Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/04/14
AREA FORECAST DISCUSSION...UPDATED
NWS PHOENIX AZ
555 PM PM MST SUN AUG 3 2014.
&&
.SYNOPSIS...
AFTER ONE MORE DAY OF WIDESPREAD THUNDERSTORM ACTIVITY TODAY...AS A
UPPER LEVEL LOW CENTER MOVING INLAND INTO SOUTHERN CA AFFECTS OUR
REGION...A SIGNIFICANT DRYING TREND IS THEN EXPECTED TO BEGIN ON
MONDAY...UNDER SOUTHWESTERLY FLOW ALOFT...LIMITING STORM CHANCES TO
EASTERN ARIZONA THROUGH MIDWEEK. A GRADUAL RETURN OF STORM CHANCES
FROM EAST TO WEST IS THEN EXPECTED TO BEGIN BY THE END OF THE
WEEK...PERHAPS CONTINUING INTO THE UPCOMING WEEKEND.
&&
.DISCUSSION...
UPPER LOW THAT WAS OVER NRN BAJA CALIFORNIA CONTINUED TO LIFT TO THE
NORTH THIS AFTERNOON AND INTO THE EARLY EVENING...AND A VERY
PROMINENT VORT LOBE HAS ROTATED AROUND THE LOW...AND TOWARDS THE
NORTH/NORTHEAST. SIGNIFICANT CONVECTION HAS FORMED ALONG AND TO THE
NORTH OF THE VORT LOBE...AND THE SCATTERED TO NUMEROUS
SHOWERS/STORMS HAVE STEADILY LIFTED TOWARDS THIS NORTH...WITH
CLEARING SEEN BEHIND THIS FEATURE. AT 6 PM MOST OF THE CONVECTION
WAS FOCUSED OVER NORTHERN MARICOPA COUNTY...LA PAZ COUNTY AND
EASTERN RIVERSIDE COUNTY. SOME OF THE STORMS THAT HAVE DEVELOPED
HAVE BEEN VERY IMPRESSIVE WITH VILS IN EXCESS OF 70...AND ECHO TOPS
ABOVE 50K FEET. VERY HEAVY RAIN/FLASH FLOODING HAS OCCURRED IN MANY
LOCATIONS OVER THE PAST 6 HOURS...INCLUDING AREAS AROUND
WICKENBURG...BOUSE/BRENDA AND AROUND DESERT CENTER. SURFACE
DEWPOINTS LATE THIS AFTERNOON WERE ELEVATED...RANGING FROM THE MID
50S TO AROUND 70. SPC MESOANALYSIS GRAPHICS INDICATED MIXED LAYER
CAPE VALUES IN EXCESS OF 1000 J/KG OVER MUCH OF THE LOWER
DESERTS...SUPPORTIVE OF VIGOROUS CONVECTION. FOR THE NEXT FEW HOURS
CONVECTION WILL CONTINUE TO LIFT NORTH AS THE VORT LOBE AND UPPER
LOW SHIFT FURTHER NORTHWARD...AND CLEARING WILL CONTINUE BEHIND THE
LOBE. FORECASTS TRENDS LOOK OK AND NO MAJOR CHANGES ARE EXPECTED AT
THIS TIME.
.PREVIOUS DISCUSSION...
TONIGHT...
AFTER A QUIET START THIS MORNING...AS DRIER AIR ALOFT SPREAD IN FROM
THE SOUTH ACROSS THE REGION...ONE MORE BUSY AFTERNOON OF TS ACTIVITY
IS EXPECTED TO OCCUR TODAY BEFORE A SIGNIFICANT DRYING TREND TAKES
HOLD FROM MONDAY ONWARD INTO THE MIDDLE OF THIS WEEK. THE PARENT
UPPER LOW THAT BROUGHT THE MOISTURE SURGE INTO THE REGION THE LAST
FEW DAYS IS NOW MAKING ITS CLOSEST APPROACH AS IT MOVES SLOWLY
NORTHWARD INTO SOUTHERN CA. A WEAK VORT LOBE CAN BE SEEN ON WATER
VAPOR IMAGERY SLOWLY ROTATING NORTHWARD AROUND THE UPPER LOW CENTER
INTO SOUTHWEST AZ. LATEST NAM AND GFS FCST SOUNDINGS ARE SHOWING A
30KT SOUTHERLY JET MAX AT 500MB MOVING INTO SOUTHERN AZ THIS
AFTERNOON. THIS MODEST VERTICAL SHEAR...COMBINED WITH AMPLE
LOW-LEVEL MOISTURE...AND MODEST MUCAPES...IN THE 500-750 J/KG
RANGE...WILL LIKELY BE ENOUGH TO TRIGGER SCATTERED-NUMEROUS
THUNDERSTORMS THIS AFTERNOON ACROSS YUMA...LA PAZ...AND WESTERN
MARICOPA COUNTY...WITH SOMEWHAT LESS CHANCES ACROSS EASTERN MARICOPA
COUNTY. THE MAIN THREAT FROM THIS STORMS WILL BE STRONG WINDS AND
BRIEF HEAVY DOWNPOURS...SINCE THEY WILL TEND TO BE FASTER MOVING
THEN THE STORMS WE SAW YESTERDAY...WITH DECENT UPPER-LEVEL SHEAR
ENHANCING TS DOWNBURSTS. THE LATEST FEW RUNS OF THE HRRR ARE
INDICATING THAT MOST OF THE ACTIVITY ACROSS SW AND SOUTH-CENTRAL
ARIZONA WILL BE OCCURRING THIS AFTERNOON AND EARLY EVENING...WITH A
SHARP REDUCTION IN TS ACTIVITY BY LATE THIS EVENING ONCE THE VORT
LOBE PASSES TO OUR NORTH.
THE AREA OF GREATEST CONCERN TODAY CONTINUES TO BE SE CA...WHERE THE
COMBINATION OF DEEPER MOISTURE AND A MORE UNSTABLE AIRMASS CLOSER TO
THE UPPER LOW CENTER IS EXPECTED TO PRODUCE WIDESPREAD TS
DEVELOPMENT...WITH HEAVY RAIN AND FLOODING TO BE THE GREATEST
ISSUE...WITH RAINFALL AMOUNTS LOCALLY IN THE 1 TO 2 INCH RANGE
POSSIBLE...AND FLASH FLOODING/URBAN AND SMALL STREAM FLOODING. ALONG
WITH THE HEAVY RAIN AND EVEN SOME SMALL HAIL...THERE COULD ALSO BE
LOCALLY STRONG WINDS AS WET MICROBURSTS REACH THE SFC. TS ACTIVITY
OVER THIS REGION IS THEN EXPECTED TO CONTINUE INTO THE EARLY EVENING
HOURS BEFORE DIMINISHING AS THE UPPER LOW MOVES OFF TO THE NORTH.
MONDAY...
THE UPPER LOW CONTINUES MOVING NORTHWARD AND WEAKENS WITH TIME. ONE
LAST WAVE IS PROGGED TO TRACK ACROSS SOUTHEAST CALIFORNIA AND INTO
ARIZONA MONDAY BUT IT WEAKENS IN THE PROCESS. MEANWHILE...DRIER AIR
FILTERS INTO THE AREA. THUS POPS FOR MONDAY TREND DOWN...ESPECIALLY
OVER SOUTHEAST CALIFORNIA.
TUESDAY THROUGH SATURDAY...
DRY SOUTHWEST FLOW ALOFT WILL LEAD TO FURTHER DECLINE OF STORM
CHANCES WITH ONLY VERY SLIGHT CHANCES OVER THE HIGHER TERRAIN EAST
OF PHOENIX TUESDAY AND WEDNESDAY. FOR THE LATTER HALF OF THE
WEEK...BOTH GFS AND ECMWF DEPICT A MOIST ADVECTION TREND AND THUS AN
EAST TO WEST TREND OF SLIGHT CHANCE POPS OVER THE FORECAST
AREA...STOPPING SHORT OF THE LOWER COLORADO RIVER VALLEY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...KSDL...
SKIES WILL REMAIN MOSTLY CLEAR THROUGH MUCH OF THE MORNING HOURS
BEFORE SCATTERED CU DEVELOPS AROUND NOON. WIND DIRECTIONS WILL SHIFT
TO A SOUTHERLY DIRECTION BY THE AFTERNOON AND GENERALLY STAY MOSTLY
SOUTH TO SOUTHWESTERLY UNTIL STORM OUTFLOWS AFFECT THE AREA.
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FROM
LATE AFTERNOON THROUGH MID EVENING AND MAY IMPACT AREA TERMINALS FOR
A BRIEF TIME. THERE WILL BE THE POTENTIAL FOR STRONG GUSTY OUTFLOW
WINDS TODAY AS DRIER AIR AND STRONGER WINDS ALOFT MOVE INTO SOUTHERN
ARIZONA BY THIS AFTERNOON.
DUE TO LOWER CONFIDENCE IN STORM TIMING AND INTENSITY...WILL
CONTINUE TO MENTION JUST VCTS IN THE PHOENIX AREA TAFS...BEGINNING
AROUND 22Z. ONCE CONVECTION DEVELOPS AND STORMS START APPROACHING
THE TERMINALS...WE WILL UPDATE TAFS AND ADD APPROPRIATE TEMPO GROUPS
FOR THUNDER.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA......KIPL...AND KBLH...
UPPER LEVEL LOW OVER THE NORTHERN BAJA INTO FAR SOUTHERN CALIFORNIA
COAST WILL CONTINUE TO SUPPORT ISOLATED TO SCATTERED AND
THUNDERSTORM ACTIVITY THIS AFTERNOON AND EARLY EVENING. EXPECTING
THUNDERSTORM DEVELOPMENT AFTER 21Z...AND HAVE FAIRLY HIGH CONFIDENCE
OF AFFECTING AREA TERMINALS AT LEAST FOR A BRIEF TIME LATER THIS
AFTERNOON. STRONG GUSTY WINDS IN AND AROUND THUNDERSTORMS WILL BE
THE MAIN THREAT...AND VISIBILITY MAY BE BRIEFLY AND SHARPLY REDUCED
DUE TO LOCALLY HEAVY RAIN AND OR BLOWING DUST. THE UPPER LOW WILL
PULL OUT OF THE AREA THIS EVENING LEAVING CLEARING SKIES AND WEST TO
SOUTHWESTERLY WINDS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH SATURDAY...
A DRY START TO THE FORECAST PERIOD IS EXPECTED WITH ONLY SLIGHT
CHANCES OF STORMS CONFINED TO HIGHER TERRAIN AREAS NORTH AND EAST OF
PHOENIX. THIS DRY AIR WILL LIKELY LAST THROUGH THURSDAY AND
POTENTIALLY LONGER...RESULTING IN AFTERNOON MINIMUM HUMIDITY
VALUES IN THE TEENS. A GRADUAL INCREASE IN MOISTURE SHOULD BEGIN
EITHER FRIDAY OR SATURDAY ALLOWING FOR A CHANCE OF STORMS INTO THE
SOUTH-CENTRAL ARIZONA DESERTS. HIGH TEMPERATURES WILL BE RIGHT
AROUND NORMAL FOR THE ENTIRE PERIOD.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/AJ
AVIATION....KUHLMAN/CB
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
338 PM MDT SAT AUG 2 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 338 PM MDT SAT AUG 2 2014
THE AIRMASS IS DRY OVER THE MOUNTAINS AND FRONT RANGE WHERE
PRECIPITABLE WATER VALUES ARE A HALF INCH OR LESS. STILL COULD SEE A
FEW WEAK STORMS THROUGH EARLY EVENING OVER THE HIGHER
TERRAIN...MAINLY SOUTH OF I-70 WHERE THE MOISTURE IS A LITTLE
GREATER.
SATELLITE SHOWING CUMULUS CLOUDS OVER THE EASTERN PLAINS. CAPES WILL
CLIMB TO AROUND 500 J/KG BASED ON THE RAP AND PRECIPITABLE WATER
WILL BE JUST LESS THAN INCH. BECAUSE OF THIS AND THAT THE HRRR/HIRES
MODELS ARE SHOWING CONVECTION...DECIDED TO EXPAND THE LOW POPS
ACROSS THE EASTERN PLAINS THROUGH 03Z. IF ANY STORMS FORM...EXPECT
THEM TO BE WEAK AND SHORT LIVED.
ONCE THE CONVECTION DIES OFF...EXPECT MOSTLY CLEAR SKIES TONIGHT AND
SUNDAY MORNING. AIRMASS WILL SLOWLY WARM OVER THE NEXT 24 HOURS.
EXPECT LOWS TONIGHT ALONG WITH THE HIGHS SUNDAY AFTERNOON TO BE A
FEW DEGREES WARMER. MOISTURE WILL INCREASE OVER THE MOUNTAINS
SUNDAY...SO EXPECT A LITTLE BETTER CHANCE OF STORMS...SCATTERED AT
BEST. SMALL HAIL...BRIEF MODERATE RAIN AND GUSTY WINDS WILL
ACCOMPANY THE STRONGER STORMS. OVER THE PLAINS...AIRMASS WILL BE A
LITTLE DRIER AND LESS UNSTABLE. WILL JUST HAVE A SLIGHT CHANCE OVER
THE FAR NORTHEAST CORNER OF COLORADO AND LEAVE OUT THE MENTION OF
STORMS ELSEWHERE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 338 PM MDT SAT AUG 2 2014
UPPER RIDGING OVER THE STATE SUNDAY NIGHT WILL WEAKEN THROUGH
MONDAY AND TUESDAY AS A WEAK UPPER TROUGH MOVES OUT OF THE GREAT
BASIN AND OVER WYOMING. MID-LEVEL MOISTURE WILL INCREASE OVER THE
STATE. SHOWERS OVER THE MOUNTAINS STARTING MONDAY MORNING WILL
SPREAD OUT ONTO THE PLAINS MONDAY AFTERNOON. AS THE WEAK UPPER
TROUGH SLOWLY MOVES TOWARD THE NORTHERN PLAINS ON
TUESDAY...UNSETTLED WEATHER SHOULD CONTINUE ACROSS COLORAODO.
MOIST SOUTHWEST FLOW AT MID LEVELS WILL CONTINUE THROUGH THE
REMAINDER OF THE WEEK AS AN UPPER RIDGE REBUILDS OVER THE
SOUTHWESTERN UNITED STATES. TEMPERATURES SHOULD REMAIN SLIGHTLY
COOLER THAN NORMAL THROUGH THE FORECAST PERIOD. SHOWER ACTIVITY
WILL HAVE THE THREAT OF PRODUCING LOCALLY HEAVY RAIN AT TIMES DUE
TO THE SUBTROPICAL NATURE OF THE AIRMASS AND SLOW PROGRESSION OF
INDIVIDUAL STORMS. MOUNTAIN AREAS WILL SEE A CHANCE OF
THUNDERSTORMS THROUGH THE WEEK WHILE THE PLAINS SEE A LITTLE BIT
DRIER WEATHER AFTER TUESDAY.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z SUNDAY LATE AFTERNOON)
ISSUED AT 338 PM MDT SAT AUG 2 2014
A DRY AIRMASS WILL BE OVER THE DENVER AREA THROUGH SUNDAY. THIS WILL
RESULT IN MOSTLY CLEAR SKIES THE NEXT 24 HOURS. EAST TO SOUTHEAST
WINDS WILL LINGER THROUGH EARLY EVENING THEN TRANSITION TO A
DRAINAGE DIRECTION BY 06Z. LIGHT WINDS DIURNAL WINDS ARE EXPECTED
AGAIN ON SUNDAY.
&&
.HYDROLOGY...
ISSUED AT 338 PM MDT SAT AUG 2 2014
DUE TO A DRY AIRMASS...ANY STORMS THAT FORM OVER THE HIGHER TERRAIN
TODAY AND SUNDAY WILL ONLY PRODUCE LIGHT TO MODERATE RAINFALL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...MEIER
LONG TERM...DANKERS
AVIATION...MEIER
HYDROLOGY...MEIER
AREA FORECAST DISCUSSION
NWS ALBANY NY
1040 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE NEAR SOUTHEASTERN NEW JERSEY
...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM WILL BRING
SOME ISOLATED TO SCATTERED SHOWERS TO AREAS WELL SOUTH AND EAST OF
ALBANY INTO THE EARLY AFTERNOON. OTHERWISE...AN UPPER LEVEL TROUGH
OVER THE GREAT LAKES AND OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND
WEAKEN THROUGH MONDAY. THIS PATTERN WILL RESULT IN ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON AND
EARLY EVENING HOURS EACH DAY...AND ESPECIALLY ACROSS THE HIGHER
TERRAIN WEST OF THE HUDSON RIVER VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM EDT...MOSTLY CLOUDY/CLOUDY SKIES OCCURRING ACROSS THE
REGION LATE THIS MORNING...EXCEPT OVER THE SRN DACKS/WRN MOHAWK
VALLEY CORRIDOR WHERE THE SKIES HAVE CLEARED. A WEAK LOW PRESSURE
SYSTEM SE OF ATLANTIC CITY NJ CONTINUES TO STEADILY MOVE TO THE
NORTH/NORTHEAST. THE RAIN SHIELD WITH THE WAVE HAS STAYED MAINLY
SOUTH AND EAST OF THE FCST AREA. SOME ISOLD-SCT LIGHT RAIN SHOWERS
HAVE OCCURRED...AND WILL BE POSSIBLE SOUTH OF THE CAPITAL REGION
INTO THE EARLY PM.
DIURNALLY DRIVEN ISOLD-SCT SHOWERS WILL BE POSSIBLE AHEAD OF A
WEAK UPPER IMPULSE IN THE SW FLOW AHEAD OF THE UPPER LEVEL TROUGH. HIGH
RES MODELS SUCH AS THE LOCAL 5KM WRF AND HRRR INDICATE SOME ISOLD
TO PERHAPS SCT SHOWERS/ISOLD THUNDERSTORMS WELL NORTH AND WEST OF
THE CAPITAL REGION. CONTINUED MENTION OF ISOLATED THUNDERSTORMS
WHERE INSTABILITY VALUES WILL RANGE FROM 200-800 J/KG OVER THE SRN
DACKS/WRN MOHAWK VALLEY...AND THE ERN CATSKILLS. NOT MUCH
INSTABILITY IS EXPECTED FROM THE CAPITAL REGION...AND SRN VT SOUTH
AND EAST. MAX TEMPERATURES WILL END UP SLIGHTLY BELOW
NORMAL...MAINLY DUE TO THE EXPECTED MOSTLY CLOUDY SKIES ALTHOUGH
MANY AREAS WILL STILL SEE HIGHS WELL INTO THE 70S. SOME SLIGHT
ADJUSTMENTS WERE MADE TO TEMPS TO LOWER BY A FEW DEGREES OVER THE
SRN ZONES.
DIURNALLY DRIVEN CONVECTIVE SHOWERS WILL TEND TO DECREASE IN
COVERAGE BY DARK...AND EVENTUALLY DIMINISH. CANNOT RULE OUT A BRIEF
STRAY SHOWER AT SOME POINT SO WILL MENTION SLIGHT CHANCE POPS
OVERNIGHT. TEMPERATURES WILL BE MILD AGAIN WITH EXPECTED MOSTLY
CLOUDY SKIES. EXPECT LOWS TO RANGE FROM THE M50S TO L60S OVER MOST
OF THE AREA.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED UPPER TROUGH IS FORECAST TO SLOWLY MOVE EASTWARD
INTO THE EASTERN GREAT LAKES ON SUNDAY. WEAK LOW LEVEL CONVERGENCE
ALONG A SURFACE TROUGH ALONG WITH THE UPPER TROUGH WILL ALLOW FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP. DUE TO
TIMING AND LOCATION OF MAIN FEATURES...GREATER COVERAGE WILL IS
EXPECTED TO BE WEST OF THE HUDSON VALLEY. THE UPPER TROUGH WILL BE
STARTING TO DAMPEN OUT A BIT...AND INSTABILITY STILL LOOKS TO BE
RATHER LIMITED SO JUST GARDEN VARIETY THUNDERSTORMS ARE ANTICIPATED.
HOWEVER...SOME OF THE STORMS MAY BE SLOW-MOVING...WHICH WILL RESULT
IN A LOCALIZED THREAT FOR MINOR FLOODING OF URBAN AND POOR DRAINAGE
AREAS. TEMPERATURES WILL BE NEAR NORMAL...WITH AT LEAST SOME BREAKS
OF SUNSHINE EXPECTED. CONVECTION SHOULD TEND TO WANE WITH LOSS OF
DAYTIME HEATING SUNDAY NIGHT...ALTHOUGH A FEW SHOWERS COULD LINGER
INTO THE OVERNIGHT HOURS WITH THE WEAKENING UPPER TROUGH OVERHEAD.
ON MONDAY THE FLOW ALOFT FLATTENS OUT WITH SOME WEAK SHORT WAVE
ENERGY POSSIBLY MOVING THROUGH...ALONG WITH ANOTHER WEAK SURFACE
TROUGH. MODELS INDICATING GREATER INSTABILITY POSSIBLE...WITH
SBCAPES OF AROUND 1000-1500 J/KG DEVELOPING. SO AT THIS TIME IT DOES
APPEAR AT LEAST SCATTERED DIURNAL CONVECTION SHOULD OCCUR. AGAIN
SOME OF THE SLOWER MOVING STORMS COULD RESULT IN LOCALIZED MINOR
FLOODING OF URBAN AND POOR DRAINAGE AREAS. MORE SUNSHINE IS
ANTICIPATED BEFORE CONVECTION DEVELOPS...SO TEMPERATURES SHOULD WARM
INTO THE LOWER TO PERHAPS MID 80S IN VALLEY LOCATIONS. CONVECTION
SHOULD DISSIPATE MONDAY NIGHT...WITH SLIGHTLY DRIER AIR MOVING IN
RESULTING IN MARGINALLY COOLER MIN TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MEAN UPPER TROUGHING STILL WEST OF THE REGION BUT THE MEAN UPPER
TROUGH AXIS AND A PIECE OF UPPER ENERGY IS EXPECTED TO TRACK THROUGH
AND EAST OF THE REGION BY THURSDAY. UNTIL THEN...INTERVALS OF
CLOUDINESS AND ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
SHOULD BE THE RULE TUESDAY AND WEDNESDAY. HIGHS TUESDAY IN THE LOWER
TO MID 80S BUT COOLER IN HIGHER TERRAIN. HIGHS WEDNESDAY IN THE
UPPER 70S TO LOWER 80S...COOLER IN THE MOUNTAINS...AS A COLD FRONT
TRACKS THROUGH AND SOME COOLING AND DRYING BEGINS TO TAKE PLACE.
THURSDAY AND FRIDAY LOOK TO BE DRY WITH HIGHS IN THE UPPER 70S TO
LOWER 80S...COOLER IN THE MOUNTAINS. THERE ARE SOME MIXED SIGNALS AS
TO A POSSIBLE PIECE OF UPPER ENERGY APPROACHING FROM THE GREAT LAKES
FRIDAY BUT LOTS OF SPREAD IN GUIDANCE AND KEEPING THE FORECAST DRY
UNTIL THERE IS A MORE CLEAR SIGNAL FAR IN THE EXTENDED.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
NORTHERN EDGE OF RAIN SHIELD SLOWLY BUILDING NORTH AND JUST
INTERMITTENTLY AFFECTING KPOU. VFR CEILINGS OCCURRING AT KPOU...BUT
A MVFR/IFR LAYER OF CLOUDS IS TRYING TO FORM AROUND KPOU SO GOING
SCATTERED SINCE THE RAIN IS NOT BUILDING NORTH VERY MUCH. THERE ARE
A FEW SCATTERED SHOWERS HEADING TOWARD KALB AND KPSF SO PUTTING VCSH
ALL MORNING BUT AGAIN...MAINLY JUST SCATTERED SHOWERS AND IF A
SHOWER DOES AFFECT KALB OR KPSF...IT WILL BE BRIEF AND LIGHT. SOME
IFR CIGS WILL PERSIST ANOTHER HOUR OR TWO AT KPSF. THE IFR CEILING AT
KPSF SHOULD LIFT TO MVFR THIS MORNING AND REMAIN MAINLY MVFR
THROUGH THE DAY. AFTER ABOUT 13Z...ALL VISIBILITIES SHOULD BE
P6SM.
THERE ARE STILL CONSIDERABLE CONFLICTS IN SOURCES OF GUIDANCE AS TO
SOME POTENTIAL WIDESPREAD RAIN DEVELOPING THIS EVENING AND TONIGHT
WITH LOW CEILINGS AND FOG...AS ONE SET OF GUIDANCE JUST HAS
SCATTERED SHOWERS AND OTHER GUIDANCE SHOWS THE MVFR/IFR
CONDITIONS. AGAIN...JUST INDICATING VFR WITH VCSH THROUGH TONIGHT
UNTIL WEATHER EVOLUTION MORE APPARENT IN DATA AND GUIDANCE.
LIGHT SOUTH WINDS EARLY THIS MORNING SHOULD BECOME SOUTH AT 10 KT
OR LESS THIS MORNING AND THROUGH THIS EVENING.
OUTLOOK...
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
&&
.FIRE WEATHER...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON WILL BE BETWEEN 50
AND 60 PERCENT...INCREASING TO MAXIMUM VALUES OF 90 TO 100 PERCENT
TONIGHT. MIN RH ON SUNDAY AFTERNOON BE AROUND 55 TO 65 PERCENT.
WINDS TODAY WILL BE SOUTHEAST AROUND 5 MPH...BECOMING LIGHT AND
VARIABLE TONIGHT. WINDS SUNDAY WILL BE VARIABLE AROUND 5 MPH.
&&
.HYDROLOGY...
A WEAK LOW PRESSURE SYSTEM WILL BRING SOME LIGHT RAIN SHOWERS TO
SOUTHEASTERN PORTIONS OF THE HSA THIS MORNING...WITH AROUND ONE
TENTH TO ONE QUARTER INCH EXPECTED OVER PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES. OTHERWISE...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE MAINLY ACROSS THE HIGHER TERRAIN
NORTH AND WEST OF THE CAPITAL REGION THIS AFTERNOON.
SHOWERS AND THUNDERSTORMS WILL BE MAINLY CONFINED TO THE AFTERNOON
AND EARLY EVENING HOURS EACH DAY THROUGH EARLY NEXT WEEK. THERE WILL
BE A CONTINUED THREAT FOR LOCALLY HEAVY DOWNPOURS...AND ASSOCIATED
MINOR FLOODING OF POOR DRAINAGE AND URBAN AREAS IF THUNDERSTORMS
REPEATEDLY PASS OVER THE SAME LOCATIONS...ESPECIALLY SUNDAY INTO
MONDAY.
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...JPV/WASULA
NEAR TERM...JPV/WASULA
SHORT TERM...JPV
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...JPV
HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
759 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM EDT...MOSTLY CLOUDY SKIES OCCURRING ACROSS THE REGION
THIS MORNING. RAIN CONTINUES TO ENCROACHING FROM THE SOUTH
ASSOCIATED WITH A WEAK LOW PRESSURE SYSTEM OVER THE DELMARVA AND
INVERTED SURFACE TROUGH EXTENDING NORTHEASTWARD INTO SOUTHERN NEW
ENGLAND. HIGH RES MODELS AND LARGER SCALE GUIDANCE INDICATING THE
BULK OF THE RAINFALL WILL OCCUR SOUTH AND EAST OF OUR
AREA...HOWEVER A PERIOD OF SHOWERS IS LIKELY THROUGH MID OR LATE
MORNING FOR DUTCHESS...LITCHFIELD AND SOUTHERN BERKSHIRE COUNTIES.
CHANCES FOR SHOWERS DROP CONSIDERABLY NORTH AND WEST OF THESE
AREAS THIS MORNING.
THIS AFTERNOON...DIURNAL SHOWERS WILL BE POSSIBLE IN THE SOMEWHAT
DIFFLUENT AHEAD OF A SLOW-MOVING UPPER LEVEL TROUGH OVER THE GREAT
LAKES AND OHIO VALLEY REGION. HIGH RES MODELS SUCH AS THE LOCAL 5KM
WRF AND HRRR INDICATING A SMATTERING OF CONVECTIVE SHOWERS NORTH AND
WEST OF THE CAPITAL REGION...WITH TERRAIN PROVIDING THE FOCUS FOR
DISORGANIZED ACTIVITY IN A WEAKLY FORCED ENVIRONMENT. WILL MENTION
ISOLATED THUNDER WEST OF THE HUDSON RIVER VALLEY WHERE SOME LIMITED
INSTABILITY MAY DEVELOP. MAX TEMPERATURES WILL END UP SLIGHTLY BELOW
NORMAL...MAINLY DUE TO EXPECTED MOSTLY CLOUDY SKIES ALTHOUGH MANY
AREAS WILL STILL SEE HIGHS WELL INTO THE 70S.
DIURNALLY DRIVEN CONVECTIVE SHOWERS WILL TEND TO DECREASE IN
COVERAGE BY DARK...AND EVENTUALLY DIMINISH. CANNOT RULE OUT A BRIEF
STRAY SHOWER AT SOME POINT SO WILL MENTION SLIGHT CHANCE POPS
OVERNIGHT. TEMPERATURES WILL BE MILD AGAIN WITH EXPECTED MOSTLY
CLOUDY SKIES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED UPPER TROUGH IS FORECAST TO SLOWLY MOVE EASTWARD
INTO THE EASTERN GREAT LAKES ON SUNDAY. WEAK LOW LEVEL CONVERGENCE
ALONG A SURFACE TROUGH ALONG WITH THE UPPER TROUGH WILL ALLOW FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP. DUE TO
TIMING AND LOCATION OF MAIN FEATURES...GREATER COVERAGE WILL IS
EXPECTED TO BE WEST OF THE HUDSON VALLEY. THE UPPER TROUGH WILL BE
STARTING TO DAMPEN OUT A BIT...AND INSTABILITY STILL LOOKS TO BE
RATHER LIMITED SO JUST GARDEN VARIETY THUNDERSTORMS ARE ANTICIPATED.
HOWEVER...SOME OF THE STORMS MAY BE SLOW-MOVING...WHICH WILL RESULT
IN A LOCALIZED THREAT FOR MINOR FLOODING OF URBAN AND POOR DRAINAGE
AREAS. TEMPERATURES WILL BE NEAR NORMAL...WITH AT LEAST SOME BREAKS
OF SUNSHINE EXPECTED. CONVECTION SHOULD TEND TO WANE WITH LOSS OF
DAYTIME HEATING SUNDAY NIGHT...ALTHOUGH A FEW SHOWERS COULD LINGER
INTO THE OVERNIGHT HOURS WITH THE WEAKENING UPPER TROUGH OVERHEAD.
ON MONDAY THE FLOW ALOFT FLATTENS OUT WITH SOME WEAK SHORT WAVE
ENERGY POSSIBLY MOVING THROUGH...ALONG WITH ANOTHER WEAK SURFACE
TROUGH. MODELS INDICATING GREATER INSTABILITY POSSIBLE...WITH
SBCAPES OF AROUND 1000-1500 J/KG DEVELOPING. SO AT THIS TIME IT DOES
APPEAR AT LEAST SCATTERED DIURNAL CONVECTION SHOULD OCCUR. AGAIN
SOME OF THE SLOWER MOVING STORMS COULD RESULT IN LOCALIZED MINOR
FLOODING OF URBAN AND POOR DRAINAGE AREAS. MORE SUNSHINE IS
ANTICIPATED BEFORE CONVECTION DEVELOPS...SO TEMPERATURES SHOULD WARM
INTO THE LOWER TO PERHAPS MID 80S IN VALLEY LOCATIONS. CONVECTION
SHOULD DISSIPATE MONDAY NIGHT...WITH SLIGHTLY DRIER AIR MOVING IN
RESULTING IN MARGINALLY COOLER MIN TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MEAN UPPER TROUGHING STILL WEST OF THE REGION BUT THE MEAN UPPER
TROUGH AXIS AND A PIECE OF UPPER ENERGY IS EXPECTED TO TRACK THROUGH
AND EAST OF THE REGION BY THURSDAY. UNTIL THEN...INTERVALS OF
CLOUDINESS AND ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
SHOULD BE THE RULE TUESDAY AND WEDNESDAY. HIGHS TUESDAY IN THE LOWER
TO MID 80S BUT COOLER IN HIGHER TERRAIN. HIGHS WEDNESDAY IN THE
UPPER 70S TO LOWER 80S...COOLER IN THE MOUNTAINS...AS A COLD FRONT
TRACKS THROUGH AND SOME COOLING AND DRYING BEGINS TO TAKE PLACE.
THURSDAY AND FRIDAY LOOK TO BE DRY WITH HIGHS IN THE UPPER 70S TO
LOWER 80S...COOLER IN THE MOUNTAINS. THERE ARE SOME MIXED SIGNALS AS
TO A POSSIBLE PIECE OF UPPER ENERGY APPROACHING FROM THE GREAT LAKES
FRIDAY BUT LOTS OF SPREAD IN GUIDANCE AND KEEPING THE FORECAST DRY
UNTIL THERE IS A MORE CLEAR SIGNAL FAR IN THE EXTENDED.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
NORTHERN EDGE OF RAIN SHIELD SLOWLY BUILDING NORTH AND JUST
INTERMITTENTLY AFFECTING KPOU. VFR CEILINGS OCCURRING AT KPOU...BUT
A MVFR/IFR LAYER OF CLOUDS IS TRYING TO FORM AROUND KPOU SO GOING
SCATTERED SINCE THE RAIN IS NOT BUILDING NORTH VERY MUCH. THERE ARE
A FEW SCATTERED SHOWERS HEADING TOWARD KALB AND KPSF SO PUTTING VCSH
ALL MORNING BUT AGAIN...MAINLY JUST SCATTERED SHOWERS AND IF A
SHOWER DOES AFFECT KALB OR KPSF...IT WILL BE BRIEF AND LIGHT. SOME
IFR CIGS WILL PERSIST ANOTHER HOUR OR TWO AT KPSF. THE IFR CEILING AT
KPSF SHOULD LIFT TO MVFR THIS MORNING AND REMAIN MAINLY MVFR
THROUGH THE DAY. AFTER ABOUT 13Z...ALL VISIBILITIES SHOULD BE
P6SM.
THERE ARE STILL CONSIDERABLE CONFLICTS IN SOURCES OF GUIDANCE AS TO
SOME POTENTIAL WIDESPREAD RAIN DEVELOPING THIS EVENING AND TONIGHT
WITH LOW CEILINGS AND FOG...AS ONE SET OF GUIDANCE JUST HAS
SCATTERED SHOWERS AND OTHER GUIDANCE SHOWS THE MVFR/IFR
CONDITIONS. AGAIN...JUST INDICATING VFR WITH VCSH THROUGH TONIGHT
UNTIL WEATHER EVOLUTION MORE APPARENT IN DATA AND GUIDANCE.
LIGHT SOUTH WINDS EARLY THIS MORNING SHOULD BECOME SOUTH AT 10 KT
OR LESS THIS MORNING AND THROUGH THIS EVENING.
OUTLOOK...
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
&&
.FIRE WEATHER...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON WILL BE BETWEEN 50
AND 60 PERCENT...INCREASING TO MAXIMUM VALUES OF 90 TO 100 PERCENT
TONIGHT. MIN RH ON SUNDAY AFTERNOON BE AROUND 55 TO 65 PERCENT.
WINDS TODAY WILL BE SOUTHEAST AROUND 5 MPH...BECOMING LIGHT AND
VARIABLE TONIGHT. WINDS SUNDAY WILL BE VARIABLE AROUND 5 MPH.
&&
.HYDROLOGY...
A WEAK LOW PRESSURE SYSTEM WILL BRING SOME LIGHT RAIN SHOWERS TO
SOUTHEASTERN PORTIONS OF THE HSA THIS MORNING...WITH AROUND ONE
TENTH TO ONE QUARTER INCH EXPECTED OVER PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES. OTHERWISE...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE MAINLY ACROSS THE HIGHER TERRAIN
NORTH AND WEST OF THE CAPITAL REGION THIS AFTERNOON.
SHOWERS AND THUNDERSTORMS WILL BE MAINLY CONFINED TO THE AFTERNOON
AND EARLY EVENING HOURS EACH DAY THROUGH EARLY NEXT WEEK. THERE WILL
BE A CONTINUED THREAT FOR LOCALLY HEAVY DOWNPOURS...AND ASSOCIATED
MINOR FLOODING OF POOR DRAINAGE AND URBAN AREAS IF THUNDERSTORMS
REPEATEDLY PASS OVER THE SAME LOCATIONS...ESPECIALLY SUNDAY INTO
MONDAY.
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...JPV
NEAR TERM...JPV
SHORT TERM...JPV
LONG TERM...NAS
AVIATION...NAS/TAW
FIRE WEATHER...JPV
HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
645 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM EDT...MOSTLY CLOUDY SKIES OCCURRING ACROSS THE REGION
THIS MORNING. RAIN CONTINUES TO ENCROACHING FROM THE SOUTH
ASSOCIATED WITH A WEAK LOW PRESSURE SYSTEM OVER THE DELMARVA AND
INVERTED SURFACE TROUGH EXTENDING NORTHEASTWARD INTO SOUTHERN NEW
ENGLAND. HIGH RES MODELS AND LARGER SCALE GUIDANCE INDICATING THE
BULK OF THE RAINFALL WILL OCCUR SOUTH AND EAST OF OUR
AREA...HOWEVER A PERIOD OF SHOWERS IS LIKELY THROUGH MID OR LATE
MORNING FOR DUTCHESS...LITCHFIELD AND SOUTHERN BERKSHIRE COUNTIES.
CHANCES FOR SHOWERS DROP CONSIDERABLY NORTH AND WEST OF THESE
AREAS THIS MORNING.
THIS AFTERNOON...DIURNAL SHOWERS WILL BE POSSIBLE IN THE SOMEWHAT
DIFFLUENT AHEAD OF A SLOW-MOVING UPPER LEVEL TROUGH OVER THE GREAT
LAKES AND OHIO VALLEY REGION. HIGH RES MODELS SUCH AS THE LOCAL 5KM
WRF AND HRRR INDICATING A SMATTERING OF CONVECTIVE SHOWERS NORTH AND
WEST OF THE CAPITAL REGION...WITH TERRAIN PROVIDING THE FOCUS FOR
DISORGANIZED ACTIVITY IN A WEAKLY FORCED ENVIRONMENT. WILL MENTION
ISOLATED THUNDER WEST OF THE HUDSON RIVER VALLEY WHERE SOME LIMITED
INSTABILITY MAY DEVELOP. MAX TEMPERATURES WILL END UP SLIGHTLY BELOW
NORMAL...MAINLY DUE TO EXPECTED MOSTLY CLOUDY SKIES ALTHOUGH MANY
AREAS WILL STILL SEE HIGHS WELL INTO THE 70S.
DIURNALLY DRIVEN CONVECTIVE SHOWERS WILL TEND TO DECREASE IN
COVERAGE BY DARK...AND EVENTUALLY DIMINISH. CANNOT RULE OUT A BRIEF
STRAY SHOWER AT SOME POINT SO WILL MENTION SLIGHT CHANCE POPS
OVERNIGHT. TEMPERATURES WILL BE MILD AGAIN WITH EXPECTED MOSTLY
CLOUDY SKIES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED UPPER TROUGH IS FORECAST TO SLOWLY MOVE EASTWARD
INTO THE EASTERN GREAT LAKES ON SUNDAY. WEAK LOW LEVEL CONVERGENCE
ALONG A SURFACE TROUGH ALONG WITH THE UPPER TROUGH WILL ALLOW FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP. DUE TO
TIMING AND LOCATION OF MAIN FEATURES...GREATER COVERAGE WILL IS
EXPECTED TO BE WEST OF THE HUDSON VALLEY. THE UPPER TROUGH WILL BE
STARTING TO DAMPEN OUT A BIT...AND INSTABILITY STILL LOOKS TO BE
RATHER LIMITED SO JUST GARDEN VARIETY THUNDERSTORMS ARE ANTICIPATED.
HOWEVER...SOME OF THE STORMS MAY BE SLOW-MOVING...WHICH WILL RESULT
IN A LOCALIZED THREAT FOR MINOR FLOODING OF URBAN AND POOR DRAINAGE
AREAS. TEMPERATURES WILL BE NEAR NORMAL...WITH AT LEAST SOME BREAKS
OF SUNSHINE EXPECTED. CONVECTION SHOULD TEND TO WANE WITH LOSS OF
DAYTIME HEATING SUNDAY NIGHT...ALTHOUGH A FEW SHOWERS COULD LINGER
INTO THE OVERNIGHT HOURS WITH THE WEAKENING UPPER TROUGH OVERHEAD.
ON MONDAY THE FLOW ALOFT FLATTENS OUT WITH SOME WEAK SHORT WAVE
ENERGY POSSIBLY MOVING THROUGH...ALONG WITH ANOTHER WEAK SURFACE
TROUGH. MODELS INDICATING GREATER INSTABILITY POSSIBLE...WITH
SBCAPES OF AROUND 1000-1500 J/KG DEVELOPING. SO AT THIS TIME IT DOES
APPEAR AT LEAST SCATTERED DIURNAL CONVECTION SHOULD OCCUR. AGAIN
SOME OF THE SLOWER MOVING STORMS COULD RESULT IN LOCALIZED MINOR
FLOODING OF URBAN AND POOR DRAINAGE AREAS. MORE SUNSHINE IS
ANTICIPATED BEFORE CONVECTION DEVELOPS...SO TEMPERATURES SHOULD WARM
INTO THE LOWER TO PERHAPS MID 80S IN VALLEY LOCATIONS. CONVECTION
SHOULD DISSIPATE MONDAY NIGHT...WITH SLIGHTLY DRIER AIR MOVING IN
RESULTING IN MARGINALLY COOLER MIN TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MEAN UPPER TROUGHING STILL WEST OF THE REGION BUT THE MEAN UPPER
TROUGH AXIS AND A PIECE OF UPPER ENERGY IS EXPECTED TO TRACK THROUGH
AND EAST OF THE REGION BY THURSDAY. UNTIL THEN...INTERVALS OF
CLOUDINESS AND ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
SHOULD BE THE RULE TUESDAY AND WEDNESDAY. HIGHS TUESDAY IN THE LOWER
TO MID 80S BUT COOLER IN HIGHER TERRAIN. HIGHS WEDNESDAY IN THE
UPPER 70S TO LOWER 80S...COOLER IN THE MOUNTAINS...AS A COLD FRONT
TRACKS THROUGH AND SOME COOLING AND DRYING BEGINS TO TAKE PLACE.
THURSDAY AND FRIDAY LOOK TO BE DRY WITH HIGHS IN THE UPPER 70S TO
LOWER 80S...COOLER IN THE MOUNTAINS. THERE ARE SOME MIXED SIGNALS AS
TO A POSSIBLE PIECE OF UPPER ENERGY APPROACHING FROM THE GREAT LAKES
FRIDAY BUT LOTS OF SPREAD IN GUIDANCE AND KEEPING THE FORECAST DRY
UNTIL THERE IS A MORE CLEAR SIGNAL FAR IN THE EXTENDED.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
NORTHERN EDGE OF RAIN SHIELD SLOWLY BUILDING NORTH AND AFTER
SUNRISE SOME LIGHT RAIN COULD AFFECT KPOU. MVFR CEILINGS SHOULD
PREVAIL THROUGH THE MORNING HOURS AT KPSF AND KPOU...WITH SOME
MVFR FOG AT KPOU. AFTER ABOUT 13Z...ALL AREAS SHOULD BE
VFR EXCEPT KPOU WHERE MVFR AND THE POTENTIAL FOR SOME LIGHT RAIN
CONTINUES THROUGH ABOUT 16Z AND KPSF WHERE SOME LOW CLOUDS
COULD HANG ON UNTIL AROUND 17Z.
SHOWERS COULD BE IN THE VICINITY OF ALL SITES TOMORROW AFTERNOON
AND EVENING BUT VFR CONDITIONS SHOULD PREVAIL TOMORROW AFTERNOON
AND EVENING OUTSIDE OF SCATTERED SHOWERS. THERE ARE CONSIDERABLE
CONFLICTS IN SOURCES OF GUIDANCE AS TO SOME POTENTIAL WIDESPREAD
RAIN DEVELOPING TOMORROW EVENING WITH LOW CEILINGS AND FOG...AS
ONE SET OF GUIDANCE JUST HAS SCATTERED SHOWERS AND OTHER GUIDANCE
SHOWS THE MVFR/IFR CONDITIONS. AGAIN...JUST INDICATING VFR WITH
VCSH TOMORROW EVENING UNTIL WEATHER EVOLUTION MORE APPARENT IN
DATA AND GUIDANCE.
LIGHT SOUTH WINDS EARLY THIS MORNING SHOULD BECOME SOUTH AT 10 KT
OR LESS THIS MORNING AND THROUGH THIS EVENING.
OUTLOOK...
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
&&
.FIRE WEATHER...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON WILL BE BETWEEN 50
AND 60 PERCENT...INCREASING TO MAXIMUM VALUES OF 90 TO 100 PERCENT
TONIGHT. MIN RH ON SUNDAY AFTERNOON BE AROUND 55 TO 65 PERCENT.
WINDS TODAY WILL BE SOUTHEAST AROUND 5 MPH...BECOMING LIGHT AND
VARIABLE TONIGHT. WINDS SUNDAY WILL BE VARIABLE AROUND 5 MPH.
&&
.HYDROLOGY...
A WEAK LOW PRESSURE SYSTEM WILL BRING SOME LIGHT RAIN SHOWERS TO
SOUTHEASTERN PORTIONS OF THE HSA THIS MORNING...WITH AROUND ONE
TENTH TO ONE QUARTER INCH EXPECTED OVER PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES. OTHERWISE...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE MAINLY ACROSS THE HIGHER TERRAIN
NORTH AND WEST OF THE CAPITAL REGION THIS AFTERNOON.
SHOWERS AND THUNDERSTORMS WILL BE MAINLY CONFINED TO THE AFTERNOON
AND EARLY EVENING HOURS EACH DAY THROUGH EARLY NEXT WEEK. THERE WILL
BE A CONTINUED THREAT FOR LOCALLY HEAVY DOWNPOURS...AND ASSOCIATED
MINOR FLOODING OF POOR DRAINAGE AND URBAN AREAS IF THUNDERSTORMS
REPEATEDLY PASS OVER THE SAME LOCATIONS...ESPECIALLY SUNDAY INTO
MONDAY.
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...JPV
NEAR TERM...JPV
SHORT TERM...JPV
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...JPV
HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
409 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 400 AM EDT...DRY CONDITIONS TO START THE MORNING ACROSS MUCH
OF THE AREA UNDER A CANOPY OF MID LEVEL CLOUDS. HOWEVER...RAIN IS
SLOWLY ENCROACHING FROM THE SOUTH ASSOCIATED WITH A WEAK LOW
PRESSURE SYSTEM OVER THE DELMARVA AND INVERTED SURFACE TROUGH
EXTENDING NORTHEASTWARD INTO SOUTHERN NEW ENGLAND. HIGH RES MODELS
AND LARGER SCALE GUIDANCE INDICATING THE BULK OF THE RAINFALL WILL
OCCUR SOUTH AND EAST OF OUR AREA...HOWEVER A PERIOD OF SHOWERS IS
LIKELY FROM AROUND SUNRISE TO MID MORNING FOR DUTCHESS...LITCHFIELD
AND SOUTHERN BERKSHIRE COUNTIES. CHANCES FOR SHOWERS DROP
CONSIDERABLY NORTH AND WEST OF THESE AREAS THIS MORNING.
THIS AFTERNOON...DIURNAL SHOWERS WILL BE POSSIBLE IN THE SOMEWHAT
DIFFLUENT AHEAD OF A SLOW-MOVING UPPER LEVEL TROUGH OVER THE GREAT
LAKES AND OHIO VALLEY REGION. HIGH RES MODELS SUCH AS THE LOCAL 5KM
WRF AND HRRR INDICATING A SMATTERING OF CONVECTIVE SHOWERS NORTH AND
WEST OF THE CAPITAL REGION...WITH TERRAIN PROVIDING THE FOCUS FOR
DISORGANIZED ACTIVITY IN A WEAKLY FORCED ENVIRONMENT. WILL MENTION
ISOLATED THUNDER WEST OF THE HUDSON RIVER VALLEY WHERE SOME LIMITED
INSTABILITY MAY DEVELOP. MAX TEMPERATURES WILL END UP SLIGHTLY BELOW
NORMAL...MAINLY DUE TO EXPECTED MOSTLY CLOUDY SKIES ALTHOUGH MANY
AREAS WILL STILL SEE HIGHS WELL INTO THE 70S.
DIURNALLY DRIVEN CONVECTIVE SHOWERS WILL TEND TO DECREASE IN
COVERAGE BY DARK...AND EVENTUALLY DIMINISH. CANNOT RULE OUT A BRIEF
STRAY SHOWER AT SOME POINT SO WILL MENTION SLIGHT CHANCE POPS
OVERNIGHT. TEMPERATURES WILL BE MILD AGAIN WITH EXPECTED MOSTLY
CLOUDY SKIES.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
THE AFOREMENTIONED UPPER TROUGH IS FORECAST TO SLOWLY MOVE EASTWARD
INTO THE EASTERN GREAT LAKES ON SUNDAY. WEAK LOW LEVEL CONVERGENCE
ALONG A SURFACE TROUGH ALONG WITH THE UPPER TROUGH WILL ALLOW FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP. DUE TO
TIMING AND LOCATION OF MAIN FEATURES...GREATER COVERAGE WILL IS
EXPECTED TO BE WEST OF THE HUDSON VALLEY. THE UPPER TROUGH WILL BE
STARTING TO DAMPEN OUT A BIT...AND INSTABILITY STILL LOOKS TO BE
RATHER LIMITED SO JUST GARDEN VARIETY THUNDERSTORMS ARE ANTICIPATED.
HOWEVER...SOME OF THE STORMS MAY BE SLOW-MOVING...WHICH WILL RESULT
IN A LOCALIZED THREAT FOR MINOR FLOODING OF URBAN AND POOR DRAINAGE
AREAS. TEMPERATURES WILL BE NEAR NORMAL...WITH AT LEAST SOME BREAKS
OF SUNSHINE EXPECTED. CONVECTION SHOULD TEND TO WANE WITH LOSS OF
DAYTIME HEATING SUNDAY NIGHT...ALTHOUGH A FEW SHOWERS COULD LINGER
INTO THE OVERNIGHT HOURS WITH THE WEAKENING UPPER TROUGH OVERHEAD.
ON MONDAY THE FLOW ALOFT FLATTENS OUT WITH SOME WEAK SHORT WAVE
ENERGY POSSIBLY MOVING THROUGH...ALONG WITH ANOTHER WEAK SURFACE
TROUGH. MODELS INDICATING GREATER INSTABILITY POSSIBLE...WITH
SBCAPES OF AROUND 1000-1500 J/KG DEVELOPING. SO AT THIS TIME IT DOES
APPEAR AT LEAST SCATTERED DIURNAL CONVECTION SHOULD OCCUR. AGAIN
SOME OF THE SLOWER MOVING STORMS COULD RESULT IN LOCALIZED MINOR
FLOODING OF URBAN AND POOR DRAINAGE AREAS. MORE SUNSHINE IS
ANTICIPATED BEFORE CONVECTION DEVELOPS...SO TEMPERATURES SHOULD WARM
INTO THE LOWER TO PERHAPS MID 80S IN VALLEY LOCATIONS. CONVECTION
SHOULD DISSIPATE MONDAY NIGHT...WITH SLIGHTLY DRIER AIR MOVING IN
RESULTING IN MARGINALLY COOLER MIN TEMPERATURES.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
MEAN UPPER TROUGHING STILL WEST OF THE REGION BUT THE MEAN UPPER
TROUGH AXIS AND A PIECE OF UPPER ENERGY IS EXPECTED TO TRACK THROUGH
AND EAST OF THE REGION BY THURSDAY. UNTIL THEN...INTERVALS OF
CLOUDINESS AND ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
SHOULD BE THE RULE TUESDAY AND WEDNESDAY. HIGHS TUESDAY IN THE LOWER
TO MID 80S BUT COOLER IN HIGHER TERRAIN. HIGHS WEDNESDAY IN THE
UPPER 70S TO LOWER 80S...COOLER IN THE MOUNTAINS...AS A COLD FRONT
TRACKS THROUGH AND SOME COOLING AND DRYING BEGINS TO TAKE PLACE.
THURSDAY AND FRIDAY LOOK TO BE DRY WITH HIGHS IN THE UPPER 70S TO
LOWER 80S...COOLER IN THE MOUNTAINS. THERE ARE SOME MIXED SIGNALS AS
TO A POSSIBLE PIECE OF UPPER ENERGY APPROACHING FROM THE GREAT LAKES
FRIDAY BUT LOTS OF SPREAD IN GUIDANCE AND KEEPING THE FORECAST DRY
UNTIL THERE IS A MORE CLEAR SIGNAL FAR IN THE EXTENDED.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
NORTHERN EDGE OF RAIN SHIELD SLOWLY BUILDING NORTH AND AFTER
SUNRISE SOME LIGHT RAIN COULD AFFECT KPOU. MVFR CEILINGS SHOULD
PREVAIL THROUGH THE MORNING HOURS AT KPSF AND KPOU...WITH SOME
MVFR FOG AT KPOU. AFTER ABOUT 13Z...ALL AREAS SHOULD BE
VFR EXCEPT KPOU WHERE MVFR AND THE POTENTIAL FOR SOME LIGHT RAIN
CONTINUES THROUGH ABOUT 16Z AND KPSF WHERE SOME LOW CLOUDS
COULD HANG ON UNTIL AROUND 17Z.
SHOWERS COULD BE IN THE VICINITY OF ALL SITES TOMORROW AFTERNOON
AND EVENING BUT VFR CONDITIONS SHOULD PREVAIL TOMORROW AFTERNOON
AND EVENING OUTSIDE OF SCATTERED SHOWERS. THERE ARE CONSIDERABLE
CONFLICTS IN SOURCES OF GUIDANCE AS TO SOME POTENTIAL WIDESPREAD
RAIN DEVELOPING TOMORROW EVENING WITH LOW CEILINGS AND FOG...AS
ONE SET OF GUIDANCE JUST HAS SCATTERED SHOWERS AND OTHER GUIDANCE
SHOWS THE MVFR/IFR CONDITIONS. AGAIN...JUST INDICATING VFR WITH
VCSH TOMORROW EVENING UNTIL WEATHER EVOLUTION MORE APPARENT IN
DATA AND GUIDANCE.
LIGHT SOUTH WINDS EARLY THIS MORNING SHOULD BECOME SOUTH AT 10 KT
OR LESS THIS MORNING AND THROUGH THIS EVENING.
OUTLOOK...
SUNDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
MONDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
MONDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
WEDNESDAY: MODERATE OPERATIONAL IMPACT. SCATTERED SHRA...TSRA.
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. ISOLATED SHRA...TSRA.
&&
.FIRE WEATHER...
A WEAK AREA OF LOW PRESSURE OVER THE NORTHERN MID ATLANTIC COAST
THIS MORNING...WILL TRACK TO THE GULF OF MAINE TONIGHT. THIS SYSTEM
WILL BRING SOME SHOWERS TO AREAS WELL SOUTH AND EAST OF ALBANY THIS
MORNING. OTHERWISE...AN UPPER LEVEL TROUGH OVER THE GREAT LAKES AND
OHIO VALLEY WILL SLOWLY MOVE EASTWARD AND WEAKEN THROUGH MONDAY.
THIS PATTERN WILL RESULT IN ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS MAINLY DURING THE AFTERNOON AND EARLY EVENING HOURS
EACH DAY...AND ESPECIALLY ACROSS THE HIGHER TERRAIN WEST OF THE
HUDSON RIVER VALLEY.
MINIMUM RELATIVE HUMIDITY VALUES THIS AFTERNOON WILL BE BETWEEN 50
AND 60 PERCENT...INCREASING TO MAXIMUM VALUES OF 90 TO 100 PERCENT
TONIGHT. MIN RH ON SUNDAY AFTERNOON BE AROUND 55 TO 65 PERCENT.
WINDS TODAY WILL BE SOUTHEAST AROUND 5 MPH...BECOMING LIGHT AND
VARIABLE TONIGHT. WINDS SUNDAY WILL BE VARIABLE AROUND 5 MPH.
&&
.HYDROLOGY...
A WEAK LOW PRESSURE SYSTEM WILL BRING SOME LIGHT RAIN SHOWERS TO
SOUTHEASTERN PORTIONS OF THE HSA THIS MORNING...WITH AROUND ONE
TENTH TO ONE QUARTER INCH EXPECTED OVER PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES. OTHERWISE...ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE MAINLY ACROSS THE HIGHER TERRAIN
NORTH AND WEST OF THE CAPITAL REGION THIS AFTERNOON.
SHOWERS AND THUNDERSTORMS WILL BE MAINLY CONFINED TO THE AFTERNOON
AND EARLY EVENING HOURS EACH DAY THROUGH EARLY NEXT WEEK. THERE WILL
BE A CONTINUED THREAT FOR LOCALLY HEAVY DOWNPOURS...AND ASSOCIATED
MINOR FLOODING OF POOR DRAINAGE AND URBAN AREAS IF THUNDERSTORMS
REPEATEDLY PASS OVER THE SAME LOCATIONS...ESPECIALLY SUNDAY INTO
MONDAY.
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...JPV
NEAR TERM...JPV
SHORT TERM...JPV
LONG TERM...NAS
AVIATION...NAS
FIRE WEATHER...JPV
HYDROLOGY...11/JPV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
949 PM EDT SUN AUG 3 2014
.SYNOPSIS...
AN UPPER LOW OVER WESTERN PENNSYLVANIA THIS AFTERNOON WILL LIFT
NORTHEAST INTO NEW ENGLAND TONIGHT. MEANWHILE, A FRONTAL BOUNDARY
WILL REMAIN POSITIONED OFF THE EAST COAST EARLY THIS WEEK. TROPICAL
STORM BERTHA IS FORECAST TO TRACK NORTHWARD OFF THE SOUTHEAST COAST
MONDAY BEFORE RE-CURVING TO THE NORTHEAST TUESDAY, WELL EAST OF THE
MID-ATLANTIC COAST. A COLD FRONT WILL MOVE THROUGH THE REGION
WEDNESDAY. THE FRONT IS EXPECTED TO STALL JUST SOUTH OF THE AREA
LATE IN THE WEEK INTO NEXT WEEKEND AS HIGH PRESSURE ATTEMPTS TO
BUILD IN FROM THE GREAT LAKES.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AN UPPER LOW WHICH IS CURRENTLY MOVING SLOWLY ACROSS WRN/CNTRL PA
WILL WEAKEN AND MOVE NORTH OF THE REGION TONIGHT. IT HAS CAUSED
SHOWERS WITH HEAVY RAINS ACROSS WRN/CNTRL PA SO FAR. RIGHT NOW
THE HRRR, RAP AND THE HIRES 18Z NAM ARE TARGETING A CLUSTER OF
SHOWERS AND THUNDER OVER MARYLAND AND SOUTHERN PA TO MOVE EAST
TOWARD THE EASTERN SHORE OF MD AND CHESTER/BERKS COUNTIES PA
THROUGH THE LATE EVENING INTO THE OVERNIGHT PERIOD. HAVE RAISED
POPS TO LIKELY FOR A BRIEF WINDOW ALONG THE EASTERN SHORE OF
MARYLAND FOR A FEW HOURS AND BUMPED UP QPF. THE SHOWERS AND
THUNDER SHOULD DISSIPATE IN THE EARLY OVERNIGHT HOURS. FOG IS EXPECTED
TO DEVELOP OVERNIGHT...AND WE HAVE INCLUDED AREAS OF FOG IN THE
GRIDS. LOWS TONIGHT WILL RANGE FROM THE UPPER 50S NORTH TO THE
UPPER 60D SOUTH. MET/MAV MOS TEMPS WERE USED FOR THE FCST AND
LAV GUIDANCE WAS INCORPORATED FOR THE NEXT FEW HOURS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE WEAK UPPER LOW WILL HAVE MOVED AWAY BY MON MORNING AND WITH HIGH
PRESSURE STARTING TO MOVE TOWARD THE AREA...A BETTER WEATHER DAY IS
EXPECTED. THERE WILL BE SOME FOG EARLY...BUT DRIER AIR ALOFT WILL
LEAD TO AT LEAST PARTLY SUNNY SKIES BY AFTERNOON. SCT SHOWERS WILL
PROBABLY DEVELOP DURING THE AFTERNOON...BUT COVERAGE WILL NOT BE AS
WIDESPREAD AS THE PAST FEW DAYS. TEMPERATURES WILL JUMP BACK TO
NORMAL LEVELS WITH MOSTLY MID 80S ACROSS THE AREA. WINDS WILL BE
WRLY/NWRLY AT 5 TO 10 MPH.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
LARGE-SCALE PATTERN WILL FEATURE A PERSISTENT TROUGH OVER THE ERN
CONUS THRU MUCH OF THE WEEK. SEVERAL SHORTWAVE DISTURBANCES ROTATING
AROUND THE MAIN TROUGH WILL PROVIDE THE CHANCE OF SHOWERS AND
THUNDERSTORMS THRU MIDWEEK, PARTICULARLY ON WEDNESDAY WHEN A COLD
FRONT MOVES THRU THE CWA. ALSO, DO NOT EXPECT ANY HEATWAVES TO OCCUR
ACROSS OUR REGION UNDER THIS SETUP. TEMPS WILL BE NEAR NORMAL
THROUGHOUT THE LONG-TERM PERIOD. THE WARMEST DAY EXPECTED IN THE
PERIOD IS TUESDAY, BUT MAX TEMPS IN THE MU 80S (PERHAPS REACHING
90F IN A FEW SPOTS) AND MIN TEMPS IN THE MU 60S MONDAY NIGHT AND
TUESDAY NIGHT WOULD ONLY BE AT OR A COUPLE OF DEGREES ABOVE NORMAL
FOR EARLY AUGUST.
MONDAY NIGHT SHOULD BE DRY ACROSS MOST OF THE REGION. TROPICAL STORM
BERTHA IS EXPECTED TO INTERACT WITH THE STALLED OFFSHORE BOUNDARY AS
IT TRACKS EAST OF THE OUTERBANKS. CANNOT RULE OUT A FEW SHOWERS ON
THE NRN PERIPHERY OF THE SYSTEM REACHING THE DELMARVA.
BERTHA IS FORECAST BY THE NATIONAL HURRICANE CENTER TO RE-CURVE TO
THE NORTHEAST TUESDAY AND TUESDAY NIGHT, WITH A TRACK THAT IS WELL
EAST OF THE DELMARVA/NJ COAST. MODEST LIFT PROVIDED BY AN UPSTREAM
SHORTWAVE TROUGH MAY YIELD ISO TO SCT SHOWERS/TSTMS ON TUESDAY.
CONFINED LOW CHANCE POPS TO THE SOUTHERN TIER OF THE CWA, WHERE
DIFFERENTIAL HEATING MAY PROVIDE A FOCUS FOR DIURNAL CONVECTION ON
THE NWRN PERIPHERY OF THE TROPICAL SYSTEM AND ALSO IN THE POCONOS,
WHERE CONVECTION COULD INITIATE OVER THE HIGHER TERRAIN.
A BETTER CHANCE FOR SHOWERS AND STORMS EXPECTED ON WEDNESDAY WHEN A
COLD FRONT MOVES THRU THE AREA. LATEST TREND IN THE FCST WAS TO
RAISE POPS A BIT TO 40-50 PERCENT SINCE THERE IS BETTER MODEL
AGREEMENT REGARDING THE POSITION/TIMING OF THE COLD FRONT, ULVL JET
STREAK AND THE UPPER SHORTWAVE TROUGH. IT APPEARS THAT FAVORABLE
DYNAMICS FROM THESE FEATURES WILL BECOME JUXTAPOSED OVER THE CWA FOR
A PERIOD WEDNESDAY AFTERNOON.
THE FRONT IS FORECAST TO GRADUALLY SHIFT SOUTH OF THE AREA WEDNESDAY
NIGHT BEFORE STALLING SOMEWHERE NEAR THE NC-VA BORDER LATE IN THE
WEEK. ISO SHOWERS POSSIBLE IN EXTREME NERN PA/NRN NJ THURSDAY
AFTERNOON AS COLD POOL ASSOCIATED WITH A TROUGH ALOFT PROVIDES SOME
INSTABILITY. CONVECTION WOULD BE MAINLY DIURNALLY-DRIVEN, LOW-TOPPED
AND ANY COVERAGE OF SHOWERS/STORMS SHOULD BE LOW.
MODEL SPREAD DOES INCREASE LATE IN THE PERIOD, PARTICULARLY THIS
WEEKEND IN REGARDS TO THE POSITION OF THE BOUNDARY AND THE
DEVELOPMENT OF LOPRES ALONG THAT BOUNDARY. ATTM...KEPT THE FCST
NEXT WEEKEND DRY, BUT IF MODELS CONTINUE TO TREND FARTHER
NORTHWARD, PRECIP CHANCES MAY NEED TO BE ADDED, ESPECIALLY ACROSS
THE SRN TIER.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
CONDITIONS AT MOST TAF SITES HAVE BEEN BOUNCING AROUND BETWEEN MVFR
AND VFR THROUGH THE EVENING WITH KMIV AND KACY HAVE BEEN MORE
CONSTANTLY MVFR. THIS IS EXPECTED TO CONTINUE FOR THE NEXT FEW
HOURS. INDICATIONS ARE MIXED FOR THE OVERNIGHT WITH HOW QUICKLY
THE VISIBILITIES WILL LOWER TO LIFR DUE TO POTENTIAL FOG/LOW CLOUD
DEVELOPMENT AT KMIV AND KACY. TO REFLECT SOME UNCERTAINTY TEMPO
GROUPS WERE USED TO SHOW THE POTENTIAL TIME RANGE OF LIFR
CEILINGS. ELSEWHERE VISIBILITIES WILL BE SLOWER TO DROP AND THE
POTENTIAL FOR LIFR CONDITIONS IS MORE UNCERTAIN, TEMPO GROUPS WERE
HERE AS WELL WITH SOME POTENTIAL TO REMAIN AT MVFR OVERNIGHT.
MONDAY...AFTER THE FOG/LOW CLOUDS BURNS OFF BETWEEN 12-14Z...VFR
EXPECTED WITH WEST/NORTHWEST WINDS AROUND 10 KTS BY NOON POSSIBLY
BECOMING MORE SOUTHWEST.
OUTLOOK...
MONDAY NIGHT AND TUESDAY...PREDOMINATELY VFR WITH LOW CHANCE FOR
SHRA/TSRA MAINLY SOUTH OF PHILA TERMINALS. LIGHT WINDS DURING THE
PERIOD.
TUESDAY NIGHT AND WEDNESDAY...COLD FRONT APPROACHES TUESDAY NIGHT.
CHANCE FOR SHRA/TSRA WITH HIGHEST COVERAGE OF CONVECTION EXPECTED
WEDNESDAY AFTERNOON AS THE COLD FRONT MOVES THRU. MAINLY VFR BUT
LOCAL/TEMPORARY FLIGHT RESTRICTIONS WOULD BE ANTICIPATED IN HEAVIER
ACTIVITY.
WEDNESDAY NIGHT THROUGH FRIDAY...COLD FRONT MOVES SOUTH OF THE
TERMINALS. ATTM, EXPECT A MAINLY DRY PERIOD WITH HIPRES TRYING TO
BUILD IN FROM THE GREAT LAKES.
&&
.MARINE...
RATHER SHOWERY/FOGGY CONDITIONS ACROSS THE WATERS AS A FRONT AND
WAVES OF LOW PRESSURE MOVE ALONG IT. THE FRONT WILL EDGE EASTWARD
TONIGHT BRINGING SCT SHOWERS AND LIGHT WINDS. WIND DIRECTIONS WHICH
HAVE BEEN MOSTLY NE OR E WILL SWITCH MORE WRLY/NWRLY ON MONDAY. SEAS
ON THE OCEAN WILL REMAIN MOSTLY AROUND 3 FT. OVER DEL BAY...SE WINDS
WILL BECOME NW MONDAY WITH SPEEDS 5 TO 10 KTS. AREAS OF FOG ARE
POSSIBLE TONIGHT WITH LOWER VSBYS.
OUTLOOK...
MONDAY NIGHT...NO HAZARDS EXPECTED ON THE WATERS.
TUESDAY THROUGH WEDNESDAY...TROPICAL STORM BERTHA IS EXPECTED TO
TRACK WELL EAST OF THE AREA, BUT IS FORECAST TO PRODUCE WAVES OF
3-4 FT. IF THE TRACK OF BERTHA SHIFTS CLOSER TO THE COAST, LOCALLY
HIGHER WAVES MAY REACH SCA CRITERIA. LONG-PERIOD SWELLS OF 10-13
S ARE CURRENTLY FORECAST FOR TUESDAY AND WEDNESDAY.
WEDNESDAY NIGHT THROUGH FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.
&&
.RIP CURRENTS...
THERE REMAINS SOME ENHANCED WAVE ACTION ALONG THE COAST THIS
AFTERNOON. CONTINUE TO HIGHLIGHT A MODERATE RISK OF RIP CURRENTS
THROUGH TOMORROW.
LONG PERIOD SWELLS FROM TROPICAL STORM BERTHA MAY AFFECT THE
COASTS OF DELAWARE AND NEW JERSEY FROM LATE MONDAY INTO WEDNESDAY.
THE SWELLS COULD BRING AN ENHANCED THREAT FOR DANGEROUS RIP
CURRENTS DURING THIS TIME.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GAINES/O`HARA
SHORT TERM...O`HARA
LONG TERM...KLEIN
AVIATION...GAINES/KLEIN/O`HARA
MARINE...KLEIN/O`HARA
RIP CURRENTS...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
945 PM EDT SUN AUG 3 2014
.SYNOPSIS...
AN UPPER LOW OVER WESTERN PENNSYLVANIA THIS AFTERNOON WILL LIFT
NORTHEAST INTO NEW ENGLAND TONIGHT. MEANWHILE, A FRONTAL BOUNDARY
WILL REMAIN POSITIONED OFF THE EAST COAST EARLY THIS WEEK. TROPICAL
STORM BERTHA IS FORECAST TO TRACK NORTHWARD OFF THE SOUTHEAST COAST
MONDAY BEFORE RE-CURVING TO THE NORTHEAST TUESDAY, WELL EAST OF THE
MID-ATLANTIC COAST. A COLD FRONT WILL MOVE THROUGH THE REGION
WEDNESDAY. THE FRONT IS EXPECTED TO STALL JUST SOUTH OF THE AREA
LATE IN THE WEEK INTO NEXT WEEKEND AS HIGH PRESSURE ATTEMPTS TO
BUILD IN FROM THE GREAT LAKES.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AN UPPER LOW WHICH IS CURRENTLY MOVING SLOWLY ACROSS WRN/CNTRL PA
WILL WEAKEN AND MOVE NORTH OF THE REGION TONIGHT. IT HAS CAUSED
SHOWERS WITH HEAVY RAINS ACROSS WRN/CNTRL PA SO FAR. RIGHT NOW
THE HRRR, RAP AND THE HIRES 18Z NAM ARE TARGETING A CLUSTER OF
SHOWERS AND THUNDER OVER MARYLAND AND SOUTHERN PA TO MOVE EAST
TOWARD THE EASTERN SHORE OF MD AND CHESTER/BERKS COUNTIES PA
THROUGH THE LATE EVENING INTO THE OVERNIGHT PERIOD. HAVE RAISED
POPS TO LIKELY FOR A BRIEF WINDOW ALONG THE EASTERN SHORE OF
MARYLAND FOR A FEW HOURS AND BUMPED UP QPF. THE SHOWERS AND
THUNDER SHOULD DISSIPATE IN THE EARLY OVERNIGHT HOURS. FOG IS EXPECTED
TO DEVELOP OVERNIGHT...AND WE HAVE INCLUDED AREAS OF FOG IN THE
GRIDS. LOWS TONIGHT WILL RANGE FROM THE UPPER 50S NORTH TO THE
UPPER 60D SOUTH. MET/MAV MOS TEMPS WERE USED FOR THE FCST AND
LAV GUIDANCE WAS INCORPORATED FOR THE NEXT FEW HOURS.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE WEAK UPPER LOW WILL HAVE MOVED AWAY BY MON MORNING AND WITH HIGH
PRESSURE STARTING TO MOVE TOWARD THE AREA...A BETTER WEATHER DAY IS
EXPECTED. THERE WILL BE SOME FOG EARLY...BUT DRIER AIR ALOFT WILL
LEAD TO AT LEAST PARTLY SUNNY SKIES BY AFTERNOON. SCT SHOWERS WILL
PROBABLY DEVELOP DURING THE AFTERNOON...BUT COVERAGE WILL NOT BE AS
WIDESPREAD AS THE PAST FEW DAYS. TEMPERATURES WILL JUMP BACK TO
NORMAL LEVELS WITH MOSTLY MID 80S ACROSS THE AREA. WINDS WILL BE
WRLY/NWRLY AT 5 TO 10 MPH.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
LARGE-SCALE PATTERN WILL FEATURE A PERSISTENT TROUGH OVER THE ERN
CONUS THRU MUCH OF THE WEEK. SEVERAL SHORTWAVE DISTURBANCES ROTATING
AROUND THE MAIN TROUGH WILL PROVIDE THE CHANCE OF SHOWERS AND
THUNDERSTORMS THRU MIDWEEK, PARTICULARLY ON WEDNESDAY WHEN A COLD
FRONT MOVES THRU THE CWA. ALSO, DO NOT EXPECT ANY HEATWAVES TO OCCUR
ACROSS OUR REGION UNDER THIS SETUP. TEMPS WILL BE NEAR NORMAL
THROUGHOUT THE LONG-TERM PERIOD. THE WARMEST DAY EXPECTED IN THE
PERIOD IS TUESDAY, BUT MAX TEMPS IN THE MU 80S (PERHAPS REACHING
90F IN A FEW SPOTS) AND MIN TEMPS IN THE MU 60S MONDAY NIGHT AND
TUESDAY NIGHT WOULD ONLY BE AT OR A COUPLE OF DEGREES ABOVE NORMAL
FOR EARLY AUGUST.
MONDAY NIGHT SHOULD BE DRY ACROSS MOST OF THE REGION. TROPICAL STORM
BERTHA IS EXPECTED TO INTERACT WITH THE STALLED OFFSHORE BOUNDARY AS
IT TRACKS EAST OF THE OUTERBANKS. CANNOT RULE OUT A FEW SHOWERS ON
THE NRN PERIPHERY OF THE SYSTEM REACHING THE DELMARVA.
BERTHA IS FORECAST BY THE NATIONAL HURRICANE CENTER TO RE-CURVE TO
THE NORTHEAST TUESDAY AND TUESDAY NIGHT, WITH A TRACK THAT IS WELL
EAST OF THE DELMARVA/NJ COAST. MODEST LIFT PROVIDED BY AN UPSTREAM
SHORTWAVE TROUGH MAY YIELD ISO TO SCT SHOWERS/TSTMS ON TUESDAY.
CONFINED LOW CHANCE POPS TO THE SOUTHERN TIER OF THE CWA, WHERE
DIFFERENTIAL HEATING MAY PROVIDE A FOCUS FOR DIURNAL CONVECTION ON
THE NWRN PERIPHERY OF THE TROPICAL SYSTEM AND ALSO IN THE POCONOS,
WHERE CONVECTION COULD INITIATE OVER THE HIGHER TERRAIN.
A BETTER CHANCE FOR SHOWERS AND STORMS EXPECTED ON WEDNESDAY WHEN A
COLD FRONT MOVES THRU THE AREA. LATEST TREND IN THE FCST WAS TO
RAISE POPS A BIT TO 40-50 PERCENT SINCE THERE IS BETTER MODEL
AGREEMENT REGARDING THE POSITION/TIMING OF THE COLD FRONT, ULVL JET
STREAK AND THE UPPER SHORTWAVE TROUGH. IT APPEARS THAT FAVORABLE
DYNAMICS FROM THESE FEATURES WILL BECOME JUXTAPOSED OVER THE CWA FOR
A PERIOD WEDNESDAY AFTERNOON.
THE FRONT IS FORECAST TO GRADUALLY SHIFT SOUTH OF THE AREA WEDNESDAY
NIGHT BEFORE STALLING SOMEWHERE NEAR THE NC-VA BORDER LATE IN THE
WEEK. ISO SHOWERS POSSIBLE IN EXTREME NERN PA/NRN NJ THURSDAY
AFTERNOON AS COLD POOL ASSOCIATED WITH A TROUGH ALOFT PROVIDES SOME
INSTABILITY. CONVECTION WOULD BE MAINLY DIURNALLY-DRIVEN, LOW-TOPPED
AND ANY COVERAGE OF SHOWERS/STORMS SHOULD BE LOW.
MODEL SPREAD DOES INCREASE LATE IN THE PERIOD, PARTICULARLY THIS
WEEKEND IN REGARDS TO THE POSITION OF THE BOUNDARY AND THE
DEVELOPMENT OF LOPRES ALONG THAT BOUNDARY. ATTM...KEPT THE FCST
NEXT WEEKEND DRY, BUT IF MODELS CONTINUE TO TREND FARTHER
NORTHWARD, PRECIP CHANCES MAY NEED TO BE ADDED, ESPECIALLY ACROSS
THE SRN TIER.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
CONDITIONS AT MOST TAF SITES HAVE BEEN BOUNCING AROUND BETWEEN MVFR
AND VFRR THROUGH THE EVENING WITH KMIV AND KACY HAVE BEEN MORE
CONSTANTLY MVFR. THIS IS EXPECTED TO CONTINUE FOR THE NEXT FEW
HOURS. INDICATIONS ARE MIXED FOR THE OVERNIGHT WITH HOW QUICKLY
THE VISIBILITIES WILL LOWER TO LIFR DUE TO POTENTIAL FOG/LOW CLOUD
DEVELOPMENT AT KMIV AND KACY. TO REFLECT SOME UNCERTAINTY TEMPO
GROUPS WERE USED TO SHOW THE POTENTIAL TIME RANGE OF LIFR
CEILINGS. ELSEWHERE VISIBILITIES WILL BE SLOWER TO DROP AND THE
POTENTIAL FOR LIFR CONDITIONS IS MORE UNCERTAIN, TEMPO GROUPS WERE
HERE AS WELL WITH SOME POTENTIAL TO REMAIN AT MVFR OVERNIGHT.
MONDAY...AFTER THE FOG/LOW CLOUDS BURNS OFF BETWEEN 12-14Z...VFR
EXPECTED WITH WEST/NORTHWEST WINDS AROUND 10 KTS BY NOON POSSIBLY
BECOMING MORE SOUTHWEST.
OUTLOOK...
MONDAY NIGHT AND TUESDAY...PREDOMINATELY VFR WITH LOW CHANCE FOR
SHRA/TSRA MAINLY SOUTH OF PHILA TERMINALS. LIGHT WINDS DURING THE
PERIOD.
TUESDAY NIGHT AND WEDNESDAY...COLD FRONT APPROACHES TUESDAY NIGHT.
CHANCE FOR SHRA/TSRA WITH HIGHEST COVERAGE OF CONVECTION EXPECTED
WEDNESDAY AFTERNOON AS THE COLD FRONT MOVES THRU. MAINLY VFR BUT
LOCAL/TEMPORARY FLIGHT RESTRICTIONS WOULD BE ANTICIPATED IN HEAVIER
ACTIVITY.
WEDNESDAY NIGHT THROUGH FRIDAY...COLD FRONT MOVES SOUTH OF THE
TERMINALS. ATTM, EXPECT A MAINLY DRY PERIOD WITH HIPRES TRYING TO
BUILD IN FROM THE GREAT LAKES.
&&
.MARINE...
RATHER SHOWERY/FOGGY CONDITIONS ACROSS THE WATERS AS A FRONT AND
WAVES OF LOW PRESSURE MOVE ALONG IT. THE FRONT WILL EDGE EASTWARD
TONIGHT BRINGING SCT SHOWERS AND LIGHT WINDS. WIND DIRECTIONS WHICH
HAVE BEEN MOSTLY NE OR E WILL SWITCH MORE WRLY/NWRLY ON MONDAY. SEAS
ON THE OCEAN WILL REMAIN MOSTLY AROUND 3 FT. OVER DEL BAY...SE WINDS
WILL BECOME NW MONDAY WITH SPEEDS 5 TO 10 KTS. AREAS OF FOG ARE
POSSIBLE TONIGHT WITH LOWER VSBYS.
OUTLOOK...
MONDAY NIGHT...NO HAZARDS EXPECTED ON THE WATERS.
TUESDAY THROUGH WEDNESDAY...TROPICAL STORM BERTHA IS EXPECTED TO
TRACK WELL EAST OF THE AREA, BUT IS FORECAST TO PRODUCE WAVES OF
3-4 FT. IF THE TRACK OF BERTHA SHIFTS CLOSER TO THE COAST, LOCALLY
HIGHER WAVES MAY REACH SCA CRITERIA. LONG-PERIOD SWELLS OF 10-13
S ARE CURRENTLY FORECAST FOR TUESDAY AND WEDNESDAY.
WEDNESDAY NIGHT THROUGH FRIDAY...NO MARINE HEADLINES ARE ANTICIPATED.
&&
.RIP CURRENTS...
THERE REMAINS SOME ENHANCED WAVE ACTION ALONG THE COAST THIS
AFTERNOON. CONTINUE TO HIGHLIGHT A MODERATE RISK OF RIP CURRENTS
THROUGH TOMORROW.
LONG PERIOD SWELLS FROM TROPICAL STORM BERTHA MAY AFFECT THE
COASTS OF DELAWARE AND NEW JERSEY FROM LATE MONDAY INTO WEDNESDAY.
THE SWELLS COULD BRING AN ENHANCED THREAT FOR DANGEROUS RIP
CURRENTS DURING THIS TIME.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GAINES/O`HARA
SHORT TERM...O`HARA
LONG TERM...KLEIN
AVIATION...GAINES/KLEIN/O`HARA
MARINE...KLEIN/O`HARA
RIP CURRENTS...GAINES/KLEIN/O`HARA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
624 PM EDT SAT AUG 2 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL REMAIN STALLED JUST OFF THE MID-ATLANTIC
COAST THROUGH THE REMAINDER OF THE WEEKEND. THIS REMNANTS OF THIS
BOUNDARY WILL DISSIPATE ALONG THE EASTERN SEABOARD EARLY NEXT WEEK
BEFORE A COLD FRONT MOVES THROUGH WEDNESDAY. HIGH PRESSURE BUILDS IN
FROM THE GREAT LAKES LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AN UPPER TROUGH REMAIN TO THE WEST OVER THE OHIO VALLEY WHILE A
FRONT/TROUGH REMAIN ALONG THE COASTAL AREAS. A WAVE MOVED ALONG THE
TROUGH THIS MORNING WHICH HELPED PRODUCE THIS MORNINGS SHOWERS
ACROSS THE REGION. WE ARE PRESENTLY BETWEEN SYSTEMS AS ANOTHER WEAK
LOW WILL AFFECT THE REGION TONIGHT INTO EARLY SUNDAY. THE MODELS
DIFFER WITH RESPECT TO THE SYSTEM WITH THE NAM OFFERING GENEROUS QPF
AND HIGH POPS EVERYWHERE...WHILE THE GFS IS LIGHTER WITH THE QPF AND
LESSER WITH THE POPS (MOSTLY CHC). THE EC IS SHOWING COVERAGE LIKE
THE NAM AND HIGHER QPF MORE LIKE THE GFS (CLOSER TO THE COAST). WE
HAVE MOSTLY CONTINUED WITH THE PREVIOUS FCST WITH HIGH POPS
(CATEGORICAL/LIKELY) FOR MOST OF THE ERN HALF OF THE REGION WITH
CHANCE POPS NORTH AND WEST. THE ONSET OF THE HIGHER POPS WERE SLOWED A
BIT BASED ON THE LATEST RAP AND RADAR TRENDS. SKY COVER WAS ALSO
ADJUSTED DOWNWARD FOR THE NEXT FEW HOURS NW OF PHL AS SOME BREAKS
ARE BECOMING MORE PREDOMINANT OVER THE LAST FEW HOURS. TEMPS
MOSTLY MAV/MET MIX WITH LOWS IN THE MID/UPPER 60S S/E AND UPPER
50S TO LOW 60S N/W.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY MAY WELL END UP BEING LIKE SATURDAY...WITH A WEAK WAVE OF LOW
PRESSURE MOVING ALONG THE SHORE DURING THE FIRST PART OF THE
DAY...FOLLOWED BY SLOW IMPROVEMENT LATE. THE UPPER TROUGH TO THE
WEST WHICH WILL BE DIMINISHING...MAY STILL TRIGGER SOME SHOWERS N/W
DURING THE AFTERNOON. WE HAVE HIGHER POPS EARLY THEN DECREASING
THROUGH THE AFTERNOON. TEMPS WILL REMAIN BELOW NORMAL WITH MOSTLY
UPPER 70S/LOW 80S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A MID-LVL SHORTWAVE TROUGH WILL LIFT NEWD THRU PA AND INTO NEW
ENGLAND SUNDAY NIGHT. A FEW SHOWERS AHEAD OF THIS SYSTEM MAY LINGER
INTO THE EARLY EVE BUT ACTIVITY SHOULD BE DIURNALLY DRIVEN...
DISSIPATING WITH THE LOSS OF SOLAR HEATING.
THE REMNANTS OF AN OLD SFC BOUNDARY THAT HAD STALLED NEAR THE
MID-ATLANTIC COAST OVER THE PAST FEW DAYS WILL REMAIN NEARBY EARLY
NEXT WEEK. HOWEVER, MODELS GENERALLY SHOW THE BOUNDARY BECOMING SO
DIFFUSE THAT IT IS DIFFICULT TO DISCERN WHERE THE ASSOCIATED LLVL
LIFT WOULD RESIDE. STILL EXPECT SOME SHOWERS TO INITIATE DURING THE
PEAK HEATING HOURS BOTH MONDAY AND TUESDAY OVER THE HIGHER TERRAIN,
BUT OPTED TO LOWER POPS TO AROUND 20 PERCENT AND MAINLY WEST OF I-95
(EXCEPT 30 PERCENT IN THE POCONOS) OWING TO A LACK OF ORGANIZED
LIFT. ENVIRONMENT MARGINALLY SUPPORTIVE OF THUNDERSTORM CHANCES BOTH
DAYS UNDER WEAK MID-LVL LAPSE RATES AND LIMITED INSTABILITY.
POSITIVELY-TILTED TROUGH WILL AMPLIFY UPSTREAM OVER GREAT LAKES/
MIDWEST/ERN CANADA TOWARD MIDWEEK. HEIGHT FALL AHEAD OF THIS TROUGH
WILL OCCUR IN CONJUNCTION WITH A STRENGTHENING COLD FRONT NEAR THE
EASTERN SEABOARD LATE TUESDAY NIGHT INTO WEDNESDAY. CHANCES FOR
SHOWERS AND STORMS AS THE FRONT PUSHES THRU.
12Z OPERATIONAL ECMWF/GFS/CANADIAN MODELS IN REASONABLE AGREEMENT
WITH THE COLD FRONT PROGRESSING SOUTH AND EAST OF THE AREA BY
THURSDAY. HIGH PRESSURE BUILDS IN FROM THE GREAT LAKES IN ITS
WAKE. THIS PATTERN FAVORS DRY CONDITIONS TO LATE IN THE WEEK.
TEMPS LOOK TO BE CLOSE TO CLIMO EARLY IN THE WEEK AND PERHAPS A
FEW DEGREES BELOW CLIMO MID TO LATE PART OF THE WEEK. MAX TEMPS
GENERALLY IN THE MU80S MON-TUE AND LM 80S WED-FRI.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THE LOW PRESSURE SYSTEM THAT AFFECTED THE REGION EARLIER TODAY HAS
MOVED OFFSHORE. ABUNDANT LOW LEVEL MOISTURE REMAINS ACROSS THE
REGION...SO MOSTLY MVFR CIGS ARE BEING OBSERVED ACROSS THE AREA.
CONDITIONS AT KACY ARE STILL IFR...AND AT THE OTHER END...VFR
CONDITIONS ARE BEING OBSERVED AT KRDG AND KABE. NOT MUCH WILL CHANGE
THE REST OF THE AFTERNOON WITH A MODEST NE FLOW AT THE LOW LEVELS
CONTINUING INTO THE EARLY EVENING. I DO EXPECT THAT CONDITIONS WILL
BECOME VFR ACROSS THE DEL VALLEY BEFORE EVENING...AND LAST INTO THE
EVENING. KACY AND KMIV WILL LIKELY REMAIN MVFR TONIGHT BEFORE THE
NEXT SYSTEM ARRIVES.
ANOTHER WAVE WILL MOVE UP ALONG THE COAST TONIGHT AND CIGS/VSBYS
WILL DECREASE AGAIN LATER TONIGHT AND PERSIST INTO SUNDAY MORNING.
THE MET/MAV GUIDANCE OFFER WIDELY DIFFERING SOLUTIONS FOR THE
PERIOD...SO I MOSTLY COMBINED THE TWO AND MIXED IN SOME CONSENSUS TO
COME UP WITH THE 18Z TAFS. SLOW IMPROVEMENT SUNDAY...LOW CONFID IN
THE TIMING HOWEVER.
OUTLOOK...
SUNDAY NIGHT THROUGH TUESDAY...A FEW SHRA AND PERHAPS AN ISO TSTM
DURING THE AFTN/EVE HRS EACH DAY, PRIMARILY WEST OF PHL AREA
TERMINALS. MAINLY VFR. LGT WINDS PREDOMINATELY OUT OF THE SOUTH.
TUESDAY NIGHT AND WEDNESDAY...CHANCE FOR SHRA/TSRA INCREASE AHEAD OF
A COLD FRONT. BRIEF FLIGHT RESTRICTIONS POSSIBLE IN HEAVIER
ACTIVITY. OTHERWISE VFR.
THURSDAY...VFR WITH HIPRES BUILDING IN.
&&
.MARINE...
THE PREVAILING WINDS ALONG THE NRN NJ COASTAL WATERS WERE 15 TO 20
KNOTS WITH SOME SCA GUSTS EARLIER. SEAS MOSTLY 4 - 5 FT. THE LATEST
OBS SHOW THE BEGINNINGS OF WHAT IS EXPECTED TO BE LIGHTER WINDS AND
DIMINISHING SEAS FOR THE OVERNIGHT PERIOD. WE WILL TAKE THE SCA FLAG
DOWN WITH THE 330 PM FORECAST. SCT SHOWERS INTO THE EARLY EVENING
THEN MORE SHOWERS MOVING FROM S TO N AROUND DAWN.
OUTLOOK...
SUNDAY NIGHT THROUGH THURSDAY...NO MARINE HEADLINES EXPECTED WITH
LIGHT WINDS. BEST CHANCES FOR THUNDERSTORMS IN THIS PERIOD WILL BE
WEDNESDAY.
&&
.RIP CURRENTS...
LONG PERIOD SWELLS FROM TROPICAL STORM BERTHA MAY AFFECT THE
COASTS OF DELAWARE AND NEW JERSEY PERHAPS AS EARLY AS LATE MONDAY.
