Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/14/14
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
1108 AM MST TUE AUG 12 2014
...POTENTIAL FOR LOCALIZED FLASH FLOODING TODAY AND TONIGHT ACROSS
MUCH OF THE AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
CONVECTIVELY ACTIVE DAY HAS STARTED TO RAMP UP SOMEWHAT THIS MORNING
AS FAVORABLE ATMOSPHERIC DYNAMICS COMBINE WITH A VERY MOIST
ENVIRONMENT. THE PRIMARY INVERTED TROUGH/VORTICITY CENTER WAS
PROPAGATING NORTH NEARING THE INTERNATIONAL BORDER SOUTHWEST OF
TUCSON...WHILE A LEADING CONVECTIVELY GENERATED VORTICITY MAX WAS
SUPPORTING DEVELOPING CONVECTION NEAR THE YUMA AREA. 12Z KPSR AND
KTWC SOUNDINGS DEPICTED DEEP SELY MOIST FLOW THROUGH THE LOWER AND
MIDDLE TROPOSPHERE CHARACTERIZED BY PWATS 1.75 INCHES AND LOW LEVEL
MIXING RATION 11-12 G/KG (NEAR 2 STANDARD DEVIATIONS ABOVE AVERAGE).
OBJECTIVE ANALYSIS SUGGESTS PWATS IN EXCESS OF 2 INCHES ADVECTING
NORTH TOWARDS THE CWA...WHILE DIFLUENCE ALOFT AND FORCED ASCENT
INCREASE ACROSS THE REGION.
AT 9AM...SFC TEMPERATURES HAVE RISEN INTO THE MID 80S TO MID 90S
(OUTSIDE OF THUNDERSTORMS THAT HAVE CONTINUED SINCE EARLIER IN THE
DAY) DESPITE THE THIN VEIL OF CIRRUS FROM EARLIER SONORAN COMPLEX.
BASED ON 12Z SOUNDING DATA AND FORECAST NAM-WRF BUFR
SOUNDINGS...ONCE TEMPERATURES REACH 98-100 DEGREES THE ENVIRONMENT
WILL BECOME CONVECTIVELY UNSTABLE (MLCAPES NEARING 1000 J/KG) WITH
LITTLE TO NO INHIBITION. WHILE LAPSE RATES ARE NOT PARTICULARLY
STEEP...TALL SKINNY CAPE PROFILES WITH THICK MOISTURE SUPPORT
LOCALLY HEAVY RAIN PRODUCING CELLS (AND POTENTIALLY A COUPLE
MOISTURE LOADED UPDRAFT/DOWNBURST CELLS). WILL CONTINUE FLASH FLOOD
WATCH BASED MOSTLY ON PRECIP RATE EXPECTATION OVER POPULATION
CENTERS AS CELL PROPAGATION MAY PRECLUDE A WIDESPREAD FLOOD THREAT
(UNLESS LOCAL TRAINING ECHOES SET UP). OTHERWISE...MADE MINOR
ADJUSTMENTS TO TEMPS AND POPS FOR THE REMAINDER OF THE MORNING BASED
ON CURRENT TRENDS.
&&
.PREVIOUS DISCUSSION...
/605 AM MST TUE AUG 12 2014/
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES
ARE A GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR.
HIGH TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX
AREA. BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS SE ARIZONA
THROUGH NOON AND THEN MOVE INTO THE PHOENIX AREA AFFECTING TERMINALS
SOMETIME FROM EARLY AFTERNOON THROUGH EARLY EVENING. WILL LIKELY ADD
IN A TEMPO OR PREDOMINANT GROUP FOR THUNDERSTORMS ONCE WE HAVE A
BETTER TIMEFRAME OF STORMS MOVING THROUGH THE AREA. HAVE FAIRLY HIGH
CONFIDENCE IN AT LEAST BRIEF TIME...LESS THAN AN HOUR MOST
LIKELY...OF MVFR CIGS/VSBYS DUE TO SHOWERS AND STORMS MOVING THROUGH
THE METRO AREA. EXPECTING A BREAK IN THE RAIN FROM AROUND MID
EVENING THROUGH MUCH OF THE OVERNIGHT...BUT CIGS AROUND 6-8K FEET
SHOULD PERSIST. ANOTHER ROUND OF SHOWERS AND POSSIBLY A THUNDERSTORM
OR TWO IS EXPECTED AGAIN DURING THE DAYTIME WEDNESDAY.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS AFTERNOON WITH
A FAIRLY GOOD CHANCE OF AFFECTING BOTH KIPL AND KBLH AT LEAST FOR A
BRIEF TIME. CHANCES FOR STORMS WILL DIMINISH BY EARLY EVENING WITH
LINGERING CIGS AROUND 8K LIKELY LASTING JUST PAST MIDNIGHT. GRADUAL
CLEARING IS EXPECTED BY SUNRISE WEDNESDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND.
THE BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A 10-25
PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
AVIATION....KUHLMAN
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
915 AM MST TUE AUG 12 2014
...POTENTIAL FOR LOCALIZED FLASH FLOODING TODAY AND TONIGHT ACROSS
MUCH OF THE AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
CONVECTIVELY ACTIVE DAY HAS STARTED TO RAMP UP SOMEWHAT THIS MORNING
AS FAVORABLE ATMOSPHERIC DYNAMICS COMBINE WITH A VERY MOIST
ENVIRONMENT. THE PRIMARY INVERTED TROUGH/VORTICITY CENTER WAS
PROPAGATING NORTH NEARING THE INTERNATIONAL BORDER SOUTHWEST OF
TUCSON...WHILE A LEADING CONVECTIVELY GENERATED VORTICITY MAX WAS
SUPPORTING DEVELOPING CONVECTION NEAR THE YUMA AREA. 12Z KPSR AND
KTWC SOUNDINGS DEPICTED DEEP SELY MOIST FLOW THROUGH THE LOWER AND
MIDDLE TROPOSPHERE CHARACTERIZED BY PWATS 1.75 INCHES AND LOW LEVEL
MIXING RATION 11-12 G/KG (NEAR 2 STANDARD DEVIATIONS ABOVE AVERAGE).
OBJECTIVE ANALYSIS SUGGESTS PWATS IN EXCESS OF 2 INCHES ADVECTING
NORTH TOWARDS THE CWA...WHILE DIFLUENCE ALOFT AND FORCED ASCENT
INCREASE ACROSS THE REGION.
AT 9AM...SFC TEMPERATURES HAVE RISEN INTO THE MID 80S TO MID 90S
(OUTSIDE OF THUNDERSTORMS THAT HAVE CONTINUED SINCE EARLIER IN THE
DAY) DESPITE THE THIN VEIL OF CIRRUS FROM EARLIER SONORAN COMPLEX.
BASED ON 12Z SOUNDING DATA AND FORECAST NAM-WRF BUFR
SOUNDINGS...ONCE TEMPERATURES REACH 98-100 DEGREES THE ENVIRONMENT
WILL BECOME CONVECTIVELY UNSTABLE (MLCAPES NEARING 1000 J/KG) WITH
LITTLE TO NO INHIBITION. WHILE LAPSE RATES ARE NOT PARTICULARLY
STEEP...TALL SKINNY CAPE PROFILES WITH THICK MOISTURE SUPPORT
LOCALLY HEAVY RAIN PRODUCING CELLS (AND POTENTIALLY A COUPLE
MOISTURE LOADED UPDRAFT/DOWNBURST CELLS). WILL CONTINUE FLASH FLOOD
WATCH BASED MOSTLY ON PRECIP RATE EXPECTATION OVER POPULATION
CENTERS AS CELL PROPAGATION MAY PRECLUDE A WIDESPREAD FLOOD THREAT
(UNLESS LOCAL TRAINING ECHOES SET UP). OTHERWISE...MADE MINOR
ADJUSTMENTS TO TEMPS AND POPS FOR THE REMAINDER OF THE MORNING BASED
ON CURRENT TRENDS.
&&
.PREVIOUS DISCUSSION...
/605 AM MST TUE AUG 12 2014/
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES
ARE A GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR.
HIGH TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX
AREA. BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A MUCH WETTER PATTERN FOR THE NEXT 24 HOURS OR SO...WITH SCATTERED
TO WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION...TOPS
GENERALLY 38-42KFT. EXPECT SCT-BKN CLOUD DECKS AOA 8000 FT...LOCAL
CIGS AS LOW AS 6000 FT AND VISIBILITY DOWN TO 4SM IN HEAVY RAIN WITH
STRONGER STORMS. ANTICIPATE STORM ACTIVITY TO PEAK DURING AFTERNOON
HOURS AND PERSIST THROUGH 05Z WEDNESDAY AS UPPER LEVEL DISTURBANCE
MOVES THROUGH THE AREA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND.
THE BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A 10-25
PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 AM MST TUE AUG 12 2014
.SYNOPSIS...ABUNDANT MOISTURE IN COMBINATION WITH AN UPPER LEVEL
DISTURBANCE WILL PROVIDE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS INTO TONIGHT. SOME STORMS WILL PRODUCE HEAVY RAIN AND
PERHAPS STRONG WINDS. EXPECT SCATTERED THUNDERSTORMS WEDNESDAY
THROUGH THURSDAY FOLLOWED BY A DOWNTURN IN ACTIVITY FRIDAY AND
SATURDAY.
&&
.DISCUSSION...SCATTERED TO NUMEROUS SHOWERS/TSTMS WERE ACROSS
WRN/CENTRAL PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY AT THIS TIME.
OTHER ISOLATED SHOWERS WERE ACROSS SRN GRAHAM/NRN COCHISE COUNTIES.
ABUNDANT MOISTURE ACROSS SE AZ THIS MORNING WITH DEWPOINTS VALID 16Z
MOSTLY IN THE 60S F. 12/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS
1.76 INCHES...AND THIS VALUE WAS ALMOST TWO STANDARD DEVIATIONS
ABOVE NORMAL.
1453Z BLENDED TOTAL PRECIP WATER IMAGERY INDICATED VALUES RANGING
FROM AROUND 0.75 INCHES ACROSS THE WHITE MOUNTAINS TO NEARLY 2.10
INCHES ACROSS FAR WRN PIMA COUNTY. 12/12Z UPPER AIR PLOTS DEPICTED
593 DM HIGH PRESSURE CENTERED NEAR THE FOUR CORNERS REGION WITH DEEP
TROUGHS OFF THE PACIFIC NW COAST AND OVER THE GREAT LAKES REGION.
LIGHT TO MODERATE SELY FLOW PREVAILED IN THE SURFACE-300 MB LAYER.
VISIBLE SATELLITE IMAGERY DEPICTED A CYCLONIC CIRCULATION SYSTEM
CENTERED JUST NORTH OF HERMOSILLO SONORA MOVING NWWD ACROSS NWRN
SONORA MEXICO. THE FAVORED AREA FOR SHOWERS/TSTMS TO OCCUR THIS
MORNING WILL BE AHEAD OF THIS SYSTEM WEST OF TUCSON. HAVE NOTED THAT
THE 12/14Z RUC HRRR THEN DECREASES COVERAGE OF SHOWERS/TSTMS WEST OF
TUCSON EARLY THIS AFTERNOON. HOWEVER...SCATTERED TO NUMEROUS
SHOWERS/TSTMS ARE THEN PROGGED TO OCCUR FROM THE TUCSON METRO AREA
EWD TO THE NEW MEXICO BORDER BY MID AFTERNOON AND CONTINUING INTO
THIS EVENING.
HOWEVER...THE 12/12Z UNIV OF AZ WRF-NAM WAS SOMEWHAT DIFFERENT
VERSUS THE RUC HRRR. FOR INSTANCE...THE 12/12Z UNIV OF AZ WRF-NAM
DEPICTED WIDESPREAD COVERAGE OF SHOWERS/TSTMS EARLY THIS
AFTERNOON...THEN FAVORED THE AREA FOR SHOWERS/TSTMS GENERALLY FROM
TUCSON WWD/NWWD LATE THIS AFTERNOON AND EARLY THIS EVENING.
AT ANY RATE...THE INHERITED OFFICIAL FORECAST DEPICTS SCATTERED TO
NUMEROUS SHOWERS/TSTMS THIS AFTERNOON/EVENING FOLLOWED BY SCATTERED
SHOWERS AND ISOLATED TSTMS LATE TONIGHT. A FLASH FLOOD WATCH WILL BE
IN EFFECT FROM NOON MST TODAY UNTIL 1 AM MST WED. THE MAIN IMPACT
WILL BE HEAVY RAIN WITH THE POTENTIAL FOR FLASH FLOODING TO OCCUR.
THE STRONGER TSTMS WILL ALSO BE CAPABLE OF PRODUCING STRONG GUSTY
WINDS. HIGH TEMPS TODAY WILL GENERALLY AVERAGE ABOUT 2-5 DEGS F
BELOW NORMAL.
THERE ARE NO UPDATES PLANNED AT THIS TIME. PLEASE REFER TO THE
ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 13/18Z.
SCATTERED TO NUMEROUS -TSRA/-SHRA MOSTLY WEST OF KTUS THIS MORNING...
THEN SCATTERED TO NUMEROUS TSRA/SHRA AREA-WIDE THIS AFTERNOON AND
THIS EVENING. MVFR VISIBILITIES AND WIND GUSTS TO NEAR 45 KTS WILL
OCCUR WITH THE STRONGER TSRA. SCATTERED -SHRA AND ISOLD -TSRA WILL
THEN PREVAIL LATE TONIGHT INTO WEDNESDAY MORNING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DAILY SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED THIS WEEK...WITH A PEAK IN ACTIVITY TODAY
AND TONIGHT. STRONG...GUSTY AND ERRATIC WINDS BETWEEN 35 AND 45 MPH
ARE POSSIBLE WITH STRONGER THUNDERSTORMS. OTHERWISE...WINDS WILL
SHOW NORMAL DIURNAL TRENDS AND LESS THAN 15 MPH.
&&
.PREV DISCUSSION...MAIN IMPULSE SHIFTS INTO NORTHERN ARIZONA LATE
TONIGHT INTO WEDNESDAY ALONG WITH STRONGEST THUNDERSTORM THREAT. WE
WILL PROBABLY BE A LITTLE WORKED OVER WEDNESDAY FOR LESS
COVERAGE...BUT ANY STORMS WE GET WILL BE PRETTY WET. STILL LOOKS
MORE AND MORE LIKE INCREASING POTENTIAL FOR A SECONDARY HIGH CENTER
RECONSOLIDATION REORIENTING THE RIDGE INTO A PARTIAL BLOCKING
POSITION FRIDAY AND SATURDAY. A COUPLE OF DOWN DAYS TO END THE WEEK.
WE SHOULD BOUNCE BACK TOWARD AN AVERAGE DAY BY SUNDAY OR MONDAY AS
THE RIDGE AMPLIFIES NORTH OF US.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM NOON MST TODAY UNTIL 1 AM MST WEDNESDAY
FOR AZZ501>515.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...HUMPHREYS
PREVIOUS DISCUSSION...MEYER
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
605 AM MST TUE AUG 12 2014
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
...POTENTIAL FOR FLASH FLOODING TODAY AND TONIGHT ACROSS MUCH OF THE
AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT
LIFTS NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES
ARE A GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR.
HIGH TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX
AREA. BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...AND
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
A MUCH WETTER PATTERN FOR THE NEXT 24 HOURS OR SO...WITH SCATTERED
TO WIDESPREAD SHOWERS AND THUNDERSTORMS ACROSS THE REGION...TOPS
GENERALLY 38-42KFT. EXPECT SCT-BKN CLOUD DECKS AOA 8000 FT...LOCAL
CIGS AS LOW AS 6000 FT AND VISIBILITY DOWN TO 4SM IN HEAVY RAIN WITH
STRONGER STORMS. ANTICIPATE STORM ACTIVITY TO PEAK DURING AFTERNOON
HOURS AND PERSIST THROUGH 05Z WEDNESDAY AS UPPER LEVEL DISTURBANCE
MOVES THROUGH THE AREA.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND.
THE BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A 10-25
PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD TO
EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....MEYERS
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
310 AM MST TUE AUG 12 2014
...POTENTIAL FOR FLASH FLOODING TODAY AND TONIGHT ACROSS MUCH OF THE
AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT LIFTS
NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES ARE A
GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR. HIGH
TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX AREA.
BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
THUNDERSTORMS HAVE MOSTLY ENDED OVER THE SOUTH CENTRAL DESERTS...AND
SINCE THE BOUNDARY LAYER HAS BECOME STABILIZED...THREAT FOR STORMS
WILL REMAIN LOW FOR THE REST OF THE EVENING. AS SUCH NO MENTION OF
THUNDER WILL MADE IN THE AREA TAFS TONIGHT. THERE STILL EXISTS THE
POSSIBILITY OF ENHANCED OUTFLOW WINDS MOVING THRU THE TERMINALS
THROUGH 10-11 PM OR SO AS THERE ARE STILL STORMS FIRING ON THE
FRINGES OF THE PHOENIX METRO AREA. AGAIN...CANNOT RULE OUT A STORM
AFFECTING THE DESERTS OVERNIGHT BUT CHANCES WILL BE MOSTLY 20
PERCENT OR LESS...AND CONFIDENCE WAY TOO LOW TO MENTION IN THE TAFS.
FOR THE REST OF TONIGHT EXPECT CONSIDERABLE MID/UPPER LEVEL CLOUD
DECKS...MUCH OF IT DEBRIS CLOUD FROM NEARBY CONVECTION. MOST BASES
WILL BE AOA 10K FEET. WINDS TO FAVOR AN EASTERLY COMPONENT WITH
OCCASIONAL GUSTS TO 20KT OR SO...MAYBE A BIT HIGHER.
AS MOISTURE INCREASES TONIGHT INTO THE DAY TUESDAY...AND AN UPPER
DISTURBANCE APPROACHES FROM THE SOUTH...EXPECT A WETTER...CLOUDIER
AND MORE UNSETTLED PERIOD WITH A GOOD CHANCE FOR SHOWERS OR EMBEDDED
THUNDERSTORMS. MAY SEE CIGS LOWER TO 6K FEET OR BELOW DURING THE
DAY...ESPECIALLY SHOULD A STRONGER STORM OR HEAVY SHOWER MOVE ACROSS
ONE OF THE TERMINALS. OF COURSE...GUSTY VARIABLE WINDS AND
RESTRICTED VIS DUE TO BLOWING DUST OR HEAVY RAIN IS A POSSIBILITY
TUESDAY. FOR NOW WILL SIMPLY MENTION VCSH IN THE TERMINALS STARTING
AT ABOUT 18Z BUT A THUNDERSTORM COULD CERTAINLY OCCUR.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
INCREASING CLOUDS AND CHANCES FOR TSRA/SHRA OVERNIGHT TONIGHT INTO
THE DAY TUESDAY AS MOISTURE INCREASES FROM THE SOUTHEAST. DUE TO
LOWER CONFIDENCE WILL NOT MENTION THUNDER IN THE TAFS TONIGHT...AND
WILL OPT TO GO WITH VCSH STARTING MID MORNING TUESDAY. SHOULD STORMS
DEVELOP...TAFS WILL NEED TO BE UPDATED FOR APPROPRIATE SKY/VIS AND
WIND CONDITIONS. WINDS SHOULD FAVOR THE SOUTH OR SOUTHEAST AT KIPL
AND KBLH NEXT 18-24 HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND. THE
BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A
10-25 PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD
TO EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....CB
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
310 AM MST MON AUG 11 2014
...POTENTIAL FOR FLASH FLOODING TODAY AND TONIGHT ACROSS MUCH OF THE
AREA...
.SYNOPSIS...
MOISTURE LEVELS WILL CONTINUE TO INCREASE TODAY AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. SHOWERS AND THUNDERSTORMS ARE
EXPECTED TODAY AND TONIGHT ACROSS MUCH OF THE AREA. SOME STORMS WILL
BE CAPABLE OF PRODUCING VERY HEAVY RAIN AND AREAS OF FLOODING. WITH
THE MOIST CONDITIONS...TEMPERATURES WILL REMAIN BELOW NORMAL THE
NEXT FEW DAYS. A DRYING AND WARMING TREND IS EXPECTED LATE IN THE
WEEK AS HIGH PRESSURE BECOMES REESTABLISHED TO THE SOUTH.
&&
.DISCUSSION...
LATEST RAP STREAMLINE ANALYSIS SHOWS THE MID-TROPOSPHERIC HIGH
POSITIONED NEAR THE FOUR CORNERS. FURTHER SOUTH...A WELL-DEFINED
INVERTED TROUGH IS APPARENT ACROSS SONORA WHILE THUNDERSTORMS
ASSOCIATED WITH AN MCS PERSIST EARLY THIS MORNING. BETWEEN THE TWO
SYSTEMS...THE STEERING FLOW IS GENERALLY SOUTHEASTERLY AROUND 15 KT.
ACROSS THE FORECAST AREA...SCATTERED SHOWERS HAVE REDEVELOPED ACROSS
THE LOWER DESERTS...INCLUDING PORTIONS OF THE PHOENIX METRO AREA.
ALTHOUGH CAPE IS GENERALLY LACKING AT THIS HOUR...WEAK VORTICITY AND
JET-FORCED ASCENT ALONG WITH REMNANT OUTFLOW BOUNDARIES ARE
CONTRIBUTING TO THE NOCTURNAL CONVECTION.
CLASSIC SETUP FOR ACTIVE WEATHER IS IN PLACE AND ALL SIGNS POINT TO
FAVORABLE CONDITIONS FOR ADDITIONAL STORM DEVELOPMENT AS EARLY AS
THIS MORNING ACROSS THE REGION. LATEST GPS-IPW AT TEMPE REGISTERED
AS HIGH AS 1.85 INCHES. MODELS INDICATE THAT THE ATMOSPHERE WILL
CONTINUE TO SATURATE AND ALONG WITH INCREASING DEEP LAYER
FLOW...STRONGER INSTABILITY AND SYNOPTIC ASCENT AHEAD OF THE
APPROACHING VORT MAX...SHOWERS AND THUNDERSTORMS WILL LIKELY BECOME
WIDESPREAD DURING THE AFTERNOON AND EVENING. GIVEN THE ANOMALOUSLY
(150-200% OF NORMAL) MOIST PROFILE...FLASH FLOODING WILL BE THE
PRIMARY THREAT AND A FLASH FLOOD WATCH HAS BEEN ISSUED FOR A LARGE
PORTION OF THE AREA. POPS WERE ALSO INCREASED TO AROUND 70 PERCENT
FOR THE PHOENIX AREA AND AS HIGH AS 80 PERCENT ACROSS THE HIGHER
TERRAIN OF SOUTHERN GILA COUNTY. GLOBAL AND CONVECTIVE ALLOWING
MODELS ARE STILL SOMEWHAT UNCERTAIN WITH REGARD TO THE EXACT SPEED
OF THE TROUGH AS IT LIFTS NORTHWARD THROUGH THE FORECAST AREA.
CONSEQUENTLY...THE POTENTIAL FOR HEAVY RAIN WILL OCCUR OVER A
RELATIVELY LONG TIME WINDOW...PERHAPS EVEN CONTINUING INTO WEDNESDAY
MORNING MAINLY FROM PHOENIX NORTHWARD. SOME LOCATIONS MAY SEE STORM
TOTALS IN EXCESS OF 1.0-1.5 INCHES.
AFOREMENTIONED VORT MAX WILL ACCELERATE SOMEWHAT WEDNESDAY AS IT LIFTS
NORTHEASTWARD INTO NORTHERN ARIZONA. BELOW NORMAL TEMPERATURES ARE A
GOOD BET GIVEN THE DEEP MOISTURE AND RESIDUAL RAIN-COOLED AIR. HIGH
TEMPERATURES WERE LOWERED INTO THE MID 90S FOR THE PHOENIX AREA.
BEST CHANCE FOR PRECIPITATION APPEARS TO BE ACROSS THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX. HOWEVER...A MOIST SOUTHWESTERLY
FLOW SUGGESTS THE POSSIBILITY OF BACK-BUILDING CELLS INTO THE LOWER
DESERTS AND POPS WERE INCREASED TO 50 PERCENT IN THESE AREAS.
A DRIER SOUTHWESTERLY FLOW WILL DEVELOP IN THE WAKE OF THE LOW
PRESSURE SYSTEM BY THURSDAY...WHICH WILL CONFINE THUNDERSTORMS
MAINLY TO THE HIGHER TERRAIN OF NORTHERN AND EASTERN AZ. A WARMING
AND DRYING TREND IS ALSO EXPECTED LATE IN THE WEEK AND INTO EARLY
NEXT WEEK AS THE MONSOON HIGH DRIFTS SOUTHWARD...GIVING WAY TO MORE
OF A WESTERLY FLOW.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
THUNDERSTORMS HAVE MOSTLY ENDED OVER THE SOUTH CENTRAL DESERTS...AND
SINCE THE BOUNDARY LAYER HAS BECOME STABILIZED...THREAT FOR STORMS
WILL REMAIN LOW FOR THE REST OF THE EVENING. AS SUCH NO MENTION OF
THUNDER WILL MADE IN THE AREA TAFS TONIGHT. THERE STILL EXISTS THE
POSSIBILITY OF ENHANCED OUTFLOW WINDS MOVING THRU THE TERMINALS
THROUGH 10-11 PM OR SO AS THERE ARE STILL STORMS FIRING ON THE
FRINGES OF THE PHOENIX METRO AREA. AGAIN...CANNOT RULE OUT A STORM
AFFECTING THE DESERTS OVERNIGHT BUT CHANCES WILL BE MOSTLY 20
PERCENT OR LESS...AND CONFIDENCE WAY TOO LOW TO MENTION IN THE TAFS.
FOR THE REST OF TONIGHT EXPECT CONSIDERABLE MID/UPPER LEVEL CLOUD
DECKS...MUCH OF IT DEBRIS CLOUD FROM NEARBY CONVECTION. MOST BASES
WILL BE AOA 10K FEET. WINDS TO FAVOR AN EASTERLY COMPONENT WITH
OCCASIONAL GUSTS TO 20KT OR SO...MAYBE A BIT HIGHER.
AS MOISTURE INCREASES TONIGHT INTO THE DAY TUESDAY...AND AN UPPER
DISTURBANCE APPROACHES FROM THE SOUTH...EXPECT A WETTER...CLOUDIER
AND MORE UNSETTLED PERIOD WITH A GOOD CHANCE FOR SHOWERS OR EMBEDDED
THUNDERSTORMS. MAY SEE CIGS LOWER TO 6K FEET OR BELOW DURING THE
DAY...ESPECIALLY SHOULD A STRONGER STORM OR HEAVY SHOWER MOVE ACROSS
ONE OF THE TERMINALS. OF COURSE...GUSTY VARIABLE WINDS AND
RESTRICTED VIS DUE TO BLOWING DUST OR HEAVY RAIN IS A POSSIBILITY
TUESDAY. FOR NOW WILL SIMPLY MENTION VCSH IN THE TERMINALS STARTING
AT ABOUT 18Z BUT A THUNDERSTORM COULD CERTAINLY OCCUR.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
INCREASING CLOUDS AND CHANCES FOR TSRA/SHRA OVERNIGHT TONIGHT INTO
THE DAY TUESDAY AS MOISTURE INCREASES FROM THE SOUTHEAST. DUE TO
LOWER CONFIDENCE WILL NOT MENTION THUNDER IN THE TAFS TONIGHT...AND
WILL OPT TO GO WITH VCSH STARTING MID MORNING TUESDAY. SHOULD STORMS
DEVELOP...TAFS WILL NEED TO BE UPDATED FOR APPROPRIATE SKY/VIS AND
WIND CONDITIONS. WINDS SHOULD FAVOR THE SOUTH OR SOUTHEAST AT KIPL
AND KBLH NEXT 18-24 HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR WILL FILTER INTO THE DISTRICT BEGINNING THURSDAY...WITH
MORE PREVALENT CLEAR SKIES AND LOWER HUMIDITIES OVER THE WEEKEND. THE
BEST CHANCES FOR RAINFALL THURSDAY AND FRIDAY WILL BE OVER GILA
COUNTY AS SOME RESIDUAL MOISTURE LINGERS OVER HIGHER TERRAIN. WITH
NEAR AVERAGE TEMPERATURES...AFTERNOON RELATIVE HUMIDITY VALUES
FALLING INTO A 25-40 PERCENT RANGE THURSDAY WILL DRY TOWARDS A
10-25 PERCENT RANGE BY THE WEEKEND. OVERNIGHT RECOVERY WILL BE GOOD
TO EXCELLENT. OUTSIDE OF ANY GUSTY THUNDERSTORM WINDS
THURSDAY...TYPICAL LIGHT SUMMER WINDS WILL PREVAIL.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FLASH FLOOD WATCH FROM NOON MST TODAY THROUGH WEDNESDAY MORNING
AZZ020>028.
CA...FLASH FLOOD WATCH FROM NOON PDT TODAY THROUGH WEDNESDAY MORNING
CAZ031>033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....CB
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS TUCSON AZ
250 AM MST TUE AUG 12 2014
.SYNOPSIS...A STRONG INCREASE IN SHOWERS AND THUNDERSTORMS IS
EXPECTED TODAY AND TONIGHT AS MOISTURE DEEPENS AND A PASSING
DISTURBANCE HELPS TO ORGANIZE STORMS. SOME STORMS ARE EXPECTED TO
GENERATE HEAVY RAIN AND STRONG WINDS. THERE WILL BE ENOUGH MOISTURE
TO KEEP A CHANCE OF THUNDERSTORMS IN THE FORECAST THROUGH THURSDAY
BEFORE A DOWNTURN IN ACTIVITY IS EXPECTED FRIDAY AND SATURDAY.
&&
.DISCUSSION...COMPLEX FROM NORTHWEST SONORA NOW PUSHING THROUGH FAR
WESTERN PIMA AND INTO EASTERN YUMA COUNTY. ANOTHER COMPLEX SOUTH OF
NOGALES STILL HAS AN ACTIVE SOUTHERN FLANK WITH DEBRIS AND WEAK
OUTFLOW PUSHING NORTH ON THE NORTHERN FLANK.
CONSIDERABLE MOISTURE WITH PRECIPITABLE WATER VALUES FROM 1.6 INCHES
NEAR THE NEW MEXICO BORDER TO 1.8 INCHES NEAR WESTERN PIMA
COUNTY...PROBABLY EVEN A LITTLE HIGHER BY THIS AFTERNOON. A DECENT
IMPULSE EMBEDDED IN SOUTHEASTERLY FLOW WILL ENHANCE THUNDERSTORM
COVERAGE AND ORGANIZATION AS WELL AS POTENTIAL RAINFALL EFFICIENCY
THIS AFTERNOON AND TONIGHT. ELEVATED HEAVY RAIN THREAT COMBINED WITH
RECENT LOCALLY HEAVY RAINFALL IN SEVERAL AREAS FOR A FLASH FLOOD
WATCH FROM NOON TODAY THROUGH 1AM TONIGHT. GENERAL SHORT AND MEDIUM
RANGE MODEL AGREEMENT WITH LATEST HRRR DEVELOPING TRENDS THAT
DEVELOP MORE WIDESPREAD SHOWER AND THUNDERSTORM COVERAGE ALONG WITH
WELL ABOVE AVERAGE QPF VALUES. HOPEFULLY NOT A CASE WHERE WE HAVE
MORE MOISTURE THAN WE CAN USE...BUT THE AFOREMENTIONED IMPULSE
SHOULD HELP WITH THAT.
MAIN IMPULSE SHIFTS INTO NORTHERN ARIZONA LATE TONIGHT INTO
WEDNESDAY ALONG WITH STRONGEST THUNDERSTORM THREAT. WE WILL PROBABLY
BE A LITTLE WORKED OVER WEDNESDAY FOR LESS COVERAGE...BUT ANY STORMS
WE GET WILL BE PRETTY WET.
STILL LOOKS MORE AND MORE LIKE INCREASING POTENTIAL FOR A SECONDARY
HIGH CENTER RECONSOLIDATION REORIENTING THE RIDGE INTO A PARTIAL
BLOCKING POSITION FRIDAY AND SATURDAY. A COUPLE OF DOWN DAYS TO END
THE WEEK. WE SHOULD BOUNCE BACK TOWARD AN AVERAGE DAY BY SUNDAY OR
MONDAY AS THE RIDGE AMPLIFIES NORTH OF US.
&&
.AVIATION...VALID THRU 13/09Z.
ISOLD -SHRA/TS THIS MORNING. INCREASING SHOWERS AND THUNDERSTORMS
THIS AFTERNOON...BECOMING WIDESPREAD AND LIKELY AT ALL TAF LOCATIONS
BY 12/21Z. LCL MVFR VSBY CONDS AND STRONG GUSTY WINDS TO 45 KTS NEAR
TSTMS. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DAILY SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS ARE EXPECTED THIS WEEK...WITH A PEAK IN ACTIVITY TODAY
AND TONIGHT. STRONG...GUSTY AND ERRATIC WINDS BETWEEN 35 AND 45 MPH
ARE POSSIBLE WITH STRONGER THUNDERSTORMS. OTHERWISE...WINDS WILL
SHOW NORMAL DIURNAL TRENDS AND LESS THAN 15 MPH.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH FOR ALL OF
SOUTHEAST ARIZONA INCLUDING AZZ501>515 FROM NOON TODAY
UNTIL 1 AM MST WEDNESDAY.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
MEYER/RASMUSSEN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
330 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 330 PM MDT TUE AUG 12 2014
FOR TONIGHT...OVERALL THE AIRMASS WILL REMAIN DRY AND SUBSIDENT
WITH THE UPPER LEVEL RIDGE OVERHEAD. THERE WILL BE ENOUGH MOISTURE
IN THE MOUNTAINS FOR A FEW EVENING THUNDERSTORMS...BUT COVERAGE
WILL BE LIMITED AND THE DURATION SHORT LIVED. THE HRRR SHOWS VERY
LIMITED DEVELOPMENT IN AND AROUND SUMMIT AND PARK COUNTIES BUT
DRY ELSEWHERE. ON WEDNESDAY...THE RIDGE IS PROGGED TO SHIFT TO THE
EAST WITH THE FLOW ALOFT BECOMING SOUTHWESTERLY. SUBTROPICAL
MOISTURE WILL INCREASE OVER WESTERN COLORADO AHEAD OF AN
APPROACHING UPPER LEVEL DISTURBANCE FM THE DESERT SOUTHWEST. THE
COVERAGE OF TSTMS WILL INCREASE IN THE MOUNTAINS AND PRECIPITABLE
WATER VALUES ARE PROGGED TO INCREASE AS WELL. BY LATE AFTN...SOME
OF TSTMS WILL START TO SPREAD INTO THE URBAN CORRIDOR. STORM
MOTIONS IN THE HIGH COUNTRY WEDNESDAY AFTN WILL BE SSW AROUND 15
KTS. ACROSS THE URBAN CORRIDOR AND ADJACENT PLAINS...SELY WINDS
WILL INCREASE IN THE AFTN...STG ENOUGH TO INDUCE A WEAK DENVER
CYCLONE. AS A RESULT...WL GO WITH A SLGT CHC OF TSTMS IN THE
AFTERNOON. CAPES AT KDEN IN THE 350-450MB RANGE BY 00Z THURSDAY
WITH PW VALUES CLOSE TO ONE INCH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 PM MDT TUE AUG 12 2014
THE NEXT WEEK WILL SEE CONTINUED RIDGING OVER THE SOUTHWESTERN
U.S. BUT WITH A SIGNIFICANT SURGE OF MONSOONAL MOISTURE ACROSS
COLORADO FOR THE LATTER HALF OF THIS WEEK. MOUNTAIN AREAS ARE
GOING TO SEE MOST OF THE PRECIPITATION FROM THE MONSOONAL
MOISTURE...BUT THE PLAINS WILL NOT BE IMMUNE TO THE RAINFALL. THE
WESTERN SLOPE SHOULD SEE THE ARRIVAL OF THE DEEPER MOISTURE BY
WEDNESDAY AFTERNOON...BUT COMPUTER MODELS ARE SHOWING A SHORT WAVE
TROUGH MOVING THROUGH THE UPPER RIDGE ON THURSDAY WHICH IS GOING
TO ORGANIZE AND SUSTAIN MOUNTAINS CONVECTION THROUGH THE DAY AND
ONTO THE PLAINS THURSDAY EVENING. ANOTHER ROUND OF AFTERNOON
SHOWERS IS EXPECTED ON FRIDAY AS ABUNDANT MONSOONAL MOISTURE
REMAINS OVER THE STATE AND UPPER LEVEL HEIGHTS BEGIN RISING. THE
REST OF THE WEEKEND WILL CONTINUE WITH MODERATE RIDGING ALOFT AND
A CONTINUED INTRUSION OF MONSOONAL MOISTURE UNDER THE RIDGE. FLOW
ALOFT WILL BE LIGHT TO MODERATE AND OUT OF THE WEST...MAKING IT
POSSIBLE FOR STORMS TO BE SLOW-MOVING AND CAPABLE OF PRODUCING
LOCALLY HEAVY RAINS. NO CHANGE IN THE UPPER LEVEL FLOW PATTERN
EXPECTED BEFORE THE MIDDLE OF NEXT WEEK. IN FACT...THE ECMWF IS
SHOWING ANOTHER MONSOONAL SURGE ARRIVING NEXT TUESDAY. UNTIL THEN
TEMPERATURES WILL BE AROUND SEASONAL NORMALS WITH A CHANCE OF
AFTERNOON SHOWERS EACH DAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 330 PM MDT TUE AUG 12 2014
NO CIG/VSBY RESTRICTIONS ANTICIPATED THROUGH 00Z THURSDAY. AMS TOO
DRY AND SUBSIDENT IN THE MID LEVELS FOR TSTMS THIS AFTN AND
EVENING. DIURNAL WIND PATTERN WITH TYPICAL DRAINAGE WINDS THROUGH
18Z WEDNESDAY. AFT 18Z WEDNESDAY...SELY WINDS WILL INCREASE IN
THE AFTN SO SHOULD BE SUFFICIENT ENOUGH TO PRODUCE A WEAK DENVER
CYCLONE. ENOUGH MOISTURE AND INSTABILITY IN THE AFTN TO MENTION
VCTSIN WEDNESDAY AFTN...PROBABLY AFTER 21-22Z. COULD SEE BKN
CIGS AOA 080FT AGL BY LATE THU AFTN/EVNG...AS MID LEVEL MOISTURE
INCREASES FM THE SOUTHWEST.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM...DANKERS
AVIATION...COOPER
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
958 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE OVER LAKE HURON EDGES NORTH TO NEAR JAMES BAY CANADA AS
NEW LOW PRESSURE FORMS ALONG THE COLD FRONT PUSHING THROUGH NEW
JERSEY EARLY WEDNESDAY. THEREAFTER...LOW PRESSURE IN QUEBEC
DOMINATES THROUGH THURSDAY WITH MIDWEST HIGH PRESSURE EVENTUALLY
MOVING TO THE MID ATLANTIC COAST FRIDAY. ANOTHER COLD FRONTAL
PASSAGE IS POSSIBLE LATE SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SURFACE WARM FRONT IS STILL DRAPED ACROSS CENTRAL NORTH
CAROLINA WITH THE OCCLUSION SLOWLY MOVING INTO WESTERN
PENNSYLVANIA. THE WARM FRONT HAS BEEN SLOW TO MOVE NORTHWARD AS
THE INITIAL SHOT OF RAIN THIS MORNING AND THE SOUTHEAST FLOW AHEAD
OF THE FRONT HAS INCREASED EARLY PREVENTING A QUICKER MOVEMENT.
THE WARM FRONT TIMING PLAYS A HUGE FACTOR IN HOW QUICKLY THE
STRONGER OVER-RUNNING AND POSSIBLE CONVECTIVE ACTIVITY RE-ENTERS
THE REGION.
OF THE HI-RES MODELS, THE HRRR SEEMS TO HAVE THE BEST HANDLE ON
THE PRECIPITATION SHIELD THIS MORNING. IT SHOWS A DECENT AMOUNT OF
DRYING ACROSS THE CENTRAL AND SOUTHERN PORTIONS OF THE CWA BEFORE
FILLING BACK IN FROM THE SOUTH-SOUTHWEST...WARM FRONT/THETA-E
UPGLIDE INDUCED. THAT BEING SAID, DID SCALE BACK POPS FOR THE NEXT
FEW HOURS ACROSS A THE SOUTHEASTERN HALF OF THE CWA BEFORE RAMPING
THEM UP AGAIN LATER THIS AFTERNOON.
OTHERWISE, THE STRETCH OF NICE WEATHER HAS COME TO AN END TODAY
AS OUR REGION BECOMES MORE AND MORE UNDER THE INFLUENCE OF AN
AMPLIFYING UPPER-LEVEL TROUGH TO THE WEST THAT CLOSES OFF. THIS
FEATURE WILL DRIVE DOWNSTREAM WAA AND THETA-E ADVECTION THROUGH
THE DAY, WHICH WILL BE AIDED BY AN UPTICK IN THE WIND FIELD. THE
FORECAST CHALLENGE REVOLVES AROUND THE TIMING OF THE SHOWERS WITH
AN EASTWARD EXTENT AS THE MID LEVEL RIDGE DEPARTS TO THE EAST, AND
ALSO THE EXTENT OF WINDS AND TEMPERATURES. IT DOES APPEAR HOWEVER
THE STRONGER LIFT ENHANCED BY AN INCREASING LOW-LEVEL JET ARRIVES
LATER IN THE DAY AND THEN TONIGHT.
THE SYNOPTIC SETUP WILL RESULT IN A SOUTHEASTERLY LOW-LEVEL FLOW
DOMINATING OUR REGION TODAY, HOWEVER THIS DOES VEER TO THE SOUTH AND
SOUTHWEST WITH HEIGHT. THIS WILL HELP TO ENHANCE THE WAA, WITH A
WARM FRONT TO OUR SOUTH TRYING TO LIFT INTO THE DELMARVA. THIS WARM
FRONT PROBABLY DOES NOT GET ANY FARTHER THAN PORTIONS OF THE
DELMARVA. THIS WILL MAINTAIN THE FLOW OFF THE OCEAN AND ALSO RESULT
IN DEEPER MOISTURE TRANSPORT AS THE ISENTROPIC LIFT INCREASES SOME
THROUGH THE DAY. THIS WILL RESULT IN SOME SHOWERS MOVING THROUGH
THIS MORNING ESPECIALLY THE WESTERN ZONES, THEN PERHAPS A
BREAK FOR PORTIONS OF THE AREA BEFORE STRONGER LIFT STARTS TO ARRIVE
BY LATE IN THE AFTERNOON. THE FORECAST SOUNDINGS OVERALL SHOW A
MOISTENING ENVIRONMENT WHICH WILL TEND TO HOLD DOWN THE INSTABILITY.
THE ONSHORE FLOW WILL ALSO TEND TO LIMIT THE SURFACE BASED
INSTABILITY OVERALL. THEREFORE, ANY THUNDER SHOULD GENERALLY BE
LIMITED AND PROBABLY NOT OCCUR UNTIL LATER THIS AFTERNOON WHEN THE
SOUNDINGS SHOW MUCH DEEPER MOISTURE WITHIN A HIGHER SHEAR/LOW CAPE
SETUP DEVELOPING. THERE WILL ALSO BE AN UPSLOPE COMPONENT, WHICH CAN
ENHANCE THE RAINFALL TOWARD OUR WEST/NORTHWEST ZONES.
A SPOT TO WATCH THOUGH IS CLOSE TO THE WARM FRONT AS SHEAR WILL BE
ENHANCED HERE WITH THE POTENTIAL FOR SOME INCOMING CONVECTION TO
OVERRUN THIS BOUNDARY. IT DOES APPEAR THAT THE VERTICAL SHEAR COULD
BE SUFFICIENT ENOUGH TO COMPENSATE FOR THE LOWER INSTABILITY AND
ALLOW FOR STORM ORGANIZATION. HOWEVER, THE CONVECTION MAY TEND TO BE
LOW-TOPPED AND LOCALLY GUSTY CONVECTIVE WINDS CANNOT BE RULED OUT
LATER THIS AFTERNOON ESPECIALLY SOUTH. WE WILL HAVE TO SEE IF A DRY
SLOT IS ABLE TO ALLOW FOR MORE BREAKS OF SUNSHINE. ANY STRONGER
CONVECTIVE CELLS SHOULD TEND TO BE IN THE FORM OF LINE SEGMENTS,
ALTHOUGH A LOW-TOPPED CELL WITH SUPERCELL STRUCTURE /BRIEF SPIN-UP/
IS POSSIBLE MAINLY NEAR THE WARM FRONT.
AS FOR HIGH TEMPERATURES, WE USED A NAM/GFS MOS BLEND WITH SOME
DOWNWARD ADJUSTMENTS BASED ON THE IDEA OF CLOUD COVER AND ALSO THE
ONSHORE FLOW KEEPING THE SURFACE TEMPERATURES A BIT COOLER. THE
PRESSURE GRADIENT IS FORECAST TO TIGHTEN SOME THROUGH THE DAY,
RESULTING IN SOME INCREASE OF THE LOW-LEVEL WIND FIELD. WHILE DEEP
MIXING SHOULD NOT OCCUR, THE GRADIENT WIND WITHIN A SOUTHEASTERLY
LOW-LEVEL FETCH SHOULD RESULT IN SOME GUSTINESS AT TIMES MAINLY
THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
A STRONG UPPER-LEVEL TROUGH WILL CONTINUE TO SWING ACROSS THE GREAT
LAKES AND OHIO VALLEY TONIGHT. THIS FEATURE LOOKS TO TAKE ON A
NEGATIVE TILT AS IT APPROACHES THE MID ATLANTIC REGION OVERNIGHT.
OVERALL THOUGH, THE LARGE SCALE LIFT WILL BE STRONGEST TONIGHT AS IT
WORKS IN TANDEM WITH A HIGH PW ENVIRONMENT. THE WARM FRONT MAY NOT
MAKE MUCH NORTHWARD PROGRESS AS THE INCOMING COLD FRONT PROBABLY
OCCLUDES, HOWEVER SOME INCREASE IN THE INSTABILITY MAY OCCUR FOR AT
LEAST LOW-TOPPED CONVECTION WHICH COULD BE STRONG ENOUGH TO RESULT
IN LOCALLY STRONG WIND GUSTS. THE SETUP LOOKS NEARLY LIKE A
LOW-TOPPED CONVECTIVE LINE OR LINE SEGMENTS DEVELOPING AND SHIFTING
EASTWARD ACROSS MUCH OF THE AREA DURING THE NIGHT. THIS MAY DELIVER
THE MORE INTENSE DOWNPOURS AS IT IS DRIVEN BY A STRONGER LOW-LEVEL
JET WITHIN AN AIRMASS CHARACTERIZED BY PW VALUES BETWEEN 2.0 AND 2.4
INCHES. THERE COULD BE SOME ENHANCEMENT TO THE RAINFALL AND
LOW-LEVEL SHEAR WITH A SURFACE LOW DEVELOPING NEAR THE TRIPLE POINT
GENERALLY ACROSS OUR SOUTHERN ZONES.
THE DOWNPOURS THROUGH TONIGHT MAY RESULT IN SOME TIMES OF POOR
DRAINAGE AND/OR PONDING OF WATER ON SOME ROADWAYS, HOWEVER THE FLASH
FLOOD AND HEADWATER GUIDANCE IS RATHER HIGH ACROSS NEARLY THE ENTIRE
AREA. THE MAIN CONCERN IS HIGH RAINFALL RATES ESPECIALLY WITHIN THE
URBAN CORRIDOR AND TERRAIN LOCATIONS. OVERALL THOUGH ANY FLOOD
THREAT SHOULD BE LOCALIZED AND THEREFORE WE WILL HOLD OFF ON ANY
FLASH FLOOD WATCHES ATTM. THIS WILL BE RE-EXAMINED DURING THE DAY
TODAY. WE MAINTAINED CATEGORICAL POPS ACROSS MUCH OF THE AREA, WITH
SOME DECREASE INDICATED FROM SOUTHWEST TO NORTHEAST TOWARD DAYBREAK.
AS FOR TEMPERATURES, WE MAINLY USED AN EVEN NAM/GFS MOS BLEND.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
500MB: THE GENERAL TROUGH OVER THE EASTERN UNITED STATES TO START
THE PERIOD MAY LINGER NEXT WEEKEND AFTER WHICH A RIDGE MAY BUILD
OVER THE EASTERN USA EARLY NEXT WEEK.
TEMPERATURES: NEAR NORMAL DURING THE DAY WEDNESDAY THEN CALENDAR DAY
AVERAGES THURSDAY-SATURDAY 3 TO 6 DEGREES BELOW NORMAL EACH DAY
MAY WARM SEVERAL DEGREES ABOVE NORMAL EARLY NEXT WEEK?
FORECAST BASIS: UNLESS OTHERWISE NOTED THE LONG TERM PERIOD OF THIS
FORECAST IS GENERALLY BASED ON A 50 50 BLEND OF THE 00Z/12 NAM/GFS
MOS FOR THE PERIOD WEDNESDAY - THURSDAY... THE 00Z/12 GFS MOS
THURSDAY NIGHT AND FRIDAY AND THEN THEREAFTER (FRIDAY NIGHT ONWARD) THE
0543Z/12 WPC GRIDDED GUIDANCE. THIS WAS CHECKED AGAINST THE 00Z/12
ECMWF TO SEE IF WE`RE IN THE BALLPARK WITH ECMWF 18Z 2METER
TEMPERATURES. THE PRECIPITATION PROBABILITY GUIDANCE IS CHECKED
AGAINST THE 21Z/11 SREF POPS FOR .01 IN 3 HRS THROUGH 12Z FRIDAY
AND THEREAFTER THE 00Z/12 GEFS 6HR POPS FOR 0.05.
WEDNESDAY...LEFTOVERS DEPART NORTHEASTWARD WITH A CHANCE OF A NARROW
LINE OF LOW TOP CONVECTION DEVELOPING IN THE LEFTOVER HIGH PWAT
AIR ACROSS NJ/DE MIDDAY...THEN DRYING OUT DURING THE AFTN AS WEST
WINDS GUST 20 MPH. BLENDED 00Z/12 GFS/NAM GUIDANCE. COOLER AT NIGHT.
THURSDAY...THERE IS A SMALL CHC OF A SHOWER OR SPRINKLE IN THE
HILLS OF NW NJ AND AND E PA MIDDAY BEFORE DRYING DISSIPATES ANY
BRIEF AND ESSENTIALLY INCONSEQUENTIAL SHOWERS. OTHERWISE NICE.
WEST WIND GUSTS 15 T0 20 MPH.
FRIDAY/SATURDAY...CLEAR TO PC...MOST OF THE CLOUDS DIURNALLY
DRIVEN. LIGHT WIND AND COOL NIGHTS AS THE GENERALLY COOLER THAN
NORMAL START TO AUGUST CONTINUES.
SUNDAY...WARM AIR ADVECTION CLOUDS AND MAYBE A PERIOD OF SHOWERS
AND THUNDERSTORMS AHEAD OF ANOTHER POSSIBLE COLD FRONT. CONFIDENCE
FOR THIS POSSIBLE NEXT COLD FRONT IS BELOW AVERAGE SINCE THE 00Z/12
GEFS TEMPERATURE CONFIDENCE IMAGERY FOR WARMER THAN OUR PHI FCST
TEMPS IS A BIT ABOVE AVERAGE. IN OTHER WORDS...MODEL SOLUTIONS ARE
NOT IN AGREEMENT FOR SUNDAY. THE ECMWF SECONDARY SHORT WAVE
PASSAGE THIS WEEKEND MAY BE TOO ROBUST. A WEAKER ECMWF SOLUTION
PERMITS A DRY NICE SUMMER WEEKEND.
MONDAY...P.C. AND MAYBE BEGINNING A WARMER MORE SUMMERY WEEK?
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...VFR CEILINGS LOWERING TO MVFR. THERE COULD BE TIMES THOUGH
LATE THIS MORNING AND EARLY THIS AFTERNOON WHERE ANY MVFR CEILINGS
RISE BACK TO VFR. SHOWERS WILL OVERSPREAD THE AREA THROUGH THE DAY,
WITH THE HEAVIER INTENSITY PROBABLY NOT OCCURRING UNTIL THIS
AFTERNOON. THIS WILL RESULT IN MVFR/IFR VISIBILITIES AT TIMES. ANY
IFR CEILINGS LATER IN THE DAY SHOULD BE LOCAL/BRIEF. SOUTHEASTERLY
WINDS INCREASING TO 10-15 KNOTS, WITH SOME GUSTS TO AROUND 20 KNOTS
MAINLY THIS AFTERNOON. THE GUSTINESS MAY BE MORE NOTED AT KILG AND
KACY.
TONIGHT...MVFR /POSSIBLE IFR CEILINGS FOR A TIME/ WITH SHOWERS AND
SOME THUNDERSTORMS. THERE WILL BE MODERATE TO HEAVY RAIN AT TIMES,
RESULTING IN GREATLY REDUCED VISIBILITIES. SOME THUNDERSTORMS COULD
BE IN THE FORM OF A LINE, WITH THE POTENTIAL FOR GUSTY WINDS.
SOUTHEASTERLY WINDS GENERALLY AROUND 10 KNOTS, HOWEVER THERE COULD
BE SOME LOCAL GUSTINESS ESPECIALLY CLOSER TO THE COAST IF ENOUGH
MIXING CAN BE MAINTAINED.
OUTLOOK...
WEDNESDAY...ANY LEFTOVER MVFR OR IFR CIGS SHOULD QUICKLY BECOME VFR
CIGS WITH A CHANCE OF BRIEF MVFR CONDITION SHOWERS AND THUNDERSTORMS...
ESPECIALLY 12Z-17Z. GRADIENT WEST WIND GUST 20 KT.
THURSDAY THROUGH SATURDAY...MAINLY VFR. SMALL CHANCE OF A LIGHT
SHOWER IN E PA OR NW NJ MIDDAY THURSDAY. GRADIENT WEST WIND GUST
20 KT THURSDAY AND 15 KT FRIDAY WITH EVEN LESS WESTERLY WIND
SATURDAY WHEN AFTERNOON COASTAL OCEAN AND BAY BREEZES PROBABLY
OCCUR.
&&
.MARINE...
THE PRESSURE GRADIENT WILL TIGHTEN TODAY INTO TONIGHT AHEAD OF AN
AMPLIFYING UPPER-LEVEL TROUGH. THIS WILL ALLOW FOR THE SURFACE WINDS
TO INCREASE WITH SOME ENHANCEMENT POSSIBLE PARTICULARLY UP DELAWARE
BAY. THE SOUNDINGS IN GENERAL INDICATE 25-30 KNOTS IN GUSTS AT THE
SURFACE AT TIMES, PROVIDED ENOUGH MIXING OCCURS. THE GUSTINESS IS
EXPECTED TO START DIMINISHING LATER THIS EVENING AS THE LOW-LEVEL
JET STARTS TO SHIFT EAST AHEAD OF AN ARRIVING COLD FRONT. THEREFORE,
WE WILL MAINTAIN THE END TIME OF THE SMALL CRAFT ADVISORY FOR
DELAWARE BAY AS IS /03Z THIS EVENING/. THE OCEAN ADVISORY RUNS RIGHT
THROUGH TONIGHT. THE STRENGTHENING FLOW WILL ALSO BUILD THE SEAS
ESPECIALLY ON THE COASTAL WATERS, AND WE WENT WITHIN A FOOT OF THE
WAVEWATCH GUIDANCE. IT APPEARS THAT SOME GUIDANCE THAT INDICATES
SOME NEAR GALE FORCE GUSTS TONIGHT IS PROBABLY OVERDONE WITH TO DEEP
OF A MIXING LAYER. THERE WILL BE THE CHC OF SOME THUNDERSTORMS
MAINLY LATE THIS AFTERNOON AND TONIGHT, WHICH COULD PRODUCE LOCALLY
ENHANCED WIND GUSTS.
OUTLOOK...
WEDNESDAY...WAVE HEIGHTS ARE ANTICIPATED TO REMAIN AROUND OR JUST
ABOVE 5 FEET. WIND SPEEDS MAY AGAIN INCREASE IN THE WEST NORTHWEST
FLOW ON WEDNESDAY AFTERNOON. THEREFORE, WE CONTINUE THE SMALL CRAFT
ADVISORY ON OUR OCEAN WATERS UNTIL 600 PM WEDNESDAY. IT MAY NEED
TO BE EXTENDED, IN TIME.
WEDNESDAY NIGHT...SMALL CRAFT ADVISORY CONDITIONS ARE POSSIBLE.
THURSDAY THROUGH SATURDAY...NO MARINE HEADLINES ARE ANTICIPATED.
&&
.TIDES/COASTAL FLOODING...
A CONTINUED EAST TO SOUTHEAST SURFACE FLOW SHOULD MAINTAIN THE
POTENTIAL FOR AT LEAST SOME LOCALIZED MINOR TIDAL FLOODING AROUND
TONIGHTS HIGH TIDE. THERE IS SOME UNCERTAINTY WHETHER OR NOT THE
DEPARTURES BECOME HIGH ENOUGH TO ALLOW THE WATER LEVELS TO REACH
OUR ADVISORY CRITERIA. AS A RESULT, WE OPTED TO HOLD OFF ON
ISSUING AN ADVISORY ATTM AND THE DEPARTURES WILL BE MONITORED
THROUGH THE DAY.
&&
.RIP CURRENTS...
DESPITE A DECREASED WAVE PERIOD TODAY, AN EAST TO SOUTHEAST WIND
WILL INCREASE TO 15-25 MPH AND SEAS IN THE SURF ZONE WILL BE 3-5
FEET. AS A RESULT, THERE IS A MODERATE RISK OF DANGEROUS RIP
CURRENTS THROUGH TONIGHT FOR BOTH THE NEW JERSEY AND DELAWARE
BEACHES.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ452>455.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 PM EDT
WEDNESDAY FOR ANZ450-451.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR ANZ430-
431.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GORSE/HEAVENER
SHORT TERM...GORSE
LONG TERM...DRAG
AVIATION...DRAG/GORSE/HEAVENER
MARINE...DRAG/GORSE
TIDES/COASTAL FLOODING...
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
939 PM EDT WED AUG 13 2014
.UPDATE...CONVECTION CONTINUES TO FADE AND WILL CONTINUE TO STEADILY
DECREASE POPS. WILL KEEP POPS GOING OFFSHORE AND ALSO INTRODUCE AGAIN
LATER TONIGHT TOWARDS THE GULF COAST AS DEEP AND MOIST WSW BRINGS IN
ANOTHER BAND OF SHOWERS/STORMS. MOISTURE POOLING TO THE SOUTH OF A
STALLED FRONT JUST TO THE NORTH MAY PRODUCE PATCHY FOG ACROSS THE
FAR NORTHERN (GA) ZONES.
&&
.AVIATION...PREVAILING VFR TONIGHT. MOS GUIDANCE SUGGESTS A CHANCE
OF MVFR VSBY AT GNV AND VQQ AND INCLUDED 5SM AROUND THE 09Z-12Z TIME
FRAME. LIKE PRIOR MORNINGS...MAY HAVE SHOWERS IN THE VICINITY AT GNV
THU MORNING AS CONVECTION MOVES OFF THE NE GULF OF MEXICO AND INTO
THE FL BIG BEND...AS INDICATED IN LATEST HRRR AND MESOSCALE MODELS.
KEPT A MENTION OF OCNL MVFR CONDITIONS IN SHOWERS AND STORMS
BEGINNING AT 14Z FOR GNV AND A COUPLE OF HOURS LATER FOR REST OF
TAFS. LIGHT SWLY WINDS TONIGHT AND THURSDAY WITH SPEEDS AOB 8 KNOTS.
&&
.MARINE...NO HEADLINES. NOCTURNAL SURGE WILL PRODUCE SW WINDS 15 KNOTS
OFFSHORE. SEAS 2 TO 3 FEET.
RIP CURRENTS: LOW RISK THRU THURSDAY WITH OFFSHORE FLOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 74 93 73 93 / 30 50 20 30
SSI 77 88 76 89 / 40 60 60 50
JAX 76 92 74 91 / 60 50 60 50
SGJ 75 91 75 88 / 50 50 40 70
GNV 74 90 73 90 / 60 60 40 70
OCF 74 90 73 90 / 30 60 50 70
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
PP/ARS/JDS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
320 PM EDT Tue Aug 12 2014
.Near Term [Through Tonight]...
A cold front continues to trek across the southeastern CONUS
today, with a convective boundary just east of AAF to FZG. This
is bringing scattered showers and thunderstorms to the area once
again. The HRRR is handling our atmospheric conditions pretty well
so far today, so adjusted PoPs toward recent runs. Coverage will
be highest in southeast Alabama, southwest Georgia, and over the
coastal waters. Some of these storms will last into the early
overnight hours, particularly near the AL-FL border. Showers over
our eastern coastal waters will likely generate once again in the
early hours of Wednesday morning. Highs today will be in the low-
mid 90s, around 90 along the coast, and lows tonight will be in
the low to mid 70s, with temperatures cooling the most in
southeast Alabama.
.Short Term [Wednesday Through Thursday Night]...
A surface cold front will slowly push southeast by tomorrow,
likely reaching the northern and northwest parts of our forecast
area. The front will not represent a significant transition in
surface temperatures as it stalls in the northern part of our area
in the next 24-36 hours, but there will be a fairly substantial
precipitable water and low-level dewpoint gradient across the
boundary. Behind the front, PWATs should fall to around 1.5 inches
by Thursday afternoon which is below the 20th percentile for
August at TLH. Ahead of the front, PWATs should remain above 2
inches which is slightly above normal. This configuration should
limit rain chances in the northern and northwest parts of our
forecast area both Wednesday and Thursday. However, showers and
storms will be likely in the southeastern part of our area,
especially closer to the Suwannee River. Both high-resolution and
global models suggest a continuation of the recent convective
timing: thunderstorms quickly develop and expand in coverage
offshore in the 06-12Z timeframe, and then affect the coastal
areas and the Florida Big Bend in the morning hours, with more
scattered development in the afternoon elsewhere. We followed this
trend in our forecast. Highs may be limited in the coastal areas
and the Florida Big Bend where early cloud cover and rain is more
likely. Elsewhere mid-90s seem likely inland.
There will be the potential for locally heavy rainfall and
isolated flooding during the period - mainly in the Florida Big
Bend and especially in the Taylor, Dixie, and Lafayette County
area. KTLH radar has already indicated 2-4" of rain in much of
those counties since Monday morning, with convection-allowing
models indicating isolated additional rainfall of upwards of 5"
will be possible by Wednesday evening. More on this in the
hydrology section.
.Long Term [Friday Through Tuesday]...
A drier air mass should continue to advect into the area for
Friday and Saturday, which should reduce rain chances over much of
our forecast area except for perhaps the far southeast corner.
PWAT values are then forecast to increase again from Sunday into
early next week to more normal levels as deeper southwest flow
sets up. Temperatures should be relatively close to normal.
&&
.Aviation...
[Through 18Z Wednesday] Scattered to numerous convection is
expected to develop once again this afternoon and coverage is
more than sufficient to warrant an explicit mention in the TAFs.
VFR will prevail for the most part, with the exception of drops to
MVFR for storms near the terminals.
&&
.Marine...
Showers and thunderstorms should be fairly widespread across the
coastal waters for the next several mornings ahead of a stalling
cold front just to the north. Winds and seas may be higher near
storms. Through Wednesday evening, winds of 10-15 knots should
create widespread 2-3 foot seas. Weaker winds thereafter will
promote seas of 2 feet or less.
&&
.Fire Weather...
Despite a drier airmass moving into the region this week, relative
humidity values will remain above critical thresholds. Red flag
criteria will not be met.
&&
.Hydrology...
There will be a chance for some isolated flooding in the Florida
Big Bend in the next couple days - particularly in Dixie, Taylor,
and Lafayette Counties. Radar estimates indicate that 2-4 inches
of rain has fallen across much of those counties since Monday
morning. While average rain totals through Thursday should be on
the order of 2-3 inches, isolated amounts at least double that
could contribute to localized areas of flooding. Elsewhere, slow-
moving storms and a moist atmosphere mean that flooding can`t be
ruled out in the remainder of the Florida Panhandle and Big Bend,
as well as extreme southern Georgia. However, localized flooding
is less likely in those areas.
Any flooding would likely be confined to urban areas, low-lying
spots, or smaller basins and streams (if it occurs).
&&
.Preliminary Point Temps/PoPs...
Tallahassee 74 93 74 95 73 / 30 60 20 40 20
Panama City 79 91 77 91 76 / 30 40 20 30 20
Dothan 72 94 71 94 71 / 30 30 20 20 10
Albany 73 94 71 94 70 / 30 30 20 20 10
Valdosta 73 95 72 95 72 / 30 60 20 40 20
Cross City 75 91 74 91 73 / 40 60 20 60 30
Apalachicola 78 90 77 90 76 / 30 60 20 40 20
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...MOORE
SHORT TERM...LAMERS
LONG TERM...LAMERS
AVIATION...MOORE
MARINE...LAMERS
FIRE WEATHER...MOORE
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS MIAMI FL
148 AM EDT TUE AUG 12 2014
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE BULK OF THE TAF
PERIOD AS HIGH PRESSURE REMAINS IN CONTROL. WINDS WILL REMAIN CALM
THROUGH MID-MORNING HOURS BEFORE TURNING ONSHORE AND INCREASING
INTO THE 5-10 KT RANGE ALONG BOTH COASTS AS THE SEA BREEZES
DEVELOP AND PUSH INLAND THROUGH THE AFTERNOON HOURS. THE BEST
CHANCE FOR AFTERNOON SHOWERS WILL REMAIN INLAND AND POSSIBLY
AROUND PBI LATE IN THE DAY (WILL INCLUDE VCTS AT PBI AFTER 21Z).
/AG
&&
.PREV DISCUSSION... /ISSUED 843 PM EDT MON AUG 11 2014/
UPDATE...
CONVECTION HAS HELD ON A LITTLE LONGER THAN PREVIOUS THINKING.
HOWEVER, IT IS BEGINNING TO DIMINISH IN MANY ARES. BUT, DEVELOP IN
PORTIONS OF PALM BEACH COUNTY. THE HRRR IS NOT DOING TO WELL ON PICKING
UP ON THE CONTINUING CONVECTION. SO HAVE ANTICIPATED, BASED ON THE
CURRENT TRENDS, THAT IT WILL CONTINUE TO MOVE SLOWLY EAST AND
CONTINUE TO SHRINK IN COVERAGE OVER THE NEXT COUPLE OF HOURS,
ESPECIALLY IN PALM BEACH AS OBS DO NOT SHOW ANY SIGNIFICANT
EASTERLY FLOW TO KEEP THEM TO THE WEST OF THE COAST FROM WEST PALM
BEACH NORTH, WHERE PRECIPITATION IS ALREADY ENCROACHING ON THE
AREA. SOUTH OF THERE, CONVECTION IS FURTHER WEST, AND SHOWING
SIGNS OF WEAKENING.
PREV DISCUSSION... /ISSUED 719 PM EDT MON AUG 11 2014/
AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST WITH LIGHT
SURFACE WINDS. EXPECT L/V WIND THROUGH EARLY TUESDAY WITH SEA
BREEZES DEVELOPING ALONG BOTH COASTS AFT 14-16Z. THESE BOUNDARIES
WILL GENERATE SCATTERED SHRA/TSRA WITH VERY LITTLE STORM MOTION.
DUE TO THE SLOW MOVEMENT, THE PROBABILITY OF A CELL MOVING ACROSS
A TERMINAL IS VERY SMALL AND WILL NOT MENTION IN THE TAFS AT THIS
TIME.
KOB
PREV DISCUSSION... /ISSUED 258 PM EDT MON AUG 11 2014/
SHORT TERM...(TODAY-WEDNESDAY)...
BASED ON THIS MORNING`S SOUNDING AND OTHER DATA...A SAHARAN AIR
LAYER IS PRESENT TODAY ESPECIALLY WHEN LOOKING AT THE H85-H7
PORTION OF THE SOUNDING...AND SHOULD HELP LIMIT COVERAGE TODAY.
HOWEVER A FEW SLOW MOVING CELLS WERE PERSISTING ALONG THE SEA
BREEZE THROUGH CENTRAL DADE AND SOUTHEAST BROWARD. WITH WEAK FLOW
THESE STORMS WILL BE SLOW MOVING AND COULD PRODUCE VERY HEAVY
RAINFALL LEADING TO WATER PROBLEMS ALONG TYPICAL FLOOD PRONE
STREETS. MORE DEVELOPMENT IS STILL EXPECTED THROUGH THE INTERIOR
AND CAN`T RULE OUT ADDITIONAL DEVELOPMENT NEAR THE CITIES OR THE
COASTS LATE THIS AFTERNOON OR THIS EVENING. THE DEEP LAYER RIDGE
WILL REMAIN IN PLACE TOMORROW...BUT WILL WEAKEN EVENTUALLY INTO
WEDNESDAY AS ANOTHER UPPER TROUGH DIVES ACROSS THE GREAT LAKES AND
INTO THE MIDDLE ATLANTIC. IN ADDITION...A FEW WEAK DISTURBANCES
NOW MOVING ACROSS CUBA WILL BE PULLED BACK NORTH IN RESPONSE TO A
TROUGH ENTERING THE SOUTHEAST COAST. THIS COULD LEAD TO MORE
DEVELOPMENT IN COMPARISON TO WHAT IS EXPERIENCED FOR THE REST OF
TODAY AND TUESDAY. PWATS ARE ALSO FORECAST TO RISE CLOSER TO 2"
AGAIN ON WEDNESDAY PER MODEL SOUNDINGS. A GENERALLY SOUTHERN WIND
DIRECTION WILL CONTINUE THROUGH THE SHORT TERM...AND THE BEST
CHANCE FOR SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGH THE
INTERIOR SECTIONS INTO WEDNESDAY.
LONG TERM...(THURSDAY-SUNDAY)...
THE LATEST EXTENDED GUIDANCE REMAINS IN DECENT AGREEMENT AND
GENERALLY INDICATES THE DEEP LAYER RIDGE REMAINING IN CONTROL ACROSS
THE REGION THROUGH THURSDAY. THIS COMBINED WITH PLENTY OF MID/UPPER
DRY AIR SHOULD KEEP THE RAIN CHANCES BELOW NORMAL WITH MAINLY
SCATTERED AFTERNOON SHOWERS ACROSS THE INTERIOR/LAKE REGION EACH
AFTERNOON. THE DEEP LAYER RIDGE IS PROGGED TO SLIGHTLY WEAKEN FRIDAY
INTO THE UPCOMING WEEKEND AS AN UPPER TROUGH DEEPENS ONCE AGAIN
ACROSS THE EASTERN STATES AND A WEAKENING FRONTAL BOUNDARY
ASSOCIATED WITH A SHORTWAVE TROUGH PUSHES SOUTH ACROSS THE REGION.
THIS COULD TRANSLATE TO SW LOW LEVEL FLOW AND INCREASING MOISTURE
AND RAIN CHANCES EACH DAY THROUGH THE WEEKEND ACROSS THE LOCAL AREA.
AVIATION...
SHOWERS ARE JUST STARTING TO POP UP TO THE WEST OF TERMINALS KFLL
AND KOPF AND KMIA. THEREFORE EAST COAST TERMINALS EITHER ASSIGNED
VCTS AT 18Z OR 19Z ESPECIALLY AS THE EAST COAST SEA BREEZE
CONTINUES TO PUSH FURTHER INLAND. THE SEA BREEZE NEAR KPBI HAS
NOT FORMED WITH A WEAK WESTERLY WIND AT TAF ISSUANCE WITH A WEAK
SEA BREEZE ASSIGNED AT 19Z. WITH ON-SET OF WEST COAST SEA BREEZE
ALREADY UNDERWAY...CONVECTION IS EXPECTED MAINLY INLAND OF
TERMINAL KAPF. WHILE CONVECTION IS EXPECTED TO BE MAINLY INLAND
AND WEST OF THE EASTERN TERMINALS...THERE COULD BE BRIEF PERIODS
OF SUB- VFR CONDITIONS WITH OCCURRENCE OF SHOWERS/THUNDERSTORMS.
MARINE...
HIGH PRESSURE WILL REMAIN IN CONTROL ACROSS THE MARINE AREAS THROUGH
MUCH OF THE WEEK WITH GENERALLY SOUTH WINDS 5-10 KTS EXPECTED.
MINOR STREET FLOODING OR STANDING WATER OVER THE TYPICAL MIAMI BEACH
AREAS ALONG THE BAY SIDE WILL REMAIN POSSIBLE THROUGH TUESDAY
MORNING`S HIGH TIDE DUE TO THE LUNAR PERIGEE. REPORTS FROM SUNDAY
EVENING`S HIGH TIDE INDICATED A SMALL AMOUNT OF WATER ON THE
STREETS...HOWEVER...NOT ENOUGH TO CLOSE ROADS OR FOR A COASTAL FLOOD
STATEMENT. THE UPCOMING HIGH TIDES WILL BE AT OR AROUND: 940 AM
TODAY AND 1009 PM THIS EVENING...WHICH ARE PREDICTED TO BE
SLIGHTLY HIGHER THAN SUNDAY`S HIGH TIDE CYCLES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 79 90 79 / 20 10 30 10
FORT LAUDERDALE 92 82 91 82 / 20 10 30 10
MIAMI 92 81 91 80 / 20 10 40 10
NAPLES 94 77 92 77 / 20 10 30 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....21/KM
AVIATION...60/BD
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
1117 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A PRESSURE TROUGH WILL LINGER IN THE FORECAST AREA TODAY AHEAD OF
AN APPROACHING COLD FRONT. THE FRONT WILL MOVE INTO THE AREA LATE
TONIGHT AND EXTEND ALONG THE COAST WEDNESDAY. SHOWERS AND
THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING...THEN DRIER
WEATHER SHOULD FOLLOW THE FRONT FOR THE REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MORNING STRATUS AND FOG ACROSS THE AREA HAS LIFTED WITH
TEMPERATURES ALREADY PUSHING INTO MID 80S WITH DEWPOINTS IN THE
MID 70S. VISIBLE SATELLITE IMAGERY SHOWING SOME CUMULUS CLOUDS
BEGINNING TO FORM AS CONVECTIVE TEMPERATURES ARE BEING REACHED.
MESOANALYSIS INDICATES PRECIPITABLE WATER VALUES STILL AROUND 2
INCHES THIS MORNING WHICH ALONG WITH DEWPOINTS IN THE 70S AND
SURFACE HEATING SHOULD LEAD TO AFTERNOON SHOWERS AND THUNDERSTORMS
AS AN UPPER TROUGH MOVES CLOSER TO THE REGION. WATER VAPOR IMAGERY
ALSO SHOWING DRIER AIR WILL WORK INTO THE REGION FROM THE WEST
LATE AFTERNOON AND EVENING WHICH COULD SUPPORT THE THREAT FOR
ISOLATED STRONG TO POSSIBLE SEVERE STORMS WITH DAMAGING WIND GUSTS
WITHIN MULTICELL SEGMENTS. HI-RES MODELS AND HRRR SHOWING STORMS
DEVELOPING OVER THE AREA MID AFTERNOON AND SHIFTING EASTWARD
ACROSS THE FORECAST AREA INTO EARLY EVENING AND WILL CONTINUE THE
LOW END LIKELY POPS FOR MUCH OF THE FORECAST AREA. MAX
TEMPERATURES EXPECTED IN THE LOWER 90S WITH HEAT INDICES CLOSE TO
100 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
THE MODELS DISPLAY THE WEAKENING COLD FRONT IN THE COASTAL PLAIN
WEDNESDAY AND ALONG THE COAST WEDNESDAY NIGHT. ANY CONVERGENCE
ASSOCIATED WITH THE FRONT NEAR THE EAST PART OF THE FORECAST AREA
SHOULD BE WEAK WITH H85 WESTERLY FLOW. THE MODELS ARE CONSISTENT
WITH JUST SHALLOW MOISTURE. ALL THE NAM AND GFS MOS HAVE POPS
LESS THAN 20 PERCENT. SUNSHINE AND DOWNSLOPE FLOW WILL RESULT IN
WARM TEMPERATURES WEDNESDAY BUT RELATIVE HUMIDITIES WILL BE LOWER
THAN WHAT WE HAVE EXPERIENCED LATELY. THE TEMPERATURE GUIDANCE WAS
CLOSE WITH HIGHS MAINLY IN THE LOWER 90S. USED THE GUIDANCE
CONSENSUS FOR THE LOWS WEDNESDAY NIGHT. EXPECT TEMPERATURES WILL
FALL INTO THE MIDDLE AND UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE GFS AND ECMWF SHOW THE REMNANTS OF THE COLD FRONT NEAR THE
FORECAST AREA THURSDAY AND FRIDAY WITH WEAK TROUGHING.
HOWEVER...DEEP MOISTURE REMAINS SUPPRESSED EAST OF THE AREA AHEAD
OF THE EAST COAST UPPER TROUGH. THE GFS...ECMWF...AND EKD MOS HAVE
POPS LESS THAN 20 PERCENT. MOISTURE MAY INCREASE BEGINNING
SATURDAY BUT SHOULD REMAIN LIMITED BECAUSE BOTH THE GFS AND ECMWF
DISPLAY SURFACE RIDGING EXTENDING FROM THE ATLANTIC WESTWARD ALONG
THE GULF COAST. THE GFS...ECWMF...AND EKD MOS HAVE POPS 20 TO 30
PERCENT SATURDAY THROUGH MONDAY WITH THE HIGHER POPS MAINLY
MONDAY. THE GUIDANCE HAS TEMPERATURES NEAR CLIMATOLOGY THROUGH THE
MEDIUM-RANGE PERIOD.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
MORNING FOG/STRATUS HAS LIFTED AND CONDITIONS AT ALL TERMINALS
HAVE RETURNED TO VFR. SCATTERED CONVECTION WILL DEVELOP BY LATE
AFTERNOON AHEAD OF AN APPROACHING COLD FRONT. WILL USE VCSH FOR
ALL TAF SITES FROM AROUND 20Z TO AROUND 03Z THIS EVENING...BUT
HAVE SOME LOW CONFIDENCE WITH TIMING AND EXTENT OF THUNDER. SOME
MVFR FOG POSSIBLE BEFORE DAWN WEDNESDAY MORNING...BUT NOT ENOUGH
CONFIDENCE TO MENTION AT THIS TIME.
EXTENDED AVIATION OUTLOOK...POSSIBLE MVFR RESTRICTIONS EARLY
WEDNESDAY MORNING. OTHERWISE NO SIGNIFICANT RESTRICTIONS EXPECTED.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
FORECAST DISCUSSION BELOW.
20
PREVIOUS LONG TERM DISCUSSION /TUESDAY NIGHT THROUGH SUNDAY/...
CLOSED UPPER LOW SPINNING OVER THE NORTHEAST STATES SHOULD KEEP A
BROAD TROUGH OVER THE EASTERN STATES THROUGH MUCH OF THE
PERIOD...WITH GEORGIA REMAINING UNDER A NORTHWEST UPPER FLOW.
MODELS PERSIST WITH A DRYING TREND FOR WEDNESDAY INTO FRIDAY SO
HAVE CONTINUED WITH NO POPS NORTH FOR THAT PERIOD. STILL LOOKING
FOR SOME BELOW NORMAL TEMPERATURES...ESPECIALLY OVERNIGHT FOR THE
MIDDLE OF THE WEEK. AS FRONTAL BOUNDARY SINKS SOUTH...SOME
CONVECTION POSSIBLE NEAR THE BOUNDARY IN CENTRAL GEORGIA. BY THE
END OF THE LONG TERM...MODELS SHOWING SOME INCREASE IN MOISTURE SO
HAVE INTRODUCED CHANCE POPS BACK ACROSS THE FORECAST AREA.
41
&&
.AVIATION...
06Z UPDATE...
VFR EVERYWHERE AT TAF TIME BUT EXPECT CIGS TO LOWER BEGINNING
AROUND 08-09Z. EXPECT MVFR TO BRIEFLY IFR CIGS BY AROUND 12Z WITH
A GRADUAL IMPROVING TREND THROUGH 17Z...BUT CONDITIONS MAY CLEAR
MORE QUICKLY THAN THAT. OTHER CONCERN IS AREA OF TSRA ACROSS
METRO...HAVE INCLUDED TEMPO TO COVER THROUGH 07Z. CONTINUED TREND
OF PROB30 FOR THIS AFTERNOON BUT CONFIDENCE LOWER FOR ANY IMPACTS
TO METRO TAFS. EXPECT VFR EVERYWHERE AFTER THE FRONT PUSHES
THROUGH AFTER 00Z. WINDS GENERALLY W THROUGH THE PERIOD AROUND 5KT
WITH LOW-END GUSTS POSSIBLE AT ATL.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON CIGS THIS MORNING...ESPECIALLY TIMING OF LIFTING.
MEDIUM ON DEVELOPMENT OF CONVECTION THIS AFTERNOON...LOW ON
IMPACTS TO ATL.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 89 70 89 64 / 30 20 5 5
ATLANTA 87 69 88 66 / 30 20 5 10
BLAIRSVILLE 82 63 80 58 / 30 20 5 5
CARTERSVILLE 86 66 87 62 / 30 20 5 5
COLUMBUS 90 73 91 70 / 30 20 5 10
GAINESVILLE 86 68 87 64 / 30 20 5 5
MACON 90 72 93 68 / 40 30 10 20
ROME 87 65 88 62 / 30 20 5 5
PEACHTREE CITY 88 68 88 64 / 30 20 5 10
VIDALIA 93 74 93 73 / 60 50 30 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
229 AM CDT TUE AUG 12 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PATCHY IFR CIGS DEVELOPING EARLY THIS MORNING...SHUD IMPROVE TO
LOW END MVFR BY 12Z.
* NW WINDS TURNING N WITH A FEW GUSTS TO 20KT BEFORE 12Z...THEN
FREQUENT GUSTS AFT 14Z UP TO 24KT.
* PATCHY LGT SHRA THRU 10Z.
BEACHLER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE HAS PUSHED EAST INTO SOUTHEAST MICHIGAN EARLY THIS
MORNING...WITH WINDS GENERALLY FROM 300-330 DEG ACROSS THE TAF
SITES AND ALL OTHER NORTHERN IL/NORTHWEST IN AIRFIELDS. CIGS HAVE
BEEN STEADILY DIMINISHING INTO LOW END MVFR CONDS...WITH PSBL CIGS
DIPPING TO ARND 1KFT AGL JUST BEFORE DAYBREAK. IR IMAGERY SHOWS
THE WRAP AROUND MOISTURE AND CLOUDS PIVOTING EAST ACROSS NORTHERN
IL INTO NORTHWEST IN THIS MORNING...WITH MUCH DRIER AIR ACROSS
NORTHWEST WISC SLOWLY SLIDING SOUTHEAST TOWARDS THE TAF SITES. IT
DOES APPEAR THAT AFT THE BRIEF PERIOD OF LGT SHRA CIGS WILL ONLY
REBOUND FOR MUCH OF THE DAY INTO LOW END MVFR CONDS...OR ARND
2100-2900FT AGL. THEN LATE THIS AFTN ENOUGH DRY AIR SHUD PUSH INTO
THE TAF SITES TO SCT CIGS AND PUSH THEM BACK TO VFR CONDS.
WINDS WILL BE TURNING NORTHERLY AND WITH BETTER MIXING EXPECT
SPEEDS TO INCREASE SHORTLY AFT DAYBREAK TO ARND 10-14KT. GUSTS
WILL ALSO DEVELOP AND GUIDANCE IS INDICATING GUSTS TO TOP OUT ARND
22-24KT BY 14Z THRU 02Z WED OR SHORTLY AFT SUNSET WINDS WILL
DIMINISH.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LGT SHRA ONLY LASTING FOR A FEW HOURS THIS
MORNING.
* HIGH CONFIDENCE IN WIND DIR/SPEED AND GUSTS LATER TODAY.
* MEDIUM/HIGH CONFIDENCE IN CIGS HOVERING ARND LOW END MVFR
CONDS...LOW CONFIDENCE IN CIGS DIPPING TO IFR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. WX NIL. NORTHWEST WINDS WITH POSSIBLE SHIFT TO
NORTHEAST WITH LAKE BREEZE.
THURSDAY...VFR. WX NIL. NORTHEAST WINDS UP TO 10KT.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN SOUTHEAST WITH LAKE BREEZE IN
THE AFTERNOON. SLIGHT CHANCE TSRA OVERNIGHT.
SATURDAY AND SUNDAY...SOUTH WINDS TO 10 KT. SLIGHT CHANCE TSRA
OVERNIGHT.
KREIN
&&
.MARINE...
217 AM CDT
MAIN ISSUES FOR TODAY WILL BE ON POTENTIAL GALES FOR THE NORTHERN
HALF OF THE LAKE...AND DEVELOPING SMALL CRAFT CONDITIONS FOR THE
ILLINOIS AND NORTHWEST INDIANA NEARSHORE WATERS.
