 00Z.
OUTLOOK...
MON THROUGH TUE NGT...POTENTIAL RESTRICTIONS FROM SHRA/TSRA.
WED/THUR...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
LONG TERM...PVN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1005 AM EDT SUN JUL 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND OVER THE AREA FROM OFFSHORE THROUGH
MONDAY. A COLD FRONT WILL MOVE INTO THE AREA ON TUESDAY AND
BECOME STATIONARY THROUGH MID WEEK. THE COLD FRONT WILL PUSH
OFFSHORE AND WEAKEN BY THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 10 AM SUNDAY...SOME MIXED SIGNALS FROM THE VARIOUS HIGH-RES
MODELS CONCERNING ANY CONVECTIVE ACTIVITY THIS AFTERNOON WITH THE
3 KM HRRR AND NSSL WRF SHOWING A FEW SHOWERS/TSTMS POPPING UP
AFTER 18Z OVER THE SOUTHERN ZONES...WHILE THE RAP REMAINS DRY.
GIVEN SOME WEAK INSTABILITY...WILL HAVE AN ISOLATED SHOWER/TSTM
CHANCE OVER MAINLY AREAS SOUTH OF HIGHWAY 70 THIS AFTERNOON. HIGH
TEMPERATURES WILL GENERALLY BE IN THE 84 TO 92 DEGREE RANGE AND NO
CHANGES TO TEMP FORECAST IS NEEDED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 330 AM SUNDAY...WARM AND DRY CONDITIONS TONIGHT WITH LIGHT
S-SW WINDS KEEPING TEMPS SEVERAL DEGS WARMER THAN SUN MORNING. LOWS
FROM LOWER 70S INLAND TO MID-UPR 70S COAST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 345 AM SUN...TYPICAL SUMMERTIME PATTERN WILL BE IN PLACE
MON WITH RIDGE SURFACE AND ALOFT CENTERED OFF THE SOUTHEASTERN
COAST...AND WEAK PIEDMONT TROUGH ACROSS THE CAROLINAS. WILL
MAINTAIN PREVIOUS TREND OF SLIGHT CHANCE POPS OFF THE COAST WHERE
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ALONG/NEAR THE GULF
STREAM...TRANSITIONING TO SLIGHT CHANCE POPS INLAND WITH MODEST
INSTABILITY DURING THE AFTERNOON HOURS. SHEAR REMAINS NIL SO DO
NOT EXPECT SEVERE WX AT THIS TIME THOUGH CANNOT COMPLETELY RULE
OUT. TEMPS WILL BE A FEW DEGREES ABOVE NORMAL FOR MAX TEMPS WITH
HIGHS 92-95 F INLAND AND 82-84 F ALONG THE COAST.
A STRONG UPPER LEVEL TROUGH WILL DIG SOUTH THROUGH THE NORTHERN
GREAT LAKES MON AND TUES. A STRONG SHORTWAVE WILL BE LOCATED
NEAR WISCONSIN MON THAT WILL ROTATE AROUND THE BASE OF THE UPPER
TROUGH TUES HELPING TO PUSH LOWER HEIGHTS TOWARDS THE REGION FROM
THE NORTHWEST. A SURFACE LOW LOOKS TO FORM ACROSS THE SOUTHERN
GREAT LAKES WHICH WILL DRAG A SLOW MOVING COLD FRONT INTO THE
REGION TUES INTO WED. THE RIDGE ALONG THE SOUTHEASTERN COAST WILL
BE SHUNTED WELL OFFSHORE TUES THOUGH IT WILL HELP FOCUS A RICH
SOUTHERLY MOISTURE STREAM FROM THE GULF OF MEXICO AND SOUTHWESTERN
ATLANTIC OCEAN TUES THROUGH WED. THE COLD FRONT WILL APPROACH LATE
TUES AND MOVE INTO EASTERN NC WED. FORECAST SOUNDINGS INDICATE
PWATS FALLING TO AROUND 1.50 INCHES MON NIGHT THEN RAMPING BACK
ABOVE 2 INCHES TUES INTO WED. MAINTAINED TREND OF INCREASING POPS
MON NIGHT THROUGH TUES...TO LIKELY BY TUES AFTERNOON. MAX TEMPS
WILL FALL A FEW DEGREES TUES DUE TO INCREASED CLOUDS INHIBITING
MAXIMUM INSOLATION...THOUGH LOW LEVEL THICKNESSES REMAIN ROUGHLY
1425 METERS MON AND TUES. BEST CHANCE FOR SEVERE STORMS APPEARS TO
BE TUES AFTERNOON WHEN SLIGHTLY GREATER SHEAR EXISTS ACROSS THE
REGION AND MOISTURE REMAINS ABUNDANT.
THE COLD FRONT WILL BE SLOW TO PUSH OFFSHORE WED BUT HAVE TRENDED
POPS DOWN SLIGHTLY FROM PREVIOUS FORECAST FOR WED AND WED NIGHT...AS
WE WILL LIKELY BE ON THE WEST SIDE OF THE STALLED BOUNDARY BY 18Z-
00Z THURS. LOW LEVEL THICKNESSES FALL TO AROUND 1405-1410 WED
WHICH YIELDS TEMPS IN THE MID 80S INLAND TO LOW 80S ALONG THE
COAST. SOME DIFFERENCES APPEAR IN THE EXTENDED RANGE GUIDANCE
BEGINNING THURS AFTERNOON THROUGH THE WEEKEND. 00Z ECMWF KEEPS
EASTERN NC MOSTLY DRY...ON THE WESTERN SIDE OF THE STALLED
BOUNDARY THURS NIGHT INTO FRI...WHILE THE 00Z GFS SHIFTS THE
BOUNDARY BACK INLAND THURS NIGHT...WITH A SERIES OF WEAK SURFACE
WAVES FORMING ALONG THE STALLED BOUNDARY. GIVEN UNCERTAINTY THIS
FAR OUT IN TIME...CAN NOT RULE OUT GFS SCENARIO THUS TRIED TO
BLEND PREVIOUS FORECAST WITH 00Z GFS/ECMWF WHICH MEANS A SLIGHT
CHANCE/CHANCE OF SHOWERS AND THUNDERSTORMS THURS NIGHT THROUGH
FRI. GUIDANCE INDICATES THE STALLED BOUNDARY WILL LIFT NORTH
THROUGH THE REGION SAT...LEADING TO INCREASED CHANCES FOR PRECIP
SAT/SAT AFTERNOON.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 730 AM SUNDAY...CURRENT MVFR VSBYS AT KPGV AND KOAJ WILL
IMPROVE TO VFR BY 13Z...THEN VFR EXPECTED ALL SITES THROUGH REST OF
TAF PERIOD. DIURNAL CU/SCU EXPECTED DURING AFTN BUT EXPECT THREAT OF
SHOWERS/TSTMS TO REMAIN S OF AREA. MOSTLY CLEAR CONDITIONS FOR
TONIGHT. SW WINDS WILL INCREASE TO AROUND 10 KT THIS AFTN...AND
REMAIN AROUND 5 KT TONIGHT...LIMITING FOG DEVELOPMENT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 AM SUN...WITH WEAK RIDGING...EXPECT GENERALLY VFR
CONDITIONS MONDAY AS ANY CONVECTION WILL BE LIMITED TO THE SEA
BREEZE IN THE AFTERNOON AND EVENING. A STALLED FRONTAL BOUNDARY
AND DEEP LONGWAVE TROUGH WILL BE IN PLACE TUES THROUGH LATE
WEEK...PROVIDING A DEEP MOISTURE FEED FROM THE GULF. EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS WITH OCCASIONAL MVFR
CEILINGS/VSBYS THROUGH THE REMAINDER OF THE PERIOD WITH ALSO SOME
LOWER VSBYS IN FOG AT NIGHT...PERHAPS IFR/LIFR AT TIMES.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1005 AM SUNDAY...NO BIG CHANGES TO THE MARINE FORECAST.
WINDS ARE GENERALLY W/SW WITH SOME WNW WINDS OVER THE FAR NORTHERN
WATERS. SPEEDS ARE LESS THAN 10 KNOTS...BUT LATEST RUC SHOWS WINDS
MAY BUMP UP TO 10 TO 15 KNOTS WITH BETTER MIXING IN THE AFTERNOON.
PREVIOUS FCST SEAS ON TRACK FOR TODAY BUT LOWERED A BIT TONIGHT
BASED ON LATEST NWPS. HEIGHTS AT 2-3 FT THIS AFTN AND AROUND 3
FOR TONIGHT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 AM SUN...THE GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND
A SHARPENING SURFACE TROUGH OVER THE PIEDMONT WILL LEAD TO MODERATE
SOUTHWEST WINDS THROUGH MIDWEEK. ANTICIPATE 15 TO 20 KNOT WINDS
WITH SEAS GENERALLY 3 TO 4 FEET AND OCCASIONALLY UP TO 5 FEET.
WINDS WILL LIKELY BACK TO A MORE EASTERLY DIRECTION OVER THE
NORTHERN WATERS BY THURSDAY AS THE FRONTAL BOUNDARY PUSHED OFFSHORE.
WINDS WILL ALSO DIMINISH A BIT ON THURSDAY WITH THE STALLED FRONTAL
BOUNDARY OFFSHORE. WINDS SHIFT ENE/E ON THURSDAY BUT REMAIN 10 KT
OR LESS...WHICH WILL RESULT IN SEAS MOSTLY 2-4 FT ACROSS THE WATERS.
LOCAL SWAN/NWPS AND 00Z WAVEWATCH GUIDANCE IN FAIRLY GOOD AGREEMENT
THROUGH THE MEDIUM RANGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...JBM/CTC/DAG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
806 AM EDT SUN JUL 13 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TODAY AND A MUCH STRONGER
COLD FRONT WILL PUSH INTO THE GREAT LAKES ON MONDAY. HIGH PRESSURE
WILL BEGIN TO BUILD IN FOR MID WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE UPDATE LOWERED THE POPS OVER THE SOUTHERN PORTION OF THE
FORECAST AREA AND KEPT LIKELY IN THE NORTH MAINLY FOR THE AM.
STILL EXPECTING MORE SHOWERS AND THUNDERSTORMS TO DEVELOP OVER THE
SOUTHERN PORTION OF THE FORECAST THIS AFTERNOON AS THE COLD FRONT
GETS CLOSER. IF THE CLOUDS THIN ENOUGH OVER THE SOUTHERN PORTION
OF THE FORECAST AREA THAT WILL ENHANCE THE CHANCE OF SOME SEVERE
THUNDERSTORMS THIS AFTERNOON.
PREVIOUS DISCUSSION...
NOT A CLEAR CUT FORECAST FOR TODAY. A COLD FRONT WILL BE MOVING
THROUGH TODAY. THE HRRR MODEL SEEMS TO HAVE A GOOD HANDLE ON THE
SITUATION IN QUICKLY MOVING THE FIRST ROUND OF PRECIPITATION THROUGH
BY AROUND 11 AM AND THEN DEVELOPS MORE SHOWERS AND THUNDERSTORMS
FROM NW PA SW THROUGH THE FDY AREA INTO THE AFTERNOON AS THE
AIRMASS DRIES OUT FROM THE NORTH. AT THIS TIME THE FIRST ROUND OF
SHOWERS AND THUNDERSTORMS IS WEAKENING...SOME LOCALLY HEAVY RAIN
IS STILL POSSIBLE. SOME STRONGER WINDS ALOFT SO WATCHING THE
POTENTIAL FOR SOME GUSTY WINDS WITH SOME OF THE THUNDERSTORMS
ESPECIALLY THIS MORNING. THE THREAT OF SEVERE SHOULD BE MAINLY
INLAND FROM LAKE ERIE.
SINCE WE WILL HAVE SOME DRY SPELLS EVEN THOUGH MOST AREAS WILL
REMAIN MOSTLY CLOUDY...EXCEPT ALONG THE LAKESHORE DIDN`T GO COOLER
THAN GUIDANCE..USED A BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
SOME SHOWERS AND THUNDERSTORMS WILL BE LINGERING MAINLY OVER THE
SOUTHERN PORTION OF THE FORECAST AREA EARLY IN THE EVENING.
FOR MONDAY AFTERNOON INTO MONDAY NIGHT WENT WITH CHANCE POPS AS
ANOTHER FRONT WILL BE MOVING THROUGH. AT THIS TIME JUST KEPT THEM
CHANCE POPS AS THE AMOUNT OF MOISTURE IS NOT REAL
HIGH...HOWEVER...SOME OF THE MOS GUIDANCE IS INDICATING 60% POPS.
THIS WILL HAVE TO BE WATCHED.
FOR TUESDAY...GUIDANCE POPS ARE SOMEWHAT LOW BUT CONTINUED A
CHANCE OVER NE OH AND NW PA BECAUSE OF INSTABILITY SHOWERS WITH
THE LAKE AND 850 MB TEMPERATURE DIFFERENCE GETTING CLOSE TO 14C.
ALSO INCLUDED A LOW CHANCE OF THUNDER. A SLIGHT CHANCE OF SHOWERS
WILL LINGER IN THE SNOW BELT AREAS THROUGH WEDNESDAY NIGHT.
HOWEVER...ON WEDNESDAY WITH THE UPPER TROF SWINGING THROUGH WILL
HAVE CHANCE POPS OVER MUCH OF THE FORECAST AREA.
TEMPERATURES WILL BE MUCH BELOW NORMAL STARTING TUESDAY. A BIG
DIFFERENCE IN THE GUIDANCE FOR THE LOWS TONIGHT. USED A BLEND WITH
SOME DECREASE IN CLOUDS AND DRY WEATHER...SOME DRYING SHOULD
OCCUR.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
UPPER LEVEL TROUGH WILL LIFT TOWARDS QUEBEC ON THURSDAY AS HIGH
PRESSURE BUILDS OVERHEAD AT THE SURFACE. A LOW CHANCE POP REMAINS
OVER THE HIGHER TERRAIN OF NW PA BUT OTHERWISE EXPECT MOSTLY DRY
CONDITIONS WITH HEIGHTS STARTING TO CLIMB AND THE AIRMASS DRYING
OUT. LOCATIONS DOWNWIND OF LAKE ERIE IN NE OH/NW PA WILL STILL BE
FAIRLY COOL WITH HIGHS NEAR 70 DEGREES WHILE NW/CENTRAL OHIO WILL
START TO RECOVER WITH HIGHS IN THE MID 70S. DRYING TREND CONTINUES
ON FRIDAY WITH HIGHS WARMING ANOTHER 3-4 DEGREES.
BY SATURDAY WE WILL HAVE TO KEEP AN EYE ON A WEAK UPPER TROUGH
LIFTING THROUGH THE TENNESSEE AND OHIO VALLEYS. MOISTURE WILL
ATTEMPT TO SPREAD NORTH AHEAD OF THE TROUGH ACROSS EASTERN OHIO
WHICH COULD LEAD TO AN INCREASED CU FIELD AND MAYBE EVEN A LOW
CHANCE OF SHOWERS. CONFIDENCE IS TOO LOW IN MOISTURE RETURN TO ADD
POPS TO THE FORECAST BUT IT WILL BE SOMETHING TO CONSIDER OVER
FUTURE MODEL RUNS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHOWERS WITH SCATTERED THUNDERSTORMS MOVING ACROSS THE AREA THIS
MORNING AS AN AREA OF LOW PRESSURE PASSES NORTH OF LAKE ERIE. A
MOIST AIRMASS IS IN PLACE BUT WILL SLOWLY SHIFT SOUTH AS A WEAK
FRONT SINKS DOWN FROM THE NORTH. INITIAL ROUND OF SHOWERS WILL END
BY ABOUT 14-15Z AT TOL AND CLE...LINGERING INTO THE AFTERNOON AT THE
OTHER SITES. SOMEWHAT UNCERTAINTY ABOUT COVERAGE OF THUNDERSTORMS
THIS AFTERNOON ALONG THE SLOW MOVING FRONT BUT EXPECT SOME
INCREASE IN CONVECTION AT MFD/CAK/YNG. STRONG TO SEVERE
THUNDERSTORMS ARE POSSIBLE AT THE SOUTHERN SITES...ESPECIALLY IF
CLOUDS CLEAR AND ALLOW FOR A LONGER PERIOD OF CLEARING. SOUTHWEST
WINDS COULD BE BREEZY AT TIMES AHEAD OF THE FRONT WITH WINDS
POSSIBLY SHIFTING TO THE WEST OFF LAKE ERIE AT CLE/ERI BEHIND THE
RAIN.
EXPECT CLOUDS TO CLEAR OUT OF MOST SITES BY THIS EVENING. WINDS WILL
BE LIGHT AND BR/FOG COULD DEVELOP WITH HIGH DEWPOINTS...MAINLY AT
THE SOUTHERN SITES CLOSER TO THE FRONTAL BOUNDARY.
OUTLOOK...NON VFR POSSIBLE SUNDAY AFTERNOON THROUGH TUESDAY IN
THUNDERSTORMS.
&&
.MARINE...
SOUTHWESTERLY WINDS WILL INCREASE TODAY AS LOW PRESSURE PASSES NORTH
OF LAKE ERIE THIS MORNING...WITH WINDS ON EASTERN LAKE ERIE NEAR 20
KNOTS AT TIMES. THE TROUGH WILL LIFT TOWARDS QUEBEC THIS AFTERNOON
WITH WINDS SHIFTING TO WESTERLY LATER TODAY AND NW THIS EVENING. IT
LOOKS LIKE THE WINDS MAINTAIN ENOUGH OF A SW OFFSHORE COMPONENT THAT
WAVES PEAK IN THE 2 TO 4 FOOT RANGE...JUST BELOW SMALL CRAFT
ADVISORY CRITERIA. WILL HAVE TO KEEP AN EYE ON WINDS AND WAVE
REPORTS...ESPECIALLY IN THE PENNSYLVANIA WATERS...AND MAY STILL NEED
TO ISSUE AN ADVISORY IF CONDITIONS GET CLOSE ENOUGH.
A STRONGER COLD FRONT WILL MOVE ACROSS THE LAKE ON TUESDAY WITH
WINDS ONCE AGAIN INCREASING TO THE 15 TO 20 KNOT RANGE.
SOUTHWESTERLY WINDS WILL SHIFT TO WESTERLY AND WAVES WILL BUILD DOWN
THE LONG FETCH OF THE LAKE. THE COOLER AIRMASS WILL ALLOW FOR BETTER
WAVE GROWTH AND A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED EAST OF
CLEVELAND WITH WAVES OF 3 TO 5 FEET. WATERSPOUTS MAY ALSO BE
POSSIBLE THROUGH THE MID-WEEK TIME FRAME GIVEN FAVORABLE INSTABILITY
OVER THE LAKE. HIGH PRESSURE WILL BUILD OVERHEAD BY THURSDAY WITH
GOOD MARINE CONDITIONS TO END THE WEEK.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
728 AM EDT SUN JUL 13 2014
.SYNOPSIS...
A STRONG UPPER LEVEL TROUGH WILL DROP INTO THE UPPER GREAT LAKES
BY MONDAY. A PAIR OF COLD FRONTS ASSOCIATED WITH THE TROUGH WILL
HANG UP TO THE NORTHWEST OF THE STATE BRIEFLY...BUT EVENTUALLY
PASS THROUGH AND USHER IN COOLER AND DRIER AIR FOR MIDWEEK. THE
COOL CONDITIONS WILL LAST THROUGH LATE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A TROUGH ALOFT IS PRODUCING A BAND OF SHOWERS AND THUNDERSTORMS
THAT IS MOVING INTO NORTHWEST PA AT 09Z. THIS FEATURE IS TIMED TO
CROSS THE NORTHWESTERN MOUNTAINS DURING THE EARLY MORNING. THE
SHOWERS WILL START TO PULL FROM SOME LOWER- DEWPOINT AIR AS IT
MOVES INTO THE ALLEGHENIES...AND SHOULD WEAKEN AND PERHAPS
DISSIPATE BY 12Z AS IT TRIES TO GET INTO THE CENTRAL MTS. THIS
FEATURE IS PRACTICALLY IGNORED BY THE RAP AND HRRR. HOWEVER...MOST
MODELS DO DEVELOP HIGH INSTABILITY AND BUILD CAPE OVER THE ENTIRE
AREA LATER THIS MORNING.
IF THE CLOUD DEBRIS AND COOLING EFFECTS THEREOF ARE NOT TOO
SIGNIFICANT TODAY...THE CAPES THIS AFTN COULD TOP 1500 JOULES. THE
SPC HAS ALMOST THE ENTIRE AREA IN THE SLIGHT RISK AREA TODAY INTO
TONIGHT. THE MAIN FORCING FROM THE MCC TO OUR NW ROLLS THROUGH
RIGHT DURING PEAK HEATING AS WELL. WILL ADD SOME ENHANCED WORDING
TO THE WX GRIDS AT THIS POINT...BUT NOT MENTION SEVERE OUTSIDE THE
HWO. RAINFALL COULD BE HEAVY ACROSS THE NRN TIER...BUT THE SPEED
OF THE CELLS WILL MAKE IT DIFFICULT FOR A SINGLE BURST OF RAIN TO
MAKE ANY FLOODING. MULTIPLE/REPEATED STORMS ARE LIKELY IN THE
NORTHWESTERN HALF OF THE AREA THROUGH THE NEAR TERM...AND THIS MAY
CAUSE LOCAL FLOODING. FFG/S CONTINUE TO BE RATHER HIGH AND SERIOUS
PROBLEMS/FLASH FLOODING IS NOT ANTICIPATED AT THIS TIME. LOCALLY
HEAVY RAIN NEAR LEBANON AND LANCASTER HAS LOWERED FLOOD GUIDANCE
THERE...BUT THE STORMS WILL BE MORE-SCATTERED AROUND THAT LOCAL
AREA TODAY.
THE THICKNESS/PERSISTENCE OF THE CLOUD COVER TODAY WILL BE THE
TRICK TO WHERE TEMPS GO. DUE TO THE CLOUDS AND ANTICIPATED
CONVECTION/RAIN - WILL HANG WITH CONTINUITY AND ADD ABOUT 10F TO
THE CURRENT TEMPS IN THE NW AND ABOUT 15F TO THE CURRENT TEMPS IN
THE SE FOR MAXES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
CONVERGENCE WILL CONCENTRATE FROM JST-UNV-IPT THIS EVENING...AND
ONLY SINK SLOWLY TO THE SOUTH. BUT THIS FIRST SHOT OF COOLER AIR
FROM THE NORTHWEST IS NOT ENOUGH TO DISPLACE THE WARM AIR AND HIGH
MOISTURE SO ADDITIONAL STORMS ARE EXPECTED OVERNIGHT.
REDEVELOPMENT IS ALMOST SURELY IN THE CARDS FOR MONDAY AS CLOUDS
THIN BRIEFLY AND JULY SUN STIRS UP THE BOUNDARY LAYER OVER MOST
OF THE AREA. SLIGHT RISK OUTLOOK FROM SPC IS HELD TO JUST THE S/SE
THIRD OF THE AREA MONDAY. HOWEVER...FEEL THAT STRONG STORMS ARE
POSSIBLE A LITTLE FARTHER TO THE NORTH WITH LOW-LEVEL AMBIENT
MOISTURE STILL HIGH AND OVERALL MOISTURE HIGH WITH PWATS BETWEEN
1.5 AND 2 INCHES. WILL HOLD THE CATG POPS TO THE SE...BUT GO
LIKELY POPS OVER MUCH OF THE REST OF THE AREA ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE GFS AND NAM GUIDANCE IS MUCH QUICKER TO PUSH THE FRONT
THROUGH...WITH THE ECMWF DEEPENING THE UPPER LEVEL TROUGH...THOUGH
THE LATEST RUN HAS OPENED UP THE CLOSED LOW. THE EC DEVELOPS A
COHERENT SFC LOW OVER THE MID MS VALLEY AND MOVES IT TO OUR W/N ON
TUESDAY AS IT DEEPENS TO NEAR 1003MB.
HIGH AMPLITUDE RIDGE/TROUGH PATTERN DEVELOPS ACROSS THE MUCH OF
NORTH AMERICA BEGINNING LATE IN THE WEEKEND...AND CONTINUES
THROUGH THE FIRST HALF OF NEXT WEEK.
THE BRUNT OF THE GREATEST 850-700 MB TEMP ANOMALIES AND
ASSOCIATED BELOW NORMAL 500 MB HEIGHTS WILL BE AIMED AT THE LOWER
OHIO VALLEY AND MID MISS VALLEY TUESDAY AND WEDNESDAY...WITH OUR
REGION RESIDING ON THE ACTIVE/EASTERN SIDE OF THIS SLOW MOVING
FEATURE.
AS ADDITIONAL ENERGY IS DRIVEN SSE INTO THE BACK SIDE OF THE HIGH
AMPLITUDE MIDWEST TROUGH...PROLONGED HIGH PWAT AIR /AND LIFT
BENEATH THE RIGHT ENTRANCE REGION OF AN UPPER JET/ MAY LINGER
ACROSS THE SERN ZONES WITH SCATTERED...MAINLY AFTERNOON TSRA
WEDNESDAY AFTERNOON.
THE PATTERN OVER THE NRN CONUS AND SRN CANADA APPEARS TO DE-
AMPLIFY LATER NEXT WEEK AS THE EASTERN U.S. TROUGH BEGINS TO SHEAR
OUT TO THE NE.
THE DRIEST PERIOD OF THE LONG TERM WILL BE THURSDAY AND
FRIDAY...THOUGH SOME ISOLATED CONVECTION STILL CANT BE RULED OUT
EITHER OF THOSE TWO DAYS.
TEMPS START OUT AOA NORMAL PRECEDING THE CFROPA NEXT SUNDAY...AND
PERHAPS MONDAY ACROSS THE SE ZONES...THEN COOL TO AT LEAST 4-6F
BELOW NORMAL FOR DAYTIME HIGHS TUESDAY THROUGH THURSDAY. TEMPS
WILL LIKELY REBOUND TO NEAR NORMAL LATE NEXT WEEK.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AN APPROACHING FRONT WILL BRING THE CHANCE OF TSRA IMPACTS TO THE
NW MTNS TODAY. SCT SHRA/TSRA APPROACHING KBFD NOW WILL SPREAD
SEWD THROUGHOUT THE DAY...BUT SITES WILL REMAIN MAINLY VFR
THROUGH THE TAF PERIOD. BRIEF REDUCTIONS IN VSBY AND CIGS ARE
POSSIBLE AGAIN TOMORROW AFTERNOON IN THUNDERSTORMS.
OUTLOOK...
SUN...BRIEF THUNDERSTORM IMPACTS POSSIBLE.
SUN NIGHT-MON NIGHT...NUMEROUS SHOWERS/TSRA WITH MAINLY BRIEF
PERIODS OF IFR TO MVFR.
TUES-WED...THUNDERSTORM IMPACTS POSSIBLE...MAINLY IN THE
AFTERNOON.
THU...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...CERU
AVIATION...GARTNER
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
628 AM CDT SUN JUL 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT SUN JUL 13 2014
MAIN SHORT TERM CONCERN IS ON RAIN POTENTIAL TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED STRONG UPPER RIDGING OVER THE WESTERN U.S. INTO WESTERN
CANADA...WHILE AN ANONYMOUSLY DEEP TROUGH OVER MANITOBA AND NORTHERN
ONTARIO WAS SLOWLY SINKING SOUTH. A PROMINENT DRY SLOT AHEAD OF THE
DESCENDING TROUGH HELPED KICKED THE SHOWERS AND STORMS OUT OF THE
FORECAST AREA BY 03Z LAST EVENING. NORTHWEST FLOW OF 20-35 KT FROM
925MB TO 700MB ALSO WAS BRINGING MUCH DRIER AIR INTO THE AREA...
NOTED BY PRECIPITABLE WATER DOWN TO 1 INCH COMPARED TO AS HIGH AS 2
INCHES AT 00Z. SURFACE DEWPOINTS ARE STILL RELATIVELY HIGH...IN THE
LOW 60S...RESULTING MOSTLY FROM MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. THAT TRAPPING HAS LED TO SOME LOW STRATUS AND FOG
DEVELOPMENT OVERNIGHT. ANOTHER SLUG OF EVEN DRIER AIR WAS EVIDENT
OVER NORTH DAKOTA AND NORTHERN MN WITH PRECIPITABLE WATER AT 0.5
INCH...ALONG WITH SURFACE DEWPOINTS IN THE 40S AND 50S. THIS DRIER
AIR WAS LOCATED BEHIND A COLD FRONT STRETCHING FROM NORTHWEST WI
INTO WEST CENTRAL MN. SOME DYING SHOWERS WERE OVER NORTHWEST WI WITH
THIS FRONT...TIED MOSTLY WITH A SHORTWAVE CROSSING WESTERN LAKE
SUPERIOR. OTHERWISE...THE FRONT IS MOSTLY CLOUD FREE. TEMPERATURE
WISE...850MB TEMPS WERE GENERALLY 13-16C FROM NORTH DAKOTA INTO
WISCONSIN AT 00Z. HOWEVER...5C READINGS WERE SEEN LURKING OVER
CENTRAL MANITOBA WITHIN THE DEEP UPPER TROUGH.
MODELS ARE IN GOOD AGREEMENT DROPPING THE COLD FRONT OVER CENTRAL MN
SOUTHEASTWARD THROUGH THE FORECAST AREA THIS MORNING. DAYTIME
HEATING COMBINED WITH THE LINGERING MOISTURE AROUND WILL LIKELY LEAD
TO A DECENT AMOUNT OF CUMULUS AHEAD OF THE FRONT. ALTHOUGH THE
DETERMINISTIC NAM/GFS/CANADIAN SUGGEST A DRY FRONTAL PASSAGE...NEW
13.00Z ECMWF AS WELL AS THE 13.05Z HRRR AND 3 OF THE 4 HOPWRF
MEMBERS RUN BY THE MPX OFFICE SUGGEST A BAND OF SHOWERS WILL OCCUR
WITH THE FRONT. DEVELOPMENT TIME OCCURS AROUND 14Z / 9 AM AND SINKS
TO THE SOUTH OUT OF THE AREA BY 19Z / 2 PM. INCLUDED A 20 PERCENT
CHANCE AND ISOLATED SHOWERS FOR THIS SHOWER POTENTIAL. DID NOT PUT
ANY THUNDER WITH IT AS THE CAPE IS ONLY PROGGED AT 100-200 J/KG AND
ALL OF THE CAPE IS BELOW THE FREEZING LEVEL. AS THE FRONT PASSES AND
THE LOWER PRECIPITABLE WATER ADVECTS IN BEHIND IT...EXPECT THE
CUMULUS TO GRADUALLY DISSIPATE ALONG WITH DEWPOINTS DROPPING THROUGH
THE 50S. NORTHWEST WINDS SHOULD BECOME A BIT BREEZY TOO IN THE WAKE
OF THE FRONTAL PASSAGE GIVEN A FAVORABLE DEEPER MIXING ENVIRONMENT.