AND CONTINUE TUESDAY INTO WEDNESDAY. THESE SWELLS WOULD BRING AN
ENHANCED THREAT FOR DANGEROUS RIP CURRENTS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KLEIN
NEAR TERM...GAINES/O`HARA
SHORT TERM...O`HARA
LONG TERM...KLEIN
AVIATION...KLEIN/O`HARA
MARINE...KLEIN/O`HARA
RIP CURRENTS...KLEIN
AREA FORECAST DISCUSSION
NWS MIAMI FL
731 PM EDT SUN AUG 3 2014
.AVIATION...
CONVECTION GOT A LATE START THIS AFTERNOON DUE TO RAIN-COOLED
AIRMASS ALONG EAST COAST DELAYING ACTIVITY SO PERSISTING UNTIL
AROUND 02Z THIS EVENING AND WILL LIKELY REDEVELOP AFT 14Z MONDAY.
SURFACE WIND WILL BECOME LIGHT SW EARLY THIS EVENING WITH THE
TROUGH MOVING NORTH OF THE REGION BY LATE MONDAY. THIS WILL
PREVENT AN EAST COAST SEA BREEZE WITH NUMEROUS TSRA EXPECTED WELL
INTO THE AFTERNOON.
KOB
&&
.PREV DISCUSSION... /ISSUED 252 PM EDT SUN AUG 3 2014/
NEAR TERM...(THIS AFTERNOON)
THE HEAVY LINE OF SHOWERS/TSTMS THAT MOVED ASHORE EARLY THIS
AFTERNOON HAS WEAKENED AND DISSIPATED...MAINLY DUE TO THE MORE
STABLE EAST COAST WHERE TEMPERATURES HAVE REMAINED STEADY IN THE
LOWER 80S FROM THE EXTENSIVE CLOUD COVERAGE ASSOCIATED WITH THE
OFFSHORE CONVECTION EARLIER. FARTHER INLAND...ADDITIONAL SHOWERS
HAVE BEGUN TO DEVELOP WHERE A BETTER SOURCE OF INSTABILITY EXISTS
(TEMPERATURES HAVE ALREADY REACHED THE UPPER 80S TO 90 DEG RANGE).
THE LATEST HRRR HAS PICKED UP ON THESE TRENDS AND HAS BACKED OFF
ON THE EARLIER SUGGESTED EAST COAST ACTIVITY LATER THIS
AFTERNOON/EARLY EVENING SHOWING MOSTLY STRATIFIED PRECIP FOR THE
SE FL COAST (OR LIGHT RAIN WITH EMBEDDED HEAVIER SHOWERS/TSTMS
ALONG THE EAST COAST) THROUGH THE AFTERNOON HOURS. HOWEVER...THE
LAKE REGION INCLUDING PALM BEACH COUNTY COULD OBSERVE SOME
HEAVIER AFTERNOON SHOWERS/TSTMS.
SHORT TERM...(TONIGHT-TUESDAY NIGHT)
THE LATEST SHORT-RANGE MODEL GUIDANCE REMAINS CONSISTENT FROM CYCLE
TO CYCLE AND INDICATES THE WET PATTERN PERSISTING INTO THE UPCOMING
WEEK AS A SURFACE TROUGH OF LOW PRESSURE AND UPPER TROUGH CONTINUE
TO INFLUENCE THE LOCAL WEATHER PATTERN. AN ASCAT PASS THIS
AFTERNOON SHOWED TS BERTHA CENTERED NEAR THE SOUTHEASTERN BAHAMA
ISLANDS. THE LATEST ADVISORY INDICATES BERTHA TURNING NORTHWARD
AND REMAINING JUST EAST OF THE BAHAMAS THROUGH MONDAY AS IT PASSES
(SHOULD NOT HAVE ANY DIRECT IMPACT ON THE LOCAL AREA). THE LATEST
GUIDANCE INDICATES THE SFC TROUGH OVERHEAD THAT IS IMPACTING THE
LOCAL WEATHER SLOWLY LIFTING NWD INTO MONDAY...WHICH WILL
TRANSLATE TO SW LOW-LEVEL FLOW WITH THE RIDGE AXIS ORIENTED E-W
SOUTH OF THE AREA OVER THE STRAITS. THIS LOW-LEVEL FLOW COMBINED
WITH THE AFOREMENTIONED DEEP LAYER MOISTURE (MODEL PWAT VALUES
RANGING FROM 2- 2.3" MONDAY-TUESDAY EVENING) COULD TRANSLATE TO A
POTENTIAL HEAVY RAINFALL/FLOODING CONCERN OVER PORTIONS OF THE
LOCAL AREA PERIODICALLY...ESPECIALLY WITH THE RECENT ACTIVITY AND
THE ALREADY SATURATED GROUNDS. THE LATEST RAINFALL ACCUMULATION
PROJECTION INDICATES 1.5 TO 2.5" WIDESPREAD AMOUNTS. MUCH HIGHER
LOCALIZED AMOUNTS WHERE ANY ACTIVITY BECOMES FOCUSED FOR A PERIOD
OF TIME WILL REMAIN POSSIBLE EACH DAY. THE SURFACE FLOW IS
PROJECTED TO REMAIN LIGHT ENOUGH FOR AN EAST COAST SEA BREEZE TO
DEVELOP EACH DAY...WHICH TYPICALLY RESULTS IN THE AFTERNOON
CONVECTION SETTING UP AND FAVORING THE EAST COAST.
HOWEVER...SIMILAR TO TODAY...STABILITY COULD PLAY A ROLE HERE AND
END UP REDUCING THE OVERALL HEAVY RAIN/FLOODING CONCERNS...IF THE
OVERCAST AND RELATIVELY COOL CONDITIONS ARE REALIZED THROUGH THE
AFTERNOON PERIODS AGAIN MONDAY AND TUESDAY.
LONG TERM (WEDNESDAY-WEEKEND)...
THE LATEST EXTENDED GUIDANCE CONTINUES TO SUGGEST A RETURN OF A MORE
TYPICAL SUMMER-LIKE PATTERN ACROSS THE REGION THROUGH THE SECOND
HALF OF THE WEEK AND INTO THE WEEKEND AS A DEEP LAYER RIDGE BUILDS
BACK OVERHEAD. AT THIS TIME...IT APPEARS WEDNESDAY COULD BE THE
TRANSITION DAY...WHICH WOULD MEAN ANOTHER WET AFTERNOON WITH A
SUFFICIENT AMOUNT OF DEEP LAYER MOISTURE AND LIGHT SW LOW-LEVEL FLOW
TO FOCUS THE AFTERNOON ACTIVITY TOWARD THE EAST COAST.
AVIATION...
MOST OF THE CONVECTION HAS DISSIPATED ACROSS THE NEAR
SHORE ATLANTIC WATERS THIS AFTERNOON AFTER ENCOUNTERING A MORE
STABLE AIR MASS. ONLY AREAS OF LIGHT TO MODERATE SHOWERS REMAIN
WHICH SHOULD BE COVERED WELL WITH VCSH. LATEST HRRR KEEPS SHOWERS
ACROSS THE EAST COAST THROUGH THE EARLY EVENING WITH CONTINUED
SOUTHEAST TO SOUTHERLY WINDS. ANY REMAINING CONVECTION SHOULD STAY
ACROSS THE INTERIOR POSSIBLY AFFECTING KAPF. LEFT VCTS MENTION
THERE UNTIL 01Z.
MARINE...
TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH
FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE
TONIGHT THROUGH MONDAY. WINDS ARE FORECAST TO REMAIN LIGHT AND SHIFT
TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK. SCATTERED
SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER
CONDITIONS EACH DAY ALONG WITH REDUCED VISIBILITIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 90 77 92 / 50 70 40 60
FORT LAUDERDALE 77 90 80 92 / 50 70 40 50
MIAMI 77 90 79 91 / 50 70 40 50
NAPLES 77 90 76 91 / 30 50 60 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
415 AM EDT SAT AUG 2 2014
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN UPPER LEVEL PATTERN
CONSISTING OF LONGWAVE RIDGING OVER THE PACIFIC COAST/INTER-MOUNTAIN
WEST...FOLLOWED DOWNSTREAM BY PERSISTENT LONGWAVE TROUGHING OVER THE
EASTERN HALF OF THE NATION. FLORIDA IS JUST ABOUT THE ONLY PLACE IN
THE EAST TO NOT BE UNDER THIS TROUGH...AS A WEAK "SLIVER" OF RIDGING
REMAINS OVERHEAD...EXTENDING TO THE SOUTHWEST FROM THE MAIN RIDGE
CENTER OVER THE WESTERN ATLANTIC. WV IMAGERY SHOWS PLENTY OF
MID/UPPER LEVEL MOISTURE IN PLACE OVER THE REGION AND THIS WAS
EVIDENT IN THE 02/00Z KTBW SOUNDING PROFILE WHICH SHOWED NO
SIGNIFICANT LAYERS OF DRY AIR THROUGH THE COLUMN. PW VALUES ARE
ALREADY A TOUCH ON THE HIGH SIDE...CALCULATED AT NEAR 2" THIS PAST
EVENING...AND LATEST NWP GUIDANCE SUGGESTS THIS VALUES SHOULD CREEP
UP EVEN HIGHER DURING THE NEXT COUPLE OF DAYS.
AT THE SURFACE...A WEAK GRADIENT AND VERY LIGHT SYNOPTIC FLOW IN
PLACE ACROSS THE REGION. FORECAST AREA RESIDES AT THE BASE OF AN
INVERTED TROUGH ALONG THE EASTERN SEABOARD. THIS TROUGH IS QUITE
ILL-DEFINED THIS FAR SOUTH...BUT WILL RESULT IN A WEAK EASTERLY
1000-700MB MEAN FLOW FOR THE AFTERNOON/EVENING HOURS AWAY FROM THE
IMMEDIATE COAST WHERE THE DEVELOPING SEA-BREEZE WILL COMPLICATE
THINGS. REGIONAL RADARS ARE FAIRLY CLEAR EARLY THIS MORNING...
ALTHOUGH WOULD EXPECT A FEW ISOLATED CELLS TO DEVELOP BETWEEN NOW
AND SUNRISE OVER THE COASTAL WATERS...ESPECIALLY TO THE SOUTH OF
TAMPA BAY. EITHER WAY...THINGS SHOULD BE ON THE QUIET SIDE UNTIL THE
LATER MORNING/EARLY AFTERNOON HOURS.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY...
AS MENTIONED IN THE SYNOPSIS...REGION WILL REMAIN UNDER A WEAK
MID/UPPER LEVEL RIDGE...ABOVE A WEAK INVERTED SURFACE TROUGH. THE
MORNING SHOULD BE ON THE QUIET SIDE AS WE HEAT UP THROUGH THE 80S.
LOOKING AT EVERYTHING AVAILABLE...CAN NOT SEE WHY THIS AFTERNOON
WOULD NOT BE FAIRLY ACTIVE IN TERMS OF STORMS...AS THE ATMOSPHERIC
COLUMN IS FAVORABLE TO SUPPORT DEEP CONVECTION. MINIMUM THETA-E
VALUES ALOFT ARE JUST SHY OF 330K...WHICH IS NEAR OR SLIGHTLY ABOVE
CLIMO. WE DO NOT LOOK FOR AN ATMOSPHERE BECOMING HOSTILE TO DEEP
CONVECTION UNTIL THESE VALUES DROP DOWN TOWARD 320K. THE BIGGEST
QUESTION WILL BE JUST WHERE THE BEST SURFACE CONVERGENCE/LOW LEVEL
FOCUS FOR ASCENT DEVELOPS.
EARLY IN THE AFTERNOON...THE VERY LIGHT GRADIENT WILL ALLOW THE
SEA-BREEZE TO DEVELOP AND BEGIN SLOWLY MOVING INLAND. THIS PATTERN
WOULD SUGGEST THE FIRST STORMS OF THE DAY MAY BE OVER PINELLAS
COUNTY ASSOCIATED WITH THE FIRST COLLISIONS BETWEEN THE GULF AND
TAMPA BAY BREEZES. IN FACT THE LAST 3 RUNS OF THE LOCAL HIRES WRFARW
HAVE ALL PRODUCED A STORM OVER PINELLAS COUNTY AROUND 17-18Z. WHILE
IT IS HIGHLY IMPROPER TO EVER SUGGEST ANY NWP GUIDANCE AS GROUND
TRUTH (ESPECIALLY AN EXPLICIT CONVECTION SOLUTION)...IT IS
CURIOUS THAT SEVERAL DIFFERENT GUIDANCE MEMBERS WITH DIFFERENT
PHYSICS PACKAGES ALL PIN THIS SAME AREA AT ROUGHLY THE SAME TIME.
WILL BE INTERESTING TO SEE IF IT VERIFIES. THEREAFTER...FOR THE
SECOND HALF OF THE AFTERNOON AND EARLY EVENING HOURS...HIGHEST
CHANCES FOR STORMS LOOK TO SET UP NEAR AND JUST EAST OF THE I-75
CORRIDOR WHERE THE GULF SEABREEZE AND LIGHT SYNOPTIC FLOW MEET.
ALTHOUGH THIS IS THE SWATH THAT SEEMS TO BE MOST LIKELY FOR
STORMS...THE SYNOPTIC INVERTED SURFACE TROUGH WOULD SUGGEST WEAK
FOCUS FOR ASCENT OVER MUCH OF THE AREA...SO AT LEAST CLIMO POPS WILL
NEED TO BE FORECAST FOR AREA OUTSIDE THE FAVORED I-75 ZONE.
INITIALLY AFTER EARLY AFTERNOON AS THE SEA-BREEZE MOVES INLAND A
BIT...WE SHOULD SEE A PERIOD OF DECREASED RAIN CHANCES AT THE
BEACHES. WILL THIS LAST THE REST OF THE DAY OR WILL STORMS COME BACK
WESTWARD LATE IN THE DAY ONCE AGAIN? GOOD QUESTION. DEEP LAYER STORM
MOTION IN THE ATMOSPHERE IS VIRTUALLY NONE EXISTENT. SO...ANY STORMS
THAT DO DEVELOP ARE LIKELY TO BE VERY SLOW MOVING. THE SEA-BREEZE
WILL NOT BE ALL THAT STRONG AND SO ANY STRONGER OUTFLOW BOUNDARY MAY
BE ABLE TO FIGHT ITS WAY WESTWARD BACK TO THE COAST AND KICK OFF NEW
STORMS LATE IN THE DAY. WILL NOT BRING THE LIKELY RAIN CHANCES ALL
THE WAY BACK TO THE BEACHES AT THIS TIME...BUT KEEP A CHANCE POP IN
THE GRIDS IN ANTICIPATION OF SOME WESTWARD PROPAGATING OUTFLOW
BOUNDARIES. BEST CHANCES FOR STORMS ALL THE WAY TO THE COAST LATER
IN THE DAY WILL BE DOWN TOWARD CHARLOTTE HARBOR WHERE THE EASTERLY
SYNOPTIC FLOW WILL BE A BIT MORE DEFINED.
A BIT CONCERNED ABOUT THE POTENTIAL FOR SOME LOCALLY VERY HEAVY
RAINFALL LATER TODAY. THE SLOW STORM MOTION GIVEN THE LACK OF DEEP
LAYER FLOW AND MOIST ATMOSPHERE SUGGEST A FEW STORMS WILL BE ABLE TO
REALLY DRENCH THE LOCATIONS THEY ARE OVER. CAN NOT RULE OUT A FEW
DAMAGING WIND GUSTS AS WELL. GFS/NAM BOTH SUGGEST THE DIFFERENCE
BETWEEN THE MINIMUM THETA-E VALUES ALOFT AND SURFACE VALUES WILL RUN
BETWEEN 20-25K THIS AFTERNOON. STUDIES ACROSS THE SOUTHEASTERN
STATES HAVE FOUND VALUES OVER 20K ARE FAVORABLE FOR THE FORMATION OF
WET MICROBURSTS. THE ABUNDANT COLUMN MOISTURE AND SLOW MOVEMENT
WOULD ALSO SUGGEST THE POTENTIAL FOR SUBSTANTIAL PRECIPITATION
LOADING OF THE STRONGER CELLS...LEADING TO WIND GUST POTENTIAL UPON
CONVECTIVE COLUMN COLLAPSE.
SUNDAY...
THE SECOND HALF OF THE WEEKEND LOOKS POTENTIALLY EVEN MORE
CONVECTIVELY ACTIVE. HAVE FAVORED THE GFS/ECMWF SOLUTIONS FOR SUNDAY
COMPARED TO THE NAM/SREF ENSEMBLES. THE NAM/SREF SEEM A BIT
AGGRESSIVE WITH THE ORGANIZATION OF THE SURFACE TROUGH...AND CLOSE
OFF A DEFINED CIRCULATION ALONG THE EAST COAST. THE GFS/ECMWF ARE
WEAKER WITH THIS FEATURE AND WOULD SEEM MORE REALISTIC GIVEN THE
LACK OF SYNOPTIC SUPPORT FROM ALOFT.
THE GFS/ECMWF ALIGN THE TROUGHING DOWN THE SPINE OF THE PENINSULA
WHICH RESULTS IN VERY ILL-DEFINED SYNOPTIC FLOW. THEREFORE...NEITHER
THE EAST OR WEST COAST SEA-BREEZE IS LIKELY TO BE DOMINANT. BEST
FOCUS FOR ASCENT DURING THE AFTERNOON SHOULD BE ALONG AND EAST OF
THE I-75 CORRIDOR BETTER ALIGNED WITH THE FOCUS ASSOCIATED WITH THE
TROUGH AXIS. PW VALUES ARE FORECAST BY THE GFS TO APPROACH 2.2"
ACROSS MUCH OF THE REGION...AND WILL HIGHLY SUPPORT DEEP CONVECTION.
HAVE 70-75% RAIN CHANCES OVER THE FAVORED ZONE MENTIONED ABOVE WITH
RAIN CHANCES DECREASING TO 40-50% AT THE BEACHES. ONCE AGAIN THE
THREAT FOR HEAVY RAINFALL IS THERE AS THE STORM MOTION WILL BE VERY
SLOW...AND THE COLUMN WILL SUPPORT SOME VERY HEAVY PRECIPITATION
RATES WITH THE STRONGER STORMS.
IN TERMS OF TEMPERATURES...HAVE GONE A FEW DEGREES BELOW THE MAV
NUMBERS AND CAPPED HIGH TEMPS IN THE LOWER 90S. ANTICIPATED
CONVECTIVE COVERAGE...ALONG AND EARLIER INITIATION...AND RESULTING
CIRRUS CANOPY LATER IN THE DAY SUGGEST WIDESPREAD MIDDLE 90S ARE
UNLIKELY. HAVE A GREAT START TO YOUR WEEKEND!
&&
.LONG TERM (SUNDAY NIGHT THROUGH NEXT FRIDAY)...
THE FIRST HALF OF NEXT WEEK WILL BE DOMINATED BY AN UPPER TROUGH
OVER THE EASTERN U.S. A FRONTAL BOUNDARY/TROUGH RESIDES ALONG THE
GULF COAST WITH A RATHER RELAXED SURFACE PRESSURE PATTERN ACROSS
THE GULF AS THE LATEST NHC TRACK MOVES BERTHA NORTH THEN NE ACROSS
THE OPEN ATLANTIC WATERS. BEGINNING MID-WEEK...AS BERTHA IS FORECAST
TO CONTINUE MOVING AWAY...DEEP LAYER RIDGING BUILDS ACROSS SOUTHERN
FL AND LIFTS INTO CENTRAL OR NORTH-CENTRAL FL BY WEEKS END.
EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS MON AND TUE
THAT TREND DOWN TO ISOLATED TO SCATTERED...IN THE LOW TO MID
RANGE...TOWARD THE END OF THE WEEK AS THE DEEP LAYER RIDGING BEGINS
TO TAKE CONTROL. TEMPERATURES INITIALLY NEAR NORMAL OR JUST BELOW
WILL WARM TO SLIGHTLY ABOVE THROUGH THE PERIOD. LOW LEVEL FLOW WILL
BE LIGHT WITH AFTERNOON SEA BREEZES ALTHOUGH A MORE EAST TO SE
COMPONENT WILL BEGIN TO SPREAD INTO THE AREA BY THE END OF THE
WEEK.
&&
.AVIATION...
VFR CONDITIONS PREVAILING ACROSS THE REGION EARLY THIS MORNING AS
HIGH LEVEL CIRRUS CANOPY CONTINUES TO FADE. STORMS LOOK ACTIVE LATER
TODAY ALONG THE I-75 CORRIDOR WHICH WILL IMPACT MOST OF THE TAF
SITES. LATE IN THE DAY KPIE/KTPA LOOK TO BE ON THE WESTERN EDGE OF
THIS ACTIVITY...BUT ARE STILL EXPECTED TO BE CLOSE ENOUGH TO INCLUDE
VCTS MENTION. STORMS WILL BE VERY SLOW MOVING RESULTING IN POTENTIAL
FOR MORE EXTENDED PERIODS OF RESTRICTION AS THE PASS OVER A TERMINAL.
&&
.MARINE...
A WEAK GRADIENT WILL KEEP WINDS AND SEAS ON THE LOW SIDE THROUGH THE
WEEKEND. WILL SEE SEA-BREEZE DEVELOPING TURNING WINDS ONSHORE NEAR
THE COAST UP TO AROUND 10 KNOTS EACH AFTERNOON...WITH WINDS THEN
BECOMING LIGHT OFFSHORE WITHIN A FEW HOURS OF SUNSET EACH EVENING.
LOOK FOR A SCATTERING OF STORMS DEVELOPING EARLY SUNDAY MORNING OVER
THE NEARSHORE WATERS.
&&
.FIRE WEATHER...
RELATIVE HUMIDITY WILL REMAIN WELL ABOVE CRITICAL LEVELS THE NEXT
SEVERAL DAYS ALONG WITH HIGH RAIN CHANCES AWAY FROM THE IMMEDIATE
COAST. WINDS WILL TURN ONSHORE NEAR THE COAST EACH AFTERNOON WITH
THE SEA-BREEZE...HOWEVER INLAND...SURFACE WINDS WILL REMAIN RATHER
LIGHT AND VARIABLE. IN ADDITION...TRANSPORT WINDS WILL BE QUITE
LIGHT AND VARIABLE. NO SIGNIFICANT AREAS OF FOG ARE EXPECTED THROUGH
THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 91 78 91 79 / 60 40 60 40
FMY 92 76 91 78 / 60 30 70 50
GIF 94 76 92 77 / 60 30 70 50
SRQ 90 77 90 77 / 40 40 40 30
BKV 94 73 92 73 / 60 40 70 40
SPG 91 80 91 81 / 50 40 40 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM...RUDE
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1047 PM EDT SUN AUG 3 2014
.SYNOPSIS...
A STATIONARY FRONTAL BOUNDARY ALONG THE COAST WILL LINGER THROUGH
MONDAY. A LOW PRESSURE AREA WILL MOVE NORTHEAST ALONG THE BOUNDARY
TONIGHT AND MONDAY BRINGING THE THREAT FOR SHOWERS ESPECIALLY
CLOSER TO THE COAST. DRIER AIR WILL ENTER THE REGION FROM THE WEST
TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CONVERGENCE AND MOISTURE ASSOCIATED WITH THE TROUGH NEAR THE COAST
SHOULD STAY MAINLY EAST OF THE FORECAST AREA TONIGHT. THE NAM WAS
MORE PRONOUNCED PUSHING DEEPER MOISTURE INLAND LATE. THE LATEST
HRRR DISPLAYS LITTLE COVERAGE THROUGH TONIGHT. WE MAINTAINED THE
LOW-POP FORECAST. HIGH LOW-LEVEL MOISTURE IN THE EASTERLY FLOW
PLUS DIURNAL COOLING WILL LIKELY HELP SUPPORT WIDESPREAD STRATUS
TOWARD MORNING. THE TEMPERATURE GUIDANCE WAS CLOSE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
UPPER TROUGH AXIS WILL REMAIN TO OUR WEST MONDAY. UPPER ENERGY MOVING
NORTH AROUND THE BACK SIDE OF 500MB HIGH OVER THE ATLANTIC EXPECTED
TO BRING A WAVE OF LOW PRESSURE UP FROM FLORIDA TOWARDS THE SC
COAST MONDAY. ABUNDANT MOISTURE WILL BE AVAILABLE NEAR THE COASTAL
PLAIN...WITH LOW LEVEL EASTERLY FLOW NORTH OF THE LOW INCREASING
MOISTURE FURTHER INLAND INTO OUR EASTERN FA.
MODELS IN FAIR AGREEMENT SHIFTING UPPER TROUGH AXIS EAST TOWARDS
OUR REGION TUESDAY...WITH SURFACE LOW TRACKING NE UP THE EAST
COAST...AND PROVIDING FOR SOME DRIER AIR TO ENTER OUR REGION FROM
THE WEST. POPS WILL DECREASE WITH A RETURN TO SCATTERED DIURNAL
CONVECTION ESPECIALLY OVER THE EASTERN FORECAST AREA WHERE THE
BETTER MOISTURE WILL BE.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
500MB TROUGH AXIS OVER THE GREAT LAKES REGION EARLY IN THE PERIOD
SHIFTS EAST TO NEW ENGLAND BY FRIDAY. SURFACE HIGH PRESSURE MOVING
EAST ACROSS THE MIDWEST WILL PUSH A WEAK COLD FRONT SOUTH EAST
ACROSS THE FORECAST AREA FRIDAY. LOW CHANCE POPS WEDNESDAY AND
THURSDAY...WITH CHANCE POPS FRIDAY INTO SATURDAY WITH FRONT IN
THE AREA. DAYTIME HIGHS PUSHING 90 DEGREES EACH DAY...WITH
OVERNIGHT LOWS AROUND 70 EARLY IN THE PERIOD...MODERATING TO THE
MID OR UPPER 70S BY LATE WEEK.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
CEILINGS ACROSS THE REGION VFR. A FEW LIGHT SHOWERS POSSIBLE
OVERNIGHT MAINLY ACROSS THE EAST MIDLANDS NEAR OGB. CEILINGS LATER
TONIGHT ARE EXPECTED TO DROP BACK DOWN INTO THE IFR/LIFR RANGE
AFTER 06Z. THIS IS SUPPORTED BY LATEST HRRR BUT LACK OF SUPPORT
FROM SREF AND LAMP SUGGEST MORE UNCERTAINTY. LOW LEVEL FLOW
APPEARS MORE NORTH-NORTHEAST BUT OVERALL ONSHORE FLOW
CONTINUES...NAM APPEARS STRONGER.
MODELS BEGIN LIFTING INTO THE MVFR CATEGORY BY 14Z...THEN
BECOMING VFR AFTER 16Z AT ALL SITES. RAIN WILL ONCE AGAIN BE A
POSSIBILITY THROUGH THE DAY MONDAY...WITH THE HIGHEST CHANCES OFF
TO THE EAST OF ALL TERMINALS. WINDS WILL REMAIN GENERALLY OUT OF
THE NORTHEAST TO EAST THROUGH THE PERIOD.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CONDITIONS ARE POSSIBLE
DURING THE MORNING HOURS THROUGH THE PERIOD. THESE CONDITIONS MAY
ALSO OCCUR IN AFTERNOON SHOWERS AND CONVECTION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
325 AM CDT SAT AUG 2 2014
.DISCUSSION...
323 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH CONTINUED SLIGHT
CHANCES/CHANCES FOR SHOWERS AND THUNDERSTORMS TODAY THROUGH NEXT
WEEK.
GENERAL QUIET CONDITIONS OVER THE CWA EARLY THIS MORNING WITH THE
LAST OF THE MID/HIGH LEVEL CLOUD COVER SLOWLY EXITING THE SOUTHERN
CWA. ANY PRECIP ACROSS THE REGION AT THIS HOUR IS TO THE SOUTHEAST
OVER INDIANA AS THE SHORTWAVE ENERGY WHICH BROUGHT
SHOWERS/THUNDERSTORMS OVER THE CWA ON FRIDAY SLOWLY DRIFTS
EAST...AND WITH THE CWA CURRENTLY IN MORE OF A SUBSIDENT
ENVIRONMENT ON THE BACKSIDE OF THIS SYSTEM. AS CLOUDS FURTHER
CLEAR...STILL AM A LITTLE CONCERNED WITH THE CURRENT PATCHY FOG
DEVELOPMENT IN PLACE TO EXPAND WITH POSSIBLE PATCHY DENSE FOG
DEVELOPING. SHORT TERM GUIDANCE CONTINUES TO ADVERTISE THIS IDEA
OVER THE NEXT SEVERAL HOURS WITH THE MORE FAVORED LOCATIONS OVER
EAST CENTRAL ILLINOIS AND NORTHWEST INDIANA...WHICH DOES SEEM
REASONABLE AS HIGHER MOISTURE CONTENT WITH LOWER DEWPOINT
DEPRESSIONS RESIDES. MADE MENTION OF FOG IN THE GRIDS THIS
MORNING...AND WILL CONTINUE TO MONITOR TRENDS FOR POSSIBLE DENSE
FOG.
DID BACK OFF ON POPS FOR SHOWERS AND THUNDERSTORMS TODAY...AND NOW
ONLY KEEP SLIGHT CHANCE POPS FOR LATER THIS AFTERNOON OVER THE
ENTIRE AREA. GUIDANCE DOES VARY THIS MORNING FROM NOT DEVELOPING
ANYTHING...TO DEVELOPING SCATTERED DEVELOPMENT BY EARLY THIS
AFTERNOON. DID TREND MORE TOWARDS THE LESSER COVERAGE...AS
SHORTWAVE ENERGY TO THE EAST CONTINUES TO EXIT AND ANOTHER
SHORTWAVE TO THE NORTH DROPS EAST/SOUTHEAST TODAY. AS THIS
OCCURS...A PERIOD OF MID/UPPER LEVEL RIDGING WILL OCCUR OVER THE
CWA. DESPITE FAVORABLE THERMODYNAMICS...THE LARGE SCALE SUPPORT
WILL NOT BE THERE. THAT BEING SAID...THERE WILL BE A
MOISTURE/INSTABILITY AXIS IN PLACE TODAY ALONG WITH POSSIBLE WEAK
CONVERGENCE ALONG THE LAKE BREEZE THAT COULD SUPPORT AT LEAST SOME
ISOLATED SHOWER/THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON. SO
ONCE AGAIN DID LEAVE SLIGHT CHANCE MENTION FOR THIS AFTERNOON BUT
WITH ANYTHING THAT DOES DEVELOP TO BE ISOLATED AND BRIEF. WITH THE
LARGE SCALE SUPPORT NOT THERE...AM NOT OVERLY CONCERNED WITH ANY
STRONGER DEVELOPMENT. LACK OF CLOUD COVER AND PRECIP SHOULD ALLOW
FOR TEMPS TO RISE TO THE LOW TO MID 80S...AND DID ADJUST UPWARDS
STAYING SLIGHTLY HIGHER THAN GUIDANCE.
AFTER A QUIET/DRY NIGHT TONIGHT...BETTER SUPPORT ALOFT PUSHING
THROUGH THE CWA WITH SIMILAR TEMP/MOISTURE CONDITIONS IN PLACE ON
SUNDAY SHOULD HELP BRING A RETURN TO SLIGHTLY BETTER CONDITIONS
FOR PRECIP DEVELOPMENT ON SUNDAY. GUIDANCE DOES BEGIN TO DIVERGE
INTO NEXT WEEK...HOWEVER...IT DOES APPEAR AS IF CONDITIONS WILL
CONTINUE TO BE FAVORABLE FOR THUNDERSTORM DEVELOPMENT THROUGH THE
REMAINING FORECAST PERIOD.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LAKE BREEZE WITH NORTHEAST-EAST WINDS.
* SMALL CHANCE OF ISOLATED TSRA THIS AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
WEAK ILL-DEFINED SURFACE TROUGH WILL DRIFT SOUTH ACROSS THE
FORECAST AREA DURING THE PRE-DAWN HOURS...THOUGH SURFACE WINDS
WILL BE CALM OR LIGHT/VARIABLE. SURFACE PRESSURE GRADIENT WILL
REMAIN VERY WEAK TODAY...THOUGH VARIABLE WINDS ARE EXPECTED TO
BECOME LIGHT NORTHEAST WITH THE TROUGH AXIS SOUTHEAST OF THE
TERMINALS. SYNOPTIC NORTHEAST WIND SHOULD BE AIDED BY LAKE BREEZE
ENHANCEMENT BY EARLY AFTERNOON...WITH WINDS EVENTUALLY BECOMING
LIGHT EAST-SOUTHEAST BY EARLY EVENING.
MID-LEVEL SUBSIDENCE DEVELOPS BY THIS AFTERNOON WITH THE TROUGH
AXIS OFF TO THE SOUTHEAST AND SHORT WAVE RIDGING DEVELOPING ALOFT.
FORECAST SOUNDINGS CONTINUE TO DEPICT WEAK INSTABILITY DEVELOPING
DURING THE AFTERNOON HOWEVER...WHICH COULD RESULT IN ISOLATED TSRA
DEVELOPMENT. LAKE BREEZE BOUNDARY COULD BE ONE LOW LEVEL
CONVERGENT FEATURE WHERE ISOLATED TSRA COULD DEVELOP...THOUGH
WITH LESS LARGE SCALE SUPPORT COVERAGE IS EXPECTED TO BE MUCH
LOWER THAN ON FRIDAY. THUS HAVE MAINTAINED DRY TAFS WITH LOW
CONFIDENCE IN LOCATION AND POINT PROBABILITY AT ANY LOCATION LOWER
THAN 30 PERCENT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LAKE BREEZE DEVELOPMENT. MEDIUM-LOW
CONFIDENCE IN TIMING SUSTAINED EAST-NORTHEAST WIND.
* LOW CONFIDENCE IN ISOLATED TSRA DEVELOPMENT THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY THROUGH THURSDAY...PERIODIC CHANCES FOR SHRA/TSRA BUT
PREDOMINANTLY VFR.
IZZI
&&
.MARINE...
221 AM CDT
MARINE FORECAST CONCERNS REMAIN FEW AS WEAK HIGH PRESSURE AND BAGGY
SURFACE PRESSURE GRADIENT LINGER ACROSS THE REGION THROUGH EARLY
NEXT WEEK. WINDS ACROSS LAKE MICHIGAN WILL BE DRIVEN BY DAILY LAKE
BREEZE CIRCULATIONS...AS WELL AS A COUPLE OF WEAK SURFACE TROUGH
PASSAGES...THOUGH WIND SPEEDS EXPECTED TO REMAIN GENERALLY LESS THAN
15 KT FOR MUCH OF THE FORECAST PERIOD. BY MID-WEEK...MEDIUM RANGE
MODELS CONTINUE TO INDICATE LOW PRESSURE DEVELOPING ACROSS THE
PLAINS...THOUGH EASTWARD PROGRESS HAS BEEN SLOWED AND SOME
DISAGREEMENT EXISTS IN THE STRENGTH OF THE LOW AS WELL.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
258 AM CDT Sat Aug 2 2014
.DISCUSSION...
ISSUED 258 AM CDT Sat Aug 2 2014
SHORT TERM...Today through Monday
07z/2am radar imagery shows a few lingering showers and thunderstorms
across the southeast KILX CWA, with dry conditions elsewhere around
central Illinois. Upper trough responsible for the convection is
slowly sliding eastward and will be positioned over eastern Indiana
by midday. As a result, strongest synoptic lift will be focused
further east across the Ohio River Valley today. Despite an
uncapped airmass featuring CAPE values of around 1500J/kg, think
slightly warmer temps aloft and subsidence on the back side of the
trough will prevent precip development later today. Most model
guidance agrees, with only the 4km WRF-NMM showing widely
scattered convection developing across north-central Illinois late
this afternoon. Given good model agreement, have opted to remove
slight chance PoPs and go with a dry forecast.
Surface high pressure will control the weather on Sunday, leading
to a warm/dry day with highs climbing into the lower to middle
80s. Once the high slides off to the east, an approaching
short-wave and associated frontal boundary will begin to increase
rain chances early next week. Monday appears to be the last
completely dry day of the forecast period, with forcing remaining
N/NW of central Illinois.
LONG TERM...Tuesday through Friday
Cold front will sag southward and become nearly stationary across
central Illinois beginning on Tuesday. Several upper short-waves
are expected to ride along the boundary, producing periodic
showers/thunder throughout the week. It is difficult to pinpoint
the exact timing and track of these subtle features this far in
advance, so chance PoPs will be included in the forecast from
Tuesday through Friday. As timing becomes a little more clear, may
be able to pin down a period or two where PoPs will be higher and
other times where conditions will remain dry. As it stands now, a
warm and somewhat unsettled week is unfolding. Most model
solutions gradually drop the boundary southward into the Ohio
River Valley by the end of the week, so rain chances will likely
diminish from north to south by Friday/Saturday.
Barnes
&&
.AVIATION...
ISSUED 1143 PM CDT Fri Aug 1 2014
Main concern for the upcoming TAF set is with visibilities through
early morning. Although convection has ended, skies still mostly
cloudy as of late evening. Satellite imagery showing this will be
eroding from KBMI/KDEC westward over the next few hours, but may
persist at KCMI a good part of the night. Already seeing some
patchy MVFR visibility around 5SM, and am expecting this to become
more widespread. Have introduced a period of lower visibilities of
2 to 3SM from about 10-13Z with the winds nearly calm and recent
rainfall. Heaviest rain on Friday occurred near KSPI and KDEC, and
went with lower visibilities around 2SM there. RAP model soundings
showing the fog should be rather shallow. After that, some
scattered diurnal cumulus expected to develop around 4000 feet,
but the threat of rain should be further east.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1248 AM CDT SAT AUG 2 2014
.DISCUSSION...
143 PM CDT
THIS EVENING THROUGH TONIGHT...
VISIBLE IMAGERY THIS AFTERNOON SHOWS A CIRRUS SHIELD FLOATING
OVERHEAD...WITH SOME POCKETS OF CUMULUS BUILDING ACROSS THE REGION.
THE LAKE BREEZE WAS BEGINNING TO BE DEPICTED WELL ALONG THE
LAKESHORE...WHICH WAS CREATING A LCL CONVERGENCE ZONE AND ALLOWING
SOME OF THE CUMULUS CLOUDS TO ENHANCE SLIGHTLY. SFC TEMPS THIS AFTN
HAVE BEEN ABLE TO WARM INTO THE PR 70S TO LOW 80S...WITH DEW POINTS
GENERALLY AROUND 60 DEGREES. ACARS SOUNDINGS INDICATE THE MORNING
CAPPED ENVIRONMENT HAS DISSOLVED WITH VERY SKINNY CAPE ACROSS THE
FORECAST AREA. GIVEN THE LACK OF SHEAR THROUGHOUT THE
COLUMN...AROUND 10-20KTS...IT DOES NOT APPEAR ANY CONVECTION THAT
DEVELOPS WILL BE ABLE TO PUSH TOWARDS SEVERE LIMITS. HOWEVER A FEW
HAVE BEEN ABLE TO STRENGTHEN AND PRODUCE AROUND 0.5" DIAMETER HAIL
AND A BRIEF GUST TO 50 MPH. THE LARGEST CONCERN OF ANY WILL BE THE
SLOW MOVING NATURE OF THE CONVECTION...WHICH WILL LIKELY INCREASE
THE CONCERN FOR LOCALIZED PONDING/FLOODING.
THE ATMOSPHERE WILL REMAIN UNSTABLE THROUGH EARLY THIS EVENING...AND
EXPECT ONCE SUNSET OCCURS THE MINIMAL COVERAGE OF STORMS WILL BECOME
EVEN LESS THROUGHOUT THE LATE EVENING HOURS.
TONIGHT...INSTABILITY WILL CONTINUE TO WEAKEN THROUGH THE OVERNIGHT
HOURS. MID-LVL TROUGH AXIS WILL CONTINUE TO PIVOT EAST OVER THE
FORECAST AREA TONIGHT...WHICH WILL ALSO BRING LESS FOCUS FOR PRECIP.
SO HAVE TRENDED DRY OVERNIGHT. HOWEVER WITH THE LACK OF DRYING AT
THE SFC...LLVL MOISTURE SHUD REMAIN AND THE COMBINATION OF LIGHT
WINDS WILL LIKELY ALLOW FOR PATCHY FOG TO DEVELOP. AT THIS TIME
EXPECT VSBYS TO NOT GO BELOW 2SM...ALTHOUGH COULD SEE A FEW POCKETS
WHERE AFTN RAINFALL COULD FURTHER REDUCE VSBYS TO ARND 1SM.
SATURDAY THROUGH SUNDAY...
HIGH AMPLITUDE RIDGE ACROSS THE WESTERN CONUS WILL KEEP THE
CONTINUED NORTHWEST FLOW IN PLACE FOR THE GREAT LAKES REGION THROUGH
SAT AND LIKELY INTO SUN. GUIDANCE CONTINUES TO INDICATE A LULL IN
ACTIVITY TO START THE DAY SAT...WITH A LACK OF ANY WAVES OVERHEAD.
ALTHOUGH BY MIDDAY SAT THERE IS A WEAK MID-LVL WAVE SLIDING
SOUTHEAST ACROSS THE WESTERN GREAT LAKES. THIS COMBINED WITH WEAK
SFC INSTABILITY COULD LEAD TO A FEW SPOTTY SHOWERS/THUNDERSTORMS TO
ONCE AGAIN DEVELOP. THERE DOES APPEAR TO BE ANOTHER LAKE BREEZE FOR
SAT/SUN...WHICH WOULD ALSO ADD TO THE LOCALIZED CONVERGENCE AND
FOCUS A FEW PULSE STORMS. TEMPS SHUD AGAIN NEAR SEASONAL CONDS
SAT/SUN WITH HIGHS GENERALLY ARND 80 BOTH DAYS. DEPENDING ON THE
TIMING OF THE LAKE BREEZE...TEMPS DOWNTOWN CHICAGO COULD HOLD IN THE
UPR 70S BEFORE FALLING INTO THE LOW 70S BEHIND THE LAKE BREEZE.
MONDAY THROUGH END OF NEXT WEEK...
ENSEMBLES IN THE LONG RANGE APPEAR TO BE SUGGESTING THE NORTHERN
ATLANTIC BLOCK WILL WEAKEN...ALLOWING THE PERSISTENT TROUGH OVER THE
GREAT LAKES TO PIVOT EAST AND FLATTEN THE WESTERN RIDGE LATER IN THE
WEEK. THIS POINTS TOWARDS AN INCREASE IN THE ACTIVITY OF SYSTEMS
SLIDING WEST TO EAST ACROSS THE NORTHERN CONUS. SO PERIODIC CHANCES
FOR SHOWERS/STORMS IN THE EXTENDED LOOKS PROBABLE. TEMPS SHOULD BE
SLIGHTLY SUB-SEASONAL THROUGH THE FIRST HALF OF NEXT WEEK...THEN
SLOWLY WARM BACK INTO THE LOWER 80S TOWARDS THE END OF THE EXTENDED
PERIODS.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* LAKE BREEZE WITH NORTHEAST-EAST WINDS.
* SMALL CHANCE OF ISOLATED TSRA THIS AFTERNOON.
RATZER
//DISCUSSION...UPDATED 06Z...
WEAK ILL-DEFINED SURFACE TROUGH WILL DRIFT SOUTH ACROSS THE
FORECAST AREA DURING THE PRE-DAWN HOURS...THOUGH SURFACE WINDS
WILL BE CALM OR LIGHT/VARIABLE. SURFACE PRESSURE GRADIENT WILL
REMAIN VERY WEAK TODAY...THOUGH VARIABLE WINDS ARE EXPECTED TO
BECOME LIGHT NORTHEAST WITH THE TROUGH AXIS SOUTHEAST OF THE
TERMINALS. SYNOPTIC NORTHEAST WIND SHOULD BE AIDED BY LAKE BREEZE
ENHANCEMENT BY EARLY AFTERNOON...WITH WINDS EVENTUALLY BECOMING
LIGHT EAST-SOUTHEAST BY EARLY EVENING.
MID-LEVEL SUBSIDENCE DEVELOPS BY THIS AFTERNOON WITH THE TROUGH
AXIS OFF TO THE SOUTHEAST AND SHORT WAVE RIDGING DEVELOPING ALOFT.
FORECAST SOUNDINGS CONTINUE TO DEPICT WEAK INSTABILITY DEVELOPING
DURING THE AFTERNOON HOWEVER...WHICH COULD RESULT IN ISOLATED TSRA
DEVELOPMENT. LAKE BREEZE BOUNDARY COULD BE ONE LOW LEVEL
CONVERGENT FEATURE WHERE ISOLATED TSRA COULD DEVELOP...THOUGH
WITH LESS LARGE SCALE SUPPORT COVERAGE IS EXPECTED TO BE MUCH
LOWER THAN ON FRIDAY. THUS HAVE MAINTAINED DRY TAFS WITH LOW
CONFIDENCE IN LOCATION AND POINT PROBABILITY AT ANY LOCATION LOWER
THAN 30 PERCENT.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN LAKE BREEZE DEVELOPMENT. MEDIUM-LOW
CONFIDENCE IN TIMING SUSTAINED EAST-NORTHEAST WIND.
* LOW CONFIDENCE IN ISOLATED TSRA DEVELOPMENT THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY THROUGH THURSDAY...PERIODIC CHANCES FOR SHRA/TSRA BUT
PREDOMINANTLY VFR.
IZZI
&&
.MARINE...
226 PM CDT
NO MAJOR CONCERNS FOR THE LAKE THROUGH THE PERIOD. A WEAK SURFACE
TROUGH WILL PASS THROUGH THE LAKE THROUGH TONIGHT. BROAD HIGH
PRESSURE ACROSS THE PLAINS AND EXTENDING INTO THE UPPER MIDWEST AND
THROUGH THE OHIO VALLEY WILL MOVE OVERHEAD SATURDAY AND THROUGH THE
WEEKEND. AS THE HIGH BUILDS IN...WINDS WILL TURN NORTHERLY ACROSS
THE LAKE...AND THEN GENERALLY BECOME LIGHT AND VARIABLE SATURDAY
NIGHT. WITH THE WEAK PRESSURE GRADIENT EXPECT LAKE BREEZES TO
CONTINUE INTO SUNDAY. ANOTHER WEAK LOW WILL PASS BY TO THE NORTH OF
THE LAKE EARLY SUNDAY THAT WILL TIGHTEN THE GRADIENT WILL BIT SUNDAY
ACROSS THE NORTHERN PART OF THE LAKE IN WITH SOUTH WINDS INCREASING
BUT STILL REMAINING UNDER 15 KT OR SO. A WEAK FRONT ASSOCIATED WITH
THIS LOW WILL THEN DISSIPATE WITH THE GRADIENT AGAIN BECOMING RATHER
WEAK SUNDAY NIGHT INTO MONDAY. LONGER RANGE GUIDANCE HAS BACKED OFF
ON THE EASTWARD MOVEMENT OF A SOMEWHAT STRONGER LOW OVER THE
PLAINS...THUS WITH HIGH PRESSURE TO THE NORTH OR OVERHEAD EXPECT
NORTH TO NORTHEAST WINDS FOR SOMETIME BEFORE SHIFTING MORE SOUTHERLY
LATER IN THE WEEK. WAVES GENERALLY REMAIN 2 FT OR LESS FOR THE
FORESEEABLE FUTURE.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1143 PM CDT Fri Aug 1 2014
.DISCUSSION...
ISSUED 900 PM CDT Fri Aug 1 2014
Much of the convection that formed earlier today has faded with
sunset, but some storms persist from near Beardstown northwest
toward Burlington IA. That particular area still has some CAPE`s
around 1500 J/kg per SPC mesoanalysis, which will help sustain them
for another hour or two, although the latest RAP model shows the
instability weakening with time.
Large area of mostly clear skies west of the Mississippi River,
and skies should start clearing from west to east in our area,
although clouds will likely hang on near the Indiana border much
of the night. Development of fog is most likely in the areas that
had the most rain earlier today, with nearly calm winds overnight,
with speed of development based on the clearing.
Have sent some updated grids to reflect latest precipitation and
temperature trends. Updated zones to follow shortly.
Geelhart
&&
.AVIATION...
ISSUED 1143 PM CDT Fri Aug 1 2014
Main concern for the upcoming TAF set is with visibilities through
early morning. Although convection has ended, skies still mostly
cloudy as of late evening. Satellite imagery showing this will be
eroding from KBMI/KDEC westward over the next few hours, but may
persist at KCMI a good part of the night. Already seeing some
patchy MVFR visibility around 5SM, and am expecting this to become
more widespread. Have introduced a period of lower visibilities of
2 to 3SM from about 10-13Z with the winds nearly calm and recent
rainfall. Heaviest rain on Friday occurred near KSPI and KDEC, and
went with lower visibilities around 2SM there. RAP model soundings
showing the fog should be rather shallow. After that, some
scattered diurnal cumulus expected to develop around 4000 feet,
but the threat of rain should be further east.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 325 PM CDT Fri Aug 1 2014
Very little change to our overall weather pattern is expected into
the middle of next week as the upper level northwest flow
continues. This will result in temperatures at or just below
seasonal normals, with shortwave troughs providing a focus for
showers/t-storms Tuesday and Wednesday. Medium range models
showing a shift in our pattern by Thursday, but there are quite a
few differences regarding how this will take place and what the
associated sensible weather will be.
SHORT TERM...Tonight through Sunday Night
Diurnal convection this afternoon has been getting a boost from a
shortwave trough moving into the area. The surface reflection was
only a weak wind shift, but this was enough to combine with the
instability and convective updrafts to produce several funnel
clouds in central and east central IL this afternoon. The radar
indicated a myriad of outflow boundaries with scattered
thunderstorms east of the IL River and very isolated showers to
the west. Will keep the mention of scattered t-storms in the
forecast for this evening generally along and east of I-55, with a
mention of isolated showers/few t-storms to the west.
The scattered rainfall, some of which was heavy in spots, will
contribute low level moisture to help produce patchy fog overnight
and into Saturday morning. The shortwave moving across the Midwest
tonight could linger just long enough in extreme eastern IL to
produce scattered showers/t-storms early Saturday afternoon.
Otherwise, weak high pressure will begin to approach later
Saturday and settle into the area Sunday with mostly sunny
conditions and temperatures in the lower 80s.
LONG TERM...Monday through Friday
A southerly wind will develop Monday ahead of the next approaching
cold front from the northwest. This will give us gradually
increasing humidity and temperatures closer to normal for early
August.
There are some model differences with the speed of the cold front,
with the GFS being quicker and the European and Canadian on the
slower side. The GFS may be a bit too quick with its frontal
depiction, so will keep the chance for thunderstorms north of I-74
for Monday night, and gradually drop them southward with the front
Tuesday.
As the models start to depict a breakdown in the northwest flow to
more of a zonal flow, their differences start to show up with the
position of the front Wednesday through Friday. The Canadian model
is farther north while the GFS drops it south toward the OH valley
Wednesday then lift it back north as a warm front by Friday.
Prefer the European solution of settling the front into southern
IL then pretty much keeping it there through the end of the week.
This would result in periods of showers and thunderstorms with
high temperatures in the lower to middle 80s.
Miller
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1251 AM EDT SAT AUG 2 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 234 PM EDT FRI AUG 1 2014
AN UPPER LEVEL DISTURBANCE ACROSS NORTHERN ILLINOIS WILL MOVE EAST
SOUTHEAST ACROSS OUR REGION TONIGHT AND SATURDAY RESULTING WITH
SCATTERED SHOWERS AND THUNDERSTORMS. THIS UPPER DISTURBANCE WILL
MOVE ON TO THE EAST SATURDAY NIGHT AND WEAK HIGH PRESSURE WILL BUILD
ACROSS OUR REGION SUNDAY AND MONDAY.
IN THE LONG TERM...CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
INCREASE ONCE AGAIN AS A FRONTAL SYSTEM MOVES SOUTH INTO OUR REGION
TUESDAY AND WEDNESDAY AND THEN STALLING NEAR THE OHIO RIVER THURSDAY
AND THEN MOVING BACK TO THE NORTH ON FRIDAY.
&&
.NEAR TERM /TONIGHT AND SATURDAY/...
ISSUED AT 944 PM EDT FRI AUG 1 2014
AS EXPECTED...COVERAGE AND INTENSITY OF CONVECTION HAS WANED
CONSIDERABLY AS THE SUN HAS SET. GENERALLY EXPECTING ONLY ISOLATED
TSTORM COVERAGE AT BEST REMAINDER OF THE NIGHT. THE SOLE POTENTIAL
EXCEPTION TO THIS IS SMALL STORM COMPLEX OVER NORTHERN
ILLINOIS/SOUTHERN WISCONSIN WHICH HAS THE ASSISTANCE OF A COMPACT
SHORTWAVE DROPPING THROUGH WISCONSIN AND NUMEROUS BOUNDARIES FROM
PRIOR CONVECTION...AS WELL AS POTENTIAL REMNANT LAKE BREEZE
BOUNDARY...AND HAS HELD ITS OWN FOR A WHILE NOW. THAT
SAID...ENVIRONMENT REMAINS EXTREMELY WEAKLY SHEARED IF AT
ALL...INSTABILITY IS 1000 J/KG OR LESS AND WANING...AND CONVECTIVE
INHIBITION IS INCREASING. THUS...EXPECT THIS COMPLEX TO WEAKEN OR
DIE BEFORE MAKING THE AREA...AND HRRR BEARS THIS OUT.
DID ADD A PATCHY FOG MENTION TO THE NORTHWESTERN FORECAST AREA
WHERE SIGNIFICANT RAINFALL AND ACCUMULATING HAIL OCCURRED DURING
THE LATE AFTERNOON HOURS. SOME LIGHT FOG MAY OCCUR ELSEWHERE BUT
BE LIMITED BY CLOUD COVER AND LIKELY NOT WORTH A GRID MENTION.
REMAINDER OF FORECAST IN EXCELLENT SHAPE AND DID NOT MAKE MAJOR
CHANGES.
PREVIOUS DISCUSSIONS FOLLOW.
ISSUED AT 634 PM EDT FRI AUG 1 2014
FOR THE UPDATE...HAVE INCREASED POPS WHERE NECESSARY OWING TO
RECENT CONVECTIVE COVERAGE. SHOULD STILL SEE ACTIVITY ON A
DOWNSWING AROUND SUNSET AS HEATING IS LOST...BUT WITH UPPER TROUGH
SWINGING THROUGH THE AREA...WILL AS WITH PRIOR FORECAST CONTINUE
AT LEAST SOME LOW POPS THROUGHOUT THE NIGHT. STRONGEST STORMS WILL
REMAIN CAPABLE OF PRODUCING SMALL HAIL...PERHAPS PRODIGIOUSLY AS
OCCURRED WITHIN THE LAST TWO HOURS IN THE LAFAYETTE AREA...VERY
HEAVY RAINFALL...LIGHTNING AND GUSTY WINDS...ALTHOUGH THEY ARE
UNLIKELY TO BECOME SEVERE AS SHEAR IS EXTREMELY WEAK. THE LARGE
AMOUNTS OF SMALL HAIL FROM THE STRONGEST CORE OF THE DAY IN
LAFAYETTE IS TYPICAL OF SUCH CORES IN WEAKLY SHEARED ENVIRONMENTS.
PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 234 PM EDT FRI AUG 1 2014
RADAR INDICATED SCATTERED THUNDERSTORMS HAVE DEVELOPED ACROSS
NORTHWEST INDIANA AS WELL AS CENTRAL AND NORTHEAST ILLINOIS. THIS
IS IN RESPONSE TO AN UPPER LEVEL DISTURBANCE OVER NORTHERN
ILLINOIS. MODELS INDICATE THIS UPPER LEVEL DISTURBANCE WILL MOVE
EAST SOUTHEAST ACROSS THE NORTHERN AND THE EAST CENTRAL PARTS OF OUR
REGION LATER TONIGHT.
ONE QUESTION IS HOW MUCH OF THIS CONVECTION WILL CONTINUE AFTER
SUNSET AS IT HAS BEEN QUITE DIURNAL LAST FEW DAYS. BOTH THE NAM AND
GFS KEEP SOME CONVECTION ACROSS THE NORTHERN AND CENTRAL PARTS OF
OUR REGION TONIGHT AS THE UPPER TROUGH SHARPENS UP. IT MAY BE A BIT
OVERDONE...BUT NERVELESS WILL KEEP POPS IN CHANCE CATEGORY OVER
NORTHERN AND CENTRAL SECTIONS THIS EVENING AND EAST CENTRAL PARTS
INTO LATE TONIGHT PER MODELS. IN OTHER AREAS SHOWERS SHOULD DIMINISH
LATE TONIGHT.
ON SATURDAY EXPECT SCATTERED SHOWERS AND THUNDERSTORMS OVER EASTERN
AND CENTRAL SECTIONS AND WIDELY SCATTERED THUNDERSTORMS ELSEWHERE.
THERE MAY BE SOME INCREASE WITH DAYTIME HEATING...BUT AT THE SAME
TIME THE UPPER DISTURBANCE WILL BE MOVING ON EAST INTO OHIO.
IN REGARDS TO TEMPERATURES WENT WITH A MOS BLEND MOST AREAS
TONIGHT. WILL KEEP NORTHEAST AREAS AT OR ABOVE 60 WITH MORE CLOUDS
THERE LATER TONIGHT.
ON SATURDAY PREFER THE COOLER MET TEMPERATURES OVER CENTRAL AND
WESTERN AREAS AND WENT WITH A MOS BLEND IN THE EAST. THE MET HAS 74
FOR A HIGH AT MUNCIE...WHILE THE MAV IS 82. MORE CLOUDS IN THE EAST
COULD HOLD TEMPERATURES DOWN THERE A LITTLE MORE...BUT 74 SEEMS A
BIT TOO COOL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
ISSUED AT 234 PM EDT FRI AUG 1 2014
SHOWERS WILL QUICKLY END SATURDAY EVENING...FOR NOW WILL CONTINUE
SLIGHT CHANCE POPS IN THE EAST SATURDAY EVENING. OTHERWISE...DRY ALL
AREAS REST OF THE SHORT TERM AS WEAK HIGH PRESSURE BUILDS ACROSS OUR
REGION. A COLD FRONT WILL BE MOVING INTO THE SOUTHERN GREAT LAKES ON
MONDAY...BUT IT SHOULD BE STILL FAR ENOUGH TO THE NORTH FOR US TO
REMAIN DRY.
MODEL SOUNDINGS INDICATE MOSTLY CLEAR CONDITIONS WILL BE THE RULE AS
AIR MASS BECOMES A LITTLE DRIER AND HEIGHTS RISE A LITTLE. 850 MB
TEMPERATURES WARM UP ONLY ABOUT A DEGREE SUNDAY AND MONDAY AS MODELS
KEEP A WEAK THERMAL TROUGH ACROSS OUR REGION. OVERALL A MOS BLEND
BLEND ON TEMPERATURES SEEM REASONABLE WITH HIGHS IN THE LOWER TO
MIDDLE 80S BOTH DAYS AND LOWS IN THE UPPER 50S TO LOWER 60S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 234 PM EDT FRI AUG 1 2014
AFTER A DRY SPELL ENSEMBLES HINTING AT CENTRAL INDIANA POSSIBLY
RETURNING TO A WETTER PATTERN AS HIGH PRESSURE MOVES OFF THE EAST
MONDAY/MONDAY NIGHT AND IS REPLACED BY AN UPPER TROUGH THAT WILL
SLOWLY SHIFT EASTWARD THROUGH THURSDAY WITH SEVERAL UPPER WAVES
MOVING THROUGH THIS FEATURE THAT COULD PRODUCE CHANCES FOR SHOWERS
AND THUNDERSTORMS. THERE IS NOT A LOT OF CONSISTENCY AND TIMING TO
THIS LATEST SOLUTION SO CONFIDENCE IS LOW...AND THEREFORE LEFT POPS
AT LOW END CHANCE MOST TIMES. MODELS HINTING AT A MORE SIGNIFICANT
COLD FRONTAL PASSAGE TOWARD THE END OF THE PERIOD BUT TIMING DIFFERS
AMONGST THE GUIDANCE. ALLBLEND IS CARRYING SLIGHTLY HIGHER POPS
TOWARD THE END OF THE WORK WEEK...WITH 20-30 PERCENT CHANCES LEADING
UP TO THURSDAY. TEMPERATURES WILL BE BACK AROUND THE NORMAL RANGE
FOR THIS TIME OF YEAR...LOW TO MID 80S HIGHS FOR HIGHS AND LOWS IN
THE MID TO UPPER 60S.
&&
.AVIATION /DISCUSSION FOR THE 020600Z TAFS/...
ISSUED AT 1251 AM EDT SAT AUG 2 2014
EARLIER CONVECTION HAS DISSIPATED...HOWEVER AN AREA OF RAIN IS
EXPANDING ACROSS PARTS OF WEST CENTRAL INDIANA ASSOCIATED WITH AN
UPPER WAVE. SHORT TERM MODELS SUGGEST THIS WAVE WILL PASS OVER THE
TAF SITES DURING THE EARLY MORNING HOURS ON SATURDAY. SOME LIGHT
RAIN AND POSSIBLY EMBEDDED THUNDER EXPECTED MAINLY AT KHUF/KIND/KBMG
THROUGH ABOUT 021000Z.
OTHERWISE...FOG IS BEGINNING TO FORM EARLIER THAN EXPECTED DESPITE
THE CLOUD COVER. AREAS OF IFR VISIBILITY RESTRICTIONS LOOK MORE
LIKELY NOW...SO WILL ADD THEM TO THE FORECAST ROUGHLY
020700Z-021300Z. CEILINGS GENERALLY ABOVE 050 EXPECTED THROUGH ABOUT
MID MORNING SATURDAY BEFORE SCATTERING OUT AS THE WAVE DEPARTS.
SCATTERED DIURNAL CLOUDS BASED AROUND 030 EXPECTED TO DEVELOP AROUND
MIDDAY SATURDAY.
NO WIND ISSUES EXPECTED THROUGH 021800Z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...JH
NEAR TERM...JH/NIELD
SHORT TERM...JH
LONG TERM...SMF
AVIATION...JAS/CP
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AREA FORECAST DISCUSSION
NWS DODGE CITY KS
651 PM CDT Sun Aug 3 2014
...Updated aviation section...
.SHORT TERM...(This evening through Monday)
ISSUED AT 333 PM CDT SUN AUG 3 2014
This mornings convective allowing models allowed some room for
convection to develop once again just north of the I-70 corridor and
be driven southeast by the man flow, much like last evening. So far
this afternoon the area of enhanced cu development across northwest
Kansas has not shown signs of stronger shower or storm development
although the GLD 88D was indicating rain in the HCA. We will
continue to carry less than 20 PoPs trough the end of the afternoon
and early evening to see how this evolves, especially given the
increasingly robust HRRR model drives a few storms into Rush and
Stafford counties.
For the rest of the period including tonight into tomorrow, we
followed the NAM and Raw Model Blend which seemed to do the best job
collectively with temperatures and surface winds for yesterday.
little overall change in airmass will take place with the upper
ridge settling slightly farther east.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 350 PM CDT SUN AUG 3 2014
Drier conditions will persist across western Kansas through early
Tuesday afternoon as an upper level ridge axis shifts eastward across
the Western High Plains. Medium range models then indicate the ridge
breaking down late Tuesday as a series of H5 vort maxima associated
with a shortwave eject out of the Rockies into the high plains of
western Nebraska and western Kansas. A developing lee side trough
will strengthen as the shortwave approaches while low/mid level
moisture continues to pool slowly across central and portions of
western Kansas. This will set the stage for possible thunderstorm
development across portions of southwest and central Kansas Tuesday
evening into Wednesday. Although low/mid level lapse rates will
steepen through the afternoon period Tuesday, NAM/GFS model
soundings show very little instability in regards to available CAPE
with values well under 100 J/KG. This will likely hinder storm
development through much of the afternoon with chances increasing
Tuesday evening as CAPE begins to rise. Although less than
favorable, a slightly strengthened flow aloft along with decent
directional shear may be enough to support stronger thunderstorms
with gusty winds the primary threat.
Precip chances will shift eastward across western into central
Kansas Wednesday as the surface trough migrates through.
Thunderstorms will be possible again into Thursday as H5 vort
maxima continue to move out of the Rockies into the Western High
Plains. However, better chances will be more to the north across
west central and central Kansas in association with the stronger
flow. Seasonal temperatures will continue through Thursday as a
south to southeasterly flow prevails through much of the period.
This will reinforce the warm air mass already in place across
western Kansas keeping highs up into the 90s(F) each day through
the end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 648 PM CDT SUN AUG 3 2014
Persistence is the best forecast in this environment with upper
level ridging prevailing and a lee trough setup that remains
unchanged for the most part. South winds will average 8 to 11
knots overnight with slightly stronger winds during the afternoon
Monday 13 to 16 knots with gusts in the lower 20s knots.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 92 69 94 / 0 0 0 10
GCK 63 92 68 94 / 0 0 0 20
EHA 64 91 67 95 / 0 0 0 10
LBL 65 93 69 96 / 0 0 0 20
HYS 67 95 70 93 / 20 0 0 10
P28 66 93 69 94 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...JJohnson
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1138 PM CDT Fri Aug 1 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Saturday)
Issued at 332 PM CDT FRI AUG 1 2014
Latest water vapor loops shows a shortwave axis moving over
Missouri with subsidence over eastern Kansas at 19Z. Surface trough
and low extended from northeast to southwest Kansas. Scattered
clouds have developed in layer around 750-700mb and forecast
soundings from the RUC show clouds dissolving by 02Z. Winds expected
to become easterly this evening as the surface low and trough moves
into southeast Kansas. Some isentropic lift develops after 06Z
tonight with low condensation pressure deficits over east central
Kansas. NAM has best lift over southeast Kansas after 09Z on the
305K isentropic surface. Have kept in some partly cloudy skies in
east central Kansas later tonight and into early Saturday morning.
There is little in the way of upper support, but could see some
isolated very light showers or sprinkles develop in the isentropic
lift and models have shown over the last few runs. Lows tonight will
range from the lower to mid 60s.
Saturday, the northwest upper flow continues with heights rising
slightly through the day. Expect highs to be a few degrees warmer
out toward central Kansas and similar to today. Some small chances
of showers are possible on Saturday with weak embedded waves and
some weak isentropic lift especially in the morning. With nothing
showing up upstream in water vapor will keep the dry forecast going.
Models show a 700 mb wave over north central Nebraska Saturday
afternoon. The NAM develops some showers and isolated thunderstorms
across central and parts of east central Kansas in a zone of
700-500mb frontogenesis in the afternoon. Slight warming aloft may
inhibit any precipitation from forming and will increase pops but
remain less than 15 percent attm.
.LONG TERM...(Saturday Night through Friday)
Issued at 332 PM CDT FRI AUG 1 2014
A board upper level ridge across the west-central conus will
gradually build east across the southern plains by mid week.
Weak upper level troughs embedded in northwesterly flow aloft may
provide enough ascent when combined with weak isentropic lift at
night for isolated showers Saturday Night through Sunday night. At
this time I will only carry 10 to 14 pops due to the uncertainty on
areal coverage and timing. Highs on Sunday will be in the upper 80s
to lower 90s. lows will be in the 60s.
It looks dry Monday through Tuesday as the upper level ridge
builds eastward into the southern plains. Highs will be in the lower
to mid 90s. lows will be in the upper 60s to lower 70s.
Tuesday Night through Thursday, A series of upper level troughs will
round the upper level ridge axis across the northern and central
plains. A cold front will also push southward into eastern KS on
Wednesday and may stall out across the CWA through Thursday. The
combination of ascent ahead of the upper level troughs and surface
convergence along the surface cold front will provide the CWA with
chances for showers and thunderstorms. Highs will gradually cool
into the mid 80s to lower 90s, with overnight lows in the mid 60s
to lower 70s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1137 PM CDT FRI AUG 1 2014
Will continue VFR through the period with light SE winds. Stray
showers continue overnight and a slightly better chance for
isolated thunder tomorrow afternoon leads to VCTS in all TAF
sites.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...53
LONG TERM...Gargan
AVIATION...67
AREA FORECAST DISCUSSION
NWS JACKSON KY
403 PM EDT SAT AUG 2 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 301 PM EDT SAT AUG 2 2014
THE HRRR MODEL SEEMED TO HAVE THE BEST HANDLE ON THE SHOWER AND STORM
ACTIVITY THAT HAS BEEN ONGOING ACROSS EASTERN KENTUCKY FOR THE PAST
FEW HOURS. THEREFORE...THE HRRR SOLUTION WAS USED TO CREATE THE NEW
FORECAST PRECIPITATION PROBABILITIES FOR THE AREA FOR THE REST OF
THIS AFTERNOON THROUGH 2Z THIS EVENING. AFTER 2Z TONIGHT...THE NAM12
MODEL WAS USED. SHOWERS AND STORMS ARE EXPECTED TO PERSIST THROUGH
ROUGHLY 2Z THIS EVENING...WITH THE PEAK ACTIVITY OCCURRING DURING
PEAK HEATING HOURS THIS AFTERNOON. A SHORTWAVE TROUGH INTERACTING
WITH LIMITED LOW LEVEL MOISTURE IS THE DRIVING FORCE FOR
PRECIPITATION THIS AFTERNOON...AND WILL BE UNTIL THE TROUGH MOVES
EAST OF THE AREA EARLY THIS EVENING. SOME OF THE STORMS THIS
AFTERNOON HAVE BEEN A BIT STRONG AND CAPABLE OF PRODUCING SMALL
HAIL...LOCALLY HEAVY RAINFALL...AND WIND GUSTS UP TO 30 MPH. AFTER
THIS EVENING...HIGH PRESSURE WILL SETTLE OVER THE AREA...ALLOWING FOR
A DRIER AND SLIGHTLY WARMER PATTERN. HIGHS ON SUNDAY ARE EXPECTED TO
RISE INTO THE LOW TO MID 80S UNDER AMPLE SUNSHINE AND LIGHT WINDS.
LOWS THE NEXT COUPLE OF NIGHTS WILL BOTTOM OUT AROUND 60...WHICH IS
A BIT BELOW NORMAL FOR THIS TIME OF YEAR. THE WEATHER RELATED ISSUED
TO LOOK OVERNIGHT WILL BE FOG FORMATION. FOG WILL BE POSSIBLE IN OUR
RIVER VALLEYS OVERNIGHT. THE MAIN QUESTION WILL BE THE EXTENT AND
DENSITY OF FOG THAT FORMS WHERE PRECIPITATION HAS ALREADY OCCURRED
TODAY. THE OTHER FACTOR INVOLVED WITH THE FOG WILL BE THE AMOUNT OF
CLOUD COVER THAT PERSISTS OVERNIGHT. IF THE CLOUDS CLEAR OUT MORE
QUICKLY THEN FOG FORMATION WILL BE FAVORED...PARTICULARLY FOR
LOCATIONS WHERE IT RAINED TODAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 403 PM EDT SAT AUG 2 2014
THE MODELS REMAIN IN DECENT AGREEMENT WITH THE LONG WAVE PATTERN
THROUGH NEXT WEEKEND. OVERALL...THE FLOW LOOKS TO FLATTEN OUT ACROSS
THE MISSISSIPPI VALLEY...WITH THE DEEPER AND PERSISTENT TROUGHING
BECOMING MORE CONFINED TO THE NORTHEASTERN CONUS.
FOR EASTERN KENTUCKY...DRY WEATHER WILL HANG IN THROUGH
TUESDAY...BEFORE A COLD FRONT SAGS SOUTHEAST AND EVENTUALLY STALLS
ACROSS OUR VICINITY. DAILY CHANCES OF SCATTERED SHOWERS AND
THUNDERSTORMS WILL REIGN FROM TUESDAY NIGHT THROUGH NEXT WEEKEND.
STAYED CLOSE TO THE BLENDED GUIDANCE...ALTHOUGH DID UNDERCUT A BIT IN
THE POPS FURTHER OUT GIVEN THE LOW CONFIDENCE IN TRYING TO NAIL DOWN
SMALLER SCALE FEATURES. TEMPERATURES WILL AVERAGE NEAR NORMAL THROUGH
THE PERIOD AS WELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1 PM EDT SAT AUG 2 2014
THE PRIMARY CONCERN FOR GENERAL AVIATORS WILL BE SHOWER AND
THUNDERSTORM ACTIVITY THIS AFTERNOON AND EVENING ACROSS EASTERN
KENTUCKY. IN GENERAL...VFR CONDITIONS WILL PREVAIL AT THE TAF SITES
THROUGH AROUND 5Z TONIGHT. THE EXCEPTION WILL BE WHENEVER A SHOWER OR
STORM DIRECTLY AFFECTS ONE OF THE AIRPORTS. THE STRONG SHOWERS OR
STORMS COULD PRODUCE MVFR TO IFR CONDITIONS DEPENDING ON HOW INTENSE
THE WINDS AND RAINFALL ARE WITH EACH STORM. THE SHOWERS AND STORMS
ARE EXPECTED TO PERSIST THROUGH AROUND 0Z THIS EVENING...BEFORE
DISSIPATING DUE TO LOSS OF DAYTIME HEATING. OVERNIGHT...THERE IS A
CHANCE OF FOR FORMATION...PARTICULARLY AT JKL AND LOZ WHERE RAINFALL
IS EXPECTED TO OCCUR TODAY OR OCCURRED LAST NIGHT. AT THIS TIME FOG
POTENTIAL WILL BE STRONGLY CONNECTED TO ANY RAINFALL THAT OCCURS
TODAY. IF JKL SEES ANY RAIN TODAY...WHICH IT LOOKS LIKE WE
WILL...THERE IS AN OUTSIDE CHANCE OF IFR CONDITIONS FROM FOG BETWEEN
8 AND 12Z ON SUNDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AR
LONG TERM...GEOGERIAN
AVIATION...AR
AREA FORECAST DISCUSSION
NWS JACKSON KY
301 PM EDT SAT AUG 2 2014
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 301 PM EDT SAT AUG 2 2014
THE HRRR MODEL SEEMED TO HAVE THE BEST HANDLE ON THE SHOWER AND STORM
ACTIVITY THAT HAS BEEN ONGOING ACROSS EASTERN KENTUCKY FOR THE PAST
FEW HOURS. THEREFORE...THE HRRR SOLUTION WAS USED TO CREATE THE NEW
FORECAST PRECIPITATION PROBABILITIES FOR THE AREA FOR THE REST OF
THIS AFTERNOON THROUGH 2Z THIS EVENING. AFTER 2Z TONIGHT...THE NAM12
MODEL WAS USED. SHOWERS AND STORMS ARE EXPECTED TO PERSIST THROUGH
ROUGHLY 2Z THIS EVENING...WITH THE PEAK ACTIVITY OCCURRING DURING
PEAK HEATING HOURS THIS AFTERNOON. A SHORTWAVE TROUGH INTERACTING
WITH LIMITED LOW LEVEL MOISTURE IS THE DRIVING FORCE FOR
PRECIPITATION THIS AFTERNOON...AND WILL BE UNTIL THE TROUGH MOVES
EAST OF THE AREA EARLY THIS EVENING. SOME OF THE STORMS THIS
AFTERNOON HAVE BEEN A BIT STRONG AND CAPABLE OF PRODUCING SMALL
HAIL...LOCALLY HEAVY RAINFALL...AND WIND GUSTS UP TO 30 MPH. AFTER
THIS EVENING...HIGH PRESSURE WILL SETTLE OVER THE AREA...ALLOWING FOR
A DRIER AND SLIGHTLY WARMER PATTERN. HIGHS ON SUNDAY ARE EXPECTED TO
RISE INTO THE LOW TO MID 80S UNDER AMPLE SUNSHINE AND LIGHT WINDS.
LOWS THE NEXT COUPLE OF NIGHTS WILL BOTTOM OUT AROUND 60...WHICH IS
A BIT BELOW NORMAL FOR THIS TIME OF YEAR. THE WEATHER RELATED ISSUED
TO LOOK OVERNIGHT WILL BE FOG FORMATION. FOG WILL BE POSSIBLE IN OUR
RIVER VALLEYS OVERNIGHT. THE MAIN QUESTION WILL BE THE EXTENT AND
DENSITY OF FOG THAT FORMS WHERE PRECIPITATION HAS ALREADY OCCURRED
TODAY. THE OTHER FACTOR INVOLVED WITH THE FOG WILL BE THE AMOUNT OF
CLOUD COVER THAT PERSISTS OVERNIGHT. IF THE CLOUDS CLEAR OUT MORE
QUICKLY THEN FOG FORMATION WILL BE FAVORED...PARTICULARLY FOR
LOCATIONS WHERE IT RAINED TODAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 301 PM EDT SAT AUG 2 2014
AN EXTENDED DISCUSSION WILL BE ISSUED SHORTLY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1 PM EDT SAT AUG 2 2014
THE PRIMARY CONCERN FOR GENERAL AVIATORS WILL BE SHOWER AND
THUNDERSTORM ACTIVITY THIS AFTERNOON AND EVENING ACROSS EASTERN
KENTUCKY. IN GENERAL...VFR CONDITIONS WILL PREVAIL AT THE TAF SITES
THROUGH AROUND 5Z TONIGHT. THE EXCEPTION WILL BE WHENEVER A SHOWER OR
STORM DIRECTLY AFFECTS ONE OF THE AIRPORTS. THE STRONG SHOWERS OR
STORMS COULD PRODUCE MVFR TO IFR CONDITIONS DEPENDING ON HOW INTENSE
THE WINDS AND RAINFALL ARE WITH EACH STORM. THE SHOWERS AND STORMS
ARE EXPECTED TO PERSIST THROUGH AROUND 0Z THIS EVENING...BEFORE
DISSIPATING DUE TO LOSS OF DAYTIME HEATING. OVERNIGHT...THERE IS A
CHANCE OF FOR FORMATION...PARTICULARLY AT JKL AND LOZ WHERE RAINFALL
IS EXPECTED TO OCCUR TODAY OR OCCURRED LAST NIGHT. AT THIS TIME FOG
POTENTIAL WILL BE STRONGLY CONNECTED TO ANY RAINFALL THAT OCCURS
TODAY. IF JKL SEES ANY RAIN TODAY...WHICH IT LOOKS LIKE WE
WILL...THERE IS AN OUTSIDE CHANCE OF IFR CONDITIONS FROM FOG BETWEEN
8 AND 12Z ON SUNDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AR
LONG TERM...GEOGERIAN
AVIATION...AR
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
951 PM CDT SUN AUG 3 2014
.UPDATE...
WATER VAPOR SATELLITE IMAGERY CONTINUE TO SHOW THE BASE OF TROUGH
OVER SOUTHWEST LOUISIANA AND DRYING NEAR THE JET MAX ON THE BACK
SIDE OF THE MAIN TROUGH. IR SATELLITE IMAGERY FINALLY SHOW SLIGHT
WARMING OF CLOUD TOPS NR BTR. WILL LINGER ISLD THUNDER IN GRIDS
THROUGH 3 AM MONDAY. OTHERWISE...PACKAGE IS OK OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 819 PM CDT SUN AUG 3 2014/
SOUNDING DISCUSSION...
THUNDERSTORM TO THE NORTHEAST OF THE STATION PUSHED AN OUTFLOW
BOUNDARY ACROSS THE STATION DURING THE LAUNCH PROCESS. ONCE
BALLOON GOT ABOVE 850 MB...IT GOT CAUGHT IN INFLOW TO STORM WHICH
CONTAMINATED MOISTURE FIELD. LITTLE OR NO CELL MOVEMENT INDICATED
BY SOUNDING WINDS...WHICH FITS RADAR TRENDS WELL. STORMS HAVE BEEN
PROPAGATING ON OUTFLOW INSTEAD OF MOVING. FLIGHT TERMINATED NEAR
THE MID-POINT OF THE LAKE PONTCHARTRAIN CAUSEWAY AT AN ALTITUDE OF
21.2 MILES.
PREV DISCUSSION... /ISSUED 402 PM CDT SUN AUG 3 2014/
DISCUSSION...
FRONTAL BOUNDARY AND WEAK SURFACE LOW THAT WERE STALLED ACROSS THE
FORECAST AREA HAVE DISSIPATED. SHOWERS AND THUNDERSTORMS HAVE TAKEN
A LITTLE LONGER TO GET GOING TODAY BUT RADAR SHOWS QUITE A FEW
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE EASTERN AND WESTERN
FRINGES OF THE CWA WHERE DEWPOINTS ARE GENERALLY IN THE LOWER TO MID
70S VS UPPER 60S ELSEWHERE. STORM MOTION PER THIS MORNINGS UPPER AIR
SOUNDING IS A WHOPPING 1 KT. SO DONT EXPECT ANY SHOWER OVERHEAD TO
MOVE AWAY FAST IN ANY WAY SHAPE OR FORM. IT WILL HAVE TO BASICALLY
RAIN ITSELF OUT. MINOR STREET FLOODING WILL BE POSSIBLE UNDER MORE
INTENSE CELLS. HRRR ONCE AGAIN OVER DOING COVERAGE TODAY BUT
STILL BELIEVE THE DIURNAL TREND ITS SHOWING WITH MOST ACTIVITY
DISSIPATED BY 04Z.
ECMWF AND GFS MODELS SHOW UPPER LEVEL TROUGH THAT CURRENTLY EXTENDS
SOUTH ACROSS THE ENTIRE GULF COAST WILL GRADUALLY LIFT NORTHEAST THE
REMAINDER OF THIS WEEK AND INTO NEXT WEEKEND WHILE RIDGE CENTERED TO
THE WEST BUILDS EAST. THIS ALONG WILL LEAVE CONVECTION DEVELOP TO
JUST DAYTIME HEATING AND THUS A RETURN TO MORE TYPICAL SUMMERTIME
SHOWERS AND STORMS. COVERAGE WILL REMAIN IN THE 20-40 PERCENT RANGE.
TEMPERATURES TO REMAIN AT OR SLIGHTLY BELOW NORMAL UNTIL AT LEAST
THE LATTER HALF OF THE WEEK.
MEFFER
AVIATION...
VFR CONDITIONS WILL GENERALLY PREVAIL AT THE TERMINALS THROUGH THE
TAF FORECAST PERIOD. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
WILL BE POSSIBLE...PRIMARILY DURING THE REMAINDER OF THE AFTERNOON
HOURS TODAY. 11
MARINE...
WEAK HIGH PRESSURE WILL BUILD OVER THE NORTH GULF DURING THE WEEK
RESULTING IN GENERALLY LIGHT AND AT TIMES VARIABLE WINDS AND LOW
SEAS. 11
DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
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 TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 71 91 71 90 / 20 30 20 30
BTR 72 90 72 91 / 20 30 20 30
ASD 72 91 72 88 / 30 40 20 30
MSY 76 90 76 89 / 30 40 20 30
GPT 76 90 77 92 / 30 40 20 30
PQL 71 91 72 90 / 30 40 20 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
819 PM CDT SUN AUG 3 2014
.SOUNDING DISCUSSION...
THUNDERSTORM TO THE NORTHEAST OF THE STATION PUSHED AN OUTFLOW
BOUNDARY ACROSS THE STATION DURING THE LAUNCH PROCESS. ONCE
BALLOON GOT ABOVE 850 MB...IT GOT CAUGHT IN INFLOW TO STORM WHICH
CONTAMINATED MOISTURE FIELD. LITTLE OR NO CELL MOVEMENT INDICATED
BY SOUNDING WINDS...WHICH FITS RADAR TRENDS WELL. STORMS HAVE BEEN
PROPAGATING ON OUTFLOW INSTEAD OF MOVING. FLIGHT TERMINATED NEAR
THE MID-POINT OF THE LAKE PONTCHARTRAIN CAUSEWAY AT AN ALTITUDE OF
21.2 MILES.
&&
.PREV DISCUSSION... /ISSUED 402 PM CDT SUN AUG 3 2014/
DISCUSSION...
FRONTAL BOUNDARY AND WEAK SURFACE LOW THAT WERE STALLED ACROSS THE
FORECAST AREA HAVE DISSIPATED. SHOWERS AND THUNDERSTORMS HAVE TAKEN
A LITTLE LONGER TO GET GOING TODAY BUT RADAR SHOWS QUITE A FEW
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG THE EASTERN AND WESTERN
FRINGES OF THE CWA WHERE DEWPOINTS ARE GENERALLY IN THE LOWER TO MID
70S VS UPPER 60S ELSEWHERE. STORM MOTION PER THIS MORNINGS UPPER AIR
SOUNDING IS A WHOPPING 1 KT. SO DONT EXPECT ANY SHOWER OVERHEAD TO
MOVE AWAY FAST IN ANY WAY SHAPE OR FORM. IT WILL HAVE TO BASICALLY
RAIN ITSELF OUT. MINOR STREET FLOODING WILL BE POSSIBLE UNDER MORE
INTENSE CELLS. HRRR ONCE AGAIN OVER DOING COVERAGE TODAY BUT
STILL BELIEVE THE DIURNAL TREND ITS SHOWING WITH MOST ACTIVITY
DISSIPATED BY 04Z.
ECMWF AND GFS MODELS SHOW UPPER LEVEL TROUGH THAT CURRENTLY EXTENDS
SOUTH ACROSS THE ENTIRE GULF COAST WILL GRADUALLY LIFT NORTHEAST THE
REMAINDER OF THIS WEEK AND INTO NEXT WEEKEND WHILE RIDGE CENTERED TO
THE WEST BUILDS EAST. THIS ALONG WILL LEAVE CONVECTION DEVELOP TO
JUST DAYTIME HEATING AND THUS A RETURN TO MORE TYPICAL SUMMERTIME
SHOWERS AND STORMS. COVERAGE WILL REMAIN IN THE 20-40 PERCENT RANGE.
TEMPERATURES TO REMAIN AT OR SLIGHTLY BELOW NORMAL UNTIL AT LEAST
THE LATTER HALF OF THE WEEK.
MEFFER
AVIATION...
VFR CONDITIONS WILL GENERALLY PREVAIL AT THE TERMINALS THROUGH THE
TAF FORECAST PERIOD. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
WILL BE POSSIBLE...PRIMARILY DURING THE REMAINDER OF THE AFTERNOON
HOURS TODAY. 11
MARINE...
WEAK HIGH PRESSURE WILL BUILD OVER THE NORTH GULF DURING THE WEEK
RESULTING IN GENERALLY LIGHT AND AT TIMES VARIABLE WINDS AND LOW
SEAS. 11
DECISION SUPPORT...
DSS CODE...GREEN.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...SLURRY SUPPORT.
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 TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 71 91 71 90 / 20 30 20 30
BTR 72 90 72 91 / 20 30 20 30
ASD 72 91 72 88 / 30 40 20 30
MSY 76 90 76 89 / 30 40 20 30
GPT 76 90 77 92 / 30 40 20 30
PQL 71 91 72 90 / 30 40 20 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
136 PM EDT SAT AUG 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM EDT SAT AUG 2 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR LKS BTWN CLOSED LO IN QUEBEC AND MEAN RDG OVER THE ROCKIES.
SHRTWV EMBEDDED IN THIS FLOW THAT BROUGHT SOME ISOLD SHOWERS/TS TO
THE U.P. LAST EVNG HAS PASSED TO THE E NOW...GIVING WAY TO A SHRTWV
RDG STRETCHING FM NW ONTARIO THRU NRN MN. THERE IS QUITE A CONTRAST
IN AIRMASSES OVER THE UPR LKS WITH 00Z RAOB FM GRB SHOWING PWAT UP
TO 1.07 INCH AND FAIRLY UNSTABLE LAPSE RATES/KINX 31 WHICH SUPPORTED
LAST EVNG`S CONVECTION. ON THE OTHER HAND...THE 00Z INL RAOB
REPRESENTATIVE OF THE INCOMING AIRMASS IS QUITE DRY AND STABLE...
WITH PWAT 0.47 INCH AND KINX 1. CLDS AND EVEN AN ISOLD SHOWER OR TWO
ASSOCIATED WITH THE EXITING SHRTWV ARE STILL OVER ERN UPR MI...BUT
SKIES ARE NOW MOCLR OVER THE W AND THRU NRN MN AS THE DRIER AIR/DNVA
AHEAD OF THE SHRTWV RDG ARE DOMINATING. SOME FOG HAS FORMED AT SOME
OF THE COOLER INTERIOR LOCATIONS. BEHIND THE SHRTWV RDG...THERE IS
ANOTHER DISTURBANCE NEAR LK WINNIPEG DROPPING SEWD ACCOMPANIED BY
SOME SHOWERS/TS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TEMPS TODAY AND THEN
SHOWER/TS CHCS TNGT AS DISTURBANCE NOW NEAR LK WINNIPEG APRCHS.
TODAY...SHRTWV RDG AXIS/ACCOMPANYING MID LVL DRY AIR IS FCST TO
DRIFT ACRS THE UPR LKS TDAY. DESPITE THE LARGE SCALE SUBSIDENCE/DRY
AIR SHOWN ON THE 00Z INL RAOB...A FEW OF THE MODELS PERSIST IN
GENERATING SOME SHOWERS OVER PORTIONS OF THE CWA. THIS PCPN SEEMS
RELATED TO SOME RELATIVELY WEAK H85 THETA E ADVCTN THAT IS FCST TO
ARRIVE IN THE AFTN AS THE H85 FLOW BACKS TOWARD THE WSW FOLLOWING
THE PASSAGE OF THE HI CENTER TO THE E. BUT GIVEN THE MID LVL
INVRN/DRY AIR IN THE FCST SDNGS THAT IS CONSISTENT WITH THE OBSVD
INL RAOB...OPTED TO KEEP UPR MI DRY AND JUST FCST SOME INCRSG HI
BASED CU/AC ACCOMPANYING THE MARGINAL MSTR RETURN. FCST H85 TEMPS UP
TO 14C OVER THE W BY 00Z AND MIXING TO H8 AS OBSVD ON THE INL RAOB
WL SUPPORT HI TEMPS REACHING THE LO 80S OVER THE INTERIOR W. THIS
DEEP MIXING WL ALLOW SFC DEWPTS TO MIX OUT AS LO AS ARND 50...
DROPPING MIN RH TO AS LO AS ARND 30 PCT. BUT LGT WINDS WL RESTRICT
ANY FIRE WX CONCERNS.
TNGT...AS SHRTWV NEAR LK WINNIPEG TRACKS ESEWD THRU NW ONTARIO...
COMMA TAIL FEATURE/AXIS OF H85-5 QVECTOR CNVGC/SOME MID LVL MOISTER
AIR IS FCST TO TRACK ACRS UPR MI. BUT SINCE THE SHARPER FORCING IS
FCST TO REMAIN TO THE N IN ONTARIO CLOSER TO THE SHRTWV TRACK... THE
INFLUX OF H85 THETA E IN ADVANCE OF THE ATTENDANT COLD FNT IS RATHER
WEAK/SSI FCST NO LOWER THAN ZERO TO -1C AND THESE DYNAMICS WL BE
ARRIVING DURING NOCTURNAL COOLING...SUSPECT THERE WL BE ONLY SOME
SCT SHOWERS MAINLY LATE OVER THE W CLOSER TO THE APRCHG COLD FNT.
GOING FCST APPEARS TO HAVE A GOOD HANDLE ON THE EXPECTED TRENDS AND
WL NEED LTL MODIFICATION.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 403 AM EDT SAT AUG 2 2014
SUNDAY...BROAD TROUGHING IS EXPECTED TO REMAIN IN PLACE THROUGH THIS
TIME PERIOD KEEPING TEMPERATURES NEAR TO SLIGHTLY COOLER THAN
NORMAL. DURING THE DAY SUNDAY...THE MAIN FOCUS WILL BE ON THE TIMING
OF A COLD FRONT POISED TO PUSH THROUGH THE UPPER GREAT LAKES REGION.
