Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/11/15
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
1240 AM CDT SUN AUG 9 2015
.AVIATION...
OVERALL VFR FLIGHT CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS.
PATCHY MVFR MAY DEVELOP TOWARD SUNDAY MORNING...BUT COVERAGE IS
EXPECTED TO REMAIN LOW. AN ISOLATED SHOWER OR THUNDERSTORM MAY
DEVELOP BUT COVERAGE WILL BE VERY LOW AND DID NOT INCLUDE IN TAFS.
WINDS WILL BE LIGHT AND VARIABLE OVER CENTRAL AREAS...WHILE LIGHT
FROM THE SOUTH OVER SOUTHERN AR...SW TO SE AT 3 TO 9 MPH OVER
NORTHERN AR. VFR CONDITIONS ARE EXPECTED ON SUNDAY WITH OVERALL A
SOUTH WIND FLOW.
&&
.PREV DISCUSSION... /ISSUED 304 PM CDT SAT AUG 8 2015/
SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
A FEW ISOLATED SHOWERS AND THUNDERSTORMS HAVE POPPED UP ACROSS THE
STATE DURING THE LAST COUPLE OF HOURS AND THESE HAVE BEEN EXTREMELY
ISOLATED IN NATURE. WITH A STALLED BOUNDARY ACROSS THE STATE...DO
EXPECT A FEW MORE SHOWERS AND THUNDERSTORMS TO POP UP IN THE HEAT OF
THE DAY...WHICH THE HRRR HAS BEEN CONSISTENT IN SHOWING AS WELL.
SUNDAY WILL BE SLIGHTLY HOTTER AS THE RIDGE BUILDS INTO THE
AREA...THE AXIS OF HIGHEST DEW POINTS WILL SHIFT A BIT MORE TO THE
EAST. AS A RESULT...THIS WILL ADD NE ARKANSAS INTO THE HEAT ADVISORY.
A HOT DAY CAN BE EXPECTED ON MONDAY AS WELL WITH SLIGHTLY LOWER DEW
POINTS. AT THIS POINT IT APPEARS THE ONLY AREAS ABLE TO REACH
EXCESSIVE HEAT WARNING CRITERIA WILL BE ACROSS SE PORTIONS OF THE
CWA...BUT AT THIS POINT ITS BORDERLINE. WILL DEFER TO THE MID
SHIFT...AS THE NUMBERS ARE SO CLOSE TO CRITERIA. A FRONT WILL MOVE
THROUGH THE STATE ON MONDAY...WITH LITTLE IN THE WAY OF
PRECIPITATION EXPECTED UNTIL THE FRONT REACHES SOUTHERN ARKANSAS. IT
CONTINUES TO LOOK THAT THE BEST CHANCES FOR PRECIPITATION WILL BE TO
THE SOUTH OF THE STATE...BUT DID GO AND INCLUDE SLIGHT CHANCE POPS
ACROSS SOUTHERN PORTIONS OF THE STATE.
LONG TERM...WEDNESDAY THROUGH FRIDAY
SOME EXCESSIVE HEAT RELIEF IS IN STORE BEGINNING WEDNESDAY. AS
THE UPPER RIDGE SHIFTS WEST ALLOWING AND IN THE WAKE OF A WEAK
COLD FRONT MAX TEMPS DURING THIS PERIOD WILL RUN AT OR BELOW
NORMAL. DRIER CONDITIONS AS WELL AS DEWPOINTS FALL INTO THE UPPER
50S TO MID 60S. LOOKS TO BE A DRY PERIOD AS STABLE NORTHERLY FLOW
ALOFT AND WEAK NE SURFACE FLOW DOMINATE AND EMBEDDED UPPER LEVEL
DISTURBANCES SEEM UNLIKELY AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 74 99 79 98 / 0 0 10 20
CAMDEN AR 77 104 78 103 / 0 0 10 10
HARRISON AR 74 97 74 94 / 0 0 10 20
HOT SPRINGS AR 78 103 78 102 / 0 0 10 10
LITTLE ROCK AR 77 103 80 102 / 0 0 10 10
MONTICELLO AR 77 103 80 103 / 0 0 10 10
MOUNT IDA AR 75 102 74 102 / 0 0 10 10
MOUNTAIN HOME AR 74 98 75 96 / 0 0 10 20
NEWPORT AR 73 98 77 96 / 0 0 10 20
PINE BLUFF AR 76 103 78 101 / 0 0 10 10
RUSSELLVILLE AR 76 101 75 101 / 0 0 10 10
SEARCY AR 73 100 76 98 / 0 0 10 20
STUTTGART AR 75 101 77 99 / 0 0 10 20
&&
.LZK WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR BAXTER-BOONE-
CLEBURNE-INDEPENDENCE-JACKSON-MARION-MONROE-NEWTON-SEARCY-STONE-
VAN BUREN-WOODRUFF.
HEAT ADVISORY FROM 11 AM TO 8 PM CDT SUNDAY FOR BAXTER-BOONE-
CLEBURNE-FULTON-INDEPENDENCE-IZARD-JACKSON-MARION-NEWTON-SEARCY-
SHARP-STONE-VAN BUREN.
EXCESSIVE HEAT WARNING UNTIL 8 PM CDT THIS EVENING FOR ARKANSAS-
BRADLEY-CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-PRAIRIE-
PULASKI-SALINE-SCOTT-WHITE-YELL.
EXCESSIVE HEAT WARNING FROM 11 AM TO 8 PM CDT SUNDAY FOR
ARKANSAS-BRADLEY-CALHOUN-CLARK-CLEVELAND-CONWAY-DALLAS-DESHA-
DREW-FAULKNER-GARLAND-GRANT-HOT SPRING-JEFFERSON-JOHNSON-LINCOLN-
LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-POPE-
PRAIRIE-PULASKI-SALINE-SCOTT-WHITE-WOODRUFF-YELL.
HEAT ADVISORY FROM 11 AM TO 8 PM CDT MONDAY FOR ARKANSAS-BRADLEY-
CALHOUN-CLARK-CLEBURNE-CLEVELAND-CONWAY-DALLAS-DESHA-DREW-
FAULKNER-GARLAND-GRANT-HOT SPRING-JACKSON-JEFFERSON-JOHNSON-
LINCOLN-LOGAN-LONOKE-MONROE-MONTGOMERY-OUACHITA-PERRY-PIKE-POLK-
POPE-PRAIRIE-PULASKI-SALINE-SCOTT-VAN BUREN-WHITE-WOODRUFF-YELL.
&&
$$
AVIATION...51
AREA FORECAST DISCUSSION
NWS TUCSON AZ
226 PM MST SUN AUG 9 2015
.SYNOPSIS...ISOLATED TO SCATTERED THUNDERSTORMS MAINLY FROM TUCSON
EAST AND SOUTH THROUGH MIDWEEK FOLLOWED BY MARKEDLY REDUCED COVERAGE
OF THUNDERSTORMS BY LATE NEXT WEEK AND INTO THE EARLY PART OF NEXT
WEEKEND. ABOVE NORMAL DAYTIME TEMPERATURES WILL PREVAIL DURING THE
WEEK.
&&
.DISCUSSION...WATER VAPOR IMAGERY AND 09/12Z UPPER-AIR PLOTS SHOW A
RIDGE CENTERED OVER EAST TEXAS WITH A LOW PRESSURE SYSTEM OVER THE
PACIFIC NORTHWEST...AND A SHORTWAVE TROUGH OFF THE SOUTHERN
CALIFORNIA AND NORTHERN BAJA COASTS. A LARGE SWATH OF DRY MID-UPPER
LEVEL AIR COVERS MUCH OF THE EASTERN PACIFIC...SRN CALIFORNIA...
NORTHERN BAJA AND INTO WESTERN ARIZONA.
VISIBLE AND IR SATELLITE IMAGERY INDICATES THAT CUMULUS HAVE BEEN
DEVELOPING MAINLY OVER THE MOUNTAINS WITH THUNDERSTORMS NOW OVER
MOST OF THE MOUNTAIN TOPS. VALLEYS STILL MOSTLY SUNNY TO PARTLY
CLOUDY WITH SOME ACTIVITY PUSHING OFF INTO VALLEYS.
THIS MORNINGS 12Z KTWC SOUNDING REVEALED A DRIER AIRMASS COMPARED TO
24 HOURS AGO...WITH A PW OF 1.47 INCHES. YESTERDAYS 12Z KTWC PW WAS
1.72 INCHES. VARIOUS SOURCES OF PW THIS MORNING POINT TO AROUND 1.4-
1.5 INCHES. AT ANY RATE...ALL OF THIS MORNINGS PARAMETERS ON THE
SOUNDING INDICATE A `RELATIVELY` DRIER AIRMASS...AS WELL AS A TAD
LESS UNSTABLE. STILL AMPLE MOISTURE AND INSTABILITY TO ACCOUNT FOR
ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON FOR AREAS MAINLY
FROM TUCSON EAST AND SOUTH.
A WEAK DISTURBANCE CAN BE SEEN IN WV IMAGERY OVER SOUTHWEST
CHIHUAHUA MEXICO AND IS COINCIDENT WITH A COMPLEX OVER SRN SONORA.
THIS FEATURE SHOULD HEAD TO THE NORTHWEST THROUGH SONORA AND
EVENTUALLY TOWARD OR INTO SOUTHERN ARIZONA BY LATE TONIGHT. U OF A
WRF/NAM & RR SHOW ACTIVITY INCREASING OVER PARTS OF SANTA CRUZ AND
COCHISE COUNTIES LATE THIS EVENING...THEN THE COMPLEX EVOLVES TO AN
MCV OVER PORTIONS OF COCHISE COUNTY AS IT MOVES NORTH OVERNIGHT AND
EARLY MONDAY. IN ADDITION...MODELS SHOW PW`S INCREASE AS MOIST AIR
FROM THE SOUTH SPREADS NORTH OVERNIGHT AND INTO THE DAY ON MONDAY
WITH VALUES OF AROUND 1.5-1.7 INCHES ACROSS MOST OF THE
AREA...ALTHOUGH LESSER VALUES TOWARD NEW MEXICO. SO ALL THAT
SAID...I TRIED TO REFLECT CHANCE CATEGORY POPS FROM NOW THROUGH
AROUND SUNSET THIS EVENING FOR MOSTLY AREAS FROM TUCSON SOUTH AND
EAST...AND LESSER CHANCES FARTHER WEST. IN ADDITION...WITH THE
DISTURBANCE TO OUR SOUTH POTENTIALLY COMING UP AND TRIGGERING LATE
EVENING CONVECTION AS THE WRF/NAM IS SUGGESTING...MAINLY OVER SANTA
CRUZ AND COCHISE COUNTIES...I KEPT HIGHER POPS IN THAT AREA THROUGH
AROUND 09Z (2 AM MST). THEREAFTER...RAIN CHANCES SHOULD DECREASE
THROUGH MID MORNING MONDAY...BEFORE PICKING BACK UP AGAIN LATE
MONDAY MORNING INTO THE AFTERNOON. MONDAY SHOULD BE AS...OR EVEN
MORE...ACTIVE AS TODAY AS HIGHER MOISTURE...INCREASING INSTABILITY
AND ENHANCEMENT FROM THE DISTURBANCE AFFECTS SOUTHERN ARIZONA.
FOR LATE TUESDAY INTO WEDNESDAY MODELS SUGGEST THAT DRIER AIR WILL
SPREAD IN FROM THE EAST IN RESPONSE TO THE HIGH RETROGRADING TO A
POSITION NEAR EASTERN NEW MEXICO/TEXAS PANHANDLE MIDDAY WEDNESDAY.
THIS WILL RESULT IN THE BEST THREAT FOR THUNDERSTORMS WEDNESDAY
OCCURRING FROM AROUND THE NOGALES AREA TO THE WEST ACROSS THE TOHONO
O`ODHAM NATION.
BY LATE THURSDAY THE HIGH SHOULD BE IN THE GENERAL VICINITY OF
WESTERN/NORTHERN NEW MEXICO WITH EVEN LESSER RAIN CHANCES...
GENERALLY JUST ISOLATED IN NATURE FOR DESERTS/VALLEYS AND LOW END
SCATTERED FOR MOUNTAINS. A SIMILAR PICTURE FOR FRIDAY AND SATURDAY
AS THE HIGH SHOULD BE IN VIRTUALLY THE SAME LOCATION.
BY SUNDAY THE HIGH SHOULD BE OVER THE AZ/NM BORDER PER THE GFS
SOLUTION...OR OVER WESTERN AZ...BASED ON THE ECMWF. SOME RETURN IN
MOISTURE IS EXPECTED AT THAT TIME WITH A SLIGHT UPTICK IN RAIN
CHANCES.
FOR TUCSON...HIGH TEMPERATURES WILL GENERALLY BE NEAR NORMAL
MONDAY...THEN RANGING FROM 5 TO 8 DEGS ABOVE NORMAL DURING THE REST
OF THE FORECAST PERIOD...ALTHOUGH THE WARMEST DAYS WILL OCCUR
THURSDAY AND FRIDAY. LOW TEMPS WILL RANGE FROM AROUND 3 TO 5 DEGS
ABOVE NORMAL EACH MORNING.
&&
.AVIATION...VALID THRU 11/00Z.
ISO/SCT -TSRA/-SHRA POSSIBLE NEAR MOST TERMINALS THIS AFTERNOON
AND EVENING...WITH A FOCUS NEAR KOLS AND KDUG. ACTIVITY WILL
CONTINUE INTO TONIGHT...EVENTUALLY TRANSITIONING FROM MOSTLY
-TSRA TO MOSTLY -SHRA AFTER 10/08Z...-SHRA LINGERING A BIT LONGER
NEAR KDUG. BRIEF MVFR CONDITIONS AND WIND GUSTS 30 TO 40 KTS WILL
BE POSSIBLE NEAR STRONGER STORMS. OTHERWISE...OUTSIDE OF
THUNDERSTORM INFLUENCE SKIES WILL GENERALLY BE SCT TO BKN 7 TO 12
KFT...WITH DIURNAL WINDS GENERALLY UNDER 12 KTS. SCT TSRA/-SHRA WILL
AGAIN BE POSSIBLE AFTER 19/20Z NEAR MOST TERMINALS. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE THIS AFTERNOON AND EVENING...WITH A FOCUS SOUTH AND EAST OF
TUCSON. SCATTERED ACTIVITY WILL THEN SPREAD ACROSS MUCH OF SOUTHEAST
ARIZONA MONDAY AND TUESDAY BEFORE A WARMING AND DRYING TREND LIMITS
ACTIVITY FOR THE LATTER PART OF THE WEEK. HOWEVER...THERE WILL STILL
BE ENOUGH MOISTURE FOR ISOLATED TO SCATTERED THUNDERSTORMS OVER THE
WHITE MOUNTAINS AND IN THE HIGHER ELEVATIONS SOUTH OF TUCSON.
OUTSIDE OF THUNDERSTORM WIND GUSTS...20-FT WINDS WILL GENERALLY BE
LIGHT AND DIURNAL AT LESS THAN 15 MPH. HOWEVER...THERE WILL STILL BE
SOME OCCASIONAL AFTERNOON AND EARLY EVENING GUSTINESS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...MOLLERE
AVIATION/FIRE WEATHER...HUMPHREYS
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
908 AM MST SUN AUG 9 2015
.SYNOPSIS...
STORM CHANCES WILL WANE WITH WARMING TEMPERATURES ACROSS THE ENTIRE
AREA TODAY AS DRIER AIR MOVES INTO THE AREA THROUGH THE BEGINNING OF
THE WEEK. A RETURN TO A MORE TYPICAL MONSOON FLOW WILL OCCUR BY THE
MIDDLE OF THE WEEK...ALTHOUGH DRIER AIR SHOULD ONCE AGAIN OVERSPREAD
THE AREA THURSDAY INTO NEXT WEEKEND.
&&
.DISCUSSION...
RELATIVELY SHARP MOISTURE GRADIENT PERSISTS ACROSS THE AREA WITH
SURFACE DEWPOINTS IN THE LOWER 40S ALONG THE CO RIVER VALLEY AND MID
TO UPPER 60S IN THE PHOENIX AREA. MORNING PSR SOUNDING AND TEMPE GPS-
IPW MEASURED A PWAT OF 1.5 INCHES...WHICH IS NEAR THE CLIMATOLOGICAL
MEAN.
LATEST CAMS INCLUDING THE HRRR CONTINUE TO SUGGEST THAT CONVECTION
WILL BE MOST CONCENTRATED ACROSS EASTERN AZ THIS AFTERNOON.
MEANWHILE...WARMING TREND WILL CONTINUE WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES EXPECTED. ONLY MINOR ADJUSTMENTS TO THE SHORT-TERM
TEMPERATURES ARE ANTICIPATED THIS MORNING.
&&
.PREVIOUS DISCUSSION...
EARLY MORNING WATER VAPOR IMAGERY AND UPPER AIR DATA CONTINUE TO
DEPICT BROAD SOUTHWESTERLY FLOW ACROSS THE REGION...WITH A SHARP
MOISTURE GRADIENT STRETCHING FROM THE FOUR CORNERS THROUGH PHOENIX
AND INTO THE GULF OF CALIFORNIA. PWATS PER BLENDED TPW IMAGERY ARE
GENERALLY AROUND 0.5-0.6 INCHES ACROSS SOUTHEAST CALIFORNIA AND
CLOSER TO 1.4-1.5 ALONG THE ARIZONA/NEW MEXICO BORDER. NOT
SURPRISINGLY MOST OF THE STORM ACTIVITY ON SATURDAY WAS CONFINED TO
THE MOISTURE-RICH AREAS SOUTH/EAST OF PHOENIX. STORMS HAVE LONG SINCE
DIED OUT WITH MOSTLY CLEAR SKIES PREVALENT ACROSS THE REGION AS OF
08Z.
THE WEST-TO-EAST DRYING TREND WILL CONTINUE TODAY WITH DRY AIR
EVENTUALLY FORECAST TO SPREAD ALL THE WAY TO GILA COUNTY THIS
AFTERNOON. HARD TO IMAGINE THAT THERE WON`T BE AT LEAST SOME STORM
ACTIVITY EAST OF PHOENIX TODAY...SPC SSEO AND NCAR HI-RES ENSEMBLE
SUGGEST A FEW SHOWERS. MAINTAINING 10-20 POPS EAST OF PHOENIX THIS
AFTERNOON AND EVENING FOR THAT REASON.
LOOKING AHEAD TO MONDAY...THE MID LEVEL 700-300MB STEERING FLOW WILL
BEGIN TO TAKE ON A MORE TYPICAL MONSOONAL PATTERN WITH WEAK MOISTURE
ADVECTION EXPECTED TO COMMENCE MONDAY AFTERNOON. GLOBAL MODELS AND
CONVECTIVE ALLOWING MODELS SUGGEST THE MAJORITY OF THE STORM ACTIVITY
WILL BE CONFINED TO THE MOUNTAINS EAST OF PHOENIX MONDAY AFTERNOON
AND THIS SEEMS REASONABLE. TUESDAY COULD BE A BIT MORE ACTIVE AS
DEEPER MOISTURE IS FORECAST TO MOVE INTO THE AREA FROM THE SOUTHEAST.
THIS INFLUX OF MOISTURE WILL ALSO ARRIVE COINCIDENT WITH THE PASSAGE
OF AN UPPER LEVEL PV ANOMALY AS WELL AS AN INVERTED MID LEVEL TROUGH.
BOTH GFS/EC INDICATE THESE FEATURES AND THEY`RE ALSO BEING REFLECTED
IN SOME OF THE LONGER-RANGE HI-RES GUIDANCE. MADE SOME MINOR UPWARD
ADJUSTMENTS TO POPS FOR TUESDAY/TUESDAY NIGHT ACCORDINGLY. OF
COURSE...JUST HOW ACTIVE TUESDAY IS WILL DICTATE HOW ACTIVE WEDNESDAY
WILL BE AS CONDITIONS WILL REMAIN FAIRLY UNCHANGED. STICKING WITH THE
IDEA OF A DOWN DAY CONVECTIVELY ON WEDNESDAY ALTHOUGH NOT NEARLY
CONFIDENT ENOUGH TO CUT BACK POPS. STICKING WITH A BROAD-BRUSHED
10-20 POP FORECAST FOR ALL LOCATIONS ON WEDNESDAY AT THIS POINT AND
THIS SEEMS SUPPORTED BY THE ENSEMBLES.
DRY ADVECTION STILL LOOKS LIKELY LATER IN THE WEEK AS THE BOUNDARY
LAYER SEES MIXING RATIOS FALL TO 4-5 G/KG THURSDAY AND FRIDAY
COURTESY OF EASTERLY FLOW VS. SOUTHEASTERLY FLOW. NOT ONLY WILL THIS
SERVE TO REDUCE RAINFALL CHANCES...BUT IT WILL ALSO LEAD TO
INCREASING TEMPERATURES LATE IN THE WEEK. LATEST BLENDED GUIDANCE IS
SUGGESTING DESERT HIGHS IN THE 110-113 RANGE LATE IN THE WEEK AND
OUR FORECAST HIGHS WERE RAISED A FEW DEGREES. IF THIS TREND CONTINUES
AND/OR EVEN DRIER AIR IS ADVECTED INTO THE AREA...MAY NEED TO LOOK AT
EXCESSIVE HEAT WARNINGS FOR PORTIONS OF THE FORECAST AREA. SOME
MOISTURE WILL RETURN BY NEXT WEEKEND...PUTTING THE BRAKES ON THE
WARMING TREND.
&&
.AVIATION......SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND
KSDL...
DRY SOUTHWESTERLY FLOW ALOFT WILL KEEP THUNDERSTORM ACTIVITY WELL
OFF TO THE EAST AND CLOUD COVERAGE DOWN INTO THE FEW-SCT RANGE
THROUGH THE TAF PERIOD WITH CLOUD BASES REMAINING MAINLY AOA 10K
FEET. WINDS TO REMAIN MAINLY ON THE LIGHT SIDE THROUGH THE TAF
PERIOD...MAINLY AOB 8 KTS...MAINLY FOLLOWING TYPICAL DIURNAL TRENDS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DRY SOUTHWESTERLY FLOW ALOFT TO KEEP SKIES MAINLY CLEAR THROUGH THE
TAF PERIOD. WINDS TO REMAIN MAINLY FROM A SOUTHERLY DIRECTION AT
KBLH AND FOLLOW TYPICAL DIURNAL TRENDS AT KIPL.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A SUBTLE RETURN OF MONSOON MOISTURE COUPLED WITH SOME PASSING UPPER
LEVEL DISTURBANCES FROM THE SOUTHEAST WILL RAISE STORM CHANCES AND
HUMIDITIES FOR TUESDAY. STORM CHANCES WILL EXPAND OUT OF THE EASTERN
AZ HIGHER TERRAIN THROUGH THE LOWER DESERT LOCALES AND TOWARDS THE
CO RIVER VALLEY. CONDITIONS DRY OUT AGAIN BY THE MIDDLE PART OF THE
WEEK AND DAYTIME TEMPERATURES RESPOND IN KIND...WITH THE POTENTIAL
TO GO ABOVE SEASONALLY NORMAL READINGS. WINDS WILL BE LIGHT THROUGH
MUCH OF THE PERIOD FOLLOWING TYPICAL DIURNAL DIRECTIONS EXCEPT FOR
AFTERNOON UPSLOPE BREEZES GUSTING AT TIMES UP TO 20 MPH.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
852 PM MDT MON AUG 10 2015
.UPDATE...
ISSUED AT 840 PM MDT MON AUG 10 2015
MCS LOCATED IN PUEBLO AND CROWLEY COUNTIES WILL CONTINUE TO
SLOWLY MOVE OFF TO THE ESE OVER THE NEXT FEW HOURS AS DEEP LOW
LEVEL MOISTURE AND LOW LEVEL MOISTURE CONVERGENCE HELP FUEL THE
STORM SYSTEM. RAISED POPS ACROSS CENTRAL AND SAN JUANS MTNS AS 00Z
NAM TRENDED TOWARDS ENHANCED ACTIVITY OVERNIGHT ACROSS THE HIGHER
TERRAIN. OTHERWISE CURRENT FORECAST REMAINS ON TRACK. LUKINBEAL
UPDATE ISSUED AT 537 PM MDT MON AUG 10 2015
THE THREAT OF FLASH FLOODING WILL CONTINUE ACROSS THE I-25
CORRIDOR THROUGH THE LATE EVENING HOURS AS A LINE OF TSRA
CURRENTLY EXTENDS FROM NE EL PASO COUNTY THROUGH WESTERN FREMONT
COUNTY WILL SLOWLY MOVE ESE OVER THE NEXT SEVERAL HOURS. LOW LEVEL
CONVERGENCE ALONG TWO OUTFLOW BOUNDARIES IN FAR SE EL PASO COUNTY
MAY INTENSIFY ACTIVITY FURTHER ALONG THE TSRA LINE. LATEST RUNS OF
THE HRRR CONTINUE TO BRING MODERATE TO HEAVY RAINFALL INTO EL
PASO...PUEBLO...CROWLEY...AND OTERO COUNTIES BETWEEN 01-06Z
TONIGHT. DEEP MOISTURE IS IN PLACE ACROSS THE PLAINS WITH PWATS
RANGING FROM 1.2-1.6 INCHES WITH DEW POINTS IN THE LOW 60S. WARM
RAIN PROCESSES IN THE LOWEST 100 MB WILL CONTINUE TO PROMOTE THE
DEVELOPMENT OF HEAVY RAINFALL THROUGH 06Z THIS EVENING ACROSS THE
PLAINS. ANOTHER POTENTIAL AREA OF CONCERN OVERNIGHT WILL BE THE
SAN LUIS VALLEY...SAN JUANS...AND CENTRAL MTNS WHERE AN UPPER
LEVEL DISTURBANCE IN COMBINATION WITH HIGH LOW-MID LEVEL MOISTURE
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS WITH THE POTENTIAL TO
PRODUCE HEAVY RAINFALL. RAINFALL RATES WILL DECREASE AFTER 06Z AS
CLOUD TOPS LOWER ACROSS THE CWA DUE TO UPPER LEVEL SUBSIDENCE
MOVING OVERHEAD...DIMINISHING THE POTENTIAL FOR FLASH FLOODING.
LUKINBEAL
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
TSRA MOST NUMEROUS THIS AFTERNOON OVER THE PLAINS SOUTH OF THE
ARKANSAS RIVER...THOUGH AN ISOLATED CELL OVER TELLER AND EL PASO
COUNTIES EARLIER IN THE DAY MANAGED TO PRODUCE FLASH FLOODING OVER
WESTERN PORTIONS OF COLORADO SPRINGS AND THE EASTERN EDGE OF THE
WALDO CANYON BURN SCAR. MAIN QUESTION FOR TONIGHT WILL REVOLVE
AROUND LOCATION OF HEAVIER RAINFALL AND HOW LATE WILL STORMS
PERSIST INTO TUE MORNING. 19Z/20Z RUNS OF THE HRRR BRING ANOTHER
WAVE OF TSRA AND HEAVY RAIN THROUGH EL PASO COUNTY 00Z-02Z...THEN
ACROSS PUEBLO COUNTY AND NORTHERN PORTIONS OF THE ARKANSAS VALLEY
02Z-05Z. 12Z VERSIONS OF THE NAM/NAM 4KM/NSSL WRF ON THE OTHER
HAND...KEEP HEAVIEST RAINFALL MAINLY OVER THE MOUNTAINS
OVERNIGHT...WITH FOCUS FOR MOST TSRA SHIFTING TOWARD THE SAN JUAN
MOUNTAINS AFTER 06Z AS AREA OF DEEP TROPICAL MOISTURE OVER THE 4
CORNERS ROTATES NORTHEASTWARD. FORECAST LEANS A LITTLE TOWARD THE
HRRR...AS LAPS CAPES ARE STILL ABOVE 1000 J/KG OVER THE EASTERN
MOUNTAINS AND I-25 CORRIDOR...SUGGESTING ANOTHER BOUT OF TSRA IS
POSSIBLE. CONSIDERED A FLASH FLOOD WATCH FOR EL PASO COUNTY FOR
THIS EVENING AS HEAVY RAIN HAS FALLEN ACROSS THE REGION...THOUGH
WITH HRRR SHIFTING AXIS OF STRONGER STORMS SOUTH FAIRLY
QUICKLY...WILL REFRAIN FROM ISSUANCE AT THIS POINT. POCKETS OF
HEAVY RAIN LOOK POSSIBLE FARTHER SOUTH OVER THE PLAINS...BUT MOST
AREAS HAVE BEEN DRY ENOUGH LATELY TO TAKE AT LEAST A COUPLE HOURS
OF HEAVER PRECIP. PRECIP SLOWLY WANES OVERNIGHT...BUT NEVER
COMPLETELY COMES TO AN END...SO WILL KEEP SOME POPS GOING MANY
AREAS INTO EARLY TUE MORNING.
ON TUE...MOISTURE REMAINS IN PLACE...THOUGH HEIGHTS BEGIN TO BUILD
SLIGHTLY AS UPPER HIGH STARTS ITS NORTHWARD EXPANSION. STILL
APPEARS MOST LOCATIONS WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE AGAIN...THOUGH EXTENT OF OVERNIGHT CONVECTION
AND POTENTIAL MCS OVER THE EASTERN PLAINS/NERN NM WILL LIKELY PLAY
A ROLE IN AMOUNT OF CONVECTIVE COVERAGE...ESPECIALLY OVER THE
PLAINS WHERE EARLY MORNING SHOWERS COULD LIMIT INSTABILITY. BROAD-
BRUSH OF SCATTERED POPS LOOKS FINE...AND WITH MOISTURE LEVELS
REMAINING RELATIVELY HIGH...LOCALLY HEAVY RAINFALL WILL AGAIN BE
POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
UPPER RIDGE EXPANDS NORTHWARD WED-FRI...WITH THE UPPER LEVEL HIGH
PRESSURE CENTER REMAINING ALONG THE CO/NM BORDER THROUGH THE
PERIOD. TRAPPED MOISTURE UNDER THE HIGH WILL CONTINUE TO BE
RECYCLED...WITH DAILY AFTERNOON/EVENING TSRA OVER THE
MOUNTAINS...THOUGH COVERAGE MAY BECOME RATHER SPARSE WED/THU AS
TEMPERATURES ALOFT WARM. PLAINS/VALLEY TSRA CHANCES LOOK FAIRLY
LOW...THOUGH TOUGH TO RULE OUT A COUPLE STORMS DRIFTING AWAY FROM
THE MOUNTAINS EACH DAY...ESPECIALLY ALONG AND WEST OF I-25.
FORECAST HAS LOW POPS FOR ALL AREAS EACH DAY WED-FRI...WHICH MAY
BE A LITTLE OVERDONE...BUT WILL RUN WITH FOR NOW. RIDGE FLATTENS
SLIGHTLY FRI INTO THE WEEKEND...WHILE WEAK FRONT OOZES INTO THE
EASTERN PLAINS LATE SUN. EXPECT A GRADUAL INCREASE IN TSRA CHANCE
MOST LOCATIONS AS SLIGHTLY DEEPER MOISTURE MOVES IN FROM THE
WEST...WHILE LOW LEVELS ON THE PLAINS MOISTEN AND WLY STEERING
CURRENTS BECOME MORE FAVORABLE FOR STORMS TO MOVE ONTO THE PLAINS.
TEMPS FROM WED INTO THE WEEKEND WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 235 PM MDT MON AUG 10 2015
SCATTERED TO NUMEROUS TSRA WERE OVER THE AREA THIS AFTERNOON WITH
THE GREATEST COVERAGE OF STORMS SOUTH OF THE ARKANSAS RIVER. WHILE
KPUB AND KCOS ARE CURRENTLY FREE OF CONVECTION AS OF
21Z...MESOSCALE MODELS INDICATE ANOTHER ROUND OF TSRA DROPPING
SOUTH THROUGH KCOS 00Z-02Z...THEN THROUGH KPUB 01Z-03Z...SO WILL
MAINTAIN A VCTS MENTION BOTH SITES UNTIL AROUND 03Z. AT
KALS...WILL ALSO KEEP VCTS IN THE TAF INTO THE EVENING AS
WELL...WITH STORMS ENDING 01-03Z. OVERNIGHT...TSRA MAY LINGER OVER
THE PLAINS EAST OF I-25 MUCH OF THE NIGHT...WITH A THREAT OF
SHOWERS AT TAF SITES 03Z-09Z. ON TUESDAY...TSRA WILL DEVELOP LATE
MORNING OVER THE MOUNTAINS...THEN SPREAD TO LOWER
ELEVATIONS...INCLUDING ALL TAF SITES IN THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/LW
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
607 PM MDT MON AUG 10 2015
.UPDATE...
ISSUED AT 537 PM MDT MON AUG 10 2015
THE THREAT OF FLASH FLOODING WILL CONTINUE ACROSS THE I-25
CORRIDOR THROUGH THE LATE EVENING HOURS AS A LINE OF TSRA
CURRENTLY EXTENDS FROM NE EL PASO COUNTY THROUGH WESTERN FREMONT
COUNTY WILL SLOWLY MOVE ESE OVER THE NEXT SEVERAL HOURS. LOW LEVEL
CONVERGENCE ALONG TWO OUTFLOW BOUNDARIES IN FAR SE EL PASO COUNTY
MAY INTENSIFY ACTIVITY FURTHER ALONG THE TSRA LINE. LATEST RUNS OF
THE HRRR CONTINUE TO BRING MODERATE TO HEAVY RAINFALL INTO EL
PASO...PUEBLO...CROWLEY...AND OTERO COUNTIES BETWEEN 01-06Z
TONIGHT. DEEP MOISTURE IS IN PLACE ACROSS THE PLAINS WITH PWATS
RANGING FROM 1.2-1.6 INCHES WITH DEW POINTS IN THE LOW 60S. WARM
RAIN PROCESSES IN THE LOWEST 100 MB WILL CONTINUE TO PROMOTE THE
DEVELOPMENT OF HEAVY RAINFALL THROUGH 06Z THIS EVENING ACROSS THE
PLAINS. ANOTHER POTENTIAL AREA OF CONCERN OVERNIGHT WILL BE THE
SAN LUIS VALLEY...SAN JUANS...AND CENTRAL MTNS WHERE AN UPPER
LEVEL DISTURBANCE IN COMBINATION WITH HIGH LOW-MID LEVEL MOISTURE
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS WITH THE POTENTIAL TO
PRODUCE HEAVY RAINFALL. RAINFALL RATES WILL DECREASE AFTER 06Z AS
CLOUD TOPS LOWER ACROSS THE CWA DUE TO UPPER LEVEL SUBSIDENCE
MOVING OVERHEAD...DIMINISHING THE POTENTIAL FOR FLASH FLOODING.
LUKINBEAL
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
TSRA MOST NUMEROUS THIS AFTERNOON OVER THE PLAINS SOUTH OF THE
ARKANSAS RIVER...THOUGH AN ISOLATED CELL OVER TELLER AND EL PASO
COUNTIES EARLIER IN THE DAY MANAGED TO PRODUCE FLASH FLOODING OVER
WESTERN PORTIONS OF COLORADO SPRINGS AND THE EASTERN EDGE OF THE
WALDO CANYON BURN SCAR. MAIN QUESTION FOR TONIGHT WILL REVOLVE
AROUND LOCATION OF HEAVIER RAINFALL AND HOW LATE WILL STORMS
PERSIST INTO TUE MORNING. 19Z/20Z RUNS OF THE HRRR BRING ANOTHER
WAVE OF TSRA AND HEAVY RAIN THROUGH EL PASO COUNTY 00Z-02Z...THEN
ACROSS PUEBLO COUNTY AND NORTHERN PORTIONS OF THE ARKANSAS VALLEY
02Z-05Z. 12Z VERSIONS OF THE NAM/NAM 4KM/NSSL WRF ON THE OTHER
HAND...KEEP HEAVIEST RAINFALL MAINLY OVER THE MOUNTAINS
OVERNIGHT...WITH FOCUS FOR MOST TSRA SHIFTING TOWARD THE SAN JUAN
MOUNTAINS AFTER 06Z AS AREA OF DEEP TROPICAL MOISTURE OVER THE 4
CORNERS ROTATES NORTHEASTWARD. FORECAST LEANS A LITTLE TOWARD THE
HRRR...AS LAPS CAPES ARE STILL ABOVE 1000 J/KG OVER THE EASTERN
MOUNTAINS AND I-25 CORRIDOR...SUGGESTING ANOTHER BOUT OF TSRA IS
POSSIBLE. CONSIDERED A FLASH FLOOD WATCH FOR EL PASO COUNTY FOR
THIS EVENING AS HEAVY RAIN HAS FALLEN ACROSS THE REGION...THOUGH
WITH HRRR SHIFTING AXIS OF STRONGER STORMS SOUTH FAIRLY
QUICKLY...WILL REFRAIN FROM ISSUANCE AT THIS POINT. POCKETS OF
HEAVY RAIN LOOK POSSIBLE FARTHER SOUTH OVER THE PLAINS...BUT MOST
AREAS HAVE BEEN DRY ENOUGH LATELY TO TAKE AT LEAST A COUPLE HOURS
OF HEAVER PRECIP. PRECIP SLOWLY WANES OVERNIGHT...BUT NEVER
COMPLETELY COMES TO AN END...SO WILL KEEP SOME POPS GOING MANY
AREAS INTO EARLY TUE MORNING.
ON TUE...MOISTURE REMAINS IN PLACE...THOUGH HEIGHTS BEGIN TO BUILD
SLIGHTLY AS UPPER HIGH STARTS ITS NORTHWARD EXPANSION. STILL
APPEARS MOST LOCATIONS WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE AGAIN...THOUGH EXTENT OF OVERNIGHT CONVECTION
AND POTENTIAL MCS OVER THE EASTERN PLAINS/NERN NM WILL LIKELY PLAY
A ROLE IN AMOUNT OF CONVECTIVE COVERAGE...ESPECIALLY OVER THE
PLAINS WHERE EARLY MORNING SHOWERS COULD LIMIT INSTABILITY. BROAD-
BRUSH OF SCATTERED POPS LOOKS FINE...AND WITH MOISTURE LEVELS
REMAINING RELATIVELY HIGH...LOCALLY HEAVY RAINFALL WILL AGAIN BE
POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
UPPER RIDGE EXPANDS NORTHWARD WED-FRI...WITH THE UPPER LEVEL HIGH
PRESSURE CENTER REMAINING ALONG THE CO/NM BORDER THROUGH THE
PERIOD. TRAPPED MOISTURE UNDER THE HIGH WILL CONTINUE TO BE
RECYCLED...WITH DAILY AFTERNOON/EVENING TSRA OVER THE
MOUNTAINS...THOUGH COVERAGE MAY BECOME RATHER SPARSE WED/THU AS
TEMPERATURES ALOFT WARM. PLAINS/VALLEY TSRA CHANCES LOOK FAIRLY
LOW...THOUGH TOUGH TO RULE OUT A COUPLE STORMS DRIFTING AWAY FROM
THE MOUNTAINS EACH DAY...ESPECIALLY ALONG AND WEST OF I-25.
FORECAST HAS LOW POPS FOR ALL AREAS EACH DAY WED-FRI...WHICH MAY
BE A LITTLE OVERDONE...BUT WILL RUN WITH FOR NOW. RIDGE FLATTENS
SLIGHTLY FRI INTO THE WEEKEND...WHILE WEAK FRONT OOZES INTO THE
EASTERN PLAINS LATE SUN. EXPECT A GRADUAL INCREASE IN TSRA CHANCE
MOST LOCATIONS AS SLIGHTLY DEEPER MOISTURE MOVES IN FROM THE
WEST...WHILE LOW LEVELS ON THE PLAINS MOISTEN AND WLY STEERING
CURRENTS BECOME MORE FAVORABLE FOR STORMS TO MOVE ONTO THE PLAINS.
TEMPS FROM WED INTO THE WEEKEND WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 235 PM MDT MON AUG 10 2015
SCATTERED TO NUMEROUS TSRA WERE OVER THE AREA THIS AFTERNOON WITH
THE GREATEST COVERAGE OF STORMS SOUTH OF THE ARKANSAS RIVER. WHILE
KPUB AND KCOS ARE CURRENTLY FREE OF CONVECTION AS OF
21Z...MESOSCALE MODELS INDICATE ANOTHER ROUND OF TSRA DROPPING
SOUTH THROUGH KCOS 00Z-02Z...THEN THROUGH KPUB 01Z-03Z...SO WILL
MAINTAIN A VCTS MENTION BOTH SITES UNTIL AROUND 03Z. AT
KALS...WILL ALSO KEEP VCTS IN THE TAF INTO THE EVENING AS
WELL...WITH STORMS ENDING 01-03Z. OVERNIGHT...TSRA MAY LINGER OVER
THE PLAINS EAST OF I-25 MUCH OF THE NIGHT...WITH A THREAT OF
SHOWERS AT TAF SITES 03Z-09Z. ON TUESDAY...TSRA WILL DEVELOP LATE
MORNING OVER THE MOUNTAINS...THEN SPREAD TO LOWER
ELEVATIONS...INCLUDING ALL TAF SITES IN THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/LW
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION...CORRECTED
NWS GRAND JUNCTION CO
303 PM MDT SUN AUG 9 2015
CORRECTED WORDING IN LONG TERM
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 302 PM MDT SUN AUG 9 2015
SIGNIFICANTLY DRIER AIR WILL REMAIN OVER THE AREA OVERNIGHT. THE
12Z KGJT SOUNDING HAD PRECIPITABLE WATER OF 0.63 IN. DEWPOINTS
WILL CONTINUE TO DROP INTO THE 40S AND EVEN UPPER 30S AT SOME
LOCATIONS. CAPE VALUES ARE PROJECTED IN THE RAP13 AND HRRR TO
REMAIN LOW AS WELL...SO CONVECTION EARLY THIS EVENING WILL BE
WEAK AND ONLY OVER AND DOWNWIND OF RIDGES. ONLY LIGHT
PRECIPITATION IS EXPECTED WITH THESE STORMS ALONG WITH GUSTY
WINDS. THUNDERSTORMS SHOULD DISSIPATE WELL BEFORE MIDNIGHT WITH
NEARLY CLEAR SKIES EXPECTED AGAIN OVERNIGHT.
MOISTURE BEGINS TO INCREASE FROM THE SOUTH AGAIN ON MONDAY...SO EXPECTING
SCATTERED ACTIVITY IN THE SAN JUANS MONDAY EVENING AS THE 12Z NAM
AND GFS INDICATE A H5 VORTICITY MAX REACHING THE FOUR CORNERS
MONDAY EVENING. THE EURO IS A BIT SLOWER WITH THIS ENERGY...BUT IN
ANY CASE IT DOES LOOK LIKE SHOWERS AND ISO TSTORMS WILL CONTINUE
THROUGH THE OVERNIGHT HOURS ON MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 302 PM MDT SUN AUG 9 2015
TUESDAY MORNING WILL BE A MUGGY ONE...WITH CLOUD COVER AND RAIN
SHOWERS ACROSS MUCH OF THE REGION BY MIDDAY. MONSOONAL MOISTURE
WILL BE AT ITS HIGHEST THIS WEEK ON TUESDAY AFTERNOON AS
PRECIPITABLE WATER VALUES ACROSS THE FOUR CORNERS REACH UPWARDS OF
1.2 INCHES AND MORE THAN 0.75 INCHES REACHING THE UT/CO/WY BORDER.
THOUGH DEEP MOISTURE WILL BE IN PLACE...NOT FEELING VERY CONFIDENT
ON THE THREAT OF FLASH FLOODING SINCE WE WILL LIKELY BE DEALING
WITH WIDESPREAD CLOUD COVER AGAIN AND LACK OF LIFTING DUE TO
DAYTIME HEATING. LOCALIZED FLASH FLOODING COULD OCCUR IF THERE IS
SOME CLEARING WHICH PRODUCES ENOUGH LIFT FOR MORE VERTICALLY
SUPPORTED THUNDERSTORMS. WEDNESDAY WILL LIKELY BE MORE OF A THREAT
DAY FOR FLASH FLOODING WITH SKY CONDITIONS LESS CLOUDY BUT WITH
DEEP MOISTURE STILL IN PLACE. FORECAST CONVECTIVE INDICES ON THE
NAM ARE MORE FAVORABLE FOR HEAVY RAIN PRODUCING THUNDERSTORMS ON
WEDNESDAY THAN TUESDAY...SO THESE DAYS WILL NEED TO BE WATCHED FOR
POTENTIAL IMPACTS. THE LACK OF JET SUPPORT WILL KEEP STEERING
WINDS LIGHT THROUGH THE END OF THE WEEK SO ANY SHOWERS AND STORMS
WHICH DEVELOP WILL MOVE SLOWLY. SOME DRYING OCCURS LATER IN THE
WORK WEEK DUE TO HIGH PRESSURE AMPLIFYING OVER THE ROCKIES...BUT
PRECIPITABLE WATER VALUES REMAIN NEAR THREE QUARTERS OF AN INCH
SO DIURNALLY INDUCED SHOWERS AND THUNDERSTORMS WILL DEVELOP
EVERYDAY OVER HIGHER TERRAIN.
NEXT SATURDAY...A TROUGH OVER THE PACIFIC NORTHWEST IS PROGGED TO MOVE
INLAND NORTH OF COLORADO. THE INTERACTION OF THIS TROUGH WITH THE
HIGH PRESSURE IN PLACE OVER THE ROCKIES WILL DRIVE A 50 KT JET
INTO NE UTAH AND NW COLORADO AND POTENTIALLY CREATE MORE
CONVECTIVE ACTIVITY UP NORTH NEXT WEEKEND.
BUMPED HIGH TEMPS UP A COUPLE OF DEGREES IN THE LOWER VALLEYS
TOWARD THE END OF THE WEEK CLOSER TO MOS GUIDANCE FOR A MIDDLE
GROUND SOLUTION. FEEL THAT MOS GUIDANCE IS TOO HOT BUT PREVIOUS
FORECAST WAS TOO LOW CONSIDERING THE EXPECTED AMOUNT OF SUNSHINE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 302 PM MDT SUN AUG 9 2015
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES THE NEXT 24 HOURS.
THROUGH ABOUT 02Z ISOLATED THUNDERSTORMS WILL CONTINUE OVER THE
MOUNTAINS OF NORTHERN AND CENTRAL COLORADO...AND EASTERN UTAH...
WITH SCATTERED STORMS OVER THE SAN JUAN MOUNTAINS. LOCAL MODERATE
RAIN SHOWERS AND WIND GUSTS TO 35 MPH ARE POSSIBLE IN THE VICINITY
OF THESE STORMS. AREAL COVERAGE OF THUNDERSTORMS WILL INCREASE A
BIT MONDAY AFTERNOON OVER SOUTHWEST COLORADO AND CENTRAL COLORADO
NEAR THE CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...CC/JAM
LONG TERM...JAM
AVIATION...CC
AREA FORECAST DISCUSSION
NWS TAUNTON MA
139 AM EDT SUN AUG 9 2015
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN DRY WEATHER THROUGH SUN AS LOW
PRESSURE REMAINS WELL OFFSHORE...THOUGH A SPOT SHOWER IS POSSIBLE
ACROSS THE INTERIOR SUN AFTERNOON. LOW PRESSURE WILL RESULT IN
SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES MON NIGHT INTO WED
MORNING. A TREND TOWARD DRIER WEATHER IS LIKELY THROUGH THE
REMAINDER OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
10 PM UPDATE...
LITTLE ADDITIONAL CHANGES NECESSARY WITH THIS UPDATE. IN SPITE OF
THE CLOUD COVER SEVERAL LOCATIONS ARE ALREADY MAKING A RUN INTO
THE MID 60S. DWPTS ACROSS THE REGION ARE AS LOW AS THE LOW-MID
50S SO THERE IS MORE ROOM TO DROP THROUGH THE OVERNIGHT HOURS.
THEREFORE...DID LOWER MINS BY A BIT...BUT THAT WAS THE ONLY REAL
CHANGE.
315 PM UPDATE...
PLENTY OF DIURNAL CU ACROSS INTERIOR WHERE HRRR AND 12Z NAM WANT
TO BRING SOME ISOLATED SHOWER ACTIVITY THIS AFTERNOON. COLUMN IS
FAIRLY DRY SO AM NOT BUYING INTO THAT...MODELS ARE MORE LIKELY
INDICATING BUILDING CU WHICH IS EVIDENT ON SATELLITE NEAR
BERKSHIRES.
MEANWHILE COASTAL LOW IS THROWING BACK SOME PATCHY MID AND HIGH
CLOUDS ALONG S COAST...CAPE COD AND ISLANDS. EXPECT THESE CLOUDS
TO THICKEN UP TONIGHT BUT NO RAIN EXPECTED AS BEST LIFT STAYS
OFFSHORE WITH PROGRESSIVE UPPER FLOW. SOME OF HIGH-RES MODELS
/HRRR...RAP AND ARW-WRF/ WANT TO BRING RAINFALL TO SE NEW ENGLAND
LATER TONIGHT BUT THAT LOOKS TO BE OVERDONE.
ANOTHER PLEASANTLY COOL NIGHT AHEAD WITH GOOD RADIATIONAL COOLING
CONDITIONS AWAY FROM INFLUENCE OF MID/HIGH CLOUDS NEAR S COAST.
LEANED TOWARD COOLER GFS LAMP GUIDANCE WHICH BRINGS LOWS INTO
UPPER 40S ACROSS NW MA AND MAINLY 50S ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
EXPECTING A GOOD AMOUNT OF CLOUDINESS NEAR CAPE COD AND ISLANDS
SUN DUE TO INCREASING NE FLOW ON PERIPHERY OF COASTAL LOW. MODEL
CROSS SECTIONS SHOW GOOD AMOUNT OF LOW LEVEL MOISTURE BELOW 950 MB
WHICH SHOULD BECOME TRAPPED. NO REAL MECHANISM FOR RAINFALL SO DRY
WEATHER ANTICIPATED AS DEEPER MOISTURE AND LIFT REMAIN WELL
OFFSHORE. SOME QUESTION AS TO WHETHER OR NOT LOW CLOUDS WILL BREAK
DURING AFTERNOON...BUT FOR NOW LEANED TOWARD THEM HANGING ON.
ACROSS INTERIOR...MODELS CONTINUE TO HINT AT POSSIBILITY OF FEW
SHOWERS BY AFTERNOON DUE TO SUBTLE LIFT FROM UPPER TROUGH. LOW
LEVEL CONVERGENCE IS MINIMAL DUE TO WEAK WIND FIELDS...SO ANY
ACTIVITY WOULD BE TIED TO TERRAIN. STABILITY PARAMETERS MARGINAL
SO EXPECT AN ISOLATED SHOWER OR PERHAPS A THUNDERSTORM ACROSS NW
AND POSSIBLY N CENTRAL MA.
HIGHS SHOULD BE A LITTLE COOLER THAN TODAY...ESPECIALLY NEAR COAST
DUE TO NE FLOW AND CLOUDINESS...RANGING FROM AROUND 70 ON OUTER
CAPE TO AROUND 80 FARTHER INLAND.
SUBSIDENCE AND SOME DRYING SUN NIGHT SHOULD LEAD TO AT LEAST
PARTIAL CLEARING...BUT CONTINUED ONSHORE FLOW MAY KEEP CLOUDS
LOCKED IN CLOSER TO COAST. LOWS SHOULD DROP BACK INTO 50S AND
LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* UNSETTLED WEATHER LIKELY LATE MON NIGHT THROUGH WED MORNING
* TEMPS SLIGHTLY BELOW NORMAL FOR MUCH OF THE WEEK
* POSSIBLE RETURN TO AUGUST HEAT FOR SATURDAY
OVERALL...MODELS ARE IN DECENT AGREEMENT THROUGH MUCH OF THE LONG
TERM. THERE ARE A COUPLE OF DISCREPANCIES THAT CONTINUE THROUGH THE
PERIOD. AS FAR AS SENSIBLE WEATHER GOES...THE MODELS ARE IN
AGREEMENT. LOOKING AT AN UPPER LEVEL TROUGH IN THE GREAT LAKES
MONDAY SLOWLY MOVING EASTWARD OVER THE NORTHEAST AND NEW ENGLAND BY
WEDNESDAY AND POTENTIALLY STALLING THERE THROUGH THE END OF THE
FORECAST PERIOD. THE ECMWF KEEPS THE PATTERN MORE AMPLIFIED...WHILE
THE GFS HAS A FLATTER FLOW AT THE MID-LEVELS WITH THE TROUGH
RETREATING INTO SOUTHEASTERN CANADA.
THIS TROUGH RESULTS IN LOW PRESSURE DEVELOPING IN THE GREAT LAKES
AND MOVING INTO QUEBEC TUESDAY. THE ECMWF PRODUCES A TRIPLE POINT
LOW OVER NEW JERSEY OFF THE MAIN LOW IN QUEBEC AND TRANSLATES THE
TRIPLE POINT LOW ALONG THE SOUTHERN NEW ENGLAND COAST. THE GFS
DEPICTS NO SUCH REDEVELOPMENT BUT KEEPS A STRONG SOUTHERLY FLOW
AHEAD OF THE COLD FRONT EXTENDING FROM THE QUEBEC LOW. THESE
DIFFERENCES COULD AFFECT THE OVERALL NATURE OF THE RAIN /WHETHER ITS
MORE STRATIFORM OR SHOWERY/ BUT REGARDLESS OF THE NATURE OR THE TYPE
OF SYSTEM...TUESDAY IS LIKELY TO BE WET. MODELS HINT THAT THE RAIN
COULD MOVE INTO OUR WESTERN ZONES LATE MONDAY NIGHT INTO EARLY
TUESDAY MORNING...BUT THE BULK OF THE RAIN APPEARS TO HOLD OFF TIL
AFTER 12Z TUESDAY. RAIN CONTINUES THROUGH TUESDAY INTO THE FIRST
PART OF THE DAY ON WEDNESDAY BUT THEN WILL TAPER OFF AS EITHER THE
FRONT MOVES THROUGH OR THE LOW PRESSURE EJECTS TOWARDS THE MARITIMES.
THE REMAINDER OF THE WEEK LOOKS TO BE DRY WITH A POSSIBILITY OF A
FEW DIURNAL SHOWERS HERE AND THERE EACH DAY. TEMPERATURES ARE
EXPECTED TO BE BELOW TO NEAR NORMAL UNTIL THE WEEKEND WHEN DEPENDING
ON THE MODEL COULD SEE A RETURN TO AUGUST HEAT AND HUMIDITY.
&&
.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
THROUGH TODAY...HIGH CONFIDENCE.
VFR EXPECTED INLAND OF THE CAPE AND ISLANDS. CAPE/ISLAND TERMINALS
WILL SEE SOME MVFR CIGS LATER THIS MORNING AND CONTINUING INTO THE
EARLY AFTERNOON BEFORE DISSIPATING. A SPRINKLE MIGHT ACCOMPANY
THESE LOWER CLOUDS.
OTHERWISE DRY INLAND...BUT A SPOT SHOWER IS POSSIBLE IN THE HIGHER
TERRAIN DURING THE AFTERNOON HOURS.
TONIGHT INTO MON...HIGH CONFIDENCE.
MAINLY VFR. DIURNAL CU EXPECTED AGAIN MON. ALTHOUGH WINDS MAY LEAN
SLIGHTLY E OF N...SEA BREEZES ARE LIKELY DURING THE DAY MON.
KBOS TERMINAL...HIGH CONFIDENCE IN TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TAF.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
TUESDAY...MODERATE CONFIDENCE. MVFR/IFR CONDITIONS LIKELY IN
WIDESPREAD RAIN/FOG.
WEDNESDAY...MODERATE CONFIDENCE. LINGERING MVFR/IFR CONDITIONS IN
DEPARTING RAIN. IMPROVING CONDITIONS THROUGH THE DAY.
THURSDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF
BRIEF MVFR CONDITIONS IN DIURNAL -SHRA.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE THROUGH SUN NIGHT.
DROPPED SCA ON OUTER S COASTAL WATERS WHERE SEAS HAVE SUBSIDED.
LIGHT N/NE WINDS GIVE WAY TO INCREASING NE WINDS SUN AND
ESPECIALLY SUN NIGHT...AS LOW PRESSURE PASSES WELL SE OF NEW
ENGLAND. SEAS SHOULD BEGIN TO BUILD LATER IN DAY AND COULD REACH 5
FT BY SUN NIGHT E AND S OF NANTUCKET...WHICH MAY REQUIRE SCA IN
LATER FORECASTS. DRY WEATHER EXPECTED THROUGH PERIOD.
OUTLOOK /MONDAY THROUGH THURSDAY/...
MONDAY...HIGH CONFIDENCE. WINDS AND SEAS DIMINISH AS HIGH PRESSURE
BUILDS OVER THE WATERS.
TUESDAY...MODERATE CONFIDENCE. WINDS AND SEAS INCREASE AS EITHER A
COLD FRONT OR A LOW PRESSURE SYSTEM MOVE OVER THE WATERS. SMALL
CRAFT ADVISORIES WILL LIKELY BE NEEDED FOR SEAS IF NOT WINDS AS
WELL. VISIBILITIES MAY BE LIMITED AT TIMES IN RAIN.
WEDNESDAY...MODERATE CONFIDENCE. WINDS AND SEAS DIMINISH AS LOW
PRESSURE PULLS AWAY FROM SOUTHERN NEW ENGLAND.
THURSDAY...MODERATE CONFIDENCE. QUIET BOATING WEATHER EXPECTED.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RLG/JWD
NEAR TERM...DOODY/JWD
SHORT TERM...JWD
LONG TERM...RLG
AVIATION...DOODY/RLG
MARINE...RLG/JWD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
508 PM CDT SUN AUG 9 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* VARIABLE WIND DIRECTIONS WITH SPEEDS LESS THAN 10 KTS TRENDING
SOUTHEAST- EAST THROUGH EARLY EVENING.
* PATCHY LIGHT RAIN NEXT 1-2 HOURS BUT GENERALLY VFR CONDITIONS.
* LOWERING CEILINGS THROUGH TONIGHT...BECOMING WIDESPREAD MVFR
WITH PERIODS OF IFR. VLIFR ALSO POSSIBLE.
* ISOLATED THUNDER CHANCE LATE MONDAY AFTERNOON.
MM/RATZER
//DISCUSSION...UPDATED 18Z...
RADAR AND OBSERVATION TRENDS INDICATE IMPROVED VSBY AND CEILINGS
FOR THE REMAINDER OF THE AFTERNOON AS A WEAKENING THUNDERSTORM
COMPLEX PASSES/DIES NEAR IND. SOME SITES IN WI CONTINUE TO
INDICATE MVFR CIGS WHICH MAY BRIEFLY SNEAK INTO THE TAF SITES.
AS LOW PRESSURE CONTINUES TO PASS SOUTH AND EAST OF THE
AREA...WINDS WILL REMAIN EAST...TURNING MORE NORTHERLY MONDAY.
REMNANT LOW LEVEL MOISTURE AND A TEMPERATURE INVERSION WILL KEEP
FOG LIKELY FOR TONIGHT. MODEL CONSENSUS INDICATES IFR IS LIKELY
WITH VLIFR ALSO POSSIBLE. IMPROVEMENTS WILL START AFTER SUNRISE
MONDAY...BUT VFR CONDITIONS ARE NOT EXPECTED UNTIL LATE MORNING.
THUNDER CHANCES REMAIN QUITE LOW FOR MONDAY...DEPENDING ON THE
DEGREE OF HEATING TOMORROW AND THE DEVELOPMENT OF A FORCING
MECHANISM. STILL NOT OUT OF THE QUESTION THOUGH.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH ON WINDS.
* HIGH ON MVFR OVERNIGHT...MEDIUM ON IFR...LOW ON VLIFR.
* LOW ON THUNDER CHANCES MONDAY.
MM/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...CHANCE OF THUNDERSTORMS.
SATURDAY...VFR.
RODRIGUEZ
&&
.MARINE...
251 PM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY MONDAY EVENING. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE
LATE TONIGHT INTO MONDAY MORNING SHIFTING WINDS NORTHERLY. ANOTHER
WEAK LOW WILL MOVE SOUTH OF THE LAKE MONDAY AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE GRADIENT WILL
TIGHTEN BETWEEN THESE TWO FEATURES WITH NORTHERLY WINDS INCREASING
TO 15-25 KTS BY TUESDAY MORNING. AS THE HIGH MOVES EAST...THESE
NORTHERLY WINDS WILL SLOWLY DIMINISH TUESDAY NIGHT INTO WEDNESDAY.
WINDS WILL SHIFT TO THE SOUTHWEST WEDNESDAY NIGHT AS THE HIGH
SETTLES SOUTHEAST OF THE LAKE AND DEPENDING ON HOW STRONG THE
GRADIENT BECOMES...SPEEDS MAY INCREASE INTO THE 15-25KT RANGE
THURSDAY INTO THURSDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
253 PM CDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 253 PM CDT SUN AUG 9 2015
BASED ON SURFACE DATA...APPEARS THERE IS A BOUNDARY STRETCHING FROM
NORTHERN MO/SOUTHERN IA INTO NORTHERN PART OF CENTRAL IL.
HOWEVER...THE EFFECTIVE BOUNDARY SHOULD BE MUCH FURTHER SOUTH AS A
RESULT OF THE MCS THAT MOVED ACROSS THE AREA EARLIER THIS MORNING
PUSHING IT SOUTH OF THE CWA. HRRR DOES NOT SHOW ANY PCPN IN THE CWA
TONIGHT...BUT DOES HAVE THE SMALL AREA OF PCPN IN NORTHERN MO MOVING
EAST-SOUTHEAST INTO SOUTHERN IL THIS EVENING. BUT WITH A WEAK
CONVERGENT BOUNDARY IN THE AREA AM INCLINED TO KEEP A CHANCE FOR
POPS IN THE FORECAST FOR TONIGHT. TREND SHOULD BE...AND MODELS DO
SUPPORT THAT THIS WEAK BOUNDARY SHOULD MOVE SOUTH DURING THE
OVERNIGHT PERIOD. SO CHANCE POPS SOUTHEAST OF THE ILLINOIS RIVER
TONIGHT. ENDING OF PCPN CHANCES WILL START ALONG THE RIVER AND THEN
PROGRESS SOUTHEAST THROUGH THE PERIOD. OTHER ISSUE OVERNIGHT WILL BE
FOG DEVELOPMENT. WITH LOTS OF BREAKS IN THE CLOUDS THIS EVENING AND
OVERNIGHT...COMBINED WITH THE ABUNDANCE OF LOW LEVEL MOISTURE FROM
THE RAIN THIS MORNING...AND LIGHT WINDS...BELIEVE FOG WILL DEVELOP
THIS EVENING AND CONTINUE INTO THE OVERNIGHT HOURS. SO HAVE INCLUDED
AREAS OF FOG IN THE FORECAST THE NORTHERN AND CENTRAL PARTS OF THE
AREA. ONLY PLACE WITHOUT ANY FOG WILL BE AREAS SOUTHEAST OF I-70.
OVERNIGHT LOWS AROUND 70S LOOKS REASONABLE WITH COOLEST TEMPS UP
NORTH WHERE MORE BREAKS IN CLOUDS SHOULD BE.
&&
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 253 PM CDT SUN AUG 9 2015
A FRONTAL BOUNDARY CURRENTLY FROM NORTHERN WISCONSIN TO NORTHERN
NEBRASKA WILL PUSH INTO SOUTHEAST ILLINOIS BY MID MORNING
MONDAY...AIDED BY SEVERAL AREAS OF THUNDERSTORM DEVELOPMENT AHEAD OF
THE FRONT THIS EVENING INTO TONIGHT. THE EFFECTIVE FRONT WILL LIKELY
BE LINGERING IN SOUTHEAST PORTIONS OF THE CENTRAL IL FORECAST AREA
THROUGH THE MORNING AND HAVE CONTINUED PRECIPITATION CHANCES IN THAT
AREA THROUGH NOON. MOST OF THE THUNDERSTORM ACTIVITY WILL TEND TO
MOVE EASTWARD THROUGH THE DAY...HOWEVER AN UPPER LEVEL SHORTWAVE
WILL APPROACH FROM THE NORTHWEST BY AFTERNOON...AND LIFT ASSOCIATED
WITH THIS FEATURE WILL CAUSE CHANCES FOR SHOWERS AND THUNDERSTORMS
TO RE-DEVELOP FOR AFTERNOON AND EARLY EVENING...MAINLY FROM THE
ILLINOIS RIVER NORTHWESTWARD. HIGHS EXPECTED TO REACH FROM AROUND 81
IN GALESBURG TO THE MID 80S SPRINGFIELD TO PARIS SOUTHWARD WITH
WINDS BECOMING NORTHWEST UP TO 10 MPH.
AFTER THIS FEATURE PASSES THROUGH...DRY CONDITIONS ARE EXPECTED
THROUGH MUCH OF THE WEEK AS A PRONOUNCED UPPER LEVEL RIDGE BUILDS
OVER THE CENTRAL U.S. AND TROUGHING OVER THE NORTHEASTERN U.S. A
COOL NORTHWEST FLOW PATTERN BETWEEN THE RIDGE AND TROUGH WILL BRING
HIGH TEMPERATURES PRIMARILY IN THE LOW 80S AND LOWS IN THE LOW 60S
THROUGH THURSDAY. A COLD FRONT EMBEDDED IN THIS FLOW PATTERN WILL
DROP INTO THE GREAT LAKES/MIDWEST AREA FRIDAY. MODELS CONTINUE SOME
RUN TO RUN INCONSISTENCIES FOR THIS FEATURE...BUT BULK OF GUIDANCE
CONTINUES TO SUGGEST PRECIPITATION ASSOCIATED WITH THIS FEATURE MAY
STRUGGLE TO REACH AS FAR SOUTHWEST AS CENTRAL ILLINOIS.
THEREFORE...HAVE INCORPORATED SLIGHT CHANCES FOR THUNDERSTORMS
MAINLY I-72 NORTHWARD. DRY CONDITIONS SHOULD THEN RETURN THROUGH THE
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1232 PM CDT SUN AUG 9 2015
MCS HAS DECAYED AND MOVED EAST OF THE TAF SITES LATE THIS MORNING.
THIS HAS PUSHED THE EFFECTIVE FRONT SOUTH OF THE TAFS AND CURRENT
THINKING...WHICH IS SUPPORTED BY THE CURRENT HRRR MODEL
RUN...SHOWS ALL PCPN SHOULD BE SOUTH OF THE TAF SITES THIS
AFTERNOON AND TONIGHT. ONLY CONCERN IS WITH WINDS BECOMING
LIGHTER AND SKIES BECOMING MOSTLY CLEAR...WITH ALL THE MOISTURE
HAD THIS MORNING...BELIEVE FOG WILL BE AN ISSUE THIS EVENING AND
INTO THE OVERNIGHT HOURS. SO HAVE INCLUDED MVFR CONDITIONS THIS
EVENING AND THEN GOING WITH IFR CONDITIONS DURING THE OVERNIGHT.
WINDS WILL BE SOUTHERLY REMAINDER OF THE AFTERNOON AND THEN BECOME
LIGHT AND VARIABLE THIS EVENING AND OVERNIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AUTEN
LONG TERM...ONTON
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
251 PM CDT SUN AUG 9 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS UNDER 8KT TODAY.
* LOWERING CEILINGS THROUGH TONIGHT...BECOMING WIDESPREAD MVFR
WITH PERIODS OF IFR. VLIFR ALSO POSSIBLE.
* ISOLATED THUNDER CHANCE LATE MONDAY AFTERNOON.
MM
//DISCUSSION...UPDATED 18Z...
RADAR AND OBSERVATION TRENDS INDICATE IMPROVED VSBY AND CEILINGS
FOR THE REMAINDER OF THE AFTERNOON AS A WEAKENING THUNDERSTORM
COMPLEX PASSES/DIES NEAR IND. SOME SITES IN WI CONTINUE TO
INDICATE MVFR CIGS WHICH MAY BRIEFLY SNEAK INTO THE TAF SITES.
AS LOW PRESSURE CONTINUES TO PASS SOUTH AND EAST OF THE
AREA...WINDS WILL REMAIN EAST...TURNING MORE NORTHERLY MONDAY.
REMNANT LOW LEVEL MOISTURE AND A TEMPERATURE INVERSION WILL KEEP
FOG LIKELY FOR TONIGHT. MODEL CONSENSUS INDICATES IFR IS LIKELY
WITH VLIFR ALSO POSSIBLE. IMPROVEMENTS WILL START AFTER SUNRISE
MONDAY...BUT VFR CONDITIONS ARE NOT EXPECTED UNTIL LATE MORNING.
THUNDER CHANCES REMAIN QUITE LOW FOR MONDAY...DEPENDING ON THE
DEGREE OF HEATING TOMORROW AND THE DEVELOPMENT OF A FORCING
MECHANISM. STILL NOT OUT OF THE QUESTION THOUGH.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH ON WINDS.
* HIGH ON MVFR OVERNIGHT...MEDIUM ON IFR...LOW ON VLIFR.
* LOW ON THUNDER CHANCES MONDAY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...CHANCE OF THUNDERSTORMS.
SATURDAY...VFR.
RODRIGUEZ
&&
.MARINE...
251 PM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY MONDAY EVENING. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE
LATE TONIGHT INTO MONDAY MORNING SHIFTING WINDS NORTHERLY. ANOTHER
WEAK LOW WILL MOVE SOUTH OF THE LAKE MONDAY AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE GRADIENT WILL
TIGHTEN BETWEEN THESE TWO FEATURES WITH NORTHERLY WINDS INCREASING
TO 15-25 KTS BY TUESDAY MORNING. AS THE HIGH MOVES EAST...THESE
NORTHERLY WINDS WILL SLOWLY DIMINISH TUESDAY NIGHT INTO WEDNESDAY.
WINDS WILL SHIFT TO THE SOUTHWEST WEDNESDAY NIGHT AS THE HIGH
SETTLES SOUTHEAST OF THE LAKE AND DEPENDING ON HOW STRONG THE
GRADIENT BECOMES...SPEEDS MAY INCREASE INTO THE 15-25KT RANGE
THURSDAY INTO THURSDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
221 PM CDT SUN AUG 9 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
ONE LAST HOORAH AS THE UPPER LOW IN THE CANADIAN PRAIRIES LIFTS
TOWARD HUDSON BAY...OPENING THE DOOR FOR ONE LAST SHORTWAVE IN
NORTHWEST FLOW ALOFT TO MOVE THROUGH WISCONSIN COUPLED WITH
ADDITIONAL FAST MOVING WAVES COMING FROM THE PACIFIC. SLIGHTLY
BETTER LAPSE RATES ALOFT COUPLED WITH A SOUTHWARD MOVING COLD FRONT
WOULD SUGGEST THE POTENTIAL FOR SOME SCATTERED SHOWERS AND
THUNDERSTORMS MONDAY AFTERNOON/EARLY EVENING. SCATTERED MENTION DUE
TO THE TIMING/MOISTURE ISSUES AND THE FACT THE BETTER FORCING SWINGS
BY TO THE NORTH.
THE STRONG UPPER DISTURBANCE SOUTH OF HUDSON BAY WILL MOVE SOUTHEAST
ON MONDAY NIGHT INTO TUESDAY AND HIGH PRESSURE BUILDS IN FOR SEVERAL
DAYS. A HIGHLY AMPLIFIED PATTERN WILL SLOW THE PROGRESSION OF
SHORTWAVE ACTIVITY. WE WILL LARGELY BE UNDER THE INFLUENCE OF A
COMBINATION OF THE WESTERN U.S. RIDGE SUPPLYING THE DRY WEATHER AND
THE COOLING INFLUENCE OF NORTHWEST FLOW ON THE BACK SIDE OF THE
EASTERN U.S TROUGH. HIGHS WILL BE SLIGHTLY BELOW NORMAL WITH
COMFORTABLE HUMIDITY AND DECENT SUNSHINE. MOISTURE RETURN IS LACKING
UNTIL LATER IN THE WEEK WHEN A FRONTAL BOUNDARY DROPS THROUGH
THURSDAY NIGHT INTO FRIDAY. THIS WILL BE OUR NEXT CHANCE FOR SHOWERS
AND THUNDERSTORMS.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* EAST WINDS UNDER 8KT TODAY.
* LOWERING CEILINGS THROUGH TONIGHT...BECOMING WIDESPREAD MVFR
WITH PERIODS OF IFR. VLIFR ALSO POSSIBLE.
* ISOLATED THUNDER CHANCE LATE MONDAY AFTERNOON.
MM
//DISCUSSION...UPDATED 18Z...
RADAR AND OBSERVATION TRENDS INDICATE IMPROVED VSBY AND CEILINGS
FOR THE REMAINDER OF THE AFTERNOON AS A WEAKENING THUNDERSTORM
COMPLEX PASSES/DIES NEAR IND. SOME SITES IN WI CONTINUE TO
INDICATE MVFR CIGS WHICH MAY BRIEFLY SNEAK INTO THE TAF SITES.
AS LOW PRESSURE CONTINUES TO PASS SOUTH AND EAST OF THE
AREA...WINDS WILL REMAIN EAST...TURNING MORE NORTHERLY MONDAY.
REMNANT LOW LEVEL MOISTURE AND A TEMPERATURE INVERSION WILL KEEP
FOG LIKELY FOR TONIGHT. MODEL CONSENSUS INDICATES IFR IS LIKELY
WITH VLIFR ALSO POSSIBLE. IMPROVEMENTS WILL START AFTER SUNRISE
MONDAY...BUT VFR CONDITIONS ARE NOT EXPECTED UNTIL LATE MORNING.
THUNDER CHANCES REMAIN QUITE LOW FOR MONDAY...DEPENDING ON THE
DEGREE OF HEATING TOMORROW AND THE DEVELOPMENT OF A FORCING
MECHANISM. STILL NOT OUT OF THE QUESTION THOUGH.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH ON WINDS.
* HIGH ON MVFR OVERNIGHT...MEDIUM ON IFR...LOW ON VLIFR.
* LOW ON THUNDER CHANCES MONDAY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...CHANCE OF THUNDERSTORMS.
SATURDAY...VFR.
RODRIGUEZ
&&
.MARINE...
230 AM CDT
HIGHLY VARIABLE WIND FIELD ACROSS THE LAKE THIS MORNING AS A
WEAKER SURFACE PATTERN IN PLACE...WITH HIGH PRESSURE SITUATED TO
THE EAST AND NORTHEAST. THESE VARIABLE WINDS WILL LIKELY PERSIST
ACROSS THE NORTHERN HALF OF THE LAKE TODAY WHILE THE SOUTHERN END
BECOMES MORE SOUTHERLY THIS MORNING...AS LOW PRESSURE SLOWLY MOVES
EAST TOWARDS THE REGION. AS THIS THIS LOW CONTINUES EAST NORTHEAST
TO THE SOUTHERN END OF THE LAKE AND A SEPARATE LOW OVER ONTARIO
MOVES EAST TO HUDSON BAY TONIGHT...WINDS WILL LIKELY CONTINUE TO
BE VARIABLE ACROSS THE LAKE. HOWEVER...IT DOES APPEAR THAT SPEEDS
WILL STAY ON THE LIGHTER SIDE THROUGH THIS PERIOD. THIS LOW WILL
THEN MOVE TO THE EASTERN LAKES MONDAY INTO MONDAY NIGHT AS HIGH
PRESSURE TO THE NORTHWEST BEGINS SPREADING SOUTHEAST...WITH
NORTHERLY WINDS SETTING UP ACROSS THE ENTIRE LAKE. AS THE SURFACE
GRADIENT TIGHTENS UP OVER THE LAKE LATE MONDAY AND MONDAY
NIGHT...NORTHERLY SPEEDS WILL BEGIN TO INCREASE. THIS INCREASING
TREND WITH THE NORTHERLY WINDS CONTINUES TUESDAY WITH 15 TO 25 KT
WINDS BECOMING LIKELY DURING THIS TIME.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT SUN AUG 9 2015
.UPDATE...
959 AM CDT
THE CONVECTIVE COMPLEX OVERHEAD IS QUICKLY WARMING ALOFT THIS
MORNING WITH THE SYSTEM CONTINUING TO REFOCUS OVER CENTRAL IL.
RAIN HAS STRUGGLED TO SPREAD NORTH OF A ROCHELLE TO JOLIET TO DE
MOTTE INDIANA LINE THIS MORNING DESPITE A SURGING GRAVITY WAVE
ESQ BOUNDARY SHIFTING NORTHEAST EARLIER THIS MORNING. THE
BOUNDARY HAS WEAKENED CONSIDERABLY AND AREAS ALONG THE
AFOREMENTIONED LINE ARE JUST NOW POSSIBLY SEEING SOME SPRINKLES.
IN GENERAL THE RAIN WILL GRADUALLY WEAKEN AS IT SHIFTS EAST WITH
THE MAJORITY OF RAIN FALLING SOUTH OF A MENDOTA TO JOLIET TO DE
MOTTE INDIANA LINE. FAR NORTHEAST IL INCLUDING THE CHICAGO METRO
MAY SEE SOME SPRINKLES TO A LIGHT RAIN SHOWER CLOSER TO NOON...BUT
NOTHING OVERLY SIGNIFICANT. ISOLATED EMBEDDED THUNDERSTORMS ARE
ALSO POSSIBLE SOUTH OF THE MENDOTA...JOLIET...DE MOTTE LINE
THROUGH THE MORNING BUT NO SEVERE WEATHER IS EXPECTED.
GUIDANCE IS REALLY STRUGGLING WITH THE CONVECTIVE EVOLUTION GOING
INTO THIS AFTERNOON WITH THE RAP AND HRRR LOOKING THE MOST
REASONABLE THUS FAR. MADE MINOR TWEAKS TO PRECIP CHANCES THROUGH
THIS AFTN WITH THE FOCUS FOR EITHER FESTERING RAIN AND STORMS OR
SOME REDEVELOPMENT ALONG AND SOUTH OF I-80. KEPT A CHANCE OF
SHOWERS AND STORMS ACROSS THE CWA THIS AFTERNOON AS CONFIDENCE IS
LOW AS TO HOW FAR NORTH ACTIVITY WILL CONTINUE TO FESTER. WITH THE
MCV OVER CENTRAL IL...HAVE MUCH HIGHER CONFIDENCE IN AREAS SOUTH
OF I-80 SEEING THE MAJORITY OF ACTIVITY. DEBATED GOING DRY NORTH
OF I-88 THIS AFTN...BUT CANNOT RULE OUT A FEW SHOWERS AND PERHAPS
A STORM.
AS FAR AS STRONG TO SEVERE STORMS...CANNOT RULE OUT ONE OR TWO
STRONG STORMS...BUT THINKING WE WILL STRUGGLE TO RECOVER THIS AFTN
GIVEN THE THICK CLOUD COVER AND LINGERING RAIN. AGREE WITH THE
MARGINAL RISK FROM SPC. THINKING THE AREA OF CONCERN WOULD BE
SOUTH OF A STREATOR TO DE MOTTE LINE WITH THE BEST ACTIVITY WELL
SOUTH OF THE CWA OVER CENTRAL IL MUCH CLOSER TO THE MCV.
JEE
&&
.SHORT TERM...
358 AM CDT
THROUGH SUNDAY NIGHT...
TWO COMPLEXES OF SHOWERS AND THUNDERSTORMS ARE ONGOING EARLY THIS
MORNING THOUGH HAVE GENERALLY BEEN MERGING INTO ONE TO SOME
DEGREE...THOUGH STILL LOOK TO BE DISTINCT BASED ON THE LIGHTNING
AXES IN CENTRAL IOWA EXTENDING INTO WESTERN ILLINOIS..AND A
SEPARATE AREA IN SOUTHERN IOWA INTO NORTHERN MISSOURI.
AT THE MOMENT...THE NORTHERN EXTENT OF THE NORTHERN BATCH ENTERING
NW ILLINOIS IS IN A LESS HOSPITABLE ENVIRONMENT FOR CONTINUED FORWARD
PROPAGATION AND GROWTH AND BEING DRIVEN MORE SO FROM AN UPPER
LEVEL SHORTWAVE RIDING THE NORTHERN FRINGE OF THE RIDGE AXIS. THE
DEPTH OF THESE SHOWERS IS NOT IMPRESSIVE...AND EROSION ON THIS
ACTIVITY CONTINUES WITH JUST SOME LIGHT RAIN/SPRINKLES...WITH THE BEST
CHANCE FOR EROSION TO CONTINUE WILL BE IN NORTHERN ILLINOIS WITH
THE DRIEST AIRMASS AND MOST REMOVED FROM THE MAIN LOWER LEVEL
FORCING/BAROCLINIC ZONE. THE LLJ IS FOCUSED MORE-SO INTO THE
SOUTHERN MOST STORMS WHICH HAVE THE UPPER ENERGY SUPPORT COMBINED
WITH A BETTER THERMODYNAMIC ENVIRONMENT. LASALLE/LIVINGSTON/LEE
COUNTIES OR ON THE EASTERN EXTENT OF THE BETTER LLJ FORCING WHERE
MORE ORGANIZED AND SUSTAINED DEVELOPMENT WILL CONTINUE IN THE
COMING HOURS. MORE ROBUST DEVELOPMENT IS OCCURRING ON THE BACK
SIDE OF THIS COMPLEX WHERE A PORTION OF THE STRONGER LLJ WHICH
FEEDING THE SOUTHERN SYSTEM IS ABLE TO ADVECT NORTH INTO THE
NORTHERN STREAM ACTIVITY.
WITH THIS COMPLEX SETUP AT THE MOMENT...CONFIDENCE ON THE EVOLUTION
IS NOT AS HIGH AS I WOULD LIKE IT TO BE WITH MODELS STRUGGLING WITH
INITIALIZATIONS. THERE IS LITTLE TO SUGGEST THAT THESE SHOWERS AND
STORMS WON`T CONTINUE EASTWARD ONCE THE SHORTWAVE DRIVING IT
MOVES RIGHT ON THROUGH NE ILLINOIS...BUT DO PREFER THE HRRR
SOLUTION WHICH JUST BRINGS SOME LIGHTER RAIN NORTH (AND POSSIBLY
DRY IN FAR NORTH/NE ILLINOIS) AND FOCUSES ACTIVITY SOUTH THIS
MORNING. THE LLJ WHICH IS STILL STRONGEST IA BASED ON AREA VWPS
WILL BECOME ORIENTED SW-NE WITH THE MOISTURE CONVERGENCE AXIS
POINTED RIGHT AT US. THE INSTABILITY AXIS LOOKS TO BE POSITIONED
ACROSS THE CENTER OF THE CWA WHICH WILL LIKELY KEEP THE NORTHERN
AREAS JUST RAIN...WHEREAS POINTS SOUTH WILL AT LEAST SEE EMBEDDED
THUNDER DESPITE MARGINAL MID LEVEL LAPSE RATES. PRECIPITABLE WATER
VALUES ARE QUITE AN UPTICK THIS MORNING...SO THE I-80 SOUTHWARD
CORRIDOR MAY SEE SOME 1" PER HOUR RATES IN AN EFFICIENT
ENVIRONMENT.
SOME UNCERTAINTIES ON REMAINING FORCING IN THE AFTERNOON...AND
POTENTIAL FOR MORNING ACTIVITY TO KEEP ANY OUTFLOW FOCUSED SOUTH
OF THE AREA. THE LOCATION OF THE SURFACE FRONT MAY BECOME A BIT
MORE UNCERTAIN AFTER THESE STORMS LAY OUT ANY OUTFLOW. THE AIR
MASS WILL BE MOIST...THERE WILL BE SOME SHEAR AROUND...AND A LOW
LEVEL BOUNDARY...WHICH PRESENTS SOME CONCERNS WITH ANY ADDITIONAL
SUBTLE SHORTWAVES THAT MAY PASS THROUGH IN PROGRESSIVE WESTERLY
FLOW. HI-RES GUIDANCE IS RE-GENERATING STORMS IN IOWA THIS
AFTERNOON...AND DEPENDING ON WHERE THE SURFACE BOUNDARY ENDS UP
COULD POSE A MARGINAL SVR THREAT AS OUTLINED IN THE DAY 1 OUTLOOK
AND WILL NEED TO BE IRONED OUT BY THE DAY SHIFT.
AFTER WHAT COULD BE AN AFTERNOON LULL..THE SURFACE LOW TO OUR SOUTH
LIFTS NORTHEASTWARD SUNDAY NIGHT INTO EARLY MONDAY. ANOTHER
SHORTWAVE APPROACHES WITH THE INVERTED TROUGH AXIS POINTED RIGHT
OVER NORTHEAST ILLINOIS TONIGHT FOR POTENTIALLY A REINVIGORATION OF
SHOWERS...BUT STILL SOME UNCERTAINTY ON COVERAGE AT THIS POINT.
KMD
&&
.LONG TERM...
ONE LAST HOORAH AS THE UPPER LOW IN THE CANADIAN PRAIRIES LIFTS
TOWARD HUDSON BAY...OPENING THE DOOR FOR ONE LAST SHORTWAVE IN
NORTHWEST FLOW ALOFT TO MOVE THROUGH WISCONSIN COUPLED WITH
ADDITIONAL FAST MOVING WAVES COMING FROM THE PACIFIC. SLIGHTLY
BETTER LAPSE RATES ALOFT COUPLED WITH A SOUTHWARD MOVING COLD FRONT
WOULD SUGGEST THE POTENTIAL FOR SOME SCATTERED SHOWERS AND
THUNDERSTORMS MONDAY AFTERNOON/EARLY EVENING. SCATTERED MENTION DUE
TO THE TIMING/MOISTURE ISSUES AND THE FACT THE BETTER FORCING SWINGS
BY TO THE NORTH.
THE STRONG UPPER DISTURBANCE SOUTH OF HUDSON BAY WILL MOVE SOUTHEAST
ON MONDAY NIGHT INTO TUESDAY AND HIGH PRESSURE BUILDS IN FOR SEVERAL
DAYS. A HIGHLY AMPLIFIED PATTERN WILL SLOW THE PROGRESSION OF
SHORTWAVE ACTIVITY. WE WILL LARGELY BE UNDER THE INFLUENCE OF A
COMBINATION OF THE WESTERN U.S. RIDGE SUPPLYING THE DRY WEATHER AND
THE COOLING INFLUENCE OF NORTHWEST FLOW ON THE BACK SIDE OF THE
EASTERN U.S TROUGH. HIGHS WILL BE SLIGHTLY BELOW NORMAL WITH
COMFORTABLE HUMIDITY AND DECENT SUNSHINE. MOISTURE RETURN IS LACKING
UNTIL LATER IN THE WEEK WHEN A FRONTAL BOUNDARY DROPS THROUGH
THURSDAY NIGHT INTO FRIDAY. THIS WILL BE OUR NEXT CHANCE FOR SHOWERS
AND THUNDERSTORMS.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* EAST WINDS UNDER 8KT TODAY.
* LOWERING CEILINGS THROUGH TONIGHT...BECOMING WIDESPREAD MVFR
WITH PERIODS OF IFR. VLIFR ALSO POSSIBLE.
* ISOLATED THUNDER CHANCE LATE MONDAY AFTERNOON.
MM
//DISCUSSION...UPDATED 18Z...
RADAR AND OBSERVATION TRENDS INDICATE IMPROVED VSBY AND CEILINGS
FOR THE REMAINDER OF THE AFTERNOON AS A WEAKENING THUNDERSTORM
COMPLEX PASSES/DIES NEAR IND. SOME SITES IN WI CONTINUE TO
INDICATE MVFR CIGS WHICH MAY BRIEFLY SNEAK INTO THE TAF SITES.
AS LOW PRESSURE CONTINUES TO PASS SOUTH AND EAST OF THE
AREA...WINDS WILL REMAIN EAST...TURNING MORE NORTHERLY MONDAY.
REMNANT LOW LEVEL MOISTURE AND A TEMPERATURE INVERSION WILL KEEP
FOG LIKELY FOR TONIGHT. MODEL CONSENSUS INDICATES IFR IS LIKELY
WITH VLIFR ALSO POSSIBLE. IMPROVEMENTS WILL START AFTER SUNRISE
MONDAY...BUT VFR CONDITIONS ARE NOT EXPECTED UNTIL LATE MORNING.
THUNDER CHANCES REMAIN QUITE LOW FOR MONDAY...DEPENDING ON THE
DEGREE OF HEATING TOMORROW AND THE DEVELOPMENT OF A FORCING
MECHANISM. STILL NOT OUT OF THE QUESTION THOUGH.
MM
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH ON WINDS.
* HIGH ON MVFR OVERNIGHT...MEDIUM ON IFR...LOW ON VLIFR.
* LOW ON THUNDER CHANCES MONDAY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...CHANCE OF THUNDERSTORMS.
SATURDAY...VFR.
RODRIGUEZ
&&
.MARINE...
230 AM CDT
HIGHLY VARIABLE WIND FIELD ACROSS THE LAKE THIS MORNING AS A
WEAKER SURFACE PATTERN IN PLACE...WITH HIGH PRESSURE SITUATED TO
THE EAST AND NORTHEAST. THESE VARIABLE WINDS WILL LIKELY PERSIST
ACROSS THE NORTHERN HALF OF THE LAKE TODAY WHILE THE SOUTHERN END
BECOMES MORE SOUTHERLY THIS MORNING...AS LOW PRESSURE SLOWLY MOVES
EAST TOWARDS THE REGION. AS THIS THIS LOW CONTINUES EAST NORTHEAST
TO THE SOUTHERN END OF THE LAKE AND A SEPARATE LOW OVER ONTARIO
MOVES EAST TO HUDSON BAY TONIGHT...WINDS WILL LIKELY CONTINUE TO
BE VARIABLE ACROSS THE LAKE. HOWEVER...IT DOES APPEAR THAT SPEEDS
WILL STAY ON THE LIGHTER SIDE THROUGH THIS PERIOD. THIS LOW WILL
THEN MOVE TO THE EASTERN LAKES MONDAY INTO MONDAY NIGHT AS HIGH
PRESSURE TO THE NORTHWEST BEGINS SPREADING SOUTHEAST...WITH
NORTHERLY WINDS SETTING UP ACROSS THE ENTIRE LAKE. AS THE SURFACE
GRADIENT TIGHTENS UP OVER THE LAKE LATE MONDAY AND MONDAY
NIGHT...NORTHERLY SPEEDS WILL BEGIN TO INCREASE. THIS INCREASING
TREND WITH THE NORTHERLY WINDS CONTINUES TUESDAY WITH 15 TO 25 KT
WINDS BECOMING LIKELY DURING THIS TIME.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1232 PM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1032 AM CDT SUN AUG 9 2015
MCS CONTINUES TO MOVE EAST AND BASED ON RADAR AND SATELLITE
TRENDS...SHOULD CONTINUE TO DECAY AS WELL. STRONGEST PART OF THE
STORM ALSO CONTINUES TO TRANSLATE SOUTH AND WILL MOVE ACROSS
PORTIONS OF SOUTHEAST ILLINOIS THIS AFTERNOON. ONCE THIS MOVES
THROUGH BY EARLY THIS AFTERNOON...SKIES SHOULD BECOME PARTLY SUNNY
WITH MAYBE SOME SCATTERED SHOWERS. WILL BE MAKING SOME ADJUSTMENTS
TO THE GOING FORECAST TO ACCOUNT FOR THIS TREND IN PCPN AND CLOUD
COVER. THIS DECAYING MCS WILL ALSO ACT TO PUSH THE SURFACE
BOUNDARY LITTLE FURTHER SOUTH FOR REMAINDER OF THE AFTERNOON.
UPDATE WILL BE OUT SHORTLY.
&&
.SHORT TERM...(TODAY)
ISSUED AT 304 AM CDT SUN AUG 9 2015
07Z/2AM SURFACE ANALYSIS SHOWS 1008MB LOW OVER NORTHEAST
KANSAS...WITH WEAK FRONTAL BOUNDARY EXTENDING ACROSS NORTHERN
MISSOURI INTO CENTRAL ILLINOIS. SEVERAL CLUSTERS OF THUNDERSTORMS
HAVE DEVELOPED JUST NORTH OF THE BOUNDARY NEAR THE LOW...AIDED BY A
35-40KT 850MB JET AS EVIDENCED BY REGIONAL VWP NETWORK. STORMS WERE
SLIGHTLY SLOWER TO DEVELOP THAN PREVIOUSLY THOUGHT...SO THEIR
EASTWARD PROGRESSION HAS BEEN DELAYED AS WELL. AS LOW-LEVEL JET
VEERS...STORMS WILL BEGIN TO DEVELOP/PROPAGATE EASTWARD ALONG THE
BOUNDARY AND WILL SPILL INTO WEST-CENTRAL ILLINOIS BETWEEN 09Z AND
12Z. THANKS TO AN INFLOW OF RICH LOW-LEVEL MOISTURE RESULTING IN
PRECIPITABLE WATER VALUES INCREASING TO OVER 2 INCHES...LOCALLY
HEAVY RAINFALL WILL BE LIKELY AS THE MCS ARRIVES. HIGHEST POPS WILL
BE FOCUSED ALONG/WEST OF I-55 WHERE RAINFALL AMOUNTS OF 1 TO 1.50
WILL BE LIKELY. AS MCS UNDERGOES DIURNAL WEAKENING...RAIN TOTALS
WILL STEADILY DECREASE FURTHER EAST...WITH ONLY AROUND 0.25 EXPECTED
NEAR THE INDIANA BORDER. BASED ON POSITION OF FRONTAL
BOUNDARY...THINK THE FAR SOUTHEAST KILX CWA ALONG/SOUTH OF I-70 WILL
SEE LITTLE OR NO RAIN FROM THIS SYSTEM. DUE TO PRECIP AND EXTENSIVE
CLOUD COVER FROM THE MORNING MCS...HIGH TEMPS WILL BE TRICKY TODAY.
HAVE GONE WITH AFTERNOON HIGHS IN THE LOWER 80S ACROSS THE NORTHERN
HALF OF THE CWA...WITH MIDDLE TO UPPER 80S FAR SOUTHEAST.
.LONG TERM...(TONIGHT THROUGH SATURDAY)
ISSUED AT 304 AM CDT SUN AUG 9 2015
ADDITIONAL CONVECTION MAY DEVELOP ALONG THE OUTFLOW BOUNDARY LEFT
BEHIND BY THE MORNING MCS...HOWEVER EXACT POSITION OF THAT BOUNDARY
REMAINS IN QUESTION. MODEL CONSENSUS SEEMS TO BE FOCUSING
ALONG/SOUTH OF I-70 THIS EVENING...SO HAVE CARRIED LIKELY POPS
ACROSS THIS AREA. FURTHER NORTH...HAVE GONE WITH CHANCE POPS ACROSS
THE REMAINDER OF THE CWA THROUGH THE EVENING...FOLLOWED BY MAINLY
DRY CONDITIONS AFTER MIDNIGHT. DESPITE FRONTAL BOUNDARY DROPPING
SOUTH OF THE AREA...HAVE HUNG ON TO SLIGHT CHANCE POPS MONDAY AND
MONDAY EVENING DUE TO A TRAILING 500MB WAVE AND WEAK SURFACE TROUGH.
LAPSE RATES APPEAR TO BECOME STEEP ENOUGH TO SUPPORT AT LEAST
ISOLATED SHOWERS/THUNDER...PRIMARILY DURING PEAK HEATING. ONCE
DAYTIME INSTABILITY IS LOST...CONVECTION WILL QUICKLY DISSIPATE
AFTER SUNSET.
AFTER THAT...PRONOUNCED UPPER RIDGE WILL BUILD OVER THE CENTRAL
CONUS INTO SOUTHERN CANADA FOR THE MIDDLE AND END OF THE WEEK.
DOWNSTREAM TROUGHING ACROSS THE GREAT LAKES/OHIO RIVER VALLEY WILL
ENSURE A COOL/DRY PATTERN FOR CENTRAL ILLINOIS TUESDAY THROUGH
THURSDAY. ONLY POTENTIAL FLY-IN-THE-OINTMENT WILL COME INTO PLAY ON
FRIDAY AS A WEAK COLD FRONT DROPS TOWARD THE REGION. BOTH THE GFS
AND ECMWF BRING THE BOUNDARY INTO NORTHERN ILLINOIS BY FRIDAY
AFTERNOON...THEN WASH IT OUT ACROSS CENTRAL ILLINOIS FRIDAY NIGHT
INTO SATURDAY AS UPPER HEIGHTS RISE ACROSS THE AREA. WILL CARRY
SLIGHT CHANCE POPS ALONG/NORTH OF I-74 DURING THE DAY FRIDAY...BUT
WILL RETURN TO A DRY FORECAST FRIDAY NIGHT INTO SATURDAY ACCORDINGLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1232 PM CDT SUN AUG 9 2015
MCS HAS DECAYED AND MOVED EAST OF THE TAF SITES LATE THIS MORNING.
THIS HAS PUSHED THE EFFECTIVE FRONT SOUTH OF THE TAFS AND CURRENT
THINKING...WHICH IS SUPPORTED BY THE CURRENT HRRR MODEL
RUN...SHOWS ALL PCPN SHOULD BE SOUTH OF THE TAF SITES THIS
AFTERNOON AND TONIGHT. ONLY CONCERN IS WITH WINDS BECOMING
LIGHTER AND SKIES BECOMING MOSTLY CLEAR...WITH ALL THE MOISTURE
HAD THIS MORNING...BELIEVE FOG WILL BE AN ISSUE THIS EVENING AND
INTO THE OVERNIGHT HOURS. SO HAVE INCLUDED MVFR CONDITIONS THIS
EVENING AND THEN GOING WITH IFR CONDITIONS DURING THE OVERNIGHT.
WINDS WILL BE SOUTHERLY REMAINDER OF THE AFTERNOON AND THEN BECOME
LIGHT AND VARIABLE THIS EVENING AND OVERNIGHT.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AUTEN
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...AUTEN
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1101 AM CDT SUN AUG 9 2015
.UPDATE...
959 AM CDT
THE CONVECTIVE COMPLEX OVERHEAD IS QUICKLY WARMING ALOFT THIS
MORNING WITH THE SYSTEM CONTINUING TO REFOCUS OVER CENTRAL IL.
RAIN HAS STRUGGLED TO SPREAD NORTH OF A ROCHELLE TO JOLIET TO DE
MOTTE INDIANA LINE THIS MORNING DESPITE A SURGING GRAVITY WAVE
ESQ BOUNDARY SHIFTING NORTHEAST EARLIER THIS MORNING. THE
BOUNDARY HAS WEAKENED CONSIDERABLY AND AREAS ALONG THE
AFOREMENTIONED LINE ARE JUST NOW POSSIBLY SEEING SOME SPRINKLES.
IN GENERAL THE RAIN WILL GRADUALLY WEAKEN AS IT SHIFTS EAST WITH
THE MAJORITY OF RAIN FALLING SOUTH OF A MENDOTA TO JOLIET TO DE
MOTTE INDIANA LINE. FAR NORTHEAST IL INCLUDING THE CHICAGO METRO
MAY SEE SOME SPRINKLES TO A LIGHT RAIN SHOWER CLOSER TO NOON...BUT
NOTHING OVERLY SIGNIFICANT. ISOLATED EMBEDDED THUNDERSTORMS ARE
ALSO POSSIBLE SOUTH OF THE MENDOTA...JOLIET...DE MOTTE LINE
THROUGH THE MORNING BUT NO SEVERE WEATHER IS EXPECTED.
GUIDANCE IS REALLY STRUGGLING WITH THE CONVECTIVE EVOLUTION GOING
INTO THIS AFTERNOON WITH THE RAP AND HRRR LOOKING THE MOST
REASONABLE THUS FAR. MADE MINOR TWEAKS TO PRECIP CHANCES THROUGH
THIS AFTN WITH THE FOCUS FOR EITHER FESTERING RAIN AND STORMS OR
SOME REDEVELOPMENT ALONG AND SOUTH OF I-80. KEPT A CHANCE OF
SHOWERS AND STORMS ACROSS THE CWA THIS AFTERNOON AS CONFIDENCE IS
LOW AS TO HOW FAR NORTH ACTIVITY WILL CONTINUE TO FESTER. WITH THE
MCV OVER CENTRAL IL...HAVE MUCH HIGHER CONFIDENCE IN AREAS SOUTH
OF I-80 SEEING THE MAJORITY OF ACTIVITY. DEBATED GOING DRY NORTH
OF I-88 THIS AFTN...BUT CANNOT RULE OUT A FEW SHOWERS AND PERHAPS
A STORM.
AS FAR AS STRONG TO SEVERE STORMS...CANNOT RULE OUT ONE OR TWO
STRONG STORMS...BUT THINKING WE WILL STRUGGLE TO RECOVER THIS AFTN
GIVEN THE THICK CLOUD COVER AND LINGERING RAIN. AGREE WITH THE
MARGINAL RISK FROM SPC. THINKING THE AREA OF CONCERN WOULD BE
SOUTH OF A STREATOR TO DE MOTTE LINE WITH THE BEST ACTIVITY WELL
SOUTH OF THE CWA OVER CENTRAL IL MUCH CLOSER TO THE MCV.
JEE
&&
.SHORT TERM...
358 AM CDT
THROUGH SUNDAY NIGHT...
TWO COMPLEXES OF SHOWERS AND THUNDERSTORMS ARE ONGOING EARLY THIS
MORNING THOUGH HAVE GENERALLY BEEN MERGING INTO ONE TO SOME
DEGREE...THOUGH STILL LOOK TO BE DISTINCT BASED ON THE LIGHTNING
AXES IN CENTRAL IOWA EXTENDING INTO WESTERN ILLINOIS..AND A
SEPARATE AREA IN SOUTHERN IOWA INTO NORTHERN MISSOURI.
AT THE MOMENT...THE NORTHERN EXTENT OF THE NORTHERN BATCH ENTERING
NW ILLINOIS IS IN A LESS HOSPITABLE ENVIRONMENT FOR CONTINUED FORWARD
PROPAGATION AND GROWTH AND BEING DRIVEN MORE SO FROM AN UPPER
LEVEL SHORTWAVE RIDING THE NORTHERN FRINGE OF THE RIDGE AXIS. THE
DEPTH OF THESE SHOWERS IS NOT IMPRESSIVE...AND EROSION ON THIS
ACTIVITY CONTINUES WITH JUST SOME LIGHT RAIN/SPRINKLES...WITH THE BEST
CHANCE FOR EROSION TO CONTINUE WILL BE IN NORTHERN ILLINOIS WITH
THE DRIEST AIRMASS AND MOST REMOVED FROM THE MAIN LOWER LEVEL
FORCING/BAROCLINIC ZONE. THE LLJ IS FOCUSED MORE-SO INTO THE
SOUTHERN MOST STORMS WHICH HAVE THE UPPER ENERGY SUPPORT COMBINED
WITH A BETTER THERMODYNAMIC ENVIRONMENT. LASALLE/LIVINGSTON/LEE
COUNTIES OR ON THE EASTERN EXTENT OF THE BETTER LLJ FORCING WHERE
MORE ORGANIZED AND SUSTAINED DEVELOPMENT WILL CONTINUE IN THE
COMING HOURS. MORE ROBUST DEVELOPMENT IS OCCURRING ON THE BACK
SIDE OF THIS COMPLEX WHERE A PORTION OF THE STRONGER LLJ WHICH
FEEDING THE SOUTHERN SYSTEM IS ABLE TO ADVECT NORTH INTO THE
NORTHERN STREAM ACTIVITY.
WITH THIS COMPLEX SETUP AT THE MOMENT...CONFIDENCE ON THE EVOLUTION
IS NOT AS HIGH AS I WOULD LIKE IT TO BE WITH MODELS STRUGGLING WITH
INITIALIZATIONS. THERE IS LITTLE TO SUGGEST THAT THESE SHOWERS AND
STORMS WON`T CONTINUE EASTWARD ONCE THE SHORTWAVE DRIVING IT
MOVES RIGHT ON THROUGH NE ILLINOIS...BUT DO PREFER THE HRRR
SOLUTION WHICH JUST BRINGS SOME LIGHTER RAIN NORTH (AND POSSIBLY
DRY IN FAR NORTH/NE ILLINOIS) AND FOCUSES ACTIVITY SOUTH THIS
MORNING. THE LLJ WHICH IS STILL STRONGEST IA BASED ON AREA VWPS
WILL BECOME ORIENTED SW-NE WITH THE MOISTURE CONVERGENCE AXIS
POINTED RIGHT AT US. THE INSTABILITY AXIS LOOKS TO BE POSITIONED
ACROSS THE CENTER OF THE CWA WHICH WILL LIKELY KEEP THE NORTHERN
AREAS JUST RAIN...WHEREAS POINTS SOUTH WILL AT LEAST SEE EMBEDDED
THUNDER DESPITE MARGINAL MID LEVEL LAPSE RATES. PRECIPITABLE WATER
VALUES ARE QUITE AN UPTICK THIS MORNING...SO THE I-80 SOUTHWARD
CORRIDOR MAY SEE SOME 1" PER HOUR RATES IN AN EFFICIENT
ENVIRONMENT.
SOME UNCERTAINTIES ON REMAINING FORCING IN THE AFTERNOON...AND
POTENTIAL FOR MORNING ACTIVITY TO KEEP ANY OUTFLOW FOCUSED SOUTH
OF THE AREA. THE LOCATION OF THE SURFACE FRONT MAY BECOME A BIT
MORE UNCERTAIN AFTER THESE STORMS LAY OUT ANY OUTFLOW. THE AIR
MASS WILL BE MOIST...THERE WILL BE SOME SHEAR AROUND...AND A LOW
LEVEL BOUNDARY...WHICH PRESENTS SOME CONCERNS WITH ANY ADDITIONAL
SUBTLE SHORTWAVES THAT MAY PASS THROUGH IN PROGRESSIVE WESTERLY
FLOW. HI-RES GUIDANCE IS RE-GENERATING STORMS IN IOWA THIS
AFTERNOON...AND DEPENDING ON WHERE THE SURFACE BOUNDARY ENDS UP
COULD POSE A MARGINAL SVR THREAT AS OUTLINED IN THE DAY 1 OUTLOOK
AND WILL NEED TO BE IRONED OUT BY THE DAY SHIFT.
AFTER WHAT COULD BE AN AFTERNOON LULL..THE SURFACE LOW TO OUR SOUTH
LIFTS NORTHEASTWARD SUNDAY NIGHT INTO EARLY MONDAY. ANOTHER
SHORTWAVE APPROACHES WITH THE INVERTED TROUGH AXIS POINTED RIGHT
OVER NORTHEAST ILLINOIS TONIGHT FOR POTENTIALLY A REINVIGORATION OF
SHOWERS...BUT STILL SOME UNCERTAINTY ON COVERAGE AT THIS POINT.
KMD
&&
.LONG TERM...
ONE LAST HOORAH AS THE UPPER LOW IN THE CANADIAN PRAIRIES LIFTS
TOWARD HUDSON BAY...OPENING THE DOOR FOR ONE LAST SHORTWAVE IN
NORTHWEST FLOW ALOFT TO MOVE THROUGH WISCONSIN COUPLED WITH
ADDITIONAL FAST MOVING WAVES COMING FROM THE PACIFIC. SLIGHTLY
BETTER LAPSE RATES ALOFT COUPLED WITH A SOUTHWARD MOVING COLD FRONT
WOULD SUGGEST THE POTENTIAL FOR SOME SCATTERED SHOWERS AND
THUNDERSTORMS MONDAY AFTERNOON/EARLY EVENING. SCATTERED MENTION DUE
TO THE TIMING/MOISTURE ISSUES AND THE FACT THE BETTER FORCING SWINGS
BY TO THE NORTH.
THE STRONG UPPER DISTURBANCE SOUTH OF HUDSON BAY WILL MOVE SOUTHEAST
ON MONDAY NIGHT INTO TUESDAY AND HIGH PRESSURE BUILDS IN FOR SEVERAL
DAYS. A HIGHLY AMPLIFIED PATTERN WILL SLOW THE PROGRESSION OF
SHORTWAVE ACTIVITY. WE WILL LARGELY BE UNDER THE INFLUENCE OF A
COMBINATION OF THE WESTERN U.S. RIDGE SUPPLYING THE DRY WEATHER AND
THE COOLING INFLUENCE OF NORTHWEST FLOW ON THE BACK SIDE OF THE
EASTERN U.S TROUGH. HIGHS WILL BE SLIGHTLY BELOW NORMAL WITH
COMFORTABLE HUMIDITY AND DECENT SUNSHINE. MOISTURE RETURN IS LACKING
UNTIL LATER IN THE WEEK WHEN A FRONTAL BOUNDARY DROPS THROUGH
THURSDAY NIGHT INTO FRIDAY. THIS WILL BE OUR NEXT CHANCE FOR SHOWERS
AND THUNDERSTORMS.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* MVFR CONDITIONS IN FOG AND LIGHT RAIN SHOWERS...IMPROVING AFTER
20Z.
* WINDS EAST AT 7-9KT THIS AFTERNOON.
* FOG AND LOW CEILINGS TONIGHT...LOW END MVFR CEILINGS WITH IFR
POSSIBLE.
MM
//DISCUSSION...UPDATED 12Z...
LATEST RADAR IMAGERY DEPICTING PRECIP SHIELD STILL SLOWLY MOVING
EAST ACROSS NORTHERN ILLINOIS...WITH ITS EASTERN EXTENT STILL
ERODING AT THIS TIME. MOST GUIDANCE INCLUDING SHORT TERM...NOT
QUITE HANDLING EVOLUTION OF THIS PRECIP TOO WELL THIS
MORNING...BUT STILL THINKING PRECIP WILL REACH THE TERMINALS LATER
TODAY. PERSISTENT FORCING WILL CONTINUE THROUGH MIDDAY AND WHILE
THE COLUMN SATURATES...SHOULD BEGIN TO SEE PRECIP REACHING THE
TERMINALS BY LATE MORNING/MIDDAY. HOWEVER...COVERAGE MAY BE MORE
SCATTERED DURING THIS TIME. CONFIDENCE IS HIGHER THAT ANY THUNDER
TODAY WILL BE WELL SOUTH OF THE TERMINALS...AND HAVE CONTINUED TO
EXCLUDE FROM TAFS. WITH THIS SLOW MOVING SYSTEM ITS POSSIBLE AT
LEAST ISOLATED TO WIDELY SCATTERED SHOWERS MAY LINGER ACROSS THE
TERMINALS THROUGH THIS EVENING...BEFORE DEPARTING TO THE EAST. VFR
CONDITIONS TODAY WILL EVENTUALLY LOWER AND SLOWED THIS TREND THAN
WHAT GUIDANCE IS INDICATING...THINKING THE LOWER CEILINGS WONT
ARRIVE UNTIL LATER THIS EVENING WHEN SURFACE LOW/TROUGH MOVES
OVERHEAD. HAVE LOW END MVFR CEILINGS BUT DO THINK IFR WILL
EVENTUALLY BE POSSIBLE. DONT HAVE A GOOD FEEL WITH TIMING OF THIS
POSSIBLE IFR...AND SO HAVE LEFT OUT AT THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH FOG AND RAIN VSBY RESTRICTIONS.
* HIGH WITH EASTERLY WIND DIRECTION...MEDIUM THAT SPEEDS STAY
BELOW 10KT.
* MEDIUM CONFIDENCE WITH SHOWERS THIS AFTERNOON/EVENING.
* HIGH CONFIDENCE WITH FOG AND LOW CEILINGS OCCURRING
TONIGHT...MEDIUM LOW WITH CIG HEIGHT AND TIMING/DURATION.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...CHANCE OF THUNDERSTORMS.
SATURDAY...VFR.
RODRIGUEZ
&&
.MARINE...
230 AM CDT
HIGHLY VARIABLE WIND FIELD ACROSS THE LAKE THIS MORNING AS A
WEAKER SURFACE PATTERN IN PLACE...WITH HIGH PRESSURE SITUATED TO
THE EAST AND NORTHEAST. THESE VARIABLE WINDS WILL LIKELY PERSIST
ACROSS THE NORTHERN HALF OF THE LAKE TODAY WHILE THE SOUTHERN END
BECOMES MORE SOUTHERLY THIS MORNING...AS LOW PRESSURE SLOWLY MOVES
EAST TOWARDS THE REGION. AS THIS THIS LOW CONTINUES EAST NORTHEAST
TO THE SOUTHERN END OF THE LAKE AND A SEPARATE LOW OVER ONTARIO
MOVES EAST TO HUDSON BAY TONIGHT...WINDS WILL LIKELY CONTINUE TO
BE VARIABLE ACROSS THE LAKE. HOWEVER...IT DOES APPEAR THAT SPEEDS
WILL STAY ON THE LIGHTER SIDE THROUGH THIS PERIOD. THIS LOW WILL
THEN MOVE TO THE EASTERN LAKES MONDAY INTO MONDAY NIGHT AS HIGH
PRESSURE TO THE NORTHWEST BEGINS SPREADING SOUTHEAST...WITH
NORTHERLY WINDS SETTING UP ACROSS THE ENTIRE LAKE. AS THE SURFACE
GRADIENT TIGHTENS UP OVER THE LAKE LATE MONDAY AND MONDAY
NIGHT...NORTHERLY SPEEDS WILL BEGIN TO INCREASE. THIS INCREASING
TREND WITH THE NORTHERLY WINDS CONTINUES TUESDAY WITH 15 TO 25 KT
WINDS BECOMING LIKELY DURING THIS TIME.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1018 AM CDT SUN AUG 9 2015
.UPDATE...
959 AM CDT
THE CONVECTIVE COMPLEX OVERHEAD IS QUICKLY WARMING ALOFT THIS
MORNING WITH THE SYSTEM CONTINUING TO REFOCUS OVER CENTRAL IL.
RAIN HAS STRUGGLED TO SPREAD NORTH OF A ROCHELLE TO JOLIET TO DE
MOTTE INDIANA LINE THIS MORNING DESPITE A SURGING GRAVITY WAVE
ESQ BOUNDARY SHIFTING NORTHEAST EARLIER THIS MORNING. THE
BOUNDARY HAS WEAKENED CONSIDERABLY AND AREAS ALONG THE
AFOREMENTIONED LINE ARE JUST NOW POSSIBLY SEEING SOME SPRINKLES.
IN GENERAL THE RAIN WILL GRADUALLY WEAKEN AS IT SHIFTS EAST WITH
THE MAJORITY OF RAIN FALLING SOUTH OF A MENDOTA TO JOLIET TO DE
MOTTE INDIANA LINE. FAR NORTHEAST IL INCLUDING THE CHICAGO METRO
MAY SEE SOME SPRINKLES TO A LIGHT RAIN SHOWER CLOSER TO NOON...BUT
NOTHING OVERLY SIGNIFICANT. ISOLATED EMBEDDED THUNDERSTORMS ARE
ALSO POSSIBLE SOUTH OF THE MENDOTA...JOLIET...DE MOTTE LINE
THROUGH THE MORNING BUT NO SEVERE WEATHER IS EXPECTED.
GUIDANCE IS REALLY STRUGGLING WITH THE CONVECTIVE EVOLUTION GOING
INTO THIS AFTERNOON WITH THE RAP AND HRRR LOOKING THE MOST
REASONABLE THUS FAR. MADE MINOR TWEAKS TO PRECIP CHANCES THROUGH
THIS AFTN WITH THE FOCUS FOR EITHER FESTERING RAIN AND STORMS OR
SOME REDEVELOPMENT ALONG AND SOUTH OF I-80. KEPT A CHANCE OF
SHOWERS AND STORMS ACROSS THE CWA THIS AFTERNOON AS CONFIDENCE IS
LOW AS TO HOW FAR NORTH ACTIVITY WILL CONTINUE TO FESTER. WITH THE
MCV OVER CENTRAL IL...HAVE MUCH HIGHER CONFIDENCE IN AREAS SOUTH
OF I-80 SEEING THE MAJORITY OF ACTIVITY. DEBATED GOING DRY NORTH
OF I-88 THIS AFTN...BUT CANNOT RULE OUT A FEW SHOWERS AND PERHAPS
A STORM.
AS FAR AS STRONG TO SEVERE STORMS...CANNOT RULE OUT ONE OR TWO
STRONG STORMS...BUT THINKING WE WILL STRUGGLE TO RECOVER THIS AFTN
GIVEN THE THICK CLOUD COVER AND LINGERING RAIN. AGREE WITH THE
MARGINAL RISK FROM SPC. THINKING THE AREA OF CONCERN WOULD BE
SOUTH OF A STREATOR TO DE MOTTE LINE WITH THE BEST ACTIVITY WELL
SOUTH OF THE CWA OVER CENTRAL IL MUCH CLOSER TO THE MCV.
JEE
&&
.SHORT TERM...
358 AM CDT
THROUGH SUNDAY NIGHT...
TWO COMPLEXES OF SHOWERS AND THUNDERSTORMS ARE ONGOING EARLY THIS
MORNING THOUGH HAVE GENERALLY BEEN MERGING INTO ONE TO SOME
DEGREE...THOUGH STILL LOOK TO BE DISTINCT BASED ON THE LIGHTNING
AXES IN CENTRAL IOWA EXTENDING INTO WESTERN ILLINOIS..AND A
SEPARATE AREA IN SOUTHERN IOWA INTO NORTHERN MISSOURI.
AT THE MOMENT...THE NORTHERN EXTENT OF THE NORTHERN BATCH ENTERING
NW ILLINOIS IS IN A LESS HOSPITABLE ENVIRONMENT FOR CONTINUED FORWARD
PROPAGATION AND GROWTH AND BEING DRIVEN MORE SO FROM AN UPPER
LEVEL SHORTWAVE RIDING THE NORTHERN FRINGE OF THE RIDGE AXIS. THE
DEPTH OF THESE SHOWERS IS NOT IMPRESSIVE...AND EROSION ON THIS
ACTIVITY CONTINUES WITH JUST SOME LIGHT RAIN/SPRINKLES...WITH THE BEST
CHANCE FOR EROSION TO CONTINUE WILL BE IN NORTHERN ILLINOIS WITH
THE DRIEST AIRMASS AND MOST REMOVED FROM THE MAIN LOWER LEVEL
FORCING/BAROCLINIC ZONE. THE LLJ IS FOCUSED MORE-SO INTO THE
SOUTHERN MOST STORMS WHICH HAVE THE UPPER ENERGY SUPPORT COMBINED
WITH A BETTER THERMODYNAMIC ENVIRONMENT. LASALLE/LIVINGSTON/LEE
COUNTIES OR ON THE EASTERN EXTENT OF THE BETTER LLJ FORCING WHERE
MORE ORGANIZED AND SUSTAINED DEVELOPMENT WILL CONTINUE IN THE
COMING HOURS. MORE ROBUST DEVELOPMENT IS OCCURRING ON THE BACK
SIDE OF THIS COMPLEX WHERE A PORTION OF THE STRONGER LLJ WHICH
FEEDING THE SOUTHERN SYSTEM IS ABLE TO ADVECT NORTH INTO THE
NORTHERN STREAM ACTIVITY.
WITH THIS COMPLEX SETUP AT THE MOMENT...CONFIDENCE ON THE EVOLUTION
IS NOT AS HIGH AS I WOULD LIKE IT TO BE WITH MODELS STRUGGLING WITH
INITIALIZATIONS. THERE IS LITTLE TO SUGGEST THAT THESE SHOWERS AND
STORMS WON`T CONTINUE EASTWARD ONCE THE SHORTWAVE DRIVING IT
MOVES RIGHT ON THROUGH NE ILLINOIS...BUT DO PREFER THE HRRR
SOLUTION WHICH JUST BRINGS SOME LIGHTER RAIN NORTH (AND POSSIBLY
DRY IN FAR NORTH/NE ILLINOIS) AND FOCUSES ACTIVITY SOUTH THIS
MORNING. THE LLJ WHICH IS STILL STRONGEST IA BASED ON AREA VWPS
WILL BECOME ORIENTED SW-NE WITH THE MOISTURE CONVERGENCE AXIS
POINTED RIGHT AT US. THE INSTABILITY AXIS LOOKS TO BE POSITIONED
ACROSS THE CENTER OF THE CWA WHICH WILL LIKELY KEEP THE NORTHERN
AREAS JUST RAIN...WHEREAS POINTS SOUTH WILL AT LEAST SEE EMBEDDED
THUNDER DESPITE MARGINAL MID LEVEL LAPSE RATES. PRECIPITABLE WATER
VALUES ARE QUITE AN UPTICK THIS MORNING...SO THE I-80 SOUTHWARD
CORRIDOR MAY SEE SOME 1" PER HOUR RATES IN AN EFFICIENT
ENVIRONMENT.
SOME UNCERTAINTIES ON REMAINING FORCING IN THE AFTERNOON...AND
POTENTIAL FOR MORNING ACTIVITY TO KEEP ANY OUTFLOW FOCUSED SOUTH
OF THE AREA. THE LOCATION OF THE SURFACE FRONT MAY BECOME A BIT
MORE UNCERTAIN AFTER THESE STORMS LAY OUT ANY OUTFLOW. THE AIR
MASS WILL BE MOIST...THERE WILL BE SOME SHEAR AROUND...AND A LOW
LEVEL BOUNDARY...WHICH PRESENTS SOME CONCERNS WITH ANY ADDITIONAL
SUBTLE SHORTWAVES THAT MAY PASS THROUGH IN PROGRESSIVE WESTERLY
FLOW. HI-RES GUIDANCE IS RE-GENERATING STORMS IN IOWA THIS
AFTERNOON...AND DEPENDING ON WHERE THE SURFACE BOUNDARY ENDS UP
COULD POSE A MARGINAL SVR THREAT AS OUTLINED IN THE DAY 1 OUTLOOK
AND WILL NEED TO BE IRONED OUT BY THE DAY SHIFT.
AFTER WHAT COULD BE AN AFTERNOON LULL..THE SURFACE LOW TO OUR SOUTH
LIFTS NORTHEASTWARD SUNDAY NIGHT INTO EARLY MONDAY. ANOTHER
SHORTWAVE APPROACHES WITH THE INVERTED TROUGH AXIS POINTED RIGHT
OVER NORTHEAST ILLINOIS TONIGHT FOR POTENTIALLY A REINVIGORATION OF
SHOWERS...BUT STILL SOME UNCERTAINTY ON COVERAGE AT THIS POINT.
KMD
&&
.LONG TERM...
ONE LAST HOORAH AS THE UPPER LOW IN THE CANADIAN PRAIRIES LIFTS
TOWARD HUDSON BAY...OPENING THE DOOR FOR ONE LAST SHORTWAVE IN
NORTHWEST FLOW ALOFT TO MOVE THROUGH WISCONSIN COUPLED WITH
ADDITIONAL FAST MOVING WAVES COMING FROM THE PACIFIC. SLIGHTLY
BETTER LAPSE RATES ALOFT COUPLED WITH A SOUTHWARD MOVING COLD FRONT
WOULD SUGGEST THE POTENTIAL FOR SOME SCATTERED SHOWERS AND
THUNDERSTORMS MONDAY AFTERNOON/EARLY EVENING. SCATTERED MENTION DUE
TO THE TIMING/MOISTURE ISSUES AND THE FACT THE BETTER FORCING SWINGS
BY TO THE NORTH.
THE STRONG UPPER DISTURBANCE SOUTH OF HUDSON BAY WILL MOVE SOUTHEAST
ON MONDAY NIGHT INTO TUESDAY AND HIGH PRESSURE BUILDS IN FOR SEVERAL
DAYS. A HIGHLY AMPLIFIED PATTERN WILL SLOW THE PROGRESSION OF
SHORTWAVE ACTIVITY. WE WILL LARGELY BE UNDER THE INFLUENCE OF A
COMBINATION OF THE WESTERN U.S. RIDGE SUPPLYING THE DRY WEATHER AND
THE COOLING INFLUENCE OF NORTHWEST FLOW ON THE BACK SIDE OF THE
EASTERN U.S TROUGH. HIGHS WILL BE SLIGHTLY BELOW NORMAL WITH
COMFORTABLE HUMIDITY AND DECENT SUNSHINE. MOISTURE RETURN IS LACKING
UNTIL LATER IN THE WEEK WHEN A FRONTAL BOUNDARY DROPS THROUGH
THURSDAY NIGHT INTO FRIDAY. THIS WILL BE OUR NEXT CHANCE FOR SHOWERS
AND THUNDERSTORMS.
KMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* FOG WITH MVFR VIS THIS MORNING.
* WINDS VARIABLE TURNING EAST AT 7-9KT THIS AFTERNOON.
* SHOWERS THIS AFTERNOON INTO THE EVENING.
* FOG AND LOW CEILINGS TONIGHT...LOW END MVFR CEILINGS WITH IFR
POSSIBLE.
MM
//DISCUSSION...UPDATED 12Z...
LATEST RADAR IMAGERY DEPICTING PRECIP SHIELD STILL SLOWLY MOVING
EAST ACROSS NORTHERN ILLINOIS...WITH ITS EASTERN EXTENT STILL
ERODING AT THIS TIME. MOST GUIDANCE INCLUDING SHORT TERM...NOT
QUITE HANDLING EVOLUTION OF THIS PRECIP TOO WELL THIS
MORNING...BUT STILL THINKING PRECIP WILL REACH THE TERMINALS LATER
TODAY. PERSISTENT FORCING WILL CONTINUE THROUGH MIDDAY AND WHILE
THE COLUMN SATURATES...SHOULD BEGIN TO SEE PRECIP REACHING THE
TERMINALS BY LATE MORNING/MIDDAY. HOWEVER...COVERAGE MAY BE MORE
SCATTERED DURING THIS TIME. CONFIDENCE IS HIGHER THAT ANY THUNDER
TODAY WILL BE WELL SOUTH OF THE TERMINALS...AND HAVE CONTINUED TO
EXCLUDE FROM TAFS. WITH THIS SLOW MOVING SYSTEM ITS POSSIBLE AT
LEAST ISOLATED TO WIDELY SCATTERED SHOWERS MAY LINGER ACROSS THE
TERMINALS THROUGH THIS EVENING...BEFORE DEPARTING TO THE EAST. VFR
CONDITIONS TODAY WILL EVENTUALLY LOWER AND SLOWED THIS TREND THAN
WHAT GUIDANCE IS INDICATING...THINKING THE LOWER CEILINGS WONT
ARRIVE UNTIL LATER THIS EVENING WHEN SURFACE LOW/TROUGH MOVES
OVERHEAD. HAVE LOW END MVFR CEILINGS BUT DO THINK IFR WILL
EVENTUALLY BE POSSIBLE. DONT HAVE A GOOD FEEL WITH TIMING OF THIS
POSSIBLE IFR...AND SO HAVE LEFT OUT AT THIS TIME.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH WITH FOG/VIS THIS MORNING.
* HIGH WITH EASTERLY WIND DIRECTION...MEDIUM THAT SPEEDS STAY
BELOW 10KT.
* MEDIUM-LOW CONFIDENCE WITH SHOWERS THIS AFTERNOON/EVENING.
* HIGH CONFIDENCE WITH FOG AND LOW CEILINGS OCCURRING
TONIGHT...MEDIUM LOW WITH LOWEST HEIGHT AND TIMING/DURATION.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...SLIGHT CHANCE OF THUNDERSTORMS EARLY.
TUESDAY...VFR.
WEDNESDAY...VFR.
THURSDAY...VFR.
FRIDAY...CHANCE OF THUNDERSTORMS.
SATURDAY...VFR.
RODRIGUEZ
&&
.MARINE...
230 AM CDT
HIGHLY VARIABLE WIND FIELD ACROSS THE LAKE THIS MORNING AS A
WEAKER SURFACE PATTERN IN PLACE...WITH HIGH PRESSURE SITUATED TO
THE EAST AND NORTHEAST. THESE VARIABLE WINDS WILL LIKELY PERSIST
ACROSS THE NORTHERN HALF OF THE LAKE TODAY WHILE THE SOUTHERN END
BECOMES MORE SOUTHERLY THIS MORNING...AS LOW PRESSURE SLOWLY MOVES
EAST TOWARDS THE REGION. AS THIS THIS LOW CONTINUES EAST NORTHEAST
TO THE SOUTHERN END OF THE LAKE AND A SEPARATE LOW OVER ONTARIO
MOVES EAST TO HUDSON BAY TONIGHT...WINDS WILL LIKELY CONTINUE TO
BE VARIABLE ACROSS THE LAKE. HOWEVER...IT DOES APPEAR THAT SPEEDS
WILL STAY ON THE LIGHTER SIDE THROUGH THIS PERIOD. THIS LOW WILL
THEN MOVE TO THE EASTERN LAKES MONDAY INTO MONDAY NIGHT AS HIGH
PRESSURE TO THE NORTHWEST BEGINS SPREADING SOUTHEAST...WITH
NORTHERLY WINDS SETTING UP ACROSS THE ENTIRE LAKE. AS THE SURFACE
GRADIENT TIGHTENS UP OVER THE LAKE LATE MONDAY AND MONDAY
NIGHT...NORTHERLY SPEEDS WILL BEGIN TO INCREASE. THIS INCREASING
TREND WITH THE NORTHERLY WINDS CONTINUES TUESDAY WITH 15 TO 25 KT
WINDS BECOMING LIKELY DURING THIS TIME.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
231 AM CDT SUN AUG 9 2015
.SHORT TERM...