WINDS LATE LAST NIGHT BEGAN TO INCREASE ACROSS THE NORTHERN HALF
OF THE LAKE...WITH A COUPLE SITES TOUCHING GALE CONDITIONS. THOSE
SITES HAVE SINCE DIMINISHED TO GUSTS BETWEEN 28-30KT. THERE IS
SOME COOLER AIR FLOWING ACROSS THE LAKE AND THE GRADIENT HAS BEEN
A LITTLE TIGHTER...WHICH COULD STILL SUPPORT SOME DEGREE OF
FREQUENT GALES. THE LOW WILL CONTINUE TO LIFT NORTHEAST THROUGHOUT
THE DAY...ALLOWING BROAD SFC RIDGE TO PUSH IN FROM THE WEST. THIS
WILL ALLOW WINDS TO STEADILY DIMINISH LATER THIS
AFTN/EVE...HOWEVER WAVES WILL REMAIN HAZARDOUS TO SMALL CRAFT IN
THE SOUTHERN TIP OF THE LAKE. THIS WILL ESPECIALLY BE TRUE FOR THE
INDIANA NEARSHORE WATERS. THEN HIGH PRESSURE ARRIVES WED AND
LINGERS THRU FRI...THEN HIGH PRESSURE DRIFTS EAST WITH FLOW
TURNING SOUTHERLY TO SOUTHWESTERLY FOR THE WEEKEND.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 AM CDT TUE AUG 12 2014
.DISCUSSION...
257 PM CDT
NEAR TERM FORECAST FOCUS DEALS SHOWER/THUNDERSTORM COVERAGE THROUGH
THIS EVENING...AND ADDITIONAL SHOWER CHANCES THROUGH AT LEAST
TUESDAY MORNING ESPECIALLY OVER EASTERN PARTS OF THE FORECAST AREA.
EARLY AFTERNOON SURFACE ANALYSIS DEPICTS TWO SEPARATE AREAS OF LOW
PRESSURE...ONE OVER CENTRAL WISCONSIN AND THE OTHER ACROSS WESTERN
OHIO. BOTH OF THESE SURFACE LOWS WERE ASSOCIATED WITH FAIRLY STOUT
MID-LEVEL SHORT WAVES WHICH WERE ALSO RESPONSIBLE FOR A LARGE AREA
OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WI ACROSS LAKE MICHIGAN
TO THE SOUTHERN GREAT LAKES/OHIO VALLEY REGION THIS AFTERNOON. FOR
OUR LOCAL AREA...THE STRONG SHORT WAVE TROUGH SEEN IN GOES VAPOR
IMAGERY OVER MINNESOTA WILL BE THE MAIN DRIVER IN OUR WEATHER AND
PRECIP TRENDS OVER THE NEXT 18 HOURS OR SO...AS IT CONTINUES TO DIG
SOUTHEAST ACROSS NORTHERN IL THROUGH TUESDAY MORNING. ALONG WITH ITS
SURFACE REFLECTION OVER WI...A COLD FRONT EXTENDING ALONG THE
MISSISSIPPI RIVER WILL PUSH SOUTHEAST THROUGH THIS EVENING...AND
WILL BE THE FOCUS FOR SHOWERS AND A FEW THUNDERSTORMS. WHILE SURFACE
WINDS WERE ALREADY WEST-NORTHWEST AHEAD OF THE FRONT ITSELF...THUS
REDUCING CONVERGENCE ALONG THE BOUNDARY...STEEP LOW LEVEL LAPSE
RATES AND RAP MESOANALYSIS MLCAPES OF 500-1000 J/KG SHOULD BE ENOUGH
TO SUSTAIN SHOWERS/THUNDERSTORMS AHEAD OF THE FRONT THROUGH EARLY
EVENING. IN ADDITION...A FEW SHOWERS HAD DEVELOPED ALONG THE LAKE
BREEZE FROM SOUTHEAST WI INTO NORTHEAST IL...AND THESE SHOWERS AND
ISOLATED THUNDERSTORMS MAY ALSO FESTER A BIT AHEAD OF THE FRONT. ANY
OF THE STRONGER STORMS MAY PRODUCE BRIEF HEAVY DOWNPOURS...AND
PERHAPS SOME BRIEF GUSTY WINDS WITH STORMS ALONG THE FRONT DUE TO
THE STEEP LOW LEVEL LAPSE RATES.
THE STRONG MINNESOTA SHORT WAVE WILL AMPLIFY/DEEPEN AN UPPER TROUGH
OVER THE WESTERN LAKES TONIGHT...WITH THE SURFACE LOWS CONSOLIDATING
AND DEEPENING OVER LOWER MICHIGAN. A FEW SHOWERS MAY LINGER OVER
NORTHEASTERN PARTS OF THE CWA AND SOUTHERN LAKE MICHIGAN TUESDAY
MORNING AS THE MAIN VORT MOVES THROUGH...BEFORE SUBSIDENCE INDICATED
BY 40 METER H5 HEIGHT RISES SPREADS IN DURING THE AFTERNOON. NORTH
WINDS STRENGTHENING BEHIND THE DEEPENING LOW WILL EVENTUALLY PULL
COOLER AND DRIER AIR INTO THE REGION TUESDAY AFTERNOON/NIGHT. AFTER
TEMPS REACHING THE LOW 80S TODAY (WHERE CLOUDS DID NOT PREVENT
IT)... COOLER 70S EXPECTED FOR HIGHS TUESDAY...AND SOME LOW 50S FOR
LOWS TUESDAY NIGHT!
GUIDANCE INDICATES ANOTHER WEAKER SHORT-WAVE DROPPING SOUTHEAST
ACROSS THE WESTERN LAKES WEDNESDAY...WITH A WEAK SURFACE WAVE AND
TROUGH PUSHING SOUTH ACROSS THE REGION DURING THE AFTERNOON. SOME
MODELS ARE TRYING TO SQUEEZE OUT A LITTLE PATCHY LIGHT QPF HINTING
AT SOME SHOWERS ALONG/AHEAD OF THE TROUGH DURING THE AFTERNOON...
THOUGH MOST OF THIS IS ACROSS WI/NORTHEAST IA AND HAVE LOW ENOUGH
CONFIDENCE IN IT IMPACTING THE FORECAST AREA TO LEAVE IT OUT OF THE
FORECAST AT THIS TIME. SIMILAR POTENTIAL FOR THURSDAY AFTERNOON
FARTHER SOUTH DEPENDING UPON WHERE THE TROUGH IS BY THEN. OTHERWISE
HIGH PRESSURE BUILDS INTO THE REGION WEDNESDAY NIGHT AND THURSDAY
WITH LIGHTER WINDS AND A MODERATION IN TEMPS BACK TO THE 75-80
DEGREE RANGE THURSDAY AND AROUND 80 FRIDAY WITH ATTENDANT LAKE
BREEZES. THE HIGH THEN DRIFTS OFF TO THE EAST FRIDAY NIGHT AND
SATURDAY...WITH AN EVENTUAL RETURN OF WARM/MOIST ADVECTION FLOW INTO
THE WEEKEND AND EARLY NEXT WEEK. IN THE EXTENDED RANGE...GEM...GFS
AND ECMWF ALL BRING SOME PRECIP POTENTIAL BACK TO THE AREA BY FRIDAY
NIGHT...THOUGH THERE ARE SOME TIMING DIFFERENCES BETWEEN THE GLOBAL
GUIDANCE BY DAYS 6-7. THUS HAVE MAINTAINED BLENDED GUIDANCE APPROACH
WITH GENERALLY LOW-CHANCE POPS AND TEMPS WARMING BACK INTO THE
LOW-MID 80S THROUGH THE WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PATCHY IFR CIGS DEVELOPING EARLY THIS MORNING...SHUD IMPROVE TO
LOW END MVFR BY 12Z.
* NW WINDS TURNING N WITH A FEW GUSTS TO 20KT BEFORE 12Z...THEN
FREQUENT GUSTS AFT 14Z UP TO 24KT.
* PATCHY LGT SHRA THRU 10Z.
BEACHLER
//DISCUSSION...UPDATED 06Z...
LOW PRESSURE HAS PUSHED EAST INTO SOUTHEAST MICHIGAN EARLY THIS
MORNING...WITH WINDS GENERALLY FROM 300-330 DEG ACROSS THE TAF
SITES AND ALL OTHER NORTHERN IL/NORTHWEST IN AIRFIELDS. CIGS HAVE
BEEN STEADILY DIMINISHING INTO LOW END MVFR CONDS...WITH PSBL CIGS
DIPPING TO ARND 1KFT AGL JUST BEFORE DAYBREAK. IR IMAGERY SHOWS
THE WRAP AROUND MOISTURE AND CLOUDS PIVOTING EAST ACROSS NORTHERN
IL INTO NORTHWEST IN THIS MORNING...WITH MUCH DRIER AIR ACROSS
NORTHWEST WISC SLOWLY SLIDING SOUTHEAST TOWARDS THE TAF SITES. IT
DOES APPEAR THAT AFT THE BRIEF PERIOD OF LGT SHRA CIGS WILL ONLY
REBOUND FOR MUCH OF THE DAY INTO LOW END MVFR CONDS...OR ARND
2100-2900FT AGL. THEN LATE THIS AFTN ENOUGH DRY AIR SHUD PUSH INTO
THE TAF SITES TO SCT CIGS AND PUSH THEM BACK TO VFR CONDS.
WINDS WILL BE TURNING NORTHERLY AND WITH BETTER MIXING EXPECT
SPEEDS TO INCREASE SHORTLY AFT DAYBREAK TO ARND 10-14KT. GUSTS
WILL ALSO DEVELOP AND GUIDANCE IS INDICATING GUSTS TO TOP OUT ARND
22-24KT BY 14Z THRU 02Z WED OR SHORTLY AFT SUNSET WINDS WILL
DIMINISH.
BEACHLER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LGT SHRA ONLY LASTING FOR A FEW HOURS THIS
MORNING.
* HIGH CONFIDENCE IN WIND DIR/SPEED AND GUSTS LATER TODAY.
* MEDIUM/HIGH CONFIDENCE IN CIGS HOVERING ARND LOW END MVFR
CONDS...LOW CONFIDENCE IN CIGS DIPPING TO IFR.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR. WX NIL. NORTHWEST WINDS WITH POSSIBLE SHIFT TO
NORTHEAST WITH LAKE BREEZE.
THURSDAY...VFR. WX NIL. NORTHEAST WINDS UP TO 10KT.
FRIDAY...VFR. LIGHT SOUTH WINDS TURN SOUTHEAST WITH LAKE BREEZE IN
THE AFTERNOON. SLIGHT CHANCE TSRA OVERNIGHT.
SATURDAY AND SUNDAY...SOUTH WINDS TO 10 KT. SLIGHT CHANCE TSRA
OVERNIGHT.
KREIN
&&
.MARINE...
403 PM CDT
THE HIGHER WINDS AND WAVES FROM EARLIER THIS MORNING HAVE SINCE
DIMINISHED/SUBSIDED TODAY AS A WEAKER SURFACE GRADIENT HAS SETTLED
IN...BETWEEN WEAKENING LOW PRESSURE WEST OF THE LAKE AND A
NORTHWARD MOVING LOW PRESSURE OVER THE OHIO VALLEY. THE GENERALLY
LIGHTER WINDS CURRENTLY OVER THE LAKE WILL OBSERVE AN INCREASING
TREND THIS EVENING INTO TONIGHT AS THE OHIO VALLEY LOW DEEPENS
WHILE LIFTING THROUGH THE EASTERN GREAT LAKES...WITH NORTHERLY TO
30 KT WINDS LIKELY BY LATE TONIGHT AND EARLY TUESDAY MORNING.
LATEST TRENDS HAVE SHOWN THAT NORTHERLY GALES WILL BE POSSIBLE
TUESDAY MORNING INTO TUESDAY AFTERNOON MAINLY FOR THE NORTHERN
HALF OF THE LAKE...INSTEAD OF THE PREVIOUSLY MENTIONED OCCASIONAL
GALE FORCE GUSTS. WITH THIS POSSIBILITY...HAVE ISSUED A GALE WATCH
FOR THE NORTH HALF THIS AFTERNOON FOR THIS PERIOD. WILL NEED TO
CONTINUE TO MONITOR LATER TRENDS FOR THIS INCREASED POSSIBILITY OF
GALES. THESE NORTHERLY WINDS WILL ALLOW WAVES TO BUILD DOWN THE
LENGTH OF THE LAKE...WITH WINDS AND WAVES HAZARDOUS FOR SMALL
CRAFT LIKELY TUESDAY INTO TUESDAY NIGHT AND WEDNESDAY MORNING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014...9 AM TUESDAY TO 4 AM
WEDNESDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565...7 AM
TUESDAY TO 3 PM TUESDAY.
SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742...9 AM TUESDAY TO 4
AM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 10
AM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
227 PM MDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A RIDGE WILL BE OVER THE ROCKIES TONIGHT AND A SURFACE TROUGH OVER
EASTERN COLORADO. SOME SCATTERED CUMULUS HAVE DEVELOPED OVER
EASTERN COLORADO. CURRENT RADAR WITH NO RETURNS. THE HRRR AND NAM
BOTH DO NOT INDICATE STORMS FOR THIS EVENING AND THAT SEEMS
REASONABLE BASED ON VERY DRY FORECAST SOUNDINGS OVER THE AREA.
ALSO WATER VAPOR IMAGERY SHOWING STRONG SUBSIDENCE EAST OF THE
CENTRAL ROCKIES. POPS WILL BE NIL TONIGHT AND AGAIN ON WEDNESDAY
AS SUBSIDENCE CONTINUES. LOW TEMPERATURES TONIGHT WILL BE IN THE
LOWER 60S AND MAX TEMPERATURES WEDNESDAY AROUND 90.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 152 PM MDT TUE AUG 12 2014
A DRY FORECAST CONTINUES THROUGH WEDNESDAY NIGHT AND EARLY THURSDAY
AS THE RIDGE AND SUBSIDENCE CONTINUES OVER THE HIGH PLAINS. BY
THURSDAY AFTERNOON THE RIDGE BREAKS DOWN SOME AS A SHORTWAVES
MOVES INTO THE AREA. THIS SHORTWAVE WILL CONTINUE MOVING ACROSS
THE FA THURSDAY NIGHT INTO FRIDAY MORNING. STORMS SHOULD INITIATE
ON A SURFACE TROUGH IN EASTERN COLORADO THURSDAY AFTERNOON AND
THEN SPREAD EAST ACROSS THE REST OF THE FA THURSDAY NIGHT. CHANCE
POPS LOOK GOOD FOR THIS EVENT. STORMS WILL LIKELY LINGER IN THE
EASTERN FA EARLY FRIDAY MORNING WITH SUBSIDENCE MOVING INTO THE FA
FROM WEST TO EAST. CONFIDENCE IS NOT HIGH FOR STORMS FRIDAY
AFTERNOON BUT CANNOT RULE OUT AT LEAST AN ISOLATED STORM OR TWO SO
WILL LOWER POPS TO SLIGHT CHANCE.
IN THE EXTENDED...FROM FRIDAY NIGHT THROUGH TUESDAY...A BROAD
RIDGE WILL BE OVER THE WESTERN CONUS EXTENDING INTO THE HIGH
PLAINS. NUMEROUS WEAK DISTURBANCES WILL MOVE THROUGH THE RIDGE
INTO THE HIGH PLAINS. THIS WILL PROVIDE POTENTIAL FOR STORMS EACH
AFTERNOON AND EVENING ACROSS THE FA THROUGH TUESDAY. CONSEQUENTLY, PLAN
TO HAVE AT LEAST A SLIGHT CHANCE OF STORMS EACH DAY. MAX
TEMPERATURES WILL REACH THE LOWER 90S EACH DAY. MIN TEMPERATURES
WILL BE IN THE LOWER TO MID 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1046 AM MDT TUE AUG 12 2014
VFR CONDITIONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. A WEAK SHORTWAVE PROGGED TO MOVE ACROSS THE AREA OVERNIGHT
WILL HAVE SOME MID LEVEL CLOUDS ASSOCIATED WITH IT BUT NO
PRECIPITATION. WINDS WILL BE LIGHT FROM THE SOUTHEAST IN RESPONSE
TO RETREATING HIGH PRESSURE AND A SURFACE TROUGH IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...FS
LONG TERM...FS
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1055 AM MDT TUE AUG 12 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 235 AM MDT TUE AUG 12 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW HIGHLY AMPLIFIED
RIDGE CENTERED OVER THE CENTRAL ROCKIES EXTENDING WELL INTO THE
CANADIAN ROCKIES. THE EASTERN EXTENT OF THIS RIDGE HAS SHIFTED OVER
OUR CWA...WITH THE MAIN STORM TRACK NOW WELL EAST. MONSOONAL PLUME
IS ALSO ORIENTATED MORE OVER THE GREAT BASIN THAT CENTRAL ROCKIES
WITH LITTLE IN THE WAY OF UPSTREAM ACTIVITY OVER THE NORTHERN PLAINS.
AT THE SURFACE HIGH PRESSURE REMAINS IN PLACE THE CENTRAL AND HIGH
PLAINS.
WITH H5 RIDGE NOW HOLDING MUCH MORE INFLUENCE ON WX OVER OUR
CWA...DRY CONDITIONS SHOULD CONTINUE THROUGH AT LEAST WEDNESDAY
AFTERNOON. GUIDANCE HAS SHIFTED TRACK OF A WEAK SHORTWAVE WEDNESDAY
NIGHT TOWARDS THE NORTHERN PLAINS...WITH EVEN THE SOUTHERNMOST
REFLECTION OF THIS BARELY INFLUENCING SW NEBRASKA. WITH THE PRECIP
SIGNAL SHIFTED NORTH AND A VERY DRY AIR MASS IN PLACE (ON ALL
AVAILABLE GUIDANCE) I REMOVED THUNDERSTORM MENTION FROM WEDNESDAY
NIGHT. BY THURSDAY A STRONGER SHORTWAVE WILL BEGIN TO BREAKDOWN THE
WESTERN PART OF THE RIDGE ALLOWING BETTER FORCING TO MOVE TOWARDS
THE PLAINS...AND WITH AT LEAST MODERATE INSTABILITY AND SHEER IN
PLACE WE COULD START TO SEE THUNDERSTORM INITIATION BY THURSDAY
AFTERNOON IN THE WEST. THE BEST CHANCES WILL HOLD OFF UNTIL THURSDAY
NIGHT WHEN BETTER FORCING WILL BE IN PLACE.
TEMPERATURES SHOULD RETURN TO SEASONAL VALUES IN THE UPPER 80S
TODAY...WITH CONTINUED WARMING THROUGH THURSDAY. THE WARMEST DAY
THIS WEEK WILL LIKELY BE ON THURSDAY WHEN GOOD SOUTHERLY FLOW WILL
SUPPORT TEMPERATURES AT LEAST IN THE MIDDLE 90S. GUIDANCE IS SHOWING
H85 TEMPS AROUND 30C WHICH WITH GOOD MIXING (LITTLE CLOUD COVER) MAY
SUPPORT TEMPS IN THE UPPER 90S/NEAR 100F.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 235 AM MDT TUE AUG 12 2014
NO SIGNIFICANT CHANGES WERE NEEDED IN THE EXTENDED. THE BIGGEST
CHALLENGE WILL CONTINUE TO BE TIMING OF BEST PRECIPITATION CHANCES.
MEDIUM RANGE GUIDANCE SHOWS A WEST/NORTHWESTERLY UPPER FLOW REGIME
WITH PERIODIC SHORTWAVE TROUGHS PASSING THROUGH. ONE WAVE WILL MOVE
EASTWARD THROUGH THE CENTRAL HIGH PLAINS ON FRIDAY BRINGING
SLIGHT/LOW CHANCE POPS TO THE ENTIRE FORECAST AREA. BEYOND
FRIDAY...GFS IS MORE PROGRESSIVE THAN ECMWF AND GFS ENSEMBLE SPREAD
GROWS. GIVEN DIFFERENCES IN THE MODELS TYPICAL OF THIS TYPE PATTERN
WITH TRANSIENT WEAK SHORTWAVES DID NOT TRY TO SEPARATE OUT BEST
CHANCES AND ACCEPTED THE MEDIUM RANGE CONSENSUS BLEND FOR POPS THIS
WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE SLIGHTLY ABOVE
NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1046 AM MDT TUE AUG 12 2014
VFR CONDIITONS WILL CONTINUE AT KGLD AND KMCK FOR THE NEXT 24
HOURS. A WEAK SHORTWAVE PROGGED TO MOVE ACROSS THE AREA OVERNIGHT
WILL HAVE SOME MID LEVEL CLOUDS ASSOCIATED WITH IT BUT NO
PRECIPITATION. WINDS WILL BE LIGHT FROM THE SOUTHEAST IN RESPONSE
TO RETREATING HIGH PRESSURE AND A SURFACE TROUGH IN EASTERN COLORADO.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
521 AM MDT TUE AUG 12 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 235 AM MDT TUE AUG 12 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW HIGHLY AMPLIFIED
RIDGE CENTERED OVER THE CENTRAL ROCKIES EXTENDING WELL INTO THE
CANADIAN ROCKIES. THE EASTERN EXTENT OF THIS RIDGE HAS SHIFTED OVER
OUR CWA...WITH THE MAIN STORM TRACK NOW WELL EAST. MONSOONAL PLUME
IS ALSO ORIENTATED MORE OVER THE GREAT BASIN THAT CENTRAL ROCKIES
WITH LITTLE IN THE WAY OF UPSTREAM ACTIVITY OVER THE NORTHERN PLAINS.
AT THE SURFACE HIGH PRESSURE REMAINS IN PLACE THE CENTRAL AND HIGH
PLAINS.
WITH H5 RIDGE NOW HOLDING MUCH MORE INFLUENCE ON WX OVER OUR
CWA...DRY CONDITIONS SHOULD CONTINUE THROUGH AT LEAST WEDNESDAY
AFTERNOON. GUIDANCE HAS SHIFTED TRACK OF A WEAK SHORTWAVE WEDNESDAY
NIGHT TOWARDS THE NORTHERN PLAINS...WITH EVEN THE SOUTHERNMOST
REFLECTION OF THIS BARELY INFLUENCING SW NEBRASKA. WITH THE PRECIP
SIGNAL SHIFTED NORTH AND A VERY DRY AIR MASS IN PLACE (ON ALL
AVAILABLE GUIDANCE) I REMOVED THUNDERSTORM MENTION FROM WEDNESDAY
NIGHT. BY THURSDAY A STRONGER SHORTWAVE WILL BEGIN TO BREAKDOWN THE
WESTERN PART OF THE RIDGE ALLOWING BETTER FORCING TO MOVE TOWARDS
THE PLAINS...AND WITH AT LEAST MODERATE INSTABILITY AND SHEER IN
PLACE WE COULD START TO SEE THUNDERSTORM INITIATION BY THURSDAY
AFTERNOON IN THE WEST. THE BEST CHANCES WILL HOLD OFF UNTIL THURSDAY
NIGHT WHEN BETTER FORCING WILL BE IN PLACE.
TEMPERATURES SHOULD RETURN TO SEASONAL VALUES IN THE UPPER 80S
TODAY...WITH CONTINUED WARMING THROUGH THURSDAY. THE WARMEST DAY
THIS WEEK WILL LIKELY BE ON THURSDAY WHEN GOOD SOUTHERLY FLOW WILL
SUPPORT TEMPERATURES AT LEAST IN THE MIDDLE 90S. GUIDANCE IS SHOWING
H85 TEMPS AROUND 30C WHICH WITH GOOD MIXING (LITTLE CLOUD COVER) MAY
SUPPORT TEMPS IN THE UPPER 90S/NEAR 100F.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 235 AM MDT TUE AUG 12 2014
NO SIGNIFICANT CHANGES WERE NEEDED IN THE EXTENDED. THE BIGGEST
CHALLENGE WILL CONTINUE TO BE TIMING OF BEST PRECIPITATION CHANCES.
MEDIUM RANGE GUIDANCE SHOWS A WEST/NORTHWESTERLY UPPER FLOW REGIME
WITH PERIODIC SHORTWAVE TROUGHS PASSING THROUGH. ONE WAVE WILL MOVE
EASTWARD THROUGH THE CENTRAL HIGH PLAINS ON FRIDAY BRINGING
SLIGHT/LOW CHANCE POPS TO THE ENTIRE FORECAST AREA. BEYOND
FRIDAY...GFS IS MORE PROGRESSIVE THAN ECMWF AND GFS ENSEMBLE SPREAD
GROWS. GIVEN DIFFERENCES IN THE MODELS TYPICAL OF THIS TYPE PATTERN
WITH TRANSIENT WEAK SHORTWAVES DID NOT TRY TO SEPARATE OUT BEST
CHANCES AND ACCEPTED THE MEDIUM RANGE CONSENSUS BLEND FOR POPS THIS
WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE SLIGHTLY ABOVE
NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 518 AM MDT TUE AUG 12 2014
HIGH PRESSURE AT THE SURFACE AND ALOFT WILL RESULT IN PREVAILING VFR
CONDITIONS AND LIGHT SOUTHEAST WINDS 11 KT OR LESS THROUGH THE TAF
PERIOD AT BOTH KGLD AND KMCK TERMINALS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
237 AM MDT TUE AUG 12 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 235 AM MDT TUE AUG 12 2014
EARLY MORNING WV IMAGERY AND RAP H5 ANALYSIS SHOW HIGHLY AMPLIFIED
RIDGE CENTERED OVER THE CENTRAL ROCKIES EXTENDING WELL INTO THE
CANADIAN ROCKIES. THE EASTERN EXTENT OF THIS RIDGE HAS SHIFTED OVER
OUR CWA...WITH THE MAIN STORM TRACK NOW WELL EAST. MONSOONAL PLUME
IS ALSO ORIENTATED MORE OVER THE GREAT BASIN THAT CENTRAL ROCKIES
WITH LITTLE IN THE WAY OF UPSTREAM ACTIVITY OVER THE NORTHERN PLAINS.
AT THE SURFACE HIGH PRESSURE REMAINS IN PLACE THE CENTRAL AND HIGH
PLAINS.
WITH H5 RIDGE NOW HOLDING MUCH MORE INFLUENCE ON WX OVER OUR
CWA...DRY CONDITIONS SHOULD CONTINUE THROUGH AT LEAST WEDNESDAY
AFTERNOON. GUIDANCE HAS SHIFTED TRACK OF A WEAK SHORTWAVE WEDNESDAY
NIGHT TOWARDS THE NORTHERN PLAINS...WITH EVEN THE SOUTHERNMOST
REFLECTION OF THIS BARELY INFLUENCING SW NEBRASKA. WITH THE PRECIP
SIGNAL SHIFTED NORTH AND A VERY DRY AIR MASS IN PLACE (ON ALL
AVAILABLE GUIDANCE) I REMOVED THUNDERSTORM MENTION FROM WEDNESDAY
NIGHT. BY THURSDAY A STRONGER SHORTWAVE WILL BEGIN TO BREAKDOWN THE
WESTERN PART OF THE RIDGE ALLOWING BETTER FORCING TO MOVE TOWARDS
THE PLAINS...AND WITH AT LEAST MODERATE INSTABILITY AND SHEER IN
PLACE WE COULD START TO SEE THUNDERSTORM INITIATION BY THURSDAY
AFTERNOON IN THE WEST. THE BEST CHANCES WILL HOLD OFF UNTIL THURSDAY
NIGHT WHEN BETTER FORCING WILL BE IN PLACE.
TEMPERATURES SHOULD RETURN TO SEASONAL VALUES IN THE UPPER 80S
TODAY...WITH CONTINUED WARMING THROUGH THURSDAY. THE WARMEST DAY
THIS WEEK WILL LIKELY BE ON THURSDAY WHEN GOOD SOUTHERLY FLOW WILL
SUPPORT TEMPERATURES AT LEAST IN THE MIDDLE 90S. GUIDANCE IS SHOWING
H85 TEMPS AROUND 30C WHICH WITH GOOD MIXING (LITTLE CLOUD COVER) MAY
SUPPORT TEMPS IN THE UPPER 90S/NEAR 100F.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 235 AM MDT TUE AUG 12 2014
NO SIGNIFICANT CHANGES WERE NEEDED IN THE EXTENDED. THE BIGGEST
CHALLENGE WILL CONTINUE TO BE TIMING OF BEST PRECIPITATION CHANCES.
MEDIUM RANGE GUIDANCE SHOWS A WEST/NORTHWESTERLY UPPER FLOW REGIME
WITH PERIODIC SHORTWAVE TROUGHS PASSING THROUGH. ONE WAVE WILL MOVE
EASTWARD THROUGH THE CENTRAL HIGH PLAINS ON FRIDAY BRINGING
SLIGHT/LOW CHANCE POPS TO THE ENTIRE FORECAST AREA. BEYOND
FRIDAY...GFS IS MORE PROGRESSIVE THAN ECMWF AND GFS ENSEMBLE SPREAD
GROWS. GIVEN DIFFERENCES IN THE MODELS TYPICAL OF THIS TYPE PATTERN
WITH TRANSIENT WEAK SHORTWAVES DID NOT TRY TO SEPARATE OUT BEST
CHANCES AND ACCEPTED THE MEDIUM RANGE CONSENSUS BLEND FOR POPS THIS
WEEKEND INTO EARLY NEXT WEEK. TEMPERATURES SHOULD BE SLIGHTLY ABOVE
NORMAL THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 951 PM MDT MON AUG 11 2014
VFR CONDITIONS WITH LIGHT WINDS ARE TO CONTINUE FOR THE NEXT 24
HOURS. LEE TROUGH DEVELOPMENT OVER COLORADO WILL LEAD TO A WIND
SHIFT OVERNIGHT AT KMCK. WINDS HAVE ALREADY SHIFTED AROUND AT
KGLD. A FEW DAYTIME CUMULUS ARE POSSIBLE BUT FORECAST SOUNDINGS
INDICATE A DRIER AIR MASS IN PLACE COMPARED TO RECENT DAYS SO OPTED
TO LEAVE OUT A CUMULUS MENTION. NO FOG/STRATUS IS ANTICIPATED THIS
MORNING AS THE BOUNDARY LAYER IS DRIER THAN RECENT MORNINGS AND
TEMPERATURES SHOULD NOT COOL AS MUCH WITH WINDS REMAINING AROUND
6-8 KTS OVERNIGHT.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BRB
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
103 AM EDT Tue Aug 12 2014
...Updated Aviation Discussion...
...Forecast Update...
Issued at 945 PM EDT Mon Aug 11 2014
Have one more significant cell in the middle of the forecast area,
which developed along a theta-e ridge and just ahead of weak PV
anomaly. May yet see a few more spots develop east of the I-65
corridor the next couple of hours, but coverage will be limited by
loss of heating. Latest RUC bumps ahead the timing of some showers
moving in for daybreak tomorrow so have added this into the forecast
as well as put in patchy fog, given weak surface flow and the rains
that fell today.
Issued at 730 PM EDT Mon Aug 11 2014
Cold front is right along the Ohio River this hour and forecast to
continue sagging slowly south. Still expect a secondary front to
move through the region Tuesday, so cannot rule out additional
showers toward daybreak over the north. Till then, we still have
banded precipitation to deal with, torrential at times. Most cells
have been progressive today, but over the last hour some training of
storms has occurred over parts of the Bluegrass. With the loss of
heating, expect our convection to weaken significantly. Updated the
forecast to bring grids closer to current observations.
.SHORT TERM (Now through Tuesday Night)...
Issued at 257 PM EDT Mon Aug 11 2014
We will have one more day of unsettled weather before drier and
cooler conditions prevail for the second half of the week. For
tonight through tomorrow an upper level trough will continue to dig
into the Great Lakes and Ohio Valley region. This trough will then
start to shift off to the east Tuesday night. A vortmax is moving
across the region now and another will swing through tomorrow
afternoon. At the surface low pressure currently across northern
IN/OH will drag a weak cold front through tonight.
Scattered to numerous showers and thunderstorms will continue across
the forecast area this afternoon and early evening. With PWAT values
hovering near 2" these storms will be very heavy rain producers.
Training of storms will potentially cause ponding of water or
localized flooding. In addition, a few strong wind gusts could be
realized from the strongest storms.
Storms will decrease tonight near sunset and much of the area should
go dry overnight as the front moves through. A few showers could
linger in the east, however. For tomorrow, scattered showers and
storms will again develop as the reinforcing vortmax swings through.
Moisture will not be as high tomorrow, so rainfall intensity should
not be as high as today.
Highs tomorrow look to be a bit cooler than today in the upper 70s
to lower 80s. Lows tonight will be in the mid to upper 60s. As drier
air filters in tomorrow night, lows will drop much lower, bottoming
out in the upper 50s to lower 60s.
.LONG TERM (Wednesday through Monday)...
Issued at 250 PM EDT Mon Aug 11 2014
We`ll begin the long term period with a dry, relatively cool period
as an upper level trough sits over the region with high pressure at
the surface. Expect partly to mostly sunny skies Wed-Sat with high
temps in the upper 70s to mid 80s. Wed looks to be the coolest day
in the long term period with highs in the upper 70s to around 80
across the area. We will start to see some weak ridging work in
from the west by Sat allowing temps to warm into the mid 80s over
most locations. Low temps will be in the upper 50s to lower 60s.
In addition to unseasonably cool temps, humidity levels will be much
lower than the beginning of the week as dewpts drop back into the
50s.
As we head into the beginning of next week, a shortwave upper level
trough will approach the region. Ahead of the trough southerly flow
will usher in moist, unstable air and eventually rain chances.
Models have slowed down on the 12Z runs today delaying rain until at
least Sun night or Mon. Thus, will eliminate POPs for Sun and stick
to low POPs (20-30%) for Sun night-Mon. Temps will climb back into
the upper 80s and possibly approaching 90 by the beginning of next
week.
&&
.AVIATION (06Z TAF Update)...
Issued at 100 AM EDT Tue Aug 12 2014
Main challenge in this TAF set is the overnight fog potential.
Plenty of low-level moisture in place due to recent rains,
especially at BWG and LEX. Main factor weighing against fog
formation will be winds staying up out of the W-SW around 5-6 kt.
LEX has already seen a low stratus ceiling develop, and while there
may be just enough wind to keep this up as stratus, still expect IFR
for much of the night, be it ceiling or vis. Will include a TEMPO
for vis restrictions toward morning, but most likely keep the LIFR
ceilings anyway unless changes are evident by issuance time. BWG
should roll MVFR most of the night, but given its propensity for
fog, at least a TEMPO for IFR vis seems prudent. SDF should stay
above fuel-alternate thresholds.
Fog/stratus should mix out fairly well as WNW winds pick up, but it
could take most of the morning for this process to occur. Expect to
go VFR around midday, with LEX being the last to improve. Cold pool
aloft will support a decent cu field, and even a ceiling at SDF/LEX.
Can`t rule out an isolated shower or T-storm, but chances are too
low to include. Westerly wind gusts in the afternoon will push 20
kt, then winds diminish and skies clear after sunset.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........RJS
Short Term.....EER
Long Term......AMS
Aviation.......RAS
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1245 PM CDT TUE AUG 12 2014
.AVIATION...
FOR THE 12/18Z TAFS...VFR CONDITIONS TO DOMINATE THE TAF PERIOD
WITH SOMEWHAT COOLER AND DRIER AIR MASS COMPARED TO PREVIOUS DAYS.
FRONT RESPONSIBLE FOR THIS CHANGE HAS SLIPPED JUST SOUTH OF OUR
REGION BUT STILL MAY HELP GENERATE SOME SPOTTY CONVECTION NEAR OR
JUST SOUTH OF THE LFK TERMINAL THIS AFTERNOON...HAVE NOT INCLUDED
VCTS AT LFK FOR THIS ISSUANCE DUE TO LOW CONFIDENCE ANYTHING WILL
DEVELOP THAT FAR NORTH. OTHERWISE...EXPECT LIGHT NLY WINDS TO
PREVAIL THIS AFTERNOON AND BECOMING NEAR CALM OVERNIGHT WITH SOME
PATCHY FOG POSSIBLE AT ELD/MLU. CU FIELD WILL REDEVELOP LATE IN
THE TAF PERIOD SIMILAR TO THIS AFTERNOON WITH HEIGHTS BETWEEN
4-5KFT. WINDS WILL SHIFT MORE E/NE BY 13/15Z INCREASE TO 5-10 KTS.
/19/
&&
.PREV DISCUSSION... /ISSUED 1115 AM CDT TUE AUG 12 2014/
DISCUSSION...
THE 15Z SFC ANALYSIS INDICATES THAT THE WEAK COOL FRONT IS A
LITTLE ILL-DEFINED LATE THIS MORNING...AND EXTENDS FROM DEEP E TX
INTO NCNTRL LA AND CNTRL MS. HOWEVER...THE DRIER AIR DOES LAG THE
FRONT FARTHER N ACROSS EXTREME NE TX/SW AR...BUT SHOULD GRADUALLY
SEEP S ACROSS THE REMAINDER OF THE AREA THIS AFTERNOON. HAVE
ALREADY SEEN MID AND UPPER LEVEL DRY AIR INFILTRATE S ACROSS AT
LEAST THE NRN HALF OF THE AREA...EVIDENCED FROM THE 12Z KSHV
RAOB...WITH PW/S STILL NEAR OR IN EXCESS OF 2 INCHES FARTHER S
WITHIN THE MOIST SECTOR /PER THE 12Z KLCH RAOB/. ALREADY SEEING
MODERATE MLCAPES DEVELOPING NOW NEAR AND S OF I-20 ACROSS E TX/N
LA ALONG/JUST AHEAD OF THE DRIER SFC AIR...WITH EVEN A FEW
TOWERING CU ON VISIBLE SATELLITE OVER PORTIONS OF ECNTRL TX WHERE
TEMPS ARE NEARING 90 DEGREES ATTM. GIVEN THE AVAILABLE MOISTURE
STILL AVAILABLE THIS AFTERNOON...AND STRONG HEATING...CAN/T RULE
OUT ISOLATED CONVECTION DEVELOPING BY EARLY AFTERNOON OVER DEEP E
TX/NCNTRL LA S OF I-20 AS INDICATED FROM THE LATEST HRRR RUN AND
THE 12Z WRF.
HAVE ADDED SLIGHT CHANCE POPS FARTHER W ACROSS THE REMAINDER OF
NCNTRL LA/DEEP E TX IN THE ZONE UPDATE...WITH ANY CONVECTION
DIMINISHING OVER THE AREAS BY LATE AFTERNOON AS THE DRIER AIR
CONTINUES TO FILTER S. THE 12Z WRF REMAINS CONSISTENT AND BEST IN
HANDLING THE CURRENT DEWPOINTS/DRY AIR ADVECTION...WITH THE ERN
MOST ZONES A LITTLE LATER WITH THE DRY AIR ARRIVING GIVEN THE
WEAKER PRESSURE GRADIENT. TEMPS ALONG/S OF THE I-20 CORRIDOR HAVE
WARMED QUICKLY THIS MORNING...WITH 16Z TEMPS NOW NEARING 90
DEGREES. HAVE BUMPED UP MAX TEMPS A COUPLE DEGREES THIS AFTERNOON
AS READINGS SHOULD LEVEL OFF WITH THE ARRIVAL OF THE DRIER AIR.
OTHERWISE...THE REMAINDER OF THE FORECAST IS ON TRACK.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 92 67 90 67 91 / 10 0 10 10 10
MLU 91 66 88 64 89 / 10 0 10 10 10
DEQ 88 61 88 62 88 / 0 0 10 10 10
TXK 89 64 86 64 88 / 0 0 10 10 10
ELD 89 63 88 62 88 / 0 0 10 10 10
TYR 95 65 89 67 91 / 10 0 10 10 10
GGG 93 65 89 65 91 / 10 0 10 10 10
LFK 95 68 93 69 95 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1115 AM CDT TUE AUG 12 2014
.DISCUSSION...
THE 15Z SFC ANALYSIS INDICATES THAT THE WEAK COOL FRONT IS A
LITTLE ILL-DEFINED LATE THIS MORNING...AND EXTENDS FROM DEEP E TX
INTO NCNTRL LA AND CNTRL MS. HOWEVER...THE DRIER AIR DOES LAG THE
FRONT FARTHER N ACROSS EXTREME NE TX/SW AR...BUT SHOULD GRADUALLY
SEEP S ACROSS THE REMAINDER OF THE AREA THIS AFTERNOON. HAVE
ALREADY SEEN MID AND UPPER LEVEL DRY AIR INFILTRATE S ACROSS AT
LEAST THE NRN HALF OF THE AREA...EVIDENCED FROM THE 12Z KSHV
RAOB...WITH PW/S STILL NEAR OR IN EXCESS OF 2 INCHES FARTHER S
WITHIN THE MOIST SECTOR /PER THE 12Z KLCH RAOB/. ALREADY SEEING
MODERATE MLCAPES DEVELOPING NOW NEAR AND S OF I-20 ACROSS E TX/N
LA ALONG/JUST AHEAD OF THE DRIER SFC AIR...WITH EVEN A FEW
TOWERING CU ON VISIBLE SATELLITE OVER PORTIONS OF ECNTRL TX WHERE
TEMPS ARE NEARING 90 DEGREES ATTM. GIVEN THE AVAILABLE MOISTURE
STILL AVAILABLE THIS AFTERNOON...AND STRONG HEATING...CAN/T RULE
OUT ISOLATED CONVECTION DEVELOPING BY EARLY AFTERNOON OVER DEEP E
TX/NCNTRL LA S OF I-20 AS INDICATED FROM THE LATEST HRRR RUN AND
THE 12Z WRF.
HAVE ADDED SLIGHT CHANCE POPS FARTHER W ACROSS THE REMAINDER OF
NCNTRL LA/DEEP E TX IN THE ZONE UPDATE...WITH ANY CONVECTION
DIMINISHING OVER THE AREAS BY LATE AFTERNOON AS THE DRIER AIR
CONTINUES TO FILTER S. THE 12Z WRF REMAINS CONSISTENT AND BEST IN
HANDLING THE CURRENT DEWPOINTS/DRY AIR ADVECTION...WITH THE ERN
MOST ZONES A LITTLE LATER WITH THE DRY AIR ARRIVING GIVEN THE
WEAKER PRESSURE GRADIENT. TEMPS ALONG/S OF THE I-20 CORRIDOR HAVE
WARMED QUICKLY THIS MORNING...WITH 16Z TEMPS NOW NEARING 90
DEGREES. HAVE BUMPED UP MAX TEMPS A COUPLE DEGREES THIS AFTERNOON
AS READINGS SHOULD LEVEL OFF WITH THE ARRIVAL OF THE DRIER AIR.
OTHERWISE...THE REMAINDER OF THE FORECAST IS ON TRACK.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 92 67 90 67 91 / 10 0 10 10 10
MLU 91 66 88 64 89 / 10 0 10 10 10
DEQ 88 61 88 62 88 / 0 0 10 10 10
TXK 89 64 86 64 88 / 0 0 10 10 10
ELD 89 63 88 62 88 / 0 0 10 10 10
TYR 95 65 89 67 91 / 10 0 10 10 10
GGG 93 65 89 65 91 / 10 0 10 10 10
LFK 95 68 93 69 95 / 20 10 10 10 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
15
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
737 PM EDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 436 PM EDT WED AUG 13 2014
THU NIGHT...WITH THE SFC RIDGE OVER THE AREA...EXPECT GOOD
RADIATIONAL COOLING CONDITIONS UNTIL LATE OVER THE WEST WHEN
MOISTURE BEGINS TO INCREASE. THE LOWER MINS...INTO THE LOWER 40S
INLAND...SHOULD PREVAIL ACROSS THE EAST WHERE PWAT VALUES REMAIN
BELOW 0.5 INCH.
FRI...WSW LOW LEVEL FLOW AND MOISTURE ADVECTION INCREASE AS THE HIGH
SHIFTS TOWARD THE OHIO VALLEY. EVEN THROUGH MLCAPE VALUES MAY CLIMB
INTO THE 400-800 J/KG RANGE AND PWAT RISES TO 1.5 INCHES OVER THE
WEST...THE MODELS SUGGEST THAT THE MAIN FORCING FOR ANY SHRA/TSRA WILL
REMAIN TO THE WEST AS A SHRTWV MOVES FROM SE FROM THE DAKOTAS.
SLIGHT OR LOWER END CHANCE POPS WERE STILL INCLUDED OVER THE WEST
GIVEN THE INSTABILITY AND POTENTIAL FOR EITHER A WEAK SHRTWV OR BAND
OF 300-310K ISENTROPIC LIFT TO SET OFF SOME SCT/ISOLD SHRA/TSRA.
FRI NIGHT INTO SAT...EXPECT A GREATER CHANCE FOR PCPN AS MODELS WERE
IN GOOD AGREEMENT IN BRINGING A SHORTWAVE TROUGH WITH MODERATE
700-300 MB QVECTOR CONV AND AN ASSOCIATED COLD FRONT THROUGH THE NRN
GREAT LAKES. BY SAT AFTERNOON IN THE WAKE OF THE FRONT...PCPN
CHANCES SHOULD DIMINISH ACROSS THE NORTH WITH COOLER MORE STABLE AIR
MOVING IN ON LOW LEVEL NRLY FLOW.
SUN-WED...MAINLY DRY WEATHER THROUGH MON IS EXPECTED WITH MID LEVEL
RIDGING AND A SFC RIDGE DOMINATING. THE GFS/GEM/ECMWF SUGGEST THAT A
SLOW MOVING SHRTWV AND SFC TROUGH WILL MOVE INTO THE WRN LAKES FROM
TUE INTO WED. ALTHOUGH CONFIDENCE IS LOW WITH THE POSITION/STRENGTH
OF THIS FEATURE...MDLS CONSENSUS OF INCREASING POPS AND TSRA
POTENTIAL SEEMS REASONABLE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 737 PM EDT WED AUG 13 2014
A DRY AIR MASS ASSOCIATED WITH HIGH PRES BUILDING OVER THE UPPER
GREAT LAKES WILL RESULT IN VFR CONDITIONS PREVAILING AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 331 PM EDT WED AUG 13 2014
UNDER A SHARP PRES GRADIENT BETWEEN HI PRES SINKING SOUTH THRU FAR
WESTERN ONTARIO AND SLOW MOVING LO PRES IN WESTERN QUEBEC...EXPECT N
TO NW WINDS AS HI AS 20-25 KTS OVER THE E HALF OF LAKE SUPERIOR THRU
THU. AS THE ONTARIO HI MOVES OVER THE UPPER LAKES LATER ON THU...
EXPECT WINDS TO DIMINISH UNDER 15 KTS BY FRI. THESE LIGHTER WINDS
WILL PERSIST INTO SAT...BUT THE SHARPENING PRES GRADIENT BEHIND A
COLD FRONTAL PASSAGE WILL CAUSE N-NE WINDS TO INCREASE UP TO 20 KTS
ON SAT NIGHT INTO SUN. AS THE HI PRES TRAILING THE FRONT SLIDES TO
THE SE EARLY NEXT WEEK...WINDS WILL SHIFT TO THE SSE UP TO 20 KTS ON
MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
403 PM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 402 PM EDT TUE AUG 12 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW JUST
EAST OF THE SAULT RESULTING IN NNW FLOW FROM NW ONTARIO THROUGH THE
WRN GREAT LAKES. THE BACK EDGE OF THE CLOUDS ASSOCIATED WITH THE LOW
HAD MOVED TO NEAR SAW-IMT LEAVING CLEAR SKIES OVER THE WEST AND
THICK CLOUDS WITH A FEW SPRINKLES OVER THE ERN CWA. AN UPSTREAM
CLIPPER SHORTWAVE TROUGH AND COLD FRONT THAT SUPPORTED A FEW LIGHT
SHOWERS OR SPRINKLES WAS MOVING THROUGH NW ONTARIO.
TONIGHT...EXPECT THAT SOME LIGHT SHOWERS OR SPRINKLES ASSOCIATED
WITH THE NW ONTARIO SHRTWV MAY MOVE INTO WRN LAKE SUPERIOR AND
POSSIBLY WRN UPPER MI. HOWEVER...SINCE FORCING WITH THE SHRTWV IS
WEAK AND LITTLE MOISTURE/INSTABILITY IS AVAILABLE DURING THE
OVERNIGHT...NO PCPN MENTION WAS ADDED TO THE FCST.
WED...BEHIND THE COLD FRONT...NNW WINDS WILL AGAIN INCREASE WHICH
COULD SUPPORT AN INCREASE IN UPSLOPE CLOUDS OVER N CNTRL UPPER MI.
TEMPS WILL REMAIN BELOW NORMAL WITH HIGHS FROM THE MID 60S NORTH TO
THE LOWER 70S SOUTH. SWIM RISK WILL AGAIN BE HIGH AS 3 TO 5 FOOT
WAVES ARE EXPECTED INTO MARQUETTE AND ALGER COUNTIES BY AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM EDT TUE AUG 12 2014
MAIN FCST CONCERNS IN THE MEDIUM/LONGER RANGE WL FOCUS ON EXPECTED
BLO NORMAL TEMPS FOR WED THRU THU...WHEN DRY CNDN HI PRES IS FCST TO
DOMINATE UNDER A CONFLUENT NNW FLOW ALF. FOCUS FOR FRI/SAT WL SHIFT
TO PCPN CHCS ASSOCIATED WITH THE INTERACTION BTWN RETURNING MSTR IN
THE LLVL SW FLOW ARND THE DEPARTING HI TO THE SE AND SHRTWVS
TRACKING THRU THE GREAT LKS WITHIN THE NW FLOW FARTHER ALF. ALTHOUGH
ABV NORMAL TEMPS MAY RETURN FOR FRI INTO SAT...NO SUMMER-LIKE WARMTH
IS EXPECTED DURING THE NEXT WEEK.
WED NGT/THU...HI PRES AND DRY AIRMASS WITH PWAT BTWN 0.25-0.50 INCH
/AS LITTLE AS ABOUT 25 PCT OF NORMAL/ WL PASS OVER UPR MI UNDER NNW
FLOW ALF TO THE W OF SLOW MOVING CLOSED LO NEAR THE ONTARIO/QUEBEC
BORDER. UNDER MOCLR SKIES...EXPECT THE LOWEST MIN TEMPS ON WED NGT
OVER THE INTERIOR W...WHERE WINDS WL BE LIGHTEST FOR A LONGER TIME
AND WHERE THE RDG AXIS IS FCST TO BE AT 12Z THU. NOT OUT OF THE
QUESTION THERE COULD BE SOME 30S AT THE COLDER LOCATIONS IN THIS
AREA. WITH H85 TEMPS FCST TO PEAK BTWN 8C OVER THE E AND 12C OVER
THE W AT 00Z FRI...EXPECT HI TEMPS TO REACH THE 70S OVER THE
INTERIOR W/SCENTRAL BUT HOLD IN THE 60S OVER MUCH OF THE E WITH A
STEADY NNW SFC-H925 FLOW OFF LK SUP.
THU NGT...SFC HI PRES IS FCST TO SINK OVER INDIANA BY 12Z FRI...
WITH SFC RDG AXIS EXTENDING N THRU ERN UPR MI. THE LOWEST TEMPS WL
BE OVER THE INTERIOR E...WHERE PWAT UNDER 0.5 INCH/MOCLR SKIES/
LIGHTER WINDS UNDER THE RDG AXIS WL LINGER THRU THE NGT. SOME CLDS
ASSOCIATED WITH PWAT RISING AOA 1 INCH AT IWD BY 12Z FRI IN SW
RETURN FLOW ARND THE SFC HI WL LIMIT THE DIURNAL TEMP FALL IN THAT
AREA.
FRI THRU SAT...UPR MI IS FCST TO REMAIN UNDER NW FLOW ALF BTWN DEEP
UPR TROF OVER QUEBEC AND RDG EXTENDING THRU THE PLAINS. THE
INTERACTION BTWN SHRTWVS DIGGING SEWD THRU THIS UPR FLOW AND MORE
MSTR ADVECTED INTO THE AREA IN LLVL WSW FLOW TO THE NW OF SFC HI
FCST TO SINK INTO THE SRN MID ATLANTIC STATES WL BE THE MAIN FCST
CONCERN DURING THIS PERIOD. A GOOD NUMBER OF THE MEDIUM RANGE MODELS
GENERATE PCPN AS EARLY AS FRI...WHEN THE HIER PWAT ARND 1.5 INCHES
IS FCST TO RETURN. CONSIDERING THE RATHER DRAMATIC INCRS IN PWAT/
SOME ISENTROPIC ASCENT...ADDED CHC POPS FOR THE FRI FCST DESPITE AN
ABSENCE OF SGNFT DEEP LYR QVECTOR CNVGC WELL SE OF STRONGER SHRTWV
SLIDING THRU NW ONTARIO. A BETTER CHC OF SHOWERS/A FEW TS WL ARRIVE
ON FRI NGT AND SAT...WHEN MODEL CONSENSUS IS TRENDING TOWARD THE
PASSAGE OF THE DIGGING ONTARIO SHRTWV/ATTENDANT SFC COLD FNT AND AN
AREA OF SHARPER DEEP LYR QVECTOR CNVGC. ALTHOUGH THE GREATER CLD
COVER WL TEND TO LIMIT THE DIURNAL DIURNAL VARIATION DURING THIS
TIME...EXPECT TEMPS TO RISE ABV NORMAL DURING THIS PERIOD AS THE WSW
FLOW BRINGS A RETURN OF H85 TEMPS AS HI AS 16-17C BY SAT.
SUN THRU TUE...MOST OF THE LONGER RANGE MODELS INDICATE SFC HI PRES
WL BLD INTO THE UPR LKS ON SUN FOLLOWING SHRTWV/COLD FROPA PASSAGE
BY LATE SAT...SO CONSENSUS FCST WL SHOW A DRYING TREND AND A RETURN
OF A BIT COOLER AIR. PCPN CHCS WL RETURN EARLY NEXT WEEK AS THE UPR
FLOW IS FCST TO BECOME MORE ZONAL AND ALLOW THE PASSAGE OF ANOTHER
SHRTWV.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 134 PM EDT TUE AUG 12 2014
HIGH PRESSURE AND DRY AIR MOVING INTO THE WESTERN U.P. WILL BRING
VFR CONDITIONS TO BOTH KIWD THROUGH THE FCST PERIOD. MVFR CONDITIONS
IN COOL MOIST UPSLOPE FLOW OFF OF LAKE SUPERIOR WILL GIVE WAY TO VFR
CIGS BY LATE AFTERNOON AS DRY AIR SLOWLY EDGES INTO CNTRL UPPER MI.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EDT TUE AUG 12 2014
NORTH WINDS GUSTING TO MORE THAN 25 KTS ACROSS THE EASTERN PART OF
THE LAKE WILL DIMINISH THIS EVENING AS THE PRES GRADIENT WEAKENS. A
REINFORCING COLD FRONT WILL PUSH ACROSS THE LAKE ON WEDNESDAY
ALLOWING NORTHWESTERLY WIND GUSTS OF UP TO 25 KTS WEDNESDAY
AFTERNOON. WINDS SHOULD DIMINISH BY LATE WEDNESDAY AND THEN REMAIN
BELOW 15 KTS INTO THE UPCOMING WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ005-
006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KC
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1251 PM EDT TUE AUG 12 2014
.AVIATION...
//DISCUSSION...
BLOSSOMING AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS AS WE ENTER
PEAK HEATING OF THE DAY AND UPPER LEVEL TROUGH AXIS MOVES OVERHEAD.
MAJORITY OF ACTIVITY SHOULD BE EXITING/DIMINISHING AROUND 00Z.
SURFACE NORTHWEST WINDS AROUND 10 KNOTS WILL ATTEMPT TO USHER IN
DRIER AIR...BUT IT WILL TAKE MOST/ALL OF THE NIGHT-TIME HOURS TO
SCOUR OUT THE LOW CLOUDS (HIGH IFR/LOW MVFR). ANY RESIDUAL LOW
CLOUDS WEDNESDAY MORNING SHOULD MIX OUT AND LIFT.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* MEDIUM CONFIDENCE IN THUNDERSTORM THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 827 AM EDT TUE AUG 12 2014
UPDATE...
PLENTY OF LOW LEVEL MOISTURE LEFTOVER ACROSS SOUTHEAST MICHIGAN AS
SURFACE DEW POINTS HOVER IN THE LOW TO MID 60S...AND UPPER LEVEL
TROUGH/COLD POOL (500 MB TEMPS OF -13 TO -14 C) AND SECONDARY
SURFACE COLD FRONT SWINGING THROUGH TODAY WILL BE SUFFICIENT TO
GENERATE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS...AS THERE
IS ALSO SOLID INSTABILITY WITH SBCAPES IN THE 1000-1500 J/KG
RANGE. 0-6 KM SHEAR REACHES AROUND 20 KNOTS TOWARD THE CANADIAN
BORDER...OTHERWISE SHEAR IS WEAK...AND THUS SEVERE WEATHER IS NOT
EXPECTED. COULD SEE SMALL HAIL AND BRIEF HEAVY RAIN.
PREV DISCUSSION...ISSUED 305 AM EDT TUE AUG 12 2014
SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SF
UPDATE.......SF
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
827 AM EDT TUE AUG 12 2014
.UPDATE...
PLENTY OF LOW LEVEL MOISTURE LEFTOVER ACROSS SOUTHEAST MICHIGAN AS
SURFACE DEW POINTS HOVER IN THE LOW TO MID 60S...AND UPPER LEVEL
TROUGH/COLD POOL (500 MB TEMPS OF -13 TO -14 C) AND SECONDARY
SURFACE COLD FRONT SWINGING THROUGH TODAY WILL BE SUFFICIENT TO
GENERATE NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMS...AS THERE
IS ALSO SOLID INSTABILITY WITH SBCAPES IN THE 1000-1500 J/KG
RANGE. 0-6 KM SHEAR REACHES AROUND 20 KNOTS TOWARD THE CANADIAN
BORDER...OTHERWISE SHEAR IS WEAK...AND THUS SEVERE WEATHER IS NOT
EXPECTED. COULD SEE SMALL HAIL AND BRIEF HEAVY RAIN.
&&
.AVIATION...ISSUED 651 AM EDT TUE AUG 12 2014
//DISCUSSION...
A LOWER STRATUS DECK WILL REMAIN PREVALENT THIS MORNING AS ABUNDANT
LOW LEVEL MOISTURE WORKS IN BEHIND A DEPARTING LOW PRESSURE SYSTEM.
THE EXISTING IFR CEILING HEIGHTS ACROSS THE SOUTHERN TAF SITES WILL
LIFT WITH TIME AS DAYTIME HEATING TAKES A STRONGER HOLD. THE
PASSAGE OF A MID LEVEL TROUGH WILL RESULT IN SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING.
CONFIDENCE REMAINS LOW ENOUGH ON POTENTIAL TIMING...COVERAGE AND
DURATION OF THUNDERSTORMS TO PRECLUDE A SPECIFIC MENTION WITH THE
12Z TAF CYCLE. LINGERING MOISTURE WILL FAVOR ADDITIONAL MVFR
STRATUS DEVELOPMENT THROUGH TONIGHT.
FOR DTW...THE MOIST NEAR SURFACE CONDITIONS WILL TAKE SOME TIME TO
MIX OUT...LEAVING IFR CONDITIONS OVER THE AIRSPACE FOR MUCH OF THE
MORNING PERIOD. MVFR/VFR CEILING INTO THE AFTERNOON AS MIXING TAKES
A BETTER HOLD. SCATTERED SHOWERS TODAY...LOW CONFIDENCE IN POSSIBLE
THUNDERSTORM ACTIVITY.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL TODAY.
&&
.PREV DISCUSSION...ISSUED 305 AM EDT TUE AUG 12 2014
SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SF
AVIATION.....MR
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
651 AM EDT TUE AUG 12 2014
.AVIATION...
//DISCUSSION...
A LOWER STRATUS DECK WILL REMAIN PREVALENT THIS MORNING AS ABUNDANT
LOW LEVEL MOISTURE WORKS IN BEHIND A DEPARTING LOW PRESSURE SYSTEM.
THE EXISTING IFR CEILING HEIGHTS ACROSS THE SOUTHERN TAF SITES WILL
LIFT WITH TIME AS DAYTIME HEATING TAKES A STRONGER HOLD. THE
PASSAGE OF A MID LEVEL TROUGH WILL RESULT IN SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT DURING THE AFTERNOON AND EARLY EVENING.
CONFIDENCE REMAINS LOW ENOUGH ON POTENTIAL TIMING...COVERAGE AND
DURATION OF THUNDERSTORMS TO PRECLUDE A SPECIFIC MENTION WITH THE
12Z TAF CYCLE. LINGERING MOISTURE WILL FAVOR ADDITIONAL MVFR
STRATUS DEVELOPMENT THROUGH TONIGHT.
FOR DTW...THE MOIST NEAR SURFACE CONDITIONS WILL TAKE SOME TIME TO
MIX OUT...LEAVING IFR CONDITIONS OVER THE AIRSPACE FOR MUCH OF THE
MORNING PERIOD. MVFR/VFR CEILING INTO THE AFTERNOON AS MIXING TAKES
A BETTER HOLD. SCATTERED SHOWERS TODAY...LOW CONFIDENCE IN POSSIBLE
THUNDERSTORM ACTIVITY.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TONIGHT.
* LOW CONFIDENCE IN THUNDERSTORM POTENTIAL TODAY.
&&
.PREV DISCUSSION...ISSUED 305 AM EDT TUE AUG 12 2014
SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
438 AM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST. WITH
MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 438 AM EDT TUE AUG 12 2014
WITH THE 500MB TROUGH /OR AT TIMES CUT OFF LOW/ SET UP OVER THE E
THIRD OF ONTARIO AND THROUGH THE LOWER GREAT LAKES...UPPER MI WILL
BE STUCK IN NW FLOW.
WHILE THE MAIN SFC LOW EXITS ALONG THE ONTARIO/QUEBEC BORDER BY 12Z
WEDNESDAY...IT WILL STILL INFLUENCE UPPER MI BY ROTATING A SECONDARY
COLD FRONT/TROUGH OVER THE CWA WEDNESDAY MORNING. WHILE THE BOUNDARY
IS EXPECTED TO BE DRY...WINDS SHOULD SHIFT BACK TO THE N AND BECOME
BREEZY AGAIN THANKS TO THE LARGE CANADIAN HIGH RAPIDLY SINKING INTO
THE AREA. EXPECT THE SFC HIGH TO PUSH ACROSS W AND CENTRAL UPPER MI
WEDNESDAY EVENING. PW VALUES WILL QUICKLY FALL TO AROUND 40 PERCENT
OF NORMAL BY THE END OF THE DAY WEDNESDAY...AND REMAIN NEAR THE SAME
VALUES THROUGH AT LEAST DAYBREAK THURSDAY. COOLED OFF WEDNESDAY
NIGHT/THURSDAY MORNING INTO THE LOW 40S OVER THE INTERIOR W HALF.
THE COOLEST GUIDANCE VALUES ARE SUGGESTION BELOW FREEZING VALUES
OVER THE TYPICAL COOL SPOTS.
LOOK FOR THE 500MB LOW TO SHIFT INTO S QUEBEC THURSDAY
MORNING...WHERE IT WILL REMAIN THROUGH FRIDAY NIGHT. NO QUICK
WARMUPS ARE IN STORE...WITH SLOWLY MODERATING HIGH TEMPERATURES
RISING TO NEAR NORMAL VALUES BY FRIDAY.
BOTH THE ECMWF AND GFS ARE INDICATING A DECENT SHORTWAVE AND SFC LOW
TO SINK IN FROM THE NW CORNER OF ONTARIO FRIDAY NIGHT INTO SATURDAY.
DID NOT MAKE TOO MANY LARGE SCALE CHANGES TO THE ONGOING POPS FOR
FRIDAY /MAINLY AFTERNOON/ THROUGH SATURDAY..ASSISTED BY A SFC LOW
DIPPING ACROSS THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 130 AM EDT TUE AUG 12 2014
MVFR CONDITIONS WILL CONTINUE AT IWD AND CMX OVERNIGHT BEFORE DRIER
AIR MOVES IN FOR TUE MORNING AND LEADS TO VFR CONDITIONS THROUGH THE
REST OF THE PERIOD.
RAIN ALONG WITH MOIST NORTHERLY FLOW WILL KEEP LIFR CIGS AT SAW
OVERNIGHT. CYCLONIC UPSLOPE FLOW INTO THE NORTH CENTRAL U.P. WILL
KEEP LOW CIGS AT KSAW INTO TUESDAY AFTERNOON BEFORE DRIER AIR AND
VFR CONDITIONS ARRIVE LATE TUE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
BEACH HAZARDS STATEMENT FROM 8 AM EDT THIS MORNING THROUGH THIS
EVENING FOR MIZ005-006.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...MZ
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
305 AM EDT TUE AUG 12 2014
.SHORT TERM...TODAY AND TONIGHT
HIGH AMPLITUDE MID LEVEL TROUGH NOW SHIFTING ACROSS THE UPPER
MISSISSIPPI VALLEY WILL STEADILY DEEPEN AND EVENTUALLY CLOSE OFF
HEADING INTO TODAY AS IT PIVOTS ACROSS THE LOWER PENINSULA. LEAD
SPOKE OF VORTICITY ANCHORING THE EDGE OF THE MAIN HEIGHT FALL CENTER
CURRENTLY EJECTING ACROSS THE CHICAGO AREA...AND WILL PROVIDE THE
INITIAL WING OF FORCING AS IT TRANSLATES ACROSS MAINLY THE SOUTHERN
HALF OF THE FORECAST AREA EARLY IN THE DAY. THIS MAY PROVE
SUFFICIENT TOWARD SPARKING A FEW SHOWERS...LATEST HI RES GUIDANCE
AND RUC ANALYSIS IN SUPPORT OF A LOW POP MENTION EARLY ON. GREATEST
PROSPECTS FOR PRECIPITATION DEVELOPMENT WILL FOCUS INTO THE
AFTERNOON/EARLY EVENING AS LAPSE RATES STEEPEN CONSIDERABLY THROUGH
BOTH DAYTIME HEATING AND THE PASSAGE OF THE ATTENDANT COLD POOL
/-13C AT 500 MB/. A PERIOD OF GREATER CVA ACCOMPANYING THE MAIN
TROUGH PASSAGE WILL PROVIDE THE BACKGROUND FORCING TO SUPPORT A
SCATTERED COVERAGE OF SHOWERS AND THUNDERSTORMS GIVEN THE
THERMODYNAMIC PROFILE. THE OVERALL TEMPERATURE RECOVERY WILL BE
HINDERED BY LESS FAVORABLE INSOLATION POTENTIAL WITH CLOUD COVER
PROBLEMATIC. HIGHS IN THE LOW AND MIDDLE 70S.
LOW LEVEL COLD AIR ADVECTION TONIGHT AS DEEPER NORTHWEST FLOW
EMERGES ON THE BACKSIDE OF THE EXITING TROUGH. THE BETTER LOW LEVEL
DRYING WILL TAKE MORE TIME TO DEVELOP...NOTING THE SUBSTANTIAL LOW
CLOUD STILL EMANATING ACROSS THE MISSISSIPPI VALLEY THIS MORNING.
THIS POINTS TOWARD SOME LINGERING LOWER STRATUS FOR MUCH OF THE
OVERNIGHT PERIOD...A MORE GRADUALLY CLEARING TREND CLOSER TO
DAYBREAK. LOWS IN THE 50S.
&&
.LONG TERM...
TODAY`S SYSTEM WILL PHASE WITH ENERGY DIVING INTO ONTARIO THIS
MORNING TO PRODUCE A LARGE CLOSED LOW CENTERED OVER WESTERN QUEBEC
BY EARLY THURSDAY. AS A RESULT, DRY NORTHWEST FLOW IS FORECAST TO
DOMINATE OVER THE CENTRAL GREAT LAKES FOR THE REMAINDER OF THE WEEK.
WHILE EMBEDDED IMPULSES WITHIN PREVAILING CYCLONIC FLOW ALOFT WILL
PROPAGATE ACROSS THE AREA BOTH WED AND THURS, DEEP MOISTURE WILL
REMAIN WRAPPED AROUND THE OCCLUDING SURFACE LOW. THIS WILL ELIMINATE
CONCERNS FOR PRECIPITATION AND WILL SHIFT THE FOCUS TOWARD CLOUD
COVER EACH DAY. THE LARGEST CHANGE TO THE INHERITED FORECAST WAS TO
BUMP UP AFTN CLOUD COVER BOTH WED AND THURS GIVEN THE PROGGED
FAVORABLE TIMING OF UPPER WAVES WITH PEAK HEATING AND HIGHER
EXPECTATIONS FOR RESIDENT BOUNDARY LAYER MOISTURE GIVEN THE
COMBINATION OF YESTERDAY`S AND TODAY`S RAINFALL.
H85 TEMPS AROUND 10C COMBINED WITH CLOUDS WILL SUPPORT HIGHS IN MOST
PLACES NO BETTER THAN THE MID 70S ON WEDNESDAY. THE AFOREMENTIONED
PASSING UPPER WAVE WILL ORGANIZE A WEAK BAROCLINIC ZONE THAT WILL
PUSH SOUTH THROUGH THE CWA WEDNESDAY NIGHT. WITH H85 TEMPS TAKING
ANOTHER DIVE TO AROUND 6C THURSDAY, HIGHS WILL TOP OUT IN THE LOW
70S, PERHAPS ONLY REACHING THE UPPER 60S THE EASTERN THUMB AND ALONG
THE GLACIAL RIDGE.
EASTWARD PROGRESSION OF THE UPSTREAM UPPER RIDGE WILL FORCE SURFACE
HIGH PRESSURE TO TRANSLATE EASTWARD AND ULTIMATELY SETTLE JUST SOUTH
OF THE AREA ON THURSDAY NIGHT. EASING OF THE LOCAL PRESSURE GRADIENT
WILL RESULT MORE FAVORABLE RADIATING CONDITIONS. AS A RESULT,
DROPPED FORECAST HIGHS SEVERAL DEGREES INTO THE MID 40S OUTSIDE OF
THE METRO AREA. SUSPECT THAT THERE WILL STILL BE ENOUGH BOUNDARY
LAYER MOISTURE HANGING AROUND TO MAKE FOG A CONSIDERATION FOR
THURSDAY NIGHT, BUT WILL REFRAIN FROM INTRODUCING IT INTO THE
FORECAST AT SUCH AN EARLY STAGE. HIGHS WILL REBOUND INTO THE MID 70S
ON FRIDAY IN RESPONSE TO THE DEPARTURE OF THE THERMAL TROUGH.
&&
.MARINE...
A FRESH NORTHWEST BREEZE WILL GUST TO NEAR GALES ACROSS THE NORTHERN
HALF OF LAKE HURON LATE THIS AFTERNOON THROUGH THE FIRST HALF OF
TONIGHT AS COLDER AIR FILTERS INTO THE REGION. MARGINAL SMALL CRAFT
ADVISORY CONDITIONS WILL THEREFORE BE POSSIBLE LATE TONIGHT INTO
EARLY WEDNESDAY FOR THE EXPOSED NEARSHORE WATERS OF THE THUMB.
SURFACE HIGH PRESSURE WILL REMAIN UPSTREAM OF THE AREA WHICH WILL
PROMOTE A STEADY STATE MODERATE NORTHWEST FLOW THROUGH THURSDAY
NIGHT. GUSTS IN EXCESS OF 20 KNOTS WILL REMAIN COMMON OVER LAKE
HURON DURING THIS TIME. WINDS WILL EASE A BIT ON FRIDAY AS THE
CENTER OF HIGH PRESSURE SETTLES CLOSER TO THE REGION.
&&
.AVIATION...ISSUED 1202 AM EDT TUE AUG 12 2014
//DISCUSSION...
HEAVY RAIN HAS EXITED THE TAF SITES. HOWEVER RESIDUAL LOW LEVEL
MOISTURE HAS LED TO THE FORMATION OF LOW CEILINGS AND RESTRICTIONS
TO VISIBILITY. WIDESPREAD IFR CONDITIONS ARE EXPECTED
OVERNIGHT...WITH POCKETS OF LIFR POSSIBLE. INCREASING SOUTHWEST TO
WESTERLY GRADIENT TUESDAY MORNING AND THE COMMENCEMENT OF THE
DAYLIGHT SHOULD ALLOW CLOUD BASES TO RISE BACK INTO THE MVFR
CATEGORY. WRAP AROUND MOISTURE FROM A DEPARTING LOW PRESSURE SYSTEM
WILL BRING MORE RAIN TO THE TAF SITES LATE TUESDAY MORNING INTO THE
AFTERNOON HOURS...WITH THE BEST CHANCES NORTH OF THE METRO AIRPORTS.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FEET THROUGH TUESDAY.
* LOW CONFIDENCE IN CEILINGS/VSBYS FALLING BELOW 200FT/1/2SM
OVERNIGHT WITH FOG.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...MR
LONG TERM....JVC
MARINE.......JVC
AVIATION.....KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 AM EDT TUE AUG 12 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 410 PM EDT MON AUG 11 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
THE ROCKIES AND A TROUGH FROM HUDSON BAY INTO THE UPPER MS VALLEY.
AT THE SFC...A FRONT EXTENDED FROM SE LAKE SUPERIOR INTO NE WI. A
DEEPENING TROUGH WITH AN 85 KNOT 250 MB JET MOVING THROUGH WRN
WI...AND 800-600 MB FGEN SUPPORTED A LARGE ARA OF PCPN THROUGH WRN
UPPER MI. ANOTHER AREA OF SHOWERS INTO SE AND ERN UPPER MI WAS
ASSOCIATED WITH A WEAK SHRTWV TROUGH INTO NRN LAKE MI.
TONIGHT...EXPECT SHRA COVERAGE TO GRADUALLY INCREASE OVER CNTRL
UPPER MI AS THE WEAKENING FGEN FORCING SHIFTS TO THE EAST. WITH
MINIMAL/SKINNY MUCAPE AOB 400 J/KG AND NO TSRA OBSERVED TODAY...ONLY
SLIGHT CHANCE TSRA WAS RETAINED THROUGH THIS EVENING. AS THE TROUGH
CONTINUED TO DEEPEN AND LOW PRES OVER WRN LOWER MI LIFTS TO LAKE
HURON...NRLY FLOW WILL STRENGTHEN ACROSS UPPER MI. THE COMBINATION OF
THE MID LEVEL FORCING AND INCREASED ONSHORE/UPSLOPE FLOW WILL ALSO
BRING AN INCREASE IN LIGHT RAIN OR DRIZZLE INTO N CNTRL UPPER MI
OVERNIGHT.
TUE...AREAS OF LIGHT RAIN OR DRIZZLE MAY CONTINUE IN THE MORNING
THROUGH N CNTRL UPPER AND E UPPER MI AND GRADUALLY DIMINISH INTO THE
AFTERNOON AS THE DEEP MOISTURE FINALLY SLIDES TO THE EAST...PER NAM
850-700 MB RH FCST. OTHERWISE...COOLER CONDITIONS ARE EXPECTED WITH
BRISK NRLY WINDS KEEPING TEMPS IN THE 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 358 PM EDT MON AUG 11 2014
A 500MB LOW PRESSURE TROUGH OVER THE GREAT LAKES TUESDAY EVENING
WILL DEVELOP INTO A CUT OFF LOW OVER THE LOWER LAKES THURSDAY
MORNING...THEN LIFT INTO QUEBEC BY FRIDAY EVENING. AT THE
SURFACE...LOW PRESSURE OVER LAKE HURON WILL LIFT NORTHEASTWARD INTO
QUEBEC THROUGH WEDNESDAY EVENING. AS A RESULT...ONLY HAVE LINGERING
POPS FAR EAST CLOSEST TO THE LOW THROUGH WEDNESDAY EVENING. SOME OF
THE MODELS GENERATE PRECIPITATION WITH A SHORTWAVE THAT SWINGS
AROUND THE LOW ON WEDNESDAY AFTERNOON AND EVENING...BUT THINK THIS
MAY BE OVERDOING IT AS DRY AIR WILL START TO CREEP INTO THE AREA.
KEPT WEATHER ON WEDNESDAY DRY FOR NOW...BUT BUMPED UP SKY COVER WEST
AND ALONG THE WI BORDER AS WELL. WITH A STRONGER PRESSURE GRADIENT
ACROSS THE EASTERN PORTION OF LK SUPERIOR...HAVE ONSHORE/NORTHWEST
WINDS GUSTING 10 TO 20 MPH AND WAVE HEIGHTS AROUND 3 TO 4 FEET IN
ALGER COUNTY AND MAINLY FAR EASTERN MARQUETTE COUNTY NEAR LAKE
SUPERIOR. EXPECT A MODERATE SWIM RISK FOR DANGEROUS CURRENTS AND
WAVES IN THESE AREAS.
SURFACE HIGH PRESSURE MOVES FROM THE CANADIAN PRAIRIES/NORTHERN
PLAINS INTO THE GREAT LAKES BY THURSDAY AFTERNOON...SO HAVE KEPT A
SEASONABLY COOL BUT DRY FORECAST THROUGH THEN. AS THE CLOSED LOW
ALOFT MOVES FROM ONTARIO INTO QUEBEC ON FRIDAY UPPER LEVEL FLOW
BECOMES MORE ZONAL OVER UPPER MICHIGAN. THE SURFACE HIGH DRIFTS
SOUTHEASTWARD INTO THE OHIO VALLEY...MAKING WAY FOR A WEAK SURFACE
TROUGH TO DROP ACROSS NORTHERN LAKE SUPERIOR. WITH WEAK FORCING
ACROSS THE AREA...WOULDNT BE SURPRISED TO SEE ISOLATED
SHOWERS/TSTORMS ACROSS THE WESTERN AND NORTH CENTRAL PARTS OF THE
CWA. HAVE ADDED THEM IN ACCORDINGLY. THIS WEAK SURFACE TROUGH WILL
DRIVE ACROSS THE GREAT LAKES FRIDAY NIGHT INTO SATURDAY...SO HAVE
KEPT SLIGHT CHANCE POPS FOR THE WHOLE AREA.
A MORE POTENT 500MB SHORTWAVE ARRIVES SUNDAY NIGHT INTO
MONDAY...WITH THE ASSOCIATED SURFACE LOW PRESSURE CENTERED OVER
NORTHERN MN/NORTHWESTERN ONTARIO. ANOTHER SURFACE LOW DEVELOPS OVER
WI/IOWA AROUND THE SAME TIME AND MERGES WITH THE OTHER LOW OVER LAKE
SUPERIOR BY MONDAY EVENING. MODELS ARE IN SOMEWHAT OF A DISAGREEMENT
OVER THIS...AS USUAL WITH MERGING SYSTEMS/SHORTWAVES. HAVE KEPT
CONSENSUS CHANCE/SLIGHT CHANCE POPS FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY EVENING)
ISSUED AT 130 AM EDT TUE AUG 12 2014
MVFR CONDITIONS WILL CONTINUE AT IWD AND CMX OVERNIGHT BEFORE DRIER
AIR MOVES IN FOR TUE MORNING AND LEADS TO VFR CONDITIONS THROUGH THE
REST OF THE PERIOD.
RAIN ALONG WITH MOIST NORTHERLY FLOW WILL KEEP LIFR CIGS AT SAW
OVERNIGHT. CYCLONIC UPSLOPE FLOW INTO THE NORTH CENTRAL U.P. WILL
KEEP LOW CIGS AT KSAW INTO TUESDAY AFTERNOON BEFORE DRIER AIR AND
VFR CONDITIONS ARRIVE LATE TUE AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 447 AM EDT MON AUG 11 2014
A COLD FRONT WILL MOVE ACROSS THE LAKE TODAY. BEHIND THE COLD
FRONT...NORTH WINDS WILL INCREASE MON AND GUST TO MORE THAN 20 KT
MON NIGHT INTO TUE...PRODUCING WAVES UP TO 7 FT OVER THE CENTRAL AND
EASTERN LAKE. HIGH PRESSURE BUILDING INTO THE AREA BY WED NIGHT WILL
ALLOW WINDS TO ONCE AGAIN SUBSIDE TO BELOW 15 KT BY MID WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...07
MARINE...MZ
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
843 PM MDT WED AUG 13 2014
.UPDATE...
ONLY WEAK CONVECTION IN THE WEST THIS EVENING DUE TO LACK OF
STRONG FORCING/CAPE/SHEAR. WE DID HAVE A STRONG THUNDERSTORM IN
THE POWDERVILLE VICINITY WEST OF EKALAKA...BUT IT HAS SINCE FELL
APART. CURRENTLY WE HAVE SOME ISOLATED STORMS ALONG THE
FALLON/CUSTER COUNTY LINE MOVING SLOWLY E/NE. THESE STORMS ARE
MOVING INTO A LITTLE BIT BETTER ENVIRONMENT TO SUPPORT SOME
STRONGER UPDRAFTS...BUT WITH SETTING SUN I DONT FEEL WE WILL SEE
ANYTHING MORE THAN BRIEF HEAVY RAIN/SMALL HAIL WITH A CELL OR
TWO...AND PERHAPS A GOOD DEAL OF LIGHTNING.
EXPECT TO SEE SOME MORE SHOWERS LATER TONIGHT MOVE INTO THE
GALLATIN/BEARTOOTH RANGES AND PARK COUNTY. BIG SURGE OF MONSOON
RELATED MOISTURE STILL ON TARGET TO AFFECT OUR S/SE ZONES
TOMORROW. BT
&&
.SHORT TERM...VALID FOR THU AND FRI...
FAIRLY ACTIVE WEATHER COMING IN THE SHORT TERM PERIOD.
MID LEVEL SHORTWAVE IS ROUNDING THE RIDGE AND MOVING INTO EASTERN
MT THIS AFTN. SHOWERS WITHOUT TSTMS HAVE BEEN DEVELOPING FROM
ROSEBUD INTO CUSTER AND POWDER RIVER COUNTIES FOR THE PAST COUPLE
HOURS. LATEST ANALYSIS SUGGESTS 1500-2500 J/KG OF SBCAPE NEAR THE
DAKOTAS BORDER...WITH DIMINISHING CIN...SO WOULD ANTICIPATE SOME
STRONGER CELLS TO POP UP OVER THE NEXT FEW HOURS AS ASCENT REACHES
OUR FAR EAST. BULK SHEAR REMAINS 25 KTS OR LESS SO DO NOT SEE A
SIGNIFICANT SEVERE THREAT...THOUGH WILL HAVE TO WATCH ANY STRONGER
CELLS FOR SMALL HAIL AND HEAVY RAIN THROUGH MAYBE 02Z OR SO. HRRR
HAS CONSISTENTLY SHOWN CELLS DEVELOPING IN FALLON/CARTER COUNTIES
BY 22-23Z.
NEXT FEATURE OF INTEREST IS MONSOONAL ENERGY LIFTING THROUGH THE
FOUR CORNERS AREA EMBEDDED IN A VERY MOIST SOUTHERLY FLOW ALOFT.
PACIFIC NW LOW IS MOVING VERY SLOWLY...SO TRAJECTORY OF MONSOON
WAVE TAKES IT INTO OUR CWA BY EARLY TOMORROW...RATHER THAN BEING
DEFLECTED TO THE EAST. HRRR RUNS HAVE ALSO BEEN CONSISTENT WITH
SHOWING A LARGE AREA OF SHOWERS APPROACHING OUR AREA FROM THE
SOUTH LATER TONIGHT. GIVEN THE FORCING AND MOISTURE ANTICIPATED
WITH THIS WEAK MONSOON ENERGY...HAVE RAISED POPS ACROSS OUR SOUTH
AND SOUTHEAST BEGINNING EARLY TOMORROW MORNING AND LASTING THROUGH
THE EVENING IN OUR SOUTHEAST...AS ALL MODELS SHOW A MID LEVEL
CIRCULATION MOVING SLOWLY THROUGH SOUTHEAST MT. MAIN IMPACT WITH
THIS SYSTEM WILL BE PCPN AND NOT SEVERE WX...AS SHOWERS ARE
EXPECTED TO BEGIN EARLY IN THE DAY AND SFC TEMPS WILL BE COOLER.
THERE WILL BE SOME LIGHTNING BUT DO NOT SEE A LARGE AMOUNT FOR THE
SAME REASONS. WILL KEEP LALS AT 3 FOR TOMORROW. IT COULD ACTUALLY
BE A BENEFICIAL DAY AS FAR AS FIRE WEATHER GOES.
FURTHER WEST...PACIFIC NW LOW WILL MOVE SLOWLY EAST BUT WILL STILL
BE OVER WA/OR TOMORROW AFTN. STRONGER UPPER DIFFLUENCE WILL BE
WEST OF US...AND TO OUR WEST WILL BE WHERE THE RISK OF STRONGER
STORMS WILL BE...BUT SHOULD BE ENOUGH MOISTURE AND INSTABILITY
FOR SCATTERED AFTN AND EVENING TSTMS EVEN AS MONSOON LOW BEGINS
TO SHIFT EAST.
LATEST MODEL TRENDS SUGGEST PACIFIC LOW WILL DRIFT SLIGHTLY NORTH
BY FRIDAY...SOMEWHERE NEAR EASTERN WA/NORTHERN ID BY LATE IN THE
DAY. AS A RESULT WE WILL BEGIN TO TAP INTO DRIER AIR FROM THE
NORTHERN GREAT BASIN...GFS SHOWS PWATS NEAR A HALF INCH IN PARK
COUNTY...AND STRONGER JET SUPPORT WILL EXIST IN NORTH CENTRAL MT.
WILL KEEP POPS AT SCATTERED BUT HAVE TAPERED THEM SLIGHTLY...IE
COVERAGE SHOULD BE LESS THAN ON THURSDAY. ALSO...MONSOONAL LOW
SHOULD BE IN THE DAKOTAS BY FRIDAY BUT MAY BE CLOSE ENOUGH TO
BRING WRAP AROUND SHOWERS/TSTMS TO OUR EAST. SOME MODEL
UNCERTAINTY IN THIS REGARD.