CURRENT MODEL TRENDS HAVE THE COLD FRONT ACROSS THE CENTRAL AND
EASTERN PORTIONS OF THE U.P. BY 18Z/03. THE ADDED LIFT ALONG WITH
INSTABILITY ACROSS THE REGION WILL ALLOW FOR INCREASING SHOWER AND
THUNDERSTORM COVERAGE ACROSS THE AREA...ESPECIALLY SUNDAY AFTERNOON
AND EVENING. MODELS ARE GENERALLY PAINTING AROUND 400-800 J/KG OF
INSTABILITY ACROSS THE AREA SUNDAY AFTERNOON AND EVENING WITH A FEW
HIGHER VALUES SOUTH CENTRAL. ROUGHLY 300-400 J/KG IS SHOWN IN THE
-10C TO -30C HAIL GROWTH LAYER. THE INSTABILITY MIGHT HAVE BEEN A
LITTLE BETTER BUT THE MAIN 500MB SHORTWAVE ROUNDING THE LARGE SCALE
TROUGH IS PROGGED TO LAG BEHIND THE FRONT AND REALLY DOES NOT SHOW
UP UNTIL THE LATE EVENING HOURS AS SHOWN BY ANALYZING 500MB
HEIGHTS/VORTICITY. MARGINALLY SEVERE HAIL WOULD LIKELY BE THE MAIN
THREAT AS OVERALL SHEAR VALUES REMAIN AROUND 20 KNOTS. OVERALL WIND
POTENTIAL LOOKS TO BE FAIRLY MINIMAL AS SOUNDINGS ARE FAIRLY MOIST
THROUGHOUT AND STORM MOTIONS ARE GENERALLY ON THE ORDER OF 20 KNOTS
FROM THE WEST.
SUNDAY NIGHT THROUGH MONDAY NIGHT...SHOWER AND THUNDERSTORM
POTENTIAL WILL DECREASE SUNDAY EVENING AS DAYTIME HEATING IS LOST
AND THE BETTER FORCING/MOISTURE ASSOCIATED WITH THE COLD FRONT
SHIFTS TO FAR SOUTHERN AND EASTERN UPPER MI BY 00Z/04 AND INTO THE
LOWER GREAT LAKES THROUGH MONDAY. THIS WILL BE ABOUT THE SAME TIME
THAT THE UPPER LEVEL SHORTWAVE BEGINS TO CATCH UP WITH THE FRONT
WHICH WILL SLOW DOWN OR NEARLY STALL OUT SOUTH AND EAST OF THE AREA.
ADDITIONALLY...A SURFACE HIGH WILL BEGIN BUILDING INTO THE AREA
MONDAY EVENING AND MONDAY NIGHT WITH FAIRLY DRY AIR KEEPING
CONDITIONS MAINLY DRY. IT LOOKS LIKE A COUPLE OF SHORT WAVES MAY TRY
TO PUSH THROUGH THE AREA...ESPECIALLY MONDAY AFTERNOON AND EVENING
AS SHOWN BY ANALYZING 500MB HEIGHTS ALONG WITH
VORTICITY...HOWEVER...THE LINGERING DRY AIR WILL LIKELY KEEP
CONDITIONS DRY.
TUESDAY THROUGH THURSDAY...A BROAD SURFACE HIGH AND FAIRLY DRY AIR
WILL LINGER ACROSS THE UPPER GREAT LAKE REGION THROUGH THIS TIME
FRAME KEEPING PRECIPITATION CHANCES VERY LIMITED ACROSS THE AREA.
ALOFT...THE U.P. WILL BE ON THE INFLECTION POINT TUESDAY MORNING
WITH A THE MAIN UPPER LEVEL TROUGH TO THE EAST AND UPPER LEVEL 500MB
RIDGE AXIS OVER THE EASTERN ROCKIES. THIS RIDGE AXIS IS PROGGED TO
CONTINUE SHIFTING EASTWARD...REACHING THE UPPER GREAT LAKES REGION
BY THURSDAY ALONG TEMPERATURES TO CONTINUE TO SLOWLY MODERATE.
THURSDAY NIGHT THROUGH FRIDAY...THE BROAD SURFACE HIGH WILL SLIP OFF
TO THE EAST OF THE GREAT LAKES REGION WHILE THE GFS/EC HAVE A
SURFACE LOW PRESSURE SYSTEM AND INCREASED DEEP LAYER MOISTURE
LIFTING NORTHWARD INTO THE REGION. AT THE SAME TIME THE MAIN UPPER
LEVEL RIDGE AXIS SLIDES TO THE EAST OF THE AREA STRETCHING FROM
QUEBEC SOUTHWARD INTO THE LOW GREAT LAKES. MODEL DIFFER ON EXACT
TIMING AND OVERALL INTENSITY OF THE SYSTEM WITH THE GFS BEING MORE
PROGRESSIVE...AS USUAL FOR THIS TIME OF YEAR...BRINGING THE
PRECIPITATION IN BY 12Z/08...WHILE THE EC HAVING MORE RUN TO RUN
CONTINUITY BRINGS THE PRECIPITATION CHANCES IN BY FRIDAY AFTERNOON.
WILL STICK MAINLY TO CONSENSUS...BUT TEND TO FAVOR THE EC A BIT MORE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 133 PM EDT SAT AUG 2 2014
CONTINUED QUIET WEATHER TODAY WITH HIGH PRESSURE IN CONTROL. A
WEAKENING COLD FRONT OVER THE CANADIAN PRAIRIES WILL MOVE THROUGH THE
AREA SUNDAY MORNING INTO EARLY AFTERNOON. NOT A GREAT DEAL OF
MOISTURE WITH THIS SYSTEM...HOWEVER FORCING WILL BE SUFFICIENT ENOUGH
FOR SOME SHOWERS LATE TONIGHT INTO SUNDAY MORNING AT CMX AND IWD.
WITH DAYTIME INSTABILITY...SAW MAY SEE SOME THUNDERSTORMS MOVING
NEARBY BY EARLY SUN AFTN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT AUG 2 2014
WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 15 KTS THROUGH WED. ALTHOUGH
THERE WILL BE PATCHY FOG WITH RELATIVELY HUMID AIR OVER THE CHILLY
LAKE WATERS INTO MON...NO WIDESPREAD DENSE FOG IS LIKELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...MRD
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
724 AM EDT SAT AUG 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM EDT SAT AUG 2 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR LKS BTWN CLOSED LO IN QUEBEC AND MEAN RDG OVER THE ROCKIES.
SHRTWV EMBEDDED IN THIS FLOW THAT BROUGHT SOME ISOLD SHOWERS/TS TO
THE U.P. LAST EVNG HAS PASSED TO THE E NOW...GIVING WAY TO A SHRTWV
RDG STRETCHING FM NW ONTARIO THRU NRN MN. THERE IS QUITE A CONTRAST
IN AIRMASSES OVER THE UPR LKS WITH 00Z RAOB FM GRB SHOWING PWAT UP
TO 1.07 INCH AND FAIRLY UNSTABLE LAPSE RATES/KINX 31 WHICH SUPPORTED
LAST EVNG`S CONVECTION. ON THE OTHER HAND...THE 00Z INL RAOB
REPRESENTATIVE OF THE INCOMING AIRMASS IS QUITE DRY AND STABLE...
WITH PWAT 0.47 INCH AND KINX 1. CLDS AND EVEN AN ISOLD SHOWER OR TWO
ASSOCIATED WITH THE EXITING SHRTWV ARE STILL OVER ERN UPR MI...BUT
SKIES ARE NOW MOCLR OVER THE W AND THRU NRN MN AS THE DRIER AIR/DNVA
AHEAD OF THE SHRTWV RDG ARE DOMINATING. SOME FOG HAS FORMED AT SOME
OF THE COOLER INTERIOR LOCATIONS. BEHIND THE SHRTWV RDG...THERE IS
ANOTHER DISTURBANCE NEAR LK WINNIPEG DROPPING SEWD ACCOMPANIED BY
SOME SHOWERS/TS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TEMPS TODAY AND THEN
SHOWER/TS CHCS TNGT AS DISTURBANCE NOW NEAR LK WINNIPEG APRCHS.
TODAY...SHRTWV RDG AXIS/ACCOMPANYING MID LVL DRY AIR IS FCST TO
DRIFT ACRS THE UPR LKS TDAY. DESPITE THE LARGE SCALE SUBSIDENCE/DRY
AIR SHOWN ON THE 00Z INL RAOB...A FEW OF THE MODELS PERSIST IN
GENERATING SOME SHOWERS OVER PORTIONS OF THE CWA. THIS PCPN SEEMS
RELATED TO SOME RELATIVELY WEAK H85 THETA E ADVCTN THAT IS FCST TO
ARRIVE IN THE AFTN AS THE H85 FLOW BACKS TOWARD THE WSW FOLLOWING
THE PASSAGE OF THE HI CENTER TO THE E. BUT GIVEN THE MID LVL
INVRN/DRY AIR IN THE FCST SDNGS THAT IS CONSISTENT WITH THE OBSVD
INL RAOB...OPTED TO KEEP UPR MI DRY AND JUST FCST SOME INCRSG HI
BASED CU/AC ACCOMPANYING THE MARGINAL MSTR RETURN. FCST H85 TEMPS UP
TO 14C OVER THE W BY 00Z AND MIXING TO H8 AS OBSVD ON THE INL RAOB
WL SUPPORT HI TEMPS REACHING THE LO 80S OVER THE INTERIOR W. THIS
DEEP MIXING WL ALLOW SFC DEWPTS TO MIX OUT AS LO AS ARND 50...
DROPPING MIN RH TO AS LO AS ARND 30 PCT. BUT LGT WINDS WL RESTRICT
ANY FIRE WX CONCERNS.
TNGT...AS SHRTWV NEAR LK WINNIPEG TRACKS ESEWD THRU NW ONTARIO...
COMMA TAIL FEATURE/AXIS OF H85-5 QVECTOR CNVGC/SOME MID LVL MOISTER
AIR IS FCST TO TRACK ACRS UPR MI. BUT SINCE THE SHARPER FORCING IS
FCST TO REMAIN TO THE N IN ONTARIO CLOSER TO THE SHRTWV TRACK... THE
INFLUX OF H85 THETA E IN ADVANCE OF THE ATTENDANT COLD FNT IS RATHER
WEAK/SSI FCST NO LOWER THAN ZERO TO -1C AND THESE DYNAMICS WL BE
ARRIVING DURING NOCTURNAL COOLING...SUSPECT THERE WL BE ONLY SOME
SCT SHOWERS MAINLY LATE OVER THE W CLOSER TO THE APRCHG COLD FNT.
GOING FCST APPEARS TO HAVE A GOOD HANDLE ON THE EXPECTED TRENDS AND
WL NEED LTL MODIFICATION.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 403 AM EDT SAT AUG 2 2014
SUNDAY...BROAD TROUGHING IS EXPECTED TO REMAIN IN PLACE THROUGH THIS
TIME PERIOD KEEPING TEMPERATURES NEAR TO SLIGHTLY COOLER THAN
NORMAL. DURING THE DAY SUNDAY...THE MAIN FOCUS WILL BE ON THE TIMING
OF A COLD FRONT POISED TO PUSH THROUGH THE UPPER GREAT LAKES REGION.
CURRENT MODEL TRENDS HAVE THE COLD FRONT ACROSS THE CENTRAL AND
EASTERN PORTIONS OF THE U.P. BY 18Z/03. THE ADDED LIFT ALONG WITH
INSTABILITY ACROSS THE REGION WILL ALLOW FOR INCREASING SHOWER AND
THUNDERSTORM COVERAGE ACROSS THE AREA...ESPECIALLY SUNDAY AFTERNOON
AND EVENING. MODELS ARE GENERALLY PAINTING AROUND 400-800 J/KG OF
INSTABILITY ACROSS THE AREA SUNDAY AFTERNOON AND EVENING WITH A FEW
HIGHER VALUES SOUTH CENTRAL. ROUGHLY 300-400 J/KG IS SHOWN IN THE
-10C TO -30C HAIL GROWTH LAYER. THE INSTABILITY MIGHT HAVE BEEN A
LITTLE BETTER BUT THE MAIN 500MB SHORTWAVE ROUNDING THE LARGE SCALE
TROUGH IS PROGGED TO LAG BEHIND THE FRONT AND REALLY DOES NOT SHOW
UP UNTIL THE LATE EVENING HOURS AS SHOWN BY ANALYZING 500MB
HEIGHTS/VORTICITY. MARGINALLY SEVERE HAIL WOULD LIKELY BE THE MAIN
THREAT AS OVERALL SHEAR VALUES REMAIN AROUND 20 KNOTS. OVERALL WIND
POTENTIAL LOOKS TO BE FAIRLY MINIMAL AS SOUNDINGS ARE FAIRLY MOIST
THROUGHOUT AND STORM MOTIONS ARE GENERALLY ON THE ORDER OF 20 KNOTS
FROM THE WEST.
SUNDAY NIGHT THROUGH MONDAY NIGHT...SHOWER AND THUNDERSTORM
POTENTIAL WILL DECREASE SUNDAY EVENING AS DAYTIME HEATING IS LOST
AND THE BETTER FORCING/MOISTURE ASSOCIATED WITH THE COLD FRONT
SHIFTS TO FAR SOUTHERN AND EASTERN UPPER MI BY 00Z/04 AND INTO THE
LOWER GREAT LAKES THROUGH MONDAY. THIS WILL BE ABOUT THE SAME TIME
THAT THE UPPER LEVEL SHORTWAVE BEGINS TO CATCH UP WITH THE FRONT
WHICH WILL SLOW DOWN OR NEARLY STALL OUT SOUTH AND EAST OF THE AREA.
ADDITIONALLY...A SURFACE HIGH WILL BEGIN BUILDING INTO THE AREA
MONDAY EVENING AND MONDAY NIGHT WITH FAIRLY DRY AIR KEEPING
CONDITIONS MAINLY DRY. IT LOOKS LIKE A COUPLE OF SHORT WAVES MAY TRY
TO PUSH THROUGH THE AREA...ESPECIALLY MONDAY AFTERNOON AND EVENING
AS SHOWN BY ANALYZING 500MB HEIGHTS ALONG WITH
VORTICITY...HOWEVER...THE LINGERING DRY AIR WILL LIKELY KEEP
CONDITIONS DRY.
TUESDAY THROUGH THURSDAY...A BROAD SURFACE HIGH AND FAIRLY DRY AIR
WILL LINGER ACROSS THE UPPER GREAT LAKE REGION THROUGH THIS TIME
FRAME KEEPING PRECIPITATION CHANCES VERY LIMITED ACROSS THE AREA.
ALOFT...THE U.P. WILL BE ON THE INFLECTION POINT TUESDAY MORNING
WITH A THE MAIN UPPER LEVEL TROUGH TO THE EAST AND UPPER LEVEL 500MB
RIDGE AXIS OVER THE EASTERN ROCKIES. THIS RIDGE AXIS IS PROGGED TO
CONTINUE SHIFTING EASTWARD...REACHING THE UPPER GREAT LAKES REGION
BY THURSDAY ALONG TEMPERATURES TO CONTINUE TO SLOWLY MODERATE.
THURSDAY NIGHT THROUGH FRIDAY...THE BROAD SURFACE HIGH WILL SLIP OFF
TO THE EAST OF THE GREAT LAKES REGION WHILE THE GFS/EC HAVE A
SURFACE LOW PRESSURE SYSTEM AND INCREASED DEEP LAYER MOISTURE
LIFTING NORTHWARD INTO THE REGION. AT THE SAME TIME THE MAIN UPPER
LEVEL RIDGE AXIS SLIDES TO THE EAST OF THE AREA STRETCHING FROM
QUEBEC SOUTHWARD INTO THE LOW GREAT LAKES. MODEL DIFFER ON EXACT
TIMING AND OVERALL INTENSITY OF THE SYSTEM WITH THE GFS BEING MORE
PROGRESSIVE...AS USUAL FOR THIS TIME OF YEAR...BRINGING THE
PRECIPITATION IN BY 12Z/08...WHILE THE EC HAVING MORE RUN TO RUN
CONTINUITY BRINGS THE PRECIPITATION CHANCES IN BY FRIDAY AFTERNOON.
WILL STICK MAINLY TO CONSENSUS...BUT TEND TO FAVOR THE EC A BIT MORE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 723 AM EDT SAT AUG 2 2014
DRY HI PRES MOVING THRU THE UPR LKS WL BRING VFR CONDITIONS AND LGT
WINDS TO THE TAF SITES TDAY. ALTHOUGH MID CLDS IN ADVANCE OF AN
APRCHG DISTURBANCE/COLD FNT WL ARRIVE TNGT...THE LLVLS SHOULD REMAIN
SUFFICIENTLY DRY TO ENSURE PREDOMINANT VFR CONDITIONS EVEN IF SOME
-SHRA ALSO IMPACT MAINLY CMX AND IWD AFT 06Z.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT AUG 2 2014
WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 15 KTS THROUGH WED. ALTHOUGH
THERE WILL BE PATCHY FOG WITH RELATIVELY HUMID AIR OVER THE CHILLY
LAKE WATERS INTO MON...NO WIDESPREAD DENSE FOG IS LIKELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
404 AM EDT SAT AUG 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM EDT SAT AUG 2 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR LKS BTWN CLOSED LO IN QUEBEC AND MEAN RDG OVER THE ROCKIES.
SHRTWV EMBEDDED IN THIS FLOW THAT BROUGHT SOME ISOLD SHOWERS/TS TO
THE U.P. LAST EVNG HAS PASSED TO THE E NOW...GIVING WAY TO A SHRTWV
RDG STRETCHING FM NW ONTARIO THRU NRN MN. THERE IS QUITE A CONTRAST
IN AIRMASSES OVER THE UPR LKS WITH 00Z RAOB FM GRB SHOWING PWAT UP
TO 1.07 INCH AND FAIRLY UNSTABLE LAPSE RATES/KINX 31 WHICH SUPPORTED
LAST EVNG`S CONVECTION. ON THE OTHER HAND...THE 00Z INL RAOB
REPRESENTATIVE OF THE INCOMING AIRMASS IS QUITE DRY AND STABLE...
WITH PWAT 0.47 INCH AND KINX 1. CLDS AND EVEN AN ISOLD SHOWER OR TWO
ASSOCIATED WITH THE EXITING SHRTWV ARE STILL OVER ERN UPR MI...BUT
SKIES ARE NOW MOCLR OVER THE W AND THRU NRN MN AS THE DRIER AIR/DNVA
AHEAD OF THE SHRTWV RDG ARE DOMINATING. SOME FOG HAS FORMED AT SOME
OF THE COOLER INTERIOR LOCATIONS. BEHIND THE SHRTWV RDG...THERE IS
ANOTHER DISTURBANCE NEAR LK WINNIPEG DROPPING SEWD ACCOMPANIED BY
SOME SHOWERS/TS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TEMPS TODAY AND THEN
SHOWER/TS CHCS TNGT AS DISTURBANCE NOW NEAR LK WINNIPEG APRCHS.
TODAY...SHRTWV RDG AXIS/ACCOMPANYING MID LVL DRY AIR IS FCST TO
DRIFT ACRS THE UPR LKS TDAY. DESPITE THE LARGE SCALE SUBSIDENCE/DRY
AIR SHOWN ON THE 00Z INL RAOB...A FEW OF THE MODELS PERSIST IN
GENERATING SOME SHOWERS OVER PORTIONS OF THE CWA. THIS PCPN SEEMS
RELATED TO SOME RELATIVELY WEAK H85 THETA E ADVCTN THAT IS FCST TO
ARRIVE IN THE AFTN AS THE H85 FLOW BACKS TOWARD THE WSW FOLLOWING
THE PASSAGE OF THE HI CENTER TO THE E. BUT GIVEN THE MID LVL
INVRN/DRY AIR IN THE FCST SDNGS THAT IS CONSISTENT WITH THE OBSVD
INL RAOB...OPTED TO KEEP UPR MI DRY AND JUST FCST SOME INCRSG HI
BASED CU/AC ACCOMPANYING THE MARGINAL MSTR RETURN. FCST H85 TEMPS UP
TO 14C OVER THE W BY 00Z AND MIXING TO H8 AS OBSVD ON THE INL RAOB
WL SUPPORT HI TEMPS REACHING THE LO 80S OVER THE INTERIOR W. THIS
DEEP MIXING WL ALLOW SFC DEWPTS TO MIX OUT AS LO AS ARND 50...
DROPPING MIN RH TO AS LO AS ARND 30 PCT. BUT LGT WINDS WL RESTRICT
ANY FIRE WX CONCERNS.
TNGT...AS SHRTWV NEAR LK WINNIPEG TRACKS ESEWD THRU NW ONTARIO...
COMMA TAIL FEATURE/AXIS OF H85-5 QVECTOR CNVGC/SOME MID LVL MOISTER
AIR IS FCST TO TRACK ACRS UPR MI. BUT SINCE THE SHARPER FORCING IS
FCST TO REMAIN TO THE N IN ONTARIO CLOSER TO THE SHRTWV TRACK... THE
INFLUX OF H85 THETA E IN ADVANCE OF THE ATTENDANT COLD FNT IS RATHER
WEAK/SSI FCST NO LOWER THAN ZERO TO -1C AND THESE DYNAMICS WL BE
ARRIVING DURING NOCTURNAL COOLING...SUSPECT THERE WL BE ONLY SOME
SCT SHOWERS MAINLY LATE OVER THE W CLOSER TO THE APRCHG COLD FNT.
GOING FCST APPEARS TO HAVE A GOOD HANDLE ON THE EXPECTED TRENDS AND
WL NEED LTL MODIFICATION.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 403 AM EDT SAT AUG 2 2014
SUNDAY...BROAD TROUGHING IS EXPECTED TO REMAIN IN PLACE THROUGH THIS
TIME PERIOD KEEPING TEMPERATURES NEAR TO SLIGHTLY COOLER THAN
NORMAL. DURING THE DAY SUNDAY...THE MAIN FOCUS WILL BE ON THE TIMING
OF A COLD FRONT POISED TO PUSH THROUGH THE UPPER GREAT LAKES REGION.
CURRENT MODEL TRENDS HAVE THE COLD FRONT ACROSS THE CENTRAL AND
EASTERN PORTIONS OF THE U.P. BY 18Z/03. THE ADDED LIFT ALONG WITH
INSTABILITY ACROSS THE REGION WILL ALLOW FOR INCREASING SHOWER AND
THUNDERSTORM COVERAGE ACROSS THE AREA...ESPECIALLY SUNDAY AFTERNOON
AND EVENING. MODELS ARE GENERALLY PAINTING AROUND 400-800 J/KG OF
INSTABILITY ACROSS THE AREA SUNDAY AFTERNOON AND EVENING WITH A FEW
HIGHER VALUES SOUTH CENTRAL. ROUGHLY 300-400 J/KG IS SHOWN IN THE
-10C TO -30C HAIL GROWTH LAYER. THE INSTABILITY MIGHT HAVE BEEN A
LITTLE BETTER BUT THE MAIN 500MB SHORTWAVE ROUNDING THE LARGE SCALE
TROUGH IS PROGGED TO LAG BEHIND THE FRONT AND REALLY DOES NOT SHOW
UP UNTIL THE LATE EVENING HOURS AS SHOWN BY ANALYZING 500MB
HEIGHTS/VORTICITY. MARGINALLY SEVERE HAIL WOULD LIKELY BE THE MAIN
THREAT AS OVERALL SHEAR VALUES REMAIN AROUND 20 KNOTS. OVERALL WIND
POTENTIAL LOOKS TO BE FAIRLY MINIMAL AS SOUNDINGS ARE FAIRLY MOIST
THROUGHOUT AND STORM MOTIONS ARE GENERALLY ON THE ORDER OF 20 KNOTS
FROM THE WEST.
SUNDAY NIGHT THROUGH MONDAY NIGHT...SHOWER AND THUNDERSTORM
POTENTIAL WILL DECREASE SUNDAY EVENING AS DAYTIME HEATING IS LOST
AND THE BETTER FORCING/MOISTURE ASSOCIATED WITH THE COLD FRONT
SHIFTS TO FAR SOUTHERN AND EASTERN UPPER MI BY 00Z/04 AND INTO THE
LOWER GREAT LAKES THROUGH MONDAY. THIS WILL BE ABOUT THE SAME TIME
THAT THE UPPER LEVEL SHORTWAVE BEGINS TO CATCH UP WITH THE FRONT
WHICH WILL SLOW DOWN OR NEARLY STALL OUT SOUTH AND EAST OF THE AREA.
ADDITIONALLY...A SURFACE HIGH WILL BEGIN BUILDING INTO THE AREA
MONDAY EVENING AND MONDAY NIGHT WITH FAIRLY DRY AIR KEEPING
CONDITIONS MAINLY DRY. IT LOOKS LIKE A COUPLE OF SHORT WAVES MAY TRY
TO PUSH THROUGH THE AREA...ESPECIALLY MONDAY AFTERNOON AND EVENING
AS SHOWN BY ANALYZING 500MB HEIGHTS ALONG WITH
VORTICITY...HOWEVER...THE LINGERING DRY AIR WILL LIKELY KEEP
CONDITIONS DRY.
TUESDAY THROUGH THURSDAY...A BROAD SURFACE HIGH AND FAIRLY DRY AIR
WILL LINGER ACROSS THE UPPER GREAT LAKE REGION THROUGH THIS TIME
FRAME KEEPING PRECIPITATION CHANCES VERY LIMITED ACROSS THE AREA.
ALOFT...THE U.P. WILL BE ON THE INFLECTION POINT TUESDAY MORNING
WITH A THE MAIN UPPER LEVEL TROUGH TO THE EAST AND UPPER LEVEL 500MB
RIDGE AXIS OVER THE EASTERN ROCKIES. THIS RIDGE AXIS IS PROGGED TO
CONTINUE SHIFTING EASTWARD...REACHING THE UPPER GREAT LAKES REGION
BY THURSDAY ALONG TEMPERATURES TO CONTINUE TO SLOWLY MODERATE.
THURSDAY NIGHT THROUGH FRIDAY...THE BROAD SURFACE HIGH WILL SLIP OFF
TO THE EAST OF THE GREAT LAKES REGION WHILE THE GFS/EC HAVE A
SURFACE LOW PRESSURE SYSTEM AND INCREASED DEEP LAYER MOISTURE
LIFTING NORTHWARD INTO THE REGION. AT THE SAME TIME THE MAIN UPPER
LEVEL RIDGE AXIS SLIDES TO THE EAST OF THE AREA STRETCHING FROM
QUEBEC SOUTHWARD INTO THE LOW GREAT LAKES. MODEL DIFFER ON EXACT
TIMING AND OVERALL INTENSITY OF THE SYSTEM WITH THE GFS BEING MORE
PROGRESSIVE...AS USUAL FOR THIS TIME OF YEAR...BRINGING THE
PRECIPITATION IN BY 12Z/08...WHILE THE EC HAVING MORE RUN TO RUN
CONTINUITY BRINGS THE PRECIPITATION CHANCES IN BY FRIDAY AFTERNOON.
WILL STICK MAINLY TO CONSENSUS...BUT TEND TO FAVOR THE EC A BIT MORE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 122 AM EDT SAT AUG 2 2014
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL THREE TAF SITES OVER
THE NEXT 24 HOURS. THERE WILL BE SOME INCREASE IN SOME MID CLOUDS
OVER THE WRN TAF SITES TOWARD SAT EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT AUG 2 2014
WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 15 KTS THROUGH WED. ALTHOUGH
THERE WILL BE PATCHY FOG WITH RELATIVELY HUMID AIR OVER THE CHILLY
LAKE WATERS INTO MON...NO WIDESPREAD DENSE FOG IS LIKELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
355 AM EDT SAT AUG 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM EDT SAT AUG 2 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALF OVER
THE UPR LKS BTWN CLOSED LO IN QUEBEC AND MEAN RDG OVER THE ROCKIES.
SHRTWV EMBEDDED IN THIS FLOW THAT BROUGHT SOME ISOLD SHOWERS/TS TO
THE U.P. LAST EVNG HAS PASSED TO THE E NOW...GIVING WAY TO A SHRTWV
RDG STRETCHING FM NW ONTARIO THRU NRN MN. THERE IS QUITE A CONTRAST
IN AIRMASSES OVER THE UPR LKS WITH 00Z RAOB FM GRB SHOWING PWAT UP
TO 1.07 INCH AND FAIRLY UNSTABLE LAPSE RATES/KINX 31 WHICH SUPPORTED
LAST EVNG`S CONVECTION. ON THE OTHER HAND...THE 00Z INL RAOB
REPRESENTATIVE OF THE INCOMING AIRMASS IS QUITE DRY AND STABLE...
WITH PWAT 0.47 INCH AND KINX 1. CLDS AND EVEN AN ISOLD SHOWER OR TWO
ASSOCIATED WITH THE EXITING SHRTWV ARE STILL OVER ERN UPR MI...BUT
SKIES ARE NOW MOCLR OVER THE W AND THRU NRN MN AS THE DRIER AIR/DNVA
AHEAD OF THE SHRTWV RDG ARE DOMINATING. SOME FOG HAS FORMED AT SOME
OF THE COOLER INTERIOR LOCATIONS. BEHIND THE SHRTWV RDG...THERE IS
ANOTHER DISTURBANCE NEAR LK WINNIPEG DROPPING SEWD ACCOMPANIED BY
SOME SHOWERS/TS.
MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE TEMPS TODAY AND THEN
SHOWER/TS CHCS TNGT AS DISTURBANCE NOW NEAR LK WINNIPEG APRCHS.
TODAY...SHRTWV RDG AXIS/ACCOMPANYING MID LVL DRY AIR IS FCST TO
DRIFT ACRS THE UPR LKS TDAY. DESPITE THE LARGE SCALE SUBSIDENCE/DRY
AIR SHOWN ON THE 00Z INL RAOB...A FEW OF THE MODELS PERSIST IN
GENERATING SOME SHOWERS OVER PORTIONS OF THE CWA. THIS PCPN SEEMS
RELATED TO SOME RELATIVELY WEAK H85 THETA E ADVCTN THAT IS FCST TO
ARRIVE IN THE AFTN AS THE H85 FLOW BACKS TOWARD THE WSW FOLLOWING
THE PASSAGE OF THE HI CENTER TO THE E. BUT GIVEN THE MID LVL
INVRN/DRY AIR IN THE FCST SDNGS THAT IS CONSISTENT WITH THE OBSVD
INL RAOB...OPTED TO KEEP UPR MI DRY AND JUST FCST SOME INCRSG HI
BASED CU/AC ACCOMPANYING THE MARGINAL MSTR RETURN. FCST H85 TEMPS UP
TO 14C OVER THE W BY 00Z AND MIXING TO H8 AS OBSVD ON THE INL RAOB
WL SUPPORT HI TEMPS REACHING THE LO 80S OVER THE INTERIOR W. THIS
DEEP MIXING WL ALLOW SFC DEWPTS TO MIX OUT AS LO AS ARND 50...
DROPPING MIN RH TO AS LO AS ARND 30 PCT. BUT LGT WINDS WL RESTRICT
ANY FIRE WX CONCERNS.
TNGT...AS SHRTWV NEAR LK WINNIPEG TRACKS ESEWD THRU NW ONTARIO...
COMMA TAIL FEATURE/AXIS OF H85-5 QVECTOR CNVGC/SOME MID LVL MOISTER
AIR IS FCST TO TRACK ACRS UPR MI. BUT SINCE THE SHARPER FORCING IS
FCST TO REMAIN TO THE N IN ONTARIO CLOSER TO THE SHRTWV TRACK... THE
INFLUX OF H85 THETA E IN ADVANCE OF THE ATTENDANT COLD FNT IS RATHER
WEAK/SSI FCST NO LOWER THAN ZERO TO -1C AND THESE DYNAMICS WL BE
ARRIVING DURING NOCTURNAL COOLING...SUSPECT THERE WL BE ONLY SOME
SCT SHOWERS MAINLY LATE OVER THE W CLOSER TO THE APRCHG COLD FNT.
GOING FCST APPEARS TO HAVE A GOOD HANDLE ON THE EXPECTED TRENDS AND
WL NEED LTL MODIFICATION.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 325 PM EDT FRI AUG 1 2014
THE LATTER PORTION OF THE WEEKEND BEGINS WITH AN UPPER LEVEL TROUGH
OVER THE GREAT LAKES REGION...AND A RIDGE ANCHORED FIRMLY OVER THE
WESTERN UNITED STATES. THIS PUTS UPPER MICHIGAN IN SOMEWHAT ZONAL
FLOW BEFORE A SHORTWAVE SWEEPS INTO ONTARIO SATURDAY AFTERNOON. THE
GFS/NAM ARE STILL PUSHING THE ASSOCIATED COLD FRONT THROUGH THE CWA
SLIGHTLY EARLIER THAN THE GEM/ECMWF. SHOULD THE FRONT COME IN
EARLIER AS THE GFS/NAM SUGGEST...EXPECT PRECIPITATION TO ENTER THE
WESTERN CWA BY ABOUT 9Z. SHOULD THE ECMWF/GEM SOLUTION BE
CORRECT...TIMING WILL BE SLIGHTLY LATER FOR PRECIPITATION...LIKELY
AROUND 12Z-15Z. WILL GO WITH A COMPROMISE FOR POPS TO RESOLVE THE
MINOR TIMING DIFFERENCES FOR NOW...THOUGH I LEAN MORE TOWARDS THE
SLOWER TIMING OF THE ECMWF/GEM.
AS FAR AS THUNDERSTORM POTENTIAL...BEST CHANCES LOOK TO BE EARLY
SUNDAY AFTERNOON WITH DAYTIME HEATING AS THE FRONT ROLLS THROUGH.
THE BEST INSTABILITY...AROUND 1500-2000 J/KG...LINGERS ALONG THE WI
BORDER. OTHERWISE...MOST OF THE WESTERN AND NORTH CENTRAL CWA SEES
AROUND 500 J/KG. THE ECMWF/GEM KEEP LOWER INSTABILITY ACROSS THE
EAST...LESS THAN 100 J/KG....BUT THE GFS BRINGS THE HIGHER
INSTABILITY OF AROUND 1500 J/KG INTO THE INLAND EAST...AND GENERATES
CONVECTION ALONG THE LAKE BREEZE BOUNDARY. WILL KEEP SCHC THUNDER IN
THAT AREA FOR NOW GIVEN THE DISCREPENCY. AS FAR AS SHEAR
GOES...0-6KM FOR MOST OF THE CWA IS AROUND 15-20 KNOTS...SO WOULD
NOT BE SURPRISED TO SEE A COUPLE STRONGER STORMS DEVELOP IF THE
FRONT PASSES THROUGH WHEN THE BEST INSTABILITY IS IN PLACE.
THUNDERSTORM POSSIBILITY ENDS WITH DAYTIME HEATING...BUT WILL KEEP
CHANCES FOR PRECIPITATION IN THE EAST WITH THE PASSING FRONT...AGAIN
GOING WITH THE CONSENSUS FOR POPS GIVEN THE DISCREPANCIES BETWEEN
NAM/GFS AND THE ECMWF/GEM.
MONDAY THE RIDGE BUILDING ACROSS THE WESTERN CONUS AND CANADIAN
PRAIRIE WILL EXPAND INTO THE WESTERN CWA...WITH SURFACE HIGH
PRESSURE FORCING ITS WAY INTO UPPER MI. MODELS ALSO DEVELOP A LOW
PRESSURE SYSTEM OVER NEBRASKA/SOUTH DAKOTA THAT DRAPES A WARM FRONT
ACROSS WI AND IOWA. MODEL DIFFERENCES AGAIN BRING COMPLICATION TO
THE FORECAST...WITH THE GFS/GEM HAVING STRONGER SURFACE HIGH
PRESSURE THAT KEEPS THE LOW/WARM FRONT FURTHER SOUTH...AND ALL
PRECIPITATION ONLY UP TO THE WI BORDER. THE ECMWF BRINGS THE LOW AND
WARM FRONT FURTHER NORTH...AND GENERATES CONVECTION MONDAY AFTERNOON
INTO SOUTHERN UPPER MI. WILL KEEP GOING SLIGHT CHANCE POPS/CONSENSUS
FORECAST NEAR THE WI BORDER/SOUTH CENTRAL U.P. FOR NOW.
STRONG SFC HIGH PRESSURE CENTERS ITSELF OVER THE GREAT LAKES FOR
TUESDAY AND LINGERS OVER THROUGH WEDNESDAY...THOUGH AT UPPER LEVELS
THE TROUGH STILL LINGERS AND KEEPS 850MB TEMPS AROUND 10-12C. THIS
WILL KEEP THINGS A BIT COOLER THAN NORMAL...ESPECIALLY WITH LIGHT
WINDS ALLOWING FOR LAKE BREEZE DEVELOPMENT. OVERALL...EXPECT A DRY
FORECAST FOR THESE DAYS WITH HIGHS IN THE UPPER 60S NEAR THE
LAKE...AND THE LOW TO MID 70S INLAND.
IN THE MEANTIME...A POTENT 500MB SHORTWAVE DEVELOPS OVER THE
CANADIAN PRAIRIES WEDNESDAY MORNING DIGS DEEPER INTO THE NORTHERN
PLAINS BY WEDNESDAY EVENING. THIS AMPLIFIES THE RIDGE AND SHIFTS IT
EASTWARD FROM THE UPPER MISSISSIPPI VALLEY WEDNESDAY INTO UPPER
MICHIGAN FOR THURSDAY. SFC LOW PRESSURE DEVELOPS WITH THIS
SHORTWAVE...THOUGH THE ECMWF/GFS ONCE AGAIN DIFFER ON THE PLACEMENT
AND MOVEMENT OF THIS LOW. THE GFS DEVELOPS IT OVER THE NORTHERN
PLAINS AND MOVES IT INTO ONTARIO...AND THE ECMWF DEVELOPS IT OVER
IOWA AND MOVES IT INTO WISCONSIN. WILL STICK WITH CONSENSUS POPS YET
AGAIN THURSDAY INTO FRIDAY DUE TO THE LARGE DIFFERENCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 122 AM EDT SAT AUG 2 2014
VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL THREE TAF SITES OVER
THE NEXT 24 HOURS. THERE WILL BE SOME INCREASE IN SOME MID CLOUDS
OVER THE WRN TAF SITES TOWARD SAT EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 354 AM EDT SAT AUG 2 2014
WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 15 KTS THROUGH WED. ALTHOUGH
THERE WILL BE PATCHY FOG WITH RELATIVELY HUMID AIR OVER THE CHILLY
LAKE WATERS INTO MON...NO WIDESPREAD DENSE FOG IS LIKELY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
927 PM CDT Sun Aug 3 2014
.UPDATE:
Issued at 926 PM CDT Sun Aug 3 2014
Isolated thunderstorms have recently developed over western
Missouri in an area of 925-850mb moisture convergence. RAP shows
this area of forcing will spread eastward into central and
northeast Missouri after midnight. Going forecast handles this
trend well, so will keep chance of thunderstorms going in these
areas with slight chances all the way east to the St. Louis metro
area. Temperature and sky trends also match going forecast.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 343 PM CDT Sun Aug 3 2014
The primary forecast issue for late this afternoon through the
overnight hours is convective trends. Ongoing isolated to scattered
SHRA/TSRA along an outflow boundary will probably keep percolating
late this afternoon in central MO, then diminish tonight with the
loss of daytime heating. Meanwhile, a vort max will dive south out
of the Dakotas, providing a source of lift for new development later
tonight. The 12z model runs did not seem to accurately capture the
strength of the vort max based on its presentation on today`s water
vapor imagery. The western edge of the aforementioned outflow
boundary was very pronounced on afternoon visible satellite imagery,
and initial thoughts are that scattered SHRA/TSRA could develop late
tonight in eastern KS or western/central MO due to lift over this
boundary occurring ahead of the approaching short wave from its weak
westerly LLJ. Limited moisture would tend to limit the coverage of
any precip which develops. Overnight lows should be similar to last
night in most locations, except a bit warmer due to increased
mid/high clouds after 06z which will interfere with radiational
cooling processes.
Kanofsky
.LONG TERM: (Monday through Next Sunday)
Issued at 343 PM CDT Sun Aug 3 2014
(Monday - Tuesday)
Area of showers and storms from overnight convection is possible to linger
through the morning hours over northern and western portions of
the forecast area. If such an area exists early tomorrow
morning...it should slide south and east with the mid to upper-
level flow pattern. Isolated to scattered convection is possible
tomorrow afternoon as the ams destabilizes across the
area...especially across northern sections of the forecast area in
close proximity to warm frontal boundary/wind shift and area of
diffluence aloft. A few of these storms may be strong due to the
degree of instability forecast...however any kind of organized
strong storms looks unlikely due to very weak deep layer shear
(aob 25 knots).
Frontal boundary is expected to sag south a bit on Monday night and Tuesday
along with the continued chances of showers and thunderstorms. Lows Monday
night look to be near seasonal norms or slightly warmer than the previous
nights due to increased cloud cover and southerly flow across portions of
the area.
(Wednesday - Sunday)
Unfortunately...still plenty of uncertainty regarding PoPs and effects on
temperatures for the rest of the extended period. GFS/CMC are now much
further north with MCS progged for Wednesday compared to more consistent
ECMWF. Did not make too many changes Wednesday on compared to previous
forecast as GFS/CMC do look too far north and east with convection not only
on Wednesday but also through the work week looking at mid/upper level flow
pattern and NW-SE oriented baroclinic zone. Highest threat of rainfall still
looks to be somewhere in the Wednesday night through early Saturday time frame
but bountiful uncertainity/disagreement in track/timing on indiviudal
shortwaves precludes pin pointing any time period(s) with much higher PoPs
than previously forecast. Still does look like a wet and active pattern
for the mid/upper Mississippi Valley...just a matter of exactly where and
when.
Temperatures for the valid period look to be slightly below normal...mainly
due to daytime highs being cooler than normal because of clouds and rain
chances.
Gosselin
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 613 PM CDT Sun Aug 3 2014
FG impacting SUS is possible once again late tonight. More
uncertainty exists for tonight as greater mixing occurred today.
Otherwise, ongoing SHRA near COU shud diminish with sunset.
Believe another area of TSRA will develop within an hour or two
across far wrn MO and ern KS, but these TSRA shud remain W of COU.
Isod to sct TSRA are expected Mon during the late morning and thru
the afternoon. Coverage is currently not expected to be great enuf
to mention in TAF attm.
Specifics for KSTL: VFR and dry thru the period with winds aob 8
kts expected. TSRA poss Mon afternoon.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
855 PM MDT Sun Aug 3 2014
.DISCUSSION...
Update forthcoming. Thunderstorm activity continues to decrease.
Currently, the strongest storms are moving across eastern Fergus and
southern Blaine counties and should clear the area by midnight.
Additionally, showers are moving through southern Beaverhead County
at this time. Radar returns indicate isolated activity occurring
across southern Alberta and RUC analysis develops some qpf along the
International Boundary and the Hi-Line overnight. So have kept low
POPs there as well as along the Rocky Mountain Front and over
portions of southwest Montana. Monday looks to be another replay of
today. Overnight temperatures look good.
&&
.AVIATION...
UPDATED 2320Z.
VFR conditions are mostly expected across the area through the
period, but brief IFR/MVFR conditions are possible with
thunderstorms. A weak disturbance moving across north central (KCTB
KHVR) and central (KGTF KLWT) Montana will bring isolated to
scattered weak thunderstorms to these areas through around 03Z. The
greatest concentration of storms is currently moving east between
KGTF and KCTB and will likely remain between KHVR and KLWT. These
storms will likely produce brief heavy rain, small hail, and gusty
winds. However, the main impact on terminals will likely remain
gusty winds, so have only included that in the TAFs. Moisture is
also currently moving north to around the southern MT/ID border,
bringing thunderstorms there, but these storms will likely not reach
KBZN or KHLN, so have left the mention of storms out of those areas
tonight. However, this moisture will advance north into southwest
and central Montana on Monday as an upper low moves north through
the Great Basin. This will bring an increased chance of storms as
far north as a KGTF-KLWT line after 20Z. A weak area of low pressure
will also slowly move east into far northwest Montana through the
period, bringing a chance of isolated storms to the KCTB terminal
area after 20Z.
Coulston
&&
.PREV DISCUSSION...Issued 246 PM MDT Sun Aug 3 2014
Tonight through Tuesday...Short term forecast period continues to
be dominated by an upper level ridge over the western USA. As a
result, very little change is expected in the day to day forecast.
Very warm temperatures are expected each afternoon with winds
remaining generally light. Afternoon and evening thunderstorms are
expected each day...with isolated to scattered convection continuing
through the overnight and morning hours. Southwest Montana should
see the bulk of convection each day with numerous thunderstorms
expected Monday and Tuesday evening. Locally heavy rain, small
hail, gusty winds and occasional lightning strikes are expected to be
the main threats with any storms that develop. mpj
Tuesday Night through Sunday...A repeat of the current pattern
continues through the long term. Warm temperatures and isolated to
scattered thunderstorms will develop each afternoon, generally
starting up over terrain. With the showery nature of monsoonal
moisture, uncertainty remains with precipitation amounts and
coverage. Areas near higher terrain have the best chance of seeing
precipitation, namely the Continental Divide and Southwest
Montana. Latest model runs suggest a stronger push of moisture in
the Tue/Wed into Thu time frame. GFS brings in moisture over
Southwest Montana by Tue whereas the ECM holds it off until Wed.
There are also differences with placement as the ECM keeps
moisture a little more confined to the southwest. Did not jump on
either direction and went more in the middle of the two models.
Flow may become more westerly by the end of next week as high
pressure retreats southward a little bit. Not much in the way of
weather is expected though.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 58 86 59 84 / 10 20 40 30
CTB 53 83 54 82 / 20 20 30 30
HLN 58 87 59 86 / 10 30 40 40
BZN 55 85 56 83 / 10 40 40 50
WEY 50 73 48 70 / 10 50 50 60
DLN 55 80 54 80 / 20 40 40 50
HVR 58 88 61 86 / 20 10 30 30
LWT 57 85 59 80 / 20 20 40 40
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
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AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
619 PM CDT SUN AUG 3 2014
.SYNOPSIS...
ISSUED AT 345 PM CDT SUN AUG 3 2014
AT 19Z WATER VAPOR IMAGERY SHOWS THE CONTINUED WESTERN RIDGE/EASTERN
TROUGH PATTERN ONGOING. HOWEVER THERE IS A POTENT UPPER LEVEL LOW
MOVING INTO SOUTHERN CALIFORNIA ON THE WESTERN SIDE OF THE RIDGE.
ACROSS CANADA...COULD SEE A FEW NOTABLE SHORTWAVE TROUGHS...THE
FIRST OVER NORTHERN SASKATCHEWAN AND THE SECOND OVER SOUTHERN
BRITISH COLUMBIA. OTHER WEAK DISTURBANCES COULD ALSO BE SEEN
ROUNDING THE RIDGE AND MOVING THROUGH NORTHWEST FLOW INTO THE
CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOCALLY...A WEAK
SURFACE BOUNDARY WAS SEEN FROM NORTHWEST NEBRASKA ARCING DOWN INTO
SOUTH CENTRAL NEBRASKA...ROUGHLY FROM KCDR TO KLBF TO KGRI.
TEMPERATURES HAD REACHED THE UPPER 80S AND LOW 90S MOST
PLACES...WHICH WERE AT OR NEAR FULL MIXING POTENTIAL. STARTING TO
SEE SOME CUMULUS POP UP ACROSS THE AREA...WHILE AREAL COVERAGE IS
LOW DUE TO A LACK OF MID LEVEL MOISTURE.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN AUG 3 2014
ANY SHOWERS OR STORMS THAT DEVELOP ACROSS THE FORECAST AREA THIS
AFTERNOON DUE TO THE FAVORABLE LOW AND MID LEVEL CONDITIONS FOR GOOD
SB INSTABILITY WITH THE STEEP LOW AND MID LEVEL LAPSE RATES SHOULD
BE FAIRLY SHORT LIVED AND EXPECT ANY ACTIVITY TO END EARLY THIS
EVENING WITH THE LOSS OF DAYTIME HEATING AND STABILIZATION OF THE
BOUNDARY LAYER AS THERE WILL NOT BE SUPPORT ALOFT TO SUSTAIN ANY OF
THIS ACTIVITY.
ALTHOUGH IT IS DIFFICULT TO PICK OUT IN WATER VAPOR IMAGERY...MODELS
INDICATE A WEAK SHORTWAVE TROUGH OVER SOUTHERN MONTANA
CURRENTLY...WITH ANOTHER WEAK DISTURBANCE OVER WESTERN SOUTH DAKOTA.
THE SD SHORTWAVE MAY BRING ENOUGH LIFT TO BRING SOME SCATTERED
SHOWERS AND THUNDERSTORMS INTO NORTHWEST NEBRASKA THIS EVENING.
CONFIDENCE IS NOT HIGH IN THIS OCCURRING AS MOISTURE IS FAIRLY
LIMITED...BUT THE HRRR AND RAP HAVE BEEN CONSISTENTLY SIGNALING SOME
STRONGER CONVERGENCE AND LIFT IN THIS AREA SO WILL INCLUDE A SLIGHT
CHANCE IN THIS EVENING OVER THE NORTHWEST CORNER OF THE FORECAST
AREA. THEN OVERNIGHT...THE SHORTWAVE TROUGH OVER MONTANA WILL MAKE
ITS WAY INTO NORTH CENTRAL NEBRASKA. AS HAS BEEN OCCURRING FOR
SEVERAL DAYS...TEMPERATURES ARE COOL ENOUGH IN THE MID LEVELS TO
KEEP LAPSE RATES VERY STEEP AND EVEN SLIGHT LIFT FROM WEAK
SHORTWAVES SEEMS TO BE ENOUGH TO ALLOW STORMS TO DEVELOP
NOCTURNALLY. ALTHOUGH THERE IS QUESTION TO IF THERE WILL BE ENOUGH
MOISTURE TO WORK WITH...AND EXACTLY WHERE THE CHANCES WILL BE BEST
THE CURRENT THOUGHTS ARE THAT ACTIVITY WILL PASS ACROSS THE
NORTHEAST PART OF THE FORECAST AREA...ROUGHLY EAST OF A VALENTINE TO
TAYLOR LINE. THIS ENDS EARLY MONDAY MORNING.
THE UPPER LEVEL PATTERN DOES BEGIN TO SEE A SHIFT THROUGH THE DAY
MONDAY. THE UPPER LOW OVER CALIFORNIA WILL MOVE INTO THE RIDGE WHICH
WILL CAUSE THE RIDGE TO START SHIFTING EAST. MEANWHILE...THE
SHORTWAVE OVER SASKATCHEWAN WILL DIVE INTO THE GREAT LAKES REGION TO
PUSH A COLD FRONT THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND
APPROACH NORTHEAST NEBRASKA BY THE END OF THE DAY. ALSO...THE
BRITISH COLUMBIA SHORTWAVE WILL START SLOW EASTERLY MOVEMENT WHICH
WILL PLAY THE PART OF FLATTENING THE RIDGE. THIS MOVEMENT IN THE
UPPER LEVELS WILL LEAD TO LOW PRESSURE DEVELOPING OVER THE LEE SIDE
OF THE ROCKIES TONIGHT AND MONDAY...WITH WINDS IN TURN SWITCHING
AROUND TO THE SOUTH BY MONDAY MORNING. EXPECTING THE WINDS TO
INCREASE THROUGH THE DAY AS THE PRESSURE GRADIENT TIGHTENS. AS THE
RIDGE SHIFTS EAST...TEMPERATURES ALOFT WILL WARM ON MONDAY. CURRENT
700MB TEMPERATURES IN THE UPPER SINGLE DIGITS LOOK TO INCREASE TO
11-13C BY 00Z TUESDAY SO SHOULD HAVE THE POTENTIAL FOR A SLIGHTLY
WARMER DAY FOR MOST LOCATIONS FOR MONDAY WITH FORECAST HIGHS FROM
AROUND 90 TO THE MID 90S NORTHEAST TO SOUTHWEST.
MAINTAINED THE SLIGHT CHANCES FOR SHOWERS AND STORMS ACROSS THE
NORTH AND WEST MONDAY AFTERNOON. A SHORTWAVE MOVES TOWARDS NEBRASKA
IN THE AFTERNOON OUT OF WYOMING AND COLORADO...HOWEVER THE TIMING
LOOKS BETTER WITH THIS INTO THE EVENING. THE MODELS DO CONTINUE TO
DEVELOP PRECIPITATION OVER NORTHERN NEBRASKA IN THE AFTERNOON AS
MOISTURE POOLS ALONG A BOUNDARY IN THE VICINITY OF THE NE/SD BORDER.
DEWPOINTS RISE INTO THE UPPER 50S AND 60S AT THE SURFACE AND MID
LEVEL MOISTURE INCREASES...AND WITH LOW LEVEL LAPSE RATES STAYING
STEEP...PRECIPITATION CONTINUES TO LOOK POSSIBLE. INSTABILITY ISN/T
GREAT...WITH MU VALUES BEING UP TO 1000 J/KG...BUT DEEP LAYER SHEAR
WILL BE INCREASING SO COULD GET A FEW CELLS TO ORGANIZE IN THESE
AREAS TO GET A FEW STRONGER STORMS. WIDESPREAD SEVERE WEATHER IS NOT
ANTICIPATED.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN AUG 3 2014
A PATTERN SHIFT WILL LEAD TO A SURFACE LOW AND ASSOCIATED FRONTAL
SYSTEM MOVING SOUTHEAST MONDAY THROUGH WEDNESDAY NIGHT. A HIGHER
CHANCE FOR THUNDERSTORMS OCCURS TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE EAST. THE PRECIPITABLE WATER RATIOS WILL BE
HIGHER WHERE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS THAT MAY
FORM. AS THE FRONT MOVES EAST AND SOUTH THURSDAY THE TRAILING END
OF THE FRONT BACKS WEST AND NORTHWEST THROUGH THE WESTERN
PANHANDLE. IF THE FRONT STALLS ACROSS NORTHERN KANSAS AS SHOWN...A
PREVAILING EASTERLY SURFACE FLOW WOULD INCREASE THE MOISTURE
SUPPLY FOR INCREASED CLOUDS INTO THE EXTENDED PERIOD. A CHANCE OF
THUNDERSTORMS DAILY LINGERS AS THE STALLED BOUNDARY TO THE SOUTH
WOULD KEEP TEMPERATURES CLOSER TO NORMAL...OR BELOW NORMAL
...GOING FORWARD WITH DAYTIME HIGHS IN THE 80S OVER THE
SOUTHWEST...AND 70S IN THE NORTH AND NORTH CENTRAL. MODEL
CONSENSUS DIVERGES BEYOND WEDNESDAY NIGHT WITH A SUPERBLEND OF THE
SOLUTIONS USED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 614 PM CDT SUN AUG 3 2014
SHORT RANGE PROJECTION SHOWS THUNDERSTORMS IN WESTERN NEBRASKA
ORGANIZING AND CROSSING NORTH CENTRAL AND NORTHWEST NEBRASKA.
THOUGH THERE IS CONSIDERABLE UNCERTAINTY REGARDING THE EVOLUTION
OF THE SYSTEM...INDICATIONS ARE THAT THEY WILL PROBABLY AFFECT VTN
BETWEEN 05Z AND 08Z BUT THEY WILL PROBABLY STAY NORTH OF BBW-LBF-
OGA. AFTER 09Z...STORMS ARE NOT EXPECTED. THERE IS A POSSIBILITY
OF THUNDERSTORMS DEVELOPING IN WESTERN NEBRASKA MONDAY AFTERNOON.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SUN AUG 3 2014
ON THE NORTH PLATTE RIVER...FROM LAKE MCCONAUGHY DOWNSTREAM TO
BRADY...IRRIGATION RELEASES CONTINUE TO SLOWLY CREEP UP THE FLOWS WITH
THE CURRENT STAGE AT THE NORTH PLATTE GAGE AT 5.4 FEET. THE RIVER
FORECAST FOR THE NORTH PLATTE GAGE...NEAR THE HIGHWAY 83 BRIDGE...IS
FOR FLOWS TO REMAIN AROUND 5.5 FEET THROUGH THURSDAY. THERE IS A
CHANCE FOR THUNDERSTORMS DAILY WHERE SOME FLUCTUATIONS ARE
POSSIBLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...KECK
AVIATION...SPRINGER
HYDROLOGY...KECK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
320 PM CDT SAT AUG 2 2014
.SYNOPSIS...
ISSUED AT 320 PM CDT SAT AUG 2 2014
THE WESTERN CONUS RIDGE/EASTERN CONUS TROUGH PATTERN CONTINUES IN
THE UPPER LEVELS WITH THE CENTRAL PLAINS UNDER THE INFLUENCE OF
NORTHWEST FLOW WITH WEAK SHORTWAVES PERIODICALLY MOVING OVER THE
RIDGE AND ACROSS THE AREA AS THEY DIVE INTO THE TROUGH. AT
19Z...NOTING A SHORTWAVE TROUGH MOVING INTO NORTHERN SOUTH
DAKOTA...WITH ANOTHER OVER SOUTHERN WYOMING. 02.12Z SOUNDINGS SHOWED
700MB TEMPERATURES OF 9C AND 8C AT KUNR AND KLBF RESPECTIVELY...WITH
5C AND 6C AT KABR AND KOAX. THIS WOULD INDICATE THAT ALTHOUGH THE
AREA IS UNDER NORTHWEST FLOW...THE WARM AIR ALOFT UNDER THE RIDGE
CONTINUES TO STAY IN PLACE ACROSS THE WESTERN PLAINS. HOWEVER...THIS
AIR IS NOT WARM ENOUGH TO CAP THE BOUNDARY LAYER. AT THE
SURFACE...LOW PRESSURE WAS SITUATED OVER SOUTH CENTRAL SOUTH
DAKOTA...JUST NORTH AND EAST OF KVTN WITH A WEAK TROUGH OF LOW
PRESSURE EXTENDING SOUTH THEN WEST /TO AROUND KBBW THROUGH KLBF AND
KOGA. STRONG HEATING AT THE SURFACE WITH HIGHS IN THE UPPER 80S AND
LOW 90S HAS CREATED DEEP MIXING UP TO 600MB AND WITH STEEP LAPSE
RATES CONVECTION HAS BEGUN TO DEVELOP ACROSS THE AREA WHERE
CONVERGENT BOUNDARIES EXIST. MU CAPES ARE 1500 TO 2000 J/KG BUT
THERE IS VERY LITTLE SHEAR OVER ONGOING CONVECTION SO ACTIVITY HAS
BEEN VERY UNORGANIZED THUS FAR THIS AFTERNOON.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 320 PM CDT SAT AUG 2 2014
SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THE AFTERNOON AND
INTO THIS EVENING UNTIL LOSS OF DAYTIME HEATING STABILIZES THE
BOUNDARY LAYER AND CUTS OFF THE ENERGY INTO THE STORMS. THE SURFACE
LOW OVER SOUTH DAKOTA WILL SLOWLY MOVE SOUTHEAST THROUGH THE EVENING
WITH THE PRECIPITATION GENERALLY STAYING ALONG AND SOUTH OF AN ARC
FROM THE LOW TO KTIF TO KAIA. PRECIPITATION CHANCES WILL SLIDE SOUTH
AND EAST THROUGH THE EVENING...AND SHOULD GENERALLY BE DONE BY 06Z.
THE RAP AND THE NAM DO INDICATE AN INCREASE IN DEEP LAYER SHEAR AS A
SHORTWAVE TROUGH OVER THE DAKOTAS SLIDES SOUTHEAST THIS EVENING. IS
NOT OUT OF THE QUESTION TO GET AN ISOLATED STORM THAT IS ABLE TO GET
ORGANIZED AND PRODUCE HAIL OR STRONG WINDS...BUT FEEL IT WILL BE
SHORT LIVED AND NO REAL THREAT FOR SEVERE STORMS IS CURRENTLY A
CONCERN.
AS THE SHORTWAVE OVER SOUTH DAKOTA MOVES SOUTHEAST INTO NORTHERN
NEBRASKA LATER THIS EVENING AND OVERNIGHT THERE ARE INDICATIONS OF
WARM AIR ADVECTION AND STRONGER LIFT AHEAD OF IT...ALONG WITH
MOISTURE TRANSPORT IN THE 850MB TO 700MB LAYER. ALTHOUGH NONE OF
THIS IS REAL STRONG COULD GET MORE CONVECTION TONIGHT. IF IT DOES
DEVELOP...ONE QUESTION WILL BE HOW FAR WEST IT WILL BE. CURRENT
SUITE OF MODELS SHOW MOST OF THIS ACTIVITY WILL JUST SKIRT THE LOCAL
FORECAST AREA...MAINLY KEEPS IT OVER NORTHEAST NEBRASKA.
THEN FOR SUNDAY...NOT MUCH CHANGE IN THE GENERAL WEATHER PATTERN.
TEMPERATURES ALOFT WARM SLIGHTLY BUT NOT MUCH SO STILL LOOKING FOR
HIGHS NEAR 90 OR IN THE LOW 90S MOST LOCATIONS. WITH THE EXCEPTION
OF THE GFS...MODELS ARE ALL DEVELOPING CONVECTION IN THE AFTERNOON
ALONG A WEAK SURFACE FRONT FROM NORTHWEST TO SOUTH CENTRAL NEBRASKA.
STRONG DAYTIME HEATING WILL AGAIN DESTABILIZE THE LOW LEVELS OF THE
TROPOSPHERE AND WILL CREATE STEEP LAPSE RATES WITH MIXING TO NEAR
650MB. ALSO...THERE IS A WEAK SHORTWAVE PROJECTED TO MOVE INTO
NORTHWEST NEBRASKA NEAR MID AFTERNOON TO ENHANCE THE LIFT IN THE
AREA. AS SIMILAR CONDITIONS OVER THE PAST SEVERAL DAYS HAVE CAUSED
DEVELOPMENT OF ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM
ACTIVITY SEE NO REASON WHY IT WON/T OCCUR AGAIN SUNDAY AFTERNOON AND
HAVE ADDED CHANCES FOR PRECIPITATION INTO THE FORECAST.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 320 PM CDT SAT AUG 2 2014
SUNDAY NIGHT...WRN STATES UPPER RIDGE AXIS BUILDS EWD AS UPPER LOW
OVER SERN CANADA ALSO SHIFTS EWD. SURFACE HIGH PRESSURE BEGINS TO
SLIDE SWD INTO THE GREAT LAKES AND UPPER MISSISSIPPI VALLEY WHICH
ALLOWS A WEAK BOUNDARY TO BACK WWD INTO THE NERN PORTION OF THE FCST
AREA SUNDAY NIGHT INTO MONDAY. AS THIS HAPPENS...LEE SIDE LOW
PRESSURE REDEVLOPS ACROSS THE NRN HIGH PLAINS SETTING UP A
BAROCLINIC ZONE ALONG THE PERIPHERY OF THE ERN SIDE OF THE UPPER
RIDGE AXIS...ACROSS THE DAKOTAS AND NRN NEBRASKA. THE ULITMATE
PLACEMENT OF THIS FRONTAL BOUNDARY WILL BE KEY TO THE PRECIPITATION
FCST THROUGH THE WEEK AND IS DISCUSSED FURTHER BELOW. MODELS ARE
SIMILAR WITH THIS PLACEMENT BY MONDAY THOUGH DIFFER BEYOND. THE NRN
PORTION OF THIS BOUNDARY BECOMES CO-LOCATED WITH AN AREA OF MID
LEVEL FRONTOGENESIS SUNDAY EVE WHICH WILL HELP TO GENERATE DEEP
LAYER LIFT AND A BETTER CHC OF THUNDERSTORMS NORTH OF NEB SUNDAY
EVE. HOWEVER...UPPER NW FLOW HAS GENERATED ISOLATED THUNDERSTORMS IN
THE CURRENT PATTERN DUE TO WEAK BOUNDARY INTERACTIONS AND STEEP
LAPSE RATES ALOFT...AND WOULD EXPECT A SIMILAR SCENARIO FOR SUNDAY
EVE FURTHER SOUTH INTO WESTERN AND NORTH CENTRAL NEB...AND THEREFORE
SLIGHT CHANCES FOR THUNDERSTORMS WILL BE IN THE FCST BEFORE MIDNIGHT
SUNDAY. MIN TEMPS SUNDAY NIGHT NEAR TO SLIGHTLY ABOVE AVERAGE FOR THIS
TIME OF YEAR.
MONDAY INTO TUESDAY THE SHIFT IN THE RIDGE AXIS ALONG THE FRONT
RANGE ALLOWS SUBSIDENCE AND DRYING TO OCCUR OVER THE HIGHER TERRAIN
FURTHER WEST. THIS IN TURN WILL ALLOW FOR A RETURN OF THE NOCTURNAL HIGH
PLAINS LLJ WHICH DEVELOPS IN RESPONSE TO THE MORE RAPID COOLING OF
THE HIGHER TERRAIN IN THE EVENING COMPARED TO A MORE MOIST
ATMOSPHERE FURTHER EAST. THIS LLJ ALSO STRENGTHENS IN RESPONSE TO
UPPER PV ANOMALIES ROUNDING THE NOW FLATTENED RIDGE WITH ASSOCIATED
SFC CYCLOGENESIS FAVORING THE WY/CO FRONT RANGE AND WRN HIGH PLAINS
BY MID WEEK. THIS ALL SETS THE STAGE FOR INCREASED THUNDERSTORM
DEVELOPMENT...ESPECIALLY DURING THE LATE EVENING AND OVERNIGHT
HOURS...MONDAY AND TUESDAY AND ON INTO THE REST OF THE WEEK. THE
PREVIOUSLY MENTIONED FRONTAL BOUNDARY CONTINUES TO SAG FURTHER SWD
AND EVENTUALLY ACROSS THE WESTERN AND NORTH CENTRAL PORTION OF
NEBRASKA DURING MID WEEK. THE LLJ WILL BE EFFICIENT AT SUPPLYING LOW
LEVEL MOISTURE TO THE ATMOSPHERE WHICH WILL BE FURTHER ENHANCED BY
TROPICAL MOISTURE MOVING NWD THROUGH THE GREAT BASIN AREA AROUND THE
AFOREMENTIONED UPPER HIGH. THE RESULT IS PW VALUES APPROACHING +2
STANDARD DEVIATIONS ABOVE THE MEAN FOR THIS TIME OF YEAR...NEARING
1.75 INCHES BY THU. IN ADDITION...MODEST INSTABILITY DEVELOPS E OF
THE STATIONARY/WARM FRONTAL BOUNDARY IN ERN NEB EARLY IN THE WEEK
BUT SHIFTS SWWD BY WED/THU TIME FRAME AS DOES THE BOUNDARY. THE
SPECIFIC DETAILS OF BOUNDARY LOCATION FROM DAY TO DAY WILL BE
DETERMINED LARGELY BY EACH ITERATION OF CONVECTIVE DEVELOPMENT AS
MESOSCALE COLD POOL AUGMENTATION OF THE BOUNDARY TAKES
PLACE...MAKING SPECIFIC DETAILS OF THUNDERSTORM DEVELOPMENT
DIFFICULT. IN GENERAL...THE DEVELOPING LARGE SCALE PATTERN BY MID
WEEK SUPPORTS AN INCREASED CONFIDENCE IN INCREASING THUNDERSTORM
CHANCES THROUGH THE WEEK. DAYTIME MAX TEMPERATURES WILL BE AVERAGE
TO SLIGHTLY ABOVE TO START THE WEEK...BUT WILL LOWER TO BELOW
AVERAGE BY THE END OF THE WEEK. THE DIURNAL RANGE OF TEMPS AS THE
WEEK PROGRESSES HOWEVER LESSENS WITH LOWS REMAINING NEAR OR ABOVE
AVERAGE THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1245 PM CDT SAT AUG 2 2014
SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY
EVENING FOR MUCH OF WESTERN INTO NORTH CENTRAL NEBRASKA. HOWEVER
LOCATIONS NORTH OF A LINE FROM KIEN TO KONL ARE LESS LIKELY TO SEE
CONVECTION. EXPECT THE CONVECTION TO BE ISOLATED TO SCATTERED IN
NATURE SO DON/T HAVE HIGH CONFIDENCE IN ANY PARTICULAR LOCATION
OBSERVING A THUNDERSTORM. THE MOST LIKELY TIME FRAME IS 21Z TO
01Z. THIS ACTIVITY WILL DIMINISH THIS EVENING...BUT THERE IS
POTENTIAL FOR SOME SHOWERS AND STORMS TO COME OUT OF CENTRAL SOUTH
DAKOTA AND HIT NORTH CENTRAL INTO NORTHEAST NEBRASKA AFTER
MIDNIGHT. LOCALLY...THIS COULD IMPACT KONL. OTHERWISE...LIGHT
WINDS AND VFR CONDITIONS ARE EXPECTED.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...JWS
AVIATION...BROOKS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1229 PM CDT SAT AUG 2 2014
.UPDATE...
ISSUED AT 1228 PM CDT SAT AUG 2 2014
THE FORECAST FOR THIS AFTERNOON HAS REALLY NOT CHANGED MUCH FROM
WHAT WAS INHERITED FROM THE NIGHT SHIFT. THE MILLION DOLLAR
QUESTION IS HOW MUCH...IF HARDLY ANY OF THE CWA REALIZES RENEWED
DEVELOPMENT OF SHOWERS/STORMS BEFORE 00Z/7PM. ALTHOUGH FORCING
FEATURES ARE FAIRLY SUBTLE...THERE APPEAR TO BE TWO LOW AMPLITUDE
SHORTWAVE TROUGHS/RIPPLES WORKING THROUGH THE NORTHWEST FLOW
ALOFT...ONE SHIFTING THROUGH SOUTHEAST NEB/NORTHEAST KS...AND THE
OTHER POTENTIALLY OF GREATER CONSEQUENCE DROPPING SOUTH- SOUTHEAST
OUT OF SD INTO GENERALLY THE EASTERN HALF OF NEB. THE FORMER WAVE
IS CURRENTLY AIDING SOME SHOWER/WEAK STORM ACTIVITY IN EASTERN
NEB...BUT THIS APPEARS TO BE SAFELY EAST OF THE CWA UNLESS
SOMETHING NEW WOULD HAPPEN TO FLARE UP IN OUR EXTREME SOUTHEAST
COUNTIES WITHIN THE NEXT FEW HOURS. OTHERWISE...HAVE OFFICIALLY
CONFINED ANY SLIGHT CHANCES OF CONVECTION THROUGH 00Z TO ROUGHLY
AREAS WEST OF A BEAVER CITY-ORD LINE...WHERE VARIOUS MODELS SEEM
TO HINT AT HAVING THE BEST COMBINATION OF STEEPER MID LEVEL LAPSE
RATES AND SUBTLE SURFACE CONVERGENCE. GIVEN THE EXPECTED
COMBINATION OF MIXED-LAYER CAPE VALUES POTENTIALLY 1000+ J/KG
ALONG WITH DEEP LAYER SHEAR OF 25+ KT...ITS NOT OUT OF THE
QUESTION THAT IF ANY STORMS DO FORM WITHIN THE CWA THIS AFTERNOON
THEY COULD BE ON THE STRONG TO MARGINALLY SEVERE SIDE.
UNFORTUNATELY...CONFIDENCE IS NOT OVERLY HIGH IN HOW THESE NEXT
6-12 HOURS UNFOLD...LET ALONE BEYOND THAT...GIVEN THAT VARIOUS
SHORT TERM MODELS SUCH AS THE 12Z NAM AND THE 15Z HRRR APPEAR TO
BE OVER-ZEALOUS IN DEVELOPING CONVECTION THROUGH LATE AFTERNOON.
AGAIN...ALTHOUGH THE FAR WESTERN CWA APPEARS TO HOLD THE BEST
CHANCE OF POPPING ANY STORMS THROUGH 00Z/7PM...OTHER AREAS ARE NOT
GUARANTEED CONVECTION-FREE EITHER AND THUS HAVE MAINTAINED SILENT
5-10 PERCENT POPS CWA-WIDE FOR LATER THIS AFTERNOON.
TEMP-WISE THIS AFTERNOON...MADE VERY LITTLE IF ANY CHANGE TO
PREVIOUS HIGHS...AS THE MAJORITY OF THE CWA IS ON TRACK TO TOP OUT
SOMEWHERE IN THE 87-92 RANGE. NO FORECAST UPDATES HAVE BEEN
ISSUED YET FOR BEYOND 00Z/7PM THIS EVENING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CDT SAT AUG 2 2014
THE SHORT TERM ISSUE IS THE CONTINUATION OF MORNING SHOWERS
AND ISOLATED THUNDERSTORMS IN THE NORTHERN FORECAST AREA. THE
PREVIOUS FORECASTS HAD THIS AREA HANDLED WELL WITH COVERAGE
AND TIMING OF ONGOING SHOWERS NORTH OF NEBRASKA STATE HIGHWAY
92. SHORT TERM MODELS HAVE GOOD HANDLE ON THIS TREND...AND
THE IDEA THEY WILL WORK SOUTH TOWARD I-80 AND FIZZLE IN THE
MID MORNING HOURS. NOT UNCOMMON FOR EARLY AUGUST. RAIN
AMOUNTS WILL BE LIGHT...FEW HUNDREDTHS...BUT SOME THUNDER
IS STILL AROUND AND CAN/T BE COUNTED OUT. THE SOUTHERN 2/3RDS
OF THE FORECAST SHOULD BE DRY THIS MORNING.
THE ACTIVITY THIS MORNING APPEARS TO BE AT LEAST IN PART
ASSOCIATED WITH A WAVE MOVING SOUTH FROM THE DAKOTAS. AT THIS
POINT...NOT SURE WHY THERE WOULDN/T BE DEVELOPMENT THE MODELS ARE
HINTING AT TOWARD EVENING AS THE WAVE DIPS SOUTH. LOCATION IS
CHALLENGING...BUT BELIEVE THE FOCUS WILL AGAIN BE ON THE WEST
PORTION OF THE FORECAST AREA...EXTENDING FURTHER EAST/NORTH
OVERNIGHT. ITS SEEMS IT COULD BE ON THE SOUTHWEST FLANK OF
WHATEVER IS LEFT OVER FROM THIS MORNINGS CONVECTION. KANSAS
COUNTIES PROBABLY THE ODD MAN OUT REGARDING RAIN...BUT FORECASTING
THE EXACT LOCATION OF ANY STORM LATER TODAY IS FAR FROM SETTLED
SCIENCE EVEN A MERE 12-15 HOURS OUT. HAVE INCLUDED A 15-30 PERCENT
CHANCE OF PRECIPITATION FOR THESE AREAS CENTERED ON THIS EVENING
AND EARLY OVERNIGHT. SEVERE WEATHER IS GENERALLY NOT EXPECTED.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 311 AM CDT SAT AUG 2 2014
NO MAJOR CHANGES TO THE LONG TERM FORECAST. SUNDAY COULD BE
ANOTHER DAY SIMILAR TO TODAY...BUT THE RIDGE STARTS TO BUILD
A BIT INTO CENTRAL PLAINS INTO MONDAY. THIS SHOULD TEMPORARILY
SQUELCH MOST CONVECTION...ALTHOUGH CAN/T SAY FOR SURE THERE IS
NO CHANCE. PROBLEM...JUST CAN/T REALLY SAY THERE IS A CHANCE
WITH ANY DEFINITIVE LOCATION BEYOND ABOUT 24 HOURS. WILL LEAVE
BOTH DAYS DRY FOR NOW...BUT THERE MAY BE SOME LINGERING SPRINKLES
EARLY SUNDAY MORNING IN SOME AREAS.
THE UPPER LEVEL RIDGE FLATTENS BEGINNING TUESDAY. THIS ALLOWS FOR
A MORE ACTIVE PATTERN AS A FRONTAL BOUNDARY SETTLES AND SLIPS
ACROSS THE FORECAST AREA AROUND WEDNESDAY. NO REASON TO DEVIATE
FROM 20-30-40 PERCENT RAIN CHANCES THAT PERIOD...PROBABLY FAVORING
THE WEDNESDAY/THURSDAY TIME FRAME. THOUGH RAIN CHANCES ARE
WIDESPREAD...IT WON/T NECESSARILY RAIN A WHOLE LOT EVERYWHERE...BUT
THERE IS LITTLE TO REASON TO DOUBT AT THIS POINT THE END OF THE
END OF NEXT WEEK/INTO NEXT WEEKEND HAS THE POTENTIAL TO BRING SOME
NEEDED RAIN TO THE REGION. TEMPERATURES WILL BE SEASONAL TO
SLIGHTLY BELOW NORMAL DEPENDING UPON HOW WIDESPREAD CLOUDS AND
PRECIPITATION BECOME LATER IN THE WEEK.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z SUNDAY)
ISSUED AT 1226 PM CDT SAT AUG 2 2014
CONFIDENCE REMAINS RATHER HIGH IN VFR CEILING/VISIBILITY
THROUGHOUT THE PERIOD...WITH ONLY LIMITED COVERAGE OF PASSING MID
LEVEL CLOUDS. ALTHOUGH A BRIEF SHOWER/THUNDERSTORM CANNOT BE RULED
OUT ESPECIALLY FROM LATE THIS AFTERNOON INTO THIS
EVENING...CONFIDENCE IN PROBABILITY OF OCCURRENCE/AREAL COVERAGE
DOES NOT EVEN APPEAR TO WARRANT A VICINITY THUNDERSTORM (VCTS)
MENTION AT THIS POINT. SUSTAINED SURFACE BREEZES ARE FORECAST TO
GENERALLY AVERAGE NO MORE THAN 8-11KT THROUGH THE PERIOD...AS
DIRECTION GRADUALLY SHIFTS FROM MORE SOUTHERLY THIS AFTERNOON TO
MORE SOUTHWESTERLY DURING THE LATTER HALF OF THE PERIOD. THE
DEVELOPMENT OF A SOUTHWESTERLY LOW LEVEL JET OVERNIGHT COULD
RESULT IN UP TO AROUND 30KT OF BULK SHEAR DIFFERENCE BETWEEN THE
SURFACE WIND AND WIND ALOFT UP INTO THE 1-2 THOUSAND FEET AGL
LEVEL...WHICH COULD RESULT IN AT LEAST SOME MARGINAL LOW LEVEL
WIND SHEAR (LLWS). GIVEN THAT THIS POSSIBILITY IS LARGELY BEYOND
THE FIRST 12 HOURS OF THE TAF PERIOD...AND THAT THIS 30KT SHEAR
MAGNITUDE IS ONLY MARGINAL FOR FORMAL TAF INCLUSION ANYWAY...WILL
HOLD OFF ON ANY LLWS MENTION FOR NOW AND DEFER TO LATER FORECASTS
TO RE-EXAMINE.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...NOAA/NWS/MORITZ
LONG TERM...NOAA/NWS/MORITZ
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
300 PM MDT SAT AUG 2 2014
.SYNOPSIS...
ABUNDANT MOISTURE WILL LINGER OVER NEW MEXICO THROUGH EARLY NEXT
WEEK...AND SLOW MOVING STORMS WILL CONTINUE TO BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAIN...WHICH COULD LEAD TO FLASH FLOODING.
AREAS ALONG AND WEST OF THE CONTINENTAL DIVIDE WILL BE THE FOCUS FOR
THE HEAVIER STORMS TONIGHT AND INTO SUNDAY...WHILE THE FOCUS SLOWLY
SHIFTS TO THE NORTHWEST THIRD TO HALF SUNDAY NIGHT...AND PORTIONS OF
THE WEST AND CENTRAL MONDAY. HIGH TEMPERATURES WILL REMAIN BELOW
AVERAGE THROUGH MONDAY. A WARMING AND DRYING TREND IS EXPECTED BY
THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...
ABUNDANT CLOUD COVER LINGERING THIS AFTERNOON...AND LAPS SHOWING THE
EAST REMAINING STABLE SO FAR. CELLS HAVE BEEN FIRING ALONG/WEST OF
THE CENTRAL MT CHAIN AND MOST NOTABLY OVER WESTERN SOCORRO COUNTY TO
THE GALLUP AREA...BUT LESS ACTIVE OVERALL COMPARED TO THIS TIME THE
LAST COUPLE OF DAYS. PWATS FROM AREA 12Z SOUNDINGS SHOWED LITTLE
CHANGE FROM FRIDAY ALTHOUGH MID LEVEL WINDS ARE TRANSITIONING AS THE
WEAK UPPER LOW PREPARES TO MOVE NORTH INTO ARIZONA. INITIAL THOUGHTS
WERE THAT THE CURRENT FLASH FLOOD WATCH MAY HAVE NEEDED TO BE
EXPANDED NORTHWARD AND SOMEWHAT EASTWARD FOR TONIGHT...BUT 12Z LOCAL
WRF...NAM AND HRRR DON/T SUPPORT THAT IDEA AND ARE RATHER SPARSE
LOOKING IN AREAL COVERAGE. THEREFORE DECIDED TO LET THE CURRENT
WATCH RIDE...WHERE MOST OF THIS AFTERNOON/S ECHOS EXIST SO FAR.
SUNDAY/SUNDAY EVENING COULD BE QUITE ACTIVE ALONG AND WEST OF THE
CONTINENTAL DIVIDE AND CAN/T RULE OUT THE POTENTIAL FOR HEAVY RAIN
OVER THAT AREA...HOWEVER STORM MOTION LOOKS TO BE GENERALLY SOUTH TO
NORTH AT 10 TO 15 MPH. MODELS SUGGEST THE EAST WILL CONTINUE TO BE
FAIRLY QUIET. AS THE UPPER LOW MOVES INTO THE GREAT BASIN
MONDAY...THE THETA-E RIDGE AXIS SHIFTS MORE SOUTHWEST TO NE OVER NEW
MEXICO...PUTTING THE FOCUS FOR STORMS MORE INTO THE NORTHWEST AND
NORTH CENTRAL AND ALLOWING THEM TO DRIFT OFF THE MTS INTO THE
NORTHEAST AND CENTRAL HIGHLANDS. THE MID TO LATE WEEK PERIOD STILL
FEATURES A SUPPRESSION OF THE RIDGE...ALLOWING THE NORTHWEST TO DRY
OUT SOME...AND A DECREASE OVERALL IN CONVECTION. HIGH TEMPERATURES
SHOULD FINALLY EXPERIENCE A REBOUND TOWARDS NORMAL FOR THE FIRST
WEEK OF AUGUST.
&&
.FIRE WEATHER...
A WET AND ACTIVE MONSOON PATTERN WILL CONTINUE OVER THE NEXT FEW
DAYS...KEEPING CRITICAL FIRE WEATHER CONDITIONS FROM DEVELOPING.
FOOTPRINTS OF WETTING RAINFALL HAVE BEEN SCATTERED EACH DAY OVER THE
PAST WEEK...BUT MOST AREAS OUTSIDE OF THE EASTERN PLAINS HAVE SEEN
PRECIPITATION ON OCCASION. WINDS WILL REMAIN LIGHT FOR THE MOST
PART...ONLY GETTING SLIGHTLY BREEZY IN THE VICINITY OF CENTRAL
GAPS/CANYONS THIS EVENING...AND OF COURSE GUSTY WITH ANY BRIEF AND
LOCALIZED THUNDERSTORM OUTFLOWS. THE FOCUS FOR STORMS WILL BE IN
SOUTHWESTERN SECTIONS OF THE FORECAST AREA TODAY AND
TONIGHT...SHIFTING TO THE WESTERN THIRD OF THE STATE SUNDAY.
THE BEST PLUME OF MOISTURE ALOFT WILL THEN BEGIN TO GRADUALLY LAY
OVER OR TOPPLE TO MORE OF A SOUTHWEST-NORTHEAST ORIENTATION MONDAY
AND TUESDAY...WITH STORMS STRETCHING FROM THE SW MOUNTAINS TO THE
NORTHERN MOUNTAINS BOTH DAYS. STORMS WILL ALSO PERIODICALLY BE
FILLING IN BETWEEN THESE AREAS. SOME LEE SIDE SURFACE TROUGHING WILL
ALLOW MODERATE BREEZES TO DEVELOP IN THE NORTHEAST MONDAY AND
TUESDAY. OVERALL HUMIDITY TRENDS WILL NOT VARY MUCH THROUGH THE NEXT
FEW DAYS WITH GOOD TO EXCELLENT RECOVERIES IN MUCH OF THE FORECAST
AREA EACH NIGHT/MORNING...ESPECIALLY WITHIN AREAS THAT RECEIVE
WETTING RAIN. BELOW AVERAGE TEMPERATURES ARE ALSO EXPECTED TO
CONTINUE THROUGH TUESDAY...KEEPING DAYTIME HUMIDITY FAIRLY ELEVATED
THROUGH TUESDAY. SOME DAY-TO-DAY DRYING IS THEN EXPECTED WEDNESDAY
THROUGH THE END OF NEXT WEEK. THIS WILL ALLOW TEMPERATURES TO START
CLIMBING BACK TO NEAR AVERAGE FOR EARLY AUGUST.
52
&&
.AVIATION...
18Z TAF CYCLE
EXTENSIVE MID TO HIGH LEVEL CLOUDS REMAIN OVER A LARGE MAJORITY OF
NORTHERN AND CENTRAL NEW MEXICO LATE THIS MORNING...AND A FEW
LOCALIZED HIGHER TERRAIN PLACES ARE STILL OBSERVING SOME LOWER
CLOUDS WITH MVFR CEILINGS. CLOUDS WILL DECREASE INTO THE EARLY
AFTERNOON BEFORE THE CYCLE STARTS OVER AGAIN WITH NEW CUMULUS
BUBBLING OVER WESTERN HIGH TERRAIN. BEST POTENTIAL FOR SHOWER AND
STORM DEVELOPMENT IS ACROSS THE WESTERN MOUNTAINS OF NEW
MEXICO THROUGH THE EVENING...ESPECIALLY THE SOUTHWESTERN MOUNTAINS
SURROUNDING THE GILA WILDERNESS THIS AFTERNOON. STORMS WILL ALSO
BE FOUND OVER THE NORTHERN MOUNTAINS AND POTENTIALLY THE CENTRAL
MOUNTAINS AS WELL. HEFTY DOWNPOURS...DOWNBURST WINDS...AND SMALL
HAIL WILL BE POSSIBLE WITH ANY THUNDERSTORMS. STORMS WILL LIKELY
NOT FULLY WANE IN WESTERN NM UNTIL THE EARLY MORNING HOURS SUNDAY.
TAFS HAVE BEEN BUILT WITH TEMPO GROUPS WHERE HIGHEST PROBABILITY
AND TIME FRAME WAS THOUGHT TO BE...BUT THESE MAY BE AMENDED
THROUGHOUT THE AFTERNOON/EVENING.
52
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 62 84 62 84 / 40 40 60 50
DULCE........................... 51 73 51 78 / 60 50 70 50
CUBA............................ 53 72 53 76 / 50 50 70 70
GALLUP.......................... 55 76 55 80 / 60 60 70 50
EL MORRO........................ 51 70 51 73 / 80 70 70 60
GRANTS.......................... 53 74 53 77 / 60 60 60 50
QUEMADO......................... 54 74 53 75 / 80 70 60 50
GLENWOOD........................ 58 81 56 82 / 80 50 50 40
CHAMA........................... 46 67 46 73 / 70 60 70 60
LOS ALAMOS...................... 53 72 54 74 / 50 50 50 60
PECOS........................... 52 73 52 73 / 30 40 40 60
CERRO/QUESTA.................... 48 71 49 76 / 40 50 50 50
RED RIVER....................... 47 66 46 65 / 40 50 50 60
ANGEL FIRE...................... 50 67 47 72 / 40 50 50 60
TAOS............................ 51 74 51 75 / 40 40 50 40
MORA............................ 51 72 51 73 / 30 40 40 60
ESPANOLA........................ 54 81 56 81 / 40 30 40 40
SANTA FE........................ 55 78 56 75 / 40 40 50 50
SANTA FE AIRPORT................ 57 80 57 78 / 40 40 40 40
ALBUQUERQUE FOOTHILLS........... 59 78 60 81 / 50 40 40 40
ALBUQUERQUE HEIGHTS............. 63 81 63 83 / 50 30 40 30
ALBUQUERQUE VALLEY.............. 60 82 61 85 / 40 30 40 30
ALBUQUERQUE WEST MESA........... 60 81 62 85 / 40 30 40 30
LOS LUNAS....................... 61 82 61 84 / 50 30 40 30
RIO RANCHO...................... 62 81 63 86 / 50 30 40 40
SOCORRO......................... 64 84 64 87 / 60 30 40 30
SANDIA PARK/CEDAR CREST......... 55 76 56 82 / 40 40 40 40
TIJERAS......................... 57 77 57 80 / 50 50 50 40
MORIARTY/ESTANCIA............... 54 76 55 78 / 30 30 40 40
CLINES CORNERS.................. 56 77 56 78 / 20 30 20 40
GRAN QUIVIRA.................... 56 78 57 79 / 40 40 30 30
CARRIZOZO....................... 60 80 60 80 / 40 30 30 30
RUIDOSO......................... 54 72 54 75 / 40 30 20 30
CAPULIN......................... 51 77 54 77 / 10 10 10 50
RATON........................... 54 81 56 81 / 20 20 10 30
SPRINGER........................ 53 79 55 81 / 20 20 10 30
LAS VEGAS....................... 52 77 53 77 / 20 20 20 40
CLAYTON......................... 59 87 61 88 / 10 5 5 10
ROY............................. 59 84 59 80 / 10 10 10 30
CONCHAS......................... 64 86 65 89 / 10 10 10 20
SANTA ROSA...................... 62 86 63 85 / 10 10 10 20
TUCUMCARI....................... 62 90 64 91 / 5 5 5 10
CLOVIS.......................... 60 86 61 85 / 5 5 5 5
PORTALES........................ 61 88 63 86 / 5 5 5 5
FORT SUMNER..................... 64 87 65 87 / 10 10 5 10
ROSWELL......................... 66 88 66 90 / 20 10 5 10
PICACHO......................... 61 81 61 82 / 20 20 10 20
ELK............................. 57 77 57 75 / 40 30 20 20
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES...
NMZ505-506-508-509-520.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
703 PM EDT SUN AUG 3 2014
.SYNOPSIS...