320 PM CDT
THROUGH SUNDAY...
MAIN CONCERN IS WITH CONVECTIVE POTENTIAL LATE TONIGHT INTO
SUNDAY. RAOBS AND AIRCRAFT SOUNDINGS TODAY SHOWED AN ENVIRONMENT
HOSTILE TO PRECIP MAINTENANCE. THEREFORE DESPITE SOME FORCING FROM
A CONVECTIVELY INDUCED SHORTWAVE OVERHEAD...LIGHT RADAR ECHOES
OVER AREA ARE LIKELY VIRGA AND HAVE PULLED MENTION OF SPRINKLES
THE REST OF TODAY. CONVERGENT AXIS IN FRONTAL ZONE OF DISSIPATING
WEAK LOW OVER SOUTHERN LAKE MICHIGAN DID INITIATIVE SOME
CONVECTION OVER NORTH CENTRAL INDIANA...AND WOULD EXPECT FURTHER
DEVELOPMENT TO REMAIN EAST OF THE CWA. OVERALL...WITH PLENTY OF
CLOUD COVER WELL BACK TO THE WEST...INCLUDING PATCHY LOWER CLOUDS
IN SPOTS...JUST EXPECTING A MOSTLY CLOUDY REST OF THE DAY INTO
TONIGHT. VERY WEAK GRADIENT WILL YIELD LIGHT/CALM WINDS OVERNIGHT
AND LOW DEWPOINT SPREADS COULD SET STAGE FOR SOME PATCHY FOG OR
HAZE. LOW TEMPS WILL BE IN THE MID 60S TO AROUND 70.
FOCUS LATE TONIGHT INTO SUNDAY WILL BE ON MCS EXPECTED TO DEVELOP
OVER EASTERN NEBRASKA AND WESTERN IOWA THIS EVENING. MCS IS LIKELY
TO RIDE ALONG INSTABILITY AXIS THAT WILL MAINLY BE SOUTH OF THE
CWA OFF TO THE EAST-SOUTHEAST INTO SUNDAY MORNING. CONSENSUS OF
MODEL GUIDANCE IS TO KEEP INSTABILITY MINIMAL AT BEST FOR MUCH OF
THE CWA...LIMITING THUNDER POTENTIAL. CANNOT COMPLETELY RULE OUT
THUNDER GIVEN MODEST LOW LEVEL JET/WAA REGIME. RECENT HI-RES
CAMS...INCLUDING 4KM NAM AND EXPERIMENTAL HRRR DEPICT A REASONABLE
SCENARIO IN WHICH STRATIFORM NORTH OF MCS OVERSPREADS MUCH OF CWA
FROM WESTNORTHWEST TO EAST SOUTHEAST AFTER MIDNIGHT THROUGH MID
SUNDAY MORNING/BY WHICH TIME IT WILL PROBABLY BE DECAYING. HAVE
FOCUSED CATEGORICAL POPS INTO SOUTHERN CWA WHERE CONFIDENCE IS
HIGHEST IN WIDESPREAD COVERAGE. ITS POSSIBLE FAR NORTHEAST CWA
COULD SEE LITTLE OR NO RAIN. BEST CHANCE FOR HEAVY DOWNPOURS LOOKS
TO BE IN FAR SOUTHERN CWA WHERE MORE ROBUST CONVECTION COULD PASS
THROUGH...THOUGH ANY THREAT FOR STRONG TO SEVERE STORMS SHOULD
STAY SOUTHWEST OF THE CWA GIVEN ANTICIPATED DECAYING TREND OF MCS.
A GOOD DEAL OF UNCERTAINTY THE REMAINDER OF SUNDAY REGARDING
CONVECTIVE TRENDS. A SURFACE LOW LOOKS TO EVOLVE EASTWARD INTO THE
MID MISSISSIPPI VALLEY BY LATER IN THE DAY...WITH RETURN FLOW AND
WEST-SOUTHWEST LLJ ALSO DEVELOPING. LINGERING CLOUD COVER WILL
LIMIT DESTABILIZATION AND THUNDER POTENTIAL...ESPECIALLY FARTHER
NORTH UNTIL LATE DAY. ANOTHER SHORTWAVE WILL APPROACH FROM WEST IN
LATE AFTERNOON AND THERE SHOULD BE ENOUGH 925-850 MB MOISTURE
CONVERGENCE TO SUPPORT CHANCE POPS NORTH OF I-80 AND LIKELIESSOUTH
OF I-80. MODERATE WESTERLY MIDLEVEL FLOW WILL RESULT IN 30-40 KT
OF WEST-NORTHWEST 0-6KM SHEAR. THIS WILL SUPPORT SOME THREAT FOR
STRONG TO SEVERE STORMS WELL SOUTH OF I-80 CLOSER TO EXPECTED
TRACK OF SFC LOW AND WHERE TEMPS AROUND 80 AND LOW-MID 70S
DEWPOINTS COULD BRING SLIGHTLY BETTER INSTABILITY. MAIN THREAT
WOULD BE GUSTY TO DAMAGING WINDS...AS HAIL APPEARS UNLIKELY WITH
700-500 MB LAPSE RATES LESS THAN 6 CELSIUS PER KM. SUNDAY OVERALL
WILL BE A CLOUDY AND MUGGY DAY...WITH HIGHS IN THE MID 70S TO
AROUND 80.
RC
&&
.LONG TERM...
320 PM CDT
SUNDAY NIGHT THROUGH SATURDAY...
THE BEST CHANCE FOR PRECIP IN THE EXTENDED WILL BE SUNDAY EVENING
THROUGH MONDAY AFTERNOON...WITH VERY SLIGHT CHANCES OF PRECIP LATE
NEXT WEEK.
A COMPLEX OF STORMS WILL BE DIMINISHING OVER THE REGION SUNDAY
EVENING AND NIGHT. THE UPPER LEVEL VORTICITY PATTERN IS VERY CHAOTIC
WITH GUIDANCE INDICATING THE MAIN MCV WILL BE OVER CENTRAL IL AND
VORT STREAMERS ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE OVER
WISCONSIN. WITH SUCH A MESSY PATTERN...DECIDED TO ONLY MAKE MINOR
ADJUSTMENTS TO PRECIP CHANCES SUNDAY NIGHT. HAVE A CHANCE OF
THUNDERSTORMS ALONG AND EAST OF I-39 WITH BETTER CHANCES EAST OF I-
55. COULD SEE A FEW STRONG TO SEVERE STORMS SOUTH OF I-80 BUT
CONDITIONS WILL BE WEAKENING AS THE EVENING PROGRESSES.
OVERALL...HAVE LOW CONFIDENCE IN EXACTLY HOW SUNDAY NIGHT WILL PLAY
OUT DUE TO SO MANY MESOSCALE FEATURES AND WHETHER OR NOT THE
ATMOSPHERE WILL BE ABLE TO RECOVER FROM SUNDAY MORNING/S STORMS.
A SHORT WAVE MOVING WITH THE UPPER LEVEL TROUGH ROTATES THROUGH
MONDAY WITH A DECENT VORTICITY STREAMER. WENT WITH A CHANCE OF
SHOWERS AND STORMS MAINLY NORTH OF I-80 MONDAY. THINKING THE NAM IS
ONCE AGAIN TOO MOIST LEADING TO TOO MUCH CONVECTIVE DEVELOPMENT.
THINKING SHOWERS AND STORMS WILL DRIFT SOUTH OF THE IL/WI STATE LINE
MONDAY AFTERNOON AND THEN WEAKEN AS THEY CONTINUE TO SHIFT SOUTH
MONDAY EVENING. MONDAY EVENING MAY END UP BEING DRY...BUT DID NOT
HAVE ENOUGH CONFIDENCE IN A DRY FORECAST SO KEPT A SLIGHT CHANCE OF
SHOWERS AND STORMS ALONG AND SOUTH OF I-80 MONDAY EVENING.
THE UPPER LEVEL TROUGH AXIS SHIFTS EAST THROUGH WISCONSIN WITH
COOLER UPPER LEVEL AIR SINKING SOUTH THROUGH THE REGION. HIGH
PRESSURE THEN BUILDS IN FOR WEDNESDAY AND THURSDAY LEADING TO DRY
CONDITIONS THROUGH THURSDAY. HIGH TEMPS TUESDAY WILL BE AROUND
80...THEN IN THE UPPER 70S WEDNESDAY. LAKE BREEZES BOTH DAYS WILL
KEEP LOCATIONS ALONG THE LAKE IN THE MID 70S. TEMPS REBOUND INTO
THE LOW TO MID 80S THURSDAY WITH NO LAKE COOLING.
THE NEXT LOW PRESSURE SYSTEM MOVES OVER JAMES BAY THURSDAY EVENING
AND PUSHES THE HIGH PRESSURE SOUTH OVER THE OHIO VALLEY. THE LOWS
COLD FRONT SINKS SOUTH OVER FAR NORTHERN IL FRIDAY AFTERNOON SO HAVE
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND STORMS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHORT PERIOD OF MVFR CEILINGS IN THE NEAR TERM...MAINLY FOR
ORD.
* PERIOD OF RAIN LIKELY THIS MORNING...POSSIBLY WITH MVFR VIS.
* CHANCE OF SHOWERS AGAIN LATER IN THE DAY...ISOLATED THUNDER
POSSIBLE BUT MORE LIKELY SOUTH OF TERMINALS.
* LOW CEILINGS BECOMING LIKELY LATER TODAY WITH MVFR LIKELY...AND
POSSIBLY IFR.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
BULK OF ANY PRECIP ACTIVITY REMAINING TO THE WEST OF THE TERMINALS
EARLY THIS MORNING...WHILE GENERALLY VFR CONDITIONS IN PLACE.
HOWEVER...SOME ISOLATED MVFR CEILINGS ARE REMAIN AROUND THE
TERMINALS AND WHILE FOG IS DEVELOPING ACROSS THE AREA. FOG WILL
LIKELY REMAIN THROUGH THE MORNING WHILE THE PRECIP OVER THE
IOWA/ILLINOIS BORDER SLOWLY SHIFTS EAST. TRYING TO GET A TIME OF
ARRIVAL ON THE LEADING EDGE...BUT EASTERN EDGE CONTINUES TO ERODE.
HAVE MAINTAINED SIMILAR TIMING TO PREVIOUS FORECAST...WITH SHORT
TERM GUIDANCE LIKEWISE SUPPORTING THIS TIMING. STILL FEEL GOOD
WITH KEEPING THUNDER OUT OF THE TAFS AS INSTABILITY IS TO THE
WEST/SOUTH OF THE TERMINALS. AS THIS PUSHES THROUGH THIS
MORNING...UPSTREAM DEVELOPMENT WILL PROVIDE ADDITIONAL CHANCES FOR
PRECIP LATER THIS AFTERNOON INTO EARLY EVENING. HAVE MAINTAINED
SIMILAR START TIMES AND EVEN KEPT THUNDER OUT OF THE TAFS...WITH
THE EXCEPTION OF GYY WHERE A SLIGHTLY HIGHER CHANCE WILL RESIDE.
DID LOWER CEILINGS THOUGH LATER THIS AFTERNOON INTO THE EVENING AS
ITS APPEARING POSSIBLE THAT A PERIOD OF LOW STRATUS WILL SET
UP...ALTHOUGH CONFIDENCE IS LOW WITH REGARD TO HOW LOW CEILINGS
WILL GET. SURFACE WIND FIELD THIS MORNING THROUGH THIS EVENING
LOOKS TO BE HIGHLY VARIABLE WITH A WEAK SURFACE PATTERN AND THEN
APPROACHING SYSTEM...BUT SPEEDS STILL LOOK TO REMAIN UNDER 10 KT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE WITH CEILINGS IN THE NEAR TERM.
* MEDIUM IN RAIN COVERAGE/TIMING AND MVFR POTENTIAL THIS MORNING.
* MEDIUM-LOW IN WINDS TODAY...THOUGH SHOULD BE GENERALLY LESS
THAN 10 KTS.
* LOW IN SHRA/ISOLATED TSRA COVERAGE SUNDAY AFTERNOON/EVE.
* HIGH WITH MVFR CEILINGS LATER TODAY...LOW ON IFR.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF SHRA/TSRA AND MVFR. NORTH-NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTHEAST WINDS.
THURSDAY...VFR. WEST-SOUTHWEST WINDS.
FRIDAY...SLIGHT CHANCE TSRA. WEST-SOUTHWEST WINDS.
RATZER
&&
.MARINE...
230 AM CDT
HIGHLY VARIABLE WIND FIELD ACROSS THE LAKE THIS MORNING AS A
WEAKER SURFACE PATTERN IN PLACE...WITH HIGH PRESSURE SITUATED TO
THE EAST AND NORTHEAST. THESE VARIABLE WINDS WILL LIKELY PERSIST
ACROSS THE NORTHERN HALF OF THE LAKE TODAY WHILE THE SOUTHERN END
BECOMES MORE SOUTHERLY THIS MORNING...AS LOW PRESSURE SLOWLY MOVES
EAST TOWARDS THE REGION. AS THIS THIS LOW CONTINUES EAST NORTHEAST
TO THE SOUTHERN END OF THE LAKE AND A SEPARATE LOW OVER ONTARIO
MOVES EAST TO HUDSON BAY TONIGHT...WINDS WILL LIKELY CONTINUE TO
BE VARIABLE ACROSS THE LAKE. HOWEVER...IT DOES APPEAR THAT SPEEDS
WILL STAY ON THE LIGHTER SIDE THROUGH THIS PERIOD. THIS LOW WILL
THEN MOVE TO THE EASTERN LAKES MONDAY INTO MONDAY NIGHT AS HIGH
PRESSURE TO THE NORTHWEST BEGINS SPREADING SOUTHEAST...WITH
NORTHERLY WINDS SETTING UP ACROSS THE ENTIRE LAKE. AS THE SURFACE
GRADIENT TIGHTENS UP OVER THE LAKE LATE MONDAY AND MONDAY
NIGHT...NORTHERLY SPEEDS WILL BEGIN TO INCREASE. THIS INCREASING
TREND WITH THE NORTHERLY WINDS CONTINUES TUESDAY WITH 15 TO 25 KT
WINDS BECOMING LIKELY DURING THIS TIME.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
100 AM CDT SUN AUG 9 2015
.SHORT TERM...
320 PM CDT
THROUGH SUNDAY...
MAIN CONCERN IS WITH CONVECTIVE POTENTIAL LATE TONIGHT INTO
SUNDAY. RAOBS AND AIRCRAFT SOUNDINGS TODAY SHOWED AN ENVIRONMENT
HOSTILE TO PRECIP MAINTENANCE. THEREFORE DESPITE SOME FORCING FROM
A CONVECTIVELY INDUCED SHORTWAVE OVERHEAD...LIGHT RADAR ECHOES
OVER AREA ARE LIKELY VIRGA AND HAVE PULLED MENTION OF SPRINKLES
THE REST OF TODAY. CONVERGENT AXIS IN FRONTAL ZONE OF DISSIPATING
WEAK LOW OVER SOUTHERN LAKE MICHIGAN DID INITIATIVE SOME
CONVECTION OVER NORTH CENTRAL INDIANA...AND WOULD EXPECT FURTHER
DEVELOPMENT TO REMAIN EAST OF THE CWA. OVERALL...WITH PLENTY OF
CLOUD COVER WELL BACK TO THE WEST...INCLUDING PATCHY LOWER CLOUDS
IN SPOTS...JUST EXPECTING A MOSTLY CLOUDY REST OF THE DAY INTO
TONIGHT. VERY WEAK GRADIENT WILL YIELD LIGHT/CALM WINDS OVERNIGHT
AND LOW DEWPOINT SPREADS COULD SET STAGE FOR SOME PATCHY FOG OR
HAZE. LOW TEMPS WILL BE IN THE MID 60S TO AROUND 70.
FOCUS LATE TONIGHT INTO SUNDAY WILL BE ON MCS EXPECTED TO DEVELOP
OVER EASTERN NEBRASKA AND WESTERN IOWA THIS EVENING. MCS IS LIKELY
TO RIDE ALONG INSTABILITY AXIS THAT WILL MAINLY BE SOUTH OF THE
CWA OFF TO THE EAST-SOUTHEAST INTO SUNDAY MORNING. CONSENSUS OF
MODEL GUIDANCE IS TO KEEP INSTABILITY MINIMAL AT BEST FOR MUCH OF
THE CWA...LIMITING THUNDER POTENTIAL. CANNOT COMPLETELY RULE OUT
THUNDER GIVEN MODEST LOW LEVEL JET/WAA REGIME. RECENT HI-RES
CAMS...INCLUDING 4KM NAM AND EXPERIMENTAL HRRR DEPICT A REASONABLE
SCENARIO IN WHICH STRATIFORM NORTH OF MCS OVERSPREADS MUCH OF CWA
FROM WESTNORTHWEST TO EAST SOUTHEAST AFTER MIDNIGHT THROUGH MID
SUNDAY MORNING/BY WHICH TIME IT WILL PROBABLY BE DECAYING. HAVE
FOCUSED CATEGORICAL POPS INTO SOUTHERN CWA WHERE CONFIDENCE IS
HIGHEST IN WIDESPREAD COVERAGE. ITS POSSIBLE FAR NORTHEAST CWA
COULD SEE LITTLE OR NO RAIN. BEST CHANCE FOR HEAVY DOWNPOURS LOOKS
TO BE IN FAR SOUTHERN CWA WHERE MORE ROBUST CONVECTION COULD PASS
THROUGH...THOUGH ANY THREAT FOR STRONG TO SEVERE STORMS SHOULD
STAY SOUTHWEST OF THE CWA GIVEN ANTICIPATED DECAYING TREND OF MCS.
A GOOD DEAL OF UNCERTAINTY THE REMAINDER OF SUNDAY REGARDING
CONVECTIVE TRENDS. A SURFACE LOW LOOKS TO EVOLVE EASTWARD INTO THE
MID MISSISSIPPI VALLEY BY LATER IN THE DAY...WITH RETURN FLOW AND
WEST-SOUTHWEST LLJ ALSO DEVELOPING. LINGERING CLOUD COVER WILL
LIMIT DESTABILIZATION AND THUNDER POTENTIAL...ESPECIALLY FARTHER
NORTH UNTIL LATE DAY. ANOTHER SHORTWAVE WILL APPROACH FROM WEST IN
LATE AFTERNOON AND THERE SHOULD BE ENOUGH 925-850 MB MOISTURE
CONVERGENCE TO SUPPORT CHANCE POPS NORTH OF I-80 AND LIKELIESSOUTH
OF I-80. MODERATE WESTERLY MIDLEVEL FLOW WILL RESULT IN 30-40 KT
OF WEST-NORTHWEST 0-6KM SHEAR. THIS WILL SUPPORT SOME THREAT FOR
STRONG TO SEVERE STORMS WELL SOUTH OF I-80 CLOSER TO EXPECTED
TRACK OF SFC LOW AND WHERE TEMPS AROUND 80 AND LOW-MID 70S
DEWPOINTS COULD BRING SLIGHTLY BETTER INSTABILITY. MAIN THREAT
WOULD BE GUSTY TO DAMAGING WINDS...AS HAIL APPEARS UNLIKELY WITH
700-500 MB LAPSE RATES LESS THAN 6 CELSIUS PER KM. SUNDAY OVERALL
WILL BE A CLOUDY AND MUGGY DAY...WITH HIGHS IN THE MID 70S TO
AROUND 80.
RC
&&
.LONG TERM...
320 PM CDT
SUNDAY NIGHT THROUGH SATURDAY...
THE BEST CHANCE FOR PRECIP IN THE EXTENDED WILL BE SUNDAY EVENING
THROUGH MONDAY AFTERNOON...WITH VERY SLIGHT CHANCES OF PRECIP LATE
NEXT WEEK.
A COMPLEX OF STORMS WILL BE DIMINISHING OVER THE REGION SUNDAY
EVENING AND NIGHT. THE UPPER LEVEL VORTICITY PATTERN IS VERY CHAOTIC
WITH GUIDANCE INDICATING THE MAIN MCV WILL BE OVER CENTRAL IL AND
VORT STREAMERS ASSOCIATED WITH THE UPPER LEVEL TROUGH WILL BE OVER
WISCONSIN. WITH SUCH A MESSY PATTERN...DECIDED TO ONLY MAKE MINOR
ADJUSTMENTS TO PRECIP CHANCES SUNDAY NIGHT. HAVE A CHANCE OF
THUNDERSTORMS ALONG AND EAST OF I-39 WITH BETTER CHANCES EAST OF I-
55. COULD SEE A FEW STRONG TO SEVERE STORMS SOUTH OF I-80 BUT
CONDITIONS WILL BE WEAKENING AS THE EVENING PROGRESSES.
OVERALL...HAVE LOW CONFIDENCE IN EXACTLY HOW SUNDAY NIGHT WILL PLAY
OUT DUE TO SO MANY MESOSCALE FEATURES AND WHETHER OR NOT THE
ATMOSPHERE WILL BE ABLE TO RECOVER FROM SUNDAY MORNING/S STORMS.
A SHORT WAVE MOVING WITH THE UPPER LEVEL TROUGH ROTATES THROUGH
MONDAY WITH A DECENT VORTICITY STREAMER. WENT WITH A CHANCE OF
SHOWERS AND STORMS MAINLY NORTH OF I-80 MONDAY. THINKING THE NAM IS
ONCE AGAIN TOO MOIST LEADING TO TOO MUCH CONVECTIVE DEVELOPMENT.
THINKING SHOWERS AND STORMS WILL DRIFT SOUTH OF THE IL/WI STATE LINE
MONDAY AFTERNOON AND THEN WEAKEN AS THEY CONTINUE TO SHIFT SOUTH
MONDAY EVENING. MONDAY EVENING MAY END UP BEING DRY...BUT DID NOT
HAVE ENOUGH CONFIDENCE IN A DRY FORECAST SO KEPT A SLIGHT CHANCE OF
SHOWERS AND STORMS ALONG AND SOUTH OF I-80 MONDAY EVENING.
THE UPPER LEVEL TROUGH AXIS SHIFTS EAST THROUGH WISCONSIN WITH
COOLER UPPER LEVEL AIR SINKING SOUTH THROUGH THE REGION. HIGH
PRESSURE THEN BUILDS IN FOR WEDNESDAY AND THURSDAY LEADING TO DRY
CONDITIONS THROUGH THURSDAY. HIGH TEMPS TUESDAY WILL BE AROUND
80...THEN IN THE UPPER 70S WEDNESDAY. LAKE BREEZES BOTH DAYS WILL
KEEP LOCATIONS ALONG THE LAKE IN THE MID 70S. TEMPS REBOUND INTO
THE LOW TO MID 80S THURSDAY WITH NO LAKE COOLING.
THE NEXT LOW PRESSURE SYSTEM MOVES OVER JAMES BAY THURSDAY EVENING
AND PUSHES THE HIGH PRESSURE SOUTH OVER THE OHIO VALLEY. THE LOWS
COLD FRONT SINKS SOUTH OVER FAR NORTHERN IL FRIDAY AFTERNOON SO HAVE
A SLIGHT CHANCE TO CHANCE OF SHOWERS AND STORMS.
JEE
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* SHORT PERIOD OF MVFR CEILINGS IN THE NEAR TERM...MAINLY FOR
ORD.
* PERIOD OF RAIN LIKELY THIS MORNING...POSSIBLY WITH MVFR VIS.
* CHANCE OF SHOWERS AGAIN LATER IN THE DAY...ISOLATED THUNDER
POSSIBLE BUT MORE LIKELY SOUTH OF TERMINALS.
* LOW CEILINGS BECOMING LIKELY LATER TODAY WITH MVFR LIKELY...AND
POSSIBLY IFR.
RODRIGUEZ
//DISCUSSION...UPDATED 06Z...
BULK OF ANY PRECIP ACTIVITY REMAINING TO THE WEST OF THE TERMINALS
EARLY THIS MORNING...WHILE GENERALLY VFR CONDITIONS IN PLACE.
HOWEVER...SOME ISOLATED MVFR CEILINGS ARE REMAIN AROUND THE
TERMINALS AND WHILE FOG IS DEVELOPING ACROSS THE AREA. FOG WILL
LIKELY REMAIN THROUGH THE MORNING WHILE THE PRECIP OVER THE
IOWA/ILLINOIS BORDER SLOWLY SHIFTS EAST. TRYING TO GET A TIME OF
ARRIVAL ON THE LEADING EDGE...BUT EASTERN EDGE CONTINUES TO ERODE.
HAVE MAINTAINED SIMILAR TIMING TO PREVIOUS FORECAST...WITH SHORT
TERM GUIDANCE LIKEWISE SUPPORTING THIS TIMING. STILL FEEL GOOD
WITH KEEPING THUNDER OUT OF THE TAFS AS INSTABILITY IS TO THE
WEST/SOUTH OF THE TERMINALS. AS THIS PUSHES THROUGH THIS
MORNING...UPSTREAM DEVELOPMENT WILL PROVIDE ADDITIONAL CHANCES FOR
PRECIP LATER THIS AFTERNOON INTO EARLY EVENING. HAVE MAINTAINED
SIMILAR START TIMES AND EVEN KEPT THUNDER OUT OF THE TAFS...WITH
THE EXCEPTION OF GYY WHERE A SLIGHTLY HIGHER CHANCE WILL RESIDE.
DID LOWER CEILINGS THOUGH LATER THIS AFTERNOON INTO THE EVENING AS
ITS APPEARING POSSIBLE THAT A PERIOD OF LOW STRATUS WILL SET
UP...ALTHOUGH CONFIDENCE IS LOW WITH REGARD TO HOW LOW CEILINGS
WILL GET. SURFACE WIND FIELD THIS MORNING THROUGH THIS EVENING
LOOKS TO BE HIGHLY VARIABLE WITH A WEAK SURFACE PATTERN AND THEN
APPROACHING SYSTEM...BUT SPEEDS STILL LOOK TO REMAIN UNDER 10 KT.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM CONFIDENCE WITH CEILINGS IN THE NEAR TERM.
* MEDIUM IN RAIN COVERAGE/TIMING AND MVFR POTENTIAL THIS MORNING.
* MEDIUM-LOW IN WINDS TODAY...THOUGH SHOULD BE GENERALLY LESS
THAN 10 KTS.
* LOW IN SHRA/ISOLATED TSRA COVERAGE SUNDAY AFTERNOON/EVE.
* HIGH WITH MVFR CEILINGS LATER TODAY...LOW ON IFR.
RODRIGUEZ
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY...CHANCE OF SHRA/TSRA AND MVFR. NORTH-NORTHEAST WINDS.
TUESDAY AND WEDNESDAY...VFR. NORTHEAST WINDS.
THURSDAY...VFR. WEST-SOUTHWEST WINDS.
FRIDAY...SLIGHT CHANCE TSRA. WEST-SOUTHWEST WINDS.
RATZER
&&
.MARINE...
320 PM CDT
HIGH PRESSURE STRETCHES FROM QUEBEC THROUGH THE OHIO VALLEY WHILE
LOW PRESSURE IS OVER MANITOBA. BOTH SYSTEMS WILL SHIFT EAST WITH THE
LOW REACHING JAMES BAY BY MONDAY MORNING. AS SUCH LIGHT NORTHEAST
WINDS BECOME SOUTH TO SOUTHEAST SUNDAY. THE TROUGH ASSOCIATED WITH
THE LOWS COLD/STATIONARY FRONT SHIFTS THROUGH LATE SUNDAY NIGHT INTO
MONDAY MORNING WITH WINDS BECOMING NORTH BEHIND IT. A WEAK CLOSED
LOW FORMS OVER THE EASTERN GREAT LAKES MONDAY EVENING AND DEEPENS AS
IT SHIFTS NORTHEAST. AT THE SAME TIME HIGH PRESSURE WILL BE PUSHING
EAST OVER THE WESTERN GREAT LAKES. THIS WILL LEAD TO NORTH WINDS
INCREASING TO 10 TO 20 KT MONDAY NIGHT THROUGH TUESDAY NIGHT. WINDS
WEAKEN WEDNESDAY WITH THE HIGH OVERHEAD...AND THEN BACK TO SOUTHWEST
AS THE HIGH IS PUSHED SOUTH BY THE NEXT LOW OVER JAMES BAY THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
1104 PM CDT SAT AUG 8 2015
.UPDATE...
ISSUED AT 835 PM CDT SAT AUG 8 2015
WEAK SURFACE WIND SHIFT STILL DEPICTED ON THE LASTEST SURFACE
ANALYSIS OVER PARTS OF EAST CENTRAL THROUGH SOUTH CENTRAL IL
EARLY THIS EVENING. HAD A FEW LIGHT SHOWERS DEVELOP ALONG IT
EARLIER BUT NOT MUCH SINCE THEN. A BAND OF MID LEVEL CLOUDS
AND OCCASIONAL LIGHT SHOWERS STRETCHED FROM EAST CENTRAL IOWA
INTO PARTS OF CENTRAL ILLINOIS. THE STRONGER LOW LEVEL WARM
ADVECTION AND MOISTURE CONVERGENCE IS WELL OUT WEST OF OUR
AREA OVER THE MISSOURI RIVER VALLEY WHERE JUST RECENTLY CONVECTION
HAS FINALLY DEVELOPED OVER FAR SOUTHEAST NEBRASKA. THAT AREA
SHOULD INCREASE IN COVERAGE AS IT PUSHES EAST LATE THIS EVENING
WITH OUR AREA SEEING THE BULK OF THE SHOWERS AND STORMS DURING
THE MORNING HOURS OF SUNDAY. PRECIPITABLE WATER VALUES OF OVER
2 INCHES NOTED OVER PARTS OF SOUTHEAST NEBRASKA INTO WESTERN IOWA
WITH FORECAST MODELS SUGGESTING SIMILAR VALUES AS THE CONVECTIVE
SYSTEM ARRIVES IN OUR AREA EARLY SUNDAY MORNING. RAINFALL AMOUNTS
OF 1 TO 2 INCHES WILL BE POSSIBLE OVER PARTS OF WEST CENTRAL IL
BY SUNDAY MORNING WITH SOME OF THE MORE INTENSE THUNDERSTORMS.
HAVE MADE SOME MINOR ADJUSTMENTS TO THE GRIDS WITH RESPECT TO
TIMING OF THE MORE WIDESPREAD SHOWERS AND STORMS LATE TONIGHT AND
ADDED SOME LIGHTER SHOWERS FURTHER SOUTH AND EAST TO TAKE INTO
ACCOUNT THE WIDELY SCATTERED SHOWERS NOW OCCURRING WITH SOME OF
THE MID LEVEL CLOUDS TRACKING ESE ACROSS THE REGION THIS EVE.
SHOULD HAVE THE UPDATED ZONES OUT BY 900 PM.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 307 PM CDT SAT AUG 8 2015
REMNANTS OF AN MCS OVER EASTERN MO AT MID AFTERNOON HAS ISOLATED
LIGHT SHOWERS AND SPRINKLES OVER CENTRAL IL WEST OF I-57 AND
DRIFTING EASTWARD. MOST OF OUR AREA SHOULD STAY DRY INTO THIS
EVENING WITH JUST A FEW LIGHT SHOWERS OR SPRINKLES POSSIBLE OVER
PARTS OF CENTRAL IL WITH PARTLY TO MOSTLY CLOUDY SKIES. ANOTHER MCS
WILL LIKELY DEVELOP OVER WESTERN IA AND FAR EASTERN NEBRASKA ON NOSE
OF AN 35-45 KT 850 MB SW JET THIS EVENING AND TRACK ESE ACROSS IA
AND EVENTUALLY INTO CENTRAL IL DURING OVERNIGHT. 4KM WRF AND TAIL
END OF HRRR MODEL SHOWS MOST OF CONVECTION SREADING EAST TOWARD IL
RIVER VALLEY BETWEEN 08Z-10Z AND APPROACHING I-57 AROUND 12Z.
CONTINUED MENTION OF HEAVY RAIN FROM PEORIA NW LATE TONIGHT AFTER
09Z/4 AM WITH QPF OVERNIGHT HALF TO THREE QUARTER INCHES AND LOCALLY
1 INCH FROM GALESBURG AND MACOMB WEST. SPC HAS MARGINAL RISK OF
SEVERE STORMS OVERNIGHT WEST OF PEORIA AND SPRINGFIELD FOR GUSTY
WINDS AND SMALL HAIL WHILE SLIGHT RISK OF SEVERE IS FROM QUINCY
WESTWARD ACROSS NORTHERN MO AND SOUTHERN IA. SE IL/WABASH RIVER
VALLEY WILL LIKELY STAY DRY MOST OF TONIGHT AND PATCHY FOG COULD
FORM OVERNIGHT IN FAR SOUTHEAST IL WHERE LESS CLOUD COVER. MUGGY
LOWS TONIGHT IN THE UPPER 60S AND LOWER 70S WHICH IS CLOSE TO
CURRENT DEWPOINTS AND LIGHT WINDS TONIGHT.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 307 PM CDT SAT AUG 8 2015
A THUNDERSTORM COMPLEX/MCS IS EXPECTED TO TRACK EASTWARD ACROSS
ILLINOIS SUNDAY MORNING...LIKELY WEAKENING THROUGH THE DAYTIME.
ALTHOUGH STILL WAITING FOR THIS SYSTEM TO DEVELOP AROUND EASTERN
NB/WESTERN IA THIS EVENING...RECENT TRENDS HAVE BEEN FOR SIMILAR
SYSTEMS TO DEVELOP SLIGHTLY SOUTHWARD FROM EARLY FORECASTS...AND
LATEST MODEL RUNS HINT AT THIS AS WELL. THEREFORE...HAVE TRENDED
HEAVIER PRECIPITATION AMOUNTS A BIT SOUTHWARD FROM PREVIOUS PACKAGE
WITH AMOUNTS FROM AROUND 1 TO 1.5 INCHES POSSIBLE NORTH OF I-72 AND
WEST OF I-55 BY NOON SUNDAY...WITH THE HIGHER END OF THAT RANGE MORE
LIKELY TOWARD THE GALESBURG AREA. LOWER AMOUNTS AND LOWER
PRECIPITATION CHANCES EXPECTED WITH THIS SYSTEM SOUTH OF I-72 TOWARD
THE EFFINGHAM/I-70 AREA.
A BIT OF A BREAK IN THUNDERSTORM ACTIVITY LIKELY FOR MIDDAY SUNDAY
AS THE OVERNIGHT SYSTEM MOVES OFF TO THE EAST. EXACT TIMING...CLOUD
COVER LEFT BEHIND...AND BOUNDARIES LEFT BEHIND FROM THE OVERNIGHT
SYSTEM WILL IMPACT THE POSSIBILITY OF ANOTHER THUNDERSTORM COMPLEX
DEVELOPING SUNDAY NIGHT. CURRENT MODEL CONSENSUS FORMS THIS FARTHER
SOUTH TOWARD THE OHIO VALLEY AREA AND HAVE TRENDED PRECIP CHANCES
TOWARD THAT AREA FOR SUNDAY NIGHT INTO MONDAY.
AFTER THAT...UPPER RIDGING WILL BUILD OVER THE CENTRAL CONUS AND
DEEP TROUGHING WILL DEVELOP DOWNSTREAM ACROSS THE GREAT LAKES/OHIO
RIVER VALLEY. AS A RESULT...MUCH OF THE EXTENDED BEYOND MONDAY IS
COOL/DRY. GFS/ECMWF SHOW THE NEXT FRONTAL BOUNDARY DROPPING INTO
THE GREAT LAKES AREA JUST NORTH OF CENTRAL IL FRIDAY. HOWEVER...BOTH
LARGELY DISSIPATE THE FEATURE AND WILL MENTION JUST A SLIGHT CHANCE
POP ACROSS THE NORTHERN HALF OF THE CWA ON FRIDAY UNTIL BETTER MODEL
CONSISTENCY IS ACHIEVED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1100 PM CDT SAT AUG 8 2015
AREA OF SHOWERS AND THUNDERSTORMS WAS BEGINNING TO INCREASE IN
COVERAGE ACROSS IOWA AND SHOULD CONTINUE TO PUSH EAST INTO OUR
AREA OVERNIGHT AND THRU MOST OF SUNDAY MORNING. THE MAIN FORECAST
CONCERN WILL BE AFFECT ON CIGS/VSBYS ACROSS THE TAF SITES INTO
EARLY SUNDAY AFTERNOON. WITH THE ONSET OF THE MORE SIGNIFICANT
RAINS AND TSRA AFTER 08Z...IT APPEARS MOST AREAS WILL EXPERIENCE
A DROP TO MVFR AND OCCASIONALLY IFR CIGS. THAT SHOULD CONTINUE
INTO EARLY AFTERNOON AND AS THE SYSTEM SHIFTS OFF TO OUR EAST...
WE SHOULD THEN SEE A GRADUAL IMPROVEMENT IN CIGS ACROSS THE
AREA. SOME OF THE SHORT TERM FORECAST MODELS NOW SUGGESTING
THE POTENTIAL FOR A BAND OF LOW LEVEL CLOUDS (1000-2000 FEET)
MAY AFFECT CMI AND BMI IN THE 05-08Z TIME FRAME BEFORE THE
MORE WIDESPREAD RAINS AND THUNDER ARRIVE. RIGHT NOW WILL
INTRODUCE A SCATTERED GROUP AT 600-1000 FEET AT BOTH SITES.
SURFACE WINDS WILL ONCE AGAIN BE A NON-FACTOR...UNLESS ONE OF THE
TAF SITES IS AFFECTED BY A STRONGER THUNDERSTORM LATE TONIGHT.
THEN WE COULD SEE SOME GUSTY WINDS WITH A VARIABLE DIRECTION.
OTHERWISE...AN EAST TO SOUTHEAST DIRECTION WILL PREVAIL TONIGHT
INTO SUNDAY MORNING AT 5 TO 10 KTS...AND THEN VEER MORE INTO A
SOUTHERLY DIRECTION BY AFTERNOON WITH AGAIN SPEEDS OF 10 KTS
OR LESS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMITH
SHORT TERM...07
LONG TERM...ONTON
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
719 PM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 715 PM EDT MON AUG 10 2015
THE CHANCES FOR SHOWERS AND A FEW STORMS WILL DIMINISH THROUGH THE
EVENING AS DRIER AIR FILTERS IN FROM THE NORTH. DRY AND LESS HUMID
WEATHER IS THEN EXPECTED THROUGH MID WEEK. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 60S. HIGH TEMPERATURES ON
TUESDAY WILL REACH INTO THE MID TO UPPER 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
LEAD SHORT WAVE WHICH TRACKED ACROSS THE AREA EARLIER TODAY ALLOWED
FOR INITIAL WEAK LAKE ENHANCED SURFACE TROUGH TO SERVE AS FOCUSING
MECHANISM FOR SCATTERED SHOWERS/ISOLATED STORMS. OVER PAST
HOUR...STARTING TO SEE UPSWING IN CONVECTIVE COVERAGE ALONG THIS
BOUNDARY AS A STRONGER UPSTREAM VORT MAX ACROSS NORTHERN ILLINOIS
CONTINUES TO APPROACH THE AREA. A SECONDARY AREA OF
SCATTERED/NUMEROUS SHOWERS/STORMS HAS DEVELOPED ACROSS FAR
SOUTHERN/AND MAINLY SOUTH OF FORECAST AREA ACROSS CENTRAL INDIANA.
THIS AREA APPEARS BE TIED MORE CLOSELY TO ENHANCED LOW LEVEL THETAE
ADVECTION...WHICH ALSO IS COLOCATED WITH MORE PRONOUNCED INSTABILITY
AXIS WITH LATEST RUC ANALYSIS DEPICTING 100 HPA MLCAPES ON THE ORDER
OF 1000-1500 J/KG. MODEST DEEP LAYER SHEAR AND AND WEAK TO MODERATE
INSTABILITY WILL CONTINUE TO POSE SOME THREAT OF ISOLD STRONG STORMS
WITH GUSTY WINDS AS THE MAIN THREAT. WHILE BRIEF VERY HEAVY RAINFALL
IS POSSIBLE...PROPAGATION VECTORS ARE SLIGHTLY MORE PROGRESSIVE THIS
AFTERNOON IN COMPARISON TO LAST EVENING AND CURRENT THINKING IS THAT
WHILE LOCALIZED PONDING OF WATER/MINOR FLOODING IS POSSIBLE WITH THE
STRONGER STORMS...FLASH FLOODING CONCERNS SHOULD BE MINIMAL.
PRIMARY INSTABILITY AXIS SHOULD BEGIN TO ADVECT ACROSS FAR EASTERN
PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON...BUT WEAK
INSTABILITY WILL REMAIN ACROSS ENTIRE FORECAST AREA AS
AFOREMENTIONED NORTHERN ILLINOIS VORT MAX ALLOWS FOR EROSION OF
RELATIVELY 800-700 HPA LAYER NOTED PER EARLIER AMDAR REGIONAL
SOUNDINGS. THIS SHOULD ALLOW FOR ENOUGH LINGERING INSTABILITY WITH
STRONGER ILLINOIS VORT MAX TO KEEP SOME CHANCE OF ISOLD-SCT
CONVECTION ACROSS THE AREA EARLY THIS EVENING. QUIET CONDITIONS
EXPECTED LATER THIS EVENING INTO THE OVERNIGHT AS SECONDARY SFC
TROUGH USHERS IN COOLER AND DRIER LOW LEVEL AIR. QUIET WEATHER
EXPECTED FOR TUESDAY WITH PERSISTENT MID LEVEL SUBSIDENCE...ALTHOUGH
THE NEXT IN SERIES OF UPPER LEVEL SHORT WAVES IS EXPECTED TO DIG
ACROSS THE GREAT LAKES EARLY TUESDAY...WHICH COULD PROMOTE AN
ISOLATED SHOWER ACROSS SOUTHEAST LOWER MICHIGAN. GIVEN VERY MARGINAL
MOISTURE PROFILES...WILL OMIT FROM FORECAST WITH JUST SLIGHTLY MORE
CONCENTRATED DIURNAL CU ACROSS THE FAR NORTHEAST. DESPITE LOW LEVEL
CAA...GOOD DEAL OF INSOLATION MOST AREAS SHOULD ALLOW FOR HIGHS IN
THE MID TO UPPER 70S.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
HIGH PRESSURE MOVING OUT OF CANADA WILL BRING COOL...DRY
WEATHER FOR THE FIRST PORTION OF THE LONG TERM PERIOD. AS THE
LONGWAVE PATTERN BECOMES MORE ZONAL INTO THE WEEKEND...
TEMPERATURES WILL WARM AND A FEW FRONTAL BOUNDARIES WILL DROP
SOUTHWARD INTO THE GREAT LAKES REGION WITH SHOWERS AND
THUNDERSTORMS POSSIBLE. THE FIRST OF THESE FRONTS WILL DROP
THROUGH ON FRIDAY. A FEW STORMS ARE POSSIBLE ALONG THIS
FRONT...BUT LIMITED INSTABILITY SHOULD LIMIT WIDESPREAD
DEVELOPMENT. THIS FIRST FRONT WILL SETTLE SOUTH OF THE AREA OVER
THE WEEKEND WHICH SHOULD KEEP OUR AREA DRY.
BETTER SHOWERS AND STORM CHANCES RETURN BY THE EARLY PART OF NEXT
WEEK AS MODEL CONSENSUS STALLS A FRONTAL BOUNDARY ACROSS THE
SOUTHERN GREAT LAKES. DEWPOINTS IN THE UPPER 60S TO LOW 70S COUPLED
WITH DAYTIME HEATING SHOULD PROVIDE WEAK TO MODERATE INSTABILITY
EACH DAY...DEPENDING ON THE DEGREE OF HEATING. AT THIS TIME...MID
LEVEL LAPSE RATES AND DEEP LAYER SHEAR LOOK LACKLUSTER WHICH SHOULD
PRECLUDE ANY ORGANIZED SEVERE WEATHER THREAT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 713 PM EDT MON AUG 10 2015
A COUPLE WEAK MID LEVEL DISTURBANCES STILL TO ROTATE THROUGH THE
AREA THIS EVENING. HOWEVER...LOSS OF HEATING AND LOW LEVEL DRIER
AIR MOVING IN SHOULD KEEP MOST AREAS DRY SO WILL NOT INCLUDE ANY
PCPN MENTION AT TERMINALS. SATELLITE AND SFC OBS INDICATE SOME
STRATUS DEVELOPING ALONG LAKE MICHIGAN SHORELINE. THIS MAY ADVECT
SOUTHEAST AND WILL HAVE TO WATCH KSBN. OTHERWISE VFR EXPECTED
THROUGH TUESDAY. NORTHWEST WINDS TUESDAY IN THE 10 TO 15 KNOT
RANGE WITH GUSTS AROUND 20 KNOTS LATE MORNING AND AFTERNOON.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM TUESDAY MORNING THROUGH LATE
TUESDAY NIGHT FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM TUESDAY MORNING THROUGH LATE
TUESDAY NIGHT FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 AM TUESDAY TO 2 AM EDT WEDNESDAY
FOR LMZ043-046.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...MARSILI
LONG TERM...BENTLEY
AVIATION...LASHLEY
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
635 PM CDT MON AUG 10 2015
...UPDATED AVIATION SECTION...
.SYNOPSIS...
ISSUED AT 321 PM CDT MON AUG 10 2015
Light northeasterly surface winds prevailed across western and
central kansas this afternoon. Regional WSR88D as still showing 30
to 40 dbz reflectivity returns across the TX panhandles into
northeast oklahoma associated with the low to mid level baroclinic
zone that since has shifted south. Meanwhile a few surface based
storms have developed in south central and southeast colorado.
widespread 1.3 to 1.5 precipitable water values covered the
forecast area, with the greatest amounts in the south.
&&
.SHORT TERM...(THIS EVENING THROUGH Tuesday)
ISSUED AT 321 PM CDT MON AUG 10 2015
The latest arw and HRRR models were the most aggressive models
with respect to developing convection this afternoon. The 4 km nam
and the nmm were not as aggressive. However the nmm and 4 km HRRR
were also more aggressive with thunderstorms. The severe threat
will be minimal today and tonight with any storms that develop as
continued amplification the the upper ridge weakened the shear
profiles. However very heavy rainfall from efficient warm rain
processes will still be likely for the next day or so, but
steering flow will be weak or non existent. based on the HRRR,
thunderstorm coverage could become scattered by late in the
afternoon. additionally. thunderstorms development across
southeast colorado could spread into far southwest kansas later
this evening aided by weak vorticity advection embedded in the
northwest flow in the models.
.LONG TERM...(Tuesday NIGHT THROUGH Monday)
ISSUED AT 321 PM CDT MON AUG 10 2015
Beyond the short term, increasingly less humid conditions will
develop across central and much of western kansas as surface high
pressure from the northern plains begins to have greater
influence. The general low level moisture transport signal will
remain firmly anchored across the the western counties where the
main if any thunderstorms chances will be located, and the low
level jet may be the best mechanism for get a few thunderstorms
going. Generally high temperatures are forecast around 5 degrees
below climatology through the extended. Lowered dew points should
translate into overnight lows of a few degrees lower as well on
average.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Tuesday EVENING)
ISSUED AT 632 PM CDT MON AUG 10 2015
The threat for thunderstorm activity will mainly be confined to
the vicinity of the GCK terminal through the mid evening hours.
DDC and HYS will be too far removed from the greater concentration
of convection to include in the TAF. A light northeast wind this
evening will give way to a light southeast wind on Tuesday. There
may be some light fog at GCK and/or DDC in the hour or so around
sunrise, however will keep the entire TAF period VFR for now and
re-evaluate this on the next TAF update at 06z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 86 66 89 / 20 30 30 30
GCK 66 85 65 89 / 30 40 40 20
EHA 66 82 66 90 / 70 50 30 20
LBL 68 85 67 89 / 40 40 30 20
HYS 64 86 66 88 / 10 20 30 20
P28 70 86 68 88 / 10 10 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS GOODLAND KS
244 PM MDT SUN AUG 9 2015
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 132 PM MDT SUN AUG 9 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE CONTINUING
TO DOMINATE PATTERN ACROSS SOUTHERN P.LAINS WITH WESTERLY FLOW
ACROSS THE NORTHERN PLAINS. H7 SHORTWAVE TROUGH HAS WEAKENED AND
SHIFTED EAST...WITH ANOTHER H7 SHORTWAVE TROUGH OVER NORTHCENTRAL
COLORADO. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER OUR
CWA...WITH A STATIONARY FRONT EXTENDING FROM NORTHEAST COLORADO
ACROSS NORTHCENTRAL NEBRASKA.
THIS AFTERNOON-TONIGHT...AS FIRST H7 TROUGH HAS WEAKENED AND SHIFTED
EAST SUBSIDENCE HAS SPREAD INTO THE WESTERN PART OF THE FORECAST
AREA WITH LOWER TD VALUES (UPPER 40S/LOWER 50S) ADVECTING INTO THE
WESTERN PARTS OF THE FORECAST AREA. RESULT HAS BEEN CAPE VALUES
DROPPING OFF SHARPLY AND SABLE AIR MOVING BACK OVER THE CWA. SHORT
RANGE GUIDANCE CONTINUES TO KEEP HIGHER TD/CAPE VALUES IN OUR
EASTERN CWA WITH ONLY 100-500 J/KG IN THE WEST THROUGH THE EVENING.
CAPE VALUES AROUND 2000 J/KG ACROSS OUR EASTERN CWA COULD SUPPORT A
FEW MARGINALLY SEVERE THUNDERSTORMS IF SOMETHING WAS TO DEVELOP
ALONG WHAT IS LIKELY A DEVELOPING DRY LINE. NOT A LOT OF CONFIDENCE
AND HI RES GUIDANCE HAS TRENDED AWAY FROM ADDITIONAL DEVELOPMENT IN
OUR EAST. IT APPEARS THAT CHANCES ARE DECREASING FOR MOST OF THE CWA
THIS AFTERNOON. THERE IS THE POSSIBILITY FOR A SHOWER OR
THUNDERSTORM IN THE WESTERN CWA AS ANOTHER SHORTWAVE MOVES IN FROM
THE WEST LATE THIS AFTERNOON THROUGH THIS EVENING...WITH BEST
PRECIP SIGNAL IN THE SW. NOT A LOT OF CONFIDENCE AT THIS POINT IN
COVERAGE...SO I DECIDED TO LIMIT POPS TO THE WEST THIS EVENING
WITH A DOWNWARD TREND THROUGH 06Z.
IT DOES APPEAR THAT HIGHER TD VALUES WILL BEGIN TO RECOVER OVERNIGHT
FROM THE EAST/NORTHEAST WITH SURFACE HIGH PRESSURE/LOW LEVEL
STABILITY SUPPORTING POSSIBLE FOG/STRATUS DEVELOPMENT. BASED ON
SHORT RANGE GUIDANCE AND PERSISTENCE I KEPT HIGHER FOG COVERAGE
(AREAS) LIMITED TO REPUBLICAN RIVER VALLEY IN SW NEBRASKA.
MONDAY...GUIDANCE CONTINUES TO SHOW PRECIP SIGNAL LINGERING ACROSS
THE SW PART OF OUR CWA. ANY SHORTWAVE TROUGHS/VORT MAXES ROTATING
THROUGH PERIPHERY OF THE RIDGE APPEAR TO REMAIN SW OF OUR CWA WITH
VERY LIMITED FORCING. INSTABILITY DOES BEGIN TO INCREASE SO IF
ACTIVITY WAS TO DEVELOP TO THE WEST WE COULD SEE DEVELOPMENT TOWARDS
THE SW PART OF OUR FORECAST AREA. I WASNT CONFIDENT ENOUGH TO
INCREASE POPS DESPITE OVERLAPPING QPF FIELDS IN GUIDANCE...SO I
LIMITED POPS TO 20/30 RANGE MONDAY AFTERNOON. HIGH TEMPS AS WITH THE
LAST FEW DAYS WILL BE HIGHLY DEPENDENT ON MORNING STRATUS CLEARING
WHICH IS CURRENTLY EXPECTED. RESULT SHOULD BE SEASONAL HIGHS IN THE
UPPER 80S/AROUND 90.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM MDT SUN AUG 9 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. SOUTHERN UNITED STATES RIDGE REMAINS CENTERED
OVER CENTRAL/EASTERN TEXAS.
MODELS STARTED OUT FINE AT JET LEVEL. AT MID LEVELS...THE
GFS/CANADIAN WERE INITIALLY DOING BETTER THAN THE REST OF THE OUT
WITH THE NAM/SREF THE WORST OF THE REST OF THE BUNCH. THE SREF
LOOKED LIKE IT WAS THE BEST AT THE SURFACE. IT LOOKED LIKE THE
GFS...CANADIAN AND ECMWF WERE DOING THE BEST ON THE LOW LEVEL
THERMAL FIELD AT THIS TIME.
MONDAY NIGHT...LOW LEVEL UPSLOPE WINDS WILL BE IN PLACE THROUGH THE
NIGHT AS SURFACE RIDGE NOSES DOWN INTO THE AREA. AS SHOWN THE LAST
TWO DAYS...THE SHORTWAVE RIDGE AT 700 MB WILL SLOWLY MOVE TOWARD THE
EAST THROUGH THE NIGHT AS A SHORTWAVE MOVES IN FROM THE WEST. MODELS
HAVE SLOWED THINGS UP A LITTLE...AS HAS THE TREND BEEN THE LAST FEW
DAYS AS WELL. THE GFS IS THE FURTHEST EAST WHICH IS NOT AN UCOMMON
THING WHEN IT COMES TO BREAKING DOWN RIDGES TOO FAST.
SO ONLY PROGRESSED THE POPS SLOWLY TO THE EAST THROUGH THE NIGHT.
THE COMBINATION OF SLOW STORM MOVEMENT...PWS OF 1 TO 1.5 INCHES AND
THE COMMON HEAVY RAIN SCENARIO OF A SHORTWAVE MOVING UP THE WEST
SIDE OF A RIDGE COULD PRODUCE SOME LOCALIZED HEAVY RAINFALL. RAMPED
THE AMOUNTS UP A LITTLE AND INCREASED THE INTENSITY OF THE RAINFALL
AS WELL. THE BEST CHANCE FOR RAINFALL WILL BE IN THE SOUTHWEST THIRD
TO HALF OF THE AREA. THIS PERIOD WILL NEED TO BE WASHED CLOSELY.
TUESDAY/TUESDAY NIGHT...SLOWLY EVOLVING SITUATION THAT BEGINS MONDAY
NIGHT...SLOWLY MOVING CONVECTIVELY INDUCED SYSTEM...CONTINUE THROUGH
THIS ENTIRE PERIOD. MODELS ARE IN GOOD AGREEMENT ABOUT THIS. MORE
THAN LIKELY SOME DEGREE OF CONVECTION WILL CONTINUE FROM THIS
PREVIOUS THROUGH THIS ENTIRE PERIOD. AGAIN SAME HEAVY RAIN SCENARIO
IS IN PLACE AS IN THE PREVIOUS PERIOD AND WILL HAVE TO BE WATCHED
CLOSELY. ALSO THE SOUTHWEST THIRD TO HALF WILL HAVE THE BEST CHANCE
OF RAINFALL...ESPECIALLY DURING THE DAY. THE AREA OF RAINFALL WILL
SLOWLY MOVE TO THE SOUTH AND EAST DURING THE NIGHT.
COMBINATION OF UPSLOPE SURFACE WINDS...LOTS OF CLOUD COVER AND
ONGOING PRECIPITATION...WILL KEEP TEMPERATURES FROM WARMING UP TOO
MUCH...ESPECIALLY IN THE SOUTHWEST HALF. SO LOWERED TEMPERATURES
AROUND 5 DEGREES OR SO. THE COOLEST OUTPUT HAS TEMPERATURES COOLER
THAN WHAT I HAVE THEM.
WEDNESDAY...SLOW MOVING UPPER SYSTEM WILL KEEP RAINFALL AROUND
THROUGH THE MORNING HOURS IN THE SOUTHEAST HALF. IF THERE IS ANY
MORE SLOWLY...THE POPS WILL NEED TO BE RAISED. TEMPERATURES WILL BE
A LITTLE WARMER BUT HOW MUCH WILL DEPEND ON HOW FAST THE SYSTEM AND
ASSOCIATED CLOUDS/RAINFALL MOVE OUT OF THE AREA. AGAIN IF ANY MORE
SLOWING TEMPERATURES WILL NEED TO BE LOWERED.
WEDNESDAY NIGHT THROUGH SUNDAY...NOT TOO MUCH HAS CHANGED FROM WHAT
THE MODELS HAVE BEEN DOING/SHOWING FROM THE LAST FEW DAYS. MODELS
STILL DIFFER ON THE AMPLITUDED AND POSITION OF WHAT IS NOW THE
SOUTHERN RIDGE THAT TRANSITIONS TO A MORE CENTERED WESTERN RIDGE. IN
GENERAL UPPER RIDGE STAYS CENTERED NEAR THE FOUR CORNERS REGION.
SINCE MUCH DOES CHANGE ALOFT...THE SURFACE ALSO DOES NOT CHANGE TOO
MUCH. A SURFACE TROUGH OR LINGERING FRONTAL BOUNDARY STAYS NEAR OR
OVER THE WESTERN PORTION OF THE AREA.
FORECAST WILL HINGE ON SMALL IMPORTANT DETAILS THAT WILL BE HARD TO
PIN DOWN AT THIS TIME SCALE. POSITION OF THE RIDGE SHOULD ALLOW
SUBTROPICAL MOISTURE/WEAK SHORTWAVE TROUGHS TO ROTATE AROUND THE
RIDGE INTO THE AREA. ALSO THE SURFACE BOUNDARY SHOULD HELP SET
THUNDERSTORMS OFF. THERE WILL NOT BE HIGH PRECIPITATION CHANCES BUT
HARD TO SAY THERE WILL NOT BE ANYTHING AT ALL. PER THE OVERNIGHT
DISCUSSION/REASONING...THE WESTERN PORTION OF THE AREA WILL PROBABLY
SEE THE BEST CHANCE DUE TO THE PROXIMITY OF THE SURFACE BOUNDARY.
THE NEW CRH_INIT IS IN GOOD AGREEMENT WITH THE ABOVE MENTIONED
SCENARIO/REASONING...SO ONCE AGAIN MADE NO CHANGES TO IT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1124 AM MDT SUN AUG 9 2015
ISOLATED TO SCATTERED SHOWER ACTIVITY IS CURRENTLY MOVING WITHIN
THE VICINITY OF BOTH KGLD AND KMCK TERMINALS. UPPER LEVEL SYSTEM
RESPONSIBLE FOR THIS ACTIVITY WILL CONTINUE TO SHIFT EAST THROUGH
THIS AFTERNOON AS INSTABILITY INCREASES...SO A FEW THUNDERSTORMS
COULD DEVELOP THIS AFTERNOON/EVENING. AT THIS TIME IT APPEARS MOST
THUNDERSTORM ACTIVITY SHOULD BE EAST/SOUTHEAST AND COVERAGE AND
POTENTIAL IMPACT AT EITHER TERMINAL IS IN QUESTION. DECIDED TO
KEEP VCSH MENTION AND HOLD OFF ON THUNDERSTORM MENTION DURING THIS
UPDATE.
SURFACE HIGH PRESSURE WILL CONTINUE TO SPREAD SOUTH WITH
LIGHT WINDS AT BOTH TERMINALS THROUGH THE TAF PERIOD. FOG/STRATUS
IS EXPECTED TO REDEVELOP 10-12Z AT KMCK AND LAST THROUGH MID
MORNING MONDAY. WITH AMPLE MOISTURE IN PLACE AND VERY STABLE LOW
LEVELS FOG/STRATUS COULD SPREAD AS FAR WEST AS KGLD. CONFIDENCE IS
HIGHER AT KMCK WHERE IFR CONDITIONS APPEAR LIKELY AND BRIEF LIFR
CONDITIONS WILL BE POSSIBLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
313 PM CDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
CURRENT SURFACE ANALYSIS SHOWS THE MAIN SYNOPTIC BOUNDARY EXTENDING
SOUTHWARD FROM KANSAS CITY TO WICHITA, WHICH IS FORECAST TO SAG
SOUTHWARD THROUGH THE AFTERNOON AND EVENING HOURS. ALTHOUGH THE MORE
EVIDENT THERMAL GRADIENT HAS PUSHED INTO SOUTHEAST KS AND HAS BEEN
RESPONSIBLE FOR SCATTERED SHOWERS AND ISOLATED THUNDER THIS MORNING.
THIS HAS KEPT THE CLOUD COVER AROUND MUCH LONGER THAN FORECASTED,
BUT AN AREA OF CLEAR SKIES IS WORKING EASTWARD ACROSS NORTHEAST KS,
WHICH MAY ALLOW TEMPERATURES TO WARM INTO THE LOWER TO MIDDLE 90S.
HIGH MOISTURE POOLING IN THE BOUNDARY LAYER HAS KEPT DEW POINTS IN
THE MID TO UPPER 70S. EXPECT THAT HEAT INDICES WILL BE IN THE LOWER
100S THROUGH EARLY EVENING FOR LOCATIONS ALONG AND SOUTH OF I-70.
THERE WILL BE A FEW THINGS OF CONCERN LATER THIS EVENING AND
OVERNIGHT. THE MODELS SHOW A SHORTWAVE TROUGH ON THE NORTHERN
PERIPHERY OF THE UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS WILL
TRACK ACROSS SOUTHERN KS TONIGHT. THIS MAY SUPPORT THE DEVELOPMENT
OF AN MCS OR MULTICELL CLUSTER IN WESTERN OR CENTRAL KS THIS EVENING
NORTH OF THE SURFACE BOUNDARY. SURFACE BASED CONVECTION HAS ALREADY
BEGAN IN NORTHWEST KS. AS THAT BOUNDARY DRIFTS SOUTHWARD THE TRACK
OF THE MCS MAY ALSO DO THE SAME AS DEPICTED BY THE NAM. THE PAST FEW
RUNS OF THE HRRR HAVE BEEN CLIPPING THE SOUTHERN FORECAST AREA WITH
THIS MCS. INSTABILITY HAS BEEN SOMEWHAT LIMITED TODAY ACROSS
SOUTHERN KS AS OPPOSED TO NORTHERN KS, WHICH HAS SET UP A DECENT
GRADIENT. THEREFORE IT IS UNCERTAIN HOW SEVERE THESE STORMS WILL BE
THIS EVENING, BUT THE TRACK MAY BE MORE FOCUSED ALONG THIS
INSTABILITY GRADIENT INSTEAD. AS FOR NOW THE BEST CHANCES FOR PRECIP
WILL BE SOUTH OF I-70 LATE THIS EVENING AND EARLY MORNING WITH THE
SLIGHT CHANCE FOR A STRONG STORM. WITH PLENTY OF MOISTURE AROUND AND
LIGHT LOW LEVEL WINDS ASSOCIATED WITH THE BOUNDARY THERE IS A CHANCE
FOR HAZE AND OR FOG EARLY TOMORROW MORNING. THERE ARE SOME
INDICATIONS THAT THE SKIES COULD CLEAR LATE TONIGHT AND ALLOW FOR
BOUNDARY LAYER COOLING. A FEW OF THE MODELS ARE HINTING AT A
NORTHERN SHORTWAVE THAT WILL TRACK OVER SD AND NE OVERNIGHT. THIS
MAY ALSO SUPPORT A SOUTHEASTWARD MOVING MCS THAT COULD REACH
NORTHERN KS AROUND SUNRISE. IN FACT, THE INSTABILITY IS ALREADY
DECENT IN THAT AREA, WHICH WOULD SUPPORT THIS SCENARIO BETTER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
THERE IS NOT MUCH CHANGE IN THE FORECAST FOR MONDAY NIGHT THROUGH
SUNDAY AS MODELS CONTINUE TO SHOW AN UPPER LEVEL RIDGE AMPLIFYING
TO THE WEST AND SOUTHWEST CAUSING NORTHWEST FLOW TO SET UP OVER
THE FORECAST AREA. ABOUT THE ONLY THING OF CONCERN IS THE
POSSIBILITY FOR SOME ELEVATED PRECIP ACROSS NORTH CENTRAL KS LATE
TUESDAY NIGHT AND WEDNESDAY MORNING. THERE ARE INDICATIONS THAT
CONVECTION IN THE MOUNTAINS COULD GENERATE A VORT MAX AND THEN
DRIFT EAST AND SOUTH THROUGH CENTRAL KS. FOR NOW MOST GUIDANCE
KEEPS ANY PRECIP JUST TO THE WEST OF THE FORECAST AREA. THIS SEEMS
TO MAKE SINCE AS MODELS BRING THE CENTER OF THE 850 MB RIDGE OVER
THE FORECAST AREA BY 12Z WED WITH NO REAL RETURN FLOW AND THE
DEEPER MOISTURE AXIS REMAINING OVER WESTERN KS. SO THE FORECAST
REMAINS DRY THROUGH NEXT WEEKEND WITH NO OBVIOUS SIGNS OF FORCING
IMPACTING THE FORECAST AREA AFTER WEDNESDAY.
TEMPS ARE EXPECTED TO BE COOLER THAN NORMAL FOR TUESDAY THROUGH
THURSDAY. MODELS ARE IN AGREEMENT THAT A MODIFIED HIGH PRESSURE
SYSTEM WILL BUILD INTO THE AREA WITH SOME WEAK COLD AIR ADVECTION
AND DRYER AIR. BECAUSE OF THIS LOWS SHOULD BE IN THE LOWER AND MID
60S WITH HIGHS IN THE 80S. BY FRIDAY AND INTO THE WEEKEND, THE
UPPER RIDGE IS EXPECTED TO PROPAGATE EAST INTO THE PLAINS AS AN
UPPER TROUGH OVER THE PACIFIC NORTHWEST COAST MOVES INLAND. THIS
SHOULD SHIFT THE THERMAL RIDGE OUT INTO THE PLAINS WITH HIGHS
WARMING BACK INTO THE LOWER AND MID 90S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1225 PM CDT SUN AUG 9 2015
THERE IS A CHANCE FOR SHOWERS AND STORMS LATE THIS AFTERNOON AND
EARLY EVENING. HEAVY RAIN COULD REDUCE VISIBILITIES FOR A BRIEF
PERIOD OTHERWISE VFR. WITH LIGHT WIND AND CLEARING SKIES FOG/HAZE
WILL BE POSSIBLE TOMORROW MORNING AROUND SUNRISE. NOT SURE HOW LOW
THE VISIBILITIES WILL GO BUT WENT WITH MVFR FOR NOW. THERE IS A
CHANCE THAT MOISTURE MIXES INTO A MVFR CLOUD DECK AT THE END OF
THE TAF PERIOD.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SANDERS
LONG TERM...WOLTERS
AVIATION...SANDERS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
132 PM MDT SUN AUG 9 2015
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 132 PM MDT SUN AUG 9 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE CONTINUING
TO DOMINATE PATTERN ACROSS SOUTHERN P.LAINS WITH WESTERLY FLOW
ACROSS THE NORTHERN PLAINS. H7 SHORTWAVE TROUGH HAS WEAKENED AND
SHIFTED EAST...WITH ANOTHER H7 SHORTWAVE TROUGH OVER NORTHCENTRAL
COLORADO. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER OUR
CWA...WITH A STATIONARY FRONT EXTENDING FROM NORTHEAST COLORADO
ACROSS NORTHCENTRAL NEBRASKA.
THIS AFTERNOON-TONIGHT...AS FIRST H7 TROUGH HAS WEAKENED AND SHIFTED
EAST SUBSIDENCE HAS SPREAD INTO THE WESTERN PART OF THE FORECAST
AREA WITH LOWER TD VALUES (UPPER 40S/LOWER 50S) ADVECTING INTO THE
WESTERN PARTS OF THE FORECAST AREA. RESULT HAS BEEN CAPE VALUES
DROPPING OFF SHARPLY AND SABLE AIR MOVING BACK OVER THE CWA. SHORT
RANGE GUIDANCE CONTINUES TO KEEP HIGHER TD/CAPE VALUES IN OUR
EASTERN CWA WITH ONLY 100-500 J/KG IN THE WEST THROUGH THE EVENING.
CAPE VALUES AROUND 2000 J/KG ACROSS OUR EASTERN CWA COULD SUPPORT A
FEW MARGINALLY SEVERE THUNDERSTORMS IF SOMETHING WAS TO DEVELOP
ALONG WHAT IS LIKELY A DEVELOPING DRY LINE. NOT A LOT OF CONFIDENCE
AND HI RES GUIDANCE HAS TRENDED AWAY FROM ADDITIONAL DEVELOPMENT IN
OUR EAST. IT APPEARS THAT CHANCES ARE DECREASING FOR MOST OF THE CWA
THIS AFTERNOON. THERE IS THE POSSIBILITY FOR A SHOWER OR
THUNDERSTORM IN THE WESTERN CWA AS ANOTHER SHORTWAVE MOVES IN FROM
THE WEST LATE THIS AFTERNOON THROUGH THIS EVENING...WITH BEST
PRECIP SIGNAL IN THE SW. NOT A LOT OF CONFIDENCE AT THIS POINT IN
COVERAGE...SO I DECIDED TO LIMIT POPS TO THE WEST THIS EVENING
WITH A DOWNWARD TREND THROUGH 06Z.
IT DOES APPEAR THAT HIGHER TD VALUES WILL BEGIN TO RECOVER OVERNIGHT
FROM THE EAST/NORTHEAST WITH SURFACE HIGH PRESSURE/LOW LEVEL
STABILITY SUPPORTING POSSIBLE FOG/STRATUS DEVELOPMENT. BASED ON
SHORT RANGE GUIDANCE AND PERSISTENCE I KEPT HIGHER FOG COVERAGE
(AREAS) LIMITED TO REPUBLICAN RIVER VALLEY IN SW NEBRASKA.
MONDAY...GUIDANCE CONTINUES TO SHOW PRECIP SIGNAL LINGERING ACROSS
THE SW PART OF OUR CWA. ANY SHORTWAVE TROUGHS/VORT MAXES ROTATING
THROUGH PERIPHERY OF THE RIDGE APPEAR TO REMAIN SW OF OUR CWA WITH
VERY LIMITED FORCING. INSTABILITY DOES BEGIN TO INCREASE SO IF
ACTIVITY WAS TO DEVELOP TO THE WEST WE COULD SEE DEVELOPMENT TOWARDS
THE SW PART OF OUR FORECAST AREA. I WASNT CONFIDENT ENOUGH TO
INCREASE POPS DESPITE OVERLAPPING QPF FIELDS IN GUIDANCE...SO I
LIMITED POPS TO 20/30 RANGE MONDAY AFTERNOON. HIGH TEMPS AS WITH THE
LAST FEW DAYS WILL BE HIGHLY DEPENDENT ON MORNING STRATUS CLEARING
WHICH IS CURRENTLY EXPECTED. RESULT SHOULD BE SEASONAL HIGHS IN THE
UPPER 80S/AROUND 90.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 248 AM MDT SUN AUG 9 2015
AN UPPER LEVEL RIDGE WILL CONTINUE TO BE IN PLACE OVER THE TRI STATE
AREA TO START OFF THE LONG TERM PERIOD WEDNESDAY. THE CENTRAL AREA
OF HIGH PRESSURE WILL REMAIN OVER THE ROCKY MOUNTAIN RANGE AND THE
CENTRAL PLAINS WEDNESDAY. WITH THE PRESENCE OF THE UPPER
RIDGE...JET AREAS AND POCKETS OF VORTICITY WILL REMAIN WELL AWAY
FROM THE TRI STATE AREA...WHICH WILL BRING UPPER STABILITY FOR THE
REST OF THE FORECAST PERIOD.
AT THE SURFACE...MAINLY SOUTHERLY FLOW WILL ADVECT WARM MOIST AIR
INTO THE HIGH PLAINS WITH A BIT OF AN UPSLOPE COMPONENT AS WINDS ARE
SOMEWHAT SOUTHEASTERLY. GFS/ECMWF MODEL SOUNDINGS SHOW PRECIPITABLE
WATER VALUES BETWEEN 1 AND 1.5 INCHES OVER THE TRI STATE AREA WITH
SOME CAPE IN THE PROFILE THAT WOULD BE CONDUCIVE TO STEADY RAINFALL
PRODUCTION. WITH CAP VIA MODEL SOUNDINGS APPEARING CLOSE TO BEING
ABLE TO BREAK DUE TO SURFACE HEATING DESPITE A LACK OF STRONG
SURFACE AND UPPER LEVEL FORCING...CHANCES FOR SHOWERS AND
THUNDERSTORMS ARE POSSIBLE WEDNESDAY EVENING MAINLY FOR SOUTH OF
INTERSTATE 70 ALONG THE SURFACE TROUGH AND A WEAK DRY LINE
FEATURE.
CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS ARE ALSO POSSIBLE
HEADING INTO THURSDAY...FRIDAY AND SATURDAY WITH A WEAK QUASI
STATIONARY SURFACE DEFORMATION ZONE INDICATED BY THE GFS/ECMWF
SURFACE FORECASTS. CURRENTLY THINKING THE BEST CHANCE FOR STORMS
WILL BE IN EASTERN COLORADO ALONG A SURFACE CONFLUENT LINE THAT
REMAINS IN PLACE DURING THE LATER PART OF THE FORECAST PERIOD.
HIGH TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO BE ABOUT NORMAL
IN THE UPPER 80S TO LOWER 90S...AND LOW TEMPERATURES IN THE LOW TO
MID 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1124 AM MDT SUN AUG 9 2015
ISOLATED TO SCATTERED SHOWER ACTIVITY IS CURRENTLY MOVING WITHIN
THE VICINITY OF BOTH KGLD AND KMCK TERMINALS. UPPER LEVEL SYSTEM
RESPONSIBLE FOR THIS ACTIVITY WILL CONTINUE TO SHIFT EAST THROUGH
THIS AFTERNOON AS INSTABILITY INCREASES...SO A FEW THUNDERSTORMS
COULD DEVELOP THIS AFTERNOON/EVENING. AT THIS TIME IT APPEARS MOST
THUNDERSTORM ACTIVITY SHOULD BE EAST/SOUTHEAST AND COVERAGE AND
POTENTIAL IMPACT AT EITHER TERMINAL IS IN QUESTION. DECIDED TO
KEEP VCSH MENTION AND HOLD OFF ON THUNDERSTORM MENTION DURING THIS
UPDATE.
SURFACE HIGH PRESSURE WILL CONTINUE TO SPREAD SOUTH WITH
LIGHT WINDS AT BOTH TERMINALS THROUGH THE TAF PERIOD. FOG/STRATUS
IS EXPECTED TO REDEVELOP 10-12Z AT KMCK AND LAST THROUGH MID
MORNING MONDAY. WITH AMPLE MOISTURE IN PLACE AND VERY STABLE LOW
LEVELS FOG/STRATUS COULD SPREAD AS FAR WEST AS KGLD. CONFIDENCE IS
HIGHER AT KMCK WHERE IFR CONDITIONS APPEAR LIKELY AND BRIEF LIFR
CONDITIONS WILL BE POSSIBLE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...DR
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
604 AM CDT SUN AUG 9 2015
...Updated aviation discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CDT SUN AUG 9 2015
Upper level ridging will migrate westward from the southern
plains into the southern and central Rockies through mid week. A
shortwave trough will progress across the northern plains over the
upper level ridge today and tonight, helping to push a cold front
through the remainder of southwestern Kansas. There will be a
good chance of thunderstorms as the cold front passes, with the
best chances being this afternoon and evening ahead of the front
or south of a line from Liberal to Bucklin to Stafford where
temperatures will warm into the 90s. Marginally severe hail and
wind gusts to 60 mph are possible with these storms. However,
despite the slightly cooler temperatures north of the front, low
level moisture will be very rich with dewpoints near 70F.
Therefore, surface based CAPE values will be even higher in this
area. The greatest shear will also be north of the front given
the stronger upper level winds and easterly low level winds. Thus,
storms that develop from Garden City to Dodge City northeastward
to Ness City, Jetmore and Rush Center this afternoon will be
capable of large hail.
.LONG TERM...(Monday THROUGH Saturday)
ISSUED AT 330 AM CDT SUN AUG 9 2015
Thunderstorms will end late Sunday night in south central Kansas.
Surface high pressure will edge into western Kansas Monday with
north winds. Thunderstorm activity will likely be suppressed into
the southern plains on Monday. By Monday night into Wednesday,
there will be chances for thunderstorms from Dodge City west to
the Colorado state line despite the proximity of upper level
ridging since post frontal, moist upslope flow is expected to
persist for several days. The beat chance for thunderstorms will
be over far southwest Kansas where the best moisture and upslope
flow will be, with western high plains convection moving into
this area. Severe weather is unlikely through this week as the
mid to upper level winds will be very weak; but localized heavy
rain is a possibility in far western Kansas. Temperatures will be
cooler with highs mainly in the upper 80s Monday, mid 80s Tuesday
and Wednesday and upper 80s on Thursday and Friday. Drier weather
is likely starting Thursday as the upper level ridge becomes even
more amplified, with a less favorable northerly mid level flow
regime across the high plains. Temperatures should warm into the
lower 90s by the weekend.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Monday MORNING)
ISSUED AT 602 AM CDT SUN AUG 9 2015
BUFR soundings, RAP and HRRR indicating VFR conditions can be
expected today at all three taf sites. There will be a chance for
some scattered thunderstorms later today, especially in the DDC
area. At this time the probability of these storm impacting either
GCK or HYS is low so am leaning towards not inserting a mention of
thunderstorms into these taf sites just yet. May insert a prob30
at GCK. At DDC will include a tempo group of -TSRA in the tafs
between 21z Sunday and 00z Monday based on location of the surface
boundary and late day instability. The prevailing wind today will
be northeast at 10 knots or less.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 91 69 89 66 / 50 40 10 20
GCK 89 68 86 66 / 30 20 10 30
EHA 92 67 86 66 / 40 30 30 50
LBL 93 70 89 68 / 50 40 20 40
HYS 90 69 87 65 / 30 30 10 10
P28 98 73 91 70 / 40 60 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GOODLAND KS
250 AM MDT SUN AUG 9 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERAL WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM
FRONT IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE
WEAK SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE
FORECAST AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY
LINGER THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE
EVENING HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND
TO SUPPORT POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(WEDNESDAY THROUGH SATURDAY)
ISSUED AT 248 AM MDT SUN AUG 9 2015
AN UPPER LEVEL RIDGE WILL CONTINUE TO BE IN PLACE OVER THE TRI STATE
AREA TO START OFF THE LONG TERM PERIOD WEDNESDAY. THE CENTRAL AREA
OF HIGH PRESSURE WILL REMAIN OVER THE ROCKY MOUNTAIN RANGE AND THE
CENTRAL PLAINS WEDNESDAY. WITH THE PRESENCE OF THE UPPER
RIDGE...JET AREAS AND POCKETS OF VORTICITY WILL REMAIN WELL AWAY
FROM THE TRI STATE AREA...WHICH WILL BRING UPPER STABILITY FOR THE
REST OF THE FORECAST PERIOD.
AT THE SURFACE...MAINLY SOUTHERLY FLOW WILL ADVECT WARM MOIST AIR
INTO THE HIGH PLAINS WITH A BIT OF AN UPSLOPE COMPONENT AS WINDS ARE
SOMEWHAT SOUTHEASTERLY. GFS/ECMWF MODEL SOUNDINGS SHOW PRECIPITABLE
WATER VALUES BETWEEN 1 AND 1.5 INCHES OVER THE TRI STATE AREA WITH
SOME CAPE IN THE PROFILE THAT WOULD BE CONDUCIVE TO STEADY RAINFALL
PRODUCTION. WITH CAP VIA MODEL SOUNDINGS APPEARING CLOSE TO BEING
ABLE TO BREAK DUE TO SURFACE HEATING DESPITE A LACK OF STRONG
SURFACE AND UPPER LEVEL FORCING...CHANCES FOR SHOWERS AND
THUNDERSTORMS ARE POSSIBLE WEDNESDAY EVENING MAINLY FOR SOUTH OF
INTERSTATE 70 ALONG THE SURFACE TROUGH AND A WEAK DRY LINE
FEATURE.
CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS ARE ALSO POSSIBLE
HEADING INTO THURSDAY...FRIDAY AND SATURDAY WITH A WEAK QUASI
STATIONARY SURFACE DEFORMATION ZONE INDICATED BY THE GFS/ECMWF
SURFACE FORECASTS. CURRENTLY THINKING THE BEST CHANCE FOR STORMS
WILL BE IN EASTERN COLORADO ALONG A SURFACE CONFLUENT LINE THAT
REMAINS IN PLACE DURING THE LATER PART OF THE FORECAST PERIOD.
HIGH TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO BE ABOUT NORMAL
IN THE UPPER 80S TO LOWER 90S...AND LOW TEMPERATURES IN THE LOW TO
MID 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1132 PM MDT SAT AUG 8 2015
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE BOUNDARY
LAYER MOISTURE INCREASES TO THE POINT THAT STRATUS AND FOG
DEVELOPS AT KGLD AND KMCK. MVFR CONDITIONS CAN BE EXPECTED AT
BOTH SITES. VFR CONDITIONS RETURN BY LATE SUNDAY MORNING AND
CONTINUE THROUGH THE AFTERNOON AND EVENING. THERE IS ONLY A SLIGHT
CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON AND EVENING WITH BETTER
CHANCES WELL TO THE SOUTH SO WILL LEAVE OUT OF THE TAFS FOR NOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...MK
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1141 PM MDT SAT AUG 8 2015
.SHORT TERM...(THIS AFTERNOON THROUGH SUNDAY)
ISSUED AT 229 PM MDT SAT AUG 8 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOWS 595 DM RIDGE
ACROSS SOUTHERN PLAINS WITH PLUME OF PACIFIC MOISTURE STREAMING INTO
THE CENTRAL ROCKIES AND ACROSS OUR CWA. SEVERAL WEAK
RIPPLES/SHORTWAVE TROUGHS WITHIN THE H5/H7 SW FLOW ARE UPSTREAM OF
THE REGION WITH SOME ENHANCEMENT ACROSS THE HIGHER TERRAIN IN THE
CENTRAL AND SOUTHERN ROCKIES. AT THE SURFACE LOW PRESSURE EXTENDS
ACROSS EASTERN COLORADO AND SOUTHWEST KANSAS. STATIONARY/WARM
FRONT IS CURRENTLY JUST OVER THE SOUTHEAST PORTIONS OF OUR CWA.
THIS AFTERNOON-TONIGHT...BAROCLINIC ZONE EXTENDING ACROSS SE CWA AND
ACROSS EASTERN COLORADO WILL ACT AS FOCUS FOR INITIATION NEAR OUR CWA
AS HEIGHT FALLS AND INCREASING ISENTROPIC ASCENT MOVES SOUTH OF
INTERSTATE 70. STRONGEST PRECIP SIGNAL IS ALONG STATIONARY FRONT IN
THE SOUTH...ESPECIALLY BY ARW/HRRR. RAP ANALYSIS SHOWS CAPE VALUES
ALREADY AROUND 4000 J/KG IN THE SOUTHEAST...WITH EFFECTIVE BULK
SHEER VALUES IN EXCESS OF 40KT. WHILE THERE IS SOME LOW LEVEL
VEERING...OVERALL SEVERE INDICES FAVOR DAMAGING WINDS AND LARGE
HAIL WITH ON A SMALL THREAT FOR TORNADOS WITHIN PROXIMITY TO MAIN
TROUGH AXIS. VERY MOIST AIR MASS...THE POSSIBILITY FOR BACKBUILDING
ALONG FRONTAL ZONE...AND STORM MOTIONS GENERALLY LESS THAN 20KT WILL
TEND TO SUPPORT POTENTIAL FOR LOCALIZED FLASH FLOODING. HI RES
GUIDANCE IS INDICATING POTENTIAL FOR THUNDERSTORMS TO FORM INTO ONE
OR SEVERAL SMALL MCS CLUSTERS ACROSS THE SOUTHERN PART OF THE
FORECAST AREA. EARLIER GUIDANCE WAS SHOWING THIS SPREADING AS FAR
NORTH AS THE I-70 CORRIDOR.
WITH LINGERING WAA ACROSS THE SE CWA...ALONG WITH SEVERAL MORE
WEAK SHORTWAVES PASSING THROUGH THE REGION...SE PORTIONS OF THE
FORECAST AREA COULD CONTINUE TO SEE SHOWER/THUNDERSTORM ACTIVITY
LINGER THROUGH SUNDAY MORNING. TREND WILL BE FOR DECREASING
INSTABILITY...SO SEVERE THREAT SHOULD BE LIMITED TO JUST THE
EVENING HOURS. VERY MOIST AIR MASS AND LIGHT WINDS WILL ALSO TEND
TO SUPPORT POTENTIAL FOR FOG/STRATUS TO REDEVELOP BY SUNRISE.
SUNDAY...WITH WEAK FORCING AND LINGERING FRONT IN OUR SE...THERE
WILL BE THE POTENTIAL FOR SHOWERS/THUNDERSTORMS THROUGH MIDDAY. NAM
SHOWS INCREASING FORCING BY LATE MORNING EARLY AFTERNOON AS A
STRONGER TROUGH DIGS INTO THE NORTHERN PLAINS. OTHER GUIDANCE IS NOT
QUITE AS FAR SOUTH...PRIMARILY FAVORS THE SOUTHER PARTS OF OUR CWA
FOR BEST THUNDERSTORM CHANCES. THERE SHOULD BE ENOUGH
INSTABILITY/SHEER IN THE AFTERNOON TO SUPPORT AT LEAST A FEW MORE
ORGANIZED THUNDERSTORMS. LOW CONFIDENCE IN HI TEMP FORECAST AS (LIKE
TODAY) TEMPS WILL BE HIGHLY DEPENDENT ON STRATUS CLEARING AND TIMING
OF THUNDERSTORM ACTIVITY. THE AIR MASS ADVERTISED OVER THE CWA WITH
AVERAGE MIXING WOULD SUPPORT SEASONAL HIGHS IN THE UPPER 80S/LOWER
90S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM MDT SAT AUG 8 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. THIS FLOW BECOMES MORE OF A SPLIT WITH THE
TROUGHS OVER THE WESTERN AND EASTERN PORTIONS OF THE COUNTRY. OLD
CUTOFF LOW IS NOW BEING EJECTED INTO THE NORTH CENTRAL PORTION OF
THE COUNTRY. MONSOONAL MOISTURE CONTINUES TO PULLED UP INTO THE
REGION WITH EMBEDDED SHORTWAVE TROUGHS WITHIN THIS FLOW. AIR MASS
REMAINS MOIST THROUGH A SIGNIFICANT DEPTH.
AT JET LEVEL...THE GFS FOLLOWED BY THE NAM/CANADIAN WERE INITIALLY
DOING THE BEST HERE. AT MID LEVELS...MODELS WERE CLOSE WITH THE
GFS/CANADIAN/UKMET DOING SLIGHTLY BETTER. THE SREF AND NAM WERE
DOING THE BEST ON THE SURFACE WIND AND PRESSURE FIELD. MODELS WERE
HAVING A LITTLE TROUBLE ON THE LOW LEVEL THERMAL FIELD...THEY TENDED
TO BE TOO COOL. OVERALL WOULD HAVE TO GIVE A SLIGHT EDGE TO THE NAM
AND SREF.
SUNDAY NIGHT...LOOKS LIKE SOME WEAK BOUNDARY SAGS SOUTH ACROSS THE
AREA. MODELS ARE A LITTLE FASTER IN TAKING THE INITIAL SHORTWAVE
THROUGH ALTHOUGH THERE IS NOT VERY GOOD AGREEMENT IN THAT. MODELS
WANT TO BRING ANOTHER SHORTWAVE IN NORTHWEST FLOW DURING THE
OVERNIGHT HOURS WITH ALSO NOT A LOT OF AGREEMENT. RIGHT REAR
QUADRANT AFFECTS THE FAR NORTHERN PORTION OF THE AREA. WILL KEEP THE
SLIGHT TO LOW CHANCE POPS WITH A GRADUAL DECREASE THROUGH THE NIGHT.
LOOKS LIKE THERE WILL BE MAINLY STRATUS WITH NOT AS GOOD OF A CHANCE
OF FOG.
MONDAY/MONDAY NIGHT...RIDGE BEGINS TO BUILD INTO THE AREA WITH THE
UPPER JET BEING PUSHED FURTHER NORTH AWAY FROM THE AREA. AREA IS IN
POST FRONTAL UPSLOPE REGIME. RIDGING ALOFT LOOKS A LITTLE STRONGER
AND FURTHER WEST DURING THE DAY THAN WAS SHOWN YESTERDAY SO WILL
PUSH THE POPS FURTHER WEST. WILL HAVE SOME CLOUD COVER TO START THE
DAY WITH A COOLER AIR MASS AND UPSLOPE WINDS PRESENT THROUGH THE DAY
SO WILL DEFINITELY BE COOLER.
700 MB RIDGE MOVES A LITTLE TO THE EAST DURING THE NIGHT WITH
INCREASING LIFT COMING IN FROM THE SOUTHWEST. SO POPS SHOULD STAY
CONFINED TO THE SOUTHWEST HALF OF THE AREA WITH A GRADUAL INCREASE
THROUGH WITH STORMS NOT MOVING VERY FAST. THAT COMBINED WITH HIGH
PWS WILL SET THE STAGE MODERATE TO LOCALLY HEAVY RAINFALL.
TUESDAY...ABOVE MENTIONED SHORTWAVE RIDGE AND TROUGH CONTINUE TO
MOVE SLOWLY EAST THROUGH THE DAY. MOIST AIR MASS REMAIN IN PLACE
WITH INCREASING LIFT. IT IS POSSIBLE THAT THERE COULD BE SOME
PRECIPITATION AT THE BEGINNING AND THEN IT SHOULD GRADUALLY
INCREASE IN COVERAGE AND INTENSITY. SO HAVE THE HIGHER POPS IN THE
AFTERNOON.
EASTERLY WINDS...CLOUD COVER AND DEVELOPING PRECIPITATION SHOULD
KEEP TEMPERATURES SHOULD KEEP TEMPERATURES FROM WARMING VERY MUCH.
TUESDAY NIGHT THROUGH SATURDAY...DETERMINISTIC AND ENSEMBLE OUTPUT
IN BETTER AGREEMENT IN REGARDS TO THE EVOLUTION OF THE UPPER
PATTERN. ESSENTIALLY MODELS BUILD THE RIDGE...NOW CENTERED TO OUR
SOUTH...FURTHER TO THE WEST AND NORTH. THE DIFFERENCES INCREASE A
LITTLE TOWARD THE END OF THE PERIOD BUT NOT AS BAD AS YESTERDAY. THE
CENTER OF THE RIDGE WILL BE NEAR THE FOUR CORNERS REGION LEAVING A
WEAKER NORTHERLY FLOW OVER THE AREA.
IN THIS PATTERN WOULD ANTICIPATE THE SUBTROPICAL MOISTURE TO BE ABLE
TO ROTATE AROUND THE RIDGE WITH WEAK/SUBTLE SHORTWAVES ROTATING
AROUND IT. WPC PROGS SHOW A PERSISTENT FRONTAL BOUNDARY ALONG OR
OVER THE WESTERN PORTION OF THE AREA UNTIL THE LAST DAY WHEN A DRY
LINE/SURFACE TROUGH SETS UP IN THE SAME PLACE. WITH VERY SUBTLE
FEATURES...I CANNOT RULE OUT CHANCES FOR THUNDERSTORMS ALMOST EVERY
PERIOD.
SO ANY SLIGHT CHANCE TO LOW CHANCE POPS TO DRY CONDITIONS DO NOT
SEEM UNREASONABLE DEPENDING ON HOW THE DETAILS WORK OUT. SO ONCE
AGAIN DID NOT MAKE ANY CHANGES TO WHAT THE CRH_INIT GAVE ME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1132 PM MDT SAT AUG 8 2015
VFR CONDITIONS WILL CONTINUE FOR A FEW MORE HOURS BEFORE BOUNDARY
LAYER MOISTURE INCREASES TO THE POINT THAT STRATUS AND FOG
DEVELOPS AT KGLD AND KMCK. MVFR CONDTIONS CAN BE EXPECTED AT
BOTH SITES. VFR CONDITIONS RETURN BY LATE SUNDAY MORNING AND
CONTINUE THROUGH THE AFTERNOON AND EVENING. THERE IS ONLY A SLIGHT
CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON AND EVENING WITH BETTER
CHANCES WELL TO THE SOUTH SO WILL LEAVE OUT OF THE TAFS FOR NOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS JACKSON KY
952 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 952 PM EDT MON AUG 10 2015
A BROKEN LINE OF SHOWERS/THUNDERSTORMS WAS DROPPING SOUTH THROUGH
THE REGION. THEY WERE SHOWING AN OVERALL SLOW WEAKENING TREND.
HOWEVER...ADDITIONAL SHOWERS WERE STARTING TO DEVELOP AHEAD OF
THE LINE. FORECAST GRIDS HAVE BEEN UPDATED TO TIME THE LINE SOUTH
INTO THE FORECAST AREA.
UPDATE ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 915 PM EDT MON AUG 10 2015
CONDITIONS ACROSS THE REGION WERE VFR AT THE START OF THE
PERIOD. HOWEVER...A BROKEN LINE OF THUNDERSTORMS WAS JUST NORTH
OF THE JKL FORECAST AREA. IT WAS ASSOCIATED WITH A COLD FRONT
WHICH WILL DROP SOUTH THROUGH THE REGION TONIGHT...BRINGING
SCATTERED SHOWERS AND THUNDERSTORMS AND LOCALIZED IFR. MOST OF
THE PRECIPITATION WILL DIMINISH OR MOVE OUT TO THE SOUTHEAST
BEFORE DAWN. IN ITS WAKE WE WILL HAVE LOW CLOUDS AND FOG DEVELOP
AND BRING WIDESPREAD IFR OR BELOW...WHICH WILL LINGER INTO TUESDAY
MORNING. THE LOW CLOUDS AND FOG WILL LIFT/BREAK UP BY AROUND MID
DAY. SOME LIMITED REDEVELOPMENT OF SHOWERS/THUNDERSTORMS COULD
OCCUR DURING THE DAY TUESDAY...MAINLY IN SOUTHEAST KY. AS LESS
HUMID AIR FINALLY BEGINS TO ARRIVE BY THE END OF THE PERIOD...DRY
WEATHER WILL ARRIVE AND BE WITH US FOR A NUMBER OF DAYS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
915 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 915 PM EDT MON AUG 10 2015
CONDITIONS ACROSS THE REGION WERE VFR AT THE START OF THE
PERIOD. HOWEVER...A BROKEN LINE OF THUNDERSTORMS WAS JUST NORTH
OF THE JKL FORECAST AREA. IT WAS ASSOCIATED WITH A COLD FRONT
WHICH WILL DROP SOUTH THROUGH THE REGION TONIGHT...BRINGING
SCATTERED SHOWERS AND THUNDERSTORMS AND LOCALIZED IFR. MOST OF
THE PRECIPITATION WILL DIMINISH OR MOVE OUT TO THE SOUTHEAST
BEFORE DAWN. IN ITS WAKE WE WILL HAVE LOW CLOUDS AND FOG DEVELOP
AND BRING WIDESPREAD IFR OR BELOW...WHICH WILL LINGER INTO TUESDAY
MORNING. THE LOW CLOUDS AND FOG WILL LIFT/BREAK UP BY AROUND MID
DAY. SOME LIMITED REDEVELOPMENT OF SHOWERS/THUNDERSTORMS COULD
OCCUR DURING THE DAY TUESDAY...MAINLY IN SOUTHEAST KY. AS LESS
HUMID AIR FINALLY BEGINS TO ARRIVE BY THE END OF THE PERIOD...DRY
WEATHER WILL ARRIVE AND BE WITH US FOR A NUMBER OF DAYS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
345 PM EDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 230 PM EDT SUN AUG 9 2015
CONDITIONS WILL BE VFR EVENING STILL A BIT OF UNCERTAINTY IN HOW
MUCH FOG WILL PLAY A ROLE...IF ANY...IN TAFS TONIGHT GIVEN
INCREASING HIGH AND THEN MID LEVEL CLOUDS AHEAD OF THE APPROACHING
COLD FRONT. ACCORDINGLY...HAVE LEANED AWAY FROM ANY SIGNIFICANT
FOG AND INSTEAD FOCUSED ON THE POTENTIAL FOR A SEMI-ORGANIZED
CLUSTER OF SHOWERS AND STORMS TO MOVE THROUGH DURING THE EARLY
MORNING HOURS OF MONDAY. INTRODUCED A TEMPO WITH CIGS AND VIS
INTO THE IFR TO MVFR RANGE WITH THE CONVECTION. ADDITIONAL STORMS
WILL BE POSSIBLE THROUGH THE REST OF THE DAY WITH VCTS PREVAILING
IN THE TAFS AFTER THE FIRST ROUND FADES OUT. ALTHOUGH NEAR STORM
WINDS COULD BE NEAR 25 KTS...THE BULK OF THE TIME THEY WILL BE
LIGHT AND VARIABLE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
123 PM EDT SUN AUG 9 2015
...UPDATED AVIATION DISCUSSION...
...FORECAST UPDATE...
ISSUED AT 855 AM EDT SUN AUG 9 2015
HAVE A NEW NORTH/SOUTH ORIENTED BAND OF STORMS FORMING OVER
SOUTHWEST ILLINOIS THIS HOUR. THE HRRR FROM 08-09Z HAD THIS
BAND...BUT THE LATEST RUN DOES NOT. THE EARLIER RUNS SHOWED THIS
BAND DISSIPATING BEFORE IT GETS INTO OUR REGION...BUT DOES SHOW A
CHANCE IN THE MID TO LATE AFTERNOON HOURS FOR SOME LIGHT RAINS WITH
PERHAPS A RUMBLE OF THUNDER OVER OUR NORTHERN FORECAST HOUR. STILL
LOOKING LIKE A SWATH OF STORMS WILL MOVE ACROSS SOME PARTS OF THE
REGION OVERNIGHT. MADE SOME SLIGHT TWEAKS TO THE EVENING FORECAST
POPS...AS WELL AS BLENDED CURRENT OBS INTO THE ONGOING FORECAST.
.SHORT TERM (NOW THROUGH MONDAY)...
ISSUED AT 330 AM EDT SUN AUG 9 2015
IN THE NEAR TERM, CLEAR TO PARTLY CLOUDY SKIES WERE NOTED ACROSS THE
FORECAST AREA. EARLY MORNING TEMPERATURES WERE IN THE MID-UPPER
60S. SOME PATCHY FOG WAS DEVELOPING ACROSS THE TYPICAL FOG PRONE
AREAS. CLEAR TO PARTLY CLOUDY SKIES WILL CONTINUE FOR THE REMAINDER
OF THE NIGHT WITH LOW TEMPERATURES HITTING THEIR MINIMUMS TOWARD
DAWN.
FOR TODAY, THE OHIO VALLEY WILL SEE ONE MORE DAY UNDER THE INFLUENCE
OF AN UPPER LEVEL RIDGE. WE`RE ON THE NORTHEASTERN PERIPHERY OF THE
RIDGE AXIS AND THIS RIDGE IS FORECAST TO RETROGRADE WESTWARD THROUGH
THE PERIOD. AS THIS OCCURS, WE`LL SEE OUR FLOW PATTERN REVERT BACK
TO A NORTHWESTERLY FLOW. WITHIN THIS NORTHWESTERLY FLOW, A SERIES
OF MID-LEVEL WAVES ROTATING AROUND THE EDGE OF THE RIDGE WILL ROLL
THROUGH THE REGION. CLOUDS WILL BE ON THE INCREASE TODAY WITH HIGH
CIRRUS ROLLING INTO THE REGION. AFTERNOON HIGHS SHOULD BE SLIGHTLY
WARMER THAN WHAT WE SAW SATURDAY AFTERNOON WITH MID-UPPER 80S ACROSS
THE REGION.
FOR TONIGHT, THE FIRST IN A SERIES OF WAVES WILL PUSH INTO THE
REGION LATE. THIS FEATURE SHOULD SPAWN AN MCS TO OUR NORTHWEST
WHICH SHOULD THEN DIVE EAST-SOUTHEAST. BY THE TIME IT REACHES OUR
AREA EARLY MONDAY MORNING, IT IS FORECAST TO BE IN A WEAKENING
PHASE. NONETHELESS, WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
LOOKS LIKELY LATE TONIGHT AND INTO MONDAY MORNING. THEREFORE, WILL
CONTINUE HIGH POPS FOR LATE TONIGHT. TEMPERATURES LOOK TO REMAIN
MILD WITH LOWS IN THE UPPER 60S TO THE LOWER 70S.
FOR MONDAY, SOMEWHAT OF A MORE COMPLEX FORECAST HERE AS WIDESPREAD
CONVECTION IN THE MORNING HOURS WILL LIKELY RESULT IN MORE LIMITED
INSTABILITY AS A FRONT PUSHES IN FROM THE NORTHWEST. MID-LEVEL FLOW
STILL LOOKS TO BE DECENT WITH 30-35 KT MID-LEVEL FLOW OVERSPREADING
THE REGION. HOWEVER, QUESTION REMAINS HOW MUCH CLOUD COVER WILL
LIMIT INSTABILITY. BASED ON THERMODYNAMIC AND KINEMATIC PROFILES,
MULTI-CELLULAR CONVECTION SEEMS TO BE THE PRIMARY CONVECTIVE MODE ON
MONDAY WITH GUSTY WINDS BEING THE MAIN THREAT WITH A LOWER LEVEL
THREAT OF MARGINALLY SEVERE HAIL. CLOUDS AND PRECIPITATION WILL
LIKELY HOLD TEMPERATURES DOWN WITH READINGS GENERALLY IN THE MIDDLE
80S. IF CURRENT MODEL TRENDS CONTINUE, SOME DOWNWARD ADJUSTMENT IN
MAX TEMPS MONDAY MAY BE REQUIRED IN SUBSEQUENT FORECASTS.
.LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
ISSUED AT 300 AM EDT SUN AUG 9 2015
AT THE START OF THE EXTENDED PERIOD MONDAY NIGHT, A SURFACE COLD
FRONT WILL PUSH THROUGH SOUTH-CENTRAL INDIANA AND CENTRAL KENTUCKY
AS A MID-LEVEL TROUGH DIGS ACROSS THE GREAT LAKES STATES. WHILE MUCH
OF THE DEEP-LAYERED MOISTURE WILL HAVE PUSHED TO OUR EAST, RESIDUAL
LOW-LEVEL MOISTURE AND INSTABILITY COMBINED WITH MODEST FRONTAL
CONVERGENCE SHOULD BE ENOUGH TO FORCE ISOLATED/SCATTERED CONVECTION
ALONG/AHEAD OF THE FRONT MONDAY EVENING, BEFORE WEAKENING OVERNIGHT.
THEREAFTER, THE EXTENDED PERIOD WILL BE CHARACTERIZED BY A MID-LEVEL
AVERAGE TROUGH POSITION ALONG THE EAST COAST, AND A PERSISTENT RIDGE
FROM THE SOUTHWEST U.S. NORTHWARD INTO THE NORTHERN HIGH PLAINS.
THIS WILL KEEP A DRY NORTHWEST FLOW ALOFT OVER THE OHIO VALLEY AS
HIGH PRESSURE AT THE SURFACE BUILDS FROM THE MIDWEST BEHIND THE
FRONT BEFORE SETTLING ACROSS THE OHIO VALLEY FOR THE MID AND LATTER
PORTIONS OF THIS COMING WEEK. MODELS DO SUGGEST THAT WEAK DIURNAL
INSTABILITY COULD DEVELOP TUESDAY AFTERNOON WITH COOL NORTHWEST FLOW
ALOFT, SO WILL KEEP A SLIGHT CHANCE OF SHOWERS OVER OUR SOUTHEAST
COUNTIES IN CENTRAL KY.
AS HIGH PRESSURE SETTLES IN, HIGH TEMPERATURES WILL BE SEVERAL
DEGREES BELOW NORMAL BY MID NEXT WEEK, PEAKING OUT ONLY IN THE UPPER
70S AND LOWER 80S WEDNESDAY AND THURSDAY. HUMIDITY LEVELS (SURFACE
DEWPOINTS) WILL BE LOW AS WELL. LOW TEMPERATURES THURSDAY AND FRIDAY
MORNINGS SHOULD RANGE FROM THE MID 50S TO LOWER 60S. BY NEXT
WEEKEND, TEMPERATURES SHOULD RETURN TO NEAR OR ABOVE NORMAL AS
SUMMER AIR RETURNS.
&&
.AVIATION (18Z TAF UPDATE)...
ISSUED AT 120 PM EDT SUN AUG 9 2015
CONTINUE TO SEE BANDS OF STORMS FORM UPSTREAM AND THEN FADE AS THEY
APPROACH SOUTHWEST INDIANA. MODEL AND AMDAR SOUNDINGS SHOW A STABLE
LAYER AROUND 800 MB OVER KSDF...BUT THIS AIR SHOULD BECOME MODIFIED
THROUGH THE AFTERNOON. A FEW OF THE HIGH-RES MODELS INDICATE SOME
STORMS COULD NEAR THE KSDF TERMINAL EARLIER THAN WHAT IS IN THIS
TAF, BUT WENT WITH THE MAJORITY AND HELD OFF STORM CHANCES UNTIL 3Z.
CHANCES ARE LOWER FOR THOSE STORMS MAKING IT TO KLEX/KBWG...BUT
ENOUGH TO PUT IN A PROB30 GROUP AROUND DAYBREAK MONDAY. THINK BY
LATE MORNING THERE SHOULD BE A BREAK IN THE STORM CHANCES AT EACH
SITE...BUT CANNOT RULE OUT SOME LIGHT RAINS. SWITCHED OVER TO
VICINITY SHOWERS AT THAT POINT.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
UPDATE.........RJS
SHORT TERM.....MJ
LONG TERM......TWF
AVIATION.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
855 AM EDT SUN AUG 9 2015
...FORECAST UPDATE...
ISSUED AT 855 AM EDT SUN AUG 9 2015
HAVE A NEW NORTH/SOUTH ORIENTED BAND OF STORMS FORMING OVER
SOUTHWEST ILLINOIS THIS HOUR. THE HRRR FROM 08-09Z HAD THIS
BAND...BUT THE LATEST RUN DOES NOT. THE EARLIER RUNS SHOWED THIS
BAND DISSIPATING BEFORE IT GETS INTO OUR REGION...BUT DOES SHOW A
CHANCE IN THE MID TO LATE AFTERNOON HOURS FOR SOME LIGHT RAINS WITH
PERHAPS A RUMBLE OF THUNDER OVER OUR NORTHERN FORECAST HOUR. STILL
LOOKING LIKE A SWATH OF STORMS WILL MOVE ACROSS SOME PARTS OF THE
REGION OVERNIGHT. MADE SOME SLIGHT TWEAKS TO THE EVENING FORECAST
POPS...AS WELL AS BLENDED CURRENT OBS INTO THE ONGOING FORECAST.
.SHORT TERM (NOW THROUGH MONDAY)...
ISSUED AT 330 AM EDT SUN AUG 9 2015
IN THE NEAR TERM, CLEAR TO PARTLY CLOUDY SKIES WERE NOTED ACROSS THE
FORECAST AREA. EARLY MORNING TEMPERATURES WERE IN THE MID-UPPER
60S. SOME PATCHY FOG WAS DEVELOPING ACROSS THE TYPICAL FOG PRONE
AREAS. CLEAR TO PARTLY CLOUDY SKIES WILL CONTINUE FOR THE REMAINDER
OF THE NIGHT WITH LOW TEMPERATURES HITTING THEIR MINIMUMS TOWARD
DAWN.
FOR TODAY, THE OHIO VALLEY WILL SEE ONE MORE DAY UNDER THE INFLUENCE
OF AN UPPER LEVEL RIDGE. WE`RE ON THE NORTHEASTERN PERIPHERY OF THE
RIDGE AXIS AND THIS RIDGE IS FORECAST TO RETROGRADE WESTWARD THROUGH
THE PERIOD. AS THIS OCCURS, WE`LL SEE OUR FLOW PATTERN REVERT BACK
TO A NORTHWESTERLY FLOW. WITHIN THIS NORTHWESTERLY FLOW, A SERIES
OF MID-LEVEL WAVES ROTATING AROUND THE EDGE OF THE RIDGE WILL ROLL
THROUGH THE REGION. CLOUDS WILL BE ON THE INCREASE TODAY WITH HIGH
CIRRUS ROLLING INTO THE REGION. AFTERNOON HIGHS SHOULD BE SLIGHTLY
WARMER THAN WHAT WE SAW SATURDAY AFTERNOON WITH MID-UPPER 80S ACROSS
THE REGION.
FOR TONIGHT, THE FIRST IN A SERIES OF WAVES WILL PUSH INTO THE
REGION LATE. THIS FEATURE SHOULD SPAWN AN MCS TO OUR NORTHWEST
WHICH SHOULD THEN DIVE EAST-SOUTHEAST. BY THE TIME IT REACHES OUR
AREA EARLY MONDAY MORNING, IT IS FORECAST TO BE IN A WEAKENING
PHASE. NONETHELESS, WIDESPREAD SHOWER AND THUNDERSTORM ACTIVITY
LOOKS LIKELY LATE TONIGHT AND INTO MONDAY MORNING. THEREFORE, WILL
CONTINUE HIGH POPS FOR LATE TONIGHT. TEMPERATURES LOOK TO REMAIN
MILD WITH LOWS IN THE UPPER 60S TO THE LOWER 70S.
FOR MONDAY, SOMEWHAT OF A MORE COMPLEX FORECAST HERE AS WIDESPREAD
CONVECTION IN THE MORNING HOURS WILL LIKELY RESULT IN MORE LIMITED
INSTABILITY AS A FRONT PUSHES IN FROM THE NORTHWEST. MID-LEVEL FLOW
STILL LOOKS TO BE DECENT WITH 30-35 KT MID-LEVEL FLOW OVERSPREADING
THE REGION. HOWEVER, QUESTION REMAINS HOW MUCH CLOUD COVER WILL
LIMIT INSTABILITY. BASED ON THERMODYNAMIC AND KINEMATIC PROFILES,
MULTI-CELLULAR CONVECTION SEEMS TO BE THE PRIMARY CONVECTIVE MODE ON
MONDAY WITH GUSTY WINDS BEING THE MAIN THREAT WITH A LOWER LEVEL
THREAT OF MARGINALLY SEVERE HAIL. CLOUDS AND PRECIPITATION WILL
LIKELY HOLD TEMPERATURES DOWN WITH READINGS GENERALLY IN THE MIDDLE
80S. IF CURRENT MODEL TRENDS CONTINUE, SOME DOWNWARD ADJUSTMENT IN
MAX TEMPS MONDAY MAY BE REQUIRED IN SUBSEQUENT FORECASTS.
.LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
ISSUED AT 300 AM EDT SUN AUG 9 2015
AT THE START OF THE EXTENDED PERIOD MONDAY NIGHT, A SURFACE COLD
FRONT WILL PUSH THROUGH SOUTH-CENTRAL INDIANA AND CENTRAL KENTUCKY
AS A MID-LEVEL TROUGH DIGS ACROSS THE GREAT LAKES STATES. WHILE MUCH
OF THE DEEP-LAYERED MOISTURE WILL HAVE PUSHED TO OUR EAST, RESIDUAL
LOW-LEVEL MOISTURE AND INSTABILITY COMBINED WITH MODEST FRONTAL
CONVERGENCE SHOULD BE ENOUGH TO FORCE ISOLATED/SCATTERED CONVECTION
ALONG/AHEAD OF THE FRONT MONDAY EVENING, BEFORE WEAKENING OVERNIGHT.
THEREAFTER, THE EXTENDED PERIOD WILL BE CHARACTERIZED BY A MID-LEVEL
AVERAGE TROUGH POSITION ALONG THE EAST COAST, AND A PERSISTENT RIDGE
FROM THE SOUTHWEST U.S. NORTHWARD INTO THE NORTHERN HIGH PLAINS.
THIS WILL KEEP A DRY NORTHWEST FLOW ALOFT OVER THE OHIO VALLEY AS
HIGH PRESSURE AT THE SURFACE BUILDS FROM THE MIDWEST BEHIND THE
FRONT BEFORE SETTLING ACROSS THE OHIO VALLEY FOR THE MID AND LATTER
PORTIONS OF THIS COMING WEEK. MODELS DO SUGGEST THAT WEAK DIURNAL
INSTABILITY COULD DEVELOP TUESDAY AFTERNOON WITH COOL NORTHWEST FLOW
ALOFT, SO WILL KEEP A SLIGHT CHANCE OF SHOWERS OVER OUR SOUTHEAST
COUNTIES IN CENTRAL KY.
AS HIGH PRESSURE SETTLES IN, HIGH TEMPERATURES WILL BE SEVERAL
DEGREES BELOW NORMAL BY MID NEXT WEEK, PEAKING OUT ONLY IN THE UPPER
70S AND LOWER 80S WEDNESDAY AND THURSDAY. HUMIDITY LEVELS (SURFACE
DEWPOINTS) WILL BE LOW AS WELL. LOW TEMPERATURES THURSDAY AND FRIDAY
MORNINGS SHOULD RANGE FROM THE MID 50S TO LOWER 60S. BY NEXT
WEEKEND, TEMPERATURES SHOULD RETURN TO NEAR OR ABOVE NORMAL AS
SUMMER AIR RETURNS.
&&
.AVIATION (12Z TAF UPDATE)...
ISSUED AT 635 AM EDT SUN AUG 9 2015
QUIET WEATHER CONDITIONS ARE EXPECTED AT THE TAF SITES TODAY. SOME
PATCHY FOG WILL BE POSSIBLE AT THE TEMRINALS THIS
MORNING...ESPECIALLY KBWG AND KLEX. THIS FOG SHOULD MIX OUT BY
09/13Z WITH VFR CONDITIONS RETURNING. VFR CONDITIONS ARE EXPECTED
THROUGH THE DAY WITH LIGHT AND VARIABLE WINDS.
CLOUDS WILL BE ON THE INCREASE LATE THIS EVENING AHEAD OF AN
APPROACHING MID-LEVEL WAVE. PRECIPITATION ASSOCIATED WITH THIS
SYSTEM LOOKS TO OCCUR LATE IN THE FORECAST PERIOD...PERHAPS HOLDING
OFF UNTIL JUST AFTER THE FORECAST PERIOD.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
UPDATE.........RJS
SHORT TERM.....MJ
LONG TERM......TWF
AVIATION.......MJ
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
306 PM EDT SUN AUG 9 2015
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY MOVE TO THE NORTHEAST TONIGHT. A
WARM FRONT WILL APPROACH FROM THE SOUTHWEST MONDAY AND LIFT TO THE
NORTH MONDAY NIGHT. A COLD FRONT WILL THEN SWEEP EASTWARD TUESDAY
AFTERNOON. HIGH PRESSURE BUILDS IN AGAIN BY MIDWEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
BROAD BUT WEAK HIGH PRESSURE STRETCHES ALONG THE EASTERN SEABOARD
THIS AFTERNOON. A ZONAL UPPER LEVEL JET STRETCHES ACROSS THE GREAT
LAKES. THERE IS ENOUGH MOISTURE IN THE COLUMN TO PRODUCE MOSTLY
CLOUDY SKIES AT TIMES AS WELL AS ISOLATED/SCATTERED SHOWERS THIS
AFTERNOON. MOST OF THESE ARE BEING DRIVEN BY THE
TERRAIN...ALTHOUGH ONE ALSO DEVELOPED NORTH OF BALTIMORE. THUNDER
SHOULD BE LIMITED TO WESTERN AREAS IF THERE IS ANY...AS THIS IS
WHERE INSTBY IS SLIGHTLY HIGHER.
I DON/T HAVE THE HIGHEST CONFIDENCE IN THE FORECAST OVERNIGHT IN
REGARDS TO SHOWERS AS ANY FORCING WILL BE SUBTLE. MODELS HAVE HAD
SLIGHT DIFFERENCES ON HOW TO HANDLE VORT MAX APPROACHING FROM
ILLINOIS...AS WELL AS THE MAGNITUDE OF A POSSIBLE LOW LEVEL JET
DEVELOPING LATE EAST OF THE MOUNTAINS. HAVE NOT USED THE 09.12Z
12KM NAM AFTER 06Z THOUGH AS ITS RAPID CYCLOGENESIS OVER LAKE
ERIE SEEMS SPURIOUS AND IS NOT SUPPORTED ELSEWHERE. NEVERTHELESS
AS A MAJORITY OF BOTH SYNOPTIC AND MESOSCALE MODELS PAINT SOME
SORT OF PRECIP POTENTIAL THROUGH THE NIGHT...HAVE MAINTAINED THE
SLIGHT CHANCE POPS PROGRESSING EASTWARD WITH TIME. AS DEW POINTS
RISE...OVERNIGHT LOWS WILL BE LIMITED TO THE MID 60S TO LOWER 70S.
SIMILAR UNCERTAINTY IN THE COVERAGE IN SHOWERS CONTINUES THROUGH
MONDAY MORNING. THERE WILL BE BROAD ISENTROPIC LIFT IN A MOIST
ENVIRONMENT THOUGH SO CANNOT RULE OUT A FEW SHOWERS. STRONGER
FORCING ASSOCIATED WITH A DIGGING UPPER LEVEL TROUGH WILL REMAIN
TO THE WEST DURING THE MORNING. THEREFORE IT APPEARS THE CHANCE
OF SHOWERS AND SOME THUNDERSTORMS WILL INCREASE DURING THE
AFTERNOON FROM WEST TO EAST. IT WILL BE A MOSTLY CLOUDY DAY...SO
INSTBY SHOULD BE LIMITED. DEEP LAYER SHEAR ALSO DOES NOT INCREASE
INTO VERY LATE IN THE DAY. WHILE THERE MAY BE A FEW STRONGER
STORMS...MOST SHOULD JUST BE HEAVY RAINERS AS PWATS INCREASE
APPRECIABLY. HIGHS MAY MAKE IT INTO THE LOWER TO MID 80S BEFORE
THE SHOWERS BECOME MORE WIDESPREAD.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
A WARM FRONT EXTENDING FROM LOW PRESSURE OVER THE OHIO VALLEY WILL
CROSS THE REGION OVERNIGHT MONDAY NIGHT. INSTABILITY WILL GRADUALLY
INCREASE THROUGH THE NIGHT...AND COUPLED WITH ISENTROPIC LIFT WILL
LIKELY GENERATE SCATTERED TO NUMEROUS SHOWERS AND EMBEDDED
THUNDERSTORMS. HEAVY DOWNPOURS ARE POSSIBLE WITH STRONGER ACTIVITY
AS PRECIPITABLE WATER VALUES EXCEED 1.75 INCHES. ONCE HEATING
COMMENCES TUESDAY MORNING...AS LONG AS LOW-LEVEL SHEAR ALONG THE
WARM FRONT IS STILL LINGERING THEN THERE COULD BE A BRIEF SPIN UP.
OTHERWISE...BETTER CHANCE FOR STRONG TO SEVERE STORMS WOULD BE ALONG
AND AHEAD OF A COLD FRONT TUESDAY AFTERNOON. THERE IS UNCERTAINTY AS
TO HOW FAR EAST THE FRONT GETS BY PEAK HEATING...WHICH WILL
DETERMINE WHICH AREAS HAVE THE BETTER CHANCES OF CONVECTION. OF SOME
CONCERN IS MODEL SOUNDINGS DEPICTING THE FATTER PART OF CAPE
PROFILES IN THE HAIL GROWTH ZONE /AROUND -20 C/ WHICH WOULD SUPPORT
STRONG ELEVATED CORES WITH DOWNBURSTS/HAIL. EFFECTIVE BULK SHEAR
APPROACHES 30 KT DURING THE AFTERNOON AND COULD LEND TO SOME
MULTICELLULAR ORGANIZATION/GUSTY WIND POTENTIAL AS WELL. GIVEN
UNCERTAINTIES IN FRONTAL PLACEMENT/CLOUD COVER/INSTABILITY...OVERALL
RISK APPEARS MARGINAL FOR NOW AND CONFINED TO EAST OF THE BLUE RIDGE
MOUNTAINS TUE /THOUGH AN ISOLATED STRONG STORM COULD FIND ITS WAY
OVER THE MOUNTAINS MON NIGHT FURTHER WEST/.
THE FRONT WILL MOVE OFFSHORE...ENDING THE THREAT OF SHOWERS AND
STORMS TUESDAY EVENING.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ESSENTIALLY NOTHING HAS CHANGED SINCE THIS TIME YESTERDAY WITH
REGARDS TO FORECAST FOR THE LONG TERM. COLD FRONT THAT PASSES
THROUGH TUESDAY WILL SCOUR OUT QUALITY MOISTURE...WHICH WILL LEAVE
CWA IN AN EXTENDED PERIOD OF WARM...COMFORTABLE...AND PRECIP FREE
WEATHER.
HIGH PRESSURE BEHIND THE FRONT BUILDS IN THROUGH THE WEEK...AND WITH
LITTLE CLOUD COVER AND LOWER DEWPOINTS...EXPECT STRONG RADIATIONAL
COOLING AT NIGHT...ESPECIALLY AS THE HIGH BUILDS OVERHEAD THURSDAY
INTO FRIDAY MORNING. AS MENTIONED YESTERDAY...TEMPS ALONG OUR FAR
WESTERN BORDER COULD DROP INTO THE U40S THURSDAY AND FRIDAY MORNING.
ELSEWHERE...EXPECT LOWS GENERALLY IN THE 50S WEST OF BLUE RIDGE AND
L/M60S EAST...WITH U60S IN URBAN AREAS.
LITTLE CLOUD COVER THROUGH THE PERIOD WILL ALSO LEAD TO STRONG
DAYTIME HEATING...SO EXPECT TEMPS TO GRADUALLY RISE EACH DAY AS
AIRMASS SLOWLY MODIFIES. BY FRIDAY AND SATURDAY...HIGH TEMPS WILL
RETURN TO AOA NORMAL.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL A MAJORITY OF THE TIME THROUGH THIS
AFTERNOON ALTHOUGH CIGS COULD BE AS LOW AS 4 KFT AT TIMES. SOME
SHOWERS ARE POPPING ACROSS THE MOUNTAINS...WITH MRB BEING THE MOST
LIKELY TO BE AFFECTED...BUT COULD REACH THE OTHER TERMINALS AS
WELL. HOWEVER...ANY AVIATION IMPACTS WOULD BE BRIEF. A STRAY
SHOWER WILL REMAIN POSSIBLE OVERNIGHT INTO MONDAY
MORNING...ALTHOUGH AREAL COVERAGE IS LOWER CONFIDENCE. WINDS WILL
REMAIN LESS THAN 10 KT THROUGH TONIGHT. SHOWERS AND PERHAPS A
THUNDERSTORM WILL BECOME INCREASINGLY LIKELY FROM WEST TO EAST
MONDAY AFTERNOON. BRIEF VSBY REDUCTIONS WILL BE POSSIBLE AS RAIN
COULD BE LOCALLY HEAVY. SOUTHERLY WINDS MAY GUST UP TO 15-20 KT.
IFR PSBL MON NIGHT-TUE AM W/ LWR CIGS/VSBYS IN SHRA/ISO
TSTMS AHEAD OF WARM FRONT. SELY WIND 10-15 KT AT THE
SURFACE...VEERING TO WLY AROUND 30 KT AT 2 KFT. RESTRICTIONS PSBL
TUE IN SCTD TSTMS AHEAD OF COLD FRONT. SWLY WIND 10-15 KT.
TIMING/PLACEMENT OF FRONT AND SUBSEQUENT TSTMS CHANCES/EXACT WIND
DIRECTION A BIT UNCERTAIN AT THIS TIME. FRONT MOVES OFFSHORE TUE
EVE...VFR RETURNS W/ NWLY FLOW AOB 10 KT.
VFR EXPECTED FROM TUESDAY NIGHT ONWARD UNDER HIGH PRESSURE.
&&
.MARINE...
LIGHT WINDS WILL CONTINUE UNDER HIGH PRESSURE THROUGH THIS
AFTERNOON. A STRAY SHOWER MAY CROSS THE NORTHERN BAY. BIGGEST
CHANGE TO THE FORECAST IS THAT THE PREPONDERANCE OF GUIDANCE IS NOW
SUGGESTING A LOW LEVEL JET AND SOUTHERLY CHANNELING WILL BEGIN
OVER THE BAY THIS EVENING. HAVE ISSUED A SCA UP TO POOLES ISLAND
FOR THIS. HAVE ENDED THIS AT 3 AM AS GFS AND RAP SHOW LOW LEVEL
WINDS DECREASING. SOUTHERLY FLOW WILL THEN INCREASE AGAIN DURING
THE DAY MONDAY AHEAD OF AN APPROACHING FRONT. EXPANDED THE SCA TO
ALL WATERS BEGINNING AT NOON. WHILE A SHOWER OR STORM COULD POP
UP AT NEARLY ANY TIME OF THE DAY...SUBSTANTIAL COVERAGE IS NOT
EXPECTED UNTIL AT LEAST LATE AFTERNOON.
SOUTHERLY LLJ OF ABOUT 30 KT AROUND 2000 FEET MON NIGHT
WILL LEND TO SOLID SCA GUSTS. WIND GUSTS AT THE SURFACE COULD EXCEED
30 KT IN HEAVIER ACTIVITY ESPECIALLY EARLY TUE AM. COULD BE SOME
GUSTY WINDS W/ SCTD TSTM ACTIVITY TUE PM AS WELL...BUT CONFIDENCE
TOO MARGINAL AT THIS POINT TO INCLUDE A MENTION IN THE HWO.
NO MARINE HAZARDS EXPECTED FROM WEDNESDAY THROUGH THE REMAINDER OF
THE PERIOD...AS HIGH PRESSURE DOMINATES.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES ARE NOW INCREASING ABOVE ONE FOOT AT MOST COASTAL
LOCATIONS. CONSIDERING RECENT TRENDS...IT IS LIKELY ANNAPOLIS AND
STRAITS POINT WILL EXCEED MINOR FLOOD THRESHOLDS DURING THE PM
TIDE CYCLE. A FEW OTHER SITES WILL NEED TO BE WATCHED THOUGH.
WITH SOUTHERLY/SOUTHEASTERLY FLOW...THE EXISTING ANOMALY LIKELY
PERSISTS OR BUILDS MONDAY INTO TUESDAY. A MORE WIDESPREAD COASTAL
FLOOD THREAT WILL LIKELY DEVELOP DURING THIS TIME...ESPECIALLY
DURING THE HIGHER-ASTRONOMICALLY OVERNIGHT TIDE CYCLES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EDT
MONDAY FOR MDZ014.
COASTAL FLOOD ADVISORY FROM 8 PM THIS EVENING TO 1 AM EDT
MONDAY FOR MDZ017.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 3 AM EDT MONDAY
FOR ANZ531>534-537>543.
SMALL CRAFT ADVISORY FROM NOON MONDAY TO 6 AM EDT TUESDAY FOR
ANZ530>543.
&&
$$
SYNOPSIS...ADS
NEAR TERM...ADS
SHORT TERM...DFH
LONG TERM...MSE
AVIATION...ADS/MSE/DFH
MARINE...ADS/MSE/DFH
TIDES/COASTAL FLOODING...ADS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
803 PM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 803 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS DROP ACROSS LK SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN
ON NORTH WINDS. CIGS SHOULD SETTLE INTO LOW MVFR RANGE AROUND
SUNRISE ON TUESDAY...WITH SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH
DRYING BY AFTERNOON FOR CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ251-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
332 PM EDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN AUG 9 2015
A NW FLOW BTWN AN UPR RDG IN THE PLAINS AND A DOWNSTREAM TROF OVER
ERN CANADA WL DOMINATE THE GREAT LKS EARLY THIS WEEK...BRINGING A
PERIOD OF BLO NORMAL TEMPS FOR MON NGT INTO WED. WARMER WX AND A CHC
OF SHOWERS/TS WL THEN BE THE RULE ON THU IN ADVANCE OF A COLD FNT
ASSOCIATED WITH A DISTURBANCE DROPPING SEWD THRU NW ONTARIO. EXPECT
DRY AND A BIT COOLER WX LATE IN THE WEEK WITH HI PRES TRAILING THE
FNT. THE NEXT CHC OF SHOWERS/TS AND WARMER WX WL RETURN NEXT SUN
AHEAD OF THE NEXT SHRTWV/COLD FNT TOPPING THE PERSISTENT UPR RDG IN
THE PLAINS.
MON NGT...SHRTWV DIVING SEWD IN THE NW FLOW ALF BTWN PLAINS RDG AND
ERN TROF IS FCST TO DIG THRU THE AREA. SOME OF THE MODELS SHOW SOME
WEAK DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE PVA AHEAD OF THIS
DISTURBANCE AND GENERATE SOME SPOTTY LGT PCPN OVER THE AREA...MAINLY
OVER THE HIER TERRAIN NEAR LK SUP WITH UPSLOPE N WINDS. BUT ABSENCE
OF STRONGER FORCING AND ARRIVAL OF THIS DISTURBANCE DURING PERIOD OF
NOCTURNAL COOLING WL LIMIT INTENSITY AND COVERAGE OF ANY SHOWERS. DO
EXPECT MORE LO CLDS IN THESE UPSLOPE AREAS WITH AN INCRS IN LLVL RH
AS H85 TEMPS WITHIN THERMAL TROF FALL TO 8-10C BY 12Z TUE. STEADY N
WINDS WL LIMIT THE DIURNAL TEMP FALL DESPITE THE LLVL COOLING TREND.