AS FOR TEMPERATURES...INCREASED CHANCES OF PCPN AND CLOUD COVER
WILL GIVE US A COOLER DAY TOMORROW...WITH HIGHS MAINLY IN THE 80S
TO LOWER 90S. IF SHOWERS PERSIST LONG ENOUGH SOME PARTS OF OUR
SOUTH OR SOUTHEAST MAY STRUGGLE TO GET OUT OF THE 70S. THESE AREAS
WILL REBOUND WITH THE DRIER AIR ON FRIDAY.
JKL
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
THE UPPER LOW IN THE PACIFIC NORTHWEST WILL BEGIN ITS MOVE TO THE
NORTHEAST ACROSS THE MONTANA/CANADA BORDER SATURDAY INTO SUNDAY.
ASSOCIATED SURFACE TROUGH WILL DEVELOP ACROSS EASTERN MT ON
SATURDAY WITH LOW LEVEL SOUTHEAST FLOW AHEAD OF IT. LOOKS LIKE
GOOD SHEAR AND INSTABILITY FOR THE BEST CHANCE FOR STORMS IN THIS
AREA OF SOUTHEAST MT FOR SATURDAY WITH ISOLATED POTENTIAL
ELSEWHERE. UPPER LEVEL CYCLONIC FLOW REMAINS FOR SUNDAY AS THE
SYSTEM MAKES ONLY SLOW PROGRESS EAST...SO CANT RULE OUT SOME
INSTABILTIY SHOWERS/STORMS PERSISTING. A DRIER NORTHWEST FLOW IS
EXPECTED TO DOMINATE FROM MONDAY INTO THE MIDDLE OF NEXT WEEK.
LOOKS LIKE MOST AREAS SHOULD REMAIN DRY...OUTSIDE OF SOME ISOLATED
ACTIVITY IN THE MOUNTAINS. TEMPERATURES EXPECTED TO BE NEAR
SEASONAL LEVELS FOR MUCH OF THE PERIOD. FRIEDERS
&&
.AVIATION...
THE THREAT FOR ISOLATED THUNDERSTORMS CONTINUES THE REST OF THIS
EVENING...MAINLY WEST OF KBIL. LOCAL MVFR CONDITIONS...GUSTY
WINDS AND SOME MOUNTAIN OBSCURATIONS ARE POSSIBLE. OTHERWISE...
CLOUD COVER WILL INCREASE OVERNIGHT WITH THE POTENTIAL FOR MORE
WIDESPREAD SHOWERS MOVING IN BEGINNING THURSDAY MORNING AND
CONTINUING THROUGH THE DAY. FRIEDERS
&&
.PRELIMINARY POINT TEMP/POPS...
THU FRI SAT SUN MON TUE WED
-----------------------------------------------------------
BIL 065/087 063/089 062/088 061/088 061/088 061/090 061/085
24/T 43/T 32/T 22/T 21/B 11/U 11/B
LVM 056/088 054/088 053/087 052/088 052/088 053/089 053/087
35/T 54/T 42/T 22/T 22/T 21/B 22/T
HDN 061/088 060/091 059/090 058/090 058/090 058/092 058/088
25/T 43/T 32/T 22/T 21/B 11/U 11/B
MLS 065/092 064/089 064/090 061/089 061/090 061/091 062/088
13/T 44/T 44/T 42/T 21/B 11/B 11/B
4BQ 064/086 064/088 063/089 060/089 059/090 059/090 060/089
26/T 64/T 43/T 32/T 21/B 11/B 11/B
BHK 060/091 061/086 060/087 056/086 056/087 055/087 057/085
34/T 44/T 45/T 43/T 21/B 11/B 22/T
SHR 059/084 057/089 056/089 054/088 054/088 054/089 055/087
26/T 43/T 32/T 22/T 21/B 11/U 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
900 PM PDT WED AUG 13 2014
.SYNOPSIS...DRIER AIR MOVING IN FROM THE WEST WILL LIMIT
THUNDERSTORM COVERAGE MAINLY TO MOHAVE COUNTY THURSDAY AND FRIDAY.
DRY WEATHER AND NEAR NORMAL TEMPERATURES WILL OCCUR THROUGH THE
WEEKEND AND INTO EARLY NEXT WEEK.
&&
.UPDATE...MUCH QUIETER THIS EVENING THAN IN RECENT DAYS. SATELLITE
LOOP STILL SHOWS SOME CUMULUS BUBBLING OVER THE EASTERN CWA...AND
OUR EVENING SOUNDING HAD 1300 J/KG OF CAPE...SO NOT WILLING TO YANK
POPS JUST YET. NO CHANGE AT THIS TIME...BUT WILL CONTINUE TO MONITOR.
&&
.PREV DISCUSSION...
305 PM PDT WED AUG 13 2014
.DISCUSSION...SATELLITE SHOWING SOME HIGHER TOPPED CONVECTION
ACROSS THE MOUNTAINS OF SOUTHERN CLARK COUNTY/NORTHEAST SAN
BERNARDINO COUNTY. THE STRONGEST STORMS ALONG WITH ANY LIGHTNING
HAVE BEEN OVER FAR NORTHERN LINCOLN COUNTY.
TRIMMED BACK ON POPS SIGNIFICANTLY THIS EVENING BASED ON SATELLITE
AND HRRR DATA LEAVING A SLIGHT CHANCE IN MAINLY FOR LINCOLN/MOHAVE
AND SOUTHERN CLARK COUNTIES.
DRYING WILL CONTINUE THROUGH THURSDAY AND FRIDAY. MOS GUIDANCE
SURFACE DEWPOINTS FOR LAS VEGAS ARE TO FALL FROM OUR CURRENT 60 INTO
THE 40S THURSDAY AND 30S FRIDAY. THIS DRYING WILL LIMIT ANY
THUNDERSTORM THREAT TO FAR EASTERN LINCOLN/MOHAVE COUNTIES TOMORROW.
ON FRIDAY THE ONLY AREA WILL BE FAR EASTERN MOHAVE COUNTY. THE
FORECAST LOOKS TO STAY DRY THROUGH THE WEEKEND INTO EARLY NEXT WEEK.
AS WE LOOSE THE MOISTURE, DAYTIME HIGHS WILL WARM BACK CLOSER TO
NORMAL FROM SATURDAY ONWARD.
.AVIATION...FOR MCCARRAN...CUMULUS WHICH HAS DEVELOPED AROUND THE
SURROUNDING MTNS WILL DISSIPATE THIS EVENING LEAVING SKIES MOSTLY
CLEAR OVERNIGHT. ENOUGH MOISTURE WILL REMAIN IN PLACE FOR CUMULUS
DEVELOPMENT OVER THE MOUNTAINS THURSDAY AFTERNOON. WINDS SHOULD
CONTINUE TO FAVOR AN EAST-SOUTHEAST DIRECTION AT LESS THAN 10 KTS
INTO EARLY EVENING BEFORE SETTLING IN SOUTHERLY OVERNIGHT AND
THURSDAY
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED CLOUDS THIS EVENING AND AGAIN THURSDAY WITH A
SLIGHT CHANCE OF THUNDERSTORMS OVER LINCOLN/MOHAVE COUNTIES.
WINDS WILL FAVOR TYPICAL DIURNAL WIND PATTERNS THROUGH THURSDAY
EXCEPT NEAR THUNDERSTORMS THIS AFTERNOON.
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION SHOULD NOT BE
REQUIRED THURSDAY THROUGH THE WEEKEND.
&&
$$
MORGAN/PIERCE
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BUFFALO NY
206 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A DEEPENING AREA OF LOW PRESSURE WILL MOVE FROM SOUTHERN LAKE HURON
NORTH ACROSS ONTARIO AND DRAG SEVERAL FRONTAL BOUNDARIES ACROSS
WESTERN AND CENTRAL NEW YORK WHICH WILL PRODUCE SEVERAL ROUNDS OF
SHOWERS AND SCATTERED THUNDERSTORMS. BEHIND THIS SYSTEM...EXPECT A
COUPLE OF DAYS OF UNSETTLED AND COOL WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY THIS AFTERNOON SHOWING OCCASIONAL SHOWERS CROSSING THE
EASTERN LAKE ONTARIO REGION. THIS IS NOT PARTICULARLY ORGANIZED...
BUT MOST LOCATIONS WILL STILL SEE SOME OCCASIONAL LIGHT RAIN.
FARTHER WEST JUST A FEW SCATTERED SHOWERS ARE LINGERING FROM THE
GENESEE VALLEY INTO THE WESTERN FINGER LAKES. THIS SHOULD REMAIN
LIGHT AND WIDELY SCATTERED. A BAND OF CONVECTION IS SLOWLY
INCREASING OVER CENTRAL LAKE ERIE AND EASTERN OHIO...WHICH WILL MOVE
EAST INTO WESTERN NY BY LATE AFTERNOON.
SATELLITE IMAGERY SHOWING A FEW BINOVC DEVELOPING OVER LAKE ERIE AND
THE NIAGARA FRONTIER. THESE BREAKS SHOULD ALLOW FOR JUST ENOUGH
SURFACE HEATING TO YIELD SBCAPE OF 1000-1500J/KG BY MID TO LATE
AFTERNOON WITH CONTRIBUTION TO DESTABILIZATION FROM MID LEVEL HEIGHT
FALLS AND COOLING WITH THE APPROACH OF A STRONG MID LEVEL TROUGH.
INCREASING ASCENT IN THE DPVA REGION AHEAD OF THIS TROUGH COMBINED
WITH LOW LEVEL CONVERGENCE ALONG A SURFACE COLD FRONT AND
DIFFERENTIAL HEATING BOUNDARIES SHOULD SUPPORT A BROKEN BAND OF
CONVECTION BY LATE AFTERNOON ACROSS FAR WESTERN NY...WITH SUPPORT OF
THIS FROM MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR AND THE SSEO.
DEEP LAYER 0-6KM SHEAR OF AROUND 40 KNOTS COMBINED WITH MODEST BUT
SUFFICIENT INSTABILITY AND GOOD SYNOPTIC SUPPORT MAY ALLOW
CONVECTION TO GROW UPSCALE INTO ORGANIZED CLUSTERS AND BOWING
SEGMENTS...WITH SOME RISK OF ISOLATED DAMAGING WINDS. SOME OF THE
STRONGER CORES MAY ALSO PRODUCE MARGINAL SEVERE HAIL AND LOCALLY
HEAVY RAINFALL. GREATEST RISK OF SEVERE WILL BE FROM MID AFTERNOON
THROUGH MID EVENING FROM THE GENESEE VALLEY WESTWARD.
THE COLD FRONT CROSSES THE REGION OVERNIGHT JUST REACHING THE
EASTERN BORDER OF THE CWA TOWARD MORNING. THIS COMBINED WITH THE
APPROACH OF THE MID LEVEL TROUGH AXIS AND ASSOCIATED LARGE SCALE
ASCENT WILL KEEP SHOWERS AND A FEW THUNDERSTORMS GOING OVERNIGHT
WITH THE FOCUS FOR MORE ORGANIZED RAIN SHIFTING TO CENTRAL NY.
RAINFALL WISE...MOST AREAS CAN EXPECT TO SEE TOTALS OF ONE TO ONE
AND A HALF INCHES WITH THE GREATEST BASIN AVERAGE AMOUNTS EXPECTED
EAST OF LAKE ONTARIO. GIVEN THE RECENT DRY SPELL THESE AMOUNTS
SHOULD NOT POSE ANY BIG HYDRO CONCERNS. LOCALIZED HEAVIER
THUNDERSTORM RAINS COULD HOWEVER PRODUCE SOME LOCALIZED POOR
DRAINAGE ISSUES.
WINDS WILL INCREASE ACROSS THE EASTERN SECTIONS OF THE CWA LATER
TODAY/TONIGHT. BLACK RIVER VALLEY MAY SEE GUSTS APPROACHING 40 MPH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A DEEPENING UPPER LOW WILL MOVE FROM ITS CURRENT POSITION OVER THE
CENTRAL GREAT LAKES TO QUEBEC BY THURSDAY. THE ASSOCIATED SURFACE
COLD FRONT WILL LIKELY BE JUST EAST OF THE FORECAST AREA AS WE OPEN
THE DAY WEDNESDAY...NONETHELESS WITH SUCH STRONG UPPER LEVEL
TROUGHING MOVING OVERHEAD THE REGION...EXPECT SCATTERED SHOWERS TO
LINGER ACROSS THE AREA...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE
A PRONOUNCED UPSLOPE WESTERLY FLOW WILL AID IN ENHANCING SHOWER
CHANCES. THE COMBINATION OF INCREASINGLY COOL AIR ARRIVING ACROSS
THE REGION AND CLOUDINESS ASSOCIATED WITH THE UPPER LEVEL TROUGH
WILL KEEP TEMPERATURES WELL BELOW NORMAL WEDNESDAY WITH HIGHS
RANGING FROM THE MID-60S TO THE LOWER 70S.
SHOWER CHANCES WILL DIMINISH WEDNESDAY NIGHT BETWEEN THE LOSS OF
DIURNAL HEATING AND THE ADVECTION OF DRIER AIR OUT OF THE CANADIAN
ARCTIC ACROSS THE REGION. THAT SAID...WITH SUCH A STRONG TROUGH
HANGING AROUND...CANNOT RULE OUT A STRAY SHOWER OR
TWO...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE WESTERLY UPSLOPE
FLOW. LOOK FOR LOWS IN THE 50S WEDNESDAY NIGHT.
THURSDAY AND THURSDAY NIGHT WILL BE THE COOLEST PARTS OF THE WEEK AS
THE AFOREMENTIONED COLD ADVECTION REACHES ITS PEAK WITH 850MB TEMPS
DROPPING AS LOW AS +5 TO +7C. THIS WILL ONLY SUPPORT HIGHS IN THE
60S ACROSS THE FORECAST AREA WITH LOW TO MID 50S THURSDAY
NIGHT...WHILE PORTIONS OF THE SOUTHERN TIER WILL LIKELY FALL INTO
THE UPPER 40S. THE MITIGATING FACTOR IN KEEPING TEMPERATURES FROM
PLUNGING LOWER THURSDAY NIGHT WILL BE THE PERSISTENT WESTERLY FLOW
AND RESULTING LAKE EFFECT CLOUD COVER. SPEAKING OF LAKE
EFFECT...WITH TEMPERATURES ALOFT COOLING TO +5C...WE MAY SEE MORE
LAKE ENHANCED/UPSLOPE SHOWER ACTIVITY EAST OF LAKE ONTARIO THURSDAY
AND THURSDAY NIGHT WHILE PERSISTENT DRY AIR ALOFT WILL KEEP SHOWERS
LIMITED TO JUST A SLIGHT CHANCE ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE UPPER LEVEL LOW WILL DRIFT ACROSS QUEBEC FRIDAY BEFORE
EVENTUALLY LIFTING NORTHEAST INTO LABRADOR THIS WEEKEND. WITHT HE
DEPARTURE OF THE LOW AND ASSOCIATED TROUGHING...TEMPERATURES WILL
RECOVER NICELY BACK INTO THE 70S BY THE WEEKEND AS HIGH PRESSURE
SLIDES BY TO OUR SOUTH.
WHILE FRIDAY NIGHT AND SATURDAY LOOK TO BE DRY FOR MUCH OF THE
FORECAST AREA...CONDITIONS MAY BECOME MORE UNSETTLED FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY INTO MONDAY AS ANOTHER SHORTWAVE IS
PROGGED TO DROP ACROSS THE GREAT LAKES. MODEL AGREEMENT ON THE
POSITION/TIMING OF THIS FEATURE IS SHAKY AT BEST AT THIS TIME
HOWEVER...PARTICULARLY AS SOME SOLUTIONS HAVE THIS FEATURE
INTERACTING WITH A CUTOFF LOW DRIFTING OUT OF THE CENTRAL PLAINS
STATES. GIVEN ALL OF THIS UNCERTAINTY...AM KEEPING POPS IN THE
SLIGHT CHANCE RANGE FOR NOW WITH TEMPERATURES TRENDING TOWARDS
CLIMATOLOGY WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER
50S/LOWER 60S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
THE LOWER ELEVATIONS HAVE IMPROVED MAINLY TO VFR THIS AFTERNOON WITH
SOME MVFR/IFR CIGS LINGERING ACROSS HIGHER TERRAIN. THIS WILL
CONTINUE FOR SEVERAL MORE HOURS. OCCASIONAL RAIN SHOWERS WILL
CONTINUE THROUGH MID TO LATE AFTERNOON ACROSS THE EASTERN LAKE
ONTARIO REGION...BUT CIGS/VSBY WILL BE VFR MUCH OF THE TIME IN THIS
ACTIVITY. FARTHER WEST...A BAND OF CONVECTION IS EXPECTED TO MOVE
INTO WESTERN NY BY 20-21Z WITH A 1-3 HOUR PERIOD OF TSRA AND BRIEF
REDUCTIONS TO MVFR/IFR CONDITIONS INCLUDING KBUF-KIAG-KJHW. THIS
WILL MOVE EAST AND CROSS THE GENESEE VALLEY INCLUDING KROC DURING
THE 22Z-01Z TIME FRAME...THEN SLOWLY WEAKEN AND BROADEN INTO A
LARGER AREA OF RAIN WITH A FEW EMBEDDED THUNDERSTORMS OVERNIGHT EAST
OF LAKE ONTARIO. THIS WILL CONTINUE TO PRODUCE AREAS OF MVFR/IFR IN
THAT AREA INCLUDING KART.
BEHIND THE AREA OF CONVECTION...A PERIOD OF IFR CIGS APPEARS LIKELY
AGAIN OVERNIGHT ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TIER AND
FINGER LAKES WITH MOIST LOW LEVEL UPSLOPE FLOW. BOUNDARY LAYER
MIXING AND CLOUD COVER SHOULD PREVENT MUCH IN THE WAY OF
FOG...ALTHOUGH A FEW HILLTOPS MAY GET INTO LOCAL FOG IF THE STRATUS
LAYER INTERSECTS THE TERRAIN.
ON WEDNESDAY THE LOW CIGS ACROSS THE HIGHER TERRAIN WILL IMPROVE TO
MVFR BY LATE MORNING WITH FURTHER IMPROVEMENT TO VFR BY AFTERNOON.
STEADIER RAIN EAST OF LAKE ONTARIO EARLY WITH LOCAL MVFR/IFR WILL
TAPER OFF. ANOTHER BROKEN BAND OF SHOWERS WILL MOVE INTO WESTERN NY
VERY EARLY WEDNESDAY MORNING THEN PROGRESS EAST ACROSS THE AREA
DURING THE DAY WITH A BRIEF PERIOD OF MVFR. SCATTERED SHOWERS AND
ISOLATED THUNDER WILL DEVELOP DURING THE AFTERNOON INLAND FROM THE
LAKES BUT COVERAGE SHOULD REMAIN RATHER SPARSE WITH VFR PREVAILING
IN MOST PLACES DURING THE AFTERNOON.
OUTLOOK...
THURSDAY AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS
ESPECIALLY EAST OF THE LAKES.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MAINLY VFR WITH A CHANCE OF SHOWERS.
&&
.MARINE...
UNSETTLED WEATHER WILL MOVE INTO THE LOWER GREAT LAKES REGION AS A
DEEPENING LOW MOVES FROM SOUTHERN LAKE HURON ACROSS ONTARIO AND ONTO
QUEBEC. S WINDS WILL CONTINUE TO PRODUCE SMALL CRAFT ADVISORY
CONDITIONS AT THE EAST END OF LAKE ONTARIO THIS AFTERNOON.
ADDITIONAL SCA MAY BE NEEDED POST COLD-FRONTAL LATER
TONIGHT/WEDNESDAY. COOLER TEMPERATURES ALOFT WILL BE MARGINALLY
FAVORABLE FOR FOR WATERSPOUT FORMATION WEDNESDAY THROUGH THE END
OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR LOZ044-
045.
&&
$$
SYNOPSIS...HITCHCOCK/LEVAN
NEAR TERM...HITCHCOCK/LEVAN
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...HITCHCOCK
MARINE...HITCHCOCK/LEVAN
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1049 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A DEEPENING AREA OF LOW PRESSURE WILL MOVE FROM SOUTHERN LAKE HURON
NORTH ACROSS ONTARIO AND DRAG SEVERAL FRONTAL BOUNDARIES ACROSS
WESTERN AND CENTRAL NEW YORK WHICH WILL PRODUCE SEVERAL ROUNDS OF
SHOWERS AND SCATTERED THUNDERSTORMS. BEHIND THIS SYSTEM...EXPECT A
COUPLE OF DAYS OF UNSETTLED AND COOL WEATHER.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR IMAGERY LATE THIS MORNING SHOWING THE STEADIER SHOWERS
SHIFTING INTO CENTRAL NY WITHIN A REGION OF STRONGER LOW LEVEL
CONVERGENCE ALONG A SLOW MOVING WARM FRONTAL BOUNDARY SUPPORTED BY A
40+ KNOT LOW LEVEL JET. BEHIND THESE STEADIER SHOWERS A FEW MORE
WIDELY SCATTERED SHOWERS ARE STILL FOUND ACROSS THE INTERIOR
SOUTHERN TIER AND WESTERN FINGER LAKES. EXPECT THE STEADIER SHOWERS
TO CONTINUE ACROSS CENTRAL NY AND THE NORTH COUNTRY INTO MID
AFTERNOON. ACROSS WESTERN NY...THE BREAK IN THE RAIN ON THE LAKE
PLAINS SHOULD LAST THROUGH EARLY TO MID AFTERNOON BEFORE CONVECTION
BEGINS TO BREAK OUT NEAR PEAK HEATING.
SATELLITE IMAGERY SHOWING A FEW BINOVC DEVELOPING OVER LAKE ERIE AND
THE NIAGARA FRONTIER. THESE BREAKS SHOULD ALLOW FOR JUST ENOUGH
SURFACE HEATING TO YIELD SBCAPE OF 1000-1500J/KG BY MID TO LATE
AFTERNOON WITH CONTRIBUTION TO DESTABILIZATION FROM MID LEVEL HEIGHT
FALLS AND COOLING WITH THE APPROACH OF A STRONG MID LEVEL TROUGH.
INCREASING ASCENT IN THE DPVA REGION AHEAD OF THIS TROUGH COMBINED
WITH LOW LEVEL CONVERGENCE ALONG A SURFACE COLD FRONT AND
DIFFERENTIAL HEATING BOUNDARIES SHOULD SUPPORT A BROKEN BAND OF
CONVECTION BY LATE AFTERNOON ACROSS FAR WESTERN NY...WITH SUPPORT OF
THIS FROM MESOSCALE MODEL GUIDANCE SUCH AS THE HRRR AND THE SSEO.
DEEP LAYER 0-6KM SHEAR OF AROUND 40 KNOTS COMBINED WITH MODEST BUT
SUFFICIENT INSTABILITY AND GOOD SYNOPTIC SUPPORT MAY ALLOW
CONVECTION TO GROW UPSCALE INTO ORGANIZED CLUSTERS AND BOWING
SEGMENTS...WITH SOME RISK OF ISOLATED DAMAGING WINDS. SOME OF THE
STRONGER CORES MAY ALSO PRODUCE MARGINAL SEVERE HAIL AND LOCALLY
HEAVY RAINFALL. GREATEST RISK OF SEVERE WILL BE FROM MID AFTERNOON
THROUGH MID EVENING FROM THE GENESEE VALLEY WESTWARD.
THE COLD FRONT CROSSES THE REGION OVERNIGHT JUST REACHING THE
EASTERN BORDER OF THE CWA TOWARD MORNING. THIS COMBINED WITH THE
APPROACH OF THE MID LEVEL TROUGH AXIS AND ASSOCIATED LARGE SCALE
ASCENT WILL KEEP SHOWERS AND A FEW THUNDERSTORMS GOING OVERNIGHT
WITH THE FOCUS FOR MORE ORGANIZED RAIN SHIFTING TO CENTRAL NY.
RAINFALL WISE...MOST AREAS CAN EXPECT TO SEE TOTALS OF ONE TO ONE
AND A HALF INCHES WITH THE GREATEST BASIN AVERAGE AMOUNTS EXPECTED
EAST OF LAKE ONTARIO. GIVEN THE RECENT DRY SPELL THESE AMOUNTS
SHOULD NOT POSE ANY BIG HYDRO CONCERNS. LOCALIZED HEAVIER
THUNDERSTORM RAINS COULD HOWEVER PRODUCE SOME LOCALIZED POOR
DRAINAGE ISSUES.
WINDS WILL INCREASE ACROSS THE EASTERN SECTIONS OF THE CWA LATER
TODAY/TONIGHT. BLACK RIVER VALLEY MAY SEE GUSTS APPROACHING 40 MPH.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
A DEEPENING UPPER LOW WILL MOVE FROM ITS CURRENT POSITION OVER THE
CENTRAL GREAT LAKES TO QUEBEC BY THURSDAY. THE ASSOCIATED SURFACE
COLD FRONT WILL LIKELY BE JUST EAST OF THE FORECAST AREA AS WE OPEN
THE DAY WEDNESDAY...NONETHELESS WITH SUCH STRONG UPPER LEVEL
TROUGHING MOVING OVERHEAD THE REGION...EXPECT SCATTERED SHOWERS TO
LINGER ACROSS THE AREA...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE
A PRONOUNCED UPSLOPE WESTERLY FLOW WILL AID IN ENHANCING SHOWER
CHANCES. THE COMBINATION OF INCREASINGLY COOL AIR ARRIVING ACROSS
THE REGION AND CLOUDINESS ASSOCIATED WITH THE UPPER LEVEL TROUGH
WILL KEEP TEMPERATURES WELL BELOW NORMAL WEDNESDAY WITH HIGHS
RANGING FROM THE MID-60S TO THE LOWER 70S.
SHOWER CHANCES WILL DIMINISH WEDNESDAY NIGHT BETWEEN THE LOSS OF
DIURNAL HEATING AND THE ADVECTION OF DRIER AIR OUT OF THE CANADIAN
ARCTIC ACROSS THE REGION. THAT SAID...WITH SUCH A STRONG TROUGH
HANGING AROUND...CANNOT RULE OUT A STRAY SHOWER OR
TWO...PARTICULARLY ACROSS THE NORTH COUTNRY WHERE WESTERLY UPSLOPE
FLOW. LOOK FOR LOWS IN THE 50S WEDNESDAY NIGHT.
THURSDAY AND THURSDAY NIGHT WILL BE THE COOLEST PARTS OF THE WEEK AS
THE AFOREMENTIONED COLD ADVECTION REACHES ITS PEAK WITH 850MB TEMPS
DROPPING AS LOW AS +5 TO +7C. THIS WILL ONLY SUPPORT HIGHS IN THE
60S ACROSS THE FORECAST AREA WITH LOW TO MID 50S THURSDAY
NIGHT...WHILE PORTIONS OF THE SOUTHERN TIER WILL LIKELY FALL INTO
THE UPPER 40S. THE MITIGATING FACTOR IN KEEPING TEMPERATURES FROM
PLUNGING LOWER THURSDAY NIGHT WILL BE THE PERSISTENT WESTERLY FLOW
AND RESULTING LAKE EFFECT CLOUD COVER. SPEAKING OF LAKE
EFFECT...WITH TEMPERATURES ALOFT COOLING TO +5C...WE MAY SEE MORE
LAKE ENHANCED/UPSLOPE SHOWER ACTIVITY EAST OF LAKE ONTARIO THURSDAY
AND THURSDAY NIGHT WHILE PERSISTENT DRY AIR ALOFT WILL KEEP SHOWERS
LIMITED TO JUST A SLIGHT CHANCE ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE UPPER LEVEL LOW WILL DRIFT ACROSS QUEBEC FRIDAY BEFORE
EVENTUALLY LIFTING NORTHEAST INTO LABRADOR THIS WEEKEND. WITHT HE
DEPARTURE OF THE LOW AND ASSOCIATED TROUGHING...TEMPERATURES WILL
RECOVER NICELY BACK INTO THE 70S BY THE WEEKEND AS HIGH PRESSURE
SLIDES BY TO OUR SOUTH.
WHILE FRIDAY NIGHT AND SATURDAY LOOK TO BE DRY FOR MUCH OF THE
FORECAST AREA...CONDITIONS MAY BECOME MORE UNSETTLED FOR THE SECOND
HALF OF THE WEEKEND AND POSSIBLY INTO MONDAY AS ANOTHER SHORTWAVE IS
PROGGED TO DROP ACROSS THE GREAT LAKES. MODEL AGREEMENT ON THE
POSITION/TIMING OF THIS FEATURE IS SHAKY AT BEST AT THIS TIME
HOWEVER...PARTICULARLY AS SOME SOLUTIONS HAVE THIS FEATURE
INTERACTING WITH A CUTOFF LOW DRIFTING OUT OF THE CENTRAL PLAINS
STATES. GIVEN ALL OF THIS UNCERTAINTY...AM KEEPING POPS IN THE
SLIGHT CHANCE RANGE FOR NOW WITH TEMPERATURES TRENDING TOWARDS
CLIMATOLOGY WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER
50S/LOWER 60S.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
A MIX OF VFR AND MVFR CONDITIONS WILL PREVAIL ACROSS THE LOWER
ELEVATIONS FOR MUCH OF THE DAY AS LOW PRESSURE DEEPENS OVER LAKE
HURON AND LIFTS NORTH ACROSS ONTARIO. LINES OF CONVECTION ARE
ANTICIPATED ACROSS THE WEST THIS AFTERNOON IN ADVANCE OF AN
APPROACHING COLD FRONT. SOME OF THE RAIN/THUNDERSTORMS MAY BE HEAVY
WITH CONDITIONS BRIEFLY LOWERING TO IFR. ACROSS THE HIGHER TERRAIN
OF THE SOUTHERN TIER AND FINGER LAKES AREAS OF IFR CIGS WILL
CONTINUE THROUGH MIDDAY BEFORE SLOWLY IMPROVING TO MVFR THIS
AFTERNOON.
OUTLOOK...
WEDNESDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS AND THUNDERSTORMS.
THURSDAY AND FRIDAY...VFR WITH A CHANCE OF MVFR IN SHOWERS.
SATURDAY...VFR.
&&
.MARINE...
UNSETTLED WEATHER WILL MOVE INTO THE LOWER GREAT LAKES REGION AS A
DEEPENING LOW MOVES FROM SOUTHERN LAKE HURON ACROSS ONTARIO AND ONTO
QUEBEC. S-SW WINDS WILL CREATE SMALL CRAFT ADVISORY CONDITIONS ON
ALL NEARSHORE WATERS TODAY. CHOPPY CONDITIONS ARE EXPECTED TO LAST
THROUGH WEDNESDAY. CURRENT SMALL CRAFT ADVISORIES WILL EXPIRE THIS
AFTERNOON. ADDITIONAL SCA MAY BE NEEDED POST COLD-FRONTAL LATER
TONIGHT/WEDNESDAY. COOLER TEMPERATURES ALOFT WILL BE MARGINALLY
FAVORABLE FOR FOR WATERSPOUT FORMATION WEDNESDAY THROUGH THE END OF
THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LEZ020-
040-041.
SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR
LOZ042-043.
SMALL CRAFT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR
LOZ044-045.
&&
$$
SYNOPSIS...HITCHCOCK/LEVAN
NEAR TERM...HITCHCOCK/LEVAN
SHORT TERM...WOOD
LONG TERM...WOOD
AVIATION...LEVAN
MARINE...HITCHCOCK/LEVAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
330 PM EDT TUE AUG 12 2014
.SYNOPSIS...
LINGERING TROPICAL MOISTURE ACROSS THE CAROLINAS WILL TRIGGER
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH EARLY WEDNESDAY. A
COLD FRONT WILL CROSS THE COAST OVERNIGHT WEDNESDAY...BRINGING A
DRYING TREND ALONG WITH COOLER OVERNIGHT TEMPERATURES. SEASONABLE
WEATHER FOR MID-AUGUST IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 330 PM TUESDAY...VISIBLE SATELLITE IMAGERY SHOWS A WELL-
DEFINED COLD FRONT FROM THE GREAT LAKES EXTENDING SOUTH INTO
TENNESSEE AND NORTHERN ALABAMA. AHEAD OF THIS FRONT A MARITIME
TROPICAL AIRMASS WITH PRECIPITABLE WATER VALUES OF AS HIGH AS 2.2
INCHES IS YIELDING SCATTERED SHOWERS & T-STORMS...MAINLY ACROSS
SOUTH CAROLINA BUT ALSO EXPANDING IN COVERAGE ACROSS WESTERN AND
CENTRAL NC. SURFACE-BASED CAPE IS AS HIGH AS 2500 J/KG AND SHOULD
PROVIDE PLENTY OF FUEL FOR THESE STORMS THROUGH THE LATE AFTERNOON
AND EVENING HOURS.
A RELATIVELY DEEP UPPER TROUGH FROM THE WESTERN GREAT LAKES EXTENDS
DOWN THROUGH THE MISSISSIPPI RIVER VALLEY. ACCELERATING MID-LEVEL
FLOW AHEAD OF THIS TROUGH WILL LEAD TO FASTER STORM MOTION THAN WE
HAVE SEEN OVER THE PAST SEVERAL DAYS...15-20 MPH AND POTENTIALLY
INCREASING FURTHER IF A WELL-DEFINED COLD POOL CAN DEVELOP AND PUSH
STORMS OUTWARD DUE TO THERMAL/DENSITY-DRIVEN EFFECTS.
I HAVE HELD FORECAST POPS TONIGHT IN THE 40-50 PERCENT RANGE WITH
THE EXCEPTION OF THE 60-70 POPS OVER THE NEXT FEW HOURS ACROSS
WILLIAMSBURG AND SOUTHERN FLORENCE COUNTIES. THE REASON I DON`T FEEL
COMFORTABLE GOING HIGHER IS THE LACK OF UPPER LEVEL SUPPORT FOR
STORMS. A 250 MB JET STREAK IS FAVORABLY VENTILATING THE STORMS
ACROSS THE NC/VA FOOTHILLS BUT IS SHOWN ON 12Z MODELS TO REMAIN TOO
FAR WEST TO DIRECTLY IMPACT OUR STORMS ACROSS THE EASTERN CAROLINAS.
AT 500 MB A STRUNG-OUT VORT MAX AHEAD OF THE UPPER TROUGH IS
BECOMING CHANNELED ALONG WITH THE GEOSTROPHIC FLOW AND MAY NOT BE
ABLE TO ENHANCE UPWARD MOTION AS IT APPROACHES THE AREA OVERNIGHT.
UTILIZING MOS BIASES OBSERVED OVER THE PAST FEW DAYS MY FORECAST
LOWS ARE A BIT ABOVE GUIDANCE TONIGHT...74-77 AT THE COAST AND 71-74
INLAND.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 330 PM TUESDAY...A COLD FRONT WILL BE DRAPED ACROSS OUR CWA
WED MORNING...LIKELY BISECTING OUR INLAND AND COASTAL ZONES AT THE
START OF THE PERIOD. AHEAD OF THE FRONT...FORECAST SOUNDINGS
DEPICT ENOUGH MOISTURE TO WARRANT MAINTAINING SLIGHT CHC POPS
MAINLY ALONG THE COAST BEFORE 18Z WED. AS THE UPPER TROUGH AXIS
MOVES OFFSHORE WED AFTN...DRIER AIR WILL QUICKLY FILTER INTO THE
AREA WITH SUBSIDENCE ALOFT EFFECTIVELY BRINGING AN END TO OUR RAIN
CHANCES. THE COLD FRONT WILL FINALLY PUSH THROUGH LATE WED/EARLY
THU...AS PWATS CONTINUE TO FALL TO BELOW 1.0 INCH BY 12Z THU.
AFTER NEARLY A WEEK OF CLOUDY AND RAINY WEATHER...THU WILL BE A
WELCOMED RELIEF AS MOSTLY SUNNY AND DRY CONDITIONS PREVAIL ACROSS
THE EASTERN CAROLINAS.
EXPECT NEAR SEASONABLE HIGHS ON WED WITH SLIGHT COOLER DAYTIME TEMPS
ON THU...MID TO UPPER 80S...IN THE WAKE OF THE COLD FRONT. OVERNIGHT
LOWS WILL RUN SEVERAL DEGREES BELOW NORMAL BOTH NIGHTS...GENERALLY
MID TO UPPER 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 330 PM TUESDAY...A RETURN TO SUMMER-LIKE WEATHER WILL
FINALLY OCCUR AS FLOW FLATTENS ALOFT AND OFFSHORE HIGH PRESSURE
BECOMES THE DOMINANT SYNOPTIC FEATURE.
LARGE UPPER TROUGH WILL PERSIST ACROSS THE EASTERN CONUS INTO
SATURDAY...BUT FORTUNATELY IN A WEAKENING STATE. TROUGH AXIS
OVERHEAD FRIDAY KEEPS DRY WESTERLY FLOW ALOFT...AND THUS PWATS
REMAIN LESS THAN 1.5 INCHES WHICH COMBINED WITH BELOW NORMAL TEMPS
SUGGESTS LIMITED TO NO CONVECTIVE POTENTIAL FRIDAY. CANNOT RULE OUT
AN ISOLATED SHOWER OR STORM ALONG THE SEA BREEZE FRIDAY...BUT WILL
KEEP ONLY LESS THAN 20 POP ALONG THE COAST. UPPER TROUGH REMAINS IN
PLACE ON SATURDAY...WHICH WHEN COMBINED WITH SLOWLY INCREASING TEMPS
AND ENHANCED MOIST RETURN FLOW...WILL SUPPORT SLIGHTLY GREATER
CHANCES FOR AFTN CONVECTION ON SATURDAY.
MORE TYPICAL AUGUST WEATHER DEVELOPS SUNDAY AND PERSISTS INTO NEXT
WEEK AS HIGH PRESSURE OFFSHORE BECOMES THE PRIMARY SENSIBLE-WEATHER
MAKER...AND THE UPPER TROUGH FLATTENS ALLOWING FOR BROAD RIDGING TO
DEVELOP ACROSS THE SOUTHERN TIER. WHILE THIS WILL CREATE A SLOW
WARMING TREND...WITH TEMPS RISING TO SLIGHTLY ABOVE CLIMO NEXT
WEEK...IT WILL ALSO SUPPORT INCREASING CONVECTIVE CHANCES AS PWATS
RISE BACK TOWARDS 2 INCHES AND THE PIEDMONT TROUGH BECOMES ACTIVE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO TREND THE CONVECTION LATER
IN THE AFTERNOON AND INTO EVENING HOURS. THERE SHOULD ALSO BE SOME
CONVECTION ALONG THE RESULTANT BOUNDARY A BIT EARLIER...HOWEVER MOST
OF THE ACTIVITY WILL BE INLAND FROM THE COASTAL TERMINALS. BRIEF
HEAVY RAIN IS EXPECTED WITH PWATS OVER TWO INCHES NEAR THE COAST.
TONIGHT...CONVECTION WILL FINALLY WIND DOWN AROUND 02-03Z...WITH
PATCHY FOG EXPECTED...MAINLY IN THE AREAS WHERE IT RAINED. WINDS
WILL SHIFT TO THE WEST WEDNESDAY AS A FRONT PUSHES THROUGH THE
REGION. THERE IS A SLIGHT CHANCE FOR SHOWERS IMMEDIATELY ALONG THE
FRONT TOMORROW...CONFIDENCE LOW.
EXTENDED OUTLOOK...VFR THURS THROUGH SAT. CHANCE FOR SHOWERS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 PM TUESDAY...ALL EYES ARE FOCUSED ON A COLD FRONT
EXTENDING SOUTH FROM THE GREAT LAKES INTO EASTERN TENNESSEE AND
NORTHERN ALABAMA. THIS FRONT WILL MOVE INTO THE COASTAL PLAIN LATE
TONIGHT. AHEAD OF THE FRONT SOUTHWEST WINDS WILL INCREASE TO 10-15
KNOTS WITH SEAS BUILDING FROM THE CURRENT 2 FT TO AS HIGH AS 3-4
FT AWAY FROM SHORE OVERNIGHT. SCATTERED SHOWERS AND T-STORMS HAVE
DEVELOPED INLAND WITH SOME ISOLATED CELLS FIRING UP ALONG THE
SEABREEZE BOUNDARY VERY CLOSE TO THE BEACHES. ISOLATED CONVECTION
THIS AFTERNOON WILL TEND TO BECOME A LITTLE MORE WIDESPREAD THIS
EVENING...PERHAPS CONTINUING OVERNIGHT AS WARM AND HUMID SOUTHWEST
WINDS CONTINUE. BESIDES LIGHTNING...THE BIGGEST RISK WITH THESE
STORMS MAY BE SUDDEN VISIBILITY RESTRICTIONS IN HEAVY RAINFALL.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 PM TUESDAY...SOUTHWEST FLOW 10-15 KT AHEAD OF AN
APPROACHING COLD FRONT WILL PRODUCE 3-4 FT SEAS DURING THE DAY
WED. THIS FRONT WILL FINALLY PUSH OFFSHORE OVERNIGHT WED...WITH
WINDS BECOMING NORTHWEST AOB 10 KTS EARLY THU MORNING. WEAK
PRESSURE GRADIENT DURING THE DAY THU WILL RESULT IN LIGHT
NORTHEAST WINDS... BECOMING VRBL INTO THU NIGHT. SEAS ON THU WILL
GRADUALLY SUBSIDE TO 2-3 FT DURING THE DAY AND EVENTUALLY 2 FT BY
THE END OF THE PERIOD.
LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 330 PM TUESDAY...AFTER A BRIEF PERIOD OF VARIABLE WINDS
EARLY FRIDAY...HIGH PRESSURE OFFSHORE WILL BECOME THE CONTROLLING
SYNOPTIC FEATURE...AND WINDS WILL BE PRIMARILY S/SW THROUGH THE
PERIOD. ALTHOUGH THE PRESSURE GRADIENT WILL REMAIN RELAXED FRI AND
SAT...BY SUNDAY IT WILL BEGIN TO TIGHTEN...AND THUS WINDS WILL
RISE FROM 5-10 KTS FRI/SAT...TO 10-15 KTS SUNDAY...WITH A MORE
VEERED DIRECTION TO SW. SEAS OF AROUND 2 FT WILL BE COMMON
FRI/SAT...RISING TO 2-4 FT ON SUNDAY THANKS TO THE STRONGER WINDS
AND A SLOWLY AMPLIFYING SE SWELL.
&&
.TIDES/COASTAL FLOODING...
AS OF 330 PM TUESDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
TONIGHTS HIGH TIDE FOR THE LOWER CAPE FEAR RIVER SIMILAR TO THE
LAST 3 EVENINGS...BUT LIKELY A FEW INCHES LOWER ON THE PEAK WATER
LEVELS. ELEVATED LEVELS WILL BE OBSERVED ALONG THE BANKS OF THE
ICW AS WELL DURING HIGH TIDE LATE TONIGHT. THE LOWER CAPE FEAR
RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING LOCALIZED
AREAS OF DOWNTOWN WILMINGTON. NO COASTAL FLOOD ADVISORIES FOR THE
BEACHES EXPECTED AS ASTRONOMICAL PULLS HAVE ABATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
SYNOPSIS...BJR
NEAR TERM...TRA
SHORT TERM...BJR
LONG TERM...JDW
AVIATION...DL
MARINE...TRA/JDW/BJR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 PM EDT TUE AUG 12 2014
.SYNOPSIS...
LINGERING TROPICAL MOISTURE ACROSS THE CAROLINAS WILL TRIGGER
SCATTERED TORRENTIAL SHOWERS AND THUNDERSTORMS THROUGH EARLY
WEDNESDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON THURSDAY...
BRINGING A DRYING TREND ALONG WITH COOLER OVERNIGHT TEMPERATURES.
SEASONABLE WEATHER FOR MIDDLE AUGUST IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM TUESDAY...RADAR SHOWS THE FIRST SHOWERS OF THE DAY HAVE
DEVELOPED ACROSS WILLIAMSBURG COUNTY SC. SATELLITE SHOWS THE CUMULUS
FIELD IS MOST "AGITATED" FROM THERE EASTWARD TO GEORGETOWN. A PEEK
OUTSIDE THE WEATHER OFFICE SHOWS THE CUMULUS OVER WILMINGTON HAVE
ONLY MINOR VERTICAL GROWTH SO FAR. NO SIGNIFICANT CHANGES ARE BEING
MADE TO THE FORECAST AT THIS TIME. PREVIOUS DISCUSSION FROM 1030 AM
FOLLOWS...
THIS MORNING`S FORECAST UPDATE FEATURES NO SIGNIFICANT CHANGES FROM
THE PREVIOUS FORECAST. THE STATIONARY FRONT THAT HAD BEEN STALLED
ACROSS SOUTH CAROLINA FOR THE PAST COUPLE OF DAYS HAS LIFTED
NORTHWARD INTO NORTHERN NORTH CAROLINA...ACCOMPANIED BY A WEAK AREA
OF LOW PRESSURE. THIS WILL REMOVE SOME OF THE LOW-LEVEL FORCING THAT
FAVORED WIDESPREAD THUNDERSTORM ACTIVITY OVER THE PAST FEW DAYS.
MORNING LOW STRATUS AND FOG IS BURNING OFF AND SHOULD HAVE ITS
MOISTURE INCORPORATED INTO AN ACTIVE CUMULUS FIELD THIS AFTERNOON.
THE ATMOSPHERE IS VERY MOIST AND CONDITIONALLY UNSTABLE.
PRECIPITABLE WATER VALUES WERE 2.1 TO 2.2 INCHES ON THE 12Z MHX AND
CHS SOUNDINGS. ASSUMING HIGH TEMPERATURES REACH THE UPPER 80S TO
AROUND 90 LOOK FOR SURFACE-BASED CAPE TO RISE TO NEAR 2000 J/KG WITH
NO CAPPING AND LIFTED INDICES AROUND -5. STEERING FLOW AND SURFACE
WINDS ARE CURRENTLY VERY LIGHT...BUT AS THE DAY PROGRESSES AN
APPROACHING UPPER LEVEL TROUGH AND SURFACE COLD FRONT (NOW ACROSS
THE OHIO VALLEY INTO TENNESSEE) WILL CAUSE AN ACCELERATION OF WINDS
THROUGHOUT THE TROPOSPHERE. THIS WILL NOT APPRECIABLY AFFECT STORM
ORGANIZATION BUT WILL INCREASE STORM MOTION TO 15-20 MPH BY LATE IN
THE DAY. HIGH PRECIPITABLE WATER VALUES PLUS A VERY DEEP WARM CLOUD
LAYER FOR EFFICIENT COALESCENCE-DOMINATED PRECIPITATION PROCESSES TO
OCCUR BOTH ARGUE FOR INCLUSION OF HEAVY RAIN MENTION IN THE FORECAST
AGAIN THIS AFTERNOON INTO EARLY THIS EVENING. THE FREEZING LEVEL IS
FORECAST TO REACH 16KFT THIS AFTERNOON.
RECENT HRRR MODEL RUNS ARE FOCUSED ON TWO AREAS FOR CONVECTIVE
INITIATION LATER TODAY: THE SEABREEZE BOUNDARY ALONG THE COAST...AND
THE SC MIDLANDS/PEE DEE REGION. I HAVE INCREASED POPS TO NEAR 60
PERCENT FOR THE FLORENCE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING AS THE BULK OF RECENT MODEL DATA PAINTS THE BEST POTENTIAL
FOR THUNDERSTORMS HERE. FEWER CHANGES WERE NEEDED ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...THE UPPER LONGWAVE PATTERN THRU THIS PERIOD
WILL EXHIBIT A WELL AMPLIFIED TROF AFFECTING THE UNITED STATES
EAST OF THE MISSISSIPPI RIVER. THIS HAS BEEN PLAYED OUT FOR MUCH
OF THIS SUMMER SEASON. AT THE SFC...THE FA WILL HAVE TO DEAL WITH
A COLD FRONTAL PASSAGE DURING WEDNESDAY...ALTHOUGH MODELS HAVE
BEEN TRENDING WITH SLOWER CFP DURING THE PAST FEW RUNS. AS A
RESULT...HAVE INCLUDED CHANCE POPS UP THRU SUNSET WEDNESDAY. THE
DAYS INSOLATION WILL ADD INSTABILITY TO THE LOCAL ATM. A MID-LEVEL
VORT MAX IS PROGGED TO ROUND THE BASE OF THE UPPER LONGWAVE TROF
DURING WED AFTN AND ACROSS THE FA...FURTHER ADDING DYNAMICS AND
UVVS TO THE MIX. SOME OF THESE STORMS COULD END UP BEING STRONG TO
POSSIBLY SEVERE AS DRIER AIR ALOFT AND INCREASING WIND SPEED SHEAR
THRU THE ATM PROFILE. AGAIN NOT LOOKING AT WIDESPREAD
PCPN...SHOULD BE SCATTERED AT BEST. VARIOUS MODEL MOS GUIDANCE
SIMILAR WITH MAX TEMPS WED...RUNNING ATLEAST A CAT ABOVE CLIMO
NORMS.
FOR WED NIGHT THRU THU NIGHT...THE MEAN UPPER LONGWAVE N-S TROF AXIS
TO RESIDE OVERHEAD OR JUST WEST OF THE ILM CWA. THIS POSITIONING
WILL BE IMPORTANT WITH REGARD TO HOW FAR SOUTH AND EAST THE COLD
FRONT PROGRESSES BEFORE STALLING AS IT BECOMES ORIENTED PARALLEL TO
THE UPPER FLOW. FOR NOW...WILL MAINTAIN ITS FINAL POSITIONING WELL
SOUTH AND EAST OF THE ILM CWA DURING THIS PERIOD. AS A
RESULT...DRIER AIR WILL INFILTRATE THE FA. NOT NECESSARILY
COOLER...DUE TO THE ATM HAVING BEEN UNDER OVERCAST SKIES AND OFF AND
ON PCPN FOR THE PAST 3-4 DAYS. WILL ILLUSTRATE NO POPS FOR WED NITE
THRU THU NITE GIVEN THE SUBSIDENCE PREVAILING ACROSS THE FA. STILL
ENOUGH MOISTURE IN THE LOW LEVELS FOR DIURNALLY DRIVEN CU FOR
DAYLIGHT THU. MAX/MIN TEMPS TO RUN ONE TO 2 CAT BELOW NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...THE START OF THIS PERIOD...MODELS CONTINUE
WITH A WELL AMPLIFIED LONGWAVE UPPER TROF AFFECTING THE EASTERN
1/3RD OF THE U.S...WHICH INCLUDES THE ILM CWA. THE MEAN N-S UPPER
TROF AXIS TO LIE NEARLY OVERHEAD. THIS IS IMPORTANT BECAUSE THE
STALLED/STATIONARY SFC FRONT WILL REMAIN JUST FAR ENOUGH EAST AND
SOUTH OF THE FA...AND SO DOES THE PCPN ASSOCIATED WITH IT. FOR
FRI...JUST ENOUGH INSTABILITY AND LOW LEVEL MOISTURE AVBL FOR A
LOW CHANCE POP ALONG THE COASTAL COUNTIES FOR ANY SEA BREEZE
INDUCED SHOWERS OR THUNDERSTORMS.
DURING THE UPCOMING WEEKEND...MODEL CONSENSUS IS FOR THIS LONGWAVE
UPPER TROF TO DE-AMPLIFY AND FLATTEN-SOME. LOOK FOR A BETTER CHANCE
FOR DIURNALLY DRIVEN CONVECTION BY SUNDAY AND ESPECIALLY INTO NEXT
WEEK AS THE MOISTURE AND INSTABILITY RETURN. THE SFC PIEDMONT TROF
TO RETURN AND THE DAILY SEA BREEZE WILL PROVIDE THE FORCING TO AID
THE DIURNALLY DRIVEN CONVECTION. HAVE LEANED TOWARD THE GFS SOLUTION
WITH BERMUDA RIDGING TO POSSIBLY AFFECT THE FA AT THE END OF THE
LONG TERM PERIOD.
MAX/MIN TEMPS TO START OUT SLIGHTLY BELOW CLIMO NORMS FRI...THEN
MODERATE TO NEAR OR SLIGHTLY ABOVE NORMAL DURING THE REMAINDER OF
THE LONG TERM PERIOD.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...THE HRRR MODEL CONTINUES TO TREND THE CONVECTION LATER
IN THE AFTERNOON AND INTO EVENING HOURS. THERE SHOULD ALSO BE SOME
CONVECTION ALONG THE RESULTANT BOUNDARY A BIT EARLIER...HOWEVER MOST
OF THE ACTIVITY WILL BE INLAND FROM THE COASTAL TERMINALS. BRIEF
HEAVY RAIN IS EXPECTED WITH PWATS OVER TWO INCHES NEAR THE COAST.
TONIGHT...CONVECTION WILL FINALLY WIND DOWN AROUND 02-03Z...WITH
PATCHY FOG EXPECTED...MAINLY IN THE AREAS WHERE IT RAINED. WINDS
WILL SHIFT TO THE WEST WEDNESDAY AS A FRONT PUSHES THROUGH THE
REGION. THERE IS A SLIGHT CHANCE FOR SHOWERS IMMEDIATELY ALONG THE
FRONT TOMORROW...CONFIDENCE LOW.
EXTENDED OUTLOOK...VFR THURS THROUGH SAT. CHANCE FOR SHOWERS SUNDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM TUESDAY...THE SEABREEZE HAS FORMED AT THE BEACHES WHERE
VIRTUALLY ALL OBSERVATIONS NOW SHOW A SOUTH WIND. SHOWERS ARE
BEGINNING TO DEVELOP ACROSS SOUTH CAROLINA 10-50 MILES INLAND FROM
THE COAST. UNLESS ONE OR TWO SNEAK ACROSS THE SEABREEZE BOUNDARY IT
APPEARS DRY WEATHER SHOULD PERSIST UNTIL LATE AFTERNOON. PREVIOUS
DISCUSSION FROM 1030 AM FOLLOWS...
WEAK LOW PRESSURE ALONG A FRONT THAT HAD BEEN STALLED ACROSS SOUTH
CAROLINA FOR THE PAST COUPLE OF DAYS IS ON THE MOVE. ACCORDING TO
LATEST WIND DATA THE FRONT ALREADY HAS PUSHED AS FAR NORTH AS
HATTERAS ISLAND. THIS LEAVES A LIGHT SOUTHWESTERLY WIND ACROSS OUR
PORTION OF THE CAROLINAS. INCREASING WIND SPEEDS ARE EXPECTED THIS
AFTERNOON NEARSHORE AS A WEAK TO MODERATE SEABREEZE CIRCULATION
DEVELOPS. WINDS AT THE BEACHES SHOULD INCREASE TO NEAR 12 KNOTS.
A COLD FRONT WILL APPROACH FROM THE WEST LATE TONIGHT. ACCELERATING
WINDS AHEAD OF THIS FEATURE SHOULD PUSH WIND SPEEDS CLOSER TO 15
KNOTS OVERNIGHT...ESPECIALLY AWAY FROM SHORE. SEAS CURRENTLY 2-3
FEET WILL BUILD TO 3-4 FT OVERNIGHT...ESPECIALLY AWAY FROM SHORE.
RADAR AND SATELLITE SHOW CLEAR CONDITIONS ACROSS THE WATERS
CURRENTLY. SCATTERED THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON
ALONG THE SEABREEZE BOUNDARY JUST INLAND FROM THE COAST. ATMOSPHERIC
STEERING FLOW IS FROM THE WEST WHICH WILL TRY TO PUSH THESE STORMS
ACROSS THE SEABREEZE FRONT INTO THE OCEAN. BETTER CHANCES MAY
DEVELOP THIS EVENING AS A LARGE CLUSTER OF STORMS EXPECTED TO
DEVELOP ACROSS SOUTH CAROLINA THIS AFTERNOON RUNS EAST TOWARD THE
COAST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM TUESDAY...AHEAD OF THE COLD FRONT DURING
WEDNESDAY...LOOK FOR A TIGHTENED SFC PG AND A PATTERN THAT YIELDS
SW TO WSW WINDS AROUND 15 KT...OCCASIONALLY UP TO 20 KT. THE CFP
IS SLATED FOR WED AFTN AND EVENING. WILL BE LOOKING AT WINDS
VEERING TO THE NW-NE WED NITE THRU THU WITH SPEEDS AROUND 15 KT
THEN DIMINISHING THU AFTN AND NIGHT AS THE COLD FRONT STALLS TO
THE SOUTH AND THE SFC PG RELAXES. MODELS INDICATE RATHER BROAD
HIGH PRESSURE TO RIDGE IN FROM THE NW WITH WIND DIRECTIONS
BECOMING SOMEWHAT VARIABLE IN DIRECTION BY THU NIGHT. SIGNIFICANT
SEAS WILL PEAK IN THE 3 TO POSSIBLY 5 FOOT RANGE DURING WEDNESDAY
INTO WED EVENING AND MAINLY BE A FUNCTION OF LOCALLY PRODUCED 4 TO
6 SECOND PERIOD WIND DRIVEN WAVES. AFTER THE NE-E SURGE WED NITE
INTO THU...PREDOMINATE WIND DRIVEN SIGNIFICANT SEAS WILL BE ON THE
DECLINE. EVENTUALLY... THE ESE 1-2 FOOT GROUND SWELL WILL BECOME
THE DOMINANT SIG. SEAS DRIVER BY LATE THU NIGHT.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A SOMEWHAT RELAXED SFC PG AND A
DISORGANIZED PRESSURE PATTERN VIA LATEST MODEL RUNS INDICATE THAT
MESOSCALE PROCESSES WILL LIKELY CONTROL WINDS FRI INTO SAT. LOOK
FOR AN ACTIVE SEA BREEZE CIRCULATION BOTH DAYS. OVERALL...WINDS
WILL RUN SE-SSW AROUND 10 KT...10-15 KT NEARSHORE DURING THE DAILY
SEA BREEZE. SIGNIFICANT SEAS VIA WAVEWATCH3 AND LOCALLY PRODUCED
SWAN WILL HOVER AROUND 2 FT AND MAINLY BE A FUNCTION OF AN ESE-SE
1-2 FOOT GROUND SWELL. SIG. SEAS COULD POSSIBLY REACH 3 FT
NEARSHORE DUE TO AN INFLUX OF SHORT PERIOD WIND DRIVEN WAVES
DURING THE HEIGHT OF THE AFTN/EARLY EVNG SEA BREEZE CIRCULATION.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM TUESDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
TONIGHTS HIGH TIDE FOR THE LOWER CAPE FEAR RIVER SIMILAR TO THE
LAST 3 EVENINGS...BUT LIKELY A FEW INCHES LOWER ON THE PEAK WATER
LEVELS. ELEVATED LEVELS WILL BE OBSERVED ALONG THE BANKS OF THE
ICW AS WELL DURING HIGH TIDE LATE TONIGHT. THE LOWER CAPE FEAR
RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING LOCALIZED
AREAS OF DOWNTOWN WILMINGTON. NO COASTAL FLOOD ADVISORIES FOR THE
BEACHES EXPECTED AS ASTRONOMICAL PULLS HAVE ABATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...DL
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1040 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LINGERING TROPICAL MOISTURE ACROSS THE CAROLINAS WILL TRIGGER
SCATTERED TORRENTIAL SHOWERS AND THUNDERSTORMS THROUGH EARLY
WEDNESDAY. A COLD FRONT WILL CROSS THE COAST EARLY ON THURSDAY...
BRINGING A DRYING TREND ALONG WITH COOLER OVERNIGHT TEMPERATURES.
SEASONABLE WEATHER FOR MIDDLE AUGUST IS EXPECTED EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...THIS MORNING`S FORECAST UPDATE FEATURES NO
SIGNIFICANT CHANGES FROM THE PREVIOUS FORECAST. THE STATIONARY FRONT
THAT HAD BEEN STALLED ACROSS SOUTH CAROLINA FOR THE PAST COUPLE OF
DAYS HAS LIFTED NORTHWARD INTO NORTHERN NORTH CAROLINA...ACCOMPANIED
BY A WEAK AREA OF LOW PRESSURE. THIS WILL REMOVE SOME OF THE
LOW-LEVEL FORCING THAT FAVORED WIDESPREAD THUNDERSTORM ACTIVITY OVER
THE PAST FEW DAYS. MORNING LOW STRATUS AND FOG IS BURNING OFF AND
SHOULD HAVE ITS MOISTURE INCORPORATED INTO AN ACTIVE CUMULUS FIELD
THIS AFTERNOON.
THE ATMOSPHERE IS VERY MOIST AND CONDITIONALLY UNSTABLE.
PRECIPITABLE WATER VALUES WERE 2.1 TO 2.2 INCHES ON THE 12Z MHX AND
CHS SOUNDINGS. ASSUMING HIGH TEMPERATURES REACH THE UPPER 80S TO
AROUND 90 LOOK FOR SURFACE-BASED CAPE TO RISE TO NEAR 2000 J/KG WITH
NO CAPPING AND LIFTED INDICES AROUND -5. STEERING FLOW AND SURFACE
WINDS ARE CURRENTLY VERY LIGHT...BUT AS THE DAY PROGRESSES AN
APPROACHING UPPER LEVEL TROUGH AND SURFACE COLD FRONT (NOW ACROSS
THE OHIO VALLEY INTO TENNESSEE) WILL CAUSE AN ACCELERATION OF WINDS
THROUGHOUT THE TROPOSPHERE. THIS WILL NOT APPRECIABLY AFFECT STORM
ORGANIZATION BUT WILL INCREASE STORM MOTION TO 15-20 MPH BY LATE IN
THE DAY. HIGH PRECIPITABLE WATER VALUES PLUS A VERY DEEP WARM CLOUD
LAYER FOR EFFICIENT COALESCENCE-DOMINATED PRECIPITATION PROCESSES TO
OCCUR BOTH ARGUE FOR INCLUSION OF HEAVY RAIN MENTION IN THE FORECAST
AGAIN THIS AFTERNOON INTO EARLY THIS EVENING. THE FREEZING LEVEL IS
FORECAST TO REACH 16KFT THIS AFTERNOON.
RECENT HRRR MODEL RUNS ARE FOCUSED ON TWO AREAS FOR CONVECTIVE
INITIATION LATER TODAY: THE SEABREEZE BOUNDARY ALONG THE COAST...AND
THE SC MIDLANDS/PEE DEE REGION. I HAVE INCREASED POPS TO NEAR 60
PERCENT FOR THE FLORENCE AREA LATE THIS AFTERNOON INTO EARLY THIS
EVENING AS THE BULK OF RECENT MODEL DATA PAINTS THE BEST POTENTIAL
FOR THUNDERSTORMS HERE. FEWER CHANGES WERE NEEDED ELSEWHERE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...THE UPPER LONGWAVE PATTERN THRU THIS PERIOD
WILL EXHIBIT A WELL AMPLIFIED TROF AFFECTING THE UNITED STATES
EAST OF THE MISSISSIPPI RIVER. THIS HAS BEEN PLAYED OUT FOR MUCH
OF THIS SUMMER SEASON. AT THE SFC...THE FA WILL HAVE TO DEAL WITH
A COLD FRONTAL PASSAGE DURING WEDNESDAY...ALTHOUGH MODELS HAVE
BEEN TRENDING WITH SLOWER CFP DURING THE PAST FEW RUNS. AS A
RESULT...HAVE INCLUDED CHANCE POPS UP THRU SUNSET WEDNESDAY. THE
DAYS INSOLATION WILL ADD INSTABILITY TO THE LOCAL ATM. A MID-LEVEL
VORT MAX IS PROGGED TO ROUND THE BASE OF THE UPPER LONGWAVE TROF
DURING WED AFTN AND ACROSS THE FA...FURTHER ADDING DYNAMICS AND
UVVS TO THE MIX. SOME OF THESE STORMS COULD END UP BEING STRONG TO
POSSIBLY SEVERE AS DRIER AIR ALOFT AND INCREASING WIND SPEED SHEAR
THRU THE ATM PROFILE. AGAIN NOT LOOKING AT WIDESPREAD
PCPN...SHOULD BE SCATTERED AT BEST. VARIOUS MODEL MOS GUIDANCE
SIMILAR WITH MAX TEMPS WED...RUNNING ATLEAST A CAT ABOVE CLIMO
NORMS.
FOR WED NIGHT THRU THU NIGHT...THE MEAN UPPER LONGWAVE N-S TROF AXIS
TO RESIDE OVERHEAD OR JUST WEST OF THE ILM CWA. THIS POSITIONING
WILL BE IMPORTANT WITH REGARD TO HOW FAR SOUTH AND EAST THE COLD
FRONT PROGRESSES BEFORE STALLING AS IT BECOMES ORIENTED PARALLEL TO
THE UPPER FLOW. FOR NOW...WILL MAINTAIN ITS FINAL POSITIONING WELL
SOUTH AND EAST OF THE ILM CWA DURING THIS PERIOD. AS A
RESULT...DRIER AIR WILL INFILTRATE THE FA. NOT NECESSARILY
COOLER...DUE TO THE ATM HAVING BEEN UNDER OVERCAST SKIES AND OFF AND
ON PCPN FOR THE PAST 3-4 DAYS. WILL ILLUSTRATE NO POPS FOR WED NITE
THRU THU NITE GIVEN THE SUBSIDENCE PREVAILING ACROSS THE FA. STILL
ENOUGH MOISTURE IN THE LOW LEVELS FOR DIURNALLY DRIVEN CU FOR
DAYLIGHT THU. MAX/MIN TEMPS TO RUN ONE TO 2 CAT BELOW NORMAL.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...THE START OF THIS PERIOD...MODELS CONTINUE
WITH A WELL AMPLIFIED LONGWAVE UPPER TROF AFFECTING THE EASTERN
1/3RD OF THE U.S...WHICH INCLUDES THE ILM CWA. THE MEAN N-S UPPER
TROF AXIS TO LIE NEARLY OVERHEAD. THIS IS IMPORTANT BECAUSE THE
STALLED/STATIONARY SFC FRONT WILL REMAIN JUST FAR ENOUGH EAST AND
SOUTH OF THE FA...AND SO DOES THE PCPN ASSOCIATED WITH IT. FOR
FRI...JUST ENOUGH INSTABILITY AND LOW LEVEL MOISTURE AVBL FOR A
LOW CHANCE POP ALONG THE COASTAL COUNTIES FOR ANY SEA BREEZE
INDUCED SHOWERS OR THUNDERSTORMS.
DURING THE UPCOMING WEEKEND...MODEL CONSENSUS IS FOR THIS LONGWAVE
UPPER TROF TO DE-AMPLIFY AND FLATTEN-SOME. LOOK FOR A BETTER CHANCE
FOR DIURNALLY DRIVEN CONVECTION BY SUNDAY AND ESPECIALLY INTO NEXT
WEEK AS THE MOISTURE AND INSTABILITY RETURN. THE SFC PIEDMONT TROF
TO RETURN AND THE DAILY SEA BREEZE WILL PROVIDE THE FORCING TO AID
THE DIURNALLY DRIVEN CONVECTION. HAVE LEANED TOWARD THE GFS SOLUTION
WITH BERMUDA RIDGING TO POSSIBLY AFFECT THE FA AT THE END OF THE
LONG TERM PERIOD.
MAX/MIN TEMPS TO START OUT SLIGHTLY BELOW CLIMO NORMS FRI...THEN
MODERATE TO NEAR OR SLIGHTLY ABOVE NORMAL DURING THE REMAINDER OF
THE LONG TERM PERIOD.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...DENSE FOG WILL LINGER INLAND WITH PATCHES OF LIFR
STRATUS ALONG THE COAST. LOW PRESSURE WILL REMAIN OVER THE REGION
THROUGH THE AFTERNOON HOURS WITH TROPICAL MOISTURE IN PLACE. SHOULD
SEE A DECENT COVERAGE OF CONVECTION THIS AFTERNOON AS TEMPS RISE
INTO THE MID AND UPPER 80S...WITH THE RESULTANT BOUNDARY A FOCUS FOR
SHOWERS. WILL TWEAK THE TIMING AND COVERAGE OF THE CONVECTION WITH
LATE MORNING UPDATES. WINDS WILL BE MAINLY EASTERLY EARLY...BECOMING
SOUTHERLY IN THE AFTERNOON.
EXTENDED OUTLOOK...ISOLATED TO SCATTERED SHRA/TSRA ALONG WITH TEMPO
MVFR CONDITIONS THROUGH TUESDAY NIGHT. IMPROVING CONDITIONS WED AS A
FRONT MOVES OFFSHORE. VFR THURS THROUGH SAT.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM TUESDAY...WEAK LOW PRESSURE ALONG A FRONT THAT HAD
BEEN STALLED ACROSS SOUTH CAROLINA FOR THE PAST COUPLE OF DAYS IS ON
THE MOVE. ACCORDING TO LATEST WIND DATA THE FRONT ALREADY HAS PUSHED
AS FAR NORTH AS HATTERAS ISLAND. THIS LEAVES A LIGHT SOUTHWESTERLY
WIND ACROSS OUR PORTION OF THE CAROLINAS. INCREASING WIND SPEEDS ARE
EXPECTED THIS AFTERNOON NEARSHORE AS A WEAK TO MODERATE SEABREEZE
CIRCULATION DEVELOPS. WINDS AT THE BEACHES SHOULD INCREASE TO NEAR
12 KNOTS.
A COLD FRONT WILL APPROACH FROM THE WEST LATE TONIGHT. ACCELERATING
WINDS AHEAD OF THIS FEATURE SHOULD PUSH WIND SPEEDS CLOSER TO 15
KNOTS OVERNIGHT...ESPECIALLY AWAY FROM SHORE. SEAS CURRENTLY 2-3
FEET WILL BUILD TO 3-4 FT OVERNIGHT...ESPECIALLY AWAY FROM SHORE.
RADAR AND SATELLITE SHOW CLEAR CONDITIONS ACROSS THE WATERS
CURRENTLY. SCATTERED THUNDERSTORMS SHOULD DEVELOP THIS AFTERNOON
ALONG THE SEABREEZE BOUNDARY JUST INLAND FROM THE COAST. ATMOSPHERIC
STEERING FLOW IS FROM THE WEST WHICH WILL TRY TO PUSH THESE STORMS
ACROSS THE SEABREEZE FRONT INTO THE OCEAN. BETTER CHANCES MAY
DEVELOP THIS EVENING AS A LARGE CLUSTER OF STORMS EXPECTED TO
DEVELOP ACROSS SOUTH CAROLINA THIS AFTERNOON RUNS EAST TOWARD THE
COAST.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 330 AM TUESDAY...AHEAD OF THE COLD FRONT DURING
WEDNESDAY...LOOK FOR A TIGHTENED SFC PG AND A PATTERN THAT YIELDS
SW TO WSW WINDS AROUND 15 KT...OCCASIONALLY UP TO 20 KT. THE CFP
IS SLATED FOR WED AFTN AND EVENING. WILL BE LOOKING AT WINDS
VEERING TO THE NW-NE WED NITE THRU THU WITH SPEEDS AROUND 15 KT
THEN DIMINISHING THU AFTN AND NIGHT AS THE COLD FRONT STALLS TO
THE SOUTH AND THE SFC PG RELAXES. MODELS INDICATE RATHER BROAD
HIGH PRESSURE TO RIDGE IN FROM THE NW WITH WIND DIRECTIONS
BECOMING SOMEWHAT VARIABLE IN DIRECTION BY THU NIGHT. SIGNIFICANT
SEAS WILL PEAK IN THE 3 TO POSSIBLY 5 FOOT RANGE DURING WEDNESDAY
INTO WED EVENING AND MAINLY BE A FUNCTION OF LOCALLY PRODUCED 4 TO
6 SECOND PERIOD WIND DRIVEN WAVES. AFTER THE NE-E SURGE WED NITE
INTO THU...PREDOMINATE WIND DRIVEN SIGNIFICANT SEAS WILL BE ON THE
DECLINE. EVENTUALLY... THE ESE 1-2 FOOT GROUND SWELL WILL BECOME
THE DOMINANT SIG. SEAS DRIVER BY LATE THU NIGHT.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...A SOMEWHAT RELAXED SFC PG AND A
DISORGANIZED PRESSURE PATTERN VIA LATEST MODEL RUNS INDICATE THAT
MESOSCALE PROCESSES WILL LIKELY CONTROL WINDS FRI INTO SAT. LOOK
FOR AN ACTIVE SEA BREEZE CIRCULATION BOTH DAYS. OVERALL...WINDS
WILL RUN SE-SSW AROUND 10 KT...10-15 KT NEARSHORE DURING THE DAILY
SEA BREEZE. SIGNIFICANT SEAS VIA WAVEWATCH3 AND LOCALLY PRODUCED
SWAN WILL HOVER AROUND 2 FT AND MAINLY BE A FUNCTION OF AN ESE-SE
1-2 FOOT GROUND SWELL. SIG. SEAS COULD POSSIBLY REACH 3 FT
NEARSHORE DUE TO AN INFLUX OF SHORT PERIOD WIND DRIVEN WAVES
DURING THE HEIGHT OF THE AFTN/EARLY EVNG SEA BREEZE CIRCULATION.
&&
.TIDES/COASTAL FLOODING...
AS OF 6 AM TUESDAY...STRONG ASTRONOMICAL TIDES WITH THIS WANING
FULL MOON CYCLE WILL REQUIRE ANOTHER COASTAL FLOOD ADVISORY WITH
TONIGHTS HIGH TIDE FOR THE LOWER CAPE FEAR RIVER SIMILAR TO THE
LAST 3 EVENINGS...BUT LIKELY A FEW INCHES LOWER ON THE PEAK WATER
LEVELS. ELEVATED LEVELS WILL BE OBSERVED ALONG THE BANKS OF THE
ICW AS WELL DURING HIGH TIDE LATE TONIGHT. THE LOWER CAPE FEAR
RIVER WILL EXPERIENCE MINOR COASTAL FLOODING INCLUDING LOCALIZED
AREAS OF DOWNTOWN WILMINGTON. NO COASTAL FLOOD ADVISORIES FOR THE
BEACHES EXPECTED AS ASTRONOMICAL PULLS HAVE ABATED.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT
WEDNESDAY FOR NCZ107.
MARINE...NONE.
&&
$$
NEAR TERM...TRA
SHORT TERM...DCH
LONG TERM...DCH
AVIATION...DL
TIDES/COASTAL FLOODING...8
AREA FORECAST DISCUSSION
NWS RALEIGH NC
725 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM TUESDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...
THE COLD FRONT WILL MOVE TOWARD THE COAST WEDNESDAY MORNING...AS
MUCH DRIER AIR OVERSPREADS THE AREA AND PW DROPS BELOW ONE INCH.
FORECAST SOUNDINGS SHOWS A STRENGTHENING SUBSIDENCE INVERSION ALL THE
WAY EAST TO KRWI AND KFAY...SO ANY ADDITIONAL SHOWERS IN THE
VICINITY OF THE FRONT WILL BE CONFINED TO THE COAST. HIGHS WILL
STILL BE IN THE 83-89 RANGE...BUT THE BIGGER CHANGE WILL BE IN
DEWPOINTS AND THEY FALL INTO THE 50S FROM NORTHWEST TO SOUTHEAST
DURING THE AFTERNOON. THIS WILL ALSO LEAD TO COOLER LOWS...60-
65...AS THICKNESSES DIP BELOW 1390M BY THURSDAY MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
LITTLE CHANGE IN OVERALL FORECAST RATIONALE FROM THE PAST COUPLE OF
DAYS. THROUGH DAY 5...DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE
GUIDANCE SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT AND ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING AND
FILLING UPPER LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS. THE
ASSOCIATED ANOMALOUSLY LOW HEIGHTS ALOFT FROM SOUTHEASTERN CANADA TO
THE CAROLINAS WILL RELAX AND PROMOTE GRADUALLY WARMING CONDITIONS
FRI INTO THE WEEKEND. MODEL SPREAD INCREASES FOR DAYS 6-7...MOST
NOTABLY WITH THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO SETTLE
INTO THE MID-UPPER MS VALLEY EARLY NEXT WEEK. DIFFERENCES WITH THE
HANDLING OF THIS FEATURE ARISE SEEMINGLY IN PART DUE TO THE DEGREE
OF DOWNSTREAM RE-DEVELOPMENT OF A NEGATIVE HEIGHT ANOMALY OVER THE
NE CONUS (IF ANY) - WHICH WOULD EFFECTIVELY SLOW THE PROGRESSION OF
THE FLOW AND EMBEDDED SHORTWAVES UPSTREAM. THE 12Z/11TH EC ENSEMBLE
MEAN PROVIDES A REASONABLE COMPROMISE SOLUTION BETWEEN THE 00Z/12TH
DETERMINISTIC ECMWF (OUTLIER) THAT IS MOST AGGRESSIVE WITH THE RE-
DEVELOPMENT OF THE VORTEX OVER THE NE...VERSUS THE PAST COUPLE OF
RUNS OF THE GFS THAT DEPICT NO RE-DEVELOPMENT WHATSOEVER.
THU THROUGH SUN: A LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE MID
MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A REINFORCING
COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS THE OH AND
TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC TROUGHING
IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW ALOFT AND
ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE CENTER OF
THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH SAT. MOISTURE...AT THE SFC AND THROUGH A DEEP
LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE DRYNESS
WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND PRECIPITABLE
WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY SLOWLY
INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-INDUCED
CONVECTION...THROUGH THE WEEKEND. WILL INTRODUCE A SLIGHT CHANCE OF
A DIURNALLY-DRIVEN AFTERNOON STORM OVER THE SOUTHERN COASTAL PLAIN
TO ACCOUNT FOR SOME SEA-BREEZE CONVECTION/OUTFLOW PROPAGATING AWAY
FROM COASTAL AREAS.
OTHERWISE...H85 TEMPS INITIALLY IN THE 14-16C RANGE...SHOULD SUPPORT
TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW NORMAL THROUGH
FRI...WITH WARMING TO AROUND OR SLIGHTLY ABOVE NORMAL VALUES THROUGH
EARLY NEXT WEEK. THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE
TROUGH SETTLING ACROSS THE MS VALLEY EARLY NEXT WEEK WOULD FOCUS
ABOVE NORMAL PRECIPITATION CHANCES WEST OF THE APPALACHIANS/OVER THE
OH VALLEY THROUGH DAY 7.
&&
.AVIATION /12Z MONDAY THROUGH SATURDAY/...
AS OF 725 AM TUESDAY...
LIFR/IFR STRATUS IS CURRENTLY OBSERVED ACROSS NEARLY ALL OF CENTRAL
NC...EXCEPT FOR THE NORTHERN COASTAL PLAIN...WHERE KRWI REMAINS VFR.
SCATTERING OF THE LOW CLOUDS WILL OCCUR DURING THE MID-MORNING HOURS
AS A WARM FRONT LIFTS THROUGH THE AREA...FIRST AT KFAY AND KRWI BY
14-15Z. STRATUS WILL LIKELY HAND AROUND LONGER AT
KGSO/KINT...POSSIBLY UNTIL AROUND 16-17Z. WITH AT LEAST PARTIAL
CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY AROUND MIDNIGHT. A FEW
SHOWERS MAY BE POSSIBLE WITH THE FRONT BETWEEN 06Z AND 12Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM TUESDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 325 AM TUESDAY...
THE COLD FRONT WILL MOVE TOWARD THE COAST WEDNESDAY MORNING...AS
MUCH DRIER AIR OVERSPREADS THE AREA AND PW DROPS BELOW ONE INCH.
FORECAST SOUNDINGS SHOWS A STRENGTHENING SUBSIDENCE INVERSION ALL THE
WAY EAST TO KRWI AND KFAY...SO ANY ADDITIONAL SHOWERS IN THE
VICINITY OF THE FRONT WILL BE CONFINED TO THE COAST. HIGHS WILL
STILL BE IN THE 83-89 RANGE...BUT THE BIGGER CHANGE WILL BE IN
DEWPOINTS AND THEY FALL INTO THE 50S FROM NORTHWEST TO SOUTHEAST
DURING THE AFTERNOON. THIS WILL ALSO LEAD TO COOLER LOWS...60-
65...AS THICKNESSES DIP BELOW 1390M BY THURSDAY MORNING.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
LITTLE CHANGE IN OVERALL FORECAST RATIONALE FROM THE PAST COUPLE OF
DAYS. THROUGH DAY 5...DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE
GUIDANCE SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT AND ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING AND
FILLING UPPER LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS. THE
ASSOCIATED ANOMALOUSLY LOW HEIGHTS ALOFT FROM SOUTHEASTERN CANADA TO
THE CAROLINAS WILL RELAX AND PROMOTE GRADUALLY WARMING CONDITIONS
FRI INTO THE WEEKEND. MODEL SPREAD INCREASES FOR DAYS 6-7...MOST
NOTABLY WITH THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO SETTLE
INTO THE MID-UPPER MS VALLEY EARLY NEXT WEEK. DIFFERENCES WITH THE
HANDLING OF THIS FEATURE ARISE SEEMINGLY IN PART DUE TO THE DEGREE
OF DOWNSTREAM RE-DEVELOPMENT OF A NEGATIVE HEIGHT ANOMALY OVER THE
NE CONUS (IF ANY) - WHICH WOULD EFFECTIVELY SLOW THE PROGRESSION OF
THE FLOW AND EMBEDDED SHORTWAVES UPSTREAM. THE 12Z/11TH EC ENSEMBLE
MEAN PROVIDES A REASONABLE COMPROMISE SOLUTION BETWEEN THE 00Z/12TH
DETERMINISTIC ECMWF (OUTLIER) THAT IS MOST AGGRESSIVE WITH THE RE-
DEVELOPMENT OF THE VORTEX OVER THE NE...VERSUS THE PAST COUPLE OF
RUNS OF THE GFS THAT DEPICT NO RE-DEVELOPMENT WHATSOEVER.
THU THROUGH SUN: A LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE MID
MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A REINFORCING
COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS THE OH AND
TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC TROUGHING
IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW ALOFT AND
ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE CENTER OF
THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH SAT. MOISTURE...AT THE SFC AND THROUGH A DEEP
LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE DRYNESS
WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND PRECIPITABLE
WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY SLOWLY
INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-INDUCED
CONVECTION...THROUGH THE WEEKEND. WILL INTRODUCE A SLIGHT CHANCE OF
A DIURNALLY-DRIVEN AFTERNOON STORM OVER THE SOUTHERN COASTAL PLAIN
TO ACCOUNT FOR SOME SEA-BREEZE CONVECTION/OUTFLOW PROPAGATING AWAY
FROM COASTAL AREAS.
OTHERWISE...H85 TEMPS INITIALLY IN THE 14-16C RANGE...SHOULD SUPPORT
TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW NORMAL THROUGH
FRI...WITH WARMING TO AROUND OR SLIGHTLY ABOVE NORMAL VALUES THROUGH
EARLY NEXT WEEK. THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE
TROUGH SETTLING ACROSS THE MS VALLEY EARLY NEXT WEEK WOULD FOCUS
ABOVE NORMAL PRECIPITATION CHANCES WEST OF THE APPALACHIANS/OVER THE
OH VALLEY THROUGH DAY 7.
&&
.AVIATION /06Z MONDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...
A FEW AREAS OF RAIN CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE
PIEDMONT...THOUGH GENERALLY CLEAR OF THE TAF SITES. MAY SEE ANOTHER
ROUND OF LIGHT TO MODERATE RAIN AT KRDU BY 08Z.
MEANWHILE...CEILINGS ARE ALREADY AT LIFR/IFR LEVELS AT
KINT/KGSO...AND WILL CONTINUE TO LOWER AT KRDU/KFAY/KRWI BY 09Z.
CONFIDENCE IN IFR CONDITIONS IS LOWEST AT KRWI HOWEVER...SO WILL
JUST KEEP A TEMPO FOR NOW. SCATTERING OF LOW CLOUDS WILL OCCUR
DURING THE MID-MORNING HOURS AS A WARM FRONT LIFTS THROUGH THE
AREA...FIRST AT KFAY AND KRWI. STRATUS WILL LIKELY HAND AROUND
LONGER AT KGSO/KINT...POSSIBLY UNTIL AROUND 16Z. WITH AT LEAST
PARTIAL CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY THE END OF THE CURRENT TAF
PERIOD. ADDITIONAL SHOWERS/STORMS MAY BE POSSIBLE WITH THE FRONT
AFTER 06Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...BLS
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM MONDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
UPDATED SHORTLY...
&&
.LONG TERM THURSDAY THROUGH MONDAY/...
AS OF 315 AM TUESDAY...
LITTLE CHANGE IN OVERALL FORECAST RATIONALE FROM THE PAST COUPLE OF
DAYS. THROUGH DAY 5...DETERMINISTIC AND ENSEMBLE MEAN MEDIUM RANGE
GUIDANCE SOLUTIONS ARE IN RELATIVELY GOOD AGREEMENT AND ARE
CHARACTERIZED BY A RELATIVELY HIGH AMPLITUDE RIDGE OVER INTERIOR
WESTERN NOAM...FLANKED BY A COUPLE OF SLOWLY ENE-MIGRATING AND
FILLING UPPER LOWS ACROSS THE NW AND NE CORNERS OF THE CONUS. THE
ASSOCIATED ANOMALOUSLY LOW HEIGHTS ALOFT FROM SOUTHEASTERN CANADA TO
THE CAROLINAS WILL RELAX AND PROMOTE GRADUALLY WARMING CONDITIONS
FRI INTO THE WEEKEND. MODEL SPREAD INCREASES FOR DAYS 6-7...MOST
NOTABLY WITH THE HANDLING OF A SHORTWAVE TROUGH FORECAST TO SETTLE
INTO THE MID-UPPER MS VALLEY EARLY NEXT WEEK. DIFFERENCES WITH THE
HANDLING OF THIS FEATURE ARISE SEEMINGLY IN PART DUE TO THE DEGREE
OF DOWNSTREAM RE-DEVELOPMENT OF A NEGATIVE HEIGHT ANOMALY OVER THE
NE CONUS (IF ANY) - WHICH WOULD EFFECTIVELY SLOW THE PROGRESSION OF
THE FLOW AND EMBEDDED SHORTWAVES UPSTREAM. THE 12Z/11TH EC ENSEMBLE
MEAN PROVIDES A REASONABLE COMPROMISE SOLUTION BETWEEN THE 00Z/12TH
DETERMINISTIC ECMWF (OUTLIER) THAT IS MOST AGGRESSIVE WITH THE RE-
DEVELOPMENT OF THE VORTEX OVER THE NE...VERSUS THE PAST COUPLE OF
RUNS OF THE GFS THAT DEPICT NO RE-DEVELOPMENT WHATSOEVER.