A FRONT WILL REMAIN ALONG THE COAST OF NORTH CAROLINA TONIGHT
THROUGH TUESDAY. ANOTHER FRONT WILL MOVE INTO THE AREA THURSDAY AND
REMAIN ALONG THE COAST THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 655 PM SUNDAY...AS HAS BEEN THE CASE THE PAST FEW
NIGHTS...PRECIPITATION HAS DIMINISHED IN COVERAGE AND MOSTLY MOVED
OFFSHORE DURING THE EVENING HOURS AS SHORTWAVE ENERGY MOVES OFF
THE NORTHERN OUTER BANKS. SHOULD SEE A LULL OF SEVERAL HOURS IN
THE PRECIPITATION OVER THE CENTRAL AND WESTERN COUNTIES WITH
GENERALLY LIGHT RAIN CONTINUING OVER THE OUTER BANKS AND PAMLICO
SOUND REGION. THE LATEST 3KM HRRR HAS THE BEST HANDLE ON THE
CURRENT PRECIPITATION PATTERN AND HAVE UTILIZED IT FOR THE
OVERNIGHT FORECAST. THE HRRR ALONG WITH THE NAM/GFS SHOWS THAT
PRECIPITATION WILL ONCE AGAIN FILL IN TOWARD MORNING WITH POPS
BECOMING LIKELY ALONG THE SOUTHERN COAST AND OUTER BANKS AND WEST
TO NEAR HIGHWAY 17. DO NOT ANTICIPATE THAT THE PRECIPITATION WILL
BE QUITE AS HEAVY AS RECENT DAYS...BUT STILL GOOD COVERAGE AND
GIVEN THE HIGH STREAMFLOWS...PRUDENT TO CONTINUE FLOOD WATCH
THROUGH MONDAY AS PRECIPITABLE WATER VALUES CONTINUE TO HOVER NEAR
2 INCHES. DID LOWER MINIMUM TEMPS A COUPLE OF DEGREES BASED ON
CURRENT VALUES.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
AS OF 155 PM SUN...TROUGH CONTINUES ALONG THE NORTH CAROLINA COAST
ON MONDAY WITH LOW PRESSURE WAVE OFF THE GA COAST MOVING NORTH ALONG
THE BOUNDARY AND HIGH PRESSURE NOSING INTO WESTERN NORTH CAROLINA.
CONTINUED EAST AND SOUTHEAST FLOW WILL KEEP HIGH PRECIPITABLE
WATERS...APPROACHING TWO AND A QUARTER INCHES IN THE AFTERNOON. IN
THE UPPER LEVELS...LOW PRESSURE WILL DROP INTO THE TENNESSEE
AREA...INCREASING SOUTHWESTERLY UPPER LEVEL FLOW OVER THE EAST
COAST. TIMING OF IMPULSES AROUND THIS LOW IS DIFFICULT SO WILL NOT
TRY TO TIME PRECIPITATION. BUT THE PERIOD WILL BE WET. HIGH
TEMPERATURES WILL AGAIN BE IN THE UPPER 70S TO LOWER 80S MONDAY
AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AS OF 2 PM SUN...WILL FINALLY BE SLOWLY EVOLVING INTO A DRIER
WEATHER PATTERN THRU THE MIDDLE OF THE WEEK AS THE MOIST SSW
TROPICAL MOISTURE FEED GRADUALLY GETS SHUNTED OFFSHORE BY BROAD LONG
WAVE TROF MOVING THRU THE EASTERN STATES. THE NAM SOLUTION OF
MERGING OF THE THE TROPICAL WAVE OVER THE BAHAMAS WITH BERTHA SEEMS
UNLIKELY BUT NOT TOTALLY DISCOUNTING THE POSSIBILITY OF THIS WETTER
SOLUTION VIA CONTINUED TROPICAL FEED THRU TUESDAY. WILL GRADUALLY
TAPER OFF POPS THRU THE PERIOD WITH JUST SLIGHT CHANCE REMAINING
OVER INLAND AREAS TUESDAY NIGHT THEN OVER THE ENTIRE AREA ON
WEDNESDAY AS A DRIER WNW MID LEVEL FLOW DEVELOPS. WILL CONTINUE TO
UNDERCUT MOS TEMPERATURE GUIDANCE A BIT THRU MIDWEEK GIVEN POTENTIAL
CLOUD COVER AND SCT PRECIP BUT MAY REACH BACK TO NEAR 90 DEGS AGAIN
BY WEDNESDAY.
THE DRIER FORECAST PERIOD MAY BE SHORT LIVED AS A SHORT WAVE
APPROACHES FROM THE NW LATE THURSDAY PROPELLING A SFC FRONT THRU THE
AREA. MODEL CONCENSUS SUGGESTS THAT THIS SFC BNDRY STALLS JUST SOUTH
OF THE FORECAST AREA LATE IN THE WEEK WITH OVERRRUNNING TYPE PRECIP
POSSIBLY LINGERING INTO NEXT WEEKEND. HIGH TEMPS BEHIND THE FRONT
WILL AGAIN FALL BLO NORMAL.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 18Z MONDAY/...
AS OF 7 PM SUNDAY...CEILINGS HAVE BEEN QUITE VARIABLE FOR MUCH OF
THE DAY...BUT EXPECT A PERIODS OF MVFR/IFR CEILINGS AND VSBYS
TOWARD MORNING GIVEN LIGHT WINDS AND A VERY MOIST GROUND. BULK OF
PRECIPITATION LOOKS TO REMAIN EAST OF THE TAF SITES
OVERNIGHT...BUT MODEL TRENDS SHOW RAIN ARRIVING AT LEAST THE
KEWN/KOAJ SITES BY 10-12Z MONDAY AS MID-LEVEL ENERGY AGAIN MOVES
INTO THE REGION. WITH BETTER MIXING BY MID-MORNING...WILL AGAIN
INDICATE IMPROVEMENT OF VFR CONDITIONS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... AS OF 2 PM
SUN...PERIODIC SUB VFR CONDITIONS EXPECTED THRU AT LEAST TUESDAY
AS SCATTERED PRECIPITATION CONTINUES IN THE CONTINUED MOIST
TROPICAL FEED. AIRMASS GRADUALLY DRIES OUT DURING MIDWEEK WITH
PREDOMINATE VFR RETURNING BY WED AND INTO THU. A COLD FRONT PUSHES
SOUTH THRU THE AREA LATER THU WITH ANOTHER CHANCE FOR SHOWERS AND
THUNDERSTORMS AND SUB-VFR FLYING CONDITIONS.
&&
.MARINE...
SHORT TERM /TONIGHT AND MONDAY/...
AS OF 7 PM SUNDAY...FRONTAL BOUNDARY REMAINS DRAPED ALONG THE
COAST AND LIGHT TO MODERATE SOUTHEAST/SOUTH WINDS SHOULD CONTINUE
TONIGHT INTO MONDAY AT GENERALLY 10 TO 15 KNOTS OR LESS. LOW
PRESSURE WILL MOVE NORTH ALONG THE FRONT UP THE COAST THROUGH THE
NIGHT. GRADIENT WILL CONTINUE TO TIGHTEN THROUGH THE DAY ON
MONDAY AS THE WAVE MOVES CLOSER TO THE NORTH CAROLINA WATERS. MAY
START TO FEEL THE EFFECTS OF BERTHA LATE MONDAY AFTERNOON WITH
INCREASING SWELL IN THE OUTER SOUTHERN WATERS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 2 PM SUN...SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED AS
SWELL ASSOCD WITH BERTHA WILL BEGIN TO ARRIVE IN EARNEST MONDAY
NIGHT WITH BOTH WAVEWATCH AND SWAN DEPICTING SEAS PEAKING AT 7-8 FT
ON TUESDAY. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED THEN. WINDS
WILL BE BACKING TO THE NE AND N AS BERTHA PASSES WELL TO THE EAST
BUT EXPECT SPEEDS BLO 15 KTS THRU TUESDAY. WINDS SHIFTS WEST AND SW
AND SEAS GRADUALLY SUBSIDE AS A FRONT APPROACHES FROM THE NW THRU
MIDWEEK. THIS COLD FRONT DROPS SOUTH THRU THE AREA LATER THURSDAY.
SW WINDS BRIEFLY INCREASE 15-20 KTS AHEAD OF THE FRONT THURSDAY THEN
SHIFT BACK NW/N AND SLOWLY DECREASE BEHIND THE BNDRY THU NIGHT INTO
FRIDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH MONDAY EVENING FOR NCZ029-044>047-079>081-
090>095-098-103-104.
MARINE...NONE.
&&
$$
SYNOPSIS...CGG
NEAR TERM...CTC
SHORT TERM...CGG
LONG TERM...BTC
AVIATION...CTC/BTC
MARINE...CTC/BTC/CGG
AREA FORECAST DISCUSSION
NWS RALEIGH NC
143 PM EDT SAT AUG 2 2014
.SYNOPSIS...
THE COMBINATION OF A UNSEASONABLY STRONG UPPER TROUGH AND A NEARLY
STATIONARY SURFACE FRONT WILL KEEP VERY MOIST CONDITIONS ACROSS THE
REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM SATURDAY...
VERY WET WEATHER CONTINUING TO AFFECT AREAS MAINLY EAST OF I-95 THIS
MORNING AND INTO THE COASTAL PLAIN. CURRENT RUN OF THE RAP MODEL
NICELY SHOWS THE VARIOUS VORTICITY MAXIMA ACROSS EASTERN NC. THESE
WILL BE THE FOCUS FOR PRECIPITATION THIS MORNING BEFORE TURNING OUR
ATTENTION TO ANOTHER STRONG SHORTWAVE MOVING THROUGH THE UPPER FLOW
THAT SHOULD MOVE INTO THE SW PIEDMONT THIS AFTERNOON AND THEN FOLLOW
A TRACK ALONG US HIGHWAY 1 LATE THIS AFTERNOON AND INTO THE EVENING
HOURS BEFORE EXITING TO THE NORTH. THIS MORNING EXPECT LITTLE
ACTIVITY WEST OF I-95 OTHER THAN SOME LIGHT RAIN AND MIST. A FEW
STRONGER STORMS COULD ROLL INTO OUR EASTERN TIER OF COUNTIES WITH
MORE MODERATE TO HEAVY RAINFALL. WITH THE CAD WEDGE LOCKED IN
PLACE...EXPECT ANOTHER VERY COOL DAY AS FAR AS HIGH TEMPERATURES GO
WITH HIGHS IN THE LOW 70S WEST TO LOW 80S EAST. PREVIOUS DISCUSSION
FOLLOWS. -ELLIS
ADDITIONAL PERTURBATIONS IN THE MOISTURE PLUME WILL INTERACT WITH
AFTERNOON HEATING TO TRIGGER SCATTERED-NUMEROUS SHOWERS AND A FEW T-
STORMS ALONG A STALLED COASTAL TROUGH...CURRENTLY POSITIONED
IMMEDIATELY E-SE OF OUR FORECAST AREA. THIS SFC FEATURE MAY EDGE A
LITTLE ORE TO THE WEST BUT LIKELY NOT AS FAR WEST AS EARLIER MODEL
INDICATIONS DUE TO PRESENCE OF COOL STABLE SFC AIR MASS. MODELS HAVE
A TENDENCY OF WASHING OUT THE CAD AIR MASS TOO QUICKLY AND THIS MAY
BE THE CASE TODAY. THUS...WHILE LATEST GFS DEPICTS BULK SHEAR OF 35-
40KTS ACROSS THE EAST HALF OF OUR FORECAST AREA THIS AFTERNOON ALONG
WITH MLCAPE OF 500-800 J/KG...BELIEVE GREATEST THREAT FOR ISOLATED
STRONG/SEVERE STORM WILL BE OVER OUR EASTERN-SE FRINGE...IN VICINITY
OF THE SFC TROUGH.
DUE TO DEEPER MOISTURE AND BETTER LIFT...STILL A THREAT FOR LOCALLY
HEAVY/EXCESSIVE RAINFALL OVER OUR COASTAL PLAIN COUNTIES. PLAN TO
MAINTAIN CURRENT FLOOD WATCH. POPS THIS AFTERNOON WILL RANGE FROM
SOLID CHANCE WEST TO LIKELY ALONG AND EAST OF HIGHWAY 1. PRECIP
AMOUNTS WILL REMAIN HIGHLY VARIABLE...RANGING FROM A QUARTER OF AN
INCH WITH LOCALIZED AMOUNTS IN EXCESS OF TWO INCHES. THE RISK FOR
AMOUNTS IN EXCESS OF AN INCH APPEARS GREATEST ALONG AND EAST OF
HIGHWAY 1.
TONIGHT...MODEL GUIDANCE DEPICTS ANOTHER DISTURBANCE LIFTING NEWD
ACROSS REGION. THIS FEATURE DIFFICULT AT BEST TO PICK OUT IN THE
WATER VAPOR IMAGERY. WRF AND CAM RADAR DEPICTIONS
SIMILAR...SUGGESTING SCATTERED CONVECTION INTO THE WEE HOURS OF
SUNDAY. PLAN TO MAINTAIN HIGH CHANCE TO LIKELY POPS UNTIL MIDNIGHT
THEN DECREASE TO CHANCE POPS THEREAFTER. -WSS
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 320 AM SATURDAY...
UPPER TROUGH REMAINS ANCHORED TO OUR WEST BUT THERE ARE INDICATIONS
THAT SLIGHTLY DRIER AIR WILL SEEP INTO MOST OF THE PIEDMONT. THIS
WOULD SUPPORT THE IDEA OF SLIGHTLY LOWER POPS COMPARED TO FRIDAY AND
TODAY. MEANWHILE...SFC TROUGH AND MOISTURE PLUME ALOFT WILL MAINTAIN
A LIKELY RISK OF SHOWERS AND STORMS SUNDAY AFTERNOON-EAST...MAINLY
ALONG AND EAST OF I-95. RESIDUAL CAD AIR MASS WILL GRADUALLY MIX OUT
LEADING TO AFTERNOON TEMPS ABOUT 7-10 DEGREES COMPARED TO EXPECTED
HIGH TEMPS TODAY BUT STILL 5-7 DEGREES BELOW NORMAL. IF CAD AIR MASS
HOLDS ON LONGER THAN EXPECTED...THEN MAX TEMPS WILL LIKELY REMAIN IN
THE MID 70S ACROSS PORTIONS OF THE NORTHERN PIEDMONT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 245 AM SATURDAY...
MEDIUM RANGE GUIDANCE HAS BEEN IN RELATIVELY GOOD AGREEMENT IN
RECENT DAYS...PARTICULARLY THROUGH MID-WEEK...WITH MODEL SPREAD MORE
PRONOUNCED BY THE END OF THE PERIOD. A DEAMPLIFYING...POSITIVELY-
TILTED TROUGH ALOFT FROM THE GREAT LAKES TO THE LOWER MS VALLEY
EARLY IN THE PERIOD WILL MOVE EAST AND OFFSHORE IN RESPONSE TO
RENEWED NORTHERN STREAM TROUGH AMPLIFICATION OVER SOUTHEAST CANADA
AND THE NE CONUS MID-LATE WEEK. IN THE LOW LEVELS AND AT THE
SURFACE...THE FRONTAL ZONE OVER THE EASTERN CAROLINAS WILL REMAIN
QUASI-STATIONARY THROUGH MON...THEN DRIFT OFFSHORE THROUGH THE
MIDDLE OF THE WEEK...WHILE A LEE TROUGH BECOMES ESTABLISHED OVER THE
PIEDMONT. ANOTHER COLD FRONT...ONE ASSOCIATED WITH THE
AFOREMENTIONED AMPLIFICATION OF THE NORTHERN STREAM TROUGH...WILL
SAG SOUTH AND MOVE INTO CENTRAL NC ON THU...FOLLOWED BY WEAK RIDGING
OVER THE MIDDLE ATLANTIC STATES BY FRI.
THE RESULT OF THE EVOLVING PATTERN DESCRIBED ABOVE WILL BE A
TRANSITION FROM THE PERTURBED AND MOIST SW FLOW ALOFT - AND ABOVE
AVG PRECIPITATION CHANCES - TO A MORE TYPICAL SUMMERTIME REGIME FOR
NC DURING THE MIDDLE OF THE WEEK. ABOVE NORMAL PRECIPITATION CHANCES
CAN THEN BE EXPECTED INVOF THE SOUTHWARD-SAGGING FRONTAL ZONE ON
THU. LOOK FOR TEMPERATURES TO WARM INTO THE UPPER 80S TO AROUND NEAR
90 DEGREES BY WED...TRENDING DOWN ABOUT A CATEGORY BEHIND THE FRONT
FOR THE END OF THE WEEK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 140 PM SATURDAY...
WE CONTINUE TO BE SOCKED INTO THE LOWER CEILINGS DUE TO THE COLD AIR
DAMMING WEDGE OVER CENTRAL NC. MOST SITES REPORTING IFR CONDITIONS
AT THIS HOUR. SOME AREAS COULD SEE SOME SLIGHT IMPROVEMENT IN
CEILINGS THIS AFTERNOON AS INSOLATION TRIES TO BREAK THROUGH BUT AT
THIS POINT...FAIRLY CONFIDENT THAT CONDITIONS WILL REMAIN SUB-VFR
THROUGH THE TAF PERIOD. PRECIPITATION THIS AFTERNOON WILL BE
GREATEST FROM HIGHWAY 1 EASTWARD WITH KFAY AND KRWI THE MOST LIKELY
TO SEE SOME STRONGER THUNDERSTORM ACTIVITY. WINDS FOR THE MOST PART
REMAIN NORTHEASTERLY AT PLUS OR MINUS 5 KTS. PRECIPITATION IS
EXPECTED TO CONTINUE THROUGH THE EVENING AND OVERNIGHT HOURS WITH
CEILINGS AND VISIBILITIES DETERIORATING FURTHER DURING THE EARLY
MORNING HOURS. MODELS ARE QUICK TO IMPROVE CONDITIONS SUNDAY
AFTERNOON BUT THIS MAY BE PREMATURE...ESPECIALLY IN THE EAST WHERE
CEILINGS SHOULD REMAIN DOWN ALL DAY. THERE IS A SMALL CHANCE THAT
THE TRIAD COULD RETURN TO VFR BEFORE THE END OF THE TAF PERIOD.
LONG TERM: UNSETTLED WEATHER CONTINUES AS THE UPPER LEVEL TROUGH
REMAINS WEST OF THE AREA FOR THE FIRST HALF OF THE WORK WEEK BEFORE
FINALLY BEGINNING TO LIFT OFF TO THE NORTHEAST BY THE END OF THE
WEEK. PRECIPITATION...AND CONSEQUENTLY AVIATION CONDITIONS...WILL
COME AND GO WITH VARIOUS SMALLER IMPULSES EXPECTED TO MOVE THROUGH
THE AREA.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR NCZ028-043-078-088-089.
&&
$$
SYNOPSIS...32
NEAR TERM...ELLIS/WSS
SHORT TERM...WSS
LONG TERM...MWS
AVIATION...ELLIS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
329 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A TROUGH WILL REMAIN STALLED NEAR THE COAST THROUGH THE WEEKEND.
THIS WILL BRING A HEIGHTENED RISK FOR FLOODING AS WIDESPREAD SHOWERS
AND THUNDERSTORMS PLAGUE THE AREA FOR MUCH OF THE WEEKEND. THE
AIRMASS WILL ONLY SLOWLY DRY OUT DURING THE MIDDLE AND LATER
PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
A COUPLE OF NOTABLE CHANGES TO THE FORECAST OVERNIGHT. WITH THE
FRONT NOW DROPPING SOUTHEASTWARD SLOWLY TOWARD THE COAST...THE
COOL WEDGE AIRMASS ACROSS WESTERN AND CENTRAL NORTH CAROLINA WILL
BEGIN TO MOVE INTO THE I-95 CORRIDOR SHORTLY. I HAVE SHAVED A
COUPLE DEGREES OFF FORECAST LOW TEMPS AT DARLINGTON...
FLORENCE...DILLON AND LUMBERTON AS THIS COOLER AIR SLIPS
SOUTHWARD. ALSO...SYNOPTIC MODELS AND THE LATEST FEW HRRR RUNS ARE
SHOWING THE DEVELOPING MASS OF MARINE CONVECTION SOUTH AND
SOUTHEAST OF CAPE FEAR SHOULD MOVE TOWARD SOUTHPORT AND WILMINGTON
OVER THE NEXT 3-4 HOURS. I HAVE BUMPED POPS UP TO 70-80 PERCENT IN
THIS AREA...WHILE TRIMMING THEM BACK INTO THE 30-50 PERCENT RANGE
ACROSS THE PEE DEE REGION WHERE THE LIGHTER SHOWERS CURRENTLY
OBSERVED ON RADAR MAY NOT LAST MUCH LONGER. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
THE COASTAL TROUGH/WARM FRONT MADE PRETTY GOOD INLAND PROGRESS
EARLIER TODAY...REACHING THE INTERSTATE 95 CORRIDOR FROM LUMBERTON
DOWN THROUGH FLORENCE. THE BOUNDARY IS STALLING AND IS EXPECTED TO
DROP BACK TOWARD THE SOUTH CAROLINA COAST LATE TONIGHT...WITH AT
LEAST SOME POTENTIAL IT COULD REACH MYRTLE BEACH BEFORE DAYBREAK.
FOCUSED CONVERGENCE ALONG THE FRONT HAS LED TO A LINE OF SHOWERS AND
EMBEDDED T-STORMS FROM BLADEN COUNTY THROUGH MARION...FLORENCE TO
NEAR ORANGEBURG SC. AN EASTWARD ADVANCING UPPER DISTURBANCE NEAR THE
SAVANNAH RIVER SHOULD HELP NUDGE THE FRONT AND A COLLOCATED DEEP
MOISTURE CHANNEL EASTWARD TONIGHT...REACHING THE COAST LATE.
CHANGES WITH THIS UPDATE WERE FAIRLY MINOR...WITH TWEAKS TO WIND
DIRECTIONS AND HOURLY POPS/WX MOST SIGNIFICANT. PREVIOUS DISCUSSION
FROM 300 PM FOLLOWS...
TROUGH REMAINS STALLED ALONG THE COAST WHILE DEEP GULF MOISTURE
CONTINUES TO SPREAD NORTHEAST. ALONG WITH LOW LEVEL CONVERGENCE
ASSOCIATED WITH THE BOUNDARY...WEAK DIVERGENCE ALOFT CONTINUES. THIS
COUPLED WITH MODERATE INSTABILITY...CAPE IS 1000-1500 J/KG...HAS
BEEN PRODUCING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA.
EXPECT ACTIVITY TO CONTINUE AND INCREASE IN COVERAGE FOR THE
REMAINDER OF THE AFTERNOON. LOSS OF DIURNAL HEATING SHOULD BRING
ABOUT A DECREASE IN COVERAGE BUT DO NOT THINK ACTIVITY WILL
COMPLETELY DISAPPEAR THIS EVENING.
TROUGH WILL REMAIN STALLED ALONG OR JUST INLAND OF THE COAST WITH
PRECIPITABLE WATER VALUES HANGING AROUND 2 INCHES OVERNIGHT.
ADDITIONALLY THERE APPEARS TO BE A WEAK DEFORMATION ZONE EAST OF THE
AREA. THIS FEATURE WILL SLOWLY DRIFT WEST THIS EVENING AND OVERNIGHT
AS THE MID LEVEL WESTERN ATLANTIC RIDGE EXPANDS. BASED ON THIS HAVE
HELD ONTO LIKELY POP ALONG THE COAST ALL NIGHT BUT DROP INLAND AREAS
TO HIGH CHANCE AROUND MID NIGHT. MID LEVEL PATTERN AND LACK OF
SURFACE LOW IN EASTERN TX SUGGESTS THE TROUGH WILL REMAIN STALLED
ALONG THE COAST THROUGH THE END OF THE PERIOD AND THIS IS WHERE THE
HIGHEST QPF SHOULD BE FOUND.
CLOUD COVER AND MOISTURE ALONG WITH BOUNDARY LAYER WINDS WILL KEEP
LOWS NEAR TO ABOVE CLIMO. WEST OF THE BOUNDARY LOWS WILL BE CLOSE TO
CLIMO...AROUND 70. ON THE EAST SIDE OF THE BOUNDARY MODEST ONSHORE
FLOW WILL KEEP TEMPERATURES IN THE MID 70S.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SOME QUESTION AS TO WHETHER OR NOT FLOOD WATCH
WILL REMAIN IN EFFECT UNTIL ITS CURRENT EXPIRATION TIME OF SUNDAY
EVENING. THROUGH MUCH OF SUNDAY MOISTURE REMAINS COPIOUS WITH PWAT
VALUES 2.00-2.2 INCHES. WHAT MAY BE LACKING HOWEVER IS DEEP FORCING
FOR ASCENT. BEST PVA APPEARS OVER BY 18Z AND THE UPPER RIGHT
ENTRANCE DIVERGENCE ON THE WANE. MODEL GUIDANCE QPF NOW LOOKING MORE
LACKLUSTER. THERE IS LITTLE VALUE IN MAKING CHANGES TO THE WATCH AT
THIS POINT HOWEVER...DUE TO THE UNCERTAINTY INVOLVED AND ALSO THE
POSSIBILITY THAT SHOULD SATURDAY TURN OUT WET AS ANTICIPATED THEN BY
SUNDAY EVEN MINOR RAIN AMOUNTS MAY LEAD TO SOME FLOODING ISSUES WITH
THE SATURATED SOILS. DEEPEST MOISTURE SHIFTING EAST SOME ON MONDAY
AND THE THREAT FOR HEAVY RAIN MAY DO THE SAME. FOR NOW HAVE
DISCOUNTED THE LARGE WAVE SHOWN IN THE WRF. THE MODEL IS SEEMING
HAVING TROUBLE RESOLVING THE UPPER LOW CURRENTLY IN THE BAHAMAS AND
BERTHA...AND ALLOWING FOR THE FORMER TO BECOME THE DOMINANT
CIRCULATION. RAIN CHANCES WILL DIMINISH BUT LINGER NEVERTHELESS INTO
MONDAY NIGHT AS THE WEAK MID LEVEL TROUGH AXIS REMAINS TO OUR WEST
AND THE SURFACE BOUNDARY CAN STILL BE MADE OUT NEAR THE COAST ON
SURFACE PROGS. DAYTIME HIGHS VERY SUPPRESSED AGAIN ON SUNDAY BUT
SHOW SOME RECOVERY TOWARDS CLIMATOLOGY BY MONDAY.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM FRIDAY...WEAKENING MID LEVEL TROUGHINESS REMAINS TO OUR
WEST TUESDAY AND WEDNESDAY. THERE SHOULD BE AN INCREASINGLY WESTERLY
FLOW DEVELOPING INSTEAD OF SOUTHWESTERLY FLOW HOWEVER YIELDING A
TREND TOWARDS MORE CLIMATOLOGICAL TEMPERATURES AND RAIN CHANCES. AS
THE TROUGH MOVES OFF THE COAST ON THURSDAY A WEAK FRONT MAY PUSH
THROUGH BUT IT IS TOUGH TO TELL THIS FAR OUT IF IT HAS ANY REAL
EFFECTS ON SENSIBLE WEATHER. BUILDING MID LEVEL RIDGE OVER GOMEX
THURSDAY AND FRIDAY WITH WEAK/TYPICAL SURFACE FLOW SHOULD BRING
FEWER THUNDERSTORMS AND HIGHER TEMPS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...LIGHT RAIN IS WINDING DOWN NEAR KFLO/KLBT. CIGS ARE IFR
AT THOSE TERMINALS AND EXPECTED TO REMAIN SO THROUGH 14-15Z...WITH A
GOOD CHANCE OF LIFR CIGS/IFR VSBYS BY 08Z. CONVECTION IS INCREASING
AT THE COASTAL TERMINALS...WITH SOME ISOLATED LIGHTNING STRIKES JUST
OFFSHORE MYR.
MODEL SOLUTIONS VARY WIDELY ON THE EVOLUTION OF THE FRONTAL BOUNDARY
NEAR KFLO/KLBT...THUS CONFIDENCE IS LOW. ATTM WILL SWING THE FRONT
BACK TOWARDS THE COAST WITH THE PASSAGE OF AN UPPER IMPULSE. THIS
SHOULD ALLOW FOR AN INCREASE IN CONVECTION AT THE COASTAL TERMINALS
EARLY THIS MORNING WITH ISOLATED THUNDER. IFR/LIFR CONDITIONS WILL
EVENTUALLY SPREAD EAST AND AFFECT THE COASTAL TERMINALS EXCEPT KILM
TOWARDS SUNRISE. HIGHEST CONFIDENCE OF LIFR/IFR CIGS/VSBYS WILL BE
AT KFLO/KLBT.
LIFR/IFR CIGS IMPROVE TO MVFR BY MID MORNING. SHRA/TSRA RE-DEVELOP
BY LATE MORNING...WITH BEST POTENTIAL FOR VCTS ALONG THE BOUNDARY
NEAR THE COASTAL TERMINALS.
EXTENDED OUTLOOK...SHRA/TSRA LIKELY WITH PERIODS OF MVFR CONDITIONS
THROUGH TUESDAY AS A FRONT STALLS AND FINALLY DISSIPATES OVER THE
EASTERN CAROLINAS. A CHANCE OF SHOWERS CONTINUES ON WEDNESDAY LATE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
ONLY MINOR CHANGES ARE NEEDED TO WIND AND SEA FORECASTS THROUGH
DAYBREAK. RADAR SHOWS DEVELOPING SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS ACROSS THE OFFSHORE WATERS SOUTHEAST OF CAPE FEAR. THESE
SHOWERS AND STORMS ARE ANTICIPATED TO BECOME MORE NUMEROUS OVER
THE NEXT FEW HOURS AS THEY MOVE TOWARD LAND. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
THE WARM FRONT/COASTAL FRONT HAS MOVED INLAND THROUGH ELIZABETHTOWN
AND WHITEVILLE WITH SOUTH WINDS REPORTED AT ALL WEATHER OBS STATIONS
ALONG THE COAST. MODELS ARE SHOWING THE BOUNDARY MAY REVERSE COURSE
OVERNIGHT AND DROP BACK DOWN TOWARD THE COAST. MY LATEST FORECAST
BRINGS IT FAIRLY CLOSE TO MYRTLE BEACH AGAIN LATE TONIGHT. THE
PRESSURE GRADIENT IS AWFULLY "BAGGY" IN THE VICINITY OF THE FRONT
AND THIS SHOULD RESULT IN WIND SPEEDS DIMINISHING
OVERNIGHT...PARTICULARLY ALONG THE SOUTH CAROLINA COAST. WINDS OF
10-15 KNOTS SHOULD CONTINUE ALONG NORTH CAROLINA COAST MUCH OF THE
NIGHT. SEAS ARE CURRENTLY 3 FEET AT THE SUNSET BEACH BUOY...AND JUST
UNDER 4 FEET AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY AND OFFSHORE
LEJEUNE BUOY...NECESSITATING ONLY A SLIGHT INCREASE IN WAVE
FORECASTS. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
COASTAL TROUGH STALLED NEAR THE COAST KEEPS SOUTHEAST FLOW IN PLACE
OVER THE WATERS THROUGH THE END OF THE PERIOD. LITTLE CHANGE TO THE
GRADIENT IS EXPECTED AND WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE.
PROLONGED ONSHORE FLOW WILL KEEP SEAS 3 TO 4 FT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SOUTHERLY WINDS EXPECTED FOR MOST OF THE
PERIOD WITH A FRONTAL BOUNDARY WEAKENING VERY NEAR THE COAST. THE
SURFACE TROUGH ASSOCIATED WITH THE BOUNDARY WILL KEEP WIND SPEEDS
FAIRLY LIGHT ESPECIALLY COME MONDAY AS THE FRONT WEAKENS EVEN MORE.
THERE IS A MODEL SOLUTION THAT IS CURRENTLY BEING DISCOUNTED AS
ERRONEOUS...IT GENERATES A STRENGTHENING LOW THAT MOVES PARALLEL TO
THE COAST. THIS SOLUTION WOULD IMPLY A TURN TO A MORE NORTHERLY
FLOW AND HIGHER WIND SPEEDS ALONG WITH BUILDING SEAS. THIS WILL ONLY
OCCUR IF THE UPPER LOW NOW IN THE BAHAMAS GENERATES A SURFACE LOW
THAT ENDS UP DOMINATING THE WIND FIELDS OVER TROPICAL SYSTEM
BERTHA...WHICH WILL BE PASSING EVEN FURTHER OFFSHORE. THERE COULD BE
A COMPLEX INTERACTION BETWEEN THE TWO...BUT THE CURRENT FORECAST IS
FOR THE WELL OFFSHORE BERTHA TO KEEP ITS IDENTITY. ANY SWELLS
ASSOCIATED WITH THIS SYSTEM WILL LIKELY IMPACT THE AREA JUST BEYOND
THE SHORT TERM PERIOD.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...BERTHA MAKES ITS CLOSEST APPROACH...AND IT
ISN`T GOING TO BE A VERY CLOSE ONE...ON TUESDAY. WINDS SHOULD RETAIN
THEIR SOUTHERLY COMPONENT BUT MAY VARY FROM SW TO SE. A LITTLE SWELL
ENERGY TO AFFECT THE LOCAL AREA WITH SOME SLIGHTLY HIGHER SEAS...BUT
THIS WILL OBVIOUSLY HINGE ON THE STRENGTH AND TRACK. FOR NOW IT
SEEMS WE MAY AVOID ANY HEADLINES. BACK TO CLIMO NORMS ON WEDNESDAY
WITH WEST ATLANTIC HIGH PRESSURE ONLY WEAKLY EXERTING INFLUENCE
LOCALLY FOR A LIGHT SW FLOW.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH SUNDAY EVENING FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH SUNDAY EVENING FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...RJD
NEAR TERM...REK/III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...REK/MRR
MARINE...REK/RJD/III
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
131 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A TROUGH WILL REMAIN STALLED NEAR THE COAST THROUGH THE WEEKEND.
THIS WILL BRING A HEIGHTENED RISK FOR FLOODING AS WIDESPREAD SHOWERS
AND THUNDERSTORMS PLAGUE THE AREA FOR MUCH OF THE WEEKEND. THE
AIRMASS WILL ONLY SLOWLY DRY OUT DURING THE MIDDLE AND LATER
PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
A COUPLE OF NOTABLE CHANGES TO THE FORECAST OVERNIGHT. WITH THE
FRONT NOW DROPPING SOUTHEASTWARD SLOWLY TOWARD THE COAST...THE
COOL WEDGE AIRMASS ACROSS WESTERN AND CENTRAL NORTH CAROLINA WILL
BEGIN TO MOVE INTO THE I-95 CORRIDOR SHORTLY. I HAVE SHAVED A
COUPLE DEGREES OFF FORECAST LOW TEMPS AT DARLINGTON...
FLORENCE...DILLON AND LUMBERTON AS THIS COOLER AIR SLIPS
SOUTHWARD. ALSO...SYNOPTIC MODELS AND THE LATEST FEW HRRR RUNS ARE
SHOWING THE DEVELOPING MASS OF MARINE CONVECTION SOUTH AND
SOUTHEAST OF CAPE FEAR SHOULD MOVE TOWARD SOUTHPORT AND WILMINGTON
OVER THE NEXT 3-4 HOURS. I HAVE BUMPED POPS UP TO 70-80 PERCENT IN
THIS AREA...WHILE TRIMMING THEM BACK INTO THE 30-50 PERCENT RANGE
ACROSS THE PEE DEE REGION WHERE THE LIGHTER SHOWERS CURRENTLY
OBSERVED ON RADAR MAY NOT LAST MUCH LONGER. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
THE COASTAL TROUGH/WARM FRONT MADE PRETTY GOOD INLAND PROGRESS
EARLIER TODAY...REACHING THE INTERSTATE 95 CORRIDOR FROM LUMBERTON
DOWN THROUGH FLORENCE. THE BOUNDARY IS STALLING AND IS EXPECTED TO
DROP BACK TOWARD THE SOUTH CAROLINA COAST LATE TONIGHT...WITH AT
LEAST SOME POTENTIAL IT COULD REACH MYRTLE BEACH BEFORE DAYBREAK.
FOCUSED CONVERGENCE ALONG THE FRONT HAS LED TO A LINE OF SHOWERS AND
EMBEDDED T-STORMS FROM BLADEN COUNTY THROUGH MARION...FLORENCE TO
NEAR ORANGEBURG SC. AN EASTWARD ADVANCING UPPER DISTURBANCE NEAR THE
SAVANNAH RIVER SHOULD HELP NUDGE THE FRONT AND A COLLOCATED DEEP
MOISTURE CHANNEL EASTWARD TONIGHT...REACHING THE COAST LATE.
CHANGES WITH THIS UPDATE WERE FAIRLY MINOR...WITH TWEAKS TO WIND
DIRECTIONS AND HOURLY POPS/WX MOST SIGNIFICANT. PREVIOUS DISCUSSION
FROM 300 PM FOLLOWS...
TROUGH REMAINS STALLED ALONG THE COAST WHILE DEEP GULF MOISTURE
CONTINUES TO SPREAD NORTHEAST. ALONG WITH LOW LEVEL CONVERGENCE
ASSOCIATED WITH THE BOUNDARY...WEAK DIVERGENCE ALOFT CONTINUES. THIS
COUPLED WITH MODERATE INSTABILITY...CAPE IS 1000-1500 J/KG...HAS
BEEN PRODUCING SHOWERS AND THUNDERSTORMS ACROSS MUCH OF THE AREA.
EXPECT ACTIVITY TO CONTINUE AND INCREASE IN COVERAGE FOR THE
REMAINDER OF THE AFTERNOON. LOSS OF DIURNAL HEATING SHOULD BRING
ABOUT A DECREASE IN COVERAGE BUT DO NOT THINK ACTIVITY WILL
COMPLETELY DISAPPEAR THIS EVENING.
TROUGH WILL REMAIN STALLED ALONG OR JUST INLAND OF THE COAST WITH
PRECIPITABLE WATER VALUES HANGING AROUND 2 INCHES OVERNIGHT.
ADDITIONALLY THERE APPEARS TO BE A WEAK DEFORMATION ZONE EAST OF THE
AREA. THIS FEATURE WILL SLOWLY DRIFT WEST THIS EVENING AND OVERNIGHT
AS THE MID LEVEL WESTERN ATLANTIC RIDGE EXPANDS. BASED ON THIS HAVE
HELD ONTO LIKELY POP ALONG THE COAST ALL NIGHT BUT DROP INLAND AREAS
TO HIGH CHANCE AROUND MID NIGHT. MID LEVEL PATTERN AND LACK OF
SURFACE LOW IN EASTERN TX SUGGESTS THE TROUGH WILL REMAIN STALLED
ALONG THE COAST THROUGH THE END OF THE PERIOD AND THIS IS WHERE THE
HIGHEST QPF SHOULD BE FOUND.
CLOUD COVER AND MOISTURE ALONG WITH BOUNDARY LAYER WINDS WILL KEEP
LOWS NEAR TO ABOVE CLIMO. WEST OF THE BOUNDARY LOWS WILL BE CLOSE TO
CLIMO...AROUND 70. ON THE EAST SIDE OF THE BOUNDARY MODEST ONSHORE
FLOW WILL KEEP TEMPERATURES IN THE MID 70S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...A FLOOD WATCH IS IN EFFECT THROUGH SUNDAY. A
COASTAL TROUGH WILL REMAIN POSITIONED ALONG THE CAROLINA COAST
THIS PERIOD. WHILE SOME OF THE MODELS ARE INDICATING THE TROUGH
WILL VERY SLOWLY MOVE INLAND...THE MID-LEVEL FLOW SUGGESTS
OTHERWISE. AN EXTREMELY DEEP S/SW FLOW WILL REMAIN LOCKED IN PLACE
ALONG WITH A MOIST COLUMN THROUGH A VERY DEEP LAYER. THE PERSISTENT
UPPER DIFFLUENCE WITHIN THE ENTRANCE REGION OF JET STREAK ACROSS
THE NORTHEAST AND THE LOW LEVEL CONVERGENCE ALONG THE TROUGH WILL
PROVIDE THE NECESSARY LIFT FOR A LARGE SCALE...SIGNIFICANT
RAINFALL EVENT. WE ARE EXPECTING TOTAL RAINFALL AMOUNTS TO AVERAGE
2 TO 4 INCHES WITH UPWARDS OF 4 AND 5 INCHES ALONG COASTAL CAPE
FEAR. HOWEVER...HIGHER AMOUNTS ARE POSSIBLE AND GIVEN THE GROUND
IS WET FROM A VERY WET JULY...WE FEEL THE RISK FOR SIGNIFICANT
FLOODING IS HIGH ENOUGH TO WARRANT A FLOOD WATCH.
THE CLOUDS...RAIN...AND LOWERED THICKNESSES WILL KEEP HIGHS BELOW
NORMAL FOR EARLY-AUGUST...BUT AT THE SAME TIME MAINTAIN NORMAL OR
SLIGHTLY ABOVE NORMAL LOWS. EXPECT HIGHS IN THE LOWER TO MID 80S
BOTH DAYS...AND LOWS IN THE LOWER TO MID 70S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...MID-LEVEL TROUGH AXIS WILL REMAIN WEST OF
THE AREA MONDAY AND TUESDAY...RESULTING IN A CONTINUED AMPLE
SUPPLY OF MOISTURE TO ENHANCE THE POTENTIAL FOR SHOWERS AND TSTMS.
SURFACE CONVERGENCE WILL BE PROVIDED BY THE STALLED FRONTAL
BOUNDARY WHICH WILL LINGER ALONG THE COAST AS WELL AS WEAK WAVES
OF LOW PRESSURE WHICH MODELS INDICATE MAY DEVELOP ALONG THE
BOUNDARY. EXPECT TEMPS WILL BE HELD IN CHECK BY CLOUD COVER
MONDAY...BUT LESS SO TUESDAY-WEDNESDAY. THE MID-LEVEL TROUGH AXIS
WILL SLOWLY TRANSITION EAST AND ALLOW SOME DRIER AIR TO FILTER IN
BY MIDWEEK...SO ALTHOUGH POPS WILL BE INCLUDED EACH DAY...TREND
WILL BE DOWNWARD. ANOTHER WEAK FRONTAL BOUNDARY WILL DROP INTO THE
AREA THURSDAY AND LINGER INTO FRIDAY...SO SLIGHT/LOW CHANCE POPS
WILL BE WARRANTED THOSE DAYS AS WELL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...LIGHT RAIN IS WINDING DOWN NEAR KFLO/KLBT. CIGS ARE IFR
AT THOSE TERMINALS AND EXPECTED TO REMAIN SO THROUGH 14-15Z...WITH A
GOOD CHANCE OF LIFR CIGS/IFR VSBYS BY 08Z. CONVECTION IS INCREASING
AT THE COASTAL TERMINALS...WITH SOME ISOLATED LIGHTNING STRIKES JUST
OFFSHORE MYR.
MODEL SOLUTIONS VARY WIDELY ON THE EVOLUTION OF THE FRONTAL BOUNDARY
NEAR KFLO/KLBT...THUS CONFIDENCE IS LOW. ATTM WILL SWING THE FRONT
BACK TOWARDS THE COAST WITH THE PASSAGE OF AN UPPER IMPULSE. THIS
SHOULD ALLOW FOR AN INCREASE IN CONVECTION AT THE COASTAL TERMINALS
EARLY THIS MORNING WITH ISOLATED THUNDER. IFR/LIFR CONDITIONS WILL
EVENTUALLY SPREAD EAST AND AFFECT THE COASTAL TERMINALS EXCEPT KILM
TOWARDS SUNRISE. HIGHEST CONFIDENCE OF LIFR/IFR CIGS/VSBYS WILL BE
AT KFLO/KLBT.
LIFR/IFR CIGS IMPROVE TO MVFR BY MID MORNING. SHRA/TSRA RE-DEVELOP
BY LATE MORNING...WITH BEST POTENTIAL FOR VCTS ALONG THE BOUNDARY
NEAR THE COASTAL TERMINALS.
EXTENDED OUTLOOK...SHRA/TSRA LIKELY WITH PERIODS OF MVFR CONDITIONS
THROUGH TUESDAY AS A FRONT STALLS AND FINALLY DISSIPATES OVER THE
EASTERN CAROLINAS. A CHANCE OF SHOWERS CONTINUES ON WEDNESDAY LATE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:30 AM SATURDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSIONS FOLLOW:
ONLY MINOR CHANGES ARE NEEDED TO WIND AND SEA FORECASTS THROUGH
DAYBREAK. RADAR SHOWS DEVELOPING SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS ACROSS THE OFFSHORE WATERS SOUTHEAST OF CAPE FEAR. THESE
SHOWERS AND STORMS ARE ANTICIPATED TO BECOME MORE NUMEROUS OVER
THE NEXT FEW HOURS AS THEY MOVE TOWARD LAND. PREVIOUS DISCUSSION
FROM 730 PM FOLLOWS...
THE WARM FRONT/COASTAL FRONT HAS MOVED INLAND THROUGH ELIZABETHTOWN
AND WHITEVILLE WITH SOUTH WINDS REPORTED AT ALL WEATHER OBS STATIONS
ALONG THE COAST. MODELS ARE SHOWING THE BOUNDARY MAY REVERSE COURSE
OVERNIGHT AND DROP BACK DOWN TOWARD THE COAST. MY LATEST FORECAST
BRINGS IT FAIRLY CLOSE TO MYRTLE BEACH AGAIN LATE TONIGHT. THE
PRESSURE GRADIENT IS AWFULLY "BAGGY" IN THE VICINITY OF THE FRONT
AND THIS SHOULD RESULT IN WIND SPEEDS DIMINISHING
OVERNIGHT...PARTICULARLY ALONG THE SOUTH CAROLINA COAST. WINDS OF
10-15 KNOTS SHOULD CONTINUE ALONG NORTH CAROLINA COAST MUCH OF THE
NIGHT. SEAS ARE CURRENTLY 3 FEET AT THE SUNSET BEACH BUOY...AND JUST
UNDER 4 FEET AT THE NEARSHORE WRIGHTSVILLE BEACH BUOY AND OFFSHORE
LEJEUNE BUOY...NECESSITATING ONLY A SLIGHT INCREASE IN WAVE
FORECASTS. PREVIOUS DISCUSSION FROM 300 PM FOLLOWS...
COASTAL TROUGH STALLED NEAR THE COAST KEEPS SOUTHEAST FLOW IN PLACE
OVER THE WATERS THROUGH THE END OF THE PERIOD. LITTLE CHANGE TO THE
GRADIENT IS EXPECTED AND WINDS WILL REMAIN IN THE 10 TO 15 KT RANGE.
PROLONGED ONSHORE FLOW WILL KEEP SEAS 3 TO 4 FT.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...A COASTAL TROUGH WILL LIKELY NOT MOVE MUCH
THROUGH THE PERIOD AND WE EXPECT THE TROUGH WILL BE OVER THE AREA
OR JUST TO THE WEST THROUGH SUNDAY NIGHT. THE WIND DIRECTION ON THE
WEST SIDE OF THE TROUGH WILL BE MORE NORTHERLY WHILE WINDS ON THE
EAST SIDE WILL BE MORE SOUTHERLY. AT THIS TIME...EXPECT THE WIND
DIRECTION ACROSS THE WATERS WILL BE PREDOMINATELY FROM A S OR SE
DIRECTION. THE PROXIMITY OF THE TROUGH SHOULD KEEP WIND SPEEDS
FROM EXCEEDING 10 TO 15 KT. SEAS WILL BE 3 TO 4 FT WITH PERHAPS
SOME 5 FT SEAS DEVELOPING ACROSS THE OUTERMOST WATERS LATE IN THE
WEEKEND. A STILL RATHER WEAK 9 TO 11 SECOND SE SWELL WILL BE PRESENT.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...SURFACE FLOW IS EXPECTED TO REMAIN
RELATIVELY LIGHT AS THE PRESSURE GRADIENT WILL REMAIN WEAK THROUGH
THE PERIOD. HOWEVER THERE IS UNCERTAINTY IN THE WIND DIRECTION
DURING THIS TIME AS A STALLED FRONTAL BOUNDARY WILL LINGER ALONG
THE COAST. A 3 TO PERHAPS 4 FOOT SWELL WITH 11 SECOND PERIOD WILL
BE POSSIBLE TUESDAY-WEDNESDAY FROM BERTHA...WHICH IS CURRENTLY
FORECAST TO BE MOVING NORTHWARD WELL OFF THE CAROLINA COAST AT
THAT TIME.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH SUNDAY EVENING FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH SUNDAY EVENING FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...RJD
NEAR TERM...REK/III
SHORT TERM...RJD
LONG TERM...III
AVIATION...REK/MRR
MARINE...REK/RJD/III
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
611 PM EDT SAT AUG 2 2014
.SYNOPSIS...
AN UPPER LEVEL LOW CROSSES TONIGHT INTO SUNDAY. WEAK HIGH PRESSURE
PASSES EARLY NEXT WEEK. A COLD FRONT CROSSES MID WEEK. A STRONGER
HIGH THEN BUILDS IN TO CLOSE OUT THE WORK WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
600 PM UPDATE...
EARLY UPDATE TO ADJUST TO CATEGORICAL POPS WITH THE MAIN LINE OF
SHOWERS AND THUNDERSTORMS THIS EVENING...AND TO BETTER TIME THE
LINE AS IT CROSSES WEST TO EAST. STORMS SHOWING SIGNS OF
WEAKENING...AND EXPECT THIS TREND TO CONTINUE AS THEY CONTINUE
EASTWARD THIS EVENING...WITH LESS INSTABILITY NOTED FURTHER EAST
OF THE I79 CORRIDOR.
PREVIOUS DISCUSSION...
THE HRRR SEEMS TO HAVE THE BEST HANDLE ON WHAT IS CURRENTLY GOING
ON ALTHOUGH NONE OF THE MODELS SEEM TO BE GRASPING WHAT APPEARS TO
BE A LINE OF SHOWERS AND THUNDERSTORMS JUST AHEAD OF AN UPPER
LEVEL TROUGH APPROACHING THE MIDDLE OHIO VALLEY. THAT TROUGH
BECOMES A CLOSED LOW AT TIMES AS IT MOVES ACROSS TONIGHT. IT THEN
OPENS UP AND PULLS OUT OF THE AREA ON SUNDAY.
HAVE THE ASSOCIATED CONVECTION WANING WITH THE SUNSET TONIGHT...THEN
REFIRING A BIT DURING THE HEATING OF THE DAY SUNDAY...BEFORE
TRENDING DRIER FROM THE W LATE IN THE DAY...AS THE SYSTEM BEGINS
PULLING OUT OF THE AREA. WILL HAVE TO WATCH THE SLOWER CELL
MOVEMENT AS THE FLOW IN THE COLUMN WEAKENS UNDERNEATH THE UPPER
LEVEL TROUGH AXIS.
TEMPERATURES LOOKED GOOD IN LIGHT OF THE LATEST GUIDANCE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SHORTWAVE ENERGY PUSHES OFF TO THE EAST BEGINNING OF THE
PERIOD...WITH DRIER WEATHER AS HIGH PRESSURE BUILDS IN. FLOW WILL
TURN MORE SOUTHEASTERLY LATER IN THE DAY MONDAY...WITH UPSLOPE
SHOWERS POSSIBLE OVER THE HIGHER TERRAIN COUNTIES.
UNSETTLED WEATHER WILL RETURN TO THE AREA TUESDAY THROUGH THURSDAY
AS A FRONTAL BOUNDARY SAGS SOUTH ACROSS THE AREA. STILL SOME
TIMING...PLACEMENT DIFFERENCES AMONG THE MODELS...AND FOLLOWED THE
TREND OF THE ECMWF IN TERMS OF POPS...WHICH IS SLOWER...AND NOT AS
COOL AS THE GFS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UNCERTAINTY EXISTS IN THE LONG TERM PERIOD CONCERNING THE SOUTHWARD
EXTENT OF A FRONTAL BOUNDARY MID WEEK...AND THE APPROACH OF ANOTHER
SYSTEM...THAT SHOULD AFFECT THE AREA TOWARDS THE END OF THE PERIOD.
KEPT A BROAD BRUSH OF POPS...AND OVERALL UNSETTLED WEATHER TREND
DURING THE EXTENDED PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THUNDERSTORMS ARE LIKELY TOO INCREASE IN AREA COVERAGE IN THE HEAT
OF THE AFTERNOON...AND IN RESPONSE TO AN UPPER LEVEL TROUGH
APPROACHING FROMM THE W. THESE STORMS WILL DISSIPATE AFTER SUNSET.
DENSE VALLEY FOG IS LIKELY OVERNIGHT INTO SUNDAY MORNING. MVFR
STRATOCU MAY ALSO SHOW UP OVER EASTERN WV TONIGHT.
SUNDAY WILL BE A MAINLY VFR DAY ONCE THE FOG BURNS OFF...AS THE
UPPER LEVEL TROUGH PULLS OUT OF THE AREA...WITH ISOLATED TO
SCATTERED CONVECTION MOVING EWD.
FLOW SFC AND ALOFT WILL BE LIGHT AND VARIABLE...BECOMING LIGHT NW
ALOFT OVERNIGHT AND SUNDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z MONDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND PLACEMENT OF CONVECTION MAY VARY
INTO THIS EVENING. TIMING AND EXTENT OF FOG MAY VARY...ALTHOUGH
CONFIDENCE IN DENSE FOG IN GENERAL IS HIGH.
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 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
CRW CONSISTENCY H H H M M H H M M L L L
HTS CONSISTENCY H M M H H H H M M H L L
BKW CONSISTENCY H H H H H M M M H H H H
EKN CONSISTENCY H H H H H M M L L L L L
PKB CONSISTENCY H M M M M H H H M H L L
CKB CONSISTENCY H H H M M M H M M H L L
AFTER 00Z MONDAY...
VLIFR IN DENSE RIVER VALLEY FOG OVERNIGHT AND EARLY MORNING AS FOG
SEASON IS UPON US...AND WEAK HIGH PRESSURE BUILDS ACROSS THE AREA
EARLY NEXT WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...TRM/50
SHORT TERM...SL
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
219 PM EDT SAT AUG 2 2014
.SYNOPSIS...
AN UPPER LEVEL LOW CROSSES TONIGHT INTO SUNDAY. WEAK HIGH PRESSURE
PASSES EARLY NEXT WEEK. A COLD FRONT CROSSES MID WEEK. A STRONGER
HIGH THEN BUILDS IN TO CLOSE OUT THE WORK WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE HRRR SEEMS TO HAVE THE BEST HANDLE ON WHAT IS CURRENTLY GOING ON
ALTHOUGH NONE OF THE MODELS SEEM TO BE GRASPING WHAT APPEARS TO BE A
LINE OF SHOWERS AND THUNDERSTORMS JUST AHEAD OF AN UPPER LEVEL
TROUGH APPROACHING THE MIDDLE OHIO VALLEY. THAT TROUGH BECOMES A
CLOSED LOW AT TIMES AS IT MOVES ACROSS TONIGHT. IT THEN OPENS UP
AND PULLS OUT OF THE AREA ON SUNDAY.
HAVE THE ASSOCIATED CONVECTION WANING WITH THE SUNSET TONIGHT...THEN
REFIRING A BIT DURING THE HEATING OF THE DAY SUNDAY...BEFORE
TRENDING DRIER FROM THE W LATE IN THE DAY...AS THE SYSTEM BEGINS
PULLING OUT OF THE AREA. WILL HAVE TO WATCH THE SLOWER CELL
MOVEMENT AS THE FLOW IN THE COLUMN WEAKENS UNDERNEATH THE UPPER
LEVEL TROUGH AXIS.
TEMPERATURES LOOKED GOOD IN LIGHT OF THE LATEST GUIDANCE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
SHORTWAVE ENERGY PUSHES OFF TO THE EAST BEGINNING OF THE
PERIOD...WITH DRIER WEATHER AS HIGH PRESSURE BUILDS IN. FLOW WILL
TURN MORE SOUTHEASTERLY LATER IN THE DAY MONDAY...WITH UPSLOPE
SHOWERS POSSIBLE OVER THE HIGHER TERRAIN COUNTIES.
UNSETTLED WEATHER WILL RETURN TO THE AREA TUESDAY THROUGH THURSDAY
AS A FRONTAL BOUNDARY SAGS SOUTH ACROSS THE AREA. STILL SOME
TIMING...PLACEMENT DIFFERENCES AMONG THE MODELS...AND FOLLOWED THE
TREND OF THE ECMWF IN TERMS OF POPS...WHICH IS SLOWER...AND NOT AS
COOL AS THE GFS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
UNCERTAINTY EXISTS IN THE LONG TERM PERIOD CONCERNING THE SOUTHWARD
EXTENT OF A FRONTAL BOUNDARY MID WEEK...AND THE APPROACH OF ANOTHER
SYSTEM...THAT SHOULD AFFECT THE AREA TOWARDS THE END OF THE PERIOD.
KEPT A BROAD BRUSH OF POPS...AND OVERALL UNSETTLED WEATHER TREND
DURING THE EXTENDED PERIOD.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
THUNDERSTORMS ARE LIKELY TOO INCREASE IN AREA COVERAGE IN THE HEAT
OF THE AFTERNOON...AND IN RESPONSE TO AN UPPER LEVEL TROUGH
APPROACHING FROMM THE W. THESE STORMS WILL DISSIPATE AFTER SUNSET.
DENSE VALLEY FOG IS LIKELY OVERNIGHT INTO SUNDAY MORNING. MVFR
STRATOCU MAY ALSO SHOW UP OVER EASTERN WV TONIGHT.
SUNDAY WILL BE A MAINLY VFR DAY ONCE THE FOG BURNS OFF...AS THE
UPPER LEVEL TROUGH PULLS OUT OF THE AREA...WITH ISOLATED TO
SCATTERED CONVECTION MOVING EWD.
FLOW SFC AND ALOFT WILL BE LIGHT AND VARIABLE...BECOMING LIGHT NW
ALOFT OVERNIGHT AND SUNDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND PLACEMENT OF CONVECTION MAY VARY
INTO THIS EVENING. TIMING AND EXTENT OF FOG MAY VARY...ALTHOUGH
CONFIDENCE IN DENSE FOG IN GENERAL IS HIGH.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M L
HTS CONSISTENCY H H H H H H H H H M M L
BKW CONSISTENCY H H H H H H H M M M H H
EKN CONSISTENCY H H H H H H H H M L L L
PKB CONSISTENCY H H H H H H H H H H M H
CKB CONSISTENCY H H H H H H H H H M M L
AFTER 18Z SUNDAY...
VLIFR IN DENSE RIVER VALLEY FOG OVERNIGHT AND EARLY MORNING AS FOG
SEASON IS UPON US...AND WEAK HIGH PRESSURE BUILDS ACROSS THE AREA
EARLY NEXT WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...TRM
SHORT TERM...SL
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
206 PM EDT SAT AUG 2 2014
.SYNOPSIS...
AN UPPER LEVEL LOW CROSSES TONIGHT INTO SUNDAY. WEAK HIGH PRESSURE
PASSES EARLY NEXT WEEK. A COLD FRONT CROSSES MID WEEK. A STRONGER
HIGH THEN BUILDS IN TO CLOSE OUT THE WORK WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE HRRR SEEMS TO HAVE THE BEST HANDLE ON WHAT IS CURRENTLY GOING ON
ALTHOUGH NONE OF THE MODELS SEEM TO BE GRASPING WHAT APPEARS TO BE A
LINE OF SHOWERS AND THUNDERSTORMS JUST AHEAD OF AN UPPER LEVEL
TROUGH APPROACHING THE MIDDLE OHIO VALLEY. THAT TROUGH BECOMES A
CLOSED LOW AT TIMES AS IT MOVES ACROSS TONIGHT. IT THEN OPENS UP
AND PULLS OUT OF THE AREA ON SUNDAY.
HAVE THE ASSOCIATED CONVECTION WANING WITH THE SUNSET TONIGHT...THEN
REFIRING A BIT DURING THE HEATING OF THE DAY SUNDAY...BEFORE
TRENDING DRIER FROM THE W LATE IN THE DAY...AS THE SYSTEM BEGINS
PULLING OUT OF THE AREA. WILL HAVE TO WATCH THE SLOWER CELL
MOVEMENT AS THE FLOW IN THE COLUMN WEAKENS UNDERNEATH THE UPPER
LEVEL TROUGH AXIS.
TEMPERATURES LOOKED GOOD IN LIGHT OF THE LATEST GUIDANCE.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPPER LEVEL TROUGH MOVING ACROSS ON SUNDAY COULD PRODUCE SHOWERS AND
THUNDERSTORMS IN AREAS THAT HAVE ENOUGH MOISTURE. MODELS HAVE SOME
DIFFERENCES IN AVAILABLE MOISTURE IN THE SOUTHERN COUNTIES...BUT
AGREE ON ENOUGH MOISTURE IN THE NORTH. THEREFORE...WILL RUN WITH
HIGHER POPS IN THE NORTH.
MODELS SHOW THAT MOISTURE HAS MOVED OUT OF THE FORECAST AREA BY
MONDAY. NAM AND GFS TRY TO DEVELOP SOME LATE AFTERNOON CONVECTION IN
THE DRIER AIR...BUT MODEL SOUNDING INDICATE THAT THE ATMOSPHERE MAY
BE TOO DRY FOR THIS TO HAPPEN. THEREFORE...WILL REMOVE POPS.
TIMING OF THE MID WEEK SYSTEM VARIES BY MODEL. WITH CANADIAN AND GFS
BRINGING MOISTURE FROM THIS SYSTEM IN ON TUESDAY...WILL INCLUDE SOME
POPS ASSOCIATED WITH THIS FEATURE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
UNSETTLED WEATHER...ALONG WITH AN INCREASE IN HUMIDITY...EXPECTED
FOR THE REMAINDER OF THE EXTENDED PERIOD. A FRONTAL BOUNDARY WILL
SLOWLY SAG SOUTH WEDNESDAY INTO THE REMAINDER OF THE
EXTENDED...CREATING ADDITIONAL CHANCES FOR SHOWERS AND
THUNDERSTORMS. STILL SOME UNCERTAINTY AS TO HOW FAR SOUTH THE
BOUNDARY WILL MAKE IT/TIMING...SO HELD ONTO SLIGHT CHANCE TO CHANCE
POPS FOR REMAINDER OF EXTENDED PERIOD.
&&
.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
THUNDERSTORMS ARE LIKELY TOO INCREASE IN AREA COVERAGE IN THE HEAT
OF THE AFTERNOON...AND IN RESPONSE TO AN UPPER LEVEL TROUGH
APPROACHING FROMM THE W. THESE STORMS WILL DISSIPATE AFTER SUNSET.
DENSE VALLEY FOG IS LIKELY OVERNIGHT INTO SUNDAY MORNING. MVFR
STRATOCU MAY ALSO SHOW UP OVER EASTERN WV TONIGHT.
SUNDAY WILL BE A MAINLY VFR DAY ONCE THE FOG BURNS OFF...AS THE
UPPER LEVEL TROUGH PULLS OUT OF THE AREA...WITH ISOLATED TO
SCATTERED CONVECTION MOVING EWD.
FLOW SFC AND ALOFT WILL BE LIGHT AND VARIABLE...BECOMING LIGHT NW
ALOFT OVERNIGHT AND SUNDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING AND PLACEMENT OF CONVECTION MAY VARY
INTO THIS EVENING. TIMING AND EXTENT OF FOG MAY VARY...ALTHOUGH
CONFIDENCE IN DENSE FOG IN GENERAL IS HIGH.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M L
HTS CONSISTENCY H H H H H H H H H M M L
BKW CONSISTENCY H H H H H H H M M M H H
EKN CONSISTENCY H H H H H H H H M L L L
PKB CONSISTENCY H H H H H H H H H H M H
CKB CONSISTENCY H H H H H H H H H M M L
AFTER 18Z SUNDAY...
VLIFR IN DENSE RIVER VALLEY FOG OVERNIGHT AND EARLY MORNING AS FOG
SEASON IS UPON US...AND WEAK HIGH PRESSURE BUILDS ACROSS THE AREA
EARLY NEXT WEEK.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...TRM
SHORT TERM...RPY
LONG TERM...SL
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
754 PM EDT SUN AUG 3 2014
.SYNOPSIS...
THE UPPER LEVEL TROUGH WHICH HAS BEEN SITTING IN PLACE WILL
WEAKEN AND MOVE TO THE NORTH ON MONDAY. TEMPERATURES WILL BE
WARMING CLOSER TO AVERAGE ON MONDAY AND TUESDAY. A COLD FRONT
WILL MOVE SOUTH OF THE KEYSTONE STATE BY THURSDAY. HIGH PRESSURE
WILL BUILD ACROSS THE GREAT LAKES FOR THE LATER PART OF THE
WEEK...RESULTING IN DRIER AND COOLER WEATHER FOR THE PERIOD
THURSDAY INTO NEXT SUNDAY.
&&
.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...
THE TREND IS FOR REAL WEAKENING AND THE LAST HURRAH OF THE HEAVY
RAIN IS PUSHING EASTWARD WITH ALACRITY. LITTLE IF ANY RAIN IS LEFT
IN THE OLD FFA BOX...AND IT HAS BEEN CANCELLED. JUST SOME SHOWERS
LEFT TO MOVE THROUGH THE LOWER SUSQ...BUT EVEN THE LTG IS ALMOST
GONE FROM THAT AS WELL. THE MAIN CIRCULATION IS NOW ALONG THE NY
BORDER AND MOVING EVEN FARTHER TO THE N. EXPECT SOME SHRA TO SPIN
IN FROM THE N/W THIS EVENING...BUT HAVE MADE THE BULK OF THE NIGHT
DRY WITH AN EYE TOWARD THE HRRR WHICH SEEMS TO HAVE A GOOD HANDLE
ON THE SITUATION. HAVE MENTIONED PATCHY FOG FOR ALL OF THE AREA
SINCE THERE HAS BEEN LOTS OF RAIN AND THE SFC DEWPOINTS ARE NOT
ALL THAT LOW YET DESPITE THE VERY CLEAR/UN-HAZY AIR OUT THE
WINDOW. TYPICALLY...IF WE HAVE A DRY HOUR OR TWO BEFORE
SUNSET...THE FOG DOES NOT GET ALL THAT BAD DESPITE THE HEAVY RAIN.
SO WILL TAKE JUST A SMALL STEP WITH PATCHY WORDING FOR NOW.
&&
.SHORT TERM /7 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
DID EDGE TEMPS UP A DEGREE OR SO ON MONDAY...AS A DRIER AIRMASS
BUILDS IN FROM THE NW. MUCH LOWER PW VALUES WORK INTO THE
AREA...ESPECIALLY ACROSS THE NW. JUST A SLIGHT CHC OF A SHOWER
EXISTS IN THE NE IN THE MORNING AS THE COLD AIR ALOFT/TROUGH IS
NOT TOO FAR AWAY. SO HAVE A LITTLE 20 POP THERE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
SOME MODELS LIKE THE NAM SHOW A VORT MAX MOVING JUST TO THE SOUTH
OF THE AREA ON TUE. THUS THERE COULD BE A FEW SHOWERS AND STORMS
ACROSS THE FAR SOUTH. A COLD FRONT DROPPING SE WILL BRING A CHANCE
OF SHOWERS AND STORMS TO THE AREA LATE TUESDAY INTO WED. MADE SOME
MINOR CHANGES TO POPS. DID UP TEMPS SOME FOR TUE AND TUE NIGHT.
BEEN WORKING ON SOME OF THE LONGER TERM GRIDS EARLY ON. WENT WITH
A DRY FCST AFTER WED.
WHILE THERE COULD BE A SHOWER ACROSS THE FAR NE ON THU...THE CHC
IS LOW.
12Z GFS NOW SHOWS SOME RISK OF MOISTURE ACROSS SW PA...GIVEN A
SPLIT IN THE UPPER LVL FLOW...BUT THERE HAS BEEN A LOT OF SPREAD
IN BETWEEN MODELS AND MODEL RUNS...SO WILL KEEP FCST DRY FOR NOW.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
TROUGH PERSISTS OVER THE REGION...WITH GENERALLY VFR CONDITIONS
ACROSS CENTRAL PA TAF SITES. NUMEROUS SHOWERS WITH SCATTERED TSTMS
CONTINUE TO MOVE FROM THE WEST TO THE EAST ACROSS CENTRAL PA
EARLY THIS EVENING...THE LARGEST BEING A LINE EXTENDING FROM
REBERSBURG TO BREEZEWOOD. THIS LINE WILL CONTINUE ITS EASTWARD
TREK...BRINGING LOCAL RESTRICTIONS. THE THREAT OF THUNDER WILL
SLOWLY FADE AS THE EVENING CONTINUES...WITH CONDITIONS BECOMING VFR
ACROSS SOUTHWESTERN AIRFIELDS AS DRIER AIR WORKS BEHIND ANY
CONVECTION. ANY CLEARING OR LIFTING CIGS WILL BE FOLLOWED BY
ANOTHER DROP TO GENERALLY MVFR CONDITIONS OVERNIGHT IN FOG/LOWER
CIGS.
OUTLOOK...
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA.
THU-FRI...MAINLY VFR. PATCHY FOG POSSIBLE EARLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/MARTIN
NEAR TERM...DANGELO
SHORT TERM...ROSS/MARTIN
LONG TERM...ROSS/MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
558 PM EDT SAT AUG 2 2014
.SYNOPSIS...
THE REGION REMAINS UNDER A BROAD TROUGH OF LOW PRESSURE AND
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST FOR MOST OF
THE WEEKEND. WITH AMPLE MOISTURE IN PLACE THERE WILL BE WIDESPREAD
CLOUD COVER LIMITING THE DAYTIME HEATING...THUS HIGH TEMPERATURES
WILL CONTINUE TO RUN SEVERAL DEGREES BELOW AVERAGE BOTH TODAY AND
SUNDAY. THE TROUGH WILL WEAKEN SLOWLY AFTER THE WEEKEND WITH
TEMPERATURES WARMING CLOSER TO AVERAGE AND A GENERAL DECREASE IN
RAINFALL CHANCES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
ADDED A FLASH FLOOD WATCH UNTIL 11 PM FOR WARREN AND MCKEAN
COUNTIES.
THIS BASED ON A COMBINATION OF SLOW MOVING SHOWERS AND STORMS
ON THE RADAR...AND A COMBINATION OF LAKE BREEZE AND INVERTED
TROUGH ACROSS THE NW PART OF PA. ACTIVITY SHOULD WEAKEN BY
LATE EVENING.
EARLIER DISCUSSION BELOW.
ISOLATED SHOWERS WILL CONTINUE TO SPROUT AND IMPACT CENTRAL PA
THROUGH THIS EVENING. MOST ACTIVE CONVECTION REMAINS OVER OH
AHEAD OF THE SLOWLY ADVANCING UPPER TROF AXIS...BUT WILL SPREAD TO
FAR NORTHWEST PA ALONG THE LAKE ERIE SHORE THIS EVENING AS THE
AXIS SHIFTS EASTWARD. THIS AXIS WILL CONTINUE DRIFTING EASTWARD
TONIGHT...AND LATEST HRRR SUGGESTS THE LAUREL HIGHLANDS AND WEST
CENTRAL AND NORTHWEST MOUNTAINS MAY SEE SOME PERSISTENT LATE
NIGHT CONVECTION. UPPED POPS TO LIKELIES IN THESE AREAS AS A
RESULT. HEAVY RAIN THREAT REMAINS ISOLATED THIS EVENING...BUT
EVENING SHIFT MAY WANT TO CONSIDER FFA FOR WESTERN PORTIONS
OVERNIGHT IF THE HRRR SOLUTION GAINS GREATER FAVOR. TEMPERATURES
WILL REMAIN SEASONABLE OVERNIGHT WITH WIDESPREAD CLOUD COVER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
UPPER TROF AXIS WILL SLOWLY MOVE OVER WESTERN AND INTO CENTRAL PA
ON SUNDAY. PLENTY OF AMBIENT MOISTURE AND PERSISTENT UPPER
FORCING SHOULD SPELL AN ACTIVE SHOWERY DAY WITH LOCAL SLOW MOVING
HEAVY RAINERS...AS 850 MB WINDS REMAIN LESS THAN 5 KTS. AFTN MAXES
VERY SIMILAR TO TODAY OVERALL GIVEN VERY SIMILAR CONDITIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
SOME SHOWERS AND STORMS POSSIBLE SUNDAY NIGHT...AS THE OH
VLY SYSTEM LIFTS EAST OF THE AREA.
SOME CHANCE OF A SHOWER OR STORM MONDAY INTO TUE AM...BUT
MOST OF THE TIME SHOULD BE DRY.
DID EDGE TEMPS UP SOME DURING THE DAY MONDAY INTO WED...AND
LOWER MIN TEMPS SOME...GIVEN THAT LIGHT WINDS WILL ALLOW TEMPS
TO DROP. WITH N TO NE FLOW...FOG WILL LIKELY OCCUR IN SPOTS
EARLY.
A COLD FRONT DROPPING SE LATE TUE INTO WED WILL BRING SOME
SHOWERS AND STORMS TO THE AREA LATER TUESDAY INTO WED. DID UP
POPS ACROSS THE NW LATER TUE AFT...AND ACROSS THE AREA TUESDAY
NIGHT.
SHOULD BE MAINLY DRY AFTER WED. TREND WITH MODELS INCLUDING
THE EC IS SLIGHTLY DEEPER WITH THE UPPER LVL TROUGH. THUS
GIVEN TRACK RECORD THIS SUMMER...DID EDGE TEMPS DOWN SOME
FOR THE SECOND PART OF THE WEEK.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
BROAD TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION.
SCT SHOWERS/ISO TSTMS WILL BE COMMON ACROSS THE NORTHWESTERN
PORTION OF CENTRAL PA. EXPECT VICINITY SHOWERS AND THUNDERSTORMS
AT BFD...WITH MVFR CIGS AND VSBYS POSSIBLE THROUGH 03Z. THE
HEAVIEST SHOWERS AND THUNDERSTORMS WILL REMAIN THROUGHOUT THE
WESTERN HALF OF PENNSYLVANIA.
SHOWER ACTIVITY WILL CONTINUE THROUGH THE FIRST HALF OF THE
EVENING WITH THE ALLEGHENY HIGHLANDS AND WEST CENTRAL MOUNTAINS
SEEING WIDESPREAD SHOWER ACTIVITY AS THE UPPER TROF AXIS DRIFTS
TOWARDS OH/PA BORDER. ONCE THESE SHOWERS AND THUNDERSTORMS
CLEAR...A BUILDING INVERSION...LIGHT WINDS AND CLEARING SKIES
SHOULD ALLOW FOR RESTRICTIONS AT ALL TAF SITES. EXPECT IFR CIGS
AND VSBYS AT BFD TO JST...AND MVFR ELSEWHERE.
OUTLOOK...
SUN...AM MVFR/IFR...THEN MAINLY VFR BUT WITH SCATTERED AFTERNOON
SHRA/TSRA IMPACTS POSSIBLE.
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA. THU...MAINLY VFR. PATCHY FOG POSSIBLE
EARLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR PAZ004-005.
&&
$$
SYNOPSIS...ROSS/DEVOIR
NEAR TERM...ROSS/DANGELO/DEVOIR/MARTIN
SHORT TERM...ROSS/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
358 PM EDT SAT AUG 2 2014
.SYNOPSIS...
THE REGION REMAINS UNDER A BROAD TROUGH OF LOW PRESSURE AND
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST FOR MOST OF
THE WEEKEND. WITH AMPLE MOISTURE IN PLACE THERE WILL BE WIDESPREAD
CLOUD COVER LIMITING THE DAYTIME HEATING...THUS HIGH TEMPERATURES
WILL CONTINUE TO RUN SEVERAL DEGREES BELOW AVERAGE BOTH TODAY AND
SUNDAY. THE TROUGH WILL WEAKEN SLOWLY AFTER THE WEEKEND WITH
TEMPERATURES WARMING CLOSER TO AVERAGE AND A GENERAL DECREASE IN
RAINFALL CHANCES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
ADDED A FLASH FLOOD WATCH UNTIL 11 PM FOR WARREN AND MCKEAN
COUNTIES.
THIS BASED ON A COMBINATION OF SLOW MOVING SHOWERS AND STORMS
ON THE RADAR...AND A COMBINATION OF LAKE BREEZE AND INVERTED
TROUGH ACROSS THE NW PART OF PA. ACTIVITY SHOULD WEAKEN BY
LATE EVENING.
EARLIER DISCUSSION BELOW.
ISOLATED SHOWERS WILL CONTINUE TO SPROUT AND IMPACT CENTRAL PA
THROUGH THIS EVENING. MOST ACTIVE CONVECTIONN REMAINS OVER OH
AHEAD OF THE SLOWLY ADVANCING UPPER TROF AXIS...BUT WILL SPREAD
TO FAR NORTHWEST PA ALONG THE LAKE ERIE SHORE THIS EVENING AS THE
AXIS SHIFTS EASTWARD. THIS AXIS WILL CONTINUE DRIFTING EASTWARD
TONIGHT...AND LATEST HRRR SUGGESTS THE LAUREL HIGHLANDS AND WEST
CENTRAL AND NORTHWEST MOUNTAINS MAY SEE SOME PERSISTEN LATE NIGHT
CONVECTION. UPPED POPS TO LIKELIES IN THESE AREAS AS A RESULT.
HEAVY RAIN THREAT REMAINS ISOLATED THIS EVENING...BUT EVENING
SHIFT MAY WANT TO CONSIDER FFA FOR WESTERN PORTIONS OVERNIGHT IF
THE HRRR SOLUTION GAINS GREATER FAVOR. TEMPERATURES WILL REMAIN
SEASONABLE OVERNIGHT WITH WIDESPREAD CLOUD COVER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
UPPER TROF AXIS WILL SLOWLY MOVE OVER WESTERN AND INTO CENTRAL PA
ON SUNDAY. PLENTY OF AMBIENT MOISTUREAND PERSISTENT UPPER FORCING
SHOULD SPELL AN ACTIVE SHOWERY DAY WITH LOCAL SLOW MOVING HEAVY
RAINERS...AS 850 MB WINDS REMAIN LESS THAN 5 KTS. AFTN MAXES VERY
SIMILAR TO TODAY OVERALL GIVEN VERY SIMILAR CONDITIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
SOME SHOWERS AND STORMS POSSIBLE SUNDAY NIGHT...AS THE OH
VLY SYSTEM LIFTS EAST OF THE AREA.
SOME CHANCE OF A SHOWER OR STORM MONDAY INTO TUE AM...BUT
MOST OF THE TIME SHOULD BE DRY.
DID EDGE TEMPS UP SOME DURING THE DAY MONDAY INTO WED...AND
LOWER MIN TEMPS SOME...GIVEN THAT LIGHT WINDS WILL ALLOW TEMPS
TO DROP. WITH N TO NE FLOW...FOG WILL LIKELY OCCUR IN SPOTS
EARLY.
A COLD FRONT DROPPING SE LATE TUE INTO WED WILL BRING SOME
SHOWERS AND STORMS TO THE AREA LATER TUESDAY INTO WED. DID UP
POPS ACROSS THE NW LATER TUE AFT...AND ACROSS THE AREA TUESDAY
NIGHT.
SHOULD BE MAINLY DRY AFTER WED. TREND WITH MODELS INCLUDING
THE EC IS SLIGHTLY DEEPER WITH THE UPPER LVL TROUGH. THUS
GIVEN TRACK RECORD THIS SUMMER...DID EDGE TEMPS DOWN SOME
FOR THE SECOND PART OF THE WEEK.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
BROAD TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION.
SCT SHOWERS/ISO TSTMS WILL BE COMMON WITH AFTERNOON HEATING. VCSH
WARRANTED FOR ISOLATED TO LOW SCT COVERAGE OF CELLS. MOST FOCUSED
AREA WILL BE ACROSS THE PA/OH BORDER.
SHOWER ACTIVITY WILL CONTINUE INTO TONIGHT...WITH RESTRICTIONS IN
THICKER FOG EXPECTED. ALLEGHENY HIGHLANDS AND WEST CENTRAL
MOUNTAINS MAY SEE MOST WIDESPREAD SHOWER ACTIVITY LATER TONIGHT AS
UPPER TROF AXIS DRIFTS TOWARDS OH/PA BORDER.
OUTLOOK...
SUN...AM MVFR/IFR...THEN MAINLY VFR BUT WITH SCATTERED AFTERNOON
SHRA/TSRA IMPACTS POSSIBLE.
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA.
THU...MAINLY VFR. PATCHY FOG POSSIBLE EARLY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR PAZ004-005.
&&
$$
SYNOPSIS...ROSS/DEVOIR
NEAR TERM...ROSS/DANGELO/DEVOIR/MARTIN
SHORT TERM...ROSS/DEVOIR
LONG TERM...MARTIN
AVIATION...DEVOIR/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
250 PM EDT SAT AUG 2 2014
.SYNOPSIS...
THE REGION REMAINS UNDER A BROAD TROUGH OF LOW PRESSURE AND SHOWERS
AND THUNDERSTORMS WILL REMAIN IN THE FORECAST FOR MOST OF THE
WEEKEND. WITH AMPLE MOISTURE IN PLACE THERE WILL BE WIDESPREAD
CLOUD COVER LIMITING THE DAYTIME HEATING...THUS HIGH TEMPERATURES
WILL CONTINUE TO RUN SEVERAL DEGREES BELOW AVERAGE BOTH TODAY AND
SUNDAY. THE TROUGH WILL WEAKEN SLOWLY AFTER THE WEEKEND WITH
TEMPERATURES WARMING CLOSER TO AVERAGE AND A GENERAL DECREASE IN
RAINFALL CHANCES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
ISOLATED SHOWERS WILL CONTINUE TO SPROUT AND IMPACT CENTRAL PA
THROUGH THIS EVENING. MOST ACTIVE CONVECTIONN REMAINS OVER OH AHEAD
OF THE SLOWLY ADVANCING UPPER TROF AXIS...BUT WILL SPREAD TO FAR
NORTHWEST PA ALONG THE LAKE ERIE SHORE THIS EVENING AS THE AXIS
SHIFTS EASTWARD. THIS AXIS WILL CONTINUE DRIFTING EASTWARD
TONIGHT...AND LATEST HRRR SUGGESTS THE LAUREL HIGHLANDS AND WEST
CENTRAL AND NORTHWEST MOUNTAINS MAY SEE SOME PERSISTEN LATE NIGHT
CONVECTION. UPPED POPS TO LIKELIES IN THESE AREAS AS A RESULT.
HEAVY RAIN THREAT REMAINS ISOLATED THIS EVENING...BUT EVENING
SHIFT MAY WANT TO CONSIDER FFA FOR WESTERN PORTIONS OVERNIGHT IF
THE HRRR SOLUTION GAINS GREATER FAVOR. TEMPERATURES WILL REMAIN
SEASONABLE OVERNIGHT WITH WIDESPREAD CLOUD COVER.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
UPPER TROF AXIS WILL SLOWLY MOVE OVER WESTERN AND INTO CENTRAL PA
ON SUNDAY. PLENTY OF AMBIENT MOISTUREAND PERSISTENT UPPER FORCING
SHOULD SPELL AN ACTIVE SHOWERY DAY WITH LOCAL SLOW MOVING HEAVY
RAINERS...AS 850 MB WINDS REMAIN LESS THAN 5 KTS. AFTN MAXES VERY
SIMILAR TO TODAY OVERALL GIVEN VERY SIMILAR CONDITIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
TROUGH AXIS SLIDES THROUGH THE CWA SUN NIGHT WITH A DRIER
WESTERLY FLOW ON MONDAY. WITH THE DRIER CONDITIONS AND MORE
SUNSHINE TEMPERATURES WILL WARM CLOSER TO SEASONAL NORMS. STILL
CANNOT RULE OUT A SHOWER OR THUNDERSTORM AS THERE WILL LIKELY BE
SOME UPPER LEVEL DISTURBANCES IN THE FLOW. THE MID AND UPPER FLOW
VEERS AROUND TO THE WEST TUESDAY AHEAD OF SIGNIFICANT UPPER WAVE
/AND POTENT SFC CFRONT/ DROPPING SE ACROSS THE GLAKES. A SECONDARY
CFRONT WILL MOVE SE THROUGH THE AREA DURING THE DAY WEDNESDAY.
PWATS WILL BE DROPPING BACK TO NEAR OR SLIGHTLY BELOW NORMAL /EVEN
AHEAD OF THE 2 CFRONTS/. HOWEVER...850-500 MB LAPSE RATES AHEAD OF
BOTH FEATURES WILL BE AS MUCH AS 6.5C/KM...WHICH WILL LEAD TO
SCATTERED...MAINLY AFTERNOON AND EARLY EVENING TSRA. A FEW OF THE
TSRA EACH AFTERNOON COULD BE ON THE STRONG SIDE. 0-3KM BULK SHEAR
WILL BE AOB 15 KTS...SO THE CFROPAS BOTH DAYS DON/T APPEAR TO POSE
A SIGNIFICANT...CONVECTIVE WIND THREAT ATTM.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
BROAD TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION.
SCT SHOWERS/ISO TSTMS WILL BE COMMON WITH AFTERNOON HEATING. VCSH
WARRANTED FOR ISOLATED TO LOW SCT COVERAGE OF CELLS. MOST FOCUSED
AREA WILL BE ACROSS THE PA/OH BORDER.
SHOWER ACTIVITY WILL CONTINUE INTO TONIGHT...WITH RESTRICTIONS IN
THICKER FOG EXPECTED. ALLEGHENY HIGHLANDS AND WEST CENTRAL
MOUNTAINS MAY SEE MOST WIDESPREAD SHOWER ACTIVITY LATER TONIGHT AS
UPPER TROF AXIS DRIFTS TOWARDS OH/PA BORDER.
OUTLOOK...
SUN...AM MVFR/IFR...THEN MAINLY VFR BUT WITH SCATTERED AFTERNOON
SHRA/TSRA IMPACTS POSSIBLE.
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS/DEVOIR
NEAR TERM...ROSS/DEVOIR
SHORT TERM...ROSS/DEVOIR
LONG TERM...ROSS
AVIATION...DEVOIR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1210 PM EDT SAT AUG 2 2014
.SYNOPSIS...
THE REGION REMAINS UNDER A BROAD TROUGH OF LOW PRESSURE AND SHOWERS
AND THUNDERSTORMS WILL REMAIN IN THE FORECAST FOR MOST OF THE
WEEKEND. WITH AMPLE MOISTURE IN PLACE THERE WILL BE WIDESPREAD
CLOUD COVER LIMITING THE DAYTIME HEATING...THUS HIGH TEMPERATURES
WILL CONTINUE TO RUN SEVERAL DEGREES BELOW AVERAGE BOTH TODAY AND
SUNDAY. THE TROUGH WILL WEAKEN SLOWLY AFTER THE WEEKEND WITH
TEMPERATURES WARMING CLOSER TO AVERAGE AND A GENERAL DECREASE IN
RAINFALL CHANCES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ISOLATED SHOWERS JUST BEGININNG TO SPROUT ACROSS CENTRAL PA...
SEVERAL OVER EASTERN CENTRE COUNTY AT THIS HOUR. REGIONALLY...
THE MOST ACTIVE CONVECTIONN REMAINS OVER AHEAD OF THE SLOWLY
ADVANCING UPPER TROF AXIS. THIS AXIS WILL CONTINUE DRIFTING
EASTWARD THROUGHOUT THE AFTERNOON...AND BE LOCATED OVER CENTRAL
OHIO BY 00Z SUN.
STEEPENING LAPSE RATES AND SLOWLY INCREASING MOISTURE WILL
CONTINUE TO AID THE DEVELOPMENT OF SCATTERED SCATTERED CONVECTION
ACROSS CENTRAL PA THIS AFTERNOON. MODERATE MOISTURE FLUX AND
UPPER FORCING FROM 2 SHORTWAVE TROFS ROTATING NORTHEASTWARD
THROUGH SOUTHEAST OH AND WESTERN PA WILL FOCUS THE DEEPEST
CONVECTION OVER WESTERN PA THIS AFTERNOON...WITH 00Z 4KM SPC WRF
AND LATEST HRRR CONSOLIDATING THIS ACTIVITY ALONG OR JUST WEST OF
THE ALLEGHENY CREST IN WEST CENTRAL AND NORTHWEST PA.
FAIRLY HOMOGENEOUS DEEP LAYER MOISTURE FROM 1.4" TO 1.6" WILL
PROMOTE SOME DECENT DOWNPOURS...AND WITH BOUNDARY LAYER FLOW
NEGLIGIBLE...WE MAY SEE SOME ISOLATED HEAVY AMOUNTS SIMILAR TO
FRIDAY AFTERNOON ACROSS PORTIONS OF THE LOWER SUSQ RIVER VALLEY
(RADAR ESTIMATES EXCEEDED 3 INCHES AROUND PINE GROVE FURNACE IN
SOUTHERN CUMBERLAND COUNTY...AND OVER 2.5 INCHES NORTH OF
LINGLESTOWN IN DAUPHIN COUNTY). HEAVY RAIN THREAT REMAINS
ISOLATED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TROF AXIS SLOWLY MOVES CLOSER TO PA AND REGION WILL CONTINUE TO
HAVE A CHANCE FOR SHOWERS AND THUNDERSTORMS OVERNIGHT TONIGHT AND
AGAIN ON SUNDAY. TEMPERATURES MILD TONIGHT WITH LOW LEVEL CLOUDS
LIMITING AND RADIATIONAL COOLING. TEMPERATURES SUNDAY AGAIN
TEMPERED BY CLOUD COVER AND RAINFALL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
TROUGH AXIS SLIDES THROUGH THE CWA SUN NIGHT WITH A DRIER
WESTERLY FLOW ON MONDAY. WITH THE DRIER CONDITIONS AND MORE
SUNSHINE TEMPERATURES WILL WARM CLOSER TO SEASONAL NORMS. STILL
CANNOT RULE OUT A SHOWER OR THUNDERSTORM AS THERE WILL LIKELY BE
SOME UPPER LEVEL DISTURBANCES IN THE FLOW. THE MID AND UPPER FLOW
VEERS AROUND TO THE WEST TUESDAY AHEAD OF SIGNIFICANT UPPER WAVE
/AND POTENT SFC CFRONT/ DROPPING SE ACROSS THE GLAKES. A SECONDARY
CFRONT WILL MOVE SE THROUGH THE AREA DURING THE DAY WEDNESDAY.
PWATS WILL BE DROPPING BACK TO NEAR OR SLIGHTLY BELOW NORMAL /EVEN
AHEAD OF THE 2 CFRONTS/. HOWEVER...850-500 MB LAPSE RATES AHEAD OF
BOTH FEATURES WILL BE AS MUCH AS 6.5C/KM...WHICH WILL LEAD TO
SCATTERED...MAINLY AFTERNOON AND EARLY EVENING TSRA. A FEW OF THE
TSRA EACH AFTERNOON COULD BE ON THE STRONG SIDE. 0-3KM BULK SHEAR
WILL BE AOB 15 KTS...SO THE CFROPAS BOTH DAYS DON/T APPEAR TO POSE
A SIGNIFICANT...CONVECTIVE WIND THREAT ATTM.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
BROAD TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION.
QUIET RADAR SCOPE AT 12Z...WITH GENERALLY MVFR VSBYS IN MOST
LOCATIONS EARLY THIS MORNING...ALONG WITH SOME MVFR CIGS
THAT HAD DEVELOPED OVER PORTIONS OF THE EAST FROM KUNV-KIPT.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR BY 14-15Z.
REMAINDER OF THE DAY WILL SEE DEVELOPMENT OF SCT SHOWERS/ISO TSTMS
WITH AFTERNOON HEATING AS A 4000FT DECK DEVELOPS. HRRR INDICATES
SHOWERS MAY FIRST INITIATE AROUND KIPT...BUT AS DAY WEARS ON
ACTIVITY WILL SHIFT TOWARD THE WESTERN AND NORTHERN MTNS. WITH HIT
AND MISS VARIETY CONVECTION...HELD ON TO VCSH AFTER 18Z IN MOST
TERMINALS...WITH UPDATES PLANNED TO THE FORECAST IF RESTRICTIONS
BECOME MORE IMMINENT AT TERMINALS.
SHOWER ACTIVITY MAY CONTINUE INTO TONIGHT...WITH RESTRICTIONS IN
THICKER FOG EXPECTED TO BE MORE WIDESPREAD THAN THIS MORNING.