MOST PLACES SHOULD SEE MINS IN THE 50S...WITH THE LOWER TEMPS AT THE
COOLER SPOTS OVER THE INTERIOR W HALF WHERE THE WINDS WL BE A BIT
LIGHTER CLOSER TO SFC HI PRES RDG BLDG INTO MN.
TUE/TUE NGT...EXPECT DRY WX TO PREVAIL DURING THIS TIME UNDER
CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR DVGC/SUBSIDENCE LEFT IN THE
WAKE OF EXITING SHRTWV. SC IN THE UPSLOPE AREAS ON TUE MRNG SHOULD
EXPAND WITH DAYTIME HEATING UNDER THERMAL TROF...BUT CLOSER APRCH OF
SFC HI PRES FCST TO ARRIVE OVER THE W BY 00Z WED/INCRSGLY ACYC LLVL
FLOW/LOWERING SUBSIDENCE INVRN WL LIKELY RESULT IN MORE SUNSHINE W-E
THRU THE AFTN. UNDER MOCLR SKIES...TUE NGT WL BE COOL ESPECIALLY
OVER THE INTERIOR W HALF WITH LIGHTER WINDS CLOSER TO SFC HI PRES
RDG SINKING INTO WI. BUT WITH MIN PWAT NOT MUCH BLO 0.75 INCH IN
THIS AREA...DO NOT EXPECT MIN TEMPS TO BE TOO CHILLY.
WED/WED NGT...SFC HI PRES IS FCST TO SINK S INTO THE MID MS RIVER
VALLEY THRU THIS TIME. AS THE MSLP FALLS OVER NW ONTARIO IN ADVANCE
OF SHRTWV RIDING OVER THE TOP OF PLAINS RDG INTO FAR NW ONTARIO...
UPR MI WL BE DOMINATED BY AN INCRSG WSW FLOW. EXPECT SOME CLDS
ASSOCIATED WITH BAND OF INCRSG WAA/ISENTROPIC ASCENT BEST SHOWN ON
THE 300-305K SFCS TO IMPACT THE UPR LKS WED AFTN/EVNG. MANY OF THE
MODELS GENERATE SOME PCPN AS WELL...BUT RELATIVE DRYNESS OF THE
LLVLS AND MODEST PWAT FCST NEAR 1 INCH /ABOUT NORMAL/ WARRANT ONLY
LO CHC POPS.
THU/THU NGT...SHRTWV OVER FAR NW ONTARIO AT 12Z THU IS PROGGED TO
SLIDE SE INTO WRN QUEBEC THU NGT AND DRAG A COLD FNT ACRS UPR MI
SOMETIME THU AFTN/EVNG. ARRIVAL OF THIS BNDRY/BAND OF MODEST DEEP
LYR FORCING AT A TIME WHEN DAYTIME HEATING WL HAVE AN IMPACT FAVORS
SOME SHOWERS/TS...BUT ABSENCE OF MUCH IN THE WAY OF HGT FALLS WELL
TO THE SW OF TRACK OF SHRTWV/SHARPEST FORCING...QUESTIONS ABOUT
DEGREE OF MSTR INFLOW AHEAD OF THE FNT AND TIMING DIFFERENCES AMONG
THE MODELS ON FROPA TIMING WARRANT NO HIER THAN LO CHC POPS ATTM.
THU LOOKS TO BE A WARM DAY WITH H85 TEMPS PUSHING 18-20C AHEAD OF
THE FNT.
EXTENDED...HI PRES TRAILING THE COLD FROPA WL BRING MOCLR WX FOR FRI
AND SAT. FRI WL BE COOLER WITH H85 TEMPS DIPPING TO ARND 14C...BUT
THEN SAT WL TURN WARMER AS THE HI SHIFTS TO THE E AND RETURN SSW
FLOW LIFTS H85 TEMPS UP TO 16C. THE NEXT CHC OF SHOWERS/TS WL ARRIVE
ON SUN AHEAD OF NEXT DISTURBANCE RIDING OVER THE PLAINS RDG.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 150 PM EDT SUN AUG 9 2015
IFR TO MVFR CLOUDS THIS MORNING OVER THE WESTERN U.P. SHOULD LIMIT
THE THUNDER POTENTIAL AT KIWD/KCMX THIS AFTERNOON...BUT THE
NORTHERN EDGE OF A WEAK DISTURBANCE MOVING THROUGH THE AREA THIS
AFTERNOON COULD LEAD TO A STRAY SHOWER AT KIWD. HAVE SEEN CEILINGS
RISING OVER THE LAST TWO HOURS AT THOSE SITES AND THEY SHOULD
TRANSITION TO LOW END VFR THIS AFTERNOON. FARTHER TO THE EAST AT
KSAW...MORE SUNSHINE THIS MORNING HAS STARTED TO PRODUCE A LAKE
BREEZE NEAR MARQUETTE AND EXPECT THAT TO MOVE INLAND. PLANNING ON
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THAT BREEZE AND THIS
AFTERNOON AND PRODUCE A THUNDERSTORM AT KSAW. DID INCLUDE A TWO
HOUR PERIOD DURING GREATEST CONFIDENCE...AND COULD SEE CONDITIONS
FALL TO MVFR OR EVEN IFR DURING THE THUNDERSTORM.
ONCE THE COLD FRONT MOVES THROUGH THE AREA TONIGHT AND BREAKS IN
THE CLOUDS OCCUR...BELIEVE GROUND FOG WILL DEVELOP AT ALL THREE
SITES. WILL SHOW THE WORST CONDITIONS AT KSAW WITH THE HELP OF RAIN
THIS AFTERNOON AND THE LIGHTEST WINDS. DIDN/T GO TOO LOW OVER THE
WEST SITES...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH
THE NIGHT AND LEAD TO MORE MIXING INTO THE DRIER AIR ALOFT. WILL
NEED TO WATCH THE FOG OVER THE WESTERN LAKE...AS THAT COULD LEAD TO
LOWER CONDITIONS THAN FORECAST FOR KCMX. FINALLY FOR
TOMORROW...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE MONDAY AFTERNOON AND EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
308 PM EDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 444 AM EDT SUN AUG 9 2015
AT 12Z MONDAY THE APEX OF THE 500MB TROUGH /EXTENDING FROM THE LOW
OVER JAMES BAY/ WILL BE OVERHEAD...WITH SHOWERS EXITING THE E CWA.
A SECONDARY SHORTWAVE SWINGING AROUND THE MAIN TROUGH WILL PUSH IN
FROM THE NW MONDAY NIGHT. WITH LIMITED MOISTURE...DO NOT EXPECT MUCH
IN THE WAY OF PRECIP. MODELS DO SHOW SOME INCREASE IN LOW LEVEL
MOISTURE...BELOW 800MB...WITH THE BEST MOISTURE ASSISTED BY N-NNW
FLOW OVER THE E THIRD OF UPPER MI.
EXPECT A MAINLY N WIND TO REMAIN JUST ABOVE THE SFC THROUGH THE
FIRST HALF OF THE WORK WEEK. 850MB TEMPS OF 8-11C WILL HELP KEEP
AFTERNOON SFC TEMPS IN THE 70S MONDAY-WEDNESDAY. AT THIS POINT
TUESDAY LOOKS TO BE THE COOLEST DAY...WITH A FEW READINGS IN THE
UPPER 60S ALONG LAKE SUPERIOR AS A LARGE AREA OF HIGH PRESSURE AT
THE SFC SETTLES OVERHEAD.
THE BROAD 500MB TROUGH WILL EXIT E WEDNESDAY...WITH RIDGING BUILDING
ACROSS THE UPPER GREAT LAKES REGION. THE DRY WEATHER WILL BE SHORT
LIVED AS A SLIGHT CHANCE OF RETURNS OVER LAKE SUPERIOR WEDNESDAY
NIGHT...AS THE 500MB RIDGE BECOMES SUPPRESSED SETTING THE STAGE FOR
NW FLOW ALOFT AND ADDITIONAL DISTURBANCES/UNSETTLED WX THROUGH
THURSDAY NIGHT. THE SFC LOW WELL TO OUR N IN CANADA WILL DRAG A COLD
FRONT NW-SE FROM AROUND 21Z THURSDAY TO 12Z FRIDAY.
DRY WEATHER SHOULD RETURN AGAIN AS THE COLD FRONT SLIPS ACROSS LOWER
MI FRIDAY AND HIGH PRESSURE BUILDS IN FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 150 PM EDT SUN AUG 9 2015
IFR TO MVFR CLOUDS THIS MORNING OVER THE WESTERN U.P. SHOULD LIMIT
THE THUNDER POTENTIAL AT KIWD/KCMX THIS AFTERNOON...BUT THE
NORTHERN EDGE OF A WEAK DISTURBANCE MOVING THROUGH THE AREA THIS
AFTERNOON COULD LEAD TO A STRAY SHOWER AT KIWD. HAVE SEEN CEILINGS
RISING OVER THE LAST TWO HOURS AT THOSE SITES AND THEY SHOULD
TRANSITION TO LOW END VFR THIS AFTERNOON. FARTHER TO THE EAST AT
KSAW...MORE SUNSHINE THIS MORNING HAS STARTED TO PRODUCE A LAKE
BREEZE NEAR MARQUETTE AND EXPECT THAT TO MOVE INLAND. PLANNING ON
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THAT BREEZE AND THIS
AFTERNOON AND PRODUCE A THUNDERSTORM AT KSAW. DID INCLUDE A TWO
HOUR PERIOD DURING GREATEST CONFIDENCE...AND COULD SEE CONDITIONS
FALL TO MVFR OR EVEN IFR DURING THE THUNDERSTORM.
ONCE THE COLD FRONT MOVES THROUGH THE AREA TONIGHT AND BREAKS IN
THE CLOUDS OCCUR...BELIEVE GROUND FOG WILL DEVELOP AT ALL THREE
SITES. WILL SHOW THE WORST CONDITIONS AT KSAW WITH THE HELP OF RAIN
THIS AFTERNOON AND THE LIGHTEST WINDS. DIDN/T GO TOO LOW OVER THE
WEST SITES...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH
THE NIGHT AND LEAD TO MORE MIXING INTO THE DRIER AIR ALOFT. WILL
NEED TO WATCH THE FOG OVER THE WESTERN LAKE...AS THAT COULD LEAD TO
LOWER CONDITIONS THAN FORECAST FOR KCMX. FINALLY FOR
TOMORROW...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE MONDAY AFTERNOON AND EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
150 PM EDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1050 AM EDT SUN AUG 9 2015
ABUNDANT LOW CLOUDS ARE LOCATED OUT AHEAD OF THE COLD FRONT WHICH
IS STRETCHING FROM THUNDER BAY...ALONG THE WESTERN LAKE SUPERIOR
SHORELINE AND THEN SOUTHWEST INTO CENTRAL MINNESOTA. STARTING TO
HAVE SOME CONCERNS THAT THESE WIDESPREAD AND FAIRLY THICK CLOUDS
WILL HAVE SOME DIFFICULTY BURNING OFF THROUGH THE DAY...WHICH WOULD
LIMIT INSTABILITY AND LIKELY THUNDERSTORM DEVELOPMENT OVER PARTS OF
THE WESTERN U.P.. IN ADDITION...A WEAK SHORTWAVE MOVING EAST
THROUGH CENTRAL MINNESOTA IS PRODUCING LIGHT SHOWERS AND PLENTY OF
MID CLOUDS. THAT WAVE AND ITS ASSOCIATED FEATURES SHOULD MOVE EAST
THROUGH THE UPPER GREAT LAKES REGION THIS AFTERNOON INTO THE
EVENING HOURS. WITH THAT FEATURE MOVING THROUGH...WON/T DEVIATE TOO
MUCH FROM THE GOING FORECAST/POPS AT THIS POINT...BUT MAY NEED TO
FOCUS DEVELOPMENT (POPS) ON THE EASTERN EDGE OF THE CLOUDS AND MORE
INTO THE CENTRAL U.P. WHERE THE INSTABILITY WILL BE GREATEST. THAT
WOULD BE MORE IN LINE WITH THE LATEST HRRR/RAP RUNS...WHICH HAVE THE
RIBBON OF BEST MLCAPE VALUES ALONG THAT DIFFERENTIAL HEATING GRADIENT
(KSAW TO CRYSTAL FALLS).
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT SUN AUG 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A VIGOROUS SHORTWAVE
MOVING ACROSS NRN ONTARIO. SEVERAL OTHER SHORTWAVES ACCOMPANIED BY
SHRA/TSTMS ARE NOTED MOVING ACROSS THE NRN AND CNTRL PLAINS. TAIL
END OF FORCING ASSOCIATED WITH NRN ONTARIO SHORTWAVE OVERTOP 850MB
THETA-E RIDGE HAS BEEN SUPPORTING ISOLD/SCT SHRA/TSTM DEVELOPMENT
OVE WRN UPPER MI SINCE SHORTLY AFTER MIDNIGHT. DESPITE LACK OF
INSTABILITY (MUCAPE NO HIGHER THAN 400J/KG)...A FEW OF THE STORMS
WERE FAIRLY STRONG AND LIKELY PRODUCED AT LEAST PEA-SIZE HAIL. RADAR
ESTIMATED INSTANTANEOUS PCPN RATES HAVE BEEN PRETTY IMPRESSIVE AS
WELL...THOUGH RAINFALL CORES HAVE BEEN VERY SMALL.
00Z MODEL RUNS INCLUDING HOURLY RAP/HRRR RUNS SINCE 00Z INDICATE
ONGOING ISOLD/SCT SHRA/TSTMS WILL PROBABLY PERSIST AND REACH CNTRL
UPPER MI BEFORE DIMINISHING AND PERHAPS ENDING FOR THE MOST PART.
ATTENTION THEN TURNS TO THE AFTN. BUILDING INSTABILITY AND
APPROACHING COLD FRONT WILL SPARK A NEW ROUND OF SHRA/TSTMS WITH
MODELS POINTING TOWARD BARAGA/MARQUETTE/IRON COUNTIES AS THE LIKELY
FOCAL AREA FOR GREATEST COVERAGE OF DEVELOPMENT. NAM CONTINUES TO BE
VERY AGGRESSIVE BUILDING MLCAPES TO OVER 1500J/KG OVER WRN UPPER MI
AND AS HIGH AS NEARLY 2500J/KG. GFS TOPS OUT AROUND 1000J/KG WHILE
RECENT RAP RUNS ONLY TOP OUT NEAR 500J/KG. 21Z SREF INDICATES ABOUT
A 30PCT CHANCE OF MLCAPES INCREASING TO OVER 1000J/KG...SO THE NAM
DEFINITELY LOOKS LIKE A HIGH OUTLIER. A REASONABLE EXPECTATION IS
PROBABLY MLCAPES OF 500-1000J/KG. WITH DEEP LAYER SHEAR TOPPING OUT
AROUND 25KT...SVR RISK APPEARS MINIMAL...UNLESS INSTABILITY BUILDS
HIGHER THAN CURRENTLY EXPECTED. SOME SMALL HAIL WILL BE POSSIBLE
WITH THE STRONGEST STORMS. ALSO...EXPECT BRIEF LOCALLY HVY RAINFALL.
SHRA/TSTMS WILL SHIFT E TONIGHT AND DIMINISH. LIGHT WINDS IN THE
VCNTY OF THE PASSING FRONT ALONG WITH EXPECTED RAINFALL SHOULD
RESULT IN FOG DEVELOPING...ESPECIALLY ACROSS SCNTRL/SE UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 444 AM EDT SUN AUG 9 2015
AT 12Z MONDAY THE APEX OF THE 500MB TROUGH /EXTENDING FROM THE LOW
OVER JAMES BAY/ WILL BE OVERHEAD...WITH SHOWERS EXITING THE E CWA.
A SECONDARY SHORTWAVE SWINGING AROUND THE MAIN TROUGH WILL PUSH IN
FROM THE NW MONDAY NIGHT. WITH LIMITED MOISTURE...DO NOT EXPECT MUCH
IN THE WAY OF PRECIP. MODELS DO SHOW SOME INCREASE IN LOW LEVEL
MOISTURE...BELOW 800MB...WITH THE BEST MOISTURE ASSISTED BY N-NNW
FLOW OVER THE E THIRD OF UPPER MI.
EXPECT A MAINLY N WIND TO REMAIN JUST ABOVE THE SFC THROUGH THE
FIRST HALF OF THE WORK WEEK. 850MB TEMPS OF 8-11C WILL HELP KEEP
AFTERNOON SFC TEMPS IN THE 70S MONDAY-WEDNESDAY. AT THIS POINT
TUESDAY LOOKS TO BE THE COOLEST DAY...WITH A FEW READINGS IN THE
UPPER 60S ALONG LAKE SUPERIOR AS A LARGE AREA OF HIGH PRESSURE AT
THE SFC SETTLES OVERHEAD.
THE BROAD 500MB TROUGH WILL EXIT E WEDNESDAY...WITH RIDGING BUILDING
ACROSS THE UPPER GREAT LAKES REGION. THE DRY WEATHER WILL BE SHORT
LIVED AS A SLIGHT CHANCE OF RETURNS OVER LAKE SUPERIOR WEDNESDAY
NIGHT...AS THE 500MB RIDGE BECOMES SUPPRESSED SETTING THE STAGE FOR
NW FLOW ALOFT AND ADDITIONAL DISTURBANCES/UNSETTLED WX THROUGH
THURSDAY NIGHT. THE SFC LOW WELL TO OUR N IN CANADA WILL DRAG A COLD
FRONT NW-SE FROM AROUND 21Z THURSDAY TO 12Z FRIDAY.
DRY WEATHER SHOULD RETURN AGAIN AS THE COLD FRONT SLIPS ACROSS LOWER
MI FRIDAY AND HIGH PRESSURE BUILDS IN FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 150 PM EDT SUN AUG 9 2015
IFR TO MVFR CLOUDS THIS MORNING OVER THE WESTERN U.P. SHOULD LIMIT
THE THUNDER POTENTIAL AT KIWD/KCMX THIS AFTERNOON...BUT THE
NORTHERN EDGE OF A WEAK DISTURBANCE MOVING THROUGH THE AREA THIS
AFTERNOON COULD LEAD TO A STRAY SHOWER AT KIWD. HAVE SEEN CEILINGS
RISING OVER THE LAST TWO HOURS AT THOSE SITES AND THEY SHOULD
TRANSITION TO LOW END VFR THIS AFTERNOON. FARTHER TO THE EAST AT
KSAW...MORE SUNSHINE THIS MORNING HAS STARTED TO PRODUCE A LAKE
BREEZE NEAR MARQUETTE AND EXPECT THAT TO MOVE INLAND. PLANNING ON
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THAT BREEZE AND THIS
AFTERNOON AND PRODUCE A THUNDERSTORM AT KSAW. DID INCLUDE A TWO
HOUR PERIOD DURING GREATEST CONFIDENCE...AND COULD SEE CONDITIONS
FALL TO MVFR OR EVEN IFR DURING THE THUNDERSTORM.
ONCE THE COLD FRONT MOVES THROUGH THE AREA TONIGHT AND BREAKS IN
THE CLOUDS OCCUR...BELIEVE GROUND FOG WILL DEVELOP AT ALL THREE
SITES. WILL SHOW THE WORST CONDITIONS AT KSAW WITH THE HELP OF RAIN
THIS AFTERNOON AND THE LIGHTEST WINDS. DIDN/T GO TOO LOW OVER THE
WEST SITES...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH
THE NIGHT AND LEAD TO MORE MIXING INTO THE DRIER AIR ALOFT. WILL
NEED TO WATCH THE FOG OVER THE WESTERN LAKE...AS THAT COULD LEAD TO
LOWER CONDITIONS THAN FORECAST FOR KCMX. FINALLY FOR
TOMORROW...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE MONDAY AFTERNOON AND EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT SUN AUG 9 2015
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS AFTN AND TONIGHT WILL
LEAD TO A WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY
A WEAK PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT TODAY THRU
MON. MON NIGHT/TUE...GRADIENT TIGHTENS A BIT AHEAD OF APPROACHING
SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE SUPERIOR WILL
PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE SOME INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...SRF
MARINE...ROLFSON
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1051 AM EDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1050 AM EDT SUN AUG 9 2015
ABUNDANT LOW CLOUDS ARE LOCATED OUT AHEAD OF THE COLD FRONT WHICH
IS STRETCHING FROM THUNDER BAY...ALONG THE WESTERN LAKE SUPERIOR
SHORELINE AND THEN SOUTHWEST INTO CENTRAL MINNESOTA. STARTING TO
HAVE SOME CONCERNS THAT THESE WIDESPREAD AND FAIRLY THICK CLOUDS
WILL HAVE SOME DIFFICULTY BURNING OFF THROUGH THE DAY...WHICH WOULD
LIMIT INSTABILITY AND LIKELY THUNDERSTORM DEVELOPMENT OVER PARTS OF
THE WESTERN U.P.. IN ADDITION...A WEAK SHORTWAVE MOVING EAST
THROUGH CENTRAL MINNESOTA IS PRODUCING LIGHT SHOWERS AND PLENTY OF
MID CLOUDS. THAT WAVE AND ITS ASSOCIATED FEATURES SHOULD MOVE EAST
THROUGH THE UPPER GREAT LAKES REGION THIS AFTERNOON INTO THE
EVENING HOURS. WITH THAT FEATURE MOVING THROUGH...WON/T DEVIATE TOO
MUCH FROM THE GOING FORECAST/POPS AT THIS POINT...BUT MAY NEED TO
FOCUS DEVELOPMENT (POPS) ON THE EASTERN EDGE OF THE CLOUDS AND MORE
INTO THE CENTRAL U.P. WHERE THE INSTABILITY WILL BE GREATEST. THAT
WOULD BE MORE IN LINE WITH THE LATEST HRRR/RAP RUNS...WHICH HAVE THE
RIBBON OF BEST MLCAPE VALUES ALONG THAT DIFFERENTIAL HEATING GRADIENT
(KSAW TO CRYSTAL FALLS). &&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT SUN AUG 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A VIGOROUS SHORTWAVE
MOVING ACROSS NRN ONTARIO. SEVERAL OTHER SHORTWAVES ACCOMPANIED BY
SHRA/TSTMS ARE NOTED MOVING ACROSS THE NRN AND CNTRL PLAINS. TAIL
END OF FORCING ASSOCIATED WITH NRN ONTARIO SHORTWAVE OVERTOP 850MB
THETA-E RIDGE HAS BEEN SUPPORTING ISOLD/SCT SHRA/TSTM DEVELOPMENT
OVE WRN UPPER MI SINCE SHORTLY AFTER MIDNIGHT. DESPITE LACK OF
INSTABILITY (MUCAPE NO HIGHER THAN 400J/KG)...A FEW OF THE STORMS
WERE FAIRLY STRONG AND LIKELY PRODUCED AT LEAST PEA-SIZE HAIL. RADAR
ESTIMATED INSTANTANEOUS PCPN RATES HAVE BEEN PRETTY IMPRESSIVE AS
WELL...THOUGH RAINFALL CORES HAVE BEEN VERY SMALL.
00Z MODEL RUNS INCLUDING HOURLY RAP/HRRR RUNS SINCE 00Z INDICATE
ONGOING ISOLD/SCT SHRA/TSTMS WILL PROBABLY PERSIST AND REACH CNTRL
UPPER MI BEFORE DIMINISHING AND PERHAPS ENDING FOR THE MOST PART.
ATTENTION THEN TURNS TO THE AFTN. BUILDING INSTABILITY AND
APPROACHING COLD FRONT WILL SPARK A NEW ROUND OF SHRA/TSTMS WITH
MODELS POINTING TOWARD BARAGA/MARQUETTE/IRON COUNTIES AS THE LIKELY
FOCAL AREA FOR GREATEST COVERAGE OF DEVELOPMENT. NAM CONTINUES TO BE
VERY AGGRESSIVE BUILDING MLCAPES TO OVER 1500J/KG OVER WRN UPPER MI
AND AS HIGH AS NEARLY 2500J/KG. GFS TOPS OUT AROUND 1000J/KG WHILE
RECENT RAP RUNS ONLY TOP OUT NEAR 500J/KG. 21Z SREF INDICATES ABOUT
A 30PCT CHANCE OF MLCAPES INCREASING TO OVER 1000J/KG...SO THE NAM
DEFINITELY LOOKS LIKE A HIGH OUTLIER. A REASONABLE EXPECTATION IS
PROBABLY MLCAPES OF 500-1000J/KG. WITH DEEP LAYER SHEAR TOPPING OUT
AROUND 25KT...SVR RISK APPEARS MINIMAL...UNLESS INSTABILITY BUILDS
HIGHER THAN CURRENTLY EXPECTED. SOME SMALL HAIL WILL BE POSSIBLE
WITH THE STRONGEST STORMS. ALSO...EXPECT BRIEF LOCALLY HVY RAINFALL.
SHRA/TSTMS WILL SHIFT E TONIGHT AND DIMINISH. LIGHT WINDS IN THE
VCNTY OF THE PASSING FRONT ALONG WITH EXPECTED RAINFALL SHOULD
RESULT IN FOG DEVELOPING...ESPECIALLY ACROSS SCNTRL/SE UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 444 AM EDT SUN AUG 9 2015
AT 12Z MONDAY THE APEX OF THE 500MB TROUGH /EXTENDING FROM THE LOW
OVER JAMES BAY/ WILL BE OVERHEAD...WITH SHOWERS EXITING THE E CWA.
A SECONDARY SHORTWAVE SWINGING AROUND THE MAIN TROUGH WILL PUSH IN
FROM THE NW MONDAY NIGHT. WITH LIMITED MOISTURE...DO NOT EXPECT MUCH
IN THE WAY OF PRECIP. MODELS DO SHOW SOME INCREASE IN LOW LEVEL
MOISTURE...BELOW 800MB...WITH THE BEST MOISTURE ASSISTED BY N-NNW
FLOW OVER THE E THIRD OF UPPER MI.
EXPECT A MAINLY N WIND TO REMAIN JUST ABOVE THE SFC THROUGH THE
FIRST HALF OF THE WORK WEEK. 850MB TEMPS OF 8-11C WILL HELP KEEP
AFTERNOON SFC TEMPS IN THE 70S MONDAY-WEDNESDAY. AT THIS POINT
TUESDAY LOOKS TO BE THE COOLEST DAY...WITH A FEW READINGS IN THE
UPPER 60S ALONG LAKE SUPERIOR AS A LARGE AREA OF HIGH PRESSURE AT
THE SFC SETTLES OVERHEAD.
THE BROAD 500MB TROUGH WILL EXIT E WEDNESDAY...WITH RIDGING BUILDING
ACROSS THE UPPER GREAT LAKES REGION. THE DRY WEATHER WILL BE SHORT
LIVED AS A SLIGHT CHANCE OF RETURNS OVER LAKE SUPERIOR WEDNESDAY
NIGHT...AS THE 500MB RIDGE BECOMES SUPPRESSED SETTING THE STAGE FOR
NW FLOW ALOFT AND ADDITIONAL DISTURBANCES/UNSETTLED WX THROUGH
THURSDAY NIGHT. THE SFC LOW WELL TO OUR N IN CANADA WILL DRAG A COLD
FRONT NW-SE FROM AROUND 21Z THURSDAY TO 12Z FRIDAY.
DRY WEATHER SHOULD RETURN AGAIN AS THE COLD FRONT SLIPS ACROSS LOWER
MI FRIDAY AND HIGH PRESSURE BUILDS IN FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 752 AM EDT SUN AUG 9 2015
SHOWERS OVERNIGHT HAVE AIDED DEVELOPMENT OF MVFR CONDITIONS AT KIWD.
IT MAY NOT BE UNTIL AFTN THAT CONDITIONS IMPROVE TO VFR. AT KSAW...
FOG/STRATUS AND LIFR CONDITIONS ARE IMPROVING. MAY SEE LIFR
CONDITIONS AT TIMES FOR THE NEXT HR OR SO. OTHERWISE....VFR
CONDTIONS SHOULD BE THE RULE AT KIWD/KCMX/KSAW TODAY. SHRA/TSTMS
WILL LIKELY DEVELOP DURING THE AFTN AS A COLD FRONT APPROACHES. WITH
KSAW HAVING THE BEST CHC OF SEEING PCPN...SHRA AND VCTS HAVE BEEN
INCLUDED IN FCST LATE THIS AFTN/EVENING. IF ANY TERMINALS SEE
PCPN...IT`S NOT OUT OF THE QUESTION THAT THERE COULD BE BRIEF IFR
CONDITIONS. OTHERWISE...VFR CONDITIONS SHOULD CONTINUE TONIGHT
KIWD/KCMX. PROVIDED THAT IT DOES RAIN...FOG/IFR CONDITIONS ARE
EXPECTED AT KSAW OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT SUN AUG 9 2015
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS AFTN AND TONIGHT WILL
LEAD TO A WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY
A WEAK PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT TODAY THRU
MON. MON NIGHT/TUE...GRADIENT TIGHTENS A BIT AHEAD OF APPROACHING
SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE SUPERIOR WILL
PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE SOME INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
753 AM EDT SUN AUG 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT SUN AUG 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A VIGOROUS SHORTWAVE
MOVING ACROSS NRN ONTARIO. SEVERAL OTHER SHORTWAVES ACCOMPANIED BY
SHRA/TSTMS ARE NOTED MOVING ACROSS THE NRN AND CNTRL PLAINS. TAIL
END OF FORCING ASSOCIATED WITH NRN ONTARIO SHORTWAVE OVERTOP 850MB
THETA-E RIDGE HAS BEEN SUPPORTING ISOLD/SCT SHRA/TSTM DEVELOPMENT
OVE WRN UPPER MI SINCE SHORTLY AFTER MIDNIGHT. DESPITE LACK OF
INSTABILITY (MUCAPE NO HIGHER THAN 400J/KG)...A FEW OF THE STORMS
WERE FAIRLY STRONG AND LIKELY PRODUCED AT LEAST PEA-SIZE HAIL. RADAR
ESTIMATED INSTANTANEOUS PCPN RATES HAVE BEEN PRETTY IMPRESSIVE AS
WELL...THOUGH RAINFALL CORES HAVE BEEN VERY SMALL.
00Z MODEL RUNS INCLUDING HOURLY RAP/HRRR RUNS SINCE 00Z INDICATE
ONGOING ISOLD/SCT SHRA/TSTMS WILL PROBABLY PERSIST AND REACH CNTRL
UPPER MI BEFORE DIMINISHING AND PERHAPS ENDING FOR THE MOST PART.
ATTENTION THEN TURNS TO THE AFTN. BUILDING INSTABILITY AND
APPROACHING COLD FRONT WILL SPARK A NEW ROUND OF SHRA/TSTMS WITH
MODELS POINTING TOWARD BARAGA/MARQUETTE/IRON COUNTIES AS THE LIKELY
FOCAL AREA FOR GREATEST COVERAGE OF DEVELOPMENT. NAM CONTINUES TO BE
VERY AGGRESSIVE BUILDING MLCAPES TO OVER 1500J/KG OVER WRN UPPER MI
AND AS HIGH AS NEARLY 2500J/KG. GFS TOPS OUT AROUND 1000J/KG WHILE
RECENT RAP RUNS ONLY TOP OUT NEAR 500J/KG. 21Z SREF INDICATES ABOUT
A 30PCT CHANCE OF MLCAPES INCREASING TO OVER 1000J/KG...SO THE NAM
DEFINITELY LOOKS LIKE A HIGH OUTLIER. A REASONABLE EXPECTATION IS
PROBABLY MLCAPES OF 500-1000J/KG. WITH DEEP LAYER SHEAR TOPPING OUT
AROUND 25KT...SVR RISK APPEARS MINIMAL...UNLESS INSTABILITY BUILDS
HIGHER THAN CURRENTLY EXPECTED. SOME SMALL HAIL WILL BE POSSIBLE
WITH THE STRONGEST STORMS. ALSO...EXPECT BRIEF LOCALLY HVY RAINFALL.
SHRA/TSTMS WILL SHIFT E TONIGHT AND DIMINISH. LIGHT WINDS IN THE
VCNTY OF THE PASSING FRONT ALONG WITH EXPECTED RAINFALL SHOULD
RESULT IN FOG DEVELOPING...ESPECIALLY ACROSS SCNTRL/SE UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 444 AM EDT SUN AUG 9 2015
AT 12Z MONDAY THE APEX OF THE 500MB TROUGH /EXTENDING FROM THE LOW
OVER JAMES BAY/ WILL BE OVERHEAD...WITH SHOWERS EXITING THE E CWA.
A SECONDARY SHORTWAVE SWINGING AROUND THE MAIN TROUGH WILL PUSH IN
FROM THE NW MONDAY NIGHT. WITH LIMITED MOISTURE...DO NOT EXPECT MUCH
IN THE WAY OF PRECIP. MODELS DO SHOW SOME INCREASE IN LOW LEVEL
MOISTURE...BELOW 800MB...WITH THE BEST MOISTURE ASSISTED BY N-NNW
FLOW OVER THE E THIRD OF UPPER MI.
EXPECT A MAINLY N WIND TO REMAIN JUST ABOVE THE SFC THROUGH THE
FIRST HALF OF THE WORK WEEK. 850MB TEMPS OF 8-11C WILL HELP KEEP
AFTERNOON SFC TEMPS IN THE 70S MONDAY-WEDNESDAY. AT THIS POINT
TUESDAY LOOKS TO BE THE COOLEST DAY...WITH A FEW READINGS IN THE
UPPER 60S ALONG LAKE SUPERIOR AS A LARGE AREA OF HIGH PRESSURE AT
THE SFC SETTLES OVERHEAD.
THE BROAD 500MB TROUGH WILL EXIT E WEDNESDAY...WITH RIDGING BUILDING
ACROSS THE UPPER GREAT LAKES REGION. THE DRY WEATHER WILL BE SHORT
LIVED AS A SLIGHT CHANCE OF RETURNS OVER LAKE SUPERIOR WEDNESDAY
NIGHT...AS THE 500MB RIDGE BECOMES SUPPRESSED SETTING THE STAGE FOR
NW FLOW ALOFT AND ADDITIONAL DISTURBANCES/UNSETTLED WX THROUGH
THURSDAY NIGHT. THE SFC LOW WELL TO OUR N IN CANADA WILL DRAG A COLD
FRONT NW-SE FROM AROUND 21Z THURSDAY TO 12Z FRIDAY.
DRY WEATHER SHOULD RETURN AGAIN AS THE COLD FRONT SLIPS ACROSS LOWER
MI FRIDAY AND HIGH PRESSURE BUILDS IN FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 752 AM EDT SUN AUG 9 2015
SHOWERS OVERNIGHT HAVE AIDED DEVELOPMENT OF MVFR CONDITIONS AT KIWD.
IT MAY NOT BE UNTIL AFTN THAT CONDITIONS IMPROVE TO VFR. AT KSAW...
FOG/STRATUS AND LIFR CONDITIONS ARE IMPROVING. MAY SEE LIFR
CONDITIONS AT TIMES FOR THE NEXT HR OR SO. OTHERWISE....VFR
CONDTIONS SHOULD BE THE RULE AT KIWD/KCMX/KSAW TODAY. SHRA/TSTMS
WILL LIKELY DEVELOP DURING THE AFTN AS A COLD FRONT APPROACHES. WITH
KSAW HAVING THE BEST CHC OF SEEING PCPN...SHRA AND VCTS HAVE BEEN
INCLUDED IN FCST LATE THIS AFTN/EVENING. IF ANY TERMINALS SEE
PCPN...IT`S NOT OUT OF THE QUESTION THAT THERE COULD BE BRIEF IFR
CONDITIONS. OTHERWISE...VFR CONDITIONS SHOULD CONTINUE TONIGHT
KIWD/KCMX. PROVIDED THAT IT DOES RAIN...FOG/IFR CONDITIONS ARE
EXPECTED AT KSAW OVERNIGHT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT SUN AUG 9 2015
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS AFTN AND TONIGHT WILL
LEAD TO A WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY
A WEAK PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT TODAY THRU
MON. MON NIGHT/TUE...GRADIENT TIGHTENS A BIT AHEAD OF APPROACHING
SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE SUPERIOR WILL
PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE SOME INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
532 AM EDT SUN AUG 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 532 AM EDT SUN AUG 9 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A VIGOROUS SHORTWAVE
MOVING ACROSS NRN ONTARIO. SEVERAL OTHER SHORTWAVES ACCOMPANIED BY
SHRA/TSTMS ARE NOTED MOVING ACROSS THE NRN AND CNTRL PLAINS. TAIL
END OF FORCING ASSOCIATED WITH NRN ONTARIO SHORTWAVE OVERTOP 850MB
THETA-E RIDGE HAS BEEN SUPPORTING ISOLD/SCT SHRA/TSTM DEVELOPMENT
OVE WRN UPPER MI SINCE SHORTLY AFTER MIDNIGHT. DESPITE LACK OF
INSTABILITY (MUCAPE NO HIGHER THAN 400J/KG)...A FEW OF THE STORMS
WERE FAIRLY STRONG AND LIKELY PRODUCED AT LEAST PEA-SIZE HAIL. RADAR
ESTIMATED INSTANTANEOUS PCPN RATES HAVE BEEN PRETTY IMPRESSIVE AS
WELL...THOUGH RAINFALL CORES HAVE BEEN VERY SMALL.
00Z MODEL RUNS INCLUDING HOURLY RAP/HRRR RUNS SINCE 00Z INDICATE
ONGOING ISOLD/SCT SHRA/TSTMS WILL PROBABLY PERSIST AND REACH CNTRL
UPPER MI BEFORE DIMINISHING AND PERHAPS ENDING FOR THE MOST PART.
ATTENTION THEN TURNS TO THE AFTN. BUILDING INSTABILITY AND
APPROACHING COLD FRONT WILL SPARK A NEW ROUND OF SHRA/TSTMS WITH
MODELS POINTING TOWARD BARAGA/MARQUETTE/IRON COUNTIES AS THE LIKELY
FOCAL AREA FOR GREATEST COVERAGE OF DEVELOPMENT. NAM CONTINUES TO BE
VERY AGGRESSIVE BUILDING MLCAPES TO OVER 1500J/KG OVER WRN UPPER MI
AND AS HIGH AS NEARLY 2500J/KG. GFS TOPS OUT AROUND 1000J/KG WHILE
RECENT RAP RUNS ONLY TOP OUT NEAR 500J/KG. 21Z SREF INDICATES ABOUT
A 30PCT CHANCE OF MLCAPES INCREASING TO OVER 1000J/KG...SO THE NAM
DEFINITELY LOOKS LIKE A HIGH OUTLIER. A REASONABLE EXPECTATION IS
PROBABLY MLCAPES OF 500-1000J/KG. WITH DEEP LAYER SHEAR TOPPING OUT
AROUND 25KT...SVR RISK APPEARS MINIMAL...UNLESS INSTABILITY BUILDS
HIGHER THAN CURRENTLY EXPECTED. SOME SMALL HAIL WILL BE POSSIBLE
WITH THE STRONGEST STORMS. ALSO...EXPECT BRIEF LOCALLY HVY RAINFALL.
SHRA/TSTMS WILL SHIFT E TONIGHT AND DIMINISH. LIGHT WINDS IN THE
VCNTY OF THE PASSING FRONT ALONG WITH EXPECTED RAINFALL SHOULD
RESULT IN FOG DEVELOPING...ESPECIALLY ACROSS SCNTRL/SE UPPER MI.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 444 AM EDT SUN AUG 9 2015
AT 12Z MONDAY THE APEX OF THE 500MB TROUGH /EXTENDING FROM THE LOW
OVER JAMES BAY/ WILL BE OVERHEAD...WITH SHOWERS EXITING THE E CWA.
A SECONDARY SHORTWAVE SWINGING AROUND THE MAIN TROUGH WILL PUSH IN
FROM THE NW MONDAY NIGHT. WITH LIMITED MOISTURE...DO NOT EXPECT MUCH
IN THE WAY OF PRECIP. MODELS DO SHOW SOME INCREASE IN LOW LEVEL
MOISTURE...BELOW 800MB...WITH THE BEST MOISTURE ASSISTED BY N-NNW
FLOW OVER THE E THIRD OF UPPER MI.
EXPECT A MAINLY N WIND TO REMAIN JUST ABOVE THE SFC THROUGH THE
FIRST HALF OF THE WORK WEEK. 850MB TEMPS OF 8-11C WILL HELP KEEP
AFTERNOON SFC TEMPS IN THE 70S MONDAY-WEDNESDAY. AT THIS POINT
TUESDAY LOOKS TO BE THE COOLEST DAY...WITH A FEW READINGS IN THE
UPPER 60S ALONG LAKE SUPERIOR AS A LARGE AREA OF HIGH PRESSURE AT
THE SFC SETTLES OVERHEAD.
THE BROAD 500MB TROUGH WILL EXIT E WEDNESDAY...WITH RIDGING BUILDING
ACROSS THE UPPER GREAT LAKES REGION. THE DRY WEATHER WILL BE SHORT
LIVED AS A SLIGHT CHANCE OF RETURNS OVER LAKE SUPERIOR WEDNESDAY
NIGHT...AS THE 500MB RIDGE BECOMES SUPPRESSED SETTING THE STAGE FOR
NW FLOW ALOFT AND ADDITIONAL DISTURBANCES/UNSETTLED WX THROUGH
THURSDAY NIGHT. THE SFC LOW WELL TO OUR N IN CANADA WILL DRAG A COLD
FRONT NW-SE FROM AROUND 21Z THURSDAY TO 12Z FRIDAY.
DRY WEATHER SHOULD RETURN AGAIN AS THE COLD FRONT SLIPS ACROSS LOWER
MI FRIDAY AND HIGH PRESSURE BUILDS IN FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 126 AM EDT SUN AUG 9 2015
MVFR VSBYS ARE POSSIBLE THRU THE EARLY MORNING HRS AT KSAW...
ALTHOUGH THE LIKELIHOOD OF IFR OR LOWER CONDITIONS HAVE DECREASED DUE
TO THE MID LEVEL CLOUDS ACROSS THE AREA FROM THE THUNDERSTORMS ACROSS
MN. THERE IS A POSSIBILITY OF A STRAY SHOWER OR STORM AT KIWD AND
KCMX LATE IN THE NIGHT...BUT DRY AIR ACROSS THE AREA WILL LIKELY
KEEP ANY STORMS WEST OF THE AREA UNTIL LATE MORNING/AFTN AS THE COLD
FRONT PASSES THROUGH. THE BEST CHANCE OF SHOWERS AND STORMS WOULD BE
AT KSAW THIS AFTERNOON...BUT AT THIS TIME WILL KEEP OUT OF THE
TERMINAL FORECAST OTHER THAN VCSH. BEHIND THE FRONT...WINDS WILL TURN
WESTERLY AND THE SHOWER ACTIVITY WILL END. SOME INDICATIONS OF IFR
VSBYS TONIGHT INTO MONDAY MORNING...BUT THIS WILL LIKELY DEPEND OF
HOW MUCH RAIN WE GET TODAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 532 AM EDT SUN AUG 9 2015
COLD FRONT MOVING ACROSS LAKE SUPERIOR THIS AFTN AND TONIGHT WILL
LEAD TO A WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY
A WEAK PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT TODAY THRU
MON. MON NIGHT/TUE...GRADIENT TIGHTENS A BIT AHEAD OF APPROACHING
SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE SUPERIOR WILL
PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE SOME INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...MRD
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
445 AM EDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM EDT SAT AUG 8 2015
THE UPPER GREAT LAKES REGION WILL BE BETWEEN UPPER LEVEL FEATURES
OVER THE NEXT 24 HOURS...LEADING TO SOME UNCERTAINTY IN THE COVERAGE
AND AMOUNT OF PRECIPITATION THAT WILL OCCUR AHEAD OF THE COLD FRONT
TONIGHT. THE MAIN SHORTWAVE IS CURRENTLY LOCATED JUST TO THE EAST OF
LAKE WINNIPEG AND HAS A 1002MB SURFACE LOW LOCATED WITH IT. A COLD
FRONT STRETCHES SOUTH-SOUTHEAST FROM THIS LOW AND INTO NORTHERN
MINNESOTA (CURRENTLY FROM THE LAKE OF THE WOODS TO JUST TO THE EAST
OF FARGO). HAVE SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AROUND
PARK RAPIDS MINNESOTA A COUPLE HOURS AGO AND THEY HAVE BEEN MAKING
THERE WAY TO THE EAST TOWARDS LEECH LAKE AHEAD OF THAT FRONT AND IN
THE RIBBON OF DEEPER MOISTURE FROM 925-700MB AHEAD OF THE ASSOCIATED
TROUGH. OVER THE U.P....THE ABUNDANT DRY AIR SEEN ABOVE 700MB ON THE
12Z KGRB SOUNDING AND ON RAP ANALYSIS DATA...ASSOCIATED WITH THE
SURFACE RIDGE FROM A HIGH NEAR JAMES BAY...HAS BEEN LIMITING THE
EASTWARD EXTENT OF THE OF SHOWERS AS THEY MOVE INTO WESTERN LAKE
SUPERIOR. BUT WITH THE MOISTURE BELOW 700MB...HAVE SEEN DIURNAL CU
FILL IN THE GAPS FROM EARLIER TODAY BETWEEN THE SOUTHEASTERLY FLOW
UPSLOPE FOG AND LOW CLOUDS. TEMPERATURES HAVE WARMED INTO THE 70S
ACROSS THE AREA...WITH THE WARMEST VALUES OVER THE EAST WITH MORE
SUNSHINE. FINALLY FARTHER TO THE SOUTH...A SHORTWAVE ROUNDING THE
UPPER RIDGE OVER TEXAS/OKLAHOMA LED TO AN MCS MOVING THROUGH
NORTHEAST KANSAS AND SOUTHWEST MISSOURI EARLY THIS MORNING AND IT
HAS SINCE DISSIPATED. BUT WITH ANOTHER WAVE ROUNDING THE RIDGE
THROUGH NEBRASKA...WOULD EXPECT REDEVELOPMENT TO THE EAST OF THAT
AREA OVER THE NEXT COUPLE OF HOURS.
WITH THE SOUTHERN SHORTWAVE STAYING WELL TO THE SOUTH OF THE
AREA...THE MAIN FOCUS WILL BE WITH THE UPPER LOW NEAR LAKE WINNIPEG
SLOWLY WEAKENING AS IT MOVES EAST TOWARDS JAMES BAY. THIS WILL LEAD
TO THE SURFACE LOW FOLLOWING SUIT AND SLOWLY DRAGGING THE COLD FRONT
EAST ACROSS THE CWA. HAVE ALREADY SEEN SHOWERS/THUNDERSTORMS DEVELOP
IN NORTHERN MINNESOTA AHEAD OF THE FRONT AND WITH THE STORM MOTION
VALUES INDICATING EASTWARD MOVEMENT UP TO 30KTS...WOULD EXPECT THE
SHOWERS TO SPREAD EAST INTO WESTERN LAKE SUPERIOR AND EVENTUALLY THE
WESTERN U.P. TONIGHT. LIKE LAST NIGHT AND TODAY...THEY WILL BE
BATTLING THE EXISTING DRY MID LEVEL AIR AS THEY MOVE OUT AHEAD OF
THE SLOW MOVING SURFACE-850MB TROUGH...SO WOULD EXPECT SOME
DIMINISHMENT AS THEY HEAD TO THE EAST AND INTO THE CWA TONIGHT.
WOULD EXPECT SOME MARGINALLY SEVERE STORMS TO MOVE INTO WESTERN LAKE
SUPERIOR BEFORE THE DRY AIR AND LOSS OF DIURNAL HEATING STARTS TO
TAKE ITS TOLL. OVER THE CENTRAL AND EASTERN U.P....AM EXPECTED SOME
PATCHY GROUND FOG TO DEVELOP TONIGHT. THICKNESS WILL DEPEND ON THE
AMOUNT OF DECOUPLING THAT OCCURS TONIGHT. HAVE SHOWN THE THICKEST
FOG (AREAS COVERAGE) OVER THE CENTRAL U.P. FOR SOUTHERN
MARQUETTE...DICKINSON...DELTA...AND NORTHERN MENOMINEE COUNTIES.
WITH THE COLD FRONT STILL OFF TO THE WEST OF THE U.P. ON SUNDAY
MORNING...EXPECT THERE TO BE TIME FOR DIURNAL HEATING TO INCREASE
THE POTENTIAL FOR SHOWERS/THUNDERSTORMS OVER THE WEST/CENTRAL U.P.
DURING THE AFTERNOON. MODELS HAVE A VARIETY OF IDEAS ON ML CAPE
VALUES...RANGING FROM 250-2000 J/KG TOMORROW AFTERNOON JUST AHEAD OF
THE FRONT. LOOKING AT MODIFIED SOUNDINGS AND MEAN ML CAPE VALUES
FROM THE NCAR ENSEMBLES AND SREF...FEEL THAT VALUES AROUND 500-750
J/KG ARE A FAIRLY REASONABLE EXPECTATION AT THIS POINT. WITH 0-6KM
BULK SHEAR VALUES GENERALLY AROUND 25-30KTS...THERE IS THE POTENTIAL
FOR AN ISOLATED STRONGER STORM TOMORROW AFTERNOON. THAT MATCHES THE
IDEA FROM UPDRAFT VELOCITY/HELICITY FROM THE CAM/S AND CAM
ENSEMBLES. WITH WET BULB ZERO VALUES NEARING 10KFT AND FREEZING
LEVEL ABOVE 12KFT...THINK THAT WILL COMBINE WITH THE MARGINAL SHEAR
TO KEEP THE HAIL THREAT BORDERLINE. LIKED THE PREVIOUS SHIFTS
HANDLING OF THE DEVELOPMENT OF THE SHOWERS/THUNDERSTORMS ACROSS THE
CENTRAL U.P. (RAMPING UP TO LOCALIZED LIKELY VALUES OVER MARQUETTE
COUNTY) AND HAVE ONLY MADE MINOR ADJUSTMENTS BASED OFF LATEST MODEL
TRENDS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 444 AM EDT SUN AUG 9 2015
AT 12Z MONDAY THE APEX OF THE 500MB TROUGH /EXTENDING FROM THE LOW
OVER JAMES BAY/ WILL BE OVERHEAD...WITH SHOWERS EXITING THE E CWA.
A SECONDARY SHORTWAVE SWINGING AROUND THE MAIN TROUGH WILL PUSH IN
FROM THE NW MONDAY NIGHT. WITH LIMITED MOISTURE...DO NOT EXPECT MUCH
IN THE WAY OF PRECIP. MODELS DO SHOW SOME INCREASE IN LOW LEVEL
MOISTURE...BELOW 800MB...WITH THE BEST MOISTURE ASSISTED BY N-NNW
FLOW OVER THE E THIRD OF UPPER MI.
EXPECT A MAINLY N WIND TO REMAIN JUST ABOVE THE SFC THROUGH THE
FIRST HALF OF THE WORK WEEK. 850MB TEMPS OF 8-11C WILL HELP KEEP
AFTERNOON SFC TEMPS IN THE 70S MONDAY-WEDNESDAY. AT THIS POINT
TUESDAY LOOKS TO BE THE COOLEST DAY...WITH A FEW READINGS IN THE
UPPER 60S ALONG LAKE SUPERIOR AS A LARGE AREA OF HIGH PRESSURE AT
THE SFC SETTLES OVERHEAD.
THE BROAD 500MB TROUGH WILL EXIT E WEDNESDAY...WITH RIDGING BUILDING
ACROSS THE UPPER GREAT LAKES REGION. THE DRY WEATHER WILL BE SHORT
LIVED AS A SLIGHT CHANCE OF RETURNS OVER LAKE SUPERIOR WEDNESDAY
NIGHT...AS THE 500MB RIDGE BECOMES SUPPRESSED SETTING THE STAGE FOR
NW FLOW ALOFT AND ADDITIONAL DISTURBANCES/UNSETTLED WX THROUGH
THURSDAY NIGHT. THE SFC LOW WELL TO OUR N IN CANADA WILL DRAG A COLD
FRONT NW-SE FROM AROUND 21Z THURSDAY TO 12Z FRIDAY.
DRY WEATHER SHOULD RETURN AGAIN AS THE COLD FRONT SLIPS ACROSS LOWER
MI FRIDAY AND HIGH PRESSURE BUILDS IN FOR THE START OF THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 126 AM EDT SUN AUG 9 2015
MVFR VSBYS ARE POSSIBLE THRU THE EARLY MORNING HRS AT KSAW...
ALTHOUGH THE LIKELIHOOD OF IFR OR LOWER CONDITIONS HAVE DECREASED DUE
TO THE MID LEVEL CLOUDS ACROSS THE AREA FROM THE THUNDERSTORMS ACROSS
MN. THERE IS A POSSIBILITY OF A STRAY SHOWER OR STORM AT KIWD AND
KCMX LATE IN THE NIGHT...BUT DRY AIR ACROSS THE AREA WILL LIKELY
KEEP ANY STORMS WEST OF THE AREA UNTIL LATE MORNING/AFTN AS THE COLD
FRONT PASSES THROUGH. THE BEST CHANCE OF SHOWERS AND STORMS WOULD BE
AT KSAW THIS AFTERNOON...BUT AT THIS TIME WILL KEEP OUT OF THE
TERMINAL FORECAST OTHER THAN VCSH. BEHIND THE FRONT...WINDS WILL TURN
WESTERLY AND THE SHOWER ACTIVITY WILL END. SOME INDICATIONS OF IFR
VSBYS TONIGHT INTO MONDAY MORNING...BUT THIS WILL LIKELY DEPEND OF
HOW MUCH RAIN WE GET TODAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 250 PM EDT SAT AUG 8 2015
A LOW MOVING FROM JUST EAST OF LAKE WINNIPEG TO JAMES BAY THIS
WEEKEND WILL SWEEP A SURFACE TROUGH ACROSS LAKE SUPERIOR ON
SUNDAY...LEADING TO A SHIFT IN THE WINDS FROM A LIGHT SOUTH TO
SOUTHEASTERLY DIRECTION TO THE NORTHWEST BY MONDAY. WITH A
GENERALLY LIGHT PRESSURE GRADIENT IN PLACE...EXPECT WINDS TO STAY
BELOW 20KTS THROUGH THE PERIOD...ESPECIALLY AFTER TUESDAY WHEN HIGH
PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THE MIDDLE OF
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...MRD
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
129 AM EDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 250 PM EDT SAT AUG 8 2015
THE UPPER GREAT LAKES REGION WILL BE BETWEEN UPPER LEVEL FEATURES
OVER THE NEXT 24 HOURS...LEADING TO SOME UNCERTAINTY IN THE COVERAGE
AND AMOUNT OF PRECIPITATION THAT WILL OCCUR AHEAD OF THE COLD FRONT
TONIGHT. THE MAIN SHORTWAVE IS CURRENTLY LOCATED JUST TO THE EAST OF
LAKE WINNIPEG AND HAS A 1002MB SURFACE LOW LOCATED WITH IT. A COLD
FRONT STRETCHES SOUTH-SOUTHEAST FROM THIS LOW AND INTO NORTHERN
MINNESOTA (CURRENTLY FROM THE LAKE OF THE WOODS TO JUST TO THE EAST
OF FARGO). HAVE SEEN SOME SHOWERS AND THUNDERSTORMS DEVELOP AROUND
PARK RAPIDS MINNESOTA A COUPLE HOURS AGO AND THEY HAVE BEEN MAKING
THERE WAY TO THE EAST TOWARDS LEECH LAKE AHEAD OF THAT FRONT AND IN
THE RIBBON OF DEEPER MOISTURE FROM 925-700MB AHEAD OF THE ASSOCIATED
TROUGH. OVER THE U.P....THE ABUNDANT DRY AIR SEEN ABOVE 700MB ON THE
12Z KGRB SOUNDING AND ON RAP ANALYSIS DATA...ASSOCIATED WITH THE
SURFACE RIDGE FROM A HIGH NEAR JAMES BAY...HAS BEEN LIMITING THE
EASTWARD EXTENT OF THE OF SHOWERS AS THEY MOVE INTO WESTERN LAKE
SUPERIOR. BUT WITH THE MOISTURE BELOW 700MB...HAVE SEEN DIURNAL CU
FILL IN THE GAPS FROM EARLIER TODAY BETWEEN THE SOUTHEASTERLY FLOW
UPSLOPE FOG AND LOW CLOUDS. TEMPERATURES HAVE WARMED INTO THE 70S
ACROSS THE AREA...WITH THE WARMEST VALUES OVER THE EAST WITH MORE
SUNSHINE. FINALLY FARTHER TO THE SOUTH...A SHORTWAVE ROUNDING THE
UPPER RIDGE OVER TEXAS/OKLAHOMA LED TO AN MCS MOVING THROUGH
NORTHEAST KANSAS AND SOUTHWEST MISSOURI EARLY THIS MORNING AND IT
HAS SINCE DISSIPATED. BUT WITH ANOTHER WAVE ROUNDING THE RIDGE
THROUGH NEBRASKA...WOULD EXPECT REDEVELOPMENT TO THE EAST OF THAT
AREA OVER THE NEXT COUPLE OF HOURS.
WITH THE SOUTHERN SHORTWAVE STAYING WELL TO THE SOUTH OF THE
AREA...THE MAIN FOCUS WILL BE WITH THE UPPER LOW NEAR LAKE WINNIPEG
SLOWLY WEAKENING AS IT MOVES EAST TOWARDS JAMES BAY. THIS WILL LEAD
TO THE SURFACE LOW FOLLOWING SUIT AND SLOWLY DRAGGING THE COLD FRONT
EAST ACROSS THE CWA. HAVE ALREADY SEEN SHOWERS/THUNDERSTORMS DEVELOP
IN NORTHERN MINNESOTA AHEAD OF THE FRONT AND WITH THE STORM MOTION
VALUES INDICATING EASTWARD MOVEMENT UP TO 30KTS...WOULD EXPECT THE
SHOWERS TO SPREAD EAST INTO WESTERN LAKE SUPERIOR AND EVENTUALLY THE
WESTERN U.P. TONIGHT. LIKE LAST NIGHT AND TODAY...THEY WILL BE
BATTLING THE EXISTING DRY MID LEVEL AIR AS THEY MOVE OUT AHEAD OF
THE SLOW MOVING SURFACE-850MB TROUGH...SO WOULD EXPECT SOME
DIMINISHMENT AS THEY HEAD TO THE EAST AND INTO THE CWA TONIGHT.
WOULD EXPECT SOME MARGINALLY SEVERE STORMS TO MOVE INTO WESTERN LAKE
SUPERIOR BEFORE THE DRY AIR AND LOSS OF DIURNAL HEATING STARTS TO
TAKE ITS TOLL. OVER THE CENTRAL AND EASTERN U.P....AM EXPECTED SOME
PATCHY GROUND FOG TO DEVELOP TONIGHT. THICKNESS WILL DEPEND ON THE
AMOUNT OF DECOUPLING THAT OCCURS TONIGHT. HAVE SHOWN THE THICKEST
FOG (AREAS COVERAGE) OVER THE CENTRAL U.P. FOR SOUTHERN
MARQUETTE...DICKINSON...DELTA...AND NORTHERN MENOMINEE COUNTIES.
WITH THE COLD FRONT STILL OFF TO THE WEST OF THE U.P. ON SUNDAY
MORNING...EXPECT THERE TO BE TIME FOR DIURNAL HEATING TO INCREASE
THE POTENTIAL FOR SHOWERS/THUNDERSTORMS OVER THE WEST/CENTRAL U.P.
DURING THE AFTERNOON. MODELS HAVE A VARIETY OF IDEAS ON ML CAPE
VALUES...RANGING FROM 250-2000 J/KG TOMORROW AFTERNOON JUST AHEAD OF
THE FRONT. LOOKING AT MODIFIED SOUNDINGS AND MEAN ML CAPE VALUES
FROM THE NCAR ENSEMBLES AND SREF...FEEL THAT VALUES AROUND 500-750
J/KG ARE A FAIRLY REASONABLE EXPECTATION AT THIS POINT. WITH 0-6KM
BULK SHEAR VALUES GENERALLY AROUND 25-30KTS...THERE IS THE POTENTIAL
FOR AN ISOLATED STRONGER STORM TOMORROW AFTERNOON. THAT MATCHES THE
IDEA FROM UPDRAFT VELOCITY/HELICITY FROM THE CAM/S AND CAM
ENSEMBLES. WITH WET BULB ZERO VALUES NEARING 10KFT AND FREEZING
LEVEL ABOVE 12KFT...THINK THAT WILL COMBINE WITH THE MARGINAL SHEAR
TO KEEP THE HAIL THREAT BORDERLINE. LIKED THE PREVIOUS SHIFTS
HANDLING OF THE DEVELOPMENT OF THE SHOWERS/THUNDERSTORMS ACROSS THE
CENTRAL U.P. (RAMPING UP TO LOCALIZED LIKELY VALUES OVER MARQUETTE
COUNTY) AND HAVE ONLY MADE MINOR ADJUSTMENTS BASED OFF LATEST MODEL
TRENDS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM EDT SAT AUG 8 2015
AFTER ANY LINGERING SHOWERS END ON MON FOLLOWING A SUN NGT COLD
FROPA...THE NW FLOW BTWN A BLDG UPR RDG IN THE PLAINS AND AN
AMPLIFYING TROF OVER ERN NAMERICA WL BE THE DOMINATING INFLUENCE ON
UPR MI WX EARLY IN THE WEEK. THE RESULT WL BE A RETURN OF DRY AND
COOLER WX FOR THE MOST PART MON INTO WED. THE NEXT CHC OF SHOWERS/TS
WL ARRIVE WITH WARMER AIR WED NGT THRU THU NGT AHEAD OF A SHRTWV
MOVING OVER THE TOP OF THE RDG/THRU NW ONTARIO AND ITS ATTENDANT
COLD FNT. HI PRES TRAILING THIS COLD FNT SHOULD BRING A SEASONABLE
AIRMASS/DRIER WX LATE IN THE WEEK.
SUN NGT...SHRTWV DRIFTING ESEWD THRU FAR NORTHERN ONTARIO WL REACH
NEAR JAMES BAY BY 12Z MON AND DRAG ATTENDANT COLD FNT SLOWLY THRU
THE UPR LKS. SINCE THE SHARPER DYNAMIC FORCING ASSOCIATED WITH THE
ONTARIO SHRTWV WL BE REMAIN TO THE N AND H85 THETA E ADVECTION/
DEEPER MSTR INFLOW WL BE WEAK AT BEST...EXPECT NO MORE THAN A CHC OF
SHOWERS/TS. THE BEST CHC FOR THIS PCPN WL BE IN THE EVNG OVER
CENTRAL UPR MI...WHERE AXIS OF SOMEWHAT HIER H85 THETA E WL BE
PRESENT AT TIME WHEN DAYTIME HEATING WL STILL BE A FACTOR. THE
MAJORITY OF THE MODELS SHOW A TRAILING SHRTWV/AREA OF HIER MID LVL
MSTR/SOME DPVA AND H7-3 QVECTOR CNVGC APRCHG FM CENTRAL MN FOLLOWING
THE COLD FROPA. HOWEVER...NOCTURNAL COOLING AND LLVL DRYING/
NEGATIVE H85 THETA E ADVCTN WL LIMIT THE COVERAGE/INTENSITY OF ANY
SHOWERS THAT MIGHT ACCOMPANYING THIS HIER LVL FORCING. EXPECT THE
LOWEST MIN TEMPS OVER THE W...WHERE H85 TEMPS ARE FCST TO FALL TO
ARND 11C BY DAYBREAK.
MON...EXPECT ANY LINGERING SHOWERS OVER THE E AND SCENTRAL TO
DIMINISH WITH ARRIVAL OF DEEP DRYING/INCRSG LLVL ACYC NNW FLOW AHEAD
OF CNDN HI PRES BLDG INTO MANITOBA. LINGERING MID CLDS WL GIVE WAY
TO SOME DIURNAL CU/SC IN THE AFTN. EXPECT HI TEMPS MAINLY IN THE 70S
TO NEAR 80 OVER THE SCNTRL WITH H85 TEMPS IN THE 12-14C RANGE.
LOCATIONS NEAR LK SUP WL BE COOLEST WITH A NW FLOW OFF THE WATER.
MON NGT THRU TUE NGT...ARRIVAL OF MORE VIGOROUS DEEP LYR QVECTOR
DVGC/SUBSIDENCE UNDER CONFLUENT NW FLOW ALOFT BTWN PLAINS RDG/ERN
TROF AND H85 TEMPS FALLING AS LO AS 8 TO 10C IN THE LLVL NLY FLOW
AHEAD OF CNDN HI PRES BLDG TOWARD THE UPR LKS WL RESULT IN A PERIOD
OF COOLER AND DRIER WX FOR THE CWA. SOME OF THE MODELS HAVE BEEN
GENERATING SOME LGT PCPN MAINLY DURING DAYTIME HEATING ON TUE
ACCOMPANYING THE PASSAGE OF A SHRTWV IN THE NW FLOW. BUT ABSENCE OF
ANY MSTR INFLOW...LARGER SCALE NEGATIVE DYNAMIC FORCING/SUBSIDENCE
THAT WL MAINTAIN MID LVL CAPPING SHOWN ON THE GFS FCST SDNGS AS WELL
AS DIFFLUENT LLVL FLOW WARRANTS MAINTAINING GOING DRY FCST FOR NOW.
BUT THERE WL BE A GOOD DEAL OF DIURNAL CU ON TUE UNDER INCOMING H85
THERMAL TROF. EXPECT LO TEMPS ON TUE NGT TO FALL INTO THE 40S AT THE
COOLER INTERIOR LOCATIONS WITH MOCLR SKIES/LIGHT WINDS AS THE SFC HI
PRES MOVES OVHD.
WED...AS THE HI CENTER DRIFTS TO THE S...THE LLVL FLOW WL TURN TO
THE WSW. THE WARMING RELATED TO SOME WAA AND CONTINUED SUBSIDENCE
UNDER THE SLOWLY EXPANDING PLAINS RDG/RISING HGTS IS FCST TO BOOST
H85 TEMPS TO ARND 16C OVER THE W LATE IN THE DAY. EXPECT A WARMER
DAY THAN ON TUE...WITH HI TEMPS AT LEAST APRCHG 80 ESPECIALLY OVER
THE W AWAY FM LK MODERATION...EVEN IF SOME WAA CLDS SPILL OVER THE
CWA IN THE AFTN.
WED NGT THRU THU NGT...ALTHOUGH THERE ARE SOME DIFFERENCES IN THE
DETAILS AS EXPECTED SO FAR INTO THE FUTURE...THE LONGER RANGE
GUIDANCE INDICATES A SHRTWV RIDING OVER THE PLAINS RDG WL DROP SEWD
THRU NW ONTARIO ON THU/THU NGT AND DRAG A COLD FNT THRU THE UPR LKS
ON THU NGT. SOME OF THE MODELS GENERATE SOME LGT PCPN AS EARLY AS
WED NGT IN THE WSW FLOW/WAA BTWN THE RETREATING HI PRES TO THE S AND
FALLING MSLP OVER SCENTRAL CANADA AHEAD OF THE SHRTWV. BUT LINGERING
LLVL ACYC FLOW AND RELATIVE DRYNESS OF AIRMASS INDICATE ANY SHOWERS
WL BE WIDELY SCT AT BEST. A BETTER CHC FOR SHOWERS/TS APPEARS WL
COME LATE THU/THU EVNG WITH THE ARRIVAL OF SOME DEEP LYR QVECTOR
CNVGC ASSOCIATED WITH THE ONTARIO SHRTWV AND AHEAD OF APRCHG COLD
FNT DURING PERIOD OF DAYTIME HEATING. THE 12Z GFS IS MOST VIGOROUS
WITH THIS DISTURBANCE AND INDICATES THE POTENTIAL FOR SOME SVR
STORMS WITH MUCAPE FCST AS HI AS 2500 J/KG AND DEEP LYR SHEAR UP TO
40 KTS. THE 12Z ECMWF/CNDN MODELS SHOW A LESS IMPRESSIVE SCENARIO
WITH WEAKER MSTR RETURN. GIVEN MODEL DIFFERENCES AND UNCERTAINTY ON
THE DEGREE OF MSTR RETURN WITH SHARPEST FORCING REMAINING TO THE
NE...CONSENSUS LO CHC POPS AT THIS POINT SEEM REASONABLE. THU LOOKS
TO BE THE WARMEST DAY OF THE WEEK UNDER THERMAL RDG/H85 TEMPS UP TO
18-20C AHEAD OF INCOMING COLD FNT.
FRI/SAT...HI PRES TRAILING THE SHRTWV SHOULD BRING DRY AND SOMEWHAT
COOLER WX AT LEAST ON FRI/FRI NGT. THERE IS SOME UNCERTAINTY ON HOW
QUICKLY WAA SHOWERS/TS RETURN BTWN THE RETREATING HI AND ANOTHER
SHRTWV RIDING OVER THE PLAINS RDG LATER ON SAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 126 AM EDT SUN AUG 9 2015
MVFR VSBYS ARE POSSIBLE THRU THE EARLY MORNING HRS AT KSAW...
ALTHOUGH THE LIKELIHOOD OF IFR OR LOWER CONDITIONS HAVE DECREASED DUE
TO THE MID LEVEL CLOUDS ACROSS THE AREA FROM THE THUNDERSTORMS ACROSS
MN. THERE IS A POSSIBILITY OF A STRAY SHOWER OR STORM AT KIWD AND
KCMX LATE IN THE NIGHT...BUT DRY AIR ACROSS THE AREA WILL LIKELY
KEEP ANY STORMS WEST OF THE AREA UNTIL LATE MORNING/AFTN AS THE COLD
FRONT PASSES THROUGH. THE BEST CHANCE OF SHOWERS AND STORMS WOULD BE
AT KSAW THIS AFTERNOON...BUT AT THIS TIME WILL KEEP OUT OF THE
TERMINAL FORECAST OTHER THAN VCSH. BEHIND THE FRONT...WINDS WILL TURN
WESTERLY AND THE SHOWER ACTIVITY WILL END. SOME INDICATIONS OF IFR
VSBYS TONIGHT INTO MONDAY MORNING...BUT THIS WILL LIKELY DEPEND OF
HOW MUCH RAIN WE GET TODAY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 250 PM EDT SAT AUG 8 2015
A LOW MOVING FROM JUST EAST OF LAKE WINNIPEG TO JAMES BAY THIS
WEEKEND WILL SWEEP A SURFACE TROUGH ACROSS LAKE SUPERIOR ON
SUNDAY...LEADING TO A SHIFT IN THE WINDS FROM A LIGHT SOUTH TO
SOUTHEASTERLY DIRECTION TO THE NORTHWEST BY MONDAY. WITH A
GENERALLY LIGHT PRESSURE GRADIENT IN PLACE...EXPECT WINDS TO STAY
BELOW 20KTS THROUGH THE PERIOD...ESPECIALLY AFTER TUESDAY WHEN HIGH
PRESSURE WILL SETTLE OVER THE GREAT LAKES REGION FOR THE MIDDLE OF
NEXT WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...MRD
MARINE...SRF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
605 PM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT MON AUG 10 2015
THE FORECAST CHALLENGES WILL BE ANY SPOTTY PRECIPITATION AND
PATCHY FOG...OTHERWISE...MAINLY QUIET AND SEASONABLE WEATHER WITH
SURFACE HIGH PRESSURE OVER THE AREA FOR THE NEXT COUPLE OF DAYS.
ON THIS MORNING/S UPPER AIR MAPS...AN H3 JET WAS STRETCHED ACROSS
NEBRASKA. THE H5 RIDGE WAS OVER THE ROCKIES WITH A CLOSED LOW OFF
THE WEST COAST AND A SHORTWAVE TROF OVER SOUTHERN MINNESOTA INTO
SOUTH DAKOTA. THE BEST H7 DEWPOINTS WERE POOLED TO THE SOUTH FROM
THE TEXAS PANHANDLE INTO OKLAHOMA AND PARTS OF SOUTHERN COLORADO AND
NEW MEXICO AND MEXICO. 14-16 DEGREE H85 DEWPOINTS STRETCHED IN THIS
SAME AREA...BUT ALSO EXTENDED INTO KANSAS...WITH A 13 DEGREE H85
DEWPOINT LINGERING AT OAX.
THE HRRR AND HIRESW ARW/NMM HAVE SOME SPOTTY PRECIP PRIOR TO
00Z...AND THE HRRR LINGERS IT INTO THE EVENING...WHILE THE NAM/GFS
ARE MOSTLY DRY. CONVECTIVE TEMPERATURES ARE IN THE LOWER 80S...
THUS WILL CONTINUE TO MONITOR CU FIELDS FOR ANY SPOTTY POP UP
SHOWERS. THE DMX RADAR HAS A FEW SHOWERS WITH THE SHORTWAVE
PASSING THROUGH SOUTHERN IOWA. DRIER DEWPOINTS HAD MOVED INTO
EASTERN NEBRASKA...HOWEVER SOME HIGHER 14 DEG DEWPOINTS WERE STILL
IN WESTERN IOWA ALONG WITH SOME MOISTURE CONVERGENCE IN THIS AREA.
THE BEST MLCAPES PER THE SPC MESOANALYSIS WAS OVER KANSAS AND
MISSOURI WITH 500 J/KG MLCAPES OVER EASTERN NEBRASKA/WESTERN IOWA.
WITH THE WET GROUND IN SPOTS AND LIGHT WINDS TONIGHT...SOME HINTS
OF PATCHY FOG IN LOW LYING AREAS/RIVER VALLEYS WITH 1 TO 2 DEGREE
DEWPOINT DEPRESSIONS.
THE NAM HAS SOME SPOTTY PRECIP AGAIN TUESDAY EVENING MAINLY JUST
WEST OF THE FORECAST AREA AND TOWARD HARLAN WITH CONVECTION THAT
FORMS WITH THE INCREASING LOW LEVEL JET IN THE HIGH PLAINS/THETA-E
ADVECTION. THE GFS IS GENERALLY DRY THROUGH THURSDAY. WILL
MAINTAIN A MAINLY DRY FORECAST THROUGH THE SHORT TERM UNTIL THERE
IS BETTER AGREEMENT ON SUBTLE FORCING FEATURES FOR PLACEMENT OF
ANY ISOLATED PRECIPITATION.
LOWS TONIGHT SHOULD DROP BACK INTO THE 50S TO LOWER 60S TUESDAY
MORNING. HIGHS SHOULD BE IN THE 80S TUESDAY AND WEDNESDAY WITH
WARMER 80S TO LOWER 90S THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON AUG 10 2015
A RIDGE OF HIGH PRESSURE ALOFT WILL KEEP TEMPERATURES ABOVE NORMAL
IN THE UPPER 80S TO LOWER 90S FRIDAY AND SATURDAY. THE RIDGE
BREAKS DOWN FOR THE WEEKEND INTO EARLY NEXT WEEK AS A COLD FRONT
SLIPS INTO THE AREA AND STALLS. FOR NOW...DO HAVE A CHANCE FOR
THUNDERSTORMS WITH THE FRONT SATURDAY NIGHT INTO MONDAY. THERE ARE
SOME TIMING DIFFERENCES WITH THE EC BEING SLOWER.
&&
.AVIATION...(00Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 604 PM CDT MON AUG 10 2015
NORTHERLY WINDS WILL CONTINUE TO DECREASE THIS EVENING. THE
COMBINATION OF MOISTURE AT THE SURFACE AND LIGHT WINDS COULD CREATE
SOME PATCHY FOG AT KOFK AND KOMA EARLY TUESDAY MORNING. OTHERWISE
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KG
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
336 PM CDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
CHANCE FOR THUNDERSTORMS AND THEIR SEVERITY TONIGHT ARE THE PRIMARY
FORECAST CONCERNS.
THUNDERSTORMS WERE FIRING AT MID AFTERNOON ALONG A WEAK SURFACE
BOUNDARY STRETCHING FROM SOUTHEAST SOUTH DAKOTA INTO WESTERN
NEBRASKA. THESE STORMS HAVE PLENTY OF INSTABILITY AND SHEAR TO FEED
ON...SOME 2500 J/KG OF MLCAPE AND 40KT OF EFFECTIVE BULK SHEAR...AS
PER LATEST RAP OBJECTIVE ANALYSIS. ALREADY GETTING REPORTS OF SEVERE
HAIL JUST WEST OF OUR AREA WHERE VIGOROUS UPDRAFTS WERE SEEN. AND
FREEZING LEVELS ARE QUITE A BIT LOWER THAN LAST EVENING. SO A
CONTINUED HAIL THREAT IS CERTAINLY EXPECTED...WITH MODEST MICROBURST
POTENTIAL ALSO NOTED ON RAP PROGS.
PERHAPS A BIGGER SHOW WITH POTENTIALLY MORE WIDESPREAD SEVERE LATER
THIS EVENING IS POSSIBLE. MID LEVEL SHORTWAVE DIVING INTO WESTERN
SOUTH DAKOTA WILL CONTINUE SOUTHEAST THIS EVENING...PUSHING A COLD
FRONT ALONG WITH IT. SHEAR PROFILES SHOULD ACTUALLY INCREASE IN
MAGNITUDE GIVEN MID LEVEL SPEED MAX TIED TO WAVE. SHEAR VECTORS ARE
LINING UP NEARLY PARALLEL WITH EXPECTED FRONTAL/CONVECTIVE
LINE...SUPPORTING MORE OF A LINEAR STORM MODE. WIND
FIELDS...PREDICTED DOWNDRAFT CAPE AND LAYER THETA-E DIFFERENCES
APPROACHING 30 ALL SUGGEST SEVERE WIND POTENTIAL AS LINE RACES INTO
EASTERN NEBRASKA. SEVERAL MESOSCALE HI-RES MODELS ARE OFFERING
VARIED OPINIONS AROUND THIS LINE OF THINKING...SO WILL HIT EVENING
THUNDER CHANCES PRETTY HARD. EXPECT STORMS TO SLOWLY DIE OFF LATER
THIS EVENING AND OVERNIGHT AS THEY APPROACH INTERSTATE 80 AND
BEYOND...HOWEVER SEVERE THREAT APPEARS TO LINGER FOR SOME TIME AFTER
DARK.
BY MONDAY MORNING LINGERING STORMS SHOULD BE EXITING OUR
SOUTHEAST CWA. HOWEVER WEAK IMPULSE IN MID LEVEL FLOW COULD TAP
WANING INSTABILITY IN THE MID AFTERNOON TO PRODUCE A STORM OR TWO
IN SOUTHWEST IOWA. THEN NORTHERLY SURFACE FLOW UNDER HIGH PRESSURE
WILL FORETELL A RELATIVELY DRY PERIOD OVER THE NEXT COUPLE OF
DAYS.
HIGHS BOTH TUESDAY AND WEDNESDAY WILL GRADUALLY INCREASE INTO THE
LOWER AND MIDDLE 80S UNDER PLENTY OF SUNSHINE. AND DEW POINTS SHOULD
BE LOWER ON TUESDAY BEFORE BEGINNING TO RETURN WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
OUR RELATIVELY QUIET WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH
THE REST OF THE WEEK. MID LEVEL HIGH PRESSURE RIDGE IS FORECAST BY
BOTH ECMWF AND GFS TO BUILD FROM THE SOUTHERN PLAINS INTO THE
NORTHERN ROCKIES...AND EXPAND A BIT TO THE EAST. THIS WILL TAKE MAIN
STORM TRACK NORTH AND EAST OF OUR AREA...AND ALLOW FOR WARMER
TEMPERATURES BOTH AT THE SURFACE AND ALOFT. WILL MAINTAIN OUR DRY
FORECAST UNTIL MAYBE SATURDAY NIGHT OR SUNDAY WHEN RIDGE IS FORECAST
TO BEGIN TO BREAK DOWN. HIGHS MAINLY IN THE UPPER 80S AND LOWER 90S
SHOULD PREVAIL.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1246 PM CDT SUN AUG 9 2015
ALL THREE TAF SITES HAVE IMPROVED TO MVFR WITH REGARD TO CEILINGS
AND VISIBILITY. THIS IMPROVEMENT TREND WILL CONTINUE THROUGH THE
EARLY HOURS OF THIS FORECAST CYCLE WITH MVFR BKN/OVC CIGS BECOMING
SCT. A COLD FRONT WILL APPROACH NORTHEAST NEBRASKA AFTER 00Z WHICH
WILL BRING THE NEXT ROUND OF THUNDERSTORMS. HAVE THUNDER IN ALL
THREE TAF SITES AFTER 03Z...STARTING THE EARLIEST AT KOFK. SOME
QUESTION AS TO TIMING SO WILL ADJUST AS NEEDED ONCE CONVECTION
INITIATES. THUNDERSTORMS SHOULD BE CLEAR OF THE FORECAST AREA
AFTER 12Z BUT HAVE LINGERING MVFR CIGS BEHIND THE COLD FRONT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...MEYER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
328 AM CDT SUN AUG 9 2015
.SYNOPSIS...
ISSUED AT 328 AM CDT SUN AUG 9 2015
AN AREA OF SHOWERS AND THUNDERSTORMS CONTINUES TO MOVE FROM CENTRAL
INTO EASTERN SOUTH DAKOTA ASSOCIATED NEAR A WEAK FRONTAL BOUNDARY
EXTENDING FROM SRN MINN THROUGH CENTRAL SOUTH DAKOTA INTO THE
WESTERN NEBR PNHDL. ANOTHER AREA OF THUNDERSTORMS REMAINS ANCHORED
ON THE CUSP OF A WARM FRONT FROM ECTRL NEBR INTO SWRN IA.
DEWPOINTS IN WRN NEBR RANGING IN THE MID TO UPPER 60S. PATCHY FOG
EXISTS FROM CENTRAL INTO NERN NEBR.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SUN AUG 9 2015
NEAR TERM CONCERN IS THE DEVELOPMENT OF PATCHY FOG UNTIL MID
MORNING. MODELS ARE IN FAIR AGREEMENT FOR FOG TO CONTINUE EXPANDING
WESTWARD INTO THE SERN PNHDL AND SWRN NEBR. SKIES LOOK TO BE PARTLY
SUNNY TODAY...WITH ANY STRATUS FROM EARLY MORNING FOG TO BURN OFF BY
10AM CDT. FCST HIGHS TODAY TO RANGE MAINLY FROM 86 TO 90 DEGREES
WITH A DOWNSLOPING WESTERLY WINDS HELPING TO MIX DOWN H85 TEMPS OF
23 TO 27C. SHOWERS AND THUNDERSTORMS ARE FORECAST TO DEVELOP THIS
AFTERNOON IN NCTRL NEBR SOUTHWARD ACROSS THE ERN HALF OF THE FA.
WHILE MID LEVEL LAPSE RATES ARE ONLY 6.5 TO 7C/KM...SBCAPES WILL
INCREASE TO 1500 TO 2000 J/KG EAST OF AN ANW THROUGH NORTH PLATTE
LINE. THE STRONGEST DEEP LAYER SHEAR WILL BE IN NERN FA RANGING FROM
40 TO 50 KTS SUPPORTIVE OF A FEW SEVERE STORMS. AREA FOR BEST STORM
DEVELOPMENT WILL BE FROM SCTRL SD INTO THE ERN HALF OF NCTRL NEBR.
ISOLATED DEVELOPMENT POSSIBLE FURTHER SOUTHWEST INTO LINCOLN AND
FRONTIER COUNTY.
STORM INITIATION THIS AFTERNOON WILL KEEP CHCS THIS EVENING ACROSS
THE ERN HALF OF FA EXITING FAR ERN ZONES AFTER 06Z. A FEW SEVERE
STORMS POSSIBLE THIS EVENING EAST OF VALENTINE THROUGH BURWELL WITH
A FEW STRONG STORMS POSSIBLE SOUTHWEST OF THIS LINE TO AROUND THE
NORTH PLATTE AREA.
UPPER RIDGING IS FORECAST ACROSS THE CNTRL AND NRN ROCKIES AS A
CLOSED LOW MOVES OVER THE HUDSON BAY REGION. SURFACE HIGH PRESSURE
WILL BUILD ACROSS THE NRN INTO THE CNTRL PLAINS OVERNIGHT. LOWS IN
WRN NEBR SLIGHTLY COOLER THAN RECENT NIGHTS RANGING FROM THE UPPER
50S TO LOWER 60S MOST AREAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 328 AM CDT SUN AUG 9 2015
MODEL GUIDANCE REMAINS IN GOOD AGREEMENT WITH THE AMPLIFICATION OF
A UPPER LEVEL RIDGE ACROSS THE INTERMOUNTAIN WEST EARLY NEXT WEEK.
THIS WILL FAVOR A GENERAL NORTHWEST STEERING FLOW ACROSS THE HIGH
PLAINS AND ADJACENT SANDHILLS THROUGH THE ENTIRE WORK WEEK. WHILE
THE FORECAST AREA REMAINS ON THE EASTERN PERIPHERY OF THE BUILDING
RIDGE AND PLENTIFUL LOWER TROPOSPHERIC MOISTURE WILL BE IN
PLACE...PRECIPITATION CHANCE WILL BE MAINLY TIED TO THE HIGHER
TERRAIN OFF TO OUR WEST. PRECIPITATION CHANCES ARE NOT NIL HOWEVER
AS THE OCCASIONAL PASSAGE OF A WEAK PERTURBATION MAY BE SUFFICIENT
TO GENERATE/MAINTAIN AN ISOLATED THUNDERSTORM. ONE SUCH
OPPORTUNITY ARRIVES LATE MONDAY OR EARLY ON TUESDAY...BUT THE
TREND OF THE MODELS CONTINUES TO CONFINE THE CHANCES ONLY ACROSS
OUR FAR SOUTHWEST. OTHERWISE THE NEXT NOTABLE SHOT A QPF ARRIVES
LATE WEEK WHEN A SHORTWAVE BREAKSDOWN THE UPPER RIDGE AND FORCES A
COLD FRONT ACROSS THE PLAINS.
POST FRONTAL CONDITIONS WILL PROMOTE A SLIGHT COOL DOWN ON
MONDAY...BUT THEREAFTER DAYTIME TEMPERATURES ARE FORECAST TO
GRADUALLY INCREASE AS HIGH PRESSURE BUILDS TO THE SOUTHWEST OF THE
FORECAST AREA AND INCREASING THERMAL ADVECTION SPREADS EAST FROM
THE ROCKIES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1125 PM CDT SAT AUG 8 2015
THE NAM AND RAP MODELS SUGGEST AREAS OF FOG WILL FORM OVERNIGHT.
THE FORECAST USES THE NAM BUT NOTE THE RAP SHOWS THE FOG FORMING
FARTHER WEST ALONG HIGHWAY 61 WHILE THE NAM KEEPS THE FOG CLOSER
TO HIGHWAY 83.
VFR IS EXPECTED ALL AREAS BY 15Z SUNDAY. ISOLATED TO SCATTERED
TSTM COVERAGE IS EXPECTED LATE SUNDAY AFTN AND EARLY SUNDAY
EVENING ALONG AND EAST OF HIGHWAY 183.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROBERG
SHORT TERM...ROBERG
LONG TERM...JACOBS
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1210 AM CDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CDT SAT AUG 8 2015
NO BIG CHANGES FROM PREVIOUS THINKING...MAIN CONCERN IS POTENTIAL
FOR SEVERE WEATHER AND HEAVY RAIN. THE SEVERE THREAT WOULD MAINLY
BE PRIOR TO 06Z TONIGHT AND THEN ALSO LATE SUN AFTN/SUN EVENING.
HEAVY RAIN THREAT IS PRIOR TO ABOUT 08Z TONIGHT...AND MAINLY IN
SWRN IA.
JET PATTERN AT 12Z SHOWED 300 MB WINDS OF 50 TO 80 KNOTS FROM SRN
CA INTO SD/ND/MN. A 500 MB LOW WAS OVER SRN ID AT 12Z BUT WATER
VAPOR IMAGERY/RECENT RUC MODEL INITIALIZATIONS SHOWED IT HAD
MOVED TO NEAR THE ID/MT/WY BORDER AREA AS OF EARLY THIS AFTN. THIS
WILL CONTINUE TO TRACK SLOWLY NEWD/EWD TONIGHT. THE 19Z KOAX
SOUNDING SHOWED THAT THE MID LEVELS HAD WARMED A BIT SINCE 12Z.
OUR 12Z 700 MB TEMP WAS 7.6 C BUT HAD INCREASED TO 10.7 C AS OF
19Z. 19Z SPC MESOANALYSIS SHOWED THAT THERE WAS STILL QUITE A BIT
OF LOWEST 100 MB CONVECTIVE INHIBITION (MLCIN) AND MOST OF THE
AREA WAS NOT OVERLY UNSTABLE. HIGHEST MLCAPE WAS NEAR THE KS
BORDER... AROUND 2000 J/KG. CAP WAS WEAKEST FROM SWRN KS INTO
PARTS OF CNTRL KS AS OF MID AFTN...NEAR AND AHEAD OF SFC LOW PRES
CENTER.
THERE REMAINS A CONDITIONAL THREAT OF SEVERE WEATHER FOR MOST OF
THE AREA. 0-6 KM SHEAR IS EXPECTED TO BE ADEQUATE FOR ROTATING
STORMS...BUT THERE IS SOME UNCERTAINTY AS TO WHEN AND WHERE
STRONG/SEVERE STORMS MAY FORM. THE MODELS OFFER VARYING SOLUTIONS.
ONE THING WE SAY IS THAT IT DOES APPEAR THAT BEST FOCUS WILL
SHIFT TO IA AND NRN MO LATER TONIGHT WITH A 30-50 KNOT LOW LEVEL
JET. LOWS SHOULD RANGE FROM MID 60S N TO AROUND 70 S.
WILL KEEP STORM CHANCES OVERNIGHT AND SUNDAY MORNING FOR AT LEAST
PARTS OF THE FCST AREA. BETTER POTENTIAL THOUGH APPEARS TO BE
LATER IN THE DAY ACRS OUR NRN ZONES...AS A FRONTAL SYSTEM DROPS
INTO THE AREA. KEPT SOME LOW POPS FOR LATE SUNDAY NIGHT AND MONDAY
BUT NOT IMPRESSED WITH RAIN POTENTIAL IN THOSE PERIODS FOR NOW...
ESPECIALLY MONDAY WHEN SURFACE RIDGE AXIS WILL BE BUILDING DOWN
ACROSS THE REGION.
.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 315 PM CDT SAT AUG 8 2015
PCPN CHANCES LOOK TO BE 14 PERCENT OR LESS FROM MONDAY NIGHT
ONWARD...SO FCST TEXT WILL NOT HAVE ANY MENTION OF TSTMS IN THOSE
PERIODS. 500 MB RIDGE IS EXPECTED TO BUILD W AND N FROM OK AND TX
MUCH OF THE WEEK...THEN FLATTEN A BIT BY NEXT WEEKEND AS TROUGH
MOVES EAST FROM THE PACIFIC NW AND NRN ROCKIES. LEFT A BLEND OF
GFS AND ECMWF TEMPS IN THE EXTENDED PERIOD...BUT HIGHS MAY END UP
BEING A BIT WARMER THAN THAT.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1207 AM CDT SUN AUG 9 2015
THUNDERSTORMS IN THE VICINITY OF KLNK/KOMA COULD LINGER FOR A
COUPLE HOURS AT TAF ISSUANCE. STORMS WILL DEFINITELY AFFECT
KOMA...BUT COULD VERY WELL MISS KLNK. KOFK REMAINS DRY. SOME MVFR
FOG COULD DEVELOP LATER TONIGHT AT ALL TAF SITES...AND COULD
TEMPORARILY BE IFR AT KOFK FOR A PERIOD. ADDITIONAL STORMS WILL BE
POSSIBLE AT KOFK VERY LATE IN THE TAF PERIOD...AFTER 10/02Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...MILLER
LONG TERM...MILLER
AVIATION...DEWALD
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1126 PM CDT SAT AUG 8 2015
.SYNOPSIS...
ISSUED AT 333 PM CDT SAT AUG 8 2015
UA ANALYSIS FROM THIS MORNING HAD A FAIRLY ACTIVE
PATTERN ACROSS THE WESTERN HALF OF THE CONUS AND SRN CANADA. CLOSED
LOWS WERE NOTED OVER MANITOBA...AND OFF THE COAST OF BRITISH
COLUMBIA. ACROSS THE INTERMOUNTAIN WEST...SHORTWAVES WERE NOTED OVER
SRN IDAHO AND OVER CENTRAL CALIFORNIA. A WEAK SHORTWAVE WAS LOCATED
OVER SERN SD AND HAS SINCE PUSHED INTO SRN MN BASED ON WV IMAGERY.
ABUNDANT MID AND HIGH CLOUDINESS HAS STREAMED INTO THE FORECAST AREA
TDY FROM THE FOUR CORNERS IN ASSOCIATION WITH MONSOONAL MOISTURE
FROM MEXICO. THIS HIGH CLOUDINESS HAS ALLOWED LOW CLOUDINESS LEFT
OVER FROM THIS MORNING TO PERSIST INTO THE AFTERNOON HRS. THIS HAS
LED TO COOL TEMPS THIS AFTERNOON WITH READINGS MAINLY IN THE 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 333 PM CDT SAT AUG 8 2015
VERY LIGHT WINDS EXPECTED TONIGHT ACROSS THE AREA...AND WITH THE WET
GROUND FROM RECENT RAINFALL...APPEARS TO BE A FAVORABLE SET UP FOR
AT LEAST PATCHY FOG OVERNIGHT. OTHERWISE...A STRONG SHORTWAVE ALOFT
IS CURRENTLY MOVING INTO SOUTHWEST MONTANA. EXPECT THE BEST FORCING
ASSOCIATED WITH THIS WAVE TO STAY NORTH AND WEST OF THE REGION
TONIGHT...BUT CANNOT RULE OUT A STRAY THUNDERSTORM ACROSS NORTHWEST
NEBRASKA IN CLOSER PROXIMITY TO THE SHORTWAVE.
THE WAVE ALOFT WILL WEAKEN SOME SUNDAY AS IT TURNS EAST AND MOVES
INTO THE DAKOTAS. A WEAK COLD FRONT/SURFACE TROUGH WILL TRY AND
ADVANCE EAST ACROSS THE AREA AS SURFACE LOW PRESSURE DEEPENS A BIT
IN CENTRAL SOUTH DAKOTA. THIS WILL BE A FOCUS FOR A FEW TSTMS LATE
SUNDAY AFTERNOON...WITH THE BEST CHANCES ACROSS EASTERN PORTIONS OF
NORTH CENTRAL NEBRASKA WHERE SOMEWHAT BETTER UPPER LEVEL FORCING
WILL BE LOCATED. AGREE WITH THE SPC SLIGHT RISK FOR SEVERE STORMS
ACROSS HOLT AND BOYD COUNTIES...AS MLCAPE APPROACHES 1500 TO 2500
J/KG ALONG AND AHEAD OF THE FRONT. AMPLE WIND SHEAR WOULD SUPPORT A
SUPERCELL OR TWO IF STORMS DEVELOP...WITH LARGE HAIL AND DAMAGING
WINDS THE MAIN THREATS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 333 PM CDT SAT AUG 8 2015
MID RANGE...SUNDAY NIGHT THROUGH TUESDAY...IN THE MID
RANGE...PRECIPITATION CHANCES SUNDAY NIGHT...AND MONDAY NIGHT ARE
THE MAIN FORECAST CHALLENGES. FOR SUNDAY NIGHT...A COLD FRONTAL
BOUNDARY WILL PUSH INTO NORTHWESTERN AROUND 00Z MONDAY...THEN
CENTRAL NEBRASKA DURING THE EVENING HOURS...EXITING THE CWA AROUND
THE 06Z MONDAY TIME FRAME. SOUTH OF THE FRONT A DRYLINE WILL EXTEND
FROM ROUGHLY NORTH PLATTE...TO AINSWORTH...WHERE SB CAPES APPROACH
3000 J/KG. DECENT MOISTURE CONVERGENCE ALONG THE DRYLINE...COUPLED
WITH A WEAK CAP WILL LEAD TO THE DEVELOPMENT OF THUNDERSTORMS SUNDAY
EVENING. AS THIS ACTIVITY MIGRATES EAST...ABUNDANT DEEP LAYER SHEAR
OF 40 TO 45 KTS EXISTS EAST OF THE DRYLINE SUNDAY EVENING...WHICH
WOULD SUPPORT STRONG STORMS IN THE CENTRAL AND SOUTH...AND SOME
SEVERE STORMS IN THE NERN CWA...WHERE SHEAR IS STRONGER AND
AVAILABLE CAPE IS GREATER. IN ADDITION...INSTABILITY IN THE MID
LEVELS IS STRONGER IN THE NERN CWA AS IT WILL BE LOCATED IN CLOSER
PROXIMITY TO THE H5 SHORTWAVE. DECIDED TO KEEP IN A MENTION OF
SLIGHT CHANCE POPS ALONG AND EAST OF THE DRYLINE...AND INCREASED
POPS TO 30 TO 40 PERCENT IN THE NORTHEAST WHERE BETTER DYNAMICS AND
INSTABILITY ALOFT EXISTS. THE COLD FRONT WILL DROP SOUTH INTO KANSAS
OVERNIGHT...AND REMAIN OFF TO THE SOUTH OF THE FORECAST AREA FOR
MONDAY AS SURFACE HIGH PRESSURE BUILDS INTO NORTHERN NEBRASKA. THIS
WILL LEAD TO COOLER TEMPS WITH HIGHS AROUND 80 MONDAY. FOR MONDAY
NIGHT...THE GFS AND NAM SOLNS...DO INITIATE CONVECTION ALONG THE
HIGH PLAINS OF COLORADO AND WYOMING MONDAY AFTERNOON...SOME OF WHICH
BEGINS TO APPROACH THE FAR WESTERN AND SWRN CWA LATER IN THE
EVENING. INHERITED FCST HAD PRECIP CHANCES AS FAR EAST AS HIGHWAY
83. BASED ON THE MODEL TRENDS...TRIMMED POPS BACK...CONFINING THEM
TO THE SERN PANHANDLE AND FAR SWRN NEBRASKA. ON TUESDAY...ANOTHER
ROUND OF THUNDERSTORMS WILL DEVELOP ACROSS THE FRONT RANGE AND HIGH
PLAINS OF COLORADO AND WYOMING. HOWEVER...H5 WINDS WILL TURN MORE TO
THE NORTHWEST AS HIGH PRESSURE BEGINS TO BUILD INTO NEW MEXICO AND
COLORADO. WITH NOT MUCH IN THE WAY OF CONVECTION EXPECTED OVER THE
BLACK HILLS...THINKING MOST LEE SIDE CONVECTION TUESDAY SHOULD STAY
WEST OF THE FORECAST AREA AND HAVE OPTED FOR A DRY FCST.
LONG RANGE...TUESDAY NIGHT THROUGH SATURDAY...IN THE
EXTENDED...RIDGING IS STILL ON TRACK TO BUILD INTO THE CENTRAL AND
NORTHERN ROCKIES...AS WELL AS THE HIGH PLAINS BY MIDWEEK. HIGH
PRESSURE AT THE BASE OF THE RIDGE...WILL BUILD NORTH INTO COLORADO
LATE IN THE WEEK. THIS WILL RESULT IN DRY CONDS AND INCREASING
TEMPERATURES ACROSS THE FORECAST AREA. AFTER HIGHS IN THE MID TO
UPPER 80S WEDNESDAY...READINGS WILL REACH THE 90S BY THE LATTER
HALF OF NEXT WEEK. THE RIDGE WILL BEGIN TO FLATTEN ACROSS THE
ROCKIES FRIDAY NIGHT AS A DECENT SHORTWAVE TROUGH TRACKS ACROSS
SRN CANADA. THIS FEATURE WILL FORCE A COLD FRONT ACROSS THE
DAKOTAS SATURDAY...THE SRN FRINGES OF WHICH...WILL APPROACH THE
NWRN CWA. DECIDED TO INTRODUCE SOME POPS IN THE NWRN CWA SATURDAY
TO ACCOUNT FOR THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1125 PM CDT SAT AUG 8 2015
THE NAM AND RAP MODELS SUGGEST AREAS OF FOG WILL FORM OVERNIGHT.
THE FORECAST USES THE NAM BUT NOTE THE RAP SHOWS THE FOG FORMING
FARTHER WEST ALONG HIGHWAY 61 WHILE THE NAM KEEPS THE FOG CLOSER
TO HIGHWAY 83.
VFR IS EXPECTED ALL AREAS BY 15Z SUNDAY. ISOLATED TO SCATTERED
TSTM COVERAGE IS EXPECTED LATE SUNDAY AFTN AND EARLY SUNDAY
EVENING ALONG AND EAST OF HIGHWAY 183.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...TAYLOR
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
318 PM PDT SUN AUG 9 2015
.SYNOPSIS...TEMPERATURES RUNNING SLIGHTLY BELOW NORMAL FOR THIS
TIME OF YEAR. ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
ACROSS NORTHERN NEVADA THIS AFTERNOON. THERE IS A CHANCE FOR
MONSOON MOISTURE MIDWEEK...FOLLOWED BY ANOTHER PACIFIC STORM NEXT
WEEKEND.
&&
.SHORT TERM...TODAY THROUGH TUESDAY. THE HRRR IS PRETTY CONVECTIVE
NORTH OF INTERSTATE 80 THIS AFTERNOON AND INTO THE EVENING...WHICH
GAINS SOME SUPPORT FROM THE LATEST VISIBLE IMAGE ON SATELLITE.
HOWEVER...WITH REGARD TO QPF...THE NAM AND THE HRRR MAY BE OVER
DOING IT A BIT...ALTHOUGH THE PLACEMENT OF THE CONVECTION IS
VERY FEASIBLE. LIGHTNING STRIKES HAVE BEEN OBSERVED OVER PORTIONS
OF ELKO COUNTY NEAR THE IDAHO BORDER. THE HRRR HAS THE CONVECTION
BASICALLY BEING SHUNTED AT 2Z...AND BY 5Z THE LKN CWA IS TSRA
FREE. TOMORROW THE GFS BRINGS A SLUG OF MOISTURE BY 18Z AND THE
NAM HAS NOTHING AT 18Z...AND A FRACTION OF THE QPF SHIELD BY 00Z
WITH AN OFF SET PLACEMENT. THE POPS IN THIS FORECAST PACKAGE
REPRESENTS A CONSALL MODEL BLEND APPROACH...BUT NOT THE BEST
CONFIDENCE. TUESDAY...MORE OF THE SAME CONSALL BLENDING...WITH THE
QPF ON THE EASTERN PORTION OF THE CWA...WHICH ACCOUNTS FOR THE
PROGRESSIVE NATURE OF THE INCOMING PACIFIC LOW.
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY. A NORTHEAST PACIFIC LOW
MOVES ASHORE AND STRUGGLES TO ENTER THE INTERIOR WEST AS IT MOVES
AGAINST THE FOUR CORNERS RIDGE. THIS CREATES MOSTLY DRY FLOW INTO
THE GREAT BASIN...BUT AT TIMES WEAKNESSES IN THE RIDGE-TROUGH
BOUNDARY WILL ALLOW FOR LIMITED MOISTURE INTO THE REGION.
HENCE...PERIODS OF ISOLATED THUNDERSTORMS OF THE HYBRID VARIETY
THROUGH ABOUT FRIDAY. NEXT WEEKEND LOOKS DRY. TEMPS NEAR NORMAL. ONE
THING THOUGH...WINDS INCREASE WEDNESDAY AND THURSDAY WITH LOWER RH
VALUES FOR A POSSIBLE FIRE WEATHER SITUATION. STAY TUNED FOR WHEN
THIS TIME COMES INTO THE SHORT TERM PERIOD.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO KELY AND KTPH
THROUGH MONDAY AFTERNOON. ISOLATED THUNDERSTORMS ARE POSSIBLE OVER
NORTHERN NEVADA EARLY SUNDAY EVENING AND MONDAY AFTERNOON. MOST WILL
STAY CLEAR OF KWMC AND KEKO.
&&
.FIRE WEATHER...VIRGA...ISOLATED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE ACROSS NORTHERN NEVADA THIS AFTERNOON. SO FAR FWZ 470...HAS
GOTTEN THE LIONS SHARE OF THE LIGHTNING AS CONVECTION HAS BEGUN
TO PERCOLATE OVER NORTHERN NV. THERE IS A CHANCE FOR MONSOON
MOISTURE MIDWEEK...FOLLOWED BY A WIND EVENT THURSDAY AND FRIDAY.
THE MODELS ARE FLIPPING A BIT AND NOT HANDLING THE MONSOON SURGE
FOLLOWED BY A ANOTHER PACNW STORM WELL. THIS ASSESSMENT IS BACKED
BY THE NCEP RMOP WHICH IS IN MARKEDLY LESS CONFIDENT TERRITORY BY
F72...WITH REGARD TO THE ENSEMBLE MEAN FORECAST AT 500 MB.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98/97
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
855 AM PDT SUN AUG 9 2015
.SYNOPSIS...LIMITED MOISTURE HAS BEEN PULLED UP INTO NORTHWEST
ARIZONA AND SOUTHEAST NEVADA TODAY WHICH WILL LEAD TO ISOLATED
SHOWERS OR THUNDERSTORMS. DRY CONDITIONS CAN BE EXPECTED ELSEWHERE.
DEVELOPING LOW PRESSURE OFF THE WEST COAST AND HIGH PRESSURE OVER
NEW MEXICO WILL OPEN THE DOOR FOR MONSOON MOISTURE TO RETURN FOR THE
MIDDLE OF THE WEEK. DURING THIS TIME IT APPEARS THE BEST CHANCES FOR
THUNDERSTORMS WILL BE FROM LAS VEGAS SOUTH AND EAST.
&&
.UPDATE...SATELLITE AND RADAR LOOPS SHOWED ISOLATED SHOWERS POPPING
THIS MORNING OVER NORTHWEST ARIZONA EASTERN PORTIONS OF CLARK
COUNTY. A LOOK BACK AT THE IR SATELLITE LOOP REVEALS THAT THIS
MOISTURE WAS TRANSPORTED UP FROM SOUTH CENTRAL ARIZONA IN A
SOUTHEAST FLOW THAT DEVELOPED IN THE 850-700 LAYER. THIS IS
INDICATED IN MOST MODELS EVEN THOUGH THE FLOW THE H5 AND ABOVE FLOW
IS STILL DRY SOUTHWEST. RADAR CROSS SECTIONS SHOW INDIVIDUAL CELLS
EXTEND FROM 10-25 KFT MSL AND NO LIGHTNING HAS BEEN DETECTED YET.
LOCAL HIGH RES MODELS AND THE HRRR ALL INDICATE CONVECTION
CONTINUING ACROSS MOHAVE COUNTY AND NORTHEAST CLARK COUNTY THROUGH
THE AFTERNOON. A BRIEF THUNDERSTORM CANNOT BE COMPLETELY RULED OUT
OVER EASTERN PARTS OF THE LAS VEGAS VALLEY OR THE NEARBY MOUNTAINS.
THE FORECAST WAS UPDATED TO REFLECT THESE TRENDS.
&&
.AVIATION...FOR MCCARRAN...A FEW SHOWERS OR THUNDERSTORMS WILL BE
POSSIBLE IN THE PEACH SPRINGS CORRIDOR AND OVER EASTERN CLARK COUNTY
TODAY DUE TO MOISTURE THAT WAS PULLED UP FROM SOUTH CENTRAL ARIZONA
OVERNIGHT. WINDS WILL FAVOR AN EAST TO SOUTHEAST DIRECTION DURING
THE AFTERNOON AND SOUTHWEST OVERNIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...FEW-SCT CLOUDS AOA 12K FEET WITH ISOLATED SHOWERS OR
THUNDERSTORMS ARE EXPECTED OVER NORTHWEST ARIZONA AND SOUTHEAST
NEVADA TODAY. SMOKE FROM THE 1 WILLOW FIRE NEAR KEED IS EXPECTED TO
DRIFT NORTH AND MAY IMPACT SITES ALONG THE COLORADO RIVER VALLEY AND
ACROSS NORTHWEST ARIZONA. OTHERWISE QUIET CONDITIONS ARE EXPECTED
WITH SOUTHERLY WINDS INCREASING TO 10-20 KTS DURING THE AFTERNOON
HOURS.
&&
.PREV DISCUSSION...
208 AM PDT SUN AUG 9 2015
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.
CONDITIONS REMAIN QUIET THIS MORNING. THE MAIN ITEM OF CONCERN IS
THE 1 WILLOW FIRE BETWEEN MOHAVE VALLEY AND TOPOCK AND THE SMOKE
ASSOCIATED WITH IT. A TRAINED SPOTTER REPORTED VISIBILITY DOWN TO 3/4
MILE NEAR GRAND CANYON WEST (SOME 90 MILES AWAY FROM THE FIRE) LAST
EVENING AND HAVE KEPT SMOKE IN THE FORECAST FOR TODAY. BASED ON
RADAR DATA SMOKE ACTIVITY HAS BEEN SOMEWHAT TEMPERED OVERNIGHT AND
THUS HAVE REDUCED THE AREAL EXTENT OF SMOKE AFTER 12Z. ONCE THE SUN
COMES UP WE`LL HAVE TO RE-EVALUATE BASED ON SATELLITE IMAGERY AND
MAKE FURTHER ADJUSTMENTS. SMOKE IS EXPECTED TO CONTINUE TO DRIFT
NORTH-NORTHEAST DURING THE MORNING...BUT 700MB FLOW DOES BACK
SLIGHTLY BY THE AFTERNOON AND COULD DIRECT SMOKE UP THE COLORADO
RIVER VALLEY...OR EVEN TOWARD LAS VEGAS (IF THE FIRE REMAINS ACTIVE
ENOUGH TO PRODUCE A PLUME).
OUTSIDE OF THE SMOKE...MAINLY QUIET CONDITIONS ARE EXPECTED TODAY
AND MONDAY AS DRY SOUTHWEST FLOW REMAINS IN PLACE ACROSS THE REGION.
THIS WILL HELP KEEP THE BRUNT OF THE MONSOON MOISTURE EAST OF THE
FORECAST AREA. LIKE YESTERDAY...THE BOUNDARY BETWEEN DRY AND MOIST
WILL BE SOMEWHERE IN THE VICINITY OF THE EASTERN MOHAVE COUNTY LINE
BOTH TODAY AND MONDAY. THIS MEANS THAT A STRAY SHOWER IS
POSSIBLE...BUT THE CHANCES ARE LARGELY BELOW 10 PERCENT. A WEAK WAVE
MOVING THROUGH THE FLOW WILL ACT TO HELP ENHANCE SOUTHERLY BREEZES
THIS AFTERNOON...AND THESE BREEZES WILL CONTINUE THROUGH MONDAY.
FOR TUESDAY...I`VE CARRIED ON THE SLIGHT CHANCE OF PRECIPITATION
OVER MOHAVE AND FAR EASTERN LINCOLN COUNTIES. THE GOING FORECAST
APPEARS TO BE LEANED HEAVILY TOWARD THE GFS...AND WITH IT`S RECENT
TRACK RECORD I WAS RELUCTANT TO CHANGE IT TOO MUCH. HOWEVER IT`S
WORTH NOTING THAT MODEL AGREEMENT IS POOR ON THE PLACEMENT OF
MOISTURE AND INSTABILITY THERE...WITH THE ECMWF KEEPING THINGS DRY
AND STABLE UNTIL WEDNESDAY.
.LONG TERM...WEDNESDAY THROUGH SATURDAY.
NOT MUCH CHANGE FROM PREVIOUS THINKING. CWA STILL REMAINS CAUGHT
BETWEEN DRY SOUTHWEST FLOW FARTHER TO THE NORTHWEST /ASSOCIATED WITH
A PACIFIC TROUGH/ AND MOIST SOUTH TO SOUTHEAST FLOW TO THE EAST
/ASSOCIATED WITH A BIG RIDGE TO THE EAST/. THE MODELS DIFFER A BIT
IN THEIR HANDLING OF THE LARGE SCALE FEATURES...WITH THE ECMWF
HAVING TRENDED TOWARD A STRONGER RIDGE DRIFTING FARTHER WEST /NEARLY
OVERHEAD BY SATURDAY/ AND THE GFS LOOKING NEARLY IDENTICAL TO ITS
PREVIOUS RUNS. MADE VERY LITTLE CHANGE TO THE FORECAST...WHICH
DEPICTS THUNDERSTORM CHANCES ROUGHLY FROM LAS VEGAS EASTWARD ON
WEDNESDAY AND THURSDAY...FOLLOWED BY A SLIGHT DRYING TREND FRIDAY
AND SATURDAY. TEMPERATURES ARE A MINOR CONCERN. THE ECMWF...SINCE IT
SHOWS THE RIDGE RETROGRADING TOWARD OUR AREA...RAMPS HIGH TEMPS UP
TO NEAR EXCESSIVE HEAT WARNING CRITERIA BY SATURDAY. SINCE THIS IS
THE FIRST RUN OF THE ECMWF TO SHOW THIS TREND...AND THE GFS DOES NOT
SUPPORT IT...CONSIDER IT TO BE A LOW PROBABILITY SOLUTION AT THIS
TIME...AND FORECAST REMAINS ABOUT FIVE DEGREES BELOW THE ECE MOS
GUIDANCE. BUT IT IS SOMETHING TO KEEP IN THE BACK OF THE MIND.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...ADAIR
SHORT TERM...WOLCOTT
LONG TERM.............MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1040 AM EDT SUN AUG 9 2015
.SYNOPSIS...
ANOTHER NICE DAY IS EXPECTED ACROSS THE NORTH COUNTRY
WITH MAINLY DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. AN ISOLATED
SHOWER OR SPRINKLE IS POSSIBLE ACROSS NORTHEAST VERMONT THIS
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE FORECASTED FOR MONDAY...BEFORE SHOWERS ARRIVE ON
MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1040 AM EDT SUNDAY...JUST A FEW MINOR UPDATES NEEDED TO
THIS MORNING`S FORECAST AT THIS TIME, MAINLY TO ADJUST FOR CURRENT
TEMP AND SKY COVER TRENDS. TEMPS RUNNING A DEGREE OR TWO WARMER
THAN PREVIOUS FORECAST SO HAVE BUMPED UP SLIGHTLY THERE. OF
GREATER INTEREST IS AN AREA OF FOG AND LOW CLOUDS OVER THE UPPER
ST. LAWRENCE AND MONTREAL WHICH IS TRYING TO SAG SOUTHWARD ACROSS
THE BORDER INTO NORTHERN NEW YORK. ITS HAVING A TOUGH TIME THOUGH
WITH THE STRONG SUBSIDENCE OVER THE BTV CWA AND EXPECT AS MIXING
GETS GOING HERE IN A COUPLE OF HOURS THIS AREA WILL DISSIPATE.
WE`LL BE LEFT WITH SOME FAIR WEATHER CUMULUS BECOMING SCT-BKN
THROUGH THE AFTERNOON AND DISSIPATING TOWARDS SUNSET. REST OF
FORECAST UNCHANGED.
PREVIOUS DISCUSSION...FORECAST FOCUS TODAY WILL BE CHANCE FOR AN
ISOLATED SHOWER ACROSS THE NORTHEAST KINGDOM OF VT. CRNT WATER
VAPOR SHOWS MID/UPPER LVL TROF CONTS...WITH WEAK S/W ENERGY DIVING
SOUTH FROM EASTERN CANADA. ALSO...WATER VAPOR SHOWS VERY DRY AIR
AHEAD OF THIS SYSTEM...SO ANY PRECIP CHCS TODAY WILL BE VERY
ISOLATED AND CONFINED TO THE NORTHEAST KINGDOM OR MTNS OF NORTHERN
VT. BTV 4KM IS MOST AGGRESSIVE WITH SHOWING QPF AND ASSOCIATED
COMPOSITE REFLECTIVITY RETURNS ACROSS MOST OF THE HIGHER TRRN OF
VT THIS AFTN...BUT GIVEN PROGGED SOUNDING MOISTURE
PROFILES...THINKING THIS IS OVERDONE. WL USE A BLEND OF NAM/GFS
AND HRRR TO MENTION SCHC WITH A SMALL AREA OF CHC POPS ACROSS
ESSEX COUNTY VT. REST OF CWA WILL REMAIN DRY. TEMPS WILL BE
SEVERAL DEGREES WARMER THAN YESTERDAY WITH HIGHS GENERALLY IN THE
70S TO NEAR 80F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 345 AM EDT SUNDAY...OUR NICE PERIOD OF DRY
WEATHER WILL BE COMING TO AN END BY TUESDAY...AS MID/UPPER LVL TROF
AND ASSOCIATED SFC LOW PRES IMPACT THE NE CONUS. FOR MONDAY...BEST
850 TO 500MB MOISTURE IS WEST OF OUR CWA THRU 00Z..ALONG WITH
FORCING ASSOCIATED WITH INITIAL 5H VORT. WILL CONT TO MENTION CHC
POPS TWD 00Z TUESDAY ACROSS THE SLV AND WESTERN DACKS. PROGGED 85H
TEMPS WARM BTWN 12-14C BY 18Z MONDAY...SUPPORTING M/U 70S MTN TOWNS
TO L/M 80S WARMER VALLEYS.
OVERALL...NAM/GFS AND ECMWF HAVE COME INTO PRETTY GOOD AGREEMENT
WITH HANDLING THE DEEPENING OF MID/UPPER LVL TROF ACROSS THE GREAT
LAKES AND SFC LOW PRES TRACKING FROM THE OHIO VALLEY MONDAY NIGHT
INTO THE SLV BY TUES. IN ADDITION...MODELS HAVE TRENDED SEVERAL
HOURS SLOWER WITH THE PRECIP ARRIVE ON MONDAY NIGHT INTO TUESDAY
ACROSS OUR CWA...WITH HEAVIEST QPF AXIS OF UP TO 1.0 OF RAIN
EXPECTED OVER NORTHERN NY BY TUES AFTN. LOW LEVEL FORCING/ ADVECTION
OF MOISTURE IS IMPRESSIVE ASSOCIATED WITH NOSE OF 85H JET OF 45 TO
50 KNOTS IMPACTING OUR CWA BY 12Z TUESDAY. GFS/NAM SHOW A STRONG
BAND OF 850 TO 700MB FGEN FORCING...ALONG WITH GOOD LVLL MOISTURE
CONVERGENCE LIFTING FROM SW TO NE ACRS OUR CWA BTWN 09Z AND 18Z
TUESDAY.
HAVE NOTED SOME HIGHER RESOLUTION MODELS SHOWING IMPACTS OF
SE TO SOUTHWEST WINDS ON THE ASSOCIATED QPF FIELDS WITH SOME
SHADOWING OVER THE CPV AND PARTS OF THE NEK. GIVEN THE MOISTURE FEED
WITH PWS AROUND 1.50" AND GOOD UPPER LEVEL DYNAMICS WITH APPROACHING
TROF AND HEIGHT FALLS...A WIDESPREAD RAINFALL IS VERY LIKELY LATE
MONDAY NIGHT INTO TUESDAY. WILL CONT THE TREND AND MENTION CAT POPS
ACRS OUR CWA...BUT TRRN WILL INFLUENCE QPF FIELDS....WITH HIGHEST
VALUES OF UP TO 1.0 OCCURRING ACRS THE NORTHERN NY/HIGH PEAKS
REGION...GIVEN THE LLVL JET ORIENTATION. MEANWHILE...VALUES ACROSS
VT WILL RANGE FROM 0.25 TO 0.75" WITH HIGHEST AMOUNTS ON SE UPSLOPE
AREAS OF THE GREEN MTNS.
SOUNDINGS SHOW RIDGETOP WINDS BTWN 45 AND 50 KNOTS ON TUESDAY
MORNING...BUT INVERSION LEVEL IS AROUND 2000 FT....SUPPORTING
MIXED LAYER WINDS TO THE SURFACE UP TO 35 MPH OR SO ALONG THE
WESTERN SLOPES AND HIGHER TRRN. TEMPS TUES WILL BE TRICKY WITH
1000 TO 500MB THICKNESS RIDGE OVERHEAD...BUT LOTS OF CLOUDS AND
PRECIP AROUND. THINKING A FEW BREAKS WILL DEVELOP IN MID LVL DRY
SLOT OVER THE SLV/WESTERN DACKS AND THIS AREA WILL REACH
80F...WHILE MOST OF THE OTHER SITES STAY IN THE M/U 60S MTNS TO
L/M 70S CPV/SOUTHERN VT.
A RUMBLE OF THUNDER ASSOCIATED WITH THE DYNAMICS CANNOT BE RULED
OUT ON TUESDAY MORNING...WITH ANOTHER CHC OF A RUMBLE ON TUES AFTN
IN THE WARM SECTOR OVER SLV. ALSO...NOTED WEAK ELEVATED
INSTABILITY LAYER WITH ML CAPE VALUES AROUND 400 J/KG ON MONDAY
NIGHT/TUESDAY MORNING...ASSOCIATED WITH NOSE OF 85H JET AND STRONG
LLVL WAA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 354 AM EDT SUNDAY...RATHER ACTIVE WEATHER WITH CHANCE OF
SHOWERS FOR MUCH OF THE PERIOD AS UPPER LEVEL TROUGH REMAINS OVER
THE EAST.
WEAK SURFACE BOUNDARY WILL MOVE SLOWLY EAST OF THE AREA TUESDAY
NIGHT...WITH HIGHEST PRECIPITABLE WATER VALUES SHIFTING TO THE EAST
AS WELL. UPPER LEVEL LOW LAGS BEHIND HOWEVER...SO WHILE HIGHEST
CHANCE OF SHOWERS WILL BE DURING THE EVENING...THERE WILL BE A
CONTINUED CHANCE FOR A FEW SHOWERS DURING THE OVERNIGHT AS WELL.
WITH UPPER LEVEL LOW AND ASSOCIATED COLD POOL ALOFT STILL OVER THE
REGION ON WEDNESDAY...WE CAN EXPECT MORE CLOUDS AND A CONTINUED
CHANCE OF SHOWERS. WEST TO NORTHWEST UPSLOPE FLOW WILL HELP PROVIDE
SOURCE OF LIFT FOR BETTER COVERAGE OVER THE HIGHER TERRAIN. LIMITED
INSTABILITY...BUT AN ISOLATED THUNDERSTORM ALSO POSSIBLE.
UPPER TROUGH SLOW TO DEPART THURSDAY...SO STILL CHANCE OF A FEW
SHOWERS. DRIER CONDITIONS LATER THURSDAY INTO FRIDAY MORNING WITH
SHORTWAVE RIDGING ALOFT AT 500MB. FROM FRIDAY ONWARD YET ANOTHER
UPPER LEVEL TROUGH WILL APPROACH FROM THE NORTHERN GREAT LAKES
REGION AND RE-ESTABLISH THE EASTERN US TROUGH AND A CHANCE FOR MORE
SHOWERS AND A FEW WIDELY SCATTERED STORMS.
AS FOR TEMPS...MAX TEMPS WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
WITH HIGHS MAINLY IN THE 70S...PERHAPS AROUND 80 IN SPOTS FRIDAY AND
SATURDAY. MINS WILL BE IN THE 50S TO AROUND 60...GENERALLY WITHIN
A FEW DEGREES OF NORMAL FOR MID AUGUST.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR EARLY TODAY AT MPV/SLK AND AGAIN LATE
TONIGHT AT MPV/SLK/MSS. FOG/BR LIFTS BY AROUND 13Z TODAY WITH
CLEAR SKIES THIS MORNING GIVING WAY TO SCT-BKN DECK OF CUMULUS IN
THE AFTERNOON...WITH ALL SITES VFR. WINDS BECOME GENERALLY
NORTHERLY FROM 4-8 KNOTS TODAY...BUT WITH LIGHT FLOW...THEY WILL
BE LOCALLY VARIABLE. WINDS LIGHT/CALM TONIGHT...EXCEPT SE 8-10 KTS
AT RUT WITH DRAINAGE WIND.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MONDAY THROUGH 00Z TUESDAY...VFR.
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY ONWARD...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS. SHOWERS DIMINISHING THURSDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...LAHIFF/TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
740 AM EDT SUN AUG 9 2015
.SYNOPSIS...
ANOTHER NICE DAY IS EXPECTED ACROSS THE NORTH COUNTRY
WITH MAINLY DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. AN ISOLATED
SHOWER OR SPRINKLE IS POSSIBLE ACROSS NORTHEAST VERMONT THIS
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE FORECASTED FOR MONDAY...BEFORE SHOWERS ARRIVE ON
MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 711 AM EDT SUNDAY...VERY MINOR CHANGES TO CRNT FCST THAT
INCLUDED ADJUSTING FOR LATEST SATL TRENDS AND PLACE THE LATEST OBS
INTO THE GRIDS. DEEPER MOISTURE ASSOCIATED WITH 5H VORT CONTS TO
MOVE ACROSS CENTRAL/EASTERN VT THIS MORNING....WITH WATER VAPOR
SHOWING LARGE SCALE AREA OF SUBSIDENCE DEVELOPING OVER NORTHERN
NY. THIS WILL RESULT IN MOSTLY SUNNY SKIES TODAY AND LIMIT OVERALL
COVERAGE OF ANY POTENTIAL SHOWERS. HIGHS WILL WARM INTO THE 70S TO
NEAR 80 MOST LOCATIONS WITH LIGHT NORTH WINDS.
FORECAST FOCUS TODAY WILL BE CHANCE FOR AN ISOLATED SHOWER ACROSS
THE NORTHEAST KINGDOM OF VT. CRNT WATER VAPOR SHOWS MID/UPPER LVL
TROF CONTS...WITH WEAK S/W ENERGY DIVING SOUTH FROM EASTERN
CANADA. ALSO...WATER VAPOR SHOWS VERY DRY AIR AHEAD OF THIS
SYSTEM...SO ANY PRECIP CHCS TODAY WILL BE VERY ISOLATED AND
CONFINED TO THE NORTHEAST KINGDOM OR MTNS OF NORTHERN VT. BTV 4KM
IS MOST AGGRESSIVE WITH SHOWING QPF AND ASSOCIATED COMPOSITE
REFLECTIVITY RETURNS ACROSS MOST OF THE HIGHER TRRN OF VT THIS
AFTN...BUT GIVEN PROGGED SOUNDING MOISTURE PROFILES...THINKING
THIS IS OVERDONE. WL USE A BLEND OF NAM/GFS AND HRRR TO MENTION
SCHC WITH A SMALL AREA OF CHC POPS ACROSS ESSEX COUNTY VT. REST OF
CWA WILL REMAIN DRY. TEMPS WILL BE SEVERAL DEGREES WARMER THAN
YESTERDAY WITH HIGHS GENERALLY IN THE 70S TO NEAR 80F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 345 AM EDT SUNDAY...OUR NICE PERIOD OF DRY
WEATHER WILL BE COMING TO AN END BY TUESDAY...AS MID/UPPER LVL TROF
AND ASSOCIATED SFC LOW PRES IMPACT THE NE CONUS. FOR MONDAY...BEST
850 TO 500MB MOISTURE IS WEST OF OUR CWA THRU 00Z..ALONG WITH
FORCING ASSOCIATED WITH INITIAL 5H VORT. WILL CONT TO MENTION CHC
POPS TWD 00Z TUESDAY ACROSS THE SLV AND WESTERN DACKS. PROGGED 85H
TEMPS WARM BTWN 12-14C BY 18Z MONDAY...SUPPORTING M/U 70S MTN TOWNS
TO L/M 80S WARMER VALLEYS.
OVERALL...NAM/GFS AND ECMWF HAVE COME INTO PRETTY GOOD AGREEMENT
WITH HANDLING THE DEEPENING OF MID/UPPER LVL TROF ACROSS THE GREAT
LAKES AND SFC LOW PRES TRACKING FROM THE OHIO VALLEY MONDAY NIGHT
INTO THE SLV BY TUES. IN ADDITION...MODELS HAVE TRENDED SEVERAL
HOURS SLOWER WITH THE PRECIP ARRIVE ON MONDAY NIGHT INTO TUESDAY
ACROSS OUR CWA...WITH HEAVIEST QPF AXIS OF UP TO 1.0 OF RAIN
EXPECTED OVER NORTHERN NY BY TUES AFTN. LOW LEVEL FORCING/ ADVECTION
OF MOISTURE IS IMPRESSIVE ASSOCIATED WITH NOSE OF 85H JET OF 45 TO
50 KNOTS IMPACTING OUR CWA BY 12Z TUESDAY. GFS/NAM SHOW A STRONG
BAND OF 850 TO 700MB FGEN FORCING...ALONG WITH GOOD LVLL MOISTURE
CONVERGENCE LIFTING FROM SW TO NE ACRS OUR CWA BTWN 09Z AND 18Z
TUESDAY.