THU THROUGH SUN: A LEAD CANADIAN HIGH WILL BUILD SOUTH INTO THE MID
MS VALLEY THU...AND AWAIT UPSTREAM REINFORCEMENT FROM A REINFORCING
COLD FRONT/CANADIAN HIGH FORECAST TO SETTLE SOUTH ACROSS THE OH AND
TN VALLEYS THROUGH FRI. THOUGH MASKED BY WEAK LEESIDE SFC TROUGHING
IN THE LEE OF THE APPALACHIANS...BENEATH CYCLONIC FLOW ALOFT AND
ASSOCIATED LOW-MID LEVEL WESTERLY (DOWNSLOPE) FLOW...THE CENTER OF
THE CANADIAN HIGH WILL BUILD INTO AND ACROSS THE CENTRAL
APPALACHIANS THROUGH SAT. MOISTURE...AT THE SFC AND THROUGH A DEEP
LAYER...WILL CONSEQUENTLY BE LIMITED. IN FACT...THE RELATIVE DRYNESS
WILL BE HIGHLIGHTED BY SFC DEWPOINTS IN THE 50S AND PRECIPITABLE
WATER VALUES AOB ONE INCH ON THU...BOTH OF WHICH ONLY SLOWLY
INCREASE AND RESULT IN PRIMARILY SEA BREEZE AND MOUNTAIN-INDUCED
CONVECTION...THROUGH THE WEEKEND. WILL INTRODUCE A SLIGHT CHANCE OF
A DIURNALLY-DRIVEN AFTERNOON STORM OVER THE SOUTHERN COASTAL PLAIN
TO ACCOUNT FOR SOME SEA-BREEZE CONVECTION/OUTFLOW PROPAGATING AWAY
FROM COASTAL AREAS.
OTHERWISE...H85 TEMPS INITIALLY IN THE 14-16C RANGE...SHOULD SUPPORT
TEMPERATURES PERHAPS NEAR TO SLIGHTLY BELOW NORMAL THROUGH
FRI...WITH WARMING TO AROUND OR SLIGHTLY ABOVE NORMAL VALUES THROUGH
EARLY NEXT WEEK. THE EVOLUTION OF THE AFOREMENTIONED SHORTWAVE
TROUGH SETTLING ACROSS THE MS VALLEY EARLY NEXT WEEK WOULD FOCUS
ABOVE NORMAL PRECIPITATION CHANCES WEST OF THE APPALACHIANS/OVER THE
OH VALLEY THROUGH DAY 7.
&&
.AVIATION /06Z MONDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...
A FEW AREAS OF RAIN CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE
PIEDMONT...THOUGH GENERALLY CLEAR OF THE TAF SITES. MAY SEE ANOTHER
ROUND OF LIGHT TO MODERATE RAIN AT KRDU BY 08Z.
MEANWHILE...CEILINGS ARE ALREADY AT LIFR/IFR LEVELS AT
KINT/KGSO...AND WILL CONTINUE TO LOWER AT KRDU/KFAY/KRWI BY 09Z.
CONFIDENCE IN IFR CONDITIONS IS LOWEST AT KRWI HOWEVER...SO WILL
JUST KEEP A TEMPO FOR NOW. SCATTERING OF LOW CLOUDS WILL OCCUR
DURING THE MID-MORNING HOURS AS A WARM FRONT LIFTS THROUGH THE
AREA...FIRST AT KFAY AND KRWI. STRATUS WILL LIKELY HAND AROUND
LONGER AT KGSO/KINT...POSSIBLY UNTIL AROUND 16Z. WITH AT LEAST
PARTIAL CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY THE END OF THE CURRENT TAF
PERIOD. ADDITIONAL SHOWERS/STORMS MAY BE POSSIBLE WITH THE FRONT
AFTER 06Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...DJF
LONG TERM...MWS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 AM EDT TUE AUG 12 2014
.SYNOPSIS...A WARM FRONT WILL LIFT NORTH THROUGH THE AREA THIS
MORNING. A COLD FRONT WILL CROSS THE AREA TONIGHT AND EARLY
WEDNESDAY MORNING...FOLLOWED BY HIGH PRESSURE AND DRIER WEATHER FOR
THE BALANCE OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM MONDAY...
A FEW PATCHES OF LIGHT RAIN ARE CURRENTLY MOVING NORTHEAST THROUGH
THE PIEDMONT...THOUGH THE COVERAGE HAS DECREASED SIGNIFICANTLY SINCE
MIDNIGHT. HIGH PRESSURE OFF THE NEW ENGLAND COAST CONTINUES TO LOSE
ITS INFLUENCE...THOUGH A WEAK LOW OFF THE WILMINGTON COAST IS
HELPING TO MAINTAIN A MORE EASTERLY FLOW OVER CENTRAL NC. RAP
ISENTROPIC ANALYSIS SHOWS THE DEEPER ISENTROPIC LIFT MOVING NORTH
INTO VA...WITH SHALLOW SOUTHEASTERLY FLOW AND UPSLOPE FLOW DRIVING
THE SHOWERS OVER WESTERN NC. RAP VORT FIELDS AND WATER VAPOR
IMAGERY SUGGEST THERE MAY BE A WEAK DISTURBANCE OVER NORTHERN
GEORGIA/UPSTATE SC THAT MAY BE AIDING THESE SHOWERS. THE BULK OF
THIS PRECIP SHOULD STAY JUST TO THE WEST OF THE YADKIN RIVER THROUGH
SUNRISE...BUT SOME LIGHT RAIN WILL LIKELY KEEP THE LINGERING CAD
AIRMASS IN PLACE DESPITE THE LACK OF A STRONG STABLE LAYER OVER THE
WESTERN PIEDMONT...PER 00Z KGSO AND RAP SOUNDINGS.
MEANWHILE...THE FRONTAL ZONE WILL MOVE NORTH THROUGH THE AREA THIS
MORNING....ESPECIALLY AS MIXING INCREASES AND SOME PARTIAL BREAKS IN
CLOUD COVER DEVELOP OVER THE COASTAL PLAIN. AS TEMPS RISE INTO THE
MID TO UPPER 80S...DEWPOINTS IN THE LOWER 70S AND PW AROUND 2 INCHES
WILL LEAD TO MLCAPE OF AT LEAST 1000-1500 J/KG EAST OF THE TRIAD.
THE DEGREE OF DESTABILIZATION IF A LITTLE MORE UNCERTAIN OVER THE
NORTHWEST PIEDMONT...BUT EVEN HIGHER RES GUIDANCE SHOWS THE TRIAD
MIXING OUT BY AROUND NOON. DEEP LAYER SHEAR ISNT OVERLY IMPRESSIVE
WELL OUT AHEAD OF THE UPPER TROUGH AND ASSOCIATED COLD FRONT...WITH
AROUND 25-30KT OVER WESTERN NC...WHICH MAY BE DISPLACED FROM THE
STRONGEST INSTABILITY. THUS...WITH MAINLY CONFLUENT PRE-FRONTAL
FLOW AS THE FORCING THIS AFTERNOON ...THE COVERAGE OF STRONGER
STORMS IS STILL A LITTLE UNCERTAIN. HEAVY RAIN...EXACERBATED BY
RECENT RAINFALL OF 3-5 INCHES IN SOME AREAS...AND STRONG WIND GUSTS
WILL BE THE MAIN THREAT FROM ANY STRONGER CLUSTERS OF STORMS.
AFTERNOON HIGHS SHOULD RANGE FROM THE LOWER 80S NORTHWEST TO UPPER
80S SOUTHEAST.
THE UPPER TROUGH AND ASSOCIATED MODEST HEIGHT FALLS (FOR AUGUST) AND
DCVA WILL ENCROACH ON THE AREA LATE THIS EVENING AND
OVERNIGHT...WITH HE ATTENDANT COLD FRONT PROGGED TO CROSS THE AREA
AFTER MIDNIGHT. FORECAST SOUNDINGS SHOW SOME INSTABILITY OVERNIGHT
AHEAD OF THE FRONT...AND GIVEN THE UPPER FORCING...IT IS PLAUSIBLE
THAT THERE COULD BE ANOTHER BAND OF SHOWERS AND ISOLATED THUNDER
STORMS WITH THE COLD FRONT. DUE TO THE DRYING ALOFT...NOT QUITE
CONFIDENT ENOUGH FOR A CHANCE POP OVERNIGHT...BUT WILL SHOW A
SECONDARY SLIGHT CHANCE AREA WITH THE COLD FRONT. OVERNIGHT LOWS
WILL STILL BE MUGGY IN THE UPPER 60S TO LOWER 70S.
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...
UPDATED SHORTLY...
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
A TRANQUIL WEATHER PATTERN EXPECTED IN THE LONG TERM. TEMPERATURES
WILL REMAIN NEAR OR BELOW NORMAL.
A L/W TROUGH ANCHORED BY AN UPPER LEVEL LOW OVER ONTARIO/QUEBEC WILL
EXTEND SOUTHWARD INTO THE CAROLINAS THROUGH FRIDAY. THE LEAD COLD
FRONT ASSOCIATED WITH THE TROUGH WILL EXIT OUR COASTAL PLAIN
COUNTIES WEDNESDAY MORNING. MODEL TREND HAS LEANED TOWARD A SLIGHTLY
FASTER EAST PROGRESSION. THUS HAVE TRIMMED THE BACKSIDE OF THE
SLIGHT POPS...KEEPING THE 20 PERCENT POPS CONFINED TO LOCATIONS
ALONG AND EAST OF I-95 AT 6 AM...WITH NEGLIGIBLE POPS BY 10 AM.
WESTERLY LOW LEVEL FLOW IN THE WAKE OF THE FRONT WILL AID TO
DIMINISH/DISSIPATE CLOUD COVERAGE IN THE MORNING...LEADING TO MOSTLY
SUNNY SKIES AREAWIDE BY EARLY AFTERNOON. IT SHOULD BE NOTICEABLY
LESS HUMID ACROSS MICH OF THE PIEDMONT BY EARLY-MID AFTERNOON...AND
INTO THE SANDHILLS AND COASTAL PLAIN LATE IN THE DAY. INITIAL SURGE
OF LOW LEVEL CAA WILL BE NEGATED SOMEWHAT BY DOWNSLOPE COMPONENT OF
LOW LEVEL FLOW AND MID-AUGUST SUN. MAX TEMPS IN THE MID 80S NW TO
UPPER 80S/AROUND 90 SE.
SOME DOUBT AS TO WHETHER NEAR SURFACE WINDS WILL BE ABLE TO DECOUPLE
AS A SECONDARY SFC FRONT WILL APPROACH FROM THE W-NW LATE WEDNESDAY
NIGHT-EARLY THURSDAY. IF ATMOSPHERE REMAINS WELL MIXED...MOST PLACES
SHOULD SEE MIN TEMPS NO LOWER THAN 60-65 DEGREES (NW-SE). IF WINDS
DECOUPLE...NORMALLY COLDER LOCATIONS MY DIP BELOW 60.
A CANADIAN HIGH PRESSURE SYSTEM AT THE SURFACE WILL BE CENTERED OVER
THE LOWER OH VALLEY AND TN VALLEY THURSDAY AND FRIDAY. THIS WEATHER
SYSTEM WILL MAINTAIN DRY CONDITIONS WITH TEMPS GENERALLY A FEW
DEGREES SHY OF NORMAL. THICKNESSES SUPPORT MAX TEMPS IN THE LOW-MID
80S THURSDAY...AND SOLIDLY IN THE MID 80S FRIDAY. BETTER CHANCE FOR
THE NEAR SURFACE WINDS TO DECOUPLE THURSDAY NIGHT. IF SKIES REMAIN
CLEAR...SHOULD SEE MIN TEMPS IN THE UPPER 50S-LOWER 60S. AIR MASS
MODIFICATION FRIDAY NIGHT SUGGEST MIN TEMPS IN THE LOW-MID 60S.
SURFACE HIGH PRESSURE WILL SETTLE OVERHEAD SATURDAY THEN SLOWLY
WEAKEN AS L/W TROUGH WEAKENS AND LIFTS NWD. THIS WILL ALLOW A WEAK
RETURN OF LOW LEVEL MOISTURE BY LATE SATURDAY AND MORE SO SUNDAY
INTO MONDAY. THIS WILL LEAD TO MIXTURE OF SUN/CLOUDS BUT ANY
CONVECTIVE ACTIVITY WILL BE ISOLATED AND CONFINED TO NEAR THE
SEABREEZE...AND EXITING OFF THE HIGHER TERRAIN OF WESTERN NC.
THREAT APPEARS TOO LOW TO MENTION A SLIGHT CHANCE POP ON SUNDAY BUT
ENOUGH MOISTURE/DESTABILIZATION SHOULD EXISTS BY MONDAY FOR SLIGHT
CHANCE IN VICINITY OF THE OUR SOUTHERN AND WESTERN COUNTIES.
AIR MASS WILL CONTINUE TO MODIFY WITH TEMPS RETURNING TO NEAR NORMAL
LEVELS SATURDAY THROUGH MONDAY.
&&
.AVIATION /06Z MONDAY THROUGH SATURDAY/...
AS OF 130 AM TUESDAY...
A FEW AREAS OF RAIN CONTINUE TO MOVE SLOWLY NORTHEAST ACROSS THE
PIEDMONT...THOUGH GENERALLY CLEAR OF THE TAF SITES. MAY SEE ANOTHER
ROUND OF LIGHT TO MODERATE RAIN AT KRDU BY 08Z.
MEANWHILE...CEILINGS ARE ALREADY AT LIFR/IFR LEVELS AT
KINT/KGSO...AND WILL CONTINUE TO LOWER AT KRDU/KFAY/KRWI BY 09Z.
CONFIDENCE IN IFR CONDITIONS IS LOWEST AT KRWI HOWEVER...SO WILL
JUST KEEP A TEMPO FOR NOW. SCATTERING OF LOW CLOUDS WILL OCCUR
DURING THE MID-MORNING HOURS AS A WARM FRONT LIFTS THROUGH THE
AREA...FIRST AT KFAY AND KRWI. STRATUS WILL LIKELY HAND AROUND
LONGER AT KGSO/KINT...POSSIBLY UNTIL AROUND 16Z. WITH AT LEAST
PARTIAL CLEARING...HEATING AND DESTABILIZATION WILL SUPPORT SCATTERED
SHOWERS AND STORMS DURING THE AFTERNOON. CONFIDENCE IN TIMING OF
IMPACT AT TERMINALS IS TOO LOW FOR MENTION OF THUNDER IN TAFS...BUT
PROBABILITIES ARE GREATER AT KRDU/KFAY/KRWI. EXPECT AT LEAST MFR
CEILINGS IN THE TRIAD...IF NOT EVENTUALLY VFR EVERYWHERE DURING THE
AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE WEST DURING THE
EVENING...NEARING KGSO AND KINT BY THE END OF THE CURRENT TAF
PERIOD. ADDITIONAL SHOWERS/STORMS MAY BE POSSIBLE WITH THE FRONT
AFTER 06Z.
OUTLOOK...ONCE THE COLD FRONT CLEARS THE AREA WEDNESDAY
MORNING...VFR CONDITIONS ARE EXPECTED THROUGH THE END OF THE WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLS
NEAR TERM...BLS
SHORT TERM...DJF
LONG TERM...WSS
AVIATION...BLS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
156 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT AND UPPER LEVEL TROUGH WILL CROSS THE REGION TODAY.
HIGH PRESSURE WILL BUILD IN THE UPPER MIDWEST ON WEDNESDAY AND THEN
SETTLE OVER THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS PUSHING EAST ACROSS WESTERN OHIO THIS MORNING AND A
NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED JUST AHEAD
OF IT ACROSS CENTRAL OHIO. AS WE PROGRESS INTO THIS AFTERNOON...THE
BETTER INSTABILITY AND SHEAR WILL BE JUST OFF TO OUR EAST. THE
LATEST HRRR SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT SITUATION...WITH
THE CURRENT LINE OF STORMS INTENSIFYING AS IT PUSHES EAST OF OUR
AREA INTO THE MORE FAVORABLE AIRMASS LATER THIS MORNING INTO
EARLY AFTERNOON. MEANWHILE...EXPECT SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS TO SPREAD BACK IN FROM THE NORTHWEST
THROUGH THE AFTERNOON HOURS AS THE UPPER LEVEL TROUGH AXIS PIVOTS
INTO THE AREA. THIS WILL LIKELY BE DIURNALLY ENHANCED SO EXPECT
HIGHEST POPS WITH THIS ACROSS OUR NORTHWEST...DECREASING OFF TO
THE SOUTHEAST THROUGH LATE AFTERNOON/EARLY EVENING AS WE START TO
LOSE THE DAYTIME HEATING. EXPECT HIGHS TODAY RANGING FROM THE LOW
TO MID 70S ACROSS THE NORTHWEST TO THE UPPER 70S/NEAR 80 IN THE
FAR SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ANY SEMBLANCE OF SHOWERS SHOULD BE WELL EAST OF THE CWA BY
NIGHTFALL. WNW WINDS AT THE SURFACE WITH HIGH PRESSURE BUILDING IN
THE MIDWEST WILL HELP DRIER AIR TO BE PULLED INTO THE OHIO VALLEY.
NAM AND CANADIAN MODEL ARE SHOWING A POSSIBILITY OF A SPRINKLE
OVER THE REGION IN THE PREDAWN HOURS WED MORNING. IF THIS WERE TO
OCCUR...IT IS PURELY FROM THE COLD POOL OF AIR ALOFT. ATTM...I DO
NOT SEE ENOUGH MOISTURE TO ALLOW THE COLD POOL TO WRING OUT A
SHOWER AND HAVE LEFT THE FORECAST DRY.
ON WEDNESDAY...NORTHWEST WINDS WILL KEEP THE COLD AIR OVER THE
REGION WITH HIGHS STAYING IN THE LOW TO MID 70S. A WEAK BOUNDARY
WILL LINGER NORTH OF KY AND THE REAL COLD PUSH ON NORTHERLY WINDS
WILL POSSIBLY SQUEEZE OUT A SHOWER WNW TO ESE OF METRO CINCY ON
THURSDAY AFTERNOON...SLOWLY PUSHING SOUTH INTO KY BY EVENING. THE
CENTER OF THE HIGH WILL SETTLE OVER THE CWA BY FRIDAY MORNING AND
LOWS THURSDAY NIGHT WILL DROP DOWN INTO THE LOWER 50S ACROSS THE
AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
NORTHWEST FLOW ALOFT AT THE BEGINNING OF THE PERIOD WILL FLATTEN AND
BECOME MORE ZONAL OVER THE WEEKEND. 12Z MODELS ARE IN REASONABLE
AGREEMENT THAT A SHORT WAVE WILL PUSH INTO THE REGION ON MONDAY. AT
THE SURFACE HIGH PRESSURE WILL DOMINATE LATE IN THE WEEK BEFORE
SLIDING OFF TO THE SOUTHEAST DURING THE WEEKEND. CANNOT COMPLETELY
RULE OUT SOME STORMS ACROSS THE NORTHERN COUNTIES OVER THE WEEKEND
ON THE SOUTHERN FRINGE OF A MORE ACTIVE CONVECTIVE CORRIDOR ACROSS
THE GREAT LAKES. BUT BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ARE
EXPECTED ON MONDAY. TEMPERATURES EARLY IN THE PERIOD WILL BE BELOW
NORMAL BUT THEN WARM TO ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
COLD FRONT AND ITS ASSOCIATED LINE OF THUNDERSTORMS HAS PUSHED
EAST OF THE EASTERN TAF SITES WITH DRY SLOT NOW WORKING ACROSS
MUCH OF THE AREA. MVFR CLOUDS JUST OFF TO OUR NORTHWEST SHOULD
PIVOT BACK IN ACROSS THE AREA THROUGH THE REMAINDER OF THE
AFTERNOON AS THE UPPER LEVEL TROUGH AXIS APPROACHES. THIS COULD
ALSO LEAD TO SOME SCATTERED SHOWER ACTIVITY ON INTO EARLY EVENING
AND WILL COVER WITH A VCSH. MODELS ARE HANGING ON TO A GOOD DEAL OF
LOW LEVEL MOISTURE THROUGH THE OVERNIGHT SO EXPECT IFR CIGS LATER
TONIGHT ALONG WITH SOME MVFR TO IFR VSBY RESTRICTIONS. LOW CIGS
WILL THEN LINGER INTO THE MORNING HOURS BEFORE GRADUALLY LIFTING
TOWARD THE END OF THE TAF PERIOD.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
926 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A COLD FRONT AND UPPER LEVEL TROUGH WILL CROSS THE REGION TODAY.
HIGH PRESSURE WILL BUILD IN THE UPPER MIDWEST ON WEDNESDAY AND THEN
SETTLE OVER THE OHIO VALLEY THURSDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT IS PUSHING EAST ACROSS WESTERN OHIO THIS MORNING AND A
NARROW LINE OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED JUST AHEAD
OF IT ACROSS CENTRAL OHIO. AS WE PROGRESS INTO THIS AFTERNOON...THE
BETTER INSTABILITY AND SHEAR WILL BE JUST OFF TO OUR EAST. THE
LATEST HRRR SEEMS TO HAVE A GOOD HANDLE ON THE CURRENT SITUATION...WITH
THE CURRENT LINE OF STORMS INTENSIFYING AS IT PUSHES EAST OF OUR
AREA INTO THE MORE FAVORABLE AIRMASS LATER THIS MORNING INTO
EARLY AFTERNOON. MEANWHILE...EXPECT SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS TO SPREAD BACK IN FROM THE NORTHWEST
THROUGH THE AFTERNOON HOURS AS THE UPPER LEVEL TROUGH AXIS PIVOTS
INTO THE AREA. THIS WILL LIKELY BE DIURNALLY ENHANCED SO EXPECT
HIGHEST POPS WITH THIS ACROSS OUR NORTHWEST...DECREASING OFF TO
THE SOUTHEAST THROUGH LATE AFTERNOON/EARLY EVENING AS WE START TO
LOSE THE DAYTIME HEATING. EXPECT HIGHS TODAY RANGING FROM THE LOW
TO MID 70S ACROSS THE NORTHWEST TO THE UPPER 70S/NEAR 80 IN THE
FAR SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ANY SEMBLANCE OF SHOWERS SHOULD BE WELL EAST OF THE CWA BY
NIGHTFALL. WNW WINDS AT THE SURFACE WITH HIGH PRESSURE BUILDING IN
THE MIDWEST WILL HELP DRIER AIR TO BE PULLED INTO THE OHIO VALLEY.
NAM AND CANADIAN MODEL ARE SHOWING A POSSIBILITY OF A SPRINKLE
OVER THE REGION IN THE PREDAWN HOURS WED MORNING. IF THIS WERE TO
OCCUR...IT IS PURELY FROM THE COLD POOL OF AIR ALOFT. ATTM...I DO
NOT SEE ENOUGH MOISTURE TO ALLOW THE COLD POOL TO WRING OUT A
SHOWER AND HAVE LEFT THE FORECAST DRY.
ON WEDNESDAY...NORTHWEST WINDS WILL KEEP THE COLD AIR OVER THE
REGION WITH HIGHS STAYING IN THE LOW TO MID 70S. A WEAK BOUNDARY
WILL LINGER NORTH OF KY AND THE REAL COLD PUSH ON NORTHERLY WINDS
WILL POSSIBLY SQUEEZE OUT A SHOWER WNW TO ESE OF METRO CINCY ON
THURSDAY AFTERNOON...SLOWLY PUSHING SOUTH INTO KY BY EVENING. THE
CENTER OF THE HIGH WILL SETTLE OVER THE CWA BY FRIDAY MORNING AND
LOWS THURSDAY NIGHT WILL DROP DOWN INTO THE LOWER 50S ACROSS THE
AREA.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
NORTHWEST FLOW ALOFT AT THE BEGINNING OF THE PERIOD WILL FLATTEN AND
BECOME MORE ZONAL OVER THE WEEKEND. 12Z MODELS ARE IN REASONABLE
AGREEMENT THAT A SHORT WAVE WILL PUSH INTO THE REGION ON MONDAY. AT
THE SURFACE HIGH PRESSURE WILL DOMINATE LATE IN THE WEEK BEFORE
SLIDING OFF TO THE SOUTHEAST DURING THE WEEKEND. CANNOT COMPLETELY
RULE OUT SOME STORMS ACROSS THE NORTHERN COUNTIES OVER THE WEEKEND
ON THE SOUTHERN FRINGE OF A MORE ACTIVE CONVECTIVE CORRIDOR ACROSS
THE GREAT LAKES. BUT BETTER CHANCE OF SHOWERS AND THUNDERSTORMS ARE
EXPECTED ON MONDAY. TEMPERATURES EARLY IN THE PERIOD WILL BE BELOW
NORMAL BUT THEN WARM TO ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
IFR STRATUS DEVELOPED ACROSS THE ERN TAFS THIS MORNING...ALONG
WITH MVFR FOG AT MOST LOCATIONS. NOW A SFC TROF THAT SHIFTS THE
WINDS TO THE W IS PUSHING THRU INDIANA. AHEAD OF THIS TROF...AN AREA
OF AC IS DEVELOPING...BUT THEN ADDITIONAL MVFR STRATUS HAS DEVELOP
ACROSS INDIANA.
MEANWHILE A VIGOROUS H5 S/W WILL DIG INTO THE REGION THIS
AFTN...PROVIDING LIFT FOR CONVECTION. EXPECT THE STRATUS TO AFFECT
THE REGION THRU 14-15Z...THEN THE AIRMASS WILL
DESTABILIZE....ESPECIALLY OVER THE ERN TAFS. CONVECTION ALLOWING
MODELS DEVELOP PCPN ACROSS THE ERN TAFS LATE THIS MORNING...BUT
LEAVE THE W DRY. FOLLOWED THIS SCENARIO BY PUTTING VCTS IN THE
ERN TAFS FROM 15-18Z. AS THE UPPER TROF APPROACHES THIS AFTN A FEW
SHRA COULD AFFECT THE WRN TAFS IN THE AFTN.
THE H5 TROF S/W WILL WORK E AFT 00Z. THIS SHOULD BRING AN END TO
THE SHOWER/THUNDERSTORM THREAT. MVFR STRATUS COULD REDEVELOP AFT
06Z TONIGHT.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
619 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTHEAST THROUGH THE CENTRAL GREAT LAKES
TODAY AND FORCE A COLD FRONT EAST ACROSS THE REGION. A TROUGH OF LOW
PRESSURE WILL EXTEND BACK SOUTHWEST FROM THE LOW PRESSURE ACROSS THE
LOCAL AREA BY WEDNESDAY EVENING. HIGH PRESSURE WILL MOVE EAST AND BE
OVER OHIO BY FRIDAY MORNING AND TO THE MID ATLANTIC COAST BY
SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
OCCLUDED FRONT WAS OVER EASTERN OHIO WITH THE POINT OF OCCLUSION
OVER SOUTHEAST OHIO. BACK TO THE WEST...COLD FRONT WAS OVER
EASTERN INDIANA FOLLOWED BY A SURFACE TROUGH OVER SOUTHERN LAKE MICHIGAN.
SHOWERS CONTINUE TO PUSH EAST AHEAD OF THE OCCLUDED FRONT AT THIS
TIME AND WILL BE OUT OF THE AREA SOON. ANOTHER SMALL LINE OF
SHOWERS CONTINUES TO DEVELOP ALONG THE COLD FRONT TO THE WEST AND
WILL SPREAD EAST INTO THE FORECAST AREA TODAY.
GRIDS LOOK REASONABLE AND WILL ONLY ADJUST HOURLY DATA FOR TEMPERATURES.
PREVIOUS DISCUSSION...
UPPER LEVEL TROUGH WILL CONTINUE TO DIG SOUTH
INTO THE FORECAST AREA TODAY. THE SURFACE LOW PRESSURE WILL MOVE
NORTH SLIGHTLY ALLOWING A COLD FRONT TO SLIDE EAST ACROSS THE
FORECAST AREA. DEEP MOISTURE WE EXPERIENCED OVER THE LAST 24 HOURS
HAS SINCE MOVED EAST OF THE REGION. AS COLD FRONT MOVES EAST INTO
THE AREA...SOME SHOWER AND THUNDERSTORM ACTIVITY WILL LIKELY
DEVELOP WITH THE FRONT. STILL EXPECTING SOME SUN AHEAD OF THE
FRONTAL BOUNDARY AND THIS WILL HELP DESTABILIZE THE
ATMOSPHERE...ESPECIALLY IN THE EAST. SPC HAS A SLIGHT RISK FOR
SEVERE THUNDERSTORMS IN THE EAST AT THIS TIME.
TEMPERATURES WILL ONCE AGAIN BE TRICKY DO TO TIMING OF THE COLD
FRONT. RIGHT NOW...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH COLD
FRONT PUSHING INTO TOLEDO AND FINDLAY AROUND NOON AND THEN THROUGH
ERIE BY 8 PM THIS EVENING. THE MORE SUN WE GET THE HIGHER THE
TEMPERATURES. AS MENTIONED...BATTLING THE TIMING OF THE FRONT AS
WELL. BUMPED UP MAX TEMPERATURES A FEW DEGREES FOR TODAY TO ACCOUNT
FOR THE SUN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LEVEL TROUGH STALLS OVER THE NORTHEASTERN UNITED STATES WHILE
IT EVENTUALLY MORPHS INTO A LARGE UPPER LEVEL LOW PRESSURE SYSTEM BY
THURSDAY NIGHT. THIS IS IN RESPONSE TO A PIECE OF ENERGY PLOWING
INTO THE WESTERN UNITED STATES. AN UPPER LEVEL RIDGE OVER THE WEST
CENTRAL UNITED STATES WILL DEAMPLIFY WITH TIME AND WASH OUT BY
FRIDAY NIGHT.
SURFACE LOW PRESSURE WILL CONTINUE TO PULL OUT TO THE NORTHEAST WITH
TIME AND DRAG THE COLD FRONT EAST AND WELL OUT OF THE REGION TONIGHT
AND WEDNESDAY. A TROUGH OF LOW PRESSURE WILL SETTLE IN OVER THE
REGION WEDNESDAY NIGHT AND THEN LIFT OUT AS WELL.
LARGE AREA OF HIGH PRESSURE IS PROGGED TO BUILD EAST SOUTHEAST INTO
THE FORECAST AREA AND BRING A RETURN BACK TO FAIR WEATHER INTO THE
WEEKEND. THE HIGH EVENTUALLY SHIFTS TO THE MID ATLANTIC COAST
BRINGING A RETURN SOUTHERLY FLOW BACK TO THE REGION.
COLD AIR ADVECTION IN THE WAKE OF THE COLD FRONT WILL TAKE PLACE AND
THEN WE SHOULD SEE A GRADUAL WARM UP BY THE LATTER PORTION OF THE
FORECAST PERIOD.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE FORECAST IS BEGINNING TO CHANGE WITH BOTH THE GFS AND ECMWF
BRINGING IN A LOW AND FRONT FOR THE WEEKEND. INTRODUCED 20 POPS FOR
SATURDAY NIGHT AND 30 POPS ON SUNDAY AND THEN ANOTHER WEATHER SYSTEM
WILL BE MOVING IN FOR EARLY NEXT WEEK. TEMPERATURES WILL GO BACK
ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BATCH OF SHOWERS AND THUNDERSTORMS WILL BE EAST OF THE FORECAST
AREA BY 4 AM. SKIES ARE CLEARING FROM THE WEST. WITH PLENTY OF
RAIN EXPECTING FOG AND STRATUS TO DEVELOP. A COLD FRONT WILL BE
MOVING THROUGH DURING THE AFTERNOON. GOING WITH THE HRRR FOR THE
DEVELOPMENT OF THE SQUALL LINE WITH THE FRONT AND SOME SHOWERS
BEHIND IT WITH A TROF. CONDITIONS WILL BEGIN TO IMPROVE FROM THE
WEST AFTER DARK.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
LATE TUESDAY NIGHT/WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
CONTINUING THE SMALL CRAFT ADVISORY ON THE EAST END OF THE LAKE
THROUGH 10 AM BECAUSE OF 15 TO 25 KNOT WINDS FROM THE SOUTH. A COLD
FRONT WILL BE CROSSING THE LAKE TODAY. SOME OF THE THUNDERSTORMS MAY
PROMPT THE NEED FOR A SPECIAL MARINE WARNING...ESPECIALLY LATER
TODAY AND ESPECIALLY ON THE EAST END. THE WINDS WILL SLOWLY PICK UP
TONIGHT THROUGH THURSDAY IN THE COLD ADVECTION. A SMALL CRAFT
ADVISORY MAY BE NEEDED. THIS IS NOT A REAL COLD OUTBREAK AND THE
AIR MASS DRIES OUT QUICKLY. BECAUSE OF THAT WILL NOT MENTION
WATERSPOUTS ON WEDNESDAY...BUT THIS WILL HAVE TO BE WATCHED.
HIGH PRESSURE WILL BEGIN BUILDING IN ON THURSDAY AND WILL MOVE EAST
OF THE LAKE ON SATURDAY AS ANOTHER WEATHER SYSTEM APPROACHES. NOT
EXCEPTING CONDITIONS TO MEET SMALL CRAFT ADVISORY CRITERIA FRIDAY
THROUGH SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ148-
149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
337 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTHEAST THROUGH THE CENTRAL GREAT LAKES
TODAY AND FORCE A COLD FRONT EAST ACROSS THE REGION. A TROUGH OF LOW
PRESSURE WILL EXTEND BACK SOUTHWEST FROM THE LOW PRESSURE ACROSS THE
LOCAL AREA BY WEDNESDAY EVENING. HIGH PRESSURE WILL MOVE EAST AND BE
OVER OHIO BY FRIDAY MORNING AND TO THE MID ATLANTIC COAST BY
SATURDAY MORNING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPPER LEVEL TROUGH WILL CONTINUE TO DIG SOUTH INTO THE FORECAST AREA
TODAY. THE SURFACE LOW PRESSURE WILL MOVE NORTH SLIGHTLY ALLOWING A
COLD FRONT TO SLIDE EAST ACROSS THE FORECAST AREA. DEEP MOISTURE WE
EXPERIENCED OVER THE LAST 24 HOURS HAS SINCE MOVED EAST OF THE
REGION. AS COLD FRONT MOVES EAST INTO THE AREA...SOME SHOWER AND
THUNDERSTORM ACTIVITY WILL LIKELY DEVELOP WITH THE FRONT. STILL
EXPECTING SOME SUN AHEAD OF THE FRONTAL BOUNDARY AND THIS WILL HELP
DESTABILIZE THE ATMOSPHERE...ESPECIALLY IN THE EAST. SPC HAS A
SLIGHT RISK FOR SEVERE THUNDERSTORMS IN THE EAST AT THIS TIME.
TEMPERATURES WILL ONCE AGAIN BE TRICKY DO TO TIMING OF THE COLD
FRONT. RIGHT NOW...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH COLD
FRONT PUSHING INTO TOLEDO AND FINDLAY AROUND NOON AND THEN THROUGH
ERIE BY 8 PM THIS EVENING. THE MORE SUN WE GET THE HIGHER THE
TEMPERATURES. AS MENTIONED...BATTLING THE TIMING OF THE FRONT AS
WELL. BUMPED UP MAX TEMPERATURES A FEW DEGREES FOR TODAY TO ACCOUNT
FOR THE SUN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
UPPER LEVEL TROUGH STALLS OVER THE NORTHEASTERN UNITED STATES WHILE
IT EVENTUALLY MORPHS INTO A LARGE UPPER LEVEL LOW PRESSURE SYSTEM BY
THURSDAY NIGHT. THIS IS IN RESPONSE TO A PIECE OF ENERGY PLOWING
INTO THE WESTERN UNITED STATES. AN UPPER LEVEL RIDGE OVER THE WEST
CENTRAL UNITED STATES WILL DEAMPLIFY WITH TIME AND WASH OUT BY
FRIDAY NIGHT.
SURFACE LOW PRESSURE WILL CONTINUE TO PULL OUT TO THE NORTHEAST WITH
TIME AND DRAG THE COLD FRONT EAST AND WELL OUT OF THE REGION TONIGHT
AND WEDNESDAY. A TROUGH OF LOW PRESSURE WILL SETTLE IN OVER THE
REGION WEDNESDAY NIGHT AND THEN LIFT OUT AS WELL.
LARGE AREA OF HIGH PRESSURE IS PROGGED TO BUILD EAST SOUTHEAST INTO
THE FORECAST AREA AND BRING A RETURN BACK TO FAIR WEATHER INTO THE
WEEKEND. THE HIGH EVENTUALLY SHIFTS TO THE MID ATLANTIC COAST
BRINGING A RETURN SOUTHERLY FLOW BACK TO THE REGION.
COLD AIR ADVECTION IN THE WAKE OF THE COLD FRONT WILL TAKE PLACE AND
THEN WE SHOULD SEE A GRADUAL WARM UP BY THE LATTER PORTION OF THE
FORECAST PERIOD.
&&
.LONG TERM /SATURDAY THROUGH MONDAY/...
THE FORECAST IS BEGINNING TO CHANGE WITH BOTH THE GFS AND ECMWF
BRINGING IN A LOW AND FRONT FOR THE WEEKEND. INTRODUCED 20 POPS FOR
SATURDAY NIGHT AND 30 POPS ON SUNDAY AND THEN ANOTHER WEATHER SYSTEM
WILL BE MOVING IN FOR EARLY NEXT WEEK. TEMPERATURES WILL GO BACK
ABOVE NORMAL EARLY NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BATCH OF SHOWERS AND THUNDERSTORMS WILL BE EAST OF THE FORECAST
AREA BY 4 AM. SKIES ARE CLEARING FROM THE WEST. WITH PLENTY OF
RAIN EXPECTING FOG AND STRATUS TO DEVELOP. A COLD FRONT WILL BE
MOVING THROUGH DURING THE AFTERNOON. GOING WITH THE HRRR FOR THE
DEVELOPMENT OF THE SQUALL LINE WITH THE FRONT AND SOME SHOWERS
BEHIND IT WITH A TROF. CONDITIONS WILL BEGIN TO IMPROVE FROM THE
WEST AFTER DARK.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
LATE TUESDAY NIGHT/WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
CONTINUING THE SMALL CRAFT ADVISORY ON THE EAST END OF THE LAKE
THROUGH 10 AM BECAUSE OF 15 TO 25 KNOT WINDS FROM THE SOUTH. A COLD
FRONT WILL BE CROSSING THE LAKE TODAY. SOME OF THE THUNDERSTORMS MAY
PROMPT THE NEED FOR A SPECIAL MARINE WARNING...ESPECIALLY LATER
TODAY AND ESPECIALLY ON THE EAST END. THE WINDS WILL SLOWLY PICK UP
TONIGHT THROUGH THURSDAY IN THE COLD ADVECTION. A SMALL CRAFT
ADVISORY MAY BE NEEDED. THIS IS NOT A REAL COLD OUTBREAK AND THE
AIRMASS DRIES OUT QUICKLY. BECAUSE OF THAT WILL NOT MENTION
WATERSPOUTS ON WEDNESDAY...BUT THIS WILL HAVE TO BE WATCHED.
HIGH PRESSURE WILL BEGIN BUILDING IN ON THURSDAY AND WILL MOVE EAST
OF THE LAKE ON SATURDAY AS ANOTHER WEATHER SYSTEM APPROACHES. NOT
EXCEPTING CONDITIONS TO MEET SMALL CRAFT ADVISORY CRITERIA FRIDAY
THROUGH SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ148-
149.
&&
$$
SYNOPSIS...LOMBARDY
NEAR TERM...LOMBARDY
SHORT TERM...LOMBARDY
LONG TERM...KIELTYKA
AVIATION...KIELTYKA
MARINE...KIELTYKA
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
153 AM EDT TUE AUG 12 2014
.SYNOPSIS...
LOW PRESSURE ACROSS NORTHWEST OHIO WILL DRIFT NORTHWARD REACHING
LAKE HURON BY TUESDAY MORNING...AND IT WILL TAKE A COLD FRONT
ACROSS THE AREA DURING THE DAY TUESDAY. A TROUGH WILL HANG BACK
ACROSS THE EASTERN LAKES INTO WEDNESDAY WHILE HIGH PRESSURE ACROSS
THE UPPER MIDWEST AND THE GREAT LAKES SHIFTS EASTWARD TO END THE
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LINE OF SHOWERS AND THUNDERSTORMS WILL CONTINUE TO MOVE EAST
ACROSS THE CENTRAL PORTIONS OF THE FORECAST AREA INTO THE EAST.
THIS IS THE BACK EDGE OF THE PRECIPITATION UNTIL THE COLD FRONT
MOVES EAST ACROSS THE FORECAST AREA LATER TODAY. SO MADE SOME
ADJUSTMENTS TO GRIDS AND FORECAST TO ACCOUNT FOR THE CHANGES AND
TIMING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
EASTERN HALF OF THE AREA WITHIN SPC SLIGHT RISK FOR SEVERE
THUNDERSTORMS FOR TUESDAY. AS UPPER TROUGH AMPLIFIES/MID LEVEL
FLOW INCREASES...INSTABILITY/CONVECTION FUELED BY JUST ENOUGH
DAYTIME HEATING COULD BE ENOUGH TO ALLOW SOME OF THE STORMS TO GET
ON THE STRONG SIDE. COLD FRONT CROSSES THE AREA BY EVENING. A FEW
SHOWERS MAY FOLLOW TUESDAY EVENING/NIGHT AS THE UPPER TROUGH AXIS
HAS YET TO CROSS. IT WILL BE FAIRLY CLOUDY TUESDAY...AND HIGHS
WILL TOP OUT IN THE UPPER 70S.
SO LARGE TROUGH ENCOMPASSES THE GREAT LAKES TO NEW ENGLAND AND
AREA WILL REMAIN BELOW NORMAL. A FEW SHOWERS MAY REMAIN ON
WEDNESDAY AS ANOTHER MINOR PIECE OF ENERGY MOVES THROUGH THE
TROUGH. BY THURSDAY THOUGH...MORE DRYING AND HIGH PRESSURE MOVES
ACROSS THE AREA. TEMPERATURES WILL STILL BE HELD TO THE 70S FOR
HIGHS AND 50S AND NIGHT.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
HIGH PRESSURE WILL BUILD OVER THE REGION DURING THE PERIOD. THE
LONG RANGE GUIDANCE IS SIMILAR SO CONFIDENCE IS FAIRLY HIGH TODAY.
THE SURFACE RIDGE WILL MOVE EAST OF THE LOCAL ARE BY NEXT MONDAY.
THIS WILL ALLOW TEMPS AND SURFACE DEW POINTS TO SLOWLY BUILD DURING
THE PERIOD. AFTER STARTING OUT BELOW NORMAL FRIDAY...MONDAY WILL BE
RATHER WARM AND MUGGY. WILL GO MID 80S FOR HIGHS FOR MONDAY BUT
SUSPECT THAT WE WILL EVENTUALLY NEED TO GO WARMER.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A BATCH OF SHOWERS AND THUNDERSTORMS WILL BE EAST OF THE FORECAST
AREA BY 4 AM. SKIES ARE CLEARING FROM THE WEST. WITH PLENTY OF
RAIN EXPECTING FOG AND STRATUS TO DEVELOP. A COLD FRONT WILL BE
MOVING THROUGH DURING THE AFTERNOON. GOING WITH THE HRRR FOR THE
DEVELOPMENT OF THE SQUALL LINE WITH THE FRONT AND SOME SHOWERS
BEHIND IT WITH A TROF. CONDITIONS WILL BEGIN TO IMPROVE FROM THE
WEST AFTER DARK.
OUTLOOK...NON VFR CEILINGS AND VISIBILITY IN PRECIPITATION LINGERING
LATE TUESDAY NIGHT/WEDNESDAY ACROSS NE OH/NW PA.
&&
.MARINE...
LOW PRESSURE WILL PASS WELL TO THE NORTH OF LAKE ERIE ON TUESDAY. A
WARM FRONT FROM THE LOW WILL LIFT NORTH OF THE LAKE TONIGHT CAUSING
THE EASTERLY FLOW TO BECOME SOUTH TO SOUTHWEST. A COLD FRONT WILL
CROSS THE LAKE ON TUESDAY. WINDS WILL BECOME WEST AS THIS OCCURS
BUT SPEEDS SHOULD NOT GET STRONG ENOUGH FOR SMALL CRAFT CONDITIONS.
LOT`S OF THUNDER IS EXPECTED THE NEXT 24 HOURS OR SO. PRECIP WILL
LINGER IN THE EAST INTO WEDNESDAY WITH HIGH PRESSURE THEN BUILDING
IN FROM THE WEST THE REMAINDER OF THE PERIOD. WEST TO SOUTHWEST
WINDS UNDER 15 KNOTS ARE EXPECTED FROM WEDNESDAY THROUGH SUNDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR LEZ148-
149.
&&
$$
SYNOPSIS...OUDEMAN
NEAR TERM...LOMBARDY
SHORT TERM...OUDEMAN
LONG TERM...KUBINA
AVIATION...KIELTYKA
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
326 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT. GENERALLY
DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE SECOND HALF OF
THE WEEK. A WARMING TREND WILL SET IN FOR EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
RADAR LIT UP ALL AROUND US...BUT MAINLY SCT SHRA WITH THE HIGHEST
CONCENTRATION IN THE EASTERN HALF OF THE AREA. CIRCULATION EVIDENT
IN THE DC AREA IS CERTAINLY HELPING THE TORRENTIAL RAINFALL THERE.
SO FAR ONLY AN INCH OF RAIN TOTAL HAS FALLEN INTO THE BUCKETS
THERE. THE ENHANCED RAINFALL LOOKS TO BE MOVING TO THE NORTHEAST
AND IT WILL JUST NIP THE SERN COS...SO NO FLOOD WATCH PLANNED AT
THIS TIME PER COORDINATION WITH PHI WOULD PREFER TO HANDLE ANY
LOCAL PROBLEMS WITH STATEMENTS AND ANY APPROPRIATE WARNINGS WHICH
SHOULD BE A LOW PROB EVENT.
THE STORMS FROM THE WEST ARE GETTING VERY CLOSE AND WARNINGS IN OH
ARE OF CONCERN. SPC MESO DISC ISSUED A WHILE AGO CONCERNING GUSTY
WINDS AND LOWER THREAT FOR ROTATION/TORNADOES. BUT THE TEMPS ARE
JUST STARTING TO RISE IN THE FAR WESTERN COS WHERE IT HAS BROKEN
OUT. HIGH STABILITY IN THE EASTERN TWO-THIRDS OF THE AREA WILL
LIKELY SIGNIFICANTLY WEAKEN THIS CONVECTION AS IT MOVES IN.
STILL...THE SHEAR IS HIGHEST IN THE MORE-STABLE PLACES. THE
CONVECTIVE LINE IN WV ON THE EASTERN FRINGE OF THE SUNNIER AREAS
IS PROGGED NICELY BY THE HRRR AND THE EVOLUTION OF THE CURRENT RUN
OF THIS MESO MODEL IS THOUGHT HIGHLY OF. WILL TREND THE NEAR TERM
POPS/PLACEMENT OF CONVECTION TOWARD IT.
ALL GUIDANCE PROGS THE LAST OF THE HEAVIER SHOWERS/STORMS TO BE
PUSHING OFF TO THE E/NE OF THE CWA BY 06Z. SOME WRAP
AROUND/UPSLOPE SHOWERS WILL COME BACK INTO THE NWRN THIRD OF THE
CWA LATER TONIGHT AND LINGER INTO THE MORNING. BUT DRIER AIR AND
GOOD WESTERLY FLOW WILL HELP TO DRY THINGS UP WELL.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
THE MAIN COLD FRONT WILL BE EAST OF THE AREA BY SUNRISE...WITH
THE TRIPLE POINT.
STILL SOME SHOWERS AND STORMS POSSIBLE UNTIL EARLY AFT...UNTIL
THE SECONDARY FRONT MOVES EAST OF THE AREA.
MUCH OF THE AFTERNOON SHOULD BE DRY AND NOT REAL COLD.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
NOT A LOT OF CHANGE FROM YESTERDAY.
THE DEEP UPPER LVL LOW WILL LIKELY BE SLOW TO MOVE OUT BASED
ON 00Z EC LAST NIGHT...TREND THIS SUMMER...AND EXPERIENCE
JET MAX ROTATION AROUND THE UPPER LVL LOW WILL RESULT IN
A CHC OF SHOWERS FOR THU. STILL A CHC FOR FRIDAY...BUT LESS
OF A CHC.
DID KEEP SOME CHC POPS IN FOR SUNDAY...AS 00Z EC SHOWS UPPER
LVL TROUGH DEEPENING MORE. GFS IS FLATTER AND WETTER. ALSO
DECENT WARM ADVECTION.
DID GO DRY SUNDAY NIGHT INTO MONDAY.
SOME CHC OF SHOWERS AND STORMS ON TUE...AS WARM ADVECTION
SETS IN.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE WAVE IN THE MID-ATLANTIC IS ROLLING NORTH AND FRONT
OVER THE OHIO BORDER IS MARCHING STEADILY INTO THE WESTERN
COUNTIES. CIG AND VISBY BOUNCING ALL OVER THE PLACE AS THE
WIDESPREAD SHOWERS GO OVER THE TERMINALS. CURRENTLY A LACK OF VFR
AS IFR IS ALMOST THE RULE. BREAKS IN THE CLOUDS NEAR JST AND BFD
SHOULD GET BIGGER AND ALLOW THE STORMS FROM THE WEST TO MAKE
INROADS TO AT LEAST THOSE TWO SITES. HOWEVER...THE VERY STABLE
LAYER JUST TO THE EAST OF THOSE TERMINALS WILL REDUCE THE CHC OF
TS FOR THE REST OF THE TAF SITES. GUSTY WINDS WOULD BE POSS IN
THESE STORMS. IPT/MDT WILL KEEP THE E/SE WIND THRU ABOUT
06Z WHEN THE FRONT PASSES. RESIDUAL MOISTURE AND CYCLONIC FLOW
SHOULD KEEP IFR CIGS OVER MUCH OF THE AREA TONIGHT. ALSO KEPT A
MENTION OF SHRA/DZ IN THE WEST. DOWNSLOPE SHOULD HELP EAT UP THE
CLOUDS IN THE SERN HALF TO TWO-THIRDS WED MORNING. BUT JST/BFD
WILL STILL HAVE SCT SHRA FOR MOST OF THE TAF CYCLE.
OUTLOOK...
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SUN...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE/MARTIN
NEAR TERM...DANGELO
SHORT TERM...MARTIN
LONG TERM...MARTIN
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
256 PM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TONIGHT. GENERALLY
DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE SECOND HALF OF
THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
RADAR LIT UP ALL AROUND US...BUT MAINLY SCT SHRA WITH THE HIGHEST
CONCENTRATION IN THE EASTERN HALF OF THE AREA. CIRCULATION EVIDENT
IN THE DC AREA IS CERTAINLY HELPING THE TORRENTIAL RAINFALL THERE.
SO FAR ONLY AN INCH OF RAIN TOTAL HAS FALLEN INTO THE BUCKETS
THERE. THE ENHANCED RAINFALL LOOKS TO BE MOVING TO THE NORTHEAST
AND IT WILL JUST NIP THE SERN COS...SO NO FLOOD WATCH PLANNED AT
THIS TIME PER COORDINATION WITH PHI WOULD PREFER TO HANDLE ANY
LOCAL PROBLEMS WITH STATEMENTS AND ANY APPROPRIATE WARNINGS WHICH
SHOULD BE A LOW PROB EVENT.
THE STORMS FROM THE WEST ARE GETTING VERY CLOSE AND WARNINGS IN OH
ARE OF CONCERN. SPC MESO DISC ISSUED A WHILE AGO CONCERNING GUSTY
WINDS AND LOWER THREAT FOR ROTATION/TORNADOES. BUT THE TEMPS ARE
JUST STARTING TO RISE IN THE FAR WESTERN COS WHERE IT HAS BROKEN
OUT. HIGH STABILITY IN THE EASTERN TWO-THIRDS OF THE AREA WILL
LIKELY SIGNIFICANTLY WEAKEN THIS CONVECTION AS IT MOVES IN.
STILL...THE SHEAR IS HIGHEST IN THE MORE-STABLE PLACES. THE
CONVECTIVE LINE IN WV ON THE EASTERN FRINGE OF THE SUNNIER AREAS
IS PROGGED NICELY BY THE HRRR AND THE EVOLUTION OF THE CURRENT RUN
OF THIS MESO MODEL IS THOUGHT HIGHLY OF. WILL TREND THE NEAR TERM
POPS/PLACEMENT OF CONVECTION TOWARD IT.
ALL GUIDANCE PROGS THE LAST OF THE HEAVIER SHOWERS/STORMS TO BE
PUSHING OFF TO THE E/NE OF THE CWA BY 06Z. SOME WRAP
AROUND/UPSLOPE SHOWERS WILL COME BACK INTO THE NWRN THIRD OF THE
CWA LATER TONIGHT AND LINGER INTO THE MORNING. BUT DRIER AIR AND
GOOD WESTERLY FLOW WILL HELP TO DRY THINGS UP WELL.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE WAVE IN THE MID-ATLANTIC IS ROLLING NORTH AND FRONT
OVER THE OHIO BORDER IS MARCHING STEADILY INTO THE WESTERN
COUNTIES. CIG AND VISBY BOUNCING ALL OVER THE PLACE AS THE
WIDESPREAD SHOWERS GO OVER THE TERMINALS. CURRENTLY A LACK OF VFR
AS IFR IS ALMOST THE RULE. BREAKS IN THE CLOUDS NEAR JST AND BFD
SHOULD GET BIGGER AND ALLOW THE STORMS FROM THE WEST TO MAKE
INROADS TO AT LEAST THOSE TWO SITES. HOWEVER...THE VERY STABLE
LAYER JUST TO THE EAST OF THOSE TERMINALS WILL REDUCE THE CHC OF
TS FOR THE REST OF THE TAF SITES. GUSTY WINDS WOULD BE POSS IN
THESE STORMS. IPT/MDT WILL KEEP THE E/SE WIND THRU ABOUT
06Z WHEN THE FRONT PASSES. RESIDUAL MOISTURE AND CYCLONIC FLOW
SHOULD KEEP IFR CIGS OVER MUCH OF THE AREA TONIGHT. ALSO KEPT A
MENTION OF SHRA/DZ IN THE WEST. DOWNSLOPE SHOULD HELP EAT UP THE
CLOUDS IN THE SERN HALF TO TWO-THIRDS WED MORNING. BUT JST/BFD
WILL STILL HAVE SCT SHRA FOR MOST OF THE TAF CYCLE.
OUTLOOK...
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SUN...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1050 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030AM UPDATE...
RAIN FLYING ALONG TO THE EAST/NORTH. A LTG STRIKE OR TWO BUT
ALMOST NONE AT ALL. RAIN RATES BRIEFLY INTENSE...BUT SPEED OF
MOVEMENT AND SIZE OF SHOWERS LIMITING THE ACCUMS. STRIPE OF 2 INCH
RAIN IN CLEARFIELD CO...BUT ELSEWHERE RAIN LESS THAN A HALF OF AN
INCH. LOW OVER VA/NC IS SLIDING NORTH SLIGHTLY AND WILL MOST
LIKELY SLOW THE PROGRESS OF THE MAIN AREA OF SHOWERS THIS AFTN AS
IT TRIES TO GET OUT OF THE CWA. THUS...MOD RAIN STILL EXPECTED
THERE THROUGH THE REST OF THE DAY AND FOR MOST OF THE NIGHT. A BIG
BREAK IN PRECIP WITH ONLY WIDELY SCT SHRA SHOULD OCCUR OVER THE
WESTERN HALF OF THE AREA UNTIL...
MAIN CONCERN SHIFTS TO THE WEST WITH DIURNAL AND FRONTALLY-FORCED
CONVECTION MOVES IN FROM OH/WRN PA. LINE OF STRONG STORMS OVER
CENTRAL OH IS TIMED INTO OUR WRN COS AROUND 19Z. HOLES IN THE
CLOUDS AND THE FRONTAL LIFT MAKING IT EASY TO HAVE THOSE START UP
TO OUR WEST...BUT CLOUDS SHOULD STAY FAIRLY THICK IN THE CENTRAL
AND EASTERN ZONES. SPC SLIGHT RISK CONTINUES FOR ALL OF THE AREA.
WRN PA STORMS MAY PRODUCE WIND DAMAGE. SRN PA COULD ALSO HAVE
SOME SPINNING STORMS DUE TO THE BOUNDARY ALONG OUR SRN COS OR
BORDER. THIS WILL LEAD TO MORE SHEAR AND THE LCL HEIGHTS SHOULD BE
FAIRLY BUT NOT OVERLY LOW. WILL JUST ADD MENTION OF GUSTY WINDS TO
THE THUNDER IN THE WEST LATE THIS AFTN/EVENING.
PREV...
AN ACTIVE DAY IS IN STORE AS A STRONG UPPER TROUGH AND
ACCOMPANYING FRONTAL SYSTEM ENTERS THE REGION. BIGGEST ISSUES
TODAY WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINS AND
POSSIBILITY OF SEVERE THUNDERSTORMS.
ONCE AGAIN THIS SUMMER WE ARE DEALING WITH A WEATHER SYSTEM
BRINGING UNSEASONABLY STRONG DYNAMICS TO THE FORECAST AREA.
ENSEMBLES AND OPERATIONAL GUIDANCE ALL SHOW A 40-55KT...4-6 STD
DEV...LOW LEVEL SOUTH-SOUTHEASTERLY JET SURGING INTO THE REGION.
THIS HELPS PUSH PWATS IN THE 1.5-2.0 INCH RANGE OVER THE ENTIRE
FCST AREA DURING THE DAY.
THE SETUP SEEMS IS PRIMED FOR A WIDESPREAD MODERATE TO HEAVY RAIN
OVER THE NEXT 12-18 HOURS. HAVE DISCUSSED A POSSIBLE FLOOD WATCH
WITH NEIGHBORING OFFICES AND CONSENSUS IS TO LEAN AWAY FOR THE
TIME BEING GIVEN THE EXPECTED QPF AVERAGING 1-2" AND RECENT
PERIOD OF DRY WEATHER. THE BEST CHANCE FOR DEVELOPING FLOODING
ISSUES SEEMS TO BE ALONG SOME OF THE SMALLER CREEKS AND STREAMS
AND WILL BE HANDLED WITH SHORT TERM ADVISORY/FLOOD PRODUCTS. THE
BEST CHANCE OF THIS WOULD SEEM TO BE OVER ABOUT THE EASTERN HALF
OF MY FCST AREA.
ANOTHER CONCERN IS THAT WHEN THE OCCLUSION/WARM FRONT ENTERS THE
AREA...MARGINAL INSTABILITY AND STRONG SHEAR COULD RESULT IN
SOME LOCALLY SEVERE THUNDERSTORMS WITH AN ISOLATED TORNADO NOT OUT
OF THE QUESTION. RAP AND GFS SHOW A BULLSEYE OF STRONG LOW LEVEL
HELICITY OVER SOUTH CENTRAL PA...IN THE VICINITY OF THE WARM
FRONT THAT WILL BE SLOWLY MOVING NORTH THROUGH EARLY AFTERNOON.
HEATING WILL BE HARD TO COME BY GIVEN THE EXPECTED CLOUD
COVER...BUT IF THE DRY SLOT CAN MANAGE TO INTRODUCE SOME BREAKS IN
THE CLOUDS...MODEL PROJECTIONS OF CAPES IN THE 1000-1500J RANGE
COULD BE REALIZED...HELPING DEVELOP SOME STRONGER UPDRAFTS
INCREASING THE POTENTIAL FOR SEVERE WEATHER. AN EXPECTED LOW LCL
IN THE VERY MOIST ENVIRONMENT WOULD NOT BE A HINDERING FACTOR TO
TORNADO FORMATION SHOULD WE MANAGE TO DEVELOP SOME SUPERCELLS.
SHORT RANGE OPERATIONAL MODELS AGREE IN FORMING A WAVE OR WAVES
ALONG THE FRONT AS IT ENTERS THE MID ATLANTIC STATES...KEEPING
THE RAINFALL GOING OVER EASTERN PA INTO THE EVENING
HOURS. THE RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS OVER MY
EASTERN ZONES AFTER MIDNIGHT.
HIGHS GENERALLY IN THE 70S TODAY WILL BE SOME 5-10 DEG BELOW
NORMAL...WHILE THE OVERNIGHT LOWS WILL BE RELATIVELY MILD FOR
MID AUGUST IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
SHOWERS EXITING THE WESTERN HALF OF THE AREA...ZIPPING ALONG...BUT
THESE SHOULD ALSO SLOW DOWN AND LINE UP MORE S-N AS A LOW PRESSURE
WAVE IN THE LOWER CHESAPEAKE SLIDES NORTHWARD. CIG AND VISBY
BOUNCING ALL OVER THE PLACE AS THE FAST-MOVING SHOWERS GO OVER THE
TERMINALS. THE FRONT/TROUGH APPROACHING FROM THE WEST WILL PRODUCE
NUMEROUS SHRA/TSRA TO OUR WEST AND MOVE THEM INTO THE AREA LATER
THIS AFTN AND EVENING. COVERAGE MAY BE BKN...SO HAVE OPTED TO HOLD
OFF ON MENTIONING T JUST YET. BUT GUSTY WINDS WOULD BE POSS IN
THESE STORMS. THE FRONT PUSHES THROUGH AND WINDS GO WESTERLY AS
THE FRONT MOVES TO THE EAST LATE TONIGHT. RESIDUAL MOISTURE AND
CYCLONIC FLOW SHOULD KEEP LOW MVFR/IFR CIGS OVER MUCH OF THE AREA
TONIGHT.
OUTLOOK...
WED...AM SHRA/LOW CIGS POSSIBLE. OTHERWISE VFR.
THU...AFTN SHRA NW. OTHERWISE VFR.
FRI-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...DANGELO/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
705 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN ACTIVE DAY IS IN STORE AS A STRONG UPPER TROUGH AND
ACCOMPANYING FRONTAL SYSTEM ENTERS THE REGION. BIGGEST ISSUES
TODAY WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINS AND
POSSIBILITY OF SEVERE THUNDERSTORMS.
ONCE AGAIN THIS SUMMER WE ARE DEALING WITH A WEATHER SYSTEM
BRINGING UNSEASONABLY STRONG DYNAMICS TO THE FORECAST AREA.
ENSEMBLES AND OPERATIONAL GUIDANCE ALL SHOW A 40-55KT...4-6 STD
DEV...LOW LEVEL SOUTH-SOUTHEASTERLY JET SURGING INTO THE REGION.
THIS HELPS PUSH PWATS IN THE 1.5-2.0 INCH RANGE OVER THE ENTIRE
FCST AREA DURING THE DAY.
THE SETUP SEEMS IS PRIMED FOR A WIDESPREAD MODERATE TO HEAVY RAIN
OVER THE NEXT 12-18 HOURS. HAVE DISCUSSED A POSSIBLE FLOOD WATCH
WITH NEIGHBORING OFFICES AND CONSENSUS IS TO LEAN AWAY FOR THE
TIME BEING GIVEN THE EXPECTED QPF AVERAGING 1-2" AND RECENT
PERIOD OF DRY WEATHER. THE BEST CHANCE FOR DEVELOPING FLOODING
ISSUES SEEMS TO BE ALONG SOME OF THE SMALLER CREEKS AND STREAMS
AND WILL BE HANDLED WITH SHORT TERM ADVISORY/FLOOD PRODUCTS. THE
BEST CHANCE OF THIS WOULD SEEM TO BE OVER ABOUT THE EASTERN HALF
OF MY FCST AREA.
ANOTHER CONCERN IS THAT WHEN THE OCCLUSION/WARM FRONT ENTERS THE
AREA...MARGINAL INSTABILITY AND STRONG SHEAR COULD RESULT IN
SOME LOCALLY SEVERE THUNDERSTORMS WITH AN ISOLATED TORNADO NOT OUT
OF THE QUESTION. RAP AND GFS SHOW A BULLSEYE OF STRONG LOW LEVEL
HELICITY OVER SOUTH CENTRAL PA...IN THE VICINITY OF THE WARM
FRONT THAT WILL BE SLOWLY MOVING NORTH THROUGH EARLY AFTERNOON.
HEATING WILL BE HARD TO COME BY GIVEN THE EXPECTED CLOUD
COVER...BUT IF THE DRY SLOT CAN MANAGE TO INTRODUCE SOME BREAKS IN
THE CLOUDS...MODEL PROJECTIONS OF CAPES IN THE 1000-1500J RANGE
COULD BE REALIZED...HELPING DEVELOP SOME STRONGER UPDRAFTS
INCREASING THE POTENTIAL FOR SEVERE WEATHER. AN EXPECTED LOW LCL
IN THE VERY MOIST ENVIRONMENT WOULD NOT BE A HINDERING FACTOR TO
TORNADO FORMATION SHOULD WE MANAGE TO DEVELOP SOME SUPERCELLS.
SHORT RANGE OPERATIONAL MODELS AGREE IN FORMING A WAVE OR WAVES
ALONG THE FRONT AS IT ENTERS THE MID ATLANTIC STATES...KEEPING
THE RAINFALL GOING OVER EASTERN PA INTO THE EVENING
HOURS. THE RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS OVER MY
EASTERN ZONES AFTER MIDNIGHT.
HIGHS GENERALLY IN THE 70S TODAY WILL BE SOME 5-10 DEG BELOW
NORMAL...WHILE THE OVERNIGHT LOWS WILL BE RELATIVELY MILD FOR
MID AUGUST IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
SHOWERS CONTINUE TO STREAM THROUGH CENTRAL PA THIS MORNING. THESE
SHOWERS...HEAVY AT TIMES. WILL CONTINUE TO ALLOW FOR IFR CIGS AT
BFD...JST...AOO AND AT TIMES...UNV. THESE SHOWERS ARE DUE TO A
SLOW MOVING WARM FRONT TREKKING THROUGH PENNSYLVANIA TODAY.
BFD..JST AND AOO DUE TO UPSLOPE FLOW REMAINS IFR. THESE CONDITIONS
WILL PERSIST THROUGH MID MORNING...BEFORE IMPROVING SLIGHTLY TO
MVFR BY THE EARLY AFTERNOON HOURS AFTER THE WARM FRONT LIFTS
THROUGH THE AREA. A TROUGH OF LOW PRESSURE APPROACHING FROM THE
WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH COULD PRODUCE BRIEF
IFR VSBYS AND GUSTY WINDS DURING THE AFTERNOON AND EARLY EVENING
HOURS.
CIGS AND VSBYS ELSEWHERE SHOULD BE MVFR AT TIMES WITH POSSIBLE IFR
IN SHRA/TSRA THIS EVENING ACROSS THE EASTERN TAF SITES.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
416 AM EDT TUE AUG 12 2014
.SYNOPSIS...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN ACTIVE DAY IS IN STORE AS A STRONG UPPER TROUGH AND
ACCOMPANYING FRONTAL SYSTEM ENTERS THE REGION. BIGGEST ISSUES
TODAY WILL BE THE POTENTIAL FOR LOCALLY HEAVY RAINS AND
POSSIBILITY OF SEVERE THUNDERSTORMS.
ONCE AGAIN THIS SUMMER WE ARE DEALING WITH A WEATHER SYSTEM
BRINGING UNSEASONABLY STRONG DYNAMICS TO THE FORECAST AREA.
ENSEMBLES AND OPERATIONAL GUIDANCE ALL SHOW A 40-55KT...4-6 STD
DEV...LOW LEVEL SOUTH-SOUTHEASTERLY JET SURGING INTO THE REGION.
THIS HELPS PUSH PWATS IN THE 1.5-2.0 INCH RANGE OVER THE ENTIRE
FCST AREA DURING THE DAY.
THE SETUP SEEMS IS PRIMED FOR A WIDESPREAD MODERATE TO HEAVY RAIN
OVER THE NEXT 12-18 HOURS. HAVE DISCUSSED A POSSIBLE FLOOD WATCH
WITH NEIGHBORING OFFICES AND CONSENSUS IS TO LEAN AWAY FOR THE
TIME BEING GIVEN THE EXPECTED QPF AVERAGING 1-2" AND RECENT
PERIOD OF DRY WEATHER. THE BEST CHANCE FOR DEVELOPING FLOODING
ISSUES SEEMS TO BE ALONG SOME OF THE SMALLER CREEKS AND STREAMS
AND WILL BE HANDLED WITH SHORT TERM ADVISORY/FLOOD PRODUCTS. THE
BEST CHANCE OF THIS WOULD SEEM TO BE OVER ABOUT THE EASTERN HALF
OF MY FCST AREA.
ANOTHER CONCERN IS THAT WHEN THE OCCLUSION/WARM FRONT ENTERS THE
AREA...MARGINAL INSTABILITY AND STRONG SHEAR COULD RESULT IN
SOME LOCALLY SEVERE THUNDERSTORMS WITH AN ISOLATED TORNADO NOT OUT
OF THE QUESTION. RAP AND GFS SHOW A BULLSEYE OF STRONG LOW LEVEL
HELICITY OVER SOUTH CENTRAL PA...IN THE VICINITY OF THE WARM
FRONT THAT WILL BE SLOWLY MOVING NORTH THROUGH EARLY AFTERNOON.
HEATING WILL BE HARD TO COME BY GIVEN THE EXPECTED CLOUD
COVER...BUT IF THE DRY SLOT CAN MANAGE TO INTRODUCE SOME BREAKS IN
THE CLOUDS...MODEL PROJECTIONS OF CAPES IN THE 1000-1500J RANGE
COULD BE REALIZED...HELPING DEVELOP SOME STRONGER UPDRAFTS
INCREASING THE POTENTIAL FOR SEVERE WEATHER. AN EXPECTED LOW LCL
IN THE VERY MOIST ENVIRONMENT WOULD NOT BE A HINDERING FACTOR TO
TORNADO FORMATION SHOULD WE MANAGE TO DEVELOP SOME SUPERCELLS.
SHORT RANGE OPERATIONAL MODELS AGREE IN FORMING A WAVE OR WAVES
ALONG THE FRONT AS IT ENTERS THE MID ATLANTIC STATES...KEEPING
THE RAINFALL GOING OVER EASTERN PA INTO THE EVENING
HOURS. THE RAIN SHOULD TAPER OFF TO SCATTERED SHOWERS OVER MY
EASTERN ZONES AFTER MIDNIGHT.
HIGHS GENERALLY IN THE 70S TODAY WILL BE SOME 5-10 DEG BELOW
NORMAL...WHILE THE OVERNIGHT LOWS WILL BE RELATIVELY MILD FOR
MID AUGUST IN THE MID 50S TO MID 60S.
&&
.SHORT TERM /WEDNESDAY/...
THE SURFACE LOW AND FRONTAL SYSTEM WILL BE MOVING AWAY FROM THE
REGION WEDNESDAY...BUT WITH THE LAGGING UPPER TROUGH AND COLD AIR
ALOFT WE WILL SEE AT LEAST SOME SCATTERED SHOWERS...AND EVEN THE
POSSIBILITY OF A RUMBLE OF THUNDER. MID LEVEL LAPSE RATES ARE NOT
PROGGED TO BE PARTICULARLY IMPRESSIVE SO THE THUNDER CHANCES WILL
NOT BE ESPECIALLY HIGH.
IT WILL BE ANOTHER COOLER THAN NORMAL DAY RANGING FROM THE UPPER
60S TO UPPER 70S NW-SE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MUCH OF THE EXTENDED PERIOD WILL BE DOMINATED BY COOL CYCLONIC
FLOW ALOFT AROUND THE UNSEASONABLY STRONG UPPER LOW/TROUGH THAT
WILL ONLY SLOWLY LIFT THROUGH THE NERN US. THIS SHOULD MEAN A
FAIR AMOUNT OF STRATOCU COOKING UP WITH DAYTIME HEATING AND
PERHAPS A FEW SHOWERS STICKING AROUND INTO THURSDAY.
ENSEMBLES AND THE GFS/ECMWF ALL SHOW UPPER HEIGHTS BEGINNING TO
REBOUND BY THE END OF THE WEEK WITH DRY CONDITIONS FOR FRIDAY AND
SATURDAY. THE DIFFERENCES BEGIN TO ARISE AFTER SATURDAY WITH THE
ECMWF SHOWING A SHARP SHORTWAVE DROPPING DOWN INTO PA FROM NORTH
OF THE LAKES WHILE THE GFS/GEFS INTRODUCE WET WEATHER UNDER A
FLATTER UPPER FLOW IMPLYING WE BECOME VULNERABLE TO CONVECTION
FORMING OVER THE UPPER MIDWEST THAT GETS FUNNELED EAST UNDER THE
MUCH FLATTER UPPER FLOW. GIVEN THE UNCERTAINTY I OPTED FOR A
PRETTY BLAND SMALL MENTION OF SHOWERS THROUGH MONDAY.
FOR THE VERY EXTENDED THE ECMWF SHOWS A RARE...FOR THIS
SUMMER...SURGE IN THE WESTERN ATLANTIC SUBTROPICAL RIDGE WITH 500
MB HEIGHTS EXCEEDING 5900M ALL THE WAY INTO SOUTHERN NEW ENGLAND.
GIVEN THE TENDENCY FOR A TROUGH TO DOMINATE OUR WEATHER MUCH OF
THIS SUMMER...THIS SOLUTION HAS TO BE VIEWED DUBIOUSLY AT THIS
TIME...BUT MAY GIVE HOPE TO REAL SUMMER LOVERS THAT WE COULD HAVE
AT LEAST ONE TRUE HEAT WAVE IN STORE FOR US.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY OVERNIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE
REGION. THE REGION OF MOST CONCERN WILL BE THE CENTRAL
MTNS...INCLUDING KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE
HIGHER TERRAIN HAS RESULTED IN IFR CIGS. CIGS HAVE FALLEN TO
800FT OR LOWER AT KJST...BFD AND KAOO. UNV REMAINS OVERCAST AT
1500FT. MODELS STILL SUGGEST UNV COULD DROP TO IFR...BETWEEN 09Z
TO 15Z. IPT IS RECEIVING HEAVIER RAIN...YET IFR FOR THEM SEEMS
LESS LIKELY THOUGH POSSIBLE. MDL SOUNDINGS SUGGEST THE LOWER
ELEVATION AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER THAN
MVFR LATE TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT THROUGH TUESDAY...ACCOMPANIED BY NUMEROUS
SHRA AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS UP TO 30KTS TUE AM AT KIPT...WHERE TOPOGRAPHY
EFFECTS ENHANCE THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE
LIKELY TO BE LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
134 AM EDT TUE AUG 12 2014
.SYNOPSIS/...
A STRONG FRONTAL SYSTEM WILL CROSS THE AREA TODAY AND TONIGHT.
GENERALLY DRIER AND COOLER CONDITIONS CAN BE EXPECTED FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
RADAR SHOWS A LARGE AREA OF SHOWERS WITH EVEN SOME EMBEDDED
THUNDERSTORMS EVIDENT OVER WESTERN PARTS OF THE AREA. REGIONAL
RADAR SHOWS CONVECTION FIRING UPSTREAM ALL THE WAY BACK TO
SOUTHERN OHIO AND WEST VIRGINIA...SUPPORTING THE SHORT RANGE HIGH
RES MODEL IDEAS OF FREQUENTS SHOWERS AND THUNDERSTORMS RIGHT
THROUGH THE MORNING INTO THE AFTERNOON.
A BLEND OF HPC AND MODEL ENSEMBLE QPF SUPPORTS A WIDESPREAD
SOAKING RAIN OF 1 TO 2 INCHES...WITH SOME LOCALIZED HIGHER AMOUNTS
LIKELY OVER EASTERN AREAS.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM WEDNESDAY/...
THE SFC BASED STABILITY LOOKS TO REMAIN HIGH THROUGHOUT MOST OF
THE UPCOMING EVENT. SOUNDINGS DO LOOK MOIST ADIABATIC SO THUNDER
WILL PROBABLY BE ISOLATED TO POCKETS WHERE BEST FORCING APPEAR.
THE DEEPEST MOISTURE AND AXIS OF STRONGEST WINDS WILL BE BISECT
THE STATE TUESDAY...SO A VERY WET TUESDAY IS IN STORE FOR THE
CENTRAL AREAS IN THE MORNING AND EASTERN LOCATIONS ALL DAY
LONG...AND THROUGH THE NIGHT. SOME LLVL INSTABILITY COULD ENHANCE
THE RAIN RATES IN THE SE HALF OF THE AREA. GIVEN EXTENSIVE CLOUD
COVER AND PRECIPITATION...MOST AREAS WILL REMAIN IN THE U60S AND
L/M70S TUESDAY AFTERNOON.
SPC HAS PLACED MUCH OF THE AREA INTO THE SLIGHT RISK AREA FOR
TUESDAY...BUT WE WILL HAVE TO POKE SOME BIG HOLES IN THE CLOUDS
WHICH LOOK LIKE A FORMIDABLE TASK. THE EXCEPTION TO THIS MAY BE
OVER THE W/SW WHERE DRY AIR MAY SHOVE IN FROM THE WEST IN THE
AFTN. HAVE ONLY MENTIONED SLIGHT CHC THUNDER FOR NOW. THE
SOUNDINGS/CROSS SECTIONS LOOK VERY MOIST THRU MOST OF THE AREA.
UNSETTLED AND WET WEATHER WILL CONTINUE INTO TUESDAY NIGHT AS THE
FRONT PASSES THROUGH MOST OF THE AREA...BEFORE THE UPPER LOW
PUSHES ACROSS NY STATE ON WED/THU. THE FRONT WILL LIKELY HANG UP
AS THE WAVE DEVELOPING ALONG THE COAST MOVES UP TO OUR LATITUDE.
POTENTIAL HEAVIER RAINS WILL BE OVER EASTERN SECTIONS OF CWA
TUESDAY NIGHT.
WITHOUT AN SPECIFIC INTENSE PERIOD OF RAIN/CONVECTION...AND LITTLE
OR NO RAIN IN THE LAST 6-7 DAYS...NO FLOOD WATCH AT THIS POINT.
BUT WILL LEAVE MENTIONS OF HEAVY RAIN POTENTIAL IN THE HWO.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SOME MODEL SPREAD...CLOUDS COULD REMAIN STUBBORN ACROSS THE MTNS
ON WED...AS COLD POOL ASSOCIATED WITH UPPER LOW REMAINS OVERHEAD.
THE WAVE ALONG THE EAST COAST APPEARS TO SLOW THINGS UP. THUS SOME
SHOWERS AND STORMS STILL LIKELY...AT LEAST EARLY ON. DID NOT MAKE
A LOT OF CHANGES TO THE POPS. STILL A LOT OF MODEL SPREAD ON THE
DETAILS. THIS BEEN THE PATTERN FOR MUCH OF THE SUMMER SO FAR.
STILL A CHC OF A SHOWER ON THU ACROSS THE NORTH WITH THE UPPER
LVL LOW.
AFTER THIS...WENT WITH A DRY FOR FCST INTO NEXT MONDAY. A RATHER
DEEP UPPER LVL LOW WILL SLOWLY LIFT OUT...LEAVING US IN A NW
FLOW OF COOLER AND DRIER AIR.
TEMPS REMAIN BELOW AVERAGE LATE WEEK...WITH A MODERATING TREND
FOR THE WEEKEND AS RIDGE AXIS SLIDES THROUGH OHIO VALLEY. THIS
WILL COINCIDE WITH AN EXTENDED PERIOD OF DRY WEATHER.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
A SLOW-MOVING WARM FRONT WILL APPROACH PENNSYLVANIA FROM THE OHIO
VALLEY TONIGHT...SPREADING LOWERING CIGS AND SHRA INTO THE REGION.
THE REGION OF MOST CONCERN WILL BE THE CENTRAL MTNS...INCLUDING
KJST/KAOO/KUNV/KBFD...WHERE SE FLOW ASCENDING THE HIGHER TERRAIN
IS LIKELY TO RESULT IN IFR CIGS. CIGS HAVE FALLEN TO 900FT AT KJST
AND KAOO AT 03Z AND RAP SOUNDINGS SUGGEST KUNV AND KBFD WILL
FOLLOW SUIT BY ARND 06Z. MDL SOUNDINGS SUGGEST THE LOWER ELEVATION
AIRFIELDS OF KMDT AND KLNS WILL LIKELY GO NO LOWER THAN MVFR LATE
TONIGHT.
A BAND OF STRONG SOUTHERLY WINDS ALOFT WILL MOVE THROUGH THE
REGION LATE TONIGHT AND TUESDAY...ACCOMPANIED BY NUMEROUS SHRA
AND TSRA. WARM FRONT IS EXPECTED TO LIFT INTO THE AREA BY TUE
AFTN...CAUSING CIGS TO RISE A BIT. HOWEVER...TROUGH OF LOW PRES
APPROACHING FROM THE WEST WILL PRODUCE NUMEROUS SHRA/TSRA...WHICH
COULD PRODUCE BRIEF IFR VSBYS AND GUSTY WINDS DURING THE PM HOURS.
AN EXAMINATION OF LATEST MDL SOUNDINGS SUGGESTS WE WILL FALL JUST
SHORT OF LLWS CRITERIA LATE TONIGHT AND EARLY TUE...AS BAND OF
STRONG WINDS ALOFT PASSES OVR PA. HOWEVER...LOCALLY GUSTY SFC
WINDS ARE EXPECTED LATER TONIGHT AND EARLY TUESDAY. BUFKIT
SOUNDINGS SUPPORT OCNL GUSTS BTWN 20-25KTS OVR THE CENTRAL
MTNS AND PERHAPS UP TO 30KTS TUE AM AT KIPT...WHERE TOPOGRAPHY
EFFECTS ENHANCE THE GUST POTENTIAL. ACROSS SE PA...THE WINDS ARE
LIKELY TO BE LIGHTER AT KMDT AND KLNS.
OUTLOOK...
TUE NIGHT...SHRA/TSRA. LOW CIGS/VSBYS POSSIBLE.
WED...AM SHRA/LOW CIGS POSSIBLE.
THU-SAT...NO SIG WX EXPECTED.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LA CORTE
AVIATION...FITZGERALD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
440 AM EDT TUE AUG 12 2014
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL ENHANCE CHANCES FOR SHOWERS AND
THUNDERSTORMS BEFORE IT PASSES THROUGH THE AREA TONIGHT. DRY HIGH
PRESSURE WILL THEN SETTLE OVER THE REGION AND REMAIN THROUGH THE
END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
430 AM UPDATE...WITH MOST OF THE PRECIP ACTIVITY ACRS THE CWFA
WANING AS INSTABILITY IS EXHAUSTED...ADJUSTED POPS GENERALLY
DOWNWARD THRU THE EARLY MRNG. NEWEST AVBL HRRR SUGGESTS NO
MEASURABLE PRECIP DEVELOPMENT UNTIL AFTER DIURNAL HEATING BEGINS AND
THIS SEEMS REASONABLE.
AS OF 300 AM EDT...HEIGHTS FALL STEADILY TODAY AND TONIGHT AS UPPER
TROUGH DIGS INTO THE MID-ATLANTIC AND CAROLINAS. A SFC LOW WILL LIFT
NWD ACROSS LAKE HURON AND THE TRAILING COLD FRONT WILL SLOWLY
PROGRESS ACRS THE SRN APPALACHIAN REGION LATE AFTERNOON AND
OVERNIGHT. THE WEDGE WHICH REMAINED OVER MUCH OF THE AREA SUN-MON
APPEARS TO HAVE ALREADY RETREATED INTO CENTRAL NC/VA WITH SOUTHERLY
FLOW PREVAILING INTO THE FA. LLVL WINDS WILL CONTINUE TO VEER
GRADUALLY TO SW THIS MORNING. THE WEDGE WILL RETREAT FURTHER AND
THERMAL GRADIENT WILL WEAKEN ACRS THE AREA TODAY...AND DIURNALLY
DRIVEN CONVECTION WILL BE THE PRIMARY DRIVER FOR PRECIP. NAM/GFS
INDICATE THE DEVELOPMENT OF A PREFRONTAL TROUGH OVER THE SE HALF OF
THE FA THIS AFTN WHICH IS EXPECTED TO PROVIDE A FOCUSING MECHANISM.
MODEL GUIDANCE SUGGESTS IT WILL BE STRONGER THAN THE UPSLOPE FORCING
PROVIDED BY THE VEERED FLOW...SO GREATEST POPS ARE FCST EAST OF THE
BLUE RIDGE. MOSTLY CLOUDY SKIES AND STILL RELATIVELY LOW THICKNESSES
WILL KEEP HIGHS A CATEGORY OR SO BELOW CLIMO OVER MOST OF THE AREA.