ATTENTION TONIGHT TURNS TO A POTENT SHORTWAVE WITHIN THE DEEP TROUGH
LOCATED IN NORTHEAST MANITOBA. MODELS DROPS THIS SHORTWAVE OVER THE
NORTHERN HALF OF MN BY 12Z...WITH AN UPPER LOW ALSO INDICATED AT
500MB. DPVA AHEAD OF THIS FEATURE COMBINED WITH THE MOIST AND MUCH
COOLER AIR WITHIN THE TROUGH IS EXPECTED TO SPREAD SHOWERS INTO
NORTHWEST WI BY 12Z MONDAY. BELIEVE THESE SHOULD STAY AWAY FROM
TAYLOR COUNTY BEFORE 12Z. SOME CLOUD INCREASE IS LIKELY NORTH OF I-
90 AFTER MIDNIGHT...THOUGH. A SECONDARY COLD FRONTAL PASSAGE SHOULD
COME INTO AND POSSIBLY THROUGH THE AREA BY 12Z AS WELL. ADVECTION
BEHIND THIS FRONT WILL ALLOW TEMPERATURES TO DIP INTO THE 50S...WITH
EVEN A FEW UPPER 40S POSSIBLE IN CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 259 AM CDT SUN JUL 13 2014
THE MAIN ISSUE HERE IN THE LONG TERM IS WITH THE TRACK OF THE UPPER
LOW IN NORTHERN MN AT 12Z MONDAY. THE ECMWF HAS BEEN PERSISTENT AS A
SLOWER...MORE AMPLIFIED SOLUTION...TAKING THE UPPER LOW ACROSS
CENTRAL AND NORTHERN WI MONDAY EVENING AND ACROSS LOWER MICHIGAN ON
TUESDAY. HOWEVER...THE 13.00Z CANADIAN/NAM/GFS ALL ARE IN STEP WITH
EACH OTHER SHOWING A TRACK ACROSS UPPER MICHIGAN ON MONDAY...AND
INTO EAST CENTRAL ONTARIO ON TUESDAY. THESE DIFFERENCES ARE
SIGNIFICANT AS IT IMPACTS THE LOCATION OF DPVA AND DIURNALLY
ENHANCED SHOWER POTENTIAL...ALONG WITH HOW COLD TEMPERATURES WILL BE
MONDAY AND TUESDAY. IT SHOULD BE NOTED THAT THE 13.00Z ECMWF HAS
TRENDED JUST SLIGHTLY TOWARDS THE CANADIAN/NAM/GFS. TO HANDLE THE
DIFFERENCE BETWEEN THESE TWO SOLUTIONS...HAVE DECIDED TO STAY PRETTY
CLOSE TO THE PREVIOUS FORECAST...WHICH WOULD BE IN-LINE WITH A MODEL
CONSENSUS IDEA.
FOR MONDAY...WE SHOULD GRADUALLY SEE SHOWER COVERAGE INCREASE
THROUGH THE DAY AS THE UPPER LOW AND ASSOCIATED COLD AIR ALOFT
APPROACH. THE MOST NUMEROUS COVERAGE IS ANTICIPATED NORTH OF HIGHWAY
29 CLOSER TO THE UPPER LOW. THESE SHOWERS SHOULD MOSTLY DIMINISH
MONDAY NIGHT DUE TO THE LOSS OF DAYTIME HEATING. TUESDAYS RAIN
CHANCES ARE A BIT MORE QUESTIONABLE NOW AFTER SEEING THE 13.00Z
ECMWF. THE FLOW IS STILL CYCLONIC INTO THE REGION...BUT DRY AIR IS
ADVECTING IN AT THE SAME TIME. THE CANADIAN/GFS/NAM ARE ALL
DRY...AND NOW THE ECMWF ONLY HAS SOME LIGHT QPF BETWEEN 12-18Z
TUESDAY BEFORE DRYING OUT. HAVE THEREFORE TRENDED PRECIPITATION
CHANCES LOWER A BIT AND DRIED OUT LOCATIONS WEST OF THE MISSISSIPPI
RIVER. REGARDING TEMPERATURES...850MB TEMPS PLUMMET TO 4-6C IN THE
MORNING WHICH WILL KEEP HIGHS MOSTLY IN THE 60S. THE LONE EXCEPTION
TO THAT IS IN FAR SOUTHWEST WI WHERE THE COLDER AIR ENTERS LAST AND
HAS MORE SUN POTENTIAL IN THE MORNING. WITH LESS SHOWER POTENTIAL ON
TUESDAY...HAVE RAISED HIGHS SLIGHTLY BUT THEY ARE STILL A FAR CRY
FROM NORMAL.
BENIGN WEATHER CONTINUES TO BE THE RULE AFTER TUESDAY. UPPER
TROUGHING DOMINATES MUCH OF THE EASTERN U.S. WEDNESDAY INTO THURSDAY
WITH THE FORECAST AREA ON THE BACK SIDE OF THE TROUGH. THIS FAVORS
SUBSIDENCE ALOFT AND DRYING HIGH PRESSURE AT THE SURFACE. THE GFS
CONTINUES TO SPLATTER LIGHT QPF AROUND DURING THE AFTERNOON AND
EVENINGS AS A RESULT OF TOO MUCH EVAPOTRANSPIRATION. AS WE HEAD INTO
FRIDAY AND SATURDAY...500MB HEIGHTS LOOK TO RISE ACROSS MUCH OF THE
EASTERN U.S. AS THE TROUGH LIFTS OUT. IN FACT...WE COULD EVEN BE
UNDER UPPER RIDGING BY SATURDAY AS A SHORTWAVE TROUGH SLIDES ACROSS
THE NORTHERN ROCKIES. THIS PATTERN HEADING INTO SATURDAY FAVORS A
CONTINUATION OF DRY CONDITIONS ALONG WITH A NICE WARMING TREND
TOWARDS CLOSER TO NORMAL. MUCH OF THE MORE HUMID AIR LOOKS TO BE
STUCK ACROSS THE SOUTHERN U.S. THANKS TO THE COLD/DRY AIR FROM
EARLIER THIS WEEK DROPPING ALL THE WAY DOWN TO THE GULF COAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 628 AM CDT SUN JUL 13 2014
GENERALLY GOOD VFR EXPECTED THIS PERIOD AS DRIER CANADIAN HIGH
PRESSURE BUILDS INTO THE UPPER MIDWEST. THE LEADING EDGE OF THIS IS
A COLD FRONT THAT WILL PUSH ACROSS THE TAF SITES THIS MORNING. A
BAND OF 2000-3500 FT CLOUDS TO ACCOMPANY THIS FRONT ACROSS THE AREA
WITH WHAT LOOKS TO BE A SHORT PERIOD OF BKN020-BKN030 CLOUDS AT THE
TAF SITES AS IT PASSES. SOME WEAK INSTABILITY EXPECTED TO DEVELOP
NEAR THE FRONT BY LATER THIS MORNING. FRONT MAY STILL BE IN THE KLSE
AREA WHEN THIS OCCURS AND THERE MAY BE A BRIEF PERIOD OF VCSH AT
KLSE AROUND 15-16Z. BETTER SIGNAL IS THAT IF ANY -SHRA DO DEVELOP
NEAR THE FRONT LATE THIS MORNING/EARLY THIS AFTERNOON IT WILL BE
SOUTH OF KLSE...AND LEFT VCSH MENTION OUT OF THE TAF. DEEPER MIXING
TODAY AND TIGHTER GRADIENT WILL RESULT IN NORTHWEST WINDS 10-15KT
G18-23KT LATE THIS MORNING THRU MID AFTERNOON. NORTHWEST WINDS 5-
10KT AND DRIER BOUNDARY LATER AIRMASS SHOULD KEEP LATE NIGHT/EARLY
MON MORNING BR IN THE FCST AREA TO A MINIMUM.
&&
.CLIMATE...
ISSUED AT 259 AM CDT SUN JUL 13 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE MONDAY AND TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI RIVER
VALLEY.
FOR LA CROSSE...
MONDAY....FORECAST HIGH 68. RECORD 65 IN 1994
TUESDAY...FORECAST HIGH 70. RECORD 68 IN 1962
FOR ROCHESTER...
MONDAY....FORECAST HIGH 64. RECORD 64 IN 1952
TUESDAY...FORECAST HIGH 67. RECORD 67 IN 1962
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RRS
CLIMATE......AJ
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
220 PM MST SUN JUL 13 2014
.UPDATE...UPDATED AVIATION DISCUSSION.
.SYNOPSIS...
MONSOON MOISTURE WILL CONTINUE TO INCREASE ACROSS THE REGION THROUGH
MONDAY...WITH INCREASED CHANCES OF THUNDERSTORMS AND SLIGHTLY COOLER
TEMPERATURES THROUGH MID WEEK. A DRYING AND WARMING TREND IS THEN
EXPECTED STARTING WEDNESDAY...LIKELY LASTING INTO NEXT WEEKEND.
&&
.DISCUSSION...
CONVECTION IS BEGINNING TO FIRE ALONG THE MOGOLLON RIM ON THE
LEADING EDGE OF A REMNANT MCV...AND ISNT WASTING ANY TIME MOVING TO
THE WEST. STRONG WINDS /BY MONSOON STANDARDS/ OF 15-20KTS WERE NOTED
IN THE 700-500MB LAYER THIS MORNING ON REGIONAL UPPER AIR SOUNDINGS
AND THIS CERTAINLY WILL HELP STORMS MOVE OFF THE HIGHER TERRAIN
LATER THIS AFTERNOON. STILL LOOKING AT A DECENT AMOUNT OF MOISTURE
ACROSS THE AREA...PWATS REMAIN AROUND 1.4 TO 1.5 INCHES WHICH IS
APPROX 130-140 PERCENT OF NORMAL FOR MID JULY. MEANWHILE ACROSS THE
DESERTS...THE ATMOSPHERE CONTINUES TO DESTABILIZE WITH LATEST RAP
ANALYSIS INDICATING AROUND 500 J/KG MLCAPE WITH LITTLE TO NO CAP.
STILL LOOKING AT A COMPLICATED FORECAST FOR THE REGION THIS
AFTERNOON AND EVENING. GOING TO STICK WITH THE IDEA THAT STORMS WILL
DEVELOP AND MOVE INTO THE DESERTS LATER TODAY BASED ON LATEST HI-RES
GUIDANCE AND OBSERVED INSTABILITY TRENDS. HRRR...LOCAL WRF
ENSEMBLE...AND RAP ALL INDICATE STORMS WILL MOVE THROUGH THE
METRO...THEN GRADUALLY DISSIPATE LATER THIS EVENING. WENT AHEAD AND
RAISED POPS INTO THE 20-30 PERCENT RANGE ACROSS THE
METRO...COLLIDING OUTFLOWS WILL LIKELY BE THE MAIN FORCING
MECHANISM. WINDS AND BLOWING DUST WILL BE THE PRIMARY THREATS WITH
THESE STORMS...ESPECIALLY ACROSS THE OPEN DESERTS SOUTH OF PHOENIX.
SIGNIFICANT INCREASE IN MOISTURE IS ON TAP FOR THE REGION LATE
TONIGHT INTO MONDAY MORNING AS PWATS WILL CLIMB
SUBSTANTIALLY...REACHING AROUND 2 INCHES BY 12Z MONDAY. AS
ALWAYS...HOW THE BOUNDARY LAYER WILL RECOVER AFTER THIS SURGE...HOW
CLOUDY IT WILL BE...ETC...WILL DICTATE JUST HOW ACTIVE THINGS WILL
BE LATER IN THE AFTERNOON. A SAMPLING OF NAM AND GFS BUFR SOUNDINGS
ACROSS THE AREA FOR TOMORROW AFTERNOON INDICATE THE BOUNDARY LAYER
SHOULD MIX OUT SUFFICIENTLY TO ALLOW FOR STORM DEVELOPMENT LATER IN
THE AFTERNOON. CONSENSUS AMONG RECENT RUNS OF HI-RES MODELS AND 4KM
NAM IS THAT STORMS WILL LIKELY FIRE ALONG THE RIM AND PROPAGATE INTO
THE DESERTS. WITH MLCAPE FORECASTS AROUND 1000 J/KG...STARTING TO
LOOK MORE PROMISING FOR STORMS ACROSS THE METRO. STORMS ON MONDAY
WILL MAINLY PRESENT A HEAVY RAINFALL AND FLASH FLOOD THREAT...BUT
THERE IS STILL SOME QUESTION ON HOW MUCH SUN WILL MANAGE TO PEAK
THROUGH THE CLOUDS WHICH COULD LIMIT INSTABILITY.
TEMPERATURES WILL BE ON THE DOWN TREND THROUGH EARLY THIS WEEK...BUT
THIS AFTERNOON WILL STILL PEAK OUT ABOVE SEASONAL NORMALS WITH SOME
PLACES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA BREAKING
THE 110 DEGREE MARK. AFTER THE SURGE OF MOISTURE TONIGHT...MONDAY/S
HIGHS WILL TAKE A BIG HIT...POSSIBLY NOT EVEN BREAKING 100 ACROSS
SOME LOWER DESERT SPOTS DEPENDING ON HOW MUCH STORM AND CLOUD
COVERAGE THERE ENDS UP BEING.
ABUNDANT MOISTURE WILL STILL BE PRESENT ACROSS ARIZONA INTO
TUESDAY...BUT MODELS ARE NOW POINTING TOWARD AN EARLIER TIMEFRAME
FOR DRY AIR WORKING IN FROM THE SOUTHWEST. HAVE REMOVED SLIGHT
CHANCES ACROSS MOST OF OUR WESTERN ZONES DUE TO THE LOW LEVEL DRY
AIR WORKING IN...BUT SLIGHT TO CHANCE POPS REMAIN ACROSS ARIZONA.
THE SUBTROPICAL HIGH CENTER SHIFTS SOUTHEASTWARD OUT OF THE GREAT
BASIN ON TUESDAY WHILE SETTLING SOMEWHERE OVER SOUTHERN ARIZONA OR
NORTHERN MEXICO BY WEDNESDAY. THIS SHIFT WILL SWITCH OUR FLOW OUT
THE SOUTHWEST WHICH WILL QUICKLY SCOUR OUT MOISTURE FROM SOUTHWEST
TO NORTHEAST FROM TUESDAY AFTERNOON THROUGH LATE WEDNESDAY. BOTH THE
EUROPEAN AND THE GFS ARE POINTING AT A SIGNIFICANT DRYING TREND FOR
LATE THIS WEEK...LIKELY RESULTING IN VERY LITTLE MONSOON ACTIVITY
FROM WEDNESDAY THROUGH SATURDAY.
GIVEN THE LIKELY SOUTHWESTERLY DRYING FLOW...HAVE TRIMMED BACK POPS
QUITE A BIT STARTING WEDNESDAY. THE DRIEST DAY WILL END UP BEING
EITHER THURSDAY OR FRIDAY...BEFORE SOME MOISTURE LIKELY STARTS
SEEPING BACK INTO OUR REGION NEXT WEEKEND. TEMPERATURES WILL GET A
BUMP DURING THIS TIMEFRAME...BUT FORECAST 500MB HEIGHTS ARE ONLY IN
THE 590-592DM RANGE WHICH WOULD GIVE US HIGHS A COUPLE DEGREES ABOVE
NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...MOSTLY
SOUTHERLY TO SOUTHEASTERLY WINDS ACROSS THE TERMINALS BUT WITH AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS AFTER 23Z EXTENDING
OUT TO 04Z. GUSTY WINDS COULD ACCOMPANY ANY THUNDERSTORMS AND
BLOWING DUST ALSO A POSSIBLE THREAT. WINDS COULD BE VARIABLE AND
GUSTY UNTIL 04Z GOING BACK TO SOUTHEASTERLY THE REST OF THE NIGHT.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SOUTHERLY WINDS UNTIL 02Z WITH MOSTLY CLEAR SKIES OTHER THAN A
CHANCE OF SCT HIGH CLOUDS. NO SIG AVIATION WEATHER IMPACTS EXPECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AIR WILL ALREADY BE PROPAGATING THROUGH THE WESTERN PARTS OF
THE DISTRICT TUESDAY...SPREADING THROUGHOUT MUCH OF CNTRL ARIZONA BY
THE END OF THE WEEK. THEREFORE...THE BEST OPPORTUNITY FOR SHOWERS
AND THUNDERSTORMS WILL BE RELEGATED TO GILA COUNTY...WITH LITTLE TO
NO CHANCE OF PRECIPITATION IN SOUTHEAST CALIFORNIA THROUGH THIS
PERIOD. WINDS WILL REMAIN RATHER LIGHT WITH ONLY OCCASIONAL
AFTERNOON GUSTS...THOUGH SOME STRONGER GUSTS WILL ACCOMPANY ANY
AFTERNOON AND EVENING THUNDERSTORMS IN GILA COUNTY. WITH THE DRYING
TREND...MINIMUM HUMIDITY LEVELS WILL FALL BACK INTO THE LOWER TEENS
BY THE END OF THE WEEK WITH GOOD OVERNIGHT RECOVERY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/KUHLMAN
AVIATION...WATERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1217 PM MST SUN JUL 13 2014
.SYNOPSIS...
MONSOON MOISTURE WILL CONTINUE TO INCREASE ACROSS THE REGION THROUGH
MONDAY...WITH INCREASED CHANCES OF THUNDERSTORMS AND SLIGHTLY COOLER
TEMPERATURES THROUGH MID WEEK. A DRYING AND WARMING TREND IS THEN
EXPECTED STARTING WEDNESDAY...LIKELY LASTING INTO NEXT WEEKEND.
&&
.DISCUSSION...
CONVECTION IS BEGINNING TO FIRE ALONG THE MOGOLLON RIM ON THE
LEADING EDGE OF A REMNANT MCV...AND ISNT WASTING ANY TIME MOVING TO
THE WEST. STRONG WINDS /BY MONSOON STANDARDS/ OF 15-20KTS WERE NOTED
IN THE 700-500MB LAYER THIS MORNING ON REGIONAL UPPER AIR SOUNDINGS
AND THIS CERTAINLY WILL HELP STORMS MOVE OFF THE HIGHER TERRAIN
LATER THIS AFTERNOON. STILL LOOKING AT A DECENT AMOUNT OF MOISTURE
ACROSS THE AREA...PWATS REMAIN AROUND 1.4 TO 1.5 INCHES WHICH IS
APPROX 130-140 PERCENT OF NORMAL FOR MID JULY. MEANWHILE ACROSS THE
DESERTS...THE ATMOSPHERE CONTINUES TO DESTABILIZE WITH LATEST RAP
ANALYSIS INDICATING AROUND 500 J/KG MLCAPE WITH LITTLE TO NO CAP.
STILL LOOKING AT A COMPLICATED FORECAST FOR THE REGION THIS
AFTERNOON AND EVENING. GOING TO STICK WITH THE IDEA THAT STORMS WILL
DEVELOP AND MOVE INTO THE DESERTS LATER TODAY BASED ON LATEST HI-RES
GUIDANCE AND OBSERVED INSTABILITY TRENDS. HRRR...LOCAL WRF
ENSEMBLE...AND RAP ALL INDICATE STORMS WILL MOVE THROUGH THE
METRO...THEN GRADUALLY DISSIPATE LATER THIS EVENING. WENT AHEAD AND
RAISED POPS INTO THE 20-30 PERCENT RANGE ACROSS THE
METRO...COLLIDING OUTFLOWS WILL LIKELY BE THE MAIN FORCING
MECHANISM. WINDS AND BLOWING DUST WILL BE THE PRIMARY THREATS WITH
THESE STORMS...ESPECIALLY ACROSS THE OPEN DESERTS SOUTH OF PHOENIX.
SIGNIFICANT INCREASE IN MOISTURE IS ON TAP FOR THE REGION LATE
TONIGHT INTO MONDAY MORNING AS PWATS WILL CLIMB
SUBSTANTIALLY...REACHING AROUND 2 INCHES BY 12Z MONDAY. AS
ALWAYS...HOW THE BOUNDARY LAYER WILL RECOVER AFTER THIS SURGE...HOW
CLOUDY IT WILL BE...ETC...WILL DICTATE JUST HOW ACTIVE THINGS WILL
BE LATER IN THE AFTERNOON. A SAMPLING OF NAM AND GFS BUFR SOUNDINGS
ACROSS THE AREA FOR TOMORROW AFTERNOON INDICATE THE BOUNDARY LAYER
SHOULD MIX OUT SUFFICIENTLY TO ALLOW FOR STORM DEVELOPMENT LATER IN
THE AFTERNOON. CONSENSUS AMONG RECENT RUNS OF HI-RES MODELS AND 4KM
NAM IS THAT STORMS WILL LIKELY FIRE ALONG THE RIM AND PROPAGATE INTO
THE DESERTS. WITH MLCAPE FORECASTS AROUND 1000 J/KG...STARTING TO
LOOK MORE PROMISING FOR STORMS ACROSS THE METRO. STORMS ON MONDAY
WILL MAINLY PRESENT A HEAVY RAINFALL AND FLASH FLOOD THREAT...BUT
THERE IS STILL SOME QUESTION ON HOW MUCH SUN WILL MANAGE TO PEAK
THROUGH THE CLOUDS WHICH COULD LIMIT INSTABILITY.
TEMPERATURES WILL BE ON THE DOWN TREND THROUGH EARLY THIS WEEK...BUT
THIS AFTERNOON WILL STILL PEAK OUT ABOVE SEASONAL NORMALS WITH SOME
PLACES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA BREAKING
THE 110 DEGREE MARK. AFTER THE SURGE OF MOISTURE TONIGHT...MONDAY/S
HIGHS WILL TAKE A BIG HIT...POSSIBLY NOT EVEN BREAKING 100 ACROSS
SOME LOWER DESERT SPOTS DEPENDING ON HOW MUCH STORM AND CLOUD
COVERAGE THERE ENDS UP BEING.
ABUNDANT MOISTURE WILL STILL BE PRESENT ACROSS ARIZONA INTO
TUESDAY...BUT MODELS ARE NOW POINTING TOWARD AN EARLIER TIMEFRAME
FOR DRY AIR WORKING IN FROM THE SOUTHWEST. HAVE REMOVED SLIGHT
CHANCES ACROSS MOST OF OUR WESTERN ZONES DUE TO THE LOW LEVEL DRY
AIR WORKING IN...BUT SLIGHT TO CHANCE POPS REMAIN ACROSS ARIZONA.
THE SUBTROPICAL HIGH CENTER SHIFTS SOUTHEASTWARD OUT OF THE GREAT
BASIN ON TUESDAY WHILE SETTLING SOMEWHERE OVER SOUTHERN ARIZONA OR
NORTHERN MEXICO BY WEDNESDAY. THIS SHIFT WILL SWITCH OUR FLOW OUT
THE SOUTHWEST WHICH WILL QUICKLY SCOUR OUT MOISTURE FROM SOUTHWEST
TO NORTHEAST FROM TUESDAY AFTERNOON THROUGH LATE WEDNESDAY. BOTH THE
EUROPEAN AND THE GFS ARE POINTING AT A SIGNIFICANT DRYING TREND FOR
LATE THIS WEEK...LIKELY RESULTING IN VERY LITTLE MONSOON ACTIVITY
FROM WEDNESDAY THROUGH SATURDAY.
GIVEN THE LIKELY SOUTHWESTERLY DRYING FLOW...HAVE TRIMMED BACK POPS
QUITE A BIT STARTING WEDNESDAY. THE DRIEST DAY WILL END UP BEING
EITHER THURSDAY OR FRIDAY...BEFORE SOME MOISTURE LIKELY STARTS
SEEPING BACK INTO OUR REGION NEXT WEEKEND. TEMPERATURES WILL GET A
BUMP DURING THIS TIMEFRAME...BUT FORECAST 500MB HEIGHTS ARE ONLY IN
THE 590-592DM RANGE WHICH WOULD GIVE US HIGHS A COUPLE DEGREES ABOVE
NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...
VERY LOW CONFIDENCE IN WIND DIRECTION/WIND SHIFTS THIS AFTERNOON
THROUGH MONDAY MORNING...AS PRESUMABLY NUMEROUS THUNDERSTORM
OUTFLOWS CREATE A CHAOTIC PATTERN AS THE SFC. EXPECTING AN ELY WIND
COMPONENT TO PREVAIL INTO THE MID/LATE AFTERNOON...WITH SOME CHANCE
THE TYPICAL AFTERNOON WEST WIND NEVER MATERIALIZES. STRONGER OUTFLOW
WINDS...BLOWING DUST...AND ISOLD/SCT SHRA/TSRA MAY HAVE HIGH IMPACT
FOR TERMINALS WITH MVFR OR LOWER FLIGHT CATEGORIES AROUND AND AFTER
00Z. CONFIDENCE IN COVERAGE AND TIMING IS FAR TOO LOW TO INCLUDE AS
A TAF GROUPING AT THIS TIME...THOUGH WOULD EXPECT SOMEWHAT BETTER
CONFIDENCE ONCE THUNDERSTORMS BEGIN TO DEVELOP. SCT SHOWERS MAY ALSO
CONTINUE THROUGH THE OVERNIGHT HOURS AFFECTING LATE NIGHT TRAFFIC.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT/BKN MID/HIGH CLOUDS WILL GENERALLY LOWER AND THICKEN THROUGH
MONDAY MORNING...THOUGH REMAIN IN THE VFR CATEGORY AS MOISTURE
SURGES NORTH FROM THE GULF OF CALIFORNIA. THIS SURGE MAY CAUSE A
PERIOD OF GUSTINESS FROM THE SOUTH AFTER SUNSET WITH SPEEDS
POTENTIALLY REACHING 25KT. THOUGH NOT INCLUDED IN THIS TAF PACKAGE
DUE TO LOW CONFIDENCE...SHRA/TSRA MAY RAPIDLY DEVELOP LATE NIGHT AND
IMPACT TERMINALS THROUGH MONDAY MORNING WITH LOCALLY REDUCED VSBY IN
MDT/HVY RAIN.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AIR WILL ALREADY BE PROPAGATING THROUGH THE WESTERN PARTS OF
THE DISTRICT TUESDAY...SPREADING THROUGHOUT MUCH OF CNTRL ARIZONA BY
THE END OF THE WEEK. THEREFORE...THE BEST OPPORTUNITY FOR SHOWERS
AND THUNDERSTORMS WILL BE RELEGATED TO GILA COUNTY...WITH LITTLE TO
NO CHANCE OF PRECIPITATION IN SOUTHEAST CALIFORNIA THROUGH THIS
PERIOD. WINDS WILL REMAIN RATHER LIGHT WITH ONLY OCCASIONAL
AFTERNOON GUSTS...THOUGH SOME STRONGER GUSTS WILL ACCOMPANY ANY
AFTERNOON AND EVENING THUNDERSTORMS IN GILA COUNTY. WITH THE DRYING
TREND...MINIMUM HUMIDITY LEVELS WILL FALL BACK INTO THE LOWER TEENS
BY THE END OF THE WEEK WITH GOOD OVERNIGHT RECOVERY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/KUHLMAN
AVIATION...MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1007 AM MST SUN JUL 13 2014
.SYNOPSIS...
MONSOON MOISTURE WILL INCREASE ACROSS THE REGION TODAY. THE MOISTURE
SURGE WILL OVERTAKE ALL OF THE REGION ON MONDAY WITH INCREASED
CHANCES OF THUNDERSTORMS AND SLIGHTLY COOLER TEMPERATURES. A DRYING
AND WARMING TREND IS THEN EXPECTED STARTING WEDNESDAY...LIKELY
LASTING INTO NEXT WEEKEND.
&&
.DISCUSSION...
MORNING WATER VAPOR IMAGERY REVEALS A DECAYING COMPLEX OF STORMS
OVER THE GULF OF CALIFORNIA...WITH ANOTHER WEAK CIRCULATION OVER
SOUTHEAST ARIZONA. PWATS PER 12Z PSR AND TWC SOUNDINGS REVEAL VALUES
AROUND 1.5-1.6 INCHES...THIS MATCHES WELL WITH BLENDED TPW IMAGERY
AND GPS IPW READINGS. NOT SURPRISINGLY...DEWPOINTS HAVE BEEN SLOW TO
MIX OUT THIS MORNING WITH MOST OF THE PHOENIX AREA STILL SEEING
DEWPOINTS IN THE UPPER 50S TO LOWER 60S. DESPITE THE INCREASED
MOISTURE...DESERT TEMPS HAVE HAD NO PROBLEM WHATSOEVER CLIMBING INTO
THE UPPER 90S/LOWER 100S AS OF 17Z.
COMPLICATED FORECAST FOR THE REGION THIS AFTERNOON AS MOISTURE WILL
STEADILY INCREASE THROUGHOUT THE DAY. STORMS WILL ONCE AGAIN
INITIATE ALONG THE RIM AND CARRY WESTWARD INTO THE DESERTS. HOWEVER
UNLIKE YESTERDAY...THERE WILL ACTUALLY BE SOME INSTABILITY TO WORK
WITH AROUND THE PHOENIX AREA /ALBEIT ONLY 200-300 J/KG OF
MLCAPE...MUCH LESSER VALUES WEST OF THE METRO/. GIVEN MODEST MID
LEVEL LAPSE RATES AND 700-500MB WIND SPEEDS AROUND 15-20KTS...FEEL
IT PRUDENT TO RAISE POPS A BIT ACROSS THE METRO SINCE STORMS HAVE A
BETTER CHANCE OF MAKING IT INTO THE DESERTS. HRRR...LOCAL WRF
ENSEMBLE...AND RAP ALL INDICATE STORMS WILL MOVE THROUGH THE
METRO...THEN GRADUALLY DISSIPATE LATER THIS EVENING. WENT AHEAD AND
RAISED POPS INTO THE 20-30 PERCENT RANGE ACROSS THE
METRO...COLLIDING OUTFLOWS WILL LIKELY BE THE MAIN FORCING
MECHANISM. THUS CONFIDENCE IN THE EXACT PLACEMENT AND TIMING OF
STORMS THIS EVENING IS LOW. WINDS AND BLOWING DUST WILL BE THE
PRIMARY THREATS WITH THESE STORMS...ESPECIALLY ACROSS THE OPEN
DESERTS SOUTH OF PHOENIX.
&&
.PREVIOUS DISCUSSION...