HAVE NOTED SOME HIGHER RESOLUTION MODELS SHOWING IMPACTS OF
SE TO SOUTHWEST WINDS ON THE ASSOCIATED QPF FIELDS WITH SOME
SHADOWING OVER THE CPV AND PARTS OF THE NEK. GIVEN THE MOISTURE FEED
WITH PWS AROUND 1.50" AND GOOD UPPER LEVEL DYNAMICS WITH APPROACHING
TROF AND HEIGHT FALLS...A WIDESPREAD RAINFALL IS VERY LIKELY LATE
MONDAY NIGHT INTO TUESDAY. WILL CONT THE TREND AND MENTION CAT POPS
ACRS OUR CWA...BUT TRRN WILL INFLUENCE QPF FIELDS....WITH HIGHEST
VALUES OF UP TO 1.0 OCCURRING ACRS THE NORTHERN NY/HIGH PEAKS
REGION...GIVEN THE LLVL JET ORIENTATION. MEANWHILE...VALUES ACROSS
VT WILL RANGE FROM 0.25 TO 0.75" WITH HIGHEST AMOUNTS ON SE UPSLOPE
AREAS OF THE GREEN MTNS.
SOUNDINGS SHOW RIDGETOP WINDS BTWN 45 AND 50 KNOTS ON TUESDAY
MORNING...BUT INVERSION LEVEL IS AROUND 2000 FT....SUPPORTING
MIXED LAYER WINDS TO THE SURFACE UP TO 35 MPH OR SO ALONG THE
WESTERN SLOPES AND HIGHER TRRN. TEMPS TUES WILL BE TRICKY WITH
1000 TO 500MB THICKNESS RIDGE OVERHEAD...BUT LOTS OF CLOUDS AND
PRECIP AROUND. THINKING A FEW BREAKS WILL DEVELOP IN MID LVL DRY
SLOT OVER THE SLV/WESTERN DACKS AND THIS AREA WILL REACH
80F...WHILE MOST OF THE OTHER SITES STAY IN THE M/U 60S MTNS TO
L/M 70S CPV/SOUTHERN VT.
A RUMBLE OF THUNDER ASSOCIATED WITH THE DYNAMICS CANNOT BE RULED
OUT ON TUESDAY MORNING...WITH ANOTHER CHC OF A RUMBLE ON TUES AFTN
IN THE WARM SECTOR OVER SLV. ALSO...NOTED WEAK ELEVATED
INSTABILITY LAYER WITH ML CAPE VALUES AROUND 400 J/KG ON MONDAY
NIGHT/TUESDAY MORNING...ASSOCIATED WITH NOSE OF 85H JET AND STRONG
LLVL WAA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 354 AM EDT SUNDAY...RATHER ACTIVE WEATHER WITH CHANCE OF
SHOWERS FOR MUCH OF THE PERIOD AS UPPER LEVEL TROUGH REMAINS OVER
THE EAST.
WEAK SURFACE BOUNDARY WILL MOVE SLOWLY EAST OF THE AREA TUESDAY
NIGHT...WITH HIGHEST PRECIPITABLE WATER VALUES SHIFTING TO THE EAST
AS WELL. UPPER LEVEL LOW LAGS BEHIND HOWEVER...SO WHILE HIGHEST
CHANCE OF SHOWERS WILL BE DURING THE EVENING...THERE WILL BE A
CONTINUED CHANCE FOR A FEW SHOWERS DURING THE OVERNIGHT AS WELL.
WITH UPPER LEVEL LOW AND ASSOCIATED COLD POOL ALOFT STILL OVER THE
REGION ON WEDNESDAY...WE CAN EXPECT MORE CLOUDS AND A CONTINUED
CHANCE OF SHOWERS. WEST TO NORTHWEST UPSLOPE FLOW WILL HELP PROVIDE
SOURCE OF LIFT FOR BETTER COVERAGE OVER THE HIGHER TERRAIN. LIMITED
INSTABILITY...BUT AN ISOLATED THUNDERSTORM ALSO POSSIBLE.
UPPER TROUGH SLOW TO DEPART THURSDAY...SO STILL CHANCE OF A FEW
SHOWERS. DRIER CONDITIONS LATER THURSDAY INTO FRIDAY MORNING WITH
SHORTWAVE RIDGING ALOFT AT 500MB. FROM FRIDAY ONWARD YET ANOTHER
UPPER LEVEL TROUGH WILL APPROACH FROM THE NORTHERN GREAT LAKES
REGION AND RE-ESTABLISH THE EASTERN US TROUGH AND A CHANCE FOR MORE
SHOWERS AND A FEW WIDELY SCATTERED STORMS.
AS FOR TEMPS...MAX TEMPS WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
WITH HIGHS MAINLY IN THE 70S...PERHAPS AROUND 80 IN SPOTS FRIDAY AND
SATURDAY. MINS WILL BE IN THE 50S TO AROUND 60...GENERALLY WITHIN
A FEW DEGREES OF NORMAL FOR MID AUGUST.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR EARLY TODAY AT MPV/SLK AND AGAIN LATE
TONIGHT AT MPV/SLK/MSS. FOG/BR LIFTS BY AROUND 13Z TODAY WITH
CLEAR SKIES THIS MORNING GIVING WAY TO SCT-BKN DECK OF CUMULUS IN
THE AFTERNOON...WITH ALL SITES VFR. WINDS BECOME GENERALLY
NORTHERLY FROM 4-8 KNOTS TODAY...BUT WITH LIGHT FLOW...THEY WILL
BE LOCALLY VARIABLE. WINDS LIGHT/CALM TONIGHT...EXCEPT SE 8-10 KTS
AT RUT WITH DRAINAGE WIND.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MONDAY THROUGH 00Z TUESDAY...VFR.
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY ONWARD...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS. SHOWERS DIMINISHING THURSDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
713 AM EDT SUN AUG 9 2015
.SYNOPSIS...
ANOTHER NICE DAY IS EXPECTED ACROSS THE NORTH COUNTRY
WITH MAINLY DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. AN ISOLATED
SHOWER OR SPRINKLE IS POSSIBLE ACROSS NORTHEAST VERMONT THIS
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE FORECASTED FOR MONDAY...BEFORE SHOWERS ARRIVE ON
MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 711 AM EDT SUNDAY...VERY MINOR CHANGES TO CRNT FCST THAT
INCLUDED ADJUSTING FOR LATEST SATL TRENDS AND PLACE THE LATEST OBS
INTO THE GRIDS. DEEPER MOISTURE ASSOCIATED WITH 5H VORT CONTS TO
MOVE ACROSS CENTRAL/EASTERN VT THIS MORNING....WITH WATER VAPOR
SHOWING LARGE SCALE AREA OF SUBSIDENCE DEVELOPING OVER NORTHERN
NY. THIS WILL RESULT IN MOSTLY SUNNY SKIES TODAY AND LIMIT OVERALL
COVERAGE OF ANY POTENTIAL SHOWERS. HIGHS WILL WARM INTO THE 70S TO
NEAR 80 MOST LOCATIONS WITH LIGHT NORTH WINDS.
FORECAST FOCUS TODAY WILL BE CHANCE FOR AN ISOLATED SHOWER ACROSS
THE NORTHEAST KINGDOM OF VT. CRNT WATER VAPOR SHOWS MID/UPPER LVL
TROF CONTS...WITH WEAK S/W ENERGY DIVING SOUTH FROM EASTERN
CANADA. ALSO...WATER VAPOR SHOWS VERY DRY AIR AHEAD OF THIS
SYSTEM...SO ANY PRECIP CHCS TODAY WILL BE VERY ISOLATED AND
CONFINED TO THE NORTHEAST KINGDOM OR MTNS OF NORTHERN VT. BTV 4KM
IS MOST AGGRESSIVE WITH SHOWING QPF AND ASSOCIATED COMPOSITE
REFLECTIVITY RETURNS ACROSS MOST OF THE HIGHER TRRN OF VT THIS
AFTN...BUT GIVEN PROGGED SOUNDING MOISTURE PROFILES...THINKING
THIS IS OVERDONE. WL USE A BLEND OF NAM/GFS AND HRRR TO MENTION
SCHC WITH A SMALL AREA OF CHC POPS ACROSS ESSEX COUNTY VT. REST OF
CWA WILL REMAIN DRY. TEMPS WILL BE SEVERAL DEGREES WARMER THAN
YESTERDAY WITH HIGHS GENERALLY IN THE 70S TO NEAR 80F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 345 AM EDT SUNDAY...OUR NICE PERIOD OF DRY
WEATHER WILL BE COMING TO AN END BY TUESDAY...AS MID/UPPER LVL TROF
AND ASSOCIATED SFC LOW PRES IMPACT THE NE CONUS. FOR MONDAY...BEST
850 TO 500MB MOISTURE IS WEST OF OUR CWA THRU 00Z..ALONG WITH
FORCING ASSOCIATED WITH INITIAL 5H VORT. WILL CONT TO MENTION CHC
POPS TWD 00Z TUESDAY ACROSS THE SLV AND WESTERN DACKS. PROGGED 85H
TEMPS WARM BTWN 12-14C BY 18Z MONDAY...SUPPORTING M/U 70S MTN TOWNS
TO L/M 80S WARMER VALLEYS.
OVERALL...NAM/GFS AND ECMWF HAVE COME INTO PRETTY GOOD AGREEMENT
WITH HANDLING THE DEEPENING OF MID/UPPER LVL TROF ACROSS THE GREAT
LAKES AND SFC LOW PRES TRACKING FROM THE OHIO VALLEY MONDAY NIGHT
INTO THE SLV BY TUES. IN ADDITION...MODELS HAVE TRENDED SEVERAL
HOURS SLOWER WITH THE PRECIP ARRIVE ON MONDAY NIGHT INTO TUESDAY
ACROSS OUR CWA...WITH HEAVIEST QPF AXIS OF UP TO 1.0 OF RAIN
EXPECTED OVER NORTHERN NY BY TUES AFTN. LOW LEVEL FORCING/ ADVECTION
OF MOISTURE IS IMPRESSIVE ASSOCIATED WITH NOSE OF 85H JET OF 45 TO
50 KNOTS IMPACTING OUR CWA BY 12Z TUESDAY. GFS/NAM SHOW A STRONG
BAND OF 850 TO 700MB FGEN FORCING...ALONG WITH GOOD LVLL MOISTURE
CONVERGENCE LIFTING FROM SW TO NE ACRS OUR CWA BTWN 09Z AND 18Z
TUESDAY.
HAVE NOTED SOME HIGHER RESOLUTION MODELS SHOWING IMPACTS OF
SE TO SOUTHWEST WINDS ON THE ASSOCIATED QPF FIELDS WITH SOME
SHADOWING OVER THE CPV AND PARTS OF THE NEK. GIVEN THE MOISTURE FEED
WITH PWS AROUND 1.50" AND GOOD UPPER LEVEL DYNAMICS WITH APPROACHING
TROF AND HEIGHT FALLS...A WIDESPREAD RAINFALL IS VERY LIKELY LATE
MONDAY NIGHT INTO TUESDAY. WILL CONT THE TREND AND MENTION CAT POPS
ACRS OUR CWA...BUT TRRN WILL INFLUENCE QPF FIELDS....WITH HIGHEST
VALUES OF UP TO 1.0 OCCURRING ACRS THE NORTHERN NY/HIGH PEAKS
REGION...GIVEN THE LLVL JET ORIENTATION. MEANWHILE...VALUES ACROSS
VT WILL RANGE FROM 0.25 TO 0.75" WITH HIGHEST AMOUNTS ON SE UPSLOPE
AREAS OF THE GREEN MTNS.
SOUNDINGS SHOW RIDGETOP WINDS BTWN 45 AND 50 KNOTS ON TUESDAY
MORNING...BUT INVERSION LEVEL IS AROUND 2000 FT....SUPPORTING
MIXED LAYER WINDS TO THE SURFACE UP TO 35 MPH OR SO ALONG THE
WESTERN SLOPES AND HIGHER TRRN. TEMPS TUES WILL BE TRICKY WITH
1000 TO 500MB THICKNESS RIDGE OVERHEAD...BUT LOTS OF CLOUDS AND
PRECIP AROUND. THINKING A FEW BREAKS WILL DEVELOP IN MID LVL DRY
SLOT OVER THE SLV/WESTERN DACKS AND THIS AREA WILL REACH
80F...WHILE MOST OF THE OTHER SITES STAY IN THE M/U 60S MTNS TO
L/M 70S CPV/SOUTHERN VT.
A RUMBLE OF THUNDER ASSOCIATED WITH THE DYNAMICS CANNOT BE RULED
OUT ON TUESDAY MORNING...WITH ANOTHER CHC OF A RUMBLE ON TUES AFTN
IN THE WARM SECTOR OVER SLV. ALSO...NOTED WEAK ELEVATED
INSTABILITY LAYER WITH ML CAPE VALUES AROUND 400 J/KG ON MONDAY
NIGHT/TUESDAY MORNING...ASSOCIATED WITH NOSE OF 85H JET AND STRONG
LLVL WAA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 354 AM EDT SUNDAY...RATHER ACTIVE WEATHER WITH CHANCE OF
SHOWERS FOR MUCH OF THE PERIOD AS UPPER LEVEL TROUGH REMAINS OVER
THE EAST.
WEAK SURFACE BOUNDARY WILL MOVE SLOWLY EAST OF THE AREA TUESDAY
NIGHT...WITH HIGHEST PRECIPITABLE WATER VALUES SHIFTING TO THE EAST
AS WELL. UPPER LEVEL LOW LAGS BEHIND HOWEVER...SO WHILE HIGHEST
CHANCE OF SHOWERS WILL BE DURING THE EVENING...THERE WILL BE A
CONTINUED CHANCE FOR A FEW SHOWERS DURING THE OVERNIGHT AS WELL.
WITH UPPER LEVEL LOW AND ASSOCIATED COLD POOL ALOFT STILL OVER THE
REGION ON WEDNESDAY...WE CAN EXPECT MORE CLOUDS AND A CONTINUED
CHANCE OF SHOWERS. WEST TO NORTHWEST UPSLOPE FLOW WILL HELP PROVIDE
SOURCE OF LIFT FOR BETTER COVERAGE OVER THE HIGHER TERRAIN. LIMITED
INSTABILITY...BUT AN ISOLATED THUNDERSTORM ALSO POSSIBLE.
UPPER TROUGH SLOW TO DEPART THURSDAY...SO STILL CHANCE OF A FEW
SHOWERS. DRIER CONDITIONS LATER THURSDAY INTO FRIDAY MORNING WITH
SHORTWAVE RIDGING ALOFT AT 500MB. FROM FRIDAY ONWARD YET ANOTHER
UPPER LEVEL TROUGH WILL APPROACH FROM THE NORTHERN GREAT LAKES
REGION AND RE-ESTABLISH THE EASTERN US TROUGH AND A CHANCE FOR MORE
SHOWERS AND A FEW WIDELY SCATTERED STORMS.
AS FOR TEMPS...MAX TEMPS WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
WITH HIGHS MAINLY IN THE 70S...PERHAPS AROUND 80 IN SPOTS FRIDAY AND
SATURDAY. MINS WILL BE IN THE 50S TO AROUND 60...GENERALLY WITHIN
A FEW DEGREES OF NORMAL FOR MID AUGUST.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR LATE TONIGHT AND EARLY SUNDAY MORNING AT
SLK/MSS/MPV. BKN HIGH CIRRUS DECK WILL PROGRESS EASTWARD
OVERNIGHT...SLOWLY CLEARING THE REGION BETWEEN THROUGH 11Z. WITH
THE CLEARING WILL COME THE POTENTIAL FOR FOG/BR DEVELOPMENT.
GREATEST LIKELIHOOD TO SEE LIFR FOG WILL BE AT SLK & MPV...WITH
THE POSSIBILITY AT MSS AS WELL. FOG/BR LIFTS BY AROUND 12Z WITH
CLEAR SKIES GIVING WAY TO A DEVELOPING CU FIELD IN THE
AFTERNOON...WITH ALL SITES VFR. WINDS LIGHT AND LOCALLY VARIABLE
OVERNIGHT (EXCEPT SE AT RUT WITH DRAINAGE WIND) BECOME GENERALLY
NORTHERLY FROM 4-7 KNOTS ON SUNDAY...BUT WITH LIGHT FLOW...THEY
WILL BE LOCALLY VARIABLE.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MONDAY THROUGH 00Z TUESDAY...VFR EXCEPT LOCAL IFR WITH OVERNIGHT
PATCHY FOG MAINLY MPV AND SLK.
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY ONWARD...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS. SHOWERS DIMINISHING THURSDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS/MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
356 AM EDT SUN AUG 9 2015
.SYNOPSIS...
ANOTHER NICE DAY IS EXPECTED ACROSS THE NORTH COUNTRY
WITH MAINLY DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. AN ISOLATED
SHOWER OR SPRINKLE IS POSSIBLE ACROSS NORTHEAST VERMONT THIS
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE FORECASTED FOR MONDAY...BEFORE SHOWERS ARRIVE ON
MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 345 AM EDT SUNDAY...FORECAST FOCUS TODAY WILL BE CHANCE FOR
AN ISOLATED SHOWER ACROSS THE NORTHEAST KINGDOM OF VT. CRNT WATER
VAPOR SHOWS MID/UPPER LVL TROF CONTS...WITH WEAK S/W ENERGY DIVING
SOUTH FROM EASTERN CANADA. ALSO...WATER VAPOR SHOWS VERY DRY AIR
AHEAD OF THIS SYSTEM...SO ANY PRECIP CHCS TODAY WILL BE VERY
ISOLATED AND CONFINED TO THE NORTHEAST KINGDOM OR MTNS OF NORTHERN
VT. BTV 4KM IS MOST AGGRESSIVE WITH SHOWING QPF AND ASSOCIATED
COMPOSITE REFLECTIVITY RETURNS ACROSS MOST OF THE HIGHER TRRN OF VT
THIS AFTN...BUT GIVEN PROGGED SOUNDING MOISTURE PROFILES...THINKING
THIS IS OVERDONE. WL USE A BLEND OF NAM/GFS AND HRRR TO MENTION SCHC
WITH A SMALL AREA OF CHC POPS ACROSS ESSEX COUNTY VT. REST OF CWA
WILL REMAIN DRY. TEMPS WILL BE SEVERAL DEGREES WARMER THAN YESTERDAY
WITH HIGHS GENERALLY IN THE 70S TO NEAR 80F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 345 AM EDT SUNDAY...OUR NICE PERIOD OF DRY
WEATHER WILL BE COMING TO AN END BY TUESDAY...AS MID/UPPER LVL TROF
AND ASSOCIATED SFC LOW PRES IMPACT THE NE CONUS. FOR MONDAY...BEST
850 TO 500MB MOISTURE IS WEST OF OUR CWA THRU 00Z..ALONG WITH
FORCING ASSOCIATED WITH INITIAL 5H VORT. WILL CONT TO MENTION CHC
POPS TWD 00Z TUESDAY ACROSS THE SLV AND WESTERN DACKS. PROGGED 85H
TEMPS WARM BTWN 12-14C BY 18Z MONDAY...SUPPORTING M/U 70S MTN TOWNS
TO L/M 80S WARMER VALLEYS.
OVERALL...NAM/GFS AND ECMWF HAVE COME INTO PRETTY GOOD AGREEMENT
WITH HANDLING THE DEEPENING OF MID/UPPER LVL TROF ACROSS THE GREAT
LAKES AND SFC LOW PRES TRACKING FROM THE OHIO VALLEY MONDAY NIGHT
INTO THE SLV BY TUES. IN ADDITION...MODELS HAVE TRENDED SEVERAL
HOURS SLOWER WITH THE PRECIP ARRIVE ON MONDAY NIGHT INTO TUESDAY
ACROSS OUR CWA...WITH HEAVIEST QPF AXIS OF UP TO 1.0 OF RAIN
EXPECTED OVER NORTHERN NY BY TUES AFTN. LOW LEVEL FORCING/ ADVECTION
OF MOISTURE IS IMPRESSIVE ASSOCIATED WITH NOSE OF 85H JET OF 45 TO
50 KNOTS IMPACTING OUR CWA BY 12Z TUESDAY. GFS/NAM SHOW A STRONG
BAND OF 850 TO 700MB FGEN FORCING...ALONG WITH GOOD LVLL MOISTURE
CONVERGENCE LIFTING FROM SW TO NE ACRS OUR CWA BTWN 09Z AND 18Z
TUESDAY.
HAVE NOTED SOME HIGHER RESOLUTION MODELS SHOWING IMPACTS OF
SE TO SOUTHWEST WINDS ON THE ASSOCIATED QPF FIELDS WITH SOME
SHADOWING OVER THE CPV AND PARTS OF THE NEK. GIVEN THE MOISTURE FEED
WITH PWS AROUND 1.50" AND GOOD UPPER LEVEL DYNAMICS WITH APPROACHING
TROF AND HEIGHT FALLS...A WIDESPREAD RAINFALL IS VERY LIKELY LATE
MONDAY NIGHT INTO TUESDAY. WILL CONT THE TREND AND MENTION CAT POPS
ACRS OUR CWA...BUT TRRN WILL INFLUENCE QPF FIELDS....WITH HIGHEST
VALUES OF UP TO 1.0 OCCURRING ACRS THE NORTHERN NY/HIGH PEAKS
REGION...GIVEN THE LLVL JET ORIENTATION. MEANWHILE...VALUES ACROSS
VT WILL RANGE FROM 0.25 TO 0.75" WITH HIGHEST AMOUNTS ON SE UPSLOPE
AREAS OF THE GREEN MTNS.
SOUNDINGS SHOW RIDGETOP WINDS BTWN 45 AND 50 KNOTS ON TUESDAY
MORNING...BUT INVERSION LEVEL IS AROUND 2000 FT....SUPPORTING
MIXED LAYER WINDS TO THE SURFACE UP TO 35 MPH OR SO ALONG THE
WESTERN SLOPES AND HIGHER TRRN. TEMPS TUES WILL BE TRICKY WITH
1000 TO 500MB THICKNESS RIDGE OVERHEAD...BUT LOTS OF CLOUDS AND
PRECIP AROUND. THINKING A FEW BREAKS WILL DEVELOP IN MID LVL DRY
SLOT OVER THE SLV/WESTERN DACKS AND THIS AREA WILL REACH
80F...WHILE MOST OF THE OTHER SITES STAY IN THE M/U 60S MTNS TO
L/M 70S CPV/SOUTHERN VT.
A RUMBLE OF THUNDER ASSOCIATED WITH THE DYNAMICS CANNOT BE RULED
OUT ON TUESDAY MORNING...WITH ANOTHER CHC OF A RUMBLE ON TUES AFTN
IN THE WARM SECTOR OVER SLV. ALSO...NOTED WEAK ELEVATED
INSTABILITY LAYER WITH ML CAPE VALUES AROUND 400 J/KG ON MONDAY
NIGHT/TUESDAY MORNING...ASSOCIATED WITH NOSE OF 85H JET AND STRONG
LLVL WAA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 354 AM EDT SUNDAY...RATHER ACTIVE WEATHER WITH CHANCE OF
SHOWERS FOR MUCH OF THE PERIOD AS UPPER LEVEL TROUGH REMAINS OVER
THE EAST.
WEAK SURFACE BOUNDARY WILL MOVE SLOWLY EAST OF THE AREA TUESDAY
NIGHT...WITH HIGHEST PRECIPITABLE WATER VALUES SHIFTING TO THE EAST
AS WELL. UPPER LEVEL LOW LAGS BEHIND HOWEVER...SO WHILE HIGHEST
CHANCE OF SHOWERS WILL BE DURING THE EVENING...THERE WILL BE A
CONTINUED CHANCE FOR A FEW SHOWERS DURING THE OVERNIGHT AS WELL.
WITH UPPER LEVEL LOW AND ASSOCIATED COLD POOL ALOFT STILL OVER THE
REGION ON WEDNESDAY...WE CAN EXPECT MORE CLOUDS AND A CONTINUED
CHANCE OF SHOWERS. WEST TO NORTHWEST UPSLOPE FLOW WILL HELP PROVIDE
SOURCE OF LIFT FOR BETTER COVERAGE OVER THE HIGHER TERRAIN. LIMITED
INSTABILITY...BUT AN ISOLATED THUNDERSTORM ALSO POSSIBLE.
UPPER TROUGH SLOW TO DEPART THURSDAY...SO STILL CHANCE OF A FEW
SHOWERS. DRIER CONDITIONS LATER THURSDAY INTO FRIDAY MORNING WITH
SHORTWAVE RIDGING ALOFT AT 500MB. FROM FRIDAY ONWARD YET ANOTHER
UPPER LEVEL TROUGH WILL APPROACH FROM THE NORTHERN GREAT LAKES
REGION AND RE-ESTABLISH THE EASTERN US TROUGH AND A CHANCE FOR MORE
SHOWERS AND A FEW WIDELY SCATTERED STORMS.
AS FOR TEMPS...MAX TEMPS WILL AVERAGE SEVERAL DEGREES BELOW NORMAL
WITH HIGHS MAINLY IN THE 70S...PERHAPS AROUND 80 IN SPOTS FRIDAY AND
SATURDAY. MINS WILL BE IN THE 50S TO AROUND 60...GENERALLY WITHIN
A FEW DEGREES OF NORMAL FOR MID AUGUST.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR LATE TONIGHT AND EARLY SUNDAY MORNING AT
SLK/MSS/MPV. BKN HIGH CIRRUS DECK WILL PROGRESS EASTWARD
OVERNIGHT...SLOWLY CLEARING THE REGION BETWEEN THROUGH 11Z. WITH
THE CLEARING WILL COME THE POTENTIAL FOR FOG/BR DEVELOPMENT.
GREATEST LIKELIHOOD TO SEE LIFR FOG WILL BE AT SLK & MPV...WITH
THE POSSIBILITY AT MSS AS WELL. FOG/BR LIFTS BY AROUND 12Z WITH
CLEAR SKIES GIVING WAY TO A DEVELOPING CU FIELD IN THE
AFTERNOON...WITH ALL SITES VFR. WINDS LIGHT AND LOCALLY VARIABLE
OVERNIGHT (EXCEPT SE AT RUT WITH DRAINAGE WIND) BECOME GENERALLY
NORTHERLY FROM 4-7 KNOTS ON SUNDAY...BUT WITH LIGHT FLOW...THEY
WILL BE LOCALLY VARIABLE.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MONDAY THROUGH 00Z TUESDAY...VFR EXCEPT LOCAL IFR WITH OVERNIGHT
PATCHY FOG MAINLY MPV AND SLK.
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY ONWARD...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS. SHOWERS DIMINISHING THURSDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...RJS
AVIATION...RJS/MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 AM EDT SUN AUG 9 2015
.SYNOPSIS...
ANOTHER NICE DAY IS EXPECTED ACROSS THE NORTH COUNTRY
WITH MAINLY DRY CONDITIONS AND NEAR NORMAL TEMPERATURES. AN ISOLATED
SHOWER OR SPRINKLE IS POSSIBLE ACROSS NORTHEAST VERMONT THIS
AFTERNOON. OTHERWISE...DRY CONDITIONS WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES ARE FORECASTED FOR MONDAY...BEFORE SHOWERS ARRIVE ON
MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 345 AM EDT SUNDAY...FORECAST FOCUS TODAY WILL BE CHANCE FOR
AN ISOLATED SHOWER ACROSS THE NORTHEAST KINGDOM OF VT. CRNT WATER
VAPOR SHOWS MID/UPPER LVL TROF CONTS...WITH WEAK S/W ENERGY DIVING
SOUTH FROM EASTERN CANADA. ALSO...WATER VAPOR SHOWS VERY DRY AIR
AHEAD OF THIS SYSTEM...SO ANY PRECIP CHCS TODAY WILL BE VERY
ISOLATED AND CONFINED TO THE NORTHEAST KINGDOM OR MTNS OF NORTHERN
VT. BTV 4KM IS MOST AGGRESSIVE WITH SHOWING QPF AND ASSOCIATED
COMPOSITE REFLECTIVITY RETURNS ACROSS MOST OF THE HIGHER TRRN OF VT
THIS AFTN...BUT GIVEN PROGGED SOUNDING MOISTURE PROFILES...THINKING
THIS IS OVERDONE. WL USE A BLEND OF NAM/GFS AND HRRR TO MENTION SCHC
WITH A SMALL AREA OF CHC POPS ACROSS ESSEX COUNTY VT. REST OF CWA
WILL REMAIN DRY. TEMPS WILL BE SEVERAL DEGREES WARMER THAN YESTERDAY
WITH HIGHS GENERALLY IN THE 70S TO NEAR 80F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 345 AM EDT SUNDAY...OUR NICE PERIOD OF DRY
WEATHER WILL BE COMING TO AN END BY TUESDAY...AS MID/UPPER LVL TROF
AND ASSOCIATED SFC LOW PRES IMPACT THE NE CONUS. FOR MONDAY...BEST
850 TO 500MB MOISTURE IS WEST OF OUR CWA THRU 00Z..ALONG WITH
FORCING ASSOCIATED WITH INITIAL 5H VORT. WILL CONT TO MENTION CHC
POPS TWD 00Z TUESDAY ACROSS THE SLV AND WESTERN DACKS. PROGGED 85H
TEMPS WARM BTWN 12-14C BY 18Z MONDAY...SUPPORTING M/U 70S MTN TOWNS
TO L/M 80S WARMER VALLEYS.
OVERALL...NAM/GFS AND ECMWF HAVE COME INTO PRETTY GOOD AGREEMENT
WITH HANDLING THE DEEPENING OF MID/UPPER LVL TROF ACROSS THE GREAT
LAKES AND SFC LOW PRES TRACKING FROM THE OHIO VALLEY MONDAY NIGHT
INTO THE SLV BY TUES. IN ADDITION...MODELS HAVE TRENDED SEVERAL
HOURS SLOWER WITH THE PRECIP ARRIVE ON MONDAY NIGHT INTO TUESDAY
ACROSS OUR CWA...WITH HEAVIEST QPF AXIS OF UP TO 1.0 OF RAIN
EXPECTED OVER NORTHERN NY BY TUES AFTN. LOW LEVEL FORCING/ ADVECTION
OF MOISTURE IS IMPRESSIVE ASSOCIATED WITH NOSE OF 85H JET OF 45 TO
50 KNOTS IMPACTING OUR CWA BY 12Z TUESDAY. GFS/NAM SHOW A STRONG
BAND OF 850 TO 700MB FGEN FORCING...ALONG WITH GOOD LVLL MOISTURE
CONVERGENCE LIFTING FROM SW TO NE ACRS OUR CWA BTWN 09Z AND 18Z
TUESDAY.
HAVE NOTED SOME HIGHER RESOLUTION MODELS SHOWING IMPACTS OF
SE TO SOUTHWEST WINDS ON THE ASSOCIATED QPF FIELDS WITH SOME
SHADOWING OVER THE CPV AND PARTS OF THE NEK. GIVEN THE MOISTURE FEED
WITH PWS AROUND 1.50" AND GOOD UPPER LEVEL DYNAMICS WITH APPROACHING
TROF AND HEIGHT FALLS...A WIDESPREAD RAINFALL IS VERY LIKELY LATE
MONDAY NIGHT INTO TUESDAY. WILL CONT THE TREND AND MENTION CAT POPS
ACRS OUR CWA...BUT TRRN WILL INFLUENCE QPF FIELDS....WITH HIGHEST
VALUES OF UP TO 1.0 OCCURRING ACRS THE NORTHERN NY/HIGH PEAKS
REGION...GIVEN THE LLVL JET ORIENTATION. MEANWHILE...VALUES ACROSS
VT WILL RANGE FROM 0.25 TO 0.75" WITH HIGHEST AMOUNTS ON SE UPSLOPE
AREAS OF THE GREEN MTNS.
SOUNDINGS SHOW RIDGETOP WINDS BTWN 45 AND 50 KNOTS ON TUESDAY
MORNING...BUT INVERSION LEVEL IS AROUND 2000 FT....SUPPORTING
MIXED LAYER WINDS TO THE SURFACE UP TO 35 MPH OR SO ALONG THE
WESTERN SLOPES AND HIGHER TRRN. TEMPS TUES WILL BE TRICKY WITH
1000 TO 500MB THICKNESS RIDGE OVERHEAD...BUT LOTS OF CLOUDS AND
PRECIP AROUND. THINKING A FEW BREAKS WILL DEVELOP IN MID LVL DRY
SLOT OVER THE SLV/WESTERN DACKS AND THIS AREA WILL REACH
80F...WHILE MOST OF THE OTHER SITES STAY IN THE M/U 60S MTNS TO
L/M 70S CPV/SOUTHERN VT.
A RUMBLE OF THUNDER ASSOCIATED WITH THE DYNAMICS CANNOT BE RULED
OUT ON TUESDAY MORNING...WITH ANOTHER CHC OF A RUMBLE ON TUES AFTN
IN THE WARM SECTOR OVER SLV. ALSO...NOTED WEAK ELEVATED
INSTABILITY LAYER WITH ML CAPE VALUES AROUND 400 J/KG ON MONDAY
NIGHT/TUESDAY MORNING...ASSOCIATED WITH NOSE OF 85H JET AND STRONG
LLVL WAA.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 247 PM EDT SATURDAY...RATHER ACTIVE IF NOT SOGGY WEATHER
FOR MUCH OF THE EXTENDED PERIOD AS FLOW AT 500MB EVOLVES INTO A
HIGH AMPLITUDE TROUGH IN THE EAST.
FORECAST MODELS COMING MORE IN LINE WITH EACH OTHER WITH UPPER
TROUGH SETTLING IN ACROSS THE NORTHEAST AND SURFACE LOW SLOWLY
MOVING THROUGH THE AREA DURING THE DAY TUESDAY. AREA OF SHOWERS
ALONG AND AHEAD OF THE FRONT WILL SLOW MOVE WEST TO EAST. SMALL
CHANCE FOR SOME THUNDER WITH SURFACE BASED CAPE 150-200 J/KG, AND
THUNDER MENTION IN THE FORECAST IS SECONDARY TO RAIN. PRECIPITABLE
WATER INCREASES OVER 1.5 INCHES IN THE SOUTHERLY FLOW AHEAD OF THE
FRONT...AND MOST MODEL GUIDANCE SHOWS AROUND .50 TO .75 INCH OF
RAIN DURING THE DAY ON TUESDAY. NOT A HYDRO THREAT BUT WILL BE A
WET DAY.
TUESDAY NIGHT INTO WEDNESDAY THE WEAK SURFACE BOUNDARY MOVES EAST
OF THE REGION...BUT UPPER LOW LAGS BEHIND. COLD POOL ALOFT WILL BE
OVER THE AREA WEDNESDAY PROVIDING INSTABILITY TO GENERATE
ADDITIONAL SHOWERS, AND WEST TO NORTHWEST UPSLOPE FLOW WILL HELP
PROVIDE SOURCE OF LIFT FOR BETTER COVERAGE OVER THE HIGHER
TERRAIN. UPPER TROUGH SLOW TO DEPART THURSDAY...SO STILL CHANCE OF
A FEW SHOWERS. SHORTWAVE RIDGING ALOFT AT 500MB, SO IF THERE IS
ANY TIME WHEN IT SHOULDN`T RAIN WILL BE LATE THURSDAY INTO EARLY
FRIDAY. FROM FRIDAY ONWARD YET ANOTHER UPPER LEVEL TROUGH WILL
APPROACH FROM THE NORTHERN GREAT LAKES REGION AND RE- ESTABLISH
THE EASTERN US TROUGH AND A CHANCE FOR MORE SHOWERS.
AS FOR TEMPS...MAX TEMPS WILL AVERAGE SEVERAL DEGREES BELOW
NORMAL WITH HIGHS MAINLY IN THE 70S. MINS WILL BE ABOVE NORMAL
EARLY IN THE PERIOD WITH READINGS IN THE UPPER 50S TO MID
60S...THEN RETURN TO NEAR SEASONAL WITH LOWS MAINLY IN THE 50S.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR LATE TONIGHT AND EARLY SUNDAY MORNING AT
SLK/MSS/MPV. BKN HIGH CIRRUS DECK WILL PROGRESS EASTWARD
OVERNIGHT...SLOWLY CLEARING THE REGION BETWEEN THROUGH 11Z. WITH
THE CLEARING WILL COME THE POTENTIAL FOR FOG/BR DEVELOPMENT.
GREATEST LIKELIHOOD TO SEE LIFR FOG WILL BE AT SLK & MPV...WITH
THE POSSIBILITY AT MSS AS WELL. FOG/BR LIFTS BY AROUND 12Z WITH
CLEAR SKIES GIVING WAY TO A DEVELOPING CU FIELD IN THE
AFTERNOON...WITH ALL SITES VFR. WINDS LIGHT AND LOCALLY VARIABLE
OVERNIGHT (EXCEPT SE AT RUT WITH DRAINAGE WIND) BECOME GENERALLY
NORTHERLY FROM 4-7 KNOTS ON SUNDAY...BUT WITH LIGHT FLOW...THEY
WILL BE LOCALLY VARIABLE.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MONDAY THROUGH 00Z TUESDAY...VFR EXCEPT LOCAL IFR WITH OVERNIGHT
PATCHY FOG MAINLY MPV AND SLK.
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY ONWARD...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS. SHOWERS DIMINISHING THURSDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...HANSON
AVIATION...RJS/MUCCILLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1039 PM EDT MON AUG 10 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TUESDAY AND MAY EXTEND INTO WEDNESDAY
AS A COLD FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT WEDNESDAY...OFFERING SEASONABLE
AND MAINLY DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY
RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS
MOISTURE ONSHORE.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 1030 PM MONDAY...TRIMMED BACK FORECAST SHOWER CHANCES A
LITTLE MORE AS ONLY A FEW SPOTTY RETURNS ARE NOTED UPSTREAM ON
RADAR ACROSS SOUTH CAROLINA. THE HEAVIER ACTIVITY WHICH AFFECTED
THE CHARLOTTE/LAKE NORMAN AREA EARLIER THIS EVENING IS TAKING OFF
TO THE NE ACROSS ASHEBORO/BURLINGTON AND WILL MISS MY FORECAST
AREA WELL TO THE NORTH. THE MODELS WHICH SEEM TO HAVE A GOOD
HANDLE ON THE EASTERN EDGE OF THE PRECIP INCLUDE THE 12Z
ECMWF...00Z NAM...AND 12Z NMM-ARW. NO SIGNIFICANT CHANGES HAVE
BEEN MADE TO TEMPERATURES. DISCUSSION FROM 300 PM FOLLOWS...
CLOUD COVER HAS BEEN PRETTY EXTENSIVE ACROSS THE INLAND HALF OF
THE CWA...BUT COASTAL SECTIONS HAVE ONCE AGAIN EXPERIENCED A GREAT
EARLY-AUGUST DAY. MOISTURE WILL CONTINUE TO INCREASE IN BOTH THE
MID-LEVELS AND AT THE SURFACE...FINALLY OVERCOMING THE VERY DRY
AIR IN PLACE AS THE SURFACE RIDGE OVERHEAD SHIFTS OFFSHORE.
SHOWERS THAT HAD DEVELOPED WEST OF THE CWA HAVE ERODED AS EXPECTED
THANKS TO ENCOUNTERING DRY AIR...AND HIGH RES GUIDANCE INCLUDING
THE HRRR AND NSSL WRF BOTH KEEP THE CWA DRY THROUGH TONIGHT. HAVE
REMOVED MENTION OF POP FROM EVEN IN THE FAR INLAND ZONES THROUGH
DARK TO ACCOUNT FOR TRENDS IN SATELLITE AND RADAR.
TONIGHT...COLUMN SATURATION WILL CONTINUE TO INCREASE WITH PWATS
RISING TOWARDS 2 INCHES BY TUESDAY MORNING. COLD FRONT APPROACHING
FROM THE WEST WILL BE NEAR THE CWA BY MORNING...WITH SHOWERS AND
THUNDERSTORMS INCREASING AHEAD OF IT. FORECAST PROFILES SUGGEST
ENOUGH SATURATION INLAND THAT POP HAS BEEN RAMPED UP TO HIGH CHC
FROM I-95 WESTWARD BY 8AM TUESDAY...WITH JUST SCHC ALONG THE
COAST...BUT MOST OF THE PRECIP WILL HOLD OFF UNTIL AFTER THIS PERIOD.
INCREASING CLOUD COVER AND CONTINUED LIGHT SOUTHERLY WINDS WILL KEEP
MINS ELEVATED TO ABOVE SEASONABLE NORMS TONIGHT. THE MAV AND MET ARE
IN GOOD AGREEMENT...AND HAVE FORECAST MORE CLOSELY TO THE SLIGHTLY
WARMER MAV NUMBERS. EXPECT LOWS IN THE 72-75 DEGREE RANGE THROUGHOUT
THE AREA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE PRIME WEATHER CAPTION FOR TUE/WED IS RAIN
AS AN APPROACHING FRONTAL SYSTEM WITH RELATIVELY HIGH AMOUNTS OF
INGESTED PRECIPITABLE WATER...CROSSES THE APPALACHIAN MOUNTAINS
EARLY TUESDAY AND MOVES TO THE COAST TUESDAY NIGHT. IT APPEARS A
WEAK WAVE OF LOW PRESSURE MOVING NNE ALONG THE FRONT MAY SUSTAIN
ISOLATED COASTAL SHOWERS SLIGHTLY BEHIND THE DECAYING FRONTAL SYSTEM
ON WEDNESDAY. BEST FIT AND CONSENSUS QPF DEPICTIONS OF STORM/SYSTEM
TOTAL POINTS GENERALLY TO 0.50-0.75 INCHES OF RAIN TUE/WED AND
HIGHEST ALONG AREAS IN PROXIMITY TO THE COAST. A TREND OF DRYING
WILL PREVAIL ON WEDNESDAY ESPECIALLY INLAND...IN THE FACE OF
ISOLATED COASTAL SHOWERS.
POST-FRONTAL DOWNSLOPE WIND FLOW WEDNESDAY WITH LITTLE COLD AIR
ADVECTION WILL LIKELY RESULT IN A SEASONABLY WARM DAY WEDNESDAY
ALTHOUGH WE WILL OBSERVE SEVERAL DEGREES OF DEWPOINT DROPS THROUGH
WEDNESDAY...TAKING A SLIGHT EDGE OFF THE HUMIDITY LEVELS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING WILL PERSIST ACROSS THE
EAST/SOUTHEAST THROUGH SATURDAY WITH MORE OF A ZONAL PATTERN
DEVELOPING THEREAFTER. GENERALLY QUIET WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES FROM THE MIDWEST TO THE APPALACHIANS THROUGH THE
PERIOD. THE HIGH WILL WEAKEN WITH THE MID LEVEL TROUGH THUS LEAVING
A WEAK PRESSURE PATTERN BOTH AT THE SURFACE AND ALOFT. HAVE
CONTINUED THE SLIGHT CHANCE POPS WHICH ARE MOSTLY CONFINED TO THE
COASTAL AND OFFSHORE ZONES. THE TEMPERATURE CURVE FOLLOWS THE SAME
PROGRESSION WITH COOL READINGS EARLY ON...FRIDAY SHOULD BE THE
COOLEST WITH 850MB TEMPERATURES NEAR 15 DEGREES C. THERMAL PROFILES
SLOWLY MODIFY FROM THAT POINT ON. READINGS MAY ECLIPSE CLIMATOLOGY
JUST BY A DEGREE OR TWO BY THE END OF THE PERIOD.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...OUTSIDE OF CONVECTIVE DEBRIS...SHOULD BE A QUIET NIGHT
NIGHT WITH MAINLY VFR CONDITIONS EXPECTED. AFT 12Z...SHOWERS SHOULD
BE ON THE INCREASE AS A COLD FRONT APPROACHES. TERMINALS MAINTAIN VFR
CONDITIONS THROUGH 18Z WITH VCSH WITH SCT SHRA IN THE AREA. AFT 18Z...
ALL TERMINALS SHOWING PROB30 FOR TSRA WITH MVFR CIGS DUE TO FRONTAL
LIFT AND INSTABILITY. SHORT DURATION IFR IS POSSIBLE WITH TSRA BUT
CONFIDENCE IN EXACT TIMING AT EACH TERMINAL IS LOW ATTM.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND STORMS TUESDAY NIGHT WITH
INTERMITTENT MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY WITH
ISOLATED MORNING CONVECTION POSSIBLE. VFR THURSDAY THROUGH
SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM MONDAY...WINDS ARE QUITE A BIT STRONGER AT THE
BEACHES THAN THEY ARE WAY OUT AT THE FRYING PAN SHOALS BUOY. THIS
IS ACTUALLY EXPECTED AS A WEAKER PRESSURE GRADIENT EXISTS
OFFSHORE NEAR THE HIGH PRESSURE RIDGE. MODELS REMAIN IN GOOD
AGREEMENT ABOUT GRADUALLY BUILDING WIND SPEEDS AS THE RIDGE SCOOTS
OUT TO THE SEAS. SEAS ARE CURRENTLY 2 FEET...BUT WON`T BEGIN TO
BUILD UNTIL AFTER DAYBREAK. DISCUSSION FROM 300 PM FOLLOWS...
WEAK RIDGE OF HIGH PRESSURE WILL SLOWLY SHIFT OFFSHORE
TONIGHT...SO ALTHOUGH THE GRADIENT WILL REMAIN LIGHT KEEPING WIND
SPEEDS TO 10 KTS OR LESS...DIRECTION WILL CONTINUE TO VEER THROUGH
TONIGHT...FROM CURRENT ESE ALL THE WAY TO SSW LATE. CURRENT BUOY
OBS SHOW A MIX OF 5 SEC AND 10 SEC WAVES...WITH THE 10 SEC WAVE
DOMINANT DUE TO THE LIGHT WINDS...AND THESE WILL PERSIST THROUGH
THE PERIOD MAINTAINING WAVE HEIGHTS OF 2-3 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...MAIN MARINE HEADLINE THIS PERIOD REMAINS
APPROACH AND DECAY OF A COLD FRONTAL SYSTEM OVER THE COASTAL
WATERS DURING THE DAY WEDNESDAY. THIS MAY BRING A BRIEF PERIOD
OF N-NW WINDS WEDNESDAY...PRECEDED BY COASTAL RAIN SHOWERS AND
ISOLATED TSTMS TUESDAY NIGHT. A FEW TSTMS MAY IMPACT THE OUTER
WATERS ON WEDNESDAY AS WELL SINCE THE FRONT MAY SLOWLY DISSIPATE
THERE MID-WEEK. SEAS WILL BUILD TO 3-4 FT TUESDAY NIGHT AHEAD OF
THE COLD FRONT IN 15-20 KT SW WINDS...POSSIBLY 5 FT VERY OUTER
PORTION. SEAS SETTLING TO 2-3 FT WED AFTN AND EVENING AS WIND
SPEEDS GO LIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE WILL MOVE FROM THE MIDWEST TO THE
APPALACHIANS THROUGH THE PERIOD. THE HIGH WILL SLOWLY WEAKEN LEAVING
A BENIGN PRESSURE PATTERN BY SATURDAY. FOR THURSDAY AND FRIDAY
WINDS WONT BE OVERWHELMING AND EXPECT A EAST/NORTHEAST DIRECTION IN
A RANGE OF 10-15 KNOTS...MOSTLY HOVERING IN THE LOWER END OF THE
RANGE. SPEEDS DROP TO TEN KNOTS AND BELOW BY SATURDAY. SIGNIFICANT
SEAS WILL BE 1-3 FEET WITH AN EQUAL MIX OF A SHORTER PERIOD WIND
WAVE AND SWELL COMPONENT.
&&
.EQUIPMENT...
AS OF 130 PM MONDAY...POWER TO THE ILM ASOS HAS BEEN LOST DUE TO
A POWER SURGE. A REPLACEMENT IS ON ORDER...BUT IT IS LIKELY THAT
ILM ASOS WILL BE WITHOUT AUTOMATED OBSERVATIONS THROUGH TODAY AND
PART OF TUESDAY. THE ILM TOWER SHOULD AMEND OBSERVATIONS UNTIL 11
PM TONIGHT...AND RESUME EARLY TUESDAY MORNING. OVERNIGHT OBS MAY
WILL BE MISSING FOR ALL PARAMETERS. AMD NOT SKED HAS BEEN APPENDED
TO THE ILM TAF AND WILL REMAIN AS SUCH UNTIL POWER IS RESTORED TO
THE SITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA/JDW
SHORT TERM...MBB
LONG TERM...SHK
AVIATION...RAN
EQUIPMENT...JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
935 PM EDT MON AUG 10 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY...
AND PUSH SOUTHEAST THROUGH THE AREA LATE TUESDAY THROUGH TUESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 PM MONDAY...
WATER VAPOR IMAGERY AND RAP 500MB VORT ANALYSIS SHOW SEVERAL
DISTURBANCES ALOFT THAT CONTINUE TO SUPPORT BROKEN BANDS OF MOSTLY
WEAK CONVECTION FROM WESTERN VIRGINIA SOUTH INTO GEORGIA AND
ALABAMA. LOCALLY...A BRIEF PERIOD OF HEATING/DESTABILIZATION OVER
THE WESTERN PIEDMONT AND THE DEVELOPMENT OF SOME MODERATE DCAPE
EARLIER THIS AFTERNOON ALSO APPEARS TO BE SUPPORTING A DISORGANIZED
COLD POOL AND SLOWLY WEAKENING SHOWERS/STORMS FROM THE TRIAD TO NEAR
ALBEMARLE. NOCTURNAL COOLING WILL FAVOR A CONTINUED WEAKENING OF
THIS CONVECTION...BUT RAP FORECAST SOUNDINGS SHOW A 35-40KT LOW
LEVEL JET FROM CLT TO RDU AFTER MIDNIGHT THAT MAY HELP TO TAP
WHATEVER WEAK MUCAPE IS LEFT AND MAINTAIN SOME SCATTERED SHOWERS.
THIS IS LOOSELY SUPPORTED BY RECENT HRRR RUNS. THE FORECAST UPDATE
WILL HAVE A CHANCE POP OVERNIGHT BECOMING INCREASINGLY FOCUSED TO
THE EAST TOWARD 12Z. OTHERWISE...REGIONAL SATELLITE IMAGERY SHOWS
PLENTY OF CONVECTIVE DEBRIS CLOUDINESS AND SKIES MOSTLY CLOUDY FOR A
MAJORITY OF THE AREA. LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
STILL APPEARS TO BE THE WETTEST DAY... WITH ALL LARGE-SCALE MODELS
INCLUDING THE SREF MEAN INDICATING NUMEROUS SHOWERS AND STORMS...
ALTHOUGH DETAILS OF THE TIMING AND WHAT LOCATIONS WILL SEE THE
GREATEST AMOUNTS AND COVERAGE ARE STILL MURKY. FALLING MID LEVEL
HEIGHTS WITH THE DIGGING TROUGH ALONG WITH MID LEVEL DPVA...
INCREASING UPPER DIVERGENCE ASSOCIATED WITH A STRENGTHENING JET
STREAK OVER IA/IL... AND DECENT LOW LEVEL MOISTURE TRANSPORT WILL
WORK WITH 1000-2000 J/KG OF MUCAPE (ON THE GFS... ALTHOUGH THIS MAY
BE OVERDONE GIVEN EXTENSIVE MORNING CLOUD COVER) AND IMPROVING DEEP
LAYER SHEAR OF 25-30 KT TO FORCE SHOWERS AND STORMS... PEAKING
DURING THE AFTERNOON INTO MID EVENING... AHEAD OF THE APPROACHING
SURFACE COLD FRONT. THE SEVERE THREAT STILL LOOKS MARGINAL... GIVEN
THAT THE BETTER DYNAMIC FORCING FOR ASCENT SHOULD BE JUST TO OUR
NORTH AND NE ALONG THE MIDATLANTIC COAST WITH THE BETTER
INSTABILITY/SHEAR COMBINATION TO OUR SOUTH AND SW OVER UPSTATE SC
AND GA... BUT A FEW DAMAGING WIND REPORTS ARE STILL POSSIBLE IN THIS
INCREASINGLY VOLATILE ENVIRONMENT. EXPECT HIGHS MOSTLY IN THE MID
80S. POPS SHOULD LOWER FROM NW TO SE TUE NIGHT... TRENDING DOWN TO
JUST A SLIGHT CHANCE IN THE SE BY LATE TUE NIGHT. LOWS 65-70. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
THE MAIN FRONT WILL SHIFT OFFSHORE ON WEDNESDAY...WITH GENERAL UPPER
LEVEL TROUGHINESS LINGERING OVER THE CAROLINAS THROUGH MONDAY. AT
THE SURFACE...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
REMAIN OVERHEAD THROUGH MONDAY. WITH THAT IN MIND...MOST OF THE
EXTENDED PERIOD WILL REMAIN DRY...WITH JUST A SLIGHT CHANCE FOR
SHOWERS OVER THE WESTERN HALF OF THE STATE OVER THE WEEKEND.
TEMPERATURES DURING THE PERIOD WILL FEATURE HIGHS IN THE MID 80S TO
AROUND 90 DEGREES WITH OVERNIGHT LOWS GENERALLY IN THE MID 60S.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 756 PM MONDAY...
TONIGHT: CONVECTION THAT DEVELOPED OVER THE SOUTHERN APPALACHIANS
EARLIER THIS AFTERNOON (18-21Z) HAS BEEN DRIFTING EASTWARD VIA A
LIGHT WESTERLY STEERING FLOW. THIS ACTIVITY HAS ALREADY PROGRESSED
EAST OF THE I-77 CORRIDOR AND WILL AFFECT THE INT/GSO TERMINALS
BETWEEN 00-03Z. NOCTURNAL COOLING IN THE PRESENCE OF AN AIRMASS THAT
BECOMES INCREASINGLY STABLE WITH EASTWARD EXTENT SHOULD LARGELY
PRECLUDE A POTENTIAL FOR CONVECTION AT EASTERN TERMINALS
(RDU/FAY/RWI) OVERNIGHT. UPSTREAM CONVECTION IN NORTHERN GA/UPSTATE
SC (ASSOC/W AN UPPER DISTURBANCE) IS EXPECTED TO DECREASE IN
COVERAGE/INTENSITY AND REMAIN SOUTH OF THE CENTRAL NC TERMINALS AS
IT TRACKS TOWARD THE SC COAST.
TUESDAY: MVFR/IFR CEILINGS WILL BE POSSIBLE AT THE INT/GSO TERMINALS
TUE MORNING (08-16Z). CONVECTION WILL AFFECT ALL TERMINALS AT SOME
POINT DURING THE DAY TUE...PRIMARILY IN THE AFTERNOON...AS A COLD
FRONT APPROACHES THE MOUNTAINS FROM THE NW AND A PRE-FRONTAL TROUGH
SETTLES INTO CENTRAL NC.
WEDNESDAY-SATURDAY: VFR CONDITIONS WILL PREVAIL IN THE WAKE OF THE
COLD FRONTAL PASSAGE TUE NIGHT. -VINCENT
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/22
SHORT TERM...HARTFIELD
LONG TERM...RAH
AVIATION...VINCENT
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
741 PM EDT MON AUG 10 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TUESDAY AND EXTEND INTO WEDNESDAY AS
A COLD FRONT MAKES ITS WAY INTO THE AREA. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT LATE WEDNESDAY...OFFERING SEASONABLE
AND MAINLY DRY CONDITIONS INTO NEXT WEEKEND. A CHANCE OF RAIN
MAY RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND
DIRECTS MOISTURE ONSHORE.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 730 PM MONDAY...CHANGES WITH THIS EARLY EVENING UPDATE
INCLUDE SLOWING DOWN THE ARRIVAL OF PRECIPITATION CHANCES ACROSS
THE I-95 CORRIDOR TO THE 04Z-07Z TIMEFRAME. OF THE 12Z/18Z MODEL
SUITE ONLY A FEW MEMBERS ACTUALLY HAVE ANY QPF EAST I-95 THROUGH
12Z...SO I HAVE REMOVED POPS ENTIRELY TONIGHT FOR THE COASTAL
COUNTIES. (RAIN CHANCES SHOULD STILL RAMP UP AT THE COAST LATER TUESDAY
MORNING/AFTERNOON)
FAIRLY LARGE CHANGES HAVE BEEN MADE TO LOW TEMPERATURE FORECASTS
TO INCREASE LOWS TO 80-81 DEGREES OVER THE OCEAN AND RIGHT UP TO
THE BEACHES. THIS SHOULD MIRROR THE SITUATION WE SAW LAST NIGHT
WHERE ONSHORE FLOW PRODUCES A LARGE THERMAL GRADIENT BETWEEN
ITSELF AND THE TYPICAL INLAND NOCTURNAL INVERSION AROUND ~1 MILE
OF THE COASTLINE. (SEE THE VAST DIFFERENCE IN CRE TO MYR LOW TEMPS
LAST NIGHT!) DISCUSSION FROM 300 PM FOLLOWS...
CLOUD COVER HAS BEEN PRETTY EXTENSIVE ACROSS THE INLAND HALF OF
THE CWA...BUT COASTAL SECTIONS HAVE ONCE AGAIN EXPERIENCED A GREAT
EARLY-AUGUST DAY. MOISTURE WILL CONTINUE TO INCREASE IN BOTH THE
MID-LEVELS AND AT THE SURFACE...FINALLY OVERCOMING THE VERY DRY
AIR IN PLACE AS THE SURFACE RIDGE OVERHEAD SHIFTS OFFSHORE.
SHOWERS THAT HAD DEVELOPED WEST OF THE CWA HAVE ERODED AS EXPECTED
THANKS TO ENCOUNTERING DRY AIR...AND HIGH RES GUIDANCE INCLUDING
THE HRRR AND NSSL WRF BOTH KEEP THE CWA DRY THROUGH TONIGHT. HAVE
REMOVED MENTION OF POP FROM EVEN IN THE FAR INLAND ZONES THROUGH
DARK TO ACCOUNT FOR TRENDS IN SATELLITE AND RADAR.
TONIGHT...COLUMN SATURATION WILL CONTINUE TO INCREASE WITH PWATS
RISING TOWARDS 2 INCHES BY TUESDAY MORNING. COLD FRONT APPROACHING
FROM THE WEST WILL BE NEAR THE CWA BY MORNING...WITH SHOWERS AND
THUNDERSTORMS INCREASING AHEAD OF IT. FORECAST PROFILES SUGGEST
ENOUGH SATURATION INLAND THAT POP HAS BEEN RAMPED UP TO HIGH CHC
FROM I-95 WESTWARD BY 8AM TUESDAY...WITH JUST SCHC ALONG THE
COAST...BUT MOST OF THE PRECIP WILL HOLD OFF UNTIL AFTER THIS PERIOD.
INCREASING CLOUD COVER AND CONTINUED LIGHT SOUTHERLY WINDS WILL KEEP
MINS ELEVATED TO ABOVE SEASONABLE NORMS TONIGHT. THE MAV AND MET ARE
IN GOOD AGREEMENT...AND HAVE FORECAST MORE CLOSELY TO THE SLIGHTLY
WARMER MAV NUMBERS. EXPECT LOWS IN THE 72-75 DEGREE RANGE THROUGHOUT
THE AREA.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE PRIME WEATHER CAPTION FOR TUE/WED IS RAIN
AS AN APPROACHING FRONTAL SYSTEM WITH RELATIVELY HIGH AMOUNTS OF
INGESTED PRECIPITABLE WATER...CROSSES THE APPALACHIAN MOUNTAINS
EARLY TUESDAY AND MOVES TO THE COAST TUESDAY NIGHT. IT APPEARS A
WEAK WAVE OF LOW PRESSURE MOVING NNE ALONG THE FRONT MAY SUSTAIN
ISOLATED COASTAL SHOWERS SLIGHTLY BEHIND THE DECAYING FRONTAL SYSTEM
ON WEDNESDAY. BEST FIT AND CONSENSUS QPF DEPICTIONS OF STORM/SYSTEM
TOTAL POINTS GENERALLY TO 0.50-0.75 INCHES OF RAIN TUE/WED AND
HIGHEST ALONG AREAS IN PROXIMITY TO THE COAST. A TREND OF DRYING
WILL PREVAIL ON WEDNESDAY ESPECIALLY INLAND...IN THE FACE OF
ISOLATED COASTAL SHOWERS.
POST-FRONTAL DOWNSLOPE WIND FLOW WEDNESDAY WITH LITTLE COLD AIR
ADVECTION WILL LIKELY RESULT IN A SEASONABLY WARM DAY WEDNESDAY
ALTHOUGH WE WILL OBSERVE SEVERAL DEGREES OF DEWPOINT DROPS THROUGH
WEDNESDAY...TAKING A SLIGHT EDGE OFF THE HUMIDITY LEVELS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING WILL PERSIST ACROSS THE
EAST/SOUTHEAST THROUGH SATURDAY WITH MORE OF A ZONAL PATTERN
DEVELOPING THEREAFTER. GENERALLY QUIET WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES FROM THE MIDWEST TO THE APPALACHIANS THROUGH THE
PERIOD. THE HIGH WILL WEAKEN WITH THE MID LEVEL TROUGH THUS LEAVING
A WEAK PRESSURE PATTERN BOTH AT THE SURFACE AND ALOFT. HAVE
CONTINUED THE SLIGHT CHANCE POPS WHICH ARE MOSTLY CONFINED TO THE
COASTAL AND OFFSHORE ZONES. THE TEMPERATURE CURVE FOLLOWS THE SAME
PROGRESSION WITH COOL READINGS EARLY ON...FRIDAY SHOULD BE THE
COOLEST WITH 850MB TEMPERATURES NEAR 15 DEGREES C. THERMAL PROFILES
SLOWLY MODIFY FROM THAT POINT ON. READINGS MAY ECLIPSE CLIMATOLOGY
JUST BY A DEGREE OR TWO BY THE END OF THE PERIOD.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
AS OF 00Z...OUTSIDE OF CONVECTIVE DEBRIS...SHOULD BE A QUIET NIGHT
NIGHT WITH MAINLY VFR CONDITIONS EXPECTED. AFT 12Z...SHOWERS SHOULD
BE ON THE INCREASE AS A COLD FRONT APPROACHES. TERMINALS MAINTAIN VFR
CONDITIONS THROUGH 18Z WITH VCSH WITH SCT SHRA IN THE AREA. AFT 18Z...
ALL TERMINALS SHOWING PROB30 FOR TSRA WITH MVFR CIGS DUE TO FRONTAL
LIFT AND INSTABILITY. SHORT DURATION IFR IS POSSIBLE WITH TSRA BUT
CONFIDENCE IN EXACT TIMING AT EACH TERMINAL IS LOW ATTM.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND STORMS TUESDAY NIGHT WITH
INTERMITTENT MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY WITH
ISOLATED MORNING CONVECTION POSSIBLE. VFR THURSDAY THROUGH
SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 730 PM MONDAY...NO SIGNIFICANT CHANGES HAVE BEEN MADE TO
FORECAST WINDS AND SEAS TONIGHT. TEMPERATURE FORECASTS HAVE BEEN
BOOSTED BY UP TO 8 DEGREES AS ONSHORE WINDS SHOULD KEEP THE
MARINE ENVIRONMENT QUITE WARM OVERNIGHT. DISCUSSION FROM 300 PM
FOLLOWS...
WEAK RIDGE OF HIGH PRESSURE WILL SLOWLY SHIFT OFFSHORE
TONIGHT...SO ALTHOUGH THE GRADIENT WILL REMAIN LIGHT KEEPING WIND
SPEEDS TO 10 KTS OR LESS...DIRECTION WILL CONTINUE TO VEER THROUGH
TONIGHT...FROM CURRENT ESE ALL THE WAY TO SSW LATE. CURRENT BUOY
OBS SHOW A MIX OF 5 SEC AND 10 SEC WAVES...WITH THE 10 SEC WAVE
DOMINANT DUE TO THE LIGHT WINDS...AND THESE WILL PERSIST THROUGH
THE PERIOD MAINTAINING WAVE HEIGHTS OF 2-3 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...MAIN MARINE HEADLINE THIS PERIOD REMAINS
APPROACH AND DECAY OF A COLD FRONTAL SYSTEM OVER THE COASTAL
WATERS DURING THE DAY WEDNESDAY. THIS MAY BRING A BRIEF PERIOD
OF N-NW WINDS WEDNESDAY...PRECEDED BY COASTAL RAIN SHOWERS AND
ISOLATED TSTMS TUESDAY NIGHT. A FEW TSTMS MAY IMPACT THE OUTER
WATERS ON WEDNESDAY AS WELL SINCE THE FRONT MAY SLOWLY DISSIPATE
THERE MID-WEEK. SEAS WILL BUILD TO 3-4 FT TUESDAY NIGHT AHEAD OF
THE COLD FRONT IN 15-20 KT SW WINDS...POSSIBLY 5 FT VERY OUTER
PORTION. SEAS SETTLING TO 2-3 FT WED AFTN AND EVENING AS WIND
SPEEDS GO LIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE WILL MOVE FROM THE MIDWEST TO THE
APPALACHIANS THROUGH THE PERIOD. THE HIGH WILL SLOWLY WEAKEN LEAVING
A BENIGN PRESSURE PATTERN BY SATURDAY. FOR THURSDAY AND FRIDAY
WINDS WONT BE OVERWHELMING AND EXPECT A EAST/NORTHEAST DIRECTION IN
A RANGE OF 10-15 KNOTS...MOSTLY HOVERING IN THE LOWER END OF THE
RANGE. SPEEDS DROP TO TEN KNOTS AND BELOW BY SATURDAY. SIGNIFICANT
SEAS WILL BE 1-3 FEET WITH AN EQUAL MIX OF A SHORTER PERIOD WIND
WAVE AND SWELL COMPONENT.
&&
.EQUIPMENT...
AS OF 130 PM MONDAY...POWER TO THE ILM ASOS HAS BEEN LOST DUE TO
A POWER SURGE. A REPLACEMENT IS ON ORDER...BUT IT IS LIKELY THAT
ILM ASOS WILL BE WITHOUT AUTOMATED OBSERVATIONS THROUGH TODAY AND
PART OF TUESDAY. THE ILM TOWER SHOULD AMEND OBSERVATIONS UNTIL 11
PM TONIGHT...AND RESUME EARLY TUESDAY MORNING. OVERNIGHT OBS MAY
WILL BE MISSING FOR ALL PARAMETERS. AMD NOT SKED HAS BEEN APPENDED
TO THE ILM TAF AND WILL REMAIN AS SUCH UNTIL POWER IS RESTORED TO
THE SITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...TRA/JDW
SHORT TERM...MBB
LONG TERM...SHK
AVIATION...RAN
EQUIPMENT...JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
215 PM EDT SUN AUG 9 2015
.SYNOPSIS...WEAK HIGH PRESSURE WILL EXTEND INTO THE REGION THROUGH
TONIGHT. A WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY. A
COLD FRONT WILL SWEEP THROUGH THE REGION TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM SUNDAY...
BAND OF LIGHT SHOWERS ORIENTED NNW TO SSE WHICH DROPPED SSE THROUGH
THE NRN PIEDMONT EARLIER THIS MORNING HAS PUSHED INTO THE SANDHILLS
WHILE DIMINISHING IN COVERAGE. THE SUBTLE FORCING DRIVING THIS
FEATURE INCLUDING WEAK LOW LEVEL MASS CONVERGENCE ALONG THE LEADING
EDGE OF AN 850 MB MOISTURE BOUNDARY APPEARS TO BE DWINDLING... AND
WITH THE DEPARTURE OF A WEAKENING MID LEVEL WAVE/MCV BY AFTERNOON...
THIS SHOULD CONTINUE TO FALL APART SLOWLY. MODELS SHOW MOUNTAIN
CONVECTION FORMING THIS AFTERNOON... AND THE MEAN FLOW PATTERN WOULD
SUPPORT SOME OF THIS ACTIVITY SLIPPING SE INTO THE FAR WRN PIEDMONT
AFTER SUNSET... SO WILL RETAIN LOW CHANCE POPS LATER TONIGHT. PATCHY
MOISTURE IS EXPECTED TO PERSIST AT 700 MB WITH WEAK FLOW... SO
EXPECT GENERALLY PARTLY CLOUDY SKIES AREAWIDE TODAY ESPECIALLY AS WE
APPROACH PEAK MIXING... WITH SHORTER PERIODS OF MOSTLY CLOUDY SKIES.
OBSERVED TRENDS AND HI-RES GUIDANCE SUPPORT HIGHS OF 85-90...
ASSUMING ENOUGH BREAKS IN THE CLOUDS FOR SUFFICIENT INSOLATION. -GIH
EARLIER DISCUSSION FROM 250 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE CENTERED OVER THE MID ATLANTIC REGION AS LOW PRESSURE
OFF THE VA COAST MOVES AWAY FROM THE REGION. SATELLITE IMAGERY SHOWS
A REGION OF SCT TO MOSTLY BKN LOW/MID CLOUDS FROM CENTRAL PA
SOUTHWARD TO WESTERN NC. THESE CLOUDS HAVE BEEN EXPANDING SOUTHWARD
AND ARE ASSOCIATED WITH A REGION OF ENHANCED MOISTURE AND WEAK
ISENTROPIC UPGLIDE ABOUT THE 305K SURFACE. REGIONAL RADAR SHOWS A
FEW SHOWERS JUST NORTH OF THE TRIAD IN FAR NORTHERN NC AND
SOUTHWESTERN VA. EARLIER RUNS OF THE HRRR INDICATED THESE SHOWERS
COULD PUSH SOUTHEAST TOWARD THE TRIANGLE AREA BUT THE LAST RUN OR
TWO HAVE BACKED OFF THIS SCENARIO. WILL INCLUDE A SLIGHT CHANCE OF A
SHOWER FOR A SMALL AREA IN THE TRIAD FOR THE NEXT FEW HOURS AS THESE
SPRINKLES/SHOWERS MOVE SOUTHEAST AND LIKELY DISSIPATE.
THE REMAINDER OF TODAY SHOULD FEATURE FAIR WEATHER WITH PARTLY
CLOUDY SKIES FEATURING MULTIPLE CLOUD LAYERS. LITTLE FORCING FOR
ASCENT AND PRECIPITATION IS AVAILABLE ACROSS CENTRAL NC. ISOLATED TO
SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE NC MOUNTAINS THIS
AFTERNOON. A FEW OF THESE STORMS COULD PUSH OFF THE MOUNTAINS AND
APPROACH THE TRIAD AREA TOWARD DINNER TIME BUT GIVEN THE LIMITED
COVERAGE AND STABLE AIRMASS ACROSS THE TRIAD...WILL NOT INCLUDE ANY
STORMS FOR THIS AFTERNOON OR EARLY EVENING. SCT CONVECTION THAT
DEVELOPS FURTHER UPSTREAM ACROSS THE OH VALLEY AND THE MID ATLANTIC
THIS AFTERNOON MAY HAVE SUFFICIENT SUPPORT TO ALLOW A SHOWER OR
STORM MOVE INTO THE NORTHWEST PIEDMONT VERY LATE IN THE EVENING.
THIS SCENARIO IS SUPPORTED BY A FEW OF THE CONVECTION ALLOWING
MODELS INCLUDING THE NCAR ENSEMBLE. SO WILL INCLUDE A SLIGHT CHC POP
FOR THIS AREA TO COVER THE POTENTIAL. OTHERWISE...FAIR WEATHER AND
DRY CONDITIONS ARE EXPECTED TODAY AND TONIGHT. THICKNESSES VALUES
AND STATISTICAL GUIDANCE HAVE TRENDED A LITTLE COOLER FOR TODAYS
HIGHS WHICH SHOULD RANGE BETWEEN 86 AND 90. LOWS TONIGHT WILL RANGE
BETWEEN 66-72. LIGHT AND VARIABLE WINDS WILL BECOME LIGHT
SOUTHEASTERLY AND SOUTHERLY ACROSS THE WESTERN PIEDMONT TODAY AND
BECOME LIGHT NORTHEAST AND EASTERLY EAST OF THE RIDGE AXIS ACROSS
THE EASTERN PIEDMONT AND COASTAL PLAIN. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 312 AM SUNDAY...
A NORTHWEST FLOW ALOFT ACROSS CENTRAL NC EARLY MONDAY BECOMES MORE
WESTERLY AND SLIGHTLY SOUTHWESTERLY BY MONDAY NIGHT AS UPPER LEVEL
TROUGHING AND THE ASSOCIATED HEIGHT FALLS MOVE INTO THE GREAT LAKES
REGION. AT THE SURFACE...A WARM FRONT WILL LIFT NORTH ACROSS NC
EARLY MONDAY WITH AN APPROACHING COLD FRONT REACHING THE WESTERN
APPALACHIANS TOWARD DAYBREAK TUESDAY. CHANCES FOR SHOWERS AND
THUNDERSTORMS GRADUALLY INCREASE DURING THE PERIOD FROM WEST TO
EAST. WITH THE BEST FORCING REMAINING NORTH OF OUR REGION AND
INDICATIONS OF LIMITED INSTABILITY AND MEAGER MID LEVEL LAPSE
RATES...HAVE CUT BACK ON POPS A BIT. NEW SPC DAY 2 OUTLOOK KEEPS THE
MARGINAL SEVERE WEATHER THREAT WEST OF OUR AREA...MAINLY OWING TO
THE LIMITED INSTABILITY IN OUR FORECAST AREA. DESPITE A WARMING
ATMOSPHERE AND INCREASING THICKNESS VALUES...CLOUDS SHOULD HOLD
HIGHS BACK SLIGHTLY ON MONDAY...HIGH SHOULD RANGE BETWEEN 86 AND 92.
LOWS MONDAY NIGHT WILL BE MODERATED BY THE CLOUD COVER AND RANGE
BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...
TUESDAY AND WEDNESDAY: MODELS ARE COMING INTO FAIRLY GOOD AGREEMENT
AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED FOR TUESDAY.
ALOFT...EXPECT AN EASTERN CONUS TROUGH WITH A STRONG RIDGE OVER THE
MOUNTAIN WEST. WHILE THE TROUGH IS EXPECTED TO DEEPEN OVER THE
CAROLINAS ON TUESDAY...IT IS NOT EXPECTED TO TRANSLATE MUCH TO THE
EAST AND THUS CENTRAL NC WILL REMAIN NEAR THE BASE OF THIS TROUGH
WITH RELATIVELY WEAK WINDS ALOFT. AT THE SURFACE...LOW PRESSURE OVER
NEW YORK STATE WILL HELP MOVE A COLD FRONT THROUGH THE APPALACHIANS
AND INTO THE CAROLINAS ON TUESDAY AFTERNOON...EXITING TUESDAY NIGHT
INTO WEDNESDAY MORNING.
ONGOING PREFRONTAL CONVECTIVE ACTIVITY ON TUESDAY MORNING MAY PLAY A
KEY ROLE IN LIMITING DESTABILIZATION OVER THE AREA AND FORECAST
SOUNDINGS CERTAINLY INDICATE THIS WITH BOTH THE GFS AND THE NAM
SHOWING MAX INSTABILITY NEAR 1000 J/KG AS OPPOSED TO THE 1500-2000
J/KG SHOWN IN PRIOR SIMULATIONS. BULK SHEAR HAS ALSO COME DOWN BUT
STILL SHOULD REMAIN AROUND 20-25 KTS. THIS COULD SUPPORT SOME
MULTICELLULAR TO BROKEN LINE SEGMENT ACTIVITY AS THE FRONT MOVES
THROUGH LATER IN THE DAY ON TUESDAY. THEREFORE EXPECT STRONG STORMS
WITH A FEW ISOLATED SEVERE THUNDERSTORMS POSSIBLE WITH DAMAGING
WINDS THE MOST LIKELY THREAT. CURRENTLY THE SPC DAY 3 CONVECTIVE
OUTLOOK HAS THE AREA UNDER A MARGINAL RISK FOR SEVERE STORMS ON
TUESDAY. WITH PRE-FRONTAL CLOUD COVER EXPECT HIGHS IN THE UPPER 80S
TO LOW 90S WITH LOWS TUESDAY NIGHT IN THE UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH SUNDAY:
THE FRONT WILL EXIT TO THE EAST ON WEDNESDAY ALTHOUGH SOME LINGERING
SHOWERS COULD STILL THREATEN THE EXTREME SOUTHEASTERN
COUNTIES...PARTICULARLY WEDNESDAY AFTERNOON ON A SEABREEZE.
OTHERWISE HIGH PRESSURE OVER THE OHIO VALLEY WILL BUILD INTO THE
AREA FROM THE NORTHWEST...YIELDING COOL NORTHERLY FLOW AND DRY
CONDITIONS. HIGH WILL BUILD IN OVER THE CAROLINAS FOR THE END OF THE
WEEK AND INTO THE WEEKEND AS UPPER LEVEL FLOW BECOMES VERY STAGNANT.
THIS WILL LEAD TO A PROLONGED PERIOD OF QUIET WEATHER AND RELATIVELY
COOLER TEMPERATURES. HIGH TEMPERATURES GENERALLY IN THE MID TO UPPER
80S WITH LOWS IN THE LOW TO UPPER 60S.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 215 PM SUNDAY...
VFR CONDITIONS EXPECTED TO DOMINATE THROUGH TONIGHT... ALTHOUGH
THERE IS A CHANCE OF MVFR CONDITIONS TONIGHT INTO MON MORNING AT
INT/GSO AFTER 08Z. WEAK HIGH PRESSURE SITS ACROSS CENTRAL NC THIS
AFTERNOON... AND THIS WILL GIVE WAY TO A WARM FRONT MOVING FROM OUR
SW TO THE NE THROUGH NC LATE TONIGHT THROUGH MON... RESULTING IN THE
CURRENT LIGHT/VARIABLE SURFACE WINDS TO INCREASE TO 7-12 KTS MON
MORNING FROM THE S/SW. WE`LL CONTINUE TO SEE TYPICAL DAYTIME CLOUDS
WITH VFR CIGS INTO EARLY THIS EVENING... FOLLOWED BY INCREASING AND
THICKENING MID AND HIGH CLOUDS (ALSO VFR) DURING THE EVENING AND
CONTINUING OVERNIGHT AS THE REMNANT CLOUDINESS LEFTOVER FROM
UPSTREAM STORM COMPLEXES DRIFT SOUTHEASTWARD OVER OUR REGION.
ISOLATED SHOWERS ARE POSSIBLE TONIGHT NEAR INT/GSO AND PERHAPS
REACHING RDU LATE TONIGHT. DESPITE THIS... VSBYS/CIGS SHOULD STAY
PREDOMINANTLY VFR... ALTHOUGH THERE IS A SMALL CHANCE THAT CIGS
COULD DROP TO HIGH-END MVFR AFTER 08Z TONIGHT AT INT/GSO... AND
AVIATION INTERESTS SHOULD CHECK BACK FOR LATER FORECASTS. SCATTERED
STORMS ARE EXPECTED TO DEVELOP NEAR THE END OF THE TAF VALID PERIOD.
LOOKING BEYOND 18Z MON: SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE
EXPECTED MON AFTERNOON... AFFECTING INT/GSO FIRST THEN REACHING RDU
AND FINALLY RWI/FAY BY LATE AFTERNOON... AND STRONG ERRATIC GUSTY
WINDS ALONG WITH SUB-VFR CONDITIONS CAN BE EXPECTED IN AND NEAR ANY
SUCH STORMS. STORMS WILL DECREASE IN INTENSITY MON EVENING/NIGHT BUT
CHANCES REMAIN HIGH FOR SUB-VFR VSBYS/CIGS IN RAIN/ISOLD THUNDER
THROUGH MON NIGHT. ANOTHER ROUND OF AFTERNOON STORMS IS EXPECTED TUE
AS A COLD FRONT MOVES THROUGH THE AREA. MAINLY VFR CONDITIONS
EXPECTED WED-FRI AS HIGH PRESSURE BUILDS IN FROM THE NW. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...ELLIS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
153 PM EDT SUN AUG 9 2015
.SYNOPSIS...WEAK HIGH PRESSURE WILL EXTEND INTO THE REGION THROUGH
TONIGHT. A WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY. A
COLD FRONT WILL SWEEP THROUGH THE REGION TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM SUNDAY...
BAND OF LIGHT SHOWERS ORIENTED NNW TO SSE WHICH DROPPED SSE THROUGH
THE NRN PIEDMONT EARLIER THIS MORNING HAS PUSHED INTO THE SANDHILLS
WHILE DIMINISHING IN COVERAGE. THE SUBTLE FORCING DRIVING THIS
FEATURE INCLUDING WEAK LOW LEVEL MASS CONVERGENCE ALONG THE LEADING
EDGE OF AN 850 MB MOISTURE BOUNDARY APPEARS TO BE DWINDLING... AND
WITH THE DEPARTURE OF A WEAKENING MID LEVEL WAVE/MCV BY AFTERNOON...
THIS SHOULD CONTINUE TO FALL APART SLOWLY. MODELS SHOW MOUNTAIN
CONVECTION FORMING THIS AFTERNOON... AND THE MEAN FLOW PATTERN WOULD
SUPPORT SOME OF THIS ACTIVITY SLIPPING SE INTO THE FAR WRN PIEDMONT
AFTER SUNSET... SO WILL RETAIN LOW CHANCE POPS LATER TONIGHT. PATCHY
MOISTURE IS EXPECTED TO PERSIST AT 700 MB WITH WEAK FLOW... SO
EXPECT GENERALLY PARTLY CLOUDY SKIES AREAWIDE TODAY ESPECIALLY AS WE
APPROACH PEAK MIXING... WITH SHORTER PERIODS OF MOSTLY CLOUDY SKIES.
OBSERVED TRENDS AND HI-RES GUIDANCE SUPPORT HIGHS OF 85-90...
ASSUMING ENOUGH BREAKS IN THE CLOUDS FOR SUFFICIENT INSOLATION. -GIH
EARLIER DISCUSSION FROM 250 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE CENTERED OVER THE MID ATLANTIC REGION AS LOW PRESSURE
OFF THE VA COAST MOVES AWAY FROM THE REGION. SATELLITE IMAGERY SHOWS
A REGION OF SCT TO MOSTLY BKN LOW/MID CLOUDS FROM CENTRAL PA
SOUTHWARD TO WESTERN NC. THESE CLOUDS HAVE BEEN EXPANDING SOUTHWARD
AND ARE ASSOCIATED WITH A REGION OF ENHANCED MOISTURE AND WEAK
ISENTROPIC UPGLIDE ABOUT THE 305K SURFACE. REGIONAL RADAR SHOWS A
FEW SHOWERS JUST NORTH OF THE TRIAD IN FAR NORTHERN NC AND
SOUTHWESTERN VA. EARLIER RUNS OF THE HRRR INDICATED THESE SHOWERS
COULD PUSH SOUTHEAST TOWARD THE TRIANGLE AREA BUT THE LAST RUN OR
TWO HAVE BACKED OFF THIS SCENARIO. WILL INCLUDE A SLIGHT CHANCE OF A
SHOWER FOR A SMALL AREA IN THE TRIAD FOR THE NEXT FEW HOURS AS THESE
SPRINKLES/SHOWERS MOVE SOUTHEAST AND LIKELY DISSIPATE.
THE REMAINDER OF TODAY SHOULD FEATURE FAIR WEATHER WITH PARTLY
CLOUDY SKIES FEATURING MULTIPLE CLOUD LAYERS. LITTLE FORCING FOR
ASCENT AND PRECIPITATION IS AVAILABLE ACROSS CENTRAL NC. ISOLATED TO
SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE NC MOUNTAINS THIS
AFTERNOON. A FEW OF THESE STORMS COULD PUSH OFF THE MOUNTAINS AND
APPROACH THE TRIAD AREA TOWARD DINNER TIME BUT GIVEN THE LIMITED
COVERAGE AND STABLE AIRMASS ACROSS THE TRIAD...WILL NOT INCLUDE ANY
STORMS FOR THIS AFTERNOON OR EARLY EVENING. SCT CONVECTION THAT
DEVELOPS FURTHER UPSTREAM ACROSS THE OH VALLEY AND THE MID ATLANTIC
THIS AFTERNOON MAY HAVE SUFFICIENT SUPPORT TO ALLOW A SHOWER OR
STORM MOVE INTO THE NORTHWEST PIEDMONT VERY LATE IN THE EVENING.
THIS SCENARIO IS SUPPORTED BY A FEW OF THE CONVECTION ALLOWING
MODELS INCLUDING THE NCAR ENSEMBLE. SO WILL INCLUDE A SLIGHT CHC POP
FOR THIS AREA TO COVER THE POTENTIAL. OTHERWISE...FAIR WEATHER AND
DRY CONDITIONS ARE EXPECTED TODAY AND TONIGHT. THICKNESSES VALUES
AND STATISTICAL GUIDANCE HAVE TRENDED A LITTLE COOLER FOR TODAYS
HIGHS WHICH SHOULD RANGE BETWEEN 86 AND 90. LOWS TONIGHT WILL RANGE
BETWEEN 66-72. LIGHT AND VARIABLE WINDS WILL BECOME LIGHT
SOUTHEASTERLY AND SOUTHERLY ACROSS THE WESTERN PIEDMONT TODAY AND
BECOME LIGHT NORTHEAST AND EASTERLY EAST OF THE RIDGE AXIS ACROSS
THE EASTERN PIEDMONT AND COASTAL PLAIN. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 312 AM SUNDAY...
A NORTHWEST FLOW ALOFT ACROSS CENTRAL NC EARLY MONDAY BECOMES MORE
WESTERLY AND SLIGHTLY SOUTHWESTERLY BY MONDAY NIGHT AS UPPER LEVEL
TROUGHING AND THE ASSOCIATED HEIGHT FALLS MOVE INTO THE GREAT LAKES
REGION. AT THE SURFACE...A WARM FRONT WILL LIFT NORTH ACROSS NC
EARLY MONDAY WITH AN APPROACHING COLD FRONT REACHING THE WESTERN
APPALACHIANS TOWARD DAYBREAK TUESDAY. CHANCES FOR SHOWERS AND
THUNDERSTORMS GRADUALLY INCREASE DURING THE PERIOD FROM WEST TO
EAST. WITH THE BEST FORCING REMAINING NORTH OF OUR REGION AND
INDICATIONS OF LIMITED INSTABILITY AND MEAGER MID LEVEL LAPSE
RATES...HAVE CUT BACK ON POPS A BIT. NEW SPC DAY 2 OUTLOOK KEEPS THE
MARGINAL SEVERE WEATHER THREAT WEST OF OUR AREA...MAINLY OWING TO
THE LIMITED INSTABILITY IN OUR FORECAST AREA. DESPITE A WARMING
ATMOSPHERE AND INCREASING THICKNESS VALUES...CLOUDS SHOULD HOLD
HIGHS BACK SLIGHTLY ON MONDAY...HIGH SHOULD RANGE BETWEEN 86 AND 92.
LOWS MONDAY NIGHT WILL BE MODERATED BY THE CLOUD COVER AND RANGE
BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...
TUESDAY AND WEDNESDAY: MODELS ARE COMING INTO FAIRLY GOOD AGREEMENT
AS FAR AS THE SYNOPTIC PATTERN IS CONCERNED FOR TUESDAY.
ALOFT...EXPECT AN EASTERN CONUS TROUGH WITH A STRONG RIDGE OVER THE
MOUNTAIN WEST. WHILE THE TROUGH IS EXPECTED TO DEEPEN OVER THE
CAROLINAS ON TUESDAY...IT IS NOT EXPECTED TO TRANSLATE MUCH TO THE
EAST AND THUS CENTRAL NC WILL REMAIN NEAR THE BASE OF THIS TROUGH
WITH RELATIVELY WEAK WINDS ALOFT. AT THE SURFACE...LOW PRESSURE OVER
NEW YORK STATE WILL HELP MOVE A COLD FRONT THROUGH THE APPALACHIANS
AND INTO THE CAROLINAS ON TUESDAY AFTERNOON...EXITING TUESDAY NIGHT
INTO WEDNESDAY MORNING.
ONGOING PREFRONTAL CONVECTIVE ACTIVITY ON TUESDAY MORNING MAY PLAY A
KEY ROLE IN LIMITING DESTABILIZATION OVER THE AREA AND FORECAST
SOUNDINGS CERTAINLY INDICATE THIS WITH BOTH THE GFS AND THE NAM
SHOWING MAX INSTABILITY NEAR 1000 J/KG AS OPPOSED TO THE 1500-2000
J/KG SHOWN IN PRIOR SIMULATIONS. BULK SHEAR HAS ALSO COME DOWN BUT
STILL SHOULD REMAIN AROUND 20-25 KTS. THIS COULD SUPPORT SOME
MULTICELLULAR TO BROKEN LINE SEGMENT ACTIVITY AS THE FRONT MOVES
THROUGH LATER IN THE DAY ON TUESDAY. THEREFORE EXPECT STRONG STORMS
WITH A FEW ISOLATED SEVERE THUNDERSTORMS POSSIBLE WITH DAMAGING
WINDS THE MOST LIKELY THREAT. CURRENTLY THE SPC DAY 3 CONVECTIVE
OUTLOOK HAS THE AREA UNDER A MARGINAL RISK FOR SEVERE STORMS ON
TUESDAY. WITH PRE-FRONTAL CLOUD COVER EXPECT HIGHS IN THE UPPER 80S
TO LOW 90S WITH LOWS TUESDAY NIGHT IN THE UPPER 60S TO LOWER 70S.
WEDNESDAY THROUGH SUNDAY:
THE FRONT WILL EXIT TO THE EAST ON WEDNESDAY ALTHOUGH SOME LINGERING
SHOWERS COULD STILL THREATEN THE EXTREME SOUTHEASTERN
COUNTIES...PARTICULARLY WEDNESDAY AFTERNOON ON A SEABREEZE.
OTHERWISE HIGH PRESSURE OVER THE OHIO VALLEY WILL BUILD INTO THE
AREA FROM THE NORTHWEST...YIELDING COOL NORTHERLY FLOW AND DRY
CONDITIONS. HIGH WILL BUILD IN OVER THE CAROLINAS FOR THE END OF THE
WEEK AND INTO THE WEEKEND AS UPPER LEVEL FLOW BECOMES VERY STAGNANT.
THIS WILL LEAD TO A PROLONGED PERIOD OF QUIET WEATHER AND RELATIVELY
COOLER TEMPERATURES. HIGH TEMPERATURES GENERALLY IN THE MID TO UPPER
80S WITH LOWS IN THE LOW TO UPPER 60S.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 705 AM SUNDAY...
VFR CONDITIONS ARE EXPECTED TO DOMINATE ACROSS CENTRAL NC DURING THE
NEXT 24 HOURS. AN UPPER LEVEL DISTURBANCE WAS PRODUCING AN AREA OF
SCT-BKN CLOUDS WITH VFR BASES OF 6-8KFT ACROSS THE PIEDMONT
AREA THIS MORNING. THESE CLOUDS WILL CONTINUE TO IMPACT THE
TERMINALS AT KINT/KGSO/KRDU THROUGH MID MORNING. RADAR AND SURFACE
OBSERVATIONS WERE INDICATING A FEW SHOWERS BETWEEN THE TRIAD AND
TRIANGLE IMPACTING KBUY AND KSCR THAT WERE SHIFTING EAST. A LOWERING
OF THE CLOUD DECK AND A BRIEF MVFR VSBY RESTRICTION IN A LIGHT RAIN
SHOWER CAN BE EXPECTED. WILL OMIT ANY MENTION IN THE TAFS AS THIS
FEATURE SHOULD DIMINISH BY THE TIME IT WOULD APPROACH KRDU. A FEW
THUNDERSTORMS MAY DEVELOP ACROSS THE
BLUE RIDGE THIS AFTERNOON AND DRIFT INTO THE WESTERN PIEDMONT DURING
THE EARLY EVENING. COVERAGE OF THESE STORMS SHOULD BE LIMITED AND
CONFIDENCE THAT THEY WILL MAKE IT TO THE KINT/KGSO TERMINALS IS VERY
SMALL SO WILL NOT INCLUDE IT IN THE TERMINALS.
OTHERWISE...LOOK FOR MAINLY SCT TO OCCASIONALLY BKN CLOUDS AT 5-8KFT
TODAY WITH PERIODS OF BKN MID AND HIGH CLOUDS. LIGHT AND VARIABLE
WINDS THIS MORNING WILL BECOME LIGHT SOUTHWEST IN THE WESTERN
PIEDMONT (KINT/KGSO)AND LIGHT NORTHEASTERLY IN THE EASTERN PIEDMONT
AND COASTAL PLAIN TERMINALS (KRDU/KRWI/KFAY).
LOOKING FURTHER AHEAD... A TREND FOR MORE ACTIVE WEATHER AND
POTENTIAL ADVERSE AVIATION CONDITIONS WITH SCT CONVECTION RETURNS ON
MONDAY AND INCREASES FOR MONDAY NIGHT AND TUESDAY/TUESDAY NIGHT AS A
COLD FRONT MOVES THROUGH THE AREA. FAIR WEATHER SHOULD RETURN ON
WEDNESDAY AND PERSIST INTO THURSDAY. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...ELLIS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
945 AM EDT SUN AUG 9 2015
.SYNOPSIS...WEAK HIGH PRESSURE WILL EXTEND INTO THE REGION THROUGH
TONIGHT. A WARM FRONT WILL LIFT NORTH ACROSS THE AREA ON MONDAY. A
COLD FRONT WILL SWEEP THROUGH THE REGION TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM SUNDAY...
BAND OF LIGHT SHOWERS ORIENTED NNW TO SSE WHICH DROPPED SSE THROUGH
THE NRN PIEDMONT EARLIER THIS MORNING HAS PUSHED INTO THE SANDHILLS
WHILE DIMINISHING IN COVERAGE. THE SUBTLE FORCING DRIVING THIS
FEATURE INCLUDING WEAK LOW LEVEL MASS CONVERGENCE ALONG THE LEADING
EDGE OF AN 850 MB MOISTURE BOUNDARY APPEARS TO BE DWINDLING... AND
WITH THE DEPARTURE OF A WEAKENING MID LEVEL WAVE/MCV BY AFTERNOON...
THIS SHOULD CONTINUE TO FALL APART SLOWLY. MODELS SHOW MOUNTAIN
CONVECTION FORMING THIS AFTERNOON... AND THE MEAN FLOW PATTERN WOULD
SUPPORT SOME OF THIS ACTIVITY SLIPPING SE INTO THE FAR WRN PIEDMONT
AFTER SUNSET... SO WILL RETAIN LOW CHANCE POPS LATER TONIGHT. PATCHY
MOISTURE IS EXPECTED TO PERSIST AT 700 MB WITH WEAK FLOW... SO
EXPECT GENERALLY PARTLY CLOUDY SKIES AREAWIDE TODAY ESPECIALLY AS WE
APPROACH PEAK MIXING... WITH SHORTER PERIODS OF MOSTLY CLOUDY SKIES.
OBSERVED TRENDS AND HI-RES GUIDANCE SUPPORT HIGHS OF 85-90...
ASSUMING ENOUGH BREAKS IN THE CLOUDS FOR SUFFICIENT INSOLATION. -GIH
EARLIER DISCUSSION FROM 250 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE CENTERED OVER THE MID ATLANTIC REGION AS LOW PRESSURE
OFF THE VA COAST MOVES AWAY FROM THE REGION. SATELLITE IMAGERY SHOWS
A REGION OF SCT TO MOSTLY BKN LOW/MID CLOUDS FROM CENTRAL PA
SOUTHWARD TO WESTERN NC. THESE CLOUDS HAVE BEEN EXPANDING SOUTHWARD
AND ARE ASSOCIATED WITH A REGION OF ENHANCED MOISTURE AND WEAK
ISENTROPIC UPGLIDE ABOUT THE 305K SURFACE. REGIONAL RADAR SHOWS A
FEW SHOWERS JUST NORTH OF THE TRIAD IN FAR NORTHERN NC AND
SOUTHWESTERN VA. EARLIER RUNS OF THE HRRR INDICATED THESE SHOWERS
COULD PUSH SOUTHEAST TOWARD THE TRIANGLE AREA BUT THE LAST RUN OR
TWO HAVE BACKED OFF THIS SCENARIO. WILL INCLUDE A SLIGHT CHANCE OF A
SHOWER FOR A SMALL AREA IN THE TRIAD FOR THE NEXT FEW HOURS AS THESE
SPRINKLES/SHOWERS MOVE SOUTHEAST AND LIKELY DISSIPATE.
THE REMAINDER OF TODAY SHOULD FEATURE FAIR WEATHER WITH PARTLY
CLOUDY SKIES FEATURING MULTIPLE CLOUD LAYERS. LITTLE FORCING FOR
ASCENT AND PRECIPITATION IS AVAILABLE ACROSS CENTRAL NC. ISOLATED TO
SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS THE NC MOUNTAINS THIS
AFTERNOON. A FEW OF THESE STORMS COULD PUSH OFF THE MOUNTAINS AND
APPROACH THE TRIAD AREA TOWARD DINNER TIME BUT GIVEN THE LIMITED
COVERAGE AND STABLE AIRMASS ACROSS THE TRIAD...WILL NOT INCLUDE ANY
STORMS FOR THIS AFTERNOON OR EARLY EVENING. SCT CONVECTION THAT
DEVELOPS FURTHER UPSTREAM ACROSS THE OH VALLEY AND THE MID ATLANTIC
THIS AFTERNOON MAY HAVE SUFFICIENT SUPPORT TO ALLOW A SHOWER OR
STORM MOVE INTO THE NORTHWEST PIEDMONT VERY LATE IN THE EVENING.
THIS SCENARIO IS SUPPORTED BY A FEW OF THE CONVECTION ALLOWING
MODELS INCLUDING THE NCAR ENSEMBLE. SO WILL INCLUDE A SLIGHT CHC POP
FOR THIS AREA TO COVER THE POTENTIAL. OTHERWISE...FAIR WEATHER AND
DRY CONDITIONS ARE EXPECTED TODAY AND TONIGHT. THICKNESSES VALUES
AND STATISTICAL GUIDANCE HAVE TRENDED A LITTLE COOLER FOR TODAYS
HIGHS WHICH SHOULD RANGE BETWEEN 86 AND 90. LOWS TONIGHT WILL RANGE
BETWEEN 66-72. LIGHT AND VARIABLE WINDS WILL BECOME LIGHT
SOUTHEASTERLY AND SOUTHERLY ACROSS THE WESTERN PIEDMONT TODAY AND
BECOME LIGHT NORTHEAST AND EASTERLY EAST OF THE RIDGE AXIS ACROSS
THE EASTERN PIEDMONT AND COASTAL PLAIN. -BLAES
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 312 AM SUNDAY...
A NORTHWEST FLOW ALOFT ACROSS CENTRAL NC EARLY MONDAY BECOMES MORE
WESTERLY AND SLIGHTLY SOUTHWESTERLY BY MONDAY NIGHT AS UPPER LEVEL
TROUGHING AND THE ASSOCIATED HEIGHT FALLS MOVE INTO THE GREAT LAKES
REGION. AT THE SURFACE...A WARM FRONT WILL LIFT NORTH ACROSS NC
EARLY MONDAY WITH AN APPROACHING COLD FRONT REACHING THE WESTERN
APPALACHIANS TOWARD DAYBREAK TUESDAY. CHANCES FOR SHOWERS AND
THUNDERSTORMS GRADUALLY INCREASE DURING THE PERIOD FROM WEST TO
EAST. WITH THE BEST FORCING REMAINING NORTH OF OUR REGION AND
INDICATIONS OF LIMITED INSTABILITY AND MEAGER MID LEVEL LAPSE
RATES...HAVE CUT BACK ON POPS A BIT. NEW SPC DAY 2 OUTLOOK KEEPS THE
MARGINAL SEVERE WEATHER THREAT WEST OF OUR AREA...MAINLY OWING TO
THE LIMITED INSTABILITY IN OUR FORECAST AREA. DESPITE A WARMING
ATMOSPHERE AND INCREASING THICKNESS VALUES...CLOUDS SHOULD HOLD
HIGHS BACK SLIGHTLY ON MONDAY...HIGH SHOULD RANGE BETWEEN 86 AND 92.
LOWS MONDAY NIGHT WILL BE MODERATED BY THE CLOUD COVER AND RANGE
BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 310 AM SUNDAY...
FOR THE PERIOD TUESDAY THROUGH WEDNESDAY...DIFFERENCES BETWEEN THE
GFS AND THE NAM FOR TUESDAY INTO TUESDAY NIGHT MAKE THIS FORECAST OF
SOMEWHAT LOWER CONFIDENCE...AS THE GFS BY EARLY TUESDAY FORECASTS A
DRY SLOT MOVING INTO CENTRAL NORTH CAROLINA REALLY REDUCING
PRECIPITATION CHANCES FOR THE MORNING INTO THE EARLY AFTERNOON...
WHILE THE NAM IS MUCH MORE MOIST TO START THE DAY...AND THROUGHOUT
THE DAY TOWARD INTERSTATE 95. THE GFS MAY BE ON TO SOMETHING TO
START THE DAY...BUT FOR THE AFTERNOON THINK SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS SHOULD BEGIN TO OCCUR. CONSENSUS OF THE
NAM AND GFS MODELS IS THAT AT LEAST MODEST LIFT SHOULD BE IN PLACE
AS THE SURFACE FRONT APPROACHES...WITH GOOD UPPER DIVERGENCE BY THE
AFTERNOON. K INDICES AND 850MB THETA-E VALUES ARE HIGH...AND MLCAPE
THROUGH THE LOWEST KM OR SO IS ON THE ORDER OF 1000J/KG ON THE
GFS...TO ABOUT 1500J/KG ON THE NAM. THE NAM TENDS TO BE SLOWER AND
FARTHER WEST WHILE THE GFS CERTAINLY CONCENTRATES ITS HIGHER VALUES
OF INSTABILITY AND LIFT ALONG AND EAST OF U.S. 1. WILL TEND TO LOWER
CHANCES FOR SHOWERS FOR TUESDAY MORNING...RETAINING THE LIKELY
CHANCES FOR SHOWERS AND THUNDERSTORMS FOR THE MID-AFTERNOON ON ALONG
AND EAST OF U.S. 1 AND CONTINUING INTO THE EVENING FOR MUCH OF THAT
AREA. IF THE GFS BUFR SOUNDINGS ARE CORRECT...PRECIPITATION COULD
END EARLIER...BUT THE PREVIOUS FORECAST CAPTURED A GOOD BLEND OF THE
NAM AND GFS WITH A SLIGHT CHANCE OF SHOWERS LINGERING IN THE FAR
EAST INTO EARLY WEDNESDAY MORNING.
BOTH THE NAM AND GFS FORECAST MODEST 0-3KM SHEAR AT BEST...AND WIND
FIELDS ARE NOT THAT STRONG DESPITE THE FRONT WITH THE 250MB RIGHT
ENTRANCE REGION OF THE JET NORTH IN VIRGINIA. 850MB WINDS TO AROUND
20KT OR SO...AND THE MID- AND UPPER-LEVEL JETS BEING NORTH...SUGGEST
LIMITED FORCING ALOFT. HOWEVER...IF THE GFS BUFR SOUNDINGS ARE
CORRECT...THERE IS AN INVERTED-V PROFILE THAT COULD RESULT IN
INSTANCES OF STRONG WIND GUSTS. THINK THAT THERE IS THE POTENTIAL
FOR ISOLATED SEVERE STORMS TUESDAY AFTERNOON INTO THE EVENING...
MAINLY ALONG AND EAST OF U.S. 1 WHERE THE MORE FAVORABLE PARAMETERS
SHOULD EXIST PARTICULARLY IF ONE LEANS TOWARD THE GFS. PLAN TO LEAN
MORE TOWARD THE GFS MOS GUIDANCE TEMPERATURES FOR TUESDAY...AROUND
90 FOR MUCH OF CENTRAL NORTH CAROLINA WITH HEAT INDICES JUST ABOVE
100 SOUTHEAST.
WEDNESDAY...GFS BUFR SOUNDINGS DRY AND AFTER ANY EARLY MORNING
ISOLATED SHOWER TOWARD KGSB AND KCTZ BUFR SOUNDINGS WOULD SUGGEST
LOW CHANCES FOR ANY DEEP CONVECTION...WITH POSSIBLY SOME HIGH-BASED
CU. DEW POINTS SHOULD BE NOTICEABLY LOWER OR BECOME NOTICEABLY LOWER
ACROSS THE AREA. ACCOMPANIED BY A NORTH TO NORTHEAST LOW-LEVEL
FLOW...HIGH TEMPERATURES MAINLY 85 TO 90.
FOR THE PERIOD WEDNESDAY NIGHT THROUGH SATURDAY...THE UPPER-AIR
PATTERN FEATURES A PERSISTENT RIDGE AXIS FROM THE SOUTHERN PLAINS
AND FOUR CORNERS NORTH ALONG THE ROCKIES AND INTO THE PLAINS OF
CANADA...WHILE BROAD TROUGHINESS EXISTS OVER THE EASTERN THIRD OF
THE CONUS. THE COLD FRONT SHOULD BE SOUTH OF CENTRAL NORTH CAROLINA
WEDNESDAY INTO WEDNESDAY NIGHT...CONTINUING TO GRADUALLY MOVE SOUTH
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. WEAK PIEDMONT SURFACE
TROUGHING RETURNS BY SATURDAY. THE ECMWF AND THE GFS TO SOME DEGREE
FEATURE A WEAK SURFACE WAVE DEVELOPING ALONG THE FRONT WHICH MAY
SLOW ITS PROGRESS OR RESULT IN SOME LINGERING MOISTURE NEAR THE
COASTAL PLAIN OVERNIGHT WEDNESDAY...BUT FOR THIS FORECAST WILL
MAINTAIN CONSISTENCY AND LEAVE THE FORECAST DRY OVERNIGHT ALONG AND
EAST OF INTERSTATE 95 AS THE MEAN DRY AIR ON THE GFS IS QUITE
NOTICEABLE. ON THURSDAY AFTERNOON...WITH THE SURFACE FRONT JUST TO
THE SOUTH...A VERY ISOLATED SHOWER COULD OCCUR MAINLY SOUTH OF A
LINE FROM KMEB TO KCTZ...BUT AGAIN AT THIS STAGE LEAVING THE
FORECAST DRY AND MAINTAINING CONSISTENCY SEEMS A WISE APPROACH. AT
THE END OF THE WEEK...THE GFS IN PARTICULAR...WITH WEAKNESS IN
HEIGHTS ALOFT...FORECASTS SOME DEEP CONVECTION IN VICINITY OF THE
MOUNTAINS...AND SOME QPF TRIES TO GRAZE THE FAR WESTERN PIEDMONT
ESPECIALLY LATE FRIDAY. HOWEVER...THE STEERING FLOW SEEMS QUITE WEAK
AND THICKNESS PROFILES WOULD SUGGEST FOR NOW THE EASTWARD PROGRESS
OF SUCH CONVECTION SHOULD REMAIN WEST OF CENTRAL NORTH CAROLINA.
OVERALL...WITH ALL OF THIS SAID...THIS FORECAST WILL CONTINUE TO BE
DRY FOR CENTRAL NORTH CAROLINA WEDNESDAY NIGHT THROUGH SATURDAY.
TEMPERATURES SHOULD AVERAGE ABOUT A CATEGORY BELOW NORMAL BEHIND THE
COLD FRONT BY THURSDAY...GRADUALLY RECOVERING TO AT OR ABOVE NORMAL
BY SATURDAY USING A COMBINATION OF 1000-850MB THICKNESSES WHICH ARE
QUITE WARM...AND MOS GUIDANCE CONSENSUS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 705 AM SUNDAY...
VFR CONDITIONS ARE EXPECTED TO DOMINATE ACROSS CENTRAL NC DURING THE
NEXT 24 HOURS. AN UPPER LEVEL DISTURBANCE WAS PRODUCING AN AREA OF
SCT-BKN CLOUDS WITH VFR BASES OF 6-8KFT ACROSS THE PIEDMONT
AREA THIS MORNING. THESE CLOUDS WILL CONTINUE TO IMPACT THE
TERMINALS AT KINT/KGSO/KRDU THROUGH MID MORNING. RADAR AND SURFACE
OBSERVATIONS WERE INDICATING A FEW SHOWERS BETWEEN THE TRIAD AND
TRIANGLE IMPACTING KBUY AND KSCR THAT WERE SHIFTING EAST. A LOWERING
OF THE CLOUD DECK AND A BRIEF MVFR VSBY RESTRICTION IN A LIGHT RAIN
SHOWER CAN BE EXPECTED. WILL OMIT ANY MENTION IN THE TAFS AS THIS
FEATURE SHOULD DIMINISH BY THE TIME IT WOULD APPROACH KRDU. A FEW
THUNDERSTORMS MAY DEVELOP ACROSS THE
BLUE RIDGE THIS AFTERNOON AND DRIFT INTO THE WESTERN PIEDMONT DURING
THE EARLY EVENING. COVERAGE OF THESE STORMS SHOULD BE LIMITED AND
CONFIDENCE THAT THEY WILL MAKE IT TO THE KINT/KGSO TERMINALS IS VERY
SMALL SO WILL NOT INCLUDE IT IN THE TERMINALS.
OTHERWISE...LOOK FOR MAINLY SCT TO OCCASIONALLY BKN CLOUDS AT 5-8KFT
TODAY WITH PERIODS OF BKN MID AND HIGH CLOUDS. LIGHT AND VARIABLE
WINDS THIS MORNING WILL BECOME LIGHT SOUTHWEST IN THE WESTERN
PIEDMONT (KINT/KGSO)AND LIGHT NORTHEASTERLY IN THE EASTERN PIEDMONT
AND COASTAL PLAIN TERMINALS (KRDU/KRWI/KFAY).
LOOKING FURTHER AHEAD... A TREND FOR MORE ACTIVE WEATHER AND
POTENTIAL ADVERSE AVIATION CONDITIONS WITH SCT CONVECTION RETURNS ON
MONDAY AND INCREASES FOR MONDAY NIGHT AND TUESDAY/TUESDAY NIGHT AS A
COLD FRONT MOVES THROUGH THE AREA. FAIR WEATHER SHOULD RETURN ON
WEDNESDAY AND PERSIST INTO THURSDAY. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...DJF
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1156 AM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1126 AM CDT SUN AUG 9 2015
WATER VAPOR IMAGERY LOOP CONTINUES TO SHOW A MID/UPPER LEVEL LOW
CIRCULATING OVER SOUTHEAST MONTANA...WITH A LEAD SHORTWAVE SEEN
SCOOTING ALONG THE ND/SD BORDER...LOCATED CLOSE TO LEMMON SD.
LOCAL/REGIONAL RADAR DETAILS AN AREA AND A LINE OF SHOWERS/THUNDERSTORMS
ASSOCIATED WITH THIS SHORTWAVE...MOVING EAST BUT ALSO SLOWLY
DEVELOPING NORTH. SPC MESOANALYSIS OVER SOUTHERN NORTH DAKOTA
CERTAINLY INDICATING DESTABILIZING CONDITIONS WITH INCREASING SFC
BASED CAPE TO 1000 J/KG...AND LOW LEVEL LAPSE RATES TO 7-7.5 C/KM.
0-6KM SHEAR NUDGING NORTH ACROSS THE BORDER TO 25KT. MID LEVEL
LAPSE RATES REMAIN WEAK AT THIS TIME. AS THE UPPER LOW EDGES CLOSER
INTO NORTHWEST SOUTH DAKOTA THIS AFTERNOON SCATTERED SHOWERS/THUNDERSTORMS
WILL CONTINUE TO DEVELOP ACROSS SOUTHERN NORTH DAKOTA. NOT EXPECTING
SEVERE WEATHER AT THIS TIME...AS THE HIGHEST INSTABILITY PARAMETERS
WILL REMAIN IN SOUTH DAKOTA. FOR THIS UPDATE...MAIN MINOR CHANGES
TO HOURLY TEMPERATURES AND POPS BASED ON LATEST SATELLITE/SURFACE
OBSERVATIONS...ALONG WITH THE HRRR AND RADAR TRENDS.
UPDATE ISSUED AT 900 AM CDT SUN AUG 9 2015
LATEST WATER VAPOR WITH RAP13 UPPER HEIGHTS OVERLAID ACCURATELY
PORTRAY A MID/UPPER LOW CIRCULATION OVER SOUTHEAST MONTANA WITH A
COUPLE OF SHORTWAVES ROTATING AROUND THE LOW INTO SOUTHWEST NORTH
DAKOTA. BOWMAN RADAR CONTINUES TO SHOW INCREASING RAIN SHOWER
COVERAGE SOUTHWEST...WITH BISMARCK RADAR INDICATING ISOLATED TO
SCATTERED SHOWERS IN SOUTH CENTRAL NORTH DAKOTA AND INTO THE
SOUTHERN JAMES RIVER VALLEY. FOR THIS UPDATE...BLENDED IN CURRENT
FORECAST WITH THE LATEST HRRR AND ADJUSTED THOSE POPS BASED ON
CURRENT RADAR TRENDS AND SURFACE OBSERVATIONS.
OVERALL...MODEL CONSENSUS AND FORECAST OVERALL REMAINS NEARLY
UNCHANGED WITH ISOLATED TO SCATTERED SHOWERS MAINLY ALONG AND
SOUTH OF I-94 REST OF THIS MORNING. FOR THE AFTERNOON...SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING A BIT FARTHER NORTH AS THE
MID/UPPER LOW SLIDES INTO NORTHWEST SOUTH DAKOTA.
UPDATE ISSUED AT 643 AM CDT SUN AUG 9 2015
LOWERED SHORT TERM POPS SLIGHTLY ACROSS THE SOUTHWEST BASED ON
LATEST RADAR IMAGERY. CURRENTLY SEEING A SLIGHT LULL IN SHOWERS
ACROSS SOUTHWEST. HOWEVER...WV IMAGERY SHOWS WEAK DISTURBANCE IN
CYCLONIC FLOW OVER SOUTHEASTERN MONTANA THAT IS APPROACHING OUR
CWA. IR IMAGERY SHOWS COOLER CLOUD TOPS APPROACHING OUR SOUTHWEST AND
LAST FEW SCANS FROM BOWMAN RADAR SHOW ECHOES DEVELOPING AGAIN OVER
THE SAME AREA. OTHERWISE...BLENDED OTHER FORECAST ELEMENTS TO
LATEST OBS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT SUN AUG 9 2015
THE MAIN FOCUS TODAY IS ON SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF U.S. HIGHWAY 2.
SO FAR THIS MORNING...THE 00 UTC NAM ARW/NAM NMM AND THE LAST FEW
RUNS OF THE HRRR HAVE A GOOD HANDLE ON SHOWERS INITIATING IN
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AS ONGOING CONVECTION
SHIFTS INTO NORTHEASTERN SOUTH DAKOTA.
THUS FAR...THUNDERSTORMS HAVE BEEN CONFINED TO SOUTH DAKOTA...BUT
THAT SHOULD CHANGE AROUND NOON AS SOLAR HEATING HELPS
DESTABILIZATION BENEATH THE MID LEVEL LOW OVER EASTERN MONTANA IN
08 UTC WATER VAPOR IMAGERY. BASED ON HIRES MODELS...AND VALIDATED
BY THE STORM PREDICTION CENTER CONVECTIVE OUTLOOKS...THE SEVERE
THREAT IS LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 334 AM CDT SUN AUG 9 2015
MODELS ARE IN GOOD AGREEMENT BUILDING STRONG UPPER LEVEL RIDGE
ACROSS THE WEST EARLY IN THE WEEK WITH THE RIDGE AXIS SLOWLY
MOVING EAST. DRY WEATHER EXPECTED THROUGH MOST OF THE WEEK WITH
TEMPERATURES BUILDING TO MUCH ABOVE NORMAL BY MID-WEEK...UPPER
90S POSSIBLE WEST BY WEDNESDAY. SOME MODEL DIFFERENCES DEVELOP BY
LATE WEEK AS STRONG UPPER LEVEL LOW MOVES INTO THE PAC NW WITH THE
UPPER LEVEL RIDGE AXIS SHIFTING EAST OF THE NORTHERN PLAINS BY
EARLY WEEKEND. MAX TEMPS MODERATE BY LATE WEEK...STILL ABOVE
NORMAL IN THE UPPER 80S...WITH INCREASING CHANCES OF
SHOWERS/THUNDERSTORMS INTO THE WEEKEND AS UPPER LEVEL RIDGE BREAKS
DOWN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1126 AM CDT SUN AUG 9 2015
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED FROM
KDIK/KBIS/KJMS THROUGH 00Z MONDAY. DESPITE THE PRECIPITATION...VFR
CIGS/VSBYS REMAIN ON TRACK THROUGH THE TAF PERIOD. A MAINLY CLEAR
SKY WILL ENSUE SUNDAY NIGHT THROUGH MONDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...SCHECK
LONG TERM...JNS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
903 AM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 900 AM CDT SUN AUG 9 2015
LATEST WATER VAPOR WITH RAP13 UPPER HEIGHTS OVERLAID ACCURATELY
PORTRAY A MID/UPPER LOW CIRCULATION OVER SOUTHEAST MONTANA WITH A
COUPLE OF SHORTWAVES ROTATING AROUND THE LOW INTO SOUTHWEST NORTH
DAKOTA. BOWMAN RADAR CONTINUES TO SHOW INCREASING RAIN SHOWER
COVERAGE SOUTHWEST...WITH BISMARCK RADAR INDICATING ISOLATED TO
SCATTERED SHOWERS IN SOUTH CENTRAL NORTH DAKOTA AND INTO THE
SOUTHERN JAMES RIVER VALLEY. FOR THIS UPDATE...BLENDED IN CURRENT
FORECAST WITH THE LATEST HRRR AND ADJUSTED THOSE POPS BASED ON
CURRENT RADAR TRENDS AND SURFACE OBSERVATIONS.
OVERALL...MODEL CONSENSUS AND FORECAST OVERALL REMAINS NEARLY
UNCHANGED WITH ISOLATED TO SCATTERED SHOWERS MAINLY ALONG AND
SOUTH OF I-94 REST OF THIS MORNING. FOR THE AFTERNOON...SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING A BIT FARTHER NORTH AS THE
MID/UPPER LOW SLIDES INTO NORTHWEST SOUTH DAKOTA.
UPDATE ISSUED AT 643 AM CDT SUN AUG 9 2015
LOWERED SHORT TERM POPS SLIGHTLY ACROSS THE SOUTHWEST BASED ON
LATEST RADAR IMAGERY. CURRENTLY SEEING A SLIGHT LULL IN SHOWERS
ACROSS SOUTHWEST. HOWEVER...WV IMAGERY SHOWS WEAK DISTURBANCE IN
CYCLONIC FLOW OVER SOUTHEASTERN MONTANA THAT IS APPROACHING OUR
CWA. IR IMAGERY SHOWS COOLER CLOUD TOPS APPROACHING OUR SOUTHWEST AND
LAST FEW SCANS FROM BOWMAN RADAR SHOW ECHOES DEVELOPING AGAIN OVER
THE SAME AREA. OTHERWISE...BLENDED OTHER FORECAST ELEMENTS TO
LATEST OBS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT SUN AUG 9 2015
THE MAIN FOCUS TODAY IS ON SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF U.S. HIGHWAY 2.
SO FAR THIS MORNING...THE 00 UTC NAM ARW/NAM NMM AND THE LAST FEW
RUNS OF THE HRRR HAVE A GOOD HANDLE ON SHOWERS INITIATING IN
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AS ONGOING CONVECTION
SHIFTS INTO NORTHEASTERN SOUTH DAKOTA.
THUS FAR...THUNDERSTORMS HAVE BEEN CONFINED TO SOUTH DAKOTA...BUT
THAT SHOULD CHANGE AROUND NOON AS SOLAR HEATING HELPS
DESTABILIZATION BENEATH THE MID LEVEL LOW OVER EASTERN MONTANA IN
08 UTC WATER VAPOR IMAGERY. BASED ON HIRES MODELS...AND VALIDATED
BY THE STORM PREDICTION CENTER CONVECTIVE OUTLOOKS...THE SEVERE
THREAT IS LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 334 AM CDT SUN AUG 9 2015
MODELS ARE IN GOOD AGREEMENT BUILDING STRONG UPPER LEVEL RIDGE
ACROSS THE WEST EARLY IN THE WEEK WITH THE RIDGE AXIS SLOWLY
MOVING EAST. DRY WEATHER EXPECTED THROUGH MOST OF THE WEEK WITH
TEMPERATURES BUILDING TO MUCH ABOVE NORMAL BY MID-WEEK...UPPER
90S POSSIBLE WEST BY WEDNESDAY. SOME MODEL DIFFERENCES DEVELOP BY
LATE WEEK AS STRONG UPPER LEVEL LOW MOVES INTO THE PAC NW WITH THE
UPPER LEVEL RIDGE AXIS SHIFTING EAST OF THE NORTHERN PLAINS BY
EARLY WEEKEND. MAX TEMPS MODERATE BY LATE WEEK...STILL ABOVE
NORMAL IN THE UPPER 80S...WITH INCREASING CHANCES OF
SHOWERS/THUNDERSTORMS INTO THE WEEKEND AS UPPER LEVEL RIDGE BREAKS
DOWN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 643 AM CDT SUN AUG 9 2015
THE MAIN HAZARD TO AVIATION WILL BE POSSIBLE MVFR CONDITIONS IN
SHOWERS AND THUNDERSTORMS AT KDIK/KBIS/KJMS TODAY. TIMING INDICATED
IN TAFS IS LOW TO AVERAGE CONFIDENCE. OTHERWISE CONDITIONS WILL
REMAIN VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...SCHECK
LONG TERM...JNS
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
643 AM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 643 AM CDT SUN AUG 9 2015
LOWERED SHORT TERM POPS SLIGHTLY ACROSS THE SOUTHWEST BASED ON
LATEST RADAR IMAGERY. CURRENTLY SEEING A SLIGHT LULL IN SHOWERS
ACROSS SOUTHWEST. HOWEVER...WV IMAGERY SHOWS WEAK DISTURBANCE IN
CYCLONIC FLOW OVER SOUTHEASTERN MONTANA THAT IS APPROACHING OUR
CWA. IR IMAGERY SHOWS COOLER CLOUD TOPS APPROACHING OUR SOUTHWEST AND
LAST FEW SCANS FROM BOWMAN RADAR SHOW ECHOES DEVELOPING AGAIN OVER
THE SAME AREA. OTHERWISE...BLENDED OTHER FORECAST ELEMENTS TO
LATEST OBS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT SUN AUG 9 2015
THE MAIN FOCUS TODAY IS ON SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF U.S. HIGHWAY 2.
SO FAR THIS MORNING...THE 00 UTC NAM ARW/NAM NMM AND THE LAST FEW
RUNS OF THE HRRR HAVE A GOOD HANDLE ON SHOWERS INITIATING IN
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AS ONGOING CONVECTION
SHIFTS INTO NORTHEASTERN SOUTH DAKOTA.
THUS FAR...THUNDERSTORMS HAVE BEEN CONFINED TO SOUTH DAKOTA...BUT
THAT SHOULD CHANGE AROUND NOON AS SOLAR HEATING HELPS
DESTABILIZATION BENEATH THE MID LEVEL LOW OVER EASTERN MONTANA IN
08 UTC WATER VAPOR IMAGERY. BASED ON HIRES MODELS...AND VALIDATED
BY THE STORM PREDICTION CENTER CONVECTIVE OUTLOOKS...THE SEVERE
THREAT IS LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 334 AM CDT SUN AUG 9 2015
MODELS ARE IN GOOD AGREEMENT BUILDING STRONG UPPER LEVEL RIDGE
ACROSS THE WEST EARLY IN THE WEEK WITH THE RIDGE AXIS SLOWLY
MOVING EAST. DRY WEATHER EXPECTED THROUGH MOST OF THE WEEK WITH
TEMPERATURES BUILDING TO MUCH ABOVE NORMAL BY MID-WEEK...UPPER
90S POSSIBLE WEST BY WEDNESDAY. SOME MODEL DIFFERENCES DEVELOP BY
LATE WEEK AS STRONG UPPER LEVEL LOW MOVES INTO THE PAC NW WITH THE
UPPER LEVEL RIDGE AXIS SHIFTING EAST OF THE NORTHERN PLAINS BY
EARLY WEEKEND. MAX TEMPS MODERATE BY LATE WEEK...STILL ABOVE
NORMAL IN THE UPPER 80S...WITH INCREASING CHANCES OF
SHOWERS/THUNDERSTORMS INTO THE WEEKEND AS UPPER LEVEL RIDGE BREAKS
DOWN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 643 AM CDT SUN AUG 9 2015
THE MAIN HAZARD TO AVIATION WILL BE POSSIBLE MVFR CONDITIONS IN
SHOWERS AND THUNDERSTORMS AT KDIK/KBIS/KJMS TODAY. TIMING INDICATED
IN TAFS IS LOW TO AVERAGE CONFIDENCE. OTHERWISE CONDITIONS WILL
REMAIN VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JNS
SHORT TERM...SCHECK
LONG TERM...JNS
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
354 AM CDT SUN AUG 9 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CDT SUN AUG 9 2015
THE MAIN FOCUS TODAY IS ON SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF U.S. HIGHWAY 2.
SO FAR THIS MORNING...THE 00 UTC NAM ARW/NAM NMM AND THE LAST FEW
RUNS OF THE HRRR HAVE A GOOD HANDLE ON SHOWERS INITIATING IN
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AS ONGOING CONVECTION
SHIFTS INTO NORTHEASTERN SOUTH DAKOTA.
THUS FAR...THUNDERSTORMS HAVE BEEN CONFINED TO SOUTH DAKOTA...BUT
THAT SHOULD CHANGE AROUND NOON AS SOLAR HEATING HELPS
DESTABILIZATION BENEATH THE MID LEVEL LOW OVER EASTERN MONTANA IN
08 UTC WATER VAPOR IMAGERY. BASED ON HIRES MODELS...AND VALIDATED
BY THE STORM PREDICTION CENTER CONVECTIVE OUTLOOKS...THE SEVERE
THREAT IS LOW.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 334 AM CDT SUN AUG 9 2015
MODELS ARE IN GOOD AGREEMENT BUILDING STRONG UPPER LEVEL RIDGE
ACROSS THE WEST EARLY IN THE WEEK WITH THE RIDGE AXIS SLOWLY
MOVING EAST. DRY WEATHER EXPECTED THROUGH MOST OF THE WEEK WITH
TEMPERATURES BUILDING TO MUCH ABOVE NORMAL BY MID-WEEK...UPPER
90S POSSIBLE WEST BY WEDNESDAY. SOME MODEL DIFFERENCES DEVELOP BY
LATE WEEK AS STRONG UPPER LEVEL LOW MOVES INTO THE PAC NW WITH THE
UPPER LEVEL RIDGE AXIS SHIFTING EAST OF THE NORTHERN PLAINS BY
EARLY WEEKEND. MAX TEMPS MODERATE BY LATE WEEK...STILL ABOVE
NORMAL IN THE UPPER 80S...WITH INCREASING CHANCES OF
SHOWERS/THUNDERSTORMS INTO THE WEEKEND AS UPPER LEVEL RIDGE BREAKS
DOWN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 334 AM CDT SUN AUG 9 2015
THE MAIN HAZARD TO AVIATION WILL BE POSSIBLE MVFR CONDITIONS IN
CLOUDS AND RAIN ACROSS SOUTHWEST NORTH DAKOTA TODAY. OTHERWISE
CONDITIONS WILL REMAIN VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SCHECK
LONG TERM...JNS
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1244 AM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1238 AM CDT SUN AUG 9 2015
THE MAIN FOCUS THIS MORNING IS ON RAIN SHOWERS.
SCATTERED LIGHT TO MODERATE RAIN SHOWERS ARE MEANDERING EASTWARD
ALONG AND SOUTH OF I-94. THE 02-04 UTC HRRR RUNS SEEM TO HAVE A
GOOD HANDLE ON THE TIMING AND EVOLUTION OF THIS EVENT...SO UPDATED
PRECIPITATION CHANCES WERE DERIVED FROM A TIME-LAGGED BLEND OF
THOSE RUNS.
UPDATE ISSUED AT 956 PM CDT SAT AUG 8 2015
MADE SOME POP CHANGES USING THE LATEST HRRR RUNS AND TRENDING
EARLY TOWARD THE RADAR. LIGHTNING IS SLOWLY CREEPING TOWARD THE
BORDER. LOOKS LIKE MUCH OF THE EARLY PRECIP SUFFERED FROM WEAK
FORCING AND EVAPORATION BELOW CLOUDS BASE. NOW LOOKS LIKE MORE
SUBSTANTIAL SHOWERS/THUNDERSTORMS WILL MOVE INTO SOUTHWEST ND AS
MIDNIGHT APPROACHES.
UPDATE ISSUED AT 646 PM CDT SAT AUG 8 2015
RADAR TRENDS SHOW SEVERAL BANDS OF PRECIPITATION MOVING INTO SOUTHWEST
AND SOUTH CENTRAL NORTH DAKOTA. SO FAR VERY LITTLE IF ANY APPEARS
TO BE REACHING THE GROUND AS OF 630 PM CDT. ONE REASON MAY BE THE
DRY SUBCLOUD LAYER RESULTING IN CONSIDERABLE EVAPORATION. EVENTUALLY
THERE WILL BE RAIN SOUTHWEST. WILL CONTINUE THE HIGHER POPS TREND
WITH TIME THIS EVENING ACROSS THE FAR SOUTHWEST AND SOUTH CENTRAL.