SBCAPE VALUES PROGGED BY NAM/GFS ARE STRONGER THAN WHAT WE/VE DEALT
WITH THE PAST FEW DAYS...1000-1500 J/KG. THIS VALUE SUPPORTED BY SREF
PROBS.H5 FLOW INCREASES STEADILY THRU THE DAY AS THE BASE OF THE
TROUGH APPROACHES...WITH UPPER DRYING ALSO OCCURRING THEREIN. 0-6KM
SHEAR WITH UNIDIRECTIONAL PROFILE IS 25-30 KT OVER THE AREA BY SUNSET
WHICH IS SUFFICIENT TO EXPECT AT LEAST LOOSE LINEAR ORGANIZATION TO
CONVECTIVE ACTIVITY. THE DRYING ALOFT SUGGESTS HIGHER DCAPES AND A
MARGINAL STRONG/SEVERE WIND THREAT. SPC HAS MOST OF OUR AREA WITHIN
THE 5 PERCENT CONTOURS FOR WIND/HAIL ON THE NEW DAY 1 OTLK. THE WIND
THREAT SEEMS LIKE A BETTER BET BUT FREEZING LEVELS ARE NOT ESPECIALLY
HIGH SO AT LEAST NEAR-SEVERE HAIL IS A POSSIBILITY. PWATS REMAIN
ELEVATED BUT WILL DROP AS THE DRIER AIR WORKS IN ALOFT...STILL
SUPPORTING WIND AS THE PRIMARY CONCERN.
THE SFC FRONT PUSHES INTO THE MTNS THIS EVENING AND IS TIMED TO EXIT
THE CWFA BEFORE DAYBREAK. DOWNSLOPING NW FLOW EAST OF THE MTNS SHOULD
LEAD TO CLEARING SKIES THERE AFTER MIDNIGHT...BUT SUFFICIENT LLVL
MOISTURE IS PRESENT TO KEEP LINGERING CLOUDS/POPS ALONG THE TENN
BORDER LATER INTO THE NIGHT. MIN TEMPS WILL BE SLIGHTLY BELOW CLIMO
IN THE DRIER CONTINENTAL AIRMASS AND WITH PARTIAL CLEARING.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 250 AM TUESDAY...VERY QUIET AND UNSEASONABLY PLEASANT WEATHER
IS EXPECTED DURING THE SHORT TERM...BY WHICH TIME A CONTINENTAL AIR
MASS WILL BE WELL-ESTABLISHED ACROSS THE SOUTHEAST AND MID-ATLANTIC
BENEATH AN UPPER LONG WAVE TROUGH. WHILE DAYTIME TEMPERATURES WILL
BE AS MUCH AS 5 DEGREES BELOW CLIMO...THE MOST NOTICEABLE DIFFERENCE
FROM TYPICAL AUGUST WEATHER WILL BE THE LOW DEWPOINTS...WHICH WILL
LIKELY MIX OUT INTO THE 50S IN MOST AREAS WED AND THU AFTERNOONS.
THE DRY AIR WILL ALSO SUSTAIN MIN TEMPS AT LEAST 5 DEGREES BELOW
NORMAL. NEEDLESS TO SAY...PRECIP CHANCES ARE VIRTUALLY NIL THROUGH
THE PERIOD.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 3 AM TUESDAY...THERE IS ACTUALLY A RATHER SIGNIFICANT CHANGE
IN THE GLOBAL MODELS RE: THE SYNOPTIC PATTERN OVER THE CONUS FOR THE
WEEKEND AND EARLY NEXT WEEK. WHEREAS YESTERDAY/S RUNS WERE
ATTEMPTING TO NOSE THE SUBTROPICAL RIDGE INTO THE SOUTHEAST BY
SATURDAY OR SO...BOTH THE GFS AND THE ECMWF HAVE PICKED UP ON A
SHORT WAVE TROUGH IN THE FOUR CORNERS REGION ROUNDING THE STRONG
WESTERN HIGH AND ESSENTIALLY BREAKING DOWN THE RIDGE. THIS WOULD
TEND TO MAINTAIN ANOMALOUSLY LOW HEIGHTS ACROSS THE EASTERN CONUS
THROUGH THE PERIOD. IN FACT...THE AFOREMENTIONED SHORT WAVE COULD
MANAGE TO REINFORCE THE TROUGH TO SOME EXTENT BY EARLY NEXT
WEEK...BUT EXACTLY HOW THAT WILL EVOLVE IS VERY UNCERTAIN ATTM.
IN THE INTERIM...A SHORT WAVE ROUNDING THE BASE OF THE UPPER LOW
ACROSS SOUTHEAST CANADA IS EXPECTED TO SEND A REINFORCING COOL FRONT
TOWARD THE AREA LATE THIS WEEK. HOWEVER...IT APPEARS THE ATMOSPHERE
MAY BE TOO DRY/STABLE TO SUPPORT MUCH IN THE WAY OF CONVECTION. SOME
TOKEN SLIGHT CHANCES WILL NEVERTHELESS BE CARRIED FRIDAY...MAINLY
ACROSS THE HIGH TERRAIN. DEPENDING UPON THE EVOLUTION OF THE /RIDGE
BUSTING/ SHORT WAVE...MOISTURE MAY BEGIN TO INCREASE BY THE END OF
THE PERIOD... AND CONVERGENCE TOWARD MORE CLIMO-APPROPRIATE POPS
SEEMS REASONABLE BY DAY 7. TEMPS ARE GENERALLY EXPECTED TO REMAIN
SLIGHTLY BELOW NORMAL THROUGH THE PERIOD.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
AT KCLT...IFR HAS CREPT BACK IN ON MOIST SELY FLOW. EVEN AS AN
APPROACHING TROUGH VEERS THE LLVL FLOW BETWEEN NOW AND DAWN...ENOUGH
UPGLIDE SHOULD STILL BE PRESENT TO MAINTAIN THE CIGS. THE LIGHT
WINDS ARE EXPECTED TO KEEP THINGS MIXED ENOUGH TO PRECLUDE ANY LIFR.
THOUGH SOME SPRINKLES OR VERY LIGHT SHOWERS COULD OCCUR THIS
MRNG...SCT DIURNAL SHRA/TSRA THIS AFTN WILL PROVIDE THE BEST CHANCE
OF PRECIP IN THE PERIOD. COLD FRONT WILL APPROACH THIS EVENING...BUT
WINDS STAY SWLY THRU 06Z.
ELSEWHERE...LLVL FLOW HAS ALREADY VEERED TO SOUTHERLY ACRS THE AREA.
LINGERING ELEVATED INSTABILITY WILL DRIVE SOME SHRA AND A FEW TSRA
THRU THE EARLY MRNG...MAINLY ALONG AND JUST S/E OF THE BLUE RIDGE
WHERE UPSLOPE AND WARM UPGLIDE ARE WORKING TOGETHER. IFR WILL SLOWLY
EXPAND ACRS ALL THE SITES IF NOT ALREADY. THE CIGS SHOULD LIFT BY
MID-LATE MRNG IN TIME TO ALLOW SUFFICIENT TIME TO DESTABILIZE FOR
SCT TSRA. CHANCES ARE GENERALLY IN PROB30 RANGE. COLD FRONT WILL
SWEEP THROUGH TONIGHT...BUT THE WIND SHIFT IS NOT EXPECTED TO OCCUR
UNTIL AFTER 06Z EXCEPT AT KAVL.
OUTLOOK...DRIER VFR CONDITIONS WILL ARRIVE WED IN THE WAKE OF A COLD
FRONT AND CONTINUE THROUGH LATE WEEK.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 80% MED 70% LOW 57% HIGH 83%
KGSP HIGH 83% HIGH 88% HIGH 100% HIGH 100%
KAVL HIGH 81% MED 77% HIGH 100% HIGH 84%
KHKY HIGH 84% MED 73% HIGH 100% HIGH 80%
KGMU MED 75% HIGH 88% HIGH 100% HIGH 100%
KAND MED 77% HIGH 82% 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...WIMBERLEY
NEAR TERM...WIMBERLEY
SHORT TERM...JDL
LONG TERM...JDL
AVIATION...WIMBERLEY
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
528 PM MDT WED AUG 13 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 247 PM MDT WED AUG 13 2014
UPPER RIDGING ACROSS THE CENTRAL CONUS CONTINUES WITH AN UPPER LOW
OVER THE PACIFIC NW. DEEP SWRLY FLOW HAS DEVELOPED ACROSS THE DESERT
SW INTO THE GREAT BASIN AND CNTRL ROCKIES...WITH INCREASING
MONSOONAL MOISTURE OVER MUCH OF THE WRN CONUS. A SERIES OF UPPER
WAVES ARE CROSS WY/ERN MT ATTM...WITH A MUCH STRONGER WAVE OVER
AZ/UT. STORMS HAVE ALREADY FIRED AHEAD OF THE FIRST WAVE NOW
CROSSING THE WRN/CNTRL CWA. RAP MODEL IS SHOWING 3000 J/KG
MLCAPE...BUT WITH A CAP IN PLACE...CONVECTION HAS BEEN LIMITED TO
HIGHER TERRAIN OF THE BLKHLS. HRRR SHOWS MORE STORMS DEVELOPING OVER
THE NEXT HOUR OR TWO ACROSS NE WY AND PUSHING EAST THROUGH THE EVNG
HOURS. MOST OF THE STORM ACTIVITY WOULD BE EAST OF THE CWA BY 06Z
WITH LINGERING SHOWERS POSSIBLE. WEAK SHEAR WILL KEEP STORMS FROM
REACHING SEVERE...THOUGH WITH STRONG INSTABILITY CANT RULE OUT A
STORM OR TWO PRODUCING SMALL HAIL AND GUSTY WINDS LIKE THE STORM
OVER THE NORTHERN BLACK HILLS LIKELY DID EARLIER THIS AFTERNOON.
STRONG WAVE OVER THE SWRN CONUS WILL SLIDE NE TONIGHT...THEN CROSS
THE CWA LATE THURSDAY. MONSOONAL FLOW WILL RESULT IN INCREASINGLY
MOIST PROFILES THROUGH THE DAY THURSDAY WITH PWATS FORECAST TO BE
180 PERCENT OF NORMAL OR MORE. WIND PROFILES SUGGEST STORMS WILL BE
SLOW MOVING WITH MEAN STORM MOTION UNDER 10KT. STORMS WILL CONTINUE
THROUGH THURSDAY NIGHT AS THE SYSTEM SLOWLY MOVES E/NE INTO ND/CNTRL
SD. WITH THE HEAVY RAINS THAT MANY AREAS HAVE RECEIVED IN THE LAST
WEEK...THINK THERE WILL BE A POTENTIAL FOR FLASH FLOODING THURSDAY
AFTERNOON AND THROUGH THURSDAY NIGHT. HAVE ISSUED A FLASH FLOOD
WATCH FOR THIS TIME PERIOD.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 247 PM MDT WED AUG 13 2014
SEVERAL SHORTWAVES WILL AFFECT THE FORECAST AREA FROM FRIDAY INTO
EARLY NEXT WEEK...BRINGING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
TO PARTS OF THE FORECAST AREA NEARLY EVERY DAY. ON FRIDAY...A SLOW
MOVING SHORTWAVE HAS THE POTENTIAL TO CREATE LOCALLY HEAVY
RAINFALL GIVEN WEAK 850-300MB STEERING FLOW AND MODELED GREATER THAN
150 PERCENT PRECIPITABLE WATER AMOUNTS. TEMPERATURES THROUGH THE
PERIOD WILL BE WITHIN 5 DEGREES OF THE AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 525 PM MDT WED AUG 13 2014
AN UPPER LEVEL DISTURBANCE WILL PUSH TOWARD THE REGION WITH
INCREASING CHANCES FOR SHRA/TS THROUGH THURSDAY. THERE IS A SLIGHT
CHANCE FOR ACTIVITY TONIGHT THROUGH THUR MORNING...WITH BETTER
CHANCES FOR SHRA/TS THUR AFTERNOON/EVENING OVER THE WESTERN 2/3.
VFR CONDITIONS WILL PREVAIL OUTSIDE OF ANY PRECIPITATION.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR SDZ001-002-012>014-024>032-041>044-072>074.
WY...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR WYZ054>058-071.
&&
$$
SHORT TERM...13
LONG TERM...10
AVIATION...JC
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1249 PM CDT TUE AUG 12 2014
.AVIATION...
LIGHT WINDS AND VFR CONDITIONS WILL CONTINUE THROUGH THE TAF
PERIOD. ISOLATED RW/TRW WILL PRIMARILY REMAIN WEST OF THE KLBB
TERMINAL AS UPPER HIGH BUILDS ACROSS THE REGION.
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT TUE AUG 12 2014/
SHORT TERM...
A FEW LINGERING SHOWERS SHOULD PUSH OUT OF THE FCST AREA BY FCST
VALID TIME AS MODEST UPPER LEVEL JET STREAKS EXITS TO THE EAST FROM
SRN OKLAHOMA. MODELS CONTINUE TO PROG DRIER LOW TO MID LEVEL AIR
ADVECTING INTO THE REGION...AND LOOKING AT WATER VAPOR IMAGERY AND
SFC OBS CANNOT REALLY DISPUTE THAT ATTM. LAST PLACE TO GET THE DRIER
AIR TODAY WILL BE THE SWRN CORNER OF THE FCST AREA WITH THE WRF-NAM
IN PARTICULAR. COULD SEE SOME ISOLATED SHOWERS DEVELOP THIS AFTN AS
THE AIR MASS THERE DESTABILIZES AS THE WRF-NAM AND HRRR SUGGEST.
CONFIDENCE IS LOW AND COVERAGE EXPECTED TO BE LIMITED ATTM SO WILL
KEEP POPS BELOW MENTION BUT WILL BE SOMETHING TO WATCH THROUGH THE
DAY. OTHERWISE TEMPS NOT TOO DIFFERENT THAN SEEN YESTERDAY AND IN
LINE OR JUST A DEGREE OR TWO BELOW MOS LOOKING FINE.
LONG TERM...
MODELS ARE IN GOOD AGREEMENT THROUGH THE END OF THE WEEK INTO THE
BEGINNING OF THE WEEKEND...PERSISTENT UPPER LEVEL RIDGE OVER THE
ROCKIES SLOWLY MIGRATES EASTWARD THROUGH THE WEEK RESULTING IN HIGH
PRESSURE ACROSS WEST TEXAS...BY SATURDAY A NUMBER OF UPPER LEVEL
DISTURBANCES BEGIN TO BREAK THE RIDGE DOWN DUE TO A NUMBER OF
SHORTWAVES EJECTING EASTWARD AND MONSOONAL FLOW OUT OF THE PACIFIC
WEST...GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT ON SATURDAY AT
120HRS...GFS WORKS THE UPPER LEVEL INSTABILITY EASTWARD QUICKER THAN
THE ECMWF WHICH DEVELOPS A CLOSED LOW OVER THE CENTRAL PLAINS
RESULTING IN COLD FRONT EXTENDING FROM CENTRAL KANSAS THROUGH WEST
TEXAS SATURDAY NIGHT INTO SUNDAY WHICH WAS HINTED AT IN PREVIOUS
RUNS...THUS INCREASED POPS SLIGHTLY TOWARD THE END OF THE WEEKEND
MAINTAINING SIMILAR TREND OF PREVIOUS FORECAST...KEPT TEMPS IN NEAR
SEASONAL TO SLIGHTLY COOLER...IF WE STAY DRY TEMPS MAY APPROACH THE
100S OFF THE CAPROCK BY THE END OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 90 64 90 64 / 10 10 0 0 10
TULIA 62 91 65 92 66 / 0 0 0 0 10
PLAINVIEW 62 91 65 91 66 / 0 0 0 0 10
LEVELLAND 64 91 66 92 66 / 0 0 0 0 10
LUBBOCK 65 93 69 93 67 / 0 0 0 0 10
DENVER CITY 64 92 66 92 66 / 10 0 0 0 10
BROWNFIELD 65 92 67 93 66 / 0 0 0 0 10
CHILDRESS 67 95 70 97 71 / 0 0 0 0 10
SPUR 65 94 68 95 70 / 0 0 0 0 10
ASPERMONT 67 96 70 96 71 / 0 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
06/99/99
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
559 AM CDT TUE AUG 12 2014
.AVIATION...
LIGHT WINDS AND VFR CONDITIONS ARE EXPECTED TODAY AND TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 350 AM CDT TUE AUG 12 2014/
SHORT TERM...
A FEW LINGERING SHOWERS SHOULD PUSH OUT OF THE FCST AREA BY FCST
VALID TIME AS MODEST UPPER LEVEL JET STREAKS EXITS TO THE EAST FROM
SRN OKLAHOMA. MODELS CONTINUE TO PROG DRIER LOW TO MID LEVEL AIR
ADVECTING INTO THE REGION...AND LOOKING AT WATER VAPOR IMAGERY AND
SFC OBS CANNOT REALLY DISPUTE THAT ATTM. LAST PLACE TO GET THE DRIER
AIR TODAY WILL BE THE SWRN CORNER OF THE FCST AREA WITH THE WRF-NAM
IN PARTICULAR. COULD SEE SOME ISOLATED SHOWERS DEVELOP THIS AFTN AS
THE AIR MASS THERE DESTABILIZES AS THE WRF-NAM AND HRRR SUGGEST.
CONFIDENCE IS LOW AND COVERAGE EXPECTED TO BE LIMITED ATTM SO WILL
KEEP POPS BELOW MENTION BUT WILL BE SOMETHING TO WATCH THROUGH THE
DAY. OTHERWISE TEMPS NOT TOO DIFFERENT THAN SEEN YESTERDAY AND IN
LINE OR JUST A DEGREE OR TWO BELOW MOS LOOKING FINE.
LONG TERM...
MODELS ARE IN GOOD AGREEMENT THROUGH THE END OF THE WEEK INTO THE
BEGINNING OF THE WEEKEND...PERSISTENT UPPER LEVEL RIDGE OVER THE
ROCKIES SLOWLY MIGRATES EASTWARD THROUGH THE WEEK RESULTING IN HIGH
PRESSURE ACROSS WEST TEXAS...BY SATURDAY A NUMBER OF UPPER LEVEL
DISTURBANCES BEGIN TO BREAK THE RIDGE DOWN DUE TO A NUMBER OF
SHORTWAVES EJECTING EASTWARD AND MONSOONAL FLOW OUT OF THE PACIFIC
WEST...GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT ON SATURDAY AT
120HRS...GFS WORKS THE UPPER LEVEL INSTABILITY EASTWARD QUICKER THAN
THE ECMWF WHICH DEVELOPS A CLOSED LOW OVER THE CENTRAL PLAINS
RESULTING IN COLD FRONT EXTENDING FROM CENTRAL KANSAS THROUGH WEST
TEXAS SATURDAY NIGHT INTO SUNDAY WHICH WAS HINTED AT IN PREVIOUS
RUNS...THUS INCREASED POPS SLIGHTLY TOWARD THE END OF THE WEEKEND
MAINTAINING SIMILAR TREND OF PREVIOUS FORECAST...KEPT TEMPS IN NEAR
SEASONAL TO SLIGHTLY COOLER...IF WE STAY DRY TEMPS MAY APPROACH THE
100S OFF THE CAPROCK BY THE END OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 87 61 90 64 90 / 10 10 10 0 0
TULIA 89 62 91 65 92 / 0 0 0 0 0
PLAINVIEW 87 62 91 65 91 / 0 0 0 0 0
LEVELLAND 88 64 91 66 92 / 10 0 0 0 0
LUBBOCK 90 65 93 69 93 / 10 0 0 0 0
DENVER CITY 87 64 92 66 92 / 10 10 0 0 0
BROWNFIELD 89 65 92 67 93 / 10 0 0 0 0
CHILDRESS 92 67 95 70 97 / 0 0 0 0 0
SPUR 91 65 94 68 95 / 10 0 0 0 0
ASPERMONT 94 67 96 70 96 / 10 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/55/07
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
350 AM CDT TUE AUG 12 2014
.SHORT TERM...
A FEW LINGERING SHOWERS SHOULD PUSH OUT OF THE FCST AREA BY FCST
VALID TIME AS MODEST UPPER LEVEL JET STREAKS EXITS TO THE EAST FROM
SRN OKLAHOMA. MODELS CONTINUE TO PROG DRIER LOW TO MID LEVEL AIR
ADVECTING INTO THE REGION...AND LOOKING AT WATER VAPOR IMAGERY AND
SFC OBS CANNOT REALLY DISPUTE THAT ATTM. LAST PLACE TO GET THE DRIER
AIR TODAY WILL BE THE SWRN CORNER OF THE FCST AREA WITH THE WRF-NAM
IN PARTICULAR. COULD SEE SOME ISOLATED SHOWERS DEVELOP THIS AFTN AS
THE AIR MASS THERE DESTABILIZES AS THE WRF-NAM AND HRRR SUGGEST.
CONFIDENCE IS LOW AND COVERAGE EXPECTED TO BE LIMITED ATTM SO WILL
KEEP POPS BELOW MENTION BUT WILL BE SOMETHING TO WATCH THROUGH THE
DAY. OTHERWISE TEMPS NOT TOO DIFFERENT THAN SEEN YESTERDAY AND IN
LINE OR JUST A DEGREE OR TWO BELOW MOS LOOKING FINE.
&&
.LONG TERM...
MODELS ARE IN GOOD AGREEMENT THROUGH THE END OF THE WEEK INTO THE
BEGINNING OF THE WEEKEND...PERSISTENT UPPER LEVEL RIDGE OVER THE
ROCKIES SLOWLY MIGRATES EASTWARD THROUGH THE WEEK RESULTING IN HIGH
PRESSURE ACROSS WEST TEXAS...BY SATURDAY A NUMBER OF UPPER LEVEL
DISTURBANCES BEGIN TO BREAK THE RIDGE DOWN DUE TO A NUMBER OF
SHORTWAVES EJECTING EASTWARD AND MONSOONAL FLOW OUT OF THE PACIFIC
WEST...GFS/ECMWF BEGIN TO DIVERGE SOMEWHAT ON SATURDAY AT
120HRS...GFS WORKS THE UPPER LEVEL INSTABILITY EASTWARD QUICKER THAN
THE ECMWF WHICH DEVELOPS A CLOSED LOW OVER THE CENTRAL PLAINS
RESULTING IN COLD FRONT EXTENDING FROM CENTRAL KANSAS THROUGH WEST
TEXAS SATURDAY NIGHT INTO SUNDAY WHICH WAS HINTED AT IN PREVIOUS
RUNS...THUS INCREASED POPS SLIGHTLY TOWARD THE END OF THE WEEKEND
MAINTAINING SIMILAR TREND OF PREVIOUS FORECAST...KEPT TEMPS IN NEAR
SEASONAL TO SLIGHTLY COOLER...IF WE STAY DRY TEMPS MAY APPROACH THE
100S OFF THE CAPROCK BY THE END OF THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 90 64 90 64 / 10 10 0 0 10
TULIA 62 91 65 92 66 / 0 0 0 0 10
PLAINVIEW 62 91 65 91 66 / 0 0 0 0 10
LEVELLAND 64 91 66 92 66 / 0 0 0 0 10
LUBBOCK 65 93 69 93 67 / 0 0 0 0 10
DENVER CITY 64 92 66 92 66 / 10 0 0 0 10
BROWNFIELD 65 92 67 93 66 / 0 0 0 0 10
CHILDRESS 67 95 70 97 71 / 0 0 0 0 10
SPUR 65 94 68 95 70 / 0 0 0 0 10
ASPERMONT 67 96 70 96 71 / 0 0 0 0 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07/55
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1053 PM CDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. WEAK SHORTWAVE ON THE BACKSIDE OF THE TROUGH
PUSHING SOUTH INTO THE GREAT LAKES PRODUCING CUMULUS CLOUDS ACROSS
THE UPPER GREAT LAKES REGION PER LATEST VISIBLE SATELLITE IMAGERY.
LATEST 19Z SURFACE ANALYSIS INDICATES WEAK COLD FRONT EXTENDING FROM
MICHIGAN INTO WESTERN WISCONSIN AND SURFACE RIDGE OVER ONTARIO AND
SASKATCHEWAN CANADA.
MAIN FORECAST CONCERNS TONIGHT IS FOG POTENTIAL IN RIVER VALLEYS
AND THE FAVORED AREAS IN CENTRAL WISCONSIN.
SURFACE RIDGE OVER SOUTHERN CANADA BUILDS INTO THE FORECAST AREA
TONIGHT. THIS WILL PROVIDE MOSTLY CLEAR SKIES AND CALM WINDS. THE
LATEST 13.12Z GFS/NAM AND 13.15Z RAP BUFKIT SOUNDINGS SHOW AN
INVERSION TO DEVELOP AFTER 06Z AND WINDS ABOVE THE SURFACE TO BE 10
TO 20 KNOTS. IN ADDITION...WITH A DRIER AIRMASS ADVECTING IN AND
NORTHERLY WIND COMPONENT OVERHEAD AND NEAR THE SURFACE. FOG
FORMATION WILL BE HARD TO DEVELOP IN RIVER VALLEYS AND FAVORED AREAS
IN CENTRAL WISCONSIN. HAVE REMOVED PATCHY FOG IN THESE AREAS FOR
TONIGHT.
SURFACE RIDGE WILL REMAIN IN CONTROL OF THE AREA THURSDAY AND
PRODUCE MOSTLY SUNNY SKIES AND DRY WEATHER CONDITIONS ACROSS THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
UPPER LEVEL CLOSED LOW OVER THE PACIFIC NORTHWEST EJECTS OUT A PIECE
OF ENERGY INTO THE UPPER MIDWEST AND FLATTENS UPPER LEVEL RIDGE
FRIDAY INTO SATURDAY. THE DPROG/DT OF THE 13.12Z GFS/NAM INDICATES
THIS PIECE OF ENERGY MOVING INTO THE REGION SLIGHTLY FASTER. THE
13.12Z ECMWF IS SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH
INTO THE UPPER MIDWEST. THE 13.12Z MODELS SHOW INCREASING
LIFT/FORCING AND MOISTURE INTO THE WESTERN HALF OF THE FORECAST AREA
AFTER 18Z FRIDAY. THE 13.12Z GFS/NAM BUFKIT SOUNDINGS SHOW DRY
AIRMASS ALOFT OVER THE FORECAST AREA DURING THE DAY FRIDAY. THIS
COULD INHIBIT PRECIPITATION MOVING INTO THE AREA. FOR NOW...KEPT
SMALL PRECIPITATION CHANCES ACROSS THE FORECAST AREA.
LIFT/FORCING AND MOISTURE INCREASES ACROSS MUCH OF THE FORECAST AREA
AFTER 00Z SATURDAY AND CONTINUES THROUGH MUCH OF THE DAY
SATURDAY...ESPECIALLY OVER THE SOUTHERN HALF OF THE FORECAST AREA.
HAVE INCREASED PRECIPITATION CHANCES ACROSS THIS PART OF THE
FORECAST AREA.
AT THIS TIME...SEVERE WEATHER THREATS LOOKS LOW...AS THE 13.12Z
GFS/NAM BUILD MINIMAL SURFACE BASED CAPE AND BUILD ELEVATED CAPE
OVER THE FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
MIDDLE OF NEXT WEEK. THE 13.12Z GFS/ECMWF/GEM CONTINUE TO DEVELOP
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES
SATURDAY NIGHT INTO MONDAY. THE 13.12Z GFS/ECMWF/GEM DIFFER
SIGNIFICANTLY ON TIMING AND PLACEMENT OF SHORTWAVE TROUGHS/SURFACE
FEATURES THROUGH MUCH OF THE TIME PERIOD...WHERE THE 13.12Z GFS IS
MORE PROGRESSIVE AND FARTHER SOUTH WITH SHORTWAVE TROUGH/SURFACE
FEATURES SUNDAY INTO MONDAY THAN THE 13.12Z GEM/ECMWF. BASED ON
THE DIFFERENCES IN TIMING AND PLACEMENT WITH SHORTWAVE ENERGY
THROUGH THIS TIME PERIOD...CONFIDENCE IN FORECAST REMAINS LOW AND
WILL KEEP PRECIPITATION CHANCES THROUGH EARLY OF NEXT WEEK. THE
UNSETTLED WEATHER PATTERN WILL CONTINUE INTO MIDDLE OF NEXT
WEEK...AS THE 13.12Z GFS/ECMWF ARE HINTING AT WEST TO
SOUTHWESTERLY FLOW ALOFT TO DEVELOP OVER THE ROCKY MOUNTAINS AND
CENTRAL UNITED STATES. THE 13.12Z GFS/ECMWF INDICATE AN IMPULSE TO
EJECT OUT INTO THE CENTRAL UNITED STATES WEDNESDAY. HOWEVER...WITH
TIMING AND PLACEMENT ISSUES IN ASSOCIATION WITH THE SHORTWAVE
TROUGH/SURFACE FEATURES...REGION COULD SEE A BREAK IN
PRECIPITATION CHANCES WEDNESDAY. TEMPERATURES THROUGH MUCH OF THE
PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1055 PM CDT WED AUG 13 2014
VFR CONDITIONS THROUGH THE PERIOD. TEMPERATURE AND DEWPOINT SPREAD
AT KLSE STILL A LARGE 14F AT 03Z. THIS AND SLIGHT NORTHEAST WIND
FLOW ON THE RIDGE AT THE NWS OFFICE EAST OF THE AIRFIELD /MIXING/ SUPPORT
GOING TAF FORECAST WITH NO VALLEY FOG INCLUSION FOR 06Z TAFS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
638 PM CDT WED AUG 13 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. WEAK SHORTWAVE ON THE BACKSIDE OF THE TROUGH
PUSHING SOUTH INTO THE GREAT LAKES PRODUCING CUMULUS CLOUDS ACROSS
THE UPPER GREAT LAKES REGION PER LATEST VISIBLE SATELLITE IMAGERY.
LATEST 19Z SURFACE ANALYSIS INDICATES WEAK COLD FRONT EXTENDING FROM
MICHIGAN INTO WESTERN WISCONSIN AND SURFACE RIDGE OVER ONTARIO AND
SASKATCHEWAN CANADA.
MAIN FORECAST CONCERNS TONIGHT IS FOG POTENTIAL IN RIVER VALLEYS
AND THE FAVORED AREAS IN CENTRAL WISCONSIN.
SURFACE RIDGE OVER SOUTHERN CANADA BUILDS INTO THE FORECAST AREA
TONIGHT. THIS WILL PROVIDE MOSTLY CLEAR SKIES AND CALM WINDS. THE
LATEST 13.12Z GFS/NAM AND 13.15Z RAP BUFKIT SOUNDINGS SHOW AN
INVERSION TO DEVELOP AFTER 06Z AND WINDS ABOVE THE SURFACE TO BE 10
TO 20 KNOTS. IN ADDITION...WITH A DRIER AIRMASS ADVECTING IN AND
NORTHERLY WIND COMPONENT OVERHEAD AND NEAR THE SURFACE. FOG
FORMATION WILL BE HARD TO DEVELOP IN RIVER VALLEYS AND FAVORED AREAS
IN CENTRAL WISCONSIN. HAVE REMOVED PATCHY FOG IN THESE AREAS FOR
TONIGHT.
SURFACE RIDGE WILL REMAIN IN CONTROL OF THE AREA THURSDAY AND
PRODUCE MOSTLY SUNNY SKIES AND DRY WEATHER CONDITIONS ACROSS THE
FORECAST AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 254 PM CDT WED AUG 13 2014
UPPER LEVEL CLOSED LOW OVER THE PACIFIC NORTHWEST EJECTS OUT A PIECE
OF ENERGY INTO THE UPPER MIDWEST AND FLATTENS UPPER LEVEL RIDGE
FRIDAY INTO SATURDAY. THE DPROG/DT OF THE 13.12Z GFS/NAM INDICATES
THIS PIECE OF ENERGY MOVING INTO THE REGION SLIGHTLY FASTER. THE
13.12Z ECMWF IS SLOWER WITH THE PROGRESSION OF THE SHORTWAVE TROUGH
INTO THE UPPER MIDWEST. THE 13.12Z MODELS SHOW INCREASING
LIFT/FORCING AND MOISTURE INTO THE WESTERN HALF OF THE FORECAST AREA
AFTER 18Z FRIDAY. THE 13.12Z GFS/NAM BUFKIT SOUNDINGS SHOW DRY
AIRMASS ALOFT OVER THE FORECAST AREA DURING THE DAY FRIDAY. THIS
COULD INHIBIT PRECIPITATION MOVING INTO THE AREA. FOR NOW...KEPT
SMALL PRECIPITATION CHANCES ACROSS THE FORECAST AREA.
LIFT/FORCING AND MOISTURE INCREASES ACROSS MUCH OF THE FORECAST AREA
AFTER 00Z SATURDAY AND CONTINUES THROUGH MUCH OF THE DAY
SATURDAY...ESPECIALLY OVER THE SOUTHERN HALF OF THE FORECAST AREA.
HAVE INCREASED PRECIPITATION CHANCES ACROSS THIS PART OF THE
FORECAST AREA.
AT THIS TIME...SEVERE WEATHER THREATS LOOKS LOW...AS THE 13.12Z
GFS/NAM BUILD MINIMAL SURFACE BASED CAPE AND BUILD ELEVATED CAPE
OVER THE FORECAST AREA.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES SATURDAY NIGHT INTO
MIDDLE OF NEXT WEEK. THE 13.12Z GFS/ECMWF/GEM CONTINUE TO DEVELOP
WEST TO EAST ZONAL FLOW ACROSS THE CONTINENTAL UNITED STATES
SATURDAY NIGHT INTO MONDAY. THE 13.12Z GFS/ECMWF/GEM DIFFER
SIGNIFICANTLY ON TIMING AND PLACEMENT OF SHORTWAVE TROUGHS/SURFACE
FEATURES THROUGH MUCH OF THE TIME PERIOD...WHERE THE 13.12Z GFS IS
MORE PROGRESSIVE AND FARTHER SOUTH WITH SHORTWAVE TROUGH/SURFACE
FEATURES SUNDAY INTO MONDAY THAN THE 13.12Z GEM/ECMWF. BASED ON
THE DIFFERENCES IN TIMING AND PLACEMENT WITH SHORTWAVE ENERGY
THROUGH THIS TIME PERIOD...CONFIDENCE IN FORECAST REMAINS LOW AND
WILL KEEP PRECIPITATION CHANCES THROUGH EARLY OF NEXT WEEK. THE
UNSETTLED WEATHER PATTERN WILL CONTINUE INTO MIDDLE OF NEXT
WEEK...AS THE 13.12Z GFS/ECMWF ARE HINTING AT WEST TO
SOUTHWESTERLY FLOW ALOFT TO DEVELOP OVER THE ROCKY MOUNTAINS AND
CENTRAL UNITED STATES. THE 13.12Z GFS/ECMWF INDICATE AN IMPULSE TO
EJECT OUT INTO THE CENTRAL UNITED STATES WEDNESDAY. HOWEVER...WITH
TIMING AND PLACEMENT ISSUES IN ASSOCIATION WITH THE SHORTWAVE
TROUGH/SURFACE FEATURES...REGION COULD SEE A BREAK IN
PRECIPITATION CHANCES WEDNESDAY. TEMPERATURES THROUGH MUCH OF THE
PERIOD WILL BE NEAR NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 638 PM CDT WED AUG 13 2014
FORECAST IS FOR VFR CONDITIONS THROUGH THE PERIOD. HOWEVER...THERE
ISNT A TIME THAT CLEAR SKIES AND LIGHT WINDS IN AUGUST OR
SEPTEMBER DOESNT CAUSE SOME PAUSE FOR THE DEVELOPMENT OF RIVER
VALLEY FOG AT KLSE AT SUNRISE. WHILE THERE SEEMS TO BE A
PREDOMINANCE OF FORECAST MODEL GUIDANCE THAT SUGGESTS WINDS ABOVE
THE SURFACE WILL BE TOO HIGH /OVER 10KTS/ ABOVE THE
SURFACE...THERE ARE SOME SOLUTIONS THAT ARE MORE FAVORABLE FOR FOG
/LIGHTER WINDS TO 5KFT/. JUST NORTH AND NORTHEAST OF KLSE AT
23Z...DEWPOINTS ARE ABOUT 5F LOWER AND WITH A LIGHT NORTHEAST
WIND...THAT AIR SHOULD MOVE OVER THE AIRFIELD OVERNIGHT...MAKING
IT MORE DIFFICULT FOR FOG FORMATION.
WILL CONTINUE TO MONITOR FOR FOG POSSIBILITIES IN THE
MORNING...BUT AT THIS TIME IT LOOKS LIKE IT WOULD ONLY BE PATCHY
IN THE RIVER VALLEY AND A MINOR IMPACT IF ANY TO AVIATION SHOULD
IT FORM NEAR KLSE. IT HAS NOT BEEN INCLUDED IN THE LATEST TAF
FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
636 AM CDT TUE AUG 12 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 12 2014
MAIN FORECAST CONCERNS...VALLEY FOG LATE TONIGHT...TEMPERATURES.
DATA ANALYSIS AT 06Z HAD A 1003MB LOW OVER EASTERN LOW MI AND HIGH
PRESSURE OVER THE CENTRAL/NORTHERN PLAINS. CLOUDS MAINLY CONFINED TO
THE EAST HALF OF WI/NORTH-EAST IL...WITH SHRA PERSISTING OVER
NORTHEAST WI AHEAD OF THE MID LEVEL THROUGH/SHORTWAVE. DECREASING
CLOUDS/CLEAR SKIES ELSEWHERE ACROSS THE UPPER MIDWEST AS THE PLAINS
HIGH SLOWLY MOVED EAST. MODEST PRESSURE GRADIENT BETWEEN THE
LOW/HIGH ACROSS MUCH OF MN/IA/WI EARLY THIS MORNING WITH NORTHWEST
WINDS OF 5-15 MPH COMMON...KEEPING THE BOUNDARY LAYER STIRRED...
LIMITING THE TEMP DROP AND FOG FORMATION.
12.00Z MODELS INITIALIZED WELL AND OFFER QUITE SIMILAR SOLUTIONS FOR
TODAY/TONIGHT AS THE STRONG MID LEVEL TROUGH EXITS EAST AND HGTS
SLOWLY RISE ACROSS THE WESTERN GREAT LAKES REGION. TREND FAVORS A
COMPROMISE OF THE EARLIER RUNS WITH FCST CONFIDENCE ON THE GOOD SIDE
FOR TODAY/TONIGHT...AS QUIET/COOL/DRIER CANADIAN HIGH PRESSURE
BUILDS IN.
IN THE SHORT TERM...A GENERALLY QUIET PERIOD TODAY/TONIGHT AS THE
HIGH IN THE PLAINS SLOWLY MOVES EAST INTO THE REGION. MODEST
PRESSURE GRADIENT REMAINS OVER THE AREA TODAY. MODEL SOUNDINGS SHOW
DIURNAL WARMING/MIXING TO AROUND 825MB WITH 20-25KTS OF WIND IN THE
UPPER THIRD OF THIS MIXED LAYER. ADDED A BIT MORE WIND/WIND GUSTS TO
THE FCST GRIDS FOR THE LATE MORNING/AFTERNOON HOURS TODAY. MODELS DO
DIFFER ON AMOUNT OF MOISTURE IN THE MIXED LAYER...IMPACTING EXTENT
OF DIURNAL CUMULUS. SOME WOULD SAY TOO DRY FOR DIURNAL CUMULUS WHILE
OTHERS WOULD DEVELOP A SCT LCL BKN CUMULUS DECK. BASED ON THE 12.00Z
KINL/KMPX RAOBS AND UPSTREAM SFC DEW POINTS DROPPING INTO THE LOWER
50S...SIDED WITH THE DRIER MODELS AND A FEW CUMULUS AT MOST TODAY.
COOLEST OF THE 850MB AIR SLIDES ACROSS THE AREA TODAY. MIXED 850MB
TEMPS AND PLENTY OF SUNSHINE SUPPORT HIGHS IN THE MID-UPPER 70S.
GRADIENT RELAXES TONIGHT AS THE HIGH MOVES INTO MO/IA...ENOUGH FOR
SOME DECOUPLING IN THE RIVER VALLEYS/LOW LAYING AREAS LATER TONIGHT.
MODEL SOUNDINGS HAVE TRENDED MORE TOWARD 10-15KTS OF NORTHWEST WIND
JUST ABOVE THE BOUNDARY LAYER LATER TONIGHT...LESS FAVORABLE FOR
VALLEY FOG FORMATION IN THE MS RIVER VALLEY. WITH A DEEP DRY AIRMASS
OVER THE REGION AND SUBSIDENCE THRU THE MID/UPPER LEVELS...FAVORABLE
FOR STRONGER RADIATIONAL COOLING...WILL LEAVE THE PATCHY TO AREAS OF
VALLEY FOG LATER TONIGHT IN THE GRIDS FOR NOW. GIVEN THE STRONGER
RADIATIONAL COOLING POTENTIAL...TRENDED TOWARD COOLER OF GUIDANCE
LOWS TONIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 12 2014
MAIN FORECAST CONCERNS FOR WED THROUGH THU NIGHT...SMALL SHRA/TSRA
CHANCES WED AFTERNOON...TEMPERATURES.
MODELS REMAIN IN RATHER GOOD AGREEMENT WED THRU THU NIGHT AS A MID
LEVEL LOW DEVELOPS OVER WESTERN QUEBEC AND ANOTHER MID LEVEL LOW
MOVES INTO OR/WA...WITH RIDGING IN BETWEEN ACROSS CENTRAL NOAM. SOME
DETAIL DIFFERENCES WITH SHORTWAVES COMING OUT OF THE OR/WA TROUGHING
BY THU/THU NIGHT. HOWEVER THE UPPER MIDWEST REMAINS EAST OF THE
RIDGE AXIS AND UNDER MAINLY QUIET NORTHWEST FLOW ALOFT THRU THU
NIGHT. FCST CONFIDENCE IN THE WED THRU THU NIGHT PERIOD IS GOOD.
RATHER CONSISTENT MODEL SIGNAL FOR SHORTWAVE ENERGY DROPPING ACROSS
LK SUPERIOR ON WED TO SEND A /BACKDOOR/ COLD FRONT SOUTHWARD THRU
THE AREA. TROUGH AT 925-850MB AS WELL. PW VALUES PROGGED TO INCREASE
TO AROUND 1 INCH WITH MODEST SFC-850MB FN CONVERGENCE TO ACCOMPANY
THIS FEATURE. SOME 850-700MB FN CONVERGENCE AS WELL. MODEL PROGS
SHOWING AS MUCH AS 250-1000 J/KG OF MUCAPE ACROSS THE AREA WED
AFTERNOON. HOWEVER MODEL SOUNDINGS INDICATE MUCH LESS CAPE...MORE IN
THE 50-200 J/KG RANGE...WITH POTENTIAL CAPPING AROUND 700MB. BULK OF
MODELS INCLUDING HI-RES WRF MODELS CONTINUE TO PRODUCE SOME VERY
LIGHT QPF ACROSS THE AREA WITH THIS BOUNDARY/TROUGH WED AFTERNOON.
GIVEN THIS...WILL LEAVE THE SPRINKLE MENTION IN THE GRIDS FOR NOW.
MAY YET NEED TO SHIFT ANY SMALL -SHRA CHANCE WED AFTERNOON FURTHER
SOUTH/WEST ACROSS THE FCST AREA DEPENDING ON WHERE THE BOUNDARY IS
DURING PEAK HEATING.
WED NIGHT THRU THU NIGHT TREND DRY/QUIET. THIS WITH THE AREA
REMAINING EAST OF THE MID LEVEL RIDGE AXIS AND STRONGER PIECES OF
ENERGY EJECTING OUT OF THE NORTHWEST CONUS TROUGH ONLY INTO THE
CENTRAL/NORTHERN PLAINS BY 12Z FRI. BOUNDARY FROM WED SAGS SOUTH OF
THE AREA/DISSIPATES WED NIGHT WITH HIGH PRESSURE AGAIN BUILDING OVER
THE WESTERN GREAT LAKES FOR WED NIGHT THRU THU NIGHT. WITH HIGH
PRESSURE CENTERED OVER WI BY 12Z THU FOR LIGHT/CALM WINDS AND
CLEAR/MOSTLY CLEAR SKIES...ADDED A PATCHY VALLEY FOG MENTION TO
GRIDS FOR LATE WED NIGHT/EARLY THU MORNING. LOWER LEVEL THERMAL
RIDGE AND MAIN AXIS OF MOISTURE/MOISTURE TRANSPORT/INSTABILITY REMAIN
WEST OF THE AREA THRU THU NIGHT. REMOVED THE SMALL SHRA/TSRA CHANCES
FROM THU NIGHT. BLEND OF THE NUMERICAL TEMPERATURE GUIDANCE FOR WED
THRU THU NIGHT LOOKS TO HAVE HIGHS/LOWS WELL TRENDED.
FOR FRIDAY THROUGH MONDAY.../DAYS 4 TO 7/...
MAIN FORECAST CONCERNS...SHRA/TSRA CHANCES THRU MUCH OF THE
PERIOD...TEMPERATURES.
12.00Z MEDIUM RANGE MODEL CONSENSUS SHOWS A BREAK-DOWN OF THE
CENTRAL NOAM RIDGING IN THE FRI-SUN PERIOD. FIRST AS SHORTWAVE
ENERGY EJECTING OUT OF THE NORTHWEST CONUS TROUGH COMES THRU IT
FRI/SAT THEN AS THE NORTHWEST CONUS TROUGH/REMNANTS MOVE EAST
SUN/MON. PLENTY OF DETAIL DIFFERENCES BY FRI/SAT...WHICH WOULD HAVE
IMPACTS ON THE SENSIBLE WEATHER ACROSS MN/IA/WI. DIFFERENCES
CONTINUE SUN/MON. OVERALL DAY-TO-DAY FCST CONFIDENCE IN THE FRI-MON
PERIOD IS BELOW AVERAGE...FOR WHAT LOOKS TO BE A MORE ACTIVE/
UNSETTLED PERIOD.
LEAD SHORTWAVE/S/ COMING THRU THE RIDGING PUSH THE MOISTURE AXIS/
INSTABILITY EASTWARD INTO THE REGION FRI. PW VALUES INCREASE INTO
THE 1.5 INCH RANGE FRI WITH MUCAPE IN THE 500-1500 J/KG RANGE FOR
THE AFTERNOON. CONCERN IS LACK OF TRIGGER/FOCUS MECHANISM FOR
CONVECTION. LEFT MOST OF THE AREA DRY FRI. MOISTURE CONTINUES TO
SLOWLY INCREASE FOR SAT THRU MON...WITH CONTINUED APPROACH OF PIECES
OF SHORTWAVE ENERGY AND GRADUALLY FALLING HGTS. SHRA/TSRA CHANCES
LOOK TO SLOWLY INCREASE FOR SAT THRU MON AND THIS WELL TRENDED BY
THE MODEL/ENSEMBLE CONSENSUS. AGAIN...PLENTY OF DETAIL DIFFERENCES
WITH SHORTWAVES AND TIMING THRU THIS PERIOD...AND NOT EVERY FRI
NIGHT THRU MON PERIOD WILL END UP WITH SHRA/TSRA CHANCES ONCE
THESE DIFFERENCES SORT THEMSELVES OUT. WITH A RETURN TO MORE
SOUTHERLY FLOW/LOW LEVEL WARMING...MODEL CONSENSUS HIGHS/LOWS NEAR
TO ABOVE NORMAL FOR FRI-MON APPEAR WELL TRENDED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 625 AM CDT TUE AUG 12 2014
LOW STRATUS/PATCHY ADVECTION FOG ACROSS NORTHWEST WI IS OOZING
SOUTHWARD ALONG THE ST. CROIX RIVER VALLEY AND INTO SOUTHEAST
MN IMPACTING KRST. 12.10Z RAP SUGGESTS THESE CLOUDS/FOG SHOULD
QUICKLY DISSIPATE BY 14Z AND WILL ADJUST TAF TO ACCOUNT FOR THESE
TRENDS. FARTHER EAST AT KLSE...NOT EXPECTING WIDESPREAD LOWER
CEILINGS WITH SCATTERED CLOUD BASES AROUND 1200 FT AGL.
FOR THE REST OF THE FORECAST PERIOD...EXPECT SOME AFTERNOON
THERMAL CUMULUS IN THE 3000 TO 4000 FT AGL LAYER. NORTHWEST WIND
WILL BE BREEZY WITH OCCASIONAL GUSTS TO 25 KTS. WINDS WILL BECOME
LIGHT AND VARIABLE AFTER SUNSET WITH THE POTENTIAL FOR VALLEY FOG
DEVELOPMENT AT KLSE AFTER 13.08Z DUE TO NEAR SURFACE SATURATION...
STEEP NOCTURNAL THERMAL INVERSION AND LIGHT WIND.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
327 AM EDT THU AUG 14 2014
.DISCUSSION...
TODAY-TONIGHT...AS IT HAS BEEN FOR AROUND THE PAST WEEK...THERE
REMAINS VERY LITTLE CHANGE IN THE LARGER SYNOPTIC PATTERN IN PLACE
ACROSS THE STATE. DEEP TROUGH ACROSS THE NORTHEASTERN US KEEPS THE
ATLANTIC RIDGE AXIS SUPPRESSED TO OUR SOUTH...TODAY REMAINING SOUTH
OF THE STATE ACROSS THE FLORIDA STRAITS.
OVERALL GRADIENT LOOKS WEAKER TODAY LEADING TO LIGHTER
WEST-SOUTHWEST FLOW. THIS SHOULD ALLOW FOR SLIGHTLY FASTER...AND
MORE EXPANSIVE...DEVELOPMENT OF THE EAST COAST SEA BREEZE AND THIS
IS REFLECTED IN THE LOCAL HRRR AND WRF. EVEN THE GFS AND ECMWF HINT
AT A SEA BREEZE ALONG THE TREASURE COAST. HOWEVER STILL DON`T EXPECT
MUCH INLAND PENETRATION MUCH PAST THE IMMEDIATE COAST OR WEST SIDE
OF THE INDIAN RIVER LAGOON.
CENTRAL FLORIDA WILL BE MORE SOLIDLY UNDER THE INFLUENCE OF THE
LOW-MID LEVEL MOISTURE LEFT BEHIND BY THE SURFACE FRONT THAT DIED
OUT TO OUR NORTH EARLIER THIS WEEK. WHILE THIS SHOULD LEAD TO A
LITTLE BETTER COVERAGE...OVERALL CONVECTIVE EVOLUTION REMAINS
SIMILAR WITH STORMS ALONG THE WEST COAST SEA BREEZE PUSHING EAST
THROUGH THE AFTERNOON. ISOLATED SHOWERS AND STORMS WILL ALSO BE
POSSIBLE ALONG THE EAST COAST SEA BREEZE WHERE IT DOES DEVELOP
BEFORE THE EASTWARD MOVING CONVECTION REACHES IT. COVERAGE WILL
INCREASE THROUGH THE AFTERNOON DUE TO VARIOUS BOUNDARY COLLISIONS.
AS IN PREVIOUS LATE AFTERNOONS AND EVENINGS STORMS TO END AROUND
SUNSET...LOSS OF DAYTIME HEATING AND BOUNDARY COLLISIONS SLOWING
DOWN AND ENDING LATE EVENING. LOW AND MID LEVEL DEBRIS CLOUDS
DISSIPATE AND SKIES TO BECOME PARTLY CLOUDY TO MOSTLY CLEAR LATE
NIGHT.
FRIDAY-SATURDAY...HIGHER RAIN CHANCES WILL CONTINUE INTO THE START
OF THE UPCOMING WEEKEND WITH WSW LOW LVL FLOW AND DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES AROUND TWO INCHES OR GREATER INTO SATURDAY
ACROSS EAST CENTRAL FL AHEAD OF A STALLED FRONTAL BOUNDARY ACROSS S
GA AND FL PANHANDLE. MID LVL IMPULSES ARE PROGGED TO MOVE ACROSS THE
NRN FLORIDA PENINSULA FRIDAY INTO SATURDAY WHICH WILL PROVIDE
ADDITIONAL ORGANIZATION FOR STORM DEVELOPMENT BY LATE MORNING INTO
THE AFTERNOON EACH DAY. SHOULD SEE A LATE AFTERNOON SEA BREEZE NEAR
THE COAST EACH AFTERNOON BUT IT IS NOT EXPECTED TO PUSH VERY FAR
INLAND. SHOWER AND THUNDERSTORM CHANCES WILL BE AROUND 50 PCT WITH
HIGH TEMPERATURES AROUND 90/LWR 90S NEAR THE COAST TO LWR-MID 90S
OVER THE INTERIOR. LOWS WILL BE IN THE 70S.
SUNDAY...THE LOW LVL RIDGE AXIS WILL BEGIN TO LIFT NORTHWARD TWD
LAKE OKEECHOBEE WITH LIGHTER LOW LVL WINDS ACROSS SRN SECTIONS AND
LIGHT SW FLOW ACROSS THE NORTH. OVERALL MOISTURE LEVELS WILL BE ON
THE DECREASE WITH THE MID LVL RIDGE STARTING TO BUILD OVER SRN
SECTIONS. THIS SHOULD LOWER RAINFALL CHANCES INTO THE LOWER CHANCE
CATEGORY FROM 30-40 PCT WITH THE HIGHER CHANCES ACROSS INTERIOR
SECTIONS IN THE AFTERNOON. ANOTHER HOT AFTERNOON WITH HIGHS IN THE
LOWER 90S COAST TO MID 90S INTERIOR.
MON-WED...THE GFS HAS BACKED OFF ON DEEPER MOISTURE MAKING IT TO THE
AREA WITH PRONOUNCED DRYING PROGGED NEAR THE LOW-MID LYR RIDGE AXIS
WHICH WILL BE LIFTING TWD E CENTRAL FL EARLY NEXT WEEK. THE 00Z
ECMWF IS ALSO SHOWING THE DRYING TREND WITH DECREASING MOISTURE IN
THE H8-H5 LAYER BY MON-TUE. HAVE LOWERED RAIN CHANCES TO THE 20-30
PCT RANGE MON-WED OF NEXT WEEK WITH HIGHER CHANCES ACROSS INTERIOR
SECTIONS LATE IN THE DAY WITH SEA BREEZE INTERACTIONS. IT WILL
CONTINUE HOT WITH HIGHS IN THE LOWER 90S ALONG THE COAST AND MID 90S
OVER THE INTERIOR. LOWS WILL BE IN THE 70S.
&&
.AVIATION...
PREVAILING VFR THROUGH 15Z. ISOLD TSRA DEVELOPING ACROSS REGION
AFTER 16Z...WITH SCT TSRA MOVING FROM WEST TO EAST ACROSS STATE WITH
WEST COAST SEA BREEZE THROUGH AFTERNOON. EAST COAST SEA BREEZE
DEVELOPING AFTER 17Z...REACHING KFPR/KSUA/KCOF...BUT LIKELY
REMAINING JUST EAST OF KVRB/KMLB/KTIX. BEST COVERAGE OF TSRA ALONG
COAST...WITH A FEW PRODUCING G35KTS ESPECIALLY WHERE THEY COLLIDE
WITH EAST COAST SEA BREEZE FROM KXMR SOUTHWARDS ALONG IMMEDIATE
COAST.
&&
.MARINE...
TODAY-TONIGHT...PREVAILING SOUTHWEST FLOW CONTINUES THROUGH THE
PERIOD AS RIDGE AXIS REMAINS WELL TO THE SOUTH ACROSS THE FLORIDA
STRAITS. 10-15KTS THROUGH MID MORNING BECOMING SOUTH-SOUTHWEST
5-10KTS INTO THE AFTERNOON. LIGHTER FLOW SHOULD ALLOW MORE OF AN
EAST COAST SEA BREEZE WITH WINDS NEARSHORE SOUTH OF THE CAPE
BECOMING SOUTH-SOUTHEAST DURING THE AFTERNOON. SEAS 1-2FT WITH UP TO
3 FT WELL OFFSHORE. DOMINANT PERIODS STILL A SOMEWHAT CHOPPY
3-5SEC...MIXED WITH 8-10SEC.
BOATERS ON THE INTRACOASTAL AND NEARSHORE WATERS SHOULD KEEP AN EYE
TO THE WEST FOR APPROACHING STORMS AND SEEK SAFE HARBOR TO RIDE OUT
THE STORMS.
SW-S WINDS TO 10 TO 15 KNOTS FRI-SAT WITH OFFSHORE MOVING SHOWERS
AND LIGHTNING STORMS. THE SFC RIDGE WILL BUILD NWD TWD THE SRN
WATERS EARLY NEXT WEEK WITH S WINDS ACROSS THE SRN WATERS AND SW
WINDS NORTH OF THE CAPE. SEAS 1-2 FT NEAR SHORE TO 2-3 FT OFFSHORE.
SHOULD SEE A LOWER COVERAGE OF SHOWER/STORMS AFFECTING THE ATLC
SUNDAY INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 76 90 76 / 50 30 50 30
MCO 95 76 92 75 / 50 30 50 30
MLB 92 75 90 76 / 50 30 50 30
VRB 92 75 91 75 / 50 30 50 30
LEE 94 77 93 77 / 50 30 50 20
SFB 95 77 93 77 / 50 30 50 30
ORL 94 77 94 78 / 50 30 50 30
FPR 91 74 91 75 / 50 30 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...MOSES
LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
320 AM EDT THU AUG 14 2014
.DISCUSSION...
TODAY-TONIGHT...AS IT HAS BEEN FOR AROUND THE PAST WEEK...THERE
REMAINS VERY LITTLE CHANGE IN THE LARGER SYNOPTIC PATTERN IN PLACE
ACROSS THE STATE. DEEP TROUGH ACROSS THE NORTHEASTERN US KEEPS THE
ATLANTIC RIDGE AXIS SUPPRESSED TO OUR SOUTH...TODAY REMAINING SOUTH
OF THE STATE ACROSS THE FLORIDA STRAITS.
OVERALL GRADIENT LOOKS WEAKER TODAY LEADING TO LIGHTER
WEST-SOUTHWEST FLOW. THIS SHOULD ALLOW FOR SLIGHTLY FASTER...AND
MORE EXPANSIVE...DEVELOPMENT OF THE EAST COAST SEA BREEZE AND THIS
IS REFLECTED IN THE LOCAL HRRR AND WRF. EVEN THE GFS AND ECMWF HINT
AT A SEA BREEZE ALONG THE TREASURE COAST. HOWEVER STILL DON`T EXPECT
MUCH INLAND PENETRATION MUCH PAST THE IMMEDIATE COAST OR WEST SIDE
OF THE INDIAN RIVER LAGOON.
CENTRAL FLORIDA WILL BE MORE SOLIDLY UNDER THE INFLUENCE OF THE
LOW-MID LEVEL MOISTURE LEFT BEHIND BY THE SURFACE FRONT THAT DIED
OUT TO OUR NORTH EARLIER THIS WEEK. WHILE THIS SHOULD LEAD TO A
LITTLE BETTER COVERAGE...OVERALL CONVECTIVE EVOLUTION REMAINS
SIMILAR WITH STORMS ALONG THE WEST COAST SEA BREEZE PUSHING EAST
THROUGH THE AFTERNOON. ISOLATED SHOWERS AND STORMS WILL ALSO BE
POSSIBLE ALONG THE EAST COAST SEA BREEZE WHERE IT DOES DEVELOP
BEFORE THE EASTWARD MOVING CONVECTION REACHES IT. COVERAGE WILL
INCREASE THROUGH THE AFTERNOON DUE TO VARIOUS BOUNDARY COLLISIONS.
AS IN PREVIOUS LATE AFTERNOONS AND EVENINGS STORMS TO END AROUND
SUNSET...LOSS OF DAYTIME HEATING AND BOUNDARY COLLISIONS SLOWING
DOWN AND ENDING LATE EVENING. LOW AND MID LEVEL DEBRIS CLOUDS
DISSIPATE AND SKIES TO BECOME PARTLY CLOUDY TO MOSTLY CLEAR LATE
NIGHT.
FRIDAY-SATURDAY...HIGHER RAIN CHANCES WILL CONTINUE INTO THE START
OF THE UPCOMING WEEKEND WITH WSW LOW LVL FLOW AND DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES AROUND TWO INCHES OR GREATER INTO SATURDAY
ACROSS EAST CENTRAL FL AHEAD OF A STALLED FRONTAL BOUNDARY ACROSS S
GA AND FL PANHANDLE. MID LVL IMPULSES ARE PROGGED TO MOVE ACROSS THE
NRN FLORIDA PENINSULA FRIDAY INTO SATURDAY WHICH WILL PROVIDE
ADDITIONAL ORGANIZATION FOR STORM DEVELOPMENT BY LATE MORNING INTO
THE AFTERNOON EACH DAY. SHOULD SEE A LATE AFTERNOON SEA BREEZE NEAR
THE COAST EACH AFTERNOON BUT IT IS NOT EXPECTED TO PUSH VERY FAR
INLAND. SHOWER AND THUNDERSTORM CHANCES WILL BE AROUND 50 PCT WITH
HIGH TEMPERATURES AROUND 90/LWR 90S NEAR THE COAST TO LWR-MID 90S
OVER THE INTERIOR. LOWS WILL BE IN THE 70S.
SUNDAY...THE LOW LVL RIDGE AXIS WILL BEGIN TO LIFT NORTHWARD TWD
LAKE OKEECHOBEE WITH LIGHTER LOW LVL WINDS ACROSS SRN SECTIONS AND
LIGHT SW FLOW ACROSS THE NORTH. OVERALL MOISTURE LEVELS WILL BE ON
THE DECREASE WITH THE MID LVL RIDGE STARTING TO BUILD OVER SRN
SECTIONS. THIS SHOULD LOWER RAINFALL CHANCES INTO THE LOWER CHANCE
CATEGORY FROM 30-40 PCT WITH THE HIGHER CHANCES ACROSS INTERIOR
SECTIONS IN THE AFTERNOON. ANOTHER HOT AFTERNOON WITH HIGHS IN THE
LOWER 90S COAST TO MID 90S INTERIOR.
MON-WED...THE GFS HAS BACKED OFF ON DEEPER MOISTURE MAKING IT TO THE
AREA WITH PRONOUNCED DRYING PROGGED NEAR THE LOW-MID LYR RIDGE AXIS
WHICH WILL BE LIFTING TWD E CENTRAL FL EARLY NEXT WEEK. THE 00Z
ECMWF IS ALSO SHOWING THE DRYING TREND WITH DECREASING MOISTURE IN
THE H8-H5 LAYER BY MON-TUE. HAVE LOWERED RAIN CHANCES TO THE 20-30
PCT RANGE MON-WED OF NEXT WEEK WITH HIGHER CHANCES ACROSS INTERIOR
SECTIONS LATE IN THE DAY WITH SEA BREEZE INTERACTIONS. IT WILL
CONTINUE HOT WITH HIGHS IN THE LOWER 90S ALONG THE COAST AND MID 90S
OVER THE INTERIOR. LOWS WILL BE IN THE 70S.
&&
.AVIATION...
PREVAILING VFR THROUGH 15Z. ISOLD TSRA DEVELOPING ACROSS REGION
AFTER 16Z...WITH SCT TSRA MOVING FROM WEST TO EAST ACROSS STATE WITH
WEST COAST SEA BREEZE THROUGH AFTERNOON. EAST COAST SEA BREEZE
DEVELOPING AFTER 17Z...REACHING KFPR/KSUA/KCOF...BUT LIKELY
REMAINING JUST EAST OF KVRB/KMLB/KTIX. BEST COVERAGE OF TSRA ALONG
COAST...WITH A FEW PRODUCING G35KTS ESPECIALLY WHERE THEY COLLIDE
WITH EAST COAST SEA BREEZE FROM KXMR SOUTHWARDS ALONG IMMEDIATE
COAST.
&&
.MARINE...
TODAY-TONIGHT...HIGH PRESSURE REMAINS TO THE SOUTH THEREFORE
MODERATE SOUTHWEST TO WEST WILL CONTINUE OVERNIGHT. BOATERS ON THE
INTRACOASTAL AND NEARSHORE WATERS SHOULD KEEP AN EYE TO THE WEST FOR
APPROACHING STORMS AND SEEK SAFE HARBOR TO RIDE OUT THE STORMS.
SW-S WINDS TO 10 TO 15 KNOTS FRI-SAT WITH OFFSHORE MOVING SHOWERS
AND LIGHTNING STORMS. THE SFC RIDGE WILL BUILD NWD TWD THE SRN
WATERS EARLY NEXT WEEK WITH S WINDS ACROSS THE SRN WATERS AND SW
WINDS NORTH OF THE CAPE. SEAS 1-2 FT NEAR SHORE TO 2-3 FT OFFSHORE.
SHOULD SEE A LOWER COVERAGE OF SHOWER/STORMS AFFECTING THE ATLC
SUNDAY INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 76 90 76 / 50 30 50 30
MCO 95 76 92 75 / 50 30 50 30
MLB 92 75 90 76 / 50 30 50 30
VRB 92 75 91 75 / 50 30 50 30
LEE 94 77 93 77 / 50 30 50 20
SFB 95 77 93 77 / 50 30 50 30
ORL 94 77 94 78 / 50 30 50 30
FPR 91 74 91 75 / 50 30 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...MOSES
LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS DES MOINES IA
341 AM CDT THU AUG 14 2014
.SHORT TERM /TODAY/...
ISSUED AT 340 AM CDT THU AUG 14 2014
RIDGE OF HIGH PRESSURE OVER THE NORTHERN GREAT LAKES AND SOUTHERN
CANADA WILL HOLD FOR ANOTHER DAY TODAY AS IT SLOWLY DRIFTS EAST.
PATCHY FOG...A FEW AREAS OF DENSE FOG THIS MORNING SHOULD LIFT
QUICKLY BY 13Z SHORTLY AFT SUNRISE. LOW PRESSURE OVER THE CENTRAL
ROCKIES WILL MOVE LITTLE THROUGH THIS AFTERNOON. HOWEVER...A WARM
FRONT STRETCHING EAST SOUTHEAST FROM THE LOW OVER SOUTHERN KANSAS
WILL BEGIN TO LIFT NORTH DURING THE AFTERNOON INTO NORTHERN
KANSAS. WARM AIR ADVECTION ALOFT AND A WEAK WAVE WILL CONTINUE AN
AREA OF SHOWERS AND THUNDERSTORMS OVER SOUTH DAKOTA WHICH SHOULD
GENERALLY REMAIN NORTHWEST OF THE REGION THROUGH LATE TODAY.
CIRRUS CONTINUE TO SPILL OVER THE H700 RIDGE TONIGHT...AND EXPECT
SOME HIGH CLOUDS TO CROSS THE REGION THIS AFTERNOON AND TONIGHT.
BY LATE AFTERNOON THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND ISO
THUNDER FAR NORTHWEST AS THE NORTHERN STREAM SHORTWAVE APPROACHES
THE AREA. BOTH SYNOPTIC SCALE MODELS AND THE HRRR INCREASE FORCING
ACROSS THE FAR NORTHWEST THIS AFTERNOON. HIGHS TODAY WITH THE
POTENTIAL FOR MORE CLOUDS NORTHWEST AND INCREASING HIGH CLOUDS
ELSEWHERE...SHOULD HOLD HIGHS IN THE UPPER 70S TO LOWER 80S REGION
WIDE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 340 AM CDT THU AUG 14 2014
THE FIRST WAVE ARRIVES TONIGHT WITH MOISTURE INCREASING ALOFT INTO
AN UPPER LEVEL BOUNDARY ACROSS THE REGION. MODELS CONTINUE TO SHOW
INCREASING THETAE ADVECTION FROM 00Z TO 12Z FRIDAY OVER THE FORECAST
AREA. FLOW AT H850 REMAINS WEAK WITH SLOWLY EXITING HIGH PRESSURE TO
THE EAST. THIS WILL ALLOW ANY CONVECTION TO GRADUALLY WEAKEN
OVERNIGHT AS IT PUSHES ACROSS THE NORTHEAST WITH SHOWERS AND PERHAPS
ISOLATED THUNDER THROUGH FRIDAY MORNING. BY FRIDAY AFTERNOON...
DAYTIME HEATING...INCREASED MOISTURE TRANSPORT AND STRENGTHENING
H850 WINDS SHOULD INCREASE THE SHOWERS AND THUNDERSTORM ACTIVITY
OVER THE AREA ACROSS THE NORTHEAST AND SOUTHWEST. RAINFALL AMOUNTS
WILL REMAIN LIGHT THROUGH FRIDAY AFTERNOON. BY 00Z SATURDAY THE
MODELS ARE IN GENERALLY GOOD AGREEMENT HAVING THE WARM FRONT NEAR
THE IA MO BORDER AS AN H850 LOW APPROACHES WITH ANOTHER PUSH OF
STRONGER THETAE ADVECTION...H850 WINDS TO 25KT INCREASING TO 40KTS
BY 06Z OVER THE SOUTH. WITH THE STRONG FORCING AND BOUNDARY ALOFT...
THERE IS AN INCREASING CHANCE FOR AN MCS TO FORM OVER NORTHWEST MO
AND LIFT EAST NORTHEAST INTO SOUTHERN IOWA THROUGH THE NIGHT. BUFKIT
SOUNDINGS OVER SOUTHERN IOWA INDICATE SATURATION FROM H800 TO H300.
PRECIPITABLE WATER VALUES INCREASE TO 2 TO 2.25 INCHES BY 06-12Z
SATURDAY OVER SOUTHERN IOWA. AS WELL...WARM CLOUD DEPTHS TO 14 TO
15KFT DURING THIS TIME. THIS SHOULD PROMOTE VERY EFFICIENT RAINFALL
ACROSS THE BOUNDARY WITH ELEVATED CONVECTION. WITH INSTABILITY
VALUES DECREASING OVERNIGHT... THE MAIN CONCERN WILL BE HEAVY
RAINFALL. WITH THE FORECAST PARAMETERS...THERE IS A POTENTIAL FOR 2
TO +3 INCH TOTALS WITH ANY MCS THAT DEVELOPS. WILL CONTINUE TO
REFINE DETAILS OVER THE NEXT SEVERAL PACKAGES. AS THE CONVECTION
PULLS EAST SATURDAY MORNING THE UPPER LEVEL LOW WILL SLOWLY DRIFT
EAST. THIS WILL KEEP SHOWERS AND SCT THUNDER IN THE FORECAST FOR
SATURDAY. HIGHS FRIDAY WILL BE IN THE 70S TO LOWER 80S WITH THE
COOLER READINGS OVER THE NORTH. SATURDAY WILL SEE A MORE UNIFORM DAY
WITH MOST AREAS NEAR 80 FOR THE AFTERNOON AS CLOUD COVER AND THE
CHANCE FOR RAIN HOLDS. DEW POINTS WILL BE CLIMBING OVER THE NEXT
SEVERAL DAYS...WITH MORE UNCOMFORTABLE CONDITIONS EXPECTED. THE
SHOWER AND THUNDERSTORM POTENTIAL WILL LAST INTO SUNDAY AS THE UPPER
LEVEL SYSTEM PULLS EAST OF THE REGION. ON MONDAY THE AREA SHOULD BE
IN BETWEEN SYSTEMS WITH LITTLE CHANCE FOR ANY RAIN CENTRAL...SLIGHT
CHANCES EAST AND WEST. THE NEXT NORTHERN STREAM WAVE RETURNS FOR
MONDAY NIGHT AND TUESDAY WITH ANOTHER WARM FRONT ADVANCING EAST
ACROSS THE REGION. THIS SHOULD BRING AN ADDITIONAL CHANCE FOR SOME
THUNDERSTORMS MONDAY NIGHT AND TUESDAY WITH WARMER TEMPERATURES FOR
WEDNESDAY. IN FACT...H850 TEMPS ARE EXPECTED TO INCREASE TO 20C BY
WEDNESDAY WITH HIGHS IN THE MID 80S AND DEW POINTS BACK NEAR 70.
&&
.AVIATION...14/06Z
ISSUED AT 1153 PM CDT WED AUG 13 2014
LITTLE CHANGE TO PREVIOUS THOUGHTS AS WIDESPREAD VFR CONDITIONS
WILL PERSIST FOR MUCH OF THE FORECAST PERIOD. SOME GROUND FOG WILL
BE POSSIBLE THROUGH DAYBREAK ON THURSDAY...BUT SHOULD REMAIN
RELATIVELY ISOLATED. ANY CEILINGS THAT DEVELOP THURSDAY INTO
THURSDAY EVENING WILL REMAIN VFR AND LIKELY AT OR ABOVE 12KFT.
LIGHT AND VARIABLE OVERNIGHT WINDS WILL BECOME LIGHT FROM THE
SOUTHEAST ON THURSDAY AS SURFACE RIDGE SLIDES EAST OF THE STATE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...REV
AVIATION...COGIL
AREA FORECAST DISCUSSION
NWS PADUCAH KY
229 AM CDT Thu Aug 14 2014
.SHORT TERM...(Today through Saturday)
Issued at 229 AM CDT THU AUG 14 2014
High pressure was centered over the region during the overnight
hours, with a frontal boundary draped across parts of IA, IL, IN and
into OH. Models have been advertising this back door cold front for
several days now. It will continue to sag southwest toward the area
today. A band of mid clouds is seen on satellite and METAR
observations/radar indicate that some spotty showers are resulting
from these clouds. The frontal boundary should reach parts of
southern IL and southwest IN by afternoon or early evening.
Models differ on whether precipitation develops into our CWA
however. The 00Z NAM and latest RUC keep the QPF just north of us,
while the GFS indicate a very small sliver of our northernmost
counties have a chance of seeing a few showers. Some of the hi res
models (ARW/NMM) show a band of spotty showers dropping into parts
of southern IL, southwest IN and parts of KY during the late
afternoon hours. Might opt to throw in some light showers or
sprinkles up in the far north since there may be just enough low
level moisture to bring a few drops to the ground. Will wait and see
what surrounding offices want to do.
Temperatures today should be in the lower to mid 80s, similar to
what occurred yesterday. However, it might be a bit warmer in parts
of SEMO today since winds will become more southerly there.
Whatever precipitation does occur later today should be short lived
as the front disintegrates and high pressure tries to build in behind
it tonight. On Friday, moisture begins to increase which will mean
an increase in cloudiness. Meanwhile, mid/upper heights will begin
rising by late in the week and into weekend, which will mean a bump
in temperatures. Sfc winds will also eventually shift around to the
south as well. We should see upper 80s area wide on Friday and
Saturday.
Next item of business is watching how a mid level short wave moves
across the top of a prominent ridge across the mid CONUS. It is
slated to drop southeast toward the area Friday night into Saturday.
We believe Friday night should be mainly dry but chances for rain
will have to be maintained at least in our northwestern sections for
Saturday. However, the better chances look to arrive Saturday night.
.LONG TERM...(Sunday through Wednesday)
Issued at 229 AM CDT THU AUG 14 2014
A blend of the 00z/12z GFS/GEFS and 12z ECENS was used for this
forecast. This resulted in little change to the inherited PoPs and
resultant temperatures. Temperatures will be geared toward MOS and
CONUS raw model output.
Slow moving upper trof is forecast to approach the CWFA Saturday
night and slowly progress ESE across the region through Sunday
night. Will carry good chance PoPs for convection as a result given
the respectable moisture coupled with mid trop forcing that will
accompany the upper system.
The system will head on to the east Monday. Will linger chance PoPs
over the east, and taper them off west. We may see a lull Monday
night as weak s/wv ridging moves overhead. Inherited 20% values and
see no reason to drop them yet, until a more clear signal is
established.
As some deamplification of the pattern occurs, the WNW flow pattern
across the area will weaken. We will be in broad SSW surface slow as
broad low pressure develops over the plains. Little to key in on
feature wise. The models continue to develop QPF over the region in
what should be a weak but unsettled mid trop flow pattern. Therefore
will carry low chance PoPs during the day Tue/Wed, and taper them
off to slight chances at night.
&&
.AVIATION...
Issued at 229 AM CDT WED AUG 13 2014
Persistence strategy suggests vsbys should hold tonight with
minimal fog risk, though it`s something to watch as skies
clear/winds go calm...wouldn`t be a shocker. Otherwise light nlys
and maybe scattered cu bases around 5K again tmrw pm.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
315 AM EDT THU AUG 14 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EDT THU AUG 14 2014
06Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE THROUGH THE TENNESSEE
VALLEY WITH A MOSTLY DRY COLD FRONT TO OUR NORTH DROPPING SOUTH
THROUGH THE OHIO VALLEY. THIS HAS LEFT MOST OF EAST KENTUCKY UNDER
CLEAR SKIES WITH A DRY AIR MASS IN PLACE. COMBINED WITH LIGHT
WINDS...THE RADIATIVE COOLING IS HELPING TO DROP TEMPERATURES INTO
THE 50S THROUGH THE AREA. IN THE VALLEYS THESE TEMPS ARE GETTING
CLOSE TO THE DEWPOINTS RESULTING IN THE FORMATION OF FOG ALONG WITH
THE POTENTIAL FOR LOCALLY DENSE PATCHES. HAVE ALLOWED FOR THIS IN THE
GRIDS THROUGH 13Z. ASSOCIATED WITH THE DESCENDING FRONT TO THE
NORTH...A PATCH OF MID LEVEL CLOUDS ARE SETTING INTO NORTHERN
KENTUCKY AND THIS SHOULD LIMIT THE COOLING AND FOG FORMATION IN THOSE
PARTS THROUGH DAWN. THE AREAS OF DENSE FOG WILL BE HIGHLIGHTED IN THE
HWO FOR EARLY THIS MORNING.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT THE RESURGENCE OF THE
UNSEASONABLY DEEP ONTARIO UPPER LOW THROUGH THE DAY WITH ITS
SOUTHWARD PUSH OF ENERGY AND HEIGHT FALLS. THE BEST ENERGY WITH THIS
WILL STAY JUST NORTHEAST OF JKL THROUGH FRIDAY MORNING BEFORE THE LOW
GYRATES BACK FURTHER NORTH DURING THE DAY FRIDAY ALLOWING FOR RISING
HEIGHTS AND A DEPARTING ENERGY STREAM. WITH A SLIGHTLY SLOWER
MOVEMENT TO THE UPPER LOW...THE NAM KEEPS THE LOWER HEIGHTS IN THE
SOUTHERN OHIO VALLEY A BIT LONGER INTO THE DAY FRIDAY. HAVE FAVORED A
GENERAL MODEL BLEND GIVEN THE SIMILARITIES...THOUGH THE HIGHER
RESOLUTION HRRR AND NAM12 WERE GIVEN MORE EMPHASIS FOR THE FIRST
PART OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANTLY COOL AND MOSTLY DRY
DAY UNDER PARTLY CLOUDY TO MOSTLY SUNNY SKIES. THE COLD FRONT WILL
SETTLE INTO NORTHERN PARTS OF THE CWA AND MAKE FOR A THREAT OF
SPRINKLES OR A STRAY SHOWER TODAY. THE MODEL FORECAST SOUNDINGS ARE
UNFAVORABLE FOR THUNDER WITH A MID LEVEL CAP AND LOW CAPE VALUES SO
HAVE KEPT OUT THUNDER FOR THE GRIDS. CANNOT RULE OUT A STRAY SHOWER
INTO THE NIGHT TONIGHT...BUT GIVEN THE LOSS OF DIURNAL HEATING WILL
KEEP IT DRY. AGAIN PATCHY FOG...LOCALLY DENSE...CAN BE ANTICIPATED IN
THE VALLEYS FOR FRIDAY MORNING...BUT PROBABLY NOT AS EXTENSIVE AS
THIS MORNING/S WILL LIKELY END UP. THE FRONT REMAINS AROUND INTO THE
DAY FRIDAY...BUT RISING HEIGHTS WILL KEEP THE RISK OF SPRINKLES OR
SHOWERS TO A MINIMUM...WHILE ANOTHER RELATIVELY COOL SUMMER DAY IS
HAD BY ALL.
USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE
SOME ADJUSTMENTS TONIGHT FOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
AND TONIGHT FOR THE NORTHERN PARTS OF THE AREA...OWING TO THE
FRONT...WAS IN LINE WITH THE GUIDANCE ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 AM EDT THU AUG 14 2014
THE MODELS WERE STILL IN DECENT AGREEMENT IN THE EXTENDED. THE
OVERALL MID AND UPPER LEVEL PATTERNS ARE PROGGED TO FEATURE A RIDGE
OF HIGH PRESSURE WEAKENING AND RETREATING SOUTHEASTWARD OUT OF THE
OHIO AND TENNESSEE VALLEY REGIONS FRIDAY NIGHT AND SATURDAY. THIS
WILL ALLOW THE PERIOD TO START OUT DRY WITH INCREASING CLOUD COVER
AND LIGHT WINDS ON TAP FOR EASTERN KENTUCKY. THE CLOUD COVER WILL BE
IN RESPONSE TO AN AREA OF LOW PRESSURE AND ITS ASSOCIATED FRONTAL
BOUNDARY TAKING SHAPE OVER THE EAST CENTRAL PLAINS AND MOVING
EASTWARD TOWARD THE AREA SUNDAY AND SUNDAY NIGHT. THE INITIAL AREA
OF LOW PRESSURE LOOKS TO MOVE ACROSS THE AREA SUNDAY NIGHT. A
FRONTAL BOUNDARY EXTENDING FROM THIS LOW WILL STALL OUT ALONG THE
TENNESSEE VALLEY REGION EASTWARD TO THE EAST COAST OF THE CONUS. THE
PRESENCE OF THIS BOUNDARY WOULD KEEP A CHANCE OF SHOWERS AND STORMS
IN THE FORECAST FROM EARLY SUNDAY THROUGH THE END OF THE UPCOMING
WORK WEEK. WAVES OF LOW PRESSURE MOVING ALONG THE FRONT WOULD
PROVIDE THE LIFT NEEDED TO SPAWN SHOWERS AND STORMS AS MOISTURE FORM
THE GULF OF MEXICO RIDES UP AND OVER THE FRONT. THE ISSUE AT HAND
WILL BE THE TIMING OF THESE WAVES OF LOW PRESSURE AND HOW MUCH
MOISTURE THEY WILL HAVE TO TAP INTO. BASED ON THIS BIT OF
UNCERTAINTY...DECIDED TO KEEP PRECIPITATION CHANCES BETWEEN 20 AND
40 PERCENT ACROSS THE BOARD...FAVORING THE DAYTIME HOURS FOR PEAK
ACTIVITY WITH LULLS IN THE ACTION DURING THE NIGHTTIME PERIODS.
TEMPERATURES THROUGHOUT THE PERIOD SHOULD BE ABLE TO RECOVER TO
NORMAL VALUES FOR THIS TIME OF YEAR AS THE GULF OF MEXICO OPENS UP
AND WARM MOIST AIR INVADES THE REGION FROM THE SOUTH. HIGHS IN
GENERAL ARE EXPECTED TO BE IN THE MID 80S THROUGHOUT THE PERIOD WITH
OVERNIGHT LOWS IN THE UPPER 60S THE FIRST SEVERAL NIGHTS...TO AROUND
70 BY THE END OF THE WEEK. THE ONE EXCEPTION MIGHT BE FRIDAY NIGHT
BEFORE THE WINDS SHIFT TO THE SOUTH AND THE WARMER AIR FROM THE GULF
MAKES IT WAY INTO THE AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 155 AM EDT THU AUG 14 2014
MOSTLY CLEAR SKIES AND NEARLY CALM WINDS WILL LIKELY ALLOW FOR SOME
DENSE FOG TO DEVELOP ACROSS EASTERN KENTUCKY LATER TONIGHT...
PARTICULARLY IN THE VALLEYS. FOG ALREADY EXISTS IN THESE SPOTS AND
WILL EXPAND INTO MOST OF THE VALLEYS AND EVEN UP SOME RIDGES DURING
THE 08 TO 12Z TIME FRAME. HAVE GONE LIFR AT MOST LOCATIONS...AND
INCLUDED SOME IFR AT JKL ...OR THIS. THE FOG WILL BURN OFF BETWEEN
12 AND 13Z THURSDAY...GIVING WAY QUICKLY TO VFR CONDITIONS AND LIGHT
NORTHWEST WINDS THAT WILL LAST THROUGH THURSDAY EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
449 AM EDT THU AUG 14 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM EDT THU AUG 14 2014
FOR THE TIME BEING...MODELS ARE IN GOOD AGREEMENT THROUGH MUCH OF
THE FORECAST PERIOD. THE CWA WILL BE UNDER NW FLOW ALOFT FRI INTO
SUN BEFORE AN UPPER RIDGE PASSES OVERHEAD LATE SUN INTO MON...THEN
AN UPPER TROUGH MOVES INTO THE AREA THE REGION TUE INTO WED. HAVE
GOOD CONFIDENCE THROUGH THE WEEKEND...BUT MODELS HAVE SHOWN POOR RUN
TO RUN CONTINUITY NEXT WEEK.
MODELS HAVE TRENDED DRIER ON FRI FOR THE CWA AS THEY DEPICT BEST
FORCING BEING W OF THE CWA AS A SHORTWAVE MOVES THROUGH THE NW FLOW.
WILL CONTINUE TO SHOW SLIGHT CHANCE POPS GIVEN MARGINAL INSTABILITY
/MLCAPE VALUES LESS THAN 500 J/KG/ AND UNCERTAINTY IN THE TRACK OF ANY
SHORTWAVES.
A STRONGER SHORTWAVE AND ASSOCIATED SFC COLD FRONT WILL MOVES
ACROSS THE CWA FRI INTO INTO SAT...BRINGING GREATER CHANCES FOR
PRECIP. WILL FAVOR THE NERN HALF OF THE CWA WITH THE GREATEST POPS
AS MODELS INDICATE BEST FORCING WILL EXIST THERE.