OUTLOOK...
SUN...AM MVFR/IFR...THEN MAINLY VFR BUT WITH SCATTERED AFTERNOON
SHRA/TSRA IMPACTS POSSIBLE.
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS/DEVOIR
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
928 AM EDT SAT AUG 2 2014
.SYNOPSIS...
THE REGION REMAINS UNDER A BROAD TROUGH OF LOW PRESSURE AND SHOWERS
AND THUNDERSTORMS WILL REMAIN IN THE FORECAST FOR MOST OF THE
WEEKEND. WITH AMPLE MOISTURE IN PLACE THERE WILL BE WIDESPREAD
CLOUD COVER LIMITING THE DAYTIME HEATING...THUS HIGH TEMPERATURES
WILL CONTINUE TO RUN SEVERAL DEGREES BELOW AVERAGE BOTH TODAY AND
SUNDAY. THE TROUGH WILL WEAKEN SLOWLY AFTER THE WEEKEND WITH
TEMPERATURES WARMING CLOSER TO AVERAGE AND A GENERAL DECREASE IN
RAINFALL CHANCES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ACTIVE CONVECTION FOR THIS TIME OF DAY TO OUR WEST OVER MOST OF
OHIO AHEAD OF THE UPPER TROF AXIS WHICH IS ALIGNED FROM LAKE
HURON SOUTHWARD TO NORTH CENTRAL KY THIS MORNING. THE 5H TROF AXIS
WILL SLOWLY DRIFT EASTWARD THROUGHOUT THE AFTERNOON...AND BE
LOCATED OVER CENTRAL OHIO BY 00Z SUN.
MODERATE MOISTURE FLUX AND UPPER FORCING FROM 2 SHORTWAVE TROFS
ROTATING NORTHEASTWARD THROUGH SOUTHEAST OH AND WESTERN PA WILL
INCREASE CONVECTION OVER WESTERN PA THIS AFTERNOON...WITH 00Z 4KM
SPC WRF AND LATEST HRRR CONSOLIDATING THIS ACTIVITY ALONG OR JUST
WEST OF THE ALLEGHENY CREST IN WEST CENTRAL AND NORTHWEST PA.
FARTHER EAST ACROSS THE REST OF CENTRAL PA...MOISTURE WILL ALSO
INCREASE WITH SCATTERED CONVECTION EXPECTED. FAIRLY HOMOGENEOUS
DEEP LAYER MOISTURE FROM 1.4" TO 1.6" WILL PROMOTE SOME DECENT
DOWNPOURS...AND WITH BOUNDARY LAYER FLOW NEGLIGIBLE...WE MAY SEE
SOME ISOLATED HEAVY AMOUNTS SIMILAR TO FRIDAY AFTERNOON ACROSS
PORTIONS OF THE LOWER SUSQ RIVER VALLEY (RADAR ESTIMATES EXCEEDED
3 INCHES AROUND PINE GROVE FURNACE IN SOUTHERN CUMBERLAND
COUNTY...AND OVER 2.5 INCHES NORTH OF LINGLESTOWN IN DAUPHIN
COUNTY). HEAVY RAIN THREAT IS ISOLATED...HOWEVER...SO NO WATCHES
BEING CONSIDERED AT THIS TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TROF AXIS SLOWLY MOVES CLOSER TO PA AND REGION WILL CONTINUE TO
HAVE A CHANCE FOR SHOWERS AND THUNDERSTORMS OVERNIGHT TONIGHT AND
AGAIN ON SUNDAY. TEMPERATURES MILD TONIGHT WITH LOW LEVEL CLOUDS
LIMITING AND RADIATIONAL COOLING. TEMPERATURES SUNDAY AGAIN
TEMPERED BY CLOUD COVER AND RAINFALL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
TROUGH AXIS SLIDES THROUGH THE CWA SUN NIGHT WITH A DRIER
WESTERLY FLOW ON MONDAY. WITH THE DRIER CONDITIONS AND MORE
SUNSHINE TEMPERATURES WILL WARM CLOSER TO SEASONAL NORMS. STILL
CANNOT RULE OUT A SHOWER OR THUNDERSTORM AS THERE WILL LIKELY BE
SOME UPPER LEVEL DISTURBANCES IN THE FLOW. THE MID AND UPPER FLOW
VEERS AROUND TO THE WEST TUESDAY AHEAD OF SIGNIFICANT UPPER WAVE
/AND POTENT SFC CFRONT/ DROPPING SE ACROSS THE GLAKES. A SECONDARY
CFRONT WILL MOVE SE THROUGH THE AREA DURING THE DAY WEDNESDAY.
PWATS WILL BE DROPPING BACK TO NEAR OR SLIGHTLY BELOW NORMAL /EVEN
AHEAD OF THE 2 CFRONTS/. HOWEVER...850-500 MB LAPSE RATES AHEAD OF
BOTH FEATURES WILL BE AS MUCH AS 6.5C/KM...WHICH WILL LEAD TO
SCATTERED...MAINLY AFTERNOON AND EARLY EVENING TSRA. A FEW OF THE
TSRA EACH AFTERNOON COULD BE ON THE STRONG SIDE. 0-3KM BULK SHEAR
WILL BE AOB 15 KTS...SO THE CFROPAS BOTH DAYS DON/T APPEAR TO POSE
A SIGNIFICANT...CONVECTIVE WIND THREAT ATTM.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
BROAD TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION.
QUIET RADAR SCOPE AT 12Z...WITH GENERALLY MVFR VSBYS IN MOST
LOCATIONS EARLY THIS MORNING...ALONG WITH SOME MVFR CIGS
THAT HAD DEVELOPED OVER PORTIONS OF THE EAST FROM KUNV-KIPT.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR BY 14-15Z.
REMAINDER OF THE DAY WILL SEE DEVELOPMENT OF SCT SHOWERS/ISO TSTMS
WITH AFTERNOON HEATING AS A 4000FT DECK DEVELOPS. HRRR INDICATES
SHOWERS MAY FIRST INITIATE AROUND KIPT...BUT AS DAY WEARS ON
ACTIVITY WILL SHIFT TOWARD THE WESTERN AND NORTHERN MTNS. WITH HIT
AND MISS VARIETY CONVECTION...HELD ON TO VCSH AFTER 18Z IN MOST
TERMINALS...WITH UPDATES PLANNED TO THE FORECAST IF RESTRICTIONS
BECOME MORE IMMINENT AT TERMINALS.
SHOWER ACTIVITY MAY CONTINUE INTO TONIGHT...WITH RESTRICTIONS IN
THICKER FOG EXPECTED TO BE MORE WIDESPREAD THAN THIS MORNING.
OUTLOOK...
SUN...AM MVFR/IFR...THEN MAINLY VFR BUT WITH SCATTERED AFTERNOON
SHRA/TSRA IMPACTS POSSIBLE.
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS/DEVOIR
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
806 AM EDT SAT AUG 2 2014
.SYNOPSIS...
THE REGION REMAINS UNDER A BROAD TROUGH OF LOW PRESSURE AND SHOWERS
AND THUNDERSTORMS WILL REMAIN IN THE FORECAST FOR MOST OF THE
WEEKEND. WITH AMPLE MOISTURE IN PLACE THERE WILL BE WIDESPREAD
CLOUD COVER LIMITING THE DAYTIME HEATING...THUS HIGH TEMPERATURES
WILL CONTINUE TO RUN SEVERAL DEGREES BELOW AVERAGE BOTH TODAY AND
SUNDAY. THE TROUGH WILL WEAKEN SLOWLY AFTER THE WEEKEND WITH
TEMPERATURES WARMING CLOSER TO AVERAGE AND A GENERAL DECREASE IN
RAINFALL CHANCES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DECREASED POPS FOR SE ZONES AS RADAR SHOWS HEAVIEST BAND OF RAIN
WILL MISS THE REGION. STILL CANNOT RULE OUT A FEW SHOWERS ACROSS
THIS AREA...BUT MOST OF THE CWA WILL BE DRY THIS MORNING. TROUGH
AXIS STILL W OF CWA AND REGION IN SW FLOW OF MOIST AIR. AS HAS
BEEN THE CASE MUCH OF THE WEEK...LOOK FOR CONVECTION TO INCREASE
THIS AFTERNOON WITH THE DAYTIME HEATING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TROF AXIS SLOWLY MOVES CLOSER TO PA AND REGION WILL CONTINUE TO
HAVE A CHANCE FOR SHOWERS AND THUNDERSTORMS OVERNIGHT TONIGHT AND
AGAIN ON SUNDAY. TEMPERATURES MILD TONIGHT WITH LOW LEVEL CLOUDS
LIMITING AND RADIATIONAL COOLING. TEMPERATURES SUNDAY AGAIN
TEMPERED BY CLOUD COVER AND RAINFALL.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
TROUGH AXIS SLIDES THROUGH THE CWA SUN NIGHT WITH A DRIER
WESTERLY FLOW ON MONDAY. WITH THE DRIER CONDITIONS AND MORE
SUNSHINE TEMPERATURES WILL WARM CLOSER TO SEASONAL NORMS. STILL
CANNOT RULE OUT A SHOWER OR THUNDERSTORM AS THERE WILL LIKELY BE
SOME UPPER LEVEL DISTURBANCES IN THE FLOW. THE MID AND UPPER FLOW
VEERS AROUND TO THE WEST TUESDAY AHEAD OF SIGNIFICANT UPPER WAVE
/AND POTENT SFC CFRONT/ DROPPING SE ACROSS THE GLAKES. A SECONDARY
CFRONT WILL MOVE SE THROUGH THE AREA DURING THE DAY WEDNESDAY.
PWATS WILL BE DROPPING BACK TO NEAR OR SLIGHTLY BELOW NORMAL /EVEN
AHEAD OF THE 2 CFRONTS/. HOWEVER...850-500 MB LAPSE RATES AHEAD OF
BOTH FEATURES WILL BE AS MUCH AS 6.5C/KM...WHICH WILL LEAD TO
SCATTERED...MAINLY AFTERNOON AND EARLY EVENING TSRA. A FEW OF THE
TSRA EACH AFTERNOON COULD BE ON THE STRONG SIDE. 0-3KM BULK SHEAR
WILL BE AOB 15 KTS...SO THE CFROPAS BOTH DAYS DON/T APPEAR TO POSE
A SIGNIFICANT...CONVECTIVE WIND THREAT ATTM.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
BROAD TROUGH OF LOW PRESSURE CONTINUES TO LINGER OVER THE REGION.
QUIET RADAR SCOPE AT 12Z...WITH GENERALLY MVFR VSBYS IN MOST
LOCATIONS EARLY THIS MORNING...ALONG WITH SOME MVFR CIGS
THAT HAD DEVELOPED OVER PORTIONS OF THE EAST FROM KUNV-KIPT.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR BY 14-15Z.
REMAINDER OF THE DAY WILL SEE DEVELOPMENT OF SCT SHOWERS/ISO TSTMS
WITH AFTERNOON HEATING AS A 4000FT DECK DEVELOPS. HRRR INDICATES
SHOWERS MAY FIRST INITIATE AROUND KIPT...BUT AS DAY WEARS ON
ACTIVITY WILL SHIFT TOWARD THE WESTERN AND NORTHERN MTNS. WITH HIT
AND MISS VARIETY CONVECTION...HELD ON TO VCSH AFTER 18Z IN MOST
TERMINALS...WITH UPDATES PLANNED TO THE FORECAST IF RESTRICTIONS
BECOME MORE IMMINENT AT TERMINALS.
SHOWER ACTIVITY MAY CONTINUE INTO TONIGHT...WITH RESTRICTIONS IN
THICKER FOG EXPECTED TO BE MORE WIDESPREAD THAN THIS MORNING.
OUTLOOK...
SUN...AM MVFR/IFR...THEN MAINLY VFR BUT WITH SCATTERED AFTERNOON
SHRA/TSRA IMPACTS POSSIBLE.
MON...POSSIBLE AM FOG AREAS MVFR/IFR. OTHERWISE MAINLY VFR.
TUE...SCATTERED SHRA/TSRA WITH APPROACHING COLD FRONT.
WED...SCATTERED SHRA/TSRA.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...ROSS
NEAR TERM...ROSS
SHORT TERM...ROSS
LONG TERM...ROSS
AVIATION...RXR
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1025 AM EDT SAT AUG 2 2014
.DISCUSSION...
FORECAST LOOKS GENERALLY ON TRACK SO FAR THIS MORNING. THE 12Z OHX
SOUNDING SHOWS SOME LOW LEVEL MOISTURE...BUT DRY AIR ABOVE 650 MB.
LATEST HRRR AND RAP SHOW CONVECTION DEVELOPING THIS AFTERNOON AS
THE UPPER TROUGH AXIS MOVES CLOSER...BUT COVERAGE SHOULD REMAIN
SCATTERED WITH THE LIMITED MOISTURE ALOFT AND WEAK LIFT.
TEMPERATURES MAY NEED A NUDGE DOWNWARD BASED ON CURRENT OBS...CLOUD
COVER...AND LATEST LAMP GUIDANCE.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
640 PM CDT SUN AUG 3 2014
.AVIATION...
/00Z TAFS/
NO MAJOR CHALLENGES WITH CURRENT TAF FORECAST ARE EXPECTED. NE
WINDS 10-15 KTS AND VFR CONDITIONS ARE ONGOING WITH ISOLATED
SHOWERS REMAINING EAST OF THE AIRPORTS. THESE SHOWERS WILL
DISSIPATE AFTER SUNSET AND NOT AFFECT THE AIRPORTS. LIGHT EAST
WIND WITH WITH MOST CU DISSIPATING IS EXPECTED BY MID EVENING.
THE ONLY MINOR CONCERN IS A POSSIBILITY OF MVFR AT WACO FOR AN
HOUR OR TWO AFTER SUNRISE MONDAY MORNING. A 925-850MB LOW OVER
EXTREME SE TX CONTINUES TO DRIFT WSW OVERNIGHT AND MAY BRING SOME
RICHER 925MB MOISTURE CLOSE TO WACO. RIGHT NOW NEITHER MODEL BUFR
SOUNDINGS...OR RUC OPS/BAK40 SOUNDINGS INDICATE STRONGLY THAT MVFR
CIGS WILL OCCUR AND WILL FORGO ANY MENTION AT WACO. GFS/LAMP HAVE
WINDS MIXING BACK NE AROUND 10 KTS MONDAY AFTERNOON...WHILE NAM
ADVERTISES AN ESE DIRECTION BY 21Z. HAVE DECIDED TO HOLD OFF ANY
ESE FLOW AT DFW AIRPORT UNTIL AFTER 00Z TUESDAY DUE TO THESE
UNCERTAINTIES.
05/
&&
.PREV DISCUSSION... /ISSUED 248 PM CDT SUN AUG 3 2014/
A SURFACE LOW WILL CONTINUE TO SPIN JUST OFF THE UPPER TEXAS COAST
LATE THIS AFTERNOON AND SUPPLY ABUNDANT LOW LEVEL MOISTURE TO THE
REGION. THE COMBINATION OF SURFACE HEATING...MOISTURE AND SOME
MODEST INSTABILITY WILL RESULT IN ISOLATED SHOWERS AND
THUNDERSTORMS THROUGH SUNSET...MAINLY ACROSS THE SOUTHEAST ZONES.
AFTER SUNSET...CLOUDS WILL BE ON THE DECREASE. TEMPERATURES TONIGHT
WILL BE A BIT WARMER THAN LAST NIGHT WITH LOWS FROM THE UPPER 60S
TO THE MIDDLE 70S.
THE SURFACE LOW WILL SLIDE SOUTHWEST DOWN THE TEXAS COAST ON
MONDAY. THIS WILL TURN THE WIND MORE EASTERLY AND KEEP THE BEST
MOISTURE ACROSS THE SOUTHERN ZONES. THEREFORE...WE WILL INTRODUCE
SOME LOW POPS MONDAY AFTERNOON GENERALLY SOUTH OF A LINE FROM
COMANCHE TO HILLSBORO TO ATHENS. AGAIN...ANY STORMS THAT FORM ON
MONDAY WILL BE DRIVEN BY DAYTIME HEATING AND WILL DISSIPATE BY SUNSET.
THE UPPER PATTERN THROUGH THE WEEK WILL BE LARGELY DOMINATED BY
UPPER LEVEL HIGH PRESSURE. HOWEVER...THE RIDGE AXIS WILL REMAIN WEST OF
NORTH TEXAS UNTIL THE END OF THE WEEK WHICH WILL ALLOW A FEW WEAK
WAVES TO MOVE THROUGH NORTHWEST FLOW ALOFT. ANY WEAK DISTURBANCE
COULD SPARK A FEW SHOWERS OR STORMS SO WILL KEEP 10 POPS IN THE
EAST MOST AFTERNOONS. THE ECMWF IS STILL INDICATING A SLIGHTLY
STRONGER WAVE ON THURSDAY AFTERNOON...SO WE WILL KEEP THE 20 POPS
THAT WERE IN THE PREVIOUS FORECAST.
THE UPPER RIDGE WILL MOVE A BIT FARTHER EAST INTO NORTH TEXAS NEXT
WEEKEND WHICH SHOULD LIMIT PRECIPITATION AND KEEP TEMPERATURES
SEASONABLY HOT.
THE EXTENDED MODELS CONTINUE TO ADVERTISE A PATTERN SHIFT AS WE
HEAD INTO MID AUGUST WITH THE RIDGE BUILDING ACROSS THE WESTERN
U.S. AND A TROUGH DOMINATING THE EAST. IF THIS MATERIALIZES...IT
WILL BRING COOLER TEMPERATURES AND MORE OPPORTUNITIES FOR RAIN.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 73 95 75 97 77 / 5 10 10 0 5
WACO, TX 71 94 72 95 75 / 10 20 20 5 5
PARIS, TX 67 94 68 93 72 / 10 10 10 0 5
DENTON, TX 67 95 69 98 74 / 5 10 10 0 5
MCKINNEY, TX 66 93 70 94 71 / 5 10 10 0 5
DALLAS, TX 74 94 75 95 78 / 5 10 10 5 5
TERRELL, TX 70 94 71 95 74 / 10 10 10 5 5
CORSICANA, TX 71 94 72 96 74 / 10 10 10 5 5
TEMPLE, TX 70 91 71 93 73 / 10 20 20 5 5
MINERAL WELLS, TX 67 95 69 95 71 / 5 10 10 0 5
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/79
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1244 PM CDT SAT AUG 2 2014
.DISCUSSION...SEE 18Z AVIATION DISCUSSION.
&&
.MARINE...HAVE INITIAL MVFR CIGS AT KCRP WITH KCRP MTR AND KNGP
MTR SHOWING MVFR CONDITIONS (NO THUNDER EXPECTED IN THESE TWO
TERMINALS). THESE SHOULD BE DONE BY 21Z. LIGHT RAIN SHOULD END BY
20Z AT KALI. AFTER THAT...COULD BE SOME THUNDER AT KLRD LATE THIS
AFTERNOON THROUGH LATE EVENING...BUT CONFIDENCE IS NOT THAT HIGH
(ALTHOUGH MOS POPS ARE IN CHANCE CATEGORY). FOR NOW...WILL GO WITH
A VCTS AS ANY STORMS WHICH MOVE TOWARD/ALONG RIO GRANDE FROM OLD
MEXICO/RIO GRANDE PLAINS SHOULD WEAKEN AND END (FEEL INFLOW
INSUFFICIENT TO BRING CONVECTION INTO TERMINAL AT THIS TIME ONCE
DAYTIME HEATING IS LOST). OTHER THAN THAT...AM NOT EXPECTING ANY
PROBLEMS AT KLRD AND KVCTWITH VFR CONDITIONS. HOWEVER...AT KCRP
AND KALI LIGHT NORTHERLY WINDS AND HIGH DEW POINTS COULD
CONTRIBUTE TO THE FORMATION OF FOG...ESPECIALLY AT KALI WHERE THEY
HAD BETTER RAINS. AM GOING WITH MVFR BR/TEMPO IFR BR AT KCRP AND
IFR BR/TEMPO LIFR FG AT KALI BEFORE 14Z. LIGHT NORTHERLY WINDS
(YES...NORTHERLY IN EARLY AUGUST) AFTER SUNRISE ALL TERMINALS.
&&
.PREV DISCUSSION... /ISSUED 1025 AM CDT SAT AUG 2 2014/
DISCUSSION...CONVECTION EARLIER THIS MORNING STARTING TO MOVE OUT
OF THE AREA. WILL SEE (AND ALREADY ARE SEEING) SOME CLEARING OVER
THE NORTHEASTERN AREAS. LAPS DATA CONTINUES TO SHOW A MORE STABLE
AIRMASS MOVING SOUTHWARD FARTHER INTO THE CWFA. STILL SOME
MOISTURE AVAILABLE THIS AFTERNOON AND WITH DAYTIME HEATING...COULD
SEE SOME ADDITIONAL CONVECTION. HOWEVER...THINK ACTIVITY WILL BE
MORE ISOLATED IN NATURE...WITH THE BETTER CHANCES OF RAIN THIS
AFTERNOON NEAR THE RIO GRANDE (ALTHOUGH UPSLOPE FLOW IS WEAK).
THUS...LOWERED RAIN CHANCES THIS AFTERNOON MOST AREAS AND ONLY
WENT WITH A SLIGHT CHANCE THIS EVENING. CURRENT HRRR DATA SHOWS NO
ADDITIONAL CONVECTION THIS AFTERNOON...AND THIS KIND OF LINES UP
WITH CURRENT TRENDS. UPDATES SENT...UPDATED MOST GRID PARAMETERS
THROUGH 06Z. FOR NOW...WILL LEAVE REMAINDER OF FORECAST AS-
IS...SINCE WOULD LIKE TO LOOK AT MORE NEW DATA SINCE SUBTLE
CHANGES IN MOISTURE AND/OR POSITION OF BOUNDARY COULD HAVE A BIG
EFFECT ON RAIN CHANCES AFTER MIDNIGHT TONIGHT THROUGH SUNDAY.
MARINE...KEPT SCATTERED CONVECTION OVER THE OFFSHORE WATERS
(HIGHER CAPES/LITTLE TO NO CIN)...BUT ADJUTED THEM DOWN-WARD FOR
THE BAYS/NEARSHORE. NOT MUCH IN WIND OUTSIDE OF CONVECTION.
PREV DISCUSSION... /ISSUED 809 AM CDT SAT AUG 2 2014/
DISCUSSION...QUICK UPDATE TO INCREASE POPS FARTHER SOUTH AND
INCREASE QPF. UPDATES ARE SENT.
PREV DISCUSSION... /ISSUED 634 AM CDT SAT AUG 2 2014/
DISCUSSION...UPDATED FOR THE 12Z AVIATION DISCUSSION.
AVIATION...CONVECTION ACROSS SOUTH TEXAS EXPECTED TO AFFECT AREAS
FROM CRP-ALI EARLY THIS MORNING...WITH DEVELOPMENT EXPECTED TO
REACH LRD DURING THE LATE MORNING. VCT MAY CONTINUE TO SEE ISOLATED
SHOWERS THROUGH MID MORNING BUT WITH DRIER AIR MOVING IN FROM THE
NORTH...SHOULD GENERALLY SEE A DECREASE IN ACTIVITY AT VCT WITH
VFR THROUGH THE TAF PERIOD. FOR THE REMAINING THREE
SITES...MVFR/VFR CIGS THIS MORNING SHOULD LIFT TO PREDOMINANTLY
VFR AS THE DAY PROGRESSES. HOWEVER MVFR CONDITIONS WILL BE
POSSIBLE IN AND AROUND ANY THUNDERSTORMS THROUGH THE AFTERNOON
WITH WIND GUSTS UP TO 25KTS POSSIBLE. OTHERWISE WINDS WILL
GENERALLY BE LIGHT OUT OF THE EAST-NORTHEAST. MAY SEE ISOLATED
SHOWERS ONCE MORE LATE IN THE TAF PERIOD FOR THE COASTAL SITES BUT
DUE TO ISOLATED DEVELOPMENT IN NATURE...WILL NOT MENTION IN TAFS.
PREV DISCUSSION... /ISSUED 423 AM CDT SAT AUG 2 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...LAPS DATA CURRENTLY HAS THE
WEAK FRONT DRAPED ACROSS THE CWA FROM COTULLA TO BEEVILLE TO PORT
LAVACA. MOISTURE REMAINS ABUNDANT WITH NEAR 2.3 INCHES ACROSS MUCH
OF THE AREA. WITH THE FRONT CLOSER IN PROXIMITY...MOISTURE DEPTH
HAS INCREASED AS WELL. THEREFORE...WILL CONTINUE TO EXPECT TO SEE
SHOWERS AND THUNDERSTORMS DEVELOP ALONG THE BOUNDARY THIS MORNING
AND CONTINUE THROUGH TODAY WITH ANY ADDITIONAL HEATING. SLOW
MOVEMENT OF STORMS IS ALSO EXPECTED WITH LOCALLY HEAVY RAINFALL
LEADING TO POSSIBLE LOCALIZED FLOODING. AS DRIER AIR CONTINUES TO
FILTER IN ACROSS THE NORTHERN PORTIONS OF THE CWA...RAIN CHANCES
WILL DIMINISH THROUGH THE LATE MORNING WITH CHANCES REMAINING
ACROSS THE SOUTHERN CWA THROUGH THE AFTERNOON. SLIGHT LULL THIS
EVENING SHOULD OCCUR...WITH REDEVELOPMENT OVER THE WATERS TONIGHT
AS REMNANTS OF THE BOUNDARY LAY DRAPED ACROSS THE CWA. THE MAIN
UPPER TROUGH AXIS WILL SWING THROUGH SUNDAY...PUSHING THE BOUNDARY
FARTHER SOUTH. AS THIS OCCURS...REMAINING INSTABILITY AND MOISTURE
WILL LEAD TO SLIGHT CHANCES FOR ACTIVITY MAINLY ACROSS THE WATERS
AND COASTAL BEND LOCATIONS. TEMPERATURES SHOULD BE COOLER THAN
DAYS PAST ALTHOUGH REMAIN IN THE 90S THROUGH THE PERIOD.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...EXTENDED PERIOD BEGINS
WITH THE USUAL SUMMER HIGH PRESSURE RIDGE BEGINNING TO REASSERT
ITSELF OVER THE EFFECTS OF AN UNSEASONABLE FRONTAL BOUNDARY.
PRECIPITABLE WATER AMOUNTS RETURN TO NEAR SEASONABLE LEVELS AND
THERMAL PROFILES INDICATE WARMER TEMPERATURES ALOFT...ALL OF WHICH
WILL COMBINE TO MAKE PRECIPITATION LESS AND LESS LIKELY AS THE WEEK
PROGRESSES.
THOSE WARMER TEMPERATURES APPEAR LIKELY TO TRANSLATE INTO CONTINUED
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE WEEK. EXPECT
HEAT INDICES TO REMAIN ELEVATED BUT BELOW ADVISORY CRITERIA. MARINE
FLOW SHOULD REMAIN NEARLY STEADY STATE WITH TYPICAL DIURNAL
VARIATIONS. GRADIENT MAY TIGHTEN A SMALL AMOUNT TOWARD THE END OF
NEXT WEEK...BUT SHOULD REMAIN SAFELY BELOW SCA VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 88 76 95 74 94 / 30 10 20 20 20
VICTORIA 91 73 95 73 94 / 10 10 10 10 20
LAREDO 93 78 99 80 100 / 30 20 10 10 10
ALICE 89 75 97 73 97 / 30 10 20 10 20
ROCKPORT 84 77 90 78 91 / 20 10 20 20 20
COTULLA 95 75 98 76 98 / 20 10 10 10 10
KINGSVILLE 90 75 96 74 95 / 30 10 20 10 20
NAVY CORPUS 84 78 90 78 91 / 30 10 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1025 AM CDT SAT AUG 2 2014
.DISCUSSION...CONVECTION EARLIER THIS MORNING STARTING TO MOVE OUT
OF THE AREA. WILL SEE (AND ALREADY ARE SEEING) SOME CLEARING OVER
THE NORTHEASTERN AREAS. LAPS DATA CONTINUES TO SHOW A MORE STABLE
AIRMASS MOVING SOUTHWARD FARTHER INTO THE CWFA. STILL SOME
MOISTURE AVAILABLE THIS AFTERNOON AND WITH DAYTIME HEATING...COULD
SEE SOME ADDITIONAL CONVECTION. HOWEVER...THINK ACTIVITY WILL BE
MORE ISOLATED IN NATURE...WITH THE BETTER CHANCES OF RAIN THIS
AFTERNOON NEAR THE RIO GRANDE (ALTHOUGH UPSLOPE FLOW IS WEAK).
THUS...LOWERED RAIN CHANCES THIS AFTERNOON MOST AREAS AND ONLY
WENT WITH A SLIGHT CHANCE THIS EVENING. CURRENT HRRR DATA SHOWS NO
ADDITIONAL CONVECTION THIS AFTERNOON...AND THIS KIND OF LINES UP
WITH CURRENT TRENDS. UPDATES SENT...UPDATED MOST GRID PARAMETERS
THROUGH 06Z. FOR NOW...WILL LEAVE REMAINDER OF FORECAST AS-
IS...SINCE WOULD LIKE TO LOOK AT MORE NEW DATA SINCE SUBTLE
CHANGES IN MOISTURE AND/OR POSITION OF BOUNDARY COULD HAVE A BIG
EFFECT ON RAIN CHANCES AFTER MIDNIGHT TONIGHT THROUGH SUNDAY.
&&
.MARINE...KEPT SCATTERED CONVECTION OVER THE OFFSHORE WATERS
(HIGHER CAPES/LITTLE TO NO CIN)...BUT ADJUTED THEM DOWN-WARD FOR
THE BAYS/NEARSHORE. NOT MUCH IN WIND OUTSIDE OF CONVECTION.
&&
.PREV DISCUSSION... /ISSUED 809 AM CDT SAT AUG 2 2014/
DISCUSSION...QUICK UPDATE TO INCREASE POPS FARTHER SOUTH AND
INCREASE QPF. UPDATES ARE SENT.
PREV DISCUSSION... /ISSUED 634 AM CDT SAT AUG 2 2014/
DISCUSSION...UPDATED FOR THE 12Z AVIATION DISCUSSION.
AVIATION...CONVECTION ACROSS SOUTH TEXAS EXPECTED TO AFFECT AREAS
FROM CRP-ALI EARLY THIS MORNING...WITH DEVELOPMENT EXPECTED TO
REACH LRD DURING THE LATE MORNING. VCT MAY CONTINUE TO SEE ISOLATED
SHOWERS THROUGH MID MORNING BUT WITH DRIER AIR MOVING IN FROM THE
NORTH...SHOULD GENERALLY SEE A DECREASE IN ACTIVITY AT VCT WITH
VFR THROUGH THE TAF PERIOD. FOR THE REMAINING THREE
SITES...MVFR/VFR CIGS THIS MORNING SHOULD LIFT TO PREDOMINANTLY
VFR AS THE DAY PROGRESSES. HOWEVER MVFR CONDITIONS WILL BE
POSSIBLE IN AND AROUND ANY THUNDERSTORMS THROUGH THE AFTERNOON
WITH WIND GUSTS UP TO 25KTS POSSIBLE. OTHERWISE WINDS WILL
GENERALLY BE LIGHT OUT OF THE EAST-NORTHEAST. MAY SEE ISOLATED
SHOWERS ONCE MORE LATE IN THE TAF PERIOD FOR THE COASTAL SITES BUT
DUE TO ISOLATED DEVELOPMENT IN NATURE...WILL NOT MENTION IN TAFS.
PREV DISCUSSION... /ISSUED 423 AM CDT SAT AUG 2 2014/
SHORT TERM (TODAY THROUGH SUNDAY)...LAPS DATA CURRENTLY HAS THE
WEAK FRONT DRAPED ACROSS THE CWA FROM COTULLA TO BEEVILLE TO PORT
LAVACA. MOISTURE REMAINS ABUNDANT WITH NEAR 2.3 INCHES ACROSS MUCH
OF THE AREA. WITH THE FRONT CLOSER IN PROXIMITY...MOISTURE DEPTH
HAS INCREASED AS WELL. THEREFORE...WILL CONTINUE TO EXPECT TO SEE
SHOWERS AND THUNDERSTORMS DEVELOP ALONG THE BOUNDARY THIS MORNING
AND CONTINUE THROUGH TODAY WITH ANY ADDITIONAL HEATING. SLOW
MOVEMENT OF STORMS IS ALSO EXPECTED WITH LOCALLY HEAVY RAINFALL
LEADING TO POSSIBLE LOCALIZED FLOODING. AS DRIER AIR CONTINUES TO
FILTER IN ACROSS THE NORTHERN PORTIONS OF THE CWA...RAIN CHANCES
WILL DIMINISH THROUGH THE LATE MORNING WITH CHANCES REMAINING
ACROSS THE SOUTHERN CWA THROUGH THE AFTERNOON. SLIGHT LULL THIS
EVENING SHOULD OCCUR...WITH REDEVELOPMENT OVER THE WATERS TONIGHT
AS REMNANTS OF THE BOUNDARY LAY DRAPED ACROSS THE CWA. THE MAIN
UPPER TROUGH AXIS WILL SWING THROUGH SUNDAY...PUSHING THE BOUNDARY
FARTHER SOUTH. AS THIS OCCURS...REMAINING INSTABILITY AND MOISTURE
WILL LEAD TO SLIGHT CHANCES FOR ACTIVITY MAINLY ACROSS THE WATERS
AND COASTAL BEND LOCATIONS. TEMPERATURES SHOULD BE COOLER THAN
DAYS PAST ALTHOUGH REMAIN IN THE 90S THROUGH THE PERIOD.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...EXTENDED PERIOD BEGINS
WITH THE USUAL SUMMER HIGH PRESSURE RIDGE BEGINNING TO REASSERT
ITSELF OVER THE EFFECTS OF AN UNSEASONABLE FRONTAL BOUNDARY.
PRECIPITABLE WATER AMOUNTS RETURN TO NEAR SEASONABLE LEVELS AND
THERMAL PROFILES INDICATE WARMER TEMPERATURES ALOFT...ALL OF WHICH
WILL COMBINE TO MAKE PRECIPITATION LESS AND LESS LIKELY AS THE WEEK
PROGRESSES.
THOSE WARMER TEMPERATURES APPEAR LIKELY TO TRANSLATE INTO CONTINUED
NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES THROUGH THE WEEK. EXPECT
HEAT INDICES TO REMAIN ELEVATED BUT BELOW ADVISORY CRITERIA. MARINE
FLOW SHOULD REMAIN NEARLY STEADY STATE WITH TYPICAL DIURNAL
VARIATIONS. GRADIENT MAY TIGHTEN A SMALL AMOUNT TOWARD THE END OF
NEXT WEEK...BUT SHOULD REMAIN SAFELY BELOW SCA VALUES.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 88 76 95 74 94 / 30 10 20 20 20
VICTORIA 91 73 95 73 94 / 10 10 10 10 20
LAREDO 93 78 99 80 100 / 30 20 10 10 10
ALICE 90 75 97 73 97 / 30 10 20 10 20
ROCKPORT 85 77 90 78 91 / 20 10 20 20 20
COTULLA 95 75 98 76 98 / 20 10 10 10 10
KINGSVILLE 91 75 96 74 95 / 30 10 20 10 20
NAVY CORPUS 85 78 90 78 91 / 30 10 20 20 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1043 PM EDT SUN AUG 3 2014
.SYNOPSIS...
AN UPPER TROUGH RESIDES OVER THE REGION THROUGH TUESDAY...BUT THE
OVERALL FLOW TURNS MORE TO THE WEST. MEANWHILE...BERTHA STAYS WELL
OFFSHORE HEADING INTO THE WORKWEEK. A COLD FRONT IS EXPECTED TO
DROP TO THE MID ATLANTIC AND SOUTHERN APPALACHIANS BY THURSDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1030 PM EDT SUNDAY...
AN UPPER LOW PRESSURE WAS CENTERED OVER WESTERN PA...WITH ITS
ASSOCIATED TROUGH AXIS TRAILING SOUTH INTO THE CENTRAL APPALACHIANS.
A FRONTAL BOUNDARY WAS STALLED ALONG THE COASTS OF NC AND SC. THE
WEDGE OF HIGH PRESSURE ALONG THE LEE OF THE APPALACHIANS HAS
ERODED.
FOR THE OVERNIGHT...WILL HAVE TO MONITOR THE UPPER TROUGH AXIS FOR
POTENTIAL SHOWER DEVELOPMENT. AS OF 10PM THE TROF AXIS WAS
POSITIONED NR THE BLUE RIDGE...WITH A NARROW AXIS OF MOISTURE
CONVERGENCE PRESENT FROM THE DC AREA IN NORTHERN VA...TO NEAR
GREER SOUTH CAROLINA...PASSING THROUGH OUR CWA WAY OF A
LYH...MTV...MWK LINE. WITHIN THIS NARROW CORRIDOR...SHOWERS ARE
POSSIBLE. ATTM THE GREATEST COVERAGE WAS NORTH OF OUR CWA FROM
CHO-DCA. OTHER SHOWERS...MORE ISOLATED IN NATURE...WERE OCCURRING
FROM MOUNT AIRY NC...MWK...TO HICKORY...HKY. THE HRRR MODEL
MAINTAINS AREA OF LIFT VCNTY OF THE NW PIEDMONT OF NC THROUGH
ABOUT 06Z/2AM...SO LIKEWISE MAINTAINED THE HIGHEST POPS WITHIN
OUR CWA TO THIS CORRIDOR THROUGH MIDNIGHT.
AFTER MIDNIGHT...CONVECTION IS EXPECTED TO WANE. PATCHY FOG IS
THEN EXPECTED TO DEVELOP WITH A RETURN OF LOW LEVEL STRATUS
CLOUDS IN AND AROUND THE AREAS OF FOG. LOWS TONIGHT WILL RANGE
FROM THE MID TO UPPER 50S ACROSS THE MOUNTAINS WITH LOW TO MID 60S
ACROSS THE PIEDMONT.
ON MONDAY...MODELS DIFFER ON THE IMPACT SURFACE LOW PRESSURE THAT
FORMS ALONG THE STALLED FRONT ALONG THE COAST OF THE CAROLINAS
IMPACTS OUR WEATHER AS IT MOVES NORTHWARD ALONG THE FRONT. THE NAM
IS THE MOST AGGRESSIVE IN BRINGING A SUBSTANTIAL SLUG OF MOISTURE
INTO AT LEAST THE SOUTHEAST PART OF THE AREA BY TOMORROW AFTERNOON.
THIS IS A SUBSTANTIAL AMOUNT COMPARED TO GFS/ECWMF/CANADIAN
SOLUTIONS WHICH KEEP THE ACTIVITY MORE TO OUR EAST. THE NAM HAS BEEN
OVERDOING PRECIPITATION AMOUNTS AND HAS BEEN OFF ON THE BULLSEYE OF
PRECIPITATION CENTERS THAT PAST FEW DAYS...AND LIMITED CREDENCE WILL
BE GIVEN TO ITS LATEST SOLUTIONS. THE DRIER GFS/ECMWF/CANADIAN
SOLUTIONS WILL CONTINUE TO BE FAVORED IN OUR FORECAST. THIS DOES NOT
MEAN NO PRECIPITATION...BUT RATHER MORE OF ISOLATED DAYTIME
CONVECTION MAINLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE
WHERE LOW LEVEL TRAJECTORIES WILL ADD AN ELEMENT OF UPSLOPE. FOR
HIGH TEMPERATURES...FAVORING A SOLUTION THAT IS CLOSER TO THE MILDER
MOSGUIDE GRIDS AS COMPARED TO THE COOLER ADJMET. BELIEVE THE LATTER
IS BEING IMPACTED BY THE GREATER ABUNDANCE OF PRECIPITATION IT WANTS
TO GENERATE OVER THE REGION TOMORROW AFTERNOON...ESPECIALLY IN THE
SOUTHEAST PART OF THE AREA.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM EDT SUNDAY...
KEEPING THIS FORECAST CLOSER TO THE 00Z ECMWF SOLUTION WITH THE 12Z
GFS NOT TOO FAR OUT OF TOLERANCE WITH THE ECMWF. STILL LOOKING AT
TROUGH SITUATED OVER THE EAST...BUT EXPECTING RISING HEIGHTS AT 5H
INTO WEDNESDAY WITH INCREASED WESTERLY FLOW ALOFT AHEAD OF THE NEXT
FRONT.
FOR SHOWERS AND STORMS...EXPECT ISOLATED/SCATTERED ACROSS THE
MOUNTAINS AND FOOTHILLS TUESDAY WITHIN SFC CONVERGENT FIELD...WHILE
DEPARTING BERTHA OUT WELL EAST OF HATTERAS SHIFTS NE AWAY FROM LAND.
DIURNAL CONVECTION MAINLY AGAIN WEDNESDAY ALTHOUGH MAY LESS WITH
DOWNSLOPE INCREASING ALOFT. WILL HAVE SLIGHT TO LOW CHANCE SHRA/TSRA
ALONG AND WEST OF THE BLUE RIDGE WEDNESDAY AFTERNOON.
HIGHS WILL START WORKING BACK TO AT OR ABOVE NORMAL EAST OF THE
MOUNTAINS TUE-WED WITH HIGHS IN THE UPPER 80S/LOWER 90S...WHILE THE
MOUNTAINS WILL STAY CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH
LOWER 80S...THOUGH SOME MID 80S IN THE VALLEYS OF THE I-81 CORRIDOR.
HIGH LEVEL CLOUD COVER AHEAD OF THE FRONT WEDNESDAY MAY ROLL IN
FASTER THAN LATE AFTERNOON AS DEPICTED OFF THE ECWMF...WHICH
COULD BRING HIGHS A LITTLE LOWER IN THE MOUNTAINS/FOOTHILLS...BUT
STILL VERY WARM.
LOWS WILL BE CLOSE TO NORMAL MON-TUE NIGHT WITH UPPER 50S/LOWER 60S
MOUNTAINS TO MID TO UPPER 60S EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
AS OF 750 PM EDT SUNDAY...
GENERALLY VFR CONDITIONS EXPECTED THROUGH THE TAF VALID PERIOD
OUTSIDE LATE NIGHT/EARLY MORNING FOG AT THE USUAL SPOTS. AIR MASS
CONSIDERABLY DRIER THAN 24 HRS AGO. ANY REMAINING LATE DAY CU WILL
DISSIPATE QUICKLY WITHIN THE NEXT HOUR OR SO. CIRRUS WILL STREAM
ACROSS THE SE PARTS OF THE CWA AS MOISTURE REMAINS ANCHORED ALONG
COASTAL FRONT AND WEAK LOW PRESSURE AREA DEVELOPING ALONG GA/SC
COAST. WITH RESPECT TO FOG POTENTIAL...THIS IS CONSIDERABLY MORE
QUESTIONABLE THAN LAST NIGHT...WHEN LATE DAY RAIN CONTRIBUTED TO
WIDESPREAD IFR-LIFR CONDITIONS ACROSS THE WESTERN SITES. DEWPOINTS
HAVE DROPPED SEVERAL DEGREES IN THE WEST FROM 24 HRS AGO AND
LIGHT NW WINDS TODAY HAVE SCOURED OUT SOME OF THE LOW-LEVEL
MOISTURE AS WELL. HOWEVER...MOSTLY CLEAR SKIES AND LIGHT/CALM
WINDS WILL LEAD TO MORE FAVORABLE RADIATIONAL COOLING TONIGHT...SO
AT LEAST PATCHY DENSE FOG AT LWB AND BCB SEEMS TO BE A REASONABLE
PROJECTION AT THIS POINT. FOG POTENTIAL AT BLF SHOULD BE
CONSIDERABLY LESS THAN LAST NIGHT...AND IN FACT THEY MAY END UP
WITH NONE AT ALL. FOG DEVELOPMENT AT LYH/DAN MOST PROBLEMATIC AND
COULD GO EITHER WAY. HAVE PRETTY MUCH MAINTAINED EXISTING FORECAST
AT THOSE LOCATIONS. NO FOG IS EXPECTED AT ROA. AT LOCATIONS WHICH
SEE LIFR IN FOG...IFR-LIFR VV CIGS ALSO EXPECTED. SCT CU AND SCT-
BKN CI...ESPECIALLY EAST OF THE BLUE RIDGE MON...OTHERWISE VFR AFT
14Z. WINDS...MOSTLY LIGHT/VARIABLE THROUGH THE TAF VALID
PERIOD...ALTHOUGH TENDENCY FOR NE WINDS EAST OF THE BLUE RIDGE IN
RESPONSE TO COASTAL TROUGH/FRONT AND NW WINDS WEST OF THE BLUE
RIDGE IN RESPONSE TO OH VALLEY HIGH PRESSURE.
MEDIUM CONFIDENCE IN CIGS 06Z-14Z...OTHERWISE HIGH CONFIDENCE IN
VFR CIGS.
LOW TO MEDIUM CONFIDENCE IN VSBYS 06Z-14Z...OTHERWISE HIGH
CONFIDENCE IN VFR VSBYS.
MEDIUM CONFIDENCE IN WIND DIR...HIGH CONFIDENCE IN WIND SPD THROUGH
THE TAF VALID PERIOD.
EXTENDED AVIATION DISCUSSION...
ANOTHER BROAD UPPER TROUGH WILL BECOME POSITIONED ACROSS THE
EASTERN THIRD OF THE UNITED STATES BY EARLY NEXT WEEK. AN
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY. FOR AVIATION
CONCERNS...MONDAY INTO TUESDAY WILL HAVE LIMITED PRECIPITATION
CHANCES...ISOLATED AT BEST...BUT THE POTENTIAL FOR OVERNIGHT
PATCHY FOG AND LOW STRATUS IN THE MOUNTAIN AND RIVER VALLEYS.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH ONGOING SHOWER AND SOME THUNDERSTORM ACTIVITY IN ASSOCIATION
WITH THE COLD FRONT. LIKEWISE...A GREATER ABUNDANCE OF LINGERING
OVERNIGHT SUB-VFR CONDITIONS ARE LIKELY WITH BOUNDARY LAYER
MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION. IF THERE IS
LIMITED MOVEMENT OF THE FRONT BY FRIDAY...EXPECT SIMILAR
CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...DS/PM
SHORT TERM...WP
LONG TERM...CF
AVIATION...DS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
123 AM EDT SAT AUG 2 2014
.SYNOPSIS...
A STATIONARY FRONT ALONG THE ATLANTIC SEABOARD WILL REMAIN EAST OF
THE AREA THIS WEEKEND AS A WEDGE OF HIGH PRESSURE ALONG THE
APPALACHIANS BEGINS TO SLOWLY ERODE INTO SUNDAY. WEAK DISTURBANCES
RIDING ALONG THIS RESIDUAL FRONT WILL BRING ADDED CHANCES OF
SHOWERS AND THUNDERSTORMS OVER THE NEXT COUPLE OF DAYS. WEAK HIGH
PRESSURE BUILDS IN ON MONDAY BRINGING WARMER AND DRIER AIR FOR
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1135 PM EDT FRIDAY...
VERY MINOR UPDATE FOR POPS GIVEN MOST OF RAIN HAS MOVED TO THE
NORTHEAST...AND HAVE CONTINUED TO TREND DOWN MUCH OF THE REST OF
THE NIGHT GIVEN LATEST HRRR EVEN DRIER OVERNIGHT. SOME
TEMPS...ESPECIALLY IN THE PIEDMONT HAVE DROPPED A COUPLE MORE
DEGREES SO NEEDED TO PULL MINS DOWN IN SOME LOCATIONS ANOTHER
NOTCH. SPREAD SOME OF THE FOG/DRIZZLE BACK A LITTLE FARTHER WEST
IN SPOTS AND MADE SURE ENTIRE BLUE RIDGE WAS INCLUDED.
PREV DISCUSSION AS OF 930 PM EDT FRIDAY...
COVERAGE OF SHOWERS CONTINUES TO WANE AS THE UPPER WAVE IS NOW
SHIFTING EAST OF THE FCST AREA. STEADIER AREA OF LIGHT RAIN WILL
BE EAST OF OUR AREA BEFORE MIDNIGHT...LEAVING ONLY VERY LIGHT
SCATTERED SHOWERS OR DRIZZLE ALONG THE BLUE RIDGE AND EAST.
EVENING SOUNDINGS STILL SHOW ABOVE NORMAL PRECIP WATER VALUES AND
THERE IS STILL A GOOD LOW LEVEL EASTERLY COMPONENT SEEN IN THE
SOUNDINGS AND VWP FROM THE RADAR...SO CANNOT RULE OUT VERY
SHALLOW UPSLOPE DRIZZLE OR SHOWERS ALTHOUGH THEY MAY BE HARD TO
DETECT ON RADAR. WE BEGIN TO LOSE THE EASTERLY COMPONENT AT THE RIDGE
TOP LEVEL LATE TONIGHT ACCORDING TO SOUNDING FCSTS...BUT THINK LOW
LEVEL WEDGE WILL BE HOLDING STRONG AND SO WORTH KEEPING MENTION
OF DRIZZLE AND AREAS OF FOG ALL NIGHT. BUT GIVEN THESE TRENDS AND
THE LATEST HRRR AND RAP MODEL RUNS WHICH ARE HANDLING THINGS
PRETTY WELL NOW AND SHOW ONLY VERY LITTLE IN THE WAY OF SCT SHWRS
HERE AND THERE ACROSS NORTHERN PART OF FCST AREA...HAVE GENERALLY
LOWERED POPS EVEN MORE FOR REST OF OVERNIGHT TO LOW TO MID CHC
BLUE RIDGE AND EAST...AND NOTHING OR JUST SLIGHT CHC WEST.
OTHER CHANGE FOR OVERNIGHT WAS TO LOWER MIN TEMPS IN PARTS OF THE
PIEDMONT GIVEN FACT THAT CURRENT TEMPS IN A FEW SPOTS WERE ALREADY
AS LOW AS PREVIOUSLY FCST MINS...ALTHOUGH DON`T THINK IN MOST
CASES CURRENT TEMPS WILL DROP MORE THAN A FEW MORE DEGREES FROM
WHAT THEY ARE NOW...IF ANYTHING.
PRELIM LOOK AT TOMORROW SUGGESTS WEDGE WILL TRY TO BREAK DURING
THE DAY...BUT MAY HOLD ON AS LONG AS POSSIBLE OVER NRV AND PARTS
OF PIEDMONT...WHILE BREAKING EARLY ACROSS SOUTHWEST AND FAR WEST.
TEMPS WILL BE TRICKY GIVEN THE BREAKING WEDGE...AND THINK BEST
CHANCE FOR SHOWERS AND STORMS WILL BE THESE FAR WESTERN FRINGES
WERE SUN IS OUT THE LONGEST. WARMER AT BLF LIKELY AGAIN COMPARED
TO LYH. NO CHANGES IN THAT PERIOD YET THOUGH AS WE AWAIT MORE
GUIDANCE FROM OVERNIGHT.
PREV DISCUSSION AS OF 614 PM EDT FRIDAY...
CURRENT RADAR SUGGESTS THAT MAIN LIFT WITH UPPER WAVE THAT IS
MOVING NORTHEAST OUT OF WRN NORTH CAROLINA IS SHIFTING INTO THE
PIEDMONT AREAS AND WHAT UPSLOPE ALONG THE BLUE RIDGE EXISTS THIS
EVENING IS PRODUCING RELATIVELY SMALL AREAS OF LIGHT RAIN AND
DRIZZLE. MOST OF THE NEAR TERM GUIDANCE THAT IS SIMILAR TO THE
RADAR NOW SUGGESTS MUCH OF THIS WILL GRADUALLY WEAKEN BY LATE
EVENING WHILE THE MORE MODERATE RAINFALL IN THE EAST QUICKLY
SHIFTS OFF TO THE NORTHEAST. HARD TO SEE ANY REASONING FOR MUCH OF
ANY SHOWER ACTIVITY DEVELOPING ON THE WEST EDGE OF THE CWA AND THE
WEDGE GIVEN THAT DAYTIME INSTABILITY WILL BE LOST SOON. THUS AM
LOWERING POPS FOR MOST OF THE WEST TO SLIGHT CHC WITH SOME LOW CHC
REMAINING UP ACROSS GREENBRIER IN CASE ANY SHALLOW CONVECTION
FARTHER NORTH BACKBUILDS...AND GRADUALLY LOWER THE LIKELY POPS
ALONG THE BLUE RIDGE THE CHC OF SHOWERS AND DRIZZLE BY LATE
EVENING INTO THE OVERNIGHT. CATEGORICAL FAR EAST FOR JUST ANOTHER
COUPLE HOURS THEN DROPPING OFF TO MID CHC...AND WILL DETERMINE
LATE IF WE NEED TO DROP THAT EVEN MORE FOR MUCH OF THE OVERNIGHT
WHEN THIS UPPER WAVE HAS MOVED OFF...LEAVING WEAKENING UPSLOPE
ALONG BLUE RIDGE AS 850 FLOW TURNS MORE SW BEHIND IT. DON`T THINK
THIS SW FLOW WILL BE ABLE TO ERODE THE WEDGE OVERNIGHT HOWEVER...SO
AM KEEPING CLOUDS AND AREAS OF DRIZZLE AND FOG IN ALL NIGHT. MADE
SOME MINOR ADJUSTMENTS TO SKY COVER ON WESTERN FRINGE WHERE SOME
PARTIAL CLEARING HAS TAKEN PLACE ON THE EDGE OF THE WEDGE...BUT
THIS MAY FILL BACK IN AFTER DARK.
ALSO PULLED MENTION OF HEAVY RAINFALL FROM THE HWO AS THERE ARE
NOT ANY EXPECTATIONS OF RAINFALL RATES HIGH ENOUGH TO CAUSE EVEN
MINOR ISSUES EXCEPT FOR SOME PONDING IN LOW-LYING STREETS IN THE
EAST.
PREV DISCUSSION AS OF 340 PM EDT FRIDAY...
TWO DISTINCT SHORT WAVES SEEN ON THE WATER VAPOR LOOP THE FIRST
MOVING ACROSS WEST VIRGINIA AND VIRGINIA HELPED GENERATE THE LARGE
SHIELD OF RAIN FROM THIS MORNING. THE SECOND VORTICITY MAXIMUM WAS
APPROACHING SOUTH CAROLINA AND WAS FORECAST TO MOVE INTO VIRGINIA
OVERNIGHT.
BUFKIT FORECAST SOUNDINGS SHOWED NORTHEAST WINDS AT THE SURFACE
EAST OF THE BLUE RIDGE...20-25 KNOT EAST TO SOUTHEAST 850 MB WINDS
TONIGHT AND SOUTHWEST WINDS ALOFT. THIS TRANSITIONS TO SOUTHWEST
WINDS AT 850 MB AS THE WEDGE AND MOISTURE BECOMES SHALLOW ON
SATURDAY.
THE COMBINATION OF LIFT FROM THE CAROLINA WAVE AND UPSLOPE FLOW
WILL RESULT IN RAIN ALONG AND EAST OF THE BLUE RIDGE TONIGHT. MOST
OF THE SHORT TERM GUIDANCE HAD THE MORE WIDESPREAD AND STEADIER
LIGHT TO MODERATE RAIN MOVING NORTHEAST OUT OF THE FORECAST AREA
AFTER MIDNIGHT. THEN OVERNIGHT...PRECIPITATION WILL BE MORE SPOTTY
LIGHT RAIN AND DRIZZLE. ALSO ADDED AREAS OF FOG IN THE TYPICAL
AREAS WHERE THE WEDGE IS IN PLACE.
TEMPERATURES ON SATURDAY WILL BE DEPENDENT ON WHEN WEDGE ERODES.
EXPECTING TYPICAL SOUTHWEST TO NORTHEAST PROGRESSION...WITH
LYNCHBURG AND THE NORTHEAST COUNTIES OF THE FORECAST AREA THIS
LAST TO BREAK OUT.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
AS OF 250 PM EDT FRIDAY...
THROUGHOUT MOST OF THIS PORTION OF THE FORECAST...THE AXIS OF THE
ESTABLISHED UPPER LEVEL TROUGH WILL REMAIN POSITIONED JUST WEST OF
THE FORECAST AREA. THIS WILL CONTINUE TO ALLOW FOR A GOOD MOISTURE
FETCH OFF THE ATLANTIC TO PROGRESS INTO THE REGION. THE INTERPLAY OF
UPSLOPE CONDITIONS ALONG AND NEAR THE CREST OF THE BLUE RIDGE AND
WEAK DISTURBANCES ROUNDING THE BASE OF THE MAIN TROUGH AXIS...WILL
KEEP THE CHANCE OF SHOWERS AND AFTERNOON/EARLY EVENING ISOLATED
THUNDERSTORMS ACROSS OUR AREA DURING THIS PERIOD.
WHILE THE MAIN UPPER TROUGH WILL REMAIN TO OUR WEST...THERE WILL BE
A CHANGE IN JUST HOW THIS FEATURE IS MATERIALIZED. THROUGH ROUGHLY
FRIDAY MORNING...THE FEATURE WILL BE THE BASE OF A CLOSED LOW
SYSTEM NEAR HUDSON BAY CANADA. THIS LOW HOWEVER WILL SHIFT EAST BY
THE START OF THE WEEKEND...ALLOWING THIS MAIN UPPER TROUGH TO FADE
IN INTENSITY ONLY BRIEFLY. BY SUNDAY...THE REMNANT OF THIS FIRST
UPPER TROUGH WILL BE STRENGTHENED BY A SHORTWAVE TROUGH
PROGRESSING EASTWARD INTO THE TENNESSEE AND OHIO VALLEYS FROM THE
WEST. DESPITE THIS FLUCTUATION...THE OVERALL FORECAST WILL BE AS
DESCRIBED ABOVE.
THE TIME PERIOD WHEN PRECIPITATION CHANCES WILL BE AT THEIR LOWEST
IS MONDAY NIGHT WHEN THE LATEST GUIDANCE OFFERS A SOLUTION OF
BROADENING THE WIDTH OF THE TROUGH...AND SHIFTING THE AXIS A LITTLE
FARTHER EAST. THIS IS EXPECTED TO HAVE THE RESULT OF LIKEWISE
SHIFTING THE BEST CHANCES OF PRECIPITATION EAST OF THE FORECAST AREA.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 1230 PM EDT FRIDAY...
AT THE SURFACE TUESDAY...HIGH PRESSURE SITS OVER WEST VIRGINIA WHILE
A SLOW MOVING COLD FRONT IS ACROSS THE OHIO VALLEY. TS BERTHA OR
WHAT IS REMAINING OF IT IS FORECAST TO REMAIN WELL OFF SHORE AND
WILL NOT BE A FACTOR IN OUR REGION NEXT WEEK. AN UPPER LEVEL TROUGH
REMAINS SITUATED ACROSS THE EASTERN US. THE UPPER LEVEL FLOW WILL
BECOME MORE ZONAL BY THE END OF THE PERIOD. THE FRONT ACROSS THE
OHIO VALLEY WILL SLOWLY DRIFT AND PARTIALLY STALL OUT ACROSS
NORTHERN PORTIONS OF OUR CWA BY THURSDAY INTO FRIDAY. WHILE PWATS
ARE NOT IMPRESSIVE...GENERALLY 0.75-1.25 INCHES DEPENDING ON THE
LOCATION...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS EACH AFTERNOON
BEGINNING DURING PEAK HEATING AND TAPERING OFF AROUND SUNSET. FOCUS
OF THE LOW CHANCE POPS ARE ACROSS THE MOUNTAINS AND GENERALLY NORTH
OF ROUTE 460.
SURFACE TEMPS WILL BE RIGHT AROUND NORMAL FOR THE PERIOD. 850MB
TEMPS OF +15-17C WILL CORRESPOND TO SURFACE HIGHS OF MID TO UPPER
80S EAST OF THE BLUE RIDGE AND LOWER 80S ACROSS THE MOUNTAINS.
DEWPTS IN THE UPPER 50S TO LOWER 60S WILL KEEP NIGHT TIME TEMPS UP A
BIT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 105 AM EDT SATURDAY...
MOST MEASURABLE -RA HAS EXITED THE REGION TONIGHT WITH PERIODIC
BURSTS OF DRIZZLE AROUND MAINLY ALONG AND EAST OF THE BLUE RIDGE
WHERE WIDESPREAD IFR CIGS PERSIST. EXPECT THIS SCENARIO TO
CONTINUE THROUGH DAYBREAK WITH LOW LEVEL EASTERLY FLOW ADDING TO
SPOTTY -DZ DEVELOPMENT ALONG WITH AREAS OF MVFR/IFR FOG FROM KBCB
AND POINTS EASTWARD. MORE VARIABLE CONDITIONS ARE LIKELY ON THE
EDGE OF THE WEDGE AROUND KBLF WHERE WILL BE GOING IN AND OUT OF
MVFR TO VFR OVERNIGHT BUT WITH LESS DZ OR FOG. KLWB MAY SEE JUST
ENOUGH CLOUDS TO DELAY FOG FORMATION UNTIL BETTER CLEARING
DEVELOPS IN THE NEXT FEW HOURS BUT STILL EXPECTING LIFR IN
FOG/STRATUS THERE BEFORE DAWN. THUS HAVE TWEAKED DOWN CIGS IN THE
EAST AND BUMPED UP CIGS/VSBYS TO INIT ACROSS SE WVA THROUGH EARLY
SAT MORNING.
IFR CIGS WILL IMPROVE TO MVFR CIGS BY MID OR LATE MORNING...WITH
LIKELY VFR CIGS WEST OF THE BLUE RIDGE BY AFTERNOON. HOWEVER
SPOTS CLOSER TO THE EASTERN SLOPES OF THE BLUE RIDGE...KROA AND
KLYH MAY BE SLOWER TO SEE LOWER CIGS ERODE UNDER THE PERSISTENT
WEDGE SO HELD IFR THERE UNTIL EARLY AFTERNOON. VSBYS SHOULD
IMPROVE TO VFR AFT 15Z/11AM SAT BUT MAY STAY MVFR IN FOG AT KROA
AND KLYH A BIT LONGER. WINDS...MOSTLY NE- SE THROUGH THE TAF
VALID PERIOD AT SPEEDS OF 5-8KTS...EXCEPT ACROSS SE WEST VA...WHERE
WINDS WILL BE LIGHT NE IN THE MORNING LIKELY BECOMING LIGHT SE TO
SW DURING THE AFTERNOON.
WEDGE SHOULD KEEP THINGS STABLE ENOUGH TO PRECLUDE MUCH SHRA MENTION
IN THE EAST UNTIL LATE IN THE DAY AT MOST WHILE HEATING ON THE
PERIMETER OF THE COOL POOL COULD CAUSE SOME SCATTERING OF TSRA
MAINLY KBLF AND POINTS SOUTH/WEST BY LATE SAT. THIS SUPPORTED BY
SEVERAL MODELS BUT LOOKS QUITE ISOLATED SO ONLY INCLUDING A VCTS
MENTION AT KBLF AND VCSH AT KLWB LATE. WEDGE MAY SPILL BACK TOWARD
THE BLUE RIDGE FOR A WHILE INTO SAT EVENING BEFORE TRAJECTORIES
TURN MORE NW BEHIND A WAVE EXITING TO THE NE SAT NIGHT. THIS
SHOULD ALLOW FOR IMPROVING CIGS SAT NIGHT WITH PERHAPS ONLY THE
EASTERN LOCATIONS HOLDING ONTO MORE MVFR CIGS AND POSSIBLE SHRA.
EXTENDED AVIATION DISCUSSION...
THE BROAD UPPER TROUGH OF LOW PRESSURE WILL LINGER ACROSS THE
EASTERN UNITED STATES THROUGH SUNDAY. LATEST MODEL INDICATIONS ARE
THAT THE TROUGH WILL BEGIN TO SHIFT BACK TO THE EAST BY
SUNDAY/MONDAY...MOVING THE BEST POTENTIAL FOR ANY SHRA/TSRA MAINLY
EAST OF THE REGION WITH TIME. HOWEVER...AN INCREASINGLY WARM/HUMID
AIR MASS ACROSS THE REGION MAY LEAD TO MORE ISOLATED DIURNAL MOUNTAIN
SHRA/TSRA BY SUN- MON BUT SHOULD BE SPOTTY AT BEST SO APPEARS
WIDESPREAD VFR RETURNING BY EARLY NEXT WEEK.
FOR TUESDAY...THE AIR MASS WILL SLOWLY BECOME WARMER AND MORE
UNSTABLE. HOWEVER...DYNAMICS AND FORCING ARE WEAK AT BEST. MAINLY
ISOLD SHRA/TSRA ARE EXPECTED DURING THE AFTERNOON...WITH
BRIEF/LOCALIZED MVFR-IFR VSBYS/CIGS IN SHRA/TSRA...MAINLY
AFTERNOON/EARLY EVENING. LATE NIGHT/EARLY MORNING FOG WILL REMAIN
A PROBLEM EACH DAY...ESPECIALLY AT THE USUAL SITES...SUCH AS
LWB...BCB...AND LYH.
BY WEDNESDAY...A WEAK COLD FRONT MOVES SLOWLY SOUTH FROM THE OHIO
VALLEY ACROSS THE MID ATLANTIC REGION BRINGING SCT SHRA/TSRA TO
THE REGION...MOST NUMEROUS WEST OF THE ALLEGHANY FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH
NEAR TERM...AMS/SK
SHORT TERM...DS
LONG TERM...CF
AVIATION...JH/RAB
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1043 AM CDT SAT AUG 2 2014
.AVIATION/18Z TAFS/...OVERALL VFR THIS PERIOD. MID LEVEL RIDGING
WITH SUBSEQUENT EASING OF 500 MILLIBAR COLD POOL ALONG WITH LACK
OF ANY LOW LEVEL TRIGGERING MECHANISM ALL POINTS TO KEEPING THE
DRY FORECAST FOR THIS AFTERNOON INTACT. RAP BUFKIT SOUNDINGS
SUGGESTS ONLY SOME VFR BASED SCT CU POTENTIAL. EXPECTING PATCHY
FOG DEVELOPMENT ONCE AGAIN OVERNIGHT. MOS NOT TOO EXCITED THOUGH
SREF VIS PROBS SUGGESTING SOME POTENTIAL IN THE FAR ERN CWA. UPPER
RIDGING BREAKS DOWN FOR SUNDAY WITH WEAK VORT MAXIMA NOTED IN THIS
RENEWED CYCLONIC FLOW. BUFKIT SOUNDINGS ARE UNSTABLE WITH CAPE
VALUES AROUND 1000 J/KG. FOCUSING LOW LEVEL BOUNDARY PROGGD TO
REMAIN TO OUR NORTH. QPF PROGS SUPPORTING OUR LIKELY POPS WHILE
MOS IS SHOWING SLGT CHC/CHC.
PC
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT SAT AUG 2 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE HIGH.
SHORTWAVE RIDGING ALOFT IS EXPECTED FOR THIS AFTERNOON AND TNT. THIS
SHOULD EFFECTIVELY PROVIDE AT LEAST A WEAK CAP ON THE WEAK
INSTABILITY. THE LAKE BREEZE CIRCULATION SHOULD NOT BE SUFFICIENT TO
INITIATE CONVECTION GIVEN THE AFOREMENTIONED FACTORS. THUS WENT DRY
TODAY AND TNT. A WEAK SHORTWAVE TROUGH WILL APPROACH THE MS RIVER BY
12Z SUN WITH PERHAPS SCT CLOUD COVER LATE TNT MOVING INTO SOUTH
CENTRAL WI. FOR HIGH AND LOW TEMPS WENT SLIGHTLY WARMER THAN MOST
GUIDANCE WHICH CORRECTS A COOL BIAS IN THESE SITUATIONS.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM
A SHORTWAVE EMBEDDED IN THE NORTHWEST FLOW SUNDAY WILL BRING MORE
SHOWER/STORM CHANCES TO THE FORECAST AREA. WENT WITH HIGHEST POPS
IN THE EAST WHERE THE LAKE BREEZE MAY CONTRIBUTE TO LOW LEVEL
CONVERGENCE. THOUGH PRECIPITABLE WATER VALUES ARE EXPECTED TO BE
JUST A LITTLE OVER AN INCH...STORM MOTION VECTORS ARE ONLY AROUND
10-15 KNOTS...SO COULD BE SOME LOCALIZED HEAVY RAIN MAKERS.
SOUTHERN WISCONSIN WILL LIKELY BE BETWEEN WAVES DURING THE DAY
MONDAY. KEPT CHANCE POPS GOING THOUGH GIVEN GENERAL CYCLONIC
FLOW...INSTABILITY...AND PRECIPITABLE WATER VALUES UP A LITTLE
HIGHER THAN SUNDAY. SHOULD SEE A SHORTWAVE THEN MOVE THOUGH
MONDAY NIGHT...SO MORE SHOWER/STORM CHANCES.
WILL PROBABLY SEE PRECIP CHANCES LINGER INTO TUESDAY AS THE
SHORTWAVE EXITS THE AREA.
SHOULD SEE TEMPS RIGHT AROUND NORMAL FOR SUNDAY THROUGH TUESDAY.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW
MODELS CONTINUE TO WAVER WITH THE PATTERN FOR THE EXTENDED
FORECAST. THERE WILL LIKELY BE A SWATH OF HIGHER PRECIP CHANCES IN
THE REGION FOR THE SECOND HALF OF THE WEEK...JUST A QUESTION OF
WHERE THIS BAROCLINIC ZONE SETS UP. KEPT LOW CHANCE POPS GOING
THROUGH THIS PERIOD...THOUGH NOT A LOT OF CONFIDENCE IN ANY ONE
PERIOD. COULD FINALLY SEE SOME WIDESPREAD APPRECIABLE RAINFALL
LATER IN THE WEEK IF THE FARTHER NORTHERN SOLUTIONS
VERIFY...THOUGH STILL A LOT OF TIME FOR MODELS TO JUMP AROUND SOME
MORE.
SHOULD SEE TEMPS WITHIN A COUPLE DEGREES OF NORMAL VALUES THROUGH
THE END OF NEXT WEEK.
AVIATION/12Z TAFS/...PATCHY FOG THROUGH SUNRISE MAINLY IN LOW LYING
AREAS. HOWEVER KMSN WILL HAVE VSBYS RANGE FROM 1-3 MILES WHILE KUES
AND KENW MAY HAVE VSBYS DROP TO 3-5 MILES FROM 10-12Z. OTHERWISE MO
CLEAR SKIES OVER FAR ERN WI TODAY AND TNT WITH SCT CUMULUS AROUND 5-
6 KFT FOR KMSN THIS AFTERNOON INTO TNT. LIGHT FOG MAY THEN OCCUR
AGAIN AT KENW AND KUES EARLY MORNING SUNDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1114 PM MDT FRI AUG 1 2014
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
SHOWERS WITH A FEW EMBEDDED TSTORMS ARE DEVELOPING JUST NORTH AND
NORTHWEST OF THE CWA THIS AFTERNOON IN ADVANCE OF A WEAK SHORTWAVE
EVIDENT ON WATER VAPOR MOVING SOUTHEAST ACROSS WYOMING. STILL EXPECT
SOME OF THIS ACTIVITY TO TREK SOUTHWARD INTO THE CWA WHILE ALSO
DEVELOPING ALONG THE PINE RIDGE AND MOUNTAINS OF SOUTHEAST WYOMING.
THUS MAINTAINED A SLIGHT CHANCE FOR ISOLATED THUNDER IN THESE AREAS
THROUGH THE EARLY EVENING. EXTENDED THE RISK SLIGHTLY FURTHER SOUTH
FROM THE PREVIOUS FORECAST TO THE NORTH PLATTE RIVER VALLEY TO LINE
UP WITH DEVELOPING TOWERING CU SEEN ON VIS SAT IMAGERY...IN ADDITION
TO THE LATEST HRRR GUIDANCE. LATEST MESOANALYSIS SHOWS MINIMAL CAPE
IN PLACE ACROSS THE AREA THO...SO NOT EXPECTING THIS ACTIVITY TO
BECOME STRONG NOR WIDESPREAD THIS AFTERNOON.
THE UPPER RIDGE AXIS WILL SLOWLY SHIFT EASTWARD TOWARD THE ROCKIES
TONIGHT AND SATURDAY...WITH THE MID LEVELS LOOKING OVERALL LESS
ENERGETIC THAN TODAY. A WEAK FRONT LOOKS TO DROP SOUTH ACROSS THE
AREA ON SATURDAY...WITH PERHAPS A FEW SHOWERS AND WEAK STORMS
DEVELOPING OVER THE MOUNTAINS IN THE AFTERNOON AS WINDS WILL BECOME
MORE OF AN UPSLOPE COMPONENT BEHIND THE FRONT. WITH MINIMAL UPPER
SUPPORT ANTICIPATED...AM NOT VERY CONFIDENT COVERAGE WILL SHIFT INTO
THE PLAINS...SO CONFINED CHANCES FOR THUNDER TO THE MOUNTAINS.
CONDITIONS WILL REMAIN WARM WITH H7 TEMPS RANGING FROM 10 TO 14C.
SIMILAR CONDITIONS ARE EXPECTED FOR SUNDAY WITH TEMPS A FEW DEGREES
WARMER AS THE THERMAL RIDGE AXIS APPROACHES FROM THE WEST.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 300 PM MDT FRI AUG 1 2014
MODELS IN DECENT AGREEMENT WITH THE OVERALL PATTERN THROUGH NEXT
WEEK...SHOWING MONSOON MOISTURE INCREASING OVER THE FORECAST AREA
AS THE MID TO UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY AHEAD OF
A WEAK SHORTWAVE ACROSS THE EASTERN PACIFIC. AS FOR INDIVIDUAL
DISTURBANCES/SHORTWAVE ENERGY MOVING NORTHWARD AND EVENTUALLY
EASTWARD ACROSS THE AREA...MODELS SHOW POOR CONSISTENCY AND ARE
OUT OF SYNC WITH THE MOVEMENT AND TIMING. THE ECMWF IS INITIALLY
18 TO 24 HOURS LATER THAN THE GFS AND GEM...WITH THE GEM ALSO
MUCH WEAKER WITH THE FIRST DISTURBANCE ON TUESDAY THAN THE OTHER
MODELS. THIS CONTINUES INTO LATE NEXT WEEK WITH THE MAIN SHORTWAVE
TROUGH AS IT MOVES NORTHEAST FROM SOUTHERN CALIFORNIA TO THE
CENTRAL ROCKY MOUNTAINS. THIS IS MAKING POP AND WEATHER FORECASTS
DIFFICULT GOING INTO NEXT WEEK IN TERMS OF WHICH DAYS HAVE THE
HIGHEST POTENTIAL FOR WIDESPREAD RAINFALL AND THUNDERSTORM
OUTBREAKS. THEREFORE...KEPT POP NO HIGHER THAN 40 PERCENT OUTSIDE
OF THE MOUNTAINS DUE TO LOWER THAN AVERAGE CONFIDENCE. DO EXPECT
SHOWERS AND TSTORMS NEARLY EVERYDAY HOWEVER. TUESDAY APPEARS TO BE
THE BEST DAY FOR WIDESPREAD CONVECTION AS THE FIRST DISTURBANCE
MOVES ACROSS WYOMING IN SOME FORM. WEAK WINDS ALOFT MAY RESULT IN
VERY HEAVY RAINFALL AND FLASH FLOODING THROUGH TUESDAY NIGHT.
TEMPERATURES WILL NOT CHANGE MUCH WITH A SUBTROPICAL AIRMASS OVER
THE REGION. EXPECT HIGHS IN THE UPPER 70S TO UPPER 80S...WHICH
WILL BE NEAR OR SLIGHTLY LOWER THAN AVERAGE. KEPT TEMPERATURES A
FEW DEGREES BELOW MOS DUE TO AN OBSERVED WARM BIAS WITH SOUTH TO
SOUTHEAST WINDS ACROSS THE HIGH PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY EVENING)
ISSUED AT 1120 PM MDT FRI AUG 1 2014
VFR CONDITIONS WILL PREVAIL AT ALL AERODROMES THROUGH THE FORECAST
PERIOD. SKIES FOR THE MOST PART WILL BE MOSTLY CLEAR TO PARTLY CLOUDY.
WINDS WILL BE VARIABLE WITH SPEEDS 10 KT OR LESS.
&&
.FIRE WEATHER...
WARM AND MOSTLY DRY CONDITIONS ARE EXPECTED FOR THE DISTRICT
THROUGH THE WEEKEND AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE REMAINS
OVER THE REGION. MINIMUM HUMIDITIES ARE EXPECTED TO DROP INTO THE
UPPER TEENS TO UPPER 20S...WITH 30 PERCENTS IN THE MOUNTAINS. WINDS
WILL REMAIN LIGHT OVERALL...WITH A FEW LOCATIONS ALONG AND WEST OF
THE LARAMIE RANGE GUSTING 15 TO 25 MPH IN THE AFTERNOONS. THERE
REMAINS A SLIGHT CHANCE FOR ISOLATED THUNDERSTORMS THROUGH EARLY
THIS EVENING FOR LOCATIONS WEST OF THE LARAMIE RANGE AND ALSO ALONG
THE PINE RIDGE. THIS ACTIVITY IS NOT EXPECTED TO PRODUCE MUCH
RAIN...WITH AMOUNTS OF ONLY A COUPLE HUNDREDTHS TO ONE TENTH OF AN
INCH. A MUCH BETTER CHANCE OF MORE SUBSTANTIAL PRECIPITATION WILL
OCCUR MONDAY THRU WEDNESDAY OF NEXT WEEK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...RJM
LONG TERM...TJT
AVIATION...JAMSKI
FIRE WEATHER...RJM
AREA FORECAST DISCUSSION
NWS PUEBLO CO
356 AM MDT MON AUG 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM MDT MON AUG 4 2014
AN UPR RIDGE WL REMAIN OVR THE AREA TODAY...BUT WL SHIFT A LITTLE
EASTWARD TONIGHT AS A SHORTWAVE TROF MOVES INTO UT AND WRN CO. THE
HRRR AND WRF SHOW PCPN MOVING OVR THE SAN JUAN AND LA GARITA MTN
AREAS THIS MORNING AND POSSIBLY INTO THE CENTRAL MTNS. RADAR LOOP
SHOWS ECHOES OVR WRN CO THIS MORNING...SO THAT SEEMS REASONABLE.
AROUND NOON...THE WRF AND HRRR DEVELOP SOME VERY ISOLD PCPN OVR SOME
OF THE ERN MTNS. THE MODELS THEN INCREASE PCPN COVERAGE OVR ALL THE
MTNS AREAS THRU THE AFTERNOON HOURS...WITH SOME PCPN ALSO SPREADING
OVR THE SAN LUIS VALLEY. IN THE LATE AFTERNOON...THEY SHOW SOME
ISOLD PCPN MAKING OVR PORTIONS OF THE I-25 CORRIDOR...MAINLY OVR EL
PASO COUNTY AND OVR HUERFANO AND WRN LAS ANIMAS COUNTIES. IN THE
EVENING HOURS THE NAM12 MOVES A LINE OVR PCPN EASTWARD ACRS THE SERN
PLAINS...WHILE THE WRF AND RAP MAINLY JUST KEEPS SOME ISOLD PCPN
WEST OF A LINE FROM CROWLEY...OTERO AND ERN LAS ANIMAS COUNTIES.
HAVE DECIDED TO NOT FOLLOW THE NAMS SOLUTION AND WL THEREFORE KEEP
THE FAR SERN PLAINS DRY. MUCH OF THE PCPN THEN DIES OFF BEFORE
MIDNIGHT...BUT THEN AS A SHORTWAVE TROF MOVES INTO WRN CO LATE
TONIGHT...INCREASED PCPN CHANCES ARE AGAIN EXPECTED OVR THE SWRN
MTNS. HIGH TEMPS TODAY SHOULD BE AROUND TO JUST SLIGHTLY BELOW
AVERAGE IN MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM MDT MON AUG 4 2014
TUESDAY-TUESDAY NIGHT...GENERALLY WEAK WESTERLY FLOW ALOFT PROGGED
ACROSS THE REGION TUESDAY WITH A MINOR EMBEDDED SHORT WAVE
TRANSLATING THROUGH THE FLOW. LATEST MODELS REMAIN CONSISTENT WITH
DRIER AIR EMBEDDED WITHIN THE WESTERLY FLOW ALOFT SLOWLY FILTERING
ACROSS THE AREA TUESDAY...WITH PWATS PROGGED BETWEEN 1/2 INCH ACROSS
WESTERN COLORADO TO AROUND 1 1/4 INCHES ACROSS THE FAR SE PLAINS.
DESPITE THE DRYING ALOFT...SHOULD SEE SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOPING ACROSS THE HIGHER TERRAIN LATE TUESDAY
MORNING WITH INCREASED UVV ASSOCIATED WITH THE PASSING WAVE. STORMS
TO SPREAD EAST ACROSS THE ADJACENT PLAINS AND INTO THE FAR SE PLAINS
THROUGH THE AFTERNOON AND EVENING HOURS. LOCALLY HEAVY RAIN TO
REMAIN POSSIBLE...ALONG WITH POSSIBLE FLASH FLOODING IF THESE STORMS
MOVE OVER AREA BURN SCARS. TEMPERATURES AT OR SLIGHTLY COOLER THAN
SEASONAL AVERAGES CAN BE EXPECTED WITH THE EXPECTED CONVECTIVE CLOUD
COVER.
WEDNESDAY-THURSDAY NIGHT...WEAK TO MODERATE WEST TO SOUTHWEST FLOW
ALOFT CONTINUES ACROSS THE AREA WEDNESDAY AND THURSDAY AS ANOTHER
EMBEDDED SHORT WAVE TRANSLATES ACROSS THE GREAT BASIN AND INTO THE
NORTHERN ROCKIES. DRIER AIR ALOFT CONTINUES TO MOVE INTO THE STATE
WITH MODEL SOUNDINGS INDICATING DEW PTS MIXING OUT INTO THE UPPER
30S AND UPPER 40S ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS AND
REMAINING GENERALLY IN THE 50S ACROSS THE FAR SE PLAINS. THERE IS
ENOUGH MOISTURE REMAINING IN PLACE TO WORK WITH LATE SUMMER SUNSHINE
FOR ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS BOTH DAYS...WITH THE BEST COVERAGE OVER AND NEAR THE
HIGHER TERRAIN. A WEAK COLD FRONT PROGGED TO BACK INTO EASTERN
COLORADO WEDNESDAY MORNING...LOOKS TO HAVE LITTLE AFFECT ON
TEMPERATURES WITH READINGS AROUND SEASONAL AVERAGES EXPECTED. LATEST
MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ELEVATED CONVECTION
ACROSS THE FAR SE PLAINS INTO WESTERN KANSAS THURSDAY EVENING AND
HAVE KEPT SLIGHT POPS IN TACT.
FRIDAY-SUNDAY...UPPER RIDGING BUILDS BACK ACROSS THE STATE WITH
MONSOONAL PLUME SLOWLY INCREASING ACROSS THE AREA. THIS...ALONG WITH
ANOTHER POSSIBLE WEAK COLD FRONT SLIDING ACROSS THE EASTERN
PLAINS...WILL ALLOW FOR INCREASING COVERAGE OF STORMS INTO NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 356 AM MDT MON AUG 4 2014
VFR CONDITIONS ARE EXPECTED AT KCOS...KPUB AND KALS TODAY AND
TONIGHT. KCOS AND KALS MAY SEE TSTMS IN THE VCNTY AFTER 20Z THROUGH
ABOUT 03Z. KPUB COULD ALSO SEE TSTMS IN THE VCNTY AFT 23Z...BUT
CONFIDENCE IN THIS OCCURRING IS LOW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
410 AM EDT MON AUG 4 2014
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RAGGED LOOKING UPPER
LEVEL PATTERN OVER THE CONUS EARLY THIS MORNING. WESTERN RIDGE HAS
BEEN ERODED SOMEWHAT ON ITS WESTERN PERIPHERY DURING THE PAST 24
HOURS AS POTENT ENERGY/CLOSED LOW IMPULSE HAS MIGRATED NORTHWARD
FROM THE BAJA REGION INTO THE SOUTHWESTERN STATES. NORTHERN STREAM
FLOW STILL COMES AROUND THE TOP OF THIS RIDGE AND DIVES BACK
SOUTHWARD THROUGH THE UPPER MIDWEST INTO WHAT HAS BECOME A VERY
STUBBORN EASTERN CONUS UPPER TROUGH. THIS TROUGH EXTENDS DOWN TO THE
NORTHEASTERN GULF COAST BEFORE THE FLOW TURNS BACK NORTHWARD OVER
THE EASTERN SEABOARD. THE PATTERN CURRENTLY OVER OUR HEADS IS RATHER
MESSY AND COMPLEX. THE MAIN EASTERN TROUGH IS NOT DIRECTLY IMPACTING
OUR REGION...HOWEVER A WEAK IMPULSE THAT ARRIVED FROM THE EAST ON
SUNDAY IS NOW SPINNING OVER THE SOUTHERN HALF OF THE STATE...AND HAS
PROVIDED THE SUPPORT AND PERSISTENT LIFT FOR A WET OVERNIGHT OVER
THE SOUTHERN PORTION OF THE STATE. ONLY IN THE PAST HOUR OR TWO
HAVE WE FINALLY SEEN ALL THIS SHOWER ACTIVITY EXIT SOUTH OF OUR
ZONES.
THE MAIN EASTERN UPPER TROUGH WILL EVENTUALLY HELP REMOVE THIS
IMPULSE THROUGH MONDAY AND MONDAY NIGHT AS IT TENDS TO ABSORB THE
ENERGY AND EJECT IT OFF TO THE NORTHEAST. AT THE SAME TIME...THE
UPPER ENERGY ASSOCIATED WITH TROPICAL STORM BERTHA WILL BE LIFTING
NORTHWARD INTO THE WHOLE MIX. SO AS YOU CAN SEE...THE SYNOPTIC
PATTERN AND EVOLUTION OVER THE NEXT 24 HOURS IS KIND OF COMPLEX.
HOWEVER...LUCKY FOR US...THIS MERGER OF ENERGY WILL ALL BE TAKING
PLACE OFF TO THE EAST/NE OF JACKSONVILLE TONIGHT/TUESDAY AND
RAPIDLY HEADING FURTHER OUT TO SEA. THEREFORE...DO NOT ANTICIPATE
ANY ADVERSE IMPACTS FOR OUR FORECAST AREA. PHEW! CLOSE ONE.
AT THE SURFACE...A BROAD SURFACE REFLECTION LOW ASSOCIATED WITH THE
IMPULSE OVERHEAD IS LOCATED OVER THE SOUTHERN/CENTRAL FL PENINSULA.
THIS IS A VERY WEAK LOW WITH PRESSURES ONLY AROUND 1012MB.
&&
.SHORT TERM (TODAY THROUGH TUESDAY)...
ANOTHER DAY WITH AN ILL-DEFINED AND MESSY PATTERN ALOFT BEFORE A
MORE TYPICAL SUMMER PATTERN BEGINS TO RE-EMERGES FOR THE MIDDLE
PORTION OF THE WEEK.
WEAK IMPULSE ALOFT AND ITS ASSOCIATED SURFACE REFLECTION IS SHOWN BY
ALL AVAILABLE NWP GUIDANCE TO SLOWLY MIGRATE NORTHWARD UP THE
FLORIDA EAST COAST THROUGH THE DAY AND THEN BEGIN TO BE ABSORBED
INTO THE MAIN EASTERN CONUS TROUGH AND EJECTED TO THE NORTHEAST
TONIGHT. SIMILAR TO SUNDAY...THE MOIST ATMOSPHERE WITH BOTH UPPER
LEVEL SUPPORT AND BROAD SURFACE FOCUS FOR ASCENT WILL COMPLICATE THE
FORECAST AND MAKE MUCH SPATIAL AND TEMPORAL RESOLUTION IN THE
FORECAST CONVECTIVE PATTERN UNREALISTIC. HOWEVER...WILL DO MY BEST
TO TRY AND GIVE SOME USEFUL DECISION SUPPORT INFORMATION. IN CLOSEST
PROXIMITY TO THE BEST SYNOPTIC SUPPORT...THE SREF/NAM/ECMWF ALL PIN
THE MOST NUMEROUS SHOWER ACTIVITY BY LATE MORNING OVER THE SOUTHERN
HALF OF THE REGION. THIS MAKES SENSE WITH THE IMPULSE ALOFT AND THE
MOST PRONOUNCED SURFACE CONVERGENCE IN THIS REGION. WILL LIKELY TAKE
A FEW HOURS OF HEATING TO REALLY GET THINGS GOING...BUT THEREAFTER
SHOULD BE LOOKING AT SCT TO NMRS SOUTH OF TAMPA BAY. RAIN CHANCES
WILL DECREASE WITH FURTHER NORTHWARD TRAVEL THIS MORNING.
LATER IN THE DAY...THE SURFACE LOW SHOULD REACH THE NORTHERN FLORIDA
PENINSULA. A WEAK WESTERLY FLOW IN THE WAKE OF THIS LOW CENTER WILL
ACT AS...OR HELP THE INLAND PENETRATION OF A WEAK SEA-BREEZE. WITH
THIS IN MIND...WOULD EXPECT THE BEST RAIN CHANCES TO SHIFT INLAND TO
THE I-75 CORRIDOR AND EASTWARD BY THE SECOND HALF OF THE
AFTERNOON/EVENING. FROM COASTAL TAMPA BAY AREA NORTHWARD DURING THE
LATE DAY PERIOD IT IS POSSIBLE THAT WE WILL SEE A PERIOD WITH VERY
LOW RAIN CHANCES SHOULD THIS FLOW DEVELOP IN TIME. FURTHER SOUTH
DOWN TOWARD CHARLOTTE HARBOR...SOME RESIDUAL SURFACE CONVERGENCE
WILL KEEP SCT SHOWERS IN THE FORECAST THROUGH THE DAY.
A MORE DEFINED 1000-700MB WESTERLY FLOW PATTERN SHOULD BECOME
ESTABLISHED BY THE SECOND HALF OF TONIGHT. THIS PATTERN IS ALREADY
CLIMO FAVORED FOR EARLY MORNING SHOWERS DEVELOPMENT OVER THE
EASTERN GULF OF MEXICO THAT MIGRATE TO THE COAST. TOMORROW
MORNING...THE GFS/ECMWF BOTH SHOW A MORE NW FLOW NORTH OF TAMPA BAY
AND A SW FLOW TO THE SOUTH. THIS CONVERGENT PATTERN (SHOULD IT
OCCUR) SHOULD ENHANCE THE COVERAGE OF SHOWERS APPROACHING THE
COAST...ESPECIALLY TO THE SOUTH OF TAMPA BAY. IN ADDITION...GLOBAL
GUIDANCE AGREE IN A FAVORABLE RRQ JET STRUCTURE FOR DIVERGENT FLOW
ALOFT OVER THE REGION. NOT ANTICIPATING A TUESDAY MORNING
WASHOUT...HOWEVER THOSE WITH RAIN SENSITIVE PLANS ALONG AND INSIDE
THE I-75 CORRIDOR SHOULD AT LEAST PLAN TO DODGE A FEW PASSING
SHOWERS BEGINNING FAIRLY EARLY IN THE DAY.