LITTLE RAIN WILL REACH THE AREA NORTH OF I94 EVEN THROUGH MUSH OF
THE DAY TOMORROW. SO FAR INSTABILITY IS SLIM SO REDUCED THE TREAT
FOR THUNDERSTORMS TO WIDELY SCATTERED.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 238 PM CDT SAT AUG 8 2015
FORECAST HIGHLIGHTS IN THE SHORT TERM PERIOD WILL BE CHANCES FOR
SHOWERS AND ISOLATED THUNDERSTORMS SOUTHWEST THIS
AFTERNOON...EXPANDING INTO THE SOUTH CENTRAL TONIGHT...WITH
THUNDERSTORM CHANCES CONTINUING ON SUNDAY ACROSS THE SOUTH.
CURRENTLY...TRANSITIONAL FLOW ALOFT WAS OCCURRING OVER SOUTHWESTERN
NORTH DAKOTA...FROM ZONAL/WEAK RIDGE ALOFT TO SOUTHWESTERLY. THE
STACKED LOW PRESSURE SYSTEM OVER MANITOBA CONTINUED MOVING EAST
TODAY AS AN UPPER LEVEL SHORTWAVE TROUGH PROGRESSES NORTHEASTWARD
OUT OF IDAHO ACROSS WYOMING AND MONTANA. THIS IDAHO SHORTWAVE WAS
UNDERCUTTING A LARGER WESTERN RIDGE THAT EXTENDED NORTHWARD OVER THE
CANADIAN ROCKIES. MEANWHILE AT THE SURFACE...A COLD FRONT EXTENDING
FROM THE MANITOBA LOW HAD MOVED THROUGH ALL OF WESTERN AND MOST OF
CENTRAL NORTH DAKOTA. DEWPOINTS WERE IN THE 40S IN THE WEST...50S
CENTRAL...WITH A VERY HUMID 70 READING AT OAKES SOUTH OF JAMESTOWN.
THE MODELS ARE IN AGREEMENT THAT THE ZONAL/WEAK RIDGING ALOFT WAS
SLOWING THE PROGRESSION OF SHOWERS INTO SOUTHWESTERN NORTH DAKOTA
EARLIER TODAY. LATEST REGIONAL RADAR LOOPS INDICATE LIGHT SHOWERS
MOVING INTO THE BOWMAN/HETTINGER AREAS. CONFIDENCE IS LOW AS TO
WHETHER THIS REFLECTS SHOWERS REACHING THE GROUND OR VIRGA. IN ANY
CASE...THE MODELS ARE INDICATING THE VIGOROUS SHORTWAVE MOVING INTO
THE SOUTHWEST WILL CONTINUE TO PROVIDE MID-LEVEL BASED SHOWERS
THROUGH TONIGHT AND INTO SUNDAY. AT SOME POINT...SHOWERS SHOULD
REACH THE GROUND AS THE CONVECTION CONTINUES ITS ADVANCEMENT AND
FORCING INCREASES.
THE MODELS ALSO INDICATE THAT RIDGING ALOFT OVER THE CANADIAN
ROCKIES SHOULD LIMIT THE NORTHERN EXTENT OF THE CONVECTION...AND
ONLY THE SOUTHERN HALF OF WESTERN AND CENTRAL NORTH DAKOTA SHOULD
HAVE CHANCES OF SHOWERS/THUNDER.
LIMITED CAPE THIS EVENING AND OVERNIGHT...BUT CAPE INCREASES ON
SUNDAY. THEREFORE ISOLATED THUNDERSTORMS EXPECTED WITH SHOWERS
TONIGHT...WITH CHANCES OF SHOWERS AND THUNDERSTORMS SUNDAY. BEST
CHANCES ALONG THE SOUTHERN TIER OF COUNTIES.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 238 PM CDT SAT AUG 8 2015
THE LONG TERM LOOKS WARM AND MAINLY DRY...WITH SLIGHT CHANCES FOR
THUNDERSTORMS LATER NEXT WEEK.
THE MODELS ARE IN FAIRLY GOOD AGREEMENT ABOUT BUILDING IN A HIGH
AMPLITUDE RIDGE ACROSS THE MOUNTAIN WEST. THE RIDGE IS EXPECTED
TO START BUILDING IN SUNDAY ACROSS THE WESTERN ROCKIES. BOTH THE
GFS AND ECMWF HAVE THE RIDGE EVER SO SLOWLY PROPAGATING EASTWARD
THROUGH NEXT WEEK. SOME OF THE WARMEST AIR OF THE YEAR IS POSSIBLE
ACROSS WESTERN NORTH DAKOTA THIS WEEK. TEMPERATURES IN THE UPPER
90S SEEM LIKELY...WITH SOME 100S POSSIBLE. SEVERAL FAST MOVING
SHORTWAVE TROUGHS WILL LIKELY TRAVERSE THE RIDGE MID/LATE NEXT
WEEK. HOWEVER...TIMING OF INDIVIDUAL WAVES AND ASSOCIATED
PRECIPITATION IS DIFFICULT AT BEST THIS FAR OUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1238 AM CDT SUN AUG 9 2015
THE MAIN HAZARD TO AVIATION WILL BE POSSIBLE MVFR CONDITIONS IN
CLOUDS AND RAIN ACROSS SOUTHWEST NORTH DAKOTA TONIGHT. OTHERWISE
CONDITIONS WILL REMAIN VFR.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SCHECK
SHORT TERM...JV
LONG TERM...AJ
AVIATION...SCHECK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1047 AM EDT SUN AUG 9 2015
.SYNOPSIS...
WEAK FLOW CONTINUES TODAY. LOW PRESSURE SYSTEM PASSES
NORTH MONDAY INTO MONDAY NIGHT. MID/UPPER LEVEL TROF AXIS CROSSES
TUESDAY. DRIER AIR WITH COOLER NIGHTS WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE. NO SIGNIFICANT CHANGES.
PREVIOUS DISCUSSION...
ANOTHER EARLY MORNING WITH AREAS OF CLOUDS VERSUS VALLEY FOG IN THE
WEAK DOG DAY WIND FLOW. A FEW SHOWERS REDEVELOPED OVER THE CENTRAL
WV MOUNTAINS BETWEEN 06Z AND 08Z PROBABLY AIDED BY A WEAK MID LEVEL
VORT MAX INDICATED ON RAP SOLUTION. BY 10Z FIGURING ANY SURVIVING
SHOWER WOULD BE IN VIRGINIA.
LESS INSTABILITY INDICATED THIS AFTERNOON OVER THE MOUNTAIN COUNTIES
COMPARED TO SATURDAY...BUT WITH THE WEAK FLOW AND SOME WEAK E TO W
COMPONENT IN THE LOW LEVELS ON THE EASTERN SLOPES...WILL LEAVE MORE
CLOUDS AND THE 20/30 POPS FOR AFTERNOON AND EARLY EVENING CONVECTION.
STRONGER BUT WEAKENING 500 MB VORT MAXIMUMS STREAK SE FROM NRN IL
AND INDIANA TODAY. THIS SHOULD INCREASE HIGH CLOUDS IN SE OHIO THIS
AFTERNOON...AND MAY HOLD TEMP DOWN A DEGREE OR 2. WILL BE SLOWER
INCREASING POPS IN NE KY AND HTS VCNTY BUT WILL ACTUALLY BE A BIT
FASTER INCREASING POPS FURTHER TO THE NORTH THIS EVENING...IN SE
OHIO...THEN TOWARD THE MID OHIO VALLEY INCLUDING PKB.
00Z MODEL SOLUTIONS DROP WEAKENING 500 MB VORT MAXIMUMS SE THRU CWA
OVERNIGHT SUNDAY NIGHT. QUESTION IS HOW FAST TO INCREASE POPS
FURTHER E...IN RESPONSE TO THESE FEATURES. 00Z GFS SEEMS A BIT
GENEROUS ON LIGHT PCPN FURTHER EAST AND SOUTH OVERNIGHT. WILL HAVE
20 POPS REACHING EKN TO CRW LINE TOWARD DAWN...CHANCE POPS FURTHER
WEST.
WITH INCREASING LAYERED CLOUDS OVERNIGHT...KEPT TEMPS A BIT HIGHER IN
THE MID OHIO VALLEY. STILL THINK THE SRN WV INTO SW VA COAL FIELD
COUNTIES COULD SEE VALLEY FOG OVERNIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS IN DECENT AGREEMENT ON MOVEMENT OF SURFACE LOW ACROSS LAKES
ERIE AND ONTARIO THROUGH TUESDAY. THE ECMWF IS THE FASTEST...AND NAM
THE SLOWEST MOVING THE LOW NORTHEAST...WITH THE GFS IN THE MIDDLE.
WARM FRONT WILL LIFT ACROSS CWA MONDAY...AND HAVE LIKELY POPS.
MODELS HAVE TRENDED FARTHER NORTH WITH THE SURFACE LOW...AND NOW
SHOW THE BEST SHEAR REMAINING NORTH OF CWA FOR THE DAY MONDAY. WITH
CONVECTION STARTING EARLY...SOME QUESTION AS TO HOW ORGANIZED THINGS
CAN GET WITH LACK OF STRONG DIURNAL HEATING. PWAT VALUES OF 1.5 TO 2
INCHES WILL LEAD TO DOWNPOURS...BUT THE GROUND HAS DRIED OUT SO DO
NOT ENVISION WIDESPREAD WATER CONCERNS.
MODEL TIMING DIFFERENCES DO HAVE SOME IMPACT ON TIMING THE COLD
FRONT PASSAGE...FOR NOW TRENDED TOWARD THE SLOWER SIDE OF THE
ENVELOPE WITH THE FRONT CROSSING SE OHIO LATE MONDAY NIGHT AND
EXITING THE WV MOUNTAINS EARLY TUESDAY AFTERNOON.
MID AND UPPER LEVEL TROUGH FOLLOW THE COLD FRONT...SO LINGERED
SHOWERS AND CLOUDS INTO TUESDAY EVENING ACROSS THE WEST...AND INTO
TUESDAY NIGHT IN THE WV MOUNTAINOUS COUNTIES. MODELS SHOW UPPER
TROUGH CLOSING OFF ON WEDNESDAY OVER SOUTHERN QUEBEC. WITH NW FLOW
AND WRAPAROUND MOISTURE INCLUDED ISOLATED SHOWERS IN THE NE CWA
WEDNESDAY. MAY EVENTUALLY NEED TO EXPAND THESE WESTWARD...JUST
DEPENDS ON HOW QUICKLY LOW LEVELS DRY OUT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
TIL 00Z...SCT-BKN 2500-4000 FEET AGL ABV 1500 FEET...ELSEWHERE
SCT-BKN 4000-5000 FEET AGL. JUST A FEW MOUNTAIN SHOWERS OR
THUNDERSTORMS 18Z THROUGH 00Z. WILL LEAVE CONFIDENCE AT
MEDIUM...WEAKENING 500 MB VORT MAXIMUMS OVERNIGHT SUNDAY NIGHT. DO
HAVE CHANCE OF A SHOWER OR THUNDERSTORM INTO SE OHIO AFTER
21Z....BUT DIFFICULT TO FIGURE IF SHOWERS WILL CONTINUE TO SURVIVE
AND MOVE DEEPER INTO WV OVERNIGHT.
WILL MENTION SOME SHOWERS PKB AFTER 04Z AND CKB AFTER 08Z MONDAY.
LAYERED CL0UDS AT 5 TO 10 THSD FT INCREASING IN OHIO VALLEY
COUNTIES FOR 00Z TO 06Z MONDAY...THEN AREA WIDE 06Z TO 12Z MONDAY.
VSBY NEAR 5 MILES IN ANY SHOWER SOUTHEAST OHIO AND INTO WV
OVERNIGHT.
DO HAVE PATCHY VALLEY FOG FORMING MAINLY E AND S OF CRW 06Z TO 12Z
MONDAY...INCLUDING THE SOUTHERN WV COAL FIELD VALLEYS. IF CLOUDS ARE
SLOW...THEN FOG AT EKN TOO.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: COVERAGE OF SHOWERS 00Z TO 12Z MONDAY MAY BE
MORE THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 12 13 14 15 16 17 18 19 20 21 22 23
EDT 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
CRW CONSISTENCY L L H H H H H H H H H H
HTS CONSISTENCY L H H H H H H H H H H H
BKW CONSISTENCY H H H H H H M M H H H H
EKN CONSISTENCY L L H H H H H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY L L H H H H H H H H H H
AFTER 12Z MONDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY AND MONDAY
NIGHT...THEN IN LINGERING LOW CEILINGS AND SHOWERS TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB/JMV
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB/JMV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
625 AM EDT SUN AUG 9 2015
.SYNOPSIS...
WEAK FLOW CONTINUES TODAY. LOW PRESSURE SYSTEM PASSES
NORTH MONDAY INTO MONDAY NIGHT. MID/UPPER LEVEL TROF AXIS CROSSES
TUESDAY. DRIER AIR WITH COOLER NIGHTS WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ANOTHER EARLY MORNING WITH AREAS OF CLOUDS VERSUS VALLEY FOG IN THE
WEAK DOG DAY WIND FLOW. A FEW SHOWERS REDEVELOPED OVER THE CENTRAL
WV MOUNTAINS BETWEEN 06Z AND 08Z PROBABLY AIDED BY A WEAK MID LEVEL
VORT MAX INDICATED ON RAP SOLUTION. BY 10Z FIGURING ANY SURVIVING
SHOWER WOULD BE IN VIRGINIA.
LESS INSTABILITY INDICATED THIS AFTERNOON OVER THE MOUNTAIN COUNTIES
COMPARED TO SATURDAY...BUT WITH THE WEAK FLOW AND SOME WEAK E TO W
COMPONENT IN THE LOW LEVELS ON THE EASTERN SLOPES...WILL LEAVE MORE
CLOUDS AND THE 20/30 POPS FOR AFTERNOON AND EARLY EVENING CONVECTION.
STRONGER BUT WEAKENING 500 MB VORT MAXIMUMS STREAK SE FROM NRN IL
AND INDIANA TODAY. THIS SHOULD INCREASE HIGH CLOUDS IN SE OHIO THIS
AFTERNOON...AND MAY HOLD TEMP DOWN A DEGREE OR 2. WILL BE SLOWER
INCREASING POPS IN NE KY AND HTS VCNTY BUT WILL ACTUALLY BE A BIT
FASTER INCREASING POPS FURTHER TO THE NORTH THIS EVENING...IN SE
OHIO...THEN TOWARD THE MID OHIO VALLEY INCLUDING PKB.
00Z MODEL SOLUTIONS DROP WEAKENING 500 MB VORT MAXIMUMS SE THRU CWA
OVERNIGHT SUNDAY NIGHT. QUESTION IS HOW FAST TO INCREASE POPS
FURTHER E...IN RESPONSE TO THESE FEATURES. 00Z GFS SEEMS A BIT
GENEROUS ON LIGHT PCPN FURTHER EAST AND SOUTH OVERNIGHT. WILL HAVE
20 POPS REACHING EKN TO CRW LINE TOWARD DAWN...CHANCE POPS FURTHER
WEST.
WITH INCREASING LAYERED CLOUDS OVERNIGHT...KEPT TEMPS A BIT HIGHER IN
THE MID OHIO VALLEY. STILL THINK THE SRN WV INTO SW VA COAL FIELD
COUNTIES COULD SEE VALLEY FOG OVERNIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS IN DECENT AGREEMENT ON MOVEMENT OF SURFACE LOW ACROSS LAKES
ERIE AND ONTARIO THROUGH TUESDAY. THE ECMWF IS THE FASTEST...AND NAM
THE SLOWEST MOVING THE LOW NORTHEAST...WITH THE GFS IN THE MIDDLE.
WARM FRONT WILL LIFT ACROSS CWA MONDAY...AND HAVE LIKELY POPS.
MODELS HAVE TRENDED FARTHER NORTH WITH THE SURFACE LOW...AND NOW
SHOW THE BEST SHEAR REMAINING NORTH OF CWA FOR THE DAY MONDAY. WITH
CONVECTION STARTING EARLY...SOME QUESTION AS TO HOW ORGANIZED THINGS
CAN GET WITH LACK OF STRONG DIURNAL HEATING. PWAT VALUES OF 1.5 TO 2
INCHES WILL LEAD TO DOWNPOURS...BUT THE GROUND HAS DRIED OUT SO DO
NOT ENVISION WIDESPREAD WATER CONCERNS.
MODEL TIMING DIFFERENCES DO HAVE SOME IMPACT ON TIMING THE COLD
FRONT PASSAGE...FOR NOW TRENDED TOWARD THE SLOWER SIDE OF THE
ENVELOPE WITH THE FRONT CROSSING SE OHIO LATE MONDAY NIGHT AND
EXITING THE WV MOUNTAINS EARLY TUESDAY AFTERNOON.
MID AND UPPER LEVEL TROUGH FOLLOW THE COLD FRONT...SO LINGERED
SHOWERS AND CLOUDS INTO TUESDAY EVENING ACROSS THE WEST...AND INTO
TUESDAY NIGHT IN THE WV MOUNTAINOUS COUNTIES. MODELS SHOW UPPER
TROUGH CLOSING OFF ON WEDNESDAY OVER SOUTHERN QUEBEC. WITH NW FLOW
AND WRAPAROUND MOISTURE INCLUDED ISOLATED SHOWERS IN THE NE CWA
WEDNESDAY. MAY EVENTUALLY NEED TO EXPAND THESE WESTWARD...JUST
DEPENDS ON HOW QUICKLY LOW LEVELS DRY OUT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
LINGERING VALLEY FOG SHOULD DISSIPATE AROUND 13Z.
WILL LEAVE CONFIDENCE AT MEDIUM...WEAKENING 500 MB VORT MAXIMUMS
OVERNIGHT SUNDAY NIGHT. DO HAVE CHANCE OF A SHOWER OR THUNDERSTORM
INTO SE OHIO AFTER 21Z....BUT DIFFICULT TO FIGURE IF SHOWERS WILL
CONTINUE TO SURVIVE AND MOVE DEEPER INTO WV OVERNIGHT.
WILL MENTION SOME SHOWERS PKB AFTER 04Z AND CKB AFTER 08Z MONDAY.
LIKE SATURDAY...MORE DAYTIME CU FIGURED OVER THE MOUNTAIN COUNTIES WITH
CEILINGS 2 TO 3 THSD FT...WHILE MOSTLY SCT CU OVER LOWLANDS AT 3 TO
5 THSD FT AGL. THICKENING CIRRUS CLOUDS ABOVE...ADVANCING ESE AFTER
17Z. A FEW MOUNTAIN SHOWERS OR THUNDERSTORMS 17Z SUNDAY THROUGH 02Z
MONDAY.
LAYERED CL0UDS AT 5 TO 10 THSD FT INCREASING IN OHIO VALLEY COUNTIES
FOR 00Z TO 06Z MONDAY...THEN AREA WIDE 06Z TO 12Z MONDAY. VSBY NEAR
5 MILES IN ANY SHOWER SOUTHEAST OHIO AND INTO WV OVERNIGHT.
DO HAVE PATCHY VALLEY FOG FORMING MAINLY E AND S OF CRW 06Z TO 12Z
MONDAY...INCLUDING THE SOUTHERN WV COAL FIELD VALLEYS. IF CLOUDS ARE
SLOW...THEN FOG AT EKN TOO.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: COVERAGE OF SHOWERS 00Z TO 12Z MONDAY. MAY BE
MORE THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 08/09/15
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY L L L L L H H H H H H H
HTS CONSISTENCY L L L L H H H H H H H H
BKW CONSISTENCY H H H H H H H H H M M H
EKN CONSISTENCY L L L L L H H H H H H H
PKB CONSISTENCY M M M M H H H H H H H H
CKB CONSISTENCY L L L L L H H H H H H H
AFTER 12Z MONDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY AND MONDAY
NIGHT...THEN IN LINGERING LOW CEILINGS AND SHOWERS TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
401 AM EDT SUN AUG 9 2015
.SYNOPSIS... WEAK FLOW CONTINUES TODAY. LOW PRESSURE SYSTEM PASSES
NORTH MONDAY INTO MONDAY NIGHT. MID/UPPER LEVEL TROF AXIS CROSSES
TUESDAY. DRIER AIR WITH COOLER NIGHTS WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ANOTHER EARLY MORNING WITH AREAS OF CLOUDS VERSUS VALLEY FOG IN THE
WEAK DOG DAY WIND FLOW. A FEW SHOWERS REDEVELOPED OVER THE CENTRAL
WV MOUNTAINS BETWEEN 06Z AND 08Z PROBABLY AIDED BY A WEAK MID LEVEL
VORT MAX INDICATED ON RAP SOLUTION. BY 10Z FIGURING ANY SURVIVING
SHOWER WOULD BE IN VIRGINIA.
LESS INSTABILITY INDICATED THIS AFTERNOON OVER THE MOUNTAIN COUNTIES
COMPARED TO SATURDAY...BUT WITH THE WEAK FLOW AND SOME WEAK E TO W
COMPONENT IN THE LOW LEVELS ON THE EASTERN SLOPES...WILL LEAVE MORE
CLOUDS AND THE 20/30 POPS FOR AFTERNOON AND EARLY EVENING CONVECTION.
STRONGER BUT WEAKENING 500 MB VORT MAXIMUMS STREAK SE FROM NRN IL
AND INDIANA TODAY. THIS SHOULD INCREASE HIGH CLOUDS IN SE OHIO THIS
AFTERNOON...AND MAY HOLD TEMP DOWN A DEGREE OR 2. WILL BE SLOWER
INCREASING POPS IN NE KY AND HTS VCNTY BUT WILL ACTUALLY BE A BIT
FASTER INCREASING POPS FURTHER TO THE NORTH THIS EVENING...IN SE
OHIO...THEN TOWARD THE MID OHIO VALLEY INCLUDING PKB.
00Z MODEL SOLUTIONS DROP WEAKENING 500 MB VORT MAXIMUMS SE THRU CWA
OVERNIGHT SUNDAY NIGHT. QUESTION IS HOW FAST TO INCREASE POPS
FURTHER E...IN RESPONSE TO THESE FEATURES. 00Z GFS SEEMS A BIT
GENEROUS ON LIGHT PCPN FURTHER EAST AND SOUTH OVERNIGHT. WILL HAVE
20 POPS REACHING EKN TO CRW LINE TOWARD DAWN...CHANCE POPS FURTHER
WEST.
WITH INCREASING LAYERED CLOUDS OVERNIGHT...KEPT TEMPS A BIT HIGHER IN
THE MID OHIO VALLEY. STILL THINK THE SRN WV INTO SW VA COAL FIELD
COUNTIES COULD SEE VALLEY FOG OVERNIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
MODELS IN DECENT AGREEMENT ON MOVEMENT OF SURFACE LOW ACROSS LAKES
ERIE AND ONTARIO THROUGH TUESDAY. THE ECMWF IS THE FASTEST...AND NAM
THE SLOWEST MOVING THE LOW NORTHEAST...WITH THE GFS IN THE MIDDLE.
WARM FRONT WILL LIFT ACROSS CWA MONDAY...AND HAVE LIKELY POPS.
MODELS HAVE TRENDED FARTHER NORTH WITH THE SURFACE LOW...AND NOW
SHOW THE BEST SHEAR REMAINING NORTH OF CWA FOR THE DAY MONDAY. WITH
CONVECTION STARTING EARLY...SOME QUESTION AS TO HOW ORGANIZED THINGS
CAN GET WITH LACK OF STRONG DIURNAL HEATING. PWAT VALUES OF 1.5 TO 2
INCHES WILL LEAD TO DOWNPOURS...BUT THE GROUND HAS DRIED OUT SO DO
NOT ENVISION WIDESPREAD WATER CONCERNS.
MODEL TIMING DIFFERENCES DO HAVE SOME IMPACT ON TIMING THE COLD
FRONT PASSAGE...FOR NOW TRENDED TOWARD THE SLOWER SIDE OF THE
ENVELOPE WITH THE FRONT CROSSING SE OHIO LATE MONDAY NIGHT AND
EXITING THE WV MOUNTAINS EARLY TUESDAY AFTERNOON.
MID AND UPPER LEVEL TROUGH FOLLOW THE COLD FRONT...SO LINGERED
SHOWERS AND CLOUDS INTO TUESDAY EVENING ACROSS THE WEST...AND INTO
TUESDAY NIGHT IN THE WV MOUNTAINOUS COUNTIES. MODELS SHOW UPPER
TROUGH CLOSING OFF ON WEDNESDAY OVER SOUTHERN QUEBEC. WITH NW FLOW
AND WRAPAROUND MOISTURE INCLUDED ISOLATED SHOWERS IN THE NE CWA
WEDNESDAY. MAY EVENTUALLY NEED TO EXPAND THESE WESTWARD...JUST
DEPENDS ON HOW QUICKLY LOW LEVELS DRY OUT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
ANOTHER 06Z TO 12Z TIME FRAME WITH CLOUDS AND A FEW LINGERING
MOUNTAIN SHOWERS WHILE VALLEY FOG FORMS WHERE CLOUDS BREAK UP.
NEAR 06Z...FOG HAS ALREADY FORMED S OF CRW IN DEEP SRN WV COAL
FIELD COUNTIES.
CONFIDENCE SET AT MEDIUM...MAINLY FOR HOW FOG VERSUS CLOUDS WILL REACT
THROUGH 13Z THIS MORNING.
WEAK WIND FLOW ALSO CONTINUES TODAY.
LIKE SATURDAY...MORE DAYTIME CU FIGURED OVER THE MOUNTAIN COUNTIES WITH
CEILINGS 2 TO 3 THSD FT...WHILE MOSTLY SCT CU OVER LOWLANDS AT 3 TO 5
THSD FT AGL. FEW MOUNTAIN SHOWERS OR THUNDERSTORMS 17Z SUNDAY
THROUGH 02Z MONDAY.
LAYERED CL0UDS AT 5 TO 10 THSD FT INCREASING IN OHIO VALLEY COUNTIES
FOR 00Z TO 06Z MONDAY...WITH POSSIBLE SHOWER INTO SOUTHEAST OHIO
AND VSBY NEAR 5 MILES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z MONDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: CLOUD COVER/FOG VARIABILITY 06Z TO 13Z SUNDAY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SUN 08/09/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H M L L L L L H H H H
HTS CONSISTENCY H M M L L L L H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H M M L L L L L H H H H
PKB CONSISTENCY H H M M M M M H H H H H
CKB CONSISTENCY H M L L L L L L H H H H
AFTER 06Z MONDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS MONDAY AND MONDAY
NIGHT...THEN IN LINGERING LOW CEILINGS AND SHOWERS TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS MEDFORD OR
551 PM PDT MON AUG 10 2015
.UPDATE...AN UPDATE HAS BEEN ISSUED TO REDUCE THE PROBABILITY OF
THUNDERSTORMS TONIGHT WITH THE 18Z NAM AND LATEST HIGH-RESOLUTION
HRR/RAP DATA SHOWING ACTIVITY TO BE LIMITED TO A SLIGHT CHANCE OF
THUNDERSTORMS. THE PROBABILITY FOR THUNDERSTORMS LOOKS TO BE HIGHER
THIS EVENING IN THE NORTHERN HALF OF THE OREGON CASCADES. EARLIER
MODELS SEEM TO HAVE MISJUDGED THE STRENGTH OF A CAPPING INVERSION
AROUND 13,000 FEET MSL AND THE GREATER COVERAGE OF HIGH LEVEL
CIRRUS AND CIRROCUMULUS CLOUDS HINDERED HEATING.
ALSO, THE AVIATION DISCUSSION HAS BEEN UPDATED.
&&
.AVIATION...FOR THE 11/00Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE THIS EVENING...THEN PERSIST
THROUGH MID-MORNING TUESDAY. INLAND...VFR CONDITIONS WILL PREVAIL
THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN SMOKE.
ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON WITH THE GREATER
COVERAGE OVER THE CASCADES AND SISKIYOUS...CONTINUING INTO THE
MORNING WEST OF THE CASCADES. STORMS MAY BRING ERRATIC AND GUSTY
WINDS AND LOCAL OBSCURATION OF HIGHER TERRAIN. -BPN
&&
.MARINE...UPDATED 230 PM PDT MONDAY 10 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN CALM WINDS AND SEAS OVER THE NEXT
SEVERAL DAYS, ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS TONIGHT INTO EARLY TUESDAY. A
THERMAL TROUGH WILL DEVELOP NEAR THE COAST FRIDAY AND SATURDAY,
BRINGING WITH IT STRONG NORTH WINDS AND CHOPPY SEAS, ESPECIALLY IN
THE OUTER WATERS SOUTH OF CAPE BLANCO. ALTHOUGH STILL TOO FAR OUT IN
RANGE TO BE CERTAIN, GALES AND VERY STEEP SEAS ARE POSSIBLE THIS
WEEKEND INTO EARLY NEXT WEEK. -BPN
&&
.PREV DISCUSSION... /ISSUED 231 PM PDT MON AUG 10 2015/
DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER LOW MARCHING
SOUTH ALONG 130 W. IT ALSO SHOWS A WEAK SHORTWAVE MOVING INTO
SOUTHWEST OREGON BRINGING HIGH AND MID LEVEL CLOUDS WHICH WILL
CONTINUE TO MOVE NORTHEAST. THE STRONGER SHORTWAVE THAT MOVED
THROUGH LAKE AND EASTERN KLAMATH COUNTY HAS MOVED NORTH OF OUR AREA
AND INCREASED LIGHTNING STRIKES HAVE SHOWN UP IN NORTHEAST OREGON
AND TOWARDS THE BLUE MOUNTAINS. GENERALLY CLEAR SKIES ARE IN ITS
WAKE, BUT CUMULUS ARE STARTING TO BUILD UP OVER THE HIGHER TERRAIN
ALONG AND EAST OF THE CASCADES AND NORTHERN CAL.
LOOKING AT DATA SUGGEST THE BEST CHANCE FOR SCATTERED THUNDERSTORMS
WILL BE LATE THIS AFTERNOON AND EVENING AND MOST CENTERED OVER THE
CASCADES. THE MODELS SHOW THE LOWEST LI`S AND HIGHEST BOUNDARY LAYER
CAPE VALUES AND THETA E CONVERGENCE IN THESE AREAS LATE THIS
AFTERNOON. IN ADDITION THE 700 MB WINDS AND THE 700-500MB WINDS WILL
BE FROM THE SOUTH, THEN SHIFT EVER SO SLIGHTLY TO THE SOUTH TO
SOUTHWEST THIS EVENING. THEREFORE WE THINK THE MAJORITY OF
THUNDERSTORMS WILL REMAIN IN THESE AREAS LATE THIS AFTERNOON AND
EVENING. HOWEVER WINDS ALOFT WILL BE STRONGER, THEREFORE STORMS THAT
FORM OVER WESTERN SISKIYOUS COUNTY AND SISKIYOU MOUNTAINS WILL GET
CARRIED NORTH INTO THE WEST SIDE VALLEYS, BUT THEY WILL BE RUNNING
IN AN ENVIRONMENT THAT IS LESS UNSTABLE AND ALSO WITH LESS MID LEVEL
MOISTURE. ALSO STORMS THAT FORM OVER THE CASCADES COULD GET PULLED
SLIGHTLY WESTWARD AND SCATTERED STORMS ARE POSSIBLE ALONG THE
FOOTHILLS OF THE CASCADES IN EASTERN DOUGLAS COUNTY.
OF NOTE THE PAST SEVERAL RUNS OF HIGH RES HRRR MODEL (WHICH UPDATES
HOURLY) CONTINUES TO SHOW VERY LITTLE ACTIVITY FROM THE CASCADES
WEST. IT ACTUALLY SHOWS A FRONTAL BOUNDARY ARRIVING AT THE COAST BY
THIS EVENING USHERING MORE STABLE CONDITIONS BRINGING LIGHT RAIN
WITH MOST OF THE CONVECTION IN MODOC AND LAKE COUNTY. MOST OF THE
CONVECTIVE FEEDBACK IS EAST OF THE CASCADES IN PARTS OF KLAMATH AND
LAKE COUNTY. NOT SURE IF THIS IS CORRECT, BUT IT MAY BE ON TO
SOMETHING GIVEN THE CONSISTENCY FROM RUN TO RUN. SO ITS ENTIRELY
POSSIBLE NOT MUCH WILL HAPPEN WEST OF THE CASCADES.
TONIGHT, THE MODELS ARE IN FRIARLY GOOD AGREEMENT SHOWING WINDS AT
700 AND 700-500MB REMAIN SOUTH TO SOUTHWEST. THE NAM SHOWS MORE OF A
SOUTHEAST COMPONENT OVERNIGHT TONIGHT, BUT THE GFS DOES NOT. THE NAM
SHOWS LIFTED INDICES (LI`S) LOWERING TO AROUND -5 C ALONG THE
COOS/DOUGLAS COUNTY LINE, BUT SUSPECT THAT MAY BE OVERDONE. IN
CONTRAST THE GFS SHOWS LI`S AROUND -1C. THE NAM CONTINUES TO SHOW A
SHORTWAVE MOVING WEST OF THE CASCADES OVERNIGHT TONIGHT, BUT THE GFS
IS MUCH WEAKER. BECAUSE OF THE ABOVE MENTIONED REASONS, WE THINK
THERE WILL BE NOCTURNAL STORMS WEST OF THE CASCADES, BUT THEY WILL
BE ISOLATED.
ON TUESDAY MOST OF THE INSTABILITY WILL BE WEST OF THE CASCADES.
HOWEVER WE`LL ALSO HAVE A MARINE INFLUENCE NEAR THE COAST WHICH
SHOULD STABILIZE THINGS SOME, SO WE DON`T THINK THUNDERSTORMS WILL
BE A CONCERN THERE. SHORTWAVES WILL ROTATE IN FROM THE SOUTHEAST
AHEAD OF THE UPPER LOW AND THIS IN COMBINATION WITH LOWEST LI`S AND
HIGHEST BL CAPE CENTERED FROM WESTERN SISKIYOU COUNTY NORTHEAST
TOWARDS EASTERN DOUGLAS COUNTY COULD BE ENOUGH TO GENERATE ISOLATED
THUNDERSTORMS. OF NOTE THE HIGHEST BL CAPE VALUES AND LOWEST LI`S
ARE IN THE NORTHERN CASCADES NORTH OF CRATER LAKE, SO THERE`S A
CHANCE FOR SCATTERED STORMS THERE.
NOT MUCH CHANGE IN THE PATTERN IS EXPECTED TUESDAY NIGHT THROUGH
WEDNESDAY. THE UPPER LOW WILL REMAIN NEARLY STATIONARY, THEN SLOWLY
MOVE NORTHWARD WEDNESDAY AFTERNOON AS THE UPSTREAM UPPER TROUGH
MOVES TOWARDS WESTERN B.C. THE MODELS PUT THE GREATEST INSTABILITY
ALONG THE CASCADES AND WESTERN SISKIYOU COUNTY TUESDAY NIGHT, THEN
BECOMING MORE STABLE ON WEDNESDAY, THEREFORE THE CONCERN FOR
NOCTURNAL STORMS EXIST AGAIN TUESDAY NIGHT, THEN THE THREAT OF
STORMS SHIFTS NORTH WEDNESDAY.
THE UPPER LOW WILL MOVE INLAND AND ACROSS THE AREA THURSDAY
AFTERNOON AND WE EXPECT A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS
ALONG WITH A BRIEF COOL DOWN. THE UPPER LOW WILL FINALLY KICK
NORTHEAST OF THE AREA FRIDAY AFTERNOON AND A WEAK TROUGH REMAINS,
BUT IT WILL STAY DRY WITH MILDER TEMPERATURES.
WINDS WILL BE ANOTHER CONCERN, PARTICULARLY OVER THE HIGHER TERRAIN
ALONG AND EAST OF THE CASCADES THIS AFTERNOON THROUGH AT LEAST
THURSDAY AFTERNOON. ALSO WINDS ARE ALIGNED UP PRETTY WELL IN THE
SHASTA VALLEY WITH 700MB WINDS BETWEEN 25-35 KTS, SOME OF WHICH
COULD MIX DOWN NEAR THE SURFACE. THE MODEL GUIDANCE SHOWS WIND GUSTS
BETWEEN 45-50 KTS, BUT SUSPECT THIS MAY BE A BIT OVERDONE. THIS IS
BECAUSE THE PRESSURE GRADIENT IS NOT STRONG LIKE WE TYPICALLY SEE IN
THE WINTER THAT WOULD PRODUCE WIND GUST OF THIS MAGNITUDE. SO WHILE
WE EXPECT WINDS TO INCREASE AROUND THE WEED AREA, THEY WON`T BE
ENOUGH TO REACH ADVISORY CRITERIA.
A THERMAL TROUGH WILL DEVELOP ALONG THE COAST FRIDAY NIGHT THROUGH
SATURDAY WITH INCREASING OFFSHORE FLOW. THE PATTERN THAT IS SETTING
UP IS FAVORABLE FOR A CHETCO EFFECT AND THE HIGH TEMPERATURES IN
BROOKINGS COULD EASILY GET INTO THE MID TO UPPER 80S OR LOW 90S.
MEANWHILE TEMPERATURES WILL HEAT UP IN THE WEST SIDE VALLEYS WITH
READINGS IN THE LOWER TO MID 90S. DRY CONDITIONS CONTINUE SUNDAY AND
THE THERMAL TROUGH WILL SHIFT INLAND OVER THE WEST SIDE VALLEYS WITH
TEMPERATURES EXPECTED TO BE IN THE MID 90S.
KEEP IN MIND WHILE THE MODELS REMAIN IN GOOD AGREEMENT WITH THE
OVERALL PATTERN THE NEXT FEW DAYS, THE MAIN CHALLENGE WILL BE
ADDRESSING THE DETAILS OF THE WEATHER, ESPECIALLY AS IT RELATES TO
THUNDERSTORM COVERAGE, SHOWERS AND PATCHY TO AREAS OF SMOKE.
CONFIDENCE REMAINS LOW REGARDING THE MOST FAVORABLE AREAS FOR
THUNDERSTORMS. THEREFORE DETAILS ON THIS COULD CHANGE FROM ONE DAY
TO THE NEXT SO STAY TUNED FOR THE LATEST UPDATES. -PETRUCELLI
FIRE WEATHER...UPDATED 230 PM PDT MONDAY 10 AUGUST 2015...SOUTHERLY
FLOW INCREASED TODAY...AND SO DID CLOUD COVER. THIS IS INHIBITING
THUNDERSTORM DEVELOPMENT OVER THE AREA...BUT SOME ARE STILL EXPECTED
TO DEVELOP. SCATTERED COVERAGE WILL EVENTUALLY DEVELOP OVER THE
CASCADES WITH ISOLATED COVERAGE OVER MOST OF THE OTHER INLAND AREAS.
ISOLATED THUNDERSTORMS MAY PERSIST THROUGH THE NIGHT...THEN BECOME
SCATTERED AGAIN OVER THE NORTHERN CASCADES TUESDAY AFTERNOON. GUSTY
SOUTH WINDS HAVE ALREADY DEVELOPED AND WILL CONTINUE THROUGH
THURSDAY...WHEN IT MAY BE ESPECIALLY WINDY ON THE EAST SIDE DUE TO
AN UPPER LEVEL TROUGH MOVING ONSHORE. AFTER THE TROUGH MOVES INLAND
..OFFSHORE LOW LEVEL FLOW WILL DEVELOP OVER THE COAST RANGE FRIDAY
NIGHT INTO SATURDAY NIGHT.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM 5 PM TO 11 PM PDT TUESDAY FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM TO 8 PM PDT TUESDAY FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
DW/MAP/BPN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1118 PM EDT MON AUG 10 2015
.SYNOPSIS...
A FRONTAL SYSTEM OVER THE OHIO VALLEY WILL MOVE THROUGH THE
REGION OVERNIGHT AND EARLY TUESDAY. COOLER AND DRIER AIR WILL
FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL REBOUND LATE
THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE MID
MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATE EVENING RADAR MOSAIC SHOWING WIDESPREAD SHRA/TSRA ACROSS NW
PA IN ADVANCE OF APPROACHING UPPER TROF. 02Z SPC MESOANALYSIS
STILL INDICATING SOME MODEST CAPES OF ARND 500 J/KG ACROSS
WESTERN PA...WHERE THERE WAS SOME SUNSHINE EARLIER TODAY. FURTHER
EAST...MOIST SERLY FLOW YIELDING MARINE LYR STRATUS BUT SHOWERS
HAVE YET TO REACH MOST OF CENTRAL PA AS OF 03Z.
EXPECT SHRA TO OVERSPREAD THE REGION FROM WEST TO EAST OVERNIGHT...AS
UPPER TROF AND PRECEDING LL JET/PLUME OF ANOMALOUS PWATS OVERSPREAD
THE STATE. SPC HAD EARLIER PLACED THE ALLEGHENY PLATEAU IN A MRGL
RISK AREA FOR SVR WX THIS EVENING. HOWEVER...GIVEN DIMINISHING
CAPES AND NEARLY NON-EXISTENT DCAPES...BELIEVE THE THREAT OF SVR
WX IS LOW. GREATER RISK WILL BE POSSIBILITY OF ISOLD FLOODING
ACROSS THE NW MTNS...WHERE LINGERING INSTABILITY...COMBINED WITH
SURGING PWATS...COULD PRODUCE LOCALIZED EXCESSIVE RAINFALL. HPC
HAS OUTLINED OUR NW COUNTIES FOR POTENTIALLY HEAVY RAINS. SHORT
TERM GUIDANCE SHOWS A PRETTY QUICK PROGRESSION ACROSS THE STATE OF
THE LOW LEVEL JET AND AXIS OF DEEPEST MOISTURE. WILL HAVE TO WATCH
FOR THE POTENTIAL FOR TRAINING CONVECTION IN THE MOISTURE-RICH
AIR MASS. SPC SSEO AND LATEST HRRR TARGET THE NW MTNS FOR
LOCALIZED AMTS 3+ INCHES. HAVE MENTIONED SLIGHT RISK OF FLOODING
ACROSS THIS AREA IN THE HWO...BUT GIVEN RECENT DRYNESS...FEEL ODDS
OF TRUE FLASH FLOODING NOT HIGH ENOUGH FOR A WATCH ATTM.
STRONG FRONTAL PASSAGE...ANOMALOUS PWATS AND LATEST GEFS/SREF
OUTPUT ALL SUPPORT NEAR 100 PCT POPS OVERNIGHT ACROSS ALL OF
CENTRAL PA. BEST CHANCE WILL COME BEFORE MIDNIGHT ACROSS THE
NW COUNTIES AND AFTER MIDNIGHT ELSEWHERE. SHORT TERM GUIDANCE
TIMES THE LOW LEVEL JET EAST OF THE ENTIRE REGION BY
12Z...RESULTING IN THE STEADIEST RAIN EXITING OUR EASTERN COUNTIES
SHORTLY AFTER DAWN. LOWS IN THE MID 60S TO LOWER 70S WILL FEEL
RATHER TROPICAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ANOMALOUS LL JET/PWATS WILL HAVE SHIFTED EAST OF THE AREA WITH
LEAD SHORTWAVE BY EARLY TUESDAY...BRINGING AN END TO THE BULK OF
THE RAINFALL BY ARND DAWN. HOWEVER...SFC COLD FRONT WILL BE SLOW
TO PUSH THRU EASTERN PA IN RESPONSE TO DIGGING UPPER TROF AXIS
STILL JUST WEST OF PA. AFTER A LULL IN THE PRECIP DURING LATE
AM...EXPECT SCT SHRA/TSRA TO DEVELOP IN UNSTABLE AIR MASS ALONG
AND EAST OF FRONT OVR THE SUSQ VALLEY. EASTERN AREAS ARE PAINTED
WITH A MARGINAL THREAT FOR SEVERE TOMORROW...WHICH SEEMS
REASONABLE DEPENDING ON THE EVENTUAL PROGRESS OF THE SURFACE
BOUNDARY. OTHERWISE THERE WILL BE SCATTERED SHOWERS AND A THREAT
FOR THUNDERSTORMS WITH THE BEST CHANCES FAVORING THE EASTERN HALF
OF THE FORECAST AREA.
AFTER A CLOUDY START TO THE DAY...EXPECT PTSUNNY SKIES
TUESDAY...AS EASTERN PA BREAKS INTO SW FLOW IN THE WARM SECTOR
AND WESTERLY FLOW/DRIER AIR WORKS INTO THE CENTRAL MTNS/ALLEGHENIES.
ENS MEAN 925TEMPS SUPPORT MAX TEMPS FROM THE MID 70S NW MTNS...TO
L/M80S OVR THE SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BEHIND TUESDAY/S FRONTAL PASSAGE...ANY LINGERING SHOWERS WILL
QUICKLY TAPER OFF AS TUESDAY NIGHT PROGRESSES. AN UPPER LEVEL
TROUGH WILL DEEPEN OVERHEAD AND COOLER TEMPERATURES WILL MOVE
INTO THE REGION FOR WEDNESDAY AND THURSDAY. BOTH THE GEFS AND THE
NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW NORMAL 850 MB
TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...NORTHWEST FLOW
ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS WEDNESDAY
AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON
THURSDAY...BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL
BECOME MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS
THE ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A
MORE WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SEVERAL AREAS OF SHOWERS AND THUNDERSTORMS AT 11 PM.
SOME ADJUSTMENT TO 03Z TAF PACKAGE.
EARLIER DISCUSSION BELOW.
LOW CLOUDS OVER MOST OF THE AREA.
FURTHER WEST...MORE IN THE WAY OF SHOWERS AND THUNDERSTORMS.
LOOKS LIKE THE NW...BFD AREA...WILL BE THE MAIN AREA FOR SHOWERS
AND STORMS. DYNAMICS AND DRY PUNCH SEEM TO BE SPLITTING THE
AREA OF SHOWERS AND STORMS. MAIN AREA ACROSS THE NW INTO NY
STATE...MOVING NE.
ANOTHER AREA ACROSS FAR SW PA...THIS AREA MOVING MORE TO THE
EAST AND SE.
STILL MORE SHOWERS AND STORMS OVER OH. RATHER STRONG DYNAMICS
FOR EARLY AUG...THUS WILL KEEP SHOWERS AND STORMS IN THE 00Z
TAF PACKAGE.
FOR TUE...AREAS OF EAST OF THE MOUNTAINS WILL HAVE THE BEST
CHANCE TO SEE VFR CONDITIONS...WHILE SPOTS LIKE BFD AND JST
MAY HOLD ONTO MVFR CIGS.
OUTLOOK...
WED...MOSTLY VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...HAGNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1054 PM EDT MON AUG 10 2015
.SYNOPSIS...
A FRONTAL SYSTEM OVER THE OHIO VALLEY WILL MOVE THROUGH THE
REGION OVERNIGHT AND EARLY TUESDAY. COOLER AND DRIER AIR WILL
FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL REBOUND LATE
THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE MID
MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATE EVENING RADAR MOSAIC SHOWING WIDESPREAD SHRA/TSRA ACROSS NW
PA IN ADVANCE OF APPROACHING UPPER TROF. 02Z SPC MESOANALYSIS
STILL INDICATING SOME MODEST CAPES OF ARND 500 J/KG ACROSS
WESTERN PA...WHERE THERE WAS SOME SUNSHINE EARLIER TODAY. FURTHER
EAST...MOIST SERLY FLOW YIELDING MARINE LYR STRATUS BUT SHOWERS
HAVE YET TO REACH MOST OF CENTRAL PA AS OF 03Z.
EXPECT SHRA TO OVERSPREAD THE REGION FROM WEST TO EAST OVERNIGHT...AS
UPPER TROF AND PRECEDING LL JET/PLUME OF ANOMALOUS PWATS OVERSPREAD
THE STATE. SPC HAD EARLIER PLACED THE ALLEGHENY PLATEAU IN A MRGL
RISK AREA FOR SVR WX THIS EVENING. HOWEVER...GIVEN DIMINISHING
CAPES AND NEARLY NON-EXISTENT DCAPES...BELIEVE THE THREAT OF SVR
WX IS LOW. GREATER RISK WILL BE POSSIBILITY OF ISOLD FLOODING
ACROSS THE NW MTNS...WHERE LINGERING INSTABILITY...COMBINED WITH
SURGING PWATS...COULD PRODUCE LOCALIZED EXCESSIVE RAINFALL. HPC
HAS OUTLINED OUR NW COUNTIES FOR POTENTIALLY HEAVY RAINS. SHORT
TERM GUIDANCE SHOWS A PRETTY QUICK PROGRESSION ACROSS THE STATE OF
THE LOW LEVEL JET AND AXIS OF DEEPEST MOISTURE. WILL HAVE TO WATCH
FOR THE POTENTIAL FOR TRAINING CONVECTION IN THE MOISTURE-RICH
AIR MASS. SPC SSEO AND LATEST HRRR TARGET THE NW MTNS FOR
LOCALIZED AMTS 3+ INCHES. HAVE MENTIONED SLIGHT RISK OF FLOODING
ACROSS THIS AREA IN THE HWO...BUT GIVEN RECENT DRYNESS...FEEL ODDS
OF TRUE FLASH FLOODING NOT HIGH ENOUGH FOR A WATCH ATTM.
STRONG FRONTAL PASSAGE...ANOMALOUS PWATS AND LATEST GEFS/SREF
OUTPUT ALL SUPPORT NEAR 100 PCT POPS OVERNIGHT ACROSS ALL OF
CENTRAL PA. BEST CHANCE WILL COME BEFORE MIDNIGHT ACROSS THE
NW COUNTIES AND AFTER MIDNIGHT ELSEWHERE. SHORT TERM GUIDANCE
TIMES THE LOW LEVEL JET EAST OF THE ENTIRE REGION BY
12Z...RESULTING IN THE STEADIEST RAIN EXITING OUR EASTERN COUNTIES
SHORTLY AFTER DAWN. LOWS IN THE MID 60S TO LOWER 70S WILL FEEL
RATHER TROPICAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ANOMALOUS LL JET/PWATS WILL HAVE SHIFTED EAST OF THE AREA WITH
LEAD SHORTWAVE BY EARLY TUESDAY...BRINGING AN END TO THE BULK OF
THE RAINFALL BY ARND DAWN. HOWEVER...SFC COLD FRONT WILL BE SLOW
TO PUSH THRU EASTERN PA IN RESPONSE TO DIGGING UPPER TROF AXIS
STILL JUST WEST OF PA. AFTER A LULL IN THE PRECIP DURING LATE
AM...EXPECT SCT SHRA/TSRA TO DEVELOP IN UNSTABLE AIR MASS ALONG
AND EAST OF FRONT OVR THE SUSQ VALLEY. EASTERN AREAS ARE PAINTED
WITH A MARGINAL THREAT FOR SEVERE TOMORROW...WHICH SEEMS
REASONABLE DEPENDING ON THE EVENTUAL PROGRESS OF THE SURFACE
BOUNDARY. OTHERWISE THERE WILL BE SCATTERED SHOWERS AND A THREAT
FOR THUNDERSTORMS WITH THE BEST CHANCES FAVORING THE EASTERN HALF
OF THE FORECAST AREA.
AFTER A CLOUDY START TO THE DAY...EXPECT PTSUNNY SKIES
TUESDAY...AS EASTERN PA BREAKS INTO SW FLOW IN THE WARM SECTOR
AND WESTERLY FLOW/DRIER AIR WORKS INTO THE CENTRAL MTNS/ALLEGHENIES.
ENS MEAN 925TEMPS SUPPORT MAX TEMPS FROM THE MID 70S NW MTNS...TO
L/M80S OVR THE SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BEHIND TUESDAY/S FRONTAL PASSAGE...ANY LINGERING SHOWERS WILL
QUICKLY TAPER OFF AS TUESDAY NIGHT PROGRESSES. AN UPPER LEVEL
TROUGH WILL DEEPEN OVERHEAD AND COOLER TEMPERATURES WILL MOVE
INTO THE REGION FOR WEDNESDAY AND THURSDAY. BOTH THE GEFS AND THE
NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW NORMAL 850 MB
TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...NORTHWEST FLOW
ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS WEDNESDAY
AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON
THURSDAY...BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL
BECOME MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS
THE ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A
MORE WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
LOW CLOUDS OVER MOST OF THE AREA.
FURTHER WEST...MORE IN THE WAY OF SHOWERS AND THUNDERSTORMS.
LOOKS LIKE THE NW...BFD AREA...WILL BE THE MAIN AREA FOR SHOWERS
AND STORMS. DYNAMICS AND DRY PUNCH SEEM TO BE SPLITTING THE
AREA OF SHOWERS AND STORMS. MAIN AREA ACROSS THE NW INTO NY
STATE...MOVING NE.
ANOTHER AREA ACROSS FAR SW PA...THIS AREA MOVING MORE TO THE
EAST AND SE.
STILL MORE SHOWERS AND STORMS OVER OH. RATHER STRONG DYNAMICS
FOR EARLY AUG...THUS WILL KEEP SHOWERS AND STORMS IN THE 00Z
TAF PACKAGE.
FOR TUE...AREAS OF EAST OF THE MOUNTAINS WILL HAVE THE BEST
CHANCE TO SEE VFR CONDITIONS...WHILE SPOTS LIKE BFD AND JST
MAY HOLD ONTO MVFR CIGS.
OUTLOOK...
WED...MOSTLY VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...HAGNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
818 PM EDT MON AUG 10 2015
.SYNOPSIS...
A FRONTAL SYSTEM OVER THE OHIO VALLEY WILL MOVE THROUGH THE
REGION OVERNIGHT AND EARLY TUESDAY. COOLER AND DRIER AIR WILL
FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL REBOUND LATE
THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE MID
MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
EVENING RADAR MOSAIC SHOWING WIDESPREAD SHRA/TSRA ACROSS NW PA IN
ADVANCE OF APPROACHING UPPER TROF. 23Z SPC MESOANALYSIS
INDICATING SOME MODEST CAPES OF ARND 1000 J/KG ACROSS WESTERN
PA...WHERE THERE WAS SOME SUNSHINE EARLIER TODAY. FURTHER
EAST...MOIST SERLY FLOW YIELDING MARINE LYR STRATUS BUT NO PRECIP
ACROSS MOST OF CENTRAL PA.
EXPECT SHRA TO OVERSPREAD THE REGION FROM WEST TO EAST OVERNIGHT...AS
UPPER TROF AND PRECEDING LL JET/PLUME OF ANOMALOUS PWATS OVERSPREAD
THE STATE. SPC HAD EARLIER PLACED THE ALLEGHENY PLATEAU IN A MRGL
RISK AREA FOR SVR WX THIS EVENING. HOWEVER...GIVEN DIMINISHING
CAPES AND NEARLY NON-EXISTENT DCAPES...BELIEVE THE THREAT OF SVR
WX IS LOW. GREATER RISK MAY BE ISOLD FLOODING ACROSS THE NW
MTNS...WHERE LINGERING INSTABILITY...COMBINED WITH SURGING
PWATS...COULD PRODUCE LOCALIZED EXCESSIVE RAINFALL. HPC HAS
OUTLINED OUR NORTHERN AREAS FOR POTENTIALLY HEAVY RAINS. SHORT
TERM GUIDANCE SHOWS A PRETTY QUICK PROGRESSION ACROSS THE STATE OF
THE LOW LEVEL JET AND AXIS OF DEEPEST MOISTURE. WILL HAVE TO WATCH
FOR THE POTENTIAL FOR TRAINING CONVECTION IN THE MOISTURE RICH
TROPICAL AIRMASS. SPC SSEO AND LATEST HRRR TARGET THE NW MTNS FOR
LOCALIZED AMTS 3+ INCHES. HAVE MENTIONED SLIGHT RISK OF FLOODING
ACROSS THIS AREA IN THE HWO...BUT GIVEN RECENT DRYNESS...FEEL ODDS
OF FLASH FLOODING NOT HIGH ENOUGH FOR A WATCH ATTM.
STRONG FRONTAL PASSAGE...ANOMALOUS PWATS AND LATEST GEFS/SREF
OUTPUT ALL SUPPORT NEAR 100 PCT POPS OVERNIGHT ACROSS ALL OF
CENTRAL PA. BEST CHANCE WILL COME BEFORE MIDNIGHT ACROSS THE
WESTERN COUNTIES AND AFTER MIDNIGHT ACROSS THE EASTERN COS. SHORT
TERM GUIDANCE TIMES THE LOW LEVEL JET EAST OF THE ENTIRE REGION BY
12Z...RESULTING IN THE STEADIEST RAIN EXITING OUR EASTERN COUNTIES
ARND DAWN. LOWS IN THE MID 60S TO LOWER 70S WILL FEEL RATHER
TROPICAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
ANOMALOUS LL JET/PWATS WILL HAVE SHIFTED EAST OF THE AREA WITH
LEAD SHORTWAVE BY EARLY TUESDAY...BRINGING AN END TO THE BULK OF
THE RAINFALL BY ARND DAWN. HOWEVER...SFC COLD FRONT WILL BE SLOW
TO PUSH THRU EASTERN PA IN RESPONSE TO DIGGING UPPER TROF AXIS
STILL JUST WEST OF PA. AFTER A LULL IN THE PRECIP DURING LATE
AM...EXPECT SCT SHRA/TSRA TO DEVELOP IN UNSTABLE AIR MASS ALONG
AND EAST OF FRONT OVR THE SUSQ VALLEY. EASTERN AREAS ARE PAINTED
WITH A MARGINAL THREAT FOR SEVERE TOMORROW...WHICH SEEMS
REASONABLE DEPENDING ON THE EVENTUAL PROGRESS OF THE SURFACE
BOUNDARY. OTHERWISE THERE WILL BE SCATTERED SHOWERS AND A THREAT
FOR THUNDERSTORMS WITH THE BEST CHANCES FAVORING THE EASTERN HALF
OF THE FORECAST AREA.
AFTER A CLOUDY START TO THE DAY...EXPECT PTSUNNY SKIES
TUESDAY...AS EASTERN PA BREAKS INTO SW FLOW IN THE WARM SECTOR
AND WESTERLY FLOW/DRIER AIR WORKS INTO THE CENTRAL MTNS/ALLEGHENIES.
ENS MEAN 925TEMPS SUPPORT MAX TEMPS FROM THE MID 70S NW MTNS...TO
L/M80S OVR THE SUSQ VALLEY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BEHIND TUESDAY/S FRONTAL PASSAGE...ANY LINGERING SHOWERS WILL
QUICKLY TAPER OFF AS TUESDAY NIGHT PROGRESSES. AN UPPER LEVEL
TROUGH WILL DEEPEN OVERHEAD AND COOLER TEMPERATURES WILL MOVE
INTO THE REGION FOR WEDNESDAY AND THURSDAY. BOTH THE GEFS AND THE
NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW NORMAL 850 MB
TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...NORTHWEST FLOW
ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS WEDNESDAY
AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON
THURSDAY...BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL
BECOME MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS
THE ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A
MORE WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
LOW CLOUDS OVER MOST OF THE AREA.
FURTHER WEST...MORE IN THE WAY OF SHOWERS AND THUNDERSTORMS.
LOOKS LIKE THE NW...BFD AREA...WILL BE THE MAIN AREA FOR SHOWERS
AND STORMS. DYNAMICS AND DRY PUNCH SEEM TO BE SPLITTING THE
AREA OF SHOWERS AND STORMS. MAIN AREA ACROSS THE NW INTO NY
STATE...MOVING NE.
ANOTHER AREA ACROSS FAR SW PA...THIS AREA MOVING MORE TO THE
EAST AND SE.
STILL MORE SHOWERS AND STORMS OVER OH. RATHER STRONG DYNAMICS
FOR EARLY AUG...THUS WILL KEEP SHOWERS AND STORMS IN THE 00Z
TAF PACKAGE.
FOR TUE...AREAS OF EAST OF THE MOUNTAINS WILL HAVE THE BEST
CHANCE TO SEE VFR CONDITIONS...WHILE SPOTS LIKE BFD AND JST
MAY HOLD ONTO MVFR CIGS.
OUTLOOK...
WED...MOSTLY VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE
LONG TERM...HAGNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
738 PM EDT MON AUG 10 2015
.SYNOPSIS...
A FRONTAL SYSTEM OVER THE OHIO VALLEY WILL MOVE THROUGH THE
REGION OVERNIGHT AND EARLY TUESDAY. COOLER AND DRIER AIR WILL
FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL REBOUND LATE
THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE MID
MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
EARLY EVENING RADAR MOSAIC SHOWING WIDESPREAD SHRA/TSRA ACROSS NW
PA IN ADVANCE OF APPROACHING UPPER TROF. SPC MESOANALYSIS
INDICATING SOME MODEST CAPES OF ARND 1000 J/KG ACROSS WESTERN
PA...WHERE THERE WAS SOME SUNSHINE EARLIER TODAY. FURTHER
EAST...MOIST SERLY FLOW YIELDING MARINE LYR STRATUS BUT NO PRECIP
ACROSS MOST OF CENTRAL PA.
EXPECT SHRA TO OVERSPREAD THE REGION FROM WEST TO EAST DURING THE
LATE EVENING HOURS...AS UPPER TROF AND PRECEDING LL JET/PLUME OF
ANOMALOUS PWATS OVERSPREAD THE STATE. SPC HAD PLACED THE
ALLEGHENY PLATEAU IN A MRGL RISK AREA FOR SVR WX THIS EVENING.
HOWEVER...GIVEN DIMINISHING CAPES AND NEARLY NON-EXISTENT
DCAPES...BELIEVE THE THREAT OF SVR WX IS LOW. GREATER RISK MAY
BE ISOLD FLOODING ACROSS THE NW MTNS...WHERE LINGERING
INSTABILITY...COMBINED WITH SURGING PWATS...COULD PRODUCE
LOCALIZED EXCESSIVE RAINFALL. HPC HAS OUTLINED OUR NORTHERN AREAS
FOR POTENTIALLY HEAVY RAINS. SHORT TERM GUIDANCE SHOWS A PRETTY
QUICK PROGRESSION ACROSS THE STATE OF THE LOW LEVEL JET AND AXIS
OF DEEPEST MOISTURE. WILL HAVE TO WATCH FOR THE POTENTIAL FOR
TRAINING CONVECTION IN THE MOISTURE RICH TROPICAL AIRMASS. SPC
SSEO AND LATEST HRRR TARGET THE NW MTNS FOR LOCALIZED AMTS 3+
INCHES. HAVE MENTIONED SLIGHT RISK OF FLOODING ACROSS THIS AREA IN
THE HWO...BUT GIVEN RECENT DRYNESS...FEEL ODDS OF FLASH FLOODING
NOT HIGH ENOUGH FOR A WATCH ATTM.
STRONG FRONTAL PASSAGE...ANOMALOUS PWATS AND LATEST GEFS/SREF
OUTPUT ALL SUPPORT NR 100 PCT POPS OVERNIGHT ACROSS ALL OF CENTRAL
PA. BEST CHANCE WILL COME BEFORE MIDNIGHT ACROSS THE WESTERN
COUNTIES AND AFTER MIDNIGHT ACROSS THE EASTERN COS. SHORT TERM
GUIDANCE TIMES THE LOW LEVEL JET EAST OF THE ENTIRE REGION BY
12Z...RESULTING IN THE STEADIEST RAIN EXITING OUR EASTERN COUNTIES
ARND DAWN. LOWS IN THE MID 60S TO LOWER 70S WILL FEEL RATHER
TROPICAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE MAIN AXIS OF MOISTURE AND LOW LEVEL FORCING WILL HAVE SHIFTED
EAST OF THE AREA BY EARLY TUESDAY...BUT SHORT RANGE OPERATIONAL
MODELS SUGGEST THE SURFACE FRONT WILL BE SLOW TO MOVE
THROUGH...AND BY AFTERNOON THEY DEVELOP A NOT INSIGNIFICANT
AMOUNT OF CAPE AS THE UPPER TROUGH DEEPENS OVERHEAD. EASTERN AREAS
ARE PAINTED WITH A MARGINAL THREAT FOR SEVERE TOMORROW...WHICH
SEEMS REASONABLE DEPENDING ON THE EVENTUAL PROGRESS OF THE SURFACE
BOUNDARY. OTHERWISE THERE WILL BE SCATTERED SHOWERS AND A THREAT
FOR THUNDERSTORMS WITH THE BEST CHANCES FAVORING THE EASTERN HALF
OF THE FORECAST AREA.
HIGHS FROM THE MID 70S TO MID 80S WILL BE SEVERAL DEGREES COOLER
THAN NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BEHIND TUESDAY/S FRONTAL PASSAGE...ANY LINGERING SHOWERS WILL
QUICKLY TAPER OFF AS TUESDAY NIGHT PROGRESSES. AN UPPER LEVEL
TROUGH WILL DEEPEN OVERHEAD AND COOLER TEMPERATURES WILL MOVE
INTO THE REGION FOR WEDNESDAY AND THURSDAY. BOTH THE GEFS AND THE
NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW NORMAL 850 MB
TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...NORTHWEST FLOW
ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS WEDNESDAY
AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON
THURSDAY...BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL
BECOME MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS
THE ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A
MORE WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
LOW CLOUDS OVER MOST OF THE AREA.
FURTHER WEST...MORE IN THE WAY OF SHOWERS AND THUNDERSTORMS.
LOOKS LIKE THE NW...BFD AREA...WILL BE THE MAIN AREA FOR SHOWERS
AND STORMS. DYNAMICS AND DRY PUNCH SEEM TO BE SPLITTING THE
AREA OF SHOWERS AND STORMS. MAIN AREA ACROSS THE NW INTO NY
STATE...MOVING NE.
ANOTHER AREA ACROSS FAR SW PA...THIS AREA MOVING MORE TO THE
EAST AND SE.
STILL MORE SHOWERS AND STORMS OVER OH. RATHER STRONG DYNAMICS
FOR EARLY AUG...THUS WILL KEEP SHOWERS AND STORMS IN THE 00Z
TAF PACKAGE.
FOR TUE...AREAS OF EAST OF THE MOUNTAINS WILL HAVE THE BEST
CHANCE TO SEE VFR CONDITIONS...WHILE SPOTS LIKE BFD AND JST
MAY HOLD ONTO MVFR CIGS.
OUTLOOK...
WED...MOSTLY VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...HAGNER
AVIATION...MARTIN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
102 PM CDT SUN AUG 9 2015
.UPDATE...
ISSUED AT 1247 PM CDT SUN AUG 9 2015
STRATUS LIKELY HAVING AN AFFECT ON THE AREA SO FAR AND THIS IS
SEEN WITH THE LATEST HRRR OUTPUT. WHILE TEMPERATURES ARE IN THE
UPPER 70S TO NEAR 80 IN MOST LOCATIONS THE HRRR RAISES
TEMPERATURES INTO THE MID 80S ALONG HIGHWAY 14 BY 18Z WHICH SEEMS
UNLIKELY. THE HRRR REALLY CRANKS OUT STRONG TO SEVERE
THUNDERSTORMS IN THE NORTHERN CWA BETWEEN 18Z-21Z BECAUSE OF THIS
HEATING. SO THIS SEEMS VERY DOUBTFUL BUT THERE IS AN OUTFLOW ALONG
HIGHWAY 14 SO WILL KEEP AN EYE. ALSO OF CONCERN ARE THE VERY LOW
LFC LEVELS WHICH MIGHT SUPPORT BRIEF SPIN UPS AND POSSIBLE
TORNADOES IF A STRONG THUNDERSTORM CAN DEVELOP. AT THIS TIME THE
MOST LIKELY LOCATION FOR DEVELOPMENT STILL SEEMS LIKE ALONG AND
WEST OF THE JAMES RIVER VALLEY...ESPECIALLY SOUTH CENTRAL SD
NEAREST THE WEAK SURFACE LOW. LATEST ANALYSIS HAS ABOUT 40 KNOTS
OF DEEP LAYER SHEAR ACROSS THE AREA AND ABOUT 2000 J/KG CAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 408 AM CDT SUN AUG 9 2015
CONVECTION AND ASSOCIATED SEVERE THREAT ARE MAIN FOCUS FOR TODAY.
MORNING HOURS SHOULD BE RATHER BENIGN...WITH CHANCE FOR NON-SEVERE
ACTIVITY DRIFTING INTO OUR FAR WEST OUT OF CENTRAL SD. MAIN FOCUS
WILL BE ON WELL-DEFINED UPPER WAVE CURRENTLY IN CENTRAL MONTANA AS
IT MOVES INTO THE DAKOTAS. ASSOCIATED SURFACE LOW WILL MOVE INTO
SOUTH CENTRAL SD BY MIDDAY/EARLY AFTERNOON. EVENTUAL TRACK OF THE
LOW WILL LIKELY BE DRIVEN BY CONVECTION...BUT CURRENTLY LOOKS TO
TRACK EAST-SOUTHEAST THROUGH THE MISSOURI RIVER VALLEY THROUGH THE
AFTERNOON/EARLY EVENING. FORECAST SOUNDINGS SHOW MINIMAL CAP...SO
SHOULD NOT BE DIFFICULT TO GET STORMS GOING ACROSS OUR WEST BY THE
EARLY-MID AFTERNOON. WITH PROXIMITY TO SURFACE LOW AND ASSOCIATED
WARM FRONT...LOW LEVEL HELICITY SHOULD BE LOCALLY ENHANCED AND
PRESENT A RISK OF TORNADOES. THINK THIS WILL BE FOCUSED IN AREAS
WEST OF THE JAMES RIVER VALLEY DURING THE MID-LATE AFTERNOON.
PRIMARY QUESTION AT THIS POINT IS EXACTLY WHERE THE SURFACE LOW
AND ATTENDANT BOUNDARIES WILL BE LOCATED...AS MODELS VARY FROM
NORTH CENTRAL NEBRASKA TO NEAR I-90 CORRIDOR. HAVE LEANED TOWARD
THE MORE NORTHERN SOLUTION FOR NOW...BUT WILL HAVE TO BE MONITORED
THROUGH THE DAY.
ALONG WITH THREAT OF ISOLATED TORNADOES WILL COME POTENTIAL FOR
LARGE HAIL AND DAMAGING WINDS. HAIL THREAT IN PARTICULAR WILL
EXTEND FARTHER NORTH INTO THE DEEPER EASTERLY LOW LEVEL FLOW...AND
CONTINUE AS THE STORMS TRACK EAST-SOUTHEAST ACROSS THE REGION
THROUGH THE EVENING...WITH SEVERE THREAT WANING AFTER MIDNIGHT AS
THE STORMS CONTINUE EAST AND AIRMASS BECOMES LESS UNSTABLE. WITH
MODELS INDICATING PRECIPITABLE WATER VALUES NEAR 1.5-2 INCHES...
COULD ALSO SEE LOCALLY HEAVY RAIN. HOWEVER EXPECT STORMS TO BE
SOMEWHAT PROGRESSIVE SO FLASH FLOODING THREAT SHOULD BE MINIMIZED
OUTSIDE ISOLATED URBAN LOCATIONS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 408 AM CDT SUN AUG 9 2015
SHOWERS WILL EXIT THE SOUTHEAST PART OF THE AREA BY EARLY MONDAY
AFTERNOON AS THE DRY AIR PUSHES IN BEHIND THE COLD FRONT. THIS LEADS
INTO AN OTHERWISE DRY MONDAY THROUGH FRIDAY PERIOD AS THE DIGGING
TROUGH TO THE EAST AND THE PERSISTENT MONSTER RIDGE TO THE SOUTHWEST
PRODUCE A DRY FLOW. AS THIS RIDGE BUILDS SLOWLY TOWARD THE AREA
DURING THE WEEK...TEMPERATURES WILL WARM GRADUALLY FROM NEAR TO JUST
BELOW NORMAL TO ABOVE NORMAL...BUT THE WARMING PATTERN WILL BE
UNFAVORABLE TO PROVIDE THERMAL LIFT FOR STORMS...WHICH MAY BE MOOT
SINCE THE SLOWNESS OF ANY MOISTURE INCREASE IN THIS PATTERN WILL
ALSO PUT THE CLAMPS ON ANY STORM THREAT.
BY SATURDAY THE APPROACH OF A FRONT AND UPPER WAVE FROM THE
WEST/NORTHWEST MAY ALLOW A THREAT OF STORMS TO BEGIN FROM THAT
SIDE OF THE AREA.
THE GRADUAL NATURE OF THE RIDGE BUILDING AND WARMING SHOULD KEEP THE
WARMING TO NO WORSE THAN THE UPPER 80S TO LOW 90S FOR HIGHS BY THE
END OF THE WEEK. SHOULD THE RIDGE BUILD IN ON THE STRONGER
SIDE...WE MAY HAVE TO BUMP UP THOSE HIGHS LATER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1240 PM CDT SUN AUG 9 2015
OCCASIONAL MVFR CEILINGS THROUGH THE AFTERNOON THEN THUNDERSTORMS
BECOME THE FOCUS AFTER ABOUT 20Z. A FEW OF THESE STORMS WILL BE
STRONG TO SEVERE. THE MAIN THREAT FOR MVFR CEILINGS AND
THUNDERSTORMS WILL BE BEFORE ABOUT 5Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...08
SHORT TERM...JH
LONG TERM...
AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
944 PM CDT MON AUG 10 2015
.UPDATE...
UPDATED THE ZONE FORECASTS AND GRIDS FOR TONIGHT. LEFT IN A 20
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS...ALTHOUGH THE ACTUAL
POP MAY BE LESS THAN THAT. A FEW SHOWERS AND THUNDERSTORMS REMAIN
UPSTREAM OVER SOUTHEASTERN MO AND SOUTHERN IL. THE HRRR CONTINUES
TO SHOW THE POSSIBILITY OF A FEW SHOWERS AND THUNDERSTORMS
TONIGHT IN ASSOCIATION WITH WEAK UPPER LEVEL DISTURBANCES. LOWERED
THE MINIMUM TEMPERATURES SOME IN MOST LOCATIONS BASED ON CURRENT
TEMPERATURES. ALSO INCLUDED AREAS OF FOG AS ANY DRIER AIR AT THE
LOWER LEVELS WILL BE SLOW IN MOVING INTO THE REGION.
JCL
&&
.DISCUSSION... /ISSUED 549 PM CDT MON AUG 10 2015/
UPDATE...
UPDATED THE ZONE FORECASTS AND GRIDS TO ADJUST THE POPS TONIGHT
BASED ON THE LATEST MODELS AND CURRENT CONDITIONS. INCLUDED
CHANCE POPS FROM EAST CENTRAL AR TO MUCH OF NORTH MS WHERE THE
INSTABILITY IS GREATEST AND IS AHEAD OF A WEAK SURFACE BOUNDARY.
ELSEWHERE INCLUDED SLIGHT CHANCE POPS FOR THIS EVENING. ALSO
ADJUSTED THE SKY COVER GRIDS FOR TONIGHT...INDICATING PARTLY
CLOUDY SKIES IN THE ZONE FORECASTS.
JCL
DISCUSSION... /ISSUED 341 PM CDT MON AUG 10 2015/
A SHORTWAVE UPSTREAM ACROSS THE MIDDLE MISSISSIPPI VALLEY WILL
CONTINUE TO PUSH SOUTHEAST INTO THE SOUTHERN OHIO AND TENNESSEE
VALLEY TONIGHT. THIS WILL HELP TO ADVANCE A COLD FRONT SOUTH
ACROSS THE REGION OVERNIGHT. THE BEST FORCING ASSOCIATED WITH THE
SHORTWAVE SHOULD BE DIRECTED TO THE EAST OF OUR REGION WITH
EASTERN AREAS HAVING THE GREATEST POTENTIAL FOR CONVECTION
OVERNIGHT. EVEN IN THESE AREAS...SCATTERED COVERAGE AT BEST CAN BE
EXPECTED. OTHERWISE...FURTHER WEST...ISOLATED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AS THE FRONT MOVES THROUGH. AHEAD
OF THE FRONT THIS EVENING...HOT AND HUMID CONDITIONS IN NORTH
MISSISSIPPI WILL SUPPORT A FEW MORE HOURS OF HEAT INDEX VALUES
GREATER THAN 105 DEGREES. THE HEAT ADVISORY WILL CONTINUE IN THESE
LOCATIONS THROUGH 8 PM CDT.
THE COLD FRONT SHOULD EXIT SOUTHERN SECTIONS ON TUESDAY MORNING
WITH LINGERING SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS. A
DRIER AIRMASS WILL BEGIN TO FILTER INTO THE REGION BY TUESDAY
AFTERNOON BRINGING AN END TO CONVECTIVE CHANCES AND BEGIN A SLOW
FALL OF SURFACE DEWPOINTS FROM NORTH TO SOUTH.
HIGH PRESSURE BUILDING INTO THE MID SOUTH WILL REMAIN IN PLACE
THROUGH MUCH OF THE REMAINDER OF THE WEEK. DRY WEATHER ALONG WITH
COOLER TEMPERATURES AND LOWER HUMIDITY VALUES CAN BE EXPECTED.
AN INVERTED SURFACE TROUGH AND AN INFLUX OF TROPICAL MOISTURE
SHOULD MOVE BACK INTO THE FORECAST AREA FROM THE EAST BY NEXT
WEEKEND. THIS WILL LIKELY BRING INCREASED HUMIDITY LEVELS ALONG
WITH INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS.
TEMPERATURES SHOULD ALSO RETURN TO NEAR SEASONAL VALUES FOR MID
AUGUST.
JLH
&&
.AVIATION...
00Z TAF CYCLE
VFR CONDITIONS WILL CONTINUE FOR MUCH OF THE FORECAST PERIOD. A
FEW THUNDERSTORMS HAVE DEVELOPED OVER PORTIONS OF NORTHEAST
MISSISSIPPI AND THIS ACTIVITY WILL MOVE OUT OF THE FORECAST AREA
THIS EVENING. SOME AREAS OF FOG ARE EXPECTED OVERNIGHT WITH DENSE
FOG POSSIBLE IN THE KMKL AREA. WINDS WILL BE MAINLY FROM THE NORTH
AT AROUND 5 KNOTS TONIGHT AND THEN INCREASE TO AROUND 10 KNOTS
TUESDAY.
ARS
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AMARILLO TX
431 PM CDT SUN AUG 9 2015
.DISCUSSION...
A WEAK BOUNDARY SLOWLY SAGGING SOUTH SHOULD BE THE FOCUS FOR STORM
DEVELOPMENT THIS AFTERNOON AND INTO THE OVERNIGHT HOURS. STORMS COULD
ALSO DEVELOP ALONG AN AREA OF CONVERGENCE FROM CANADIAN TO BUSHLAND.
THIS DEVELOPMENT IS SHOWN IN THE HRRR OUTPUT, BUT MORNING CLOUD
COVER HAS SLOWED THE WARMING IN THESE AREAS WHICH MAY DELAY THE
INITIATION TO LATER IN THIS EVENING. ANY STORMS THAT DO DEVELOP ALONG
THIS CONVERGENCE AREA SHOULD MOVE OFF INTO WESTERN OKLAHOMA LATER
THIS EVENING AS A WEAK SHORTWAVE SEEN IN WATER VAPOR IMAGERY OVER
SOUTHERN NEW MEXICO ROUND THE RIDGE. THIS SHORTWAVE SHOULD ALSO HELP
CONVECTION TO DEVELOP ALONG THE SOUTHWARD MOVING BOUNDARY. BOTH
ROUNDS OF STORMS SHOULD HAVE THE POTENTIAL TO BECOME STRONG TO
MARGINALLY SEVERE WITH AROUND 2000 J/KG AND DEEP LAYER SHEAR AROUND
20-25KT. HEAVY RAIN WILL ALSO BE OF CONCERN WITH ANY STORM THAT
DEVELOPS. PWAT VALUES OVERNIGHT CONTINUE TO HOVER RIGHT AROUND THE
+2SD FOR THIS TIME OF YEAR. WHILE AVERAGE FORECAST AMOUNTS RANGE FROM
A QUARTER OF AN INCH UP TO THREE QUARTERS OF AN INCH, THERE REMAINS
AS RISK FOR LOCALIZED AMOUNTS UP TO 1.5 INCHES WITH THE STORMS
THROUGH MONDAY MORNING.
A FEW LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE FOR THE
MONDAY MORNING COMMUTE BUT RAINFALL AMOUNTS FROM THESE STORMS SHOULD
BE LESS THAN THE OVERNIGHT STORMS. AFTER A BRIEF LULL AROUND MIDDAY
THE NEXT ROUND OF STORMS IS EXPECTED TO DEVELOP AS THE UPPER LEVEL
FLOW BECOMES MORE NORTHWESTERLY. THE WIND SHIFT, WHILE MOSTLY SOUTH
OF THE PANHANDLES, SHOULD STILL BE POSITIONED TO ALLOW SIZABLE
ISENTROPIC UPGLIDE MONDAY AFTERNOON INTO TUESDAY. THE THOUGHT OF A
FLASH FLOOD WATCH FOR MONDAY AFTERNOON INTO TUESDAY MORNING
CONTINUES TO COME UP BUT THERE HAS BEEN SIGNIFICANT DISCREPANCIES
BETWEEN MODEL RUNS. YESTERDAY THE GFS SHOWED UP TO 3 INCHES FOR THE
NORTHWEST AND SHOWS AROUND AN INCH STORM TOTAL (JUST LIKE THE ECMWF
SHOWED YESTERDAY). TODAY IT`S THE MORNING NAM WHICH SHOWS 2-4 INCHES
ACROSS THE WESTERN OKLAHOMA PANHANDLE WITH EVEN HIGHER AMOUNTS IN
SOUTHEASTERN COLORADO (ALTHOUGH THE 18Z RUN HAS ALREADY BEGUN TO
BACK OFF ON THESE AMOUNTS). AS A RESULT OF THESE DISCREPANCIES WILL
HOLD OFF ON ISSUING A WATCH UNTIL THE IMPACTED AREA CAN BE NARROWED
DOWN. RAINFALL AMOUNTS WITH THIS ROUND ARE EXPECTED TO BE HIGHEST
ACROSS THE NORTHERN TEXAS AND OKLAHOMA PANHANDLES AND RANGE BETWEEN
THREE QUARTERS OF AN INCH UP TO 1.5 INCHES WITH LOCALLY HIGHER
AMOUNTS POSSIBLE. AMOUNTS ACROSS THE SOUTHERN TEXAS PANHANDLE LOOK TO
RANGE BETWEEN A QUARTER OF AN INCH UP TO THREE QUARTERS OF AN INCH
WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
WEDNESDAY THROUGH THE REST OF THE WEEK...THE RIDGE CONTINUES TO MOVE
INTO THE CONTINENTAL DIVIDE TO KEEP THE PANHANDLES WITH A NORTH-
NORTHWEST FLOW REGIME ALOFT. THIS WILL KEEP OFF AN ON RAIN CHANCES IN
THE FORECAST AND SLIGHTLY COOLER TEMPERATURES THROUGH THE END OF THE
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMARILLO TX 70 88 68 86 68 / 50 30 40 30 20
BEAVER OK 70 90 70 86 67 / 50 40 50 30 20
BOISE CITY OK 65 86 65 80 64 / 40 50 70 40 20
BORGER TX 73 90 71 86 70 / 50 40 50 30 20
BOYS RANCH TX 70 90 70 86 67 / 40 50 50 30 20
CANYON TX 69 89 70 87 67 / 40 30 30 30 10
CLARENDON TX 73 92 71 88 70 / 30 30 20 20 10
DALHART TX 68 87 68 83 65 / 40 50 70 30 20
GUYMON OK 69 90 68 83 67 / 40 40 70 40 20
HEREFORD TX 69 90 69 87 67 / 30 40 30 30 10
LIPSCOMB TX 72 92 71 87 68 / 60 30 40 30 20
PAMPA TX 70 88 69 84 68 / 50 30 50 30 20
SHAMROCK TX 71 94 71 89 69 / 40 30 30 30 20
WELLINGTON TX 71 96 71 91 70 / 30 20 20 20 10
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
2/14
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1137 PM CDT SAT AUG 8 2015
.AVIATION...
AN OUTFLOW BOUNDARY...OR POSSIBLY TWO...WILL MOVE THROUGH KPVW AND
KLBB EARLY THIS MORNING AND BRING A SHIFT IN WIND
DIRECTION...HOWEVER WIND SPEEDS ARE EXPECTED TO REMAIN AROUND 12
KTS OR LESS. THERE IS A REMOTE CHANCE THAT A WEAK T-STORM COULD
APPROACH EITHER TERMINAL BETWEEN ABOUT 06 AND 10 UTC...BUT
CONFIDENCE NOT SUFFICIENT TO INCLUDE IN THE TAF. OTHERWISE...VFR
CONDITIONS WITH SOUTHERLY WINDS ARE EXPECTED AT ALL TERMINALS
WITH PERHAPS A LOW THREAT OF T-STORMS FOR KLBB AND KPVW AGAIN
SUNDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 650 PM CDT SAT AUG 8 2015/
AVIATION...
THE MAIN AVIATION CONCERN IS THE POTENTIAL FOR ISOLATED HIGH-BASED
T-STORM ACTIVITY TO APPROACH KLBB AND KPVW FROM THE WEST THIS
EVENING. THE MAIN THREATS FROM THIS ACTIVITY WILL BE
STRONG...ERRATIC WIND GUSTS AND LIGHTNING. CONFIDENCE IS TOO LOW
AT THIS TIME TO INCLUDE A TEMPO GROUP IN THE TAFS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED WITH PERHAPS A LOW THREAT OF T-STORMS
AGAIN VERY LATE IN THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 625 PM CDT SAT AUG 8 2015/
UPDATE...
SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS EAST-CENTRAL NEW
MEXICO AND APPEAR POISED TO AFFECT THE FAR SOUTHWEST TEXAS
PANHANDLE AND PERHAPS THE EXTREME NORTHWESTERN SOUTH PLAINS.
GIVEN THIS WE HAVE INCREASED POPS CONSIDERABLY FOR OUR FAR
NORTHWESTERN ZONES THIS EVENING. THE REMAINDER OF THE FORECAST
REMAINS IN GOOD SHAPE AND NO OTHER ADJUSTMENTS WERE MADE ATTM.
PREV DISCUSSION... /ISSUED 234 PM CDT SAT AUG 8 2015/
SHORT TERM...
BIGGEST CHANGE FROM EARLIER FORECASTS WAS TO EXPAND ISOLATED STORM
MENTION EASTWARD ACROSS MUCH OF THE CAPROCK THIS EVENING. EARLY
AFTERNOON ANALYSIS INDICATES A FAVORABLE COLLOCATION OF SURFACE
TROUGHING AND STEEP MID-LEVEL LAPSE RATES JUST WEST OF THE TX-NM
BORDER. SURFACE DEWPOINTS AREA WIDE ARE RUNNING 5-15 DEGS HIGHER
THAN THIS TIME YESTERDAY AND ARE YIELDING 1000-2000 J/KG OF MLCAPE
ACROSS THE SOUTH PLAINS. ALREADY NOTICING SOME CU BUILDING SOUTH OF
CVS AT 19Z AS DEEP MIXING THERE CATAPULTS PARCELS TO THEIR CCL
LEVELS. THIS THEME SHOULD EXPAND SOUTHWARD ALONG THE SURFACE TROUGH
WITH A FEW STORMS LIKELY TO BE DOTTING OUR WESTERN ZONES BY LATE
AFTERNOON. AS THESE PULSE-TYPE CELLS MOVE SLOWLY NORTHEAST...OUTFLOW
REGENERATION OF NEW STORMS SEEMS PLAUSIBLE THROUGH EARLY EVENING IN
LIGHT OF MEAGER CIN. HRRR HAS BEEN QUITE ADAMANT IN BLOSSOMING A
LARGER COVERAGE OF STORMS BEFORE SUNSET...BUT WITH NO DISCERNIBLE
BACKGROUND SUPPORT AVAILABLE IT SEEMS A SAFER BET TO KEEP PRECIP
MENTION ON THE ISOLATED SIDE. A DECENT NOCTURNAL LLJ MAY KEEP SOME
SEMBLANCE OF THESE EARLIER STORMS INTACT AFTER MIDNIGHT.
SUNDAY WILL SEE A TALL AND CLOSED ANTICYCLONE RETROGRADE TO CENTRAL
TEXAS COMPLETE WITH RISING HEIGHTS AND THICKNESSES LOCALLY. THIS
PROCESS WILL HELP REORIENT THE SURFACE TROUGH FROM N-S TO NE-SW
ACROSS THE WRN TX PANHANDLE INTO ERN NM. BEST STORM CHANCES SHOULD
PLAY OUT IN THE NRN PANHANDLE NEAR THE INTERSECTION OF THE TROUGH
AND A STALLING FRONT...BUT DEEP MIXING AND WEAK CAPE IN OUR NW
COUNTIES COULD SPUR A FEW LATE AFTERNOON STORMS. OTHERWISE...MAX
TEMPS LOOK TO SHAKE OUT A DEGREE OR TWO WARMER THAN TODAY.
LONG TERM...
UPPER LEVEL RIDGE IS EXPECTED TO BE CENTERED OVER EAST
TEXAS SUNDAY EVENING WHILST VIGOROUS UPPER LEVEL LOW SLIDES DOWN THE
COAST OF BRITISH COLUMBIA. THE STRENGTH OF THE RIDGE IS EXPECTED TO
BE SUFFICIENTLY STRONG TO HOLD THE LOW OFF THE PACIFIC NORTHWEST
COAST AT LEAST THROUGH 120 HOURS BEFORE IT EJECTS NEWRD INTO SRN
CANADA. TO OUR NORTH A SHORTWAVE PASSES EARLY MONDAY ACROSS THE
CENTRAL PLAINS FOLLOWED BY ANOTHER SURGE OF ENERGY ROTATING ABOUT
HUDSON BAY LOW EARLY TUESDAY BEFORE RIDGE BUILDS STRONGLY ALL THE
WAY UP TO NUNAVUT. AS THE HIGH SLOWLY RETROGRADES...FLOW WILL
BECOME MORE NORTHERLY TO NORTHEASTERLY WITH TIME AND THIS SHOULD
HELP COOL TEMPS A BIT IN THE LATTER EXTENDED.
BEST RAIN CHANCES DURING THE EXTENDED WILL EXIST FROM SUNDAY EVENING
INTO TUESDAY AS FRONTAL BOUNDARY SAGS INTO THE REGION. HIGHEST
POTENTIAL WILL EXIST NORTH AND WEST. TRENDS HAVE BEEN EDGING THE
BOUNDARY FURTHER SOUTH WITH EACH RUN AND THIS CERTAINLY FITS THE
PATTERN THIS SUMMER. THINGS LOOK TO DRY OUT ON WEDNESDAY WITH
PERHAPS A FEW SCT SHOWERS NEAR THE ESCARPMENT BUT OVERALL TRENDING
DRIER FOR THE REMAINDER OF THE EXTENDED.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 64 94 67 90 / 50 20 20 30
TULIA 66 95 68 92 / 20 0 20 30
PLAINVIEW 65 95 70 93 / 20 0 10 20
LEVELLAND 68 96 70 95 / 20 0 10 20
LUBBOCK 71 98 72 96 / 20 0 10 10
DENVER CITY 68 98 69 96 / 20 0 10 10
BROWNFIELD 68 98 70 96 / 20 0 10 10
CHILDRESS 73 102 75 99 / 0 0 10 20
SPUR 70 101 72 99 / 0 0 10 0
ASPERMONT 75 104 75 103 / 0 0 0 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33/23/
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1259 AM EDT SUN AUG 9 2015
.SYNOPSIS...
WEAK HIGH PRESSURE WILL MOVE OVERHEAD SUNDAY. RAIN CHANCES WILL
INCREASE MONDAY INTO MONDAY NIGHT AS A COMPLEX FRONTAL SYSTEM
MOVES INTO THE REGION. A COLD FRONT WILL SWEEP ACROSS THE AREA
TUESDAY FOLLOWED BY HIGH PRESSURE THAT BRING ANOTHER ROUND OF
DRIER AND COOLER WEATHER FOR MID AND LATE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 940 PM EDT SATURDAY...
PERSISTENT AREA OF SHOWERS CONTINUE TO IMPACT CENTRAL PART OF FCST
AREA FROM NEAR WV/VA BORDER INTO NEW RIVER VALLEY AND MAY REACH
TO NEAR BLUE RIDGE OF FAR SW VA BY 11PM BEFORE LIKELY DISSIPATING
BY AROUND MIDNIGHT. LATEST HRRR RUN ACTUALLY NOW HAS PRETTY GOOD
HANDLE ON CURRENT RADAR DEPICTION AND DOES SHOW STEADY
WEAKENING...EXCEPT FOR AROUND THE BLUE RIDGE OF FAR SW VA AND NW
NC WELL AFTER MIDNIGHT. HAVE ONCE AGAIN EXTENDED SOME SLIGHT CHC
POPS A LITTLE LATER INTO THE OVERNIGHT BUT STILL REMOVING
COMPLETELY BY 07Z AS STILL FEEL THAT WITH NEGLIBLE INSTABILITY BY
THAT TIME THAT NAM AND SOME OTHER HI RES MODELS ARE OVERDOING IT
PERHAPS DUE TO A WEAK S/WV IN NW FLOW COMING FROM OHIO VALLEY THAT
NOT SURE IS EVEN REALLY THERE. REDUCED SKY COVER ON THE SW AND SE
FRINGES BUT LEFT MOSTLY CLOUDY IN THE MIDDLE OVERNIGHT WITH THE
WEAK LOW LEVEL CONVERGENCE NEAR BLUE RIDGE. KEPT PATCHY FOG BUT A
FORMING A BIT LATER. OTHERWISE TEMPS OVERNIGHT LOOK GOOD SO NO
OTHER CHANGES.
PREV DISCUSSION AS OF 655 PM EDT SATURDAY...
ISOLATED SHOWERS CONTINUE TO SLOWLY DRIFT SOUTHEASTWARD ACROSS
ALLEGHENY HIGHLANDS INTO SOUTHERN SHENANDOAH VALLEY AND IN A FEW
OTHER SPOTS ACROSS SOUTHEAST WV AND MTNS OF SW VA AND FAR NW NC.
HAVE NOT OBSERVED ANY IN-CLOUD OR CLOUD-TO-GROUND LIGHTNING SO
FAR THIS AFT AND EARLY EVE. WHILE HI RES MODELS LIKE HRRR...AS
WELL AS 18Z NAM...TRY TO LINGER THESE UNTIL MIDNIGHT OR EVEN
BEYOND...DO NOT SEE SIGNIFICANT MECHANISM ONCE WE LOSE HEATING TO
KEEP THESE GOING...OTHER THAN SOME WEAK LOW-LEVEL CONVERGENCE NEAR
THE BLUE RIDGE WHICH MAY BE ENOUGH TO EXTEND A FEW MORE HOURS PAST
SUNSET BUT NOT ALL THAT CONFIDENT. INSTABILITY REMAINS QUITE LOW
AND CONFINED MAINLY TO THE WESTERN SLOPES SO AS THESE MOVE FARTHER
EAST THEY SHOULD SLOWLY DIE. NEVERTHELESS...HAVE STRETCHED THE
15-20 POP AREA JUST EAST OF THE BLUE RIDGE AND EXTENDED IN TIME
UNTIL ABOUT MIDNIGHT PER THESE MODELS...BUT NOT READY TO GO BEYOND
THAT YET. OTHERWISE OTHER THAN A FEW NUDGES TO TEMPS, DEW PTS AND
SKY COVER PER LATEST OBSERVATIONS...NOT OTHER CHANGES THROUGH THE
OVERNIGHT.
PREV DISCUSSION AS OF 222 PM EDT SATURDAY...
LOCAL WRF/HRRR ISOLATED TO WIDELY SCATTERED SHOWERS FROM THE
ALLEGHANY HIGHLANDS WV/VA SOUTHWARD TO THE VA FOOTHILLS THROUGH
EARLY EVENING BEFORE DISSIPATING. MAY SEE A FEW SHOWER SOUTHWEST
TOWARD THE MTNS OF NC/FAR SW VA AS WELL CLOSER TO HIGHER THETA-E
AIR. STILL NOT MUCH OUT THERE...AND EVEN THREAT OF THUNDERSTORMS IS
LOW WITH MARGINAL CAPE.
OVERNIGHT HAVE INCREASED CLOUD COVER AS THINK WE WILL SEE AN
INVERSION SET UP WITH LITTLE TO NIL MIXING AND ANY LINGERING
STRATOCU/CU WILL SPREAD OUT THROUGH THE NIGHT. NOT COMPLETELY CLOUDY
SO NOT OUT OF THE QUESTION TO SEE FOG FORM IN THE VALLEYS OVERNIGHT.
LOWS WILL STAY CLOSE TO SEASONAL NORMS OF LOW TO MID 60S.
SUNDAY...THE 5H RIDGE AND HEIGHTS BUILD A LITTLE TO THE NORTHEAST.
WEAK UPPER SUPPORT TO COMBINE WITH LOW LEVEL THETA-E RIDGE OVER THE
BLUE RIDGE TO FORM A FEW SHOWERS/ISOLATED STORMS IN THE AFTERNOON.
SKIES WILL BE MOSTLY SUNNY OVER THE PIEDMONT...TO PARTLY
SUNNY...BECOMING MOSTLY CLOUDY WEST. HIGHS TO RANGE FROM THE UPPER
70S TO LOWER 80S IN THE MOUNTAINS...TO MID TO UPPER 80S EAST.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 330 PM SATURDAY...
SIMILAR TO PAST FEW EVENINGS...ONGOING SHOWERS AND THUNDERSTORMS
SUNDAY WILL DIMINISH BEFORE MIDNIGHT.
FORCING WILL BE A COMBINATION OF WARM AIR ADVECTION AND OVERRUNNING
ACROSS THE WARM FRONT AND LIFT AHEAD OF THE COLD FRONT MONDAY NIGHT
AND TUESDAY MORNING. THE MOST UNSTABLE AIR WILL BE JUST ALONG THE
FRONT SO STRONG THUNDERSTORMS ARE STILL POSSIBLE IN THE EASTERN
COUNTY WARNING AREA TUESDAY AFTERNOON BUT THIS IS HEAVILY DEPENDENT
ON THE SPEED OF THE FRONT. DEEP MOISTURE WITH PRECIPITABLE WATER
VALUES JUST UNDER 2.0 INCHES WILL FILL IN ACROSS THE FORECAST AREA
ON SUNDAY NIGHT.
USED WARMER GUIDANCE FOR MINIMUM TEMPERATURES ON SUNDAY NIGHT SINCE
DEW POINTS WILL BE INCREASING. CLOUDS AND PRECIPITATION WILL LIMIT
TEMPERATURE RISE ON MONDAY. HAVE TRIMMED BACK MAXIMUM TEMPERATURES.
FORECAST AREA WILL STILL BE AHEAD OF THE COLD FRONT ON MONDAY NIGHT
SO TEMPERATURES WILL REMAIN MILD. MAV GUIDANCE LOOKS REASONABLE FOR
MONDAY NIGHT LOWS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 200 PM SATURDAY...
CLOSED 500 MB LOW OVER SOUTHEAST CANADA BY TUESDAY NIGHT AND A DEEP
TROF REMAINS OVER THE EAST THROUGH THURSDAY. BY FRIDAY THERE IS
STILL TROUGHING OVER THE EASTERN UNITED STATES BUT THE UPPER LOW HAS
RETREATED NORTH AND HEIGHTS ARE HIGHER OVER THE MID ATLANTIC STATES.
THERE MAY BE ENOUGH VORTICITY ROTATING AROUND THE UPPER LOW ON
WEDNESDAY TO PROVIDE SOME LIFT TO THE MOUNTAINS IN SOUTHEAST WEST
VIRGINIA.
SURFACE HIGH PRESSURE OVER THE MISSISSIPPI VALLEY ON TUESDAY NIGHT
WILL GRADUALLY BUILD EAST. BY FRIDAY MORNING AT LEAST A PIECE OF THE
HIGH WILL BE CENTERED OVER THE FORECAST AREA. THE HIGH STAYS IN THE
REGION THROUGH THE WEEKEND.
ECMWF HAS BEEN PERSISTENT LAST FEW DAYS BRINGING COOLER AND DRIER
AIR MASS INTO THE FORECAST AREA WITH 850 MB TEMPERATURES IN +10 TO
+12 RANGE BY THURSDAY MORNING. THEN AIR MASS MODERATES ON FRIDAY AND
SATURDAY WITH NEAR NORMAL TEMPERATURES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1240 AM EDT SUNDAY...
PERSISTENT SHOWERS CONTINUE TO MEANDER ALONG A CORRIDOR FROM KLWB
SOUTH TO KPSK/KHLX TONIGHT WHERE LOW LEVEL MOISTURE CONVERGENCE
REMAINS UNDER THETA-E RIDGING AND SUPPORTED BY LOW LEVEL EASTERLY
FLOW. EXPECT THESE SHOWERS TO DRIFT SOUTH AND FINALLY FADE BY
DAYBREAK BUT STILL MAY NEED TO KEEP A VFR PREVAILING GROUP OR VCSH IN
AT KLWB A WHILE LONGER.
OTRW STRATOCUMULUS CLOUD COVER CONTINUES TO ALSO FILL IN UNDER
THE STRONG MID LEVEL INVERSION AND EXPECT ANOTHER WIDESPREAD
CANOPY BY DAYBREAK. HOWEVER STILL APPEARS THAT MOST SPOTS EAST OF
THE BLUE RIDGE WILL STAY WITH MAINLY LOW END VFR CIGS WHILE MVFR
TO IFR LIKELY OVER THE WEST ESPCLY WHERE RAIN HAS OCCURRED. PATCHY
MIST WILL REDUCE VISIBILITIES TO MVFR OR BRIEF IFR LEVELS MAINLY
WITHIN SOME THE MOUNTAIN AND RIVER VALLEYS.
ANY SUB-VFR CONDITIONS ARE EXPECTED TO IMPROVE TO VFR BY
15-16Z/11AM-NOON ON SUNDAY. ADDITIONAL ISOLATED TO SCATTERED
AFTERNOON SHOWERS ARE EXPECTED ON SUNDAY...ESPECIALLY ACROSS THE
MOUNTAINS BUT AGAIN TOO LOCALIZED TO INCLUDE MENTION IN THE TAFS
FOR NOW. HOWEVER WITH A SIMILAR SETUP TO TONIGHT...MAY SEE
ADDITIONAL SHOWERS LINGER IN SPOTS THROUGH SUNDAY NIGHT WITH
MOSTLY VFR CIGS EXCEPT MVFR OR WORSE NEAR ANY SHRA ESPCLY DURING
THE EVENING.
EXTENDED AVIATION DISCUSSION...
AS OF 125 PM EDT SATURDAY...
MONDAY INTO TUESDAY...SHOWERS AND STORMS INCREASE AGAIN ACROSS THE
REGION THANKS TO BOTH A FRONTAL BOUNDARY ENTERING THE REGION AND A
SHORTWAVE TROUGH PROGRESSING EASTWARD THROUGH THE OHIO VALLEY.
MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT SUB-VFR CONDITIONS
WHERE CONVECTION BECOMES MORE ORGANIZED. FOR NOW APPEARS THE BEST
CHANCE AT SEEING MORE WIDESPREAD POOR FLYING CONDITIONS WILL COME
LATER MONDAY INTO MONDAY EVENING AS AN AXIS OF DEEPER MOISTURE
PIVOTS ACROSS.
BY WEDNESDAY INTO THURSDAY...ANOTHER AREA OF HIGH PRESSURE BUILDS
INTO THE REGION MAKING FOR OVERALL VFR CONDITIONS. PATCHY LATE
NIGHT AND EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG WILL AGAIN
BE POSSIBLE...THOUGH AIRMASS WILL BE DRIER.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH/WP
NEAR TERM...SK/WP
SHORT TERM...AMS
LONG TERM...AMS
AVIATION...DS/JH/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1056 PM CDT MON AUG 10 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 246 PM CDT MON AUG 10 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DIFFUSE
SURFACE COLD FRONT SHIFTING SOUTH OVER SOUTHWEST TO EAST-CENTRAL
WISCONSIN EARLY THIS AFTERNOON. BUT BEHIND THE FRONT..INSTABILITY
HAS INCREASED TO OVER 800 J/KG ML CAPE AND TEMPERATURES HAVE
SURPASSED THE CONVECTIVE TEMP. WEAK CONVERGENCE IS ALSO DEVELOPING
ALONG THE BAY AND LAKE BREEZES. SO THINK WILL SEE SCATTERED SHOWERS
AND STORMS DEVELOP OVER EASTERN WI FOR THE REST OF THE AFTERNOON.
OTHER SHOWERS ARE POPPING UP OVER NORTHEAST MINNESOTA ASSOCIATED
WITH A SHORTWAVE TROUGH. THE TAIL END OF THE SHORTWAVE WILL
APPROACH FAR N-C WI LATE THIS AFTERNOON OR EARLY THIS EVENING...SO
WILL HAVE TO MONITOR FOR A SHOWER ADDITION TO THE FORECAST.
FORECAST CONCERNS INCLUDE PRECIP TRENDS...FOLLOWED BY CLOUD AND TEMP
TRENDS.
TONIGHT...RATHER DIFFUSE SURFACE COLD FRONT WILL SETTLE WELL SOUTH
OF THE REGION. BUT THE HIGHER RES MODELS CONTINUE TO POINT TOWARDS
WEAK LOW LEVEL CONVERGENCE CONTINUING INTO THE EVENING OVER EASTERN
WI...WITH SOME EXTRA UPPER LEVEL SUPPORT ARRIVING VIA THE SHORTWAVE
OVER WESTERN ONTARIO. INSTABILITY WEAKENS WITH LOSS OF DAYTIME
HEATING...BUT SOME DOES LINGER OVER EAST-CENTRAL WI THROUGH ABOUT
MID-EVENING. SO WILL KEEP AN ISOLATED SHOWER MENTION THROUGH ABOUT
03Z. THEREAFTER...SHOULD SEE SOME CLEARING TAKE PLACE OVER CENTRAL
AND NORTHEAST WISCONSIN. BUT STRATO-CU FROM NORTHERN MINNESOTA AND
ONTARIO WILL MAKE A RUN AT N-C WISCONSIN BY MID TO LATE EVENING.
DEWPOINTS WILL GRADUALLY FALL THROUGH THE NIGHT WHICH SHOULD SET UP
COOLER NIGHT TIME LOWS. LOWS FROM THE MID 50S NORTH TO LOW 60S SOUTH.
TUESDAY...HIGH PRESSURE WILL GRADUALLY BE BUILDING INTO THE REGION.
SHOULD SEE PLENTY OF DIURNAL CU POP WITH HEATING OF THE DAY BY LATE
MORNING BASED ON UPSTREAM OBS. ANY LOW STRATUS OVER N-C WI SHOULD
ALSO TURN INTO A CU FIELD...BUT NO SHOWER ACTIVITY IS EXPECTED.
HIGHS RANGING FROM THE LOW 70S NORTH TO AROUND 80 SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 246 PM CDT MON AUG 10 2015
MAJOR FEATURE DOMINATING THE CONUS THIS WEEK IS LARGE MID-LEVEL
RIDGE OVER THE CENTRAL PLAINS...EXPECTED TO AMPLIFY FURTHER AND
DRIFT BACK TOWARDS THE MOUNTAIN WEST. THIS WILL KEEP...AND EVEN
ENHANCE NORTHWEST FLOW ALOFT OVER OUR AREA. DESPITE THE NORTHWEST
FLOW...THE SHEER AMPLITUDE OF THE RIDGE WILL RESULT IN ABOVE
NORMAL HEIGHTS. PAIRED WITH A WEAK 850 MB HIGH OVER THE MIDDLE
MISSISSIPPI VALLEY ALLOWING FOR HIGHER TEMPS AT THAT
LEVEL...EXPECT HIGHS IN THE SECOND HALF OF THE WEEK TO BE NEAR
NORMAL OR ABOVE NORMAL. POTENTIAL FOR PRECIPITATION WILL COME
FROM MULTIPLE WEAK TROUGHS RIDING DOWN THE EAST SIDE OF THE RIDGE
STRAIGHT INTO THE WEEKEND.
A SUBTLE 500 MB VORT MAX LOOKS TO SCOOT NORTHEAST OF THE AREA
THROUGH THE UPPER PENINSULA WEDNESDAY AFTERNOON AND EVENING. AT
THE TIME...BOTH THE GFS AND EURO SUGGEST ABOUT 1000 J/KG OF CAPE
AND ABOUT 30 KNOTS OF SHEAR IN THE MICHIGAN BORDER REGION.
BUT...DEEP TEMPERATURE-DEWPOINT SPREADS AND THE LACK OF TRIGGERING
MECHANISM MAKE IT DIFFICULT TO SEE CONVECTIVE INITIATION EVEN
WITHOUT MUCH CAPPING PRESENT. STILL...BUFKIT TEMPS ARE VERY NEAR
THE CONVECTIVE TEMP SO STORMS CAN`T BE RULED OUT IN NORTH CENTRAL
AND FAR NORTHEAST WISCONSIN...AND THREW SLIGHT CHANCE POPS IN
THERE.
PERHAPS MORE SIGNIFICANT PRECIP POTENTIAL COMES THURSDAY INTO
FRIDAY...AS A WEAK COLD FRONT WILL CROSS THE REGION. AS WITH
WEDNESDAY...THERE APPEARS TO BE MODEST INSTABILITY AND SHEAR FOR
SOME STRONG STORMS. AGAIN...LOW LEVEL MOISTURE APPEARS TO BE A
LIMITING FACTOR...BUT AT LEAST ON THIS DAY WE HAVE THE FRONT AS A
FOCUSING MECHANISM. GIVEN SOME CAPPING PRESENT...THERE`S
SIGNIFICANT UNCERTAINTY ABOUT HOW MUCH COVERAGE WILL BE SEEN IN
ANY DEVELOPMENT. BUT HAVE HIGHER POPS THAN WEDNESDAY THANKS TO
THAT FRONTAL PRESENCE.
FINALLY...AFTER A MOSTLY DRY WEEKEND THANKS TO THE UPPER RIDGE
TILTING EASTWARD TOWARDS OUR AREA...WE`LL LOOK FOR TROUGHING OVER
CANADA TO BEAT DOWN THAT NORTHWARD EXTENT OF THE RIDGE AND PROVIDE
ANOTHER SHOT AT SHOWERS AND STORMS LATE SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT ALONG A COLD FRONT.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1054 PM CDT MON AUG 10 2015
SCATTERED MID CLOUDS WILL DISSIPATE OVERNIGHT WITH
SKIES BECOMING CLEAR. GROUND FOG IS NOT OUT OF THE QUESTION ACROSS
NORTHCENTRAL WISCONSIN AND PERHAPS NEAR LAKE MICHIGAN. VFR WEATHER
TUESDAY THROUGH WEDNESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
847 PM CDT MON AUG 10 2015
.UPDATE...
THE HRRR AND THE 18Z NAM CONTINUE TO SHOW THE POTENTIAL OF SOME
ISOLATED SHOWERS OVER PORTIONS OF FAR EAST CENTRAL AND SOUTHEAST
WISCONSIN LATER THIS EVENING THROUGH THE EARLY MORNING HOURS.
LOOKS LIKE IT/S FOCUSED ON SOME LOW LEVEL CONVERGENCE ALONG THE
LAKE COUPLED WITH SOME DEEP FORCING FROM A MID LEVEL SHORT WAVE
DIVING IN FROM THE NORTH. SOUNDINGS ARE STILL A BIT UNSTABLE SO
CAN/T RULE IT OUT BUT THE THREAT LOOKS VERY SMALL. DRY AIR IS
PUSHING IN FROM THE WEST...SO IT DOESN/T HAVE MUCH TIME. SATELLITE
IS LOOKING PRETTY QUIET WITH JUST A FEW CLOUDS ACROSS THE AREA.
OVERALL...A QUIET NIGHT AHEAD WITH THAT TREND CONTINUING OVER THE
NEXT FEW DAYS. DEW POINTS ARE DRYING OUT A BIT FASTER THAN
ORIGINALLY THOUGHT...SO MADE THAT ADJUSTMENT.
&&
.AVIATION/06Z TAFS/...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD WITH WINDS AT
OR BELOW 10KTS.
&&
.PREV DISCUSSION... /ISSUED 430 PM CDT MON AUG 10 2015/
TONIGHT...FORECAST CONFIDENCE - MEDIUM.
A 500MB TROUGH SWINGING THROUGH THE GREAT LAKES REGION... IN THE
VICINITY OF A FRONT... IS LEADING TO SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS SOUTHERN WI THIS AFTERNOON. THE VORTICITY
ADVECTION WITH AN EMBEDDED SHORTWAVE IS HELPING TO TRIGGER THE
THUNDERSTORMS. OUTFLOW BOUNDARIES AND THE LAKE BREEZE ARE ALSO
AIDING IN THEIR DEVELOPMENT. AN AREA OF 1000 J/KG CAPE DEPICTED ON
THE SPC MESOANALYSIS PAGE IS THE AREA OF FOCUS FOR THESE SCATTERED
THUNDERSTORMS. THE SHEAR IS WEAK... BUT THERE IS JUST ENOUGH
INSTABILITY TO PRODUCE HAIL UP TO AN INCH AND GUSTY WINDS UP TO 40
MPH. EXPECT THE CAPE TO DIMINISH EARLY THIS EVENING. SHOWERS WILL
TAPER OFF BY MID EVENING.
THE SURFACE COLD FRONT ALREADY WENT THROUGH THE AREA EARLY THIS
MORNING... BUT THE UPPER LEVEL COLD FRONT WILL NOT CLEAR SOUTHERN WI
UNTIL LATE TONIGHT. NORTHERLY WINDS WILL USHER DRIER AIR INTO
SOUTHERN WISCONSIN OVERNIGHT. THERE IS ONE MORE SHORTWAVE TO CROSS
THE AREA OVERNIGHT... BUT THAT SHOULD COME THROUGH DRY. THE COLUMN
WILL BE DRYING OUT AND IT IS ALSO COMING THROUGH DURING A DIURNALLY
UNFAVORABLE TIME OF DAY FOR CONVECTION.
TUESDAY... FORECAST CONFIDENCE HIGH.
DRY AIR WILL FINALLY SETTLE INTO SOUTHERN WISCONSIN ON TUESDAY.
EXPECT FAIR WEATHER CUMULUS CLOUDS AND A NORTHWEST BREEZE WITH GUSTS
UP TO 15 MPH. THE NORTHERLY WIND DIRECTION WILL BE FAVORABLE
FOR AN AFTERNOON LAKE BREEZE. HIGHS IN THE MID 70S TO AROUND 80.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT - FORECAST CONFIDENCE...HIGH.
QUIET CONDITIONS FOR THIS PERIOD WITH DRIER AIR NORTHWEST FEED AS
HIGH PRESSURE PASSES THROUGH. NAM GUIDANCE IS OUTLIER WITH REGARDS
TO COMPACT MID-LEVEL SHORT WAVE MOVING THROUGH EASTERN WI WED AFTN
AND EVE SO WL CONTINUE DRY FORECAST. MAY BE SOME LATE NIGHT RIVER
VALLEY FOG TUESDAY NIGHT DUE TO LIGHT BOUNDARY LAYER FLOW.
THURSDAY - FORECAST CONFIDENCE...MEDIUM.
FASTER NORTHWEST STEERING WINDS BRINGING UPSTREAM COLD FRONT
SOUTHWARD ACROSS WISCONSIN ABOUT 12 HOURS EARLIER. HENCE WL
INTRODUCE SMALL POPS TO NORTHERN CWA...BUT FORECAST SOUNDINGS SHOW
QUITE A BIT OF CONVECTIVE INHIBITION LINGERING THROUGH THE
AFTERNOON. HENCE ONLY WENT WITH SCHC POPS AT THIS POINT.
EXTENDED PERIOD - THURSDAY NIGHT AND FRIDAY - FORECAST
CONFIDENCE...LOW
AS DESCRIBED ABOVE...ALL MEDIUM RANGE GUIDANCE IN REASONABLE
AGREEMENT ON FAST NORTHWEST STEERING FLOW CARRYING WEAK COLD FRONT
ACROSS WI ABOUT 12 HOURS EARLIER THAN ANTICIPATED. COLD FRONT NOW
EXPECTED TO MOVE THRU SRN WI MAINLY THU NIGHT IN RESPONSE TO
AMPLIFYING BLOCKING RIDGE INTO S CENTRAL CANADA AND SHORT WAVE TROF
MOVING EASTWARD...JUST NORTH OF THE GTLAKES. PWAT VALUES INCREASE
TO AROUND 1.5 INCHES PER GFS AHEAD OF FRONT. FAVORED PERIOD FOR
CONVECTION WL BE THU NIGHT WITH DECREASING THREAT ON FRI. HOWEVER
WL CONTINUE LOW POPS INTO FRIDAY DUE TO LINGERING UNCERTAINTY.
EXTENDED PERIOD - FRIDAY NIGHT THROUGH MONDAY - FORECAST
CONFIDENCE...MEDIUM.
STRONGER NORTHWEST STEERING FLOW SHOULD CARRY FRONT WELL SOUTH OF
AREA BY FRIDAY. HIGH PRESSURE WILL RESUME CONTROL WITH DRY AND
SLIGHTLY ABOVE NORMAL TEMPERATURES TO START THE WEEKEND. UPSTREAM
BLOCKING RIDGE WILL SUCCUMB TO STRONGER LOW PRESSURE WAVE MOVING
ACROSS SOUTHWEST CANADA AND FLATTEN ACROSS THE NORTHERN CONUS INTO
CANADA ON SAT. INCREASING WEST TO SOUTHWEST WINDS ACROSS THE UPPER
MIDWEST WILL ALLOW WARMER AIR TO RETURN ON SUNDAY. MEDIUM
RANGE GUIDANCE IN AGREEMENT ON SOUTHERN EXTENSION OF CANADA SHORT
WAVE AFFECTING WI SUNDAY NIGHT ALONG WITH DRAGGING A WEAK FRONT
THROUGH THE REGION. AT THIS POINT...THIS MAY BE OUR BEST CHANCE IN
THE NEXT WEEK FOR MORE WIDESPREAD CONVECTION.
AVIATION/00Z TAFS/...
SCATTERED SHOWERS AND THUNDERSTORMS WILL DIMINISH FROM NW TO SE
THROUGH EARLY EVENING. THESE ARE DUE TO THE PASSAGE OF AN UPPER
LEVEL COLD FRONT. LOWER CIGS AND VSBY AND WIND GUSTS UP TO 35 KT
POSSIBLE IN ANY THUNDERSTORMS. NORTHERLY WINDS WILL USHER DRIER AIR
INTO THE REGION OVERNIGHT... SO FOG POTENTIAL IS VERY LOW. LOOK FOR
SCATTERED VFR CUMULUS CLOUDS ACROSS SOUTHERN WI ON TUESDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...DAVIS
TONIGHT/TUESDAY AND AVIATION/MARINE...MRC
TUESDAY NIGHT THROUGH MONDAY...MBK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
747 PM CDT MON AUG 10 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 246 PM CDT MON AUG 10 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DIFFUSE
SURFACE COLD FRONT SHIFTING SOUTH OVER SOUTHWEST TO EAST-CENTRAL
WISCONSIN EARLY THIS AFTERNOON. BUT BEHIND THE FRONT..INSTABILITY
HAS INCREASED TO OVER 800 J/KG ML CAPE AND TEMPERATURES HAVE
SURPASSED THE CONVECTIVE TEMP. WEAK CONVERGENCE IS ALSO DEVELOPING
ALONG THE BAY AND LAKE BREEZES. SO THINK WILL SEE SCATTERED SHOWERS
AND STORMS DEVELOP OVER EASTERN WI FOR THE REST OF THE AFTERNOON.
OTHER SHOWERS ARE POPPING UP OVER NORTHEAST MINNESOTA ASSOCIATED
WITH A SHORTWAVE TROUGH. THE TAIL END OF THE SHORTWAVE WILL
APPROACH FAR N-C WI LATE THIS AFTERNOON OR EARLY THIS EVENING...SO
WILL HAVE TO MONITOR FOR A SHOWER ADDITION TO THE FORECAST.
FORECAST CONCERNS INCLUDE PRECIP TRENDS...FOLLOWED BY CLOUD AND TEMP
TRENDS.
TONIGHT...RATHER DIFFUSE SURFACE COLD FRONT WILL SETTLE WELL SOUTH
OF THE REGION. BUT THE HIGHER RES MODELS CONTINUE TO POINT TOWARDS
WEAK LOW LEVEL CONVERGENCE CONTINUING INTO THE EVENING OVER EASTERN
WI...WITH SOME EXTRA UPPER LEVEL SUPPORT ARRIVING VIA THE SHORTWAVE
OVER WESTERN ONTARIO. INSTABILITY WEAKENS WITH LOSS OF DAYTIME
HEATING...BUT SOME DOES LINGER OVER EAST-CENTRAL WI THROUGH ABOUT
MID-EVENING. SO WILL KEEP AN ISOLATED SHOWER MENTION THROUGH ABOUT
03Z. THEREAFTER...SHOULD SEE SOME CLEARING TAKE PLACE OVER CENTRAL
AND NORTHEAST WISCONSIN. BUT STRATO-CU FROM NORTHERN MINNESOTA AND
ONTARIO WILL MAKE A RUN AT N-C WISCONSIN BY MID TO LATE EVENING.
DEWPOINTS WILL GRADUALLY FALL THROUGH THE NIGHT WHICH SHOULD SET UP
COOLER NIGHT TIME LOWS. LOWS FROM THE MID 50S NORTH TO LOW 60S SOUTH.
TUESDAY...HIGH PRESSURE WILL GRADUALLY BE BUILDING INTO THE REGION.
SHOULD SEE PLENTY OF DIURNAL CU POP WITH HEATING OF THE DAY BY LATE
MORNING BASED ON UPSTREAM OBS. ANY LOW STRATUS OVER N-C WI SHOULD
ALSO TURN INTO A CU FIELD...BUT NO SHOWER ACTIVITY IS EXPECTED.
HIGHS RANGING FROM THE LOW 70S NORTH TO AROUND 80 SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 246 PM CDT MON AUG 10 2015
MAJOR FEATURE DOMINATING THE CONUS THIS WEEK IS LARGE MID-LEVEL
RIDGE OVER THE CENTRAL PLAINS...EXPECTED TO AMPLIFY FURTHER AND
DRIFT BACK TOWARDS THE MOUNTAIN WEST. THIS WILL KEEP...AND EVEN
ENHANCE NORTHWEST FLOW ALOFT OVER OUR AREA. DESPITE THE NORTHWEST
FLOW...THE SHEER AMPLITUDE OF THE RIDGE WILL RESULT IN ABOVE
NORMAL HEIGHTS. PAIRED WITH A WEAK 850 MB HIGH OVER THE MIDDLE
MISSISSIPPI VALLEY ALLOWING FOR HIGHER TEMPS AT THAT
LEVEL...EXPECT HIGHS IN THE SECOND HALF OF THE WEEK TO BE NEAR
NORMAL OR ABOVE NORMAL. POTENTIAL FOR PRECIPITATION WILL COME
FROM MULTIPLE WEAK TROUGHS RIDING DOWN THE EAST SIDE OF THE RIDGE
STRAIGHT INTO THE WEEKEND.
A SUBTLE 500 MB VORT MAX LOOKS TO SCOOT NORTHEAST OF THE AREA
THROUGH THE UPPER PENINSULA WEDNESDAY AFTERNOON AND EVENING. AT
THE TIME...BOTH THE GFS AND EURO SUGGEST ABOUT 1000 J/KG OF CAPE
AND ABOUT 30 KNOTS OF SHEAR IN THE MICHIGAN BORDER REGION.
BUT...DEEP TEMPERATURE-DEWPOINT SPREADS AND THE LACK OF TRIGGERING
MECHANISM MAKE IT DIFFICULT TO SEE CONVECTIVE INITIATION EVEN
WITHOUT MUCH CAPPING PRESENT. STILL...BUFKIT TEMPS ARE VERY NEAR
THE CONVECTIVE TEMP SO STORMS CAN`T BE RULED OUT IN NORTH CENTRAL
AND FAR NORTHEAST WISCONSIN...AND THREW SLIGHT CHANCE POPS IN
THERE.
PERHAPS MORE SIGNIFICANT PRECIP POTENTIAL COMES THURSDAY INTO
FRIDAY...AS A WEAK COLD FRONT WILL CROSS THE REGION. AS WITH
WEDNESDAY...THERE APPEARS TO BE MODEST INSTABILITY AND SHEAR FOR
SOME STRONG STORMS. AGAIN...LOW LEVEL MOISTURE APPEARS TO BE A
LIMITING FACTOR...BUT AT LEAST ON THIS DAY WE HAVE THE FRONT AS A
FOCUSING MECHANISM. GIVEN SOME CAPPING PRESENT...THERE`S
SIGNIFICANT UNCERTAINTY ABOUT HOW MUCH COVERAGE WILL BE SEEN IN
ANY DEVELOPMENT. BUT HAVE HIGHER POPS THAN WEDNESDAY THANKS TO
THAT FRONTAL PRESENCE.
FINALLY...AFTER A MOSTLY DRY WEEKEND THANKS TO THE UPPER RIDGE
TILTING EASTWARD TOWARDS OUR AREA...WE`LL LOOK FOR TROUGHING OVER
CANADA TO BEAT DOWN THAT NORTHWARD EXTENT OF THE RIDGE AND PROVIDE
ANOTHER SHOT AT SHOWERS AND STORMS LATE SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT ALONG A COLD FRONT.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 746 PM CDT MON AUG 10 2015
THERE IS A SMALL CHANCE OF A BRIEF SHOWER NEAR THE BAY
AND LAKE THIS EVENING...OTHERWISE SKIES SHOULD CLEAR TONIGHT.
GROUND FOG IS NOT OUT OF THE QUESTION IN A FEW PLACES BUT NOT
CONFIDENT ENOUGH TO INCLUDE IN THE FORECAST. VFR WEATHER TUESDAY
THROUGH TUESDAY NIGHT WITH FAIRLY LIGHT WINDS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
323 PM CDT SUN AUG 9 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 323 PM CDT SUN AUG 9 2015
MAIN FOCUS IS THE RAIN RISK TONIGHT THROUGH MONDAY. FRONTAL
BOUNDARY HELPED TO MAINTAIN A FOCUS FOR CONVECTIVE DEVELOPMENT
ACROSS CENTRAL MN THROUGH THE DAY...ASSISTED GREATLY BY THE MCV
FROM THE SOUTH DAKOTA CONVECTION OVERNIGHT. THIS CLUSTER RAMPED
UP SHORTLY AFTER THE NOON HOUR...AND WAS PROGRESSING ACROSS
NORTHERN WI. MEANWHILE...THE TRAILING EDGE OF THE FRONT REACHED
WEST BACK INTO EASTERN SD. SOUTHEAST WINDS HAVE FED BOUNDARY LAYER
MOISTURE INTO THIS BOUNDARY...AND AS AFTERNOON HEATING MAXIMIZED
INSTABILITY...NEW CONVECTION IS FORMING. WATER VAPOR IMAGERY AND
MODELS SHOW A SHORT WAVE MOVING THROUGH THE FLOW IN THIS AREA AS
WELL. EXPECT THIS SD CONVECTIVE ACTIVITY TO MOVE EAST TOWARD THE
AREA OVERNIGHT. HAVE INCREASED RAIN CHANCES IN THE FORECAST DURING
THE EVENING HOURS...AND A LITTLE BIT OVERNIGHT. MODELS ARE
INSISTENT THAT THIS WILL ALL WEAKEN OR EVEN FIZZLE OUT
OVERNIGHT...AND HENCE OUR LOWER POP CHANCES. BUT IF THE SD
ACTIVITY CONTINUES TO RAMP UP AND GENERATES ANOTHER MCV...THOSE
OVERNIGHT CHANCES WILL HAVE TO BE INCREASED.
DURING THE DAY MONDAY...THE WAVE PASSES...AND THE FRONT SHIFTS
SOUTH OF THE REGION. ANOTHER SHORT WAVE TROUGH ROTATES AROUND THE
HUDSON BAY UPPER TROUGH AND DROPS INTO THE GREAT LAKES LATE
MONDAY. THIS LOOKS TO GENERATE SOME AFTERNOON SHRA/TSRA...BUT THAT
ACTION LOOKS TO REMAIN NORTHEAST OF OUR FORECAST AREA. THIS ALSO
BEARS WATCHING HOWEVER...AS SOMEWHAT STEEP LAPSE RATES IN THE COOL
AIR REGIME COULD ASSIST DEVELOPMENT OF ROBUST CUMULUS THAT COULD
GENERATE PRECIP.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 323 PM CDT SUN AUG 9 2015
THE TROUGH PASSES AND HIGH PRESSURE MOVES IN BY MONDAY NIGHT.
COOLER AIR WILL ALSO BE POURING IN...SETTING THE STAGE FOR A
COUPLE OF COOL NIGHTS. LOWS LOOK TO BE IN THE 50S AND LOWER 60S
BY TUESDAY MORNING...AND EVEN A BIT COOLER WEDNESDAY MORNING.