AS THE INVERTED TROUGH SHIFTS WESTWARD LATER THIS EVENING...LOW
LEVEL WINDS WILL SHIFT TO THE SOUTHEAST ALLOWING FOR A SIGNIFICANT
MOISTURE SURGE TO PUSH ACROSS SOUTHERN ARIZONA BY MIDNIGHT AND INTO
SOUTHEAST CALIFORNIA BY MONDAY MORNING. DUE TO THE MOISTURE SURGE
AND PROBABLE HELP FROM THE INVERTED TROUGH...WOULD NOT BE SURPRISED
IF SHOWERS AND A FEW THUNDERSTORMS PERSIST THROUGH THE OVERNIGHT
HOURS TONIGHT. MONDAY WILL LIKELY TURN OUT TO BE A FAIRLY WET DAY
ACROSS PORTIONS OF THE CWA AS FORECAST PRECIPITABLE WATER VALUES
REACH ABOVE 2 INCHES CENTERED OVER YUMA. STORMS ON MONDAY WILL
MAINLY PRESENT A HEAVY RAINFALL AND FLASH FLOOD THREAT...BUT THERE
IS STILL SOME QUESTION ON HOW MUCH SUN WILL MANAGE TO PEAK THROUGH
THE CLOUDS WHICH COULD LIMIT INSTABILITY.
TEMPERATURES WILL BE ON THE DOWN TREND THROUGH EARLY THIS WEEK...BUT
THIS AFTERNOON WILL STILL PEAK OUT ABOVE SEASONAL NORMALS WITH SOME
PLACES ACROSS SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA BREAKING
THE 110 DEGREE MARK. AFTER THE SURGE OF MOISTURE TONIGHT...MONDAY/S
HIGHS WILL TAKE A BIG HIT...POSSIBLY NOT EVEN BREAKING 100 ACROSS
SOME LOWER DESERT SPOTS DEPENDING ON HOW MUCH STORM AND CLOUD
COVERAGE THERE ENDS UP BEING.
ABUNDANT MOISTURE WILL STILL BE PRESENT ACROSS ARIZONA INTO
TUESDAY...BUT MODELS ARE NOW POINTING TOWARD AN EARLIER TIMEFRAME
FOR DRY AIR WORKING IN FROM THE SOUTHWEST. HAVE REMOVED SLIGHT
CHANCES ACROSS MOST OF OUR WESTERN ZONES DUE TO THE LOW LEVEL DRY
AIR WORKING IN...BUT SLIGHT TO CHANCE POPS REMAIN ACROSS ARIZONA.
THE SUBTROPICAL HIGH CENTER SHIFTS SOUTHEASTWARD OUT OF THE GREAT
BASIN ON TUESDAY WHILE SETTLING SOMEWHERE OVER SOUTHERN ARIZONA OR
NORTHERN MEXICO BY WEDNESDAY. THIS SHIFT WILL SWITCH OUR FLOW OUT
THE SOUTHWEST WHICH WILL QUICKLY SCOUR OUT MOISTURE FROM SOUTHWEST
TO NORTHEAST FROM TUESDAY AFTERNOON THROUGH LATE WEDNESDAY. BOTH THE
EUROPEAN AND THE GFS ARE POINTING AT A SIGNIFICANT DRYING TREND FOR
LATE THIS WEEK...LIKELY RESULTING IN VERY LITTLE MONSOON ACTIVITY
FROM WEDNESDAY THROUGH SATURDAY.
GIVEN THE LIKELY SOUTHWESTERLY DRYING FLOW...HAVE TRIMMED BACK POPS
QUITE A BIT STARTING WEDNESDAY. THE DRIEST DAY WILL END UP BEING
EITHER THURSDAY OR FRIDAY...BEFORE SOME MOISTURE LIKELY STARTS
SEEPING BACK INTO OUR REGION NEXT WEEKEND. TEMPERATURES WILL GET A
BUMP DURING THIS TIMEFRAME...BUT FORECAST 500MB HEIGHTS ARE ONLY IN
THE 590-592DM RANGE WHICH WOULD GIVE US HIGHS A COUPLE DEGREES ABOVE
NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...
VERY LOW CONFIDENCE IN WIND DIRECTION/WIND SHIFTS THIS AFTERNOON
THROUGH MONDAY MORNING...AS PRESUMABLY NUMEROUS THUNDERSTORM
OUTFLOWS CREATE A CHAOTIC PATTERN AS THE SFC. EXPECTING AN ELY WIND
COMPONENT TO PREVAIL INTO THE MID/LATE AFTERNOON...WITH SOME CHANCE
THE TYPICAL AFTERNOON WEST WIND NEVER MATERIALIZES. STRONGER OUTFLOW
WINDS...BLOWING DUST...AND ISOLD/SCT SHRA/TSRA MAY HAVE HIGH IMPACT
FOR TERMINALS WITH MVFR OR LOWER FLIGHT CATEGORIES AROUND AND AFTER
00Z. CONFIDENCE IN COVERAGE AND TIMING IS FAR TOO LOW TO INCLUDE AS
A TAF GROUPING AT THIS TIME...THOUGH WOULD EXPECT SOMEWHAT BETTER
CONFIDENCE ONCE THUNDERSTORMS BEGIN TO DEVELOP. SCT SHOWERS MAY ALSO
CONTINUE THROUGH THE OVERNIGHT HOURS AFFECTING LATE NIGHT TRAFFIC.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCT/BKN MID/HIGH CLOUDS WILL GENERALLY LOWER AND THICKEN THROUGH
MONDAY MORNING...THOUGH REMAIN IN THE VFR CATEGORY AS MOISTURE
SURGES NORTH FROM THE GULF OF CALIFORNIA. THIS SURGE MAY CAUSE A
PERIOD OF GUSTINESS FROM THE SOUTH AFTER SUNSET WITH SPEEDS
POTENTIALLY REACHING 25KT. THOUGH NOT INCLUDED IN THIS TAF PACKAGE
DUE TO LOW CONFIDENCE...SHRA/TSRA MAY RAPIDLY DEVELOP LATE NIGHT AND
IMPACT TERMINALS THROUGH MONDAY MORNING WITH LOCALLY REDUCED VSBY IN
MDT/HVY RAIN.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
DRIER AIR WILL ALREADY BE PROPAGATING THROUGH THE WESTERN PARTS OF
THE DISTRICT TUESDAY...SPREADING THROUGHOUT MUCH OF CNTRL ARIZONA BY
THE END OF THE WEEK. THEREFORE...THE BEST OPPORTUNITY FOR SHOWERS
AND THUNDERSTORMS WILL BE RELEGATED TO GILA COUNTY...WITH LITTLE TO
NO CHANCE OF PRECIPITATION IN SOUTHEAST CALIFORNIA THROUGH THIS
PERIOD. WINDS WILL REMAIN RATHER LIGHT WITH ONLY OCCASIONAL
AFTERNOON GUSTS...THOUGH SOME STRONGER GUSTS WILL ACCOMPANY ANY
AFTERNOON AND EVENING THUNDERSTORMS IN GILA COUNTY. WITH THE DRYING
TREND...MINIMUM HUMIDITY LEVELS WILL FALL BACK INTO THE LOWER TEENS
BY THE END OF THE WEEK WITH GOOD OVERNIGHT RECOVERY.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/KUHLMAN
AVIATION...MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1142 AM MDT SUN JUL 13 2014
.UPDATE...
ISSUED AT 1122 AM MDT SUN JUL 13 2014
UPDATE ON FLASH FLOOD WATCH...SOME CONVECTION IS ALREADY STARTING
OVER THE WALDO CANYON BURN SCAR WITH ABUNDANT LOW LEVEL MOISTURE.
WATER VAPOR SHOWS DRYING ALOFT OVER NORTHERN COLORADO MOVING
SOUTHWARD. SUSPECT THIS IS SOME SUBSIDENCE AHEAD OF THE SHORTWAVE
IN CENTRAL WYOMING...WHERE SOME CONVECTION IS ALREADY BEGINNING.
SUBSIDENCE ALOFT WILL TEND TO CAP CONVECTION OVER THE PLAINS
DURING THE DAY. THERE WILL BE ENOUGH HEATING OVER THE MOUNTAINS
AND NEARBY PLAINS FOR CONVECTION TO DEVELOP DURING THE AFTERNOON.
THE HIGH RESOLUTION MODELS SUGGEST CONVECTION ASSOCIATED WITH THE
SHORTWAVE WILL MOVE SOUTHWARD ACROSS THE REGION DURING THE
EVENING HOURS. EARLIER RUNS OF THE HRRR AND THE CURRENT 12Z 4KM
NMM WRF WERE THE MOST ZEALOUS WITH THUNDERSTORMS IN THE EVENING.
IN THE GRIDS...INCREASED SOME POPS IN THE EVENING ESPECIALLY OVER
THE NORTHERN PORTIONS OF THE EASTERN MOUNTAINS AND INTERSTATE 25
CORRIDOR. WITH SOME DRYING ALOFT...PRECIPITABLE WATERS HAVE
MODESTLY DECREASED FROM YESTERDAY...BUT THERE STILL IS ENOUGH LOWER
AND MID LEVEL MOISTURE FOR STORMS TO PRODUCE HEAVY DOWNPOURS. A
SIZABLE PORTION OF THE WATCH AREA RECEIVED SIGNIFICANT
PRECIPITATION YESTERDAY...AND AMOUNTS FOR FLASH FLOODING WILL BE
LESS. --PGW--
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 410 AM MDT SUN JUL 13 2014
...HEAVY RAIN POTENTIAL CONTINUES TODAY...
CURRENT WATER VAPOR IMAGERY INDICATING WEAK TO MODERATE NORTHWEST
FLOW ALOFT ACROSS THE REGION WITH HIGH AMPLITUDE RIDGING IN PLACE
ACROSS THE DESERT SOUTHWEST THROUGH THE PAC NORTHWEST AS AN
UNSEASONABLY STRONG UPPER LOW IS SPINNING JUST NORTH OF THE UPPER
GREAT LAKES REGION. KPUX RADAR INDICATING AN MCV SPINNING ACROSS THE
FAR SE PLAINS WITH SCATTERED SHOWERS SLOWLY DIMINISHING AT THIS
TIME.
DUAL POL RADAR ESTIMATES ARE INDICATING LAST NIGHTS SLOW MOVING
THUNDERSTORMS PRODUCED WIDESPREAD RAINFALL AMOUNTS OF 1 TO 3 INCHES
ACROSS DROUGHT RAVAGED PORTIONS OF THE LOWER ARKANSAS RIVER
VALLEY...ALONG WITH A POCKET OF RAINFALL IN EXCESS OF 5 INCHES IN
SOUTHWESTERN OTERO COUNTY...WHERE LAW ENFORCEMENT HAS ISSUED REVERSE
911 CALLS FOR PEOPLES LIVING ON AND ALONG TIMPAS CREEK...WHICH HAS
BEEN REPORTED TO BE 20 TO 30 FT WIDE IN SPOTS SOUTH OF SWINK. KPUX
RADAR IS ALSO ESTIMATING MORE SPOTTY 1 TO 3 INCHES FROM YESTERDAYS
STORMS ACROSS FREMONT...TELLER...EL PASO...PUEBLO...HUERFANO AND LAS
ANIMAS COUNTIES.
FOR TODAY AND TONIGHT...MODELS CONTINUE TO INDICATE A SLIGHT
INCREASE IN THE NORTHWESTERLY FLOW ALOFT ACROSS THE REGION
TODAY...WITH THE HIGH AMPLITUDE RIDGE PERSISTING ACROSS GREAT BASIN
AND PAC NORTHWEST AS THE UNSEASONABLY STRONG UPPER LOW SLOWLY DIGS
INTO THE UPPER GREAT LAKES. MODELS CONTINUE TO INDICATE SHORT WAVE
ENERGY TRANSLATING DOWN THE EASTERN PERIPHERY OF THE RIDGE ACROSS
THE NORTHERN ROCKIES AND NORTHERN HIGH PLAINS WITH A SECONDARY SURGE
OF COOL AIR BUILDING INTO THE CENTRAL HIGH PLAINS AND INTO EASTERN
COLORADO. SOME DRIER AIR WITHIN THE NORTHERLY FLOW ALOFT LOOKS TO
PUSH THE MAIN MONSOONAL MOISTURE PLUME ACROSS SOUTHERN PORTIONS OF
THE STATE AND INTO THE SOUTHERN ROCKIES. HOWEVER...PRECIP WATERS ARE
PROGGED TO REMAIN HIGH (1.5 TO 2 TIMES NORMAL VALUES) ACROSS THE
AREA WITH READINGS BETWEEN 0.75 INCHES AND 1.5 INCHES...GREATEST
ACROSS THE EASTERN PLAINS. LATEST HIGHER RES MODELS COULD BE PICKING
UP ON DEVELOPING SUBSIDENCE ACROSS THE SE PLAINS ON THE BACK SIDE OF
MCV AS THEY KEEP MOST CONVECTION OVER AND NEAR THE HIGHER TERRAIN
THIS AFTERNOON AND EVENING. AT ANY RATE...WITH STRONG JULY SOLAR
HEATING AND AMPLE MOISTURE...SHOULD SEE SCATTERED TO NUMEROUS STORMS
DEVELOPING ACROSS THE MTS THIS AFTERNOON SPREADING SLOWLY SOUTH AND
EAST ACROSS THE IMMEDIATE ADJACENT PLAINS THROUGH THE LATE AFTERNOON
AND EVENING HOURS. WITH THE SLIGHTLY INCREASED FLOW ALOFT...STORMS
SHOULD BE MOVING A TAD FASTER THAN YESTERDAY...THOUGH WILL STILL
HAVE THE POTENTIAL TO PRODUCE RAIN AMOUNTS OF 1 TO 2 INCHES PER
HOUR. THIS...ALONG WITH WET SOILS FROM YESTERDAYS STORMS...COULD
LEAD TO INCREASED FLASH FLOODING AND ISSUED A FLASH FLOOD WATCH FOR
THE EASTERN MTS AND ADJACENT PLAINS FROM NOON TO 9 PM MDT. HAVE
INCLUDED CROWELY AND OTERO COUNTIES IN THE WATCH WITH THE ONGOING
FLOODING AT THIS TIME. STORMS ACROSS THE AREA TO DIMINISH THROUGH
THE EVENING WITH THE LOSS OF SOLAR HEATING. WITH MORE CLOUD COVER
AND MOIST UPSLOPE FLOW...TEMPERATURES LOOK TO BE BELOW TO WELL BELOW
SEASONAL AVERAGES...ESPECIALLY ACROSS THE EASTERN PLAINS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 410 AM MDT SUN JUL 13 2014
...WET AND STORMY PATTERN TO REMAIN IN PLACE THROUGH WED...
UPPER RIDGE CONTINUES TO SLOWLY RETREAT THROUGH THE GREAT BASIN
MON AS UPPER TROUGH DEEPENS OVER THE GREAT LAKES. NWLY FLOW ALOFT
WILL INCREASE THROUGH THE DAY...WHILE SURFACE COLD FRONT PUSHES
SOUTH ACROSS EASTERN COLORADO BY AFTERNOON. SHOULD SEE A RENEWED
WESTWARD SURGE OF LOW LEVEL MOISTURE OVER THE EASTERN MOUNTAINS
AND PLAINS BEHIND THE FRONT WITH NEAR 60F DEWPOINTS REACHING THE
I-25 CORRIDOR MON EVENING. EXPECT FAIRLY WIDESPREAD CONVECTION
ACROSS THE AREA MON INTO MON NIGHT...AND WHILE STORM MOTION WILL
BE A LITTLE FASTER AS STEERING WINDS INCREASE...LOCALLY HEAVY
RAIN WILL REMAIN POSSIBLE OVER THE EASTERN HALF OF THE AREA.
MAY ALSO SEE SOME STRONG/SEVERE STORMS AS 0-6KM SHEAR VALUES
INCREASE INTO THE 40-50 KT RANGE. MON NIGHT INTO TUE
MORNING...FOCUS SHIFTS SOUTH ACROSS THE NM BORDER AS FRONTAL
BOUNDARY SINKS SOUTH INTO ERN NM/TEX PANH.
PLENTY OF MOISTURE AND INSTABILITY AGAIN IN PLACE OVER THE AREA
TUE AS CAPES WILL RANGE FROM 1000-2000 J/K OVER A LARGE PORTION OF
THE EASTERN MOUNTAINS AND PLAINS. SEVERE THREAT LOOKS EVEN GREATER
THAN MON AS 0-6KM SHEAR INCREASES TO OVER 50 KTS...WITH
ENVIRONMENT LOOKING FAVORABLE FOR LARGE HAIL ACROSS THE PLAINS. OF
COURSE...MON NIGHT MCS AND ASSOCIATED COLD POOL WILL PLAY A LARGE
ROLE IN CONVECTIVE DEVELOPMENT TUE. MODELS SUGGEST FAIRLY LARGE
MCS THEN DROPS SOUTHWARD ALONG THE KS BORDER TUE NIGHT...AS STRONG
LLJ KEEPS CONVECTION GOING WELL INTO THE NIGHT. LITTLE CHANGE IN
THE PATTERN WED...WITH EARLY MORNING COLD POOL BEHIND DEPARTING
MCS...BEFORE ATMOSPHERE DESTABILIZES AGAIN OVER THE MOUNTAINS WED
AFTERNOON WITH STORMS MIGRATING ON TO THE PLAINS IN THE EVENING.
FOR THE WESTERN MOUNTAINS AND VALLEYS...TYPICAL SUMMER TIME
PATTERN WILL CONTINUE WITH AFTERNOON/EVENING CONVECTION EACH DAY
MON-WED...THOUGH STORM/RAINFALL INTENSITY WILL BE LESS HERE THAN
FARTHER EAST.
PERSISTENT NW FLOW ALOFT FINALLY BEGINS TO DRIVE SOME DRIER AIR
SOUTH ACROSS THE STATE FROM THU INTO NEXT WEEKEND...THOUGH WITH
SURFACE DEWPOINTS HOLDING IN THE 40S AND 50S OVER THE EASTERN
MOUNTAINS AND PLAINS...EXPECT TO HANG ON TO AT LEAST SOME MODEST
DIURNAL CONVECTION MANY AREAS THROUGH THE PERIOD.
TEMPERATURES WILL REMAIN NEAR SEASONAL AVERAGES MON...WITH SOME
COOLING BOTH TUE/WED AS HEIGHTS FALL AND RAIN COOLED AIR SPREADS
ACROSS THE REGION. GRADUALLY WARMING TREND THEN EXPECTED FROM THU
INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1122 AM MDT SUN JUL 13 2014
ANOTHER DAY WITH ABUNDANT LOW LEVEL MOISTURE...AND ANTICIPATE
AFTERNOON AND EARLY EVENING THUNDERSTORMS AT THE TAF SITES. MAIN
AVIATION THREATS FROM STORMS WILL GUSTY WINDS AND REDUCED CEILINGS
AND VISIBILITIES DUE TO HEAVY RAIN. MOST LIKELY PLACE TO GET
REDUCED FLIGHT RULES WILL BE KCOS. FOR TONIGHT...ANTICIPATE WEAK
DOWNSLOPE FLOW AT KCOS AND KPUB AND DO NOT EXPECT LOWER CEILINGS
DESPITE MOIST LOWER LEVELS. ON MONDAY...MORE OF THE SAME WITH
STORMS DEVELOPING BY EARLY AFTERNOON. --PGW--
&&
.HYDROLOGY...
ISSUED AT 410 AM MDT SUN JUL 13 2014
FLASH FLOOD POTENTIAL WILL REMAIN HIGH TDY THROUGH WED...WITH
POTENTIAL FOR STRONG STORMS PRODUCING HIGH RAINFALL RATES THROUGH
THE PERIOD. THREAT SHOULD GRADUALLY LESSEN BY THE END OF THE WEEK
AS AIR MASS SLOWLY DRYS OUT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ072>089-093-
094.
&&
$$
UPDATE...PGW
SHORT TERM...MW
LONG TERM...PETERSEN
AVIATION...PGW
HYDROLOGY...PETERSEN/MW
AREA FORECAST DISCUSSION
NWS TAUNTON MA
504 PM EDT SUN JUL 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL ACROSS THE REGION THROUGH WEDNESDAY
YIELDING PERIODS SHOWERS AND THUNDERSTORMS. A FEW STRONG TO SEVERE
THUNDERSTORMS APPEAR LIKELY OVER THIS TIME ALONG WITH A HEAVY
RAIN/LOCALIZED FLASH FLOOD THREAT. A TREND TOWARD DRIER AND
SOMEWHAT LESS HUMID WEATHER FOLLOWS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
JUST A FEW SHOWERS HAVE DEVELOPED ACROSS OUR FAR NORTHWEST ZONES AS
OF LATE AFTERNOON. ITS POSSIBLE WE SEE AN ISOLATED THUNDERSTORM OR
TWO ACROSS THE INTERIOR THROUGH EARLY THIS EVENING...BUT INSTABILITY
IS LIMITED.
THE MAIN CLUSTER OF SHOWERS/THUNDERSTORMS WAS BACK IN NEW YORK STATE
WITH AN ASSOCIATED SHORTWAVE. THE HRRR HAS BEEN CONSISTENT IN
BRINGING THIS ACTIVITY INTO OUR WESTERN ZONES AFTER 7 OR 8 PM. IT
DOES NOT LOOK LIKE IT WILL HAVE ENOUGH INSTABILITY/SHEAR FOR SEVERE
WEATHER. HOWEVER...A STRONG THUNDERSTORM OR TWO WITH LOCALLY GUSTY
WINDS CAN/T BE RULED OUT IN OUR FAR WESTERN ZONES THIS EVENING. IN
ADDITION...BRIEF HEAVY RAINFALL CERTAINLY POSSIBLE WITH PWATS AROUND
2 INCHES. WHILE ACTIVITY WILL BE WEAKENING AS IT ENTERS OUR
REGION...SOME MESOSCALE MODELS INDICATE AT LEAST SCATTERED SHOWERS
MAY TRY TO MAKE IT ONTO THE COASTAL PLAIN BY LATE EVENING OR AFTER
MIDNIGHT.
AFTER THE MAIN SHORTWAVE OR WHAT/S LEFT OF IT EXITS THE COASTAL
PLAIN...THERE STILL WILL BE THE RISK OF SCATTERED SHOWERS AND A FEW
THUNDERSTORMS THROUGH DAYBREAK. THIS A RESULT OF SOME ELEVATED
INSTABILITY AND A DEVELOPING LOW LEVEL JET. LOWS MAINLY IN THE UPPER
60S TO THE LOWER 70S AND IT WILL BE MUGGY. IN ADDITION...SOME
PATCHY FOG POSSIBLE LATE WITH BEST CHANCE CAPE AND ISLANDS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
***A FEW STRONG TO SEVERE THUNDERSTORMS LIKELY MONDAY AFTERNOON
AND/OR EVENING BUT LOW CONFIDENCE ON TIMING AND AREAL COVERAGE***
***HEAVY RAIN/LOCALIZED FLASH FLOOD THREAT INCREASES MONDAY NIGHT***
AN INTERESTING SET UP IN PLACE FOR SOUTHERN NEW ENGLAND MONDAY INTO
MONDAY NIGHT...BUT DETAILS/TIMING REMAIN UNCERTAIN. APPEARS THE
MAIN TRIGGER FOR CONVECTION MONDAY AFTERNOON/EVENING WILL BE A
SHORTWAVE THAT WILL LIFT NORTHEAST ACROSS SOUTHERN NEW ENGLAND. THE
MODELS SEEM TO BE STRUGGLING WITH TIMING OF THE SHORTWAVE/S AND
WHEN/WHERE TO TRIGGER CONVECTION.
SOME OF OUR GUIDANCE HOLDS OFF MOST OF THE CONVECTION UNTIL VERY
LATE MONDAY AFTERNOON OR EVENING...WHEN THE MAIN SHORTWAVE LIFTS
NORTHEAST AND GETS THINGS GOING CLOSE TO 00Z IN OUR WESTERN ZONES.
OTHER GUIDANCE SUCH AS THE NAM/GFS BREAKS OUT SCATTERED
SHOWERS/THUNDERSTORMS SOMEWHAT EARLIER. WE ARE DEALING WITH A VERY
MOIST/UNCAPPED ENVIRONMENT AND IT WON/T TAKE MUCH HEATING TO GET
SOME CONVECTION GOING. WE SEE THE POTENTIAL FOR SCATTERED
SHOWERS/THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EARLIER
THAN SOME OF THE OTHER GUIDANCE.
OTHER THAN THE TIMING ISSUES...THE BIG UNCERTAINTY THAT NEEDS TO BE
RESOLVED IS THE AMOUNT OF SOLAR INSULATION. GIVEN PATTERN...EXPECT
TO SEE A LOT OF CLOUDS AROUND BUT A FEW PEEKS OF SUN WILL PROBABLY
OCCUR. GIVEN THE FACT THAT WE WILL HAVE 70+ DEWPOINTS IN PLACE...WE
CAN GET AWAY WITH A LOT OF CLOUDS AND STILL HAVE A SEVERE
THREAT...BUT MORE SUN WILL CERTAINLY INCREASE POTENTIAL. LOOKS LIKE
WE SHOULD SEE 1000 TO 1500 J/KG OF CAPE DEVELOP...0 TO 6 KM SHEAR OF
25 TO 35 KNOTS AND PERHAPS LOCALLY OVER 40 KNOTS WHEN THE MAIN
SHORTWAVE KICKS OUT...AND 70+ DEWPOINTS.
ALL IN ALL...DEEP LOW LEVEL MOISTURE/INSTABILITY AND ADEQUATE SHEAR
SUPPORT THE THREAT FOR A FEW STRONG TO SEVERE THUNDERSTORMS DURING
THE AFTERNOON AND/OR EVENING. PERHAPS THE HIGHEST POTENTIAL ENDS UP
IN OUR SOUTHWEST ZONES...WHERE BETTER INSTABILITY/SHEAR
OVERLAP...BUT CAN/T RULE OUT A FEW STRONG TO SEVERE STORMS ANYWHERE.
THE MAIN THREAT WOULD BE LOCALLY STRONG TO DAMAGING WIND GUSTS WITH
A SECONDARY CONCERN FOR HAIL WITH ANY DISCRETE CELLS. IN
ADDITION...0 TO 1 KM HELICITY VALUES MAY EXCEED 100 ESPECIALLY
DURING THE LATE AFTERNOON AND EVENING. THIS COMBINED WITH AN
INCREASING LOW LEVEL JET/70+ DEWPOINTS AND LOW LCL/S...AN ISOLATED
WEAK TORNADO IS CERTAINLY POSSIBLE.
IT APPEARS THAT HEAVY RAIN/LOCALIZED FLASH FLOOD POTENTIAL WILL
INCREASE MONDAY NIGHT AS LOW LEVEL JET INTENSIFIES. INDICATIONS ARE
THAT THE SHOWERS/THUNDERSTORMS WILL BE COME MORE WIDESPREAD. PWATS
ARE QUITE IMPRESSIVE AT 2+ INCHES ACROSS MUCH OF THE REGION. A
FLASH FLOOD WATCH MAY BE NEEDED IN THE NEXT 12 TO 24 HOURS...BUT
THOUGH THERE IS MORE TIME TO GET A BETTER FEEL ON THE LOCATION.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HIGHLIGHTS...
* NUMEROUS SHOWERS & THUNDERSTORMS TUESDAY INTO WEDNESDAY WITH HEAVY
RAIN AND FLASH FLOOD POTENTIAL
* SOME THUNDERSTORMS MAY PRODUCE LOCALLY STRONG TO DAMAGING WINDS ON
TUESDAY
* WARM AND VERY HUMID TUESDAY
* IMPROVING WEATHER WITH DRIER AND LESS HUMID CONDITIONS LATE THIS
WEEK
HIGH AMPLITUDE MID AND UPPER LEVEL PATTERN CONTINUES TO TAKE SHAPE
FROM THE WESTERN ATLANTIC TO THE EASTERN PACIFIC...WITH AN ANOMALOUS
TROUGH/CUTOFF COLD POOL MOVING INTO THE GREAT LAKES EARLY THIS WEEK.
AS THIS TROUGH EVOLVES INTO THE LONG RANGE TIMEFRAME AND SHIFTS
SLOWLY SE...SURFACE WAVES AND TROUGHS WILL SLOWLY MOVE IN THE
DEVELOPING SW FLOW AT THE SURFACE AND ALOFT. THE SW FLOW WILL
CONTINUE TO PUSH TROPICAL AIR ACROSS THE REGION ALONG WITH PWATS
REMAINING IN THE 2.1 TO 2.2 INCH RANGE TUESDAY INTO WEDNESDAY. ALL
THIS...ALONG WITH THE SW FLOW IN PLACE...CONTINUES TO SIGNAL THE
POTENTIAL FOR FLASH FLOODING AS CELLS TRAIN ACROSS THE REGION. HAVE
QPF OF 1 TO 2 INCHES BETWEEN 12Z TUE AND 00Z THU IN THE FORECAST...
BUT THAT IS AERIAL COVERAGE. MAY SEE HIGHER AMOUNTS IN LOCALLY
HEAVIER SHOWERS/TSTMS.
12Z MODEL CYCLE SHOWING GOOD AGREEMENT IN VERY SLOW PROGRESSION OF
THE FRONT TUE NIGHT INTO WED MORNING AS LOW PRES WAVE MOVES ALONG
THE FRONT LYING ACROSS THE REGION. NOTING RR QUADRANT OF 120 KT H3
JET PASSING ACROSS THE REGION LATE TUE INTO WED...ALONG WITH GOOD
INSTABILITY IN PLACE ESPECIALLY TUESDAY AFTERNOON/EVENING WITH
SBCAPES AROUND 1000-1500 J/KG...AND EVEN 0-1 KM HELICITIES UP TO
AROUND 100 /M2. WILL SEE CONTINUED CHANCE FOR STRONG TO SEVERE
THUNDERSTORMS DURING TUESDAY INTO TUESDAY EVENING. MAY ALSO SEE HAIL
AND...AGAIN...CAN NOT RULE OUT A POSSIBLE SPINUP. HOWEVER...THE ONLY
LIMITING FACTOR WILL BE SOLAR INSULATION...AS THERE WILL BE A LOT OF
CLOUDS AROUND. SPC HAS PLACED PORTIONS OF THE REGION INTO A SLIGHT
RISK OF SEVERE STORMS.
MODELS NOW IN GOOD AGREEMENT IN SLOWLY PUSHING THE FRONT E DURING
WEDNESDAY AS THE H5 TROUGH DEAMPLIFIES. SOME INSTABILITY WILL LINGER
ACROSS EASTERN AREAS SO HAVE KEPT MENTION OF TSTMS IN THE FORECAST
THERE THROUGH MOST OF WEDNESDAY...AND THERE WILL STILL BE SOME HEAVY
RAINERS AS DEWPTS REMAIN IN THE MID-UPPER 60S. SHOULD SEE IMPROVING
CONDITIONS WED NIGHT.
MODELS AND ENSEMBLES CONTINUE TO SIGNAL DRIER CONDITIONS WITH LOWER
HUMIDITIES ON THURSDAY AND FRIDAY AS HIGH PRES RIDGE BUILDS ACROSS
THE REGION. EXPECT DAYTIME HIGHS TO RUN CLOSE TO OR JUST SLIGHTLY
BELOW SEASONAL NORMALS.