BY AFTERNOON...DEVELOPING SEA-BREEZE CIRCULATIONS WILL DECREASE OR
LIKELY REVERSE THE CONVERGENT PATTERN OVER THE NEAR SHORE WATERS AND
THE SECOND HALF OF THE DAY SHOULD TRANSITION TO ONE TYPICAL FOR A
WESTERLY FLOW PATTERN. THIS MEANS BEST RAIN CHANCES INLAND FROM THE
I-75 CORRIDOR OVER TOWARD THE FL EAST COAST...AND LOW RAIN CHANCES
FOR THE BEACHES OF THE FLORIDA WEST COAST.
THIS MESSY PATTERN WILL THEN BE GONE FOR THE MIDDLE OF THE WEEK AS A
TYPICAL SUMMER/AUGUST PATTERN ALOFT AND AT THE SURFACE AGAIN BECOMES
ESTABLISHED ACROSS THE REGION. HAPPY MONDAY EVERYONE!
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
UPPER LEVEL TROUGHING OVER THE EASTERN CONUS SHARPENS UP AND DEEPENS
INTO A LOW OVER/OFF THE CANADIAN MARITIMES FOR THE WEEKEND. AS THIS
OCCURS THE TROUGHING OVER THE SOUTHEAST U.S. LIFTS NORTH AND
NORTHEAST...ALLOWING AN ATLANTIC UPPER RIDGE INITIALLY ACROSS SOUTH
FL AND CUBA TO MOVE NORTH AND BUILD INTO THE GULF. AT THE SURFACE
THE NATIONAL HURRICANE CENTER HAS BERTHA WELL OFF THE NEW ENGLAND
COAST AT THE START OF THE PERIOD WHILE HIGH PRESSURE CENTERED IN
THE OPEN ATLANTIC RIDGES INTO THE GULF OF MEXICO...WITH AN AXIS
BETWEEN THE KEYS AND CUBA. THE AXIS LIFTS INTO SOUTH FL THU THEN
CENTRAL FL FRI...WHERE IT MEANDERS INTO THE WEEKEND AS A RATHER
BROAD RIDGE WITH A RELAXED GRADIENT.
THE CURRENT FORECAST PHILOSOPHY IS FOR ISOLATED TO SCATTERED...
30 TO 40 POPS...SHOWERS AND THUNDERSTORMS. THE 1000-700 MB FLOW WILL
BE LIGHT AND PREVAILING WESTERLY ALTHOUGH IT BEGINS TO BACK TO
SOUTH TO SOUTHEAST ACROSS THE SOUTH TOWARD THE END OF THE PERIOD.
THIS WILL KEEP THE ATMOSPHERE MOIST WITH PWAT VALUES IN THE 1.8 TO 2
INCH PLUS RANGE. LOW LEVEL WESTERLY FLOW ENHANCED BY SEA BREEZES IN
THE AFTERNOON WILL RESULT IN SOME MORNING SHOWERS/STORMS THAT
INCREASE INLAND DURING THE AFTERNOONS. OVERNIGHT LOWS START OFF NEAR
NORMAL BUT WARM SLIGHTLY THROUGH THE WEEK WHILE AFTERNOON HIGHS ARE
A DEGREE OR 2 ABOVE NORMAL.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE REGION EARLY THIS MORNING. OUTSIDE
OF DEVELOPING DIURNAL STORMS...THESE VFR CONDITIONS ARE EXPECTED TO
CONTINUE. WINDS WILL REMAIN LIGHT THROUGH THE DAY SHIFTING TO THE
WEST DURING THE AFTERNOON/EARLY EVENING FOR THE NEAR COASTAL
TERMINALS.
&&
.MARINE...
A WEAK AREA OF LOW PRESSURE WILL MOVE SLOWLY NORTHWARD OVER THE
FLORIDA PENINSULA TODAY AND THEN EXIT TO THE OUR NORTHEAST TONIGHT
AND TUESDAY. VARIABLE WIND FLOW TODAY IN CLOSE PROXIMITY TO THIS LOW
CENTER WILL BECOME A MORE PREDOMINANT WEST FLOW ACROSS THE EASTERN
GULF OF MEXICO FOR THE MIDDLE OF THE WEEK. HIGH PRESSURE BECOMES
FIRMLY ESTABLISHED OVER THE REGION FOR THE SECOND HALF OF THE WEEK
RESULTING IN LIGHT FLOW HIGHLIGHTED BY DEVELOPING ONSHORE FLOW EACH
AFTERNOON NEAR THE COAST.
&&
.FIRE WEATHER...
A MOIST LOW LEVEL ENVIRONMENT WILL KEEP RELATIVE HUMIDITY LEVELS WELL
ABOVE CRITICAL LEVELS THROUGH THE MIDDLE OF THE WEEK. RAIN CHANCES
WILL REMAIN HIGH THROUGH TUESDAY...ESPECIALLY OVER SOUTHERN AND
INLAND PORTIONS OF THE FORECAST AREA. SHOWERS AND STORM COVERAGE
SHOULD RETURN TO MORE NORMAL LEVELS FOR EARLY AUGUST BY THE MIDDLE
PORTION OF THE WEEK.
FOG POTENTIAL...SOME SHALLOW GROUND FOG MAY FORM OVER INLAND
LOCATIONS DURING THE EARLY MORNING HOURS THE NEXT FEW DAYS
BUT NO SIGNIFICANT VISIBILITY RESTRICTIONS ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 80 92 78 / 40 20 50 30
FMY 91 77 92 76 / 50 30 60 20
GIF 91 76 92 75 / 60 30 50 20
SRQ 91 79 90 77 / 40 30 50 30
BKV 92 74 92 72 / 40 20 50 30
SPG 91 81 91 79 / 40 30 50 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 AM EDT MON AUG 4 2014
.AVIATION...
LIGHT RAIN CONTINUES ACROSS MUCH OF THE REGION...WITH STORMS OVER
THE LOCAL WATERS. AN AREA OF LOW PRESSURE OVER THE REGION WILL
DRIFT NORTH THROUGH THE DAY...WHICH WILL IMPART A WEST SOUTHWEST
FLOW ACROSS THE REGION. THE NOCTURNAL CONVECTION WILL DISRUPT THE
DIURNAL CYCLE...AND STORMS MAY NOT REDEVELOP UNTIL LATE IN THE
DAY...IF AT ALL. HOWEVER...GUIDANCE CONTINUES TO INDICATE THE
SHOWERS AND STORMS WILL REDEVELOP ACROSS THE EAST COAST...SO KEPT
VCSH/VCTS FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 731 PM EDT SUN AUG 3 2014/
AVIATION...
CONVECTION GOT A LATE START THIS AFTERNOON DUE TO RAIN-COOLED
AIRMASS ALONG EAST COAST DELAYING ACTIVITY SO PERSISTING UNTIL
AROUND 02Z THIS EVENING AND WILL LIKELY REDEVELOP AFT 14Z MONDAY.
SURFACE WIND WILL BECOME LIGHT SW EARLY THIS EVENING WITH THE
TROUGH MOVING NORTH OF THE REGION BY LATE MONDAY. THIS WILL
PREVENT AN EAST COAST SEA BREEZE WITH NUMEROUS TSRA EXPECTED WELL
INTO THE AFTERNOON.
KOB
PREV DISCUSSION... /ISSUED 252 PM EDT SUN AUG 3 2014/
NEAR TERM...(THIS AFTERNOON)
THE HEAVY LINE OF SHOWERS/TSTMS THAT MOVED ASHORE EARLY THIS
AFTERNOON HAS WEAKENED AND DISSIPATED...MAINLY DUE TO THE MORE
STABLE EAST COAST WHERE TEMPERATURES HAVE REMAINED STEADY IN THE
LOWER 80S FROM THE EXTENSIVE CLOUD COVERAGE ASSOCIATED WITH THE
OFFSHORE CONVECTION EARLIER. FARTHER INLAND...ADDITIONAL SHOWERS
HAVE BEGUN TO DEVELOP WHERE A BETTER SOURCE OF INSTABILITY EXISTS
(TEMPERATURES HAVE ALREADY REACHED THE UPPER 80S TO 90 DEG RANGE).
THE LATEST HRRR HAS PICKED UP ON THESE TRENDS AND HAS BACKED OFF
ON THE EARLIER SUGGESTED EAST COAST ACTIVITY LATER THIS
AFTERNOON/EARLY EVENING SHOWING MOSTLY STRATIFIED PRECIP FOR THE
SE FL COAST (OR LIGHT RAIN WITH EMBEDDED HEAVIER SHOWERS/TSTMS
ALONG THE EAST COAST) THROUGH THE AFTERNOON HOURS. HOWEVER...THE
LAKE REGION INCLUDING PALM BEACH COUNTY COULD OBSERVE SOME
HEAVIER AFTERNOON SHOWERS/TSTMS.
SHORT TERM...(TONIGHT-TUESDAY NIGHT)
THE LATEST SHORT-RANGE MODEL GUIDANCE REMAINS CONSISTENT FROM CYCLE
TO CYCLE AND INDICATES THE WET PATTERN PERSISTING INTO THE UPCOMING
WEEK AS A SURFACE TROUGH OF LOW PRESSURE AND UPPER TROUGH CONTINUE
TO INFLUENCE THE LOCAL WEATHER PATTERN. AN ASCAT PASS THIS
AFTERNOON SHOWED TS BERTHA CENTERED NEAR THE SOUTHEASTERN BAHAMA
ISLANDS. THE LATEST ADVISORY INDICATES BERTHA TURNING NORTHWARD
AND REMAINING JUST EAST OF THE BAHAMAS THROUGH MONDAY AS IT PASSES
(SHOULD NOT HAVE ANY DIRECT IMPACT ON THE LOCAL AREA). THE LATEST
GUIDANCE INDICATES THE SFC TROUGH OVERHEAD THAT IS IMPACTING THE
LOCAL WEATHER SLOWLY LIFTING NWD INTO MONDAY...WHICH WILL
TRANSLATE TO SW LOW-LEVEL FLOW WITH THE RIDGE AXIS ORIENTED E-W
SOUTH OF THE AREA OVER THE STRAITS. THIS LOW-LEVEL FLOW COMBINED
WITH THE AFOREMENTIONED DEEP LAYER MOISTURE (MODEL PWAT VALUES
RANGING FROM 2- 2.3" MONDAY-TUESDAY EVENING) COULD TRANSLATE TO A
POTENTIAL HEAVY RAINFALL/FLOODING CONCERN OVER PORTIONS OF THE
LOCAL AREA PERIODICALLY...ESPECIALLY WITH THE RECENT ACTIVITY AND
THE ALREADY SATURATED GROUNDS. THE LATEST RAINFALL ACCUMULATION
PROJECTION INDICATES 1.5 TO 2.5" WIDESPREAD AMOUNTS. MUCH HIGHER
LOCALIZED AMOUNTS WHERE ANY ACTIVITY BECOMES FOCUSED FOR A PERIOD
OF TIME WILL REMAIN POSSIBLE EACH DAY. THE SURFACE FLOW IS
PROJECTED TO REMAIN LIGHT ENOUGH FOR AN EAST COAST SEA BREEZE TO
DEVELOP EACH DAY...WHICH TYPICALLY RESULTS IN THE AFTERNOON
CONVECTION SETTING UP AND FAVORING THE EAST COAST.
HOWEVER...SIMILAR TO TODAY...STABILITY COULD PLAY A ROLE HERE AND
END UP REDUCING THE OVERALL HEAVY RAIN/FLOODING CONCERNS...IF THE
OVERCAST AND RELATIVELY COOL CONDITIONS ARE REALIZED THROUGH THE
AFTERNOON PERIODS AGAIN MONDAY AND TUESDAY.
LONG TERM (WEDNESDAY-WEEKEND)...
THE LATEST EXTENDED GUIDANCE CONTINUES TO SUGGEST A RETURN OF A MORE
TYPICAL SUMMER-LIKE PATTERN ACROSS THE REGION THROUGH THE SECOND
HALF OF THE WEEK AND INTO THE WEEKEND AS A DEEP LAYER RIDGE BUILDS
BACK OVERHEAD. AT THIS TIME...IT APPEARS WEDNESDAY COULD BE THE
TRANSITION DAY...WHICH WOULD MEAN ANOTHER WET AFTERNOON WITH A
SUFFICIENT AMOUNT OF DEEP LAYER MOISTURE AND LIGHT SW LOW-LEVEL FLOW
TO FOCUS THE AFTERNOON ACTIVITY TOWARD THE EAST COAST.
AVIATION...
MOST OF THE CONVECTION HAS DISSIPATED ACROSS THE NEAR
SHORE ATLANTIC WATERS THIS AFTERNOON AFTER ENCOUNTERING A MORE
STABLE AIR MASS. ONLY AREAS OF LIGHT TO MODERATE SHOWERS REMAIN
WHICH SHOULD BE COVERED WELL WITH VCSH. LATEST HRRR KEEPS SHOWERS
ACROSS THE EAST COAST THROUGH THE EARLY EVENING WITH CONTINUED
SOUTHEAST TO SOUTHERLY WINDS. ANY REMAINING CONVECTION SHOULD STAY
ACROSS THE INTERIOR POSSIBLY AFFECTING KAPF. LEFT VCTS MENTION
THERE UNTIL 01Z.
MARINE...
TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH
FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE
TONIGHT THROUGH MONDAY. WINDS ARE FORECAST TO REMAIN LIGHT AND SHIFT
TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK. SCATTERED
SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER
CONDITIONS EACH DAY ALONG WITH REDUCED VISIBILITIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 77 92 77 / 70 40 60 30
FORT LAUDERDALE 90 80 92 80 / 70 40 50 20
MIAMI 90 79 91 79 / 70 40 50 20
NAPLES 90 76 91 77 / 50 60 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....21/KM
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
434 AM EDT MON AUG 4 2014
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE UP THE SOUTHEAST COAST ALONG A
STALLED FRONT THROUGH TUESDAY. A COLD FRONT WILL APPROACH FROM NORTH
LATE THIS WEEK AND STALL OVER OR NEAR THE AREA THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN..A WEAK AREA OF LOW PRES WAS OFF THE NE FLORIDA COAST WITH
A STALLED COASTAL TROUGH EXTENDING NE THROUGH OUR COASTAL WATERS.
DEEP MOISTURE AXIS ON LATEST RAP ANALYSIS HAS BEEN NUDGING BACK TOWARD
THE COAST OVERNIGHT WITH DEEPEST MOISTURE OFFSHORE. ALONG AND WEST
OF I-95 SKIES HAD BEEN CLEAR TO PARTLY CLOUDY BUT EXPECT MORE IN
THE WAY OF LOW CLOUDS AND PATCHY FOG TO INCREASE TOWARD DAYBREAK.
STRONG LOW LEVEL SPEED/MOISTURE CONVERGENCE BEGINNING TO SHOW WITH
INCREASING SHOWERS AND TSTMS OVER THE WATERS. CONVECTIVE RAINS WILL
LIKELY BEGIN TO IMPACT SOME COASTAL AREAS OF SE GEORGIA AND SOUTH
CAROLINA BY DAYBREAK WITH BEST TRAJECTORIES INTO THE CHARLESTON
COUNTY COAST.
FORECAST DETAILS ON THE SKETCHY SIDE TODAY ALONG AND E OF THE I-95
CORRIDOR WITH HIGHEST RAIN CHANCES COASTAL AREAS...ESPECIALLY ALONG
THE SE GEORGIA COAST THIS MORNING AND NORTH OF BEAUFORT AFTER MID
MORNING...PERHAPS INTO THE AFTERNOON HOURS. THE NAM AND MANY OF
ITS VARIANTS SUGGEST THE SURFACE WAVE WILL CLOSE OFF AND DRIFT
FURTHER NORTHWARD TODAY THAN EITHER THE GFS/ECMWF PORTRAY. THE MAIN
IMPLICATION OF THIS WOULD BE A POTENTIAL FOR MORE SIGNIFICANT AND
WIDESPREAD CONVECTIVE RAINS ACROSS THE CENTRAL SOUTH CAROLINA
COAST. GIVEN THE UNCERTAINTIES AND MOST RECENT RUNS OF NSSL WRF
AND RUC RAPID REFRESH MODELS WE WERE HESITANT ON PAINTING TOO MUCH
QPF WITH THE MAIN SYNOPTIC BOUNDARY REMAINING OFFSHORE. EVEN
SO...PWATS UP TO 2.25 INCHES SUGGEST CONVECTIVE RAINS COULD BE
LOCALLY HEAVY WITH TORRENTIAL DOWNPOURS POSSIBLE EAST OF I-95. WILL
HAVE TO WAIT AND SEE IF ANY SIGNIFICANT RAINS COINCIDE WITH A MID
AFTERNOON HIGH TIDE IN DOWNTOWN CHARLESTON...CONFIDENCE VERY LOW
ON ANY MESOSCALE DETAIL AT THIS POINT.
FAR INLAND AREAS WILL PROBABLY HAVE TO WAIT UNTIL THIS AFTERNOON
FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP AND SOME MODELS
ARE QUITE SLIM WITH COVERAGE. WARMEST TEMPS SOUTH AND INLAND
TODAY... PERHAPS A FEW LOWER 90S. CLOSER TO UPPER 80S ACROSS SOUTH
CAROLINA AND MID 80S IN PLACES SUCH AS NE CHARLESTON COUNTY.
DECREASING RAIN CHANCES TONIGHT AS A SHORT WAVE ACROSS THE TENNESSEE
VALLEY BEGINS TO NUDGE THE DEEP MOIST AXIS...LOW PRES WAVE...AND
TS BERTHA FURTHER OFFSHORE AWAY FROM THE FORECAST AREA. MAINTAINED
A FEW LINGERING SHOWERS ALONG NORTHERN COASTAL AREAS...OTHERWISE
SOME INLAND CLEARING LIKELY. LATER SHIFTS MAY NEED TO ADD SOME
PATCHY FOG PER SOME OF THE 00Z GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...MODELS CONTINUE TO INDICATE THAT A WEAK LOW PRESSURE
SYSTEM WILL SLOWLY SHIFT NORTHEAST AND AWAY FROM THE AREA THROUGHOUT
THE DAY...THUS SUGGESTING A DECREASING TREND IN SHOWER AND/OR
THUNDERSTORM COVERAGE OVER THE SOUTHEAST. EXPECT LIGHT NORTHERLY
FLOW TO BACK TO THE WEST BEHIND THE DEPARTING LOW...RESULTING IN
LESS CLOUD COVER INLAND AND WARMING TEMPS AS SFC HEATING OCCURS.
LATEST 1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE
UPPER 80S TO LOWER 90S...WARMEST INLAND. OVERNIGHT TEMPS SHOULD
RANGE BETWEEN THE LOW TO MID 70S AWAY FROM THE COAST.
WEDNESDAY AND THURSDAY...THE PATTERN APPEARS DRYER AS HIGH PRESSURE
EXTENDS OVER THE WESTERN ATLANTIC WHILE A PIEDMONT TROUGH BECOMES
ESTABLISHED INLAND. HOWEVER...A FEW SHOWERS AND/OR THUNDERSTORM CAN
NOT BE RULED OUT EACH AFTERNOON WITH ENHANCED CONVERGENCE ALONG THE
TROUGH INLAND OR SEABREEZE NEAR THE COAST. TEMPS WILL BE WARMER THAN
PREVIOUS DAYS AS A WEST/NORTHWEST DOWNSLOPE FLOW OCCURS ALOFT DURING
PEAK SFC HEATING EACH AFTERNOON UNDER PARTLY CLOUDY SKIES. LATEST
1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE LOW TO
MID 90S...WARMEST INLAND. OVERNIGHT LOWS SHOULD RANGE IN THE LOW TO
MID 70S AWAY FROM THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH EARLY THIS
WEEKEND...WITH INCREASING MOISTURE LEVELS CHARACTERIZED BY PWATS
AROUND 2.0 INCHES. CHANCES OF SHOWERS AND/OR THUNDERSTORMS SHOULD
RESULT ON FRIDAY...WITH SLIGHTLY INCREASING COVERAGE INTO THE WEEKEND
AS THE FRONT STALLS OVER OR NEAR THE AREA. DEEP MOISTURE AND
CONVECTIVE ACTIVITY ASSOCIATED WITH THE FRONT WILL LIKELY LEAD TO
MORE CLOUD COVER AND SLIGHTLY COOLER TEMPS OVER THE AREA THIS
WEEKEND INTO EARLY NEXT WEEK. IN GENERAL...OVERALL HIGH TEMPS SHOULD
RANGE IN THE LOWER 90S ON FRIDAY...BEFORE COOLING INTO THE UPPER 80S
TO AROUND 90 LATER THIS WEEKEND INTO EARLY NEXT WEEK. OVERNIGHT LOWS
SHOULD RANGE IN THE LOW TO MID 70S...COOLEST INLAND EARLY NEXT WEEK.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
KCHS...VFR INITIALIZED THIS MORNING BUT MOISTURE CONVERGENCE WAS
INCREASING AT GOOD CLIP FROM THE ATLC. MVFR CIGS POSSIBLY LATER
NIGHT WITH A FEW SHOWERS BRUSHING BY. NEARING 12Z THERE SHOULD
BE INCREASED COVERAGE IN SHOWERS AND MORE IN THE LOW OF MVFR
CIGS WITH PATCHY IFR CIGS POSSIBLE. MODELS GENERALLY AGREE WITH WET
WEATHER TODAY AS LOW PRES DEVELOPS TO THE S AND RIDES ALONG THE
COASTAL FRONT. TWO CAMPS OF MODELS CURRENTLY WITH ONE CAMP SHOWING
SCATTERED CONVECTIVE RAINS TODAY AND THE OTHER WIDESPREAD SHOWERS
AND DEFINITE TSTMS WITH HEAVY RAINS. THE NAM MODEL INDICATES IFR
CIGS WITH VERY DEEP MOISTURE AND THIS SOLUTION CANNOT BE RULED OUT
BUT IT TOO PESSIMISTIC AT THIS TIME. CONVECTIVE RAINS SHOULD BE
ON THE DECREASE THIS EVENING WITH CHANCES OF MVFR CIGS LINGERING.
KSAV...WE START THE 06Z TAFS WITH VFR WEATHER...BUT SOME
NOCTURNAL SHRA/TSRA WILL FORM NEARBY OVERNIGHT IN RESPONSE TO THE
NEARBY QUASI-STATIONARY FRONT AND APPROACHING SURFACE LOW PRESSURE
WAVE. EVEN IF ANY WET WEATHER FAILS TO MATERIALIZE THERE IS STILL
GOOD CHANCES OF FLIGHT RESTRICTIONS DUE TO THE NOCTURNAL
INVERSION...THEN A CONTINUING CAP INTO MONDAY AFTERNOON. VFR
WEATHER LOOKS TO RETURN AGAIN LATE IN THE TAF CYCLE.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS EARLY
TUESDAY AS LOW PRESSURE SHIFTS NORTHEAST OFF THE COAST. PREVAILING
VFR CONDITIONS SHOULD THEN OCCUR TUESDAY AFTERNOON THROUGH LATE
WEEK...BUT TEMPO FLIGHT RESTRICTIONS WILL REMAIN POSSIBLE EACH
AFTERNOON DUE TO SHOWERS AND/OR THUNDERSTORMS.
&&
.MARINE...
A WAVE OF LOW PRESSURE OFF THE FLORIDA COAST WILL LIFT NORTH
ALONG THE STALLED FRONT THROUGH TONIGHT. A TRICKY COASTAL WATERS
FORECAST TODAY WITH RESPECT TO GRADIENT ENHANCEMENTS AND TRACK
OF THE SURFACE WAVE. SEAS WERE ALREADY ELEVATED THIS MORNING
AND CONTINUED A SMALL CRAFT ADVISORY FOR OFFSHORE GEORGIA WATERS
THROUGH MID AFTERNOON AND IT MAY NEED A EXTENSION A LITTLE FURTHER
LATER TODAY. NEAR SHORE...MODELS DO NOT SHOW ANY SUBSTANTIAL
DEEPENING OF THE SURFACE WAVE AND EXPECT WINDS AVERAGING 15 KT
WITH THE PATTERN ONE OF CONVERGENCE INSTEAD OF JETTING. SEAS
3 TO 5 FT NEAR SHORE AND 4 TO 6 FT BEYOND 20 NM WITH MORE OF
A GROUND SWELL FROM BERTHA THAN LARGER LONG PERIOD SWELL. WINDS
WILL BEGIN TO BACK OFFSHORE OVER GEORGIA WATERS TONIGHT IN
THE WAKE OF THE LOW PASSING BY OFFSHORE.
TUESDAY THROUGH SATURDAY...SHOWERS AND THUNDERSTORMS COULD AFFECT
COASTAL WATERS INTO TUESDAY AS SFC LOW PRESSURE SHIFTS NORTHEAST AND
AWAY FROM THE AREA. CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS THIS OCCURS...WITH NORTH/NORTHEAST WINDS
EVENTUALLY BECOMING OFFSHORE AS THE SFC LOW PULLS AWAY FROM THE
AREA. HOWEVER...SWELLS ASSOCIATED WITH TROPICAL CYCLONE BERTHA WILL
AFFECT THE WATERS...WITH SEAS POSSIBLY BUILDING TO 5-6 FT OVER OUTER
GEORGIA WATERS ON TUESDAY. HIGH PRESSURE WILL THEN BUILD OVER THE
WATERS MID TO LATE WEEK WHILE A TROUGH OF LOW PRESSURE DEVELOPS
INLAND. THIS SHOULD RESULT IN SOUTH/SOUTHEAST WINDS AT OR BELOW
15 KT OVER THE WATERS...HIGHEST WITH AFTERNOON SEABREEZE
CIRCULATIONS THAT DEVELOP NEAR THE COAST. SEAS SHOULD RANGE BETWEEN
1-3 FT. SHOWER AND/OR THUNDERSTORM COVERAGE WILL LIKELY INCREASE LATER
THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTH AND STALLS
OVER OR NEAR THE AREA.
RIP CURRENTS...BORDERLINE RISK FOR MODERATE TODAY WITH ONGOING
SEAS A BIT HIGHER THAN ANTICIPATED. GROUND SWELL FROM TS BERTHA
ENOUGH TO FORECAST A MODERATE RISK TODAY TO BE ON THE SAFE SIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ374.
&&
$$
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 AM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO EAST-NORTHEAST THIS AFTERNOON WITH COMBINATION OF
LAKE BREEZE/COLD FRONT.
* SCATTERED SHRA/TSRA FROM MID-DAY THROUGH THIS EVE.
RATZER
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE REMAINS ACROSS AREA EARLY THIS MORNING WITH WEAK
GRADIENT AND CONTINUED LIGHT/CALM WINDS. LIGHT WIND FIELD WILL
LIKELY AGAIN ALLOW LAKE BREEZE DEVELOPMENT BY AFTERNOON...WHICH
MAY COMBINE WITH A WEAK COLD FRONT MOVING SOUTH ACROSS WI/LAKE
MICHIGAN DURING THE DAY. TIMING OF WIND SHIFT TO EAST-NORTHEAST
BEHIND THIS BOUNDARY REMAINS QUESTIONABLE WITH VARYING MODEL
SOLUTIONS...BUT IT APPEARS WIND SHIFT SHOULD BE WORKING INTO FAR
NORTHEAST IL DURING EARLY AFTERNOON WITH WEAKENING WEST-SOUTHWEST
BOUNDARY FLOW ALLOWING IT TO PUSH ACROSS TERMINALS DURING THE
AFTERNOON. LIGHT EAST-NORTHEAST WINDS LIKELY TO PERSIST TONIGHT AS
FRONT SAGS SOUTH OF TERMINALS.
SHRA/TSRA...SEVERAL SMALL DISTURBANCES IN MID-LEVEL FLOW UPSTREAM
OF THE AREA EARLY THIS MORNING. COMBINED WITH WEAK DESTABILIZATION
NOTED IN FORECAST SOUNDINGS BY LATE MORNING/MIDDAY...SOME
POTENTIAL OF ISOLATED SHRA/TSRA WILL LIKELY EXIST PRIOR TO NOON.
GREATER THREAT WILL LIKELY BE TIED TO DIURNAL INSTABILITY PEAK
DURING THE AFTERNOON AND EARLY EVENING HOURS...AND LOW LEVEL
FORCING PROVIDED BY THE COLD FRONT/LAKE BREEZE BOUNDARIES. SOME
POTENTIAL MAY LINGER INTO TONIGHT AS MID-LEVEL TROUGH CONTINUES TO
DRIFT SOUTHEAST ACROSS AREA. OVERALL HAVE MOVED TIMING OF TSRA A
BIT SOONER THAN PREVIOUS FORECAST.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW IN LAKE BREEZE AND COLD FRONTAL WIND SHIFT TIMING AND SPEED
BEHIND IT THIS AFTERNOON.
* MEDIUM IN SCATTERED SHRA/TSRA DEVELOPING AS EARLY AS MIDDAY AND
CONTINUING INOT THIS EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
MTF
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENEARLLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
253 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
Barnes
&&
.AVIATION...
ISSUED 1139 PM CDT Sun Aug 3 2014
Light fog is beginning to become more widespread in eastern
Illinois as far west as KDEC, which earlier briefly dipped to as
low as 1-1/2SM courtesy of the isolated showers from earlier.
Think that over the next 1-2 hours, MVFR visibilities should be
affecting all the TAF sites, with potential for some IFR
conditions again at KDEC. This should quickly lift Monday morning.
Focus beyond that is with an incoming cold front, which has the
potential for scattered storms by late afternoon near KPIA. Model
agreement has been mixed on how far east this boundary will make
it, and will hold off introduction at the other TAF sites for now,
although it would be most likely after 00Z if it did occur. Should
see scattered to broken clouds for most of the period after
sunrise, but likely to be at or above 7,000 feet based on forecast
soundings.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
345 AM CDT Mon Aug 4 2014
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT MON AUG 4 2014
Weak mid level trough shifting southeast across northern MO this
morning with another shortwave trough noted over SD. A few isolated
showers have developed over far eastern KS this morning with weak
isentropic ascent in the presence of a 35 kt LLJ. While the HRRR is
overdone on coverage of showers, the ARW and NMM high-res guidance
is also picking up on a few isolated showers continuing through mid
morning. Will leave a slight chance mention through this time, but
confidence is low for measurable precipitation.
Showers over SD are progged to dissipate over NE while the upper
ridge to our west shifts east into the area today and tonight. At the
surface, the trough axis shifts southward, pushing a weak boundary
near the Interstate 70 corridor by afternoon. Strength of
convergence on the boundary varies by the model with the 06Z NAM
being the outlier and most progressive with mid 60 dewpoints creating
a more unstable and weakly capped boundary layer during peak
heating. All other short and mid term guidance points to weak
forcing on the boundary, subsidence aloft while mid-level ascent is
displaced further east. With some near sfc convergence along the
boundary, cannot completely rule out an isolated storm and will hold
onto slight chances for thunderstorms this afternoon through early
evening. Any storm that is able to develop may produce gusty winds.
850 mb thermal ridge axis spreads east during the day just above
20C, rising highs into the lower and middle 90s. Another upper
trough passes over Iowa and MO tonight, increasing scattered mid
level clouds and lows in the low 70s.
.LONG TERM...(Tuesday through Sunday)
Issued at 321 AM CDT MON AUG 4 2014
The long term period is rather unsettled with a consistent train
of weak disturbances (and a few more organized ones) crossing the
central plains through the coming week.
Tuesday looks to have the best chance of the coming week to be dry
as the local area should be in between weak disturbances and the
low levels should be somewhat dried out...limiting instability.
That said, it should also be the hottest day of the next week with
slight ridging overhead and likelihood of quite a bit of sunshine.
Expect highs from the lower 90s far northeast to the upper 90s in
north central KS.
By late Tuesday night, the short wave currently in the Las Vegas
area should move out across Nebraska along a stationary front just
north of the KS/NE border, and seems likely to support a broad
area of thunderstorm activity/MCS. The bulk of the storms Tuesday
night are likely to stay north of the forecast area but could get
a few storms to develop/move in after midnight. By Wednesday, the
front will move south into the area as a northern stream trough
dives into the Great Lakes and brings a cooler airmass south. The
frontal progression along with additional short waves moving
across the Plains from the southwest will provide a favorable
setup for one or more convective complexes to impact the forecast
area Wednesday afternoon through Thursday morning with additional
development on Thursday afternoon. Moderate instability and weak
shear through this period should mitigate the severe potential,
but locally heavy rainfall/flooding may become an issue depending
how these convective complexes evolve. Dry antecedent soil
conditions will mitigate the flood threat a bit, but still seems
possible if a backbuilding situation sets up.
Thunderstorm chances continue through the remainder of the
forecast period but confidence in the details of timing and
magnitude is not high. Expect days with moderate to strong
instability but wind shear looks to remain marginally adequate for
organized storms. Thunderstorm chances will also depend at least
somewhat on how far the front moves south of the area as a
drier airmass may try to push in from the northeast if the front
moves far enough south.
Temperatures will cool a bit after the Wednesday frontal passage
and highs should be a bit below normal in the mid to upper 80s for
the Thursday through Sunday time frame with lows in the middle to
upper 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1149 PM CDT SUN AUG 3 2014
VFR conditions still anticipated. Chances for elevated convection
continue to wane but are not nil for at least the next few hours.
SW winds should pick up with mixing of the 25-30kt low level jet
per area radar winds. Winds weaken around 0Z as a low level trough
nears.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Barjenbruch
AVIATION...65
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT Mon Aug 4 2014
...Update to aviation...
.SHORT TERM...(This evening through Monday)
ISSUED AT 333 PM CDT SUN AUG 3 2014
This mornings convective allowing models allowed some room for
convection to develop once again just north of the I-70 corridor and
be driven southeast by the man flow, much like last evening. So far
this afternoon the area of enhanced cu development across northwest
Kansas has not shown signs of stronger shower or storm development
although the GLD 88D was indicating rain in the HCA. We will
continue to carry less than 20 PoPs trough the end of the afternoon
and early evening to see how this evolves, especially given the
increasingly robust HRRR model drives a few storms into Rush and
Stafford counties.
For the rest of the period including tonight into tomorrow, we
followed the NAM and Raw Model Blend which seemed to do the best job
collectively with temperatures and surface winds for yesterday.
little overall change in airmass will take place with the upper
ridge settling slightly farther east.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 350 PM CDT SUN AUG 3 2014
Drier conditions will persist across western Kansas through early
Tuesday afternoon as an upper level ridge axis shifts eastward across
the Western High Plains. Medium range models then indicate the ridge
breaking down late Tuesday as a series of H5 vort maxima associated
with a shortwave eject out of the Rockies into the high plains of
western Nebraska and western Kansas. A developing lee side trough
will strengthen as the shortwave approaches while low/mid level
moisture continues to pool slowly across central and portions of
western Kansas. This will set the stage for possible thunderstorm
development across portions of southwest and central Kansas Tuesday
evening into Wednesday. Although low/mid level lapse rates will
steepen through the afternoon period Tuesday, NAM/GFS model
soundings show very little instability in regards to available CAPE
with values well under 100 J/KG. This will likely hinder storm
development through much of the afternoon with chances increasing
Tuesday evening as CAPE begins to rise. Although less than
favorable, a slightly strengthened flow aloft along with decent
directional shear may be enough to support stronger thunderstorms
with gusty winds the primary threat.
Precip chances will shift eastward across western into central
Kansas Wednesday as the surface trough migrates through.
Thunderstorms will be possible again into Thursday as H5 vort
maxima continue to move out of the Rockies into the Western High
Plains. However, better chances will be more to the north across
west central and central Kansas in association with the stronger
flow. Seasonal temperatures will continue through Thursday as a
south to southeasterly flow prevails through much of the period.
This will reinforce the warm air mass already in place across
western Kansas keeping highs up into the 90s(F) each day through
the end of the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1200 AM CDT MON AUG 4 2014
VFR expected through TAF pd. Southerly winds will increase 12-18 kt
with gusts 20-25 kt by 18Z and through much of the afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 92 69 94 / 0 0 0 10
GCK 63 92 68 94 / 0 0 0 20
EHA 64 91 67 95 / 0 0 0 10
LBL 65 93 69 96 / 0 0 0 20
HYS 67 95 70 93 / 20 0 0 10
P28 66 93 69 94 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...JJohnson
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
506 AM EDT MON AUG 4 2014
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 505 AM EDT MON AUG 4 2014
THERE IS A CLUSTER OF THUNDERSTORMS OVER SOUTHERN LAKE MICHIGAN
FROM WEST OF GLENN TO JUST NORTH OF BERRIEN COUNTY OFF SHORE. THE
STORMS HAVE MOVED INLAND TOO OVER EXTREME SOUTHWEST ALLEGAN AND
WESTERN VAN BUREN COUNTY. THESE STORMS ARE ASSOCIATED WITH A MESO-
LOW OVER SOUTHERN LAKE MICHIGAN. THE MIXED LAYER CAPE IS UNDER 250
J/KG AND THE MOST UNSTABLE CAPE NEAR 500 J/KG BUT NEARLY ALL OF
THAT IS ONLY OVER LAKE MICHIGAN. I WOULD EXPECT THE STORMS TO
CONTINUE TO DEVELOP OVER SOUTHEAST LAKE MICHIGAN UNTIL THE SUN
RISES ENOUGH TO MIX THE AIR. THIS IS SHOWN BY THE RAP MODEL WHICH
CONTINUES THE STORMS TILL AROUND 8-9 AM.
&&
.SYNOPSIS...
ISSUED AT 328 AM EDT MON AUG 4 2014
EXPECT SCATTERED THUNDERSTORMS TODAY INTO TONIGHT AS A WEAK
COLD FRONT MOVES SLOWLY SOUTH THROUGH THE AREA. TODAY WILL BE THE
LAST REALLY WARM DAY FOR WHILE. HIGH SHOULD REACH THE MID 80S IN
LAND AREAS. SOME LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TUESDAY THANKS TO AN UPPER LEVEL DISTURBANCE. BEYOND THAT COOLER
THAN NORMAL TEMPERATURES AND DRY WEATHER IS EXPECTED MOST OF THE
REST OF THE WEEK. A SLOW WARMING TREND STARTS FRIDAY AND CONTINUES
THROUGH SUNDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 328 AM EDT MON AUG 4 2014
THE PRIMARY ISSUE AS I SEE IT IS THE THREAT FOR THUNDERSTORMS
TODAY INTO TUESDAY MORNING. ANOTHER ISSUE IS JUST HOW WARM IT WILL
GET TODAY.
THERE IS A WEAK COLD FRONT SLOWLY MOVING SOUTH THROUGH THE STATE
OF MICHIGAN AS I WRITE THIS. THE PROBLEM THROUGH IS THERE IS NOT A
LOT OF PUSH BEHIND THE INITIAL COLD FRONT AND THE TEMPERATURE
GRADIENT BEHIND THE FRONT IS WEAK. MOSTLY DUE TO THE LACK OF ANY
SIGNIFICANT LOW LEVEL JET OR DECENT UPPER LEVEL JET. THAT DOES
CHANGE TONIGHT AS EXIT REGION OF A 85 KNOT JET CORE MOVES INTO THE
AREA. THAT THEN ALLOWS A BETTER PUSH OF THE COLD AIR SOUTH AND
CREATES A SORT OF SECONDARY FRONTAL BOUNDARY THAT TURNS SURFACE
WINDS TO THE NORTHEAST TONIGHT.
THERE IS AROUND 2000 J/KG OF MIXED LAYER CAPE INLAND OF US-131
THIS AFTERNOON SO EVEN WITH WEAK SURFACE CONVERGENCE I WOULD
EXPECT SOME THUNDERSTORMS. WITH A DECENT AMOUNT OF CAPE IN THE -10
TO -30 TEMP RANGE SOME STORMS COULD HAVE HAIL WITH THEM.
TONIGHT EXIT REGION DYNAMICS WILL AID CONVECTIVE DEVELOPMENT AND
THAT WILL CONTINUE INTO MIDDAY TUESDAY. BEYOND THAT HIGH PRESSURE
RULES AND IT WILL BE COOLER TOO.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 AM EDT MON AUG 4 2014
THE MID RANGE MODELS ARE TENDING TOWARD A DRIER LONG TERM FORECAST
AND CONFIDENCE IS INCREASING. NO PRECIPITATION IN THE GRIDS... AS
RIDGING AND SURFACE HIGH PRESSURE TO COVER THE REGION.
TEMPERATURES WILL BE AROUND TO A LITTLE BELOW NORMAL FOR THE END OF
THE WORK WEEK AND SLOWLY WARM TO A LITTLE ABOVE NORMAL FOR THE
WEEKEND. NORMAL HIGHS ARE AROUND 80 DEGREES AND NORMAL LOWS ARE
AROUND 60 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1157 PM EDT SUN AUG 3 2014
LIGHT MVFR FOG/HAZE IS EXPECTED AGAIN OVERNIGHT AND EARLY
MONDAY... FROM ROUGHLY 09Z TO 14Z. VSBYS SHOULD BE MOSTLY 3-5
MILES BUT SOME IFR VSBYS UNDER 3 MILES CANNOT BE RULED OUT.
WIDELY SCATTERED SHOWERS AND TSTMS ARE EXPECTED MONDAY AFTERNOON
WITH THE EXCEPTION OF THE LK MI SHORELINE. WILL CARRY VCTS AFTER
18Z IN MOST OF THE TAFS ALTHOUGH LEFT THUNDER OUT OF THE TAF FOR
MKG DUE TO THE STABILIZING EFFECTS OF LK MI.
DIURNAL CONVECTION SHOULD WEAKEN MONDAY EVENING AFTER 01Z ALTHOUGH
SCATTERED SHOWERS MAY CONTINUE THROUGH MONDAY NIGHT AS SLOW MOVING
SFC FRONT SAGS SOUTH THROUGH SRN LWR MI.
&&
.MARINE...
ISSUED AT 328 AM EDT MON AUG 4 2014
THERE IS THE THREAT FOR THUNDERSTORMS TODAY INTO TUESDAY MORNING
BUT IT WOULD SEEM THE GREATEST CONCENTRATION OF THUNDERSTORMS
SHOULD BE WELL INLAND OF THE LAKE SHORE. STILL A FRONT IS A FRONT
SO THUNDERSTORMS ARE POSSIBLE EVEN SO TODAY INTO MID MORNING TUESDAY.
WINDS SHOULD BE FAIRLY LIGHT TODAY INTO TONIGHT AS THE FRONT
SLOWLY MOVES THROUGH THE AREA SO NO ISSUES WITH HIGH WINDS OR
WAVES. ON TUESDAY BEHIND THE COLD FRONT WINDS TO INCREASE A TOUCH
FROM THE NORTH BUT FOR THE MOST PART SHOULD STAY 1O KNOTS OR LESS
SO WE SHOULD STILL NOT HAVE ISSUES WITH LARGE WAVES OR SWIMMING
HAZARDS.
&&
.HYDROLOGY...
ISSUED AT 302 PM EDT SUN AUG 3 2014
NO HYDRO ISSUES EXPECTED OVER THE NEXT WEEK. THERE IS A POTENTIAL
FOR LOCALLY HEAVY RAIN IN THUNDERSTORMS MAINLY MIDDAY MONDAY THROUGH
EARLY TUESDAY MORNING. AFTER A COLD FRONT MOVES THROUGH EARLY
TUESDAY... DRY WEATHER IS EXPECTED THROUGH THE REST OF THE WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
MESOSCALE...WDM
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...63
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...WDM
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
308 AM CDT Mon Aug 4 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 307 AM CDT Mon Aug 4 2014
Precip chances continue to be the primary forecast challenge in the
short range. Scattered thunderstorms are once again moving over
parts of northwest and west central Missouri this morning. RAP
shows an area of weak moisture convergence at 850mb which closely
conforms to the activity on radar at this time; so will go under the
assumption that this is what`s forcing the convection. The moisture
convergence continues basically over the same region through 12Z
before slowly weakening according to the RAP. Most operational
models tend to agree with the RAP and keep the vast majority of the
CWFA dry today. However, the NAM has other ideas and spreads this
moisture convergence eastward across much of Missouri into west
central Illinois by 00Z. This looks like it may be in response to
the subtle shortwave currently diving southeast along the South
Dakota/Nebraska/Iowa borders. NCEP and NSSL 4km WRFs both break out
convection over the area, which more closely supports the NAM
solution today. Further, the NAM and NCEP WRF handled yesterday`s
precip over central Missouri much better than the other models, so I
have more confidence in them than the rest of the suite. Have
therefore bumped up PoPs to mid-chance across much of central and
northeast Missouri into west central Illinois today, fading to low
chance/slight chance further to the southeast. Persistence highs
from 85-90 still look good for today.
Carney
.LONG TERM: (Monday through Next Sunday)
Issued at 343 PM CDT Sun Aug 3 2014
(Monday - Tuesday)
Area of showers and storms from overnight convection is possible to linger
through the morning hours over northern and western portions of
the forecast area. If such an area exists early tomorrow
morning...it should slide south and east with the mid to upper-
level flow pattern. Isolated to scattered convection is possible
tomorrow afternoon as the ams destabilizes across the
area...especially across northern sections of the forecast area in
close proximity to warm frontal boundary/wind shift and area of
diffluence aloft. A few of these storms may be strong due to the
degree of instability forecast...however any kind of organized
strong storms looks unlikely due to very weak deep layer shear
(aob 25 knots).
Frontal boundary is expected to sag south a bit on Monday night and Tuesday
along with the continued chances of showers and thunderstorms. Lows Monday
night look to be near seasonal norms or slightly warmer than the previous
nights due to increased cloud cover and southerly flow across portions of
the area.
(Wednesday - Sunday)
Unfortunately...still plenty of uncertainty regarding PoPs and effects on
temperatures for the rest of the extended period. GFS/CMC are now much
further north with MCS progged for Wednesday compared to more consistent
ECMWF. Did not make too many changes Wednesday on compared to previous
forecast as GFS/CMC do look too far north and east with convection not only
on Wednesday but also through the work week looking at mid/upper level flow
pattern and NW-SE oriented baroclinic zone. Highest threat of rainfall still
looks to be somewhere in the Wednesday night through early Saturday time frame
but bountiful uncertainity/disagreement in track/timing on indiviudal
shortwaves precludes pin pointing any time period(s) with much higher PoPs
than previously forecast. Still does look like a wet and active pattern
for the mid/upper Mississippi Valley...just a matter of exactly where and
when.
Temperatures for the valid period look to be slightly below normal...mainly
due to daytime highs being cooler than normal because of clouds and rain
chances.
Gosselin
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1140 PM CDT Sun Aug 3 2014
Ongoing TSRA over nwrn MO shud move ewd very slowly tonight. These
storms shud remain N of COU based on latest guidance and trends.
However, uncertainty remains how far S the storms will develop.
The remnants of these storms shud provide a focus for
development in the UIN region Mon afternoon, but timing remains
uncertain. SUS is expected to see FG during the pre-dawn hrs once
again. Otherwise, SUS/CPS are expected to remain VFR and dry,
although can not rule out TSRA development during Mon afternoon in
the region. Winds are expected to remain sely to sswly aob 10 kts
thru the period.
Specifics for KSTL: VFR and dry thru the period with sely to sswly
winds aob 10 kts. TSRA may develop in the region Mon afternoon but
too much uncertainty exists attm.
Tilly
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 90 70 91 72 / 20 30 30 20
Quincy 86 65 86 67 / 40 40 20 30
Columbia 88 66 90 69 / 40 30 20 10
Jefferson City 89 67 90 69 / 30 30 20 10
Salem 86 65 89 67 / 10 20 30 20
Farmington 88 64 89 67 / 20 20 30 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1146 PM CDT Sun Aug 3 2014
.UPDATE:
Issued at 926 PM CDT Sun Aug 3 2014
Isolated thunderstorms have recently developed over western
Missouri in an area of 925-850mb moisture convergence. RAP shows
this area of forcing will spread eastward into central and
northeast Missouri after midnight. Going forecast handles this
trend well, so will keep chance of thunderstorms going in these
areas with slight chances all the way east to the St. Louis metro
area. Temperature and sky trends also match going forecast.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 343 PM CDT Sun Aug 3 2014
The primary forecast issue for late this afternoon through the
overnight hours is convective trends. Ongoing isolated to scattered
SHRA/TSRA along an outflow boundary will probably keep percolating
late this afternoon in central MO, then diminish tonight with the
loss of daytime heating. Meanwhile, a vort max will dive south out
of the Dakotas, providing a source of lift for new development later
tonight. The 12z model runs did not seem to accurately capture the
strength of the vort max based on its presentation on today`s water
vapor imagery. The western edge of the aforementioned outflow
boundary was very pronounced on afternoon visible satellite imagery,
and initial thoughts are that scattered SHRA/TSRA could develop late
tonight in eastern KS or western/central MO due to lift over this
boundary occurring ahead of the approaching short wave from its weak
westerly LLJ. Limited moisture would tend to limit the coverage of
any precip which develops. Overnight lows should be similar to last
night in most locations, except a bit warmer due to increased
mid/high clouds after 06z which will interfere with radiational
cooling processes.
Kanofsky
.LONG TERM: (Monday through Next Sunday)
Issued at 343 PM CDT Sun Aug 3 2014
(Monday - Tuesday)
Area of showers and storms from overnight convection is possible to linger
through the morning hours over northern and western portions of
the forecast area. If such an area exists early tomorrow
morning...it should slide south and east with the mid to upper-
level flow pattern. Isolated to scattered convection is possible
tomorrow afternoon as the ams destabilizes across the
area...especially across northern sections of the forecast area in
close proximity to warm frontal boundary/wind shift and area of
diffluence aloft. A few of these storms may be strong due to the
degree of instability forecast...however any kind of organized
strong storms looks unlikely due to very weak deep layer shear
(aob 25 knots).
Frontal boundary is expected to sag south a bit on Monday night and Tuesday
along with the continued chances of showers and thunderstorms. Lows Monday
night look to be near seasonal norms or slightly warmer than the previous
nights due to increased cloud cover and southerly flow across portions of
the area.
(Wednesday - Sunday)
Unfortunately...still plenty of uncertainty regarding PoPs and effects on
temperatures for the rest of the extended period. GFS/CMC are now much
further north with MCS progged for Wednesday compared to more consistent
ECMWF. Did not make too many changes Wednesday on compared to previous
forecast as GFS/CMC do look too far north and east with convection not only
on Wednesday but also through the work week looking at mid/upper level flow
pattern and NW-SE oriented baroclinic zone. Highest threat of rainfall still
looks to be somewhere in the Wednesday night through early Saturday time frame
but bountiful uncertainity/disagreement in track/timing on indiviudal
shortwaves precludes pin pointing any time period(s) with much higher PoPs
than previously forecast. Still does look like a wet and active pattern
for the mid/upper Mississippi Valley...just a matter of exactly where and
when.
Temperatures for the valid period look to be slightly below normal...mainly
due to daytime highs being cooler than normal because of clouds and rain
chances.
Gosselin
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1140 PM CDT Sun Aug 3 2014
Ongoing TSRA over nwrn MO shud move ewd very slowly tonight. These
storms shud remain N of COU based on latest guidance and trends.
However, uncertainty remains how far S the storms will develop.
The remnants of these storms shud provide a focus for
development in the UIN region Mon afternoon, but timing remains
uncertain. SUS is expected to see FG during the pre-dawn hrs once
again. Otherwise, SUS/CPS are expected to remain VFR and dry,
although can not rule out TSRA development during Mon afternoon in
the region. Winds are expected to remain sely to sswly aob 10 kts
thru the period.
Specifics for KSTL: VFR and dry thru the period with sely to sswly
winds aob 10 kts. TSRA may develop in the region Mon afternoon but
too much uncertainty exists attm.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1040 PM MDT Sun Aug 3 2014
UPDATED AVIATION SECTION
.DISCUSSION...
Update forthcoming. Thunderstorm activity continues to decrease.
Currently, the strongest storms are moving across eastern Fergus and
southern Blaine counties and should clear the area by midnight.
Additionally, showers are moving through southern Beaverhead County
at this time. Radar returns indicate isolated activity occurring
across southern Alberta and RUC analysis develops some qpf along the
International Boundary and the Hi-Line overnight. So have kept low
POPs there as well as along the Rocky Mountain Front and over
portions of southwest Montana. Monday looks to be another replay of
today. Overnight temperatures look good.
&&
.AVIATION...
UPDATED 0440Z.
Southwest flow aloft will continue to bring moisture to southwest
Montana. The airmass will become unstable again after 18z with
scattered showers and thunderstorms developing over the southwest
and then spreading north and east. Convective activity will continue
beyond 00z. VFR conditions prevail with MVFR conditions possible in
the vicinity of showers and/or thunderstorms along with erratic and
gusty winds.
&&
.PREV DISCUSSION...Issued 246 PM MDT Sun Aug 3 2014
Tonight through Tuesday...Short term forecast period continues to
be dominated by an upper level ridge over the western USA. As a
result, very little change is expected in the day to day forecast.
Very warm temperatures are expected each afternoon with winds
remaining generally light. Afternoon and evening thunderstorms are
expected each day...with isolated to scattered convection continuing
through the overnight and morning hours. Southwest Montana should
see the bulk of convection each day with numerous thunderstorms
expected Monday and Tuesday evening. Locally heavy rain, small
hail, gusty winds and occasional lightning strikes are expected to be
the main threats with any storms that develop. mpj
Tuesday Night through Sunday...A repeat of the current pattern
continues through the long term. Warm temperatures and isolated to
scattered thunderstorms will develop each afternoon, generally
starting up over terrain. With the showery nature of monsoonal
moisture, uncertainty remains with precipitation amounts and
coverage. Areas near higher terrain have the best chance of seeing
precipitation, namely the Continental Divide and Southwest
Montana. Latest model runs suggest a stronger push of moisture in
the Tue/Wed into Thu time frame. GFS brings in moisture over
Southwest Montana by Tue whereas the ECM holds it off until Wed.
There are also differences with placement as the ECM keeps
moisture a little more confined to the southwest. Did not jump on
either direction and went more in the middle of the two models.
Flow may become more westerly by the end of next week as high
pressure retreats southward a little bit. Not much in the way of
weather is expected though.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 58 86 59 84 / 10 20 40 30
CTB 53 83 54 82 / 20 20 30 30
HLN 58 87 59 86 / 10 30 40 40
BZN 55 85 56 83 / 10 40 40 50
WEY 50 73 48 70 / 10 50 50 60
DLN 55 80 54 80 / 20 40 40 50
HVR 58 88 61 86 / 20 10 30 30
LWT 57 85 59 80 / 20 20 40 40
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
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AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1236 AM CDT MON AUG 4 2014
.SYNOPSIS...
ISSUED AT 345 PM CDT SUN AUG 3 2014
AT 19Z WATER VAPOR IMAGERY SHOWS THE CONTINUED WESTERN RIDGE/EASTERN
TROUGH PATTERN ONGOING. HOWEVER THERE IS A POTENT UPPER LEVEL LOW
MOVING INTO SOUTHERN CALIFORNIA ON THE WESTERN SIDE OF THE RIDGE.
ACROSS CANADA...COULD SEE A FEW NOTABLE SHORTWAVE TROUGHS...THE
FIRST OVER NORTHERN SASKATCHEWAN AND THE SECOND OVER SOUTHERN
BRITISH COLUMBIA. OTHER WEAK DISTURBANCES COULD ALSO BE SEEN
ROUNDING THE RIDGE AND MOVING THROUGH NORTHWEST FLOW INTO THE
CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOCALLY...A WEAK
SURFACE BOUNDARY WAS SEEN FROM NORTHWEST NEBRASKA ARCING DOWN INTO
SOUTH CENTRAL NEBRASKA...ROUGHLY FROM KCDR TO KLBF TO KGRI.
TEMPERATURES HAD REACHED THE UPPER 80S AND LOW 90S MOST
PLACES...WHICH WERE AT OR NEAR FULL MIXING POTENTIAL. STARTING TO
SEE SOME CUMULUS POP UP ACROSS THE AREA...WHILE AREAL COVERAGE IS
LOW DUE TO A LACK OF MID LEVEL MOISTURE.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN AUG 3 2014
ANY SHOWERS OR STORMS THAT DEVELOP ACROSS THE FORECAST AREA THIS
AFTERNOON DUE TO THE FAVORABLE LOW AND MID LEVEL CONDITIONS FOR GOOD
SB INSTABILITY WITH THE STEEP LOW AND MID LEVEL LAPSE RATES SHOULD
BE FAIRLY SHORT LIVED AND EXPECT ANY ACTIVITY TO END EARLY THIS
EVENING WITH THE LOSS OF DAYTIME HEATING AND STABILIZATION OF THE
BOUNDARY LAYER AS THERE WILL NOT BE SUPPORT ALOFT TO SUSTAIN ANY OF
THIS ACTIVITY.
ALTHOUGH IT IS DIFFICULT TO PICK OUT IN WATER VAPOR IMAGERY...MODELS
INDICATE A WEAK SHORTWAVE TROUGH OVER SOUTHERN MONTANA
CURRENTLY...WITH ANOTHER WEAK DISTURBANCE OVER WESTERN SOUTH DAKOTA.
THE SD SHORTWAVE MAY BRING ENOUGH LIFT TO BRING SOME SCATTERED
SHOWERS AND THUNDERSTORMS INTO NORTHWEST NEBRASKA THIS EVENING.
CONFIDENCE IS NOT HIGH IN THIS OCCURRING AS MOISTURE IS FAIRLY
LIMITED...BUT THE HRRR AND RAP HAVE BEEN CONSISTENTLY SIGNALING SOME
STRONGER CONVERGENCE AND LIFT IN THIS AREA SO WILL INCLUDE A SLIGHT
CHANCE IN THIS EVENING OVER THE NORTHWEST CORNER OF THE FORECAST
AREA. THEN OVERNIGHT...THE SHORTWAVE TROUGH OVER MONTANA WILL MAKE
ITS WAY INTO NORTH CENTRAL NEBRASKA. AS HAS BEEN OCCURRING FOR
SEVERAL DAYS...TEMPERATURES ARE COOL ENOUGH IN THE MID LEVELS TO
KEEP LAPSE RATES VERY STEEP AND EVEN SLIGHT LIFT FROM WEAK
SHORTWAVES SEEMS TO BE ENOUGH TO ALLOW STORMS TO DEVELOP
NOCTURNALLY. ALTHOUGH THERE IS QUESTION TO IF THERE WILL BE ENOUGH
MOISTURE TO WORK WITH...AND EXACTLY WHERE THE CHANCES WILL BE BEST
THE CURRENT THOUGHTS ARE THAT ACTIVITY WILL PASS ACROSS THE
NORTHEAST PART OF THE FORECAST AREA...ROUGHLY EAST OF A VALENTINE TO
TAYLOR LINE. THIS ENDS EARLY MONDAY MORNING.
THE UPPER LEVEL PATTERN DOES BEGIN TO SEE A SHIFT THROUGH THE DAY
MONDAY. THE UPPER LOW OVER CALIFORNIA WILL MOVE INTO THE RIDGE WHICH
WILL CAUSE THE RIDGE TO START SHIFTING EAST. MEANWHILE...THE
SHORTWAVE OVER SASKATCHEWAN WILL DIVE INTO THE GREAT LAKES REGION TO
PUSH A COLD FRONT THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND
APPROACH NORTHEAST NEBRASKA BY THE END OF THE DAY. ALSO...THE
BRITISH COLUMBIA SHORTWAVE WILL START SLOW EASTERLY MOVEMENT WHICH
WILL PLAY THE PART OF FLATTENING THE RIDGE. THIS MOVEMENT IN THE
UPPER LEVELS WILL LEAD TO LOW PRESSURE DEVELOPING OVER THE LEE SIDE
OF THE ROCKIES TONIGHT AND MONDAY...WITH WINDS IN TURN SWITCHING
AROUND TO THE SOUTH BY MONDAY MORNING. EXPECTING THE WINDS TO
INCREASE THROUGH THE DAY AS THE PRESSURE GRADIENT TIGHTENS. AS THE
RIDGE SHIFTS EAST...TEMPERATURES ALOFT WILL WARM ON MONDAY. CURRENT
700MB TEMPERATURES IN THE UPPER SINGLE DIGITS LOOK TO INCREASE TO
11-13C BY 00Z TUESDAY SO SHOULD HAVE THE POTENTIAL FOR A SLIGHTLY
WARMER DAY FOR MOST LOCATIONS FOR MONDAY WITH FORECAST HIGHS FROM
AROUND 90 TO THE MID 90S NORTHEAST TO SOUTHWEST.
MAINTAINED THE SLIGHT CHANCES FOR SHOWERS AND STORMS ACROSS THE
NORTH AND WEST MONDAY AFTERNOON. A SHORTWAVE MOVES TOWARDS NEBRASKA
IN THE AFTERNOON OUT OF WYOMING AND COLORADO...HOWEVER THE TIMING
LOOKS BETTER WITH THIS INTO THE EVENING. THE MODELS DO CONTINUE TO
DEVELOP PRECIPITATION OVER NORTHERN NEBRASKA IN THE AFTERNOON AS
MOISTURE POOLS ALONG A BOUNDARY IN THE VICINITY OF THE NE/SD BORDER.
DEWPOINTS RISE INTO THE UPPER 50S AND 60S AT THE SURFACE AND MID
LEVEL MOISTURE INCREASES...AND WITH LOW LEVEL LAPSE RATES STAYING
STEEP...PRECIPITATION CONTINUES TO LOOK POSSIBLE. INSTABILITY ISN/T
GREAT...WITH MU VALUES BEING UP TO 1000 J/KG...BUT DEEP LAYER SHEAR
WILL BE INCREASING SO COULD GET A FEW CELLS TO ORGANIZE IN THESE
AREAS TO GET A FEW STRONGER STORMS. WIDESPREAD SEVERE WEATHER IS NOT
ANTICIPATED.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN AUG 3 2014
A PATTERN SHIFT WILL LEAD TO A SURFACE LOW AND ASSOCIATED FRONTAL
SYSTEM MOVING SOUTHEAST MONDAY THROUGH WEDNESDAY NIGHT. A HIGHER
CHANCE FOR THUNDERSTORMS OCCURS TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE EAST. THE PRECIPITABLE WATER RATIOS WILL BE
HIGHER WHERE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS THAT MAY
FORM. AS THE FRONT MOVES EAST AND SOUTH THURSDAY THE TRAILING END
OF THE FRONT BACKS WEST AND NORTHWEST THROUGH THE WESTERN
PANHANDLE. IF THE FRONT STALLS ACROSS NORTHERN KANSAS AS SHOWN...A
PREVAILING EASTERLY SURFACE FLOW WOULD INCREASE THE MOISTURE
SUPPLY FOR INCREASED CLOUDS INTO THE EXTENDED PERIOD. A CHANCE OF
THUNDERSTORMS DAILY LINGERS AS THE STALLED BOUNDARY TO THE SOUTH
WOULD KEEP TEMPERATURES CLOSER TO NORMAL...OR BELOW NORMAL
...GOING FORWARD WITH DAYTIME HIGHS IN THE 80S OVER THE
SOUTHWEST...AND 70S IN THE NORTH AND NORTH CENTRAL. MODEL
CONSENSUS DIVERGES BEYOND WEDNESDAY NIGHT WITH A SUPERBLEND OF THE
SOLUTIONS USED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1235 AM CDT MON AUG 4 2014
THERE IS STILL A POSSIBILITY OF SHOWERS ALONG THE NEBRASKA-SOUTH
DAKOTA BORDER TONIGHT IN THE 07-12Z PERIOD. THE RAPID UPDATE
SHORT RANGE MODELS INDICATE THAT. IT IS POSSIBLE THAT CEILING
WILL BE LESS THAN 3000 FEET AGL WITH VISIBILITY LESS THAN
5SM...BUT ONLY ONE SIMULATION INDICATES THAT. THAT RESULTS IN
CONSIDERABLE UNCERTAINTY. OTHER SHORT RANGE PROJECTIONS HINT AT
CEILING BELOW 1000 FEET...BUT THERE IS NO CONSENSUS ON THE
LOCATION. FOR THE TIME BEING...THEN...WE WILL KEEP CEILING ABOVE
3000 FEET AGL AND VISIBILITY AT OR ABOVE 5SM IN THE TERMINAL
FORECAST FOR VTN.
WITH NO SIGNIFICANT CHANGE IN THE WEATHER PATTERN...ISOLATED
THUNDERSTORMS CAN BE EXPECTED AGAIN MONDAY EVENING. CURRENT
INDICATIONS ARE THAT THEY WILL BE ALONG THE NEBRASKA-SOUTH DAKOTA
STATE LINE JUST WEST OF VTN. HOWEVER...WITH MUCH UNCERTAINTY IN
THE LOCATION AND TIMING...THEY WILL NOT BE INCLUDED IN THE
TERMINAL FORECASTS FOR LBF AND VTN AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SUN AUG 3 2014
ON THE NORTH PLATTE RIVER...FROM LAKE MCCONAUGHY DOWNSTREAM TO
BRADY...IRRIGATION RELEASES CONTINUE TO SLOWLY CREEP UP THE FLOWS
WITH THE CURRENT STAGE AT THE NORTH PLATTE GAGE AT 5.4 FEET. THE
RIVER FORECAST FOR THE NORTH PLATTE GAGE...NEAR THE HIGHWAY 83
BRIDGE...IS FOR FLOWS TO REMAIN AROUND 5.5 FEET THROUGH THURSDAY.
THERE IS A CHANCE FOR THUNDERSTORMS DAILY WHERE SOME FLUCTUATIONS
ARE POSSIBLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...KECK
AVIATION...MASEK
HYDROLOGY...KECK
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
126 AM EDT MON AUG 4 2014
.SYNOPSIS...
A COASTAL FRONT AND ABUNDANCE OF TROPICAL MOISTURE WILL KEEP THE
WEATHER UNSETTLED THROUGH MONDAY. TROPICAL STORM BERTHA WILL REMAIN
MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY...
ALTHOUGH THE RIP CURRENT RISK WILL LIKELY INCREASE. MORE TYPICAL
SUMMER WEATHER RETURNS WEDNESDAY AND THURSDAY AS DRYING AND WARMING
TAKE PLACE. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD
BEHIND A COLD FRONT.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 130 AM MONDAY...RADAR AND LATEST HRRR MODEL RUNS WERE THE
BASIS FOR THE UPDATE EARLY THIS MORNING. THE I-95 CORRIDOR SHOULD
REMAIN DRY THROUGH DAYBREAK WITH THE BEST PRECIPITATION FOCUSED DOWN
AT THE COAST...PARTICULARLY ACROSS THE CAPE FEAR/WILMINGTON AREA
WHERE AREAL AVERAGES OF 1/2 INCH OF RAIN IS EXPECTED BY DAYBREAK. A
WEAK LOW OBSERVED ON RADAR ANIMATIONS MADE LANDFALL NEAR HOLDEN
BEACH A LITTLE EARLIER WITH IMPACTS ON WIND DIRECTIONS NOTED. WINDS
ALONG THE SC COAST SHOULD VEER MORE EASTERLY/SOUTHEASTERLY WITH
TIME. PREVIOUS DISCUSSION FROM 1100 PM FOLLOWS...
RADAR ANIMATIONS SHOW AN INTERESTING BUT WEAK LOW-LEVEL CIRCULATION
CURLING ONSHORE INTO THE BRUNSWICK COAST LATE THIS EVENING. IN
LONG-LOOPS OF SATELLITE ONE CAN TRACE BACK THIS SMALL FEATURE TO THE
MORE OPEN SEA BEFORE IT TRAVELED UNDER CLOUDS CLOSER TO THE COAST
HERE.
THE LATEST SPC MESOANALYSIS PLOTS CONFIRM DIURNAL INSTABILITY IS
INCREASING OVER THE COASTAL WATERS AS IS LOW-LEVEL CONVERGENCE
NEAR THE COAST AS LAND WINDS DECOUPLE. OF NOTE IS A SHARPENING
INVERTED COASTAL TROUGH OFFSHORE...AS LOW PRESSURE AT THE SURFACE
OFF OF JACKSONVILLE FL DRIFTS NORTH. THIS FEATURE HAS DEEPENED A
BIT OVER THE LAST SEVERAL HOURS. AS A RESULT ONE CHANGE IN MIND IS
TO INCREASE SE WINDS ALONG OUR SC COAST OVERNIGHT...AND UPPING THE
POP VALUES IN THIS AREA AS CONVERGENCE AND THE PRESSURE GRADIENT
BOTH INCREASE. AM EXPECTING A NORTHWARD EXPANSION OF SHOWERS AND
TSTMS OFFSHORE TO ENCROACH AND IMPACT OUR COAST LATE TONIGHT AND
IF PERSISTENCE HAS A SAY...MUCH OF THE COAST WILL SEE RAIN AND
RUMBLES INTO DAYBREAK.
PWAT VALUES OF 2.1" OFFSHORE TO 2` ALONG THE COAST TO 1.6" OVER
OUR FAR INLAND LOCALS THIS EVENING. A BELT OF STRONGER MID-LVL
FLOW CAN BE SEEN IN VAPOR ANIMATIONS AHEAD OF THE UPPER TROUGH TO
OUR WEST. A FEW IMPULSES ARE ROUNDING THE BASE KEEPING THE WEATHER
UNSETTLED OVER PORTIONS OF AL/GA...AND THIS MAY BE A PLAYER FOR
OUR INLAND ZONES LATER AS WELL. A FLOOD WATCH REMAINS POSTED FOR
ALL OUR ZONES THROUGH MUCH OF MONDAY.
TEMPERATURES ACROSS INLAND LOCATIONS MAY LEVEL OFF FOR THE MOST
PART OVERNIGHT...PERHAPS BUMPING UP A DEGREE OR TWO ALONG THE
COAST LATE AS THE PRESSURE GRADIENT TIGHTENS...PARTICULARLY THE SC
COAST. GUSTS TO 20 MPH ALONG THE GEORGETOWN AND HORRY COAST SHOULD
NOT BE A SHOCK BY DAYBREAK. ANY TSTMS IN THE AREA WILL INCREASE THE
GUSTS FACTOR AS WELL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...DEEP MOISTURE PLUME WILL REMAIN IN THE VICINITY
OF THE COAST THROUGH MONDAY. THUS VERY LITTLE CHANGE EXPECTED WITH
THE NORTHWARD STREAM OF TROPICAL MOISTURE GIVEN THE POSITIONING OF
THE MID LEVEL TROUGH AXIS WEST OF THE FORECAST AREA AND A
SUBTROPICAL RIDGE CENTERED OVER BERMUDA. IMPULSES WITHIN THE DEEPER
SOUTHERLY FLOW WILL PROVIDE THE SPARK FOR ADDITIONAL CONVECTION
DURING MONDAY...AND COUPLED WITH THE EXPECTATIONS FOR HEAVY RAIN
AGAIN DURING THE OVERNIGHT WE HAVE EXTENDED THE FLOOD WATCH THROUGH
8 PM EDT MONDAY.
THE PRECIPITABLE WATER WILL BE A LITTLE LOWER BY TUESDAY...BUT NO
SIGNIFICANT DROP OFF IN PRECIPITABLE WATER IS EXPECTED UNTIL TUESDAY
NIGHT AS DEEPER WESTERLY FLOW DEVELOPS THROUGH A LARGE PART OF THE
COLUMN. BY THIS TIME...BERTHA WILL HAVE TRACKED FAR OFF THE CAROLINA
COAST AND RACED FAR OFF TO THE NORTHEAST BY TUESDAY NIGHT. SWELLS
WILL INCREASE FROM BERTHA BY TUESDAY AND PERSIST INTO WEDNESDAY
LIKELY LEADING TO A PERIOD OF ENHANCED RIP CURRENT ACTIVITY.
CLOUD COVER DURING MONDAY SUPPORTS UNDER-CUTTING MAV MAX
TEMPERATURES BY A COUPLE CATEGORIES. EACH NIGHT MAV MINS LOOK
REASONABLE WITH READINGS AROUND 70 INLAND TO THE LOWER 70S AT THE
IMMEDIATE COAST. MAV HIGHS ON TUESDAY MAY ALSO BE OVERDONE DEPENDING
ON THE CLOUD COVER...AND FOR NOW ONLY CUT THE GUIDANCE BY A COUPLE
DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...FAIRLY QUIET CONDITIONS WILL KICKOFF THE LONG
TERM PERIOD AS WEAK SFC HIGH PRESSURE REIGNS OVER THE AREA WITH
PURELY ZONAL FLOW ALOFT. THE FOCUS WILL BE ON THE PROGRESSION OF A
EASTWARD PROPAGATING TROUGH AS IT TRANSITIONS AND STRENGTHENS FROM
THE GREAT LAKES REGION INTO THE NORTHEAST WEDNESDAY INTO THURSDAY.
RAIN/THUNDERSTORM CHANCES WILL BE FAIRLY LOW BOTH DAYS...ESPECIALLY
GIVEN THE LACK OF AVAILABLE MOISTURE THROUGH THE ATMOSPHERIC
COLUMN...THOUGH COULD NOT ENTIRELY RULE OUT AN ISOLATED POP-UP AS A
RESULT OF THE AFTERNOON SEA BREEZE OR PIEDMONT TROUGH. LATEST
GUIDANCE SEEMS TO BE IN PRETTY GOOD AGREEMENT WITH THE SOUTHEASTWARD
PROGRESSION OF A COLD FRONT...INITIATED FROM EASTWARD MOVING TROUGH
TO OUR NORTH. ANTICIPATE THIS FEATURE TO PUSH THROUGH THE FORECAST
GIVEN THE AFOREMENTIONED SOMEWHAT LACK OF MOISTURE...NOT
ANTICIPATING MUCH IN THE WAY OF PRE-FRONTAL DEVELOPMENT...BUT AS THE
FRONTAL BOUNDARY STALLS JUST OFFSHORE SOUTH OF OUR AREA ON FRIDAY
AND THEN LIFT NORTHWARD OVERNIGHT INTO SUNDAY WITH THE DEVELOPMENT
OF A COASTAL LOW...WILL SEE AN SLIGHT INCREASE OF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND.
HIGH TEMPERATURES WEDNESDAY INTO THURSDAY WILL BE AROUND 90
DEGREES...DROPPING INTO THE UPPER 80S FRIDAY WITH THE PASSAGE OF THE
COLD FRONT...CONTINUING THROUGH THE END OF THE PERIOD. OVERNIGHT
LOWS WILL BE IN THE UPPER 60S/LOW 70S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...APPROACHING SHORT WAVE IMPULSES WILL PRODUCE WIDESPREAD
SHOWERS AT THE COASTAL TERMINALS THROUGH AT LEAST THIS
MORNING...PERHAPS INTO THE AFTERNOON AS WELL. ISOLATED THUNDER IS
POSSIBLE EARLY THIS MORNING. SHOWERS MAY SPREAD TO THE KLBT TERMINAL
AFTER DAYBREAK...WITH CONSIDERABLE MODEL UNCERTAINTY ON WHETHER KFLO
GETS PRECIP OF IT REMAINS JUST EAST. CONVECTION ASSOCIATED WITH A
COASTAL LOW WILL SPREAD NORTH AFFECTING KCRE/KMYR INITIALLY...THEN
SPREADING NORTH ALONG THE COAST. SOME LETUP IN PRECIPITATION IS
POSSIBLE IN MID AFTERNOON AT THE COASTAL TERMINALS.
IFR/LIFR SHOULD DEVELOP SHORTLY AT KFLO/KLBT. TEMPO IFR IN HEAVIER
SHOWERS AT THE COASTAL TERMINALS. MVFR/TEMPO IFR AFTER 15Z.
EXTENDED OUTLOOK...SHRA/TSRA/IFR/LIFR LIKELY THROUGH MON NIGHT WITH
CONDITIONS IMPROVING TO WIDELY SCATTERED SHOWERS/TEMPO MVFR TUES.
VFR WED. CHANCE OF SHRA/TSRA/TEMPO MVFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM MONDAY...WINDS HAVE A DISTINCT CYCLONIC SPIN AROUND A
WEAK LOW THAT MOVED ONSHORE IN CENTRAL BRUNSWICK COUNTY NEAR HOLDEN
BEACH IN THE PAST HOUR. CHANGES TO THE FORECAST HAVE ATTEMPTED TO
CAPTURE THE CURRENT WIND DIRECTIONS WITH RENEWED VEERING WITH TIME
ALONG THE SC COAST AS THE NORTHEASTERLY WINDS ASSOCIATED WITH THE
WEAK LOW FADE. SEAS RANGE FROM 3-4 FEET ON LATEST BUOY OBSERVATIONS.
PREVIOUS DISCUSSION FROM 1100 PM FOLLOWS...
GRADIENT IS STARTING TO TIGHTEN AND WILL HOIST A SCEC FOR THE SC
WATERS FOR THE LIKELIHOOD OF 20 KT WINDS AND 4-5 FT SEAS LATE
TONIGHT. SOUTHEAST WINDS WILL CONTINUE THROUGH THE PERIOD WITH A
SLIGHT INCREASE IN SPEEDS EXPECTED TONIGHT AHEAD OF WEAK LOW LIFTING
NORTH FROM THE BAHAMAS. SPEEDS SHOULD REMAIN WITHIN THE 10 TO 20 KT
RANGE THROUGH THE END OF THE PERIOD. SEAS WILL RUN 3 TO 5 FT. LOW
AMPLITUDE SWELL WAVES FROM BERTHA ARE ANTICIPATED SOMETIME MONDAY.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...E-SE FLOW WILL PREVAIL MONDAY...THEN LIGHT
NORTHERLY FLOW TUESDAY MORNING PRIOR TO BACKING TO A LIGHT WESTERLY
DIRECTION. EVEN WITH LIGHT WIND SEAS WILL BE ON THE INCREASE MONDAY
NIGHT INTO TUESDAY AS SWELLS FROM BERTHA MOVE ACROSS THE WATERS. THE
SEAS MAY RESULT IN MARGINAL SMALL CRAFT CONDITIONS...BUT WILL CREATE
SOME HAZARDS AROUND INLET ENTRANCES DURING TIMES OF FALLING TIDE.
WINDS/SEAS ALSO LOCALLY HIGHER IN ANY SHOWERS/TSTMS THROUGH THE
PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...WEAK HIGH PRESSURE ON WEDNESDAY WILL BE REPLACED
BY AN APPROACHING COLD FRONT THURSDAY NIGHT INTO FRIDAY FROM THE
NORTHWEST. WEST-SOUTHWESTERLY FLOW WILL PERSIST THROUGH THE
PERIOD...WITH SUSTAINED WINDS INCREASING UP TO 15 KTS WEDNESDAY
NIGHT INTO THURSDAY...DECREASING TO AROUND 10 KTS BY FRIDAY MORNING
BEFORE SHIFTING AND BECOMING 5 TO 10 KTS WITH THE FRONT. SEAS WILL
BE 2 TO 3 FT OVERALL...WITH 4 FTERS POSSIBLE ESPECIALLY IN THE OUTER
WATERS OVERNIGHT INTO THURSDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH MONDAY EVENING FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
NEAR TERM...MJC/TRA
SHORT TERM...SRP
LONG TERM...SGL
AVIATION...MRR/TRA
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
404 AM CDT MON AUG 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1055 PM CDT SUN AUG 3 2014
GENERALLY VFR CONDITIONS WILL CONTINUE THROUGH 05/06Z. ISOLATED
-TSRA POSSIBLE MAINLY NORTHERN PART OF THE FORECAST AREA DURING
THE PERIOD. FOR NOW CHANCE AT ANY POINT IS TOO LOW TO INCLUDE IN
TAF FORECASTS. ALSO A POSSIBILITY IS LOWERING OF VISIBILITY TO
3-5SM IN PATCHY LIGHT FOG 09Z-14Z. FOR EXPECTED AREAS OF CLOUD
COVER AND SOME WEAK LOW LEVEL FLOW HAVE ALSO LEFT THIS OUT OF TAF
FORECASTS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
333 AM CDT MON AUG 4 2014
.SHORT TERM...
(Today and Tonight)
A weak lower to mid-level disturbance along the Texas coast will
move to the southwest today, while the upper ridge remains in
place from northern Mexico and the Texas Big Bend region north
into the central Rockies.
As the disturbance moves southwest today, associated lower to
mid-level moisture will move west into our area. The ridge to our
west is not strong and more of a "dirty ridge." The combination
of surface heating, moisture increase and sufficient
destabilization could allow isolated or widely scattered showers
and thunderstorms to develop over our east-central and
southeastern counties, mainly during the afternoon. The 00Z GFS,
TTU WRF and HRRR models indicate this potential. Carrying a slight
chance PoP for the area southeast of a Sonora to Eden to Lake
Brownwood line. Have a lingering slight chance PoP this evening
until 9 PM for nearly the same area. This convection will be
diurnally driven and dissipate by sunset, with clear to partly
cloudy skies expected overnight.
The 850mb temperatures increase only slightly today, mainly across
the western part of our area. With this indication and an
anticipated increase in cloud cover, going with highs about the
same as yesterday across our eastern and central counties, and
around a degree warmer in our western counties. Lows tonight are
expected to be mostly in the upper 60s.
19
.LONG TERM...
(Tuesday through Sunday)
The subtropical ridge axis currently runs in a general north-south
orientation along the front range, but will flatten over the
next few days as the large trough over the Great Basin ejects
shortwave energy over the crest of the ridge. Despite unimpressive
500 mb heights of 591-594 dam, a strong thermal ridge will reside
in the 850-700 mb layer, pushing temperatures well into the 90s
areawide, potentially reaching triple digits later this week. Min
temps will increase as well, with mid 70s anticipated by Thursday
morning. The general pattern will be an afternoon cumulus field
with clearing skies during the evening and overnight hours. Rain
chances will remain minimal due to the presence of the ridge and
dearth of deep moisture. That said, if any precipitation does
occur Tuesday through Thursday, it would more than likely be on
Tuesday afternoon.
The ECMWF and GEM are bringing a cold front south on Friday,
stalling the boundary in the vicinity of the Red River. The GFS,
however, maintains southerly flow well into the central plains. If
this boundary does verify, we`ll likely have to consider at
least a mention of isolated showers and thunderstorms Friday and
Saturday afternoon, despite the ridge being overhead. That said,
the juxtaposition of the front and the ridge appears unlikely.
Otherwise, expect the hot and generally dry conditions to
continue.
As we move through the weekend, both the GFS and ECMWF and ECMWF
are hinting that a TUTT low will develop and move across the
western Gulf of Mexico into south TX. With the upper-level ridge
centered over the region, this TUTT is likely to remain well to
our south, generally to far away to have much of an effect. If the
ridge is a bit weaker, this feature could yield isolated
convection Sunday into Monday. However, at this time, confidence is
far too low to include a mention in the forecast.
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 69 94 73 97 / 5 10 5 5 5
San Angelo 93 68 95 71 98 / 5 10 5 5 5
Junction 92 69 94 72 96 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19/25
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1138 PM CDT SUN AUG 3 2014
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
MODELS STILL HAVING TROUBLE WITH THE GENERAL PATTERN AND AVAILABLE
MOISTURE. THE RAP PERFORMED WELL LAST NIGHT AND IS A BIT
AGGRESSIVE WITH RAIN TONIGHT BUT OVERALL IS DOING OK. LEANED
TOWARD THE RAP THROUGH 12Z AND THE GFS THEREAFTER. FCST SOUNDINGS
KEEP MSTR LEVELS BETWEEN 1.5 AND 1.7 INCHES. WILL CARRY VCSH ALONG
THE COAST THROUGH 12Z AND MIGHT NEED A VCSH FOR INLAND SITES LATE
MON AFTN. WINDS WILL REMAIN LIGHT FOR MUCH OF THE TAF PERIOD WITH
A BRIEF UPTICK IN SE WINDS ALONG THE COAST ON MON AFTN. 43
&&
.PREV DISCUSSION... /ISSUED 948 PM CDT SUN AUG 3 2014/
UPDATE...
SEE DISCUSSION FOR EVENING UPDATE.
DISCUSSION...
SURFACE LOW PRESSURE DID NOT MOVE AS FAR TO THE WEST AS EXPECTED
TODAY WHICH HELPED TO KEEP ALMOST THE ENTIRE AREA DRY THIS
AFTERNOON. THE LOW PRESSURE IS EXPECTED TO WASH OUT TOMORROW OFF
THE COAST NEAR THE LA/TX BORDER. HIGH RES MODELS AGAIN SHOW
ANOTHER DAY WITH MODERATE COVERAGE THANKS TO THE SURFACE LOW. AM
SKEPTICAL ABOUT THIS SOLUTION THOUGH AS GLOBAL MODELS AREN`T AS
AGGRESSIVE WITH POPS. THE UPPER LEVELS ALSO REMAIN UNFAVORABLE. AT
250MB A BROAD TROUGH AXIS REMAINS TO OUR EAST PUTTING THE AREA IN
THE CONVERGENT REGION OF THE AXIS. THERE IS ALSO A WEAK JET
STREAK AT 250 WITH SOUTHEAST TEXAS IN THE RFQ OR CONVERGENT
REGION. WE WILL ALSO CONTINUE THE GRADUAL WARM UP TOMORROW WITH
HIGH TEMPERATURES IN THE LOW 90S. GIVEN 850 TEMPERATURES HAVE
RAISED HIGH TEMPS BY A DEGREE OR TWO ACROSS THE AREA. HAVE ALSO
DONE THE SAME TO THE LOW TEMPERATURES AS THE AIR MASS CONTINUES TO
MODERATE. NO OTHER CHANGES WERE MADE AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 318 PM CDT SUN AUG 3 2014/
DISCUSSION...
FINALLY STARTING TO SEE SOME DEVELOPMENT OVER OUR NRN ZONES IN RE-
LATION TO THE LOW. AREAL COVERAGE OF THIS ACTIVITY SHOULD CONTINUE
TO INCREASE ACROSS THE REGION THROUGH THIS EVENING. THIS PESKY LOW
PROGGED TO STICK AROUND THROUGH TOMORROW...ALONG WITH THE SCT RAIN
CHANCES FOR SE TX. HOWEVER WILL BE INTERESTING TO SEE IF THAT MORE
ORGANIZED PCPN THAT HAS REMAINED WELL TO THE EAST OF THE CWA TODAY
WILL TRANSLATE AND AFFECT SE TX TOMORROW.
OTHERWISE NOT A LOT OF CHANGE WITH THE REST OF THE FORECAST AS THE
UPPER RIDGE TRIES TO BUILD BACK OVER THE AREA FROM THE WEST DURING
THE MIDDLE PART OF THE WEEK. WARMER (NEAR NORMAL) TEMPS SET TO RE-
TURN BY TUE/WEDS AS RAIN CHCS ALSO RETURN TO THE MORE USUAL MAINLY
DAYTIME HEATING DRIVEN VARIETY. OF NOTE IN THE EXTENDED MODELS...A
HINT OF A DEVELOPING SHEAR AXIS/WEAKNESS IN THE UPPER RIDGE ACROSS
THE REGION FOR THE LATTER PART OF THE WEEK. THIS COULD LEAD TO IN-
CREASED POPS IF IT DOES VERIFY. 41
MARINE...
A WEAK PRESSURE GRADIENT OVER THE WATERS WILL CORRESPOND TO LIGHT
WINDS...MAINLY 10 KNOTS OR LESS...TONIGHT AND MOST OF MONDAY. THE
GRADIENT WILL INCREASE SOMEWHAT TOWARD MID WEEK...AS HIGH PRESSURE
BUILDS OVER THE GULF...WITH SOUTHEAST TO SOUTHERLY FLOW GETTING INTO
THE 10 TO 15 KNOT RANGE. 46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 92 73 94 74 / 20 30 10 20 10
HOUSTON (IAH) 74 91 74 94 75 / 20 30 10 20 10
GALVESTON (GLS) 80 90 79 90 80 / 20 30 10 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
200 AM EDT MON AUG 4 2014
.SYNOPSIS...
AN UPPER TROUGH RESIDES OVER THE REGION THROUGH TUESDAY...BUT THE
OVERALL FLOW TURNS MORE TO THE WEST. MEANWHILE...BERTHA STAYS WELL
OFFSHORE HEADING INTO THE WORKWEEK. A COLD FRONT IS EXPECTED TO
DROP TO THE MID ATLANTIC AND SOUTHERN APPALACHIANS BY THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT SUNDAY...
AN UPPER LOW PRESSURE WAS CENTERED OVER WESTERN PA...WITH ITS
ASSOCIATED TROUGH AXIS TRAILING SOUTH INTO THE CENTRAL APPALACHIANS.
A FRONTAL BOUNDARY WAS STALLED ALONG THE COASTS OF NC AND SC. THE
WEDGE OF HIGH PRESSURE ALONG THE LEE OF THE APPALACHIANS HAS
ERODED.
FOR THE OVERNIGHT...WILL HAVE TO MONITOR THE UPPER TROUGH AXIS FOR
POTENTIAL SHOWER DEVELOPMENT. AS OF 10PM THE TROF AXIS WAS
POSITIONED NR THE BLUE RIDGE...WITH A NARROW AXIS OF MOISTURE
CONVERGENCE PRESENT FROM THE DC AREA IN NORTHERN VA...TO NEAR
GREER SOUTH CAROLINA...PASSING THROUGH OUR CWA WAY OF A
LYH...MTV...MWK LINE. WITHIN THIS NARROW CORRIDOR...SHOWERS ARE
POSSIBLE. ATTM THE GREATEST COVERAGE WAS NORTH OF OUR CWA FROM
CHO-DCA. OTHER SHOWERS...MORE ISOLATED IN NATURE...WERE OCCURRING
FROM MOUNT AIRY NC...MWK...TO HICKORY...HKY. THE HRRR MODEL
MAINTAINS AREA OF LIFT VCNTY OF THE NW PIEDMONT OF NC THROUGH
ABOUT 06Z/2AM...SO LIKEWISE MAINTAINED THE HIGHEST POPS WITHIN
OUR CWA TO THIS CORRIDOR THROUGH MIDNIGHT.
AFTER MIDNIGHT...CONVECTION IS EXPECTED TO WANE. PATCHY FOG IS
THEN EXPECTED TO DEVELOP WITH A RETURN OF LOW LEVEL STRATUS
CLOUDS IN AND AROUND THE AREAS OF FOG. LOWS TONIGHT WILL RANGE
FROM THE MID TO UPPER 50S ACROSS THE MOUNTAINS WITH LOW TO MID 60S
ACROSS THE PIEDMONT.
ON MONDAY...MODELS DIFFER ON THE IMPACT SURFACE LOW PRESSURE THAT
FORMS ALONG THE STALLED FRONT ALONG THE COAST OF THE CAROLINAS
IMPACTS OUR WEATHER AS IT MOVES NORTHWARD ALONG THE FRONT. THE NAM
IS THE MOST AGGRESSIVE IN BRINGING A SUBSTANTIAL SLUG OF MOISTURE
INTO AT LEAST THE SOUTHEAST PART OF THE AREA BY TOMORROW AFTERNOON.