WOULD NOT BE SURPRISED TO SEE SOME 40S OVER THE TYPICAL COOL SPOT
AREAS. WITH THE COOL TEMPS AND LIGHT WINDS BOTH TUE/WED MORNING...
ANTICIPATE THAT VALLEY FOG WILL ONCE AGAIN BECOME PREVALENT.
THE RIDGE HOLDS THROUGH THURSDAY BEFORE THE NEXT SHORT WAVE MOVES
OVER THE TOP AND DROPS INTO THE AREA BY THURSDAY NIGHT. WHILE THE
GREATEST SUPPORT LOOKS TO PRIMARILY BE NORTH AND EAST OF THE
AREA...A CROSSING BOUNDARY AND ENOUGH THERMODYNAMIC ASSISTANCE IS
PRESENT FOR AT LEAST A CHANCE FOR SOME RAIN.
A BRIEF PERIOD OF RIDGING LOOKS LIKELY FRI/SAT...ALONG WITH A
RETURN TO MORE WARM AND HUMID WEATHER. THE MODELS ARE TRENDING
TOWARD A SIGNIFICANT UPPER SYSTEM OVER WESTERN CANADA...PUSHING
THE UPPER RIDGE OVER OUR AREA...AND EVENTUALLY LEADING TO THE
PASSAGE OF A STRONG COLD FRONT. AT THIS TIME IT LOOKS LIKE THIS
WOULD OCCUR LATE SUNDAY OR EVEN MONDAY. BUT THE TIMING IS
DIFFICULT TO PIN DOWN IN THIS EVOLVING PATTERN SHIFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1204 PM CDT SUN AUG 9 2015
WEAK COLD FRONT ACROSS FAR NORTHWEST WISCONSIN INTO SOUTHWEST
MINNESOTA IS EXPECTED TO CONTINUE MOVING SLOWLY SOUTHEAST WHILE
WEAKENING. WHAT REMAINS OF THE FRONT SHOULD PASS THROUGH THE AREA
THIS EVENING WITH A WIND SHIFT TO THE NORTH NORTHWEST BUT WITH
VERY LIGHT WIND SPEEDS. CONVECTIVE ACTIVITY ALONG THE FRONT OVER
WESTERN MINNESOTA IS SHOWN BY THE 09.15Z RUN OF THE HRRR TO
CONTINUE MOVING EAST BEFORE WEAKENING OVER WISCONSIN WHILE STAYING
TO THE NORTH OF BOTH TAF SITES. OTHER CONVECTION MAY FORM OVER
SOUTHWEST MINNESOTA AND MOVE SOUTHEAST INTO IOWA MISSING THE TAF
SITES TO THE SOUTH. FOR NOW...DO NOT PLAN TO SHOW ANY RAIN CHANCES
FOR EITHER SITE AND WILL BRING THE FRONT THROUGH WITH JUST A HIGH
VFR CEILING. SOME POTENTIAL FOR FOG AGAIN TONIGHT AS THE WINDS
WILL BE LIGHT AND MAY NOT CHANGE OVER THE BOUNDARY LAYER ENOUGH TO
HELP LOWER THE DEW POINTS. RIGHT NOW THINKING THE CLOUDS WITH THE
FRONT WILL KEEP THE FOG FROM FORMING...BUT IF THESE DO NOT
OCCUR...THE CONDITIONS FOR FOG FORMATION WILL BE MUCH BETTER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...MW
LONG TERM...MW
AVIATION...04
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 214 PM CDT SUN AUG 9 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD
FRONT STRETCHING FROM SOUTHWEST MINNESOTA TO THE WESTERN UPPER
PENINSULA. THIS FRONT HAS BEEN MOSTLY INACTIVE SO FAR
TODAY...OUTSIDE OF A FEW SHOWERS OVER VILAS COUNTY EARLY THIS
MORNING. LOW STRATUS OVER NORTHERN WISCONSIN HAVE HELD BACK TEMPS
SOMEWHAT...WHICH IS KEEPING INSTABILITY LIMITED TO UNDER 800 J/KG SO
FAR THIS AFTERNOON. THE STRATUS IS SHOWING NO SIGNS OF BREAKING UP
EITHER. BIGGER CONCERNS REVOLVE AROUND THE SHOWERS AND
THUNDERSTORMS MOVING INTO WESTERN WISCONSIN ASSOCIATED WITH A
SHORTWAVE IMPULSE. THUNDERSTORMS ARE EXPANDING WITHIN THE
INSTABILITY AXIS OVER NORTHWEST WISCONSIN...AND A ROUGH TIMING SHOWS
STORMS MOVING INTO NORTH-CENTRAL WISCONSIN IN THE 3-5PM RANGE. DUE
TO THE LIMITED INSTABILITY...STILL THE SEVERE THREAT IS RATHER LOW.
BUT SMALL HAIL AND GUSTY STRAIGHT LINE WINDS WILL BE POSSIBLE.
FORECAST CONCERNS REVOLVE AROUND THUNDERSTORM POTENTIAL.
TONIGHT...THE COLD FRONT WILL REMAIN NEARLY STATIONARY FOR THE REST
OF THE AFTERNOON...AND THEN SHIFT SOUTHEAST AS THE SHORTWAVE IMPULSE
MOVES ACROSS THE AREA THIS EVENING. SHOWERS AND THUNDERSTORMS NOW
LOOK LIKELY ACROSS MOST OF THE AREA THIS EVENING...EXCEPT FOR MAYBE
THE SOUTHERN TIER. HAVE INCREASED PRECIP CHANCES INTO THE LIKELY
RANGE...AS THE SHORTWAVE SHOULD BE ABLE TO INTERACT WITH SOME OF
LINGERING DAYTIME INSTABILITY. THE RAINFALL SHOULD HELP GIVE SOME
SOUTHEAST PUSH TO THE COLD FRONT WHICH WILL MOVE INTO EAST-CENTRAL
WISCONSIN LATE. WITH THE RAINFALL AND FRONT NEARBY...THINK LOW
STRATUS AND/OR FOG WILL REDEVELOP AFTER MIDNIGHT. SOME DENSE FOG
LIKE EARLY THIS MORNING IS POSSIBLE IN SPOTS.
MONDAY...THE FRONT DOES NOT MAKE MUCH PROGRESS SOUTHWARD...LEAVING
NORTHEAST WISCONSIN IN CLOSE PROXIMITY TO THE FRONT. THOUGH HAVE
SOME CONCERN THAT TONIGHTS RAIN WILL PUSH THE FRONT SOUTH OF THE
AREA...LEFT A CHANCE OF STORMS IN THE FORECAST DURING THE AFTERNOON
OVER THE EAST. NO SEVERE STORMS ARE EXPECTED DUE TO MEAGER 0-6KM
SHEAR OF 10 KTS. HIGHS TO RANGE FROM THE MID 70S TO LOW 80S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 214 PM CDT SUN AUG 9 2015
A TRANSITION IN THE UPPER LEVEL FLOW IS EXPECTED STARTING
TUESDAY...WHEN HIGH PRESSURE WILL STRENGTHEN OVER THE ROCKIES IN A
BLOCKING PATTERN THAT WILL KEEP THE NORTHEAST U.S. UNDER A LOW
PRESSURE TROUGH AND WISCONSIN UNDER A NORTHWEST FLOW. THIS
SCENARIO WILL PRODUCE DRIER CONDITIONS IN GENERAL FOR NORTHEAST
WISCONSIN...ALTHOUGH MODELS AGREE ON A CHANCE FOR PRECIPITATION
LATER IN THE WORK WEEK AS A WEAK COLD FRONT SWEEPS DOWN ON THE
NORTHWEST FLOW OUT OF CANADA.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1149 AM CDT SUN AUG 9 2015
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON ALONG A WEAK COLD FRONT OVER NORTHERN WISCONSIN. AN UPPER
LEVEL DISTURBANCE OVER MINNESOTA WILL HELP MAKE COVERAGE MORE
WIDESPREAD...SO INCLUDED A TEMPO GROUP FOR STORMS AT AUW/CWA THIS
EVENING. UNCERTAINTY INCREASES FURTHER EAST DUE TO THE LATER
ARRIVAL OF THE FRONT/UPPER DISTURBANCE AND NIGHT TIME STABILIZATION.
ESPECIALLY IF THERE IS RAINFALL...LOWER CIGS AND VSBYS ARE EXPECTED
TO REDEVELOP TONIGHT AND THEN IMPROVE AGAIN BY MID MORNING ON MONDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ML
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1204 PM CDT SUN AUG 9 2015
.SHORT TERM...(TODAY INTO MONDAY)
ISSUED AT 230 AM CDT SUN AUG 9 2015
TWO AREAS OF CONVECTION EARLY THIS MORNING. FIRST IS AN MCS FUELED
BY LOW LEVEL MOISTURE TRANSPORT AND DRIVEN BY AN UPPER LEVEL
SHORTWAVE - TRACKING EAST ACROSS EASTERN IA. RADAR AND MESO MODEL
TRENDS CONTINUE TO MOVE THIS EAST/SOUTHEAST...LIKELY AWAY FROM
NORTHEAST IA/SOUTHWEST WI BY 12Z. MEANWHILE TO THE NORTH...SCATTERED
CONVECTION OVER NORTHEAST MN/NORTHWEST WI IS BEING SPARKED BY A
FRONTOGENETIC REGION ASSOCIATED WITH A SHORTWAVE SLIDING ACROSS
SOUTHERN CANADA. WANING INSTABILITY/WEAKENING MOISTURE TRANSPORT IN
THIS REGION SHOULD LEAD TO A DECREASE IN COVERAGE THROUGH THE EARLY
MORNING HOURS.
THIS NORTHERN BOUNDARY COULD ACT TO SPARK A FEW MORE SHOWERS/STORMS
LATER TODAY AS A RIBBON OF INSTABILITY IS ANTICIPATED TO REDEVELOP
AROUND IT. ITS NOT AN OVERLY CONVERGENT BOUNDARY...BUT ENOUGH TO
INCLUDE SMALL CHANCES...ESPECIALLY LATE AFTERNOON/EARLY EVENING.
NEXT...RIPPLE IN THE UPPER LEVEL FLOW IS PROGGED TO MOVE SOUTHEAST
ACROSS THE NORTHERN PLAINS...TAKING AIM ON IA EARLY MONDAY MORNING.
MODELS HAVE ANOTHER MCS DEVELOP IN RESPONSE...WITH THE BRUNT OF ITS
IMPACT AGAIN FOCUSED ON THE HAWKEYE STATE. THERE WILL LIKELY BE SOME
INTERACTION BETWEEN THE SHORTWAVE AND LINGERING SFC FRONT...WITH
SOME PCPN CHANCES EXTENDING NORTH/EAST ALONG THE BOUNDARY.
HOWEVER...THE BULK OF THE PCPN THREAT/AMOUNTS LOOKS TO BE JUST
WEST/SOUTH OF THE LOCAL AREA.
OVERALL...THOSE IN THE I-90 CORRIDOR AND NORTH WHO WERE HOPING FOR
SOAKING RAINS MIGHT BE DISAPPOINTED AS THE HIGHER CHANCES WILL HOLD
SOUTH OF THERE THROUGH MONDAY.
.LONG TERM...(TUESDAY INTO SATURDAY)
ISSUED AT 230 AM CDT SUN AUG 9 2015
MODELS REMAIN IN GOOD AGREEMENT WITH AMPLIFYING AN UPPER LEVEL RIDGE
OVER THE HEART OF THE U.S. THIS WEEK...KEEPING THE UPPER MISSISSIPPI
RIVER VALLEY UNDER NORTHWEST FLOW. AT THE SFC...A HIGH IS STILL
PROGGED TO DROP OUT OF CANADA AND ACROSS THE AREA TUE-THU. THE SETUP
IS FAVORABLE FOR RIVER VALLEY FOG...WITH WED MORNING CURRENTLY
LOOKING THE MOST LIKELY.
THE UPPER LEVEL RIDGE NEVER QUITE MAKES IT TO THE GREAT LAKES AS THE
VARIOUS LONG TERM MODELS DRIVE SHORTWAVE TROUGHS ACROSS THE TOP OF
IT...WITH SOME HINTS THAT EITHER THE FLOW WILL BECOME MORE ZONAL
TOWARD THE END OF NEXT WEEKEND...OR THE RIDGE WILL REESTABLISH
ITSELF OVER THE WEST COAST.
IT SHOULD STAY DRY INTO THU...BUT THEN THE GFS/EC DROP A BIT OF
UPPER LEVEL ENERGY OVER THE RIDGE AND ACROSS THE GREAT LAKES THU
AFTERNOON/NIGHT. WHILE THE BULK OF THE LIFT STAYS NORTH/EAST OF THE
LOCAL AREA...AN ASSOCIATED SFC FRONT LOOKS TO DROP SOUTH ACROSS THE
REGION. SOME MOISTURE TRANSPORT INTO THE BOUNDARY AND INSTABILITY TO
PLAY WITH SHOULD SPARK AT LEAST SCATTERED CONVECTION ALONG IT. THIS
BOUNDARY WILL SLIDE SOUTH BUT COULD GET CAUGHT UP WEST-EAST ACROSS
IA/ILL...REMAINING A POTENTIAL FOCUS FOR SHOWERS/STORMS INTO THE
WEEKEND.
FOR TEMPERATURES...WHILE THE RIDGE AXIS STAYS TO THE WEST...MODELS
ARE STARTING TO SUGGEST THAT SOME OF THAT WARMER AIR WILL WORK
ACROSS THE FORECAST AREA. INSTEAD OF AT OR BELOW NORMAL HIGHS...TEMPS
COULD WARM TO AT OR ABOVE NORMAL AS THE WEEK PROGRESSES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1204 PM CDT SUN AUG 9 2015
WEAK COLD FRONT ACROSS FAR NORTHWEST WISCONSIN INTO SOUTHWEST
MINNESOTA IS EXPECTED TO CONTINUE MOVING SLOWLY SOUTHEAST WHILE
WEAKENING. WHAT REMAINS OF THE FRONT SHOULD PASS THROUGH THE AREA
THIS EVENING WITH A WIND SHIFT TO THE NORTH NORTHWEST BUT WITH
VERY LIGHT WIND SPEEDS. CONVECTIVE ACTIVITY ALONG THE FRONT OVER
WESTERN MINNESOTA IS SHOWN BY THE 09.15Z RUN OF THE HRRR TO
CONTINUE MOVING EAST BEFORE WEAKENING OVER WISCONSIN WHILE STAYING
TO THE NORTH OF BOTH TAF SITES. OTHER CONVECTION MAY FORM OVER
SOUTHWEST MINNESOTA AND MOVE SOUTHEAST INTO IOWA MISSING THE TAF
SITES TO THE SOUTH. FOR NOW...DO NOT PLAN TO SHOW ANY RAIN CHANCES
FOR EITHER SITE AND WILL BRING THE FRONT THROUGH WITH JUST A HIGH
VFR CEILING. SOME POTENTIAL FOR FOG AGAIN TONIGHT AS THE WINDS
WILL BE LIGHT AND MAY NOT CHANGE OVER THE BOUNDARY LAYER ENOUGH TO
HELP LOWER THE DEW POINTS. RIGHT NOW THINKING THE CLOUDS WITH THE
FRONT WILL KEEP THE FOG FROM FORMING...BUT IF THESE DO NOT
OCCUR...THE CONDITIONS FOR FOG FORMATION WILL BE MUCH BETTER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
944 PM MDT MON AUG 10 2015
.UPDATE...
ISSUED AT 938 PM MDT MON AUG 10 2015
GRIDDED FORECASTS UPDATED TO ADJUST POPS THE REST OF THIS EVENING
FOR SHOWERS AND THUNDERSTORMS OVER KIMBALL COUNTY NEBRASKA AND
A FEW SHOWERS OVER WESTERN NEBRASKA. EXPECT THESE SHOWERS TO BE
OVER BY MIDNIGHT. LATEST 00Z NAM AND HRRR INDICATING LOW CLOUDS
AND FOG ALONG THE SOUTHERN LARAMIE RANGE FROM CHEYENNE TO PINE
BLUFFS AND OVER THE SUMMIT LATER TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
WE ARE STARTING TO SEE A FEW BUILDUPS ACROSS THE SOUTHERN LARAMIE
RANGE IN WYOMING AS WELL AS IN A ZONE OF DIFFERENTIAL HEATING ON
THE NORTH SIDE OF THE NORTH PLATTE RIVER VALLEY ACROSS THE
NEBRASKA PANHANDLE NORTH OF SCOTTSBLUFF. DONT THINK MOST STORMS
WILL GET OVERLY ROWDY THIS AFTERNOON AND EVENING...ALTHOUGH WITH
SBCAPES RUNNING IN THE 1200-1600 J/KG RANGE OVER THE PANHANDLE WE
COULD SEE A FEW STRONGER UPDRAFTS TO SUPPORT ISOLATED
STRONG/BRIEFLY MARGINALLY SEVERE STORMS...ALTHOUGH TYPICAL OF
AUGUST MIDLEVELS ARE FAIRLY WARM. MOST OF THE CONVECTION IS
EXPECTED TO FIRE ALONG AND JUST EAST OF THE LARAMIE RANGE THIS
AFTERNOON WITH ISOLATED STORMS EXPECTED THROUGH MID EVENING OVER
THE PANHANDLE.
RATHER AMPLIFIED UPPER RIDGE EXTENDS NORTH ACROSS THE CENTRAL AND
NORTHERN ROCKIES WITH OUR FORECAST AREA SEEING A GRADUAL INCREASE
IN MIDLEVEL MOISTURE FROM THE SOUTHWEST THROUGH MID WEEK. WILL SEE
SCATTERED STORMS TOMORROW AFTERNOON FIRE OVER THE SIERRA MADRE,
SNOWY AND SOUTHERN LARAMIE RANGE WITH ISOLATED STORMS EAST ONTO
THE PLAINS. BOTH THE GFS AND THE NAM SUPPORT THE NOTION OF A
SHORTWAVE RIDING NORTHEAST ACROSS OUR AREA WEDNESDAY AND THAT WILL
SUPPORT AN INCREASE IN POPS FOR WEDNESDAY AFTERNOON...ESPECIALLY
OUT WEST ALONG AND WEST OF THE LARAMIE RANGE WITH ISOLATED POPS
FARTHER EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 439 PM MDT MON AUG 10 2015
THERE IS THE POSSIBILITY OF LOWER FLIGHT CONDITIONS FOR SOME
AIRPORTS IN THE SOUTHERN PANHANDLE AND HERE AT CHEYENNE. LATEST
ALTERNATIVE HRRR AND SREF GUIDANCE IS SHOWING KSNY...KCYS AND
POSSIBLY KBFF GOING DOWN IN FOG AND STRATUS AFTER 09Z OR SO
TUESDAY MORNING. WILL TRY TO NARROW DOWN TIMING AND AIRPORTS ON
THE 06Z TAFS. BEST CHANCES LOOK TO BE HERE AT KCYS OVERNIGHT.
SOUTHEAST UPSLOPING WINDS TO CONTINUE THROUGH LATE MORNING TUESDAY
BEFORE TURNING MORE WESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 242 PM MDT MON AUG 10 2015
STILL EXPECTING NO MAJOR FIRE WEATHER CONCERNS THROUGH AT LEAST
WEDNESDAY WITH WIND GUSTS (AWAY FROM THUNDERSTORMS) EXPECTED TO
REMAIN BELOW 25 MPH AND HUMIDITIES AT OR ABOVE 20 PERCENT FOR MOST
LOCATIONS. WE WILL SEE ISOLATED TO SCATTERED THUNDERSTORMS THROUGH
MID WEEK IN THE AFTERNOON AND EARLY EVENING HOURS...WITH THE MAIN
THREATS FROM THESE BEING CLOUD TO GROUND LIGHTNING AND
GUSTY/ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...JG
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
915 PM MST MON AUG 10 2015
.SYNOPSIS...
SOUTHERLY FLOW ALOFT WILL GRADUALLY INCREASE MOISTURE LEVELS THROUGH
TUESDAY...WITH TUESDAY AFTERNOON AND EVENING HAVING THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS ACROSS ARIZONA. VERY STRONG HIGH
PRESSURE WILL BUILD INTO THE REGION FROM THE EAST BRINGING MUCH
ABOVE NORMAL TEMPERATURES AND REDUCED THUNDERSTORM CHANCES FROM
WEDNESDAY INTO SATURDAY. COOLER TEMPERATURES AND BETTER CHANCES FOR
STORMS WILL RETURN EARLY NEXT WEEK.
&&
.DISCUSSION...
LATEST CAMS CONTINUE TO SUGGEST THE POSSIBILITY OF ISOLATED
CONVECTION AS FAR WEST AS THE PHOENIX AREA...THOUGH AREAS TO THE
EAST TOWARDS GILA COUNTY ARE SOMEWHAT MORE FAVORED. LOCAL 00Z AND
03Z KPSR SOUNDING DATA SHOWED SFC-H8 MIXING RATIOS NEAR 10
G/KG...HOWEVER DROPPING OFF STEADILY TOWARDS THE H7 LAYER RESULTING
IN SUBSTANTIAL CINH. 00Z KTWC SOUNDING WAS SOMEWHAT MORE FAVORABLE
DEPICTING A DEEPER MOISTURE PROFILE...HOWEVER THE LACK OF ORGANIZED
CONVECTION AND DEEPER OUTFLOW BOUNDARIES HAS PRECLUDED THE INGEST OF
MOISTURE NEAR THE H7 LEVEL NORTHWARD. THEREFORE WHILE SOME DEEPER
CONVECTION PERCOLATES ALONG THE MARICOPA/GILA COUNTY LINE...RADAR
RETURNS ACROSS THE REGION ARE VERY QUIET...AND POPS WERE REDUCED
SOMEWHAT OVERNIGHT.
MEANWHILE...LATEST WV IMAGERY SHOWS A WELL-DEFINED PVD ACROSS CNTRL
CHIHUAHUA CONTINUING TO MOVE TOWARDS SE AZ. THE LEADING EDGE OF
DIVERGENT FLOW ALOFT AND LARGER SCALE ASCENT WAS JUST BEGINNING TO
MOVE INTO THE SERN PART OF THE STATE...WITH THE BULK OF ENERGY
FORCING A MODEST CONVECTIVE SYSTEM THROUGH SRN SONORA. THIS
EVOLUTION OF FEATURES SUGGESTS SOME POTENTIAL FOR ACCAS SHOWERS
OVERNIGHT THROUGH CNTRL ARIZONA (AS SUPPORTED BY NAM FORECAST BUFR
SOUNDINGS)...HOWEVER HRRR TRENDS HAVE BEEN SHOWING MIXED SIGNALS AND
MORE OFTEN NEGATIVE FOR RAINFALL THAN POSITIVE. THEREFORE...COULD
NOT COMPLETELY REMOVE POPS...AND IT STILL WOULD NOT BE OUT OF THE
REALM OF POSSIBILITY TO SEEING SOME ISOLD/SCT SHOWERS OVERNIGHT.
OTHERWISE...RATHER EXTENSIVE CLOUD COVER WAS HOLDING TEMPERATURES UP
WARMER THAN PREVIOUSLY FORECAST THROUGH THE EASTERN HALF OF THE
FORECAST AREA. THERE ARE SOME UPSTREAM BREAKS IN CLOUDS...AND
FORECAST LOWS WERE ALREADY GUIDED TO SLIGHTLY ABOVE PERSISTENCE...SO
ONLY MINOR MODIFICATIONS WERE NECESSARY.
&&
.PREVIOUS DISCUSSION...
/254 PM MST MON AUG 10 2015/
IT NOW APPEARS THAT TUESDAY WILL LIKELY BE THE MOST ACTIVE DAY...AS
THE FLOW ALOFT BECOMES SOUTHERLY THROUGH THE WHOLE COLUMN WITH LESS
CLOUDINESS LIKELY ON TUESDAY MORNING. DECENT MID-LEVEL SHEAR WILL
PERHAPS ENHANCE THE THUNDERSTORM INTENSIFY/COVERAGE..WITH AT LEAST
SOME STORM ACTIVITY WORKING ITS WAY INTO SW AZ.
WEDNESDAY THROUGH SATURDAY...
IT IS INCREASINGLY LIKELY THAT WE WILL SEE SOME VERY HOT
TEMPERATURES DURING THIS PERIOD AS THE MAIN LONG-WAVE PATTERN RE-
ADJUSTS ITSELF OVER NORTH AMERICA. RATHER DEEP TROFING WILL DROP
INTO THE GREAT LAKES/NE US...AND THE MAIN UPPER RIDGE AXIS FORCED
WESTWARD OVER THE DESERT SW. EVEN THOUGH OUR MID/UPPER-LEVEL FLOW
WILL REMAIN MAINLY FROM A SE-LY DIRECTION DURING THIS PERIOD...WHICH
NORMALLY IS THE BEST DIRECTION FOR MONSOON MOISTURE TO BE IMPORTED
INTO THE REGION...THE UPPER HIGH CENTER BUILDING OVER OUR REGION
WILL BE QUITE STRONG (500MB HEIGHTS RISING INTO THE 596-598DM
RANGE). THIS UPPER HIGH CENTER...WHICH HAS BEEN CENTERED OVER THE
GULF COAST REGION THE LAST FEW DAYS...HAS BROUGHT THAT REGION VERY
HOT AND DRY CONDITIONS...WITH HIGHS APPROACHING OR EXCEEDING 100
DEGREES AT MANY LOCATIONS...INCLUDING HOUSTON AND NEW ORLEANS.
STRONG SUBSIDENCE ALOFT HAS COMPLETELY SHUT DOWN THE CONVECTION THAT
NORMALLY KEEPS HIGHS IN THE LOW-MID 90S AT THESE COASTAL
LOCATIONS...AND IT APPEARS THAT THIS SUBSIDENCE IS HEADED OUR
WAY...AS INDICATED ON THE LATEST FORECAST SOUNDINGS. THUS...IT
APPEARS THAT THUNDERSTORM ACTIVITY WILL BE NOTICEABLY REDUCED DURING
THIS PERIOD...WITH MOST ACTIVITY BEING CONFINED TO THE HIGHER
TERRAIN OF SOUTH-CENTRAL AND SW AZ. THIS LACK OF CONVECTIVE
ACTIVITY/INCREASED SUNSHINE ALONG WITH VERY WARM AIR ALOFT (500MB
TEMPS IN THE -3C TO -4C RANGE) WILL ALLOW TEMPERATURES TO RISE WELL
ABOVE NORMAL...WITH WIDESPREAD READINGS IN THE 110-115F RANGE ACROSS
THE LOWER DESERTS. THESE VERY HOT DAYS ALONG WITH NIGHTTIME LOWS
NEAR 90 AT THE WARMER URBAN LOCATIONS MAKES THE ISSUANCE OF HEAT
RELATED PRODUCTS LATER THIS WEEK VERY LIKELY...ESPECIALLY FOR THE
THU-FRI TIME PERIOD.
SUNDAY AND MONDAY...
ALTHOUGH SOME MODEL DISAGREEMENT DOES CROP UP DURING THIS
PERIOD...IT APPEARS LIKELY THAT THE RIDGING OVER THE DESERT SOUTHWEST
WILL BEGIN TO WEAKEN...WITH COOLER TEMPERATURES AND A BETTER CHANCE
FOR THUNDERSTORMS RETURNING TO THE REGION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
FAR LESS SHRA ACTIVITY MONDAY EVENING WITH JUST THICKER HIGH CLOUDS
AND SLY SFC WINDS EVENTUALLY TURNING TO EASTERLY OVERNIGHT. THERE
STILL COULD BE ISOLD/SCT -SHRA OVERNIGHT...THOUGH CONFIDENCE AND
PROPOSED COVERAGE DOES NOT WARRANT A TAF MENTION. ORIGINALLY HAD A
VALID VCSH TAF GROUPING...HOWEVER WILL LIKELY REMOVE THIS MENTION IN
06Z ISSUANCE.
POTENTIALLY A HIGH IMPACT AVIATION PERIOD LATE TUESDAY AFTERNOON AND
EARLY EVENING AS ORGANIZED THUNDERSTORMS ARE LIKELY OVER PARTS OF
CNTRL AND SRN ARIZONA. CONFIDENCE IS MODERATE ON TIMING AND
PLACEMENT OF HIGHEST IMPACTS...WITH BETTER POTENTIAL FOR STORMS TO
MOVE TOWARDS THE WESTERN PARTS OF THE PHOENIX METRO VERSUS THE EAST.
BEST MODEL OUTPUT SUGGESTS GOOD POTENTIAL FOR STRONG GUSTY OUTFLOW
WINDS AND BLOWING DUST IMPACTING SOME OR ALL OF THE PHOENIX TERMINAL
SITES.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
GOOD CONFIDENCE OF ONLY HIGH CLOUDS OVER SERN CALIFORNIA SITES
THROUGH TUESDAY EVENING...WITH TSRA REMAINING EAST OVER ARIZONA. SFC
WINDS WILL FAVOR A SOUTHERLY DIRECTION...AND EVEN KIPL HAS NOT SEEN
THE TYPICAL WESTERLY SUNDOWNER WIND THIS EVENING (ALTHOUGH THERE
STILL MAY BE A PERIOD OF VARIABLE WINDS TOWARDS SUNRISE).
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AND MUCH WARMER AIR WILL BE DRAWN INTO THE REGION FROM THE
EAST...RESULTING IN A DECREASE OF STORM CHANCES AND HUMIDITIES AND
AN INCREASE IN HIGH TEMPERATURES. WINDS WILL FOLLOW TYPICAL DIURNAL
AND DRAINAGE DRIVEN TRENDS WITH SOME ELEVATED UPSLOPE GUSTINESS IN
THE AFTERNOONS. MORE PRONOUNCED AND MOIST EASTERLY FLOW WILL RETURN
TO THE AREA BY THE LATE WEEKEND AND SHOULD WORK ON THE VERY WARM
TEMPERATURES WILL BOOSTING DAYTIME HUMIDITIES BY SUNDAY INTO MONDAY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO/HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...MO
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
357 AM MDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM MDT TUE AUG 11 2015
CHANCES FOR HEAVY RAIN THE MAIN CONCERN FOR TODAY...WITH PLENTY OF
MOISTURE REMAINING OVR THE FORECAST AREA. FORECAST MODELS ARE NOT IN
GOOD AGREEMENT AS TO WHERE THE POTENTIAL HEAVY RAIN BULLSEYES MAY BE
TODAY. THE NAM SHOWS A DISTURBANCE LIFTING NORTHWARD ACRS THE AREA
THIS MORNING AND SHOWS A BAND OF HEAVIER PCPN WORKING NORTHWARD WITH
THE DISTURBANCE. HOWEVER...THE NAM IS CURRENTLY NOT VERIFYING WELL
AS IT SHOW FAIRLY WIDESPREAD PCPN ACRS THE AREA BETWEEN 06Z AND 12Z
AND SO FAR THIS IS NOT HAPPENING. IN THE AFTERNOON HOURS THE NAM
HAS THE BEST CHANCES FOR PCPN OVR THE ERN PLAINS AND NORTHERN
PORTIONS OF THE CWA. WITH EAST TO SOUTHEAST UPSLOPE OVR EL PASO
COUNTY THRU THE DAY AND GOOD CHANCES FOR PCPN...ESPECIALLY THIS
EVENING...LOCALLY HEAVY RAINFALL AND FLASH FLOODING WL BE A
CONCERN...ESPECIALLY BECAUSE MUCH OF EL PASO COUNTY HAS HAD
SIGNIFICANT PCPN AMOUNTS IN THE LAST DAY AND A HALF RESULTING IN
SATURATED SOILS WHICH WL RESULT IN A LOT OF RUNOFF IF THE RAIN IS
HEAVY. THE NSSL 4KM WRF IS SIMILAR TO THE NAM...SHOWING HAVING PCPN
ACRS PORTIONS OF THE SERN PLAINS EARLY THIS MORNING...BUT THEN SHOWS
DECREASING PCPN CHANCES BY LATE MORNING. IT THEN HAS SCT PCPN FOR
THE AFTERNOON AND EVENING HOURS WITH LOCALIZED AREAS OF HEAVY RAIN.
THE HRRR DOES NOT SHOW THE SAME KIND OF HEAVY RAIN BAND MOVING NORTH
ACRS THE FORECAST AREA THIS MORNING LIKE THE NAM SHOWS. EXCEPT OVR
THE FAR ERN AREAS WHERE IT SHOWS WIDESPREAD PCPN UNTIL LATE MORNING.
CURRENT RADAR IMAGES SHOW PCPN WORKING ITS WAY NORTH INTO THE SERN
CORNER OF CO...WITH WIDESPREAD PCPN ALSO MOVING INTO THE SW MTNS.
FOR NOW WL MAINLY BROADBRUSH MUCH OF THE AREA WITH SCT POPS...EXCEPT
FOR SOME HIGHER POPS OVR PORTIONS OF THE HYR TRRN.
BY LATE TONIGHT...PCPN WL BE ON THE DECREASE ALTHOUGH AT LEAST SCT
PCPN SHOULD CONTINUE ALONG MUCH OF THE CONTDVD. SOME ISOLD
SHOWERS/TSTMS SHOULD ALSO CONTINUE MUCH OF THE NIGHT OVR THE FAR
SERN PLAINS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 357 AM MDT TUE AUG 11 2015
WEDNESDAY-FRIDAY...A BROAD UPPER HIGH CENTERED ACROSS NORTHEASTERN
NEW MEXICO AND NORTHWESTERN TEXAS EARLY WEDNESDAY IS PROGGED TO
BUILD SLOWLY NORTH AND WEST ACROSS THE CENTRAL ROCKIES AND INTO THE
FOUR CORNERS REGION THROUGH THE END OF THE WORK WEEK. THIS WILL
ALLOW FOR A GRADUAL LESSENING OF AFTERNOON AND EVENING STORMS ACROSS
THE AREA...AS THE MONSOONAL MOISTURE PLUME IS SHUNTED NORTH AND WEST
OF THE AREA...ALONG WITH WARMING TEMPERATURES ALOFT UNDER THE
BUILDING RIDGE HELPING TO SUPPRESS CONVECTION. BEST COVERAGE OF
STORMS THROUGH THE PERIOD LOOKS TO BE ACROSS THE CENTRAL MOUNTAINS
THROUGH THE PIKES PEAK REGION WITH A FEW STORMS DRIFTING OFF THE
HIGHER TERRAIN ACROSS THE IMMEDIATE ADJACENT PLAINS. THERE STILL
WILL BE ENOUGH MOISTURE...COMBINED WITH SLOW STORM MOVEMENT...TO
KEEP THE POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS THE AREA.
SHOULD ALSO SEE TEMPERATURES WARMING BACK TO ABOVE SEASONAL AVERAGES
THROUGH THE PERIOD...WITH THE WARMING ALOFT AND LESS EXPECTED
COVERAGE OF STORMS.
SATURDAY-MONDAY...UPPER HIGH GETS SHUNTED SOUTH AND WEST ACROSS THE
DESERT SOUTHWEST...AS SEVERAL EMBEDDED SHORT WAVES TRANSLATE THROUGH
THE FASTER ZONAL FLOW ALOFT ACROSS THE NORTHERN TIER OF STATES. ONE
WAVE LOOKS TO SEND A COLD FRONT ACROSS THE EASTERN PLAINS SATURDAY
NIGHT WHICH WILL ALLOW FOR BETTER COVERAGE OF STORMS...ESPECIALLY
OVER AND NEAR THE EASTERN MOUNTAINS...AS LOW LEVEL MOISTURE
INCREASES WITHIN EASTERLY UPSLOPE FLOW. WITH MORE MOISTURE AND
SLIGHTLY COOLER AIR ALOFT...SHOULD SEE TEMPERATURES COOLING BACK TO
AROUND SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 357 AM MDT TUE AUG 11 2015
VFR CONDITIONS ARE GENERALLY EXPECTED AT THE TAF SITES TODAY AND
THROUGH THE EVENING...HOWEVER SHOWERS AND TSTMS WL BE POSSIBLE IN
THE VCNTY OF TAF SITES TODAY AND THIS EVENING WHICH COULD AT TIMES
RESULT IN BRIEF MVFR CONDITIONS IN HEAVY RAIN. LATE TONIGHT THERE WL
BE THE POTENTIAL FOR LOW STRATUS AND FOG AT KCOS AND KPUB AS
INDICATED BY MOS GUIDANCE AND BUFKIT SOUNDINGS...WITH MVFR OR IFR
CONDITIONS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1101 PM MDT MON AUG 10 2015
.UPDATE...
ISSUED AT 840 PM MDT MON AUG 10 2015
MCS LOCATED IN PUEBLO AND CROWLEY COUNTIES WILL CONTINUE TO
SLOWLY MOVE OFF TO THE ESE OVER THE NEXT FEW HOURS AS DEEP LOW
LEVEL MOISTURE AND LOW LEVEL MOISTURE CONVERGENCE HELP FUEL THE
STORM SYSTEM. RAISED POPS ACROSS CENTRAL AND SAN JUANS MTNS AS 00Z
NAM TRENDED TOWARDS ENHANCED ACTIVITY OVERNIGHT ACROSS THE HIGHER
TERRAIN. OTHERWISE CURRENT FORECAST REMAINS ON TRACK. LUKINBEAL
UPDATE ISSUED AT 537 PM MDT MON AUG 10 2015
THE THREAT OF FLASH FLOODING WILL CONTINUE ACROSS THE I-25
CORRIDOR THROUGH THE LATE EVENING HOURS AS A LINE OF TSRA
CURRENTLY EXTENDS FROM NE EL PASO COUNTY THROUGH WESTERN FREMONT
COUNTY WILL SLOWLY MOVE ESE OVER THE NEXT SEVERAL HOURS. LOW LEVEL
CONVERGENCE ALONG TWO OUTFLOW BOUNDARIES IN FAR SE EL PASO COUNTY
MAY INTENSIFY ACTIVITY FURTHER ALONG THE TSRA LINE. LATEST RUNS OF
THE HRRR CONTINUE TO BRING MODERATE TO HEAVY RAINFALL INTO EL
PASO...PUEBLO...CROWLEY...AND OTERO COUNTIES BETWEEN 01-06Z
TONIGHT. DEEP MOISTURE IS IN PLACE ACROSS THE PLAINS WITH PWATS
RANGING FROM 1.2-1.6 INCHES WITH DEW POINTS IN THE LOW 60S. WARM
RAIN PROCESSES IN THE LOWEST 100 MB WILL CONTINUE TO PROMOTE THE
DEVELOPMENT OF HEAVY RAINFALL THROUGH 06Z THIS EVENING ACROSS THE
PLAINS. ANOTHER POTENTIAL AREA OF CONCERN OVERNIGHT WILL BE THE
SAN LUIS VALLEY...SAN JUANS...AND CENTRAL MTNS WHERE AN UPPER
LEVEL DISTURBANCE IN COMBINATION WITH HIGH LOW-MID LEVEL MOISTURE
WILL PRODUCE SCATTERED TO NUMEROUS SHOWERS WITH THE POTENTIAL TO
PRODUCE HEAVY RAINFALL. RAINFALL RATES WILL DECREASE AFTER 06Z AS
CLOUD TOPS LOWER ACROSS THE CWA DUE TO UPPER LEVEL SUBSIDENCE
MOVING OVERHEAD...DIMINISHING THE POTENTIAL FOR FLASH FLOODING.
LUKINBEAL
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
TSRA MOST NUMEROUS THIS AFTERNOON OVER THE PLAINS SOUTH OF THE
ARKANSAS RIVER...THOUGH AN ISOLATED CELL OVER TELLER AND EL PASO
COUNTIES EARLIER IN THE DAY MANAGED TO PRODUCE FLASH FLOODING OVER
WESTERN PORTIONS OF COLORADO SPRINGS AND THE EASTERN EDGE OF THE
WALDO CANYON BURN SCAR. MAIN QUESTION FOR TONIGHT WILL REVOLVE
AROUND LOCATION OF HEAVIER RAINFALL AND HOW LATE WILL STORMS
PERSIST INTO TUE MORNING. 19Z/20Z RUNS OF THE HRRR BRING ANOTHER
WAVE OF TSRA AND HEAVY RAIN THROUGH EL PASO COUNTY 00Z-02Z...THEN
ACROSS PUEBLO COUNTY AND NORTHERN PORTIONS OF THE ARKANSAS VALLEY
02Z-05Z. 12Z VERSIONS OF THE NAM/NAM 4KM/NSSL WRF ON THE OTHER
HAND...KEEP HEAVIEST RAINFALL MAINLY OVER THE MOUNTAINS
OVERNIGHT...WITH FOCUS FOR MOST TSRA SHIFTING TOWARD THE SAN JUAN
MOUNTAINS AFTER 06Z AS AREA OF DEEP TROPICAL MOISTURE OVER THE 4
CORNERS ROTATES NORTHEASTWARD. FORECAST LEANS A LITTLE TOWARD THE
HRRR...AS LAPS CAPES ARE STILL ABOVE 1000 J/KG OVER THE EASTERN
MOUNTAINS AND I-25 CORRIDOR...SUGGESTING ANOTHER BOUT OF TSRA IS
POSSIBLE. CONSIDERED A FLASH FLOOD WATCH FOR EL PASO COUNTY FOR
THIS EVENING AS HEAVY RAIN HAS FALLEN ACROSS THE REGION...THOUGH
WITH HRRR SHIFTING AXIS OF STRONGER STORMS SOUTH FAIRLY
QUICKLY...WILL REFRAIN FROM ISSUANCE AT THIS POINT. POCKETS OF
HEAVY RAIN LOOK POSSIBLE FARTHER SOUTH OVER THE PLAINS...BUT MOST
AREAS HAVE BEEN DRY ENOUGH LATELY TO TAKE AT LEAST A COUPLE HOURS
OF HEAVER PRECIP. PRECIP SLOWLY WANES OVERNIGHT...BUT NEVER
COMPLETELY COMES TO AN END...SO WILL KEEP SOME POPS GOING MANY
AREAS INTO EARLY TUE MORNING.
ON TUE...MOISTURE REMAINS IN PLACE...THOUGH HEIGHTS BEGIN TO BUILD
SLIGHTLY AS UPPER HIGH STARTS ITS NORTHWARD EXPANSION. STILL
APPEARS MOST LOCATIONS WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE AGAIN...THOUGH EXTENT OF OVERNIGHT CONVECTION
AND POTENTIAL MCS OVER THE EASTERN PLAINS/NORTHEASTERN NM WILL
LIKELY PLAY A ROLE IN AMOUNT OF CONVECTIVE COVERAGE...ESPECIALLY
OVER THE PLAINS WHERE EARLY MORNING SHOWERS COULD LIMIT
INSTABILITY. BROAD- BRUSH OF SCATTERED POPS LOOKS FINE...AND WITH
MOISTURE LEVELS REMAINING RELATIVELY HIGH...LOCALLY HEAVY RAINFALL
WILL AGAIN BE POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
UPPER RIDGE EXPANDS NORTHWARD WED-FRI...WITH THE UPPER LEVEL HIGH
PRESSURE CENTER REMAINING ALONG THE CO/NM BORDER THROUGH THE
PERIOD. TRAPPED MOISTURE UNDER THE HIGH WILL CONTINUE TO BE
RECYCLED...WITH DAILY AFTERNOON/EVENING TSRA OVER THE
MOUNTAINS...THOUGH COVERAGE MAY BECOME RATHER SPARSE WED/THU AS
TEMPERATURES ALOFT WARM. PLAINS/VALLEY TSRA CHANCES LOOK FAIRLY
LOW...THOUGH TOUGH TO RULE OUT A COUPLE STORMS DRIFTING AWAY FROM
THE MOUNTAINS EACH DAY...ESPECIALLY ALONG AND WEST OF I-25.
FORECAST HAS LOW POPS FOR ALL AREAS EACH DAY WED-FRI...WHICH MAY
BE A LITTLE OVERDONE...BUT WILL RUN WITH FOR NOW. RIDGE FLATTENS
SLIGHTLY FRI INTO THE WEEKEND...WHILE WEAK FRONT OOZES INTO THE
EASTERN PLAINS LATE SUN. EXPECT A GRADUAL INCREASE IN TSRA CHANCE
MOST LOCATIONS AS SLIGHTLY DEEPER MOISTURE MOVES IN FROM THE
WEST...WHILE LOW LEVELS ON THE PLAINS MOISTEN AND WESTERLY STEERING
CURRENTS BECOME MORE FAVORABLE FOR STORMS TO MOVE ONTO THE PLAINS.
TEMPS FROM WED INTO THE WEEKEND WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1045 PM MDT MON AUG 10 2015
MONSOON DISTURBANCE WILL CONTINUE TO TRACK ACROSS FLIGHT
AREA TONIGHT...WITH SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS CONTINUING ACROSS THE FLIGHT AREA. ANOTHER
MONSOON DISTURBANCE WILL MOVE ACROSS THE FLIGHT AREA
TUESDAY AFTERNOON AND EVENING. CONDITIONS WILL GENERALLY
BE VFR OUTSIDE OF PRECIPITATION AND MVFR INSIDE OF
PRECIPITATION. HOWEVER...LOCAL IFR/LIFR CONDITIONS WILL
BE POSSIBLE IN AREAS OF MORE INTENSE PRECIPITATION. THIS
INCLUDES THE KCOS...KPUB AND KALS TAF SITES THROUGH 06Z
TUESDAY NIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/LW
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...LW
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
527 AM EDT TUE AUG 11 2015
.SYNOPSIS...
09Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THAT A SIGNIFICANT UPPER
LEVEL PATTERN AMPLIFICATION EXPECTED FOR THE MIDDLE PORTION OF THE
WEEK HAS ALREADY BEGUN. IMPRESSIVE LONGWAVE RIDGING NOW EXTENDS
FROM THE SOUTHERN PLAINS NORTHWARD THROUGH THE INTER-MOUNTAIN WEST
INTO SOUTH-CENTRAL CANADA. DOWNSTREAM LONGWAVE TROUGHING HAS NOW
DUG INTO THE GREAT LAKES/OHIO VALLEY...AND IS FORECAST BY GUIDANCE
ENSEMBLES TO CONTINUE AMPLIFYING DOWN INTO THE SOUTHEASTERN CONUS
DURING THE NEXT 24-36 HOURS. CURRENTLY OUR FORECAST AREA IS UNDER
WEAK RIDGING IN THE MID-LEVELS THAT WILL BE DECAYING THROUGH THE
NEXT 24 HOURS. IN FACT...LOOKING UP THROUGH THE COLUMN...THERE IS
VERY LITTLE FLOW UNTIL YOU GET ABOVE 400MB WHERE A DEFINED
NORTHEASTERLY WIND IS FINALLY ENCOUNTERED. THIS LIGHT FLOW THROUGH
MUCH OF THE COLUMN WILL RESULT IN A SLOW STORM MOTION FOR THE
THUNDERSTORMS THAT DO DEVELOP LATER TODAY.
AT THE SURFACE...
THE GRADIENT IS QUITE WEAK ACROSS THE FL PENINSULA AND EASTERN
GULF OF MEXICO...WITH THE NOSE OF THE SUBTROPICAL RIDGE JUST
SLIGHTLY WORKING INTO SOUTH FLORIDA. THE RESULTING WIND PATTERN IS
LIGHT FROM THE SOUTH OR SOUTHEAST...BUT WILL BECOME MORE WESTERLY
WITH TIME TODAY...ESPECIALLY WITH THE DEVELOPMENT OF WEAK SEA-
BREEZE CIRCULATIONS.
SKIES ARE PARTLY TO MOSTLY CLEAR EARLY THIS MORNING...AND SHOULD
SEE PLENTY OF SUNSHINE TO START OUT THE DAY BEFORE A SCT-BKN
CUMULUS FIELD BECOMES ESTABLISHED LATER THIS MORNING/EARLY
AFTERNOON. LOCALIZED LAND BREEZE CONVERGENCE IS HELPING FOCUS A
FEW WIDELY SCT SHOWERS OFF THE COAST OF LEE/CHARLOTTE COUNTIES.
MAY SEE ONE OR TWO OF THESE CELLS IMPACT THE IMMEDIATE COAST
DURING THE FIRST COUPLE OF DAYLIGHT HOURS...BUT OTHERWISE...THE
REMAINDER OF THE AREA WILL BE DRY THROUGH MUCH IF NOT ALL OF THE
MORNING HOURS.
&&
.SHORT TERM...
TODAY...
THE SYNOPTIC PATTERN TODAY SUGGEST A FORECAST TYPICAL OF A LIGHT
WEST/SW FLOW REGIME IN THE SUMMER. A FEW WIDELY SCT SHOWERS/STORMS
DEVELOPING NEAR THE COAST DURING MIDDAY WITH THE ONSET OF THE
SEA-BREEZE FOLLOWED BY A SLOW MIGRATION AND EXPANSION OF THE
STORMS INLAND AS THE AFTERNOON PROGRESSES. AFTER 19-20Z...MOST OF
THE HIRES CONVECTION ALLOWING GUIDANCE HAVE THE MAJORITY OF STORMS
INLAND FROM I-75...WITH VERY LITTLE ACTIVITY AT THE BEACHES. THIS
MAKES SINCE WITH THE SEA-BREEZE FOCUS MOVING INLAND AND THE
STABILIZING POST ENVIRONMENT MOVING ONSHORE. SOME DRIER AIR IN THE
MID-LEVELS MAY HOLD BACK CONVECTION A BIT ALONG AND NORTH OF THE
I-4 CORRIDOR...SO HAVE HIGHEST POPS (55-65% COVERAGE) ACROSS
SOUTHERN POLK/HIGHLANDS/HARDEE/DESOTO EARLY THIS EVENING.
TONIGHT...EVENING STORMS (MAINLY OVER SOUTH-CENTRAL INTERIOR
ZONES) DISSIPATE WITHIN A FEW HOURS OF SUNSET AND SET UP A MOSTLY
DRY AND SEASONABLE OVERNIGHT...AT LEAST FOR A WHILE. ALOFT...THE
UPPER RIDGE WILL HAVE COMPLETELY BROKEN DOWN WITH THE EASTERN
CONUS TROUGH DIGGING SOUTHWARD OVER THE NORTHERN/CENTRAL
PENINSULA. AT THE SURFACE..AN ASSOCIATED FRONTAL BOUNDARY WILL BE
APPROACHING THE I-10 CORRIDOR. THE DEVELOPING GRADIENT AHEAD OF
THE FRONT WILL RESULT IN A MORE WELL-DEFINED WESTERLY FLOW INTO
THE WEST-CENTRAL FL COAST UP THROUGH THE NATURE COAST LATE AT
NIGHT. THIS FLOW IS ALREADY FAVORED FOR LATE NIGHT/EARLY MORNING
SHOWER DEVELOPMENT...BUT ADD IN THE WEAK SYNOPTIC SUPPORT FOR
ASCENT ALOFT...AND WOULD CERTAINLY EXPECT TO SEE SCT
SHOWERS/STORMS DEVELOPING OVER THE COASTAL WATERS AND MIGRATING
TOWARD SHORE BEFORE DAWN. WILL HAVE A 30% CHANCE POP NORTH OF
TAMPA BAY AFTER 09Z FOR THIS CONVECTION...HOWEVER...COULD SEE THIS
COVERAGE ACTUALLY VERIFY A BIT LOW GIVEN THE SYNOPTIC SUPPORT.
WEDNESDAY...
SURFACE BOUNDARY STALLS NEAR THE I-10 CORRIDOR...WITH WEAK...BUT
DEEP LAYER CYCLONIC FLOW ALOFT OVER THE NORTHERN HALF OF THE
AREA. LIKELY TO BE DEALING WITH ON AND OFF SHOWERS/STORMS NORTH
OF TAMPA DURING THE MORNING/EARLY AFTERNOON...WITH PERHAPS A BIT
OF A SLOWDOWN IN SHOWER DEVELOPMENT LATER IN THE DAY...OR AT LEAST
A MIGRATION OF THE BEST SHOWER COVERAGE INLAND TO COINCIDE WITH
THE DIURNAL HEATING. SOUTH OF THE I-4 CORRIDOR...THE PATTERN WILL
STILL MORE RESEMBLE A TYPICAL SUMMER DAY UNDER WESTERLY FLOW. FEW
SHOWER/STORMS AT THE COAST DURING THE MORNING...WITH A MORE
DEFINED SEA-BREEZE TRACKING INLAND AND TAKING THE BEST STORM
COVERAGE WITH IT BY THE MIDDLE/LATER PART OF THE AFTERNOON.
BETTER CHANCES FOR MORE ORGANIZED RAINFALL DEVELOP ALONG THE WEAK
FRONTAL BOUNDARY WEDNESDAY NIGHT INTO THURSDAY. MORE ON THIS
POTENTIAL IN THE LONG TERM DISCUSSION BELOW.
&&
.LONG TERM...
.LONG TERM /THURSDAY-MONDAY/...
A TROUGH CONTINUES TO HOLD OVER THE EASTERN SEABOARD OF THE UNITED
STATES THURSDAY INTO THE WEEKEND. THE SURFACE FRONTAL BOUNDARY MOVES
ONTO THE PENINSULA OF FLORIDA LATE WEDNESDAY INTO
THURSDAY...SETTLING AROUND THE INTERSTATE 4 CORRIDOR ACCORDING TO
SOLUTIONS PROVIDED BY BOTH THE 00Z GFS AND 00Z ECMWF. THE SURFACE
BOUNDARY WILL MEANDER ACROSS THE REGION OVER THE WEEKEND BEFORE
SLOWLY RETREATING NORTHWARD EARLY NEXT WEEK.
THIS PATTERN WILL CREATE THE POTENTIAL FOR ADDITIONAL HEAVY RAINFALL
AS PLENTY OF MOISTURE AND UPPER LEVEL SUPPORT WILL BE AVAILABLE. THE
DIFFERENCES BETWEEN THE GFS AND ECMWF ARE SURPRISINGLY MINIMAL EVEN
INTO EARLY NEXT WEEK. THEY DO START DIVERGING BEYOND THE FORECAST
PERIOD...BUT IT HAS MINIMAL AFFECT ON THE FORECAST. THE GENERAL
CONSENSUS BETWEEN GUIDANCE SOLUTIONS RAISES FORECAST
CONFIDENCE...BUT TRYING TO FORECAST THE TIMING AND LOCATION OF A
FRONTAL BOUNDARY IS STILL A CHALLENGE IN THE EXTENDED. THOSE WHO
HOLD INTERESTS ALONG AREA RIVERS OR LOW-LYING FLOOD-PRONE AREAS
...PARTICULARLY THOSE SATURATED AREAS THAT HAVE SUFFERED RECENT
FLOODING...SHOULD MONITOR THE EVOLUTION OF THE FORECAST OVER THE
COMING DAYS.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA
EARLY THIS MORNING. WE ARE EXPECTING SCT STORM DEVELOPMENT FROM
MIDDAY INTO THE EARLY AFTERNOON ALONG THE I-75 CORRIDOR AROUND THE
TERMINALS...BUT ALSO EXPECT MUCH OF THE CONVECTION TO MOVE INLAND
FROM THE FORECAST SITES BY 20-21Z.
&&
.MARINE...
A LIGHT GRADIENT WILL PERSIST ACROSS THE EASTERN GULF OF MEXICO
THROUGH TODAY...FOLLOWED BY THE APPROACH OF A FRONTAL SYSTEM FROM
THE NORTH LATER TODAY INTO THURSDAY. THE FRONT WILL STALL OVER THE
NORTHEAST GULF INTO EARLY FRIDAY AND THEN DISSIPATE. A WEAK
GRADIENT WILL AGAIN DEVELOP OVER THE FORECAST WATERS FOR THE
UPCOMING WEEKEND. SHOWERS AND THUNDERSTORMS WILL BE ENHANCED OVER
THE FORECAST WATERS AHEAD OF THE FRONT LATER WEDNESDAY INTO
THURSDAY...ESPECIALLY FROM TAMPA BAY NORTHWARD.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS ARE EXPECTED THROUGH THE NEXT SEVERAL
DAYS HAS ABUNDANT LOW LEVEL MOISTURE KEEPS RELATIVE HUMIDITY
LEVELS WELL ABOVE CRITICAL VALUES. SHOWERS AND STORMS WILL
BECOME NUMEROUS IN NATURE OVER THE NORTHERN AND INTERIOR PORTIONS
OF THE AREA WEDNESDAY INTO THURSDAY AS A FRONTAL BOUNDARY
APPROACHES AND STALLS OVER THE NORTHERN PART OF THE STATE.
FOG POTENTIAL...NO SIGNIFICANT FOG IS EXPECTED FOR THE NEXT
SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 79 91 78 / 20 10 40 50
FMY 91 76 92 77 / 50 10 40 40
GIF 93 75 93 76 / 50 40 50 50
SRQ 89 78 89 78 / 30 20 30 50
BKV 93 73 91 74 / 20 20 50 50
SPG 91 79 90 79 / 20 20 40 60
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...14/MROCZKA
LONG TERM...02/GARCIA
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
358 AM EDT TUE AUG 11 2015
.DISCUSSION...
...LOCALLY HEAVY RAINS POSSIBLE LATER THIS WEEK...
TODAY-TONIGHT...
REMNANT TROF ASSOCIATED WITH THE RECENT FRONTAL BNDRY HAS DRIFTED
BACK INTO CENTRAL FL JUST S OF THE I-4 CORRIDOR. THE ATLC RIDGE
AXIS HAS RETURNING AS THE DOMINANT WX FEATURE FOR THE REGION...THOUGH
THE POSITION OF THE TROF IS KEEPING IS SOMEWHAT DISORGANIZED. EVNG
RAOBS SHOW PWAT VALUES BTWN 1.5"-1.7" OVER CNTRL/N FL...INCREASING
TO 2.2" OVER S FL. RAP ANALYSIS BACKING THIS UP WITH H100-H70 MEAN
RH VALUES BTWN 70-80PCT S OF THE TROF AXIS...BUT STILL LINGERING
BTWN 60-70PCT N OF THE AXIS. SUBSTANTIAL MID LVL DRY AIR REMAINS
IN PLACE OVER MOST OF THE CWA WITH H85-H50 MEAN RH BTWN 40-50PCT.
WARM MID LVLS REMAIN IN PLACE WITH H70 TEMPS BTWN 9-10C...H50 TEMPS
BTWN -5/-6C...YIELDING LAPSE RATES ARND 5.5C/KM THRU THE LYR.
DYNAMICALLY SPEAKING...THE POSITION OF THE TROF HAS ALLOWED A LCL
MID LVL VORT MAX TO DVLP N OF THE BAHAMAS...BUT THE WIND FIELD IS
NOT STRONG ENOUGH TO ADVECT THIS ENERGY ONSHORE IN ANY LARGE SCALE
MANNER. UPR LVLS ARE NEUTRAL AT BEST DUE TO A DEPARTING 40-50KT
NERLY JET STREAK OVER THE GOMEX.
DIURNAL CONVECTION WILL INCREASE AS THE DRY AIR ALOFT SLOWLY
MODIFIES. PGRAD THRU THE H100-H50 LYR WILL BE QUITE WEAK WITH MEAN
W/SWRLY FLOW BLO 10KTS. AN EAST COAST SEA BREEZE WILL DVLP BY
MIDDAY...LCL MOS GUIDANCE INDICATING FORMATION BTWN 16Z- 17Z AND
PUSHING INLAND TO BTWN THE KISSIMMEE/ST. JOHNS RIVER BASINS ARND
21Z. WEAK DYNAMIC/THERMODYNAMIC INSTABILITY WILL LIMIT CONVECTIVE
STRENGTH... THOUGH THE WEAK STEERING FLOW WILL INCREASE POTENTIAL
FOR LCL HEAVY PRECIP.
SCT POPS AREAWIDE...INCREASING FROM 30PCT ALNG AND N OF THE I-4
CORRIDOR TO 50PCT ARND LAKE OKEECHOBEE TO ACCOUNT FOR HIGHER
MOISTURE. LACK OF DYNAMIC SUPPORT INDICATES CONVECTION SHOULD BURN
OUT WITHIN AN HR OF SUNSET WITH THE LOSS OF DAYTIME HEATING. MAX
TEMPS IN THE L/M90S... THOUGH A FEW SPOTS ALONG THE IMMEDIATE COAST
MAY HOLD IN THE U80S DEPENDING ON THE TIMING OF THE SEA BREEZE
PASSAGE. SFC DEWPOINTS IN THE L/M70S SUGGEST SIMILAR MIN TEMPS.
WED-THU...A FRONTAL BOUNDARY ALONG THE MID ATLC SEABOARD TO THE
NRN GULF COAST WL NUDGE SWD INTO N FL IN THE FORM OF A TROUGH.
INCRSG RAIN CHCS WL OCCUR AS PATTERN AMPLIFICATION OVER THE CONUS
AND AN ASCD DIGGING UPR WAVE PATTERN OVER THE EASTERN CONUS LOOKS
TO LINGER THROUGH THE REMAINDER OF THE WEEK. SFC TROUGH N OF AREA
WL COMBINE WITH INCRSG MOISTURE AND FAVORABLE STEERING PATTERN TO
RAISE THE LIKELIHOOD OF AFTN SHOWERS AND STORMS ACROSS THE
FORECAST AREA. EXPECT HIGHER RAIN CHCS ESP OVER NORTHERN AND
CENTRAL COUNTIES INTO THE OVERNIGHT PERIOD AS WELL.
LATE WEEK...THE WEAKENING BOUNDARY WI LINGER OVER N FL INTO THE
WEEKEND WITH DEEP LAYERED MOISTURE ACROSS THE REGION TO PRODUCE
NMRS DIURNAL SHOWERS AND SLOW MOVING STORMS. LOCALLY HEAVY RAIN
WILL BE POSSIBLE IN SPOTS BEGINNING THURSDAY AND INTO SATURDAY.
GFS TRIES TO SHOW ADDITIONAL FALLING HGHTS ALOFT WITH WEAK CUTOFF
LOW POSSIBLE OVER THE SE...WHEREAS THE LTST ECMWF KEEPS AN OPEN
WAVE CONFIGURATION. AT ANY RATE...A SLIGHTLY WETTER THAN NORMAL
FORECAST CAN BE ANTICIPATED INTO EARLY NEXT WEEK WITH ONSET OF THE
EXPECTED HIGH AMPLITUDE SYNOPTIC PATTERN.
&&
.AVIATION...THRU 12/12Z
SFC WINDS: THRU 11/14Z...VRBL AOB 3KTS. BTWN 11/14Z-11/16Z...W/SW
6-9KTS. BTWN 11/16Z-11/18Z...BCMG E/SE 8-11KTS BTWN KOMN-KSUA
ASSOCD WITH THE EAST COAST SEA BREEZE. BTWN 11/19Z-11/21Z...BCMG
E/SE 6-9KTS ALNG THE I-4 CORRIDOR. BTWN 12/00Z-12/03Z...BCMG S/SW
3-5KTS.
VSBY/WX/CIGS: BTWN 10/16Z-10/24Z...SCT MVFR SHRAS/ISOLD IFR TSRAS
ALL SITES...S OF KTIX-KISM SLGT CHC LIFR +TSRAS WITH SFC WND G35KTS.
&&
.MARINE...
TODAY-TONIGHT...WEAK SFC TROF OVER CNTRL FL WILL COMBINE WITH A
BROAD RIDGE AXIS OVER S FL/NRN BAHAMAS TO GENERATE A LIGHT TO GENTLE
S/SW BREEZE OVER THE LCL ATLC TODAY...WINDS BCMG E/SE NEAR THE COAST
ARND MIDDAY AS THE EAST COAST SEA BREEZE DVLPS. GENTLE TO MODERATE
SW BREEZE OVERNIGHT AS A NEW FRONTAL BOUNDARY PUSHES INTO THE THE
DEEP SOUTH AND STALLS OVER THE FL PANHANDLE. SEAS AOB 2FT NEARSHORE
AND 2-3FT OFFSHORE.
FAVORABLE BOATING CONDITIONS WL OCCUR DURING THE EXTENDED PERIOD WITH
SEAS AROUND 2 FT OR LESS NEAR SHORE AND 2 TO 3 FT OVER THE OUTER
WATERS. THESE SIMILAR CONDITIONS CAN BE EXPECTED INTO THE WEEKEND
AS WELL WITH AN INCREASE IN STORMS PRODUCING SOME HIGHER WINDS AND
SEAS NEAR THE IMMEDIATE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 90 76 93 74 / 30 20 60 50
MCO 94 76 94 76 / 30 20 60 40
MLB 91 77 92 76 / 30 20 60 40
VRB 91 73 92 73 / 40 20 50 40
LEE 93 77 92 76 / 30 20 60 40
SFB 94 77 94 76 / 30 20 60 50
ORL 94 77 95 77 / 30 20 60 40
FPR 91 73 92 74 / 40 20 50 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
141 AM EDT TUE AUG 11 2015
.SYNOPSIS...
ISSUED AT 715 PM EDT MON AUG 10 2015
THE CHANCES FOR SHOWERS AND A FEW STORMS WILL DIMINISH THROUGH THE
EVENING AS DRIER AIR FILTERS IN FROM THE NORTH. DRY AND LESS HUMID
WEATHER IS THEN EXPECTED THROUGH MID WEEK. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 60S. HIGH TEMPERATURES ON
TUESDAY WILL REACH INTO THE MID TO UPPER 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
LEAD SHORT WAVE WHICH TRACKED ACROSS THE AREA EARLIER TODAY ALLOWED
FOR INITIAL WEAK LAKE ENHANCED SURFACE TROUGH TO SERVE AS FOCUSING
MECHANISM FOR SCATTERED SHOWERS/ISOLATED STORMS. OVER PAST
HOUR...STARTING TO SEE UPSWING IN CONVECTIVE COVERAGE ALONG THIS
BOUNDARY AS A STRONGER UPSTREAM VORT MAX ACROSS NORTHERN ILLINOIS
CONTINUES TO APPROACH THE AREA. A SECONDARY AREA OF
SCATTERED/NUMEROUS SHOWERS/STORMS HAS DEVELOPED ACROSS FAR
SOUTHERN/AND MAINLY SOUTH OF FORECAST AREA ACROSS CENTRAL INDIANA.
THIS AREA APPEARS BE TIED MORE CLOSELY TO ENHANCED LOW LEVEL THETAE
ADVECTION...WHICH ALSO IS COLOCATED WITH MORE PRONOUNCED INSTABILITY
AXIS WITH LATEST RUC ANALYSIS DEPICTING 100 HPA MLCAPES ON THE ORDER
OF 1000-1500 J/KG. MODEST DEEP LAYER SHEAR AND AND WEAK TO MODERATE
INSTABILITY WILL CONTINUE TO POSE SOME THREAT OF ISOLD STRONG STORMS
WITH GUSTY WINDS AS THE MAIN THREAT. WHILE BRIEF VERY HEAVY RAINFALL
IS POSSIBLE...PROPAGATION VECTORS ARE SLIGHTLY MORE PROGRESSIVE THIS
AFTERNOON IN COMPARISON TO LAST EVENING AND CURRENT THINKING IS THAT
WHILE LOCALIZED PONDING OF WATER/MINOR FLOODING IS POSSIBLE WITH THE
STRONGER STORMS...FLASH FLOODING CONCERNS SHOULD BE MINIMAL.
PRIMARY INSTABILITY AXIS SHOULD BEGIN TO ADVECT ACROSS FAR EASTERN
PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON...BUT WEAK
INSTABILITY WILL REMAIN ACROSS ENTIRE FORECAST AREA AS
AFOREMENTIONED NORTHERN ILLINOIS VORT MAX ALLOWS FOR EROSION OF
RELATIVELY 800-700 HPA LAYER NOTED PER EARLIER AMDAR REGIONAL
SOUNDINGS. THIS SHOULD ALLOW FOR ENOUGH LINGERING INSTABILITY WITH
STRONGER ILLINOIS VORT MAX TO KEEP SOME CHANCE OF ISOLD-SCT
CONVECTION ACROSS THE AREA EARLY THIS EVENING. QUIET CONDITIONS
EXPECTED LATER THIS EVENING INTO THE OVERNIGHT AS SECONDARY SFC
TROUGH USHERS IN COOLER AND DRIER LOW LEVEL AIR. QUIET WEATHER
EXPECTED FOR TUESDAY WITH PERSISTENT MID LEVEL SUBSIDENCE...ALTHOUGH
THE NEXT IN SERIES OF UPPER LEVEL SHORT WAVES IS EXPECTED TO DIG
ACROSS THE GREAT LAKES EARLY TUESDAY...WHICH COULD PROMOTE AN
ISOLATED SHOWER ACROSS SOUTHEAST LOWER MICHIGAN. GIVEN VERY MARGINAL
MOISTURE PROFILES...WILL OMIT FROM FORECAST WITH JUST SLIGHTLY MORE
CONCENTRATED DIURNAL CU ACROSS THE FAR NORTHEAST. DESPITE LOW LEVEL
CAA...GOOD DEAL OF INSOLATION MOST AREAS SHOULD ALLOW FOR HIGHS IN
THE MID TO UPPER 70S.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
HIGH PRESSURE MOVING OUT OF CANADA WILL BRING COOL...DRY
WEATHER FOR THE FIRST PORTION OF THE LONG TERM PERIOD. AS THE
LONGWAVE PATTERN BECOMES MORE ZONAL INTO THE WEEKEND...
TEMPERATURES WILL WARM AND A FEW FRONTAL BOUNDARIES WILL DROP
SOUTHWARD INTO THE GREAT LAKES REGION WITH SHOWERS AND
THUNDERSTORMS POSSIBLE. THE FIRST OF THESE FRONTS WILL DROP
THROUGH ON FRIDAY. A FEW STORMS ARE POSSIBLE ALONG THIS
FRONT...BUT LIMITED INSTABILITY SHOULD LIMIT WIDESPREAD
DEVELOPMENT. THIS FIRST FRONT WILL SETTLE SOUTH OF THE AREA OVER
THE WEEKEND WHICH SHOULD KEEP OUR AREA DRY.
BETTER SHOWERS AND STORM CHANCES RETURN BY THE EARLY PART OF NEXT
WEEK AS MODEL CONSENSUS STALLS A FRONTAL BOUNDARY ACROSS THE
SOUTHERN GREAT LAKES. DEWPOINTS IN THE UPPER 60S TO LOW 70S COUPLED
WITH DAYTIME HEATING SHOULD PROVIDE WEAK TO MODERATE INSTABILITY
EACH DAY...DEPENDING ON THE DEGREE OF HEATING. AT THIS TIME...MID
LEVEL LAPSE RATES AND DEEP LAYER SHEAR LOOK LACKLUSTER WHICH SHOULD
PRECLUDE ANY ORGANIZED SEVERE WEATHER THREAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 140 AM EDT TUE AUG 11 2015
SOME POSTFRONTAL BR POSSIBLE THROUGH THE EARLY MORNING BUT
INCREASING SURFACE WIND SPEEDS AND DRY AIR ADVECTION SHOULD KEEP
CONDITIONS IN HIGH END MVFR OR BETTER. OTHERWISE VFR CONDITIONS
EXPECTED FOR THE REST OF THE PERIOD AS RIDGE OF HIGH PRESSURE
BUILDS OVER THE GREAT LAKES. NORTHWEST WINDS WILL GUST TO AROUND
20 KNOTS THIS AFTERNOON...ESPECIALLY AT KSBN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM 9 AM CDT THIS MORNING THROUGH LATE
TONIGHT FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM 10 AM EDT THIS MORNING THROUGH LATE
TONIGHT FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 2 AM EDT
WEDNESDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...MARSILI
LONG TERM...BENTLEY
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
214 AM CDT TUE AUG 11 2015
...Updated short term and long term discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 213 AM CDT TUE AUG 11 2015
For today a weak upper level disturbance is forecast to move
through the upper ridge axis and out into western Kansas. Ahead of
this disturbance I305 and I310 isentropic surfaces do indicated an
increase in moisture and lift, mainly across western Kansas. Given
this lift and timing on the upper level system will favor the
better opportunity for precipitation during the afternoon and
early evening. Still am unable t rule out some scattered
precipitation earlier in the day, especially across far southwest
Kansas as the isentropic lift and moisture improves between 12z
and 18z Tuesday. Based on expected cloud cover and afternoon 850mb
temperatures from the NAM and GFS will continue to favor highs
today mainly in the mid 80s. The warmer temperatures will be
across central Kansas where less cloud cover is expected while the
cooler temperatures will be in southwest Kansas.
There will be a chance for thunderstorms lingering into the
overnight hours as moisture and lift in the 800mb to 600mb level
continues to slowly move east across western Kansas. Based on the
NAM it appears that the better moisture an lift early tonight will
be mainly across west central Kansas so placed higher chances for
convection through midnight. Toward daybreak on Wednesday 850mb
warm air advection will begin to improve across western Kansas as
both the NAM and GFS begin to warm the 700mb temperatures.
Moisture, 850mb warm air advection, and isentropic lift will all
be in place by 12z just east of the 10c to 14c 700mb temperature
gradient so will increase the chance for convection again across
western Kansas late tonight and continue it into early Wednesday
morning.
.LONG TERM...(Wednesday THROUGH Monday)
ISSUED AT 213 AM CDT TUE AUG 11 2015
Temperatures on Wednesday will be a little tricky given how much
sun will develop during the afternoon. Even taking into account
the warmer GFS who favors more sun and warmer 850mb temperature
late day it currently appears the MAV/MOSGUIDE is too warm so will
stay close to the previous forecast which is only a couple of
degrees warmer than the cooler MET for highs.
Mid level temperatures are forecast to continue to warm mid week
as an upper level high moves from the Texas panhandle into
southern Colorado/northern New Mexico. Flow aloft will be weak
aloft but given that a surface boundary forecast to be located
near the Colorado border am unable to completely rule on a slight
chance for late day/evening storms across far western Kansas mid
week. At this time chances for convection will be isolated to
widely scattered at best.
The better opportunity for convection may be late week if the GFS
and ECMWF are correct with an upper level disturbance rotating
around the upper high and dropping south into the central plains.
Based on where the mid level baroclinic zone should be located
late week the opportunity will be more favorable across north
central Kansas.
The upper level ridge axis will shift east into the plains over
the weekend period as an upper low, located off the northern
California coast late week, weakens and lifts northeast toward the
northern Rockies. Temperatures late week into the weekend period
will be on the rise, however at this time the latest
CRExtendedFcst_Init may be a little slow on how quickly and how
warm temperatures will be over the weekend period based on the
850mb to 700mb temperatures. At this time however did not deviate
far from what the CRExtendedFcst_Init suggested.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Tuesday NIGHT)
ISSUED AT 1202 AM CDT TUE AUG 11 2015
BUFR soundings indicating a shallow layer of saturated air will
develop early this morning across portions of western Kansas as a
light easterly upslope flow develops. RAP and HRRR suggesting
mainly status will be possible towards daybreak west of highway
283, however at this time can not completely rule out some light
fog developing, especially at DDC and GCK. Will therefore trend
towards MVFR visibilities for a couple of hours around 12z Tuesday
with scattered IFR clouds at GCK. Otherwise VFR conditions can be
expected today with only an increase in mid level moisture
anticipated ahead of a weak upper level disturbance. Light east
winds will gradually shift to the southeast early this morning as
a surface ridge axis crosses western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 86 66 89 66 / 30 30 20 10
GCK 85 66 89 65 / 30 40 20 10
EHA 82 66 90 66 / 40 30 10 10
LBL 85 68 89 67 / 30 20 20 10
HYS 86 65 88 66 / 20 20 10 10
P28 87 68 88 68 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Burgert
LONG TERM...Burgert
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1203 AM CDT TUE AUG 11 2015
...Updated synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1202 AM CDT TUE AUG 11 2015
At 00z Tuesday a 500mb ridge axis extended from the panhandle of
Texas to eastern Montana. Water Vapor loop indicated an upper
level disturbance located over central New Mexico. A 700mb ridge
axis was located across western Kansas and western Oklahoma. A
large area of convection earlier this evening was located west of
this 700mb ridge axis and ahead of the upper level disturbance. A
surface ridge axis extended from central south Dakota to central
Kansas, and a weak surface boundary was located from southwest
Kansas into northern Oklahoma. 850mb temperatures at 00z Tuesday
across the boundary ranged from 23c at Dodge City to +15 at Omaha.
&&
.SHORT TERM...(THIS EVENING THROUGH Tuesday)
ISSUED AT 321 PM CDT MON AUG 10 2015
The latest arw and HRRR models were the most aggressive models
with respect to developing convection this afternoon. The 4 km nam
and the nmm were not as aggressive. However the nmm and 4 km HRRR
were also more aggressive with thunderstorms. The severe threat
will be minimal today and tonight with any storms that develop as
continued amplification the the upper ridge weakened the shear
profiles. However very heavy rainfall from efficient warm rain
processes will still be likely for the next day or so, but
steering flow will be weak or non existent. based on the HRRR,
thunderstorm coverage could become scattered by late in the
afternoon. additionally. thunderstorms development across
southeast colorado could spread into far southwest kansas later
this evening aided by weak vorticity advection embedded in the
northwest flow in the models.
.LONG TERM...(Tuesday NIGHT THROUGH Monday)
ISSUED AT 321 PM CDT MON AUG 10 2015
Beyond the short term, increasingly less humid conditions will
develop across central and much of western kansas as surface high
pressure from the northern plains begins to have greater
influence. The general low level moisture transport signal will
remain firmly anchored across the the western counties where the
main if any thunderstorms chances will be located, and the low
level jet may be the best mechanism for get a few thunderstorms
going. Generally high temperatures are forecast around 5 degrees
below climatology through the extended. Lowered dew points should
translate into overnight lows of a few degrees lower as well on
average.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Tuesday NIGHT)
ISSUED AT 1202 AM CDT TUE AUG 11 2015
BUFR soundings indicating a shallow layer of saturated air will
develop early this morning across portions of western Kansas as a
light easterly upslope flow develops. RAP and HRRR suggesting
mainly status will be possible towards daybreak west of highway
283, however at this time can not completely rule out some light
fog developing, especially at DDC and GCK. Will therefore trend
towards MVFR visibilities for a couple of hours around 12z Tuesday
with scattered IFR clouds at GCK. Otherwise VFR conditions can be
expected today with only an increase in mid level moisture
anticipated ahead of a weak upper level disturbance. Light east
winds will gradually shift to the southeast early this morning as
a surface ridge axis crosses western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 89 66 89 / 20 30 20 10
GCK 65 89 65 91 / 20 20 20 10
EHA 66 90 66 92 / 20 20 20 10
LBL 67 89 67 91 / 20 20 20 10
HYS 66 88 66 91 / 20 20 10 10
P28 68 88 68 88 / 10 20 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS PADUCAH KY
240 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
A FINAL BATCH OF SHOWERS WILL MOVE SOUTH THROUGH CARTER AND RIPLEY
COUNTIES IN MISSOURI EARLY THIS MORNING...THEN THE REMAINDER OF
THE SHORT TERM FORECAST IS DRY. THIS AFTERNOON...THE 00Z NAM IS
ATTEMPTING TO DEVELOP SOME SHALLOW CONVECTION. LOOKING AT ITS
SOUNDINGS FROM ACROSS THE REGION...IT APPEARS THERE WILL BE
SUBSTANTIAL COOLING IN THE 850MB TO 700MB LAYER...AND POSSIBLY
JUST ENOUGH LOW-LEVEL MOISTURE LEFT TO CREATE A SHALLOW LAYER OF
INSTABILITY BENEATH THE MID-LEVEL INVERSION. THE HRRR DEVELOPS A
FEW LIGHT SHOWERS...WHICH WOULD PROBABLY NOT EVEN MEASURE...SO
WILL KEEP THE FORECAST DRY FOR NOW.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY INTO
WEDNESDAY...AND THE FLOW ALOFT WILL BE NORTHWESTERLY AND FAIRLY
HEALTHY FOR THE MIDDLE OF AUGUST. NORTH WINDS UP TO 10KTS WILL MIX
DOWN EACH DAY...AND THAT WILL BRING COOLER AND MUCH DRIER AIR INTO
THE REGION. DEWPOINTS BY THE END OF THE DAY WEDNESDAY WILL BE IN
THE LOWER HALF OF THE 60S...AND UPPER 50S ARE EXPECTED BY DAYBREAK
THURSDAY IN THE EAST...AS THE SURFACE HIGH SETTLES OVERHEAD.
SHOULD SEE A DEFINITE TREND LOWER IN LOW TEMPERATURES FROM THIS
MORNING THROUGH WEDNESDAY NIGHT/THURSDAY MORNING...WITH WEAKENING
WINDS AND EVER DRIER AIR OVER THE REGION. HIGHS WILL TREND LOWER
TODAY AND WEDNESDAY AND THEN LEVEL OUT ON THURSDAY. DID NOT STRAY
FAR FROM THE CONSENSUS OF 00Z GUIDANCE FOR HIGHS OR LOWS THROUGH
THE PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
THE UPPER LEVEL RIDGE THAT HAS BEEN PERSISTENT ACROSS THE HIGH
PLAINS AND ROCKIES MOST OF THE SUMMER WILL REMAIN IN PLACE. THIS
RIDGE WILL BUILD NORTHEAST ACROSS THE GREAT LAKES REGION. AN UPPER
LEVEL TROUGH WILL MAINTAIN ITS PRESENCE OVER THE EASTERN STATES...
BUT UNDERGO A WEAKENING TREND AS IT SITS OVER THE APPALACHIANS. THE
NET RESULT FOR OUR REGION WILL BE A CONTINUATION OF DRY WEATHER.
SURFACE HIGH PRESSURE WILL REMAIN STATIONARY FROM THE CENTRAL PLAINS
TO THE OHIO VALLEY THROUGH THE WEEKEND. WITH LITTLE IN THE WAY OF
TEMPERATURE ADVECTION...HIGHS WILL REMAIN GENERALLY STEADY IN THE
UPPER 80S TO NEAR 90. BY EARLY NEXT WEEK...THE HIGH WILL RETREAT
SLOWLY TOWARD THE EAST...WHICH WILL PRODUCE A SOUTHWEST FLOW OF
SLIGHTLY HIGHER TEMPS AND DEW POINTS.
&&
.AVIATION...
ISSUED AT 1151 PM CDT MON AUG 10 2015
CONVECTION IS NOW SOUTH OF THE TAF SITES SO NO NEED TO WORRY ABOUT
THAT NOW. HOWEVER...MVFR/IFR CIGS/VSBYS POSSIBLE OVERNIGHT DUE TO
ABUNDANT LOW LEVEL MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION.
BY 15Z TUESDAY CONDITIONS SHOULD BE VFR WITH PLENTY OF SUNSHINE
AND LITTLE TO NO CLOUDINESS BUT A FEW CU ARE POSSIBLE. LIGHT AND
VARIABLE WINDS TONIGHT WILL BECOME NORTHERLY ON TUESDAY AOB 10
KTS. CLEAR SKIES AND LIGHT WINDS EXPECTED TUESDAY EVENING.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AREA FORECAST DISCUSSION
NWS JACKSON KY
135 AM EDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1250 AM EDT TUE AUG 11 2015
SOME CONVECTION FORMED OUT AHEAD OF THE BOUNDARY THIS EVENING AND
CONTINUES TO SLOW MOVE SOUTH ACROSS EASTERN KY. THESE SHOWERS AND
STORMS HAVE BEEN WEAKENING AS THEY MOVE SOUTH INTO MORE STABLE
AIR. GENERALLY TIMING NOT TOO BAD IN GRIDS SO JUST SOME MINOR
ADJUSTMENTS...AND ALSO ADJUSTED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 952 PM EDT MON AUG 10 2015
A BROKEN LINE OF SHOWERS/THUNDERSTORMS WAS DROPPING SOUTH THROUGH
THE REGION. THEY WERE SHOWING AN OVERALL SLOW WEAKENING TREND.
HOWEVER...ADDITIONAL SHOWERS WERE STARTING TO DEVELOP AHEAD OF
THE LINE. FORECAST GRIDS HAVE BEEN UPDATED TO TIME THE LINE SOUTH
INTO THE FORECAST AREA.
UPDATE ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 135 AM EDT TUE AUG 11 2015
SEVERAL SITES ARE STARTING OFF VFR THIS EVENING...THERE HAVE BEEN
A FEW EXCEPTIONS WHERE SOME HAVE SEEN RECENT RAIN SHOWERS OR SEEN
SOME MOSTLY CLEAR SKIES AT TIMES. OVERALL THE SHOWER ACTIVITY
CONTINUES TO WAIN AS IT MOVES SOUTH INTO MORE STABLE AIR IN PLACE
ACROSS THE REGION. DID OPT TO KEEP VCSH AT MOST SITES AND VCTS AT
SYM AND SJS AS SOME UPSTREAM STORM DEVELOPMENT COULD SKIRT THOSE
SITES. THE ISSUE OVERALL TONIGHT WILL BE FOG AND STRATUS
DEVELOPMENT...THIS WILL BE ESPECIALLY TRUE IN AREAS THAT HAVE SEEN
RAIN. THAT SAID MOST SITES WILL SEE IFR OR LOWER VIS AND/OR CIGS
OVERNIGHT INTO MORNING HOURS. THIS IS EXPECTED TO LIFT AS WE MOVE
INTO THE EARLY AFTERNOON HOURS. ONCE THE MAIN FRONT MOVES THROUGH
WE COULD SEE SOME ADDITIONAL SHOWER AND STORM DEVELOPMENT MAINLY
IN THE AFTERNOON...BUT MOST OF THIS WILL BE CONFINED TO THE SE.
AFTER THIS DRIER CONDITIONS WILL PREVAIL. WINDS WILL GENERALLY
REMAIN LIGHT THROUGH THE PERIOD BETWEEN 5 TO 10 KTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1250 AM EDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1250 AM EDT TUE AUG 11 2015
SOME CONVECTION FORMED OUT AHEAD OF THE BOUNDARY THIS EVENING AND
CONTINUES TO SLOW MOVE SOUTH ACROSS EASTERN KY. THESE SHOWERS AND
STORMS HAVE BEEN WEAKENING AS THEY MOVE SOUTH INTO MORE STABLE
AIR. GENERALLY TIMING NOT TOO BAD IN GRIDS SO JUST SOME MINOR
ADJUSTMENTS...AND ALSO ADJUSTED GRIDS WITH LATEST OBS AND TRENDS.
UPDATE ISSUED AT 952 PM EDT MON AUG 10 2015
A BROKEN LINE OF SHOWERS/THUNDERSTORMS WAS DROPPING SOUTH THROUGH
THE REGION. THEY WERE SHOWING AN OVERALL SLOW WEAKENING TREND.
HOWEVER...ADDITIONAL SHOWERS WERE STARTING TO DEVELOP AHEAD OF
THE LINE. FORECAST GRIDS HAVE BEEN UPDATED TO TIME THE LINE SOUTH
INTO THE FORECAST AREA.
UPDATE ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 915 PM EDT MON AUG 10 2015
CONDITIONS ACROSS THE REGION WERE VFR AT THE START OF THE
PERIOD. HOWEVER...A BROKEN LINE OF THUNDERSTORMS WAS JUST NORTH
OF THE JKL FORECAST AREA. IT WAS ASSOCIATED WITH A COLD FRONT
WHICH WILL DROP SOUTH THROUGH THE REGION TONIGHT...BRINGING
SCATTERED SHOWERS AND THUNDERSTORMS AND LOCALIZED IFR. MOST OF
THE PRECIPITATION WILL DIMINISH OR MOVE OUT TO THE SOUTHEAST
BEFORE DAWN. IN ITS WAKE WE WILL HAVE LOW CLOUDS AND FOG DEVELOP
AND BRING WIDESPREAD IFR OR BELOW...WHICH WILL LINGER INTO TUESDAY
MORNING. THE LOW CLOUDS AND FOG WILL LIFT/BREAK UP BY AROUND MID
DAY. SOME LIMITED REDEVELOPMENT OF SHOWERS/THUNDERSTORMS COULD
OCCUR DURING THE DAY TUESDAY...MAINLY IN SOUTHEAST KY. AS LESS
HUMID AIR FINALLY BEGINS TO ARRIVE BY THE END OF THE PERIOD...DRY
WEATHER WILL ARRIVE AND BE WITH US FOR A NUMBER OF DAYS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
348 AM CDT TUE AUG 11 2015
.SHORT TERM...
CONSIDERABLY DRIER COLUMN WITH LOWER DEWPOINTS OVER THE LARGER
SOUTHEAST REGION THIS MORNING...WHICH SHOULD HELP IN LOWERING
APPARENT TEMPERATURES BY A FEW DEGREES THIS AFTERNOON TO PRECLUDE
A HEAT WARNING. THE UPDATED TEMPERATURES AND HUMIDITY GRIDS YIELD
PROJECTED HEAT INDEX READINGS THAT ALIGN WELL WITH ONGOING HEAT
ADVISORY...WHERE 108 TO 112F IS POSSIBLE PRIOR RAINFALL ONSET.
THERE IS SOME UNCERTAINTY ON WHETHER TEMPERATURES WILL ACHIEVE
CRITERIA SHOULD RAINFALL ONSET SOONER...AS INDICATED BY HRRR AND
CONSIDERATIONS FOR DEVELOPING LINEAR MCS DEVELOPING AT THE ARK-
LA-MISS APEX. SOME DOWNRANGE DEVELOPMENT MAY TAKE PLACE BEFORE
SUNRISE THAT MOVES INTO SOUTHWEST MISSISSIPPI AND DISRUPT THE
DIURNAL TEMPERATURE TREND. MODELS ARE IN AGREEMENT WITH INCREASING
PRECIPITATION OVER A LARGE EXPANSE OF THE GULF COAST BY THIS
AFTERNOON AND WENT WITH MODEL BLENDS ON POPS AND TEMPERATURES IN
THE SHORT-TERM. MARGINAL RISK OF SEVERE STORMS TODAY WITH MAIN
THREATS DAMAGING WIND GUSTS THOUGH ISOLATED HAIL CAN NOT BE RULED
OUT AS WET-BULB ZERO LEVELS LOWER WITH STEEP HEIGHT FALLS
THROUGHOUT THE DAY. WEDNESDAY SHOULD SEE DRIER CONDITIONS THOUGH
DAYTIME TEMPERATURES MAY STILL REACH MID 90S WITH LOWER HUMIDITY
LEVELS. 24/RR
.LONG TERM...
UPPER RIDGE MOVES OVER DESERT SOUTHWEST AND STRENGTHENS WHILE DEEP
TROUGHING TAKES PLACE OVER THE EASTERN UNITED STATES WEDNESDAY AND
STAYS PLANTED ALONG THE EASTERN SEABOARD THROUGH FRIDAY BEFORE
LIFTING OUT OVER THE WEEKEND. SOME ENERGY IN THE BASE OF THE
TROUGH BREAKS OFF IN TIME TO BRING CUT-OFF LOW DYNAMICS DRIFTING
ALONG THE NORTH GULF COAST INTO NEXT WEEK. THIS TYPICALLY YIELDS
LOWER CONVECTIVE TEMPERATURE CONDITIONS WITH SOME COLD POOL
ENHANCEMENTS FOR EFFICIENT SEA BREEZE CONVECTION THAT SPREADS
LARGE ANVIL CANOPY OVER MUCH OF THE FORECAST AREA IN THE MID TO
LATE AFTERNOON HOURS THAT ERODE BY LATE EVENING. TEMPERATURES AND
RAIN CHANCES SHOULD BE CLOSE TO NORMAL LEVELS DURING THE EXTENDED
PORTIONS OF THE FORECAST PACKAGE. 24/RR
&&
.AVIATION...
2Z PACK WILL TRY TO TIME TSTORM COVERAGE PER TERMINAL. MOST SHOULD
SEE SOME ACTIVITY LATER TODAY. SHOULD START OUT DURING THE MORNING
FOR THE NORTHERN MOST SITES THEN PROGRESS SOUTHWARD DURING THE DAY.
WILL SHOW IFR CONDITIONS AS TEMPO GROUPS WILL BRING VIS RESTRICTIONS
AND WIND SPEEDS AND SHIFTS WILL BE A PROBLEM.
&&
.MARINE...
WINDS WILL BE MAINLY LESS THAN 10 KNOTS ALONG COASTAL
WATERS AND LAKE WITH SHORT DURATIONS OF 10 TO 15 IN THE AFTERNOON
AND EARLY EVENING HOURS POSSIBLE. THE MAIN CONCERN FOR THE NEXT
SEVERAL DAYS WILL BE THE POTENTIAL FOR THUNDERSTORMS...AS ANY STORMS
THAT DEVELOP COULD CERTAINLY PRODUCE WINDS IN EXCESS OF 40 KNOTS.
OUTSIDE OF THE THUNDERSTORM POTENTIAL EXPECT MOSTLY TRANQUIL
CONDITIONS. A WEAK FRONT WILL MOVE INTO THE COASTAL WATERS WEDNESDAY
WHICH WILL BRING SOME RELIEF FROM OPPRESSIVE HEAT AND HUMIDITY.
&&
.DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...HEAT ADVISORY ALL LAND AREAS EXCEPT EXTREME COASTAL SOUTHEAST LA
AND COASTAL MISSISSIPPI THROUGH 7 PM.
RIVER FLOOD WARNING ON MISSISSIPPI RIVER AT RED RIVER
LANDING.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 95 74 94 72 / 50 40 10 0
BTR 96 77 96 75 / 50 40 10 0
ASD 95 74 94 73 / 50 40 40 10
MSY 95 78 93 79 / 40 40 40 20
GPT 92 76 92 75 / 40 50 50 10
PQL 93 75 94 73 / 30 60 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ034>037-039-040-
046>050-056>065-071-072.
GM...NONE.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MSZ068>071-077.
GM...NONE.
&&
$$
24/RR
17/TE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
521 AM EDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE
ROCKIES/WRN PLAINS AND A TROF OVER ERN NAMERICA...RESULTING IN NNW
FLOW OVER THE UPPER GREAT LAKES EARLY THIS MORNING. UPSTREAM IN NRN
ONTARIO...SATELLITE IMAGERY AND SFC OBS SHOW LOW CLOUDS STEADILY
MOVING S AND NOW SPREADING OUT OVER FAR NRN LAKE SUPERIOR. THESE
CLOUDS WILL BE THE MAIN FCST ISSUE FOR TODAY. TO THE NW...FOCUSED
WAA REGIME IN MANITOBA IS PRODUCING SHRA/TSTMS EARLY THIS MORNING. A
SIMILAR SETUP MAY OCCUR LATE TONIGHT IN NRN ONTARIO/FAR NE MN AND
WRN LAKE SUPERIOR.
SATELLITE TRENDS AND GOOD AGREEMENT AMONG MODELS POINT TO A RAPID
INCREASE IN LOWER CLOUDS OVER NRN UPPER MI DURING THE NEXT SEVERAL
HRS. WITH OBS VERY SPARSE OVER NRN ONTARIO...TOUGH TO GAUGE HOW LOW
THE CLOUDS WILL BE AND WHETHER THERE MAY BE A RISK OF -DZ. THE ONLY
OB REPORTING CLOUDS IS AT GERALDTON...AND THE CIG THERE HAS BEEN
ABOVE 2KFT...NOT REALLY SUPPORTIVE OF -DZ. HOWEVER...THERE WAS ONE
OB THAT DID INDICATE -DZ. INITIALLY...PLANNED TO DROP PATCHY -DZ
MENTION OVER NCNTRL UPPER MI. HOWEVER...GIVEN THE ONE OB OF -DZ AND
THE POTENTIAL FOR THE WARMER WATERS OF SCNTRL LAKE SUPERIOR TO
FURTHER AID LOW CLOUD DEVELOPMENT IN FAVORABLE UPSLOPE FLOW...OPTED
TO RETAIN MENTION. 850MB THERMAL TROUGH OVER THE AREA TODAY SHOULD
ALLOW PLENTY OF STRATUS AND STRATOCU TO PERSIST WELL INTO THE AFTN
OVER MOST OF THE FCST AREA BEFORE STEADY CLEARING FROM THE W AND NW.
NNW WINDS GUSTING TO AROUND 25 MPH WILL BE AN ISSUE FOR MARINE
INTERESTS...ESPECIALLY ON LAKE SUPERIOR TO THE E OF THE HURON
ISLANDS AND ON NRN LAKE MICHIGAN. THE BREEZY NNW WINDS WILL MEAN
COOLEST CONDITIONS ALONG LAKE SUPERIOR OVER THE E WHERE LAKESIDE
TEMPS WILL BE IN THE LOW/MID 60S DURING THE DAY. MAX TEMPS IN THE
LOW/MID 70S ARE EXPECTED WELL INLAND...WARMEST FAR SCNTRL.
SFC HIGH PRES RIDGE MOVES OVER THE AREA TONIGHT...RESULTING IN
LIGHT/CALM WIND. WITH CLEAR SKIES FOR MUCH OF THE NIGHT...FAVORED
THE LOWER END OF AVBL GUIDANCE. INLAND FROM LAKE SUPERIOR...MANY
LOCATIONS SHOULD FALL TO THE 40S FOR MINS...WITH TRADITIONAL COLD
SPOTS TUMBLING TO AS LOW AS THE LWR 40S. LATE TONIGHT...THE SAME
FOCUSED WAA LEADING TO CONVECTION IN MANITOBA EARLY THIS MORNING
WILL BE POSITIONED IN NRN ONTARIO/FAR NE MN/WRN LAKE SUPERIOR. ALL
MODEL GUIDANCE POINT TOWARD REDEVELOPMENT OF CONVECTION IN THAT AREA
MOSTLY AFTER 06Z. WILL MAINTAIN SCHC POPS FOR SHRA/TSRA OVER NW LAKE
SUPERIOR INCLUDING ISLE ROYALE AFTER 08Z. WOULDN`T BE SURPRISED IF
LATER FCSTS NEED TO RAISE POPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT
MID CLOUDS WILL AFFECT BOTH SITES AT TIMES. AT KSAW...VFR CONDITIONS
SHOULD PREVAIL UNTIL LATE IN THE NIGHT WHEN LOW CLOUDS DROP ACROSS
LAKE SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN ON NORTH WINDS.
CIGS SHOULD SETTLE INTO THE LOW MVFR RANGE AROUND SUNRISE...WITH
SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH DRYING BY AFTERNOON FOR
CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WITH SFC HIGH PRES RIDGE APPROACHING FROM THE W...NNW WINDS WILL BE
FAIRLY BRISK OVER ERN LAKE SUPERIOR TODAY...WITH GUSTS FREQUENTLY
AROUND 20KT. OVER WRN LAKE SUPERIOR...WINDS WILL BE LIGHTER...
ESPECIALLY IN THE AFTN AS MESO HIGH PRES DEVELOPS OVER THE WRN LAKE.
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TONIGHT/WED
MORNING. WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW WED
AFTN OVER WRN LAKE SUPERIOR AS THE HIGH PRES RIDGE DRIFTS E. THESE
SW WINDS OF 10-20KT WILL CONTINUE INTO THU AHEAD OF COLD FRONT
APPROACHING FROM THE NW. DEPENDING HOW MUCH THE PRES GRADIENT
TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF GUSTS TO INCREASE
TO THE 20-30KT RANGE...ESPECIALLY AT THE HIGH OBS PLATFORMS. THE
STRONGEST GUSTS WOULD OCCUR OVER WRN LAKE SUPERIOR. WINDS WILL
DIMINISH AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON
FRI AS HIGH PRES BUILDS INTO THE UPPER LAKES. THESE LIGHTER WINDS
WILL LINGER INTO AT LEAST SAT MORNING BEFORE WINDS BEGIN TO INCREASE
AGAIN AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
313 AM EDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT
MID CLOUDS WILL AFFECT BOTH SITES AT TIMES. AT KSAW...VFR CONDITIONS
SHOULD PREVAIL UNTIL LATE IN THE NIGHT WHEN LOW CLOUDS DROP ACROSS
LAKE SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN ON NORTH WINDS.
CIGS SHOULD SETTLE INTO THE LOW MVFR RANGE AROUND SUNRISE...WITH
SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH DRYING BY AFTERNOON FOR
CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
137 AM EDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 137 AM EDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT
MID CLOUDS WILL AFFECT BOTH SITES AT TIMES. AT KSAW...VFR CONDITIONS
SHOULD PREVAIL UNTIL LATE IN THE NIGHT WHEN LOW CLOUDS DROP ACROSS
LAKE SUPERIOR AND MOVE INTO NORTHERN UPPER MICHIGAN ON NORTH WINDS.
CIGS SHOULD SETTLE INTO THE LOW MVFR RANGE AROUND SUNRISE...WITH
SOME POTENTIAL OF IFR CIGS. EXPECT ENOUGH DRYING BY AFTERNOON FOR
CIGS TO LIFT TO VFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
314 AM CDT TUE AUG 11 2015
.DISCUSSION...
Issued at 314 AM CDT TUE AUG 11 2015
Slightly below normal temperatures and significantly lower humidity
throughout the region today will allow maximum heat indices to fall
nearly 15 degrees from yesterday`s max values, and will feel like a
brief reprieve from summer after days of sticky conditions. North
northeasterly surface winds will remain sustained at ~10-12 mph
through the day as the pressure gradient tightens in response to
surface high pressure building over north central KS, which will
also promote additional mixing out of low-level moisture on top of
the dry air advection already occurring. Felt that the RAP had the
right idea but was a little overdone in mixing to nearly 750 hPa, so
balanced between the RAP`s and HRRR`s warmer/drier solution with
consensus model solutions to bring highs into the mid 80s in most
locations this afternoon, and dewpoints into the lower 60s.
Upper-level high pressure over the desert southwest will expand and
bulge eastward over the next several days, keeping the forecast area
fully entrenched in northwest to northerly flow aloft through the
work week and into the weekend. At the surface, persistent high
pressure will very gradually drift and build to the southeast,
abating winds and mixing for Wednesday, then eventually allowing
weak southerly flow to return late Thursday or early Friday.
Sunshine should be abundant and precipitation chances nil this week
as the blocking upper high prevents even the most ambitious short-
wave energy from riding the length of the ridge and down into the
region. When the upper high finally begins to retreat southwest and
break down, ridging will edge northeastward into the upper Midwest,
bringing the thermal ridge closer to the forecast area and allowing
temperatures to return to the lower 90s for the weekend. Storm
chances don`t return until very late in the period when upper-level
flow finally flattens to zonal and a shortwave trough slides through
the central Plains, but timing of this feature continues to slow,
and its northern track could limit the possibility of precipitation
in the majority of the CWA.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1131 PM CDT MON AUG 10 2015
Dry air continues to move over the region as surface high pressure
settles into place. Overnight fog is still a possibility, though with
new model runs, the outlook is improving slightly. Still think the
terminal sites will see development, but will likely remain shallow
and patchy, with the exception of KSTJ. This should taper off after
sunrise with gradually veering winds and clear sky conditions through
the remainder of the period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
351 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1142 PM CDT MON AUG 10 2015
WITH LIGHT EAST TO SOUTHEAST WIND AND SURFACE DEWPOINTS IN THE LOW
TO MID 60S...CONDITIONS MIGHT BE FAVORABLE FOR PATCHY SHALLOW FOG TO
DEVELOP. HOWEVER...THE DEWPOINT JUST ABOVE THE SURFACE WOULD
INDICATE THAT THE LOW TEMPERATURES WOULD NEED TO REACH THE MID 50S
FOR FOG TO BECOME WIDESPREAD AND TO LIMIT THE VISIBILITY
SIGNIFICANTLY. THE SHORT TERM MODELS DO NOT INDICATE THAT SUCH A
SCENARIO IS LIKELY TO OCCUR. THERE IS A SLIGHTLY HIGHER PROBABILITY
THAT STRATUS CEILINGS LESS THAN 1000 FEET AGL COULD DEVELOP ALONG
AND WEST OF AN IEN-OGA-IML LINE BUT THERE IS NO MODEL INDICATION
THAT THE STRATUS CEILINGS WILL REACH AS FAR EAST AS VTN-TIF-LBF.
OTHERWISE...UNLIMITED CEILING AND VISIBILITY CAN BE EXPECTED IN MOST
OF CENTRAL AND WESTERN NEBRASKA. IN NORTHERN NEBRASKA...SOME MIDDLE
CLOUD CEILINGS ARE EXPECTED TO DEVELOP LATE TUESDAY MORNING OR EARLY
AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...SPRINGER
HYDROLOGY...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
342 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 11 2015
THE SHORT TERM FORECAST REMAINS FAIRLY QUIET THROUGH THE NEXT 24
HOURS...WITH DRY CONDITIONS AND VERY LITTLE CHANGES MADE TO THE
PREVIOUS FORECAST. AN UPPER LEVEL RIDGE REMAINS DOMINATE ACROSS THE
SOUTHERN HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL CLOSED LOW
TRUDGES OFF THE PACIFIC COASTLINE. AN OPEN WAVE HAS BEGUN TO SLIDE
EASTWARD ACROSS THE GREAT LAKES REGION. THE RIDGE AXIS IN THE MID
LEVELS IS SLIGHTLY MORE PRONOUNCED AND AMPLIFIED ACROSS THE FRONT
RANGE. ALONG THIS RIDGE AXIS...RETURN FLOW COMBINED WITH WARM AIR
ADVECTION HAS ALLOWED MOISTURE TO SURGE NORTHWARD ALONG THE FRONT
RANGE. AT THE SURFACE HIGH PRESSURE HAS SHIFTED ACROSS THE CENTRAL
PLAINS. LATEST OBS REFLECT THIS FEATURE AS MOST AIRPORT WINDS ARE
LIGHT TO CALM.
ALTHOUGH THIS IS NOT REFLECTED IN THE FORECAST...THERE ARE SOME
CONCERNS ABOUT PATCHY FOG DEVELOPMENT THIS MORNING. EVEN THOUGH
DEWPOINTS ARE LOWER THAN PREVIOUS DAYS...TEMPERATURES ARE ALSO
SLIGHTLY COOLER. AT THE PRESENT TIME...RELATIVE HUMIDITY VALUES ARE
ABOVE 90 PERCENT IN MOST AREAS. MODEL SOLUTIONS SUCH AS THE
NAM...RAP...AND HRRR ALL SUGGEST LOWERED VISIBILITIES ESPECIALLY FOR
LOCATIONS WEST OF 281...MAINLY ALONG THE SURFACE RIDGE AXIS. SINCE
THIS WILL LIKELY BE PATCHY IN NATURE...WILL CONTINUE TO MONITOR
LATEST TRENDS BEFORE INTRODUCING INTO GRIDS.
THE REST OF TODAY LOOKS TO REMAIN QUIET AS THE SURFACE RIDGE SLIDES
THROUGH THE AREA. LIGHT WINDS ARE EXPECTED AND HIGH TEMPERATURES
SHOULD TOP OUT NEAR NORMAL WITH HIGHS IN THE MID 80S FOR MOST
LOCATIONS. FURTHER WEST...A SMALL DISTURBANCE WILL DEVELOP ALONG THE
FRONT RANGE...AND COMBINED WITH MOISTURE AND WARM AIR ADVECTION WILL
LIKELY SPAWN THUNDERSTORMS. 0Z MODEL SOLUTIONS PULLED POPS BACK
FURTHER WEST AND THUS WENT AHEAD AND REMOVED ANY MENTION OF
THUNDERSTORMS FROM WESTERN ZONES TUESDAY NIGHT. HOWEVER...WOULD NOT
BE SURPRISED TO SEE A STORM MAKE A RUN FOR THE WESTERN ZONES DURING
THIS TIME FRAME. EVEN THE 6Z NAM...HAS NOW REVERTED BACK TO POPS IN
NORTH CENTRAL KANSAS BY EARLY MORNING WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 11 2015
AN UPPER RIDGE OF HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE
ACROSS THE INTERIOR CONUS THROUGH THE WORKWEEK. THE PATTERN WILL BE
BLOCKY AT THE START WITH CLOSED LOWS IN THE PACIFIC OCEAN OFF THE
COAST OF CALIFORNIA AND ANOTHER TROUGH ALONG THE EAST COAST. UNDER
THE INFLUENCE OF THE RIDGE...PRECIPITATION CHANCES WILL BE
NEGLIGIBLE UNTIL THE WEEKEND TIME FRAME WHEN THE WESTERN LOW LIFTS
OUT AND BREAKS DOWN THE INTERIOR CONUS RIDGE. ALTHOUGH THE FORECAST
REMAINS DRY UNTIL SATURDAY NIGHT WILL NEED TO KEEP AN EYE ON
CONVECTION WHICH DEVELOPS ALONG THE HIGHS PLAINS AS ACTIVITY MAY TRY
TO WORK INTO OUR WESTERN ZONES.
THE PATTERN CHANGE ARRIVES OVER THE WEEKEND AS THE AFOREMENTIONED
WESTERN SYSTEM LIFTS OUT AND CROSSES THE NORTHERN CONUS. AN
ASSOCIATED COLD FRONTAL BOUNDARY ADVANCES SOUTH FROM THE DAKOTAS
LATE SATURDAY WITH CHCS FOR TSTMS RETURNING AS FRONT ARRIVES. THE
ECMWF IS SLOWER WITH BOUNDARY PROGRESSION THAN THE GFS BUT HARD TO
PINPOINT THE DETAILS THIS FAR OUT. THE BOUNDARY IS PROGGED TO STALL
OR MEANDER ACROSS OUR REGION INTO EARLY NEXT WEEK AND WITH BOUNDARY
IN THE AREA CHANCES FOR STORMS CONTINUE. TEMPERATUREWISE...READINGS
WILL BE TYPICAL OF SUMMER WITH HIGHS IN THE 80S TO LOW 90S...WITH
LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1231 AM CDT TUE AUG 11 2015
VFR CONDITIONS ARE EXPECTED THROUGHOUT THE TAF PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...FAY
AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1155 PM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT THROUGH THURSDAY)
ISSUED AT 315 PM CDT MON AUG 10 2015
THE FORECAST CHALLENGES WILL BE ANY SPOTTY PRECIPITATION AND
PATCHY FOG...OTHERWISE...MAINLY QUIET AND SEASONABLE WEATHER WITH
SURFACE HIGH PRESSURE OVER THE AREA FOR THE NEXT COUPLE OF DAYS.
ON THIS MORNING/S UPPER AIR MAPS...AN H3 JET WAS STRETCHED ACROSS
NEBRASKA. THE H5 RIDGE WAS OVER THE ROCKIES WITH A CLOSED LOW OFF
THE WEST COAST AND A SHORTWAVE TROF OVER SOUTHERN MINNESOTA INTO
SOUTH DAKOTA. THE BEST H7 DEWPOINTS WERE POOLED TO THE SOUTH FROM
THE TEXAS PANHANDLE INTO OKLAHOMA AND PARTS OF SOUTHERN COLORADO AND
NEW MEXICO AND MEXICO. 14-16 DEGREE H85 DEWPOINTS STRETCHED IN THIS
SAME AREA...BUT ALSO EXTENDED INTO KANSAS...WITH A 13 DEGREE H85
DEWPOINT LINGERING AT OAX.
THE HRRR AND HIRESW ARW/NMM HAVE SOME SPOTTY PRECIP PRIOR TO
00Z...AND THE HRRR LINGERS IT INTO THE EVENING...WHILE THE NAM/GFS
ARE MOSTLY DRY. CONVECTIVE TEMPERATURES ARE IN THE LOWER 80S...
THUS WILL CONTINUE TO MONITOR CU FIELDS FOR ANY SPOTTY POP UP
SHOWERS. THE DMX RADAR HAS A FEW SHOWERS WITH THE SHORTWAVE
PASSING THROUGH SOUTHERN IOWA. DRIER DEWPOINTS HAD MOVED INTO
EASTERN NEBRASKA...HOWEVER SOME HIGHER 14 DEG DEWPOINTS WERE STILL
IN WESTERN IOWA ALONG WITH SOME MOISTURE CONVERGENCE IN THIS AREA.
THE BEST MLCAPES PER THE SPC MESOANALYSIS WAS OVER KANSAS AND
MISSOURI WITH 500 J/KG MLCAPES OVER EASTERN NEBRASKA/WESTERN IOWA.
WITH THE WET GROUND IN SPOTS AND LIGHT WINDS TONIGHT...SOME HINTS
OF PATCHY FOG IN LOW LYING AREAS/RIVER VALLEYS WITH 1 TO 2 DEGREE
DEWPOINT DEPRESSIONS.
THE NAM HAS SOME SPOTTY PRECIP AGAIN TUESDAY EVENING MAINLY JUST
WEST OF THE FORECAST AREA AND TOWARD HARLAN WITH CONVECTION THAT
FORMS WITH THE INCREASING LOW LEVEL JET IN THE HIGH PLAINS/THETA-E
ADVECTION. THE GFS IS GENERALLY DRY THROUGH THURSDAY. WILL
MAINTAIN A MAINLY DRY FORECAST THROUGH THE SHORT TERM UNTIL THERE
IS BETTER AGREEMENT ON SUBTLE FORCING FEATURES FOR PLACEMENT OF
ANY ISOLATED PRECIPITATION.
LOWS TONIGHT SHOULD DROP BACK INTO THE 50S TO LOWER 60S TUESDAY
MORNING. HIGHS SHOULD BE IN THE 80S TUESDAY AND WEDNESDAY WITH
WARMER 80S TO LOWER 90S THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 315 PM CDT MON AUG 10 2015
A RIDGE OF HIGH PRESSURE ALOFT WILL KEEP TEMPERATURES ABOVE NORMAL
IN THE UPPER 80S TO LOWER 90S FRIDAY AND SATURDAY. THE RIDGE
BREAKS DOWN FOR THE WEEKEND INTO EARLY NEXT WEEK AS A COLD FRONT
SLIPS INTO THE AREA AND STALLS. FOR NOW...DO HAVE A CHANCE FOR
THUNDERSTORMS WITH THE FRONT SATURDAY NIGHT INTO MONDAY. THERE ARE
SOME TIMING DIFFERENCES WITH THE EC BEING SLOWER.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1154 PM CDT MON AUG 10 2015
THE COMBINATION OF MOISTURE AT THE SURFACE AND LIGHT WINDS COULD
CREATE SOME PATCHY FOG AT KOFK AND KOMA EARLY TUESDAY MORNING.
OTHERWISE VFR CONDITIONS WILL PREVAIL.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...KG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
120 AM EDT TUE AUG 11 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TUESDAY AND MAY EXTEND INTO WEDNESDAY
AS A COLD FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE
WILL BUILD IN BEHIND THE FRONT WEDNESDAY...OFFERING SEASONABLE
AND MAINLY DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY
RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS
MOISTURE ONSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 115 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
TRIMMED BACK FORECAST SHOWER CHANCES A LITTLE MORE AS ONLY A FEW
SPOTTY RETURNS ARE NOTED UPSTREAM ON RADAR ACROSS SOUTH CAROLINA.
THE HEAVIER ACTIVITY WHICH AFFECTED THE CHARLOTTE/LAKE NORMAN AREA
EARLIER THIS EVENING IS TAKING OFF TO THE NE ACROSS
ASHEBORO/BURLINGTON AND WILL MISS MY FORECAST AREA WELL TO THE
NORTH. THE MODELS WHICH SEEM TO HAVE A GOOD HANDLE ON THE EASTERN
EDGE OF THE PRECIP INCLUDE THE 12Z ECMWF...00Z NAM...AND 12Z NMM-
ARW. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO TEMPERATURES.
DISCUSSION FROM 300 PM FOLLOWS...
CLOUD COVER HAS BEEN PRETTY EXTENSIVE ACROSS THE INLAND HALF OF
THE CWA...BUT COASTAL SECTIONS HAVE ONCE AGAIN EXPERIENCED A GREAT
EARLY-AUGUST DAY. MOISTURE WILL CONTINUE TO INCREASE IN BOTH THE
MID-LEVELS AND AT THE SURFACE...FINALLY OVERCOMING THE VERY DRY
AIR IN PLACE AS THE SURFACE RIDGE OVERHEAD SHIFTS OFFSHORE.
SHOWERS THAT HAD DEVELOPED WEST OF THE CWA HAVE ERODED AS EXPECTED
THANKS TO ENCOUNTERING DRY AIR...AND HIGH RES GUIDANCE INCLUDING
THE HRRR AND NSSL WRF BOTH KEEP THE CWA DRY THROUGH TONIGHT. HAVE
REMOVED MENTION OF POP FROM EVEN IN THE FAR INLAND ZONES THROUGH
DARK TO ACCOUNT FOR TRENDS IN SATELLITE AND RADAR.
TONIGHT...COLUMN SATURATION WILL CONTINUE TO INCREASE WITH PWATS
RISING TOWARDS 2 INCHES BY TUESDAY MORNING. COLD FRONT APPROACHING
FROM THE WEST WILL BE NEAR THE CWA BY MORNING...WITH SHOWERS AND
THUNDERSTORMS INCREASING AHEAD OF IT. FORECAST PROFILES SUGGEST
ENOUGH SATURATION INLAND THAT POP HAS BEEN RAMPED UP TO HIGH CHC
FROM I-95 WESTWARD BY 8AM TUESDAY...WITH JUST SCHC ALONG THE
COAST...BUT MOST OF THE PRECIP WILL HOLD OFF UNTIL AFTER THIS PERIOD.
INCREASING CLOUD COVER AND CONTINUED LIGHT SOUTHERLY WINDS WILL KEEP
MINS ELEVATED TO ABOVE SEASONABLE NORMS TONIGHT. THE MAV AND MET ARE
IN GOOD AGREEMENT...AND HAVE FORECAST MORE CLOSELY TO THE SLIGHTLY
WARMER MAV NUMBERS. EXPECT LOWS IN THE 72-75 DEGREE RANGE THROUGHOUT
THE AREA.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE PRIME WEATHER CAPTION FOR TUE/WED IS RAIN
AS AN APPROACHING FRONTAL SYSTEM WITH RELATIVELY HIGH AMOUNTS OF
INGESTED PRECIPITABLE WATER...CROSSES THE APPALACHIAN MOUNTAINS
EARLY TUESDAY AND MOVES TO THE COAST TUESDAY NIGHT. IT APPEARS A
WEAK WAVE OF LOW PRESSURE MOVING NNE ALONG THE FRONT MAY SUSTAIN
ISOLATED COASTAL SHOWERS SLIGHTLY BEHIND THE DECAYING FRONTAL SYSTEM
ON WEDNESDAY. BEST FIT AND CONSENSUS QPF DEPICTIONS OF STORM/SYSTEM
TOTAL POINTS GENERALLY TO 0.50-0.75 INCHES OF RAIN TUE/WED AND
HIGHEST ALONG AREAS IN PROXIMITY TO THE COAST. A TREND OF DRYING
WILL PREVAIL ON WEDNESDAY ESPECIALLY INLAND...IN THE FACE OF
ISOLATED COASTAL SHOWERS.
POST-FRONTAL DOWNSLOPE WIND FLOW WEDNESDAY WITH LITTLE COLD AIR
ADVECTION WILL LIKELY RESULT IN A SEASONABLY WARM DAY WEDNESDAY
ALTHOUGH WE WILL OBSERVE SEVERAL DEGREES OF DEWPOINT DROPS THROUGH
WEDNESDAY...TAKING A SLIGHT EDGE OFF THE HUMIDITY LEVELS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING WILL PERSIST ACROSS THE
EAST/SOUTHEAST THROUGH SATURDAY WITH MORE OF A ZONAL PATTERN
DEVELOPING THEREAFTER. GENERALLY QUIET WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES FROM THE MIDWEST TO THE APPALACHIANS THROUGH THE
PERIOD. THE HIGH WILL WEAKEN WITH THE MID LEVEL TROUGH THUS LEAVING
A WEAK PRESSURE PATTERN BOTH AT THE SURFACE AND ALOFT. HAVE
CONTINUED THE SLIGHT CHANCE POPS WHICH ARE MOSTLY CONFINED TO THE
COASTAL AND OFFSHORE ZONES. THE TEMPERATURE CURVE FOLLOWS THE SAME
PROGRESSION WITH COOL READINGS EARLY ON...FRIDAY SHOULD BE THE
COOLEST WITH 850MB TEMPERATURES NEAR 15 DEGREES C. THERMAL PROFILES
SLOWLY MODIFY FROM THAT POINT ON. READINGS MAY ECLIPSE CLIMATOLOGY
JUST BY A DEGREE OR TWO BY THE END OF THE PERIOD.
&&
.AVIATION /05Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...OUTSIDE OF CONVECTIVE DEBRIS...REMAINDER OF THE NIGHT
SHOULD BE QUIET WITH MAINLY VFR CONDITIONS EXPECTED. AFT
12Z...SHOWERS SHOULD BE ON THE INCREASE AS A COLD FRONT
APPROACHES. TERMINALS MAINTAIN VFR CONDITIONS THROUGH 18Z WITH
VCSH WITH SCT SHRA IN THE AREA. AFT 18Z...ALL TERMINALS SHOWING
RAMP UP FROM PROB30 FOR TSRA WITH MVFR CIGS TO TEMPO FOR SIMILAR
CONDITIONS FROM 00Z WEDNESDAY THROUGH 04Z. SHORT DURATION IFR IS
POSSIBLE WITH TSRA BUT CONFIDENCE IN EXACT TIMING AT EACH TERMINAL
IS LOW ATTM.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND STORMS TUESDAY NIGHT
WITH INTERMITTENT MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY WITH
ISOLATED MORNING CONVECTION POSSIBLE. VFR THURSDAY THROUGH
SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 115 AM TUESDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
WINDS ARE QUITE A BIT STRONGER AT THE BEACHES THAN THEY ARE WAY
OUT AT THE FRYING PAN SHOALS BUOY. THIS IS ACTUALLY EXPECTED AS A
WEAKER PRESSURE GRADIENT EXISTS OFFSHORE NEAR THE HIGH PRESSURE
RIDGE. MODELS REMAIN IN GOOD AGREEMENT ABOUT GRADUALLY BUILDING
WIND SPEEDS AS THE RIDGE SCOOTS OUT TO THE SEAS. SEAS ARE
CURRENTLY 2 FEET...BUT WON`T BEGIN TO BUILD UNTIL AFTER DAYBREAK.
DISCUSSION FROM 300 PM FOLLOWS...
WEAK RIDGE OF HIGH PRESSURE WILL SLOWLY SHIFT OFFSHORE
TONIGHT...SO ALTHOUGH THE GRADIENT WILL REMAIN LIGHT KEEPING WIND
SPEEDS TO 10 KTS OR LESS...DIRECTION WILL CONTINUE TO VEER THROUGH
TONIGHT...FROM CURRENT ESE ALL THE WAY TO SSW LATE. CURRENT BUOY
OBS SHOW A MIX OF 5 SEC AND 10 SEC WAVES...WITH THE 10 SEC WAVE
DOMINANT DUE TO THE LIGHT WINDS...AND THESE WILL PERSIST THROUGH
THE PERIOD MAINTAINING WAVE HEIGHTS OF 2-3 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...MAIN MARINE HEADLINE THIS PERIOD REMAINS
APPROACH AND DECAY OF A COLD FRONTAL SYSTEM OVER THE COASTAL
WATERS DURING THE DAY WEDNESDAY. THIS MAY BRING A BRIEF PERIOD
OF N-NW WINDS WEDNESDAY...PRECEDED BY COASTAL RAIN SHOWERS AND
ISOLATED TSTMS TUESDAY NIGHT. A FEW TSTMS MAY IMPACT THE OUTER
WATERS ON WEDNESDAY AS WELL SINCE THE FRONT MAY SLOWLY DISSIPATE
THERE MID-WEEK. SEAS WILL BUILD TO 3-4 FT TUESDAY NIGHT AHEAD OF
THE COLD FRONT IN 15-20 KT SW WINDS...POSSIBLY 5 FT VERY OUTER
PORTION. SEAS SETTLING TO 2-3 FT WED AFTN AND EVENING AS WIND
SPEEDS GO LIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE WILL MOVE FROM THE MIDWEST TO THE
APPALACHIANS THROUGH THE PERIOD. THE HIGH WILL SLOWLY WEAKEN LEAVING
A BENIGN PRESSURE PATTERN BY SATURDAY. FOR THURSDAY AND FRIDAY
WINDS WONT BE OVERWHELMING AND EXPECT A EAST/NORTHEAST DIRECTION IN
A RANGE OF 10-15 KNOTS...MOSTLY HOVERING IN THE LOWER END OF THE
RANGE. SPEEDS DROP TO TEN KNOTS AND BELOW BY SATURDAY. SIGNIFICANT
SEAS WILL BE 1-3 FEET WITH AN EQUAL MIX OF A SHORTER PERIOD WIND
WAVE AND SWELL COMPONENT.
&&
.EQUIPMENT...
AS OF 130 PM MONDAY...POWER TO THE ILM ASOS HAS BEEN LOST DUE TO
A POWER SURGE. A REPLACEMENT IS ON ORDER...BUT IT IS LIKELY THAT
ILM ASOS WILL BE WITHOUT AUTOMATED OBSERVATIONS THROUGH TODAY AND
PART OF TUESDAY. THE ILM TOWER SHOULD AMEND OBSERVATIONS UNTIL 11
PM TONIGHT...AND RESUME EARLY TUESDAY MORNING. OVERNIGHT OBS MAY
WILL BE MISSING FOR ALL PARAMETERS. AMD NOT SKED HAS BEEN APPENDED
TO THE ILM TAF AND WILL REMAIN AS SUCH UNTIL POWER IS RESTORED TO
THE SITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...REK/TRA
SHORT TERM...99
LONG TERM...99
AVIATION...REK/RAN
MARINE...99/REK/TRA
EQUIPMENT...99
AREA FORECAST DISCUSSION
NWS RALEIGH NC
100 AM EDT TUE AUG 11 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...
AND PUSH SOUTHEAST THROUGH THE AREA THIS EVENING. HIGH PRESSURE WILL
BUILD IN FROM THE NORTHWEST WEDNESDAY THROUGH FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 PM MONDAY...
WATER VAPOR IMAGERY AND RAP 500MB VORT ANALYSIS SHOW SEVERAL
DISTURBANCES ALOFT THAT CONTINUE TO SUPPORT BROKEN BANDS OF MOSTLY
WEAK CONVECTION FROM WESTERN VIRGINIA SOUTH INTO GEORGIA AND
ALABAMA. LOCALLY...A BRIEF PERIOD OF HEATING/DESTABILIZATION OVER
THE WESTERN PIEDMONT AND THE DEVELOPMENT OF SOME MODERATE DCAPE
EARLIER THIS AFTERNOON ALSO APPEARS TO BE SUPPORTING A DISORGANIZED
COLD POOL AND SLOWLY WEAKENING SHOWERS/STORMS FROM THE TRIAD TO NEAR
ALBEMARLE. NOCTURNAL COOLING WILL FAVOR A CONTINUED WEAKENING OF
THIS CONVECTION...BUT RAP FORECAST SOUNDINGS SHOW A 35-40KT LOW
LEVEL JET FROM CLT TO RDU AFTER MIDNIGHT THAT MAY HELP TO TAP
WHATEVER WEAK MUCAPE IS LEFT AND MAINTAIN SOME SCATTERED SHOWERS.
THIS IS LOOSELY SUPPORTED BY RECENT HRRR RUNS. THE FORECAST UPDATE
WILL HAVE A CHANCE POP OVERNIGHT BECOMING INCREASINGLY FOCUSED TO
THE EAST TOWARD 12Z. OTHERWISE...REGIONAL SATELLITE IMAGERY SHOWS
PLENTY OF CONVECTIVE DEBRIS CLOUDINESS AND SKIES MOSTLY CLOUDY FOR A
MAJORITY OF THE AREA. LOWS IN THE LOW TO MID 70S.
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 PM MONDAY...
STILL APPEARS TO BE THE WETTEST DAY... WITH ALL LARGE-SCALE MODELS
INCLUDING THE SREF MEAN INDICATING NUMEROUS SHOWERS AND STORMS...
ALTHOUGH DETAILS OF THE TIMING AND WHAT LOCATIONS WILL SEE THE
GREATEST AMOUNTS AND COVERAGE ARE STILL MURKY. FALLING MID LEVEL
HEIGHTS WITH THE DIGGING TROUGH ALONG WITH MID LEVEL DPVA...
INCREASING UPPER DIVERGENCE ASSOCIATED WITH A STRENGTHENING JET
STREAK OVER IA/IL... AND DECENT LOW LEVEL MOISTURE TRANSPORT WILL
WORK WITH 1000-2000 J/KG OF MUCAPE (ON THE GFS... ALTHOUGH THIS MAY
BE OVERDONE GIVEN EXTENSIVE MORNING CLOUD COVER) AND IMPROVING DEEP
LAYER SHEAR OF 25-30 KT TO FORCE SHOWERS AND STORMS... PEAKING
DURING THE AFTERNOON INTO MID EVENING... AHEAD OF THE APPROACHING
SURFACE COLD FRONT. THE SEVERE THREAT STILL LOOKS MARGINAL... GIVEN
THAT THE BETTER DYNAMIC FORCING FOR ASCENT SHOULD BE JUST TO OUR
NORTH AND NE ALONG THE MIDATLANTIC COAST WITH THE BETTER
INSTABILITY/SHEAR COMBINATION TO OUR SOUTH AND SW OVER UPSTATE SC
AND GA... BUT A FEW DAMAGING WIND REPORTS ARE STILL POSSIBLE IN THIS
INCREASINGLY VOLATILE ENVIRONMENT. EXPECT HIGHS MOSTLY IN THE MID
80S. POPS SHOULD LOWER FROM NW TO SE TUE NIGHT... TRENDING DOWN TO
JUST A SLIGHT CHANCE IN THE SE BY LATE TUE NIGHT. LOWS 65-70. -GIH
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
THE MAIN FRONT WILL SHIFT OFFSHORE ON WEDNESDAY...WITH GENERAL UPPER
LEVEL TROUGHINESS LINGERING OVER THE CAROLINAS THROUGH MONDAY. AT
THE SURFACE...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
REMAIN OVERHEAD THROUGH MONDAY. WITH THAT IN MIND...MOST OF THE
EXTENDED PERIOD WILL REMAIN DRY...WITH JUST A SLIGHT CHANCE FOR
SHOWERS OVER THE WESTERN HALF OF THE STATE OVER THE WEEKEND.