AS FOR NEXT WEEKEND...SOME TIMING ISSUES WITH A POSSIBLE TRAILING H5
SHORT WAVE TRYING TO APPROACH LATE SAT OR SUN. HAVE KEPT ONLY SLIGHT
CHANCE POPS GOING FOR THIS POSSIBLE FEATURE...THOUGH LOOKS LIKE THE
HIGH SHOULD KEEP DRY CONDITIONS IN PLACE...FOR NOW.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...
THIS AFTERNOON...HIGH CONFIDENCE. MAINLY VFR WITH SOUTHWEST WIND
GUSTS UP TO 25 KNOTS. HOWEVER...SOME MARGINAL MVFR CIGS WILL
CONTINUE TO AFFECT THE INTERIOR.
TONIGHT...MODERATE CONFIDENCE. CLUSTER OF WEAKENING SHOWERS AND A
FEW THUNDERSTORMS WILL WORK ACROSS THE REGION BETWEEN 0Z AND 6Z.
WHILE SOME SHOWERS MAY AFFECT THE COASTAL PLAIN...BEST SHOT FOR
THUNDER WILL BE ACROSS OUR WESTERN ZONES. CAN/T EVEN RULE OUT
LOCALLY GUSTY WINDS IN OUR FAR WESTERN ZONES. OTHERWISE...SCT
SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN POSSIBLE BETWEEN 6Z AND
12Z.
MAIN UNCERTAINTY TONIGHT IS HOW MUCH LOW CLOUDS AND PATCHY FOG WILL
DEVELOP. WILL KEEP THINGS MORE OPTIMISTIC FOR NOW AND SHOW JUST
MVFR CONDITIONS DEVELOPING OVERNIGHT IN OUR WESTERN AND SOUTHERN
ZONES...EXCEPT IFR CONDITIONS ARE POSSIBLE ACROSS THE CAPE/ISLANDS.
TUESDAY AND TUESDAY NIGHT....MODERATE CONFIDENCE. LOW CONFIDENCE ON
TIMING...BUT SCATTERED SHOWERS/THUNDERSTORMS EXPECTED PARTICULARLY
TUE AFTERNOON AND NIGHT. A FEW OF THE STORMS WILL LIKELY BE STRONG
TO SEVERE...POSSIBLE ANYWHERE BUT BEST SHOT MAY BE IN OUR WESTERN
AND SOUTHERN ZONES. BIGGEST THREATS TORRENTIAL RAINFALL AND
LOCALLY STRONG TO DAMAGING WINDS. AS FOR SKY/VSBYS OUTSIDE OF
PRECIPITATION VFR CONDITIONS DOMINATE DURING THE DAY TUE EXCEPT
LOWER CONDITIONS MAINLY NEAR SOUTH COAST. CIGS/VSBYS WILL DETERIORATE
FROM SOUTH TO NORTH TUE NIGHT WITH MAINLY MVFR TO IFR DEVELOPING
FROM SOUTH TO NORTH.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF. LOW PROB OF AN ISOLATED
THUNDERSTORM MAINLY BETWEEN 02Z AND 06Z.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY...MODERATE TO HIGH CONFIDENCE. EXPECT SHOWERS WITH SCT TO
NUMEROUS TSTMS. HEAVY DOWNPOURS LIKELY. WILL SEE AREAS OF MVFR-IFR
CONDITIONS IN HEAVIER PRECIP. SOME GUSTY WINDS IN TSTMS LIKELY TUE
AFTERNOON/EVENING. PATCHY FOG DEVELOPING TUE NIGHT WITH MVFR-IFR
CONDITIONS MAINLY ACROSS CENTRAL-E MA/RI. IMPROVING CONDITIONS
ACROSS CT VALLEY TUE EVENING.
WEDNESDAY...MODERATE CONFIDENCE MAINLY FOR TIMING. MVFR-IFR
CONDITIONS EARLY WED. SHOULD SEE CONDITIONS IMPROVE TO VFR BY MIDDAY
ACROSS CT VALLEY AND SLOWLY PUSHING E DURING THE AFTERNOON. MVFR MAY
LINGER INTO WED EVENING ACROSS E MA/RI. PATCHY FOG MAY DEVELOP IN
NORMALLY PRONE AREAS WITH MVFR-IFR CIGS/VSBYS.
THURSDAY...MODERATE CONFIDENCE. ANY LEFTOVER MVFR-IFR CIGS/VSBYS
ACROSS E MA SHOULD IMPROVE BY MIDDAY. OTHERWISE...VFR.
FRIDAY...MODERATE TO HIGH CONFIDENCE. VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...
SOUTHWEST WIND GUSTS OF 25 KNOTS WILL CONTINUE ACROSS MANY OF THE
NEAR SHORE WATERS INTO THE FIRST PART OF THE NIGHT. IN
ADDITION...LONG SOUTHWEST FETCH MAY BUILD SEAS TO AROUND 5 FEET
ACROSS THE OUTER-WATERS. THEREFORE...SCA HEADLINES REMAIN IN PLACE.
MAY HAVE SOME FOG DEVELOP LATE TONIGHT.
MONDAY AND MONDAY NIGHT...
SOUTHWEST WIND GUSTS NOT QUITE AS STRONG ON MONDAY...BUT STILL
EXPECT THEM TO GUST TO AROUND 20 KNOTS. THEREFORE...DO NOT THINK
WILL NEED NEAR SHORE SCA HEADLINES. ACROSS THE OUTER-WATERS...SEAS
MAY BRIEFLY DIMINISH BELOW 5 FEET BUT SHOULD INCREASE AGAIN MONDAY
NIGHT. THEREFORE...OPTED TO JUST EXTEND THOSE SCA HEADLINES THROUGH
THE NIGHT.
MAY HAVE A FEW STRONG TO SEVERE THUNDERSTORMS MONDAY AFTERNOON AND
NIGHT. IN ADDITION...MORE FOG MAY DEVELOP MONDAY NIGHT.
OUTLOOK...TUESDAY THROUGH FRIDAY...
TUESDAY...MODERATE TO HIGH CONFIDENCE. EXPECT S-SW WINDS TO CONTINUE
THROUGH TUE NIGHT...WITH SOME GUSTS TO 25 KT. SEAS ON THE OPEN
WATERS UP TO 5-6 FT. SHOWERS/SCT TSTMS WITH VERY HEAVY DOWNPOURS AND
REDUCED VSBYS. LOW CHANCE OF STRONG WIND GUSTS IN ANY TSTMS. VSBYS
ALSO REDUCED IN PATCHY FOG TUE NIGHT.
WEDNESDAY...MODERATE CONFIDENCE MAINLY FOR TIMING. COLD FRONT SLOWLY
CROSSES THE WATERS. S-SW WINDS CONTINUE TO GUST TO 20 KT. SEAS
REMAIN AOA 5 FT ON THE OPEN WATERS. STILL EXPECT HEAVY SHOWERS/SCT
TSTMS AND PATCHY FOG REDUCING VSBYS. WILL SEE IMPROVEMENT FROM W-E
WED NIGHT...BUT SHOWERS AND PATCHY FOG LINGERS ON THE EASTERN WATERS
THROUGH LATE WED NIGHT.
THURSDAY AND FRIDAY...MODERATE TO HIGH CONFIDENCE. EXPECT IMPROVING
CONDITIONS ON THE EASTERN WATERS EARLY THU...OTHERWISE GOOD VSBYS. W
TO NW WINDS DIMINISHING...BUT SEAS MAY LINGER AT AROUND 5 FT ON THE
OUTER WATERS THU...WHICH SHOULD SUBSIDE THU NIGHT. WILL SEE LIGHT S
TO SW WINDS FRIDAY.
&&
.TIDES/COASTAL FLOODING...
VERY HIGH ASTRONOMICAL HIGH TIDES WITH BOSTON AT 12.2 FEET AROUND
MIDNIGHT TONIGHT. HOWEVER...SOUTH TO SOUTHWEST WINDS WILL PREVENT
ANY PROBLEMS ALONG THE EASTERN MA COAST. ALONG THE SOUTH
COAST...WINDS WILL NOT BE STRONG ENOUGH TO CAUSE ANY ISSUES. NO
COASTAL PRODUCTS ARE ANTICIPATED. WORST CASE SCENARIO IS VERY
MINOR SPLASH OVER WITH NO REAL IMPACTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ231>234-251.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ230-
236.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ250.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
TUESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...FRANK/EVT
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...EVT
AVIATION...FRANK/EVT
MARINE...FRANK/EVT
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
406 PM EDT SUN JUL 13 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL IN THE VICINITY OF THE REGION THROUGH
WEDNESDAY YIELDING PERIODS SHOWERS AND THUNDERSTORMS. A FEW STRONG
TO SEVERE THUNDERSTORMS APPEAR LIKELY OVER THIS TIME ALONG WITH A
HEAVY RAIN/LOCALIZED FLASH FLOOD THREAT. A TREND TOWARD DRIER AND
SOMEWHAT LESS HUMID WEATHER FOLLOWS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
JUST A FEW SHOWERS HAVE DEVELOPED ACROSS OUR FAR NORTHWEST ZONES AS
OF LATE AFTERNOON. ITS POSSIBLE WE SEE AN ISOLATED THUNDERSTORM OR
TWO ACROSS THE INTERIOR THROUGH EARLY THIS EVENING...BUT INSTABILITY
IS LIMITED.
THE MAIN CLUSTER OF SHOWERS/THUNDERSTORMS WAS BACK IN NEW YORK STATE
WITH AN ASSOCIATED SHORTWAVE. THE HRRR HAS BEEN CONSISTENT IN
BRINGING THIS ACTIVITY INTO OUR WESTERN ZONES AFTER 7 OR 8 PM. IT
DOES NOT LOOK LIKE IT WILL HAVE ENOUGH INSTABILITY/SHEAR FOR SEVERE
WEATHER. HOWEVER...A STRONG THUNDERSTORM OR TWO WITH LOCALLY GUSTY
WINDS CAN/T BE RULED OUT IN OUR FAR WESTERN ZONES THIS EVENING. IN
ADDITION...BRIEF HEAVY RAINFALL CERTAINLY POSSIBLE WITH PWATS AROUND
2 INCHES. WHILE ACTIVITY WILL BE WEAKENING AS IT ENTERS OUR
REGION...SOME MESOSCALE MODELS INDICATE AT LEAST SCATTERED SHOWERS
MAY TRY TO MAKE IT ONTO THE COASTAL PLAIN BY LATE EVENING OR AFTER
MIDNIGHT.
AFTER THE MAIN SHORTWAVE OR WHAT/S LEFT OF IT EXITS THE COASTAL
PLAIN...THERE STILL WILL BE THE RISK OF SCATTERED SHOWERS AND A FEW
THUNDERSTORMS THROUGH DAYBREAK. THIS A RESULT OF SOME ELEVATED
INSTABILITY AND A DEVELOPING LOW LEVEL JET. LOWS MAINLY IN THE UPPER
60S TO THE LOWER 70S AND IT WILL BE MUGGY. IN ADDITION...SOME
PATCHY FOG POSSIBLE LATE WITH BEST CHANCE CAPE AND ISLANDS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
***A FEW STRONG TO SEVERE THUNDERSTORMS LIKELY MONDAY AFTERNOON
AND/OR EVENING BUT LOW CONFIDENCE ON TIMING AND AREAL COVERAGE***
***HEAVY RAIN/LOCALIZED FLASH FLOOD THREAT INCREASES MONDAY NIGHT***
AN INTERESTING SET UP IN PLACE FOR SOUTHERN NEW ENGLAND MONDAY INTO
MONDAY NIGHT...BUT DETAILS/TIMING REMAIN UNCERTAIN. APPEARS THE
MAIN TRIGGER FOR CONVECTION MONDAY AFTERNOON/EVENING WILL BE A
SHORTWAVE THAT WILL LIFT NORTHEAST ACROSS SOUTHERN NEW ENGLAND. THE
MODELS SEEM TO BE STRUGGLING WITH TIMING OF THE SHORTWAVE/S AND
WHEN/WHERE TO TRIGGER CONVECTION.
SOME OF OUR GUIDANCE HOLDS OFF MOST OF THE CONVECTION UNTIL VERY
LATE MONDAY AFTERNOON OR EVENING...WHEN THE MAIN SHORTWAVE LIFTS
NORTHEAST AND GETS THINGS GOING CLOSE TO 00Z IN OUR WESTERN ZONES.
OTHER GUIDANCE SUCH AS THE NAM/GFS BREAKS OUT SCATTERED
SHOWERS/THUNDERSTORMS SOMEWHAT EARLIER. WE ARE DEALING WITH A VERY
MOIST/UNCAPPED ENVIRONMENT AND IT WON/T TAKE MUCH HEATING TO GET
SOME CONVECTION GOING. WE SEE THE POTENTIAL FOR SCATTERED
SHOWERS/THUNDERSTORMS DEVELOPING DURING THE AFTERNOON AND EARLIER
THAN SOME OF THE OTHER GUIDANCE.
OTHER THAN THE TIMING ISSUES...THE BIG UNCERTAINTY THAT NEEDS TO BE
RESOLVED IS THE AMOUNT OF SOLAR INSULATION. GIVEN PATTERN...EXPECT
TO SEE A LOT OF CLOUDS AROUND BUT A FEW PEEKS OF SUN WILL PROBABLY
OCCUR. GIVEN THE FACT THAT WE WILL HAVE 70+ DEWPOINTS IN PLACE...WE
CAN GET AWAY WITH A LOT OF CLOUDS AND STILL HAVE A SEVERE
THREAT...BUT MORE SUN WILL CERTAINLY INCREASE POTENTIAL. LOOKS LIKE
WE SHOULD SEE 1000 TO 1500 J/KG OF CAPE DEVELOP...0 TO 6 KM SHEAR OF
25 TO 35 KNOTS AND PERHAPS LOCALLY OVER 40 KNOTS WHEN THE MAIN
SHORTWAVE KICKS OUT...AND 70+ DEWPOINTS.
ALL IN ALL...DEEP LOW LEVEL MOISTURE/INSTABILITY AND ADEQUATE SHEAR
SUPPORT THE THREAT FOR A FEW STRONG TO SEVERE THUNDERSTORMS DURING
THE AFTERNOON AND/OR EVENING. PERHAPS THE HIGHEST POTENTIAL ENDS UP
IN OUR SOUTHWEST ZONES...WHERE BETTER INSTABILITY/SHEAR
OVERLAP...BUT CAN/T RULE OUT A FEW STRONG TO SEVERE STORMS ANYWHERE.
THE MAIN THREAT WOULD BE LOCALLY STRONG TO DAMAGING WIND GUSTS WITH
A SECONDARY CONCERN FOR HAIL WITH ANY DISCRETE CELLS. IN
ADDITION...0 TO 1 KM HELICITY VALUES MAY EXCEED 100 ESPECIALLY
DURING THE LATE AFTERNOON AND EVENING. THIS COMBINED WITH AN
INCREASING LOW LEVEL JET/70+ DEWPOINTS AND LOW LCL/S...AN ISOLATED
WEAK TORNADO IS CERTAINLY POSSIBLE.
IT APPEARS THAT HEAVY RAIN/LOCALIZED FLASH FLOOD POTENTIAL WILL
INCREASE MONDAY NIGHT AS LOW LEVEL JET INTENSIFIES. INDICATIONS ARE
THAT THE SHOWERS/THUNDERSTORMS WILL BE COME MORE WIDESPREAD. PWATS
ARE QUITE IMPRESSIVE AT 2+ INCHES ACROSS MUCH OF THE REGION. A
FLASH FLOOD WATCH MAY BE NEEDED IN THE NEXT 12 TO 24 HOURS...BUT
THOUGH THERE IS MORE TIME TO GET A BETTER FEEL ON THE LOCATION.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* NUMEROUS SHOWERS & THUNDERSTORMS TUE INTO WED WITH HEAVY RAIN AND
ISOLATED FLASH FLOOD POTENTIAL
* WARM AND VERY HUMID MON NIGHT AND TUESDAY
* IMPROVING WEATHER WITH DRIER AND LESS HUMID CONDITIONS THU AND FRI
ENSEMBLES AND DETERMINISTIC GUIDANCE CONTINUE TO SUPPORT A HIGH
AMPLITUDE PATTERN ACROSS NORTH AMERICA WITH AN ANOMALOUS TROUGH OF
-3 SD /500 MB HEIGHTS/ DIVING INTO THE GREAT LAKES MON. THIS TROUGH
WILL BE SLOW MOVING AS DOWNSTREAM RIDGING DEVELOPS OVER THE
NORTHWEST ATLC. THE SLOW MOVEMENT OF THIS TROUGH WILL RESULT IN A
STALLED FRONTAL BOUNDARY ACROSS NEW ENGLAND FROM SUN NIGHT INTO
WED. THE HIGH AMPLITUDE PATTERN ALSO RESULTS IN MERIDIONAL FLOW ALONG
THE EASTERN SEABOARD WITH PWATS UP TO +2 SD STREAMING POLEWARD INTO
NEW ENGLAND FROM SUN NIGHT INTO WED. THIS DURATION COUPLED WITH DEEP
UNIDIRECTIONAL FLOW WILL PROVIDE AN ENVIRONMENT FAVORABLE FOR BACK
BUILDING AND TRAINING CELLS. THUS A RISK FOR ISOLATED FLASH
FLOODING. BOTH 00Z EC AND GFS CONTINUE TO OFFER HEAVY QPF WITH 1-3"
ACROSS THE REGION FROM TONIGHT THRU WED. 00Z GEFS ENSEMBLES NOT AS
BULLISH WITH VERY LOW PROBS OF 2+ INCHES.
IN ADDITION...THIS HIGH AMPLITUDE PATTERN YIELDS AN ANOMALOUS /+2
SD/ UPPER LEVEL JET STREAK ACROSS THE NORTHEAST AND SOUTHEAST
CANADA. THESE STRONG WIND FIELDS COUPLED WITH MODEST INSTABILITY
WILL PROVIDE A LOW RISK OF A FEW STRONG TSTMS.
AS FOR GUIDANCE ASSESSMENT...THE 00Z GFS AND GEFS HAS FINALLY COME
AROUND TO THE SLOWER SOLUTIONS OF THE ECMWF AND ECENS. THE HIGHER
RES OPERATIONAL RUNS OF THE ECMWF AND GFS ARE IN GOOD AGREEMENT THAT
A WAVE WILL TRACK UP THE FRONT TUE NIGHT INTO WED. THIS WILL SLOW
THE FRONT/S DEPARTURE AND LIKELY KEEP SHOWERS/TSTMS IN THE FORECAST
AT LEAST THRU EARLY WED. THIS FRONTAL WAVE WILL ALSO ENHANCE THE
RISK FOR HEAVY RAIN AND ASSOCIATED FLASH FLOODING. MODELS THEN MOVE
THE FRONT OFFSHORE LATE WED/WED NIGHT ALONG WITH MID/UPPER LEVEL
TROUGH DEAMPLIFYING. THIS SUPPORTS A TREND TOWARD DRIER AND LESS
HUMID WEATHER THU AND FRI.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY NIGHT/...
THIS AFTERNOON...HIGH CONFIDENCE. MAINLY VFR WITH SOUTHWEST WIND
GUSTS UP TO 25 KNOTS. HOWEVER...SOME MARGINAL MVFR CIGS WILL
CONTINUE TO AFFECT THE INTERIOR.
TONIGHT...MODERATE CONFIDENCE. CLUSTER OF WEAKENING SHOWERS AND A
FEW THUNDERSTORMS WILL WORK ACROSS THE REGION BETWEEN 0Z AND 6Z.
WHILE SOME SHOWERS MAY AFFECT THE COASTAL PLAIN...BEST SHOT FOR
THUNDER WILL BE ACROSS OUR WESTERN ZONES. CAN/T EVEN RULE OUT
LOCALLY GUSTY WINDS IN OUR FAR WESTERN ZONES. OTHERWISE...SCT
SHOWERS AND A FEW THUNDERSTORMS WILL REMAIN POSSIBLE BETWEEN 6Z AND
12Z.
MAIN UNCERTAINTY TONIGHT IS HOW MUCH LOW CLOUDS AND PATCHY FOG WILL
DEVELOP. WILL KEEP THINGS MORE OPTIMISTIC FOR NOW AND SHOW JUST
MVFR CONDITIONS DEVELOPING OVERNIGHT IN OUR WESTERN AND SOUTHERN
ZONES...EXCEPT IFR CONDITIONS ARE POSSIBLE ACROSS THE CAPE/ISLANDS.
TUESDAY AND TUESDAY NIGHT....MODERATE CONFIDENCE. LOW CONFIDENCE ON
TIMING...BUT SCATTERED SHOWERS/THUNDERSTORMS EXPECTED PARTICULARLY
TUE AFTERNOON AND NIGHT. A FEW OF THE STORMS WILL LIKELY BE STRONG
TO SEVERE...POSSIBLE ANYWHERE BUT BEST SHOT MAY BE IN OUR WESTERN
AND SOUTHERN ZONES. BIGGEST THREATS TORRENTIAL RAINFALL AND
LOCALLY STRONG TO DAMAGING WINDS. AS FOR SKY/VSBYS OUTSIDE OF
PRECIPITATION VFR CONDITIONS DOMINATE DURING THE DAY TUE EXCEPT
LOWER CONDITIONS MAINLY NEAR SOUTH COAST. CIGS/VSBYS WILL DETERIORATE
FROM SOUTH TO NORTH TUE NIGHT WITH MAINLY MVFR TO IFR DEVELOPING
FROM SOUTH TO NORTH.
KBOS TAF...MODERATE CONFIDENCE IN TAF.
KBDL TAF...MODERATE CONFIDENCE IN TAF. LOW PROB OF AN ISOLATED
THUNDERSTORM MAINLY BETWEEN 02Z AND 06Z.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT AND TUESDAY...NUMEROUS SHOWERS AND SCATTERED TSTMS WITH
HEAVY DOWNPOURS LIKELY. PATCHY FOG AT NIGHT LIKELY YIELDING MVFR/IFR
CONDITIONS...THEN LIFTING TO MARGINAL VFR DURING THE LATE MORNING
AND AFTERNOON. MODERATE TO HIGH CONFIDENCE.
WEDNESDAY...IFR/MVFR EASTERN MA AND RI WITH VFR/MVFR WESTERN CT/MA.
GREATEST RISK OF SHOWER/TSTMS AND PATCHY FOG ACROSS RI AND EASTERN
MA. MODERATE CONFIDENCE.
THURSDAY...TREND TOWARD VFR ALONG WITH DRY WEATHER. MODERATE
CONFIDENCE.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...
SOUTHWEST WIND GUSTS OF 25 KNOTS WILL CONTINUE ACROSS MANY OF THE
NEAR SHORE WATERS INTO THE FIRST PART OF THE NIGHT. IN
ADDITION...LONG SOUTHWEST FETCH MAY BUILD SEAS TO AROUND 5 FEET
ACROSS THE OUTER-WATERS. THEREFORE...SCA HEADLINES REMAIN IN PLACE.
MAY HAVE SOME FOG DEVELOP LATE TONIGHT.
MONDAY AND MONDAY NIGHT...
SOUTHWEST WIND GUSTS NOT QUITE AS STRONG ON MONDAY...BUT STILL
EXPECT THEM TO GUST TO AROUND 20 KNOTS. THEREFORE...DO NOT THINK
WILL NEED NEAR SHORE SCA HEADLINES. ACROSS THE OUTER-WATERS...SEAS
MAY BRIEFLY DIMINISH BELOW 5 FEET BUT SHOULD INCREASE AGAIN MONDAY
NIGHT. THEREFORE...OPTED TO JUST EXTEND THOSE SCA HEADLINES THROUGH
THE NIGHT.
MAY HAVE A FEW STRONG TO SEVERE THUNDERSTORMS MONDAY AFTERNOON AND
NIGHT. IN ADDITION...MORE FOG MAY DEVELOP MONDAY NIGHT.
OUTLOOK...TUESDAY THROUGH THURSDAY...
TUESDAY...COLD FRONT REMAINS WEST OF NEW ENGLAND WATERS. THUS SSW
WINDS 15-20 KT CONTINUES WITH GUSTS UP TO 25 KT POSSIBLE. SCATTERED
TSTMS WITH TORRENTIAL DOWNPOURS. LOW RISK OF A TSTM WITH STRONG
WINDS. VSBY REDUCED AT TIMES IN PATCHY FOG. MODERATE TO HIGH
FORECAST CONFIDENCE.
WEDNESDAY...TRANSITION DAY WITH FRONT SLOWLY MOVING ACROSS NEW
ENGLAND AND THE COASTAL WATERS. HEAVY SHOWERS AND SCATTERED TSTMS
CONTINUE ALONG WITH PATCHY MORNING FOG. HOWEVER COULD SEE SOME
IMPROVEMENT LATE IN THE DAY AND ESPECIALLY AT NIGHT AS FRONT
CONTINUES TO MOVE EAST. SSW WINDS 15-20 KT WILL SLACKEN AND BECOME
WSW LATE OR AT NIGHT. MODERATE CONFIDENCE.
THURSDAY...BIG IMPROVEMENT WITH DRIER WEATHER AND IMPROVING VSBY.
FAIRLY LIGHT WINDS EXPECTED.
&&
.TIDES/COASTAL FLOODING...
VERY HIGH ASTRONOMICAL HIGH TIDES WITH BOSTON AT 12.2 FEET AROUND
MIDNIGHT TONIGHT. HOWEVER...SOUTH TO SOUTHWEST WINDS WILL PREVENT
ANY PROBLEMS ALONG THE EASTERN MA COAST. ALONG THE SOUTH
COAST...WINDS WILL NOT BE STRONG ENOUGH TO CAUSE ANY ISSUES. NO
COASTAL PRODUCTS ARE ANTICIPATED OVER THE NEXT 36 HOURS. WORST CASE
SCENARIO IS VERY MINOR SPLASH OVER WITH NO REAL IMPACTS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT MONDAY FOR ANZ231>234-251.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ230-
236.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT MONDAY FOR ANZ235-237.
SMALL CRAFT ADVISORY UNTIL 8 AM EDT TUESDAY FOR ANZ250.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 8 AM EDT
TUESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...FRANK
NEAR TERM...FRANK
SHORT TERM...FRANK
LONG TERM...NOCERA
AVIATION...FRANK/NOCERA
MARINE...FRANK/NOCERA
TIDES/COASTAL FLOODING...STAFF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1131 AM MDT SUN JUL 13 2014
.SHORT TERM...(TODAY THROUGH TUESDAY NIGHT)
ISSUED AT 243 AM MDT SUN JUL 13 2014
UPPER FLOW WILL BE NORTHWEST FROM TODAY THROUGH TUESDAY NIGHT. A
SURFACE FRONT WILL MOVE SOUTH INTO NORTHWEST KANSAS LATE THIS
AFTERNOON/EARLY THIS EVENING. HIGH PRESSURE WILL MOVE INTO THE
PLAINS SUNDAY NIGHT AND MONDAY AND PERSIST THROUGH TUESDAY NIGHT.
EARLY THIS MORNING LIGHT SHOWERS CONTINUE OVER THE SOUTHWEST CORNER
OF THE FA. THE HRRR INDICATES THAT THESE SHOWERS SHOULD DISSIPATE
BY 14 OR 15Z. PLAN TO INCLUDE SCATTERED SHOWERS IN THE GRIDS AND
ZONES FOR THESE.
FOR TODAY AND TONIGHT A WEAK FRONT APPROACHES THE NORTHERN FA BY
LATE AFTERNOON. THERE IS A WEAK SHORTWAVE IN THE FLOW AS WELL WHICH
SHOULD SUPPORT LOW CHANCES OF STORMS. CHANCE POPS WILL FOLLOW THE
FRONT SOUTH ACROSS THE FA TONIGHT.
THE GFS AND NAM HAVE DIFFERENCES WITH THE AMOUNT OF FORCING FOR
MONDAY/MONDAY NIGHT. THE NAM DOES NOT INDICATE ANY FORCING UNTIL
AFTER 06Z TUESDAY. THE GFS SHOWS VERY WEAK FORCING FOR MONDAY WITH
A LACK OF FORCING MONDAY NIGHT. AS A RESULT, CONFIDENCE IS LOW SO
WILL KEEP POPS LOW. THE BEST CHANCE OF THUNDERSTORMS WILL BE OVER
EASTERN COLORADO.
TUESDAY/TUESDAY NIGHT GOOD MOISTURE AND FORCING COME TOGETHER OVER
THE FA. INSTABILITY DROPS OFF FOR THIS EVENT SO SHOWERS WITH
ISOLATED THUNDER WILL BE THE PREDOMINANT TYPE OF WEATHER OTHER THAN
TUESDAY AFTERNOON/EVENING IN THE WEST WHERE THERE WILL BE GREATER
INSTABILITY.
MAX TEMPERATURES TODAY AND MONDAY WILL RISE TO THE MID AND UPPER
80S. MUCH COOLER READINGS WILL OCCUR ON TUESDAY WITH MAX
TEMPERATURES AROUND 70. MIN TEMPERATURES WILL COOL TO THE LOWER TO
MID 60S TONIGHT. MIN TEMPERATURES MONDAY AND TUESDAY NIGHTS WILL BE
IN THE MID AND UPPER 50S.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 220 AM MDT SUN JUL 13 2014
WEDNESDAY...AN UPPER LEVEL SHORTWAVE TROUGH WILL SHIFT ACROSS THE
HIGH PLAINS REGION WEDNESDAY...WHICH LOOKS TO BE THE LAST BIT OF
ENERGY ASSOCIATED WITH THE MAIN UPPER LEVEL LOW CENTER OVER THE
EASTERN THIRD OF THE CONUS. THE POSITION OF THE SURFACE HIGH
PRESSURE SYSTEM ON WEDNESDAY WILL FUNNEL LOTS OF MOISTURE INTO THE
AREA...WITH ALL GUIDANCE SUGGESTING AT LEAST SOME CHANCES FOR
PRECIPITATION ACROSS MUCH OF THE AREA. INSTABILITY ALOFT SHOULD
REMAIN OVER EASTERN COLORADO...BUT CANNOT RULE OUT SOME ISOLATED
THUNDERSHOWERS OVER THE REST OF THE AREA WEDNESDAY. DUE TO CLOUD
COVER...RAINFALL AND ALREADY COOLER CANADIAN AIR...HIGH TEMPERATURES
WILL BE 15 TO 20 DEGREES BELOW NORMAL IN THE UPPER 60S TO LOWER
70S...WITH SOME GUIDANCE SUGGESTING TEMPERATURES COULD BE EVEN A BIT
LOWER.
THURSDAY/FRIDAY...A SHORTWAVE RIDGE WILL BEGIN MOVING OVER THE
FORECAST AREA FOR THURSDAY AND FRIDAY. SOME LINGERING CHANCES FOR
THUNDERSHOWERS WILL REMAIN FOR THE REGION ON THURSDAY AS THE SURFACE
CONVERGENCE ZONE SHIFTS SOUTHWARD WITH THE EXITING HIGH PRESSURE
SYSTEM TO THE EAST. WINDS WILL SHIFT AND BRING IN MORE DRY AIR ALOFT
ON FRIDAY...WHICH SHOULD KEEP CONDITIONS DRY FOR MOST OF THE AREA.
CHANCES FOR AFTERNOON THUNDERSTORMS IN EASTERN COLORADO ARE POSSIBLE
ALONG SURFACE TROUGH AND COULD BE SUSTAINABLE WITH PLENTY OF
INSTABILITY. TEMPERATURES WILL BEGIN TO REBOUND THURSDAY IN THE
UPPER 70S TO LOWER 80S...AND THE RETURN OF WARM AIR ADVECTION WILL
BRING TEMPERATURES BACK TO NEAR NORMAL ON FRIDAY.
SATURDAY...THE NEXT UPPER LEVEL TROUGH LOOKS TO BEGIN TO MOVE INTO
THE PACIFIC NORTHWEST ON SATURDAY...WHICH COULD BE THE NEXT WEATHER
MAKER FOR THE REGION NEXT WEEKEND. CHANCES FOR AFTERNOON STORMS WILL
CONTINUE ON SATURDAY AS THE POSSIBILITY OF THE NEXT COLD FRONTAL
PASSAGE WILL AFFECT THE AREA. MODEL TIMING VARIES ON THE PASSAGE TO
EITHER SATURDAY OR SUNDAY...SO CONFIDENCE IS LOW REGARDING PINNING
DOWN PRECIPITATION CHANCES AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1126 AM MDT SUN JUL 13 2014
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON AS A RESULT OF SURFACE HEATING AND WEAK UPSLOPE SURFACE
WINDS IN A VERY MOIST AIR MASS. CONFIDENCE IS LOW THAT EITHER
TERMINAL WILL BE DIRECTLY IMPACTED. OVERNIGHT...A COLD FRONT WILL
MOVE THROUGH THE AREA WHICH WILL BE ACCOMPANIED BY SCATTERED
SHOWERS AND THUNDERSTORMS. AREAL COVERAGE WILL BE A BIT BETTER
WITH THE FRONT SO INCLUDED A MENTION OF VCTS AND EXPECTED TIMING
AT BOTH KGLD AND KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...MK
AVIATION...024
AREA FORECAST DISCUSSION
NWS JACKSON KY
112 PM EDT SUN JUL 13 2014
.UPDATE...
ISSUED AT 112 PM EDT SUN JUL 13 2014
SCATTERED CONVECTION HAS DEVELOPED OVER FAR SE KY AND THERE ARE SOME
ISOLATED CELLS OVER WESTERN KY AS WELL. CONVECTION IS ALSO DEVELOPING
ACROSS OH AND INDIANA IN ADVANCE OF THE INITIAL FRONT WHICH IS IN
ADVANCE OF THE MAIN COLD FRONT WHICH IS STILL IN THE UPPER MIDWEST.
CURRENT PRECIPITATION FORECAST STILL LOOKS TO BE COVERING THE CURRENT
SITUATION...AND WILL ONLY MAKE SOME ADJUSTMENTS TO THE GRIDS TO
ACCOUNT FOR THE LATEST OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 1110 AM EDT SUN JUL 13 2014
NDFD AND ASSOCIATED PRODUCTS HAVE BEEN UPDATED FOR LATEST
OBSERVATIONAL TRENDS. CURRENT THINKING ON THUNDERSTORM DEVELOPMENT IS
CONSISTENT WITH EARLY MORNING FORECAST GRIDS. A COLD FRONT EXTENDING
FROM SE MI TO CENTRAL IL SHOULD SERVE AS FOCUS FOR ORGANIZED
THUNDERSTORM DEVELOPMENT ACROSS OH AND INDIANA THIS AFTERNOON. LATEST
THINKING WHICH IS SUPPORTED BY SHORT RANGE GUIDANCE INCLUDING THE RAP
AND HRRR POINT TOWARDS THIS MOVING INTO THE NORTHERN PART OF THE
FORECAST AREA THIS EVENING. PRIOR TO THIS ISOLATED TO SCATTERED
CONVECTION WILL BE POSSIBLE ACROSS THE AREA...ALTHOUGH LOCALIZED
INSTABILITY OVER THE FAR SE WILL LEAD TO THUNDERSTORM CHANCES THERE
PRIOR TO CHANCES IN THE CENTRAL PART OF THE FORECAST AREA. WILL
CONTINUE TO BRING IN CHANCES TO THE NORTH AND SOUTHEAST PART OF THE
FORECAST AREA BEFORE THE CENTRAL AND SOUTHWEST PARTS OF THE AREA.
UPDATE ISSUED AT 750 AM EDT SUN JUL 13 2014
HOURLY GRIDS HAVE BEEN FRESHENED UP BASED ON THE RECENT OBSERVATIONS.
OTHERWISE...NO AWOS OR ASOS SITES WERE REPORTING FOG...AS THE MID
CLOUD DECK HAS GENERALLY HINDERED IT FROM DEVELOPING. WITH THAT IN MIND...
FOG WAS REMOVED FROM THE GRIDS TO START THE DAY. OTHERWISE...THE PREVIOUS
FORECAST REMAINS ON TARGET WITH ISOLATED TO SCATTERED CONVECTION ANTICIPATED
TO BEGIN TO DEVELOP AROUND OR SHORTLY AFTER NOON.
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 420 AM EDT SUN JUL 13 2014
AN UPPER LEVEL RIDGE WAS CENTERED ACROSS PARTS OF THE SOUTHERN PLAINS
AND EXTENDING EAST INTO THE SOUTHEASTERN STATES...WITH THE RIDGE
EXTENDING INTO THE INTER MOUNTAIN WEST. MEANWHILE TO ITS EAST A
TROUGH EXTENDED SOUTH INTO THE UPPER MS VALLEY REGION AND NORTHERN
GREAT LAKES FROM A RATHER STRONG MID SUMMER UPPER LEVEL LOW CENTERED
OVER NORTHWEST ONTARIO. ONE MID LEVEL SHORTWAVE IS WORKING ACROSS THE
OH VALLEY REGION AT THIS TIME...WITH ANOTHER WORKING ACROSS THE GREAT
LAKES REGION. THIS COMBINATION IS PUSHING A RATHER SHEARED OUT EAST
TO WEST COLD FRONT INTO THE SOUTHERN GREAT LAKES TO MID MS VALLEY
REGION...WITH THE FRONT ALSO APPROACHING THE LOWER OH VALLEY REGION.
MID AND HIGH CLOUDS CONTINUE TO WORK GRADUALLY EAST SOUTHEAST ACROSS
MUCH OF THE AREA. PARTS OF THE SOUTHERN CWA NEAR THE KY/VA/TN TRI
STATE AREA HAVE EXPERIENCED THE LEAST AMOUNT OF CLOUDS AND
TEMPERATURES...ESPECIALLY IN VALLEYS HAVE BEEN SLIGHTLY COLDER IN
THESE LOCATIONS. SO FAR THIS MORNING...NO ASOS OR AWOS SITES HAVE
REPORTED ANY FOG. HOWEVER...NEAR ZERO DEWPOINT DEPRESSIONS IN SOME
VALLEY LOCATIONS SUGGEST THAT AT LEAST SOME LIGHT RIVER VALLEY FOG IS
PROBABLY OCCURRING.
THE SHORTWAVE GENERALLY PASSING BY TO THE NORTH OVER THE NEXT FEW
HOURS WILL SERVE TO FURTHER SHEAR OUT THE COLD FRONT FROM EAST TO
WEST WITH IT STALLING OUT AND WASHING OUT OR MERGING WITH A MORE
SUBSTANTIAL COLD FRONT THAT SHOULD APPROACH THE OH VALLEY LATE IN THE
PERIOD. THIS SECOND COLD FRONT WILL BE PUSHED SOUTHEAST AS THE UPPER
LEVEL FLOW DROPS SOUTH INTO THE GREAT LAKES REGION ON MONDAY...WITH
THE OVERALL PATTERN AMPLIFYING. THIS UPPER LOW AND THE ASSOCIATED
SHORTWAVES TO ROTATE THROUGH THE DEVELOPING TROUGH SHOULD LEAD TO AN
INCREASE IN FORCING LATE TONIGHT AND ON MONDAY. RETURN LOW AND
MOISTURE FLUX AHEAD OF THIS BOUNDARY IS LEADING TO A SUBSTANTIAL
INCREASE IN MOISTURE AT THE LOW LEVELS AND ALOFT. THIS INCREASE IN
MOISTURE WILL CONTINUE WITH PW EXPECTED TO GRADUALLY CLIMB TO CLIMB TO
ABOUT 1.75 INCHES BY LATE AFTERNOON OR EARLY EVENING...WITH SLIGHTLY
HIGHER VALUES ANTICIPATED ACROSS THE FAR NORTHWEST. MODEL FORECAST
SHOW SOME FLUCTUATIONS IN PW VALUES DUE TO DIFFERENT TIMING OF
CONVECTION AND SHORTWAVES. THE GFS SHOWS THE MOST VARIABILITY OF PW
FROM TONIGHT INTO MONDAY. MEANWHILE THE NAM HAS THE HIGHEST VALUES ON
AVERAGE.
CONVECTION WILL BE POSSIBLE AT ANY TIME FROM MIDDAY TODAY THROUGH THE
END OF THE PERIOD. MODEL GUIDANCE CONTINUES TO SHOW THE POTENTIAL FOR
CONVECTION TO DEVELOP ACROSS THE HIGHER TERRAIN NEAR THE VA/TN/KY TRI
STATE AREA FIRST AND THEN ACROSS THE NORTHERN PART OF THE CWA CLOSER
TO THE BOUNDARY AND PASSING SHORTWAVES. GREATER INSTABILITY AND A BIT
STRONGER SHEAR LATER THIS AFTERNOON AND EVENING SHOULD BE REALIZED
ACROSS THE NORTHWEST COUNTIES. MODELS DEVELOP SOME MODERATE INSTABILITY
ACROSS THAT AREA...A FEW STRONG TO POSSIBLY A SEVERE THUNDERSTORM OR
TWO MAY OCCUR. CONVECTION BY THIS EVENING OR TONIGHT ALSO MIGHT TRAIN
WEST TO EAST ACROSS PARTS OF THE AREA...ESPECIALLY NORTHWEST WITH THE
STEERING FLOW BECOMING NEARLY PARALLEL TO THE STALLING BOUNDARY. WITH
THE PW NEAR OR ABOVE THE 75TH PERCENTILE LOCALLY HEAVY RAIN MAY BE
PRIMARY THREAT ACROSS THE NORTH FROM LATE THIS AFTERNOON INTO
TONIGHT. RECENT DAYS HAVE BEEN DRY AND MANY LOCATIONS HAVE BELOW
NORMAL RAINFALL OVER THE PAST 4 TO 6 WEEKS...SO IT WOULD TAKE AN
INITIAL SHOT OR TWO OF HEAVY RAIN FOLLOWED BY ADDITIONAL HEAVY RAIN
SHORTLY THEREAFTER TO PRIME ANY LOCATION.
ON MONDAY...THE GREATER INSTABILITY SHOULD RESIDE FURTHER SOUTHEAST
OF THE STALLED BOUNDARY AND THE APPROACHING FRONT. THIS COMBINED WITH
FORCING FROM HEIGHT FALLS...SHOULD AGAIN LEAD TO ROUNDS OF SHOWERS
AND THUNDERSTORMS. IF PARTS OF THE REGION CLEAR OUT FOR A FEW HOURS...
A PREFRONTAL MULTICELL CLUSTER OR LINE OR TWO OF STORMS COULD BECOME
STRONG TO SEVERE AS MODERATE INSTABILITY IS FORECAST BY THE MODELS
ACROSS THE SOUTH. STRONG WIND GUSTS AND LOCALLY HEAVY RAIN WOULD
AGAIN APPEAR TO BE THE MAIN THREATS FROM THE STORMS. AGAIN...DEPENDING
ON THE EVENTUAL MAGNITUDE AND EXTENT OF INSTABILITY SOME LOCALLY
HEAVY RAIN MIGHT BE A GREATER CONCERN THAN THE SEVERE THREAT.
.LONG TERM...(MONDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 AM EDT SUN JUL 13 2014
THE MODELS BEGIN THE EXTENDED PERIOD IN PRETTY GOOD AGREEMENT. THE
LARGE SCALE WEATHER PATTERN FEATURES A DEEP TROUGH OF LOW PRESSURE
IN THE UPPER ATMOSPHERE MOVING EAST OUT OF THE GREAT LAKES REGION
AND INTO NEW ENGLAND MONDAY NIGHT THROUGH TUESDAY NIGHT. THE WEATHER
MAKE WITH THIS SYSTEM FOR EASTERN KENTUCKY WILL BE A POTENT SURFACE
COLD FRONT. THIS FRONT LOOKS TO BE ORIENTED FROM WEST TO EAST
AND...IF THE MODELS BE TRUE...WILL MOVE SLOWLY ACROSS CENTRAL AND
EASTERN KENTUCKY MONDAY NIGHT AND TUESDAY. NUMEROUS SHOWERS AND
STORMS ARE EXPECTED TO BREAK OUT ALONG THE BOUNDARY IN THE WARM AND
HUMID AIR MASS THAT WILL BE IN PLACE. SOME OF THE STORMS MONDAY
EVENING COULD BE STRONG TO SEVERE WITH DAMAGING WINDS AND LOCALLY
HEAVY RAINFALL BEING THE PRIMARY THREATS. ONCE THE COLD FRONT MOVES
OUT OF THE AREA TUESDAY NIGHT...A LARGE RIDGE OF CANADIAN HIGH
PRESSURE WILL USHER COOLER AND DRIER AIR INTO THE AREA THROUGH THE
END OF THE WEEK. THE MODELS DIVERGE A BIT WITH THEIR SOLUTIONS FROM
FRIDAY NIGHT ONWARD...SO THAT PORTION OF THE FORECAST WILL BE LOWER
CONFIDENCE. THAT BEING SAID...INCORPORATED THE POSSIBILITY OF
ISOLATED SHOWERS AND STORMS FOR FRIDAY ONWARD DUE TO MODEL
UNCERTAINTY. TEMPERATURES TO BEGIN THE PERIOD WILL BE QUITE
UNSEASONABLE...WITH HIGHS ONLY MAKING IT INTO THE MID TO UPPER 70S
FROM TUESDAY THROUGH THURSDAY. THE AIR MASS WILL MODIFY SLIGHTLY TO
END THE WEEK AND INTO THE WEEKEND...AS HIGHS ARE EXPECTED TO WARM TO
AROUND 80 FROM FRIDAY ONWARD. OVERNIGHT LOWS WILL BE MOSTLY IN THE
LOW TO MID 60S...WITH COOLER LOWS OF THE MID TO UPPER 50S TUESDAY
NIGHT AND WEDNESDAY NIGHT AS THE NEW AIR MASS SETTLES OVER THE
REGION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 112 PM EDT SUN JUL 13 2014
VFR CONDITIONS WILL PREVAIL INTO AND THROUGH MOST OF THE UPCOMING
NIGHT...WITH MVFR EXPECTED LATE IN THE FORECAST PERIOD WITH SHOWERS
AND THUNDERSTORMS. CONVECTION THIS AFTERNOON IS NOT EXPECTED TO
AFFECT THE TAF SITES. ISOLATED TO SCATTERED CONVECTION TIED TO A WEAK
AREA OF INSTABILITY OVER FAR SE KY SHOULD REMAIN SE OF THE TAF SITES.
CONVECTION DEVELOPING AHEAD OF A COLD FRONT IN INDIANA AND OHIO WILL
REMAIN NORTH OF THE TAF SITES TODAY. THE CONVECTION OVER SE KY WILL
DIE OFF AFTER SUNSET WHILE THE SHOWERS AND THUNDERSTORMS DEVELOPING
OVER OH AND INDIANA SHOULD AFFECT THE TAF SITES LATE TONIGHT AND
EARLY ON MONDAY. MORE THUNDERSTORMS ARE EXPECTED MONDAY AFTERNOON
BEYOND THE CURRENT TAF FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...JP
LONG TERM...AR
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
250 PM EDT SUN JUL 13 2014
.SYNOPSIS...
BERMUDA HIGH WILL KEEP SOUTHERLY FLOW ACROSS THE MID-ATLANTIC INTO
TUESDAY. A COLD FRONT WILL APPROACH THE AREA TONIGHT AND STALL
OVER THE AREA MONDAY BEFORE PUSHING EAST LATE TUESDAY. CANADIAN
HIGH PRESSURE WILL BUILD ACROSS THE EASTERN STATES WEDNESDAY
THROUGH THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 18Z...THE BERMUDA HIGH HAS SET UP WITH SLY FLOW ACROSS THE
AREA. DEWPOINTS HAVE RISEN A COUPLE DEGREES TO AROUND 70F SINCE
DAYBREAK. A COLD FRONT IS OVER THE MIDWEST...EXTENDING WSW FROM THE
ERN GREAT LAKES THROUGH INDIANAPOLIS. SCATTERED THUNDERSTORMS HAVE
BROKEN OUT ALONG THIS BOUNDARY. THESE WILL BE THE FOCUS OF THE MOST
SIGNIFICANT WEATHER FOR THE AREA THROUGH TONIGHT. TONIGHT IS A GOOD
OPERATIVE WORD AS THE 15Z HRRR HAS THIS ACTIVITY REACHING THE
POTOMAC HIGHLANDS AROUND 6PM AND SPREADING EAST INTO THE AREA AFTER
THAT. 6PM TO 2AM IS THE ANTICIPATED TIMEFRAME FOR THUNDERSTORMS TO
ENTER THE AREA AND REACH THE BALT-WASH METRO. THE COLD FRONT WILL
STALL OR EVEN RETROGRADE TONIGHT. THIS WILL MAKE FOR AN ACTIVE
MONDAY.
INCREASING MOISTURE IS MAKING FOR AN UNSTABLE AFTERNOON. RAP
ESTIMATES FROM SPC MESOANALYSIS PAGE DEPICTS 1500 TO 3000 J/KG SOUTH
OF DC. THIS IS MAINLY DUE TO THE SUNSHINE THAT HAS BEEN STRONG
SOUTHEAST OF DC. AREAS SOUTH AND SOUTHEAST SHOULD SEE SOME TSTM
DEVELOPMENT LATE THIS AFTERNOON (THOUGH THE CU FIELD CURRENTLY SEEMS
TO BE STRUGGLING TO TAKE HOLD). WITH BULK SHEAR 20 KT OR LESS THIS
WOULD BE PULSE ACTIVITY. OTHERWISE...IT IS A WAITING GAME FOR THE
OHIO ACTIVITY WHICH CONTINUES TO INCREASE SINCE 18Z.
TONIGHT...BULK SHEAR INCREASES AS THE COLD FRONT APPROACHES ALLOWING
MULTI-CELL CLUSTERS. PWATS APPROACHING 2IN WILL ALLOW FOR HEAVY
RAIN...SO A FLASH FLOOD THREAT EXISTS FOR TONIGHT. CLOUDS AND SLY
FLOW KEEP MIN TEMPS UP...GENERALLY LOW TO MID 70S.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
MONDAY AND TUESDAY...SECONDARY LOBE OF DEEP LOW NORTH OF THE GREAT
LAKES SWINGS DOWN INTO THE GREAT LAKES MONDAY...AMPLIFYING THE
TROUGH OVER THE MIDWEST STATES INTO TUESDAY. MEANWHILE THE STALLED
FRONT WILL BE THE FOCUS OF DEVELOPMENT FOR OVER 24 HRS. THERE SHOULD
BE A DIURNAL EBB AND FLOW OF ACTIVITY WITH MONDAY EVENING (ACROSS
THE CWA) AND TUESDAY AFTERNOON/EVENING (EAST OF THE BLUE RIDGE)
BEING THE MOST HIGH IMPACT TIMES. SLIGHT RISK FOR MONDAY. LOW LEVEL
SHEAR PROFILES STILL LOOK TOO WEAK TO PROVIDE A TORNADO THREAT.
HEAVY RAIN AND DAMAGING WINDS ARE THE MAIN THREATS. SPC DAY 2 UPDATE
DOES MENTION THE POTENTIAL FOR SFC LOW DEVELOPMENT ALONG THE FRONT.
THIS WOULD PROVIDE AT LEAST SOME TORNADO THREAT...SO THAT THREAT
WILL NEED TO BE FOLLOWED BY SUBSEQUENT FORECAST SHIFTS.
ABOVE NORMAL TEMPERATURES PERSIST THROUGH TUESDAY AHEAD OF THE COLD
FRONT.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL USHER IN STABLE AIR WEDNESDAY INTO WEDNESDAY
NIGHT. THERE IS A CHANCE THAT A SHOWER OR PERHAPS A RUMBLE OF
THUNDER WILL LINGER ACROSS PARTS OF SOUTHERN MARYLAND AND THE
CHESAPEAKE BAY...MAINLY EARLY WEDNESDAY. TEMPERATURES WILL BE COOLER
THAN NORMAL FOR THE MIDDLE OF JULY. A PLEASANT NIGHT WEDNESDAY NIGHT
WITH TEMPERATURES A FEW DEGREES BELOW NORMAL.
A FEW POP-UP SHOWERS COULD DEVELOP THURSDAY INTO THURSDAY EVENING AS
A WEAK PIECE OF ENERGY PIVOTS ACROSS THE REGION. MOST OF THE
ACTIVITY WOULD DEVELOP IN THE POTOMAC HIGHLANDS AND SHENANDOAH
VALLEY WHERE IT WOULD BECOME SLIGHTLY LESS STABLE THAN THE
METROPOLITAN AND CHESAPEAKE BAY AREAS. TEMPERATURES SHOULD REMAIN
BELOW NORMAL.
A STRONGER PIECE OF UPPER LEVEL ENERGY RIDING ALONG THE OHIO VALLEY
FRIDAY INTO FRIDAY NIGHT WILL BRING A BETTER CHANCE OF SHOWERS AND
EVEN A COUPLE OF THUNDERSTORMS ANYWHERE ACROSS THE REGION. THE GFS
MODEL WANTS TO SLOW DOWN THE NORTHEASTWARD PROGRESS OF THIS ENERGY
SATURDAY AND SATURDAY NIGHT. BOTH THE EURO AND GFS SHOW THIS TYPE OF
ACTIVE PATTERN FRIDAY THROUGH SATURDAY NIGHT. WE KEPT CHANCE OF
SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY NIGHT AS WELL.
TEMPERATURES FRIDAY SHOULD BE SLIGHTLY BELOW NORMAL OR NEAR NORMAL.
IF THERE IS A LARGE AND PERSISTENT COVERAGE OF SHOWERS AND
THUNDERSTORMS SATURDAY...THEN TEMPERATURES COULD REMAIN BELOW
NORMAL. IF SHOWERS AND THUNDERSTORMS DEVELOP IN LIEU OF DAYTIME
HEATING LATER IN THE AFTERNOON AND EVENING...THEN TEMPERATURES COULD
TURN OUT TO BE A FEW DEGREES ABOVE NORMAL.
WITH ONE PIECE OF ENERGY FOLLOWING ANOTHER SUNDAY...WE LEFT CHANCES
OF SHOWERS AND THUNDERSTORMS FOR NOW. THERE APPEARS TO BE NO BIG
PATTERN CHANGE TOWARD THE LATTER PART OF NEXT WEEKEND.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR PREVAILS INTO THIS EVENING AHEAD OF THUNDERSTORMS ALONG A COLD
FRONT APPROACHING FROM THE MIDWEST. IFR IN HEAVY TSRA. OTHERWISE SLY
FLOW 10-15KT. THUNDERSTORMS ON TAP FOR MONDAY EVENING AND TUESDAY
AFTERNOON/INTO THE EVENING AS THE COLD FRONT STALLS FOR
MONDAY...THEN PUSHES EAST TUESDAY.
MVFR OR IFR CONDITIONS ARE POSSIBLE FOR MTN...BWI AND PERHAPS DCA
WEDNESDAY WITH SOME SHOWER OR THUNDERSTORM ACTIVITY IN THE
VICINITY...MAINLY EARLY IN THE DAY. ALL OTHER TERMINALS SHOULD HAVE
VFR CONDITIONS. WINDS WILL BE NORTHWEST WEDNESDAY VEERING AROUND TO
THE NORTH LATER WEDNESDAY LESS THAN 10 KNOTS. WINDS MAY BE STRONGER
IN SHOWERS OR THUNDERSTORMS EARLY WEDNESDAY AT THE MTN...BWI AND DCA
TERMINALS.
MVFR OR IFR CONDITIONS MAY OCCUR AT THE CHO OR IAD TERMINALS DUE TO
POP-UP SHOWERS AND THUNDERSTORMS POSSIBLY AROUND THURSDAY.
OTHERWISE...VFR CONDITIONS ELSEWHERE.
&&
.MARINE...
SLY FLOW 15-20 KT UP THE MD PORTION OF THE BAY AND LOWER TIDAL
POTOMAC INTO LATE TONIGHT...WITH MD WATERS SOUTH OF SANDY POINT IN
AN SCA INTO MONDAY MORNING. GUSTS TO AROUND 22 KT. SLY FLOW
GENERALLY 10-15KT MONDAY AFTERNOON AND NIGHT. HOWEVER...GUSTY
THUNDERSTORMS AND SPECIAL MARINE WARNING ARE POSSIBLE BOTH MONDAY
AND TUESDAY. COLD FRONT MOVES EAST FROM THE WATERS TUESDAY NIGHT.
NO HAZARD MARINE CONDITIONS EXPECTED WEDNESDAY THROUGH THURSDAY.
&&
.TIDES/COASTAL FLOODING...
WATER LEVELS HAVE INCREASED TO THREE QUARTERS OF A FOOT ABOVE A FULL
MOON NORMAL THIS AFTERNOON AND MAY INCREASE MORE AS SLY FLOW
INCREASES THIS EVENING. THE PREFERRED MORNING HIGH TIDE MONDAY
SHOULD BE MORE IMPACTFUL THAN THIS MORNING`S HIGH TIDE THAT SIMPLY
REACHED THE MINOR FLOODING THRESHOLD OF 2.40 FT. EXPECT A COASTAL
FLOOD ADVISORY FOR ANNE ARUNDEL...WASHINGTON DC...AND POSSIBLY
BALTIMORE/ALEXANDRIA.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT MONDAY FOR ANZ530-531-539.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ532>534-540-
541-543.
SMALL CRAFT ADVISORY UNTIL 10 AM EDT MONDAY FOR ANZ537.
&&
$$
SYNOPSIS...BAJ
NEAR TERM...BAJ
SHORT TERM...BAJ
LONG TERM...KLW
AVIATION...BAJ/KLW
MARINE...BAJ/KLW
TIDES/COASTAL FLOODING...BAJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 PM EDT SUN JUL 13 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 437 PM EDT SUN JUL 13 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID/UPPER LEVEL LOW
OVER NW ONTARIO. THE COMBINATION OF INCREASING LOW LEVEL MOISTURE
AROUND THE LOW WITH SFC-700 MB LAPSE RATES ABOVE 8C/KM AND DAYTIME
HEATING SUPPORTED SCT/ISOLD LIGHT SHOWERS FROM NE MN INTO WRN LAKE
SUPERIOR AND NW WI. OTHERWISE...BREEZY WEST WINDS PREVAILED OVER
UPPER MI WITH A RELATIVELY TIGHT PRES GRADIENT AROUND A 997 MB LOW
NEAR JAMES BAY.
TONIGHT...AS THE MID LEVEL LOW SAGS TOWARD THE NRN LAKES...EXPECT
SOME ISOLD LIGHT SHOWERS OR SPRINKLES MAY DEVELOP INTO WRN UPPER MI
THIS EVENING. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...THE PCPN
COVERAGE/INTENSITY WILL DIMINISH. MODERATE/STRONG 700-300 QVECTOR
CONV AHEAD OF THE LOW MOVING INTO THE WEST BY 06Z AND EAST OVERNIGHT
WILL SUPPORT ADDITIONAL LIGHT PCPN OVER THE AREA OVERNIGHT.
MON...MID 700-500 MB TROUGH MOVING OVER THE AREA WILL PROVIDE ENOUGH
INSTABILITY (700 MB TEMPS TO AROUND -6C) FOR NMRS SHOWERS OVER THE
LAND AS DAYTIME HEATING INCREASES. ALTHOUGH THE MODELS SUGGEST THAT
MUCAPE VALUES OF 400 J/KG MAY BE POSSIBLE...WITH ONLY SHALLOW/NARROW
CAPE EXPECTED...AND LACK OF LIGHTNING THIS AFTERNOON UPSTREAM...NO
MENTION OF TSRA WAS ADDED. MAX TEMPS WILL STAY WELL BELOW SEASONAL
AVERAGES...ESPECIALLY DOWNWIND FROM NW FLOW ACROSS LAKE
SUPERIOR...WITH HIGHS IN THE MID 50S TO LOWER 60S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 437 PM EDT SUN JUL 13 2014
MAIN ISSUES THIS FORECAST PERIOD ARE THE BELOW NORMAL TEMPERATURES
EXPECTED MONDAY NIGHT THROUGH TUESDAY NIGHT.
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE UPPER LEVEL 500MB LOW WILL
BE CENTERED OVER MUCH OF UPPER MICHIGAN AROUND 00Z/15. 1000-500MB RH
SHOWS SIGNIFICANT MOISTURE LINGERING ACROSS THE UPPER GREAT LAKES
REGION DURING THIS TIME FRAME WITH CO-LOCATED DEEP LAYER
FORCING...AS SHOWN BY OVERLAYING QCONV. THE BETTER CHANCE OF SHOWERS
WILL BE DURING THE EVENING HOURS AS THE AFOREMENTIONED SET UP
LINGERS ALONG WITH A GENERAL DIURNAL NATURE TO THE SHOWER
DEVELOPMENT. THE UPPER LEVEL LOW WILL CONTINUE TO SHIFT EASTWARD
THROUGH 18Z/15...REACHING THE SOUTHERN ONTARIO/QUEBEC BORDER. THE
BETTER FORCING/MOISTURE WILL ALSO SHIFT TO THAT
AREA...HOWEVER...ENOUGH MOISTURE WILL LINGER ACROSS THE EASTERN HALF
OF THE U.P. TO KEEP SCATTERED SHOWERS IN THE FORECAST WITH CONTINUED
UPPER LEVEL TROUGHING. HEIGHT RISES WILL BEGIN BUILDING INTO THE
WESTERN U.P. BY 18Z/15 ALONG WITH A BROAD SURFACE RIDGE. THIS SHOULD
ALLOW THE WESTERN U.P. TO BEGIN DRYING OUT. TEMPERATURES WILL BE
BELOW NORMAL THROUGH THIS TIME PERIOD WITH 850MB TEMPS 4C TO 5C.
OVERNIGHT LOWS WILL BE IN THE LOW TO MID 40S WITH HIGHS ONLY
REACHING INTO THE UPPER 50S TO AROUND 60. AREAS ALONG LAKE SUPERIOR
COULD STAY IN THE 40S THROUGH THE DAY TUESDAY. THIS WILL BE WELL
BELOW THE NORMS FOR THIS TIME OF YEAR...WHICH IS AROUND 77F/55F FOR
MAX AND MIN TEMP RESPECTIVELY FOR THE NWS OFFICE.
ADDITIONALLY...DROPPED THE TEMPERATURES A FEW MORE DEGREES FOR
TUESDAY NIGHT AS IT LOOKS AS IF DRIER AIR WILL PUSH INTO THE CWA
ALLOWING TEMPS TO FALL INTO THE LOWER 40S WITH A FEW UPPER 30S
POSSIBLE OVER THE INLAND WEST. CLOUDS MAY LINGER A BIT LONGER OVER
THE FAR EAST HELPING TO KEEP TEMPS IN THAT AREA A BIT WARMER.
WEDNESDAY THROUGH THE REMAINDER OF THE EXTENDED...TREND FOR QUIET
WEATHER DURING THIS TIME FRAME EXPECTED TO CONTINUE. THE SURFACE
HIGH PRESSURE WILL CONTINUE TO SLIDE ACROSS THE UPPER GREAT LAKES
REGION WEDNESDAY AND LINGER THROUGH SATURDAY AS IT SLOWLY SHIFTS TO
THE EASTERN SEABOARD. AT THE SAME TIME UPPER LEVEL HEIGHT RISES WILL
CONTINUE TO BUILD ACROSS THE REGION ALLOWING FOR A GRADUAL
MODERATION IN TEMPERATURES ACROSS THE AREA...REACHING NEAR NORMAL
LEVELS BY THE END OF THE WORK WEEK AND INTO THE FIRST PART OF THE
WEEKEND. LATE SATURDAY NIGHT INTO SUNDAY...MODELS ARE HINTING AT A
LOW PRESSURE SYSTEM PASSING NEAR THE U.P. BRINGING A COLD FRONT
THROUGH THE AREA. THIS IS QUITE FAR OUT FOR SPECIFIC TIMING BUT IT
DOES LOOK LIKE THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS
BY THE END OF THE UPCOMING WEEKEND. THE EC HAS BEEN FAIRLY
CONSISTENT WITH THE SYSTEM MOVING THROUGH...WHILE THE GFS CONTINUES
ITS TREND OF FLIP FLOPPING DURING THAT TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 144 PM EDT SUN JUL 13 2014
VFR CONDITIONS ARE EXPECTED UNTIL LATE TONIGHT. GUSTY WINDS ARE
EXPECTED THIS AFTERNOON WITH TERMINALS GUSTING 20-30KT. STRONGEST
WINDS WILL BE AT KCMX WHICH IS MORE EXPOSED TO A WNW WIND. EXPECT
CIGS TO DROP INTO THE MVFR RANGE LATE TONIGHT AT CMX/IWD AS ANOTHER
COLD FRONT MOVES THROUGH AND A MID/UPPER LEVEL LOW MOVES TOWARD THE
REGION. SOME LIGHT SHOWERS ARE ALSO EXPECTED BUT WITH VSBY STILL
REMAINING MVFR OR HIGHER. VFR CONDITIONS SHOULD PERSIST AT SAW WITH
A MORE DOWNSLOPE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 437 PM EDT SUN JUL 13 2014
EXPECT THAT THE GUSTY WNW WINDS OF 20 TO 25 KNOTS WILL DIMINISH THIS
EVENING AS THE PRES GRADIENT WEAKENS. WINDS SHOULD THEN REMAIN BELOW
20 KNOTS THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT SUN JUL 13 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 409 PM EDT SUN JUL 13 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A DEEP MID/UPPER LEVEL LOW
OVER NW ONTARIO. THE COMBINATION OF INCREASING LOW LEVEL MOISTURE
AROUND THE LOW WITH SFC-700 MB LAPSE RATES ABOVE 8C/KM AND DAYTIME
HEATING SUPPORTED SCT/ISOLD LIGHT SHOWERS FROM NE MN INTO WRN LAKE
SUPERIOR AND NW WI. OTHERWISE...BREEZY WEST WINDS PREVAILED OVER
UPPER MI WITH A RELATIVELY TIGHT PRES GRADIENT AROUND A 997 MB LOW
NEAR JAMES BAY.
TONIGHT...AS THE MID LEVEL LOW SAGS TOWARD THE NRN LAKES...EXPECT
SOME ISOLD LIGHT SHOWERS OR SPRINKLES MAY DEVELOP INTO WRN UPPER MI
THIS EVENING. HOWEVER...WITH THE LOSS OF DAYTIME HEATING...THE PCPN
COVERAGE/INTENSITY WILL DIMINISH. MODERATE/STRONG 700-300 QVECTOR
CONV AHEAD OF THE LOW MOVING INTO THE WEST BY 06Z AND EAST OVERNIGHT
WILL SUPPORT ADDITIONAL LIGHT PCPN OVER THE AREA OVERNIGHT.
MON...THE MID 700-500 MB TROUGH MOVING OVER THE AREA ALONG WITH
ABUNDANT SFC-700MB MOISTURE WILL PROVIDE ENOUGH INSTABILITY (700 MB TEMPS TO
AROUND -6C) FOR NMRS SHOWERS OVER THE LAND AS DAYTIME HEATING
INCREASES. ALTHOUGH THE MODELS SUGGEST THAT MUCAPE VALUES OF 400 J/KG
MAY BE POSSIBLE...WITH ONLY SHALLOW/NARROW CAPE EXPECTED...AND LACK
OF LIGHTNING THIS AFTERNOON UPSTREAM...NO MENTION OF TSRA WAS ADDED.
MAX TEMPS WILL STAY WELL BELOW SEASONAL AVERAGES...ESPECIALLY
DOWNWIND FROM NW FLOW ACROSS LAKE SUPERIOR...WITH HIGHS IN THE MID
50S TO LOWER 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 316 AM EDT SUN JUL 13 2014
MAIN FOCUS IN THE LONG TERM IS WITH POPS/TEMPS MON-WED.
MODELS CONTINUE TO DIFFER ON EXACT TRACK/STRENGTH DETAILS OF A
CLOSED UPPER LOW SET TO MOVE ACROSS THE AREA MON INTO TUE. THE LOW
IS CURRENTLY HANGING OUT OVER EXTREME NWRN ONTARIO AND IT SET TO
SPLIT IN TWO TODAY...SENDING A PIECE OF ENERGY INTO QUEBEC WHILE THE
OTHER ROTATES OVER OR NEAR THE CWA. MODELS PROBABLY WILL NOT BE IN
BETTER AGREEMENT UNTIL THE 00Z/14 RUNS WHICH WILL BE AFTER A LOT OF
THE ENERGY HAS SPLIT OUT OF THE SYSTEM. AS IT STANDS NOW...AT LEAST
MUCH OF THE CWA SHOULD SEE RAIN MON INTO MON NIGHT...WITH PRECIP
LINGERING INTO TUE. FACTORS CONTRIBUTING TO THE PRECIP INCLUDE THE
ENERGY/HEIGHT FALLS FROM THE UPPER LOW MOVING OVERHEAD...DAYTIME
INSTABILITY RESULTING FROM THE ANOMALOUSLY COLD TEMPS IN THE UPPER
LOW...AND NLY FLOW OFF LAKE SUPERIOR BETWEEN TROUGHING E AND A HIGH
WELL TO THE W. BEST CHANCES FOR RAIN BY FAR WILL BE ON MON DURING
PEAK HEATING...WHEN LIKELY POPS ARE IN THE FORECAST. THERE MAY WELL
BE SOME DRY SPOTS DEPENDING ON EXACT TRACK/STRENGTH OF THE COMPACTS
UPPER LOW...SO THOSE DETAILS WILL NEED TO BE MONITORED BY LATER
SHIFTS WHEN MODELS /HOPEFULLY/ COME INTO BETTER AGREEMENT. HAVE HIGH
TEMPS IN THE 50S W AND AROUND 60 S AND E. THESE TEMPS WILL BE AROUND
20 DEGREES BELOW NORMAL.
WITH THE N WINDS AND COLD CORE OF THE LOW STILL OVER THE CWA TUE
MORNING...HAVE SLIGHT CHANCE TO LOW END CHANCE POPS
LINGERING...MAINLY IN THE MORNING. THE UPPER LOW SHUNTS QUICKLY TO
THE NE ON TUE...WITH A SFC HIGH BECOMING MORE DOMINANT OVER THE WRN
CWA AS THE DAY PROGRESSES. HIGH TEMPS WILL LIKELY STRUGGLE TO REACH
60 IN MOST LOCATIONS...WITH SOME LAKE SUPERIOR SHORELINE AREAS
POSSIBLY NOT GETTING ABOVE 50. THESE TEMPS WILL BE AROUND
20-25 DEGREES BELOW NORMAL.
THINK THE MIN TEMP FORECAST FOR TUE NIGHT COULD BE TOO WARM...BUT
ONLY IF ENOUGH CLEARING OCCURS. WITH THE COLD DAY ON TUE...CLEARING
/OF UNCERTAIN MAGNITUDE/ TUE NIGHT FROM W TO TO E MAY LEAD TO SOME
COLDER MIN TEMPS OVER WRN UPPER MI. AMONG THE REASONS FOR THE
UNCERTAINTY ARE POSSIBLE SHORTWAVE ENERGY TRACKING AROUND THE
DEPARTING LOW/TROUGH AS INDICATED BY THE ECMWF AND THE POSSIBILITY
THAT THE WINDS MAY STAY UP ENOUGH TO KEEP TEMPS FROM BOTTOMING OUT
AS MUCH.
REMAINING UPPER TROUGHING WILL CONTINUE TO WEAKEN WED AS UPPER
RIDGING BUILDS TOWARD THE CWA. SKIES WILL BE MOSTLY SUNNY...AND THE
AIRMASS OVERALL WARMER...WHICH WILL ALLOW FOR WARMER SFC TEMPS WITH
HIGHS FROM AROUND 60 ALONG LAKE SUPERIOR TO AROUND 70 INLAND.
FORECAST WED NIGHT THROUGH NEXT SAT LOOKS PRETTY QUIET. NORMAL
UNCERTAINTY EXISTS DURING THIS PERIOD...BUT WITH WEAK UPPER RIDING
BUILDING INTO THE CENTRAL CONUS...SIGNIFICANT PRECIP IS NOT
EXPECTED. IN GENERAL...A WARMING TREND IS EXPECTED INTO THE WEEKEND.
BY SAT...HIGH TEMPS COULD REACH 80 OVER THE INTERIOR W.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 144 PM EDT SUN JUL 13 2014
VFR CONDITIONS ARE EXPECTED UNTIL LATE TONIGHT. GUSTY WINDS ARE
EXPECTED THIS AFTERNOON WITH TERMINALS GUSTING 20-30KT. STRONGEST
WINDS WILL BE AT KCMX WHICH IS MORE EXPOSED TO A WNW WIND. EXPECT
CIGS TO DROP INTO THE MVFR RANGE LATE TONIGHT AT CMX/IWD AS ANOTHER
COLD FRONT MOVES THROUGH AND A MID/UPPER LEVEL LOW MOVES TOWARD THE
REGION. SOME LIGHT SHOWERS ARE ALSO EXPECTED BUT WITH VSBY STILL
REMAINING MVFR OR HIGHER. VFR CONDITIONS SHOULD PERSIST AT SAW WITH
A MORE DOWNSLOPE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT SUN JUL 13 2014
EXPECT THAT THE GUSTY WNW WINDS OF 20 TO 25 KNOTS WILL DIMINISH THIS
EVENING AS THE PRES GRADIENT WEAKENS. WINDS SHOULD THEN REMAIN BELOW
20 KNOTS THROUGH FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
313 PM CDT Sun Jul 13 2014
.SHORT TERM: (Through Late Tonight)
Issued at 313 PM CDT Sun Jul 13 2014
Cold front has moved to a Effingham to St. Louis metro to Rolla
line at 20Z. Atmosphere is moderately unstable with MLCAPEs around
1000-1500 J/kg with an effective sheer of 35 kts. Still some
potential for a few severe thunderstorms capable of producing
primarily damaging winds with some large hail through the evening
hours given the amount of instability and shear in the SPC slight
risk area. Scattered thunderstorms have been developing over the
past couple of hours, primarily behind the front. A series of vort
maxes will continue to move across the area through early evening
per the RAP which will provide some modest ascent, but some
increase in overall coverage of thunderstorms should occur during
this evening over the southern and eastern parts the CWA when a
modest increase in 925-850mb moisture convergence occurs. This is
depicted well on the HRRR and NSSL-WRF simulated reflectivity.
These storms will shift south of the CWA overnight, though there
will be a slight chance of storms late tonight over northeast
Missouri and west central Illinois as a secondary cold front moves
south out of Iowa.
Britt
.LONG TERM: (Monday through Next Sunday)
Issued at 313 PM CDT Sun Jul 13 2014
(Monday through Wednesday)
The aforementioned secondary cold front will move southward through
the CWA during the day Monday as a stronger shortwave pivots
through the area. Expect additional scattered thunderstorms to
develop along front tomorrow because of this. There will be the
risk of a few severe thunderstorms along and ahead of the front
given forecast MLCAPE values of 1000-1500 J/kg and deep layer near
40kts. Storms will move out of the area by early Monday evening.
Monday should be out last warm day with 850mb temperatures between
14-18C. These temperatures will fall to between 8-12C on Tuesday
and Wednesday which should keep highs only in the lower to middle
70s. Lows on Tuesday morning look like they will fall into the
middle 50s in most areas because of decent raditional cooling and
dewpoints in the low 50s. Tuesday and Wednesday still look dry as we
will lie under subsidence in northwesterly flow aloft.
(Thursday through next Sunday)
GFS and ECMWF are still in relatively good agreement in showing that
the deep upper low that will be centered over the Great Lakes at
midweek will lift into eastern Canada on Thursday. At the same
time, another weaker upper low will be digging in behind it.
Expect a dry Thursday with the surface high bringing drier air
from the east with highs near 80 given the 850mb temperatures
around 12C. The GFS and ECMWF are in decent agreement on Friday
and Saturday that most of the precipitation associated with the
upper trough will stay to the south, so will keep the forecast
dry. Shower and thunderstorm chances will increase by next Sunday
as both models show a warm front moving northeast through the
area. 850mb temperatures will climb into the 17-19C range which
favor temperatures in the middle to upper 80s.
Britt
&&
.AVIATION: (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1238 PM CDT Sun Jul 13 2014
Frontal boundary extends along the I-70 corridor as of 17z.
Activity that was along it earlier has diminished. However, still
expect some showers and storms to fireup along it later this
afternoon. Timing and coverage still hard to pin down, so just
kept vcnty thunderstorm mention for KCOU and metro area tafs after
20z. Then this round to taper off and slide south of taf sites by
01z Monday. Otherwise, vfr conditions with west to northwest winds
becoming light and variable. Though at KUIN will see winds back to
the southwest this evening ahead of secondary cold front.
Secondary cold front with some additional storm activity to slide
through beginning around 15z Monday at KUIN and taf sites along
I-70 corridor around 17z Monday.
Specifics for KSTL:
Frontal boundary extends along the I-70 corridor as of 17z.
Activity that was along it earlier has diminished. However, still
expect some showers and storms to fireup along it later this
afternoon. Timing and coverage still hard to pin down, so just
kept vcnty thunderstorm mention for metro area after 20z. Then
this round to taper off and slide south of taf site by 01z
Monday. Otherwise, vfr conditions with northwest winds becoming
light and variable. Secondary cold front with some additional
storm activity to slide through beginning around 17z Monday...so
added vcnty thunderstorm mention with winds picking up and veering
to the northwest.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
155 PM EDT SUN JUL 13 2014
.SYNOPSIS...
AN UPPER LEVEL LOW DIGGING INTO THE GREAT LAKES WILL BRING PERIODS
OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS. THE
ASSOCIATED FRONTAL SYSTEM WILL WORK OFFSHORE BY TUESDAY
NIGHT...WITH DRIER WEATHER AND COOLER TEMPERATURES WORKING INTO
CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1010 AM UPDATE...LEADING SHORT WAVE MOVING THROUGH WRN NY WITH
RESULTING CONVECTION SPREADING ACROSS THE FINGER LAKES AND CENTRAL
SRN TIER ATTM. SOME OF THE CONVECTION IS PRODUCING GUSTY WINDS AND
BRIEF HEAVY DOWNPOURS. ACTIVITY IS EXPECTED TO HOLD TOGETHER AND
SPREAD ACROSS THE REGION DURING THE LATE MORNING AND AFTERNOON
HOURS. WILL CONTINUE TREND OF INCREASING POPS INTO THE
CATEGORICAL/LIKELY POP RANGE AND HIGH CHC/LOW LIKELY OVER NE PA.
AS FOR SVR WX POTENTIAL THE MID LEVEL FLOW AND LOW LEVEL
SHEAR/HELICITY ARE VERY FAVORABLE FOR SVR WX BUT THE LIMITING
FACTOR IS THE INSTABILITY. LATEST RAP MODEL GUIDANCE INDICATES
CAPE VALUES OF 400-800 J/KG WHICH SEEMS REASONABLE CONSIDERING THE
ABOUT OF CLOUDS ALREADY OVER THE REGION. A PRE-FRONTAL TROF
CURRENTLY BACK IN OHIO IS PROGGED TO CROSS THE REGION THIS
AFTERNOON AND EVENING WHICH MAY FOCUS ACTIVITY AFTER THIS INITIAL
ACTIVITY. SPC LATEST UPDATE KEEPS MUCH OF THE AREA IN SLIGHT RISK,
IF SUNNY PERIODS DEVELOP THIS AFTERNOON IT COULD GET INTERESTING.
BASED ON ENV WINDS AND LACK OF SIGNIFICANT CAPE THE MAIN SVR WX
THREAT WOULD BE DAMAGING WINDS. ALONG WITH THE SVR POTENTIAL
AIRMASS IS REALLY JUICY SO ANY CONVECTION TODAY WITH HAVE HEAVY
DOWNPOURS.
PREVIOUS DISC...
AN UNSETTLED PTRN OVER THE NXT FEW DAYS AS STRONG UPR LOW...WITH
S/WV`S PIVOTING ARND IT...DROPS SEWD INTO THE GTLAKES. MDLS TDA
SHOW THE DVLPMNT OF A PRE-FNTL TROF ACRS CNTRL NY AND PA THIS
AFTN...WITH CDFNT MOVG INTO WRN NY.
LOW LVL JET FOCUSES ACRS WRN NY ACRS LAKE ONTARIO INTO THE ST
LAWRENCE WHERE BEST UPR LVL DVRGNC WILL BE LOCATED. BIG QUESTION WILL BE
AMT OF HEATING WE GET TDA. ATTM IT APPEARS THAT SUNSHINE WILL BE
LIMITED WITH ALOT OF CONVECTIVE DEBRIS ACRS THE RGN THIS MRNG. MESO
DATA ACTUALLY SHOWS SFC TEMPS FALLING THIS AFTN ACRS CNTRL NY WITH
PSSG OF A CONVECTIVE LINE. NAM CAPES MAX OUT BETWEEN 500-1000
J/KG. GFS CAPES MUCH LESS GNRLY 250-500. LCL WRF GETS CAPE UP TO
750 J/KG BUT INDICATES A TALL SKINNY CAPE. WIND FIELDS LOOK GOOD
HOWEVER. PRECIPITABLE H20 VALUES APRCHNG 2 INCHES. RUC BRN`S IN
THE SUPERCELL RNG THIS AFTN. FOR NOW...WE WILL INDICATE POTNL FOR
+RA AND GUSTY WINDS WITH TSRA THIS AFTN/EVNG.
ACTIVITY SHUD SLIDE INTO NE PA BY EARLY EVNG...WITH BEST CHCS FOR
SHRA/TSRA PERSISTING ACRS THIS AREA TNGT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
UPR LOW CONTINUE TO DIG INTO THE GTLAKES THIS PD WHILE ASSUMING A
NEUTRAL OR SLIGHTLY NEGATIVELY TILT. MSTR XPCTD TO MOV BACK NWD
AHEAD OF THE NXT S/WV AND SFC FNT LATE MON AND MON NGT. SOME
TIMING DIFFS EMERGE LATE IN THE PD BUT TREND WILL BE FOR IMPRVG
CONDITIONS ACRS THE RGN ON TUE NGT. XCPTN MAY BE ACRS THE POCONOS
AND SRN CATSKILLS WHERE POTNL FOR MDT TO HVY SHRA/TSRA MAY EXIST
AS AS A WAVE OF LOW PRES LIFTS NEWD ALONG THE FNT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
NOON UPDATE...
THE BIG STORY DURING THE LONG TERM FORECAST WILL BE A BROAD UPPER
LEVEL TROF OVER THE EASTERN HALF OF THE US WITH COOLER THAN AVERAGE
TEMPS, AND A POSSIBLE RETURN TO UNSETTLED WEATHER BY THE WEEKEND.
MAINLY DRY WEATHER IS EXPECTED WEDNESDAY NIGHT INTO EARLY FRIDAY.
DURING THIS PERIOD A SHORT WAVE WILL MOVE THROUGH IN THE MEAN FLOW
DURING THE DAY THURSDAY. I CONTINUED A DRY FORECAST BUT A POP UP
SHOWER CAN`T BE RULED OUT THIS DAY AS THE SHORT WAVE MOVES
THROUGH. WITH THE BASE OF THE UPPER LEVEL TROF STILL OVER CENTRAL
TX, WE AREN`T QUITE OUT OF THE WOODS FOR MORE PRECIPITATION AS WE
HEAD TOWARD THE WEEKEND. AS THIS TROF MOVES EAST OVER THE
SOUTHEASTERN US, A DEEP SOUTHWEST FLOW WILL DEVELOP AND TRANSPORT
MOISTURE UP THE ATLANTIC COAST. THE TIMING AND HOW FAR NORTH THE
MOISTURE GETS IS STILL VERY MUCH IN QUESTION. THE OLDER RUNS OF THE
GFS ARE ABOUT 24 HOURS FASTER THAN THE EURO, BRINGING IN SHOWERS
BY FRIDAY EVENING WITH THE EURO NOT UNTIL SATURDAY EVENING.
WHATEVER THE CASE IT DOES APPEAR CHANCES WILL INCREASE FOR SHOWERS
OVER THE WEEKEND ITSELF. ON THE FRONT END I PUT IN JUST A 20%
CHANCE FOR SHOWERS IN NEPA FRIDAY BUT SAVE HIGHER CHANCES FOR SAT/SUN.
IF THE PATTERN HOLDS CHANCES FOR RAIN MAY NEED TO BE INCREASED THIS
WEEKEND BUT STILL WAY TOO FAR AND UNCERTAIN AT THIS POINT FOR
ANYTHING MORE THAN THAT.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHOWERS AND THUNDERSTORMS ARE LIKELY OVER THE TERMINALS THROUGH
0Z. WHILE BRIEF IFR IS POSSIBLE EVERYWHERE, MOST LIKELY TERMINALS
WILL BE FROM NEAR KELM THROUGH KBGM/KITH AND KAVP. STRONG GUSTY
WINDS ALSO POSSIBLE HERE WITH MORE ORGANIZED LINES OF STORMS.
ENHANCED THE WIND WORDING HERE TO SHOW THAT ALONG WITH IFR VSBYS.
CONVECTION DIMINISHES THIS EVENING BUT LEFTOVER MOISTURE WILL
PRODUCE MVFR RESTRICTIONS OVERNIGHT.
OUTLOOK...
MON THROUGH TUE NGT...POTENTIAL RESTRICTIONS FROM SHRA/TSRA.
WED/THUR/FRI...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RRM
SHORT TERM...
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1206 PM EDT SUN JUL 13 2014
.SYNOPSIS...
AN UPPER LEVEL LOW DIGGING INTO THE GREAT LAKES WILL BRING PERIODS
OF SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS. THE
ASSOCIATED FRONTAL SYSTEM WILL WORK OFFSHORE BY TUESDAY
NIGHT...WITH DRIER WEATHER AND COOLER TEMPERATURES WORKING INTO
CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA BY MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1010 AM UPDATE...LEADING SHORT WAVE MOVING THROUGH WRN NY WITH
RESULTING CONVECTION SPREADING ACROSS THE FINGER LAKES AND CENTRAL
SRN TIER ATTM. SOME OF THE CONVECTION IS PRODUCING GUSTY WINDS AND
BRIEF HEAVY DOWNPOURS. ACTIVITY IS EXPECTED TO HOLD TOGETHER AND
SPREAD ACROSS THE REGION DURING THE LATE MORNING AND AFTERNOON
HOURS. WILL CONTINUE TREND OF INCREASING POPS INTO THE
CATEGORICAL/LIKELY POP RANGE AND HIGH CHC/LOW LIKELY OVER NE PA.
AS FOR SVR WX POTENTIAL THE MID LEVEL FLOW AND LOW LEVEL
SHEAR/HELICITY ARE VERY FAVORABLE FOR SVR WX BUT THE LIMITING
FACTOR IS THE INSTABILITY. LATEST RAP MODEL GUIDANCE INDICATES
CAPE VALUES OF 400-800 J/KG WHICH SEEMS REASONABLE CONSIDERING THE
ABOUT OF CLOUDS ALREADY OVER THE REGION. A PRE-FRONTAL TROF
CURRENTLY BACK IN OHIO IS PROGGED TO CROSS THE REGION THIS
AFTERNOON AND EVENING WHICH MAY FOCUS ACTIVITY AFTER THIS INITIAL
ACTIVITY. SPC LATEST UPDATE KEEPS MUCH OF THE AREA IN SLIGHT RISK,
IF SUNNY PERIODS DEVELOP THIS AFTERNOON IT COULD GET INTERESTING.
BASED ON ENV WINDS AND LACK OF SIGNIFICANT CAPE THE MAIN SVR WX
THREAT WOULD BE DAMAGING WINDS. ALONG WITH THE SVR POTENTIAL
AIRMASS IS REALLY JUICY SO ANY CONVECTION TODAY WITH HAVE HEAVY
DOWNPOURS.
PREVIOUS DISC...
AN UNSETTLED PTRN OVER THE NXT FEW DAYS AS STRONG UPR LOW...WITH
S/WV`S PIVOTING ARND IT...DROPS SEWD INTO THE GTLAKES. MDLS TDA
SHOW THE DVLPMNT OF A PRE-FNTL TROF ACRS CNTRL NY AND PA THIS
AFTN...WITH CDFNT MOVG INTO WRN NY.
LOW LVL JET FOCUSES ACRS WRN NY ACRS LAKE ONTARIO INTO THE ST
LAWRENCE WHERE BEST UPR LVL DVRGNC WILL BE LOCATED. BIG QUESTION WILL BE
AMT OF HEATING WE GET TDA. ATTM IT APPEARS THAT SUNSHINE WILL BE
LIMITED WITH ALOT OF CONVECTIVE DEBRIS ACRS THE RGN THIS MRNG. MESO
DATA ACTUALLY SHOWS SFC TEMPS FALLING THIS AFTN ACRS CNTRL NY WITH
PSSG OF A CONVECTIVE LINE. NAM CAPES MAX OUT BETWEEN 500-1000
J/KG. GFS CAPES MUCH LESS GNRLY 250-500. LCL WRF GETS CAPE UP TO
750 J/KG BUT INDICATES A TALL SKINNY CAPE. WIND FIELDS LOOK GOOD
HOWEVER. PRECIPITABLE H20 VALUES APRCHNG 2 INCHES. RUC BRN`S IN
THE SUPERCELL RNG THIS AFTN. FOR NOW...WE WILL INDICATE POTNL FOR
+RA AND GUSTY WINDS WITH TSRA THIS AFTN/EVNG.
ACTIVITY SHUD SLIDE INTO NE PA BY EARLY EVNG...WITH BEST CHCS FOR
SHRA/TSRA PERSISTING ACRS THIS AREA TNGT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
UPR LOW CONTINUE TO DIG INTO THE GTLAKES THIS PD WHILE ASSUMING A
NEUTRAL OR SLIGHTLY NEGATIVELY TILT. MSTR XPCTD TO MOV BACK NWD
AHEAD OF THE NXT S/WV AND SFC FNT LATE MON AND MON NGT. SOME
TIMING DIFFS EMERGE LATE IN THE PD BUT TREND WILL BE FOR IMPRVG
CONDITIONS ACRS THE RGN ON TUE NGT. XCPTN MAY BE ACRS THE POCONOS
AND SRN CATSKILLS WHERE POTNL FOR MDT TO HVY SHRA/TSRA MAY EXIST
AS AS A WAVE OF LOW PRES LIFTS NEWD ALONG THE FNT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
NOON UPDATE...
THE BIG STORY DURING THE LONG TERM FORECAST WILL BE A BROAD UPPER
LEVEL TROF OVER THE EASTERN HALF OF THE US WITH COOLER THAN AVERAGE
TEMPS, AND A POSSIBLE RETURN TO UNSETTLED WEATHER BY THE WEEKEND.
MAINLY DRY WEATHER IS EXPECTED WEDNESDAY NIGHT INTO EARLY FRIDAY.
DURING THIS PERIOD A SHORT WAVE WILL MOVE THROUGH IN THE MEAN FLOW
DURING THE DAY THURSDAY. I CONTINUED A DRY FORECAST BUT A POP UP
SHOWER CAN`T BE RULED OUT THIS DAY AS THE SHORT WAVE MOVES
THROUGH. WITH THE BASE OF THE UPPER LEVEL TROF STILL OVER CENTRAL
TX, WE AREN`T QUITE OUT OF THE WOODS FOR MORE PRECIPITATION AS WE
HEAD TOWARD THE WEEKEND. AS THIS TROF MOVES EAST OVER THE
SOUTHEASTERN US, A DEEP SOUTHWEST FLOW WILL DEVELOP AND TRANSPORT
MOISTURE UP THE ATLANTIC COAST. THE TIMING AND HOW FAR NORTH THE
MOISTURE GETS IS STILL VERY MUCH IN QUESTION. THE OLDER RUNS OF THE
GFS ARE ABOUT 24 HOURS FASTER THAN THE EURO, BRINGING IN SHOWERS
BY FRIDAY EVENING WITH THE EURO NOT UNTIL SATURDAY EVENING.
WHATEVER THE CASE IT DOES APPEAR CHANCES WILL INCREASE FOR SHOWERS
OVER THE WEEKEND ITSELF. ON THE FRONT END I PUT IN JUST A 20%
CHANCE FOR SHOWERS IN NEPA FRIDAY BUT SAVE HIGHER CHANCES FOR SAT/SUN.
IF THE PATTERN HOLDS CHANCES FOR RAIN MAY NEED TO BE INCREASED THIS
WEEKEND BUT STILL WAY TOO FAR AND UNCERTAIN AT THIS POINT FOR
ANYTHING MORE THAN THAT.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
12Z UPDATE...
PATCH OF MVFR CIGS HAS DEVELOPED OVER BGM AND AVP THIS MORNING.
EXPECT MVFR CIGS WILL STICK AROUND BETWEEN 12Z AND 13Z BEFORE
SHIFTING SOUTHEAST. EXPECT -TSRA TO DEVELOP ALONG PRE-FRONTAL
TROUGH AFTER 16Z AND CONTINUE THROUGH MOST OF THE AFTERNOON WITH
POTENTIAL MVFR VSBYS AT TIMES. FURTHER SOUTH AT AVP, DO NOT EXPECT
TSRA TO MOVE IN UNTIL 20Z.
IN WAKE OF STORMS, EXPECT LOW-LEVEL MOISTURE TO RESULT IN MVFR
RESTRICTIONS FOR ITH, ELM, BGM AND AVP AFTER 06Z MONDAY. POTENTIAL
EXISTS FOR IFR AT ELM, THUS HAVE TEMPO`D IN 2SM BETWEEN 09Z AND
12Z. AT AVP, SHRA/TSRA MAY CONTINUE THROUGH THE BULK OF THE
OVERNIGHT THOUGH CONFIDENCE IS LOW ON THIS OCCURRING AND IS
DEPENDENT ON HOW IMPENDING WAVE TRACKS.
WINDS 3-8 KTS FROM THE SOUTH WILL BECOME GUSTY OUT OF THE SW THIS
AFTERNOON THEN DIMINISH WITH SUNSET AFTER 00Z.
OUTLOOK...
MON THROUGH TUE NGT...POTENTIAL RESTRICTIONS FROM SHRA/TSRA.
WED/THUR...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RRM
SHORT TERM...
LONG TERM...HEDEN
AVIATION...PVN
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
349 PM EDT SUN JUL 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL LINGER OFFSHORE TONIGHT AND MONDAY AS A TROUGH OF LOW
PRESSURE DEVELOPS INLAND. A COLD FRONT WILL MOVE INTO THE AREA ON TUESDAY
AND BECOME STATIONARY NEAR THE COAST WEDNESDAY AND LINGER JUST OFFSHORE INTO
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 330 PM SUNDAY...A FEW ISOLATED SHOWERS HAVE DEVELOPED OVER
THE SOUTHERN COASTAL SECTIONS PER THE 3KM HRRR AND NSSL WRF MODEL.
ANY SHOWERS SHOULD DISSIPATE FAIRLY QUICKLY LATER IN THE EVENING
WITH LOSS OF HEATING. WITH A MODERATE SOUTHWEST FLOW...MIN TEMPS
TONIGHT WILL BE IN THE MUGGY LOW/MID 70S.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
AS OF 330 PM SUNDAY...THE SURFACE PIEDMONT TROUGH WILL SHARPEN
OVER THE CENTRAL PORTION OF THE STATE AS WARM MOIST SOUTHWEST
WINDS CIRCULATE AROUND HIGH PRESSURE CENTERED WELL OFFSHORE. WITH
A DIFFLUENT MID-LEVEL HEIGHT FIELD...FORCING WILL REMAIN LIMITED
TO THE SEA BREEZE AND DIFFERENTIAL HEATING BOUNDARIES AND WILL
FORECAST THE TYPICAL 30 PCT POP INLAND WITH 20 PCT ALONG THE COAST
DURING THE AFTERNOON AND EVENING HOURS MONDAY. TEMPERATURES WILL
BE ON THE HOT SIDE MONDAY WITH LOWER TO PERHAPS SOME MID 90S WELL
INLAND WITH UPPER 80S NEAR THE COAST.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AS OF 330 PM SUN...A LONG WAVE TROUGH ACROSS THE EASTERN HALF OF THE
CONUS WILL BE THE SYNOPTIC REGIME THROUGH THE PERIOD. A STRONG
SHORTWAVE WILL BE LOCATED ACROSS THE WESTERN GREAT LAKES MON THAT
WILL ROTATE AROUND THE BASE OF THE UPPER TROUGH TUES HELPING TO PUSH
LOWER HEIGHTS TOWARDS THE REGION FROM THE NORTHWEST. A SURFACE LOW
LOOKS TO FORM ACROSS THE SOUTHERN GREAT LAKES WHICH WILL DRAG A SLOW
MOVING COLD FRONT INTO THE REGION TUES INTO WED. THE RIDGE ALONG THE
SOUTHEASTERN COAST WILL BE SHUNTED WELL OFFSHORE TUES THOUGH IT WILL
HELP FOCUS A RICH SOUTHWESTERLY MOISTURE STREAM FROM THE GULF OF
MEXICO AND SOUTHWESTERN ATLANTIC OCEAN TUES THROUGH WED. THE COLD
FRONT WILL APPROACH LATE TUES AND MOVE INTO EASTERN NC WED. FORECAST
SOUNDINGS INDICATE PWATS FALLING TO AROUND 1.50 INCHES MON NIGHT
THEN RAMPING BACK ABOVE 2 INCHES LATE TUES INTO EARLY WED.
MAINTAINED TREND OF INCREASING POPS MON NIGHT THROUGH TUES...TO
LIKELY BY TUES AFTERNOON THROUGH TUE NIGHT. MAX TEMPS WILL FALL A
FEW DEGREES TUES DUE TO INCREASED CLOUDS INHIBITING MAXIMUM
INSOLATION...THOUGH LOW LEVEL THICKNESSES REMAIN ROUGHLY 1425 METERS
TUES. BEST CHANCE FOR SEVERE STORMS APPEARS TO BE TUES AFTERNOON
INTO EVENING WHEN SLIGHTLY GREATER SHEAR EXISTS ACROSS THE REGION
AND MOISTURE REMAINS ABUNDANT. LAYER MOISTURE CONVERGENCE OF AROUND
17 G/KG AND PWATS ABOVE 2 IN WILL BE MAXIMIZED TUE NIGHT PER 13/12Z
SO EXPECT HEAVIEST AND WIDESPREAD PRECIP TO FALL THEN WHEN LIKELY
POPS PERSIST.
THE COLD FRONT WILL BE SLOW TO PUSH OFFSHORE WED BUT HAVE CONTINUED
SLOWLY DECREASING POPS FROM WEST TO EAST...AS WE WILL LIKELY BE ON
THE WEST SIDE OF THE STALLED BOUNDARY BY 00Z THURS. LOW LEVEL
THICKNESSES FALL TO AROUND 1405-1410 WED WHICH YIELDS TEMPS IN THE
LOW/MID 80S INLAND WITH PLENTIFUL LINGERING CLOUD COVER...TO LOW 80S
ALONG THE COAST.
STILL DIFFERENCES APPEAR IN THE EXTENDED RANGE GUIDANCE WITH REGARDS
TO THE SFC AND UPPER AIR PATTERN BEGINNING THURS AND LASTING THROUGH
THE WEEKEND. 13/12Z ECMWF KEEPS EASTERN NC MOSTLY DRY...ON THE
WESTERN SIDE OF THE STALLED FRONTAL BOUNDARY THURS INTO FRI WITH DRY
HIGH PRES RIDGING IN FROM THE NORTHEAST UNDER E TO NE SFC
WINDS...WHILE THE GFS SHIFTS THE BOUNDARY BACK INLAND WITH A SERIES
OF WEAK SURFACE WAVES FORMING ALONG THE STALLED FRONT. TAKING A LOOK
AT THE ENSEMBLE SUITE...THERE IS LOTS OF SPREAD AMONGST THE 13/00Z
ECM ENSMOS WITH REGARDS TO POPS...AND 13/12Z NAEFS FOLLOWS SUITE.
GIVEN UNCERTAINTY THIS FAR OUT IN TIME...CANNOT RULE OUT GFS
SCENARIO THUS MAINTAINED THE SLIGHT CHANCE TO LOW CHANCE POPS THUR
THROUGH FRI. LONG TERM MODEL SUITE INDICATES THE STALLED BOUNDARY
WILL LIFT NORTH THROUGH THE REGION SAT...LEADING TO AT LEAST SCT
CHANCES FOR PRECIP NEXT WEEKEND AS A MOIST SW FLOW REGIME REDEVELOPS.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /TONIGHT AND MONDAY/...
AS OF 130 PM SUN...PLEASANT FLYING CONDITIONS OVER THE PERIOD
WITH HIGH PRESSURE IN CONTROL ACROSS THE REGION. SOME HIGH CLOUDS
NOTED ON VISIBLE WITH DIURNAL CU BEGINNING TO DEVELOP. SOUTHERLY
FLOW BETWEEN 5-8KTS THROUGH THE AFTERNOON. ANTICIPATE SOME
ISOLATED SHOWERS/THUNDERSTORMS TO INITIATE ALONG THE SEA
BREEZE...BUT GIVEN LIMITED SPATIAL COVERAGE WILL KEEP OUT OF THE
TAFS. LOW LEVEL CLOUDS WILL ERODE LATER THIS AFTERNOON WITH LOSS
OF HEATING. MAINLY CLEAR OVERNIGHT WITH SOME HIGH CLOUDS MOVING
INTO THE REGION FROM THE WEST AHEAD OF THE NEXT SYSTEM. FOG
FORMATION WILL BE LIMITED OVERNIGHT GIVEN SUFFICIENT BOUNDARY
LAYER MIXING. THERE MAY BE A PERIOD OF LIGHT FOG AT ISO AS WINDS
MAY DECOUPLE IN THIS AREA...BUT CONFIDENCE IS LOW ELSEWHERE.
SOUTHERLY FLOW CONTINUES UNDER HIGH CLOUDS MONDAY. DIURNAL CU WILL
DEVELOP BY AFTERNOON.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM SUN...INC CHANCES FOR RAIN AND THUNDERSTORMS AND SUB
VFR CONDITIONS LATE MON THROUGH WED...WITH BEST CHANCES FOR
WIDESPREAD RAIN AND LOW CIGS TUE NIGHT. DRIER CONDITIONS EXPECTED
WED NIGHT THROUGH THUR AS HIGH PRES BUILDS INTO THE REGION.
&&
.MARINE...
SHORT TERM /TONIGHT AND MONDAY/...
AS OF 340 PM SUNDAY...WITH A SHARPENING TROUGH INLAND AND HIGH
PRESSURE OFFSHORE...EXPECT INCREASING MAINLY S/SW WINDS THROUGH
THE SHORT TERM PERIOD. WINDS SHOULD GENERALLY BE 10 TO PERHAPS 15
KNOTS TONIGHT THEN WILL INCREASE TO 15 TO 20 KNOTS OVER ALOT OF
THE COASTAL WATERS AND SOUNDS ON MONDAY. PER LOCAL NWPS/SWAN
MODEL...SEAS WILL GENERALLY BE 2 TO 4 TONIGHT AND WILL INCREASE TO
3 TO 5 FEET TOMORROW WITH THE INCREASING WINDS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 345 PM SUN...THE GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND A
SHARPENING SURFACE TROUGH OVER THE PIEDMONT WILL LEAD TO MODERATE
SOUTHWEST WINDS THROUGH MIDWEEK. ANTICIPATE 15 TO 20 KNOT WINDS WITH
SEAS GENERALLY 3 TO 5 FEET...WITH SOME POSSIBLE 6 FOOT SETS TUE
NIGHT ACROSS THE FAR OUTER CENTRAL/SOUTHERN WATERS. WINDS WILL
LIKELY BACK TO A MORE EASTERLY DIRECTION OVER THE NORTHERN WATERS BY
WEDNESDAY NIGHT AND THEN ALL WATERS BY THURSDAY AS THE FRONTAL
BOUNDARY PUSHES OFFSHORE. WINDS WILL BE LIGHT AS THE FRONT REMAINS
NEAR OR OVER THE WATERS THUR. THERE IS SOME UNCERTAINTY WITH WIND
DIRECTION LATE THUR INTO FRI...AS SOME GUIDANCE INDICATES A RETURN
TO SOUTH WINDS AS EARLY AS THUR. HAVE TRENDED WITH A MORE EASTERLY
WIND REGIME THROUGH FRI HOWEVER...THOUGH EITHER WAY...WINDS WILL BE
FAIRLY LIGHT IN THE 5-10 KT RANGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/LEP
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
129 PM EDT SUN JUL 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND OVER THE AREA FROM OFFSHORE THROUGH
MONDAY. A COLD FRONT WILL MOVE INTO THE AREA ON TUESDAY AND
BECOME STATIONARY THROUGH MID WEEK. THE COLD FRONT WILL PUSH
OFFSHORE AND WEAKEN BY THURSDAY.
&&
.NEAR TERM /TODAY/...
AS OF 1 PM SUNDAY...A FEW ISOLATED SHOWERS AND A POSSIBLE EMBEDDED
TSTM IS POSSIBLE JUST INLAND...MAINLY SOUTH OF HIGHWAY 70 THIS
AFTERNOON PER LATEST HRRR AND NSSL WRF MODELS. ALREADY A BIT OF
ACTIVITY AROUND THE WILMINGTON AREA AT THIS TIME. DID RAISE MAX
TEMPS OVER THE OUTER BANKS A COUPLE OF DEGREES BASED ON CURRENT
OBSERVATIONS...OTHERWISE NO BIG CHANGES.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM SUNDAY...WARM AND DRY CONDITIONS TONIGHT WITH LIGHT
S-SW WINDS KEEPING TEMPS SEVERAL DEGS WARMER THAN SUN MORNING. LOWS
FROM LOWER 70S INLAND TO MID-UPR 70S COAST.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
AS OF 345 AM SUN...TYPICAL SUMMERTIME PATTERN WILL BE IN PLACE
MON WITH RIDGE SURFACE AND ALOFT CENTERED OFF THE SOUTHEASTERN
COAST...AND WEAK PIEDMONT TROUGH ACROSS THE CAROLINAS. WILL
MAINTAIN PREVIOUS TREND OF SLIGHT CHANCE POPS OFF THE COAST WHERE
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ALONG/NEAR THE GULF
STREAM...TRANSITIONING TO SLIGHT CHANCE POPS INLAND WITH MODEST
INSTABILITY DURING THE AFTERNOON HOURS. SHEAR REMAINS NIL SO DO
NOT EXPECT SEVERE WX AT THIS TIME THOUGH CANNOT COMPLETELY RULE
OUT. TEMPS WILL BE A FEW DEGREES ABOVE NORMAL FOR MAX TEMPS WITH
HIGHS 92-95 F INLAND AND 82-84 F ALONG THE COAST.
A STRONG UPPER LEVEL TROUGH WILL DIG SOUTH THROUGH THE NORTHERN
GREAT LAKES MON AND TUES. A STRONG SHORTWAVE WILL BE LOCATED
NEAR WISCONSIN MON THAT WILL ROTATE AROUND THE BASE OF THE UPPER
TROUGH TUES HELPING TO PUSH LOWER HEIGHTS TOWARDS THE REGION FROM
THE NORTHWEST. A SURFACE LOW LOOKS TO FORM ACROSS THE SOUTHERN
GREAT LAKES WHICH WILL DRAG A SLOW MOVING COLD FRONT INTO THE
REGION TUES INTO WED. THE RIDGE ALONG THE SOUTHEASTERN COAST WILL
BE SHUNTED WELL OFFSHORE TUES THOUGH IT WILL HELP FOCUS A RICH
SOUTHERLY MOISTURE STREAM FROM THE GULF OF MEXICO AND SOUTHWESTERN
ATLANTIC OCEAN TUES THROUGH WED. THE COLD FRONT WILL APPROACH LATE
TUES AND MOVE INTO EASTERN NC WED. FORECAST SOUNDINGS INDICATE
PWATS FALLING TO AROUND 1.50 INCHES MON NIGHT THEN RAMPING BACK
ABOVE 2 INCHES TUES INTO WED. MAINTAINED TREND OF INCREASING POPS
MON NIGHT THROUGH TUES...TO LIKELY BY TUES AFTERNOON. MAX TEMPS
WILL FALL A FEW DEGREES TUES DUE TO INCREASED CLOUDS INHIBITING
MAXIMUM INSOLATION...THOUGH LOW LEVEL THICKNESSES REMAIN ROUGHLY
1425 METERS MON AND TUES. BEST CHANCE FOR SEVERE STORMS APPEARS TO
BE TUES AFTERNOON WHEN SLIGHTLY GREATER SHEAR EXISTS ACROSS THE
REGION AND MOISTURE REMAINS ABUNDANT.
THE COLD FRONT WILL BE SLOW TO PUSH OFFSHORE WED BUT HAVE TRENDED
POPS DOWN SLIGHTLY FROM PREVIOUS FORECAST FOR WED AND WED NIGHT...AS
WE WILL LIKELY BE ON THE WEST SIDE OF THE STALLED BOUNDARY BY 18Z-
00Z THURS. LOW LEVEL THICKNESSES FALL TO AROUND 1405-1410 WED
WHICH YIELDS TEMPS IN THE MID 80S INLAND TO LOW 80S ALONG THE
COAST. SOME DIFFERENCES APPEAR IN THE EXTENDED RANGE GUIDANCE
BEGINNING THURS AFTERNOON THROUGH THE WEEKEND. 00Z ECMWF KEEPS
EASTERN NC MOSTLY DRY...ON THE WESTERN SIDE OF THE STALLED
BOUNDARY THURS NIGHT INTO FRI...WHILE THE 00Z GFS SHIFTS THE
BOUNDARY BACK INLAND THURS NIGHT...WITH A SERIES OF WEAK SURFACE
WAVES FORMING ALONG THE STALLED BOUNDARY. GIVEN UNCERTAINTY THIS
FAR OUT IN TIME...CAN NOT RULE OUT GFS SCENARIO THUS TRIED TO
BLEND PREVIOUS FORECAST WITH 00Z GFS/ECMWF WHICH MEANS A SLIGHT
CHANCE/CHANCE OF SHOWERS AND THUNDERSTORMS THURS NIGHT THROUGH
FRI. GUIDANCE INDICATES THE STALLED BOUNDARY WILL LIFT NORTH
THROUGH THE REGION SAT...LEADING TO INCREASED CHANCES FOR PRECIP
SAT/SAT AFTERNOON.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 18Z MONDAY/...
AS OF 130 PM SUN...PLEASANT FLYING CONDITIONS OVER THE PERIOD
WITH HIGH PRESSURE IN CONTROL ACROSS THE REGION. SOME HIGH CLOUDS
NOTED ON VISIBLE WITH DIURNAL CU BEGINNING TO DEVELOP. SOUTHERLY
FLOW BETWEEN 5-8KTS THROUGH THE AFTERNOON. ANTICIPATE SOME
ISOLATED SHOWERS/THUNDERSTORMS TO INITIATE ALONG THE
SEA BREEZE...BUT GIVEN LIMITED SPATIAL COVERAGE WILL KEEP OUT OF
THE TAFS. LOW LEVEL CLOUDS WILL ERODE LATER THIS AFTERNOON WITH
LOSS OF HEATING. MAINLY CLEAR OVERNIGHT WITH SOME HIGH CLOUDS
MOVING INTO THE REGION FROM THE WEST AHEAD OF THE NEXT SYSTEM. FOG
FORMATION WILL BE LIMITED OVERNIGHT GIVEN SUFFICIENT BOUNDARY LAYER
MIXING. THERE MAY BE A PERIOD OF LIGHT FOG AT ISO AS WINDS MAY
DECOUPLE IN THIS AREA...BUT CONFIDENCE IS LOW ELSEWHERE. SOUTHERLY
FLOW CONTINUES UNDER HIGH CLOUDS MONDAY. DIURNAL CU WILL DEVELOP
BY AFTERNOON.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 AM SUN...WITH WEAK RIDGING...EXPECT GENERALLY VFR
CONDITIONS MONDAY AS ANY CONVECTION WILL BE LIMITED TO THE SEA
BREEZE IN THE AFTERNOON AND EVENING. A STALLED FRONTAL BOUNDARY
AND DEEP LONGWAVE TROUGH WILL BE IN PLACE TUES THROUGH LATE
WEEK...PROVIDING A DEEP MOISTURE FEED FROM THE GULF. EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS WITH OCCASIONAL MVFR
CEILINGS/VSBYS THROUGH THE REMAINDER OF THE PERIOD WITH ALSO SOME
LOWER VSBYS IN FOG AT NIGHT...PERHAPS IFR/LIFR AT TIMES.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM SUNDAY...LIGHT GENERALLY SE WINDS AT 5 TO 10 KNOTS WILL
BECOME MORE SOUTHERLY DURING THE AFTERNOON AND MAY INCREASE TO 10
TO 15 KNOTS BY LATER THIS AFTERNOON INTO THIS EVENING. SEAS SHOULD
REMAIN AT 2 TO 3 FEET. OVERALL...VERY LITTLE CHANGE TO CURRENT
FORECAST.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 AM SUN...THE GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND
A SHARPENING SURFACE TROUGH OVER THE PIEDMONT WILL LEAD TO MODERATE
SOUTHWEST WINDS THROUGH MIDWEEK. ANTICIPATE 15 TO 20 KNOT WINDS
WITH SEAS GENERALLY 3 TO 4 FEET AND OCCASIONALLY UP TO 5 FEET.
WINDS WILL LIKELY BACK TO A MORE EASTERLY DIRECTION OVER THE
NORTHERN WATERS BY THURSDAY AS THE FRONTAL BOUNDARY PUSHED OFFSHORE.
WINDS WILL ALSO DIMINISH A BIT ON THURSDAY WITH THE STALLED FRONTAL
BOUNDARY OFFSHORE. WINDS SHIFT ENE/E ON THURSDAY BUT REMAIN 10 KT
OR LESS...WHICH WILL RESULT IN SEAS MOSTLY 2-4 FT ACROSS THE WATERS.
LOCAL SWAN/NWPS AND 00Z WAVEWATCH GUIDANCE IN FAIRLY GOOD AGREEMENT
THROUGH THE MEDIUM RANGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...DAG/LEP
MARINE...JBM/CTC/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 PM EDT SUN JUL 13 2014
.SYNOPSIS...
HIGH PRESSURE WILL EXTEND OVER THE AREA FROM OFFSHORE THROUGH
MONDAY. A COLD FRONT WILL MOVE INTO THE AREA ON TUESDAY AND
BECOME STATIONARY THROUGH MID WEEK. THE COLD FRONT WILL PUSH
OFFSHORE AND WEAKEN BY THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM SUNDAY...A FEW ISOLATED SHOWERS AND A POSSIBLE EMBEDDED
TSTM IS POSSIBLE JUST INLAND...MAINLY SOUTH OF HIGHWAY 70 THIS
AFTERNOON PER LATEST HRRR AND NSSL WRF MODELS. ALREADY A BIT OF
ACTIVITY AROUND THE WILMINGTON AREA AT THIS TIME. DID RAISE MAX
TEMPS OVER THE OUTER BANKS A COUPLE OF DEGREES BASED ON CURRENT
OBSERVATIONS...OTHERWISE NO BIG CHANGES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 330 AM SUNDAY...WARM AND DRY CONDITIONS TONIGHT WITH LIGHT
S-SW WINDS KEEPING TEMPS SEVERAL DEGS WARMER THAN SUN MORNING. LOWS
FROM LOWER 70S INLAND TO MID-UPR 70S COAST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 345 AM SUN...TYPICAL SUMMERTIME PATTERN WILL BE IN PLACE
MON WITH RIDGE SURFACE AND ALOFT CENTERED OFF THE SOUTHEASTERN
COAST...AND WEAK PIEDMONT TROUGH ACROSS THE CAROLINAS. WILL
MAINTAIN PREVIOUS TREND OF SLIGHT CHANCE POPS OFF THE COAST WHERE
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ALONG/NEAR THE GULF
STREAM...TRANSITIONING TO SLIGHT CHANCE POPS INLAND WITH MODEST
INSTABILITY DURING THE AFTERNOON HOURS. SHEAR REMAINS NIL SO DO
NOT EXPECT SEVERE WX AT THIS TIME THOUGH CANNOT COMPLETELY RULE
OUT. TEMPS WILL BE A FEW DEGREES ABOVE NORMAL FOR MAX TEMPS WITH
HIGHS 92-95 F INLAND AND 82-84 F ALONG THE COAST.
A STRONG UPPER LEVEL TROUGH WILL DIG SOUTH THROUGH THE NORTHERN
GREAT LAKES MON AND TUES. A STRONG SHORTWAVE WILL BE LOCATED
NEAR WISCONSIN MON THAT WILL ROTATE AROUND THE BASE OF THE UPPER
TROUGH TUES HELPING TO PUSH LOWER HEIGHTS TOWARDS THE REGION FROM
THE NORTHWEST. A SURFACE LOW LOOKS TO FORM ACROSS THE SOUTHERN
GREAT LAKES WHICH WILL DRAG A SLOW MOVING COLD FRONT INTO THE
REGION TUES INTO WED. THE RIDGE ALONG THE SOUTHEASTERN COAST WILL
BE SHUNTED WELL OFFSHORE TUES THOUGH IT WILL HELP FOCUS A RICH
SOUTHERLY MOISTURE STREAM FROM THE GULF OF MEXICO AND SOUTHWESTERN
ATLANTIC OCEAN TUES THROUGH WED. THE COLD FRONT WILL APPROACH LATE
TUES AND MOVE INTO EASTERN NC WED. FORECAST SOUNDINGS INDICATE
PWATS FALLING TO AROUND 1.50 INCHES MON NIGHT THEN RAMPING BACK
ABOVE 2 INCHES TUES INTO WED. MAINTAINED TREND OF INCREASING POPS
MON NIGHT THROUGH TUES...TO LIKELY BY TUES AFTERNOON. MAX TEMPS
WILL FALL A FEW DEGREES TUES DUE TO INCREASED CLOUDS INHIBITING
MAXIMUM INSOLATION...THOUGH LOW LEVEL THICKNESSES REMAIN ROUGHLY
1425 METERS MON AND TUES. BEST CHANCE FOR SEVERE STORMS APPEARS TO
BE TUES AFTERNOON WHEN SLIGHTLY GREATER SHEAR EXISTS ACROSS THE
REGION AND MOISTURE REMAINS ABUNDANT.
THE COLD FRONT WILL BE SLOW TO PUSH OFFSHORE WED BUT HAVE TRENDED
POPS DOWN SLIGHTLY FROM PREVIOUS FORECAST FOR WED AND WED NIGHT...AS
WE WILL LIKELY BE ON THE WEST SIDE OF THE STALLED BOUNDARY BY 18Z-
00Z THURS. LOW LEVEL THICKNESSES FALL TO AROUND 1405-1410 WED
WHICH YIELDS TEMPS IN THE MID 80S INLAND TO LOW 80S ALONG THE
COAST. SOME DIFFERENCES APPEAR IN THE EXTENDED RANGE GUIDANCE
BEGINNING THURS AFTERNOON THROUGH THE WEEKEND. 00Z ECMWF KEEPS
EASTERN NC MOSTLY DRY...ON THE WESTERN SIDE OF THE STALLED
BOUNDARY THURS NIGHT INTO FRI...WHILE THE 00Z GFS SHIFTS THE
BOUNDARY BACK INLAND THURS NIGHT...WITH A SERIES OF WEAK SURFACE
WAVES FORMING ALONG THE STALLED BOUNDARY. GIVEN UNCERTAINTY THIS
FAR OUT IN TIME...CAN NOT RULE OUT GFS SCENARIO THUS TRIED TO
BLEND PREVIOUS FORECAST WITH 00Z GFS/ECMWF WHICH MEANS A SLIGHT
CHANCE/CHANCE OF SHOWERS AND THUNDERSTORMS THURS NIGHT THROUGH
FRI. GUIDANCE INDICATES THE STALLED BOUNDARY WILL LIFT NORTH
THROUGH THE REGION SAT...LEADING TO INCREASED CHANCES FOR PRECIP
SAT/SAT AFTERNOON.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 12Z MONDAY/...
AS OF 730 AM SUNDAY...CURRENT MVFR VSBYS AT KPGV AND KOAJ WILL
IMPROVE TO VFR BY 13Z...THEN VFR EXPECTED ALL SITES THROUGH REST OF
TAF PERIOD. DIURNAL CU/SCU EXPECTED DURING AFTN BUT EXPECT THREAT OF
SHOWERS/TSTMS TO REMAIN S OF AREA. MOSTLY CLEAR CONDITIONS FOR
TONIGHT. SW WINDS WILL INCREASE TO AROUND 10 KT THIS AFTN...AND
REMAIN AROUND 5 KT TONIGHT...LIMITING FOG DEVELOPMENT.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 AM SUN...WITH WEAK RIDGING...EXPECT GENERALLY VFR
CONDITIONS MONDAY AS ANY CONVECTION WILL BE LIMITED TO THE SEA
BREEZE IN THE AFTERNOON AND EVENING. A STALLED FRONTAL BOUNDARY
AND DEEP LONGWAVE TROUGH WILL BE IN PLACE TUES THROUGH LATE
WEEK...PROVIDING A DEEP MOISTURE FEED FROM THE GULF. EXPECT
WIDESPREAD SHOWERS AND THUNDERSTORMS WITH OCCASIONAL MVFR
CEILINGS/VSBYS THROUGH THE REMAINDER OF THE PERIOD WITH ALSO SOME
LOWER VSBYS IN FOG AT NIGHT...PERHAPS IFR/LIFR AT TIMES.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM SUNDAY...LIGHT GENERALLY SE WINDS AT 5 TO 10 KNOTS WILL
BECOME MORE SOUTHERLY DURING THE AFTERNOON AND MAY INCREASE TO 10
TO 15 KNOTS BY LATER THIS AFTERNOON INTO THIS EVENING. SEAS SHOULD
REMAIN AT 2 TO 3 FEET. OVERALL...VERY LITTLE CHANGE TO CURRENT
FORECAST.
LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 345 AM SUN...THE GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND
A SHARPENING SURFACE TROUGH OVER THE PIEDMONT WILL LEAD TO MODERATE
SOUTHWEST WINDS THROUGH MIDWEEK. ANTICIPATE 15 TO 20 KNOT WINDS
WITH SEAS GENERALLY 3 TO 4 FEET AND OCCASIONALLY UP TO 5 FEET.
WINDS WILL LIKELY BACK TO A MORE EASTERLY DIRECTION OVER THE
NORTHERN WATERS BY THURSDAY AS THE FRONTAL BOUNDARY PUSHED OFFSHORE.
WINDS WILL ALSO DIMINISH A BIT ON THURSDAY WITH THE STALLED FRONTAL
BOUNDARY OFFSHORE. WINDS SHIFT ENE/E ON THURSDAY BUT REMAIN 10 KT
OR LESS...WHICH WILL RESULT IN SEAS MOSTLY 2-4 FT ACROSS THE WATERS.
LOCAL SWAN/NWPS AND 00Z WAVEWATCH GUIDANCE IN FAIRLY GOOD AGREEMENT
THROUGH THE MEDIUM RANGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...DAG
AVIATION...JBM/DAG
MARINE...JBM/CTC/DAG
AREA FORECAST DISCUSSION
NWS PORTLAND OR
309 PM PDT SUN JUL 13 2014
.SYNOPSIS... AN UPPER LOW OFF THE NORTH CALIFORNIA COAST WILL MOVE
ACROSS OREGON AND CONTINUE THROUGH TONIGHT. SHOWERS DECREASE FROM
SOUTH TO NORTH AND EAST THROUGH THE NIGHT. OVERALL PATTERN
THEREAFTER WILL BRING COASTAL CLOUDS WITH VARYING AMOUNTS OF INLAND
INTRUSION. INLAND TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH
THE LATTER PART OF THE WEEK.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...MID LEVEL INSTABILITY
UNDER THE MODERATELY DIVERGENT FLOW ALOFT WILL CONTINUE TO MOVE
NORTH AS THE UPPER TROUGH/CLOSED LOW DRIFTS NORTHEAST THIS EVENING
AND OVERNIGHT. LIGHTING ACTIVITY HAS BEEN EVEN MORE CYCLICAL THAN WE
EXPECTED MEANING THERE HAVE BEEN MORE PEAKS AND LULLS IN THE
FREQUENCY OF FLASHES. AS OF 230PM...WE ARE IN ONE OF THE LULLS BUT
EXPECT SURFACE HEATING TO COME BACK INTO PLAY OVER THE NEXT COUPLE
HOURS AS SURFACE TEMPERATURES COME BACK UP SEVERAL DEGREES. ON THAT
NOTE...TEMPERATURES HAVE BEEN SUPPRESSED BY THE HEAVY CONVECTIVE
CLOUD COVER AND EVEN MORE THAN EXPECTED THIS TIME YESTERDAY. AM GLAD
THE DECISION WAS MADE TO TAKE A BREAK FROM THE HEAT ADVISORY.
MOVING FORWARD TONIGHT...THE BEST DYNAMICS CONTINUE TO PUSH NORTH
AND EAST AS THE JET MOVES OFF AND THE UPPER LEVEL FORCING FROM THE
LOW CENTER CONTINUES TO FILL. LOOKS LIKE THE BULK OF STORM ACTIVITY
MAY BE DONE ALONG A LINE FROM EUGENE NORTHWEST THROUGH NEWPORT AND
CONTINUING OFFSHORE, BUT AM VERY LEERY TO TAKE THEM OUT AS THERE ARE
NUMEROUS THIN SPOTS IN THE CLOUDS ALLOWING FOR THE SURFACE
INSTABILITY TO RECHARGE. THE CONTINUED HIGH DEW POINTS WILL MAKE FOR
A RELATIVELY LOW LCL (CLOUD BASE) AND FINALLY COMPLETE THE
TRANSITION TO SURFACE BASED INSTABILITY INSTEAD OF THE HYBRID
SURFACE/ELEVATED REGIME WE ARE CURRENTLY IN. ITS WORTH MENTIONING
THE 19Z HRRR MODEL DOES NOT SUPPORT MUCH OF THE SURFACE HEATING
SCENARIO BUT THEN AGAIN IT ALSO LARGELY MISSED THE ELEVATED
CONVECTION SET UP FROM EARLIER. IT STILL PROVED USEFUL FOR THE VERY
SHORT TERM (0-2 HR) REFLECTIVITY FORECASTING, HOWEVER. BEST STORM
SHEAR WILL STAY OVER THE CASCADES AND FAR NORTH WITH A MODERATE HAIL
THREAT UNDER THE STRONGER STORMS. 1/2 INCH WAS THE LARGEST REPORT
RECEIVED THOUGH WAS NOT NECESSARILY FROM THE ABSOLUTE STORM
CORE.
LATER THIS EVENING WILL SEE THE CONVECTIVE THREAT GET PUSHED TO THE
EXTREME NORTHEAST PORTION OF THE AREA INCLUSIVE OF THE 3 VOLCANO
TRIANGLE (MT ST HELENS, MT HOOD, AND MT ADAMS). SOME LINGERING
SHOWERS APPEAR TO PERSIST FOR THE REST OF THE CASCADES AND THEN
NORTH OF SALEM AND TILLAMOOK. FINAL SHOWER ACTIVITY WILL HANG ON AS
THE UPPER LOW FINALLY LEAVES OUR AREA EARLY TOMORROW MORNING.
EXPECT TO SEE ANOTHER STRATUS INTRUSION COMING UP THE COLUMBIA AND
SEEPING THROUGH THE LANE COUNTY GAPS. EXPECT A STRETCH FROM ROUGHLY
SALEM TO CORVALLIS WILL STAY OUT OF THE STRATUS AS THE NORTH AND
SOUTH SEGMENTS COME TOGETHER OVER THE CASCADE FOOTHILLS.
TEMPERATURES TOMORROW WILL LIKELY RECOVER SIGNIFICANTLY FROM TODAY
AS HEIGHTS RAPIDLY REBUILD AND SKIES CONTINUE TO CLEAR. MAY GET SOME
FAIR WEATHER CUMULUS OVER THE TERRAIN AND SOME SPOTTY CLOUDS OVER
THE VALLEY. STRATUS WILL HAVE A HARD TIME BURNING OFF THE NORTH
COAST BUT SHOULD EASE OFF THE CENTRAL COAST AND REMAIN IN VIEW.
TUESDAY AND WEDNESDAY...WILL BRING WARM AND DRY CONDITIONS WITH
COASTAL STRATUS BACKING SLIGHTLY OFFSHORE DURING THE LATE AFTERNOON
AND EARLY EVENING. /JBONK
.LONG TERM...WEDNESDAY NIGHT THROUGH SATURDAY...NO SIGNIFICANT
CHANGES...PREVIOUS DISCUSSION FOLLOWS. AN UPPER LEVEL TROUGH WILL
SLIDE DOWN THE B.C. AND WASHINGTON COASTS WED NIGHT AND
THURSDAY...JUST CLIPPING NW OREGON. THIS WILL RESULT IN MORE MARINE
CLOUDS AND SOME COOLING FOR THURSDAY. THE TROUGH WILL MOVE OVER THE
AREA ON FRIDAY AND EXPECT SEASONAL TEMPERATURES. THE RIDGE WILL
BUILD SATURDAY FOR MORE WARMING OVER THE AREA. TJ
&&
.AVIATION...SCATTERED HIGH BASED THUNDERSTORMS THIS AFTERNOON WITH
BASES GENERALLY 8 TO 12 THOUSAND FEET. AS THE AIR MASS BECOMES
MORE MOIST EXPECT BASES TO LOWER SOME BUT CIGS SHOULD REMAIN ABOVE
6000 FEET. THE AREA OF THUNDERSTORMS FOCUS WILL SHIFT FROM THE
CENTRAL COAST AND WILLAMETTE VALLEY TO THE NORTHERN WILLAMETTE
VALLEY AND AND SOUTHWEST WASHINGTON DURING THE LATE AFTERNOON AND
EVENING. SOME THUNDERSTORMS WILL CONTAIN SMALL HAIL. MARINE
INVERSION WILL REMAIN IN PLACE ALONG THE COAST AND KEEP IFR AND
AREAS OF LIFR STRATUS ALONG THE COAST AND UP AGAINST THE COAST
RANGE THIS EVENING AND TONIGHT. SOUTHWEST WIND SURGE IS ALREADY
PUSHING STRATUS INTO THE SOUTHERN WILLAMETTE VALLEY. EXPECT CIGS
THERE TO LOWER SOME THIS EVENING AND COULD SOME AREAS OF IFR. IFR
STRATUS WILL SPREAD DOWN THE COLUMBIA RIVER 06-08Z AND REACH KPDX
AROUND 11Z. EXPECT STRATUS TO BREAK OUT IN THE VALLEY ABOUT 19Z.
WITH MUCH MORE SUNSHINE. SCHNEIDER
KPDX AND APPROACHES...NO CHANGES. BROKEN TO OVERCAST MID CLOUDS
WITH VFR CIGS NEXT 24 HRS. HIGH BASED THUNDERSTORMS WILL CONTINUE
OFF AND ON THROUGH 06Z. THERE IS ABOUT A 20 PERCENT CHANCE OF
SMALL HAIL AT THE TERMINAL 23Z-04Z. IFR STRATUS LIKELY TO REACH
THE TERMINAL 11Z- 16Z. SCHNEIDER
&&
.MARINE...UPPER DISTURBANCE MOVING NORTHEAST ACROSS THE NORTH
OREGON AND SOUTH WASHINGTON COASTAL WATERS. ISOLATED THUNDERSTORMS WILL
CONTINUE...SOME WITH SMALL HAIL. DISTURBANCE SHOULD CLEAR THE AREA
AROUND MIDNIGHT. AREAS OF FOG WILL CONTINUE THROUGH MONDAY
MORNING. HIGH PRES WILL REMAIN OVER THE NE PAC TODAY AND
TONIGHT...KEEPING LIGHT WINDS FROM THE NW. NW WINDS LIKELY TO
INCREASE MONDAY AFTERNOON WITH THE PASSAGE OF THE DISTURBANCE AND
INCREASE IN HIGH PRESSURE OFFSHORE WINDS COULD REACH SMALL CRAFT
CRITERIA OVER THE CENTRAL OREGON COASTAL WATERS BY MID TO LATE
AFTERNOON MONDAY. SCHNEIDER
BUOYS ARE NOW SHOWING THE LONG AWAITED WESTERLY LONG PERIOD
SWELL...RUNNING ABOUT 2 TO 3 FEET. MODELS INDICATE THIS WILL
CONTINUE UNTIL MONDAY NIGHT WHEN THE NORTHWEST WINDS GENERATE A
MORE DOMINANT SHORTER PERIOD 7-9 SECOND SWELL. EVEN THOUGH THERE
IS RELATIVELY LOW SWELL...WITH THE LONG PERIOD AND THE VERY STRONG
EBB CURRENT ON THE COLUMBIA RIVER BAR HAVE DECIDED TO ISSUE A
SMALL CRAFT ADVISORY DURING THE STRONG EBB MONDAY MORNING. SCHNEIDER
&&
.FIRE WEATHER...AN UPPER LEVEL DISTURBANCE IS EXPECTED TO BE LOCATED
JUST OFF THE NORTH OREGON COAST BY LATE EVENING AND THEN SHIFT INTO
SOUTH-CENTRAL WASHINGTON BY SUNRISE MONDAY. SHOWER AND THUNDERSTORM
ACTIVITY WILL CONTINUE TONIGHT...BUT FAVORING THE NORTH ZONES.
STRONG AND GUSTY OUTFLOW WIND GUSTS AND SMALL HAIL REMAIN PRIMARY
THREATS WITH ANY STORM. ONSHORE LOW-LEVEL FLOW INCREASES OVERNIGHT
AND MONDAY BEHIND THE DEPARTING SYSTEM. HOWEVER...HIGH PRESSURE
ALOFT STRENGTHENS ONCE AGAIN TUESDAY WHICH WILL RESULT IN A RETURN
TO HOT CONDITIONS. THERE IS THE POSSIBILITY THAT SOME AREAS COULD
GET CLOSE TO 100 DEGREES TUESDAY AFTERNOON. THE HEAT CONTINUES
WEDNESDAY...BUT LONGER RANGE CHARTS HINT AT A MINOR COOLING TREND
DURING THE LATTER HALF OF THE WEEK. WEISHAAR
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR... HEAT ADVISORY FROM 11 AM MONDAY TO 11 PM PDT TUESDAY FOR CASCADE
FOOTHILLS IN LANE COUNTY-CASCADES IN LANE COUNTY-CENTRAL
COAST RANGE OF WESTERN OREGON-CENTRAL COLUMBIA RIVER GORGE-
CENTRAL WILLAMETTE VALLEY-COAST RANGE OF NORTHWEST OREGON-
GREATER PORTLAND METRO AREA-LOWER COLUMBIA-NORTHERN OREGON
CASCADE FOOTHILLS-NORTHERN OREGON CASCADES-SOUTH WILLAMETTE
VALLEY-UPPER HOOD RIVER VALLEY-WESTERN COLUMBIA RIVER GORGE.
WA...HEAT ADVISORY FROM 11 AM MONDAY TO 11 PM PDT TUESDAY FOR CENTRAL
COLUMBIA RIVER GORGE-GREATER VANCOUVER AREA-I-5 CORRIDOR IN
COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS-SOUTH
WASHINGTON CASCADES-WESTERN COLUMBIA RIVER GORGE-WILLAPA
HILLS.
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 5 AM TO 9 AM PDT MONDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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
NWS HOUSTON/GALVESTON TX
316 PM CDT SUN JUL 13 2014
.DISCUSSION...
THE HOT CONDITIONS WILL SLOWLY MODERATE AS RAIN CHANCES INCREASE
DURING THE MIDDLE AND LATTER PART OF THIS WEEK. THIS WILL BE DUE
TO THE APPROACH OF A FRONTAL BOUNDARY OVER NORTH AND EAST TEXAS
AND THE DEVELOPMENT OF A NORTHWESTERLY FLOW ALOFT.
THE UPPER LEVEL LOW THAT HAS BEST BEEN SHOWN AT 200 MB WAS SLOWLY
WORKING ITS WAY WESTWARD INTO FAR SE TEXAS THIS AFTERNOON. THE
NAM HAS DONE A DECENT JOB SO FAR IN DEPICTING THE MOVEMENT OF THE
LOW. ALTHOUGH THE HIGH RESOLUTION HRRR HAS DONE WELL IN SHOWING
THE LOCATION FOR SHOWER AND THUNDERSTORM DEVELOPMENT...THE MODEL
HAS OVERDONE THE COVERAGE. BEST RAINFALL COVERAGE SHOULD STAY TO
THE NORTH AND EAST OF THE CENTER OF THE LOW AS IT TREKS SLOWLY
WESTWARD THIS AFTERNOON. THIS WILL PUT THE BEST CHANCES OVER
LOCATIONS GENERALLY EAST OF INTERSTATE 45. THE SEABREEZE WILL ALSO
CONTRIBUTE TO DEVELOPMENT OVER THE COASTAL AREAS.
THE NAM12 PUSHES THE UPPER LOW TO OVER SE TX TONIGHT AND MONDAY.
THE UPPER LOW WILL SLOWLY SHEAR APART TO BECOME PART OF A LARGER
WEAKNESS DEVELOPING IN THE UPPER LEVEL RIDGE OVER THE SOUTHERN
PLAINS. THE MODELS SLOWLY PUSH THE WEAKNESS EASTWARD MONDAY NIGHT
AND TUESDAY AS THE UPPER LEVEL HIGH OVER THE FOUR-CORNERS AREAS
STRENGTHENS AND DRIFTS SOUTHWARD. THIS WILL SET UP A NORTHWESTERLY
FLOW OVER STATE AND HELP DRIVE A COLD FRONT INTO THE SOUTHERN
PLAINS DURING THE MID WEEK PERIOD. THE MODELS ARE AGREEING WITH
KEEPING THE FRONT GENERALLY OVER NE TEXAS LATE WEDNESDAY AND EARLY
THURSDAY BEFORE SLOWLY PUSHING THE FRONT BACK TO THE NORTH. WOULD
EXPECT THE BEST CHANCES FOR THUNDERSTORMS TO BE OVER THE NORTHERN
AND EASTERN COUNTIES TUESDAY AND WEDNESDAY. FOR THURSDAY INTO
EARLY SATURDAY RAIN CHANCES WILL BECOME MORE WIDESPREAD AS A
SHORTWAVE TROUGH MOVES OVER THE STATE AND A SURFACE BOUNDARY OVER
THE CENTRAL AND NORTHERN PORTIONS OF THE STATE APPROACHES THE
FORECAST AREA.
TWEAKED THE RAIN CHANCES THROUGHOUT THE PERIOD. ALSO FELT THAT
WITH BETTER RAIN CHANCES ON FRIDAY THAT THE DAYTIME HIGH
TEMPERATURE WILL BE MORE MODERATE THAN EARLIER ADVERTISED.
40
&&
.MARINE...
A WEAK PRESSURE GRADIENT WILL MAINTAIN A LIGHT TO OCCASIONALLY
MODERATE ONSHORE FLOW THROUGH MONDAY. A WEAK UPPER LEVEL DISTURBANCE
WILL MOVE OVER COASTAL WATERS FROM THE EAST OVERNIGHT...HOWEVER
SHOWER AND THUNDERSTORM ACTIVITY SHOULD REMAIN FAIRLY ISOLATED.
THE SURFACE PRESSURE GRADIENT WILL GRADUALLY TIGHTEN TUESDAY
ALLOWING FOR A STRENGTHENING OF SURFACE WINDS IN ADVANCE OF AN
APPROACHING FRONTAL BOUNDARY. WINDS SHOULD FROM THE SOUTHWEST ON
TUESDAY... BECOMING MORE SOUTHERLY WEDNESDAY AND THURSDAY AS THE
FRONT STALLS INLAND FROM THE COAST AND LOW PRESSURE SYSTEM DEEPENS
OVER WEST TEXAS. 44
&&
.PREV DISCUSSION... /ISSUED 104 PM CDT SUN JUL 13 2014/
DISCUSSION...
PLEASE SEE 18Z AVIATION DISCUSSION...
AVIATION...
PREVAILING VFR THIS AFTERNOON. ISOLATED SHOWERS AND THUNDERSTORMS
STILL LIKELY AFTER 21Z...HOWEVER THE MAJORITY OF ACTIVITY WILL
REMAIN SOUTH OF THE I-10 CORRIDOR. LEFT VCTS IN THE IAH TAF AFTER
21Z AND CXO AFTER 22Z...HOWEVER CONFIDENCE IS NOT HIGH THAT
THUNDERSTORMS WILL MIGRATE THAT FAR INLAND. WATER VAPOR SATELLITE
IMAGERY SHOWS THAT THE UPPER LEVEL LOW THAT HAD BEEN FORECAST TO
MOVE ACROSS THE AREA TODAY REMAINS OVER THE GULF TO THE SOUTH OF
THE SABINE RIVER. THE UPPER LEVEL RIDGE HAS CONTINUED TO LIMIT
CONVECTION TO THE WEST OF THIS LOW. I MAY REMOVE THE VCTS FROM IAH
AND CXO TAFS AFTER 20Z IF THERE IS NOT BETTER DEVELOPMENT OVER
LAND.
MVFR CIGS POSSIBLE AT RURAL TERMINALS DURING PRE-DAWN HOURS ON
MONDAY. OTHERWISE...PREVAILING VFR CONDITIONS ON MONDAY. LEFT
MENTION OF VCSH/VCTS OUT OF MONDAY TAFS BECAUSE COVERAGE SHOULD BE
VERY SPARSE. 44
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 98 75 95 74 / 10 10 20 30 40
HOUSTON (IAH) 75 97 76 94 75 / 10 20 20 40 30
GALVESTON (GLS) 80 90 80 90 81 / 10 20 20 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...40
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1234 PM CDT SUN JUL 13 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT SUN JUL 13 2014
MAIN SHORT TERM CONCERN IS ON RAIN POTENTIAL TODAY.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED STRONG UPPER RIDGING OVER THE WESTERN U.S. INTO WESTERN
CANADA...WHILE AN ANONYMOUSLY DEEP TROUGH OVER MANITOBA AND NORTHERN
ONTARIO WAS SLOWLY SINKING SOUTH. A PROMINENT DRY SLOT AHEAD OF THE
DESCENDING TROUGH HELPED KICKED THE SHOWERS AND STORMS OUT OF THE
FORECAST AREA BY 03Z LAST EVENING. NORTHWEST FLOW OF 20-35 KT FROM
925MB TO 700MB ALSO WAS BRINGING MUCH DRIER AIR INTO THE AREA...
NOTED BY PRECIPITABLE WATER DOWN TO 1 INCH COMPARED TO AS HIGH AS 2
INCHES AT 00Z. SURFACE DEWPOINTS ARE STILL RELATIVELY HIGH...IN THE
LOW 60S...RESULTING MOSTLY FROM MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. THAT TRAPPING HAS LED TO SOME LOW STRATUS AND FOG
DEVELOPMENT OVERNIGHT. ANOTHER SLUG OF EVEN DRIER AIR WAS EVIDENT
OVER NORTH DAKOTA AND NORTHERN MN WITH PRECIPITABLE WATER AT 0.5
INCH...ALONG WITH SURFACE DEWPOINTS IN THE 40S AND 50S. THIS DRIER
AIR WAS LOCATED BEHIND A COLD FRONT STRETCHING FROM NORTHWEST WI
INTO WEST CENTRAL MN. SOME DYING SHOWERS WERE OVER NORTHWEST WI WITH
THIS FRONT...TIED MOSTLY WITH A SHORTWAVE CROSSING WESTERN LAKE
SUPERIOR. OTHERWISE...THE FRONT IS MOSTLY CLOUD FREE. TEMPERATURE
WISE...850MB TEMPS WERE GENERALLY 13-16C FROM NORTH DAKOTA INTO
WISCONSIN AT 00Z. HOWEVER...5C READINGS WERE SEEN LURKING OVER
CENTRAL MANITOBA WITHIN THE DEEP UPPER TROUGH.
MODELS ARE IN GOOD AGREEMENT DROPPING THE COLD FRONT OVER CENTRAL MN
SOUTHEASTWARD THROUGH THE FORECAST AREA THIS MORNING. DAYTIME
HEATING COMBINED WITH THE LINGERING MOISTURE AROUND WILL LIKELY LEAD
TO A DECENT AMOUNT OF CUMULUS AHEAD OF THE FRONT. ALTHOUGH THE
DETERMINISTIC NAM/GFS/CANADIAN SUGGEST A DRY FRONTAL PASSAGE...NEW
13.00Z ECMWF AS WELL AS THE 13.05Z HRRR AND 3 OF THE 4 HOPWRF
MEMBERS RUN BY THE MPX OFFICE SUGGEST A BAND OF SHOWERS WILL OCCUR
WITH THE FRONT. DEVELOPMENT TIME OCCURS AROUND 14Z / 9 AM AND SINKS
TO THE SOUTH OUT OF THE AREA BY 19Z / 2 PM. INCLUDED A 20 PERCENT
CHANCE AND ISOLATED SHOWERS FOR THIS SHOWER POTENTIAL. DID NOT PUT
ANY THUNDER WITH IT AS THE CAPE IS ONLY PROGGED AT 100-200 J/KG AND
ALL OF THE CAPE IS BELOW THE FREEZING LEVEL. AS THE FRONT PASSES AND
THE LOWER PRECIPITABLE WATER ADVECTS IN BEHIND IT...EXPECT THE
CUMULUS TO GRADUALLY DISSIPATE ALONG WITH DEWPOINTS DROPPING THROUGH
THE 50S. NORTHWEST WINDS SHOULD BECOME A BIT BREEZY TOO IN THE WAKE
OF THE FRONTAL PASSAGE GIVEN A FAVORABLE DEEPER MIXING ENVIRONMENT.
ATTENTION TONIGHT TURNS TO A POTENT SHORTWAVE WITHIN THE DEEP TROUGH
LOCATED IN NORTHEAST MANITOBA. MODELS DROPS THIS SHORTWAVE OVER THE
NORTHERN HALF OF MN BY 12Z...WITH AN UPPER LOW ALSO INDICATED AT
500MB. DPVA AHEAD OF THIS FEATURE COMBINED WITH THE MOIST AND MUCH
COOLER AIR WITHIN THE TROUGH IS EXPECTED TO SPREAD SHOWERS INTO
NORTHWEST WI BY 12Z MONDAY. BELIEVE THESE SHOULD STAY AWAY FROM
TAYLOR COUNTY BEFORE 12Z. SOME CLOUD INCREASE IS LIKELY NORTH OF I-
90 AFTER MIDNIGHT...THOUGH. A SECONDARY COLD FRONTAL PASSAGE SHOULD
COME INTO AND POSSIBLY THROUGH THE AREA BY 12Z AS WELL. ADVECTION
BEHIND THIS FRONT WILL ALLOW TEMPERATURES TO DIP INTO THE 50S...WITH
EVEN A FEW UPPER 40S POSSIBLE IN CENTRAL WI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 259 AM CDT SUN JUL 13 2014
THE MAIN ISSUE HERE IN THE LONG TERM IS WITH THE TRACK OF THE UPPER
LOW IN NORTHERN MN AT 12Z MONDAY. THE ECMWF HAS BEEN PERSISTENT AS A
SLOWER...MORE AMPLIFIED SOLUTION...TAKING THE UPPER LOW ACROSS
CENTRAL AND NORTHERN WI MONDAY EVENING AND ACROSS LOWER MICHIGAN ON
TUESDAY. HOWEVER...THE 13.00Z CANADIAN/NAM/GFS ALL ARE IN STEP WITH
EACH OTHER SHOWING A TRACK ACROSS UPPER MICHIGAN ON MONDAY...AND
INTO EAST CENTRAL ONTARIO ON TUESDAY. THESE DIFFERENCES ARE
SIGNIFICANT AS IT IMPACTS THE LOCATION OF DPVA AND DIURNALLY
ENHANCED SHOWER POTENTIAL...ALONG WITH HOW COLD TEMPERATURES WILL BE
MONDAY AND TUESDAY. IT SHOULD BE NOTED THAT THE 13.00Z ECMWF HAS
TRENDED JUST SLIGHTLY TOWARDS THE CANADIAN/NAM/GFS. TO HANDLE THE
DIFFERENCE BETWEEN THESE TWO SOLUTIONS...HAVE DECIDED TO STAY PRETTY
CLOSE TO THE PREVIOUS FORECAST...WHICH WOULD BE IN-LINE WITH A MODEL
CONSENSUS IDEA.
FOR MONDAY...WE SHOULD GRADUALLY SEE SHOWER COVERAGE INCREASE
THROUGH THE DAY AS THE UPPER LOW AND ASSOCIATED COLD AIR ALOFT
APPROACH. THE MOST NUMEROUS COVERAGE IS ANTICIPATED NORTH OF HIGHWAY
29 CLOSER TO THE UPPER LOW. THESE SHOWERS SHOULD MOSTLY DIMINISH
MONDAY NIGHT DUE TO THE LOSS OF DAYTIME HEATING. TUESDAYS RAIN
CHANCES ARE A BIT MORE QUESTIONABLE NOW AFTER SEEING THE 13.00Z
ECMWF. THE FLOW IS STILL CYCLONIC INTO THE REGION...BUT DRY AIR IS
ADVECTING IN AT THE SAME TIME. THE CANADIAN/GFS/NAM ARE ALL
DRY...AND NOW THE ECMWF ONLY HAS SOME LIGHT QPF BETWEEN 12-18Z
TUESDAY BEFORE DRYING OUT. HAVE THEREFORE TRENDED PRECIPITATION
CHANCES LOWER A BIT AND DRIED OUT LOCATIONS WEST OF THE MISSISSIPPI
RIVER. REGARDING TEMPERATURES...850MB TEMPS PLUMMET TO 4-6C IN THE
MORNING WHICH WILL KEEP HIGHS MOSTLY IN THE 60S. THE LONE EXCEPTION
TO THAT IS IN FAR SOUTHWEST WI WHERE THE COLDER AIR ENTERS LAST AND
HAS MORE SUN POTENTIAL IN THE MORNING. WITH LESS SHOWER POTENTIAL ON
TUESDAY...HAVE RAISED HIGHS SLIGHTLY BUT THEY ARE STILL A FAR CRY
FROM NORMAL.
BENIGN WEATHER CONTINUES TO BE THE RULE AFTER TUESDAY. UPPER
TROUGHING DOMINATES MUCH OF THE EASTERN U.S. WEDNESDAY INTO THURSDAY
WITH THE FORECAST AREA ON THE BACK SIDE OF THE TROUGH. THIS FAVORS
SUBSIDENCE ALOFT AND DRYING HIGH PRESSURE AT THE SURFACE. THE GFS
CONTINUES TO SPLATTER LIGHT QPF AROUND DURING THE AFTERNOON AND
EVENINGS AS A RESULT OF TOO MUCH EVAPOTRANSPIRATION. AS WE HEAD INTO
FRIDAY AND SATURDAY...500MB HEIGHTS LOOK TO RISE ACROSS MUCH OF THE
EASTERN U.S. AS THE TROUGH LIFTS OUT. IN FACT...WE COULD EVEN BE
UNDER UPPER RIDGING BY SATURDAY AS A SHORTWAVE TROUGH SLIDES ACROSS
THE NORTHERN ROCKIES. THIS PATTERN HEADING INTO SATURDAY FAVORS A
CONTINUATION OF DRY CONDITIONS ALONG WITH A NICE WARMING TREND
TOWARDS CLOSER TO NORMAL. MUCH OF THE MORE HUMID AIR LOOKS TO BE
STUCK ACROSS THE SOUTHERN U.S. THANKS TO THE COLD/DRY AIR FROM
EARLIER THIS WEEK DROPPING ALL THE WAY DOWN TO THE GULF COAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1234 PM CDT SUN JUL 13 2014
SECONDARY COLD FRONT HAS PUSHED THROUGH KRST/KLSE THIS AFTERNOON
WITH SCATTERED CUMULUS DEVELOPING ITS WAKE. EXPECTING MOST OF
THIS...ALONG WITH THE 20KT GUSTS ACROSS SOUTHERN MINNESOTA...TO BE
DIURNAL AND SUBSIDE TOWARD SUNSET. THE MAIN ENERGY ASSOCIATED WITH
THE UPPER LEVEL SHORTWAVE TROUGH ARRIVES MONDAY AFTERNOON...AND
WITH IT ANOTHER ROUND OF SCATTERED TO BROKEN VFR CUMULUS IS
EXPECTED. BASES LOOK TO BE BETWEEN 3 AND 5 KFT...AS OBSERVED TODAY
UPSTREAM. SOME SHOWERS WILL BE POSSIBLE AT THE TAF SITES...BUT
MORE SO AFTER 18Z AND TO THE NORTHEAST...SO HAVE KEPT CURRENT TAF
PERIOD DRY.
&&
.CLIMATE...
ISSUED AT 259 AM CDT SUN JUL 13 2014
RECORD COOL HIGH TEMPERATURES ARE POSSIBLE MONDAY AND TUESDAY AS AN
UNSEASONABLY COLD AIRMASS SETTLES OVER THE UPPER MISSISSIPPI RIVER
VALLEY.
FOR LA CROSSE...
MONDAY....FORECAST HIGH 68. RECORD 65 IN 1994
TUESDAY...FORECAST HIGH 70. RECORD 68 IN 1962
FOR ROCHESTER...
MONDAY....FORECAST HIGH 64. RECORD 64 IN 1952
TUESDAY...FORECAST HIGH 67. RECORD 67 IN 1962
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....ZT
CLIMATE......AJ