A SFC HIGH MOVES INTO THE REGION ALONG AND AHEAD OF THE UPPER
RIDGE...WHICH SHOULD LEAD TO DRY CONDITIONS SUN THROUGH MON...BEFORE
PRECIP CHANCES INCREASE MON NIGHT INTO WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 737 PM EDT WED AUG 13 2014
A DRY AIR MASS ASSOCIATED WITH HIGH PRES BUILDING OVER THE UPPER
GREAT LAKES WILL RESULT IN VFR CONDITIONS PREVAILING AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EDT THU AUG 14 2014
W-NW GUSTS OF 20-25KTS WILL REMAIN POSSIBLE OVER MAINLY THE E HALF
OF LAKE SUPERIOR THROUGH THE EARLY EVENING HOURS. HIGH PRESSURE OVER
W LAKE SUPERIOR WILL WEAKEN SLIGHTLY ACROSS ALL OF LAKE SUPERIOR ON
THURSDAY...BEFORE DIVING TO THE OH RIVER VALLEY THURSDAY NIGHT INTO
FRIDAY. A TROUGH EXTENDING FROM THE DAKOTAS THROUGH HUDSON BAY WILL
SINK ACROSS LAKE SUPERIOR SATURDAY MORNING...AND ACROSS LOWER MI AND
LAKE HURON SATURDAY EVENING. THIS WILL ALLOW A LARGE HIGH OVER N
ONTARIO SATURDAY NIGHT TO PUSH ACROSS LAKE SUPERIOR SUNDAY AFTERNOON
THROUGH MONDAY...AS A TROUGH OF LOW PRESSURE DEVELOPS OVER MANITOBA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
317 AM EDT THU AUG 14 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 331 PM EDT WED AUG 13 2014
12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE UPR LKS BETWEEN SHARP UPR TROF CENTERED NEAR JAMES BAY AND AN
UPR RDG OVER THE WRN PLAINS. THERE IS A SHRTWV EMBEDDED IN THIS FLOW
THAT IS DIVING THRU ERN LK SUP...BUT THE MID LVLS ARE SUFFICIENTLY
DRY/STABLE OVER THE UPR LKS PER THE 12Z INL/YPL RAOBS THAT THERE
HAVE BEEN NO SHOWERS. BUT THESE RAOBS ALL SHOW A GOOD DEAL OF LLVL
MSTR. WITH THE ONSET OF DAYTIME HEATING...A GOOD DEAL OF LO CLD
DVLPD...ESPECIALLY OVER THE W AND NCENTRAL WHERE THE SFC-H925 NLY
FLOW UPSLOPES OFF LK SUP. THE STEADY/GUSTY N WIND IS CAUSING HIER
WAVES/DANGEROUS SWIMMING CONDITIONS IN THE LK SUP BEACHES E OF THE
KEWEENAW. CLOSER TO HI PRES OVER FAR NW ONTARIO WHERE THE LLVL
AIRMASS IS MUCH DRIER AS SHOWN ON THE 12Z CHURCHILL MANITOBA
RAOB...THERE ARE FEWER CLDS AND WINDS ARE LGT.
MAIN FCST CONCERNS IN THE SHORT TERM ARE CLD TRENDS THIS AFTN AND
THEN TEMPS TNGT AND THU AS THE DRY HI PRES IN ONTARIO WL DOMINATE.
LATE THIS AFTN/TNGT...UNDER CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR
DVGC...SFC HI PRES OVER FAR NW ONTARIO IS PROGGED TO SINK OVER WRN
LK SUP BY 12Z THU. WITH LOSS OF DAYTIME HEATING AND LLVL DRY ADVCTN
IN THE LLVL NLY FLOW AHEAD OF THE SFC HI PRES...EXPECT ANY LINGERING
CLDS TO DISSIPATE THIS EVNG AND GIVE TO MOCLR SKIES OVERNGT. THE
ARRIVAL OF DRIER AIR FM THE N...WITH PWAT SINKING AS LO AS 0.33 INCH
OR 30-35 PCT OF NORMAL...FAVORS A LARGE DIURNAL DROP OF TEMP...
ESPECIALLY OVER THE W WHERE THE WINDS WL BE LIGHTER CLOSER TO THE
INCOMING SFC RDG AXIS. WL MAINTAIN FCST LO TEMPS IN THE 30S AT THE
COLDER INTERIOR LOCATIONS IN THIS AREA. STEADY N WIND OVER THE E
UNDER THE SHARPER PRES GRADIENT BTWN THE RDG AND LO PRES OVER QUEBEC
WL TEND TO RESTRICT THE DIURNAL TEMP DROP THERE.
THU...SFC HI PRES AXIS IS FCST TO SHIFT FM NCENTRAL UPR MI THRU LK
MI. WITH CORE OF DRY AIR OVHD...EXPECT NOTHING MORE THAN SOME
DIURNAL CU OVER THE INTERIOR. H85 TEMPS ARE FCST TO PEAK BTWN ABOUT
8C OVER THE E TO 12C OVER THE W. MIXING TO H8 ON FCST SDNGS
INDICATES MAX TEMPS WL PEAK NEAR 75 OVER THE INTERIOR W AND
SCENTRAL. WITH A STEADY NW WIND OFF LK SUP OVER THE E THAT WL
MAINTAIN HIER WAVES/SWIM RISK...TEMPS WL HAVE A HARD TIME RISING
OVER 70 EXCEPT CLOSER TO LK MI. AFTN MIXING WL CAUSE MIN RH TO
BOTTOM OUT AS LO AS 30-35 PCT OVER MUCH OF THE INTERIOR. DESPITE THE
SOMEWHAT COOLER TEMPS OVER THE E...STRONGER WINDS WL AGGRAVATE FIRE
WX CONDITIONS THERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 317 AM EDT THU AUG 14 2014
FOR THE TIME BEING...MODELS ARE IN GOOD AGREEMENT THROUGH MUCH OF
THE FORECAST PERIOD. THE CWA WILL BE UNDER NW FLOW ALOFT FRI INTO
SUN BEFORE AN UPPER RIDGE PASSES OVERHEAD LATE SUN INTO MON...THEN
AN UPPER TROUGH MOVES INTO THE AREA THE REGION TUE INTO WED. HAVE
GOOD CONFIDENCE THROUGH THE WEEKEND...BUT MODELS HAVE SHOWN POOR RUN
TO RUN CONTINUITY NEXT WEEK.
MODELS HAVE TRENDED DRIER ON FRI FOR THE CWA AS THEY DEPICT BEST
FORCING BEING W OF THE CWA AS A SHORTWAVE MOVES THROUGH THE NW FLOW.
WILL CONTINUE TO SHOW SLIGHT CHANCE POPS GIVEN MARGINAL INSTABILITY
/MLCAPE VALUES LESS THAN 500 J/KG/ AND UNCERTAINTY IN THE TRACK OF ANY
SHORTWAVES.
A STRONGER SHORTWAVE AND ASSOCIATED SFC COLD FRONT WILL MOVES
ACROSS THE CWA FRI INTO INTO SAT...BRINGING GREATER CHANCES FOR
PRECIP. WILL FAVOR THE NERN HALF OF THE CWA WITH THE GREATEST POPS
AS MODELS INDICATE BEST FORCING WILL EXIST THERE.
A SFC HIGH MOVES INTO THE REGION ALONG AND AHEAD OF THE UPPER
RIDGE...WHICH SHOULD LEAD TO DRY CONDITIONS SUN THROUGH MON...BEFORE
PRECIP CHANCES INCREASE MON NIGHT INTO WED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 737 PM EDT WED AUG 13 2014
A DRY AIR MASS ASSOCIATED WITH HIGH PRES BUILDING OVER THE UPPER
GREAT LAKES WILL RESULT IN VFR CONDITIONS PREVAILING AT
KIWD/KCMX/KSAW THRU THIS FCST PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 331 PM EDT WED AUG 13 2014
UNDER A SHARP PRES GRADIENT BETWEEN HI PRES SINKING SOUTH THRU FAR
WESTERN ONTARIO AND SLOW MOVING LO PRES IN WESTERN QUEBEC...EXPECT N
TO NW WINDS AS HI AS 20-25 KTS OVER THE E HALF OF LAKE SUPERIOR THRU
THU. AS THE ONTARIO HI MOVES OVER THE UPPER LAKES LATER ON THU...
EXPECT WINDS TO DIMINISH UNDER 15 KTS BY FRI. THESE LIGHTER WINDS
WILL PERSIST INTO SAT...BUT THE SHARPENING PRES GRADIENT BEHIND A
COLD FRONTAL PASSAGE WILL CAUSE N-NE WINDS TO INCREASE UP TO 20 KTS
ON SAT NIGHT INTO SUN. AS THE HI PRES TRAILING THE FRONT SLIDES TO
THE SE EARLY NEXT WEEK...WINDS WILL SHIFT TO THE SSE UP TO 20 KTS ON
MON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...KC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
305 AM MDT THU AUG 14 2014
.SHORT TERM...VALID FOR TDY AND FRI...
A WET DAY IS AHEAD FOR MUCH OF SOUTHEASTERN MONTANA AND NORTHERN
WYOMING...
MODELS IN GOOD AGREEMENT IN BRINGING SHORT WAVE ENERGY INTO
NORTHERN WY AND SOUTH CENTRAL MT BY THURSDAY AFTERNOON. MONSOONAL
MOISTURE FETCH DEPICTED ON WATER VAPOR CONTINUES TO RIDE THE
WESTERN SIDE OF THE UPPER LEVEL RIDGE INTO THE NORTHERN ROCKIES.
NAEFS PW ANOMALIES ARE SHOWING STANDARD DEVIATION VALUES GREATER
THAN 2 FOR MUCH OF THE BYZ CWA. IN ADDITION...LATEST HRRR GUIDANCE
DEPICTING WIDESPREAD SHOWER ACTIVITY IN A LINE FROM WHEATLAND
COUNTY DOWN TO SOUTHERN ROSEBUD COUNTY BY MID MORNING.
FURTHER...WPC 6 HOUR PQPF GUIDANCE SHOWS NICE AREA OF >80 PERCENT
PROBABILITY OF MEASURABLE PRECIPITATION OVER MUCH OF THE CWA BY
00 UTC FRIDAY. SO...WITH ALL OF THAT...DECIDED TO CONTINUE WITH
TREND OF RAISING POPS ON TOP OF WHAT PREVIOUS FORECAST ALREADY HAD
ACROSS THE ENTIRE CWA. NOT EXPECTING PRECIPITATION TODAY TO BE
SEVERE IN NATURE...BUT A FEW OF THESE ISOLATED STORMS COULD
PRODUCE HEAVY RAIN AT TIMES. STORMS THAT HAVE DEVELOPED THE PAST
DAY OR SO HAVE SHOWN NICE KDP RETURNS ON RADAR. THIS BEARS
WATCHING AS STORMS THAT FORM OVER BURN SCAR AREAS MAY BE
SUSCEPTIBLE TO DEBRIS FLOWS AND SUCH.
TEMPERATURES SHOULD BE COOLER TODAY...WITH CLOUD COVER AND
PRECIPITATION IN THE AREA...WITH HIGHS IN THE UPPER 80S TO LOW 90S
ACROSS THE PLAINS.
FOR FRIDAY...THE LOW THAT HAS BEEN STALLED OVER THE PAC NW FOR
THE LAST DAY OR SO WILL BEGIN TO MOVE EASTWARD. EVEN THOUGH BEST
FORCING WILL BE TO THE WEST OF THE BYZ CWA...THERE WILL BE ENOUGH
LEFT OVER MONSOONAL MOISTURE TO GENERATE SOME SHOWERS ACROSS THE
REGION. SINGER
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MODELS WERE IN PRETTY GOOD AGREEMENT THROUGH THE EXTENDED
PACKAGE. THE NORTHWEST UPPER LOW CURRENTLY OVER NORTH CENTRAL
OREGON IS PROGGED TO SLIDE ACROSS NORTHERN MONTANA THIS WEEKEND.
DEEPEST INSTABILITY WILL BE OVER SOUTHEAST MONTANA ON SATURDAY AS
THESE LOCATIONS WILL BE EAST OF A SURFACE TROUGH. THE SURFACE
TROUGH WILL SLIDE EAST ON SUNDAY FOR A LESSENING CHANCE OF
CONVECTION. THE FLOW DRIES OUT SOME FOR MONDAY AND TUESDAY AS IT
BACKS TO THE NORTHWEST. HEIGHTS WILL FALL FOR WEDNESDAY AND
THURSDAY AS AN UPPER TROUGH DROPS SOUTHEAST FROM SOUTHWEST CANADA.
THIS WILL INCREASE THE CHANCE OF SHOWERS AND THUNDERSTORMS. TWH
&&
.AVIATION...
SHOWERS WILL SPREAD NORTH FROM WYOMING THIS MORNING AND ENTER
KSHR/KBIL/KLVM BY 16Z. THE SHOWERS WILL SPREAD NORTHWARD TOWARD
KMLS AND KBHK BY 20Z. THE HEAVIER SHOWERS WILL PRODUCE LOCAL MVFR
CONDITIONS WITH BRIEF HEAVY RAIN POSSIBLE. THE BEST CHANCE FOR
THUNDERSTORM DEVELOPMENT WILL BE OVER SOUTHEAST MONTANA THIS
AFTERNOON. THE BEST CHANCE OF SHOWERS WILL SHIFT OUT OF SOUTH
CENTRAL MONTANA AND INTO SOUTHEAST MONTANA THIS EVENING. TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 087 064/089 062/088 061/088 061/087 061/091 061/087
6/T 43/T 32/T 22/T 21/B 11/U 12/T
LVM 086 055/088 053/087 052/088 052/086 053/088 053/086
5/T 54/T 42/T 22/T 22/T 21/B 12/T
HDN 088 061/090 059/090 058/090 058/089 058/093 058/090
6/T 43/T 32/T 22/T 21/B 11/B 12/T
MLS 094 065/087 063/090 061/089 061/088 061/091 062/089
6/T 44/T 44/T 42/T 21/B 11/B 12/T
4BQ 092 065/087 062/089 060/089 059/088 059/090 060/090
6/T 64/T 43/T 33/T 31/B 11/B 12/T
BHK 093 062/085 060/087 056/086 056/085 055/087 057/087
5/T 44/T 45/T 43/T 31/B 11/B 12/T
SHR 084 058/089 056/089 054/088 054/086 054/088 055/087
6/T 43/T 32/T 22/T 21/B 11/U 12/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1102 PM MDT WED AUG 13 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 247 PM MDT WED AUG 13 2014
UPPER RIDGING ACROSS THE CENTRAL CONUS CONTINUES WITH AN UPPER LOW
OVER THE PACIFIC NW. DEEP SWRLY FLOW HAS DEVELOPED ACROSS THE DESERT
SW INTO THE GREAT BASIN AND CNTRL ROCKIES...WITH INCREASING
MONSOONAL MOISTURE OVER MUCH OF THE WRN CONUS. A SERIES OF UPPER
WAVES ARE CROSS WY/ERN MT ATTM...WITH A MUCH STRONGER WAVE OVER
AZ/UT. STORMS HAVE ALREADY FIRED AHEAD OF THE FIRST WAVE NOW
CROSSING THE WRN/CNTRL CWA. RAP MODEL IS SHOWING 3000 J/KG
MLCAPE...BUT WITH A CAP IN PLACE...CONVECTION HAS BEEN LIMITED TO
HIGHER TERRAIN OF THE BLKHLS. HRRR SHOWS MORE STORMS DEVELOPING OVER
THE NEXT HOUR OR TWO ACROSS NE WY AND PUSHING EAST THROUGH THE EVNG
HOURS. MOST OF THE STORM ACTIVITY WOULD BE EAST OF THE CWA BY 06Z
WITH LINGERING SHOWERS POSSIBLE. WEAK SHEAR WILL KEEP STORMS FROM
REACHING SEVERE...THOUGH WITH STRONG INSTABILITY CANT RULE OUT A
STORM OR TWO PRODUCING SMALL HAIL AND GUSTY WINDS LIKE THE STORM
OVER THE NORTHERN BLACK HILLS LIKELY DID EARLIER THIS AFTERNOON.
STRONG WAVE OVER THE SWRN CONUS WILL SLIDE NE TONIGHT...THEN CROSS
THE CWA LATE THURSDAY. MONSOONAL FLOW WILL RESULT IN INCREASINGLY
MOIST PROFILES THROUGH THE DAY THURSDAY WITH PWATS FORECAST TO BE
180 PERCENT OF NORMAL OR MORE. WIND PROFILES SUGGEST STORMS WILL BE
SLOW MOVING WITH MEAN STORM MOTION UNDER 10KT. STORMS WILL CONTINUE
THROUGH THURSDAY NIGHT AS THE SYSTEM SLOWLY MOVES E/NE INTO ND/CNTRL
SD. WITH THE HEAVY RAINS THAT MANY AREAS HAVE RECEIVED IN THE LAST
WEEK...THINK THERE WILL BE A POTENTIAL FOR FLASH FLOODING THURSDAY
AFTERNOON AND THROUGH THURSDAY NIGHT. HAVE ISSUED A FLASH FLOOD
WATCH FOR THIS TIME PERIOD.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 247 PM MDT WED AUG 13 2014
SEVERAL SHORTWAVES WILL AFFECT THE FORECAST AREA FROM FRIDAY INTO
EARLY NEXT WEEK...BRINGING AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS
TO PARTS OF THE FORECAST AREA NEARLY EVERY DAY. ON FRIDAY...A SLOW
MOVING SHORTWAVE HAS THE POTENTIAL TO CREATE LOCALLY HEAVY
RAINFALL GIVEN WEAK 850-300MB STEERING FLOW AND MODELED GREATER THAN
150 PERCENT PRECIPITABLE WATER AMOUNTS. TEMPERATURES THROUGH THE
PERIOD WILL BE WITHIN 5 DEGREES OF THE AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1059 PM MDT WED AUG 13 2014
AN UPPER LEVEL DISTURBANCE WILL PUSH TOWARD THE REGION WITH
INCREASING CHANCES FOR SHRA/TS THROUGH THE PERIOD. THERE IS A
SLIGHT CHANCE FOR A SHOWER OR TS TONIGHT THROUGH THUR
MORNING...WITH BETTER CHANCES FOR SHRA/TS THUR AFTERNOON/EVENING
OVER THE WESTERN 2/3. VFR CONDITIONS WILL PREVAIL OUTSIDE OF ANY
PRECIPITATION...WITH THE POTENTIAL FOR SOME MVFR STRATUS OVER
WESTERN AREAS LATE IN THE PERIOD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR SDZ001-002-012>014-024>032-041>044-072>074.
WY...FLASH FLOOD WATCH FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY
NIGHT FOR WYZ054>058-071.
&&
$$
SHORT TERM...13
LONG TERM...10
AVIATION...JC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
356 AM MDT THU AUG 14 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
LATEST WATER VAPOR IMAGERY SHOWING THE UPPER LEVEL LOW PUSHING
INTO NORTHWESTERN COLORADO THIS MORNING. LOOKS TO BE HANDLED WELL
BY THE ECMWF. LATEST MOSAIC RADAR SHOWING SHOWERS WIDESPREAD OVER
RIVERTONS CWFA WITH SOME SHOWER ACTIVITY OVER CARBON COUNTY.
MESOWEST OBSERVATIONS REPORTING MEASURABLE RAINFALL OVER THE SNOWY
AND SIERRA MADRE RANGES AS WELL AS THE NORTH LARAMIE RANGE.
FOR TODAY...WE SHOULD SEE AN INCREASE IN SHOWERS AND THUNDERSTORMS
AS THE MORNING PROGRESSES. UPPER LOW MOVES OVER CASPER BY 00Z WITH
FAIRLY WIDESPREAD SHOWERS OVER OUR SOUTHERN ZONES. PWATS FOR
RAWLINS FROM THE NAM UP NEAR 1.2 INCHES AT 18Z...NEAR 1.4 INCHES
HERE AT CHEYENNE BY 00Z AND NEAR 1.7 INCHES AT CHADRON BY 06Z THIS
EVENING. LATEST HRRR FORECAST AND FORECAST IR IMAGERY SHOWING
SHOWERS AND THUNDERSTORMS EAST OF THE LARAMIE RANGE BREAKING OUT
HERE AT CHEYENNE AROUND 15Z AND OUT IN THE PANHANDLE AFTER 18Z.
FORECAST STORM MOTIONS A LITTLE HIGHER THAN PREVIOUSLY FORECAST
WITH NAM SHOWING 10-15KTS. GIVEN THAT STORM MOTIONS ARE
HIGHER...HAVE DECIDED TO HOLD OFF ON A FLASH FLOOD WATCH. WOULD
THINK WE COULD SEE SOME FLASH FLOOD WARNING POSSIBLE THIS
AFTERNOON...BUT THESE WILL BE FOR TRAINING STORMS AND NOT FOR SLOW
MOVING STORMS. MAY TAKE ANOTHER LOOK LATER THIS MORNING WHEN THE
06Z MODEL DATA COMES OUT.
LOOKS LIKE SHOWERS AND THUNDERSTORMS WILL COME TO AN END BY 06Z
TONIGHT AS THE ECMWF SHOWS SHORTWAVE MOVING INTO CENTRAL SOUTH
DAKOTA AND CENTRAL NEBRASKA. STILL SOME POSITIVE VORTICITY
ADVECTION OVER THE NORTHERN PANHANDLE FRIDAY MORNING...SO DID KEEP
SOME SLIGHT CHANCE POPS GOING OUT THAT WAY FOR FRIDAY MORNING AND
AFTERNOON.
UPPER RIDGE BUILDS BACK INTO THE AREA FRIDAY NIGHT INTO SATURDAY AS
SHORTWAVE BEGINS TO MOVE SOUTHEAST INTO EASTERN KANSAS. 700MB
WINDS PICKING UP TO 20-25KTS ACROSS THE CWFA MAY LEAD TO
HEIGHTENED FIRE WEATHER CONCERNS SATURDAY...MORE LIKELY THOUGH ON
SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
SATURDAY NIGHT...DRY PERIOD WITH LIMITED LOW AND MID LEVEL MOISTURE
AND DOWNSLOPE WEST WINDS.
SUNDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES ACROSS EASTERN MONTANA
AND EASTERN WYOMING WITH AN ASSOCIATED SURFACE TROUGH. ISOLATED
SHOWERS AND THUNDERSTORMS EXPECTED...NORTH OF A DOUGLAS TO
SCOTTSBLUFF LINE.
MONDAY...RELATIVELY DRY NORTHWEST FLOW ALOFT PREVAILS...THOUGH LOOKS
LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR ISOLATED LATE DAY SHOWERS
AND THUNDERSTORMS FROM WHEATLAND TO ALLIANCE.
TUESDAY...SLIGHT DECREASE IN LOW AND MID LEVEL MOISTURE...ACTING AS
THE FUEL FOR THUNDERSTORMS...THUS ONLY ISOLATED STORMS AT
BEST...NORTH OF A RAWLINS TO SCOTTSBLUFF LINE.
WEDNESDAY...DRY WEST WINDS PREVAIL IN THE LOW AND MID
LEVELS...EFFECTIVELY DRYING OUT THE ATMOSPHERE EVEN MORE...AND
PRODUCING A MILD LATE AUGUST DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1129 PM MDT WED AUG 13 2014
TONIGHT...ISOLATED SHOWERS AND THUNDERSTORMS...NORTH OF A LARAMIE
TO ALLIANCE LINE...ENDING BY DAWN. VFR PREVAILS. AREAS OF LATE NIGHT
FOG AND LOW CLOUDS ACROSS WESTERN NEBRASKA PRODUCING MVFR.
THURSDAY...SHOWERS INCREASING IN COVERAGE AND SPREADING FROM
WEST TO EAST...WITH SCATTERED THUNDERSTORMS. WIDESPREAD MOUNTAIN
OBSCURATION. MVFR PREVAILS WITH SHOWERS AND THUNDERSTORMS.
GUSTY AND ERRATIC WINDS NEAR THUNDERSTORMS ALONG WITH LOCALIZED
TURBULENCE. COVERAGE OF STORMS WILL BE GREATER IN THE WEST AND LEAST
IN THE EAST.
&&
.FIRE WEATHER...
ISSUED AT 350 AM MDT THU AUG 14 2014
WIDESPREAD WETTING RAINS TODAY BEGINNING OVER CARBON COUNTY...THEN
SPREADING EAST. THIS IS DUE TO A UPPER LEVEL LOW PRESSURE SYSTEM
MOVING SLOWLY NORTHEAST AND INTERACTING WITH MONSOONAL MOISTURE
OVER THE AREA. THIS LOW WILL KEEP UNSETTLED WEATHER OVER SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE THROUGH FRIDAY AFTERNOON AS THE LOW
SLOWLY MOVES OUT OF THE AREA. DRIER CONDITIONS AFTER FRIDAY
AFTERNOON AS WESTERLY WINDS RETURN. AFTERNOON HUMIDITIES SATURDAY
AND SUNDAY WILL LOOK TO BECOME CRITICAL WEST OF THE LARAMIE RANGE.
GUSTY WESTERLY WINDS AS WELL BOTH AFTERNOONS THAT COULD REACH
CRITICAL CRITERIA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...RUBIN
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
950 AM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 950 AM MDT THU AUG 14 2014
A COUPLE OF OPPOSING FORCES WILL IMPACT THINGS TODAY. FIRST ON THE
SYNOPTIC SCALE LATEST RAP ANALYSES SHOW SLOWLY INCREASING
QUASIGEOSTROPHIC SUBSIDENCE BEGINNING TO OVERSPREAD WESTERN
COLORADO. THIS MODEL AS WELL AS OTHERS SHOW THIS INCREASING TREND
IN BOTH STRENGTH AND AREAL COVERAGE OF THE SUBSIDENCE THROUGHOUT
THE DAY AND INTO THIS EVENING. IN ADDITION LOW LEVEL HEIGHT FALLS
TO OUR EAST ARE PRODUCING DOWNSLOPE FLOW EAST OF THE MOUNTAINS.
NEITHER OF THESE PHENOMENA BODE WELL FOR AIDING CONVECTIVE
ACTIVITY. ON THE OTHER HAND PRECIPITABLE WATER VALUES ARE
SUBSTANTIAL...1.40 CURRENTLY AT GJT WITH 1.10 AT BOULDER.
ADDITIONALLY THERE IS AN ONGOING AREA OF CONVECTION APPROACHING
THE CONTINENTAL DIVIDE AND SOME HOLES SHOWING UP IN THE MIDLEVEL
CLOUD DECK. BOTH OF THESE ARE GOOD SIGNS OF COURSE. WHICH IS GOING
TO WIN OUT IS STILL IN QUESTION BUT THE PRESENT FORECAST SEEMS
REASONABLE CONSIDERING ALL OF THE ABOVE FACTORS. CONSEQUENTLY
THERE ARE NO CHANGES PLANNED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 400 AM MDT THU AUG 14 2014
FORECAST ON TRACK WITH TRENDS OF HIGHER CHANCES OF SHOWERS AND
COOLER TEMPERATURES TODAY OVER THE FRONT RANGE AND NORTHEAST
PLAINS. WATER VAPOR IMAGERY SHOWING THE RIDGE ALOFT SHIFTING EAST
INTO THE CENTRAL PLAINS WHILE A WEAK WAVE ALOFT NOW LIFTING
NORTHEAST OVER WESTERN COLORADO AND EASTERN UTAH. RADAR IMAGERY
SHOWING GOOD COVERAGE OF SHOWERS OVER WESTERN COLORADO AND THIS
SWATH OF SHOWERS WILL GRADUALLY SHIFT EAST OVER BOU CWA MOUNTAINS
DURING THE MORNING HOURS. INTEGRATED PW VALUES FROM GPS SHOWING
SUBSTANTIAL INCREASE OF AROUND A THIRD OF AN INCH IN THE PAST
18 HRS AND VALUES ARE NOW OVER AN INCH OF PRECIPITABLE WATER.
DESPITE THE INCREASE IN MOISTURE LEVELS...THE INSTABILITY IS NOT
ALL THAT GREAT TODAY GIVEN CONSIDERABLE CLOUD COVER AHEAD OF THE
WAVE. THIS WILL RESULT IN COOLER AFTERNOON TEMPERATURES AND LESS
INSTABILITY WITH SURFACE BASED CAPES LESS THAN 500J/KG OVER THE
FRONT RANGE. SOMEWHAT BETTER INSTABILITY OVER THE FAR NORTHEAST
PLAINS GIVEN HIGHER DEWPOINTS IN THE LOWER 60S AND POTENTIAL
HIGHER CAPES UP AROUND 1000J/KG. EXPECT HEAVY RAIN AND GUSTY
WINDS WITH THE SHOWERS AND STORMS TODAY. GIVEN STORM MOTIONS OF
10-15KT EXPECT OVERALL FLASH FLOOD THREAT ON THE LOW SIDE DESPITE
THE HIGH MOISTURE VALUES. BURN SCARS WILL HAVE THE HIGHEST IMPACT
FOR FLOOD POTENTIAL BUT NOT WIDE SPREAD ENOUGH TO ISSUE ANY FLASH
FLOOD WATCHES. BASED ON LATEST MODEL CONSENSUS MOST OF THE STORMS
MAY BE DONE OVER THE MOUNTAINS/ADJ PLAINS AROUND 00Z AND THEN
ENDING OVER THE PLAINS BY MIDNIGHT. WILL MAKE SOME ADJUSTMENTS FOR
FASTER ENDING OF STORMS DURING THE EVENING FROM WEST TO EAST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 400 AM MDT THU AUG 14 2014
THE SHORTWAVE TROUGH PASSING OVER THE FCST AREA TODAY WILL HAVE
MOVED EAST OF THE STATE BY EARLY ON FRIDAY AS THE UPPER RIDGE
REGAINS ITS HOLD ON THE FOUR CORNERS REGION. WITH THE CORE OF THE
UPPER RIDGE IN THIS POSITION THE RECENT NORTHWARD INTRUSION OF
MONSOON MOISTURE WILL SHUT OFF...LEADING TO DRIER AND WARMER
CONDITIONS ACROSS THE FORECAST AREA FOR FRIDAY AND SATURDAY. HOWEVER
THERE SHOULD BE SUFFICIENT MID-LEVEL MOISTURE AROUND TOGETHER WITH
STG SOLAR HEATING TO GENERATE ISOLATED TO SCATTERED T-STORMS OVER
AND NEAR THE FRONT RANGE MTNS BOTH DAYS. AND WITH THE RIDGE AXIS
SITTING OVER THE UTAH/COLORADO LINE...THE LIGHT FLOW ALOFT WILL BE
NWLY. IN THE PRESENCE OF A LOW CAPE ENVIRONMENT...THE FEW HIGH-
BASED STORMS THAT MANAGE TO DRIFT SEWRD OFF THE FRONT RANGE SHOULD
QUICKLY COLLAPSE BEFORE VENTURING TOO FAR OUT ONTO THE PLAINS.
NEAR AVERAGE TEMPERATURES ARE FCST FOR BOTH DAYS.
FOR THE PERIOD SUNDAY-MONDAY...MODELS SHOW TO UPPER RIDGE CONTINUING
ITS SLOW WESTWARD MIGRATION OVER THE GREAT BASIN AND DESERT
SOUTHWEST AS A MORE ORGANIZED SHORTWAVE TROUGH TRACKS EWRD ACROSS
MONTANA AND WYOMING ON SUNDAY...AND ACROSS THE NORTHERN GREAT
PLAINS ON MONDAY. MODELS SHOW THE SOUTHERN TIP OF THIS TROUGH
BRUSHING NERN COLORADO LATE ON SUNDAY...WITH POSSIBLY ANOTHER
GLANCE OF THIS EXITING TROUGH ON MONDAY. THIS SECOND BRUSH WITH
THE TROUGH MAY INCLUDE A WEAK COLD FRONT WHICH MODELS SHOW
BACKING THRU NERN COLORADO DURING THE MORNING HOURS. DO NOT EXPECT
MUCH COOLING WITH ITS ARRIVAL...BUT THE LIGHT...SLIGHTLY MORE
MOIST E-NELY UPSLOPE FLOW BEHIND THE FRONT WILL HELP PRODUCE
ISOLATED LATE DAY T-STORMS OVER AND NEAR THE FRONT RANGE.
DURING THE TUESDAY-WEDNESDAY TIME FRAME...THE AIRMASS OVER NERN
COLORADO TURNS DRIER AS THE UPPER RIDGE OUT WEST FLATTENS AS YET
ANOTHER MORE POTENT UPPER TROUGH TRACKS EAST ALONG THE NWRN
U.S./SWRN CANADA BORDER. THIS PLACES COLORADO UNDER ZONAL FLOW
RESULTING IN LITTLE DAY-TO-DAY CHANGE IN TEMPERATURE.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 950 AM MDT THU AUG 14 2014
CURRENT TAFS APPEAR IN ORDER AND DO NOT FORESEE ANY BIG CHANGES
NEEDED WITH THE 18Z ISSUANCE.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...ET
SHORT TERM...ENTREKIN
LONG TERM...BAKER
AVIATION...ET
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
910 AM EDT THU AUG 14 2014
.DISCUSSION...
CURRENT-THIS AFTERNOON...UPPER LEVEL TROUGHING OVER THE EASTERN
THIRD OF THE UNITED STATES KEEPS BOTH THE UPPER LEVEL AND SURFACE
RIDGES SOUTH OF CENTRAL FLORIDA. STATIONARY SURFACE FRONT STRETCHES
FROM AROUND SAVANNAH GEORGIA TO THE PENSACOLA FLORIDA AREA THEN
SOUTHWEST TO AROUND BROWNSVILLE TEXAS PER THE LATEST SURFACE FRONT
ANALYSIS. CONTINUED SOUTH TO SOUTHWEST LOW LEVEL FLOW WITH AN
AFTERNOON SOUTHEAST SEA BREEZE FROM CAPE CANAVERAL SOUTH DUE TO A
WEAKER PRESSURE GRADIENT THAN PAST DAYS. RADARS ALREADY DETECTING
SHOWERS AND STORMS IN THE EASTERN GULF OF MEXICO COMING ASHORE FROM
THE FLORIDA BIG BEND AREA TO MARCO ISLAND ON THE SOUTHWEST FLORIDA
COAST. THE SHOWERS COMING ASHORE FROM CEDAR KEY TO SARASOTA COULD
MAKE IT TO THE WESTERN PORTIONS OF LAKE ORANGE AND OSCEOLA COUNTIES
LATE MORNING. THE SHOWERS THEN TRACK ACROSS THE REST OF EAST CENTRAL
FLORIDA WITH LIGHTNING STORMS DEVELOPING BY EARLY AFTERNOON DUE TO
DAYTIME HEATING AND A VERY MOIST ATMOSPHERE AS INDICATED BY THE
TAMPA...CAPE CANAVERAL AND JACKSONVILLE MORNING SOUNDINGS ALL
SHOWING PRECIPITABLE WATER VALUES ABOVE 2 INCHES OF WATER.
MORNING ZONES UPDATE WILL LOOK AT ANY CHANGES NEEDED TO THE VARIOUS
WIND GRIDS.
PREVIOUS ZONES DISCUSSION
TODAY-TONIGHT...AS IT HAS BEEN FOR AROUND THE PAST WEEK...THERE
REMAINS VERY LITTLE CHANGE IN THE LARGER SYNOPTIC PATTERN IN PLACE
ACROSS THE STATE. DEEP TROUGH ACROSS THE NORTHEASTERN US KEEPS THE
ATLANTIC RIDGE AXIS SUPPRESSED TO OUR SOUTH...TODAY REMAINING SOUTH
OF THE STATE ACROSS THE FLORIDA STRAITS.
OVERALL GRADIENT LOOKS WEAKER TODAY LEADING TO LIGHTER
WEST-SOUTHWEST FLOW. THIS SHOULD ALLOW FOR SLIGHTLY FASTER...AND
MORE EXPANSIVE...DEVELOPMENT OF THE EAST COAST SEA BREEZE AND THIS
IS REFLECTED IN THE LOCAL HRRR AND WRF. EVEN THE GFS AND ECMWF HINT
AT A SEA BREEZE ALONG THE TREASURE COAST. HOWEVER STILL DON`T EXPECT
MUCH INLAND PENETRATION MUCH PAST THE IMMEDIATE COAST OR WEST SIDE
OF THE INDIAN RIVER LAGOON.
CENTRAL FLORIDA WILL BE MORE SOLIDLY UNDER THE INFLUENCE OF THE
LOW-MID LEVEL MOISTURE LEFT BEHIND BY THE SURFACE FRONT THAT DIED
OUT TO OUR NORTH EARLIER THIS WEEK. WHILE THIS SHOULD LEAD TO A
LITTLE BETTER COVERAGE...OVERALL CONVECTIVE EVOLUTION REMAINS
SIMILAR WITH STORMS ALONG THE WEST COAST SEA BREEZE PUSHING EAST
THROUGH THE AFTERNOON. ISOLATED SHOWERS AND STORMS WILL ALSO BE
POSSIBLE ALONG THE EAST COAST SEA BREEZE WHERE IT DOES DEVELOP
BEFORE THE EASTWARD MOVING CONVECTION REACHES IT. COVERAGE WILL
INCREASE THROUGH THE AFTERNOON DUE TO VARIOUS BOUNDARY COLLISIONS.
AS IN PREVIOUS LATE AFTERNOONS AND EVENINGS STORMS TO END AROUND
SUNSET...LOSS OF DAYTIME HEATING AND BOUNDARY COLLISIONS SLOWING
DOWN AND ENDING LATE EVENING. LOW AND MID LEVEL DEBRIS CLOUDS
DISSIPATE AND SKIES TO BECOME PARTLY CLOUDY TO MOSTLY CLEAR LATE
NIGHT.
FRIDAY-SATURDAY...HIGHER RAIN CHANCES WILL CONTINUE INTO THE START
OF THE UPCOMING WEEKEND WITH WSW LOW LVL FLOW AND DEEP MOISTURE WITH
PRECIPITABLE WATER VALUES AROUND TWO INCHES OR GREATER INTO SATURDAY
ACROSS EAST CENTRAL FL AHEAD OF A STALLED FRONTAL BOUNDARY ACROSS S
GA AND FL PANHANDLE. MID LVL IMPULSES ARE PROGGED TO MOVE ACROSS THE
NRN FLORIDA PENINSULA FRIDAY INTO SATURDAY WHICH WILL PROVIDE
ADDITIONAL ORGANIZATION FOR STORM DEVELOPMENT BY LATE MORNING INTO
THE AFTERNOON EACH DAY. SHOULD SEE A LATE AFTERNOON SEA BREEZE NEAR
THE COAST EACH AFTERNOON BUT IT IS NOT EXPECTED TO PUSH VERY FAR
INLAND. SHOWER AND THUNDERSTORM CHANCES WILL BE AROUND 50 PCT WITH
HIGH TEMPERATURES AROUND 90/LWR 90S NEAR THE COAST TO LWR-MID 90S
OVER THE INTERIOR. LOWS WILL BE IN THE 70S.
SUNDAY...THE LOW LVL RIDGE AXIS WILL BEGIN TO LIFT NORTHWARD TWD
LAKE OKEECHOBEE WITH LIGHTER LOW LVL WINDS ACROSS SRN SECTIONS AND
LIGHT SW FLOW ACROSS THE NORTH. OVERALL MOISTURE LEVELS WILL BE ON
THE DECREASE WITH THE MID LVL RIDGE STARTING TO BUILD OVER SRN
SECTIONS. THIS SHOULD LOWER RAINFALL CHANCES INTO THE LOWER CHANCE
CATEGORY FROM 30-40 PCT WITH THE HIGHER CHANCES ACROSS INTERIOR
SECTIONS IN THE AFTERNOON. ANOTHER HOT AFTERNOON WITH HIGHS IN THE
LOWER 90S COAST TO MID 90S INTERIOR.
MON-WED...THE GFS HAS BACKED OFF ON DEEPER MOISTURE MAKING IT TO THE
AREA WITH PRONOUNCED DRYING PROGGED NEAR THE LOW-MID LYR RIDGE AXIS
WHICH WILL BE LIFTING TWD E CENTRAL FL EARLY NEXT WEEK. THE 00Z
ECMWF IS ALSO SHOWING THE DRYING TREND WITH DECREASING MOISTURE IN
THE H8-H5 LAYER BY MON-TUE. HAVE LOWERED RAIN CHANCES TO THE 20-30
PCT RANGE MON-WED OF NEXT WEEK WITH HIGHER CHANCES ACROSS INTERIOR
SECTIONS LATE IN THE DAY WITH SEA BREEZE INTERACTIONS. IT WILL
CONTINUE HOT WITH HIGHS IN THE LOWER 90S ALONG THE COAST AND MID 90S
OVER THE INTERIOR. LOWS WILL BE IN THE 70S.
&&
.AVIATION...
VFR WITH FEW-SCT025 BY 15Z. VCTS SCT-BKN040CB BY 18Z. TEMPO 3-5SM
TSRA SCT-BKN035-045CB 20Z-24Z.
PREVIOUS AVIATION DISCUSSION
PREVAILING VFR THROUGH 15Z. ISOLD TSRA DEVELOPING ACROSS REGION
AFTER 16Z...WITH SCT TSRA MOVING FROM WEST TO EAST ACROSS STATE WITH
WEST COAST SEA BREEZE THROUGH AFTERNOON. EAST COAST SEA BREEZE
DEVELOPING AFTER 17Z...REACHING KFPR/KSUA/KCOF...BUT LIKELY
REMAINING JUST EAST OF KVRB/KMLB/KTIX. BEST COVERAGE OF TSRA ALONG
COAST...WITH A FEW PRODUCING G35KTS ESPECIALLY WHERE THEY COLLIDE
WITH EAST COAST SEA BREEZE FROM KXMR SOUTHWARDS ALONG IMMEDIATE
COAST.
&&
.MARINE...
CURRENT-THIS AFTERNOON...BUOYS RECORDING SOUTHWEST WINDS AROUND 10
KNOTS AND 1 TO 2 FOOT SEAS OUT TO 20NM AND TO 3 FEET OUT 120NM.
SHORT PERIOD SEAS WILL MAKE FOR A BUMPY RIDE. BOATERS BEST TO KEEP
AN EYE TO THE WEST AFTER NOON TIME FOR SHOWERS AND LIGHTNING STORMS
APPROACHING FROM THE WEST AND SOUTHWEST. GUSTS TO 30 KNOTS POSSIBLE
WITH THE STRONGER STORMS AND FREQUENT LIGHTNING POSSIBLE
INTRACOASTAL AND NEARSHORE WATERS CAPE CANAVERAL SOUTH AS THE
PREVAILING SOUTHWEST TO WEST FLOW INTERACTS WITH THE EAST COAST SEA
BREEZE AND STORMS COMING OFF THE MAINLAND.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...PREVAILING SOUTHWEST FLOW CONTINUES THROUGH THE
PERIOD AS RIDGE AXIS REMAINS WELL TO THE SOUTH ACROSS THE FLORIDA
STRAITS. 10-15KTS THROUGH MID MORNING BECOMING SOUTH-SOUTHWEST
5-10KTS INTO THE AFTERNOON. LIGHTER FLOW SHOULD ALLOW MORE OF AN
EAST COAST SEA BREEZE WITH WINDS NEARSHORE SOUTH OF THE CAPE
BECOMING SOUTH-SOUTHEAST DURING THE AFTERNOON. SEAS 1-2FT WITH UP TO
3 FT WELL OFFSHORE. DOMINANT PERIODS STILL A SOMEWHAT CHOPPY
3-5SEC...MIXED WITH 8-10SEC.
BOATERS ON THE INTRACOASTAL AND NEARSHORE WATERS SHOULD KEEP AN EYE
TO THE WEST FOR APPROACHING STORMS AND SEEK SAFE HARBOR TO RIDE OUT
THE STORMS.
SW-S WINDS TO 10 TO 15 KNOTS FRI-SAT WITH OFFSHORE MOVING SHOWERS
AND LIGHTNING STORMS. THE SFC RIDGE WILL BUILD NWD TWD THE SRN
WATERS EARLY NEXT WEEK WITH S WINDS ACROSS THE SRN WATERS AND SW
WINDS NORTH OF THE CAPE. SEAS 1-2 FT NEAR SHORE TO 2-3 FT OFFSHORE.
SHOULD SEE A LOWER COVERAGE OF SHOWER/STORMS AFFECTING THE ATLC
SUNDAY INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 92 76 90 76 / 50 30 50 30
MCO 95 76 92 75 / 50 30 50 30
MLB 92 75 90 76 / 50 30 50 30
VRB 92 75 91 75 / 50 30 50 30
LEE 94 77 93 77 / 50 30 50 20
SFB 95 77 93 77 / 50 30 50 30
ORL 94 77 94 78 / 50 30 50 30
FPR 91 74 91 75 / 50 30 50 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...WIMMER
IMPACT WX...CRISTALDI
PUBLIC SVC..GLITTO
Area Forecast Discussion
NATIONAL WEATHER SERVICE LINCOLN IL
953 AM CDT Thu Aug 14 2014
.UPDATE...
ISSUED AT 952 AM CDT THU AUG 14 2014
Cold front was located roughly along the I-74 corridor this
morning, where winds shift from northwest to northeast. No
significant temperature difference immediately along the front,
but much drier dew points (upper 40s/lower 50s) are upstream in
northeast Illinois. Latest HRRR continues to show some very light
showers/sprinkles speckled along the front during the afternoon,
which has already been accounted for in the hourly weather grids.
Little change was needed to the existing grids, except to lower
the dew points across the northeast CWA as the drier air moves in
from the northeast.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 328 AM CDT THU AUG 14 2014
Another spoke of energy is pivoting around the pesky upper low over
eastern Canada. This particular wave of interest is diving across
the western Great Lakes, and is helping to push a weak frontal
boundary south across Illinois. In the latest surface analysis, this
surface boundary lies in the vicinity of the I-74 corridor across
central Illinois. While this boundary is weak and moisture starved,
a main concern today is if it will successfully produce any rainfall.
Some spotty showers have been along the boundary through the night,
although a more notable impact has been a thick band of AC. Much of
the model guidance has been insisting for days that some rainfall
will accompany this front today, and even some of the short-term
mesoscale models are now doing the same. Still, given what has
occurred upstream, and progged moisture profiles in local forecast
soundings, have a hard time believing we`ll see more than virga
and/or sprinkles. So, plan to keep PoPs below the measurable rain
threshold today (15%), but will mention a slight chance of sprinkles
accompanying the front as it sinks south. The front pretty much
washes out by tonight, so do not expect the risk of sprinkles to
extend beyond this afternoon. Below normal temperatures will
continue through tonight, especially as you head north/east of the
decaying front.
&&
.LONG TERM...(Friday through Wednesday)
ISSUED AT 328 AM CDT THU AUG 14 2014
The nice stretch of summer weather will continue through Friday
evening with most areas staying dry and temperate as 1018 mb surface
high pressure ridge settles east of IL into the Ohio river valley on
Friday. Partly sunny skies expected on Friday with highs mostly in
the lower 80s and dew points elevating into the low to mid 60s Friday
afternoon with SSE winds 5-10 mph.
Most models now keep central/SE IL dry Friday evening with some qpf
moving into mainly western areas after midnight Friday night as
short waves eject east from the central Rockies across the MO
valley. Better chance of showers and thunderstorms to spread further
east during Saturday especially Saturday afternoon into Saturday
night. SPC has slight risk of severe storms Saturday SW of central
IL CWA but 5% risk of hail/wind as far NE as I-74 due to increase
wind shear and instability as dew points rise into the upper 60s to
around 70F by Sat afternoon.
Northwest upper level flow will become more zonal early next week as
upper level trof/low moves into IL. Weather to be more unsettled
from this weekend into at least early next work week. Models still
differ on timing of this feature but currently have daily chances of
showers and thunderstorms from this weekend through early next work
week with highest chances Saturday night through Monday. Tropical
humidity will return to IL during this weekend and linger into next
work week as dew points climb into the upper 60s and lower 70s. Highs
80-85F this weekend and Monday will climb into the mid to upper 80s
by middle of next week with a few spots in SW areas approaching 90.
&&
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
ISSUED AT 659 AM CDT THU AUG 14 2014
A weak frontal boundary will sink southward across the central
Illinois terminals today. This front will be accompanied by a band
of mid level cloud cigs (VFR), and possibly a few sprinkles and/or
virga. Have only included a VCSH mention due to the very spotty
nature of any sprinkles. Otherwise, quiet/VFR conditions will be the
rule through the 12Z TAF valid time. Light/variable winds should
prevail with weak high pressure in the vicinity once the front
passes through.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BAK
LONG TERM...07
AVIATION...BAK
AREA FORECAST DISCUSSION
NWS DES MOINES IA
637 AM CDT THU AUG 14 2014
.SHORT TERM /TODAY/...
ISSUED AT 340 AM CDT THU AUG 14 2014
RIDGE OF HIGH PRESSURE OVER THE NORTHERN GREAT LAKES AND SOUTHERN
CANADA WILL HOLD FOR ANOTHER DAY TODAY AS IT SLOWLY DRIFTS EAST.
PATCHY FOG...A FEW AREAS OF DENSE FOG THIS MORNING SHOULD LIFT
QUICKLY BY 13Z SHORTLY AFT SUNRISE. LOW PRESSURE OVER THE CENTRAL
ROCKIES WILL MOVE LITTLE THROUGH THIS AFTERNOON. HOWEVER...A WARM
FRONT STRETCHING EAST SOUTHEAST FROM THE LOW OVER SOUTHERN KANSAS
WILL BEGIN TO LIFT NORTH DURING THE AFTERNOON INTO NORTHERN
KANSAS. WARM AIR ADVECTION ALOFT AND A WEAK WAVE WILL CONTINUE AN
AREA OF SHOWERS AND THUNDERSTORMS OVER SOUTH DAKOTA WHICH SHOULD
GENERALLY REMAIN NORTHWEST OF THE REGION THROUGH LATE TODAY.
CIRRUS CONTINUE TO SPILL OVER THE H700 RIDGE TONIGHT...AND EXPECT
SOME HIGH CLOUDS TO CROSS THE REGION THIS AFTERNOON AND TONIGHT.
BY LATE AFTERNOON THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND ISO
THUNDER FAR NORTHWEST AS THE NORTHERN STREAM SHORTWAVE APPROACHES
THE AREA. BOTH SYNOPTIC SCALE MODELS AND THE HRRR INCREASE FORCING
ACROSS THE FAR NORTHWEST THIS AFTERNOON. HIGHS TODAY WITH THE
POTENTIAL FOR MORE CLOUDS NORTHWEST AND INCREASING HIGH CLOUDS
ELSEWHERE...SHOULD HOLD HIGHS IN THE UPPER 70S TO LOWER 80S REGION
WIDE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 340 AM CDT THU AUG 14 2014
THE FIRST WAVE ARRIVES TONIGHT WITH MOISTURE INCREASING ALOFT INTO
AN UPPER LEVEL BOUNDARY ACROSS THE REGION. MODELS CONTINUE TO SHOW
INCREASING THETAE ADVECTION FROM 00Z TO 12Z FRIDAY OVER THE FORECAST
AREA. FLOW AT H850 REMAINS WEAK WITH SLOWLY EXITING HIGH PRESSURE TO
THE EAST. THIS WILL ALLOW ANY CONVECTION TO GRADUALLY WEAKEN
OVERNIGHT AS IT PUSHES ACROSS THE NORTHEAST WITH SHOWERS AND PERHAPS
ISOLATED THUNDER THROUGH FRIDAY MORNING. BY FRIDAY AFTERNOON...
DAYTIME HEATING...INCREASED MOISTURE TRANSPORT AND STRENGTHENING
H850 WINDS SHOULD INCREASE THE SHOWERS AND THUNDERSTORM ACTIVITY
OVER THE AREA ACROSS THE NORTHEAST AND SOUTHWEST. RAINFALL AMOUNTS
WILL REMAIN LIGHT THROUGH FRIDAY AFTERNOON. BY 00Z SATURDAY THE
MODELS ARE IN GENERALLY GOOD AGREEMENT HAVING THE WARM FRONT NEAR
THE IA MO BORDER AS AN H850 LOW APPROACHES WITH ANOTHER PUSH OF
STRONGER THETAE ADVECTION...H850 WINDS TO 25KT INCREASING TO 40KTS
BY 06Z OVER THE SOUTH. WITH THE STRONG FORCING AND BOUNDARY ALOFT...
THERE IS AN INCREASING CHANCE FOR AN MCS TO FORM OVER NORTHWEST MO
AND LIFT EAST NORTHEAST INTO SOUTHERN IOWA THROUGH THE NIGHT. BUFKIT
SOUNDINGS OVER SOUTHERN IOWA INDICATE SATURATION FROM H800 TO H300.
PRECIPITABLE WATER VALUES INCREASE TO 2 TO 2.25 INCHES BY 06-12Z
SATURDAY OVER SOUTHERN IOWA. AS WELL...WARM CLOUD DEPTHS TO 14 TO
15KFT DURING THIS TIME. THIS SHOULD PROMOTE VERY EFFICIENT RAINFALL
ACROSS THE BOUNDARY WITH ELEVATED CONVECTION. WITH INSTABILITY
VALUES DECREASING OVERNIGHT... THE MAIN CONCERN WILL BE HEAVY
RAINFALL. WITH THE FORECAST PARAMETERS...THERE IS A POTENTIAL FOR 2
TO +3 INCH TOTALS WITH ANY MCS THAT DEVELOPS. WILL CONTINUE TO
REFINE DETAILS OVER THE NEXT SEVERAL PACKAGES. AS THE CONVECTION
PULLS EAST SATURDAY MORNING THE UPPER LEVEL LOW WILL SLOWLY DRIFT
EAST. THIS WILL KEEP SHOWERS AND SCT THUNDER IN THE FORECAST FOR
SATURDAY. HIGHS FRIDAY WILL BE IN THE 70S TO LOWER 80S WITH THE
COOLER READINGS OVER THE NORTH. SATURDAY WILL SEE A MORE UNIFORM DAY
WITH MOST AREAS NEAR 80 FOR THE AFTERNOON AS CLOUD COVER AND THE
CHANCE FOR RAIN HOLDS. DEW POINTS WILL BE CLIMBING OVER THE NEXT
SEVERAL DAYS...WITH MORE UNCOMFORTABLE CONDITIONS EXPECTED. THE
SHOWER AND THUNDERSTORM POTENTIAL WILL LAST INTO SUNDAY AS THE UPPER
LEVEL SYSTEM PULLS EAST OF THE REGION. ON MONDAY THE AREA SHOULD BE
IN BETWEEN SYSTEMS WITH LITTLE CHANCE FOR ANY RAIN CENTRAL...SLIGHT
CHANCES EAST AND WEST. THE NEXT NORTHERN STREAM WAVE RETURNS FOR
MONDAY NIGHT AND TUESDAY WITH ANOTHER WARM FRONT ADVANCING EAST
ACROSS THE REGION. THIS SHOULD BRING AN ADDITIONAL CHANCE FOR SOME
THUNDERSTORMS MONDAY NIGHT AND TUESDAY WITH WARMER TEMPERATURES FOR
WEDNESDAY. IN FACT...H850 TEMPS ARE EXPECTED TO INCREASE TO 20C BY
WEDNESDAY WITH HIGHS IN THE MID 80S AND DEW POINTS BACK NEAR 70.
&&
.AVIATION...14/12Z
ISSUED AT 631 AM CDT THU AUG 14 2014
FEW CONCERNS FOR TODAY. PATHCY FOG STILL EVIDENT AT
KOTM...OTHERWISE SHOULD BE BACK TO VFR BY 13Z. HIGH CLOUDS RIDING
RIDGE WILL GLIDE ACROSS AREA TODAY WITH SCT CLOUDS AFT 17Z. WARM
AIR ADVECTION CONVECTION/SHOWERS AFT 03Z TO AFFECT NORTHWEST AREAS
BUT CONFIDENCE ON COVERAGE REMAINS LOW. HAVE ADDED VCSH TO KFOD
AND KMCW FOR NOW AFT 03-08Z. THIS WILL SLIDE ESE BY 12Z FRIDAY./REV
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...REV
LONG TERM...REV
AVIATION...REV
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1123 AM EDT THU AUG 14 2014
.UPDATE...
ISSUED AT 1120 AM EDT THU AUG 14 2014
SOME SPRINKLES AND LIGHT RAIN SHOWERS ARE WORKING ACROSS NORTHEASTERN
KY AND WILL AFFECT PARTS OF THE BIG SANDY REGION THROUGH EARLY
AFTERNOON. MID AND HIGH CLOUDS ARE WORKING ACROSS THE REMAINDER OF
THE CWA AND SHOULD THROUGH EARLY TO MID AFTERNOON. OTHERWISE...A COLD
FRONT IS APPROACHING THE REGION FROM THE NORTH AND IS NEARING THE OH
RIVER AT THIS TIME. THE BOUNDARY APPEARS TO CURRENTLY EXTEND FROM
JUST NEAR THE INTERSTATE 79 CORRIDOR FROM THE PIT AND LBE AREA SOUTH
THROUGH MGW AND CKB AND THEN WEST BETWEEN PKB AND CRW...NORTH OF HTS
AND BETWEEN DAY AND CVG AND THEN WEST AND NORTHWEST ACROSS CENTRAL IN
AND IL. SFC DEWPOINTS REMAIN NEAR 60 ACROSS MUCH OF THE AREA.
THE RECENT HRRR RUNS AS WELL AS THE 12Z NAM AND TO SOME EXTENT RECENT
RAP RUNS AND EVEN 6Z GFS SUPPORT SOME REDEVELOPMENT AS A SHORTWAVE
ROTATES THROUGH THE SOUTHERN GREAT LAKES REGION AND INTO THE OHIO
VALLEY AND SEND THE BOUNDARY DOWN INTO EASTERN KY. THE 9Z SREF ALSO
HAS SOME HIGHER POPS DURING THE AFTERNOON AND EVENING. WITH THIS IN
MIND...OPTED TO GO WITH SOME ISOLATED TO SCATTERED POPS LATER TODAY
FOR MUCH OF THE CENTRAL AND NORTHEAST PART OF THE CWA. THEN INTO THE
EVENING...WE OPTED TO CARRY ISOLATED POPS ACROSS THE CENTRAL...SOUTHEAST
PART OF THE AREA AS WELL AS THE SME AND LOZ AREAS. AS THIS ACTIVITY
BEGINS TO DEVELOP THIS AFTERNOON THIS MAY NEED SOME FINE TUNING.
ALONG WITH THIS...CLOUD COVER WAS INCREASED FOR MUCH OF THE REMAINDER
OF THE DAY AND INTO THE OVERNIGHT HOURS.
UPDATE ISSUED AT 745 AM EDT THU AUG 14 2014
THE FRONT IS SETTLING INTO THE AREA WITH SOME SPRINKLES ALREADY NOTED
ON RADAR NORTH OF INTERSTATE 64. HAVE ADDED THIS TO THE POP AND WX
GRIDS. THE FOG IS FOUND MAINLY IN THE VALLEYS THROUGH EAST KENTUCKY
WITH SOME LOCALLY DENSE PATCHES. DID ALSO FINE TUNE THE T/TD GRIDS
PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EDT THU AUG 14 2014
06Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE THROUGH THE TENNESSEE
VALLEY WITH A MOSTLY DRY COLD FRONT TO OUR NORTH DROPPING SOUTH
THROUGH THE OHIO VALLEY. THIS HAS LEFT MOST OF EAST KENTUCKY UNDER
CLEAR SKIES WITH A DRY AIR MASS IN PLACE. COMBINED WITH LIGHT
WINDS...THE RADIATIVE COOLING IS HELPING TO DROP TEMPERATURES INTO
THE 50S THROUGH THE AREA. IN THE VALLEYS THESE TEMPS ARE GETTING
CLOSE TO THE DEWPOINTS RESULTING IN THE FORMATION OF FOG ALONG WITH
THE POTENTIAL FOR LOCALLY DENSE PATCHES. HAVE ALLOWED FOR THIS IN THE
GRIDS THROUGH 13Z. ASSOCIATED WITH THE DESCENDING FRONT TO THE
NORTH...A PATCH OF MID LEVEL CLOUDS ARE SETTING INTO NORTHERN
KENTUCKY AND THIS SHOULD LIMIT THE COOLING AND FOG FORMATION IN THOSE
PARTS THROUGH DAWN. THE AREAS OF DENSE FOG WILL BE HIGHLIGHTED IN THE
HWO FOR EARLY THIS MORNING.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT THE RESURGENCE OF THE
UNSEASONABLY DEEP ONTARIO UPPER LOW THROUGH THE DAY WITH ITS
SOUTHWARD PUSH OF ENERGY AND HEIGHT FALLS. THE BEST ENERGY WITH THIS
WILL STAY JUST NORTHEAST OF JKL THROUGH FRIDAY MORNING BEFORE THE LOW
GYRATES BACK FURTHER NORTH DURING THE DAY FRIDAY ALLOWING FOR RISING
HEIGHTS AND A DEPARTING ENERGY STREAM. WITH A SLIGHTLY SLOWER
MOVEMENT TO THE UPPER LOW...THE NAM KEEPS THE LOWER HEIGHTS IN THE
SOUTHERN OHIO VALLEY A BIT LONGER INTO THE DAY FRIDAY. HAVE FAVORED A
GENERAL MODEL BLEND GIVEN THE SIMILARITIES...THOUGH THE HIGHER
RESOLUTION HRRR AND NAM12 WERE GIVEN MORE EMPHASIS FOR THE FIRST
PART OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANTLY COOL AND MOSTLY DRY
DAY UNDER PARTLY CLOUDY TO MOSTLY SUNNY SKIES. THE COLD FRONT WILL
SETTLE INTO NORTHERN PARTS OF THE CWA AND MAKE FOR A THREAT OF
SPRINKLES OR A STRAY SHOWER TODAY. THE MODEL FORECAST SOUNDINGS ARE
UNFAVORABLE FOR THUNDER WITH A MID LEVEL CAP AND LOW CAPE VALUES SO
HAVE KEPT OUT THUNDER FOR THE GRIDS. CANNOT RULE OUT A STRAY SHOWER
INTO THE NIGHT TONIGHT...BUT GIVEN THE LOSS OF DIURNAL HEATING WILL
KEEP IT DRY. AGAIN PATCHY FOG...LOCALLY DENSE...CAN BE ANTICIPATED IN
THE VALLEYS FOR FRIDAY MORNING...BUT PROBABLY NOT AS EXTENSIVE AS
THIS MORNING/S WILL LIKELY END UP. THE FRONT REMAINS AROUND INTO THE
DAY FRIDAY...BUT RISING HEIGHTS WILL KEEP THE RISK OF SPRINKLES OR
SHOWERS TO A MINIMUM...WHILE ANOTHER RELATIVELY COOL SUMMER DAY IS
HAD BY ALL.
USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE
SOME ADJUSTMENTS TONIGHT FOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
AND TONIGHT FOR THE NORTHERN PARTS OF THE AREA...OWING TO THE
FRONT...WAS IN LINE WITH THE GUIDANCE ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 AM EDT THU AUG 14 2014
THE MODELS WERE STILL IN DECENT AGREEMENT IN THE EXTENDED. THE
OVERALL MID AND UPPER LEVEL PATTERNS ARE PROGGED TO FEATURE A RIDGE
OF HIGH PRESSURE WEAKENING AND RETREATING SOUTHEASTWARD OUT OF THE
OHIO AND TENNESSEE VALLEY REGIONS FRIDAY NIGHT AND SATURDAY. THIS
WILL ALLOW THE PERIOD TO START OUT DRY WITH INCREASING CLOUD COVER
AND LIGHT WINDS ON TAP FOR EASTERN KENTUCKY. THE CLOUD COVER WILL BE
IN RESPONSE TO AN AREA OF LOW PRESSURE AND ITS ASSOCIATED FRONTAL
BOUNDARY TAKING SHAPE OVER THE EAST CENTRAL PLAINS AND MOVING
EASTWARD TOWARD THE AREA SUNDAY AND SUNDAY NIGHT. THE INITIAL AREA
OF LOW PRESSURE LOOKS TO MOVE ACROSS THE AREA SUNDAY NIGHT. A
FRONTAL BOUNDARY EXTENDING FROM THIS LOW WILL STALL OUT ALONG THE
TENNESSEE VALLEY REGION EASTWARD TO THE EAST COAST OF THE CONUS. THE
PRESENCE OF THIS BOUNDARY WOULD KEEP A CHANCE OF SHOWERS AND STORMS
IN THE FORECAST FROM EARLY SUNDAY THROUGH THE END OF THE UPCOMING
WORK WEEK. WAVES OF LOW PRESSURE MOVING ALONG THE FRONT WOULD
PROVIDE THE LIFT NEEDED TO SPAWN SHOWERS AND STORMS AS MOISTURE FORM
THE GULF OF MEXICO RIDES UP AND OVER THE FRONT. THE ISSUE AT HAND
WILL BE THE TIMING OF THESE WAVES OF LOW PRESSURE AND HOW MUCH
MOISTURE THEY WILL HAVE TO TAP INTO. BASED ON THIS BIT OF
UNCERTAINTY...DECIDED TO KEEP PRECIPITATION CHANCES BETWEEN 20 AND
40 PERCENT ACROSS THE BOARD...FAVORING THE DAYTIME HOURS FOR PEAK
ACTIVITY WITH LULLS IN THE ACTION DURING THE NIGHTTIME PERIODS.
TEMPERATURES THROUGHOUT THE PERIOD SHOULD BE ABLE TO RECOVER TO
NORMAL VALUES FOR THIS TIME OF YEAR AS THE GULF OF MEXICO OPENS UP
AND WARM MOIST AIR INVADES THE REGION FROM THE SOUTH. HIGHS IN
GENERAL ARE EXPECTED TO BE IN THE MID 80S THROUGHOUT THE PERIOD WITH
OVERNIGHT LOWS IN THE UPPER 60S THE FIRST SEVERAL NIGHTS...TO AROUND
70 BY THE END OF THE WEEK. THE ONE EXCEPTION MIGHT BE FRIDAY NIGHT
BEFORE THE WINDS SHIFT TO THE SOUTH AND THE WARMER AIR FROM THE GULF
MAKES IT WAY INTO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 810 AM EDT THU AUG 14 2014
THE IFR AND VLIFR FOG WILL BURN OFF BETWEEN 12 AND 13Z TODAY...
GIVING WAY QUICKLY TO VFR CONDITIONS AND LIGHT NORTHWEST WINDS THAT
WILL LAST THROUGH EVENING. EXPECT CALM WINDS AND PARTLY CLOUDY SKIES
TO AGAIN LEAD TO SOME FOG AROUND EARLY FRIDAY MORNING. THE FOG SHOULD
NOT BE AS PERVASIVE AS IT IS THIS MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
810 AM EDT THU AUG 14 2014
.UPDATE...
ISSUED AT 745 AM EDT THU AUG 14 2014
THE FRONT IS SETTLING INTO THE AREA WITH SOME SPRINKLES ALREADY NOTED
ON RADAR NORTH OF INTERSTATE 64. HAVE ADDED THIS TO THE POP AND WX
GRIDS. THE FOG IS FOUND MAINLY IN THE VALLEYS THROUGH EAST KENTUCKY
WITH SOME LOCALLY DENSE PATCHES. DID ALSO FINE TUNE THE T/TD GRIDS
PER THE LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND
WEB SERVERS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 315 AM EDT THU AUG 14 2014
06Z SFC ANALYSIS SHOWS WEAK HIGH PRESSURE THROUGH THE TENNESSEE
VALLEY WITH A MOSTLY DRY COLD FRONT TO OUR NORTH DROPPING SOUTH
THROUGH THE OHIO VALLEY. THIS HAS LEFT MOST OF EAST KENTUCKY UNDER
CLEAR SKIES WITH A DRY AIR MASS IN PLACE. COMBINED WITH LIGHT
WINDS...THE RADIATIVE COOLING IS HELPING TO DROP TEMPERATURES INTO
THE 50S THROUGH THE AREA. IN THE VALLEYS THESE TEMPS ARE GETTING
CLOSE TO THE DEWPOINTS RESULTING IN THE FORMATION OF FOG ALONG WITH
THE POTENTIAL FOR LOCALLY DENSE PATCHES. HAVE ALLOWED FOR THIS IN THE
GRIDS THROUGH 13Z. ASSOCIATED WITH THE DESCENDING FRONT TO THE
NORTH...A PATCH OF MID LEVEL CLOUDS ARE SETTING INTO NORTHERN
KENTUCKY AND THIS SHOULD LIMIT THE COOLING AND FOG FORMATION IN THOSE
PARTS THROUGH DAWN. THE AREAS OF DENSE FOG WILL BE HIGHLIGHTED IN THE
HWO FOR EARLY THIS MORNING.
THE MODELS ARE IN PRETTY GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM
PORTION OF THE FORECAST. THEY ALL DEPICT THE RESURGENCE OF THE
UNSEASONABLY DEEP ONTARIO UPPER LOW THROUGH THE DAY WITH ITS
SOUTHWARD PUSH OF ENERGY AND HEIGHT FALLS. THE BEST ENERGY WITH THIS
WILL STAY JUST NORTHEAST OF JKL THROUGH FRIDAY MORNING BEFORE THE LOW
GYRATES BACK FURTHER NORTH DURING THE DAY FRIDAY ALLOWING FOR RISING
HEIGHTS AND A DEPARTING ENERGY STREAM. WITH A SLIGHTLY SLOWER
MOVEMENT TO THE UPPER LOW...THE NAM KEEPS THE LOWER HEIGHTS IN THE
SOUTHERN OHIO VALLEY A BIT LONGER INTO THE DAY FRIDAY. HAVE FAVORED A
GENERAL MODEL BLEND GIVEN THE SIMILARITIES...THOUGH THE HIGHER
RESOLUTION HRRR AND NAM12 WERE GIVEN MORE EMPHASIS FOR THE FIRST
PART OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE ANOTHER PLEASANTLY COOL AND MOSTLY DRY
DAY UNDER PARTLY CLOUDY TO MOSTLY SUNNY SKIES. THE COLD FRONT WILL
SETTLE INTO NORTHERN PARTS OF THE CWA AND MAKE FOR A THREAT OF
SPRINKLES OR A STRAY SHOWER TODAY. THE MODEL FORECAST SOUNDINGS ARE
UNFAVORABLE FOR THUNDER WITH A MID LEVEL CAP AND LOW CAPE VALUES SO
HAVE KEPT OUT THUNDER FOR THE GRIDS. CANNOT RULE OUT A STRAY SHOWER
INTO THE NIGHT TONIGHT...BUT GIVEN THE LOSS OF DIURNAL HEATING WILL
KEEP IT DRY. AGAIN PATCHY FOG...LOCALLY DENSE...CAN BE ANTICIPATED IN
THE VALLEYS FOR FRIDAY MORNING...BUT PROBABLY NOT AS EXTENSIVE AS
THIS MORNING/S WILL LIKELY END UP. THE FRONT REMAINS AROUND INTO THE
DAY FRIDAY...BUT RISING HEIGHTS WILL KEEP THE RISK OF SPRINKLES OR
SHOWERS TO A MINIMUM...WHILE ANOTHER RELATIVELY COOL SUMMER DAY IS
HAD BY ALL.
USED THE CONSSHORT AS A STARTING POINT FOR THE T/TD/WIND GRIDS
THROUGH THE FIRST 24 HOURS AND THE SUPERBLEND THEREAFTER. DID MAKE
SOME ADJUSTMENTS TONIGHT FOR RIDGE AND VALLEY TEMPERATURE
DIFFERENCES. WITH THE POPS...ENDED UP A NOTCH HIGHER THAN MOS TODAY
AND TONIGHT FOR THE NORTHERN PARTS OF THE AREA...OWING TO THE
FRONT...WAS IN LINE WITH THE GUIDANCE ON FRIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 AM EDT THU AUG 14 2014
THE MODELS WERE STILL IN DECENT AGREEMENT IN THE EXTENDED. THE
OVERALL MID AND UPPER LEVEL PATTERNS ARE PROGGED TO FEATURE A RIDGE
OF HIGH PRESSURE WEAKENING AND RETREATING SOUTHEASTWARD OUT OF THE
OHIO AND TENNESSEE VALLEY REGIONS FRIDAY NIGHT AND SATURDAY. THIS
WILL ALLOW THE PERIOD TO START OUT DRY WITH INCREASING CLOUD COVER
AND LIGHT WINDS ON TAP FOR EASTERN KENTUCKY. THE CLOUD COVER WILL BE
IN RESPONSE TO AN AREA OF LOW PRESSURE AND ITS ASSOCIATED FRONTAL
BOUNDARY TAKING SHAPE OVER THE EAST CENTRAL PLAINS AND MOVING
EASTWARD TOWARD THE AREA SUNDAY AND SUNDAY NIGHT. THE INITIAL AREA
OF LOW PRESSURE LOOKS TO MOVE ACROSS THE AREA SUNDAY NIGHT. A
FRONTAL BOUNDARY EXTENDING FROM THIS LOW WILL STALL OUT ALONG THE
TENNESSEE VALLEY REGION EASTWARD TO THE EAST COAST OF THE CONUS. THE
PRESENCE OF THIS BOUNDARY WOULD KEEP A CHANCE OF SHOWERS AND STORMS
IN THE FORECAST FROM EARLY SUNDAY THROUGH THE END OF THE UPCOMING
WORK WEEK. WAVES OF LOW PRESSURE MOVING ALONG THE FRONT WOULD
PROVIDE THE LIFT NEEDED TO SPAWN SHOWERS AND STORMS AS MOISTURE FORM
THE GULF OF MEXICO RIDES UP AND OVER THE FRONT. THE ISSUE AT HAND
WILL BE THE TIMING OF THESE WAVES OF LOW PRESSURE AND HOW MUCH
MOISTURE THEY WILL HAVE TO TAP INTO. BASED ON THIS BIT OF
UNCERTAINTY...DECIDED TO KEEP PRECIPITATION CHANCES BETWEEN 20 AND
40 PERCENT ACROSS THE BOARD...FAVORING THE DAYTIME HOURS FOR PEAK
ACTIVITY WITH LULLS IN THE ACTION DURING THE NIGHTTIME PERIODS.
TEMPERATURES THROUGHOUT THE PERIOD SHOULD BE ABLE TO RECOVER TO
NORMAL VALUES FOR THIS TIME OF YEAR AS THE GULF OF MEXICO OPENS UP
AND WARM MOIST AIR INVADES THE REGION FROM THE SOUTH. HIGHS IN
GENERAL ARE EXPECTED TO BE IN THE MID 80S THROUGHOUT THE PERIOD WITH
OVERNIGHT LOWS IN THE UPPER 60S THE FIRST SEVERAL NIGHTS...TO AROUND
70 BY THE END OF THE WEEK. THE ONE EXCEPTION MIGHT BE FRIDAY NIGHT
BEFORE THE WINDS SHIFT TO THE SOUTH AND THE WARMER AIR FROM THE GULF
MAKES IT WAY INTO THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 810 AM EDT THU AUG 14 2014
THE IFR AND VLIFR FOG WILL BURN OFF BETWEEN 12 AND 13Z TODAY...
GIVING WAY QUICKLY TO VFR CONDITIONS AND LIGHT NORTHWEST WINDS THAT
WILL LAST THROUGH EVENING. EXPECT CALM WINDS AND PARTLY CLOUDY SKIES
TO AGAIN LEAD TO SOME FOG AROUND EARLY FRIDAY MORNING. THE FOG SHOULD
NOT BE AS PERVASIVE AS IT IS THIS MORNING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
632 AM CDT Thu Aug 14 2014
.UPDATE...
Issued at 630 am CDT THU AUG 14 2014
Updated for aviation forecast discussion.
&&
.SHORT TERM...(Today through Saturday)
Issued at 229 AM CDT THU AUG 14 2014
High pressure was centered over the region during the overnight
hours, with a frontal boundary draped across parts of IA, IL, IN and
into OH. Models have been advertising this back door cold front for
several days now. It will continue to sag southwest toward the area
today. A band of mid clouds is seen on satellite and METAR
observations/radar indicate that some spotty showers are resulting
from these clouds. The frontal boundary should reach parts of
southern IL and southwest IN by afternoon or early evening.
Models differ on whether precipitation develops into our CWA
however. The 00Z NAM and latest RUC keep the QPF just north of us,
while the GFS indicate a very small sliver of our northernmost
counties have a chance of seeing a few showers. Some of the hi res
models (ARW/NMM) show a band of spotty showers dropping into parts
of southern IL, southwest IN and parts of KY during the late
afternoon hours. Might opt to throw in some light showers or
sprinkles up in the far north since there may be just enough low
level moisture to bring a few drops to the ground. Will wait and see
what surrounding offices want to do.
Temperatures today should be in the lower to mid 80s, similar to
what occurred yesterday. However, it might be a bit warmer in parts
of SEMO today since winds will become more southerly there.
Whatever precipitation does occur later today should be short lived
as the front disintegrates and high pressure tries to build in behind
it tonight. On Friday, moisture begins to increase which will mean
an increase in cloudiness. Meanwhile, mid/upper heights will begin
rising by late in the week and into weekend, which will mean a bump
in temperatures. Sfc winds will also eventually shift around to the
south as well. We should see upper 80s area wide on Friday and
Saturday.
Next item of business is watching how a mid level short wave moves
across the top of a prominent ridge across the mid CONUS. It is
slated to drop southeast toward the area Friday night into Saturday.
We believe Friday night should be mainly dry but chances for rain
will have to be maintained at least in our northwestern sections for
Saturday. However, the better chances look to arrive Saturday night.
.LONG TERM...(Sunday through Wednesday)
Issued at 229 AM CDT THU AUG 14 2014
A blend of the 00z/12z GFS/GEFS and 12z ECENS was used for this
forecast. This resulted in little change to the inherited PoPs and
resultant temperatures. Temperatures will be geared toward MOS and
CONUS raw model output.
Slow moving upper trof is forecast to approach the CWFA Saturday
night and slowly progress ESE across the region through Sunday
night. Will carry good chance PoPs for convection as a result given
the respectable moisture coupled with mid trop forcing that will
accompany the upper system.
The system will head on to the east Monday. Will linger chance PoPs
over the east, and taper them off west. We may see a lull Monday
night as weak s/wv ridging moves overhead. Inherited 20% values and
see no reason to drop them yet, until a more clear signal is
established.
As some deamplification of the pattern occurs, the WNW flow pattern
across the area will weaken. We will be in broad SSW surface slow as
broad low pressure develops over the plains. Little to key in on
feature wise. The models continue to develop QPF over the region in
what should be a weak but unsettled mid trop flow pattern. Therefore
will carry low chance PoPs during the day Tue/Wed, and taper them
off to slight chances at night.
&&
.AVIATION...
Issued at 630 AM CDT WED AUG 13 2014
A few sites have been dealing with some morning fog, but it should
burn off within the next few hours. With high pressure overhead,
winds should be light and variable today. Expecting some cu
development today with the most coverage in the KEVV/KOWB areas
with an incoming weak frontal boundary from the northeast. Could
see some fog development on Friday morning as well.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
638 AM EDT THU AUG 14 2014
.SYNOPSIS...
LOW PRESSURE WILL LIFT ACROSS THE REGION TODAY BRINGING SOME HEAVY
RAINFALL WITH IT TO THE REGION. THE LOW IS EXPECTED TO WEAKEN AS
IT LIFTS NORTH OF THE MAINE BORDER TONIGHT WHILE THE UPPER LOW
REMAINS PARKED OVER QUEBEC INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...LATEST SURFACE ANALYSIS SHOWED LOW PRES LIFTING UP
ACROSS THE MID COAST W/THE OCCLUDED FRONT MOVING N. LATEST RADAR
IMAGERY SHOWED THE HEAVIES RAIN HAS NOW SHIFTED N AND E THE BACK
EDGE OF THE RAIN SHIELD NOW ACROSS PISCATAQUIS AND PENOBSCOT
COUNTIES. THE LATEST RUN OF THE HRRR 3KM MODEL HAD THIS HANDLED
WELL AND THEREFORE DECIDED TO MOVE THE HIGHEST RAINFALL CHANCES UP
ACROSS THE NORTHERN AND EASTERN SECTIONS. ISOLATED TSTMS POSSIBLE
INTO THE AFTERNOON W/SOME GUSTY WINDS AS EVIDENT OF THE LATEST
NAM/GFS SOUNDINGS.
PREVIOUS DISCUSSION...
HEAVY RAIN/FLASH FLOODING AND TSTMS THE BIG CHALLENGE FOR THIS
TERM.
06Z MESO ANALYSIS SHOWED AN OCCLUDED FRONT LIFTING N W/LOW PRES
DEVELOPING ON THE FRONT JUST E OF PWM. RADAR IMAGERY SHOWED A
LARGE SWATH OF RAIN LIFTING NORTH ACROSS THE CWA W/SOME VERY HEAVY
RAINFALL ACROSS THE CENTRAL HIGHLANDS AND WESTERN MOUNTAINS.
ALREADY HAD 2+ INCHES IN THE LAST 8 HRS ACROSS SOUTHERN
PISCATAQUIS COUNTY W/A STRONG INFLOW FROM SSE AND A THETA E RIDGE
RESIDING ACROSS THE REGION AIDING IN THE HEAVY RAINFALL. HEAVY
RAIN AXIS WILL SHIFT N TODAY ACROSS N AND NW AREAS W/GOOD LLVL
CONVERGENCE IN PLACE AND A STRONG LLVL JET OF 40+ KTS OVERHEAD.
A FLASH FLOOD WATCH REMAINS IN PLACE FOR NORTHERN SOMERSET AND
ALL OF PISCATAQUIS COUNTY THROUGH 12 PM AS SOME FLASH FLOODING IS
POSSIBLE GIVEN THE SSE WIND AND EMBEDDED TSTMS. THE NAM AND GFS
SOUNDINGS SUPPORT SOME ELEVATED CONVECTION INTO THE AFTERNOON
ACROSS MUCH OF THE CWA W/THE EXCEPTION OF THE COAST. 0-6KM SHEAR
OF 35+M KTS AND SOME DIRECTIONAL SHEAR COULD AID IN SOME STRONG
WIND GUSTS MIXING DOWN IN TSTMS ALONG W/THE RAIN. DECIDED TO ADD
THE GUSY WINDS IN THE FORECAST TODAY BASED ON THIS ASSESSMENT.
STEADY RAIN WILL BE SITUTAED ACROSS NORTHERN AREAS LATE THIS
AFTERNOON WHILE THE CENTRAL AND DOWNEAST AREAS WILL SEE A
TRANSITION TO SHOWERS AS A WSW WIND TAKES OVER AND FORCING
WEAKENS. DRYING ABOVE 700MBS IS NOTED BY BOTH THE NAM AND GFS
SOUNDINGS AS WELL. AFTERNOON TEMPERATURES WILL NOT RECOVER MUCH
HOWEVER, AS RAIN AND CLOUDS WILL KEEP AFTERNOON READINGS MUCH
BELOW NORMAL. WE ARE TALKING MID 60S FOR THE NORTHERN 1/2 WHILE
UPPER 60S TO AROUND 70 WILL BE THE GOING RATE FOR THE CENTRAL AND
DOWNEAST AREAS.
RAIN IS EXPECTED TO WIND DOWN THIS EVENING ACROSS THE NORTH AS THE
FRONT LIFTS N OF THE MAINE BORDER AS THE SFC LOW WEAKENS. DECIDED
TO DROP BACK THE POPS TO CHANCE(40%) ACROSS THE NORTHERN 3RD BY
MIDNIGHT WHILE CENTRAL AND DOWNEAST AREAS WILL BEGIN TO DRY OUT.
WINDS WILL DROP OFF AS WELL W/SOME PARTIAL CLEARING TOWARD EARLY
MORNING ESPECIALLY FOR THE CENTRAL AND DOWNEAST AREAS. THIS WILL
ALLOW FOR FOG FORMATION AND DECIDED TO CARRY FOG FOR OVERNIGHT
INTO EARLY FRIDAY MORNING.
&&
.SHORT TERM /FRIDAY/...
A COLD CORE LOW WILL REMAIN OVER SOUTHERN QUEBEC THROUGH THE NEAR
TERM PERIOD OF THE FORECAST. THE LOW WILL SLOWLY FILL AND DRIFT TO
THE NORTHEAST INTO NORTH CENTRAL QUEBEC BY THE END OF THE PERIOD.
A NEW FRONTAL SYSTEM WILL PUSH INTO SRN MAINE TOWARDS THE END OF
THE PERIOD. SCATTERED SHOWERS WILL PERSIST ACROSS MAINLY THE NORTH
AND CENTRAL PORTIONS OF THE CWA THROUGH THE PERIOD.