TEMPERATURES DURING THE PERIOD WILL FEATURE HIGHS IN THE MID 80S TO
AROUND 90 DEGREES WITH OVERNIGHT LOWS GENERALLY IN THE MID 60S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 100 AM TUESDAY...
HIGH PROBABILITY THAT A PERIOD MVFR/IFR CONDITIONS WILL AFFECT THE
TERMINALS ACROSS CENTRAL NC TODAY AS A SERIES OF UPPER DISTURBANCES
AND AN APPROACHING SURFACE COLD FRONT INTERACT WITH A VERY MOIST AND
CONDITIONALLY UNSTABLE AIR MASS. CEILINGS IN THE LOW END MVFR/IFR
RANGE WILL BECOME DOMINATE AROUND DAYBREAK AND PERSIST THROUGH MUCH
OF THE MORNING. MEANWHILE SCATTERED SHOWERS WILL INITIALLY BE HIT-
AND-MISS THROUGH 09Z...BUT SHOULD BECOME MORE PROMINENT TOWARD
DAYBREAK IN THE PIEDMONT...AND BY MID-LATE MORNING IN VICINITY OF
KFAY AND KRWI
AVIATION CONDITIONS WILL BEGIN TO IMPROVE WEST-TO-EAST IN THE
AFTERNOON AS A MID LEVEL TROUGH CROSSES THE REGION. CEILINGS SHOULD
LIFT TO THE LOW END VFR CATEGORY BY EARLY-MID AFTERNOON IN THE
PIEDMONT AND BY LATE AFTERNOON ELSEWHERE. WITH AFTERNOON
HEATING...COULD SEE A FEW T-STORMS DEVELOP BUT CONFIDENCE NOT HIGH
ENOUGH AT THIS TIME TO MENTION IN THE TERMINAL FORECAST AS EXPECT
THE STORMS TO BE FAIRLY RANDOM.
A COLD FRONT WILL PROGRESSES EAST ACROSS THE REGION LATE TODAY AND
THIS EVENING. NWLY FLOW BEHIND THE BOUNDARY WILL USHER A DRIER MORE
STABLE AIR MASS...LEADING TO A PROLONGED PERIOD OF VFR CONDITIONS
WEDNESDAY THROUGH SATURDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...HARTFIELD/22
SHORT TERM...HARTFIELD
LONG TERM...RAH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1235 AM EDT TUE AUG 11 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE THIS EVENING. A COLD FRONT WILL
APPROACH THE AREA TUESDAY AND MOVE OFFSHORE WEDNESDAY. HIGH
PRESSURE BUILDS IN FROM THE NORTH FOR LATE WEEK. A COASTAL TROUGH
MAY AFFECT THE AREA BY THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1225 AM TUESDAY...A LOOK AT THE 3KM HRRR MODEL AND OTHER
HIGHER RESOLUTION MODELS INDICATE A MINIMAL CHANCE OF
PRECIPITATION ACROSS OUR CWA THROUGH 12Z. COULD MAKE A CASE FOR
THE FAR NORTHWESTERN COUNTIES HAVING A SMALL CHANCE WITH A FEW
SHOWERS OFF TO THE WEST AND NORTH OF RALEIGH AND WILL HAVE A
SLIGHT CHC POP FAR NORTHWEST WITH NOTHING ELSEWHERE OVERNIGHT.
NO CHANGES TO OVERNIGHT TEMPERATURES WITH LOW TEMPS IN THE LOWER
70S INLAND TO MID 70S ALONG THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM WEDNESDAY/...
AS OF 300 PM MONDAY...ADDITIONAL SHRT WV ENERGY WITH DIGGING SHRT
WV TROF ALONG WITH APPROACHING COLD FRONT AND DEW POINTS
INCREASING BACK INTO LOWER 70S WILL RESULT IN INCREASING SHOWER
AND ISOLATED TSTM THREAT DURING THE DAY. CONTINUED PREVIOUS FCST
TREND OF POPS INCREASING TO LIKELY ALL AREAS BY LATE AFTN. VEERING
WIND PROFILES AND INCREASING INSTABILITY SUPPORT ISOLATED SVR
THREAT...BUT LIMITED INSOLATION WILL LIKELY PRECLUDE WDSPRD DEEP
STRONG CONVECTION. MAX TEMPS MAINLY MID 80S.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 3 PM MON...COLD FRONT WILL PASS THROUGH TUESDAY NIGHT AND
OFF THE COAST WEDNESDAY. THE FRONT THEN BECOMES STATIONARY OVER
THE ATLANTIC OFFSHORE WATERS INTO THE WEEKEND AND DISSIPATES EARLY
NEXT WEEK. GFS/ECMWF IN AGREEMENT OVERALL AND USED A CONSENSUS
BLEND. THURSDAY AND FRIDAY NOW LOOK DRY WITH AVAILABLE MOISTURE
FOR CONVECTION REMAINING WELL OFF THE COAST. MOISTURE THEN DRIFTS
BACK TOWARD THE AREA THIS WEEKEND. HAVE REINTRODUCED POPS OVER
SOUTHERN AND EASTERN SECTIONS SATURDAY AND THROUGHOUT ON SUNDAY.
ONLY ISOLATED SEABREEZE ACTIVITY EXPECTED MONDAY.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 06Z WEDNESDAY/...
AS OF 1230 AM TUESDAY...EXTENSIVE HIGH CLOUDINESS ALONG WITH LOW-
LEVEL MIXING SHOULD KEEP ANY FOG AT BAY OVERNIGHT WITH VFR
CONDITIONS PREVAILING. THIS SHOULD CONTINUE THROUGH MOST OF THE
MORNING HOURS TUESDAY. DEVELOPING SHOWERS AND THUNDERSTORMS WILL
LEAD TO LOWER CEILINGS BY TUESDAY AFTERNOON INTO TUESDAY NIGHT
WITH SOME OCCASIONAL SUB-VFR CONDITIONS POSSIBLE.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM MON...SUB-VFR IN NUMEROUS SHOWERS AND THUNDERSTORMS
TUESDAY NIGHT. ACTIVITY ENDS FROM NORTHWEST TO SOUTHEAST WEDNESDAY
AS THE COLD FRONT MOVES OFF THE COAST. DRY/VFR WEDNESDAY NIGHT
THROUGH SATURDAY. LIGHT NORTH WIND WEDNESDAY. LIGHT NORTHEAST
THURSDAY AND FRIDAY...THEN EAST ON SATURDAY.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 1235 AM TUESDAY...LIGHT SE/S WINDS ACROSS THE COASTAL WATERS
AND SOUNDS WITH SEAS RUNNING 3 TO 5 FEET. THESE LIGHT WINDS
SHOULD CONTINUE OVERNIGHT AS HIGH PRESSURE GRADUALLY SHIFTS
OFFSHORE. WINDS WILL BECOME SW AND INCREASE TO 15-20 KT TUESDAY
WITH COLD FRONT APPROACHING FROM W.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM MON...SOUTHWEST FLOW TUESDAY NIGHT WITH WINDS/SEAS
REMAINING JUST BELOW SMALL CRAFT LEVELS. WINDS VEER TO WEST THEN
NORTHWEST WEDNESDAY AS THE FRONT MOVES OFF THE COAST. LOOSENING
PRESSURE GRADIENT WILL ALLOW WINDS AND SEAS TO DECREASE. LIGHT
NORTHEAST TO EAST FLOW WEDNESDAY NIGHT INTO SATURDAY WITH WINDS NO
HIGHER THAN 5-10 KNOTS AND SEAS 2-3 FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JBM
NEAR TERM...CTC
SHORT TERM...JBM
LONG TERM...HSA
AVIATION...BTC/CTC/HSA
MARINE...BTC/CTC/HSA
AREA FORECAST DISCUSSION
NWS NORMAN OK
313 AM CDT TUE AUG 11 2015
.DISCUSSION...
THIS MORNING... ACCAS DEVELOPMENT CONTINUES TO INCREASE ALONG THE
RED RIVER VALLEY IN RESPONSE TO A WEAK H850/H700 BOUNDARY AND
MOISTURE AXIS FROM THE SERN PANHANDLE INTO NRN TX. MESO GUIDANCE
FROM THE HRRR AND VARIOUS FLAVORS OF THE WRF (NMM...ARW ETC.) TRY TO
DEVELOP PRECIP ALONG THIS BOUNDARY IN ASSOCIATION WITH THE SMALL
COMPLEX OVER THE PANHANDLES. THROUGH 08Z... SCATTERED TO ISOLATED
DEVELOPMENT HAS SLOWLY INCREASED ACROSS PORTIONS OF THE EASTERN
PANHANDLES. WITH THIS IN MIND... THE HRRR MAY BE ON THE RIGHT
TRACK... BUT MOVING TOO FAST. CONFIDENCE IS GOOD THAT SOME ISOLATED
TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS WILL DEVELOP E/SE ALONG
THE INCREASING MID-LVEL THETA-E AXIS INTO SWRN OK/WRN N TX THROUGH
SUNRISE.
ANY ONGOING CONVECTION ACROSS SWRN OK/WRN N TX WILL SLOWLY DISSIPATE
THROUGH THE AFTN AS THE H500 RIDGE CONTINUES TO STRENGTHEN ALONG THE
ROCKIES. THERE ARE HINTS OF A WEAK MCV ON KAMA OVER NERN NM/NWRN TX
PH... THIS WILL CONTINUE TO LIFT NWRD... AND HAS BEEN REALIZED BY
THE 11/06Z RUN OF THE HRRR. OVERALL IT IS A MESSY MESOSCALE PATTERN
FOR THE SRN PLAINS AS THE RIDGE REMAINS CENTERED OVER THE SRN
ROCKIES. HOWEVER... WILL KEEP LOW CHC PRECIP/WX GOING FOR PORTIONS
OF WRN/NWRN OK THROUGH THE EVENING INTO EARLY WED. AS THE H500 RIDGE
CONTINUES TO SLIDE WEST... A MID-LVL THETA-E AXIS INCREASES ALONG
THE WRN OK/TX PH BORDER. WITH MODEST MID-LVL ASCENT... WOULD NOT BE
SURPRISED TO SEE SOME ISO/SCT DEVELOPMENT TONIGHT INTO EARLY WED.
FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND... MUCH QUIETER AND
MORE SEASONABLE WEATHER WILL BE ON TAP. THE H500 RIDGE REMAINS IN
CONTROL... SLOWLY BECOMING MORE POSITIVELY TILTED INTO THE WEEKEND.
TEMPS OVER THE NEXT SEVERAL DAYS WILL COOLER RELATIVE TO WHAT WE/VE
RECENTLY EXPERIENCED... WITH UPPER 80S TO LOWER 90S TODAY AND SLOWLY
CLIMBING BACK INTO THE MID TO UPPER 90S BY FRI INTO THE WEEKEND.
SCATTERED SHOWERS AND THUNDERSTORMS MAY MAKE A BRIEF APPEARANCE ON
FRI AS AN WEAK SHORT WAVE SKIRTS THE SRN PLAINS... BUT IT LOOKS...
AT THE MOMENT... TO BE AN OVERALL DRY END OF THE WEEK AND WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 88 67 / 10 10 0 10
HOBART OK 89 70 91 68 / 30 10 10 10
WICHITA FALLS TX 94 72 93 70 / 20 10 10 10
GAGE OK 85 66 88 67 / 20 20 20 20
PONCA CITY OK 87 65 88 67 / 0 0 10 0
DURANT OK 96 71 94 68 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1238 AM CDT TUE AUG 11 2015
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 944 PM CDT MON AUG 10 2015/
UPDATED THE ZONE FORECASTS AND GRIDS FOR TONIGHT. LEFT IN A 20
PERCENT CHANCE OF SHOWERS AND THUNDERSTORMS...ALTHOUGH THE ACTUAL
POP MAY BE LESS THAN THAT. A FEW SHOWERS AND THUNDERSTORMS REMAIN
UPSTREAM OVER SOUTHEASTERN MO AND SOUTHERN IL. THE HRRR CONTINUES
TO SHOW THE POSSIBILITY OF A FEW SHOWERS AND THUNDERSTORMS
TONIGHT IN ASSOCIATION WITH WEAK UPPER LEVEL DISTURBANCES. LOWERED
THE MINIMUM TEMPERATURES SOME IN MOST LOCATIONS BASED ON CURRENT
TEMPERATURES. ALSO INCLUDED AREAS OF FOG AS ANY DRIER AIR AT THE
LOWER LEVELS WILL BE SLOW IN MOVING INTO THE REGION.
JCL
&&
.DISCUSSION... /ISSUED 549 PM CDT MON AUG 10 2015/
UPDATED THE ZONE FORECASTS AND GRIDS TO ADJUST THE POPS TONIGHT
BASED ON THE LATEST MODELS AND CURRENT CONDITIONS. INCLUDED
CHANCE POPS FROM EAST CENTRAL AR TO MUCH OF NORTH MS WHERE THE
INSTABILITY IS GREATEST AND IS AHEAD OF A WEAK SURFACE BOUNDARY.
ELSEWHERE INCLUDED SLIGHT CHANCE POPS FOR THIS EVENING. ALSO
ADJUSTED THE SKY COVER GRIDS FOR TONIGHT...INDICATING PARTLY
CLOUDY SKIES IN THE ZONE FORECASTS.
JCL
DISCUSSION... /ISSUED 341 PM CDT MON AUG 10 2015/
A SHORTWAVE UPSTREAM ACROSS THE MIDDLE MISSISSIPPI VALLEY WILL
CONTINUE TO PUSH SOUTHEAST INTO THE SOUTHERN OHIO AND TENNESSEE
VALLEY TONIGHT. THIS WILL HELP TO ADVANCE A COLD FRONT SOUTH
ACROSS THE REGION OVERNIGHT. THE BEST FORCING ASSOCIATED WITH THE
SHORTWAVE SHOULD BE DIRECTED TO THE EAST OF OUR REGION WITH
EASTERN AREAS HAVING THE GREATEST POTENTIAL FOR CONVECTION
OVERNIGHT. EVEN IN THESE AREAS...SCATTERED COVERAGE AT BEST CAN BE
EXPECTED. OTHERWISE...FURTHER WEST...ISOLATED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE AS THE FRONT MOVES THROUGH. AHEAD
OF THE FRONT THIS EVENING...HOT AND HUMID CONDITIONS IN NORTH
MISSISSIPPI WILL SUPPORT A FEW MORE HOURS OF HEAT INDEX VALUES
GREATER THAN 105 DEGREES. THE HEAT ADVISORY WILL CONTINUE IN THESE
LOCATIONS THROUGH 8 PM CDT.
THE COLD FRONT SHOULD EXIT SOUTHERN SECTIONS ON TUESDAY MORNING
WITH LINGERING SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS. A
DRIER AIRMASS WILL BEGIN TO FILTER INTO THE REGION BY TUESDAY
AFTERNOON BRINGING AN END TO CONVECTIVE CHANCES AND BEGIN A SLOW
FALL OF SURFACE DEWPOINTS FROM NORTH TO SOUTH.
HIGH PRESSURE BUILDING INTO THE MID SOUTH WILL REMAIN IN PLACE
THROUGH MUCH OF THE REMAINDER OF THE WEEK. DRY WEATHER ALONG WITH
COOLER TEMPERATURES AND LOWER HUMIDITY VALUES CAN BE EXPECTED.
AN INVERTED SURFACE TROUGH AND AN INFLUX OF TROPICAL MOISTURE
SHOULD MOVE BACK INTO THE FORECAST AREA FROM THE EAST BY NEXT
WEEKEND. THIS WILL LIKELY BRING INCREASED HUMIDITY LEVELS ALONG
WITH INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS.
TEMPERATURES SHOULD ALSO RETURN TO NEAR SEASONAL VALUES FOR MID
AUGUST.
JLH
&&
.AVIATION...06Z TAF CYCLE
THUNDERSTORMS ACROSS NORTH ARKANSAS AND TENNESSEE SHOULD CONTINUE
TO WEAKEN AND DISSIPATE. PATCHY 2-5SM BR IS EXPECTED AT MKL
THIS MORNING WITH OTHERWISE VFR CONDITIONS OR THE NEXT 24 HRS.
NORTH TO NORTHEAST WINDS AROUND 5KT TONIGHT...5-10 TOMORROW.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1210 AM MDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1157 PM MDT MON AUG 10 2015
SIGNIFICANT FLASH FLOODING REMAINS A MAJOR CONCERN EARLY THIS AM
FOR THE I80 CORRIDOR BETWEEN KIMBALL AND SIDNEY. THUNDERSTORMS W/
VERY HEAVY RAINFALL HAVE LOCKED ONTO THE CHEYENNE RIDGE OVER THE
LAST SEVERAL HOURS...REMAINING NEARLY STATIONARY. DUAL-POL RADAR
ESTIMATES ARE WELL IN EXCESS OF 4 INCHES AND NUMEROUS REPORTS OF
SUBMERGED VEHICLES WERE RECEIVED FROM KIMBALL AFTER 11 PM. NEAR
TERM CONCERNS REVOLVE AROUND DOWNSTREAM AREAS ALONG LODGEPOLE
CREEK TOWARD SIDNEY. WILL NEED TO MONITOR VERY CLOSELY AS THE
LOW-LEVEL MOISTURE FEED SHOULD CONTINUE TO SUPPORT CONVECTIVE
MAINTENANCE FOR AT LEAST THE NEXT HOUR OR TWO. HAVE UPDATED THE
GRIDS TO INCLUDE MENTION OF HEAVY STORMS AND ADDITIONAL RAINFALL
IN EXCESS OF ONE INCH.
UPDATE ISSUED AT 938 PM MDT MON AUG 10 2015
GRIDDED FORECASTS UPDATED TO ADJUST POPS THE REST OF THIS EVENING
FOR SHOWERS AND THUNDERSTORMS OVER KIMBALL COUNTY NEBRASKA AND
A FEW SHOWERS OVER WESTERN NEBRASKA. EXPECT THESE SHOWERS TO BE
OVER BY MIDNIGHT. LATEST 00Z NAM AND HRRR INDICATING LOW CLOUDS
AND FOG ALONG THE SOUTHERN LARAMIE RANGE FROM CHEYENNE TO PINE
BLUFFS AND OVER THE SUMMIT LATER TONIGHT. /SAR
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
WE ARE STARTING TO SEE A FEW BUILDUPS ACROSS THE SOUTHERN LARAMIE
RANGE IN WYOMING AS WELL AS IN A ZONE OF DIFFERENTIAL HEATING ON
THE NORTH SIDE OF THE NORTH PLATTE RIVER VALLEY ACROSS THE
NEBRASKA PANHANDLE NORTH OF SCOTTSBLUFF. DONT THINK MOST STORMS
WILL GET OVERLY ROWDY THIS AFTERNOON AND EVENING...ALTHOUGH WITH
SBCAPES RUNNING IN THE 1200-1600 J/KG RANGE OVER THE PANHANDLE WE
COULD SEE A FEW STRONGER UPDRAFTS TO SUPPORT ISOLATED
STRONG/BRIEFLY MARGINALLY SEVERE STORMS...ALTHOUGH TYPICAL OF
AUGUST MIDLEVELS ARE FAIRLY WARM. MOST OF THE CONVECTION IS
EXPECTED TO FIRE ALONG AND JUST EAST OF THE LARAMIE RANGE THIS
AFTERNOON WITH ISOLATED STORMS EXPECTED THROUGH MID EVENING OVER
THE PANHANDLE.
RATHER AMPLIFIED UPPER RIDGE EXTENDS NORTH ACROSS THE CENTRAL AND
NORTHERN ROCKIES WITH OUR FORECAST AREA SEEING A GRADUAL INCREASE
IN MIDLEVEL MOISTURE FROM THE SOUTHWEST THROUGH MID WEEK. WILL SEE
SCATTERED STORMS TOMORROW AFTERNOON FIRE OVER THE SIERRA MADRE,
SNOWY AND SOUTHERN LARAMIE RANGE WITH ISOLATED STORMS EAST ONTO
THE PLAINS. BOTH THE GFS AND THE NAM SUPPORT THE NOTION OF A
SHORTWAVE RIDING NORTHEAST ACROSS OUR AREA WEDNESDAY AND THAT WILL
SUPPORT AN INCREASE IN POPS FOR WEDNESDAY AFTERNOON...ESPECIALLY
OUT WEST ALONG AND WEST OF THE LARAMIE RANGE WITH ISOLATED POPS
FARTHER EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 439 PM MDT MON AUG 10 2015
THERE IS THE POSSIBILITY OF LOWER FLIGHT CONDITIONS FOR SOME
AIRPORTS IN THE SOUTHERN PANHANDLE AND HERE AT CHEYENNE. LATEST
ALTERNATIVE HRRR AND SREF GUIDANCE IS SHOWING KSNY...KCYS AND
POSSIBLY KBFF GOING DOWN IN FOG AND STRATUS AFTER 09Z OR SO
TUESDAY MORNING. WILL TRY TO NARROW DOWN TIMING AND AIRPORTS ON
THE 06Z TAFS. BEST CHANCES LOOK TO BE HERE AT KCYS OVERNIGHT.
SOUTHEAST UPSLOPING WINDS TO CONTINUE THROUGH LATE MORNING TUESDAY
BEFORE TURNING MORE WESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 242 PM MDT MON AUG 10 2015
STILL EXPECTING NO MAJOR FIRE WEATHER CONCERNS THROUGH AT LEAST
WEDNESDAY WITH WIND GUSTS (AWAY FROM THUNDERSTORMS) EXPECTED TO
REMAIN BELOW 25 MPH AND HUMIDITIES AT OR ABOVE 20 PERCENT FOR MOST
LOCATIONS. WE WILL SEE ISOLATED TO SCATTERED THUNDERSTORMS THROUGH
MID WEEK IN THE AFTERNOON AND EARLY EVENING HOURS...WITH THE MAIN
THREATS FROM THESE BEING CLOUD TO GROUND LIGHTNING AND
GUSTY/ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...JG
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS PADUCAH KY
646 AM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 646 AM CDT TUE AUG 11 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 12Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
A FINAL BATCH OF SHOWERS WILL MOVE SOUTH THROUGH CARTER AND RIPLEY
COUNTIES IN MISSOURI EARLY THIS MORNING...THEN THE REMAINDER OF
THE SHORT TERM FORECAST IS DRY. THIS AFTERNOON...THE 00Z NAM IS
ATTEMPTING TO DEVELOP SOME SHALLOW CONVECTION. LOOKING AT ITS
SOUNDINGS FROM ACROSS THE REGION...IT APPEARS THERE WILL BE
SUBSTANTIAL COOLING IN THE 850MB TO 700MB LAYER...AND POSSIBLY
JUST ENOUGH LOW-LEVEL MOISTURE LEFT TO CREATE A SHALLOW LAYER OF
INSTABILITY BENEATH THE MID-LEVEL INVERSION. THE HRRR DEVELOPS A
FEW LIGHT SHOWERS...WHICH WOULD PROBABLY NOT EVEN MEASURE...SO
WILL KEEP THE FORECAST DRY FOR NOW.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY INTO
WEDNESDAY...AND THE FLOW ALOFT WILL BE NORTHWESTERLY AND FAIRLY
HEALTHY FOR THE MIDDLE OF AUGUST. NORTH WINDS UP TO 10KTS WILL MIX
DOWN EACH DAY...AND THAT WILL BRING COOLER AND MUCH DRIER AIR INTO
THE REGION. DEWPOINTS BY THE END OF THE DAY WEDNESDAY WILL BE IN
THE LOWER HALF OF THE 60S...AND UPPER 50S ARE EXPECTED BY DAYBREAK
THURSDAY IN THE EAST...AS THE SURFACE HIGH SETTLES OVERHEAD.
SHOULD SEE A DEFINITE TREND LOWER IN LOW TEMPERATURES FROM THIS
MORNING THROUGH WEDNESDAY NIGHT/THURSDAY MORNING...WITH WEAKENING
WINDS AND EVER DRIER AIR OVER THE REGION. HIGHS WILL TREND LOWER
TODAY AND WEDNESDAY AND THEN LEVEL OUT ON THURSDAY. DID NOT STRAY
FAR FROM THE CONSENSUS OF 00Z GUIDANCE FOR HIGHS OR LOWS THROUGH
THE PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
THE UPPER LEVEL RIDGE THAT HAS BEEN PERSISTENT ACROSS THE HIGH
PLAINS AND ROCKIES MOST OF THE SUMMER WILL REMAIN IN PLACE. THIS
RIDGE WILL BUILD NORTHEAST ACROSS THE GREAT LAKES REGION. AN UPPER
LEVEL TROUGH WILL MAINTAIN ITS PRESENCE OVER THE EASTERN STATES...
BUT UNDERGO A WEAKENING TREND AS IT SITS OVER THE APPALACHIANS. THE
NET RESULT FOR OUR REGION WILL BE A CONTINUATION OF DRY WEATHER.
SURFACE HIGH PRESSURE WILL REMAIN STATIONARY FROM THE CENTRAL PLAINS
TO THE OHIO VALLEY THROUGH THE WEEKEND. WITH LITTLE IN THE WAY OF
TEMPERATURE ADVECTION...HIGHS WILL REMAIN GENERALLY STEADY IN THE
UPPER 80S TO NEAR 90. BY EARLY NEXT WEEK...THE HIGH WILL RETREAT
SLOWLY TOWARD THE EAST...WHICH WILL PRODUCE A SOUTHWEST FLOW OF
SLIGHTLY HIGHER TEMPS AND DEW POINTS.
&&
.AVIATION...
ISSUED AT 646 AM CDT TUE AUG 11 2015
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION...RESULTING IN
NORTH WINDS THROUGHOUT THE PERIOD. A FEW GUSTS INTO THE TEENS WILL
BE POSSIBLE WITH AFTERNOON MIXING. A LITTLE MVFR FOG WILL BURN OFF
QUICKLY THIS MORNING. CONFIDENCE IS LOW IN THE FOG FORECAST FOR
TONIGHT. WINDS WILL WEAKEN OVERNIGHT...BUT STRONG MIXING TODAY
COUPLED WITH DRY ADVECTION SHOULD PREVENT FOG FORMATION IN MOST
LOCATIONS.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...DRS
LONG TERM...MY
AVIATION...DRS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
735 AM EDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE
ROCKIES/WRN PLAINS AND A TROF OVER ERN NAMERICA...RESULTING IN NNW
FLOW OVER THE UPPER GREAT LAKES EARLY THIS MORNING. UPSTREAM IN NRN
ONTARIO...SATELLITE IMAGERY AND SFC OBS SHOW LOW CLOUDS STEADILY
MOVING S AND NOW SPREADING OUT OVER FAR NRN LAKE SUPERIOR. THESE
CLOUDS WILL BE THE MAIN FCST ISSUE FOR TODAY. TO THE NW...FOCUSED
WAA REGIME IN MANITOBA IS PRODUCING SHRA/TSTMS EARLY THIS MORNING. A
SIMILAR SETUP MAY OCCUR LATE TONIGHT IN NRN ONTARIO/FAR NE MN AND
WRN LAKE SUPERIOR.
SATELLITE TRENDS AND GOOD AGREEMENT AMONG MODELS POINT TO A RAPID
INCREASE IN LOWER CLOUDS OVER NRN UPPER MI DURING THE NEXT SEVERAL
HRS. WITH OBS VERY SPARSE OVER NRN ONTARIO...TOUGH TO GAUGE HOW LOW
THE CLOUDS WILL BE AND WHETHER THERE MAY BE A RISK OF -DZ. THE ONLY
OB REPORTING CLOUDS IS AT GERALDTON...AND THE CIG THERE HAS BEEN
ABOVE 2KFT...NOT REALLY SUPPORTIVE OF -DZ. HOWEVER...THERE WAS ONE
OB THAT DID INDICATE -DZ. INITIALLY...PLANNED TO DROP PATCHY -DZ
MENTION OVER NCNTRL UPPER MI. HOWEVER...GIVEN THE ONE OB OF -DZ AND
THE POTENTIAL FOR THE WARMER WATERS OF SCNTRL LAKE SUPERIOR TO
FURTHER AID LOW CLOUD DEVELOPMENT IN FAVORABLE UPSLOPE FLOW...OPTED
TO RETAIN MENTION. 850MB THERMAL TROUGH OVER THE AREA TODAY SHOULD
ALLOW PLENTY OF STRATUS AND STRATOCU TO PERSIST WELL INTO THE AFTN
OVER MOST OF THE FCST AREA BEFORE STEADY CLEARING FROM THE W AND NW.
NNW WINDS GUSTING TO AROUND 25 MPH WILL BE AN ISSUE FOR MARINE
INTERESTS...ESPECIALLY ON LAKE SUPERIOR TO THE E OF THE HURON
ISLANDS AND ON NRN LAKE MICHIGAN. THE BREEZY NNW WINDS WILL MEAN
COOLEST CONDITIONS ALONG LAKE SUPERIOR OVER THE E WHERE LAKESIDE
TEMPS WILL BE IN THE LOW/MID 60S DURING THE DAY. MAX TEMPS IN THE
LOW/MID 70S ARE EXPECTED WELL INLAND...WARMEST FAR SCNTRL.
SFC HIGH PRES RIDGE MOVES OVER THE AREA TONIGHT...RESULTING IN
LIGHT/CALM WIND. WITH CLEAR SKIES FOR MUCH OF THE NIGHT...FAVORED
THE LOWER END OF AVBL GUIDANCE. INLAND FROM LAKE SUPERIOR...MANY
LOCATIONS SHOULD FALL TO THE 40S FOR MINS...WITH TRADITIONAL COLD
SPOTS TUMBLING TO AS LOW AS THE LWR 40S. LATE TONIGHT...THE SAME
FOCUSED WAA LEADING TO CONVECTION IN MANITOBA EARLY THIS MORNING
WILL BE POSITIONED IN NRN ONTARIO/FAR NE MN/WRN LAKE SUPERIOR. ALL
MODEL GUIDANCE POINT TOWARD REDEVELOPMENT OF CONVECTION IN THAT AREA
MOSTLY AFTER 06Z. WILL MAINTAIN SCHC POPS FOR SHRA/TSRA OVER NW LAKE
SUPERIOR INCLUDING ISLE ROYALE AFTER 08Z. WOULDN`T BE SURPRISED IF
LATER FCSTS NEED TO RAISE POPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 734 AM EDT TUE AUG 11 2015
MASS OF LOWER CLOUDS IS DROPPING S ACROSS LAKE SUPERIOR AND WILL
AFFECT KSAW MOST SIGNIFICANTLY. AT KSAW...EXPECT LOWER MVFR CIGS TO
DEVELOP IN THE NEXT COUPLE OF HRS. NOT OUT OF THE QUESTION THAT
THERE COULD BE A PERIOD OF IFR LATE THIS MORNING. KCMX WILL BE ON
THE WRN EDGE OF THE MORE SUBSTANTIAL LOW-LEVEL MOISTURE...AND AT
THIS POINT...IT DOES NOT APPEAR THAT CIGS WILL DROP TO MVFR. KIWD
WILL REMAIN VFR. THE CLOUDS WILL SCATTER AND CLEAR OUT FROM NW TO SE
DURING THE AFTN...LEAVING VFR CONDITIONS TO PREVAIL AT ALL TERMINALS
TONIGHT. WINDS WILL BECOME GUSTY TODAY...ESPECIALLY AT KSAW WHERE N
WINDS WILL GUST TO AROUND 20KT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WITH SFC HIGH PRES RIDGE APPROACHING FROM THE W...NNW WINDS WILL BE
FAIRLY BRISK OVER ERN LAKE SUPERIOR TODAY...WITH GUSTS FREQUENTLY
AROUND 20KT. OVER WRN LAKE SUPERIOR...WINDS WILL BE LIGHTER...
ESPECIALLY IN THE AFTN AS MESO HIGH PRES DEVELOPS OVER THE WRN LAKE.
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TONIGHT/WED
MORNING. WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW WED
AFTN OVER WRN LAKE SUPERIOR AS THE HIGH PRES RIDGE DRIFTS E. THESE
SW WINDS OF 10-20KT WILL CONTINUE INTO THU AHEAD OF COLD FRONT
APPROACHING FROM THE NW. DEPENDING HOW MUCH THE PRES GRADIENT
TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF GUSTS TO INCREASE
TO THE 20-30KT RANGE...ESPECIALLY AT THE HIGH OBS PLATFORMS. THE
STRONGEST GUSTS WOULD OCCUR OVER WRN LAKE SUPERIOR. WINDS WILL
DIMINISH AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON
FRI AS HIGH PRES BUILDS INTO THE UPPER LAKES. THESE LIGHTER WINDS
WILL LINGER INTO AT LEAST SAT MORNING BEFORE WINDS BEGIN TO INCREASE
AGAIN AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
622 AM CDT TUE AUG 11 2015
.DISCUSSION...
Issued at 314 AM CDT TUE AUG 11 2015
Slightly below normal temperatures and significantly lower humidity
throughout the region today will allow maximum heat indices to fall
nearly 15 degrees from yesterday`s max values, and will feel like a
brief reprieve from summer after days of sticky conditions. North
northeasterly surface winds will remain sustained at ~10-12 mph
through the day as the pressure gradient tightens in response to
surface high pressure building over north central KS, which will
also promote additional mixing out of low-level moisture on top of
the dry air advection already occurring. Felt that the RAP had the
right idea but was a little overdone in mixing to nearly 750 hPa, so
balanced between the RAP`s and HRRR`s warmer/drier solution with
consensus model solutions to bring highs into the mid 80s in most
locations this afternoon, and dewpoints into the lower 60s.
Upper-level high pressure over the desert southwest will expand and
bulge eastward over the next several days, keeping the forecast area
fully entrenched in northwest to northerly flow aloft through the
work week and into the weekend. At the surface, persistent high
pressure will very gradually drift and build to the southeast,
abating winds and mixing for Wednesday, then eventually allowing
weak southerly flow to return late Thursday or early Friday.
Sunshine should be abundant and precipitation chances nil this week
as the blocking upper high prevents even the most ambitious short-
wave energy from riding the length of the ridge and down into the
region. When the upper high finally begins to retreat southwest and
break down, ridging will edge northeastward into the upper Midwest,
bringing the thermal ridge closer to the forecast area and allowing
temperatures to return to the lower 90s for the weekend. Storm
chances don`t return until very late in the period when upper-level
flow finally flattens to zonal and a shortwave trough slides through
the central Plains, but timing of this feature continues to slow,
and its northern track could limit the possibility of precipitation
in the majority of the CWA.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday Morning)
Issued at 622 AM CDT TUE AUG 11 2015
VFR conditions and northerly winds will continue at all sites
through the TAF period.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Laflin
AREA FORECAST DISCUSSION
NWS GLASGOW MT
1001 AM MDT TUE AUG 11 2015
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH THURSDAY...
UPDATE...GOING FORECAST IN OVERALL GOOD SHAPE. ONLY TWEAKS WERE
TO TREND UP TEMPS A FEW DEGREES BASED ON THE LATEST MODEL
DATA...AND TO PUSH UP MENTION OF THUNDER AS THE HRRR AND SSEO ARE
FASTER WITH CONVECTIVE DEVELOPMENT ACROSS THE EAST THIS AFTERNOON.
GILCHRIST
PREVIOUS DISCUSSION...UPPER RIDGE WILL PERSIST ACROSS THE HIGH
PLAINS THROUGH THE END OF THE WEEK. THIS WILL RESULT IN VERY HOT
TEMPERATURES FOR THE NEXT FEW DAYS AS 850MB TEMPERATURES APPROACH
30C. THERE IS SOME POTENTIAL FOR ISOLATED THUNDERSTORMS ALONG THE
YELLOWSTONE VALLEY THIS EVENING...WITH ADDITIONAL STORMS MOVING
OFF THE SOUTHWEST MOUNTAINS AND INTO THE PLAINS LATE WEDNESDAY.
EBERT
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...
THE EXTENDED PERIOD GETS UNDERWAY THURSDAY NIGHT INTO FRIDAY WITH
A LARGE AND HIGHLY AMPLIFIED RIDGE OVER MUCH OF THE WESTERN U.S.
AND INTO ADJACENT CANADA...AND RIDGE AXIS TRANSLATING EAST INTO
THE DAKOTAS IN RESPONSE TO AN UPPER SHORTWAVE ENTERING THE PACIFIC
NORTHWEST UPSTREAM. RELATIVELY HIGH HEIGHTS OVER THE NORTHERN HIGH
PLAINS WILL LEND TO ANOTHER HOT DAY ACROSS NORTHEAST MONTANA FOR
FRIDAY. IN FACT...THE LATEST ECMWF HAS 850MB TEMPERATURES IN THE
LOWER 30S CELSIUS OVER MUCH OF THE AREA...EASILY SUPPORTIVE OF
HIGHS NEAR 100 DEGREES AT THE SURFACE WITH BOUNDARY LAYER MIXING.
THE APPROACHING SHORTWAVE WILL HAVE A COLD FRONT AT THE
SURFACE...AND WITH THE CWA MAY SEE PRE-FRONTAL WARMING FRIDAY
AFTERNOON AND A NEED TO GO TOWARD THE HIGHER END OF THE GUIDANCE
ENVELOPE. AS IT STANDS...WIDESPREAD LOWER 100S COULD RATIONALLY
BE FORECAST GIVEN THESE ARGUMENTS. DECIDED TO BE SOMEWHAT MORE
CONSERVATIVE AT THIS TIME HOWEVER DUE TO UNCERTAINTIES INVOLVING
INCREASING CLOUDINESS AHEAD OF THE APPROACHING FRONT.
WILL MAINTAIN INHERITED FORECAST THINKING IN TERMS OF POPS FOR
FRIDAY EVENING WITH SHOWERS/THUNDERSTORMS POSSIBLE WITH THE FRONT.
AT THIS TIME THOUGH DO NOTE THERE IS MORE SUPPORT WITH THE GFS
THAN THE ECMWF...WHICH IS A DRIER SOLUTION. THEREFORE...WHILE
KEEPING SCATTERED POPS IN PLACE SEEMS LIKE A GOOD IDEA...DID NOT
CHOOSE TO INCREASE POPS FURTHER GIVEN SPREAD IN MODEL SOLUTIONS.
FOR SATURDAY THE CWA WILL SEE MARKEDLY COOLER...THOUGH STILL WARM
TEMPERATURES WITH POST-FRONTAL ENVIRONMENT IN PLACE.CAA WILL HELP
MIX DOWN STRONGER WINDS TO THE SURFACE AND THIS DAY MAY NEED TO BE
MONITORED FOR LAKE WIND ADVISORY CRITERIA OUT ON FORT PECK LAKE.
SATURDAY NIGHT AND BEYOND...ENSEMBLE 500MB HEIGHTS SHOW INCREASING
SPREAD BUT BROAD AGREEMENT ON RETURNING RIDGE...SO TRENDED ON THE
DRIER SIDE WHILE MAINTAINING HIGHS IN THE 80S...RATHER SEASONABLE
FOR THIS TIME OF YEAR. MALIAWCO
&&
.AVIATION...
AN UPPER LEVEL SHORT-WAVE DISTURBANCE RIDING ACROSS THE TOP OF THE
HIGH PRESSURE RIDGE COULD INITIATE A ROUND OF THUNDERSTORMS THIS
AFTERNOON AND EVENING THAT WOULD AFFECT MAINLY TERMINAL AREAS
EAST OF KGGW. IF ANY THUNDERSTORMS DO DEVELOP THERE IS A CHANCE
FOR LOCALIZED HAIL AND GUSTY WINDS.
OTHERWISE TODAY WILL BE SKC INITIALLY THEN AFTERNOON & EVENING
MID LEVEL CLOUDS MAY DEVELOP. CLEAR SKIES WILL RETURN LATE TONIGHT
AND FOR WEDNESDAY.
WIND: TODAY...EAST TO SOUTHEAST AT 5-15KT. WEDNESDAY...LIGHT AND
VARIABLE.
SCT
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
935 AM MDT TUE AUG 11 2015
.UPDATE...
WEAK SHORTWAVE WAS WORKING INTO NORTHWEST WYOMING THIS MORNING.
THIS WAVE HAD GENERATED A FEW WEAK SHOWERS AND THUNDERSTORMS
EARLIER THIS MORNING OVER NORTHEAST IDAHO. ACTIVITY HAS DIED OUT
NOW WITH JUST SOME LEFT OVER CLOUDS. WILL LEAVE POPS OUT FOR THE
MORNING OVER THE HIGHER TERRAIN. THIS WAVE WILL ROUND THE TOP OF
THE RIDGE BUILDING IN THE AREA AND KICK OFF CONVECTION OVER THE
FAR EAST LATE TODAY. MID LEVEL CAP MAY BE ABLE TO HOLD CONVECTION
AT BAY THIS AFTERNOON WITH 700MB TEMPS ABOVE 12C. CAP MAY JUST BE
WEAK ENOUGH TO BREAK LATE THIS AFTERNOON FROM FALLON TO CARTER
COUNTIES. 12Z GFS AND NAM HOLD DEVELOPMENT OFF UNTIL THIS
EVENING...SO WILL LEAVE OUT FOR NOW. HRRR DOES FIRE ISOLATED
CONVECTION OFF OVER THE FAR EAST LATE THIS AFTERNOON...SO WILL
KEEP A CLOSE EYE ON THIS. THE REST OF THE FORECAST IN GOOD SHAPE
WITH HOT TEMPERATURES IN THE 90S. TWH
&&
.SHORT TERM...VALID FOR TDY AND WED...
UPPER LEVEL RIDGE CONTINUES TO STRENGTHEN OVER THE REGION WITH
500MB HEIGHTS APPROACHING 590DAM. DESPITE CLEAR SKIES...TEMPS ARE
STRUGGLING TO FALL AT SOME LOCATIONS PER SELY LOW LEVEL JET...SEE
3AM READING OF 70F AT MLS. THIS IS INDICATIVE OF THE HOT RIDGE
BUILDING IN. LOW LEVEL JET IS ADVECTING HIGH PLAINS MOISTURE INTO
OUR EAST WITH PWATS TO NEAR AN INCH PER LATEST ANALYSIS. THERE IS
ALSO A SMALL AREA OF WEAK CONVECTION NEAR POCATELLO ALONG A WEAK
SHORTWAVE LIFTING OUT OF THE EASTERN GREAT BASIN. WILL NEED TO
WATCH THIS BUT FOR NOW AM EXPECTING THIS ACTIVITY TO DIMINISH OVER
THE COMING HOURS BEFORE IT REACHES OUR CWA.
HOT WEATHER IS THE MAIN THEME THE NEXT TWO DAYS. EXPECT TEMPS WELL
INTO THE 90S TODAY...AND SOME LOCATIONS WILL REACH TRIPLE DIGITS
ON WEDNESDAY. WEAK SHORTWAVE/WIND SHIFT WILL ADVECT DRIER AIR INTO
OUR EAST TOMORROW...AND THIS SHOULD HELP TO DEEPEN MIXING WITHIN
AN AIRMASS SUPPORTIVE OF TRIPLE DIGIT HEAT...SO HAVE TWEAKED
EXPECTED TEMPS UP A BIT MORE. MILES CITY FORECAST HIGH OF 102F IS
PLENTY HOT BUT STILL 3 DEGREES SHORT OF THE AUG 12 RECORD.
BILLINGS HAS NOT SEEN 100 DEGREES YET IN 2015 BUT IT WILL GET
CLOSE TOMORROW. 700 TEMPS OF ABOUT +15C SUGGEST UPPER 90S WITHOUT
A PUSH OF WEST WINDS AT BILLINGS...SO WILL KEEP FORECAST HIGH AT
98F FOR THE AIRPORT.
THERE APPEARS TO BE A SMALL RISK OF TSTMS ACROSS OUR FAR EAST BY
THIS EVENING AS A WEAK SHORTWAVE ROUNDS THE RIDGE AND SLIDES
ACROSS OUR EAST...INTERACTING WITH MOISTURE PLUME WHICH IS
CURRENTLY MATERIALIZING...THOUGH THIS IS NOT OBVIOUS AS BUILDING
HEIGHTS AND MID LEVEL TEMPS WILL BE WORKING AGAINST THE CONVECTIVE
POTENTIAL. SHEAR AND INSTABILITY MAY BE ENOUGH FOR A STRONG STORM
IF ONE GETS GOING SO WILL NEED TO WATCH THIS. OTHERWISE EXPECT
ONLY WEAK TSTM ACTIVITY CONFINED TO OUR WESTERN HIGH TERRAIN...NOT
TOO DISSIMILAR TO WHAT WE SAW YESTERDAY.
THERE LOOKS TO BE A SLIGHTLY BETTER CHANCE OF DIURNAL TSTMS IN OUR
WEST ON WEDNESDAY COURTESY OF A DEEPER MONSOONAL SURGE AND
ADDITIONAL WEAK SHORTWAVE ENERGY. HAVE EXPANDED LOW POPS TO COVER
A BROADER AREA OF OUR WEST AND INCLUDING LOWER ELEVATIONS SUCH AS
LIVINGSTON...BIG TIMBER...HARLOWTON AND ROUNDUP. HAVE ALSO ADDED
MENTION OF GUSTY WINDS AS THIS WILL BE THE PRIMARY THREAT WITH ANY
CONVECTION PRODUCED BY THIS HOT AND DEEPLY MIXED AIRMASS. WILL
KEEP LALS AT 2 FOR LOWER ELEVATIONS.
AS FOR FIRE WEATHER...WILL CONTINUE TO ADVERTISE HOT WEATHER AND
MAINLY ISOLATED TSTMS THRU FRIDAY...WITH BREAKDOWN OF RIDGE AND
INCREASED WINDS ANTICIPATED BY THE END OF THE WEEK. JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
NOT MANY CHANGES IN THE EXTENDED PERIOD...AS MODELS ARE STILL IN
GOOD AGREEMENT WITH THE CONTINUED HOT WEATHER ACROSS THE NORTHERN
ROCKIES.
UPPER LEVEL RIDGE REMAINS FIRMLY IN PLACE UNTIL LONG WAVE TROUGH
MOVES ONSHORE ALONG THE PACIFIC COAST BY FRIDAY MORNING. AS THE
RIDGE BREAKS DOWN...ENERGY WILL MAKE ITS WAY SOUTHEAST FROM
ALBERTA AND SASKATCHEWAN. THIS WILL ALSO PULL A SURFACE FRONT
ACROSS THE TREASURE STATE DURING THE OVERNIGHT HOURS. THE FRONT
WILL BE COOL IN NATURE...AND WILL ACT TO BRING DOWN TEMPS THIS
WEEKEND...INTO THE MID 80S...WHICH WILL SEEM DOWNRIGHT PLEASANT
COMPARED TO EARLIER IN THE WEEK. THE TRICK WITH THE FRONTAL
PASSAGE WILL BE THE WINDS. EARLIER MODEL RUNS KEPT THE STRONGEST
LOW LEVEL WINDS TO THE NORTH OF THE BYZ CWA. BUT LATEST GFS RUN
SHOWS 850MB WINDS IN EXCESS OF 45 KNOTS OVER MUCH OF SOUTHEASTERN
MONTANA. SO...IN TURN...DECIDED TO BUMP UP SURFACE WIND VALUES
FROM FRIDAY NIGHT THROUGH SATURDAY MID DAY. FIRE WEATHER WILL BE
THE MAIN ISSUE OF CONCERN...WITH LITTLE TO NO WIDESPREAD RAIN AND
VERY LOW RH VALUES FOR THE SEVERAL DAYS LEADING UP TO THE FRONTAL
PASSAGE.
BY EARLY NEXT WEEK...THE UPPER LEVEL FLOW TURNS ZONAL...WITH A
FEW WAVES MOVING THROUGH THE FLOW. SINGER
&&
.AVIATION...
MOSTLY SUNNY SKIES WITH VFR CONDITIONS WILL PREVAIL TODAY.
HOWEVER...THERE WILL BE A SLIGHT CHANCE FOR A THUNDERSTORM AND
MVFR CONDITION OVER THE MOUNTAINS THROUGHOUT THE DAY...AS WELL AS
ALONG THE DAKOTA BORDERS LATE THIS AFTERNOON INTO THIS EVENING.
HOOLEY
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 096 064/098 067/096 066/097 062/087 057/082 057/085
0/U 01/B 11/B 11/B 11/B 11/U 11/B
LVM 095 057/094 059/093 058/093 055/085 050/083 050/082
0/U 02/T 21/B 11/B 11/B 11/U 11/U
HDN 098 061/101 063/099 064/099 061/088 055/087 057/087
0/U 00/G 10/B 11/B 11/B 11/U 11/B
MLS 098 065/102 068/100 069/100 066/090 057/086 059/088
0/U 10/G 11/B 02/T 21/B 22/T 21/U
4BQ 096 062/099 064/099 065/100 064/091 057/085 058/087
0/U 10/U 11/B 11/B 12/T 22/T 21/B
BHK 093 062/100 063/097 063/096 064/089 056/083 056/084
1/U 20/U 12/B 12/B 22/T 22/T 21/B
SHR 095 058/098 060/094 059/095 059/088 055/084 053/086
0/U 01/B 11/B 11/B 11/B 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1037 AM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1028 AM CDT TUE AUG 11 2015
HIGH PRESSURE DOMINATING AT THE SURFACE AND ALOFT THIS MORNING.
CLOUDS LIFTING NORTHEAST AND GENERALLY DISSIPATING EAST OF HIGHWAY
83. THE SURFACE AND UPPER RIDGE BUILDS EAST TODAY WHERE ISOLATED
TO SCATTERED CONVECTION WILL BE POSSIBLE IN THE PANHANDLE AND FAR
SOUTHWEST. NO SEVERE STORMS ARE ANTICIPATED WITH ISOLATED
THUNDERSTORMS THAT DO FORM CAPABLE OF HEAVY RAINFALL AND SMALL
HAIL. FORECAST GRIDS AND TEST PRODUCTS UPDATED TO REFLECT LOW
POPS IN THE WEST THROUGH THE AFTERNOON AND INTO TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 623 AM CDT TUE AUG 11 2015
A WARM FRONT STRETCHED NORTH AND SOUTH ACROSS WESTERN NEBRASKA
REMAINS STATIONARY TODAY AND TONIGHT. THE FRONT WILL BE THE FOCUS
FOR ISOLATED SHOWERS AND THUNDERSTORMS.
OTHERWISE VFR IS EXPECTED. STRATUS IS POSSIBLE LATE TONIGHT
ACROSS THE PANHANDLE. MVFR CIGS WOULD SPREAD FROM SOUTH TO NORTH
09Z-12Z.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KECK
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
HYDROLOGY...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
623 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 623 AM CDT TUE AUG 11 2015
A WARM FRONT STRETCHED NORTH AND SOUTH ACROSS WESTERN NEBRASKA
REMAINS STATIONARY TODAY AND TONIGHT. THE FRONT WILL BE THE FOCUS
FOR ISOLATED SHOWERS AND THUNDERSTORMS.
OTHERWISE VFR IS EXPECTED. STRATUS IS POSSIBLE LATE TONIGHT
ACROSS THE PANHANDLE. MVFR CIGS WOULD SPREAD FROM SOUTH TO NORTH
09Z-12Z.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
HYDROLOGY...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
615 AM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 11 2015
THE SHORT TERM FORECAST REMAINS FAIRLY QUIET THROUGH THE NEXT 24
HOURS...WITH DRY CONDITIONS AND VERY LITTLE CHANGES MADE TO THE
PREVIOUS FORECAST. AN UPPER LEVEL RIDGE REMAINS DOMINATE ACROSS THE
SOUTHERN HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL CLOSED LOW
TRUDGES OFF THE PACIFIC COASTLINE. AN OPEN WAVE HAS BEGUN TO SLIDE
EASTWARD ACROSS THE GREAT LAKES REGION. THE RIDGE AXIS IN THE MID
LEVELS IS SLIGHTLY MORE PRONOUNCED AND AMPLIFIED ACROSS THE FRONT
RANGE. ALONG THIS RIDGE AXIS...RETURN FLOW COMBINED WITH WARM AIR
ADVECTION HAS ALLOWED MOISTURE TO SURGE NORTHWARD ALONG THE FRONT
RANGE. AT THE SURFACE HIGH PRESSURE HAS SHIFTED ACROSS THE CENTRAL
PLAINS. LATEST OBS REFLECT THIS FEATURE AS MOST AIRPORT WINDS ARE
LIGHT TO CALM.
ALTHOUGH THIS IS NOT REFLECTED IN THE FORECAST...THERE ARE SOME
CONCERNS ABOUT PATCHY FOG DEVELOPMENT THIS MORNING. EVEN THOUGH
DEWPOINTS ARE LOWER THAN PREVIOUS DAYS...TEMPERATURES ARE ALSO
SLIGHTLY COOLER. AT THE PRESENT TIME...RELATIVE HUMIDITY VALUES ARE
ABOVE 90 PERCENT IN MOST AREAS. MODEL SOLUTIONS SUCH AS THE
NAM...RAP...AND HRRR ALL SUGGEST LOWERED VISIBILITIES ESPECIALLY FOR
LOCATIONS WEST OF 281...MAINLY ALONG THE SURFACE RIDGE AXIS. SINCE
THIS WILL LIKELY BE PATCHY IN NATURE...WILL CONTINUE TO MONITOR
LATEST TRENDS BEFORE INTRODUCING INTO GRIDS.
THE REST OF TODAY LOOKS TO REMAIN QUIET AS THE SURFACE RIDGE SLIDES
THROUGH THE AREA. LIGHT WINDS ARE EXPECTED AND HIGH TEMPERATURES
SHOULD TOP OUT NEAR NORMAL WITH HIGHS IN THE MID 80S FOR MOST
LOCATIONS. FURTHER WEST...A SMALL DISTURBANCE WILL DEVELOP ALONG THE
FRONT RANGE...AND COMBINED WITH MOISTURE AND WARM AIR ADVECTION WILL
LIKELY SPAWN THUNDERSTORMS. 0Z MODEL SOLUTIONS PULLED POPS BACK
FURTHER WEST AND THUS WENT AHEAD AND REMOVED ANY MENTION OF
THUNDERSTORMS FROM WESTERN ZONES TUESDAY NIGHT. HOWEVER...WOULD NOT
BE SURPRISED TO SEE A STORM MAKE A RUN FOR THE WESTERN ZONES DURING
THIS TIME FRAME. EVEN THE 6Z NAM...HAS NOW REVERTED BACK TO POPS IN
NORTH CENTRAL KANSAS BY EARLY MORNING WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 11 2015
AN UPPER RIDGE OF HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE
ACROSS THE INTERIOR CONUS THROUGH THE WORKWEEK. THE PATTERN WILL BE
BLOCKY AT THE START WITH CLOSED LOWS IN THE PACIFIC OCEAN OFF THE
COAST OF CALIFORNIA AND ANOTHER TROUGH ALONG THE EAST COAST. UNDER
THE INFLUENCE OF THE RIDGE...PRECIPITATION CHANCES WILL BE
NEGLIGIBLE UNTIL THE WEEKEND TIME FRAME WHEN THE WESTERN LOW LIFTS
OUT AND BREAKS DOWN THE INTERIOR CONUS RIDGE. ALTHOUGH THE FORECAST
REMAINS DRY UNTIL SATURDAY NIGHT WILL NEED TO KEEP AN EYE ON
CONVECTION WHICH DEVELOPS ALONG THE HIGHS PLAINS AS ACTIVITY MAY TRY
TO WORK INTO OUR WESTERN ZONES.
THE PATTERN CHANGE ARRIVES OVER THE WEEKEND AS THE AFOREMENTIONED
WESTERN SYSTEM LIFTS OUT AND CROSSES THE NORTHERN CONUS. AN
ASSOCIATED COLD FRONTAL BOUNDARY ADVANCES SOUTH FROM THE DAKOTAS
LATE SATURDAY WITH CHCS FOR TSTMS RETURNING AS FRONT ARRIVES. THE
ECMWF IS SLOWER WITH BOUNDARY PROGRESSION THAN THE GFS BUT HARD TO
PINPOINT THE DETAILS THIS FAR OUT. THE BOUNDARY IS PROGGED TO STALL
OR MEANDER ACROSS OUR REGION INTO EARLY NEXT WEEK AND WITH BOUNDARY
IN THE AREA CHANCES FOR STORMS CONTINUE. TEMPERATUREWISE...READINGS
WILL BE TYPICAL OF SUMMER WITH HIGHS IN THE 80S TO LOW 90S...WITH
LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 612 AM CDT TUE AUG 11 2015
WHILE VFR CONDITIONS ARE FORECAST FOR THE TAF SITES THROUGHOUT THE
PERIOD...SOME UNCERTAINTY EXISTS REGARDING CEILINGS THIS MORNING.
A FEW SHOWERS HAVE DEVELOPED ACROSS SOUTHWEST NEBRASKA WHICH HAVE
RESULTED IN BKN OR OVC CEILINGS NEAR 5000 FT. DEBATED ON ADDING
AT LEAST A MENTION OF THIS CEILING IN THE KEAR TAF...BUT
CONFIDENCE IS NOT HIGH THESE CEILINGS WILL ACTUALLY MAKE IT THIS
FAR EAST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...FAY
AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
907 AM EDT TUE AUG 11 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER PLAINS WILL GRADUALLY MOVE UP THE
OHIO VALLEY THROUGH THURSDAY. A WEAK COLD FRONT SHOULD MOVE
THROUGH THE REGION LATE FRIDAY THEN HIGH PRESSURE WILL REBUILD
OVER THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/... AN UPPER LEVEL TROUGH OVER THE AREA
WILL KEEP CONDITIONS UNSETTLED THRU TONIGHT. BREAKS IN CLOUDS WILL
OCCUR ESPECIALLY OVER THE WEST HALF OF THE AREA.
THE NEAR TERM...HIGH RES MODELS...ESPECIALLY THE HRRR INDICATE A
POTENTIAL FOR LIGHT SHRA TODAY OVER THE EAST 2/3 OF THE CWA. AN
UPPER S/W DROPPING INTO THE AREA TONIGHT WILL BRING AN ADDITIONAL
THREAT FOR LIGHT SHRA WITH EMPHASIS FOR THE SNOWBELT AS LAKE EFFECT
CONDITIONS BECOME A LITTLE MORE FAVORABLE.
TEMPS WILL BE COOLER TODAY AND TONIGHT AS WEAK COLD ADVECTION OCCURS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
EARLY WEDNESDAY LAKE INDUCED RAIN SHOWERS COULD BECOME A BIT MORE
PERSISTENT IN RESPONSE TO THE LAST BIT OF ENERGY THAT WILL DROP OUT
OF THE MAIN TROF. THESE SHOWERS WILL PRIMARILY AFFECT PRIMARY AND
SECONDARY SNOWBELT COUNTIES. DECREASE POPS THROUGH THE REST OF THE
DAY AS THE HIGH BECOMES BETTER ESTABLISHED. EVEN THOUGH THE MODELS
SHOW PRECIP OVER THE LAKE MICHIGAN AREA LATE WEDNESDAY INTO
THURSDAY TRENDING ESE TOWARDS NORTHERN OHIO...KEPT THE FORECAST
DRY GIVEN LIMITED MOISTURE. A BETTER CHANCE FOR RAIN WILL COME
FRIDAY MORNING WITH A WEAK COLD FRONT THAT WILL LIKELY DISSIPATE
ACROSS NORTHERN OHIO. TEMPERATURES WILL RUN ABOUT 10 DEGREES BELOW
NORMAL ON WEDNESDAY THEN START TO MODERATE SOME ON THURSDAY AS WE
GET INTO SOME WEAK WAA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A WEAKENING COLD FRONT SHOULD JUST ABOUT BE OUT OF THE
AREA AT THE START OF THE PERIOD. ALL OF THE GUIDANCE CONTINUES TO
SUGGEST THAT THERE COULD BE SOME RESIDUAL SHOWER ACTIVITY ON
SATURDAY IN THE WAKE OF THIS FRONT. HAVE ACTUALLY BUMPED UP PRECIP
CHANCES A LITTLE AS BOTH THE ECMWF AND GFS ARE NOW SHOWING PRECIP.
THE SECOND HALF OF THE WEEKEND WILL BE QUIET AS HIGH PRESSURE
BRIEFLY BUILDS OVER THE REGION. ANOTHER COLD FRONT WILL APPROACH
FROM THE NORTHWEST AT THE END OF THE PERIOD. ALREADY HAVE CHANCE
WORDING IN THE MONDAY FORECAST AND THAT SEEMS REASONABLE.
TEMPERATURES DURING THE PERIOD WILL AVERAGE A COUPLE OF DEGREES
ABOVE NORMAL.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THE AMOUNT OF IFR WEATHER ACROSS THE AREA HAS DIMINISHED AS
SLIGHTLY DRIER AIR HAS WORKED IN FROM THE NW. A GRADUAL SLOW
IMPROVEMENT OF CIG HEIGHTS IS EXPECTED THIS MORNING. ALL AREAS
SHOULD BE VFR BY 18Z. EXPECTED WESTERN AREAS TO BECOME SCT THIS
AFTERNOON BUT STRATO CUMULUS CIGS WILL PERSIST TILL LATE TODAY IN
THE EAST. NW WINDS HAVE ALREADY STARTED TO PICK AND WINDS MUCH OF
THE DAY WILL BE IN THE 10 TO 15 KNOT RANGE. THE FLOW WILL BECOME N
TOWARD EVENING AND THEN WEAKEN.
OUTLOOK...A CHANCE OF NON-VFR CONDITIONS FRIDAY NIGHT INTO
SATURDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
LIGHT NORTHWEST TO NORTH WINDS WILL INCREASE TODAY.
EXPECT PEAK SUSTAINED WINDS TO BE ABOUT 15 KNOTS WHICH IS JUST BELOW
WHAT IS NEEDED FOR SMALL CRAFT CONDITIONS. DAY CREW WILL HAVE TO
KEEP ON EYE ON THINGS BUT WILL HOLD OFF ON HEADLINES FOR NOW.
NORTHERLY WINDS WILL CONTINUE THROUGH LATE WEDNESDAY AND THEN BECOME
SOUTHWESTERLY ON THURSDAY AS HIGH PRESSURE MOVES OFF TO THE
SOUTHEAST. MAINLY SOUTHWEST FLOW IS THEN EXPECTED TILL ANOTHER COLD
FRONT CROSSES THE LAKE ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAYERS
NEAR TERM...MAYERS/ADAMS
SHORT TERM...ADAMS/MAYERS
LONG TERM...KUBINA
AVIATION...KUBINA
MARINE...KUBINA
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
645 AM CDT TUE AUG 11 2015
.AVIATION...11/12Z TAF ISSUANCE...
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ACROSS
WRN OK AND WRN N TX THROUGH THE MORNING... LINGERING INTO THE
AFTERNOON. THIS ACTIVITY WILL IMPACT WRN OK/WRN N TX TAF SITES
AT VARIOUS TIMES THROUGH THE MORNING. OVERALL... MOST SITES WILL
REMAIN AT VFR. HOWEVER... KGAG/KWWR IN NWRN OK WILL HOLD NEAR OR
AT IFR CEILINGS THROUGH THE MORNING. WINDS WILL REMAIN OUT OF THE
NORTHEAST THROUGH THE PERIOD.
JTK
&&
.PREV DISCUSSION... /ISSUED 313 AM CDT TUE AUG 11 2015/
DISCUSSION...
THIS MORNING... ACCAS DEVELOPMENT CONTINUES TO INCREASE ALONG THE
RED RIVER VALLEY IN RESPONSE TO A WEAK H850/H700 BOUNDARY AND
MOISTURE AXIS FROM THE SERN PANHANDLE INTO NRN TX. MESO GUIDANCE
FROM THE HRRR AND VARIOUS FLAVORS OF THE WRF (NMM...ARW ETC.) TRY TO
DEVELOP PRECIP ALONG THIS BOUNDARY IN ASSOCIATION WITH THE SMALL
COMPLEX OVER THE PANHANDLES. THROUGH 08Z... SCATTERED TO ISOLATED
DEVELOPMENT HAS SLOWLY INCREASED ACROSS PORTIONS OF THE EASTERN
PANHANDLES. WITH THIS IN MIND... THE HRRR MAY BE ON THE RIGHT
TRACK... BUT MOVING TOO FAST. CONFIDENCE IS GOOD THAT SOME ISOLATED
TO WIDELY SCATTERED SHOWERS/THUNDERSTORMS WILL DEVELOP E/SE ALONG
THE INCREASING MID-LVEL THETA-E AXIS INTO SWRN OK/WRN N TX THROUGH
SUNRISE.
ANY ONGOING CONVECTION ACROSS SWRN OK/WRN N TX WILL SLOWLY DISSIPATE
THROUGH THE AFTN AS THE H500 RIDGE CONTINUES TO STRENGTHEN ALONG THE
ROCKIES. THERE ARE HINTS OF A WEAK MCV ON KAMA OVER NERN NM/NWRN TX
PH... THIS WILL CONTINUE TO LIFT NWRD... AND HAS BEEN REALIZED BY
THE 11/06Z RUN OF THE HRRR. OVERALL IT IS A MESSY MESOSCALE PATTERN
FOR THE SRN PLAINS AS THE RIDGE REMAINS CENTERED OVER THE SRN
ROCKIES. HOWEVER... WILL KEEP LOW CHC PRECIP/WX GOING FOR PORTIONS
OF WRN/NWRN OK THROUGH THE EVENING INTO EARLY WED. AS THE H500 RIDGE
CONTINUES TO SLIDE WEST... A MID-LVL THETA-E AXIS INCREASES ALONG
THE WRN OK/TX PH BORDER. WITH MODEST MID-LVL ASCENT... WOULD NOT BE
SURPRISED TO SEE SOME ISO/SCT DEVELOPMENT TONIGHT INTO EARLY WED.
FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND... MUCH QUIETER AND
MORE SEASONABLE WEATHER WILL BE ON TAP. THE H500 RIDGE REMAINS IN
CONTROL... SLOWLY BECOMING MORE POSITIVELY TILTED INTO THE WEEKEND.
TEMPS OVER THE NEXT SEVERAL DAYS WILL COOLER RELATIVE TO WHAT WE/VE
RECENTLY EXPERIENCED... WITH UPPER 80S TO LOWER 90S TODAY AND SLOWLY
CLIMBING BACK INTO THE MID TO UPPER 90S BY FRI INTO THE WEEKEND.
SCATTERED SHOWERS AND THUNDERSTORMS MAY MAKE A BRIEF APPEARANCE ON
FRI AS AN WEAK SHORT WAVE SKIRTS THE SRN PLAINS... BUT IT LOOKS...
AT THE MOMENT... TO BE AN OVERALL DRY END OF THE WEEK AND WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 89 68 88 67 / 10 10 0 10
HOBART OK 89 70 91 68 / 30 10 10 10
WICHITA FALLS TX 94 72 93 70 / 20 10 10 10
GAGE OK 85 66 88 67 / 20 20 20 20
PONCA CITY OK 87 65 88 67 / 0 0 10 0
DURANT OK 96 71 94 68 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
625 AM PDT TUE AUG 11 2015
UPDATED AVIATION AND FIRE DISCUSSIONS.
.DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSPEHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY. FIRST...WE
HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF MOISTURE AND
INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS THERE.
ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY ASSIST IN
FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
TUESDAY NIGHT...THE LATEST NAM UPPER LEVEL INSTABILITY PARAMETERS
SUCH AS MODIFIED TOTAL TOTALS AND 700MB-500MB CAPE SHOW SOME
POTENTIAL FOR THUNDERSTORMS FOR NORTHERN DOUGLAS COUNTY TOWARDS THE
COAST...AND THIS BEARS WATCHING FOR FUTURE TRENDS. EARLIER MODELS
SHOWED LESS FAVORABLE CONDITIONS...SO SHOWERS ARE IN THE CURRENT
FORECAST FOR TUESDAY NIGHT.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...FOR THE 11/12Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL PERSIST THROUGH MID-MORNING (CLEARING AROUND 16-
18Z) EXCEPT FOR SOME LINGERING LOW CIGS POSSIBLE NEAR KBOK INTO THE
AFTERNOON. IFR CIGS ARE EXPECTED TO RETURN TO THE COAST THIS
EVENING AROUND 04Z. INLAND...VFR CONDITIONS WILL PREVAIL THROUGH
THIS MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN SMOKE. A FEW
THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING WEST OF THE CASCADES,
MAINLY NEAR THE COAST. SOUTHEAST STEERING WINDS ARE EXPECTED WITH
ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING FROM THE SOUTHERN
OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND FROM WESTERN
SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES. STORMS MAY BRING
ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF HIGHER TERRAIN. -CC
&&
.MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
&&
.FIRE WEATHER...UPDATED 600 AM PDT TUESDAY 11 AUGUST 2015...A SLIGHT
CHANCE OF THUNDERSTORMS AND SHOWERS IS POSSIBLE WEST OF THE CASCADES
THIS MORNING, MAINLY NEAR THE COAST. THEN MODELS SHOW SOME MID LEVEL
MOISTURE, INSTABILITY, AND DISTURBANCES ALOFT MOVING INTO THE AREA
THIS AFTERNOON AND EVENING. THIS IS EXPECTED TO BRING MAINLY
ISOLATED STORMS TO AREAS FROM THE CASCADES WEST AND INTO NORTHERN
KLAMATH COUNTY, EXCEPT FOR SCATTERED THUNDERSTORMS WHICH ARE
EXPECTED IN EASTERN PORTIONS OF FIRE WEATHER ZONE 617 AND FAR
NORTHERN PORTIONS OF FIRE WEATHER ZONE 623 LATE THIS AFTERNOON AND
THIS EVENING. OVERALL THERE IS MODERATE CONFIDENCE FOR SCATTERED
STORMS IN THESE AREAS LATE TODAY AND THIS EVENING. OF NOTE, MODELS
ARE TRACKING THIS MORNING`S STORMS WELL COMPARED TO YESTERDAYS
EVENT. MODELS SHOW GOOD INSTABILITY AND UPPER LEVEL SUPPORT FOR
STORMS IN ZONES 617 AND NORTHERN 623. UNCERTAINTY IS MAINLY WITH THE
TRACK OF ANY DISTURBANCES INTO THE AREA AND WHETHER THEY PUSH
FURTHER NORTH. FOR AREAS WEST OF THE CASCADES, THE BEST CHANCE FOR
ISOLATED STORMS TO DEVELOP THIS AFTERNOON INTO THIS EVENING IS IN
WESTERN SISKIYOU COUNTY NORTHWARD INTO WESTERN JOSEPHINE AND EASTERN
CURRY COUNTIES. ALSO THE STORMS THAT DEVELOP IN THE OREGON CASCADES
MAY MOVE EAST-NORTHEAST AND INTO NORTHERN JACKSON AND CENTRAL
DOUGLAS COUNTY DURING THE EVENING.
ON WEDNESDAY, CONDITIONS ARE FORECAST TO BE MORE STABLE AND LESS
FAVORABLE FOR THUNDERSTORMS. THEN AS THE UPPER LOW NEARS THE COAST
ON THURSDAY, GRADUALLY MOVING ONSHORE THURSDAY EVENING AND NIGHT,
EXPECT INCREASED CHANCES FOR A MIX OF SHOWERS AND THUNDERSTORMS OVER
THE AREA. HOWEVER, MODELS ARE SHOWING CONSIDERABLE VARIABILITY ON
THE TRACK OF THE LOW AND HOW QUICKLY IT WILL PUSH INLAND. SO
CONFIDENCE IS LOWER ON THE DETAILS OF THE FORECAST FOR THURSDAY.
AS THE UPPER LOW REMAINS OFF THE COAST, GUSTY SOUTH WINDS WILL
CONTINUE OVER EASTERN PORTIONS OF THE AREA THROUGH THURSDAY...WHEN
IT MAY BE ESPECIALLY WINDY ON THE EAST OF THE CASCADES AS THE UPPER
LOW GRADUALLY MOVES ONSHORE. ALSO GUSTY SOUTH WINDS ARE ALSO LIKELY
IN THE SHASTA VALLEY TODAY AND AGAIN ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AFTERNOON. DAYTIME RELATIVE HUMIDITIES WILL INCREASE
SLIGHTLY ON THURSDAY.
AFTER THE TROUGH MOVES INLAND...OFFSHORE LOW LEVEL FLOW WILL DEVELOP
OVER THE COAST RANGE FRIDAY NIGHT INTO SATURDAY NIGHT. THIS MAY
BRING MODERATE RECOVERIES WITH LOCALLY POOR RECOVERIES POSSIBLE FOR
THE RIDGES, ESPECIALLY FOR THOSE IN THE COASTAL RANGES, SISKIYOUS
AND FOR THE MOUNTAINS IN WESTERN SISKIYOU COUNTY. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/NSK/DW
AREA FORECAST DISCUSSION
NWS MEDFORD OR
350 AM PDT TUE AUG 11 2015
.DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSPEHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY. FIRST...WE
HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF MOISTURE AND
INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS THERE.
ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY ASSIST IN
FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
TUESDAY NIGHT...THE LATEST NAM UPPER LEVEL INSTABILITY PARAMETERS
SUCH AS MODIFIED TOTAL TOTALS AND 700MB-500MB CAPE SHOW SOME
POTENTIAL FOR THUNDERSTORMS FOR NORTHERN DOUGLAS COUNTY TOWARDS THE
COAST...AND THIS BEARS WATCHING FOR FUTURE TRENDS. EARLIER MODELS
SHOWED LESS FAVORABLE CONDITIONS...SO SHOWERS ARE IN THE CURRENT
FORECAST FOR TUESDAY NIGHT.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...FOR THE 11/06Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE OVERNIGHT THEN PERSIST THROUGH
MID-MORNING (AROUND 18Z) TUESDAY. INLAND...VFR CONDITIONS WILL
PREVAIL THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN
SMOKE. A FEW THUNDERSTORMS ARE POSSIBLE OVERNIGHT WEST OF THE
CASCADES CONTINUING INTO THE MORNING. SOUTHEAST STEERING WINDS ARE
EXPECTED WITH ISOLATED THUNDERSTORMS TUESDAY AFTERNOON AND EVENING
FROM THE SOUTHERN OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND
FROM WESTERN SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES.
STORMS MAY BRING ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF
HIGHER TERRAIN. -DW
&&
.MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/NSK/DW
AREA FORECAST DISCUSSION
NWS MEDFORD OR
330 AM PDT TUE AUG 11 2015
.DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSPEHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY. FIRST...WE
HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND NORTH OF
CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF MOISTURE AND
INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS THERE.
ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY ASSIST IN
FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
&&
.AVIATION...FOR THE 11/06Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE OVERNIGHT THEN PERSIST THROUGH
MID-MORNING (AROUND 18Z) TUESDAY. INLAND...VFR CONDITIONS WILL
PREVAIL THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN
SMOKE. A FEW THUNDERSTORMS ARE POSSIBLE OVERNIGHT WEST OF THE
CASCADES CONTINUING INTO THE MORNING. SOUTHEAST STEERING WINDS ARE
EXPECTED WITH ISOLATED THUNDERSTORMS TUESDAY AFTERNOON AND EVENING
FROM THE SOUTHERN OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND
FROM WESTERN SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES.
STORMS MAY BRING ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF
HIGHER TERRAIN. -DW
&&
.MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
NSK/NSK/DW
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1027 AM EDT TUE AUG 11 2015
.SYNOPSIS...
A FRONTAL SYSTEM WILL MOVE EAST OF THE REGION TODAY. COOLER AND
DRIER AIR WILL FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL
REBOUND LATE THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE
MID MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT MID MORNING THE COLD FRONT WAS STILL WEST OF HARRISBURG MOVING
THROUGH THE LOWER SUSQ VALLEY. BREAKS IN THE CLOUDS ARE ALLOWING
SOME AIRMASS RECOVERY WITH CAPES STARTING TO INCREASE OVER THE SERN
ZONES. WHILE THE HRRR DOES TRY AND FIRE UP A SMALL CONVECTIVE
CLUSTER OVER LANCASTER AND ADAMS COUNTY OVER THE NEXT 1-3
HOURS...I STILL THINK THE SEVERE POTENTIAL WILL BE LIMITED. NEAR
TERM GUIDANCE SHOWS COLD/DRY ADVECTION DEVELOPING IN THE LOWER
LEVELS AND THE RAP INDICATES WE WILL SEE LAYER AVERAGE NEGATIVE
THETA-E ADVECTION IN THE LOW LEVELS OVERSPREAD THE AREA BY LATE
MORNING/EARLY AFTERNOON.
WITH MARGINAL INSTABILITY OVER MOST OF THE AREA COURTESY OF
FALLING UPPER HEIGHTS...WE CANNOT RULE OUT A STRAY SHOWER OR
THUNDERSTORMS TODAY BUT THE OVERALL PATTERN SUPPORTS DRYING
CONDITIONS FOR THE REGION FOR THE REST OF THE DAY.
HIGHS WILL RANGE FROM THE LOWER 70S NORTH TO THE LOWER 80S
SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
CONDITIONS IMPROVE TONIGHT AS A CONTINUAL FEED OF PROGRESSIVELY
DRIER PW ARRIVES ON NORTHWEST FLOW. FAIRLY CYCLONIC UPPER FLOW AND DEEPENING
COLD AIR ALOFT WILL KEEP ISOLD TO LOW CHC POPS IN THE FORECAST
TONIGHT AND WEDNESDAY...BUT RAIN WILL BE SHORT-LIVED AND
GENERALLY LIGHT GIVEN DRY AIR MASS OVER THE REGION. MINS WILL
RANGE FROM THE MID 50S NORTH TO THE MID 60S SOUTHEAST...WHILE
HIGHS RANGE FROM NEAR 70 NORTHWEST TO AROUND 80 SOUTHEAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
BOTH THE GEFS AND THE NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW
NORMAL 850 MB TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...
NORTHWEST FLOW ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS
WEDNESDAY AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON THURSDAY...
BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL BECOME
MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS THE
ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A MORE
WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE COLD FRONT HAS YET TO CLEAR THE LOWER SUSQ VALLEY...BUT MOST
OF THE FORECAST AREA IS NOW INTO A DRIER WEST-NORTHWEST FLOW AND
WILL CONTINUE TO SEE COOLER AND DRIER AIR SLIP INTO THE REGION.
WIDESPREAD MVFR/IFR IN THE POST FRONTAL ENVIRONMENT WILL SLOWLY
IMPROVE IN MOST AREAS THIS AFTERNOON BUT WITH THE THREAT OF A
STRAY SHOWER OR THUNDERSTORM REMAINING.
A SECONDARY DISTURBANCE DROPPING OUT OF THE GR LAKES TONIGHT WILL
LIKELY BRING A RETURN OF MVFR/IFR CEILINGS TO THE LAURELS AND
NORTHERN MOUNTAIN TERMINALS...WITH THE POTENTIAL FOR CEILINGS IN
THE 1000-3000` RANGE EVEN CREEPING INTO THE CENTRAL MOUNTAINS AND
UPPER SUSQ VALLEY.
OUTLOOK...
WED...MVFR/IFR WEST AND NORTH TO START THE DAY...BECOMING MOSTLY
VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR/LA CORTE
NEAR TERM...DEVOIR/LA CORTE
SHORT TERM...DEVOIR
LONG TERM...HAGNER
AVIATION...LA CORTE/LAMBERT
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1012 AM CDT TUE AUG 11 2015
.AVIATION/18Z TAFS/...VFR CU FIELD EXPECTED WITH LINGERING CHILLY
MID LEVEL CYCLONIC FLOW. KGRB 500 TEMP -14C. LOW LEVEL THERMAL
TROUGH SUPPORTIVE OF CU DEVELOPMENT AS WELL. ALREADY SEEING THIS
DEVELOPMENT BETWEEN 14-15Z ON VIS IMAGERY. MESO MODELS PAINT QPF
MAINLY IN 22-03Z TIME FRAME. LAKE BREEZE CONVERGENCE AND
32 UNIT VORT DROPPING SSE FROM NORTH OF LAKE SUPERIOR WILL HAVE
TO BE WATCHED. HOWEVER RAP SOUNDINGS SHOW VERY LITTLE IF ANY CAPE
WITH OVERALL PARCHED COLUMN. SO FOR NOW WILL NOT INTRODUCE PRECIP
CHCS AT THIS TIME.
PC
&&
.MARINE...WEAKENING PRESSURE GRADIENT OVER LAKE MICHIGAN WILL ALLOW
WINDS TO TURN TO THE NORTH TO NORTHEAST LATE THIS MORNING AND
CONTINUE THROUGH THE AFTERNOON. WIND SPEEDS WILL INCREASE BUT GUSTS
WILL REMAIN BELOW SMALL CRAFT ADVISORY LEVELS. FURTHER WEAKENING OF
THE PRESSURE GRADIENT WILL ALLOW WIND SPEEDS TO DECREASE TO LESS
THAN 10 KTS TONIGHT.
MBK
&&
.BEACHES...NORTHWEST WINDS WILL TURN TO THE NORTHEAST THIS MORNING
AND INCREASE TO 10 TO 15 MPH...WITH POSSIBLY A GUST OR TWO UP TO 20
MPH. THE WINDS WILL DECREASE LATER THIS AFTERNOON AND EVENING.
THIS BRIEF PERIOD OF STRONGER ONSHORE WINDS WILL RESULT IN A
MODERATE SWIM RISK THIS AFTERNOON AND EVENING WITH WAVES BUILDING
TO 2 TO 4 FEET. BREAKING WAVES AND CURRENTS ARE EXPECTED.
MBK
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT TUE AUG 11 2015/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS HIGH.
DRY AIR CONTINUES TO SPREAD INTO THE REGION AS A BROAD HIGH
PRESSURE BUILDS IN. SOUNDINGS INDICATE SOME DIURNAL CUMULUS CLOUDS
BY THIS AFTERNOON...NO MORE THAN SCATTERED AT INLAND LOCATIONS.
THERE IS A POTENTIAL OF BROKEN CUMULUS IN THE EAST...WITH
CONVERGENCE AS NORTHEAST LAKE BREEZE DEVELOPS. THIS WILL ALSO COOL
OFF EASTERN LOCATIONS AFTER HIGHS IN THE MID 70S...WITH 925 MB
TEMPS SUPPORTING UPPER 70S TO LOWER 80S INLAND.
LIGHT WINDS AND CLEARING SKIES TONIGHT ALLOW GOOD RADIATIONAL
COOLING...WITH LOWS IN THE MID 50S AWAY FROM THE LAKE. EXPECT TO
SEE PATCHY FOG...ESPECIALLY IN THE RIVER VALLEYS AND LOW LYING
RURAL AREAS...BUT NOT EXPECTING TO FALL MUCH BELOW 3 TO 5 MILES
EXCEPT IN THE WI RIVER VALLEY.
SHORT TERM...WEDNESDAY THROUGH THURSDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.
MODELS ARE IN PRETTY GOOD AGREEMENT WITH HIGH PRESSURE TO THE
SOUTHWEST OF THE AREA SLIDING SLOWLY SOUTHEASTWARD WEDNESDAY AND
WEDNESDAY NIGHT. 500 MB FLOW REMAINS NORTHWESTERLY DURING THIS
TIME...WITH A VORTICITY MAXIMUM SLIDING ACROSS NORTHEAST WISCONSIN
INTO CENTRAL LAKE MICHIGAN WEDNESDAY.
THERE IS SOME WARM AIR ADVECTION THAT DEVELOPS LATER WEDNESDAY
INTO WEDNESDAY NIGHT...WHICH HELPS GENERATE SOME LIGHT QPF OVER
AND EAST OF NORTHERN LAKE MICHIGAN. GFS TRIES TO EXTEND THIS
SOUTHWARD INTO THE FAR EASTERN COUNTIES. HOWEVER...AREA FORECAST
SOUNDINGS ARE REMAINING FAIRLY DRY DURING THIS PERIOD.
THUS...KEPT THE DRY FORECAST GOING WEDNESDAY AND WEDNESDAY NIGHT.
HIGHS IN THE LOWER 80S ARE EXPECTED AWAY FROM THE LAKE...WITH
UPPER 70S CLOSER TO SHORE. LAKE BREEZE SHOULD DEVELOP IN THE
AFTERNOON...ESPECIALLY MILWAUKEE AND SOUTHWARD.
MODELS ARE SHOWING THE WARM AIR ADVECTION CONTINUING THURSDAY INTO
THURSDAY NIGHT...WITH THE COLD FRONT APPROACHING THE AREA THURSDAY
NIGHT FROM THE NORTHWEST. GUSTY SOUTHWEST WINDS ARE EXPECTED
THURSDAY WITHIN A TIGHT PRESSURE GRADIENT. THIS SHOULD BRING HIGHS
WELL INTO THE 80S ACROSS THE ENTIRE AREA...WITH HUMID CONDITIONS.
AREA FORECAST SOUNDINGS ARE SHOWING A DECENT CAP DEVELOPING
THURSDAY WITH THE WARM AIR ADVECTION...WHICH MAY DELAY ANY SHOWERS
AND THUNDERSTORMS UNTIL THURSDAY NIGHT AS THE FRONT APPROACHES.
KEPT LOW POPS FOR THURSDAY IN THE NORTH...WITH HIGHER POPS
THURSDAY NIGHT. MEAN LAYER CAPES ARE SOLIDLY IN THE 1000 TO 1500
J/KG RANGE...THOUGH DEEP LAYER SHEAR IS FAIRLY WEAK.
LONG TERM...FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS BRINGS THE COLD FRONT THROUGH THE AREA FRIDAY...BEFORE
SLIDING SOUTHWARD BY LATER FRIDAY NIGHT. SOME TIMING DIFFERENCES
HERE...THOUGH BOTH MODELS SHOW A 500 MB VORTICITY MAXIMUM PASSING
SOUTHEAST THROUGH THE REGION. KEPT POPS GOING FOR FRIDAY INTO
FRIDAY NIGHT FOR NOW...WITH WARM AND HUMID CONDITIONS.
CONTINUED DRY FORECAST FOR SATURDAY INTO SUNDAY...AS HIGH PRESSURE
AXIS KEEPS THE AREA DRY. MODELS THEN DIFFER WITH TIMING AND
PLACEMENT OF NEXT COLD FRONT MOVING INTO THE REGION SUNDAY NIGHT
INTO MONDAY. CONTINUED CONSENSUS POPS AND TEMPERATURES FOR NOW.
AVIATION/12Z TAFS/...
EXPECT VFR CONDITIONS AFTER ANY PATCHY FOG DISSIPATES BY 14Z.
DIURNAL VFR CUMULUS WILL BE MAINLY SCATTERED AT INLAND LOCATIONS.
THERE IS A POTENTIAL OF A PERIOD OR TWO OF BROKEN CUMULUS IN THE
EAST...WITH CONVERGENCE AS NORTHEAST LAKE BREEZE DEVELOPS.
EXPECT SOME PATCHY FOG TONIGHT WITH LIGHT WINDS AND CLEAR
SKIES...BUT NOT CERTAIN IT WILL BE AT TAF SITES. THIS WOULD BE
ESPECIALLY SO AT THE EASTERN TAF SITES...WHERE WARMER TEMPS DUE
TO THE ONSHORE FLOW OFF OF THE WARMER LAKE WILL PREVENT COOLING
DOWN TO DEW POINTS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...WOOD
AREA FORECAST DISCUSSION
NWS PUEBLO CO
312 PM MDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
SCATTERED THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS THIS
AFTERNOON...AS MOISTURE (PRECIPITABLE WATER OVER 1 INCH) AND
INSTABILITY (CAPES ABOVE 1000 J/KG MOST AREAS) REMAIN PLENTIFUL.
GENERALLY FOLLOWED THE HRRR FOR CONVECTIVE TRENDS FOR LATE AFTERNOON
INTO THE EVENING...WITH A WAVE OF STRONGER CONVECTION OVER THE
MOUNTAINS MOVING INTO THE NORTHERN I-25 CORRIDOR OVER PUEBLO AND EL
PASO COUNTIES IN THE 21Z-01Z TIME FRAME...BRINGING A THREAT OF HEAVY
RAIN TO AREAS AROUND COLORADO SPRINGS/WALDO CANYON. FARTHER
SOUTH...CONVECTION ALONG THE SOUTHERN I-25 CORRIDOR WILL EXPAND
EASTWARD INTO THE EVENING...WITH SOME POCKETS OF HEAVY RAIN ALONG
AND SOUTH OF THE ARKANSAS RIVER. MOUNTAINS AND INTERIOR VALLEYS WILL
SEE A CONTINUATION OF SCATTERED CONVECTION...WITH MODELS AND LATEST
SATELLITE LOOP SUGGESTING LEAST ACTIVITY OVER THE SOUTHWEST
MOUNTAINS AS STRONGER CONVECTION OVER AZ STAY FAIRLY FAR TO THE
WEST.
OVERNIGHT...HRRR DEVELOPS ANOTHER BAND OF HEAVIER PRECIP OVER THE
ARKANSAS VALLEY 04Z-06Z FROM FREMONT COUNTY EAST THROUGH PUEBLO AND
LA JUNTA...WITH FAIRLY VIGOROUS CONVECTION WELL INTO THE NIGHT. NOT
SURE HOW REALISTIC THIS IS GIVEN INITIAL CONVECTION THIS AFTERNOON
POTENTIALLY STABILIZING THE AIR MASS SOMEWHAT...BUT WILL MAINTAIN
POPS PAST MIDNIGHT MANY AREAS AS MOST MODELS KEEP AT LEAST SOME
PRECIP GOING PAST 06Z.
ON WEDNESDAY...EXPECT A DOWNTURN IN CONVECTION AS UPPER RIDGE
CONTINUES TO SLOWLY BUILD NORTHWARD ACROSS THE STATE...WHILE POCKET
OF DRIER AIR OVER WESTERN NM ROTATES NORTHWARD INTO THE REGION.
STILL ENOUGH RESIDUAL MOISTURE FOR ISOLATED TSRA MOST LOCATIONS IN
THE AFTERNOON...THOUGH STORM INTENSITY AND THE THREAT OF HEAVY RAIN
SHOULD BE LESS THAN THE PAST COUPLE DAYS. HIGHEST POPS WILL BE OVER
THE MOUNTAINS...ESPECIALLY NORTHERN HALF OF THE AREA WHERE SLIGHTLY
DEEPER MOISTURE WILL REMAIN. MAX TEMPS MOST LOCATIONS WILL BEGIN TO
MOVE UPWARD AS AIR MASS DRIES AND HEIGHTS BUILD...THOUGH READINGS
WILL STILL BE AT OR SLIGHTLY BELOW MID AUGUST AVERAGES BY LATE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
WEDNESDAY NIGHT THROUGH FRIDAY...A LARGE RIDGE OF HIGH PRESSURE IS
EXPECTED TO BE CENTERED OVER THE REGION THROUGH FRIDAY...KEEPING
WINDS ALOFT LIGHT. MOISTURE TRAPPED UNDER THE HIGH WILL FEED DIURNAL
AFTN AND EVE MT SHOWERS AND STORMS...AND STORMS THAT DO DEVELOP WILL
BE SLOW-MOVING AND MOVEMENT WILL BE DIFFICULT TO ANTICIPATE. LOOK
FOR MAX TEMPS TO REMAIN SOMEWHAT STEADY THROUGH THE PERIOD WITH AFTN
HIGHS IN THE 80S FOR THE HIGH VALLEYS...AND 80S TO MID 90S FOR THE E
PLAINS.
SATURDAY THROUGH MONDAY...MODELS INDICATE THAT AN UPPER SHORTWAVE
WILL CROSS MONTANA ON SATURDAY...WHICH WILL HELP TO SOMEWHAT FLATTEN
THE UPPER RIDGE AND EDGE IT TO THE SOUTH. A FRONTAL BOUNDARY WILL
DROP DOWN THE E PLAINS ON SUNDAY...BUT AT THIS TIME THERE DOES NOT
SEEM TO BE MUCH BY WAY OF SIGNIFICANT COOLING OR INCREASED
CONVECTIVE ACTIVITY WITH THIS FEATURE. LOOK FOR A CONTINUATION OF
THE DIURNAL AFTN AND EVE MT STORMS...THOUGH THERE IS A SLIGHT HINT
OF PERHAPS SOME LINGERING SHOWERS DURING THE OVERNIGHT PERIOD. AS
FOR TEMPS...MAX TEMPS WILL REMAIN IN THE 80S TO LOWER 90S FOR THE
PLAINS...AND 80S FOR THE HIGH VALLEYS.
TUESDAY...LONG RANGE MODELS SHOW A LOW DROPPING OUT OF CANADA AND
INTO MT AND THE DAKOTAS FOR TUE...SHUNTING THE UPPER RIDGE TO THE
SW. THIS IS STILL A BIT FAR OUT TIME-WISE TO MAKE SIGNIFICANT
CHANGES...BUT IF THIS SOLUTION PERSIST OVER THE NEXT FEW DAYS THEN
THIS MIGHT BRING COOLER TEMPS AND MORE PCPN FOR THE FORECAST AREA.
MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 312 PM MDT TUE AUG 11 2015
FOR LATE THIS AFTERNOON AND EVENING...FOLLOWED THE HRRR FORECAST FOR
CONVECTION...WITH TSRA MOUNTAINS MOVING ACROSS LOWER ELEVATIONS 21Z-
04Z. BEST WINDOW FOR STORMS AT KCOS AND KPUB STILL LOOKS TO BE 22Z-
01Z...WITH PERHAPS SOME WEAKER CONVECTION PERSISTING 01Z-04Z.
POTENTIAL FOR MVFR/BRIEF IFR BOTH SITES AS RAIN WILL BE HEAVY AT
TIMES. AT KALS...STILL A LOW THREAT OF TSRA INTO THE
EVENING...THOUGH STORM CHANCES LOOK LOWER HERE AS SOME DRY AIR
BEGINS TO WORK NORTHWARD OUT OF NM. TSRA DIMINISH AND SHIFT EAST
TOWARD KS OVERNIGHT...WITH A REPEAT OF MVFR STRATUS POSSIBLE AT KCOS
AND OVER THE EASTERN PLAINS AFTER ABOUT 10Z AS SURFACE WINDS BECOME
LIGHT SE. ON WED...VFR CONDITIONS FROM MID MORNING ONWARD WITH FEWER
AFTERNOON STORMS AS AIR MASS BEGINS TO DRY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1134 AM MDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM MDT TUE AUG 11 2015
CHANCES FOR HEAVY RAIN THE MAIN CONCERN FOR TODAY...WITH PLENTY OF
MOISTURE REMAINING OVR THE FORECAST AREA. FORECAST MODELS ARE NOT IN
GOOD AGREEMENT AS TO WHERE THE POTENTIAL HEAVY RAIN BULLSEYES MAY BE
TODAY. THE NAM SHOWS A DISTURBANCE LIFTING NORTHWARD ACRS THE AREA
THIS MORNING AND SHOWS A BAND OF HEAVIER PCPN WORKING NORTHWARD WITH
THE DISTURBANCE. HOWEVER...THE NAM IS CURRENTLY NOT VERIFYING WELL
AS IT SHOW FAIRLY WIDESPREAD PCPN ACRS THE AREA BETWEEN 06Z AND 12Z
AND SO FAR THIS IS NOT HAPPENING. IN THE AFTERNOON HOURS THE NAM
HAS THE BEST CHANCES FOR PCPN OVR THE ERN PLAINS AND NORTHERN
PORTIONS OF THE CWA. WITH EAST TO SOUTHEAST UPSLOPE OVR EL PASO
COUNTY THRU THE DAY AND GOOD CHANCES FOR PCPN...ESPECIALLY THIS
EVENING...LOCALLY HEAVY RAINFALL AND FLASH FLOODING WL BE A
CONCERN...ESPECIALLY BECAUSE MUCH OF EL PASO COUNTY HAS HAD
SIGNIFICANT PCPN AMOUNTS IN THE LAST DAY AND A HALF RESULTING IN
SATURATED SOILS WHICH WL RESULT IN A LOT OF RUNOFF IF THE RAIN IS
HEAVY. THE NSSL 4KM WRF IS SIMILAR TO THE NAM...SHOWING HAVING PCPN
ACRS PORTIONS OF THE SERN PLAINS EARLY THIS MORNING...BUT THEN SHOWS
DECREASING PCPN CHANCES BY LATE MORNING. IT THEN HAS SCT PCPN FOR
THE AFTERNOON AND EVENING HOURS WITH LOCALIZED AREAS OF HEAVY RAIN.
THE HRRR DOES NOT SHOW THE SAME KIND OF HEAVY RAIN BAND MOVING NORTH
ACRS THE FORECAST AREA THIS MORNING LIKE THE NAM SHOWS. EXCEPT OVR
THE FAR ERN AREAS WHERE IT SHOWS WIDESPREAD PCPN UNTIL LATE MORNING.
CURRENT RADAR IMAGES SHOW PCPN WORKING ITS WAY NORTH INTO THE SERN
CORNER OF CO...WITH WIDESPREAD PCPN ALSO MOVING INTO THE SW MTNS.
FOR NOW WL MAINLY BROADBRUSH MUCH OF THE AREA WITH SCT POPS...EXCEPT
FOR SOME HIGHER POPS OVR PORTIONS OF THE HYR TRRN.
BY LATE TONIGHT...PCPN WL BE ON THE DECREASE ALTHOUGH AT LEAST SCT
PCPN SHOULD CONTINUE ALONG MUCH OF THE CONTDVD. SOME ISOLD
SHOWERS/TSTMS SHOULD ALSO CONTINUE MUCH OF THE NIGHT OVR THE FAR
SERN PLAINS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 357 AM MDT TUE AUG 11 2015
WEDNESDAY-FRIDAY...A BROAD UPPER HIGH CENTERED ACROSS NORTHEASTERN
NEW MEXICO AND NORTHWESTERN TEXAS EARLY WEDNESDAY IS PROGGED TO
BUILD SLOWLY NORTH AND WEST ACROSS THE CENTRAL ROCKIES AND INTO THE
FOUR CORNERS REGION THROUGH THE END OF THE WORK WEEK. THIS WILL
ALLOW FOR A GRADUAL LESSENING OF AFTERNOON AND EVENING STORMS ACROSS
THE AREA...AS THE MONSOONAL MOISTURE PLUME IS SHUNTED NORTH AND WEST
OF THE AREA...ALONG WITH WARMING TEMPERATURES ALOFT UNDER THE
BUILDING RIDGE HELPING TO SUPPRESS CONVECTION. BEST COVERAGE OF
STORMS THROUGH THE PERIOD LOOKS TO BE ACROSS THE CENTRAL MOUNTAINS
THROUGH THE PIKES PEAK REGION WITH A FEW STORMS DRIFTING OFF THE
HIGHER TERRAIN ACROSS THE IMMEDIATE ADJACENT PLAINS. THERE STILL
WILL BE ENOUGH MOISTURE...COMBINED WITH SLOW STORM MOVEMENT...TO
KEEP THE POTENTIAL FOR LOCALLY HEAVY RAINFALL ACROSS THE AREA.
SHOULD ALSO SEE TEMPERATURES WARMING BACK TO ABOVE SEASONAL AVERAGES
THROUGH THE PERIOD...WITH THE WARMING ALOFT AND LESS EXPECTED
COVERAGE OF STORMS.
SATURDAY-MONDAY...UPPER HIGH GETS SHUNTED SOUTH AND WEST ACROSS THE
DESERT SOUTHWEST...AS SEVERAL EMBEDDED SHORT WAVES TRANSLATE THROUGH
THE FASTER ZONAL FLOW ALOFT ACROSS THE NORTHERN TIER OF STATES. ONE
WAVE LOOKS TO SEND A COLD FRONT ACROSS THE EASTERN PLAINS SATURDAY
NIGHT WHICH WILL ALLOW FOR BETTER COVERAGE OF STORMS...ESPECIALLY
OVER AND NEAR THE EASTERN MOUNTAINS...AS LOW LEVEL MOISTURE
INCREASES WITHIN EASTERLY UPSLOPE FLOW. WITH MORE MOISTURE AND
SLIGHTLY COOLER AIR ALOFT...SHOULD SEE TEMPERATURES COOLING BACK TO
AROUND SEASONAL AVERAGES THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1128 AM MDT TUE AUG 11 2015
STILL A SMALL PATCH OF STRATUS HANGING ON AROUND KCOS AS OF
1730Z...EXPECT THIS TO FINALLY DISSIPATE 18Z-19Z AS SATELLITE
LOOPS SHOW CLOUDS THINNING/DECREASING. FOR THIS AFTERNOON AND
EVENING...FOLLOWED THE HRRR FORECAST FOR CONVECTION...WITH TSRA
DEVELOPING OVER THE MOUNTAINS 18Z-21Z...THEN MOVING ACROSS LOWER
ELEVATIONS 21Z-04Z. BEST WINDOW FOR STORMS AT KCOS AND KPUB LOOKS
TO BE 22Z-01Z...WITH PERHAPS SOME WEAKER CONVECTION PERSISTING
01Z-04Z. AT KALS...CONVECTIVE WINDOW A LITTLE WIDER WITH VCTS
MENTION FOR MUCH OF THE AFTERNOON INTO THE EVENING. TSRA DIMINISH
AND SHIFT EAST TOWARD KS OVERNIGHT...WITH A REPEAT OF MVFR STRATUS
AT KCOS POSSIBLE AFTER ABOUT 10Z AS SURFACE WINDS BECOME LIGHT
SE.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
429 PM EDT TUE AUG 11 2015
.SYNOPSIS...
A COLD FRONT THAT WILL APPROACH SOUTHERN NEW ENGLAND TONIGHT. SCATTERED
SHOWERS/THUNDERSTORMS THROUGH EARLY EVENING...WITH CONTINUED RISK
OF LOCALLY HEAVY DOWNPOURS. SOME LINGERING INSTABILITY WEDNESDAY
WILL GENERATE SOME CLOUDS AND A SCATTERED SHOWER OR ISOLATED
THUNDERSTORM. HIGH PRESSURE WILL BRING DRY AND MILD CONDITIONS
DURING THURSDAY INTO FRIDAY. A FRONT WILL APPROACH FRIDAY
NIGHT...SLOWLY CROSSING THE REGION THIS WEEKEND. THE BEST CHANCE
FOR SHOWERS AND THUNDERSTORMS LOOK TO OCCUR SATURDAY INTO EVENING.
DRY AND SEASONABLE CONDITIONS RETURN LATE THIS WEEKEND INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH 7 PM...
CONTINUE TO HAVE HEAVY SHOWERS TRACKING THROUGH SE MA WITH GRADUAL TRANSITION
OF WHOLE AREA TO EAST. THERE IS SOME TRAINING BUT NOT CONTINUOUS ENOUGH
DISTRIBUTION OF CELLS TO CAUSE MORE THAN LOCALIZED STREET FLOODING AT
THIS TIME.
BEEN A CHALLENGING FORECAST FOR WIND GUSTS TODAY. THE INVERSION
HELD ENOUGH TO PREVENT THE STRENTHENING LOW LEVEL JET FROM MIXING
COMPLETELY DOWN TO THE SURFACE. DID SEE A FEW GUSTS OVER 30 KT IN
MASS BAY AS CORE OF LOW LEVEL JET MOVED THROUGH. RISK OF THOSE
STRONGER WIND GUSTS ASSOCIATED WITH THE LOW LEVEL JET HAS PASSED.
RISK OF ISOLATED STRONG TSTMS CT RIVER VALLEY AND WEST THROUGH 7
PM AS THAT REGION GRADUALLY DESTABILIZES WITH FINALLY GETTING
SOME BREAKS IN THE CLOUD COVER. SBCAPES WERE EDGING ABOVE 1000
J/KG BUT PROBABLY TOO LITTLE TOO LATE FOR MORE THAN A RISK OF JUST
AN ISOLATED STRONG TSTM OR TWO. WITH PWATS 1.7+ AND SLOW MOVEMENT
OF CELLS IN EASTERN NEW YORK...WE WILL NEED TO MONITOR CLOSELY 1
TO 3 HOUR RAFL FOR ANY CELL CLUSTERS THAT CONTAIN SOME LONGEVITY
IN OUR AREA. NOTE THAT HIGH RESOLUTION HRRR MODEL SUGGESTS THAT
CONVECTIVE ELEMENTS WILL WEAKEN AS THEY MOVE EAST OF THE CT RIVER
VALLEY.
AFTER 7 PM...ANY CONVECTION SHOULD SUBSIDE. COLD FRONT MOVES
THROUGH BUT DEACCELERATES AND THUS DEWPOINTS ONLY SLOWLY DROP
DURING EARLY MORNING HOURS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WED...THINK MOST OF WED SHOULD BE DRY...ALTHOUGH SOME MIXED
SIGNALS FOR WIDELY SCATTERED CONVECTION ACROSS EASTERN MA.
SURFACE COLD FRONT SEEMS TO SAG BACK A LITTLE ACROSS EASTERN AND
SOUTHEASTERN MA THROUGH WED AFTERNOON AND SO PROVIDES AN
OPPORTUNITY FOR SOME MOISTURE CONVERGENCE. COLD TEMPERATURES ALOFT
REFLECTED IN TOTAL TOTALS NEAR/A LITTLE ABOVE 50 ACROSS EASTERN MA
PROVIDE SOME INSTABILITY. HOWEVER...AIR MASS DRIES SOME AS
REFLECTED IN K INDICES ONLY IN MID TO UPPER 20S. LIGHT WIND FIELD
DURING DAY WILL LIKELY PROMPT SEA BREEZES ALONG THE
COAST...POSSIBLY PROVIDING A FOCUS FOR SOME WIDELY SCATTERED
CONVECTION IN EASTERN MA. ENOUGH SUN EXPECTED TO BRING INTERIOR
TEMPERATURES INTO THE LOWER 80S WED AFTERNOON.
WED NIGHT...SURFACE COLD FRONT MOVES EAST OF AREA AND UPPER TROF
AXIS SLOWLY MOVES THROUGH. DRIER AIR/LOWERING DEWPOINTS EXPECTED.
MAY JUST HAVE A LITTLE PATCHY EARLY MORNING FOG SOME VALLEYS.
TEMPERATURES SHOULD DROP TO MID 50S NW MA TO LOW TO MID 60S SE
COASTAL PLAIN.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* DRY AND SEASONABLE CONDITIONS EXPECTED ON THURSDAY
* A COLD FRONT WILL SLOWLY MOVE ACROSS THE REGION LATE FRIDAY
NIGHT INTO SATURDAY NIGHT
* MAINLY DRY CONDITIONS SHOULD FOLLOW FOR SUNDAY-MONDAY
OVERVIEW...
MEDIUM RANGE MODELS AND ENSEMBLES CONTINUE TO FEATURE AMPLIFIED
UPPER LEVEL PATTERN ACROSS NORTH AMERICA FOR THU/FRI TIMEFRAME.
STARTING OFF THU/FRI WITH RIDGING OVER THE PLAINS STATES THRU THE
UPPER MIDWEST...WITH A WEAKENING UPPER TROUGH OVER THE EASTERN
STATES. THEN THE UPPER RIDGE SLIDES EAST SOMEWHAT DURING THIS
WEEKEND AS THE WEAK TROUGH LIFTS OUT. UPPER RIDGING MAY HOLD OVER
OUR AREA INTO THE BEGINNING OF NEXT WEEK.
USING ENSEMBLE GUIDANCE FOR THIS FORECAST PACKAGE. TEMPERATURES
EXPECTED TO RANGE FROM SEASONABLE TO A FEW DEGREES ABOVE NORMAL
THROUGH THE PERIOD.
DETAILS...
THURSDAY-FRIDAY...SURFACE HIGH PRESSURE BRINGS DRY CONDITIONS TO THE
AREA DURING THIS PERIOD. WILL SEE GENERALLY MOSTLY SUNNY SKIES AND
SEASONABLY MILD/WARM TEMPS.
FRIDAY NIGHT THROUGH SUNDAY...WEAK COLD FRONT/SURFACE TROUGH SLOWLY
APPROACHES IN THE NW FLOW ALOFT. CONTINUE TO THINK THAT BEST CHANCE
FOR SHOWERS/SCT THUNDERSTORMS WILL BE SAT INTO POSSIBLY SAT NIGHT.
MAY SEE A COUPLE OF DOWNPOURS AND LOCALLY GUSTY WINDS IN A FEW OF
THE T-STORMS SAT AFTERNOON/EVENING. 12Z OPERATIONAL RUNS AND MOST
GFS ENSEMBLE MEMBERS INDICATE THE FRONT SHOULD EITHER PUSH SOUTH OF
OUR AREA ON SUNDAY...OR WASH OUT. SO EXPECTING MAINLY DRY CONDITIONS
ACROSS OUR AREA ON SUNDAY. MODERATE CONFIDENCE WITH THIS PORTION OF
THE FORECAST.
MONDAY...SHOULD SEE HIGH PRESSURE BRINGING DRY CONDITIONS AND
TEMPS A FEW DEGREES ABOVE NORMAL.
TUESDAY...DRY CONDITIONS ANTICIPATED TO START...BUT A COLD FRONT MAY
APPROACH FROM THE WEST DURING THE DAY WHICH COULD BRING A CHANCE FOR
SHOWERS/T-STORMS. TEMPS A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT...MODERATE CONFIDENCE. MVFR CIGS/VSBYS IN SHOWERS SE MA
LATE THIS AFTERNOON AND EARLY EVENING. RESIDUAL MOISTURE AND
RELATIVELY HIGH DEWPOINTS WILL LIKELY PROMOTE WIDESPREAD MVFR
CIGS/VSBYS IN FOG OVERNIGHT WITH AREAS OF IFR CIGS/VSBYS.
ELSEWHERE...PATCHY MVFR CIGS/VSBYS IN SCATTERED SHOWERS/TSTMS
THROUGH EARLY EVENING AND IN AREAS OF FOG OVERNIGHT...AIDED BY
RESIDUAL MOISTURE FROM TODAY/S RAIN.
WEDNESDAY...MODERATE TO HIGH CONFIDENCE. CIGS/VSBYS IMPROVE TO
VFR WITH PARTIAL CLEARING. SOME AFTERNOON CUMULUS CLOUDS WITH
SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS FAR NORTHERN AND
ACROSS EASTERN MA.
KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. ANTICIPATE GRADUAL
IMPROVEMENT IN CONDITIONS THROUGH EARLY EVENING BUT RISK OF MVFR
CIGS AND VSBYS REFORMING OVERNIGHT.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. GRADUAL IMPROVEMENT
IN CIGS FOR A TIME VERY LATE AFTERNOON AND EARLY EVENING BUT MVFR
CIGS LIKELY REFORMING OVERNIGHT. VSBYS MAY DROP OVERNIGHT FOR A
TIME 2 TO 4 MILES IN FOG. RISK OF A TSTM 21Z TO 00Z.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY AND FRIDAY...HIGH CONFIDENCE. MAINLY VFR. MAY SEE LATE
NIGHT/EARLY MORNING PATCHY MVFR-IFR VSBYS EACH DAY ACROSS NORMALLY
PRONE INLAND VALLEYS.
SATURDAY...MODERATE CONFIDENCE. MAINLY VFR. LOW CHANCE FOR LOCAL
MVFR CIGS/VSBYS IN ISOLATED TO SCATTERED SHOWERS OR T-STORMS.
SUNDAY...MODERATE CONFIDENCE. MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TONIGHT AND WEDNESDAY...MODERATE TO HIGH CONFIDENCE. WINDS
DIMINISHING TONIGHT BELOW SMALL CRAFT CRITERIA BUT WILL TAKE
LONGER FOR SEAS IN OUTER WATERS TO SUBSIDE BELOW 5 FEET.
HENCE...SMALL CRAFT ADVISORY CONTINUES FOR SE AND S OUTER COASTAL
WATERS UNTIL WED EARLY/MID AFTERNOON.
OUTLOOK /THURSDAY THROUGH SUNDAY/...
THURSDAY...HIGH CONFIDENCE. EXPECT HIGH PRESSURE OVER THE
WATERS...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.
FRIDAY...MODERATE CONFIDENCE. SW WINDS INCREASE FRI AFTERNOON...
GUSTING UP TO AROUND 20 KT. THERE IS A CHANCE THAT SEAS BUILD TO UP
TO 5 FT ON THE OUTER COASTAL WATERS. ELSEWHERE...WINDS AND SEAS
SHOULD REMAIN BELOW SMALL CRAFT LEVELS.
SATURDAY...MODERATE CONFIDENCE. WINDS AND SEAS SHOULD REMAIN
BELOW SMALL CRAFT CONDITIONS. SCT SHOWERS/THUNDERSTORMS MAY
BRIEFLY REDUCE VSBYS SAT AFTERNOON/NIGHT. LOW CHANCE FOR BRIEF
GUSTY WINDS.
SUNDAY...MODERATE CONFIDENCE. WINDS AND SEAS BELOW SCA THRESHOLDS.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT WEDNESDAY FOR ANZ231>235-
237-250-251.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR ANZ230-
236.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT WEDNESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...NMB/THOMPSON
NEAR TERM...THOMPSON
SHORT TERM...THOMPSON
LONG TERM...NMB
AVIATION...NMB/THOMPSON
MARINE...NMB/THOMPSON
AREA FORECAST DISCUSSION
NWS ALBANY NY
151 PM EDT TUE AUG 11 2015
.SYNOPSIS...
AHEAD OF AN APPROACHING COLD FRONT...SCATTERED SHOWERS
AND POSSIBLY A THUNDERSTORM WILL OCCUR ACROSS THE REGION THROUGH THE
EARLY EVENING HOURS. SLIGHTLY COOLER AND LESS HUMID CONDITIONS WILL
BUILD IN FOR WEDNESDAY...ALTHOUGH WITH A CONTINUED CHANCE FOR
SHOWERS AND THUNDERSTORMS AS AN UPPER LEVEL TROUGH REMAINS IN PLACE.
DRY WEATHER WILL RETURN TO THE REGION FOR THURSDAY WITH TEMPERATURES
JUST SLIGHTLY BELOW NORMAL LEVELS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 151 PM...STEADY RAINFALL HAS ENDED AND SHIFTED WELL INTO
EASTERN AND NORTHERN NEW ENGLAND. COLD FRONT REMAINS UPSTREAM OF
THE REGION...WITH THE BOUNDARY NOW LOCATED OVER CENTRAL NY. RADAR
IMAGERY SHOWS SOME SCATTERED SHOWERS HAVE DEVELOPED AHEAD OF THE
BOUNDARY. VISIBLE SATELLTE IMAGERY SHOWS SOME BREAKS IN THE CLOUD
COVER...BUT OVERALL...MOST AREAS ARE REMAINING MOSTLY CLOUDY.
BASED ON CURRENT RADAR ACTIVITY AND 3KM HRRR GUIDANCE...WILL GO
WITH CHC TO LIKELY POPS FOR THIS AFTN INTO THE EARLY EVENING
HOURS. WILL KEEP A SLIGHT CHC FOR THUNDER IN THE FORECAST AS
WELL...AS SOME THUNDER HAS OCCURRED OVER THE SOUTHEASTERN
CATSKILLS ALREADY...AND SOME SFC BASED CAPE IS POSSIBLE WITH THE
OCCASIONAL BREAKS IN THE CLOUD COVER. ANY T-STORM WILL REMAIN
BELOW SEVERE LEVELS DUE TO LIMITED INSTABILITY.
EXPECT HIGHS TODAY TO GENERALLY RANGE FROM THE UPPER 60S TO UPPER
70S. WITH TEMPS ALREADY WARMING INTO THE UPPER 70S IN THE CAPITAL
REGION...WILL HAVE A SHOT AT CONTINUING ONGOING STREAK OF REACHING
80+ AT ALBANY TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
TONIGHT EXPECT SHOWER AND THUNDERSTORM ACTIVITY TO DIMINISH
DURING THE EVENING AS THE LOW PRESSURE SYSTEMS AND ASSOCIATED
FRONTAL BOUNDARIES SLIDE OFF THE NEW ENGLAND COAST. LOWS TONIGHT
ARE EXPECTED TO RANGE FROM THE MID 50S TO MID 60S.
ON WEDNESDAY WILL KEEP A SLIGHT CHANCE TO CHANCE OF SHOWERS ALONG
WITH A SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS AS AN UPPER
TROUGH AXIS WITH A FAIRLY STRONG ASSOCIATED VORT MAX SWING THROUGH
THE FA DURING THE AFTERNOON HOURS. ML MUCAPES APPROACH 1000 J/KG
ACRS PARTS OF THE AREA ON WEDNESDAY AFTERNOON. HIGHS ON WEDNESDAY
WILL BE IN THE UPPER 60S TO LOWER 80S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT LOOKS DRY AT THIS POINT IN
TIME AS A RIDGE OF HIGH PRESSURE BUILDS EAST FROM THE OHIO VALLEY
WEDNESDAY NIGHT AND SETTLES ACROSS THE MIDDLE ATLANTIC REGION
THURSDAY NIGHT. EXPECT LOWS WEDNESDAY NIGHT TO BE IN THE UPPER
40S TO UPPER 50S. HIGHS ON THURSDAY ARE EXPECTED TO BE IN THE
UPPER 60S TO LOWER 80S WITH LOWS THURSDAY NIGHT IN THE 50S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
THE EXTENDED FEATURES THE MEAN UPPER LEVEL TROUGH STILL OVER SE
CANADA AND THE NORTHEAST AS WE HEAD INTO THE FIRST HALF OF THE
WEEKEND...BUT THE MEDIUM RANGE GUIDANCE CONTINUES TO SHOW A TREND
TOWARDS INCREASING LOW AND MID LEVEL HEIGHTS WITH RIDGING BUILDING
IN OVER THE EAST COAST...AND A WARMING TREND TO ABOVE NORMAL TEMPS
INTO EARLY NEXT WEEK.
FRI-FRI NIGHT...A SHORT-WAVE TROUGH IN THE W/NW FLOW ALOFT
APPROACHES UPSTATE NY AND WRN NEW ENGLAND IN THE AFTERNOON. THE GFS
IS MORE AGGRESSIVE WITH THE SHORT-WAVE THAN THE ECMWF/CAN GGEM IN
TERMS OF THE TIMING AND THE AREAL EXTENT OF SHOWERS/ISOLD
THUNDERSTORMS. WE PLACED SLIGHT TO LOW CHC POPS IN FROM THE NRN
CATSKILLS/CAPITAL REGION/BERKSHIRES NORTH AND WEST FOR THE AFTERNOON
AND INTO THE EARLY EVENING. THE COLD FRONT TO THE LOW PRESSURE
SYSTEM MOVING ACROSS W-CNTRL QUEBEC LOOKS TO ARRIVE FOR SATURDAY.
H850 TEMPS INCREASE TO ABOUT +15C TO +17C WITH A WEAK THERMAL
TROUGH/WARM FRONT PASSAGE...AS HIGH TEMPS WILL BE IN THE 80-85F
RANGE IN THE MAJOR RIVER VALLEYS...AND 70S TO NEAR 80F OVER THE
HILLS AND MTNS. LOWS WILL GENERALLY BE IN THE M50S TO L60S.
SAT-SAT NIGHT...PRETTY GOOD AGREEMENT WITH THE WPC
GRAPHICS/GEFS/ECMWF/GFS/CANADIAN GUIDANCE THAT A COLD FRONT WILL
SLOWLY PROGRESS FROM THE ST LAWRENCE RIVER VALLEY S/SE ACROSS THE
FCST AREA. THE AMOUNT OF SFC DESTABILIZATION WILL DEPEND ON THE
COVERAGE AND INTENSITY OF THUNDERSTORMS. THE GFS HAS THE GREATEST
INSTABILITY FROM THE CAPITAL DISTRICT SOUTHEAST INTO WRN NEW
ENGLAND...BUT GENERALLY LESS THAN 800 J/KG. CHC POPS WERE INCLUDED
UNTIL 00Z/SUN...AND THEN ONLY SLIGHT CHC VALUES WERE USED FOR THE
EXTREME SE PORTION OF THE FCST AREA /SE OF THE CAPITAL DISTRICT/ FOR
SAT NIGHT PRIOR TO MIDNIGHT. HIGHS LOOK SIMILAR TO FRI WITH 80S IN
THE LOWER ELEVATIONS AND NW CT...AND MID AND U70S OVER THE MTNS.
LOWS WILL RANGE FROM THE M50S OVER THE SRN DACKS TO LOWER 60S OVER
THE CAPITAL DISTRICT/MID HUDSON VALLEY/TACONICS/NW CT.
SUNDAY INTO MONDAY...SFC HIGH PRESSURE RIDGES IN FROM THE MID
ATLANTIC STATES OVER THE NORTHEAST...AS THE FRONT DRIFTS OFF THE
COAST. H850 TEMPS RISE BACK TO +15 TO +17C. MID LEVEL HEIGHTS
BEGIN TO RISE OVER THE FCST AREA. SFC DEWPTS WILL RANGE FROM THE
M50S TO L60S /SOME SPOTTY M60S OVER THE MID HUDSON VALLEY/. EXPECT
HIGHS TO BE IN THE MID 80S IN MANY OF THE VALLEY AREAS...AND U70S TO
L80S OVER THE HIGHER TERRAIN. SOME RADIATIONAL COOLING WILL ALLOW
TEMPS TO FALL BACK INTO THE 50S TO AROUND 60F IN A FEW SPOTS. A
HOTTER MID AUGUST AIR MASS CONTINUES TO RIDGE IN FROM THE MID
ATLANTIC COASTAL REGION WITH HIGHS APPROACHING THE MID AND U80S IN
THE VALLEY AREAS...AND UPPER 70S TO L80S OVER THE MTNS. IT WILL
ALSO BECOME MORE HUMID TO OPEN THE WEEK...WITH PERHAPS A FEW ISOLD
SHOWERS OVER THE SRN DACKS/SRN GREENS LATE IN THE PM.
OVERALL...TEMPS WILL GENERALLY BE SLIGHTLY ABOVE NORMAL WITH PCPN
BELOW NORMAL IN THE LONG TERM.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE WILL CONTINUE TO MOVE DOWN THE SAINT LAWRENCE VALLEY
THIS AFTERNOON AND EVENING. THE ASSOCIATED OCCLUDED FRONT WILL
MOVE ACROSS THE TAF SITES BETWEEN 21Z AND 22Z THIS AFTERNOON.
AHEAD OF AND ALONG THE FRONT THERE WILL BE SCATTERED SHOWERS AND
POSSIBLY A TSTM. HAVE INCLUDED VCSH WITH VFR VSBYS AND MVFR/VFR
CIGS INTO THIS EVENING...AND TEMPO GROUPS FOR MVFR VSBYS AND
MVFR/IFR CIGS UNTIL THE FRONT PASSES.
AFTER THE FRONT PASSES THERE SHOULD BE A BRIEF PERIOD OF VFR
CONDITIONS AT THE KGFL/KALB/KPOU/KPSF TAF SITES. HOWEVER...AFTER
ALL THE RAIN THERE WILL BE PLENTY OF RESIDUAL LOW LEVEL MOISTURE
AROUND AND WINDS WILL GENERALLY BE LIGHT...SO EXPECT MVFR/IFR
CONDITIONS DUE TO FOG TO BE A PROBLEM LATER TONIGHT AND EARLY
WEDNESDAY MORNING. AFTER AROUND 12Z WEDNESDAY...VFR CONDITIONS
SHOULD RETURN.
SURFACE WINDS WILL BE SOUTHERLY AT 5 TO 10 KTS UNTIL THE FRONT
MOVES THROUGH...THEN SHIFT TO WESTERLY AROUND 21Z AT KALB/KGFL...
AND 22Z AT KPSF/KPOU BEHIND THE FRONT. TONIGHT WINDS WILL BECOME
LIGHT AND VARIABLE...THEN NORTHWEST AT 5 TO 10 KTS ON WEDNESDAY.
OUTLOOK...
WEDNESDAY AFTN: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY NIGHT: NO OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
A DEVELOPING LOW PRESSURE SYSTEM LOCATED OVER THE CENTRAL GREAT
LAKES WILL TRACK NORTHEASTWARD INTO THE SAINT LAWRENCE VALLEY
TODAY. THIS LOW WILL DRAG A COLD FRONT THROUGH OUR REGION LATE
TODAY. THE SYSTEM WILL BRING A WIDESPREAD SOAKING RAINFALL TO THE
REGION WITH SOME EMBEDDED THUNDERSTORMS AND LOCALLY HEAVY RAINFALL
TODAY. SLIGHTLY COOLER AND LESS HUMID CONDITIONS WILL BUILD IN FOR
WEDNESDAY...ALTHOUGH WITH A CONTINUED CHANCE FOR SHOWERS AND
THUNDERSTORMS AS AN UPPER LEVEL TROUGH REMAINS IN PLACE.
RELATIVE HUMIDITY VALUES WILL ONLY DROP TO 65 TO 85 PERCENT
TODAY...RECOVER TO 90 TO 100 PERCENT TONIGHT AND DROP TO 45 TO 65
PERCENT ON WEDNESDAY.
WINDS TODAY WILL BE SOUTHERLY AROUND 5 TO 15 MPH WITH OCCASIONAL
GUSTS OF 20 TO 30 MPH...ESPECIALLY ACROSS THE HIGHER TERRAIN.
WINDS WILL SHIFT TO THE WEST AT 5 TO 10 MPH TONIGHT AND WINDS WILL
BE NORTHWEST AT 5 TO 15 MPH WITH GUSTS 25 TO 35 MPH ACROSS THE
HIGHER TERRAIN.
&&
.HYDROLOGY...
MODERATE TO LOCALLY HEAVY RAINFALL AMOUNTS ARE EXPECTED THROUGH
EARLY THIS EVENING ALTHOUGH SINCE IT HAS BEEN DRY OF LATE ACROSS
MUCH OF THE AREA...ONLY WITHIN BANK RIVER RISES ARE EXPECTED.
THERE COULD BE SOME LOCALIZED MINOR FLOODING IN URBAN...LOW
LYING...AND POOR DRAINAGE AREAS. AVERAGE BASIN RAINFALL OF 1 TO 2
INCHES IS FORECAST...WITH LOCALIZED AMOUNTS UP TO 3 INCHES
POSSIBLE ACROSS THE SOUTHEAST FACING SLOPES OF THE HIGHER TERRAIN.
THE THREAT FOR ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE THROUGH WEDNESDAY AS AN UPPER LEVEL TROUGH REMAINS IN
PLACE ACROSS THE REGION.
MORE RAINFALL IS EXPECTED AS WE ENTER THE WEEKEND WITH SCATTERED
SHOWERS AND THUNDERSTORMS ESPECIALLY ON SATURDAY AFTERNOON AND
SATURDAY EVENING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS/GJM/11/JPV
NEAR TERM...FRUGIS/GJM/11
SHORT TERM...11
LONG TERM...WASULA
AVIATION...GJM
FIRE WEATHER...11
HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
356 PM EDT TUE AUG 11 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA WEDNESDAY...THEN PUSH
SOUTH INTO NORTHERN FLORIDA THURSDAY BEFORE DISSIPATING OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
THROUGH THIS EVENING...DNVA IN THE WAKE OF SHORTWAVE ENERGY MOVING
INTO EASTERN NORTH CAROLINA HAS HELPED TO LIMIT DEEP CONVECTION
FOR MUCH OF THE DAY. HOWEVER...A RECENT INCREASE IN INSOLATION
DUE TO A THINNING OF THE MID/HIGH-LEVEL CLOUD CANOPY IS AIDING
DESTABILIZATION ACROSS MUCH OF THE REGION WITH SBCAPES APRCHG
2000-3000 J/KG AND LIFTED INDICES -5 TO -7C OVER THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS OF 11/19Z.
A STEADY INCREASE IN CONVECTION IS EXPECTED OVER THE NEXT FEW
HOURS...MAINLY CONCENTRATING ACROSS SOUTHEAST SOUTH CAROLINA AND
FAR SOUTHERN GEORGIA. THERE REMAINS SOME UNCERTAINTY HOW FAR
NORTH CONVECTION WILL PROPAGATE AND/OR DEVELOP WITH MUCH OF
INTERIOR SOUTHEAST SOUTH CAROLINA...INCLUDING THE CHARLESTON METRO
AREA...EMBEDDED WITHIN AN INSTABILITY MINIMUM. HIGH RESOLUTION
MODELS SUCH AS THE RAP AND H3R ARE CERTAINLY LESS BULLISH ACROSS
THE CHARLESTON TRI-COUNTY AREA COMPARED TO PREVIOUS RUNS...SO
FORECASTER CONFIDENCE IS CERTAINLY LOWER THAN AVERAGE FOR THIS
LATE IN THE DAY. WILL GO WITH A 50-70 PERCENT POP REGIME THROUGH
EARLY EVENING WITH THE HIGHEST GRIDDED POPS CLUSTERED ROUGHLY
ALONG/SOUTH OF A METTER-BEAUFORT LINE...INCLUDING THE SAVANNAH
METRO AREA. A RISK FOR HEAVY RAIN AND ISOLATED SEVERE TSTMS
REMAINS IN PLACE WITH DAMAGING WINDS...CLOUD TO GROUND LIGHTNING
AND MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS BEING THE
PRIMARY HAZARDS.