THIS IS A SUBSTANTIAL AMOUNT COMPARED TO GFS/ECWMF/CANADIAN
SOLUTIONS WHICH KEEP THE ACTIVITY MORE TO OUR EAST. THE NAM HAS BEEN
OVERDOING PRECIPITATION AMOUNTS AND HAS BEEN OFF ON THE BULLSEYE OF
PRECIPITATION CENTERS THAT PAST FEW DAYS...AND LIMITED CREDENCE WILL
BE GIVEN TO ITS LATEST SOLUTIONS. THE DRIER GFS/ECMWF/CANADIAN
SOLUTIONS WILL CONTINUE TO BE FAVORED IN OUR FORECAST. THIS DOES NOT
MEAN NO PRECIPITATION...BUT RATHER MORE OF ISOLATED DAYTIME
CONVECTION MAINLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE
WHERE LOW LEVEL TRAJECTORIES WILL ADD AN ELEMENT OF UPSLOPE. FOR
HIGH TEMPERATURES...FAVORING A SOLUTION THAT IS CLOSER TO THE MILDER
MOSGUIDE GRIDS AS COMPARED TO THE COOLER ADJMET. BELIEVE THE LATTER
IS BEING IMPACTED BY THE GREATER ABUNDANCE OF PRECIPITATION IT WANTS
TO GENERATE OVER THE REGION TOMORROW AFTERNOON...ESPECIALLY IN THE
SOUTHEAST PART OF THE AREA.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM EDT SUNDAY...
KEEPING THIS FORECAST CLOSER TO THE 00Z ECMWF SOLUTION WITH THE 12Z
GFS NOT TOO FAR OUT OF TOLERANCE WITH THE ECMWF. STILL LOOKING AT
TROUGH SITUATED OVER THE EAST...BUT EXPECTING RISING HEIGHTS AT 5H
INTO WEDNESDAY WITH INCREASED WESTERLY FLOW ALOFT AHEAD OF THE NEXT
FRONT.
FOR SHOWERS AND STORMS...EXPECT ISOLATED/SCATTERED ACROSS THE
MOUNTAINS AND FOOTHILLS TUESDAY WITHIN SFC CONVERGENT FIELD...WHILE
DEPARTING BERTHA OUT WELL EAST OF HATTERAS SHIFTS NE AWAY FROM LAND.
DIURNAL CONVECTION MAINLY AGAIN WEDNESDAY ALTHOUGH MAY LESS WITH
DOWNSLOPE INCREASING ALOFT. WILL HAVE SLIGHT TO LOW CHANCE SHRA/TSRA
ALONG AND WEST OF THE BLUE RIDGE WEDNESDAY AFTERNOON.
HIGHS WILL START WORKING BACK TO AT OR ABOVE NORMAL EAST OF THE
MOUNTAINS TUE-WED WITH HIGHS IN THE UPPER 80S/LOWER 90S...WHILE THE
MOUNTAINS WILL STAY CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH
LOWER 80S...THOUGH SOME MID 80S IN THE VALLEYS OF THE I-81 CORRIDOR.
HIGH LEVEL CLOUD COVER AHEAD OF THE FRONT WEDNESDAY MAY ROLL IN
FASTER THAN LATE AFTERNOON AS DEPICTED OFF THE ECWMF...WHICH
COULD BRING HIGHS A LITTLE LOWER IN THE MOUNTAINS/FOOTHILLS...BUT
STILL VERY WARM.
LOWS WILL BE CLOSE TO NORMAL MON-TUE NIGHT WITH UPPER 50S/LOWER 60S
MOUNTAINS TO MID TO UPPER 60S EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 155 AM EDT MONDAY...
CLEAR SKIES AND LIGHT/CALM WINDS WILL LEAD TO FAVORABLE
RADIATIONAL COOLING TONIGHT. MVFR FOG HAD ALREADY DEVELOPED AT
KLWB/KBCB AND KLYH. MODERATE TO HIGH CONFIDENCE THAT VISIBILITY
WILL CONTINUE TO LOWER WITH LIFR CONDITIONS AT THESE LOCATIONS BY
09Z/5AM. A SHALLOW LAYER OF LOW LEVEL MOISTURE OVER CENTRAL AND
EASTERN VIRGINIA AND NORTH CAROLINA REMAINED EARLY THIS MORNING.
IFR STRATUS HAD FORMED AT KDAN. EXPECT STRATUS TO PERSIST AT KDAN
UNTIL AFTER MIXING BEGINS SHORTLY AFTER SUNRISE.
MOSTLY LIGHT/VARIABLE THROUGH THE TAF VALID PERIOD...ALTHOUGH
TENDENCY FOR NE WINDS EAST OF THE BLUE RIDGE IN RESPONSE TO
COASTAL TROUGH/FRONT AND NW WINDS WEST OF THE BLUE RIDGE IN
RESPONSE TO OHIO VALLEY HIGH PRESSURE.
EXTENDED AVIATION DISCUSSION...
ANOTHER BROAD UPPER TROUGH WILL BECOME POSITIONED ACROSS THE
EASTERN THIRD OF THE UNITED STATES BY EARLY NEXT WEEK. AN
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY. FOR AVIATION
CONCERNS...MONDAY INTO TUESDAY WILL HAVE LIMITED PRECIPITATION
CHANCES...ISOLATED AT BEST...BUT THE POTENTIAL FOR OVERNIGHT
PATCHY FOG AND LOW STRATUS IN THE MOUNTAIN AND RIVER VALLEYS.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH ONGOING SHOWER AND SOME THUNDERSTORM ACTIVITY IN ASSOCIATION
WITH THE COLD FRONT. LIKEWISE...A GREATER ABUNDANCE OF LINGERING
OVERNIGHT SUB-VFR CONDITIONS ARE LIKELY WITH BOUNDARY LAYER
MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION. IF THERE IS
LIMITED MOVEMENT OF THE FRONT BY FRIDAY...EXPECT SIMILAR
CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...DS/PM
SHORT TERM...WP
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
159 AM EDT MON AUG 4 2014
.SYNOPSIS...
AN UPPER TROUGH RESIDES OVER THE REGION THROUGH TUESDAY...BUT THE
OVERALL FLOW TURNS MORE TO THE WEST. MEANWHILE...BERTHA STAYS WELL
OFFSHORE HEADING INTO THE WORKWEEK. A COLD FRONT IS EXPECTED TO
DROP TO THE MID ATLANTIC AND SOUTHERN APPALACHIANS BY THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT SUNDAY...
AN UPPER LOW PRESSURE WAS CENTERED OVER WESTERN PA...WITH ITS
ASSOCIATED TROUGH AXIS TRAILING SOUTH INTO THE CENTRAL APPALACHIANS.
A FRONTAL BOUNDARY WAS STALLED ALONG THE COASTS OF NC AND SC. THE
WEDGE OF HIGH PRESSURE ALONG THE LEE OF THE APPALACHIANS HAS
ERODED.
FOR THE OVERNIGHT...WILL HAVE TO MONITOR THE UPPER TROUGH AXIS FOR
POTENTIAL SHOWER DEVELOPMENT. AS OF 10PM THE TROF AXIS WAS
POSITIONED NR THE BLUE RIDGE...WITH A NARROW AXIS OF MOISTURE
CONVERGENCE PRESENT FROM THE DC AREA IN NORTHERN VA...TO NEAR
GREER SOUTH CAROLINA...PASSING THROUGH OUR CWA WAY OF A
LYH...MTV...MWK LINE. WITHIN THIS NARROW CORRIDOR...SHOWERS ARE
POSSIBLE. ATTM THE GREATEST COVERAGE WAS NORTH OF OUR CWA FROM
CHO-DCA. OTHER SHOWERS...MORE ISOLATED IN NATURE...WERE OCCURRING
FROM MOUNT AIRY NC...MWK...TO HICKORY...HKY. THE HRRR MODEL
MAINTAINS AREA OF LIFT VCNTY OF THE NW PIEDMONT OF NC THROUGH
ABOUT 06Z/2AM...SO LIKEWISE MAINTAINED THE HIGHEST POPS WITHIN
OUR CWA TO THIS CORRIDOR THROUGH MIDNIGHT.
AFTER MIDNIGHT...CONVECTION IS EXPECTED TO WANE. PATCHY FOG IS
THEN EXPECTED TO DEVELOP WITH A RETURN OF LOW LEVEL STRATUS
CLOUDS IN AND AROUND THE AREAS OF FOG. LOWS TONIGHT WILL RANGE
FROM THE MID TO UPPER 50S ACROSS THE MOUNTAINS WITH LOW TO MID 60S
ACROSS THE PIEDMONT.
ON MONDAY...MODELS DIFFER ON THE IMPACT SURFACE LOW PRESSURE THAT
FORMS ALONG THE STALLED FRONT ALONG THE COAST OF THE CAROLINAS
IMPACTS OUR WEATHER AS IT MOVES NORTHWARD ALONG THE FRONT. THE NAM
IS THE MOST AGGRESSIVE IN BRINGING A SUBSTANTIAL SLUG OF MOISTURE
INTO AT LEAST THE SOUTHEAST PART OF THE AREA BY TOMORROW AFTERNOON.
THIS IS A SUBSTANTIAL AMOUNT COMPARED TO GFS/ECWMF/CANADIAN
SOLUTIONS WHICH KEEP THE ACTIVITY MORE TO OUR EAST. THE NAM HAS BEEN
OVERDOING PRECIPITATION AMOUNTS AND HAS BEEN OFF ON THE BULLSEYE OF
PRECIPITATION CENTERS THAT PAST FEW DAYS...AND LIMITED CREDENCE WILL
BE GIVEN TO ITS LATEST SOLUTIONS. THE DRIER GFS/ECMWF/CANADIAN
SOLUTIONS WILL CONTINUE TO BE FAVORED IN OUR FORECAST. THIS DOES NOT
MEAN NO PRECIPITATION...BUT RATHER MORE OF ISOLATED DAYTIME
CONVECTION MAINLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE
WHERE LOW LEVEL TRAJECTORIES WILL ADD AN ELEMENT OF UPSLOPE. FOR
HIGH TEMPERATURES...FAVORING A SOLUTION THAT IS CLOSER TO THE MILDER
MOSGUIDE GRIDS AS COMPARED TO THE COOLER ADJMET. BELIEVE THE LATTER
IS BEING IMPACTED BY THE GREATER ABUNDANCE OF PRECIPITATION IT WANTS
TO GENERATE OVER THE REGION TOMORROW AFTERNOON...ESPECIALLY IN THE
SOUTHEAST PART OF THE AREA.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM EDT SUNDAY...
KEEPING THIS FORECAST CLOSER TO THE 00Z ECMWF SOLUTION WITH THE 12Z
GFS NOT TOO FAR OUT OF TOLERANCE WITH THE ECMWF. STILL LOOKING AT
TROUGH SITUATED OVER THE EAST...BUT EXPECTING RISING HEIGHTS AT 5H
INTO WEDNESDAY WITH INCREASED WESTERLY FLOW ALOFT AHEAD OF THE NEXT
FRONT.
FOR SHOWERS AND STORMS...EXPECT ISOLATED/SCATTERED ACROSS THE
MOUNTAINS AND FOOTHILLS TUESDAY WITHIN SFC CONVERGENT FIELD...WHILE
DEPARTING BERTHA OUT WELL EAST OF HATTERAS SHIFTS NE AWAY FROM LAND.
DIURNAL CONVECTION MAINLY AGAIN WEDNESDAY ALTHOUGH MAY LESS WITH
DOWNSLOPE INCREASING ALOFT. WILL HAVE SLIGHT TO LOW CHANCE SHRA/TSRA
ALONG AND WEST OF THE BLUE RIDGE WEDNESDAY AFTERNOON.
HIGHS WILL START WORKING BACK TO AT OR ABOVE NORMAL EAST OF THE
MOUNTAINS TUE-WED WITH HIGHS IN THE UPPER 80S/LOWER 90S...WHILE THE
MOUNTAINS WILL STAY CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH
LOWER 80S...THOUGH SOME MID 80S IN THE VALLEYS OF THE I-81 CORRIDOR.
HIGH LEVEL CLOUD COVER AHEAD OF THE FRONT WEDNESDAY MAY ROLL IN
FASTER THAN LATE AFTERNOON AS DEPICTED OFF THE ECWMF...WHICH
COULD BRING HIGHS A LITTLE LOWER IN THE MOUNTAINS/FOOTHILLS...BUT
STILL VERY WARM.
LOWS WILL BE CLOSE TO NORMAL MON-TUE NIGHT WITH UPPER 50S/LOWER 60S
MOUNTAINS TO MID TO UPPER 60S EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 750 PM EDT SUNDAY...
CLEAR SKIES AND LIGHT/CALM WINDS WILL LEAD TO FAVORABLE
RADIATIONAL COOLING TONIGHT. MVFR FOG HAD ALREADY DEVELOPED AT
KLWB/KBCB AND KLYH. MODERATE TO HIGH CONFIDENCE THAT VISIBILITY
WILL CONTINUE TO LOWER WITH LIFR CONDITIONS AT THESE LOCATIONS BY
09Z/5AM. A SHALLOW LAYER OF LOW LEVEL MOISTURE OVER CENTRAL AND
EASTERN VIRGINIA AND NORTH CAROLINA REMAINED EARLY THIS MORNING.
IFR STRATUS HAD FORMED AT KDAN. EXPECT STRATUS TO PERSIST AT KDAN
UNTIL AFTER MIXING BEGINS SHORTLY AFTER SUNRISE.
MOSTLY LIGHT/VARIABLE THROUGH THE TAF VALID PERIOD...ALTHOUGH
TENDENCY FOR NE WINDS EAST OF THE BLUE RIDGE IN RESPONSE TO
COASTAL TROUGH/FRONT AND NW WINDS WEST OF THE BLUE RIDGE IN
RESPONSE TO OHIO VALLEY HIGH PRESSURE.
EXTENDED AVIATION DISCUSSION...
ANOTHER BROAD UPPER TROUGH WILL BECOME POSITIONED ACROSS THE
EASTERN THIRD OF THE UNITED STATES BY EARLY NEXT WEEK. AN
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY. FOR AVIATION
CONCERNS...MONDAY INTO TUESDAY WILL HAVE LIMITED PRECIPITATION
CHANCES...ISOLATED AT BEST...BUT THE POTENTIAL FOR OVERNIGHT
PATCHY FOG AND LOW STRATUS IN THE MOUNTAIN AND RIVER VALLEYS.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH ONGOING SHOWER AND SOME THUNDERSTORM ACTIVITY IN ASSOCIATION
WITH THE COLD FRONT. LIKEWISE...A GREATER ABUNDANCE OF LINGERING
OVERNIGHT SUB-VFR CONDITIONS ARE LIKELY WITH BOUNDARY LAYER
MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION. IF THERE IS
LIMITED MOVEMENT OF THE FRONT BY FRIDAY...EXPECT SIMILAR
CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...DS/PM
SHORT TERM...WP
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
746 AM EDT MON AUG 4 2014
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE UP THE SOUTHEAST COAST ALONG A
STALLED FRONT THROUGH TUESDAY. A COLD FRONT WILL APPROACH FROM NORTH
LATE THIS WEEK AND STALL OVER OR NEAR THE AREA THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AROUND DAWN..A WEAK AREA OF LOW PRES WAS OFF THE NE FLORIDA COAST
WITH A STALLED COASTAL TROUGH EXTENDING NE THROUGH OUR COASTAL
WATERS. DEEP MOISTURE AXIS ON LATEST RAP ANALYSIS HAS BEEN NUDGING
BACK TOWARD THE COAST OVERNIGHT WITH DEEPEST MOISTURE OFFSHORE.
WIDESPREAD STRATUS ACROSS THE REGION AWAY FROM THE IMMEDIATE COAST
WITH SOME 1-3 MILE VSBYS IN SPOTS.
FORECAST DETAILS ON THE SKETCHY SIDE TODAY ALONG AND E OF THE I-95
CORRIDOR WITH HIGHEST RAIN CHANCES COASTAL AREAS...ESPECIALLY ALONG
THE SE GEORGIA COAST THIS MORNING AND NORTH OF BEAUFORT AFTER MID
MORNING...PERHAPS INTO THE AFTERNOON HOURS. THE NAM AND MANY OF
ITS VARIANTS SUGGEST THE SURFACE WAVE WILL CLOSE OFF AND DRIFT
FURTHER NORTHWARD TODAY THAN EITHER THE GFS/ECMWF PORTRAY. THE MAIN
IMPLICATION OF THIS WOULD BE A POTENTIAL FOR MORE SIGNIFICANT AND
WIDESPREAD CONVECTIVE RAINS ACROSS THE CENTRAL SOUTH CAROLINA
COAST. GIVEN THE UNCERTAINTIES AND MOST RECENT RUNS OF NSSL WRF
AND RUC RAPID REFRESH MODELS WE WERE HESITANT ON PAINTING TOO MUCH
QPF WITH THE MAIN SYNOPTIC BOUNDARY REMAINING OFFSHORE. EVEN
SO...PWATS UP TO 2.25 INCHES SUGGEST CONVECTIVE RAINS COULD BE
LOCALLY HEAVY WITH TORRENTIAL DOWNPOURS POSSIBLE EAST OF I-95. WILL
HAVE TO WAIT AND SEE IF ANY SIGNIFICANT RAINS COINCIDE WITH A MID
AFTERNOON HIGH TIDE IN DOWNTOWN CHARLESTON...CONFIDENCE VERY LOW
ON ANY MESOSCALE DETAIL AT THIS POINT.
FAR INLAND AREAS WILL PROBABLY HAVE TO WAIT UNTIL THIS AFTERNOON
FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP AND SOME MODELS
ARE QUITE SLIM WITH COVERAGE. WARMEST TEMPS SOUTH AND INLAND
TODAY... PERHAPS A FEW LOWER 90S. CLOSER TO UPPER 80S ACROSS SOUTH
CAROLINA AND MID 80S IN PLACES SUCH AS NE CHARLESTON COUNTY.
DECREASING RAIN CHANCES TONIGHT AS A SHORT WAVE ACROSS THE TENNESSEE
VALLEY BEGINS TO NUDGE THE DEEP MOIST AXIS...LOW PRES WAVE...AND
TS BERTHA FURTHER OFFSHORE AWAY FROM THE FORECAST AREA. MAINTAINED
A FEW LINGERING SHOWERS ALONG NORTHERN COASTAL AREAS...OTHERWISE
SOME INLAND CLEARING LIKELY. LATER SHIFTS MAY NEED TO ADD SOME
PATCHY FOG PER SOME OF THE 00Z GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...MODELS CONTINUE TO INDICATE THAT A WEAK LOW PRESSURE
SYSTEM WILL SLOWLY SHIFT NORTHEAST AND AWAY FROM THE AREA THROUGHOUT
THE DAY...THUS SUGGESTING A DECREASING TREND IN SHOWER AND/OR
THUNDERSTORM COVERAGE OVER THE SOUTHEAST. EXPECT LIGHT NORTHERLY
FLOW TO BACK TO THE WEST BEHIND THE DEPARTING LOW...RESULTING IN
LESS CLOUD COVER INLAND AND WARMING TEMPS AS SFC HEATING OCCURS.
LATEST 1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE
UPPER 80S TO LOWER 90S...WARMEST INLAND. OVERNIGHT TEMPS SHOULD
RANGE BETWEEN THE LOW TO MID 70S AWAY FROM THE COAST.
WEDNESDAY AND THURSDAY...THE PATTERN APPEARS DRYER AS HIGH PRESSURE
EXTENDS OVER THE WESTERN ATLANTIC WHILE A PIEDMONT TROUGH BECOMES
ESTABLISHED INLAND. HOWEVER...A FEW SHOWERS AND/OR THUNDERSTORM CAN
NOT BE RULED OUT EACH AFTERNOON WITH ENHANCED CONVERGENCE ALONG THE
TROUGH INLAND OR SEABREEZE NEAR THE COAST. TEMPS WILL BE WARMER THAN
PREVIOUS DAYS AS A WEST/NORTHWEST DOWNSLOPE FLOW OCCURS ALOFT DURING
PEAK SFC HEATING EACH AFTERNOON UNDER PARTLY CLOUDY SKIES. LATEST
1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE LOW TO
MID 90S...WARMEST INLAND. OVERNIGHT LOWS SHOULD RANGE IN THE LOW TO
MID 70S AWAY FROM THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH EARLY THIS
WEEKEND...WITH INCREASING MOISTURE LEVELS CHARACTERIZED BY PWATS
AROUND 2.0 INCHES. CHANCES OF SHOWERS AND/OR THUNDERSTORMS SHOULD
RESULT ON FRIDAY...WITH SLIGHTLY INCREASING COVERAGE INTO THE WEEKEND
AS THE FRONT STALLS OVER OR NEAR THE AREA. DEEP MOISTURE AND
CONVECTIVE ACTIVITY ASSOCIATED WITH THE FRONT WILL LIKELY LEAD TO
MORE CLOUD COVER AND SLIGHTLY COOLER TEMPS OVER THE AREA THIS
WEEKEND INTO EARLY NEXT WEEK. IN GENERAL...OVERALL HIGH TEMPS SHOULD
RANGE IN THE LOWER 90S ON FRIDAY...BEFORE COOLING INTO THE UPPER 80S
TO AROUND 90 LATER THIS WEEKEND INTO EARLY NEXT WEEK. OVERNIGHT LOWS
SHOULD RANGE IN THE LOW TO MID 70S...COOLEST INLAND EARLY NEXT WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS AT OR BELOW 400 FT AT 1130Z...PROBABLY A BIT SLOW TO
DISSIPATE OR LIFT GIVEN THE MOIST LAYER DEEPENING ACROSS THE AREA.
WE HAVE IFR CIGS PUNCTUATED BY SHOWER THREAT AFTER MID MORNING
AND CIGS SHOULD LIFT TO MVFR BY THIS AFTERNOON PER LATEST FORECAST
SOUNDINGS. CONFIDENCE ON SHOWER OR TSTM TIMING POOR TODAY GIVEN
SHIFTS IN LOW LEVEL MOISTURE CONVERGENCE FIELDS AND TRACK OF THE
LOW PRES TO THE SOUTH. MVFR OR LOWER CONDITIONS ARE POSSIBLE AGAIN
TONIGHT.
KSAV...LIFR CONDITIONS EARLY THIS MORNING WITH BUILD-DOWN STRATUS
IN PLACE AT THE TERMINAL. FORECAST SOUNDINGS SUGGEST LOW CIGS WILL
TEND TO DISSIPATE BY LATE MORNING WITH MVFR CIGS POSSIBLE THIS
AFTERNOON...ESPECIALLY IF SCATTERED CONVECTIVE RAINS DEVELOP. TONIGHT
THERE IS A CHANCE FOR MVFR/IFR CIGS ONCE AGAIN WITH PERHAPS SOME
LIGHT FOG.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS EARLY
TUESDAY AS LOW PRESSURE SHIFTS NORTHEAST OFF THE COAST. PREVAILING
VFR CONDITIONS SHOULD THEN OCCUR TUESDAY AFTERNOON THROUGH LATE
WEEK...BUT TEMPO FLIGHT RESTRICTIONS WILL REMAIN POSSIBLE EACH
AFTERNOON DUE TO SHOWERS AND/OR THUNDERSTORMS.
&&
.MARINE...
A WAVE OF LOW PRESSURE OFF THE FLORIDA COAST WILL LIFT NORTH ALONG
THE STALLED FRONT THROUGH TONIGHT. A TRICKY COASTAL WATERS FORECAST
TODAY WITH RESPECT TO GRADIENT ENHANCEMENTS AND TRACK OF THE
SURFACE WAVE. SEAS WERE ALREADY ELEVATED THIS MORNING AND
CONTINUED A SMALL CRAFT ADVISORY FOR OFFSHORE GEORGIA WATERS
THROUGH MID AFTERNOON AND IT MAY NEED A EXTENSION A LITTLE FURTHER
LATER TODAY. NEAR SHORE...MODELS DO NOT SHOW ANY SUBSTANTIAL
DEEPENING OF THE SURFACE WAVE AND EXPECT WINDS AVERAGING 15 KT
WITH THE PATTERN ONE OF CONVERGENCE INSTEAD OF JETTING. SEAS 3 TO
5 FT NEAR SHORE AND 4 TO 6 FT BEYOND 20 NM WITH MORE OF A GROUND
SWELL FROM BERTHA THAN LARGER LONG PERIOD SWELL. WINDS WILL BEGIN
TO BACK OFFSHORE OVER GEORGIA WATERS TONIGHT IN THE WAKE OF THE
LOW PASSING BY OFFSHORE.
TUESDAY THROUGH SATURDAY...SHOWERS AND THUNDERSTORMS COULD AFFECT
COASTAL WATERS INTO TUESDAY AS SFC LOW PRESSURE SHIFTS NORTHEAST AND
AWAY FROM THE AREA. CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS THIS OCCURS...WITH NORTH/NORTHEAST WINDS
EVENTUALLY BECOMING OFFSHORE AS THE SFC LOW PULLS AWAY FROM THE
AREA. HOWEVER...SWELLS ASSOCIATED WITH TROPICAL CYCLONE BERTHA WILL
AFFECT THE WATERS...WITH SEAS POSSIBLY BUILDING TO 5-6 FT OVER OUTER
GEORGIA WATERS ON TUESDAY. HIGH PRESSURE WILL THEN BUILD OVER THE
WATERS MID TO LATE WEEK WHILE A TROUGH OF LOW PRESSURE DEVELOPS
INLAND. THIS SHOULD RESULT IN SOUTH/SOUTHEAST WINDS AT OR BELOW
15 KT OVER THE WATERS...HIGHEST WITH AFTERNOON SEABREEZE
CIRCULATIONS THAT DEVELOP NEAR THE COAST. SEAS SHOULD RANGE BETWEEN
1-3 FT. SHOWER AND/OR THUNDERSTORM COVERAGE WILL LIKELY INCREASE LATER
THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTH AND STALLS
OVER OR NEAR THE AREA.
RIP CURRENTS...BORDERLINE RISK FOR MODERATE TODAY WITH ONGOING
SEAS A BIT HIGHER THAN ANTICIPATED. GROUND SWELL FROM TS BERTHA
ENOUGH TO FORECAST A MODERATE RISK TODAY TO BE ON THE SAFE SIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ374.
&&
$$
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
Area Forecast Discussion
National Weather Service Lincoln IL
1043 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 1040 AM CDT Mon Aug 4 2014
Will update the forecast to remove the morning fog over eastern IL,
otherwise just a few minor adjustments to sky cover and dewpoints today.
Weak 1021 mb high pressure over the Ohio river valley and ridging west
into the Ozarks of southern MO/northern AR will keep much of
eastern and southeast IL dry today. A short wave over central IA
to track se into NW and west central IL during the afternoon while
a frontal boundary over southern WI and near the MN/IA border
drops slowly southward into northern IL this evening. This will
develop isolated to scattered showers and thunderstorms during the
afternoon over areas mainly from I-55 nw with best chances nw of
the IL river. SPC has a 5% risk of damaging wind gusts and large
hail nw of I-55 late this afternoon and evening until sunset.
Highs in the mid 80s this afternoon looks on track. Somewhat muggy
dewpoints in the mid to upper 60s this morning to drop into the
upper 50s and lower 60s in southeast IL by mid afternoon and into
the low to mid 60s over the IL river valley. South winds less than
10 mph to prevail through the day.
07
&&
.AVIATION...
ISSUED 605 AM CDT Mon Aug 4 2014
Other than the threat for MVFR or local IFR vsbys in ground fog
over the next 60 to 90 minutes early this morning, VFR conditions
are expected this period. The main forecast challenge for later
today will be with the potential for TSRA, especially at KPIA
and KBMI as a weak cold front slips south into the lower Great
Lakes. Satellite data and surface observations indicate a band
of mid level clouds were tracking slowly east into west central
Illinois this morning. Bases of these clouds ranged from 5000 to
7000 feet with the overall movement mainly northeast. Forecast
soundings not showing much in the way of cumulus development excpt
across the far northern areas after 18z, but even there, it appears
to be mainly scattered at around 5000 feet. Will continue to include
a VCTS at PIA after 19z as this location will be closest to the
better instability. Not very confident after 00z with respect to
any of the convection that develops across the northwest to continue
across our area so will continue to hold off mentioning at any one
TAF site this evening. Surface winds will once again be a non-factor
with a southerly wind expected today at less than 10 kts, dropping
off to 5 kts or less aftr 00z.
Smith
&&
.PREV DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
918 AM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WIND SHIFT FROM WEST TO EAST-NORTHEAST THIS AFTERNOON WITH
COMBINATION OF COLD FRONT/LAKE BREEZE.
* SCATTERED SLOW MOVING SHRA/TSRA DEVELOPING LATE MORNING INTO
EARLY AFTERNOON AND CONTINUING INTO THIS EVENING/TONIGHT.
RATZER
//DISCUSSION...UPDATED 12Z...
WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...THOUGH WAS HARD TO DISCERN IN SURFACE OBS WITH GENERALLY
WEAK PRESSURE GRADIENT AND LIGHT/VARIABLE WIND FIELD. VARIOUS
MODELS VARY SIGNIFICANTLY IN FINE SCALE DETAILS OF WIND FIELD
BEYOND THIS MORNING...BUT GENERAL EXPECTATION IS THAT FRONT WILL
CONTINUE TO DRIFT SLOWLY SOUTH ALONG THE LAKE AND COMBINE WITH
AFTERNOON LAKE BREEZE TO BRING A SHIFT TO NORTHEAST WINDS BY
EARLY/MID AFTERNOON. GRADIENT CONTINUES TO REMAIN WEAK WITH SPEEDS
GENERALLY LESS THAN 10 KT EXPECTED...THOUGH COULD BE AROUND 10 KT
WITH INITIAL FRONT/LAKE BREEZE PASSAGE. EAST-NORTHEAST WINDS THEN
CONTINUE THROUGH REMAINDER OF TAF PERIOD.
AS FOR SHRA/TSRA...ISOLATED CELLS OVER PARTS OF WI AND SOUTHERN
LAKE MICHIGAN EARLY THIS AM IN REGION OF WEAK ELEVATED ASCENT.
COVERAGE EXPECTED TO INCREASE EARLY THIS AFTERNOON ALONG FRONTAL
ZONE AS CONVERGENCE IN LOW LEVEL WIND FIELD INITIATES CONVECTION
IN WEAKLY UNSTABLE AIR MASS. GREATEST COVERAGE ANTICIPATED ACROSS
SOUTHERN WI/EASTERN IA AND NORTHWEST IL WHERE SOME LOW LEVEL
MOISTURE POOLING WITH YIELD MORE UNSTABLE CONDITIONS...THOUGH
CONVECTION ALLOWING MODEL GUIDANCE ALL TREND TOWARD SOME INCREASED
POTENTIAL ALONG THE FRONT AND COMBINED LAKE BREEZE BOUNDARY
INTO CHICAGO AREA AS WELL. SHRA/TSRA POTENTIAL LOOKS TO BE HIGHEST
LATER IN THE AFTERNOON INTO THIS EVENING. SCATTERED SHRA MAY
CONTINUE OVERNIGHT AS WELL...WITH SEVERAL MINOR UPPER LEVEL
DISTURBANCES PASSING ACROSS THE FORECAST AREA.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-LOW IN TIMING OF SHRA/TSRA DEVELOPMENT LATE MORNING INTO
EARLY AFTERNOON.
* MEDIUM IN DETAILS OF WIND SHIFT/SPEED WITH COMBINED FRONT/LAKE
BREEZE THIS AFTERNOON.
* MEDIUM-LOW IN SPECIFIC LOCATIONS OF TSRA THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
RATZER
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENERALLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
606 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
&&
.AVIATION...
ISSUED 605 AM CDT Mon Aug 4 2014
Other than the threat for MVFR or local IFR vsbys in ground fog
over the next 60 to 90 minutes early this morning, VFR conditions
are expected this period. The main forecast challenge for later
today will be with the potential for TSRA, especially at KPIA
and KBMI as a weak cold front slips south into the lower Great
Lakes. Satellite data and surface observations indicate a band
of mid level clouds were tracking slowly east into west central
Illinois this morning. Bases of these clouds ranged from 5000 to
7000 feet with the overall movement mainly northeast. Forecast
soundings not showing much in the way of cumulus development excpt
across the far northern areas after 18z, but even there, it appears
to be mainly scattered at around 5000 feet. Will continue to include
a VCTS at PIA after 19z as this location will be closest to the
better instability. Not very confident after 00z with respect to
any of the convection that develops across the northwest to continue
across our area so will continue to hold off mentioning at any one
TAF site this evening. Surface winds will once again be a non-factor
with a southerly wind expected today at less than 10 kts, dropping
off to 5 kts or less aftr 00z.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
639 AM CDT Mon Aug 4 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT MON AUG 4 2014
Weak mid level trough shifting southeast across northern MO this
morning with another shortwave trough noted over SD. A few isolated
showers have developed over far eastern KS this morning with weak
isentropic ascent in the presence of a 35 kt LLJ. While the HRRR is
overdone on coverage of showers, the ARW and NMM high-res guidance
is also picking up on a few isolated showers continuing through mid
morning. Will leave a slight chance mention through this time, but
confidence is low for measurable precipitation.
Showers over SD are progged to dissipate over NE while the upper
ridge to our west shifts east into the area today and tonight. At the
surface, the trough axis shifts southward, pushing a weak boundary
near the Interstate 70 corridor by afternoon. Strength of
convergence on the boundary varies by the model with the 06Z NAM
being the outlier and most progressive with mid 60 dewpoints creating
a more unstable and weakly capped boundary layer during peak
heating. All other short and mid term guidance points to weak
forcing on the boundary, subsidence aloft while mid-level ascent is
displaced further east. With some near sfc convergence along the
boundary, cannot completely rule out an isolated storm and will hold
onto slight chances for thunderstorms this afternoon through early
evening. Any storm that is able to develop may produce gusty winds.
850 mb thermal ridge axis spreads east during the day just above
20C, rising highs into the lower and middle 90s. Another upper
trough passes over Iowa and MO tonight, increasing scattered mid
level clouds and lows in the low 70s.
.LONG TERM...(Tuesday through Sunday)
Issued at 321 AM CDT MON AUG 4 2014
The long term period is rather unsettled with a consistent train
of weak disturbances (and a few more organized ones) crossing the
central plains through the coming week.
Tuesday looks to have the best chance of the coming week to be dry
as the local area should be in between weak disturbances and the
low levels should be somewhat dried out...limiting instability.
That said, it should also be the hottest day of the next week with
slight ridging overhead and likelihood of quite a bit of sunshine.
Expect highs from the lower 90s far northeast to the upper 90s in
north central KS.
By late Tuesday night, the short wave currently in the Las Vegas
area should move out across Nebraska along a stationary front just
north of the KS/NE border, and seems likely to support a broad
area of thunderstorm activity/MCS. The bulk of the storms Tuesday
night are likely to stay north of the forecast area but could get
a few storms to develop/move in after midnight. By Wednesday, the
front will move south into the area as a northern stream trough
dives into the Great Lakes and brings a cooler airmass south. The
frontal progression along with additional short waves moving
across the Plains from the southwest will provide a favorable
setup for one or more convective complexes to impact the forecast
area Wednesday afternoon through Thursday morning with additional
development on Thursday afternoon. Moderate instability and weak
shear through this period should mitigate the severe potential,
but locally heavy rainfall/flooding may become an issue depending
how these convective complexes evolve. Dry antecedent soil
conditions will mitigate the flood threat a bit, but still seems
possible if a backbuilding situation sets up.
Thunderstorm chances continue through the remainder of the
forecast period but confidence in the details of timing and
magnitude is not high. Expect days with moderate to strong
instability but wind shear looks to remain marginally adequate for
organized storms. Thunderstorm chances will also depend at least
somewhat on how far the front moves south of the area as a
drier airmass may try to push in from the northeast if the front
moves far enough south.
Temperatures will cool a bit after the Wednesday frontal passage
and highs should be a bit below normal in the mid to upper 80s for
the Thursday through Sunday time frame with lows in the middle to
upper 60s.
&&
.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 631 AM CDT MON AUG 4 2014
Isolated TSRA continues to develop and move southward near KFOE.
Mentioned VCTS with coverage being too low for prevailing TSRA.
Surface trough veers south winds today towards the west by late
afternoon and northeast near 00Z. Light and VRB winds are expected
thereafter. Isolated TSRA is possible at KTOP/KFOE during late
afternoon and early evening. Coverage is sparse and confidence in
development is too low for mentioning at this time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Barjenbruch
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1007 AM EDT MON AUG 4 2014
.SYNOPSIS...
A COASTAL FRONT AND ABUNDANCE OF TROPICAL MOISTURE WILL KEEP THE
WEATHER UNSETTLED TODAY MAINLY ALONG THE COAST. BERTHA WILL REMAIN
MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY...
ALTHOUGH THE RIP CURRENT RISK WILL LIKELY INCREASE. MORE TYPICAL
SUMMER WEATHER RETURNS WEDNESDAY AND THURSDAY AS DRYING AND WARMING
TAKE PLACE. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD
BEHIND A COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...LATEST SFC OBS FROM ACROSS THE REGION
ILLUSTRATES AN IMPROVEMENT TO HORIZONTAL VSBY ABOVE 1 MILE. THIS
TREND WILL CONTINUE...ALBEIT SLOWLY...FOR THE REMAINDER OF THE
MORNING. THEREFORE...THE DENSE FOG ADVISORY IS NO LONGER NEEDED.
LOW STRATUS WILL TAKE A BIT LONGER TO AT LEAST IMPROVE ABOVE 1K
FEET. NEVERTHELESS...SKY CONDITIONS WILL REMAIN OVERCAST ACROSS
THE MAJORITY OF THE FA...WITH ANY TEMPORARY PEAKS OF THE SUN
OCCURRING WEST OF THE I-95 CORRIDOR.
STATUS QUO FOR THE FLOOD WATCH ACROSS THE FA...WHICH LIES
BASICALLY EAST OF THE I-95 CORRIDOR TO THE CAROLINA COASTS. ENOUGH
POTENTIAL FOR WIDESPREAD ONE HALF TO 1 INCH RAINFALL AMOUNTS WITH
POCKETS OF GREATER THAN 1 INCH AMOUNTS REMAINING POSSIBLE.
A STALLED FRONTAL BOUNDARY LIES PARALLEL TO THE CAROLINA
COASTLINES WITH AMPLE CONVECTION ALONG AND EAST OF THIS FRONT AND
STRATIFORM RAINS WEST OF THIS BOUNDARY. OCCASIONALLY...CONVECTION
WILL AT TIMES PUSH ONSHORE...WITH ADDITIONAL PCPN DEVELOPMENT
ACROSS THE INLAND PORTIONS OF THE FA AS THE DAY PROGRESSES.
PREVIOUS DISCUSSION..................................................
AS OF 645 AM MONDAY...THE 06Z NAM APPEARS TO BE CATCHING ONTO THE
TRENDS ESTABLISHED EARLIER BY THE GFS AND HRRR...AND IS LOWERING
ITS RAINFALL POTENTIAL ALONG AND WEST OF INTERSTATE 95 LATER
TODAY. BASED ON THIS AND RECENTLY OBSERVED RADAR TRENDS
OFFSHORE...I HAVE TRIMMED BACK BOTH RAINFALL PROBABILITY AND
AMOUNT FORECASTS AWAY FROM THE IMMEDIATE COAST TODAY. THIS HAS
GIVEN ME ENOUGH CONFIDENCE TO DROP THE FLOOD WATCH FOR THE REST OF
THE INTERIOR PEE DEE COUNTIES AND ROBESON COUNTY...LEAVING IT IN
EFFECT ONLY FOR THE COASTAL COUNTIES PLUS BLADEN AND COLUMBUS
COUNTIES. FOR BLADEN AND COLUMBUS THE WATCH IS UP MAINLY DUE TO
WATERLOGGED SOILS FROM OVER HALF A FOOT OF RAIN THAT FELL BETWEEN
ELIZABETHTOWN AND WHITEVILLE YESTERDAY.
ALSO...RECENT ASOS OBSERVATIONS REVEAL A GROWING AREA OF 1/4 MILE
VISIBILITIES ACROSS THE INTERSTATE 95 CORRIDOR. A DENSE FOG
ADVISORY HAS BEEN ISSUED HERE THROUGH 9 AM. PREVIOUS DISCUSSION
FROM 300 AM FOLLOWS...
THE RISK OF EXCESSIVE RAINFALL TODAY IS HIGHEST ALONG THE GRAND
STRAND BEACHES NORTHWARD INTO COASTAL SE NORTH CAROLINA. A STALLED
FRONT EXTENDING FROM THE FLORIDA EAST COAST NORTHWARD TO VERY NEAR
WILMINGTON SHOULD MOVE LITTLE THROUGH DAYBREAK. MODELS SHOW THE
BOUNDARY DRIFTING WESTWARD LATE THIS MORNING...BUT THEN RETREATING
BACK OFFSHORE THIS EVENING AS THE INCREASINGLY BROAD OUTER
CIRCULATION OF TROPICAL STORM BERTHA GRABS HOLD OF THE FRONT AND
JERKS IT EASTWARD. A DEEP STREAM OF TROPICAL MOISTURE ALONG THE
COAST IS NOT DIRECTLY ASSOCIATED WITH BERTHA BUT CONTAINS
PRECIPITABLE WATER VALUES IN EXCESS OF TWO INCHES.
WIND PROFILES FROM VIRTUALLY ANY MODEL SHOW A BELT OF FAIRLY STRONG
SOUTHEAST WINDS IN THE LOWEST FEW THOUSAND FEET OF THE ATMOSPHERE
AT THE COAST. AS THESE WINDS COLLIDE AND CONVERGE INTO WEAKER WIND
SPEEDS ON THE COOL SIDE OF THE FRONT...LIFT WILL BE GENERATED. THE
ATMOSPHERE IS CONDITIONALLY UNSTABLE AND WILL EASILY DEVELOP
CONVECTION GIVEN A NUDGE. MY FORECAST POPS ARE IN THE 80-100 PERCENT
RANGE ALONG THE COAST TODAY WITH AREAL RAINFALL FORECASTS 0.75 TO
1.25 INCHES. FARTHER INLAND RAIN CHANCES ARE LOWER...30 TO 60
PERCENT...DUE TO LESS CONVERGENCE ON THE INLAND SIDE OF THE BOUNDARY
AND DRIER AIR IN THE MID LEVELS AS YOU MOVE WESTWARD. HOWEVER WIND
PROFILES SHOW STORM MOTION WILL BE EXCEEDINGLY SLOW SO I CANNOT IN
GOOD CONSCIENCE REMOVE THE FLOOD WATCH ALONG THE I-95 CORRIDOR. FOR
DARLINGTON AND MARLBORO COUNTIES THE THREAT APPEARS SMALL ENOUGH TO
DROP THE WATCH WITH THIS MORNING`S FORECAST PACKAGE.
THERE IS CONSIDERABLE DISAGREEMENT BETWEEN THE 00Z GFS AND NAM
CONCERNING HOW FAR INLAND SIGNIFICANT RAINFALL DEVELOPS TODAY. THE
GFS IS PREFERRED...AND IT HAS THE SUPPORT OF THE ECMWF AND THE LAST
SEVERAL RUNS OF THE HRRR. THE SREF LOOKS MORE LIKE THE 00Z NAM...
UNSURPRISING SINCE THE SREF IS BASED LARGELY ON VARIOUS NAM MEMBERS.
HIGH TEMPS SHOULD AGAIN RUN WELL BELOW NORMALS FOR THIS DATE...
RANGING FROM AROUND 80 AT THE COAST TO 83-85 WELL INLAND...6-10
DEGREES BELOW NORMALS. LOWS TONIGHT SHOULD FALL TO NEAR 70 INLAND TO
THE LOWER 70S AT THE COAST...WITH ANOTHER ROUND OF LOW STRATUS
CLOUDS POSSIBLE IN THE VERY MOIST LOW-LEVEL AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...SMALL CHANCE FOR SOME LINGERING MOISTURE AND
RAIN CHANCES ON TUESDAY MAINLY ALONG THE COAST. SURFACE FLOW WILL
TURN OFFSHORE EARLY FOLLOWED BY LOW LEVEL FLOW SOON THEREAFTER. MID
LEVELS WSWRLY...NOT A NORMALLY MOISTURE-LADEN WIND DIRECTION. THESE
FACTORS SHOULD ALSO LEAD TO MORE SUNSHINE BREAKING OUT THAN THE AREA
HAS SEEN IN QUITE SOME TIME...AND THEREFORE WARMER
TEMPERATURES...PERHAPS EVEN CLIMO HIGHS. MID LEVEL TROUGH AXIS
SWINGS OFFSHORE TUESDAY NIGHT LEADING TO ZONAL AND DOWNSLOPING FLOW.
RAIN CHANCES WHILE NON-ZERO DUE TO A PIEDMONT TROUGH...WILL BE
NEGLIGIBLE. MOST AREAS SHOULD SEE A HIGH ON EITHER SIDE OF 90...A
FEW DEGREES ABOVE INLAND AND PERHAPS A FEW SHY ALONG THE COAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 PM MONDAY...PIEDMONT TROUGH GIVES WAY TO A MORE WEST-TO-EAST
TROUGHINESS AS COLD FRONT APPROACHES THURSDAY. ZONAL MID LEVEL FLOW
KEEPING COLUMN FAIRLY DRY AND MODELS NOT TOO EXITED ABOUT ANYTHING
OTHER THAN ISO SHWR/TSTM. COLD FRONT SLIDES THROUGH FRIDAY WITH
LITTLE LOW LEVEL MOISTURE FLUX AND CONTINUED MID LEVEL WESTERLY DRY
FLOW. GUIDANCE LOOKING A LITTLE WETTER WITH FROPA THOUGH AND SOME
LOW RAIN CHANCES APPEAR WARRANTED. THIS BOUNDARY MAY STALL ALONG THE
COAST FOR THE REMAINDER OF THE PERIOD WHILE WEDGING SETS UP OVER THE
PIEDMONT/COASTAL PLAIN. SATURDAY THROUGH MONDAY MAY THUS OFFER UP
PLENTY OF CLOUDS AND TEMPERED HIGHS AS WELL AS HIGHER THAN NORMAL
RAIN CHANCES.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...SYNOPTICALLY SIMILAR TO YESTERDAY...HOWEVER A BIT LESS
MOISTURE TO WORK WITH. CONVECTION IS MUCH LESS WIDESPREAD AND NOT
NEAR AS FAR INLAND AS YESTERDAY...NEVERTHELESS EXPECTED CONVECTION
TO BE ON THE INCREASE ALONG THE COAST...PEAKING OUT IN INTENSITY
AROUND 15Z WITH ISOLATED THUNDER. MOST OF THE NEAR TERM FORECASTING
BASED ON THE HRRR MODEL. INLAND...LOOKS LIKE LIFR CONDITIONS TO
CONTINUE THROUGH 14Z...WITH A SLOW IMPROVEMENT AFTER THAT BUT LIKELY
REMAINING IFR THROUGH MUCH OF THE FORECAST PERIOD...SINKING BACK
INTO LIFR TONIGHT.
EXTENDED OUTLOOK...SHRA/TSRA/IFR/LIFR LIKELY THROUGH MON NIGHT WITH
CONDITIONS IMPROVING TO WIDELY SCATTERED SHOWERS/TEMPO MVFR TUES.
VFR WED. CHANCE OF SHRA/TSRA/TEMPO MVFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...STALLED FRONTAL BOUNDARY LIES PARALLEL TO
THE ILM CWA COASTLINE...JUST OFFSHORE AND BEYOND 20 NM FROM THE
COAST. AS A RESULT...EXPECTING AN ONSHORE TRAJECTORY WITH THE WIND
FIELD...FROM NE THRU SE AROUND 10 KT. A E-SE GROUND SWELL WILL
BE THE PRIMARY DRIVER OF SIGNIFICANT SEAS ACROSS THE AREA WATERS.
COMBINED WITH LOCALLY PRODUCED WIND-WAVES...SIG. SEAS WILL HOVER
AROUND 4 FT.
PREVIOUS DISCUSSION.............................................
AS OF 645 AM MONDAY...THE FRONT HAS MOVED LITTLE SINCE 3
AM...CROSSING THE COASTLINE NEAR HOLDEN BEACH AND SEPARATING NORTH
WINDS ALONG THE SOUTH CAROLINA BEACHES FROM SOUTH WINDS OVER CAPE
FEAR. THIS BOUNDARY WILL BE THE FOCUS FOR NEW SHOWERS AND TSTMS
TODAY. THIS UPDATE MAINLY ADDRESSES NEAR-TERM WIND DIRECTIONS AND
COVERAGE OF SHOWERS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
A STALLED FRONT SITS JUST OFF THE SOUTH CAROLINA COAST...BUT RUNS
INLAND ACROSS COASTAL SE NORTH CAROLINA. THIS FRONT IS PRODUCING A
VARIETY OF WIND DIRECTIONS...PREVAILING SOUTHEASTERLY ALONG THE
COAST EAST OF OAK ISLAND...AND PREVAILING NORTH TO NORTHEASTERLY
ALONG THE GRAND STRAND. THE BOUNDARY IS EXPECTED TO PUSH INLAND
LATE THIS MORNING WITH EAST TO SOUTHEASTERLY WINDS DEVELOPING
THROUGHOUT THE AREA.
TROPICAL STORM BERTHA WILL NOT DIRECTLY AFFECT THE AREA...BUT WILL
MAKE ITS CLOSEST APPROACH TO THE COASTAL WATERS EARLY THIS EVENING.
BERTHA SHOULD REMAIN SEVERAL HUNDRED MILES OFFSHORE...SENDING SWELLS
INTO THE AREA BUT LITTLE ELSE. NONE OF TODAY`S RAIN OR WIND CAN BE
ATTRIBUTED TO THE STORM. AS BERTHA MOVES NORTH OF OUR LATITUDE
TONIGHT THE FRONT SHOULD BE PULLED BACK OFFSHORE...WITH WIND
DIRECTIONS TENDING TO BACK MORE NORTHEASTERLY WITH TIME.
SEAS AVERAGE 4-5 FEET CURRENTLY...AND MAY BUILD TO A SOLID 5 FEET
TONIGHT AS SWELL FROM BERTHA IMPACTS THE WATERS. SOME MODELS ARE
HINTING AT SOME 6-FOOTERS GETTING INTO THE WATER NEAR CAPE FEAR AND
EAST OF WINYAH BAY.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...BERTHA SWELL TO BE RAMPING UP RIGHT AROUND THE
START OF THE PERIOD. BERTHA ACCELERATES BY LATE MONDAY INTO EARLY
TUESDAY WITH ITS CLOSEST APPROACH SOME 300+ MILES OFFSHORE. THE
SWELLS MAY BE SUFFICIENT TO BRING A FEW SMALL CRAFT ADVISORY-WORTHY
6 FT SEAS TO NORTHERN ZONES BUT THERE IS ANOTHER FEW MODEL CYCLES
AND NHC FORECASTS REMAINING TO CLEAR UP ANY UNCERTAINTY. ANOTHER
AREA OF LOW PRESSURE MOVING NE ALONG FRONTAL BOUNDARY LAGS BEHIND
BERTHA...BEING SHALLOWER AND THUS LESS ENTRENCHED IN THE DEEP LAYER
FLOW. THIS LOW WILL KEEP WINDS FAIRLY LIGHT AND GENERALLY
NE...SHIFTING TO NW TUESDAY NIGHT AS IT MOVES BY. ADDITIONAL VEERING
THEN SLATED FOR WEDNESDAY AS WIND SPEEDS DROP ABOUT A CATEGORY.
BACKSWELL DOES NOT APPEAR TO LINGER LONG ACCORDING TO GUIDANCE AS
SEAS QUICKLY SETTLE INTO THE 2 TO 3 FT RANGE.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...INLAND PIEDMONT TROUGH TAKES ON A MORE WEST-EAST
ORIENTATION AS THURSDAY PROGRESSES AND GROWS NEARER TO THE COAST.
THIS IS IN RESPONSE TO APPROACH OF A COLD FRONT FROM THE NORTH AND
WEST. THERE MAY BE A SMALL DIRECTION VARIATION AS THIS OCCURS BUT
MAIN EFFECT WILL BE A DECREASE IN SPEED DUE TO THE SLIGHTLY
SLACKENED GRADIENT. COLD FRONT MOVES THROUGH EARLY FRIDAY TURNING
WINDS ONSHORE AND POSSIBLY ADDING 5 KT TO OVERALL SPEEDS. OVERALL
INCREASE IN WAVE HEIGHTS SHOULD BE MINOR BUT THE ONSHORE FLOW
DIRECTION MAY DECREASE THE NEARSHORE/OFFSHORE GRADIENT IN WAVE SIZE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ053>056.
NC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NCZ096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH/TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
657 AM EDT MON AUG 4 2014
.SYNOPSIS...
A COASTAL FRONT AND ABUNDANCE OF TROPICAL MOISTURE WILL KEEP THE
WEATHER UNSETTLED TODAY MAINLY ALONG THE COAST. BERTHA WILL REMAIN
MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY...
ALTHOUGH THE RIP CURRENT RISK WILL LIKELY INCREASE. MORE TYPICAL
SUMMER WEATHER RETURNS WEDNESDAY AND THURSDAY AS DRYING AND WARMING
TAKE PLACE. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD
BEHIND A COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM MONDAY...THE 06Z NAM APPEARS TO BE CATCHING ONTO THE
TRENDS ESTABLISHED EARLIER BY THE GFS AND HRRR...AND IS LOWERING
ITS RAINFALL POTENTIAL ALONG AND WEST OF INTERSTATE 95 LATER
TODAY. BASED ON THIS AND RECENTLY OBSERVED RADAR TRENDS
OFFSHORE...I HAVE TRIMMED BACK BOTH RAINFALL PROBABILITY AND
AMOUNT FORECASTS AWAY FROM THE IMMEDIATE COAST TODAY. THIS HAS
GIVEN ME ENOUGH CONFIDENCE TO DROP THE FLOOD WATCH FOR THE REST OF
THE INTERIOR PEE DEE COUNTIES AND ROBESON COUNTY...LEAVING IT IN
EFFECT ONLY FOR THE COASTAL COUNTIES PLUS BLADEN AND COLUMBUS
COUNTIES. FOR BLADEN AND COLUMBUS THE WATCH IS UP MAINLY DUE TO
WATERLOGGED SOILS FROM OVER HALF A FOOT OF RAIN THAT FELL BETWEEN
ELIZABETHTOWN AND WHITEVILLE YESTERDAY.
ALSO...RECENT ASOS OBSERVATIONS REVEAL A GROWING AREA OF 1/4 MILE
VISIBILITIES ACROSS THE INTERSTATE 95 CORRIDOR. A DENSE FOG
ADVISORY HAS BEEN ISSUED HERE THROUGH 9 AM. PREVIOUS DISCUSSION
FROM 300 AM FOLLOWS...
THE RISK OF EXCESSIVE RAINFALL TODAY IS HIGHEST ALONG THE GRAND
STRAND BEACHES NORTHWARD INTO COASTAL SE NORTH CAROLINA. A STALLED
FRONT EXTENDING FROM THE FLORIDA EAST COAST NORTHWARD TO VERY NEAR
WILMINGTON SHOULD MOVE LITTLE THROUGH DAYBREAK. MODELS SHOW THE
BOUNDARY DRIFTING WESTWARD LATE THIS MORNING...BUT THEN RETREATING
BACK OFFSHORE THIS EVENING AS THE INCREASINGLY BROAD OUTER
CIRCULATION OF TROPICAL STORM BERTHA GRABS HOLD OF THE FRONT AND
JERKS IT EASTWARD. A DEEP STREAM OF TROPICAL MOISTURE ALONG THE
COAST IS NOT DIRECTLY ASSOCIATED WITH BERTHA BUT CONTAINS
PRECIPITABLE WATER VALUES IN EXCESS OF TWO INCHES.
WIND PROFILES FROM VIRTUALLY ANY MODEL SHOW A BELT OF FAIRLY STRONG
SOUTHEAST WINDS IN THE LOWEST FEW THOUSAND FEET OF THE ATMOSPHERE
AT THE COAST. AS THESE WINDS COLLIDE AND CONVERGE INTO WEAKER WIND
SPEEDS ON THE COOL SIDE OF THE FRONT...LIFT WILL BE GENERATED. THE
ATMOSPHERE IS CONDITIONALLY UNSTABLE AND WILL EASILY DEVELOP
CONVECTION GIVEN A NUDGE. MY FORECAST POPS ARE IN THE 80-100 PERCENT
RANGE ALONG THE COAST TODAY WITH AREAL RAINFALL FORECASTS 0.75 TO
1.25 INCHES. FARTHER INLAND RAIN CHANCES ARE LOWER...30 TO 60
PERCENT...DUE TO LESS CONVERGENCE ON THE INLAND SIDE OF THE BOUNDARY
AND DRIER AIR IN THE MID LEVELS AS YOU MOVE WESTWARD. HOWEVER WIND
PROFILES SHOW STORM MOTION WILL BE EXCEEDINGLY SLOW SO I CANNOT IN
GOOD CONSCIENCE REMOVE THE FLOOD WATCH ALONG THE I-95 CORRIDOR. FOR
DARLINGTON AND MARLBORO COUNTIES THE THREAT APPEARS SMALL ENOUGH TO
DROP THE WATCH WITH THIS MORNING`S FORECAST PACKAGE.
THERE IS CONSIDERABLE DISAGREEMENT BETWEEN THE 00Z GFS AND NAM
CONCERNING HOW FAR INLAND SIGNIFICANT RAINFALL DEVELOPS TODAY. THE
GFS IS PREFERRED...AND IT HAS THE SUPPORT OF THE ECMWF AND THE LAST
SEVERAL RUNS OF THE HRRR. THE SREF LOOKS MORE LIKE THE 00Z NAM...
UNSURPRISING SINCE THE SREF IS BASED LARGELY ON VARIOUS NAM MEMBERS.
HIGH TEMPS SHOULD AGAIN RUN WELL BELOW NORMALS FOR THIS DATE...
RANGING FROM AROUND 80 AT THE COAST TO 83-85 WELL INLAND...6-10
DEGREES BELOW NORMALS. LOWS TONIGHT SHOULD FALL TO NEAR 70 INLAND TO
THE LOWER 70S AT THE COAST...WITH ANOTHER ROUND OF LOW STRATUS
CLOUDS POSSIBLE IN THE VERY MOIST LOW-LEVEL AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...SMALL CHANCE FOR SOME LINGERING MOISTURE AND
RAIN CHANCES ON TUESDAY MAINLY ALONG THE COAST. SURFACE FLOW WILL
TURN OFFSHORE EARLY FOLLOWED BY LOW LEVEL FLOW SOON THEREAFTER. MID
LEVELS WSWRLY...NOT A NORMALLY MOISTURE-LADEN WIND DIRECTION. THESE
FACTORS SHOULD ALSO LEAD TO MORE SUNSHINE BREAKING OUT THAN THE AREA
HAS SEEN IN QUITE SOME TIME...AND THEREFORE WARMER
TEMPERATURES...PERHAPS EVEN CLIMO HIGHS. MID LEVEL TROUGH AXIS
SWINGS OFFSHORE TUESDAY NIGHT LEADING TO ZONAL AND DOWNSLOPING FLOW.
RAIN CHANCES WHILE NON-ZERO DUE TO A PIEDMONT TROUGH...WILL BE
NEGLIGIBLE. MOST AREAS SHOULD SEE A HIGH ON EITHER SIDE OF 90...A
FEW DEGREES ABOVE INLAND AND PERHAPS A FEW SHY ALONG THE COAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 PM MONDAY...PIEDMONT TROUGH GIVES WAY TO A MORE WEST-TO-EAST
TROUGHINESS AS COLD FRONT APPROACHES THURSDAY. ZONAL MID LEVEL FLOW
KEEPING COLUMN FAIRLY DRY AND MODELS NOT TOO EXITED ABOUT ANYTHING
OTHER THAN ISO SHWR/TSTM. COLD FRONT SLIDES THROUGH FRIDAY WITH
LITTLE LOW LEVEL MOISTURE FLUX AND CONTINUED MID LEVEL WESTERLY DRY
FLOW. GUIDANCE LOOKING A LITTLE WETTER WITH FROPA THOUGH AND SOME
LOW RAIN CHANCES APPEAR WARRANTED. THIS BOUNDARY MAY STALL ALONG THE
COAST FOR THE REMAINDER OF THE PERIOD WHILE WEDGING SETS UP OVER THE
PIEDMONT/COASTAL PLAIN. SATURDAY THROUGH MONDAY MAY THUS OFFER UP
PLENTY OF CLOUDS AND TEMPERED HIGHS AS WELL AS HIGHER THAN NORMAL
RAIN CHANCES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...SYNOPTICALLY SIMILAR TO YESTERDAY...HOWEVER A BIT LESS
MOISTURE TO WORK WITH. CONVECTION IS MUCH LESS WIDESPREAD AND NOT
NEAR AS FAR INLAND AS YESTERDAY...NEVERTHELESS EXPECTED CONVECTION
TO BE ON THE INCREASE ALONG THE COAST...PEAKING OUT IN INTENSITY
AROUND 15Z WITH ISOLATED THUNDER. MOST OF THE NEAR TERM FORECASTING
BASED ON THE HRRR MODEL. INLAND...LOOKS LIKE LIFR CONDITIONS TO
CONTINUE THROUGH 14Z...WITH A SLOW IMPROVEMENT AFTER THAT BUT LIKELY
REMAINING IFR THROUGH MUCH OF THE FORECAST PERIOD...SINKING BACK
INTO LIFR TONIGHT.
EXTENDED OUTLOOK...SHRA/TSRA/IFR/LIFR LIKELY THROUGH MON NIGHT WITH
CONDITIONS IMPROVING TO WIDELY SCATTERED SHOWERS/TEMPO MVFR TUES.
VFR WED. CHANCE OF SHRA/TSRA/TEMPO MVFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM MONDAY...THE FRONT HAS MOVED LITTLE SINCE 3
AM...CROSSING THE COASTLINE NEAR HOLDEN BEACH AND SEPARATING NORTH
WINDS ALONG THE SOUTH CAROLINA BEACHES FROM SOUTH WINDS OVER CAPE
FEAR. THIS BOUNDARY WILL BE THE FOCUS FOR NEW SHOWERS AND TSTMS
TODAY. THIS UPDATE MAINLY ADDRESSES NEAR-TERM WIND DIRECTIONS AND
COVERAGE OF SHOWERS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
A STALLED FRONT SITS JUST OFF THE SOUTH CAROLINA COAST...BUT RUNS
INLAND ACROSS COASTAL SE NORTH CAROLINA. THIS FRONT IS PRODUCING A
VARIETY OF WIND DIRECTIONS...PREVAILING SOUTHEASTERLY ALONG THE
COAST EAST OF OAK ISLAND...AND PREVAILING NORTH TO NORTHEASTERLY
ALONG THE GRAND STRAND. THE BOUNDARY IS EXPECTED TO PUSH INLAND
LATE THIS MORNING WITH EAST TO SOUTHEASTERLY WINDS DEVELOPING
THROUGHOUT THE AREA.
TROPICAL STORM BERTHA WILL NOT DIRECTLY AFFECT THE AREA...BUT WILL
MAKE ITS CLOSEST APPROACH TO THE COASTAL WATERS EARLY THIS EVENING.
BERTHA SHOULD REMAIN SEVERAL HUNDRED MILES OFFSHORE...SENDING SWELLS
INTO THE AREA BUT LITTLE ELSE. NONE OF TODAY`S RAIN OR WIND CAN BE
ATTRIBUTED TO THE STORM. AS BERTHA MOVES NORTH OF OUR LATITUDE
TONIGHT THE FRONT SHOULD BE PULLED BACK OFFSHORE...WITH WIND
DIRECTIONS TENDING TO BACK MORE NORTHEASTERLY WITH TIME.
SEAS AVERAGE 4-5 FEET CURRENTLY...AND MAY BUILD TO A SOLID 5 FEET
TONIGHT AS SWELL FROM BERTHA IMPACTS THE WATERS. SOME MODELS ARE
HINTING AT SOME 6-FOOTERS GETTING INTO THE WATER NEAR CAPE FEAR AND
EAST OF WINYAH BAY.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...BERTHA SWELL TO BE RAMPING UP RIGHT AROUND THE
START OF THE PERIOD. BERTHA ACCELERATES BY LATE MONDAY INTO EARLY
TUESDAY WITH ITS CLOSEST APPROACH SOME 300+ MILES OFFSHORE. THE
SWELLS MAY BE SUFFICIENT TO BRING A FEW SMALL CRAFT ADVISORY-WORTHY
6 FT SEAS TO NORTHERN ZONES BUT THERE IS ANOTHER FEW MODEL CYCLES
AND NHC FORECASTS REMAINING TO CLEAR UP ANY UNCERTAINTY. ANOTHER
AREA OF LOW PRESSURE MOVING NE ALONG FRONTAL BOUNDARY LAGS BEHIND
BERTHA...BEING SHALLOWER AND THUS LESS ENTRENCHED IN THE DEEP LAYER
FLOW. THIS LOW WILL KEEP WINDS FAIRLY LIGHT AND GENERALLY
NE...SHIFTING TO NW TUESDAY NIGHT AS IT MOVES BY. ADDITIONAL VEERING
THEN SLATED FOR WEDNESDAY AS WIND SPEEDS DROP ABOUT A CATEGORY.
BACKSWELL DOES NOT APPEAR TO LINGER LONG ACCORDING TO GUIDANCE AS
SEAS QUICKLY SETTLE INTO THE 2 TO 3 FT RANGE.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...INLAND PIEDMONT TROUGH TAKES ON A MORE WEST-EAST
ORIENTATION AS THURSDAY PROGRESSES AND GROWS NEARER TO THE COAST.
THIS IS IN RESPONSE TO APPROACH OF A COLD FRONT FROM THE NORTH AND
WEST. THERE MAY BE A SMALL DIRECTION VARIATION AS THIS OCCURS BUT
MAIN EFFECT WILL BE A DECREASE IN SPEED DUE TO THE SLIGHTLY
SLACKENED GRADIENT. COLD FRONT MOVES THROUGH EARLY FRIDAY TURNING
WINDS ONSHORE AND POSSIBLY ADDING 5 KT TO OVERALL SPEEDS. OVERALL
INCREASE IN WAVE HEIGHTS SHOULD BE MINOR BUT THE ONSHORE FLOW
DIRECTION MAY DECREASE THE NEARSHORE/OFFSHORE GRADIENT IN WAVE SIZE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ017-023-
024-032-033.
FLOOD WATCH THROUGH THIS EVENING FOR SCZ053>056.
NC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NCZ087.
FLOOD WATCH THROUGH THIS EVENING FOR NCZ096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS BISMARCK ND
945 AM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 944 AM CDT MON AUG 4 2014
ONGOING CONVECTION SOUTHWEST OF THE MISSOURI RIVER IS ASSOCIATED
WITH AN SUBTLE UPPER LEVEL SHORTWAVE MOVING ACROSS THE STATE THIS
MORNING. RADAR DETECTED A STORM THAT WAS CAPABLE OF PRODUCING
SEVERE HAIL OVER EASTERN GRANT COUNTY ABOUT AN HOUR AGO.
HOWEVER...NO SEVERE REPORTS WERE RECEIVED. THESE STORMS ARE NOW
MOVING INTO CORSON COUNTY SOUTH DAKOTA AS OF THE TIME OF THIS
WRITING.
THE LATEST HRRR MAINTAINS CONVECTION OVER MOST OF SOUTHWESTERN AND
SOUTH CENTRAL NORTH DAKOTA THROUGH THE LATE MORNING HOURS...WITH
DECREASING THUNDERSTORM CHANCES DEVELOPING FROM WEST TO EAST THIS
AFTERNOON AS SUBSIDENCE DEVELOPS ON THE BACK SIDE OF THE
SHORTWAVE. KEPT THIS TREND GOING IN THE CURRENT FORECAST AND
UPDATED TO INCREASE MORNING POPS. ALSO REMOVED MORNING FOG WORDING
FROM THE ZONES. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 701 AM CDT MON AUG 4 2014
THE 00 UTC WRF-NMM AND ARW...06 UTC NAM AND 10 UTC HRRR HAVE A
GOOD HANDLE ON THE ONGOING CONVECTION ACROSS SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA...AND WILL FOLLOW THEIR SOLUTIONS FOR POPS
THE REMAINDER OF THE DAY. OVERALL...CONVECTIVE COVERAGE WILL BE
GREATEST THIS MORNING...BECOMING ISOLATED TO SCATTERED THROUGH THE
AFTERNOON AS UPPER LEVEL FORCING BECOMES MORE NEBULOUS. GIVEN
WEAK INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON AUG 4 2014
THE MAIN FORECAST PROBLEM WILL BE THE CONVECTIVE POTENTIAL
THROUGH THE PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE EXTENDED FROM WESTERN ONTARIO TO
EASTERN NORTH DAKOTA WHILE LOW PRESSURE CONTINUED TO DEEPEN OVER
WYOMING AND COLORADO. AT UPPER LEVELS...SHORTWAVES CONTINUE TO MOVE
THROUGH THE UPPER FLOW FROM SOUTHWESTERN CANADA ACROSS THE ROCKIES
AND INTO THE FRONT RANGE AND NORTHERN PLAINS STATES. ONE RELATIVELY
STRONG SHORTWAVE ENERGY VORT MAX WAS OVER EASTERN MONTANA...LIKELY
ASSOCIATED WITH A LINE OF THUNDERSTORMS BETWEEN GLASGOW AND
BILLINGS. THIS AREA OF CONVECTION HAS HELD TOGETHER AND CONTINUES TO
MOVE SOUTHEASTWARD. ANOTHER AREA OF CONVECTION BEGAN IN WESTERN
SOUTH DAKOTA LATE SUNDAY EVENING/EARLY MONDAY MORNING. A LOW LEVEL
JET FROM WESTERN AND CENTRAL SOUTH DAKOTA...TO SOUTH CENTRAL AND
WESTERN NORTH DAKOTA...TO EASTERN MONTANA IS LIKELY ASSOCIATED WITH
THE CONVECTION IN SOUTH DAKOTA. THERE WERE A COUPLE OF SMALL CELLS
THAT DEVELOPED OVER GOLDEN VALLEY AND SLOPE COUNTIES IN THE PAST
HOUR OR TWO.
THE COMBINATION OF THE APPROACHING UPPER LEVEL VORT MAX IMPULSE IN
EASTERN MONTANA...AND THE DEVELOPING LOW LEVEL JET OVER THE WESTERN
DAKOTAS AND EASTERN MONTANA...SHOULD AID IN DEVELOPMENT OF ELEVATED
SHOWERS AND THUNDERSTORMS BEFORE SUNRISE. THE MODELS INDICATE THE
UPPER LEVEL IMPULSE SPREADING SOUTHEAST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING...AND WEAKENING THIS AFTERNOON AS IT MOVES
SOUTHEAST TOWARDS EASTERN SOUTH DAKOTA. HAVE CHANCES OF
THUNDERSTORMS EARLY THIS MORNING WITH SCATTERED COVERAGE
EXPECTED...THEN BECOMING MORE ISOLATED IN NATURE BY AFTERNOON.
TONIGHT ANOTHER MORE VIGOROUS SET OF UPPER LEVEL IMPULSES EMANATING
FROM THE CENTRAL US ROCKIES IS FORECAST TO MOVE NORTHEASTWARD
ACROSS MONTANA AND WYOMING THIS AFTERNOON...REACHING SOUTHWESTERN
NORTH DAKOTA LATER THIS EVENING AND SPREADING TOWARDS CENTRAL NORTH
DAKOTA LATE MONDAY NIGHT. THE BEST CAPE/SHEAR COMBINATION TONIGHT IS
OVER MONTANA...WITH THE SURFACE HIGH FROM WESTERN ONTARIO NUDGING
FURTHER INTO EASTERN NORTH DAKOTA. THUS NOT EXPECTING SEVERE STORMS
TO REACH WESTERN NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON AUG 4 2014
THUNDERSTORM AND RAINFALL POTENTIAL WEST AND SOUTH CENTRAL TUESDAY
AND WEDNESDAY WILL HIGHLIGHT THE EXTENDED.
A CONSENSUS OF THE 00 UTC GLOBAL AND HIGH RESOLUTION GUIDANCE
PROPAGATES THE UPPER LEVEL LOW ACROSS SOUTHWEST ALBERTA TODAY INTO
EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE TUESDAY AND INTO
WEDNESDAY...WITH SURFACE HIGH PRESSURE ACROSS NORTHEAST NORTH
DAKOTA INTO THE UPPER MISSISSIPPI VALLEY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ACROSS
EASTERN MONTANA...PROPAGATING INTO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA BY LATE AFTERNOON/EARLY EVENING. RE-DEVELOPMENT IS FORECAST
FOR THESE AREAS AGAIN WEDNESDAY ALONG THE WESTERN PERIPHERY OF THE
SURFACE HIGH. OVERALL INSTABILITY IS WEAK...WITH LITTLE CHANCE FOR
SEVERE STORMS...IN LINE WITH THE SPC DAY 2 AND 3 OUTLOOKS. LOCALLY
HEAVY RAINFALL IS A POSSIBILITY WITH PWATS NEAR 1.50 INCHES AND
SLOW STORM MOTIONS WITH WEAK LOW TO MID LEVEL FLOW.
THEREAFTER...FOR WEDNESDAY THROUGH THE WEEKEND...NEAR ZONAL FLOW IS
FORECAST...FAVORING NEAR NORMAL TEMPERATURES AND SPORADIC
THUNDERSTORM CHANCES WITH WEAK IMPULSES EMBEDDED IN THE SOUTHERN
PERIPHERY OF THE UPPER JET.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 701 AM CDT MON AUG 4 2014
LIFR CONDITIONS IN STRATUS WILL CONTINUE AT KDIK THROUGH AT LEAST
15 UTC...SLOWING IMPROVING THEREAFTER. MVFR/IFR FOG WILL CONTINUE
AT KMOT THROUGH 14 UTC THIS MORNING. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL IMPACT KDIK AND KBIS THIS MORNING AND INTO THE
EARLY AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE AT KDIK AND
KBIS TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...JV
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
702 AM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 701 AM CDT MON AUG 4 2014
THE 00 UTC WRF-NMM AND ARW...06 UTC NAM AND 10 UTC HRRR HAVE A
GOOD HANDLE ON THE ONGOING CONVECTION ACROSS SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA...AND WILL FOLLOW THEIR SOLUTIONS FOR POPS
THE REMAINDER OF THE DAY. OVERALL...CONVECTIVE COVERAGE WILL BE
GREATEST THIS MORNING...BECOMING ISOLATED TO SCATTERED THROUGH THE
AFTERNOON AS UPPER LEVEL FORCING BECOMES MORE NEBULOUS. GIVEN
WEAK INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON AUG 4 2014
THE MAIN FORECAST PROBLEM WILL BE THE CONVECTIVE POTENTIAL
THROUGH THE PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE EXTENDED FROM WESTERN ONTARIO TO
EASTERN NORTH DAKOTA WHILE LOW PRESSURE CONTINUED TO DEEPEN OVER
WYOMING AND COLORADO. AT UPPER LEVELS...SHORTWAVES CONTINUE TO MOVE
THROUGH THE UPPER FLOW FROM SOUTHWESTERN CANADA ACROSS THE ROCKIES
AND INTO THE FRONT RANGE AND NORTHERN PLAINS STATES. ONE RELATIVELY
STRONG SHORTWAVE ENERGY VORT MAX WAS OVER EASTERN MONTANA...LIKELY
ASSOCIATED WITH A LINE OF THUNDERSTORMS BETWEEN GLASGOW AND
BILLINGS. THIS AREA OF CONVECTION HAS HELD TOGETHER AND CONTINUES TO
MOVE SOUTHEASTWARD. ANOTHER AREA OF CONVECTION BEGAN IN WESTERN
SOUTH DAKOTA LATE SUNDAY EVENING/EARLY MONDAY MORNING. A LOW LEVEL
JET FROM WESTERN AND CENTRAL SOUTH DAKOTA...TO SOUTH CENTRAL AND
WESTERN NORTH DAKOTA...TO EASTERN MONTANA IS LIKELY ASSOCIATED WITH
THE CONVECTION IN SOUTH DAKOTA. THERE WERE A COUPLE OF SMALL CELLS
THAT DEVELOPED OVER GOLDEN VALLEY AND SLOPE COUNTIES IN THE PAST
HOUR OR TWO.
THE COMBINATION OF THE APPROACHING UPPER LEVEL VORT MAX IMPULSE IN
EASTERN MONTANA...AND THE DEVELOPING LOW LEVEL JET OVER THE WESTERN
DAKOTAS AND EASTERN MONTANA...SHOULD AID IN DEVELOPMENT OF ELEVATED
SHOWERS AND THUNDERSTORMS BEFORE SUNRISE. THE MODELS INDICATE THE
UPPER LEVEL IMPULSE SPREADING SOUTHEAST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING...AND WEAKENING THIS AFTERNOON AS IT MOVES
SOUTHEAST TOWARDS EASTERN SOUTH DAKOTA. HAVE CHANCES OF
THUNDERSTORMS EARLY THIS MORNING WITH SCATTERED COVERAGE
EXPECTED...THEN BECOMING MORE ISOLATED IN NATURE BY AFTERNOON.
TONIGHT ANOTHER MORE VIGOROUS SET OF UPPER LEVEL IMPULSES EMANATING
FROM THE CENTRAL US ROCKIES IS FORECAST TO MOVE NORTHEASTWARD
ACROSS MONTANA AND WYOMING THIS AFTERNOON...REACHING SOUTHWESTERN
NORTH DAKOTA LATER THIS EVENING AND SPREADING TOWARDS CENTRAL NORTH
DAKOTA LATE MONDAY NIGHT. THE BEST CAPE/SHEAR COMBINATION TONIGHT IS
OVER MONTANA...WITH THE SURFACE HIGH FROM WESTERN ONTARIO NUDGING
FURTHER INTO EASTERN NORTH DAKOTA. THUS NOT EXPECTING SEVERE STORMS
TO REACH WESTERN NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON AUG 4 2014
THUNDERSTORM AND RAINFALL POTENTIAL WEST AND SOUTH CENTRAL TUESDAY
AND WEDNESDAY WILL HIGHLIGHT THE EXTENDED.
A CONSENSUS OF THE 00 UTC GLOBAL AND HIGH RESOLUTION GUIDANCE
PROPAGATES THE UPPER LEVEL LOW ACROSS SOUTHWEST ALBERTA TODAY INTO
EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE TUESDAY AND INTO
WEDNESDAY...WITH SURFACE HIGH PRESSURE ACROSS NORTHEAST NORTH
DAKOTA INTO THE UPPER MISSISSIPPI VALLEY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ACROSS
EASTERN MONTANA...PROPAGATING INTO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA BY LATE AFTERNOON/EARLY EVENING. RE-DEVELOPMENT IS FORECAST
FOR THESE AREAS AGAIN WEDNESDAY ALONG THE WESTERN PERIPHERY OF THE
SURFACE HIGH. OVERALL INSTABILITY IS WEAK...WITH LITTLE CHANCE FOR
SEVERE STORMS...IN LINE WITH THE SPC DAY 2 AND 3 OUTLOOKS. LOCALLY
HEAVY RAINFALL IS A POSSIBILITY WITH PWATS NEAR 1.50 INCHES AND
SLOW STORM MOTIONS WITH WEAK LOW TO MID LEVEL FLOW.
THEREAFTER...FOR WEDNESDAY THROUGH THE WEEKEND...NEAR ZONAL FLOW IS
FORECAST...FAVORING NEAR NORMAL TEMPERATURES AND SPORADIC
THUNDERSTORM CHANCES WITH WEAK IMPULSES EMBEDDED IN THE SOUTHERN
PERIPHERY OF THE UPPER JET.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 701 AM CDT MON AUG 4 2014
LIFR CONDITIONS IN STRATUS WILL CONTINUE AT KDIK THROUGH AT LEAST
15 UTC...SLOWING IMPROVING THEREAFTER. MVFR/IFR FOG WILL CONTINUE
AT KMOT THROUGH 14 UTC THIS MORNING. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL IMPACT KDIK AND KBIS THIS MORNING AND INTO THE
EARLY AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE AT KDIK AND
KBIS TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1058 AM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1053 AM CDT MON AUG 4 2014
HAVE UPDATED THE FORECAST TO BROADEN THE CHANCE OF THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING HOURS. COMPLEX OF STORMS ACROSS
NORTH CENTRAL SOUTH DAKOTA DRIFTING SOUTH SOUTH EAST. WHILE THE
BETTER JET DYNAMICS ARE ACROSS THE EASTERN HALF OF THE FORECAST
AREA...STORMS CONTINUE TO BUILD INTO AN UNSTABLE ENVIRONMENT. WITH
ELEVATED CAPE OF 1-2K...UPDATED THE HWO TO ADD MENTION OF HAIL.
SHEAR PROFILES ARE FAR FROM IDEAL...BUT STRONGEST STORMS THIS
AFTERNOON MAY APPROACH THE LOW END OF SEVERE WITH HAIL BEING THE
MAIN THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 623 AM CDT MON AUG 4 2014
TAF PERIOD BEGINS WITH PATCHY MVFR VISIBILITY IN BR...WITH VERY
LOCALIZED IFR-LIFR VISIBILITY...BUT CONDITIONS EXPECTED TO IMPROVE
RAPIDLY WITH VFR CONDITIONS THEN EXPECTED TO PREVAIL. SHOWERS AND
THUNDERSTORMS WILL AGAIN BECOME ISOLATED TO SCATTERED THROUGHOUT THE
REGION BY MID TO LATE MORNING...WITH ACTIVITY WANING BY SUNSET. KHON
AND KFSD MORE LIKELY TO SEE A BRIEF THUNDER THREAT DURING THE LATE
MORNING THROUGH MID AFTERNOON...BUT DUE TO EXPECTED SPOTTY COVERAGE
OF TSRA...HAVE NOT INCLUDED MENTION IN TAFS AT THIS TIME. SCATTERED
TSRA EXPECTED TO SPREAD BACK INTO THE REGION FROM THE SOUTHWEST AFTER
04Z TONIGHT...POSSIBLY REACHING TAF LOCATIONS AFTER 08Z TUESDAY.
HOWEVER AGAIN WITH UNCERTAINTY IN TIMING/COVERAGE...OPTED TO LEAVE
MENTION OUT OF THIS TAF SET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JH
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
623 AM CDT MON AUG 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 623 AM CDT MON AUG 4 2014
TAF PERIOD BEGINS WITH PATCHY MVFR VISIBILITY IN BR...WITH VERY
LOCALIZED IFR-LIFR VISIBILITY...BUT CONDITIONS EXPECTED TO IMPROVE
RAPIDLY WITH VFR CONDITIONS THEN EXPECTED TO PREVAIL. SHOWERS AND
THUNDERSTORMS WILL AGAIN BECOME ISOLATED TO SCATTERED THROUGHOUT THE
REGION BY MID TO LATE MORNING...WITH ACTIVITY WANING BY SUNSET. KHON
AND KFSD MORE LIKELY TO SEE A BRIEF THUNDER THREAT DURING THE LATE
MORNING THROUGH MID AFTERNOON...BUT DUE TO EXPECTED SPOTTY COVERAGE
OF TSRA...HAVE NOT INCLUDED MENTION IN TAFS AT THIS TIME. SCATTERED
TSRA EXPECTED TO SPREAD BACK INTO THE REGION FROM THE SOUTHWEST AFTER
04Z TONIGHT...POSSIBLY REACHING TAF LOCATIONS AFTER 08Z TUESDAY.
HOWEVER AGAIN WITH UNCERTAINTY IN TIMING/COVERAGE...OPTED TO LEAVE
MENTION OUT OF THIS TAF SET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
601 AM CDT MON AUG 4 2014
.AVIATION...
/12Z TAFS/
VFR conditions are expected to prevail today and tonight at
the TAF sites. Expect a cumulus field to develop across our
eastern and central counties late this morning and afternoon.
There is a slight chance of showers and thunderstorms across
the area generally southeast of a Sonora to Lake Brownwood
line this afternoon and evening. With the low anticipated
coverage however, not including a mention in the TAFs at
this time. Any lingering convection will dissipate by sunset,
with clear to partly cloudy skies expected overnight. Winds
will be from the east or east-northeast at 5-10 KT today, and
from the east-southeast at decreased speeds tonight.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT MON AUG 4 2014/
SHORT TERM...
(Today and Tonight)
A weak lower to mid-level disturbance along the Texas coast will
move to the southwest today, while the upper ridge remains in
place from northern Mexico and the Texas Big Bend region north
into the central Rockies.
As the disturbance moves southwest today, associated lower to
mid-level moisture will move west into our area. The combination
of surface heating, moisture increase and marginally sufficient
destabilization could allow isolated or widely scattered showers
and thunderstorms to develop over our east-central and
southeastern counties, mainly during the afternoon. The 00Z GFS,
TTU WRF and HRRR models indicate this potential. Carrying a slight
chance PoP for the area southeast of a Sonora to Eden to Lake
Brownwood line. Have a lingering slight chance PoP this evening
until 9 PM for nearly the same area. This convection will be
diurnally driven and dissipate by sunset, with clear to partly
cloudy skies expected overnight.
The 850mb temperatures increase only slightly today, mainly across
the western part of our area. With this indication and an
anticipated increase in cloud cover, going with highs about the
same as yesterday across our eastern and central counties, and
around a degree warmer in our western counties. Lows tonight are
expected to be mostly in the upper 60s.
LONG TERM...
(Tuesday through Sunday)
The subtropical ridge axis currently runs in a general north-south
orientation along the front range, but will flatten over the
next few days as the large trough over the Great Basin ejects
shortwave energy over the crest of the ridge. Despite unimpressive
500 mb heights of 591-594 dam, a strong thermal ridge will reside
in the 850-700 mb layer, pushing temperatures well into the 90s
areawide, potentially reaching triple digits later this week. Min
temps will increase as well, with mid 70s anticipated by Thursday
morning. The general pattern will be an afternoon cumulus field
with clearing skies during the evening and overnight hours. Rain
chances will remain minimal due to the presence of the ridge and
dearth of deep moisture. That said, if any precipitation does
occur Tuesday through Thursday, it would more than likely be on
Tuesday afternoon.
The ECMWF and GEM are bringing a cold front south on Friday,
stalling the boundary in the vicinity of the Red River. The GFS,
however, maintains southerly flow well into the central plains. If
this boundary does verify, we`ll likely have to consider at
least a mention of isolated showers and thunderstorms Friday and
Saturday afternoon, despite the ridge being overhead. That said,
the juxtaposition of the front and the ridge appears unlikely.
Otherwise, expect the hot and generally dry conditions to
continue.
As we move through the weekend, both the GFS and ECMWF and ECMWF
are hinting that a TUTT low will develop and move across the
western Gulf of Mexico into south TX. With the upper-level ridge
centered over the region, this TUTT is likely to remain well to
our south, generally to far away to have much of an effect. If the
ridge is a bit weaker, this feature could yield isolated
convection Sunday into Monday. However, at this time, confidence is
far too low to include a mention in the forecast.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 69 94 73 97 / 5 10 5 5 5
San Angelo 93 68 95 71 98 / 5 10 5 5 5
Junction 92 69 94 72 96 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Aviation and Short Term: 19
Long Term: Johnson
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
942 AM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EDT MONDAY...
FOG WILL CONTINUE TO ERODE THIS MORNING. MORNING SOUNDINGS SHOWING
ONLY A NARROW REGION ON MOISTURE AT OR BELOW 850 MB. ABOVE
THAT...VERY DRY AIR WAS IN PLACE. EXPECT MIXING TO CONTINUE TO
TAKE PLACE THIS MORNING WITH ANY REMAINING FOG DISSIPATED BY 1100
AM. REMAINDER OF THE FORECAST STILL LOOKS ON TRACK BASED UPON THE
EARLIER DISCUSSION.
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...
SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWED AREAS OF MVFR
TO IFR FOG IN THE NEW AND GREENBRIER RIVER VALLEYS AND SOME FOG
AND STRATUS IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA. BUFKIT
SOUNDINGS INDICATED THE LAYER OF MOISTURE WAS SHALLOW. EXPECTING
THE FOG TO DISSIPATE BY MID MORNING. HIGH CONFIDENCE THAT
CONDITIONS WILL BE VFR BY 14Z/10AM.
MOSTLY LIGHT/VARIABLE THROUGH TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON...AS EAST LOW LEVEL
WINDS CREATE SOME CONVERGENCE NEAR THE BLUE RIDGE. THE CHANCE IS
TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
FOG IS EXPECTED TO DEVELOP AGAIN OVERNIGHT IN TYPICAL LOCATIONS.
MODERATE TO HIGH CONFIDENCE THAT VISIBILITY WILL LOWER TO AT LEAST
MVFR AT KLYH/KBCB AND KLWB AFTER MIDNIGHT.
EXTENDED AVIATION DISCUSSION...
A COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH SHOWER AND SOME THUNDERSTORMS IN ASSOCIATION WITH THE COLD
FRONT. LIKEWISE...MORE OVERNIGHT SUB- VFR CONDITIONS ARE LIKELY
WITH BOUNDARY LAYER MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. IF THERE IS LIMITED MOVEMENT OF THE FRONT BY
FRIDAY...EXPECT SIMILAR CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
738 AM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...
SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWED AREAS OF MVFR
TO IFR FOG IN THE NEW AND GREENBRIER RIVER VALLEYS AND SOME FOG
AND STRATUS IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA. BUFKIT
SOUNDINGS INDICATED THE LAYER OF MOISTURE WAS SHALLOW. EXPECTING
THE FOG TO DISSIPATE BY MID MORNING. HIGH CONFIDENCE THAT
CONDITIONS WILL BE VFR BY 14Z/10AM.
MOSTLY LIGHT/VARIABLE THROUGH TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON...AS EAST LOW LEVEL
WINDS CREATE SOME CONVERGENCE NEAR THE BLUE RIDGE. THE CHANCE IS
TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
FOG IS EXPECTED TO DEVELOP AGAIN OVERNIGHT IN TYPICAL LOCATIONS.
MODERATE TO HIGH CONFIDENCE THAT VISIBILITY WILL LOWER TO AT LEAST
MVFR AT KLYH/KBCB AND KLWB AFTER MIDNIGHT.
EXTENDED AVIATION DISCUSSION...
A COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH SHOWER AND SOME THUNDERSTORMS IN ASSOCIATION WITH THE COLD
FRONT. LIKEWISE...MORE OVERNIGHT SUB- VFR CONDITIONS ARE LIKELY
WITH BOUNDARY LAYER MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. IF THERE IS LIMITED MOVEMENT OF THE FRONT BY
FRIDAY...EXPECT SIMILAR CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST MON AUG 4 2014
.SYNOPSIS...
A STRONG UPPER LOW WILL EXIT THE REGION BY TONIGHT...BUT LINGERING
MOISTURE WILL STILL PROVIDE CHANCES FOR LATE MORNING AND AFTERNOON
SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN EAST OF PHOENIX.
A SIGNIFICANT DRYING TREND WILL OVERSPREAD THE REGION BEGINNING
TONIGHT ESSENTIALLY CUTTING OFF ANY STORM CHANCES FOR TUESDAY
THROUGH THURSDAY. A GRADUAL RETURN OF STORM CHANCES FROM EAST TO
WEST IS THEN EXPECTED TO BEGIN BY THE END OF THE WEEK...LIKELY
CONTINUING INTO THE UPCOMING WEEKEND.
&&
.DISCUSSION...