LOADED A BLEND OF NAM/GFS/GEM/ECMWF THROUGH THE PERIOD FOR ALL
ELEMENTS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AT THE START OF THE PERIOD A COLD CORE LOW OVER NORTH CENTRAL
QUEBEC WILL CONTINUE TO FILL AS IT DRIFT EAST. A TROUGH OF LOWER
WILL EXTEND ALONG THE SW COAST WEST ACROSS THE ERN GREAT LAKES
REGION. THERE WILL BE LOWS ALONG THE TROUGH. THE ECMWF CENTERS A
LOW ALONG THE SW COAST...WITH A SECOND LOW OVER LAKE HURON. THE
GEM AND NAM HAVE A LOW OVER VERMONT. THE GFS DOES NOT INDICATE A
SPECIFIC LOW. THE TROUGH WILL SLOWLY PUSH SOUTH INTO THE CENTRAL
GULF OF MAINE BY SUN EVNG. THE GFS/ECMWF/GEM ALL SHOW THE FILLING
COLD CORE LOW MOVING SE ACROSS MAINE/NEW BRUNSWICK DURING THE DAY
MONDAY...THE ENERGY BEING COLLECTED BY A NEW DYNAMIC LOW MOVING
INTO THE GULF OF ST LAWRENCE...WITH HIGHER PRESSURE RIDGING INTO
THE CWA BEHIND THE DEPARTING LOW.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: MVFR ACROSS THE NORTHERN TERMINALS THIS MORNING
DROPPING TO IFR W/HEAVY RAIN. KBGR AND KBHB WILL SEE IFR W/PERIODS
OF MVFR THIS MORNING. CONDITION FOR THESE TERMINALS SHOULD RECOVER
TO MVFR BY THIS AFTERNOON W/VFR BY EARLY TONIGHT. ACROSS THE
NORTHERN TERMINALS FROM KHUL N THROUGH KFVE, IFR GOING TO MVFR
LOOKS TO BE IN ORDER. SOME LLWS IS POSSIBLE TODAY ESPECIALLY
IN ANY TSTMS.
SHORT TERM: MAINLY VFR CONDITIONS ACROSS NRN AND CNTRL ME THROUGH THE PERIOD.
OCNL PERIODS WERE CIGS WILL FALL MVFR IN SHWRS. VFR CONDITIONS FOR
BGR AND BHB THROUGH EARLY SUN MRNG. VSBY AND CIGS WILL BEGIN
FALLING LATE SAT TO EARLY SUN MRNG FOR DOWNEAST AND INTERIOR
DOWNEAST AS THE NEXT FRONTAL SYSTEM APPROACHES FROM THE SW. MVFR
CONDITIONS ACROSS NRN AND CNTRL ME SUNDAY BCMG VFR EARLY MONDAY.
OCNL PERIODS WERE CIGS WILL FALL IFR IN SHWRS. IFR TO LMVFR
CONDITIONS FOR BGR AND BHB THROUGH SUNDAY AND MONDAY...VSBY AND
CIGS WILL BEGIN IMPROVING EARLY TUES MRNG FOR DOWNEAST AND
INTERIOR DOWNEAST AS THE HIGH BUILDS IN FROM THE NW.
&&
.MARINE...
NEAR TERM: SCA CONDITIONS ARE OCCURRING ATTM PER THE LATEST BUOYS.
DECIDED TO USE THE GFSSWAN GUIDANCE FOR WINDS/SEAS AS IT IS
HANDLING THINGS QUITE WELL PER THE LATEST CONDITIONS. GUSTS ARE
25+ KTS. INCREASED THE SUSTAINED AND THE GUSTS BY 5 KTS BASED ON
THESE TRENDS. DECIDED TO STAY W/THE SCA THROUGH THE AFTERNOON.
WINDS LOOK LIKE THEY WILL COME DOWN AS THE LLVL JET MOVES NORTH
OF THE WATERS. SEAS WILL MOST LIKELY STAY UP NEAR 6 FT A WHILE
LONGER AS HEIGHTS ATTM ARE RUNNING 8-10 FT. THE DAYCREW MAY BE
ABLE TO TRANSITION THE HEADLINE FOR MAINLY SEAS LATER TODAY.
CONDITIONS DO LOOK LIKE THEY WILL COME DOWN BELOW SCA LEVELS LATER
TONIGHT AS WINDS GO OFFSHORE.
SHORT TERM: WINDS AND SEAS WILL BE BELOW SCA THROUGH THE PERIOD.
&&
.HYDROLOGY...
AS STATED ABOVE, THE FLASH FLOOD WATCH IS IN PLACE W/POTENTIAL FOR
SOME FLASH FLOODING. THE AREAS W/THE GREATEST THREAT WILL BE
PISCATAQUIS COUNTY AS HEAVY RAIN HAS BEEN TRAINING ACROSS THIS
REGION W/EMBEDDED TSTMS. FLASH FLOOD GUIDANCE IS NEAR 3 INCHES IN 3
HOURS AND SOME AREAS IN PISCATAQUIS COUNTY WERE CLOSE TO THIS
GUIDANCE EARLY THIS MORNING. HEAVY RAIN AXIS WILL SHIFT NORTH OF
THIS REGION LATER THIS MORNING INTO THE AFTERNOON. AREAS FURTHER
TO THE N AND E, SHOULD BE ABLE TO HANDLE THE HEAVY RAINFALL.
STREAMS AND RIVERS WERE LOW BUT ARE AND WILL CONTINUE TO SEE RISES
TODAY, BUT REMAIN WELL WITHIN THEIR BANKS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...FLASH FLOOD WATCH UNTIL NOON EDT TODAY FOR MEZ003-004-010-031.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR
ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...NORTON
LONG TERM...NORTON
AVIATION...HEWITT/NORTON
MARINE...HEWITT/NORTON
HYDROLOGY...HEWITT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1127 AM EDT THU AUG 14 2014
.SYNOPSIS...
AFTER A FEW SHOWERS OR SPRINKLES TODAY...DRY AND COOL CONDITIONS
CAN BE EXPECTED INTO SATURDAY. THE NEXT WEATHER SYSTEM WILL AFFECT
US SUNDAY AS AN UPPER DISTURBANCE PASSES.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOWER MID LEVEL HEIGHTS CONTINUE TO ENCOMPASS THE AREA WHILE
TRIGGER TEMPERATURES HAVE BEEN ATTAINED OVER MUCH OF THE REGION
ALLOWING CU TO FORM. REGIONAL RADAR MOSAIC AS OF 15Z REMAINS QUIET
AND BASED ON LATEST HRRR SCALED ISOLD SHOWER MENTION BACK TO THE
FAR NORTHERN SECTIONS /N OF I-80/. TEMPS ON TRACK WITH READINGS
NEARLY 10 DEGREES BELOW NORMAL.
HIGH PRESSURE BUILDS INTO THE AREA TONIGHT ALLOWING FOR A
COOL NIGHT. THE ONLY FLY IN THE OINTMENT WOULD BE A POCKET OF LLVL
RH ILLUSTRATED BY NAM MODEL THAT DROPS S FORM LAKE ERIE INTO THE
MTNS DURING THE OVERNIGHT HOURS. FOR NOW...INCREASED SKY COVER FOR
PA COUNTIES...BUT THIS MAY NEED TO BE ADJUSTED AFTER FULL SUITE
OF 12Z MODELS ARRIVE.
RECORD LOWS FOR PIT/MGW/ZZV APPEAR SAFE TONIGHT WITH READINGS
IN THE UPPER 30S AND LOWER 40S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
DRY AND A SLOW WARMING TREND FRIDAY AND SATURDAY AS HIGH PRESSURE
SLIDES EAST ACROSS THE REGION. NEXT UPPER LEVEL TROUGH APPROACHES
LATER SATURDAY NIGHT INTO SUNDAY WITH INCREASING LOW LEVEL
MOISTURE AND CHANCE POPS FOR SHOWERS AND THUNDERSTORMS.
TEMPERATURES WILL WARM TO NEAR SEASONAL AVERAGE BY SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
GENL ZONAL FLOW IS PROGGED TO SET UP ACRS THE RGN THRU THE PD. MDLS
CONT TRENDING TWD SVRL CROSSING SHRTWVS EMBEDDED IN THE FLOW...AND
AS A RESULT INCLUDED CHC POPS FOR SHWRS/TSTMS THRU MUCH OF THE PD.
DETAILS WL DEPEND ON SPECIFIC SFC BNDRY PLACEMENT AND TIMING OF
SHRTWVS. TEMPS SHOULD AVG NR SEASONAL LVLS.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR. CU WILL RAPIDLY DEVELOP THIS MORNING WITH BKN CIGS AT FKL
AND DUJ...OTHERWISE SCT CLOUD COVER. ANY CU WILL DISSIPATE WITH
LOSS OF HEATING OWING TO A SKC CONDITIONS TNGT.
OUTLOOK.../FRIDAY THROUGH MONDAY/...
RESTRICTIONS ARE POSSIBLE SUNDAY IN SHOWERS AND THUNDERSTORMS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
NEAR TERM...98
AVIATION...98
AREA FORECAST DISCUSSION
NWS BILLINGS MT
910 AM MDT THU AUG 14 2014
.UPDATE...
FORECAST IS ON TRACK FOR MUCH OF THE CWA TO RECEIVE SOME RAIN
TODAY. CURRENTLY...SHOWERS EXIST ACROSS OUR WEST AND SOUTH CENTRAL
PARTS...WITH MOVEMENT FROM SOUTH TO NORTH. MAIN MID LEVEL LOW IS
STILL IN CENTRAL WYOMING SO SHOWERS WILL CONTINUE TO FEED IN FROM
THE SOUTH FOR THE NEXT SEVERAL HOURS. HAVE ADJUSTED MORNING POPS
TO LIKELY IN PLACES BASED ON CURRENT RADAR. FOCUS WILLE
EVENTUALLY SHIFT TO OUR EAST THIS AFTERNOON AND EVENING AS MID
LEVEL CIRCULATION LIFTS INTO SOUTHEAST MT. PWATS ARE QUITE HIGH
AND COULD BRING A RISK OF HEAVY RAIN IF IT WERE NOT FOR THE CLOUDY
SKIES AND EARLY ONSET OF SHOWERS. THE EXCEPTION COULD BE IN OUR NE
WHERE SUNNY SKIES IN THE MORNING AND TEMPS TO THE LOW 90S WILL
ALLOW FOR SOME CAPE TO BUILD UP. MODELS CERTAINLY PAINT HIGHEST
QPF IN AN AREA FROM MILES CITY TO BAKER THIS EVENING. WITH THIS IN
MIND HAVE RAISED EVENING POPS TO LIKELY IN THIS AREA. SHEAR WILL
BE RATHER LOW TODAY SO DO NOT SEE A SIGNIFICANT SEVERE RISK...BUT
HEAVY RAIN AND SMALL HAIL A DEFINITE POSSIBILITY NEAR MILES CITY
AND BAKER BY LATE AFTERNOON AND EVENING. SSEO AND HRRR ALSO
SUGGEST GREATER POTENTIAL FOR HIGHER REFLECTIVITIES IN THIS AREA
AS WELL.
OVERALL...TODAY WILL BE BENEFICIAL REGARDING FIRE WEATHER AS MOST
OF THE REGION WILL SEE SHOWERS AND HIGHER HUMIDITY WITHOUT THE
RISK OF FREQUENT LIGHTNING.
JKL
&&
.SHORT TERM...VALID FOR TDY AND FRI...
A WET DAY IS AHEAD FOR MUCH OF SOUTHEASTERN MONTANA AND NORTHERN
WYOMING...
MODELS IN GOOD AGREEMENT IN BRINGING SHORT WAVE ENERGY INTO
NORTHERN WY AND SOUTH CENTRAL MT BY THURSDAY AFTERNOON. MONSOONAL
MOISTURE FETCH DEPICTED ON WATER VAPOR CONTINUES TO RIDE THE
WESTERN SIDE OF THE UPPER LEVEL RIDGE INTO THE NORTHERN ROCKIES.
NAEFS PW ANOMALIES ARE SHOWING STANDARD DEVIATION VALUES GREATER
THAN 2 FOR MUCH OF THE BYZ CWA. IN ADDITION...LATEST HRRR GUIDANCE
DEPICTING WIDESPREAD SHOWER ACTIVITY IN A LINE FROM WHEATLAND
COUNTY DOWN TO SOUTHERN ROSEBUD COUNTY BY MID MORNING.
FURTHER...WPC 6 HOUR PQPF GUIDANCE SHOWS NICE AREA OF >80 PERCENT
PROBABILITY OF MEASURABLE PRECIPITATION OVER MUCH OF THE CWA BY
00 UTC FRIDAY. SO...WITH ALL OF THAT...DECIDED TO CONTINUE WITH
TREND OF RAISING POPS ON TOP OF WHAT PREVIOUS FORECAST ALREADY HAD
ACROSS THE ENTIRE CWA. NOT EXPECTING PRECIPITATION TODAY TO BE
SEVERE IN NATURE...BUT A FEW OF THESE ISOLATED STORMS COULD
PRODUCE HEAVY RAIN AT TIMES. STORMS THAT HAVE DEVELOPED THE PAST
DAY OR SO HAVE SHOWN NICE KDP RETURNS ON RADAR. THIS BEARS
WATCHING AS STORMS THAT FORM OVER BURN SCAR AREAS MAY BE
SUSCEPTIBLE TO DEBRIS FLOWS AND SUCH.
TEMPERATURES SHOULD BE COOLER TODAY...WITH CLOUD COVER AND
PRECIPITATION IN THE AREA...WITH HIGHS IN THE UPPER 80S TO LOW 90S
ACROSS THE PLAINS.
FOR FRIDAY...THE LOW THAT HAS BEEN STALLED OVER THE PAC NW FOR
THE LAST DAY OR SO WILL BEGIN TO MOVE EASTWARD. EVEN THOUGH BEST
FORCING WILL BE TO THE WEST OF THE BYZ CWA...THERE WILL BE ENOUGH
LEFT OVER MONSOONAL MOISTURE TO GENERATE SOME SHOWERS ACROSS THE
REGION. SINGER
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MODELS WERE IN PRETTY GOOD AGREEMENT THROUGH THE EXTENDED
PACKAGE. THE NORTHWEST UPPER LOW CURRENTLY OVER NORTH CENTRAL
OREGON IS PROGGED TO SLIDE ACROSS NORTHERN MONTANA THIS WEEKEND.
DEEPEST INSTABILITY WILL BE OVER SOUTHEAST MONTANA ON SATURDAY AS
THESE LOCATIONS WILL BE EAST OF A SURFACE TROUGH. THE SURFACE
TROUGH WILL SLIDE EAST ON SUNDAY FOR A LESSENING CHANCE OF
CONVECTION. THE FLOW DRIES OUT SOME FOR MONDAY AND TUESDAY AS IT
BACKS TO THE NORTHWEST. HEIGHTS WILL FALL FOR WEDNESDAY AND
THURSDAY AS AN UPPER TROUGH DROPS SOUTHEAST FROM SOUTHWEST CANADA.
THIS WILL INCREASE THE CHANCE OF SHOWERS AND THUNDERSTORMS. TWH
&&
.AVIATION...
SHOWERS ARE SPREADING NORTH FROM WYOMING THIS MORNING...AND HAVE
STARTED TO IMPACT KSHR/KLVM/KBIL. THE SHOWERS WILL CONTINUE TO
SPREAD NORTH AND EAST...IMPACTING KMLS/KBHK BY MID AFTERNOON.
LOCALIZED MVFR/IFR CONDITIONS CON BE EXPECTED IN HEAVIER RAIN
SHOWERS. THE BEST POTENTIAL FOR THUNDERSTORMS WILL OCCUR OVER THE
EAST AND SOUTHEAST ROUTES THIS AFTERNOON/EVENING. PRECIP WILL BE
HEAVIER IN THUNDERSTORMS...RESULTING IN LOCALIZED IFR/LIFR FLIGHT
CONDITIONS. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 083 064/089 062/088 061/088 061/087 061/091 061/087
6/T 43/T 32/T 22/T 21/B 11/U 12/T
LVM 086 055/088 053/087 052/088 052/086 053/088 053/086
6/T 54/T 42/T 22/T 22/T 21/B 12/T
HDN 085 061/090 059/090 058/090 058/089 058/093 058/090
6/T 43/T 32/T 22/T 21/B 11/B 12/T
MLS 092 065/087 063/090 061/089 061/088 061/091 062/089
6/T 64/T 44/T 42/T 21/B 11/B 12/T
4BQ 088 065/087 062/089 060/089 059/088 059/090 060/090
6/T 64/T 43/T 33/T 31/B 11/B 12/T
BHK 093 062/085 060/087 056/086 056/085 055/087 057/087
5/T 64/T 45/T 43/T 31/B 11/B 12/T
SHR 082 058/089 056/089 054/088 054/086 054/088 055/087
6/T 43/T 32/T 22/T 21/B 11/U 12/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1001 AM CDT THU AUG 14 2014
.UPDATE...
ISSUED AT 958 AM CDT THU AUG 14 2014
UPDATED FORECAST TO INCREASE CLOUD COVER A BIT BASED ON RECENT
SATELLITE TRENDS. ALSO CONSIDERED A SLIGHT CHANCE OF SHOWERS TO
THE FAR NORTHERN FORECAST AREA AS A CLUSTER OF CONVECTION
CONTINUES TO MOVE THROUGH EASTERN SOUTH DAKOTA. RADAR TRENDS
SUGGEST PRECIP IS HAVING A HARD TIME PUSHING SOUTHEAST. LATEST
RUNS OF THE RAP MODEL ALSO KEEP RAIN OUT OF THE FORECAST AREA AND
THIS SEEMS REASONABLE. WILL CONTINUE TO MONITOR TO SEE IF ANYTHING
MIGHT DEVELOP THERE THROUGH PEAK HEATING...BASED ON 12Z NAM.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 316 AM CDT THU AUG 14 2014
MAIN FORECAST CONCERN IS TIMING/CHANCES OF PCPN THROUGH THE WEEKEND.
UPPER RIDGE AXIS CONTINUES TO MOVE EAST...EXTENDING FROM WESTERN
TEXAS NORTHWARD INTO WESTERN NEB AND THE WESTERN DAKOTAS.
SATELLITE IMAGERY SHOWS UPPER SHORTWAVE TROUGH MOVING NORTHEAST
NEAR THE FOUR CORNERS REGION AND THIS WILL CONTINUE TO RIDE UP THE
THE RIDGE AND INTO WESTERN SD/NEB BY 00Z TONIGHT. AT THE
SURFACE...A LARGE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE
MIDWEST WILL CONTINUE TO SLOWLY MOVE EAST BRINGING PREVAILING
SOUTHEASTERLY SFC FLOW OVER MUCH OF THE CENTRAL PLAINS TODAY. IN
ADDITION...AN ELONGATED REGION OF LEE SIDE LOW PRESSURE EXTENDS
ACROSS THE HIGH PLAINS AHEAD OF THE APPROACHING SHORTWAVE TROUGH.
AS THE UPPER SHORTWAVE TOPS THE RIDGE...THE LEE SIDE LOW WILL ALSO
ADVANCE EAST...SLIDING INTO CENTRAL NEB BY FRIDAY MORNING.
INCREASING ISENTROPIC UPGLIDE AHEAD OF THIS COULD PRODUCE A FEW
SHOWERS AND ISOLATED THUNDERSTORMS...ESPECIALLY WITH A
STRENGTHENING SOUTHWESTERLY LOW LEVEL JET. WE MAY JUST SEE AN
INCREASE OF MID CLOUDS/ACCAS. SPOTTY SHOWERS LOOK MORE PROBABLE
BY FRIDAY AFTERNOON AND EVENING IN ADVANCE OF THE APPROACHING
SHORTWAVE. ONCE THE WAVE IS OVERHEAD IN EASTERN NEBRASKA...IT WILL
DEEPEN AND CLOSE OFF AS IT MOVES INTO NORTHERN MISSOURI. PLACEMENT
AND TIMING OF THIS FEATURE HAS BECOME MORE CONSISTENT IN VARIOUS
MODEL SOLUTIONS SO FORECAST CONFIDENCE IS INCREASING. BY 12Z
SATURDAY...THE UPPER WAVE IS PROGGED TO MOVE OVER NORTHEAST
NEBRASKA WITH THE ASSOCIATED SFC LOW CENTERED SOMEWHERE OVER
EASTERN NEBRASKA. HEAVIER PCPN IS LIKELY ALONG THE WARM FRONT
WHICH SHOULD EXTEND INTO WESTERN IOWA SO HAVE INCREASED POPS IN
SERN NEB AND SWRN IA. AS THE SYSTEM MOVES INTO NORTHERN MISSOURI
SATURDAY AFTERNOON...WE SHOULD SEE LINGERING SHOWERS ON THE
BACKSIDE OF THE SYSTEM ALONG WITH CLOUD COVER AND COOLER TEMPS.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 AM CDT THU AUG 14 2014
THERE REMAINS A CHANCE OF PCPN IN NEARLY EVERY FORECAST PERIOD IN
THE EXTENDED AS ADDITIONAL PIECES OF SHORTWAVE ENERGY MOVE ACROSS
THE FLATTENED UPPER LEVEL FLOW. TIMING OF THESE FEATURES IS PRETTY
TOUGH THIS FAR OUT...BUT CANNOT RULE OUT ANY ONE GIVEN PERIOD.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 605 AM CDT THU AUG 14 2014
A LITTLE PATCHY FOG IS POSSIBLE EARLY THIS MORNING...OTHERWISE
GENERALLY LOOK FOR VFR CONDITIONS THROUGH THE PERIOD. WE COULD
SEE SOME ISOLD TSRA AFTER 06Z TONIGHT. MVFR CONDITIONS WOULD BE
PSBL IF PCPN DEVELOPS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS ELKO NV
356 AM PDT THU AUG 14 2014
.SYNOPSIS...THUNDERSTORMS WILL IMPACT NORTHEASTERN NEVADA INTO
THIS EVENING. DRIER AND MORE STABLE AIR BUILDING IN FROM THE
SOUTHWEST WILL RESULT IN STORM ACTIVITY ENDING ACROSS MOST OF THE
REGION TONIGHT. WARM AND DRY FRIDAY ON INTO NEXT WEEK.
&&
.SHORT TERM...TODAY THROUGH FRIDAY. NAM/EURO/GFS ALL AGREE VERY
WELL ON MAJOR AND MINOR FEATURES THROUGH THE SHORT TERM PERIOD.
UPPER LOW OVER PACIFIC NORTHWEST IS THE DRIVING FORCE BEHIND THE
CHANGE IN THE WEATHER COMING TO THE GREAT BASIN. DRY SOUTHWEST
FLOW WILL TAKE OVER SLOWLY STARTING TODAY AND CONTINUING INTO LATE
FRIDAY. EXITING SHORTWAVE WILL CAUSE LINGERING SHOWERS OVER
NORTHERN NEVADA WITH ISOLATED THUNDER OVER NORTHEAST NEVADA AND
JUST STRAY THUNDERSTORMS OVER EASTERN NEVADA TODAY AND THIS
EVENING. HRRR SHOWS AMPLE MOISTURE OVER EASTERN SECTIONS AND
THEREFORE SOME RISK OF LOCAL FLOODING STILL EXISTS THROUGH THE END
OF STORMS TONIGHT. HAIL MAY ALSO BE AN ISSUE...WITH LIMITED RISK
OF DAMAGING DOWNBURST WINDS. FOR LATE THURSDAY NIGHT INTO
FRIDAY...MODELS AGREE ON STORM FREE FOR THE ENTIRE FORECAST
AREA...THEREFORE POPS VERY LOW TO ZERO.
WINDS PICKS UP A BIT TODAY IN WHITE PINE COUNTY AND NORTHEAST NYE
COUNTY. GUSTING TO NEAR 30 MPH AT TIMES IN THE AFTERNOON TODAY. BB
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY. GFS AND ECMWF IN
CLOSER AGREEMENT TONIGHT THROUGH THE LONG TERM. ON FRIDAY NIGHT A
TROUGH WILL BE LOCATED TO OUR NORTH WITH A CLOSED LOW SETTING UP
SHOP OVER THE EASTERN PACIFIC WEST OF CALIFORNIA. THIS WILL PLACE
A DRY WEST TO SOUTHWEST FLOW OVER OUR REGION. A LITTLE VORT
MAX/SHORTWAVE IS PROGGED TO MOVE ACROSS NORTHWEST NEVADA LATER
SATURDAY...AND ITS POSSIBLE THIS SYSTEM TRIGGERS A STRAY
THUNDERSTORM IN HUMBOLDT COUNTY...BUT OTHERWISE SATURDAY SHOULD BE
DRY. AFTER THAT...THE REGION WILL BE DOMINATED BY A DRY RIDGE
WEDGED IN BETWEEN THE CLOSED LOW TO THE WEST OF CALIFORNIA AND
FAST WESTERLY FLOW TO THE NORTH OVER THE FAR NORTHWESTERN U.S. AND
SOUTHERN CANADA. THERE COULD STILL BE AN ISOLATED DRY THUNDERSTORM
ONE OR MORE DAYS ALONG THE NORTHERN OR EASTERN PARTS OF THE CWA AS
MOISTURE LEVELS IN THESE AREAS WILL BE NEAR 0.5 INCH...BUT
GENERALLY THE ODDS ARE BELOW 15 PERCENT. TEMPERATURES WILL BE WARM
AND THINK GUIDANCE HAS BEEN RUNNING COOL SO GENERALLY BUMPED
NUMBERS UP FROM GUIDANCE. RCM
&&
.AVIATION...AMPLE LOW LEVEL MOISTURE FROM RAIN OVER THE PAST FEW
DAYS MAY CONTRIBUTE TO FOG DEVELOPMENT OVER THE NEXT FEW HOURS AT
KEKO AND KELY. CHANCE APPEARS LOW BUT NOT ZERO SO HAVE INCLUDED
VCFG IN TAF. OTHERWISE...DRIER AIR MOVING IN WILL PREVENT STORM
DEVELOPMENT TODAY WITH BREEZY BUT NOT WINDY AFTERNOON CONDITIONS
AND SOME CUMULUS DEVELOPING AS LOW LEVEL MOISTURE MIXES OUT. RCM
&&
.FIRE WEATHER...DRY SOUTHWEST FLOW WILL BEGIN TO PUSH STORMS EAST
TODAY. ISOLATED THUNDERSTORMS OVER ZONES 469/470 AND VERY SPOTTY
OVER 455 TODAY AND THIS EVENING. STARTING TONIGHT...DRIER AIR
MOVES IN AND FRIDAY AND THE WEEKEND LOOK DRY. THIS AFTERNOON OVER
455...WINDS PICK UP TO NEAR RFW CRITERIA BUT RH VALUES ARE WELL
HIGH ENOUGH TO AVOID RFW. OVER PORTIONS OF ZONES 467/468 RH VALUES
ARE LOW DOUBLE DIGITS TODAY...BUT WINDS ARE WEAK ENOUGH TO AVOID A
RFW THERE TOO. INCREASING DRYNESS FROM THE SOUTH OVER THE
WEEKEND...BUT WINDS TEND TO SOFTEN. BB
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
98/93/93/98
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1035 AM EDT THU AUG 14 2014
.SYNOPSIS...A DRY CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE MID-
ATLANTIC AND CAROLINAS THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 1030 AM THURSDAY...
TODAY/TONIGHT OVERVIEW: CYCLONIC FLOW ALOFT WILL DOMINATE THE UPPER
LEVEL PATTERN ACROSS CENTRAL NC THROUGH TONIGHT...ON THE SOUTHERN
PERIPHERY OF AN UNSEASONABLY DEEP UPPER LEVEL LOW STALLED IN VICINITY
OF THE LOWER GREAT LAKES/SOUTHERN QUEBEC. 14Z WV IMAGERY AND RAP DATA
INDICATED A POTENT SHORTWAVE UPSTREAM OVER IL/IN THIS MORNING. THIS
FEATURE IS PROGGED TO TRACK SE THROUGH KY EARLY THIS AFTERNOON...THEN
EASTWARD THROUGH SOUTHERN WV INTO SOUTHERN VA BY 00Z. DPVA ASSOC/W THE
WAVE WILL RESULT IN WEAK HEIGHT/SLP FALLS OVER THE REGION...WITH LOW-
LEVEL FLOW GRADUALLY VEERING FROM N/NE THIS MORNING TO SW/WSW THIS
AFTERNOON. THE AIRMASS OVER CENTRAL NC THIS MORNING IS UNSEASONABLY DRY
(PWAT 0.71" PER 12Z GSO RAOB)...A RESULT OF MID-LEVEL SUBSIDENCE AND
LOW-LEVEL COLD ADVECTION IN THE WAKE OF THE COLD FRONTAL PASSAGE EARLY
YESTERDAY. SFC DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S AT
14Z...AND ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOWER/MID 50S VIA
THIS AFTERNOON IN ASSOC/W DIURNAL HEATING/MIXING.
TODAY/TONIGHT FORECAST: DIURNAL HEATING WILL BE INSUFFICIENT TO
DESTABILIZE THE ATMOSPHERE OVER CENTRAL NC THIS AFT/EVE GIVEN A VERY
DRY BOUNDARY LAYER AND LITTLE IF ANY MOISTURE ADVECTION/RECOVERY...EVEN
AS FLOW VEERS TO THE SW/WSW. AS A RESULT...THE POTENT SHORTWAVE ENERGY
TRACKING THROUGH SOUTHERN WV/VA LATE THIS AFT/EVE SHOULD YIELD LITTLE
MORE THAN SCATTERED UPPER LEVEL CLOUD COVER. EXPECT HIGHS BELOW NORMAL
IN THE LOWER 80S NW TO MID/UPPER 80S SOUTH AND SE OF THE TRIANGLE. LOWS
TONIGHT SIMILAR TO LAST NIGHT ALBEIT A LITTLE WARMER DUE TO AIRMASS
MODIFICATION TODAY...IN THE LOWER 60S EARLY FRI MORNING. -VINCENT
FOR FRI/FRI NIGHT: THE AFOREMENTIONED E-W ORIENTED SECONDARY FRONT
LOOKS LIKELY TO STALL OUT JUST NORTH OF THE NC/VA BORDER FRI AS A
WEAK TROUGH FORMS OVER THE PIEDMONT. PW IS PREDICTED TO STEADILY
INCREASE LATE IN THE DAY THROUGH EVENING TO AT OR ABOVE 1.5" FROM
THE TRIANGLE EAST AND SE... ALONG AND AHEAD OF THE WEAK PIEDMONT
TROUGH. THE NAM/GFS BOTH SHOW WEAK LOW PRESSURE FORMING FRI EVENING
OVER THE NE PIEDMONT... AND THIS SUBTLE MASS CONVERGENCE JUST SOUTH
OF THE BACKDOOR FRONT COMBINED WITH INCREASING MOISTURE AND
IMPROVING (BUT STILL MODEST) INSTABILITY (MLCAPE RISING TO 500-1500
J/KG) IN THIS AREA MAY SUPPORT ISOLATED SHOWERS AND PERHAPS A STORM
OVER THE NORTHEAST QUARTER OF THE CWA. LOTS OF UNCERTAINTY HOWEVER
WITH A LACK OF MID-UPPER SUPPORT FOR POPS... SO WILL RAISE POPS TO
10-14% FOR NOW... AND CONTINUE TO MONITOR FOR POSSIBLE INCLUSION OF
A SLIGHT CHANCE OF SHOWERS/STORMS IN LATER FORECASTS. IN ANY CASE...
DO EXPECT AN INCREASE IN CLOUDS TO PARTLY CLOUDY LATE FRI THROUGH
FRI NIGHT... ESPECIALLY IN THE NE CWA. SHOULD SEE NEAR NORMAL HIGHS
OF 86-90... WITH LOWS INCHING BACK UP TOWARD NORMAL.. 63-68. -GIH
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 240 AM THURSDAY...
CENTRAL NC IS IN FOR A WARM AND DRY WEEKEND FOR A CHANGE AS A ZONAL
UPPER LEVEL PATTERN COINCIDES WITH RELATIVE HIGH PRESSURE AT THE
SURFACE ON THE BACK SIDE OF THE BERMUDA HIGH WHICH WILL USHER IN THE
RETURN FLOW RESPONSIBLE FOR THE WARMER TEMPERATURES. MODEL THICKNESS
VALUES SOAR AS HIGH AS THE 1420S ON THE MORE AGGRESSIVE GFS
SUGGESTING HIGHS IN THE LOWER 90S BUT SOME POSSIBLE SHORTWAVE
INDUCED CLOUDINESS COULD KEEPS TEMPERATURES DOWN A LITTLE AS
SUGGESTED BY ADJUSTED MOS GUIDANCE. WILL GO WITH UPPER 80S TO LOWER
90S NORTHWEST TO SOUTHEAST WITH SUNDAY BEING THE WARMER DAY OUT OF
THE TWO. LOWS IN THE MID 60S TO LOWER 70S. LIGHT WINDS OUT OF THE
SOUTH LESS THAN 5 KTS.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 240 AM THURSDAY...
THE PATTERN STARTS TO BECOME A LITTLE MORE ACTIVE ON MONDAY AS A
WEAK SURFACE LOW MOVES THROUGH THE OHIO VALLEY AND INTO THE MID
ATLANTIC STATES. THE GFS IS MORE AGGRESSIVE WITH THE DEVELOPMENT AND
THE VERTICAL EXTENT OF THE LOW...INFLUENCING THE DEEPENING OF A
SHORTWAVE TROUGH AT 500 MB. THIS IS NOT SEEN ON THE 12Z RUN OF THE
ECMWF UNTIL LATER IN THE PERIOD. THE UPSHOT IS THE SAME...WHICH WILL
BE DIURNALLY DRIVEN PRECIPIATION CHANCES EACH AFTERNOON MONDAY
THROUGH WEDNESDAY WITH SLIGHT CHANCES DURING THE LESS FAVORABLE
NOCTURNAL HOURS. INSTABILITY WILL BE MODEST...UP TO 1000 J/KG AND
BULK SHEAR WILL GENERALLY STAY BETWEEN 10-20 KTS SUGGESTIVE OF
NOTHING MORE THAN GARDEN VARIETY SUMMERTIME THUNDERSHOWERS. ALTHOUGH
THICKNESSES GO UP...AN EXPECTED INCREASE IN CLOUD COVER AND
PRECIPITATION COVERAGE WILL KEEP HIGHS GENERALLY IN THE LOWER 90S
EACH DAY WITH LOWS OVERNIGHT IN THE UPPER 60S TO LOW 70S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM THURSDAY...
HIGH CONFIDENCE IN FAVORABLE VFR CONDITIONS TODAY THROUGH TONIGHT.
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
WEST... RESULTING IN LIGHT SURFACE WINDS GENERALLY UNDER 8 KTS...
MAINLY FROM THE NW OR NORTH TODAY. ANY CLOUDS WILL BE MOST NUMEROUS
IN THE LATE AFTERNOON THROUGH TONIGHT WITH ANY BASES ABOVE 4000 FT
AGL. VERY LIGHT WINDS WILL BECOME MAINLY SOUTHWESTERLY TONIGHT AS A
WEAK SECONDARY BACKDOOR FRONT APPROACHES FROM THE NORTH LATE.
LOOKING BEYOND 12Z FRI MORNING... VFR CONDITIONS LIKELY TO DOMINATE
THROUGH AT LEAST SUNDAY NIGHT WITH DRY AIR IN PLACE. A POTENTIAL
STORM SYSTEM MAY APPROACH FROM THE WEST MONDAY... BRINGING A CHANCE
OF SUB-VFR CONDITIONS AND SHOWERS/STORMS. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT/HARTFIELD
SHORT TERM...ELLIS
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
940 AM EDT THU AUG 14 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL REINFORCE THE DRY AIRMASS ON THURSDAY...BUT
COULD BRING A FEW SHOWERS TO THE MOUNTAINS. HIGH PRESSURE WILL
BUILD IN FOR FRIDAY AND SATURDAY. NEXT FRONTAL SYSTEM LOOKS TO
IMPACT US EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM EDT THURSDAY...
MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES AND CLOUD COVER FOR
THIS MORNING INTO THIS AFTERNOON. HRRR AND RNK WRFARW CONTINUE TO
SHOW A FEW SHOWERS WITH THE WEAK COLD FRONT WHICH DROP SOUTHEAST
ACROSS THE REGION. WITH LATEST REGIONAL WRS-88D LOOP SUGGESTING
THAT CONVECTION TO OUR WEST IS DIMINISHING WILL HOLD TO JUST IN
THE WEST. HIGHS THIS AFTERNOON WILL RANGE FROM THE MID 60S IN THE
NORTHWEST TO THE LOWER 80S IN THE SOUTHEAST.
AS OF 710 AM EDT THURSDAY...
UPDATED FORECAST TO ACCOUNT FOR MORE CLOUDS ARRIVING TODAY FROM
THE NW PER IMPULSE NOW OVER NRN KY. THE HIGH-RES MODELS AS WELL AS
THE 06Z GFS/00Z ECMWF ALLOW FOR CLOUDS TO EXPAND EAST INTO THE
FOOTHILLS THIS AFTERNOON...AND BRING ISOLATED/WIDELY SCATTERED
SHOWERS TO THE MTNS OF WV/VA COUNTIES ADJACENT LATER THIS MORNING.
MAY SEE SOME SPRINKLES AS FAR EAST AS THE INTERSTATE 81 CORRIDOR
THIS AFTERNOON. OTHERWISE...NO CHANGES TO THE TEMPS FOR HIGHS.
PREVIOUS VALID DISCUSSION...
HIGHS TODAY WILL BE BELOW NORMAL...STILL THINK MORE SUNSHINE MOST
LOCATIONS...THOUGH POTENTIAL AGAIN FOR THE MTNS STAYING PARTLY
SUNNY- MOSTLY CLOUDY THRU THE DAY. EXPECT HIGHS TO RANGE FROM THE
LOWER TO MID 70S IN THE MOUNTAINS...NEW RIVER VALLEY...TO LOWER TO
MID 80S EAST OF THE BLUE RIDGE AND SRN SHENANDOAH VALLEY.
TONIGHT...ANY SHOWERS OVER THE HIGHER RIDGES OF SE WV WILL
DISSIPATE. STILL UPPER TROUGH CONTINUES TO LINGER OVER THE AREA
WITH ANOTHER SHORTWAVE ROUNDING THE BASE OF THE TROUGH THROUGH WV
LATE. THINK THE CLOUD COVER WILL BE SCATTERED...THOUGH NOT OUT OF
THE QUESTION TO SEE MORE CLOUDS INTO THE MTNS OF WV LATE. LOWS
WILL BE VARYING DEPENDING ON CLOUDS COVER BUT STILL LOOKING AT
COOLER TEMPS...BUT NOT LOOKING AT RECORD LOWS AT THIS
POINT...GIVEN THAT SOME CLOUD COVER MAY AFFECT TEMPS FALLING FAR.
UPPER 40S MTN VALLEYS TO MID TO UPPER 50S EAST OF THE BLUE RIDGE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 AM EDT THURSDAY...
OVERALL MAINLY A CONTINUED TEMPERATURE FORECAST AS THE STRONG 5H TROUGH
PIVOTS EAST ACROSS THE REGION INTO FRIDAY NIGHT BEFORE THE FLOW
TURNS MORE ZONAL OVER THE WEEKEND. THIS WILL ALLOW SURFACE HIGH
PRESSURE TO BUILD IN FRIDAY...WITH THE RIDGE ABOUT OVERHEAD SATURDAY...
BEFORE SLIDING TO THE SE SATURDAY NIGHT. HOWEVER BEFORE THE BETTER
SUBSIDENCE ARRIVES ON SATURDAY...WILL SEE A WEAK MID LEVEL WAVE PIVOT
BY TO THE NORTH BY FRIDAY NIGHT WITH AN ASSOCIATED SURFACE TROUGH
CROSSING THE AREA FRIDAY EVENING. ALTHOUGH MOISTURE LOOKS
LIMITED...DEWPOINTS DO INCREASE ACROSS THE SE LATE FRIDAY AS THE FLOW
BACKS MORE SW OUT EAST. LATEST MODELS SUGGEST COULD BE ISOLATED
SHRA/TSRA FROM NW N CAROLINA EAST INTO SOUTHSIDE VIRGINIA WHERE
GUIDANCE SHOWS AFTERNOON CAPE VALUES OF AROUND 1000 J/KG. SINCE IFFY
GIVEN EXTENT OF DRY AIR ALOFT...WILL ONLY INCLUDE A TOKEN ISOLATED
MENTION EXTREME SE NEAR DANVILLE AND POINTS EAST INTO FRIDAY EVENING
WHILE KEEPING ELSEWHERE DRY. MOISTURE SHOULD PIVOT FAR ENOUGH EAST
WITH THE RESIDUAL FRONT ALONG THE COAST TO KEEP THINGS DRY SATURDAY AND
MAINLY SOUTH OF THE MOISTURE AXIS WITH THE NEXT FRONT TO THE NORTH
SATURDAY NIGHT. DOES APPEAR MORE SHEARED HIGH CLOUDS POSSIBLE SATURDAY
AND THEN WARM ADVECTION MID/HIGH CLOUDS AHEAD OF THE FRONT OVERNIGHT AS
MOISTURE TRANSPORT INCREASES FROM THE WEST/SW.
LARGE DIURNAL RANGE IN TEMPERATURES WILL CONTINUE WITH HIGHS MOSTLY 70S
WEST AND LOW/MID 80S EAST BOTH FRIDAY/SATURDAY WITH LOWS AGAIN QUITE
COOL FRIDAY NIGHT IF SKIES CAN CLEAR. THINK BEST TO LEAN TOWARD THE
WARMER MAV MOS EAST BOTH DAYS GIVEN A BUMP IN 85H TEMPS ALOFT AHEAD OF
THE TROUGH FRIDAY...AND BETTER HEATING OF DRY AIR UNDER BACKING FLOW
SATURDAY. STILL LIKELY TO SEE SOME 40S IN THE VALLEYS FRIDAY NIGHT...
AND 50S ELSEWHERE BEFORE THINGS MOISTEN SATURDAY NIGHT WHEN MOST LOWS
WILL STAY IN THE UPPER 50S TO MID 60S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EDT WEDNESDAY...
THE UPPER LEVEL PATTERN DEAMPLIFIES NEXT WEEK WITH A BROADER UPPER
LEVEL TROUGH OVER THE CONUS YIELDING A STEADY STREAM OF WESTERLIES
ALOFT. THE DOMINANT 500MB PLAYERS LOOK TO BE RIDGING NEAR THE
SOUTHERN TIP OF GREENLAND AND A DEVELOPING RIDGE NEAR 40N/140W...
SOUTH OF THE GULF OF ALASKA AND WEST OF CALIFORNIA. IN BETWEEN...
ACROSS THE LOWER 48...WE ARE LEFT WITH A BROAD TROUGH WITH LITTLE
AMPLITUDE...SENSIBLE WEATHER DETERMINED BY SERIES OF SHORT WAVES
THAT WILL PASS THROUGH THE FLOW DURING THE WEEK. AT THE SURFACE
THE DEPARTING AREA OF HIGH PRESSURE THIS WEEKEND WILL BE REPLACED
BY A NEARLY STATIONARY...W-E ORIENTED WAVY FRONT...THAT WILL SET
UP MID CONUS...AND HELPING TO FOCUS SOME OF THE SENSIBLE WEATHER
ELEMENTS DURING THE WEEK.
DETERMINISTIC MODELS ARE QUITE DIFFERENT IN THE TIMING OF THESE
SHORT WAVES...THE GFS A DAY OR TWO FASTER THAN THE ECMWF AT MOVING
THESE FEATURES EAST BOUND. PREFERENCE IS TO GO WITH THE SLOWER
SOLUTIONS...INTRODUCING SLIGHT CHANCE FOR DIURNAL DEEP CONVECTION
WEST OF THE BLUE RIDGE SUNDAY...THEN AREAWIDE MONDAY AND INTO THE
MIDDLE OF NEXT WEEK PER RETURN OF HIGHER DEWPOINTS AND INSTABILITY
COUPLED WITH ANY SHORT WAVE FEATURES THAT PASS VIA THE PREDOMINANT
WESTERLY FLOW ALOFT.
TEMPERATURES AS A WHOLE FOR NEXT WEEK LOOK LIKE THEY WILL PAN OUT TO
BE NORMAL...A GENERAL LACK OF AMPLIFICATION IN THE WEATHER PATTERN
LEADING TO FEWER TEMPERATURE ANOMALIES.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 725 AM EDT THURSDAY...
LOW CIGS STILL STUCK IN BLF THIS MORNING. EXPECT THIS TO ERODE TO
SCATTERED AFTER 14Z...BUT SEEING MORE CLOUDS UPSTREAM ASSOCIATED
WITH EMBEDDED SHORTWAVE THAT WILL PUSH IN BKN/OVC CIGS TO BLF/LWB
BY MIDDAY...ALTHOUGH CIGS SHOULD BE ABOVE 3KFT BY THEN. THE FOG AT
A FEW LOCATIONS WILL BE GONE BY 13Z.
VFR IS EXPECTED...AND WILL SEE A FEW SHOWERS/SPRINKLES CLOSE BY TO
LWB/BLF...BUT NOT ENOUGH OF A COVERAGE AREA TO INCLUDE IN THE
TAFS.
WILL SEE BKN VFR CIGS AS FAR EAST AS THE FOOTHILLS...WITH
SCATTERING OUT OF CLOUDS THIS EVENING. FOG AGAIN A GOOD BET AT
LWB/BCB LATE TONIGHT...BUT CONFIDENCE NOT HIGH IN BRINGING THEM
TOO FAR DOWN...AS NEXT UPSTREAM WAVE MAY BRING CLOUDS IN LATE TO
PREVENT FOG FROM BECOMING DENSE.
EXPECT MAINLY VFR THROUGH THE END OF THE WEEK...WITH HIGH PRESSURE
IN PLACE. VALLEY FOG AT LWB/BCB POSSIBLE EACH MORNING.
HIGH PRESSURE MOVES OFF THE COAST BY SUNDAY WITH A FRONT ARRIVING
SUNDAY OR MONDAY WHICH COULD BRING SHOWERS AND STORMS AND SUB VFR
CEILINGS AND VISIBILITIES TO THE REGION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...KK/WP
SHORT TERM...JH
LONG TERM...PM
AVIATION...AMS/KK/WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
904 AM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 900 AM MDT THU AUG 14 2014
AFTER CHECKING THE 12Z MODEL RUNS AND LATEST SATELLITE...RADAR...
AND SURFACE OBSERVATIONS HAVE MADE SOME ADJUSTMENTS TO THE
FORECAST TODAY. TEMPERATURES ARE STRUGGLING TO WARM OVER MOST OF
THE FORECAST AREA DUE TO THICK CLOUD COVER AND RAIN SHOWERS.
CHEYENNE IS CURRENTLY 70 DEGREES AND NOT LIKELY TO WARM TO MUCH
FURTHER BEFORE SHOWERS DEVELOP. THIS WILL BE SIMILAR TO MUCH OF
THE PLAINS IN SOUTHEAST WYOMING. INTO THE NEBRASKA PANHANDLE...
PLACES LIKE SIDNEY AND ALLIANCE MAY APPROACH 90 DEGREES BEFORE
THICKER CLOUDS MOVE IN...OTHERWISE TEMPERATURES SHOULD GENERALLY
ONLY HIT 80-85 DEGREES TODAY IN THE PANHANDLE.
LOOKING AT WATER VAPOR AND VISIBLE SATELLITE...THE PLACEMENT OF
SHORTWAVE ENERGY IS NOT WHAT THE MODELS WERE SHOWING YESTERDAY.
YESTERDAY MODELS WERE SHOWING ONE SHORTWAVE MOVING ACROSS SOUTHEAST
WYOMING...BUT IN FACT THERE ARE TWO SEPARATE CIRCULATIONS. ONE
OVER CENTRAL WYOMING WHICH IS LIFTING NORTH AND ONE OVER WESTERN
COLORADO MOVING EAST. THEREFORE THE DYNAMIC SETUP IS NOT AS
FAVORABLE FOR SOUTHEAST WYOMING AS EARLIER EXPECTED. THIS MEANS
THE THREAT FOR HEAVY RAIN IS MINIMAL TODAY. ALSO THE 12Z MODELS
ARE SHOWING LESS INSTABILITY AND CAPE TODAY WHICH ALSO SUGGESTS
MINIMAL HEAVY RAIN THREAT. SO FOR THE REST OF TODAY SHOULD SEE
SHOWERS SPREAD EAST INTO THE PLAINS WITH ISOLATED THUNDERSTORMS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
LATEST WATER VAPOR IMAGERY SHOWING THE UPPER LEVEL LOW PUSHING
INTO NORTHWESTERN COLORADO THIS MORNING. LOOKS TO BE HANDLED WELL
BY THE ECMWF. LATEST MOSAIC RADAR SHOWING SHOWERS WIDESPREAD OVER
RIVERTONS CWFA WITH SOME SHOWER ACTIVITY OVER CARBON COUNTY.
MESOWEST OBSERVATIONS REPORTING MEASURABLE RAINFALL OVER THE SNOWY
AND SIERRA MADRE RANGES AS WELL AS THE NORTH LARAMIE RANGE.
FOR TODAY...WE SHOULD SEE AN INCREASE IN SHOWERS AND THUNDERSTORMS
AS THE MORNING PROGRESSES. UPPER LOW MOVES OVER CASPER BY 00Z WITH
FAIRLY WIDESPREAD SHOWERS OVER OUR SOUTHERN ZONES. PWATS FOR
RAWLINS FROM THE NAM UP NEAR 1.2 INCHES AT 18Z...NEAR 1.4 INCHES
HERE AT CHEYENNE BY 00Z AND NEAR 1.7 INCHES AT CHADRON BY 06Z THIS
EVENING. LATEST HRRR FORECAST AND FORECAST IR IMAGERY SHOWING
SHOWERS AND THUNDERSTORMS EAST OF THE LARAMIE RANGE BREAKING OUT
HERE AT CHEYENNE AROUND 15Z AND OUT IN THE PANHANDLE AFTER 18Z.
FORECAST STORM MOTIONS A LITTLE HIGHER THAN PREVIOUSLY FORECAST
WITH NAM SHOWING 10-15KTS. GIVEN THAT STORM MOTIONS ARE
HIGHER...HAVE DECIDED TO HOLD OFF ON A FLASH FLOOD WATCH. WOULD
THINK WE COULD SEE SOME FLASH FLOOD WARNING POSSIBLE THIS
AFTERNOON...BUT THESE WILL BE FOR TRAINING STORMS AND NOT FOR SLOW
MOVING STORMS. MAY TAKE ANOTHER LOOK LATER THIS MORNING WHEN THE
06Z MODEL DATA COMES OUT.
LOOKS LIKE SHOWERS AND THUNDERSTORMS WILL COME TO AN END BY 06Z
TONIGHT AS THE ECMWF SHOWS SHORTWAVE MOVING INTO CENTRAL SOUTH
DAKOTA AND CENTRAL NEBRASKA. STILL SOME POSITIVE VORTICITY
ADVECTION OVER THE NORTHERN PANHANDLE FRIDAY MORNING...SO DID KEEP
SOME SLIGHT CHANCE POPS GOING OUT THAT WAY FOR FRIDAY MORNING AND
AFTERNOON.
UPPER RIDGE BUILDS BACK INTO THE AREA FRIDAY NIGHT INTO SATURDAY AS
SHORTWAVE BEGINS TO MOVE SOUTHEAST INTO EASTERN KANSAS. 700MB
WINDS PICKING UP TO 20-25KTS ACROSS THE CWFA MAY LEAD TO
HEIGHTENED FIRE WEATHER CONCERNS SATURDAY...MORE LIKELY THOUGH ON
SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
SATURDAY NIGHT...DRY PERIOD WITH LIMITED LOW AND MID LEVEL MOISTURE
AND DOWNSLOPE WEST WINDS.
SUNDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES ACROSS EASTERN MONTANA
AND EASTERN WYOMING WITH AN ASSOCIATED SURFACE TROUGH. ISOLATED
SHOWERS AND THUNDERSTORMS EXPECTED...NORTH OF A DOUGLAS TO
SCOTTSBLUFF LINE.
MONDAY...RELATIVELY DRY NORTHWEST FLOW ALOFT PREVAILS...THOUGH LOOKS
LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR ISOLATED LATE DAY SHOWERS
AND THUNDERSTORMS FROM WHEATLAND TO ALLIANCE.
TUESDAY...SLIGHT DECREASE IN LOW AND MID LEVEL MOISTURE...ACTING AS
THE FUEL FOR THUNDERSTORMS...THUS ONLY ISOLATED STORMS AT
BEST...NORTH OF A RAWLINS TO SCOTTSBLUFF LINE.
WEDNESDAY...DRY WEST WINDS PREVAIL IN THE LOW AND MID
LEVELS...EFFECTIVELY DRYING OUT THE ATMOSPHERE EVEN MORE...AND
PRODUCING A MILD LATE AUGUST DAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 521 AM MDT THU AUG 14 2014
EXPECT INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
THE MORNING HOURS FOR KRWL AND KLAR WITH SHOWERS SPREADING EAST
THIS AFTERNOON. SOME OF THE STRONGER STORMS WILL PRODUCE HEAVY
RAINFALL THAT COULD REDUCE FLIGHT CONDITIONS TO IFR CONDITIONS
THROUGH THE AFTERNOON HOURS. SHOWERS ENDING LATE THIS EVENING FROM
WEST TO EAST.
&&
.FIRE WEATHER...
ISSUED AT 350 AM MDT THU AUG 14 2014
WIDESPREAD WETTING RAINS TODAY BEGINNING OVER CARBON COUNTY...THEN
SPREADING EAST. THIS IS DUE TO A UPPER LEVEL LOW PRESSURE SYSTEM
MOVING SLOWLY NORTHEAST AND INTERACTING WITH MONSOONAL MOISTURE
OVER THE AREA. THIS LOW WILL KEEP UNSETTLED WEATHER OVER SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE THROUGH FRIDAY AFTERNOON AS THE LOW
SLOWLY MOVES OUT OF THE AREA. DRIER CONDITIONS AFTER FRIDAY
AFTERNOON AS WESTERLY WINDS RETURN. AFTERNOON HUMIDITIES SATURDAY
AND SUNDAY WILL LOOK TO BECOME CRITICAL WEST OF THE LARAMIE RANGE.
GUSTY WESTERLY WINDS AS WELL BOTH AFTERNOONS THAT COULD REACH
CRITICAL CRITERIA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
525 AM MDT THU AUG 14 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
LATEST WATER VAPOR IMAGERY SHOWING THE UPPER LEVEL LOW PUSHING
INTO NORTHWESTERN COLORADO THIS MORNING. LOOKS TO BE HANDLED WELL
BY THE ECMWF. LATEST MOSAIC RADAR SHOWING SHOWERS WIDESPREAD OVER
RIVERTONS CWFA WITH SOME SHOWER ACTIVITY OVER CARBON COUNTY.
MESOWEST OBSERVATIONS REPORTING MEASURABLE RAINFALL OVER THE SNOWY
AND SIERRA MADRE RANGES AS WELL AS THE NORTH LARAMIE RANGE.
FOR TODAY...WE SHOULD SEE AN INCREASE IN SHOWERS AND THUNDERSTORMS
AS THE MORNING PROGRESSES. UPPER LOW MOVES OVER CASPER BY 00Z WITH
FAIRLY WIDESPREAD SHOWERS OVER OUR SOUTHERN ZONES. PWATS FOR
RAWLINS FROM THE NAM UP NEAR 1.2 INCHES AT 18Z...NEAR 1.4 INCHES
HERE AT CHEYENNE BY 00Z AND NEAR 1.7 INCHES AT CHADRON BY 06Z THIS
EVENING. LATEST HRRR FORECAST AND FORECAST IR IMAGERY SHOWING
SHOWERS AND THUNDERSTORMS EAST OF THE LARAMIE RANGE BREAKING OUT
HERE AT CHEYENNE AROUND 15Z AND OUT IN THE PANHANDLE AFTER 18Z.
FORECAST STORM MOTIONS A LITTLE HIGHER THAN PREVIOUSLY FORECAST
WITH NAM SHOWING 10-15KTS. GIVEN THAT STORM MOTIONS ARE
HIGHER...HAVE DECIDED TO HOLD OFF ON A FLASH FLOOD WATCH. WOULD
THINK WE COULD SEE SOME FLASH FLOOD WARNING POSSIBLE THIS
AFTERNOON...BUT THESE WILL BE FOR TRAINING STORMS AND NOT FOR SLOW
MOVING STORMS. MAY TAKE ANOTHER LOOK LATER THIS MORNING WHEN THE
06Z MODEL DATA COMES OUT.
LOOKS LIKE SHOWERS AND THUNDERSTORMS WILL COME TO AN END BY 06Z
TONIGHT AS THE ECMWF SHOWS SHORTWAVE MOVING INTO CENTRAL SOUTH
DAKOTA AND CENTRAL NEBRASKA. STILL SOME POSITIVE VORTICITY
ADVECTION OVER THE NORTHERN PANHANDLE FRIDAY MORNING...SO DID KEEP
SOME SLIGHT CHANCE POPS GOING OUT THAT WAY FOR FRIDAY MORNING AND
AFTERNOON.
UPPER RIDGE BUILDS BACK INTO THE AREA FRIDAY NIGHT INTO SATURDAY AS
SHORTWAVE BEGINS TO MOVE SOUTHEAST INTO EASTERN KANSAS. 700MB
WINDS PICKING UP TO 20-25KTS ACROSS THE CWFA MAY LEAD TO
HEIGHTENED FIRE WEATHER CONCERNS SATURDAY...MORE LIKELY THOUGH ON
SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
SATURDAY NIGHT...DRY PERIOD WITH LIMITED LOW AND MID LEVEL MOISTURE
AND DOWNSLOPE WEST WINDS.
SUNDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES ACROSS EASTERN MONTANA
AND EASTERN WYOMING WITH AN ASSOCIATED SURFACE TROUGH. ISOLATED
SHOWERS AND THUNDERSTORMS EXPECTED...NORTH OF A DOUGLAS TO
SCOTTSBLUFF LINE.
MONDAY...RELATIVELY DRY NORTHWEST FLOW ALOFT PREVAILS...THOUGH LOOKS
LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR ISOLATED LATE DAY SHOWERS
AND THUNDERSTORMS FROM WHEATLAND TO ALLIANCE.
TUESDAY...SLIGHT DECREASE IN LOW AND MID LEVEL MOISTURE...ACTING AS
THE FUEL FOR THUNDERSTORMS...THUS ONLY ISOLATED STORMS AT
BEST...NORTH OF A RAWLINS TO SCOTTSBLUFF LINE.
WEDNESDAY...DRY WEST WINDS PREVAIL IN THE LOW AND MID
LEVELS...EFFECTIVELY DRYING OUT THE ATMOSPHERE EVEN MORE...AND
PRODUCING A MILD LATE AUGUST DAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 521 AM MDT THU AUG 14 2014
EXPECT INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH
THE MORNING HOURS FOR KRWL AND KLAR WITH SHOWERS SPREADING EAST
THIS AFTERNOON. SOME OF THE STRONGER STORMS WILL PRODUCE HEAVY
RAINFALL THAT COULD REDUCE FLIGHT CONDITIONS TO IFR CONDITIONS
THROUGH THE AFTERNOON HOURS. SHOWERS ENDING LATE THIS EVENING FROM
WEST TO EAST.
&&
.FIRE WEATHER...
ISSUED AT 350 AM MDT THU AUG 14 2014
WIDESPREAD WETTING RAINS TODAY BEGINNING OVER CARBON COUNTY...THEN
SPREADING EAST. THIS IS DUE TO A UPPER LEVEL LOW PRESSURE SYSTEM
MOVING SLOWLY NORTHEAST AND INTERACTING WITH MONSOONAL MOISTURE
OVER THE AREA. THIS LOW WILL KEEP UNSETTLED WEATHER OVER SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE THROUGH FRIDAY AFTERNOON AS THE LOW
SLOWLY MOVES OUT OF THE AREA. DRIER CONDITIONS AFTER FRIDAY
AFTERNOON AS WESTERLY WINDS RETURN. AFTERNOON HUMIDITIES SATURDAY
AND SUNDAY WILL LOOK TO BECOME CRITICAL WEST OF THE LARAMIE RANGE.
GUSTY WESTERLY WINDS AS WELL BOTH AFTERNOONS THAT COULD REACH
CRITICAL CRITERIA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
323 PM MDT THU AUG 14 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM MDT THU AUG 14 2014
WEATHER IS BEHAVING ABOUT AS EXPECTED THIS AFTERNOON. A FEW HEAVY
RAINERS HAVE DUMPED AROUND AN INCH IN SPOTS BUT NO MAJOR ISSUES
AS OF YET. THIS HEAVY RAIN THREAT WILL CONTINUE INTO THE EARLY
EVENING HOURS. MAIN LINE OF ACTIVITY IS JUST COMING OFF THE
FOOTHILLS AT 2030Z AND SHOULD SPREAD EAST ACROSS THE PLAINS OVER
THE NEXT SEVERAL HOURS. HRRR HAS ACTIVITY ENDING AROUND MIDNIGHT.
UPPER TROUGH IS OVER THE MOUNTAINS RIGHT NOW WITH QUASIGEOSTROPHIC
ASCENT HELPING THINGS OUT AHEAD OF IT AND TENDING TO SQUASH MOST
BUT NOT ALL CONVECTION OVER WESTERN COLORADO. THIS SUBSIDENCE WILL
BECOME MORE PREVALENT OVERNIGHT ACROSS THE AREA AND STRENGTHEN
TOMORROW. THIS SHOULD CLEAR TONIGHT /PER CIRA SYNTHETIC SATELLITE
IMAGERY/ AND WILL COUPLE WITH LESS MOISTURE AND LOW-LEVEL
DOWNSLOPE FLOW EAST OF THE MOUNTAINS TO LESSEN THE CONVECTIVE
ACTIVITY FRIDAY AFTERNOON. WITH LESS SHOWER/THUNDERSTORM/CLOUDS
MINIMUM TEMPERATURES SHOULD BE LOWER TONIGHT WITH MAXIMA TOMORROW
A FEW DEGREES WARMER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM MDT THU AUG 14 2014
UPPER RIDGING WILL BUILD OVER COLORADO AND THE WESTERN U.S.
THROUGH THE WEEKEND...BRINGING AN EVENTUAL DECREASE IN AFTERNOON
AND EVENING THUNDERSTORM ACTIVITY. MOISTURE WILL LINGER OVER THE
REGION WHICH WILL BE AVAILABLE TO FUEL DIURNAL THUNDERSTORM
ACTVITIY EACH DAY...BUT RISING HEIGHTS MAY ALSO PRODUCE MID-LEVEL
INVERSIONS THAT CAP OFF CONVECTIVE DEVELOPMENT. FOR THE TIME BEING
WILL STICK WITH POPS IN THE 20-30 PERCENT RANGE...PRIMARILY OVER
THE MOUNTAINS AND FOOTHILLS. BY EARLY NEXT WEEK...BUILDING HIGH
PRESSURE OFF THE OREGON COAST WILL LEAVE COLORADO UNDER A WEAK
AND PERSISTENT NORTHWESTERLY FLOW ALOFT. THE GENERAL PATTERN
ACROSS THE COUNTRY WILL BE LOW AMPLITUDE AND PROGRESSIVE. THIS
SHOULD KEEP TEMPERATURES AROUND SEASONAL NORMALS AND PRECLUDE THE
ACCUMULATION OF EXCESSIVE MOISTURE OVER THE STATE. THE MIDDLE OF
NEXT WEEK MAY BE ENTIRELY DRY...BUT THE ABSENCE OF STRONGER
RIDGING IN THE MODEL SOLUTIONS WILL KEEP ME FROM PULLING AFTERNOON
THUNDERSTORMS OUT OF THE FORECAST.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z FRIDAY LATE AFTERNOON)
ISSUED AT 323 PM MDT THU AUG 14 2014
CONVECTION COMING OFF THE HILLS WILL BRING ISSUES TO ALL TERMINALS
THROUGH AROUND 00Z OR SO WITH ACTIVITY EAST OF THE METRO AREA BY
THEN. WINDS WILL BE MESSY AS IT PASSES BUT WE MAY STILL BE ABLE TO
GET A MORE GENERAL WESTERLY FLOW FOR A COUPLE OF HOURS AFTER THE
LINE PASSES. THIS WILL THEN TRANSITION TO DRAINAGE LATER IN THE
EVENING. SOME HINT OF NORTHWESTERLIES IN THE 10-15 KNOT RANGE
TOMORROW AFTERNOON BEHIND TODAY/S SYSTEM.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...ET
LONG TERM...DANKERS
AVIATION...ET
AREA FORECAST DISCUSSION
NWS PUEBLO CO
310 PM MDT THU AUG 14 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
...FLASH FLOOD POTENTIAL TO CONTINUE THROUGH THIS EVENING FOR THE
CONTINENTAL DIVIDE AND PIKES PEAK REGION...
SHORTWAVE CURRENTLY MOVING ACROSS NORTHERN CO HAS INITIATED
THUNDERSTORMS OVER THE PIKES PEAK REGION THIS AFTERNOON. HIGH
PRECIPITABLE WATERS RUNNING 150+% OF NORMAL IS ALLOWING FOR
EFFICIENT RAINFALL RATES AS EVIDENCED FROM RADAR KDP/S AND SPOTTER
REPORTS. THERE HAVE ALSO BEEN SOME PEA SIZE HAIL REPORTS WITH THE
STRONGER STORMS. AS THE SHORTWAVE CONTINUES TO DRAG ACROSS EASTERN
COLORADO...THUNDERSTORMS WILL CONTINUE TO SPREAD EASTWARD ACROSS THE
PLAINS. STORMS HAVE BEEN MOVING NORTHEAST AT 15 MPH...ENOUGH TO
ABATE SOME OF THE FLASH FLOOD RISK...BUT NOT ENTIRELY NEGATE IT AS
HEAVY RAINFALL RATES OF AROUND 2 INCHES PER HOUR CAN STILL CAUSE
PROBLEMS FOR THE BURN SCARS AND URBAN AREAS. THUS WILL KEEP THE
FLASH FLOOD WATCH GOING THROUGH 9 PM. BEEN A LITTLE HARDER TO GET
STRONGER CONVECTION GOING OUT WEST ALONG THE CONTINENTAL DIVIDE AND
SUSPECT THAT THREAT THERE IS RAPIDLY DIMINISHING AS STABILITY HAS
BEEN A FACTOR WITH THE CLOUD COVER AND EARLIER RAINFALL. WILL KEEP
THE WATCH GOING THROUGH THE PRIME HEATING HOURS...BUT SUSPECT THAT
WE MAY BE ABLE TO TAKE DOWN THE WATCH BY 6 PM FOR CHAFFEE/LAKE
COUNTIES AND THE EASTERN SAN JUANS AND LA GARITAS.
THUNDERSTORMS WILL SPREAD EASTWARD ACROSS THE PLAINS THROUGH THE
EVENING HOURS. LATEST HRRR SUGGESTS THAT THREAT FOR PIKES PEAK AREA
MAY BE ENDED BY 6-7 PM. HIGHEST POPS THROUGH THE EVENING HOURS WILL
BE ACROSS THE SOUTHEAST PLAINS AS THUNDERSTORMS DEVELOP ALONG
SOUTHWARD ADVANCING COLD FRONT. APPEARS BEST LIFT MAY BE ACROSS
NORTHWEST KANSAS AND EAST CENTRAL CO (KIOWA COUNTY) AS LOW LEVEL JET
IMPINGES ON THE FRONT...SO WILL KEEP HIGHEST POPS UP THAT WAY. MOST
OF THE ACTIVITY WILL BE DONE BY MIDNIGHT AS LINE OF THUNDERSTORMS
MOVES EAST INTO KANSAS.
A LITTLE LESS ACTIVE WEATHER IS EXPECTED TOMORROW. PRECIPITABLE
WATERS WILL DROP OFF BELOW 1 INCH FOR THE I-25 CORRIDOR AND
WESTWARD. STILL LOOKING AT SUFFICIENT MOISTURE FOR ISOLATED TO
SCATTERED THUNDERSTORMS...SO STILL CAN`T RULE OUT HEAVY RAIN ON BURN
SCARS AND POTENTIAL FOR FLASH FLOODING. BUT THREAT CERTAINLY LOOKS
LOWER DUE TO THE MORE ISOLATED NATURE OF THESE STRONGER CELLS.
GRIDS WILL CARRY MORE OF A DIURNAL POP TREND...WITH THUNDERSTORMS
FIRING OVER THE MOUNTAINS AROUND NOON...THEN DEVELOPING/SPREADING
EASTWARD ACROSS THE ADJACENT PLAINS DURING THE LATE AFTERNOON. -KT
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM MDT THU AUG 14 2014
FRIDAY NIGHT-THURSDAY...NOT MUCH CHANGE IN THE ONGOING FORECAST
THROUGH THE EXTENDED PERIOD WITH FLAT UPPER LEVEL RIDGING REMAINING
IN PLACE ACROSS THE GREAT BASIN THROUGH THE ROCKIES. THIS WILL KEEP
MONSOONAL MOISTURE PLUME SOUTH AND SOUTHWEST OF THE STATE WITH WEAK
WEST TO NORTHWEST FLOW ALOFT ACROSS THE STATE AND WEATHER SYSTEMS
MOVING ACROSS THE NORTHERN TIER OF STATES AND INTO THE UPPER
MIDWEST.
THERE LOOKS TO BE ENOUGH RESIDUAL MOISTURE IN PLACE TO WORK WITH
LATE SUMMER SOLAR HEATING TO KEEP ISOLATED TO SCATTERED AFTERNOON
AND EVENING STORMS IN THE FORECAST OVER AND NEAR THE HIGHER
TERRAIN...WITH A FEW STORMS POSSIBLY ROLLING ACROSS THE FAR SE
PLAINS THROUGH THE LATE EVENING AND OVERNIGHT HOURS. STORMS THAT DO
DEVELOP SHOULD BE GENERALLY HIGH BASED...THOUGH STILL CAN NOT RULE
OUT LOCALIZED HEAVY RAINFALL AND SMALL HAIL WITH STRONGER CELLS.
HARD TO PIN POINT BEST COVERAGE OF STORMS THOUGH COULD SEE INCREASED
COVERAGE SUNDAY THROUGH SUNDAY NIGHT AND AGAIN TUESDAY AND TUESDAY
NIGHT AS EMBEDDED DISTURBANCES MOVE ACROSS THE NORTHERN ROCKIES AND
INTO THE HIGH PLAINS. WITH RIDGING IN PLACE...TEMPERATURES ACROSS
THE AREA LOOK TO BE GENERALLY AT OR SLIGHTLY ABOVE LATE SUMMER
AVERAGES THROUGH THE PERIOD.
THERE COULD BE A CHANGE IN THE PATTERN INTO EARLY NEXT WEEKEND...AS
A BROAD UPPER TROUGH TRIES TO CARVE OUT ACROSS THE WEST COAST
OPENING THE DOOR TO INCREASING MOISTURE WITHIN DEVELOPING SOUTH TO
SOUTHWEST FLOW ALOFT ACROSS THE DESERT SOUTHWEST AND INTO THE
ROCKIES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 310 PM MDT THU AUG 14 2014
THUNDERSTORMS WILL CONTINUE THROUGH THROUGH THE EVENING HOURS FOR
THE MOUNTAINS AND I-25 CORRIDOR WITH THREAT FOR TSRA AT TERMINALS TO
CONTINUE UNTIL 00-01Z. CIGS COULD DROP INTO THE MVFR TO EVEN BRIEF
IFR CATEGORY UNDER THE STRONGER STORMS WITH HEAVY RAIN AND PEA SIZE
HAIL POSSIBLE. THUNDERSTORMS WILL END FROM WEST TO EAST AT THE
TERMINALS THROUGH THE EVENING WITH VFR CONDITIONS EXPECTED
OVERNIGHT. THREAT FOR THUNDERSTORMS WILL BE LESS TOMORROW AND
MAINLY CONFINED TO THE MOUNTAIN AREAS THOUGH THE AFTERNOON...THOUGH
A FEW MAY DRIFT INTO THE SOUTHEAST PLAINS DURING THE EVENING. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 9 PM MDT THIS EVENING FOR COZ058>068-081-
082-084-085.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...KT/MW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1252 PM CDT THU AUG 14 2014
.DISCUSSION...
302 AM CDT
SHORT TERM (THROUGH TONIGHT)...
HIGH PRESSURE IS CENTERED THIS MORNING OVER ONTARIO WITH RIDGING
EXTENDING SOUTH ALONG THE UPPER AND MID MISSISSIPPI VALLEY. UPPER
PATTERN IS AMPLIFIED WITH A CLOSED LOW ANALYZED OVER THE EASTERN
GREAT LAKES WITH RIDGING ACROSS THE PLAINS LEAVING THE LOCAL AREA
UNDER NORTHWEST FLOW ALOFT. SOME CIRRUS STREAMING DOWN THE LEE SIDE
OF THE RIDGE WILL OCCUR THROUGH THE DAY...OTHERWISE DRIER LOW LEVELS
BEHIND A DEPARTING COLD FRONT SHOULD RESULT IN MOSTLY SUNNY SKIES.
SURFACE WINDS OFF THE LAKE THROUGH THE DAY WILL KEEP TEMPERATURES A
BIT COOLER...LIKELY STRUGGLING TO REACH 70 IMMEDIATELY NEAR THE LAKE
FRONT...BUT RISING INTO THE MID 70S FARTHER INLAND.
TONIGHT...THE HIGH WILL MOVE SOUTH ACROSS THE LOCAL AREA WITH WINDS
DROPPING OFF AND LIKELY GOING VARIABLE OR CALM FOR A PERIOD...THEN
TURN SOUTHWEST BY LATE TONIGHT AS THE HIGH HEADS TOWARDS THE UPPER
OHIO RIVER VALLEY. TEMPERATURES ARE EXPECTED TO DROP INTO THE LOW TO
MID 50S TONIGHT OUTSIDE OF THE CITY...WHICH WILL STAY AROUND 60.
DEUBELBEISS
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
PRIMARY FORECAST CHALLENGE IS PRECIP CHANCES THROUGH THE WEEKEND
INTO EARLY NEXT WEEK ASSOCIATED WITH FAIRLY STRONG SHORTWAVE OVER
THE ROCKIES THAT WILL CREST THE UPPER RIDGE BEFORE DROPPING
SOUTHEAST INTO OUR NECK OF THE WOODS OVER THE WEEKEND.
FIRST...GFS HAS ABANDONED THE MORE PHASED SOLUTION OF LAST NIGHT AND
IS NOW THE OPERATIONAL RUN OF THE GFS AND ENSEMBLE MEAN ARE FAIRLY
TIGHTLY CLUSTERED WITH THE ECMWF/GEM SOLUTIONS. THE LESS PHASED
SOLUTION ADDS CONFIDENCE TO A SLOWER MOVEMENT AND LATER ONSET TO THE
START TIME OF PRECIP CHANCES THIS WEEKEND. IN ADDITION...ALL MEDIUM
RANGE MODELS HAVE TRENDED STRONGER WITH THIS SHORTWAVE AND MORE
IMPORTANTLY SIGNIFICANTLY FARTHER SOUTHWEST WITH THE TRACK. THE
LATEST MEDIUM GUIDANCE WOULD ACTUALLY OPEN THE DOOR TO THE
POSSIBILITY THAT MUCH OF THE UPCOMING WEEKEND COULD END UP
DRY...ESPECIALLY NORTHEASTERN CWA AS THE SYSTEM CUTS OFF OVER
NORTHERN MISSOURI SAT INTO EARLY SUNDAY. BY SUNDAY NIGHT INTO EARLY
NEXT WEEK GUIDANCE SUGGESTS THE WAVE WILL TAKE MORE OF A LEFT TURN
AND TRACK EASTERLY AS THE NE NOAM TROUGH DISSIPATES AND THE FLOW
FLATTENS OUT AND NEXT UPSTREAM WAVE ACTS AS A KICKER GIVING THIS
MORE CUT OFF SYSTEM THE BOOT EASTWARD.
GIVEN THE RECENT VARIABILITY IN MODEL SOLUTIONS AND THEIR PROPENSITY
TO STRUGGLE HANDLING CLOSED LOWS...PARTICULARLY FEATURES DETACHED
FROM THE MAIN BELT OF WESTERLIES LIKE THIS ONE SHOULD BE...FORECAST
CONFIDENCE IS VERY LOW SATURDAY INTO EARLY NEXT WEEK. IN LINE WITH
THE LATEST GUIDANCE HAVE BEGUN TO TREND POPS A BIT LOWER OVER THE
WEEKEND...THOUGH ONLY MADE MODEST ADJUSTMENTS DOWNWARD GIVEN THE LOW
FORECAST CONFIDENCE. IF CURRENT TRENDS PERSIST...THEN MUCH OF THE
UPCOMING WEEKEND COULD POTENTIALLY END UP BEING DRY...BUT WILL LET
LATER SHIFTS MAKE ANY MORE SUBSTANTIAL CHANGES TO PRECIP CHANCES.
COMBINATION OF THE EASTWARD MOVING CLOSED LOW SOMEWHERE IN THE
REGION FOLLOWED BY NORTHERN STREAM SHORTWAVE THAT BOOTS OUT THE UPPER
LOW...HAVE TO MAINTAIN POPS ON A DAILY BASIS THROUGH THE REST OF THE
EXTENDED NEXT WEEK.
TEMPERATURE-WISE...TREND SHOULD BE TOWARD WARMING UP TO MORE
SEASONABLE LEVELS...THOUGH A WEAK IL SHORE LAKE BREEZE COULD PROVIDE
A BIT OF COOLING FRIDAY BEFORE STRONGER OFFSHORE GRADIENT BRINGS THE
WARMTH AND INCREASED HUMIDITY TO THE LAKEFRONT SATURDAY AFTERNOON.
BY SUNDAY INTO EARLY NEXT WEEK...SURFACE REFLECTION OF THE CUT OFF
LOW WILL DEVELOP TO OUR SOUTHWEST WHICH SHOULD RESULT IN MORE OF AN
ONSHORE COMPONENT WITH SOME ATTENDANT LAKE COOLING...THOUGH INLAND
TEMPS LOOK TO REMAIN SEASONABLY WARM.
IZZI
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NORTHEAST WINDS AROUND 10 KT AT TIMES THIS AFTERNOON
KMD
//DISCUSSION...UPDATED 18Z...
FAIRLY QUIET CONDITIONS ACROSS THE TERMINALS THIS AFTERNOON...JUST
SOME SCATTERED AFTERNOON CUMULUS DEVELOPMENT AND NORTH TO
NORTHEAST WINDS AT 10 KT OR LESS AS HIGH PRESSURE CONTINUES TO
PUSH SOUTH. THE HIGH SPREADS OVERHEAD TONIGHT RESULTING IN LIGHT
AND VARIABLE WINDS ...THEN AS HIGH PRESSURE SLOWLY SHIFTS
EAST FRIDAY...WINDS WILL TURN SOUTHWESTERLY THROUGH THE DAY. WINDS
SHOULD GENERALLY REMAIN UNDER 10 KT...POSSIBLY GETTING CLOSE LATE
IN THE DAY. CURRENT FEELING IS IF THERE IS ANY LAKE BREEZE IT WOULD BE
CONFINED IN FAR NORTHEAST ILLINOIS AND NEAR THE SHORE. VFR
CONDITIONS THROUGH THE PERIOD.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH IN ALL ELEMENTS
KMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT THROUGH WEDNESDAY...PERIODIC CHANCES FOR TSRA.
PRIMARILY VFR.
BMD
&&
.MARINE...
319 AM CDT
A COLD FRONT HAS DROPPED SOUTH ACROSS LAKE MICHIGAN OVERNIGHT WITH
MODERATE NORTHERLY FLOW IN THE WAKE OF THE FRONT. HIGH PRESSURE
CURRENTLY CENTERED OVER ONTARIO WILL BUILD SOUTH THROUGH THE DAY
ALLOWING WINDS TO GRADUALLY DIMINISH...BUT WITH COLD ADVECTION AND
MODERATE WINDS...SIGNIFICANT WAVE HEIGHTS IN THE 4 TO 6 FT RANGE
ARE EXPECTED TO PERSIST THROUGH THE MORNING BEFORE TAPERING SOME
MIDDAY. WINDS WILL BEGIN TO TURN SOUTHERLY THROUGH THE DAY FRIDAY
INTO SATURDAY AS THE HIGH MOVES OVER THE UPPER OHIO VALLEY.
ANOTHER COLD FRONT IS EXPECTED TO DROP ACROSS LAKE MICHIGAN
SATURDAY INTO SATURDAY NIGHT.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...BEACH HAZARDS STATEMENT...ILZ006-ILZ014 UNTIL 7 PM THURSDAY.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002 UNTIL 7 PM THURSDAY.
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
NATIONAL WEATHER SERVICE LINCOLN IL
1213 PM CDT Thu Aug 14 2014
.UPDATE...
ISSUED AT 952 AM CDT THU AUG 14 2014
Cold front was located roughly along the I-74 corridor this
morning, where winds shift from northwest to northeast. No
significant temperature difference immediately along the front,
but much drier dew points (upper 40s/lower 50s) are upstream in
northeast Illinois. Latest HRRR continues to show some very light
showers/sprinkles speckled along the front during the afternoon,
which has already been accounted for in the hourly weather grids.
Little change was needed to the existing grids, except to lower
the dew points across the northeast CWA as the drier air moves in
from the northeast.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 328 AM CDT THU AUG 14 2014
Another spoke of energy is pivoting around the pesky upper low over
eastern Canada. This particular wave of interest is diving across
the western Great Lakes, and is helping to push a weak frontal
boundary south across Illinois. In the latest surface analysis, this
surface boundary lies in the vicinity of the I-74 corridor across
central Illinois. While this boundary is weak and moisture starved,
a main concern today is if it will successfully produce any rainfall.
Some spotty showers have been along the boundary through the night,
although a more notable impact has been a thick band of AC. Much of
the model guidance has been insisting for days that some rainfall
will accompany this front today, and even some of the short-term
mesoscale models are now doing the same. Still, given what has
occurred upstream, and progged moisture profiles in local forecast
soundings, have a hard time believing we`ll see more than virga
and/or sprinkles. So, plan to keep PoPs below the measurable rain
threshold today (15%), but will mention a slight chance of sprinkles
accompanying the front as it sinks south. The front pretty much
washes out by tonight, so do not expect the risk of sprinkles to
extend beyond this afternoon. Below normal temperatures will
continue through tonight, especially as you head north/east of the
decaying front.
&&
.LONG TERM...(Friday through Wednesday)
ISSUED AT 328 AM CDT THU AUG 14 2014
The nice stretch of summer weather will continue through Friday
evening with most areas staying dry and temperate as 1018 mb surface
high pressure ridge settles east of IL into the Ohio river valley on
Friday. Partly sunny skies expected on Friday with highs mostly in
the lower 80s and dew points elevating into the low to mid 60s Friday
afternoon with SSE winds 5-10 mph.
Most models now keep central/SE IL dry Friday evening with some qpf
moving into mainly western areas after midnight Friday night as
short waves eject east from the central Rockies across the MO
valley. Better chance of showers and thunderstorms to spread further
east during Saturday especially Saturday afternoon into Saturday
night. SPC has slight risk of severe storms Saturday SW of central
IL CWA but 5% risk of hail/wind as far NE as I-74 due to increase
wind shear and instability as dew points rise into the upper 60s to
around 70F by Sat afternoon.
Northwest upper level flow will become more zonal early next week as
upper level trof/low moves into IL. Weather to be more unsettled
from this weekend into at least early next work week. Models still
differ on timing of this feature but currently have daily chances of
showers and thunderstorms from this weekend through early next work
week with highest chances Saturday night through Monday. Tropical
humidity will return to IL during this weekend and linger into next
work week as dew points climb into the upper 60s and lower 70s. Highs
80-85F this weekend and Monday will climb into the mid to upper 80s
by middle of next week with a few spots in SW areas approaching 90.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
ISSUED AT 1212 PM CDT THU AUG 14 2014
VFR conditions expected through the period. Weak surface boundary
located roughly along a KPIA-KCMI line to sink a bit further south
this afternoon, before washing out. High-resolution models
continue to show very light showers/sprinkles through the
afternoon along the boundary, so will maintain the VCSH mention
for a few more hours. Skies expected to mainly be clear overnight
with high pressure nearly overhead, with some high clouds
spreading in from the northwest late. Winds behind the front this
afternoon will mainly be from the northeast, but trend more
northwest to northeast along the front itself. By late Friday
morning, a more consistent east-southeast flow is on tap.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEELHART
SHORT TERM...BAK
LONG TERM...07
AVIATION...GEELHART
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1229 PM CDT THU AUG 14 2014
.SHORT TERM /TODAY/...
ISSUED AT 340 AM CDT THU AUG 14 2014
RIDGE OF HIGH PRESSURE OVER THE NORTHERN GREAT LAKES AND SOUTHERN
CANADA WILL HOLD FOR ANOTHER DAY TODAY AS IT SLOWLY DRIFTS EAST.
PATCHY FOG...A FEW AREAS OF DENSE FOG THIS MORNING SHOULD LIFT
QUICKLY BY 13Z SHORTLY AFT SUNRISE. LOW PRESSURE OVER THE CENTRAL
ROCKIES WILL MOVE LITTLE THROUGH THIS AFTERNOON. HOWEVER...A WARM
FRONT STRETCHING EAST SOUTHEAST FROM THE LOW OVER SOUTHERN KANSAS
WILL BEGIN TO LIFT NORTH DURING THE AFTERNOON INTO NORTHERN
KANSAS. WARM AIR ADVECTION ALOFT AND A WEAK WAVE WILL CONTINUE AN
AREA OF SHOWERS AND THUNDERSTORMS OVER SOUTH DAKOTA WHICH SHOULD
GENERALLY REMAIN NORTHWEST OF THE REGION THROUGH LATE TODAY.
CIRRUS CONTINUE TO SPILL OVER THE H700 RIDGE TONIGHT...AND EXPECT
SOME HIGH CLOUDS TO CROSS THE REGION THIS AFTERNOON AND TONIGHT.
BY LATE AFTERNOON THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND ISO
THUNDER FAR NORTHWEST AS THE NORTHERN STREAM SHORTWAVE APPROACHES
THE AREA. BOTH SYNOPTIC SCALE MODELS AND THE HRRR INCREASE FORCING
ACROSS THE FAR NORTHWEST THIS AFTERNOON. HIGHS TODAY WITH THE
POTENTIAL FOR MORE CLOUDS NORTHWEST AND INCREASING HIGH CLOUDS
ELSEWHERE...SHOULD HOLD HIGHS IN THE UPPER 70S TO LOWER 80S REGION
WIDE.
.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
ISSUED AT 340 AM CDT THU AUG 14 2014
THE FIRST WAVE ARRIVES TONIGHT WITH MOISTURE INCREASING ALOFT INTO
AN UPPER LEVEL BOUNDARY ACROSS THE REGION. MODELS CONTINUE TO SHOW
INCREASING THETAE ADVECTION FROM 00Z TO 12Z FRIDAY OVER THE FORECAST
AREA. FLOW AT H850 REMAINS WEAK WITH SLOWLY EXITING HIGH PRESSURE TO
THE EAST. THIS WILL ALLOW ANY CONVECTION TO GRADUALLY WEAKEN
OVERNIGHT AS IT PUSHES ACROSS THE NORTHEAST WITH SHOWERS AND PERHAPS
ISOLATED THUNDER THROUGH FRIDAY MORNING. BY FRIDAY AFTERNOON...
DAYTIME HEATING...INCREASED MOISTURE TRANSPORT AND STRENGTHENING
H850 WINDS SHOULD INCREASE THE SHOWERS AND THUNDERSTORM ACTIVITY
OVER THE AREA ACROSS THE NORTHEAST AND SOUTHWEST. RAINFALL AMOUNTS
WILL REMAIN LIGHT THROUGH FRIDAY AFTERNOON. BY 00Z SATURDAY THE
MODELS ARE IN GENERALLY GOOD AGREEMENT HAVING THE WARM FRONT NEAR
THE IA MO BORDER AS AN H850 LOW APPROACHES WITH ANOTHER PUSH OF
STRONGER THETAE ADVECTION...H850 WINDS TO 25KT INCREASING TO 40KTS
BY 06Z OVER THE SOUTH. WITH THE STRONG FORCING AND BOUNDARY ALOFT...
THERE IS AN INCREASING CHANCE FOR AN MCS TO FORM OVER NORTHWEST MO
AND LIFT EAST NORTHEAST INTO SOUTHERN IOWA THROUGH THE NIGHT. BUFKIT
SOUNDINGS OVER SOUTHERN IOWA INDICATE SATURATION FROM H800 TO H300.
PRECIPITABLE WATER VALUES INCREASE TO 2 TO 2.25 INCHES BY 06-12Z
SATURDAY OVER SOUTHERN IOWA. AS WELL...WARM CLOUD DEPTHS TO 14 TO
15KFT DURING THIS TIME. THIS SHOULD PROMOTE VERY EFFICIENT RAINFALL
ACROSS THE BOUNDARY WITH ELEVATED CONVECTION. WITH INSTABILITY
VALUES DECREASING OVERNIGHT... THE MAIN CONCERN WILL BE HEAVY
RAINFALL. WITH THE FORECAST PARAMETERS...THERE IS A POTENTIAL FOR 2
TO +3 INCH TOTALS WITH ANY MCS THAT DEVELOPS. WILL CONTINUE TO
REFINE DETAILS OVER THE NEXT SEVERAL PACKAGES. AS THE CONVECTION
PULLS EAST SATURDAY MORNING THE UPPER LEVEL LOW WILL SLOWLY DRIFT
EAST. THIS WILL KEEP SHOWERS AND SCT THUNDER IN THE FORECAST FOR
SATURDAY. HIGHS FRIDAY WILL BE IN THE 70S TO LOWER 80S WITH THE
COOLER READINGS OVER THE NORTH. SATURDAY WILL SEE A MORE UNIFORM DAY
WITH MOST AREAS NEAR 80 FOR THE AFTERNOON AS CLOUD COVER AND THE
CHANCE FOR RAIN HOLDS. DEW POINTS WILL BE CLIMBING OVER THE NEXT
SEVERAL DAYS...WITH MORE UNCOMFORTABLE CONDITIONS EXPECTED. THE
SHOWER AND THUNDERSTORM POTENTIAL WILL LAST INTO SUNDAY AS THE UPPER
LEVEL SYSTEM PULLS EAST OF THE REGION. ON MONDAY THE AREA SHOULD BE
IN BETWEEN SYSTEMS WITH LITTLE CHANCE FOR ANY RAIN CENTRAL...SLIGHT
CHANCES EAST AND WEST. THE NEXT NORTHERN STREAM WAVE RETURNS FOR
MONDAY NIGHT AND TUESDAY WITH ANOTHER WARM FRONT ADVANCING EAST
ACROSS THE REGION. THIS SHOULD BRING AN ADDITIONAL CHANCE FOR SOME
THUNDERSTORMS MONDAY NIGHT AND TUESDAY WITH WARMER TEMPERATURES FOR
WEDNESDAY. IN FACT...H850 TEMPS ARE EXPECTED TO INCREASE TO 20C BY
WEDNESDAY WITH HIGHS IN THE MID 80S AND DEW POINTS BACK NEAR 70.
&&
.AVIATION...14/18Z
ISSUED AT 1229 PM CDT THU AUG 14 2014
VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD. WIDELY
SCATTERED SHRA/TSRA ARE EXPECTED TO DEVELOP ON FRIDAY...MAINLY
AFTER 12Z...WITH ASSOCIATED LOCALIZED MVFR OR LOWER CONDITIONS
POSSIBLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...REV
AVIATION...LEE
AREA FORECAST DISCUSSION
NWS PADUCAH KY
205 PM CDT Thu Aug 14 2014
.UPDATE...
Issued at 201 PM CDT THU AUG 14 2014
For aviation section only.
UPDATE Issued at 630 am CDT THU AUG 14 2014
Updated for aviation forecast discussion.
&&
.SHORT TERM...(Today through Saturday)
Issued at 229 AM CDT THU AUG 14 2014
High pressure was centered over the region during the overnight
hours, with a frontal boundary draped across parts of IA, IL, IN and
into OH. Models have been advertising this back door cold front for
several days now. It will continue to sag southwest toward the area
today. A band of mid clouds is seen on satellite and METAR
observations/radar indicate that some spotty showers are resulting
from these clouds. The frontal boundary should reach parts of
southern IL and southwest IN by afternoon or early evening.
Models differ on whether precipitation develops into our CWA
however. The 00Z NAM and latest RUC keep the QPF just north of us,
while the GFS indicate a very small sliver of our northernmost
counties have a chance of seeing a few showers. Some of the hi res
models (ARW/NMM) show a band of spotty showers dropping into parts
of southern IL, southwest IN and parts of KY during the late
afternoon hours. Might opt to throw in some light showers or
sprinkles up in the far north since there may be just enough low
level moisture to bring a few drops to the ground. Will wait and see
what surrounding offices want to do.
Temperatures today should be in the lower to mid 80s, similar to
what occurred yesterday. However, it might be a bit warmer in parts
of SEMO today since winds will become more southerly there.
Whatever precipitation does occur later today should be short lived
as the front disintegrates and high pressure tries to build in behind
it tonight. On Friday, moisture begins to increase which will mean
an increase in cloudiness. Meanwhile, mid/upper heights will begin
rising by late in the week and into weekend, which will mean a bump
in temperatures. Sfc winds will also eventually shift around to the
south as well. We should see upper 80s area wide on Friday and
Saturday.
Next item of business is watching how a mid level short wave moves
across the top of a prominent ridge across the mid CONUS. It is
slated to drop southeast toward the area Friday night into Saturday.
We believe Friday night should be mainly dry but chances for rain
will have to be maintained at least in our northwestern sections for
Saturday. However, the better chances look to arrive Saturday night.
.LONG TERM...(Sunday through Wednesday)
Issued at 229 AM CDT THU AUG 14 2014
A blend of the 00z/12z GFS/GEFS and 12z ECENS was used for this
forecast. This resulted in little change to the inherited PoPs and
resultant temperatures. Temperatures will be geared toward MOS and
CONUS raw model output.
Slow moving upper trof is forecast to approach the CWFA Saturday
night and slowly progress ESE across the region through Sunday
night. Will carry good chance PoPs for convection as a result given
the respectable moisture coupled with mid trop forcing that will
accompany the upper system.
The system will head on to the east Monday. Will linger chance PoPs
over the east, and taper them off west. We may see a lull Monday
night as weak s/wv ridging moves overhead. Inherited 20% values and
see no reason to drop them yet, until a more clear signal is
established.
As some deamplification of the pattern occurs, the WNW flow pattern
across the area will weaken. We will be in broad SSW surface slow as
broad low pressure develops over the plains. Little to key in on
feature wise. The models continue to develop QPF over the region in
what should be a weak but unsettled mid trop flow pattern. Therefore
will carry low chance PoPs during the day Tue/Wed, and taper them
off to slight chances at night.
&&
.AVIATION...
Issued at 201 PM CDT WED AUG 13 2014
Could see some MVFR fog development again on Friday morning.
Otherwise, high pressure will bring generally clear skies and
light winds through the TAF period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
130 PM EDT THU AUG 14 2014
.SYNOPSIS...
AFTER A FEW SHOWERS OR SPRINKLES TODAY...DRY AND COOL CONDITIONS
CAN BE EXPECTED INTO SATURDAY. THE NEXT WEATHER SYSTEM WILL AFFECT
US SUNDAY AS AN UPPER DISTURBANCE PASSES.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOWER MID LEVEL HEIGHTS CONTINUE TO ENCOMPASS THE AREA WHILE
TRIGGER TEMPERATURES HAVE BEEN ATTAINED OVER MUCH OF THE REGION
ALLOWING CU TO FORM. REGIONAL RADAR MOSAIC AS OF 15Z REMAINS QUIET
AND BASED ON LATEST HRRR SCALED ISOLD SHOWER MENTION BACK TO THE
FAR NORTHERN SECTIONS /N OF I-80/. TEMPS ON TRACK WITH READINGS
NEARLY 10 DEGREES BELOW NORMAL.
HIGH PRESSURE BUILDS INTO THE AREA TONIGHT ALLOWING FOR A
COOL NIGHT. THE ONLY FLY IN THE OINTMENT WOULD BE A POCKET OF LLVL
RH ILLUSTRATED BY NAM MODEL THAT DROPS S FORM LAKE ERIE INTO THE
MTNS DURING THE OVERNIGHT HOURS. FOR NOW...INCREASED SKY COVER FOR
PA COUNTIES...BUT THIS MAY NEED TO BE ADJUSTED AFTER FULL SUITE
OF 12Z MODELS ARRIVE.
RECORD LOWS FOR PIT/MGW/ZZV APPEAR SAFE TONIGHT WITH READINGS
IN THE UPPER 30S AND LOWER 40S.
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY/...
DRY AND A SLOW WARMING TREND FRIDAY AND SATURDAY AS HIGH PRESSURE
SLIDES EAST ACROSS THE REGION. NEXT UPPER LEVEL TROUGH APPROACHES
LATER SATURDAY NIGHT INTO SUNDAY WITH INCREASING LOW LEVEL
MOISTURE AND CHANCE POPS FOR SHOWERS AND THUNDERSTORMS.
TEMPERATURES WILL WARM TO NEAR SEASONAL AVERAGE BY SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
GENL ZONAL FLOW IS PROGGED TO SET UP ACRS THE RGN THRU THE PD. MDLS
CONT TRENDING TWD SVRL CROSSING SHRTWVS EMBEDDED IN THE FLOW...AND
AS A RESULT INCLUDED CHC POPS FOR SHWRS/TSTMS THRU MUCH OF THE PD.
DETAILS WL DEPEND ON SPECIFIC SFC BNDRY PLACEMENT AND TIMING OF
SHRTWVS. TEMPS SHOULD AVG NR SEASONAL LVLS.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
MAINLY JUST SCATTERED CLOUDS ACROSS REGION. NORTHWEST WINDS WILL BE
GUSTY AT TIMES TILL SUNSET. OTHERWISE CLEAR INTO FRIDAY.
OUTLOOK...RESTRICTIONS ARE POSSIBLE SUNDAY IN SHOWERS AND
THUNDERSTORMS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1212 PM CDT THU AUG 14 2014
.UPDATE...
ISSUED AT 958 AM CDT THU AUG 14 2014
UPDATED FORECAST TO INCREASE CLOUD COVER A BIT BASED ON RECENT
SATELLITE TRENDS. ALSO CONSIDERED A SLIGHT CHANCE OF SHOWERS TO
THE FAR NORTHERN FORECAST AREA AS A CLUSTER OF CONVECTION
CONTINUES TO MOVE THROUGH EASTERN SOUTH DAKOTA. RADAR TRENDS
SUGGEST PRECIP IS HAVING A HARD TIME PUSHING SOUTHEAST. LATEST
RUNS OF THE RAP MODEL ALSO KEEP RAIN OUT OF THE FORECAST AREA AND
THIS SEEMS REASONABLE. WILL CONTINUE TO MONITOR TO SEE IF ANYTHING
MIGHT DEVELOP THERE THROUGH PEAK HEATING...BASED ON 12Z NAM.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 316 AM CDT THU AUG 14 2014
MAIN FORECAST CONCERN IS TIMING/CHANCES OF PCPN THROUGH THE WEEKEND.
UPPER RIDGE AXIS CONTINUES TO MOVE EAST...EXTENDING FROM WESTERN
TEXAS NORTHWARD INTO WESTERN NEB AND THE WESTERN DAKOTAS.
SATELLITE IMAGERY SHOWS UPPER SHORTWAVE TROUGH MOVING NORTHEAST
NEAR THE FOUR CORNERS REGION AND THIS WILL CONTINUE TO RIDE UP THE
THE RIDGE AND INTO WESTERN SD/NEB BY 00Z TONIGHT. AT THE
SURFACE...A LARGE RIDGE OF HIGH PRESSURE EXTENDING ACROSS THE
MIDWEST WILL CONTINUE TO SLOWLY MOVE EAST BRINGING PREVAILING
SOUTHEASTERLY SFC FLOW OVER MUCH OF THE CENTRAL PLAINS TODAY. IN
ADDITION...AN ELONGATED REGION OF LEE SIDE LOW PRESSURE EXTENDS
ACROSS THE HIGH PLAINS AHEAD OF THE APPROACHING SHORTWAVE TROUGH.
AS THE UPPER SHORTWAVE TOPS THE RIDGE...THE LEE SIDE LOW WILL ALSO
ADVANCE EAST...SLIDING INTO CENTRAL NEB BY FRIDAY MORNING.
INCREASING ISENTROPIC UPGLIDE AHEAD OF THIS COULD PRODUCE A FEW
SHOWERS AND ISOLATED THUNDERSTORMS...ESPECIALLY WITH A
STRENGTHENING SOUTHWESTERLY LOW LEVEL JET. WE MAY JUST SEE AN
INCREASE OF MID CLOUDS/ACCAS. SPOTTY SHOWERS LOOK MORE PROBABLE
BY FRIDAY AFTERNOON AND EVENING IN ADVANCE OF THE APPROACHING
SHORTWAVE. ONCE THE WAVE IS OVERHEAD IN EASTERN NEBRASKA...IT WILL
DEEPEN AND CLOSE OFF AS IT MOVES INTO NORTHERN MISSOURI. PLACEMENT
AND TIMING OF THIS FEATURE HAS BECOME MORE CONSISTENT IN VARIOUS
MODEL SOLUTIONS SO FORECAST CONFIDENCE IS INCREASING. BY 12Z
SATURDAY...THE UPPER WAVE IS PROGGED TO MOVE OVER NORTHEAST
NEBRASKA WITH THE ASSOCIATED SFC LOW CENTERED SOMEWHERE OVER
EASTERN NEBRASKA. HEAVIER PCPN IS LIKELY ALONG THE WARM FRONT
WHICH SHOULD EXTEND INTO WESTERN IOWA SO HAVE INCREASED POPS IN
SERN NEB AND SWRN IA. AS THE SYSTEM MOVES INTO NORTHERN MISSOURI
SATURDAY AFTERNOON...WE SHOULD SEE LINGERING SHOWERS ON THE
BACKSIDE OF THE SYSTEM ALONG WITH CLOUD COVER AND COOLER TEMPS.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 AM CDT THU AUG 14 2014
THERE REMAINS A CHANCE OF PCPN IN NEARLY EVERY FORECAST PERIOD IN
THE EXTENDED AS ADDITIONAL PIECES OF SHORTWAVE ENERGY MOVE ACROSS
THE FLATTENED UPPER LEVEL FLOW. TIMING OF THESE FEATURES IS PRETTY
TOUGH THIS FAR OUT...BUT CANNOT RULE OUT ANY ONE GIVEN PERIOD.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1210 PM CDT THU AUG 14 2014
VFR CONDITIONS THROUGH THE PERIOD WITH SOUTHEASTERLY WINDS AND
MID CLOUDS. COULD SEE A 30 PERCENT CHANCE OF SHOWERS AT KOFK
09-12Z AND KOMA 14-18Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
UPDATE...DEWALD
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
945 AM PDT THU AUG 14 2014
.SYNOPSIS...DRIER AIR ARRIVING FROM THE WEST WILL LIMIT THUNDERSTORM
CHANCES MAINLY TO MOHAVE COUNTY TODAY. DRY WEATHER WILL OCCUR
THROUGH THE WEEKEND AND INTO NEXT WEEK...WITH TEMPERATURES WARMING
TO NEAR NORMAL BY SATURDAY AND CLIMBING A FEW DEGREES ABOVE NORMAL
FOR NEXT WEEK.
&&
.UPDATE...MAY JUST BE ENOUGH MOISTURE/INSTABILITY THIS AFTERNOON FOR
A BRIEF SHOWER OR THUNDERSTORM OVER THE HIGHER TERRAIN OF FAR
SOUTHERN CLARK COUNTY. INCREASED POPS AROUND SEARCHLIGHT THIS
AFTERNOON.
OTHERWISE, HI RES MODELS AND HRRR SUGGEST BEST CONVECTIVE PARAMETERS
WILL BE ACROSS EASTERN LINCOLN COUNTY AND MOHAVE COUNTY TODAY.
MODELS STILL INDICATE AIR MASS WILL CONTINUE TO DAY/STABILIZE FROM
THE WEST FRIDAY AND BEYOND.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
THE SYNOPTIC PATTERN THIS MORNING FEATURES A CLOSED UPPER LOW OVER
THE PACIFIC NORTHWEST...RIDGING FROM TEXAS NORTHWARD INTO
CANADA...AND TROUGHING OVER THE EASTERN CONUS. THE UPPER LOW OVER
THE PACIFIC NORTHWEST WILL GRADUALLY SHIFT EAST THROUGH THE SHORT
TERM PERIOD. THIS WILL CONTINUE TO DISPLACE THE RIDGE FARTHER TO THE
SOUTH ALLOWING FOR DRY WEST-SOUTHWEST FLOW ALOFT TO REMAIN OVER OUR
AREA. THE DRYING TREND CONTINUES THIS MORNING FROM WEST TO EAST.
NEARLY ALL THE IPW SENSORS ARE SHOWING ROUGHLY A QUARTER TO SEVEN
TENTHS OF AN INCH OF MOISTURE LOSS OVER THE LAST 24 HOURS...AS OF
THIS WRITING.
THE DRYING WILL LIMIT ANY THUNDERSTORM THREAT TO MOHAVE COUNTY AND
PORTIONS OF FAR EASTERN LINCOLN COUNTY THIS AFTERNOON AND EARLY
EVENING. FOR FRIDAY AND SATURDAY...THE ENTIRE FORECAST AREA IS
LOOKING DRY. SHOULD SEE SOME CUMULUS CLOUDS OVER THE HIGHER TERRAIN
OF MOHAVE COUNTY BUT LACK OF DEEP MOISTURE AND ADEQUATE FORCING WILL
MEAN NO CHANCE OF RAIN. HIGH TEMPERATURES WILL WARM BACK CLOSER TO
NORMAL AS WE HEAD INTO THE WEEKEND AND SOUTHERLY BREEZES WILL BE
COMMON EACH AFTERNOON.
.LONG TERM...SUNDAY THROUGH THURSDAY...AN EXTENDED DRY PERIOD LOOKS
PROBABLE FOR THE ENTIRE REGION LASTING WELL INTO NEXT WEEK. FLAT
HIGH PRESSURE RIDGE WITH TROUGHING OFF THE COAST OF NORTHERN
CALIFORNIA WILL RESULT IN MONSOON MOISTURE SHUNTED SOUTHWARD WHILE A
DRY SOUTHWESTERLY FLOW IS ADVECTED INTO THE MOJAVE DESERT AND
SOUTHERN GREAT BASIN. THIS IS NOT A FAVORABLE PATTERN FOR OUR
MONSOON LOVERS OUT THERE...IN FACT WE WILL BE LUCKY TO EVEN SEE AN
ISOLATED STORM IN THE HIGHEST PEAKS OF MOHAVE COUNTY NEXT WEEK.
KEPT THE FORECAST DRY FOR THE ENTIRE REGION IN THE EXTENDED TIME
FRAME...HOWEVER, GIVEN THE TIME OF YEAR, WE WILL NEED TO WATCH THE
MARGINAL MOISTURE AROUND FOR THE POSSIBILITY OF ISOLATED ACTIVITY IN
MOHAVE COUNTY.
WITH THE DRY CONDITIONS FORECAST...TEMPERATURES WILL HAVE NO TROUBLE
CLIMBING ABOVE NORMAL AND I TRENDED THE TEMPERATURES UPWARDS FOR
NEXT WEEK...AND A FEW DEGREES ABOVE GUIDANCE. TEMPERATURES SUNDAY
ONWARD WILL AVERAGE 3 TO 5 DEGREES ABOVE THE SEASONAL AVERAGE.
&&
.AVIATION...FOR MCCARRAN...ENOUGH MOISTURE WILL REMAIN IN PLACE FOR
CUMULUS DEVELOPMENT OVER THE MOUNTAINS THIS AFTERNOON...BUT NOT
EXPECTING ENOUGH DEVELOPMENT FOR RAIN. SOUTHERLY WINDS THIS MORNING
ARE EXPECTED TO CONTINUE WITH SOME GUSTS TO AROUND 20-25 KNOTS THIS
AFTERNOON. GUSTS WILL DIMINISH...BUT SOUTHERLY WINDS WILL CONTINUE
OVERNIGHT AND INTO FRIDAY MORNING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCATTERED CUMULUS ARE EXPECTED AGAIN TODAY WITH A
SLIGHT CHANCE OF THUNDERSTORMS OVER LINCOLN/MOHAVE COUNTIES. WINDS
WILL FAVOR TYPICAL DIURNAL WIND PATTERNS WITH GUSTS TO AROUND 20-25
KNOTS THIS AFTERNOON.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION IS NOT EXPECTED
THROUGH AT LEAST THE EARLY PART OF NEXT WEEK.
&&
$$
UPDATE...PIERCE
SHORT TERM/AVIATION...PADDOCK
LONG TERM...OUTLER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
353 PM EDT THU AUG 14 2014 305
.SYNOPSIS...A DRY CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE MID-
ATLANTIC AND CAROLINAS THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM THURSDAY...
OVERVIEW: CYCLONIC FLOW ALOFT WILL DOMINATE THE UPPER LEVEL PATTERN
ACROSS CENTRAL NC THROUGH TONIGHT...ON THE SOUTHERN PERIPHERY OF AN
UNSEASONABLY DEEP UPPER LEVEL LOW STALLED IN VICINITY OF THE LOWER
GREAT LAKES/SOUTHERN QUEBEC. 14Z WV IMAGERY AND RAP DATA INDICATED A
POTENT SHORTWAVE UPSTREAM OVER IL/IN THIS MORNING. THIS FEATURE IS
PROGGED TO TRACK SE THROUGH KY EARLY THIS AFTERNOON...THEN EASTWARD
THROUGH SOUTHERN WV INTO SOUTHERN VA BY 00Z. DPVA ASSOC/W THE WAVE
WILL RESULT IN WEAK HEIGHT/SLP FALLS OVER THE REGION...WITH LOW-
LEVEL FLOW GRADUALLY VEERING FROM N/NE THIS MORNING TO SW/WSW THIS
AFTERNOON. THE AIRMASS OVER CENTRAL NC THIS MORNING IS UNSEASONABLY
DRY (PWAT 0.71" PER 12Z GSO RAOB)...A RESULT OF MID-LEVEL SUBSIDENCE
AND LOW-LEVEL COLD ADVECTION IN THE WAKE OF THE COLD FRONTAL PASSAGE
EARLY YESTERDAY. SFC DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S AT
14Z...AND ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOWER/MID 50S
VIA THIS AFTERNOON IN ASSOC/W DIURNAL HEATING/MIXING.
PRECIP/TEMPS: DIURNAL HEATING WILL BE INSUFFICIENT TO DESTABILIZE
THE ATMOSPHERE OVER CENTRAL NC THIS AFT/EVE GIVEN A VERY DRY
BOUNDARY LAYER AND LITTLE IF ANY MOISTURE ADVECTION/RECOVERY...EVEN
AS FLOW VEERS TO THE SW/WSW. AS A RESULT...THE POTENT SHORTWAVE
ENERGY TRACKING THROUGH SOUTHERN WV/VA LATE THIS AFT/EVE SHOULD
YIELD LITTLE MORE THAN SCATTERED UPPER LEVEL CLOUD COVER...THOUGH
ISOLD SHOWER ACTIVITY COULD BE POSSIBLE TO THE NORTH IN WV/VA.
EXPECT HIGHS BELOW NORMAL IN THE LOWER 80S NW TO MID/UPPER 80S SOUTH
AND SE OF THE TRIANGLE. LOWS TONIGHT SIMILAR TO LAST NIGHT ALBEIT A
LITTLE WARMER DUE TO AIRMASS MODIFICATION TODAY...IN THE LOWER 60S
EARLY FRI MORNING. -VINCENT
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 255 PM THURSDAY...
OVERVIEW: CYCLONIC FLOW ALOFT WILL PERSIST OVER THE EAST COAST STATES
FRI INTO FRI NIGHT...ON THE SOUTHERN PERIPHERY OF AN UNSEASONABLY DEEP
UPPER LEVEL LOW STALLED OUT OVER SOUTHERN QUEBEC. AS THE UPPER LEVEL
TROUGH AXIS SHIFTS CLOSER TO THE COAST...WESTERLY FLOW ALOFT WILL GIVE
WAY TO NW FLOW ALOFT OVER THE CAROLINAS. A SECONDARY COLD FRONT WILL
APPROACH CENTRAL NC FROM THE NORTH TONIGHT BEFORE STALLING OUT WEST-
EAST IN VICINITY OF THE VA/NC BORDER ON FRIDAY. HEIGHT RISES ALOFT WILL
RESULT IN WEAK PRESSURE RISES OVER THE REGION FRI AS THE STALLED UPPER
LEVEL LOW IN QUEBEC WOBBLES NORTHWARD...THOUGH EPISODIC DPVA ASSOC/W
POTENT SHORTWAVE ENERGY DIGGING SOUTHEAST FROM CANADA THROUGH THE OH
VALLEY INTO THE CAROLINAS IN NW FLOW ALOFT WILL ALLOW FOR TROUGHING AT
TIMES.
CONVECTION: THE SECONDARY FRONT WILL STALL OUT ALONG OR NEAR THE VA
BORDER ON FRIDAY AS LOW-LEVEL FLOW (I.E. 925 MB) VEERS TO THE SSW/SW
AND ALLOWS MOISTURE RETURN...ESP IN CENTRAL/EASTERN NC. THE
COMBINATION OF DIURNAL HEATING AND INCREASED BOUNDARY LAYER MOISTURE
SHOULD ALLOW MARGINAL DESTABILIZATION FRI AFT/EVE...WITH MLCAPE VALUES
AS HIGH AS 1000-1500 J/KG SOUTH AND EAST OF THE TRIANGLE AND UP TO 500
J/KG IN THE NW PIEDMONT ACCORDING TO THE NAM...THOUGH THE GFS IS
NOTABLY MORE STABLE AND CAPPED. GIVEN EPISODIC DPVA IN THE PRESENCE OF
SOME DEGREE OF MOISTURE RETURN AND DESTABILIZATION...WILL INTRODUCE A
SLIGHT CHANCE OF CONVECTION DURING THE LATE AFTERNOON AND EVENING
HOURS. IF FOCUSED DPVA OCCURS AROUND OR SHORTLY AFTER PEAK HEATING IN
THE PRESENCE OF `NAM-LIKE` THERMO PROFILES WHEN 0-6 KM SHEAR IS PROGGED
AT 35-45 KT...A CONDITIONAL POTENTIAL FOR AN ISOLD SEVERE STORM WOULD
BE PRESENT. SUFFICIENT UNCERTAINTY IS PRESENT TO PRECLUDE ANY MENTION
OF HAZARDOUS WEATHER AT THIS TIME.
TEMPS: EXPECT HIGHS FRIDAY SLIGHTLY BELOW NORMAL IN THE MID/UPPER
80S...WITH LOWS FRI NIGHT IN THE 60S. -VINCENT
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 310 PM THURSDAY...
THE UPPER AIR PATTERN DURING THE LONG RANGE EVOLVES FROM A NORTHEAST
CONUS TROUGH AND A DESERT SOUTHWEST RIDGE OVER THE WEEKEND TO A FLATTER
AND MORE ZONAL PATTERN BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN
A WARMING OF TEMPERATURES WITH SMALL CHANCES OF PRECIPITATION MAINLY
DURING THE EARLY TO MID PORTION OF NEXT WEEK.
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THE NORTHWEST FLOW PRESENT AT
THE START OF THE PERIOD SATURDAY AND THE ASSOCIATED LEE TROUGHING WILL
DAMPEN BY LATE SUNDAY. THE NAM/GFS/ECMWF INDICATE THAT SOME SCATTERED
CONVECTIVE PRECIPITATION IS POSSIBLE IN THE COASTAL PLAIN OR COASTAL
REGION DURING THE AFTN/EVENING. AROUND A THIRD OF THE SREF MEMBERS AT
FAY/RWI/RDU INDICATE SOME LIGHT PRECIPITATION WITH THE PRECIPITATION
GENERATED BY THE ARW MEMBERS FOR THE MOST PART ACROSS THESE LOCATIONS.
MOS GUIDANCE POPS ARE LOW AND GENERALLY RANGE LESS THAN 15%. GIVEN
THIS...HAVE OPTED TO INSERT A NARROW CORRIDOR OF SLIGHT CHANCE POPS FOR
SAT AFTERNOON IN THE COASTAL PLAIN BUT WILL HOLD OFF GOING ANY MORE
BULLISH. A SIMILAR SETUP OCCURS ON SUNDAY BUT GIVEN THE MORE WESTERLY
FLOW AND LOW CONFIDENCE WILL KEEP SUNDAY DRY FOR NOW. HIGHS WILL RANGE
IN THE UPPER 80S NORTH TO LOWER 90S SOUTH ON SAT AND A DEGREE OR TWO
WARMER ON SUN WITH MORNING LOWS IN THE UPPER 60S TO LOWER 70S.
STILL A FAIR AMOUNT OF UNCERTAINTY WITH THE PATTERN FOR NEXT WEEK AS A
COLD FRONT DROPS INTO THE MID ATLANTIC STATES AND BECOMES STATIONARY AS
A WEAK SURFACE LOW DEVELOPS OVER THE WESTERN OH VALLEY AND SLOWLY MOVES
EAST. GFS/ECMWF GUIDANCE DIFFERS QUITE A BIT ON THE EVOLUTION AND
EASTWARD PROGRESSION OF THIS SYSTEM. LATEST GUIDANCE FROM HPC LEANS
TOWARD THE ECMWF AND THE EC ENSEMBLE WHICH HAS BEEN MORE STABLE AND TO
WHICH THE GFS IS TRENDING. THE RESULT WILL BE AN INCREASE IN THE THREAT
OF MAINLY DIURNALLY FORCED CONVECTION DURING THE UPCOMING WORK WEEK
WITH PERHAPS THE BEST COVERAGE ON MONDAY AND TUESDAY. THICKNESS VALUES
INCREASE A BIT THROUGH THE PERIOD...WITH THE 1000-850 MB THICKNESS
REACHING THE 1430S BY THURSDAY. THIS WIL RESULT IN AN INCREASE IN MAX
TEMPS TO NEAR OR JUST ABOVE AVERAGE WITH HIGHS IN THE UPPER 80S TO
LOWER 90S. INCREASING MOISTURE WILL RESULT IN OVERNIGHT LOWS MODERATING
INTO THE LOWER 70S BY MID WEEK. -BLAES
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 200 PM THURSDAY...
24-HR TAF PERIOD: HIGH CONFIDENCE IN VFR CONDITIONS AND LIGHT WINDS
THROUGH THE TAF PERIOD IN ASSOC/W A DRY AND STABLE AIRMASS OVER THE
REGION. A SMALL POTENTIAL FOR ISOLD CONVECTION CANNOT BE RULED OUT LATE
FRI AFTERNOON AND EVENING.
LOOKING AHEAD: VFR CONDITIONS WILL PREVAIL THROUGH THE WEEKEND...THOUGH
WITH AN INCREASING POTENTIAL FOR AFTERNOON AND EVENING CONVECTION LATE
THIS WEEKEND THROUGH EARLY NEXT WEEK. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...BLAES
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
310 PM EDT THU AUG 14 2014 305
.SYNOPSIS...A DRY CYCLONIC FLOW ALOFT WILL PREVAIL OVER THE MID-
ATLANTIC AND CAROLINAS THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH FRIDAY NIGHT/...
AS OF 1030 AM THURSDAY...
TODAY/TONIGHT OVERVIEW: CYCLONIC FLOW ALOFT WILL DOMINATE THE UPPER
LEVEL PATTERN ACROSS CENTRAL NC THROUGH TONIGHT...ON THE SOUTHERN
PERIPHERY OF AN UNSEASONABLY DEEP UPPER LEVEL LOW STALLED IN VICINITY
OF THE LOWER GREAT LAKES/SOUTHERN QUEBEC. 14Z WV IMAGERY AND RAP DATA
INDICATED A POTENT SHORTWAVE UPSTREAM OVER IL/IN THIS MORNING. THIS
FEATURE IS PROGGED TO TRACK SE THROUGH KY EARLY THIS AFTERNOON...THEN
EASTWARD THROUGH SOUTHERN WV INTO SOUTHERN VA BY 00Z. DPVA ASSOC/W THE
WAVE WILL RESULT IN WEAK HEIGHT/SLP FALLS OVER THE REGION...WITH LOW-
LEVEL FLOW GRADUALLY VEERING FROM N/NE THIS MORNING TO SW/WSW THIS
AFTERNOON. THE AIRMASS OVER CENTRAL NC THIS MORNING IS UNSEASONABLY DRY
(PWAT 0.71" PER 12Z GSO RAOB)...A RESULT OF MID-LEVEL SUBSIDENCE AND
LOW-LEVEL COLD ADVECTION IN THE WAKE OF THE COLD FRONTAL PASSAGE EARLY
YESTERDAY. SFC DEWPOINTS WERE IN THE UPPER 50S TO LOWER 60S AT
14Z...AND ARE EXPECTED TO FALL INTO THE UPPER 40S TO LOWER/MID 50S VIA
THIS AFTERNOON IN ASSOC/W DIURNAL HEATING/MIXING.
TODAY/TONIGHT FORECAST: DIURNAL HEATING WILL BE INSUFFICIENT TO
DESTABILIZE THE ATMOSPHERE OVER CENTRAL NC THIS AFT/EVE GIVEN A VERY
DRY BOUNDARY LAYER AND LITTLE IF ANY MOISTURE ADVECTION/RECOVERY...EVEN
AS FLOW VEERS TO THE SW/WSW. AS A RESULT...THE POTENT SHORTWAVE ENERGY
TRACKING THROUGH SOUTHERN WV/VA LATE THIS AFT/EVE SHOULD YIELD LITTLE
MORE THAN SCATTERED UPPER LEVEL CLOUD COVER. EXPECT HIGHS BELOW NORMAL
IN THE LOWER 80S NW TO MID/UPPER 80S SOUTH AND SE OF THE TRIANGLE. LOWS
TONIGHT SIMILAR TO LAST NIGHT ALBEIT A LITTLE WARMER DUE TO AIRMASS
MODIFICATION TODAY...IN THE LOWER 60S EARLY FRI MORNING. -VINCENT
FOR FRI/FRI NIGHT: THE AFOREMENTIONED E-W ORIENTED SECONDARY FRONT
LOOKS LIKELY TO STALL OUT JUST NORTH OF THE NC/VA BORDER FRI AS A
WEAK TROUGH FORMS OVER THE PIEDMONT. PW IS PREDICTED TO STEADILY
INCREASE LATE IN THE DAY THROUGH EVENING TO AT OR ABOVE 1.5" FROM
THE TRIANGLE EAST AND SE... ALONG AND AHEAD OF THE WEAK PIEDMONT
TROUGH. THE NAM/GFS BOTH SHOW WEAK LOW PRESSURE FORMING FRI EVENING
OVER THE NE PIEDMONT... AND THIS SUBTLE MASS CONVERGENCE JUST SOUTH
OF THE BACKDOOR FRONT COMBINED WITH INCREASING MOISTURE AND
IMPROVING (BUT STILL MODEST) INSTABILITY (MLCAPE RISING TO 500-1500
J/KG) IN THIS AREA MAY SUPPORT ISOLATED SHOWERS AND PERHAPS A STORM
OVER THE NORTHEAST QUARTER OF THE CWA. LOTS OF UNCERTAINTY HOWEVER
WITH A LACK OF MID-UPPER SUPPORT FOR POPS... SO WILL RAISE POPS TO
10-14% FOR NOW... AND CONTINUE TO MONITOR FOR POSSIBLE INCLUSION OF
A SLIGHT CHANCE OF SHOWERS/STORMS IN LATER FORECASTS. IN ANY CASE...
DO EXPECT AN INCREASE IN CLOUDS TO PARTLY CLOUDY LATE FRI THROUGH
FRI NIGHT... ESPECIALLY IN THE NE CWA. SHOULD SEE NEAR NORMAL HIGHS
OF 86-90... WITH LOWS INCHING BACK UP TOWARD NORMAL.. 63-68. -GIH
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 240 AM THURSDAY...
CENTRAL NC IS IN FOR A WARM AND DRY WEEKEND FOR A CHANGE AS A ZONAL
UPPER LEVEL PATTERN COINCIDES WITH RELATIVE HIGH PRESSURE AT THE
SURFACE ON THE BACK SIDE OF THE BERMUDA HIGH WHICH WILL USHER IN THE
RETURN FLOW RESPONSIBLE FOR THE WARMER TEMPERATURES. MODEL THICKNESS
VALUES SOAR AS HIGH AS THE 1420S ON THE MORE AGGRESSIVE GFS
SUGGESTING HIGHS IN THE LOWER 90S BUT SOME POSSIBLE SHORTWAVE
INDUCED CLOUDINESS COULD KEEPS TEMPERATURES DOWN A LITTLE AS
SUGGESTED BY ADJUSTED MOS GUIDANCE. WILL GO WITH UPPER 80S TO LOWER
90S NORTHWEST TO SOUTHEAST WITH SUNDAY BEING THE WARMER DAY OUT OF
THE TWO. LOWS IN THE MID 60S TO LOWER 70S. LIGHT WINDS OUT OF THE
SOUTH LESS THAN 5 KTS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 310 PM THURSDAY...
THE UPPER AIR PATTERN DURING THE LONG RANGE EVOLVES FROM A
NORTHEAST CONUS TROUGH AND A DESERT SOUTHWEST RIDGE OVER THE
WEEKEND TO A FLATTER AND MORE ZONAL PATTERN BY THE MIDDLE OF NEXT
WEEK. THIS WILL RESULT IN A WARMING OF TEMPERATURES WITH SMALL
CHANCES OF PRECIPITATION MAINLY DURING THE EARLY TO MID PORTION
OF NEXT WEEK.
MODEL GUIDANCE IS IN GOOD AGREEMENT THAT THE NORTHWEST FLOW PRESENT
AT THE START OF THE PERIOD SATURDAY AND THE ASSOCIATED LEE TROUGHING
WILL DAMPEN BY LATE SUNDAY. THE NAM/GFS/ECMWF INDICATE THAT SOME
SCATTERED CONVECTIVE PRECIPITATION IS POSSIBLE IN THE COASTAL PLAIN
OR COASTAL REGION DURING THE AFTN/EVENING. AROUND A THIRD OF THE SREF
MEMBERS AT FAY/RWI/RDU INDICATE SOME LIGHT PRECIPITATION WITH THE
PRECIPITATION GENERATED BY THE ARW MEMBERS FOR THE MOST PART ACROSS
THESE LOCATIONS. MOS GUIDANCE POPS ARE LOW AND GENERALLY RANGE LESS
THAN 15%. GIVEN THIS...HAVE OPTED TO INSERT A NARROW CORRIDOR OF
SLIGHT CHANCE POPS FOR SAT AFTERNOON IN THE COASTAL PLAIN BUT WILL
HOLD OFF GOING ANY MORE BULLISH. A SIMILAR SETUP OCCURS ON SUNDAY
BUT GIVEN THE MORE WESTERLY FLOW AND LOW CONFIDENCE WILL KEEP SUNDAY
DRY FOR NOW. HIGHS WILL RANGE IN THE UPPER 80S NORTH TO LOWER 90S
SOUTH ON SAT AND A DEGREE OR TWO WARMER ON SUN WITH MORNING LOWS IN
THE UPPER 60S TO LOWER 70S.
STILL A FAIR AMOUNT OF UNCERTAINTY WITH THE PATTERN FOR NEXT WEEK AS
A COLD FRONT DROPS INTO THE MID ATLANTIC STATES AND BECOMES STATIONARY
AS A WEAK SURFACE LOW DEVELOPS OVER THE WESTERN OH VALLEY AND SLOWLY
MOVES EAST. GFS/ECMWF GUIDANCE DIFFERS QUITE A BIT ON THE EVOLUTION
AND EASTWARD PROGRESSION OF THIS SYSTEM. LATEST GUIDANCE FROM HPC
LEANS TOWARD THE ECMWF AND THE EC ENSEMBLE WHICH HAS BEEN MORE STABLE
AND TO WHICH THE GFS IS TRENDING. THE RESULT WILL BE AN INCREASE IN
THE THREAT OF MAINLY DIURNALLY FORCED CONVECTION DURING THE UPCOMING
WORK WEEK WITH PERHAPS THE BEST COVERAGE ON MONDAY AND TUESDAY.
THICKNESS VALUES INCREASE A BIT THROUGH THE PERIOD...WITH THE 1000-850
MB THICKNESS REACHING THE 1430S BY THURSDAY. THIS WIL RESULT IN AN
INCREASE IN MAX TEMPS TO NEAR OR JUST ABOVE AVERAGE WITH HIGHS IN
THE UPPER 80S TO LOWER 90S. INCREASING MOISTURE WILL RESULT IN
OVERNIGHT LOWS MODERATING INTO THE LOWER 70S BY MID WEEK. -BLAES
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 645 AM THURSDAY...
HIGH CONFIDENCE IN FAVORABLE VFR CONDITIONS TODAY THROUGH TONIGHT.
HIGH PRESSURE WILL CONTINUE TO BUILD INTO THE REGION FROM THE
WEST... RESULTING IN LIGHT SURFACE WINDS GENERALLY UNDER 8 KTS...
MAINLY FROM THE NW OR NORTH TODAY. ANY CLOUDS WILL BE MOST NUMEROUS
IN THE LATE AFTERNOON THROUGH TONIGHT WITH ANY BASES ABOVE 4000 FT
AGL. VERY LIGHT WINDS WILL BECOME MAINLY SOUTHWESTERLY TONIGHT AS A
WEAK SECONDARY BACKDOOR FRONT APPROACHES FROM THE NORTH LATE.
LOOKING BEYOND 12Z FRI MORNING... VFR CONDITIONS LIKELY TO DOMINATE
THROUGH AT LEAST SUNDAY NIGHT WITH DRY AIR IN PLACE. A POTENTIAL
STORM SYSTEM MAY APPROACH FROM THE WEST MONDAY... BRINGING A CHANCE
OF SUB-VFR CONDITIONS AND SHOWERS/STORMS. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT/HARTFIELD
SHORT TERM...ELLIS
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS MEDFORD OR
250 PM PDT THU AUG 14 2014
.DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER LOW CENTERED
ALONG THE OREGON/WASHINGTON BORDER. THERE`S PLENTY OF CLOUD COVER
OVER THE REGION, BUT SO FAR HAVE NOT SEEN ANY REPORTS OF MEASURABLE
PRECIPITATION. THE NAM AND THE GFS SHOW QPF BREAKING OUT EAST OF THE
CASCADES AND THE NAM SHOWS SOME IN NORTHERN CAL FROM THE SHASTA
TRINITY NORTHEAST TOWARDS LAKEVIEW. THE HRRR RADAR REFLECTIVITY WAS
ALSO SHOWING SPOTTY PRECIPITATION IN THE ABOVE MENTIONED AREAS
EARLIER THIS AFTERNOON, BUT IT HAS NOT VERIFIED. SO I HAVE LOW
CONFIDENCE IN THAT SOLUTION. BOTTOM LINE IS I DOUBT MUCH IF ANYTHING
WILL HAPPEN THIS FAR SOUTH FOR A FEW REASONS. FIRST, THE MODELS ARE
SHOWING SLIGHT WARMING ALOFT. SECOND, THE STRONGEST TRIGGER AND
COOLER AIR ALOFT WILL BE OVER THE NORTHEAST PART OF THE REGION.
THIRD, THE POSITION OF THE LOW IS NOT ONE THAT IS FAVORABLE FOR AN
OUTBREAK OF PRECIPITATION AND FINALLY THE MODEL SOUNDINGS SHOW A SUB
DRY LAYER, SO IF ANYTHING DEVELOPS, MOST WILL NOT REACH THE GROUND.
WITH THAT SAID, I COULD NOT RULE OUT A FEW LIGHT SHOWERS, BUT
PROBABLY NOT ANYTHING MEASURABLE. FURTHER NORTH IN NORTHERN LAKE AND
KLAMATH COUNTIES, EXPECT A FEW ISOLATED STORMS TO DEVELOP LATE THIS
AFTERNOON AND EARLY EVENING, THEN ENDING SHORTLY AFTER DARK.
THE UPPER LOW WILL CONTINUE TO SLOWLY MOVE NORTHEAST TONIGHT AND
CLOUD COVER WILL GRADUALLY DECREASE OVER MOST INLAND LOCATIONS.
TEMPERATURES EAST OF THE CASCADES WILL COOL DOWN INTO THE UPPER 30S
IN THE COOLER SPOTS IN NORTHERN KLAMATH COUNTY.
DRY AND MILDER WEATHER RETURNS FRIDAY AS THE UPPER LOW CONTINUE TO
SLOWLY MOVE NORTHEAST AND WEAK RIDGING BUILDS IN. TEMPERATURES WILL
REBOUND TO NEAR NORMAL VALUES ACROSS THE BOARD.
THIS RIDGING WILL BE SHORT LIVED. THE MODELS ARE ALL IN FAIRLY GOOD
AGREEMENT SHOWING ANOTHER, WEAK POSITIVE TILTED UPPER TROUGH
DEVELOPING OFF THE OREGON COAST SATURDAY AND REMAINING THERE THROUGH
SUNDAY WITH WEAK SHORTWAVES MOVING FROM SOUTHWEST TO NORTHEAST OVER
THE AREA. RIGHT NOW IT DOES NOT LOOK UNSTABLE ENOUGH FOR STORMS TO
DEVELOP SATURDAY. THE GFS DOES SHOW MID LEVEL MOISTURE INCREASING IN
THE AFTERNOON, BUT NOT ENOUGH TO BE A CONCERN, ESPECIALLY WITH
LITTLE OR NO TRIGGER. SUNDAY IS A DIFFERENT STORY. THE NAM SHOWS MID
LEVEL MOISTURE INCREASING OVER THE CASCADES AND WESTERN SISKIYOU
COUNTY IN THE AFTERNOON WITH NEGATIVE LI`S, INCREASING CAPE AND
STRONGER TRIGGER. THE GFS SHOWS A SIMILAR SOLUTION, BUT IS WEAKER
WITH THE AFOREMENTIONED PARAMETERS. DESPITE THIS, FELT IS BEST TO
INTRODUCE A SLIGHT CHANCE OF THUNDERSTORMS FOR THOSE AREAS SUNDAY
AFTERNOON AND EVENING.
THE UPPER TROUGH WILL TRANSITION TO AN UPPER LOW MONDAY WITH
MULTIPLE SHORTWAVE MOVING THROUGH AND INSTABILITY INCREASING ENOUGH
TO KEEP A SLIGHT MENTION OF STORMS FOR THE CASCADES AND SISKIYOUS.
THE MODELS SHOW A NORTHERN BRANCH OF THE JET BECOMING A BIGGER PLAY
MAKER FROM TUESDAY INTO THE END OF THE NEXT WEEK. THIS WILL PUSH THE
UPPER LOW SOUTH TUESDAY, THUS KEEPING ANY THREAT OF STORMS SOUTH OF
THE FORECAST AREA. THE UPPER TROUGH WILL AMPLIFY WEDNESDAY INTO
THE END OF THE WEEK. THIS WILL KEEP US DRY WITH NEAR NORMAL
TEMPERATURES. -PETRUCELLI
&&
.AVIATION...BASED ON THE 14/18Z TAF CYCLE...
EXPECT MVFR CIGS ALONG THE COAST NORTH OF CAPE BLANCO THIS
AFTERNOON, BUT IFR TO LIFR CIGS REDEVELOP THIS EVENING AND
OVERNIGHT. INLAND, VFR WILL PREVAIL BUT WITH TERRAIN OBSCURED IN
SOME AREAS THIS AFTERNOON. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE EXPECTED FROM ABOUT HIGHWAY 140 NORTH AND EASTWARD
THROUGH THIS EVENING. VFR IS EXPECT TONIGHT, THOUGH MVFR CIGS WILL
PROBABLY DEVELOP IN THE UMPQUA VALLEY AND LAST THROUGH MID TO LATE
MORNING FRIDAY. SPILDE
&&
.MARINE...UPDATED 230 PM PDT WED 14 AUG 2014...
THE WATERS WILL REMAIN BETWEEN HIGH PRESSURE CENTERED OFFSHORE AND
LOW PRESSURE INLAND WITH A GRADUAL TREND OF INCREASING NORTH WINDS
INTO THE WEEKEND. THIS IS LIKELY TO RESULT IN SMALL CRAFT
ADVISORY LEVEL WINDS AND SEAS IN THE OUTER WATERS SOUTH OF CAPE
BLANCO ON SATURDAY THEN ACROSS A LARGER PORTION OF THE WATERS ON
SUNDAY...WITH THE STRONGEST WINDS REMAINING IN THE OUTER WATERS
SOUTH OF CAPE BLANCO. THE INFLUENCE ON SEA HEIGHTS WILL REMAIN
RELATIVELY BALANCED BETWEEN WIND WAVE AND SWELL THROUGH SATURDAY
THEN THE STRONGER WINDS WILL TIP THE BALANCE ON SUNDAY. MODERATE
WINDS AND SEAS MAY CONTINUE THROUGH THE FIRST HALF OF NEXT WEEK WITH
A CONTINUATION OF HIGH PRESSURE OFFSHORE AND LOW PRESSURE INLAND.
/DW
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
CA...NONE.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
250 PM CDT THU AUG 14 2014
.SHORT TERM /NOW THROUGH FRIDAY NIGHT...AFTERNOON WATER VAPOR
SHOWS DRY AIR MOVING THROUGH SOUTH TEXAS INTO THE NORTHERN
PORTIONS OF THE CWA. CRP SOUNDING SHOWED PWATS OF 1.51 INCHES.
DOWN IN THE VALLEY...MORE MOISTURE IS PRESENT WITH BRO SOUNDING OF
2.04. SEA BREEZE IS MOVING INLAND WITH A FEW SHOWERS ACROSS THE
COASTAL COUNTIES. HRRR SHOWS ISOLATED SHOWERS CONTINUING ALONG THE
SEA BREEZE WITH MOST ACTIVITY DONE AND OVER WITH BY EARLY EVENING.
HAVE SLIGHT CHANCE POPS FOLLOWING THE SEA BREEZE THROUGH THE REST
OF THE DAY. HIGHS STILL EXPECTED INTO THE MID-UPPER 90S WITH LOWER
100S ACROSS THE UPPER VALLEY.
NAM 500-300MB RH SHOWS DRY AIR ENGULFING THE AREA BY MID EVENING
WHICH WILL SHUT DOWN ANY PRECIP REMAINING. THEREFORE...SKIES WILL
CLEAR OUT AND WINDS WILL SUBSIDE ALLOWING TEMPERATURES TO FALL INTO
THE MID-UPPER 70S TO AROUND 80 DEGREES.
FRIDAY A SHORTWAVE TROUGH WILL MOVE DOWN THE EASTERN SIDE OF THE
RIDGE PARKED OVER THE SOUTHWEST WHICH WILL HELP STRENGTHEN SURFACE
TROUGHING TO OUR WEST AND STRENGTHEN WINDS ACROSS THE AREA FRIDAY
AFTERNOON THROUGH THE SHORT TERM. BREEZIER CONDITIONS EXPECTED
FRIDAY AFTERNOON IN THE VALLEY AND PROGRESSES INTO THE COASTAL
WATERS FRIDAY NIGHT. NOT MUCH IN THE WAY OF PRECIP FRIDAY WITH
LOWERED 1000-500MB RH AND PWATS FALLING TO 1.7 INCHES. DID PUT 10
POPS FOR EAST OF HWY 281 BUT NOTHING MENTIONABLE IN THE ZONES.
FAVORED THE ECMWF MOS FOR TEMPERATURES SINCE MAV/MET SEEM A LITTLE
LOW FOR THIS REGIME.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...A PERSISTENT H5 RIDGE
WILL STRETCH FROM THE DESERT SOUTHWEST TO THE FLORIDA PENINSULA
AND WILL DOMINATE THE UPPER PATTERN THROUGH THE MAJORITY OF THE
PERIOD. THE RIDGE WILL NATURALLY EXHIBIT WEAKNESS OVER THE WEST
GULF HOWEVER... SIMPLY A REFLECTION OF THE TWO STRONGER ENDS OF
THE BARBELL TO THE EAST AND WEST. SFC HIGH PRESSURE WILL BE
SUPPORTED OVER THE NORTH AND EAST GULF...PROVIDING A MODERATE
ANTICYCLONIC FLOW OVER THE WEST GULF AND THE CWA. DRIER AIR WILL
HOLD SWAY OVER LAND AREAS WITH JUST A SILENT SLIGHT CHANCE OF RAIN
FOR THE GULF THROUGH MUCH OF THE LONG TERM. AN EXCEPTION WILL BE
NEXT WEDNESDAY WHEN A SLUG OF MOISTURE MOVES UP FROM THE SOUTH AND
APPEARS TO HAVE ENOUGH JUICE TO JUSTIFY A NONSILENT 20 PERCENT
CHANCE OF SHOWERS AND TSTMS. THIS UPTICK IN POPS REPRESENTS THE
EFFECTS OF A TROPICAL WAVE MOVING INTO THE SOUTHWEST GULF AT THAT
TIME. OTHERWISE...WITH SUCH CONSISTENCY IN THE FORECAST. THERE WAS
NOT MUCH REASON TO CHANGE THE INHERITED FORECAST SIGNIFICANTLY.
TEMPS WILL RUN SLIGHTLY ABOVE NORMAL WITH LIGHT TO MODERATE
ONSHORE WINDS AND A MIX OF CLOUDS AND SUN. AFTN HEAT LOWS INLAND
WILL TIGHTEN THE GRADIENT SOMEWHAT WITH BREEZY AND GUSTY WINDS
SHOWING UP OVER STARR AND ZAPATA COUNTIES. NO MAJOR DIFFERENCES
NOTED BETWEEN THE GFS AND ECMWF AT THIS WRITING.
&&
.MARINE...
NOW THROUGH FRIDAY NIGHT...WINDS WILL REMAIN LIGHT TO MODERATE
WITH LOW SEAS THROUGH FRIDAY MORNING. WINDS AND SEAS WILL BEGIN TO
INCREASE FRIDAY AFTERNOON AND EVENING AS LOW PRESSURE STRENGTHENS
TO OUR WEST AND INTERACTS WITH HIGH PRESSURE OVER THE GULF. SMALL
CRAFT EXERCISE CAUTION MAY BE NEEDED FOR THE LAGUNA FRIDAY AND THE
OFFSHORE WATERS FRIDAY NIGHT
SATURDAY THROUGH MONDAY...BROAD H5 RIDGING FROM THE SOUTHWEST
UNITED STATES EAST ACROSS THE GULF THROUGH THE NORTH ATLANTIC
WILL SUPPORT HIGH PRESSURE ACROSS THE NORTH GULF AT THE SURFACE.
SLIGHTLY LOWER PRESSURE WILL PERSIST OVER THE BAY OF CAMPECHE. A
SLIGHT WEAKNESS OVER THE WEST GULF SPLITTING THE MAIN RIDGE WILL
KEEP THE DOOR OPEN FOR SLIGHTLY ENHANCED MARINE SHOWER AND TSTM
ACTIVITY. MODERATE TO BREEZY SOUTH SOUTHEAST WINDS WILL PREVAIL
WITH MODERATE SEAS OF 3 TO 4 FEET WHICH MAY INCREASE A FOOT OR SO
LATE IN THE WEEKEND. SMALL CRAFT EXERCISE CAUTION CONDITIONS MAY
BE POSSIBLE FROM TIME TO TIME DUE TO STRONGER WINDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
BAYVIEW/PORT ISABEL 79 96 82 95 / 10 10 10 10
BROWNSVILLE 78 96 80 96 / 10 10 10 10
HARLINGEN 77 99 80 99 / 10 10 10 10
MCALLEN 79 102 80 101 / 10 10 10 10
RIO GRANDE CITY 79 103 80 103 / 10 10 10 10
SOUTH PADRE ISLAND 81 87 83 91 / 10 10 10 10
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55/54/65/MARTINEZ
AREA FORECAST DISCUSSION
NWS BROWNSVILLE TX
1158 AM CDT THU AUG 14 2014
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
&&
.AVIATION...MORNING WATER VAPOR IMAGERY SHOWS DRY AIR ACROSS
SOUTHERN TEXAS NOSING INTO OUR NORTHERN COUNTIES NORTH OF THE
VALLEY. DRY AIR WAS SEEN ON CRP 12Z SOUNDING BUT STILL RATHER
MOIST ON BRO SOUNDING. HRRR SHOWS SEABREEZE SHRA/TSRA DEVELOPING
AND MOVING INLAND THE FIRST COUPLE OF HOURS OF THE TAF PERIOD
BEFORE DRIER MID/UPPER LEVEL AIR MOVES IN AND SHUTS DOWN THE RAIN
CHANCES. THEREFORE...HAVE PLACED VCTS IN THE TAFS UP UNTIL 23Z.
AFTERWARDS...WINDS WILL DECREASE OVERNIGHT. FOR FRIDAY...WINDS
WILL INCREASE AND BECOME GUSTY BY 18Z AS LOW PRESSURE STRENGTHENS
TO OUR NORTHWEST.
&&
.PREV DISCUSSION... /ISSUED 603 AM CDT THU AUG 14 2014/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...VFR CONDITIONS WILL PREVAIL FOR TODAY OVER THE TERMINALS
WITH LIGHT AND VARIABLY WINDS FOR THE EARLY MORNING HOURS. A FEW TO
SCT CUMULUS WILL BEGIN TO DEVELOP AS DAYTIME HEATING BEGINS WITH
VFR CONDITIONS CONTINUING. THE EAST WINDS WILL INCREASE AS THE SEA
BREEZE DEVELOPS AROUND 18Z WITH A FEW ISO SHOWERS OR THUNDERSTORM
DEVELOPING. THE WINDS WILL LOWER BETWEEN 10 TO 15 KNOTS SHIFTING
SOUTHEAST IN THE EVENING AND REMAIN LIGHT AND CALM THROUGH THE
NIGHT.
PREV DISCUSSION... /ISSUED 413 AM CDT THU AUG 14 2014/
SHORT TERM /NOW THROUGH FRIDAY...LATEST WATER VAPOR SATELLITE
IMAGERY SHOWS BROAD HIGH PRESSURE GRADUALLY SHIFTING EASTWARD INTO
THE CENTRAL PLAINS TODAY AS CLOSED LOW PRESSURE ENTERS THE PACIFIC
NORTHWEST COAST. HIGH WILL FLATTEN AND REMAIN IN CONTROL ACROSS THE
DESERT SOUTHWEST TODAY INFILTRATING DRY AIR ALOFT INTO SOUTH TEXAS.
THE CHANCES OF RAIN LOWER TODAY AND TOMORROW DUE TO THE INFLUENCE OF
THIS DRIER AIR INTO THE AREA. TODAY...EASTERLY FLOW WILL ENHANCE THE
SEA BREEZE TODAY. RH VALUES AROUND 1000 TO 500 MB RANGE FROM 50 TO
60 PERCENT ESPECIALLY OVER THE RGV WHILE OVER THE NORTHERN COUNTIES
RH VALUES REMAIN BELOW 40 TO 45 PERCENT. LEFT INHERITED 20 PERCENT
POPS ESPECIALLY FAVORING THE LOWER AND MIDDLE VALLEY. IN ADDITION...
HEIGHTS RISE ACROSS WESTERN COUNTIES AND THE 850MB TEMPS INCREASE
TO 20 TO 22 DEGREES ALLOWING FOR HIGH TEMPERATURES TO INCREASE
ACROSS THE AREA. HIGHS WILL RANGE FROM 100 TO 103 DEGREES WEST OF
HIGHWAY 281 AND THE UPPER 90S ALONG HIGHWAY 77/83 EAST INTO THE
COAST.
THURSDAY NIGHT...SURFACE LOW MOVES INTO THE AREA SHIFTING WINDS
OVERNIGHT SOUTHEAST WIND MOSTLY CLEAR SKY CONDITIONS. LOW TEMPS
WILL COOL DOWN INTO THE MID TO LOW 70S IN THE NORTHERN COUNTIES.
THE WINDS WILL REMAIN CALM OVERNIGHT WITH LOW CHANCE OF RAIN.
FRIDAY...EXPECT ALMOST A REPEAT OF THURSDAY BUT WITH LESS SHOWER
ACTIVITY ANTICIPATED AND AN INCREASE IN SOUTHEAST WINDS FOR THE
AFTERNOON HOURS AS THE INFLUENCE OF THE DRIER AIR FROM THE HIGH
PRESSURE MOVES INTO THE AREA. HEIGHTS ALSO RISE AS THE HIGH
EXPANDS ACROSS SOUTH TEXAS AND PWATS VALUES LOWER INTO 1.8 IN
WITH LESS RH VALUES AS WELL. THIS IS NOT FAVORABLE CONVECTION AS
THE SEA BREEZE DEVELOPS. HIGH TEMPERATURES RISE A FEW DEGREES
MORE WITH MORE LOCATIONS OUT WEST BETWEEN 101 TO 103 DEGREES.
PRESSURE GRADIENT WILL STRENGTHEN AS THE THERMAL LOW DEEPENS TO
WEST AND INTERACT WITH HIGH PRESSURE TO EAST ALLOWING FOR SE WINDS
TO INCREASE IN THE AFTERNOON HOURS.
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...500 MB HIGH PRESSURE
CENTERED OVER THE DESERT SOUTHWEST AND THE FLORIDA PENINSULA WILL
BE THE DOMINANT WEATHER PATTERN OVER DEEP SOUTH TEXAS THROUGHOUT
THE MAJORITY OF THE PERIOD. WITH THESE WEATHER SYSTEMS...AND AN
ATMOSPHERE DRYING TO A PRECIPITABLE WATER CONTENT OF NEAR 1.50
INCHES...DRY WEATHER WILL RESULT. THE MOST SIGNIFICANT CHANGE TO
THE LONG TERM PORTION OF THE FORECAST WAS THE INCLUSION OF A
SLIGHT CHANCE OF PRECIPITATION FOR THE EASTERN PORTION OF THE BRO
CWFA AND ADJACENT COASTAL WATERS FOR WEDNESDAY AS A WEAK INVERTED
500 MB TROUGH FORMS ALONG THE EAST COAST OF MEXICO AND BETWEEN THE
TWO 500 MB HIGHS. INHERITED VERY HOT HIGH TEMPERATURES WERE LEFT
IN PLACE WITH NO REAL GOOD REASON FOR ADJUSTING THEM DOWNWARD.
MARINE...NOW THROUGH FRIDAY...WINDS WILL REMAIN LIGHT AND MODERATE
WITH LOW SEAS THROUGH THE SHORT TERM FORECAST. CHANCE OF RAIN IS
POSSIBLE THROUGH THE DAY WITH SEA BREEZE DEVELOPING OVER THE COASTAL
WATERS AND NEAR THE COAST MOVING WESTWARD. NO SCEC OR SCA AT THIS
TIME.
FRIDAY NIGHT THROUGH WEDNESDAY...FAVORABLE MARINE CONDITIONS FRIDAY
NIGHT WILL YIELD TO STRONGER WINDS AND ROUGHER SEAS SATURDAY THROUGH
TUESDAY AS HIGH PRESSURE OVER THE GULF OF MEXICO INTERACTS WITH LOW
PRESSURE OVER TEXAS. SMALL CRAFT EXERCISE CAUTION OR SMALL CRAFT
ADVISORY ARE POSSIBLE DURING THIS TIME PERIOD FOR THE LOWER TEXAS
COASTAL WATERS. MARINE CONDITIONS MAY IMPROVE SLIGHTLY ON WEDNESDAY.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
55
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
135 PM EDT THU AUG 14 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL REINFORCE THE DRY AIRMASS ON THURSDAY...BUT
COULD BRING A FEW SHOWERS TO THE MOUNTAINS. HIGH PRESSURE WILL
BUILD IN FOR FRIDAY AND SATURDAY. NEXT FRONTAL SYSTEM LOOKS TO
IMPACT US EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM EDT THURSDAY...
ADJUSTED POPS ALONG THE WESTERN SLOPES THIS AFTERNOON AND EXTENDED
CLOUD COVER FURTHER EAST. MINOR ADJUSTMENTS IN TEMPERATURES AND
DEW POINTS FOR THIS AFTERNOON.
AS OF 930 AM EDT THURSDAY...
MADE SOME MINOR ADJUSTMENTS IN TEMPERATURES AND CLOUD COVER FOR
THIS MORNING INTO THIS AFTERNOON. HRRR AND RNK WRFARW CONTINUE TO
SHOW A FEW SHOWERS WITH THE WEAK COLD FRONT WHICH DROP SOUTHEAST
ACROSS THE REGION. WITH LATEST REGIONAL WRS-88D LOOP SUGGESTING
THAT CONVECTION TO OUR WEST IS DIMINISHING WILL HOLD TO JUST IN
THE WEST. HIGHS THIS AFTERNOON WILL RANGE FROM THE MID 60S IN THE
NORTHWEST TO THE LOWER 80S IN THE SOUTHEAST.
AS OF 710 AM EDT THURSDAY...
UPDATED FORECAST TO ACCOUNT FOR MORE CLOUDS ARRIVING TODAY FROM
THE NW PER IMPULSE NOW OVER NRN KY. THE HIGH-RES MODELS AS WELL AS
THE 06Z GFS/00Z ECMWF ALLOW FOR CLOUDS TO EXPAND EAST INTO THE
FOOTHILLS THIS AFTERNOON...AND BRING ISOLATED/WIDELY SCATTERED
SHOWERS TO THE MTNS OF WV/VA COUNTIES ADJACENT LATER THIS MORNING.
MAY SEE SOME SPRINKLES AS FAR EAST AS THE INTERSTATE 81 CORRIDOR
THIS AFTERNOON. OTHERWISE...NO CHANGES TO THE TEMPS FOR HIGHS.
PREVIOUS VALID DISCUSSION...
HIGHS TODAY WILL BE BELOW NORMAL...STILL THINK MORE SUNSHINE MOST
LOCATIONS...THOUGH POTENTIAL AGAIN FOR THE MTNS STAYING PARTLY
SUNNY- MOSTLY CLOUDY THRU THE DAY. EXPECT HIGHS TO RANGE FROM THE
LOWER TO MID 70S IN THE MOUNTAINS...NEW RIVER VALLEY...TO LOWER TO
MID 80S EAST OF THE BLUE RIDGE AND SRN SHENANDOAH VALLEY.
TONIGHT...ANY SHOWERS OVER THE HIGHER RIDGES OF SE WV WILL
DISSIPATE. STILL UPPER TROUGH CONTINUES TO LINGER OVER THE AREA
WITH ANOTHER SHORTWAVE ROUNDING THE BASE OF THE TROUGH THROUGH WV
LATE. THINK THE CLOUD COVER WILL BE SCATTERED...THOUGH NOT OUT OF
THE QUESTION TO SEE MORE CLOUDS INTO THE MTNS OF WV LATE. LOWS
WILL BE VARYING DEPENDING ON CLOUDS COVER BUT STILL LOOKING AT
COOLER TEMPS...BUT NOT LOOKING AT RECORD LOWS AT THIS
POINT...GIVEN THAT SOME CLOUD COVER MAY AFFECT TEMPS FALLING FAR.
UPPER 40S MTN VALLEYS TO MID TO UPPER 50S EAST OF THE BLUE RIDGE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 230 AM EDT THURSDAY...
OVERALL MAINLY A CONTINUED TEMPERATURE FORECAST AS THE STRONG 5H TROUGH
PIVOTS EAST ACROSS THE REGION INTO FRIDAY NIGHT BEFORE THE FLOW
TURNS MORE ZONAL OVER THE WEEKEND. THIS WILL ALLOW SURFACE HIGH
PRESSURE TO BUILD IN FRIDAY...WITH THE RIDGE ABOUT OVERHEAD SATURDAY...
BEFORE SLIDING TO THE SE SATURDAY NIGHT. HOWEVER BEFORE THE BETTER
SUBSIDENCE ARRIVES ON SATURDAY...WILL SEE A WEAK MID LEVEL WAVE PIVOT
BY TO THE NORTH BY FRIDAY NIGHT WITH AN ASSOCIATED SURFACE TROUGH
CROSSING THE AREA FRIDAY EVENING. ALTHOUGH MOISTURE LOOKS
LIMITED...DEWPOINTS DO INCREASE ACROSS THE SE LATE FRIDAY AS THE FLOW
BACKS MORE SW OUT EAST. LATEST MODELS SUGGEST COULD BE ISOLATED
SHRA/TSRA FROM NW N CAROLINA EAST INTO SOUTHSIDE VIRGINIA WHERE
GUIDANCE SHOWS AFTERNOON CAPE VALUES OF AROUND 1000 J/KG. SINCE IFFY
GIVEN EXTENT OF DRY AIR ALOFT...WILL ONLY INCLUDE A TOKEN ISOLATED
MENTION EXTREME SE NEAR DANVILLE AND POINTS EAST INTO FRIDAY EVENING
WHILE KEEPING ELSEWHERE DRY. MOISTURE SHOULD PIVOT FAR ENOUGH EAST
WITH THE RESIDUAL FRONT ALONG THE COAST TO KEEP THINGS DRY SATURDAY AND
MAINLY SOUTH OF THE MOISTURE AXIS WITH THE NEXT FRONT TO THE NORTH
SATURDAY NIGHT. DOES APPEAR MORE SHEARED HIGH CLOUDS POSSIBLE SATURDAY
AND THEN WARM ADVECTION MID/HIGH CLOUDS AHEAD OF THE FRONT OVERNIGHT AS
MOISTURE TRANSPORT INCREASES FROM THE WEST/SW.
LARGE DIURNAL RANGE IN TEMPERATURES WILL CONTINUE WITH HIGHS MOSTLY 70S
WEST AND LOW/MID 80S EAST BOTH FRIDAY/SATURDAY WITH LOWS AGAIN QUITE
COOL FRIDAY NIGHT IF SKIES CAN CLEAR. THINK BEST TO LEAN TOWARD THE
WARMER MAV MOS EAST BOTH DAYS GIVEN A BUMP IN 85H TEMPS ALOFT AHEAD OF
THE TROUGH FRIDAY...AND BETTER HEATING OF DRY AIR UNDER BACKING FLOW
SATURDAY. STILL LIKELY TO SEE SOME 40S IN THE VALLEYS FRIDAY NIGHT...
AND 50S ELSEWHERE BEFORE THINGS MOISTEN SATURDAY NIGHT WHEN MOST LOWS
WILL STAY IN THE UPPER 50S TO MID 60S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 PM EDT WEDNESDAY...
THE UPPER LEVEL PATTERN DEAMPLIFIES NEXT WEEK WITH A BROADER UPPER
LEVEL TROUGH OVER THE CONUS YIELDING A STEADY STREAM OF WESTERLIES
ALOFT. THE DOMINANT 500MB PLAYERS LOOK TO BE RIDGING NEAR THE
SOUTHERN TIP OF GREENLAND AND A DEVELOPING RIDGE NEAR 40N/140W...
SOUTH OF THE GULF OF ALASKA AND WEST OF CALIFORNIA. IN BETWEEN...
ACROSS THE LOWER 48...WE ARE LEFT WITH A BROAD TROUGH WITH LITTLE
AMPLITUDE...SENSIBLE WEATHER DETERMINED BY SERIES OF SHORT WAVES
THAT WILL PASS THROUGH THE FLOW DURING THE WEEK. AT THE SURFACE
THE DEPARTING AREA OF HIGH PRESSURE THIS WEEKEND WILL BE REPLACED
BY A NEARLY STATIONARY...W-E ORIENTED WAVY FRONT...THAT WILL SET
UP MID CONUS...AND HELPING TO FOCUS SOME OF THE SENSIBLE WEATHER
ELEMENTS DURING THE WEEK.
DETERMINISTIC MODELS ARE QUITE DIFFERENT IN THE TIMING OF THESE
SHORT WAVES...THE GFS A DAY OR TWO FASTER THAN THE ECMWF AT MOVING
THESE FEATURES EAST BOUND. PREFERENCE IS TO GO WITH THE SLOWER
SOLUTIONS...INTRODUCING SLIGHT CHANCE FOR DIURNAL DEEP CONVECTION
WEST OF THE BLUE RIDGE SUNDAY...THEN AREAWIDE MONDAY AND INTO THE
MIDDLE OF NEXT WEEK PER RETURN OF HIGHER DEWPOINTS AND INSTABILITY
COUPLED WITH ANY SHORT WAVE FEATURES THAT PASS VIA THE PREDOMINANT
WESTERLY FLOW ALOFT.
TEMPERATURES AS A WHOLE FOR NEXT WEEK LOOK LIKE THEY WILL PAN OUT TO
BE NORMAL...A GENERAL LACK OF AMPLIFICATION IN THE WEATHER PATTERN
LEADING TO FEWER TEMPERATURE ANOMALIES.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 135 PM EDT THURSDAY...
VFR WILL PREVAIL THIS AFTERNOON INTO TONIGHT WITH ISOLATED
MVFR SHOWERS/SPRINKLES WITH WEAK FRONT DROPPING SOUTHEAST ACROSS
THE AREA.
BKN VFR CIGS ARE POSSIBLE AS FAR EAST AS THE FOOTHILLS...WITH
SCATTERING OUT OF CLOUDS THIS EVENING INTO TONIGHT. FOG AGAIN A
GOOD BET AT LWB/BCB LATE TONIGHT...BUT CONFIDENCE NOT HIGH IN
BRINGING THEM TOO FAR DOWN...AS NEXT UPSTREAM WAVE MAY BRING
CLOUDS IN LATE TO PREVENT FOG FROM BECOMING DENSE.
VFR CONDITIONS ARE EXPECTED FRIDAY. CAN NOT RULE OUT AN ISOLATED
THUNDERSTORM IN THE SOUTH ALONG THE VIRGINIA AND NORTH CAROLINA
BORDER.
MEDIUM TO HIGH CONFIDENCE IN THE CEILINGS...VISIBILITIES AND WINDS
DURING THE TAF PERIOD.
EXPECT MAINLY VFR THROUGH THE END OF THE WEEK...WITH HIGH PRESSURE
IN PLACE. VALLEY FOG AT LWB/BCB POSSIBLE EACH MORNING.
HIGH PRESSURE MOVES OFF THE COAST BY SUNDAY WITH A FRONT ARRIVING
SUNDAY OR MONDAY WHICH COULD BRING SHOWERS AND STORMS AND SUB VFR
CEILINGS AND VISIBILITIES TO THE REGION.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...KK/WP
SHORT TERM...JH
LONG TERM...PM
AVIATION...KK/WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1141 AM MDT THU AUG 14 2014
.UPDATE...
ISSUED AT 900 AM MDT THU AUG 14 2014
AFTER CHECKING THE 12Z MODEL RUNS AND LATEST SATELLITE...RADAR...
AND SURFACE OBSERVATIONS HAVE MADE SOME ADJUSTMENTS TO THE
FORECAST TODAY. TEMPERATURES ARE STRUGGLING TO WARM OVER MOST OF
THE FORECAST AREA DUE TO THICK CLOUD COVER AND RAIN SHOWERS.
CHEYENNE IS CURRENTLY 70 DEGREES AND NOT LIKELY TO WARM TO MUCH
FURTHER BEFORE SHOWERS DEVELOP. THIS WILL BE SIMILAR TO MUCH OF
THE PLAINS IN SOUTHEAST WYOMING. INTO THE NEBRASKA PANHANDLE...
PLACES LIKE SIDNEY AND ALLIANCE MAY APPROACH 90 DEGREES BEFORE
THICKER CLOUDS MOVE IN...OTHERWISE TEMPERATURES SHOULD GENERALLY
ONLY HIT 80-85 DEGREES TODAY IN THE PANHANDLE.
LOOKING AT WATER VAPOR AND VISIBLE SATELLITE...THE PLACEMENT OF
SHORTWAVE ENERGY IS NOT WHAT THE MODELS WERE SHOWING YESTERDAY.
YESTERDAY MODELS WERE SHOWING ONE SHORTWAVE MOVING ACROSS SOUTHEAST
WYOMING...BUT IN FACT THERE ARE TWO SEPARATE CIRCULATIONS. ONE
OVER CENTRAL WYOMING WHICH IS LIFTING NORTH AND ONE OVER WESTERN
COLORADO MOVING EAST. THEREFORE THE DYNAMIC SETUP IS NOT AS
FAVORABLE FOR SOUTHEAST WYOMING AS EARLIER EXPECTED. THIS MEANS
THE THREAT FOR HEAVY RAIN IS MINIMAL TODAY. ALSO THE 12Z MODELS
ARE SHOWING LESS INSTABILITY AND CAPE TODAY WHICH ALSO SUGGESTS
MINIMAL HEAVY RAIN THREAT. SO FOR THE REST OF TODAY SHOULD SEE
SHOWERS SPREAD EAST INTO THE PLAINS WITH ISOLATED THUNDERSTORMS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
LATEST WATER VAPOR IMAGERY SHOWING THE UPPER LEVEL LOW PUSHING
INTO NORTHWESTERN COLORADO THIS MORNING. LOOKS TO BE HANDLED WELL
BY THE ECMWF. LATEST MOSAIC RADAR SHOWING SHOWERS WIDESPREAD OVER
RIVERTONS CWFA WITH SOME SHOWER ACTIVITY OVER CARBON COUNTY.
MESOWEST OBSERVATIONS REPORTING MEASURABLE RAINFALL OVER THE SNOWY
AND SIERRA MADRE RANGES AS WELL AS THE NORTH LARAMIE RANGE.
FOR TODAY...WE SHOULD SEE AN INCREASE IN SHOWERS AND THUNDERSTORMS
AS THE MORNING PROGRESSES. UPPER LOW MOVES OVER CASPER BY 00Z WITH
FAIRLY WIDESPREAD SHOWERS OVER OUR SOUTHERN ZONES. PWATS FOR
RAWLINS FROM THE NAM UP NEAR 1.2 INCHES AT 18Z...NEAR 1.4 INCHES
HERE AT CHEYENNE BY 00Z AND NEAR 1.7 INCHES AT CHADRON BY 06Z THIS
EVENING. LATEST HRRR FORECAST AND FORECAST IR IMAGERY SHOWING
SHOWERS AND THUNDERSTORMS EAST OF THE LARAMIE RANGE BREAKING OUT
HERE AT CHEYENNE AROUND 15Z AND OUT IN THE PANHANDLE AFTER 18Z.
FORECAST STORM MOTIONS A LITTLE HIGHER THAN PREVIOUSLY FORECAST
WITH NAM SHOWING 10-15KTS. GIVEN THAT STORM MOTIONS ARE
HIGHER...HAVE DECIDED TO HOLD OFF ON A FLASH FLOOD WATCH. WOULD
THINK WE COULD SEE SOME FLASH FLOOD WARNING POSSIBLE THIS
AFTERNOON...BUT THESE WILL BE FOR TRAINING STORMS AND NOT FOR SLOW
MOVING STORMS. MAY TAKE ANOTHER LOOK LATER THIS MORNING WHEN THE
06Z MODEL DATA COMES OUT.
LOOKS LIKE SHOWERS AND THUNDERSTORMS WILL COME TO AN END BY 06Z
TONIGHT AS THE ECMWF SHOWS SHORTWAVE MOVING INTO CENTRAL SOUTH
DAKOTA AND CENTRAL NEBRASKA. STILL SOME POSITIVE VORTICITY
ADVECTION OVER THE NORTHERN PANHANDLE FRIDAY MORNING...SO DID KEEP
SOME SLIGHT CHANCE POPS GOING OUT THAT WAY FOR FRIDAY MORNING AND
AFTERNOON.
UPPER RIDGE BUILDS BACK INTO THE AREA FRIDAY NIGHT INTO SATURDAY AS
SHORTWAVE BEGINS TO MOVE SOUTHEAST INTO EASTERN KANSAS. 700MB
WINDS PICKING UP TO 20-25KTS ACROSS THE CWFA MAY LEAD TO
HEIGHTENED FIRE WEATHER CONCERNS SATURDAY...MORE LIKELY THOUGH ON
SUNDAY.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM MDT THU AUG 14 2014
SATURDAY NIGHT...DRY PERIOD WITH LIMITED LOW AND MID LEVEL MOISTURE
AND DOWNSLOPE WEST WINDS.
SUNDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES ACROSS EASTERN MONTANA
AND EASTERN WYOMING WITH AN ASSOCIATED SURFACE TROUGH. ISOLATED
SHOWERS AND THUNDERSTORMS EXPECTED...NORTH OF A DOUGLAS TO
SCOTTSBLUFF LINE.
MONDAY...RELATIVELY DRY NORTHWEST FLOW ALOFT PREVAILS...THOUGH LOOKS
LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR ISOLATED LATE DAY SHOWERS
AND THUNDERSTORMS FROM WHEATLAND TO ALLIANCE.
TUESDAY...SLIGHT DECREASE IN LOW AND MID LEVEL MOISTURE...ACTING AS
THE FUEL FOR THUNDERSTORMS...THUS ONLY ISOLATED STORMS AT
BEST...NORTH OF A RAWLINS TO SCOTTSBLUFF LINE.
WEDNESDAY...DRY WEST WINDS PREVAIL IN THE LOW AND MID
LEVELS...EFFECTIVELY DRYING OUT THE ATMOSPHERE EVEN MORE...AND
PRODUCING A MILD LATE AUGUST DAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1131 AM MDT THU AUG 14 2014
SCATTERED LIGHT SHOWERS CAN BE EXPECTED FOR ALL TERMINALS DURING
THE AFTN AND EVE HOURS. A FEW LIGHTNING STRIKES ARE POSSIBLE OVER
THE WESTERN NE PANHANDLE AFTER 21Z WHERE INSTABILITY IS HIGHER DUE
TO MORNING SUNSHINE. EXPECT THAT IMPACTS FROM THIS RAIN EVENT WILL
BE LOWER THAN EARLIER THOUGHT...SO THE GENERAL RULE SHOULD BE VFR
CONDITIONS THROUGH THE TAF PERIOD. LOW CLOUDS AND MVFR CIGS MAY
HANG AROUND RWL FOR A FEW MORE HOURS...BUT CONDITIONS ARE LIKELY
TO IMPOVE THERE SOON.
&&
.FIRE WEATHER...
ISSUED AT 350 AM MDT THU AUG 14 2014
WIDESPREAD WETTING RAINS TODAY BEGINNING OVER CARBON COUNTY...THEN
SPREADING EAST. THIS IS DUE TO A UPPER LEVEL LOW PRESSURE SYSTEM
MOVING SLOWLY NORTHEAST AND INTERACTING WITH MONSOONAL MOISTURE
OVER THE AREA. THIS LOW WILL KEEP UNSETTLED WEATHER OVER SOUTHEAST
WYOMING AND NEBRASKA PANHANDLE THROUGH FRIDAY AFTERNOON AS THE LOW
SLOWLY MOVES OUT OF THE AREA. DRIER CONDITIONS AFTER FRIDAY
AFTERNOON AS WESTERLY WINDS RETURN. AFTERNOON HUMIDITIES SATURDAY
AND SUNDAY WILL LOOK TO BECOME CRITICAL WEST OF THE LARAMIE RANGE.
GUSTY WESTERLY WINDS AS WELL BOTH AFTERNOONS THAT COULD REACH
CRITICAL CRITERIA.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...SML
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...HAMMER
FIRE WEATHER...CLAYCOMB