TONIGHT...A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST AND
BE BE POSITIONED ACROSS THE FAR SOUTHERN MIDLANDS AND CSRA JUST
BEFORE SUNRISE WEDNESDAY. INDICATIONS ARE THAT THE RIBBON OF
HIGHEST MOISTURE WILL SHIFT OFF THE COAST LATER THIS EVENING AND
WITH IT THE BETTER CHANCES FOR SHOWERS/TSTMS. POPS WILL BE TRICKY
AS MUCH WILL DEPEND ON HOW QUICKLY THE PLUME OF MOISTURE PUSHES
OFFSHORE AND HOW THE MESOSCALE PATTERN CHANGES/MODULATES IN
RESPONSE TO STRONGER CONVECTION LATE THIS AFTERNOON/EVENING. WILL
CARRY 30-50 PERCENT POPS WITH LIKELY POPS OVER THE COASTAL WATERS.
LOWS TONIGHT WILL RANGE
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
WEDNESDAY...THE COLD FRONT WILL MEANDER ALONG THE COAST THOUGH THE
AFTERNOON SEA BREEZE MAY PUSH IT BACK INLAND. MODEL PWATS SHOW ONLY
A SLIGHT AMOUNT OF DRIER AIR TRYING TO PUSH IN FROM THE NORTHWEST
LATE IN THE DAY. THUS THE RAIN CHANCES INLAND WILL BE LIMITED AT
BEST. CLOSER TO THE COAST WHERE THE FRONT...SEA BREEZE AND DEEPER
MOISTURE EXIST...WE EXPECT SCATTERED AFTERNOON/EVENING SHOWERS AND
TSTMS. THE BEST COVERAGE LOOKS TO BE ACROSS SOUTHEAST GEORGIA DUE TO
DEEPER MOISTURE. HIGHS WILL RANGE FROM UPPER 80S ALONG THE COAST TO
LOWER 90S FAR INLAND.
THURSDAY...SOME DRIER AIR SPREADS INTO THE AREA AS HIGH PRESSURE
BUILDS FROM THE NORTH. PWATS EXPECTED TO DROP BELOW 1.5" DURING THE
DAY WITH SFC DEWPOINTS IN THE UPPER 60S EXCEPT ALONG THE COAST.
HOWEVER WITH TEMPS IN THE LOWER 90S AND SOME SHORTWAVE ENERGY
APPROACHING DURING THE AFTERNOON...ISOLATED SHOWERS AND TSTMS
EXPECTED.
FRIDAY...NORTHEAST LOW-LEVEL FLOW WILL GRADUALLY INCREASE MOISTURE
OFF THE ATLANTIC THOUGH INLAND AREAS WILL STILL BE FAIRLY DRY
THROUGHOUT THE COLUMN. A DEEPENING UPPER TROUGH OVER THE SOUTHEAST
COAST WILL SPREAD VORTICITY ENERGY INTO THE AREA FROM THE SOUTH.
THIS COMBINED WITH CONVERGENCE ALONG THE AFTERNOON SEA BREEZE SHOULD
PRODUCE SCATTERED CONVECTION...HIGHEST COVERAGE ACROSS FAR SOUTHEAST
PORTIONS. HIGH TEMPS WILL BE IN THE UPPER 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
A STALLED FRONT TO THE SOUTH AND EAST ALONG WITH SOME WEAK AREAS OF
LOW PRESSURE WILL PERSIST THROUGH THE WEEKEND BEFORE EVENTUALLY
DISSIPATING EARLY NEXT WEEK AS HIGH PRESSURE TRIES TO BUILD FROM THE
SOUTHEAST. THIS PATTERN MEANS THERE WILL BE SOME SHOWER AND
THUNDERSTORM CHANCES THROUGH THE PERIOD...ESPECIALLY FOR SOUTHEAST
GEORGIA AND COASTAL SC WHICH WILL BE NEARER THE DEEPER MOISTURE.
TEMPS SHOULD BE ABOUT NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
INITIAL CONCERN IS PINNING DOWN THE TIMING AND POTENTIAL IMPACTS
FROM TSTMS. RADAR SHOWS CONVECTION EXPANDING OVER EAST-CENTRAL
GEORGIA...WHICH HIGH RESOLUTION MODELS CAPTURED FAIRLY WELL. THIS
ACTIVITY IS EXPECTED TO GRADUALLY EXPAND EAST AND POSSIBLY UP THE
SEA BREEZE. THE BETTER CHANCES FOR IMPACTS WILL BE AT
KSAV...ROUGHLY 20-23Z WHERE TEMPO LOW-END MVFR VSBYS WILL BE SHOWN
IN TSRA. AT KCHS...ITS A BIT MORE UNCERTAIN. MAINTAINED TEMPO 4SM
-TSRA 20-23Z FOR NOW...BUT ADJUSTMENTS MAY BE NEEDED. SHOWER/TSTM
ACTIVITY BY LINGER INTO THE EVENING HOURS BEFORE SHIFTING
OFFSHORE...BUT GUIDANCE SUGGESTS MOST OF THIS WILL MISS THE
TERMINALS. VFR EXPECTED OUTSIDE OF TSTMS. THERE IS A LOW RISK FOR
LOW CLOUDS/STRATUS AT THE TERMINALS JUST BEFORE SUNRISE WEDNESDAY.
EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS POSSIBLE EACH
DAY IN AFTERNOON/EVENING SHOWERS AND TSTMS.
&&
.MARINE...
TONIGHT...LOW-LEVEL JETTING WILL OCCUR OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT. 15-20 KT LOOKS REASONABLE FOR MOST LEGS.
A FEW STRONG TSTMS COULD ALSO OCCUR OVERNIGHT WITH GUSTS TO 35
KT...LOCALLY HEAVY RAINFALL REDUCING VSBYS TO LESS THAN 1 NM AND
CLOUD TO WATER LIGHTNING.
WEDNESDAY THROUGH SUNDAY NIGHT...A WEAK COLD FRONT WILL DROP
INTO THE WATERS LATE WEDNESDAY THEN STALL JUST OFF THE COAST
WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTHWEST. A WEAK
PRESSURE PATTERN WILL EXIST THROUGH WEDNESDAY NIGHT WITH THE MAIN
DRIVE BEING A MODEST AFTERNOON SEA BREEZE ALONG THE COAST
WEDNESDAY. BY THURSDAY AS HIGH PRESSURE STRENGTHENS FROM THE NORTH
AND A COASTAL TROUGH DEVELOPS...A NORTHEAST FLOW SETS UP OVER THE
WATERS WITH INCREASING WINDS AND SEAS. HOWEVER...CONDITIONS
CURRENTLY EXPECTED TO REMAIN BELOW ADVISORY THRESHOLDS THROUGH THE
WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/JRL
...PRELIMINARY AREA FORECAST DISCUSSION...
.SYNOPSIS...
HIGH PRESSURE WILL WEAKEN TODAY. A WEAK COLD FRONT WILL MOVE INTO
THE AREA WEDNESDAY...THEN PUSH SOUTH INTO NORTHERN FLORIDA
THURSDAY BEFORE EVENTUALLY DISSIPATING OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
MESOSCALE UPDATE...DNVA IN THE WAKE OF SHORTWAVE ENERGY MOVING
INTO EASTERN NORTH CAROLINA HAS HELPED TO LIMIT DEEP CONVECTION
FOR MUCH OF THE DAY. HOWEVER...A RECENT INCREASE IN INSOLATION
DUE TO A THINNING OF THE MID/HIGH-LEVEL CLOUD CANOPY IS AIDING
DESTABILIZATION ACROSS MUCH OF THE REGION WITH SBCAPE APPROACHING
2500-3000 J/KG OVER THE SOUTHERN TWO-THIRDS OF THE FORECAST AREA
AS OF 11/17Z.
A STEADY INCREASE IN CONVECTION IS EXPECTED OVER THE NEXT FEW
HOURS...MAINLY CONCENTRATING ACROSS SOUTHEAST GEORGIA AND FAR
SOUTHERN SOUTH CAROLINA. THERE REMAINS SOME UNCERTAINTY HOW FAR
NORTH CONVECTION WILL PROPAGATE AND/OR DEVELOP INTO/OVER MUCH OF
INTERIOR SOUTHEAST SOUTH CAROLINA...INCLUDING THE CHARLESTON METRO
AREA...EMBEDDED WITHIN AN INSTABILITY MINIMUM. HIGH RESOLUTION
MODELS SUCH AS THE RAP AND H3R ARE CERTAINLY LESS BULLISH ACROSS THE
CHARLESTON TRI-COUNTY AREA COMPARED TO PREVIOUS RUNS...SO FORECASTER
CONFIDENCE IS CERTAINLY LOWER THAN AVERAGE FOR THIS TIME OF DAY.
A RISK FOR HEAVY RAIN AND ISOLATED SEVERE TSTMS REMAINS IN PLACE
WITH DAMAGING WINDS...CLOUD TO GROUND LIGHTNING AND MINOR
FLOODING OF LOW LYING AND POOR DRAINAGE AREAS BEING THE PRIMARY
HAZARDS. TRENDS CONTINUE TO BE MONITORED.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
TO BE ISSUED.
&&
.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
TO BE ISSUED.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
INITIAL CONCERN IS PINNING DOWN THE TIMING AND POTENTIAL IMPACTS
FROM TSTMS. RADAR SHOWS CONVECTION EXPANDING OVER EAST-CENTRAL
GEORGIA...WHICH HIGH RESOLUTION MODELS CAPTURED FAIRLY WELL. THIS
ACTIVITY IS EXPECTED TO GRADUALLY EXPAND EAST AND POSSIBLY UP THE
SEA BREEZE. THE BETTER CHANCES FOR IMPACTS WILL BE AT
KSAV...ROUGHLY 20-23Z WHERE TEMPO LOW-END MVFR VSBYS WILL BE SHOWN
IN TSRA. AT KCHS...ITS A BIT MORE UNCERTAIN. MAINTAINED TEMPO 4SM
-TSRA 20-23Z FOR NOW...BUT ADJUSTMENTS MAY BE NEEDED. SHOWER/TSTM
ACTIVITY BY LINGER INTO THE EVENING HOURS BEFORE SHIFTING
OFFSHORE...BUT GUIDANCE SUGGESTS MOST OF THIS WILL MISS THE
TERMINALS. VFR EXPECTED OUTSIDE OF TSTMS. THERE IS A LOW RISK FOR
LOW CLOUDS/STRATUS AT THE TERMINALS JUST BEFORE SUNRISE WEDNESDAY.
EXTENDED AVIATION OUTLOOK...WEDNESDAY THROUGH SUNDAY...MODERATE
CONFIDENCE IN IMPACTS WED DUE TO SHOWERS/TSTMS. RISK OF IMPACTS
FROM SHOWERS/TSTMS/LOW CIGS LOWER THU- SUN BEHIND A COLD
FRONT...ESPECIALLY AT KCHS.
&&
.MARINE...
TO BE ISSUED.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
402 PM CDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH Wednesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The near term will bring chances for heavy rain producing
thunderstorms. The first opportunity will be later tonight as the 4
km NAM, HRRR and NMM models all redevelop convection later in the
day over eastern colorado that moves in to about the western two or
perhaps 3 tiers of KS counties. the key here to support convection
is the very high precipitable water values, and hence conditional
instability present. still no severe weather threat, with mainly
efficient warm rain processes and frequent lightning. easterly
surface wind, and an increasing surface pressure gradient is
expected wednesday with a transient 500 mb shortwave, in the western
counties, in proximity to the high precipitable water axis on the
west edge of the surface high. models again generate precipitation
into wednesday in this zone. extensive cloud cover may again muddle
the high temperature forecast, as occurred today and temperatures
should be at or below normal.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The upper ridge over the central and southern rockies will continue
to amplify, resulting in vorticity disturbances shifted farther
north across the northern plains. however, the GFS and ECMWF show a
vigourous wave during the weekend moving through the northern
states, effectively flattening the upper ridge and returning zonal
flow aloft to the central high plains. this setup will result in low
pressure across western kansas just ahead of an approaching
baroclinic zone/frontal boundary by early to mid week, and a return
to convective chances. the more zonal pattern may stay in place for
at least several days.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Wednesday AFTERNOON)
ISSUED AT 135 PM CDT TUE AUG 11 2015
THE FOCUS FOR TODAY WILL BE INCREASING CEILINGS AT GCK AND
POTENTIAL REDEVELOPMENT OF NON SEVERE CONVECTION LATE IN THE TAF
PERIOD. THE CURRENT TRENDS SHOW INCREASING Ceilings AT GCK,
HOWEVER THE CLOUD FIELD WILL REMAIN OVER THE AREA FOR MUCH OF THE
AFTERNOON WITH A MOIST USPSLOPE ENVIRONMENT . THE REGIONAL RADAR
PERSPECTIVE AT THIS TIME IS FAIRLY NON ACTIVE, ESPECIALLY IN THE
WESTERN PLAINS. THE CONVECTIVE ALLOWING MODELS ESPECIALLY THE HRRR
WERE GENERALLY MORE ACTIVE FOR LATER THIS AFTERNOON THAN IS
CURRENTLY OCCURRING. BETTER CHANCES FOR ADDITIONAL ROUNDS OF
SHOWERS AND ISOLATED THUNDERSTORMS MAY OCCUR IN OUR WESTERN
COUNTIES, INCLUDING GCK, BY MID EVEING OR LATER, INTO THE
OVERNIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 87 65 90 / 40 30 10 0
GCK 66 88 65 91 / 50 20 10 0
EHA 66 90 66 92 / 50 10 10 10
LBL 68 89 68 92 / 40 20 10 0
HYS 65 88 65 91 / 10 20 10 10
P28 68 87 67 89 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1210 PM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1210 PM CDT TUE AUG 11 2015
THE AVIATION SECTION HAS BEEN UPDATED FOR THE 18Z TAF ISSUANCE.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
A FINAL BATCH OF SHOWERS WILL MOVE SOUTH THROUGH CARTER AND RIPLEY
COUNTIES IN MISSOURI EARLY THIS MORNING...THEN THE REMAINDER OF
THE SHORT TERM FORECAST IS DRY. THIS AFTERNOON...THE 00Z NAM IS
ATTEMPTING TO DEVELOP SOME SHALLOW CONVECTION. LOOKING AT ITS
SOUNDINGS FROM ACROSS THE REGION...IT APPEARS THERE WILL BE
SUBSTANTIAL COOLING IN THE 850MB TO 700MB LAYER...AND POSSIBLY
JUST ENOUGH LOW-LEVEL MOISTURE LEFT TO CREATE A SHALLOW LAYER OF
INSTABILITY BENEATH THE MID-LEVEL INVERSION. THE HRRR DEVELOPS A
FEW LIGHT SHOWERS...WHICH WOULD PROBABLY NOT EVEN MEASURE...SO
WILL KEEP THE FORECAST DRY FOR NOW.
SURFACE HIGH PRESSURE WILL BUILD ACROSS THE REGION TODAY INTO
WEDNESDAY...AND THE FLOW ALOFT WILL BE NORTHWESTERLY AND FAIRLY
HEALTHY FOR THE MIDDLE OF AUGUST. NORTH WINDS UP TO 10KTS WILL MIX
DOWN EACH DAY...AND THAT WILL BRING COOLER AND MUCH DRIER AIR INTO
THE REGION. DEWPOINTS BY THE END OF THE DAY WEDNESDAY WILL BE IN
THE LOWER HALF OF THE 60S...AND UPPER 50S ARE EXPECTED BY DAYBREAK
THURSDAY IN THE EAST...AS THE SURFACE HIGH SETTLES OVERHEAD.
SHOULD SEE A DEFINITE TREND LOWER IN LOW TEMPERATURES FROM THIS
MORNING THROUGH WEDNESDAY NIGHT/THURSDAY MORNING...WITH WEAKENING
WINDS AND EVER DRIER AIR OVER THE REGION. HIGHS WILL TREND LOWER
TODAY AND WEDNESDAY AND THEN LEVEL OUT ON THURSDAY. DID NOT STRAY
FAR FROM THE CONSENSUS OF 00Z GUIDANCE FOR HIGHS OR LOWS THROUGH
THE PERIOD.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 240 AM CDT TUE AUG 11 2015
THE UPPER LEVEL RIDGE THAT HAS BEEN PERSISTENT ACROSS THE HIGH
PLAINS AND ROCKIES MOST OF THE SUMMER WILL REMAIN IN PLACE. THIS
RIDGE WILL BUILD NORTHEAST ACROSS THE GREAT LAKES REGION. AN UPPER
LEVEL TROUGH WILL MAINTAIN ITS PRESENCE OVER THE EASTERN STATES...
BUT UNDERGO A WEAKENING TREND AS IT SITS OVER THE APPALACHIANS. THE
NET RESULT FOR OUR REGION WILL BE A CONTINUATION OF DRY WEATHER.
SURFACE HIGH PRESSURE WILL REMAIN STATIONARY FROM THE CENTRAL PLAINS
TO THE OHIO VALLEY THROUGH THE WEEKEND. WITH LITTLE IN THE WAY OF
TEMPERATURE ADVECTION...HIGHS WILL REMAIN GENERALLY STEADY IN THE
UPPER 80S TO NEAR 90. BY EARLY NEXT WEEK...THE HIGH WILL RETREAT
SLOWLY TOWARD THE EAST...WHICH WILL PRODUCE A SOUTHWEST FLOW OF
SLIGHTLY HIGHER TEMPS AND DEW POINTS.
&&
.AVIATION...
ISSUED AT 1210 PM CDT TUE AUG 11 2015
ASIDE FROM THE POSSIBILITY OF MVFR FOG AT KCGI/KPAH BETWEEN
08-12Z...SURFACE HIGH PRESSURE AND RISING HEIGHTS ALOFT
OVERSPREADING THE REGION SHOULD YIELD VFR CONDITIONS...ALTHOUGH A
COUPLE OF SITES COULD SEE CIGS THIS AFTERNOON IN THE 035-040
RANGE. NORTHERLY WINDS AROUND 10-12 KNOTS GUSTING UP TO 15 KNOTS
THIS AFTERNOON WILL GO CAM OR LIGHT OUT OF THE NORTH AFTER 00-01Z.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DRS
LONG TERM...MY
AVIATION...JP
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1245 PM CDT TUE AUG 11 2015
.AVIATION...
MOST TERMINAL SITES ARE VFR AT MIDDAY WITH THE EXCEPTION OF
KBTR...WHERE MVFR CEILINGS ARE OCCURRING WITH THUNDERSTORMS WEST
AND NORTHWEST OF THE TERMINAL. EVEN THOUGH THERE IS A FAIRLY
HEALTHY CIRRUS SHIELD...REDEVELOPMENT OF TSRA IS NOT OUT OF THE
QUESTION. WILL BE CARRYING VCTS AT MOST TERMINALS AT SOME POINT
THIS AFTERNOON WITH THE EXCEPTION OF KMCB...WHERE THE THREAT
APPEARS TO BE LOWER WITH THE PASSAGE OF THE MID-MORNING CLUSTER OF
THUNDERSTORMS.
OVERNIGHT...ANTICIPATE VFR CONDITIONS AT ALL TERMINALS...BUT THERE
IS AT LEAST A SMALL POTENTIAL FOR MVFR VISIBILITIES AT KMCB.
THREAT NOT LOW ENOUGH TO CARRY AT THIS TIME. 35
&&
.PREV DISCUSSION... /ISSUED 348 AM CDT TUE AUG 11 2015/
SHORT TERM...
CONSIDERABLY DRIER COLUMN WITH LOWER DEWPOINTS OVER THE LARGER
SOUTHEAST REGION THIS MORNING...WHICH SHOULD HELP IN LOWERING
APPARENT TEMPERATURES BY A FEW DEGREES THIS AFTERNOON TO PRECLUDE
A HEAT WARNING. THE UPDATED TEMPERATURES AND HUMIDITY GRIDS YIELD
PROJECTED HEAT INDEX READINGS THAT ALIGN WELL WITH ONGOING HEAT
ADVISORY...WHERE 108 TO 112F IS POSSIBLE PRIOR RAINFALL ONSET.
THERE IS SOME UNCERTAINTY ON WHETHER TEMPERATURES WILL ACHIEVE
CRITERIA SHOULD RAINFALL ONSET SOONER...AS INDICATED BY HRRR AND
CONSIDERATIONS FOR DEVELOPING LINEAR MCS DEVELOPING AT THE ARK-
LA-MISS APEX. SOME DOWNRANGE DEVELOPMENT MAY TAKE PLACE BEFORE
SUNRISE THAT MOVES INTO SOUTHWEST MISSISSIPPI AND DISRUPT THE
DIURNAL TEMPERATURE TREND. MODELS ARE IN AGREEMENT WITH INCREASING
PRECIPITATION OVER A LARGE EXPANSE OF THE GULF COAST BY THIS
AFTERNOON AND WENT WITH MODEL BLENDS ON POPS AND TEMPERATURES IN
THE SHORT-TERM. MARGINAL RISK OF SEVERE STORMS TODAY WITH MAIN
THREATS DAMAGING WIND GUSTS THOUGH ISOLATED HAIL CAN NOT BE RULED
OUT AS WET-BULB ZERO LEVELS LOWER WITH STEEP HEIGHT FALLS
THROUGHOUT THE DAY. WEDNESDAY SHOULD SEE DRIER CONDITIONS THOUGH
DAYTIME TEMPERATURES MAY STILL REACH MID 90S WITH LOWER HUMIDITY
LEVELS. 24/RR
LONG TERM...
UPPER RIDGE MOVES OVER DESERT SOUTHWEST AND STRENGTHENS WHILE DEEP
TROUGHING TAKES PLACE OVER THE EASTERN UNITED STATES WEDNESDAY AND
STAYS PLANTED ALONG THE EASTERN SEABOARD THROUGH FRIDAY BEFORE
LIFTING OUT OVER THE WEEKEND. SOME ENERGY IN THE BASE OF THE
TROUGH BREAKS OFF IN TIME TO BRING CUT-OFF LOW DYNAMICS DRIFTING
ALONG THE NORTH GULF COAST INTO NEXT WEEK. THIS TYPICALLY YIELDS
LOWER CONVECTIVE TEMPERATURE CONDITIONS WITH SOME COLD POOL
ENHANCEMENTS FOR EFFICIENT SEA BREEZE CONVECTION THAT SPREADS
LARGE ANVIL CANOPY OVER MUCH OF THE FORECAST AREA IN THE MID TO
LATE AFTERNOON HOURS THAT ERODE BY LATE EVENING. TEMPERATURES AND
RAIN CHANCES SHOULD BE CLOSE TO NORMAL LEVELS DURING THE EXTENDED
PORTIONS OF THE FORECAST PACKAGE. 24/RR
AVIATION...
2Z PACK WILL TRY TO TIME TSTORM COVERAGE PER TERMINAL. MOST SHOULD
SEE SOME ACTIVITY LATER TODAY. SHOULD START OUT DURING THE MORNING
FOR THE NORTHERN MOST SITES THEN PROGRESS SOUTHWARD DURING THE DAY.
WILL SHOW IFR CONDITIONS AS TEMPO GROUPS WILL BRING VIS RESTRICTIONS
AND WIND SPEEDS AND SHIFTS WILL BE A PROBLEM.
MARINE...
WINDS WILL BE MAINLY LESS THAN 10 KNOTS ALONG COASTAL
WATERS AND LAKE WITH SHORT DURATIONS OF 10 TO 15 IN THE AFTERNOON
AND EARLY EVENING HOURS POSSIBLE. THE MAIN CONCERN FOR THE NEXT
SEVERAL DAYS WILL BE THE POTENTIAL FOR THUNDERSTORMS...AS ANY STORMS
THAT DEVELOP COULD CERTAINLY PRODUCE WINDS IN EXCESS OF 40 KNOTS.
OUTSIDE OF THE THUNDERSTORM POTENTIAL EXPECT MOSTLY TRANQUIL
CONDITIONS. A WEAK FRONT WILL MOVE INTO THE COASTAL WATERS WEDNESDAY
WHICH WILL BRING SOME RELIEF FROM OPPRESSIVE HEAT AND HUMIDITY.
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...HEAT ADVISORY ALL LAND AREAS EXCEPT EXTREME COASTAL SOUTHEAST LA
AND COASTAL MISSISSIPPI THROUGH 7 PM.
RIVER FLOOD WARNING ON MISSISSIPPI RIVER AT RED RIVER
LANDING.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 94 74 94 72 / 50 40 10 0
BTR 95 77 96 75 / 50 40 10 0
ASD 95 74 94 73 / 50 40 40 10
MSY 95 78 93 79 / 40 40 40 20
GPT 92 76 92 75 / 40 50 50 10
PQL 93 75 94 73 / 30 60 40 10
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ034>037-039-040-
046>050-056>065-071-072.
GM...NONE.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR MSZ068>071-077.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE
ROCKIES/WRN PLAINS AND A TROF OVER ERN NAMERICA...RESULTING IN NNW
FLOW OVER THE UPPER GREAT LAKES EARLY THIS MORNING. UPSTREAM IN NRN
ONTARIO...SATELLITE IMAGERY AND SFC OBS SHOW LOW CLOUDS STEADILY
MOVING S AND NOW SPREADING OUT OVER FAR NRN LAKE SUPERIOR. THESE
CLOUDS WILL BE THE MAIN FCST ISSUE FOR TODAY. TO THE NW...FOCUSED
WAA REGIME IN MANITOBA IS PRODUCING SHRA/TSTMS EARLY THIS MORNING. A
SIMILAR SETUP MAY OCCUR LATE TONIGHT IN NRN ONTARIO/FAR NE MN AND
WRN LAKE SUPERIOR.
SATELLITE TRENDS AND GOOD AGREEMENT AMONG MODELS POINT TO A RAPID
INCREASE IN LOWER CLOUDS OVER NRN UPPER MI DURING THE NEXT SEVERAL
HRS. WITH OBS VERY SPARSE OVER NRN ONTARIO...TOUGH TO GAUGE HOW LOW
THE CLOUDS WILL BE AND WHETHER THERE MAY BE A RISK OF -DZ. THE ONLY
OB REPORTING CLOUDS IS AT GERALDTON...AND THE CIG THERE HAS BEEN
ABOVE 2KFT...NOT REALLY SUPPORTIVE OF -DZ. HOWEVER...THERE WAS ONE
OB THAT DID INDICATE -DZ. INITIALLY...PLANNED TO DROP PATCHY -DZ
MENTION OVER NCNTRL UPPER MI. HOWEVER...GIVEN THE ONE OB OF -DZ AND
THE POTENTIAL FOR THE WARMER WATERS OF SCNTRL LAKE SUPERIOR TO
FURTHER AID LOW CLOUD DEVELOPMENT IN FAVORABLE UPSLOPE FLOW...OPTED
TO RETAIN MENTION. 850MB THERMAL TROUGH OVER THE AREA TODAY SHOULD
ALLOW PLENTY OF STRATUS AND STRATOCU TO PERSIST WELL INTO THE AFTN
OVER MOST OF THE FCST AREA BEFORE STEADY CLEARING FROM THE W AND NW.
NNW WINDS GUSTING TO AROUND 25 MPH WILL BE AN ISSUE FOR MARINE
INTERESTS...ESPECIALLY ON LAKE SUPERIOR TO THE E OF THE HURON
ISLANDS AND ON NRN LAKE MICHIGAN. THE BREEZY NNW WINDS WILL MEAN
COOLEST CONDITIONS ALONG LAKE SUPERIOR OVER THE E WHERE LAKESIDE
TEMPS WILL BE IN THE LOW/MID 60S DURING THE DAY. MAX TEMPS IN THE
LOW/MID 70S ARE EXPECTED WELL INLAND...WARMEST FAR SCNTRL.
SFC HIGH PRES RIDGE MOVES OVER THE AREA TONIGHT...RESULTING IN
LIGHT/CALM WIND. WITH CLEAR SKIES FOR MUCH OF THE NIGHT...FAVORED
THE LOWER END OF AVBL GUIDANCE. INLAND FROM LAKE SUPERIOR...MANY
LOCATIONS SHOULD FALL TO THE 40S FOR MINS...WITH TRADITIONAL COLD
SPOTS TUMBLING TO AS LOW AS THE LWR 40S. LATE TONIGHT...THE SAME
FOCUSED WAA LEADING TO CONVECTION IN MANITOBA EARLY THIS MORNING
WILL BE POSITIONED IN NRN ONTARIO/FAR NE MN/WRN LAKE SUPERIOR. ALL
MODEL GUIDANCE POINT TOWARD REDEVELOPMENT OF CONVECTION IN THAT AREA
MOSTLY AFTER 06Z. WILL MAINTAIN SCHC POPS FOR SHRA/TSRA OVER NW LAKE
SUPERIOR INCLUDING ISLE ROYALE AFTER 08Z. WOULDN`T BE SURPRISED IF
LATER FCSTS NEED TO RAISE POPS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 313 AM EDT TUE AUG 11 2015
OTHER THAN SATURDAY-SATURDAY NIGHT...MUCH OF THIS PERIOD WILL BE
DOMINATED BY A 500MB TROUGH OF LOW PRESSURE FROM CANADA.
WE WILL BE RETURNING TO A SUMMER-LIKE PATTERN WITH ABOVE NORMAL
TEMPERATURES. NORMAL HIGHS ARE IN THE MID TO UPPER 70S. UPPER 70S TO
LOW 80S WILL BE MORE COMMON THROUGH AT LEAST SUNDAY. HOWEVER...EVEN
THROUGH THERE ARE SLIGHT TO SMALL CHANCES OF PRECIP...DRY CONDITIONS
WILL BE MORE LIKELY. EVEN THE LATEST 5-DAY WPC PRECIP GRAPHIC HAS
ONLY 0.10 TO LESS THAN 0.5IN AVERAGE PRECIP THROUGH 00Z SUNDAY.
THE INITIAL 500MB LOW OVER QUEBEC AT 12Z WILL EXTEND A TROUGH ACROSS
MUCH OF THE GREAT LAKES REGION AND EASTERN U.S...WHILE A RIDGE
REMAINS OVER MUCH OF THE CENTRAL PORTIONS OF THE NATION. WHILE THE
RIDGE WILL ATTEMPT TO BUILD OVERHEAD WEDNESDAY...UP IN CENTRAL-N
CANADA THE NEXT WAVE WILL BE NEARING.
WAA WEDNESDAY BEHIND THE EXITING SFC RIDGE WILL ALLOW FOR SHOWERS TO
SHIFT W-E OVER THE CWA DURING THE DAY. EVEN THE NAM HAS COME AROUND
TO AT LEAST A FEW HUNDREDTHS OF PRECIP. STILL NOT EXPECTING MUCH...IN
THE WAY OF PRECIP OR THUNDERSTORMS. 25-35KT WINDS LOOK TO BE JUST
ABOVE THE SFC WEDNESDAY NIGHT...BUT WITH A PRETTY STRONG INVERSION
IN PLACE...DON/T EXPECT MUCH OF THOSE TO GET REALIZED AT THE SFC.
STILL DON/T EXPECT A CALM NIGHT EITHER...WITH WINDS REMAINING 6-
13KTS...STRONGEST OVER W HALF.
THE SFC LOW STILL IN N CANADA WEDNESDAY NIGHT WILL BRING A COLD
FRONT TO THE NW HALF OF MN BY 12Z THURSDAY. THERE IN UNCERTAINTY IN
JUST HOW MUCH AND HOW WIDESPREAD SHOWERS WILL BE THURSDAY WITH THE
PASSAGE OF THE COLD FRONT...WHICH WILL MOVE TO THE SE OF THE CWA
SHORTLY AFTER 06Z FRIDAY. THE MAIN SHORTWAVE ENERGY WILL SWING
ACROSS ONTARIO...JUST TO OUR N. THE SOUNDING OFF THE NAM LOOK PRETTY
DRY...WITH EVEN LIMITED CLOUD COVER.
WITH THE COLD FRONT JUST TO OUR S FRIDAY...S CENTRAL UPPER MI COULD
STILL BE ABLE TO GET A SLIGHT CHANCE OF SHOWERS/TSTORMS.
OTHERWISE...DRY HIGH PRESSURE OVER THE N PLAINS AND S CENTRAL CANADA
THURSDAY NIGHT WILL BUILD ACROSS THE UPPER GREAT LAKES THROUGH
SATURDAY MORNING.
THE NEXT CANADIAN LOW AROUND SASKATCHEWAN SATURDAY MORNING WILL
SHIFT ACROSS ONTARIO/HUDSON BAY BY 12Z SUNDAY...AND DRAG THE NEXT
COLD FRONT ACROSS THE UPPER GREAT LAKES SUNDAY OR SUNDAY NIGHT.
TIMING IS A CONCERN...SO WILL CONTINUE TO GO WITH A GENERAL BLENDED
SOLUTION FOR SUNDAY THROUGH MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 129 PM EDT TUE AUG 11 2015
MVFR CIGS WILL BE MOVING OUT THIS AFTERNOON AS DRIER AIR AND MIXING
MOVE IN AT ALL SITES. VFR CONDITIONS WILL CONTINUE THEN AT ALL SITES
THROUGH THE FORECAST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 521 AM EDT TUE AUG 11 2015
WITH SFC HIGH PRES RIDGE APPROACHING FROM THE W...NNW WINDS WILL BE
FAIRLY BRISK OVER ERN LAKE SUPERIOR TODAY...WITH GUSTS FREQUENTLY
AROUND 20KT. OVER WRN LAKE SUPERIOR...WINDS WILL BE LIGHTER...
ESPECIALLY IN THE AFTN AS MESO HIGH PRES DEVELOPS OVER THE WRN LAKE.
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TONIGHT/WED
MORNING. WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW WED
AFTN OVER WRN LAKE SUPERIOR AS THE HIGH PRES RIDGE DRIFTS E. THESE
SW WINDS OF 10-20KT WILL CONTINUE INTO THU AHEAD OF COLD FRONT
APPROACHING FROM THE NW. DEPENDING HOW MUCH THE PRES GRADIENT
TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF GUSTS TO INCREASE
TO THE 20-30KT RANGE...ESPECIALLY AT THE HIGH OBS PLATFORMS. THE
STRONGEST GUSTS WOULD OCCUR OVER WRN LAKE SUPERIOR. WINDS WILL
DIMINISH AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON
FRI AS HIGH PRES BUILDS INTO THE UPPER LAKES. THESE LIGHTER WINDS
WILL LINGER INTO AT LEAST SAT MORNING BEFORE WINDS BEGIN TO INCREASE
AGAIN AHEAD OF THE NEXT APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...07
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1218 PM CDT TUE AUG 11 2015
.DISCUSSION...
Issued at 314 AM CDT TUE AUG 11 2015
Slightly below normal temperatures and significantly lower humidity
throughout the region today will allow maximum heat indices to fall
nearly 15 degrees from yesterday`s max values, and will feel like a
brief reprieve from summer after days of sticky conditions. North
northeasterly surface winds will remain sustained at ~10-12 mph
through the day as the pressure gradient tightens in response to
surface high pressure building over north central KS, which will
also promote additional mixing out of low-level moisture on top of
the dry air advection already occurring. Felt that the RAP had the
right idea but was a little overdone in mixing to nearly 750 hPa, so
balanced between the RAP`s and HRRR`s warmer/drier solution with
consensus model solutions to bring highs into the mid 80s in most
locations this afternoon, and dewpoints into the lower 60s.
Upper-level high pressure over the desert southwest will expand and
bulge eastward over the next several days, keeping the forecast area
fully entrenched in northwest to northerly flow aloft through the
work week and into the weekend. At the surface, persistent high
pressure will very gradually drift and build to the southeast,
abating winds and mixing for Wednesday, then eventually allowing
weak southerly flow to return late Thursday or early Friday.
Sunshine should be abundant and precipitation chances nil this week
as the blocking upper high prevents even the most ambitious short-
wave energy from riding the length of the ridge and down into the
region. When the upper high finally begins to retreat southwest and
break down, ridging will edge northeastward into the upper Midwest,
bringing the thermal ridge closer to the forecast area and allowing
temperatures to return to the lower 90s for the weekend. Storm
chances don`t return until very late in the period when upper-level
flow finally flattens to zonal and a shortwave trough slides through
the central Plains, but timing of this feature continues to slow,
and its northern track could limit the possibility of precipitation
in the majority of the CWA.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1209 PM CDT TUE AUG 11 2015
VFR CIGS and VIS are expected through the period as the region is
under dry deep-layer northwesterly flow. The surface winds will
remain light and out of the northeast as well.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Laflin
AVIATION...Pietrycha
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
145 PM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 1028 AM CDT TUE AUG 11 2015
HIGH PRESSURE DOMINATING AT THE SURFACE AND ALOFT THIS MORNING.
CLOUDS LIFTING NORTHEAST AND GENERALLY DISSIPATING EAST OF HIGHWAY
83. THE SURFACE AND UPPER RIDGE BUILDS EAST TODAY WHERE ISOLATED
TO SCATTERED CONVECTION WILL BE POSSIBLE IN THE PANHANDLE AND FAR
SOUTHWEST. NO SEVERE STORMS ARE ANTICIPATED WITH ISOLATED
THUNDERSTORMS THAT DO FORM CAPABLE OF HEAVY RAINFALL AND SMALL
HAIL. FORECAST GRIDS AND TEST PRODUCTS UPDATED TO REFLECT LOW
POPS IN THE WEST THROUGH THE AFTERNOON AND INTO TONIGHT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CDT TUE AUG 11 2015
TODAY AND TONIGHT...THE MODELS ARE HOLDING A STATIONARY FRONT ACROSS
THE PANHANDLE TODAY. THE RAP SHOWS A MODEST LOW LEVEL JET ANCHORED
OVER THAT REGION ALL DAY. MOISTURE...STEEP LAPSE RATES AND LIFT ARE
FORCING TSTMS IN THIS AREA WHICH WOULD PROBABLY DRIFT EAST TODAY.
SINCE NONE OF THE MODELS HAVE A HANDLE ON THE CONVECTION UNDERWAY...
ISOLATED POPS WITH LOCALLY HEAVY RAINFALL ARE IN PLACE THIS MORNING.
THE RAP SUGGESTED AN ISOLATED TSTM MOVING OFF THE BLACK HILLS TOWARD
VALENTINE THIS AFTERNOON. CONSALL...ALLBLEND AND OTHER DATA SETS
SUGGESTED ISOLATED POPS ACROSS WRN NEB TODAY AND FAR SWRN NEB
TONIGHT.
THE NAM...SREF...ARW AND NMM MODELS INDICATE STRATUS MAY MOVE NORTH
INTO THE PANHANDLE TONIGHT. THIS IS ASSOCIATED WITH A LOW LEVEL JET
ANCHORED ALONG A STATIONARY FRONT. THIS FEATURE WILL BE ANALYZED
MORE CAREFULLY TODAY.
HIGHS TODAY RISE INTO THE MID AND UPPER 80S...A BIT WARMER THAN
YESTERDAY WITH LOWS TONIGHT IN THE UPPER 50S TO NEAR 60. DEW POINTS
REMAIN IN THE LOW TO MID 60S.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 352 AM CDT TUE AUG 11 2015
THE LONG RANGE MODELS CONTINUE TO INDICATE THE PRESENCE OF AN UPPER
LEVEL RIDGE EXTENDING NORTH FROM THE DESERT SOUTHWEST ACROSS THE
ROCKIES AND ONTO THE CENTRAL PLAINS OF SASKATCHEWAN/ALBERTA. THIS
PATTERN IS FORECAST TO REMAIN IN PLACE INTO THE WEEKEND...BUT THEN
BREAKDOWN AS A PAC NW SHORTWAVE ADVANCES NORTHEAST TOWARD THE
CANADIAN PRAIRIES. THE MODELS CONTINUE TO INDICATE PERIODIC CHANCES
OF QPF AS DISTURBANCES RIDE ATOP THE RIDGE...HOWEVER THE GREATEST
CHANCES LOOK TO REMAIN NEAR THE HIGHER TERRAIN OF EASTERN
COLORADO/WYOMING AND THE WESTERN PANHANDLE. THE BEST CHANCE OF A
RIDGE RIDER SPILLING ACROSS SOUTHWEST NEB OR THE CENTRAL SANDHILLS
WILL BE THURSDAY EVENING...BUT AT THAT...WILL ENTERTAIN NO BETTER
THAN A SLIGHT CHANCE OF THUNDER FOR NOW AS THE MODELS HAVE STRUGGLED
WITH CONSISTENCY AND TIMING OF THESE LOWER AMPLITUDE FEATURES. THE
AFOREMENTIONED SHORTWAVE WILL PULL A COLD FRONT ACROSS THE FORECAST
AREA SATURDAY INTO SUNDAY...LEADING TO THE POSSIBILITY OF STORMS
INTO EARLY NEXT WEEK. THE GFS AND ECMWF ARE AT ODDS WITH THE TIMING
OF THE FRONT /AND ASSOCIATED SHORTWAVE PASSAGE/...WITH THE GFS THE
MOST AGGRESSIVE. THE CR_INT BLENDED PROCEDURE TRIED TO INTRODUCE
WIDESPREAD LIKELY POPS INTO THE FORECAST FOR THE PASSAGE...WHICH WAS
DEEMED TOO HIGH /BEING DAYS 5-7/. THUS THE FORECAST POPS WERE
LOWERED ACCORDINGLY.
LOWER TROPOSPHERIC THERMAL ADVECTION AND INCREASING SUBSIDENCE
ASSOCIATED WITH THE UPPER LEVEL RIDGE OF HIGH PRESSURE WILL PROMOTE
WARMING TEMPERATURES INTO THE WEEKEND. HIGHS ARE FORECAST TO BE
ABOVE CLIMO BY LATE WEEK AND REMAIN THROUGH SATURDAY. SEASONAL TO
SLIGHTLY ABOVE AVERAGE LOWS ARE FORECAST WITH THIS TYPICAL AUGUST
PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 138 PM CDT TUE AUG 11 2015
VISUAL FLIGHT RULES WILL CONTINUE FOR TERMINALS KLBF AND KVTN
THROUGH 18Z WEDNESDAY. THE SURFACE TROUGH NEAR THE FOOTHILLS WILL
HELP CHANNEL MID LEVEL MOISTURE NORTH WHERE CEILINGS BETWEEN 5
KFT TO 8 KFT ARE POSSIBLE THIS AFTERNOON. OVERNIGHT CLOUD COVERAGE
WILL BECOME MORE SCATTERED INTO THURSDAY MORNING AS THE UPPER
RIDGE BUILDS AND SHIFTS EAST. THE CHANCE FOR ISOLATED THUNDERSTORMS
WILL FOCUS MAINLY ACROSS THE SOUTHWEST FORECAST AREA.
&&
.HYDROLOGY...
ISSUED AT 351 AM CDT TUE AUG 11 2015
THE HEAVY RAIN CENTER BETWEEN KIMBLE AND SIDNEY IS SENDING AN
UNKNOWN QUANTITY OF WATER INTO LODGEPOLE CREEK WHICH DRAINS INTO
DEUEL COUNTY. THE CREEK GENERALLY FOLLOWS A ROUTE EAST BETWEEN
I-80 AND HIGHWAY 30 AND THEN HOPEFULLY CROSSES UNDER I-80
SOUTHEAST OF CHAPPELL. AT 3 AM CDT...ABOUT 2 TO 4 INCHES OF RAIN
WAS RADAR ESTIMATED WITH THE HEAVY RAIN CENTER. DAYLIGHT WILL
REVEAL THE HEIGHT OF THE WATER FLOWING EAST. NO GAGES OTHER THAN A
STAFF GAGE 6 MILES SOUTHEAST OF CHAPPELL ARE IN PLACE TO MEASURE
THE CREEK LEVEL. IT IS NORMALLY DRY. THE CHAPPELL GAGE HAS READ AS
HIGH AS 6.5 FEET IN 1968. THE STREAM TRAVEL FLOW RATE HAS BEEN
ESTIMATED AT 2 TO 4 MILES AN HOUR WHICH WOULD PUT WATER IN DEUEL
COUNTY THIS AFTERNOON.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KECK
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...KECK
HYDROLOGY...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
ISSUED BY NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
1252 PM CDT TUE AUG 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT TUE AUG 11 2015
THE SHORT TERM FORECAST REMAINS FAIRLY QUIET THROUGH THE NEXT 24
HOURS...WITH DRY CONDITIONS AND VERY LITTLE CHANGES MADE TO THE
PREVIOUS FORECAST. AN UPPER LEVEL RIDGE REMAINS DOMINATE ACROSS THE
SOUTHERN HALF OF THE CONUS...WHILE A DEEP UPPER LEVEL CLOSED LOW
TRUDGES OFF THE PACIFIC COASTLINE. AN OPEN WAVE HAS BEGUN TO SLIDE
EASTWARD ACROSS THE GREAT LAKES REGION. THE RIDGE AXIS IN THE MID
LEVELS IS SLIGHTLY MORE PRONOUNCED AND AMPLIFIED ACROSS THE FRONT
RANGE. ALONG THIS RIDGE AXIS...RETURN FLOW COMBINED WITH WARM AIR
ADVECTION HAS ALLOWED MOISTURE TO SURGE NORTHWARD ALONG THE FRONT
RANGE. AT THE SURFACE HIGH PRESSURE HAS SHIFTED ACROSS THE CENTRAL
PLAINS. LATEST OBS REFLECT THIS FEATURE AS MOST AIRPORT WINDS ARE
LIGHT TO CALM.
ALTHOUGH THIS IS NOT REFLECTED IN THE FORECAST...THERE ARE SOME
CONCERNS ABOUT PATCHY FOG DEVELOPMENT THIS MORNING. EVEN THOUGH
DEWPOINTS ARE LOWER THAN PREVIOUS DAYS...TEMPERATURES ARE ALSO
SLIGHTLY COOLER. AT THE PRESENT TIME...RELATIVE HUMIDITY VALUES ARE
ABOVE 90 PERCENT IN MOST AREAS. MODEL SOLUTIONS SUCH AS THE
NAM...RAP...AND HRRR ALL SUGGEST LOWERED VISIBILITIES ESPECIALLY FOR
LOCATIONS WEST OF 281...MAINLY ALONG THE SURFACE RIDGE AXIS. SINCE
THIS WILL LIKELY BE PATCHY IN NATURE...WILL CONTINUE TO MONITOR
LATEST TRENDS BEFORE INTRODUCING INTO GRIDS.
THE REST OF TODAY LOOKS TO REMAIN QUIET AS THE SURFACE RIDGE SLIDES
THROUGH THE AREA. LIGHT WINDS ARE EXPECTED AND HIGH TEMPERATURES
SHOULD TOP OUT NEAR NORMAL WITH HIGHS IN THE MID 80S FOR MOST
LOCATIONS. FURTHER WEST...A SMALL DISTURBANCE WILL DEVELOP ALONG THE
FRONT RANGE...AND COMBINED WITH MOISTURE AND WARM AIR ADVECTION WILL
LIKELY SPAWN THUNDERSTORMS. 0Z MODEL SOLUTIONS PULLED POPS BACK
FURTHER WEST AND THUS WENT AHEAD AND REMOVED ANY MENTION OF
THUNDERSTORMS FROM WESTERN ZONES TUESDAY NIGHT. HOWEVER...WOULD NOT
BE SURPRISED TO SEE A STORM MAKE A RUN FOR THE WESTERN ZONES DURING
THIS TIME FRAME. EVEN THE 6Z NAM...HAS NOW REVERTED BACK TO POPS IN
NORTH CENTRAL KANSAS BY EARLY MORNING WEDNESDAY.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 339 AM CDT TUE AUG 11 2015
AN UPPER RIDGE OF HIGH PRESSURE WILL BE THE DOMINATE WEATHER FEATURE
ACROSS THE INTERIOR CONUS THROUGH THE WORKWEEK. THE PATTERN WILL BE
BLOCKY AT THE START WITH CLOSED LOWS IN THE PACIFIC OCEAN OFF THE
COAST OF CALIFORNIA AND ANOTHER TROUGH ALONG THE EAST COAST. UNDER
THE INFLUENCE OF THE RIDGE...PRECIPITATION CHANCES WILL BE
NEGLIGIBLE UNTIL THE WEEKEND TIME FRAME WHEN THE WESTERN LOW LIFTS
OUT AND BREAKS DOWN THE INTERIOR CONUS RIDGE. ALTHOUGH THE FORECAST
REMAINS DRY UNTIL SATURDAY NIGHT WILL NEED TO KEEP AN EYE ON
CONVECTION WHICH DEVELOPS ALONG THE HIGHS PLAINS AS ACTIVITY MAY TRY
TO WORK INTO OUR WESTERN ZONES.
THE PATTERN CHANGE ARRIVES OVER THE WEEKEND AS THE AFOREMENTIONED
WESTERN SYSTEM LIFTS OUT AND CROSSES THE NORTHERN CONUS. AN
ASSOCIATED COLD FRONTAL BOUNDARY ADVANCES SOUTH FROM THE DAKOTAS
LATE SATURDAY WITH CHCS FOR TSTMS RETURNING AS FRONT ARRIVES. THE
ECMWF IS SLOWER WITH BOUNDARY PROGRESSION THAN THE GFS BUT HARD TO
PINPOINT THE DETAILS THIS FAR OUT. THE BOUNDARY IS PROGGED TO STALL
OR MEANDER ACROSS OUR REGION INTO EARLY NEXT WEEK AND WITH BOUNDARY
IN THE AREA CHANCES FOR STORMS CONTINUE. TEMPERATUREWISE...READINGS
WILL BE TYPICAL OF SUMMER WITH HIGHS IN THE 80S TO LOW 90S...WITH
LOWS IN THE 60S TO LOWER 70S.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1252 PM CDT TUE AUG 11 2015
VFR CONDITIONS UNDER MOSTLY CLEAR SKIES ARE FORECAST THROUGH
WEDNESDAY MORNING. THERE IS A SMALL CHANCE MVFR FOG COULD DEVELOP AT
CENTRAL NEBRASKA TAF SITES NEAR 12Z...BUT CHANCES ARE TOO LOW TO
MENTION AT THIS TIME.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...SALTZMAN
LONG TERM...FAY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1017 AM PDT TUE AUG 11 2015
.SYNOPSIS...BREEZY CONDITIONS ARE EXPECTED TODAY IN THE OWENS
VALLEY WHILE MONSOON MOISTURE WORKING BACK INTO THE AREA WILL
INCREASE THUNDERSTORM CHANCES IN MOHAVE COUNTY. THUNDERSTORM CHANCES
THEN SPREAD INTO CLARK...LINCOLN...AND SAN BERNARDINO COUNTIES BY
WEDNESDAY. TEMPERATURES WILL BE RUNNING NEAR NORMAL TO SLIGHTLY
BELOW NORMAL WHERE MOISTURE AND CLOUD COVER ARE ENHANCED...BEFORE
WARMING TO ABOVE NORMAL INTO NEXT WEEK.
&&
.UPDATE...
A NORTHWESTERLY MOVING DISTURBANCE VISIBLE ON WATER VAPOR IMAGERY
IS CURRENTLY GENERATING FAST MOVING SHOWERS AND THUNDERSTORMS OVER
PINAL AND MARICOPA COUNTIES THIS MORNING. THIS ACTIVITY IS
EXPECTED TO MOVE NORTHWESTWARD AND WILL ACT UPON AVAILABLE
MOISTURE TO GENERATE SHOWERS AND THUNDERSTORMS OVER MAINLY MOHAVE
COUNTY THIS AFTERNOON. HAVE RAISED POPS TO INCLUDE LIKELY WORDING
FOR THUNDERSTORMS...ESPECIALLY OVER NORTHERN PORTIONS OF THE
COUNTY...WITH CHANCES FURTHER WEST INTO EASTERN CLARK AND LINCOLN
COUNTIES. THE LAST SEVERAL RUNS OF THE HRRR AND LOCAL HIGH RES
MODELS CONTINUE TO SHOW A SECOND WAVE OF SHOWERS AND STORMS MOVING
INTO THE AREA OVERNIGHT INTO WEDNESDAY MORNING. POPS HAVE BEEN
ADJUSTED WESTWARD TO INCLUDE A CHANCE FOR THUNDERSTORMS IN EASTERN
PORTIONS OF SAN BERNARDINO...CLARK AND MOST OF LINCOLN COUNTIES
WEDNESDAY MORNING.
&&
.PREV DISCUSSION...327 AM PDT TUE AUG 11 2015
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT.
AN UPPER LEVEL LOW DEVELOPING SOUTHWARD OF THE WEST COAST AND HIGH
PRESSURE OVER NM/TX WILL TURN FLOW MORE SOUTHERLY WILL BRING
MONSOONAL MOISTURE FIRST MAINLY TO MOHAVE COUNTY TODAY...THEN
SPREADING FURTHER WEST OVER CLARK...LINCOLN...AND EASTERN SAN
BERNARDINO COUNTIES BY WEDNESDAY. THE SHORTWAVE MODELS HAD ROTATING
AROUND THE HIGH THIS MORNING IS MORE DIFFUSE AND FURTHER WEST WITH
THE MOST RECENT RUNS. THIS HAS RESULTED IN LESS ACTIVITY IN THE
MODELS AND LOWER CONFIDENCE IN ANY SUBSTANTIAL ACTIVITY DEVELOPING THIS
MORNING ACROSS MOHAVE COUNTY. HIGH RESOLUTION MODELS ARE IN DECENT
AGREEMENT WITH DEVELOPING MORE SUBSTANTIAL CONVECTION ACROSS MOHAVE
COUNTY THIS AFTERNOON WITH SIGNALS OF EITHER A COMPLEX OR OUTFLOW
DRIVEN ACTIVITY LINGERING UNTIL MIDNIGHT. ADDITIONALLY...ENOUGH
MOISTURE MAY HAVE SPREAD INTO CLARK COUNTY BY AROUND MIDNIGHT SUCH
THAT IF ANY OUTFLOW DOES MAKE IT AS FAR WEST...THUNDERSTORM
DEVELOPMENT CANNOT BE RULED OUT...THUS HAVE ADDED SLIGHT CHANCE OF
THUNDERSTORMS FOR THE LAS VEGAS VALLEY OVERNIGHT.
BY WEDNESDAY...MOISTURE WILL HAVE INCREASED OVER MUCH OF EASTERN SAN
BERNARDINO...CLARK...AND LINCOLN COUNTIES...WITH THE BEST MOISTURE
AND HEAVY RAIN SIGNALS STILL REMAINING OVER NORTHERN MOHAVE COUNTY.
COVERAGE ON WEDNESDAY WILL DEPEND HEAVILY ON ANY ACTIVITY TONIGHT
AND FEATURES YET TO BE RESOLVED IN THE MODELS. CURRENT FORECAST IN
GOOD SHAPE WITH MORE WIDESPREAD CHANCES INTO WEDNESDAY NIGHT.
.LONG TERM...THURSDAY THROUGH MONDAY.
MODELS ARE IN REASONABLY GOOD AGREEMENT THAT LOW TO MODERATE GRADE
MONSOON MOISTURE WILL BE IN PLACE ACROSS THE EASTERN HALF TO 2/3RDS
OF THE FORECAST AREA ON THURSDAY. WEAK CAPPING UNTIL THE AFTERNOON
AND A LACK OF DYNAMIC FEATURES (AT LEAST IN THE CURRENT GUIDANCE)
MEANS THAT STORMS WILL LIKELY BE TERRAIN DRIVEN AND ISOLATED MOVING
NORTH AT 15-20 MPH. GRADUAL DRYING TAKES PLACE THROUGH THE REMAINDER
OF THE LONG TERM...BUT THINGS NEVER DRY OUT COMPLETELY. HAVE LEFT IN
AT LEAST A SLIGHT CHANCE OF STORMS OVER AT LEAST THE HIGHER TERRAIN
OF MOHAVE COUNTY EACH DAY THROUGH MONDAY.
THE OTHER CONCERN IN THE LONG TERM PERIOD IS THE VERY HOT
TEMPERATURES THAT WILL DEVELOP BY THE WEEKEND. THE ECMWF AND GFS
GUIDANCE HAVE BOTH JUMPED UP WITH TEMPERATURES WITH THE 00Z
GUIDANCE. I RAISED TEMPERATURES TO REFLECT THAT...INTRODUCING A HIGH
OF 110F AT MCCARRAN ON SUNDAY. 110F IS THE CRITERIA AT MCCARRAN FOR
AN EXCESSIVE HEAT WATCH/WARNING DURING THIS PART OF AUGUST. HOWEVER
STILL BEING QUITE A FEW DAYS OUT AND BELOW AVERAGE INTER-MODEL AND
RUN-TO-RUN AGREEMENT I HAVE OPTED TO HOLD OFF ON ISSUING AN
EXCESSIVE HEAT WATCH WITH THIS MORNING`S FORECAST. HOWEVER THE
SATURDAY THROUGH MONDAY TIME FRAME WILL NEED TO BE MONITORED OVER
THE NEXT COUPLE DAYS.
.AVIATION...FOR MCCARRAN...CLOUDS MAY BECOME THINNER BY LATE MORNING
BEFORE INCREASING IN COVERAGE AND LOWERING TO AROUND 10K FEET THIS
EVENING. THERE IS A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM
DEVELOPING ON THE MOUNTAINS. OTHERWISE SIMILAR CONDITIONS TO
YESTERDAY ARE EXPECTED WITH GUSTY WINDS POSSIBLE AGAIN THIS
AFTERNOON AND EVENING.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...GENERAL SOUTHERLY WINDS WILL PERSIST TODAY...WITH
LOCALLY GUSTY WINDS ONCE AGAIN...ESPECIALLY IN THE OWENS VALLEY.
AREAS OF SMOKE ARE STILL POSSIBLE FROM THE WILLOW FIRE ALONG THE
COLORADO RIVER VALLEY. INCREASING MOISTURE WILL LEAD TO INCREASING
CLOUD COVER...ESPECIALLY IN WESTERN ARIZONA AND SOUTHERN NEVADA
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE...PULLIN
SHORT TERM/AVIATION...STEELE
LONG TERM...WOLCOTT
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
352 PM EDT TUE AUG 11 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TONIGHT AND INTO WEDNESDAY AS A COLD
FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT LATE WEDNESDAY...OFFERING SEASONABLE AND MAINLY
DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY RETURN EARLY
NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS MOISTURE
ONSHORE.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 300 PM TUESDAY...A TWEAK OR 2 HERE AND THERE WITH POPS FOR THE
REMAINDER OF THIS AFTN AND NIGHT...BUT OVERALL WILL CONTINUE WITH
GOOD CHANCE POPS WITH THE DAYS INSOLATION FINALLY AIDING THE
DESTABILIZING OF THE ATM WITH CONVECTION NOW FIRING ACROSS PORTIONS
OF THE ILM CWA. ONCE THE DAYS INSOLATION ENDS...GO SEE A BRIEF LULL
WITH CONVECTION THIS EVENING. AS INDICATED EARLIER...BUT THEN RAMP
BACK UP LATER THIS EVENING AND OVERNIGHT DUE TO THE APPROACH AND
PASSAGE OF CONVECTION THAT ORIGINATED UPSTREAM EARLIER THIS EVENING.
WILL CONTINUE TO MENTION 25 TO 45 MPH WIND GUSTS POSSIBLE FROM THE
STRONGER STORMS WITHIN THE HAZARDOUS WX OUTLOOK.
PREVIOUS..........................................................
AS OF 130 PM TUESDAY...HAVE TWEAKED THIS AFTN MAX TEMPS A DEGREE OR
2 LOWER FOR BASICALLY THE ILM NC COUNTIES DUE TO THE EXTENDED PERIOD
OF OVERCAST SKIES. THE ILM SC COUNTIES ACTUALLY NEEDED A DEGREE OR 2
ADJUSTMENTS HIER...MAINLY CLOSER TO THE IMMEDIATE COAST DUE TO A
SOMEWHAT PINNED SEA BREEZE DUE TO SW-WSW WINDS 25-35 KT IN THE LOWER
LEVELS...SFC THRU 700MB. STILL THINK CONVECTION WILL FIRE LATER THIS
AFTN AND EVENING DUE TO THE DAYS INSOLATION. LATEST HRRR AND WRF
INDICATE THAT CONVECTION WILL DEVELOP UPSTREAM CLOSER TO THE COLD
FRONT LATE THIS AFTN...AND MAKE A BEE-LINE TO THE ILM CWA LATER THIS
EVENING AND INTO THE PRE-DAWN WED HRS. AND ACTUALLY MAY INCREASE
INTENSITY AND/OR COVERAGE AS IT PUSHES TO THE COAST. WITH THAT ON
THE TABLE NOW...HAVE DECIDED TO KEEP THE GOOD CHANCE POPS ACROSS THE
FA WELL INTO THE NIGHT TIME HRS. HAVE BACKED OFF WITH THE COLD
FRONTS PROGRESSION TO THE COAST OVERNIGHT...AND BASICALLY NOW HAVE
IT REACHING THE I-95 CORRIDOR BY DAYBREAK WED. SOME RE-ADJUSTMENTS
TO MIN TEMPS HAVE NOW BEEN APPLIED TO ACCOUNT FOR THE COLD FRONTS
SLOWER PROGRESSION.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...TRICKY FORECAST FOR MID-WEEK DUE TO TIMING OF
A COLD FRONT WHICH WILL BE DRIFTING ACROSS THE CWA ON WEDNESDAY. GFS
SEEMS TO BE A FAST OUTLIER AND IS NOT PREFERRED...AND INSTEAD RELY
ON A NAM/ARW/WPC BLEND FOR THE PERIOD.
COLD FRONT...DRIVEN BY AN ANOMALOUSLY STRONG UPPER TROUGH ACROSS THE
EAST...WILL BE ALONG OR JUST WEST OF I-95 AT FIRST LIGHT WEDNESDAY.
THIS FRONT WILL THEN SLOWLY PUSH SE THROUGH THE DAY...LIKELY MOVING
OFFSHORE WEDNESDAY EVENING. IN THIS SETUP...CONVERGENCE WILL BE
MAXIMIZED ALONG THE FRONT WHERE NW WINDS INTERSECT SW RETURN FLOW
WINDS. GUIDANCE IS PRETTY AGGRESSIVE DEVELOPING CONVECTION ALONG
THIS BOUNDARY ACROSS THE EASTERN HALF OF THE CWA ON WEDNESDAY...IN A
REGION CHARACTERIZED BY 1000 J/KG OF SBCAPE AND PWATS AROUND 2
INCHES. HOWEVER...THE MID-LEVEL W/NW FLOW DRIVING THE FRONT WILL
CREATE VERY DRY AIR ABOVE 700MB...AND MOST OF THE HIGH-RH AIR IS IN
THE 1000-800MB LAYER. WHILE THIS SUPPORTS AT LEAST A GOOD CHC FOR
SHOWERS...THUNDERSTORMS WILL BE DIFFICULT TO COME BY THANKS TO THE
CHARGE SEPARATION LAYER BEING VERY DRY. HOWEVER...STRONG SURFACE
CONVERGENCE AND SOME PVA WILL ALLOW AT LEAST SOME UPDRAFTS TO BE
STRONG ENOUGH TO CAUSE LIGHTNING. WILL RAMP POP TO HIGH-CHC THE
EASTERN HALF OF THE CWA...WITH LOW LIKELY ALONG THE IMMEDIATE COAST.
PRECIP WILL COME TO AN END AS THE FRONT MOVES OFFSHORE LATE
WEDNESDAY.
THIS FRONT WILL REMAIN STALLED OFFSHORE ON THURSDAY...WITH DRIER AND
COOLER AIR ADVECTING INTO THE CWA BEHIND IT. MUCH OF THE DAY SHOULD
BE DRY...BUT AS WINDS SHIFT TO NE AND THEN E...SOME ATLANTIC
MOISTURE MAY ADVECT BACK ONSHORE. THIS WILL OCCUR WHILE MID-LEVEL
LAPSE RATES REMAIN STEEP THANKS TO THE UPPER TROUGH...AND A FEW
SHOWERS OR THUNDERSTORMS CANNOT BE RULED OUT THURSDAY...MOST LIKELY
WITHIN THE SOUTHERN COASTAL ZONES. TOTAL COVERAGE IS EXPECTED TO BE
ISOLATED AT WORST HOWEVER.
TEMPS WEDNESDAY AHEAD OF THE FRONT WILL RISE INTO THE UPPER 80S TO
LOWER 90S...WITH MAXIMUMS A FEW DEGREES COOLER BEHIND IT ON
THURSDAY. LOWS WEDNESDAY NIGHT WILL FALL INTO THE UPPER 60S
INLAND/LOW 70S AT THE COAST WED NIGHT...WITH MINS AGAIN A BIT COOLER
THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 300 PM TUESDAY... UPPER TROUGHINESS REMAINS IN PLACE ON
FRIDAY WITH DEEP, PRECIP SUPPORTING MOISTURE JUST OFFSHORE. THE
WRF IS RATHER ALONE IN ITS SOLUTION OF A MORE CUTOFF UPPER LOW
NEAR KSAV THAT COULD FLING MOISTURE INTO COASTAL COUNTIES ESP SC.
HAVE RAISE FORECAST POPS SLIGHTLY IN DEFERENCE TO THIS SOLUTION
ESPECIALLY GIVEN THE SATELLITE PRESENTATION ACROSS THE UPSTREAM
PACIFIC OCEAN. BY SATURDAY THE MID LEVEL REPRESENTATION OF THE
TROUGH WILL BE A MERE SHEAR LINE AND LIKELY HAVE LITTLE EFFECT ON
THE FORECAST. SURFACE FLOW REMAINS VERY LIGHT DUE TO A POORLY
DEFINED PRESSURE PATTERN-BOTH NOT VERY CONDUCIVE OF RAINFALL.
SUNDAY AND MONDAY THIS FEATURE IS MAINTAINED DESPITE ITS WEAKNESS
AND IT DRIFTS WESTWARD. NORMAL THIS ALLOW FOR SOME DEEPER MOISTURE
TO ADVECT INTO THE CAROLINAS AS THEY FIND THEMSELVES DOWNSTREAM OF
THE TROUGH. MODELS ARE NOT TOO IMPRESSED WITH THE MOISTURE RETURN
AND POPS WILL BE CAPPED AT VERY LOW VALUES. TUESDAY APPEARS TO BE
THE DAY WHEN THE MOISTURE GROWS DEEP ENOUGH FOR POPS TO RISE ABOVE
THE SILENT 20/ISO VALUE.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...TEMPO SHRA/MVFR AND POSSIBLY VCTS WILL AFFECT
KFLO/KLBT MAINLY THIS AFTERNOON. BEST CONFIDENCE OF OCCURRENCE IS
AT KFLO. THE COASTAL TERMINALS WILL HAVE A BETTER CHANCE SHRA/MVFR
WITH TSRA/TEMPO IFR ESPECIALLY KCRE/KMYR DUE TO A PINNED SEA
BREEZE. WINDS WILL BE SW-SSW WITH GUSTS TO AROUND 20 KTS MAINLY AT
THE COASTAL TERMINALS. ACTIVITY SHOULD DISSIPATE TO ISOLATED
THUNDER SHOWERS EARLY EVENING BUT LOOKS LIKE TSRA COVERAGE MAY
INCREASE DURING THE MID TO LATE EVENING HRS AND POSSIBLY EXTEND
INTO THE PRE-DAWN WED HRS ACROSS THE COASTAL TERMS AS NEAR TERM
MODELS THINK UPSTREAM CONVECTION MAY HOLD TOGETHER AS IT DROPS TO
THE SE OVERNIGHT.
WINDS WILL SHIFT TO THE NW-N AT KLBT/KFLO OVERNIGHT INTO DAYLIGHT
WED...BUT REMAIN SW AT THE COASTAL TERMINALS INTO DAYLIGHT WED.
THERE IS A CHANCE OF MVFR ST/FOG IN THE EARLY MORNING HOURS
ACROSS KLBT. CONFIDENCE IS LOW ATTM. OTHERWISE...VFR 13Z-18Z WED.
EXTENDED OUTLOOK...VFR WITH ISOLATED SHOWERS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM TUESDAY...PREVIOUS WINDS UPDATE STILL AOK...AND WILL
CONTINUE TO ILLUSTRATE WINDS INCREASING TO 15 TO 20 KT BY EARLY
EVENING AND CONTINUING OVERNIGHT. HOWEVER...LATEST IN-HOUSE SWAN
MODEL RUN NOW INDICATES A FEW 5 FOOTERS POSSIBLE OVERNIGHT
ESPECIALLY OFF CAPE FEAR...AS PREVIOUSLY MENTIONED. AS A
RESULT...HAVE UPPED THE SIGNIFICANT SEAS TO A SOLID 4 FOOT FOR THE
WATERS FROM CAPE FEAR SOUTH TO LITTLE RIVER INLET...AND THE
PHRASEOLOGY OF 5 FOOTERS POSSIBLE ACROSS THE OUTERS OFF CAPE FEAR.
INITIALLY...THE ENE 1.5 FOOT LAZY GROUND SWELL WILL DOMINATE THE
SIG. SEAS SPECTRUM...ENERGY-WISE...BUT GIVE WAY TO THE 3 TO 5 SECOND
SW WIND DRIVEN CHOP LATER THIS EVENING AND OVERNIGHT. BOTH WINDS
AND SIG. SEAS COMBINED REMAIN JUST BELOW SCEC CONDITIONS. IF THE 5
FOOTERS BECOME MORE COMMON THAN WILL HAVE TO RE-VISIT THE ISSUANCE
OF A POSSIBLE SCEC.
PREVIOUS..........................................................
AS OF 130 PM TUESDAY...MODEL SFC PRESSURE PATTERN AND GRADIENT AHEAD
OF THE APPROACHING COLD FRONT CONTINUE TO ILLUSTRATE SW WINDS
INCREASING TO 15-20 KT BY LATE THIS AFTERNOON AND CONTINUING THRU
TONIGHT. SIGNIFICANT SEAS WILL RESPOND AND BUILD TO AROUND 3 FT LATE
THIS AFTERNOON...AND A SOLID 3 TO 4 FT TONIGHT. IF A SOLID 12 HRS OF
15-20 KT SW WINDS OCCUR...THE AREA WATERS WILL LIKELY SEE 5 FOOTERS
ESPECIALLY OFF CAPE FEAR. AT THIS POINT...HAVE NO RECEIVED A SEAS
UPDATE WITH THE LOCAL SWAN RUN AND THUS WILL HOLD OFF WITH THE 5
FOOTERS FOR NOW. CONVECTION MOVING OFF THE MAINLAND MAY BECOME MORE
COMMON LATER THIS EVENING AND OVERNIGHT.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 PM TUESDAY...COLD FRONT APPROACHING FROM THE WEST WILL
MOVE SLOWLY TOWARDS THE WATERS DURING WEDNESDAY...BEFORE STALLING
OFFSHORE THROUGH THURSDAY. WINDS EARLY WEDNESDAY WILL BE AROUND 15
KTS FROM THE SW AHEAD OF THE FRONT...BUT WILL THEN EASE AS THE FRONT
APPROACHES THANKS TO THE WEAKENING GRADIENT. WINDS REMAIN OUT OF THE
SW INTO TUESDAY NIGHT BEFORE THE FRONT CROSS THE WATERS...CREATING A
WIND SHIFT TO THE NORTH BY THURSDAY MORNING AT LESS THAN 10 KTS. AS
THIS FRONT SINKS SOUTHWARD AND STALLS THURSDAY...WINDS WILL VEER
FURTHER TO THE EAST MOST OF THE DAY...BUT AT STILL LIGHT SPEEDS
AROUND 10 KTS. HIGHEST SEAS THIS PERIOD WILL BE THE FIRST FEW HOURS
ON WEDNESDAY ON THE STRONGER SW WINDS...REACHING 3-5 FT...BEFORE
FALLING OFF TO 2-3 FT LATE WEDNESDAY AND THROUGH THE REMAINDER OF
THE PERIOD.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 PM TUESDAY... THERE WILL NOT BE MUCH OF A PRESSURE
GRADIENT IN PLACE FOR MOST OF IF NOT THE ENTIRE PERIOD. AS SUCH WE
ONLY EXPECT A LIGHT/LESS THAN 10 KT WIND FOR THE MOST PART BLOWING
ONSHORE LARGELY DRIVEN BY THE SEA BREEZE. IN THE ABSENCE OF ANY
SWELL OVER THE OCEAN DUE TO NO STRONG ESTABLISHED FETCHES LOCAL
SEAS WILL BE MINIMAL AND GENERALLY CAPPED AT 2 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...JDW
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...MBB
AVIATION...DCH/MRR
MARINE...DCH/JDW/MBB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
216 PM EDT TUE AUG 11 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TODAY AND MAY EXTEND INTO WEDNESDAY AS
A COLD FRONT MAKES ITS WAY THROUGH THE AREA. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT WEDNESDAY...OFFERING SEASONABLE AND
MAINLY DRY CONDITIONS INTO THE WEEKEND. A CHANCE OF RAIN MAY
RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND DIRECTS
MOISTURE ONSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM TUESDAY...HAVE TWEAKED THIS AFTN MAX TEMPS A DEGREE
OR 2 LOWER FOR BASICALLY THE ILM NC COUNTIES DUE TO THE EXTENDED
PERIOD OF OVERCAST SKIES. THE ILM SC COUNTIES ACTUALLY NEEDED A
DEGREE OR 2 ADJUSTMENTS HIER...MAINLY CLOSER TO THE IMMEDIATE
COAST DUE TO A SOMEWHAT PINNED SEA BREEZE DUE TO SW-WSW WINDS
25-35 KT IN THE LOWER LEVELS...SFC THRU 700MB. STILL THINK
CONVECTION WILL FIRE LATER THIS AFTN AND EVENING DUE TO THE DAYS
INSOLATION. LATEST HRRR AND WRF INDICATE THAT CONVECTION WILL
DEVELOP UPSTREAM CLOSER TO THE COLD FRONT LATE THIS AFTN...AND
MAKE A BEE-LINE TO THE ILM CWA LATER THIS EVENING AND INTO THE
PRE-DAWN WED HRS. AND ACTUALLY MAY INCREASE INTENSITY AND/OR
COVERAGE AS IT PUSHES TO THE COAST. WITH THAT ON THE TABLE
NOW...HAVE DECIDED TO KEEP THE GOOD CHANCE POPS ACROSS THE FA WELL
INTO THE NIGHT TIME HRS. HAVE BACKED OFF WITH THE COLD FRONTS
PROGRESSION TO THE COAST OVERNIGHT...AND BASICALLY NOW HAVE IT
REACHING THE I-95 CORRIDOR BY DAYBREAK WED. SOME RE-ADJUSTMENTS TO
MIN TEMPS HAVE NOW BEEN APPLIED TO ACCOUNT FOR THE COLD FRONTS
SLOWER PROGRESSION.
PREVIOUS.......................................................
AS OF 1000 AM TUESDAY...HAVE MODIFIED PCPN TYPE FOR THE REMAINDER
OF THIS MORNING AND AFTERNOON TO REFLECT ONGOING SPOTTY LIGHT RAIN
AND/OR SHOWERS VIA 88D RADAR TRENDS...AND INTRODUCING THUNDER BY
MIDDAY. HAVE TONED DOWN THE REMAINING MORNING POPS INTO THE AFTN
TO ACCOUNT FOR THE DELAY IN THE ATM DESTABILIZING DUE TO THE
WIDESPREAD CLOUDINESS AND SPOTTY LIGHT PCPN. STILL EXPECT CLOUDS
TO THIN ENOUGH FOR INSOLATION TO FINALLY AID DESTABILIZATION LATER
THIS AFTN AND EVENING. HAVE ALSO TWEAKED MAX TEMPS BY A DEGREE OR
2 TODAY...MAINLY LOWER TO ACCOUNT FOR THE OVERALL LOWER AMOUNT OF
INSOLATION MAKING IT TO THE SFC.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...COLD FRONT WILL BE MAKING ITS WAY OFF THE
COAST ON WEDNESDAY...BUT MAY GET HUNG UP RIGHT ALONG THE COAST
LONG ENOUGH TO PRODUCE SOME CONVECTION AS W-NW WINDS BEHIND FRONT
COME UP AGAINST ON SHORE SEA BREEZE FLOW. THEREFORE WILL KEEP SOME
POTENTIAL FOR SHWRS/TSTMS THROUGH WED AFTN MAINLY ALONG AND NEAR
THE COAST. PCP WATER VALUES DROP DOWN TO 1.5 INCHES THROUGH EARLY
WED AND CONTINUE TO FALL TO LESS THAN 1.25 INCHES BY LATE WED INTO
THURS. INLAND WILL SEE DRIER AIR COME EARLIER IN THE DAY WITH
VALUES DOWN TO 1.25 INCHES BY NOON. MID TO UPPER TROUGH WILL DIG
DOWN REMAINING ALIGNED DOWN THE EAST COAST WITH TROUGH AXIS
SHIFTING OFF THE COAST LEAVING A DEEPER DRIER NORTHERLY FLOW
ACROSS THE CAROLINAS THROUGH MID WEEK. OVERALL EXPECT CLEARING
SKIES THROUGH EARLY WED BUT RESIDUAL LOW LEVEL MOISTURE WILL
COMBINE WITH LOCALIZED CONVERGENCE TO PRODUCE SOME CLOUDS AND A
POSSIBLE SHWR/TSTM OR TWO ONCE SEA BREEZE KICKS UP CLOSER TO THE
COAST. DEWPOINT TEMPS WILL DROP OFF AS DRIER AIR FILTERS IN WITH
READINGS DOWN IN THE MID 60S BY WED AFTN INLAND. THIS DRIER AIR
WILL FILTER TOWARD THE COAST BY WED NIGHT. THE LESS HUMID AIR
WILL ALLOW FOR GREATER DIURNAL SWINGS AND EXPECT TEMPS TO RUN
SLIGHTLY BELOW NORMAL BY THURS...BUT TEMPS SHOULD RUN WARMER IN
DOWNSLOPE FLOW ON WED.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 330 AM TUESDAY...MID TO UPPER TROUGH CONTINUES TO HANG
DOWN THE EAST COAST WITH TROUGH AXIS FAR ENOUGH EAST TO KEEP BEST
LIFT AND MOISTURE OFF THE COAST THROUGH MUCH OF THE LATE WEEK
PERIOD. WEAK HIGH PRESSURE WILL KEEP LIGHT AND VARIABLE WINDS WITH
A GENERAL NORTHERLY COMPONENT TO THE FLOW. WITH SUCH LIGHT
PREVAILING WINDS AND PLENTY OF SUNSHINE...EXPECT SEA BREEZE TO
DRIVE THE WINDS EACH AFTERNOON. MODELS SHOW TROUGH ALOFT SHIFTING
BACK TO THE WEST ALLOWING FOR A DEEPER SOUTHERLY FLOW TO DEVELOP
LATE SUN INTO MONDAY. ALSO...SFC HIGH PRESSURE WILL SHIFT OFF THE
COAST BY LATE SUNDAY ALLOWING WINDS TO COME AROUND TO A MORE
SOUTHERLY DIRECTION...ALTHOUGH REMAINING LIGHT. THIS SHOULD BRING
AN INCREASING CHC OF CONVECTION BACK INTO THE FORECAST FOR LATE
SUNDAY INTO MONDAY. BUT OTHERWISE EXPECT CLEARING THROUGH EARLY
THURS AND THEN PLENTY OF SUNSHINE AND NEAR SEASONABLE TEMPS
THROUGH THE WEEKEND. WITH LESS HUMID AIR MASS IN PLACE...TEMPS
WILL HAVE GREATER DIURNAL SWINGS.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 18Z...TEMPO SHRA/MVFR AND POSSIBLY VCTS WILL AFFECT
KFLO/KLBT MAINLY THIS AFTERNOON. BEST CONFIDENCE OF OCCURRENCE IS
AT KFLO. THE COASTAL TERMINALS WILL HAVE A BETTER CHANCE SHRA/MVFR
WITH TSRA/TEMPO IFR ESPECIALLY KCRE/KMYR DUE TO A PINNED SEA
BREEZE. WINDS WILL BE SW-SSW WITH GUSTS TO AROUND 20 KTS MAINLY AT
THE COASTAL TERMINALS. ACTIVITY SHOULD DISSIPATE TO ISOLATED
THUNDER SHOWERSEARLY EVENING BUT LOOKS LIKE TSRA COVERAGE MAY
INCREASE DURING THE MID TO LATE EVENING HRS AND POSSIBLY EXTEND
INTO THE PRE-DAWN WED HRS ACROSS THE COASTAL TERMS AS NEAR TERM
MODELS THINK UPSTREAM CONVECTION MAY HOLD TOGETHER AS IT DROPS TO
THE SE OVERNIGHT.
WINDS WILL SHIFT TO THE NW-N AT KLBT/KFLO OVERNIGHT INTO DAYLIGHT
WED...BUT REMAIN SW AT THE COASTAL TERMINALS INTO DAYLIGHT WED.
THERE IS A CHANCE OF MVFR ST/FOG IN THE EARLY MORNING HOURS
ACROSS KLBT. CONFIDENCE IS LOW ATTM. OTHERWISE...VFR 13Z-18Z WED.
EXTENDED OUTLOOK...VFR WITH ISOLATED SHOWERS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM TUESDAY...MODEL SFC PRESSURE PATTERN AND
GRADIENT AHEAD OF THE APPROACHING COLD FRONT CONTINUE TO
ILLUSTRATE SW WINDS INCREASING TO 15-20 KT BY LATE THIS
AFTERNOON AND CONTINUING THRU TONIGHT. SIGNIFICANT SEAS WILL
RESPOND AND BUILD TO AROUND 3 FT LATE THIS AFTERNOON...AND A SOLID
3 TO 4 FT TONIGHT. IF A SOLID 12 HRS OF 15-20 KT SW WINDS
OCCUR...THE AREA WATERS WILL LIKELY SEE 5 FOOTERS ESPECIALLY OFF
CAPE FEAR. AT THIS POINT...HAVE NO RECEIVED A SEAS UPDATE WITH
THE LOCAL SWAN RUN AND THUS WILL HOLD OFF WITH THE 5 FOOTERS FOR
NOW. CONVECTION MOVING OFF THE MAINLAND MAY BECOME MORE COMMON
LATER THIS EVENING AND OVERNIGHT.
PREVIOUS.......................................................
AS OF 1015 AM TUESDAY...ATTM ONLY CHANGE WAS MADE TO THE POTENTIAL
PCPN MOVING ACROSS THE FA. THIS IS IN REGARD TO AREAL COVERAGE AND
OVERALL POPS LATE THIS MORNING THRU TONIGHT. EXPECT SEAS TO BUILD
TO 2 TO 4 FT...WITH THE 4 FOOTERS PRIMARILY OFF CAPE FEAR THIS
AFTN...PEAKING DURING THE PREDAWN WED HRS. WIND DRIVEN WAVES TO
DOMINATE SIG. SEAS WITH 3 TO 5 SECOND PERIODS. WILL HAVE TO TAKE
ANOTHER LOOK AT THE LATEST VARIOUS MODEL SFC PRESSURE FIELDS AND
GRADIENTS FOR TONIGHTS WINDS WHICH MAY BE SLIGHTLY UNDER-DONE.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 330 AM TUESDAY...COLD FRONT MAY GET HUNG UP RIGHT ALONG THE
COAST ON WED PRODUCING A MORE VARIABLE WIND FLOW...BUT AS SOON AS
ON SHORE SEA BREEZE SETTLES DOWN WED NIGHT...FRONT WILL GET A PUSH
OFF SHORE AS HIGH PRESSURE BUILDS DOWN BEHIND IT. OVERALL EXPECT
WINDS TO VEER AROUND TO THE W-NW EARLY WED AND THEN BECOME MORE
VARIABLE WED AFTN BEFORE INCREASING SLIGHTLY OUT OF THE N-NE
THURS NIGHT AS HIGH PRESSURE BUILDS IN. SEAS WILL SETTLE TO 2-3
FT WED AFTN AND EVENING AS WINDS LIGHTEN UP...BUT SHOULD RISE A
LITTLE THURS NIGHT INTO EARLY FRI AS HIGH BUILDS IN. A LONGER
PERIOD EASTERLY SWELL UP TO 9 SEC WILL MIX IN WITH GENERALLY LOW
END SHORTER PERIOD WINDS WAVES. SEAS MAY REACH BACK UP TO 4 FT
THURS NIGHT...MAINLY IN OUTER WATERS.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 330 AM TUESDAY...WEAK HIGH PRESSURE OVER THE SOUTHEAST WILL
BECOME MORE DIFFUSE LEAVING FAIRLY LIGHT PREVAILING WINDS. OVERALL
EXPECT NORTHERLY FLOW TO VEER AROUND BECOMING MORE EASTERLY AS
WEAK HIGH PRESSURE REMAINS STRETCHED ACROSS THE REGION WITH
CENTER TO THE NORTH. WINDS WILL REMAIN LESS THAN 15 KTS FOR THE
MOST PART. EXPECT SPIKE IN WINDS EACH AFTN DUE TO SEA BREEZE. A
LONGER PERIOD EASTERLY SWELL WILL BEGIN TO DOMINATE AS SHORTER
PERIOD WIND WAVES DIMINISH INTO THE WEEKEND.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RGZ
NEAR TERM...DCH/REK
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
138 PM EDT TUE AUG 11 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE UPPER PLAINS WILL GRADUALLY MOVE UP THE
OHIO VALLEY THROUGH THURSDAY. A WEAK COLD FRONT SHOULD MOVE
THROUGH THE REGION LATE FRIDAY THEN HIGH PRESSURE WILL REBUILD
OVER THE AREA FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN UPPER LEVEL TROUGH OVER THE AREA
WILL KEEP CONDITIONS UNSETTLED THRU TONIGHT. BREAKS IN CLOUDS WILL
OCCUR ESPECIALLY OVER THE WEST HALF OF THE AREA.
THE NEAR TERM...HIGH RES MODELS...ESPECIALLY THE HRRR INDICATE A
POTENTIAL FOR LIGHT SHRA TODAY OVER THE EAST 2/3 OF THE CWA. AN
UPPER S/W DROPPING INTO THE AREA TONIGHT WILL BRING AN ADDITIONAL
THREAT FOR LIGHT SHRA WITH EMPHASIS FOR THE SNOWBELT AS LAKE EFFECT
CONDITIONS BECOME A LITTLE MORE FAVORABLE.
TEMPS WILL BE COOLER TODAY AND TONIGHT AS WEAK COLD ADVECTION OCCURS.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
EARLY WEDNESDAY LAKE INDUCED RAIN SHOWERS COULD BECOME A BIT MORE
PERSISTENT IN RESPONSE TO THE LAST BIT OF ENERGY THAT WILL DROP OUT
OF THE MAIN TROF. THESE SHOWERS WILL PRIMARILY AFFECT PRIMARY AND
SECONDARY SNOWBELT COUNTIES. DECREASE POPS THROUGH THE REST OF THE
DAY AS THE HIGH BECOMES BETTER ESTABLISHED. EVEN THOUGH THE MODELS
SHOW PRECIP OVER THE LAKE MICHIGAN AREA LATE WEDNESDAY INTO
THURSDAY TRENDING ESE TOWARDS NORTHERN OHIO...KEPT THE FORECAST
DRY GIVEN LIMITED MOISTURE. A BETTER CHANCE FOR RAIN WILL COME
FRIDAY MORNING WITH A WEAK COLD FRONT THAT WILL LIKELY DISSIPATE
ACROSS NORTHERN OHIO. TEMPERATURES WILL RUN ABOUT 10 DEGREES BELOW
NORMAL ON WEDNESDAY THEN START TO MODERATE SOME ON THURSDAY AS WE
GET INTO SOME WEAK WAA.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A WEAKENING COLD FRONT SHOULD JUST ABOUT BE OUT OF THE
AREA AT THE START OF THE PERIOD. ALL OF THE GUIDANCE CONTINUES TO
SUGGEST THAT THERE COULD BE SOME RESIDUAL SHOWER ACTIVITY ON
SATURDAY IN THE WAKE OF THIS FRONT. HAVE ACTUALLY BUMPED UP PRECIP
CHANCES A LITTLE AS BOTH THE ECMWF AND GFS ARE NOW SHOWING PRECIP.
THE SECOND HALF OF THE WEEKEND WILL BE QUIET AS HIGH PRESSURE
BRIEFLY BUILDS OVER THE REGION. ANOTHER COLD FRONT WILL APPROACH
FROM THE NORTHWEST AT THE END OF THE PERIOD. ALREADY HAVE CHANCE
WORDING IN THE MONDAY FORECAST AND THAT SEEMS REASONABLE.
TEMPERATURES DURING THE PERIOD WILL AVERAGE A COUPLE OF DEGREES
ABOVE NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A FALL-LIKE PATTERN WITH A COOL NORTHWEST FLOW ACROSS LAKE ERIE.
HIGH PRESSURE TRYING TO BUILD IN FROM THE WEST BUT A WEAK TROUGH
OF LOW PRESSURE WILL DROP ACROSS THE LAKE TONIGHT AND WILL LIKELY
REESTABLISH MVFR CEILINGS ACROSS NORTHEAST OHIO AND NORTHWEST
PENNSYLVANIA. A SHOWER OR TWO POSSIBLE ESPECIALLY IN THE SNOWBELT
OF EXTREME NE OH/NW PA TONIGHT OR WED MORNING BUT NOT ENOUGH OF A
THREAT TO PUT INTO THE TAF FORECASTS. CEILINGS WILL IMPROVE TO VFR
ON WEDNESDAY WITH CLEARING FROM WEST TO EAST IN THE LATE
AFTERNOON/EVENING.
OUTLOOK...A CHANCE OF NON-VFR CONDITIONS FRIDAY NIGHT INTO
SATURDAY IN SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
LIGHT NORTHWEST TO NORTH WINDS WILL INCREASE TODAY.
EXPECT PEAK SUSTAINED WINDS TO BE ABOUT 15 KNOTS WHICH IS JUST BELOW
WHAT IS NEEDED FOR SMALL CRAFT CONDITIONS. DAY CREW WILL HAVE TO
KEEP ON EYE ON THINGS BUT WILL HOLD OFF ON HEADLINES FOR NOW.
NORTHERLY WINDS WILL CONTINUE THROUGH LATE WEDNESDAY AND THEN BECOME
SOUTHWESTERLY ON THURSDAY AS HIGH PRESSURE MOVES OFF TO THE
SOUTHEAST. MAINLY SOUTHWEST FLOW IS THEN EXPECTED TILL ANOTHER COLD
FRONT CROSSES THE LAKE ON SATURDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAYERS
NEAR TERM...MAYERS
SHORT TERM...ADAMS/MAYERS
LONG TERM...KUBINA
AVIATION...KOSARIK
MARINE...KUBINA
AREA FORECAST DISCUSSION
NWS MEDFORD OR
859 AM PDT TUE AUG 11 2015
.UPDATE...JUST MADE AN UPDATE TO REMOVE POPS FOR THIS MORNING AND
ADJUST SKY COVER TO CURRENT TRENDS. LATEST SATELLITE SHOWS AN
UPPER LOW OFF THE COAST ALONG 130W WITH A STREAM OF CLOUDS TO ITS
EAST STREAMING IN OVER OUR AREA. THERE IS SOME LIGHTNING OCCURRING
WITHIN THE CENTER OF THE LOW, BUT NOTHING MUCH ELSE AT THE MOMENT.
RADAR IS NOT SHOWING ANY PRECIPITATION, AND WITH CLOUD COVER, I
WOULDN`T EXPECT ANYTHING IN THE NEAR TERM.
THERE IS STILL A CHANCE FOR THUNDERSTORMS TO FORM OVER THE
MOUNTAINS THIS AFTERNOON AND EVENING. THERE IS MOISTURE AND
INSTABILITY AVAILABLE, BUT WE LACK MUCH OF A TRIGGER TO GET IT
GOING. FORECAST SOUNDINGS SHOW IT BECOMING COMPLETELY UNCAPPED
OVER THE MOUNTAINS THIS AFTERNOON, SO CONVECTION WILL LIKELY
OCCUR. HOWEVER, WE WILL HAVE AN INCREASING JET ALOFT (FORECAST TO
REACH AROUND 100 KT LATE THIS AFTERNOON) WHICH SHOULD LIMIT THE
VERTICAL EXTENT OF SAID CONVECTION. WE WILL KEEP THE CHANCE FOR
THUNDERSTORMS OVER THE MOUNTAINS (AND THE ASSOCIATED RED FLAG
WARNING), BUT THE CONFIDENCE IN THIS REMAINS LOW. -WRIGHT
&&
.PREV DISCUSSION... /ISSUED 625 AM PDT TUE AUG 11 2015/
DISCUSSION...A LARGE CUTOFF LOW IS MOVING SLOWLY NORTH TO SOUTH OVER
THE OREGON OFFSHORE WATERS. THIS LOW WILL DICTATE THE CWA`S
WEATHER FOR THE NEXT SEVERAL DAYS. THE ATMOSPHERE FOR MUCH OF THE
FORECAST AREA WILL TREND DRIER TODAY...AND THIS DRIER AIR IS NOTED
ON THE MORNING WATER VAPOR IMAGERY...MOVING SOUTH TO NORTH FROM
CENTRAL CALIFORNIA. THIS DRIER AIR IS TIMED TO ARRIVE IN SOUTHERN
OREGON LATE THIS AFTERNOON. FARTHER WEST...MORE MIDLEVEL MOISTURE
IS EVIDENT AND WILL STREAM INTO THE WESTERN QUARTER OF THE
FORECAST AREA TODAY.
WE FOCUSED THIS EVENING ON THUNDERSTORM CHANCES IN SOUTHERN OREGON
AND NORTHERN CALIFORNIA. FIRST...AREAS THAT ARE TOO STABLE AND/OR
TOO DRY FOR THUNDERSTORMS INCLUDE EASTERN
SISKIYOU...MODOC...LAKE...AND CENTRAL AND SOUTHERN KLAMATH COUNTIES.
HERE...GFS FORECAST 850MB COMPUTED LI VALUES ARE POSITIVE...AND
700MB TO 500MB MOISTURE IS LESS THAN 50 PERCENT. FARTHER NORTH AND
WEST...A BROAD AREA OF NEGATIVE LIFTED INDEX VALUES...GENERALLY MORE
MOISTURE...AND AN UPPER LEVEL DISTURBANCE MOVING FROM SOUTH TO
NORTH...ALL CONTRIBUTE TO MOSTLY ISOLATED THUNDERSTORMS TODAY. THE
TRICKY AREAS WERE THE CASCADES FROM CRATER LAKE NORTHWARD...A
CLIMATOLOGICAL FAVORITE FOR LIGHTNING...AND THE HIGH TERRAIN OF
JOSEPHINE...CURRY...AND EXTREME WESTERN SISKIYOU COUNTY.
FIRST...WE HAVE CONTINUED THE RED FLAG WARNING FOR AREAS ALONG AND
NORTH OF CRATER LAKE...AS MODELS CONTINUE TO PAINT A SWATH OF
MOISTURE AND INSTABILITY THAT SUPPORTS SCATTERED THUNDERSTORMS
THERE. ADDITIONALLY...SLIGHT UPSLOPE COMPONENT TO THE WINDS MAY
ASSIST IN FORMATION OF STORMS THERE.
FURTHER TO THE SOUTHWEST...AROUND THE KALMIOPSIS WILDERNESS...MODELS
DEPICT SIGNIFICANT INSTABILITY...MOISTURE...AND SHOW A TRIGGER IN
THE FORM OF A NARROW SHORTWAVE AHEAD OF THE CUTOFF LOW. WE THINK
THE ABUNDANT MOISTURE ALOFT WILL PREVENT OPTIMAL SURFACE HEATING
AND THEREFORE KEEP ANY THUNDERSTORMS TO ISOLATED COVERAGE. THIS IS
A PLACE WORTH MONITORING FOR HRRR TRENDS IN THE MORNING...TO
DETERMINE IF ANY PRODUCTS NEED TO BE ISSUED FOR THAT AREA.
THE LATEST ARW AND NMM HIGH-RES OUTPUT...AS WELL AS HRRR MODELED
REFLECTIVITIES SUPPORT THE CURRENT FORECAST THINKING THAT LACK OF
MOISTURE SHOULD PREVENT ABUNDANT LIGHTNING IN MOST PLACES. STORMS
TODAY SHOULD NOT PRODUCE MUCH PRECIPITATION...ESPECIALLY THE
FURTHER EAST ONE GOES. CLOSER TO THE COAST...PRECIPITABLE WATER IS
HIGHER AND RAIN IS EXPECTED WITH ANY SHOWERS OR STORMS THAT DO
FORM. STORM MOTION WILL BE FROM SOUTH-SOUTHEAST TO NORTH-NORTHWEST
AT ABOUT A 20KT CLIP TODAY.
TUESDAY NIGHT...THE LATEST NAM UPPER LEVEL INSTABILITY PARAMETERS
SUCH AS MODIFIED TOTAL TOTALS AND 700MB-500MB CAPE SHOW SOME
POTENTIAL FOR THUNDERSTORMS FOR NORTHERN DOUGLAS COUNTY TOWARDS THE
COAST...AND THIS BEARS WATCHING FOR FUTURE TRENDS. EARLIER MODELS
SHOWED LESS FAVORABLE CONDITIONS...SO SHOWERS ARE IN THE CURRENT
FORECAST FOR TUESDAY NIGHT.
ON WEDNESDAY...THE UPPER LOW DRIFTS FARTHER TO THE SOUTH...AWAY FROM
THE AREA...AND DRAWS IN EVEN DRIER AIR...HELPING TO WARM THINGS UP
AND PREVENT ANY THUNDERSTORMS FROM FORMING. THERE WAS ENOUGH
INDICATION OF SHOWERS IN PORTIONS OF THE WEST SIDE TO KEEP THEM
IN THE FORECAST...BUT FUTURE SHIFTS MAY BE ABLE TO REMOVE THEM
ALTOGETHER FOR A DRY WEDNESDAY.
ALL MODELS AGREE ON THE LOW MOVING BACK TOWARDS THE COAST
THURSDAY...BUT THE SPEED OF MOVEMENT DIFFERS. THE CURRENT THINKING
IS THAT ENOUGH MOISTURE AND DYNAMICS ARRIVE ON THURSDAY TO BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS TO THE AREA. HOWEVER...EVEN ONLY
A FEW DAYS AWAY...CONFIDENCE IN THIS PORTION OF THE FORECAST IS LOW
AS THE EC KEEPS THE LOW FURTHER WEST AND THUS DIMINISHES THE CHANCE
FOR SHOWERS ON THURSDAY...AND DELAYS ANY RAIN CHANCES UNTIL
THURSDAY EVENING.
ONCE THE LOW PASSES...STABLE CONDITIONS ARE EXPECTED FRIDAY INTO THE
WEEKEND WITH WESTERLY TO SOUTHWESTERLY FLOW ALOFT.
AVIATION...FOR THE 11/12Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL PERSIST THROUGH MID-MORNING (CLEARING AROUND 16-
18Z) EXCEPT FOR SOME LINGERING LOW CIGS POSSIBLE NEAR KBOK INTO THE
AFTERNOON. IFR CIGS ARE EXPECTED TO RETURN TO THE COAST THIS
EVENING AROUND 04Z. INLAND...VFR CONDITIONS WILL PREVAIL THROUGH
THIS MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN SMOKE. A FEW
THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING WEST OF THE CASCADES,
MAINLY NEAR THE COAST. SOUTHEAST STEERING WINDS ARE EXPECTED WITH
ISOLATED THUNDERSTORMS THIS AFTERNOON AND EVENING FROM THE SOUTHERN
OREGON CASCADES INTO EASTERN DOUGLAS COUNTY AND FROM WESTERN
SISKIYOU COUNTY INTO JOSEPHINE AND CURRY COUNTIES. STORMS MAY BRING
ERRATIC AND GUSTY WINDS AND LOCAL OBSCURATION OF HIGHER TERRAIN. -CC
MARINE...UPDATED 245 AM PDT TUESDAY 11 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL RESULT IN LIGHT WINDS AND LOW SEAS OVER THE
NEXT FEW DAYS. ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD BRING A FEW
THUNDERSTORMS TO THE COASTAL WATERS THIS MORNING AND OCCASIONAL
SHOWERS THROUGH THURSDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS, ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
ALTHOUGH STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY
STEEP SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -CC
FIRE WEATHER...UPDATED 600 AM PDT TUESDAY 11 AUGUST 2015...A SLIGHT
CHANCE OF THUNDERSTORMS AND SHOWERS IS POSSIBLE WEST OF THE CASCADES
THIS MORNING, MAINLY NEAR THE COAST. THEN MODELS SHOW SOME MID LEVEL
MOISTURE, INSTABILITY, AND DISTURBANCES ALOFT MOVING INTO THE AREA
THIS AFTERNOON AND EVENING. THIS IS EXPECTED TO BRING MAINLY
ISOLATED STORMS TO AREAS FROM THE CASCADES WEST AND INTO NORTHERN
KLAMATH COUNTY, EXCEPT FOR SCATTERED THUNDERSTORMS WHICH ARE
EXPECTED IN EASTERN PORTIONS OF FIRE WEATHER ZONE 617 AND FAR
NORTHERN PORTIONS OF FIRE WEATHER ZONE 623 LATE THIS AFTERNOON AND
THIS EVENING. OVERALL THERE IS MODERATE CONFIDENCE FOR SCATTERED
STORMS IN THESE AREAS LATE TODAY AND THIS EVENING. OF NOTE, MODELS
ARE TRACKING THIS MORNING`S STORMS WELL COMPARED TO YESTERDAYS
EVENT. MODELS SHOW GOOD INSTABILITY AND UPPER LEVEL SUPPORT FOR
STORMS IN ZONES 617 AND NORTHERN 623. UNCERTAINTY IS MAINLY WITH THE
TRACK OF ANY DISTURBANCES INTO THE AREA AND WHETHER THEY PUSH
FURTHER NORTH. FOR AREAS WEST OF THE CASCADES, THE BEST CHANCE FOR
ISOLATED STORMS TO DEVELOP THIS AFTERNOON INTO THIS EVENING IS IN
WESTERN SISKIYOU COUNTY NORTHWARD INTO WESTERN JOSEPHINE AND EASTERN
CURRY COUNTIES. ALSO THE STORMS THAT DEVELOP IN THE OREGON CASCADES
MAY MOVE EAST-NORTHEAST AND INTO NORTHERN JACKSON AND CENTRAL
DOUGLAS COUNTY DURING THE EVENING.
ON WEDNESDAY, CONDITIONS ARE FORECAST TO BE MORE STABLE AND LESS
FAVORABLE FOR THUNDERSTORMS. THEN AS THE UPPER LOW NEARS THE COAST
ON THURSDAY, GRADUALLY MOVING ONSHORE THURSDAY EVENING AND NIGHT,
EXPECT INCREASED CHANCES FOR A MIX OF SHOWERS AND THUNDERSTORMS OVER
THE AREA. HOWEVER, MODELS ARE SHOWING CONSIDERABLE VARIABILITY ON
THE TRACK OF THE LOW AND HOW QUICKLY IT WILL PUSH INLAND. SO
CONFIDENCE IS LOWER ON THE DETAILS OF THE FORECAST FOR THURSDAY.
AS THE UPPER LOW REMAINS OFF THE COAST, GUSTY SOUTH WINDS WILL
CONTINUE OVER EASTERN PORTIONS OF THE AREA THROUGH THURSDAY...WHEN
IT MAY BE ESPECIALLY WINDY ON THE EAST OF THE CASCADES AS THE UPPER
LOW GRADUALLY MOVES ONSHORE. ALSO GUSTY SOUTH WINDS ARE ALSO LIKELY
IN THE SHASTA VALLEY TODAY AND AGAIN ON WEDNESDAY AND POSSIBLY INTO
THURSDAY AFTERNOON. DAYTIME RELATIVE HUMIDITIES WILL INCREASE
SLIGHTLY ON THURSDAY.
AFTER THE TROUGH MOVES INLAND...OFFSHORE LOW LEVEL FLOW WILL DEVELOP
OVER THE COAST RANGE FRIDAY NIGHT INTO SATURDAY NIGHT. THIS MAY
BRING MODERATE RECOVERIES WITH LOCALLY POOR RECOVERIES POSSIBLE FOR
THE RIDGES, ESPECIALLY FOR THOSE IN THE COASTAL RANGES, SISKIYOUS
AND FOR THE MOUNTAINS IN WESTERN SISKIYOU COUNTY. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 5 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 PM PDT THIS
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
241 PM CDT TUE AUG 11 2015
.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...MAIN ISSUE IS THE
CHANCE FOR RAIN...WHICH IS NOT STRAIGHT-FORWARD SINCE MESO-SCALE
INFLUENCES WILL PLAY SOME ROLE IN HOW FAR SOUTH AND WEST CONVECTION
GOES (AND HOW MUCH AREA GETS). MOST MODELS KEEP AT LEAST A BIT OF A
CAP/CIN BUT IT GETS CLOSE TO BREAKING AND ANY STORM WHICH BREAKS THE
CAP (GIVEN DAYTIME TEMPERATURES) COULD INITIATE MORE CONVECTION VIA
COOLING AND/OR CONVERGENCE.
FOR TONIGHT...THINK ANY CONVECTION WHICH DEVELOPS NORTH OF THE CWFA
WILL REMAIN NORTH (THIS AGREES WITH THE LATEST HRRR AND TTU SMALL
SCALE MODELS...AND TO A LESSER DEGREE THE MSSL MODEL RUN AT 11/00Z).
FOR WEDNESDAY...MOISTURE GETS BETTER AND CONVERGENCE ALONG THE
BOUNDARY (MAINLY NORTH) COULD TRIGGER CONVECTION WHICH COULD MOVE
INTO THE CWFA IN THE AFTEROOON AND EVENING BEFORE ENDING. THUS...
WILL MAINTAIN THE HIGHER POPS TO THE NORTH/NORTHEAST WEDNESDAY AND
NEAR THE COAST WEDNESDAY NIGHT...BUT WILL MENTION AT LEAST A SLIGHT
CHANCE FOR RAIN ALL LOCATIONS WEDNESDAY AFTERNOON AND WEDNESDAY
EVENING.
OTHER THAN THAT...STILL LOOKS LIKE A HOT DAY ON WEDNESDAY WITH
BOUNDARY/FRONT TO THE NORTH. HAVE GONE ON THE WARM SIDE OF GUIDANCE
FOR TEMPERATURES ON WEDNESDAY. CONCERNING LOWS...A BIT TRICKER AS
MOST MODEL 2 METER TEMPERATURES ARE QUITE WARM BUT ALSO SHOWING
LIGHT SOUTHWEST WINDS AND ABOUT THE SAME IF NOT COOLER BOUNDARY
LAYER TEMPERATURES. AM GOING WITH MORE OF A CONSENSUS FORECAST (BUT
A TAD WARMER THAN THIS MORNING DUE TO AFOREMENTIONED TEMPERATURES)
FOR WEDNESDAY`S LOW TEMPERATURES...AND EVEN A BIT WARMER WEDNESDAY
NIGHT/THURSDAY MORNING. OBVIOUSLY ANY CONVECTION OVERNIGHT (WHICH IS
NOT EXPECTED TO BE MORE THAN ISOLATED AND MAINLY IN THE EVENING)
COULD LOWER TEMPERATURES MORE THAN EXPECTED. FINALLY...GENERALLY
LIGHT WINDS AND MORE CLOUDS ON WEDNESDAY THAN TODAY.
$$
.MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...A WEAK GRADIENT WILL
PERSIST WITH FRONT/BOUNDARY TO THE NORTH. WINDS WILL HAVE TROUBLE
MAKING IT BEYOND 10-12 KNOTS THROUGH THE PERIOD...MAYBE WEDNESDAY
NIGHT. MAINLY A SLIGHT CHANCE FOR SHOWERS/STORMS WEDNESDAY AND
WEDNESDAY NIGHT...BUT DID GO A BIT HIGHER OVER THE NORTHEAST
PROXIMATE TO BETTER FORCING AND LIMITED CAP.
&&
.LONG TERM (THURSDAY THROUGH TUESDAY)...EXTENDED BEGINS WITH UPPER
RIDGE AXIS STILL FAR ENOUGH WEST TO LIMIT CONVECTIVE CAP AND
MAINTAIN RAIN CHANCES ACROSS THE COASTAL BEND. RIDGE AXIS THEN
WOBBLES EASTWARD THROUGH THE WEEKEND...RESULTING IN DRY AND WARM
WEATHER.
BY MONDAY MODELS PROJECT THE NEXT IMPULSE REACHING THE GREAT LAKES
TO EXTEND SOUTHWEST DOWN UNDER THE BULK OF THE RIDGE...COOLING
TEMPERATURES ALOFT. IF THIS PANS OUT...IT WILL HAVE THE DOUBLE
EFFECT OF REINTRODUCING LOW POPS AND COOLING TEMPERATURES BY FIVE OR
SO DEGREES.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEKEND...WITH
ELEVATED HEAT INDICES AS WELL. HIGHS MAY RELAX A BIT TOWARD THE END
OF THE PERIOD...WITH READINGS CLOSER TO NORMAL FOR MID AUGUST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 99 77 96 77 / 10 20 20 30 10
VICTORIA 75 101 76 98 76 / 10 30 30 30 10
LAREDO 77 103 80 104 80 / 10 10 20 20 10
ALICE 75 102 76 100 76 / 10 20 20 30 10
ROCKPORT 78 96 79 93 80 / 10 30 30 30 10
COTULLA 76 104 79 103 78 / 10 20 20 20 10
KINGSVILLE 76 101 76 98 76 / 10 20 20 30 10
NAVY CORPUS 79 94 80 91 80 / 10 20 20 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
JV/71...LONG TERM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO THE SOUTHERN GREAT PLAINS
EARLY THIS AFTERNOON. DIURNAL CU POPPED BY 15-16Z AND SPREAD SOUTH
TO COVER SCT-BKN CONDITIONS ACROSS MUCH OF THE STATE. A SHORTWAVE
CURRENTLY OVER WESTERN LAKE SUPERIOR WILL MOVE ACROSS NORTHEAST
WISCONSIN LATE IN THE DAY AND MAY PROLONG SCT CLOUD COVER INTO THIS
EVENING. OTHERWISE...THE MAIN FOCUS INCLUDES THUNDERSTORM POTENTIAL
FROM MID-LEVEL WARM ADVECTION FOR WEDNESDAY. SCATTERED
THUNDERSTORMS OCCURRED EARLIER TODAY OVER THE LAKE WINNIPEG REGION
IN THIS WARM ADVECTION ZONE.
TONIGHT...HIGH PRESSURE WILL SLIDING SOUTHEAST ACROSS THE WESTERN
GREAT LAKES WHILE A SHORTWAVE EXITS NORTHEAST WISCONSIN DURING THE
EVENING. THE SHORTWAVE MAY PROLONG SCT CLOUD COVER ACROSS EASTERN
WISCONSIN INTO MID-EVENING...BUT THE REST OF THE AREA SHOULD SEE
CLEARING SKIES WITH LOSS OF DAYTIME HEATING. ONCE THE CLOUDS
DISSIPATE...WILL SEE A PERIOD OF CLEAR CONDITIONS UNTIL LATE IN THE
NIGHT WHEN WARM ADVECTION CLOUDS MOVE SOUTHEAST INTO NORTH-CENTRAL
WISCONSIN. WITH CLOUDS ARRIVING LATE...DO NOT THINK FOG WILL BECOME
TOO BIG OF AN ISSUE. LOWS MAINLY IN THE LOWER TO MIDDLE 50S.
WEDNESDAY...WARM ADVECTION WILL CONTINUE ACROSS THE REGION. THE
BAND OF ASSOCIATED MID-CLOUDS WILL PROCEED EAST ACROSS THE FORECAST
AREA DURING THE MORNING AND THEN EXIT NORTHEAST WI AROUND MID-
AFTERNOON. SOME ELEVATED INSTABILITY GRAZES NORTHERN WISCONSIN
DURING THIS TIME...ALONG WITH MID-LEVEL FGEN ON THE NOSE OF A LLJ.
THOUGH MOISTURE IS NOT PLENTIFUL...NOT COMFORTABLE GOING DRY IN THIS
SCENARIO. SO WILL SHOW 20-30 PCT CHANCE OF RAIN ACROSS FAR N-C AND
PARTS OF NORTHEAST WI. THE REST OF THE AREA SHOULD SEE A PERIOD A
PARTLY/MOSTLY CLOUDY SKIES. HIGHS WARMING A COUPLE DEGREES...WITH
READINGS RANGING FROM THE UPPER 70S TO MID 80S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
WITH AMPLIFICATION OF THE WESTERN RIDGE EXPECTED THE REST OF THIS
WEEK...OUR AREA WILL CONTINUE TO FALL UNDER NORTHWEST FLOW.
DESPITE THAT...ABOVE NORMAL HEIGHTS AND WARM AIR ADVECTION FROM
THE WEST SHOULD KEEP TEMPERATURES ABOVE NORMAL...PERHAPS EVEN
SIGNIFICANTLY SO.
THE MAJOR FORECAST CHALLENGE REMAINS PRECIPITATION CHANCES FROM
WEDNESDAY NIGHT THROUGH THE WEEKEND. THOUGH THE GENERAL IDEA OF
MULTIPLE WEAK SHORTWAVE TROUGHS AND AT TIMES ASSOCIATED FRONTS
REMAINS SOLID...THE EXACT DETAILS REMAIN A BIT MUDDY. WEDNESDAY
NIGHT SEEMS PARTICULARLY CHALLENGING AS MANY INGREDIENTS ARE
PRESENT...BUT IN A DISJOINTED MANNER THAT DON`T ENTIRELY SUGGEST
STRONG POTENTIAL FOR CONVECTION. A THETA-E GRADIENT NOSES THROUGH
THE REGION EARLIER IN THE DAY...AND A MIDLEVEL VORT MAX SWINGS
THROUGH IN THE EVENING ALONG WITH MODEST INSTABILITY AND SHEAR BUT
LACKING ANY SIGNIFICANT TRIGGERING MECHANISM. IN THE OVERNIGHT
HOURS TOWARDS DAYBREAK...COULD BEGIN TO SEE INFLUENCE FROM AN
APPROACHING COLD FRONT. THOUGH I GET THE FEELING THAT THE EVENING
WILL END UP DRY...CAN`T RULE DEVELOPMENT OUT AND SO SOME LOW-END
POPS REMAIN. POPS THEN BEGIN TO INCREASE TOWARDS MORNING AS THE
FRONT DRAWS NEARER IN DEFERENCE TO THE MORE PROGRESSIVE ELEMENTS
OF THE MODEL ENVELOPE.
THURSDAY PERHAPS SHOWS THE BEST POTENTIAL FOR STORMS AS THE FRONT
SWINGS INTO THE AREA ALONG WITH BETTER INSTABILITY. INDEED...THE
GFS SUGGESTS UP TO 3000 J/KG OF CAPE IN THE NORTHWOODS LATE
THURSDAY AFTERNOON INTO THE EVENING AND MARGINAL 30 KNOT SHEAR.
FORECAST SOUNDINGS AGAIN SHOW CAPPING THURSDAY WHICH COULD BE
RESTRICTIVE...BUT THE FRONT SHOULD AID IN OVERCOMING THAT...AS
LONG AS IT MOVES IN QUICKLY ENOUGH. STEEP TEMPERATURE-DEWPOINT
SPREADS AT THE SURFACE AND A STRONGLY MIXED BOUNDARY LAYER CREATE
THE POTENTIAL FOR INVERTED-V TYPE SOUNDINGS. IF CONVECTION BECOMES
STRONG ENOUGH...THERE COULD BE SOME GUSTY WINDS TO BE FOUND.
GUIDANCE DOES BEGIN TO DIVERGE BUT...EITHER DUE TO SLOWER TIMING
IN SOME MODELS...AND STALLING THE FRONT OUT OVER SOUTHERN
WISCONSIN IN OTHERS...THE CHANCE FOR LINGERING RAIN DRAGS INTO
FRIDAY IN CENTRAL AND EAST CENTRAL WISCONSIN.
WE SHOULD THEN SEE A DRYING TREND THROUGH MOST OF THE WEEKEND AS
RIDING BUILDS INTO THE REGION AND TEMPERATURES ONLY A BIT COOLER
BEHIND THE WEAK FRONT. FINALLY...THE MIDLEVEL RIDGE WILL BEGIN TO
FLATTEN AS AN UPPER TROUGH SWINGS THROUGH CANADA. THE COLD FRONT
ASSOCIATED WITH ITS SURFACE REFLECTION LOOKS TO COME THROUGH THE
AREA SUNDAY NIGHT...BRINGING OUR NEXT CHANCE OF RAIN AND
POTENTIALLY TEMPERATURES NEAR SEASONAL AVERAGES FOR THE FIRST PART
OF NEXT WEEK.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1159 AM CDT TUE AUG 11 2015
CLOUDS WILL CONTINUE TO BUILD EARLY THIS AFTERNOON BUT
REMAIN VFR. WITH LOSS OF HEATING...WILL SEE CLEARING SKIES EARLY
THIS EVENING...WHICH SHOULD LEAD TO A TRANQUIL NIGHT. WARMER AIR
WILL BE INCOMING FROM THE NORTHWEST LATE TONIGHT INTO WEDNESDAY
MORNING. THE IMPACT FROM THIS WILL BE INCREASING MID-LEVEL CLOUDS
AND A SMALL CHANCE OF SHOWERS AND STORMS ACROSS FAR NORTHERN
WISCONSIN. A VERY LOW PROBABILITY THAT ANY STORMS WILL AFFECT
RHINELANDER.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
240 PM CDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 240 PM CDT TUE AUG 11 2015
MUCH OF THE PERIOD LOOKS TO BE QUIET AS HIGH PRESSURE DOMINATES
THE REGION. THIS HIGH IS CURRENTLY CENTERED OVER NEBRASKA WITH THE
RIDGE AXIS EXTENDING NORTH WELL INTO ONTARIO. THE HIGH IS EXPECTED
TO DRIFT EAST TONIGHT AND BE OVER THE AREA SETTING UP THE
POSSIBILITY OF VALLEY FOG. THE 11.12Z NAM FORECAST SOUNDING FOR
KLSE LATE TONIGHT HAS LIGHT WINDS OF 10 KNOTS OR LESS ONLY UP
THROUGH ABOUT 3000 FEET AND WHILE IT SHOWS SATURATION OCCURRING AT
THE SURFACE...IT IMMEDIATELY BECOMES VERY DRY JUST ABOVE THE
SURFACE. THE 11.17Z RAP FORECAST SOUNDING IS EVEN MORE PESSIMISTIC
AS IT DOES NOT SHOW SATURATION OCCURRING AT THE SURFACE AND HAS A
3C TEMP/DEW POINT SPREAD AT 12.11Z. FOR NOW...WILL LEAVE THE
MENTION OF PATCHY VALLEY FOG IN THE FORECAST IN CASE THE NAM
SOUNDING ENDS UP BEING MORE CORRECT BUT WOULD TEND TO THE THINK
WITH THE LACK OF A DEEPER LAYER OF LIGHT WINDS AND SATURATION THAT
THERE WILL BE VERY LITTLE FOG IN THE VALLEYS.
ALL THE 11.12Z MODELS HAVE TRENDED TOWARD KEEPING THE SURFACE
RIDGE OVER THE REGION LONGER THAN PREVIOUS MODEL RUNS. THE UPPER
LEVEL RIDGE AXIS REMAINS OVER THE EASTERN ROCKIES INTO THE
NORTHERN HIGH PLAINS WHICH ENDS UP PUSHING THE SYSTEM CROSSING
CANADA FARTHER TO THE NORTH. THE MODELS CONTINUE TO SHOW A WEAK
SHORT WAVE TROUGH UNDERNEATH THE MAIN SYSTEM BUT THIS SHOULD NOW
PASS EVEN FARTHER TO THE NORTHEAST AND OVER THE NORTHERN GREAT
LAKES FOR WEDNESDAY NIGHT INTO THURSDAY. WITH THE STRONGER LOW
LEVEL RIDGING...THE WEAK COLD FRONT HAS A HARD TIME WORKING SOUTH
AND ALL THE MODELS NOW SHOW THIS REMAINING TO THE NORTH OF THE
AREA WEDNESDAY NIGHT. WITH THE LACK OF SIGNIFICANT FORCING AND THE
FRONT STAYING TO THE NORTH...HAVE REMOVED THE RAIN CHANCES FOR
WEDNESDAY NIGHT.
THERE IS STILL A TREND FOR THE UPPER LEVEL HEIGHTS TO LOWER SOME
THURSDAY INTO THURSDAY NIGHT AS THE UPPER LEVEL RIDGE SHIFTS
SLIGHTLY TO THE WEST. THIS MAY ALLOW A SHORT WAVE TROUGH TO TOP
THE RIDGE AXIS AND THEN SLIDE SOUTHEAST ACROSS THE REGION. IF THE
11.12Z GFS IS CORRECT...THIS WAVE COULD PRODUCE SOME MODERATE PV
ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION.
WHAT LOW LEVEL MOISTURE TRANSPORT THERE IS LOOKS TO WRAP AROUND
THE LOW LEVEL RIDGE AND ACTUALLY COME BACK INTO THE AREA FROM THE
NORTHWEST. OVERALL...THE SIGNAL LOOKS PRETTY WEAK FOR RAIN AS THE
FRONT TRIES TO PUSH INTO THE REGION AND BOTH THE NAM AND 11.12Z
ECMWF KEEP THE AREA DRY WITH ANY RAIN OFF TO THE EAST. THE GFS
CONTINUES TO BE THE MOST ROBUST WITH RAIN AND WILL HONOR ITS
SOLUTION WITH SOME 20 TO 30 PERCENT RAIN CHANCES.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 240 PM CDT TUE AUG 11 2015
THERE COULD BE SOME LINGERING RAIN CHANCES ACROSS THE EAST INTO
FRIDAY FROM THIS SYSTEM...OTHERWISE IT LOOKS TO BE DRY THROUGH
SATURDAY NIGHT. THE RIDGE AXIS IS THEN EXPECTED TO GET FLATTENED
WITH A NEARLY ZONAL FLOW OVER THE UPPER MIDWEST AS A POSITIVE TILT
SYSTEM MOVES ACROSS SOUTHERN CANADA. THE CONCERN WITH THIS SYSTEM
IS HOW FAR SOUTH WILL THE TAIL OF THE SHORT WAVE TROUGH EXTEND.
THE GFS AND 11.12Z GEM ESSENTIALLY SHOW THIS SYSTEM STAYING WELL
TO THE NORTH WHILE THE ECMWF IS STRONGER WITH THE TAIL END OF THE
SYSTEM AND BRINGS A DECENT SECONDARY SHORT WAVE TROUGH ACROSS
SUNDAY AND SUNDAY NIGHT. A COLD FRONT SHOULD GET PUSHED INTO THE
AREA WITH THIS SYSTEM AND ALL THE MODELS AT LEAST SHOW SOME RAIN
CHANCES WITH THE FRONT WITH THE ECMWF HAVING THE MOST AND FOR NOW
WILL SHOW SOME 30 TO 40 PERCENT CHANCES SUNDAY AND SUNDAY NIGHT.
THE ECMWF PUSHES THE FRONT COMPLETELY THROUGH THE AREA WITH HIGH
PRESSURE BUILDING IN FOR THE START OF NEXT WEEK. HOWEVER...THE GFS
HANGS THE FRONT UP OVER THE AREA AND WOULD SUGGEST THERE WOULD BE
SOME ADDITIONAL RAIN CHANCES MONDAY INTO TUESDAY. WITH THE
UNCERTAINTY ON THAT SECONDARY SHORT WAVE TROUGH...WILL HONOR THE
GFS SOLUTION WITH SOME RAIN CHANCES FOR MONDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1152 AM CDT TUE AUG 11 2015
PRIMARY AVIATION CONCERN IS POTENTIAL FOR FOG BY WEDNESDAY
MORNING. SURFACE RIDGE WILL BE RIGHT OVERHEAD WITH A COOL AIRMASS
IN PLACE. LOOKING AT BOUNDARY LAYER PROFILES VIA BUFKIT...WOULD
LIKE TO SEE A DEEPER LAYER OF LIGHT WINDS. BUT MODELS ALL SHOWING
THAT THE WINDS PICK UP ABOVE 10 KTS ALREADY BY 2-3 KFT. THIS
MIXING TYPICALLY PRECLUDES DEVELOPMENT OF FOG. LOOKING AT WHAT
OCCURRED UNDER THE RIDGE THIS MORNING...FEEL THERE IS THE
POTENTIAL FOR AT LEAST SOME FOG. SO DID MAINTAIN THE 5SM BR FOR
KRST. AT KLSE...DO NOT FEEL THE WIDESPREAD VALLEY FOG WILL REACH
THE AIRPORT EN MASSE. BUT THERE IS POTENTIAL...ESPECIALLY IF THE
LIGHT WIND LAYER ENDS UP BEING DEEPER THAN CURRENTLY DEPICTED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...MW
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
452 PM MDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 237 PM MDT TUE AUG 11 2015
TONIGHT:
LATEST RADAR LOOP WAS SHOWING VERY MINIMAL COVERAGE IN SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE BULK OF THEM DEVELOPING OVER
THE LARAMIE RANGE. WOULD EXPECT THIS TREND TO CONTINUE DURING THE
REMAINDER OF THE AFTERNOON. ANOTHER CONCERN IS THE POTENTIAL FOR
PATCHY FOG DEVELOPMENT IN THE SOUTHERN PANHANDLE TONIGHT. LATEST
SURFACE ANALYSIS WAS SHOWING A GOOD FETCH OF LOW LEVEL MOISTURE
BETWEEN THE SURFACE HIGH IN THE PLAINS AND THE LEE TROF EAST OF
THE LARAMIE RANGE. THE NAM BUFKIT ANALYSIS WAS SHOWING THE
BOUNDARY LAYER RH FIELDS INCREASING AFTER MIDNIGHT IN THE SOUTHERN
PANHANDLE UNDERNEATH THE LOW LEVEL INVERSION. WE WENT AHEAD AND
INTRODUCED PATCHY FOG IN THIS REGION TO REFLECT THIS POTENTIAL.
WEDNESDAY-WEDNESDAY NIGHT:
A WEAK POTENTIAL VORTICITY ANOMALY IS EXPECTED TO MOVE INTO THE
SOUTHWEST PORTION OF THE FORECAST AREA ON WEDNESDAY MORNING WITH
THIS WAVE SPREADING WEST TO EAST DURING THE COURSE OF THE DAY.
IN ADDITION...THERE IS DECENT MOISTURE TRANSPORT AROUND 310K WITH
THE BEST LIFT IN THE NORTHERN HALF OF THE AREA. ANY CONVECTION
THAT DOES DEVELOP OVER THE LARAMIE RANGE EARLY WEDNESDAY AFTERNOON
SHOULD GENERALLY SPREAD EAST-NORTHEAST DURING THE COURSE OF THE
DAY. THE BEST INSTABILITY EXISTS OVER THE PANHANDLE...BUT THE
SHEAR IS QUITE LIMITED SO NOT EXPECTING ANYTHING SEVERE. THE
CONVECTION SHOULD BEGIN TO DIMINISH THE EVENING AND OVERNIGHT DUE
TO LIMITED SHEAR.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 237 PM MDT TUE AUG 11 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 450 PM MDT TUE AUG 11 2015
GOING TO CONTINUE CHANCES FOR IFR/LIFR CONDITIONS AT KCYS...KBFF
AND KSNY TONIGHT WITH SOUTHEAST WINDS CONTINUING. SUPPORTED BY
LATEST SREF AND HRRR FORECASTS AS WELL. COULD LAST ALL MORNING IF
THERE IS NO CONVECTION TO BREAK UP THE LOW LEVEL MOISTURE. WILL
TRY TO NAIL DOWN TIMING A LITTLE BETTER WITH THE 06Z TAF SUITE.
&&
.FIRE WEATHER...
ISSUED AT 237 PM MDT TUE AUG 11 2015
ONLY FIRE WEATHER CONCERN WILL BE THE LIGHTNING POTENTIAL OVER
THE MOUNTAINS DURING THE NEXT COUPLE OF DAYS WHICH COULD IGNITE A
FIRE START. OTHERWISE...RELATIVE HUMIDITIES WILL BE MARGINAL 20
TO 30 PERCENT WITH WIND SPEEDS POSSIBLY REACHING 20 TO 25 MPH IN
AREAS WEST OF THE LARAMIE RANGE WEDNESDAY AFTERNOON.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...REC
LONG TERM...JG
AVIATION...GCC
FIRE WEATHER...REC