A MUCH QUIETER SCENE ACROSS OUR CWA THIS MORNING WHEN COMPARED TO
ALL OF THE CONVECTIVE ACTIVITY WE SAW YESTERDAY...AS THE UPPER LOW
THAT TRIGGERED ALL THESE STORMS CONTINUES TO MOVE OFF WELL TO OUR
NORTH...AND IS NOW OVER CENTRAL NV. DEEP SOUTHWESTERLY FLOW BEHIND
THIS LOW CENTER HAS PULLED DRIER AIR INTO THE REGION...AND CLEARED
SKIES OVER MOST AREAS. THE ONLY AREAS THAT ARE NOW SEEING CLOUDS ON
THE LATEST SATELLITE IMAGERY ARE OVER GILA COUNTY AND POINTS EAST
AND ACROSS SW CA...WHERE A WEAK SHORTWAVE ROTATING AROUND THE
DEPARTING UPPER LOW CENTER IS PROVIDING SOME WEAK LIFT. ALTHOUGH THE
LATEST RUN OF THE HRRR HIGH-RES MODEL CONTINUES TO SHOW THE
DEVELOPMENT OF ISOLATED TO SCATTERED SHOWER/TS ACTIVITY OVER GILA
COUNTY AND SE CA FOR A BRIEF PERIOD THIS AFTERNOON...HAVE DECIDED TO
REDUCE POPS A BIT OVER BOTH LOCATIONS SINCE THE LATEST GFS FCST
SOUNDINGS CONTINUE TO SHOW CONTINUED DRYING/STABILIZATION THROUGH
THE COLUMN THROUGH THE REST OF TODAY. OTHER THAN THE AFOREMENTIONED
CHANGES AND SOME MINOR ADJUSTMENTS TO DEWPOINT AND HOURLY
TEMPERATURE TRENDS...CURRENT GRIDDED FCSTS ARE STILL LOOKING
GOOD...AND NO FURTHER UPDATES ARE PLANNED AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
THE UNSEASONABLY POTENT UPPER LOW THAT ALLOWED FOR WIDESPREAD STORM
ACTIVITY ON SUNDAY CONTINUES TO PROGRESS TO THE NORTH WITH THE LOW
CENTER NOW IN SOUTHERN NEVADA. SOUTHWESTERLY FLOW BEHIND THE LOW HAS
ALLOWED FOR SIGNIFICANT DRYING ALOFT ACROSS SOUTHWEST AND PORTIONS
OF SOUTH-CENTRAL ARIZONA. DEEPER MOISTURE REMAINS ACROSS EASTERN
ARIZONA EARLY THIS MORNING WITH A LINE OF SHOWERS AND THUNDERSTORMS
STILL ONGOING. RESIDUAL LOW LEVEL MOISTURE IN COMBINATION WITH THE
CLOSER PROXIMITY TO THE UPPER LOW CENTER MAY ALLOW FOR SOME
CONTINUED ISOLATED SHOWERS AND MAYBE A THUNDERSTORM ACROSS RIVERSIDE
COUNTY CALIFORNIA THROUGH EARLY AFTERNOON. EXPECTING BOUNDARY LAYER
MOISTURE TO BE SCOURED OUT FROM WEST TO EAST STARTING THIS
AFTERNOON...BUT SOME LINGERING MOISTURE SHOULD REMAIN ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX. HAVE KEPT CHANCE POPS FOR THIS
AFTERNOON ACROSS SOUTHERN GILA COUNTY AS SUFFICIENT MOISTURE WILL
REMAIN IN PLACE.
FOR TUESDAY THROUGH THURSDAY SOUTHWESTERLY DRY FLOW WILL DOMINATE
WITH PRECIPITABLE WATER VALUES DROPPING TO BELOW AN INCH AND
POSSIBLY EVEN BELOW A HALF AN INCH ACROSS OUR WESTERN ZONES. THE
SYNOPTIC FLOW PATTERN ALLOWING FOR THE SOUTHWESTERLY FLOW WILL BE
THE RESULT OF THE NEARLY STATIONARY SUBTROPICAL HIGH CENTER OVER
NORTHERN MEXICO AND PERSISTENT BROAD TROUGHING ACROSS CALIFORNIA
INTO THE GREAT BASIN. MAY SEE AN ISOLATED SHOWER OR THUNDERSTORM
ACROSS FAR EASTERN GILA COUNTY DURING THE PERIOD...SO HAVE KEPT
AFTERNOON LOW END SLIGHT CHANCE POPS GOING. TEMPERATURES FOR THE
PERIOD WILL REMAIN NEAR SEASONAL NORMALS AS HEIGHTS BARELY BUDGE.
THE BROAD TROUGHING TO OUR NORTHWEST SHOULD KEEP TEMPERATURES FROM
RISING AT LEAST THROUGH THE END OF THE WEEK.
MODEL DIFFERENCES CAN BE SEEN STARTING FRIDAY INTO THE COMING WEEKEND
AS THE GFS BEGINS TO SHIFT LOW LEVEL WINDS TO MORE OF A
SOUTHEASTERLY DIRECTION WHEREAS THE EUROPEAN KEEPS DRY SOUTHWESTERLY
FLOW. DON/T HAVE MUCH FAITH IN THE DRY EUROPEAN SOLUTION AS EARLIER
MODEL RUNS SHOWED MOISTURE SEEPING INTO SOUTH-CENTRAL ARIZONA
STARTING FRIDAY ALONG WITH THE GFS. BELOW NORMAL CLIMO POPS ARE IN
THE FORECAST FOR FRIDAY AND SATURDAY...BUT SLIGHT CHANCES ARE
SOMEWHAT EXTENDED INTO THE LOWER DESERTS. WILL HAVE TO WAIT FOR
FURTHER MODEL RUNS TO GET A CLEARER SIGNAL ON WHEN MOISTURE WILL
RETURN. BOTH THE GFS AND THE EUROPEAN SHOW THE SUBTROPICAL HIGH
SHIFTING NORTHWARD INTO THE FOUR CORNERS REGION SOME TIME AROUND
SUNDAY INTO EARLY NEXT WEEK INCREASING HEIGHTS AND PROVIDING A MORE
FAVORABLE FLOW TO BRING IN AT LEAST SOME MOISTURE FROM MEXICO.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
NO AVIATION IMPACTS ANTICIPATED THROUGH MONDAY NIGHT AS THUNDERSTORM
ACTIVITY SHOULD REMAIN WELL NORTH AND EAST OF TERMINALS...AND ONLY
OCCASIONAL FEW-SCT CLOUDS AOA 9K FT. WITH NO OUTFLOW WINDS TO
CONTEND WITH...SPEEDS WILL BE GENERALLY AOB 8KT AND DIRECTIONAL
CHANGES POTENTIALLY LEADING TO PERIODS OF NEARLY CALM OR VARIABLE
SFC WINDS.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL...AND
KBLH...
MOSTLY CLEAR SKIES THROUGH MONDAY NIGHT WITH NO AVIATION IMPACTS.
SFC WINDS WILL GENERALLY PREVAIL WITH A WLY OR SLY COMPONENT...AND A
FEW GUSTS ABOVE 15KT MAY BE POSSIBLE LATE AFTERNOON AND EARLY
EVENING WITH PERIODS OF VARIABLE LIGHT SFC WINDS LATE NIGHT THOUGH
MORNING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
PREDOMINANTLY DRY WEATHER DURING THE MIDDLE OF THE WEEK WILL ONLY
GIVE WAY TO SLIGHTLY INCREASED CHANCES OF RAIN BY THE WEEKEND. THE
DRY AIR IN PLACE WILL RESULT IN AFTERNOON MINIMUM HUMIDITY VALUES IN
THE TEENS AT LOWER ELEVATIONS AND 20 TO 30 PERCENT IN THE
MOUNTAINS...WITH SOME TREND FOR MORE MOIST CONDITIONS LATER IN THE
PERIOD. OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. WINDS SHOULD
NOT BE A LARGE PROBLEM...THOUGH LOCAL GUSTS ASSOCIATED WITH ANY
THUNDERSTORMS WILL BE POSSIBLE BY THE WEEKEND TIME FRAME.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/KUHLMAN
AVIATION....MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS PUEBLO CO
258 PM MDT MON AUG 4 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 213 PM MDT MON AUG 4 2014
.CURRENTLY...STORMS HAVE DEVELOPED OVER THE SOUTHWEST MOUNTAINS
AND EASTERN MOUNTAINS THIS AFTERNOON. STORMS HAVE BEEN PRODUCING
SOME LOCALLY HEAVY DOWNPOURS...WITH THE MAIN CONCERN BEING FOR
THE STORMS TO MOVE SLOWLY OVER THE AREA BURN SCARS. SATELLITE
SOUNDER DATA AND MODELS CONTINUE TO MOIST ATMOSPHERE WITH
PRECIPITABLE WATERS MOSTLY RANGING FROM 0.75 TO ONE INCH OVER THE
MOUNTAINS AND HIGH VALLEYS TO AROUND AN INCH ON THE PLAINS.
.TONIGHT...HRRR AND 4KM NAM MODELS CONTINUE TO SUGGEST THE FIRST
ROUND OF CONVECTION MOVING OFF OF THE MOUNTAINS IT THE LATER
AFTERNOON AND EARLY EVENING. MODELS AND BUFKIT SOUNDINGS CONTINUE
TO SHOW WEAK INSTABILITY ON THE PLAINS THIS EVENING...BECOMING
MORE CAPPED FURTHER EAST. CONVECTION SHOULD WEAKEN AS IT MOVES
EAST DURING THE EVENING...AND MAINTAINED THE SILENT POPS NEAR THE
KANSAS BORDER. HRRR SUGGESTS THE NEXT DISTURBANCE...AS SEEN IN
CONVECTION OVER NORTHWEST NEW MEXICO...WILL PASS MOVE NORTHEAST
ACROSS THE CWA DURING THE EVENING REACHING THE EASTERN MOUNTAINS AFTER
MIDNIGHT. SUSPECT ATMOSPHERE WILL BE STABLE BY MIDNIGHT...AND
ONLY MAINTAINED POPS OVER THE WESTERN MOUNTAINS AT 06Z.
.TUESDAY...PORTION OF SHORTWAVE SPINNING OVER NEVADA WILL CROSS
THE CWA DURING THE AFTERNOON. PRECIPITABLE WATER VALUES WILL
REMAIN AROUND AN INCH OVER THE MAINS AND 0.75 TO ONE INCH OVER
THE MOUNTAINS. WITH THE SHORTWAVE APPROACHING...STORMS WILL
DEVELOP AN HOUR TO TWO EARLIER THAN MONDAY. MAIN THREATS AGAIN
WILL BE LOCALLY HEAVY DOWNPOURS..ESPECIALLY ON AREA BURN SCARS.
WINDS ALOFT WILL INCREASE SO STORMS WILL BE MOVING SLIGHTLY
FASTER. BEHIND THE TROUGH...DRYING OCCURS IN THE MID AND UPPER
LEVELS BY LATER AFTERNOON. -PGW--
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 213 PM MDT MON AUG 4 2014
TUE NIGHT...
DISTURBANCE ALOFT SHOULD BE OVER EASTERN PLAINS WITH DRIER AIR
GRADUALLY MOVING INTO THE MTNS. BEST CHANCE OF PRECIP WILL BE OVER
THE FAR E PLAINS DURING THE EVENING...WITH ISOLD POPS (AT BEST) OVER
THE CONTDVD.
WED...
SHOULD BE A RATHER DRY DAY AS DRIER AIR IS FCST TO BE OVER THE MTNS
WITH THE DRIER ATMOSPHERE CREEPING INTO THE PLAINS. IN
ADDITION...RIDGING AT MIDLVLS WILL BE OCCURRING OVER THE REGION.
BELIEVE POPS THIS DAT WILL BE ISOLD AT BEST...AND WILL BE OVER THE
HIGHEST TRRN. MAX TEMPS THIS DAY WILL BE WARM WITH HIGHS IN THE 90S
MOST OF THE PLAINS.
THU...
THIS DAY WILL BE TRICKY. A COOL FRONT WILL MOVE ACROSS THE PLAINS
EARLY IN THE DAY. CONVECTION WILL FIRE ACROSS THE HIGH PLAINS...BUT
HOW FAR SOUTH WILL IT GET? GFS IS FARTHEST NORTH WITH BRUNT OF
ACTIVITY OVER FAR NE CO...WHILE NAM AND EC ARE A BIT FARTHER SOUTH
WITH THE ACTIVITY EXTENDING DOWN INTO EAST CENTRAL CO. FOR NOW HAVE
PAINTED ISOLD POPS OVER THE ENTIRE REGION DURING THE AFTERNOON AND
EVENING...BUT MAY NEED HIGHER POPS OVER THE FAR E PLAINS IN LATER
UPDATES. MAX TEMPS ON THE PLAINS SHOULD BE AROUND 90F THIS DAY.
MTNS SHOULD SEE ONLY ISOLD POPS.
FRI...
EC AND GFS IN DISAGREEMENT THIS DAY. BOTH BRING DOWN ANOTHER
BOUNDARY WITH UPSLOPE FLOW. GFS APPEARS MORE STABLE AND KEEPS WX
DRIER OVER OUR REGION WHILE EC A BIT MORE WETTER OVER THE FAR E
PLAINS. FOR NOW KEPT ONLY ISOLD POPS OVER E PLAINS WITH ISOLD PRECIP
OVER S MTN TOPS. REST OF MTNS DRY. MAX TEMPS ONCE AGAIN ABOUT 90F
MOST OF PLAINS.
WEEKEND...
SIMULATIONS SHOW A BIT BETTER CHANCE OF PRECIP ALL AREAS AS MONSOON
PLUME WILL LIKELY REDEVELOP OVER THE SW...WITH MOISTURE ADVECTING IN
FROM E AZ AND W NM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 213 PM MDT MON AUG 4 2014
THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE TAF SITES
UNTIL EARLY EVENING. ANOTHER DISTURBANCE MOVING ACROSS THE REGION
COULD MAINTAIN SOME SHOWERS WELL INTO THE EVENING OVER THE
MOUNTAINS AND HIGH VALLEYS. ON TUESDAY...AN APPROACHING
DISTURBANCE WILL HELP DEVELOP CONVECTION AN HOUR OR TWO EARLIER
THAN ON MONDAY...WITH THE POTENTIAL FOR STORMS NEAR KALS BEFORE
18Z. STORMS WILL SPREAD INTO KPUB AND KCOS BY EARLY AFTERNOON.
LOCALLY HEAVY RAIN WILL BE MAIN THREATS WITH CONVECTION WITH
REDUCED CEILINGS AND VISIBILITIES POSSIBLE. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PGW
LONG TERM...HODANISH
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1200 PM MDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1158 AM MDT MON AUG 4 2014
THUNDERSTORMS ARE STARTING TO DEVELOP OVER THE CONTINENTAL DIVIDE.
PLENTY OF MONSOON MOISTURE MOVING NORTHWARD AHEAD OF THE
DISTURBANCE IN ARIZONA AND UTAH. ALL SHORT RANGE MODELS SHOW THE
STORMS...WHICH ARE JUST DEVELOPING OVER THE CONTINENTAL DIVIDE
REGION...SHOULD MOVE EASTWARD IN THE AFTERNOON. MODELS CONTINUE TO
AGREE ON THE FIRST ROUND OF THUNDERSTORMS BEING OVER THE EASTERN
MOUNTAINS AND NEARBY PLAINS BY AROUND 2PM...AND CONTINUING TO
6PM. PLENTY OF MOISTURE REMAINS OVER THE REGION WITH MODELS
SUGGESTING PRECIPITABLE WATERS AROUND AN INCH OVER THE PLAINS AND
MUCH OF THE INTERSTATE 25 CORRIDOR. STORMS OVER WESTERN COLORADO
ARE MOVING AROUND 20 KNOTS. MAIN THREAT FOR FLASH FLOODING WILL BE
OVER THE AREA BURN SCARS...WHERE LOCALLY HEAVY DOWNPOURS COULD
RESULT IN FLASH FLOODING. LATEST MODELS AND BUFKIT SOUNDING
SUGGEST THE STORMS COULD MOVE EASTWARD OFF OF THE MOUNTAINS AND
ONTO THE EASTERN PLAINS DURING THE LATE AFTERNOON AND INTO THE
EVENING. EXTENDED THE EASTWARD EXTENT OF POPS THIS EVENING...BUT
HAVE ONLY SILENT POPS IN COUNTIES NEAR THE KANSAS BORDER.
A SECOND DISTURBANCE WILL MOVE ACROSS THE MOUNTAINS DURING THE
EVENING. THIS COULD KEEP SOME SHOWERS AND STORMS CONTINUING OVER
THE MOUNTAINS WELL INTO THE EVENING. WILL HAVE TO WATCH FOR
LOCALLY HEAVY DOWNPOURS WITH FLASH FLOODING OVER THE BURN SCARS
INT HE EVENING...BUT SUSPECT THREAT IS LESS THAN DURING THE
AFTERNOON BECAUSE OF THE INCREASED STABILITY FROM EARLIER STORMS.
ON TUESDAY...MAIN DISTURBANCE WILL PASS OVER THE CWA DURING THE
LATE MORNING AND INTO THE AFTERNOON. STORMS COULD BEGIN EARLIER
TOMORROW. STORMS COULD PRODUCE LOCALLY HEAVY DOWNPOURS...WHICH
WILL CAUSE FLASH FLOODING CONCERNS FOR AREA BURN SCARS. DRIER AIR
WILL MOVE INTO THE REGION FROM THE WEST...WHICH COULD END
CONVECTION EARLIER TOMORROW. --PGW--
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM MDT MON AUG 4 2014
AN UPR RIDGE WL REMAIN OVR THE AREA TODAY...BUT WL SHIFT A LITTLE
EASTWARD TONIGHT AS A SHORTWAVE TROF MOVES INTO UT AND WRN CO. THE
HRRR AND WRF SHOW PCPN MOVING OVR THE SAN JUAN AND LA GARITA MTN
AREAS THIS MORNING AND POSSIBLY INTO THE CENTRAL MTNS. RADAR LOOP
SHOWS ECHOES OVR WRN CO THIS MORNING...SO THAT SEEMS REASONABLE.
AROUND NOON...THE WRF AND HRRR DEVELOP SOME VERY ISOLD PCPN OVR SOME
OF THE ERN MTNS. THE MODELS THEN INCREASE PCPN COVERAGE OVR ALL THE
MTNS AREAS THRU THE AFTERNOON HOURS...WITH SOME PCPN ALSO SPREADING
OVR THE SAN LUIS VALLEY. IN THE LATE AFTERNOON...THEY SHOW SOME
ISOLD PCPN MAKING OVR PORTIONS OF THE I-25 CORRIDOR...MAINLY OVR EL
PASO COUNTY AND OVR HUERFANO AND WRN LAS ANIMAS COUNTIES. IN THE
EVENING HOURS THE NAM12 MOVES A LINE OVR PCPN EASTWARD ACRS THE SERN
PLAINS...WHILE THE WRF AND RAP MAINLY JUST KEEPS SOME ISOLD PCPN
WEST OF A LINE FROM CROWLEY...OTERO AND ERN LAS ANIMAS COUNTIES.
HAVE DECIDED TO NOT FOLLOW THE NAMS SOLUTION AND WL THEREFORE KEEP
THE FAR SERN PLAINS DRY. MUCH OF THE PCPN THEN DIES OFF BEFORE
MIDNIGHT...BUT THEN AS A SHORTWAVE TROF MOVES INTO WRN CO LATE
TONIGHT...INCREASED PCPN CHANCES ARE AGAIN EXPECTED OVR THE SWRN
MTNS. HIGH TEMPS TODAY SHOULD BE AROUND TO JUST SLIGHTLY BELOW
AVERAGE IN MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM MDT MON AUG 4 2014
TUESDAY-TUESDAY NIGHT...GENERALLY WEAK WESTERLY FLOW ALOFT PROGGED
ACROSS THE REGION TUESDAY WITH A MINOR EMBEDDED SHORT WAVE
TRANSLATING THROUGH THE FLOW. LATEST MODELS REMAIN CONSISTENT WITH
DRIER AIR EMBEDDED WITHIN THE WESTERLY FLOW ALOFT SLOWLY FILTERING
ACROSS THE AREA TUESDAY...WITH PWATS PROGGED BETWEEN 1/2 INCH ACROSS
WESTERN COLORADO TO AROUND 1 1/4 INCHES ACROSS THE FAR SE PLAINS.
DESPITE THE DRYING ALOFT...SHOULD SEE SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOPING ACROSS THE HIGHER TERRAIN LATE TUESDAY
MORNING WITH INCREASED UVV ASSOCIATED WITH THE PASSING WAVE. STORMS
TO SPREAD EAST ACROSS THE ADJACENT PLAINS AND INTO THE FAR SE PLAINS
THROUGH THE AFTERNOON AND EVENING HOURS. LOCALLY HEAVY RAIN TO
REMAIN POSSIBLE...ALONG WITH POSSIBLE FLASH FLOODING IF THESE STORMS
MOVE OVER AREA BURN SCARS. TEMPERATURES AT OR SLIGHTLY COOLER THAN
SEASONAL AVERAGES CAN BE EXPECTED WITH THE EXPECTED CONVECTIVE CLOUD
COVER.
WEDNESDAY-THURSDAY NIGHT...WEAK TO MODERATE WEST TO SOUTHWEST FLOW
ALOFT CONTINUES ACROSS THE AREA WEDNESDAY AND THURSDAY AS ANOTHER
EMBEDDED SHORT WAVE TRANSLATES ACROSS THE GREAT BASIN AND INTO THE
NORTHERN ROCKIES. DRIER AIR ALOFT CONTINUES TO MOVE INTO THE STATE
WITH MODEL SOUNDINGS INDICATING DEW PTS MIXING OUT INTO THE UPPER
30S AND UPPER 40S ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS AND
REMAINING GENERALLY IN THE 50S ACROSS THE FAR SE PLAINS. THERE IS
ENOUGH MOISTURE REMAINING IN PLACE TO WORK WITH LATE SUMMER SUNSHINE
FOR ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS BOTH DAYS...WITH THE BEST COVERAGE OVER AND NEAR THE
HIGHER TERRAIN. A WEAK COLD FRONT PROGGED TO BACK INTO EASTERN
COLORADO WEDNESDAY MORNING...LOOKS TO HAVE LITTLE AFFECT ON
TEMPERATURES WITH READINGS AROUND SEASONAL AVERAGES EXPECTED. LATEST
MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ELEVATED CONVECTION
ACROSS THE FAR SE PLAINS INTO WESTERN KANSAS THURSDAY EVENING AND
HAVE KEPT SLIGHT POPS IN TACT.
FRIDAY-SUNDAY...UPPER RIDGING BUILDS BACK ACROSS THE STATE WITH
MONSOONAL PLUME SLOWLY INCREASING ACROSS THE AREA. THIS...ALONG WITH
ANOTHER POSSIBLE WEAK COLD FRONT SLIDING ACROSS THE EASTERN
PLAINS...WILL ALLOW FOR INCREASING COVERAGE OF STORMS INTO NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1158 AM MDT MON AUG 4 2014
CONVECTION WILL DEVELOP OVER THE MOUNTAINS DURING THE EARLY
AFTERNOON AND MOVE INTO THE INTERSTATE 25 CORRIDOR BY LATE IN THE
AFTERNOON. ADD VCTS TO REMAINING TAFS FOR THIS AFTERNOON AND EARLY
EVENING TO ACCOUNT FOR SCATTERED COVERAGE OF CONVECTION. A SECOND
DISTURBANCE WILL PASS OVER THE REGION DURING THE EVENING. GIVEN
ATMOSPHERE WILL BE MORE STABLE...ONLY ADDED SOME VCSH TO
TAFS...AS BELIEVE THREAT FOR THUNDERSTORMS WILL BE LOW. ON
TUESDAY...A DISTURBANCE WILL APPROACH THE REGION BY LATE
MORNING...WITH AN EARLIER START FOR DIURNAL CONVECTION. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PGW
SHORT TERM...28
LONG TERM...MW
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
115 PM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING AND DURATION OF TSRA/SHRA IMPACTING THE TERMINALS THIS AFTERNOON.
* SECOND PERIOD OF SHRA/TSRA OVERNIGHT.
* W-SW WINDS BECOMING NE-E THIS AFTERNOON WITH COMBINED COLD
FRONT/LAKE BREEZE
ED F
//DISCUSSION...UPDATED 18Z...
WEAK COLD FRONT/LAKE BREEZE BOUNDARY APPEARING ON ORD TERMINAL
DOPPLER RADAR OVER THE PAST HOUR... ITS PROGRESSION/PENETRATION
INLAND HAS BEEN THE GREATEST OVER LAKE COUNTY IL... WITH BOUNDARY
STILL ONLY A COUPLE OF MILES INLAND ACROSS COOK AND LAKE INDIANA
COUNTIES. SEEING A FEW ISOLATED CELLS GO UP ALONG THE BOUNDARY AND
EXPECT THIS TREND TO CONTINUE INTO THE AFTERNOON. WITH IT THE
OVERALL PRESSURE GRADIENT REMAINS WEAK AND HENCE EXPECT WINDS TO
GENERALLY REMAIN NEAR TO BELOW 10 KT WITH THE EXCEPTION OF A
HIGHER GUST POSSIBLE FROM A THUNDERSTORM.
DO EXPECT COVERAGE OF SHRA/TSRA TO INCREASE SOMEWHAT DURING THE
EARLY TO MID AFTERNOON WITH WEAK LOW LEVEL CONVERGENCE ALONG THE
BOUNDARY. AIR MASS OVERALL ONLY MODESTLY UNSTABLE HOWEVER AND
UPPER LEVEL SUPPORT SUGGESTS BETTER COVERAGE OF RAIN/STORMS WILL
COME WITH A SECOND ROUND OF SHOWERS AND THUNDERSTORMS LATER THIS
EVENING INTO THE OVERNIGHT. WILL CONTINUE TO MONITOR THESE TRENDS
AND ADJUST CHALLENGING FORECAST ACCORDINGLY.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW TO MEDIUM IN TIMING OF INDIVIDUAL SHRA/TSRA AT TERMINAL
LOCATIONS THROUGH THE AFTERNOON.
* MEDIUM IN WIND SHIFT/SPEED DETAILS WITH LAKE BREEZE
BOUNDARY/WEAK COLD FRONT THIS AFTERNOON.
* LOW TO MEDIUM IN TIMING AND COVERAGE OF SECOND ROUND OF
SHRA/TSRA LATER THIS EVENING AND OVERNIGHT.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
RATZER
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENERALLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.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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Area Forecast Discussion
National Weather Service Lincoln IL
1239 PM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 1040 AM CDT Mon Aug 4 2014
Will update the forecast to remove the morning fog over eastern IL,
otherwise just a few minor adjustments to sky cover and dewpoints today.
Weak 1021 mb high pressure over the Ohio river valley and ridging west
into the Ozarks of southern MO/northern AR will keep much of
eastern and southeast IL dry today. A short wave over central IA
to track se into NW and west central IL during the afternoon while
a frontal boundary over southern WI and near the MN/IA border
drops slowly southward into northern IL this evening. This will
develop isolated to scattered showers and thunderstorms during the
afternoon over areas mainly from I-55 nw with best chances nw of
the IL river. SPC has a 5% risk of damaging wind gusts and large
hail nw of I-55 late this afternoon and evening until sunset.
Highs in the mid 80s this afternoon looks on track. Somewhat muggy
dewpoints in the mid to upper 60s this morning to drop into the
upper 50s and lower 60s in southeast IL by mid afternoon and into
the low to mid 60s over the IL river valley. South winds less than
10 mph to prevail through the day.
07
&&
.AVIATION...
ISSUED 1240 PM CDT Mon Aug 4 2014
Isolated to scattered showers and thunderstorms will be possible
over central IL late this afternoon into mid evening especially
northern TAF sites of PIA and BMI. This due to a short wave over
IA moving se across central and northern IL into this evening with
and moving into upper level trof over OH/TN river valleys by Tue
morning. In addition, a frontal boundary drapped over southern WI
into northern IA will drop southward into northern IL later this
afternoon and to near PIA and BMI by Tue morning. Heating of more
unstable airmass over central IL to develop some convection later
this afternoon and into mid evening with best chances from I-74
north. Isolated convection to develop again Tue afternoon over
central IL after 18Z/1 pm. Winds stay less than 10 kts next 24
hours again. SSW winds of 5-9 kts this afternoon to diminish light
SSE after sunset. Light fog or haze possible between 06Z-14Z and
carried vsbys of 6 miles.
07
&&
.PREV DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1124 AM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* WIND SHIFT FROM WEST TO EAST-NORTHEAST THIS AFTERNOON WITH
COMBINATION OF COLD FRONT/LAKE BREEZE.
* SCATTERED SLOW MOVING SHRA/TSRA DEVELOPING EARLY TO MID AFTERNOON
AND CONTINUING INTO THIS EVENING/TONIGHT.
ED F
//DISCUSSION...UPDATED 12Z...
WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...THOUGH WAS HARD TO DISCERN IN SURFACE OBS WITH GENERALLY
WEAK PRESSURE GRADIENT AND LIGHT/VARIABLE WIND FIELD. VARIOUS
MODELS VARY SIGNIFICANTLY IN FINE SCALE DETAILS OF WIND FIELD
BEYOND THIS MORNING...BUT GENERAL EXPECTATION IS THAT FRONT WILL
CONTINUE TO DRIFT SLOWLY SOUTH ALONG THE LAKE AND COMBINE WITH
AFTERNOON LAKE BREEZE TO BRING A SHIFT TO NORTHEAST WINDS BY
EARLY/MID AFTERNOON. GRADIENT CONTINUES TO REMAIN WEAK WITH SPEEDS
GENERALLY LESS THAN 10 KT EXPECTED...THOUGH COULD BE AROUND 10 KT
WITH INITIAL FRONT/LAKE BREEZE PASSAGE. EAST-NORTHEAST WINDS THEN
CONTINUE THROUGH REMAINDER OF TAF PERIOD.
AS FOR SHRA/TSRA...ISOLATED CELLS OVER PARTS OF WI AND SOUTHERN
LAKE MICHIGAN EARLY THIS AM IN REGION OF WEAK ELEVATED ASCENT.
COVERAGE EXPECTED TO INCREASE EARLY THIS AFTERNOON ALONG FRONTAL
ZONE AS CONVERGENCE IN LOW LEVEL WIND FIELD INITIATES CONVECTION
IN WEAKLY UNSTABLE AIR MASS. GREATEST COVERAGE ANTICIPATED ACROSS
SOUTHERN WI/EASTERN IA AND NORTHWEST IL WHERE SOME LOW LEVEL
MOISTURE POOLING WITH YIELD MORE UNSTABLE CONDITIONS...THOUGH
CONVECTION ALLOWING MODEL GUIDANCE ALL TREND TOWARD SOME INCREASED
POTENTIAL ALONG THE FRONT AND COMBINED LAKE BREEZE BOUNDARY
INTO CHICAGO AREA AS WELL. SHRA/TSRA POTENTIAL LOOKS TO BE HIGHEST
LATER IN THE AFTERNOON INTO THIS EVENING. SCATTERED SHRA MAY
CONTINUE OVERNIGHT AS WELL...WITH SEVERAL MINOR UPPER LEVEL
DISTURBANCES PASSING ACROSS THE FORECAST AREA.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-LOW IN TIMING OF SHRA/TSRA DEVELOPMENT EARLY TO MID AFTERNOON.
* MEDIUM IN DETAILS OF WIND SHIFT/SPEED WITH COMBINED FRONT/LAKE
BREEZE THIS AFTERNOON.
* MEDIUM-LOW IN SPECIFIC LOCATIONS OF TSRA THIS AFTERNOON.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
RATZER
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENERALLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.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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Area Forecast Discussion
National Weather Service Lincoln IL
1043 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 1040 AM CDT Mon Aug 4 2014
Will update the forecast to remove the morning fog over eastern IL,
otherwise just a few minor adjustments to sky cover and dewpoints today.
Weak 1021 mb high pressure over the Ohio river valley and ridging west
into the Ozarks of southern MO/northern AR will keep much of
eastern and southeast IL dry today. A short wave over central IA
to track se into NW and west central IL during the afternoon while
a frontal boundary over southern WI and near the MN/IA border
drops slowly southward into northern IL this evening. This will
develop isolated to scattered showers and thunderstorms during the
afternoon over areas mainly from I-55 nw with best chances nw of
the IL river. SPC has a 5% risk of damaging wind gusts and large
hail nw of I-55 late this afternoon and evening until sunset.
Highs in the mid 80s this afternoon looks on track. Somewhat muggy
dewpoints in the mid to upper 60s this morning to drop into the
upper 50s and lower 60s in southeast IL by mid afternoon and into
the low to mid 60s over the IL river valley. South winds less than
10 mph to prevail through the day.
07
&&
.AVIATION...
ISSUED 605 AM CDT Mon Aug 4 2014
Other than the threat for MVFR or local IFR vsbys in ground fog
over the next 60 to 90 minutes early this morning, VFR conditions
are expected this period. The main forecast challenge for later
today will be with the potential for TSRA, especially at KPIA
and KBMI as a weak cold front slips south into the lower Great
Lakes. Satellite data and surface observations indicate a band
of mid level clouds were tracking slowly east into west central
Illinois this morning. Bases of these clouds ranged from 5000 to
7000 feet with the overall movement mainly northeast. Forecast
soundings not showing much in the way of cumulus development excpt
across the far northern areas after 18z, but even there, it appears
to be mainly scattered at around 5000 feet. Will continue to include
a VCTS at PIA after 19z as this location will be closest to the
better instability. Not very confident after 00z with respect to
any of the convection that develops across the northwest to continue
across our area so will continue to hold off mentioning at any one
TAF site this evening. Surface winds will once again be a non-factor
with a southerly wind expected today at less than 10 kts, dropping
off to 5 kts or less aftr 00z.
Smith
&&
.PREV DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
352 PM CDT Mon Aug 4 2014
...updated short term...
.SYNOPSIS...
ISSUED AT 349 PM CDT MON AUG 4 2014
Cirrus was slowly overspreading the western sections of Kansas from
the mean height ridge moving eastward from the Rockies into the High
Plains. A weak surface pressure/850 mb height gradient enveloped the
Central Plains. Relative low pressure over the eastern Colorado
resulted in a northward oriented pressure gradient gradient across
western Kansas resulting in generally south winds at most locations
with little downslope. Temperatures warmed to around 90 degrees
across in most locations as dew points mixed down to the upper 40s
from Scott City to Hugoton. Hays, which is closer to the warmer air
at 850 mb warmed into the upper 90s.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 349 PM CDT MON AUG 4 2014
The temperature trend and dew points to a lesser degree seemed to
have followed the consensus of the short term models blend fairly
well this afternoon. This trend will continue to be followed into
the rest of the forecast including Tuesday morning and into
Tuesday. The cirrus overhead may have a small impact on overnight
lows as the recent updates have bumped lows into the mid and upper
60s in most locations. The HRRR model continues to show isolated to
widely scattered convection across south central Kansas late this
afternoon likely based on reaching convective temperatures. Current
trends suggest this is overdone as was the case Sunday afternoon,
and PoPs will not be added at this time.
No major shift in airmass is taking place tonight and the same
general pattern of surface winds and diurnal warming is expected
heading into Tuesday afternoon. A breakdown in the ridge by a mid
level shortwave will create scattered convection across northeast
and east central Colorado by late in the afternoon. Low PoPs will be
included for about the western half of the area starting at about
about 23 UTC, following previous forecasts.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 341 PM CDT MON AUG 4 2014
The upper level ridge will flatten out and be shunted southward
during the next couple of days as a series of upper level
shortwaves move up and over the ridge. These features will bring a
chance of thunderstorms to the forecast area through this weekend.
The slight chance of thunderstorms will start out across far
western Kansas Tuesday night then across central Kansas Wednesday
night. Otherwise expect partly cloudy skies. Winds will generally be
from the south to south southwest Tuesday night through Thursday
with a surface trough located across eastern Colorado and far
western Kansas. A better chance of thunderstorms will be expected
this weekend as the upper level ridge slould retrogrades towards the
southwest United States. Winds will generally be from the southeast
during this time frame as a stationary front will be located at the
surface south of the area with a dome of high pressure to the north.
Highs through the extended period will generally be in the low to
mid 90s with lows in the upper 60s and lower 70s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 126 PM CDT MON AUG 4 2014
VFR conditions are expected through this TAF period. The only caveat
might be a few widely scattered weak high based CB`s mainly to the
east of the Dodge City and Hays terminals late in the afternoon
which would end with loss of surface heating as the Hi-Res Rapid
Refresh. Surface winds remain light through the period as well
before increasing to around 12-15 knots by around 15 UTC on Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 93 69 95 / 0 10 20 20
GCK 68 90 68 94 / 0 20 20 20
EHA 66 91 67 95 / 0 20 20 10
LBL 66 92 69 96 / 0 10 20 10
HYS 68 96 70 94 / 0 10 20 30
P28 68 93 71 94 / 0 10 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Hovorka_42
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1229 PM CDT Mon Aug 4 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT MON AUG 4 2014
Weak mid level trough shifting southeast across northern MO this
morning with another shortwave trough noted over SD. A few isolated
showers have developed over far eastern KS this morning with weak
isentropic ascent in the presence of a 35 kt LLJ. While the HRRR is
overdone on coverage of showers, the ARW and NMM high-res guidance
is also picking up on a few isolated showers continuing through mid
morning. Will leave a slight chance mention through this time, but
confidence is low for measurable precipitation.
Showers over SD are progged to dissipate over NE while the upper
ridge to our west shifts east into the area today and tonight. At the
surface, the trough axis shifts southward, pushing a weak boundary
near the Interstate 70 corridor by afternoon. Strength of
convergence on the boundary varies by the model with the 06Z NAM
being the outlier and most progressive with mid 60 dewpoints creating
a more unstable and weakly capped boundary layer during peak
heating. All other short and mid term guidance points to weak
forcing on the boundary, subsidence aloft while mid-level ascent is
displaced further east. With some near sfc convergence along the
boundary, cannot completely rule out an isolated storm and will hold
onto slight chances for thunderstorms this afternoon through early
evening. Any storm that is able to develop may produce gusty winds.
850 mb thermal ridge axis spreads east during the day just above
20C, rising highs into the lower and middle 90s. Another upper
trough passes over Iowa and MO tonight, increasing scattered mid
level clouds and lows in the low 70s.
.LONG TERM...(Tuesday through Sunday)
Issued at 321 AM CDT MON AUG 4 2014
The long term period is rather unsettled with a consistent train
of weak disturbances (and a few more organized ones) crossing the
central plains through the coming week.
Tuesday looks to have the best chance of the coming week to be dry
as the local area should be in between weak disturbances and the
low levels should be somewhat dried out...limiting instability.
That said, it should also be the hottest day of the next week with
slight ridging overhead and likelihood of quite a bit of sunshine.
Expect highs from the lower 90s far northeast to the upper 90s in
north central KS.
By late Tuesday night, the short wave currently in the Las Vegas
area should move out across Nebraska along a stationary front just
north of the KS/NE border, and seems likely to support a broad
area of thunderstorm activity/MCS. The bulk of the storms Tuesday
night are likely to stay north of the forecast area but could get
a few storms to develop/move in after midnight. By Wednesday, the
front will move south into the area as a northern stream trough
dives into the Great Lakes and brings a cooler airmass south. The
frontal progression along with additional short waves moving
across the Plains from the southwest will provide a favorable
setup for one or more convective complexes to impact the forecast
area Wednesday afternoon through Thursday morning with additional
development on Thursday afternoon. Moderate instability and weak
shear through this period should mitigate the severe potential,
but locally heavy rainfall/flooding may become an issue depending
how these convective complexes evolve. Dry antecedent soil
conditions will mitigate the flood threat a bit, but still seems
possible if a backbuilding situation sets up.
Thunderstorm chances continue through the remainder of the
forecast period but confidence in the details of timing and
magnitude is not high. Expect days with moderate to strong
instability but wind shear looks to remain marginally adequate for
organized storms. Thunderstorm chances will also depend at least
somewhat on how far the front moves south of the area as a
drier airmass may try to push in from the northeast if the front
moves far enough south.
Temperatures will cool a bit after the Wednesday frontal passage
and highs should be a bit below normal in the mid to upper 80s for
the Thursday through Sunday time frame with lows in the middle to
upper 60s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1225 PM CDT MON AUG 4 2014
VFR conditions expected through the taf period. Winds overnight
will gradually veer to the east, and eventually the south by
tomorrow morning, but remain light though most of that time frame.
Isolated showers will dissipate after sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Barjenbruch
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
303 PM CDT Mon Aug 4 2014
...An unsettled and wet weather pattern for the end of the
week...
.SHORT TERM...(This Evening through Tuesday)
Issued at 240 PM CDT MON AUG 4 2014
A nice cumulus field is developing with daytime heating and
instability this afternoon especially over southern Missouri.
There is a very subtle upper level shortwave moving through the
area this afternoon. The latest HRRR is indicating isolated to
scattered convection to develop by 22z near I-44 and move
southward into the early evening hours. Will still carry 20 to 30
percent pops for this general area into the evening hours.
Another upper level wave will move across the northern part of the
state by early tomorrow morning with some possible convection
making its way into central Missouri and the eastern Ozarks
tomorrow morning. Will carry a slight mention of pops for tomorrow
morning for this general area and a slightly better chance for
convection east of Highway 65 Tuesday afternoon.
.LONG TERM...(Tuesday Night through Monday)
Issued at 240 PM CDT MON AUG 4 2014
The upper level ridge of high pressure which has been in control
of our weather pattern will break down somewhat over us and allow
multiple shortwaves to ride down a west-northwest flow. A front
will meander into the region by Thursday and pretty much stall out
over the Missouri Ozarks or nearby through weekend.
There will be several rounds of convection and possible MCS
activity riding along that front through the area. The first chance
for widespread convection will be late Wednesday night into
Thursday morning with another rounds developing Thursday night
into Friday morning and possibly another round Friday night into
Saturday morning. Timing and exact placement is difficult to
pinpoint down at this time. The ECMWF is most bullish than the
GFS and GEM but all have the same idea.
Will mention a slight risk for heavy rainfall and some flash
flooding threat for the end of the week with widespread one to
three inches likely with isolated higher amounts over the eastern
Ozarks and central Missouri areas.
Temperatures by the end of the week will be dependent on where the
stalled front is positioned and on going convection and cloud
cover...but generally cooler temperatures in the lower 80s for the
eastern half of the CWA and upper 80s for southeast Kansas and far
southwest Missouri for the Thursday through Saturday time frame.
The front finally lifts back to the north or washes out by early
next week with temperatures moderating back to near normal and
slight pops lingering in the afternoon.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Pilots flying in and out of the southwest Missouri airports can
expect VFR conditions over the next 24 hours. However, we
recommend keeping an eye on radar trends this afternoon and
evening, as a few isolated thunderstorms could develop in some
places. Given the isolated nature of these storms, we did not
include a mention into the TAFS yet.
High pressure is directly over the region this afternoon, causing
winds to be light and variable. Surface winds will eventually
become more south or southeasterly tonight.
Safe Travels.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Cramer
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1216 PM CDT Mon Aug 4 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 307 AM CDT Mon Aug 4 2014
Precip chances continue to be the primary forecast challenge in the
short range. Scattered thunderstorms are once again moving over
parts of northwest and west central Missouri this morning. RAP
shows an area of weak moisture convergence at 850mb which closely
conforms to the activity on radar at this time; so will go under the
assumption that this is what`s forcing the convection. The moisture
convergence continues basically over the same region through 12Z
before slowly weakening according to the RAP. Most operational
models tend to agree with the RAP and keep the vast majority of the
CWFA dry today. However, the NAM has other ideas and spreads this
moisture convergence eastward across much of Missouri into west
central Illinois by 00Z. This looks like it may be in response to
the subtle shortwave currently diving southeast along the South
Dakota/Nebraska/Iowa borders. NCEP and NSSL 4km WRFs both break out
convection over the area, which more closely supports the NAM
solution today. Further, the NAM and NCEP WRF handled yesterday`s
precip over central Missouri much better than the other models, so I
have more confidence in them than the rest of the suite. Have
therefore bumped up PoPs to mid-chance across much of central and
northeast Missouri into west central Illinois today, fading to low
chance/slight chance further to the southeast. Persistence highs
from 85-90 still look good for today.
Carney
.LONG TERM: (Tonight through Sunday)
Issued at 345 AM CDT Mon Aug 4 2014
The latest model data now advertises NW upper level flow persisting
over our region thru the next seven days--a bit of a departure from
what they were showing 2-3 days ago. The only real difference and
how to split the upcoming week is from amplified flow thru Tuesday,
from less amplified flow Wednesday into Saturday, before it becomes
amplified again with re-establishment of the western CONUS upper
ridge. Although with a couple of days of fairly steady model
output, confidence is increasing on the chances for some badly
needed rain for mid and late week, with additional chances today and
tomorrow simply as a bonus.
Decently moist air (1.5" or greater PWs) will already be in place
for most areas by early this evening and is anticipated to remain so
thru at least the end of the week with a period of 2" or greater PWs
late Wednesday into early Friday. It will be hard to find dry
periods in this forecast with a moisture regime such as this unless
we can also find an atmosphere nearly devoid of lift or convective
instability.
Leftover and what should be weakening convection is expected to once
again spillover for a short time early this evening before
retreating to northern MO and central IL where a frontal boundary
will be. But with anticipated propagation of TSRA from source
region to the south once again, like it is doing now, should see
chances for rain expand southward for most of the area late tonight,
all the while with the frontal boundary slowly pushing south.
Chances for TSRA on Tuesday will persist for areas near I-70 and
south where the weak frontal boundary will be before this is
expected to weaken/dissipate Tuesday night in favor of a stronger
wave of low pressure over the Plains and a likely MCS that will be
mainly to our north initially. Max temps on Tuesday should be in
the lo 90s for areas from I-70 and south with a hit of a few degrees
taken for areas further north with anticipated mild impact from the
front.
Models generally favor the lion`s share of the Tuesday night MCS to
miss us on Wednesday, with the best chances in central IL, but one
effect this should have is to once again shove the front further
south into our region Wednesday afternoon. Exactly when this
happens could have a BIG effect on our max temps Wednesday with hi
bust potential, but currently anticipating a delayed southward push
with decent warmup for the I-70 corridor and south--with readings
breaking 90 degrees. When the front does drop down, it should also
ignite TSRA later on Wednesday afternoon with some strong storms
possible.
The overall synoptic setup looks favorable for a more widespread
rain Wednesday night thru early Friday, with a surface front just to
the south of most of the area and a reasonably strong upper
shortwave TROF passing thru in a very moist environment. Expanded
on use of likely PoPs from previous shift with another round of
below normal temps looking much more likely as well.
Heading into next weekend, low confidence forecast returns again
with PoPs near or just a hair below climo with a not favorable
synoptic setup, but with persistent moist atmosphere, probably a
signal we are not seeing that will eventually result in a low PoP
forecast. Temps will make an attempt at returning towards
normal--which by now are now slowly declining as we have passed the
warmest climatological time of the year.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1205 PM CDT Mon Aug 4 2014
High pressure remains over the region with a weak cold front
expected to sag south into northern MO Tuesday morning. This may
trigger some showers/thundertorms with the main activity being
further north over the upper Midwest. UIN looks to have the best
chance ovenigh with a prob30 possible after 06z. Otherwise nothing
strong to pinpoint so VCTS looks to be the main forecast tool.
Specifics for KSTL:
Can`t rule out a thunderstorms popping up this afternoon, but with
the 850MB high pretty much parked over the area, it does not look
favorable. Weak front sags into northern MO tonight. Will it make
it to STL? Always difficult to tell this time of year. If it does,
it ceratinly could increase chances of showers/thunderstorms, but
enough uncertainty remains to go no higher thatn VCTS. JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
320 PM MDT MON AUG 4 2014
.SHORT TERM...VALID FOR TUE AND WED...
SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED FROM TONIGHT
THROUGH TUE NIGHT WITH LOCALLY HEAVY RAINFALL A POSSIBILITY THANKS
TO ANOMALOUS ATMOSPHERIC MOISTURE CONTENT IN MONSOONAL FLOW. GIVEN
THE CONVECTIVE NATURE OF THIS SCENARIO...NOT EVERYONE IS LIKELY TO
RECEIVE HEAVY RAINFALL THOUGH.
AS OF MID AFTERNOON...SHOWERS AND STORMS ARE FILLING IN OVER SOUTH
CENTRAL MT AND NORTH CENTRAL WY AS FORCING WITH A LEAD AND DEFINED
SHORTWAVE IMPULSE HEADS NORTHWARD INTO THE REGION. MOST ALL OF THE
12 UTC GUIDANCE CONTINUED SHOWING MODERATE QG-FORCING SPREADING TO
THE NORTHEAST THROUGH TONIGHT...SO WE BELIEVE THE SHOWER AND STORM
ACTIVITY WILL FOLLOW SUIT. RECENT HRRR RUNS ARE ON BOARD WITH THIS
IDEA AND WE FOLLOWED ITS SOLUTION HEADING THROUGH THE EVENING WITH
LIKELY POPS SPREADING NORTHEASTWARD. THE SYNOPTIC-SCALE QG-FORCING
WITH THIS SHORTWAVE IMPULSE IS MAINLY RELEGATED TO SOUTHEASTERN MT
ON TUE...AND IT WILL BE DECREASING WITH TIME. HOWEVER...CONVECTION
SHOULD NONETHELESS BE DIURNALLY ENHANCED ACROSS THE ENTIRE AREA BY
AFTERNOON IN A MOIST AND WEAKLY UNSTABLE AIR MASS. THE 15 UTC SREF
SUPPORTS 300-800 J/KG OF SBCAPE...WEAK MID-LEVEL LAPSE RATES...AND
UNDER 25 KT OF 0-6-KM SHEAR...SUGGESTIVE OF SLOW-MOVING STORMS AND
LOCALLY HEAVY RAINFALL. MOST 12 UTC GUIDANCE...INCLUDING THE NCEP-
RUN CONVECTION-ALLOWING MODELS...SUGGEST THE MOST INTENSE ACTIVITY
OVER THE NEXT 48 HOURS MAY BE LATE TUE AFTERNOON INTO TUE NIGHT IN
SOUTHEASTERN MT. THAT IS REASONABLE AS THAT AREA MAY HAVE A BETTER
OPPORTUNITY TO DESTABILIZE WITH RELATIVELY GREATER CAPE SUPPORTIVE
OF MORE CONCENTRATED UPDRAFTS /DEPENDING ON THICKNESS OF CLOUDS/.
AS FOR THE HEAVY RAINFALL POTENTIAL...SPC SSEO OUTPUT REVEALS MEAN
RAINFALL TOTALS TONIGHT OF 0.20 TO 0.40 INCHES...AND THE 09 AND 15
UTC SREF RUNS SUGGESTED LESS THAN A 30 PERCENT PROBABILITY OF 0.50
INCHES OR MORE OF RAIN. DEEPER CONVECTION WILL YIELD LOCAL AMOUNTS
HIGHER THAN THAT...BUT THE STATISTICAL EVIDENCE POINTS AWAY FROM A
WIDESPREAD HEAVY RAIN EVENT. THE SREF DOES SUGGEST A HIGHER CHANCE
OF GREATER THAN A HALF INCH OF RAIN OVER SOUTHEASTERN IN THE BAKER
AND EKALAKA AREAS LATE TUE AFTERNOON INTO TUE NIGHT...MATCHING THE
SIGNALS SEEN IN THE 12 UTC DETERMINISTIC MODEL OUTPUT FOR A THREAT
OF MORE BONAFIDE HEAVY RAIN IN THAT PART OF SOUTHEASTERN MT.
BY WED...WEAK INSTABILITY WILL STILL EXIST AND IS SUFFICIENT FOR A
CHANCE OF SHOWERS AND STORMS...BUT GENERALLY-SPEAKING WE FEEL THAT
THE PROBABILITY WILL BE LOWER THAN TUE WITHOUT ANY DEFINED FORCING
ALOFT. HIGHS TUE WILL PROBABLY NOT REACH 80 F GIVEN THE CLOUDS AND
MOISTURE /AND WE DID LOWER HIGHS A BIT TOWARD THE 00 UTC CONSENSUS
OF RAW...2 M MODEL TEMPERATURE OUTPUT/...BUT THEY SHOULD WARM UP A
BIT AGAIN WED IF CLOUD COVER IS SOMEWHAT LESS THAT DAY. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
MODELS WERE IN PRETTY GOOD AGREEMENT THROUGH THE FORECAST PERIOD.
ENERGY GRADUALLY WORKS ACROSS THE FORECAST AREA THURSDAY AND
FRIDAY FOR WEAK LIFT AND SOME INSTABILITY. LINGERING MONSOON
MOISTURE WILL ALSO BE INVOLVED HERE SO NEED TO KEEP SOME MENTION
OF POPS. QUESTION FOR ME IS THE DRY AIR PRESENT ON WATER VAPOR
IMAGERY WORKING INTO SOUTHERN ARIZONA. HOW WILL THIS WORK TO DRY
OUT THE MONSOON PLUME WORKING INTO THE NORTHERN ROCKIES? THIS
COULD LIMIT THE CHANCE OF CONVECTION DESPITE THE TROUGH MOVING
THROUGH. ALL IN ALL...LOOKS LIKE THE DEEPEST MOISTURE WILL BE EAST
OF BILLINGS. DOES NOT LOOK OVERLY HOT THROUGH SATURDAY WITH
HEIGHTS STAYING BELOW 588DM. HEIGHTS BUILD LATE IN THE WEEKEND
INTO EARLY NEXT WEEK FOR WARMER WEATHER. TWH
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHEAST TONIGHT. SOME OF
THE STORMS MAY CONTAIN HEAVY RAINFALL WITH LOCAL IFR CONDITIONS.
THE MOUNTAINS WILL BE MOSTLY OBSCURED. EXPECT ADDITIONAL SHOWERS
AND STORMS ON TUESDAY WITH MONSOONAL MOISTURE REMAINING IN PLACE
ACROSS SOUTHERN MT AND NORTH CENTRAL WY. SCHULTZ/TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 063/079 059/084 060/087 061/088 061/090 062/090 062/090
75/T 42/T 22/T 22/T 21/U 11/B 11/B
LVM 054/078 052/083 053/084 053/086 053/087 054/090 053/089
75/T 43/T 33/T 32/T 22/T 22/T 22/T
HDN 064/081 059/086 058/088 059/089 059/091 060/091 061/092
76/T 52/T 22/T 22/T 21/U 11/B 11/B
MLS 067/080 062/082 060/087 063/090 063/091 063/092 064/092
67/T 62/T 22/T 22/T 21/U 11/B 11/U
4BQ 064/080 060/082 057/086 060/087 060/089 061/090 063/091
67/T 64/T 22/T 22/T 22/T 21/B 11/U
BHK 063/074 058/077 055/083 058/087 057/088 059/089 063/089
67/T 74/T 22/T 22/T 22/T 12/T 21/U
SHR 060/077 057/082 055/086 056/086 055/089 056/089 058/087
76/T 63/T 32/T 23/T 32/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1259 PM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1259 PM CDT MON AUG 4 2014
UPDATED THE FORECAST TO LOWER FORECAST HIGHS ACROSS SOUTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. A COMPLEX OF SHOWERS WITH EMBEDDED
THUNDERSTORMS IS SLOWLY MOVING SOUTHEAST...AND SHOULD BE OUT OF
THE AREA BY LATE AFTERNOON.
OTHERWISE...THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE
UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 944 AM CDT MON AUG 4 2014
ONGOING CONVECTION SOUTHWEST OF THE MISSOURI RIVER IS ASSOCIATED
WITH AN SUBTLE UPPER LEVEL SHORTWAVE MOVING ACROSS THE STATE THIS
MORNING. RADAR DETECTED A STORM THAT WAS CAPABLE OF PRODUCING
SEVERE HAIL OVER EASTERN GRANT COUNTY ABOUT AN HOUR AGO.
HOWEVER...NO SEVERE REPORTS WERE RECEIVED. THESE STORMS ARE NOW
MOVING INTO CORSON COUNTY SOUTH DAKOTA AS OF THE TIME OF THIS
WRITING.
THE LATEST HRRR MAINTAINS CONVECTION OVER MOST OF SOUTHWESTERN AND
SOUTH CENTRAL NORTH DAKOTA THROUGH THE LATE MORNING HOURS...WITH
DECREASING THUNDERSTORM CHANCES DEVELOPING FROM WEST TO EAST THIS
AFTERNOON AS SUBSIDENCE DEVELOPS ON THE BACK SIDE OF THE
SHORTWAVE. KEPT THIS TREND GOING IN THE CURRENT FORECAST AND
UPDATED TO INCREASE MORNING POPS. ALSO REMOVED MORNING FOG WORDING
FROM THE ZONES. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 701 AM CDT MON AUG 4 2014
THE 00 UTC WRF-NMM AND ARW...06 UTC NAM AND 10 UTC HRRR HAVE A
GOOD HANDLE ON THE ONGOING CONVECTION ACROSS SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA...AND WILL FOLLOW THEIR SOLUTIONS FOR POPS
THE REMAINDER OF THE DAY. OVERALL...CONVECTIVE COVERAGE WILL BE
GREATEST THIS MORNING...BECOMING ISOLATED TO SCATTERED THROUGH THE
AFTERNOON AS UPPER LEVEL FORCING BECOMES MORE NEBULOUS. GIVEN
WEAK INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON AUG 4 2014
THE MAIN FORECAST PROBLEM WILL BE THE CONVECTIVE POTENTIAL
THROUGH THE PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE EXTENDED FROM WESTERN ONTARIO TO
EASTERN NORTH DAKOTA WHILE LOW PRESSURE CONTINUED TO DEEPEN OVER
WYOMING AND COLORADO. AT UPPER LEVELS...SHORTWAVES CONTINUE TO MOVE
THROUGH THE UPPER FLOW FROM SOUTHWESTERN CANADA ACROSS THE ROCKIES
AND INTO THE FRONT RANGE AND NORTHERN PLAINS STATES. ONE RELATIVELY
STRONG SHORTWAVE ENERGY VORT MAX WAS OVER EASTERN MONTANA...LIKELY
ASSOCIATED WITH A LINE OF THUNDERSTORMS BETWEEN GLASGOW AND
BILLINGS. THIS AREA OF CONVECTION HAS HELD TOGETHER AND CONTINUES TO
MOVE SOUTHEASTWARD. ANOTHER AREA OF CONVECTION BEGAN IN WESTERN
SOUTH DAKOTA LATE SUNDAY EVENING/EARLY MONDAY MORNING. A LOW LEVEL
JET FROM WESTERN AND CENTRAL SOUTH DAKOTA...TO SOUTH CENTRAL AND
WESTERN NORTH DAKOTA...TO EASTERN MONTANA IS LIKELY ASSOCIATED WITH
THE CONVECTION IN SOUTH DAKOTA. THERE WERE A COUPLE OF SMALL CELLS
THAT DEVELOPED OVER GOLDEN VALLEY AND SLOPE COUNTIES IN THE PAST
HOUR OR TWO.
THE COMBINATION OF THE APPROACHING UPPER LEVEL VORT MAX IMPULSE IN
EASTERN MONTANA...AND THE DEVELOPING LOW LEVEL JET OVER THE WESTERN
DAKOTAS AND EASTERN MONTANA...SHOULD AID IN DEVELOPMENT OF ELEVATED
SHOWERS AND THUNDERSTORMS BEFORE SUNRISE. THE MODELS INDICATE THE
UPPER LEVEL IMPULSE SPREADING SOUTHEAST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING...AND WEAKENING THIS AFTERNOON AS IT MOVES
SOUTHEAST TOWARDS EASTERN SOUTH DAKOTA. HAVE CHANCES OF
THUNDERSTORMS EARLY THIS MORNING WITH SCATTERED COVERAGE
EXPECTED...THEN BECOMING MORE ISOLATED IN NATURE BY AFTERNOON.
TONIGHT ANOTHER MORE VIGOROUS SET OF UPPER LEVEL IMPULSES EMANATING
FROM THE CENTRAL US ROCKIES IS FORECAST TO MOVE NORTHEASTWARD
ACROSS MONTANA AND WYOMING THIS AFTERNOON...REACHING SOUTHWESTERN
NORTH DAKOTA LATER THIS EVENING AND SPREADING TOWARDS CENTRAL NORTH
DAKOTA LATE MONDAY NIGHT. THE BEST CAPE/SHEAR COMBINATION TONIGHT IS
OVER MONTANA...WITH THE SURFACE HIGH FROM WESTERN ONTARIO NUDGING
FURTHER INTO EASTERN NORTH DAKOTA. THUS NOT EXPECTING SEVERE STORMS
TO REACH WESTERN NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON AUG 4 2014
THUNDERSTORM AND RAINFALL POTENTIAL WEST AND SOUTH CENTRAL TUESDAY
AND WEDNESDAY WILL HIGHLIGHT THE EXTENDED.
A CONSENSUS OF THE 00 UTC GLOBAL AND HIGH RESOLUTION GUIDANCE
PROPAGATES THE UPPER LEVEL LOW ACROSS SOUTHWEST ALBERTA TODAY INTO
EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE TUESDAY AND INTO
WEDNESDAY...WITH SURFACE HIGH PRESSURE ACROSS NORTHEAST NORTH
DAKOTA INTO THE UPPER MISSISSIPPI VALLEY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ACROSS
EASTERN MONTANA...PROPAGATING INTO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA BY LATE AFTERNOON/EARLY EVENING. RE-DEVELOPMENT IS FORECAST
FOR THESE AREAS AGAIN WEDNESDAY ALONG THE WESTERN PERIPHERY OF THE
SURFACE HIGH. OVERALL INSTABILITY IS WEAK...WITH LITTLE CHANCE FOR
SEVERE STORMS...IN LINE WITH THE SPC DAY 2 AND 3 OUTLOOKS. LOCALLY
HEAVY RAINFALL IS A POSSIBILITY WITH PWATS NEAR 1.50 INCHES AND
SLOW STORM MOTIONS WITH WEAK LOW TO MID LEVEL FLOW.
THEREAFTER...FOR WEDNESDAY THROUGH THE WEEKEND...NEAR ZONAL FLOW IS
FORECAST...FAVORING NEAR NORMAL TEMPERATURES AND SPORADIC
THUNDERSTORM CHANCES WITH WEAK IMPULSES EMBEDDED IN THE SOUTHERN
PERIPHERY OF THE UPPER JET.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1259 PM CDT MON AUG 4 2014
VFR CONDITIONS ARE EXPECTED TO PERSIST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THROUGH THE TAF PERIOD. A COMPLEX OF SHOWERS WILL
CONTINUE TO PUSH SOUTH OF KBIS THIS AFTERNOON. OTHERWISE...THE
NEXT CHANCE OF CONVECTION IS EXPECTED TO DEVELOP OVER SOUTHWESTERN
NORTH DAKOTA (KDIK) AFTER SUNRISE TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...JV
LONG TERM...AYD
AVIATION...TM
AREA FORECAST DISCUSSION
NWS MEDFORD OR
259 PM PDT MON AUG 4 2014
.DISCUSSION...WATER VAPOR IMAGERY IS SHOWING A LARGE PLUME OF
MONSOONAL MOISTURE LIFTING NORTHWARD THROUGH NORTHERN CALIFORNIA
AND INTO OREGON THIS AFTERNOON. THIN CIRRUS AND WILDFIRE SMOKE HAS
BEEN INHIBITING SURFACE HEATING A BIT EARLY THIS AFTERNOON, BUT
RADAR IMAGERY IS NOW SHOWING SOME SHOWER/THUNDERSTORM DEVELOPMENT
IN LAKE AND MODOC COUNTIES. THIS ACTIVITY WILL CONTINUE TO ENHANCE
THIS AFTERNOON AND MOVE TO THE WEST SOUTHWEST THROUGH THIS
EVENING. INSTABILITY WILL ALSO CONTINUE TO INCREASE FROM SISKIYOU
COUNTY NORTHWARD UP ALONG THE CASCADES AND EXPECT THUNDERSTORMS TO
DEVELOP THERE TOO AS THE CAP ERODES. THERE IS STILL A SIGNIFICANT
THREAT FOR A LOT OF LIGHTNING WITH THESE STORMS AND AS A RESULT,
WE ARE MAINTAINING THE RED FLAG WARNING THROUGH THE FIRST PART OF
TONIGHT (2AM PDT). WITH THE UPPER LOW NEAR TAHOE, THE FLOW ALOFT IS
FAIRLY LIGHT OUT OF THE NORTHEAST, SO STORM MOTIONS WILL BE ON THE
SLOW SIDE. PRECIPITABLE WATER VALUES OVER A BROAD AREA ARE
1.00-1.25 INCHES, SO STORMS THAT DO DEVELOP WILL PRODUCE RAINFALL.
DUE TO SLOW STORM MOTIONS, SOME OF THE STRONGER STORMS WILL HAVE
THE CAPABILITY OF PRODUCING VERY HEAVY RAINFALL. THIS MAY PRESENT
A FLASH FLOOD THREAT...ESPECIALLY TO AREAS THAT HAVE PREVIOUSLY
BURNED. WITH THE SOUTHWESTWARD MOVEMENT, SOME STORMS THAT FORM
OVER THE CASCADES AND THE EAST SIDE THIS AFTERNOON MAY DRIFT OVER
THE ROGUE VALLEY THIS EVENING. LATEST HRRR GUIDANCE IS INDICATING
THAT MANY OF THE STORMS THAT GET GOING THIS AFTERNOON AND EVENING
WILL MORPH INTO AN AREA OF SHOWERS WITH EMBEDDED THUNDER LATE
TONIGHT INTO TUESDAY MORNING AS IT CONTINUES TO SAG SLOWLY
SOUTHWESTWARD. THIS SEEMS REASONABLE AS WE LOSE THE DAYTIME
INSTABILITY AND THE AXIS OF DEFORMATION STARTS TO SHIFT SOUTHWARD.
WE EXPECT THE BEST THUNDERSTORM PROBABILITIES TO SHIFT
SOUTHEASTWARD TUESDAY AFTERNOON AND EVENING AS THE UPPER LOW FILLS
AND THE DEFORMATION AXIS CONTINUES SOUTHEASTWARD...BUT STILL
EXPECT SOME DEVELOPMENT IN NORTHERN CALIFORNIA AND PORTIONS OF
SOUTHERN KLAMATH AND LAKE COUNTIES. WE HAVE DECIDED TO WAIT TO SEE
HOW MUCH LIGHTNING AND RAINFALL WE GET WITH TODAY`S STORMS AND
HAVE PUSHED BACK THE START TIME OF TUESDAY`S FIRE WEATHER WATCH TO
18Z. MUCH WILL DEPEND ON HOW MUCH RESIDUAL CLOUD COVER REMAINS IN
THE MORNING AND IF WE CAN GET SOME SUN TO DESTABILIZE THE
ATMOSPHERE FOR THE AFTERNOON. WEST TO NORTHWEST FLOW ALOFT WILL
BEGIN TO MOVE INTO NORTHWESTERN SECTIONS OF THE CWA TUESDAY, SO
WE`RE NOT EXPECTING ANY DEVELOPMENT WEST OF THE CASCADES.
BY WEDNESDAY, THERE IS STILL A SLIGHT CHANCE OF THUNDERSTORMS
ACROSS SOUTH AND EAST SECTIONS OF THE CWA, BUT THE REST OF THE
AREA WILL BE DRY AS NORTHWESTERLY FLOW ALOFT TAKES OVER. WE SHOULD
CATCH A BREAK THURSDAY WITH ACTIVITY STAYING MOSTLY SOUTH WITH
NEAREST ISOLATED ACTIVITY POPPING UP ALONG THE SIERRAS/LASSEN
AREA SOUTH OF THE CWA.
FRIDAY THROUGH THE WEEKEND...AN UPPER TROUGH WILL DEVELOP NEAR THE
NORTHWEST CALIFORNIA COAST AND THIS MAY DEVELOP INTO ANOTHER UPPER
LEVEL LOW. THIS WILL INCREASE THUNDERSTORM CHANCES AGAIN OVER THE
MOUNTAINS AND FROM THE CASCADES EASTWARD. SPILDE
&&
.AVIATION...FOR THE 04/18Z TAFS...SMOKE WILL CONTINUE TO AFFECT
VISIBILITY OVER PORTIONS OF SOUTHWEST OREGON AND NORTHERN
CALIFORNIA TODAY. HOWEVER, THE TERMINALS ARE NOT HAVING ANY
RESTRICTIONS. IFR CIGS IN STRATUS WILL IMPACT THE COAST (INCLUDING
KOTH) ALTHOUGH THE STRATUS WILL DISSIPATE TO NEAR THE BEACHES LATE
THIS AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO DEVELOP INLAND THIS AFTERNOON MAINLY NEAR AND EAST OF THE
CASCADES AND ACROSS NORTHERN CALIFORNIA. CIGS AND VIS WILL BE VFR
OUTSIDE STORMS, BUT STORMS MAY BRING HEAVY RAIN WITH POSSIBLE MVFR
OR EVEN IFR CIGS AND VIS THROUGH THE NIGHT.
&&
.MARINE...UPDATED 300 PM PDT 4 AUG 2014...
A THERMAL TROUGH PATTERN ALONG THE COAST WITH HIGH PRESSURE OFFSHORE
WILL MAINTAIN GUSTY NORTH WINDS AND ELEVATED SEAS THROUGH THE
WEEK...MAINLY ACROSS THE WATERS SOUTH OF CAPE BLANCO. VERY STEEP
SEAS WILL BE CONFINED TO AREAS BEYOND 10NM FROM SHORE AND SOUTH OF
GOLD BEACH. THE THERMAL TROUGH PATTERN WILL STRENGTHEN WEDNESDAY INTO
FRIDAY...SO INCREASING WINDS AND SEAS ARE EXPECTED. JBL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 2 AM PDT TUESDAY FOR ORZ617-620>625.
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR ORZ621-623>625.
CA...RED FLAG WARNING UNTIL 2 AM PDT TUESDAY FOR CAZ280>282-284-285.
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR CAZ280>282-284-285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT
THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THURSDAY
FOR PZZ356-376.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376.
$$
MAS/CC/JBL
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
122 PM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1053 AM CDT MON AUG 4 2014
HAVE UPDATED THE FORECAST TO BROADEN THE CHANCE OF THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING HOURS. COMPLEX OF STORMS ACROSS
NORTH CENTRAL SOUTH DAKOTA DRIFTING SOUTH SOUTH EAST. WHILE THE
BETTER JET DYNAMICS ARE ACROSS THE EASTERN HALF OF THE FORECAST
AREA...STORMS CONTINUE TO BUILD INTO AN UNSTABLE ENVIRONMENT. WITH
ELEVATED CAPE OF 1-2K...UPDATED THE HWO TO ADD MENTION OF HAIL.
SHEAR PROFILES ARE FAR FROM IDEAL...BUT STRONGEST STORMS THIS
AFTERNOON MAY APPROACH THE LOW END OF SEVERE WITH HAIL BEING THE
MAIN THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 119 PM CDT MON AUG 4 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. ISOLATED TO
SCATTERED SHOWERS AND STORMS ARE POSSIBLE THROUGH THIS AFTERNOON
INTO EARLY THIS EVENING. GIVEN SPORADIC COVERAGE AND OVERALL LACK
OF RESTRICTION TO VISIBILTY...DID NOT ADD MENTION INTO THE
FORECAST. MORE WIDESPREAD ACTIVITY SHOULD DEVELOP AFTER MIDNIGHT
WITH WARM AIR ADVIECTION. TIMING AT TAF SITES IS NOT CERTAIN...SO
FOR NOW...HAVE LEFT MENTION OUT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JH
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1235 PM CDT MON AUG 4 2014
.AVIATION...
/|18Z TAFS/
VFR expected for the next 24 hours. Scattered CUmulus should
develop in the next few hours...with more dense cloud cover mainly
south of a SJT to BWD line. A few showers will be possible near
the JCT/SOA areas by late afternoon...but not enough confidence or
coverage to warrant mention of thunder in the TAFS. Light winds
and mostly clear skies expected overnight.
08
&&
.PREV DISCUSSION... /ISSUED 601 AM CDT MON AUG 4 2014/
AVIATION...
/12Z TAFS/
VFR conditions are expected to prevail today and tonight at
the TAF sites. Expect a cumulus field to develop across our
eastern and central counties late this morning and afternoon.
There is a slight chance of showers and thunderstorms across
the area generally southeast of a Sonora to Lake Brownwood
line this afternoon and evening. With the low anticipated
coverage however, not including a mention in the TAFs at
this time. Any lingering convection will dissipate by sunset,
with clear to partly cloudy skies expected overnight. Winds
will be from the east or east-northeast at 5-10 KT today, and
from the east-southeast at decreased speeds tonight.
PREV DISCUSSION... /ISSUED 333 AM CDT MON AUG 4 2014/
SHORT TERM...
(Today and Tonight)
A weak lower to mid-level disturbance along the Texas coast will
move to the southwest today, while the upper ridge remains in
place from northern Mexico and the Texas Big Bend region north
into the central Rockies.
As the disturbance moves southwest today, associated lower to
mid-level moisture will move west into our area. The combination
of surface heating, moisture increase and marginally sufficient
destabilization could allow isolated or widely scattered showers
and thunderstorms to develop over our east-central and
southeastern counties, mainly during the afternoon. The 00Z GFS,
TTU WRF and HRRR models indicate this potential. Carrying a slight
chance PoP for the area southeast of a Sonora to Eden to Lake
Brownwood line. Have a lingering slight chance PoP this evening
until 9 PM for nearly the same area. This convection will be
diurnally driven and dissipate by sunset, with clear to partly
cloudy skies expected overnight.
The 850mb temperatures increase only slightly today, mainly across
the western part of our area. With this indication and an
anticipated increase in cloud cover, going with highs about the
same as yesterday across our eastern and central counties, and
around a degree warmer in our western counties. Lows tonight are
expected to be mostly in the upper 60s.
LONG TERM...
(Tuesday through Sunday)
The subtropical ridge axis currently runs in a general north-south
orientation along the front range, but will flatten over the
next few days as the large trough over the Great Basin ejects
shortwave energy over the crest of the ridge. Despite unimpressive
500 mb heights of 591-594 dam, a strong thermal ridge will reside
in the 850-700 mb layer, pushing temperatures well into the 90s
areawide, potentially reaching triple digits later this week. Min
temps will increase as well, with mid 70s anticipated by Thursday
morning. The general pattern will be an afternoon cumulus field
with clearing skies during the evening and overnight hours. Rain
chances will remain minimal due to the presence of the ridge and
dearth of deep moisture. That said, if any precipitation does
occur Tuesday through Thursday, it would more than likely be on
Tuesday afternoon.
The ECMWF and GEM are bringing a cold front south on Friday,
stalling the boundary in the vicinity of the Red River. The GFS,
however, maintains southerly flow well into the central plains. If
this boundary does verify, we`ll likely have to consider at
least a mention of isolated showers and thunderstorms Friday and
Saturday afternoon, despite the ridge being overhead. That said,
the juxtaposition of the front and the ridge appears unlikely.
Otherwise, expect the hot and generally dry conditions to
continue.
As we move through the weekend, both the GFS and ECMWF and ECMWF
are hinting that a TUTT low will develop and move across the
western Gulf of Mexico into south TX. With the upper-level ridge
centered over the region, this TUTT is likely to remain well to
our south, generally to far away to have much of an effect. If the
ridge is a bit weaker, this feature could yield isolated
convection Sunday into Monday. However, at this time, confidence is
far too low to include a mention in the forecast.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 69 94 72 97 / 5 10 5 5 5
San Angelo 93 68 95 72 98 / 5 10 5 5 5
Junction 92 69 94 71 96 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
159 PM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 140 PM EDT MONDAY...
FOG IS NOT AN ISSUE ANYMORE TODAY. HOWEVER...THE SAME MOISTURE
RESPONSIBLE FOR THE FOG...IS NOW BEING LIFTED THERMALLY DURING THE
HEATING OF THE DAY AND RESULTING IN CUMULUS CLOUDS ALIGNED
PARALLEL TO THE MOUNTAIN RIDGES. THE FORECAST STILL WILL REFLECT
THE POTENTIAL FOR SOME ISOLATED SHOWERS OR STORMS THIS AFTERNOON.
LATEST MESOSCALE MODELS OFFER PARTS OF SOUTHEAST WEST
VIRGINIA...THE NORTHERN MOUNTAINS OF NORTH CAROLINA INTO PARTS OF
THE MOUNTAIN EMPIRE REGION OF SOUTHWEST VIRGINIA...AND PARTS OF
SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA AS THE MOST LIKELY REGIONS FOR THIS ISOLATED CONVECTION
TO FIRE. THIS DIFFERS VERY LITTLE FROM OUR PREVIOUS FORECAST AND
SO ONLY MINOR TWEAKS IN THIS AREAL DEFINITION HAVE BEEN MADE.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
TO MATCH THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
AFTERNOON. BUMPED UP FORECAST HIGH TEMPERATURES FOR A FEW
LOCATIONS IN THE EAST BY A DEGREE OR TWO.
AS OF 940 AM EDT MONDAY...
FOG WILL CONTINUE TO ERODE THIS MORNING. MORNING SOUNDINGS SHOWING
ONLY A NARROW REGION ON MOISTURE AT OR BELOW 850 MB. ABOVE
THAT...VERY DRY AIR WAS IN PLACE. EXPECT MIXING TO CONTINUE TO
TAKE PLACE THIS MORNING WITH ANY REMAINING FOG DISSIPATED BY 1100
AM. REMAINDER OF THE FORECAST STILL LOOKS ON TRACK BASED UPON THE
EARLIER DISCUSSION.
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM EDT MONDAY...
MAINLY LOW END VFR CUMULUS FIELD HAS DEVELOPED ACROSS THE REGION
THIS AFTERNOON. A FEW POCKETS STILL MAY BE IN THE MVFR RANGE...BUT
SHOULD NOT BE FOR MUCH LONGER AS SURFACE TEMPERATURES RISE...AND
THUS THE LEVEL OF FREE CONVECTION. ISOLATED SHOWERS OR STORMS ARE
POSSIBLE LATE THIS AFTERNOON ALONG AN EAST OF A LINE FROM KLWB-
KBLF....BETWEEN KTNB AND KHLX...AND ALONG AND NEAR A KDAN-KFVX
LINE. ANY DEVELOPMENT IS NOT EXPECTED TO LAST MUCH LONGER THAN
SUNSET.
OVERNIGHT...MOUNTAIN VALLEY AND RIVER VALLEY FOG IS EXPECTED TO
REDEVELOP COMPARABLE TO WHAT OCCURRED THIS MORNING. A MIX OF
IFR/MVFR IS EXPECTED AFTER ROUGHLY 06Z/2AM TUESDAY AND LAST
THROUGH ROUGHLY 13Z/9AM TUESDAY.
VFR CONDITIONS ARE EXPECTED THROUGH THE MORNING AFTER THE FOG
MIXES OUT...BUT SOME LOCATIONS MAY DEVELOP A BRIEF MVFR CIG WHILE
TEMPERATURES WARM...AND EVENTUALLY LOW END VFR IS EXPECTED.
EXTENDED AVIATION FORECAST....
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE AREA WILL REMAIN WITH AN
UPPER TROUGH AXIS. ISOLATED...DAYTIME SHOWERS OR STORMS WILL BE
POSSIBLE ON MONDAY. BOTH NIGHTS...MOUNTAIN AND RIVER VALLEY FOG
WILL AGAIN BE POSSIBLE.
A COLD FRONT WILL APPROACH THE REGION ON WEDNESDAY. LOOK FOR
GREATER COVERAGE OF SHOWERS AND STORMS...ESPECIALLY IN THE WEST
AND NORTH. WEDNESDAY NIGHT...A GREATER PORTION OF THE AREA MAY
HAVE SUB-VFR CONDITIONS WHERE RAINS FALLS DURING THE DAY
WEDNESDAY.
THE FRONT WILL SETTLE SOUTH OF THE AREA THURSDAY INTO FRIDAY WITH
HIGH PRESSURE BUILDING IN BEHIND IT. THE BEST CHANCE OF ANY
ADDITIONAL PRECIPITATION WILL BE ACROSS THE SOUTHERN PORTION OF
THE REGION.
ON SATURDAY...A WAVE WILL MOVE EASTWARD ALONG THE FRONT AND BUCKLE
THE FRONT NORTH BACK INTO THE AREA...AND THUS BRING A RETURN TO A
GREATER COVERAGE OF SHOWERS AND STORMS TO THE AREA.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...DS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1245 PM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 140 PM EDT MONDAY...
FOG IS NOT AN ISSUE ANYMORE TODAY. HOWEVER...THE SAME MOISTURE
RESPONSIBLE FOR THE FOG...IS NOW BEING LIFTED THERMALLY DURING THE
HEATING OF THE DAY AND RESULTING IN CUMULUS CLOUDS ALIGNED
PARALLEL TO THE MOUNTAIN RIDGES. THE FORECAST STILL WILL REFLECT
THE POTENTIAL FOR SOME ISOLATED SHOWERS OR STORMS THIS AFTERNOON.
LATEST MESOSCALE MODELS OFFER PARTS OF SOUTHEAST WEST
VIRGINIA...THE NORTHERN MOUNTAINS OF NORTH CAROLINA INTO PARTS OF
THE MOUNTAIN EMPIRE REGION OF SOUTHWEST VIRGINIA...AND PARTS OF
SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA AS THE MOST LIKELY REGIONS FOR THIS ISOLATED CONVECTION
TO FIRE. THIS DIFFERS VERY LITTLE FROM OUR PREVIOUS FORECAST AND
SO ONLY MINOR TWEAKS IN THIS AREAL DEFINITION HAVE BEEN MADE.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
TO MATCH THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
AFTERNOON. BUMPED UP FORECAST HIGH TEMPERATURES FOR A FEW
LOCATIONS IN THE EAST BY A DEGREE OR TWO.
AS OF 940 AM EDT MONDAY...
FOG WILL CONTINUE TO ERODE THIS MORNING. MORNING SOUNDINGS SHOWING
ONLY A NARROW REGION ON MOISTURE AT OR BELOW 850 MB. ABOVE
THAT...VERY DRY AIR WAS IN PLACE. EXPECT MIXING TO CONTINUE TO
TAKE PLACE THIS MORNING WITH ANY REMAINING FOG DISSIPATED BY 1100
AM. REMAINDER OF THE FORECAST STILL LOOKS ON TRACK BASED UPON THE
EARLIER DISCUSSION.
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 730 AM EDT MONDAY...
SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWED AREAS OF MVFR
TO IFR FOG IN THE NEW AND GREENBRIER RIVER VALLEYS AND SOME FOG
AND STRATUS IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA. BUFKIT
SOUNDINGS INDICATED THE LAYER OF MOISTURE WAS SHALLOW. EXPECTING
THE FOG TO DISSIPATE BY MID MORNING. HIGH CONFIDENCE THAT
CONDITIONS WILL BE VFR BY 14Z/10AM.
MOSTLY LIGHT/VARIABLE THROUGH TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON...AS EAST LOW LEVEL
WINDS CREATE SOME CONVERGENCE NEAR THE BLUE RIDGE. THE CHANCE IS
TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
FOG IS EXPECTED TO DEVELOP AGAIN OVERNIGHT IN TYPICAL LOCATIONS.
MODERATE TO HIGH CONFIDENCE THAT VISIBILITY WILL LOWER TO AT LEAST
MVFR AT KLYH/KBCB AND KLWB AFTER MIDNIGHT.
EXTENDED AVIATION DISCUSSION...
A COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH SHOWER AND SOME THUNDERSTORMS IN ASSOCIATION WITH THE COLD
FRONT. LIKEWISE...MORE OVERNIGHT SUB- VFR CONDITIONS ARE LIKELY
WITH BOUNDARY LAYER MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. IF THERE IS LIMITED MOVEMENT OF THE FRONT BY
FRIDAY...EXPECT SIMILAR CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
238 PM MDT MON AUG 4 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY EVENING)
ISSUED AT 230 PM MDT MON AUG 4 2014
CURRENTLY...WATER VAPOR IMAGERY SHOWING MONSOONAL MOISTURE MOVING
INTO OUR WESTERN ZONES THIS AFTERNOON AS THE UPPER LOW THAT WAS
OVER SOUTHERN CALIFORNIA YESTERDAY MOVES INTO CENTRAL UTAH. 12Z
PWATS ON THE GJT SOUNDING OVER 1.2 INCHES. THIS MOISTURE IS HEADED
OUR WAY. MOSAIC RADAR SHOWING FAIRLY WIDESPREAD LIGHT RAIN OVER
CARBON COUNTY. A FEW THUNDERSTORMS DEVELOPING NEAR ARLINGTON AND
CENTENNIAL WITH A FEW LIGHTNING STRIKES OBSERVED. BEGINNING TO SEE
SOME CELLS DEVELOPING ON THE RADAR UP BY VEDAUWOO...SO SHOWERS
HERE AT CHEYENNE ARE NOT THAT FAR OFF.
FOR THIS AFTERNOON...LATEST HRRR FORECAST SHOWING CELLS DEVELOPING
OVER THE LARAMIE RANGE AND DRIFTING EAST. ITS SHOWING A FAIRLY
WIDESPREAD BAND OF SHOWERS AND THUNDERSTORMS MOVING SLOWLY EAST
INTO THE PANHANDLE AROUND THE 23Z TIME FRAME. STORMS ARE GOING TO
BE VERY SLOW MOVING...FROM THE SOUTHWEST AT UNDER 5KTS. THOSE
AREAS THAT DO EXPERIENCE THUNDERSTORMS THIS AFTERNOON AND THIS
EVENING COULD SEE CONSIDERABLE RAINFALL WITH THESE SLOW MOVING
STORMS.
UPPER SHORTWAVE MOVES BEST LIFT NORTH THIS EVENING...SO WE SHOULD
SEE A LULL IN CONVECTION AFTER 03Z OR SO UNTIL TUESDAY. DRIED OUT
THE SOUTHERN PANHANDLE AND SOUTHEAST WYOMING FROM LARAMIE TO
WHEATLAND TO TORRINGTON THIS EVENING.
NEXT PIECE OF ENERGY TO MOVE THROUGH THE AREA TUESDAY AFTERNOON
AND EVENING AS THE UPPER LOW OPENS UP AND TRACKS INTO WESTERN
WYOMING. NAM AND ECMWF SHOW GOOD QPF ACROSS MOST OF THE
CWFA...CONCENTRATED ACROSS THE SOUTHERN PANHANDLE AND LARAMIE
COUNTY TUESDAY AFTERNOON. STILL NOT MUCH IN THE STEERING FLOW...SO
STORMS WILL ONCE AGAIN BE SLOW MOVING AND PRODUCING MODERATE TO
HEAVY RAINFALL INTO TUESDAY EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 1222 PM MDT MON AUG 4 2014
WEDNESDAY...DESPITE A SHORTWAVE RIDGE ALOFT OVER OUR COUNTIES...WITH
A LOW LEVEL CONVERGENCE BOUNDARY INDICATED FROM DOUGLAS TO
CHEYENNE...ALONG WITH ADEQUATE LOW AND MID LEVEL MOISTURE AND DECENT
UPWARD VERTICAL MOTION FROM DOUGLAS TO CHEYENNE...HAVE BOOSTED
AFTERNOON AND EVENING POPS INTO THE 45 TO 70 PERCENT RANGE...WITH
LESSER POPS ELSEWHERE. WITH WEAK STEERING WINDS...WILL LIKELY SEE A
FEW HEAVY RAINERS AS WELL.
THURSDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES INTO WESTERN WYOMING
AND UTAH...WHILE A LOW LEVEL CONVERGENCE AXIS SETS UP FROM NORTH
CENTRAL COLORADO NORTHWARD TO NEAR TORRINGTON TO NEAR CHADRON.
850/700 MB THETA-E RIDGE AXIS...WELL PRONOUNCED...WILL EXTEND NORTH
TO SOUTH IN THE AFTERNOON ACROSS FAR EASTERN WYOMING AND WESTERN
NEBRASKA...AND WITH PROGGED INSTABILITIES...CAPE AND DECENT
DIRECTIONAL SHEAR...EXPECT A FEW STRONG TO SEVERE THUNDERSTORMS EAST
OF A LUSK TO CHEYENNE LINE...AND HAVE ALSO BOOSTED POPS EAST OF THIS
LINE TO THE 50 TO 60 PERCENT RANGE WITH ALL CONVECTIVE AND MESOSCALE
PARAMETERS COMING TOGETHER.
FRIDAY...LESS LATE DAY COVERAGE OF SHOWERS AND THUNDERSTORMS
EXPECTED WITH DECREASE IN LOW AND MID LEVEL MOISTURE...THOUGH WILL
STILL SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON AND EVENING WITH MOIST UPSLOPE MECHANICAL LIFT.
SATURDAY...SIMILAR SCENARIO TO FRIDAY...ALBEIT WITH SLIGHTLY LESS
COVERAGE OF SHOWERS AND THUNDERSTORMS DUE TO LESS LOW AND MID LEVEL
MOISTURE AVAILABILITY.
SUNDAY...RIDGING ALOFT STRENGTHENS OVER OUR COUNTIES...THUS EXPECT
SLIGHTLY LESS COVERAGE OF LATE DAY SHOWERS AND
THUNDERSTORMS...FOCUSED ALMOST EXCLUSIVELY OVER THE MOUNTAINS AND
HIGHER TERRAIN SUCH AS THE PINE RIDGE FROM NEAR LUSK TO NEAR CHADRON.
MONDAY...EVEN MORE PRONOUNCED RIDGING ALOFT...AND WITH THE BULK OF
THE MONSOONAL MOISTURE RESIDING OVER COLORADO...WILL ONLY FORECAST
ISOLATED LATE DAY THUNDERSTORMS OVER AND NEAR THE SNOWY...SIERRA
MADRE AND SOUTHERN LARAMIE RANGES...THOUGH WE WILL NEED TO WATCH FOR
POSSIBLE GREATER INTRUSION OF MID LEVEL MONSOONAL MOISTURE AS IS
TYPICAL FOR LATE JULY AND EARLY AUGUST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1057 AM MDT MON AUG 4 2014
EXPECT CONVECTION TO CONTINUE EXPANDING THIS AFTERNOON...IMPACTING
OUR SOUTHEAST WYOMING AIRPORTS. INITIALLY BEGINNING OVER
KRWL...THEN EXPANDING EASTWARD TO KLAR AND KCYS. SHOWERS COULD BE
HEAVY AT TIMES...REDUCING VISIBILITIES DOWN TO 3 MILES AT TIMES.
THIS CONVECTION WILL THEN SPREAD OUT INTO THE NEBRASKA PANHANDLE
SHORTLY BEFORE AND A FEW HOURS AFTER 00Z. LATEST SREF GUIDANCE
SHOWING MVFR/IFR CEILINGS DEVELOPING IN THE NORTHERN NEBRASKA
PANHANDLE...IMPACTING KCDR AND POSSIBLY KAIA TUESDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 230 PM MDT MON AUG 4 2014
MONSOONAL MOISTURE WILL STAY WITH US THROUGH MOST OF THE WEEK
GIVING MOST AREAS CHANCES FOR WETTING RAINS AND THUNDERSTORMS ON A
DAILY BASIS. WINDS TO REMAIN WEAK AND AFTERNOON HUMIDITIES FAIRLY
HIGH...MITIGATING ANY FIRE WEATHER CONCERNS. MIN HUMIDITIES
EXPECTED TO STAY IN THE MID 20 PERCENT RANGE THROUGH THE WEEK WITH
EXCELLENT OVERNIGHT RECOVERIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB