Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 09/02/13

AREA FORECAST DISCUSSION

NWS TUCSON AZ

 910 AM MST SAT AUG 31 2013

.SYNOPSIS...EXPECT ISOLATED TO SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS THIS HOLIDAY WEEKEND AND DURING THE UPCOMING
WEEK. A WARMING TREND WILL ALSO OCCUR THROUGH TUESDAY FOLLOWED BY
ABOVE AVERAGE DAYTIME TEMPERATURES LATER IN THE WEEK.

&&

.DISCUSSION...CLEAR SKIES OR MOSTLY CLEAR SKIES WERE ONGOING ACROSS
GREENLEE/GRAHAM/COCHISE COUNTIES WITH PARTLY CLOUDY SKIES TO CLOUDY
SKIES FROM TUCSON WWD. AMPLE MOISTURE CONTINUES ACROSS SE AZ WITH
DEWPOINTS VALID 16Z GENERALLY IN THE 60S. 31/12Z KTWC SOUNDING TOTAL
PRECIP WATER WAS 1.64 INCHES...AND THE BLENDED TOTAL PRECIP WATER
IMAGERY PRODUCT DEPICTED VALUES RANGING FROM 1.25 INCHES NEAR THE
NEW MEXICO BORDER TO NEARLY 2.00 INCHES ACROSS FAR WRN PIMA COUNTY.
31/12Z UPPER AIR PLOTS DEPICTED EXPANSIVE RIDGE ALOFT ACROSS THE
WESTERN AND CENTRAL CONUS...AND A VERY WEAK MID-LEVEL STEERING FLOW
OVER SE AZ.

31/12Z NAM AND 31/14Z RUC HRRR WERE SIMILAR WITH DEPICTING SHOWERS/
TSTMS THIS AFTERNOON AND THIS EVENING TO BE CONFINED TO MAINLY NEAR
THE MOUNTAINS. ANOTHER SOMEWHAT PROMINENT AREA FOR SHOWERS/TSTMS IS
PROGGED TO BE ACROSS SANTA CRUZ/SWRN COCHISE COUNTIES. THE BULK OF
SHOWERS/TSTMS SHOULD END BY AROUND MIDNIGHT. HOWEVER...ENOUGH
MOISTURE EXISTS TO JUSTIFY A SLIGHT CHANCE OF SHOWERS ACROSS THE
AREA LATE TONIGHT.

HIGH TEMPS TODAY WILL BE SIMILAR TO FRI...AND WILL AVERAGE A FEW
DEGS BELOW NORMAL. PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION
BELOW FOR ADDITIONAL DETAIL.

&&

.PREV DISCUSSION /333 AM MST SAT AUG 31 2013/...MUCH DRIER AND
WARMER ON SUNDAY...THE FIRST DAY OF METEOROLOGICAL FALL...WITH
PRECIPITABLE WATER VALUES PROGGED TO BE LESS THAN ONE INCH EAST OF
TUCSON TO 1.5" IN THE WEST, ONLY EXPECTING ISOLATED COVERAGE WITH
BEST CHANCES UP IN THE WHITES.

MONDAY...A LITTLE MORE AREAL COVERAGE IN STORMS AS SOME THE AREA
PICKS UP A BIT OF MOISTURE FROM THE SOUTH. HIGHS A COUPLE DEGREES
WARMER THAN SUNDAY.

TUESDAY...MID-LEVEL EASTERLY STEERING FLOW INCREASES ACROSS THE AREA
AS INVERTED TROF PUSHES ACROSS NORTHERN MEXICO. THIS SHOULD LEAD TO
AN INCREASE IN AREAL COVERAGE OF STORM. CURRENT POP FORECAST MAY BE
UNDERDONE.

WEDNESDAY THROUGH FRIDAY...DRIER AIR PUSHES BACK ACROSS THE AREA
LIMITING THUNDERSTORM ACTIVITY TO ISOLATED COVERAGE.

&&

.AVIATION...ISOLD-SCTD TSRA/SHRA INTO THIS EVENING FOLLOWED BY ISOLD
-SHRA LATE TONIGHT AND SUNDAY MORNING. THE STRONGER TSRA WILL
PRODUCE MVFR CIGS/VSBYS AND WIND GUSTS TO NEAR 40 KTS. OTHERWISE...
SURFACE WIND MOSTLY LESS THAN 10 KTS THRU SUNDAY MORNING OR 01/18Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...SCATTERED SHOWERS AND THUNDERSTORMS WILL PREVAIL
DURING THE UPCOMING WEEK. STRONG...GUSTY AND ERRATIC WINDS WILL
OCCUR WITH THE STRONGER AFTERNOON THUNDERSTORMS. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS DURING THE UPCOMING WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON






AREA FORECAST DISCUSSION

NWS TAUNTON MA

 1001 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A STALLED FRONTAL BOUNDARY STRETCHING FROM NEW YORK STATE INTO NEW
ENGLAND WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES
TODAY AND SUNDAY. SHOWERS AND THUNDERSTORMS MAY BECOME MORE
WIDESPREAD MONDAY INTO EARLY TUESDAY AS A COLD FRONT MOVES ACROSS
THE REGION. DRIER...COOLER AND MUCH LESS HUMID WEATHER ARRIVES
MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...SCATTERED SHOWERS CONTINUE MAINLY COMING OFF OF THE
BERKSHIRES THIS MORNING. PLENTY OF MOISTURE /PWATS 1.5 TO 1.8
INCHES/ AND DECENT INSTABILITY /MUCAPE VALUES AROUND 1000 J/KG/ WILL
ALLOW THESE SHOWERS TO CONTINUE AT LEAST FOR THE NEXT SEVERAL
HOURS. OVERCAST SKIES IN PLACE WILL LIMIT ANY FURTHER
DESTABILIZATION GOING INTO THE AFTERNOON. IF CLOUDS BREAK UP AT
ALL DURING THE AFTERNOON...SHOWERS AND THUNDERSTORMS MAY
REDEVELOP. MADE SOME MINOR UPDATES TO THE POP/WX GRIDS TO ACCOUNT
FOR THE LATEST TRENDS WITH THE SHOWERS THIS MORNING.

PREVIOUS DISCUSSION...
SHORTWAVE TROUGH OVER THE EASTERN GREAT LAKES AND NY STATE EARLY
THIS MORNING DEAMPLIFIES AS IT APPROACHES AND MOVES ACROSS NEW
ENGLAND TODAY. THIS IS EVIDENT IN WEAKENING WIND FIELDS
ALOFT...LESS CURVATURE IN THE MID LEVEL FLOW/STREAMLINES AND
WEAKENING Q-VECTOR CONVERGENCE ALONG AND AHEAD OF THE MID LEVEL
TROUGH. LAST FEW RUNS OF THE HRRR OFFER THE SAME THEME WITH
WEAKENING REFLECTIVITY AS CONVECTION APPROACHES NEW ENGLAND.
THEREFORE EXPECTING UPSTREAM CONVECTION ACROSS NY STATE AND VT TO
SLOWLY WEAKEN AS IT APPROACHES AND ENTERS SOUTHERN NEW ENGLAND.

HOWEVER THINK NEW CONVECTION WILL REFIRE OVER THE AREA THIS
AFTERNOON AS SOME SUNSHINE TODAY DESTABILIZES THE ATMOSPHERE WITH
THE MORE CONSERVATIVE ECMWF AND GEFS OFFERING CAPES ON THE ORDER OF
1200-1800J/KG. FAIRLY CONFIDENT IN THIS SCENARIO AS ALL MOS GUIDANCE
HAVE HIGH TEMPS TODAY IN THE LOW TO MID 80S...WITH WARMEST
READINGS ACROSS NORTHEAST MA AND SOUTHEAST NH. THIS INSTABILITY
COMBINED WITH WEAK BUT MOIST CYCLONIC FLOW ALOFT SHOULD BE
SUFFICIENT TO YIELD SCATTERED THUNDERSTORMS. HIGHEST PROBABILITY
WILL BE ACROSS THE INTERIOR...CLOSER TO FRONTAL BOUNDARY AND
SURFACE CONVERGENCE. THUS CONVECTION SHOULD BE LESS WIDESPREAD ACROSS
SOUTHEAST MA /INCLUDING CAPE COD AND THE ISLANDS/ AND POSSIBLY
INTO BOSTON-PROVIDENCE CORRIDOR. MAIN ISSUE WITH ANY TSTMS TODAY
WILL BE HEAVY DOWNPOURS/FLOOD POTENTIAL WITH PWATS JUST UNDER 2
INCHES ALONG WITH WEAK WINDS ALOFT RESULTING IN SLOW MOVING
STORMS. TIMING OF STORMS WILL BE AFTER 16Z AND SPECIFICALLY DURING
PEAK HEATING FROM 18Z-21Z.

IT WILL BE WARM AND HUMID TODAY AS SOUTHERN NEW ENGLAND WILL BE IN
THE WARM SECTOR OF THE APPROACHING FRONTAL SYSTEM. DEW PTS WILL
CLIMB INTO THE U60S AND L70S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
EARLY EVENING SHOWERS/TSTMS ACROSS THE INTERIOR SHOULD DISSIPATE
WITHIN A FEW HOURS OF SUNSET GIVEN THE LACK OF DEEP LAYER SHEAR
AND MID LEVEL LAPSE RATES NEEDED TO SUSTAIN NOCTURNAL CONVECTION.
HOWEVER CAN/T RULE OUT ISOLATED OR WIDELY SCATTERED SHOWERS
OVERNIGHT GIVEN THE WEAK BUT MOIST CYCLONIC FLOW ALOFT.

SOUTHERN NEW ENGLAND REMAINS IN THE WARM SECTOR SO EXPECT PATCHY FOG
AND LOW CLOUDS. HIGH DEW PTS WILL YIELD ANOTHER MILD TO WARM NIGHT.

SUNDAY...
WEAK SHORTWAVE RIDGING MAY MOVE ACROSS THE REGION BEHIND
DEPARTING SHORTWAVE TROUGH OF TODAY AND BEFORE NEXT TROUGH
APPROACHES SUN NGT AND MON. THIS IS EVIDENT ON MODEL CROSS AND
TIME SECTIONS WITH COLUMN DRYING OUT IN THE MID AND UPPER LEVELS.
SO WHILE THERE IS STILL SOME UNCERTAINTY TO SUNDAY/S
FORECAST...THERE IS INCREASING CONFIDENCE THAT ANY SHOWER/TSTM
ACTIVITY WILL NOT BE WIDESPREAD. THUS NOT EXPECTING A WASHOUT
SUNDAY.

THE AREA REMAINS IN THE WARM SECTOR SO ANOTHER WARM AND MUGGY DAY
WITH HIGHS 80-85 AWAY FROM THE COAST ALONG WITH DEW PTS IN THE U60S
AND L70S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

  * SHOWERS AND THUNDERSTORMS LIKELY ON MONDAY AND INTO TUESDAY
  * SLOW MOVING COLD FRONT WILL CROSS THE REGION ON TUESDAY
  * FALL LIKE CONDITIONS FOR THE SECOND HALF OF THE WORK WEEK

CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN OVERALL FORECAST. CONTINUE TO HAVE
INCREASING CONFIDENCE FOR THE TEMPERATURE ASPECT IN THE FORECAST.
MODERATE CONFIDENCE IN TIMING OF PRECIPITATION WITH HIGH
CONFIDENCE THAT PRECIP WILL OCCUR MONDAY AND EARLY TUESDAY. THE
00Z MODELS MAINTAIN A NEARLY STEADY-STATE TO SLIGHTLY RETROGRADING
PATTERN IN THE LOWER HALF OF THE CONUS WITH AN UPPER HIGH OVER THE
CENTRAL/SOUTHERN PLAINS. WHILE ACROSS THE NORTHEAST A PROGRESSIVE
FLOW INFLUENCED BY MULTIPLE SHORTWAVES AND FRONTAL PASSAGES WILL
RESULT IN GENERALLY COOLER TEMPERATURES. HOWEVER THE
DETAILS/TIMING ARE AN ISSUE DUE TO THE PATTERNS SHORT WAVELENGTH
AND POSSIBILITY OF PHASING. THAT BEING SAID FELT PERSISTENCE WAS
A GOOD WAY TO GO FOR THIS MORNINGS FORECAST. BLENDED PREVIOUS
FORECAST WITH WPC AND THE ENSEMBLES.

DETAILS...

MONDAY...
LONG WAVE TROUGH WILL SHARPEN UP ON MONDAY AS HUDSON BAY LOW
PRESSURE STRENGTHENS. THIS WILL KEEP THE REGION IN A SOUTHWEST
FLOW WITH INCREASING MOISTURE CAUSING VERY MUGGY CONDITIONS. MAIN
FOCUS IS A COLD FRONT ACROSS THE GREAT LAKES THAT WILL APPROACH
THE REGION. HOWEVER A SHORTWAVE WILL MOVE THROUGH THE FLOW ON
MONDAY WHICH WILL SPARK SOME SHOWERS AND THUNDERSTORMS. THE REGION
WILL BE IN THE WARM...MOIST SECTOR AS WELL AS THE BETTER JET
DYNAMICS. MAIN THREAT WITH THESE STORMS WILL BE HEAVY RAIN AS PWAT
VALUES WILL BE ABOVE 2 INCHES. THESE STORMS WILL BE SLOW MOVING
AND/OR TRAINING AS CORFIDI VECTORS ARE AROUND 0-5 KTS. NOTICED SPC
PUT THE REGION IN A SEE TEXT FOR DAY THREE OUTLOOK. HAVE LOW
CONFIDENCE IN OVERALL SEVERE WEATHER THREAT AS INSTABILITY VALUES
WILL BE LOWER THAN MODELS SUGGEST DUE TO THE AMOUNT OF CLOUDS
ACROSS THE AREA. THIS IDEA IS ALSO SUPPORTED BY THE ENSEMBLES.
THEREFORE BELIEVE THAT THE MAIN THREAT WILL STILL BE HEAVY RAIN
CAUSING SOME URBAN AND POOR DRAINAGE FLOODING. SMALL STREAM LEVELS
MAY ALSO RISE IF THUNDERSTORMS TRAIN OVER CERTAIN REGIONS. THIS
PORTION OF THE FORECAST WILL NEED TO BE WATCHED CLOSELY OVER THE
WEEKEND.

TUESDAY...
COLD FRONT WILL MOVE THROUGH SOUTHERN NEW ENGLAND ON TUESDAY.
MAIN QUESTION IS THE TIMING. IF THE FRONT SLOWS DOWN THEN THERE IS
A CHANCE FOR SHOWERS AND THUNDERSTORMS TO DEVELOP ESP ACROSS THE
EASTERN HALF OF THE REGION. IF THE FRONT SPEEDS UP THEN ONLY A FEW
SHOWERS MAY OCCUR AS THE FRONT EXITS OFFSHORE. REGARDLESS HAVE A
LOWER CONFIDENCE ON ANY STRONG STORMS ON TUESDAY AS BETTER JET
DYNAMICS WILL BE OFFSHORE. BOTH THE ENSEMBLES INDICATE THE BETTER
MOISTURE IS OFFSHORE AS WELL. TRENDED TOWARDS A FASTER SOLUTION ON
TUESDAY. A FEW HEAVY SHOWERS ARE STILL POSSIBLE WITH MAIN CONCERN
BEING NUISANCE FLOODING.

WEDNESDAY THROUGH FRIDAY...
LARGE-SCALE SUBSIDENCE WILL FILTER IN BEHIND THE FRONT ON
WEDNESDAY. THIS WILL DROP DEWPOINTS DOWN INTO THE 40/50S MAKING IT
VERY COMFORTABLE. A FEW SHOWERS ARE POSSIBLE ACROSS THE NW ZONES
FROM WRAP AROUND MOISTURE FROM THE LOW. OTHERWISE EXPECT MOSTLY
DRY CONDITIONS. MODELS ARE INDICATING A POLAR FRONT WILL MOVE
THROUGH ON THURSDAY BRINGING SOME ISOLATED/SCATTERED SHOWERS. HAVE
A LOWER CONFIDENCE AS THERE IS A GOOD AMOUNT OF DRY AIR ACROSS THE
AREA. BEHIND THIS FRONT IS A MORE FALL LIKE AIRMASS BRINGING
OVERNIGHT LOWS IN THE 40S AND HIGHS ONLY IN THE 60S.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...LOW TO MODERATE CONFIDENCE ON EXACT DETAILS INCLUDING
TIMING...BUT HIGHER CONFIDENCE ON OVERALL FORECAST THEME. CIGS AND
VSBYS WERE DERIVED FROM A BLEND OF NAM AND GFS MOS.

TODAY...
MVFR/IFR CONDITIONS ARE FAIRLY WIDESPREAD THIS MORNING WITH VFR
CONDITIONS LIMITED TO SOUTHEASTERN NEW HAMPSHIRE. VSBYS SHOULD
IMPROVE TO VFR BY 16Z WHILE CIGS WILL REMAIN MVFR/IFR FOR SEVERAL
MORE HOURS...PARTICULARLY ACROSS SE MA AND RI. SHOWERS CONTINUE
THIS MORNING. ADDITIONAL SHOWERS AND TSTMS WILL DEVELOP AFTER 16Z
MAINLY INLAND WITH DAYTIME HEATING SHOULD THE SUN BREAK THROUGH
THE CLOUDS AT ALL.

TONIGHT...
ALMOST A REPEAT PERFORMANCE...IFR IN LOW CLOUDS CONFINED TO
SOUTHEAST MA AND RI WITH MVFR/VFR ELSEWHERE. ISOLATED/SCATTERED
SHOWERS SHOULD BE MOST NUMEROUS WELL INLAND.

SUNDAY...
IFR SOUTHEAST MA AND RHODE ISLAND BUT IMPROVING TOWARD MIDDAY TO
VFR. VFR ELSEWHERE. NOT EXPECTING WIDESPREAD SHOWERS/TSTMS...MORE
ISOLATED TO WIDELY SCATTERED.

KBOS TERMINAL...HIGH CONFIDENCE ON TRENDS. LOW CONFIDENCE ON
TIMING.  BULK OF LOW CLOUDS SHOULD SLIDE SOUTH OF THE AIRPORT.
SHOWERS THIS MORNING MAY AFFECT THE AIRPORT AT TIMES THROUGH THE
MORNING. ANY SHOWERS/THUNDERSTORMS THAT DEVELOP THIS AFTERNOON
SHOULD REMAIN NORTH AND WEST OF THE AIRPORT.

KBDL TERMINAL...HIGH CONFIDENCE ON TRENDS. LESS CONFIDENT ON
TIMING. SHOWERS/TSTMS WILL BECOME MORE NUMEROUS 16Z- 22Z.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

SUNDAY NIGHT...MODERATE CONFIDENCE. EXPECT MAINLY MVFR CIGS/VFR
VSBYS. AREAS MVFR VSBYS IN ANY SHOWERS/TSTMS. LOCAL IFR VSBYS IN
ANY HEAVIER RAINFALL.

MONDAY-TUESDAY...LOW CONFIDENCE MAINLY FOR TIMING. MVFR
CONDITIONS WITH IFR IN SHOWERS/TSTMS. PERIODS OF HEAVY RAINFALL
WILL REDUCE VSBYS AS WELL.

WEDNESDAY...HIGH CONFIDENCE. MVFR TO START...IMPROVING TO VFR BY
THE AFTERNOON HOURS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TODAY THROUGH SUNDAY...
MODEST SW WIND 10-15 KT WITH GUSTS AROUND 20 KT LIKELY.
WARM/MUGGY AIRMASS WILL YIELD LATE NIGHT/EARLY MORNING FOG.
SHOWERS LIKELY ON THE EASTERN WATERS THIS MORNING INTO THIS
AFTERNOON.  THEN SHOWERS/TSTMS WILL BE MAINLY INLAND. FORECAST
CONFIDENCE MODERATE TO HIGH.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

PERSISTENT SOUTHERLY SWELL COMBINED WITH AN APPROACHING COLD
FRONT WILL CAUSE SEAS TO BUILD UP TO 5 FT ESP ACROSS THE OUTER
WATERS THROUGH TUESDAY. BELIEVE THIS IS A LITTLE HIGH SO HAVE
UNDERCUT WAVE GUIDANCE TO TOP OUT AT 4FT. LOW PROB FOR GUSTS UP TO
25 KT AHEAD OF COLD FRONT MON NIGHT AND EARLY TUE. EXPECT COLD
FRONT TO MOVE ACROSS WATERS LATE TUE/TUE NIGHT. WINDS/SEAS SHOULD
SLOWLY DIMINISH DURING WED. BEST CHANCE FOR THUNDERSTORMS WILL BE
MONDAY INTO TUESDAY MORNING.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...NOCERA/DUNTEN/RLG
SHORT TERM...NOCERA
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN




AREA FORECAST DISCUSSION

NWS ALBANY NY

 741 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM AND HUMID AIR MASS WILL IMPACT EASTERN NEW YORK
AND WESTERN NEW ENGLAND THROUGH THE HOLIDAY WEEKEND.  A SERIES OF
WEAK DISTURBANCES MOVING ALONG A FRONTAL BOUNDARY NEAR THE SAINT
LAWRENCE RIVER VALLEY WILL PRODUCE SHOWERS AND THUNDERSTORMS TODAY
WITH SOME LOCALLY HEAVY RAINFALL.  THE UNSETTLED WEATHER CONTINUES
LATE SUNDAY INTO LABOR DAY WHEN A STRONG UPPER LEVEL LOW BRINGS MORE
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS TO THE REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 655 AM EDT...THE LAST FULL DAY OF AUGUST AND METEOROLOGICAL
SUMMER BEGAN WITH SHOWERS AND SCT THUNDERSTORMS ACROSS PORTIONS OF
THE ALY FCST AREA...ESPECIALLY FROM THE NRN CATSKILLS...CAPITAL
REGION AND SRN VT NORTHWARD. A COUPLE OF WEAK SFC LOWS ARE MOVING
ALONG A STATIONARY FRONT NEAR THE ST LAWRENCE RIVER VALLEY AND ERN
GREAT LAKES THIS MORNING. LOW-LEVEL CONVERGENCE WITH THE SFC LOWS
HAS HELPED THE SHOWERS AND THUNDERSTORMS BE THE MOST PERSISTENT IN
THE MOHAWK RIVER VALLEY...SRN DACKS...AND THE LAKE GEORGE SARATOGA
REGION. THIS ACTIVITY WILL CONTINUE TO WANE EARLY THIS MORNING...AND
A BRIEF LOW WILL OCCUR TOWARDS NOONTIME. THE POPS WERE RETRENDED
THIS MORNING BASED ON THE RADAR TRENDS.

A MAJORITY OF THE GUIDANCE SHOWS ANOTHER WEAK RIPPLE OF LOW
PRESSURE MOVING ALONG THE BOUNDARY IN THE AFTERNOON WITH A MID
LEVEL SHORT-WAVE IN THE W/SW FLOW ALOFT. IT IS QUESTIONABLE IF ANY
SIGNIFICANT HEATING WILL OCCUR EXCEPT PERHAPS ALONG THE SRN TIER
OF THE FCST AREA /MID HUDSON VALLEY AND NW CT/. THE 0-6 KM DEEP
SHEAR IS WEAK WITH WEAK MID LEVEL LAPSE RATES ALOFT...SO
WIDESPREAD SEVERE CONVECTION IS NOT ANTICIPATED DESPITE SBCAPE
VALUES OF 1000-2000 J/KG ACCORDING THE NAM/GFS. H850 THETA-E
VALUES WILL BE GENERALLY IN THE 335-340K RANGE. THE PWATS WILL BE
IN THE 1.25-1.75 INCH RANGE /1 TO 2 STANDARD DEVIATIONS ABOVE
NORMAL/...SO LOCALLY HVY RAINFALL WILL BE THE MAIN ISSUE. THE
ENHANCED WORDING WAS PUT IN THE GRIDS...AND WILL BE MENTIONED IN
THE HWO. IF THE HIGHER CAPE VALUES ARE REALIZED...AN ISOLATED WET
MICROBURST MAY BE POSSIBLE. THE MAIN THREAT CONTINUES TO BE HEAVY
RAINFALL. THE HIGHEST POPS IN THE LIKELY RANGE WERE USED ACROSS
THE NRN HALF OF THE FCST AREA.

THE 07Z 3KM HRRR COLUMN REF PRODUCT SHOWS DISCRETE CONVECTIVE
ELEMENTS FORMING INTO A LINE OVER THE HUDSON RIVER VALLEY IN THE
MID AFTERNOON. IN A WEAK SHEAR ENVIRONMENT THIS APPEARS TO BE OFF
SOME...BUT WILL HAVE TO BE MONITORED. LATER RUNS HAVE SHOWN LESS
SIGNIFICANT COVERAGE AND ORGANIZATION.

THE SFC DEWPTS WILL REMAIN IN THE 60S WITH PERHAPS SOME SPOTTY
LOWER 70S OVER THE SRN TIER. THE AIR MASS WILL BE STICKY FOR THE
LAST DAY OF AUGUST. MINIMAL HEATING SHOULD ALLOW FOR U70S TO L80S
IN THE VALLEYS...WITH 70S OVER THE HILLS AND MTNS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
TONIGHT...THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN THE
EARLY EVENING WITH THE WEAK SFC WAVE MOVING EAST/NORTHEAST OF THE
REGION...AND THE MID LEVEL SHORT-WAVE PASSING DOWNSTREAM. THE
FRONTAL BOUNDARY MAY MOVE OVER THE NRN HALF OF THE FCST AREA AND
FALL APART. THE POPS WERE LOWERED TO SLIGHT CHC VALUES AFTER
MIDNIGHT. IT WILL REMAIN VERY HUMID WITH LOWS IN THE MID AND U60S
OVER MOST OF THE REGION...EXCEPT OVER THE MTNS.

SUNDAY...THE ENTIRE DAY SHOULD NOT BE A WASHOUT WITH AN AMPLIFYING
UPPER LEVEL TROUGH OVER ONTARIO AND THE GREAT LAKES REGION. THE
MID LEVEL FLOW WILL BECOME SOUTHWESTERLY OVER NY AND NEW ENGLAND
WITH WEAK RIDGING ALOFT. THEIR ARE NOT ANY REAL ROBUST SYNOPTIC
TRIGGER MECHANISMS DURING THE DAY. AIR MASS OR DIFFERENTIAL
HEATING THUNDERSTORMS ARE POSSIBLE. A SLIGHT TO LOW CHANCE OF
SHOWERS AND THUNDERSTORMS WAS INCLUDED IN THE GRIDS. H850 TEMPS
INCREASE TO +16C TO +17C WITH PARTLY SUNNY CONDITIONS. MAX TEMPS
WILL RUN ABOUT 5-10 DEGREES ABOVE NORMAL TO OPEN SEPT.

SUNDAY NIGHT INTO LABOR DAY...A LARGE TROUGH OF LOW PRESSURE
IMPACTS THE REGION. SEVERAL MID LEVEL SHORT-WAVES ROTATING AROUND
THE CLOSED LOW SOUTH OF JAMES BAY WILL YIELD UNSETTLED WX DURING
THIS TIME FRAME. IT IS DIFFICULT TO DETERMINE IF ANY ROBUST SFC
HEATING WILL OCCUR AT THIS TIME. THE STRONG SYNOPTIC LIFT WITH THE
TROUGH WILL LIKELY YIELD PERIODS OF SHOWERS AND SCT THUNDERSTORMS.
SOME HVY RAINFALL LOOKS LIKE A GOOD BET. THE QG LIFT INCREASES
LABOR DAY AFTERNOON...AS THE NRN HALF OF THE FCST AREA GETS NEAR
THE RIGHT ENTRANCE REGION OF A H250 JET STREAK WITH STRONG UPPER
LEVEL DIVERGENCE ALOFT. PWATS CONTINUE ABOVE NORMAL FOR EARLY
SEPT. LIKELY POPS WERE CONTINUED ON MONDAY. THE COOLER NAM MOS
TEMPS WERE ALSO FOLLOWED CLOSELY WITH THE AMOUNT OF CLOUD COVER
AND NUMEROUS SHOWERS EXPECTED. MAX TEMPS WILL BE HARD PRESSED TO
GET OUT OF THE 70S WITH PERHAPS SOME 80F READINGS FROM THE CAPITAL
REGION SOUTH IN THE MID HUDSON VALLEY.

MONDAY NIGHT...LOW AND MID LEVEL HEIGHTS CONTINUE TO FALL...AS THE
TROUGH OF LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MIGRATE EAST
OF THE REGION. A CHC OF SHOWERS WAS KEPT IN MOST OF THE OVERNIGHT.
LOW LEVEL COLD ADVECTION IS EXPECTED WITH TEMPS FALLING INTO THE
50S OVER THE MTNS WITH LOWER TO MID 60S IN THE VALLEYS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
COOLER AND LESS ACTIVITY WEATHER AS WE HEAD THROUGH THE FIRST WEEK
OF SEPTEMBER.

THE MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT REGARDING THE
LONGWAVE PATTERN WITH THE NORTHEAST REMAINING UNDER A TROUGH AND
THE RIDGE HOLDING ON OVER THE PLAIN STATES.

A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE REGION. THE FIRST ONE
IS EXPECTED TO MOVE OFF TO OUR EAST ON TUESDAY WITH SOME LINGERING
SHOWERS POSSIBLE MAINLY DURING THE MORNING. A PLEASANT DAY EXPECTED
WEDNESDAY AS HIGHER PRESSURE BUILDS IN WITH SEASONABLE WARM
TEMPERATURES. A SECONDARY COLD FRONT IS EXPECTED TO MOVE THROUGH
THURSDAY WITH ISOLATED SHOWERS. A MORE AUTUMN-LIKE AIRMASS WILL BE
USHERED IN AS CANADIAN HIGH PRESSURE BUILDS IN ITS WAKE OF THE FRONT
TO CLOSE OUT THE WEEK. TEMPERATURES THURSDAY AND FRIDAY ARE
ANTICIPATED TO RUN ABOUT 5 DEGREES BELOW NORMAL.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SOME SHOWERS CONTINUE TO MOVE EASTERLY ACROSS THE FORECAST AREA
EARLY THIS MORNING IN ASSOCIATION WITH A PASSING SHORT WAVE TROUGH
AND WEAK SURFACE LOW MOVING INTO THE SAINT LAWRENCE RIVER VALLEY.
EXPECT A LULL IS THE PRECIPITATION FOR A BIT THIS MORNING AS THE
SHORT WAVE TROUGH MOVES OFF TO THE EAST. HOWEVER...CHANCES FOR
CONVECTION WILL INCREASE AS HEAD INTO THE AFTERNOON AS THE SURFACE
LOW PASSES TO OUR NORTH AND ANOTHER SHORT WAVE TROUGH APPROACHES.
WITH THE HELP OF DIURNAL HEATING AND INCREASED INSTABILITY THERE WILL
BETTER CHANCES FOR SHOWERS AND THUNDERSTORMS. DO NOT HAVE CONFIDENCE
TO TIME THUNDERSTORMS AT INDIVIDUAL TAF SITES SO HAVE RUN WITH A
TEMPO GROUP FOR SHOWERS TO HIGHLIGHT MOST LIKELY TIME FOR CONVECTION
TO OCCUR.

ALTHOUGH LOW VSBYS/CIGS ARE ALLOWING FOR OCCASIONAL IFR AND MVFR
CONDITIONS EARLY THIS MORNING...AN IMPROVEMENT TO VFR CONDITIONS
IS EXPECTED BY LATE THIS MORNING. MVFR WITH BRIEF IFR CONDITIONS
ARE EXPECTED WITH ANY CONVECTION THAT IMPACTS TAF SITES TODAY.
MVFR/IFR FOG/CIGS ARE EXPECTED TO DEVELOP TONIGHT...ESPECIALLY WHERE
IT RAINS.

OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
LABOR DAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: LOW OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY NIGHT-WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.

&&

.FIRE WEATHER...
NO FIRE WEATHER PROBLEMS ARE EXPECTED IN THE HUMID AIR MASS WITH
SEVERAL CHANCES OF RAINFALL.

A SERIES OF WEAK DISTURBANCES MOVING ALONG A FRONTAL BOUNDARY
NEAR THE SAINT LAWRENCE RIVER VALLEY WILL PRODUCE SHOWERS AND
THUNDERSTORMS TODAY WITH SOME LOCALLY HEAVY RAINFALL. THE
UNSETTLED WEATHER CONTINUES LATE SUNDAY INTO LABOR DAY WHEN A
STRONG UPPER LEVEL LOW BRINGS MORE WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS TO THE REGION.

THE RH VALUES WILL ONLY DROP TO BETWEEN 50 AND 85 PERCENT THIS
AFTERNOON...AND RECOVER TO CLOSE TO 100 PERCENT SUNDAY MORNING.
HIGH RH VALUES OF 55 TO 75 PERCENT WILL OCCUR SUNDAY AFTERNOON.

THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TODAY
AND TOMORROW... AND BECOME LIGHT TO CALM TONIGHT.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED THE NEXT 5 DAYS ON
THE MAIN STEM RIVERS. HEAVY RAINFALL WITH LOCALIZED IMPACTS WILL BE
POSSIBLE TODAY THROUGH LABOR DAY FROM SHOWERS AND THUNDERSTORMS.
THE BEST CHANCE FOR WIDESPREAD RAINFALL WILL BE TODAY AND ON
LABOR DAY.

HUMID CONDITIONS WILL PERSIST...SO LOCALIZED DOWNPOURS CAN BE
EXPECTED WITH THUNDERSTORMS. ISOLATED URBAN...SMALL STREAM...AND
POOR DRAINAGE FLOODING WILL BE POSSIBLE DURING THE HOLIDAY
WEEKEND. SOME WITHIN BANK RISES ARE POSSIBLE ON LARGER STREAMS
WHERE SHOWERS AND STORMS OCCUR. ZONAL FFG VALUES REMAIN HIGH
DURING THIS TIME FRAME. HOWEVER...A QUICK INCH OR TWO OF RAINFALL
FROM A SLOW MOVING THUNDERSTORM MAY PRODUCE AN ISOLATED FLASH
FLOOD DURING THE HOLIDAY WEEKEND.

RAINFALL AMOUNTS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE
OF THE RAIN...WITH SOME LOCATIONS RECEIVING OVER AN INCH OF RAIN
WHILE OTHERS REMAIN DRY. SOME AREAS NORTH OF THE CAPITAL REGION
HAVE RECEIVED A HALF AN INCH TO AN INCH OF RAINFALL THIS MORNING.

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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA/FRUGIS
FIRE WEATHER...WASULA
HYDROLOGY...SND/WASULA








AREA FORECAST DISCUSSION

NWS TAUNTON MA

 713 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A STALLED FRONTAL BOUNDARY STRETCHING FROM NEW YORK STATE INTO NEW
ENGLAND WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES
SATURDAY AND SUNDAY. SHOWERS AND THUNDERSTORMS MAY BECOME MORE
WIDESPREAD MONDAY INTO EARLY TUESDAY AS A COLD FRONT MOVES ACROSS
THE REGION. DRIER...COOLER AND MUCH LESS HUMID WEATHER ARRIVES
MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

715 AM UPDATE...
TWO BATCHES OF SHOWERS TO MONITOR THIS MORNING. FIRST IS ACROSS
CAPE ANN WHICH IS PRODUCING SOME LIGHTNING. THE SECOND IS ACROSS
THE NW PORTION OF THE REGION WHICH IS GENERALLY JUST SHOWERS. THIS
STORMS ARE DEVELOPING ALONG THE EDGE OF THE 700MB MOISTURE REGION.
EXPECT STORM TO CONTINUE TO DEVELOP AS MU CAPE VALUES ARE ABOVE
1000 J/KG ALONG WITH COOLER TEMPS ALOFT. AS SHORTWAVE CONTINUES TO
FIZZLE OUT...THESE TEMPS ALOFT WILL WARM HOWEVER WITH BREAKS IN
THE CLOUDS EXPECT...DIURNAL HEATING WILL HELP AID IN STORM
REDEVELOP THIS AFTERNOON. MAIN BULK OF THE FORECAST REMAINS ON
TRACK...MADE MINOR ADJUSTMENTS TO ACCOUNT FOR CURRENT CONDITIONS.

PREVIOUS DISCUSSION...
SHORT WAVE TROUGH OVER THE EASTERN GREAT LAKES AND NY STATE EARLY
THIS MORNING DEAMPLIFIES AS IT APPROACHES AND MOVES ACROSS NEW
ENGLAND TODAY.  THIS IS EVIDENT IN WEAKENING WIND FIELDS
ALOFT...LESS CURVATURE IN THE MID LEVEL FLOW/STREAMLINES AND
WEAKENING Q-VECTOR CONVERGENCE ALONG AND AHEAD OF THE MID LEVEL
TROUGH. LAST FEW RUNS OF THE HRRR OFFER THE SAME THEME WITH
WEAKENING REFLECTIVITY AS CONVECTION APPROACHES NEW ENGLAND.
THEREFORE EXPECTING UPSTREAM CONVECTION ACROSS NY STATE AND VT TO
SLOWLY WEAKEN AS IT APPROACHES AND ENTERS SOUTHERN NEW ENGLAND.

HOWEVER THINK NEW CONVECTION WILL REFIRE OVER THE AREA THIS
AFTERNOON AS SOME SUNSHINE TODAY DESTABILIZES THE ATMOSPHERE WITH
THE MORE CONSERVATIVE ECMWF AND GEFS OFFERING CAPES ON THE ORDER OF
1200-1800J/KG. FAIRLY CONFIDENT IN THIS SCENARIO AS ALL MOS GUIDANCE
HAVE HIGH TEMPS TODAY IN THE LOW TO MID 80S...WITH WARMEST
READINGS ACROSS NORTHEAST MA AND SOUTHEAST NH. THIS INSTABILITY
COMBINED WITH WEAK BUT MOIST CYCLONIC FLOW ALOFT SHOULD BE
SUFFICIENT TO YIELD SCATTERED THUNDERSTORMS. HIGHEST PROBABILITY
WILL BE ACROSS THE INTERIOR...CLOSER TO FRONTAL BOUNDARY AND
SURFACE CONVERGENCE. THUS CONVECTION SHOULD BE LESS NUMEROUS ACROSS
SOUTHEAST MA /INCLUDING CAPE COD AND THE ISLANDS/ AND POSSIBLY INTO
BOSTON-PROVIDENCE CORRIDOR.  MAIN ISSUE WITH ANY TSTMS TODAY WILL BE
HEAVY DOWNPOURS/FLOOD POTENTIAL WITH PWATS JUST UNDER 2 INCHES ALONG
WITH WEAK WINDS ALOFT RESULTING IN SLOW MOVING STORMS. TIMING OF
STORMS WILL BE AFTER 16Z AND SPECIFICALLY DURING PEAK HEATING FROM
18Z-21Z.

IT WILL BE WARM AND HUMID TODAY AS SOUTHERN NEW ENGLAND WILL BE IN
THE WARM SECTOR OF THE APPROACHING FRONTAL SYSTEM. DEW PTS WILL
CLIMB INTO THE U60S AND L70S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...
EARLY EVENING SHOWERS/TSTMS ACROSS THE INTERIOR SHOULD DISSIPATE
WITHIN A FEW HOURS OF SUNSET GIVEN THE LACK OF DEEP LAYER SHEAR
AND MID LEVEL LAPSE RATES NEEDED TO SUSTAIN NOCTURNAL CONVECTION.
HOWEVER CAN/T RULE OUT ISOLATED OR WIDELY SCATTERED SHOWERS
OVERNIGHT GIVEN THE WEAK BUT MOIST CYCLONIC FLOW ALOFT.

SOUTHERN NEW ENGLAND REMAINS IN THE WARM SECTOR SO EXPECT PATCHY FOG
AND LOW CLOUDS. HIGH DEW PTS WILL YIELD ANOTHER MILD TO WARM NIGHT.

SUNDAY...
WEAK SHORT WAVE RIDGING MAY MOVE ACROSS THE REGION BEHIND
DEPARTING SHORT WAVE TROUGH OF TODAY AND BEFORE NEXT TROUGH
APPROACHES SUN NGT AND MON. THIS IS EVIDENT ON MODEL CROSS AND
TIME SECTIONS WITH COLUMN DRYING OUT IN THE MID AND UPPER LEVELS.
SO WHILE THERE IS STILL SOME UNCERTAINTY TO SUNDAY/S
FORECAST...THERE IS INCREASING CONFIDENCE THAT ANY SHOWER/TSTM
ACTIVITY WILL NOT BE WIDESPREAD. THUS NOT EXPECTING A WASHOUT
SUNDAY.

THE AREA REMAINS IN THE WARM SECTOR SO ANOTHER WARM AND MUGGY DAY
WITH HIGHS 80-85 AWAY FROM THE COAST ALONG WITH DEW PTS IN THE U60S
AND L70S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGHLIGHTS...

  * SHOWERS AND THUNDERSTORMS LIKELY ON MONDAY AND INTO TUESDAY
  * SLOW MOVING COLD FRONT WILL CROSS THE REGION ON TUESDAY
  * FALL LIKE CONDITIONS FOR THE SECOND HALF OF THE WORK WEEK

CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN OVERALL FORECAST. CONTINUE TO HAVE
INCREASING CONFIDENCE FOR THE TEMPERATURE ASPECT IN THE FORECAST.
MODERATE CONFIDENCE IN TIMING OF PRECIPITATION WITH HIGH
CONFIDENCE THAT PRECIP WILL OCCUR MONDAY AND EARLY TUESDAY. THE
00Z MODELS MAINTAIN A NEARLY STEADY-STATE TO SLIGHTLY RETROGRADING
PATTERN IN THE LOWER HALF OF THE CONUS WITH AN UPPER HIGH OVER THE
CENTRAL/SOUTHERN PLAINS. WHILE ACROSS THE NORTHEAST A PROGRESSIVE
FLOW INFLUENCED BY MULTIPLE SHORTWAVES AND FRONTAL PASSAGES WILL
RESULT IN GENERALLY COOLER TEMPERATURES. HOWEVER THE
DETAILS/TIMINGS ARE AN ISSUE DUE TO THE PATTERNS SHORT WAVELENGTH
AND POSSIBILITY OF PHASING. THAT BEING SAID FELT PERSISENT WAS A
GOOD WAY TO GO FOR THIS MORNINGS FORECAST. BLENDED PREVIOUS
FORECAST WITH WPC AND THE ENSEMBLES.

DETAILS...

MONDAY...
LONG WAVE TROUGH WILL SHARPEN UP ON MONDAY AS HUDSON BAY LOW
PRESSURE STRENGTHENS. THIS WILL KEEP THE REGION IN A SOUTHWEST
FLOW WITH INCREASING MOISTURE CAUSING VERY MUGGY CONDITIONS. MAIN
FOCUS IS A COLD FRONT ACROSS THE GREAT LAKES THAT WILL APPROACH
THE REGION. HOWEVER A SHORTWAVE WILL MOVE THROUGH THE FLOW ON
MONDAY WHICH WILL SPARK SOME SHOWERS AND THUNDERSTORMS. THE REGION
WILL BE IN THE WARM...MOIST SECTOR AS WELL AS THE BETTER JET
DYNAMICS. MAIN THREAT WITH THESE STORMS WILL BE HEAVY RAIN AS PWAT
VALUES WILL BE ABOVE 2 INCHES. THESE STORMS WILL BE SLOW MOVING
AND/OR TRAINING AS CORFIDI VECTORS ARE AROUND 0-5 KTS. NOTICED SPC
PUT THE REGION IN A SEE TEXT FOR DAY THREE OUTLOOK. HAVE LOW
CONFIDENCE IN OVERALL SEVERE WEATHER AS INSTABILITY VALUES WILL BE
LOWER THAN MODELS SUGGEST DUE TO THE AMOUNT OF CLOUDS ACROSS THE
AREA. THIS IDEA IS ALSO SUPPORTED BY THE ENSEMBLES. THEREFORE
BELIEVE THAT THE MAIN THREAT WILL STILL BE HEAVY RAIN CAUSING SOME
URBAN AND POOR DRAINAGE FLOODING. SMALL STREAMS MAY ALSO BE IN A
THREAT IF THUNDERSTORMS TRAIN OVER A CERTAIN REGION. THIS PORTION
OF THE FORECAST WILL NEED TO BE WATCHED CLOSELY OVER THE WEEKEND.

TUESDAY...
COLD FRONT WILL MOVE THROUGH SOUTHERN NEW ENGLAND ON TUESDAY.
MAIN QUESTION IS THE TIMING. IF THE FRONT SLOWS DOWN THEN THERE IS
A CHANCE FOR SHOWERS AND THUNDERSTORMS TO DEVELOP ESP ACROSS THE
EASTERN HALF OF THE REGION. IF THE FRONT SPEEDS UP THEN ONLY A FEW
SHOWERS MAY OCCUR AS THE FRONT EXITS OFFSHORE. REGARDLESS HAVE A
LOWER CONFIDENCE ON ANY STRONG STORMS ON TUESDAY AS BETTER JET
DYNAMICS WILL BE OFFSHORE. BOTH THE ENSEMBLES INDICATE THE BETTER
MOISTURE IS OFFSHORE AS WELL. TRENDED TOWARDS A FASTER SOLUTION ON
TUESDAY. A FEW HEAVY SHOWERS ARE STILL POSSIBLE WITH MAIN CONCERN
BEING NUISANCE FLOODING.

WEDNESDAY THROUGH FRIDAY...
LARGE-SCALE SUBSTANCES WILL FILTER IN BEHIND THE FRONT ON
WEDNESDAY. THIS WILL DROP DEWPOINTS DOWN INTO THE 40/50S MAKING IT
VERY COMFORTABLE. A FEW SHOWERS ARE POSSIBLE ACROSS THE NW ZONES
FROM WRAP AROUND MOISTURE FROM THE LOW. OTHERWISE EXPECT MOSTLY
DRY CONDITIONS. MODELS ARE INDICATING A POLAR FRONT WILL MOVE
THROUGH ON THURSDAY BRINGING SOME ISOLATED/SCATTERED SHOWERS. HAVE
A LOWER CONFIDENCE AS THERE IS A GOOD AMOUNT OF DRY AIR ACROSS THE
AREA. BEHIND THIS FRONT IS A MORE FALL LIKE AIRMASS BRINGING
OVERNIGHT LOWS IN THE 40S AND HIGHS ONLY IN THE 60S.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...LOW TO MODERATE CONFIDENCE ON EXACT DETAILS INCLUDING
TIMING...BUT HIGHER CONFIDENCE ON OVERALL FORECAST THEME. CIGS AND
VSBYS WERE DERIVED FROM A BLEND OF NAM AND GFS MOS.

TODAY...
IFR CIGS SHOULD BE CONFINED TO SOUTHEAST MA AND RI. THIS SHOULD
IMPROVE TO VFR 14Z-16Z. SHOWERS AND TSTMS THIS MORNING WILL SLOWLY
WEAKEN. ADDITIONAL SHOWERS AND TSTMS WILL DEVELOP AFTER 16Z
MAINLY INLAND WITH DAYTIME HEATING COMMENCING. LESS SHOWER/TSTM
ACTIVITY ACROSS SOUTHEAST MA/CAPE COD AND ISLANDS.

TONIGHT...
ALMOST A REPEAT PERFORMANCE...IFR IN LOW CLOUDS CONFINED TO
SOUTHEAST MA AND RI WITH MVFR/VFR ELSEWHERE. ISOLATED/SCATTERED
SHOWERS SHOULD BE MOST NUMEROUS WELL INLAND.

SUNDAY...
IFR SOUTHEAST MA AND RHODE ISLAND BUT IMPROVING TOWARD MIDDAY TO
VFR. VFR ELSEWHERE. NOT EXPECTING WIDESPREAD SHOWERS/TSTMS...MORE
ISOLATED TO WIDELY SCATTERED.

KBOS TERMINAL...IFR CIGS ACROSS SOUTHEAST MA MAY CLIP LOGAN 09Z-
13Z BUT BULK OF LOW CLOUDS SHOULD SLIDE SOUTH OF THE AIRPORT. MOST
SHOWER ACTIVITY SHOULD BE WEST AND NORTH OF BOSTON.

KBDL TERMINAL...SHOWERS/TSTMS WILL BECOME MORE NUMEROUS 16Z-22Z.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

SUNDAY NIGHT...MODERATE CONFIDENCE. EXPECT MAINLY MVFR CIGS/VFR
VSBYS. AREAS MVFR VSBYS IN ANY SHOWERS/TSTMS. LOCAL IFR VSBYS IN
ANY HEAVIER RAINFALL.

MONDAY-TUESDAY...LOW CONFIDENCE MAINLY FOR TIMING. MVFR
CONDITIONS WITH IFR IN SHOWERS/TSTMS. PERIODS OF HEAVY RAINFALL
WILL REDUCE VSBYS AS WELL.

WEDNESDAY...HIGH CONFIDENCE. MVFR TO START...IMPROVING TO VFR BY
THE AFTERNOON HOURS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TODAY THROUGH SUNDAY...
MODEST SW WIND 10-15 KT WITH LOW RISK OF 20 KT GUST. WARM/MUGGY
AIRMASS WILL YIELD LATE NIGHT/EARLY MORNING FOG. SHOWERS/TSTMS WILL
BE MAINLY INLAND. FORECAST CONFIDENCE MODERATE TO HIGH.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

PERSISTENT SOUTHERLY SWELL COMBINED WITH AN APPROACHING COLD
FRONT WILL CAUSE SEAS TO BUILD UP TO 5 FT ESP ACROSS THE OUTER
WATERS THROUGH TUESDAY. BELIEVE THIS IS A LITTLE HIGH SO HAVE
UNDERCUT WAVE GUIDANCE TO TOP OUT AT 4FT. LOW PROB FOR GUSTS UP TO
25 KT AHEAD OF COLD FRONT MON NIGHT AND EARLY TUE. EXPECT COLD
FRONT TO MOVE ACROSS WATERS LATE TUE/TUE NIGHT. WINDS/SEAS SHOULD
SLOWLY DIMINISH DURING WED. BEST CHANCE FOR THUNDERSTORMS WILL BE
MONDAY INTO TUESDAY MORNING.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...NOCERA/DUNTEN
SHORT TERM...NOCERA
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN




AREA FORECAST DISCUSSION

NWS ALBANY NY

 656 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM AND HUMID AIR MASS WILL IMPACT EASTERN NEW YORK
AND WESTERN NEW ENGLAND THROUGH THE HOLIDAY WEEKEND.  A SERIES OF
WEAK DISTURBANCES MOVING ALONG A FRONTAL BOUNDARY NEAR THE SAINT
LAWRENCE RIVER VALLEY WILL PRODUCE SHOWERS AND THUNDERSTORMS TODAY
WITH SOME LOCALLY HEAVY RAINFALL.  THE UNSETTLED WEATHER CONTINUES
LATE SUNDAY INTO LABOR DAY WHEN A STRONG UPPER LEVEL LOW BRINGS MORE
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS TO THE REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 655 AM EDT...THE LAST FULL DAY OF AUGUST AND METEOROLOGICAL
SUMMER BEGAN WITH SHOWERS AND SCT THUNDERSTORMS ACROSS PORTIONS OF
THE ALY FCST AREA...ESPECIALLY FROM THE NRN CATSKILLS...CAPITAL
REGION AND SRN VT NORTHWARD. A COUPLE OF WEAK SFC LOWS ARE MOVING
ALONG A STATIONARY FRONT NEAR THE ST LAWRENCE RIVER VALLEY AND ERN
GREAT LAKES THIS MORNING. LOW-LEVEL CONVERGENCE WITH THE SFC LOWS
HAS HELPED THE SHOWERS AND THUNDERSTORMS BE THE MOST PERSISTENT IN
THE MOHAWK RIVER VALLEY...SRN DACKS...AND THE LAKE GEORGE SARATOGA
REGION. THIS ACTIVITY WILL CONTINUE TO WANE EARLY THIS MORNING...AND
A BRIEF LOW WILL OCCUR TOWARDS NOONTIME. THE POPS WERE RETRENDED
THIS MORNING BASED ON THE RADAR TRENDS.

A MAJORITY OF THE GUIDANCE SHOWS ANOTHER WEAK RIPPLE OF LOW
PRESSURE MOVING ALONG THE BOUNDARY IN THE AFTERNOON WITH A MID
LEVEL SHORT-WAVE IN THE W/SW FLOW ALOFT. IT IS QUESTIONABLE IF ANY
SIGNIFICANT HEATING WILL OCCUR EXCEPT PERHAPS ALONG THE SRN TIER
OF THE FCST AREA /MID HUDSON VALLEY AND NW CT/. THE 0-6 KM DEEP
SHEAR IS WEAK WITH WEAK MID LEVEL LAPSE RATES ALOFT...SO
WIDESPREAD SEVERE CONVECTION IS NOT ANTICIPATED DESPITE SBCAPE
VALUES OF 1000-2000 J/KG ACCORDING THE NAM/GFS. H850 THETA-E
VALUES WILL BE GENERALLY IN THE 335-340K RANGE. THE PWATS WILL BE
IN THE 1.25-1.75 INCH RANGE /1 TO 2 STANDARD DEVIATIONS ABOVE
NORMAL/...SO LOCALLY HVY RAINFALL WILL BE THE MAIN ISSUE. THE
ENHANCED WORDING WAS PUT IN THE GRIDS...AND WILL BE MENTIONED IN
THE HWO. IF THE HIGHER CAPE VALUES ARE REALIZED...AN ISOLATED WET
MICROBURST MAY BE POSSIBLE. THE MAIN THREAT CONTINUES TO BE HEAVY
RAINFALL. THE HIGHEST POPS IN THE LIKELY RANGE WERE USED ACROSS
THE NRN HALF OF THE FCST AREA.

THE 07Z 3KM HRRR COLUMN REF PRODUCT SHOWS DISCRETE CONVECTIVE
ELEMENTS FORMING INTO A LINE OVER THE HUDSON RIVER VALLEY IN THE
MID AFTERNOON. IN A WEAK SHEAR ENVIRONMENT THIS APPEARS TO BE OFF
SOME...BUT WILL HAVE TO BE MONITORED. LATER RUNS HAVE SHOWN LESS
SIGNIFICANT COVERAGE AND ORGANIZATION.

THE SFC DEWPTS WILL REMAIN IN THE 60S WITH PERHAPS SOME SPOTTY
LOWER 70S OVER THE SRN TIER. THE AIR MASS WILL BE STICKY FOR THE
LAST DAY OF AUGUST. MINIMAL HEATING SHOULD ALLOW FOR U70S TO L80S
IN THE VALLEYS...WITH 70S OVER THE HILLS AND MTNS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
TONIGHT...THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN THE
EARLY EVENING WITH THE WEAK SFC WAVE MOVING EAST/NORTHEAST OF THE
REGION...AND THE MID LEVEL SHORT-WAVE PASSING DOWNSTREAM. THE
FRONTAL BOUNDARY MAY MOVE OVER THE NRN HALF OF THE FCST AREA AND
FALL APART. THE POPS WERE LOWERED TO SLIGHT CHC VALUES AFTER
MIDNIGHT. IT WILL REMAIN VERY HUMID WITH LOWS IN THE MID AND U60S
OVER MOST OF THE REGION...EXCEPT OVER THE MTNS.

SUNDAY...THE ENTIRE DAY SHOULD NOT BE A WASHOUT WITH AN AMPLIFYING
UPPER LEVEL TROUGH OVER ONTARIO AND THE GREAT LAKES REGION. THE
MID LEVEL FLOW WILL BECOME SOUTHWESTERLY OVER NY AND NEW ENGLAND
WITH WEAK RIDGING ALOFT. THEIR ARE NOT ANY REAL ROBUST SYNOPTIC
TRIGGER MECHANISMS DURING THE DAY. AIR MASS OR DIFFERENTIAL
HEATING THUNDERSTORMS ARE POSSIBLE. A SLIGHT TO LOW CHANCE OF
SHOWERS AND THUNDERSTORMS WAS INCLUDED IN THE GRIDS. H850 TEMPS
INCREASE TO +16C TO +17C WITH PARTLY SUNNY CONDITIONS. MAX TEMPS
WILL RUN ABOUT 5-10 DEGREES ABOVE NORMAL TO OPEN SEPT.

SUNDAY NIGHT INTO LABOR DAY...A LARGE TROUGH OF LOW PRESSURE
IMPACTS THE REGION. SEVERAL MID LEVEL SHORT-WAVES ROTATING AROUND
THE CLOSED LOW SOUTH OF JAMES BAY WILL YIELD UNSETTLED WX DURING
THIS TIME FRAME. IT IS DIFFICULT TO DETERMINE IF ANY ROBUST SFC
HEATING WILL OCCUR AT THIS TIME. THE STRONG SYNOPTIC LIFT WITH THE
TROUGH WILL LIKELY YIELD PERIODS OF SHOWERS AND SCT THUNDERSTORMS.
SOME HVY RAINFALL LOOKS LIKE A GOOD BET. THE QG LIFT INCREASES
LABOR DAY AFTERNOON...AS THE NRN HALF OF THE FCST AREA GETS NEAR
THE RIGHT ENTRANCE REGION OF A H250 JET STREAK WITH STRONG UPPER
LEVEL DIVERGENCE ALOFT. PWATS CONTINUE ABOVE NORMAL FOR EARLY
SEPT. LIKELY POPS WERE CONTINUED ON MONDAY. THE COOLER NAM MOS
TEMPS WERE ALSO FOLLOWED CLOSELY WITH THE AMOUNT OF CLOUD COVER
AND NUMEROUS SHOWERS EXPECTED. MAX TEMPS WILL BE HARD PRESSED TO
GET OUT OF THE 70S WITH PERHAPS SOME 80F READINGS FROM THE CAPITAL
REGION SOUTH IN THE MID HUDSON VALLEY.

MONDAY NIGHT...LOW AND MID LEVEL HEIGHTS CONTINUE TO FALL...AS THE
TROUGH OF LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MIGRATE EAST
OF THE REGION. A CHC OF SHOWERS WAS KEPT IN MOST OF THE OVERNIGHT.
LOW LEVEL COLD ADVECTION IS EXPECTED WITH TEMPS FALLING INTO THE
50S OVER THE MTNS WITH LOWER TO MID 60S IN THE VALLEYS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
COOLER AND LESS ACTIVITY WEATHER AS WE HEAD THROUGH THE FIRST WEEK
OF SEPTEMBER.

THE MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT REGARDING THE
LONGWAVE PATTERN WITH THE NORTHEAST REMAINING UNDER A TROUGH AND
THE RIDGE HOLDING ON OVER THE PLAIN STATES.

A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE REGION. THE FIRST ONE
IS EXPECTED TO MOVE OFF TO OUR EAST ON TUESDAY WITH SOME LINGERING
SHOWERS POSSIBLE MAINLY DURING THE MORNING. A PLEASANT DAY EXPECTED
WEDNESDAY AS HIGHER PRESSURE BUILDS IN WITH SEASONABLE WARM
TEMPERATURES. A SECONDARY COLD FRONT IS EXPECTED TO MOVE THROUGH
THURSDAY WITH ISOLATED SHOWERS. A MORE AUTUMN-LIKE AIRMASS WILL BE
USHERED IN AS CANADIAN HIGH PRESSURE BUILDS IN ITS WAKE OF THE FRONT
TO CLOSE OUT THE WEEK. TEMPERATURES THURSDAY AND FRIDAY ARE
ANTICIPATED TO RUN ABOUT 5 DEGREES BELOW NORMAL.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE EASTERLY ACROSS
THE FORECAST AREA EARLY THIS MORNING IN ASSOCIATION WITH AN
APPROACHING SHORT WAVE TROUGH AND WEAK SURFACE LOW MOVING INTO THE
SAINT LAWRENCE RIVER VALLEY. EXPECTING A LULL IS THE PRECIPITATION
FOR A BIT THIS MORNING MAINLY AFTER SUNRISE AS THE SHORT WAVE TROUGH
MOVES OFF TO THE EAST. HOWEVER...CHANCES FOR CONVECTION WILL
INCREASE LATER THIS MORNING AND ESPECIALLY DURING THE AFTERNOON
HOURS AS THE SURFACE LOW PASSES TO OUR NORTH AND ANOTHER SHORT WAVE
TROUGH APPROACHES. WITH THE HELP OF DAYTIME HEATING AND INCREASED
INSTABILITY THERE WILL BETTER AND WIDESPREAD CHANCES FOR
THUNDERSTORMS SO HAVE INCLUDED MENTION IN THE TAFS.

EXPECTING SOME MVFR FOG AND CIGS EARLY THIS MORNING WITH CONDITIONS
IMPROVING AFTER SUNRISE. EXPECTING MAINLY VFR CONDITIONS DURING THE
DAY WITH MVFR/BRIEF IFR CONDITIONS WITH ANY CONVECTION THAT IMPACTS
TAF SITES. MVFR FIG IS EXPECTED TO DEVELOP AGAIN THIS EVENING
ESPECIALLY WHERE IT RAINS.

OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
LABOR DAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: LOW OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY NIGHT-WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.

&&

.FIRE WEATHER...
NO FIRE WEATHER PROBLEMS ARE EXPECTED IN THE HUMID AIR MASS WITH
SEVERAL CHANCES OF RAINFALL.

A SERIES OF WEAK DISTURBANCES MOVING ALONG A FRONTAL BOUNDARY
NEAR THE SAINT LAWRENCE RIVER VALLEY WILL PRODUCE SHOWERS AND
THUNDERSTORMS TODAY WITH SOME LOCALLY HEAVY RAINFALL. THE
UNSETTLED WEATHER CONTINUES LATE SUNDAY INTO LABOR DAY WHEN A
STRONG UPPER LEVEL LOW BRINGS MORE WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS TO THE REGION.

THE RH VALUES WILL ONLY DROP TO BETWEEN 50 AND 85 PERCENT THIS
AFTERNOON...AND RECOVER TO CLOSE TO 100 PERCENT SUNDAY MORNING.
HIGH RH VALUES OF 55 TO 75 PERCENT WILL OCCUR SUNDAY AFTERNOON.

THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TODAY
AND TOMORROW... AND BECOME LIGHT TO CALM TONIGHT.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED THE NEXT 5 DAYS ON
THE MAIN STEM RIVERS. HEAVY RAINFALL WITH LOCALIZED IMPACTS WILL BE
POSSIBLE TODAY THROUGH LABOR DAY FROM SHOWERS AND THUNDERSTORMS.
THE BEST CHANCE FOR WIDESPREAD RAINFALL WILL BE TODAY AND ON
LABOR DAY.

HUMID CONDITIONS WILL PERSIST...SO LOCALIZED DOWNPOURS CAN BE
EXPECTED WITH THUNDERSTORMS. ISOLATED URBAN...SMALL STREAM...AND
POOR DRAINAGE FLOODING WILL BE POSSIBLE DURING THE HOLIDAY
WEEKEND. SOME WITHIN BANK RISES ARE POSSIBLE ON LARGER STREAMS
WHERE SHOWERS AND STORMS OCCUR. ZONAL FFG VALUES REMAIN HIGH
DURING THIS TIME FRAME. HOWEVER...A QUICK INCH OR TWO OF RAINFALL
FROM A SLOW MOVING THUNDERSTORM MAY PRODUCE AN ISOLATED FLASH
FLOOD DURING THE HOLIDAY WEEKEND.

RAINFALL AMOUNTS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE
OF THE RAIN...WITH SOME LOCATIONS RECEIVING OVER AN INCH OF RAIN
WHILE OTHERS REMAIN DRY. SOME AREAS NORTH OF THE CAPITAL REGION
HAVE RECEIVED A HALF AN INCH TO AN INCH OF RAINFALL THIS MORNING.

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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA
FIRE WEATHER...WASULA
HYDROLOGY...SND/WASULA








AREA FORECAST DISCUSSION

NWS ALBANY NY

 432 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM AND HUMID AIR MASS WILL IMPACT EASTERN NEW YORK
AND WESTERN NEW ENGLAND THROUGH THE HOLIDAY WEEKEND.  A SERIES OF
WEAK DISTURBANCES MOVING ALONG A FRONTAL BOUNDARY NEAR THE SAINT
LAWRENCE RIVER VALLEY WILL PRODUCE SHOWERS AND THUNDERSTORMS TODAY
WITH SOME LOCALLY HEAVY RAINFALL.  THE UNSETTLED WEATHER CONTINUES
LATE SUNDAY INTO LABOR DAY WHEN A STRONG UPPER LEVEL LOW BRINGS MORE
WIDESPREAD SHOWERS AND SCATTERED THUNDERSTORMS TO THE REGION.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 432 AM EDT...THE LAST FULL DAY OF METEOROLOGICAL SUMMER
BEGAN WITH SHOWERS AND SCT THUNDERSTORMS ACROSS PORTIONS OF THE
ALY FCST AREA...ESPECIALLY FROM THE NRN CATSKILLS...CAPITAL REGION
AND SRN VT NORTHWARD. A COUPLE OF WEAK SFC LOWS ARE MOVING ALONG A
STATIONARY FRONT NEAR THE ST LAWRENCE RIVER VALLEY THIS MORNING.
LOW-LEVEL CONVERGENCE WITH THE SFC LOWS HAS HELPED THE SHOWERS AND
THUNDERSTORMS BE THE MOST PERSISTENT IN THE MOHAWK RIVER
VALLEY...SRN DACKS...AND THE LAKE GEORGE SARATOGA REGION. THIS
ACTIVITY WILL CONTINUE TOWARDS SUNRISE...AND A BRIEF LOW WILL
OCCUR TOWARDS NOONTIME.

A MAJORITY OF THE GUIDANCE SHOWS ANOTHER WEAK RIPPLE OF LOW
PRESSURE MOVING ALONG THE BOUNDARY IN THE AFTERNOON WITH A MID
LEVEL SHORT-WAVE IN THE W/SW FLOW ALOFT. IT IS QUESTIONABLE IF ANY
SIGNIFICANT HEATING WILL OCCUR EXCEPT PERHAPS ALONG THE SRN TIER
OF THE FCST AREA /MID HUDSON VALLEY AND NW CT/. THE 0-6 KM DEEP
SHEAR IS WEAK WITH WEAK MID LEVEL LAPSE RATES ALOFT...SO
WIDESPREAD SEVERE CONVECTION IS NOT ANTICIPATED DESPITE SBCAPE
VALUES OF 1000-2000 J/KG ACCORDING THE NAM/GFS. H850 THETA-E
VALUES WILL BE GENERALLY IN THE 335-340K RANGE. THE PWATS WILL BE
IN THE 1.25-1.75 INCH RANGE /1 TO 2 STANDARD DEVIATIONS ABOVE
NORMAL/...SO LOCALLY HVY RAINFALL WILL BE THE MAIN ISSUE. THE
ENHANCED WORDING WAS PUT IN THE GRIDS...AND WILL BE MENTIONED IN
THE HWO. IF THE HIGHER CAPE VALUES ARE REALIZED...AN ISOLATED WET
MICROBURST MAY BE POSSIBLE. THE MAIN THREAT CONTINUES TO BE HEAVY
RAINFALL. THE HIGHEST POPS IN THE LIKELY RANGE WERE USED ACROSS
THE NRN HALF OF THE FCST AREA.

THE LATEST 3KM HRRR COLUMN REF PRODUCT SHOWS DISCRETE CONVECTIVE
ELEMENTS FORMING INTO A LINE OVER THE HUDSON RIVER VALLEY IN THE
MID AFTERNOON. IN A WEAK SHEAR ENVIRONMENT THIS APPEARS TO BE OFF
SOME...BUT WILL HAVE TO BE MONITORED.

THE SFC DEWPTS WILL REMAIN IN THE 60S WITH PERHAPS SOME SPOTTY
LOWER 70S OVER THE SRN TIER. THE AIR MASS WILL BE STICKY FOR THE
LAST DAY OF AUGUST. MINIMAL HEATING SHOULD ALLOW FOR U70S TO L80S
IN THE VALLEYS...WITH 70S OVER THE HILLS AND MTNS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
TONIGHT...THE SHOWERS AND THUNDERSTORMS SHOULD DIMINISH IN THE
EARLY EVENING WITH THE WEAK SFC WAVE MOVING EAST/NORTHEAST OF THE
REGION...AND THE MID LEVEL SHORT-WAVE PASSING DOWNSTREAM. THE
FRONTAL BOUNDARY MAY MOVE OVER THE NRN HALF OF THE FCST AREA AND
FALL APART. THE POPS WERE LOWERED TO SLIGHT CHC VALUES AFTER
MIDNIGHT. IT WILL REMAIN VERY HUMID WITH LOWS IN THE MID AND U60S
OVER MOST OF THE REGION...EXCEPT OVER THE MTNS.

SUNDAY...THE ENTIRE DAY SHOULD NOT BE A WASHOUT WITH AN AMPLIFYING
UPPER LEVEL TROUGH OVER ONTARIO AND THE GREAT LAKES REGION. THE
MID LEVEL FLOW WILL BECOME SOUTHWESTERLY OVER NY AND NEW ENGLAND
WITH WEAK RIDGING ALOFT. THEIR ARE NOT ANY REAL ROBUST SYNOPTIC
TRIGGER MECHANISMS DURING THE DAY. AIR MASS OR DIFFERENTIAL
HEATING THUNDERSTORMS ARE POSSIBLE. A SLIGHT TO LOW CHANCE OF
SHOWERS AND THUNDERSTORMS WAS INCLUDED IN THE GRIDS. H850 TEMPS
INCREASE TO +16C TO +17C WITH PARTLY SUNNY CONDITIONS. MAX TEMPS
WILL RUN ABOUT 5-10 DEGREES ABOVE NORMAL TO OPEN SEPT.

SUNDAY NIGHT INTO LABOR DAY...A LARGE TROUGH OF LOW PRESSURE
IMPACTS THE REGION. SEVERAL MID LEVEL SHORT-WAVES ROTATING AROUND
THE CLOSED LOW SOUTH OF JAMES BAY WILL YIELD UNSETTLED WX DURING
THIS TIME FRAME. IT IS DIFFICULT TO DETERMINE IF ANY ROBUST SFC
HEATING WILL OCCUR AT THIS TIME. THE STRONG SYNOPTIC LIFT WITH THE
TROUGH WILL LIKELY YIELD PERIODS OF SHOWERS AND SCT THUNDERSTORMS.
SOME HVY RAINFALL LOOKS LIKE A GOOD BET. THE QG LIFT INCREASES
LABOR DAY AFTERNOON...AS THE NRN HALF OF THE FCST AREA GETS NEAR
THE RIGHT ENTRANCE REGION OF A H250 JET STREAK WITH STRONG UPPER
LEVEL DIVERGENCE ALOFT. PWATS CONTINUE ABOVE NORMAL FOR EARLY
SEPT. LIKELY POPS WERE CONTINUED ON MONDAY. THE COOLER NAM MOS
TEMPS WERE ALSO FOLLOWED CLOSELY WITH THE AMOUNT OF CLOUD COVER
AND NUMEROUS SHOWERS EXPECTED. MAX TEMPS WILL BE HARD PRESSED TO
GET OUT OF THE 70S WITH PERHAPS SOME 80F READINGS FROM THE CAPITAL
REGION SOUTH IN THE MID HUDSON VALLEY.

MONDAY NIGHT...LOW AND MID LEVEL HEIGHT CONTINUE TO FALL...AS THE
TROUGH OF LOW PRESSURE AND ITS ASSOCIATED COLD FRONT MIGRATE EAST
OF THE REGION. A CHC OF SHOWERS WAS KEPT IN MOST OF THE OVERNIGHT.
LOW LEVEL COLD ADVECTION IS EXPECTED WITH TEMPS FALLING INTO THE
50S OVER THE MTNS WITH LOWER TO MID 60S IN THE VALLEYS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
COOLER AND LESS ACTIVITY WEATHER AS WE HEAD THROUGH THE FIRST WEEK
OF SEPTEMBER.

THE MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT REGARDING THE
LONGWAVE PATTERN WITH THE NORTHEAST REMAINING UNDER A TROUGH AND
THE RIDGE HOLDING ON OVER THE PLAIN STATES.

A COUPLE OF COLD FRONTS WILL MOVE ACROSS THE REGION. THE FIRST ONE
IS EXPECTED TO MOVE OFF TO OUR EAST ON TUESDAY WITH SOME LINGERING
SHOWERS POSSIBLE MAINLY DURING THE MORNING. A PLEASANT DAY EXPECTED
WEDNESDAY AS HIGHER PRESSURE BUILDS IN WITH SEASONABLE WARM
TEMPERATURES. A SECONDARY COLD FRONT IS EXPECTED TO MOVE THROUGH
THURSDAY WITH ISOLATED SHOWERS. A MORE AUTUMN-LIKE AIRMASS WILL BE
USHERED IN AS CANADIAN HIGH PRESSURE BUILDS IN ITS WAKE OF THE FRONT
TO CLOSE OUT THE WEEK. TEMPERATURES THURSDAY AND FRIDAY ARE
ANTICIPATED TO RUN ABOUT 5 DEGREES BELOW NORMAL.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE TO MOVE EASTERLY ACROSS
THE FORECAST AREA EARLY THIS MORNING IN ASSOCIATION WITH AN
APPROACHING SHORT WAVE TROUGH AND WEAK SURFACE LOW MOVING INTO THE
SAINT LAWRENCE RIVER VALLEY. EXPECTING A LULL IS THE PRECIPITATION
FOR A BIT THIS MORNING MAINLY AFTER SUNRISE AS THE SHORT WAVE TROUGH
MOVES OFF TO THE EAST. HOWEVER...CHANCES FOR CONVECTION WILL
INCREASE LATER THIS MORNING AND ESPECIALLY DURING THE AFTERNOON
HOURS AS THE SURFACE LOW PASSES TO OUR NORTH AND ANOTHER SHORT WAVE
TROUGH APPROACHES. WITH THE HELP OF DAYTIME HEATING AND INCREASED
INSTABILITY THERE WILL BETTER AND WIDESPREAD CHANCES FOR
THUNDERSTORMS SO HAVE INCLUDED MENTION IN THE TAFS.

EXPECTING SOME MVFR FOG AND CIGS EARLY THIS MORNING WITH CONDITIONS
IMPROVING AFTER SUNRISE. EXPECTING MAINLY VFR CONDITIONS DURING THE
DAY WITH MVFR/BRIEF IFR CONDITIONS WITH ANY CONVECTION THAT IMPACTS
TAF SITES. MVFR FIG IS EXPECTED TO DEVELOP AGAIN THIS EVENING
ESPECIALLY WHERE IT RAINS.

OUTLOOK...
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
LABOR DAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: LOW OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY NIGHT-WEDNESDAY: NO OPERATIONAL IMPACT.  NO SIG WX.

&&

.FIRE WEATHER...
NO FIRE WEATHER PROBLEMS ARE EXPECTED IN THE HUMID AIR MASS WITH
SEVERAL CHANCES OF RAINFALL.

A SERIES OF WEAK DISTURBANCES MOVING ALONG A FRONTAL BOUNDARY
NEAR THE SAINT LAWRENCE RIVER VALLEY WILL PRODUCE SHOWERS AND
THUNDERSTORMS TODAY WITH SOME LOCALLY HEAVY RAINFALL. THE
UNSETTLED WEATHER CONTINUES LATE SUNDAY INTO LABOR DAY WHEN A
STRONG UPPER LEVEL LOW BRINGS MORE WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS TO THE REGION.

THE RH VALUES WILL ONLY DROP TO BETWEEN 50 AND 85 PERCENT THIS
AFTERNOON...AND RECOVER TO CLOSE TO 100 PERCENT SUNDAY MORNING.
HIGH RH VALUES OF 55 TO 75 PERCENT WILL OCCUR SUNDAY AFTERNOON.

THE WINDS WILL BE FROM THE SOUTH TO SOUTHWEST AT 5 TO 15 MPH TODAY
AND TOMORROW... AND BECOME LIGHT TO CALM TONIGHT.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED THE NEXT 5 DAYS ON
THE MAIN STEM RIVERS. HEAVY RAINFALL WITH LOCALIZED IMPACTS WILL BE
POSSIBLE TODAY THROUGH LABOR DAY FROM SHOWERS AND THUNDERSTORMS.
THE BEST CHANCE FOR WIDESPREAD RAINFALL WILL BE TODAY AND ON
LABOR DAY.

HUMID CONDITIONS WILL PERSIST...SO LOCALIZED DOWNPOURS CAN BE
EXPECTED WITH THUNDERSTORMS. ISOLATED URBAN...SMALL STREAM...AND
POOR DRAINAGE FLOODING WILL BE POSSIBLE DURING THE HOLIDAY
WEEKEND. SOME WITHIN BANK RISES ARE POSSIBLE ON LARGER STREAMS
WHERE SHOWERS AND STORMS OCCUR. ZONAL FFG VALUES REMAIN HIGH
DURING THIS TIME FRAME. HOWEVER...A QUICK INCH OR TWO OF RAINFALL
FROM A SLOW MOVING THUNDERSTORM MAY PRODUCE AN ISOLATED FLASH
FLOOD DURING THE HOLIDAY WEEKEND.

RAINFALL AMOUNTS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE
OF THE RAIN...WITH SOME LOCATIONS RECEIVING OVER AN INCH OF RAIN
WHILE OTHERS REMAIN DRY. SOME AREAS NORTH OF THE CAPITAL REGION
HAVE RECEIVED A HALF AN INCH TO AN INCH OF RAINFALL THIS MORNING.

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...WASULA
NEAR TERM...WASULA
SHORT TERM...WASULA
LONG TERM...IAA
AVIATION...IAA
FIRE WEATHER...WASULA
HYDROLOGY...SND/WASULA








AREA FORECAST DISCUSSION

NWS TAUNTON MA

 414 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A STALLED FRONTAL BOUNDARY STRETCHING FROM NEW YORK STATE INTO NEW
ENGLAND WILL RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS AT TIMES
SATURDAY AND SUNDAY. SHOWERS AND THUNDERSTORMS MAY BECOME MORE
WIDESPREAD MONDAY INTO EARLY TUESDAY AS A COLD FRONT MOVES ACROSS
THE REGION. DRIER...COOLER AND MUCH LESS HUMID WEATHER ARRIVES
MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...

SHORT WAVE TROUGH OVER THE EASTERN GREAT LAKES AND NY STATE EARLY
THIS MORNING DEAMPLIFIES AS IT APPROACHES AND MOVES ACROSS NEW
ENGLAND TODAY.  THIS IS EVIDENT IN WEAKENING WIND FIELDS
ALOFT...LESS CURVATURE IN THE MID LEVEL FLOW/STREAMLINES AND
WEAKENING Q-VECTOR CONVERGENCE ALONG AND AHEAD OF THE MID LEVEL
TROUGH. LAST FEW RUNS OF THE HRRR OFFER THE SAME THEME WITH
WEAKENING REFLECTIVITY AS CONVECTION APPROACHES NEW ENGLAND.
THEREFORE EXPECTING UPSTREAM CONVECTION ACROSS NY STATE AND VT TO
SLOWLY WEAKEN AS IT APPROACHES AND ENTERS SOUTHERN NEW ENGLAND.

HOWEVER THINK NEW CONVECTION WILL REFIRE OVER THE AREA THIS
AFTERNOON AS SOME SUNSHINE TODAY DESTABILIZES THE ATMOSPHERE WITH
THE MORE CONSERVATIVE ECMWF AND GEFS OFFERING CAPES ON THE ORDER OF
1200-1800J/KG. FAIRLY CONFIDENT IN THIS SCENARIO AS ALL MOS GUIDANCE
HAVE HIGH TEMPS TODAY IN THE LOW TO MID 80S...WITH WARMEST
READINGS ACROSS NORTHEAST MA AND SOUTHEAST NH. THIS INSTABILITY
COMBINED WITH WEAK BUT MOIST CYCLONIC FLOW ALOFT SHOULD BE
SUFFICIENT TO YIELD SCATTERED THUNDERSTORMS. HIGHEST PROBABILITY
WILL BE ACROSS THE INTERIOR...CLOSER TO FRONTAL BOUNDARY AND
SURFACE CONVERGENCE. THUS CONVECTION SHOULD BE LESS NUMEROUS ACROSS
SOUTHEAST MA /INCLUDING CAPE COD AND THE ISLANDS/ AND POSSIBLY INTO
BOSTON-PROVIDENCE CORRIDOR.  MAIN ISSUE WITH ANY TSTMS TODAY WILL BE
HEAVY DOWNPOURS/FLOOD POTENTIAL WITH PWATS JUST UNDER 2 INCHES ALONG
WITH WEAK WINDS ALOFT RESULTING IN SLOW MOVING STORMS. TIMING OF
STORMS WILL BE AFTER 16Z AND SPECIFICALLY DURING PEAK HEATING FROM
18Z-21Z.

IT WILL BE WARM AND HUMID TODAY AS SOUTHERN NEW ENGLAND WILL BE IN
THE WARM SECTOR OF THE APPROACHING FRONTAL SYSTEM. DEW PTS WILL
CLIMB INTO THE U60S AND L70S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...

TONIGHT...
EARLY EVENING SHOWERS/TSTMS ACROSS THE INTERIOR SHOULD DISSIPATE
WITHIN A FEW HOURS OF SUNSET GIVEN THE LACK OF DEEP LAYER SHEAR
AND MID LEVEL LAPSE RATES NEEDED TO SUSTAIN NOCTURNAL CONVECTION.
HOWEVER CAN/T RULE OUT ISOLATED OR WIDELY SCATTERED SHOWERS
OVERNIGHT GIVEN THE WEAK BUT MOIST CYCLONIC FLOW ALOFT.

SOUTHERN NEW ENGLAND REMAINS IN THE WARM SECTOR SO EXPECT PATCHY FOG
AND LOW CLOUDS. HIGH DEW PTS WILL YIELD ANOTHER MILD TO WARM NIGHT.

SUNDAY...
WEAK SHORT WAVE RIDGING MAY MOVE ACROSS THE REGION BEHIND
DEPARTING SHORT WAVE TROUGH OF TODAY AND BEFORE NEXT TROUGH
APPROACHES SUN NGT AND MON. THIS IS EVIDENT ON MODEL CROSS AND
TIME SECTIONS WITH COLUMN DRYING OUT IN THE MID AND UPPER LEVELS.
SO WHILE THERE IS STILL SOME UNCERTAINTY TO SUNDAY/S
FORECAST...THERE IS INCREASING CONFIDENCE THAT ANY SHOWER/TSTM
ACTIVITY WILL NOT BE WIDESPREAD. THUS NOT EXPECTING A WASHOUT
SUNDAY.

THE AREA REMAINS IN THE WARM SECTOR SO ANOTHER WARM AND MUGGY DAY
WITH HIGHS 80-85 AWAY FROM THE COAST ALONG WITH DEW PTS IN THE U60S
AND L70S.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...

HIGHLIGHTS...

  * SHOWERS AND THUNDERSTORMS LIKELY ON MONDAY AND INTO TUESDAY
  * SLOW MOVING COLD FRONT WILL CROSS THE REGION ON TUESDAY
  * FALL LIKE CONDITIONS FOR THE SECOND HALF OF THE WORK WEEK

CONFIDENCE LEVEL/MODEL GUIDANCE...
MODERATE CONFIDENCE IN OVERALL FORECAST. CONTINUE TO HAVE
INCREASING CONFIDENCE FOR THE TEMPERATURE ASPECT IN THE FORECAST.
MODERATE CONFIDENCE IN TIMING OF PRECIPITATION WITH HIGH
CONFIDENCE THAT PRECIP WILL OCCUR MONDAY AND EARLY TUESDAY. THE
00Z MODELS MAINTAIN A NEARLY STEADY-STATE TO SLIGHTLY RETROGRADING
PATTERN IN THE LOWER HALF OF THE CONUS WITH AN UPPER HIGH OVER THE
CENTRAL/SOUTHERN PLAINS. WHILE ACROSS THE NORTHEAST A PROGRESSIVE
FLOW INFLUENCED BY MULTIPLE SHORTWAVES AND FRONTAL PASSAGES WILL
RESULT IN GENERALLY COOLER TEMPERATURES. HOWEVER THE
DETAILS/TIMINGS ARE AN ISSUE DUE TO THE PATTERNS SHORT WAVELENGTH
AND POSSIBILITY OF PHASING. THAT BEING SAID FELT PERSISENT WAS A
GOOD WAY TO GO FOR THIS MORNINGS FORECAST. BLENDED PREVIOUS
FORECAST WITH WPC AND THE ENSEMBLES.

DETAILS...

MONDAY...
LONG WAVE TROUGH WILL SHARPEN UP ON MONDAY AS HUDSON BAY LOW
PRESSURE STRENGTHENS. THIS WILL KEEP THE REGION IN A SOUTHWEST
FLOW WITH INCREASING MOISTURE CAUSING VERY MUGGY CONDITIONS. MAIN
FOCUS IS A COLD FRONT ACROSS THE GREAT LAKES THAT WILL APPROACH
THE REGION. HOWEVER A SHORTWAVE WILL MOVE THROUGH THE FLOW ON
MONDAY WHICH WILL SPARK SOME SHOWERS AND THUNDERSTORMS. THE REGION
WILL BE IN THE WARM...MOIST SECTOR AS WELL AS THE BETTER JET
DYNAMICS. MAIN THREAT WITH THESE STORMS WILL BE HEAVY RAIN AS PWAT
VALUES WILL BE ABOVE 2 INCHES. THESE STORMS WILL BE SLOW MOVING
AND/OR TRAINING AS CORFIDI VECTORS ARE AROUND 0-5 KTS. NOTICED SPC
PUT THE REGION IN A SEE TEXT FOR DAY THREE OUTLOOK. HAVE LOW
CONFIDENCE IN OVERALL SEVERE WEATHER AS INSTABILITY VALUES WILL BE
LOWER THAN MODELS SUGGEST DUE TO THE AMOUNT OF CLOUDS ACROSS THE
AREA. THIS IDEA IS ALSO SUPPORTED BY THE ENSEMBLES. THEREFORE
BELIEVE THAT THE MAIN THREAT WILL STILL BE HEAVY RAIN CAUSING SOME
URBAN AND POOR DRAINAGE FLOODING. SMALL STREAMS MAY ALSO BE IN A
THREAT IF THUNDERSTORMS TRAIN OVER A CERTAIN REGION. THIS PORTION
OF THE FORECAST WILL NEED TO BE WATCHED CLOSELY OVER THE WEEKEND.

TUESDAY...
COLD FRONT WILL MOVE THROUGH SOUTHERN NEW ENGLAND ON TUESDAY.
MAIN QUESTION IS THE TIMING. IF THE FRONT SLOWS DOWN THEN THERE IS
A CHANCE FOR SHOWERS AND THUNDERSTORMS TO DEVELOP ESP ACROSS THE
EASTERN HALF OF THE REGION. IF THE FRONT SPEEDS UP THEN ONLY A FEW
SHOWERS MAY OCCUR AS THE FRONT EXITS OFFSHORE. REGARDLESS HAVE A
LOWER CONFIDENCE ON ANY STRONG STORMS ON TUESDAY AS BETTER JET
DYNAMICS WILL BE OFFSHORE. BOTH THE ENSEMBLES INDICATE THE BETTER
MOISTURE IS OFFSHORE AS WELL. TRENDED TOWARDS A FASTER SOLUTION ON
TUESDAY. A FEW HEAVY SHOWERS ARE STILL POSSIBLE WITH MAIN CONCERN
BEING NUISANCE FLOODING.

WEDNESDAY THROUGH FRIDAY...
LARGE-SCALE SUBSTANCES WILL FILTER IN BEHIND THE FRONT ON
WEDNESDAY. THIS WILL DROP DEWPOINTS DOWN INTO THE 40/50S MAKING IT
VERY COMFORTABLE. A FEW SHOWERS ARE POSSIBLE ACROSS THE NW ZONES
FROM WRAP AROUND MOISTURE FROM THE LOW. OTHERWISE EXPECT MOSTLY
DRY CONDITIONS. MODELS ARE INDICATING A POLAR FRONT WILL MOVE
THROUGH ON THURSDAY BRINGING SOME ISOLATED/SCATTERED SHOWERS. HAVE
A LOWER CONFIDENCE AS THERE IS A GOOD AMOUNT OF DRY AIR ACROSS THE
AREA. BEHIND THIS FRONT IS A MORE FALL LIKE AIRMASS BRINGING
OVERNIGHT LOWS IN THE 40S AND HIGHS ONLY IN THE 60S.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

OVERVIEW...LOW TO MODERATE CONFIDENCE ON EXACT DETAILS INCLUDING
TIMING...BUT HIGHER CONFIDENCE ON OVERALL FORECAST THEME. CIGS AND
VSBYS WERE DERIVED FROM A BLEND OF NAM AND GFS MOS.

TODAY...
IFR CIGS SHOULD BE CONFINED TO SOUTHEAST MA AND RI. THIS SHOULD
IMPROVE TO VFR 14Z-16Z. SHOWERS AND TSTMS ENTERING WESTERN NEW
ENGLAND AT 2 AM IS EXPECTED TO WEAKEN AS IT TRAVERSES EASTWARD.
ADDITIONAL SHOWERS AND TSTMS WILL DEVELOP AFTER 16Z MAINLY INLAND
WITH DAYTIME HEATING COMMENCING. LESS SHOWER/TSTM ACTIVITY ACROSS
SOUTHEAST MA/CAPE COD AND ISLANDS.

TONIGHT...
ALMOST A REPEAT PERFORMANCE...IFR IN LOW CLOUDS CONFINED TO
SOUTHEAST MA AND RI WITH MVFR/VFR ELSEWHERE. ISOLATED/SCATTERED
SHOWERS SHOULD BE MOST NUMEROUS WELL INLAND.

SUNDAY...
IFR SOUTHEAST MA AND RHODE ISLAND BUT IMPROVING TOWARD MIDDAY TO
VFR. VFR ELSEWHERE. NOT EXPECTING WIDESPREAD SHOWERS/TSTMS...MORE
ISOLATED TO WIDELY SCATTERED.

KBOS TERMINAL...IFR CIGS ACROSS SOUTHEAST MA MAY CLIP LOGAN 09Z-
13Z BUT BULK OF LOW CLOUDS SHOULD SLIDE SOUTH OF THE AIRPORT. MOST
SHOWER ACTIVITY SHOULD BE WEST AND NORTH OF BOSTON.

KBDL TERMINAL...SHOWERS/TSTMS WILL BECOME MORE NUMEROUS 16Z-22Z.

OUTLOOK...SUNDAY NIGHT THROUGH WEDNESDAY...

SUNDAY NIGHT...MODERATE CONFIDENCE. EXPECT MAINLY MVFR CIGS/VFR
VSBYS. AREAS MVFR VSBYS IN ANY SHOWERS/TSTMS. LOCAL IFR VSBYS IN
ANY HEAVIER RAINFALL.

MONDAY-TUESDAY...LOW CONFIDENCE MAINLY FOR TIMING. MVFR
CONDITIONS WITH IFR IN SHOWERS/TSTMS. PERIODS OF HEAVY RAINFALL
WILL REDUCE VSBYS AS WELL.

WEDNESDAY...HIGH CONFIDENCE. MVFR TO START...IMPROVING TO VFR BY
THE AFTERNOON HOURS.

&&

.MARINE...
FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

TODAY THROUGH SUNDAY...
MODEST SW WIND 10-15 KT WITH LOW RISK OF 20 KT GUST. WARM/MUGGY
AIRMASS WILL YIELD LATE NIGHT/EARLY MORNING FOG. SHOWERS/TSTMS WILL
BE MAINLY INLAND. FORECAST CONFIDENCE MODERATE TO HIGH.

OUTLOOK...MONDAY THROUGH WEDNESDAY...

PERSISTENT SOUTHERLY SWELL COMBINED WITH AN APPROACHING COLD
FRONT WILL CAUSE SEAS TO BUILD UP TO 5 FT ESP ACROSS THE OUTER
WATERS THROUGH TUESDAY. BELIEVE THIS IS A LITTLE HIGH SO HAVE
UNDERCUT WAVE GUIDANCE TO TOP OUT AT 4FT. LOW PROB FOR GUSTS UP TO
25 KT AHEAD OF COLD FRONT MON NIGHT AND EARLY TUE. EXPECT COLD
FRONT TO MOVE ACROSS WATERS LATE TUE/TUE NIGHT. WINDS/SEAS SHOULD
SLOWLY DIMINISH DURING WED. BEST CHANCE FOR THUNDERSTORMS WILL BE
MONDAY INTO TUESDAY MORNING.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...NOCERA/DUNTEN
NEAR TERM...NOCERA
SHORT TERM...NOCERA
LONG TERM...DUNTEN
AVIATION...NOCERA/DUNTEN
MARINE...NOCERA/DUNTEN




AREA FORECAST DISCUSSION

NWS ALBANY NY

 152 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A SOUTHWEST FLOW OF WARM AND HUMID AIR...WILL COMBINE
WITH A WEAK LOW PRESSURE SYSTEM SLOWLY TRACKING EASTWARD THROUGH THE
SAINT LAWRENCE VALLEY TO PRODUCE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS THIS MORNING THROUGH SUNDAY. A MUCH STRONGER SYSTEM
WILL BRING A THREAT FOR MORE NUMEROUS SHOWERS AND THUNDERSTORMS ON
LABOR DAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 137 AM EDT...THE NRN HALF OF THE FCST AREA CONTINUES TO HAVE
SCT-NUMEROUS SHOWERS AND SOME THUNDERSTORMS AHEAD OF A MID-LEVEL
SHORT-WAVE AND A SFC TROUGH ASSOCIATED WITH RIPPLES OF LOW PRESSURE
MOVING ALONG THE ST LAWRENCE RIVER VALLEY. A FEW STRONGER
THUNDERSTORMS HAVE MOVED ACROSS THE SARATOGA REGION WITH FQT LTG
BRIEF BURSTS OF HVY RAIN...AND POSSIBLY SOME SMALL HAIL.

THE LATEST RUC HAS SHOWALTER VALUES OF 0 TO -2C. THE ELEVATED
INSTABILITY WILL LINGER WITH A SLIGHT TO LOW CHC OF THUNDERSTORMS
THIS MORNING...ESPECIALLY NEAR THE LOW-LEVEL CONVERGENT BOUNDARY.
THERE IS LESS LTG UPSTREAM AND SOME OF THE SHOWERS ARE STARTING
MOVE SOUTH OF THE MOHAWK VALLEY. SLIGHT OR LOW CHC POPS WERE USED
HERE...BUT SOME LOCATIONS MAY REMAIN DRY SOUTH AND EAST OF THE
CAPITAL REGION.

MUGGY CONDITIONS WILL CONTINUE WILL DEWPTS IN THE 60S. OVERNIGHT
LOWS WILL BE ABOVE NORMAL IN THE 60S ACROSS THE FCST AREA.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
FOR SATURDAY...WEAK LOW PRESSURE AT THE SURFACE AND
ALOFT WILL REMAIN OVER AND NORTH OF THE AREA. WITH WARM AND HUMID
AIRMASS IN PLACE...ONLY A WEAK TRIGGER NEEDED TO START SHOWERS AND
STORMS. MODELS DON`T INDICATE ANY PARTICULAR FORCING FOR THE
SHOWERS/STORMS SO PARTLY SUNNY CONDITIONS WITH A CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS LOOKS GOOD. FOR
SUNDAY...STRONG IMPULSE HAS REACHED THE WESTERN GREAT LAKES. THIS
WORKS TO INDUCE WEAK RIDGING ACROSS THE ALBANY FORECAST AREA.
THIS WEAK RIDGING/HIGH PRESSURE SHOULD KEEP GENERALLY FAIR WEATHER
OVER THE AREA WITH AGAIN A CHANCE FOR SHOWERS AND THUNDERSTORMS...
MAINLY SUNDAY AFTERNOON. BY LATE SUNDAY NIGHT...AN UPPER LEVEL
TROUGH...ASSOCIATED WITH DEEP GREAT LAKES LOW MAY BRING AN
INCREASED THREAT OF SHOWERS AND STORMS.

MAX/MIN TEMPERATURES GENERALLY A MOS BLEND. AREAS OF FOG EXPECTED
EACH MORNING WITH STEAMY AIRMASS IN PLACE.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
THE LONG TERM PERIOD WILL COINCIDE WITH THE BEGINNING OF
METEOROLOGICAL FALL (WHICH STARTS RIGHT ON LABOR DAY). THIS
YEAR...ALMOST ON QUE...OUR WEATHER WILL BECOME MUCH MORE AUTUMNAL
FEELING. HAVE LEANED HEAVILY WITH THE 12Z EUROPEAN MODEL...WHICH IS
FAIRLY CLOSE TO THE HPC GUIDANCE.

ON LABOR DAY ITSELF...WE WILL REMAIN IN A FAIRLY HUMID AND WARM AIR
MASS. A PRE-FRONTAL TROUGH LOOKS TO BE THE INITIAL TRIGGER EARLY ON
LABOR DAY. THE ACTUAL COLD FRONT...A FAIRLY STRONG ONE AT
THAT...WILL MOVE THROUGH OUR REGION LATE IN THE DAY OR MONDAY NIGHT
WITH THE POSSIBILITY OF ADDITIONAL SHOWERS OR THUNDERSTORMS. AT THIS
POINT IT IS VERY HARD TO NAIL DOWN THE EXACT TIMING OF THE
SYSTEMS...OR WHICH ONE WOULD BRING THE BULK OF CONVECTIVE ACTIVITY.

BY TUESDAY...THE 12Z EUROPEAN HAS THE COLD FRONT TO OUR EAST. THERE
IS STILL THE UPPER AIR TROUGH THAT NEEDS TO COME THROUGH TO OUR
NORTH...BUT THERE WILL BE LOT LESS AVAILABLE MOISTURE. THEREFORE WE
DROP POPS TO SLIGHT CHANCES (24 PERCENT BY TUESDAY).
MEANWHILE...H850 TEMPERATURES ARE FORECAST TO COOL FROM ABOUT +16C
TO +17C ON MONDAY...DOWN TO AROUND +9C BY LATE TUESDAY VIA A GUSTY
NORTHWEST BREEZE.

HIGH PRESSURE BUILDS INTO THE REGION BY WEDNESDAY. HOWEVER...IT WILL
BE DISPLACED TO THE SOUTH AND EAST AS YET ANOTHER COOLER COLD FRONT
MOVES THROUGH ON THURSDAY. THIS ONE SHOULD HAVE VERY LITTLE MOISTURE
TO WORK WITH AND SO WE ONLY ASSIGNED SLIGHT POPS FOR THURSDAY.

BEHIND THE SECOND COLD FRONT COMES THE COOLEST AIRMASS SINCE LAST
MAY! EVEN THOUGH FORECAST H850 TEMPS WERE NOT AS COOL ON THIS RUN
COMPARED TO PREVIOUS ONES...TE EUROPEAN MODEL STILL INDICATED THEY
WOULD BE COOLING DOWN TO A RANGE BETWEEN +2C IN OUR NORTHERN
ZONES...TO ABOUT +5C IN OUR SOUTHERN ZONES BY FRIDAY.


TEMPERATURES ON LABOR DAY LOOK TO MAX OUT BETWEEN THE UPPER 70S
ACROSS THE MOUNTAINS...TO 80-85 ACROSS THE MAJORITY OF OUR COUNTY
WARNING AREA. THIS ASSUMES PLENTY OF CLOUD COVER. IF WE WERE TO
RECEIVE MORE BREAKS OF SUNSHINE IT COULD BE A LITTLE WARMER THAN
WHAT WE ARE FORECASTING ALONG WITH AN INCREASED RISK OF STRONGER
THUNDERSTORMS. EITHER WAY...IT WILL BE HUMID.

LOWS MONDAY NIGHT WILL RANGE BETWEEN THE UPPER 50S TO MID 60S.
TUESDAY WILL SEE HIGHS NEAR 80 AROUND POUGHKEEPSIE...MAINLY IN THE
70S ELSEWHERE...EXCEPT UPPER 60S OVER THE HIGHEST MOUNTAIN AREAS. A
BREEZE ON TUESDAY NIGHT MIGHT KEEP TEMPERATURES FROM FALLING MORE
THAN THEY WOULD HAVE OTHERWISE. A LITTLE COOLER TUESDAY NIGHT WITH
LOWS RANGING FROM THE MID 40S TO MID 50S.

WEDNESDAY MIGHT BE THE PICK OF THE WEAK...WITH LOW HUMIDITY...LOTS
OF SUNSHINE AND TEMPERATURES IN THE 70S. WEDNESDAY NIGHT LOWS WILL
BE SIMILAR TO TUESDAY...45 TO 55.

THURSDAY...AS THE H850 TEMPERATURES DIP INTO THE SINGLE
NUMBERS...THERE COULD BE A LOT OF CLOUD COVER AROUND AND THOSE
ISOLATED SHOWERS. HIGH TEMPERATURES THAT DAY MIGHT NOT GET OUT OF
THE 60S FROM ALBANY NORTHWARD...EVEN UPPER 50S ACROSS MUCH OF THE
ADIRONDACK PARK. EVEN FURTHER SOUTH...ONLY LOWER 70S FOR A HIGH
ACROSS THE MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY.

ENOUGH COLD AIR ADVECTION CLOUDS AND A GRADIENT WOULD BE ONLY THING
PREVENTING TEMPERATURES FROM REACHING FROSTY LEVELS IN OUR
ADIRONDACKS BY THURSDAY NIGHT. WE EXPECT BOTH THE CLOUDS AND A BIT
BREEZE TO HOLD TEMPERATURES UP A LITTLE...AS THEY WILL RANGE FROM
THE LOWER 40S NORTHWEST TO THE LOWER 50S NORTHWEST BY FRIDAY
MORNING.

TEMPERATURES ONCE AGAIN LOOK TO BE HELD MAINLY TO THE 60S ON FRIDAY
DESPITE A GOOD DEAL OF SUNSHINE.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A BATCH OF SHOWERS AND SOME THUNDERSTORMS CONTINUE TO MOVE EASTERLY
ACROSS THE NORTHERN PORTION OF THE FORECAST AREA...MAINLY NORTH
I-90...IN ASSOCIATION WITH AN APPROACHING SHORT WAVE TROUGH AND
WEAK SURFACE LOW MOVING INTO THE SAINT LAWRENCE RIVER VALLEY. KGFL
HAS BEEN DIRECTLY IMPACTED BY THE CONVECTION WHILE STORMS HAVE
PASSED JUST TO THE NORTH OF KALB. THE THREAT OF SHOWERS AND
POSSIBLY THUNDERSTORMS WILL CONTINUE THIS MORNING. CHANCES FOR
CONVECTION WILL INCREASE LATER THIS MORNING AND ESPECIALLY DURING
THE AFTERNOON INTO EARLY EVENING HOURS AS THE SURFACE LOW PASSES
TO OUR NORTH AND ANOTHER SHORT WAVE TROUGH APPROACHES. WITH THE
HELP OF DAYTIME HEATING AND INCREASED INSTABILITY THERE WILL
BETTER AND WIDESPREAD CHANCES FOR SHOWERS AND THUNDERSTORMS SO
HAVE CONTINUED WITH A PROB30 GROUP IN THE TAF FOR THE THREAT OF
THUNDERSTORMS.

EXPECTING SOME MVFR FOG EARLY THIS MORNING WITH MVFR CIGS POSSIBLE.
VISIBILITIES IMPROVE AFTER SUNRISE. EXPECTING MAINLY VFR CONDITIONS
DURING THE DAY. MVFR AND BRIEF IFR CONDITIONS CAN BE EXPECTED WITH
ANY CONVECTION THAT IMPACTS TAF SITES. MVFR FIG IS EXPECTED TO
DEVELOP AGAIN THIS EVENING ESPECIALLY WHERE IT RAINS.

OUTLOOK...
SUNDAY-SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
LABOR DAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT AND WEDNESDAY: NO OPERATIONAL IMPACT.  NO SIG WX.


&&

.FIRE WEATHER...
A WARM HUMID SOUTHWEST FLOW OF AIR WILL REMAIN IN PLACE THROUGH
MONDAY. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT INTO
SATURDAY WITH A WEAK LOW PRESSURE SYSTEM...AND AGAIN ON LABOR DAY AS
STRONGER COLD FRONT PUSHES INTO THE REGION.

MAXIMUM RELATIVE HUMIDITY VALUES RISE TO AROUND 80 TO 100 PERCENT
TONIGHT. RH VALUES WILL ONLY DROP TO BETWEEN 50 AND 70 PERCENT ON
SATURDAY. WINDS TONIGHT WILL BE SOUTHWEST AROUND 5 MPH...BECOMING
LIGHT AND VARIABLE LATER TONIGHT. WINDS ON SATURDAY WILL BECOME
SOUTHERLY AND INCREASE TO AROUND 10 MPH. LIGHT AND VARIABLE WINDS
EXPECTED AGAIN ON SATURDAY NIGHT.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED THE NEXT 5 DAYS.

THE NEXT SEVERAL DAYS THROUGH THE LABOR DAY WEEKEND WILL
FEATURE PERIODS OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS.
THE BEST CHANCE WILL BE LATE TONIGHT THROUGH SATURDAY AND AGAIN ON
LABOR DAY.

HUMID CONDITIONS WILL PERSIST...SO LOCALIZED DOWNPOURS CAN BE
EXPECTED WITH THUNDERSTORMS. ISOLATED URBAN...SMALL STREAM AND POOR
DRAINAGE FLOODING WILL BE POSSIBLE DURING THE HOLIDAY WEEKEND. SOME
WITHIN BANK RISES ARE POSSIBLE ON LARGER STREAMS WHERE SHOWERS
AND STORMS OCCUR.

RAINFALL AMOUNTS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE
OF THE RAIN...WITH SOME LOCATIONS RECEIVING OVER AN INCH OF RAIN
WHILE OTHERS REMAIN DRY.

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...HWJIV/WASULA
NEAR TERM...WASULA
SHORT TERM...SND
LONG TERM...HWJIV
AVIATION...IAA
FIRE WEATHER...SND
HYDROLOGY...SND/JPV








AREA FORECAST DISCUSSION

NWS ALBANY NY

 137 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A SOUTHWEST FLOW OF WARM AND HUMID AIR...WILL COMBINE
WITH A WEAK LOW PRESSURE SYSTEM SLOWLY TRACKING EASTWARD THROUGH THE
SAINT LAWRENCE VALLEY TO PRODUCE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS THIS MORNING THROUGH SUNDAY. A MUCH STRONGER SYSTEM
WILL BRING A THREAT FOR MORE NUMEROUS SHOWERS AND THUNDERSTORMS ON
LABOR DAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 137 AM EDT...THE NRN HALF OF THE FCST AREA CONTINUES TO HAVE
SCT-NUMEROUS SHOWERS AND SOME THUNDERSTORMS AHEAD OF A MID-LEVEL
SHORT-WAVE AND A SFC TROUGH ASSOCIATED WITH RIPPLES OF LOW PRESSUE
MOVING ALONG THE ST LAWRENCE RIVER VALLEY. A FEW STRONGER
THUNDERSTORMS HAVE MOVED ACROSS THE SARATOGA REGION WITH FQT LTG
BRIEF BURSTS OF HVY RAIN...AND POSSIBLY SOME SMALL HAIL.

THE LATEST RUC HAS SHOWALTER VALUES OF 0 TO -2C. THE ELEVATED
INSTABILITY WILL LINGER WITH A SLIGHT TO LOW CHC OF THUNDERSTORMS
THIS MORNING...ESPECIALLY NEAR THE LOW-LEVEL CONVERGENT BOUNDARY.
THERE IS LESS LTG UPSTREAM AND SOME OF THE SHOWERS ARE STARTING
MOVE SOUTH OF THE MOHAWK VALLEY. SLIGHT OR LOW CHC POPS WERE USED
HERE...BUT SOME LOCATIONS MAY REMAIN DRY SOUTH AND EAST OF THE
CAPITAL REGION.

MUGGY CONDITIONS WILL CONTINUE WILL DEWPTS IN THE 60S. OVERNIGHT
LOWS WILL BE ABOVE NORMAL IN THE 60S ACROSS THE FCST AREA.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
FOR SATURDAY...WEAK LOW PRESSURE AT THE SURFACE AND
ALOFT WILL REMAIN OVER AND NORTH OF THE AREA. WITH WARM AND HUMID
AIRMASS IN PLACE...ONLY A WEAK TRIGGER NEEDED TO START SHOWERS AND
STORMS. MODELS DON`T INDICATE ANY PARTICULAR FORCING FOR THE
SHOWERS/STORMS SO PARTLY SUNNY CONDITIONS WITH A CHANCE OF
AFTERNOON SHOWERS AND THUNDERSTORMS LOOKS GOOD. FOR
SUNDAY...STRONG IMPULSE HAS REACHED THE WESTERN GREAT LAKES. THIS
WORKS TO INDUCE WEAK RIDGING ACROSS THE ALBANY FORECAST AREA.
THIS WEAK RIDGING/HIGH PRESSURE SHOULD KEEP GENERALLY FAIR WEATHER
OVER THE AREA WITH AGAIN A CHANCE FOR SHOWERS AND THUNDERSTORMS...
MAINLY SUNDAY AFTERNOON. BY LATE SUNDAY NIGHT...AN UPPER LEVEL
TROUGH...ASSOCIATED WITH DEEP GREAT LAKES LOW MAY BRING AN
INCREASED THREAT OF SHOWERS AND STORMS.

MAX/MIN TEMPERATURES GENERALLY A MOS BLEND. AREAS OF FOG EXPECTED
EACH MORNING WITH STEAMY AIRMASS IN PLACE.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
THE LONG TERM PERIOD WILL COINCIDE WITH THE BEGINNING OF
METEOROLOGICAL FALL (WHICH STARTS RIGHT ON LABOR DAY). THIS
YEAR...ALMOST ON QUE...OUR WEATHER WILL BECOME MUCH MORE AUTUMNAL
FEELING. HAVE LEANED HEAVILY WITH THE 12Z EUROPEAN MODEL...WHICH IS
FAIRLY CLOSE TO THE HPC GUIDANCE.

ON LABOR DAY ITSELF...WE WILL REMAIN IN A FAIRLY HUMID AND WARM AIR
MASS. A PRE-FRONTAL TROUGH LOOKS TO BE THE INITIAL TRIGGER EARLY ON
LABOR DAY. THE ACTUAL COLD FRONT...A FAIRLY STRONG ONE AT
THAT...WILL MOVE THROUGH OUR REGION LATE IN THE DAY OR MONDAY NIGHT
WITH THE POSSIBILITY OF ADDITIONAL SHOWERS OR THUNDERSTORMS. AT THIS
POINT IT IS VERY HARD TO NAIL DOWN THE EXACT TIMING OF THE
SYSTEMS...OR WHICH ONE WOULD BRING THE BULK OF CONVECTIVE ACTIVITY.

BY TUESDAY...THE 12Z EUROPEAN HAS THE COLD FRONT TO OUR EAST. THERE
IS STILL THE UPPER AIR TROUGH THAT NEEDS TO COME THROUGH TO OUR
NORTH...BUT THERE WILL BE LOT LESS AVAILABLE MOISTURE. THEREFORE WE
DROP POPS TO SLIGHT CHANCES (24 PERCENT BY TUESDAY).
MEANWHILE...H850 TEMPERATURES ARE FORECAST TO COOL FROM ABOUT +16C
TO +17C ON MONDAY...DOWN TO AROUND +9C BY LATE TUESDAY VIA A GUSTY
NORTHWEST BREEZE.

HIGH PRESSURE BUILDS INTO THE REGION BY WEDNESDAY. HOWEVER...IT WILL
BE DISPLACED TO THE SOUTH AND EAST AS YET ANOTHER COOLER COLD FRONT
MOVES THROUGH ON THURSDAY. THIS ONE SHOULD HAVE VERY LITTLE MOISTURE
TO WORK WITH AND SO WE ONLY ASSIGNED SLIGHT POPS FOR THURSDAY.

BEHIND THE SECOND COLD FRONT COMES THE COOLEST AIRMASS SINCE LAST
MAY! EVEN THOUGH FORECAST H850 TEMPS WERE NOT AS COOL ON THIS RUN
COMPARED TO PREVIOUS ONES...TE EUROPEAN MODEL STILL INDICATED THEY
WOULD BE COOLING DOWN TO A RANGE BETWEEN +2C IN OUR NORTHERN
ZONES...TO ABOUT +5C IN OUR SOUTHERN ZONES BY FRIDAY.


TEMPERATURES ON LABOR DAY LOOK TO MAX OUT BETWEEN THE UPPER 70S
ACROSS THE MOUNTAINS...TO 80-85 ACROSS THE MAJORITY OF OUR COUNTY
WARNING AREA. THIS ASSUMES PLENTY OF CLOUD COVER. IF WE WERE TO
RECEIVE MORE BREAKS OF SUNSHINE IT COULD BE A LITTLE WARMER THAN
WHAT WE ARE FORECASTING ALONG WITH AN INCREASED RISK OF STRONGER
THUNDERSTORMS. EITHER WAY...IT WILL BE HUMID.

LOWS MONDAY NIGHT WILL RANGE BETWEEN THE UPPER 50S TO MID 60S.
TUESDAY WILL SEE HIGHS NEAR 80 AROUND POUGHKEEPSIE...MAINLY IN THE
70S ELSEWHERE...EXCEPT UPPER 60S OVER THE HIGHEST MOUNTAIN AREAS. A
BREEZE ON TUESDAY NIGHT MIGHT KEEP TEMPERATURES FROM FALLING MORE
THAN THEY WOULD HAVE OTHERWISE. A LITTLE COOLER TUESDAY NIGHT WITH
LOWS RANGING FROM THE MID 40S TO MID 50S.

WEDNESDAY MIGHT BE THE PICK OF THE WEAK...WITH LOW HUMIDITY...LOTS
OF SUNSHINE AND TEMPERATURES IN THE 70S. WEDNESDAY NIGHT LOWS WILL
BE SIMILAR TO TUESDAY...45 TO 55.

THURSDAY...AS THE H850 TEMPERATURES DIP INTO THE SINGLE
NUMBERS...THERE COULD BE A LOT OF CLOUD COVER AROUND AND THOSE
ISOLATED SHOWERS. HIGH TEMPERATURES THAT DAY MIGHT NOT GET OUT OF
THE 60S FROM ALBANY NORTHWARD...EVEN UPPER 50S ACROSS MUCH OF THE
ADIRONDACK PARK. EVEN FURTHER SOUTH...ONLY LOWER 70S FOR A HIGH
ACROSS THE MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY.

ENOUGH COLD AIR ADVECTION CLOUDS AND A GRADIENT WOULD BE ONLY THING
PREVENTING TEMPERATURES FROM REACHING FROSTY LEVELS IN OUR
ADIRONDACKS BY THURSDAY NIGHT. WE EXPECT BOTH THE CLOUDS AND A BIT
BREEZE TO HOLD TEMPERATURES UP A LITTLE...AS THEY WILL RANGE FROM
THE LOWER 40S NORTHWEST TO THE LOWER 50S NORTHWEST BY FRIDAY
MORNING.

TEMPERATURES ONCE AGAIN LOOK TO BE HELD MAINLY TO THE 60S ON FRIDAY
DESPITE A GOOD DEAL OF SUNSHINE.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
A LOT OF DEBRIS HIGH AND MID LEVEL CLOUDS SHOULD PREVENT THE
FORMATION OF IFR FOG TONIGHT. HOWEVER...SHOWERS AND EVEN
THUNDERSTORMS MIGHT IMPACT THE TAFS LATER OVERNIGHT.

WE ARE FOLLOWING A LINE OF SHOWERS AND THUNDERSTORMS WELL TO THE
WEST OF THE TERMINALS AS OF 745 PM EDT. WE EXPECT NO PROBLEMS
THROUGH THE EVENING HOURS AND ALL OF OUR SITES LOOK TO REMAIN VFR.
AS OF 930 PM EDT...WE HAD TO PLACE VCSH IN THE KALB AND KGFL CLOSER
TO 03Z BASED ON WHAT WE ON RADAR. SHOWERS WERE WORKING INTO THE
MOHAWK VALLEY TOWARD HERKIMER COUNTY.

CONFIDENCE REMAINED TOO LOW TO INCLUDE THUNDER (EVEN AS A TEMPO) AS
THE PROBABILITY OF THESE DIRECTLY IMPACTING A TAF SITE WAS ABOUT 25
PERCENT. WE WILL MONITOR THROUGHOUT THE EVENING HOURS...AND IF
CONFIDENCE INCREASES WE WILL UPDATE THE TAFS.

ASSUMING NOT A WHOLE LOT OF RAIN AND THE CLOUD COVER...SOME KGFL AND
KPSF MIGHT GO MVFR WITH SOME HAZE AND MVFR CIGS. HOWEVER...FOR
NOW...WE KEPT KALB AND KPOU VFR THROUGHOUT THE NIGHT (ADDING A
LITTLE HAZE BUT ONLY LOWERING VSBY TO 6SM).

LATER ON SATURDAY...THE CONVECTION THREAT LOOKS TO INCREASE AS A
SYSTEM OUT IN THE GREAT LAKES HEADS OUR WAY INCREASING INSTABILITY.
WE DECIDED TO INCLUDE A PROB30 GROUP FOR THUNDER AND MVFR MAINLY
DURING SATURDAY AFTERNOON AS THE THREAT OF A THUNDERSTORM IMPACTING
ANY TAF SITE IS ABOUT 30-49 PERCENT...UP TO HALF OF THE TIME.

THE SURFACE WIND WILL BE LIGHT OR SOUTH UNDER 5KTS
TONIGHT...INCREASING TO NEAR 10KTS LATER ON SATURDAY.

OUTLOOK...

SATURDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUNDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
SUNDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
LABOR DAY: HIGH OPERATIONAL IMPACT. LIKELY SHRA...TSRA.
MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
TUESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
TUESDAY NIGHT AND WEDNESDAY: NO OPERATIONAL IMPACT.  NO SIG WX.

&&

.FIRE WEATHER...
A WARM HUMID SOUTHWEST FLOW OF AIR WILL REMAIN IN PLACE THROUGH
MONDAY. THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TONIGHT INTO
SATURDAY WITH A WEAK LOW PRESSURE SYSTEM...AND AGAIN ON LABOR DAY AS
STRONGER COLD FRONT PUSHES INTO THE REGION.

MAXIMUM RELATIVE HUMIDITY VALUES RISE TO AROUND 80 TO 100 PERCENT
TONIGHT. RH VALUES WILL ONLY DROP TO BETWEEN 50 AND 70 PERCENT ON
SATURDAY. WINDS TONIGHT WILL BE SOUTHWEST AROUND 5 MPH...BECOMING
LIGHT AND VARIABLE LATER TONIGHT. WINDS ON SATURDAY WILL BECOME
SOUTHERLY AND INCREASE TO AROUND 10 MPH. LIGHT AND VARIABLE WINDS
EXPECTED AGAIN ON SATURDAY NIGHT.

&&

.HYDROLOGY...
NO WIDESPREAD HYDRO PROBLEMS ARE ANTICIPATED THE NEXT 5 DAYS.

THE NEXT SEVERAL DAYS THROUGH THE LABOR DAY WEEKEND WILL
FEATURE PERIODS OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS.
THE BEST CHANCE WILL BE LATE TONIGHT THROUGH SATURDAY AND AGAIN ON
LABOR DAY.

HUMID CONDITIONS WILL PERSIST...SO LOCALIZED DOWNPOURS CAN BE
EXPECTED WITH THUNDERSTORMS. ISOLATED URBAN...SMALL STREAM AND POOR
DRAINAGE FLOODING WILL BE POSSIBLE DURING THE HOLIDAY WEEKEND. SOME
WITHIN BANK RISES ARE POSSIBLE ON LARGER STREAMS WHERE SHOWERS
AND STORMS OCCUR.

RAINFALL AMOUNTS WILL BE QUITE VARIABLE DUE TO THE SHOWERY NATURE
OF THE RAIN...WITH SOME LOCATIONS RECEIVING OVER AN INCH OF RAIN
WHILE OTHERS REMAIN DRY.

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...HWJIV/WASULA
NEAR TERM...WASULA
SHORT TERM...SND
LONG TERM...HWJIV
AVIATION...HWJIV
FIRE WEATHER...SND
HYDROLOGY...SND/JPV








AREA FORECAST DISCUSSION

NWS MELBOURNE FL

 1010 PM EDT SUN SEP 1 2013

.DISCUSSION...
ANOTHER ROUND OF DIURNAL CONVECTION HAS BURNED ITSELF OUT. SIMILAR
SET UP TO SATURDAY EVENING AS FAR AS DEVELOPMENT FROM SOUTH TO NORTH
WITH POCKETS OF STRONG CONVECTION. SFC WND GUSTS BTWN 30-35KTS
RECORDED AT KMCO/KORL/KSFB...ONE SFC REPORT EST ARND 50MPH...BUT NO
CONFIRMED SVR WX.

LATEST RUC ANALYSIS SHOWING A BROAD SUBTROPICAL RIDGE AXIS OVER S FL
AND THE FL STRAITS...REFLECTED WELL IN THE EVENING SOUNDINGS WITH
S/SW WINDS AT KJAX/KTBW...S/SE SFC/LOW LVL WINDS AOB 5KTS AT KMFL
BCMG SW ABV H85. LITTLE PROSPECT FOR REDEVELOPMENT OVERNIGHT...WILL
UPDATE FCST SHORTLY TO REMOVE PRECIP AND ADJUST SKY COVER FOR
LINGERING DEBRIS CLOUDS THRU EARLY MRNG. NO OTHER CHANGES NECESSARY.

&&

.AVIATION...
THRU 02/14Z...VFR ALL SITES...S/SW SFC WND 5-10KTS BCMG L/V THRU
02/06Z. BTWN 02/14Z-02/16Z...VFR ALL SITES...SW SFC WND BTWN
5-10KTS. BTWN 02/16Z-02/18Z...SFC WND BCMG E/SE ARND 10KTS COASTAL
SITES ASSOCD WITH THE EAST COAST SEA BREEZE. BTWN 02/18Z-02/23Z VCTS
ALL SITES.

&&

.MARINE...
BROAD SUBTROPICAL RIDGE AXIS OVER S FL AND THE FL STRAITS WILL
MAINTAIN A LIGHT TO GENTLE S/SWRLY BREEZE ACRS THE LCL ATLC
OVERNIGHT...SFC WINDS STRONGER THRU MIDNIGHT NEAR LINGERING
CONVECTION N OF DAYTONA BEACH. SEAS AOB 2FT NEARSHORE AND 2-3FT
OFFSHORE...MAINLY IN A 9-10SEC PD SWELL.

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.

&&

$$

FORECAST....BRAGAW
IMPACT WX...MOSES/BOWEN








AREA FORECAST DISCUSSION

NWS MIAMI FL

 1002 AM EDT SAT AUG 31 2013

...MORE THUNDERSTORMS EXPECTED THIS AFTERNOON THAN RECENT DAYS...

.UPDATE...THE MORNING MIAMI SOUNDING SHOWS SUBSTANTIAL MOISTENING
HAS OCCURRED IN THE LOWEST 10K FT. SO THE DRY LAYER OF THE PAST
COUPLE OF DAYS HAS DIMINISHED. GIVEN THIS MOISTENING, THE
EXPECTATION FOR THIS AFTERNOON IS FOR A HIGHER COVERAGE OF SHOWERS
AND THUNDERSTORMS ACROSS SOUTH FL. HRRR SHOWS CONVECTION
DEVELOPING AFTER 1 PM ACROSS THE EAST COAST METRO AREAS JUST
INLAND FROM THE COAST WITH A TRANSITION OVER THE INTERIOR THROUGH
EARLY THIS EVENING WITH ACTIVITY BECOMING NUMEROUS THERE. THIS
LOOKS REASONABLE SO HAVE UPDATED THE FORECAST TO REFLECT THIS
TREND.

LAPSE RATES ARE RATHER WEAK AND INSTABILITY IS NOT TOO
HIGH, AND WITH NO PRONOUNCED DRY LAYER, WE ARE EXPECTING MAINLY
ORDINARY THUNDERSTORMS WITH LIGHTNING STRIKES AND HEAVY DOWNPOURS
BEING THE PRIMARY IMPACTS. /GREGORIA

&&

.PREV DISCUSSION... /ISSUED 643 AM EDT SAT AUG 31 2013/

AVIATION...
AN UPPER LEVEL LOW WILL CONTINUE TO BRING UNCERTAINTY IN THE
FORECAST FOR SOUTH FLORIDA. AS IT DRIFTS AROUND THE AREA, IT WILL
ALLOW SOME CONVECTION TO INITIATE THROUGH THE DAY, WITH THE BEST
CHANCES IN THE AFTERNOON. WHILE THE MOST LIKELY AREAS WILL BE THE
INTERIOR AND THE LAKE REGION, SOME MODELS ARE NOW INDICATING THE
ATLANTIC COASTAL TAF SITES MAY AT LEAST SEE SOME SHOWERS AROUND.
SO, HAVE ADDED VCSH BACK INTO THE FORECAST FOR THOSE SITES FOR
THIS AFTERNOON. VCTS IS STILL A SMALL POSSIBILITY, BUT CURRENTLY
TOO SMALL TO PUT IN THE TAF FORECAST AT THIS TIME.

GENERALLY SOUTHERLY WINDS WILL CONTINUE TODAY, PICKING UP TO 5 TO
10 KTS MID DAY. THEY WILL BECOME LIGHT AND VARIABLE AGAIN TONIGHT,
WITH MOST LIKELY SOUTHERLY DIRECTION SOMEWHAT FAVORED.

PREV DISCUSSION... /ISSUED 243 AM EDT SAT AUG 31 2013/

.ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE FOR
THE HOLIDAY WEEKEND...

SHORT TERM...
AN UPPER LEVEL LOW WILL REMAIN OVER SOUTH FLORIDA TODAY INTO
SUNDAY...AS WEAK HIGH PRESSURE REMAINS OVER THE WESTERN ATLANTIC
WATERS. THIS WILL ALLOW FOR A STEERING FLOW OVER SOUTH FLORIDA TO
BE FROM THE SOUTHERLY DIRECTION WHICH WILL FOCUS THE SHOWER AND
THUNDERSTORM ACTIVITY OVER THE LAKE OKEECHOBEE REGION TODAY AND
AGAIN ON SUNDAY.

THE DRY AIR WAS STILL LOCATED BETWEEN THE 850 MB AND 700 MB IN
FRIDAY THE 00Z MIA SOUNDING. THIS DRY AIR WILL REMAIN IN PLACE
TODAY INTO SUNDAY HELPING TO REDUCE THE SHOWER AND THUNDERSTORM
ACTIVITY OVER SOUTH FLORIDA. THEREFORE...THE POPS OVER SOUTH
FLORIDA WILL RANGE FROM 20 PERCENT OVER THE SOUTHERN AREAS TO 40
PERCENT OVER THE LAKE OKEECHOBEE AREA FOR TODAY AND AGAIN ON
SUNDAY.

THE UPPER LEVEL LOW EXPECTED MOVE WEST ON LABOR DAY INTO THE GULF
WATERS OF MEXICO...AS THE HIGH OVER THE WESTERN ATLANTIC WATERS
BUILDS BACK INTO THE FLORIDA PENINSULA. THIS WILL ALLOW FOR THE
DRY AIR BETWEEN THE 700 MBS AND 850 MBS TO MOISTEN UP ALONG WITH
THE STEERING FLOW BECOMING MORE SOUTHEAST OVER THE AREA. THE SEA
BREEZES WILL ALSO DEVELOP AND PUSH INLAND. SO THE POPS WILL BE
INCREASED TO SCATTERED COVERAGE WITH THE HIGHEST POPS OVER THE
INTERIOR AREAS FOR LABOR DAY.

LONG TERM...
THE HIGH OVER THE WESTERN ATLANTIC WATERS WILL CONTINUE TO
STRENGTHEN OVER THE WESTERN ATLANTIC WATERS AND EXTEND INTO THE
FLORIDA PENINSULA MIDDLE TO END OF NEXT WEEK. THIS WILL ALLOW FOR
THE EASTERLY WIND FLOW TO REMAIN IN PLACE OVER SOUTH FLORIDA
FOR MIDDLE TO END OF NEXT WEEK ALONG WITH THE DAILY SEA BREEZE
DEVELOPMENT. SO WILL CONTINUE THE SCATTERED POPS OVER SOUTH
FLORIDA WITH THE BEST COVERAGE OVER THE INTERIOR AND WEST COAST
METRO AREAS FOR MIDDLE TO END OF NEXT WEEK.

THERE IS ALSO A TROPICAL WAVE OVER THE CENTRAL ATLANTIC WATERS
THAT IS FORECAST BY THE LONG RANGE MODELS TO MOVE WEST-NORTHWEST
NEXT WEEK...AND POSSIBILITY OVER SOUTH FLORIDA BY END OF NEXT
WEEK. IF THIS TREND CONDITIONS THEN THE POPS MAY HAVE TO BE RAISED
UP FOR END OF NEXT WEEK.

MARINE...
THE WINDS OVER SOUTH FLORIDA WATERS THIS LABOR DAY WEEKEND WILL BE
FROM THE SOUTH-SOUTHWEST DIRECTION AT 5 TO 10 KNOTS SWINGING TO A
EASTERLY DIRECTION BY LABOR DAY. THIS WILL KEEP THE SEAS IN BOTH
THE ATLANTIC AND GULF WATERS AT 2 FEET OR LESS. SO BOATING
CONDITIONS OVER SOUTH FLORIDA THIS LABOR DAY WEEKEND SHOULD BE
GOOD OUTSIDE OF ANY SHOWERS OR THUNDERSTORMS.

THE THREAT OF RIP CURRENTS THIS LABOR DAY WEEKEND AT BOTH THE
ATLANTIC AND GULF COAST BEACHES OF SOUTH FLORIDA LOOKS LOW AT
THIS TIME AS THE WINDS WILL BE 10 KNOTS OR LESS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  91  77  91  78 / 30 20 30 20
FORT LAUDERDALE  90  79  90  80 / 20 20 20 20
MIAMI            91  78  91  79 / 30 20 20 20
NAPLES           90  75  90  76 / 20 20 20 20

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$





AREA FORECAST DISCUSSION

NWS PEACHTREE CITY GA

 928 PM EDT SUN SEP 1 2013

.UPDATE...NEXT IN A SERIES OD SHORTWAVES IN NORTHWEST FLOW ALOFT
PUSHED THROUGH THE FORECAST AREA THIS EVENING WITH A NEARLY
CONTINUOUS LINE AFFECTING THE ATLANTA METRO AND POINTS SOUTHWARD.
ONLY ISOLATED REPORTS OF TREES DOWN HOWEVER AS ACTIVITY WAS
LARGELY BENIGN DESPITE ITS ORGANIZED STRUCTURE. ACTIVITY HAS
SUBSIDED SIGNIFICANTLY BUT ADDITIONAL SHORTWAVE ENERGY UPSTREAM
ALREADY PRODUCING ACTIVITY OVER TENNESSEE AT THIS HOUR. HRRR AND
LOCAL WRF BOTH SHOWING POSSIBLE DEVELOPMENT INTO THE OVERNIGHT
HOURS BUT DIFFER ON EXACT TIMING. FOR NOW...WILL LEAVE GRIDS AS
THEY STAND WHICH BRINGS CHANCE POPS BACK TO THE NORTH JUST PRIOR
TO DAYBREAK. NO CHANGES PLANNED AT THIS TIME.


&&

DEESE

.PREV DISCUSSION... /ISSUED 755 PM EDT SUN SEP 1 2013/

PREV DISCUSSION... /ISSUED 339 PM EDT SUN SEP 1 2013/

SHORT TERM /TONIGHT THROUGH MONDAY/...
UPPER TROUGH DEEPENS OVER THE GREAT LAKES THROUGH TOMORROW. SEVERAL
RIPPLES NOTED IN THE UPPER LEVEL FLOW TODAY ENHANCING CONVECTION.
SHORT TERM HIRES MODELS NOT HANDLING CURRENT CONVECTION WELL. GOOD
MOISTURE...AND INSTABILITY NOTED ACROSS THE FORECAST AREA...CAPES
APPROACHING 2000...AS AN OUT FLOW BOUNDARY FROM THIS MORNINGS
CONVECTION ACROSS NORTH GA...AIDED IN THE DEVELOPMENT OF A LINE OF
SHOWERS AND THUNDERSTORMS FROM CARROLLTON TO ATLANTA TO ATHENS.
THIS LINE WILL SAG SLOWLY SOUTHWARD THROUGH THIS EVENING. HRRR
HINTING AT ANOTHER LINE DEVELOPING OVER EASTER AL JUST BEFORE
SUNSET IMPACTING PORTIONS OF WEST AND CENTRAL GA THROUGH LATE
EVENING...WITH THE AREA ALREADY WORKED OVER AM NOT BITING ON THIS
SOLUTION AT THIS TIME. WILL CONTINUE TO SHOW CONVECTION SHIFTING
TO THE SOUTH SIDE OF ATL TO AHN AFTER 4-5PM AND IMPACTING CSG-MCN
BETWEEN 6-9 PM.

MODELS SHOWING MOISTURE AND INSTABILITY LINGERING OVERNIGHT...AND
ISOLATED STORMS WILL CONTINUE TO BE POSSIBLE. ECMWF/GFS/NAM ALL
SHOWING MCS POSSIBLE BY 12Z MONDAY NOW AND HAVE CONTINUED CHANCE
POPS ACROSS NORTH GEORGIA TO ACCOUNT FOR THE FEATURE. WEAK SURFACE
FRONT CONTINUES TO APPROACH NORTH GEORGIA TOMORROW AND WITH GOOD
MOISTURE AND INCREASING INSTABILITY ONCE AGAIN EXPECT SCATTERED
SHOWERS/THUNDERSTORMS ACROSS THE AREA ON MONDAY.

CONTINUED TO USE A BIAS CORRECTED BLEND OF GUIDANCE TEMPERATURES
ACROSS THE AREA THROUGH THE SHORT TERM PERIODS...ALTHOUGH MAX
TEMPERATURES MONDAY WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF LOW
LEVEL CLOUDS THAT ARE ABLE TO DEVELOP IN RAIN SOAKED AREAS TONIGHT.

ATWELL

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ONLY MINOR TWEAKS MADE TO THE EXTENDED. DID RAISE TEMPERATURES FOR
SATURDAY/SUNDAY A DEGREE OR SO BUT STILL LOOKING LIKE THE COOLEST
DAYS OF EXTENDED PERIOD.
PREV DISCUSSION... /ISSUED 324 AM EDT SUN SEP 1 2013/
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED BEGINS WITH AN UPPER LOW OVER SOUTHERN ONTARIO...
TROUGHING DOWN THE EASTERN THIRD OF THE U.S...WITH THE ASSOCIATED
COLD FRONT PUSHING THROUGH THE SOUTHEAST. PRECIP CHANCES CONTINUE
ACROSS THE STATE MONDAY NIGHT BUT AS THE FRONT PUSHES TOWARD THE
COAST TUESDAY AND TUESDAY NIGHT...DRIER AIR FILTERS IN BEHIND IT
AND PUSHES PRECIP CHANCES INTO CENTRAL AND SOUTH GEORGIA. DRIEST
DAY LOOKS TO BE WEDNESDAY AS THE TROUGH AXIS SHIFTS EAST OFF THE
COAST AND HIGH PRESSURE DOMINATES MOST OF THE STATE. HOWEVER...ON
THURSDAY ANOTHER SHORTWAVE ROUNDS THE BASE OF THE TROUGH AND LOOKS
TO PROVIDE ENOUGH LIFT THAT WHEN COMBINED WITH OROGRAPHIC LIFTING
IS ENOUGH TO WARRANT SLIGHT TO LOW CHANCE POPS IN THE NORTHEAST
MOUNTAINS. ECMWF IS A LITTLE STRONGER WITH THIS SHORTWAVE
INITIALLY BUT BOTH MODELS IN REASONABLE AGREEMENT WITH THIS
FEATURE ON FRIDAY. AS WE PUSH INTO THE WEEKEND...THE GFS IS
DEFINITELY THE WETTER OF THE TWO MODELS SO COMPROMISED ON THIS
UNCERTAINTY BY PAINTING GENERALLY SLIGHT CHANCE POPS ACROSS THE
AREA ON SATURDAY.

AS FOR TEMPS...TUESDAY WILL CONTINUE THE TREND OF ABOVE-NORMAL
TEMPS...AND EVEN WITH THE FRONTAL PASSAGE TEMPS WILL ONLY DROP A
COUPLE OF DEGREES BUT SHOULD BE NEAR SEASONAL NORMALS. THE MORE
NOTICEABLE CHANGE WILL BE IN OVERNIGHT LOWS...LIKELY DROPPING AT
LEAST 5 DEGREES BETWEEN MONDAY NIGHT AND WEDNESDAY NIGHT. SATURDAY
IS A BIT FAR OUT THERE BUT WITH THE INFLUENCE OF THE STRONG
SHORTWAVE /INCREASED CLOUDINESS/...RIGHT NOW THAT LOOKS TO BE THE
COOLEST DAY OF THE PERIOD.

TDP

AVIATION...
00Z UPDATE...
LINE OF CONVECTION CONTINUES TO SLOWLY SAG SOUTHWARD...WITH THE
MAIN IMPACT OF WIND GUSTS AT MCN FOR THE NEXT HOUR OR SO. VFR
CONDITIONS EXPECTED OUTSIDE OF CONVECTION. LOW CLOUDS WILL DEVELOP
TOWARD MORNING AIDED BY THE SATURATED GROUND WITH IFR/LOW MVFR
CIGS EXPECTED AROUND DAYBREAK. WEST WINDS WILL PREVAIL THROUGH
THE PERIOD AT GENERALLY 8KTS OR LESS.

//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE IN WINDS...VISIBILITY.
MEDIUM CONFIDENCE IN CIGS OVERNIGHT...CONVECTIVE TIMING.

ATWELL

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          70  90  72  90 /  40  30  30  30
ATLANTA         73  90  74  90 /  40  40  30  30
BLAIRSVILLE     66  84  68  84 /  30  50  30  20
CARTERSVILLE    71  89  71  90 /  40  40  40  20
COLUMBUS        75  93  74  90 /  50  40  30  30
GAINESVILLE     69  88  73  89 /  40  40  30  20
MACON           71  91  72  91 /  50  40  40  30
ROME            70  90  72  90 /  40  50  40  20
PEACHTREE CITY  69  90  71  89 /  40  40  30  30
VIDALIA         74  93  74  90 /  40  30  30  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...DEESE
LONG TERM....11
AVIATION...DEESE






AREA FORECAST DISCUSSION

NWS CHARLESTON SC

 706 PM EDT SUN SEP 1 2013

.SYNOPSIS...
WEAK ATLANTIC HIGH PRESSURE WILL RESIDE OVER THE AREA THROUGH THE
EARLY PART OF THE WEEK. A WEAK COLD FRONT WILL PUSH INTO THE AREA
TUESDAY NIGHT AND WEDNESDAY...THEN DISSIPATE. HIGH PRESSURE WILL
THEN BUILD TO THE NORTH OF THE AREA FOR LATE WEEK INTO NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
GOES-EAST SATELLITE TRENDS AND RAP VORTICITY DATA SUGGEST BROAD
SUBSIDENCE REMAINS IN PLACE EARLY THIS EVENING. CUMULUS IS QUICKLY
DISSIPATING AS SUNSET APPROACHES AND WATER VAPOR LOOPS SHOW THE
MID-LEVELS OF THE ATMOSPHERE CONTINUE TO DRY. THE PROSPECTS FOR
MEASURABLE RAINFALL...AT LEAST DURING THE NEXT FEW HOURS...LOOKS
GRIM GIVEN THE TRENDS NOTED ABOVE. HOWEVER...THE RAP AND H3R WITH
SUPPORT FROM THE 01/12Z 4KM NSSL WRF ALL SUGGEST THE LARGE
CONVECTIVE OUTFLOW MOVING RAPIDLY EAST ACROSS CENTRAL GEORGIA AND
INTO THE WESTERN MIDLANDS WILL MEET UP WITH THE INLAND MOVING SEA
BREEZE AND SPARK OFF SHOWERS/TSTMS AFTER DARK. WE ARE A BIT
SKEPTICAL OF THIS SOLUTION GIVEN THE SEEMINGLY UNFAVORABLE
ENVIRONMENT THAT IS IN PLACE...HOWEVER IT IS INTERESTING THAT ALL
THREE HIGH RESOLUTION MODELS ARE DEPICTING A SIMILAR SCENARIO. AM
THEREFORE HESITANT TO REMOVE POPS GIVEN THIS AGREEMENT. WILL
MAINTAIN SLIGHT CHANCE POPS THROUGH MIDNIGHT WITH LOW-END CHANCE
POPS ACROSS FAR INTERIOR SOUTHEAST GEORGIA...BUT FURTHER
REFINEMENTS MAY BE NEEDED LATER THIS EVENING ONCE SHORT TERM
CONVECTIVE TRENDS BECOME MORE APPARENT. LOWS WILL RANGE FROM THE
LOWER 70S WELL INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
I DID NOT MAKE MUCH CHANGE TO THE EARLY WEEK FORECAST AS THE OVERALL
PATTERN IS GOING TO EVOLVE PRETTY MUCH AS EXPECTED. AN UPPER TROF
WILL DIG IN ALOFT OVER THE AREA MONDAY AND TUESDAY...HELPING TO TO
DRAG A SLOW MOVING COLD FRONT INTO THE AREA FROM THE NORTHWEST AND
NORTH. WEAK DISTURBANCES WITHIN THE LONG WAVE TROF...ALONG WITH
DAYTIME TEMPS INTO THE 90S AWAY FROM THE IMMEDIATE COAST...WILL CAUSE
SCATTERED AFTERNOON AND EVENING CONVECTION. THE SURFACE PRESSURE
GRADIENT BETWEEN WEAK HIGH PRESSURE IN THE WESTERN ATLANTIC AND THE
AFTERNOON LEE TROF WILL KEEP WINDS OUT OF THE SOUTHWEST...ACTING TO
RETARD THE INLAND MOVEMENT OF THE SEABREEZE DURING THE AFTERNOON
HOURS. THAT WILL KEEP TEMPS WARM AND GIVE COASTAL AREAS ALMOST AS
MUCH CHANCE OF GETTING CAUGHT BY ONE OF THE LATER DAY
SHOWERS/TSTMS AS THE INTERIOR AREAS.

TUESDAY NIGHT...THE WEAK FRONT PUSHES INTO THE CWA. WITH THE UPPER
LEVEL SUPPORT FOR THE FRONT RIPPING AWAY QUICKLY TO THE
NORTHEAST...MID LEVEL HEIGHTS WILL ACTUALLY BUILD
OVERNIGHT...HELPING TO MAKE THE FRONT GRADUALLY MORE DIFFUSE INTO
WEDNESDAY. THE FRONT MAY HAVE A HARD TIME PUSHING THROUGH THE
GEORGIA COUNTIES...SO I HAVE WARMER TEMPS THERE...WITH ONSHORE WINDS
INCREASING...KEEPING AREAS CLOSER TO THE COAST COOLER THAN DURING
MONDAY AND TUESDAY. THERE COULD ALSO BE SOME STUBBORN LOW CLOUDS AND
FOG DURING WEDNESDAY...KEEPING TEMPS DOWN A LITTLE DUE TO LESS
SUNSHINE. I HAVE NOT YET PUT FOG IN THE FORECAST AS THE DETAILS OF
THE FAVORED LOCATION ARE STILL TOO TOUGH TO PIN DOWN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CANADIAN HIGH PRESSURE WILL PREVAIL FOR THE BEGINNING OF THE PERIOD
BUT STEADILY SHIFT EAST WITH A RETURN FLOW SETTING UP ON THE SW
PERIPHERY. MOST AREAS WILL BE DRY WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. DIURNAL CONVECTION RETURNS TO THE FORECAST FRIDAY THROUGH
SUNDAY AS LOW-LEVEL MOISTURE INCREASES AND ANOTHER UPPER TROUGH SETS
UP SHOP.

&&

.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
VFR IS EXPECTED TO PREVAIL THROUGH MAJORITY OF THE TAF CYCLE. HI RES
MODELS HINT THAT SOME SHOWERS/THUNDERSTORMS COULD DEVELOP BETWEEN
00-06Z..HOWEVER PROBABILITIES OF A DIRECT IMPACT AT EITHER TERMINAL
IS LOW SO HAVE OPTED TO LEAVE MENTION OUT OF TAF. WILL AMEND IF
NEEDED. OTHERWISE NO SIGNIFICANT AVIATION CONCERNS EXPECTED
OVERNIGHT. SHOWERS/THUNDERSTORMS AND ASSOCIATED RESTRICTIONS WILL BE
POSSIBLE AGAIN MONDAY AFTERNOON. WILL WAIT UNTIL LATER ISSUANCES TO
ADDRESS THIS WHEN TIMING AND COVERAGE IS BETTER DEFINED.

EXTENDED AVIATION OUTLOOK...DIURNAL CONVECTION POSSIBLE MONDAY AND
TUESDAY. THERE MAY BE SOME FOG AND LOW CIG ISSUES TUESDAY NIGHT
AND WEDNESDAY AS THE FRONT HANGS UP OVER THE AREA.

&&

.MARINE...
TONIGHT...THE PRESSURE GRADIENT WILL GRADUALLY TIGHTEN THROUGH THE
PERIOD WITH THE SHARPENING OF THE INLAND SURFACE TROUGH. THIS WILL
RESULT IN A MODEST SOUTHWEST SURGE. SPEEDS WILL REACH THE 15-20 KT
RANGE...ESPECIALLY ACROSS THE CHARLESTON COUNTY WATERS...BUT ARE
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS. SEAS WILL
TICK UPWARD A BIT IN RESPONSE TO THE STRONGER WINDS...WITH 4 FT SEAS
GETTING INTO THE SOUTH CAROLINA WATERS LATE TONIGHT.

SOUTHWEST WINDS ON MONDAY MAY VEER SLIGHTLY ONSHORE DURING THE
AFTERNOON...BUT WILL QUICKLY SWITCH BACK TO SOUTHWEST AND INCREASE
DURING THE EVENING AS THE TYPICAL DIURNAL SURGE KICKS IN. I DID
RAISE WINDS A TOUCH DURING MONDAY EVENING...BUT STILL WELL BELOW
ANY SCA CRITERIA. SEAS WILL BE AOB 4 FEET AS WELL. I EXPECT A
SIMILAR SITUATION TUESDAY...ALTHOUGH THE WINDS MAY NOT BE QUITS AS
STRONG TUESDAY EVENING WITH THE GRADIENT STARTING TO RELAX. BY
TUESDAY NIGHT AND WEDNESDAY...THE GRADIENT BECOMES NEARLY NON
EXISTENT WITH WINDS GENERALLY 10 KNOTS OR LESS AND SEAS 2 FEET OR
LESS. I CANT RULE OUT THE POSSIBILITY OF SOME GROUND FOG BLEEDING
INTO THE NEARSHORE WATERS EARLY WEDNESDAY MORNING...BUT ITS TOO
EARLY TO MAKE THAT CALL. HIGH PRESSURE WILL BUILD TO THE NORTH OF
THE AREA FOR LATER IN THE WEEK...VEERING THE WINDS TO EAST AND
SOUTHEAST...BUT NOT PARTICULARLY STRONG.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST/ECT







AREA FORECAST DISCUSSION

NWS CHARLESTON SC

 636 PM EDT SUN SEP 1 2013

.SYNOPSIS...
WEAK ATLANTIC HIGH PRESSURE WILL RESIDE OVER THE AREA THROUGH THE
EARLY PART OF THE WEEK. A WEAK COLD FRONT WILL PUSH INTO THE AREA
TUESDAY NIGHT AND WEDNESDAY...THEN DISSIPATE. HIGH PRESSURE WILL
THEN BUILD TO THE NORTH OF THE AREA FOR LATE WEEK INTO NEXT
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
GOES-EAST SATELLITE TRENDS AND RAP VORTICITY DATA SUGGEST BROAD
SUBSIDENCE REMAINS IN PLACE EARLY THIS EVENING. CUMULUS IS QUICKLY
DISSIPATING AS SUNSET APPROACHES AND WATER VAPOR LOOPS SHOW THE
MID-LEVELS OF THE ATMOSPHERE CONTINUE TO DRY. THE PROSPECTS FOR
MEASURABLE RAINFALL...AT LEAST DURING THE NEXT FEW HOURS...LOOKS
GRIM GIVEN THE TRENDS NOTED ABOVE. HOWEVER...THE RAP AND H3R WITH
SUPPORT FROM THE 01/12Z 4KM NSSL WRF ALL SUGGEST THE LARGE
CONVECTIVE OUTFLOW MOVING RAPIDLY EAST ACROSS CENTRAL GEORGIA AND
INTO THE WESTERN MIDLANDS WILL MEET UP WITH THE INLAND MOVING SEA
BREEZE AND SPARK OFF SHOWERS/TSTMS AFTER DARK. WE ARE A BIT
SKEPTICAL OF THIS SOLUTION GIVEN THE SEEMINGLY UNFAVORABLE
ENVIRONMENT THAT IS IN PLACE...HOWEVER IT IS INTERESTING THAT ALL
THREE HIGH RESOLUTION MODELS ARE DEPICTING A SIMILAR SCENARIO. AM
THEREFORE HESITANT TO REMOVE POPS GIVEN THIS AGREEMENT. WILL
MAINTAIN SLIGHT CHANCE POPS THROUGH MIDNIGHT WITH LOW-END CHANCE
POPS ACROSS FAR INTERIOR SOUTHEAST GEORGIA...BUT FURTHER
REFINEMENTS MAY BE NEEDED LATER THIS EVENING ONCE SHORT TERM
CONVECTIVE TRENDS BECOME MORE APPARENT. LOWS WILL RANGE FROM THE
LOWER 70S WELL INLAND TO THE UPPER 70S/NEAR 80 AT THE BEACHES.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
I DID NOT MAKE MUCH CHANGE TO THE EARLY WEEK FORECAST AS THE OVERALL
PATTERN IS GOING TO EVOLVE PRETTY MUCH AS EXPECTED. AN UPPER TROF
WILL DIG IN ALOFT OVER THE AREA MONDAY AND TUESDAY...HELPING TO TO
DRAG A SLOW MOVING COLD FRONT INTO THE AREA FROM THE NORTHWEST AND
NORTH. WEAK DISTURBANCES WITHIN THE LONG WAVE TROF...ALONG WITH
DAYTIME TEMPS INTO THE 90S AWAY FROM THE IMMEDIATE COAST...WILL CAUSE
SCATTERED AFTERNOON AND EVENING CONVECTION. THE SURFACE PRESSURE
GRADIENT BETWEEN WEAK HIGH PRESSURE IN THE WESTERN ATLANTIC AND THE
AFTERNOON LEE TROF WILL KEEP WINDS OUT OF THE SOUTHWEST...ACTING TO
RETARD THE INLAND MOVEMENT OF THE SEABREEZE DURING THE AFTERNOON
HOURS. THAT WILL KEEP TEMPS WARM AND GIVE COASTAL AREAS ALMOST AS
MUCH CHANCE OF GETTING CAUGHT BY ONE OF THE LATER DAY
SHOWERS/TSTMS AS THE INTERIOR AREAS.

TUESDAY NIGHT...THE WEAK FRONT PUSHES INTO THE CWA. WITH THE UPPER
LEVEL SUPPORT FOR THE FRONT RIPPING AWAY QUICKLY TO THE
NORTHEAST...MID LEVEL HEIGHTS WILL ACTUALLY BUILD
OVERNIGHT...HELPING TO MAKE THE FRONT GRADUALLY MORE DIFFUSE INTO
WEDNESDAY. THE FRONT MAY HAVE A HARD TIME PUSHING THROUGH THE
GEORGIA COUNTIES...SO I HAVE WARMER TEMPS THERE...WITH ONSHORE WINDS
INCREASING...KEEPING AREAS CLOSER TO THE COAST COOLER THAN DURING
MONDAY AND TUESDAY. THERE COULD ALSO BE SOME STUBBORN LOW CLOUDS AND
FOG DURING WEDNESDAY...KEEPING TEMPS DOWN A LITTLE DUE TO LESS
SUNSHINE. I HAVE NOT YET PUT FOG IN THE FORECAST AS THE DETAILS OF
THE FAVORED LOCATION ARE STILL TOO TOUGH TO PIN DOWN.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
CANADIAN HIGH PRESSURE WILL PREVAIL FOR THE BEGINNING OF THE PERIOD
BUT STEADILY SHIFT EAST WITH A RETURN FLOW SETTING UP ON THE SW
PERIPHERY. MOST AREAS WILL BE DRY WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT. DIURNAL CONVECTION RETURNS TO THE FORECAST FRIDAY THROUGH
SUNDAY AS LOW-LEVEL MOISTURE INCREASES AND ANOTHER UPPER TROUGH SETS
UP SHOP.

&&

.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
TO BE ISSUED.

EXTENDED AVIATION OUTLOOK...DIURNAL CONVECTION POSSIBLE MONDAY AND
TUESDAY. THERE MAY BE SOME FOG AND LOW CIG ISSUES TUESDAY NIGHT
AND WEDNESDAY AS THE FRONT HANGS UP OVER THE AREA.

&&

.MARINE...
TONIGHT...THE PRESSURE GRADIENT WILL GRADUALLY TIGHTEN THROUGH THE
PERIOD WITH THE SHARPENING OF THE INLAND SURFACE TROUGH. THIS WILL
RESULT IN A MODEST SOUTHWEST SURGE. SPEEDS WILL REACH THE 15-20 KT
RANGE...ESPECIALLY ACROSS THE CHARLESTON COUNTY WATERS...BUT ARE
EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS. SEAS WILL
TICK UPWARD A BIT IN RESPONSE TO THE STRONGER WINDS...WITH 4 FT SEAS
GETTING INTO THE SOUTH CAROLINA WATERS LATE TONIGHT.

SOUTHWEST WINDS ON MONDAY MAY VEER SLIGHTLY ONSHORE DURING THE
AFTERNOON...BUT WILL QUICKLY SWITCH BACK TO SOUTHWEST AND INCREASE
DURING THE EVENING AS THE TYPICAL DIURNAL SURGE KICKS IN. I DID
RAISE WINDS A TOUCH DURING MONDAY EVENING...BUT STILL WELL BELOW
ANY SCA CRITERIA. SEAS WILL BE AOB 4 FEET AS WELL. I EXPECT A
SIMILAR SITUATION TUESDAY...ALTHOUGH THE WINDS MAY NOT BE QUITS AS
STRONG TUESDAY EVENING WITH THE GRADIENT STARTING TO RELAX. BY
TUESDAY NIGHT AND WEDNESDAY...THE GRADIENT BECOMES NEARLY NON
EXISTENT WITH WINDS GENERALLY 10 KNOTS OR LESS AND SEAS 2 FEET OR
LESS. I CANT RULE OUT THE POSSIBILITY OF SOME GROUND FOG BLEEDING
INTO THE NEARSHORE WATERS EARLY WEDNESDAY MORNING...BUT ITS TOO
EARLY TO MAKE THAT CALL. HIGH PRESSURE WILL BUILD TO THE NORTH OF
THE AREA FOR LATER IN THE WEEK...VEERING THE WINDS TO EAST AND
SOUTHEAST...BUT NOT PARTICULARLY STRONG.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

ST/ECT







AREA FORECAST DISCUSSION

NWS COLUMBIA SC

 458 PM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE CENTERED OFF THE COAST WILL DIRECT A MOIST SOUTH
FLOW INTO THE FORECAST AREA THROUGH SUNDAY. A COLD FRONT WILL
MOVE INTO THE AREA TUESDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SOME SHOWER AND THUNDERSTORM ACTIVITY OVER OUR CENTRAL FA...WITH
SCATTERED THUNDERSTORMS ACROSS THE WESTERN CAROLINAS ALONG A WEAK
SURFACE TROUGH...DRIFTING SE. QUESTION AS TO HOW FAR SOUTH THIS
ACTIVITY WILL GET. LATEST HRRR APPEARS TO BRING SOME OF IT INTO OUR
NORTHERN FA BY WHILE INDICATING SLOW WEAKENING OF THE ACTIVITY. WILL
MAINTAIN HIGHER POPS NORTHERN FA THROUGH THIS EVENING.

TONIGHT...HIGH-LOW LEVEL MOISTURE AND DRY AIR ALOFT SHOULD RESULT
IN CONSIDERABLE STRATUS AND OR FOG LATE TONIGHT. TEMPERATURES NEAR
MOS CONSENSUS.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
WV LOOP SHOWS RIDGE OF HIGH PRESSURE ANCHORED ACROSS THE FOUR
CORNERS REGION. THE MODELS HINT AT A WEAK CONVERGENCE AREA/TROUGH
ACROSS THE PIEDMONT THAT WILL LINGER ACROSS THE PIEDMONT/MIDLANDS
THROUGH MONDAY. MODEL TIME SECTIONS INDICATE INCREASING MOISTURE
THROUGH THE PERIOD. THERE WILL BE A SERIES OF SHORTWAVES THAT WILL
DEEPEN THE TROUGH ALONG THE EAST COAST THROUGH THE PERIOD. THIS
ALONG WITH THE EXPECTED COLD FRONT ARRIVING INTO THE REGION ON
TUESDAY. MODELS AND ENSEMBLES INDICATE SLIGHT CHANCE/CHANCE POPS
THROUGH MONDAY NIGHT. BEST CHANCE FOR SHOWERS/THUNDERSTORMS
APPEARS TO BE WITH FRONT ON TUESDAY. GUIDANCE NUMBERS SHOWING
QUITE A RANGE FOR DAYTIME HEIGHTS BUT REASONABLY CLOSE. HAVE
STAYED CLOSE TO A CONSENSUS OF THE GUIDANCE WHICH IS CLOSE TO
CLIMATOLOGY FOR HIGHS AND ABOVE CLIMO FOR LOWS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE MODELS SHOW SOME DRYING BEHIND THE FRONT FOR TUESDAY NIGHT
THROUGH THURSDAY BUT THE FRONT DOES APPEAR TO STALL JUST SOUTH
AND EAST OF THE AREA. THE MODELS DISPLAY A MOISTURE INCREASE FOR
FRIDAY AS ANOTHER SHORTWAVE/SURFACE FRONT APPROACHES FROM THE NW.
THE GFS ENSEMBLE MEANS SUPPORT TEMPERATURES NEAR CLIMATOLOGY FOR
TEMPERATURES. POPS DIMINISHING TUESDAY NIGHT BEHIND THE COLD
FRONT. NEXT CHANCE FOR PRECIPITATION APPEARS TO BE FRIDAY AND
SATURDAY.

&&

.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
MAINLY VFR WITH SCATTERED CUMULUS THROUGH THE AFTERNOON AND EVENING.
SCATTERED THUNDERSTORMS OVER THE MIDLANDS AFFECTING CAE/CUB/OGB
THROUGH 23Z. MVFR OR LOWER CONDITIONS DUE TO LOW CEILING AND OR
FOG AFTER 06Z...MORE LIKELY TOWARD 12Z. IMPROVING CONDITIONS TO
VFR BY 15Z. DIURNALLY DRIVEN SCATTERED CONVECTION EXPECTED SUNDAY
AFTERNOON.

EXTENDED AVIATION OUTLOOK...AFTERNOON CONVECTION IS EXPECTED TO
INCREASE IN COVERAGE MON/TUE WITH THE NEXT FRONT MOVING INTO THE
AREA.


&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS GOODLAND KS

 430 PM MDT SUN SEP 1 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 207 PM MDT SUN SEP 1 2013

LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE BEGINNING TO
RETREAT TOWARD THE FOUR CORNERS REGION WITH POSITIVELY TILTED
TROUGH MIGRATING INTO THE NORTHERN GREAT LAKES REGION. STRONG
SUBSIDENCE IS EVIDENT ACROSS THE NORTHERN PLAINS...AND IS
BEGINNING TO OVERSPREAD OUR CWA FROM THE NORTH-NORTHEAST. AT THE
SURFACE HIGH PRESSURE HAS SETTLED OVER OUR CWA WITH COLD FRONT NOW
ALONG FRONT RANGE EXTENDING SOUTH ACROSS TEXAS PANHANDLE.

THERE HAVE BEEN A FEW LIGHT SHOWERS SLOWLY MOVING ACROSS THE
PLAINS OF EASTERN COLORADO AND LATEST RAP/HRRR SHOW THIS ACTIVITY
FALLING APART THROUGH SUNRISE. AT THIS POINT I AM NOT CONFIDENT WE
WILL SEE ANY MEASURABLE PRECIP OUT OF THIS WITH STABLE/DRY AIR
SPREADING WEST...SO I WILL KEEP MENTION OUT THROUGH THE REMAINDER
OF THE AFTERNOON. WITH STABLE AIR MASS IN PLACE AND SUBSIDENCE
BUILDING IN ALOFT...I AM ANTICIPATING DRY CONDITIONS THROUGH
MONDAY.

REGARDING TEMPS...COOLER AIR MASS REMAINS IN PLACE OVERNIGHT...AND
WITH LOW TD VALUES (45-50F) ADVECTING SOUTH THROUGH THIS EVENING
AND CLEAR/CALM CONDITIONS WE SHOULD SEE VERY GOOD RADIATIONAL
COOLING. I TRIMMED TEMPS A LITTLE WITH LOWS AT SOME LOCATIONS IN
THE LOW 50S. H5 RIDGE WILL BEGIN TO BUILD BACK TO THE EAST MONDAY
AND LEE TROUGH WILL BEGIN TO STRENGTHEN. WE SHOULD SEE WAA ALOFT
WITH UNIDIRECTIONAL SOUTHERLY FLOW...AND HIGHS ABOUT 3-4F WARMER
THAN TODAY (UPPER 80S/NEAR 90F).

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 221 PM MDT SUN SEP 1 2013

FROM MONDAY NIGHT THROUGH SATURDAY...THE UPPER HIGH PRESSURE
CENTER REMAINS OVER THE CENTRAL ROCKIES AND CENTRAL HIGH PLAINS
REGIONS. BY NEXT SUNDAY...THE UPPER LOW CENTER THAT HAS BEEN SLOWLY
MOVING INTO THE PACIFIC NORTHWEST MOVES ACROSS THE NORTHERN
ROCKIES AND NORTHERN HIGH PLAINS...PUSHING THE UPPER TROUGH AXIS
FURTHER EAST OVER THE PLAINS AND WESTERN GREAT LAKES
REGIONS AND TURNING THE FLOW ALOFT TO THE SOUTHWEST ACROSS THE
FORECAST AREA.

THE SURFACE HIGH PRESSURE AREA IN PLACE OVER THE PLAINS STATES
MOVES FURTHER TO THE EAST AS THE SURFACE TROUGH MOVES INTO
POSITION NEAR THE EASTERN COLORADO BORDER BY WEDNESDAY MORNING. A
WEAK SURFACE TROUGH REMAINS NEARLY STATIONARY OVER THE EASTERN
COLORADO BORDER THROUGH SUNDAY WITH MAINLY WESTERLY FLOW ALOFT
OVER THE ROCKIES. DURING THIS TIME...ISOLATED SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN TO THE WEST EACH
AFTERNOON WITH A STRAY STORM OR TWO MOVING INTO THE WESTERN
PORTION OF THE FORECAST AREA LATE EACH DAY. OTHERWISE...HAVE KEPT
THE EXTENDED FORECAST PERIOD DRY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 430 PM MDT SUN SEP 1 2013

FOR KGLD AND KMCK VFR THROUGH THE PERIOD. SFC HIGH TO MOVE IN
TONIGHT PROVIDING FOR LIGHT/VARIABLE WINDS. PRESSURE GRADIENT
INCREASES DURING THE DAY MONDAY LEADING TO SOUTHERLY WINDS GUSTING
NEAR 25KTS AT KGLD BY 17Z AND CONTINUING THROUGH THE REST OF THE
TAF PERIOD. FOR KMCK SOUTH/SOUTHEAST WIND AROUND 10KTS EXPECTED BY
16Z AND CONTINUING THROUGH THE REST OF THE TAF PERIOD.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...99







AREA FORECAST DISCUSSION

NWS GOODLAND KS

 210 PM MDT SAT AUG 31 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 150 PM MDT SAT AUG 31 2013

LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW WEAKENED H5 RIDGE
EXTENDING ACROSS THE SW HALF OF THE CWA WITH WEST TO NORTHWEST FLOW
BEGINNING TO SHIFT SOUTH INTO SOUTHERN WYOMING AND MOST OF NEBRASKA.
A STRONG SHORTWAVE TROUGH HAS KICKED A COLD FRONT SOUTH TO THE NE
PANHANDLE. AHEAD OF THIS FEATURE WEAK MID LEVEL FRONTOGENETICAL
FORCING COMBINED WITH AN EXITING SHORTWAVE TROUGH OVER EASTERN
NEBRASKA LED TO LIGHT SHOWER/ISOLATED THUNDERSTORM DEVELOPMENT THIS
MORNING. LATEST RADAR TRENDS SHOW THIS ACTIVITY LINGERING OVER THE
CWA...WITH ADDITIONAL ACTIVITY DEVELOPING UPSTREAM OVER THE HIGHER
TERRAIN IN CENTRAL COLORADO AHEAD OF A WEAKER SHORTWAVE TROUGH OVER
EASTERN WYOMING.

AS THE SHORTWAVE TROUGH OVER WYOMING DROPS SOUTH TONIGHT IT WILL
HELP PUSH THE COLD FRONT SOUTH INTO NW KANSAS...WITH LARGE SCALE
FORCING OVERSPREADING OUR CWA. EARLY AFTERNOON SHOWER/THUNDERSTORM
ACTIVITY SHOULD INCREASE IN COVERAGE THROUGH 00Z IN RESPONSE TO THE
INCREASE IN LARGE SCALE SUPPORT AND FURTHER DESTABILIZATION. PWATS
REMAIN VERY HIGH THROUGH SUNDAY MORNING (1.3-1.5) SO THERE IS PLENTY
OF MOISTURE TO WORK WITH DURING THIS EVENT. AS SHORTWAVE DROPS SOUTH
THERE SHOULD BE AN INCREASE IN COVERAGE BEFORE SUBSIDENCE QUICKLY
MOVES IN FROM THE NORTH AFTER MIDNIGHT. MODELS DO SHOW COLD POOL
LINGERING IMMEDIATELY BEHIND COLD FRONT OVER OUR SOUTHERN CWA
THROUGH SUNDAY MORNING. THIS COLD POOL MAY ACTUALLY LINGER INTO THE
AFTERNOON...WHICH COULD HELP LEAD TO DIURNAL SHOWER/THUNDERSTORM
DEVELOPMENT BEFORE 00Z IN OUR SOUTH...SO I KEPT THUNDERSTORM MENTION
FOR THESE LOCATIONS.  BASED ON LATEST HRRR/RUC...I AM STILL UNSURE
ABOUT WHERE BEST COVERAGE WILL DEVELOP...HOWEVER ONGOING 40 POPS
SEEMED REASONABLE RIGHT. INSTABILITY MAY BE MARGINAL ACROSS MUCH OF
OUR CWA THROUGH TONIGHT...SO WE ARE PROBABLY ONLY LOOKING AT AN
ISOLATED SEVERE THUNDERSTORM THREAT.  WITH VERY MOIST AIR MASS AND
SLOW STORM MOTIONS I COULDNT HEAVY RAINFALL WITH ANY THUNDERSTORM
ACTIVITY. HOWEVER...IM NOT SURE ABOUT HOW WIDESPREAD THAT THREAT
WILL REALLY BE. WE MAY JUST END UP WITH A GOOD THREAT OF LIGHT
RAIN...WITH A FEW ISOLATED POCKETS OF MODERATE-HEAVY RAINFALL.

REGARDING TEMPS...WITH CLEARING SKIES IN THE NORTH TEMPS HAVE
FINALLY BEGUN TO WARM ACROSS MUCH OF THE CWA...HOWEVER A DOWNWARD
ADJUSTMENT WAS NEEDED TO CATCH CURRENT TRENDS THIS AFTERNOON. AFTER
THE COLD FRONT PUSHES SOUTH TONIGHT A MUCH MORE SEASONABLE AIR MASS
WILL SETTLE OVER OUR CWA. HIGH ARE CURRENTLY PROGGED TO BE IN THE
MID-UPPER 80S SUNDAY...WHICH IS RIGHT ABOUT WHERE WE WOULD EXPECT TO
BE FOR LABOR DAY WEEKEND.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 204 PM MDT SAT AUG 31 2013

THE UPPER RIDGE IS IN PLACE AGAIN OVER THE ROCKIES AND HIGH PLAINS
FROM SUNDAY NIGHT THROUGH ALL OF NEXT WEEK. DIFFERENCES BEGIN TO
SHOW UP IN MODEL PROGRESSIONS OF THE UPPER LOW CENTER RIDING UP
OVER THE RIDGE IN THE PACIFIC NORTHWEST AND THE OVERALL FLATTENING
OF THE RIDGE IN THE FRIDAY NIGHT THROUGH SATURDAY TIME PERIOD.

SURFACE COOLER HIGH PRESSURE AREA STAYS MOSTLY OVER THE CENTRAL
PLAINS AND CENTRAL HIGH PLAINS SUNDAY NIGHT AND MONDAY BEFORE
PUSHING FURTHER EAST WITH A DEEPENING LEE TROUGH THAT PERSISTS IN
THE VICINITY OF THE EASTERN COLORADO BORDER. WITH SOUTHERLY FLOW
ACROSS THE FORECAST AREA...EXPECT MORE DRY AND WARM CONDITIONS
THROUGH THE UPCOMING WORK WEEK AND NEXT WEEKEND WITH HIGHS IN THE
90S AND LOWS IN THE 60S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1130 AM MDT SAT AUG 31 2013

VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. PRIMARY AVIATION CONCERN IS POTENTIAL FOR
SHOWERS/THUNDERSTORMS AT BOTH TERMINALS THIS AFTERNOON/EVENING
WITH COLD FRONT PASSAGE. I LEFT VCTS GROUP IN PLACE AND ADJUSTED
TIMING TO ACCOUNT FOR ACTIVITY INCREASING IN COVERAGE AT KGLD
FIRST AND THEN TRENDING SOUTH DURING THE EVENING. WINDS WILL
GENERALLY BE LESS THAN 10KT AT BOTH TERMINALS WITH FRONT JUST
NORTHEAST...HOWEVER AS THE FRONT MOVES SOUTH TONIGHT WINDS WILL
INCREASE OUT OF THE NORTHEAST WITH GUSTS TO 20KT POSSIBLE THROUGH
SUN MORNING.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...DR







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 301 PM CDT Sat Aug 31 2013

...UPDATED SHORT TERM...

.SYNOPSIS...
ISSUED AT 300 PM CDT SAT AUG 31 2013

An upper level center of high pressure was located across New Mexico
and the extreme southern High Plains today, as the upper westerly
jet was positioned zonally across the northern Rockies and Northern
Plains. A shortwave was in place across southern Canada, on the
north side of the jet. A hot airmass still encompassed the central
part of the country. 850 mb level temperatures in excess of 20
degrees C extended from the entire great plains region eastward to
the the Ohio valley. at the surface...a cold front was moving
southward across western South Dakota and extreme western Nebraska.
Another weak stationary front was positioned from the Texas
panhandle northeast into south central Kansas. Easterly surface
winds became more southerly across western Kansas as surface low
pressure slowly filled across the oklahoma panhandle and temperatures
warmed into the 90`s by early afternoon.

&&

.SHORT TERM...(This evening through Sunday)
ISSUED AT 300 PM CDT SAT AUG 31 2013

The immediate concern will revolve around convective chances which
are not great, but non-zero as well. The best location appears along
the diffuse boundary across south central Kansas. The HRRR runs have
somewhat approximated isolated convection occurring by about 23 utc.
A lack of upper winds and lack of shear suggest little chances at
all of severe thunderstorms, and storms  should have short life
cycles. A better chance for showers and thunderstorms exists well
into the overnight as the Northern Plains cold front enters the
area. Probabilities increase from north to south around 6z and
after.

Very warm temperatures will continue into this evening. The NAM
models surface temperatures sill around 100 degrees this evening
near the oklahoma line and low 80s persisting after midnight.
Morning lows will likely be warm across all of southwest Kansas,
with a few locations having lows in the upper 70s, however rain
cooled air form a few vigorous storm cluster might augment the
temperatures locally.

Thunderstorms chances are again in the forecast during the afternoon
Sunday as redevelopment is likely along the frontal boundary,
wherever it decides to stall out.


.LONG TERM...(Sunday night through Saturday)
ISSUED AT 235 PM CDT SAT AUG 31 2013

A cold front will move across Kansas tonight as a vigorous upper
level trough moves from southeast Saskatchewan to the Great Lakes,
and a brief period of near climatological temperatures should extend
into Monday. However, the anticyclone centered over the Rockies will
build back into the Central Plains early next week, and several days
of warm, quiet weather will follow. Unless rainfall tonight is more
widespread than appears likely, vegetation will become increasingly
drought stressed next week. Reduced evapotranspiration may allow
more solar radiation to covert into sensible heat, and temperatures
in the mid to upper 90s can be expected on most days.

Tropical thunderstorm activity has been strongly suppressed from
about 130E to the dateline, although an area of enhanced
thunderstorms has been persistent in the Indian Ocean southwest of
India. Most of the numerical models suggest that a coherent tropical
cluster that projects onto a Madden Julian Oscillation (MJO) will
amplify in Phase 1 of the Wheeler-Hendon Phase Space Diagram early
in September and propagate slowly east before losing identity in the
Indian Ocean. There is little correlation between the MJO and
sensible weather in the central plains at this time of the year, but
there may be in increased chance for tropical waves to come off
Africa into the eastern Atlantic next week.

Global relative angular momentum remains below climatology, but
mountain torque has increased in recent days. The atmosphere will be
best represented by Phase 4-5 of the Weickmann-Berry Global Wind
Oscillation, which correlates with anticyclonic flow in the western
and central United States. The deterministic model solutions all
favor ridging from the central Rockies across the central and
southern United States through the first ten days of September with
only minor synoptic scale differences. The 12Z GFS has trended
toward the 00Z ECMWF in handling the closed cyclone near 140W that
wallows into the northern plains 9-10 September and largely was
followed for grid adjustments, although confidence in behavior of
this cyclone is low.

Upslope flow into the foothills in eastern Colorado Sunday evening
should favor thunderstorm development, but the upper level flow will
be light and largely meridional over western Kansas. Most of the
thunderstorms will remain west of the Colorado border, but there is
a nonzero chance that a thunderstorm could reach far southwest
Kansas before midnight Sunday night. Cool high pressure with light
winds and low level dewpoints in the 50s will allow for strong
radiational cooling, and lows will drop into the upper 50s in most
areas Tuesday morning. Another minor trough dropping into the mean
long wave trough near 80W will support a weak boundary that may
survive into northern Kansas Wednesday night, but limited
instability and weak flow aloft do not favor an organized
thunderstorm event. As the upper level trough near 140W moves across
the Northern Plains around 9 September, a cold front will move into
Kansas and provide another opportunity for thunderstorm development
and a return to more seasonal temperatures.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 106 PM CDT SAT AUG 31 2013

A widespread scattered to broken field of altocumulus was present
over western Kansas and will continue to dissipate through the
afternoon. As surface temperatures rise toward the convective
temperature, isolated thunderstorms may develop around 22-23 utc.
The better chance for thunderstorms impacting the local terminals
will come later tonight as a cold front moves southward from the
dakotas. Although confidence is not particularly high, tempo
groups have been added to terminals for -TSRA after 6 UTC. With
weak steering flow in low surface based capes, the storm may decay
rapidly buy redevelop early Sunday afternoon along any surface
outflow of the synoptic front.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  69  88  60  89 /  20  20  10   0
GCK  68  88  58  90 /  30  20  10   0
EHA  69  88  64  91 /  20  20  10  10
LBL  70  88  60  92 /  20  20  10   0
HYS  69  88  57  90 /  40  20   0   0
P28  72  95  64  90 /  10  20  10   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Ruthi
AVIATION...Russell







AREA FORECAST DISCUSSION

NWS GOODLAND KS

 151 PM MDT SAT AUG 31 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 150 PM MDT SAT AUG 31 2013

LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW WEAKENED H5 RIDGE
EXTENDING ACROSS THE SW HALF OF THE CWA WITH WEST TO NORTHWEST FLOW
BEGINNING TO SHIFT SOUTH INTO SOUTHERN WYOMING AND MOST OF NEBRASKA.
A STRONG SHORTWAVE TROUGH HAS KICKED A COLD FRONT SOUTH TO THE NE
PANHANDLE. AHEAD OF THIS FEATURE WEAK MID LEVEL FRONTOGENETICAL
FORCING COMBINED WITH AN EXITING SHORTWAVE TROUGH OVER EASTERN
NEBRASKA LED TO LIGHT SHOWER/ISOLATED THUNDERSTORM DEVELOPMENT THIS
MORNING. LATEST RADAR TRENDS SHOW THIS ACTIVITY LINGERING OVER THE
CWA...WITH ADDITIONAL ACTIVITY DEVELOPING UPSTREAM OVER THE HIGHER
TERRAIN IN CENTRAL COLORADO AHEAD OF A WEAKER SHORTWAVE TROUGH OVER
EASTERN WYOMING.

AS THE SHORTWAVE TROUGH OVER WYOMING DROPS SOUTH TONIGHT IT WILL
HELP PUSH THE COLD FRONT SOUTH INTO NW KANSAS...WITH LARGE SCALE
FORCING OVERSPREADING OUR CWA. EARLY AFTERNOON SHOWER/THUNDERSTORM
ACTIVITY SHOULD INCREASE IN COVERAGE THROUGH 00Z IN RESPONSE TO THE
INCREASE IN LARGE SCALE SUPPORT AND FURTHER DESTABILIZATION. PWATS
REMAIN VERY HIGH THROUGH SUNDAY MORNING (1.3-1.5) SO THERE IS PLENTY
OF MOISTURE TO WORK WITH DURING THIS EVENT. AS SHORTWAVE DROPS SOUTH
THERE SHOULD BE AN INCREASE IN COVERAGE BEFORE SUBSIDENCE QUICKLY
MOVES IN FROM THE NORTH AFTER MIDNIGHT. MODELS DO SHOW COLD POOL
LINGERING IMMEDIATELY BEHIND COLD FRONT OVER OUR SOUTHERN CWA
THROUGH SUNDAY MORNING. THIS COLD POOL MAY ACTUALLY LINGER INTO THE
AFTERNOON...WHICH COULD HELP LEAD TO DIURNAL SHOWER/THUNDERSTORM
DEVELOPMENT BEFORE 00Z IN OUR SOUTH...SO I KEPT THUNDERSTORM MENTION
FOR THESE LOCATIONS.  BASED ON LATEST HRRR/RUC...I AM STILL UNSURE
ABOUT WHERE BEST COVERAGE WILL DEVELOP...HOWEVER ONGOING 40 POPS
SEEMED REASONABLE RIGHT. INSTABILITY MAY BE MARGINAL ACROSS MUCH OF
OUR CWA THROUGH TONIGHT...SO WE ARE PROBABLY ONLY LOOKING AT AN
ISOLATED SEVERE THUNDERSTORM THREAT.  WITH VERY MOIST AIR MASS AND
SLOW STORM MOTIONS I COULDNT HEAVY RAINFALL WITH ANY THUNDERSTORM
ACTIVITY. HOWEVER...IM NOT SURE ABOUT HOW WIDESPREAD THAT THREAT
WILL REALLY BE. WE MAY JUST END UP WITH A GOOD THREAT OF LIGHT
RAIN...WITH A FEW ISOLATED POCKETS OF MODERATE-HEAVY RAINFALL.

REGARDING TEMPS...WITH CLEARING SKIES IN THE NORTH TEMPS HAVE
FINALLY BEGUN TO WARM ACROSS MUCH OF THE CWA...HOWEVER A DOWNWARD
ADJUSTMENT WAS NEEDED TO CATCH CURRENT TRENDS THIS AFTERNOON. AFTER
THE COLD FRONT PUSHES SOUTH TONIGHT A MUCH MORE SEASONABLE AIR MASS
WILL SETTLE OVER OUR CWA. HIGH ARE CURRENTLY PROGGED TO BE IN THE
MID-UPPER 80S SUNDAY...WHICH IS RIGHT ABOUT WHERE WE WOULD EXPECT TO
BE FOR LABOR DAY WEEKEND.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 211 AM MDT SAT AUG 31 2013

UPPER LEVEL BLOCKING PATTERN WILL CONTINUE OVER THE HIGH PLAINS FOR
THE EXTENDED FORECAST PERIOD...WHICH WILL KEEP WARM AND DRY
CONDITIONS OVER THE FORECAST AREA. THE 500 MB HIGH PRESSURE AREA
WILL BE CENTERED OVER COLORADO FOR TUESDAY AS RIDGE BECOMES MORE
AMPLIFIED INTO THE NORTHERN HIGH PLAINS. ZONAL FLOW WILL BEGIN TO
ENTER THE CENTRAL PLAINS FOR NEXT WEEKEND AS AN UPPER LEVEL LOW
MOVES OUT OF ALBERTA AND ACROSS THE NORTHERN PLAINS. SHORTWAVE
TROUGHS COULD DEVELOP AND MOVE THROUGH THE TRI STATE AREA SATURDAY
AND SUNDAY AS UPPER LEVEL HEIGHTS INCREASE AND RIDGE OF HIGH
PRESSURE BEGINS TO WEAKEN OVER THE SOUTHWEST REGION.

STRONG WARM AIR ADVECTION WILL CONTINUE AT THE SURFACE THROUGH THE
EXTENDED PERIOD...KEEPING SURFACE TEMPERATURES ABOVE AVERAGE IN THE
LOWER 90S. MODEL SOUNDINGS SHOW STABLE UPPER AIR PROFILE THROUGH THE
PERIOD...WITH A LACK OF INSTABILITY PARAMETERS AND AVAILABLE
MOISTURE.  SURFACE TEMPERATURES COULD POSSIBLY REACH THE CONVECTIVE
TEMPERATURES...WHICH ARE FORECASTED TO BE IN THE MID TO UPPER 90S.
STRONG CAP COULD BE BROKEN FOR ISOLATED LOCATIONS ALLOWING FOR SOME
SMALL AREAS OF STORM DEVELOPMENT.  CHANCES FOR PRECIPITATION ARE
VERY SLIM...WITH WARM AND DRY TREND CONTINUING INTO NEXT WEEKEND.
THE BEST CHANCE TO SEE PRECIPITATION ACROSS THE TRI STATE AREA WOULD
BE FOR NEXT WEEKEND AS UPPER LEVEL PATTERN BEGINS TO LOOK SUPPORTIVE
FOR STORM DEVELOPMENT...BUT MODEL RUNS STILL INDICATE DRY WEATHER AT
PRESENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1130 AM MDT SAT AUG 31 2013

VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. PRIMARY AVIATION CONCERN IS POTENTIAL FOR
SHOWERS/THUNDERSTORMS AT BOTH TERMINALS THIS AFTERNOON/EVENING
WITH COLD FRONT PASSAGE. I LEFT VCTS GROUP IN PLACE AND ADJUSTED
TIMING TO ACCOUNT FOR ACTIVITY INCREASING IN COVERAGE AT KGLD
FIRST AND THEN TRENDING SOUTH DURING THE EVENING. WINDS WILL
GENERALLY BE LESS THAN 10KT AT BOTH TERMINALS WITH FRONT JUST
NORTHEAST...HOWEVER AS THE FRONT MOVES SOUTH TONIGHT WINDS WILL
INCREASE OUT OF THE NORTHEAST WITH GUSTS TO 20KT POSSIBLE THROUGH
SUN MORNING.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...DR
LONG TERM...MK
AVIATION...DR







AREA FORECAST DISCUSSION

NWS WICHITA KS

 1247 PM CDT SAT AUG 31 2013

UPDATED 18Z/AVIATION SECTION.

.UPDATE...
ISSUED AT 1141 AM CDT SAT AUG 31 2013

OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION IN NEB PUSHED ACROSS MOST
OF THE FORECAST AREA THIS MORNING...CURRENTLY WASHING OUT ALONG
HIGHWAY 54. CLOUD DEBRIS AND SOME HIGHER SFC DEWPOINTS PUSHED ACROSS
NE SECTIONS OF THE FORECAST AREA EARLY TODAY....WHICH  HAD LED TO
SOME HIGHER SBCAPE VALUES ALONG OR JUST TO THE NORTH OF THIS REMNANT
BOUNDARY.  NOT ALOT OF CONVERGENCE NOTED ALONG THIS BOUNDARY...SO
THINK CHANCES OF AN ISOLATED STORM DEVELOPING IN THIS UNSTABLE AIR
ARE SLIM.  LATEST HIGH RES HRRR REFLECTIVITY MODEL SHOWS AN ISOLATED
STORM TRYING TO DEVELOP NEAR KEMP LATE THIS AFTERNOON. BUT THINK
THIS CHANCE IS TOO REMOTE FOR NOW TO MENTION IN THE GRIDS/ZONES.

THE MAIN CONCERN WILL BE THE HIGHER SFC DEWPOINTS STILL LOCATED
ACROSS CEN KS...ALONG I-70...WITH SOME CONCERN THAT THIS HIGHER
DEWPOINT AIR MAY REMAIN IN THE UPPER 60S THIS AFTERNOON.  WITH
CLOUDS CLEARING OUT...THINK THAT SFC TEMPS WILL WARM TO NEAR THE
CENTURY MARK THIS AFTERNOON IN THIS AREA. SO WITH UPPER 60S
DWPTS...THIS GIVES HEAT INDEX VALUES IN THE 104-108 RANGE.  SO THINK
THIS AREA MAY ALSO REACH DANGEROUS HEAT INDICE VALUE THAT WOULD
WARRANT AN EXPANSION OF THE HEAT ADVISORY ALONG I-70. ALSO THINK
THAT CURRENT HEAT ADVISORY OVER SE KS LOOKS FINE AS WELL...GIVEN SFC
DEWPOINTS WILL STAY HIGH IN THIS AREA AS WELL.

KETCHAM

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 300 AM CDT SAT AUG 31 2013

CONVECTION CONTINUES EARLY THIS MORNING FROM NORTHWEST KS TO SOUTH-
CENTRAL NEBRASKA ALONG AND BEHIND AN OUTFLOW BOUNDARY. WEAK
SOUTH-SOUTHWESTERLY WIND AT 850 MB OVERTOP OF THE OUTFLOW BOUNDARY
MAY SUSTAIN THIS ACTIVITY INTO EARLY THIS MORNING. THINK MOST OF IT
WILL STAY JUST NORTH/NORTHWEST OF OUR AREA...BUT WILL INCLUDE A
SLIGHT CHANCE POP BY RUSSELL/GREAT BEND/LINCOLN. CONVECTIVE DEBRIS
CLOUDINESS WILL LIKELY MOVE SOUTHEAST INTO CENTRAL KS THIS MORNING.
IF IT THINS OUT...THICKNESSES SUGGEST SIMILAR HIGHS TO YESTERDAY
AFTERNOON SO HAVE MAINTAINED FORECAST HIGHS OF 99-103. WITH VERY
LIGHT SOUTH WINDS...SOUTHEAST KS WILL PROBABLY BE ABLE TO MAINTAIN
DEWPOINTS AROUND 70 DEGREES INTO THIS AFTERNOON. THIS WILL PUT THEM
INTO HEAT ADVISORY CRITERIA WITH HEAT INDICES REACHING 104-107.
PLANNING A HEAT ADVISORY FROM 17Z-01Z THERE.

A SHORTWAVE TROUGH PRESENTLY OVER ALBERTA/SASKATCHEWAN WILL AMPLIFY
AS IT TRACKS EAST-SOUTHEASTWARD TO THE WESTERN GREAT LAKES BY SUNDAY
AFTERNOON. THE ASSOCIATED COLD FRONT IS STILL SLATED TO MOVE
SOUTHWARD THROUGH OUR AREA VERY LATE TONIGHT THROUGH SUNDAY.
LARGE-SCALE FORCING IS ON THE WEAK SIDE...ALTHOUGH A DECENT
PRECIPITABLE WATER AXIS (AROUND 1.5 INCHES) WILL ACCOMPANY THE
FRONTAL PASSAGE. WIDELY SEPARATED SHOWERS/STORMS WILL BE POSSIBLE
WITH THE FRONT MOVING THROUGH...ALTHOUGH NOT EXPECTING A
WIDESPREAD SOAKING RAIN EVENT. PLACES LUCKY ENOUGH TO RECEIVE RAIN
WILL PROBABLY GET 0.25 INCH OR LESS. COOLER AIR WILL SPREAD IN
BEHIND THE FRONT...FIRST FELT IN CENTRAL KS SUNDAY...AND AREA-WIDE
SUNDAY NIGHT INTO MONDAY.

JMC

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM CDT SAT AUG 31 2013

THE RESILIENT UPPER HIGH CENTER WILL RE-STRENGTHEN OVER THE
CENTRAL ROCKIES/HIGH PLAINS TOWARD MID-LATE WEEK WITH LEE TROUGH
DEVELOPMENT IN THE LOW-LEVELS. TEMPERATURES ARE EXPECTED TO WARM
TO ABOUT 5-9 DEGREES ABOVE NORMAL BY THE END OF THE WEEK. RECENT
RUNS OF THE ECMWF HAVE COME AROUND TOWARD THE GFS WITH THIS
SCENARIO...INCREASING FORECAST CONFIDENCE. UNFORTUNATELY...RAIN
CHANCES LOOK NIL.

JMC

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1246 PM CDT SAT AUG 31 2013

VFR CONDITIONS ARE EXPECTED ACROSS THE AREA FOR THE NEXT 24 HOURS.
THE MAIN CONCERN WILL INCREASING MID CLOUDS LATE TONIGHT ACROSS CEN
KS AS CONVECTIVE DEBRIS FROM EXPECTED CONVECTION IN WRN KS DRIFTS
EAST LATE TONIGHT OR EARLY ON SUN. AS THE MID CLOUDS INCREASE...ALSO
WILL SEE A COLD FRONT DROP SOUTH OUT OF NEB EARLY ON SUN MORNING...
WHICH WILL LEAD TO A WIND SHIFT TO THE NORTH FOR CEN KS BY AROUND
12Z/SUN.  LIFT ALONG THIS BOUNDARY MAY ALSO LEAD SOME ELEVATED
SHOWERS AND A FEW RUMBLES OF THUNDER FOR CEN KS...SO WILL ADD A VCTS
MENTION FOR CEN KS AROUND 12Z/SUN.

FRONTAL BOUNDARY WILL CONTINUE TO DROP SOUTH SUN MORNING...SHIFTING
THE WINDS TO THE NORTH AT KHUT AND KICT BY AROUND 14-15Z/SUN.

KETCHAM

&&

.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT   102  73  93  66 /  10  20  20  10
HUTCHINSON     102  72  92  65 /  10  20  20  10
NEWTON         101  73  92  65 /  10  20  20  10
ELDORADO       101  74  93  66 /  10  20  20  10
WINFIELD-KWLD  101  73  96  68 /  10  10  20  10
RUSSELL        101  70  89  62 /  20  30  20  10
GREAT BEND     102  70  89  63 /  10  20  20  10
SALINA         101  72  90  63 /  10  30  20  10
MCPHERSON      101  72  91  64 /  10  20  20  10
COFFEYVILLE     99  73  96  68 /   0  10  20  10
CHANUTE         99  72  93  64 /  10  10  30  10
IOLA            99  74  93  64 /  10  20  30  10
PARSONS-KPPF    99  73  95  66 /   0  10  30  10

&&

.ICT WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ033-048-049-
051>053-069>072-094>096-098>100.

&&

$$








AREA FORECAST DISCUSSION

NWS GOODLAND KS

 1130 AM MDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 852 AM MDT SAT AUG 31 2013

MAIN CHANGE WAS TO ADD MENTION OF THUNDERSTORMS TO FORECAST FOR
THE MORNING PERIOD. RADAR HAS BEEN SHOWING 20-35 DBZ RETURNS
ACROSS MUCH OF THE AREA THIS MORNING...HOWEVER THIS IS MAINLY
VIRGA. RECENT RETURNS HOWEVER HAVE SHOWN BRIEF/ISOLATED CORES OVER
40-45DBZ...WHICH WOULD PROBABLY BE ENOUGH FOR MEASURABLE PRECIP
IN THE CURRENT ENVIRONMENT. WITH SHORTWAVE STILL OVER CENTRAL
NEBRASKA (HIGHLIGHTED BY STRONG PV HEIGHT ANOMALY ON RAP ANALYSIS)
AND STALLED FRONT ALONG THE KS/NE BORDER WE COULD CONTINUE TO SEE
THIS ISOLATED ACTIVITY THROUGH MIDDAY. MODELS SHOW A GENERAL
CLEARING TREND THROUGH NOON BEFORE ACTIVITY BEGINS REDEVELOPING IN
THE WEST...SO I ONLY ADJUSTED TIMING OF CLOUD COVER AND MORNING
POPS. I WILL HAVE TO MONITOR WHAT IMPACT CLOUDS WILL HAVE ON
HIGHS TODAY IF THEY CONTINUE TO LINGER.

&&

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 346 AM MDT SAT AUG 31 2013

MAIN FORECAST PROBLEM WILL BE PRECIPITATION THROUGH THE WEEKEND...
HOW HOT TO MAKE TODAY...AND HOW MUCH TO COOL DOWN TEMPERATURES
SUNDAY. SATELLITE SHOWING AN AMPLIFIED FLOW OVER THE EASTERN PACIFIC
WITH A FLATTER FLOW OVER THE COUNTRY. MID/UPPER LEVEL RIDGE THAT HAS
PERSISTED FOR A WHILE HAS BEEN FLATTENED AND PUSHED SOUTH BY
SHORTWAVES GOING ACROSS THE TOP OF IT. LOOKS LIKE WE HAVE A BETTER
SUBTROPICAL MOISTURE CONNECTION ACROSS THAN 24 HOURS AGO.

COMPLICATED SURFACE PATTERN WITH A FRONT THAT HAS SAGGED INTO THE
NORTHERN PORTION OF THE AREA. COMBINATION OF THIS BOUNDARY...WEAK
SHORTWAVE TROUGH...AND RIGHT REAR QUADRANT OF THE JET BROUGHT
THUNDERSTORMS TO THE NORTHERN HALF OF THE AREA WITH THE GREATEST
CONCENTRATION NEAR THE KANSAS AND NEBRASKA BORDER. THESE STORMS HAVE
THROWN OUT NUMEROUS OUTFLOW BOUNDARIES.

AT JET LEVEL...MODELS WERE HAVING A LITTLE TROUBLE WITH THE JET
SEGMENT JUST TO OUR NORTH. THEY DID NOT HAVE THE STRONGER WINDS FAR
ENOUGH SOUTH. HERE THE NAM WAS DOING A LITTLE BETTER THAN UKMET...
GFS..AND CANADIAN. AT MID LEVELS...THE CANADIAN AND UKMET WERE
DOING A LITTLE BETTER THAN THE GFS. OUTSIDE OF THE MESOSCALE
INFLUENCES THE CANADIAN WAS DOING THE BEST ON THE LOW LEVEL WIND
AND PRESSURE FIELD. THE GFS WAS DOING A LITTLE BETTER THAN THE
CANADIAN AND SREF ON THE LOW LEVEL THERMAL FIELD.

TODAY/TONIGHT...WEAK RIGHT REAR QUADRANT IS AFFECTING THE AREA NOW
AND IT MAY STILL BE NEAR OR OVER THE NORTHERN PORTION OF THE AREA AT
12Z. THIS WEAKENS OR PULLS AWAY FROM THE AREA AS STRONGER JET
DEVELOPS TO OUR NORTH WITH THE RIGHT FRONT QUADRANT AFFECTING THE
AREA IN THE AFTERNOON. INITIAL SHORTWAVE TROUGH ALSO LOOKS LIKE IT
MOVES EAST OF THE AREA THIS MORNING. BASED ON WHERE CURRENT
THUNDERSTORMS ARE OCCURRING BELIEVE THOSE STORMS SHOULD BE OUT OF
THE AREA BY 12Z. IT IS POSSIBLE THAT THERE MAY BE SOME
THUNDERSTORMS IN THE EAST EARLY. WILL MONITOR AS LONG AS POSSIBLE
BEFORE MAKING THE FINAL DECISION.

HOW MUCH DO CLOUDS HANG AROUND AND OVERNIGHT OUTFLOW BOUNDARIES WILL
AFFECT ALL PARAMETERS OF THE FORECAST. DAY SHIFT WILL HAVE TO PIN
WHERE OUTFLOW BOUNDARIES END UP AND MAY NEED TO ADJUST THE AREA OF
PRECIPITATION. TREND FOR THE INCOMING FRONT AND MID/UPPER LEVEL
SUPPORT HAS BEEN TO BE SLOWER. SO MADE ADJUSTMENTS TO THE
PRECIPITATION GRIDS TO REFLECT THIS. IF MESOSCALE DOES NOT CHANGE
THINGS...THEN EXPECT PRECIPITATION TO DEVELOP IN THE NORTHWEST HALF
IN THE AFTERNOON AND CONTINUE SOUTH AND EAST ACROSS THE AREA INTO
THE OVERNIGHT HOURS.

THIS INITIAL ROUND OF PRECIPITATION WILL BE TIED TO FRONT AND
SHORTWAVE TROUGH. THEN THE ABOVE MENTIONED JET LOOKS TO STAY NORTH OF
THE AREA THROUGH THE EVENING BEFORE COMING SOUTH AFTER 06Z. MOST OF
THE NORTHERN HALF LOOKS TO BE IN THE RIGHT REAR QUADRANT BY 12Z. THIS
IS FURTHER NORTH AT THIS TIME THAN WHAT THE MODELS WERE SHOWING
YESTERDAY. SO EXPECT SOME REDEVELOPMENT FURTHER NORTH BEHIND THE
FRONT.

IF CLOUDS HANG AROUND LONGER...WHICH RIGHT NOW THEY LOOK LIKE THEY
ARE THINNING...AND THE AIR MASS RECOVERS THE OVERNIGHT CONVECTION...
HOT TEMPERATURES ARE EXPECTED AGAIN...ESPECIALLY IN THE SOUTHEAST
PORTION.

SUNDAY/SUNDAY NIGHT...ABOVE MENTIONED JET MOVES ACROSS THE AREA
DURING THE DAY BUT MODELS DIFFER ON HOW FAST. MOST OF THEM HAVE THE
RIGHT REAR QUADRANT STILL AFFECT THE SOUTHERN PORTION OF THE AREA
AT 18Z WITH THE GFS FURTHER NORTH AND AFFECTING MOST OF THE AREA. BY
LATE IN THE AFTERNOON SOME KIND OF JET LIFT IS STILL AROUND OVER THE
SOUTHERN PORTION OF THE AREA. ALL THIS LOOKS TO MOVE SOUTH OF THE
AREA DURING THE EARLY EVENING. PER THE TRENDS AND REASONING MENTIONED
ABOVE...HELD ONTO HIGHER CHANCES PRECIPITATION CHANCES IN THE
MORNING WITH PRECIPITATION POSSIBLY LINGERING INTO THE EARLY
AFTERNOON IN THE FAR SOUTHERN PORTION.

HIGH TEMPERATURES WILL BE MUCH COOLER DUE TO LINGERING
PRECIPITATION/CLOUD COVER...AND UPSLOPE WINDS/COLD AIR ADVECTION.
BASED ON RECENT TRENDS/BEST PERFORMING GUIDANCE ALONG WITH THE
EXPECTED COOLING AT 850 MB...ADJUSTED THOSE TEMPERATURES A LITTLE...
ESPECIALLY COOLER WHERE CLOUDS HANG ON THE LONGEST. CLOUDS LOOK TO
CLEAR OUT OF MOST AREA EXCEPT POSSIBLY THE FAR SOUTHWEST. WINDS
BECOME LIGHT...ESPECIALLY IN THE EAST...SO LOWERED PREVIOUS MIN
FORECAST TO ACCOUNT FOR THIS.

MONDAY/MONDAY NIGHT...MID/UPPER LEVEL RIDGING AND DRIER AIR ALOFT
START BUILDING INTO THE AREA. ALSO PRESSURE GRADIENT INCREASES AS
SURFACE HIGH PULLS OFF TO THE EAST AND LEE TROUGH REDEVELOPS. SO
THIS AND PLENTY OF SUN SHOULD ALLOW TEMPERATURES TO RECOVER FROM
THE PREVIOUS DAY. A WEAK SHORTWAVE TROUGH AND INSTABILITY TRIES TO
SNEAK INTO THE FAR WESTERN PORTION OF THE AREA...ESPECIALLY DURING
THE NIGHT. DUE TO THE INCREASING HEIGHTS AND AIR MASS LOOKING TO BE
CAPPED THERE...KEPT IT DRY.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 211 AM MDT SAT AUG 31 2013

UPPER LEVEL BLOCKING PATTERN WILL CONTINUE OVER THE HIGH PLAINS FOR
THE EXTENDED FORECAST PERIOD...WHICH WILL KEEP WARM AND DRY
CONDITIONS OVER THE FORECAST AREA. THE 500 MB HIGH PRESSURE AREA
WILL BE CENTERED OVER COLORADO FOR TUESDAY AS RIDGE BECOMES MORE
AMPLIFIED INTO THE NORTHERN HIGH PLAINS. ZONAL FLOW WILL BEGIN TO
ENTER THE CENTRAL PLAINS FOR NEXT WEEKEND AS AN UPPER LEVEL LOW
MOVES OUT OF ALBERTA AND ACROSS THE NORTHERN PLAINS. SHORTWAVE
TROUGHS COULD DEVELOP AND MOVE THROUGH THE TRI STATE AREA SATURDAY
AND SUNDAY AS UPPER LEVEL HEIGHTS INCREASE AND RIDGE OF HIGH
PRESSURE BEGINS TO WEAKEN OVER THE SOUTHWEST REGION.

STRONG WARM AIR ADVECTION WILL CONTINUE AT THE SURFACE THROUGH THE
EXTENDED PERIOD...KEEPING SURFACE TEMPERATURES ABOVE AVERAGE IN THE
LOWER 90S. MODEL SOUNDINGS SHOW STABLE UPPER AIR PROFILE THROUGH THE
PERIOD...WITH A LACK OF INSTABILITY PARAMETERS AND AVAILABLE
MOISTURE.  SURFACE TEMPERATURES COULD POSSIBLY REACH THE CONVECTIVE
TEMPERATURES...WHICH ARE FORECASTED TO BE IN THE MID TO UPPER 90S.
STRONG CAP COULD BE BROKEN FOR ISOLATED LOCATIONS ALLOWING FOR SOME
SMALL AREAS OF STORM DEVELOPMENT.  CHANCES FOR PRECIPITATION ARE
VERY SLIM...WITH WARM AND DRY TREND CONTINUING INTO NEXT WEEKEND.
THE BEST CHANCE TO SEE PRECIPITATION ACROSS THE TRI STATE AREA WOULD
BE FOR NEXT WEEKEND AS UPPER LEVEL PATTERN BEGINS TO LOOK SUPPORTIVE
FOR STORM DEVELOPMENT...BUT MODEL RUNS STILL INDICATE DRY WEATHER AT
PRESENT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1130 AM MDT SAT AUG 31 2013

VFR CONDITIONS SHOULD PREVAIL THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK. PRIMARY AVIATION CONCERN IS POTENTIAL FOR
SHOWERS/THUNDERSTORMS AT BOTH TERMINALS THIS AFTERNOON/EVENING
WITH COLD FRONT PASSAGE. I LEFT VCTS GROUP IN PLACE AND ADJUSTED
TIMING TO ACCOUNT FOR ACTIVITY INCREASING IN COVERAGE AT KGLD
FIRST AND THEN TRENDING SOUTH DURING THE EVENING. WINDS WILL
GENERALLY BE LESS THAN 10KT AT BOTH TERMINALS WITH FRONT JUST
NORTHEAST...HOWEVER AS THE FRONT MOVES SOUTH TONIGHT WINDS WILL
INCREASE OUT OF THE NORTHEAST WITH GUSTS TO 20KT POSSIBLE THROUGH
SUN MORNING.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...DR
SHORT TERM...BULLER
LONG TERM...MK
AVIATION...DR







AREA FORECAST DISCUSSION

NWS WICHITA KS

 1142 AM CDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 1141 AM CDT SAT AUG 31 2013

OUTFLOW BOUNDARY FROM OVERNIGHT CONVECTION IN NEB PUSHED ACROSS MOST
OF THE FORECAST AREA THIS MORNING...CURRENTLY WASHING OUT ALONG
HIGHWAY 54. CLOUD DEBRIS AND SOME HIGHER SFC DEWPOINTS PUSHED ACROSS
NE SECTIONS OF THE FORECAST AREA EARLY TODAY....WHICH  HAD LED TO
SOME HIGHER SBCAPE VALUES ALONG OR JUST TO THE NORTH OF THIS REMNANT
BOUNDARY.  NOT ALOT OF CONVERGENCE NOTED ALONG THIS BOUNDARY...SO
THINK CHANCES OF AN ISOLATED STORM DEVELOPING IN THIS UNSTABLE AIR
ARE SLIM.  LATEST HIGH RES HRRR REFLECTIVITY MODEL SHOWS AN ISOLATED
STORM TRYING TO DEVELOP NEAR KEMP LATE THIS AFTERNOON. BUT THINK
THIS CHANCE IS TOO REMOTE FOR NOW TO MENTION IN THE GRIDS/ZONES.

THE MAIN CONCERN WILL BE THE HIGHER SFC DEWPOINTS STILL LOCATED
ACROSS CEN KS...ALONG I-70...WITH SOME CONCERN THAT THIS HIGHER
DEWPOINT AIR MAY REMAIN IN THE UPPER 60S THIS AFTERNOON.  WITH
CLOUDS CLEARING OUT...THINK THAT SFC TEMPS WILL WARM TO NEAR THE
CENTURY MARK THIS AFTERNOON IN THIS AREA. SO WITH UPPER 60S
DWPTS...THIS GIVES HEAT INDEX VALUES IN THE 104-108 RANGE.  SO THINK
THIS AREA MAY ALSO REACH DANGEROUS HEAT INDICE VALUE THAT WOULD
WARRANT AN EXPANSION OF THE HEAT ADVISORY ALONG I-70. ALSO THINK
THAT CURRENT HEAT ADVISORY OVER SE KS LOOKS FINE AS WELL...GIVEN SFC
DEWPOINTS WILL STAY HIGH IN THIS AREA AS WELL.

KETCHAM

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 300 AM CDT SAT AUG 31 2013

CONVECTION CONTINUES EARLY THIS MORNING FROM NORTHWEST KS TO SOUTH-
CENTRAL NEBRASKA ALONG AND BEHIND AN OUTFLOW BOUNDARY. WEAK
SOUTH-SOUTHWESTERLY WIND AT 850 MB OVERTOP OF THE OUTFLOW BOUNDARY
MAY SUSTAIN THIS ACTIVITY INTO EARLY THIS MORNING. THINK MOST OF IT
WILL STAY JUST NORTH/NORTHWEST OF OUR AREA...BUT WILL INCLUDE A
SLIGHT CHANCE POP BY RUSSELL/GREAT BEND/LINCOLN. CONVECTIVE DEBRIS
CLOUDINESS WILL LIKELY MOVE SOUTHEAST INTO CENTRAL KS THIS MORNING.
IF IT THINS OUT...THICKNESSES SUGGEST SIMILAR HIGHS TO YESTERDAY
AFTERNOON SO HAVE MAINTAINED FORECAST HIGHS OF 99-103. WITH VERY
LIGHT SOUTH WINDS...SOUTHEAST KS WILL PROBABLY BE ABLE TO MAINTAIN
DEWPOINTS AROUND 70 DEGREES INTO THIS AFTERNOON. THIS WILL PUT THEM
INTO HEAT ADVISORY CRITERIA WITH HEAT INDICES REACHING 104-107.
PLANNING A HEAT ADVISORY FROM 17Z-01Z THERE.

A SHORTWAVE TROUGH PRESENTLY OVER ALBERTA/SASKATCHEWAN WILL AMPLIFY
AS IT TRACKS EAST-SOUTHEASTWARD TO THE WESTERN GREAT LAKES BY SUNDAY
AFTERNOON. THE ASSOCIATED COLD FRONT IS STILL SLATED TO MOVE
SOUTHWARD THROUGH OUR AREA VERY LATE TONIGHT THROUGH SUNDAY.
LARGE-SCALE FORCING IS ON THE WEAK SIDE...ALTHOUGH A DECENT
PRECIPITABLE WATER AXIS (AROUND 1.5 INCHES) WILL ACCOMPANY THE
FRONTAL PASSAGE. WIDELY SEPARATED SHOWERS/STORMS WILL BE POSSIBLE
WITH THE FRONT MOVING THROUGH...ALTHOUGH NOT EXPECTING A
WIDESPREAD SOAKING RAIN EVENT. PLACES LUCKY ENOUGH TO RECEIVE RAIN
WILL PROBABLY GET 0.25 INCH OR LESS. COOLER AIR WILL SPREAD IN
BEHIND THE FRONT...FIRST FELT IN CENTRAL KS SUNDAY...AND AREA-WIDE
SUNDAY NIGHT INTO MONDAY.

JMC

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 300 AM CDT SAT AUG 31 2013

THE RESILIENT UPPER HIGH CENTER WILL RE-STRENGTHEN OVER THE
CENTRAL ROCKIES/HIGH PLAINS TOWARD MID-LATE WEEK WITH LEE TROUGH
DEVELOPMENT IN THE LOW-LEVELS. TEMPERATURES ARE EXPECTED TO WARM
TO ABOUT 5-9 DEGREES ABOVE NORMAL BY THE END OF THE WEEK. RECENT
RUNS OF THE ECMWF HAVE COME AROUND TOWARD THE GFS WITH THIS
SCENARIO...INCREASING FORECAST CONFIDENCE. UNFORTUNATELY...RAIN
CHANCES LOOK NIL.

JMC

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 633 AM CDT SAT AUG 31 2013

VFR CONDITIONS EXPECTED TO PREVAIL. AN OUTFLOW BOUNDARY/GRAVITY
WAVE IS PROPAGATING ACROSS SOUTH CENTRAL KANSAS THIS MORNING,
TURNING WINDS AROUND TO THE NORTH...BRIEFLY GUSTY BEFORE
WEAKENING. THE HRRR...WHILE THE TIMING IS OFF HAS THE BEST HANDLE
ON THIS AND TRENDED THE FORECAST WINDS BY USING IT AS A GUIDELINE
FOR EVOLUTION OF THE WIND FIELD TODAY. EXPECTING THE WAVE TO WASH
OUT AND THE WINDS TO BE COME EASTERLY...SOUTHEASTERLY AND
EVENTUALLY SOUTHERLY BY AFTERNOON. HOWEVER...NOT EXPECTING MUCH
CHANGE AFTER THIS POINT...LIGHT SOUTHERLY WINDS WITH SOME
SCATTERED TO BROKEN MID-HIGH CLOUDS.

BILLINGS


&&

.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT   102  73  93  66 /  10  20  20  10
HUTCHINSON     102  72  92  65 /  10  20  20  10
NEWTON         101  73  92  65 /  10  20  20  10
ELDORADO       101  74  93  66 /  10  20  20  10
WINFIELD-KWLD  101  73  96  68 /  10  10  20  10
RUSSELL        101  70  89  62 /  20  30  20  10
GREAT BEND     102  70  89  63 /  10  20  20  10
SALINA         101  72  90  63 /  10  30  20  10
MCPHERSON      101  72  91  64 /  10  20  20  10
COFFEYVILLE     99  73  96  68 /   0  10  20  10
CHANUTE         99  72  93  64 /  10  10  30  10
IOLA            99  74  93  64 /  10  20  30  10
PARSONS-KPPF    99  73  95  66 /   0  10  30  10

&&

.ICT WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ033-048-049-
051>053-069>072-094>096-098>100.

&&

$$








AREA FORECAST DISCUSSION

NWS GOODLAND KS

 852 AM MDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 852 AM MDT SAT AUG 31 2013

MAIN CHANGE WAS TO ADD MENTION OF THUNDERSTORMS TO FORECAST FOR
THE MORNING PERIOD. RADAR HAS BEEN SHOWING 20-35 DBZ RETURNS
ACROSS MUCH OF THE AREA THIS MORNING...HOWEVER THIS IS MAINLY
VIRGA. RECENT RETURNS HOWEVER HAVE SHOWN BRIEF/ISOLATED CORES OVER
40-45DBZ...WHICH WOULD PROBABLY BE ENOUGH FOR MEASURABLE PRECIP
IN THE CURRENT ENVIRONMENT. WITH SHORTWAVE STILL OVER CENTRAL
NEBRASKA (HIGHLIGHTED BY STRONG PV HEIGHT ANOMALY ON RAP ANALYSIS)
AND STALLED FRONT ALONG THE KS/NE BORDER WE COULD CONTINUE TO SEE
THIS ISOLATED ACTIVITY THROUGH MIDDAY. MODELS SHOW A GENERAL
CLEARING TREND THROUGH NOON BEFORE ACTIVITY BEGINS REDEVELOPING IN
THE WEST...SO I ONLY ADJUSTED TIMING OF CLOUD COVER AND MORNING
POPS. I WILL HAVE TO MONITOR WHAT IMPACT CLOUDS WILL HAVE ON
HIGHS TODAY IF THEY CONTINUE TO LINGER.

&&

.SHORT TERM...(TODAY THROUGH MONDAY NIGHT)
ISSUED AT 346 AM MDT SAT AUG 31 2013

MAIN FORECAST PROBLEM WILL BE PRECIPITATION THROUGH THE WEEKEND...
HOW HOT TO MAKE TODAY...AND HOW MUCH TO COOL DOWN TEMPERATURES
SUNDAY. SATELLITE SHOWING AN AMPLIFIED FLOW OVER THE EASTERN PACIFIC
WITH A FLATTER FLOW OVER THE COUNTRY. MID/UPPER LEVEL RIDGE THAT HAS
PERSISTED FOR A WHILE HAS BEEN FLATTENED AND PUSHED SOUTH BY
SHORTWAVES GOING ACROSS THE TOP OF IT. LOOKS LIKE WE HAVE A BETTER
SUBTROPICAL MOISTURE CONNECTION ACROSS THAN 24 HOURS AGO.

COMPLICATED SURFACE PATTERN WITH A FRONT THAT HAS SAGGED INTO THE
NORTHERN PORTION OF THE AREA. COMBINATION OF THIS BOUNDARY...WEAK
SHORTWAVE TROUGH...AND RIGHT REAR QUADRANT OF THE JET BROUGHT
THUNDERSTORMS TO THE NORTHERN HALF OF THE AREA WITH THE GREATEST
CONCENTRATION NEAR THE KANSAS AND NEBRASKA BORDER. THESE STORMS HAVE
THROWN OUT NUMEROUS OUTFLOW BOUNDARIES.

AT JET LEVEL...MODELS WERE HAVING A LITTLE TROUBLE WITH THE JET
SEGMENT JUST TO OUR NORTH. THEY DID NOT HAVE THE STRONGER WINDS FAR
ENOUGH SOUTH. HERE THE NAM WAS DOING A LITTLE BETTER THAN UKMET...
GFS..AND CANADIAN. AT MID LEVELS...THE CANADIAN AND UKMET WERE
DOING A LITTLE BETTER THAN THE GFS. OUTSIDE OF THE MESOSCALE
INFLUENCES THE CANADIAN WAS DOING THE BEST ON THE LOW LEVEL WIND
AND PRESSURE FIELD. THE GFS WAS DOING A LITTLE BETTER THAN THE
CANADIAN AND SREF ON THE LOW LEVEL THERMAL FIELD.

TODAY/TONIGHT...WEAK RIGHT REAR QUADRANT IS AFFECTING THE AREA NOW
AND IT MAY STILL BE NEAR OR OVER THE NORTHERN PORTION OF THE AREA AT
12Z. THIS WEAKENS OR PULLS AWAY FROM THE AREA AS STRONGER JET
DEVELOPS TO OUR NORTH WITH THE RIGHT FRONT QUADRANT AFFECTING THE
AREA IN THE AFTERNOON. INITIAL SHORTWAVE TROUGH ALSO LOOKS LIKE IT
MOVES EAST OF THE AREA THIS MORNING. BASED ON WHERE CURRENT
THUNDERSTORMS ARE OCCURRING BELIEVE THOSE STORMS SHOULD BE OUT OF
THE AREA BY 12Z. IT IS POSSIBLE THAT THERE MAY BE SOME
THUNDERSTORMS IN THE EAST EARLY. WILL MONITOR AS LONG AS POSSIBLE
BEFORE MAKING THE FINAL DECISION.

HOW MUCH DO CLOUDS HANG AROUND AND OVERNIGHT OUTFLOW BOUNDARIES WILL
AFFECT ALL PARAMETERS OF THE FORECAST. DAY SHIFT WILL HAVE TO PIN
WHERE OUTFLOW BOUNDARIES END UP AND MAY NEED TO ADJUST THE AREA OF
PRECIPITATION. TREND FOR THE INCOMING FRONT AND MID/UPPER LEVEL
SUPPORT HAS BEEN TO BE SLOWER. SO MADE ADJUSTMENTS TO THE
PRECIPITATION GRIDS TO REFLECT THIS. IF MESOSCALE DOES NOT CHANGE
THINGS...THEN EXPECT PRECIPITATION TO DEVELOP IN THE NORTHWEST HALF
IN THE AFTERNOON AND CONTINUE SOUTH AND EAST ACROSS THE AREA INTO
THE OVERNIGHT HOURS.

THIS INITIAL ROUND OF PRECIPITATION WILL BE TIED TO FRONT AND
SHORTWAVE TROUGH. THEN THE ABOVE MENTIONED JET LOOKS TO STAY NORTH OF
THE AREA THROUGH THE EVENING BEFORE COMING SOUTH AFTER 06Z. MOST OF
THE NORTHERN HALF LOOKS TO BE IN THE RIGHT REAR QUADRANT BY 12Z. THIS
IS FURTHER NORTH AT THIS TIME THAN WHAT THE MODELS WERE SHOWING
YESTERDAY. SO EXPECT SOME REDEVELOPMENT FURTHER NORTH BEHIND THE
FRONT.

IF CLOUDS HANG AROUND LONGER...WHICH RIGHT NOW THEY LOOK LIKE THEY
ARE THINNING...AND THE AIR MASS RECOVERS THE OVERNIGHT CONVECTION...
HOT TEMPERATURES ARE EXPECTED AGAIN...ESPECIALLY IN THE SOUTHEAST
PORTION.

SUNDAY/SUNDAY NIGHT...ABOVE MENTIONED JET MOVES ACROSS THE AREA
DURING THE DAY BUT MODELS DIFFER ON HOW FAST. MOST OF THEM HAVE THE
RIGHT REAR QUADRANT STILL AFFECT THE SOUTHERN PORTION OF THE AREA
AT 18Z WITH THE GFS FURTHER NORTH AND AFFECTING MOST OF THE AREA. BY
LATE IN THE AFTERNOON SOME KIND OF JET LIFT IS STILL AROUND OVER THE
SOUTHERN PORTION OF THE AREA. ALL THIS LOOKS TO MOVE SOUTH OF THE
AREA DURING THE EARLY EVENING. PER THE TRENDS AND REASONING MENTIONED
ABOVE...HELD ONTO HIGHER CHANCES PRECIPITATION CHANCES IN THE
MORNING WITH PRECIPITATION POSSIBLY LINGERING INTO THE EARLY
AFTERNOON IN THE FAR SOUTHERN PORTION.

HIGH TEMPERATURES WILL BE MUCH COOLER DUE TO LINGERING
PRECIPITATION/CLOUD COVER...AND UPSLOPE WINDS/COLD AIR ADVECTION.
BASED ON RECENT TRENDS/BEST PERFORMING GUIDANCE ALONG WITH THE
EXPECTED COOLING AT 850 MB...ADJUSTED THOSE TEMPERATURES A LITTLE...
ESPECIALLY COOLER WHERE CLOUDS HANG ON THE LONGEST. CLOUDS LOOK TO
CLEAR OUT OF MOST AREA EXCEPT POSSIBLY THE FAR SOUTHWEST. WINDS
BECOME LIGHT...ESPECIALLY IN THE EAST...SO LOWERED PREVIOUS MIN
FORECAST TO ACCOUNT FOR THIS.

MONDAY/MONDAY NIGHT...MID/UPPER LEVEL RIDGING AND DRIER AIR ALOFT
START BUILDING INTO THE AREA. ALSO PRESSURE GRADIENT INCREASES AS
SURFACE HIGH PULLS OFF TO THE EAST AND LEE TROUGH REDEVELOPS. SO
THIS AND PLENTY OF SUN SHOULD ALLOW TEMPERATURES TO RECOVER FROM
THE PREVIOUS DAY. A WEAK SHORTWAVE TROUGH AND INSTABILITY TRIES TO
SNEAK INTO THE FAR WESTERN PORTION OF THE AREA...ESPECIALLY DURING
THE NIGHT. DUE TO THE INCREASING HEIGHTS AND AIR MASS LOOKING TO BE
CAPPED THERE...KEPT IT DRY.

.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 211 AM MDT SAT AUG 31 2013

UPPER LEVEL BLOCKING PATTERN WILL CONTINUE OVER THE HIGH PLAINS FOR
THE EXTENDED FORECAST PERIOD...WHICH WILL KEEP WARM AND DRY
CONDITIONS OVER THE FORECAST AREA. THE 500 MB HIGH PRESSURE AREA
WILL BE CENTERED OVER COLORADO FOR TUESDAY AS RIDGE BECOMES MORE
AMPLIFIED INTO THE NORTHERN HIGH PLAINS. ZONAL FLOW WILL BEGIN TO
ENTER THE CENTRAL PLAINS FOR NEXT WEEKEND AS AN UPPER LEVEL LOW
MOVES OUT OF ALBERTA AND ACROSS THE NORTHERN PLAINS. SHORTWAVE
TROUGHS COULD DEVELOP AND MOVE THROUGH THE TRI STATE AREA SATURDAY
AND SUNDAY AS UPPER LEVEL HEIGHTS INCREASE AND RIDGE OF HIGH
PRESSURE BEGINS TO WEAKEN OVER THE SOUTHWEST REGION.

STRONG WARM AIR ADVECTION WILL CONTINUE AT THE SURFACE THROUGH THE
EXTENDED PERIOD...KEEPING SURFACE TEMPERATURES ABOVE AVERAGE IN THE
LOWER 90S. MODEL SOUNDINGS SHOW STABLE UPPER AIR PROFILE THROUGH THE
PERIOD...WITH A LACK OF INSTABILITY PARAMETERS AND AVAILABLE
MOISTURE.  SURFACE TEMPERATURES COULD POSSIBLY REACH THE CONVECTIVE
TEMPERATURES...WHICH ARE FORECASTED TO BE IN THE MID TO UPPER 90S.
STRONG CAP COULD BE BROKEN FOR ISOLATED LOCATIONS ALLOWING FOR SOME
SMALL AREAS OF STORM DEVELOPMENT.  CHANCES FOR PRECIPITATION ARE
VERY SLIM...WITH WARM AND DRY TREND CONTINUING INTO NEXT WEEKEND.
THE BEST CHANCE TO SEE PRECIPITATION ACROSS THE TRI STATE AREA WOULD
BE FOR NEXT WEEKEND AS UPPER LEVEL PATTERN BEGINS TO LOOK SUPPORTIVE
FOR STORM DEVELOPMENT...BUT MODEL RUNS STILL INDICATE DRY WEATHER AT
PRESENT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 536 AM MDT SAT AUG 31 2013

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. ISOLATED TO
SCATTERED THUNDERSTORMS SHOULD DEVELOP TO THE WEST OF BOTH TAF
SITES LATER THIS AFTERNOON. SOME MODEL DISAGREEMENT ON IF THIS
WILL BE THE CASE. HOWEVER...DUE TO OVERNIGHT CONVECTION
STABILIZING THE AIR MASS AND THE NEXT LIFT NOT EXPECTED TO ARRIVE
UNTIL MUCH LATER...DECIDED TO GO IN THIS DIRECTION. SINCE MAIN
TIME OF CONVECTION LOOKS TO BE UNTIL MUCH LATER THIS AFTERNOON AND
THIS EVENING...CHOSE TO HANDLE THUNDERSTORMS WITH A MENTION OF
VCTS. IF A STORM WOULD HAPPEN TO AFFECT ONE OF THE SITES...
CONDITIONS COULD BE BARELY WITHIN VFR OR BRIEFLY MOVE INTO THE
MVFR CATEGORY.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...DR
SHORT TERM...BULLER
LONG TERM...MK
AVIATION...BULLER








AREA FORECAST DISCUSSION

NWS PADUCAH KY

 857 PM CDT Sun Sep 1 2013

.UPDATE...
ISSUED AT 852 PM CDT SUN SEP 1 2013

The convection from earlier this afternoon/early evening has
dissipated. Some additional storms have fired near the lakes
region of western KY and this seems to be steming from some
convergence noted on the 00Z LAPS data. The storms seem to be
having a hard time staying together though.

Not seeing much hope for widespread convection ahead of the front
tonight. The HRRR is the only short term model that seems to have
a clue on what is currently going on with the cells in western KY,
and it suggests a mainly quiet night...with maybe some additional
development over parts of southern IL (up near I-64) and also in
parts of the Ozarks in SEMO. Will keep a generic 30-40 POP going
to cover these minor chances. SPC has removed the slight risk,
therefore, we are not expecting anything severe tonight if it does
materialize.

&&

.SHORT TERM...(This Evening through Tuesday Night)
ISSUED AT 246 PM CDT SUN SEP 1 2013

Outflow boundary will continue to slowly progress into southern
Illinois late this afternoon, with at least scattered
thunderstorms along it. Not sure how far south it will
develop/survive, but the boundary should be moving into a rather
juicy airmass, so would expect an uptick in coverage and intensity
at least over areas north of Highway 13. Wind fields are quite
weak, but instability and convergence on the boundary could
support a few strong to severe storms, albeit most likely short-
lived. Will keep pops in the chance category and gradually spread
them eastward toward the EVV Tri State through sunset.

The true cold front is well to the northwest across northern
Missouri and northwest Illinois. The consensus of 12Z models is
not as aggressive in pushing it through the entire area overnight.
The front should be near the Ohio/Wabash Rivers by 12Z Monday.

Not sure how much convection there will be this afternoon or what
kind of energy will be left for the front to work with tonight,
but will keep a zone of good chance pops along and just ahead of
it tonight. Cannot rule out a strong storm tonight, but given a much
less unstable airmass ahead of it than was the case last night,
would not expect severe weather. With the cold front being a bit
slower, also kept 20-30 pops through Monday morning over at least
the southeast half of the area. All precipitation should be
southeast of the area by 18Z Monday.

Kept temperatures at or just a bit above normal for highs on
Monday which is close to the consensus of guidance. This is a bit
of an increase due to the slower frontal passage. With a decent
surge of surface high pressure through the region Monday afternoon
and night, temperatures should be substantially lower on Tuesday.
The dry air really settles over the area on Tuesday, which with
good radiational cooling expected Tuesday night, could lead to some
chilly lows well into the 50s. Guidance may not be cool enough for
Tuesday night.

.LONG TERM...(Wednesday through Sunday)
ISSUED AT 246 PM CDT SUN SEP 1 2013

At this time the models are in good agreement for a dry extended
forecast. They do however indicate a dry frontal passage Thursday.
This is most apparent with another decrease in surface moisture more
than any other parameter...weak backdoor front. The init or allblend
came in a bit drier again today but leaned more heavily toward the
drier gfs especially the farther out time we go. This id mainly due
to a northeast to easterly flow over the region is not conducive to
good moisture flux over the area and believe the allblend is
contaminated with the ecmwf rather wet bias. At the surface we never
really get a southerly flow until the weekend. So held off on any
significant recovery of moisture until then. The models are hinting
at another front possibly precip about 10 days out.

As for temps slowly moderate back toward normal as we progress
through the week with a possible slow down in the warm up from
Thursdays backdoor front. Again with an easterly component to the
low level winds temperature recovery should be slow and gradual.

&&

.AVIATION...
ISSUED AT 658 PM CDT SUN SEP 1 2013

DIMINISHING CONVECTION IN WORKED OVER AIRMASS MAY STILL YIELD
BRIEF MENTION OF THUNDER/MVFR CONDITIONS FOR FIRST HOUR OR TWO OF
FORECAST...AFTER THAT IMPROVING CONDITIONS BUT PATCHY FOG MAY
OCCUR OVERNIGHT. FROPA LATE TONIGHT-EARLY AM MAY INCLUDE A SMALL
POP BUT WILL NOT INSERT IN TAF AT THIS WRITING. SHOULD SEE VFR
POST FRONTAL PASSAGE FOR MUCH OF DAY TMRW.


&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$

UPDATE...CW







AREA FORECAST DISCUSSION

NWS JACKSON KY

 540 PM EDT SAT AUG 31 2013

.MESOSCALE DISCUSSION...
ISSUED AT 540 PM EDT SAT AUG 31 2013

IN GENERAL...THE LINE ENTERING EASTERN KENTUCKY HAS BEEN WEAKENING.
JUST BEFORE THE LINE MOVED INTO THE AREA...AN OUTFLOW BOUNDARY MOVED
ACROSS THE AREA FROM NE TO SW AND AND HELPED TO DESTROY SOME OF THE
FAVORABLE STORM ENVIRONMENT. SOME TEMPERATURES STILL TO THE EAST OF
THE LINE ARE PRETTY WARM...SO DECIDED TO ISSUE A SPECIAL WEATHER
STATEMENT FOR THE LINE AS IT MAY STRENGTHEN AS THEY FIND MORE
FAVORABLE AIR. THE WARMER TEMPERATURES ARE GENERALLY WEST OF A LINE
FROM ROCKCASTLE TO BELL COUNTIES.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 420 PM EDT SAT AUG 31 2013

THE MAIN CLUSTER OF CONVECTION CONTINUES TO SLOWLY MOVE SOUTH ACROSS
PORTIONS OF EASTERN KENTUCKY. THIS CLUSTER WAS MORE ORGANIZED WHEN IT
WAS MOVING THROUGH THE I-64 CORRIDOR AND HAS SINCE BECOME MORE
CELLULAR. HEAVY RAINFALL IS THE MAIN CONCERN WITH THESE...HOWEVER
GIVEN THAT THE OUTFLOW HAS ALREADY SURGED SOUTH AWAY FROM THE
ACTIVITY...WOULD EXPECT THE STORMS TO CONTINUE TO GRADUALLY WEAKEN
WITH TIME.

ANOTHER MORE ORGANIZED AREA OF CONVECTION IS ALIGNED ACROSS NORTH
CENTRAL KENTUCKY ASSOCIATED MORE WITH A SUBTLE OUTFLOW BOUNDARY FROM
CONVECTION THAT HAD OCCURRED LAST NIGHT. THE LATEST HRRR HAS BEEN
KEEPING THIS CONVECTION MORE CONFINED TO SOUTHERN KENTUCKY WITH
TIME...ALTHOUGH IT IS NOT MAKING MUCH OF A TURN YET. CVG DOWN TO LEX
HAS RECOVERED WELL FROM EARLIER CLOUD COVER...HOWEVER THE AIR CLOSER
TOWARDS OUR BLUEGRASS COUNTIES IS NOT AS UNSTABLE. THE BEST
INSTABILITY REMAINS ACROSS OUR SOUTHWEST COUNTIES...WITH
TEMPERATURES IN THE UPPER 80S AND DEW POINTS IN THE UPPER 60S TO
LOWER 70S. THERE IS ALSO AN OUTFLOW BOUNDARY THAT APPEARS TO HAVE
STALLED FROM ALONG A MOUNT VERNON TO HARLAN LINE...WHICH MAY SERVE AS
A FOCUS FOR DEVELOPMENT THROUGH EARLY THIS EVENING. AS SUCH...WILL
HAVE SOME HIGHER POPS IN THE SOUTHWEST...WITH LOWER POPS IN THE
NORTHEAST WHERE CONVECTION HAS WORKED OVER THE AIR MASS.

WEAK SHORT WAVE TROUGHS WILL CONTINUE TO TRAVERSE THE OHIO VALLEY
THROUGH THE REST OF THE SHORT TERM...HOWEVER AS PREVIOUSLY STATED IN
EARLIER DISCUSSIONS...THE MESOSCALE WILL CONTINUE TO DRIVE THE
WEATHER. AS SUCH...HAVE STUCK WITH CONTINUITY...AND ALLOWED FOR A
GENERAL DIURNAL INCREASE IN CONVECTION THROUGH THE DAY ON SUNDAY...
HOWEVER COULD NOT DROP OFF THE POPS TOO MUCH AT NIGHT.

HEAVY RAINFALL WILL BE THE MAIN HAZARD THROUGH THE SHORT TERM...AND
WILL MENTION THE POTENTIAL FOR ISOLATED FLASH FLOODING NOW THAT SOME
LOCATIONS HAVE BEEN PRIMED. A FEW STRONGER STORMS COULD ALSO PRODUCE
SOME STRONG WIND GUSTS AND POSSIBLY SMALL HAIL AS WELL.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 437 PM EDT SAT AUG 31 2013

THE PREDOMINANT PATTERN DURING THE PERIOD WILL FEATURE A LARGE UPPER
LEVEL RIDGE CENTERED NEAR COLORADO...AND A BROAD TROUGH OVER THE
EASTERN CONUS WITH IMPULSES PASSING THROUGH IT. THIS RESULTS IN
GENERAL NW FLOW ALOFT FOR OUR AREA...WITH THE UPPER LEVEL IMPULSES
BRINGING SURFACE COLD FRONTS SOUTH AND SOUTHEAST. ONE OF THESE
IMPULSES AND FRONTS IS SLATED TO AFFECT US AT THE START OF THE
PERIOD...WITH FROPA ON MONDAY NIGHT. WITH GENERAL MODEL AGREEMENT ON
THIS...AND THE FRONT APPROACHING AT PEAK HEATING...HAVE USED LIKELY
POPS DURING THE DAY. WITH THE COLD FRONT EXPECTED TO PASS ON MONDAY
EVENING AND A LOSS OF HEATING...POPS DROP OFF FOR THE NIGHT. SURFACE
HIGH PRESSURE THEN BUILDS IN WITH A DRIER AIR MASS FOR TUESDAY.

ANOTHER COLD FRONT DROPS IN ON THURSDAY...BUT POOR MOISTURE RETURN
IS ANTICIPATED BEFORE FROPA...AND WILL GO WITH A DRY FORECAST.
ANOTHER COLD FRONT APPROACHES ON SATURDAY...BUT MODELS ARE NOT
CONSISTENT ON ITS STRENGTH OR TIMING. NONE OF THE MODELS SEEM TO
SHOW GOOD MOISTURE RETURN AT THIS POINT...AND HAVE LEFT THE FORECAST
DRY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 250 PM EDT SAT AUG 31 2013

ORGANIZED CONVECTION HAS STEERED CLEAR OF LOZ AND SME THUS FAR...SO
WILL CONTINUE TO MENTION A VCTS ONLY FOR THESE LOCATIONS. A CLUSTER
OF SHOWERS AND THUNDERSTORMS MAY SNEAK INTO JKL IN THE NEXT 30
MINUTES TO AN HOUR IF THEY CAN HOLD TOGETHER. OTHERWISE...EXPECT SOME
FOG TO FORM ONCE AGAIN TONIGHT...WITH A LINGERING THREAT OF AT LEAST
SCATTERED CONVECTION CARRYING THROUGH SUNDAY. SINCE JKL TOOK A DIRECT
HIT FROM EARLIER STORMS...HAVE GONE FOR IFR FOG CONDITIONS THERE. THE
FOG WILL MIX OUT BY AROUND 13Z.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

MESOSCALE...JJ
SHORT TERM...GEOGERIAN
LONG TERM...HAL
AVIATION...GEOGERIAN








AREA FORECAST DISCUSSION

NWS JACKSON KY

 437 PM EDT SAT AUG 31 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 420 PM EDT SAT AUG 31 2013

THE MAIN CLUSTER OF CONVECTION CONTINUES TO SLOWLY MOVE SOUTH ACROSS
PORTIONS OF EASTERN KENTUCKY. THIS CLUSTER WAS MORE ORGANIZED WHEN IT
WAS MOVING THROUGH THE I-64 CORRIDOR AND HAS SINCE BECOME MORE
CELLULAR. HEAVY RAINFALL IS THE MAIN CONCERN WITH THESE...HOWEVER
GIVEN THAT THE OUTFLOW HAS ALREADY SURGED SOUTH AWAY FROM THE
ACTIVITY...WOULD EXPECT THE STORMS TO CONTINUE TO GRADUALLY WEAKEN
WITH TIME.

ANOTHER MORE ORGANIZED AREA OF CONVECTION IS ALIGNED ACROSS NORTH
CENTRAL KENTUCKY ASSOCIATED MORE WITH A SUBTLE OUTFLOW BOUNDARY FROM
CONVECTION THAT HAD OCCURRED LAST NIGHT. THE LATEST HRRR HAS BEEN
KEEPING THIS CONVECTION MORE CONFINED TO SOUTHERN KENTUCKY WITH
TIME...ALTHOUGH IT IS NOT MAKING MUCH OF A TURN YET. CVG DOWN TO LEX
HAS RECOVERED WELL FROM EARLIER CLOUD COVER...HOWEVER THE AIR CLOSER
TOWARDS OUR BLUEGRASS COUNTIES IS NOT AS UNSTABLE. THE BEST
INSTABILITY REMAINS ACROSS OUR SOUTHWEST COUNTIES...WITH
TEMPERATURES IN THE UPPER 80S AND DEW POINTS IN THE UPPER 60S TO
LOWER 70S. THERE IS ALSO AN OUTFLOW BOUNDARY THAT APPEARS TO HAVE
STALLED FROM ALONG A MOUNT VERNON TO HARLAN LINE...WHICH MAY SERVE AS
A FOCUS FOR DEVELOPMENT THROUGH EARLY THIS EVENING. AS SUCH...WILL
HAVE SOME HIGHER POPS IN THE SOUTHWEST...WITH LOWER POPS IN THE
NORTHEAST WHERE CONVECTION HAS WORKED OVER THE AIR MASS.

WEAK SHORT WAVE TROUGHS WILL CONTINUE TO TRAVERSE THE OHIO VALLEY
THROUGH THE REST OF THE SHORT TERM...HOWEVER AS PREVIOUSLY STATED IN
EARLIER DISCUSSIONS...THE MESOSCALE WILL CONTINUE TO DRIVE THE
WEATHER. AS SUCH...HAVE STUCK WITH CONTINUITY...AND ALLOWED FOR A
GENERAL DIURNAL INCREASE IN CONVECTION THROUGH THE DAY ON SUNDAY...
HOWEVER COULD NOT DROP OFF THE POPS TOO MUCH AT NIGHT.

HEAVY RAINFALL WILL BE THE MAIN HAZARD THROUGH THE SHORT TERM...AND
WILL MENTION THE POTENTIAL FOR ISOLATED FLASH FLOODING NOW THAT SOME
LOCATIONS HAVE BEEN PRIMED. A FEW STRONGER STORMS COULD ALSO PRODUCE
SOME STRONG WIND GUSTS AND POSSIBLY SMALL HAIL AS WELL.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 437 PM EDT SAT AUG 31 2013

THE PREDOMINANT PATTERN DURING THE PERIOD WILL FEATURE A LARGE UPPER
LEVEL RIDGE CENTERED NEAR COLORADO...AND A BROAD TROUGH OVER THE
EASTERN CONUS WITH IMPULSES PASSING THROUGH IT. THIS RESULTS IN
GENERAL NW FLOW ALOFT FOR OUR AREA...WITH THE UPPER LEVEL IMPULSES
BRINGING SURFACE COLD FRONTS SOUTH AND SOUTHEAST. ONE OF THESE
IMPULSES AND FRONTS IS SLATED TO AFFECT US AT THE START OF THE
PERIOD...WITH FROPA ON MONDAY NIGHT. WITH GENERAL MODEL AGREEMENT ON
THIS...AND THE FRONT APPROACHING AT PEAK HEATING...HAVE USED LIKELY
POPS DURING THE DAY. WITH THE COLD FRONT EXPECTED TO PASS ON MONDAY
EVENING AND A LOSS OF HEATING...POPS DROP OFF FOR THE NIGHT. SURFACE
HIGH PRESSURE THEN BUILDS IN WITH A DRIER AIR MASS FOR TUESDAY.

ANOTHER COLD FRONT DROPS IN ON THURSDAY...BUT POOR MOISTURE RETURN
IS ANTICIPATED BEFORE FROPA...AND WILL GO WITH A DRY FORECAST.
ANOTHER COLD FRONT APPROACHES ON SATURDAY...BUT MODELS ARE NOT
CONSISTENT ON ITS STRENGTH OR TIMING. NONE OF THE MODELS SEEM TO
SHOW GOOD MOISTURE RETURN AT THIS POINT...AND HAVE LEFT THE FORECAST
DRY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 250 PM EDT SAT AUG 31 2013

ORGANIZED CONVECTION HAS STEERED CLEAR OF LOZ AND SME THUS FAR...SO
WILL CONTINUE TO MENTION A VCTS ONLY FOR THESE LOCATIONS. A CLUSTER
OF SHOWERS AND THUNDERSTORMS MAY SNEAK INTO JKL IN THE NEXT 30
MINUTES TO AN HOUR IF THEY CAN HOLD TOGETHER. OTHERWISE...EXPECT SOME
FOG TO FORM ONCE AGAIN TONIGHT...WITH A LINGERING THREAT OF AT LEAST
SCATTERED CONVECTION CARRYING THROUGH SUNDAY. SINCE JKL TOOK A DIRECT
HIT FROM EARLIER STORMS...HAVE GONE FOR IFR FOG CONDITIONS THERE. THE
FOG WILL MIX OUT BY AROUND 13Z.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GEOGERIAN
LONG TERM...HAL
AVIATION...GEOGERIAN









AREA FORECAST DISCUSSION

NWS JACKSON KY

 420 PM EDT SAT AUG 31 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 420 PM EDT SAT AUG 31 2013

THE MAIN CLUSTER OF CONVECTION CONTINUES TO SLOWLY MOVE SOUTH ACROSS
PORTIONS OF EASTERN KENTUCKY. THIS CLUSTER WAS MORE ORGANIZED WHEN IT
WAS MOVING THROUGH THE I-64 CORRIDOR AND HAS SINCE BECOME MORE
CELLULAR. HEAVY RAINFALL IS THE MAIN CONCERN WITH THESE...HOWEVER
GIVEN THAT THE OUTFLOW HAS ALREADY SURGED SOUTH AWAY FROM THE
ACTIVITY...WOULD EXPECT THE STORMS TO CONTINUE TO GRADUALLY WEAKEN
WITH TIME.

ANOTHER MORE ORGANIZED AREA OF CONVECTION IS ALIGNED ACROSS NORTH
CENTRAL KENTUCKY ASSOCIATED MORE WITH A SUBTLE OUTFLOW BOUNDARY FROM
CONVECTION THAT HAD OCCURRED LAST NIGHT. THE LATEST HRRR HAS BEEN
KEEPING THIS CONVECTION MORE CONFINED TO SOUTHERN KENTUCKY WITH
TIME...ALTHOUGH IT IS NOT MAKING MUCH OF A TURN YET. CVG DOWN TO LEX
HAS RECOVERED WELL FROM EARLIER CLOUD COVER...HOWEVER THE AIR CLOSER
TOWARDS OUR BLUEGRASS COUNTIES IS NOT AS UNSTABLE. THE BEST
INSTABILITY REMAINS ACROSS OUR SOUTHWEST COUNTIES...WITH
TEMPERATURES IN THE UPPER 80S AND DEW POINTS IN THE UPPER 60S TO
LOWER 70S. THERE IS ALSO AN OUTFLOW BOUNDARY THAT APPEARS TO HAVE
STALLED FROM ALONG A MOUNT VERNON TO HARLAN LINE...WHICH MAY SERVE AS
A FOCUS FOR DEVELOPMENT THROUGH EARLY THIS EVENING. AS SUCH...WILL
HAVE SOME HIGHER POPS IN THE SOUTHWEST...WITH LOWER POPS IN THE
NORTHEAST WHERE CONVECTION HAS WORKED OVER THE AIR MASS.

WEAK SHORT WAVE TROUGHS WILL CONTINUE TO TRAVERSE THE OHIO VALLEY
THROUGH THE REST OF THE SHORT TERM...HOWEVER AS PREVIOUSLY STATED IN
EARLIER DISCUSSIONS...THE MESOSCALE WILL CONTINUE TO DRIVE THE
WEATHER. AS SUCH...HAVE STUCK WITH CONTINUITY...AND ALLOWED FOR A
GENERAL DIURNAL INCREASE IN CONVECTION THROUGH THE DAY ON SUNDAY...
HOWEVER COULD NOT DROP OFF THE POPS TOO MUCH AT NIGHT.

HEAVY RAINFALL WILL BE THE MAIN HAZARD THROUGH THE SHORT TERM...AND
WILL MENTION THE POTENTIAL FOR ISOLATED FLASH FLOODING NOW THAT SOME
LOCATIONS HAVE BEEN PRIMED. A FEW STRONGER STORMS COULD ALSO PRODUCE
SOME STRONG WIND GUSTS AND POSSIBLY SMALL HAIL AS WELL.

.LONG TERM...(MONDAY THROUGH FRIDAY) ISSUED AT 300 AM EDT SAT AUG 31 2013

A STRENGTHENING UPPER LEVEL SHORTWAVE OVER THE UPPER GREAT LAKES
WILL BE THE MAIN CONCERN TO START OUT THE FORECAST PERIOD. WHILE
HIGH PRESSURE CONTINUES TO LIE OVER THE SE...THIS SHORTWAVE OVER THE
GREAT LAKES WILL INTENSIFY AND MOVE EASTWARD SUNDAY NIGHT AND
THROUGH THE DAY MONDAY. THIS WILL PLACE UPPER LEVEL TROUGHING AND AN
ASSOCIATED SURFACE FRONTAL BOUNDARY ACROSS THE OHIO VALLEY. AHEAD OF
THIS COLD FRONTAL PASSAGE...ALREADY MOIST AIR WILL BE IN PLACE. SO
WITH CONTINUED HOT AND HUMID AIR FLOWING FROM THE SOUTH...EXPECT THE
CHANCES OF SHOWERS AND THUNDERSTORMS TO CONTINUE THROUGH SUNDAY
NIGHT. THE ACTUAL COLD FRONT IS PROGGED TO TRAVERSE EASTERN KY
MONDAY AFTERNOON. THIS COUPLED WITH DIURNAL HEATING WILL MAKE FOR
THE BEST CHANCES OF CONVECTIVE ACTIVITY. THE FACT PW VALUES ARE
STILL FORECASTED TO BE ABOVE NORMAL...AND STORM MOTION SLOW...SOME
HEAVY DOWNPOURS WILL NOT BE OUT OF THE QUESTION MONDAY AFTERNOON.

ONCE THE COLD FRONT PASSES THROUGH EASTERN KY...DRY AIR WILL BEGIN
WORKING IN ALOFT AND EVENTUALLY MAKE ITS WAY DOWN TO THE
SURFACE...CUTTING OFF ALL PRECIP CHANCES ACROSS EASTERN KY BY
TUESDAY MORNING. THIS DRY AIR WILL BE ASSOCIATED WITH A HIGH
PRESSURE CENTERED OVER THE UPPER MISSISSIPPI VALLEY TUESDAY. IN
TERMS OF WEATHER IMPACTS...THIS WILL PROVIDE A MUCH NEEDED BREAK
FROM NOT ONLY THE PRECIPITATION CHANCES...BUT THE HOT AND HUMID
WEATHER THAT WE HAVE BEEN EXPERIENCING. COLDER AND DRIER CONTINENTAL
AIR WILL REST OVER THE OHIO RIVER VALLEY...WITH HIGH TEMPS ONLY
EXPECTED AROUND 80 DEGREES FOR TUESDAY THROUGH THURSDAY. WITH LOW
DEW POINTS IN PLACE...AND MOSTLY CLEAR SKIES...THE DIURNAL SHIFT
WILL BE QUITE LARGE...WITH OVERNIGHT LOWS DIPPING DOWN INTO THE
UPPER 50S ACROSS PORTIONS OF THE REGION.

FOR THE REMAINDER OF THE FORECAST PERIOD...A FEW SUBTLE SHORTWAVES
WILL TRY TO MAKE THEIR WAY TOWARDS THE OHIO RIVER VALLEY...NAMELY
FRIDAY INTO SATURDAY. HOWEVER WITH SUCH STRONG SUBSIDENCE IN
PLACE...LATEST MODEL RUNS ARE SHOWING ANY PRECIP CHANCES DYING OFF
BEFORE THEY REACH EASTERN KY. OVERALL IT LOOKS TO BE A GREAT SECOND
HALF OF THE WORKWEEK AND START TO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 250 PM EDT SAT AUG 31 2013

ORGANIZED CONVECTION HAS STEERED CLEAR OF LOZ AND SME THUS FAR...SO
WILL CONTINUE TO MENTION A VCTS ONLY FOR THESE LOCATIONS. A CLUSTER
OF SHOWERS AND THUNDERSTORMS MAY SNEAK INTO JKL IN THE NEXT 30
MINUTES TO AN HOUR IF THEY CAN HOLD TOGETHER. OTHERWISE...EXPECT SOME
FOG TO FORM ONCE AGAIN TONIGHT...WITH A LINGERING THREAT OF AT LEAST
SCATTERED CONVECTION CARRYING THROUGH SUNDAY. SINCE JKL TOOK A DIRECT
HIT FROM EARLIER STORMS...HAVE GONE FOR IFR FOG CONDITIONS THERE. THE
FOG WILL MIX OUT BY AROUND 13Z.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GEOGERIAN
LONG TERM...JMW
AVIATION...GEOGERIAN








AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON KY

 240 AM EDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 225 AM EDT SAT AUG 31 2013

DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE LATEST RADAR TRENDS
AND POPS FROM THE HIGH RESOLUTION HRRR MODEL. THIS ENTAILED A RAMP
UP TO THE POPS A BIT EARLIER IN THE CUMBERLAND VALLEY ALONG WITH A
MORE IN THE WAY OF SKY COVER. ALSO ADJUSTED THE HOURLY T/TD GRIDS
BASED ON VARIANCES WITH THE LATEST OBS AND EXTENDED THEM FORWARD IN A
DAMPENING MANNER FOR THE NEXT SEVERAL HOURS. DID ALSO FINE TUNE THE
FOG IN THE WX GRIDS...INCLUDING SOME DENSE PATCHES IN THE DEEPER
VALLEYS OF THE EAST. UPDATES HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS WHILE THE CURRENT ZONES STILL COVER THE OVERNIGHT PORTION OF
THE FORECAST.

UPDATE ISSUED AT 1026 PM EDT FRI AUG 30 2013

THE FORECAST CONTINUES TO BE ON TRACK SO FAR THIS EVENING IN ALL
REGARDS. TEMPERATURES...SKY COVER...AND WINDS WERE VERY CLOSE TO
ACTUAL OBSERVED CONDITIONS ACROSS THE ENTIRE FORECAST. THEREFORE...NO
UPDATED TO THE FORECAST IS PLANNED AT THIS TIME.

UPDATE ISSUED AT 725 PM EDT FRI AUG 30 2013

THE FORECAST IS RIGHT ON TRACK...SO NO UPDATE IS PLANNED AT THIS TIME.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 335 PM EDT FRI AUG 30 2013

A LARGE UPPER LEVEL RIDGE OF HIGH PRESSURE CENTERED ACROSS THE DESERT
SOUTHWEST HAS BEEN MAINTAINING DRY WEATHER ACROSS EASTERN KENTUCKY
FOR THE PAST FEW DAYS. SOME CONVECTION HAS MANAGED TO POP UP DOWN
ALONG THE TERRAIN IN TENNESSEE THIS AFTERNOON...HOWEVER THE CAP SEEMS
TO BE HOLDING ACROSS OUR SOUTHEAST COUNTIES THUS FAR. STILL...CAN NOT
COMPLETELY RULE OUT A FEW BUILD UPS THROUGH DUSK.

THE MODELS ARE IN GOOD AGREEMENT WITH THE LONG WAVE PATTERN THROUGH
THE SHORT TERM...WITH THE DESERT SOUTHWEST RIDGE GRADUALLY WEAKENING
AS SHORT WAVE ENERGY MOVES IN FROM CANADA AND TRAVERSES THE GREAT
LAKES AND OHIO VALLEY. THERE ARE MODEL DIFFERENCES CONCERNING THE
TIMING ON THE INTERMITTENT SHORT WAVE ENERGY...SO WILL CONTINUE TO
RELY ON THE CONTINUITY OF THE PREVIOUS FORECAST...BRINGING THE THREAT
OF SOME ISOLATED CONVECTION IN TOWARDS DAWN TONIGHT AS THE FIRST WEAK
WAVE APPROACHES. ONCE HEATING TAKES PLACE ON SATURDAY...EXPECT SCATTERED
CONVECTION TO FIRE UP. HIGHS WILL BE SIMILAR TO TODAY...WITH MID TO
UPPER 80S...ALTHOUGH THERE WILL LIKELY BE MORE CLOUD COVER IN THE
AFTERNOON...SO SOME LOCATIONS MAY NOT GET QUITE AS WARM.

ON SATURDAY NIGHT...THERE IS A LITTLE MORE TROUGHINESS THAT TAKES
SHAPE ACROSS THE OHIO VALLEY...SO STILL LIKE THE IDEA OF A LESS STEEP
DIURNAL DROP OFF IN THE POPS...AS THERE MAY BE SOME SCATTERED
CONVECTION FROM TIME TO TIME THROUGH THE NIGHT.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 335 PM EDT FRI AUG 30 2013

THE PERIOD WILL BEGIN WITH AN UPPER LEVEL RIDGE OF HIGH PRESSURE
OVER THE SOUTHERN ROCKIES/FOUR CORNERS REGION WITH TROUGHING FROM
THE HUDSON/JAMES BAY REGION SOUTH INTO THE GULF OF MEXICO REGION.
THIS TROUGH WAS BETWEEN THE TROUGH OVER THE ROCKIES AND ANOTHER
RIDGE CENTERED EAST OF THE BAHAMAS. A FEW SHORTWAVES ARE PROGGED TO
BE WORKING THROUGH THE OH VALLEY AT THAT TIME...ONE WORKING THROUGH
THE OH VALLEY LATE IN THE SHORT TERM PERIOD...POSSIBLY EXITING TO
THE EAST OF THE JKL CWA EARLY ON SUNDAY AND ANOTHER WORKING INTO THE
OH VALLEY ON SUNDAY. BEHIND THIS SECOND ONE...A SHORTWAVE ASSOCIATED
WITH AN UPPER LEVEL LOW WORKING ACROSS ONTARIO AND INTO QUEBEC AND
SHOULD HELP TO AMPLIFY THE EASTERN CONUS EARLY IN THE NEW WEEK AS IT
WORKS THROUGH THE GREAT LAKES AND OH VALLEY REGION INTO THE
NORTHEAST AND MID ATLANTIC THROUGH TUE AND WED. A SFC COLD FRONT
SHOULD PRECEDE THIS FINAL SHORTWAVE MENTIONED ABOVE AND MOVE SOUTH OF
THE OH RIVER MON EVENING/MONDAY NIGHT BEFORE EXITING THE CWA ON
TUESDAY.

BY MIDWEEK...THE CONSENSUS IS FOR UPPER LEVEL RIDGING TO BE CENTERED
OVER COLORADO WITH AN UPPER LEVEL LOW OFF THE PACIFIC NORTHWEST COAST
AND THE EASTERN TROUGH GRADUALLY LIFTING OUT TO THE NORTHEAST.
ANOTHER CLOSED LOW PASSING ACROSS THE HUDSON/JAMES BAY REGION INTO
THE CANADIAN MARITIMES FROM MID TO LATE WEEK SHOULD SEND ANOTHER
COLD FRONT THAT WILL BE BECOMING INCREASINGLY SHEARED AS IT REACHES
THE JKL CWA DURING THE SECOND HALF OF THE WEEK. MOISTURE SHOULD BE
LIMITED WITH THE SECOND BOUNDARY WITH LITTLE TIME FOR RETURN FLOW.

OVERALL...THE START OF THE WEEK SHOULD BE MOST ACTIVE AND UNSETTLED
WITH ROUNDS OF SCATTERED SHOWERS OR THUNDERSTORMS POSSIBLE AT TIMES
WITH EACH PASSING SHORTWAVE UNTIL THE COLD FRONT MOVES ACROSS
EASTERN AND SOUTH CENTRAL KY. COVERAGE SHOULD BE GREATEST DIURNALLY
ON AVERAGE...FOR SUNDAY AND MONDAY. A FEW HEAVY DOWNPOURS CANNOT BE
RULED OUT WITH THESE...ON SUN INTO SUN EVENING AS SHEAR AND WIND
FIELDS WILL BE WEAKEST SO STORM MOTIONS SHOULD BE LEAST WHILE PW WILL
BE A BIT ABOVE AVERAGE. PW IS FORECAST TO BE HIGHER ON MONDAY...BUT
AHEAD OF THE FRONT AND APPROACHING TROUGH STORM MOTIONS SHOULD BE
HIGHER.

AFTER SLIGHT CHANCE TO LIKELY POPS FOR THE SUN THROUGH TUESDAY
PERIOD...WE CONTINUED WITH A DRY FORECAST FOR THE REMAINDER OF THE
WEEK. WITH THE SECOND FRONT DURING THE SECOND HALF OF THE WEEK A
SHOWER OR THUNDERSTORM CANNOT BE RULED OUT FROM THU AFTERNOON
THROUGH FRIDAY...BUT THE BEST FORCING SHOULD REMAIN TO OUR NORTH AND
EAST.

INCREASING MOISTURE AND ASSOCIATED CLOUD COVER AND PRECIP IN THE
AREA SHOULD HOLD TEMPS WELL BELOW THE WARM MAV NUMBERS AND PROBABLY
BELOW THE MET NUMBERS AS WELL. THE HIGHS ON SUN AND MON WERE TRENDED
TOWARD THE COLDER CONSALL AND ECMWF MOS GUIDANCE. AFTER MONDAY...
HIGH TEMPERATURES SHOULD AVERAGE AS MUCH AS 5 DEGREES BELOW NORMAL
WITH MIN TEMPS ANTICIPATED TO BE A COUPLE OF DEGREES BELOW NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 240 AM EDT SAT AUG 31 2013

ASIDE FROM SOME MVFR FOG AT LOZ...CONDITIONS WERE VFR AT THE TAF
SITES AND MOST OTHER PLACES. EXPECT SOME PATCHY FOG TO AFFECT JKL AND
LOZ THROUGH DAWN...BUT SME WILL PROBABLY BE SPARED SIMILAR TO LAST
NIGHT. THERE IS A POTENTIAL FOR A FEW SHOWERS TO POP UP IN THE
VICINITY OF THE TAF SITES TOWARDS DAWN. A THREAT OF THUNDERSTORMS
WILL EXIST FROM THEN ON INTO THE DAY AND NIGHT SATURDAY AS A LOW
PRESSURE AREA APPROACHES AND ACTIVATES OUR CURRENT WARM AND MOIST
AIR MASS. HAVE GONE WITH PREVAILING SHOWERS AND VCTS AT THE SITES BY
EARLY AFTERNOON. HAVE BACKED THESE OFF TO JUST A MENTION OF VCTS
AFTER 00Z AS COVERAGE SHOULD BECOME MORE SCATTERED. LATE NIGHT VISBY
RESTRICTIONS WILL BE POSSIBLE AT LOCATIONS THAT SEE RAIN...BUT HAVE
LEFT THAT OUT OF THE TAFS FOR NOW. WINDS THROUGH THE PERIOD...OUTSIDE
OF ANY STORM...WILL BE LIGHT AND VARIABLE.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...JP
AVIATION...GREIF







AREA FORECAST DISCUSSION...UPDATED

NWS GRAY ME

 657 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A COLD FRONT OVER EASTERN CANADA WILL DROP SOUTHWARD TOWARDS THE
INTERNATIONAL BORDER TODAY. LOW PRESSURE IS FORECAST TO TRACK
EASTWARD ALONG THIS FRONTAL BOUNDARY TONIGHT. THE BOUNDARY WILL
REMAIN STALLED THROUGH SUNDAY. A WARM FRONT LIFTS THROUGH THE
REGION ON MONDAY WITH A COLD FRONT MOVING EAST TUESDAY NIGHT INTO
WEDNESDAY MORNING. A SECONDARY COLD FRONT SWEEPS THROUGH ON
THURSDAY. HIGH PRESSURE BUILDS IN FRIDAY AND SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...HAVE GONE AHEAD AND TRIMMED BACK POP IN THE N BASED ON
CURRENT TRENDS THIS MORNING. STRONG PUSH OF DRY AIR ALOFT...PER
WATER VAPOR IMAGERY...HAS WORKED INTO NRN ZONES. INDICATIVE OF AT
LEAST SOME SUBSIDENCE ALOFT...THIS SHOULD LIMIT SHRA ACTIVITY AT
LEAST THRU THE FIRST PART OF THE DAY. THIS IS SUPPORTED WELL BY
08Z HRRR RUN...WHICH FAVORS CONVECTION RE-FIRING ALONG SAGGING
FRONTAL BOUNDARY DRAPED ACROSS THE SRN CWFA THIS AFTERNOON. HAVE
OPTED TO KEEP LIKELY POP GOING FOR THOSE AREAS OF SRN NH AND
ADJACENT SWRN ME AFTER 15Z OR SO.

PREVIOUS DISCUSSION...COMPLEX FORECAST IN STORE FOR TODAY...AS
WEAK FNT DROPS INTO THE REGION AND STALLS. ONE MCS HAS MOVED THRU
THE NORTH COUNTRY OF NH...AND REACHED PENOBSCOT BAY OVER THE
COURSE OF THE LAST SEVERAL HOURS. ANOTHER AREAS OF SHRA AND
EMBEDDED TSTMS FARTHER SW WILL MOVED EWD INTO THE CWFA OVER THE
NEXT COUPLE OF HOURS. THESE COMPLEXES WILL LEAVE BEHIND OUTFLOW
BOUNDARIES THAT WILL HELP ACT TO REINFORCE THE DIFFERENCE BETWEEN
THE WARM SECTOR AND THE RELATIVELY COOLER AIR TO THE N.

HAVE FAVORED A BLEND WITH THE GFS POP...AS IT SEEMS TO HAVE THE
RIGHT IDEA THAT COLD FNT WILL HANG UP ACROSS THE SRN ZONES TODAY.
EXPECT THAT WITH DIURNAL HEATING THIS FEATURE WILL BECOME THE
FOCUS FOR SHRA/TSTMS AND POSSIBLY MORE LOOSELY ORGANIZED MCS/S
LIKE TONIGHT. CANNOT RULE OUT AN ISOLD STRONGER STORM...AS DEEP
UNIDIRECTIONAL FLOW AND PCPN LOADING COULD PRODUCE SOME GUSTY
WINDS. PWAT VALUES APPROACHING 2 SD ABOVE NORMAL WILL MEAN HEAVY
RNFL IS POSSIBLE WITH ANY STRONGER CONVECTION AS WELL.

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
FRONTAL BOUNDARY WILL LIKELY WAFFLE BACK AND FORTH AS CONVECTION
MOVES ALONG IT TODAY AND TONIGHT. EXPECT THAT IT WILL REMAIN
NEARER THE COAST AND SRN NH VS THE MTNS. SAME IS TRUE FOR DURING
THE DAY SUN...WHERE EVENTUALLY S/WV APPROACHING FROM THE NW HELPS
LIFT BOUNDARY BACK N AS A WARM FNT.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
A FRONTAL BOUNDARY WILL REMAIN RELATIVELY STATIONARY OVER THE
FORECAST AREA SUNDAY NIGHT AS LOW PRESSURE DEVELOPS WEST OF OUR
REGION. THIS WILL ALLOW SCATTERED SHOWERS AND THUNDERSTORMS TO
CONTINUE ACROSS THE REGION.

BY MONDAY...A COLD FRONT WILL BEGIN TO APPROACH THE
REGION...ALLOW A MOIST...SOUTHERLY FLOW TO PICK UP OFF THE GULF OF
MAINE. SHOWERS AND PATCHY DRIZZLE WILL BECOME MORE NUMEROUS
DURING THE DAY. THERE MAY BE SUFFICIENT INSTABILITY OVER IN NEW
HAMPSHIRE TO ALLOW FOR GUSTY SHOWERS AND THUNDERSTORMS TO DEVELOP.
POPS WILL BE ON THE INCREASE MONDAY INTO INTO TUESDAY MORNING AS A
COLD FRONT SWEEPS ACROSS NEW HAMPSHIRE AND THEN MAINE. THIS TIMING
OF THIS FRONT WILL BE CRITICAL AS A SLOWER PROGRESSION OF THE
FRONT...SIMILAR TO THE GGEM MODEL...MAY ALLOW FOR SOME AFTERNOON
HEATING AND GUSTY STORM OVER SOUTHERN AREAS ONCE AGAIN.

HYDRO...WITH A WARM...HUMID AIRMASS IN PLACE...AND PRECIPITABLE WATER
VALUES NEAR TWO INCHES...ANY STORMS MAY PRODUCE LOCALLY HEAVY
RAINFALL. THIS WILL NEED TO BE MONITORED OVER THE WEEKEND.

A WEAK RIDGE OF HIGH PRESSURE WILL BUILD OVER NEW ENGLAND ON
WEDNESDAY. THEREAFTER...ANOTHER COLD FRONT WILL APPROACH FROM THE
SAINT LAWRENCE RIVER VALLEY AS A VERY CHILLY...CANADIAN HIGH
PRESSURE SYSTEM BUILDS QUICKLY SOUTH FOR LATE IN THE WEEK.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...FNT STALLING OVER THE AREA TODAY WILL LEAD TO ROUNDS
OF SHRA AND TSTMS. SCT MVFR OR LOWER CONDS WILL BE PSBL IN ANY
STORMS RIGHT THRU SUN.

LONG TERM...PERIODS OF MVFR/IFR ARE EXPECTED SUNDAY NIGHT THROUGH
TUESDAY IN THUNDERSTORMS...SHOWERS...AND FOG. TIMING OF INDIVIDUAL
DROPS IN CEILING/VISIBILITY WILL BE HARD TO PIN DOWN BUT WITH
AMPLE MOISTURE...LATE EVENING INTO THE EARLY MORNING HOURS EACH
DAY WILL SEE RESTRICTIONS.

&&

.MARINE...
SHORT TERM...WINDS AND SEAS WILL APPROACH SCA THRESHOLDS AT TIMES
TODAY...WITH SUSTAINED ONSHORE FLOW BUILDING SEAS TO NEAR 5 FT BY
SUN.

LONG TERM...SEAS WILL BE AROUND 3-5 FT SUNDAY NIGHT INTO MONDAY
MORNING OVER THE OUTER WATERS...DO TO A STALLED BOUNDARY JUST
NORTH OF THE WATERS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$

LEGRO/JC







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 321 PM EDT SAT AUG 31 2013

.SYNOPSIS...
WARM AND HUMID CONDITIONS WITH PERIODIC SHOWERS AND THUNDERSTORMS
WILL PREVAIL THROUGH THE LABOR DAY WEEKEND.

&&

.NEAR TERM /THROUGH SUNDAY/...
AS OF MID-AFTERNOON...CONVECTION HAS GENERALLY BEEN A BUST SO
FAR. EXCEPT FOR A FEW ISOLATED SHOWERS ALONG THE INTERSTATE 80
CORRIDOR...ALL LOCATIONS HAVE REMAINED DRY SINCE MID-MORNING.
CONSIDERING THE MAIN UPPER LEVEL SHORTWAVE HAS ALREADY PUSHED EAST
OF THE REGION...DO NOT REALLY SEE ANYTHING THAT WILL PROVIDE MUCH
OF A FORCING MECHANISM UNTIL THE NEXT SHORTWAVE AFFECTING THE AREA
LATE TONIGHT INTO SUNDAY. AS A RESULT...HAVE CUT WAY BACK ON POPS
EARLY...RAMPING THEM UP AGAIN BY LATE TONIGHT. HOWEVER...CANNOT
COMPLETELY DISCOUNT THE POSSIBILITY OF A LINE OF SHOWERS/STORMS
DEVELOPING FROM NORTHEAST TO SOUTHWEST ACROSS THE REGION WHICH
SEVERAL RUNS OF THE HRRR HAS BEEN INSISTENT WILL DEVELOP JUST
BEFORE SUNSET. ANOTHER STICKY NIGHT CAN BE EXPECTED WITH LOWS ONLY
DROPPING TO AROUND 70.

A BIT OF DISAGREEMENT BETWEEN MODELS FOR TOMORROWS FORECAST. ALL OF
THE SYNOPTIC MODELS BRING A DECENT SHORTWAVE FROM EASTERN OHIO IN
THE MORNING TO CENTRAL PENNSYLVANIA BY THE AFTERNOON...TRIGGERING
WIDESPREAD PRECIPITATION. ON THE OTHER HAND...ALL OF THE HIGH
RESOLUTION MODELS SHOW MUCH LESS COVERAGE WITH PRECIP. SEEING AS THE
SHORTWAVE IN QUESTION IS CURRENTLY OVER CHICAGO PRODUCING SHOWERS
AND THUNDERSTORMS...WILL STICK WITH THE SYNOPTIC MODEL SOLUTIONS. A
SCENARIO SIMILAR TO TODAY COULD OCCUR...WITH THE HIGHEST POPS
POTENTIALLY ARRIVING IN THE MORNING ACROSS WESTERN PORTIONS OF THE
AREA ALONG WITH THE SHORTWAVE AND REMNANT THUNDERSTORMS.
HOWEVER...WILL PUT IN LIKELY POPS ALONG THE RIDGES DURING THE EARLY
AFTERNOON WHILE THE SHORTWAVE IS PASSING THROUGH.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
THERE SHOULD BE A BRIEF LULL IN PRECIPITATION SUNDAY EVENING WITH
THE UPPER LEVEL SHORTWAVE TO THE EAST AND THE NEXT COLD FRONT OUT
TO THE WEST. RAIN SHOULD BEGIN TO OVERTAKE THE EASTERN COUNTIES
VERY EARLY MONDAY...AND THE FRONT WILL BE HUGGING THE RIDGES BY
MONDAY EVENING. INSTABILITY AND WIND SHEAR SHOULD BE HIGH ENOUGH
THAT A FEW STRONGER THUNDERSTORMS ARE POSSIBLE...BUT OVERALL
SEVERE THREAT APPEARS TO BE LOW.TEMPERATURES SUNDAY NIGHT AND
MONDAY SHOULD BE SIMILAR TO THOSE THROUGH THE EARLIER PORTIONS OF
THE WEEKEND.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE CDFNT IS FORECAST TO EXIT THE RGN MON NGT AND END THE SHWR
CHCS. BLDG HIGH PRES SHOULD THEN MAINTAIN DRY WEATHER UNTIL
PASSAGE OF ANOTHER WEAK CDFNT ON THU. LTD MSTR IS PROGGED WITH
THAT FNT...SO ONLY SLGT CHC POPS WERE INCLUDED ATTM. UNDR ERN
CONUS TROFG ALOFT...SUB AVG TEMPS ARE EXPD INTO SATURDAY.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
GENERAL VFR EXPECTED IS FORECAST TODAY ALTHOUGH SOME SHWRS AND
TSTMS MAY MAR UPR OH VALLEY WEA LTR THIS AFTN AND THIS EVE. THE
BTR CHC OF THIS OCCURRENCE LKS TO BE OVR AREAS E OF PIT AS PER
POSITIONING OF A SLOW-MOVG MID LVL TROF. TAFS HAVE THUS BEEN
AMENDED TO INCLUDED TSTM MENTION AT ONLY AT MGW FOR NOW.

OTHERWISE...A MORE SIGNIFICANT SHRTWV IS MDL-INDICATED FOR A
SUNDAY PASSAGE. GIVEN MSTR SUPPLY AND INCRSG ASCENT...HAVE
FORECAST DEGRADED CIGS/MVFR CONDITIONS FOR THE PREDAWN WITH IFR
AT FKL AND DUJ. MORE WIDESPREAD SHWRS AND CONTD RESTRICTIONS ARE
ANTICIPATED FOR SUNDAY.

.OUTLOOK.../SUNDAY THROUGH THURSDAY/...
A DECISIVE CDFNT PASSAGE IS STILL SLATED FOR MONDAY. RESTRICTIONS
MAY THUS BE EXPECTED UNTIL HIGH PRES BUILDS FOR TUESDAY THROUGH
THURSDAY.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 143 PM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO DRIFT FARTHER OFFSHORE TODAY AS A
WEAK TROUGH DEVELOPS OVER THE PIEDMONT OF VIRGINIA. A COLD FRONT
WILL APPROACH THE REGION FROM THE WEST ON MONDAY...AND WILL PUSH
ACROSS THE AREA TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD
INTO THE MID ATLANTIC STATES ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE LATEST WX ANALYSIS SHOWS ~1016 MB SFC HIGH PRESSURE SITUATED
WELL OFF THE MID ATLC/SE COAST...WITH PRESSURE FALLS INDICATING A
DEVELOPING LEE TROUGH ALONG/WEST OF THE I-95 CORRIDOR. CURRENT
WV SATELLITE AND REGIONAL RADAR REVEALS A RATHER SMALL BUT SHARP
SHORTWAVE DIVING SE THROUGH OHIO WITH AN ASSOCIATED MCS SPREADING
THROUGH SE OHIO/ERN KY. MODELS TO A VARYING DEGREE BEGIN TO SPREAD
INCREASING MOISTURE INTO WRN PORTIONS OF THE CWA AFTER 18Z THIS
AFTN. WILL CONTINUE TO WATCH THE CURRENT ACTIVITY CLOSELY TO SEE
IF IT HOLDS TOGETHER UPON REACHING THE APPALACHIANS...CURRENT
THINKING IS THAT IT PROBABLY WILL NOT ALTHOUGH THE HRRR ACTUALLY
SPREADS SOME SCATTERED SHOWERS INTO WRN PORTIONS OF THE CWA BY 18Z
(BUT IT DEVELOPS THIS FROM AN AREA OF PRECIP OVER SOUTH CENTRAL VA
AND NCENTRAL NC WHICH THUS FAR HAS NOT OCCURRED).

OVERALL...FORECAST HAS BEEN CHANGED VERY LITTLE FOR THE AFTN...FAVORING
AREAS WEST OF I-95 FOR LOW CHC POPS BY LATE AFTN/EARLY EVENING WITH
20% OR LOWER POPS FARTHER EAST WHERE INSTABILITY PARAMETERS ARE LOWER
(ML CAPES 1000 J/KG OR LESS). GFS/NAM DO SHOW SOME DECENT MID
LEVEL LAPSE RATES > 6.5 C/KM THIS AFTN/EVENING BUT DEEP LAYER
BULK SHEAR WILL AVG 20-25 KT NORTH TO < 20 KT SOUTH SO ORGANIZED
STRONG STORMS ARE UNLIKELY ESPECIALLY OVER SOUTHERN 1/2 OF THE CWA.
PRECIPITABLE WATER VALUES RISE TO 1.50 TO 1.80" BY AFTN SO MAIN
ISSUE WOULD BE LOCALLY HEAVY RAIN. FOR TEMPS, EXPECT HIGHS TODAY
GENERALLY IN THE UPPER 80S TO AROUND 90...LOCALLY MID 80S ON THE
IMMEDIATE COAST.

CONSIDERING RATHER ANEMIC DYNAMICS/FORCING, RAIN CHCS END QUICKLY
TONIGHT. EXPECT A PARTLY CLOUDY AND DRY NIGHT ACROSS THE LOCAL
AREA WITH EARLY MORNING LOWS IN THE UPR 60S TO LOW 70S.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
RAIN CHCS INCREMENTALLY RAMP UPWARDS FOR THE LATTER HALF OF THE
HOLIDAY WEEKEND AS LONGWAVE TROUGH CONTINUES TO AMPLIFY/DEEPEN
OVER THE MID-ATLANTIC REGION. MOISTURE WL GRADUALLY INCREASE
THROUGH THIS PERIOD GIVEN SW FLOW AHEAD OF THE SLOW MOVING COLD
FRONT THAT IS PROGGED TO MOVE ACROSS THE LOCAL AREA BY TUESDAY.
HIGH END CHC (40%) POPS FOR SHRAS/TSTMS MOST AREAS BOTH DAYS
(LOWER FAR SE) AS SEVERAL ADDITIONAL SPOKES OF SHORTWAVE ENERGY
EMBEDDED WITHIN THE LARGER TROUGH ROTATE THROUGH. THREAT FOR SVR
WX APPEARS LOW ATTM GIVEN LACK OF SHEAR, THOUGH WITH PW ~2",
LOCALLY HVY RAINFALL IS ONCE AGAIN A CONCERN (OVER INLAND AREAS
SUNDAY, CLOSER TO THE COAST ON MONDAY). HIGHS SUN/MON UPR 80S TO
LOW 90S. LOWS SUN NIGHT IN THE UPR 60S TO LOW 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LARGE SCALE PATTERN DURING THE MEDIUM RANGE PERIOD CHARACTERIZED BY
LARGE MID LVL RIDGE IN THE SW U.S. AND A MID LEVEL TROUGH OVER THE
EASTERN CONUS. LATEST 12Z GFS/ECMWF NOW INTO BETTER AGREEMENT THAN
THEIR 00Z RUNS HAD BEEN WITH THE LATER PART OF NEXT WEEK. BOTH
MODELS NOW SHOW THE UPPER RIDGE EXPANDING NORTH INTO THE NORTHERN
ROCKIES BY MIDWEEK...EFFECTIVELY SENDING A REINFORCING SHOT OF COOL
AIR AND UPPER TROUGHING SE INTO THE GREAT LAKES AND NE CONUS BY
THU/FRI. FOR THE LOCAL AREA...THIS PATTERN WILL PUSH THE ACTUAL
FRONT THROUGH DURING THE DAY TUE...WITH MOISTURE AND INSTABILITY
PROFILES FAVORING HIGHEST POPS TUE AFTN OVER FAR SOUTHERN/SE VA AND
NC (30-50%) WITH SOMEWHAT DRIER AIR AND LESS COVERAGE OF STORMS
FARTHER N/W. HIGHS TUE GENLY HELD IN THE 80S DUE TO MORE CLOUD
COVER. HIGH PRESSURE BUILDS IN FROM THE WNW TUE NIGHT-WED...AND
PERSISTS OVER THE REGION INTO THU AS THE DEEP UPPER TROUGH BECOMES
ANCHORED OVER EASTERN CANADA. EXPECT COOLER AND DRIER/MORE
COMFORTABLE CONDITIONS WITH HIGHS MAINLY 80-85 AND LOWS IN THE UPPER
50S NW TO MID 60S FAR SE ON WED. FLOW BRIEFLY TURNS BACK TO THE SW
ON THU ALLOWING FOR SOMEWHAT WARMER TEMPS INTO THE MID OR POSSIBLY
UPPER 80S AHEAD OF THE NEXT FRONT. THIS FRONT LOOKS TO COME THROUGH
THU NIGHT/EARLY FRI WITH MINIMAL DYNAMICS SO WILL KEEP FORECAST DRY
WITH JUST SOME INCREASE IN CLOUDS. PARTLY TO MOSTLY SUNNY FRI W/
HIGHS IN THE UPPER 70S TO LOWER 80S.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 17Z...SCT CU COVERED THE TAF SITES EARLY SATURDAY AFTN. A
SHORT WAVE MOVING THROUGH WEST VIRGINIA AND A LEESIDE TROUGH MAY
RESULT IN SOME CONVECTION OVER WESTERN VA LATER THIS AFTN. ANY TSTMS
THAT DO FORM HAVE A RATHER A LOW PROBABILITY OF AFFECTING THE TAF
SITES AND KEPT MENTION OF PCPN OUT OF TAFS FOR NOW. CLOUD COVER AND
A STEADY S/SW WIND SHOULD INHIBIT FOG FORMATION SUNDAY MORNING.

OUTLOOK...SHOWERS AND THUNDERSTORMS HAVE A BETTER CHANCE OF
AFFECTING THE AREA SUNDAY AFTN AND NIGHT AND AGAIN ON MONDAY. DRIER
WEATHER RETURNS TOWARD MIDWEEK. NO WIDESPREAD IFR IS INDICATED AT
THIS TIME.

&&

.MARINE...
THE WATERS BECOME POSITIONED BTWN HIGH PRESSURE OFF THE MID
ATLANTIC COAST AND A LOW PRESSURE SYSTEM MOVING ACROSS THE ERN
GREAT LAKES TODAY..RESULTING IN A TIGHTENING PRESSURE GRADIENT.
SOUTH WINDS ON CHES BAY AND COASTAL WATERS NORTH OF THE VA/NC
BORDER WILL AVERAGE 10-15 KT THIS MORNING THROUGH EARLY AFTERNOON
AND THEN INCREASE TO 15-20 KT BY LATE AFTERNOON ON CHES BAY (A
SOLID 20 KT FOR COASTAL WATERS)...PERSISTING THROUGH THE OVERNIGHT
HOURS INTO SUNDAY MORNING. CURRITUCK SOUND MAY EXPERIENCE GUSTS
AROUND 20 KT LATE THIS AFTERNOON INTO EARLY EVENING...HOWEVER THE
DURATION OF THE WIND GUSTS SHOULD BE SHORT-LIVED. CONFIDENCE IS
NOT HIGH ENOUGH TO ISSUE SCA FLAGS FOR THE SOUND AND ANY GUSTY
WINDS DURING THIS TIME FRAME TODAY MAY BE COVERED WITH MARINE
WEATHER STATEMENTS INSTEAD. WILL NEED TO MONITOR. A SECONDARY SLY
SURGE IS EXPECT TO BEGIN AROUND MIDNIGHT...PUSHING GUSTS ON CHES
BAY UP TWD 25 KT. WAVES ON CHES BAY WILL AVERAGE 2-3 FT AND SEAS
WILL AVERAGE 3-4 FT. SCA FLAGS FOR CHES BAY HAVE BEEN ISSUED
BEGINNING LATE THIS AFTERNOON THROUGH 10 AM EDT SUNDAY MORNING.
MEANWHILE...A MID LEVEL TROUGH CROSSING THE REGION AND INTERACTING
WITH A LEE TROUGH WILL TRIGGER SHOWERS AND THUNDERSTORMS DURING
THIS AFTERNOON AND EVENING. A FEW STORMS MAY MOVE OVER THE BAY
NORTH OF NEW POINT COMFORT WHILE THE REST OF THE WATERS REMAIN
RAIN-FREE.

A COLD FRONT WILL APPROACH THE REGION FROM THE WEST ON SUNDAY INTO
MONDAY. THE FRONT IS EXPECTED TO MOVE INTO THE MID ATLANTIC REGION
MONDAY NIGHT AND THEN STALL ALONG THE COAST ON TUESDAY. WINDS ARE
EXPECTED TO BECOME MORE SWLY MONDAY INTO TUESDAY AND REMAIN AOB
15 KT. A COOL NW-N SURGE EITHER TUESDAY NIGHT OR EARLY WEDNESDAY MAY
RESULT IN A PERIOD OF SCA HEADLINES...ALTHOUGH TIMING ON THIS
CONTINUES TO BE UNCERTAIN.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EDT
     SUNDAY FOR ANZ630>632-634.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB/MAM
SHORT TERM...JDM/MAM
LONG TERM...LKB
AVIATION...LSA
MARINE...BMD








AREA FORECAST DISCUSSION

NWS WAKEFIELD VA

 1058 AM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO DRIFT FARTHER OFFSHORE TODAY AS A
WEAK TROUGH DEVELOPS OVER THE PIEDMONT OF VIRGINIA. A COLD FRONT
WILL APPROACH THE REGION FROM THE WEST ON MONDAY...AND WILL PUSH
ACROSS THE AREA TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD
INTO THE MID ATLANTIC STATES ON WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
THE LATEST WX ANALYSIS SHOWS ~1016 MB SFC HIGH PRESSURE SITUATED
WELL OFF THE MID ATLC/SE COAST...WITH PRESSURE FALLS INDICATING A
DEVELOPING LEE TROUGH ALONG/WEST OF THE I-95 CORRIDOR. CURRENT
WV SATELLITE AND REGIONAL RADAR REVEALS A RATHER SMALL BUT SHARP
SHORTWAVE DIVING SE THROUGH OHIO WITH AN ASSOCIATED MCS SPREADING
THROUGH SE OHIO/ERN KY. MODELS TO A VARYING DEGREE BEGIN TO SPREAD
INCREASING MOISTURE INTO WRN PORTIONS OF THE CWA AFTER 18Z THIS
AFTN. WILL CONTINUE TO WATCH THE CURRENT ACTIVITY CLOSELY TO SEE
IF IT HOLDS TOGETHER UPON REACHING THE APPALACHIANS...CURRENT
THINKING IS THAT IT PROBABLY WILL NOT ALTHOUGH THE HRRR ACTUALLY
SPREADS SOME SCATTERED SHOWERS INTO WRN PORTIONS OF THE CWA BY 18Z
(BUT IT DEVELOPS THIS FROM AN AREA OF PRECIP OVER SOUTH CENTRAL VA
AND NCENTRAL NC WHICH THUS FAR HAS NOT OCCURRED).

OVERALL...FORECAST HAS BEEN CHANGED VERY LITTLE FOR THE AFTN...FAVORING
AREAS WEST OF I-95 FOR LOW CHC POPS BY LATE AFTN/EARLY EVENING WITH
20% OR LOWER POPS FARTHER EAST WHERE INSTABILITY PARAMETERS ARE LOWER
(ML CAPES 1000 J/KG OR LESS). GFS/NAM DO SHOW SOME DECENT MID
LEVEL LAPSE RATES > 6.5 C/KM THIS AFTN/EVENING BUT DEEP LAYER
BULK SHEAR WILL AVG 20-25 KT NORTH TO < 20 KT SOUTH SO ORGANIZED
STRONG STORMS ARE UNLIKELY ESPECIALLY OVER SOUTHERN 1/2 OF THE CWA.
PRECIPITABLE WATER VALUES RISE TO 1.50 TO 1.80" BY AFTN SO MAIN
ISSUE WOULD BE LOCALLY HEAVY RAIN. FOR TEMPS, EXPECT HIGHS TODAY
GENERALLY IN THE UPPER 80S TO AROUND 90...LOCALLY MID 80S ON THE
IMMEDIATE COAST.

CONSIDERING RATHER ANEMIC DYNAMICS/FORCING, RAIN CHCS END QUICKLY
TONIGHT. EXPECT A PARTLY CLOUDY AND DRY NIGHT ACROSS THE LOCAL
AREA WITH EARLY MORNING LOWS IN THE UPR 60S TO LOW 70S.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
RAIN CHCS INCREMENTALLY RAMP UPWARDS FOR THE LATTER HALF OF THE
HOLIDAY WEEKEND AS LONGWAVE TROUGH CONTINUES TO AMPLIFY/DEEPEN
OVER THE MID-ATLANTIC REGION. MOISTURE WL GRADUALLY INCREASE
THROUGH THIS PERIOD GIVEN SW FLOW AHEAD OF THE SLOW MOVING COLD
FRONT THAT IS PROGGED TO MOVE ACROSS THE LOCAL AREA BY TUESDAY.
HIGH END CHC (40%) POPS FOR SHRAS/TSTMS MOST AREAS BOTH DAYS
(LOWER FAR SE) AS SEVERAL ADDITIONAL SPOKES OF SHORTWAVE ENERGY
EMBEDDED WITHIN THE LARGER TROUGH ROTATE THROUGH. THREAT FOR SVR
WX APPEARS LOW ATTM GIVEN LACK OF SHEAR, THOUGH WITH PW ~2",
LOCALLY HVY RAINFALL IS ONCE AGAIN A CONCERN (OVER INLAND AREAS
SUNDAY, CLOSER TO THE COAST ON MONDAY). HIGHS SUN/MON UPR 80S TO
LOW 90S. LOWS SUN NIGHT IN THE UPR 60S TO LOW 70S.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
LARGE SCALE PATTERN DURING THE MEDIUM RANGE PERIOD CHARACTERIZED BY
LARGE MID LVL RIDGE IN THE SW U.S. AND A MID LEVEL TROUGH OVER THE
EASTERN CONUS. LATEST 12Z GFS/ECMWF NOW INTO BETTER AGREEMENT THAN
THEIR 00Z RUNS HAD BEEN WITH THE LATER PART OF NEXT WEEK. BOTH
MODELS NOW SHOW THE UPPER RIDGE EXPANDING NORTH INTO THE NORTHERN
ROCKIES BY MIDWEEK...EFFECTIVELY SENDING A REINFORCING SHOT OF COOL
AIR AND UPPER TROUGHING SE INTO THE GREAT LAKES AND NE CONUS BY
THU/FRI. FOR THE LOCAL AREA...THIS PATTERN WILL PUSH THE ACTUAL
FRONT THROUGH DURING THE DAY TUE...WITH MOISTURE AND INSTABILITY
PROFILES FAVORING HIGHEST POPS TUE AFTN OVER FAR SOUTHERN/SE VA AND
NC (30-50%) WITH SOMEWHAT DRIER AIR AND LESS COVERAGE OF STORMS
FARTHER N/W. HIGHS TUE GENLY HELD IN THE 80S DUE TO MORE CLOUD
COVER. HIGH PRESSURE BUILDS IN FROM THE WNW TUE NIGHT-WED...AND
PERSISTS OVER THE REGION INTO THU AS THE DEEP UPPER TROUGH BECOMES
ANCHORED OVER EASTERN CANADA. EXPECT COOLER AND DRIER/MORE
COMFORTABLE CONDITIONS WITH HIGHS MAINLY 80-85 AND LOWS IN THE UPPER
50S NW TO MID 60S FAR SE ON WED. FLOW BRIEFLY TURNS BACK TO THE SW
ON THU ALLOWING FOR SOMEWHAT WARMER TEMPS INTO THE MID OR POSSIBLY
UPPER 80S AHEAD OF THE NEXT FRONT. THIS FRONT LOOKS TO COME THROUGH
THU NIGHT/EARLY FRI WITH MINIMAL DYNAMICS SO WILL KEEP FORECAST DRY
WITH JUST SOME INCREASE IN CLOUDS. PARTLY TO MOSTLY SUNNY FRI W/
HIGHS IN THE UPPER 70S TO LOWER 80S.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AREAS OF FOG HAVE DEVELOPED ACROSS NE NC AND EXTREME SE VA THIS
MORNING. LIMITED CEILINGS ARE AVERAGING 200-400 FT AGL AND
VISIBILITIES HAVE BEEN REDUCED TO THREE QUARTERS OF A MILE OR LESS
IN THESE AREAS. CONDITIONS SHOULD BEGIN TO LIFT/DISSIPATE AROUND
31/1300Z.

BY MID TO LATE MORNING...SURFACE HIGH PRESSURE CONTINUES TO MOVE
EAST OF THE MID ATLANTIC COAST AND A SURFACE LOW CROSSES THE EASTERN
GREAT LAKES. THE PRESSURE GRADIENT BTWN THESE FEATURES WILL BEGIN TO
TIGHTEN AND A LEE TROUGH IS EXPECTED TO DEVELOP. AS THIS
OCCURS...SOUTH WINDS WILL QUICKLY BECOME BREEZY WITH GUSTS TO AROUND
20 KT BY EARLY AFTERNOON. MEANWHILE...ENERGY AND MOISTURE ASSOCIATED
WITH THE MID LEVEL OHIO VALLEY TROUGH WILL INTERACT WITH THE LEE
TROUGH AND CAUSE SHOWERS/THUNDERSTORMS TO DEVELOP THIS
AFTERNOON/EVENING. PRECIPITATION CHANCES HAVE BEEN LIMITED TO AREAS
NW OF A LINE FROM KSBY-KRIC-KAVC...HOWEVER ISOLATED STORMS MAY BE
POSSIBLE CLOSER TO THE COAST. WILL NEED TO MONITOR.

A MORE SUBSTANTIAL SURFACE COLD FRONT APPROACHES FROM THE WEST ON
SUNDAY AND PUSHES A MORE BROAD-SCALE MID LEVEL TROUGH OVER THE MID
ATLANTIC REGION. THIS WILL RESULT IN INCREASED SHOWER/THUNDERSTORM
CHANCES AND COVERAGE ON SUNDAY...WHICH WILL BE EVEN HIGHER ON MONDAY
DURING THE FRONTAL PASSAGE. THE FRONT APPEARS TO STALL ALONG THE
COAST TUESDAY AND SHOWER/STORMS WILL ONCE AGAIN BE POSSIBLE. BREEZY
S-SW WINDS SHOULD BE ANTICIPATED EACH AFTERNOON FROM SATURDAY
THROUGH TUESDAY. WINDS THEN VEER TO THE W-NW BEHIND THE FRONT.

&&

.MARINE...
THE WATERS BECOME POSITIONED BTWN HIGH PRESSURE OFF THE MID
ATLANTIC COAST AND A LOW PRESSURE SYSTEM MOVING ACROSS THE ERN
GREAT LAKES TODAY..RESULTING IN A TIGHTENING PRESSURE GRADIENT.
SOUTH WINDS ON CHES BAY AND COASTAL WATERS NORTH OF THE VA/NC
BORDER WILL AVERAGE 10-15 KT THIS MORNING THROUGH EARLY AFTERNOON
AND THEN INCREASE TO 15-20 KT BY LATE AFTERNOON ON CHES BAY (A
SOLID 20 KT FOR COASTAL WATERS)...PERSISTING THROUGH THE OVERNIGHT
HOURS INTO SUNDAY MORNING. CURRITUCK SOUND MAY EXPERIENCE GUSTS
AROUND 20 KT LATE THIS AFTERNOON INTO EARLY EVENING...HOWEVER THE
DURATION OF THE WIND GUSTS SHOULD BE SHORT-LIVED. CONFIDENCE IS
NOT HIGH ENOUGH TO ISSUE SCA FLAGS FOR THE SOUND AND ANY GUSTY
WINDS DURING THIS TIME FRAME TODAY MAY BE COVERED WITH MARINE
WEATHER STATEMENTS INSTEAD. WILL NEED TO MONITOR. A SECONDARY SLY
SURGE IS EXPECT TO BEGIN AROUND MIDNIGHT...PUSHING GUSTS ON CHES
BAY UP TWD 25 KT. WAVES ON CHES BAY WILL AVERAGE 2-3 FT AND SEAS
WILL AVERAGE 3-4 FT. SCA FLAGS FOR CHES BAY HAVE BEEN ISSUED
BEGINNING LATE THIS AFTERNOON THROUGH 10 AM EDT SUNDAY MORNING.
MEANWHILE...A MID LEVEL TROUGH CROSSING THE REGION AND INTERACTING
WITH A LEE TROUGH WILL TRIGGER SHOWERS AND THUNDERSTORMS DURING
THIS AFTERNOON AND EVENING. A FEW STORMS MAY MOVE OVER THE BAY
NORTH OF NEW POINT COMFORT WHILE THE REST OF THE WATERS REMAIN
RAIN-FREE.

A COLD FRONT WILL APPROACH THE REGION FROM THE WEST ON SUNDAY INTO
MONDAY. THE FRONT IS EXPECTED TO MOVE INTO THE MID ATLANTIC REGION
MONDAY NIGHT AND THEN STALL ALONG THE COAST ON TUESDAY. WINDS ARE
EXPECTED TO BECOME MORE SWLY MONDAY INTO TUESDAY AND REMAIN AOB
15 KT. A COOL NW-N SURGE EITHER TUESDAY NIGHT OR EARLY WEDNESDAY MAY
RESULT IN A PERIOD OF SCA HEADLINES...ALTHOUGH TIMING ON THIS
CONTINUES TO BE UNCERTAIN.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 10 AM EDT
     SUNDAY FOR ANZ630>632-634.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB/MAM
SHORT TERM...JDM/MAM
LONG TERM...LKB
AVIATION...BMD
MARINE...BMD







AREA FORECAST DISCUSSION...UPDATED

NWS BALTIMORE MD/WASHINGTON DC

 1011 AM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFFSHORE THIS WEEKEND WHILE A SERIES OF
UPPER DISTURBANCES MOVE THROUGH THE AREA. A COLD FRONT WILL MOVE
THROUGH THE REGION MONDAY NIGHT. HIGH PRESSURE RETURNS MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
MONITORING THE INCOMING SHORTWAVE OVER THE ERN OHIO RVR VLY. THE
SRN - OR WRN - FLANK OF THE WAVE HAS BEEN AND CONTINUES TO DEVELOP
POCKETS OF STRONG CONVECTION ALONG IT BUT THE NRN END HAS LARGELY
STRATIFORMED OUT AND HAS BECOME MORE STABLE ARRIVING AT THE
APLCNS. NOW THAT WE`RE W/IN THE TIME RANGES OF LOCAL 1-HR
GUIDANCE...INTERESTING TO SEE THE VARIOUS DEPICTIONS OF THE
AFTN/EVE CONVECTIVE POTENTIAL FOR THE CWA. RECENT HRRR RUNS
CONTINUE TO DO WHAT SEEMS MOST PLAUSIBLE FOR AT LEAST THE FIRST
HALF OF THE DAY...PASSING THE CURRENT WV ACTIVITY DOWN ACROSS SWRN
VA AND JUST S OF THE SRN TIER CWA COUNTIES/I-64 CORRIDOR. ONLY
ISOLATED SHOWER AND WEAK TSTM ACTIVITY THEN DEVELOPS ACROSS THE
REST OF THE CWA DURING THE AFTN-EARLY EVE HRS. THE NRN FLANK OF
THE WAVE THEN REINVIGORATES SOME CONVECTION ACROSS NERN MD TOWARD
THE LATE EVE HRS.

PASSING BATCHES OF CIRRUS DEBRIS THIS MRNG INDICATE THAT EVEN W/
SOME INSTABILITY...THERE ARE ENOUGH PREVENTATIVE LAYERS IN THE
ATMOS TO HOLD OFF TSTMS UNTIL A BOUNDARY PASSES THRU AND ACTS ON
THE BUILDING MOISTURE/INSTABILITY. UNMODIFIED 12Z KIAD SNDG HAS
AROUND 1500 J/KG CAPE AVAILABLE W/ A COUPLE OF HEFTY INVERSIONS
BUT CERTAINLY AMENABLE TO DISSIPATING IF THE INCOMING SHORTWAVE
CAN COOL OFF THESE LEVELS IN A SHORT AMNT OF TIME. THE KEY TO
CONVECTIVE POTENTIAL AND STRENGTH THIS AFTN ANYWHERE IN THE AREA
WILL BE LOW LEVEL AND SMALL-SCALE BOUNDARY INTERACTION. THE SHEAR
PROFILES ARE NOT FAVORABLE SO THE INITIATION AND CONTINUATION WILL
BE ON THE SHOULDERS OF OUTFLOW BOUNDARIES AND THE DYNAMIC FORCING
OF THE SHORTWAVE ITSELF.

FROM PREV DISC...
POPS WERE KEPT LOW DUE TO THESE UNCERTAINTIES. ALSO DELAYED
MENTION OF SHOWERS OR STORMS FOR THE I-95 CORRIDOR UNTIL THE EVE
PERIOD BASED ON THE TIMING OF THE TROUGH. WITH SO MANY OUTDOOR
ACTIVITIES PLANNED FOR THE HOLIDAY WEEKEND...WE WANT PEOPLE TO PAY
EXTRA ATTENTION TO THE FCST.

SHOWERS AND STORMS SHOULD DIMINISH AFTER SUNSET WITH THE LOSS OF
HEATING. MOST IF NOT ALL OF THIS ACTIVITY SHOULD END BY THE OVNGT AS
THE SHORTWAVE TROUGH MOVES EAST OF THE CHSPK BAY. PATCHY FOG MAY
DEVELOP OVNGT IN AREAS THAT RECEIVE RAIN TDA AND WHERE SKIES CLEAR.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
PARADE OF SHORTWAVES WILL CONTINUE ON SUNDAY...WITH SFC TROUGHING
EXPECTED TO DEVELOP IN THE LEE OF THE BLUE RIDGE. THIS
COMBINATION...ALONG WITH COPIOUS MOISTURE /PWATS APPROACHING TWO
INCHES/ SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF NUMEROUS SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING. WENT WITH
LIKELY POPS IN MOST AREAS EAST OF THE BLUE RIDGE. CONVECTION MAY
PRODUCE LOCALLY HEAVY RAIN...BUT PROPAGATION OF STORMS IS LIKELY TO
PRECLUDE A WIDESPREAD FLOOD THREAT.

ACTIVITY SHOULD WANE WITH SUNSET SUNDAY NIGHT...HOWEVER...MODELS
KEEP A MOIST AIRMASS IN PLACE AND SHOW A SHORTWAVE PASSING NORTH OF
THE AREA. IT IS CLOSE ENOUGH TO KEEP AT LEAST SMALL POPS IN THE
FORECAST ALL NIGHT. WILL DEFINITELY BE A WARM AND HUMID NIGHT.

LABOR DAY IS CONSIDERED THE UNOFFICIAL END OF SUMMER. UNLIKE
MEMORIAL DAY...WHICH FELT ANYTHING BUT SUMMERLIKE...LABOR DAY SHOULD
BE PLENTY HOT AND HUMID WITH GOOD CHANCES FOR SHOWERS AND STORMS AS
SFC TROUGHING REMAINS IN PLACE...AND A COLD FRONT APPROACHES FROM
THE WEST. NOT QUITE CONFIDENT ENOUGH TO CARRY LIKELY POPS YET. IF
THERE ARE BREAKS IN THE CLOUDS...HIGHS COULD REACH THE LOWER
90S...BUT WILL HOLD GRIDS IN THE UPPER 80S GIVEN EXPECTED CLOUDS.
FROPA IS EXPECTED MONDAY NIGHT OVER MOST...IF NOT ALL...OF THE AREA.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ALTHOUGH LINGERING SHOWERS CANNOT BE RULED OUT ON TUESDAY...I
LIMITED CHANCES TO THE FAR SE AND MARINE ZONES. HIGHS 5 TO 10
DEGREES COOLER THAN MONDAY. THE STRENGTH OF THE COOL AIRMASS BEHIND
THE FRONT REMAINS IN QUESTION...AND WILL ERR ON THE WARMER SIDE FOR
TUESDAY AND WEDNESDAY. A REINFORCING FRONT PUSHES THROUGH...LIKELY
DRY...ON THURSDAY. PRECIP CHANCES MAY RETURN BY NEXT WEEKEND WITH
ONSHORE FLOW FORECAST TO DEVELOP.

&&

.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS TDA...ALTHOUGH A BRIEF REDUCTION IN VSBY POSSIBLE
LATE THIS AFTN AND EVE AS SCT SHRA/TSRA MOVE THRU. CHANCES FOR
PRECIP TOO LOW THRU 18Z TO INCLUDE A VCTS IN THE TAFS. THERE IS
MORE UNCERTAINTY IF THIS ACTIVITY MAKES IT FARTHER EAST TOWARD THE
I-95 TERMINALS.

PATCHY FOG MAY DEVELOP AGAIN TNGT...ESPECIALLY AT TERMINALS THAT
RECEIVE APPRECIABLE RAINFALL TDA.

SCTD TO NUMEROUS SHRA/TSRA EXPECTED EACH AFTN/EVENING SUNDAY AND
MONDAY. HEAVY RAIN IN SOME CONVECTION COULD CREATE VSBY RESTRICTIONS
AT TIMES. FROPA ON MONDAY NIGHT SHOULD YIELD GENERALLY VFR
CONDITIONS AFTER THAT THROUGH MIDWEEK.

&&

.MARINE...
SLY CHANNELING HAS PRODUCED 20 KT GUSTS IN THE CHSPK BAY. WITH
HIPRES PARKED OFFSHORE...THE PRESSURE GRADIENT WILL REMAIN STRONG
ENOUGH TO YIELD A CONTINUATION OF THE SCA FOR THE CHSPK BAY AND
LOWER TIDAL POTOMAC INTO TNGT.

GUSTY WINDS WILL GRADUALLY SUBSIDE SUNDAY MORNING AS SLY CHANNELING
LESSENS AND WINDS TURN OUT OF THE SOUTHWEST. SCATTERED TO NUMEROUS
SHOWERS AND STORMS ARE EXPECTED SUNDAY AND MONDAY...MAINLY IN THE
AFTERNOON AND EVENING. A FRONTAL PASSAGE MONDAY NIGHT OR TUESDAY
MORNING WILL TURN WINDS OUT OF THE NORTH...BUT THE SYSTEM IS NOT
PARTICULARLY STRONG SO WINDS SHOULD REMAIN GENERALLY LIGHT.

&&

.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD ADVISORY CONTINUES FOR ANNE ARUNDEL COUNTY FOR
THE AFTN HT CYCLE. POSITIVE ANOMALIES ALONG THE WRN SHORE OF THE
MD CHSPK BAY HAVE REMAINED STEADY AROUND 1.25 FT SINCE YDA. WITH
SLY FLOW CONTINUING UP THE BAY...EXPECT THIS STEADY STATE TO
CONTINUE TDA. ANOMALIES OF THIS MAGNITUDE WILL BE ENOUGH TO
PRODUCE COASTAL FLOODING AT ANNAPOLIS THIS AFTN DESPITE IT BEING
THE LOWER OF THE TWO HIGH TIDE CYCLES. THEREFORE...A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR ANNE ARUNDEL COUNTY FOR THIS AFTN.

THE LATEST CBOFS DOES NOT SHOW FLOODING PROBLEMS FOR TNGT. AM NOT
SOLD ON THIS YET WITH SLY FLOW CONTINUING. WILL KEEP THE POTENTIAL
FOR ANOTHER ROUND OF MINOR COASTAL FLOODING W/ TNGT`S HIGH TIDE
CYCLE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY FROM NOON TODAY TO 4 PM EDT THIS
     AFTERNOON FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR ANZ530>534-537-
     539>541-543.

&&

$$
UPDATE...GMS
PREV DISCUSSION...JRK/JE









AREA FORECAST DISCUSSION

NWS BALTIMORE MD/WASHINGTON DC

 609 AM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFFSHORE THIS WEEKEND WHILE A SERIES OF
UPPER DISTURBANCES MOVE THROUGH THE AREA. A COLD FRONT WILL MOVE
THROUGH THE REGION MONDAY NIGHT. HIGH PRESSURE RETURNS MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
A LGT SLY RETURN FLOW HAS BEEN MAINTAINED OVNGT WITH HIPRES PARKED
OFF THE MID-ATLANTIC COAST. THIS LGT WINDS AND SCT CLOUDS HAVE
PREVENTED FOG DEVELOPMENT THUS FAR.

WE ARE MONITORING AN OVNGT COMPLEX OF STORMS OVER OH. THE MID-LVL
SHORTWAVE TROUGH ASSOCIATED WITH THIS REMNANT MCS IS FCST TO
PROGRESS E-SE TDA...REACHING THE CENTRAL APPALACHIANS BY MID
AFTN. THE LATER TIMING IN THE DAY OF THIS DISTURBANCE WILL ALLOW
FOR THE ATMOSPHERE TO DESTABILIZE ACROSS THE REGION AS TEMPS REACH
THE MID TO UPPER 80S FOR HIGHS. AS EVIDENT FROM THE 00Z RAOB
SOUNDINGS UPSTREAM OF THE AREA...A SIGNIFICANT MID-LVL INVERSION
WILL REACH OUR AREA THIS MRNG AND INITIALLY PROVIDE A LID FOR DEEP
CONVECTION TO OVERCOME...WHICH MAY DELAY INITIATION OF SHOWERS AND
STORMS OVER THE MTS UNTIL THE MID TO LATE AFTN. FCST SOUNDINGS
FROM THE LATEST RAP INDICATE ABOUT 2000 J/KG OF SBCAPE AVAILABLE
FOR CONVECTION THIS AFTN. A WEAK WIND FIELD WILL LIMIT EXTENT OF
SEVERE STORMS TDA...BUT A FEW PULSE SEVERE STORMS ARE POSSIBLE
GIVEN THE FAVORABLE ENIVRONMENT FOR WET MICROBURSTS.

THERE IS HIGHER UNCERTAINTY IF CONVECTION BREAKS THE CAP TDA EAST
OF THE MTS. THE 00Z NAM AND A FEW NMM MEMBERS OF THE 21Z SREF
DEPICT A STRONGER SHORTWAVE TROUGH MOVING THRU THIS AFTN...
ALLOWING THE MID-LVL CAP TO ERODE FASTER AND SHOWER/STORMS TO
DEVELOP FARTHER EAST INTO THE I-95 CORRIDOR DURING THE LATE AFTN.
MEANWHILE THE BULK OF OTHER OPERATIONAL MODEL GUIDANCE PROG A
WEAKER SHORTWAVE AND THUS A STRONGER SUBSIDENCE INVERSION...WHICH
WOULD INHIBIT ANY CONVECTION FROM DEVELOPING EAST OF THE MTS. POPS
WERE KEPT LOW DUE TO THESE UNCERTAINTIES. ALSO DELAYED MENTION OF
SHOWERS OR STORMS FOR THE I-95 CORRIDOR UNTIL THE EVE PERIOD BASED
ON THE TIMING OF THE TROUGH. WITH SO MANY OUTDOOR ACTIVITIES
PLANNED FOR THE HOLIDAY WEEKEND...WE WANT PEOPLE TO PAY EXTRA
ATTENTION TO THE FCST.

SHOWERS AND STORMS SHOULD DIMINISH AFTER SUNSET WITH THE LOSS OF
HEATING. MOST IF NOT ALL OF THIS ACTIVITY SHOULD END BY THE OVNGT AS
THE SHORTWAVE TROUGH MOVES EAST OF THE CHSPK BAY. PATCHY FOG MAY
DEVELOP OVNGT IN AREAS THAT RECEIVE RAIN TDA AND WHERE SKIES CLEAR.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
PARADE OF SHORTWAVES WILL CONTINUE ON SUNDAY...WITH SFC TROUGHING
EXPECTED TO DEVELOP IN THE LEE OF THE BLUE RIDGE. THIS
COMBINATION...ALONG WITH COPIOUS MOISTURE /PWATS APPROACHING TWO
INCHES/ SHOULD BE SUFFICIENT FOR THE DEVELOPMENT OF NUMEROUS SHOWERS
AND THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING. WENT WITH
LIKELY POPS IN MOST AREAS EAST OF THE BLUE RIDGE. CONVECTION MAY
PRODUCE LOCALLY HEAVY RAIN...BUT PROPAGATION OF STORMS IS LIKELY TO
PRECLUDE A WIDESPREAD FLOOD THREAT.

ACTIVITY SHOULD WANE WITH SUNSET SUNDAY NIGHT...HOWEVER...MODELS
KEEP A MOIST AIRMASS IN PLACE AND SHOW A SHORTWAVE PASSING NORTH OF
THE AREA. IT IS CLOSE ENOUGH TO KEEP AT LEAST SMALL POPS IN THE
FORECAST ALL NIGHT. WILL DEFINITELY BE A WARM AND HUMID NIGHT.

LABOR DAY IS CONSIDERED THE UNOFFICIAL END OF SUMMER. UNLIKE
MEMORIAL DAY...WHICH FELT ANYTHING BUT SUMMERLIKE...LABOR DAY SHOULD
BE PLENTY HOT AND HUMID WITH GOOD CHANCES FOR SHOWERS AND STORMS AS
SFC TROUGHING REMAINS IN PLACE...AND A COLD FRONT APPROACHES FROM
THE WEST. NOT QUITE CONFIDENT ENOUGH TO CARRY LIKELY POPS YET. IF
THERE ARE BREAKS IN THE CLOUDS...HIGHS COULD REACH THE LOWER
90S...BUT WILL HOLD GRIDS IN THE UPPER 80S GIVEN EXPECTED CLOUDS.
FROPA IS EXPECTED MONDAY NIGHT OVER MOST...IF NOT ALL...OF THE AREA.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ALTHOUGH LINGERING SHOWERS CANNOT BE RULED OUT ON TUESDAY...I
LIMITED CHANCES TO THE FAR SE AND MARINE ZONES. HIGHS 5 TO 10
DEGREES COOLER THAN MONDAY. THE STRENGTH OF THE COOL AIRMASS BEHIND
THE FRONT REMAINS IN QUESTION...AND WILL ERR ON THE WARMER SIDE FOR
TUESDAY AND WEDNESDAY. A REINFORCING FRONT PUSHES THROUGH...LIKELY
DRY...ON THURSDAY. PRECIP CHANCES MAY RETURN BY NEXT WEEKEND WITH
ONSHORE FLOW FORECAST TO DEVELOP.

&&

.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
PATCHY FOG POSSIBLE AT CHO...WITH MVFR VSBYS AROUND SUNRISE. VFR
CONDITIONS TDA...ALTHOUGH A BRIEF REDUCTION IN VSBY POSSIBLE LATE
THIS AFTN AND EVE AS SCT SHRA/TSRA MOVE THRU. CHANCES FOR PRECIP TOO
LOW THRU 18Z TO INCLUDE A VCTS IN THE TAFS. THERE IS MORE
UNCERTAINTY IF THIS ACTIVITY MAKES IT FARTHER EAST TOWARD THE I-95
TERMINALS.

PATCHY FOG MAY DEVELOP AGAIN TNGT...ESPECIALLY AT TERMINALS THAT
RECEIVE APPRECIABLE RAINFALL TDA.

SCTD TO NUMEROUS SHRA/TSRA EXPECTED EACH AFTN/EVENING SUNDAY AND
MONDAY. HEAVY RAIN IN SOME CONVECTION COULD CREATE VSBY RESTRICTIONS
AT TIMES. FROPA ON MONDAY NIGHT SHOULD YIELD GENERALLY VFR
CONDITIONS AFTER THAT THROUGH MIDWEEK.

&&

.MARINE...
SLY CHANNELING HAS PRODUCED 20 KT GUSTS IN THE CHSPK BAY. WITH
HIPRES PARKED OFFSHORE...THE PRESSURE GRADIENT WILL REMAIN STRONG
ENOUGH TO YIELD A CONTINUATION OF THE SCA FOR THE CHSPK BAY AND
LOWER TIDAL POTOMAC INTO TNGT.

GUSTY WINDS WILL GRADUALLY SUBSIDE SUNDAY MORNING AS SLY CHANNELING
LESSENS AND WINDS TURN OUT OF THE SOUTHWEST. SCATTERED TO NUMEROUS
SHOWERS AND STORMS ARE EXPECTED SUNDAY AND MONDAY...MAINLY IN THE
AFTERNOON AND EVENING. A FRONTAL PASSAGE MONDAY NIGHT OR TUESDAY
MORNING WILL TURN WINDS OUT OF THE NORTH...BUT THE SYSTEM IS NOT
PARTICULARLY STRONG SO WINDS SHOULD REMAIN GENERALLY LIGHT.

&&

.TIDES/COASTAL FLOODING...
THE COASTAL FLOOD ADVISORY CONTINUES FOR THE WRN BAY COUNTIES IN
CENTRAL MD. HIGH TIDE HAS PASSED IN ANNE ARUNDEL AND BALTIMORE
COUNTIES...BUT ANNAPOLIS IS STILL IN FLOOD STAGE. HIGH TIDE AT
HAVRE DE GRACE OCCURS JUST AFTER SUNRISE.

POSITIVE ANOMALIES ALONG THE WRN SHORE OF THE MD CHSPK BAY HAVE
REMAINED STEADY AROUND 1.25 FT SINCE YDA. WITH SLY FLOW CONTINUING
UP THE BAY...EXPECT THIS STEADY STATE TO CONTINUE TDA. ANOMALIES
OF THIS MAGNITUDE WILL BE ENOUGH TO PRODUCE COASTAL FLOODING AT
ANNAPOLIS THIS AFTN DESPITE IT BEING THE LOWER OF THE TWO HIGH
TIDE CYCLES. THEREFORE...A COASTAL FLOOD ADVISORY HAS BEEN ISSUED
FOR ANNE ARUNDEL COUNTY FOR THIS AFTN.

THE LATEST CBOFS DOES NOT SHOW FLOODING PROBLEMS FOR TNGT. AM NOT
SOLD ON THIS YET WITH SLY FLOW CONTINUING. WILL KEEP THE POTENTIAL
FOR ANOTHER ROUND OF MINOR COASTAL FLOODING W/ TNGT`S HIGH TIDE
CYCLE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...COASTAL FLOOD ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MDZ007-
     011-014.
     COASTAL FLOOD ADVISORY FROM NOON TODAY TO 4 PM EDT THIS
     AFTERNOON FOR MDZ014.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT SUNDAY FOR ANZ530>534-537-
     539>541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
     ANZ536-538.

&&

$$
SYNOPSIS...JRK
NEAR TERM...JRK
SHORT TERM...JCE
LONG TERM...JCE
AVIATION...JCE/JRK
MARINE...JCE/JRK
TIDES/COASTAL FLOODING...JRK








AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 743 PM EDT SUN SEP 1 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 401 PM EDT SUN SEP 1 2013

12Z ROABS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PAIR OF VIGOROUS
SHRTWVS DIGGING THRU ONTARIO/LK SUP IN THE NW FLOW ALF BTWN RDG OVER
THE ROCKIES AND A TROF OVER ERN NAMERICA. WHILE DRYING ALF UNDER
DNVA/UPR CONFLUENCE/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE MOST
IMPRESSIVE SHRTWV MOVING ACRS NRN LK SUP HAS ENDED THE SHRA OVER THE
SW CWA...MORE NMRS SHRA/TS IN THE COMMA TAIL IN ADVANCE OF RATHER
WEAK ATTENDANT COLD FNT...WHERE RUC ANALYSIS SHOWS KINX NOT FAR FM
40/STEEPER MID LVL LAPSE RATES/MUCAPE IN THE 500-1000J/KG RANGE...
ARE  MOVING THRU THE ERN ZNS. MORE NMRS SHRA/TS ALSO IMPACTED THE
KEWEENAW EARLIER IN THE DAY CLOSER TO THE COMMA HEAD ASSOCIATED WITH
THIS SHRTWV. THE MAIN HAZARD FM ALL THE SHRA/TS HAVE BEEN HEAVY
DOWNPOURS...WHICH PROMPTED THE ISSUANCE OF AN URBAN/SMALL STREAM
FLOOD ADVY FOR THE KEWEENAW EARLIER IN THE AFTN FOLLOWING A REPORT
OF 2 INCHES OF RA IN AN HOUR NEAR CALUMET. EVEN THOUGH THERE HAS
BEEN DRYING ALF OVER THE W IN THE WAKE OF THE WEAK SFC COLD
FROPA...A FEW -SHRA HAVE DVLPD IN THIS AREA ALONG WITH SOME LO CLDS
AS LLVL MSTR SHOWN ON THE 12Z INL RAOB HAS OVERSPREAD THE AREA IN
THE NW LLVL FLOW IN THE WAKE OF THE SHRTWV. LARGE SCALE QVECTOR
DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING SHRTWV HAVE TENDED TO
LIMIT THE INTENSITY OF THESE -SHRA. THERE IS A SHARPER SURGE OF COOL
AIR ASSOCIATED WITH THE SECOND SHRTWV DROPPING SSEWD IN NW ONTARIO.
LO CLDS ARE WIDESRPEAD TO THE NW OF LK SUP WITH SOME -RA/-DZ
REPORTED IN THE CYC FLOW ON THE NW FLANK OF SFC LO PRES MOVING THRU
LK SUP THAT ASSOCIATED WITH THE FIRST SHRTWV.

REST OF THIS AFTN/TNGT...EXPECT LINGERING SHRA/TS OVER THE ERN ZNS
LATE THIS AFTN TO SHIFT TO THE E FOLLOWING DEPARTURE OF AXIS OF HIER
RH/DEEP LYR QVECTOR CNVGC AND UNDER DEEP LYR QVECTOR DVGC BEHIND
DEPARTING FIRST SHRTWV. FOLLOWING THE PASSAGE OF REINFORCING COLD
FNT EARLY THIS EVNG ASSOCIATED WITH THE SECOND SHRTWV DIGGING THRU
ONTARIO...EXPECT WIDESPREAD LO CLD/SOME -DZ TO DVLP ESPECIALLY IN
THE UPSLOPE AREAS NEAR LK SUP AS LLVL NNW FLOW DRIVES NEAR SFC COOL
AIR INTO THE AREA AND SHARPENS INVRN BASE NEAR H9 AS SHOWN ON 12Z
LOCAL WRF ARW FCST SDNGS. THE COMBINATION OF GUSTY WINDS WITH H925
WINDS FCST UP TO 25-30 KTS AND THE ARRIVAL OF THE COOLER AIR WL MAKE
THE NGT FEEL QUITE CHILLY AS COMPARED TO THE WARM WX IN RECENT WEEKS.

LABOR DAY...MON WL FEATURE A CONFLUENT NW FLOW OVER THE UPR LKS/DEEP
LYR QVECTOR DVGC. MAIN FCST CONCERN IS HOW QUICKLY LO CLDS/-DZ WITH
SHALLOW MOIST LYR BLO SHARP LLVL INVRN WL DEPART. GIVEN THE
INTENSITY OF THE DISTURBANCES IN PLAY TODAY...PREFERRED TO FOLLOW
THE 12Z LOCAL WRF-ARW FCST SCENARIO...WHICH SHOWS MORE PERSISTENT
LLVL MSTR MAINTAINED BY STRONGER N WIND. BUT EVEN THIS MODEL
INDICATES SOME IMPROVEMENT IN THE AFTN ESPECIALLY OVER THE W HALF
WITH CLOSER APRCH OF SFC HI PRES/WEAKER AND MORE ACYC FLOW. EXPECT
THE RETURN OF AT LEAST SOME SUNSHINE IN THAT AREA AFT 18Z. TEMPS WL
RUN BLO NORMAL FOR THE FIRST TIME IN QUITE AWHILE.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 401 PM EDT SUN SEP 1 2013

QUITE A TRANQUIL PERIOD OF WEATHER EXPECTED OVER THE NEXT WEEK AS
LARGE SCALE FEATURES TREND BACK TO THE EARLY SUMMER SET-UP OF A
WESTERN RIDGE AND EASTERN TROUGH. TEMPERATURES SHOULD BE AT TO
SLIGHTLY ABOVE NORMAL THROUGH THE WEEK.

MONDAY NIGHT THROUGH TUESDAY NIGHT...A STRONG MID-LEVEL SHORTWAVE
TROUGH AND AN ACCOMPANYING SFC LOW WILL BE OVER THE SOUTHEAST
ONTARIO AND QUEBEC BORDER AT THE START OF THE PERIOD...AND WILL BE
CONTINUING TO MOVE EAST MONDAY NIGHT. MEANWHILE...MID-LEVEL RIDGING
WILL BE BUILDING INTO THE UPPER MS VALLEY AS A SFC HIGH PRESSURE
SETTLES OVER OVER NW TO CENTRAL WI. MAIN QUESTIONS IN THIS TIME
FRAME REVOLVE AROUND DEPARTING LOW CLOUD COVER IN THE EAST...AND MIN
TEMPS FOR THE WEST.

INCREASINGLY DRIER AIR WILL CONTINUE ADVECTING INTO THE REGION FROM
THE NW AHEAD OF THE SFC HIGH. ATTM...IT APPEARS THAT LOW-CLOUDS
UNDER AN H8 INVERSION SHOULD DISSIPATE ENOUGH FROM INSOLATION AND
INCOMING DRY AIR TO RESULT IN MOSTLY CLEAR SKIES FOR THE WEST HALF.
THE EAST HALF IS A BIT MORE TRICKY...WITH THE NAM NON-SURPRISINGLY
KEEPING LOW STRATUS ACROSS THE AREA WELL INTO THE OVERNIGHT HOURS.
OVERALL...FEELING IS THAT CLOUDS WILL CLEAR OUT BY MIDNIGHT FOR THE
EAST.

WITH THE GRADIENT FLOW WEAKENING ACROSS THE WEST...AND PWAT VALUES
AROUND 0.5 INCHES...GOOD RADIATIONAL COOLING IS EXPECTED. HAVE
FORECAST TEMPS IN THE LOW 40S INTERIOR WEST...WITH EVEN A COUPLE
POCKETS OF UPPER 30S. LOWS SHOULD REMAIN AROUND 50 ALONG THE GREAT
LAKES...AND ACROSS THE EAST HALF WHERE GRADIENT FLOW REMAINS
STRONGER THROUGHOUT THE NIGHT.

BROAD RIDGING MOVES ACROSS THE UPPER GREAT LAKES ON TUESDAY...AND
WILL BRING SUNNY SKIES WITH TEMPS WARMING TO THE MID 70S. RETURN
FLOW ON THE BACKSIDE OF THE SFC HIGH ALONG WITH INCREASING MID-LEVEL
CLOUDS SHOULD KEEP TEMPS FROM FALLING OFF TOO MUCH TUESDAY...WITH
COLDEST LOWS ONLY IN THE UPPER 40S. PLENTY OF DRY AIR ABOVE THE
INVERSION SHOULD ALLOW RH VALUES TO FALL INTO THE MID 30S TO AROUND
40 FOR INTERIOR LOCATIONS...THOUGH WINDS WILL BE QUITE LIGHT.

WEDNESDAY...A STRENGTHENING SHORTWAVE ACROSS NORTHERN CANADA WILL
QUICKLY TRACK SOUTHEAST ACROSS NORTHERN MANITOBA ON TUESDAY...AND
SOUTHERN HUDSON BAY TUESDAY NIGHT INTO WEDNESDAY MORNING. AN
ASSOCIATED STRENGTHENING SFC LOW WILL SEND A COLD FRONT FROM NORTH
TO SOUTH ACROSS THE CWA LATE TUESDAY NIGHT INTO WEDNESDAY. NEARLY
ALL FORCING BY WAY OF MID-LEVEL Q-VECTOR CONVERGENCE WILL STAY WELL
NORTH AND EAST OF THE AREA. GIVEN LIMITED MOISTURE WITH THIS
SYSTEM...DO NOT EXPECT ANYTHING MORE THAN SOME SCATTERED TO BROKEN
MID-LEVEL CLOUDINESS. ONE EXCEPTION COULD BE A BRIEF BOUT OF
POST-FRONTAL UPSLOPE DRIZZLE ACROSS THE NORTH-CENTRAL CWA...BUT WITH
DRY AIR MOVING IN QUICKLY BEHIND THE FRONT...LEFT OUT OF THE FCST
FOR NOW.

THE ECMWF HAS BEEN ON THE FASTER END OF GUIDANCE WITH THE PASSAGE OF
THE FRONT...CLEARING MUCH OF THE CWA BY NOON. THE GFS HAD BEEN
SEVERAL HOURS SLOWER...NOT CLEARING THE CWA UNTIL MID TO LATE
AFTERNOON. HOWEVER...IT HAS TRENDED 3 TO 5 HOURS QUICKER OVER THE
LAST SEVERAL RUNS...AND NOW LINES UP MUCH BETTER WITH THE ECMWF.
WILL FOLLOW THE IDEA OF A QUICKER FRONTAL PASSAGE. STRENGTHENING
HIGH PRESSURE TRACKING SOUTHEASTWARD INTO THE UPPER MS VALLEY BEHIND
THE FRONT WILL INDUCE A MODEST ISALLOBARIC WIND COMPONENT AND BRING
A WINDOW OF BREEZY CONDITIONS WEDNESDAY MORNING...PRODUCING AN
ELEVATED SWIM RISK FOR WEDNESDAY.

WEDNESDAY NIGHT THROUGH SUNDAY...HIGH PRESSURE WILL SETTLE OVER THE
AREA WEDNESDAY NIGHT AND ALLOW TEMPS TO ONCE AGAIN FALL WELL INTO
THE 40S FOR INTERIOR LOCATIONS. DEEP TROUGHING IN THE WEST WILL
DEVELOP BY LATE IN THE WEEK AND DOMINATE THE PATTERN ACROSS THE NE
CONUS. A COUPLE OF WEAK SHORTWAVES WILL TRACK ALONG THE BACKSIDE OF
THIS TROUGH AND AFFECT THE CWA. TIMING AND STRENGTH ARE TYPICALLY
DIFFICULT TO PIN DOWN IN THIS TYPE OF FLOW REGIME...SO WILL USE
CONSENSUS FORECAST THROUGH THE WEEKEND. WITH THAT SAID...BEST CHANCE
TO SEE SOME ISOLATED SHOWERS AND A FEW THUNDERSTORMS WILL BE FRIDAY
AND FRIDAY NIGHT AS A COLD FRONT DROPS SOUTH THROUGH THE REGION.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 743 PM EDT SUN SEP 1 2013

LOW MVFR CONDITIONS AT KCMX/KSAW WILL FALL TO IFR OVER THE NEXT FEW
HRS UNDER GUSTY UPSLOPE NNW WIND. SOME -DZ/SPRINKLES ARE LIKELY AS
WELL. AT KIWD...UPSTREAM CONDITIONS SUGGEST CIGS MAY NOT FALL TO IFR
THERE...ALTHOUGH SOME -DZ/SPRINKLES MAY ALSO OCCUR. AS DISTURBANCE
RESPONSIBLE FOR THE GUSTY NNW WINDS/LOW-LEVEL MOISTURE CONTINUES TO
SHIFT E...EXPECT GRADUALLY IMPROVING CONDITIONS FROM W TO E LATE
TONIGHT AND MON. IN FACT...SKIES SHOULD CLEAR AT KCMX/KIWD MID AFTN.
IT MAY NOT BE UNTIL LATE AFTN/EARLY EVENING THAT CLOUDS SCATTER OUT
AT KSAW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EDT SUN SEP 1 2013

FOLLOWING A COLD FRONTAL PASSAGE LATE THIS AFTERNOON/EARLY
EVENING...EXPECT NNW WINDS UP TO 30 KTS TO DEVELOP OVER THE LAKE AND
CONTINUE INTO MON...WHEN A HI PRES APPROACHING THE UPPER LAKES WILL
CAUSE THE WINDS TO DIMINISH WEST-TO-EAST THRU MON NIGHT. LOOK FOR
LIGHTER WINDS ON TUE AS THE HI PRES MOVES OVER THE UPPER LAKES.
STRONGER NNW WINDS UP TO 25 KTS WILL DEVELOP OVER THE E HALF ON WED
FOLLOWING ANOTHER COLD FRONTAL PASSAGE. THEN WINDS SHOULD DIMINISH
QUICKLY THE REST OF THE WEEK AS ANOTHER HI PRES/WEAK PRES GRADIENT
MOVE OVER THE LAKE.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  BEACH HAZARDS STATEMENT THROUGH LATE MONDAY NIGHT FOR MIZ005-006.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...KC







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 402 PM EDT SAT AUG 31 2013

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 359 PM EDT SAT AUG 31 2013

MAIN FCST CONCERNS IN THE SHORT TERM INVOLVE SHRA/TS CHCS ASSOCIATED
WITH SHRTWV NOW NEAR LK WINNIPEG.

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE NRN CONUS ON THE NRN FLANK OF SPRAWLING HI PRES CENTERED OVER
THE SW CONUS. STUBBORN LO CLDS OVER THE SCENTRAL COUNTIES ARE
FINALLY BURNING OFF. THERE IS A SHRTWV TRACKING THRU ONTARIO...BUT
THIS DISTURBANCE IS PASSING FAR ENUF TO THE N THAT THE COMMA TAIL
-SHRA ARE JUST BRUSHING NEAR ISLE ROYALE. WEAK RDG OF HI PRES OVER
THE GRT LKS/SHARP SUBSIDENCE INVRN SHOWN ON LOCAL 12Z RAOBS IS
BRINGING QUIET WX TO THE CWA FOR NOW. A STRONGER SHRTWV IS PRESENT
ALONG THE NDAKOTA/CNDN BORDER AND MOVING QUICKLY TO THE ESE. WHERE
THE SHARP DPVA/DEEP LYR QVECTOR CNVGC IN ADVANCE OF THIS FEATURE IS
OVERSPREADING AXIS OF HIER MUCAPE/H85 THETA E AHEAD OF ATTENDANT
COLD FNT...NMRS SHRA/TS ARE BREAKING OUT IN MN.

TNGT...SHRTWV JUST SW OF LK WINNIPEG IS PROGGED TO MOVE ESE AND OVER
NCENTRAL LK SUP BY 12Z SUN. AS THE DPVA/DEEP LYR QVECTOR CNVGC AND
AXIS OF HIER INSTABILITY/H85 THETA E MOVE INTO WRN LK SUP THIS
EVNG...EXPECT SHRA/TS NOW OVER MN TO SHIFT INTO THE WRN LAND CWA BY
06Z. GIVEN FCST MUCAPE IN EXCESS OF 1000 J/KG...SFC-6KM SHEAR IN THE
40-50KT RANGE /FORTUNATELY THE STORMS WL BECOME ELEVATED SO THIS WL
NOT BE THE EFFECTIVE LYR SHEAR/...AND FAIRLY SHARP LLVL CNVGC ALONG
ATTENDANT COLD FNT...SOME OF THESE STORMS MAY BE STRONG. BUT WITH
LOSS OF DAYTIME HEATING AND WEAKENING H85 THETA E AXIS...EXPECT THE
INTENSITY OF THESE SHRA/TS TO DIMINISH AS THEY SPREAD INTO CENTRAL
UPR MI LATE. IN FACT...THE MOST RECENT SPC CONVECTIVE OUTLOOK THRU
12Z SUN CONFINES THE SLGT RISK FOR SVR TS TO MN AND FAR WRN LK SUP.
WHERE TEMPS HAVE A CHC TO COOL DOWN A BIT OVER THE E HALF BEFORE THE
ARRIVAL OF CLDS/A BIT SHARPER PRES GRADIENT...ADDED PATCHY FOG WITH
EXPECTATION THAT MIN TEMPS FALLING INTO THE UPR 50S WL FALL THRU THE
CROSSOVER DEWPT OBSVD THIS AFTN.

SUN...AS SHRTWV OVER NCENTRAL LK SUP IN THE MRNG SHIFTS INTO SE
ONTARIO IN THE AFTN...DNVA/DEEP LYR QVECTOR DVGC/VIGOROUS NEGATIVE
H85 THETA E ADVCTN IS FCST TO ARRIVE W-E FOLLOWING ATTENDANT COLD
FROPA. EXPECT BAND OF SHRA/TS AHD OF COLD FNT TO SHIFT FM THE CNTRL
ZNS INTO THE ERN ZNS DURING THE MRNG. SHRA/TS INTENSITY MAY PICK UP
OVER THE FAR ERN CWA IN THE EARLY AFTN WITH IMPACT OF DAYTIME
HEATING LIFTING MUCAPE TO 500-1000 J/KG AND DEEP LYR SHEAR 30 TO 40
KTS BEFORE THE MORE ROBUST QVECTOR DVGC ARRIVES IN THE AFTN AND
BEGINS TO SUPPRESS THE CONVECTION WITH STRENGTHENING INVRN FOLLOWING
COLD FROPA AT ERY NEAR 21Z. THIS THREAT WOULD BE GREATER IF THE
SOMEWHAT SLOWER GFS VERIFIES...BUT THE PRESENT STEADY SPEED OF
SHRTWV INDICATES THE FASTER MODEL FCSTS ARE ON THE RIGHT TRACK.
FOLLOWING THE COLD FROPA AND ARRIVAL OF LLVL COOLER AIR...NAM FCST
SDNGS SHOW SHARPENING LLVL INVRN/PROSPECT FOR LO CLDS AND SOME
SPRINKLES...ESPECIALLY OVER THE W AND NCENTRAL WITH UPSLOPE NW FLOW.
SFC TEMPS MAY ACTUALLY FALL AT THESE PLACES DURING THE AFTN.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 359 PM EDT SAT AUG 31 2013

MORE SEASONABLE WEATHER IS EXPECTED THROUGH MUCH OF THE UPCOMING
WEEK...WITH CHANCES OF PRECIPITATION MONDAY AND AGAIN WEDNESDAY.

SUNDAY NIGHT AND MONDAY...A STRONG AND SHARP MID-LEVEL SHORTWAVE
OVER NE LAKE SUPERIOR WILL BE STARTING TO EXIT TO THE EAST AT THE
START OF THE PERIOD. THE ASSOCIATED SFC LOW WILL ALSO BE TRACKING
EASTWARD AWAY FROM EASTERN LAKE SUPERIOR. THE MAIN FORECAST CONCERN
IS HOW LONG MOISTURE WILL LINGER BEHIND THIS SYSTEM...AND HOW
WIDESPREAD UPSLOPE DRIZZLE/SHOWERS WILL BE. WITH PLENTY OF LOW-LEVEL
MOISTURE WRAPPING BEHIND THE LOW...EXPECT PLENTY OF DRIZZLE AND
LIGHT SHOWERS FOR ANY AREA EXPOSED TO NNW WINDS OFF LAKE SUPERIOR.
SUBSIDENCE WILL LOWER INVERSION HEIGHTS TO AROUND 1KM ACROSS THE
AREA...SO THE SATURATED LAYER WILL BE QUITE SHALLOW. INSOLATION ON
MONDAY SHOULD BE STRONG ENOUGH TO START ERODING THIS MOIST LAYER
MONDAY MORNING. INCREASINGLY DRIER AIR ADVECTING IN FROM WESTERN
ONTARIO SHOULD THEN REMOVE REMAINING CLOUDS/PRECIP FROM WEST TO EAST
THROUGHOUT MONDAY AFTERNOON.

HAVE INCREASED WINDS SEVERAL KNOTS ACROSS THE EAST HALF OF THE CWA
GIVEN A 1020MB SFC HIGH IN THE UPPER MS VALLEY IMPINGING ON THE
BACKSIDE OF THE DEPARTING 1002MB LOW. COULD SEE QUITE A BREEZY DAY
FOR MUCH OF THE AREA...WITH WINDS GUSTING OVER 30MPH RIGHT NEAR THE
LAKE SUPERIOR SHORE FROM BIG BAY EASTWARD. WILL CONTINUE TO RAMP UP
WORDING ON A HIGH SWIM RISK GIVEN THE LABOR DAY HOLIDAY.

MONDAY NIGHT...AS THE SFC HIGH SETTLES OVER NORTHERN WI MONDAY
NIGHT...CLEAR SKIES AND LOW PWAT VALUES OF LESS THAN 0.5 INCHES WILL
ALLOW FOR GOOD RADIATIONAL COOLING. HAVE MAINTAINED PREVIOUS
FORECAST TEMPS OF LOW 40S INTERIOR WEST HALF TO LOW 50S NEAR THE
GREAT LAKES. RESIDUAL STRONGER NW GRADIENT FLOW ACROSS THE EAST HALF
SHOULD LIMIT COOLING TO SOME EXTENT.

TUESDAY THROUGH THURSDAY...A SHORTWAVE TROUGH CURRENTLY TRACKING
EASTWARD ALONG THE ALLUETIAN ISLANDS WILL STALL OVER WESTERN ALASKA
AND SEND A SERIES OF WEAK WAVES ACROSS WESTERN CANADA. THE MAIN WAVE
OF INTEREST WILL BECOME AMPLIFIED BY ANOTHER STRONGER WAVE OVER THE
NORTH SLOPE OF ALAKSA. TIMING AND STRENGTH OF THIS FEATURE HAVE BEEN
UNDERSTANDABLY DIFFICULT FOR THE MODELS TO PIN DOWN. THE GFS HAS
WAVERED IN STRENGTH OVER THE LAST SEVERAL RUNS...WITH THE LATEST TWO
RUNS INDICATING A SLOWER AND WETTER SOLUTION. THIS IS LIKELY A
RESULT OF A LONGER PRECEEDING PERIOD OF LOW-LEVEL MOISTURE RETURN.
THE GEM IS THE QUICKEST SOLUTION OF THE THREE. HAVE OPTED TO EMPLOY
THE ECMWF FOR THE REST OF THE FORECAST GIVEN ITS MIDDLE GROUND AND
CONTINUITY OVER THE LAST COUPLE DAYS.

THE MAIN MID-LEVEL AND SFC LOWS WILL TRACK WELL NORTH OF THE
CWA...POSSIBLY AS FAR NORTH AS SOUTHERN HUDSON BAY. THE 990MB SFC
LOW DEPICTED BY THE ECMWF WILL BE STRONG ENOUGH TO SEND A POTENT
COLD FRONT SSE-WARD ACROSS THE CWA WEDNESDAY MORNING.
HOWEVER...THERE WILL BE A SUBSTANTIAL AMOUNT OF DRY AIR WITH THIS
SYSTEM GIVEN ITS ORIGIN. WILL PLACE ONLY SLIGHT CHANCE POPS ACROSS
THE FAR NORTH AND EAST CLOSER TO THE STRONGEST FORCING VIA MID-LEVEL
Q-VECTOR CONVERGENCE AND THE LEFT EXIT OF A 120KT UPPER JET. MUCH OF
UPPER MI...ESPECIALLY THE SOUTHWEST...LOOKS TO BE UNDER SUBSIDENCE
FROM THE RIGHT ENTRANCE OF THE JET...AND MAY NOT EVEN SEE MUCH IN
THE WAY OF CLOUD COVER. MOST OF THE COOLER AIR BEHIND THE FRONT WILL
STAY EAST OF THE AREA...SO ONLY A SLIGHTLY COOLER DAY THAN WEDNESDAY
IS EXPECTED FOR THURSDAY.

FRIDAY AND SATURDAY...BESIDE DEVELOPING THE IDEA OF DEEPER TROUGHING
ACROSS EASTERN CANADA...MODEL AGREEMENT ON SMALLER SCALE FEATURES IS
POOR BY THIS POINT IN THE FORECAST. THE GFS/GEM INDICATE STRONG SFC
HIGH PRESSURE BUILDING ACROSS THE AREA...WHILE THE ECMWF KEEP THE
HIGH MUCH FARTHER NE NEAR JAMES BAY. A WEAK SHORTWAVE DEPICTED BY
BOTH THE ECMWF AND GFS COULD BRING SHOWER CHANCES FOR FRIDAY...BUT
TIMING THE GFS IS SOMEWHAT SLOWER WITH THIS IDEA. EITHER WAY...VERY
LIMITED MOISTURE WILL PRECLUDE ANYTHING MORE THAN SPOTTY SHOWER
COVERAGE. HAVE OPTED TO MAINTAIN CONCENSUS FORECAST AT THIS POINT
GIVEN UNCERTAINTY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 120 PM EDT SAT AUG 31 2013

EXPECT DRY WX/VFR CONDITIONS THRU THIS EVNG WITH RELATIVELY DRY/
STABLE AIRMASS IN PLACE. BUT APRCH OF COLD FNT/MORE UNSTABLE AIRMASS
WL BRING THE THREAT OF SHRA AND PERHAPS SOME TS LATER TNGT...
ESPECIALLY AT CMX AND IWD. RETAINED MENTION OF VCTS AT THESE SITES.
FOLLOWING THE COLD FROPA LATE TNGT/EARLY SUN MRNG...EXPECT SOME LO
CLDS/IFR CONDITIONS TO IMPACT IWD AND CMX WITH UPSLOPE NW FLOW UNDER
STRENGTHENING SHARP INVRN.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT SAT AUG 31 2013

EXPECT SSW WINDS UP TO 20-25 KTS TONIGHT INTO SUN MORNING OVER THE E
HALF OF THE LAKE UNDER A SHARPENING PRES GRADIENT AHEAD OF AN
APPROACHING COLD FRONT. FOLLOWING THE PASSAGE OF THIS FRONT...THERE
WILL BE A WIND SHIFT TO THE NW...WITH WINDS INCREASING UP TO 25 KTS
IN THE AFTERNOON. THE COMBINATION OF DECREASING STABILITY WITH THE
ARRIVAL OF A COOL AIRMASS AND A SHARPENING PRES GRADIENT BETWEEN A
DEPARTING LO PRES SYSTEM AND AN APPROACHING HI WILL RESULT IN NW-N
WINDS UP TO 20-30 KTS ON SUN NIGHT INTO MON. THE ARRIVAL OF THE HI
AND WEAKER PRES GRADIENT WILL ALLOW WINDS TO DIMINISH UNDER 20 KTS
TUE THRU THU.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...KLUBER
AVIATION...KC
MARINE...KC







AREA FORECAST DISCUSSION

NWS TWIN CITIES/CHANHASSEN MN

 645 PM CDT SUN SEP 1 2013

.UPDATE...
FOR 00Z AVIATION DISCUSSION BELOW

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 250 PM CDT SUN SEP 1 2013

THE FACT THAT THE CALENDAR READ SEPTEMBER TOGETHER WITH THE SYNOPTIC
WEATHER PATTERN WERE EVIDENCE OF THE CHANGING SEASON IN STORE FOR
THE UPPER MIDWEST OVER THE NEXT COUPLE OF MONTHS. AS OF THIS
AFTERNOON THERE WAS A VAST AREA OF CLOUDS ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY. FORTUNATELY THE COLD STABLE AIR ACROSS THE
GREAT LAKES STILL YIELDED A FEW BREAKS OVER THE OPEN WATER AND WAS A
REMINDER THAT SUMMER IS STILL HOLDING ON. THE CHALLENGE FOR THE
FIRST PART OF THIS FORECAST IS THE EVOLUTION OF THE STRATUS DECK
THIS EVENING AND OVERNIGHT. EARLY AFTERNOON SATELLITE IMAGERY SHOWED
THE AFOREMENTIONED EXPANSIVE CLOUD FIELD WITHIN THE COLD AIR
ADVECTION REGIME ON THE BACK SIDE OF THE DEPARTING CYCLONE THAT
BROUGHT STORMS TO THE REGION SATURDAY EVENING. H850 TEMPS OFF THE
12Z RAOB FROM BOTH KMPX AND KINL WERE 15C AND 11C
RESPECTIVELY...WHILE AN 18Z PIREP SOUNDINGS FROM KMSP OBSERVED 10C
AT H850. THIS 5C/6HR DROP IN TEMPERATURES IS FURTHER SUPPORTING
EVIDENCE OF THE COLD AIR ADVECTION ONGOING ACROSS THE CWA.

TONIGHT LARGE SCALE SUBSIDENCE AS SEEN IN THE H500 12HR HEIGHT RISES
OF 4DM WILL CAUSE A SURFACE HIGH OF 1016MB TO BUILD OVER THE
REGION...WITH THE RIDGE AXIS ORIENTED ALONG AND JUST EAST OF THE RED
RIVER VALLEY. UNDER CLEAR CONDITIONS THIS WOULD SUPPORT RADIATIONAL
COOLING AND TEMPERATURES FALLING OVERNIGHT...BUT A PIREP FROM FARGO
INDICATED THE STRATUS WAS 1700FT THICK. THE RAP13 KEEPS 75-80RH
WITHIN THE 0-1KM LATER...INDICATING THAT THIS STRATUS DECK MAY
PERSIST LONGER THAN ANTICIPATED. MEMBERS 1 AND 2 OF THE 15Z
HOPWRF...WHICH HAPPEN TO USE THE RAP13 BOUNDARY CONDITIONS...ALSO
PORTRAY THIS LINGERING STRATUS. THEREFORE COULD SEE QUITE A RANGE IN
LOW TEMPERATURE BETWEEN THE FAR NORTHWESTERN PART OF THE CWA THAT IS
MORE LIKELY TO CLEAR OUT...AND THOSE PLACES THAT REMAIN OVERCAST. ON
MONDAY HIGH PRESSURE WILL REMAIN IN CONTROL. BUFR SOUNDINGS INDICATE
LIGHT NORTHERLY WINDS AND PLENTY OF SUNSHINE WITH HIGH TEMPERATURES
IN THE MID 70S.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN SEP 1 2013

THINGS COULDN/T BE MUCH QUIETER WEATHERWISE... WITH DRY
NORTHWESTERLY MID-UPPER LEVEL FLOW IN CONTROL THROUGH MOST OF THE
PERIOD. THE GFS AND ECMWF ARE IN REMARKABLY GOOD AGREEMENT THROUGH
NEXT WEEKEND... AND THE LIMITED SPREAD IN THE ENSEMBLES SUGGESTS
THERE/S GOOD CONFIDENCE IN THE BIG PICTURE. WE/LL REMAIN ON THE
EASTERN PERIPHERY OF THE UPPER RIDGE THROUGH MOST OF THE WEEK...
WITH ONE SHORTWAVE PASSING BY TO OUR NORTHEAST AROUND WEDNESDAY
WHICH COULD HELP GENERATE PCPN OVER THE SOUTHWEST PORTION OF THE
AREA AS IT HELPS TO INCREASE THE BAROCLINITY IN THAT REGION DUE TO
THE BUILDING HEAT/HUMIDITY SOUTHWEST OF THERE. OTHERWISE... THINGS
LOOK PCPN-FREE WITH NEAR TO SLIGHTLY BELOW NORMAL TEMPERATURES AT
THE START OF THE WEEK GIVING WAY TO ABOVE NORMAL TEMPERATURES BY
THE END OF THE WEEK AS THE UPPER RIDGE LOOKS TO RE-ASSERT ITSELF
INTO THE REGION WHILE A DECENT SHORTWAVE WORKS THROUGH THE PACIFIC
NORTHWEST AND NORTHERN ROCKIES IN THE SATURDAY-SUNDAY TIME FRAME.
THERE IS A CHANCE FOR SOME PCPN AREAWIDE BY SUNDAY AS RETURN FLOW
AND WARM ADVECTION TRY TO TAKE ADVANTAGE OF INCREASING INSTABILITY
ACROSS THE AREA. KEPT FORECAST TEMPERATURES BELOW 90 FOR FRIDAY
THROUGH SUNDAY FOR NOW... BUT IT CERTAINLY IS POSSIBLE THAT SOME
90S COULD FIND THEIR WAY BACK INTO THE FORECAST GIVEN PROGGED
850MB TEMPERATURES. BUT... GIVEN UNCERTAINTY ON CLOUD COVER...
PCPN... ETC... DIDN/T GET TOO CARRIED AWAY AT THIS POINT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 645 PM CDT SUN SEP 1 2013

WHILE VERY FEW OF THE MODELS ARE FORECASTING IT TO HAPPEN...DO
THINK THAT STRATUS CLOUDS WILL EXPAND BACK WESTWARD INTO THE AREA
OVERNIGHT AFTER A BRIEF SCATTERING/DEPARTURE OCCURS THIS EVENING. THE
HRRR AND RAP ARE THE MOST INSISTENT ON THE ARRIVAL OF MVFR CIGS AS
FAR WEST AS KAXN-KSTC-KMSP ARRIVING BETWEEN 06Z AND 09Z...THEN
LINGERING UNTIL SHORTLY AFTER DAYBREAK. AFTER THAT...STILL THINK
MOSTLY CLEAR SKIES WILL PREVAIL ON MONDAY...WITH THE EXCEPTION OF
FEW-SCT CU FROM EAST CENTRAL MN INTO WEST CENTRAL WI. WINDS WILL
BE GENERALLY 340-010 IN DIRECTION AT SPEEDS OF 3-8 KTS THROUGH 00Z TUESDAY.

KMSP...
EXPECT THE BKN DECK CIRCA 4500FT TO SCATTER OUT THIS EVE...BUT
THINK LOW CLOUDS /MVFR LEVEL/ WILL SNEAK BACK IN BETWEEN 06Z AND
09Z MONDAY. CONFIDENCE IS NOT HIGH...BUT IT DOES MAKE SENSE GIVEN
THE PATTERN AND THE PREFERRED MODEL SOLUTIONS. CIGS WOULD THEN
IMPROVE TO VFR AROUND 14Z MONDAY...WITH MOSTLY CLEAR SKIES AND A
FEW CU CLOUDS FOR THE REMAINDER OF THE DAY. NORTHWEST WINDS BELOW
10 KTS THROUGH MONDAY...BECOME LIGHT AND VARIABLE AFTER 02Z
TUESDAY.

/OUTLOOK FOR KMSP/
TUE...VFR. WINDS SSW AT 5-10KTS.
WED...VFR. WINDS WSW AT 5-10KTS.
THU...VFR. WINDS LIGHT AND VARIABLE.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&

$$

SHORT TERM...JRB
LONG TERM...TRH
AVIATION...LS







AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 339 AM CDT SAT AUG 31 2013

.DISCUSSION...

THE WEAK CDFNT THAT MOVED THROUGH THE FA ON FRI IS CURRENTLY
STATIONARY OVER NE KS/NRN MO AND WILL WASH OUT THIS MORNING AS THE
LOW-LEVEL FLOW BEGINS TO RESPOND TO THE NEXT MORE POTENT WEATHER
SYSTEM FOR THE FA. THIS SHORTWAVE TROUGH /CURRENTLY OVER SRN SASK
PER EARLY MRNG WV IMAGERY/ WILL TRACK EWD TODAY AND INTO THE
GREAT LAKES TONIGHT. THIS WILL ALLOW FOR A MUCH STRONGER CDFNT TO
MOVE ACROSS THE AREA TONIGHT LEADING TO SIGNIFICANTLY COOLER AIR
FOR THE CWA TO END THE WEEKEND AND START THE NEW WORK WEEK. UNTIL
THEN WE HAVE TO DEAL WITH ONE MORE HOT DAY. THE MODELS ARE
CONSISTENT IN THE HOT H85 TEMPERATURES RECOVERING TODAY...BUT
MIXING WILL BE A TOUCH LOWER THAN ON FRI AND THUS SURFACE
TEMPERATURES ARE EXPECTED TO BE A COUPLE DEGREES COOLER.
NEVERTHELESS WE STILL EXPECT HIGHS IN THE MID 90S CNTRL/SRN AND
AROUND 90 NORTH. THIS ALONG WITH THE DEWPOINTS REMAINING AROUND 70
FOR MOST AREAS WILL LEAD TO HEAT INDEX VALUES OF 95 TO 102 FOR
THIS AFTN...BUT WILL NOT ISSUE AN ADVRY FOR TODAY.

TSRA ARE LIKELY TO DEVELOP THIS AFTN ALONG THE COLD
FRONT...INITIALLY FM NE SD INTO NRN NEB. THESE LOOK TO MAKE IT
INTO THE FA RIGHT AT 00Z IN KNOX/CEDAR COUNTIES AND THUS HAVE
REMOVED POPS FOR THE DAY TIME HOURS. POINT FORECAST SOUNDINGS INDC
AROUND 3000 J/KG OF MLCAPE WILL BE AVAILABLE OVER NE NEB THIS
EVENING ALONG WITH AROUND 30 KT OF EFFECTIVE SHEAR. THIS MAY BE
SUFFICIENT FOR SOME STRONG STORMS TO MAKE IT INTO THE CWA.
RELATIVELY HIGH TEMPERATURE-DEWPOINT SPREADS /LOW SUB-CLOUD RH/
SHOULD KEEP CLOUD BASES HIGH AND BE EFFECTIVE FOR STRONG
DOWNDRAFTS. GIVEN A SCATTERING OF SEMI-ORGANIZED CONVECTION WITH
OUTFLOW...THIS COULD LEAD TO A SMALL FORWARD PROPAGATING MCS THIS
EVENING TRACKING SEWD THROUGH THE FA. SOME OF THE CONVECTION
ALLOWING MODELS INDICATING THIS REACHING I80 BY 03-05Z WHILE
OTHERS INDC LITTLE CONVECTION MAKING IT THAT FAR SOUTH. ALTHOUGH
A SMALL MCS IS POSSIBLE...THE CONFIDENCE IN COVERAGE AND
INTENSITY DECREASES WITH SOUTHWARD EXTEND INTO THE FA DUE
INCREASING CIN...DECREASING CAPE AND SHEAR. WE WILL INCREASE POPS
INTO THE LIKELY CAT OVER THE N THIS EVENING DECREASING TO CHC OVER
THE CNTRL/SRN CWA OVERNIGHT.

THE CDFNT WILL CLEAR THE FA SUN MORNING WITH BREEZY N WINDS
INCREASING...DEWPOINTS DROPPING AND TEMPERATURES MORE SEASONABLE.
THE DRY WX AND SEASONABLE TEMPERATURES ARE EXPECTED TO LAST INTO
TUE BEFORE THE UPPER LEVEL RIDGE BEGINS TO RECOVER INTO THE CNTRL
PLAINS AND TEMPERATURES INCREASE. AS THE MOISTURE RETURNS TO THE
AREA WE MAY SEE AN ISO TSRA ON WED NIGHT BUT MOST OF THIS ACTIVITY
WILL REMAIN OVER THE HIGH PLAINS. TEMPERATURES WILL GET BACK TO
AROUND 90 BY FRI AND WILL LIKELY CONT INTO NEXT WEEKEND.

BOUSTEAD

&&

.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.

CONVECTION HAD MOVED INTO CENTRAL NEBRASKA AND WAS APPROACHING
EASTERN NEBRASKA AT 05Z. HRRR INDICATES SOME POTENTIAL SHOWERS
AT KOFK THROUGH 09Z OTHERWISE PRECIP DISSIPATES BEFORE REACHING
KLNK AND KOMA. MOIST BOUNDARY LAYER AND LIGHT WINDS MAY ALLOW
FOR A PERIOD OF FOG AND MVFR VSBY AT ALL THREE SITES 10Z-14Z.

FOBERT

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.

&&

$$




AREA FORECAST DISCUSSION

NWS HASTINGS NE

 1250 AM CDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 1143 PM CDT FRI AUG 30 2013

CONTINUE TO MONITOR THE AREA OF SHOWERS AND THUNDERSTORMS
SPREADING ACROSS CENTRAL NEBRASKA AT THIS HOUR. WHILE SEVERE
WEATHER IS NOT ANTICIPATED WITH THIS ACTIVITY...LATEST MODEL
GUIDANCE AS WELL AS RADAR TRENDS ARE TRYING TO HOLD THIS AREA OF
SHOWERS AND ISOLATED THUNDERSTORMS TOGETHER AS IT CROSSES THE
FORECAST AREA. AS A RESULT...WENT AHEAD AND INCREASED CHANCES FOR
PRECIPITATION OVERNIGHT TO CLOSELY FOLLOW 02Z HRRR FOR THE NEXT
FEW HOURS...WITH SHOWERS DIMINISHING AROUND 12Z. EVEN SO...EXPECT
LITTLE MORE THAN A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION WITH
THIS ACTIVITY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 430 PM CDT FRI AUG 30 2013

THE MAIN HIGHLIGHTS OF THE NEXT 36 HOURS INCLUDE ONE MORE DAY OF
NOTABLE LATE SUMMER HEAT ON SATURDAY BEFORE READINGS RETURN TO
MORE SEASONAL LEVELS FOR SUNDAY...ALONG WITH STILL HIGHLY-
UNCERTAIN THUNDERSTORM CHANCES BOTH TONIGHT AND ESPECIALLY FOR
SATURDAY NIGHT. WANT TO STATE OFF THE TOP THAT MODELS VARY
CONSIDERABLY ON THE PROBABILITY/COVERAGE OF CONVECTION SATURDAY
NIGHT...AND THUS POPS CONTINUE TO BE CAPPED AT NO MORE THAN 30-40
PERCENT ACROSS THE CWA.

STARTING OFF LATE THIS AFTERNOON...20Z OBJECTIVE SURFACE ANALYSIS
DEPICTS A SURFACE TROUGH/VERY WEAK COLD FRONT STRETCHED FROM
NORTHWEST KS INTO CENTRAL IA...WITH THE VAST MAJORITY OF THE CWA
POSITIONED JUST NORTH OF THIS BOUNDARY. AS A RESULT...BREEZES THIS
AFTERNOON HAVE PREVAILED FROM THE EAST-NORTHEAST AT SPEEDS
GENERALLY AROUND 10 MPH WITH OCCASIONAL HIGHER GUSTS.
HOWEVER...THIS HAS BY NO MEANS BEEN A COOLING NORTHERLY WIND
COMPONENT...AS HIGH TEMPS ARE ON TARGET TO RANGE FROM THE LOW-MID
90S CENTRAL/NORTHEAST...TO THE UPPER 90S TO AROUND 104 IN
SOUTHERN ZONES. FURTHERMORE...THE FAIRLY LIGHT EAST-NORTHEAST
BREEZE HAS ALLOWED DEWPOINTS ACROSS MAINLY THE NORTHEAST 2/3 OF
THE CWA TO REMAIN WELL UP AROUND 70...RESULTING IN POSSIBLY THE
MOST WIDESPREAD COVERAGE OF 100-105 HEAT INDEX VALUES WE HAVE SEEN
ALL WEEK...WITH VALUES IN ALL AREAS LIKELY SAFELY UNDER 100 BY
01Z/8PM. ALOFT...WATER VAPOR IMAGERY SHOWS THE CWA LOCATED
NORTHEAST OF THE CENTER OF THE EXPANSIVE MID/UPPER RIDGE AXIS
CENTERED OVER CO...RESULTING IN NORTH/NORTHWEST FLOW OVERHEAD.
WHILE WATER VAPOR AND MODELED VORTICITY FIELDS HINT AT SOME SUBTLE
PERTURBATIONS HELPING KICK OFF HIGH PLAINS CONVECTION OFF TO OUR
WEST AT THIS HOUR...BY FAR THE MOST NOTABLE SHORTWAVE OF INTEREST
FOR THE NEXT FEW DAYS WEATHER IS SHIFTING EAST INTO SOUTHERN
ALBERTA AT THIS TIME. VISIBLE SATELLITE LATE THIS AFTERNOON SHOWS
ESSENTIALLY CLOUD-FREE SKIES OVER THE VAST MAJORITY OF THE
CWA...WITH ONLY SOME VERY HIGH BASED CUMULUS DEVELOPING FROM
INTENSE HEATING IN OUR FAR SOUTHERN KS ZONES.

TURNING TO THE EVENING/OVERNIGHT HOURS...FROM A BASIC SENSE HAVE
MADE VERY LITTLE CHANGE TO THE PREVIOUS FORECAST. HAVE KEPT LOW
END 20-30 PERCENT STORM CHANCES CONFINED TO ROUGHLY THE NORTHWEST
1/3 OF THE CWA...WITH TWO POSSIBLE SCENARIOS ENVISIONED AND
PORTRAYED BY VARIOUS MODELS. STARTING WITH THE BIG PICTURE
ALOFT...VERY SUBTLE HEIGHT FALLS WILL OCCUR AS THE LARGE RIDGE
AXIS FLATTENS JUST A BIT IN RESPONSE TO THE AFOREMENTIONED CANADIAN
SHORTWAVE TROUGH SHIFTING EAST TO JUST NORTH OF THE MT/ND BORDER
BY SUNRISE. CLOSER TO HOME...VERY SUBTLE MID LEVEL
PERTURBATIONS...POSSIBLY CONVECTIVELY DRIVEN...WILL CONTINUE
SHIFTING EAST TOWARD/INTO THE CWA FROM THE CENTRAL HIGH PLAINS.
SOME MODELS...NAMELY THE HRRR AND 12Z 4KM WRF-NMM...ARE
SURPRISINGLY AGGRESSIVE IN DRIVING HIGH PLAINS CONVECTION EASTWARD
INTO AT LEAST WESTERN PORTIONS OF THE CWA THIS EVENING...BUT WITH
A GENERAL TREND OF KILLING OFF CONVECTION AS IT GETS TOWARD
CENTRAL PORTIONS OF THE CWA LIKELY IN RESPONSE TO INCREASING CINH.
ALTHOUGH A FEW STORMS ARE ALREADY EVIDENT 100+ MILES WEST OF THE
CWA...UNCERTAINTY IS QUITE HIGH WHETHER OR NOT ANY OF THIS WILL
ACTUALLY SLIP INTO OUR AREA...AND THUS OPTED TO KEEP LOW POPS
CONFINED TO WESTERN COUNTIES AND NOT ADVERTISE ANYTHING ACROSS THE
MAJORITY OF THE AREA...BUT THIS WILL NEED WATCHED. LATER IN THE
NIGHT...MODELS SUCH AS THE RAP KICK OFF A POTENTIALLY SEPARATE
AREA OF HIGH-BASED CONVECTION IN OUR NORTHWEST COUNTIES POSSIBLY
IN RESPONSE TO MID-LEVEL THETA-E ADVECTION...BUT AGAIN THIS IS
MAINLY IN THE AREA ALREADY COVERED WITH LOW POPS. IF STORMS
DEVELOP/MOVE IN THIS EVENING/OVERNIGHT...WOULD BE SURPRISED TO SEE
MORE THAN SMALL SUB-SEVERE HAIL. OTHERWISE...BREEZES TONIGHT WILL
AVERAGE VERY LIGHT/EASTERLY...AND MADE LITTLE IF ANY CHANGE TO
OVERNIGHT LOWS WITH MAINLY 66-71.

TURNING TO THE SATURDAY DAYTIME/SATURDAY NIGHT HOURS...AGAIN ON
THE SURFACE THERE HAS BEEN LITTLE NOTICEABLE CHANGE FROM THE
PREVIOUS FORECAST...WITH THE OVERALL BEST CHANCES FOR RAIN/STORMS
DURING THE CURRENT VALID 7-DAY FORECAST ARRIVING SATURDAY
NIGHT...ALTHOUGH BY FAR FROM A SURE THING. ON THE LARGE
SCALE...THE FAIRLY VIGOROUS SHORTWAVE TROUGH ALONG CENTRAL
PORTIONS OF THE U.S./CANADIAN BORDER ON SATURDAY MORNING WILL
SLIDE EAST-SOUTHEAST TO OVER/NEAR LAKE SUPERIOR BY SUNRISE SUNDAY
MORNING...WITH THIS WAVE LOWERING HEIGHTS FURTHER OVER THE LOCAL
AREA AND SHUNTING THE RIDGE SLIGHTLY OFF TO THE SOUTHWEST A BIT.
AT THE SURFACE...BY FAR THE BIG STORY IS A LEGITIMATE COLD FRONT
THAT WILL BE FORCED SOUTHWARD INTO THE CENTRAL PLAINS FROM THIS
WAVE. DURING THE DAYTIME HOURS...THERE IS GOOD AGREEMENT THIS
FRONT WILL BE POSITIONED AT LEAST SLIGHTLY NORTHWEST OF THE CWA
THROUGH LATE AFTERNOON...BEFORE PASSING THROUGH SOMEWHAT
AGGRESSIVELY DURING THE NIGHT AS FAR AS SUMMER COLD FRONTS
GO...WITH ALL AREAS EXPECTED TO HAVE A STEADY 10+ MPH NORTH BREEZE
AND INCREASINGLY COOLER/DRIER AIR BY SUNRISE SUNDAY MORNING. DUE
TO THE CWA REMAINING AHEAD OF THE FRONT DURING THE DAY...ONE MORE
HOT/STEAMY AFTERNOON IS IN STORE...WITH MAYBE ONLY A BIT MORE IN
THE WAY OF MID/HIGH CLOUDS POSSIBLE HOLDING SOME AREAS A TAD
COOLER THAN TODAY...BUT STILL AIMING FOR LOW-MID 90S
CENTRAL/NORTHEAST TO NEAR 100 SOUTH/SOUTHWEST...WITH HEAT INDEX
VALUES AGAIN AROUND 100 OR SLIGHTLY HIGHER. AS FOR DAYTIME
CONVECTIVE CHANCES...THERE IS ADMITTEDLY SOME UNCERTAINTY
HERE...AS SOME MODELS SUCH AS THE NAM SUGGEST THAT ESPECIALLY THE
WESTERN 1/2 OF THE CWA COULD SEE SOME LIKELY HIGH-BASED DAYTIME
CONVECTION...EVEN IN THE MORNING...POSSIBLY A CONTINUATION OF SOME
ACTIVITY THAT MIGHT DEVELOP LATE TONIGHT. HOWEVER...FORECAST
SOUNDINGS AND A CONCEPTUAL MODEL OF THIS PATTERN SUGGEST THAT VERY
WARM MID LEVEL TEMPERATURES ARE MORE LIKELY TO INHIBIT DAYTIME
CONVECTION THAN SUPPORT IT. SO ALTHOUGH ITS NO GUARANTEE...LEFT
POPS BELOW THE MENTIONABLE 15+ PERCENT THRESHOLD IN THE MORNING AND
THROUGH MID-AFTERNOON...BUT LEFT SLIGHT CHANCES MAINLY IN THE
WESTERN 1/2 DURING THE LATE AFTERNOON JUST IN CASE SOMETHING CAN
GET GOING IN THE HOT/DEEPLY MIXED AIRMASS AHEAD OF THE FRONT.

CERTAINLY THE BETTER LARGE-SCALE SUPPORT TO BREAK THROUGH THE CAP
AND SUPPORT CONVECTION COMES SATURDAY NIGHT...AS THE SURFACE COLD
FRONT PASSES THROUGH AND IS ACCOMPANIED/FOLLOWED BY A DECENT AXIS
OF MID LEVEL FRONTOGENESIS. EVEN SO...WITH THE MAIN TRACK OF THE
PARENT SHORTWAVE TROUGH TRACKING HUNDREDS OF MILES NORTHEAST OF
THE CWA...THERE ARE PLENTY OF QUESTIONS ABOUT HOW WIDESPREAD THIS
CONVECTION WILL BE. FOR EXAMPLE...WILL IT SWEEP THROUGH FROM
NORTHWEST-SOUTHEAST IN A FAIRLY SOLID LINE AS THE 12Z NAM WOULD
SUGGEST...OR WILL IT BE VERY HIT-AND-MISS AND IN FACT MISS THE
MAJORITY OF THE AREA ALTOGETHER AS THE 12Z 4KM-WRF NMM
REFLECTIVITY PROG WOULD SUGGEST. WITH THIS STILL BEING 24+ HOURS
OUT...OPTED TO PLAY POPS FAIRLY STATUS QUO FOR NOW...CAPPING THEM
IN THE 30-40 PERCENT RANGE GIVEN THIS DEGREE OF UNCERTAINTY.
IF/WHEN STORM FORM...CERTAINLY CANNOT RULE OUT AT LEAST A MARGINAL
SEVERE THREAT...WITH THE NAM ADVERTISING 2000+ J/KG OF CAPE IN THE
850-700MB LAYER IN THE EVENING...BUT IN THE PRESENCE OF ONLY
25-30KT OF DEEP LAYER SHEAR. ITS CERTAINLY POSSIBLE THAT IF ENOUGH
STORMS FORM AND DEVELOP INTO A FORWARD-PROPAGATING LINE THAT AN
ENHANCED WIND THREAT COULD MATERIALIZE...BUT THIS IS ALL
PREDICATED ON HOW WIDESPREAD DEVELOPMENT ULTIMATELY IS. NO MATTER
WHAT...ROUGHLY THE NORTHWEST 1/3 TO 1/2 OF THE CWA SHOULD BE CLEAR
OF STORM CHANCES BY AROUND MIDNIGHT OR SHORTLY THEREAFTER...WITH
THE LATE NIGHT FOCUS IN THE SOUTHEASTERN 1/2. LOW TEMPS BY SUNRISE
SUNDAY ARE FORECAST TO RANGE LOW 60S NORTH TO NEAR 70 FAR
SOUTHEAST.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 PM CDT FRI AUG 30 2013

MAIN CONCERNS ARE CHANCES FOR THUNDERSTORMS SUNDAY MORNING AND
WEDNESDAY EVENING.

ON THE LARGE SCALE...THE WEATHER PATTERN WILL BE SWINGING TO A
NORTHWEST FLOW REGIME AS THE UPPER LEVEL RIDGE THAT HAS BEEN
PERSISTENT OVER THE AREA THE LAST WEEK OR SO RETROGRADES WEST. THIS
CHANGE IN FLOW WILL RESULT IN TEMPERATURES ABOUT 10 DEGREES COOLER
THAN THIS WEEK AND SOME LOW CHANCES FOR RAIN AS FRONTAL BOUNDARIES
INTERMITTENTLY MOVE THROUGH THE AREA.

MODELS SUGGESTING LINGERING STORMS POSSIBLE EARLY SUNDAY MORNING
BEFORE CONVECTION EXITS SOUTHEAST OF THE AREA. WE LEFT SMALL CHANCES
OF RAIN IN OVER THE EXTREME SOUTHEAST CORNER OF THE CWA SUNDAY
MORNING AS THE FRONT SAGS OUT OF THE AREA. ALL MODELS SUGGEST A
CHANCE FOR STORMS WEDNESDAY EVENING AS ANOTHER COOL FRONT MOVES
THROUGH THE AREA. THERE IS A MARGINAL THREAT THAT A FEW OF THE
STORMS MAY PRODUCE SMALL HAIL AND GUSTY WINDS WEDNESDAY NIGHT
DUE TO LOW TO MARGINAL INSTABILITY AND WEAK SHEAR.

OTHER THAN THOSE TWO PERIODS...HIGH PRESSURE SHOULD BE THE DOMINANT
WEATHER FEATURE. SO DRY AND NEAR TO SLIGHTLY ABOVE NORMAL TEMPS WILL
BE THE RULE MOST DAYS.

&&

.AVIATION...(FOR THE 06Z KGRI TAF THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1245 AM CDT SAT AUG 31 2013

A SMALL LINE OF SHOWERS AND THUNDERSTORMS IS RAPIDLY EXPANDING
TOWARD KGRI THIS MORNING. WHILE VFR CONDITIONS ARE EXPECTED TO
PREVAIL AS THIS LINE MOVES ACROSS THE TERMINAL...MAY SEE A BRIEF
MVFR VSBY OR CIG IN A -SHRA OR -TSRA. EVEN SO...CONFIDENCE OF THIS
WAS LOW ENOUGH TO NOT INCLUDE A TEMPO GROUP IN THE TAF FOR THE
TIME BEING. ONCE THE OVERALL THREAT OF SHRAS DIMINISHES AROUND
09-10Z...SKIES WILL BEGIN TO CLEAR AND LIGHT WINDS WILL PREVAIL
THROUGH THE REMAINDER OF THE OVERNIGHT HOURS BEFORE INCREASING OUT
OF THE SOUTH DURING THE MORNING HOURS SATURDAY. SOUTHERLY WINDS
ARE THEN EXPECTED TO PREVAIL FOR THE DURATION OF THE DAY AHEAD OF
AN APPROACHING COLD FRONT...WHICH WILL BRING GUSTY NORTHWESTERLY
WINDS AND THE CHANCE FOR SHRSA/TSRAS AFT 01/04Z.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...SAR
SHORT TERM...PFANNKUCH
LONG TERM...EDDY
AVIATION...SAR







AREA FORECAST DISCUSSION

NWS NORTH PLATTE NE

 1225 AM CDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 1056 PM CDT FRI AUG 30 2013

SEVERE WEATHER THREAT HAS DIMINISHED AND WILL DROP THE EXTENDED
WATCH EARLY. REMAINDER OF FORECAST ON TRACK.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 307 PM CDT FRI AUG 30 2013

TONIGHT THROUGH SATURDAY...A WEAK UPPER LEVEL DISTURBANCE...
CURRENTLY ACROSS THE WYOMING...WILL MOVE ACROSS THE FCST AREA
TONIGHT SPAWNING A FAIRLY ORGANIZED AREA OF TSTMS. ALL MODELS SHOW
K INDICES INCREASING TO AROUND 40C OR GREATER. THE RAP AND OTHER
MODELS SHOW PRECIPITABLE WATER INCREASING TO 1.50 INCHES OR
GREATER. FCST STORM MOTION OF 10KT OR LESS WOULD SUPPORT LOCALLY
HEAVY RAINFALL AND WEAK WINDS ALOFT 30KT OR LESS AT AND BELOW
300MB SUGGEST OUTFLOW DOMINANT COLD POOL DRIVEN BOW SEGMENTS
CAPABLE OF GUSTY WINDS.

LOW LEVEL EASTERLIES AND WEAK WESTERLIES ALOFT PRODUCE BULK SHEAR OF
35 TO 40 KT SO SOME STORMS THIS EVENING COULD BECOME SEVERE WITH
WIND DAMAGE AND LARGE HAIL. SPC PROVIDED THIS DISCUSSION AT 227 PM
CDT...RECENT LIGHTNING WITHIN THE CONVECTION ALONG THE BLACK
HILLS AND LARAMIE MOUNTAINS HAS INCREASED CONFIDENCE THAT THE
ENVIRONMENT ACROSS THE CNTRL PLAINS IS GRADUALLY BECOMING MORE
SUPPORTIVE OF SURFACE-BASED CONVECTIVE INITIATION. 12Z RAP SOUNDING
MODIFIED FOR 19Z SURFACE OBSERVATION -- 93/62 -- YIELDS STRONG
SURFACE-BASED INSTABILITY /SBCAPE OVER 3000 J PER KG/ AND LITTLE
REMAINING CINH. INCREASED CONVERGENCE ALONG A WEAK SURFACE TROUGH
AND CONTINUED DESTABILIZATION FOSTERED BY ISOLATION IS EXPECTED TO
RESULT IN ADDITIONAL SURFACE-BASED CONVECTIVE DEVELOPMENT DURING THE
NEXT HOUR OR TWO.

THE STORM COMPLEX COULD MOVE MOSTLY EAST ACCORDING TO THE RAP MODEL
OR TAKE A SOUTHEAST TURN AS INDICATED BY THE HRRR. EITHER WAY THE
CONVECTION WILL AFFECT MOST OF THE FCST AREA AND EXIT SOUTH OR EAST
BY AROUND 12Z.

THIS TSTM COMPLEX SHOULD SET UP A FRONTAL BOUNDARY FOR ADDITIONAL
STORM DEVELOPMENT SATURDAY AFTN AND BEYOND WITH THE BEST SHEAR AND
INSTABILITY ACROSS NCNTL NEB NEAR KANW AND KONL. THE MODELS HAVE A
TOTALLY DIFFERENT IDEA IN MIND WITH THE FRONT AND LIFT IT RAPIDLY
NORTH BY 15Z SATURDAY MORNING AND THEN DROP ANOTHER COLD FRONT
THROUGH DURING THE AFTN. SO THERE IS A DISCONNECT IN CONVENTIONAL
STORM THEORY VS THE MODELS. IF THE FRONT IS DOES NOT RETREAT NORTH
AS QUICKLY THAN STORM DEVELOPMENT COULD BE MUCH FARTHER
SOUTH...PERHAPS OVER KS. THE FCST USES A BLEND OF NAM...GEMREG...GFS
AND ECM FOR A 30 POP FROM 20Z ONWARD...MAINLY SOUTH AND EAST OF
KVTN/KIML.

TEMPERATURES ARE A BLEND OF TRIED AND TRUE MODEL DATA PLUS BIAS
CORRECTION FOR HIGHS IN THE LOWER 90S NORTH TO UPPER 90S SOUTH.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 307 PM CDT FRI AUG 30 2013

SATURDAY NIGHT THROUGH LABOR DAY...

COLD FRONT SHOULD STRETCH FROM NEAR ANW THROUGH LBF AND IML EARLY
SATURDAY EVENING. DO EXPECT SCATTERED SHOWERS AND THUNDERSTORMS
ALONG AND AHEAD OF THE FRONT. COVERAGE MAY END UP LESS ACROSS SWRN
NEBR WHICH WILL BE FURTHER REMOVED FROM COOLER TEMPERATURES ALOFT
ASSOCIATED WITH MAIN UPPER TROUGH ACROSS MINNESOTA. ONLY A SLIGHT
CHANCE FOR THUNDERSTORMS FAR SOUTHEAST AFTER MIDNIGHT.  DRY AND
LESS HOT SUNDAY AND LABOR DAY. HIGHS SUNDAY FORECAST VERY NEAR
PREVIOUS FROM NEAR 83 NCTRL AND 85 TO 88 SOUTHWEST. NORTHERLY WINDS
SUNDAY LOOK FAIRLY LIGHT FROM 5 TO 15 MPH WEST AND 10 TO 20 MPH
EAST. ON LABOR DAY...NORTHWEST FLOW ALOFT WILL CONTINUE WITH A
RETURN SOUTHEAST FLOW AT THE SURFACE AND HIGHS FROM NEAR 83
NORTHEAST TO NEAR 90 WEST TIER. SOUTHERLY WINDS MONDAY FROM 10 TO
20 MPH WEST TO 5 TO 15 MPH EAST.

ON TUESDAY THROUGH FRIDAY...

A HEAT UP AGAIN LIKELY AS UPPER RIDGE PERSISTS OVER COLORADO AND
TROUGHING INCREASES ACROSS THE PAC NW AND NORTHEASTERN U.S. A WEAK
COLD FRONT AND DISTURBANCE IN NORTHWEST FLOW ALOFT INDICATED BY
THE GFS AND ECMWF. THIS FRONT ASSOCIATED WITH A DEEP UPPER LOW
MOVING ACROSS HUDSON BAY. AS A RESULT OF ECMWF CONSISTENCY AND
FAIR AGREEMENT BY THE GFS...WILL INTRODUCE A SLIGHT CHANCE FOR
THUNDERSTORMS WEDNESDAY NIGHT. AN OTHERWISE DRY EXTENDED. HIGHS
FORECAST IN THE UPPER 80S TO LOW 90S MOST AREAS WITH MID 90S PARTS
OF SWRN NEBR.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1224 AM CDT SAT AUG 31 2013

THUNDERSTORMS WILL CONTINUE OVER WESTERN AND CENTRAL NEBRASKA
TONIGHT. SOME MVFR CEILINGS IN THE VICINITY OF THUNDERSTORMS WITH
GUSTY WINDS TO 35 KTS. HAVE INCLUDED THUNDERSTORMS IN THE TAF AT
KLBF WITH STORMS TO THE WEST BUT HAVE LEFT OUT OF KVTN. SOME PATCHY
FOG IS POSSIBLE OVER NORTHERN NEBRASKA AROUND SUNRISE. THUNDERSTORMS
ARE EXPECTED OVER SOUTHWEST NEBRASKA AGAIN SATURDAY AFTERNOON ALONG
THE COLD FRONT.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...POWER
SHORT TERM...CDC
LONG TERM...ROBERG
AVIATION...POWER







AREA FORECAST DISCUSSION

NWS HASTINGS NE

 1150 PM CDT FRI AUG 30 2013

.UPDATE...
ISSUED AT 1143 PM CDT FRI AUG 30 2013

CONTINUE TO MONITOR THE AREA OF SHOWERS AND THUNDERSTORMS
SPREADING ACROSS CENTRAL NEBRASKA AT THIS HOUR. WHILE SEVERE
WEATHER IS NOT ANTICIPATED WITH THIS ACTIVITY...LATEST MODEL
GUIDANCE AS WELL AS RADAR TRENDS ARE TRYING TO HOLD THIS AREA OF
SHOWERS AND ISOLATED THUNDERSTORMS TOGETHER AS IT CROSSES THE
FORECAST AREA. AS A RESULT...WENT AHEAD AND INCREASED CHANCES FOR
PRECIPITATION OVERNIGHT TO CLOSELY FOLLOW 02Z HRRR FOR THE NEXT
FEW HOURS...WITH SHOWERS DIMINISHING AROUND 12Z. EVEN SO...EXPECT
LITTLE MORE THAN A FEW HUNDREDTHS OF AN INCH OF PRECIPITATION WITH
THIS ACTIVITY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 430 PM CDT FRI AUG 30 2013

THE MAIN HIGHLIGHTS OF THE NEXT 36 HOURS INCLUDE ONE MORE DAY OF
NOTABLE LATE SUMMER HEAT ON SATURDAY BEFORE READINGS RETURN TO
MORE SEASONAL LEVELS FOR SUNDAY...ALONG WITH STILL HIGHLY-
UNCERTAIN THUNDERSTORM CHANCES BOTH TONIGHT AND ESPECIALLY FOR
SATURDAY NIGHT. WANT TO STATE OFF THE TOP THAT MODELS VARY
CONSIDERABLY ON THE PROBABILITY/COVERAGE OF CONVECTION SATURDAY
NIGHT...AND THUS POPS CONTINUE TO BE CAPPED AT NO MORE THAN 30-40
PERCENT ACROSS THE CWA.

STARTING OFF LATE THIS AFTERNOON...20Z OBJECTIVE SURFACE ANALYSIS
DEPICTS A SURFACE TROUGH/VERY WEAK COLD FRONT STRETCHED FROM
NORTHWEST KS INTO CENTRAL IA...WITH THE VAST MAJORITY OF THE CWA
POSITIONED JUST NORTH OF THIS BOUNDARY. AS A RESULT...BREEZES THIS
AFTERNOON HAVE PREVAILED FROM THE EAST-NORTHEAST AT SPEEDS
GENERALLY AROUND 10 MPH WITH OCCASIONAL HIGHER GUSTS.
HOWEVER...THIS HAS BY NO MEANS BEEN A COOLING NORTHERLY WIND
COMPONENT...AS HIGH TEMPS ARE ON TARGET TO RANGE FROM THE LOW-MID
90S CENTRAL/NORTHEAST...TO THE UPPER 90S TO AROUND 104 IN
SOUTHERN ZONES. FURTHERMORE...THE FAIRLY LIGHT EAST-NORTHEAST
BREEZE HAS ALLOWED DEWPOINTS ACROSS MAINLY THE NORTHEAST 2/3 OF
THE CWA TO REMAIN WELL UP AROUND 70...RESULTING IN POSSIBLY THE
MOST WIDESPREAD COVERAGE OF 100-105 HEAT INDEX VALUES WE HAVE SEEN
ALL WEEK...WITH VALUES IN ALL AREAS LIKELY SAFELY UNDER 100 BY
01Z/8PM. ALOFT...WATER VAPOR IMAGERY SHOWS THE CWA LOCATED
NORTHEAST OF THE CENTER OF THE EXPANSIVE MID/UPPER RIDGE AXIS
CENTERED OVER CO...RESULTING IN NORTH/NORTHWEST FLOW OVERHEAD.
WHILE WATER VAPOR AND MODELED VORTICITY FIELDS HINT AT SOME SUBTLE
PERTURBATIONS HELPING KICK OFF HIGH PLAINS CONVECTION OFF TO OUR
WEST AT THIS HOUR...BY FAR THE MOST NOTABLE SHORTWAVE OF INTEREST
FOR THE NEXT FEW DAYS WEATHER IS SHIFTING EAST INTO SOUTHERN
ALBERTA AT THIS TIME. VISIBLE SATELLITE LATE THIS AFTERNOON SHOWS
ESSENTIALLY CLOUD-FREE SKIES OVER THE VAST MAJORITY OF THE
CWA...WITH ONLY SOME VERY HIGH BASED CUMULUS DEVELOPING FROM
INTENSE HEATING IN OUR FAR SOUTHERN KS ZONES.

TURNING TO THE EVENING/OVERNIGHT HOURS...FROM A BASIC SENSE HAVE
MADE VERY LITTLE CHANGE TO THE PREVIOUS FORECAST. HAVE KEPT LOW
END 20-30 PERCENT STORM CHANCES CONFINED TO ROUGHLY THE NORTHWEST
1/3 OF THE CWA...WITH TWO POSSIBLE SCENARIOS ENVISIONED AND
PORTRAYED BY VARIOUS MODELS. STARTING WITH THE BIG PICTURE
ALOFT...VERY SUBTLE HEIGHT FALLS WILL OCCUR AS THE LARGE RIDGE
AXIS FLATTENS JUST A BIT IN RESPONSE TO THE AFOREMENTIONED CANADIAN
SHORTWAVE TROUGH SHIFTING EAST TO JUST NORTH OF THE MT/ND BORDER
BY SUNRISE. CLOSER TO HOME...VERY SUBTLE MID LEVEL
PERTURBATIONS...POSSIBLY CONVECTIVELY DRIVEN...WILL CONTINUE
SHIFTING EAST TOWARD/INTO THE CWA FROM THE CENTRAL HIGH PLAINS.
SOME MODELS...NAMELY THE HRRR AND 12Z 4KM WRF-NMM...ARE
SURPRISINGLY AGGRESSIVE IN DRIVING HIGH PLAINS CONVECTION EASTWARD
INTO AT LEAST WESTERN PORTIONS OF THE CWA THIS EVENING...BUT WITH
A GENERAL TREND OF KILLING OFF CONVECTION AS IT GETS TOWARD
CENTRAL PORTIONS OF THE CWA LIKELY IN RESPONSE TO INCREASING CINH.
ALTHOUGH A FEW STORMS ARE ALREADY EVIDENT 100+ MILES WEST OF THE
CWA...UNCERTAINTY IS QUITE HIGH WHETHER OR NOT ANY OF THIS WILL
ACTUALLY SLIP INTO OUR AREA...AND THUS OPTED TO KEEP LOW POPS
CONFINED TO WESTERN COUNTIES AND NOT ADVERTISE ANYTHING ACROSS THE
MAJORITY OF THE AREA...BUT THIS WILL NEED WATCHED. LATER IN THE
NIGHT...MODELS SUCH AS THE RAP KICK OFF A POTENTIALLY SEPARATE
AREA OF HIGH-BASED CONVECTION IN OUR NORTHWEST COUNTIES POSSIBLY
IN RESPONSE TO MID-LEVEL THETA-E ADVECTION...BUT AGAIN THIS IS
MAINLY IN THE AREA ALREADY COVERED WITH LOW POPS. IF STORMS
DEVELOP/MOVE IN THIS EVENING/OVERNIGHT...WOULD BE SURPRISED TO SEE
MORE THAN SMALL SUB-SEVERE HAIL. OTHERWISE...BREEZES TONIGHT WILL
AVERAGE VERY LIGHT/EASTERLY...AND MADE LITTLE IF ANY CHANGE TO
OVERNIGHT LOWS WITH MAINLY 66-71.

TURNING TO THE SATURDAY DAYTIME/SATURDAY NIGHT HOURS...AGAIN ON
THE SURFACE THERE HAS BEEN LITTLE NOTICEABLE CHANGE FROM THE
PREVIOUS FORECAST...WITH THE OVERALL BEST CHANCES FOR RAIN/STORMS
DURING THE CURRENT VALID 7-DAY FORECAST ARRIVING SATURDAY
NIGHT...ALTHOUGH BY FAR FROM A SURE THING. ON THE LARGE
SCALE...THE FAIRLY VIGOROUS SHORTWAVE TROUGH ALONG CENTRAL
PORTIONS OF THE U.S./CANADIAN BORDER ON SATURDAY MORNING WILL
SLIDE EAST-SOUTHEAST TO OVER/NEAR LAKE SUPERIOR BY SUNRISE SUNDAY
MORNING...WITH THIS WAVE LOWERING HEIGHTS FURTHER OVER THE LOCAL
AREA AND SHUNTING THE RIDGE SLIGHTLY OFF TO THE SOUTHWEST A BIT.
AT THE SURFACE...BY FAR THE BIG STORY IS A LEGITIMATE COLD FRONT
THAT WILL BE FORCED SOUTHWARD INTO THE CENTRAL PLAINS FROM THIS
WAVE. DURING THE DAYTIME HOURS...THERE IS GOOD AGREEMENT THIS
FRONT WILL BE POSITIONED AT LEAST SLIGHTLY NORTHWEST OF THE CWA
THROUGH LATE AFTERNOON...BEFORE PASSING THROUGH SOMEWHAT
AGGRESSIVELY DURING THE NIGHT AS FAR AS SUMMER COLD FRONTS
GO...WITH ALL AREAS EXPECTED TO HAVE A STEADY 10+ MPH NORTH BREEZE
AND INCREASINGLY COOLER/DRIER AIR BY SUNRISE SUNDAY MORNING. DUE
TO THE CWA REMAINING AHEAD OF THE FRONT DURING THE DAY...ONE MORE
HOT/STEAMY AFTERNOON IS IN STORE...WITH MAYBE ONLY A BIT MORE IN
THE WAY OF MID/HIGH CLOUDS POSSIBLE HOLDING SOME AREAS A TAD
COOLER THAN TODAY...BUT STILL AIMING FOR LOW-MID 90S
CENTRAL/NORTHEAST TO NEAR 100 SOUTH/SOUTHWEST...WITH HEAT INDEX
VALUES AGAIN AROUND 100 OR SLIGHTLY HIGHER. AS FOR DAYTIME
CONVECTIVE CHANCES...THERE IS ADMITTEDLY SOME UNCERTAINTY
HERE...AS SOME MODELS SUCH AS THE NAM SUGGEST THAT ESPECIALLY THE
WESTERN 1/2 OF THE CWA COULD SEE SOME LIKELY HIGH-BASED DAYTIME
CONVECTION...EVEN IN THE MORNING...POSSIBLY A CONTINUATION OF SOME
ACTIVITY THAT MIGHT DEVELOP LATE TONIGHT. HOWEVER...FORECAST
SOUNDINGS AND A CONCEPTUAL MODEL OF THIS PATTERN SUGGEST THAT VERY
WARM MID LEVEL TEMPERATURES ARE MORE LIKELY TO INHIBIT DAYTIME
CONVECTION THAN SUPPORT IT. SO ALTHOUGH ITS NO GUARANTEE...LEFT
POPS BELOW THE MENTIONABLE 15+ PERCENT THRESHOLD IN THE MORNING AND
THROUGH MID-AFTERNOON...BUT LEFT SLIGHT CHANCES MAINLY IN THE
WESTERN 1/2 DURING THE LATE AFTERNOON JUST IN CASE SOMETHING CAN
GET GOING IN THE HOT/DEEPLY MIXED AIRMASS AHEAD OF THE FRONT.

CERTAINLY THE BETTER LARGE-SCALE SUPPORT TO BREAK THROUGH THE CAP
AND SUPPORT CONVECTION COMES SATURDAY NIGHT...AS THE SURFACE COLD
FRONT PASSES THROUGH AND IS ACCOMPANIED/FOLLOWED BY A DECENT AXIS
OF MID LEVEL FRONTOGENESIS. EVEN SO...WITH THE MAIN TRACK OF THE
PARENT SHORTWAVE TROUGH TRACKING HUNDREDS OF MILES NORTHEAST OF
THE CWA...THERE ARE PLENTY OF QUESTIONS ABOUT HOW WIDESPREAD THIS
CONVECTION WILL BE. FOR EXAMPLE...WILL IT SWEEP THROUGH FROM
NORTHWEST-SOUTHEAST IN A FAIRLY SOLID LINE AS THE 12Z NAM WOULD
SUGGEST...OR WILL IT BE VERY HIT-AND-MISS AND IN FACT MISS THE
MAJORITY OF THE AREA ALTOGETHER AS THE 12Z 4KM-WRF NMM
REFLECTIVITY PROG WOULD SUGGEST. WITH THIS STILL BEING 24+ HOURS
OUT...OPTED TO PLAY POPS FAIRLY STATUS QUO FOR NOW...CAPPING THEM
IN THE 30-40 PERCENT RANGE GIVEN THIS DEGREE OF UNCERTAINTY.
IF/WHEN STORM FORM...CERTAINLY CANNOT RULE OUT AT LEAST A MARGINAL
SEVERE THREAT...WITH THE NAM ADVERTISING 2000+ J/KG OF CAPE IN THE
850-700MB LAYER IN THE EVENING...BUT IN THE PRESENCE OF ONLY
25-30KT OF DEEP LAYER SHEAR. ITS CERTAINLY POSSIBLE THAT IF ENOUGH
STORMS FORM AND DEVELOP INTO A FORWARD-PROPAGATING LINE THAT AN
ENHANCED WIND THREAT COULD MATERIALIZE...BUT THIS IS ALL
PREDICATED ON HOW WIDESPREAD DEVELOPMENT ULTIMATELY IS. NO MATTER
WHAT...ROUGHLY THE NORTHWEST 1/3 TO 1/2 OF THE CWA SHOULD BE CLEAR
OF STORM CHANCES BY AROUND MIDNIGHT OR SHORTLY THEREAFTER...WITH
THE LATE NIGHT FOCUS IN THE SOUTHEASTERN 1/2. LOW TEMPS BY SUNRISE
SUNDAY ARE FORECAST TO RANGE LOW 60S NORTH TO NEAR 70 FAR
SOUTHEAST.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 430 PM CDT FRI AUG 30 2013

MAIN CONCERNS ARE CHANCES FOR THUNDERSTORMS SUNDAY MORNING AND
WEDNESDAY EVENING.

ON THE LARGE SCALE...THE WEATHER PATTERN WILL BE SWINGING TO A
NORTHWEST FLOW REGIME AS THE UPPER LEVEL RIDGE THAT HAS BEEN
PERSISTENT OVER THE AREA THE LAST WEEK OR SO RETROGRADES WEST. THIS
CHANGE IN FLOW WILL RESULT IN TEMPERATURES ABOUT 10 DEGREES COOLER
THAN THIS WEEK AND SOME LOW CHANCES FOR RAIN AS FRONTAL BOUNDARIES
INTERMITTENTLY MOVE THROUGH THE AREA.

MODELS SUGGESTING LINGERING STORMS POSSIBLE EARLY SUNDAY MORNING
BEFORE CONVECTION EXITS SOUTHEAST OF THE AREA. WE LEFT SMALL CHANCES
OF RAIN IN OVER THE EXTREME SOUTHEAST CORNER OF THE CWA SUNDAY
MORNING AS THE FRONT SAGS OUT OF THE AREA. ALL MODELS SUGGEST A
CHANCE FOR STORMS WEDNESDAY EVENING AS ANOTHER COOL FRONT MOVES
THROUGH THE AREA. THERE IS A MARGINAL THREAT THAT A FEW OF THE
STORMS MAY PRODUCE SMALL HAIL AND GUSTY WINDS WEDNESDAY NIGHT
DUE TO LOW TO MARGINAL INSTABILITY AND WEAK SHEAR.

OTHER THAN THOSE TWO PERIODS...HIGH PRESSURE SHOULD BE THE DOMINANT
WEATHER FEATURE. SO DRY AND NEAR TO SLIGHTLY ABOVE NORMAL TEMPS WILL
BE THE RULE MOST DAYS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 610 PM CDT FRI AUG 30 2013

VFR CONDITIONS FORECAST THROUGH THE NEXT 24 HOURS.

OCCASIONAL CLOUDS...WITH BASES BETWEEN 7000 AND 15000FT AGL...ARE
EXPECTED THROUGH THE NEXT 24 HOURS. THE SURFACE WIND IS EXPECTED
TO REMAIN LIGHT AND VARIABLE THROUGH EARLY SATURDAY AFTERNOON
BEFORE BECOMING MORE ESTABLISHED FROM THE SOUTH AT AROUND 08KTS.
VISIBILITY RESTRICTION IS NOT EXPECTED AT GRI THROUGH THE NEXT 24
HOURS.

AS OF 23Z...SHOWER AND THUNDERSTORM ACTIVITY CONTINUES ACROSS
WESTERN NEBRASKA. THE PROBABILITY OF THIS ACTIVITY IMPACTING GRI
THIS EVENING OR TONIGHT IS VERY LOW...TOO LOW IN FACT TO INTRODUCE
INTO THE TAF AT THIS TIME. THAT BEING SAID...TRENDS WILL NEED TO
BE MONITORED THROUGH THE NEXT 6-12 HOURS FOR THE POSSIBLE
INSERTION OF CONVECTIVE ACTIVITY INTO THE TAF.


&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

UPDATE...SAR
SHORT TERM...PFANNKUCH
LONG TERM...EDDY
AVIATION...BRYANT







AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 1134 PM CDT FRI AUG 30 2013

.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.

CONVECTION HAD MOVED INTO CENTRAL NEBRASKA AND WAS APPROACHING
EASTERN NEBRASKA AT 05Z. HRRR INDICATES SOME POTENTIAL SHOWERS
AT KOFK THROUGH 09Z OTHERWISE PRECIP DISSIPATES BEFORE REACHING
KLNK AND KOMA. MOIST BOUNDARY LAYER AND LIGHT WINDS MAY ALLOW
FOR A PERIOD OF FOG AND MVFR VSBY AT ALL THREE SITES 10Z-14Z.

&&

.PREV DISCUSSION... /ISSUED 313 PM CDT FRI AUG 30 2013/

DISCUSSION...
LOOKS LIKE WE WILL HAVE ONE MORE DAY OF HEAT BEFORE A BRIEF
COOLDOWN INTO EARLY NEXT WEEK...AND A CHANCE FOR STORMS SATURDAY
NIGHT. THEN PATTERN REBOUNDS BACK TOWARD WARMER THAN NORMAL FOR THE
REST OF NEXT WEEK.

A WEAK COLD FRONT WAS LIMPING THROUGH THE CWA THIS AFTERNOON...WITH
THE ONLY REAL INDICATION OF THE BOUNDARY BEING WINDS SHIFTING FROM
SOUTHWEST TO NORTH. TEMPERATURES WERE STILL CLIMBING WELL INTO THE
90S...AND DEW POINTS STILL IN THE 60S OR LOWER 70S. INSTABILITY WAS
INCREASING TO NEAR 3000 J/KG OF MOST UNSTABLE CAPE...BUT WARM
TEMPERATURES ALOFT WERE KEEPING A LID ON CONVECTION. SHORT RANGE
MESOSCALE MODELS WERE HINTING AT ISOLATED CONVECTION POPPING UP THIS
AFTERNOON IN SOUTHEAST NEBRASKA OR SOUTHWEST IOWA AS FRONT MOVES
THROUGH...BUT LID WILL BE AWFULLY HARD TO OVERCOME. WILL WATCH
TRENDS AND MAY HAVE TO INSERT A SMALL POP IN OUR FAR SOUTHEAST IN
THE EARLY EVENING.

OTHERWISE THIS FRONT WILL WASHOUT OVERNIGHT AND SATURDAY AS WINDS
TURN BACK TO SOUTHERLY WITH THE APPROACH OF ANOTHER COLD FRONT. THAT
FRONT WILL BE DRIVEN BY A STRONG SHORTWAVE RIDING EAST TO SOUTHEAST
THROUGH THE SOUTHERN CANADIAN PLAINS SATURDAY AND INTO THE NORTHERN
GREAT LAKES ON SUNDAY. AHEAD OF THIS FRONT...MOST UNSTABLE CAPE WILL
AGAIN INCREASE TO OVER 2500 J/KG AS SURFACE DEWPOINTS REMAIN BETWEEN
65 AND 70. MID LEVEL TEMPERATURES AT 700MB WILL BE A COUPLE OF
DEGREES COOLER AS WELL. TIMING OF SURFACE CONVERGENCE LOOKS TO ENTER
THE CWA LATE IN THE DAY OVER NORTHEAST NEBRASKA...THEN MOVE STEADILY
THROUGH THE REST OF THE AREA OVERNIGHT. GIVEN DEGREE OF
INSTABILITY...COOLER MID LEVEL TEMPS AND STRONGER CONVERGENCE ALONG
FRONT...EXPECT AT LEAST SCATTERED STORMS TO FIRE ACROSS MUCH OF THE
CWA AS THE FRONT MOVES THROUGH...AND PERHAPS AS EARLY AS LATE
AFTERNOON IN THE NORTHEAST. SEVERE POTENTIAL LOOKS TO BE LOW AS
SHEAR PROFILES WILL BE MODERATE AT BEST AND MOST ACTIVITY WILL BE
OCCURRING DURING TIME OF DECLINING INSTABILITY WITH LOSS OF DAYTIME
HEATING. A FEW STORMS MAY LINGER IN OUR SOUTHEAST INTO SUNDAY
MORNING...BUT THE BEST SHOT OF CONVECTION WILL END BEFORE SUNRISE
FOR MOST OF OUR AREA.

DERGAN

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

$$

FOBERT




AREA FORECAST DISCUSSION...UPDATED

NWS ALBUQUERQUE NM

 1121 PM MDT FRI AUG 30 2013

.AVIATION...
06Z TAF CYCLE
JUST A FEW SHRA/TSRA REMAIN BETWEEN KFMN AND KE33...AND MUCH OF
THIS ACTIVITY SHOULD DIMINISH BY 07Z. HAVE KEPT A PERIOD OF IFR
CIGS IN KGUP OVERNIGHT. OTHERWISE...VFR WILL BE THE RULE THROUGH
AT LEAST 18Z SAT. SHRA/TSRA WILL REDEVELOP SAT AFTN OVER THE HIGH
TERRAIN. THE NRN MTS WILL BE FAVORED...THOUGH SOME OF THIS
ACTIVITY MAY ROLL OFF INTO THE NE PLAINS. LOCALLY HEAVY RAIN WILL
BE THE MAIN THREAT WITH THESE STORMS. MUCH OF THE ACTIVITY WILL
AGAIN DIMINISH BY 06Z SUN.

34

&&

.PREV DISCUSSION...947 PM MDT FRI AUG 30 2013...
WILL ADJUST POPS DOWN CONSIDERABLY FOR THE REMAINDER OF THE NIGHT
BASED ON RADAR TRENDS AND HRRR MODEL. ZONES OUT SHORTLY. CHJ

.PREV DISCUSSION...334 PM MDT FRI AUG 30 2013...
LATEST BLENDED TOTAL PRECIPITABLE WATER SATELLITE IMAGERY
INDICATING A ROUGHLY THREE TENTHS OF AN INCH DROP IN SAME OVER
PAST ROUGHLY 18 HOURS ACROSS NE NM. THUS SOME OF THE SIGNIFICANTLY
DRIER AIR IN E CO EARLIER IS EASING SOUTHWARD INTO THE STATE.
THE RATON DEWPOINT HAS DROPPED TO 29 DEGREES AS OF MID AFTN AND
THIS DRIER AIR EXPECTED TO CONTINUE HEADING TO S AND TO SOME
DEGREE SW OVER NEXT 24 TO 36 HOURS.

CENTER OF THE UPPER HIGH NOW OVER FAR NE NM TODAY WILL SAG A BIT
FARTHER TO SW INTO OR VERY NEAR CENTRAL NM BY SAT AFTN. A SLIGHT
MOISTURE UPTICK MAY STILL OCCUR IN THE NW CORNER OF NM SAT...BUT
ELSEWHERE THE AIRMASS WILL SHOW LITTLE PWAT CHANGE AND IN MANY
CASES SOME DECREASE. LOWERED POPS A BIT MORE ACROSS MAINLY CENTRAL
AND NE NM FOR SAT GIVEN PWAT TREND OF TODAY SO FAR. EXPECT ANOTHER
VERY WARM TO HOT DAY IN EAST NM AGAIN SAT WITH UPPER 90S AND A FEW
TRIPLE DIGIT READINGS AGAIN. DECIDED TO GO AHEAD AT INCLUDE NEAR
RECORD TEMP HIGHLIGHTS IN HAZARD GRID FOR MUCH OF E CENTRAL AND NE
NM SAT.

HIGH PRESSURE WILL STAY OVER CENTRAL NM ON SUN...BUT HAVING LOST A
BIT OF STRENGTH. BACK DOOR COLD FRONT...FIRST IN QUITE SOME TIME...
TO DROP INTO NORTHEASTERN NM SUN MORN...SO SAY MAJORITY OF FCST
MODELS. IN ITS WAKE WILL COME HIGHER SFC DEWPOINTS AND SOME
UPSLOPE FORCING FOR A HEALTHY INCREASE IN SHOWER AND STORM ACTION
ALONG THE EAST SLOPES OF THE SANGRE DE CRISTOS AND INTO THE
NORTHEASTERN PLAINS. HAVE KEPT THE LIKELY POPS CATEGORY IN MUCH OF
THIS REGION...BUT TRIMMED ITS SOUTHERNMOST EXTENT JUST A HAIR.
WEAK STEERING FLOW WILL KEEP OVERALL MOVEMENT OF CELLS VERY SLOW...
BUT THAT MAY CAUSE ACTUAL OVERALL MOVEMENT TO BE MORE DRIVEN BY
FRONTAL MOVEMENT AND BOUNDARY INTERACTIONS.

THE FRONT WILL SURGE FARTHER SOUTH AND WEST SUN LATE AFTN AND
NIGHT...MOST LIKELY MAKING IT TO OR PERHAPS EVEN WEST OF THE
CONTINENTAL DIVIDE BY EARLY MON. SOME LEFTOVER UPSLOPE FLOW MAY
KEEP THINGS GOING ALONG THE CENTRAL MOUNTAIN CHAIN MONDAY...BUT
THE FOCUS MAY SHIFT TOWARD THE DIVIDE AND HIGH TERRAIN WEST OF THE
RIO GRANDE. SOME MODELS ARE LESSENING THEIR EARLIER FAVORING
THEIR MORE WESTWARD BIAS OF THE MON PCPN.

THERE IS STILL NO SIGNS OF THE UPPER HIGH BREAKING DOWN
SIGNIFICANTLY IN MID TO LATER PERIODS...THOUGH THE CENTER MAY EASE
A LITTLE WAYS OUT OF NM. GFS FAVORS AN EVEN STRONGER BACK DOOR
FRONT COMING INTO NM THE WEEKEND OF SEP 7TH...WHILE THE EUROPEAN
IS MUCH SLOWER AND WEAKER WITH IT...SHOWING IT STAYING NE OF THE
STATE THROUGH SUN NIGHT. 43

.FIRE WEATHER...
A DRIER AND MORE STABLE AIRMASS ALOFT HAS PUSHED OVER MORE OF THE
FORECAST AREA TODAY. SHOWERS AND THUNDERSTORMS ARE MUCH MORE MUTED
AS A RESULT. THE MAIN WETTING RAIN CHANCE WILL BE FOUND ALONG
AND WEST OF THE CONTINENTAL DIVIDE. TEMPERATURES ARE QUITE WARM
ACROSS THE EAST WITH NEAR RECORD LEVELS. HUMIDITY VALUES AS A RESULT
HAVE FALLEN INTO THE LOW/MID TEENS ACROSS THE NORTHEAST.

MODELS REMAIN CONSISTENT WITH THE DRIER AND MORE STABLE AIRMASS TO
REMAIN OVER MOST OF THE FORECAST AREA ON SATURDAY AS THE UPPER HIGH
CENTERS ITSELF OVER SOUTHERN NM. THE BEST WETTING RAIN POTENTIAL
WILL BE FOUND ACROSS THE NORTHWEST THIRD OR SO. THE MAIN MONSOONAL
PLUME WILL REMAIN OVER ARIZONA. NEAR RECORD HIGH TEMPERATURES ONCE
AGAIN POSSIBLE ACROSS THE NORTHEAST WITH ABOVE NORMAL TEMPERATURES
AREAWIDE DURING THE AFTERNOON. EXPECTING SOME TEEN HUMIDITY VALUES
ONCE AGAIN ACROSS THE NORTHEAST AND EAST CENTRAL AREAS. THIS WILL
ADD TO THE CURING GRASS PROCESS ACROSS THE EAST. A FEW SOUTHERLY
BREEZES...SIMILAR TO TODAY WILL BE FOUND ACROSS THE EAST.

THE UPPER HIGH IS EXPECTED TO WEAKEN SLIGHTLY AND MOVE NORTHWARD
SUNDAY INTO MONDAY. MODELS CONTINUE TO SHOW A MODERATELY STRONG BACK
DOOR COLD FRONT UNDERCUTTING THIS HIGH FROM THE EAST AND PUSHING
HIGHER SURFACE MOISTURE WESTWARD. WETTING RAINFALL COVERAGE SHOULD
INCREASE ACCORDINGLY...STARTING ACROSS THE NORTHEAST HALF ON SUNDAY
AND SPREADING INTO CENTRAL AND EVEN SOME WESTERN AREAS ON MONDAY.
MODELS STILL DIFFER A BIT ON THE RAINFALL COVERAGE ACROSS THE
EASTERN PLAINS ON MONDAY. SUSPECT IT WILL BE TOO STABLE THERE FOR
SIGNIFICANT ACTION BUT REALLY DEPENDENT ON THE STRENGTH OF THE BACK
DOOR COLD FRONT. IF IT COMES IN WEAKER THEN ALL BETS ARE OFF. EITHER
WAY...THE EASTERN PLAINS HAVE SOME POTENTIAL FOR WETTING RAIN AND
WOULD HELP EASE THE DRYING CONDITIONS THERE. GAP WINDS SHOULD
ENERGIZE ALONG THE CENTRAL MOUNTAINS SUNDAY NIGHT. HUMIDITY VALUES
WILL GO UP AREAWIDE WITH AN ACCOMPANYING COOLING EFFECT.

BASED ON THE LONGER RANGE MODELS...THE AREA SHOULD EXPERIENCE SOME
SORT OF RECYCLING MODE TUESDAY THROUGH THE END OF THE WEEK. DURING
THIS PERIOD...THE UPPER HIGH WOULD STRENGTHEN SLIGHTLY AND SLIDE A
LITTLE FURTHER TO THE NORTH. DRIER AND MORE STABLE AIR WOULD SLIDE
UNDERNEATH IT AND LOWER WETTING RAIN CHANCES. WILL CONTINUE TO
MONITOR MODEL TRENDS ON THIS BUT STARTING TO SEE RUN TO RUN
CONSISTENCY FOR THE DRIER SCENARIO AFTER MONDAY. TEMPERATURES WOULD WARM
AND HUMIDITY VALUES WOULD LOWER SOME AS A RESULT. VENTILATION RATES
WOULD VARY ACROSS THE AREA. READINGS APPEAR IN THE GRIDS AS BEING
THE LOWEST ON TUESDAY AND WEDNESDAY BUT SOME IMPROVEMENT EXPECTED AS
THE UPPER HIGH MIGRATES NORTHWARD DURING THE LATTER HALF OF THE
WEEK. 50

&&

.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$













AREA FORECAST DISCUSSION

NWS BUFFALO NY

 218 PM EDT SAT AUG 31 2013

.SYNOPSIS...
A SLOW MOVING FRONTAL BOUNDARY WILL MOVE SLOWLY AWAY FROM THE AREA
TONIGHT WITH ANY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ENDING
OVERNIGHT. ANOTHER WEAK AREA OF LOW PRESSURE WILL APPROACH LATER
SUNDAY THEN CROSS THE REGION SUNDAY NIGHT AND LABOR DAY WITH A FEW
MORE SHOWERS AND THUNDERSTORMS...ALTHOUGH THERE WILL BE PLENTY OF
RAIN FREE TIME AS WELL. COOLER AND LESS HUMID AIR WILL THEN ARRIVE
BY TUESDAY WITH EVEN COOLER AIR ARRIVING LATER IN THE WEEK.

&&

.NEAR TERM /THROUGH SUNDAY/...
RADAR IMAGERY THIS AFTERNOON SHOWING A FEW SCATTERED SHOWERS ACROSS
THE HIGHER TERRAIN OF THE SOUTHERN TIER AND EAST OF LAKE ONTARIO...
WITH BETTER COVERAGE ACROSS CENTRAL AND EASTERN NY. WATER VAPOR
IMAGERY AND OBJECTIVE RUC ANALYSIS NOW SHOWS THE AXIS OF THE MID
LEVEL TROUGH FROM CENTRAL NY TO CENTRAL PA...SO BETTER LARGE SCALE
ASCENT SHOULD CONTINUE TO DRIFT EAST TOWARDS EASTERN NY THROUGH LATE
AFTERNOON WITH THE BETTER SHOWER COVERAGE FOLLOWING THIS FEATURE.
BEHIND THE SHORTWAVE...EXTENSIVE MID LEVEL DRYING AND WARMING HAS
PRODUCED AN EFFECTIVE CAP SO FAR.

EVEN WITH THE CAP IN PLACE...PLENTY OF LOW LEVEL MOISTURE WILL STILL
ALLOW A FEW SCATTERED SHOWERS TO FORM BEHIND THE MAIN MID LEVEL
TROUGH. THESE WILL BE MOST PROBABLE ACROSS THE HIGHER TERRAIN OF THE
SOUTHERN TIER...FINGER LAKES...AND EASTERN LAKE ONTARIO REGION
THROUGH EARLY EVENING. AN ISOLATED SHOWER CANNOT BE RULED OUT ON THE
LAKE PLAINS EITHER...ESPECIALLY ALONG THE CONVERGENCE ZONE NOTED IN
LOW LEVEL WINDS FROM THE NIAGARA PENINSULA ACROSS THE NIAGARA
FRONTIER. EVEN SO...MOST AREAS WILL BE MAINLY DRY THROUGH EARLY
EVENING. EXTENSIVE LOW LEVEL MOISTURE WILL KEEP PLENTY OF CLOUDS IN
PLACE WITH ONLY A FEW BREAKS OF SUN AT TIMES. TEMPERATURES WILL TOP
OUT IN THE UPPER 70S TO LOWER 80S IN MOST AREAS WITH MID 70S ACROSS
THE HIGHER TERRAIN AND NORTH COUNTRY.

TONIGHT THE WEAK FRONTAL ZONE WILL CONTINUE TO SAG SLOWLY SOUTHEAST
AWAY FROM THE AREA WHILE THE WEAK WAVE OF LOW PRESSURE MOVES SLOWLY
EAST INTO NEW ENGLAND. THE MID LEVEL SHORTWAVE WILL ALSO WEAKEN
FURTHER AND SLOWLY EXIT THE AREA. WITH THE LOSS OF SUPPORT AND
DIURNAL COOLING EXPECT ANY SHOWERS FROM THE SOUTHERN TIER INTO THE
FINGER LAKES AND EASTERN LAKE ONTARIO REGION TO SLOWLY DRIFT EAST
AND END THROUGH THE FIRST HALF OF THE NIGHT.

MODEL GUIDANCE IS BULLISH WITH LOW LEVEL MOISTURE OVERNIGHT...AND
THIS SEEMS LIKE A REASONABLE SOLUTION GIVEN THE WEALTH OF LOW
STRATUS HANGING JUST NORTH OF LAKE ONTARIO THIS AFTERNOON. WITH A
VERY WEAK LOW LEVEL GRADIENT IN PLACE...THIS MOISTURE FIELD SHOULD
SPREAD SOUTHWARD OVERNIGHT AND INTO OUR REGION. THIS WILL SET THE
STAGE FOR WIDESPREAD STRATUS AND FOG DEVELOPMENT OVERNIGHT. UPS FOG
METHOD ALSO SUPPORTS FOG OVERNIGHT WITH FORECAST LOW TEMPERATURES
CROSSING OVER OUR AFTERNOON DEWPOINTS FAIRLY EARLY IN THE NIGHT.
EXPECT LOWS IN THE MID TO UPPER 60S ON THE LAKE PLAINS WITH LOWER
60S ACROSS THE INTERIOR SOUTHERN TIER AND EAST OF LAKE ONTARIO.

ON SUNDAY THE EXTENSIVE FOG AND LOW STRATUS WILL SLOWLY BURN OFF IN
THE MORNING WITH THE ONSET OF DAYTIME MIXING. THE NEW 12Z
GFS/NAM/GEM SOLUTIONS ARE ALL MUCH FASTER WITH THE NEXT SYSTEM...
ALL LIFTING A CONVECTIVELY AUGMENTED MID LEVEL SHORTWAVE INTO THE
SOUTHERN TIER AND FINGER LAKES DURING THE AFTERNOON. LARGE SCALE
ASCENT WILL INCREASE AHEAD OF THIS SHORTWAVE...AND PWAT WILL RISE TO
AROUND 1.75 INCHES AS A PLUME OF DEEPER MOISTURE ADVECTS NORTHEAST
OUT OF THE OHIO VALLEY IN ADVANCE OF A WEAK SURFACE LOW OVER THE
WESTERN LAKES.

GIVEN THE FASTER SOLUTION...HAVE INCREASED POPS FOR THE AFTERNOON
ESPECIALLY ACROSS THE INTERIOR SOUTHERN TIER AND WESTERN FINGER
LAKES WITH LIKELY POPS BY THE END OF THE AFTERNOON...AND CHANCE POPS
SPREADING NORTH TO KBUF-KROC LATE. OUTSIDE OF THIS BETTER CHANCE OF
RAIN...A FEW ISOLATED SHOWERS MAY DEVELOP EARLIER IN THE DAY FROM
CENTRAL NY INTO THE HIGHER TERRAIN EAST OF LAKE ONTARIO AS SOME
MESOSCALE MODEL GUIDANCE SUGGESTS A WEAK LOW LEVEL CONVERGENCE ZONE
LINGERING IN THAT AREA.

850MB TEMPS ARE STILL UP AROUND +16C...BUT THE EXTENSIVE EARLY
STRATUS AND ADDITIONAL AFTERNOON CLOUD COVER WILL KEEP US FROM
REACHING THE FULL POTENTIAL OF THE WARM AIRMASS. EXPECT HIGHS IN THE
LOWER 80S IN MOST AREAS...WITH MID TO UPPER 70S ACROSS HIGHER
TERRAIN.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
ON SUNDAY...OUR INITIAL WEAK AREA OF LOW PRESSURE WILL EXIT OUT
ACROSS NORTHERN NEW ENGLAND...WHILE A SECOND AND MORE ELONGATED
SURFACE WAVE WILL BE IN THE PROCESS OF PUSHING ACROSS THE WESTERN
AND CENTRAL GREAT LAKES...IN ASSOCIATION WITH A SHORTWAVE TROUGH
DIGGING SOUTHEAST FROM ONTARIO PROVINCE. IN BETWEEN ALL OF THIS...A
WEAK BUBBLE OF HIGH PRESSURE AND SOMEWHAT DRIER AIR WILL BRIEFLY
SETTLE ACROSS WESTERN AND NORTH CENTRAL NEW YORK...AND WILL PROVIDE
OUR REGION WITH THE DRIEST AND NICEST OVERALL DAY OF THE LONG
HOLIDAY WEEKEND. ANY CONVECTIVE POTENTIAL WILL BE FAIRLY LIMITED AND
LARGELY CONFINED TO OUR NORTHEASTERN AND SOUTHWESTERN EXTREMITIES
WHERE MOISTURE WILL BE SOMEWHAT GREATER AT POINTS...WITH THE NORTH
COUNTRY MAINLY SEEING LOWER-END CHANCES IN THE MORNING ON THE TAIL
END OF THE DEPARTING INITIAL WAVE...AND THE SOUTHERN TIER
EXPERIENCING A SIMILAR RISK IN THE AFTERNOON WITH DIURNAL HEATING.
WILL THUS KEEP SOME LOWER-END CHANCE POPS IN PLACE FOR BOTH OF THESE
AREAS...WITH THE REST OF THE REGION MORE LIKELY TO REMAIN MAINLY DRY
THROUGH THE DAY. WITH RESPECT TO TEMPS...850 MB READINGS OF +14C TO
+16C SHOULD YIELD FAIRLY WIDESPREAD HIGHS IN THE LOWER TO MID
80S...WITH THE WARMEST READINGS COMING ACROSS THE GENESEE VALLEY AND
FINGER LAKES.

DURING THE COURSE OF SUNDAY NIGHT AND MONDAY...THE UPSTREAM
SHORTWAVE TROUGH WILL CONTINUE TO DIG FURTHER SOUTHEASTWARD AND
EVENTUALLY ESTABLISH A LARGER-SCALE UPPER TROUGH OVER THE GREAT
LAKES AND NORTHEAST...WITH ITS ATTENDANT COMPLEX AREA OF LOW
PRESSURE GRADUALLY SLIDING EASTWARD ACROSS THE LOWER LAKES AND NEW
YORK STATE. INCREASING MOISTURE OUT AHEAD OF THESE FEATURES WILL
HELP PUSH PWAT LEVELS BACK UP TO AROUND 1.50" FOR A TIME...AND THIS
COUPLED WITH INCREASING SYNOPTIC-SCALE LIFT WILL RESULT IN A 6-12
HOUR WINDOW DURING WHICH CONVECTION WILL BE MORE LIKELY...WITH A
ROUGH MODEL CONSENSUS SUGGESTING THAT THIS SHOULD COME BETWEEN 06Z
AND 18Z MONDAY. HAVE THEREFORE CONTINUED WITH WIDESPREAD LIKELY POPS
FOR THIS TIME FRAME...ALONG WITH A MENTION OF THE POTENTIAL FOR SOME
LOCALLY HEAVIER RAINFALL GIVEN THE AFOREMENTIONED PRECIPITABLE WATER
VALUES.

FOLLOWING THIS...CONVECTIVE POTENTIAL SHOULD THEN WANE FROM WEST TO
EAST MONDAY AFTERNOON AND EVENING FOLLOWING THE PASSAGE OF THE MAIN
SURFACE TROUGH AXIS...WITH MAINLY DRY CONDITIONS RETURNING TO THE
BULK OF THE AREA FOR THE SECOND HALF OF MONDAY NIGHT. THIS SAID...
SKIES SHOULD REMAIN FAIRLY CLOUDY THROUGH THE NIGHT AS THE NAM/GFS/
ECMWF ALL SUGGEST THAT A FAIR AMOUNT OF MOISTURE WILL REMAIN IN
PLACE BELOW 850 MB...WHICH IN COMBINATION WITH A NORTHWESTERLY
UPSLOPE FLOW AND PROGRESSIVELY COOLER AIR ALOFT SHOULD BE SUPPORTIVE
OF A LINGERING STRATOCU DECK. WITH THIS IN MIND...HAVE BUMPED UP THE
AMOUNT OF SKY COVER SOME 20-30 PERCENT FOR MONDAY NIGHT.
OTHERWISE...EXPECT CONDITIONS TO TREND LESS HUMID AND NOTICEABLY
COOLER MONDAY NIGHT AS A MUCH COOLER AIRMASS INFILTRATES THE REGION
IN THE WAKE OF THE DEPARTING SURFACE TROUGH...WITH NIGHTTIME LOWS
FALLING BACK TO WITHIN A FEW DEGREES OF 60 AREAWIDE.

ON TUESDAY...OUR AREA WILL REMAIN FIRMLY UNDER THE INFLUENCE OF THE
LINGERING UPPER TROUGH AND ASSOCIATED COOL POOL...WITH 850 MB TEMPS
OF AROUND +8C SUPPORTING HIGHS RANGING WITHIN A FEW DEGREES OF 70.
WITH DIURNAL HEATING OF OUR MUCH COOLER AIRMASS AND THE UPPER TROUGH
AXIS REMAINING IN OUR VICINITY...EXPECT THAT THE LINGERING STRATOCU
DECK TUESDAY MORNING WILL MERELY TRANSITION TO A BROKEN CU FIELD
OVER TIME...WITH SOME OF THESE POSSIBLY DEVELOPING ENOUGH DURING THE
MIDDAY/AFTERNOON HOURS TO PRODUCE SOME SCATTERED LIGHT SHOWERS. HAVE
THUS RETAINED SOME LOW CHANCE POPS TO COVER THIS POTENTIAL...THOUGH
HAVE REMOVED ANY MENTION OF THUNDER AS INSTABILITY LEVELS APPEAR TO
BE FAR TOO LOW TO SUPPORT THIS.

ANY LIGHT SHOWERS AND DIURNALLY-DRIVEN CU SHOULD THEN QUICKLY
DISSIPATE LATE TUESDAY AFTERNOON/EARLY TUESDAY EVENING WITH THE LOSS
OF HEATING AND AS HIGH PRESSURE/MUCH DRIER AIR QUICKLY RIDGES
EASTWARD FROM THE OHIO VALLEY AND CENTRAL GREAT LAKES. THIS SHOULD
RESULT IN A RETURN TO PARTLY CLOUDY SKIES AND DRY WEATHER FOR THE
MAJORITY OF TUESDAY NIGHT...WITH NIGHTTIME LOWS SETTLING BACK TO
EVEN MORE COMFORTABLE LEVELS IN THE LOWER TO MID 50S.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
ON WEDNESDAY...A BRIEF PERIOD OF MODEST WARM AIR ADVECTION WILL
OVERSPREAD OUR REGION AS THE AFOREMENTIONED SURFACE RIDGE SETTLES
ACROSS THE CAROLINAS...AND A SECONDARY COLD FRONT DROPS
SOUTHEASTWARD ACROSS ONTARIO AND QUEBEC PROVINCES. UNDER THE
INFLUENCE OF THE RESULTANT BROAD WESTERLY FLOW...850 MB TEMPS LOOK
TO RECOVER BACK TO AROUND +12C...WHICH COUPLED WITH A DECENT
AMOUNT OF SUNSHINE SHOULD RESULT IN HIGH TEMPS CLIMBING BACK TO
NEAR NORMAL LEVELS IN THE MID 70S IN MOST LOCATIONS.

AFTER THAT...THE PAST FEW RUNS OF THE GFS/ECMWF HAVE BEEN IN GOOD
AGREEMENT THAT THE SECONDARY COLD FRONT WILL DROP SOUTHEAST ACROSS
OUR REGION BETWEEN WEDNESDAY NIGHT AND EARLY THURSDAY. AS THIS
FEATURE LOOKS TO BE RELATIVELY MOISTURE STARVED AND LACKING MUCH IN
THE WAY OF UPPER LEVEL SUPPORT...HAVE KEPT ASSOCIATED SHOWER
PROBABILITIES CONFINED TO THE SLIGHT CHANCE TO LOW-END CHANCE
RANGE...WITH THE BEST PRECIP CHANCES COMING ACROSS THE NORTH COUNTRY
AND FAR EASTERN FINGER LAKES WHERE MOISTURE WILL BE THE DEEPEST.

FOLLOWING THE PASSAGE OF THIS SECONDARY FRONT...A REINFORCING SHOT
OF MUCH COOLER/DRIER AIR WILL SETTLE SOUTH ACROSS OUR REGION FOR
BOTH THURSDAY AND FRIDAY. THIS WILL RESULT IN RETURN TO DRY WEATHER
FOR THE END OF THE WORK WEEK...WITH TEMPERATURES ALSO FALLING BACK
TO BELOW NORMAL BUT ALSO COMFORTABLE LEVELS. MORE SPECIFICALLY...
DAYTIME HIGHS WILL SETTLE BACK TO THE MID 60S TO LOWER 70S FOR BOTH
DAYS...WHILE NIGHTTIME LOWS DROP INTO THE MID 40S TO LOWER 50S
THURSDAY NIGHT.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
A SLOW MOVING FRONTAL ZONE AND WEAK WAVE OF LOW PRESSURE WILL
CONTINUE TO DRIFT ACROSS THE AREA THIS AFTERNOON. THIS WILL PRODUCE
A FEW SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS...MAINLY FROM THE
HIGHER TERRAIN OF THE SOUTHERN TIER THROUGH THE FINGER LAKES TO THE
EASTERN LAKE ONTARIO REGION...WITH VERY LOW COVERAGE IF ANYTHING AT
ALL FROM KBUF-KROC. A WEALTH OF LOW LEVEL MOISTURE WILL CONTINUE TO
SUPPORT PLENTY OF STRATUS AND STRATOCUMULUS THIS AFTERNOON WITH
MAINLY VFR CIGS ACROSS LOWER ELEVATIONS AND MVFR ACROSS THE HIGHER
TERRAIN AND NORTH COUNTRY.

TONIGHT ANY SHOWERS WILL GRADUALLY END FROM NORTHWEST TO SOUTHEAST
AS THE FRONTAL ZONE SLOWLY LEAVES THE AREA. MODEL GUIDANCE IS
BULLISH WITH LOW LEVEL MOISTURE OVERNIGHT...AND THIS SEEMS PLAUSIBLE
GIVEN THE AMOUNT OF LOW STRATUS JUST UPSTREAM ACROSS SOUTHERN
ONTARIO...POISED TO MOVE INTO OUR REGION OVERNIGHT. WITH THIS IN
MIND...EXPECT WIDESPREAD IFR DEVELOPMENT TONIGHT WITH BOTH STRATUS
AND FOG DEVELOPING. THE FOG AND STRATUS WILL SLOWLY BURN OFF SUNDAY
MORNING WITH A RETURN TO VFR BY MIDDAY.

LATER SUNDAY AFTERNOON MODEL GUIDANCE IS NOW MUCH FASTER IN BRINGING
IN THE NEXT WEAK SYSTEM...WITH SHOWER AND THUNDERSTORM CHANCES
INCREASING LATER IN THE DAY ESPECIALLY FROM THE SOUTHERN TIER INTO
THE GENESEE VALLEY AND FINGER LAKES WITH ASSOCIATED BRIEF MVFR/IFR
CONDITIONS WITH ANY HEAVIER RAINFALL.

OUTLOOK...
SUNDAY NIGHT...VFR/MVFR WITH A FEW SHOWERS AND THUNDERSTORMS LIKELY
WITH ASSOCIATED BRIEF MVFR/IFR.
MONDAY...A FEW SHOWERS AND THUNDERSTORMS LIKELY WITH ASSOCIATED
BRIEF IFR/MVFR.
TUESDAY...MAINLY VFR WITH A CHANCE OF A FEW SHOWERS.
WEDNESDAY...MAINLY VFR.
WEDNESDAY NIGHT...VFR/MVFR WITH A CHANCE OF SHOWERS.
THURSDAY...IMPROVING TO VFR.

&&

.MARINE...
NORTHERLY FLOW IN THE 5 TO 10 KNOT RANGE WILL CONTINUE TONIGHT ON
LAKES ERIE AND ONTARIO BEHIND A WEAK FRONTAL BOUNDARY WHICH WILL
SLOWLY EXIT THE AREA. SOME FOG MAY FORM OVERNIGHT INTO SUNDAY
MORNING LIMITING VISIBILITY IN SOME SPOTS.

LIGHT WINDS WILL CONTINUE ON SUNDAY WITH A WEAK PRESSURE GRADIENT IN
PLACE. SOUTHWEST WINDS WILL INCREASE SOME ON MONDAY AS A WEAK AREA
OF LOW PRESSURE CROSSES THE LOWER LAKES...BUT CONDITIONS ARE
EXPECTED TO REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA.
SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE AT TIMES FROM LATER
SUNDAY AFTERNOON THROUGH MONDAY...WITH LOCALLY HIGHER WINDS AND
WAVES POSSIBLE.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...HITCHCOCK
NEAR TERM...HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...HITCHCOCK
MARINE...HITCHCOCK






AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 1101 AM EDT SAT AUG 31 2013

.SYNOPSIS...
MUGGY AND UNSETTLED WEATHER WILL CONTINUE THROUGH LABOR DAY...WITH
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED ON A DAILY
BASIS. A COLD FRONT SHOULD CROSS THE REGION MONDAY NIGHT OR EARLY
TUESDAY...WITH COOLER TEMPERATURES TO FOLLOW BY THE MIDDLE OF NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1045 AM UPDATE...
ONLY ISOLD SHOWERS THIS MRNG ACRS SUSQUEHANNA REGION UNDER CLDY
SKIES. 12Z MODELS SHOWING CLDS HANGING TUFF THRU THE DAY AS
MOISTURE CONTS TO PUMP UP ALONG BNDRY. SOME DRYING EXPECTED AT
MID-LEVELS THIS AFTN BUT MOISTURE WL RMN LOCKED INTO BLYR. THUS HV
GONE MORE PESSIMISTIC WITH SKY CVR, THO AREAS TO THE SOUTH MAY SEE
BREAKS AT SOME POINT TDA.

HV DROPPED POPS TO ISOLD-SCTD FOR THIS AFTN AS IT WL BE HARD TO
GET ANY THUNDER TO DVLP. HWVR WITH BNDRY LURKING NR THE AREA AND
DWPTS POOLING IN THE 70S ALONG IT AND TEMPS EXPECTED TO CLIMB TO
LWR 80S THIS AFTN, SEEING CAPES ALREADY ARND 1500 J/KG. WEAK MID-
LVL LAPSE RATES ALONG WITH LACK OF HTG AND ANY UL FRCG HARD TO
JUSTIFY LKLY POPS AT THIS POINT. ALSO LWRD MAX TEMPS BY A DEGREE
OR TWO.

PREV DISCO BLO...

5 AM SAT UPDATE... SHWRS/TSTMS CONTINUE TO GRADUALLY DIMINISH IN
COVERAGE EARLY THIS MRNG...AS A LEAD S/WV IMPULSE HAS MOVED TO THE
E...AND THE AMS HAS STABILIZED. WE EXPECT FAIRLY MINIMAL (ISOLD) COVERAGE
FOR THE REST OF THE MRNG...INTO THE EARLY AFTN HRS.

BY/AFTER 18Z...WE SHOULD SEE AN UPTICK IN CONVECTIVE ACTIVITY ONCE
AGN...OWING TO PEAK HEATING/RESULTANT DESTABILIZATION...AND THE
PASSAGE OF ANOTHER S/WV FROM THE ERN LAKES RGN. ML CAPE VALUES OF
1000-2000 J/KG ARE LIKELY...BUT PROGGED DEEP-LYRD SHEAR LOOKS
FAIRLY WEAK (15-20 KT). THUS...TRULY ORGANIZED STORMS SEEM
UNLIKELY...WITH MORE OF THE PULSE VARIETY ANTICIPATED. GIVEN PWAT
VALUES NEAR 1.75"...AND MBE VECTORS AOB 10 KT FOR A TIME LTR
TDY...LOCALIZED HEAVY DOWNPOURS WOULD APPEAR TO BE THE MAIN
CONSEQUENCE.

A FAIR AMT OF CONVECTIVE DEBRIS COVERS THE FA ATTM...AND ALTHOUGH
THESE CLDS MAY THIN OUT SOME TDY (SPCLY ACRS NE PA)...MORE
PERSISTENT CLOUD COVER SHOULD LIMIT HEATING A LTL BIT...AS
COMPARED TO RECENT DAYS. HIGH TEMPS SHOULD RANGE FROM THE MID 70S
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TUG AND CATSKILL
RGNS...TO THE MID 80S IN PARTS OF THE FINGER LKS RGN...AND DOWN
ACRS THE WYO/LACK VLYS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
530 AM SAT UPDATE... ONCE THE ABV REFERENCED S/WV PUSHES OFF TO
THE TNT...WE SHOULD SEE A DECREASE IN SHWR/TSTM ACTIVITY. THIS
LULL MAY WELL LAST THROUGH MUCH OF THE DAY SUN...GIVEN A RELATIVE
LACK OF MID TO UPR-LVL FORCING. THERE WILL...HOWEVER...CONTINUE
TO BE A FRNTL BNDRY PERCHED JUST TO OUR N AND W THIS PD...SO AN
ISOLD SHWR/TSTM CAN`T BE RULED OUT...AND WE`LL THUS CONTINUE TO
CARRY MOSTLY 15-25% POPS.

BY MON...MODEL AGREEMENT REMAINS FAIRLY GOOD...THAT THE MAIN L/WV
TROUGH WILL DEEPEN INTO THE GREAT LKS RGN...HELPING TO PUSH A
SOMEWHAT STGR COLD FRNT EWD TWDS NY/PA. AS THIS FRNT APPROACHES
FROM THE NW...AND IMPROVED UPR JET DYNAMICS EVOLVE ACRS CNY/NE PA
DURG THE DAY MON...WE SHOULD SEE MORE WIDESPREAD SHWRS/TSTMS ONCE
AGN. AS A RESULT...WE`LL CONTINUE TO ADVERTISE LIKELY POPS (NEAR
60%).

DEPENDING ON THE DEGREE OF HEATING/DESTABILIZATION...LOCALLY
STG/SVR STORMS WOULD BE PSBL...GIVEN BETTER FORCED LIFT AND VERT
SHEAR. THE AMT OF INSOLATION IS IN QUESTION...THOUGH...AS WE COULD
SEE A FAIR AMT OF PRE-FRNTL CLOUD COVER. ALSO...THE MODELS
CONTINUE TO ADVERTISE THE DVLPMT OF A PRE-FRNTL/LEE-SIDE TROUGH ON
MON AFTN...FROM ERN PA SWD INTO THE DELMARVA RGN. IT`S ALSO
UNCLEAR ATTM HOW MUCH OF AN IMPACT THIS FEATURE WILL HAVE ON TSTM
EVOLUTION/INTENSITY IN OUR CWA.

ALTHOUGH IT WILL REMAIN MUGGY ON MON (SFC DEW PTS 65-70F)...MAX
TEMPS MAY BE A LTL LWR THAN PREV DAYS (MID 70S-LWR 80S)...GIVEN
THE POTENTIAL FOR MORE CLOUD COVER.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
315 PM EDT UPDATE...
MADE MINOR ADJUSTMENTS TO PREVIOUS FORECASTS. MODELS THIS
AFTERNOON AGAIN ARE IN GOOD AGREEMENT WITH MID WEEK BUT DISAGREE
GREATLY IN THE EXTENDED. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE THROUGH LATE TUESDAY NIGHT. WENT WITH MORE OF A ECMWF/CMC
BLEND. LEANED MORE TOWARDS ECMWF GUIDANCE SINCE THIS MODEL HAS
BEEN MOST CONSISTENT WITH PREVIOUS RUNS. TUESDAY A COLD FRONT WILL
PASS THROUGH THE REGION BRINGING CAA TO THE NE PA AND C NY. MODELS
STILL DIFFER GREATLY IN THE EXTENDED SO WENT WITH A CONSERVATIVE
PERSPECTIVE TO TEMPS WITH LOWS IN THE UPPER 40S TO LOW 50S AND
HIGHS IN THE UPPER 60S TO LOW 70S WED THRU FRIDAY.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
SHOWER ACTIVITY IS PULLING EAST THIS MORNING. TEMPERATURES
REMAINED UNUSUALLY MILD OVERNIGHT, RESULTING IN LARGER THAN
EXPECTED TDD SPREADS AND A LACK OF FOG DEVELOPMENT.

A BROKEN 5000 FT TO 10000 FT DECK WILL BE OVERHEAD TODAY. HRRR IS
PREDICTING SHOWERS TO BLOSSOM OVER TERMINALS BETWEEN 13Z AND 15Z,
BUT THERE APPEARS LITTLE SUPPORT FOR THIS. SO WILL STICK TO A
MAINLY DRY FORECAST THROUGH EARLY AFTERNOON WITH ISOLATED SHOWER
ACTIVITY NOT LIKELY TO DIRECTLY AFFECT TERMINALS.

THUNDERSTORMS MAY BRING MVFR RESTRICTIONS LATE THIS AFTERNOON. THE
BEST CHANCE FOR THUNDER WILL BE BETWEEN 18Z AND 22Z DURING PEAK
HEATING.

OUTLOOK...

SUN-WED...POTENTIAL FOR MVFR IN SCTD SHRA/TSRAS.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...MLJ
NEAR TERM...MLJ/PVN
SHORT TERM...MLJ
LONG TERM...KAH
AVIATION...DJP







AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 632 AM EDT SAT AUG 31 2013

.SYNOPSIS...
MUGGY AND UNSETTLED WEATHER WILL CONTINUE THROUGH LABOR DAY...WITH
AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED ON A DAILY
BASIS. A COLD FRONT SHOULD CROSS THE REGION MONDAY NIGHT OR EARLY
TUESDAY...WITH COOLER TEMPERATURES TO FOLLOW BY THE MIDDLE OF NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
5 AM SAT UPDATE... SHWRS/TSTMS CONTINUE TO GRADUALLY DIMINISH IN
COVERAGE EARLY THIS MRNG...AS A LEAD S/WV IMPULSE HAS MOVED TO THE
E...AND THE AMS HAS STABILIZED. WE EXPECT FAIRLY MINIMAL (ISOLD) COVERAGE
FOR THE REST OF THE MRNG...INTO THE EARLY AFTN HRS.

BY/AFTER 18Z...WE SHOULD SEE AN UPTICK IN CONVECTIVE ACTIVITY ONCE
AGN...OWING TO PEAK HEATING/RESULTANT DESTABILIZATION...AND THE
PASSAGE OF ANOTHER S/WV FROM THE ERN LAKES RGN. ML CAPE VALUES OF
1000-2000 J/KG ARE LIKELY...BUT PROGGED DEEP-LYRD SHEAR LOOKS
FAIRLY WEAK (15-20 KT). THUS...TRULY ORGANIZED STORMS SEEM
UNLIKELY...WITH MORE OF THE PULSE VARIETY ANTICIPATED. GIVEN PWAT
VALUES NEAR 1.75"...AND MBE VECTORS AOB 10 KT FOR A TIME LTR
TDY...LOCALIZED HEAVY DOWNPOURS WOULD APPEAR TO BE THE MAIN
CONSEQUENCE.

A FAIR AMT OF CONVECTIVE DEBRIS COVERS THE FA ATTM...AND ALTHOUGH
THESE CLDS MAY THIN OUT SOME TDY (SPCLY ACRS NE PA)...MORE
PERSISTENT CLOUD COVER SHOULD LIMIT HEATING A LTL BIT...AS
COMPARED TO RECENT DAYS. HIGH TEMPS SHOULD RANGE FROM THE MID 70S
ACROSS THE HIGHER TERRAIN OF THE SOUTHERN TUG AND CATSKILL
RGNS...TO THE MID 80S IN PARTS OF THE FINGER LKS RGN...AND DOWN
ACRS THE WYO/LACK VLYS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
530 AM SAT UPDATE... ONCE THE ABV REFERENCED S/WV PUSHES OFF TO
THE TNT...WE SHOULD SEE A DECREASE IN SHWR/TSTM ACTIVITY. THIS
LULL MAY WELL LAST THROUGH MUCH OF THE DAY SUN...GIVEN A RELATIVE
LACK OF MID TO UPR-LVL FORCING. THERE WILL...HOWEVER...CONTINUE
TO BE A FRNTL BNDRY PERCHED JUST TO OUR N AND W THIS PD...SO AN
ISOLD SHWR/TSTM CAN`T BE RULED OUT...AND WE`LL THUS CONTINUE TO
CARRY MOSTLY 15-25% POPS.

BY MON...MODEL AGREEMENT REMAINS FAIRLY GOOD...THAT THE MAIN L/WV
TROUGH WILL DEEPEN INTO THE GREAT LKS RGN...HELPING TO PUSH A
SOMEWHAT STGR COLD FRNT EWD TWDS NY/PA. AS THIS FRNT APPROACHES
FROM THE NW...AND IMPROVED UPR JET DYNAMICS EVOLVE ACRS CNY/NE PA
DURG THE DAY MON...WE SHOULD SEE MORE WIDESPREAD SHWRS/TSTMS ONCE
AGN. AS A RESULT...WE`LL CONTINUE TO ADVERTISE LIKELY POPS (NEAR
60%).

DEPENDING ON THE DEGREE OF HEATING/DESTABILIZATION...LOCALLY
STG/SVR STORMS WOULD BE PSBL...GIVEN BETTER FORCED LIFT AND VERT
SHEAR. THE AMT OF INSOLATION IS IN QUESTION...THOUGH...AS WE COULD
SEE A FAIR AMT OF PRE-FRNTL CLOUD COVER. ALSO...THE MODELS
CONTINUE TO ADVERTISE THE DVLPMT OF A PRE-FRNTL/LEE-SIDE TROUGH ON
MON AFTN...FROM ERN PA SWD INTO THE DELMARVA RGN. IT`S ALSO
UNCLEAR ATTM HOW MUCH OF AN IMPACT THIS FEATURE WILL HAVE ON TSTM
EVOLUTION/INTENSITY IN OUR CWA.

ALTHOUGH IT WILL REMAIN MUGGY ON MON (SFC DEW PTS 65-70F)...MAX
TEMPS MAY BE A LTL LWR THAN PREV DAYS (MID 70S-LWR 80S)...GIVEN
THE POTENTIAL FOR MORE CLOUD COVER.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
315 PM EDT UPDATE...
MADE MINOR ADJUSTMENTS TO PREVIOUS FORECASTS. MODELS THIS
AFTERNOON AGAIN ARE IN GOOD AGREEMENT WITH MID WEEK BUT DISAGREE
GREATLY IN THE EXTENDED. SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE THROUGH LATE TUESDAY NIGHT. WENT WITH MORE OF A ECMWF/CMC
BLEND. LEANED MORE TOWARDS ECMWF GUIDANCE SINCE THIS MODEL HAS
BEEN MOST CONSISTENT WITH PREVIOUS RUNS. TUESDAY A COLD FRONT WILL
PASS THROUGH THE REGION BRINGING CAA TO THE NE PA AND C NY. MODELS
STILL DIFFER GREATLY IN THE EXTENDED SO WENT WITH A CONSERVATIVE
PERSPECTIVE TO TEMPS WITH LOWS IN THE UPPER 40S TO LOW 50S AND
HIGHS IN THE UPPER 60S TO LOW 70S WED THRU FRIDAY.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHOWER ACTIVITY IS PULLING EAST THIS MORNING. TEMPERATURES
REMAINED UNUSUALLY MILD OVERNIGHT, RESULTING IN LARGER THAN
EXPECTED TDD SPREADS AND A LACK OF FOG DEVELOPMENT.

A BROKEN 5000 FT TO 10000 FT DECK WILL BE OVERHEAD TODAY. HRRR IS
PREDICTING SHOWERS TO BLOSSOM OVER TERMINALS BETWEEN 13Z AND 15Z,
BUT THERE APPEARS LITTLE SUPPORT FOR THIS. SO WILL STICK TO A
MAINLY DRY FORECAST THROUGH EARLY AFTERNOON WITH ISOLATED SHOWER
ACTIVITY NOT LIKELY TO DIRECTLY AFFECT TERMINALS.

THUNDERSTORMS MAY BRING MVFR RESTRICTIONS LATE THIS AFTERNOON. THE
BEST CHANCE FOR THUNDER WILL BE BETWEEN 18Z AND 22Z DURING PEAK
HEATING.

OUTLOOK...

SUN-WED...POTENTIAL FOR MVFR IN SCTD SHRA/TSRAS.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...MLJ
LONG TERM...KAH
AVIATION...DJP







AREA FORECAST DISCUSSION

NWS RALEIGH NC

 256 PM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM AND MOIST SOUTHERLY FLOW WILL PREVAIL THROUGH THE REST OF THE
WEEKEND. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST ON
MONDAY...THEN PUSH SLOWLY EAST THROUGH THE CAROLINAS ON TUESDAY. IN
THE WAKE OF THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION ON
WEDNESDAY AND LINGER THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM SATURDAY...

OVERVIEW:
LIGHT NW FLOW ALOFT WILL PREVAIL ACROSS THE REGION THROUGH
TONIGHT...IN A WEAKNESS BETWEEN AN UPSTREAM RIDGE OVER THE SOUTHERN
PLAINS/ROCKIES AND A DOWNSTREAM RIDGE OFFSHORE THE SOUTHEAST COAST.
17Z WV IMAGERY AND RAP DATA INDICATED SMALL AMPLITUDE DISTURBANCES
UPSTREAM ACROSS OH/KY/WV...TRACKING SOUTHEAST TOWARD THE MID-
ATLANTIC AND NORTHERN PORTIONS OF NC.

PRECIPITATION CHANCES:
THE LOW-LEVEL RIDGE EXTENDING WESTWARD INTO CENTRAL NC THIS MORNING
HAS FURTHER WEAKENED...GIVING WAY TO AN INCREASINGLY MOIST SOUTHERLY
RETURN FLOW FROM THE SFC-925 MB...WITH ADDITIONAL MOISTURE ADVECTING
INTO THE AREA FROM THE WEST/WNW AT H85. SEASONABLY STRONG INSOLATION
WILL RESULT IN MARGINAL TO MODERATE DIURNAL DESTABILIZATION BY PEAK
HEATING WITH MLCAPE VALUES RANGING FROM 1500-2000 J/KG IN THE
WESTERN PIEDMONT TO 500-1000 J/KG IN THE EAST WHERE THE LOW-LEVELS
ARE DRIER AS NOTED ABOVE. THE PRIMARY UNCERTAINTY W/REGARD TO
CONVECTION WILL BE FORCING. VERY LITTLE IF ANY LOW-LEVEL FORCING
WILL BE PRESENT THIS AFT/EVE WITH LARGELY UNIDIRECTIONAL SFC-925 MB
FLOW OVER CENTRAL NC. ADDITIONALLY...UPPER LEVEL FORCING /DPVA/ IS
EXPECTED TO REMAIN N/NW OF CENTRAL NC THIS AFT/EVE AS SMALL
AMPLITUDE DISTURBANCES TRACK SLOWLY E/ESE FROM THE OH VALLEY INTO
THE WV AND CENTRAL/WESTERN VA. AN MCV AND A ROBUST COLD POOL ASSOC/W
AN ONGOING MCS UPSTREAM OVER EASTERN KY AND SOUTHWEST VA AT 17Z IS
LIKELY TO TRACK SOUTHEASTWARD TOWARD NORTHWEST NC AND MAY PROVIDE
SUFFICIENT FORCING FOR CONVECTION TO DEVELOP IN THE NW PIEDMONT LATE
THIS AFT/EVE (22-04Z). WITH THE ABOVE IN MIND...WILL INDICATE PRECIP
CHANCES OF 20-30% WEST OF THE HWY 1 CORRIDOR WITH THE RELATIVE BEST
CHANCE IN THE TRIAD. EAST OF HWY 1...GIVEN A PROFOUND LACK OF
FORCING AND A DRIER LOW-LEVEL AIRMASS /MARGINAL DESTABILIZATION/...
WILL KEEP THE FCST DRY. CHANCES FOR CONVECTION WILL DECREASE BY
MIDNIGHT IN ASSOC/W INCREASING NOCTURNAL STABILIZATION...THOUGH IF
SMALL AMPLITUDE DISTURBANCES AND/OR THE AFOREMENTIONED MCV GRAZE OR
TRACK ACROSS NORTHERN PORTIONS OF CENTRAL NC THERE MAY BE SUFFICIENT
MOISTURE/INSTABILITY TO SUPPORT ISOLD CONVECTION OVERNIGHT...AND
THIS WILL BE THE BASIS FOR A 20% CHANCE OF SHOWERS NORTH OF HWY 64
AFTER MIDNIGHT.

TEMPERATURES:
EXPECT HIGHS TODAY SLIGHTLY ABOVE NORMAL...IN THE MID/UPPER 80S TO
NEAR 90F. LOWS TONIGHT A FEW DEGREES ABOVE NORMAL DUE TO INCREASING
LOW-LEVEL MOISTURE AND PERHAPS MID/UPPER LEVEL CLOUD COVER...IN THE
UPPER 60S TO NEAR 70F.

SEVERE POTENTIAL:
A VERY SMALL (ALBEIT CONDITIONAL) THREAT OF AN ISOLD SEVERE
DOWNBURST EXISTS IN THE FAR W/NW PIEDMONT LATE THIS AFT/EVE WHERE
MODERATE INSTABILITY (1500-2000 J/KG) AND MODERATE DCAPE (1000 J/KG)
ARE PRESENT IN ADVANCE OF THE MCS /COLD POOL/ APPROACHING THE
NORTHWEST NC MOUNTAINS. CONFIDENCE IS LOW WITH REGARD TO HOW THE
AFOREMENTIONED COLD POOL WILL EVOLVE AND WHETHER OR NOT IT WILL
AFFECT THE NW PIEDMONT IN VICINITY OF PEAK HEATING...AND HAVE OPTED
TO LEAVE OUT ANY MENTION OF SVR WX IN THE HWO. -VINCENT

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 215 PM SATURDAY...

CYCLONIC FLOW ALOFT WILL STRENGTHEN ACROSS THE EASTERN CONUS AS
POTENT SHORTWAVE ENERGY TRACKING FROM SOUTHERN CANADA INTO THE UPPER
MIDWEST THIS AFTERNOON DIGS SOUTHEAST INTO THE UPPER GREAT LAKES ON
SUNDAY. AS A RESULT...A MOIST SOUTHWESTERLY LOW-LEVEL FLOW WILL
STRENGTHEN OVER THE CAROLINAS ON SUNDAY...WITH PWAT VALUES
INCREASING TO ABOVE NORMAL IN THE 1.75-2.00" RANGE AND DIURNAL
DESTABILIZATION YIELDING MARGINAL TO MODERATE INSTABILITY (1000-2000
J/KG MLCAPE) DURING PEAK HEATING. LOW-LEVEL FORCING ON SUNDAY WILL
BE ANEMIC ONCE AGAIN WITH LARGELY UNIDIRECTIONAL LOW-LEVEL FLOW...
THOUGH WITH STRONGER CYCLONIC FLOW ALOFT AND DEEPER MOISTURE ONE
WOULD EXPECT PRECIP CHANCES HIGHER THAN TODAY. ULTIMATELY...PRECIP
CHANCES WILL LIKELY DEPEND ON UPSTREAM DEVELOPMENT ACROSS THE HIGHER
TERRAIN IN WESTERN NC AND/OR THE TIMING OF SMALL AMPLITUDE
DISTURBANCES EMBEDDED IN CYCLONIC FLOW ALOFT. WILL INDICATE A 30-40%
CHANCE OF SHOWERS/STORMS SUNDAY AFT/EVE...HIGHEST IN NORTHERN
PORTIONS OF THE AREA...WITH A SLIGHT CHANCE OF SHOWERS PERSISTING
AFTER MIDNIGHT GIVEN CYCLONIC FLOW ALOFT AND DEEP MOISTURE IN THE
PRESENCE OF MARGINAL INSTABILITY. HIGHS ON SUN SIMILAR TO TODAY...
PERHAPS SLIGHTLY WARMER IF CLOUD COVER IS NOT PERVASIVE DURING THE
AFTERNOON...IN THE UPPER 80S TO NEAR 90F...WARMEST IN THE SANDHILLS
AND COASTAL PLAIN. LOWS SUN NIGHT A FEW DEGREES ABOVE NORMAL DUE TO
CLOUD COVER AND DEEP MOISTURE...IN THE LOWER 70S. -VINCENT

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 255 PM SATURDAY...

THE LONG TERM WILL BE CHARACTERIZED BY A FAIRLY STAGNANT UPPER LEVEL
PATTERN CONSISTING OF STRONG HIGH PRESSURE OVER THE SOUTHWESTERN
UNITED STATES AND A NEAR STATIONARY UPPER LEVEL TROUGH OVER THE EAST
COAST. THE FIRST HALF OF THE LONG TERM WILL SEE A SLOW DEEPENING OF
THE TROUGH THROUGH WEDNESDAY BEFORE A GRADUAL LIFTING FOR THE END OF
THE WEEK AND INTO THE WEEKEND. AT THE SURFACE A LOW PRESSURE SYSTEM
OVER THE NORTHERN GREAT LAKES WILL TRACK VERY SLOWLY EASTWARD
THROUGH SOUTHERN QUEBEC WITH A COUPLE OF ASSOCIATED COLD FRONTS
STRETCHED ACROSS THE EASTERN CONUS. EARLY IN THE PERIOD THE BERMUDA
HIGH WILL HELP TRANSPORT MOISTURE OUT OF THE GULF OF MEXICO AND
CARIBBEAN SEA INTO THE SOUTHEASTERN US BEFORE IT MOVES FURTHER OUT
TO SEA...HELPING TO DRY CONDITIONS OUT BY THE END OF THE WEEK.

MONDAY WILL BEGIN WITH TWO FRONTAL SYSTEMS...ONE ON EITHER SIDE OF
THE CWA WITH THE LEAD FRONT OFF THE COAST AND THE TRAILING FRONT
BACK ACROSS THE OHIO AND LOWER MISSISSIPPI VALLEYS. MODEL FORECAST
SOUNDINGS VIEWED IN BUFKIT SHOW AN ELEVATED MIXED LAYER PRESENT FROM
ROUGHLY 800 MB UP TO 600 MB WHICH GREATLY INCREASES INSTABILITY...ON
THE ORDER OF 1500-2000 J/KG. MID-LEVEL LAPSE RATES OF 6-7 DEGREES
PER KM AND PRECIPITABLE WATER VALUES OF AROUND 1.75 INCHES ALL
INDICATE THE POTENTIAL FOR CONVECTION. HAIL AND WINDS COULD BOTH BE
A POSSIBILITY AS THE HAIL GROWTH ZONE BECOMES FAIRLY SATURATED BY
AFTERNOON. IN ADDITION DCAPE VALUES BETWEEN KRDU AND KGSO SHOULD BE
BETWEEN 1000 AND 1500 J/KG. DESPITE THIS...SHEAR WILL BE
MINIMAL...WITH BULK VALUES 15-20 KNOTS AT BEST. WHILE WIDESPREAD
CONVECTION IS NOT LIKELY...THE WILL BE A CHANCE OF SCATTERED STORMS
WITH A FEW OF THEM POTENTIALLY BECOMING SEVERE. HIGHS IN THE LOW
90S...LOWS UPPER 70S.

ALTHOUGH THERE IS SOME DISCREPANCIES IN MODEL TIMING AND
LOCATION...THE NEWEST RUN OF THE GFS SUGGESTS THE FRONT WILL BE
SOMEWHERE IN BETWEEN RALEIGH AND FAYETTEVILLE BY PEAK HEATING AND
WHILE ISOLATED TO SCATTERED CONVECTION CANT BE RULED OUT IN THE
EXTREME SOUTHEAST IT LOOKS LIKE A MUCH DRIER AIRMASS WILL TAKE OVER
MOST OF THE CWA WITH VERY LIMITED INSTABILITY AND SHEAR. COOLER AND
DRIER CONDITIONS WILL BEGIN TO FILTER INTO THE AREA...HIGHS MID TO
UPPER 80S. LOWS LOWER 60S NW TO UPPER 60S SE.

WEDNESDAY THROUGH FRIDAY SHOULD REMAIN QUIET AS SURFACE HIGH
PRESSURE OVER THE OHIO VALLEY KEEPS THE COLD FRONT EAST OF THE AREA.
A SUPPORTING MIGRATORY HIGH DROPPING SOUTHEASTWARD OUT OF THE
NORTHERN PLAINS WILL HELP TO PROPEL A SECONDARY COLD FRONT THROUGH
THE REGION THAT WILL REINFORCE DRY CONDITIONS THROUGH AT LEAST
FRIDAY MORNING. MOISTURE SLOWLY INCREASES FRIDAY AFTERNOON AND
EASTERLY FLOW OFF THE ATLANTIC COULD HELP AID SOME DIURNAL
CONVECTION FRIDAY AFTERNOON...PRIMARILY FOCUSED ON THE SEA BREEZE.
SATURDAY WILL FEATURE INCREASED MOISTURE WITH A GREATER CHANCE FOR
DIURNAL CONVECTION. HIGHS DURING THIS PERIOD WILL BE LOW TO MID 80S
WITH LOWS IN THE LOWER TO MID 60S.


&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 115 PM SATURDAY...

24-HR TAF PERIOD:
VFR CONDITIONS WILL LARGELY PREVAIL THROUGH MIDNIGHT WITH CEILINGS
RANGING FROM 3000-5000 FT AGL...THOUGH IT IS POSSIBLE THAT THE
INT/GSO TERMINALS COULD SEE SUB-VFR CONDITIONS IN ASSOCIATION WITH
ISOLD SHOWERS AND THUNDERSTORMS...PRIMARILY BETWEEN 20-03Z.
SOUTHWEST WINDS AT 5-10 KT WILL WEAKEN TO 5 KT OR LESS OVERNIGHT. A
PERIOD OF SUB-VFR FOG OR CEILINGS WILL BE POSSIBLE EARLY SUNDAY
MORNING IN ASSOCIATION WITH LOW-LEVEL WARM ADVECTION...PRIMARILY
BETWEEN 08-13Z. AT THIS TIME...WILL ACCOUNT FOR THE FOG/STRATUS
POTENTIAL BY ADDING A TEMPO GROUP /5SM BR BKN010/ FOR 08-12Z AT ALL
TERMINALS. EXPECT SOUTHWEST WINDS INCREASING TO ~10 KT BY MID/LATE
SUNDAY MORNING WITH A SOMEWHAT BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS AT ALL TERMINALS SUNDAY AFTERNOON AND EVENING.

LOOKING AHEAD:
THE PROBABILITY FOR SHOWERS AND THUNDERSTORMS WILL FURTHER INCREASE
MON/MON NIGHT AT ALL TERMINALS...IN ASSOCIATION WITH STRENGTHENING
CYCLONIC FLOW ALOFT AND A COLD FRONT APPROACHING THE REGION FROM THE
NORTHWEST. THE FRONT IS EXPECTED TO PROGRESS SOUTHEAST ACROSS
CENTRAL NC DURING THE DAY TUE...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS SHIFTING TO THE EASTERN TERMINALS (RDU/FAY/RWI) BY TUE
AFTERNOON. ASIDE FROM A CHANCE FOR FOG NEAR AND JUST PRIOR TO
SUNRISE (08-12Z) WED/THU...EXPECT VFR CONDITIONS IN THE WAKE OF THE
FRONT AS HIGH PRESSURE BUILDS INTO THE REGION. -VINCENT

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...ELLIS
AVIATION...VINCENT










AREA FORECAST DISCUSSION

NWS RALEIGH NC

 210 PM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM AND MOIST SOUTHERLY FLOW WILL PREVAIL THROUGH THE REST OF THE
WEEKEND. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST ON
MONDAY...THEN PUSH SLOWLY EAST THROUGH THE CAROLINAS ON TUESDAY. IN
THE WAKE OF THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION ON
WEDNESDAY AND LINGER THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM SATURDAY...

OVERVIEW:
LIGHT NW FLOW ALOFT WILL PREVAIL ACROSS THE REGION THROUGH
TONIGHT...IN A WEAKNESS BETWEEN AN UPSTREAM RIDGE OVER THE SOUTHERN
PLAINS/ROCKIES AND A DOWNSTREAM RIDGE OFFSHORE THE SOUTHEAST COAST.
17Z WV IMAGERY AND RAP DATA INDICATED SMALL AMPLITUDE DISTURBANCES
UPSTREAM ACROSS OH/KY/WV...TRACKING SOUTHEAST TOWARD THE MID-
ATLANTIC AND NORTHERN PORTIONS OF NC.

PRECIPITATION CHANCES:
THE LOW-LEVEL RIDGE EXTENDING WESTWARD INTO CENTRAL NC THIS MORNING
HAS FURTHER WEAKENED...GIVING WAY TO AN INCREASINGLY MOIST SOUTHERLY
RETURN FLOW FROM THE SFC-925 MB...WITH ADDITIONAL MOISTURE ADVECTING
INTO THE AREA FROM THE WEST/WNW AT H85. SEASONABLY STRONG INSOLATION
WILL RESULT IN MARGINAL TO MODERATE DIURNAL DESTABILIZATION BY PEAK
HEATING WITH MLCAPE VALUES RANGING FROM 1500-2000 J/KG IN THE
WESTERN PIEDMONT TO 500-1000 J/KG IN THE EAST WHERE THE LOW-LEVELS
ARE DRIER AS NOTED ABOVE. THE PRIMARY UNCERTAINTY W/REGARD TO
CONVECTION WILL BE FORCING. VERY LITTLE IF ANY LOW-LEVEL FORCING
WILL BE PRESENT THIS AFT/EVE WITH LARGELY UNIDIRECTIONAL SFC-925 MB
FLOW OVER CENTRAL NC. ADDITIONALLY...UPPER LEVEL FORCING /DPVA/ IS
EXPECTED TO REMAIN N/NW OF CENTRAL NC THIS AFT/EVE AS SMALL
AMPLITUDE DISTURBANCES TRACK SLOWLY E/ESE FROM THE OH VALLEY INTO
THE WV AND CENTRAL/WESTERN VA. AN MCV AND A ROBUST COLD POOL ASSOC/W
AN ONGOING MCS UPSTREAM OVER EASTERN KY AND SOUTHWEST VA AT 17Z IS
LIKELY TO TRACK SOUTHEASTWARD TOWARD NORTHWEST NC AND MAY PROVIDE
SUFFICIENT FORCING FOR CONVECTION TO DEVELOP IN THE NW PIEDMONT LATE
THIS AFT/EVE (22-04Z). WITH THE ABOVE IN MIND...WILL INDICATE PRECIP
CHANCES OF 20-30% WEST OF THE HWY 1 CORRIDOR WITH THE RELATIVE BEST
CHANCE IN THE TRIAD. EAST OF HWY 1...GIVEN A PROFOUND LACK OF
FORCING AND A DRIER LOW-LEVEL AIRMASS /MARGINAL DESTABILIZATION/...
WILL KEEP THE FCST DRY. CHANCES FOR CONVECTION WILL DECREASE BY
MIDNIGHT IN ASSOC/W INCREASING NOCTURNAL STABILIZATION...THOUGH IF
SMALL AMPLITUDE DISTURBANCES AND/OR THE AFOREMENTIONED MCV GRAZE OR
TRACK ACROSS NORTHERN PORTIONS OF CENTRAL NC THERE MAY BE SUFFICIENT
MOISTURE/INSTABILITY TO SUPPORT ISOLD CONVECTION OVERNIGHT...AND
THIS WILL BE THE BASIS FOR A 20% CHANCE OF SHOWERS NORTH OF HWY 64
AFTER MIDNIGHT.

TEMPERATURES:
EXPECT HIGHS TODAY SLIGHTLY ABOVE NORMAL...IN THE MID/UPPER 80S TO
NEAR 90F. LOWS TONIGHT A FEW DEGREES ABOVE NORMAL DUE TO INCREASING
LOW-LEVEL MOISTURE AND PERHAPS MID/UPPER LEVEL CLOUD COVER...IN THE
UPPER 60S TO NEAR 70F.

SEVERE POTENTIAL:
A VERY SMALL (ALBEIT CONDITIONAL) THREAT OF AN ISOLD SEVERE
DOWNBURST EXISTS IN THE FAR W/NW PIEDMONT LATE THIS AFT/EVE WHERE
MODERATE INSTABILITY (1500-2000 J/KG) AND MODERATE DCAPE (1000 J/KG)
ARE PRESENT IN ADVANCE OF THE MCS /COLD POOL/ APPROACHING THE
NORTHWEST NC MOUNTAINS. CONFIDENCE IS LOW WITH REGARD TO HOW THE
AFOREMENTIONED COLD POOL WILL EVOLVE AND WHETHER OR NOT IT WILL
AFFECT THE NW PIEDMONT IN VICINITY OF PEAK HEATING...AND HAVE OPTED
TO LEAVE OUT ANY MENTION OF SVR WX IN THE HWO. -VINCENT

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 215 PM SATURDAY...

CYCLONIC FLOW ALOFT WILL STRENGTHEN ACROSS THE EASTERN CONUS AS
POTENT SHORTWAVE ENERGY TRACKING FROM SOUTHERN CANADA INTO THE UPPER
MIDWEST THIS AFTERNOON DIGS SOUTHEAST INTO THE UPPER GREAT LAKES ON
SUNDAY. AS A RESULT...A MOIST SOUTHWESTERLY LOW-LEVEL FLOW WILL
STRENGTHEN OVER THE CAROLINAS ON SUNDAY...WITH PWAT VALUES
INCREASING TO ABOVE NORMAL IN THE 1.75-2.00" RANGE AND DIURNAL
DESTABILIZATION YIELDING MARGINAL TO MODERATE INSTABILITY (1000-2000
J/KG MLCAPE) DURING PEAK HEATING. LOW-LEVEL FORCING ON SUNDAY WILL
BE ANEMIC ONCE AGAIN WITH LARGELY UNIDIRECTIONAL LOW-LEVEL FLOW...
THOUGH WITH STRONGER CYCLONIC FLOW ALOFT AND DEEPER MOISTURE ONE
WOULD EXPECT PRECIP CHANCES HIGHER THAN TODAY. ULTIMATELY...PRECIP
CHANCES WILL LIKELY DEPEND ON UPSTREAM DEVELOPMENT ACROSS THE HIGHER
TERRAIN IN WESTERN NC AND/OR THE TIMING OF SMALL AMPLITUDE
DISTURBANCES EMBEDDED IN CYCLONIC FLOW ALOFT. WILL INDICATE A 30-40%
CHANCE OF SHOWERS/STORMS SUNDAY AFT/EVE...HIGHEST IN NORTHERN
PORTIONS OF THE AREA...WITH A SLIGHT CHANCE OF SHOWERS PERSISTING
AFTER MIDNIGHT GIVEN CYCLONIC FLOW ALOFT AND DEEP MOISTURE IN THE
PRESENCE OF MARGINAL INSTABILITY. HIGHS ON SUN SIMILAR TO TODAY...
PERHAPS SLIGHTLY WARMER IF CLOUD COVER IS NOT PERVASIVE DURING THE
AFTERNOON...IN THE UPPER 80S TO NEAR 90F...WARMEST IN THE SANDHILLS
AND COASTAL PLAIN. LOWS SUN NIGHT A FEW DEGREES ABOVE NORMAL DUE TO
CLOUD COVER AND DEEP MOISTURE...IN THE LOWER 70S. -VINCENT

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

THE LONG TERM PERIOD OF THE FORECAST FEATURES A PERSISTENT RIDGE OF
HIGH PRESSURE ACROSS THE SOUTHERN ROCKIES AND AN EASTERN U.S. TROUGH
THAT INITIALLY AMPLIFIES EARLY IN THE WORK WEEK AND THEN DEAMPLIFIES
TOWARD THE END OF THE PERIOD.

ON MONDAY A COUPLE OF SHORT WAVE TROUGHS IN SERIES OF DISTURBANCES
MOVING THROUGH THE DEEPENING EASTERN U.S. TROUGH WILL MOVE ACROSS
THE REGION. THE AIR MASS ACROSS CENTRAL NC WILL BE MOIST WITH
PRECIPITABLE WATER VALUES JUST UNDER 2.0 INCHES. THE AIRMASS WILL
ALSO BE WEAKLY TO MODERATELY UNSTABLE. THIS SHOULD SUPPORT FAIRLY
GOOD CHANCES AND COVERAGE OF PRECIPITATION ON MONDAY AND MONDAY
NIGHT. WHILE CONVECTIVE ORGANIZATION IS LIKELY TO BE LIMITED GIVEN
BULK SHEAR VALUES IN THE 15-20KT RANGE...WEAK TO MODERATE
INSTABILITY AND WEAK FLOW WILL SUPPORT THE POTENTIAL FOR SLOW
MOVING THUNDERSTORMS WITH HEAVY RAIN AND POTENTIALLY GUSTY WINDS.
NAM/GFS GUIDANCE DIFFER ON MONDAY MAX TEMPERATURES BY 3-4 DEGREES IN
MOST LOCATIONS WITH THE GFS WARMER THAN THE NAM WHICH IS NOT
SURPRISING AS THE GFS LOW LEVEL THICKNESS VALUES ON MONDAY THAT ARE
10-15M LARGER. NOT READY TO JUMP ON THE LIKELY OVERDONE TEMPS FROM
THE GFS GIVEN CLOUDINESS AND POTENTIAL FOR PRECIPITATION AND WILL
FORECAST HIGHS IN THE 88-92 RANGE. IT WILL BE WARM AND MUGGY MONDAY
NIGHT WITH LOWS ONLY IN THE 69-73 RANGE.

ANOTHER SHORT WAVE TROUGH...THIS WAS ASSOCIATED WITH THE SURFACE
COLD FRONT WILL MOVE ACROSS OUR REGION TUESDAY AFTERNOON AND
EVENING. GUIDANCE IS BEGINNING TO SHOW A WEAK SURFACE WAVE MAY
DEVELOP ACROSS CENTRAL NC ON THE FRONT TUESDAY AFTERNOON AND
EVENING. EXPECT FAIRLY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS ON
TUESDAY WITH THE BEST COVERAGE EXPECTED ACROSS THE EASTERN PIEDMONT
AND COASTAL PLAIN AHEAD OF THE SURFACE WAVE AND IN A REGION OF
GREATER INSTABILITY. IT WILL BE A LITTLE COOLER ON TUESDAY WITH
HIGHS RANGING FROM THE MID 80S ACROSS THE WESTERN PIEDMONT TO THE
UPPER 80S ACROSS THE COASTAL PLAIN. LOWS TUESDAY NIGHT WILL RANGE
FROM THE LOW 60S ACROSS THE NORTHWEST PIEDMONT TO THE UPPER 60S IN
THE SOUTHERN COASTAL PLAIN.

THE FRONT WILL CONTINUE TO SHIFT SOUTH OF CENTRAL NC ON WEDNESDAY
BUT A FEW SHOWERS MAY LINGER INTO EARLY WEDNESDAY ACROSS THE
SOUTHERN COASTAL PLAIN AND SANDHILLS. OTHERWISE HIGH PRESSURE WILL
BUILD INTO THE REGION ON WEDNESDAY AND THURSDAY WITH GENERALLY FAIR
WEATHER AND SEASONABLE TEMPERATURES. A COLD FRONT WILL PUSH SOUTH
ACROSS THE MID ATLANTIC LATE THURSDAY AND EARLY FRIDAY BRINGING
ADDITIONAL CLOUDINESS AND EVEN COOLER TEMPERATURES. PRECIPITATION
CHANCES APPEAR LIMITED ACROSS CENTRAL NC WITH THIS FEATURE. HIGH
TEMPERATURES WILL RANGE IN THE LOWER TO MID 80S WITH FRIDAY BEING
THE COOLEST DAY. MORNING LOWS SHOULD RANGE IN THE LOWER TO MID 60S.
-BLAES

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 115 PM SATURDAY...

24-HR TAF PERIOD:
VFR CONDITIONS WILL LARGELY PREVAIL THROUGH MIDNIGHT WITH CEILINGS
RANGING FROM 3000-5000 FT AGL...THOUGH IT IS POSSIBLE THAT THE
INT/GSO TERMINALS COULD SEE SUB-VFR CONDITIONS IN ASSOCIATION WITH
ISOLD SHOWERS AND THUNDERSTORMS...PRIMARILY BETWEEN 20-03Z.
SOUTHWEST WINDS AT 5-10 KT WILL WEAKEN TO 5 KT OR LESS OVERNIGHT. A
PERIOD OF SUB-VFR FOG OR CEILINGS WILL BE POSSIBLE EARLY SUNDAY
MORNING IN ASSOCIATION WITH LOW-LEVEL WARM ADVECTION...PRIMARILY
BETWEEN 08-13Z. AT THIS TIME...WILL ACCOUNT FOR THE FOG/STRATUS
POTENTIAL BY ADDING A TEMPO GROUP /5SM BR BKN010/ FOR 08-12Z AT ALL
TERMINALS. EXPECT SOUTHWEST WINDS INCREASING TO ~10 KT BY MID/LATE
SUNDAY MORNING WITH A SOMEWHAT BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS AT ALL TERMINALS SUNDAY AFTERNOON AND EVENING.

LOOKING AHEAD:
THE PROBABILITY FOR SHOWERS AND THUNDERSTORMS WILL FURTHER INCREASE
MON/MON NIGHT AT ALL TERMINALS...IN ASSOCIATION WITH STRENGTHENING
CYCLONIC FLOW ALOFT AND A COLD FRONT APPROACHING THE REGION FROM THE
NORTHWEST. THE FRONT IS EXPECTED TO PROGRESS SOUTHEAST ACROSS
CENTRAL NC DURING THE DAY TUE...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS SHIFTING TO THE EASTERN TERMINALS (RDU/FAY/RWI) BY TUE
AFTERNOON. ASIDE FROM A CHANCE FOR FOG NEAR AND JUST PRIOR TO
SUNRISE (08-12Z) WED/THU...EXPECT VFR CONDITIONS IN THE WAKE OF THE
FRONT AS HIGH PRESSURE BUILDS INTO THE REGION. -VINCENT

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...BLAES
AVIATION...VINCENT







AREA FORECAST DISCUSSION

NWS RALEIGH NC

 156 PM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM AND MOIST SOUTHERLY FLOW WILL PREVAIL THROUGH THE REST OF THE
WEEKEND. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST ON
MONDAY...THEN PUSH SLOWLY EAST THROUGH THE CAROLINAS ON TUESDAY. IN
THE WAKE OF THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION ON
WEDNESDAY AND LINGER THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 200 PM SATURDAY...

OVERVIEW:
LIGHT NW FLOW ALOFT WILL PREVAIL ACROSS THE REGION THROUGH
TONIGHT...IN A WEAKNESS BETWEEN AN UPSTREAM RIDGE OVER THE SOUTHERN
PLAINS/ROCKIES AND A DOWNSTREAM RIDGE OFFSHORE THE SOUTHEAST COAST.
17Z WV IMAGERY AND RAP DATA INDICATED SMALL AMPLITUDE DISTURBANCES
UPSTREAM ACROSS OH/KY/WV...TRACKING SOUTHEAST TOWARD THE MID-
ATLANTIC AND NORTHERN PORTIONS OF NC.

PRECIPITATION CHANCES:
THE LOW-LEVEL RIDGE EXTENDING WESTWARD INTO CENTRAL NC THIS MORNING
HAS FURTHER WEAKENED...GIVING WAY TO AN INCREASINGLY MOIST SOUTHERLY
RETURN FLOW FROM THE SFC-925 MB...WITH ADDITIONAL MOISTURE ADVECTING
INTO THE AREA FROM THE WEST/WNW AT H85. SEASONABLY STRONG INSOLATION
WILL RESULT IN MARGINAL TO MODERATE DIURNAL DESTABILIZATION BY PEAK
HEATING WITH MLCAPE VALUES RANGING FROM 1500-2000 J/KG IN THE
WESTERN PIEDMONT TO 500-1000 J/KG IN THE EAST WHERE THE LOW-LEVELS
ARE DRIER AS NOTED ABOVE. THE PRIMARY UNCERTAINTY W/REGARD TO
CONVECTION WILL BE FORCING. VERY LITTLE IF ANY LOW-LEVEL FORCING
WILL BE PRESENT THIS AFT/EVE WITH LARGELY UNIDIRECTIONAL SFC-925 MB
FLOW OVER CENTRAL NC. ADDITIONALLY...UPPER LEVEL FORCING /DPVA/ IS
EXPECTED TO REMAIN N/NW OF CENTRAL NC THIS AFT/EVE AS SMALL
AMPLITUDE DISTURBANCES TRACK SLOWLY E/ESE FROM THE OH VALLEY INTO
THE WV AND CENTRAL/WESTERN VA. AN MCV AND A ROBUST COLD POOL ASSOC/W
AN ONGOING MCS UPSTREAM OVER EASTERN KY AND SOUTHWEST VA AT 17Z IS
LIKELY TO TRACK SOUTHEASTWARD TOWARD NORTHWEST NC AND MAY PROVIDE
SUFFICIENT FORCING FOR CONVECTION TO DEVELOP IN THE NW PIEDMONT LATE
THIS AFT/EVE (22-04Z). WITH THE ABOVE IN MIND...WILL INDICATE PRECIP
CHANCES OF 20-30% WEST OF THE HWY 1 CORRIDOR WITH THE RELATIVE BEST
CHANCE IN THE TRIAD. EAST OF HWY 1...GIVEN A PROFOUND LACK OF
FORCING AND A DRIER LOW-LEVEL AIRMASS /MARGINAL DESTABILIZATION/...
WILL KEEP THE FCST DRY. CHANCES FOR CONVECTION WILL DECREASE BY
MIDNIGHT IN ASSOC/W INCREASING NOCTURNAL STABILIZATION...THOUGH IF
SMALL AMPLITUDE DISTURBANCES AND/OR THE AFOREMENTIONED MCV GRAZE OR
TRACK ACROSS NORTHERN PORTIONS OF CENTRAL NC THERE MAY BE SUFFICIENT
MOISTURE/INSTABILITY TO SUPPORT ISOLD CONVECTION OVERNIGHT...AND
THIS WILL BE THE BASIS FOR A 20% CHANCE OF SHOWERS NORTH OF HWY 64
AFTER MIDNIGHT.

TEMPERATURES:
EXPECT HIGHS TODAY SLIGHTLY ABOVE NORMAL...IN THE MID/UPPER 80S TO
NEAR 90F. LOWS TONIGHT A FEW DEGREES ABOVE NORMAL DUE TO INCREASING
LOW-LEVEL MOISTURE AND PERHAPS MID/UPPER LEVEL CLOUD COVER...IN THE
UPPER 60S TO NEAR 70F.

SEVERE POTENTIAL:
A VERY SMALL (ALBEIT CONDITIONAL) THREAT OF AN ISOLD SEVERE
DOWNBURST EXISTS IN THE FAR W/NW PIEDMONT LATE THIS AFT/EVE WHERE
MODERATE INSTABILITY (1500-2000 J/KG) AND MODERATE DCAPE (1000 J/KG)
ARE PRESENT IN ADVANCE OF THE MCS /COLD POOL/ APPROACHING THE
NORTHWEST NC MOUNTAINS. CONFIDENCE IS LOW WITH REGARD TO HOW THE
AFOREMENTIONED COLD POOL WILL EVOLVE AND WHETHER OR NOT IT WILL
AFFECT THE NW PIEDMONT IN VICINITY OF PEAK HEATING...AND HAVE OPTED
TO LEAVE OUT ANY MENTION OF SVR WX IN THE HWO. -VINCENT

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 305 AM SATURDAY...

SHOWER/STORM CHANCES AND COVERAGE APPEAR TO RISE FOR SUNDAY/SUNDAY
NIGHT... AS ENERGY FROM CONVECTION NOW OVER THE MIDWEST ALONG WITH A
STRONGER WAVE DROPPING THROUGH SW/S-CENTRAL CANADA THIS MORNING
HELPS TO SUBSTANTIALLY DEEPEN THE EASTERN CONUS MEAN TROUGH. DEEP
MOISTURE PERSISTS OVER CENTRAL NC WITH PREDICTED PW VALUES NEAR 2.0
INCHES... WELL ABOVE NORMAL... WITH STRENGTHENING LOW LEVEL MOISTURE
TRANSPORT. MODELS INDICATE INCREASING ASCENT AND MOISTURE FLUX
THROUGH THE COLUMN... AND IMPROVING INSTABILITY (MLCAPE OF 1000-2000
J/KG AREA WIDE WITH N-CAPE NEAR 0.15) WITH AT LEAST WEAK DPVA AND
INCREASINGLY CYCLONIC FLOW ALOFT DOES SUPPORT SCATTERED SHOWERS AND
STORMS OVER ALL OF CENTRAL NC. DEEP LAYER SHEAR REMAINS POOR AT 15
KTS OR LESS... SO DO NOT EXPECT A LOT OF STRONG AND/OR ORGANIZED
CONVECTION... BUT COVERAGE SHOULD BE A BIT BETTER IN THE NW WHERE
THE BULK SHEAR WILL BE MAXIMIZED. HIGHS 86-91. LOWS 68-72 WITH
GRADUALLY DECREASING SHOWER/STORM CHANCES WITH LOSS OF HEATING. -GIH

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

THE LONG TERM PERIOD OF THE FORECAST FEATURES A PERSISTENT RIDGE OF
HIGH PRESSURE ACROSS THE SOUTHERN ROCKIES AND AN EASTERN U.S. TROUGH
THAT INITIALLY AMPLIFIES EARLY IN THE WORK WEEK AND THEN DEAMPLIFIES
TOWARD THE END OF THE PERIOD.

ON MONDAY A COUPLE OF SHORT WAVE TROUGHS IN SERIES OF DISTURBANCES
MOVING THROUGH THE DEEPENING EASTERN U.S. TROUGH WILL MOVE ACROSS
THE REGION. THE AIR MASS ACROSS CENTRAL NC WILL BE MOIST WITH
PRECIPITABLE WATER VALUES JUST UNDER 2.0 INCHES. THE AIRMASS WILL
ALSO BE WEAKLY TO MODERATELY UNSTABLE. THIS SHOULD SUPPORT FAIRLY
GOOD CHANCES AND COVERAGE OF PRECIPITATION ON MONDAY AND MONDAY
NIGHT. WHILE CONVECTIVE ORGANIZATION IS LIKELY TO BE LIMITED GIVEN
BULK SHEAR VALUES IN THE 15-20KT RANGE...WEAK TO MODERATE
INSTABILITY AND WEAK FLOW WILL SUPPORT THE POTENTIAL FOR SLOW
MOVING THUNDERSTORMS WITH HEAVY RAIN AND POTENTIALLY GUSTY WINDS.
NAM/GFS GUIDANCE DIFFER ON MONDAY MAX TEMPERATURES BY 3-4 DEGREES IN
MOST LOCATIONS WITH THE GFS WARMER THAN THE NAM WHICH IS NOT
SURPRISING AS THE GFS LOW LEVEL THICKNESS VALUES ON MONDAY THAT ARE
10-15M LARGER. NOT READY TO JUMP ON THE LIKELY OVERDONE TEMPS FROM
THE GFS GIVEN CLOUDINESS AND POTENTIAL FOR PRECIPITATION AND WILL
FORECAST HIGHS IN THE 88-92 RANGE. IT WILL BE WARM AND MUGGY MONDAY
NIGHT WITH LOWS ONLY IN THE 69-73 RANGE.

ANOTHER SHORT WAVE TROUGH...THIS WAS ASSOCIATED WITH THE SURFACE
COLD FRONT WILL MOVE ACROSS OUR REGION TUESDAY AFTERNOON AND
EVENING. GUIDANCE IS BEGINNING TO SHOW A WEAK SURFACE WAVE MAY
DEVELOP ACROSS CENTRAL NC ON THE FRONT TUESDAY AFTERNOON AND
EVENING. EXPECT FAIRLY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS ON
TUESDAY WITH THE BEST COVERAGE EXPECTED ACROSS THE EASTERN PIEDMONT
AND COASTAL PLAIN AHEAD OF THE SURFACE WAVE AND IN A REGION OF
GREATER INSTABILITY. IT WILL BE A LITTLE COOLER ON TUESDAY WITH
HIGHS RANGING FROM THE MID 80S ACROSS THE WESTERN PIEDMONT TO THE
UPPER 80S ACROSS THE COASTAL PLAIN. LOWS TUESDAY NIGHT WILL RANGE
FROM THE LOW 60S ACROSS THE NORTHWEST PIEDMONT TO THE UPPER 60S IN
THE SOUTHERN COASTAL PLAIN.

THE FRONT WILL CONTINUE TO SHIFT SOUTH OF CENTRAL NC ON WEDNESDAY
BUT A FEW SHOWERS MAY LINGER INTO EARLY WEDNESDAY ACROSS THE
SOUTHERN COASTAL PLAIN AND SANDHILLS. OTHERWISE HIGH PRESSURE WILL
BUILD INTO THE REGION ON WEDNESDAY AND THURSDAY WITH GENERALLY FAIR
WEATHER AND SEASONABLE TEMPERATURES. A COLD FRONT WILL PUSH SOUTH
ACROSS THE MID ATLANTIC LATE THURSDAY AND EARLY FRIDAY BRINGING
ADDITIONAL CLOUDINESS AND EVEN COOLER TEMPERATURES. PRECIPITATION
CHANCES APPEAR LIMITED ACROSS CENTRAL NC WITH THIS FEATURE. HIGH
TEMPERATURES WILL RANGE IN THE LOWER TO MID 80S WITH FRIDAY BEING
THE COOLEST DAY. MORNING LOWS SHOULD RANGE IN THE LOWER TO MID 60S.
-BLAES

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 115 PM SATURDAY...

24-HR TAF PERIOD:
VFR CONDITIONS WILL LARGELY PREVAIL THROUGH MIDNIGHT WITH CEILINGS
RANGING FROM 3000-5000 FT AGL...THOUGH IT IS POSSIBLE THAT THE
INT/GSO TERMINALS COULD SEE SUB-VFR CONDITIONS IN ASSOCIATION WITH
ISOLD SHOWERS AND THUNDERSTORMS...PRIMARILY BETWEEN 20-03Z.
SOUTHWEST WINDS AT 5-10 KT WILL WEAKEN TO 5 KT OR LESS OVERNIGHT. A
PERIOD OF SUB-VFR FOG OR CEILINGS WILL BE POSSIBLE EARLY SUNDAY
MORNING IN ASSOCIATION WITH LOW-LEVEL WARM ADVECTION...PRIMARILY
BETWEEN 08-13Z. AT THIS TIME...WILL ACCOUNT FOR THE FOG/STRATUS
POTENTIAL BY ADDING A TEMPO GROUP /5SM BR BKN010/ FOR 08-12Z AT ALL
TERMINALS. EXPECT SOUTHWEST WINDS INCREASING TO ~10 KT BY MID/LATE
SUNDAY MORNING WITH A SOMEWHAT BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS AT ALL TERMINALS SUNDAY AFTERNOON AND EVENING.

LOOKING AHEAD:
THE PROBABILITY FOR SHOWERS AND THUNDERSTORMS WILL FURTHER INCREASE
MON/MON NIGHT AT ALL TERMINALS...IN ASSOCIATION WITH STRENGTHENING
CYCLONIC FLOW ALOFT AND A COLD FRONT APPROACHING THE REGION FROM THE
NORTHWEST. THE FRONT IS EXPECTED TO PROGRESS SOUTHEAST ACROSS
CENTRAL NC DURING THE DAY TUE...WITH THE BEST CHANCE OF SHOWERS AND
THUNDERSTORMS SHIFTING TO THE EASTERN TERMINALS (RDU/FAY/RWI) BY TUE
AFTERNOON. ASIDE FROM A CHANCE FOR FOG NEAR AND JUST PRIOR TO
SUNRISE (08-12Z) WED/THU...EXPECT VFR CONDITIONS IN THE WAKE OF THE
FRONT AS HIGH PRESSURE BUILDS INTO THE REGION. -VINCENT

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...HARTFIELD
LONG TERM...BLAES
AVIATION...VINCENT






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 305 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM MOIST SOUTHERLY FLOW WILL PERSIST THROUGH THE WEEKEND. A SLOW
MOVING COLD FRONT WILL APPROACH THE REGION ON MONDAY AND THEN PUSH
THROUGH THE AREA ON TUESDAY. HIGH PRESSURE WILL MOVE INTO THE REGION
ON WEDNESDAY AND LINGER ON THURSDAY. ANOTHER COLD FRONT WILL CROSS
THE REGION ON FRIDAY.

&&

.NEAR TERM /TODAY AND TONIGHT/...
AS OF 250 AM SATURDAY...

STILL LOOKS LIKE A FEW SHOWERS/STORMS OVER THE WRN/SRN PORTIONS OF
THE FORECAST AREA LATE TODAY... WHILE ERN SECTIONS SHOULD REMAIN
DRY. LATEST SURFACE MAP SHOWS THE WEAK OFFSHORE-CENTERED SURFACE
HIGH EXTENDING WESTWARD OVER NC... WHILE A COLD FRONT SITS WELL TO
OUR NW ACROSS THE LOWER GREAT LAKES. A PROMINENT BUT WEAKENING MID
LEVEL SHORTWAVE HAS DROPPED SE OVER THE ST LAWRENCE VALLEY/SRN MI
OVER THE LAST FEW HOURS AND SHOULD CONTINUE TO TRACK SE TOWARD THE
OH VALLEY AND CENTRAL APPALACHIANS THIS MORNING... BEFORE SHIFTING
EASTWARD ACROSS THE MIDATLANTIC REGION LATER TODAY AND TONIGHT. MID
LEVEL FLOW GETS MUCH WEAKER AS FAR SOUTH AS NC AND MUCH OF THE
BETTER DPVA SHIFTS BY WELL TO OUR NORTH... BUT THE APPROACH OF ANY
RESIDUAL OUTFLOW EMANATING FROM THE OH VALLEY CONVECTION WILL BE
MOVING INTO WRN NC LATE TODAY INTO AN AREA OF MODERATE INSTABILITY
(FORECAST MLCAPE OVER FAR WRN PIEDMONT OF 1000-1500 J/KG)... WHILE
NEAR-NORMAL PW VALUES INCREASE QUICKLY TODAY TO 1.8-2.0 INCHES...
WITH GOOD HEATING EXPECTED AND INCREASING 850 MB THETA-E OVER WRN
NC. WHILE THE ERN CWA SHOULD REMAIN FAIRLY STABLE TODAY WITH A LATER
INCREASE IN MOISTURE... MODEL OUTPUT (INCLUDING CONVECTION-ALLOWING
MODELS) AND EXTRAPOLATION OF UPSTREAM FEATURES WOULD CERTAINLY
SUPPORT 20-40% COVERAGE OF STORMS LATE TODAY THROUGH MID EVENING
OVER THE WRN/SRN PIEDMONT MAINLY WEST OF THE TRIANGLE. WEAK ELEVATED
INSTABILITY AROUND 500-600 J/KG PERSISTS OVER THE PIEDMONT
OVERNIGHT... WHICH IN CONJUNCTION WITH THE ABOVE-NORMAL PW VALUES
WARRANTS A MENTION OF ISOLATED SHOWERS LINGERING OVERNIGHT. DEEP
LAYER SHEAR REMAINS QUITE WEAK AND FORECAST SOUNDINGS DO NOT SUGGEST
A DOWNBURST WIND POTENTIAL... SO DO NOT EXPECT ANY STRONG OR SEVERE
STORMS. HIGHS 85-90 AND LOWS 67-71. -GIH

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 305 AM SATURDAY...

SHOWER/STORM CHANCES AND COVERAGE APPEAR TO RISE FOR SUNDAY/SUNDAY
NIGHT... AS ENERGY FROM CONVECTION NOW OVER THE MIDWEST ALONG WITH A
STRONGER WAVE DROPPING THROUGH SW/S-CENTRAL CANADA THIS MORNING
HELPS TO SUBSTANTIALLY DEEPEN THE EASTERN CONUS MEAN TROUGH. DEEP
MOISTURE PERSISTS OVER CENTRAL NC WITH PREDICTED PW VALUES NEAR 2.0
INCHES... WELL ABOVE NORMAL... WITH STRENGTHENING LOW LEVEL MOISTURE
TRANSPORT. MODELS INDICATE INCREASING ASCENT AND MOISTURE FLUX
THROUGH THE COLUMN... AND IMPROVING INSTABILITY (MLCAPE OF 1000-2000
J/KG AREAWIDE WITH N-CAPE NEAR 0.15) WITH AT LEAST WEAK DPVA AND
INCREASINGLY CYCLONIC FLOW ALOFT DOES SUPPORT SCATTERED SHOWERS AND
STORMS OVER ALL OF CENTRAL NC. DEEP LAYER SHEAR REMAINS POOR AT 15
KTS OR LESS... SO DO NOT EXPECT A LOT OF STRONG AND/OR ORGANIZED
CONVECTION... BUT COVERAGE SHOULD BE A BIT BETTER IN THE NW WHERE
THE BULK SHEAR WILL BE MAXIMIZED. HIGHS 86-91. LOWS 68-72 WITH
GRADUALLY DECREASING SHOWER/STORM CHANCES WITH LOSS OF HEATING. -GIH

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

THE LONG TERM PERIOD OF THE FORECAST FEATURES A PERSISTENT RIDGE OF
HIGH PRESSURE ACROSS THE SOUTHERN ROCKIES AND AN EASTERN U.S. TROUGH
THAT INITIALLY AMPLIFIES EARLY IN THE WORK WEEK AND THEN DEAMPLIFIES
TOWARD THE END OF THE PERIOD.

ON MONDAY A COUPLE OF SHORT WAVE TROUGHS IN SERIES OF DISTURBANCES
MOVING THROUGH THE DEEPENING EASTERN U.S. TROUGH WILL MOVE ACROSS
THE REGION. THE AIR MASS ACROSS CENTRAL NC WILL BE MOIST WITH
PRECIPITABLE WATER VALUES JUST UNDER 2.0 INCHES. THE AIRMASS WILL
ALSO BE WEAKLY TO MODERATELY UNSTABLE. THIS SHOULD SUPPORT FAIRLY
GOOD CHANCES AND COVERAGE OF PRECIPITATION ON MONDAY AND MONDAY
NIGHT. WHILE CONVECTIVE ORGANIZATION IS LIKELY TO BE LIMITED GIVEN
BULK SHEAR VALUES IN THE 15-20KT RANGE...WEAK TO MODERATE
INSTABILITY AND WEAK FLOW WILL SUPPORT THE POTENTIAL FOR SLOW
MOVING THUNDERSTORMS WITH HEAVY RAIN AND POTENTIALLY GUSTY WINDS.
NAM/GFS GUIDANCE DIFFER ON MONDAY MAX TEMPERATURES BY 3-4 DEGREES IN
MOST LOCATIONS WITH THE GFS WARMER THAN THE NAM WHICH IS NOT
SURPRISING AS THE GFS LOW LEVEL THICKNESS VALUES ON MONDAY THAT ARE
10-15M LARGER. NOT READY TO JUMP ON THE LIKELY OVERDONE TEMPS FROM
THE GFS GIVEN CLOUDINESS AND POTENTIAL FOR PRECIPITATION AND WILL
FORECAST HIGHS IN THE 88-92 RANGE. IT WILL BE WARM AND MUGGY MONDAY
NIGHT WITH LOWS ONLY IN THE 69-73 RANGE.

ANOTHER SHORT WAVE TROUGH...THIS WAS ASSOCIATED WITH THE SURFACE
COLD FRONT WILL MOVE ACROSS OUR REGION TUESDAY AFTERNOON AND
EVENING. GUIDANCE IS BEGINNING TO SHOW A WEAK SURFACE WAVE MAY
DEVELOP ACROSS CENTRAL NC ON THE FRONT TUESDAY AFTERNOON AND
EVENING. EXPECT FAIRLY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS ON
TUESDAY WITH THE BEST COVERAGE EXPECTED ACROSS THE EASTERN PIEDMONT
AND COASTAL PLAIN AHEAD OF THE SURFACE WAVE AND IN A REGION OF
GREATER INSTABILITY. IT WILL BE A LITTLE COOLER ON TUESDAY WITH
HIGHS RANGING FROM THE MID 80S ACROSS THE WESTERN PIEDMONT TO THE
UPPER 80S ACROSS THE COASTAL PLAIN. LOWS TUESDAY NIGHT WILL RANGE
FROM THE LOW 60S ACROSS THE NORTHWEST PIEDMONT TO THE UPPER 60S IN
THE SOUTHERN COASTAL PLAIN.

THE FRONT WILL CONTINUE TO SHIFT SOUTH OF CENTRAL NC ON WEDNESDAY
BUT A FEW SHOWERS MAY LINGER INTO EARLY WEDNESDAY ACROSS THE
SOUTHERN COASTAL PLAIN AND SANDHILLS. OTHERWISE HIGH PRESSURE WILL
BUILD INTO THE REGION ON WEDNESDAY AND THURSDAY WITH GENERALLY FAIR
WEATHER AND SEASONABLE TEMPERATURES. A COLD FRONT WILL PUSH SOUTH
ACROSS THE MID ATLANTIC LATE THURSDAY AND EARLY FRIDAY BRINGING
ADDITIONAL CLOUDINESS AND EVEN COOLER TEMPERATURES. PRECIPITATION
CHANCES APPEAR LIMITED ACROSS CENTRAL NC WITH THIS FEATURE. HIGH
TEMPERATURES WILL RANGE IN THE LOWER TO MID 80S WITH FRIDAY BEING
THE COOLEST DAY. MORNING LOWS SHOULD RANGE IN THE LOWER TO MID 60S.
-BLAES
&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...

ADVERSE AVIATION CONDITIONS IN FOG ARE EXPECTED AT FAY/RWI AND
POTENTIALLY RDU EARLY THIS MORNING (INT/GSO SHOULD REMAIN MOSTLY
VFR). THE NARROW WEAK SURFACE RIDGE CONTINUES TO EXTEND FROM
OFFSHORE WESTWARD ACROSS NC... RESULTING IN VERY LIGHT MAINLY
SOUTHERLY BREEZE. WITH THE LACK OF HIGHER CLOUDS FACILITATING
RADIATIONAL COOLING AND LOW LEVEL DECOUPLING... WINDS SHOULD BECOME
CALM OR NEARLY CALM. THE HRRR (AMONG OTHER MODELS) FAVORS IFR FOG
FORMING NEAR FAY/RWI AFTER 09Z AND POTENTIALLY EXPANDING TOWARD RDU
AFTER 11Z. THIS AGREES WELL WITH STATISTICAL GUIDANCE AS WELL AS
PERSISTENCE. WILL FAVOR FOG OVER STRATUS AT RWI/FAY/RDU GIVEN THAT
WINDS HAVE ALREADY DIMINISHED OVER MUCH OF THE AREA. THESE IFR
CONDITIONS ARE EXPECTED TO MIX OUT TO VFR BY 13Z-14Z. VFR CONDITIONS
WILL THEN DOMINATE ALL SITES THROUGH THE END OF THE TAF VALID PERIOD
(06Z EARLY SUNDAY MORNING)... ALTHOUGH INT/GSO WILL SEE A RISK OF
SCATTERED STORMS PRODUCING BRIEF SUB-VFR CONDITIONS AND A FEW WIND
GUSTS BETWEEN 21Z AND 03Z THIS AFTERNOON/EVENING... AS AN UPPER
LEVEL DISTURBANCE APPROACHES FROM THE NW.

LOOKING BEYOND 06Z EARLY SUNDAY MORNING... THERE IS ANOTHER CHANCE
OF SHALLOW PATCHY FOG 09Z-13Z SUNDAY MORNING AS HUMIDITY STEADILY
INCREASES WITH LIGHT SW FLOW... BUT THE CHANCE IS LOWER THAN IN PAST
COUPLE OF DAYS AS WE`LL SEE MORE MID/HIGH CLOUDS ROLLING IN.
OTHERWISE... VFR CONDITIONS WILL PREVAIL THROUGH THIS PERIOD... BUT
BETTER SHOWER/STORM COVERAGE IS EXPECTED ACROSS CENTRAL NC SUNDAY
AND MONDAY AFTERNOONS/EARLY EVENING AS A LOW PRESSURE TROUGH ALOFT
STRENGTHENS OVER THE EASTERN U.S.  THESE STORMS MAY PRODUCE A PERIOD
OF SUB-VFR CONDITIONS AND GUSTY WINDS. STORM CHANCE COULD LINGER
INTO TUESDAY IN THE EAST... THEN COLD FRONT PASSAGE BY TUESDAY NIGHT
SHOULD BRING VFR CONDITIONS AND DRY WEATHER FOR WEDNESDAY. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BLAES
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...BLAES
AVIATION...HARTFIELD







AREA FORECAST DISCUSSION

NWS RALEIGH NC

 255 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM MOIST SOUTHERLY FLOW WILL PERSIST THROUGH THE WEEKEND. A SLOW
MOVING COLD FRONT WILL APPROACH THE REGION ON MONDAY AND THEN PUSH
THROUGH THE AREA ON TUESDAY. HIGH PRESSURE WILL MOVE INTO THE REGION
ON WEDNESDAY AND LINGER ON THURSDAY. ANOTHER COLD FRONT WILL CROSS
THE REGION ON FRIDAY.

&&

.NEAR TERM /TODAY AND TONIGHT/...
AS OF 250 AM SATURDAY...

STILL LOOKS LIKE A FEW SHOWERS/STORMS OVER THE WRN/SRN PORTIONS OF
THE FORECAST AREA LATE TODAY... WHILE ERN SECTIONS SHOULD REMAIN
DRY. LATEST SURFACE MAP SHOWS THE WEAK OFFSHORE-CENTERED SURFACE
HIGH EXTENDING WESTWARD OVER NC... WHILE A COLD FRONT SITS WELL TO
OUR NW ACROSS THE LOWER GREAT LAKES. A PROMINENT BUT WEAKENING MID
LEVEL SHORTWAVE HAS DROPPED SE OVER THE ST LAWRENCE VALLEY/SRN MI
OVER THE LAST FEW HOURS AND SHOULD CONTINUE TO TRACK SE TOWARD THE
OH VALLEY AND CENTRAL APPALACHIANS THIS MORNING... BEFORE SHIFTING
EASTWARD ACROSS THE MIDATLANTIC REGION LATER TODAY AND TONIGHT. MID
LEVEL FLOW GETS MUCH WEAKER AS FAR SOUTH AS NC AND MUCH OF THE
BETTER DPVA SHIFTS BY WELL TO OUR NORTH... BUT THE APPROACH OF ANY
RESIDUAL OUTFLOW EMANATING FROM THE OH VALLEY CONVECTION WILL BE
MOVING INTO WRN NC LATE TODAY INTO AN AREA OF MODERATE INSTABILITY
(FORECAST MLCAPE OVER FAR WRN PIEDMONT OF 1000-1500 J/KG)... WHILE
NEAR-NORMAL PW VALUES INCREASE QUICKLY TODAY TO 1.8-2.0 INCHES...
WITH GOOD HEATING EXPECTED AND INCREASING 850 MB THETA-E OVER WRN
NC. WHILE THE ERN CWA SHOULD REMAIN FAIRLY STABLE TODAY WITH A LATER
INCREASE IN MOISTURE... MODEL OUTPUT (INCLUDING CONVECTION-ALLOWING
MODELS) AND EXTRAPOLATION OF UPSTREAM FEATURES WOULD CERTAINLY
SUPPORT 20-40% COVERAGE OF STORMS LATE TODAY THROUGH MID EVENING
OVER THE WRN/SRN PIEDMONT MAINLY WEST OF THE TRIANGLE. WEAK ELEVATED
INSTABILITY AROUND 500-600 J/KG PERSISTS OVER THE PIEDMONT
OVERNIGHT... WHICH IN CONJUNCTION WITH THE ABOVE-NORMAL PW VALUES
WARRANTS A MENTION OF ISOLATED SHOWERS LINGERING OVERNIGHT. DEEP
LAYER SHEAR REMAINS QUITE WEAK AND FORECAST SOUNDINGS DO NOT SUGGEST
A DOWNBURST WIND POTENTIAL... SO DO NOT EXPECT ANY STRONG OR SEVERE
STORMS. HIGHS 85-90 AND LOWS 67-71. -GIH

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 315 PM FRIDAY...

TO BE UPDATED SHORTLY.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 255 AM SATURDAY...

THE LONG TERM PERIOD OF THE FORECAST FEATURES A PERSISTENT RIDGE OF
HIGH PRESSURE ACROSS THE SOUTHERN ROCKIES AND AN EASTERN U.S. TROUGH
THAT INITIALLY AMPLIFIES EARLY IN THE WORK WEEK AND THEN DEAMPLIFIES
TOWARD THE END OF THE PERIOD.

ON MONDAY A COUPLE OF SHORT WAVE TROUGHS IN SERIES OF DISTURBANCES
MOVING THROUGH THE DEEPENING EASTERN U.S. TROUGH WILL MOVE ACROSS
THE REGION. THE AIR MASS ACROSS CENTRAL NC WILL BE MOIST WITH
PRECIPITABLE WATER VALUES JUST UNDER 2.0 INCHES. THE AIRMASS WILL
ALSO BE WEAKLY TO MODERATELY UNSTABLE. THIS SHOULD SUPPORT FAIRLY
GOOD CHANCES AND COVERAGE OF PRECIPITATION ON MONDAY AND MONDAY
NIGHT. WHILE CONVECTIVE ORGANIZATION IS LIKELY TO BE LIMITED GIVEN
BULK SHEAR VALUES IN THE 15-20KT RANGE...WEAK TO MODERATE
INSTABILITY AND WEAK FLOW WILL SUPPORT THE POTENTIAL FOR SLOW
MOVING THUNDERSTORMS WITH HEAVY RAIN AND POTENTIALLY GUSTY WINDS.
NAM/GFS GUIDANCE DIFFER ON MONDAY MAX TEMPERATURES BY 3-4 DEGREES IN
MOST LOCATIONS WITH THE GFS WARMER THAN THE NAM WHICH IS NOT
SURPRISING AS THE GFS LOW LEVEL THICKNESS VALUES ON MONDAY THAT ARE
10-15M LARGER. NOT READY TO JUMP ON THE LIKELY OVERDONE TEMPS FROM
THE GFS GIVEN CLOUDINESS AND POTENTIAL FOR PRECIPITATION AND WILL
FORECAST HIGHS IN THE 88-92 RANGE. IT WILL BE WARM AND MUGGY MONDAY
NIGHT WITH LOWS ONLY IN THE 69-73 RANGE.

ANOTHER SHORT WAVE TROUGH...THIS WAS ASSOCIATED WITH THE SURFACE
COLD FRONT WILL MOVE ACROSS OUR REGION TUESDAY AFTERNOON AND
EVENING. GUIDANCE IS BEGINNING TO SHOW A WEAK SURFACE WAVE MAY
DEVELOP ACROSS CENTRAL NC ON THE FRONT TUESDAY AFTERNOON AND
EVENING. EXPECT FAIRLY GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS ON
TUESDAY WITH THE BEST COVERAGE EXPECTED ACROSS THE EASTERN PIEDMONT
AND COASTAL PLAIN AHEAD OF THE SURFACE WAVE AND IN A REGION OF
GREATER INSTABILITY. IT WILL BE A LITTLE COOLER ON TUESDAY WITH
HIGHS RANGING FROM THE MID 80S ACROSS THE WESTERN PIEDMONT TO THE
UPPER 80S ACROSS THE COASTAL PLAIN. LOWS TUESDAY NIGHT WILL RANGE
FROM THE LOW 60S ACROSS THE NORTHWEST PIEDMONT TO THE UPPER 60S IN
THE SOUTHERN COASTAL PLAIN.

THE FRONT WILL CONTINUE TO SHIFT SOUTH OF CENTRAL NC ON WEDNESDAY
BUT A FEW SHOWERS MAY LINGER INTO EARLY WEDNESDAY ACROSS THE
SOUTHERN COASTAL PLAIN AND SANDHILLS. OTHERWISE HIGH PRESSURE WILL
BUILD INTO THE REGION ON WEDNESDAY AND THURSDAY WITH GENERALLY FAIR
WEATHER AND SEASONABLE TEMPERATURES. A COLD FRONT WILL PUSH SOUTH
ACROSS THE MID ATLANTIC LATE THURSDAY AND EARLY FRIDAY BRINGING
ADDITIONAL CLOUDINESS AND EVEN COOLER TEMPERATURES. PRECIPITATION
CHANCES APPEAR LIMITED ACROSS CENTRAL NC WITH THIS FEATURE. HIGH
TEMPERATURES WILL RANGE IN THE LOWER TO MID 80S WITH FRIDAY BEING
THE COOLEST DAY. MORNING LOWS SHOULD RANGE IN THE LOWER TO MID 60S.
-BLAES
&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...

ADVERSE AVIATION CONDITIONS IN FOG ARE EXPECTED AT FAY/RWI AND
POTENTIALLY RDU EARLY THIS MORNING (INT/GSO SHOULD REMAIN MOSTLY
VFR). THE NARROW WEAK SURFACE RIDGE CONTINUES TO EXTEND FROM
OFFSHORE WESTWARD ACROSS NC... RESULTING IN VERY LIGHT MAINLY
SOUTHERLY BREEZE. WITH THE LACK OF HIGHER CLOUDS FACILITATING
RADIATIONAL COOLING AND LOW LEVEL DECOUPLING... WINDS SHOULD BECOME
CALM OR NEARLY CALM. THE HRRR (AMONG OTHER MODELS) FAVORS IFR FOG
FORMING NEAR FAY/RWI AFTER 09Z AND POTENTIALLY EXPANDING TOWARD RDU
AFTER 11Z. THIS AGREES WELL WITH STATISTICAL GUIDANCE AS WELL AS
PERSISTENCE. WILL FAVOR FOG OVER STRATUS AT RWI/FAY/RDU GIVEN THAT
WINDS HAVE ALREADY DIMINISHED OVER MUCH OF THE AREA. THESE IFR
CONDITIONS ARE EXPECTED TO MIX OUT TO VFR BY 13Z-14Z. VFR CONDITIONS
WILL THEN DOMINATE ALL SITES THROUGH THE END OF THE TAF VALID PERIOD
(06Z EARLY SUNDAY MORNING)... ALTHOUGH INT/GSO WILL SEE A RISK OF
SCATTERED STORMS PRODUCING BRIEF SUB-VFR CONDITIONS AND A FEW WIND
GUSTS BETWEEN 21Z AND 03Z THIS AFTERNOON/EVENING... AS AN UPPER
LEVEL DISTURBANCE APPROACHES FROM THE NW.

LOOKING BEYOND 06Z EARLY SUNDAY MORNING... THERE IS ANOTHER CHANCE
OF SHALLOW PATCHY FOG 09Z-13Z SUNDAY MORNING AS HUMIDITY STEADILY
INCREASES WITH LIGHT SW FLOW... BUT THE CHANCE IS LOWER THAN IN PAST
COUPLE OF DAYS AS WE`LL SEE MORE MID/HIGH CLOUDS ROLLING IN.
OTHERWISE... VFR CONDITIONS WILL PREVAIL THROUGH THIS PERIOD... BUT
BETTER SHOWER/STORM COVERAGE IS EXPECTED ACROSS CENTRAL NC SUNDAY
AND MONDAY AFTERNOONS/EARLY EVENING AS A LOW PRESSURE TROUGH ALOFT
STRENGTHENS OVER THE EASTERN U.S.  THESE STORMS MAY PRODUCE A PERIOD
OF SUB-VFR CONDITIONS AND GUSTY WINDS. STORM CHANCE COULD LINGER
INTO TUESDAY IN THE EAST... THEN COLD FRONT PASSAGE BY TUESDAY NIGHT
SHOULD BRING VFR CONDITIONS AND DRY WEATHER FOR WEDNESDAY. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BLAES
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...BLAES
AVIATION...HARTFIELD










AREA FORECAST DISCUSSION

NWS RALEIGH NC

 250 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM MOIST SOUTHERLY FLOW WILL PERSIST THROUGH THE WEEKEND. A SLOW
MOVING COLD FRONT WILL APPROACH THE REGION ON MONDAY AND THEN PUSH
THROUGH THE AREA ON TUESDAY. HIGH PRESSURE WILL MOVE INTO THE REGION
ON WEDNESDAY AND LINGER ON THURSDAY. ANOTHER COLD FRONT WILL CROSS
THE REGION ON FRIDAY.

&&

.NEAR TERM /TODAY AND TONIGHT/...
AS OF 250 AM SATURDAY...

STILL LOOKS LIKE A FEW SHOWERS/STORMS OVER THE WRN/SRN PORTIONS OF
THE FORECAST AREA LATE TODAY... WHILE ERN SECTIONS SHOULD REMAIN
DRY. LATEST SURFACE MAP SHOWS THE WEAK OFFSHORE-CENTERED SURFACE
HIGH EXTENDING WESTWARD OVER NC... WHILE A COLD FRONT SITS WELL TO
OUR NW ACROSS THE LOWER GREAT LAKES. A PROMINENT BUT WEAKENING MID
LEVEL SHORTWAVE HAS DROPPED SE OVER THE ST LAWRENCE VALLEY/SRN MI
OVER THE LAST FEW HOURS AND SHOULD CONTINUE TO TRACK SE TOWARD THE
OH VALLEY AND CENTRAL APPALACHIANS THIS MORNING... BEFORE SHIFTING
EASTWARD ACROSS THE MIDATLANTIC REGION LATER TODAY AND TONIGHT. MID
LEVEL FLOW GETS MUCH WEAKER AS FAR SOUTH AS NC AND MUCH OF THE
BETTER DPVA SHIFTS BY WELL TO OUR NORTH... BUT THE APPROACH OF ANY
RESIDUAL OUTFLOW EMANATING FROM THE OH VALLEY CONVECTION WILL BE
MOVING INTO WRN NC LATE TODAY INTO AN AREA OF MODERATE INSTABILITY
(FORECAST MLCAPE OVER FAR WRN PIEDMONT OF 1000-1500 J/KG)... WHILE
NEAR-NORMAL PW VALUES INCREASE QUICKLY TODAY TO 1.8-2.0 INCHES...
WITH GOOD HEATING EXPECTED AND INCREASING 850 MB THETA-E OVER WRN
NC. WHILE THE ERN CWA SHOULD REMAIN FAIRLY STABLE TODAY WITH A LATER
INCREASE IN MOISTURE... MODEL OUTPUT (INCLUDING CONVECTION-ALLOWING
MODELS) AND EXTRAPOLATION OF UPSTREAM FEATURES WOULD CERTAINLY
SUPPORT 20-40% COVERAGE OF STORMS LATE TODAY THROUGH MID EVENING
OVER THE WRN/SRN PIEDMONT MAINLY WEST OF THE TRIANGLE. WEAK ELEVATED
INSTABILITY AROUND 500-600 J/KG PERSISTS OVER THE PIEDMONT
OVERNIGHT... WHICH IN CONJUNCTION WITH THE ABOVE-NORMAL PW VALUES
WARRANTS A MENTION OF ISOLATED SHOWERS LINGERING OVERNIGHT. DEEP
LAYER SHEAR REMAINS QUITE WEAK AND FORECAST SOUNDINGS DO NOT SUGGEST
A DOWNBURST WIND POTENTIAL... SO DO NOT EXPECT ANY STRONG OR SEVERE
STORMS. HIGHS 85-90 AND LOWS 67-71. -GIH

&&

.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 315 PM FRIDAY...

TO BE UPDATED SHORTLY.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...

DURING THE FIRST HALF OF THE LONG TERM (SUNDAY THROUGH TUESDAY)
WE`LL SEE A LONGWAVE TROUGH DEEPEN OVER THE EASTERN STATES. MOISTURE
WILL GRADUALLY INCREASE DURING THIS PERIOD GIVEN SW FLOW AHEAD OF A
COLD FRONT THATS PROGGED TO MOVE ACROSS OUR AREA LATE TUESDAY.
INDIVIDUAL SHORT WAVES EMBEDDED WITHIN THE LARGER TROUGH WILL
RESULT IN PERIODIC INCREASES IN RAIN CHANCES.

ON SUNDAY...THE FIRST OF THESE SHORT WAVES WILL APPROACH LATE IN THE
DAY...SO WILL CONTINUE FORECAST INDICATING 25-35 POPS...HIGHEST WEST
GIVEN TIMING OF THE APPROACH OF THIS WAVE. THE NEXT WAVE IS PROGGED
TO APPROACH LATE ON MONDAY AND MOVE ACROSS THE CAROLINAS MONDAY
NIGHT. THIS WAVE WILL HAVE ADDITIONAL MOISTURE TO WORK WITH...SO
LOOK FOR BETTER PRECIP CHANCES/COVERAGE LATE MONDAY AND MONDAY NIGHT
COMPARED TO THE PREVIOUS DAY. HOWEVER GIVEN LATE DAY OR NIGHT TIMING
AND 0-6KM BULK SHEAR LESS THAN 20KT...FEEL THE SEVERE THREAT WILL
REMAIN LIMITED.

THE LAST IN THIS SERIES OF SHORT WAVES...AND FINALLY THE COLD
FRONT...WILL MOVE ACROSS OUR REGION TUESDAY AFTERNOON AND EVENING.
LOOK FOR SCATTERED SHOWERS/TSTMS ALONG AND AHEAD OF THE FRONT DURING
THE AFTERNOON AND EVENING...WITH BEST CHANCES SHIFTING TO OUR
COASTAL PLAIN ZONES LATER IN THE DAY. WHILE MOISTURE AND INSTABILITY
WILL BE ADEQUATE FOR TSTMS...0-6KM SHEAR IS STILL PROGGED TO REMAIN
BELOW 30KT...SO WIDESPREAD SEVERE THUNDERSTORMS IS NOT EXPECTED
ATTM...BUT WILL CONTINUE TO MONITOR TRENDS.

HIGH PRESSURE WILL BUILD ACROSS THE AREA BEHIND THE FRONT ON
WEDNESDAY...PROVIDING FAIR AND SEASONABLE WEATHER WEDNESDAY AND
THURSDAY. A WEAK BACKDOOR COLD FRONT WILL THEN MOVE ACROSS OUR AREA
THURSDAY NIGHT INTO EARLY FRIDAY...BUT SHOULD MOVE THROUGH WITH
LITTLE OR NO PRECIP GIVEN DRY AIRMASS IN PLACE AHEAD OF THE FRONT.

TEMPS WILL REMAIN ABOVE NORMAL (HIGHS IN THE LOW 90S AND LOWS NEAR
70) SUNDAY THROUGH TUESDAY AHEAD OF THE COLD FRONT...THEN COOLING
BACK TO NEAR-NORMAL (HIGHS IN THE MID 80S AND LOWS IN THE MID 60S)
FOR THE MID TO LATTER PORTION OF THE WEEK.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...

ADVERSE AVIATION CONDITIONS IN FOG ARE EXPECTED AT FAY/RWI AND
POTENTIALLY RDU EARLY THIS MORNING (INT/GSO SHOULD REMAIN MOSTLY
VFR). THE NARROW WEAK SURFACE RIDGE CONTINUES TO EXTEND FROM
OFFSHORE WESTWARD ACROSS NC... RESULTING IN VERY LIGHT MAINLY
SOUTHERLY BREEZE. WITH THE LACK OF HIGHER CLOUDS FACILITATING
RADIATIONAL COOLING AND LOW LEVEL DECOUPLING... WINDS SHOULD BECOME
CALM OR NEARLY CALM. THE HRRR (AMONG OTHER MODELS) FAVORS IFR FOG
FORMING NEAR FAY/RWI AFTER 09Z AND POTENTIALLY EXPANDING TOWARD RDU
AFTER 11Z. THIS AGREES WELL WITH STATISTICAL GUIDANCE AS WELL AS
PERSISTENCE. WILL FAVOR FOG OVER STRATUS AT RWI/FAY/RDU GIVEN THAT
WINDS HAVE ALREADY DIMINISHED OVER MUCH OF THE AREA. THESE IFR
CONDITIONS ARE EXPECTED TO MIX OUT TO VFR BY 13Z-14Z. VFR CONDITIONS
WILL THEN DOMINATE ALL SITES THROUGH THE END OF THE TAF VALID PERIOD
(06Z EARLY SUNDAY MORNING)... ALTHOUGH INT/GSO WILL SEE A RISK OF
SCATTERED STORMS PRODUCING BRIEF SUB-VFR CONDITIONS AND A FEW WIND
GUSTS BETWEEN 21Z AND 03Z THIS AFTERNOON/EVENING... AS AN UPPER
LEVEL DISTURBANCE APPROACHES FROM THE NW.

LOOKING BEYOND 06Z EARLY SUNDAY MORNING... THERE IS ANOTHER CHANCE
OF SHALLOW PATCHY FOG 09Z-13Z SUNDAY MORNING AS HUMIDITY STEADILY
INCREASES WITH LIGHT SW FLOW... BUT THE CHANCE IS LOWER THAN IN PAST
COUPLE OF DAYS AS WE`LL SEE MORE MID/HIGH CLOUDS ROLLING IN.
OTHERWISE... VFR CONDITIONS WILL PREVAIL THROUGH THIS PERIOD... BUT
BETTER SHOWER/STORM COVERAGE IS EXPECTED ACROSS CENTRAL NC SUNDAY
AND MONDAY AFTERNOONS/EARLY EVENING AS A LOW PRESSURE TROUGH ALOFT
STRENGTHENS OVER THE EASTERN U.S.  THESE STORMS MAY PRODUCE A PERIOD
OF SUB-VFR CONDITIONS AND GUSTY WINDS. STORM CHANCE COULD LINGER
INTO TUESDAY IN THE EAST... THEN COLD FRONT PASSAGE BY TUESDAY NIGHT
SHOULD BRING VFR CONDITIONS AND DRY WEATHER FOR WEDNESDAY. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BLAES
NEAR TERM...HARTFIELD
SHORT TERM...VINCENT
LONG TERM...NP
AVIATION...HARTFIELD







AREA FORECAST DISCUSSION

NWS RALEIGH NC

 1250 AM EDT SAT AUG 31 2013

.SYNOPSIS...
A WARM MOIST SOUTHERLY FLOW WILL PERSIST THROUGH THE WEEKEND. A SLOW
MOVING COLD FRONT WILL APPROACH THE REGION ON MONDAY AND THEN PUSH
THROUGH THE AREA ON TUESDAY. HIGH PRESSURE WILL MOVE INTO THE REGION
ON WEDNESDAY AND LINGER ON THURSDAY. ANOTHER COLD FRONT WILL CROSS
THE REGION ON FRIDAY.

&&

.NEAR TERM /OVERNIGHT/...
AS OF 1000 PM FRIDAY...

A RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT PROVIDING CENTRAL
NC WITH DRY AND STABLE CONDITIONS THIS EVENING. ASIDE FROM A FEW
PASSING CIRRUS...SKIES WILL REMAIN CLEAR OVERNIGHT. AS THE LOW LEVEL
AIR MASS COOLS...PATCHES OF FOG AND/OR LOW CLOUDS WILL DEVELOP. THIS
LAYER OF MOISTURE WILL REMAIN RELATIVELY THIN SO THE FOG AND/OR LOW
CLOUDS SHOULD LIFT AND DISSIPATE WITHIN AN HOUR OR TWO OF SUNRISE.

MIN TEMPS IN THE MID-UPPER 60S APPEAR ON TARGET AT THIS TIME.

&&

.SHORT TERM /SATURDAY THROUGH SATURDAY NIGHT/...
AS OF 315 PM FRIDAY...

WEAK CYCLONIC FLOW ALOFT WILL PREVAIL ACROSS THE MID-ATLANTIC SAT
AND SAT NIGHT...BETWEEN AN H5 RIDGE UPSTREAM OVER THE CENTRAL
PLAINS/ROCKIES AND A DOWNSTREAM RIDGE OFFSHORE THE SOUTHEAST COAST.
WEAK (ALBEIT PERSISTENT) SOUTHERLY RETURN FLOW WILL RESULT IN STEADY
LOW-LEVEL MOISTENING ON SAT...WITH PWAT VALUES IN THE 1.50-2.00"
RANGE BY 00Z SUNDAY. THE DEEPEST MOISTURE IS EXPECTED OVER WESTERN
PORTIONS OF THE STATE...WITH A RELATIVELY DRIER AND WARMER MID-LEVEL
AIRMASS OVER EASTERN PORTIONS OF THE STATE IN CLOSER VICINITY TO THE
RIDGE OFFSHORE THE SOUTHEAST COAST. EXPECT SEASONAL DIURNAL
DESTABILIZATION DURING PEAK HEATING...WITH MLCAPE VALUES IN THE
1000-2000 J/KG RANGE...HIGHEST IN VICINITY OF THE HWY 1 CORRIDOR
WHERE THE MOST FAVORABLE JUXTAPOSITION OF LOW-LEVEL MOISTURE...
INSOLATION AND COOLER MID-LEVEL TEMPS ARE PROGGED. FORCING FOR
ASCENT WILL BE RATHER ANEMIC ON SAT...MOST LIKELY LIMITED TO
WEAK/SHALLOW CONVERGENCE ASSOC/W A LEE TROUGH IN THE WESTERN
PIEDMONT. THE BEST SHORTWAVE ENERGY /DPVA/ WILL MOST LIKELY REMAIN
FURTHER NORTH IN THE MID-ATLANTIC WHERE CYCLONIC FLOW ALOFT WILL BE
BETTER ESTABLISHED...THOUGH A SMALL AMPLITUDE DISTURBANCE CANNOT BE
RULED OUT DURING THE AFT/EVE HOURS. WITH THE ABOVE IN MIND...WILL
INDICATE A 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS ALONG AND WEST
OF THE HIGHWAY 1 CORRIDOR...HIGHEST ACROSS THE NW PIEDMONT IN
VICINITY OF THE LEE TROUGH AND WHERE CAPPING/DRY AIR ENTRAINMENT
WILL BE LESS OF AN ISSUE THAN ACROSS EASTERN PORTIONS OF THE STATE.
EXPECT HIGHS IN THE MID TO UPPER 80S...WARMEST ALONG AND EAST OF
HIGHWAY 1 WHERE LESS CLOUD COVER IS ANTICIPATED. WILL REMOVE THE
AFOREMENTIONED CHANCES FOR CONVECTION BY MIDNIGHT GIVEN ANEMIC
FORCING COUPLED WITH NOCTURNAL STABILIZATION...WITH THE CAVEAT THAT
SMALL AMPLITUDE DISTURBANCES ALOFT (IF PRESENT) COULD PERHAPS
SUPPORT A FEW ISOLD SHOWERS OVERNIGHT GIVEN DEEP MOISTURE. LOWS SAT
NIGHT IN THE UPPER 60S TO LOWER 70S. -VINCENT

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...

DURING THE FIRST HALF OF THE LONG TERM (SUNDAY THROUGH TUESDAY)
WE`LL SEE A LONGWAVE TROUGH DEEPEN OVER THE EASTERN STATES. MOISTURE
WILL GRADUALLY INCREASE DURING THIS PERIOD GIVEN SW FLOW AHEAD OF A
COLD FRONT THATS PROGGED TO MOVE ACROSS OUR AREA LATE TUESDAY.
INDIVIDUAL SHORT WAVES EMBEDDED WITHIN THE LARGER TROUGH WILL
RESULT IN PERIODIC INCREASES IN RAIN CHANCES.

ON SUNDAY...THE FIRST OF THESE SHORT WAVES WILL APPROACH LATE IN THE
DAY...SO WILL CONTINUE FORECAST INDICATING 25-35 POPS...HIGHEST WEST
GIVEN TIMING OF THE APPROACH OF THIS WAVE. THE NEXT WAVE IS PROGGED
TO APPROACH LATE ON MONDAY AND MOVE ACROSS THE CAROLINAS MONDAY
NIGHT. THIS WAVE WILL HAVE ADDITIONAL MOISTURE TO WORK WITH...SO
LOOK FOR BETTER PRECIP CHANCES/COVERAGE LATE MONDAY AND MONDAY NIGHT
COMPARED TO THE PREVIOUS DAY. HOWEVER GIVEN LATE DAY OR NIGHT TIMING
AND 0-6KM BULK SHEAR LESS THAN 20KT...FEEL THE SEVERE THREAT WILL
REMAIN LIMITED.

THE LAST IN THIS SERIES OF SHORT WAVES...AND FINALLY THE COLD
FRONT...WILL MOVE ACROSS OUR REGION TUESDAY AFTERNOON AND EVENING.
LOOK FOR SCATTERED SHOWERS/TSTMS ALONG AND AHEAD OF THE FRONT DURING
THE AFTERNOON AND EVENING...WITH BEST CHANCES SHIFTING TO OUR
COASTAL PLAIN ZONES LATER IN THE DAY. WHILE MOISTURE AND INSTABILITY
WILL BE ADEQUATE FOR TSTMS...0-6KM SHEAR IS STILL PROGGED TO REMAIN
BELOW 30KT...SO WIDESPREAD SEVERE THUNDERSTORMS IS NOT EXPECTED
ATTM...BUT WILL CONTINUE TO MONITOR TRENDS.

HIGH PRESSURE WILL BUILD ACROSS THE AREA BEHIND THE FRONT ON
WEDNESDAY...PROVIDING FAIR AND SEASONABLE WEATHER WEDNESDAY AND
THURSDAY. A WEAK BACKDOOR COLD FRONT WILL THEN MOVE ACROSS OUR AREA
THURSDAY NIGHT INTO EARLY FRIDAY...BUT SHOULD MOVE THROUGH WITH
LITTLE OR NO PRECIP GIVEN DRY AIRMASS IN PLACE AHEAD OF THE FRONT.

TEMPS WILL REMAIN ABOVE NORMAL (HIGHS IN THE LOW 90S AND LOWS NEAR
70) SUNDAY THROUGH TUESDAY AHEAD OF THE COLD FRONT...THEN COOLING
BACK TO NEAR-NORMAL (HIGHS IN THE MID 80S AND LOWS IN THE MID 60S)
FOR THE MID TO LATTER PORTION OF THE WEEK.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1245 AM SATURDAY...

ADVERSE AVIATION CONDITIONS IN FOG ARE EXPECTED AT FAY/RWI AND
POTENTIALLY RDU EARLY THIS MORNING (INT/GSO SHOULD REMAIN MOSTLY
VFR). THE NARROW WEAK SURFACE RIDGE CONTINUES TO EXTEND FROM
OFFSHORE WESTWARD ACROSS NC... RESULTING IN VERY LIGHT MAINLY
SOUTHERLY BREEZE. WITH THE LACK OF HIGHER CLOUDS FACILITATING
RADIATIONAL COOLING AND LOW LEVEL DECOUPLING... WINDS SHOULD BECOME
CALM OR NEARLY CALM. THE HRRR (AMONG OTHER MODELS) FAVORS IFR FOG
FORMING NEAR FAY/RWI AFTER 09Z AND POTENTIALLY EXPANDING TOWARD RDU
AFTER 11Z. THIS AGREES WELL WITH STATISTICAL GUIDANCE AS WELL AS
PERSISTENCE. WILL FAVOR FOG OVER STRATUS AT RWI/FAY/RDU GIVEN THAT
WINDS HAVE ALREADY DIMINISHED OVER MUCH OF THE AREA. THESE IFR
CONDITIONS ARE EXPECTED TO MIX OUT TO VFR BY 13Z-14Z. VFR CONDITIONS
WILL THEN DOMINATE ALL SITES THROUGH THE END OF THE TAF VALID PERIOD
(06Z EARLY SUNDAY MORNING)... ALTHOUGH INT/GSO WILL SEE A RISK OF
SCATTERED STORMS PRODUCING BRIEF SUB-VFR CONDITIONS AND A FEW WIND
GUSTS BETWEEN 21Z AND 03Z THIS AFTERNOON/EVENING... AS AN UPPER
LEVEL DISTURBANCE APPROACHES FROM THE NW.

LOOKING BEYOND 06Z EARLY SUNDAY MORNING... THERE IS ANOTHER CHANCE
OF SHALLOW PATCHY FOG 09Z-13Z SUNDAY MORNING AS HUMIDITY STEADILY
INCREASES WITH LIGHT SW FLOW... BUT THE CHANCE IS LOWER THAN IN PAST
COUPLE OF DAYS AS WE`LL SEE MORE MID/HIGH CLOUDS ROLLING IN.
OTHERWISE... VFR CONDITIONS WILL PREVAIL THROUGH THIS PERIOD... BUT
BETTER SHOWER/STORM COVERAGE IS EXPECTED ACROSS CENTRAL NC SUNDAY
AND MONDAY AFTERNOONS/EARLY EVENING AS A LOW PRESSURE TROUGH ALOFT
STRENGTHENS OVER THE EASTERN U.S.  THESE STORMS MAY PRODUCE A PERIOD
OF SUB-VFR CONDITIONS AND GUSTY WINDS. STORM CHANCE COULD LINGER
INTO TUESDAY IN THE EAST... THEN COLD FRONT PASSAGE BY TUESDAY NIGHT
SHOULD BRING VFR CONDITIONS AND DRY WEATHER FOR WEDNESDAY. -GIH

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...BLAES
NEAR TERM...WSS
SHORT TERM...VINCENT
LONG TERM...NP
AVIATION...HARTFIELD







AREA FORECAST DISCUSSION

NWS BISMARCK ND

 1256 AM CDT SAT AUG 31 2013

.UPDATE...
ISSUED AT 224 AM CDT SAT AUG 31 2013

THE PRIMARY UPDATE THIS MORNING WAS TO ACCOUNT FOR CURRENT RADAR
TRENDS. THE LAST COUPLE RUNS OF THE HRRR SUGGEST THAT THE ONGOING
THUNDERSTORMS EAST OF BISMARCK. TRENDS AND MESOANALYSIS SUGGEST
THAT THE STORMS WILL REMAIN SUB-SEVERE.

THE MAIN FOCUS AFTER THUNDERSTORMS MOVE OUT WILL BE THE CHANCE FOR
A FEW THUNDERSTORMS SATURDAY AFTERNOON/EVENING BEFORE TEMPERATURES
FINALLY COOL DOWN ON SUNDAY.

UPDATE ISSUED AT 1115 PM CDT FRI AUG 30 2013

AFTER COORDINATING WITH SPC AND GIVEN THE DECREASING CONVECTIVE
TRENDS...ALLOWED THE WATCH TO EXPIRE AT 11 PM CDT. WILL CONTINUE
TO MONITOR ONGOING CONVECTION TONIGHT AND ISSUE APPROPRIATE SHORT-
FUSED WARNINGS AS NEEDED. GIVEN THE THREAT IS NOT ZERO...STILL
HIGHLIGHTED THE STRONG TO SEVERE THUNDERSTORM POTENTIAL IN THE
HWO. THE UPDATED PRODUCTS HAVE BEEN SENT.

UPDATE ISSUED AT 940 PM CDT FRI AUG 30 2013

UPDATED THE FORECAST TO REMOVE A TIER OF WESTERN COUNTIES FROM THE
SEVERE THUNDERSTORM WATCH...AND ADDED A TIER OF EASTERN COUNTIES
TO THE WATCH BASED ON CURRENT RADAR TRENDS.

LAPS ANALYSIS CONTINUES TO SHOW A DECREASING TREND IN CAPE. THE
WATCH IS STILL IS VALID UNTIL 11 PM CDT WITH LITTLE ADDITIONAL
CONVECTIVE DEVELOPMENT EXPECTED AFTER 11 PM. WILL CONTINUE TO
MONITOR TRENDS AND UPDATE THE FORECAST AS NEEDED. THE UPDATED
PRODUCTS HAVE BEEN SENT.

UPDATE ISSUED AT 707 PM CDT FRI AUG 30 2013

VISIBLE SATELLITE IMAGERY NICELY DEPICTS THE LOCATION OF A PRE-
FRONTAL TROUGH THAT IS SERVING AS A FOCUS FOR SEVERE CONVECTION.
THIS SURFACE BOUNDARY WILL CONTINUE TO PUSH EAST THROUGH THE
OVERNIGHT HOURS.

BEHIND THE FRONT...MORE STABLE AIR EXISTS OVER EXTREME WESTERN
NORTH DAKOTA. NOT EXPECTING ANY CONVECTION ALONG AND WEST OF
HIGHWAY 85 TONIGHT. AS A RESULT...CANCELLED THE SEVERE
THUNDERSTORM WATCH FOR AREAS ALONG AND WEST OF HIGHWAY 85. A
SEVERE THUNDERSTORM COULD IMPACT THE EXTREME SOUTHWESTERN PORTION
OF BOWMAN COUNTY BETWEEN 9 PM MDT AND 10 PM MDT. HOWEVER...NOT
REAL CONFIDENT THE STORM WILL HOLD TOGETHER FOR THAT LONG. STILL
CANCELLED THE WATCH FOR BOWMAN COUNTY...BUT MENTIONED THE THREAT
IN THE HWO. THE UPDATED PRODUCTS HAVE BEEN SENT.

UPDATE ISSUED AT 432 PM CDT FRI AUG 30 2013

UPDATED THE FORECAST FOR SEVERE THUNDERSTORM WATCH NUMBER 506.

CONVECTION IS ALREADY FIRING ALONG A PRE-FRONTAL TROUGH OVER
WESTERN NORTH DAKOTA. LAPS IS ANALYZING SURFACE-BASED CAPE VALUES
RANGING FROM 2000-2500 J/KG AHEAD OF THE BOUNDARY. THE ATMOSPHERE
IS PRIMED FOR SEVERE WEATHER DEVELOPMENT OVER WESTERN AND PORTIONS
OF CENTRAL NORTH DAKOTA LATER THIS AFTERNOON/EVENING. WILL
CONTINUE TO MONITOR TRENDS.

THE UPDATED PRODUCTS HAVE BEEN SENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)

ISSUED AT 232 PM CDT FRI AUG 30 2013

THE HIGHLIGHT OF THE SHORT TERM IS SEVERE CONVECTIVE DEVELOPMENT
LATE THIS AFTERNOON AND INTO THE EVENING.

REALLY NOT MUCH CHANGE IN THINKING IN REGARDS TO THE EVOLUTION AND
ASSOCIATED THREATS WITH THE ANTICIPATED CONVECTION. THE 18 UTC
HRRR/RAP CONTINUE THE TRENDS OF INITIATING CONVECTION ALONG A
PRE-FRONTAL TROUGH FROM HETTINGER THROUGH SHERWOOD FROM BETWEEN
20-22 UTC. THIS IS IN LINE WITH THE 12 UTC NAM/GFS/GEM/WRF AND THE
00 UTC WRF AND SPC SSEO. -10 TO -30 HAIL CAPE VALUES OF 700-900 J/KG
WITH DEEP LAYER SHEAR OF 40-50 KTS SUGGESTS LARGE HAIL WILL BE A
PRIMARY THREAT...ALONG WITH DAMAGING WINDS WITH DOWNDRAFT CAPE
VALUES AOA 1000 J/KG. LOCALLY HEAVY RAINFALL IS ALSO EXPECTED WITH
PWATS NEAR 1.50 INCHES. WHILE THE TORNADIC THREAT IS LOW...ANY
SUPERCELLS THAT CAN INTERACT WITH THE TROUGH MAY PRESENT A LOCALIZED
THREAT FOR TORNADOES. STORMS ARE EXPECTED TO BE FOCUSED EAST OF
HIGHWAY 83 POST 00 UTC...SUSTAINED BY A 25 KT LOW LEVEL JET.

FOR SATURDAY...A COOLER AND NOTABLY DRIER DAY IS FORECAST ACROSS THE
AREA IN THE WAKE OF A COLD FRONT THAT WILL ENTER NORTHWEST NORTH
DAKOTA TONIGHT AND CLEAR THE SOUTHEAST PORTIONS OF THE CWA BY 18
UTC. BREEZY NORTHWEST WINDS AND DEWPOINTS DROPPING INTO THE 40S WILL
LEAD TO HIGH FIRE DANGER ACROSS THE SOUTHWEST...HOWEVER...CRITICAL
FIRE WEATHER CONDITIONS AND HEADLINES ARE NOT ANTICIPATED.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)

ISSUED AT 232 PM CDT FRI AUG 30 2013

SURFACE COLD FRONT SWEEPING SOUTHEAST ACROSS THE STATE SATURDAY
MORNING/AFTERNOON SHOULD BE MOSTLY SOUTH AND EAST OF THE JAMES RIVER
VALLEY BY 00Z SUNDAY/EARLY SATURDAY EVENING. THERE STILL MAY BE SOME
LINGERING CONVECTION ACROSS PORTIONS OF THE JAMES RIVER VALLEY
AROUND 00Z...SO WILL MAINTAIN A SLIGHT CHANCE FOR THUNDERSTORMS
ACROSS LAMOURE AND DICKEY COUNTIES IN THE EVENING...DRY ALL AREAS
AFTER 06Z.

DRY...SUNNY...AND MUCH COOLER (HIGHS 70-80) FOR SUNDAY AS CANADIAN
HIGH PRESSURE BUILDS ACROSS THE NORTHERN PLAINS.

AFTER SUNDAY...WILL SEE A SLOW WARMING TREND BACK TO ABOVE NORMAL
TEMPERATURES THROUGH THE WORK WEEK AS THE UPPER RIDGE REBUILDS
ACROSS THE ROCKIES. HOT CONDITIONS POSSIBLE BY THE END OF THE WORK
WEEK/EARLY NEXT WEEKEND WITH THE 12Z GFS/EC INDICATING ANYWHERE FROM
26-30C 850MB ISOTHERMS OVER THE DAKOTAS. EXPECT MOSTLY DRY
CONDITIONS OVER NORTH DAKOTA MONDAY/MONDAY NIGHT WITH A DRY
NORTHWEST FLOW ALOFT. AFTERWARDS...WITH THE EXCEPTION OF POSSIBLE
EMBEDDED WAVES UNDERCUTTING THE RIDGE...SHOULD REMAIN MAINLY DRY
UNTIL THE END OF THE WORK WEEK/SOMETIME NEXT WEEKEND WHEN MODELS
PROJECT A STRONG COLD FRONTAL PASSAGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1224 AM CDT SAT AUG 31 2013

VFR CONDITIONS WILL PREVAIL AT ALL AERODROMES. KJMS COULD STILL
SEE THUNDERSTORMS OVER THE NEXT FEW HOURS...BUT WILL CLEAR OUT BY
08Z.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...SCHECK
SHORT TERM...AYD
LONG TERM...NH
AVIATION...SCHECK







AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 733 PM EDT SUN SEP 1 2013

.SYNOPSIS...
MUGGY ENVIRONMENT LINGERS INTO MONDAY EVENING. COLD FRONT MONDAY
NIGHT. COOLER AND DRIER AIRMASS TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /THROUGH MONDAY/...
AFTERNOON DISTURBANCE EXITING SOUTHERN MOUNTAINS AND GREENBRIER
VALLEY NOW.  WAS FASTER LOWERING POPS DOWN THIS EVENING.  ALSO
FASTER FORMING SOME VALLEY FOG IN THE SOUTHERN COAL FIELDS AND
GREENBRIER VALLEY IN WAKE OF THE LATE AFTERNOON SHOWERS.

DESPITE THE LACK OF CONVECTION AND CLOUDS OVER OUR WESTERN
LOWLANDS...STILL THINK A LATE NIGHT OR MORNING SHOWER OR
THUNDERSTORM COULD REFORM OVERNIGHT.  SO ONLY REMOVAL OF POPS WAS
EARLY THIS EVENING BEFORE INCREASING BACK INTO THE 20 TO 30 PERCENT
RANGE FOR ANY ONE SPOT. RAP INDICATES A WEAK MID LEVEL DISTURBANCE
PASSING SE OHIO AROUND 03Z TO 05Z AND IN WV AFTER 05Z.

THIS PLAYS HAVOC WITH FIGURING OUT THE FOG COVERAGE FOR THE PREDAWN.


&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
COLD FRONT FINALLY DEPARTS MONDAY NIGHT WITH HIGH PRESSURE BUILDING
IN BEHIND THE SYSTEM. VERY DRY AIR TO ADVECT IN BEHIND THE FRONT FOR
TUESDAY...ALTHOUGH MAY START OUT WITH SOME LOW LEVEL STRATUS IN
PLACE AS NAM BUFR SOUNDINGS SUGGEST SATURATION BELOW 875MB AND
NORTHERLY FLOW AT 925MB. LOW STRATUS DECK SHOULD LIFT AND DISSOLVE
BY LATE MORNING TUESDAY AND BE REPLACED IN THE AFTERNOON BY DIURNAL
CUMULUS AS A RESULT OF BOUNDARY LAYER MIXING. WILL BE COMPLETELY
DEVOID OF ANY MOISTURE ALL THE WAY THROUGH WEDNESDAY...LESS SOME
PATCHY THIN CIRRUS DRIFTING THROUGH ON WEDNESDAY AFTERNOON.

WITH A NEW AIRMASS IN PLACE...CAN EXPECT MORE TYPICAL LATE SUMMER
CONDITIONS IN TERMS OF TEMPERATURES AND DEWPOINTS AT THE SURFACE.
DRIER AIR AND INSOLATION WILL ALLOW TEMPERATURES TO DROP INTO THE
50S TUESDAY NIGHT...WITH SOME ISOLATED 40S IN THE LOWLANDS...AND
MORE PREVALENT IN THE MOUNTAINS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
EXTENDED FORECAST REMAINS PRIMARILY DRY. HIGH PRESSURE IN CONTROL
INTO THE EARLY PART OF THE WEEKEND...BUT MAY GET THE TAIL END OF A
COLD FRONT FOR THE END OF THE WEEK. THIS WOULD HAVE LITTLE AFFECT ON
THE MIDDLE OHIO VALLEY AND CENTRAL APPALACHIANS OTHER THAN A LITTLE
CLOUD COVER. LONG RANGE MODELS DEVELOP A SURFACE LOW IN THE CENTRAL
PLAINS FOR THE END OF THE WEEKEND WITH A WARM FRONT TO OUR NORTH. IN
THE END...HEIGHTS MAKE A RECOVERY FROM THE MILDER AIRMASS AT THE
BEGINNING OF THE LONG TERM FORECAST...AND WILL PUSH TO SLIGHTLY
ABOVE NORMAL TEMPERATURES AGAIN BY DAY 7.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
WAS FASTER INTRODUCING VALLEY FOG 02Z TO 06Z OVER TYGART AND
GREENBRIER RIVER VALLEYS AND SOUTHERN MOUNTAINS.  SOME OF THIS FOG
OR STRATUS COULD AFFECT THE SOUTHERN PLATEAU INCLUDING THE BKW
VCNTY.

LATE TONIGHT IS TOUGH...CONFIDENCE DROPS TO MEDIUM.  IN THE MOIST
ENVIRONMENT...AND POSSIBLE WEAK MID LEVEL DISTURBANCES...CLOUDS AT
2 TO 4 THSD FT COULD REFORM WITH SOME BATCHES OF CONVECTION EVEN 06Z
TO 12Z MONDAY.  WITH POPS INCREASING BACK INTO THE 20 TO 30 PERCENT
RANGE FOR ANY ONE POINT...COULD NOT INSERT CONVECTION INTO A
SPECIFIC TAF.  PLAYED THE MIDDLE OF THE ROAD ON FOG...MOSTLY 2 TO 4
MILES IN THE WESTERN LOWLANDS.

WITH COLD FRONT NOT ENTERING SOUTHEAST OHIO UNTIL MONDAY
EVENING...TIMING ANY CLUSTERS OF DAYTIME CONVECTION WAS ALSO TOUGH.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z TUESDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: FOG DEVELOPMENT AND DENSITY 06Z TO 12Z MONDAY
TOUGH TO FIGURE DUE TO CLOUD COVER AND CHANCE OF CONVECTION
REFORMING.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                                                            MON 09/02/13
UTC 1HRLY       00   01   02   03   04   05   06   07   08   09   10   11
EDT 1HRLY       20   21   22   23   00   01   02   03   04   05   06   07
CRW CONSISTENCY  H    H    H    H    H    M    H    H    H    H    L    L
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
BKW CONSISTENCY  H    H    H    H    M    M    M    M    H    H    H    H
EKN CONSISTENCY  H    M    M    M    H    L    M    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L

AFTER 00Z TUESDAY...
LINGERING CONVECTION NEAR COLD FRONT MONDAY EVENING MAY CAUSE IFR
CONDITIONS.  IFR FOG POSSIBLE TUESDAY AND WEDNESDAY MORNINGS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JMV/26
NEAR TERM...KTB
SHORT TERM...26
LONG TERM...26
AVIATION...KTB











AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 128 AM EDT SAT AUG 31 2013

.SYNOPSIS...
LOW PRESSURE MOVING ACROSS THE CENTRAL GREAT LAKES WILL DRAG A
COLD FRONT ACROSS THE AREA LATE TONIGHT AND SATURDAY. THE FRONT
WILL STALL ACROSS CENTRAL OHIO SATURDAY NIGHT. A STRONGER COLD
FRONT WILL FOLLOW ON MONDAY USHERING COOLER AIR FOR MID WEEK.

&&

.NEAR TERM /UNTIL 7 AM THIS MORNING/...
THE UPPER LEVEL TROUGH CONTINUES TO MOVE TOWARD NORTHERN OHIO AND
NW PA. THIS UPPER LEVEL SUPPORT COMBINED WITH THE WEAK COLD FRONT
AND OUTFLOW BOUNDARIES HAS BEEN ENOUGH TO KEEP THE THUNDERSTORMS
GOING ACROSS SOUTHERN ONTARIO INTO MICHIGAN. THE CURRENT INCREASE
IN THE COVERAGE IS LIKELY CAUSED BY THE WARM ADVECTION AT 850 MB.
SO WE MAY SEE AN INCREASE OVER THE NEXT COUPLE HOURS ACROSS
SOUTHERN MICHIGAN INTO NW OHIO. STILL DONT BELIEVE IT WILL BE MORE
THAN SCATTERED COVERAGE AT THIS POINT.

PREVIOUS DISCUSSION...
FOR THE EARLY EVENING WILL HAVE SLIGHT CHANCE POPS NW RN PA. RADAR
HAS CONTINUED TO SHOW SMALL RAIN SHOWERS IMPACTING ERIE COUNTY FAR
NORTHEAST AND THIS COULD CONTINUE INTO THE EVENING. MOST AREAS
WILL REMAIN DRY HOWEVER. ELSEWHERE EXPECT PARTLY CLOUDY SKIES
THROUGH THE EVENING. OVERNIGHT A COLD FRONT TO OUR NORTH WILL
CONTINUE DROPPING SOUTH TOWARD THE AREA. CONVECTION IS OCCURRING
ON THE LINE WITH ONE DEVELOPING CLUSTER IN SERN WI WITH A BROKEN
LINE ACROSS NORTHERN LOWER MI. HRRR BRINGS THE WI CLUSTER INTO NRN
INDIANA BY 03Z WHILE THE ACTIVITY ACROSS NRN LOWER MI WEAKENS AND
BECOMES INCREASINGLY ISOLATED IN SERN LOWER MI AND ONTARIO JUST
NORTH OF THE LAKE. WILL BRING CHANCE POPS TO NW RN OHIO AND THE
LAKE MAINLY AFTER MIDNIGHT WITH POPS INCREASING TO CHANCE ACROSS
THE REMAINDER OF THE AREA TIER BETWEEN 06Z AND 12Z. FOLLOWED SREF
TIMING BUT GUIDANCE POPS WERE MUCH HIGHER THAN THE GFS MOS SO DID
SCALE BACK TOWARD THE GFS MOS CHANCE POPS. TEMPS AGAIN MILD WITH
LOWS IN THE UPPER 60S.

&&

.SHORT TERM /7 AM THIS MORNING THROUGH MONDAY NIGHT/...
WILL CONTINUE WITH CHANCE POPS THROUGH THE DAY AS THE WEAK COLD
FRONT SLOWLY SAGS SOUTH THROUGH THE AREA. BEST CHANCE LIKELY
SOUTHEAST COUNTIES GIVEN THAT THE FRONT WILL BE MOVING INTO THAT
AREA DURING THE AFTERNOON HOURS. SATURDAY NIGHT THE FRONT WILL
LIKELY STALL JUST TO OUR SOUTH AS LOW PRESSURE MOVES ALONG IT WEST
OF THE AREA. BOTH THE NAM AND GFS INDICATE MOISTURE INCREASES
AGAIN FROM THE SOUTHWEST AS THE FRONT WAFFLES BACK TOWARD OR INTO
THE AREA. BROUGHT CHANCE POPS BACK AFTER MIDNIGHT WEST AFTER
HAVING DRIED IT OUT FOR THE EVENING. SUNDAY THROUGH MONDAY MODELS
CONTINUE TO INCREASE MOISTURE ACROSS THE AREA AHEAD OF ANOTHER
APPROACHING COLD FRONT. THE FRONT WILL MOVE THROUGH THE AREA
MONDAY AND WITH FORECAST CAPES FROM 2-3000J/KG FOR THE AFTERNOON
TSTMS COULD GET STRONG. WILL CONTINUE TO WATCH SEVERE POTENTIAL
BUT FOR NOW WILL HAVE HIGH CHANCE TO LIKELY POPS THROUGH THE DAY.
TUESDAY NIGHT WILL ALLOW WESTERN COUNTIES TO DRY OUT AS HIGH
PRESSURE AND DRIER AIR MOVE IN. WILL KEEP CHANCE POPS FOR SHOWERS
IN THE EAST GIVEN THE MOISTURE AND THE FACT THAT COOLER AIR WILL
BE MOVING ACROSS THE LAKE. HIGHS ABOVE NORMAL MUCH OF THE PERIOD.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL BUILD OVER THE AREA ON TUESDAY AS THE UPPER LEVEL
TROUGH AXIS SHIFTS EAST OF THE GREAT LAKES. THE AIRMASS WILL FEEL
NOTICEABLY DIFFERENT WITH DECREASING HUMIDITY AND TEMPERATURES
DROPPING BACK TO BELOW NORMAL VALUES. EXPECTING SCT-BKN CLOUDS WITH
THE GREATEST COVERAGE IN NE OH/NW PA. HIGHS WILL TOP OUT IN THE LOW
70S IN OHIO...STRUGGLING TO GET OUT OF THE 60S IN NW PA.

HIGH PRESSURE WILL BUILD SOUTHEAST ACROSS THE REGION ON
WEDNESDAY...SHIFTING TO THE OHIO VALLEY ON THURSDAY. TEMPERATURES
WILL REBOUND SEVERAL DEGREES WITH MOSTLY SUNNY SKIES AND GOOD
INSULATION ON WEDNESDAY.

12Z MODEL SUITE HAS COME INTO BETTER AGREEMENT WITH THE HANDLING OF
THE NEXT FRONT ON THURSDAY. THE 00Z ECMWF WHICH WAS FASTER AND
STRONGER WITH THE NEXT COLD FRONT HAS SLOWED DOWN WITH THE 12Z RUN
AND TRENDED TOWARDS A WEAKER FRONT. THIS IS CLOSER TO THE SOLUTION
OFFERED BY THE GFS SO WILL LEAN THE FORECAST TOWARDS JUST ANOTHER
MODEST DROP IN TEMPERATURES TOWARDS THE END OF THE WEEK INSTEAD OF
THE COLDER SOLUTION.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SCATTERED TSRA WILL PUSH OF THE AREA OVERNIGHT AHEAD OF
APPROACHING COLD FRONT. FRONT CURRENTLY STRETCHES FROM LOW
PRESSURE OVER LAKE ONTARIO INTO EXTREME NW OH. MODELS CONTINUE TO
PUSH FRONT SOUTH OF THE LAKESHORE COUNTIES BY LATE MORNING EARLY
AFTERNOON. EXPECT WIDESPREAD MVFR PATCHY IFR WITH THE FRONT. EXPECT
TSRA TO REDEVELOP THIS AFTERNOON SOUTH OF FRONT...MAINLY SOUTH OF
A YNG TO FDY LINE.

OUTLOOK...NON VFR LIKELY INLAND LOCATIONS EACH MORNING IN PATCHY
FOG. NON VFR IN SCATTERED SHOWERS/THUNDERSTORMS SATURDAY THROUGH
MONDAY.

&&

.MARINE...
A LIGHT SOUTHWESTERLY FLOW WITH SOME DEGREE OF A LAKE BREEZE ON THE
EASTERN HALF OF THE LAKE IS IN PLACE TODAY. WINDS WILL INCREASE TO
10 TO 15 KNOTS AHEAD OF A COLD FRONT THAT WILL PUSH SOUTH ACROSS THE
LAKE LATE TONIGHT INTO SATURDAY MORNING. SCATTERED SHOWERS AND
THUNDERSTORMS ARE ALSO EXPECTED AHEAD OF THE FRONT. WINDS WILL SHIFT
TO THE NORTHWEST BEHIND THE FRONT ON SATURDAY BUT ARE NOT EXPECTED
TO BE MORE THAN 5 TO 15 KNOTS AS THE FRONT STALLS OVER CENTRAL
OHIO.

WIND WILL SHIFT AROUND TO THE SOUTH ON SUNDAY AS A WARM FRONT PUSHES
BACK NORTH OVER THE LAKE. THERE WILL BE A CHANCE OF THUNDERSTORMS
SUNDAY...INCREASING SUNDAY NIGHT INTO MONDAY AS LOW PRESSURE
APPROACHES THE GREAT LAKES FROM THE WEST. THIS SYSTEM WILL PULL A
STRONGER COLD FRONT ACROSS THE LAKE ON MONDAY WITH NORTHWESTERLY
WINDS INCREASING TO 10 TO 20 KNOTS DURING THE AFTERNOON. THE
NORTHWESTERLY FLOW WILL LEAD TO WAVES BUILDING TO 2 TO 4 FEET ON
MONDAY NIGHT AND TUESDAY.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...TK
NEAR TERM...TK/MULLEN
SHORT TERM...TK
LONG TERM...KEC
AVIATION...DJB
MARINE...KEC







AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 300 AM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE SOUTHEAST OF THE REGION
THIS MORNING...WHILE A SLOW MOVING COLD FRONT SETTLES INTO THE
REGION FOR THE REMAINDER OF THE HOLIDAY WEEKEND. A SECOND COLD
FRONT IS EXPECTED TO FINALLY CLEAR THINGS OUT SOMETIME
TUESDAY...FOLLOWED BY SEVERAL DAYS OF COOLER AND DRIER CONDITIONS.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
MUGGY AIR IN PLACE AND ADVANCING CLOUD COVER WILL KEEP OVERNIGHT TEMPS
VERY WARM FOR THE LAST DAY OF AUGUST. SHOWERS WEAKENING RAPIDLY AS
FCST AND SHOULD CONTINUE TO DO SO. RECENT RUC RUNS DO ALLOW FOR
SOME RAIN TO ROLL ALONG THE NRN MTS OVERNIGHT...BUT CONFIDENCE LOW
AT THIS POINT TO PUT MORE THAN CHC POPS - AND KEEP THEM WELL NORTH
OF I-80 - CONFINED TO MAINLY THE NORTHERN STRIPE OF COS.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SUNDAY/...
A DIFFUSE COLD FRONT IS EXPECTED TO SAG INTO THE REGION AND
BASICALLY STALL OR WASH OUT OVER THE NEXT FEW DAYS. ENSEMBLES SHOW
A RIBBON OF ANOMALOUS PWATS MOVE IN FOR SATURDAY BEFORE SOMEWHAT
DRIER AIR RETURNS FOR SATURDAY NIGHT AND SUNDAY. BOTH THE SREF AND
GEFS SHOW A HIGH PROB OF MEASURABLE RAINS...BUT QPF ON THE ORDER
OF .25" OR LESS LOOKS LIKE THE BEST BET.

SATURDAY WILL BE ANOTHER HUMID AND WARM DAY WITH HIGHS IN THE 80S
JUST ABOUT EVERYWHERE IN CENTRAL PA.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WEAK DISTURBANCE WILL MOVE ACROSS THE REGION SUNDAY.

THE MAIN COLD FRONT WILL MOVE ACROSS LATE MONDAY INTO
EARLY TUE AM.

DID NOT CHANGE A LOT.

DID LOWER POPS SOME FOR SATURDAY NIGHT...AS WE ARE BETWEEN
WEAK SYSTEMS.

PRIOR TO TUE...DID UP TEMPS SOME. TOOK SHOWERS OUT AFT TUE
MORNING...AS SUPPORT FOR ANY ACTIVITY IS LOST.

WED LOOKS DRY.

CHC OF SHOWERS FOR THU...WITH STRONGER FRONT. DID NOT HAVE
THUNDER IN AT THIS POINT...MOISTURE WILL BE LIMITED.

00Z 8/30 EC RUN SHOWS A STRONGER FRONT FOR THU...DID GO COLDER
THAN THE GFS FOR FRIDAY...BUT NOT REAL COLD AT THIS POINT.

WHILE THE UPPER LVL TROUGH SLOWLY LIFTS WESTWARD...STILL THINK
WE ARE IN A A WARM PERIOD OVERALL FOR THE NEXT FEW WEEKS.

ENJOY THE HOLIDAY WEEKEND.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
RADAR TRENDS INDICATE THE BAND OF CONVECTION THAT PUSHED SEWD
ACRS LAKE ERIE /ASSOCD WITH WEAK SFC LOW/FRONTAL BOUNDARY OVER SRN
ONTARIO/ IS RAPIDLY WEAKENING/DISSIPATING AS IT MOVES INLAND OVR
NW PA. BFD COULD SEE A BRIEF -SHRA PRIOR TO 12Z WITH NO LCL
RESTRICTIONS XPCTD.

SCT-BKN MID AND HIGH CLOUDS WILL SPREAD SEWD INTO THE CENTRAL AND
SERN TAFS THROUGH THE MORNING...AS THE WEAK FRONTAL SYSTEM CROSSES
THE LWR LKS. A LGT SSW SFC WIND AND INC CLOUD COVER WILL KEEP
VISBYS IN THE VFR TO MVFR RANGE...WHICH IS MORE OPTIMISTIC THAN
THE GUIDANCE. THE EXCEPTION MIGHT BE ACROSS SOUTHEAST PA...WHERE
SKIES SHOULD REMAIN MCLEAR AND WINDS MAY BECOME CALM. THE LATEST
IR SAT LOOP IS ALREADY DETECTING FOG/ST FORMING IN THIS AREA.
STILL THINK LNS HAS THE BEST SHOT AT A BRIEF PERIOD OF IFR AROUND
DAYBREAK. RADAR NOW SHOWING SOME ISOLD SHOWERS DEVELOPING ENE OF
IPT.

THE SFC LOW OVER SRN ONTARIO WILL MOVE EWD INTO UPSTATE NY
TODAY...WITH ITS TRAILING FRONTAL SYSTEM PUSHING INTO CNTRL PA.
THE FRONT SHOULD TRIGGER SCT SHOWERS AND TSTMS WITH LCL IMPACTS
PSBL DURING THE AFTN AND EVE. KEPT VCSH FOR NOW BUT MAY CHANGE TO
VCTS WITH THE NEXT SCHEDULED ISSUANCE. CONVECTION SHOULD DISSOLVE
IN THE 00-03Z TIMEFRAME AS THE BLYR COOLS AND STABILIZES. A BAND
OF MVFR CIGS SEEMS PROBABLE BEHIND THE FRONT TONIGHT OVER NW PA.

OUTLOOK...
SUN...AM LOW CIGS/FOG. SCT PM TSRA IMPACTS.
MON...AM FOG. SCT PM TSRA IMPACTS. FROPA.
TUE...MVFR CIGS WEST/VFR CNTRL AND EAST.
WED...AM FOG PSBL WEST AND CNTRL. NO SIG WX.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...STEINBUGL







AREA FORECAST DISCUSSION

NWS STATE COLLEGE PA

 140 AM EDT SAT AUG 31 2013

.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFF TO THE SOUTHEAST OF THE REGION
THIS MORNING...WHILE A SLOW MOVING COLD FRONT SETTLES INTO THE
REGION FOR THE REMAINDER OF THE HOLIDAY WEEKEND. A SECOND COLD
FRONT IS EXPECTED TO FINALLY CLEAR THINGS OUT SOMETIME
TUESDAY...FOLLOWED BY SEVERAL DAYS OF COOLER AND DRIER CONDITIONS.

&&

.NEAR TERM /UNTIL 8 AM THIS MORNING/...
MUGGY AIR IN PLACE AND ADVANCING CLOUD COVER WILL KEEP OVERNIGHT TEMPS
VERY WARM FOR THE LAST DAY OF AUGUST. SHOWERS WEAKENING RAPIDLY AS
FCST AND SHOULD CONTINUE TO DO SO. RECENT RUC RUNS DO ALLOW FOR
SOME RAIN TO ROLL ALONG THE NRN MTS OVERNIGHT...BUT CONFIDENCE LOW
AT THIS POINT TO PUT MORE THAN CHC POPS - AND KEEP THEM WELL NORTH
OF I-80 - CONFINED TO MAINLY THE NORTHERN STRIPE OF COS.

&&

.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SUNDAY/...
A DIFFUSE COLD FRONT IS EXPECTED TO SAG INTO THE REGION AND
BASICALLY STALL OR WASH OUT OVER THE NEXT FEW DAYS. ENSEMBLES SHOW
A RIBBON OF ANOMALOUS PWATS MOVE IN FOR SATURDAY BEFORE SOMEWHAT
DRIER AIR RETURNS FOR SATURDAY NIGHT AND SUNDAY. BOTH THE SREF AND
GEFS SHOW A HIGH PROB OF MEASURABLE RAINS...BUT QPF ON THE ORDER
OF .25" OR LESS LOOKS LIKE THE BEST BET.

SATURDAY WILL BE ANOTHER HUMID AND WARM DAY WITH HIGHS IN THE 80S
JUST ABOUT EVERYWHERE IN CENTRAL PA.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WEAK DISTURBANCE WILL MOVE ACROSS THE REGION SUNDAY.

THE MAIN COLD FRONT WILL MOVE ACROSS LATE MONDAY INTO
EARLY TUE AM.

DID NOT CHANGE A LOT.

DID LOWER POPS SOME FOR SATURDAY NIGHT...AS WE ARE BETWEEN
WEAK SYSTEMS.

PRIOR TO TUE...DID UP TEMPS SOME. TOOK SHOWERS OUT AFT TUE
MORNING...AS SUPPORT FOR ANY ACTIVITY IS LOST.

WED LOOKS DRY.

CHC OF SHOWERS FOR THU...WITH STRONGER FRONT. DID NOT HAVE
THUNDER IN AT THIS POINT...MOISTURE WILL BE LIMITED.

00Z 8/30 EC RUN SHOWS A STRONGER FRONT FOR THU...DID GO COLDER
THAN THE GFS FOR FRIDAY...BUT NOT REAL COLD AT THIS POINT.

WHILE THE UPPER LVL TROUGH SLOWLY LIFTS WESTWARD...STILL THINK
WE ARE IN A A WARM PERIOD OVERALL FOR THE NEXT FEW WEEKS.

ENJOY THE HOLIDAY WEEKEND.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
BAND OF SHOWERS OVR LK ERIE IS DESTINED TO DISSIPATE AS IT
PUSHES INTO NW PA OVERNIGHT...AS AIR MASS COOLS AND STABILIZES. BIGGER
AVIATION CONCERN IS THE POSSIBILITY OF FOG EARLY SAT AM ACROSS SE
PA. A LIGHT SW BREEZE AND INCREASING CLOUD COVER SHOULD PRECLUDE
SIG VSBY RESTRICTIONS FROM RADIATION FOG OVER MOST OF CENTRAL
PA...DESPITE THE MORE PESSIMISTIC MOS GUIDANCE. THE EXCEPTION
MIGHT BE ACROSS SOUTHEAST PA...WHERE SKIES SHOULD REMAIN MCLEAR
AND WINDS MAY BECOME CALM. BOTH SREF AND MDL SFC RH FIELDS SUGGEST
IFR VSBYS ARE POSSIBLE ARND DAWN AT LNS AND TO A LESSER DEGREE
MDT.

A COLD FRONT WILL PUSH SOUTHEAST INTO THE REGION ON
SATURDAY...LIKELY PRODUCING ISOLD TSRA IMPACTS DURING THE AFTN
AND EVENING HOURS.

OUTLOOK...
SUN...AM LOW CIGS/FOG...ESP W MTNS. SCT PM TSRA IMPACTS POSS...ESP
SOUTH.
MON...AM FOG POSS. SCT PM TSRA IMPACTS POSS.
TUE-WED...NO SIG WX EXPECTED.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO/LA CORTE
NEAR TERM...DANGELO
SHORT TERM...LA CORTE
LONG TERM...MARTIN
AVIATION...FITZGERALD








AREA FORECAST DISCUSSION...UPDATED

NWS NASHVILLE TN

 933 PM CDT SUN SEP 1 2013

.UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT ISO TO SCT
SHWRS/TSTMS COMING INTO WRN PORTIONS OF THE MID STATE THIS EVENING.
HAVE UPDATED SKY CONDITIONS TO MOCLDY AND WITH CURRENT TEMP TRENDS...
HAVE LOWERED LOWS BY A DEGREE OR SO. STILL TRICKY FORECAST THRU
TONIGHT AS ATM LOW LEVELS REMAIN RATHER HIGH IN ATM MOISTURE
CONTENT WITH CONTINUED UNSTABLE CONDITIONS...SUBTLE SHORTWAVES IN
UPPER LEVEL PREDOMINATE NWLY FLOW ALOFT INTERACTING...AND SFC
FRONT APPROACHING FROM THE NW BY THE MORNING HRS. HAVE INITIALLY
LEANED TOWARD THE LATEST HRRR MODEL RUNS IN SHOWING SOME ADDITIONAL
DEVELOPMENT FROM THE SW...SPREADING ACROSS THE MID STATE AFTER MIDNIGHT
TONIGHT AS THIS AREA PRESENTLY LOOKS TO HAVE THE BEST OVERALL INSTABILITY
AND MOISTURE POTENTIAL TO SUPPORT SHWR/TSTM DEVELOPMENT.
&&

.PREV DISCUSSION.../ISSUED 623 PM CDT SUN SEP 1 2013/

UPDATE...FOR AVIATION.

AVIATION...
00Z TAFS...MAIN CHALLENGE CONTINUES TO BE FORECAST FOR TIMING AND
COVERAGE OF TSRA. QUIET CONDITIONS ARE EXPECTED THROUGH THE NEXT
FEW HOURS. AFTER 01/05Z...SOME AREAS OF MVFR BR WILL DEVELOP AND
THE CHANCE FOR TSRA WILL INCREASE...WITH POSSIBLE ONGOING SCT TSRA
COMING DOWN FROM KY INTO MID TN. ADDITIONAL SCT TSRA WILL
CONTINUE THROUGH MIDDAY MONDAY AHEAD OF THE FRONT. ANY TSRA COULD
PRODUCE HEAVY RAIN AND LOCAL GUSTY WINDS...WHILE VFR CONDITIONS
WILL PREVAIL OUTSIDE THE STORMS. DRIER AND MORE STABLE AIR WILL BE
COMING IN AT THE END OF THE TAF PERIOD MONDAY EVENING.

13

PREV DISCUSSION... /ISSUED 504 PM CDT SUN SEP 1 2013/

UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT AND
EXPECTED EVENING CONDITIONS FOR TONIGHT WITH ONLY A SLIGHT CHANCE
TO CHANCE OF SHWRS/TSTMS ACROSS SW PORTIONS...OTHERWISE PTCLDY SKIES
EXPECTED ACROSS MID STATE. WITH SFC FRONT AND UPPER LEVEL TROUGH AXIS
APPROACHING OVERNIGHT...WENT WITH INCREASING CHANCES OF SHWRS/TSTMS
AFTER MIDNIGHT ACROSS MID STATE.

31

PREV DISCUSSION.../ISSUED 135 PM CDT SUN SEP 1 2013/

DISCUSSION...CLOUDS AND SCATTERED SHOWERS CONTINUE TO AFFECT
PARTS OF MIDDLE TENNESSEE, WITH MOST TEMPERATURES RUNNING WELL
BELOW FORECAST HIGHS. STILL EXPECT SOME SUNSHINE LATER IN THE
AFTERNOON THAT WILL CLOSE THE GAP SOMEWHAT, BUT CLOUDS HAVE REALLY
THROWN A WRENCH INTO TODAY`S FORECAST. AT ANY RATE, THE MAIN
TROUGH AXIS WILL INCH CLOSER TO MIDDLE TENNESSEE OVERNIGHT, WITH
SCATTERED SHOWERS AND STORMS OCCURRING MAINLY DURING THE 06Z-12Z
PERIOD. LOOK FOR SCATTERED ACTIVITY TO CONTINUE TOMORROW AS THE
SURFACE FRONT ENTERS THE MID STATE DURING THE AFTERNOON.
PRECIPITATION WILL END FROM NW TO SE TOMORROW NIGHT AS WE GET A
BIG AIR MASS CHANCE, WITH SIGNIFICANTLY DRIER, COOLER AIR EVIDENT
BY TUESDAY. EXPECT DRY WEATHER FROM TUESDAY AT LEAST THROUGH
SUNDAY, WITH TEMPERATURES GRADUALLY WARMING THROUGHOUT THE WEEK AS
HIGH PRESSURE DOMINATES OUR WEATHER FOR A PROLONGED STRETCH. AT
THIS TIME, THE SPC CONTINUES TO FORECAST ONLY GENERAL
THUNDERSTORMS FOR MIDDLE TENNESSEE THROUGH TOMORROW NIGHT.

ROSE

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
31






AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 805 PM EDT SUN SEP 1 2013

.SYNOPSIS...
UPPER AIR DISTURBANCES WILL MOVE EAST ACROSS THE AREA THIS EVENING
AND AGAIN MONDAY WITH A COLD FRONT MOVING THROUGH BY TUESDAY.
THIS FRONT WILL BRING A DRIER AIRMASS TO THE REGION THROUGH THE
END OF NEXT WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 250 PM EDT SUNDAY...

BANDS OF SHRA/TSRA CONTINUE TO SPREAD EAST ACROSS THE REGION
LATE THIS AFTERNOON AHEAD OF A WEAK VORT LOBE THAT LOOKS TO SWING
ACROSS THE MOUNTAINS BY THIS EVENING BEFORE EXITING TO THE EAST
OVERNIGHT. BEST INSTABILITY REMAINS ALONG/EAST OF THE BLUE RIDGE
WHERE SUPPORTED BY HIGHER LOW LEVEL THETA-E AND WEAK CONVERGENCE.
LATEST HRRR AND SIMILAR NAM SOLUTIONS EVENTUALLY PUSH BEST
COVERAGE OF STORMS INTO THE NE CWA BY THIS EVENING FOLLOWED BY
DECENT DRYING BEHIND THE WAVE OVERNIGHT. HOWEVER WITH POTENTIAL
FOR SEVERAL BANDS OF SHRA INTO THE EVENING WILL HAVE THE HIGHER
LIKELY POPS BLUE RIDGE WEST EARLY WITH MAINLY HIGH CHANCES TO THE
EAST. CUT PRECIP BACK OVERNIGHT AS THE AREA SLIPS IN BETWEEN
IMPULSES WITH ONLY ISOLATED COVERAGE LIKELY AT THIS POINT. HOWEVER
SHOULD BE PLENTY OF FOG AROUND AS CLOUDS CLEAR SOME LATER ON AND
TEMPS FALL BACK INTO THE 60S MOST SPOTS.

5H TROF WILL SLOWLY SAG INTO THE AREA ON MONDAY WITH THE
ASSOCIATED SURFACE COLD FRONT STILL WEST OF THE MOUNTAINS
THROUGH LATE IN THE DAY. THIS COMBO WITH MORE WESTERLY FLOW TO
INIT SHOULD LIMIT SHRA EARLY ON FOLLOWED BY INCREASING AFTERNOON
COVERAGE FAR WEST...AND ALONG THE BLUE RIDGE AS THE LOW LEVEL FLOW
SLOWLY BACKS. MODELS GIVEN MORE INSOLATION AND LESS EARLY
SHRA...NOW SHOWING MORE INSTABILITY ALTHOUGH WIND FIELDS ALOFT
LOOK RATHER WEAK. THUS HAVE CUT BACK ON POPS DURING THE MORNING TO
LOW CHANCE OR SLIGHTS...WITH A GRADUAL INCREASE TO LIKELYS OVER
THE FAR WEST LATER IN THE AFTERNOON. MAY SEE THE PIEDMONT ACTUALLY
GO DRY FOR THE MOST PART UNTIL LATE BUT LEFT CHANCE COVERAGE THERE
FOR NOW GIVEN HEATING. WILL BE A HOT LABOR DAY WITH 85H TEMPS NEAR
+20C WHICH SHOULD ALLOW MOST OUTSIDE THE HIGHER RIDGES TO TOP 80
WITH PERHAPS LOW 90S EAST PENDING EARLY CLOUDS AND LATER TSRA.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 330 PM EDT SUNDAY...

COLD FRONT MOVES THROUGH MONDAY NIGHT BUT WITH A FEW DISTURBANCES
BEHIND IT AND REMAINING MOISTURE...STILL A GOOD CHANCE OF SHOWERS
FOR THE FIRST HALF OF THE NIGHT...ESPECIALLY IN THE WEST.
IMPRESSIVE PUNCH OF DRIER AIR ARRIVES ON DOWNSLOPING WINDS AS
SKIES BEGIN TO CLEAR INTO TUESDAY MORNING. ALTHOUGH THERE IS SOME
POSITIVE ENERGY IN THE SOUNDING TUESDAY AFTERNOON...APPEARS TO BE
JUST TOO MUCH DRY AIR ABOVE H85 TO GET ANY STORMS GOING. MOISTURE
HANGS A BIT CLOSER TO THE FRONT ACROSS THE SOUTHSIDE SO LEFT SOME
POPS THERE. FOR SOME REASON...THE NAM SOUNDINGS ARE FAR TOO
AGGRESSIVE WITH CAPE ON TUESDAY...MOST LIKELY BECAUSE DEWPOINTS
FROM THE NAM AND THE MET MOS ARE 6-8F WARMER THAN THE
GFS/MAV/ECMWF. WITH LOW TO MID 50S DEWPOINTS ARRIVING LATE
TUESDAY...SOME OF THE COLDEST SPOTS OF SE WEST VA AND EXTREME SW
VA MAY TOUCH THE UPPER 40S TUESDAY NIGHT. AT THIS POINT...COOL
AND DRY HIGH PRESSURE WILL RULE THE REST OF THE SHORT TERM WITH
ONLY PASSING HIGH CLOUDS. WEDNESDAY NIGHT HAS THE POTENTIAL TO BE
JUST AS CHILLY AS TUESDAY NIGHT...ALTHOUGH MORE HIGH CLOUDS MAY
KEEP TEMPS UP A TAD. FOR HIGH TEMPS WEDNESDAY...THE ONLY PLACE 80S
WILL BE FOUND WILL BE THE LOWEST ELEVATIONS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 330 PM EDT SUNDAY...

THE DRY PATTERN CONTINUES AS TEMPS SLOWLY WARM...ALTHOUGH NOT AS
FAST AS WHAT THE OPERATIONAL GFS HAS. H85 TEMPS FROM THAT MODEL
ARE SEVERAL DEGREES WARMER THAN THE ECMWF. AGREE WITH THE SLOWER
WARMUP BUT NOT AS COOL AS THE ECMWF MOS. NONETHELESS...BOTH
MODELS ARE MOSTLY DRY...UNTIL AN EASTERN TROUGH ONCE AGAIN
DEEPENS. SUBTLE INDICATIONS IN THE MASS FIELDS FROM THE ECMWF THAT
A BACKDOOR FRONT MAY CROSS SATURDAY OR SUNDAY. WITH THAT
SAID...THERE STILL REALLY ISN`T MUCH QPF TO BE FOUND ON EITHER
MODEL THROUGH DAY 7.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 750 PM EDT SUNDAY...

SECOND IN A SERIES OF NW FLOW SHORT WAVES EXITING THE EASTERN SIDE
OF THE CWA AT THIS HOUR. MODELS SHOW A DRY SLOT...WEAK SHORT WAVE
UPPER RIDGE TO TRAVERSE THE AREA OVERNIGHT. ONCE SHRA DISSIPATE
ACROSS THE WESTERN AREAS AND SHRA/TSRA DISSIPATE ACROSS THE
EASTERN AREAS WITH LOSS OF DAYTIME HEATING...EXPECT A MAINLY PCPN
FREE OVERNIGHT PERIOD. DESPITE EXTENSIVE LINGERING MID/HIGH
CLOUDS...THIS...ALONG WITH THE MOIST GROUND AND LATE DAY RAIN
-SHRA IN MANY AREAS...WILL LEAVE MUCH OF THE CWA WITH GOOD CONDITIONS
FOR RADIATIONAL FOG DEVELOPMENT OVERNIGHT. AS IN PREVIOUS
NIGHTS...EXPECT LWB/BCB/LYH TO FOG IN PRETTY QUICKLY WITH IFR-LIFR
CONDITIONS EXPECTED MUCH OF THE NIGHT. LWB WILL LIKELY BE NEAR 0SM
FG MUCH OF THE NIGHT AS HAS BEEN COMMON RECENTLY. DAN SHOULD ALSO
SEE IFR-LIFR BR/FG BEFORE THE NIGHT IS OVER AS WELL. ROA SHOULD
REMAIN MOSTLY FOG FREE. FOR BLF...UPSLOPE WSW FLOW SHOULD PROMOTE
IFR CIGS MUCH OF THE NIGHT ALONG WITH MVFR VSBYS IN BR. LWB WILL
SEE MVFR CIGS INITIALLY...BUT AS FOG DEVELOPS...VLIFR.
OTHERWISE...IN FOG AREAS EXPECT MOSTLY LIFR VV CIGS TO DEVELOP
COINCIDENT WITH FOG...OTHERWISE MOSTLY VFR CIGS...MVFR AT WORSE.
WINDS WSW 5KTS OR LESS OVERNIGHT. THE NEXT UPSTREAM SHORT AND
APPROACHING MAIN UPPER TROUGH WILL BEGIN TO AFFECT THE AREA SUN.
TIMING AND EXPECTED PRE-FRONTAL HEATING SHOULD PROMOTE TSRA
DEVELOPMENT...ESPECIALLY SW VA/NW NC BY 18Z AND BEYOND...SOME
STRONG TO SEVERE WITH DAMAGING WIND THE MAIN THREAT. MVFR OR WORSE
CIGS/VSBYS WILL ACCOMPANY THIS ACTIVITY. OTHERWISE...EXPECT MOSTLY
VFR-MVFR VSBYS AND VFR-MVFR CIGS AFT 14Z SUN.

EXTENDED AVIATION DISCUSSION...
TRUE FRONT AND MAIN UPPER THROUGH WILL MOVE EAST OF THE AREA TUE.
THUS...EXPECTING MOSTLY VFR CONDITIONS AS MUCH DRIER AIR ADVECTS
INTO THE AREA FROM THE NORTHWEST. PROXIMITY OF UPPER TROUGH AND
LINGERING MOISTURE ACROSS SE SECTIONS MAY SUPPORT A -SHRA/TSRA
THREAT FOR DAN/LYH YET TUE...BUT OTHERWISE NONE EXPECTED AGAIN
THROUGH FRI. NW WINDS OF 8-12KTS WITH LOW END GUSTS CAN BE
EXPECTED TUE BEHIND THE FRONT...OTHERWISE AVIATION CONDITIONS
SHOULD BE QUITE GOOD TUE-FRI OUTSIDE EARLY MORNING FOG AT SITES
SUCH AS LWB/BCB/LYH.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/RCS/WP
NEAR TERM...JH
SHORT TERM...KM
LONG TERM...KM
AVIATION...JH/RAB




AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 605 PM CDT SUN SEP 1 2013

.SHORT TERM...(TONIGHT THROUGH LABOR DAY)
ISSUED AT 215 PM CDT SUN SEP 1 2013

MAIN QUESTION TONIGHT IS CLOUD COVER. CURRENT CLOUD DECK HAS A
COUPLE ELEMENTS TO IT - MAIN MASS IN THE WRAP AROUND REGION WEST OF
AN EASTWARD MOVING SFC LOW...AND DIURNALLY DRIVEN CLOUDS ON THE
SOUTHERN FRINGES OF THIS MASS. THE DIURNAL CLOUD WILL DISSIPATE WITH
SUNDOWN...WHILE THE CLOUDS WITH THE LOW WILL MOVE EAST. HOWEVER...RH
FIELDS POINT TO A SAG SOUTH/SOUTHWEST OF SOME LOW LEVEL SATURATION
AS 925 MB WINDS KICK UP FROM THE NORTH/NORTHEAST AT 20 MPH LATER
TONIGHT. 01.09Z SREF PROBABILITIES ALSO POINT TO A HIGHER LIKELIHOOD
OF LOW CIGS ADVANCING SOUTHEAST...HIGHEST DOWN TO I-94...BUT COULD
WORK TO THE MISSISSIPPI RIVER. WILL INCREASE CLOUDS TONIGHT/EARLY
MONDAY BASED ON THESE TRENDS.

CLOUDS THAT MOVE IN SHOULD EXIT ON MONDAY AS HIGH PRESSURE STARTS TO
BUILD IN FROM THE WEST. THEY MAY NOT BE THAT QUICK TO EXIT NORTH
CENTRAL WI...WHICH COULD BE STUCK IN CLOUDS FOR A BETTER PART OF THE
DAYLIGHT HOURS. A COLD FRONT THAT PASSED ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY TODAY WILL RESULT IN SOME MUCH
COOLER...DRIER AIR WORKING IN FOR LABOR DAY. SREF AND ECMWF 850 TEMP
ANOMALIES ARE AROUND -1 FOR MONDAY. HIGHS COULD STRUGGLE TO REACH 70
IN MANY LOCATIONS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 215 PM CDT SUN SEP 1 2013

HIGH PRESSURE BUILDS OVERHEAD MONDAY NIGHT...CENTERED OVER THE LOCAL
AREA BY 12Z TUE. LOOKS LIKE A DECENT SETUP FOR FOG IN AREA RIVER
VALLEYS. NAM BUFKIT SOUNDINGS FAVOR IT A BIT MORE THAN THE GFS...BUT
ALL SUGGEST ITS PROBABLE...IF NOT LIKELY. WITH RAIN HAVING BEEN
SPARSE THE PAST COUPLE WEEKS...NOT CONFIDENT THAT FOG WILL DEVELOP
OUTSIDE OF THE RIVER VALLEYS.

GFS AND ECMWF IN GOOD AGREEMENT WITH AN UPPER LEVEL RIDGE TO THE
WEST...AND NORTHWEST FLOW OVER THE UPPER MISSISSIPPI RIVER VALLEY.
SOMEWHAT INACTIVE FLOW...WITH THE MODELS SUGGESTING THAT ANY
PERTURBATION IN THE FLOW WOULD MOVE SOUTH/NORTH OF THE LOCAL
FORECAST AREA. THUS...A CONTINUATION OF THE DRY CONDITIONS.

FOR THE WEEKEND THE RIDGE IS PROGGED TO SHIFT EASTWARD INTO THE
AREA...BUT COULD FLATTEN OUT AS IT DOES...THANKS TO AN UPPER LEVEL
SHORTWAVE TROUGH DRIVING ACROSS THE NORTHERN PLAINS. THIS TROUGH
SHOWS SOME PROMISE OF PCPN CHANCES FOR SUNDAY-MONDAY.

TEMPERATURES WILL GRADUALLY WARM THROUGH THE WEEK...AND COULD BE
FAIRLY WARM FOR THE FIRST WEEKEND OF SEPTEMBER AS WINDS BECOME MORE
SOUTHERLY/RIDGE WORKS IN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 605 PM CDT SUN SEP 1 2013

THE MAIN CONCERN THROUGH THE PERIOD IS WITH CLOUD COVER. SURFACE
LOW EAST OF LAKE SUPERIOR IS MAINTAINING A LOW LEVEL CYCLONIC
FLOW OVER THE REGION. LARGE AREA OF CLOUDS ON THE BACK SIDE OF THE
LOW FROM WESTERN ONTARIO INTO THE REGION. SATELLITE TRENDS SHOW
SOME THINNING/BREAKING OF THE CLOUD DECK OCCURRING OVER CENTRAL
MINNESOTA INTO NORTHERN WISCONSIN. IF THIS CONTINUES TO
OCCUR...EXPECT THE CURRENT CLOUDS TO DISSIPATE/SCATTER OUT BY MID
EVENING. BOTH THE 01.18Z NAM AND 01.21Z RAP THEN SHOW THE MOISTURE
AND CLOUDS OVER NORTHEAST MINNESOTA/NORTHERN WISCONSIN/WESTERN
ONTARIO SPREADING OVER THE AREA AFTER 06Z. HAVE GONE ALONG WITH THESE
TRENDS BRINGING IN MVFR CEILINGS OVERNIGHT WITH THESE THEN MIXING
OUT/MOVING OFF TO THE EAST DURING THE MORNING AS THE CYCLONIC FLOW
RELAXES WITH HIGH PRESSURE BUILDING IN FROM THE WEST.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 325 PM CDT SAT AUG 31 2013

.SHORT TERM...(TONIGHT THROUGH SUNDAY NIGHT)
ISSUED AT 325 PM CDT SAT AUG 31 2013

MAIN FORECAST CONCERNS THIS PACKAGE...SHRA/TSRA CHANCES TONIGHT INTO
SUN...TEMPERATURES.

AT 18Z...WEAK HIGH PRESSURE WAS CENTERED OVER NORTHERN LOWER MI WITH
RIDGING SOUTHWEST INTO NORTHERN IA. LOW PRESSURE WAS OVER SOUTHEAST
MANITOBA WITH A TRAILING COLD FRONT INTO THE EASTERN DAKOTAS.
CONVECTION SLOWLY DEVELOPING ALONG THIS FRONT EARLY THIS AFTERNOON.
SHALLOW LOWER LEVEL MOISTURE/STRATO-CU TRAPPED UNDER AN INVERSION
NEAR 900MB CONTINUED TO PLAGUE SOUTHERN WI/SOUTHEAST MN/EASTERN IA...
BUT CONTINUED TO SLOWLY DISSIPATING WITH DIURNAL WARMING/MIXING AS OF
MID-DAY. MORE COMFORTABLE DAY ACROSS MUCH OF MN/IA/WI...WITH SFC DEW
POINTS IN THE 60S AND TEMPS IN THE MID 70S TO MID 80S.

FOR THE MOST PART...31.12Z MODELS INITIALIZED WELL. GFS WITH ITS
USUAL QUIRKY SFC DEW POINT ANALYSIS OVER THE MID/UPPER MS VALLEY
BUT NAM 850-500MB HGTS DO NOT PROVIDE THE BEST FIT TO THE RA-OBS
HGTS ACROSS MUCH OF CENTRAL NOAM THIS CYCLE. NAM WITH TOO MUCH 850-
500MB SHORTWAVE TROUGHING OVER NORTHEAST MT PER THE GLASGOW MT
RA-OB. DESPITE THIS...SOLUTIONS REMAIN QUITE SIMILAR FOR TONIGHT
THRU SUN NIGHT AS THE SOUTHERN SASKAT SHORTWAVE DROPS SOUTHEAST
ACROSS THE AREA AND INTO THE CENTRAL GREAT LAKES BY 12Z MON.
DPROG/DT OF 500MB HGTS AT 31.12Z SHOWED THE MODEL RUNS OF 29.12Z
AND VERIFIED WELL ACROSS NOAM/EASTERN PAC WITH BETTER RUN-TO-RUN
CONSISTENCY TO ECMWF. TREND THRU TONIGHT/SUN FAVORS FASTER OF AS
THE TROUGH DROPS ACROSS THE REGION THEN FAVORS A TIGHTENING
COMPROMISE OF THE EARLIER RUNS WITH THE TROUGH INTO THE CENTRAL
LAKES SUN NIGHT. CHECK OF OBS VS. MODEL DATA AT 18Z SHOWED ALL TO BE
REASONABLE WITH THE SOUTHEAST MAN LOW/EASTERN DAKOTAS COLD FRONT. GFS
REMAINED ON THE DRY SIDE WITH SFC DEW POINTS OVER THE MID/UPPER MS
VALLEY. PER WV IMAGERY...ECMWF/GFS/GEM APPEARED BETTER THAN NAM WITH
THE STRENGTH/ POSITION OF THE SOUTHEAST SASKAT SHORTWAVE. GIVEN THIS
AND THE INITIALIZATIONS...FAVORED A NON-NAM CONSENSUS OF THE MODELS
FOR TONIGHT THRU SUN NIGHT. SHORT TERM CONFIDENCE REMAINS ABOVE
AVERAGE.

IN THE SHORT TERM...MAIN SHORTWAVE AND MID/UPPER LEVEL DYNAMICS/LIFT
WITH IT TO PASS TO NORTH OF OR ACROSS THE NORTH END OF THE FCST
TONIGHT/EARLY SUNDAY. MAIN LOWER LEVEL THERMO-DYNAMIC FORCING WITH
THE COLD FRONT PEAKS AROUND 00Z THIS EVENING...THEN GRADUALLY
WEAKENS AS IT COMES EAST AND CROSSES THE FCST AREA LATER THIS
EVENING THRU SUN MORNING. MU CAPE OF 2K-3K J/KG COINCIDENT WITH THE
FRONT/THERMO-DYNAMIC FORCING EARLY THIS EVENING WANES AS WELL AS THE
FRONT/FORCING/LIFT APPROACH/CROSS THE FCST AREA. PW VALUES STILL
PROGGED TO BE AROUND 1.5 INCHES AHEAD OF THE FRONT TONIGHT. RATHER
CONTINUOUS LINE OF CONVECTION EXPECTED TO BE IN PROGRESS FROM NORTH-
CENTRAL MN TO EASTERN SD EARLY THIS EVENING...GRADUALLY WEAKENING/
BECOMING MORE SCT/BKN OVERNIGHT AS IT MOVES INTO ACROSS THE FCST
AREA. CARRIED HIGHEST SHRA/TSRA CHANCES DURING THE LATE EVENING
OVER THE NORTHWEST END OF THE FCST AREA WHEN/WHERE THE LINE OF
CONVECTION WOULD STILL HAVE MORE INSTABILITY/FORCING/LIFT TO WORK
WITH. CONTINUED/TRENDED SHRA/TSRA CHANCES MORE IN THE 20-40 PERCENT
RANGE AFTER MIDNIGHT/SUN MORNING WITH LESS INSTABILITY/FORCING. WITH
THE FASTER MOVEMENT OF THE MID LEVEL TROUGH...TRENDED SHRA/TSRA
CHANCES DOWN/OUT OF THE FCST AREA MORE QUICKLY SUN AFTERNOON.

QUESTION FOR SUN AFTERNOON ONCE THE FRONT/FORCING ARE EAST OF THE
AREA IS EXTENT OF CLOUDS WITH SOME 925-850MB MOISTURE WRAPPING AROUND
THE SFC-MID LEVEL LOW IN DEEP CYCLONIC FLOW...ESPECIALLY OVER THE
NORTH/EAST PORTIONS OF THE FCST AREA. INCREASED CLOUD COVER FOR SUN
AFTERNOON THESE AREAS. CLEARING SUN NIGHT AS THE MID LEVEL LOW
QUICKLY PULLS AWAY AND LOWER LEVEL ANTICYCLONIC FLOW/HIGH PRESSURE
BUILDS INTO THE AREA. 925MB TEMPS IN THE 10C-13C RANGE BY 12Z MON...
FOR COOLER...MORE NEAR NORMAL LOWS MON MORNING. USED A BLEND OF THE
NUMERICAL GUIDANCE LOWS/HIGHS FOR TONIGHT THRU SUN NIGHT.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 325 PM CDT SAT AUG 31 2013

MAIN FORECAST CONCERNS FOR MON THRU TUE NIGHT...FOG POTENTIAL
CENTERED ON DAYBREAK TUE...TEMPERATURES THRU THE PERIOD.

MODELS REMAIN IN GOOD AGREEMENT MON THRU TUE NIGHT AS THE TROUGH
PROGRESSES INTO THE EASTERN CONUS...HGTS RISE AND SHORTWAVE RIDGING
BUILDS INTO THE UPPER MIDWEST. FCST CONFIDENCE IN THIS PERIOD IS
GOOD.

THE CENTER OF THE CANADIAN HIGH DRIFTS FROM NORTHERN MN MON MORNING
TO IL/IN BY WED MORNING. A WEAKENING COLD FRONT SLIDES INTO NORTHERN
WI/CENTRAL MN BY WED MORNING...BUT LIMITED MOISTURE AND MINIMAL
INSTABILITY AHEAD OF IT. THE MON-TUE NIGHT PERIOD CONTINUES TO TREND
DRY/QUIET WITH COOLER/MORE SEASONABLE TEMPS. MONDAY STILL APPEARS AS
THE COOLEST DAY WITH SLOWLY MODERATING TEMPS TUE. COOLEST 925MB OVER
THE AREA AROUND 12Z MON...BUT SOME NORTH GRADIENTS TO KEEP THE
BOUNDARY LAYER STIRRED AND LOWS MON MORNING MOSTLY IN THE 50S. MON
NIGHT THE CENTER OF THE HIGH DRIFTS OVERHEAD WITH LIGHT WINDS/CLEAR
SKIES. 925MB TEMPS TUE MORNING IN THE 12C-15C RANGE...BUT THE
LIGHT/CALM WINDS AND STRONG RADIATIONAL COOLING LOOK TO MAKE TUE
MORNING THE COOLER OF THE MORNINGS...WITH LOWS IN THE MID 40S TO LOW
50S. RADIATIONAL LATE NIGHT/EARLY MORNING VALLEY FOG REMAINS A
CONCERN CENTERED ON 12Z TUE. PREVIOUS FCST GRID SET ALREADY INCLUDED
THIS AND APPEARS WELL TRENDED. USED A BLEND OF THE NUMERICAL
GUIDANCE HIGHS/LOWS FOR MON...TUE/TUE NIGHT. TRENDED TOWARD COOLER
OF GUIDANCE LOWS MON NIGHT WITH THE HIGH OVERHEAD.

FOR WEDNESDAY THROUGH SATURDAY.../DAYS 4-7/...
MEDIUM RANGE MODEL COMING INTO BETTER AGREEMENT WITH A SHORTWAVE TO
DROP SOUTHEAST ACROSS THE EASTERN GREAT LAKES WED...KEEPING THE
REGION UNDER NORTHWEST FLOW ALOFT AND THE RIDGE AXIS OVER THE WESTERN
PLAINS INTO ALB/SASKAT. PATTERN SLOWLY PROGRESSES THU-SAT WITH
RISING HGTS OVER THE UPPER MIDWEST...WHILE THE TROUGHING MOVING
ACROSS THE NORTHERN ROCKIES DEVELOP STRONGER LEE TROUGHING BY LATE
IN THE WEEK. DAY 4-7 FCST CONFIDENCE IS AVERAGE.

IMPROVING MODEL CONSENSUS MOVES A COLD FRONT INTO THE AREA ON WED...
DURING PEAK HEATING. MOISTURE REMAINS IN QUESTION...BUT TREND IS
TOWARD MORE OF AN 850-700MB MOISTURE TRANSPORT/THETA-E CONVERGENCE
SIGNAL...WITH INCREASING PW VALUES INTO THE AREA. MAY YET NEED A
SMALL SHRA/TSRA CHANCE CENTERED ON WED AFTERNOON/EVENING BUT LEFT
THESE PERIODS DRY FOR NOW. POST-FRONTAL CAN HIGH PRESSURE TO
SETTLE ACROSS THE REGION FOR THU. MIXED SIGNALS BY FRI/SAT WITH THE
STRENGTHENING LEE TROUGHING AND SOUTHWEST FLOW AHEAD OF IT PUSHING
INCREASING MOISTURE/INSTABILITY INTO THE UPPER MIDWEST. MAY YET NEED
SHRA/TSRA CHANCES FRI/SAT...DEPENDING ON WHERE ANY LOWER LEVEL
THERMAL/MOISTURE RIDGING AND LOWER LEVEL TOUGHS/BOUNDARIES MAY END
UP. LEFT THU NIGHT THRU SAT DRY FOR NOW PER THE MODEL/ENSEMBLE
CONSENSUS. A WARM-UP ON WED AHEAD OF THE FRONT THEN A BIT OF A COOL-
DOWN ON THU BEHIND THE FRONT...TEMPS GRADUALLY WARM FRI/SAT WITH THE
LOWER LEVEL FLOW BECOMING SOUTH/SOUTHWEST AND THE RISING HGTS ALOFT.
USED THE MODEL/ENSEMBLE CONSENSUS OF NUMERICAL GUIDANCE FOR HIGHS/
LOWS ON WED THRU SAT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1155 AM CDT SAT AUG 31 2013

ITS TAKING AWHILE FOR MORNING MVFR CIGS TO LIFT/BURN OFF...BUT OBS
AND SATELLITE TRENDS SHOWING HOLES AND AN INCREASE IN THE DECKS.
EXPECT MOSTLY SCT CONDITIONS BY 19Z...WITH VFR INTO THE EVENING
HOURS.

LINE OF SHRA/TS WILL BE APPROACHING FROM THE NORTHWEST THIS
EVENING...STRONG/SEVERE. HOWEVER...THEY SHOULD BE ON A WEAKENING
TREND AS THEY NEAR KRST/KLSE AS INSTABILITY WANES AND THE STRONGER
FORCING HOLDS TO THE NORTH. SOME MODELS SUGGEST THAT MUCH OF THE
PCPN MAY FALL APART BY THE TIME IT REACHES WESTERN WI.
MEANWHILE...LAST FEW RUNS OF THE HRRR TREND TOWARD HOLDING IT
TOGETHER THROUGH AT LEAST KRST. THINK THIS IS MORE LIKELY AND WILL
TREND THE TAFS THIS WAY. WILL HOLD WITH VCSH AT KLSE FOR THE TIME
BEING. NOT A LOT OF SATURATION PER BUFKIT SOUNDINGS...SO WILL HOLD
WITH VFR CONDITIONS.

FRONTAL PASSAGE NEAR OR SHORTLY AFTER 12Z SUN...WITH RH FIELDS THEN
POINTING TO SOME THREAT OF MVFR/IFR CIGS. LATEST SATELLITE/SFC OBS
DOES SUPPORT THIS WITH EXPANSIVE LOW CLOUD SHIELD WEST OF A SFC LOW.
THE LOW STAYS WELL NORTH OVERNIGHT/SUN...BUT THIS CLOUD SHIELD COULD
SINK SOUTH EARLY SUN MORNING...BRINGING A SHORT PERIOD OF MVFR CIGS.
GOING TO TREND TOWARD THIS FOR NOW.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....RIECK







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1224 PM CDT SAT AUG 31 2013

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 432 AM CDT SAT AUG 31 2013

MAIN CONCERNS THIS PERIOD ON SKY TRENDS EARLY...THEN PCPN CHANCES
WITH EXPECTED FRONTAL PASSAGE.

OVERALL NO REAL CHANGE TO FORECAST. MODELS CONTINUE TO BE IN GOOD
AGREEMENT WITH SOME MINOR TIMING DIFFERENCES WITH FRONT. GFS AND
00Z ECMWF HAD FAIRLY GOOD HANDLE ON CURRENT PCPN TRENDS SO
FOLLOWED FOR MUCH OF THIS FORECAST.

LATEST MSAS ANALYSIS SHOWS WEAK HIGH PRESSURE OVER STATE...WITH
WEAK WAVE MOVING ALONG FRONT OVER NORTHERN IL. FURTHER TO THE
WEST..COLD FRONT EXTENDS SOUTHWEST THROUGH WESTERN DAKOTAS FROM
LOW OVER LAKE WINNEPEG AREA. SATELLITE IMAGERY SHOWING LOW CLOUDS
EXPANDING WESTWARD OFF LAKE AND BAY INTO CENTRAL WI. SOME HIGH
CLOUDS AND PATCHES OF LOW CLOUDS OUT OF UPPER MI MOVING THROUGH
FAR NORTHERN WI. FOG HAS REMAINED PATCHY...MAINLY OVER NORTH
CENTRAL WI. MOVEMENT OF WAVE ALONG FRONT TO SOUTH HAS HELPED TO
MAINTAIN GRADIENT OVER EASTERN AND CENTRAL WI. HAVE BACKED OFF ON
FOG COVERAGE. HRRR CURRENTLY HANDLING LOW CLOUD COVERAGE FAIRLY
WELL WITH CLOUDS SPREADING INTO PARTS OF CENTRAL WI BY 12Z...THEN
DIMINISHING THROUGH MID TO LATE MORNING. LOWERED FEW TEMPS TO
ACCOUNT FOR CLOUDS.

MODELS CONTINUE TO FOCUS PCPN OVER CWA BETWEEN 06-18Z AS DYNAMICS
WITH UPPER WAVE AND SURFACE FRONT MOVE THROUGH STATE. EXACT COVERAGE
IN QUESTION WITH CONVECTIVE ELEMENTS...SO DID NOT MAKE SIG CHANGE
TO POP CATEGORIES ONLY SLOWING DOWN TIMING BY FEW HOURS.
INSTABILITY OVER REGION MARGINAL LIMITING SEVERE POTENTIAL.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 432 AM CDT SAT AUG 31 2013

MODELS CONTINUED TO GENERATE SMALL AREAS OF QPF ON SUNDAY NIGHT
WITH THE AREA STILL IN CYCLONIC FLOW BEHIND DEPARTING LOW
PRESSURE. HAVE INCLUDED CHANCE/SLIGHT CHANCE FOR SHOWERS ACROSS
MAINLY THE EASTERN AND NORTHERN PARTS OF THE AREA AS A RESULT.
DRIER CONDITIONS ARE THEN EXPECTED AS SURFACE HIGH PRESSURE MOVES
IN AND AN UPPER LEVEL RIDGE AMPLIFIES OVER THE WESTERN
CONUS...LEAVING THE AREA IN NW/WNW FLOW ALOFT. A SHORT WAVE IN THE
UPPER FLOW IS EXPECTED TO PASS WELL TO THE NORTHEAST OF THE STATE
AROUND THE MIDDLE OF THE WEEK AS A SURFACE COLD FRONT MOVES
THROUGH WISCONSIN. A DRY FRONTAL PASSAGE IS FORECAST FOR NOW SINCE
THERE WILL BE LITTLE MOISTURE AHEAD OF THE FRONT.

TEMPERATURES ARE LIKELY TO BE NEAR OR A BIT ABOVE NORMAL...EXCEPT
FOR SUNDAY NIGHT THROUGH MONDAY NIGHT IN THE WAKE OF THE APPROACHING
COLD FRONT.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1223 PM CDT SAT AUG 31 2013

STUBBORN MVFR STRATO-CU DECK OVER ERN WI TRAPPED UNDER
A STRONG INVERSION...DESPITE A STRONG LATE SUMMER SUN. MAY TAKE
TIL MID-AFTERNOON BEFORE WE ARE ABLE TO MIX THESE CLOUDS OUT.
OTHERWISE...WEAK SFC RDG OVER WI TO SLIDE EAST THIS EVENING AND
ALLOW FOR A CDFNT TO APPROACH THE REGION LATER TNGT. VFR
CONDITIONS ARE EXPECTED THIS EVENING...HOWEVER SOME PATCHY FOG IS
LIKELY TO PRECEDE THE LEADING EDGE OF PCPN MAINLY AFTER MIDNGT
WITH CIGS/VSBYS DROPPING TO AT LEAST MVFR CONDITIONS. THE THREAT
OF SHWRS/TSTMS WL THEN CONTINUE INTO SUNDAY MORNING WITH A
CONTINUATION OF MVFR CONDITIONS UNTIL THE CDFNT MOVES THROUGH
ROUGHLY LATE MORNING AND ALLOWS A VFR CONDITIONS TO RETURN.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TE
LONG TERM......MG
AVIATION.......AK







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1155 AM CDT SAT AUG 31 2013

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM CDT SAT AUG 31 2013

IMMEDIATE ISSUE TO DEAL WITH EARLY THIS MORNING IS ONGOING SHOWER
AND THUNDERSTORM ACTIVITY ACROSS FAR SOUTHWEST WI INTO NORTHEAST IA.
RAIN RATES HAVE BEEN FAIRLY HEAVY WITH THESE CLUSTERS OF SHOWERS AND
THUNDERSTORMS WITH 1-3 INCHES INDICATED IN 3-HRLY DUAL POL RADAR
ESTIMATES. THESE SHOWERS AND STORMS ARE THE RESULT OF A CLOSED 925MB
CYCLONIC CIRCULATION OVER CENTRAL IA AND WIND CONVERGENCE TO THE
NORTHEAST OF THIS LOW. THIS CONVERGENCE IN TURN IS WORKING ON HIGHER
PRECIPITABLE WATER VALUES ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI.
RAP SHOWS THIS LOW AND CONVERGENCE/RESULTANT SHOWERS AND
THUNDERSTORMS SLIPPING SOUTH AND EAST OF THE AREA BY DAWN.

OTHERWISE...WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING
ANOTHER FAIRLY VIGOROUS MID-LEVEL SHORTWAVE TROUGH MOVING EAST
ACROSS CENTRAL DAKOTAS/NEBRASKA. RADAR MOSAIC SHOWING A CLUSTER OF
THUNDERSTORMS ALONG THE ND/SD BORDER WHERE SURGE OF 850MB MOISTURE
TRANSPORT WAS OCCURING AHEAD OF THE MID-LEVEL WAVE. THIS WILL BE OUR
WEATHER-MAKER FOR TONIGHT INTO SUNDAY.

FOR TODAY...ONCE THE SHOWERS AND STORMS DEPART FAR SOUTHERN PORTION
OF THE AREA THIS MORNING...WEAK RIDGE OF HIGH PRESSURE WILL PROVIDE
SLIGHTLY DRIER AND COOLER CONDITIONS. WILL SEE SOME LOW CLOUDS
ALONG/SOUTH OF I-90 THIS MORNING...BUT SHOULD BURN OFF BY LATE
MORNING. WITH MOSTLY SUNNY SKIES THROUGH THE REST OF THE DAY...LOOK
FOR HIGHS IN THE 80-85 DEGREE RANGE WITH DRIER DEW POINTS IN THE
LOWER TO MIDDLE 60S.

AFOREMENTIONED MID-LEVEL WAVE/SURFACE COLD FRONT MOVES TOWARD THE
AREA TONIGHT...AND MAKING PASSAGE ACROSS THE AREA SUNDAY MORNING FOR
A DECENT SHOT AT SOME SHOWERS AND THUNDERSTORMS. MODELS ARE SHOWING
BETTER MOISTURE TRANSPORT HEADING NORTH OF THE AREA...TIED TO BETTER
FORCING OF THE MID-LEVEL WAVE AND PROXIMITY TO SURFACE LOW OVER
SOUTHERN ONTARIO CANADA. FOR THIS REASON...KEPT LIKELY/HIGHER-END
CHANCE POPS NORTH OF I-94...AND TAPERING OFF SOUTH OF THIS. BEST
CHANCES SEEM TO CENTERED IN DURING THE 06-12Z TIME FRAME. THERE MAY
BE SOME UPSCALE IN THE INTENSITY OF THE SHOWERS/THUNDERSTORMS ACROSS
THE EAST IN THE 15Z-21Z TIME FRAME AS 0-1KM MLCAPE INCREASES INTO
THE 1500-2500J/KG RANGE ALONG WITH INCREASING 0-3KM BULK SHEAR. WILL
HAVE TO KEEP AND EYE ON THIS FOR SEVERE POTENTIAL...ESPECIALLY IF
THE FRONT SLOWS SOME AND INSTABILITY IS ALLOWED TO BUILD MORE AHEAD
OF THE FRONT.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM CDT SAT AUG 31 2013

GFS/ECMWF IN GOOD AGREEMENT SUNDAY NIGHT THROUGH TUESDAY IN BRINGING
HIGH PRESSURE ACROSS THE AREA IN NORTHWEST FLOW ALOFT FOR DRIER AND
COOLER WEATHER. LOOK FOR HIGHS SUNDAY AND MONDAY IN THE 70S WITH
OVERNIGHT LOWS SUNDAY NIGHT IN THE 50S AND IN THE UPPER 40S/NEAR 50
MONDAY NIGHT. ALSO...LOOKS LIKE A GOOD CHANCE OF PATCHY/AREAS OF FOG
MONDAY NIGHT ESPECIALLY IN THE RIVER VALLEYS AS THE HIGH SETTLES
OVERHEAD.

SOME WARMING EXPECTED ON WEDNESDAY AHEAD OF A COLD FRONT DROPPING
SOUTH OUT OF CANADA WITH HIGHS TOPPING OFF IN THE UPPER 70S TO THE
LOWER 80S. MODELS SHOW THIS FRONT CONTINUING TO SINK SOUTH ACROSS
THE AREA WEDNESDAY NIGHT. THE ECMWF IS MOSTLY DRY WITH THIS FROPA
WHILE THE GFS WANTS TO CONVECT ALONG/AHEAD OF THE FRONT. HAVE
INCLUDED A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FOR NOW FOR AREAS
ALONG/SOUTH OF I-94.

FOR THURSDAY THROUGH FRIDAY...COOLER/OVERALL DRY NORTHWEST FLOW
ALOFT WILL PREVAIL AS UPPER LEVEL RIDGING BUILDS OVER THE PLAINS.
LOOKING FOR HIGHS IN THE 70S ON THURSDAY AND IN THE UPPER 70S/LOWER
80S FRIDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1155 AM CDT SAT AUG 31 2013

ITS TAKING AWHILE FOR MORNING MVFR CIGS TO LIFT/BURN OFF...BUT OBS
AND SATELLITE TRENDS SHOWING HOLES AND AN INCREASE IN THE DECKS.
EXPECT MOSTLY SCT CONDITIONS BY 19Z...WITH VFR INTO THE EVENING
HOURS.

LINE OF SHRA/TS WILL BE APPROACHING FROM THE NORTHWEST THIS
EVENING...STRONG/SEVERE. HOWEVER...THEY SHOULD BE ON A WEAKENING
TREND AS THEY NEAR KRST/KLSE AS INSTABILITY WANES AND THE STRONGER
FORCING HOLDS TO THE NORTH. SOME MODELS SUGGEST THAT MUCH OF THE
PCPN MAY FALL APART BY THE TIME IT REACHES WESTERN WI.
MEANWHILE...LAST FEW RUNS OF THE HRRR TREND TOWARD HOLDING IT
TOGETHER THROUGH AT LEAST KRST. THINK THIS IS MORE LIKELY AND WILL
TREND THE TAFS THIS WAY. WILL HOLD WITH VCSH AT KLSE FOR THE TIME
BEING. NOT A LOT OF SATURATION PER BUFKIT SOUNDINGS...SO WILL HOLD
WITH VFR CONDITIONS.

FRONTAL PASSAGE NEAR OR SHORTLY AFTER 12Z SUN...WITH RH FIELDS THEN
POINTING TO SOME THREAT OF MVFR/IFR CIGS. LATEST SATELLITE/SFC OBS
DOES SUPPORT THIS WITH EXPANSIVE LOW CLOUD SHIELD WEST OF A SFC LOW.
THE LOW STAYS WELL NORTH OVERNIGHT/SUN...BUT THIS CLOUD SHIELD COULD
SINK SOUTH EARLY SUN MORNING...BRINGING A SHORT PERIOD OF MVFR CIGS.
GOING TO TREND TOWARD THIS FOR NOW.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK










AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 652 AM CDT SAT AUG 31 2013

UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 432 AM CDT SAT AUG 31 2013

MAIN CONCERNS THIS PERIOD ON SKY TRENDS EARLY...THEN PCPN CHANCES
WITH EXPECTED FRONTAL PASSAGE.

OVERALL NO REAL CHANGE TO FORECAST. MODELS CONTINUE TO BE IN GOOD
AGREEMENT WITH SOME MINOR TIMING DIFFERENCES WITH FRONT. GFS AND
00Z ECMWF HAD FAIRLY GOOD HANDLE ON CURRENT PCPN TRENDS SO
FOLLOWED FOR MUCH OF THIS FORECAST.

LATEST MSAS ANALYSIS SHOWS WEAK HIGH PRESSURE OVER STATE...WITH
WEAK WAVE MOVING ALONG FRONT OVER NORTHERN IL. FURTHER TO THE
WEST..COLD FRONT EXTENDS SOUTHWEST THROUGH WESTERN DAKOTAS FROM
LOW OVER LAKE WINNEPEG AREA. SATELLITE IMAGERY SHOWING LOW CLOUDS
EXPANDING WESTWARD OFF LAKE AND BAY INTO CENTRAL WI. SOME HIGH
CLOUDS AND PATCHES OF LOW CLOUDS OUT OF UPPER MI MOVING THROUGH
FAR NORTHERN WI. FOG HAS REMAINED PATCHY...MAINLY OVER NORTH
CENTRAL WI. MOVEMENT OF WAVE ALONG FRONT TO SOUTH HAS HELPED TO
MAINTAIN GRADIENT OVER EASTERN AND CENTRAL WI. HAVE BACKED OFF ON
FOG COVERAGE. HRRR CURRENTLY HANDLING LOW CLOUD COVERAGE FAIRLY
WELL WITH CLOUDS SPREADING INTO PARTS OF CENTRAL WI BY 12Z...THEN
DIMINISHING THROUGH MID TO LATE MORNING. LOWERED FEW TEMPS TO
ACCOUNT FOR CLOUDS.

MODELS CONTINUE TO FOCUS PCPN OVER CWA BETWEEN 06-18Z AS DYNAMICS
WITH UPPER WAVE AND SURFACE FRONT MOVE THROUGH STATE. EXACT COVERAGE
IN QUESTION WITH CONVECTIVE ELEMENTS...SO DID NOT MAKE SIG CHANGE
TO POP CATEGORIES ONLY SLOWING DOWN TIMING BY FEW HOURS.
INSTABILITY OVER REGION MARGINAL LIMITING SEVERE POTENTIAL.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 432 AM CDT SAT AUG 31 2013

MODELS CONTINUED TO GENERATE SMALL AREAS OF QPF ON SUNDAY NIGHT
WITH THE AREA STILL IN CYCLONIC FLOW BEHIND DEPARTING LOW
PRESSURE. HAVE INCLUDED CHANCE/SLIGHT CHANCE FOR SHOWERS ACROSS
MAINLY THE EASTERN AND NORTHERN PARTS OF THE AREA AS A RESULT.
DRIER CONDITIONS ARE THEN EXPECTED AS SURFACE HIGH PRESSURE MOVES
IN AND AN UPPER LEVEL RIDGE AMPLIFIES OVER THE WESTERN
CONUS...LEAVING THE AREA IN NW/WNW FLOW ALOFT. A SHORT WAVE IN THE
UPPER FLOW IS EXPECTED TO PASS WELL TO THE NORTHEAST OF THE STATE
AROUND THE MIDDLE OF THE WEEK AS A SURFACE COLD FRONT MOVES
THROUGH WISCONSIN. A DRY FRONTAL PASSAGE IS FORECAST FOR NOW SINCE
THERE WILL BE LITTLE MOISTURE AHEAD OF THE FRONT.

TEMPERATURES ARE LIKELY TO BE NEAR OR A BIT ABOVE NORMAL...EXCEPT
FOR SUNDAY NIGHT THROUGH MONDAY NIGHT IN THE WAKE OF THE APPROACHING
COLD FRONT.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 625 AM CDT SAT AUG 31 2013

CONCERNS THIS MORNING ON FOG AND LOW CLOUDS. WITH ONLY SCATTERED
HIGH CLOUDS OVER FAR NORTHERN WI THIS MORNING EXPECT VSBYS TO
QUICKLY IMPROVE. LOW CLOUDS OVER EASTERN TAF SITES WILL LINGER A
BIT LONGER...WITH INVERSION AND LIGHT WINDS. MODELS SUGGEST
DIMINISHING MID TO LATE MORNING. HIGH IFR OR MVFR CIGS EXPECTED
TIL THEN. UPPER DISTURBANCE AND COLD FRONT TO BRING CHANCE OF
THUNDERSTORMS LATE TONIGHT TO WESTERN TAF SITES.


&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TE
LONG TERM......MG
AVIATION.......TE








AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 634 AM CDT SAT AUG 31 2013

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM CDT SAT AUG 31 2013

IMMEDIATE ISSUE TO DEAL WITH EARLY THIS MORNING IS ONGOING SHOWER
AND THUNDERSTORM ACTIVITY ACROSS FAR SOUTHWEST WI INTO NORTHEAST IA.
RAIN RATES HAVE BEEN FAIRLY HEAVY WITH THESE CLUSTERS OF SHOWERS AND
THUNDERSTORMS WITH 1-3 INCHES INDICATED IN 3-HRLY DUAL POL RADAR
ESTIMATES. THESE SHOWERS AND STORMS ARE THE RESULT OF A CLOSED 925MB
CYCLONIC CIRCULATION OVER CENTRAL IA AND WIND CONVERGENCE TO THE
NORTHEAST OF THIS LOW. THIS CONVERGENCE IN TURN IS WORKING ON HIGHER
PRECIPITABLE WATER VALUES ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI.
RAP SHOWS THIS LOW AND CONVERGENCE/RESULTANT SHOWERS AND
THUNDERSTORMS SLIPPING SOUTH AND EAST OF THE AREA BY DAWN.

OTHERWISE...WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING
ANOTHER FAIRLY VIGOROUS MID-LEVEL SHORTWAVE TROUGH MOVING EAST
ACROSS CENTRAL DAKOTAS/NEBRASKA. RADAR MOSAIC SHOWING A CLUSTER OF
THUNDERSTORMS ALONG THE ND/SD BORDER WHERE SURGE OF 850MB MOISTURE
TRANSPORT WAS OCCURING AHEAD OF THE MID-LEVEL WAVE. THIS WILL BE OUR
WEATHER-MAKER FOR TONIGHT INTO SUNDAY.

FOR TODAY...ONCE THE SHOWERS AND STORMS DEPART FAR SOUTHERN PORTION
OF THE AREA THIS MORNING...WEAK RIDGE OF HIGH PRESSURE WILL PROVIDE
SLIGHTLY DRIER AND COOLER CONDITIONS. WILL SEE SOME LOW CLOUDS
ALONG/SOUTH OF I-90 THIS MORNING...BUT SHOULD BURN OFF BY LATE
MORNING. WITH MOSTLY SUNNY SKIES THROUGH THE REST OF THE DAY...LOOK
FOR HIGHS IN THE 80-85 DEGREE RANGE WITH DRIER DEW POINTS IN THE
LOWER TO MIDDLE 60S.

AFOREMENTIONED MID-LEVEL WAVE/SURFACE COLD FRONT MOVES TOWARD THE
AREA TONIGHT...AND MAKING PASSAGE ACROSS THE AREA SUNDAY MORNING FOR
A DECENT SHOT AT SOME SHOWERS AND THUNDERSTORMS. MODELS ARE SHOWING
BETTER MOISTURE TRANSPORT HEADING NORTH OF THE AREA...TIED TO BETTER
FORCING OF THE MID-LEVEL WAVE AND PROXIMITY TO SURFACE LOW OVER
SOUTHERN ONTARIO CANADA. FOR THIS REASON...KEPT LIKELY/HIGHER-END
CHANCE POPS NORTH OF I-94...AND TAPERING OFF SOUTH OF THIS. BEST
CHANCES SEEM TO CENTERED IN DURING THE 06-12Z TIME FRAME. THERE MAY
BE SOME UPSCALE IN THE INTENSITY OF THE SHOWERS/THUNDERSTORMS ACROSS
THE EAST IN THE 15Z-21Z TIME FRAME AS 0-1KM MLCAPE INCREASES INTO
THE 1500-2500J/KG RANGE ALONG WITH INCREASING 0-3KM BULK SHEAR. WILL
HAVE TO KEEP AND EYE ON THIS FOR SEVERE POTENTIAL...ESPECIALLY IF
THE FRONT SLOWS SOME AND INSTABILITY IS ALLOWED TO BUILD MORE AHEAD
OF THE FRONT.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM CDT SAT AUG 31 2013

GFS/ECMWF IN GOOD AGREEMENT SUNDAY NIGHT THROUGH TUESDAY IN BRINGING
HIGH PRESSURE ACROSS THE AREA IN NORTHWEST FLOW ALOFT FOR DRIER AND
COOLER WEATHER. LOOK FOR HIGHS SUNDAY AND MONDAY IN THE 70S WITH
OVERNIGHT LOWS SUNDAY NIGHT IN THE 50S AND IN THE UPPER 40S/NEAR 50
MONDAY NIGHT. ALSO...LOOKS LIKE A GOOD CHANCE OF PATCHY/AREAS OF FOG
MONDAY NIGHT ESPECIALLY IN THE RIVER VALLEYS AS THE HIGH SETTLES
OVERHEAD.

SOME WARMING EXPECTED ON WEDNESDAY AHEAD OF A COLD FRONT DROPPING
SOUTH OUT OF CANADA WITH HIGHS TOPPING OFF IN THE UPPER 70S TO THE
LOWER 80S. MODELS SHOW THIS FRONT CONTINUING TO SINK SOUTH ACROSS
THE AREA WEDNESDAY NIGHT. THE ECMWF IS MOSTLY DRY WITH THIS FROPA
WHILE THE GFS WANTS TO CONVECT ALONG/AHEAD OF THE FRONT. HAVE
INCLUDED A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FOR NOW FOR AREAS
ALONG/SOUTH OF I-94.

FOR THURSDAY THROUGH FRIDAY...COOLER/OVERALL DRY NORTHWEST FLOW
ALOFT WILL PREVAIL AS UPPER LEVEL RIDGING BUILDS OVER THE PLAINS.
LOOKING FOR HIGHS IN THE 70S ON THURSDAY AND IN THE UPPER 70S/LOWER
80S FRIDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 633 AM CDT SAT AUG 31 2013

UNDER WEAK HIGH PRESSURE...SOME MORNING MVFR CLOUDS ARE AROUND THE
TAF SITES. THIS CLOUD DECK IS PATCHY AND IT MAY MOVE IN AND OUT OF
THE AIRFIELDS THIS MORNING BEFORE CLEARING. THERE ARE SOME HIGHER
IFR CLOUDS AROUND TOO...SO THIS MAY BOUNCE INTO KRST FOR PERIODS.
KLSE SHOULD REMAIN MVFR.

THE REMINDER OF THE PERIOD SHOULD BE VFR AS A COLD FRONT
APPROACHES THE AIRFIELDS FROM THE NORTHWEST TONIGHT. EVENING
THUNDERSTORMS NEAR THE DAKOTAS/MINNESOTA WILL BE QUITE STRONG AND
MOVE EAST TOWARD KRST DURING THE EVENING. HOWEVER...THEY ARE
EXPECTED TO RAPIDLY WEAKEN AS THE ATMOSPHERE STABILIZES.
THUS...HAVE INCLUDED A VCSH THIS EVENING FOR DEBRIS REMAINING FROM
THE THUNDERSTORMS SHIFTING EAST INTO KLSE/KRST.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION...BAUMGARDT







FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE



 .SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 432 AM CDT SAT AUG 31 2013

MAIN CONCERNS THIS PERIOD ON SKY TRENDS EARLY...THEN PCPN CHANCES
WITH EXPECTED FRONTAL PASSAGE.

OVERALL NO REAL CHANGE TO FORECAST. MODELS CONTINUE TO BE IN GOOD
AGREEMENT WITH SOME MINOR TIMING DIFFERENCES WITH FRONT. GFS AND
00Z ECMWF HAD FAIRLY GOOD HANDLE ON CURRENT PCPN TRENDS SO
FOLLOWED FOR MUCH OF THIS FORECAST.

LATEST MSAS ANALYSIS SHOWS WEAK HIGH PRESSURE OVER STATE...WITH
WEAK WAVE MOVING ALONG FRONT OVER NORTHERN IL. FURTHER TO THE
WEST..COLD FRONT EXTENDS SOUTHWEST THROUGH WESTERN DAKOTAS FROM
LOW OVER LAKE WINNEPEG AREA. SATELLITE IMAGERY SHOWING LOW CLOUDS
EXPANDING WESTWARD OFF LAKE AND BAY INTO CENTRAL WI. SOME HIGH
CLOUDS AND PATCHES OF LOW CLOUDS OUT OF UPPER MI MOVING THROUGH
FAR NORTHERN WI. FOG HAS REMAINED PATCHY...MAINLY OVER NORTH
CENTRAL WI. MOVEMENT OF WAVE ALONG FRONT TO SOUTH HAS HELPED TO
MAINTAIN GRADIENT OVER EASTERN AND CENTRAL WI. HAVE BACKED OFF ON
FOG COVERAGE. HRRR CURRENTLY HANDLING LOW CLOUD COVERAGE FAIRLY
WELL WITH CLOUDS SPREADING INTO PARTS OF CENTRAL WI BY 12Z...THEN
DIMINISHING THROUGH MID TO LATE MORNING. LOWERED FEW TEMPS TO
ACCOUNT FOR CLOUDS.

MODELS CONTINUE TO FOCUS PCPN OVER CWA BETWEEN 06-18Z AS DYNAMICS
WITH UPPER WAVE AND SURFACE FRONT MOVE THROUGH STATE. EXACT COVERAGE
IN QUESTION WITH CONVECTIVE ELEMENTS...SO DID NOT MAKE SIG CHANGE
TO POP CATEGORIES ONLY SLOWING DOWN TIMING BY FEW HOURS.
INSTABILITY OVER REGION MARGINAL LIMITING SEVERE POTENTIAL.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 432 AM CDT SAT AUG 31 2013

MODELS CONTINUED TO GENERATE SMALL AREAS OF QPF ON SUNDAY NIGHT
WITH THE AREA STILL IN CYCLONIC FLOW BEHIND DEPARTING LOW
PRESSURE. HAVE INCLUDED CHANCE/SLIGHT CHANCE FOR SHOWERS ACROSS
MAINLY THE EASTERN AND NORTHERN PARTS OF THE AREA AS A RESULT.
DRIER CONDITIONS ARE THEN EXPECTED AS SURFACE HIGH PRESSURE MOVES
IN AND AN UPPER LEVEL RIDGE AMPLIFIES OVER THE WESTERN
CONUS...LEAVING THE AREA IN NW/WNW FLOW ALOFT. A SHORT WAVE IN THE
UPPER FLOW IS EXPECTED TO PASS WELL TO THE NORTHEAST OF THE STATE
AROUND THE MIDDLE OF THE WEEK AS A SURFACE COLD FRONT MOVES
THROUGH WISCONSIN. A DRY FRONTAL PASSAGE IS FORECAST FOR NOW SINCE
THERE WILL BE LITTLE MOISTURE AHEAD OF THE FRONT.

TEMPERATURES ARE LIKELY TO BE NEAR OR A BIT ABOVE NORMAL...EXCEPT
FOR SUNDAY NIGHT THROUGH MONDAY NIGHT IN THE WAKE OF THE APPROACHING
COLD FRONT.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1048 PM CDT FRI AUG 30 2013

HIGH PRESSURE...SOME MVFR CIGS WILL LINGER NEAR THE LAKE MICHIGAN
SHORELINE AND THE WISCONSIN/UPPER MICHIGAN BORDER AT THE BEGINNING
OF THE TAF PERIOD...BUT THINK THEY WILL STAY EAST OF GRB/ATW AND
NORTH OF RHI. LIGHT WINDS...CLEAR TO PARTLY CLOUDY SKIES AND LOW
LEVEL MOISTURE FROM RECENT RAINFALL WILL LEAD TO FOG DEVELOPMENT
OVERNIGHT. WILL CARRY IFR/LIFR CONDITIONS AT MOST OF THE TAF SITES
OVERNIGHT INTO EARLY SATURDAY. HEAVY RAINFALL OCCURRED AT RHI OVER
THE PAST DAY...AND THE SFC HIGH WILL BE CENTERED OVER NORTH
CENTRAL WI...SO DENSE FOG APPEARS LIKELY THERE. CONDITIONS WILL
PROBABLY DROP BLO AIRPORT MINIMUMS AT RHI. IMPROVING CONDITIONS AT
ALL OF THE TAF SITES CAN BE ANTICIPATED BY AROUND 14Z/SAT...WITH
SCT CUMULUS AND SOME PATCHY CIRRUS EXPECTED FOR THE REST OF THE
DAY. AN APPROACHING COLD FRONT MAY BRING SOME SHOWERS OR EVEN A
THUNDERSTORM INTO NORTH CENTRAL WISCONSIN TOWARD MIDNIGHT
SATURDAY NIGHT. FOR NOW...HAVE ONLY ADDED A PROB30 GROUP FOR
SHOWERS AT RHI.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TE
LONG TERM......MG
AVIATION.......KIECKBUSCH







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 330 AM CDT SAT AUG 31 2013

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 330 AM CDT SAT AUG 31 2013

IMMEDIATE ISSUE TO DEAL WITH EARLY THIS MORNING IS ONGOING SHOWER
AND THUNDERSTORM ACTIVITY ACROSS FAR SOUTHWEST WI INTO NORTHEAST IA.
RAIN RATES HAVE BEEN FAIRLY HEAVY WITH THESE CLUSTERS OF SHOWERS AND
THUNDERSTORMS WITH 1-3 INCHES INDICATED IN 3-HRLY DUAL POL RADAR
ESTIMATES. THESE SHOWERS AND STORMS ARE THE RESULT OF A CLOSED 925MB
CYCLONIC CIRCULATION OVER CENTRAL IA AND WIND CONVERGENCE TO THE
NORTHEAST OF THIS LOW. THIS CONVERGENCE IN TURN IS WORKING ON HIGHER
PRECIPITABLE WATER VALUES ACROSS NORTHEAST IA INTO FAR SOUTHWEST WI.
RAP SHOWS THIS LOW AND CONVERGENCE/RESULTANT SHOWERS AND
THUNDERSTORMS SLIPPING SOUTH AND EAST OF THE AREA BY DAWN.

OTHERWISE...WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING
ANOTHER FAIRLY VIGOROUS MID-LEVEL SHORTWAVE TROUGH MOVING EAST
ACROSS CENTRAL DAKOTAS/NEBRASKA. RADAR MOSAIC SHOWING A CLUSTER OF
THUNDERSTORMS ALONG THE ND/SD BORDER WHERE SURGE OF 850MB MOISTURE
TRANSPORT WAS OCCURING AHEAD OF THE MID-LEVEL WAVE. THIS WILL BE OUR
WEATHER-MAKER FOR TONIGHT INTO SUNDAY.

FOR TODAY...ONCE THE SHOWERS AND STORMS DEPART FAR SOUTHERN PORTION
OF THE AREA THIS MORNING...WEAK RIDGE OF HIGH PRESSURE WILL PROVIDE
SLIGHTLY DRIER AND COOLER CONDITIONS. WILL SEE SOME LOW CLOUDS
ALONG/SOUTH OF I-90 THIS MORNING...BUT SHOULD BURN OFF BY LATE
MORNING. WITH MOSTLY SUNNY SKIES THROUGH THE REST OF THE DAY...LOOK
FOR HIGHS IN THE 80-85 DEGREE RANGE WITH DRIER DEW POINTS IN THE
LOWER TO MIDDLE 60S.

AFOREMENTIONED MID-LEVEL WAVE/SURFACE COLD FRONT MOVES TOWARD THE
AREA TONIGHT...AND MAKING PASSAGE ACROSS THE AREA SUNDAY MORNING FOR
A DECENT SHOT AT SOME SHOWERS AND THUNDERSTORMS. MODELS ARE SHOWING
BETTER MOISTURE TRANSPORT HEADING NORTH OF THE AREA...TIED TO BETTER
FORCING OF THE MID-LEVEL WAVE AND PROXIMITY TO SURFACE LOW OVER
SOUTHERN ONTARIO CANADA. FOR THIS REASON...KEPT LIKELY/HIGHER-END
CHANCE POPS NORTH OF I-94...AND TAPERING OFF SOUTH OF THIS. BEST
CHANCES SEEM TO CENTERED IN DURING THE 06-12Z TIME FRAME. THERE MAY
BE SOME UPSCALE IN THE INTENSITY OF THE SHOWERS/THUNDERSTORMS ACROSS
THE EAST IN THE 15Z-21Z TIME FRAME AS 0-1KM MLCAPE INCREASES INTO
THE 1500-2500J/KG RANGE ALONG WITH INCREASING 0-3KM BULK SHEAR. WILL
HAVE TO KEEP AND EYE ON THIS FOR SEVERE POTENTIAL...ESPECIALLY IF
THE FRONT SLOWS SOME AND INSTABILITY IS ALLOWED TO BUILD MORE AHEAD
OF THE FRONT.

.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM CDT SAT AUG 31 2013

GFS/ECMWF IN GOOD AGREEMENT SUNDAY NIGHT THROUGH TUESDAY IN BRINGING
HIGH PRESSURE ACROSS THE AREA IN NORTHWEST FLOW ALOFT FOR DRIER AND
COOLER WEATHER. LOOK FOR HIGHS SUNDAY AND MONDAY IN THE 70S WITH
OVERNIGHT LOWS SUNDAY NIGHT IN THE 50S AND IN THE UPPER 40S/NEAR 50
MONDAY NIGHT. ALSO...LOOKS LIKE A GOOD CHANCE OF PATCHY/AREAS OF FOG
MONDAY NIGHT ESPECIALLY IN THE RIVER VALLEYS AS THE HIGH SETTLES
OVERHEAD.

SOME WARMING EXPECTED ON WEDNESDAY AHEAD OF A COLD FRONT DROPPING
SOUTH OUT OF CANADA WITH HIGHS TOPPING OFF IN THE UPPER 70S TO THE
LOWER 80S. MODELS SHOW THIS FRONT CONTINUING TO SINK SOUTH ACROSS
THE AREA WEDNESDAY NIGHT. THE ECMWF IS MOSTLY DRY WITH THIS FROPA
WHILE THE GFS WANTS TO CONVECT ALONG/AHEAD OF THE FRONT. HAVE
INCLUDED A SLIGHT CHANCE OF SHOWERS/THUNDERSTORMS FOR NOW FOR AREAS
ALONG/SOUTH OF I-94.

FOR THURSDAY THROUGH FRIDAY...COOLER/OVERALL DRY NORTHWEST FLOW
ALOFT WILL PREVAIL AS UPPER LEVEL RIDGING BUILDS OVER THE PLAINS.
LOOKING FOR HIGHS IN THE 70S ON THURSDAY AND IN THE UPPER 70S/LOWER
80S FRIDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1145 PM CDT FRI AUG 30 2013

THE WEAK AREA OF SURFACE HIGH PRESSURE REMAINS OFF TO THE
NORTHEAST OF THE AREA AS A SECONDARY AREA OF LOW PRESSURE HAS
FORMED ALONG THE FRONT OVER SOUTHEAST IOWA. THIS IS HELPING TO
MAINTAIN A GRADIENT WITH EAST TO NORTHEAST WINDS AROUND 5 KNOTS.
DEW POINTS CONTINUE TO DROP IN THIS NORTHEAST FLOW WITH A 14
DEGREE TEMP/DEW POINT SPREAD AT KLSE AT 03Z. CONTINUES TO LOOK
MORE AND MORE UNLIKELY THAT FOG WILL FORM OVERNIGHT AS THE THE
TEMP AND DEW POINT SHOULD CONTINUE TO CHASE EACH OTHER DOWNWARD.
HAVE REMOVED THE IFR FOG FOR BOTH SITES WHILE MAINTAINING SOME
MVFR RESTRICTIONS FOR LATE TONIGHT. THE 31.03Z RAP CONTINUES TO
SUGGEST AN MVFR CLOUD DECK ADVECTING IN FROM THE EAST BUT NOW
TAKES THIS MOISTURE A LITTLE FARTHER SOUTH THAN PREVIOUS RUNS HAD
SHOWN. MVFR CEILINGS ARE IN PLACE ACROSS SOUTHEAST WISCONSIN AND
HAVE OPTED TO LEAVE THIS POSSIBILITY IN DUE TO THE CLOSE PROXIMITY
OF THESE IN THE LOW LEVEL EAST FLOW. ONCE CONDITIONS MIX OUT
SATURDAY MORNING...VFR CONDITIONS EXPECTED FOR THE REMAINDER OF
THE PERIOD.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04










AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1145 PM CDT FRI AUG 30 2013

.UPDATE...
ISSUED AT 649 PM CDT FRI AUG 30 2013

THE COLD FRONT HAS MOVED SOUTH OF THE AREA WITH DEW POINTS SLOWLY
DROPPING INTO THE LOWER 70S BEHIND IT. THAT COMBINED WITH THE
NORMAL DIURNAL COOLING OF THE AIR TEMPERATURE HAS ALLOWED THE HEAT
INDICES TO FALL BELOW 100 FOR ALL BUT THE KOLZ AREA...AND THIS
WILL OCCUR THERE OVER THE NEXT HOUR AS WELL. WILL ALLOW THE HEAT
ADVISORY TO EXPIRE AS SCHEDULED AT 7 PM.

&&

.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 331 PM CDT FRI AUG 30 2013

MAIN FORECAST CONCERNS THIS PACKAGE...LINGERING SHRA/TSRA CHANCE THIS
EVENING ACROSS THE SOUTH END OF THE FCST AREA...FOG POTENTIAL LATER
TONIGHT/EARLY SAT...SHRA/TSRA CHANCES SAT NIGHT.

18Z DATA ANALYSIS HAD THE COLD FRONT NEAR A KMTW/KDLL/KPDC/KALO
LINE...MAKING STEADY PROGRESS SOUTH/EAST. FRONT QUIET ACROSS IA/
WESTERN WI...HOWEVER LAPS SOUNDINGS SHOWING SOME 3K-4K J/KG SB CAPE
AND LITTLE IF ANY CIN NEAR THE FRONT IN THESE AREAS. DRIER AIR
BEHIND THE FRONT LAGS ABOUT 100 MILES...WITH SFC DEW POINTS
REMAINING IN THE 70-75F RANGE ACROSS THE SOUTH 1/2 OF WI AND
SOUTHEAST CORNER OF MN. LOWER LEVEL STRATO-CU CONTINUED TO SPREAD
SOUTH ACROSS WI/MN BEHIND THE FRONT...BUT WERE SLOWLY LIFTING/MIXING/
DISSIPATING WITH DIURNAL WARMING/MIXING AND ANTI-CYCLONIC FLOW/
DIVERGENCE AROUND THE WEAK HIGH BUILDING SOUTH INTO THE REGION.

NO BIG PROBLEMS NOTED WITH 30.12Z MODEL INITIALIZATIONS. SOLUTIONS
CONTINUE TO CONVERGE TOWARD A TIGHTER CONSENSUS SOLUTION FOR
TONIGHT AND THRU THE HOLIDAY WEEKEND. DPROG/DT OF 500MB HGTS AT
30.12Z SHOWED THE MODEL RUNS OF 28.12Z AND 29.12Z VERIFIED QUITE
WELL ACROSS NOAM/EASTERN PAC...ESPECIALLY ACROSS CAN/AK AND EASTERN
PAC. TREND FOR TONIGHT/SAT IS TOWARD A COMPROMISE TIMING/STRENGTH
AS THE SHORTWAVE OVER SOUTHERN BC THIS MORNING TRACKS TO SOUTHERN
MANITOBA BY 00Z SUN...THEN TO NORTH OF LK SUPERIOR AND INTO/ACROSS
THE AREA LATER SAT NIGHT. ECMWF WITH SOMEWHAT BETTER RUN-TO-RUN
CONSISTENCY THAN THE OTHERS. CHECK OF OBS VS. MODEL DATA AT 18Z
SHOWED ALL WERE REASONABLE WITH THE SFC FRONT LOCATION ACROSS THE
REGION. GFS WAS LOW WITH SFC DEW POINTS POOLED EITHER SIDE OF THE
FRONT WHILE OTHER MODELS APPEARED QUITE GOOD WITH THESE. PER
WV IMAGERY...NAM/GEM/ECMWF APPEARED BETTER THAN GFS WITH THE
SHORTWAVE OVER SOUTHERN BC. ALL MODELS WITH TOO MUCH 12Z-18Z PRECIP
NEAR THE FRONT OVER EASTERN WI INTO SOUTHWEST WI AND NEARBY AREAS.
EVEN WITH THE GFS LOOKING A LITTLE OFF AT 18Z...ITS SOLUTION BY SAT
NIGHT/SUN MORNING STILL QUITE SIMILAR TO OTHER MODELS...THUS FAVORED
THE MODEL/ENSEMBLE CONSENSUS. SHORT-TERM FCST CONFIDENCE IS GOOD
THIS CYCLE.

IN THE SHORT TERM...FRONTAL BOUNDARY ALREADY NEARING THE SOUTH END
OF THE FCST AREA AT MID-AFTERNOON AND WILL BE INTO CENTRAL IA TO
NORTHERN IL BY THIS EVENING. ANY SHRA/TSRA CHANCE LATE THIS
AFTERNOON APPEARS TIED TO THE SFC-925MB CONVERGENCE WITH THE
FRONT. WITH DEW POINTS STILL IN THE LOW TO MID 70S SOME 50 MILES
OR SO BEHIND THE FRONT...WILL EXTEND THE HEAT ADVISORY ACROSS THE
SOUTH END OF THE FCST AREA THRU 7PM/00Z. ONCE THIS PASSES...FCST
TRENDS DRY FOR TONIGHT/SAT AS THE WEAK BUT DRYING HIGH BUILDS
SOUTH INTO MN/WI/IA. STRATO-CU CLOUDS OVER MUCH OF WI/EASTERN MN
CONTINUE TO DIMINISH/BREAK UP WITH DIURNAL WARMING/MIXING THIS
AFTERNOON. LOWER LEVEL ANTI-CYCLONIC FLOW/DIVERGENCE WITH THE HIGH
SHOULD HELP DIMINISH THE CLOUDS AS WELL THIS EVENING. MODELS ALSO
SHOWING MORE 925MB DRYING OVER THE AREA THRU TONIGHT. WILL
CONTINUE TO TREND SKIES TONIGHT TOWARD CLEAR/MOSTLY CLEAR...BUT
THIS THEN POSES A PROBLEM FOR RADIATIONAL FOG DEVELOPMENT AND VERY
LOW STRATUS FORMATION IN THE VALLEYS. BOUNDARY LAYER WIND BECOME
QUITE LIGHT BY MID EVENING. THIS AND DEVELOPMENT OF THE NOCTURNAL
INVERSION LIMIT INFLUX OF DRIER BOUNDARY LAYER AIR...WITH POST-
FRONTAL SFC DEW POINTS LOOKING TO REMAIN IN THE MID/UPPER 60S THIS
EVENING...THEN FALL WITH THE TEMPS OVERNIGHT. THIS ALONG WITH
GENERALLY LIGHT WINDS THRU 850MB REMAINS FAVORABLE FOR LATE
NIGHT/EARLY MORNING FOG. PREVIOUS GRID SET CARRIED PATCHY TO AREAS
OF FOG /MORE SO IN THE RIVER VALLEYS/ IN THE 06Z-14Z TIME FRAME
TONIGHT/SAT MORNING AND THIS CONTINUES TO LOOK GOOD.

ONCE ANY FOG BURNS OFF...A MORE COMFORTABLE DAY IN STORE FOR SAT
WITH DIURNAL WARMING/DEEPER MIXING OF DRIER AIR ALOFT HELPING TO
MIX/HOLD SFC DEW POINTS IN THE 60S. HEAT INDICES SAT LOOKING TO BE
IN THE 80S...VS. THE 90S TO LOW 100S THE PAST FEW DAYS. THE HIGH
GETS QUICKLY PUSHED EAST SAT NIGHT AS THE SFC-MID LEVEL FRONT/TROUGH
APPROACH AND MOVE INTO THE AREA. SFC FRONT ALREADY NEAR A KMDZ-KLSE-
KDSM LINE BY 12Z SUN. PW VALUES INCREASE INTO THE 1.5 TO 1.75 INCH
RANGE WITH THIS TROUGH. STRONGER OF THE DYNAMICS/FORCING/LIFT WITH
THE SHORTWAVE PASS NORTH OF THE FCST AREA...BUT A TIGHTENING/
IMPROVING SIGNAL FOR AT LEAST A MDT ROUND OF LOWER LEVEL THERMO-
DYNAMIC FORCING TO MOVE ACROSS THE AREA LATE SAT NIGHT/SUN MORNING.
THIS ALONG WITH MU CAPE VALUES AROUND 1K J/KG WHEN LIFTING ELEVATED
PARCELS. RAISED SHRA/TSRA CHANCES INTO THE 50-60 PERCENT RANGE FOR
THE FRONTAL APPROACH/PASSAGE LATE SAT NIGHT INTO SUN MORNING. USED A
MODEL/ENSEMBLE CONSENSUS OF THE NUMERICAL GUIDANCE LOWS/HIGHS FOR
TONIGHT THRU SAT NIGHT.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 331 PM CDT FRI AUG 30 2013

MAIN FORECAST CONCERNS FOR SUN THRU MON NIGHT INCLUDE SHRA/TSRA
CHANCES SUN AS THE FRONT MOVES ACROSS THE AREA...TEMPERATURES THRU
THE PERIOD.

MODELS CONTINUE WITH IMPROVING AGREEMENT IN THE SUN-MON NIGHT
PERIOD...FOR WHAT LOOKS TO BE A COOLER/QUIET PERIOD ONCE THE FRONT/
SHRA/TSRA ON SUN EXIT EAST OF THE AREA. TREND SUN THRU MON NIGHT
FAVORS FASTER OF THE EARLIER RUNS WITH THE TROUGH MOVING ACROSS/EAST
OF THE AREA THRU THIS PERIOD. WITH THE TIGHTER CONSENSUS...FAVORED
THE MODEL/ENSEMBLE CONSENSUS.

STRONGER/DEEPER OF LOWER LEVEL THERMO-DYNAMIC FORCING/LIFT TO BE
MOVING ACROSS THE FCST AREA SUN MORNING...ESPECIALLY THE EASTERN
SIDE. CARRIED 40-50+ PERCENT RANGE SHRA/TSRA CHANCES OVER THE
SOUTHEAST 1/2 OF THE FCST AREA SUN MORNING...TRENDING THESE DOWN
THRU THE AFTERNOON AS THE FRONT PUSHES EAST...THE MID LEVEL TROUGH
AXIS PASSES AND COOLER/DRIER CANADIAN HIGH PRESSURE BUILDS IN. DEW
POINTS WITH THIS HIGH/AIRMASS DROP THRU THE 60S SUN...INTO THE 50S
FOR SUN NIGHT/MON/MON NIGHT. TIGHTER SFC PRESSURE GRADIENT BEHIND
THE FRONT SUN COUPLE WITH SOUNDINGS SHOWING MIXING TO 850MB SUN
AFTERNOON...SHOULD MAKE FOR SOME BREEZY/GUSTY NORTHWEST WINDS SUN
AFTERNOON. HIGH CONTINUES TO BUILD SOUTHEAST SUN NIGHT THRU MON
NIGHT...ENDING UP CENTERED OVER WI BY 12Z TUE. 925MB TEMPS IN THE 8C-
12C RANGE MON MORNING...14C-18C RANGE MON AFTERNOON THEN 11C-15C TUE
MORNING. AFTER THE PAST WEEK...SUN NIGHT THRU MON NIGHT LIKELY TO
FEEL ON THE COOL SIDE WITH LOWS IN THE 50S AND HIGHS ONLY IN THE
70S. USED A BLEND OF THE NUMERICAL GUIDANCE FOR HIGHS/LOWS FOR SUN
THRU MON NIGHT.

FOR TUESDAY THROUGH FRIDAY /DAYS 4-7/...
LATEST MEDIUM RANGE MODELS IN DECENT AGREEMENT TUE FOR THE EASTERN
NOAM TROUGHING TO BE PROGRESSIVE WITH RISING HGTS/SHORTWAVE RIDGING
BUILDING OVER THE UPPER MIDWEST. LESSER AGREEMENT ALREADY WED ON A
SHORTWAVE DROPPING DOWN THE EAST SIDE OF CENTRAL NOAM RIDGING...BUT
30.12Z MODEL RUNS IN BETTER AGREEMENT THAN THE 30.00Z RUNS WERE.
SOME DIFFERENCES CONTINUE THU/FRI...WITH ECMWF HOLDING MORE NORTHWEST
FLOW OVER THE REGION AND OVERALL LESS PROGRESSIVE WITH THE FLOW
ACROSS NOAM FOR LATER NEXT WEEK. FCST CONFIDENCE IN THE DAY 4-7
PERIOD IS AVERAGE TO GOOD THIS CYCLE.

THE MODEL DIFFERENCES LOOK TO HAVE MINIMAL IMPACT ON ANY SHRA/TSRA
CHANCES IN THE DAY 4-7 PERIOD...WITH NEXT WEEK TRENDING DRY. MDT/
STRONG CAN HIGH REMAINS OVER THE WESTERN GREAT LAKES TUE...FOR A
DRY/SEASONABLE DAY. MODELS PUSH A WEAKENING COLD FRONT QUIETLY THRU
THE UPPER MIDWEST WED. THIS LOOKS TO BE LITTLE MORE THAN A WIND SHIFT
THAT USHERS IN ANOTHER CAN HIGH PRESSURE SYSTEM...AS MOISTURE/
INSTABILITY REMAIN ON THE LIMITED SIDE. CAN HIGH OF ONE FORM OR
ANOTHER CONTINUES TO BE THE MAIN INFLUENCE ON THE AREAS WEATHER
THU/FRI. WITH NO ONE MODEL SHOWING CLEARLY BETTER RUN-TO-RUN
CONSISTENCY THAN THE OTHERS...DID NOT STRAY FAR FROM THE MODEL/
ENSEMBLE CONSENSUS FOR HIGHS/LOWS IN THE TUE-FRI PERIOD.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1145 PM CDT FRI AUG 30 2013

THE WEAK AREA OF SURFACE HIGH PRESSURE REMAINS OFF TO THE
NORTHEAST OF THE AREA AS A SECONDARY AREA OF LOW PRESSURE HAS
FORMED ALONG THE FRONT OVER SOUTHEAST IOWA. THIS IS HELPING TO
MAINTAIN A GRADIENT WITH EAST TO NORTHEAST WINDS AROUND 5 KNOTS.
DEW POINTS CONTINUE TO DROP IN THIS NORTHEAST FLOW WITH A 14
DEGREE TEMP/DEW POINT SPREAD AT KLSE AT 03Z. CONTINUES TO LOOK
MORE AND MORE UNLIKELY THAT FOG WILL FORM OVERNIGHT AS THE THE
TEMP AND DEW POINT SHOULD CONTINUE TO CHASE EACH OTHER DOWNWARD.
HAVE REMOVED THE IFR FOG FOR BOTH SITES WHILE MAINTAINING SOME
MVFR RESTRICTIONS FOR LATE TONIGHT. THE 31.03Z RAP CONTINUES TO
SUGGEST AN MVFR CLOUD DECK ADVECTING IN FROM THE EAST BUT NOW
TAKES THIS MOISTURE A LITTLE FARTHER SOUTH THAN PREVIOUS RUNS HAD
SHOWN. MVFR CEILINGS ARE IN PLACE ACROSS SOUTHEAST WISCONSIN AND
HAVE OPTED TO LEAVE THIS POSSIBILITY IN DUE TO THE CLOSE PROXIMITY
OF THESE IN THE LOW LEVEL EAST FLOW. ONCE CONDITIONS MIX OUT
SATURDAY MORNING...VFR CONDITIONS EXPECTED FOR THE REMAINDER OF
THE PERIOD.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

UPDATE...04
SHORT TERM...RRS
LONG TERM....RRS
AVIATION...04







AREA FORECAST DISCUSSION...UPDATE

NWS MILWAUKEE/SULLIVAN WI

 1115 PM CDT FRI AUG 30 2013

.UPDATE...NELY FLOW AND LOW LEVEL COLD ADVECTION UNDERWAY. 60
DEWPOINTS ON COOL SIDE OF FRONT IS AIDING STRATUS DEVELOPMENT OVER
MUCH OF THE GREAT LAKES INTO SRN WI. STRATUS AND SOME WINDS SHOULD
KEEP ANY FOG ON THE LIGHT SIDE. TEMPS WILL REBOUND ON SAT AFTER
STRATUS AND FOG BURN OFF WITH HIGHS IN THE MID TO UPPER 70S LAKESIDE
TO LOWER TO MID 80S WELL INLAND.

&&

.AVIATION/06Z TAFS/...BROKEN STRATUS FROM 1.0-3.0 KFT IS EXPECTED
UNTIL LATE SAT AM OR EARLY AFTERNOON. AREAS OF MVFR AND IFR VSBYS
WILL OCCUR EARLY SAT AM AND IMPROVE BY 15Z. OTHERWISE VFR CONDITIONS
EXPECTED FOR SAT AFTERNOON INTO THE EVENING.

&&


.PREV DISCUSSION... /ISSUED 354 PM CDT FRI AUG 30 2013/

VERY SHORT TERM...TONIGHT AND SATURDAY.

TONIGHT - CONFIDENCE...MEDIUM
PLENTY OF CAPE POOLING AHEAD OF SOUTHWARD MOVING FRONTAL BOUNDARY.
STORMS ARE ORGAN ZING AS BEST AS THEY CAN GIVEN THE LACK OF DECENT
0-6KM SHEAR AND SUSPECT MID LEVEL LAPSE RATES. HOWEVER PLENTY OF
CAPE IN THE LOW LEVELS WITH GOOD LOW LEVEL LAPSE RATES WITH
SURFACE/925 CONVERGENCE ALLOWING FOR SOME STRONGER WINDS AND HAIL.
WATER VAPOR/RUC COMBO DOES SHOW A WEAK UPSTREAM WAVE RIDING IN
FROM SRN MN AND NRN IA. HRRR SHOWING STORMS CLEARING THE FAR SOUTH
AROUND 00Z OR SO. HOWEVER 4KM WRF-SPC AND 12Z ECMWF LINGER PRECIP
ACROSS PORTIONS OF SC WI DEEPER INTO THE EVENING. BASED ON FRONTAL
PROGRESSION WILL BANK ON A QUICKER EXIT OF PRECIP BASED ON OTHER
MODELS. SO FRONTAL BOUNDARY EXITS TO THE SOUTH THIS EVENING TAKING
ANY LINGERING STORMS WITH IT. WILL RETAIN HEAT ADVISORY FOR SOUTHERN
TIER ONLY AS I-94 CORRIDOR AFFECTED BY OUTFLOW AND STORMS.
SURFACE/925 COOL AIR ADVECTION THEN TAKES HOLD. NOT SO MUCH UP TO
850 MILLIBARS...BUT FROM 925 AND ON DOWN PRETTY STRONG SIGNAL AND
THIS IS PLAUSIBLE GIVEN CONDITIONS UPSTREAM IN NORTHERN WISCONSIN.
EXPECTING COOLER AND DRIER DEW POINTS TO ADVECT INTO THE AREA WITH
THE EVOLVING POST-FRONTAL NORTH WINDS. LOW LEVEL WIND FLOW/DEGREE OF
MIXING SUGGESTS THE EVOLUTION OF DENSE FOG NOT LIKELY. LOOKS MORE
LIKE STRATUS POTENTIAL.

SATURDAY - CONFIDENCE...MEDIUM HIGH PRESSURE SETTLES IN. MORNING
FOG/LOW STRATUS POTENTIAL WILL GRADUALLY BURN OFF. NOT A BIG
DROP OFF IN 850 TEMPS. NEVERTHELESS CU RULE SUPPORTIVE OF SCT
COVERAGE AFTER MORNING STRATUS. 925 TEMPS PROGGD TO 20-23C.
COMFORTABLY COOLER AND LESS HUMID. SO LOW TO MID 80S WITH
MID/UPPER 70S IN THE FAR EAST WITH THE SUSTAINED ONSHORE FLOW.

SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.

SATURDAY NIGHT AND SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH.

NEXT BEST CHANCE OF PRECIPITATION COMES WITH SHORT WAVE TROUGH AND
COLD FRONT. STILL SOME DIFFERENCES IN CONFIGURATION OF SHORT WAVE
THAT IMPACTS TIMING OF SURFACE TROUGH/COLD FRONT THROUGH REGION.
WILL GO WITH BLENDED SOLUTION THAT BRINGS A CHANCE TO THE NW CWA
BETWEEN 06Z AND 12Z SUNDAY...THEN HIGH CHANCE POPS ACROSS THE
ENTIRE FORECAST AREA DURING THE DAY SUNDAY. SHOULD SEE LOW TO MID
80S HIGHS PRIOR TO ONSET OF PCPN.

SUNDAY NIGHT AND MONDAY...FORECAST CONFIDENCE HIGH.

PRECIPITATION CHANCES LINGER INTO SUNDAY EVENING IN THE EAST WITH
HIGH PRESSURE BUILDING IN BEHIND. LABOR DAY MORE FALL-LIKE WITH
LOW TO MID 70 HIGHS.

LONG TERM...MONDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE
MEDIUM TO HIGH.

DRY WEATHER AS HIGH PRESSURE DOMINATES THE WESTERN GREAT LAKES REGION
UNDER NORTHWEST FLOW REGIME. MODELS TRY TO BRUSH SW/SOUTHERN CWA
WITH LIGHT QPF WITH A WEAK WAVE/WARM AIR ADVECTION BUT FOR NOW
WILL LEAVE DRY. BELOW NORMAL TEMPERATURES WILL WARM BACK TOWARD
NORMAL LEVELS...OR SLIGHTLY ABOVE...WEDNESDAY THROUGH THE REST OF
THE EXTENDED.

AVIATION/00Z TAFS/...

THUNDERSTORM POTENTIAL THROUGH 00Z WITH FRONTAL BOUNDARY DROPPING
IN FROM THE NORTH. WINDS WILL SHIFT TO THE NORTH IN THE WAKE OF
THE FRONT WITH THE EVENING FROPA. WILL MONITOR STRATUS TRENDS IN
THE COOL ADVECTION REGIME. EXPECT MVFR CEILINGS AND POTENTIAL FOR
IFR LATER TONIGHT INTO EARLY SATURDAY. THINKING ENOUGH MIXING WILL
INHIBIT DENSE FOG FORMATION.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&

$$

UPDATE...GEHRING
TONIGHT/SATURDAY AND AVIATION/MARINE...COLLAR
SATURDAY NIGHT THROUGH FRIDAY...REM










AREA FORECAST DISCUSSION

NWS PUEBLO CO

 149 AM MDT MON SEP 2 2013

.UPDATE...
ISSUED AT 145 AM MDT MON SEP 2 2013

BROUGHT FRONT END GRIDS INTO ALIGNMENT WITH CURRENT OBSERVATIONS
AND TRENDS. NO MAJOR UPDATES TO OVERALL FORECAST AT THIS TIME. LW

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 226 PM MDT SUN SEP 1 2013

ABUNDANT MOISTURE IS OVER THE AREA TODAY.  THE MONSOON PLUME LIES
OVERHEAD AND SFC DEW POINTS RANGE FROM THE UPR 40S TO LOWER 60S ACRS
MOST OF THE AREA...AND LCL/S ARE LOWER TODAY...ALL LEADING TO A
BETTER POTENTIAL FOR HEAVY RAINFALL TODAY. LOW LEVEL UPSLOPE FLOW
COULD HELP ENHANCE CONVECTION ALONG AND NR THE MTS AND COULD LEAD TO
A TRAINING EFFECT.  THE UPR LEVEL FLOW IS NORTHWESTERLY AROUND 15
KTS SO IN GENERAL THE STORMS SHOULD MOVE TOWARD THE SOUTHEAST THIS
EVENING.  SHOWERS AND TSTMS OVER THE MOUNTAINS EARLY THIS AFTERNOON
SHOULD INCREASE IN COVERAGE AND SPREAD TO THE LOWER ELEVATIONS.
HOWEVER THE NAM12 AND RAP13 SHOW LITTLE CONVECTION OUT OVR THE SERN PLAINS
THIS EVENING AND QUICKLY END PCPN BY MIDNIGHT OVR ALL AREAS EXCEPT
ALONG THE CONTDVD.  THE HRRR SHOWS A LINE OF CONVECTION MOVING OUT
OVR THE SERN PLAINS EARLY IN THE EVENING BUT DOESN/T REALLY MOVE IT
PAST LA JUNTA.

OVERNIGHT THE MODELS SHOW THE MONSOON MSTR PLUME SHIFTING SOUTH OF
THE AREA...AND THEN ON MON THAT PLUME IS EXPECTED TO BE OVR THE
MOUNTAIN AREAS...WITH DRIER UPR LEVELS FROM THE I-25 CORRIDOR AND
WESTWARD. AT THE LOWER LEVELS DEW POINTS ARE STILL EXPECTED TO
REMAIN FAIRLY HIGH...IN THE UPPER 40S AND 50S.  LCL/S ARE EXPECTED
TO BE A LITTLE HIGHER ON MON.  BEST CHANCES FOR PCPN ON MON WL BE
OVR THE NR THE MTS...WITH SOME STORMS LIKELY MOVING OUT OVR THE I-25
CORRIDOR...BUT MUCH OF THE REST OF THE PLAINS COULD BE DRY. WE COULD
AGAIN SEE SOME LOCALLY HEAVY RAIN ON MON AND IF ANY OF THESE
STRONGER STORMS MOVE OVER THE BURN SCARS...THERE WL AGAIN BE THE
THREAT OF FLASH FLOODING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 226 PM MDT SUN SEP 1 2013

UPPER LEVEL HIGH PRESSURE WILL REMAIN CENTERED OVER COLORADO THROUGH
AT LEAST FRIDAY. UPPER LOW SLOWLY MOVES ONSHORE IN THE PACIFIC
NORTHWEST FRIDAY/SATURDAY TIMEFRAME. MODELS A BIT SLOWER WITH THIS
FEATURE THAN RUNS FROM 24 HOURS AGO...LIKELY DUE TO THE BLOCKINESS
OF THE PATTERN.

THIS DOMINANT RIDGE MEANS A RETURN TO UNSEASONABLY WARM CONDITIONS.
THUNDERSTORM CHANCES THROUGH THE WORK WEEK WILL BE PRIMARILY
CONFINED TO THE MOUNTAINS AND WEST...ALTHOUGH MODELS HINT AT A SUBTLE
UPPER DISTURBANCE MOVING THROUGH THE HIGH PLAINS AND SENDING A WEAK
FRONTAL BOUNDARY THROUGH THE EAST CENTRAL PLAINS WEDNESDAY AFTERNOON
WHICH COULD TRIGGER SOME CONVECTION ON THE PALMER DIVIDE. LITTLE IN
THE WAY OF MID AND UPPER LEVEL MOISTURE THOUGH...SO FLASH FLOOD
THREAT WILL BE LOWER.

RIDGE GETS FLATTENED AND AXIS SHUNTED OFF TO THE EAST SATURDAY NIGHT
AND SUNDAY AS LOW PRESSURE MOVES EAST ALONG THE US/CANADIAN BORDER.
COULD SEE A DECENT COLD FRONT MOVE THROUGH THE PLAINS NEXT WEEKEND
IF THE MODELS REMAIN CONSISTENT WITH THE TIMING OF THIS SYSTEM. IF
SO, COOLER TEMPERATURES AND A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS ARE POSSIBLE SOMETIME NEXT WEEKEND.

IN THE MEANTIME, DESPITE TEMPERATURES WARMING TO ABOVE NORMAL LEVELS
THIS WEEK...GUIDANCE NUMBERS REMAIN TOO WARM. WILL CONTINUE TREND OF
SHAVING A FEW DEGREES OFF GUIDANCE HIGHS. STARK

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1119 PM MDT SUN SEP 1 2013

WEAK SOUTHEAST SURFACE WINDS HAVE HELPED STRATUS DEVELOP AT KCOS
AND KFLY AS OF 05Z...AND EXPECT MVFR STRATUS TO PERSIST ALONG AND
SOUTH OF THE PALMER DIVIDE...INCLUDING KCOS...UNTIL AROUND 15Z.
SUSPECT LOWER CLOUDS WILL STAY NORTH OF KPUB...SO WILL CONTINUE
WITH VFR CONDITIONS HERE THROUGH SUNRISE. OVER THE
MOUNTAINS...PATCHY MVFR CIGS/VIS WITH WEAKENING -SHRA WILL PERSIST
THROUGH 07-09Z...WITH MOST MOUNTAINS CLEARING BY 12Z. ON
MON...TSRA WILL AGAIN DEVELOP OVER THE MOUNTAINS AFTER 18Z...BEST
CHANCES WILL BE SOUTHERN SANGRES...SAN JUANS AND AREAS NEAR THE NM
BORDER. TAF SITES WILL STAY VFR THROUGH THE DAY...THOUGH THERE IS
A HIGH ENOUGH CHANCE OF A TSRA AT KALS TO INCLUDE A VCTS AFTER
20Z. TSRA CHANCES AT KPUB AND KCOS ARE NON-ZERO...BUT LOOK TOO LOW
TO INCLUDE IN THE TAF AT THIS POINT.


&&

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...LW
SHORT TERM...28
LONG TERM...STARK
AVIATION...PETERSEN







AREA FORECAST DISCUSSION

NWS PUEBLO CO

 1126 PM MDT SUN SEP 1 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 226 PM MDT SUN SEP 1 2013

ABUNDANT MOISTURE IS OVER THE AREA TODAY.  THE MONSOON PLUME LIES
OVERHEAD AND SFC DEW POINTS RANGE FROM THE UPR 40S TO LOWER 60S ACRS
MOST OF THE AREA...AND LCL/S ARE LOWER TODAY...ALL LEADING TO A
BETTER POTENTIAL FOR HEAVY RAINFALL TODAY. LOW LEVEL UPSLOPE FLOW
COULD HELP ENHANCE CONVECTION ALONG AND NR THE MTS AND COULD LEAD TO
A TRAINING EFFECT.  THE UPR LEVEL FLOW IS NORTHWESTERLY AROUND 15
KTS SO IN GENERAL THE STORMS SHOULD MOVE TOWARD THE SOUTHEAST THIS
EVENING.  SHOWERS AND TSTMS OVER THE MOUNTAINS EARLY THIS AFTERNOON
SHOULD INCREASE IN COVERAGE AND SPREAD TO THE LOWER ELEVATIONS.
HOWEVER THE NAM12 AND RAP13 SHOW LITTLE CONVECTION OUT OVR THE SERN PLAINS
THIS EVENING AND QUICKLY END PCPN BY MIDNIGHT OVR ALL AREAS EXCEPT
ALONG THE CONTDVD.  THE HRRR SHOWS A LINE OF CONVECTION MOVING OUT
OVR THE SERN PLAINS EARLY IN THE EVENING BUT DOESN/T REALLY MOVE IT
PAST LA JUNTA.

OVERNIGHT THE MODELS SHOW THE MONSOON MSTR PLUME SHIFTING SOUTH OF
THE AREA...AND THEN ON MON THAT PLUME IS EXPECTED TO BE OVR THE
MOUNTAIN AREAS...WITH DRIER UPR LEVELS FROM THE I-25 CORRIDOR AND
WESTWARD. AT THE LOWER LEVELS DEW POINTS ARE STILL EXPECTED TO
REMAIN FAIRLY HIGH...IN THE UPPER 40S AND 50S.  LCL/S ARE EXPECTED
TO BE A LITTLE HIGHER ON MON.  BEST CHANCES FOR PCPN ON MON WL BE
OVR THE NR THE MTS...WITH SOME STORMS LIKELY MOVING OUT OVR THE I-25
CORRIDOR...BUT MUCH OF THE REST OF THE PLAINS COULD BE DRY. WE COULD
AGAIN SEE SOME LOCALLY HEAVY RAIN ON MON AND IF ANY OF THESE
STRONGER STORMS MOVE OVER THE BURN SCARS...THERE WL AGAIN BE THE
THREAT OF FLASH FLOODING.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 226 PM MDT SUN SEP 1 2013

UPPER LEVEL HIGH PRESSURE WILL REMAIN CENTERED OVER COLORADO THROUGH
AT LEAST FRIDAY. UPPER LOW SLOWLY MOVES ONSHORE IN THE PACIFIC
NORTHWEST FRIDAY/SATURDAY TIMEFRAME. MODELS A BIT SLOWER WITH THIS
FEATURE THAN RUNS FROM 24 HOURS AGO...LIKELY DUE TO THE BLOCKINESS
OF THE PATTERN.

THIS DOMINANT RIDGE MEANS A RETURN TO UNSEASONABLY WARM CONDITIONS.
THUNDERSTORM CHANCES THROUGH THE WORK WEEK WILL BE PRIMARILY
CONFINED TO THE MOUNTAINS AND WEST...ALTHOUGH MODELS HINT AT A SUBTLE
UPPER DISTURBANCE MOVING THROUGH THE HIGH PLAINS AND SENDING A WEAK
FRONTAL BOUNDARY THROUGH THE EAST CENTRAL PLAINS WEDNESDAY AFTERNOON
WHICH COULD TRIGGER SOME CONVECTION ON THE PALMER DIVIDE. LITTLE IN
THE WAY OF MID AND UPPER LEVEL MOISTURE THOUGH...SO FLASH FLOOD
THREAT WILL BE LOWER.

RIDGE GETS FLATTENED AND AXIS SHUNTED OFF TO THE EAST SATURDAY NIGHT
AND SUNDAY AS LOW PRESSURE MOVES EAST ALONG THE US/CANADIAN BORDER.
COULD SEE A DECENT COLD FRONT MOVE THROUGH THE PLAINS NEXT WEEKEND
IF THE MODELS REMAIN CONSISTENT WITH THE TIMING OF THIS SYSTEM. IF
SO, COOLER TEMPERATURES AND A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS ARE POSSIBLE SOMETIME NEXT WEEKEND.

IN THE MEANTIME, DESPITE TEMPERATURES WARMING TO ABOVE NORMAL LEVELS
THIS WEEK...GUIDANCE NUMBERS REMAIN TOO WARM. WILL CONTINUE TREND OF
SHAVING A FEW DEGREES OFF GUIDANCE HIGHS. STARK

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1119 PM MDT SUN SEP 1 2013

WEAK SOUTHEAST SURFACE WINDS HAVE HELPED STRATUS DEVELOP AT KCOS
AND KFLY AS OF 05Z...AND EXPECT MVFR STRATUS TO PERSIST ALONG AND
SOUTH OF THE PALMER DIVIDE...INCLUDING KCOS...UNTIL AROUND 15Z.
SUSPECT LOWER CLOUDS WILL STAY NORTH OF KPUB...SO WILL CONTINUE
WITH VFR CONDITIONS HERE THROUGH SUNRISE. OVER THE
MOUNTAINS...PATCHY MVFR CIGS/VIS WITH WEAKENING -SHRA WILL PERSIST
THROUGH 07-09Z...WITH MOST MOUNTAINS CLEARING BY 12Z. ON
MON...TSRA WILL AGAIN DEVELOP OVER THE MOUNTAINS AFTER 18Z...BEST
CHANCES WILL BE SOUTHERN SANGRES...SAN JUANS AND AREAS NEAR THE NM
BORDER. TAF SITES WILL STAY VFR THROUGH THE DAY...THOUGH THERE IS
A HIGH ENOUGH CHANCE OF A TSRA AT KALS TO INCLUDE A VCTS AFTER
20Z. TSRA CHANCES AT KPUB AND KCOS ARE NON-ZERO...BUT LOOK TOO LOW
TO INCLUDE IN THE TAF AT THIS POINT.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...28
LONG TERM...STARK
AVIATION...PETERSEN







AREA FORECAST DISCUSSION...UPDATED

NWS PEACHTREE CITY GA

 135 AM EDT MON SEP 2 2013

.PREV DISCUSSION... /ISSUED 928 PM EDT SUN SEP 1 2013/

UPDATE...NEXT IN A SERIES OF SHORTWAVES IN NORTHWEST FLOW ALOFT
PUSHED THROUGH THE FORECAST AREA THIS EVENING WITH A NEARLY
CONTINUOUS LINE AFFECTING THE ATLANTA METRO AND POINTS SOUTHWARD.
ONLY ISOLATED REPORTS OF TREES DOWN HOWEVER AS ACTIVITY WAS
LARGELY BENIGN DESPITE ITS ORGANIZED STRUCTURE. ACTIVITY HAS
SUBSIDED SIGNIFICANTLY BUT ADDITIONAL SHORTWAVE ENERGY UPSTREAM
ALREADY PRODUCING ACTIVITY OVER TENNESSEE AT THIS HOUR. HRRR AND
LOCAL WRF BOTH SHOWING POSSIBLE DEVELOPMENT INTO THE OVERNIGHT
HOURS BUT DIFFER ON EXACT TIMING. FOR NOW...WILL LEAVE GRIDS AS
THEY STAND WHICH BRINGS CHANCE POPS BACK TO THE NORTH JUST PRIOR
TO DAYBREAK. NO CHANGES PLANNED AT THIS TIME.

DEESE

PREV DISCUSSION... /ISSUED 755 PM EDT SUN SEP 1 2013/

PREV DISCUSSION... /ISSUED 339 PM EDT SUN SEP 1 2013/

SHORT TERM /TONIGHT THROUGH MONDAY/...
UPPER TROUGH DEEPENS OVER THE GREAT LAKES THROUGH TOMORROW. SEVERAL
RIPPLES NOTED IN THE UPPER LEVEL FLOW TODAY ENHANCING CONVECTION.
SHORT TERM HIRES MODELS NOT HANDLING CURRENT CONVECTION WELL. GOOD
MOISTURE...AND INSTABILITY NOTED ACROSS THE FORECAST AREA...CAPES
APPROACHING 2000...AS AN OUT FLOW BOUNDARY FROM THIS MORNINGS
CONVECTION ACROSS NORTH GA...AIDED IN THE DEVELOPMENT OF A LINE OF
SHOWERS AND THUNDERSTORMS FROM CARROLLTON TO ATLANTA TO ATHENS.
THIS LINE WILL SAG SLOWLY SOUTHWARD THROUGH THIS EVENING. HRRR
HINTING AT ANOTHER LINE DEVELOPING OVER EASTER AL JUST BEFORE
SUNSET IMPACTING PORTIONS OF WEST AND CENTRAL GA THROUGH LATE
EVENING...WITH THE AREA ALREADY WORKED OVER AM NOT BITING ON THIS
SOLUTION AT THIS TIME. WILL CONTINUE TO SHOW CONVECTION SHIFTING
TO THE SOUTH SIDE OF ATL TO AHN AFTER 4-5PM AND IMPACTING CSG-MCN
BETWEEN 6-9 PM.

MODELS SHOWING MOISTURE AND INSTABILITY LINGERING OVERNIGHT...AND
ISOLATED STORMS WILL CONTINUE TO BE POSSIBLE. ECMWF/GFS/NAM ALL
SHOWING MCS POSSIBLE BY 12Z MONDAY NOW AND HAVE CONTINUED CHANCE
POPS ACROSS NORTH GEORGIA TO ACCOUNT FOR THE FEATURE. WEAK SURFACE
FRONT CONTINUES TO APPROACH NORTH GEORGIA TOMORROW AND WITH GOOD
MOISTURE AND INCREASING INSTABILITY ONCE AGAIN EXPECT SCATTERED
SHOWERS/THUNDERSTORMS ACROSS THE AREA ON MONDAY.

CONTINUED TO USE A BIAS CORRECTED BLEND OF GUIDANCE TEMPERATURES
ACROSS THE AREA THROUGH THE SHORT TERM PERIODS...ALTHOUGH MAX
TEMPERATURES MONDAY WILL BE HIGHLY DEPENDENT ON THE AMOUNT OF LOW
LEVEL CLOUDS THAT ARE ABLE TO DEVELOP IN RAIN SOAKED AREAS TONIGHT.

ATWELL

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ONLY MINOR TWEAKS MADE TO THE EXTENDED. DID RAISE TEMPERATURES FOR
SATURDAY/SUNDAY A DEGREE OR SO BUT STILL LOOKING LIKE THE COOLEST
DAYS OF EXTENDED PERIOD.
PREV DISCUSSION... /ISSUED 324 AM EDT SUN SEP 1 2013/
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE EXTENDED BEGINS WITH AN UPPER LOW OVER SOUTHERN ONTARIO...
TROUGHING DOWN THE EASTERN THIRD OF THE U.S...WITH THE ASSOCIATED
COLD FRONT PUSHING THROUGH THE SOUTHEAST. PRECIP CHANCES CONTINUE
ACROSS THE STATE MONDAY NIGHT BUT AS THE FRONT PUSHES TOWARD THE
COAST TUESDAY AND TUESDAY NIGHT...DRIER AIR FILTERS IN BEHIND IT
AND PUSHES PRECIP CHANCES INTO CENTRAL AND SOUTH GEORGIA. DRIEST
DAY LOOKS TO BE WEDNESDAY AS THE TROUGH AXIS SHIFTS EAST OFF THE
COAST AND HIGH PRESSURE DOMINATES MOST OF THE STATE. HOWEVER...ON
THURSDAY ANOTHER SHORTWAVE ROUNDS THE BASE OF THE TROUGH AND LOOKS
TO PROVIDE ENOUGH LIFT THAT WHEN COMBINED WITH OROGRAPHIC LIFTING
IS ENOUGH TO WARRANT SLIGHT TO LOW CHANCE POPS IN THE NORTHEAST
MOUNTAINS. ECMWF IS A LITTLE STRONGER WITH THIS SHORTWAVE
INITIALLY BUT BOTH MODELS IN REASONABLE AGREEMENT WITH THIS
FEATURE ON FRIDAY. AS WE PUSH INTO THE WEEKEND...THE GFS IS
DEFINITELY THE WETTER OF THE TWO MODELS SO COMPROMISED ON THIS
UNCERTAINTY BY PAINTING GENERALLY SLIGHT CHANCE POPS ACROSS THE
AREA ON SATURDAY.

AS FOR TEMPS...TUESDAY WILL CONTINUE THE TREND OF ABOVE-NORMAL
TEMPS...AND EVEN WITH THE FRONTAL PASSAGE TEMPS WILL ONLY DROP A
COUPLE OF DEGREES BUT SHOULD BE NEAR SEASONAL NORMALS. THE MORE
NOTICEABLE CHANGE WILL BE IN OVERNIGHT LOWS...LIKELY DROPPING AT
LEAST 5 DEGREES BETWEEN MONDAY NIGHT AND WEDNESDAY NIGHT. SATURDAY
IS A BIT FAR OUT THERE BUT WITH THE INFLUENCE OF THE STRONG
SHORTWAVE /INCREASED CLOUDINESS/...RIGHT NOW THAT LOOKS TO BE THE
COOLEST DAY OF THE PERIOD.

TDP

&&

.AVIATION...
06Z UPDATE...
SEEING SOME PATCHY MVFR FOG AT TAF TIME...THIS SHOULD INCREASE IN
COVERAGE THROUGH THE MORNING HOURS AND EXPECT LOW MVFR CIGS TO
DEVELOP AS WELL. CIGS SHOULD BEGIN LIFTING AFTER SUNRISE...WITH
TSRA CHANCES INCREASING DURING THE AFTERNOON. FOR NOW LEFT PROB30
IN BUT DEPENDING ON HOW TRENDS GO THIS MORNING MAY NEED TO
INCREASE WORDING TO PREVAILING. SOME HINTS AT MVFR CIGS AGAIN
TUESDAY MORNING BUT DRIER AIR WILL BE MOVING IN SO NOT CONFIDENT
IN THAT AND HAVE ONLY HINTED WITH BKN030 FOR ATL AT THIS TIME.
WIND SW TO W THROUGH THE PERIOD...LIGHT OVERNIGHT AND 4-8KT DURING
THE DAY...EXCEPT GUSTY IN THUNDERSTORMS.

//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON CIGS/VSBY THIS MORNING.
HIGH ON OCCURRENCE OF CONVECTION...MEDIUM ON IMPACTS TO ATL.
LOW ON CIGS TUESDAY MORNING.
HIGH ON WINDS.

TDP

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          90  72  90  68 /  60  40  30  20
ATLANTA         90  74  90  69 /  60  40  30  20
BLAIRSVILLE     84  68  84  62 /  60  60  20  20
CARTERSVILLE    89  71  90  66 /  70  50  20  10
COLUMBUS        93  74  90  71 /  50  40  40  20
GAINESVILLE     88  73  89  67 /  60  50  30  20
MACON           91  72  91  69 /  40  30  40  20
ROME            90  72  90  66 /  70  60  20  10
PEACHTREE CITY  90  71  89  67 /  50  40  30  20
VIDALIA         93  74  90  73 /  40  30  40  30

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...ATWELL
LONG TERM....ATWELL
AVIATION...TDP






AREA FORECAST DISCUSSION

NWS GOODLAND KS

 1100 PM MDT SUN SEP 1 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 207 PM MDT SUN SEP 1 2013

LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE BEGINNING TO
RETREAT TOWARD THE FOUR CORNERS REGION WITH POSITIVELY TILTED
TROUGH MIGRATING INTO THE NORTHERN GREAT LAKES REGION. STRONG
SUBSIDENCE IS EVIDENT ACROSS THE NORTHERN PLAINS...AND IS
BEGINNING TO OVERSPREAD OUR CWA FROM THE NORTH-NORTHEAST. AT THE
SURFACE HIGH PRESSURE HAS SETTLED OVER OUR CWA WITH COLD FRONT NOW
ALONG FRONT RANGE EXTENDING SOUTH ACROSS TEXAS PANHANDLE.

THERE HAVE BEEN A FEW LIGHT SHOWERS SLOWLY MOVING ACROSS THE
PLAINS OF EASTERN COLORADO AND LATEST RAP/HRRR SHOW THIS ACTIVITY
FALLING APART THROUGH SUNRISE. AT THIS POINT I AM NOT CONFIDENT WE
WILL SEE ANY MEASURABLE PRECIP OUT OF THIS WITH STABLE/DRY AIR
SPREADING WEST...SO I WILL KEEP MENTION OUT THROUGH THE REMAINDER
OF THE AFTERNOON. WITH STABLE AIR MASS IN PLACE AND SUBSIDENCE
BUILDING IN ALOFT...I AM ANTICIPATING DRY CONDITIONS THROUGH
MONDAY.

REGARDING TEMPS...COOLER AIR MASS REMAINS IN PLACE OVERNIGHT...AND
WITH LOW TD VALUES (45-50F) ADVECTING SOUTH THROUGH THIS EVENING
AND CLEAR/CALM CONDITIONS WE SHOULD SEE VERY GOOD RADIATIONAL
COOLING. I TRIMMED TEMPS A LITTLE WITH LOWS AT SOME LOCATIONS IN
THE LOW 50S. H5 RIDGE WILL BEGIN TO BUILD BACK TO THE EAST MONDAY
AND LEE TROUGH WILL BEGIN TO STRENGTHEN. WE SHOULD SEE WAA ALOFT
WITH UNIDIRECTIONAL SOUTHERLY FLOW...AND HIGHS ABOUT 3-4F WARMER
THAN TODAY (UPPER 80S/NEAR 90F).

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 221 PM MDT SUN SEP 1 2013

FROM MONDAY NIGHT THROUGH SATURDAY...THE UPPER HIGH PRESSURE
CENTER REMAINS OVER THE CENTRAL ROCKIES AND CENTRAL HIGH PLAINS
REGIONS. BY NEXT SUNDAY...THE UPPER LOW CENTER THAT HAS BEEN SLOWLY
MOVING INTO THE PACIFIC NORTHWEST MOVES ACROSS THE NORTHERN
ROCKIES AND NORTHERN HIGH PLAINS...PUSHING THE UPPER TROUGH AXIS
FURTHER EAST OVER THE PLAINS AND WESTERN GREAT LAKES
REGIONS AND TURNING THE FLOW ALOFT TO THE SOUTHWEST ACROSS THE
FORECAST AREA.

THE SURFACE HIGH PRESSURE AREA IN PLACE OVER THE PLAINS STATES
MOVES FURTHER TO THE EAST AS THE SURFACE TROUGH MOVES INTO
POSITION NEAR THE EASTERN COLORADO BORDER BY WEDNESDAY MORNING. A
WEAK SURFACE TROUGH REMAINS NEARLY STATIONARY OVER THE EASTERN
COLORADO BORDER THROUGH SUNDAY WITH MAINLY WESTERLY FLOW ALOFT
OVER THE ROCKIES. DURING THIS TIME...ISOLATED SHOWERS AND THUNDERSTORMS
ARE EXPECTED TO DEVELOP OVER THE HIGHER TERRAIN TO THE WEST EACH
AFTERNOON WITH A STRAY STORM OR TWO MOVING INTO THE WESTERN
PORTION OF THE FORECAST AREA LATE EACH DAY. OTHERWISE...HAVE KEPT
THE EXTENDED FORECAST PERIOD DRY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM MDT SUN SEP 1 2013

FOR KGLD AND KMCK VFR THROUGH THE PERIOD. SFC HIGH TO MOVE THROUGH
SUNRISE PROVIDING FOR LIGHT/VARIABLE WINDS. PRESSURE GRADIENT
INCREASES DURING THE DAY MONDAY LEADING TO SOUTHERLY WINDS GUSTING
NEAR 25KTS AT KGLD BY 17Z AND CONTINUING THROUGH THE REST OF THE
TAF PERIOD BEFORE LOSING THE GUSTINESS AFTER 01Z. FOR KMCK
SOUTH/SOUTHEAST WIND AROUND 10KTS EXPECTED BY 16Z AND CONTINUING
THROUGH THE REST OF THE TAF PERIOD.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

SHORT TERM...DR
LONG TERM...LOCKHART
AVIATION...99







AREA FORECAST DISCUSSION

NWS PADUCAH KY

 345 AM CDT Mon Sep 2 2013

.SHORT TERM...(Today through Wednesday)
ISSUED AT 345 AM CDT MON SEP 2 2013

Cold front early this a.m. was approaching the NW part of our CWFA.
Near calm and saturated surface conditions allowing for areas of
fog especially SRN IL / SEMO where temps crossed over and are in the
upper 60s. Nothing on radar to speak of. Will keep conditions
convection free through the early morning hours. By 15-16z, the
NAM and HRRR drop the front to about the Ohio River with
instability developing ahead of it. Cannot rule out isolated
convection along and ahead of the front mainly over WKY late
morning through the afternoon, given the weak convergence, slight
steepening of mid level lapse rates and modest surface based
instability. Should anything get going, that chance will shift
south and east through late afternoon, followed by a gradual
lowering of humidity from the NW in the wake of the front.

Quiet, cooler weather tonight through Wednesday as high pressure
takes control and builds southward. For temps we used a blend of
MOS and bias corrected model input.

.LONG TERM...(Wednesday night through Monday)
ISSUED AT 345 AM CDT MON SEP 2 2013

At this time, the extended forecast period is a dry forecast.  A
westward tilted ridge of high pressure with height persists over the
WFO PAH forecast area, with scant low level moisture available. The
only "ripple" in the forecast late next Sunday into Sunday night,
when there is a slightly troughiness that develops along the east
side of the mid-upper level ridge. However, given that this is such
a low PoP event in the first place, confidence is pretty low for any
measurable precipitation.

With northwest flow aloft east of the upper ridge and little in the
way of any significant changes in thickness values, kept
temperatures in the middle 80s to around 90 for nearly all of the
forecast period.

&&

.AVIATION...
ISSUED AT 345 AM CDT MON SEP 2 2013

Fog will remain a concern through daybreak with little wind. Best
chance of convection later today will generally be across west KY.
Chances appear too low to include in the TAF forecasts. We will see
winds come around to the NW in the wake of the front aob 10 kts.
Light north winds tonight with few clouds.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$









AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON KY

 350 AM EDT MON SEP 2 2013

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM EDT MON SEP 2 2013

07Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING THROUGH THE OHIO VALLEY
WITH A COLD FRONT PRESSING INTO KENTUCKY FROM THE NORTHWEST. ON THE
OTHER SIDE OF THAT BOUNDARY COOLER AND MUCH DRIER AIR IS FOUND. EAST
KENTUCKY IS ON THE OPPOSITE SIDE GIVING US ANOTHER MUGGY AND MILD
NIGHT WITH TEMPS AND DEWPOINTS WITHIN A FEW DEGREES OF 70. PLENTY OF
LOW LEVEL MOISTURE IS KEEPING SOME LOW LEVEL CLOUDS AROUND IN
ADDITION TO SUPPORTING THE DEVELOPMENT OF PATCHY VALLEY FOG...BUT THE
CONVECTION HAS REMAINED AT BAY.

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM. THEY
ALL TAKE A DECENT...FOR LATE SUMMER...TROUGH THROUGH THE GREAT LAKES
AND OHIO VALLEY FROM TODAY INTO TUESDAY. THIS WILL SUPPORT LOW
HEIGHTS AND SHORT WAVE ENERGY PASSING THROUGH THE REGION TODAY AND
TONIGHT. THE TROUGH AXIS DOES GO THROUGH EAST KENTUCKY BY TUESDAY
MORNING...THOUGH...AND THIS WILL BE FOLLOWED BY RISING HEIGHTS IN
THE WAKE OF THE TROUGH. THE MESOSCALE WILL STILL DOMINATE OUR WEATHER
WITH DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES HELPING TO DRIVE THE
CONVECTION AHEAD OF THE COLD FRONT THAT WILL PUSH THROUGH EAST
KENTUCKY LATER TONIGHT. ACCORDINGLY...HAVE LEANED TOWARD THE HIGHER
RESOLUTION NAM12 FOR WEATHER DETAILS...BUT MORE BROAD BRUSHED WITH
THE SPECIFICS...ALONG WITH USING THE HRRR FOR THE NEAR TERM.

SENSIBLE WEATHER WILL FEATURE A RECHARGING OF THE AIR MASS OVER EAST
KENTUCKY TODAY WITH BUILDING INSTABILITY AHEAD OF THAT FRONT. THIS
SHOULD YIELD SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY
MID AFTERNOON. GRADUALLY THE CONVECTION WILL SHRINK SOUTHEAST DURING
THE EVENING HOURS AS THE FRONT PUSHES THE DEEPER MOISTURE OUT OF THE
AREA. AS A RESULT...HAVE MAXED OUT POPS NEAR 00Z FOR THE AREA WITH A
TAPERING FROM NORTHWEST TO SOUTHEAST THEREAFTER. COOLER AIR FILTERING
INTO THE STATE IN THE WAKE OF THE FRONT WILL LEAD TO LOWER TEMPS IN
THE NORTHWEST PARTS OF THE CWA BY TUESDAY MORNING...THOUGH MUGGY
VALUES WILL REMAIN TO THE SOUTH AND EAST. DRIER AIR TAKES OVER ON
TUESDAY BRINGING A NICE CHANGE...MAKING FOR A PLEASANTLY DRY AND
COOLER DAY.

AGAIN USED THE CONSSHORT AND ITS BC VERSION FOR A STARTING POINT WITH
THE DEWPOINT AND WIND GRIDS...RESPECTIVELY...UNTIL 00Z TUESDAY...
FOLLOWED THE CONSALL FOR THE REST. FOR TEMPS...ADJUSTED THE CONSALL
FOR SOME MINOR TERRAIN ENHANCEMENTS IN THE LOWS TONIGHT WITH THE
HOURLY DIURNAL CURVE DERIVED FROM THE NAM12. AS FOR POPS...ENDED UP
CLOSER TO THE WETTER MAV GUIDANCE TODAY...AND SIMILAR TO BOTH
TONIGHT...THEN DRY ON TUESDAY.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 2 2013

NOT A LOT OF CHANGE FOR THE EXTENDED PERIOD. TUESDAY NIGHT/WEDNESDAY
SHOULD BEGIN WITH UPPER LEVEL TROUGHING AND SURFACE HIGH PRESSURE IN
PLACE WITH LIGHT WINDS. THE ONLY MOISTURE AVAILABLE IN THE
ATMOSPHERE WILL BE IN THE UPPER LEVELS WEDNESDAY AFTERNOON...WITH
ABUNDANT DRYING BELOW. AS A RESULT...SOME CIRRUS CLOUDS WILL BE
PRESENT...BUT OTHERWISE WEATHER WILL BE QUITE BENIGN. COOLER AND
DRIER AIR FLOWING IN FROM CANADA WILL KEEP HIGH TEMPS AND HUMIDITY
AT BAY.

FOR THURSDAY...MUCH OF THE SAME IS EXPECTED THROUGH THE FIRST HALF
OF THE DAY. THEN...AS WAS MENTIONED IN PREVIOUS FORECAST...AN
IMPULSE DROPPING INTO A LARGE UPPER TROUGH OVER THE NE CONUS AND SE
CANADA WILL SEND ANOTHER COLD FRONT SOUTH TOWARD THE LOCAL AREA
THURSDAY AFTERNOON OR THURSDAY NIGHT. HOWEVER... VIRTUALLY NO LOW
LEVEL MOISTURE RETURN IS EXPECTED...AND THE FRONT SHOULD BE DYING
OUT AS IT APPROACHES...WITH ALMOST NO IMPACT ON OUR LOCAL
WEATHER. AS THE FRONT DIES...HIGH PRESSURE DROPPING IN BEHIND IT
WILL MERGE WITH HIGH PRESSURE ORIGINALLY TO THE SOUTH OF THE
FRONT...WITH THE LOCAL RESULT BEING DRY WEATHER UNDER ITS DOMINANCE
THROUGH AT LEAST FRIDAY NIGHT.

A WEAK DISTURBANCE WILL TRY TO MOVE THROUGH THE OHIO VALLEY AND ERN
KY LATE IN THE WEEKEND. HOWEVER AT THIS POINT...LATEST GFS SOUNDINGS
ARE STILL LOOKING RATHER LACKLUSTER FOR ANY WIDESPREAD PRECIP
CHANCES. THE GFS IS STILL TRYING TO PINPOINT SOME AFTERNOON
CONVECTION OVER THE HIGHER APPALACHIAN TERRAIN THROUGH THE
WEEKEND...REACHING INTO THE FAR SE COALFIELDS OF KY. THE ECMWF HAS
THE SAME IDEA...BUT CONTINUES TO KEEP ALL PRECIP CHANCES TO OUR SE
OVER THE HIGHER APPALACHIAN TERRAIN. ALL THINGS CONSIDERED...WITH
LITTLE AGREEMENT OR SYNOPTIC SUPPORT...WILL CONTINUE WITH ONLY
SLIGHT CHANCE POPS AT BEST FOR THE FAR SE COUNTIES DURING THE
WEEKEND. ELSEWHERE...THE RETURN OF MORE SRLY FLOW WILL ALLOW
TEMPERATURES TO INCREASE SLIGHTLY THROUGHOUT THE WEEKEND...REACHING
THE MID AND UPPER 80S. HUMIDITY VALUES ON THE OTHER HAND WILL REMAIN
AT BAY...KEEPING CONDITIONS WARM BUT PLEASANT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 230 AM EDT MON SEP 2 2013

THE MAIN CONCERN THROUGH THE REST OF THE NIGHT WILL BE A POTENTIAL
FOR FOG SINCE IT NOW APPEARS THAT ANY NEW CONVECTION WILL HOLD OFF
UNTIL AFTER DAY BREAK. WITH VARIABLE MID AND LOW LEVEL CLOUDS ABOUT
THE FOG MAY BE INTERMITTENT AND REMAIN PRINCIPALLY MVFR...WHERE IT
OCCURS. THE LOWER END OF THE CIGS WILL ALSO BE OCCASIONALLY MVFR.
HAVE ADDED THIS TO THE TAFS WITH A TEMPO DOWN TO IFR VIS DURING THE
PRE-DAWN HOURS INCLUDED AT LOZ. THERE IS STILL TOO MUCH UNCERTAINTY
WITH TIMING AND COVERAGE OF ANY FRESH CONVECTION ON MONDAY TO GO ANY
MORE SPECIFIC THAN JUST A VCTS AT THE TAF SITES THROUGH THE DAY...FOR
NOW. AGAIN...OUTSIDE OF ANY STORMS...WINDS WILL BE LIGHT AND
VARIABLE...THOUGH FAVORING THE WEST DURING THE AFTERNOON AND EVENING.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF





AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 130 AM EDT MON SEP 2 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 401 PM EDT SUN SEP 1 2013

12Z ROABS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW PAIR OF VIGOROUS
SHRTWVS DIGGING THRU ONTARIO/LK SUP IN THE NW FLOW ALF BTWN RDG OVER
THE ROCKIES AND A TROF OVER ERN NAMERICA. WHILE DRYING ALF UNDER
DNVA/UPR CONFLUENCE/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE MOST
IMPRESSIVE SHRTWV MOVING ACRS NRN LK SUP HAS ENDED THE SHRA OVER THE
SW CWA...MORE NMRS SHRA/TS IN THE COMMA TAIL IN ADVANCE OF RATHER
WEAK ATTENDANT COLD FNT...WHERE RUC ANALYSIS SHOWS KINX NOT FAR FM
40/STEEPER MID LVL LAPSE RATES/MUCAPE IN THE 500-1000J/KG RANGE...
ARE  MOVING THRU THE ERN ZNS. MORE NMRS SHRA/TS ALSO IMPACTED THE
KEWEENAW EARLIER IN THE DAY CLOSER TO THE COMMA HEAD ASSOCIATED WITH
THIS SHRTWV. THE MAIN HAZARD FM ALL THE SHRA/TS HAVE BEEN HEAVY
DOWNPOURS...WHICH PROMPTED THE ISSUANCE OF AN URBAN/SMALL STREAM
FLOOD ADVY FOR THE KEWEENAW EARLIER IN THE AFTN FOLLOWING A REPORT
OF 2 INCHES OF RA IN AN HOUR NEAR CALUMET. EVEN THOUGH THERE HAS
BEEN DRYING ALF OVER THE W IN THE WAKE OF THE WEAK SFC COLD
FROPA...A FEW -SHRA HAVE DVLPD IN THIS AREA ALONG WITH SOME LO CLDS
AS LLVL MSTR SHOWN ON THE 12Z INL RAOB HAS OVERSPREAD THE AREA IN
THE NW LLVL FLOW IN THE WAKE OF THE SHRTWV. LARGE SCALE QVECTOR
DVGC/SUBSIDENCE IN THE WAKE OF THE DEPARTING SHRTWV HAVE TENDED TO
LIMIT THE INTENSITY OF THESE -SHRA. THERE IS A SHARPER SURGE OF COOL
AIR ASSOCIATED WITH THE SECOND SHRTWV DROPPING SSEWD IN NW ONTARIO.
LO CLDS ARE WIDESRPEAD TO THE NW OF LK SUP WITH SOME -RA/-DZ
REPORTED IN THE CYC FLOW ON THE NW FLANK OF SFC LO PRES MOVING THRU
LK SUP THAT ASSOCIATED WITH THE FIRST SHRTWV.

REST OF THIS AFTN/TNGT...EXPECT LINGERING SHRA/TS OVER THE ERN ZNS
LATE THIS AFTN TO SHIFT TO THE E FOLLOWING DEPARTURE OF AXIS OF HIER
RH/DEEP LYR QVECTOR CNVGC AND UNDER DEEP LYR QVECTOR DVGC BEHIND
DEPARTING FIRST SHRTWV. FOLLOWING THE PASSAGE OF REINFORCING COLD
FNT EARLY THIS EVNG ASSOCIATED WITH THE SECOND SHRTWV DIGGING THRU
ONTARIO...EXPECT WIDESPREAD LO CLD/SOME -DZ TO DVLP ESPECIALLY IN
THE UPSLOPE AREAS NEAR LK SUP AS LLVL NNW FLOW DRIVES NEAR SFC COOL
AIR INTO THE AREA AND SHARPENS INVRN BASE NEAR H9 AS SHOWN ON 12Z
LOCAL WRF ARW FCST SDNGS. THE COMBINATION OF GUSTY WINDS WITH H925
WINDS FCST UP TO 25-30 KTS AND THE ARRIVAL OF THE COOLER AIR WL MAKE
THE NGT FEEL QUITE CHILLY AS COMPARED TO THE WARM WX IN RECENT WEEKS.

LABOR DAY...MON WL FEATURE A CONFLUENT NW FLOW OVER THE UPR LKS/DEEP
LYR QVECTOR DVGC. MAIN FCST CONCERN IS HOW QUICKLY LO CLDS/-DZ WITH
SHALLOW MOIST LYR BLO SHARP LLVL INVRN WL DEPART. GIVEN THE
INTENSITY OF THE DISTURBANCES IN PLAY TODAY...PREFERRED TO FOLLOW
THE 12Z LOCAL WRF-ARW FCST SCENARIO...WHICH SHOWS MORE PERSISTENT
LLVL MSTR MAINTAINED BY STRONGER N WIND. BUT EVEN THIS MODEL
INDICATES SOME IMPROVEMENT IN THE AFTN ESPECIALLY OVER THE W HALF
WITH CLOSER APRCH OF SFC HI PRES/WEAKER AND MORE ACYC FLOW. EXPECT
THE RETURN OF AT LEAST SOME SUNSHINE IN THAT AREA AFT 18Z. TEMPS WL
RUN BLO NORMAL FOR THE FIRST TIME IN QUITE AWHILE.

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 401 PM EDT SUN SEP 1 2013

QUITE A TRANQUIL PERIOD OF WEATHER EXPECTED OVER THE NEXT WEEK AS
LARGE SCALE FEATURES TREND BACK TO THE EARLY SUMMER SET-UP OF A
WESTERN RIDGE AND EASTERN TROUGH. TEMPERATURES SHOULD BE AT TO
SLIGHTLY ABOVE NORMAL THROUGH THE WEEK.

MONDAY NIGHT THROUGH TUESDAY NIGHT...A STRONG MID-LEVEL SHORTWAVE
TROUGH AND AN ACCOMPANYING SFC LOW WILL BE OVER THE SOUTHEAST
ONTARIO AND QUEBEC BORDER AT THE START OF THE PERIOD...AND WILL BE
CONTINUING TO MOVE EAST MONDAY NIGHT. MEANWHILE...MID-LEVEL RIDGING
WILL BE BUILDING INTO THE UPPER MS VALLEY AS A SFC HIGH PRESSURE
SETTLES OVER OVER NW TO CENTRAL WI. MAIN QUESTIONS IN THIS TIME
FRAME REVOLVE AROUND DEPARTING LOW CLOUD COVER IN THE EAST...AND MIN
TEMPS FOR THE WEST.

INCREASINGLY DRIER AIR WILL CONTINUE ADVECTING INTO THE REGION FROM
THE NW AHEAD OF THE SFC HIGH. ATTM...IT APPEARS THAT LOW-CLOUDS
UNDER AN H8 INVERSION SHOULD DISSIPATE ENOUGH FROM INSOLATION AND
INCOMING DRY AIR TO RESULT IN MOSTLY CLEAR SKIES FOR THE WEST HALF.
THE EAST HALF IS A BIT MORE TRICKY...WITH THE NAM NON-SURPRISINGLY
KEEPING LOW STRATUS ACROSS THE AREA WELL INTO THE OVERNIGHT HOURS.
OVERALL...FEELING IS THAT CLOUDS WILL CLEAR OUT BY MIDNIGHT FOR THE
EAST.

WITH THE GRADIENT FLOW WEAKENING ACROSS THE WEST...AND PWAT VALUES
AROUND 0.5 INCHES...GOOD RADIATIONAL COOLING IS EXPECTED. HAVE
FORECAST TEMPS IN THE LOW 40S INTERIOR WEST...WITH EVEN A COUPLE
POCKETS OF UPPER 30S. LOWS SHOULD REMAIN AROUND 50 ALONG THE GREAT
LAKES...AND ACROSS THE EAST HALF WHERE GRADIENT FLOW REMAINS
STRONGER THROUGHOUT THE NIGHT.

BROAD RIDGING MOVES ACROSS THE UPPER GREAT LAKES ON TUESDAY...AND
WILL BRING SUNNY SKIES WITH TEMPS WARMING TO THE MID 70S. RETURN
FLOW ON THE BACKSIDE OF THE SFC HIGH ALONG WITH INCREASING MID-LEVEL
CLOUDS SHOULD KEEP TEMPS FROM FALLING OFF TOO MUCH TUESDAY...WITH
COLDEST LOWS ONLY IN THE UPPER 40S. PLENTY OF DRY AIR ABOVE THE
INVERSION SHOULD ALLOW RH VALUES TO FALL INTO THE MID 30S TO AROUND
40 FOR INTERIOR LOCATIONS...THOUGH WINDS WILL BE QUITE LIGHT.

WEDNESDAY...A STRENGTHENING SHORTWAVE ACROSS NORTHERN CANADA WILL
QUICKLY TRACK SOUTHEAST ACROSS NORTHERN MANITOBA ON TUESDAY...AND
SOUTHERN HUDSON BAY TUESDAY NIGHT INTO WEDNESDAY MORNING. AN
ASSOCIATED STRENGTHENING SFC LOW WILL SEND A COLD FRONT FROM NORTH
TO SOUTH ACROSS THE CWA LATE TUESDAY NIGHT INTO WEDNESDAY. NEARLY
ALL FORCING BY WAY OF MID-LEVEL Q-VECTOR CONVERGENCE WILL STAY WELL
NORTH AND EAST OF THE AREA. GIVEN LIMITED MOISTURE WITH THIS
SYSTEM...DO NOT EXPECT ANYTHING MORE THAN SOME SCATTERED TO BROKEN
MID-LEVEL CLOUDINESS. ONE EXCEPTION COULD BE A BRIEF BOUT OF
POST-FRONTAL UPSLOPE DRIZZLE ACROSS THE NORTH-CENTRAL CWA...BUT WITH
DRY AIR MOVING IN QUICKLY BEHIND THE FRONT...LEFT OUT OF THE FCST
FOR NOW.

THE ECMWF HAS BEEN ON THE FASTER END OF GUIDANCE WITH THE PASSAGE OF
THE FRONT...CLEARING MUCH OF THE CWA BY NOON. THE GFS HAD BEEN
SEVERAL HOURS SLOWER...NOT CLEARING THE CWA UNTIL MID TO LATE
AFTERNOON. HOWEVER...IT HAS TRENDED 3 TO 5 HOURS QUICKER OVER THE
LAST SEVERAL RUNS...AND NOW LINES UP MUCH BETTER WITH THE ECMWF.
WILL FOLLOW THE IDEA OF A QUICKER FRONTAL PASSAGE. STRENGTHENING
HIGH PRESSURE TRACKING SOUTHEASTWARD INTO THE UPPER MS VALLEY BEHIND
THE FRONT WILL INDUCE A MODEST ISALLOBARIC WIND COMPONENT AND BRING
A WINDOW OF BREEZY CONDITIONS WEDNESDAY MORNING...PRODUCING AN
ELEVATED SWIM RISK FOR WEDNESDAY.

WEDNESDAY NIGHT THROUGH SUNDAY...HIGH PRESSURE WILL SETTLE OVER THE
AREA WEDNESDAY NIGHT AND ALLOW TEMPS TO ONCE AGAIN FALL WELL INTO
THE 40S FOR INTERIOR LOCATIONS. DEEP TROUGHING IN THE WEST WILL
DEVELOP BY LATE IN THE WEEK AND DOMINATE THE PATTERN ACROSS THE NE
CONUS. A COUPLE OF WEAK SHORTWAVES WILL TRACK ALONG THE BACKSIDE OF
THIS TROUGH AND AFFECT THE CWA. TIMING AND STRENGTH ARE TYPICALLY
DIFFICULT TO PIN DOWN IN THIS TYPE OF FLOW REGIME...SO WILL USE
CONSENSUS FORECAST THROUGH THE WEEKEND. WITH THAT SAID...BEST CHANCE
TO SEE SOME ISOLATED SHOWERS AND A FEW THUNDERSTORMS WILL BE FRIDAY
AND FRIDAY NIGHT AS A COLD FRONT DROPS SOUTH THROUGH THE REGION.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 129 AM EDT MON SEP 2 2013

WITH LOW-LEVEL MOISTURE AND CYCLONIC UPSLOPE NNW FLOW OVERNIGHT...
IFR/LOW MVFR CONDITIONS WILL BE THE RULE AT KIWD/KCMX/KSAW. OCNL -DZ
AND -SHRA/SPRINKLES ARE LIKELY AS WELL. AS HIGH PRES BUILDS IN FROM
THE W AND DRIER AIR ADVECTS INTO THE AREA FROM THE N (NOTE CLEARING
OVER NRN ONTARIO ON SATELLITE IMAGERY)...EXPECT GRADUALLY IMPROVING
CONDITIONS FROM W TO E TODAY. IN FACT...CLOUDS SHOULD SCATTER OUT OR
CLEAR COMPLETELY IN THE MID AFTN AT KCMX/KIWD. IT MAY NOT BE UNTIL
LATE AFTN/EARLY EVENING THAT CLOUDS SCATTER OUT AT KSAW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 401 PM EDT SUN SEP 1 2013

FOLLOWING A COLD FRONTAL PASSAGE LATE THIS AFTERNOON/EARLY
EVENING...EXPECT NNW WINDS UP TO 30 KTS TO DEVELOP OVER THE LAKE AND
CONTINUE INTO MON...WHEN A HI PRES APPROACHING THE UPPER LAKES WILL
CAUSE THE WINDS TO DIMINISH WEST-TO-EAST THRU MON NIGHT. LOOK FOR
LIGHTER WINDS ON TUE AS THE HI PRES MOVES OVER THE UPPER LAKES.
STRONGER NNW WINDS UP TO 25 KTS WILL DEVELOP OVER THE E HALF ON WED
FOLLOWING ANOTHER COLD FRONTAL PASSAGE. THEN WINDS SHOULD DIMINISH
QUICKLY THE REST OF THE WEEK AS ANOTHER HI PRES/WEAK PRES GRADIENT
MOVE OVER THE LAKE.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ005-006.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...KC







AREA FORECAST DISCUSSION

NWS ELKO NV

 1018 PM PDT SUN SEP 1 2013

.SYNOPSIS...MONSOON MOISTURE WILL INCREASE ACROSS NEVADA TONIGHT
THROUGH MONDAY...WITH SHOWERS AND THUNDERSTORMS BECOMING
INCREASINGLY LIKELY. SOME STORMS WILL PRODUCE HEAVY RAIN AND
LOCALIZED FLOODING. MONSOON MOISTURE IS EXPECTED TO LINGER FOR
MUCH OF THIS WEEK.

&&

.UPDATE...VORT MAX ASSOCIATED WITH THIS MONSOON PUSH HAS PROVEN
EXTREMELY EFFICIENT...WITH MULTIPLE REPORTS OF FLASH FLOODING
ACROSS THE WATCH AREA AND THUNDERSTORMS CONTINUING TO DEVELOP AT
THIS LATE HOUR. DECIDED TO EXTEND FLASH FLOOD WATCH AN ADDITIONAL
6 HOURS GIVEN CURRENT TRENDS AND LATEST GUIDANCE. FURTHER
ADJUSTMENTS MAY BE FORTHCOMING WITH EARLY MORNING PACKAGE...BUT NO
ADDITIONAL CHANGES WERE MADE AT THIS TIME. RCM

&&

.PREV DISCUSSION... /ISSUED AT 200 PM /

SYNOPSIS...MONSOON MOISTURE WILL INCREASE ACROSS NEVADA TONIGHT
THROUGH MONDAY...WITH SHOWERS AND THUNDERSTORMS BECOMING
INCREASINGLY LIKELY. SOME STORMS WILL PRODUCE HEAVY RAIN AND
LOCALIZED FLOODING. MONSOON MOISTURE IS EXPECTED TO LINGER FOR
MUCH OF THIS WEEK.

SHORT TERM...TONIGHT THROUGH TUESDAY.

AN IMPRESSIVE SURGE OF MONSOON MOISTURE IS ORGANIZING ACROSS
CENTRAL AND SOUTHERN NEVADA THIS AFTERNOON, WHERE YET ANOTHER CROP
OF SCATTERED THUNDERSTORMS IS GETTING UNDERWAY. 12Z NAM AND THE
3KM-HRRR BOTH SPREAD NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE
SOUTHERN HALF OF THE CWA /WHITE PINE, NYE, SOUTHERN LANDER/EUREKA
COUNTIES/ THROUGH THIS EVENING. VISIBLE SATELLITE REVEALS
PERCOLATING CUMULUS ON THE HIGHER TERRAIN OF CENTRAL NEVADA, WITH
SPC MESOANALYSIS REVEALING LIFTED INDEX TO -5 AND CAPE TO
1500 J/KG, AND THAT`S ONLY AS OF NOON. EXTRA MOISTURE IN THE AIR
SEEMS TO BE SLOWING HEATING SOMEWHAT, AND SOME WARMER AIR ALOFT IS
NOT HELPING EITHER. BUT THUNDERSTORMS ARE EXPECTED THROUGH THIS
EVENING NONETHELESS. WILL MAINTAIN FLASH FLOOD WATCH FOR CENTRAL
NEVADA THROUGH 11 PM, WHERE THE GREATEST CONCENTRATION OF STORMS
WILL BE LOCATED. 3KM HRRR FORECASTS A COMPLEX OF THUNDERSTORMS
ENTERING SOUTHERN ELKO COUNTY WITH THE MAIN MOISTURE SURGE AROUND
MIDNIGHT TONIGHT. KEPT SHOWER AND THUNDERSTORM COVERAGE MUCH
HIGHER TONIGHT THAN IS TYPICAL, WITH LOCALLY HEAVY RAIN LIKELY.
WILL LET THE FLASH FLOOD WATCH EXPIRE AT 11 PM FOR NOW, BUT
CONFIDENT THE CONVECTION WILL NOT END THEN, SO THE EVENING SHIFT
WILL NEED TO DETERMINE WHETHER TO EXTEND THE WATCH THROUGH
TONIGHT. MOISTURE QUALITY WILL BE INCREASING DRAMATICALLY TONIGHT
THROUGH MONDAY MORNING, AND WITH GFS/NAM BOTH FORECASTING
SIGNIFICANT INSTABILITY OVERNIGHT INTO MONDAY MORNING, NOCTURNAL
CONVECTION IS LIKELY. FURTHER AIDING THE THUNDERSTORMS WILL BE THE
ADVERTISED WEAK SHORTWAVE, ROTATING NORTH THROUGH EASTERN NEVADA
IN THE MOIST MONSOON FLOW, AND APPROACHING ELKO COUNTY AROUND 5 AM
MONDAY. THIS IS THE MOST STABLE TIME OF DAY /THE CONVECTIVE
MINIMUM/ BUT DESPITE THIS, EXPECT SOME THUNDERSTORMS WILL SURVIVE
THE NIGHT.

WITH THE CLOUDS, RAIN, AND RAPIDLY INCREASING HUMIDITY LOW
TEMPERATURES LABOR DAY MORNING WILL BE VERY MILD AND WAY ABOVE
NORMAL, IN THE UPPER 50S AND LOWER 60S. SOME RECORD WARM OVERNIGHT
LOWS ARE LIKELY, ELKO`S RECORD FOR SEP 2ND IS 59 SET IN 1960. MY
FORECASTED LOW IS 61 DEGREES.

LABOR DAY...CLOUDY AND MOIST WITH SHOWERS AND THUNDERSTORMS
LIKELY. MOISTURE WILL BE PLENTIFUL WITH PRECIPITABLE WATER VALUES
NEAR RECORD LEVELS FOR EARLY SEPTEMBER, RANGING FROM 1-1.2 INCHES.
ANY STORMS THAT DEVELOP MONDAY WILL PRODUCE EXCESSIVE RAINFALL.
THE QUESTION IS, WILL THERE BE ENOUGH INSTABILITY FOR
THUNDERSTORMS TO REDEVELOP MONDAY? THE ANSWER FROM MANY MODELS,
THE 12/18Z NAM, 12Z GFS AND ECMWF IS A UNANIMOUS YES. ALL GUIDANCE
ALLOWS SCATTERED TO NUMEROUS THUNDERSTORMS TO REDEVELOP ACROSS
NEVADA MONDAY AFTERNOON AND EVENING, EVEN ALL THE WAY INTO
HUMBOLDT COUNTY. SOME FORECASTER CONCERNS REGARDING THIS SCENARIO:
1) THE SHORTWAVE THAT WILL HELP TRIGGER STORMS TONIGHT IS COMING
THROUGH NE NEVADA LATE TONIGHT AND EARLY MONDAY, NOT A GREAT TIME
TO GET STORMS GOING. IN FACT, SUBSIDENCE BEHIND THE DEPARTING WAVE
AND THE SINKING AIR ASSOCIATED WITH IT MAY HINDER THUNDERSTORM
GROWTH MONDAY AFTERNOON, AND 2) WE ARE GOING TO BE VERY MOIST.
SKIES WILL BE MOSTLY CLOUDY TO CLOUDY ALL DAY, AND IT MAY PROVE
DIFFICULT TO GET THE SUNSHINE NEEDED FOR NEW STORM INITIATION.
DESPITE THESE CONCERNS, FORECASTED SCATTERED TO NUMEROUS
THUNDERSTORMS FOR ALL ZONES MONDAY. BECAUSE OF THE UNCERTAINTIES,
WILL NOT ISSUE ANOTHER FLASH FLOOD WATCH FOR MONDAY, BUT THIS WILL
REQUIRE CAREFUL WATCHING, ESPECIALLY GIVEN THE OUTDOOR HOLIDAY
ACTIVITIES. FOR NOW, SORT OF TOOK A MIDDLE GROUND AND MENTIONED
HEAVY RAIN IN THE GRIDS FOR NE NEVADA. AGAIN, WITH NEAR RECORD PW
IN THE ATMOSPHERE, ANY STORM WILL PRODUCE VERY HEAVY RAIN.

NOT THE BEST FORECAST FOR LABOR DAY PLANS, BUT DOUBT MANY WILL
COMPLAIN AS THE NEVADA DROUGHT CONTINUES.

TUESDAY...CONTINUED MOIST AND UNSTABLE. PW REMAINS VERY HEALTHY,
RANGING FROM 0.80-1.2 INCH. 12Z GFS FORECASTS WIDESPREAD NEGATIVE
LIFTED INDICES AT 5 PM TUESDAY, SO INCREASED THUNDERSTORM COVERAGE IN
THE GRIDS ACCORDINGLY. TURNER

LONG TERM...TUESDAY NIGHT THROUGH NEXT SUNDAY. MODELS AGREE FAIRLY
WELL WITH THE OVERALL PATTERN THROUGH THE PERIOD. THE CWA IS UNDER
THE INFLUENCE OF THE "MONSOON" MOISTURE TUESDAY NIGHT THROUGH
THURSDAY...HOWEVER UPPER TROF PUSHES INLAND SHOVING THE TSTM
ACTIVITY TO EASTERN NV ON THURSDAY. BY FRIDAY TROF WEAKENS OVER
THE CWA AS IT MOVES NORTH INTO THE PACIFIC NORTHWEST. AGAIN THE
TSTM ACTIVITY IS EXPECTED TO BE CONFINED TO EASTERN NV. BY
SATURDAY INSTABILITY IS PUSHED INTO WHITE PINE COUNTY AS TROF
MOVES TO THE NORTH OF NEVADA. THEN EXPECT DRY CONDITIONS NEXT
SUNDAY AS FOUR CORNER HIGH GETS SUPPRESSED. JH

AVIATION...VFR ALL TERMINALS. KWMC AND KEKO WILL SEE PERIODIC SMOKY
CONDITIONS...BUT IS NOT EXPECTED TO REDUCE SURFACE VSBY. KEKO WILL
ALSO HAVE VCTS THIS EVENING AND MONDAY AFTERNOON. KTPH AND KELY MAY
HAVE -TSRA THROUGH EARLY EVENING. KELY MAY SEE HEAVY RAIN AT
TIMES. JH

FIRE WEATHER...SCATTERED TO NUMEROUS THUNDERSTORMS THIS AFTERNOON
THROUGH MONDAY. WHILE LIGHTNING WILL BE PLENTIFUL, WETTING RAINS
AND MUCH HIGHER RH WILL MINIMIZE THE RISK FOR NEW LIGHTNING
IGNITIONS. RETURNING MONSOON MOISTURE WILL ALLOW FOR MUCH HIGHER
MAX/MIN RH AND GREAT OVERNIGHT RECOVERIES. TURNER

&&

.LKN WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 5 AM PDT MONDAY FOR NORTHEASTERN NYE
COUNTY...NORTHWESTERN NYE COUNTY...SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.

&&

$$

93





AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 141 AM EDT MON SEP 2 2013

.SYNOPSIS...
MUGGY ENVIRONMENT LINGERS INTO MONDAY EVENING. COLD FRONT MONDAY
NIGHT. COOLER AND DRIER AIRMASS TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE...DRIED OUT POPS FOR MUCH OF THE MORNING.
OTHERWISE...MADE NO MAJOR CHANGES TO THE FORECAST.

PREVIOUS DISCUSSION FOLLOWS...
AFTERNOON DISTURBANCE EXITING SOUTHERN MOUNTAINS AND GREENBRIER
VALLEY NOW.  WAS FASTER LOWERING POPS DOWN THIS EVENING.  ALSO
FASTER FORMING SOME VALLEY FOG IN THE SOUTHERN COAL FIELDS AND
GREENBRIER VALLEY IN WAKE OF THE LATE AFTERNOON SHOWERS.

DESPITE THE LACK OF CONVECTION AND CLOUDS OVER OUR WESTERN
LOWLANDS...STILL THINK A LATE NIGHT OR MORNING SHOWER OR
THUNDERSTORM COULD REFORM OVERNIGHT.  SO ONLY REMOVAL OF POPS WAS
EARLY THIS EVENING BEFORE INCREASING BACK INTO THE 20 TO 30 PERCENT
RANGE FOR ANY ONE SPOT. RAP INDICATES A WEAK MID LEVEL DISTURBANCE
PASSING SE OHIO AROUND 03Z TO 05Z AND IN WV AFTER 05Z.

THIS PLAYS HAVOC WITH FIGURING OUT THE FOG COVERAGE FOR THE PREDAWN.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
COLD FRONT FINALLY DEPARTS MONDAY NIGHT WITH HIGH PRESSURE BUILDING
IN BEHIND THE SYSTEM. VERY DRY AIR TO ADVECT IN BEHIND THE FRONT FOR
TUESDAY...ALTHOUGH MAY START OUT WITH SOME LOW LEVEL STRATUS IN
PLACE AS NAM BUFR SOUNDINGS SUGGEST SATURATION BELOW 875MB AND
NORTHERLY FLOW AT 925MB. LOW STRATUS DECK SHOULD LIFT AND DISSOLVE
BY LATE MORNING TUESDAY AND BE REPLACED IN THE AFTERNOON BY DIURNAL
CUMULUS AS A RESULT OF BOUNDARY LAYER MIXING. WILL BE COMPLETELY
DEVOID OF ANY MOISTURE ALL THE WAY THROUGH WEDNESDAY...LESS SOME
PATCHY THIN CIRRUS DRIFTING THROUGH ON WEDNESDAY AFTERNOON.

WITH A NEW AIRMASS IN PLACE...CAN EXPECT MORE TYPICAL LATE SUMMER
CONDITIONS IN TERMS OF TEMPERATURES AND DEWPOINTS AT THE SURFACE.
DRIER AIR AND INSOLATION WILL ALLOW TEMPERATURES TO DROP INTO THE
50S TUESDAY NIGHT...WITH SOME ISOLATED 40S IN THE LOWLANDS...AND
MORE PREVALENT IN THE MOUNTAINS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
EXTENDED FORECAST REMAINS PRIMARILY DRY. HIGH PRESSURE IN CONTROL
INTO THE EARLY PART OF THE WEEKEND...BUT MAY GET THE TAIL END OF A
COLD FRONT FOR THE END OF THE WEEK. THIS WOULD HAVE LITTLE AFFECT ON
THE MIDDLE OHIO VALLEY AND CENTRAL APPALACHIANS OTHER THAN A LITTLE
CLOUD COVER. LONG RANGE MODELS DEVELOP A SURFACE LOW IN THE CENTRAL
PLAINS FOR THE END OF THE WEEKEND WITH A WARM FRONT TO OUR NORTH. IN
THE END...HEIGHTS MAKE A RECOVERY FROM THE MILDER AIRMASS AT THE
BEGINNING OF THE LONG TERM FORECAST...AND WILL PUSH TO SLIGHTLY
ABOVE NORMAL TEMPERATURES AGAIN BY DAY 7.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
MVFR/IFR VALLEY FOG EXPECTED THROUGH 13Z...BEFORE LIFTING TO VFR
AREA WIDE. COLD FRONT WILL APPROACH DURING THE DAY MONDAY...AND
MOVE EAST ACROSS THE AREA MONDAY NIGHT. EXPECT SCATTERED SHOWERS
AND THUNDERSTORMS TO DEVELOP...MAINLY AFTER 14Z...WITH BRIEF
MVFR/IFR CONDITIONS AND GUSTY WINDS IN VICINITY OF STORMS.

AFTER 04Z...BULK OF CONVECTION SHOULD HAVE DIED
DOWN...PARTICULARLY ACROSS SOUTHEAST OHIO...EASTERN KENTUCKY...AND
ADJACENT WV AREAS. BEHIND THE FRONT...PARTIAL CLEARING ACROSS THE
NORTH/WEST...WILL RESULT IN THE FORMATION OF IFR/LIFR FOG...WITH
FOG OR LOW STRATUS GENERALLY ALONG/EAST OF A LINE FROM CRW TO CKB.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z
TUESDAY...

FORECAST CONFIDENCE: MEDIUM.

ALTERNATE SCENARIOS: FOG DEVELOPMENT AND DENSITY 06Z TO 12Z MONDAY
TOUGH TO FIGURE DUE TO CLOUD COVER AND CHANCE OF CONVECTION
REFORMING. DEVELOPMENT OF FOG AND OR STRATUS AFTER 00Z TUESDAY MAY
VARY FROM FORECAST.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

DATE                              MON 09/02/13
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  L    L    L    L    L    L    H    H    H    H    H    M
HTS CONSISTENCY  H    M    M    M    L    L    H    H    H    H    H    M
BKW CONSISTENCY  L    L    L    L    L    H    H    H    M    M    M    M
EKN CONSISTENCY  L    L    L    L    L    L    L    L    H    M    M    M
PKB CONSISTENCY  H    H    H    H    L    L    M    H    H    H    H    M
CKB CONSISTENCY  H    M    M    H    L    L    H    H    H    H    H    H

AFTER 06Z TUESDAY...
LINGERING CONVECTION NEAR COLD FRONT MONDAY EVENING MAY CAUSE IFR
CONDITIONS.  IFR FOG POSSIBLE TUESDAY AND WEDNESDAY MORNINGS.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...JMV/26
NEAR TERM...KTB/SL
SHORT TERM...26
LONG TERM...26
AVIATION...SL









AREA FORECAST DISCUSSION...UPDATED

NWS NASHVILLE TN

 1154 PM CDT SUN SEP 1 2013

.UPDATE...
UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT OVERALL EXPECTED
DECREASE IN AREAL COVERAGE OF SHWRS/TSTMS ACROSS THE MID STATE AFTER
MIDNIGHT WITH SOME LOCATIONS EXPERIENCING PATCHY FOG LATE TONIGHT.
&&

.PREV DISCUSSION.../ISSUED 1148 PM CDT SUN SEP 1 2013/

UPDATE...FOR AVIATION.

AVIATION...
06Z TAFS...A BATCH OF SHOWERS WAS MOVING TOWARD BNA AND MAY
BRIEFLY DIP VSBYS TO MVFR BEFORE 08Z. OTHERWISE SHOULD BE A QUITE
NIGHT WITH AREAS OF MAINLY MVFR FOG. FOR MONDAY...AN APPROACHING
FRONT WILL BRING SCT TSRA AFTER 02/18Z. OUTSIDE STORMS...VFR
CONDITIONS WILL PREVAIL. BY THE END OF THE TAF PERIOD...FROPA
WILL SHIFT WINDS TO NNW WITH DRIER AND MORE STABLE AIR ARRIVING.

13

PREV DISCUSSION... /ISSUED 933 PM CDT SUN SEP 1 2013/

UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT ISO TO SCT
SHWRS/TSTMS COMING INTO WRN PORTIONS OF THE MID STATE THIS EVENING.
HAVE UPDATED SKY CONDITIONS TO MOCLDY AND WITH CURRENT TEMP TRENDS...
HAVE LOWERED LOWS BY A DEGREE OR SO. STILL TRICKY FORECAST THRU
TONIGHT AS ATM LOW LEVELS REMAIN RATHER HIGH IN ATM MOISTURE
CONTENT WITH CONTINUED UNSTABLE CONDITIONS...SUBTLE SHORTWAVES IN
UPPER LEVEL PREDOMINATE NWLY FLOW ALOFT INTERACTING...AND SFC
FRONT APPROACHING FROM THE NW BY THE MORNING HRS. HAVE INITIALLY
LEANED TOWARD THE LATEST HRRR MODEL RUNS IN SHOWING SOME ADDITIONAL
DEVELOPMENT FROM THE SW...SPREADING ACROSS THE MID STATE AFTER MIDNIGHT
TONIGHT AS THIS AREA PRESENTLY LOOKS TO HAVE THE BEST OVERALL INSTABILITY
AND MOISTURE POTENTIAL TO SUPPORT SHWR/TSTM DEVELOPMENT.

PREV DISCUSSION... /ISSUED 504 PM CDT SUN SEP 1 2013/

UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT AND
EXPECTED EVENING CONDITIONS FOR TONIGHT WITH ONLY A SLIGHT CHANCE
TO CHANCE OF SHWRS/TSTMS ACROSS SW PORTIONS...OTHERWISE PTCLDY SKIES
EXPECTED ACROSS MID STATE. WITH SFC FRONT AND UPPER LEVEL TROUGH AXIS
APPROACHING OVERNIGHT...WENT WITH INCREASING CHANCES OF SHWRS/TSTMS
AFTER MIDNIGHT ACROSS MID STATE.

31

PREV DISCUSSION.../ISSUED 135 PM CDT SUN SEP 1 2013/

DISCUSSION...CLOUDS AND SCATTERED SHOWERS CONTINUE TO AFFECT
PARTS OF MIDDLE TENNESSEE, WITH MOST TEMPERATURES RUNNING WELL
BELOW FORECAST HIGHS. STILL EXPECT SOME SUNSHINE LATER IN THE
AFTERNOON THAT WILL CLOSE THE GAP SOMEWHAT, BUT CLOUDS HAVE REALLY
THROWN A WRENCH INTO TODAY`S FORECAST. AT ANY RATE, THE MAIN
TROUGH AXIS WILL INCH CLOSER TO MIDDLE TENNESSEE OVERNIGHT, WITH
SCATTERED SHOWERS AND STORMS OCCURRING MAINLY DURING THE 06Z-12Z
PERIOD. LOOK FOR SCATTERED ACTIVITY TO CONTINUE TOMORROW AS THE
SURFACE FRONT ENTERS THE MID STATE DURING THE AFTERNOON.
PRECIPITATION WILL END FROM NW TO SE TOMORROW NIGHT AS WE GET A
BIG AIR MASS CHANCE, WITH SIGNIFICANTLY DRIER, COOLER AIR EVIDENT
BY TUESDAY. EXPECT DRY WEATHER FROM TUESDAY AT LEAST THROUGH
SUNDAY, WITH TEMPERATURES GRADUALLY WARMING THROUGHOUT THE WEEK AS
HIGH PRESSURE DOMINATES OUR WEATHER FOR A PROLONGED STRETCH. AT
THIS TIME, THE SPC CONTINUES TO FORECAST ONLY GENERAL
THUNDERSTORMS FOR MIDDLE TENNESSEE THROUGH TOMORROW NIGHT.

ROSE

&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
31






AREA FORECAST DISCUSSION

NWS NASHVILLE TN

 1148 PM CDT SUN SEP 1 2013

.UPDATE...FOR AVIATION.

&&

.AVIATION...
06Z TAFS...A BATCH OF SHOWERS WAS MOVING TOWARD BNA AND MAY
BRIEFLY DIP VSBYS TO MVFR BEFORE 08Z. OTHERWISE SHOULD BE A QUITE
NIGHT WITH AREAS OF MAINLY MVFR FOG. FOR MONDAY...AN APPROACHING
FRONT WILL BRING SCT TSRA AFTER 02/18Z. OUTSIDE STORMS...VFR
CONDITIONS WILL PREVAIL. BY THE END OF THE TAF PERIOD...FROPA
WILL SHIFT WINDS TO NNW WITH DRIER AND MORE STABLE AIR ARRIVING.

13

&&

.PREV DISCUSSION... /ISSUED 933 PM CDT SUN SEP 1 2013/

UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT ISO TO SCT
SHWRS/TSTMS COMING INTO WRN PORTIONS OF THE MID STATE THIS EVENING.
HAVE UPDATED SKY CONDITIONS TO MOCLDY AND WITH CURRENT TEMP TRENDS...
HAVE LOWERED LOWS BY A DEGREE OR SO. STILL TRICKY FORECAST THRU
TONIGHT AS ATM LOW LEVELS REMAIN RATHER HIGH IN ATM MOISTURE
CONTENT WITH CONTINUED UNSTABLE CONDITIONS...SUBTLE SHORTWAVES IN
UPPER LEVEL PREDOMINATE NWLY FLOW ALOFT INTERACTING...AND SFC
FRONT APPROACHING FROM THE NW BY THE MORNING HRS. HAVE INITIALLY
LEANED TOWARD THE LATEST HRRR MODEL RUNS IN SHOWING SOME ADDITIONAL
DEVELOPMENT FROM THE SW...SPREADING ACROSS THE MID STATE AFTER MIDNIGHT
TONIGHT AS THIS AREA PRESENTLY LOOKS TO HAVE THE BEST OVERALL INSTABILITY
AND MOISTURE POTENTIAL TO SUPPORT SHWR/TSTM DEVELOPMENT.


PREV DISCUSSION... /ISSUED 504 PM CDT SUN SEP 1 2013/

UPDATE...
HAVE UPDATED THE SUITE OF FORECAST PRODUCTS TO REFLECT CURRENT AND
EXPECTED EVENING CONDITIONS FOR TONIGHT WITH ONLY A SLIGHT CHANCE
TO CHANCE OF SHWRS/TSTMS ACROSS SW PORTIONS...OTHERWISE PTCLDY SKIES
EXPECTED ACROSS MID STATE. WITH SFC FRONT AND UPPER LEVEL TROUGH AXIS
APPROACHING OVERNIGHT...WENT WITH INCREASING CHANCES OF SHWRS/TSTMS
AFTER MIDNIGHT ACROSS MID STATE.

31

PREV DISCUSSION.../ISSUED 135 PM CDT SUN SEP 1 2013/

DISCUSSION...CLOUDS AND SCATTERED SHOWERS CONTINUE TO AFFECT
PARTS OF MIDDLE TENNESSEE, WITH MOST TEMPERATURES RUNNING WELL
BELOW FORECAST HIGHS. STILL EXPECT SOME SUNSHINE LATER IN THE
AFTERNOON THAT WILL CLOSE THE GAP SOMEWHAT, BUT CLOUDS HAVE REALLY
THROWN A WRENCH INTO TODAY`S FORECAST. AT ANY RATE, THE MAIN
TROUGH AXIS WILL INCH CLOSER TO MIDDLE TENNESSEE OVERNIGHT, WITH
SCATTERED SHOWERS AND STORMS OCCURRING MAINLY DURING THE 06Z-12Z
PERIOD. LOOK FOR SCATTERED ACTIVITY TO CONTINUE TOMORROW AS THE
SURFACE FRONT ENTERS THE MID STATE DURING THE AFTERNOON.
PRECIPITATION WILL END FROM NW TO SE TOMORROW NIGHT AS WE GET A
BIG AIR MASS CHANCE, WITH SIGNIFICANTLY DRIER, COOLER AIR EVIDENT
BY TUESDAY. EXPECT DRY WEATHER FROM TUESDAY AT LEAST THROUGH
SUNDAY, WITH TEMPERATURES GRADUALLY WARMING THROUGHOUT THE WEEK AS
HIGH PRESSURE DOMINATES OUR WEATHER FOR A PROLONGED STRETCH. AT
THIS TIME, THE SPC CONTINUES TO FORECAST ONLY GENERAL
THUNDERSTORMS FOR MIDDLE TENNESSEE THROUGH TOMORROW NIGHT.

ROSE

&&

.OHX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$







FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE



 .SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 422 AM CDT MON SEP 2 2013

FORECAST CONCERNS ON CLOUD TRENDS TODAY.

UPPER TROF CONTINUES TO MOVE TO THE EAST THIS MORNING. SAT
IMAGERY SHOWING LOW CLOUDS DROPPING SOUTH THROUGH THE WESTERN
LAKES BEHIND SYSTEM. CLOUDS HAVE HAD A HARD TIME FILLING IN OVER
THE SOUTHERN CWA...ESPECIALLY IN THE EAST WHERE DOWNSLOPE
COMPONENT OF NW WINDS OPENING HOLES. SCATTERED LIGHT SHOWERS
CONTINUE OVER NORTH CENTRAL WI WITH RHI PICKING UP ANOTHER .01
LAST HOUR.

CANADIAN HIGH PRESSURE WILL CONTINUE TO MOVE SOUTHEAST INTO THE
STATE TODAY. INCREASING SUBSIDENCE AND ADVECTION OF DRIER AIR
INTO THE REGION SHOULD WORK TO ERODE THE CLOUDS THROUGH THE DAY.
DECREASING INVERSION HEIGHTS WILL ALSO LIMIT LAKE SUPERIOR CONTRIBUTION
TO THE CLOUDS AND PCPN. GEM REGIONAL AND HRRR APPEAR TO BE
HANDLING CURRENT CLOUD TRENDS AND HAVE LEANED TOWARDS THEIR
THOUGHTS OF CLEARING BY LATER AFTERNOON. WILL CONTINUE TO CARRY
SOME TRACE LIGHT SHOWERS OVER NORTH CENTRAL INTO THE LATER
MORNING. NO SIGNIFICANT CHANGE MADE TO PREVIOUS TEMP FORECAST.

SFC HIGH PRESSURE TO BE CONTROL WEATHER OVER STATE THROUGH TUE.
LOOKING FOR CLEAR SKIES AND LIGHT WINDS. HAVE TRENDED A BIT COOLER
TONIGHT IN THE TYPICAL COOLER LOCATIONS...THOUGH SHOULD SEE SIG
DIURNAL SWING FOR TUE FOR TEMPS TO RECOVER BACK TO NEAR SEASONAL
NORMS.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 422 AM CDT MON SEP 2 2013

THE UPPER LEVEL RIDGE AMPLIFYING OVER THE WESTERN CONUS IS THE
MAIN FEATURE DURING THIS PART OF THE FORECAST. SURFACE HIGH
PRESSURE OVER THE REGION AT THE START OF THE PERIOD WILL PUSH
SOUTHWARD AS A COLD FRONT MOVES THROUGH WISCONSIN MIDWEEK. ANY
UPPER LEVEL SUPPORT REMAINS FAR TO THE NORTHEAST AND THERE IS
LITTLE MOISTURE AROUND SO A DRY FRONTAL PASSAGE IS EXPECTED.
COOLER CONDITIONS BEHIND THE FRONT SHOULD NOT LAST LONG AS SURFACE
WINDS BECOME MORE SOUTHERLY AND BRING WARMER AIR BACK TO THE AREA.

ANOTHER COLD FRONT AND SOME WEAK SHORT WAVE ENERGY WILL BRING A
CHANCE FOR SHOWERS OR STORMS TO THE AREA...MAINLY EARLY NEXT WEEK.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1140 PM CDT SUN SEP 1 2013

COOL NORTH-NORTHWEST FLOW ACROSS WESTERN LAKE SUPERIOR WILL BRING
SCT LAKE-EFFECT RAIN SHOWERS AND MVFR/IFR CIGS TO MUCH OF NORTH
CENTRAL AND FAR NE WI OVERNIGHT INTO MONDAY MORNING. DAYTIME
HEATING AND THE ARRIVAL OF DRIER AIR SHOULD CAUSE CIGS TO RISE TO
VFR THERE BY LATE MORNING...FOLLOWED BY DECREASING CLOUDS LATE
IN THE DAY. VFR CONDITIONS SHOULD PREVAIL OVER MUCH OF EASTERN
WI...AIDED BY DOWNSLOPING NW WINDS.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TE
LONG TERM......MG
AVIATION.......KIECKBUSCH







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 322 AM CDT MON SEP 2 2013

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 322 AM CDT MON SEP 2 2013

CLOUDS TODAY/TEMPERATURES TODAY AND TONIGHT/FOG TONIGHT ALL TOPICS
OF CONCERN THROUGH THE SHORT TERM.

SATELLITE AND SURFACE ANALYSIS HAVE A 1002MB LOW PRESSURE  CENTERED
JUST NORTH OF LAKE HURON. CYCLONIC CIRCULATION ON THE BACKSIDE OF
THIS LOW WAS ROTATING A MASS OF STRATOCUMULUS SOUTHWARD ACROSS
NORTHERN MN/WI TOWARD THE FORECAST AREA. AS OF 3 AM...THE SOUTHERN
EXTENT/FRINGE OF THIS STRATOCUMULUS WAS APPROACHING THE I-94
CORRIDOR. SURFACE OBSERVATIONS WERE ALSO INDICATING SOME
INTERMITTENT VERY LIGHT RAIN SHOWER ACTIVITY WITHIN THIS CLOUD FIELD
ACROSS NORTHEAST WI.

WE WILL CONTINUE TO SEE THAT STRATOCUMULUS CLOUD FIELD INVADE THE
FORECAST AREA THROUGH THIS LABOR DAY MORNING...THEN SLOWLY ERODE
FROM WEST TO EAST THIS AFTERNOON AS A STRONG RIDGE OF HIGH PRESSURE
BUILDS IN FROM THE NORTHERN PLAINS. WAS CONTEMPLATING INCLUDING SOME
MENTION OF SHOWERS FOR AREAS NORTHEAST OF I-94 BUT THINK ANY CHANCES
SHOULD REMAINED CONFINED TO NORTHEAST WI IN DEEPER CYCLONIC FLOW.
OTHERWISE...925MB TEMPERATURES PRETTY COOL TODAY REACHING 14-16C
THIS AFTERNOON. THIS SHOULD RESULT IN HIGH TEMPERATURES TOPPING OFF
ONLY IN THE MIDDLE 60S ACROSS NORTH CENTRAL WI...AND LOWER 70S
ELSEWHERE ACROSS THE FORECAST AREA.

HIGH PRESSURE WILL BUILD OVERHEAD TONIGHT WITH CLEAR SKIES/CALM
WINDS/DRY AIRMASS SETTING UP IDEAL RADIATIONAL COOLING. THIS WILL
YIELD CHILLY OVERNIGHT LOWS OF AROUND 40 DEGREES IN THE FAVORED COLD
SPOT AREAS ALONG AND NORTH OF I-94...TO THE 45-50 DEGREE RANGE
ELSEWHERE. THIS SYNOPTIC SCENARIO WILL ALSO SET UP IDEAL RIVER
VALLEY FOG CONDITIONS WITH WIDESPREAD FOG EXPECTED TO FILL THE MAIN
STEM CHANNELS OF THE MISSISSIPPI/WISCONSIN RIVER AND THEIR
TRIBUTARIES.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 322 AM CDT MON SEP 2 2013

SURFACE HIGH PRESSURE SLOWLY MOVES SOUTHEAST TUESDAY SETTING UP
LIGHT SOUTH/SOUTHWEST WINDS ACROSS THE AREA. THIS DRAGS IN SLIGHTLY
WARMER AIR INTO THE REGION WITH HIGHS TOPPING OFF IN THE
MIDDLE/UPPER 70S.

NORTHWEST FLOW ALOFT PUSHES A WEAK MID-LEVEL TROUGH/SURFACE COLD
FRONT THROUGH THE AREA WEDNESDAY. THE NAM SEEMS TO BE THE ONLY MODEL
PRODUCING ANY RAINFALL WITH THIS TROUGH/FRONTAL PASSAGE. FOR NOW
WILL KEEP THE FORECAST DRY AS MOST OF THE MOISTURE IS CONFINED ABOVE
700MB AND LOWER LEVELS ARE VERY DRY. HEATING IN ADVANCE OF THE FRONT
SHOULD PUSH HIGHS IN THE LOWER/MIDDLE 80S.

GFS AND ECMWF REMAIN IN GOOD AGREEMENT WITH AN UPPER LEVEL RIDGE
OVER THE INTERMOUNTAIN WEST/HIGH PLAINS...AND NORTHWEST FLOW OVER
THE UPPER MISSISSIPPI RIVER VALLEY REGION THROUGH SATURDAY. THURSDAY/FRIDAY
LOOK DRY WITH SURFACE HIGH PRESSURE THE DOMINANT WEATHER FEATURE.
LOOK FOR HIGHS THURSDAY IN THE UPPER 70/LOWER 80S...WARMING INTO THE
LOWER/MIDDLE 80S ON FRIDAY. NORTHWEST FLOW ALOFT PUSHES ANOTHER WEAK
MID-LEVEL TROUGH/SURFACE COLD FRONT THROUGH ON SATURDAY.
SHOWER/THUNDER CHANCES...ALBEIT SMALL CHANCE...SEEMS TO BE CONFINED
MORE OVER EASTERN WI. DID GO WITH VERY SMALL CHANCES ACROSS OUR
CENTRAL WI COUNTIES ON THE WESTERN FRINGES OF BEST MOISTURE
CONVERGENCE ALONG THE FRONT. HEATING IN ADVANCE OF THIS FRONT
EXPECTED TO PRODUCE HIGHS ON SATURDAY IN THE MIDDLE/UPPER 80S.

BY SUNDAY...APPEARS LOW PRESSURE WILL BEGIN TO BREAK DOWN THE
WESTERN RIDGE WITH EASTERN FRINGES OF MOISTURE TRANSPORT/ISENTROPIC LIFT
REACHING OUR WESTERN AREAS ACROSS NORTH CENTRAL WI INTO SOUTHEAST MN
SEEING A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE AFTERNOON.

EXTENDED MODELS ACTUALLY SHOWING A DECENT SHOT AT SOME
SHOWERS/THUNDERSTORMS SUNDAY NIGHT INTO EARLY NEXT WEEK AS LOW
PRESSURE WORKS EAST OUT OF THE PLAINS AND ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1149 PM CDT SUN SEP 1 2013

SURFACE LOW REMAINS JUST TO THE EAST OF LAKE SUPERIOR WITH LARGE
SHIELD OF CLOUDS ON THE BACK SIDE OF THE LOW. CLOUDS CURRENTLY
COVERING NORTHERN WISCONSIN...NORTHEAST MINNESOTA INTO SOUTHERN
ONTARIO AND ARE ADVANCING TO THE SOUTHWEST. THE 02.00 NAM AND
02.03Z RAP CONTINUE THE TREND OF BRINGING THESE CLOUDS INTO THE
AREA OVERNIGHT BUT NOW SUGGEST THEY WILL LINGER LONGER INTO MONDAY
BEFORE MIXING OUT. BASED ON THE SATELLITE TRENDS...WILL BRING IN A
MVFR CEILING TO KLSE AN HOUR OR SO BEFORE IT PUSHES INTO KRST.
WITH BOTH MODELS NOW HANGING ONTO THE MOISTURE LONGER...HELD THE
CEILINGS IN UNTIL 18Z. HIGH PRESSURE WILL THEN BUILD IN FOR THE
REMAINDER OF THE PERIOD ALLOWING SKIES TO CLEAR OUT BY LATE
AFTERNOON/EARLY EVENING WITH WINDS BECOMING LIGHT OUT OF THE NORTH.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...

WI...NONE.
MN...NONE.
IA...NONE.

&&

$$

SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04










AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 1149 PM CDT SUN SEP 1 2013

.SHORT TERM...(TONIGHT THROUGH LABOR DAY)
ISSUED AT 215 PM CDT SUN SEP 1 2013

MAIN QUESTION TONIGHT IS CLOUD COVER. CURRENT CLOUD DECK HAS A
COUPLE ELEMENTS TO IT - MAIN MASS IN THE WRAP AROUND REGION WEST OF
AN EASTWARD MOVING SFC LOW...AND DIURNALLY DRIVEN CLOUDS ON THE
SOUTHERN FRINGES OF THIS MASS. THE DIURNAL CLOUD WILL DISSIPATE WITH
SUNDOWN...WHILE THE CLOUDS WITH THE LOW WILL MOVE EAST. HOWEVER...RH
FIELDS POINT TO A SAG SOUTH/SOUTHWEST OF SOME LOW LEVEL SATURATION
AS 925 MB WINDS KICK UP FROM THE NORTH/NORTHEAST AT 20 MPH LATER
TONIGHT. 01.09Z SREF PROBABILITIES ALSO POINT TO A HIGHER LIKELIHOOD
OF LOW CIGS ADVANCING SOUTHEAST...HIGHEST DOWN TO I-94...BUT COULD
WORK TO THE MISSISSIPPI RIVER. WILL INCREASE CLOUDS TONIGHT/EARLY
MONDAY BASED ON THESE TRENDS.

CLOUDS THAT MOVE IN SHOULD EXIT ON MONDAY AS HIGH PRESSURE STARTS TO
BUILD IN FROM THE WEST. THEY MAY NOT BE THAT QUICK TO EXIT NORTH
CENTRAL WI...WHICH COULD BE STUCK IN CLOUDS FOR A BETTER PART OF THE
DAYLIGHT HOURS. A COLD FRONT THAT PASSED ACROSS THE UPPER
MISSISSIPPI RIVER VALLEY TODAY WILL RESULT IN SOME MUCH
COOLER...DRIER AIR WORKING IN FOR LABOR DAY. SREF AND ECMWF 850 TEMP
ANOMALIES ARE AROUND -1 FOR MONDAY. HIGHS COULD STRUGGLE TO REACH 70
IN MANY LOCATIONS.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 215 PM CDT SUN SEP 1 2013

HIGH PRESSURE BUILDS OVERHEAD MONDAY NIGHT...CENTERED OVER THE LOCAL
AREA BY 12Z TUE. LOOKS LIKE A DECENT SETUP FOR FOG IN AREA RIVER
VALLEYS. NAM BUFKIT SOUNDINGS FAVOR IT A BIT MORE THAN THE GFS...BUT
ALL SUGGEST ITS PROBABLE...IF NOT LIKELY. WITH RAIN HAVING BEEN
SPARSE THE PAST COUPLE WEEKS...NOT CONFIDENT THAT FOG WILL DEVELOP
OUTSIDE OF THE RIVER VALLEYS.

GFS AND ECMWF IN GOOD AGREEMENT WITH AN UPPER LEVEL RIDGE TO THE
WEST...AND NORTHWEST FLOW OVER THE UPPER MISSISSIPPI RIVER VALLEY.
SOMEWHAT INACTIVE FLOW...WITH THE MODELS SUGGESTING THAT ANY
PERTURBATION IN THE FLOW WOULD MOVE SOUTH/NORTH OF THE LOCAL
FORECAST AREA. THUS...A CONTINUATION OF THE DRY CONDITIONS.

FOR THE WEEKEND THE RIDGE IS PROGGED TO SHIFT EASTWARD INTO THE
AREA...BUT COULD FLATTEN OUT AS IT DOES...THANKS TO AN UPPER LEVEL
SHORTWAVE TROUGH DRIVING ACROSS THE NORTHERN PLAINS. THIS TROUGH
SHOWS SOME PROMISE OF PCPN CHANCES FOR SUNDAY-MONDAY.

TEMPERATURES WILL GRADUALLY WARM THROUGH THE WEEK...AND COULD BE
FAIRLY WARM FOR THE FIRST WEEKEND OF SEPTEMBER AS WINDS BECOME MORE
SOUTHERLY/RIDGE WORKS IN.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1149 PM CDT SUN SEP 1 2013

SURFACE LOW REMAINS JUST TO THE EAST OF LAKE SUPERIOR WITH LARGE
SHIELD OF CLOUDS ON THE BACK SIDE OF THE LOW. CLOUDS CURRENTLY
COVERING NORTHERN WISCONSIN...NORTHEAST MINNESOTA INTO SOUTHERN
ONTARIO AND ARE ADVANCING TO THE SOUTHWEST. THE 02.00 NAM AND
02.03Z RAP CONTINUE THE TREND OF BRINGING THESE CLOUDS INTO THE
AREA OVERNIGHT BUT NOW SUGGEST THEY WILL LINGER LONGER INTO MONDAY
BEFORE MIXING OUT. BASED ON THE SATELLITE TRENDS...WILL BRING IN A
MVFR CEILING TO KLSE AN HOUR OR SO BEFORE IT PUSHES INTO KRST.
WITH BOTH MODELS NOW HANGING ONTO THE MOISTURE LONGER...HELD THE
CEILINGS IN UNTIL 18Z. HIGH PRESSURE WILL THEN BUILD IN FOR THE
REMAINDER OF THE PERIOD ALLOWING SKIES TO CLEAR OUT BY LATE
AFTERNOON/EARLY EVENING WITH WINDS BECOMING LIGHT OUT OF THE NORTH.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...04








AREA FORECAST DISCUSSION

NWS ALBANY NY

 1022 AM EDT MON SEP 2 2013

.SYNOPSIS...
ANOTHER WARM...HUMID AND WET DAY ACROSS THE AREA AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. THE BEST CHANCES FOR STORMS ARE
EXPECTED THIS AFTERNOON INTO THE EARLY EVENING. SOME STORMS WILL
PRODUCE VERY HEAVY DOWNPOURS. A DRIER AIRMASS WILL BE USHERED IN
LATE TONIGHT AND TUESDAY AS THE SYSTEM`S COLD FRONT MOVES ACROSS
THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1022 AM EDT...MUCH OF THIS MORNINGS SHOWERS AND
THUNDERSTORMS HAVE MOVED EAST OF THE AREA. HOWEVER...THERE IS
STILL A CLUSTER OF CONVECTION WITH HEAVY RAIN OVER DUTCHESS AND
LITCHFIELD COUNTIES LATE THIS MORNING. THIS ACTIVITY IS TIED TO A
SMALL-SCALE UPPER LEVEL DISTURBANCE SEEN WELL ON WATER VAPOR
IMAGERY. THIS AREA OF CONVECTION SHOULD CONTINUE TO SLOWLY MOVE
EASTWARD THROUGH EARLY AFTERNOON.

THEN ATTENTION SHIFTS TO THE WEST...WHERE ADDITIONAL SHOWER AND
THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ACROSS CENTRAL NY
ASSOCIATED WITH THE NEXT UPPER LEVEL DISTURBANCE OVER WESTERN NY
AND A PRE-FRONTAL TROUGH AT THE SURFACE. HI RES MODELS INCLUDING
THE 3KM HRRR AND OUR LOCAL HIRESWRF INDICATE CONVECTION INCREASING
IN COVERAGE BY EARLY TO MID AFTERNOON ACROSS THE AREA AS LARGE
SCALE ASCENT STRENGTHENS.

ONCE AGAIN THE MAIN THREAT WILL BE HEAVY RAINFALL AND POSSIBLE
FLASH FLOODING...AS PWATS ARE STILL RUNNING ANOMALOUSLY HIGH. THE
READING FROM THE 12Z KALB SOUNDING WAS 1.70 INCHES. GENERALLY
TALL/SKINNY CAPE PROFILE FAVORS THE HEAVY RAIN THREAT. DEPENDING
ON HOW MUCH LIMITED SUNSHINE CAN BREAK THROUGH THE CLOUDS...THERE
IS AN ADDITIONAL THREAT FOR STRONG GUSTY WINDS ASSOCIATED WITH
THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. THE BETTER THREAT
AREA APPEARS TO BE WESTERN/CENTRAL NY WHERE MORE CLEARING IS
TAKING PLACE. FOR OUR AREA EXPECTING AROUND 1000-1500 K/KG OF
SBCAPE TO BUILD...WITH DEEP LAYER SHEAR IN THE 25 TO 35 KT
RANGE...WHICH COULD RESULT IN SOME MORE ORGANIZED CLUSTERS OF
STORMS. WILL CONTINUE TO MONITOR TRENDS INTO THE AFTERNOON.

FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE TACONICS...THE
BERKSHIRES...LITCHFIELD COUNTY AND SOUTHERN VERMONT VALID INTO
EARLY THIS EVENING. PORTIONS OF THIS AREA RECEIVED HEAVY RAINFALL
SUNDAY AND AGAIN OVERNIGHT/THIS MORNING MAKING THEM VULNERABLE TO
FLASH FLOODING. HOWEVER....WE CAN NOT RULE OUT THE POSSIBILITY FOR
ISOLATED FLASH FLOODING ACROSS EAST CENTRAL NEW YORK TODAY BUT
FORECAST CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS
TIME.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
THE UPPER TROUGH STILL HAS TO SWING THROUGH AND IT WILL DO SO
TUESDAY AND TUESDAY NIGHT FINALLY MOVING OFF TO THE EAST AFTER
MIDNIGHT. EXPECTING SCATTERED SHOWERS ACROSS THE AREA AS THE TROUGH
AXIS APPROACHES. HEIGHTS WILL THEN RISE A BIT LATE TUESDAY NIGHT
INTO WEDNESDAY. HOWEVER...AN UPPER LEVEL LOW WILL DEVELOP OVER
HUDSON BAY CANADA DROPPING A REINFORCING COLD FRONT INTO THE REGION
WEDNESDAY NIGHT.

TEMPERATURES TUESDAY WILL BE SEASONABLY WARM...WITH MUCH MORE
COMFORTABLE DEW POINTS THAN RECENT DAYS...DROPPING INTO THE 50S.

TEMPERATURES WEDNESDAY WILL BE SIMILAR AND EVEN A BIT WARMER THAN
TUESDAY ACROSS THE HIGHER TERRAIN WITH THE HELP OF SOME SUNSHINE.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
THE EXTENDED FORECAST FOLLOWS CLOSELY THE HPC GUIDANCE THIS MORNING
DUE TO THE ACTIVE ONGOING WX.  THE MID WEEK INTO NEXT WEEKEND WILL
BE DOMINATED BY A MEAN LONGWAVE TROUGH.  THIS WILL PROVIDE THE
REGION WITH A PREVAILING NW FLOW ALOFT AND TEMPS NEAR NORMAL TO
BELOW NORMAL FOR THE STRETCH. HUMIDITY LEVELS WILL BE LOW AND
COMFORTABLE.

THU-FRI...A COLD FRONT DIPS SOUTH OF THE REGION WITH A COOL CANADIAN
AIR MASS BUILDING IN FROM THE GREAT LAKES REGION AND OHIO VALLEY.
H850 TEMPS FALL TO +2C TO +5C ACCORDING THE LATEST GFS THU NIGHT.
MAX TEMPS WILL RANGE FROM THE U50S TO M60S OVER THE SRN DACKS TO
LOWER TO M70S FROM THE CAPITAL REGION SOUTH AND EAST.  LOWS WILL BE
IN THE 40S WITH SOME 30S OVER THE DACKS.  FRIDAY WILL FEATURE LOTS
OF SUNSHINE AND TEMPS ABOUT 5-7 DEGREES BELOW NORMAL WITH MID AND
U60S OVER THE HILLS AND MTNS...AND L70S IN THE VALLEYS.

FRI NIGHT-SAT...THE SFC HIGH MOVES SOUTH AND EAST OF THE
REGION...AS A WARM FRONT BRIEFLY LIFTS THROUGH WITH LITTLE IF ANY
PCPN. LOWS WILL STILL BE IN THE M40S TO M50S. A COLD FRONT SLIDES
S/SE FROM SRN ONTARIO AND SWERN QUEBEC.  THE BEST CHC FOR SHOWERS
WILL BE FROM THE CAPITAL REGION NORTH AND WEST DURING THE DAY...AND
SLIGHT CHC VALUES TO THE SOUTH AND EAST. THE CONVERGENCE WITH THIS
BOUNDARY IS NOT VERY STRONG.

SATURDAY NIGHT INTO SUNDAY...THE COLD FRONT SINKS SOUTH OF THE FCST
AREA WITH A REINFORCING SURGE OF COOL...CANADIAN AIR. A SLIGHT TO
LOW CHC OF SHOWERS LINGERS INTO SUNDAY MORNING.  A BROAD ANTICYCLONE
SETTLES OVER NY AND NEW ENGLAND TO CLOSE THE WEEKEND AND OPEN NEXT
WEEK. TEMPS WILL FINISH NEAR SEASONABLE NORMALS.

OVERALL...PCPN LOOKS BELOW NORMAL WITH TEMPS SLIGHTLY BELOW NORMAL
IN THE LONG TERM.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
A STRONG UPPER LEVEL LOW WILL APPROACH FROM SOUTHEAST ONTARIO AND SW
QUEBEC DURING THE AFTERNOON. A SERIES OF BOUNDARIES ASSOCIATED WITH
THE UPPER LOW WILL IMPACT THE REGION INTO THIS EVENING WITH SHOWERS
AND THUNDERSTORMS.

LOW MVFR/IFR CONDITIONS WILL IMPACT THE TERMINALS THIS MORNING.
SCT-NUMEROUS SHOWERS AND THUNDERSTORMS WILL HAVE THE GREATEST IMPACT
AT KPSF/KALB/KGFL NORTHWARD PRIOR TO NOONTIME.

A SFC TROUGH WILL MOVE THROUGH THE REGION IN THE LATE MORNING INTO
THE EARLY PM...AND A COLD FRONT WILL FOLLOW FOR THE MID PM INTO
THE EARLY EVENING. CONDITIONS WILL BRIEFLY RISE BACK TO HIGH
MVFR/LOW VFR LEVELS BEFORE MORE SHOWERS AND THUNDERSTORMS IMPACT THE
TERMINALS WITH AT LEAST MVFR CONDITIONS. OUR CONFIDENCE WAS NOT
GREAT ENOUGH TO ADD THUNDERSTORMS YET...BUT LATER TAF ISSUANCES WILL
ADDRESS PM THUNDERSTORMS.

HIGH MVFR/VFR CONDITIONS MAY RETURN AFTER 00Z/TUE WITH THE SHOWERS
BEGINNING TO END WITH THE PASSAGE OF THE FIRST COLD FRONT.
HOWEVER...THE SKIES MAY CLEAR ENOUGH WITH MOISTURE LEFT IN THE
BOUNDARY LAYER FOR IFR/MVFR BR/FG AND STRATUS TO FORM AGAIN.

THE WINDS WILL BE LIGHT TO CALM THIS MORNING...THEN INCREASE FROM
THE SOUTH TO SOUTHEAST AT 5 TO 10 MPH BY THE AFTERNOON. THE WINDS
WILL VEER TO THE SOUTH TO SOUTHWEST AT LESS THAN 10 MPH LATE THIS
AFTERNOON INTO THE EARLY EVENING. THE WINDS MAY BE CALM AT MOST OF
THE TAF SITES TOWARDS MIDNIGHT WITH LIGHT WEST WINDS AT KALB.

OUTLOOK...
WED-FRI: NO OPERATIONAL IMPACT.  NO SIG WX.

&&

.FIRE WEATHER...
WARM...HUMID AND WET WEATHER WILL CONTINUE TODAY. A DRIER AIRMASS
WILL BE USHERED IN LATE TONIGHT INTO TUESDAY AS COLD FRONT MOVES
ACROSS THE REGION.

&&

.HYDROLOGY...
PRECIPITABLE WATER VALUES ARE HIGH CLOSE TO 2 INCHES SO VERY HEAVY
DOWNPOURS WILL OCCUR WITH SOME STORMS. WINDS WILL REMAIN LIGHT
RESULTING IN SLOW MOVEMENT OF THE STORMS.

HAVE DECIDED TO ISSUE A FLASH FLOOD WATCH FOR THE TACONICS...THE
BERKSHIRES...LITCHFIELD COUNTY AND SOUTHERN VERMONT VALID INTO EARLY
THIS EVENING. PORTIONS OF THIS AREA RECEIVED HEAVY RAINFALL SUNDAY
AND AGAIN OVERNIGHT/EARLY THIS MORNING MAKING THEM MORE VULNERABLE
TO FLASH FLOODING. HOWEVER....WE CAN NOT RULE OUT THE POSSIBILITY
FOR ISOLATED FLASH FLOODING ACROSS EAST CENTRAL NEW YORK TODAY BUT
FORECAST CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS
TIME.

A DRIER AIRMASS WILL FINALLY BE USHERED INTO THE REGION LATE
TONIGHT AND TUESDAY AS COLD FRONT MOVES ACROSS THE REGION.

WIDESPREAD PRECIPITATION IS NOT EXPECTED THIS WEEK AS HIGH PRESSURE
WILL DOMINATE MUCH OF THE TIME. HOWEVER...THERE WILL BE A COUPLE/FEW
FRONTAL PASSAGES WHICH WILL BRING THE THREAT OF SHOWERS TO THE AREA.

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...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ054-061-
     066.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VTZ013>015.

&&

$$
SYNOPSIS...IAA
NEAR TERM...IAA/JPV
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...WASULA
FIRE WEATHER...IAA
HYDROLOGY...IAA/WASULA








AREA FORECAST DISCUSSION

NWS MIAMI FL

 1104 AM EDT MON SEP 2 2013

...NUMEROUS THUNDERSTORMS DEVELOPING INTERIOR-EAST COAST METRO,
SOME WITH FREQUENT LIGHTNING/LOCALLY HEAVY RAINFALL...

.UPDATE...A STORMY LABOR DAY AFTERNOON IS EXPECTED. THE MIAMI
SOUNDING SHOWS A MOIST/UNSTABLE ATMOSPHERE WITH A PWAT OF 1.94
INCHES. LAPSE RATES AREN`T AS STEEP AS THEY WERE YESTERDAY WITH
WARMING ALOFT. THE H5 TEMP HAS WARMED BY ALMOST 2C SINCE
YESTERDAY. HOWEVER, ALREADY CONVECTION IS FIRING UP ALONG THE GULF
COAST SEA BREEZE. ONCE THIS MOVES INLAND AND THE ATLANTIC SEA
BREEZE DEVELOPS, THUNDERSTORMS WILL BECOME MOVE WIDESPREAD ACROSS
THE INTERIOR AND EAST COAST. MAY NEED TO INCREASE POPS EVEN MORE.
IF LATEST HRRR IS RIGHT, WIDESPREAD ACTIVITY WOULD DEVELOP. THE
MAIN IMPACTS TODAY WITH THE STORMS WILL BE FREQUENT LIGHTNING
STRIKES AND HEAVY RAIN/POTENTIAL ISOLATED STREET FLOODING DUE TO
SLOW STORM MOTION. THERE IS A LESSER RISK OF STRONG WIND GUSTS
THIS AFTERNOON COMPARED TO YESTERDAY, BUT STILL PRESENT.
/GREGORIA

&&

.PREV DISCUSSION... /ISSUED 827 AM EDT MON SEP 2 2013/

UPDATE...ACARS DATA SHOWS A SW-W LIGHT STEERING FLOW THROUGH THE
COLUMN. GPS MET DATA SHOWS PWATS IN THE 1.75-1.90 INCH RANGE
ACROSS SOUTH FL. THERE HAS BEEN LITTLE ENVIRONMENTAL CHANGES SINCE
YESTERDAY, SO HAVE INCREASED POPS WITH AN ORIENTATION FAVORING THE
INTERIOR AND EAST COAST...GIVEN THE AFOREMENTIONED STEERING FLOW.
NUMEROUS ACTIVITY HAS DEVELOPED OVER THE PAST FEW DAYS AND SEE NO
REASON TO DEVIATE FROM THIS TODAY WITH NUMEROUS THUNDERSTORMS
DEVELOPING INTERIOR AND ACROSS THE EAST COAST METROPOLITAN AREAS
JUST INLAND FROM THE COAST. /GREGORIA

PREV DISCUSSION... /ISSUED 730 AM EDT MON SEP 2 2013/

AVIATION...
MAINLY VFR CONDITIONS SHOULD PREVAIL. LIGHT AND VARIABLE WINDS
THIS MORNING WILL BECOME EASTERLY AT 5-10 KNOTS THIS AFTERNOON.
CONDITIONS ARE SIMILAR TO YESTERDAY...SO KEPT VCTS AFTER 16Z FOR
THE EAST COAST TERMINALS...EXCEPT KPBI. A FEW SHOWERS WERE NEAR
KAPF THIS MORNING...BUT THESE WILL DISSIPATE OVER THE NEXT COUPLE
OF HOURS. THE GULF COAST SEA BREEZE IS EXPECTED TO DEVELOP BY
EARLY AFTERNOON...AND SHOWERS AND STORMS SHOULD MOVE EAST OF KAPF.
SHOWERS AND STORMS ARE FORECAST TO DIMINISH IN THE EARLY
EVENING...WITH LIGHT AND VARIABLE WINDS AGAIN OVERNIGHT.

PREV DISCUSSION... /ISSUED 359 AM EDT MON SEP 2 2013/

DISCUSSION...
NO MAJOR SYNOPTIC SCALE CHANGES EXPECTED ACROSS SOUTH FLORIDA
THROUGH THE WEEK.

FLOW IS EXPECTED TO BE LIGHT THROUGH THE FIRST HALF OF THE WEEK AS
MID LEVEL RIDGING BUILDS ACROSS THE FLORIDA PENINSULA FROM THE
ATLANTIC. THIS SHOULD ALLOW FOR SEA BREEZE/OUTFLOW BOUNDARY
INTERACTIONS TO INDUCE AFTERNOON AND EARLY EVENING SHOWER AND
THUNDERSTORMS MAINLY ACROSS THE INTERIOR AND GULF COASTAL AREAS.
HOWEVER THE RIDGING SHOULD ALSO KEEP THE MID LEVELS OF THE
ATMOSPHERE WEAKLY CAPPED AND IS DEPICTED IN MODEL SOUNDINGS. THIS
SHOULD INHIBIT DEEP VERTICAL DEVELOPMENT OF AFTERNOON
THUNDERSTORMS. HEAT INDEX VALUES ARE ALSO EXPECTED TO BE ON THE
RISE THROUGH MIDWEEK AS A RESULT OF THE STRONGER RIDGING. BY
WEDNESDAY...MAXIMUM HEAT INDEX VALUES SHOULD BE AROUND 100 DEGREES
ACROSS THE EAST COAST METRO AREAS AND BETWEEN 105 AND 109 DEGREES
ACROSS INTERIOR COLLIER COUNTY.

EASTERLY FLOW SHOULD PREVAIL AGAIN BY THURSDAY AND REMAIN THROUGH
THE END OF THE WEEK. AT THIS TIME THE FLOW DOES NOT APPEAR TO BE
STRONG ENOUGH TO COUNTERACT THE DEVELOPMENT OF A GULF COAST SEA
BREEZE. THIS SHOULD KEEP MOST OF THE AFTERNOON CONVECTION TO MAINLY
THE INTERIOR AND GULF COAST.

THERE IS CURRENTLY A DISORGANIZED AREA OF CONVECTION ACROSS THE
LESSER ANTILLES THAT THE NATIONAL HURRICANE CENTER GIVES A 40
PERCENT CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT
48 HOURS AND A 50 PERCENT CHANCE DURING THE NEXT 5 DAYS. IT IS
CURRENTLY MOVING WEST-NORTHWEST AT ABOUT 10 MPH. CURRENT OPERATIONAL
MODELS BRING THIS SYSTEM ACROSS HISPANIOLA AS AN OPEN WAVE LATE IN
THE WEEK AND INTO THE WEEKEND.

AVIATION...
VFR CONDITIONS EXPECTED. VCTS ADDED AT AROUND 16-18Z AT ALL
TERMINALS. EASTERLY FLOW WILL PREVAIL ACROSS THE AREA...SLIGHTLY
INCREASING IN SPEED IN THE AFTERNOON. CURRENT GUIDANCE KEEPS
DEPICTING VCTS AFTER 18Z AT ALL TERMINALS...AND DUE TO SIMILAR
WEATHER CONDITIONS THAN PREVIOUS DAYS...WILL EXPECT THIS ACTIVITY
TO FORM. WEST COAST SEA BREEZE EXPECTED TO PUSH INLAND BY
16Z...WHICH WILL ALSO HELP IN THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THROUGH THE AFTERNOON AND EVENING. ALL ACTIVITY WILL
POSSIBLY DISSIPATE BY 00Z.

MARINE...
GENERALLY EAST TO SOUTHEAST WINDS AT LESS THAN 10 KNOTS WILL
PREVAIL ACROSS THE ATLANTIC WATERS THROUGH MIDWEEK WITH
CORRESPONDING SEAS AT 2 FEET OR LESS. FLOW IS EXPECTED TO BECOME
EASTERLY AND INCREASE SLIGHTLY THROUGH THE LATTER HALF OF THE WEEK
WITH SEAS ONLY IN THE 1 TO 3 FOOT RANGE.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  90  77  89  78 / 50 30 30 20
FORT LAUDERDALE  89  79  90  80 / 40 30 30 20
MIAMI            91  78  90  79 / 50 30 30 20
NAPLES           89  75  90  77 / 20 20 40 20

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$





AREA FORECAST DISCUSSION

NWS JACKSONVILLE FL

 951 AM EDT MON SEP 2 2013

.UPDATE...
TODAY WILL LIKELY BE SIMILAR TO YESTERDAY WITH ISOLATED SHOWERS
BEGINNING ALONG THE GULF COAST EARLY BUT NOT ADVANCING VERY FAR
INLAND UNTIL LATER IN THE MORNING. THE HRRR DEPICTS THE ACTIVITY
SPREADING NORTHEASTWARD EARLY AFTN AT SAME TIME SOME SHOWER/
STORMS BEGIN DEVELOPING ALONG THE ATLC SEABREEZE...WHICH WILL
REMAIN PINNED NEAR THE COAST DUE TO THE OFFSHORE FLOW. EXPECT
GUSTY WINDS AND TORRENTIAL RAINFALL FROM THE STRONGER STORMS.

&&

.AVIATION...
VFR IS EXPECTED EXCEPT IN AND NEAR TSRA. WILL SHOW VCTS AFTER 19Z
UNTIL AROUND 00Z.

&&

.MARINE...
BUOYS ARE AVERAGING WINDS 10-15 KTS WITH LOWER SPEEDS NEARSHORE
DUE TO SW OFFSHORE FLOW. A TIGHTER GRADIENT OVER GA WATERS HAS
KEPT WINDS HIGHER THERE AND GRAYS REEF TO OUR NORTH IS 16G17KT.
SEAS ARE RUNNING 1-3 FT. NO CHANGES EXPECTED IN THE UPDATE.
ANOTHER NOCTURNAL SURGE IS FORECAST WITH POSSIBLE SCEC CONDITIONS
FOR OFFSHORE LEGS.

RIP CURRENTS: LOW RISK DUR TO AN OFFSHORE FLOW.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  91  72  93  73 /  50  40  40  30
SSI  89  76  90  77 /  30  30  30  30
JAX  92  72  93  75 /  40  30  40  30
SGJ  90  74  91  75 /  40  30  40  40
GNV  92  71  92  73 /  30  20  40  30
OCF  92  71  93  73 /  20  10  30  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&

$$

TRABERT/GUILLET





AREA FORECAST DISCUSSION

NWS JACKSON KY

 1108 AM EDT MON SEP 2 2013

.UPDATE...
ISSUED AT 1108 AM EDT MON SEP 2 2013

LOW CLOUDS DEVELOPED AND BECAME MUCH MORE PREVALENT THIS MORNING THAN
WAS FORECAST. THIS SLOWED THE WARM-UP A BIT AND WILL DELAY DEVELOPMENT
OF SURFACE BASED DEEP CONVECTION.

UPDATE ISSUED AT 730 AM EDT MON SEP 2 2013

RAN A DATA LOAD AND BLEND TO MATCH UP THE CURRENT OBS AND TRENDS WITH
THE GRIDS. OTHERWISE...THE FORECAST IS ON TRACK AND UPDATES HAVE BEEN
SENT TO THE NDFD/WEB SERVERS.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM EDT MON SEP 2 2013

07Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING THROUGH THE OHIO VALLEY
WITH A COLD FRONT PRESSING INTO KENTUCKY FROM THE NORTHWEST. ON THE
OTHER SIDE OF THAT BOUNDARY COOLER AND MUCH DRIER AIR IS FOUND. EAST
KENTUCKY IS ON THE OPPOSITE SIDE GIVING US ANOTHER MUGGY AND MILD
NIGHT WITH TEMPS AND DEW POINTS WITHIN A FEW DEGREES OF 70. PLENTY OF
LOW LEVEL MOISTURE IS KEEPING SOME LOW LEVEL CLOUDS AROUND IN
ADDITION TO SUPPORTING THE DEVELOPMENT OF PATCHY VALLEY FOG...BUT THE
CONVECTION HAS REMAINED AT BAY.

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM. THEY
ALL TAKE A DECENT...FOR LATE SUMMER...TROUGH THROUGH THE GREAT LAKES
AND OHIO VALLEY FROM TODAY INTO TUESDAY. THIS WILL SUPPORT LOW
HEIGHTS AND SHORT WAVE ENERGY PASSING THROUGH THE REGION TODAY AND
TONIGHT. THE TROUGH AXIS DOES GO THROUGH EAST KENTUCKY BY TUESDAY
MORNING...THOUGH...AND THIS WILL BE FOLLOWED BY RISING HEIGHTS IN
THE WAKE OF THE TROUGH. THE MESOSCALE WILL STILL DOMINATE OUR WEATHER
WITH DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES HELPING TO DRIVE THE
CONVECTION AHEAD OF THE COLD FRONT THAT WILL PUSH THROUGH EAST
KENTUCKY LATER TONIGHT. ACCORDINGLY...HAVE LEANED TOWARD THE HIGHER
RESOLUTION NAM12 FOR WEATHER DETAILS...BUT MORE BROAD BRUSHED WITH
THE SPECIFICS...ALONG WITH USING THE HRRR FOR THE NEAR TERM.

SENSIBLE WEATHER WILL FEATURE A RECHARGING OF THE AIR MASS OVER EAST
KENTUCKY TODAY WITH BUILDING INSTABILITY AHEAD OF THAT FRONT. THIS
SHOULD YIELD SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY
MID AFTERNOON. GRADUALLY THE CONVECTION WILL SHRINK SOUTHEAST DURING
THE EVENING HOURS AS THE FRONT PUSHES THE DEEPER MOISTURE OUT OF THE
AREA. AS A RESULT...HAVE MAXED OUT POPS NEAR 00Z FOR THE AREA WITH A
TAPERING FROM NORTHWEST TO SOUTHEAST THEREAFTER. COOLER AIR FILTERING
INTO THE STATE IN THE WAKE OF THE FRONT WILL LEAD TO LOWER TEMPS IN
THE NORTHWEST PARTS OF THE CWA BY TUESDAY MORNING...THOUGH MUGGY
VALUES WILL REMAIN TO THE SOUTH AND EAST. DRIER AIR TAKES OVER ON
TUESDAY BRINGING A NICE CHANGE...MAKING FOR A PLEASANTLY DRY AND
COOLER DAY.

AGAIN USED THE CONSSHORT AND ITS BC VERSION FOR A STARTING POINT WITH
THE DEW POINT AND WIND GRIDS...RESPECTIVELY...UNTIL 00Z TUESDAY...
FOLLOWED THE CONSALL FOR THE REST. FOR TEMPS...ADJUSTED THE CONSALL
FOR SOME MINOR TERRAIN ENHANCEMENTS IN THE LOWS TONIGHT WITH THE
HOURLY DIURNAL CURVE DERIVED FROM THE NAM12. AS FOR POPS...ENDED UP
CLOSER TO THE WETTER MAV GUIDANCE TODAY...AND SIMILAR TO BOTH
TONIGHT...THEN DRY ON TUESDAY.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 2 2013

NOT A LOT OF CHANGE FOR THE EXTENDED PERIOD. TUESDAY NIGHT/WEDNESDAY
SHOULD BEGIN WITH UPPER LEVEL TROUGHING AND SURFACE HIGH PRESSURE IN
PLACE WITH LIGHT WINDS. THE ONLY MOISTURE AVAILABLE IN THE
ATMOSPHERE WILL BE IN THE UPPER LEVELS WEDNESDAY AFTERNOON...WITH
ABUNDANT DRYING BELOW. AS A RESULT...SOME CIRRUS CLOUDS WILL BE
PRESENT...BUT OTHERWISE WEATHER WILL BE QUITE BENIGN. COOLER AND
DRIER AIR FLOWING IN FROM CANADA WILL KEEP HIGH TEMPS AND HUMIDITY
AT BAY.

FOR THURSDAY...MUCH OF THE SAME IS EXPECTED THROUGH THE FIRST HALF
OF THE DAY. THEN...AS WAS MENTIONED IN PREVIOUS FORECAST...AN
IMPULSE DROPPING INTO A LARGE UPPER TROUGH OVER THE NE CONUS AND SE
CANADA WILL SEND ANOTHER COLD FRONT SOUTH TOWARD THE LOCAL AREA
THURSDAY AFTERNOON OR THURSDAY NIGHT. HOWEVER... VIRTUALLY NO LOW
LEVEL MOISTURE RETURN IS EXPECTED...AND THE FRONT SHOULD BE DYING
OUT AS IT APPROACHES...WITH ALMOST NO IMPACT ON OUR LOCAL
WEATHER. AS THE FRONT DIES...HIGH PRESSURE DROPPING IN BEHIND IT
WILL MERGE WITH HIGH PRESSURE ORIGINALLY TO THE SOUTH OF THE
FRONT...WITH THE LOCAL RESULT BEING DRY WEATHER UNDER ITS DOMINANCE
THROUGH AT LEAST FRIDAY NIGHT.

A WEAK DISTURBANCE WILL TRY TO MOVE THROUGH THE OHIO VALLEY AND ERN
KY LATE IN THE WEEKEND. HOWEVER AT THIS POINT...LATEST GFS SOUNDINGS
ARE STILL LOOKING RATHER LACKLUSTER FOR ANY WIDESPREAD PRECIP
CHANCES. THE GFS IS STILL TRYING TO PINPOINT SOME AFTERNOON
CONVECTION OVER THE HIGHER APPALACHIAN TERRAIN THROUGH THE
WEEKEND...REACHING INTO THE FAR SE COALFIELDS OF KY. THE ECMWF HAS
THE SAME IDEA...BUT CONTINUES TO KEEP ALL PRECIP CHANCES TO OUR SE
OVER THE HIGHER APPALACHIAN TERRAIN. ALL THINGS CONSIDERED...WITH
LITTLE AGREEMENT OR SYNOPTIC SUPPORT...WILL CONTINUE WITH ONLY
SLIGHT CHANCE POPS AT BEST FOR THE FAR SE COUNTIES DURING THE
WEEKEND. ELSEWHERE...THE RETURN OF MORE SRLY FLOW WILL ALLOW
TEMPERATURES TO INCREASE SLIGHTLY THROUGHOUT THE WEEKEND...REACHING
THE MID AND UPPER 80S. HUMIDITY VALUES ON THE OTHER HAND WILL REMAIN
AT BAY...KEEPING CONDITIONS WARM BUT PLEASANT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 740 AM EDT MON SEP 2 2013

THE LOWER CIGS HAVE NOW MOVED OFF TO THE EAST SO VFR CONDITIONS
SHOULD PREVAIL FOR THE BULK OF THE PERIOD. THERE REMAINS TOO MUCH
UNCERTAINTY WITH TIMING AND COVERAGE OF ANY FRESH CONVECTION LATER
TODAY TO GO ANY MORE SPECIFIC THAN JUST A VCTS AT THE TAF SITES
THROUGH THE DAY. ACCOMPANYING THE STORMS COULD BE MVFR CIGS AND VIS.
THE STORM THREAT SHOULD END FROM NORTHWEST TO SOUTHEAST ACROSS THE
AREA BETWEEN 00 AND 02Z. SOME MVFR FOG COULD DEVELOP AROUND 08Z
TONIGHT AT LOZ...BUT THE OTHER SITES WILL LIKELY REMAIN CLEAR.
OUTSIDE OF ANY STORMS...WINDS WILL BE LIGHT AND VARIABLE...THOUGH
FAVORING THE WEST DURING THE AFTERNOON AND EVENING.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF







AREA FORECAST DISCUSSION...UPDATED

NWS JACKSON KY

 740 AM EDT MON SEP 2 2013

.UPDATE...
ISSUED AT 730 AM EDT MON SEP 2 2013

RAN A DATA LOAD AND BLEND TO MATCH UP THE CURRENT OBS AND TRENDS WITH
THE GRIDS. OTHERWISE...THE FORECAST IS ON TRACK AND UPDATES HAVE BEEN
SENT TO THE NDFD/WEB SERVERS.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM EDT MON SEP 2 2013

07Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING THROUGH THE OHIO VALLEY
WITH A COLD FRONT PRESSING INTO KENTUCKY FROM THE NORTHWEST. ON THE
OTHER SIDE OF THAT BOUNDARY COOLER AND MUCH DRIER AIR IS FOUND. EAST
KENTUCKY IS ON THE OPPOSITE SIDE GIVING US ANOTHER MUGGY AND MILD
NIGHT WITH TEMPS AND DEWPOINTS WITHIN A FEW DEGREES OF 70. PLENTY OF
LOW LEVEL MOISTURE IS KEEPING SOME LOW LEVEL CLOUDS AROUND IN
ADDITION TO SUPPORTING THE DEVELOPMENT OF PATCHY VALLEY FOG...BUT THE
CONVECTION HAS REMAINED AT BAY.

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM. THEY
ALL TAKE A DECENT...FOR LATE SUMMER...TROUGH THROUGH THE GREAT LAKES
AND OHIO VALLEY FROM TODAY INTO TUESDAY. THIS WILL SUPPORT LOW
HEIGHTS AND SHORT WAVE ENERGY PASSING THROUGH THE REGION TODAY AND
TONIGHT. THE TROUGH AXIS DOES GO THROUGH EAST KENTUCKY BY TUESDAY
MORNING...THOUGH...AND THIS WILL BE FOLLOWED BY RISING HEIGHTS IN
THE WAKE OF THE TROUGH. THE MESOSCALE WILL STILL DOMINATE OUR WEATHER
WITH DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES HELPING TO DRIVE THE
CONVECTION AHEAD OF THE COLD FRONT THAT WILL PUSH THROUGH EAST
KENTUCKY LATER TONIGHT. ACCORDINGLY...HAVE LEANED TOWARD THE HIGHER
RESOLUTION NAM12 FOR WEATHER DETAILS...BUT MORE BROAD BRUSHED WITH
THE SPECIFICS...ALONG WITH USING THE HRRR FOR THE NEAR TERM.

SENSIBLE WEATHER WILL FEATURE A RECHARGING OF THE AIR MASS OVER EAST
KENTUCKY TODAY WITH BUILDING INSTABILITY AHEAD OF THAT FRONT. THIS
SHOULD YIELD SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY
MID AFTERNOON. GRADUALLY THE CONVECTION WILL SHRINK SOUTHEAST DURING
THE EVENING HOURS AS THE FRONT PUSHES THE DEEPER MOISTURE OUT OF THE
AREA. AS A RESULT...HAVE MAXED OUT POPS NEAR 00Z FOR THE AREA WITH A
TAPERING FROM NORTHWEST TO SOUTHEAST THEREAFTER. COOLER AIR FILTERING
INTO THE STATE IN THE WAKE OF THE FRONT WILL LEAD TO LOWER TEMPS IN
THE NORTHWEST PARTS OF THE CWA BY TUESDAY MORNING...THOUGH MUGGY
VALUES WILL REMAIN TO THE SOUTH AND EAST. DRIER AIR TAKES OVER ON
TUESDAY BRINGING A NICE CHANGE...MAKING FOR A PLEASANTLY DRY AND
COOLER DAY.

AGAIN USED THE CONSSHORT AND ITS BC VERSION FOR A STARTING POINT WITH
THE DEWPOINT AND WIND GRIDS...RESPECTIVELY...UNTIL 00Z TUESDAY...
FOLLOWED THE CONSALL FOR THE REST. FOR TEMPS...ADJUSTED THE CONSALL
FOR SOME MINOR TERRAIN ENHANCEMENTS IN THE LOWS TONIGHT WITH THE
HOURLY DIURNAL CURVE DERIVED FROM THE NAM12. AS FOR POPS...ENDED UP
CLOSER TO THE WETTER MAV GUIDANCE TODAY...AND SIMILAR TO BOTH
TONIGHT...THEN DRY ON TUESDAY.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 2 2013

NOT A LOT OF CHANGE FOR THE EXTENDED PERIOD. TUESDAY NIGHT/WEDNESDAY
SHOULD BEGIN WITH UPPER LEVEL TROUGHING AND SURFACE HIGH PRESSURE IN
PLACE WITH LIGHT WINDS. THE ONLY MOISTURE AVAILABLE IN THE
ATMOSPHERE WILL BE IN THE UPPER LEVELS WEDNESDAY AFTERNOON...WITH
ABUNDANT DRYING BELOW. AS A RESULT...SOME CIRRUS CLOUDS WILL BE
PRESENT...BUT OTHERWISE WEATHER WILL BE QUITE BENIGN. COOLER AND
DRIER AIR FLOWING IN FROM CANADA WILL KEEP HIGH TEMPS AND HUMIDITY
AT BAY.

FOR THURSDAY...MUCH OF THE SAME IS EXPECTED THROUGH THE FIRST HALF
OF THE DAY. THEN...AS WAS MENTIONED IN PREVIOUS FORECAST...AN
IMPULSE DROPPING INTO A LARGE UPPER TROUGH OVER THE NE CONUS AND SE
CANADA WILL SEND ANOTHER COLD FRONT SOUTH TOWARD THE LOCAL AREA
THURSDAY AFTERNOON OR THURSDAY NIGHT. HOWEVER... VIRTUALLY NO LOW
LEVEL MOISTURE RETURN IS EXPECTED...AND THE FRONT SHOULD BE DYING
OUT AS IT APPROACHES...WITH ALMOST NO IMPACT ON OUR LOCAL
WEATHER. AS THE FRONT DIES...HIGH PRESSURE DROPPING IN BEHIND IT
WILL MERGE WITH HIGH PRESSURE ORIGINALLY TO THE SOUTH OF THE
FRONT...WITH THE LOCAL RESULT BEING DRY WEATHER UNDER ITS DOMINANCE
THROUGH AT LEAST FRIDAY NIGHT.

A WEAK DISTURBANCE WILL TRY TO MOVE THROUGH THE OHIO VALLEY AND ERN
KY LATE IN THE WEEKEND. HOWEVER AT THIS POINT...LATEST GFS SOUNDINGS
ARE STILL LOOKING RATHER LACKLUSTER FOR ANY WIDESPREAD PRECIP
CHANCES. THE GFS IS STILL TRYING TO PINPOINT SOME AFTERNOON
CONVECTION OVER THE HIGHER APPALACHIAN TERRAIN THROUGH THE
WEEKEND...REACHING INTO THE FAR SE COALFIELDS OF KY. THE ECMWF HAS
THE SAME IDEA...BUT CONTINUES TO KEEP ALL PRECIP CHANCES TO OUR SE
OVER THE HIGHER APPALACHIAN TERRAIN. ALL THINGS CONSIDERED...WITH
LITTLE AGREEMENT OR SYNOPTIC SUPPORT...WILL CONTINUE WITH ONLY
SLIGHT CHANCE POPS AT BEST FOR THE FAR SE COUNTIES DURING THE
WEEKEND. ELSEWHERE...THE RETURN OF MORE SRLY FLOW WILL ALLOW
TEMPERATURES TO INCREASE SLIGHTLY THROUGHOUT THE WEEKEND...REACHING
THE MID AND UPPER 80S. HUMIDITY VALUES ON THE OTHER HAND WILL REMAIN
AT BAY...KEEPING CONDITIONS WARM BUT PLEASANT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 740 AM EDT MON SEP 2 2013

THE LOWER CIGS HAVE NOW MOVED OFF TO THE EAST SO VFR CONDITIONS
SHOULD PREVAIL FOR THE BULK OF THE PERIOD. THERE REMAINS TOO MUCH
UNCERTAINTY WITH TIMING AND COVERAGE OF ANY FRESH CONVECTION LATER
TODAY TO GO ANY MORE SPECIFIC THAN JUST A VCTS AT THE TAF SITES
THROUGH THE DAY. ACCOMPANYING THE STORMS COULD BE MVFR CIGS AND VIS.
THE STORM THREAT SHOULD END FROM NORTHWEST TO SOUTHEAST ACROSS THE
AREA BETWEEN 00 AND 02Z. SOME MVFR FOG COULD DEVELOP AROUND 08Z
TONIGHT AT LOZ...BUT THE OTHER SITES WILL LIKELY REMAIN CLEAR.
OUTSIDE OF ANY STORMS...WINDS WILL BE LIGHT AND VARIABLE...THOUGH
FAVORING THE WEST DURING THE AFTERNOON AND EVENING.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...GREIF





AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 1143 AM EDT MON SEP 2 2013

LATEST UPDATE...
UPDATE/MARINE

.SYNOPSIS...
ISSUED AT 324 AM EDT MON SEP 2 2013

A COLD FRONT IS MOVING THROUGH LOWER MICHIGAN EARLY THIS MORNING.
MUCH DRIER AND COOLER AIR WILL FLOW INTO THE REGION TODAY RESULTING
IN HIGHS IN THE LOWER TO MID 70S AND MUCH LOWER HUMIDITY.
TEMPERATURES WILL SLOWLY WARM TO THE LOWER 80S BY THE END OF THE
WEEKEND. DRY WEATHER IS EXPECTED THIS WEEK.

&&

.UPDATE...
ISSUED AT 1142 AM EDT MON SEP 2 2013

MODELS ARE FORECASTING A FAIR AMOUNT OF MOISTURE IN BOTH THE
925-850MB AND THE 950-900MB LAYERS. DEEP CYCLONIC FLOW WILL REMAIN
IN PLACE THROUGH THE COURSE OF THE AFTERNOON AS WELL WITH DELTA
T/S OVER LAKE MICHIGAN ON THE ORDER OF 14 DEGREES C. ALL OF THESE
FACTORS LEAD TOWARD A DECENT AMOUNT OF CLOUD COVER. EXPECT SKIES
TO STAY MAINLY CLOUDY IN THE NORTHERN PORTION OF THE FORECAST
AREA (U.S. 10)...BECOMING MOSTLY CLOUDY IN THE CENTRAL (I-96) AND
VARYING CONDITIONS IN THE SOUTH (I-94) BETWEEN PARTLY SUNNY AND
MOSTLY CLOUDY.

THE CLOUDS AND COLD AIR ADVECTION SHOULD KEEP HIGHS BELOW NORMALS
FOR THIS TIME OF YEAR. HIGHS WILL TOP OUT IN THE MID TO UPPER 60S
NORTH AND MID 70S IN THE FAR SOUTH. CANNOT RULE OUT A FEW
SPRINKLES OFF OF LAKE MICHIGAN THIS AFTERNOON AND EVENING BUT HAVE
NOT PUT THEM IN THE FORECAST AT THIS POINT.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 324 AM EDT MON SEP 2 2013

FORECAST CONCERNS ARE MINIMAL THIS MORNING AS DRY WX IS EXPECTED
THROUGH THE PERIOD.

SFC ANALYSIS SHOWS A COLD FRONT HAS PUSHED THROUGH THE CWA. THE LAST
OF THE SHOWERS THAT DEVELOPED AHEAD OF THE FRONT HAVE ALSO MOVED
EAST OUT OF THE CWA. IR LOOP SHOWS CLEAR SKIES MOVING IN BEHIND THE
FRONT. THAT WILL BE SHORT LIVED THOUGH BECAUSE A LARGE AREA OF
STRATOCU OVER ONTARIO/NRN LWR IS MOVING SOUTH ON THE HEELS OF A
NORTH WIND. H9 RH PROGS SUGGEST THAT QUITE A BIT OF CLOUDINESS
WILL BE WITH US THROUGH TONIGHT COURTESY OF A STRONG SHORT WAVE
MOVING ACROSS NRN LAKE HURON. A LARGE DOME OF HIGH PRESSURE OVER
THE CENTRAL ROCKIES WILL RESULT IN NW FLOW OVER THE GREAT LAKES.
THIS IS USUALLY A DRY FLOW AND THAT/S WHAT WE/LL SEE THROUGH
WEDNESDAY. AFTER THE SHORT WAVE MOVES EAST LATE TONIGHT...CLEARING
WILL OCCUR.

HIGHS TODAY WILL RUN FROM THE MID 60S IN THE NORTH TO MID 70S IN THE
SOUTH. WE/LL SEE A GRADUAL WARMING TREND THROUGH WEDNESDAY AS SOME
WARMER AIR FROM THE PLAINS GETS PUSHED NEWD TOWARD THE GREAT LAKES
AHEAD OF THE NEXT FRONT MIDWEEK.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 324 AM EDT MON SEP 2 2013

NOT MUCH IN THE WAY OF WEATHER IN THE EXTENDED AS ONLY A SLIGHT
CHANCE OF RAIN EXPECTED WITH A COLD FRONT PASSAGE ON SATURDAY. THE
ECMWF IS NOW A BIT QUICKER THAN THE GFS WITH SHOWERS COMING IN
FRIDAY NIGHT. KEPT POPS LIMITED TO SATURDAY.

WEDNESDAY NIGHT OR THURSDAY COULD ALSO HAVE A FEW SHOWERS AS A COLD
FRONT COMES THROUGH...BUT IT IS WEAKENING AND MOISTURE IS LIMITED SO
DECIDED TO KEEP THOSE PERIODS DRY FOR NOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 745 AM EDT MON SEP 2 2013

SOME MVFR AND IFR CEILINGS WILL BE GIVING WAY TO VFR CONDITIONS
THIS MORNING AS LOW STRATUS DECK DECREASES. NORTH WINDS WILL GUST
TO 15 TO 20 KNOTS AT TIMES.


&&

.MARINE...
ISSUED AT 1142 AM EDT MON SEP 2 2013

WINDS BENT MORE OFF SHORE THIS MORNING AND WHILE WAVES WERE UP
INITIALLY AT THE BEACHES THEY HAVE DROPPED SOME MID TO LATE
MORNING. THE HRRR FORECASTS THE WINDS TO COME BACK TO ABOUT 340
DEGREES OR FROM THE NORTH-NORTHWEST THIS AFTERNOON AND EVENING.
THEREFORE NO CHANGES WERE MADE TO THE SMALL CRAFT ADVISORY OR THE
BEACH HAZARDS STATEMENT. WHILE THE DIRECTION IS NOT IDEAL FOR HIGH
WAVES RIGHT AT THE SHORE IT SHOULD BE GOOD ENOUGH TO PRODUCE 3-5
FOOTERS AS WE HEAD THROUGH THE COURSE OF THE AFTERNOON AND
EVENING. STRUCTURAL CURRENTS AND LONGSHORE CURRENTS WILL BECOME
MORE OF A PLAYER TOO AS THE WINDS BACK. THE HIGHEST WAVES IN THIS
FLOW REGIME WILL BE NORTH OF WHITEHALL AND SOUTH OF HOLLAND. AS
EXPECTED...THE CLOUDS AND COOL TEMPERATURES HAVE KEPT BEACH
POPULATION DOWN WITH THE SURF CAM AT GRAND HAVEN SHOWING LIMITED
FOLKS ON THE BEACH. FOR THOSE ON THE BEACH HOWEVER CONDITIONS WILL
BECOME MORE HAZARDOUS AS WE HEAD THROUGH THE DAY...ESPECIALLY
BEACHES ON THE NORTH SIDES OF NORTH PIERS AND BREAKWALLS.

&&

.HYDROLOGY...
ISSUED AT 324 AM EDT MON SEP 2 2013

NO HYDRO CONCERNS. DRY WEATHER IS EXPECTED THIS WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR MIZ037-
     043-050-056-064-071.

LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.

&&

$$

UPDATE...DUKE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...93
MARINE...DUKE







AREA FORECAST DISCUSSION

NWS JACKSON MS

 902 AM CDT MON SEP 2 2013

.UPDATE...

A COMPLEX OF SHOWERS/THUNDERSTORMS AFFECTING THE HIGHWAY 82
CORRIDOR...ESPECIALLY IN THE DELTA REGION IS BRINGING HIGH COVERAGE
OF RAINFALL AND HAVE INCREASED POPS TO REFLECT THIS. THE EXPECTATION
IS THAT THIS COMPLEX WILL DIMINISH AS IT MOVES SOUTHEAST INTO A MORE
STABLE MID LEVEL ENVIRONMENT LATER THIS MORNING AND EARLY AFTERNOON.
WITH STRONG AFTERNOON HEATING...STORMS COULD ERUPT ALONG ANY
DIFFERENTIAL/OUTFLOW BOUNDARIES PRODUCED BY THIS COMPLEX...HOWEVER
THE HRRR AND ASSORTMENT OF WRF GUIDANCE ARE STINGY WITH ADDITIONAL
CONVECTIVE DEVELOPMENT LATER THIS AFTN. SO CONFIDENCE IN CONVECTIVE
BEHAVIOR/EVOLUTION TODAY IS LOWER THAN USUAL. /EC/

&&

.PREV DISCUSSION... /ISSUED 405 AM CDT MON SEP 2 2013/

SHORT TERM...TODAY THROUGH TUESDAY NIGHT...UPPER RIDGING THAT HAS
BEEN PRESENT OVER OUR REGION THIS WEEKEND WILL CONTINUE TO
RETROGRADE TO THE WEST. IN ADDITION...AN UPPER TROUGH WILL BE
SITUATED ACROSS THE OHIO VALLEY/EASTERN THIRD OF THE UNITED STATES.
THIS WILL LEAVE THE ARKLAMISS REGION BETWEEN THESE TWO UPPER LEVEL
FEATURES AND GENERALLY UNDER NORTHWEST FLOW ALOFT. THIS WILL HELP TO
BRING A SHORTWAVE TROUGH INTO OUR REGION TODAY AHEAD OF A FRONTAL
BOUNDARY. THIS TROUGH LOOKS TO BE RESPONSIBLE FOR THE CONVECTION
CONTINUING ACROSS PORTIONS OF THE MID SOUTH EARLY THIS MORNING.
MODELS INDICATE THAT CONVECTION SHOULD CONTINUE TO DEVELOP THROUGH
THE DAY IN ASSOCIATION WITH THIS SHORTWAVE TROUGH...THE APPROACHING
FRONTAL BOUNDARY...AND LEFTOVER MESOSCALE OUTFLOW BOUNDARIES PRESENT
ACROSS THE AREA. GIVEN COOL MIDLEVEL TEMPERATURES AROUND -6 TO -8C
PRESENT ACROSS THE REGION LEADING TO VERTICAL TOTALS AROUND
28-29C...AMPLE MOISTURE...AND SUFFICIENT DAYTIME HEATING...
CONVECTION WILL INCREASE LATER THIS AFTERNOON ITO THE EVENING. SOME
OF THE STORMS COULD BE SEVERE GIVEN THE BETTER LAPSE RATES AND WILL
CONTINUE TO ADVERTISE THIS POTENTIAL...ESPECIALLY GIVEN THE LABOR
DAY HOLIDAY. THE BEST CONDITIONS APPEAR TO BE NORTH OF I-20 AND
ESPECIALLY NORTH OF HIGHWAY 82 CORRIDOR.

WITH THE FRONTAL BOUNDARY LINGERING ACROSS THE REGION...SHOWERS AND
STORMS WILL LINGER THROUGH THE NIGHT AND INTO TUESDAY ALONG AND
SOUTH OF THE FRONT. BEHIND THE FRONT...DRIER AIR WILL BEING TO
FILTER INTO THE REGION ON TUESDAY. THIS...ALONG WITH COOLER LOW
LEVEL TEMPERATURES...WILL HELP TO MAKE FOR A RATHER PLEASANT DAY ON
TUESDAY FOR LOCATIONS ESPECIALLY NORTH OF I-20/HIGHWAY 82. BY 12Z
WEDNESDAY...MODEL PW VALUES SHOW LOCATIONS SOUTH OF I-20 SEEING
VALUES AROUND 1.5 INCHES...WHEREAS LOCATIONS NORTH OF I-20 WILL BE
AROUND 1-1.3 INCHES. GUIDANCE HAS CONTINUOUSLY BEEN SHOWING MUCH
COOLER TEMPERATURES ON TUESDAY WITH ENSEMBLE MEANS AROUND THE UPPER
80S FOR HIGHWAY 82 CORRIDOR. CONTINUED THE TREND OF CUTTING MAV
GUIDANCE BY A DEGREE OR TWO IN ACCORDANCE WITH THIS AIRMASS BEING
BEHIND THE BOUNDARY. THE MORE NOTICEABLE CHANGE WILL COME IN
OVERNIGHT LOWS. LOWS ON TUESDAY NIGHT WILL BE IN THE MID TO LOWER
60S ACROSS THE NORTHERN COUNTIES. /28/

LONG TERM...WEDNESDAY THROUGH SUNDAY...THE CWA WILL BE DIVIDED IN
HALF THROUGH MUCH OF THE LONG TERM WITH A DRIER AIRMASS AND VERY
LITTLE CHANCE FOR RAIN ACROSS THE NORTH WITH DEEP MOISTURE AND
GREATEST RAIN CHANCES CONTINUING ACROSS THE SOUTH.  COME WEDNESDAY
MORNING A LARGE MID LEVEL(595DAM) HIGH WILL BE CENTERED OVER
COLORADO WITH A 1020MB SURFACE RIDGE CENTERED OVER THE TENNESSEE AND
OHIO VALLEYS. A STALLED COLD FRONT IS EXPECTED TO BE DRAPED ACROSS
THE SOUTHERN PORTIONS OF OUR CWA. A DRIER AIRMASS WITH PWS BELOW AN
INCH AND A HALF AND MID 60 SURFACE DEWPOINTS WILL RESIDE NORTH OF
THE FRONT WHILE NEAR TWO INCH PWS AND LOWER 70 DEW POINTS CONTINUE
ACROSS THE SOUTHERN THIRD OF OUR CWA. THIS DRIER AIRMASS WILL LEAD
TO BELOW NORMAL MORNING LOWS ACROSS THE NORTH THROUGH THE END OF THE
WEEK. WARMER THAN NORMAL AFTERNOON HIGHS WILL CONTINUE HOWEVER THE
GFS MOS WAS AMONG THE HIGHEST ENSEMBLE MEMBER AND HAVE LEANED TOWARD
ENSEMBLE MEAN HIGHS THURSDAY THROUGH THE END OF THE WEEK. MAINLY
AFTERNOON AND EARLY EVENING RAIN CHANCES WILL BE CARRIED SOUTH OF
INTERSTATE 20 WEDNESDAY WHILE WL LEAVE OUT MENTION NORTH OF
INTERSTATE 20. VERY LITTLE CHANGE IN SENSIBLE WEATHER IS EXPECTED
OVER OUR AREA THURSDAY BUT A SECOND STRONGER SURFACE HIGH WILL DROP
OUT OF THE NORTHERN PLAINS ACROSS THE GREAT LAKES REGION THURSDAY
NIGHT AND THEN TO THE MID ATLANTIC SEABOARD FRIDAY. THIS WILL
REINFORCE THE DRY NORTH TO NORTHEAST FLOW ACROSS OUR REGION AND
NUDGE THE STALLED FRONTAL BOUNDARY JUST SOUTH OF HIGHWAY 84. DRY
CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE NORTHERN TWO THIRDS
OF OUR CWA BUT MODEL CONSENSUS SUGGESTS CARRYING LOW POPS ACROSS THE
HIGHWAY 84 CORRIDOR FRIDAY AND SATURDAY. THE LARGE MID LEVEL RIDGE
WILL BREAK DOWN SUNDAY INTO MONDAY WHILE WEAK SURFACE RIDGING
BECOMES ORIENTED ALONG THE GULF COAST. DEEPER MO

&&

.AVIATION...
SHOWERS AND THUNDERSTORMS ARE AFFECTING THE GLH-GWO-CBM/GTR CORRIDOR
THIS MORNING. THIS ACTIVITY WILL DIMINISH BY EARLY AFTERNOON...WITH
ISOLATED AFTERNOON STORMS POSSIBLE NEAR TAF SITES THIS AFTERNOON AND
EVENING. OTHERWISE...MORNING MVFR CATEGORIES WILL BE POSSIBLE AGAIN
EARLY TUESDAY MORNING...ESPECIALLY IN AREAS THAT RECEIVE RAINFALL.

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.

&&

$$






AREA FORECAST DISCUSSION

NWS BISMARCK ND

 1014 AM CDT MON SEP 2 2013

.UPDATE...
ISSUED AT 1014 AM CDT MON SEP 2 2013

NO SIGNIFICANT CHANGES WITH THIS UPDATE AS THE INHERITED FORECAST
IS ON TRACK...WITH ALL FOG BURNED OFF ACROSS WESTERN AND CENTRAL
NORTH DAKOTA.

UPDATE ISSUED AT 645 AM CDT MON SEP 2 2013

PATCHY FOG HAS DEVELOPED FROM PARTS OF THE JAMES RIVER VALLEY
NORTH AND WEST TOWARDS THE TIOGA AREA. THE HRRR SHOWED THIS TO
SOME DEGREE...AND HAVE ADDED A MENTION OF PATCHY FOG IN THE GRIDS
TO COVER THE LOWER VISIBILITIES. WILL CARRY THE FOG THROUGH 14Z
WHICH IS CLOSE TO THE TIMING FROM THE HRRR. MADE SMALL ADJUSTMENTS
TO TEMPERATURES AND DEWPOINTS TO REFLECT CURRENT
CONDITIONS...OTHERWISE THE FORECAST LOOKS ON TRACK.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT MON SEP 2 2013

TRANQUIL WEATHER WILL HIGHLIGHT THE SHORT TERM FORECAST.

CURRENTLY...SURFACE HIGH PRESSURE CENTER WAS NEAR THE BORDER OF
NORTH DAKOTA/MINNESOTA/MANITOBA WITH THE HIGH AXIS EXTENDING
SOUTHWARD ACROSS THE RED RIVER VALLEY. BROAD LOW PRESSURE WAS OVER
THE LEE OF THE ROCKIES. CLEAR SKIES AND LIGHT WINDS NEAR THE SURFACE
HIGH CENTER HAS ALLOWED TEMPERATURES TO DROP INTO THE 40S OVER MUCH
OF EASTERN AND CENTRAL NORTH DAKOTA. MOST OF THE WESTERN THIRD OF
THE STATE REMAINED IN THE 50S AS OF 3 AM CDT.

SOME OF THE SHORT TERM MODELS HINTED AT LIGHT TO MODERATE FOG...OR
LOW CLOUDS...FROM NEAR BISMARCK TO WILLISTON/MINOT. ALTHOUGH
SATELLITE PICS INDICATE CLEAR SKIES...MANDAN AIRPORT WAS REPORTING
CLOUDS AT 4300 FEET. THINKING THIS IS MORE ISOLATED IN NATURE AND
WILL KEEP CLEAR SKIES IN THE FORECAST TODAY AND TONIGHT.

THE SURFACE HIGH IS FORECAST TO MOVE SOUTHEAST INTO MINNESOTA THIS
EVENING AND TO WISCONSIN/IOWA BY DAYBREAK TUESDAY MORNING. THUS
SOUTH/SOUTHEAST WINDS AT 5 TO 15 MPH SHOULD PREVAIL TODAY. AFTER
YESTERDAY`S HIGHS FROM THE UPPER 60S TO UPPER 70S/NEAR
80...TEMPERATURES SHOULD BE A TAD WARMER TODAY WITH THE COOL HIGH
PRESSURE EXITING THE AREA. LOOKING AT HIGHS FROM THE MID 70S IN THE
TURTLE MOUNTAINS TO JAMES RIVER BASIN...TO THE UPPER 80S IN THE FAR
WEST.

IN ADDITION...LOW TEMPERATURES MONDAY NIGHT WILL ALSO BE HIGHER THAN
REPORTED THIS MORNING...WITH SOUTH WINDS OF AROUND 5 TO 10 MPH
TONIGHT. LOOKING AT LOWS FROM THE LOWER 50S EASTERN PORTIONS OF
CENTRAL NORTH DAKOTA TO THE LOWER 60S WEST.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 315 AM CDT MON SEP 2 2013

THE LONG TERM WILL BEGIN WITH A LARGE RIDGE ACROSS THE
CENTRAL UNITED STATES.  THE 02.00 NAM AND GFS BOTH BRING A WAVE
THROUGH THE H5 RIDGE ON TUESDAY AND MOVE IT ACROSS WESTERN AND
SOUTHERN NORTH DAKOTA TUESDAY INTO TUESDAY NIGHT.  WILL CARRY THE
HIGHEST POPS ACROSS THE SOUTHWEST AND SOUTH...WITH LESSER CHANCES IN
THE NORTH.

THE H5 RIDGE AMPLIFIES AND DOMINATES THE WEATHER OVER THE NORTHERN
PLAINS FROM WEDNESDAY THROUGH THURSDAY NIGHT. THIS WILL BRING
MAINLY DRY WEATHER ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE
RIDGE BREAKS DOWN TOWARDS THE WEEKEND AS AN UPPER LOW APPROACHES
THE NORTHERN PLAINS FROM THE PACIFIC NORTHWEST. THE CHANCES FOR
RAIN / THUNDERSTORMS WILL INCREASE AS THE UPPER LOW APPROACHES...AND
THE LATEST ALL BLEND MODEL CONSENSUS CAPTURES THIS TREND WELL.
TEMPERATURES WILL ALSO COOL AS THE RIDGE BREAKS DOWN AND THE RAIN
CHANCES INCREASE. WILL SEE HIGHS IN THE MID 80S TO LOWER 90S ON
THURSDAY AND FRIDAY...COOL INTO THE MID 70S TO MID 80S BY SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY )
ISSUED AT 1014 AM CDT MON SEP 2 2013

VFR CONDITIONS ARE EXPECTED FOR THE UPCOMING 18 UTC TAFS WITH
SURFACE HIGH PRESSURE ACROSS EASTERN NORTH DAKOTA.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AYD
SHORT TERM...JV
LONG TERM...CK
AVIATION...AYD







AREA FORECAST DISCUSSION...UPDATED

NWS GRAND FORKS ND

 702 AM CDT MON SEP 2 2013

.UPDATE...
ISSUED AT 702 AM CDT MON SEP 2 2013

12 UTC IR SATELLITE SHOWS WESTERN FLANK OF LOW CLOUDS ALONG A
WASKISH TO FOSSTON TO DETROIT LAKES TO ALEXANDRIA LINE. AS A
RESULT...UPDATED SKY COVER TO REFLECT SLOWER MOVEMENT AND
DISSIPATION. LATEST HRRR SUGGESTS THESE CLOUDS SHOULD BEGIN TO
BREAK-UP BY LATE MORNING/EARLY AFTERNOON WITH SUNNY SKIES BY MID-
LATE AFTERNOON. REST OF THE FORECAST IN GOOD SHAPE WITH NO CHANGES
NEEDED AT THIS TIME.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 345 AM CDT MON SEP 2 2013

MAIN ISSUE WILL BE TEMPERATURES WITH NO PRECIPITATION EXPECTED
THROUGH THE PERIOD. MODELS ARE IN GOOD AGREEMENT AND WILL USE A
BLENDED SOLUTION FOR THIS FORECAST PACKAGE.

FOR TODAY...SURFACE HIGH PRESSURE WILL DOMINATE THE REGIONAL
WEATHER PATTERN. A VERY DRY AIR MASS WITH AFTERNOON CONVECTIVE
TEMPERATURES ABOVE 100 DEGREES WILL RESULT IN A CLOUDLESS DAY. THE
EXCEPTION BEING ACROSS THE FAR EASTERN FORECAST AREA WHERE THE
WESTERN FLANK OF A LOW CLOUD DECK WILL MOVE SLOWLY SOUTH AND WEST
THIS MORNING BEFORE DISSIPATING LATER THIS AFTERNOON. TEMPERATURES
TODAY WILL 5 TO 10 DEGREES WARMER THAN YESTERDAY WITH HIGHS IN THE
LOW TO MID 70S. SOUTHERLY RETURN FLOW WILL DEVELOP OVERNIGHT AS
THE SURFACE HIGH MOVES INTO WI. THIS...COMBINED WITH MODEST WARM
AIR ADVECTION WILL KEEP TEMPERATURES FROM BOTTOMING OUT AND EXPECT
TUESDAY MORNING LOWS FROM THE MID 40S TO MID 50S.

BOUNDARY LAYER TEMPERATURES RISE 5 TO 8 C BY TUESDAY AFTERNOON AS
A +18 TO +22 C 850 THERMAL RIDGE MOVES ACROSS THE FORECAST AREA.
AS A RESULT...AFTERNOON HIGHS WILL CLIMB INTO THE MID 80S. SOME
HIGH CLOUDS ARE POSSIBLE...BUT STILL EXPECT PLENTY OF SOLAR.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON SEP 2 2013

TUESDAY NIGHT INTO EARLY WEDNESDAY...A DRY COLD FRONT WILL DROP
SOUTH FROM CANADA. DO NOT ANTICIPATE ANY PRECIPITATION WITH HIGHER
MOISTURE CONFINED ABOVE 700 HPA. PRIMARY SENSIBLE WEATHER IMPACTS
WILL BE A WIND SHIFT TO THE NORTH-NORTHEAST AND DECREASING
TEMPERATURES. HIGHS WEDNESDAY WILL RANGE FROM THE LOWS 70S ALONG
THE INTERNATIONAL BORDER TO THE LOW 80S ACROSS THE SOUTHERN
VALLEY.

FOR THU THROUGH SUN NIGHT...EXPECT DRY AND WARM CONDITIONS THROUGH
SAT...WITH TEMPS WELL ABOVE NORMAL AND UPPER RIDGING OVER THE AREA.
MODELS ARE IN GOOD AGREEMENT WITH A POTENT SHORTWAVE MOVING INTO
WESTERN ND SUNDAY...AND THIS WILL BRING THE NEXT CHANCE FOR SHOWERS
AND STORMS INTO THE REGION. INSTABILITY AND MOISTURE WILL ALSO
INCREASE AHEAD OF THE SHORTWAVE...WITH PWATS LIKELY AROUND 1.5
INCHES. THEREFORE...THIS COULD BE A MORE WIDESPREAD PRECIP EVENT AND
COULD LAST INTO EARLY NEXT WEEK.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 702 AM CDT MON SEP 2 2013

MVFR CEILINGS AT KBJI EXPECTED TO DISSIPATE SOMETIME BETWEEN 14
AND 16 UTC. ALL OTHER TAF SITES WILL BE VFR THROUGH 12 UTC TUESDAY
WITH SUNNY/CLEAR SKIES AND LIGHT WIND.

&&

.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&

$$

UPDATE...ROGERS
SHORT TERM...ROGERS
LONG TERM...ROGERS/DK
AVIATION...ROGERS







AREA FORECAST DISCUSSION

NWS BISMARCK ND

 646 AM CDT MON SEP 2 2013

.UPDATE...
ISSUED AT 645 AM CDT MON SEP 2 2013

PATCHY FOG HAS DEVELOPED FROM PARTS OF THE JAMES RIVER VALLEY
NORTH AND WEST TOWARDS THE TIOGA AREA. THE HRRR SHOWED THIS TO
SOME DEGREE...AND HAVE ADDED A MENTION OF PATCHY FOG IN THE GRIDS
TO COVER THE LOWER VISIBILITIES. WILL CARRY THE FOG THROUGH 14Z
WHICH IS CLOSE TO THE TIMING FROM THE HRRR. MADE SMALL ADJUSTMENTS
TO TEMPERATURES AND DEWPOINTS TO REFLECT CURRENT
CONDITIONS...OTHERWISE THE FORECAST LOOKS ON TRACK.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT MON SEP 2 2013

TRANQUIL WEATHER WILL HIGHLIGHT THE SHORT TERM FORECAST.

CURRENTLY...SURFACE HIGH PRESSURE CENTER WAS NEAR THE BORDER OF
NORTH DAKOTA/MINNESOTA/MANITOBA WITH THE HIGH AXIS EXTENDING
SOUTHWARD ACROSS THE RED RIVER VALLEY. BROAD LOW PRESSURE WAS OVER
THE LEE OF THE ROCKIES. CLEAR SKIES AND LIGHT WINDS NEAR THE SURFACE
HIGH CENTER HAS ALLOWED TEMPERATURES TO DROP INTO THE 40S OVER MUCH
OF EASTERN AND CENTRAL NORTH DAKOTA. MOST OF THE WESTERN THIRD OF
THE STATE REMAINED IN THE 50S AS OF 3 AM CDT.

SOME OF THE SHORT TERM MODELS HINTED AT LIGHT TO MODERATE FOG...OR
LOW CLOUDS...FROM NEAR BISMARCK TO WILLISTON/MINOT. ALTHOUGH
SATELLITE PICS INDICATE CLEAR SKIES...MANDAN AIRPORT WAS REPORTING
CLOUDS AT 4300 FEET. THINKING THIS IS MORE ISOLATED IN NATURE AND
WILL KEEP CLEAR SKIES IN THE FORECAST TODAY AND TONIGHT.

THE SURFACE HIGH IS FORECAST TO MOVE SOUTHEAST INTO MINNESOTA THIS
EVENING AND TO WISCONSIN/IOWA BY DAYBREAK TUESDAY MORNING. THUS
SOUTH/SOUTHEAST WINDS AT 5 TO 15 MPH SHOULD PREVAIL TODAY. AFTER
YESTERDAY`S HIGHS FROM THE UPPER 60S TO UPPER 70S/NEAR
80...TEMPERATURES SHOULD BE A TAD WARMER TODAY WITH THE COOL HIGH
PRESSURE EXITING THE AREA. LOOKING AT HIGHS FROM THE MID 70S IN THE
TURTLE MOUNTAINS TO JAMES RIVER BASIN...TO THE UPPER 80S IN THE FAR
WEST.

IN ADDITION...LOW TEMPERATURES MONDAY NIGHT WILL ALSO BE HIGHER THAN
REPORTED THIS MORNING...WITH SOUTH WINDS OF AROUND 5 TO 10 MPH
TONIGHT. LOOKING AT LOWS FROM THE LOWER 50S EASTERN PORTIONS OF
CENTRAL NORTH DAKOTA TO THE LOWER 60S WEST.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 315 AM CDT MON SEP 2 2013

THE LONG TERM WILL BEGIN WITH A LARGE RIDGE ACROSS THE
CENTRAL UNITED STATES.  THE 02.00 NAM AND GFS BOTH BRING A WAVE
THROUGH THE H5 RIDGE ON TUESDAY AND MOVE IT ACROSS WESTERN AND
SOUTHERN NORTH DAKOTA TUESDAY INTO TUESDAY NIGHT.  WILL CARRY THE
HIGHEST POPS ACROSS THE SOUTHWEST AND SOUTH...WITH LESSER CHANCES IN
THE NORTH.

THE H5 RIDGE AMPLIFIES AND DOMINATES THE WEATHER OVER THE NORTHERN
PLAINS FROM WEDNESDAY THROUGH THURSDAY NIGHT. THIS WILL BRING
MAINLY DRY WEATHER ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE
RIDGE BREAKS DOWN TOWARDS THE WEEKEND AS AN UPPER LOW APPROACHES
THE NORTHERN PLAINS FROM THE PACIFIC NORTHWEST. THE CHANCES FOR
RAIN / THUNDERSTORMS WILL INCREASE AS THE UPPER LOW APPROACHES...AND
THE LATEST ALL BLEND MODEL CONSENSUS CAPTURES THIS TREND WELL.
TEMPERATURES WILL ALSO COOL AS THE RIDGE BREAKS DOWN AND THE RAIN
CHANCES INCREASE. WILL SEE HIGHS IN THE MID 80S TO LOWER 90S ON
THURSDAY AND FRIDAY...COOL INTO THE MID 70S TO MID 80S BY SUNDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 645 AM CDT MON SEP 2 2013

SURFACE HIGH PRESSURE WAS OVER THE RED RIVER VALLEY WITH BROAD LOW
PRESSURE IN THE LEE OF THE ROCKIES. VARIABLE CLOUDS AND VSBYS
REPORTED AT A FEW ISOLATED LOCALES. LIGHT WINDS AT KJMS AND LATEST
OBS SHOWED LOCALIZED FOG FORMING IN THE KJMS AREA...WITH VSBYS
RANGING FROM 1/4 MILE TO 3 MILES AND A CEILING OF 100 FEET
REPORTED. OTHER SITES REPORTING FOG INCLUDE TIOGA (BETWEEN KISN
AND KMOT) WITH 1/4 MILE VSBY. DIFFICULT TO PICK OUT ANY TREND FROM
SATELLITE PICS AS THE LOW CLOUDS/FOG ARE NOT SHOWING UP (YET).
THUS WILL PUT A TEMPO GROUP IN WITH LOWER CIGS.

SURFACE HIGH SHOULD MOVE SOUTHEAST TODAY AND TONIGHT. SOUTHERLY
SURFACE WINDS SHOULD INCREASE TO 10 TO 15 MPH TODAY...MAINLY AFT
15Z-17Z...AND EXPECT VFR FOR ALL TAF SITES AFT 14-15Z.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...CK
SHORT TERM...JV
LONG TERM...CK
AVIATION...JV







AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 641 AM CDT MON SEP 2 2013

UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 422 AM CDT MON SEP 2 2013

FORECAST CONCERNS ON CLOUD TRENDS TODAY.

UPPER TROF CONTINUES TO MOVE TO THE EAST THIS MORNING. SAT
IMAGERY SHOWING LOW CLOUDS DROPPING SOUTH THROUGH THE WESTERN
LAKES BEHIND SYSTEM. CLOUDS HAVE HAD A HARD TIME FILLING IN OVER
THE SOUTHERN CWA...ESPECIALLY IN THE EAST WHERE DOWNSLOPE
COMPONENT OF NW WINDS OPENING HOLES. SCATTERED LIGHT SHOWERS
CONTINUE OVER NORTH CENTRAL WI WITH RHI PICKING UP ANOTHER .01
LAST HOUR.

CANADIAN HIGH PRESSURE WILL CONTINUE TO MOVE SOUTHEAST INTO THE
STATE TODAY. INCREASING SUBSIDENCE AND ADVECTION OF DRIER AIR
INTO THE REGION SHOULD WORK TO ERODE THE CLOUDS THROUGH THE DAY.
DECREASING INVERSION HEIGHTS WILL ALSO LIMIT LAKE SUPERIOR CONTRIBUTION
TO THE CLOUDS AND PCPN. GEM REGIONAL AND HRRR APPEAR TO BE
HANDLING CURRENT CLOUD TRENDS AND HAVE LEANED TOWARDS THEIR
THOUGHTS OF CLEARING BY LATER AFTERNOON. WILL CONTINUE TO CARRY
SOME TRACE LIGHT SHOWERS OVER NORTH CENTRAL INTO THE LATER
MORNING. NO SIGNIFICANT CHANGE MADE TO PREVIOUS TEMP FORECAST.

SFC HIGH PRESSURE TO BE CONTROL WEATHER OVER STATE THROUGH TUE.
LOOKING FOR CLEAR SKIES AND LIGHT WINDS. HAVE TRENDED A BIT COOLER
TONIGHT IN THE TYPICAL COOLER LOCATIONS...THOUGH SHOULD SEE SIG
DIURNAL SWING FOR TUE FOR TEMPS TO RECOVER BACK TO NEAR SEASONAL
NORMS.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 422 AM CDT MON SEP 2 2013

THE UPPER LEVEL RIDGE AMPLIFYING OVER THE WESTERN CONUS IS THE
MAIN FEATURE DURING THIS PART OF THE FORECAST. SURFACE HIGH
PRESSURE OVER THE REGION AT THE START OF THE PERIOD WILL PUSH
SOUTHWARD AS A COLD FRONT MOVES THROUGH WISCONSIN MIDWEEK. ANY
UPPER LEVEL SUPPORT REMAINS FAR TO THE NORTHEAST AND THERE IS
LITTLE MOISTURE AROUND SO A DRY FRONTAL PASSAGE IS EXPECTED.
COOLER CONDITIONS BEHIND THE FRONT SHOULD NOT LAST LONG AS SURFACE
WINDS BECOME MORE SOUTHERLY AND BRING WARMER AIR BACK TO THE AREA.

ANOTHER COLD FRONT AND SOME WEAK SHORT WAVE ENERGY WILL BRING A
CHANCE FOR SHOWERS OR STORMS TO THE AREA...MAINLY EARLY NEXT WEEK.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 624 AM CDT MON SEP 2 2013

COOL NORTH-NORTHWEST FLOW ACROSS WESTERN LAKE SUPERIOR WILL
CONTINUE TO BRING ISOLD TO SCT LIGHT LAKE-EFFECT RAIN SHOWERS AND
MVFR/IFR CIGS TO MUCH OF NORTH CENTRAL THIS MORNING. THE CLOUDS
ARE MORE VARIABLE OVER NORTHEAST AND CENTRAL WISCONSIN WITH
SCATTERED TO BROKEN CIGS IN MVFR/VFR RANGE.  DAYTIME HEATING AND
THE ARRIVAL OF DRIER AIR SHOULD CAUSE CIGS TO RISE TO VFR THERE BY
LATE MORNING...FOLLOWED BY DECREASING CLOUDS LATE IN THE DAY.
CLEAR SKIES EXPECTED TONIGHT AND TUESDAY.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TE
LONG TERM......MG
AVIATION.......TE







AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 700 AM MDT MON SEP 2 2013

.UPDATE...
ISSUED AT 649 AM MDT MON SEP 2 2013

MADE MINOR CHANGES TO POP FORECAST TODAY. A FEW SHOWERS HAVE
POPPED UP OVER NORTHERN CARBON COUNTY THIS MORNING ALONG AN
ELEVATED WARM FRONT. THIS FRONT IS PROJECTED TO MOVE NORTHEASTWARD
TODAY. MODELS PLACE THE FRONT OVER CONVERSE COUNTY LATE THIS
MORNING AND NEAR THE SOUTH DAKOTA/WYOMING BORDER MID AFTERNOON.
NOT SURE IS CONVECTION WILL BE SUSTAINED ALONG THE BOUNDARY.
USUALLY ELEVATED CONVECTION WILL SUBSIDE WITHIN A FEW HOURS AFTER
SUNRISE BUT IN CASE IT DOES NOT...ADDED LOW END POPS TO WESTERN
AND NORTHERN PORTIONS OF THE FORECAST AREA THIS MORNING. UNSTABLE
AIR WITH THIS BOUNDARY LENDS SOME CREDENCE TO THE NAM PRODUCING
QPF INTO THE NORTHERN NEBRASKA PANHANDLE THIS AFTERNOON. ALSO OF
NOTE IS THE 08Z HRRR MODEL RUN KICKS OUT PRECIPITATION OVER THE
SOUTHERN PANHANDLE THIS AFTERNOON. AT ANY RATE IT IS LOOKING LIKE
THERE IS AT LEAST SOME POTENTIAL FOR STORMS OVER THE PANHANDLE
LATER TODAY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 440 AM MDT MON SEP 2 2013

WILL START OFF THIS MORNING UNDER CLEAR SKIES IN THE EAST AND
PARTLY CLOUDY TO THE WEST. CLOUD COVER TO INCREASE BY THIS
AFTERNOON WITH A FEW SHOWERS AND THUNDERSTORM TO DEVELOP. THE MAIN
QUESTION IS COVERAGE AND LOCATION OF THUNDERSTORM ACTIVITY. BEST
CHANCES SHOULD BE IN THE WEST WHERE AS SHORTWAVE SHORTWAVE MOVES
OVER THAT AREA. THE WAVE IS CURRENTLY OVER CENTRAL UTAH MOVING
NORTHWARD. THE MAIN QUESTION FOR CONVECTION TODAY IS THE TRACK THE
WAVE WILL TAKE. MODELS GENERALLY TRACKING THE WAVE INTO NE
WYOMING AND THEN INTO WRN SOUTH DAKOTA BUT THE NAM IS SLIGHTLY
FARTHER SOUTH AND TRIES TO BREAK OUT CONVECTION INTO THE NORTHERN
PANHANDLE LATE THIS AFTERNOON. DID ADD SLIGHT CHANCE POPS TO THE
PANHANDLE BUT CONFIDENCE IS NOT HIGH.

THERE WILL BE NO SHORTAGE OF HEATING IN THE EAST AS SUNNY SKIES
WILL ALLOW FOR MAX HEATING...SO ASSUMING MAX HEATING AND SOME
UPPER LEVEL SUPPORT...A THUNDERSTORM OR TWO IS NOT COMPLETELY OUT
OF THE QUESTION. ALSO THE MODELS ARE SHOWING DUE POINTS IN THE
LOWER 50S FOR THE PANHANDLE THIS AFTERNOON. BASED ON 15 TO 20 KT
800 MB WINDS AND 60 TO 70 DEGREE DEW POINTS CURRENTLY OVER
KANSAS...WOULD NOT BE SURPRISED TO SEE DEW POINTS APPROACHING 60
DEGREES IN THE PANHANDLE BY LATE THIS AFTERNOON. THIS COULD ALSO
LEAD TO A GREATER CHANCE FOR THUNDERSTORMS LATE THIS AFTERNOON AND
EVENING AND WOULD INCREASE SURFACE BASED CAPE VALUES ABOVE THE
500 J/KG THE MODELS ARE SHOWING. EITHER WAY THE SHEAR IS ON THE
WEAK SIDE TODAY SO SEVERE THUNDERSTORM POTENTIAL IS MINIMAL AT
BEST.

TEMPERATURES WILL REBOUND TODAY AS THE UPPER LEVEL RIDGE
REESTABLISHES ITSELF OVER THE ROCKIES. TEMPERATURES TODAY WILL
GENERALLY BE 5 TO 10 DEGREES WARMER THAN YESTERDAY ACROSS THE
PLAINS WITH 90S FOR HIGHS. FARTHER WEST TEMPERATURES WILL MAINLY
BE IN THE 80S OUTSIDE OF THE MOUNTAINS. THE HEAT WILL CONTINUE
TUESDAY AND COULD BE THE WARMEST DAY OF THE WEEK FOR MANY
LOCATIONS. MAY SEE A FEW RECORDS BROKEN AS DRY WEST TO NORTHWEST
DOWN SLOPE FLOW SETS UP IN THE WAVE OF THE DEPARTING SHORTWAVE.
COULD SEE A FEW LOCATIONS IN THE PANHANDLE TOUCH 100 DEGREES.
SLIGHTLY COOLER WEDNESDAY ACROSS THE PLAINS BUT STILL LOOKING AT
WIDESPREAD 80S AND 90S FOR HIGHS. CHANCES FOR PRECIPITATION
TUESDAY AND WEDNESDAY WILL BE MINIMAL WITH CHANCES FOR MEASURABLE
PRECIPITATION MAINLY CONFINED TO THE MOUNTAINS.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 440 AM MDT MON SEP 2 2013

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH
LATE IN THE WEEK...ALTHOUGH WILL BEGIN TO SHIFT EAST AND GIVE WAY
TO SHORTWAVE TROUGHING OVER THE ROCKIES THROUGH THE WEEKEND.
EXPECTING VERY WARM TEMPS ACROSS THE CWA...WITH MARGINAL CHANCES
FOR AFTERNOON SHOWERS AND THUNDERSTORMS. THE BEST CHANCES WILL BE
FOR THE MOUNTAINS AND NEARBY LOWER ELEVATIONS IN THIS FLOW
PATTERN. LEESIDE SFC TROUGH DEVELOPMENT ON THURSDAY WILL MOVE
EASTWARD AS A WARM FRONT ON FRIDAY. THIS COULD FOCUS MORE SHOWER
ACTIVITY FURTHER EAST IN THE LATE AFTERNOON...BUT RIGHT NOW THE
ENVIRONMENT DOES NOT LOOK THAT GREAT FOR MAINTENANCE OF
THUNDERSTORMS WITH LOW BULK SHEAR VALUES PROGGED. A COOL FRONT
LOOKS TO MAKE ITS WAY SOUTH ACROSS THE FORECAST AREA SATURDAY WITH
BLUSTERY NORTHERLY WINDS IN ITS WAKE...TURNING NORTHEAST BY THE
EVENING. TEMPS WILL BE A FEW DEGREES COOLER BEHIND THE FRONT AS
WELL FOR SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 0615 AM MDT MON SEP 2 2013

VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD WITH THE MAIN
CONCERN FOR TODAYS CONVECTION GUSTY WINDS FROM THESE HIGH BASED
STORMS. BREEZY SOUTHERLY WINDS WILL PREVAIL THROUGH THE EARLY
EVENING AT MOST PLACES...AND WILL DIMINISH THROUGH THE OVERNIGHT
PERIOD. THE EXCEPTION WILL BE IN THE PANHANDLE WHERE SOUTH WINDS
THIS EVENING WILL REMAIN ON THE GUSTY SIDE THROUGH THE EARLY
MORNING HOURS. THUNDERSTORMS THAT ROLL ACROSS THE TERMINALS TODAY
WILL BRING BRIEF MVFR CONDITIONS AND GUSTY ERRATIC WINDS.

.FIRE WEATHER...
ISSUED AT 349 AM MDT MON SEP 2 2013

UPPER LEVEL RIDGE WILL CONTINUE TO BE THE MAIN DRIVER OF WEATHER
CONDITIONS THIS WEEK. HOT DRY CONDITIONS WILL BE THE NORM WITH ONLY
SLIGHT CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. UPPER LEVEL
RIDGE WILL MAKE FOR LIGHT WINDS THROUGH MOST OF THIS WEEK SO NOT
EXPECTING CRITICAL FIRE WEATHER CONDITIONS. IT WILL BE A BIT
BREEZY OVER SOUTHEAST WYOMING TUESDAY AFTERNOON WITH HUMIDITY VALUES
DIPPING INTO THE 15 TO 25 PERCENT RANGE.


&&

.FIRE WEATHER...
ISSUED AT 349 AM MDT MON SEP 2 2013

UPPER LEVEL RIDGE WILL CONTINUE TO BE THE MAIN DRIVER OF WEATHER
CONDITIONS THIS WEEK. HOT DRY CONDITIONS WILL BE THE NORM WITH ONLY
SLIGHT CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. UPPER LEVEL
RIDGE WILL MAKE FOR LIGHT WINDS THROUGH MOST OF THIS WEEK SO NOT
EXPECTING CRITICAL FIRE WEATHER CONDITIONS. IT WILL BE A BIT
BREEZY OVER SOUTHEAST WYOMING TUESDAY AFTERNOON WITH HUMIDITY VALUES
DIPPING INTO THE 15 TO 25 PERCENT RANGE.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...LIEBL
SHORT TERM...LIEBL
LONG TERM...RJM
AVIATION...RJM
FIRE WEATHER...LIEBL








AREA FORECAST DISCUSSION

NWS TUCSON AZ

 245 PM MST MON SEP 2 2013

.SYNOPSIS...SUFFICIENT MOISTURE WILL KEEP ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THIS WEEK.
AFTERNOON HIGH TEMPERATURES WILL REMAIN SEVERAL DEGREES ABOVE
NORMAL.

&&

.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 35-50 DBZ ECHOES ON THE
GALIURO/PINALENO MOUNTAINS IN SWRN GRAHAM COUNTY AND JUST WEST OF
THE CHIRICAHUA MOUNTAINS IN FAR ERN COCHISE COUNTY AT 2140Z. THE
REST OF SE AZ WAS VOID OF PRECIP ECHOES AT THIS TIME. THE THICKER
CLOUDS ASSOCIATED WITH REMNANT MCV WERE MOVING NWWD ACROSS PINAL/ERN
PIMA COUNTIES...WITH OTHER CUMULOFORM CLOUDS ON MOST OF THE
MOUNTAINS OF GREENLEE/GRAHAM/COCHISE COUNTIES.

GIVEN THE PASSAGE OF THE MCV EARLIER TODAY...FORECAST CONFIDENCE IS
FAIRLY LOW THRU THIS EVENING. GIVEN THE RECENT CELL DEVELOPMENT
ADJACENT THE GALIURO/PINALENO/CHIRICAHUA MOUNTAINS...APPEARS THAT
SEVERAL RUC HRRR SOLUTIONS MAY HAVE THE BEST HANDLE REGARDING
CONVECTIVE DEVELOPMENT AND PROGRESSION INTO THIS EVENING.

THUS...DURING THE NEXT 1-2 HOURS OR SO...SHOWERS/TSTMS SHOULD
DEVELOP ACROSS THE HIGHER TERRAIN OF GREENLEE/GRAHAM/COCHISE
COUNTIES. SHOWERS/TSTMS MAY THEN MOVE AS FAR WEST AS THE TUCSON
METRO AREA BY AROUND SUNSET. MOSTLY DRY CONDITIONS SHOULD OCCUR
ACROSS WRN/CENTRAL PIMA COUNTY INTO THIS EVENING. HAVE OPTED FOR DRY
CONDITIONS LATE TONIGHT EXCEPT FOR A SLIGHT CHANCE OF SHOWERS/TSTMS
MAINLY NEAR THE NEW MEXICO BORDER.

TUE-TUE NIGHT...
HAVE MAINTAINED SCATTERED SHOWERS/TSTMS ACROSS MUCH OF SE AZ TUE
AFTERNOON/EVENING. HOWEVER...HAVE NOTED THAT THE GFS/ECMWF HAVE
TRENDED FURTHER SOUTH WITH THE WESTWARD PROGRESSION OF AN INVERTED
TROUGH VERSUS PREVIOUS SOLUTIONS. THUS...THE ACTUAL COVERAGE MAY BE
LESS THAN THE CURRENT OFFICIAL FORECAST DEPICTS.

WED-MON...
UPPER HIGH IS PROGGED TO BE GENERALLY CENTERED OVER THE CENTRAL
CONUS PLAINS. MEANWHILE...A DEEP UPPER LOW CENTERED INITIALLY NEAR
THE PACIFIC NW COAST WILL EVENTUALLY WEAKEN AND MOVE EWD ACROSS THE
NRN ROCKIES BY EARLY NEXT WEEK. MOISTURE APPEARS TO BE SUFFICIENT TO
MAINTAIN ISOLATED-SCATTERED AFTERNOON AND EVENING SHOWERS/TSTMS.

HIGH TEMPS THIS WEEK ARE FORECAST TO AVERAGE ABOUT 2-5 DEGS F OR SO
ABOVE CLIMO.

&&

.AVIATION...ISOLD-SCT TSRA/SHRA THRU THIS EVENING AND AGAIN TUESDAY
AFTERNOON. THE BULK OF THIS ACTIVITY SHOULD OCCUR EAST OF KTUS TO
THE NEW MEXICO BORDER. DRY CONDITIONS ARE EXPECTED ACROSS MUCH OF
THE AREA LATE TONIGHT AND TUESDAY MORNING. OTHERWISE...AFTERNOON AND
EVENING CLOUD DECKS WILL BE NEAR 7-11K FT AGL THEN MOSTLY ABOVE 12K
FT AGL LATE TONIGHT AND EARLY TUESDAY MORNING. SURFACE WIND WILL
GENERALLY BE LESS THAN 10 KTS THRU TUESDAY AFTERNOON OR 04/00Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT ISOLATED TO SCATTERED AFTERNOON AND EVENING
THUNDERSTORMS INTO NEXT WEEKEND. STRONG...GUSTY AND ERRATIC WINDS
WILL OCCUR WITH THE STRONGER THUNDERSTORMS. OTHERWISE...HIGH
PRESSURE CENTERED NORTH AND EAST OF THE AREA WILL PROVIDE A SURFACE
WIND FLOW REGIME GENERALLY FROM THE EAST TO SOUTHEAST DURING MUCH OF
THIS WEEK. DAYTIME TEMPERATURES WILL REMAIN ABOVE NORMAL THIS WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

BF






AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 150 PM MST MON SEP 2 2013

.UPDATE...TO AVIATION AND FIRE WEATHER DISCUSSIONS...

.SYNOPSIS...
LINGERING MONSOON MOISTURE...ALONG WITH WARMER AFTERNOONS...AND A
FEW HARD TO TIME WEATHER DISTURBANCES WILL RESULT IN A SLIGHT CHANCE
OF AFTERNOON AND EVENING THUNDERSTORMS REGION WIDE THIS WEEK.

&&

.DISCUSSION...
A VORT MAX...CURRENTLY CENTERED NEAR BLYTHE HELPED TRIGGER
CONSIDERABLE STORM ACTIVITY OVER SONORA LAST NIGHT WHICH LEAD TO AN
MCV NEAR THE MEXICO BORDER. THIS FEATURE KEPT CONVECTION GOING AND
MOVED INTO PIMA COUNTY. GUSTY WINDS FROM THOSE STORMS HAVE MADE IT
INTO THE PHOENIX AREA ALREADY. SURPRISINGLY DUSTY GIVEN THE
UNDERWHELMING STRENGTH OF THE WINDS AND LACK OF VIS REDUCTION AT
CGZ. DUST WILL IMPROVE SHORTLY. MADE SOME UPDATES TO THE FORECASTS
EARLIER TO INTRODUCE SLIGHT CHANCE POPS OVER PORTIONS OF
YUMA...SOUTHWEST MARICOPA...AND WESTERN PINAL COUNTIES FOR THIS
MORNING. ALSO NUDGED UP POPS A BIT FOR THIS AFTERNOON...INCLUDING
LOW END SLIGHT CHANCES FOR THE PHOENIX AREA. STORM ACTIVITY THAT HAD
BE CLOSER TO THE CENTER OF THE MCV HAVE WEAKENED QUITE A BIT BUT NEW
STORMS HAVE DEVELOPED ON THE WESTERN PERIPHERY OF IT AS OF THIS
WRITING. HRRR MODEL REFLECTS THIS FEATURE BUT HAS BEEN INDICATING
SOUTHWEST MARICOPA COUNTY GETTING MORE INVOLVED THAN IT HAS. IT GOES
ON TO DEVELOP A GOOD DEAL OF STORMS OVER SOUTHWEST ARIZONA AS WELL
AS STORMS ALONG A THE SPINE OF HIGHEST TERRAIN IN OUR ZONE 24.
NEITHER OF THE 06Z RUNS OF THE NMM6KM NOR OUR LOCAL WRF DEPICTED ANY
OF THE CONVECTION THIS MORNING. 12Z SOUNDINGS INDICATE GOOD MIXED
LAYER CAPE...ESPECIALLY TWC. HOWEVER...THIS VERY FEATURE MAY WIND UP
INHIBITING STORM COVERAGE OVER THE SOUTH-CENTRAL ARIZONA DESERTS
LATER TODAY DUE TO BOUNDARY LAYER STABILIZATION THAT OCCURRED
UPSTREAM FROM THE RAIN COOLED AIR. FOR SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA...THE AFOREMENTIONED DISTURBANCE WHICH
INITIATED THINGS TODAY HAS NOT HAD MUCH IMPACT SO FAR.
HOWEVER...THERE ARE MORE DISTURBANCES TO COME ASSOCIATED WITH THE
REMNANTS OF KIKO WHICH MAY PROVIDE A LITTLE DYNAMICAL NUDGE TO AID
IN STORM ACTIVITY. SO ABOVE NORMAL POPS CONTINUE THERE. WILL
CONTINUE TO EVALUATE. MORE LATER.
&&

.PREVIOUS DISCUSSION...ISSUED AT 300 AM...
TODAY AND TUESDAY...
MOST OF THE CONVECTIVE POTENTIAL MONDAY WILL LIKELY BE FOCUSED OVER
PORTIONS OF SOUTHEAST CA AND THE COLORADO RIVER VALLEY...AS
ACCELERATING UPPER LEVEL SOUTHERLY WINDS FLOW INTO AN INCREASING
JETMAX OVER EASTERN NEVADA. IN OTHER WORDS...ENTRANCE REGION
DYNAMICS IS EXPECTED OVER SOUTHEAST CA. THE HIGHEST PRECIP
PROBABILITIES WILL BE IN THAT REGION. DITTO ON TUESDAY.  THE
REMAINDER OF THE FORECAST AREA...SOUTHWEST AND SOUTH CENTRAL AZ WILL
BE DEVOID OF ANY UPPER LEVEL SUPPORT...THEREFORE A SLIGHT CHANCE OF
HEAT OF THE DAY SHOWERS AND THUNDERSTORMS WILL EXIST...WITH SOMEWHAT
HIGHER PROBABILITIES IN THE MOUNTAINS OF SOUTHERN GILA COUNTY.

ALSO ON TUESDAY...AN INVERTED TROF IS FORECAST TO MOVE INTO
SOUTHEAST AZ FROM WEST TEXAS BY EVENING. THEREFORE WE HAVE DECIDED
TO GO WITH A HIGHER PRECIP PROBABILITY OVER PORTIONS OF SOUTH
CENTRAL AZ...INCLUDING THE DESERTS AROUND PHOENIX AND CASA GRANDE.
MODELS FORECAST THE INVERTED TROF MAY ALSO SUPPORT A FEW NOCTURNAL
SHOWERS AND THUNDERSTORMS OVER SOUTH CENTRAL AZ INTO WEDNESDAY
MORNING.

WEDNESDAY THROUGH SUNDAY...
IN THE AFTER-MATH OF THE ABOVE MENTIONED INVERTED TROF TUESDAY
AFTERNOON AND EVENING...DRIER AIR IS FORECAST TO SPREAD INTO EASTERN
AZ.  BUT WITH WARMER AFTERNOONS...INSTABILITY TSTMS ARE STILL
POSSIBLE IN THE MOUNTAINS. A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS ARE ALSO FORECAST ON THE DESERTS AS MODELS HINT THAT A
FEW WEAK INVERTED TROFS WILL FLOW INTO THE REGION FROM MEXICO UNDER
SOUTHERLY FLOW ALOFT. THESE FEATURES WILL BE HARD TO TIME.

&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...

AFTER THIS AFTERNOON/S THUNDERSTORM ACTIVITY THAT IS NOW MOVING
THROUGH THE GREATER PHX AREA...WHILE WILL LIKE PRODUCE GUSTY WINDS
AND BRIEF HEAVY DOWNPOURS...THERE IS STILL A CHANCE THAT MORE
THUNDERSTORMS...OR DUST STORMS COULD AFFECT THE TERMINALS THROUGH
THE EVENING HOURS...AND WILL HAVE VCTS IN THE TAFS TO REFLECT THIS
POSSIBILITY. OTHERWISE...SCT TO BKN MID-HIGH LEVEL CIGS WILL BE THE
RULE THROUGH THE TAF PERIOD. WINDS TO REMAIN MAINLY ON THE LIGHT
SIDE...OUTSIDE OF THUNDERSTORMS.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
KEEPING VCSH IN BOTH THE KBLH AND KIPL TAFS THROUGH THE EVENING
HOURS TO REFLECT THE CONTINUED DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS ACROSS THE DESERTS OF SW AZ AND SE CA. OTHERWISE...SCT
TO BKN MID-HIGH LEVEL CIGS WILL BE THE RULE THROUGH THE TAF PERIOD.
WINDS TO REMAIN MAINLY ON THE LIGHT SIDE...AND FOLLOW THE USUAL
DIURNAL TRENDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
DRIER AIR ACROSS THE REGION WILL LIKELY KEEP MOST THUNDERSTORM
ACTIVITY CONFINED TO THE HIGHER TERRAIN EAST OF PHOENIX...WITH JUST
SOME ISOLATED STORMS MOVING INTO THE DESERTS EACH AFTERNOON AND
EVENING. HUMIDITIES EACH AFTERNOON WILL DROP INTO THE 20 TO 30
PERCENT RANGE ACROSS THE LOWER DESERTS...WITH GOOD OVERNIGHT
RECOVERY ANTICIPATED. OUTSIDE OF THUNDERSTORMS...WINDS WILL FAVOR
THE TYPICAL DIURNAL UPSLOPE/DOWNVALLEY PATTERNS.

&&



.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...PERCHA
FIRE WEATHER...PERCHA






AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 1015 AM MST MON SEP 2 2013

.UPDATE...TO AVIATION DISCUSSION...

.SYNOPSIS...
LINGERING MONSOON MOISTURE...ALONG WITH WARMER AFTERNOONS...AND A
FEW HARD TO TIME WEATHER DISTURBANCES WILL RESULT IN A SLIGHT CHANCE
OF AFTERNOON AND EVENING THUNDERSTORMS REGION WIDE THIS WEEK.

&&

.DISCUSSION...
A VORT MAX...CURRENTLY CENTERED NEAR BLYTHE HELPED TRIGGER
CONSIDERABLE STORM ACTIVITY OVER SONORA LAST NIGHT WHICH LEAD TO AN
MCV NEAR THE MEXICO BORDER. THIS FEATURE KEPT CONVECTION GOING AND
MOVED INTO PIMA COUNTY. GUSTY WINDS FROM THOSE STORMS HAVE MADE IT
INTO THE PHOENIX AREA ALREADY. SURPRISINGLY DUSTY GIVEN THE
UNDERWHELMING STRENGTH OF THE WINDS AND LACK OF VIS REDUCTION AT
CGZ. DUST WILL IMPROVE SHORTLY. MADE SOME UPDATES TO THE FORECASTS
EARLIER TO INTRODUCE SLIGHT CHANCE POPS OVER PORTIONS OF
YUMA...SOUTHWEST MARICOPA...AND WESTERN PINAL COUNTIES FOR THIS
MORNING. ALSO NUDGED UP POPS A BIT FOR THIS AFTERNOON...INCLUDING
LOW END SLIGHT CHANCES FOR THE PHOENIX AREA. STORM ACTIVITY THAT HAD
BE CLOSER TO THE CENTER OF THE MCV HAVE WEAKENED QUITE A BIT BUT NEW
STORMS HAVE DEVELOPED ON THE WESTERN PERIPHERY OF IT AS OF THIS
WRITING. HRRR MODEL REFLECTS THIS FEATURE BUT HAS BEEN INDICATING
SOUTHWEST MARICOPA COUNTY GETTING MORE INVOLVED THAN IT HAS. IT GOES
ON TO DEVELOP A GOOD DEAL OF STORMS OVER SOUTHWEST ARIZONA AS WELL
AS STORMS ALONG A THE SPINE OF HIGHEST TERRAIN IN OUR ZONE 24.
NEITHER OF THE 06Z RUNS OF THE NMM6KM NOR OUR LOCAL WRF DEPICTED ANY
OF THE CONVECTION THIS MORNING. 12Z SOUNDINGS INDICATE GOOD MIXED
LAYER CAPE...ESPECIALLY TWC. HOWEVER...THIS VERY FEATURE MAY WIND UP
INHIBITING STORM COVERAGE OVER THE SOUTH-CENTRAL ARIZONA DESERTS
LATER TODAY DUE TO BOUNDARY LAYER STABILIZATION THAT OCCURRED
UPSTREAM FROM THE RAIN COOLED AIR. FOR SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA...THE AFOREMENTIONED DISTURBANCE WHICH
INITIATED THINGS TODAY HAS NOT HAD MUCH IMPACT SO FAR.
HOWEVER...THERE ARE MORE DISTURBANCES TO COME ASSOCIATED WITH THE
REMNANTS OF KIKO WHICH MAY PROVIDE A LITTLE DYNAMICAL NUDGE TO AID
IN STORM ACTIVITY. SO ABOVE NORMAL POPS CONTINUE THERE. WILL
CONTINUE TO EVALUATE. MORE LATER.
&&

.PREVIOUS DISCUSSION...ISSUED AT 300 AM...
TODAY AND TUESDAY...
MOST OF THE CONVECTIVE POTENTIAL MONDAY WILL LIKELY BE FOCUSED OVER
PORTIONS OF SOUTHEAST CA AND THE COLORADO RIVER VALLEY...AS
ACCELERATING UPPER LEVEL SOUTHERLY WINDS FLOW INTO AN INCREASING
JETMAX OVER EASTERN NEVADA. IN OTHER WORDS...ENTRANCE REGION
DYNAMICS IS EXPECTED OVER SOUTHEAST CA. THE HIGHEST PRECIP
PROBABILITIES WILL BE IN THAT REGION. DITTO ON TUESDAY.  THE
REMAINDER OF THE FORECAST AREA...SOUTHWEST AND SOUTH CENTRAL AZ WILL
BE DEVOID OF ANY UPPER LEVEL SUPPORT...THEREFORE A SLIGHT CHANCE OF
HEAT OF THE DAY SHOWERS AND THUNDERSTORMS WILL EXIST...WITH SOMEWHAT
HIGHER PROBABILITIES IN THE MOUNTAINS OF SOUTHERN GILA COUNTY.

ALSO ON TUESDAY...AN INVERTED TROF IS FORECAST TO MOVE INTO
SOUTHEAST AZ FROM WEST TEXAS BY EVENING. THEREFORE WE HAVE DECIDED
TO GO WITH A HIGHER PRECIP PROBABILITY OVER PORTIONS OF SOUTH
CENTRAL AZ...INCLUDING THE DESERTS AROUND PHOENIX AND CASA GRANDE.
MODELS FORECAST THE INVERTED TROF MAY ALSO SUPPORT A FEW NOCTURNAL
SHOWERS AND THUNDERSTORMS OVER SOUTH CENTRAL AZ INTO WEDNESDAY
MORNING.

WEDNESDAY THROUGH SUNDAY...
IN THE AFTER-MATH OF THE ABOVE MENTIONED INVERTED TROF TUESDAY
AFTERNOON AND EVENING...DRIER AIR IS FORECAST TO SPREAD INTO EASTERN
AZ.  BUT WITH WARMER AFTERNOONS...INSTABILITY TSTMS ARE STILL
POSSIBLE IN THE MOUNTAINS. A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS ARE ALSO FORECAST ON THE DESERTS AS MODELS HINT THAT A
FEW WEAK INVERTED TROFS WILL FLOW INTO THE REGION FROM MEXICO UNDER
SOUTHERLY FLOW ALOFT. THESE FEATURES WILL BE HARD TO TIME.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
BLOWING DUST GENERATED BY OUTFLOWS FROM THUNDERSTORMS THAT
DEVELOPED EARLIER THIS MORNING OVER FAR SOUTHERN ARIZONA IS NOW
MOVING THROUGH THE GREATER PHOENIX AREA...REDUCING VISIBILITIES TO
AS LOW AS 1 MILE AT SKY HARBOR. THIS DUST IS EXPECTED TO CONTINUE TO
MOVE NORTHWARD AND AFFECT KSDL OVER THE NEXT 1/2 HOUR OR SO AS WELL.
VISIBILITIES ARE EXPECTED TO BEGIN TO IMPROVE BY 18Z AS THE WINDS
DIMINISH. THERE IS A SLIGHT CHANCE THAT THUNDERSTORMS...OR DUST
STORMS COULD AFFECT THE TERMINALS LATE THIS AFTERNOON OR EVENING AS
WELL...BUT CONFIDENCE IS TOO LOW TO INCLUDE THEM IN THE TAFS...AT
THIS TIME.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY SCT CLOUDS AOA 25KFT WILL LINGER THROUGH THE MORNING WITH
LIGHT WINDS CONTINUING. BY AFTERNOON...STORM DEVELOPMENT OVER THE
HIGHER TERRAIN IS EXPECTED WITH MODERATE CONFIDENCE OF STORMS
DEVELOPING ACROSS OR DOWN INTO THE DESERTS...INCLUDING NEAR KIPL AND
KBLH. INTRODUCED VCSH FOR THE AFTERNOON WITH WEST TO SW WINDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AIR WILL MOVE INTO THE REGION AS THE WEEK PROGRESSES. WHILE
AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH
AFTERNOON...STORMS SHOULD BECOME INCREASINGLY CONFINED TO THE HIGHER
TERRAIN EAST OF PHOENIX...WITH LITTLE TO NO ACTIVITY ACROSS THE
DESERTS. HUMIDITIES EACH AFTERNOON WILL DROP INTO THE 15 TO 20
PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY ANTICIPATED. WEDNESDAY
AND THURSDAY...INCREASED EAST TO SOUTHEASTERLY FLOW IS ANTICIPATED
ACROSS SOUTHERN AND SOUTH CENTRAL ARIZONA...OTHERWISE WINDS WILL
FAVOR THE TYPICAL UPSLOPE/DOWNVALLEY PATTERNS WITH NO MAJOR WIND
EVENTS ANTICIPATED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...PERCHA/NOLTE
FIRE WEATHER...LEINS/NOLTE











AREA FORECAST DISCUSSION

NWS TUCSON AZ

 1000 AM MST MON SEP 2 2013

.SYNOPSIS...SUFFICIENT MOISTURE WILL KEEP ISOLATED TO SCATTERED
SHOWERS AND THUNDERSTORMS ACROSS SOUTHEAST ARIZONA THIS WEEK.
AFTERNOON HIGH TEMPERATURES WILL REMAIN SEVERAL DEGREES ABOVE
NORMAL.

&&

.DISCUSSION...KEMX WSR-88D DETECTED SCATTERED TO NUMEROUS 30-50 DBZ
ECHOES ACROSS MUCH OF WRN PIMA COUNTY...THE TOHONO O`ODHAM NATION...
AND SANTA CRUZ COUNTY AT 1655Z. THE REST OF SE AZ WAS VOID OF PRECIP
ECHOES AT THIS TIME. IR/VISIBLE SATELLITE IMAGERY AND RADAR IMAGERY
DEPICTED THE CYCLONIC CIRCULATION CENTER ASSOCIATED WITH THE MCS
MOVING WWD ACROSS SE AZ TO BE JUST SW OF TUCSON.

OTHERWISE...DEWPOINTS VALID 16Z RANGED FROM THE MID 50S NEAR THE NEW
MEXICO BORDER TO THE MID 60S ACROSS WRN PIMA COUNTY. THESE TEMPS
WERE ABOUT 5-10 DEGS F LOWER ACROSS ERN SECTIONS VERSUS 24 HOURS
AGO...AND THESE TEMPS ELSEWHERE WERE NEARLY IDENTICAL TO THIS TIME
SUN. SURFACE TEMPS VALID 16Z WERE ABOUT 5-10 DEGS F COOLER VERSUS 24
HOURS AGO. 02/12Z UPPER AIR PLOTS INDICATED 593 DM HIGH PRESSURE
CENTERED OVER EAST CENTRAL NEW MEXICO...AND A DEEP LOW PRESSURE
SYSTEM CENTERED JUST OFF THE PACIFIC NW COAST. A LIGHT TO MODERATE
GENERALLY SELY FLOW REGIME PREVAILED OVER SE AZ.

ONGOING MCS PRESENTS A FORECAST CHALLENGE FOR THE REST OF TODAY.
02/14Z RUC HRRR WAS TOO FAR SE AT 16Z (9 AM MST) WITH THE MCS...
WITH THE STRONGEST COMP REFL ECHOES CENTERED OVER FAR WRN SANTA CRUZ
COUNTY. MEANWHILE...THE 02/12Z UNIV OF AZ WRF-NAM WAS ALSO TOO FAR
EAST WITH THE ONGOING COMP REFL ECHOES. THE HRRR SUBSEQUENTLY
DEVELOPS ISOLATED TO PERHAPS SCATTERED SHOWERS/TSTMS MAINLY NEAR THE
MOUNTAINS OF COCHISE AND SWRN GRAHAM COUNTIES THIS AFTERNOON
FOLLOWED BY VERY LIMITED COVERAGE OF PRECIP INTO EARLY THIS EVENING.
THE WRF-NAM WAS SIMILAR TO THE RUC HRRR...EXCEPT THAT ANOTHER
CONVECTIVE COMPLEX IS DEPICTED TO OCCUR ESSENTIALLY ACROSS THE SAME
AREA WHERE THE MCS MOVED EARLIER.

AT ANY RATE...WILL LIKELY MODIFY THE GRIDDED DATA POP FIELDS FOR
THIS AFTERNOON AND THIS EVENING TO REFLECT REDUCED RAIN CHANCES FOR
THE VALLEYS. MOUNTAIN POPS OF 30-50 PERCENT SHOULD BE SUFFICIENT.
WILL LIKELY REDUCE HIGH TEMPS THIS AFTERNOON FROM TUCSON WWD AT
LEAST A FEW DEGREES.

PER COORD WITH NCEP SDM...A SPECIAL 18Z KTWC SOUNDING WILL BE
ATTEMPTED.

PLEASE REFER TO THE PREVIOUS DISCUSSION SECTION FOR ADDITIONAL
DETAIL.

&&

.PREV DISCUSSION /647 AM MST MON SEP 2 2013/...TUESDAY CONTINUES TO
LOOK LIKE THE MOST ACTIVE DAY OF THE WEEK WITH HIGHER TERRAIN STORMS
MOVING INTO THE LOWER DESERTS DUE TO 15-20 MPH MID LEVEL STEERING
FLOW. AGAIN HIGHEST PW VALUES WILL BE WEST OF TUCSON.

WEDNESDAY...ISOLATED TO SCATTERED STORMS WITH BEST CHANCES OF STORMS
BEING SOUTH AND WEST OF TUCSON.

LOW GRADE MONSOON FORECAST THURSDAY INTO THE UPCOMING WEEKEND.

ABOVE NORMAL HIGHS WILL CONTINUE THRU MUCH OF THE WEEK.

&&

.AVIATION...SCT TSRA/SHRA WEST AND SOUTH OF KTUS THRU 20Z AS A
CONVECTIVE COMPLEX MOVES WWD ACROSS SE AZ. THEREAFTER...ISOLD-SCT
TSRA/SHRA AREAWIDE INTO THIS EVENING FOLLOWED BY ISOLD -SHRA LATE
TONIGHT INTO EARLY TUESDAY MORNING. THE STRONGER TSRA WILL PRODUCE
MVFR CIGS/VSBYS AND BRIEF WIND GUSTS TO AROUND 45 KTS. SURFACE WIND
WILL GENERALLY BE LESS THAN 10 KTS THRU TUESDAY MORNING OR 03/18Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...A MOIST AIRMASS WILL LEAD TO THE DAILY CYCLE OF
ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS
THIS WEEK. STRONG...GUSTY AND ERRATIC WINDS WILL OCCUR WITH THE
STRONGER THUNDERSTORMS. OTHERWISE...HIGH PRESSURE CENTERED NORTH AND
EAST OF THE AREA WILL PROVIDE A SURFACE WIND FLOW REGIME GENERALLY
FROM THE EAST TO SOUTHEAST DURING MUCH OF THIS WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON

BF






AREA FORECAST DISCUSSION

NWS PHOENIX AZ

 950 AM MST MON SEP 2 2013

.SYNOPSIS...
LINGERING MONSOON MOISTURE...ALONG WITH WARMER AFTERNOONS...AND A
FEW HARD TO TIME WEATHER DISTURBANCES WILL RESULT IN A SLIGHT CHANCE
OF AFTERNOON AND EVENING THUNDERSTORMS REGION WIDE THIS WEEK.

&&

.DISCUSSION...
A VORT MAX...CURRENTLY CENTERED NEAR BLYTHE HELPED TRIGGER
CONSIDERABLE STORM ACTIVITY OVER SONORA LAST NIGHT WHICH LEAD TO AN
MCV NEAR THE MEXICO BORDER. THIS FEATURE KEPT CONVECTION GOING AND
MOVED INTO PIMA COUNTY. GUSTY WINDS FROM THOSE STORMS HAVE MADE IT
INTO THE PHOENIX AREA ALREADY. SURPRISINGLY DUSTY GIVEN THE
UNDERWHELMING STRENGTH OF THE WINDS AND LACK OF VIS REDUCTION AT
CGZ. DUST WILL IMPROVE SHORTLY. MADE SOME UPDATES TO THE FORECASTS
EARLIER TO INTRODUCE SLIGHT CHANCE POPS OVER PORTIONS OF
YUMA...SOUTHWEST MARICOPA...AND WESTERN PINAL COUNTIES FOR THIS
MORNING. ALSO NUDGED UP POPS A BIT FOR THIS AFTERNOON...INCLUDING
LOW END SLIGHT CHANCES FOR THE PHOENIX AREA. STORM ACTIVITY THAT HAD
BE CLOSER TO THE CENTER OF THE MCV HAVE WEAKENED QUITE A BIT BUT NEW
STORMS HAVE DEVELOPED ON THE WESTERN PERIPHERY OF IT AS OF THIS
WRITING. HRRR MODEL REFLECTS THIS FEATURE BUT HAS BEEN INDICATING
SOUTHWEST MARICOPA COUNTY GETTING MORE INVOLVED THAN IT HAS. IT GOES
ON TO DEVELOP A GOOD DEAL OF STORMS OVER SOUTHWEST ARIZONA AS WELL
AS STORMS ALONG A THE SPINE OF HIGHEST TERRAIN IN OUR ZONE 24.
NEITHER OF THE 06Z RUNS OF THE NMM6KM NOR OUR LOCAL WRF DEPICTED ANY
OF THE CONVECTION THIS MORNING. 12Z SOUNDINGS INDICATE GOOD MIXED
LAYER CAPE...ESPECIALLY TWC. HOWEVER...THIS VERY FEATURE MAY WIND UP
INHIBITING STORM COVERAGE OVER THE SOUTH-CENTRAL ARIZONA DESERTS
LATER TODAY DUE TO BOUNDARY LAYER STABILIZATION THAT OCCURRED
UPSTREAM FROM THE RAIN COOLED AIR. FOR SOUTHWEST ARIZONA AND
SOUTHEAST CALIFORNIA...THE AFOREMENTIONED DISTURBANCE WHICH
INITIATED THINGS TODAY HAS NOT HAD MUCH IMPACT SO FAR.
HOWEVER...THERE ARE MORE DISTURBANCES TO COME ASSOCIATED WITH THE
REMNANTS OF KIKO WHICH MAY PROVIDE A LITTLE DYNAMICAL NUDGE TO AID
IN STORM ACTIVITY. SO ABOVE NORMAL POPS CONTINUE THERE. WILL
CONTINUE TO EVALUATE. MORE LATER.
&&

.PREVIOUS DISCUSSION...ISSUED AT 300 AM...
TODAY AND TUESDAY...
MOST OF THE CONVECTIVE POTENTIAL MONDAY WILL LIKELY BE FOCUSED OVER
PORTIONS OF SOUTHEAST CA AND THE COLORADO RIVER VALLEY...AS
ACCELERATING UPPER LEVEL SOUTHERLY WINDS FLOW INTO AN INCREASING
JETMAX OVER EASTERN NEVADA. IN OTHER WORDS...ENTRANCE REGION
DYNAMICS IS EXPECTED OVER SOUTHEAST CA. THE HIGHEST PRECIP
PROBABILITIES WILL BE IN THAT REGION. DITTO ON TUESDAY.  THE
REMAINDER OF THE FORECAST AREA...SOUTHWEST AND SOUTH CENTRAL AZ WILL
BE DEVOID OF ANY UPPER LEVEL SUPPORT...THEREFORE A SLIGHT CHANCE OF
HEAT OF THE DAY SHOWERS AND THUNDERSTORMS WILL EXIST...WITH SOMEWHAT
HIGHER PROBABILITIES IN THE MOUNTAINS OF SOUTHERN GILA COUNTY.

ALSO ON TUESDAY...AN INVERTED TROF IS FORECAST TO MOVE INTO
SOUTHEAST AZ FROM WEST TEXAS BY EVENING. THEREFORE WE HAVE DECIDED
TO GO WITH A HIGHER PRECIP PROBABILITY OVER PORTIONS OF SOUTH
CENTRAL AZ...INCLUDING THE DESERTS AROUND PHOENIX AND CASA GRANDE.
MODELS FORECAST THE INVERTED TROF MAY ALSO SUPPORT A FEW NOCTURNAL
SHOWERS AND THUNDERSTORMS OVER SOUTH CENTRAL AZ INTO WEDNESDAY
MORNING.

WEDNESDAY THROUGH SUNDAY...
IN THE AFTER-MATH OF THE ABOVE MENTIONED INVERTED TROF TUESDAY
AFTERNOON AND EVENING...DRIER AIR IS FORECAST TO SPREAD INTO EASTERN
AZ.  BUT WITH WARMER AFTERNOONS...INSTABILITY TSTMS ARE STILL
POSSIBLE IN THE MOUNTAINS. A SLIGHT CHANCE OF AFTERNOON AND EVENING
THUNDERSTORMS ARE ALSO FORECAST ON THE DESERTS AS MODELS HINT THAT A
FEW WEAK INVERTED TROFS WILL FLOW INTO THE REGION FROM MEXICO UNDER
SOUTHERLY FLOW ALOFT. THESE FEATURES WILL BE HARD TO TIME.


&&

.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
EXPECT SCT TO BKN DEBRIS CLOUDS FROM NOCTURNAL CONVECTION ALONG THE
INTL BORDER TO DRIFT NORTHWARD THROUGH THE MORNING REMAINING AOA
20KFT. EASTERLY MORNING WINDS WILL TURN WEST THROUGH THE AFTERNOON.
AFTERNOON AND EVENING MOUNTAIN STORMS TO THE NORTH AND EAST OF
PHOENIX ARE POSSIBLE...WITH LIMITED CHANCES OF STORMS SURVIVING NEAR
THE PHOENIX AREA TERMINALS. CONFIDENCE REMAINS MOSTLY LOW FOR STORMS
AND STORM OUTFLOWS IMPACTING THE TERMINALS TONIGHT.

SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
MOSTLY SCT CLOUDS AOA 25KFT WILL LINGER THROUGH THE MORNING WITH
LIGHT WINDS CONTINUING. BY AFTERNOON...STORM DEVELOPMENT OVER THE
HIGHER TERRAIN IS EXPECTED WITH MODERATE CONFIDENCE OF STORMS
DEVELOPING ACROSS OR DOWN INTO THE DESERTS...INCLUDING NEAR KIPL AND
KBLH. INTRODUCED VCSH FOR THE AFTERNOON WITH WEST TO SW WINDS.

AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.

&&

.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRIER AIR WILL MOVE INTO THE REGION AS THE WEEK PROGRESSES. WHILE
AFTERNOON SHOWERS AND THUNDERSTORMS WILL REMAIN A POSSIBILITY EACH
AFTERNOON...STORMS SHOULD BECOME INCREASINGLY CONFINED TO THE HIGHER
TERRAIN EAST OF PHOENIX...WITH LITTLE TO NO ACTIVITY ACROSS THE
DESERTS. HUMIDITIES EACH AFTERNOON WILL DROP INTO THE 15 TO 20
PERCENT RANGE WITH GOOD OVERNIGHT RECOVERY ANTICIPATED. WEDNESDAY
AND THURSDAY...INCREASED EAST TO SOUTHEASTERLY FLOW IS ANTICIPATED
ACROSS SOUTHERN AND SOUTH CENTRAL ARIZONA...OTHERWISE WINDS WILL
FAVOR THE TYPICAL UPSLOPE/DOWNVALLEY PATTERNS WITH NO MAJOR WIND
EVENTS ANTICIPATED.

&&

.PSR WATCHES/WARNINGS/ADVISORIES...

AZ...NONE.

CA...NONE.

&&

$$

VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX

DISCUSSION...AJ
PREVIOUS DISCUSSION...VASQUEZ
AVIATION...NOLTE
FIRE WEATHER...LEINS/NOLTE







SOUTHWEST CALIFORNIA AREA FORECAST DISCUSSION

NWS LOS ANGELES/OXNARD CA

 200 PM PDT MON SEP 2 2013

.SYNOPSIS...
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
CONTINUE THROUGH TUESDAY...FAVORING THE MOUNTAINS OF LOS ANGELES AND
VENTURA COUNTIES AS WELL AS THE ANTELOPE VALLEY. OVERNIGHT LOWS AND
DAYTIME HIGHS WILL REMAIN ABOVE NORMAL THROUGH THE WEEK...WITH
ADDITIONAL WARMING THROUGH THE END OF THE WEEK...AND POSSIBLY A FEW
DEGREES OF COOLING ON THE WEEKEND.
&&

.SHORT TERM (TODAY-THU)...ANOTHER SLOW START TO AFTERNOON CONVECTION
IN THE MTNS TODAY BUT ENOUGH INSTABILITY AND MOISTURE TO KEEP SLIGHT
CHANCES GOING. SOUTHERLY FLOW IS STRONG ENOUGH TO LIMIT THE
POTENTIAL FOR FLASH FLOODING BUT STILL SOME CONCERNS THERE,
ESPECIALLY OUT IN THE ANTELOPE VALLEY WHERE IT DOESN`T TAKE MUCH TO
CAUSE PROBLEMS.

BIGGEST ADJUSTMENT TO THE FORECAST TODAY WAS TO ADD IN SMALL
SHOWER/TSTORM CHANCES TO ALL AREAS TONIGHT WITH A WAVE MOVING UP
FROM THE SOUTH, ORIGINATING FROM OLD TROPICAL STORM KIKO. WATER
VAPOR SHOWS WHAT APPEARS TO BE A LITLE UPPER LEVEL CIRCULATION NEAR
30N/120W MOVING SLOWLY NORTH WITH A FAIRLY LARGE BATCH OF MOISTURE
OUT AHEAD OF IT. THE GFS SEEMS TO HAVE THE BEST HANDLE ON IT, WITH
THE VORT AT 18Z ALMOST DEAD ON. THEN MOVING IT TO NEAR SAN NICOLAS
ISLAND AROUND 06Z AND INTO SRN SBA COUNTY AROUND 12Z. THE
MOISTURE THOUGH IS WELL AHEAD OF IT AND MODELS SHOW DECENT
INSTABILITY TONIGHT OVER THE ENTIRE AREA FROM SBA COUNTY SOUTH.
PWATS EXPECTED TO INCREASE AGAIN BACK UP TO CLOSE TO 2" BY TUESDAY
MORNING. AND THE HRRR MODEL ACTUALLY SHOWS SOME PRECIP DEVELOPING
LATER IN THE EVENING ACROSS VENTURA AND LA COUNTIES. SO GIVEN ALL
THIS IT SEEMS PRUDENT TO GO WITH SOME SLIGHT CHANCES FOR SHOWERS AND
TSTORMS ACROSS THE ENTIRE AREA FROM SBA COUNTY SOUTH TONIGHT, THEN
SPREADING UP INTO SLO COUNTY LATER TONIGHT AND TUESDAY MORNING AS
THAT VORT MOVES NORTH. NKX RADAR PICKING UP ON SOME RETURNS BUT THEY
ARE OVER 100 NM OFFSHORE SO IT`S HARD TO SAY IF ANYTHING IS REACHING
THE SURFACE.

ONCE THAT WAVE MOVES THROUGH WE SHOULD TRANSITION TO MORE A TYPICAL
MTN/DESERT THUNDERSTORM PATTERN IN THE AFTERNOON. WITH THE HIGHER
PWATS AND 850 DEWPOINTS WE WILL HAVE TO AGAIN CONSIDER FLASH FLOOD
WATCHES FOR THE INTERIOR, THOUGH STEERING WINDS ARE STILL IN THE
15-20 KT RANGE SO THAT WILL HELP KEEP STORMS MOVING A BIT. THE OTHER
FACTOR TO CONSIDER FOR TOMORROW IS THE AMOUNT OF MID LEVEL CLOUD
COVER LEFT OVER FROM TONIGHT THAT MAY DELAY THE HEATING.

HIGHS EXPECTED TO WARM A COUPLE DEGREES MOST AREAS TUESDAY WITH
SLIGHTLY HIGHER HUMIDITIES AS WELL. CLOUDS WILL PLAY A ROLE HERE TOO
SO IF CLEARING IS DELAYED THEN TEMPS MAY NOT WARM UP AS MUCH AS
EXPECTED.

HIGH PRESSURE EXPECTED TO EXPAND WESTWARD FOR THE MIDDLE AND END OF
THE WEEK AND WILL CONTINUE THE WARMING TREND. TEMPS EXPECTED TO PEAK
THU/FRI WITH WARMER VALLEY HIGHS 100-105 AND COASTAL AREAS AWAY FROM
THE IMMEDIATE COAST IN THE 80S TO LOWER 90S. STILL ENOUGH MOISTURE
AND INSTABILITY TO KEEP SOME SMALL TSTORM CHANCES DURING THE
AFTERNOON, MAINLY EASTERN LA COUNTY.

.LONG TERM (FRI-MON)...AFTER ANOTHER HOT DAY FRIDAY TEMPS EXPECTED
TO TREND COOLER THROUGH THE WEEKEND, THOUGH NOT DRAMATICALLY. STILL
SHOULD BE AT LEAST A FEW DEGREES ABOVE NORMAL EVEN BY MONDAY. TSTORM
CHANCES SEEM VERY LOW AT THIS TIME WITH MONSON MOISTURE PUSHED EAST
OF THE AREA, THOUGH THAT COULD EASILY CHANGE.

&&

.AVIATION...02/1800Z.
POOR TO MODERATE CONFIDENCE IN THE 18Z TAFS. AN AREA OF SUBTROPICAL
MOISTURE IS MOVING TOWARD THE FORECAST AREA AND WILL ARRIVE TONIGHT.
THE EXTENSIVE MID LEVEL CLOUDINESS IS EXPECTED TO DISRUPT MARINE
CLOUD FORMATION AND LOW CLOUD DEVELOPMENT HAS BEEN SCALED BACK AT
THE COASTAL SITES FOR TONIGHT. THERE IS POOR CONFIDENCE IN THE TAFS
FOR COASTAL LA COUNTY AND MODERATE CONFIDENCE ELSEWHERE.

KLAX...POOR CONFIDENCE IN THE DEVELOPMENT OF MARINE CLOUDS TONIGHT.
DECIDED TO SCALE BACK LOW CLOUD COVERAGE TO SCT DUE TO EXTENSIVE MID
LEVEL CLOUD COVERAGE. THERE IS A 40 PERCENT CHANCE OF IFR CEILINGS
CAUSED BY MARINE CLOUDS.

KBUR...MODERATE CONFIDENCE IN VFR CONDITIONS THROUGH TUESDAY.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY (SEE LAXMWWLOX).
MARINE WEATHER STATEMENT (SEE LAXMWSLOX).

&&

$$

PUBLIC...MW
AVIATION...SWEET
SYNOPSIS...BARTLING

WWW.WEATHER.GOV/LOSANGELES






AREA FORECAST DISCUSSION

NWS TAUNTON MA

 402 PM EDT MON SEP 2 2013

.SYNOPSIS...

SHOWERS AND THUNDERSTORMS WILL DIMINISH OVERNIGHT AS DRIER AIR
WORKS INTO THE REGION. BUT ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS IS ANTICIPATED TUESDAY...A FEW OF WHICH MAY BE
STRONG TO SEVERE WITH GUSTY WINDS AND HEAVY RAIN. COOLER AND
DRIER WEATHER IS ANTICIPATED INTO MIDWEEK WITH ANOTHER CHANCE OF
STORMS POSSIBLY BY LATE WEEK...AND ANOTHER CHANCE SUNDAY.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...

**FLASH FLOOD WATCH REMAINS IS IN EFFECT TILL 11 PM**
**TURN AROUND...DONT DROWN...
**PLEASE TO NOT DRIVE INTO FLOODED ROADWAYS**

4 PM UPDATE...

UTILIZING THE HRRR AND WRF-ARW TO MAKE DETERMINATIONS ON SHOWER
AND THUNDERSTORM OUTCOMES INTO THE EVENING HOURS. AS MENTIONED IN
EARLIER DISCUSSIONS...LOW-LEVEL FORCING IS APPARENT WHERE THE
BOUNDARY LAYER DESTABILIZES RESULTING IN A LOCALIZATION OF THETAE
LOW-LEVEL CONVERGENCE UNDERNEATH BROAD-SCALE LIFTING OF CYCLONIC
FLOW. A JUICY TROPICAL AIRMASS IN PLACE WITH PWATS AROUND 2+
INCHES...WITH SATURATED SOILS FROM RAINS THE PAST 24 HOURS...AND
THE THREAT OF FLASH FLOODING CONTINUES.

WILL SEE ACTIVITY CONTINUE FOR THE NEXT FEW HOURS...BUT NOTING WATER
VAPOR SATELLITE...DRIER AIR IS WORKING ITS WAY AROUND THE BROADER
LOW PRESSURE CENTER OVER THE NORTHERN GREAT LAKES. TOWARDS EVENING
THIS DRIER AIR SHOULD DISSIPATE ACTIVITY AS SEEN CONSISTENTLY IN
ALL FORECAST GUIDANCE. WILL ALLOW THE FLASH FLOOD WATCH DROP
ACCORDINGLY INTO THE EARLY EVENING HOURS.

TONIGHT...

WHILE THE MID- TO UPPER-LEVEL TROUGH AMPLIFIES...DRIER AIR WORKS
ITS WAY IN. THE BETTER THETAE AXIS OF MOISTURE SHIFTS OFFSHORE AND
OUT TO SEA. ACTIVITY WILL LINGER EASTWARD TOWARDS MIDNIGHT
COLLOCATED WITH THE LOW-LEVEL THETAE CONVERGENCE. THEREAFTER A
LULL IN ACTIVITY IS ANTICIPATED AS THE COLD FRONT PUSHES SOUTH AND
EAST OUT OF THE GREAT LAKES REGION TOWARDS SOUTHERN NEW ENGLAND.
WILL BRING POPS ON A DOWNWARD TREND FROM CHANCE TO SLIGHT CHANCE
WEST TO EAST.

FOG WILL BE AN ISSUE FOR THE SOUTH-SOUTHEAST COAST...AS WELL AS
INTERIOR COASTAL PLAIN. DEWPOINTS IN THE LOW 70S AND RECENT RAINS
WILL MAKE FOR A SOUPY BOUNDARY LAYER PROFILE OVERNIGHT. VISIBILITIES
DOWN TO A QUARTER MILE OR LESS IN PARTS WILL BE POSSIBLE AS WINDS
WEAKEN.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...

TUESDAY...

THUNDERSTORMS WILL BE POSSIBLE AHEAD OF A SURFACE COLD FRONT
PUSHING ACROSS SOUTHERN NEW ENGLAND DURING THE MORNING INTO
AFTERNOON HOURS. A FEW OF THESE STORMS MAY BE STRONG TO SEVERE BUT
THERE REMAINS A FAIR AMOUNT OF UNCERTAINTY.

WHAT IS SEEMINGLY CLEAR...IS THAT DEEP LAYER ASCENT IS ENTIRELY
PLAUSIBLE. THE MAIN MID-LEVEL IMPULSE COUPLED WITH THE RIGHT-REAR
QUADRANT OF AN ENHANCING UPPER LEVEL JET SHOULD PROVIDE ENHANCED
ASCENT THROUGH A LAYER OF DECENT MID-LEVEL LAPSE RATES...6 C/KM.
THIS LIFT APPEARS TO BE COLLOCATED ALONG THE SURFACE COLD FRONT
AND ATTENDANT FRONTOGENESIS...ALONG AND AHEAD OF WHICH WILL BE A
SECONDARY TONGUE OF DECENT THEATE AIR.

BUT THE KEY IS TIMING AND INITIAL CONDITIONS. THERE IS SOME
UNCERTAINTY AS TO THE CLEARING PROFILE AHEAD OF THE COLD FRONT
ALLOWING BOUNDARY LAYER DESTABILIZATION. THE FRONT ITSELF MAY
ENCROACH WELL EAST INTO THE FORECAST AREA BY MIDDAY BEFORE ANY
THUNDERSTORM ACTIVITY GETS UNDERWAY. IN ADDITION...THE PREVIOUS
EVENINGS DRY SLOT MAY CLEAR OUT MID- TO UPPER- LEVEL CLOUDS...BUT
BOUNDARY LAYER MOISTURE LIKELY AS LOW CLOUDS AND FOG BY MORNING
MAY LINGER AND LIMIT INSTABILITY. ON A FINAL NOTE...THERE ARE
SUBTLE FORECAST SOUNDING INDICATIONS OF THIN CAPE PROFILES AND
PERHAPS A DRY AIR SUBSIDENCE INVERSION AROUND H7.

CONSIDERING ALL FACTORS...THERE IS SOME POSSIBILITY OF THE
BOUNDARY LAYER DESTABILIZING EAST OF THE CONNECTICUT RIVER VALLEY.
AND COLLOCATING WITH DEEP-LAYER ASCENT. THE WRF-ARW HAS BEEN DOING
WELL THE PAST FEW DAYS WITH THUNDERSTORM OUTCOMES AND EXHIBITS
SOME DEVELOPMENT WITH THE 02.12Z RUN. HAVE HINTED LIKELY POPS
WHERE GREATEST CONFIDENCE LIES...ELSEWHERE CHANCE POPS.

WITH UNIDIRECTIONAL 0-6 KM BULK SHEAR UP TO AROUND 35 KNOTS AND
THE POSSIBILITY OF INSTABILITY AROUND 1000 J/KG...CAN NOT RULE OUT
THE POTENTIAL FOR STRONG TO SEVERE STORMS OVER SOUTHERN AND
SOUTHEAST NEW ENGLAND. MAIN THREATS WILL BE HEAVY RAIN AND GUSTY
WINDS. WILL NOT RULE OUT THE POSSIBILITY OF HAIL. COULD SEE A GOOD
TURNING PROFILE WITHIN THE LOW-LEVELS IF WINDS ARE ABLE TO BACK
AHEAD OF THE COLD FRONT.

THE SURFACE COLD FRONT IS PROGGED TO BE ALONG THE I-95 BOSTON-
PROVIDENCE CORRIDOR BY EVENING.

TUESDAY NIGHT...

SHOWER AND THUNDERSTORM ACTIVITY DIMINISHES TOWARDS MIDNIGHT AS
THE SURFACE COLD FRONT SWEEPS OFFSHORE. WET WEATHER WILL LINGER
FOR THE FAR EAST AND SOUTHEAST. THEREAFTER...WILL SEE WESTERLY
FLOW TO THE REAR OF THE FRONT USHER COOLER AND DRIER AIR. GRADUAL
CLEARING TOWARDS MORNING.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...

HIGHLIGHTS...

  * ANOTHER ROUND OF SHOWERS POSSIBLE WITH BACK DOOR FRONT THU
  * MUCH COOLER/DRIER WEATHER LATE WEEK
  * MORE STORMS POSSIBLE OVER THE WEEKEND WITH A COLD FRONT

MODELS ARE IN GOOD AGREEMENT THROUGH MUCH OF THE LONG TERM.  THE
MODELS HAVE BEEN FAIRLY CONSISTENT OVER THE LAST FEW DAYS WITH THE
GENERAL SYNOPTIC PATTERN SO CONFIDENCE IN THE BROAD SCALE IS FAIRLY
HIGH.  THERE ARE SOME DETAILS AND IN SOME CASES TIMING THAT STILL
NEED TO BE IRONED OUT...PARTICULARLY LATE IN THE WEEKEND INTO EARLY
NEXT WEEK.  LOW PRESSURE MOVING OUT OF QUEBEC AND INTO THE MARITIMES
BRINGS A BACK DOOR COLD FRONT THROUGH SOUTHERN NEW ENGLAND THURSDAY.
WITH IT MAY COME A FEW SHOWERS AND THUNDERSTORMS. HIGH PRESSURE
BUILDS IN FOR FRIDAY AND AT LEAST A PART OF SATURDAY AND THEN
ANOTHER COLD FRONT MOVES THROUGH THE AREA NEXT WEEKEND.  WILL USE A
BLEND OF THE PREVIOUS FORECAST AND THE WPC GRIDS THAT INCORPORATE
SOME OF THE ENSEMBLE DATA.

WEDNESDAY AND THURSDAY...WHILE THE SHORTWAVE TROUGH MOVES
OFFSHORE...THE BROADER UPPER TROUGH MOVES OVER SOUTHERN NEW ENGLAND
WEDNESDAY.  LOW PRESSURE MOVING INTO THE MARITIMES WEDNESDAY WILL
BRING A BACK DOOR COLD FRONT SOUTH THROUGH NORTHERN NEW ENGLAND BY
EARLY THURSDAY MORNING AND THROUGH SOUTHERN NEW ENGLAND THURSDAY
EVENING.  BOTH THE ECMWF AND GFS INDICATE SOME LIGHT QPF ASSOCIATED
WITH THE FRONTAL PASSAGE SO THERE IS POTENTIAL FOR SHOWERS WITH THE
FRONT.

FRIDAY AND SATURDAY...HIGH PRESSURE BUILDS IN BEHIND THE BACK DOOR
FRONT. WITH A MORE NORTHERLY FLOW THROUGH MUCH OF THE DAY AND MUCH
COOLER TEMPERATURES TO THE NORTH...EXPECT COOLER THAN SEASONABLE
TEMPS FRIDAY.  THEN SATURDAY AS HIGH PRESSURE MOVES AWAY FROM THE
REGION...TEMPERATURES SHOULD MODERATE SOMEWHAT.

SUNDAY AND MONDAY...THE GREATEST DIFFERENCES BETWEEN THE MODELS ARE
IN THIS PERIOD...AS USUAL.  HOWEVER...EVEN WITH THIS TIME PERIOD...
THEY ARE IN REMARKABLY GOOD AGREEMENT.  ANOTHER COLD FRONT MOVES
THROUGH SOUTHERN NEW ENGLAND WITH LOW PRESSURE IN THE MARITIMES
SUNDAY THEN HIGH PRESSURE BUILDS BACK INTO THE REGION MONDAY.

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

18Z UPDATE...

LOW CONFIDENCE FORECAST CONTINUES. FOR THE REMAINDER OF TODAY...
WITH ANY SHRA/TSRA MVFR-IFR IMPACTS ARE ANTICIPATED. OTHERWISE
MVFR-VFR PREVAILS. ISSUANCE OF AWW/S LIKELY NECESSARY INTO THE
EVENING WITH TSRA AND THE EXPECTATION FOR CLOUD TO GROUND
LIGHTNING.

CONDITIONS ARE EXPECTED TO QUIET OVERNIGHT...YET FOG ANTICIPATED
TO BUILD BACK IN...ESPECIALLY ALONG THE SOUTH/SOUTHEAST COAST.
WILL SEE CIGS AND VSBYS LOWER TO IFR-VLIFR. WITH THE APPROACHING
COLD FRONT TOWARDS MORNING...WINDS WILL BACK OUT OF THE WEST AND
CONDITIONS WILL IMPROVE AS CIGS LIFT AND FOG DISSIPATES. BUT THERE
REMAINS A THREAT INTO THE LATE MORNING INTO AFTERNOON HOURS OF
SHRA/TSRA DEVELOPING AGAIN ALONG THE COLD FRONT. MVFR/IFR IMPACTS
ONCE AGAIN WILL BE POSSIBLE...OTHERWISE VFR WITH WESTERLY FLOW
INTO WEDNESDAY MORNING.

KBOS TERMINAL...MODERATE CONFIDENCE IN TAF. SHRA/TSRA BUILDING
AROUND THE TERMINAL WILL REMAIN A THREAT INTO EVENING.

KBDL TERMINAL...MODERATE CONFIDENCE IN TAF. A LULL FOR NOW...BUT
EXPECT ACTIVITY SOUTH AND WEST TO BUILD BACK IN LATER THIS
AFTERNOON CONTINUING INTO EVENING. WITH ANY SHRA/TSRA...MVFR-IFR
POSSIBLE.

OUTLOOK...WEDNESDAY THROUGH SATURDAY...

MODERATE TO HIGH CONFIDENCE.  MAINLY VFR.  LOW CONFIDENCE IN ISOLD
SHRA/TSRA THURSDAY RESULTING IN BRIEF MVFR/IFR CONDITIONS.

&&

.MARINE...

FORECASTER CONFIDENCE LEVELS...

LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.

4 PM UPDATE...

SHOWERS AND THUNDERSTORMS WILL LINGER ACROSS THE WATERS INTO THE
EVENING HOURS AND AROUND MIDNIGHT. MUCH OF THE ACTIVITY SHOULD
DIMINISH TOWARDS MORNING. FOG WILL BE AN ISSUE ALONG THE SOUTH-
SOUTHEAST WATERS WITH VISIBILITIES DOWN TO A QUARTER MILE OR LESS
POSSIBLE.

A SURFACE COLD FRONT WILL APPROACH THE WATERS TOWARDS MIDDAY
ALONG AND AHEAD OF WHICH WILL BE RENEWED CHANCES FOR SHOWERS AND
THUNDERSTORMS ALONG WITH SOUTHWESTERLY WIND GUSTS OF AROUND 20
KTS. STORMS COULD BECOME STRONG TO SEVERE WITH GALE FORCE WIND
GUSTS. SEAS LOCALLY MAY EXCEED 5 FEET WITH STORMS...OTHERWISE STAY
JUST BELOW. WILL SEE ACTIVITY EXIT OUT TO SEA LATE TUESDAY INTO
TUESDAY EVENING...WINDS AND SEAS DIMINISH.


OUTLOOK...WEDNESDAY THROUGH SATURDAY...

QUIET BOATING WEATHER EXPECTED WITH WESTERLY WINDS AND SEAS BELOW
SMALL CRAFT CRITERIA.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...

CT...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR CTZ002>004.
MA...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR MAZ002>021-
     026.
NH...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR NHZ011-012-
     015.
RI...FLASH FLOOD WATCH UNTIL 11 PM EDT THIS EVENING FOR RIZ001>007.
MARINE...NONE.

&&

$$

SYNOPSIS...RLG/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...RLG
AVIATION...RLG/SIPPRELL
MARINE...RLG/SIPPRELL




AREA FORECAST DISCUSSION

NWS ALBANY NY

 150 PM EDT MON SEP 2 2013

.SYNOPSIS...
ANOTHER WARM...HUMID AND WET DAY ACROSS THE AREA AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. THE BEST CHANCES FOR STORMS ARE
EXPECTED THIS AFTERNOON INTO THE EARLY EVENING. SOME STORMS WILL
PRODUCE VERY HEAVY DOWNPOURS. A DRIER AIRMASS WILL BE USHERED IN
LATE TONIGHT AND TUESDAY AS THE SYSTEM`S COLD FRONT MOVES ACROSS
THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 130 PM EDT...SCATTERED CONVECTION HAS DEVELOPING AND SHOWING
SOME SIGNS OF TRAINING ACROSS THE CATSKILLS WITH ADDITIONAL MORE
ROBUST CONVECTIVE TRENDS FURTHER UPSTREAM OVER WESTERN NY.  WE WILL
KNOCK DOWN POPS FOR A BRIEF TIME THIS AFTERNOON WITH A RAPID
INCREASE TOWARD MID-LATE AFTERNOON AS THE COMBINATION OF UPSTREAM
TROUGH AXIS AND RATHER DIFFUSE SURFACE BOUNDARY APPROACHES.  PWATS
REMAIN UP TO 2 INCHES WITH UPSTREAM SBCAPES JUST BELOW 3K J/KG AND
MARGINAL SHEAR PARAMETERS AROUND 20KTS.  PER THE HRRR...SEEMS A
SCT-BKN LINE OF CONVECTION WILL DEVELOP AND MOVE ACROSS THE REGION
BUT ITS INTENSITY REMAINS IN QUESTION DUE TO THE CONSIDERABLE CLOUD
COVER THE REGION HAS EXPERIENCED THUS FAR.  GOES RSO 1KM VISIBLE
SUGGEST SOME MORE BREAKS INTO THE MOHAWK VALLEY SO WE WILL CONTINUE
TO MONITOR TRENDS VERY CLOSELY.  FLOOD WATCHES REMAIN IN EFFECT FOR
THE EASTERN PORTIONS OF THE CWFA.

PREV DISC...
AS OF 1022 AM EDT...MUCH OF THIS MORNINGS SHOWERS AND
THUNDERSTORMS HAVE MOVED EAST OF THE AREA. HOWEVER...THERE IS
STILL A CLUSTER OF CONVECTION WITH HEAVY RAIN OVER DUTCHESS AND
LITCHFIELD COUNTIES LATE THIS MORNING. THIS ACTIVITY IS TIED TO A
SMALL-SCALE UPPER LEVEL DISTURBANCE SEEN WELL ON WATER VAPOR
IMAGERY. THIS AREA OF CONVECTION SHOULD CONTINUE TO SLOWLY MOVE
EASTWARD THROUGH EARLY AFTERNOON.

THEN ATTENTION SHIFTS TO THE WEST...WHERE ADDITIONAL SHOWER AND
THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ACROSS CENTRAL NY
ASSOCIATED WITH THE NEXT UPPER LEVEL DISTURBANCE OVER WESTERN NY
AND A PRE-FRONTAL TROUGH AT THE SURFACE. HI RES MODELS INCLUDING
THE 3KM HRRR AND OUR LOCAL HIRESWRF INDICATE CONVECTION INCREASING
IN COVERAGE BY EARLY TO MID AFTERNOON ACROSS THE AREA AS LARGE
SCALE ASCENT STRENGTHENS.

ONCE AGAIN THE MAIN THREAT WILL BE HEAVY RAINFALL AND POSSIBLE
FLASH FLOODING...AS PWATS ARE STILL RUNNING ANOMALOUSLY HIGH. THE
READING FROM THE 12Z KALB SOUNDING WAS 1.70 INCHES. GENERALLY
TALL/SKINNY CAPE PROFILE FAVORS THE HEAVY RAIN THREAT. DEPENDING
ON HOW MUCH LIMITED SUNSHINE CAN BREAK THROUGH THE CLOUDS...THERE
IS AN ADDITIONAL THREAT FOR STRONG GUSTY WINDS ASSOCIATED WITH
THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. THE BETTER THREAT
AREA APPEARS TO BE WESTERN/CENTRAL NY WHERE MORE CLEARING IS
TAKING PLACE. FOR OUR AREA EXPECTING AROUND 1000-1500 K/KG OF
SBCAPE TO BUILD...WITH DEEP LAYER SHEAR IN THE 25 TO 35 KT
RANGE...WHICH COULD RESULT IN SOME MORE ORGANIZED CLUSTERS OF
STORMS. WILL CONTINUE TO MONITOR TRENDS INTO THE AFTERNOON.

FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE TACONICS...THE
BERKSHIRES...LITCHFIELD COUNTY AND SOUTHERN VERMONT VALID INTO
EARLY THIS EVENING. PORTIONS OF THIS AREA RECEIVED HEAVY RAINFALL
SUNDAY AND AGAIN OVERNIGHT/THIS MORNING MAKING THEM VULNERABLE TO
FLASH FLOODING. HOWEVER....WE CAN NOT RULE OUT THE POSSIBILITY FOR
ISOLATED FLASH FLOODING ACROSS EAST CENTRAL NEW YORK TODAY BUT
FORECAST CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS
TIME.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
THE UPPER TROUGH STILL HAS TO SWING THROUGH AND IT WILL DO SO
TUESDAY AND TUESDAY NIGHT FINALLY MOVING OFF TO THE EAST AFTER
MIDNIGHT. EXPECTING SCATTERED SHOWERS ACROSS THE AREA AS THE TROUGH
AXIS APPROACHES. HEIGHTS WILL THEN RISE A BIT LATE TUESDAY NIGHT
INTO WEDNESDAY. HOWEVER...AN UPPER LEVEL LOW WILL DEVELOP OVER
HUDSON BAY CANADA DROPPING A REINFORCING COLD FRONT INTO THE REGION
WEDNESDAY NIGHT.

TEMPERATURES TUESDAY WILL BE SEASONABLY WARM...WITH MUCH MORE
COMFORTABLE DEW POINTS THAN RECENT DAYS...DROPPING INTO THE 50S.

TEMPERATURES WEDNESDAY WILL BE SIMILAR AND EVEN A BIT WARMER THAN
TUESDAY ACROSS THE HIGHER TERRAIN WITH THE HELP OF SOME SUNSHINE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
THE EXTENDED FORECAST FOLLOWS CLOSELY THE HPC GUIDANCE THIS MORNING
DUE TO THE ACTIVE ONGOING WX.  THE MID WEEK INTO NEXT WEEKEND WILL
BE DOMINATED BY A MEAN LONGWAVE TROUGH.  THIS WILL PROVIDE THE
REGION WITH A PREVAILING NW FLOW ALOFT AND TEMPS NEAR NORMAL TO
BELOW NORMAL FOR THE STRETCH. HUMIDITY LEVELS WILL BE LOW AND
COMFORTABLE.

THU-FRI...A COLD FRONT DIPS SOUTH OF THE REGION WITH A COOL CANADIAN
AIR MASS BUILDING IN FROM THE GREAT LAKES REGION AND OHIO VALLEY.
H850 TEMPS FALL TO +2C TO +5C ACCORDING THE LATEST GFS THU NIGHT.
MAX TEMPS WILL RANGE FROM THE U50S TO M60S OVER THE SRN DACKS TO
LOWER TO M70S FROM THE CAPITAL REGION SOUTH AND EAST.  LOWS WILL BE
IN THE 40S WITH SOME 30S OVER THE DACKS.  FRIDAY WILL FEATURE LOTS
OF SUNSHINE AND TEMPS ABOUT 5-7 DEGREES BELOW NORMAL WITH MID AND
U60S OVER THE HILLS AND MTNS...AND L70S IN THE VALLEYS.

FRI NIGHT-SAT...THE SFC HIGH MOVES SOUTH AND EAST OF THE
REGION...AS A WARM FRONT BRIEFLY LIFTS THROUGH WITH LITTLE IF ANY
PCPN. LOWS WILL STILL BE IN THE M40S TO M50S. A COLD FRONT SLIDES
S/SE FROM SRN ONTARIO AND SWERN QUEBEC.  THE BEST CHC FOR SHOWERS
WILL BE FROM THE CAPITAL REGION NORTH AND WEST DURING THE DAY...AND
SLIGHT CHC VALUES TO THE SOUTH AND EAST. THE CONVERGENCE WITH THIS
BOUNDARY IS NOT VERY STRONG.

SATURDAY NIGHT INTO SUNDAY...THE COLD FRONT SINKS SOUTH OF THE FCST
AREA WITH A REINFORCING SURGE OF COOL...CANADIAN AIR. A SLIGHT TO
LOW CHC OF SHOWERS LINGERS INTO SUNDAY MORNING.  A BROAD ANTICYCLONE
SETTLES OVER NY AND NEW ENGLAND TO CLOSE THE WEEKEND AND OPEN NEXT
WEEK. TEMPS WILL FINISH NEAR SEASONABLE NORMALS.

OVERALL...PCPN LOOKS BELOW NORMAL WITH TEMPS SLIGHTLY BELOW NORMAL
IN THE LONG TERM.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A STRONG UPPER LEVEL LOW AND SURFACE COLD FRONT WILL APPROACH FROM
SOUTHEAST ONTARIO AND SOUTHWEST QUEBEC INTO THIS EVENING...BRINGING
PERIODS OF SHOWERS AND THUNDERSTORMS TO THE TERMINALS.

CONDITIONS ARE MAINLY VFR EARLY THIS AFTERNOON...BUT WITHIN ANY
SHRA/TSRA OCCASIONAL MVFR AND EVEN BRIEF IFR CONDITIONS WILL BE
LIKELY. WITH AT LEAST SCATTERED COVERAGE OF CONVECTION...THERE IS
ENOUGH CONFIDENCE TO MENTION TSRA IN TEMPOS FOR 3-4 HOURS FROM MID
AFTERNOON INTO THE EVENING. HIGHEST PROBABILITY FOR A TSRA IMPACTING
A SPECIFIC TERMINAL IS KPOU...SO WILL MENTION IFR CONDITIONS IN THE
TEMPO THERE.

OTHERWISE...CONVECTION SHOULD DECREASE THIS EVENING AND ESPECIALLY
AFTER DARK WITH LOSS OF INSTABILITY AND THE FRONTAL BOUNDARY MOVING
ACROSS THE AREA. HOWEVER...THERE WILL BE PLENTY OF RESIDUAL
LOW-LEVEL MOISTURE...SO LOW STRATUS AND/OR SOME FOG FORMATION IS
LIKELY. MVFR/IFR CONDITIONS POSSIBLE...WITH THE GREATEST LIKELIHOOD
FOR IFR AT KGFL/KPSF.

VFR CONDITIONS SHOULD RETURN BY LATE TUESDAY MORNING...AS A DRIER
NORTHWEST FLOW DEVELOPS ACROSS THE REGION. THERE IS THE RISK FOR AN
ISOLATED SHOWER AS THE UPPER LEVEL TROUGH AXIS PASSES THROUGH...BUT
COVERAGE IS TOO LOW TO MENTION IN TAFS AT THIS TIME.

SURFACE WINDS WILL BE SOUTHERLY AROUND 5 TO 7 KT INTO THE
EVENING...THEN BECOMING LIGHT AND VARIABLE. WINDS WILL SHIFT TO THE
NORTHWEST AND INCREASE TO AROUND 5 TO 10 KT TUESDAY MORNING. WINDS
WILL BE GUSTY AND ERRATIC IN AND NEAR ANY THUNDERSTORMS.

OUTLOOK...
TUESDAY NIGHT TO FRIDAY: NO OPERATIONAL IMPACT.  NO SIG WX.

&&

.FIRE WEATHER...
WARM...HUMID AND WET WEATHER WILL CONTINUE TODAY. A DRIER AIRMASS
WILL BE USHERED IN LATE TONIGHT INTO TUESDAY AS COLD FRONT MOVES
ACROSS THE REGION.

&&

.HYDROLOGY...
PRECIPITABLE WATER VALUES ARE HIGH CLOSE TO 2 INCHES SO VERY HEAVY
DOWNPOURS WILL OCCUR WITH SOME STORMS. WINDS WILL REMAIN LIGHT
RESULTING IN SLOW MOVEMENT OF THE STORMS.

HAVE DECIDED TO ISSUE A FLASH FLOOD WATCH FOR THE TACONICS...THE
BERKSHIRES...LITCHFIELD COUNTY AND SOUTHERN VERMONT VALID INTO EARLY
THIS EVENING. PORTIONS OF THIS AREA RECEIVED HEAVY RAINFALL SUNDAY
AND AGAIN OVERNIGHT/EARLY THIS MORNING MAKING THEM MORE VULNERABLE
TO FLASH FLOODING. HOWEVER....WE CAN NOT RULE OUT THE POSSIBILITY
FOR ISOLATED FLASH FLOODING ACROSS EAST CENTRAL NEW YORK TODAY BUT
FORECAST CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS
TIME.

A DRIER AIRMASS WILL FINALLY BE USHERED INTO THE REGION LATE
TONIGHT AND TUESDAY AS COLD FRONT MOVES ACROSS THE REGION.

WIDESPREAD PRECIPITATION IS NOT EXPECTED THIS WEEK AS HIGH PRESSURE
WILL DOMINATE MUCH OF THE TIME. HOWEVER...THERE WILL BE A COUPLE/FEW
FRONTAL PASSAGES WHICH WILL BRING THE THREAT OF SHOWERS TO THE
AREA.

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...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ054-061-
     066.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VTZ013>015.

&&

$$
SYNOPSIS...IAA
NEAR TERM...IAA/JPV/BGM
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...JPV
FIRE WEATHER...IAA
HYDROLOGY...IAA/WASULA











AREA FORECAST DISCUSSION

NWS ALBANY NY

 138 PM EDT MON SEP 2 2013

.SYNOPSIS...
ANOTHER WARM...HUMID AND WET DAY ACROSS THE AREA AS A LOW PRESSURE
SYSTEM APPROACHES FROM THE WEST. THE BEST CHANCES FOR STORMS ARE
EXPECTED THIS AFTERNOON INTO THE EARLY EVENING. SOME STORMS WILL
PRODUCE VERY HEAVY DOWNPOURS. A DRIER AIRMASS WILL BE USHERED IN
LATE TONIGHT AND TUESDAY AS THE SYSTEM`S COLD FRONT MOVES ACROSS
THE REGION.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1022 AM EDT...MUCH OF THIS MORNINGS SHOWERS AND
THUNDERSTORMS HAVE MOVED EAST OF THE AREA. HOWEVER...THERE IS
STILL A CLUSTER OF CONVECTION WITH HEAVY RAIN OVER DUTCHESS AND
LITCHFIELD COUNTIES LATE THIS MORNING. THIS ACTIVITY IS TIED TO A
SMALL-SCALE UPPER LEVEL DISTURBANCE SEEN WELL ON WATER VAPOR
IMAGERY. THIS AREA OF CONVECTION SHOULD CONTINUE TO SLOWLY MOVE
EASTWARD THROUGH EARLY AFTERNOON.

THEN ATTENTION SHIFTS TO THE WEST...WHERE ADDITIONAL SHOWER AND
THUNDERSTORM ACTIVITY HAS ALREADY DEVELOPED ACROSS CENTRAL NY
ASSOCIATED WITH THE NEXT UPPER LEVEL DISTURBANCE OVER WESTERN NY
AND A PRE-FRONTAL TROUGH AT THE SURFACE. HI RES MODELS INCLUDING
THE 3KM HRRR AND OUR LOCAL HIRESWRF INDICATE CONVECTION INCREASING
IN COVERAGE BY EARLY TO MID AFTERNOON ACROSS THE AREA AS LARGE
SCALE ASCENT STRENGTHENS.

ONCE AGAIN THE MAIN THREAT WILL BE HEAVY RAINFALL AND POSSIBLE
FLASH FLOODING...AS PWATS ARE STILL RUNNING ANOMALOUSLY HIGH. THE
READING FROM THE 12Z KALB SOUNDING WAS 1.70 INCHES. GENERALLY
TALL/SKINNY CAPE PROFILE FAVORS THE HEAVY RAIN THREAT. DEPENDING
ON HOW MUCH LIMITED SUNSHINE CAN BREAK THROUGH THE CLOUDS...THERE
IS AN ADDITIONAL THREAT FOR STRONG GUSTY WINDS ASSOCIATED WITH
THUNDERSTORMS THIS AFTERNOON INTO THE EVENING. THE BETTER THREAT
AREA APPEARS TO BE WESTERN/CENTRAL NY WHERE MORE CLEARING IS
TAKING PLACE. FOR OUR AREA EXPECTING AROUND 1000-1500 K/KG OF
SBCAPE TO BUILD...WITH DEEP LAYER SHEAR IN THE 25 TO 35 KT
RANGE...WHICH COULD RESULT IN SOME MORE ORGANIZED CLUSTERS OF
STORMS. WILL CONTINUE TO MONITOR TRENDS INTO THE AFTERNOON.

FLASH FLOOD WATCH REMAINS IN EFFECT FOR THE TACONICS...THE
BERKSHIRES...LITCHFIELD COUNTY AND SOUTHERN VERMONT VALID INTO
EARLY THIS EVENING. PORTIONS OF THIS AREA RECEIVED HEAVY RAINFALL
SUNDAY AND AGAIN OVERNIGHT/THIS MORNING MAKING THEM VULNERABLE TO
FLASH FLOODING. HOWEVER....WE CAN NOT RULE OUT THE POSSIBILITY FOR
ISOLATED FLASH FLOODING ACROSS EAST CENTRAL NEW YORK TODAY BUT
FORECAST CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS
TIME.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
THE UPPER TROUGH STILL HAS TO SWING THROUGH AND IT WILL DO SO
TUESDAY AND TUESDAY NIGHT FINALLY MOVING OFF TO THE EAST AFTER
MIDNIGHT. EXPECTING SCATTERED SHOWERS ACROSS THE AREA AS THE TROUGH
AXIS APPROACHES. HEIGHTS WILL THEN RISE A BIT LATE TUESDAY NIGHT
INTO WEDNESDAY. HOWEVER...AN UPPER LEVEL LOW WILL DEVELOP OVER
HUDSON BAY CANADA DROPPING A REINFORCING COLD FRONT INTO THE REGION
WEDNESDAY NIGHT.

TEMPERATURES TUESDAY WILL BE SEASONABLY WARM...WITH MUCH MORE
COMFORTABLE DEW POINTS THAN RECENT DAYS...DROPPING INTO THE 50S.

TEMPERATURES WEDNESDAY WILL BE SIMILAR AND EVEN A BIT WARMER THAN
TUESDAY ACROSS THE HIGHER TERRAIN WITH THE HELP OF SOME SUNSHINE.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
THE EXTENDED FORECAST FOLLOWS CLOSELY THE HPC GUIDANCE THIS MORNING
DUE TO THE ACTIVE ONGOING WX.  THE MID WEEK INTO NEXT WEEKEND WILL
BE DOMINATED BY A MEAN LONGWAVE TROUGH.  THIS WILL PROVIDE THE
REGION WITH A PREVAILING NW FLOW ALOFT AND TEMPS NEAR NORMAL TO
BELOW NORMAL FOR THE STRETCH. HUMIDITY LEVELS WILL BE LOW AND
COMFORTABLE.

THU-FRI...A COLD FRONT DIPS SOUTH OF THE REGION WITH A COOL CANADIAN
AIR MASS BUILDING IN FROM THE GREAT LAKES REGION AND OHIO VALLEY.
H850 TEMPS FALL TO +2C TO +5C ACCORDING THE LATEST GFS THU NIGHT.
MAX TEMPS WILL RANGE FROM THE U50S TO M60S OVER THE SRN DACKS TO
LOWER TO M70S FROM THE CAPITAL REGION SOUTH AND EAST.  LOWS WILL BE
IN THE 40S WITH SOME 30S OVER THE DACKS.  FRIDAY WILL FEATURE LOTS
OF SUNSHINE AND TEMPS ABOUT 5-7 DEGREES BELOW NORMAL WITH MID AND
U60S OVER THE HILLS AND MTNS...AND L70S IN THE VALLEYS.

FRI NIGHT-SAT...THE SFC HIGH MOVES SOUTH AND EAST OF THE
REGION...AS A WARM FRONT BRIEFLY LIFTS THROUGH WITH LITTLE IF ANY
PCPN. LOWS WILL STILL BE IN THE M40S TO M50S. A COLD FRONT SLIDES
S/SE FROM SRN ONTARIO AND SWERN QUEBEC.  THE BEST CHC FOR SHOWERS
WILL BE FROM THE CAPITAL REGION NORTH AND WEST DURING THE DAY...AND
SLIGHT CHC VALUES TO THE SOUTH AND EAST. THE CONVERGENCE WITH THIS
BOUNDARY IS NOT VERY STRONG.

SATURDAY NIGHT INTO SUNDAY...THE COLD FRONT SINKS SOUTH OF THE FCST
AREA WITH A REINFORCING SURGE OF COOL...CANADIAN AIR. A SLIGHT TO
LOW CHC OF SHOWERS LINGERS INTO SUNDAY MORNING.  A BROAD ANTICYCLONE
SETTLES OVER NY AND NEW ENGLAND TO CLOSE THE WEEKEND AND OPEN NEXT
WEEK. TEMPS WILL FINISH NEAR SEASONABLE NORMALS.

OVERALL...PCPN LOOKS BELOW NORMAL WITH TEMPS SLIGHTLY BELOW NORMAL
IN THE LONG TERM.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
A STRONG UPPER LEVEL LOW AND SURFACE COLD FRONT WILL APPROACH FROM
SOUTHEAST ONTARIO AND SOUTHWEST QUEBEC INTO THIS EVENING...BRINGING
PERIODS OF SHOWERS AND THUNDERSTORMS TO THE TERMINALS.

CONDITIONS ARE MAINLY VFR EARLY THIS AFTERNOON...BUT WITHIN ANY
SHRA/TSRA OCCASIONAL MVFR AND EVEN BRIEF IFR CONDITIONS WILL BE
LIKELY. WITH AT LEAST SCATTERED COVERAGE OF CONVECTION...THERE IS
ENOUGH CONFIDENCE TO MENTION TSRA IN TEMPOS FOR 3-4 HOURS FROM MID
AFTERNOON INTO THE EVENING. HIGHEST PROBABILITY FOR A TSRA IMPACTING
A SPECIFIC TERMINAL IS KPOU...SO WILL MENTION IFR CONDITIONS IN THE
TEMPO THERE.

OTHERWISE...CONVECTION SHOULD DECREASE THIS EVENING AND ESPECIALLY
AFTER DARK WITH LOSS OF INSTABILITY AND THE FRONTAL BOUNDARY MOVING
ACROSS THE AREA. HOWEVER...THERE WILL BE PLENTY OF RESIDUAL
LOW-LEVEL MOISTURE...SO LOW STRATUS AND/OR SOME FOG FORMATION IS
LIKELY. MVFR/IFR CONDITIONS POSSIBLE...WITH THE GREATEST LIKELIHOOD
FOR IFR AT KGFL/KPSF.

VFR CONDITIONS SHOULD RETURN BY LATE TUESDAY MORNING...AS A DRIER
NORTHWEST FLOW DEVELOPS ACROSS THE REGION. THERE IS THE RISK FOR AN
ISOLATED SHOWER AS THE UPPER LEVEL TROUGH AXIS PASSES THROUGH...BUT
COVERAGE IS TOO LOW TO MENTION IN TAFS AT THIS TIME.

SURFACE WINDS WILL BE SOUTHERLY AROUND 5 TO 7 KT INTO THE
EVENING...THEN BECOMING LIGHT AND VARIABLE. WINDS WILL SHIFT TO THE
NORTHWEST AND INCREASE TO AROUND 5 TO 10 KT TUESDAY MORNING. WINDS
WILL BE GUSTY AND ERRATIC IN AND NEAR ANY THUNDERSTORMS.

OUTLOOK...
TUESDAY NIGHT TO FRIDAY: NO OPERATIONAL IMPACT.  NO SIG WX.

&&

.FIRE WEATHER...
WARM...HUMID AND WET WEATHER WILL CONTINUE TODAY. A DRIER AIRMASS
WILL BE USHERED IN LATE TONIGHT INTO TUESDAY AS COLD FRONT MOVES
ACROSS THE REGION.

&&

.HYDROLOGY...
PRECIPITABLE WATER VALUES ARE HIGH CLOSE TO 2 INCHES SO VERY HEAVY
DOWNPOURS WILL OCCUR WITH SOME STORMS. WINDS WILL REMAIN LIGHT
RESULTING IN SLOW MOVEMENT OF THE STORMS.

HAVE DECIDED TO ISSUE A FLASH FLOOD WATCH FOR THE TACONICS...THE
BERKSHIRES...LITCHFIELD COUNTY AND SOUTHERN VERMONT VALID INTO EARLY
THIS EVENING. PORTIONS OF THIS AREA RECEIVED HEAVY RAINFALL SUNDAY
AND AGAIN OVERNIGHT/EARLY THIS MORNING MAKING THEM MORE VULNERABLE
TO FLASH FLOODING. HOWEVER....WE CAN NOT RULE OUT THE POSSIBILITY
FOR ISOLATED FLASH FLOODING ACROSS EAST CENTRAL NEW YORK TODAY BUT
FORECAST CONFIDENCE IS NOT HIGH ENOUGH TO WARRANT A WATCH AT THIS
TIME.

A DRIER AIRMASS WILL FINALLY BE USHERED INTO THE REGION LATE
TONIGHT AND TUESDAY AS COLD FRONT MOVES ACROSS THE REGION.

WIDESPREAD PRECIPITATION IS NOT EXPECTED THIS WEEK AS HIGH PRESSURE
WILL DOMINATE MUCH OF THE TIME. HOWEVER...THERE WILL BE A COUPLE/FEW
FRONTAL PASSAGES WHICH WILL BRING THE THREAT OF SHOWERS TO THE AREA.

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...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR CTZ001-013.
NY...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NYZ054-061-
     066.
MA...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR MAZ001-025.
VT...FLASH FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR VTZ013>015.

&&

$$
SYNOPSIS...IAA
NEAR TERM...IAA/JPV
SHORT TERM...IAA
LONG TERM...WASULA
AVIATION...JPV
FIRE WEATHER...IAA
HYDROLOGY...IAA/WASULA








AREA FORECAST DISCUSSION

NWS MIAMI FL

 1215 PM EDT MON SEP 2 2013

..HIGH LIGHTNING RISK THIS AFTERNOON; STREET FLOODING POSSIBLE...

.UPDATE...THUNDERSTORMS WITH A LOT OF LIGHTNING ARE ONGOING ACROSS
SW FLORIDA. WE EXPECT QUICK TSTORM DEVELOPMENT ACROSS THE REST OF
THE INTERIOR AND SOUTHEAST FLORIDA OVER THE NEXT HOUR. LIGHTNING
IS A HIGH RISK TODAY. ALSO, THUNDERSTORMS WILL BE SLOW MOVING AND
PRODUCING TORRENTIAL RAINFALL. HRRR SHOWS SOME LOCALES ACROSS SE
FLORIDA PICKING UP OVER 4" OF RAIN THIS AFTERNOON. THIS SEEMS
PLAUSIBLE GIVEN THE ACTIVE WEATHER EXPECTED AND SLOW STORM
MOVEMENT. PRODUCTS WERE UPDATED ACCORDINGLY WITH THIS POTENTIAL
REFLECTED. /GREGORIA

&&

.PREV DISCUSSION... /ISSUED 1104 AM EDT MON SEP 2 2013/

UPDATE...A STORMY LABOR DAY AFTERNOON IS EXPECTED. THE MIAMI
SOUNDING SHOWS A MOIST/UNSTABLE ATMOSPHERE WITH A PWAT OF 1.94
INCHES. LAPSE RATES AREN`T AS STEEP AS THEY WERE YESTERDAY WITH
WARMING ALOFT. THE H5 TEMP HAS WARMED BY ALMOST 2C SINCE
YESTERDAY. HOWEVER, ALREADY CONVECTION IS FIRING UP ALONG THE GULF
COAST SEA BREEZE. ONCE THIS MOVES INLAND AND THE ATLANTIC SEA
BREEZE DEVELOPS, THUNDERSTORMS WILL BECOME MORE WIDESPREAD ACROSS
THE INTERIOR AND EAST COAST. MAY NEED TO INCREASE POPS EVEN MORE.
IF LATEST HRRR IS RIGHT, WIDESPREAD ACTIVITY WOULD DEVELOP. THE
MAIN IMPACTS TODAY WITH THE STORMS WILL BE FREQUENT LIGHTNING
STRIKES AND HEAVY RAIN/POTENTIAL ISOLATED STREET FLOODING DUE TO
SLOW STORM MOTION. THERE IS A LESSER RISK OF STRONG WIND GUSTS
THIS AFTERNOON COMPARED TO YESTERDAY, BUT STILL PRESENT. /GREGORIA

PREV DISCUSSION... /ISSUED 827 AM EDT MON SEP 2 2013/

UPDATE...ACARS DATA SHOWS A SW-W LIGHT STEERING FLOW THROUGH THE
COLUMN. GPS MET DATA SHOWS PWATS IN THE 1.75-1.90 INCH RANGE
ACROSS SOUTH FL. THERE HAS BEEN LITTLE ENVIRONMENTAL CHANGES SINCE
YESTERDAY, SO HAVE INCREASED POPS WITH AN ORIENTATION FAVORING THE
INTERIOR AND EAST COAST...GIVEN THE AFOREMENTIONED STEERING FLOW.
NUMEROUS ACTIVITY HAS DEVELOPED OVER THE PAST FEW DAYS AND SEE NO
REASON TO DEVIATE FROM THIS TODAY WITH NUMEROUS THUNDERSTORMS
DEVELOPING INTERIOR AND ACROSS THE EAST COAST METROPOLITAN AREAS
JUST INLAND FROM THE COAST. /GREGORIA

PREV DISCUSSION... /ISSUED 730 AM EDT MON SEP 2 2013/

AVIATION...
MAINLY VFR CONDITIONS SHOULD PREVAIL. LIGHT AND VARIABLE WINDS
THIS MORNING WILL BECOME EASTERLY AT 5-10 KNOTS THIS AFTERNOON.
CONDITIONS ARE SIMILAR TO YESTERDAY...SO KEPT VCTS AFTER 16Z FOR
THE EAST COAST TERMINALS...EXCEPT KPBI. A FEW SHOWERS WERE NEAR
KAPF THIS MORNING...BUT THESE WILL DISSIPATE OVER THE NEXT COUPLE
OF HOURS. THE GULF COAST SEA BREEZE IS EXPECTED TO DEVELOP BY
EARLY AFTERNOON...AND SHOWERS AND STORMS SHOULD MOVE EAST OF KAPF.
SHOWERS AND STORMS ARE FORECAST TO DIMINISH IN THE EARLY
EVENING...WITH LIGHT AND VARIABLE WINDS AGAIN OVERNIGHT.

PREV DISCUSSION... /ISSUED 359 AM EDT MON SEP 2 2013/

DISCUSSION...
NO MAJOR SYNOPTIC SCALE CHANGES EXPECTED ACROSS SOUTH FLORIDA
THROUGH THE WEEK.

FLOW IS EXPECTED TO BE LIGHT THROUGH THE FIRST HALF OF THE WEEK AS
MID LEVEL RIDGING BUILDS ACROSS THE FLORIDA PENINSULA FROM THE
ATLANTIC. THIS SHOULD ALLOW FOR SEA BREEZE/OUTFLOW BOUNDARY
INTERACTIONS TO INDUCE AFTERNOON AND EARLY EVENING SHOWER AND
THUNDERSTORMS MAINLY ACROSS THE INTERIOR AND GULF COASTAL AREAS.
HOWEVER THE RIDGING SHOULD ALSO KEEP THE MID LEVELS OF THE
ATMOSPHERE WEAKLY CAPPED AND IS DEPICTED IN MODEL SOUNDINGS. THIS
SHOULD INHIBIT DEEP VERTICAL DEVELOPMENT OF AFTERNOON
THUNDERSTORMS. HEAT INDEX VALUES ARE ALSO EXPECTED TO BE ON THE
RISE THROUGH MIDWEEK AS A RESULT OF THE STRONGER RIDGING. BY
WEDNESDAY...MAXIMUM HEAT INDEX VALUES SHOULD BE AROUND 100 DEGREES
ACROSS THE EAST COAST METRO AREAS AND BETWEEN 105 AND 109 DEGREES
ACROSS INTERIOR COLLIER COUNTY.

EASTERLY FLOW SHOULD PREVAIL AGAIN BY THURSDAY AND REMAIN THROUGH
THE END OF THE WEEK. AT THIS TIME THE FLOW DOES NOT APPEAR TO BE
STRONG ENOUGH TO COUNTERACT THE DEVELOPMENT OF A GULF COAST SEA
BREEZE. THIS SHOULD KEEP MOST OF THE AFTERNOON CONVECTION TO MAINLY
THE INTERIOR AND GULF COAST.

THERE IS CURRENTLY A DISORGANIZED AREA OF CONVECTION ACROSS THE
LESSER ANTILLES THAT THE NATIONAL HURRICANE CENTER GIVES A 40
PERCENT CHANCE OF DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT
48 HOURS AND A 50 PERCENT CHANCE DURING THE NEXT 5 DAYS. IT IS
CURRENTLY MOVING WEST-NORTHWEST AT ABOUT 10 MPH. CURRENT OPERATIONAL
MODELS BRING THIS SYSTEM ACROSS HISPANIOLA AS AN OPEN WAVE LATE IN
THE WEEK AND INTO THE WEEKEND.

AVIATION...
VFR CONDITIONS EXPECTED. VCTS ADDED AT AROUND 16-18Z AT ALL
TERMINALS. EASTERLY FLOW WILL PREVAIL ACROSS THE AREA...SLIGHTLY
INCREASING IN SPEED IN THE AFTERNOON. CURRENT GUIDANCE KEEPS
DEPICTING VCTS AFTER 18Z AT ALL TERMINALS...AND DUE TO SIMILAR
WEATHER CONDITIONS THAN PREVIOUS DAYS...WILL EXPECT THIS ACTIVITY
TO FORM. WEST COAST SEA BREEZE EXPECTED TO PUSH INLAND BY
16Z...WHICH WILL ALSO HELP IN THE DEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THROUGH THE AFTERNOON AND EVENING. ALL ACTIVITY WILL
POSSIBLY DISSIPATE BY 00Z.

MARINE...
GENERALLY EAST TO SOUTHEAST WINDS AT LESS THAN 10 KNOTS WILL
PREVAIL ACROSS THE ATLANTIC WATERS THROUGH MIDWEEK WITH
CORRESPONDING SEAS AT 2 FEET OR LESS. FLOW IS EXPECTED TO BECOME
EASTERLY AND INCREASE SLIGHTLY THROUGH THE LATTER HALF OF THE WEEK
WITH SEAS ONLY IN THE 1 TO 3 FOOT RANGE.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  89  77  89  78 / 80 50 30 20
FORT LAUDERDALE  89  79  90  80 / 60 50 30 20
MIAMI            91  78  90  79 / 80 50 30 20
NAPLES           89  75  90  77 / 60 40 40 20

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$






AREA FORECAST DISCUSSION

NWS JACKSON KY

 605 PM EDT MON SEP 2 2013

.UPDATE...
ISSUED AT 605 PM EDT MON SEP 2 2013

UPDATED THE FORECAST TO BETTER REFLECT CURRENT CONDITIONS AND MODEL
TRENDS. INCREASED THE CHANCES OF PRECIPITATION 10-20 PERCENT BASED
ON WHAT WAS SHOWING UP ON THE RADAR AND THE OUTPUT FROM THE RAPID
REFRESH MODEL. ALSO HAVE THE PRECIPITATION ENDING TONIGHT AND NOT
EXTEND INTO TUESDAY. THE NAM BUFR WAS SHOWING A DECREASE IN MID LEVEL
MOISTURE AND INCREASED CAPPING STARTING TO OCCUR OVER THE NEXT FEW
HOURS. THIS SHOULD HELP THE LOW THE THREAT FOR STRONG TO SEVERE
THUNDERSTORMS BY 8 PM. THE REST OF THE FORECAST IS ON TRACK.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 338 PM EDT MON SEP 2 2013

ISOLATED SHOWERS AND THUNDERSTORMS WERE AFFECTING THE AREA AT MID
AFTERNOON. THEY WERE INCREASING IN COVERAGE ALONG A LINE FROM
LOUISVILLE KY TO ZANESVILLE OH...ALONG AND AHEAD OF A COLD FRONT.
HAVE FOLLOWED THE FORECAST OF THE HRRR MODEL THROUGH THIS EVENING...
SHOWING THE GREATEST CONCENTRATION OF CONVECTION ALONG AND JUST AHEAD
OF THE COLD FRONT AS IT MOVES SE...WITH A BIT OF A DROP OFF IN
ACTIVITY AFTER NIGHTFALL. THIS PLACES HIGHEST POPS IN OUR NW COUNTIES
DURING THE LATE AFTERNOON AND EARLY EVENING. HAVE KEPT THEM IN THE
HIGH CHANCE RANGE THERE...AND USED POPS LOWER IN THE CHANCE RANGE
DURING THE NIGHT AS THE FRONT MOVES FURTHER SE. A FEW STRAGGLING
SHOWERS COULD BE LINGERING NEAR THE VA BORDER ON TUESDAY MORNING AS
THE FRONT LEAVES. HIGH PRESSURE BUILDING IN FROM THE NW BEHIND THE
FRONT WILL BRING IN A DRIER AIR MASS...WITH SKIES BECOMING MOSTLY
CLEAR FROM NW TO SE LATE TONIGHT AND TUESDAY AND PERSISTING THROUGH
TUESDAY NIGHT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 PM EDT MON SEP 2 2013

THE UPPER LEVEL PATTERN WILL START OFF AMPLIFIED WITH A LARGE RIDGE
CENTERED ACROSS THE ROCKIES...AN UPPER LOW CENTERED OFF THE PACIFIC
NORTHWEST COAST...AND DEEP TROUGHING EXTENDED FROM EASTERN CANADA
DOWN THROUGH NEW ENGLAND. THE MODELS ARE IN GOOD AGREEMENT...WITH A
GRADUAL DAMPENING TO TAKE PLACE IN GENERAL ACROSS THE WESTERN HALF
OF THE CONUS AS THE PACIFIC NORTHWEST UPPER LOW ADVANCES EAST ON THE
NORTHERN PERIPHERY OF THE RIDGE...WEAKENING BOTH FEATURES IN THE
PROCESS. THE TROUGHING TO THE EAST WILL BE SLOWER TO PULL OUT UNTIL
THE ROCKIES RIDGE SLIDES EAST INTO THE MISSISSIPPI VALLEY BY THE END
OF THE WEEK AND INTO EARLY NEXT WEEK.

ALL OF THIS WILL RESULT IN AN EXTENDED PERIOD OF GENERALLY DRY
WEATHER ACROSS EASTERN KENTUCKY...WITH SURFACE HIGH PRESSURE
REMAINING PARKED ACROSS THE AREA THROUGH FRIDAY...BEFORE IT BECOMES
MORE CONGEALED OFF OF THE THE EASTERN SEABOARD FOR THE WEEKEND AND
EARLY NEXT WEEK. ENOUGH MOISTURE MAY THEN RETURN TO JUSTIFY HANGING
ONTO SOME SLIGHT CHANCE POPS ALONG THE SOUTHEAST TERRAIN SATURDAY
THROUGH MONDAY.

FOR TEMPERATURES...LOWS WILL START OUT IN THE 50S THROUGH THE END OF
THE WORK WEEK...WITH HIGHS MAINLY IN THE LOW TO MID 80S. WARMER AND
MORE HUMID AIR WILL THEN GRADUALLY INCREASE ACROSS THE
AREA...ALTHOUGH PEAK DEW POINTS IN THE AFTERNOON LOOK TO HOLD IN THE
LOW TO MID 60S...SO NOT AS BALMY AS WHAT WE HAVE BEEN ACCUSTOMED TO
OVER THE PAST SEVERAL DAYS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 605 PM EDT MON SEP 2 2013

LOCALIZED MVFR POSSIBLE WITH SHOWERS AND THUNDERSTORMS MOVING ACROSS
THE AREA AHEAD OF AND ALONG WITH THE FRONT. SOME TEMPO IFR IS ALSO
POSSIBLE WITH THE HEAVIEST OF THE STORMS. SHOWERS WILL DIE OUT
OVERNIGHT AFTER A COLD FRONT PASSES. THE GREATEST UNCERTAINTY IS WITH
THE FOG DEVELOPMENT TONIGHT. THERE IS SOME DRY AIR BEHIND THE
FRONT...HOWEVER THE ATMOSPHERE MAY BE ABLE TO DECOUPLE BEFORE THE DRY
AIR MIXES DOWN TO THE SURFACE. ANOTHER VARIABLE IS HOW MUCH RAIN IS
GOING TO FALL AS THE FRONT PASSES. THE MORE RAIN...THE GREATER THE
CHANCE FOR SEEING SOME VFR. WILL BE STAYING WITH MVFR WITH THE
PASSING SHOWERS AND NEAR DAWN WITH THE MIST. AFTER 13Z...IT SHOULD BE
VFR FOR QUITE A WHILE.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...JJ
SHORT TERM...HAL
LONG TERM...GEOGERIAN
AVIATION...JJ








AREA FORECAST DISCUSSION

NWS JACKSON KY

 338 PM EDT MON SEP 2 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 338 PM EDT MON SEP 2 2013

ISOLATED SHOWERS AND THUNDERSTORMS WERE AFFECTING THE AREA AT MID
AFTERNOON. THEY WERE INCREASING IN COVERAGE ALONG A LINE FROM
LOUISVILLE KY TO ZANESVILLE OH...ALONG AND AHEAD OF A COLD FRONT.
HAVE FOLLOWED THE FORECAST OF THE HRRR MODEL THROUGH THIS EVENING...
SHOWING THE GREATEST CONCENTRATION OF CONVECTION ALONG AND JUST AHEAD
OF THE COLD FRONT AS IT MOVES SE...WITH A BIT OF A DROP OFF IN
ACTIVITY AFTER NIGHTFALL. THIS PLACES HIGHEST POPS IN OUR NW COUNTIES
DURING THE LATE AFTERNOON AND EARLY EVENING. HAVE KEPT THEM IN THE
HIGH CHANCE RANGE THERE...AND USED POPS LOWER IN THE CHANCE RANGE
DURING THE NIGHT AS THE FRONT MOVES FURTHER SE. A FEW STRAGGLING
SHOWERS COULD BE LINGERING NEAR THE VA BORDER ON TUESDAY MORNING AS
THE FRONT LEAVES. HIGH PRESSURE BUILDING IN FROM THE NW BEHIND THE
FRONT WILL BRING IN A DRIER AIR MASS...WITH SKIES BECOMING MOSTLY
CLEAR FROM NW TO SE LATE TONIGHT AND TUESDAY AND PERSISTING THROUGH
TUESDAY NIGHT.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 338 PM EDT MON SEP 2 2013

THE UPPER LEVEL PATTERN WILL START OFF AMPLIFIED WITH A LARGE RIDGE
CENTERED ACROSS THE ROCKIES...AN UPPER LOW CENTERED OFF THE PACIFIC
NORTHWEST COAST...AND DEEP TROUGHING EXTENDED FROM EASTERN CANADA
DOWN THROUGH NEW ENGLAND. THE MODELS ARE IN GOOD AGREEMENT...WITH A
GRADUAL DAMPENING TO TAKE PLACE IN GENERAL ACROSS THE WESTERN HALF
OF THE CONUS AS THE PACIFIC NORTHWEST UPPER LOW ADVANCES EAST ON THE
NORTHERN PERIPHERY OF THE RIDGE...WEAKENING BOTH FEATURES IN THE
PROCESS. THE TROUGHING TO THE EAST WILL BE SLOWER TO PULL OUT UNTIL
THE ROCKIES RIDGE SLIDES EAST INTO THE MISSISSIPPI VALLEY BY THE END
OF THE WEEK AND INTO EARLY NEXT WEEK.

ALL OF THIS WILL RESULT IN AN EXTENDED PERIOD OF GENERALLY DRY
WEATHER ACROSS EASTERN KENTUCKY...WITH SURFACE HIGH PRESSURE
REMAINING PARKED ACROSS THE AREA THROUGH FRIDAY...BEFORE IT BECOMES
MORE CONGEALED OFF OF THE THE EASTERN SEABOARD FOR THE WEEKEND AND
EARLY NEXT WEEK. ENOUGH MOISTURE MAY THEN RETURN TO JUSTIFY HANGING
ONTO SOME SLIGHT CHANCE POPS ALONG THE SOUTHEAST TERRAIN SATURDAY
THROUGH MONDAY.

FOR TEMPERATURES...LOWS WILL START OUT IN THE 50S THROUGH THE END OF
THE WORK WEEK...WITH HIGHS MAINLY IN THE LOW TO MID 80S. WARMER AND
MORE HUMID AIR WILL THEN GRADUALLY INCREASE ACROSS THE
AREA...ALTHOUGH PEAK DEW POINTS IN THE AFTERNOON LOOK TO HOLD IN THE
LOW TO MID 60S...SO NOT AS BALMY AS WHAT WE HAVE BEEN ACCUSTOMED TO
OVER THE PAST SEVERAL DAYS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 217 PM EDT MON SEP 2 2013

LOCALIZED MVFR DUE MAINLY TO CEILINGS WAS PRESENT AT THE START OF THE
PERIOD...BUT ONGOING OVERALL IMPROVEMENT WAS OCCURRING. MOSTLY VFR
PREVAILED. ISOLATED SHOWERS WERE DEVELOPING AND WILL PERSIST THROUGH
THE AFTERNOON...BRINGING VERY LOCALIZED RESTRICTIONS. A FEW OF THEM
MAY GROW TALL ENOUGH TO PRODUCE LIGHTNING. SHOWERS WILL DIE OUT
OVERNIGHT AFTER A COLD FRONT PASSES. FOG IS EXPECTED TO DEVELOP
OVERNIGHT...EVENTUALLY BRINGING WIDESPREAD IFR. FOG AND LOW CLOUDS
WILL LIFT AND DISSIPATE ON TUESDAY MORNING...LEAVING VFR BY THE END
OF THE PERIOD.


&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...HAL
LONG TERM...GEOGERIAN
AVIATION...HAL







AREA FORECAST DISCUSSION

NWS JACKSON KY

 217 PM EDT MON SEP 2 2013

.UPDATE...
ISSUED AT 217 PM EDT MON SEP 2 2013

UPDATED FORECAST GRIDS BASED ON OBSERVED TRENDS...WITH LITTLE IMPACT
ON THE OVERALL FORECAST.

UPDATE ISSUED AT 1108 AM EDT MON SEP 2 2013

LOW CLOUDS DEVELOPED AND BECAME MUCH MORE PREVALENT THIS MORNING THAN
WAS FORECAST. THIS SLOWED THE WARM-UP A BIT AND WILL DELAY DEVELOPMENT
OF SURFACE BASED DEEP CONVECTION.

UPDATE ISSUED AT 730 AM EDT MON SEP 2 2013

RAN A DATA LOAD AND BLEND TO MATCH UP THE CURRENT OBS AND TRENDS WITH
THE GRIDS. OTHERWISE...THE FORECAST IS ON TRACK AND UPDATES HAVE BEEN
SENT TO THE NDFD/WEB SERVERS.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 350 AM EDT MON SEP 2 2013

07Z SFC ANALYSIS SHOWS LOW PRESSURE MOVING THROUGH THE OHIO VALLEY
WITH A COLD FRONT PRESSING INTO KENTUCKY FROM THE NORTHWEST. ON THE
OTHER SIDE OF THAT BOUNDARY COOLER AND MUCH DRIER AIR IS FOUND. EAST
KENTUCKY IS ON THE OPPOSITE SIDE GIVING US ANOTHER MUGGY AND MILD
NIGHT WITH TEMPS AND DEW POINTS WITHIN A FEW DEGREES OF 70. PLENTY OF
LOW LEVEL MOISTURE IS KEEPING SOME LOW LEVEL CLOUDS AROUND IN
ADDITION TO SUPPORTING THE DEVELOPMENT OF PATCHY VALLEY FOG...BUT THE
CONVECTION HAS REMAINED AT BAY.

THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM. THEY
ALL TAKE A DECENT...FOR LATE SUMMER...TROUGH THROUGH THE GREAT LAKES
AND OHIO VALLEY FROM TODAY INTO TUESDAY. THIS WILL SUPPORT LOW
HEIGHTS AND SHORT WAVE ENERGY PASSING THROUGH THE REGION TODAY AND
TONIGHT. THE TROUGH AXIS DOES GO THROUGH EAST KENTUCKY BY TUESDAY
MORNING...THOUGH...AND THIS WILL BE FOLLOWED BY RISING HEIGHTS IN
THE WAKE OF THE TROUGH. THE MESOSCALE WILL STILL DOMINATE OUR WEATHER
WITH DIFFERENTIAL HEATING AND OUTFLOW BOUNDARIES HELPING TO DRIVE THE
CONVECTION AHEAD OF THE COLD FRONT THAT WILL PUSH THROUGH EAST
KENTUCKY LATER TONIGHT. ACCORDINGLY...HAVE LEANED TOWARD THE HIGHER
RESOLUTION NAM12 FOR WEATHER DETAILS...BUT MORE BROAD BRUSHED WITH
THE SPECIFICS...ALONG WITH USING THE HRRR FOR THE NEAR TERM.

SENSIBLE WEATHER WILL FEATURE A RECHARGING OF THE AIR MASS OVER EAST
KENTUCKY TODAY WITH BUILDING INSTABILITY AHEAD OF THAT FRONT. THIS
SHOULD YIELD SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE AREA BY
MID AFTERNOON. GRADUALLY THE CONVECTION WILL SHRINK SOUTHEAST DURING
THE EVENING HOURS AS THE FRONT PUSHES THE DEEPER MOISTURE OUT OF THE
AREA. AS A RESULT...HAVE MAXED OUT POPS NEAR 00Z FOR THE AREA WITH A
TAPERING FROM NORTHWEST TO SOUTHEAST THEREAFTER. COOLER AIR FILTERING
INTO THE STATE IN THE WAKE OF THE FRONT WILL LEAD TO LOWER TEMPS IN
THE NORTHWEST PARTS OF THE CWA BY TUESDAY MORNING...THOUGH MUGGY
VALUES WILL REMAIN TO THE SOUTH AND EAST. DRIER AIR TAKES OVER ON
TUESDAY BRINGING A NICE CHANGE...MAKING FOR A PLEASANTLY DRY AND
COOLER DAY.

AGAIN USED THE CONSSHORT AND ITS BC VERSION FOR A STARTING POINT WITH
THE DEW POINT AND WIND GRIDS...RESPECTIVELY...UNTIL 00Z TUESDAY...
FOLLOWED THE CONSALL FOR THE REST. FOR TEMPS...ADJUSTED THE CONSALL
FOR SOME MINOR TERRAIN ENHANCEMENTS IN THE LOWS TONIGHT WITH THE
HOURLY DIURNAL CURVE DERIVED FROM THE NAM12. AS FOR POPS...ENDED UP
CLOSER TO THE WETTER MAV GUIDANCE TODAY...AND SIMILAR TO BOTH
TONIGHT...THEN DRY ON TUESDAY.

.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 AM EDT MON SEP 2 2013

NOT A LOT OF CHANGE FOR THE EXTENDED PERIOD. TUESDAY NIGHT/WEDNESDAY
SHOULD BEGIN WITH UPPER LEVEL TROUGHING AND SURFACE HIGH PRESSURE IN
PLACE WITH LIGHT WINDS. THE ONLY MOISTURE AVAILABLE IN THE
ATMOSPHERE WILL BE IN THE UPPER LEVELS WEDNESDAY AFTERNOON...WITH
ABUNDANT DRYING BELOW. AS A RESULT...SOME CIRRUS CLOUDS WILL BE
PRESENT...BUT OTHERWISE WEATHER WILL BE QUITE BENIGN. COOLER AND
DRIER AIR FLOWING IN FROM CANADA WILL KEEP HIGH TEMPS AND HUMIDITY
AT BAY.

FOR THURSDAY...MUCH OF THE SAME IS EXPECTED THROUGH THE FIRST HALF
OF THE DAY. THEN...AS WAS MENTIONED IN PREVIOUS FORECAST...AN
IMPULSE DROPPING INTO A LARGE UPPER TROUGH OVER THE NE CONUS AND SE
CANADA WILL SEND ANOTHER COLD FRONT SOUTH TOWARD THE LOCAL AREA
THURSDAY AFTERNOON OR THURSDAY NIGHT. HOWEVER... VIRTUALLY NO LOW
LEVEL MOISTURE RETURN IS EXPECTED...AND THE FRONT SHOULD BE DYING
OUT AS IT APPROACHES...WITH ALMOST NO IMPACT ON OUR LOCAL
WEATHER. AS THE FRONT DIES...HIGH PRESSURE DROPPING IN BEHIND IT
WILL MERGE WITH HIGH PRESSURE ORIGINALLY TO THE SOUTH OF THE
FRONT...WITH THE LOCAL RESULT BEING DRY WEATHER UNDER ITS DOMINANCE
THROUGH AT LEAST FRIDAY NIGHT.

A WEAK DISTURBANCE WILL TRY TO MOVE THROUGH THE OHIO VALLEY AND ERN
KY LATE IN THE WEEKEND. HOWEVER AT THIS POINT...LATEST GFS SOUNDINGS
ARE STILL LOOKING RATHER LACKLUSTER FOR ANY WIDESPREAD PRECIP
CHANCES. THE GFS IS STILL TRYING TO PINPOINT SOME AFTERNOON
CONVECTION OVER THE HIGHER APPALACHIAN TERRAIN THROUGH THE
WEEKEND...REACHING INTO THE FAR SE COALFIELDS OF KY. THE ECMWF HAS
THE SAME IDEA...BUT CONTINUES TO KEEP ALL PRECIP CHANCES TO OUR SE
OVER THE HIGHER APPALACHIAN TERRAIN. ALL THINGS CONSIDERED...WITH
LITTLE AGREEMENT OR SYNOPTIC SUPPORT...WILL CONTINUE WITH ONLY
SLIGHT CHANCE POPS AT BEST FOR THE FAR SE COUNTIES DURING THE
WEEKEND. ELSEWHERE...THE RETURN OF MORE SRLY FLOW WILL ALLOW
TEMPERATURES TO INCREASE SLIGHTLY THROUGHOUT THE WEEKEND...REACHING
THE MID AND UPPER 80S. HUMIDITY VALUES ON THE OTHER HAND WILL REMAIN
AT BAY...KEEPING CONDITIONS WARM BUT PLEASANT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 217 PM EDT MON SEP 2 2013

LOCALIZED MVFR DUE MAINLY TO CEILINGS WAS PRESENT AT THE START OF THE
PERIOD...BUT ONGOING OVERALL IMPROVEMENT WAS OCCURRING. MOSTLY VFR
PREVAILED. ISOLATED SHOWERS WERE DEVELOPING AND WILL PERSIST THROUGH
THE AFTERNOON...BRINGING VERY LOCALIZED RESTRICTIONS. A FEW OF THEM
MAY GROW TALL ENOUGH TO PRODUCE LIGHTNING. SHOWERS WILL DIE OUT
OVERNIGHT AFTER A COLD FRONT PASSES. FOG IS EXPECTED TO DEVELOP
OVERNIGHT...EVENTUALLY BRINGING WIDEPSREAD IFR. FOG AND LOW CLOUDS
WILL LIFT AND DISSIPATE ON TUESDAY MORNING...LEAVING VFR BY THE END
OF THE PERIOD.

&&

.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...JMW
AVIATION...HAL







AREA FORECAST DISCUSSION

NWS PADUCAH KY

 1239 PM CDT Mon Sep 2 2013

.UPDATE...
ISSUED AT 1239 PM CDT MON SEP 2 2013

The aviation section has been updated for the 18Z TAF issuance.

&&

.SHORT TERM...(Today through Wednesday)
ISSUED AT 345 AM CDT MON SEP 2 2013

Cold front early this a.m. was approaching the NW part of our CWFA.
Near calm and saturated surface conditions allowing for areas of
fog especially SRN IL / SEMO where temps crossed over and are in the
upper 60s. Nothing on radar to speak of. Will keep conditions
convection free through the early morning hours. By 15-16z, the
NAM and HRRR drop the front to about the Ohio River with
instability developing ahead of it. Cannot rule out isolated
convection along and ahead of the front mainly over WKY late
morning through the afternoon, given the weak convergence, slight
steepening of mid level lapse rates and modest surface based
instability. Should anything get going, that chance will shift
south and east through late afternoon, followed by a gradual
lowering of humidity from the NW in the wake of the front.

Quiet, cooler weather tonight through Wednesday as high pressure
takes control and builds southward. For temps we used a blend of
MOS and bias corrected model input.

.LONG TERM...(Wednesday night through Monday)
ISSUED AT 345 AM CDT MON SEP 2 2013

At this time, the extended forecast period is a dry forecast.  A
westward tilted ridge of high pressure with height persists over the
WFO PAH forecast area, with scant low level moisture available. The
only "ripple" in the forecast late next Sunday into Sunday night,
when there is a slightly troughiness that develops along the east
side of the mid-upper level ridge. However, given that this is such
a low PoP event in the first place, confidence is pretty low for any
measurable precipitation.

With northwest flow aloft east of the upper ridge and little in the
way of any significant changes in thickness values, kept
temperatures in the middle 80s to around 90 for nearly all of the
forecast period.

&&

.AVIATION...
ISSUED AT 1239 PM CDT MON SEP 2 2013

The cold front is dragging its heels across the area and waslocated
near the Ohio River from KPAH to KEVV at 17Z. The front will make
gradual progress through the afternoon with a west northwest wind
developing at all sites by 21Z. Near and ahead of the front a
thick cu field has developed with some MVFR ceilings possible at
all sites except KCGI for the next hour or two. The MVFR ceilings
should lift/scatter once the front moves through a given area.

For tonight, dry and cool surface high pressure will build across
the region, which should prevent fog development. Some lower VFR
ceilings will be possible through the night, especially at KEVV
and KOWB. A modest north northeast wind will mix down throughout
the area by mid-morning Tuesday. There is some signal for a thick
cu field to develop in the east on Tuesday, but any ceilings
should be VFR.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&

$$

UPDATE...DRS
AVIATION...DRS







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 427 PM EDT MON SEP 2 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 317 PM EDT MON SEP 2 2013

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CONFLUENT NW FLOW
ALF OVER THE UPR GRT LKS TO THE W OF DEPARTING VIGOROUS SHRTWV
MOVING INTO QUEBEC AND E OF SLOWLY PROGRESSIVE UPR RDG IN THE
PLAINS. WITH LINGERING LLVL MSTR SHOWN ON THE 12Z INL/ GRB/APX
RAOBS...PLENTY OF LO CLDS LINGER OVER MUCH OF THE UPR LKS IN THE
LINGERING LLVL CYC NNW FLOW BTWN HI PRES CENTERED NEAR THE RED RIVER
VALLEY AND SFC LO IN QUEBEC. STRONG DNVA/SUBSIDENCE IN THE WAKE OF
THE DEPARTING DISTURBANCE HAS CAUSED THE SUBSIDENCE INVRN AT INL AND
APX TO SHARPEN AND FALL TO NEAR H875 AT 12Z. AT YPL...THE 12Z ROAB
SHOWS THE SUBSIDENCE INVRN HAS REACHED NEAR THE SFC. IN CONCERT WITH
LLVL DRYING...THE LO CLDS HAVE DSPTD ALONG AN AXIS FM NW ONTARIO
INTO WRN/NCENTRAL LK SUP AND THE KEWEENAW. THE SUBSIDENCE/LLVL
DRYING HAS ALSO TENDED TO DIMINISH THE -DZ/SPRINKLES THAT WERE
OCCURRING EARLIER.

MAIN FCST CONCERNS IN THE SHORT TERM ARE LO CLD TRENDS AND IMPACT ON
TEMPS TNGT.

TNGT...AS HI PRES BLDS SLOWLY EWD IN THE CONFLUENT NW FLOW ALF UNDER
RISING HGTS...EXPECT LINGERING LO CLDS OVER THE W AND CENTRAL TO
DIMINISH FAIRLY QUICKLY AS THE LLVL FLOW BACKS/BECOMES MORE ACYC AND
DRIER SFC-H925 AIR OVERSPREADS THE AREA. THE LO CLDS ARE LIKELY TO
BE MORE RESILIENT E OF MQT-ESC WITH A MORE NEUTRAL FLOW AND LESS
DRYING IN THE SFC-H925 LYR EXACERBATED BY LONGER FETCH OVER LK SUP
IN PERSISTENT NNW FLOW. THE LOWEST MIN TEMPS SHOULD OCCUR OVER THE
INTERIOR W...WHERE WINDS WL BE LIGHTER AND SKIES MOCLR AS PWAT IS
FCST TO FALL UNDER 0.5 INCH TOWARD 50-60 PCT OF NORMAL. UPSTREAM
TEMPS THIS MRNG FELL AS LO AS 40...SO GOING FCST TEMPS BOTTOMING OUT
IN THE UPR 30S AT THE COLD SPOTS OVER THE INTERIOR W LOOK ON TRACK.
PERSISTENT CLDS/ONSHORE FLOW WL CAUSE TEMPS TO RUN MUCH WARMER OVER
THE E. STEADY N WIND WL MAINTAIN HIER WAVES/HI SWIM RISK OVER THE
ALGER/MQT COUNTY BEACHES...BUT TEMPS WL BE CHILLY AND UNDER 60
DEGREES.

TUE...AS HI PRES BLDS TOWARD THE OH VALLEY...THE LLVL FLOW WL BACK
TO THE W. THIS WSHFT...LLVL DRYING AND DESCENDING SUBSIDENCE INVRN
WL BREAK UP ANY LINGERING LO CLDS OVER THE E IN THE MRNG. WITH
PLENTY OF AFTN SUNSHINE AND H85 TEMPS FCST TO WARM TO BTWN 16C OVER
THE W AND 12Z OVER THE E BY 00Z WED...EXPECT A MUCH WARMER AFTN.
MIXING TO H85 ON FCST SDNGS YIELDS HI TEMPS 75-80 OVER THE W HALF
AWAY FM LK MODERATION.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 427 PM EDT MON SEP 2 2013

NW FLOW WILL REMAIN STUCK ACROSS THE UPPER GREAT LAKES THROUGH AT
LEAST SUNDAY. AS IS TYPICAL WITH THE FAST PACED NW FLOW...TIMING OF
SMALLER DISTURBANCES WILL BE KEY IN OUR UPCOMING WEATHER...WHICH CAN
BE MORE DIFFICULT TO PREDICT.

AT 00Z WEDNESDAY OUR FIRST DISTURBANCE WILL BE SET UP ACROSS S
MANITOBA /COLD FRONT/. THE SFC-500MB LOW WILL BE SITUATED ACROSS
HUDSON BAY AND W QUEBEC...WITH THE TAIL END OF THE COLD FRONT
CROSSING LAKE SUPERIOR IN THE EVENING...BEFORE PUSHING ACROSS UPPER
MI OVERNIGHT.

OUR TUESDAY WARM-UP TO NEAR NORMAL AND SLIGHTLY ABOVE NORMAL
TEMPERATURES WILL BE SHORT LIVED...AS WE RETURN TO THE 60S FOR HIGHS
ON WEDNESDAY. 850MB TEMPS WILL FALL TO 7-10C WEDNESDAY...WHICH WILL
BE QUITE A DIFFERENCE FROM JUST 24 HOURS EARLIER WHERE THEY WERE
12-16C.

WITH CONTINUED N-NW FLOW OFF LAKE SUPERIOR 850MB TEMPS WILL CONTINUE
TO FALL TO 4-9C BY DAYBREAK THURSDAY...WITH -2C JUST NE OF LAKE
SUPERIOR. UNDER A MOSTLY CLEAR SKY...TEMPS IN THE LOW TO MID 40S MAY
NEED TO BE ADJUSTED LOWER. HUMIDITY VALUES WILL LIKELY FALL INTO THE
LOW TO MID 30S THURSDAY...ON 40S DEW POINTS AND LIGHT NW WINDS LESS
THAN 10KTS AS THE SFC HIGH SITS OVER THE UPPER GREAT LAKES. TEMPS
SHOULD JUMP BACK TO NEAR NORMAL VALUES ONCE AGAIN /70S/.

THE SFC HIGH WILL SINK TO THE OHIO VALLEY THURSDAY NIGHT...WITH
INCREASED WAA ON W WINDS..WITH TEMPS ON FRIDAY NEARING THE 80 DEGREE
MARK ACROSS THE ENTIRE CWA. THE CHANCE FOR WET WEATHER WILL RETURN
FRIDAY NIGHT THROUGH SATURDAY AS ANOTHER COLD FRONT SINKS ACROSS
FROM THE NW...FOLLOWED BY ANOTHER STRONGER SFC HIGH FOR SATURDAY
NIGHT THROUGH SUNDAY.

THERE WILL BE A CHANGE IN THE WORKS TO OUR FAR W AND E 500MB LOWS
STARTING MID WEEK...AS THE ENTIRE 500MB PATTERN BEGINS TO SLOWLY
SHIFT E. THIS WILL ALLOW THE RIDGE CENTERED OVER THE PLAINS STATE TO
BE PUSHED E ACROSS THE UPPER GREAT LAKES SUNDAY THROUGH MONDAY...IN
ADVANCE OF THE PACIFIC NW LOW MOVING TO THE CANADA/ND BORDER.

ONLY HAVE SLIGHT CHANCE THUNDER GOING FOR AND HIGH CHANCE POPS FOR
MONDAY...GIVEN THAT THE SYSTEM WILL LIKELY STILL BE SET UP ACROSS
THE DAKOTAS...AND TIMING IS A CONCERN INITIALLY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 123 PM EDT MON SEP 2 2013

AS DRY AIR PUSHES IN FM THE NNW AHEAD OF HI PRES MOVING E FM THE RED
RIVER VALLEY...EXPECT MVFR CIGS TO IMPROVE TO VFR N TO S AND AT SAW
BY 00Z. THE APRCH OF THE HI/WEAKER PRES GRADIENT WL ALSO RESULT IN
DIMINISHING/BACKING WINDS BY THIS EVNG. THEN VFR CONDITIONS WL
PREVAIL THRU 18Z TUE AS THE HI/DRIER AIRMASS DOMINATE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 317 PM EDT MON SEP 2 2013

NNW WINDS UP TO 30 KTS WITH A FEW LINGERING GALE FORCE GUSTS OVER
THE E LATE THIS AFTERNOON WILL DIMINISH TONIGHT WITH THE APPROACH OF
HI PRES FROM THE W. EXPECT A WSW WIND UP TO 20-25 KTS ON TUE...
STRONGEST OVER THE NCENTRAL WHERE THIS FLOW IS ACCENTUATED BETWEEN
THE KEWEENAW AND ISLE ROYALE...TO SHIFT TO THE NNW ON TUE NIGHT
BEHIND A COLD FRONTAL PASSAGE AND LINGER THRU THE DAY ON WED. THE
MOST PERSISTENT AND STRONGER WINDS DURING THIS EVENT WILL OCCUR OVER
THE E UNDER A SHARPER PRES GRADIENT. THEN PLAN ON WINDS UNDER 25 KTS
ON THU THRU SAT AS A RELATIVELY WEAK PRES GRADIENT AND HI OVERWATER
STABILITY DOMINATE.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ005-006.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...KF
AVIATION...KC
MARINE...KC







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 319 PM EDT MON SEP 2 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 317 PM EDT MON SEP 2 2013

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CONFLUENT NW FLOW
ALF OVER THE UPR GRT LKS TO THE W OF DEPARTING VIGOROUS SHRTWV
MOVING INTO QUEBEC AND E OF SLOWLY PROGRESSIVE UPR RDG IN THE
PLAINS. WITH LINGERING LLVL MSTR SHOWN ON THE 12Z INL/ GRB/APX
RAOBS...PLENTY OF LO CLDS LINGER OVER MUCH OF THE UPR LKS IN THE
LINGERING LLVL CYC NNW FLOW BTWN HI PRES CENTERED NEAR THE RED RIVER
VALLEY AND SFC LO IN QUEBEC. STRONG DNVA/SUBSIDENCE IN THE WAKE OF
THE DEPARTING DISTURBANCE HAS CAUSED THE SUBSIDENCE INVRN AT INL AND
APX TO SHARPEN AND FALL TO NEAR H875 AT 12Z. AT YPL...THE 12Z ROAB
SHOWS THE SUBSIDENCE INVRN HAS REACHED NEAR THE SFC. IN CONCERT WITH
LLVL DRYING...THE LO CLDS HAVE DSPTD ALONG AN AXIS FM NW ONTARIO
INTO WRN/NCENTRAL LK SUP AND THE KEWEENAW. THE SUBSIDENCE/LLVL
DRYING HAS ALSO TENDED TO DIMINISH THE -DZ/SPRINKLES THAT WERE
OCCURRING EARLIER.

MAIN FCST CONCERNS IN THE SHORT TERM ARE LO CLD TRENDS AND IMPACT ON
TEMPS TNGT.

TNGT...AS HI PRES BLDS SLOWLY EWD IN THE CONFLUENT NW FLOW ALF UNDER
RISING HGTS...EXPECT LINGERING LO CLDS OVER THE W AND CENTRAL TO
DIMINISH FAIRLY QUICKLY AS THE LLVL FLOW BACKS/BECOMES MORE ACYC AND
DRIER SFC-H925 AIR OVERSPREADS THE AREA. THE LO CLDS ARE LIKELY TO
BE MORE RESILIENT E OF MQT-ESC WITH A MORE NEUTRAL FLOW AND LESS
DRYING IN THE SFC-H925 LYR EXACERBATED BY LONGER FETCH OVER LK SUP
IN PERSISTENT NNW FLOW. THE LOWEST MIN TEMPS SHOULD OCCUR OVER THE
INTERIOR W...WHERE WINDS WL BE LIGHTER AND SKIES MOCLR AS PWAT IS
FCST TO FALL UNDER 0.5 INCH TOWARD 50-60 PCT OF NORMAL. UPSTREAM
TEMPS THIS MRNG FELL AS LO AS 40...SO GOING FCST TEMPS BOTTOMING OUT
IN THE UPR 30S AT THE COLD SPOTS OVER THE INTERIOR W LOOK ON TRACK.
PERSISTENT CLDS/ONSHORE FLOW WL CAUSE TEMPS TO RUN MUCH WARMER OVER
THE E. STEADY N WIND WL MAINTAIN HIER WAVES/HI SWIM RISK OVER THE
ALGER/MQT COUNTY BEACHES...BUT TEMPS WL BE CHILLY AND UNDER 60
DEGREES.

TUE...AS HI PRES BLDS TOWARD THE OH VALLEY...THE LLVL FLOW WL BACK
TO THE W. THIS WSHFT...LLVL DRYING AND DESCENDING SUBSIDENCE INVRN
WL BREAK UP ANY LINGERING LO CLDS OVER THE E IN THE MRNG. WITH
PLENTY OF AFTN SUNSHINE AND H85 TEMPS FCST TO WARM TO BTWN 16C OVER
THE W AND 12Z OVER THE E BY 00Z WED...EXPECT A MUCH WARMER AFTN.
MIXING TO H85 ON FCST SDNGS YIELDS HI TEMPS 75-80 OVER THE W HALF
AWAY FM LK MODERATION.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 412 AM EDT MON SEP 2 2013

TROUGH OVER QUEBEC TO START ON TUESDAY EXPECTED TO LIFT SLOWLY TO
THE NORTH THROUGH THE WEEK. TROUGH WILL EVENTUALLY BE SWEPT UP BY
STRONGER TROUGH AND VIGOROUS SFC LOW DROPPING ACROSS HUDSON BAY INTO
NORTHERN QUEBEC BY WEDNESDAY. DEEP TROUGH THEN MEANDERS ACROSS
NORTHEAST CANADA BY THE END OF THE WEEK. UPSTREAM OF THAT FEATURE
OVER THE GREAT LAKES...NW FLOW ALOFT REMAINS IN PLACE ON EDGE OF
STRONGER RIDGE CENTERED OVR THE ROCKIES. DISTURBANCES SLIDING ACROSS
UPPER GREAT LAKES IN THIS PATTERN APPEAR MINIMAL.

FIRST SFC COLD FRONT TO IMPACT THE LONG TERM DROPS ACROSS UPPER
LAKES WEDNESDAY MORNING BEFORE HIGH PRESSURE BUILDS BACK IN FOR
THURSDAY. MODEL CONSENSUS FAVORS FROPA AROUND 09Z OVR FAR NORTH CWA
SHIFTING OUT OF SOUTHERN CWA BTWN 15Z-18Z. GFS WAS SHOWING SLOWER
FROPA IN EARLIER RUNS...BUT HAS NOW TRENDED QUICKER AND IS IN LINE
WITH THE CONSENSUS. STRONG SHORTWAVE DIGGING ACROSS NORTHERN ONTARIO
EARLY WEDNESDAY MORNING WITH BULK OF DEEP LAYER Q-VECTOR CONVERGENCE
STAYING WELL TO NORTH. HOWEVER...AREA OF WEAKER H7-H3 Q-VECTOR
CONVERGENCE AND ENHANCED H8-H7 RH COULD CLIP EASTERN CWA BTWN 09Z-
15Z. 5KM NAM DNG ONLY MODEL THAT GENERATES LGT QPF THERE. SOME OTHER
MODELS DO KICK OFF SOME DZ OVR UPSLOPE AREAS OF NCNTRL UPR MICHIGAN
THOUGH. LOW-LEVEL MOISTURE LOOKS VERY TRANSIENT THOUGH AND SUBSIDENCE
BEHIND THIS BRIEF UPTICK OF MOISTURE IS STRONG. WILL KEEP FCST
DRY...BUT IF THESE SIGNALS PERSIST MAY NEED TO ADD A BRIEF PERIOD OF
SOME LGT PRECIP EARLY ON WEDNESDAY. IN WAKE OF THE FRONT...NORTH
WINDS AND THERMAL TROUGHING AT H9 SHOULD KEEP TEMPS ON THE COOLER
SIDE...ESPECIALLY OVER THE NORTH CWA DUE TO GUSTY NORTH-NORTHWEST
WINDS OFF LK SUPERIOR. BASED ON MIXING TO H9-H875 WOULD EXPECT HIGHS
IN THE LOW TO MID 60S NORTH AND MAYBE INTO THE LOWER 70S SOUTH. EVEN
IN THE SOUTH CWA...READINGS MAY HAVE HARD TIME REACHING 70 DEGREES IF
MODELS ARE CORRECT WITH STRENGTH OF THERMAL TROUGHING. GUSTY WINDS
AND COLD AIR ADVECTION WILL KICK UP WAVES ON LK SUPERIOR RESULTING IN
ANOTHER HIGHER SWIM RISK FOR WEDNESDAY.

KEPT THE COOLER THEME GOING INTO WEDNESDAY NIGHT AS WELL AS WINDS
BECOME LIGHT AND AIRMASS ACROSS AREA IS DRY WITH PWATS LESS THAN
0.50 INCHES. MAY SEE THIN MID CLOUDS...BUT DO NOT EXPECT THESE TO
IMPACT TEMPS TOO MUCH. TRENDED MIN TEMPS TOWARD THE BIAS CORRECTED
NAM/GFS/ECMWF WHICH RESULTED IN READINGS AS LOW AS 40 DEGREES IN
FAVORED COLD SPOTS. MAY EVEN BE A BIT COOLER...BUT NOT QUITE BUYING
THE MID 30S IN PARTS OF THE CNTRL AND EASTERN CWA THAT SOME GUIDANCE
SHOWED...NOT QUITE YET ANYWAY.

GENERALLY AHEAD OF ANOTHER COLD FRONT THURSDAY INTO FRIDAY...THEN
ANOTHER FRONT DROPS ACROSS UPPER LAKES FRIDAY OR FRIDAY NIGHT.
AIRMASS NOT ALL THAT COLD AHEAD OF THIS FRONT...SO TEMPS ON THU
SHOULD END UP AT OR A BIT ABOVE NORMAL. TEMPS ON FRIDAY MAY END
UP WELL ABOVE NORMAL AS LOW-LEVEL WINDS ARE FM WSW AND H85 TEMPS ARE
OVER +16C. COULD SEE WIDESPREAD 80S IF CLOUDS/PRECIP DO NOT MUDDLE
THINGS TOO MUCH. PREVIOUS ECMWF AND RECENT GEM-NH SHOWED COLD FRONT
COMING IN QUICKER ON FRIDAY AFTN WHILE LATEST ECMWF SHOWS FROPA MORE
FRIDAY NIGHT WITH THE GFS MORE ON SATURDAY. NOT TOO SURPRISING THIS
FAR OUT...BUT ECMWF HAS BEEN A BIT BACK AND FORTH ON TIMING OF
FRONT...SO CONFIDENCE IN DETAILS LOWER BY FRIDAY. A QUICKER FRONTAL
PASSAGE WOULD SUPPORT BETTER CHANCE OF SHRA/TSRA OVER PARTS OF CWA ON
FRIDAY AS INSTABILITY AND SHEAR /MLCAPES UP TO 1000J/KG AND 0-6KM
SHEAR UP TO 30 KTS/ LOOK SUFFICIENT ENOUGH GIVEN STRONG ENOUGH
CONVERGENCE FROM FRONT. GIVEN THE TIMING CONCERNS WITH FROPA...KEPT
THE SLIGHT CHANCE POPS THAT MODEL CONSENSUS YIELDS. DOES SEEM THAT
ONCE THE TIMING OF FRONT IS BETTER AGREED UPON...POPS COULD BE
INCREASED FOR A BRIEF TIME DURING THE EXPECTED FROPA.

HIGH PRESSURE THEN BUILDS ACROSS UPPER GREAT LAKES FOR NEXT WEEKEND.
FRONTAL BOUNDARY THAT MOVES THROUGH EARLY IN THE WEEKEND MAY REMAIN
ACTIVE JUST TO SOUTH AND WEST OF CWA WITH A LOT OF WARMTH AND
INSTABILITY POOLING OVER THE PLAINS AND FOLDING INTO THE FRONTAL
BOUNDARY. AS LONG AS SFC OR H85 BOUNDARIES STAY TO SOUTH AND WEST AS
ECMWF AND WPC HAND DRAWN PROGS INDICATE...SHOULD SEE DRY WEATHER MOST
OF NEXT WEEKEND WITH TEMPS AROUND NORMAL.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 123 PM EDT MON SEP 2 2013

AS DRY AIR PUSHES IN FM THE NNW AHEAD OF HI PRES MOVING E FM THE RED
RIVER VALLEY...EXPECT MVFR CIGS TO IMPROVE TO VFR N TO S AND AT SAW
BY 00Z. THE APRCH OF THE HI/WEAKER PRES GRADIENT WL ALSO RESULT IN
DIMINISHING/BACKING WINDS BY THIS EVNG. THEN VFR CONDITIONS WL
PREVAIL THRU 18Z TUE AS THE HI/DRIER AIRMASS DOMINATE.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 317 PM EDT MON SEP 2 2013

NNW WINDS UP TO 30 KTS WITH A FEW LINGERING GALE FORCE GUSTS OVER
THE E LATE THIS AFTERNOON WILL DIMINISH TONIGHT WITH THE APPROACH OF
HI PRES FROM THE W. EXPECT A WSW WIND UP TO 20-25 KTS ON TUE...
STRONGEST OVER THE NCENTRAL WHERE THIS FLOW IS ACCENTUATED BETWEEN
THE KEWEENAW AND ISLE ROYALE...TO SHIFT TO THE NNW ON TUE NIGHT
BEHIND A COLD FRONTAL PASSAGE AND LINGER THRU THE DAY ON WED. THE
MOST PERSISTENT AND STRONGER WINDS DURING THIS EVENT WILL OCCUR OVER
THE E UNDER A SHARPER PRES GRADIENT. THEN PLAN ON WINDS UNDER 25 KTS
ON THU THRU SAT AS A RELATIVELY WEAK PRES GRADIENT AND HI OVERWATER
STABILITY DOMINATE.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  BEACH HAZARDS STATEMENT THROUGH LATE TONIGHT FOR MIZ005-006.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC







AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 127 PM EDT MON SEP 2 2013

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 324 AM EDT MON SEP 2 2013

A COLD FRONT IS MOVING THROUGH LOWER MICHIGAN EARLY THIS MORNING.
MUCH DRIER AND COOLER AIR WILL FLOW INTO THE REGION TODAY RESULTING
IN HIGHS IN THE LOWER TO MID 70S AND MUCH LOWER HUMIDITY.
TEMPERATURES WILL SLOWLY WARM TO THE LOWER 80S BY THE END OF THE
WEEKEND. DRY WEATHER IS EXPECTED THIS WEEK.

&&

.UPDATE...
ISSUED AT 1142 AM EDT MON SEP 2 2013

MODELS ARE FORECASTING A FAIR AMOUNT OF MOISTURE IN BOTH THE
925-850MB AND THE 950-900MB LAYERS. DEEP CYCLONIC FLOW WILL REMAIN
IN PLACE THROUGH THE COURSE OF THE AFTERNOON AS WELL WITH DELTA
T/S OVER LAKE MICHIGAN ON THE ORDER OF 14 DEGREES C. ALL OF THESE
FACTORS LEAD TOWARD A DECENT AMOUNT OF CLOUD COVER. EXPECT SKIES
TO STAY MAINLY CLOUDY IN THE NORTHERN PORTION OF THE FORECAST
AREA (U.S. 10)...BECOMING MOSTLY CLOUDY IN THE CENTRAL (I-96) AND
VARYING CONDITIONS IN THE SOUTH (I-94) BETWEEN PARTLY SUNNY AND
MOSTLY CLOUDY.

THE CLOUDS AND COLD AIR ADVECTION SHOULD KEEP HIGHS BELOW NORMALS
FOR THIS TIME OF YEAR. HIGHS WILL TOP OUT IN THE MID TO UPPER 60S
NORTH AND MID 70S IN THE FAR SOUTH. CANNOT RULE OUT A FEW
SPRINKLES OFF OF LAKE MICHIGAN THIS AFTERNOON AND EVENING BUT HAVE
NOT PUT THEM IN THE FORECAST AT THIS POINT.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 324 AM EDT MON SEP 2 2013

FORECAST CONCERNS ARE MINIMAL THIS MORNING AS DRY WX IS EXPECTED
THROUGH THE PERIOD.

SFC ANALYSIS SHOWS A COLD FRONT HAS PUSHED THROUGH THE CWA. THE LAST
OF THE SHOWERS THAT DEVELOPED AHEAD OF THE FRONT HAVE ALSO MOVED
EAST OUT OF THE CWA. IR LOOP SHOWS CLEAR SKIES MOVING IN BEHIND THE
FRONT. THAT WILL BE SHORT LIVED THOUGH BECAUSE A LARGE AREA OF
STRATOCU OVER ONTARIO/NRN LWR IS MOVING SOUTH ON THE HEELS OF A
NORTH WIND. H9 RH PROGS SUGGEST THAT QUITE A BIT OF CLOUDINESS
WILL BE WITH US THROUGH TONIGHT COURTESY OF A STRONG SHORT WAVE
MOVING ACROSS NRN LAKE HURON. A LARGE DOME OF HIGH PRESSURE OVER
THE CENTRAL ROCKIES WILL RESULT IN NW FLOW OVER THE GREAT LAKES.
THIS IS USUALLY A DRY FLOW AND THAT/S WHAT WE/LL SEE THROUGH
WEDNESDAY. AFTER THE SHORT WAVE MOVES EAST LATE TONIGHT...CLEARING
WILL OCCUR.

HIGHS TODAY WILL RUN FROM THE MID 60S IN THE NORTH TO MID 70S IN THE
SOUTH. WE/LL SEE A GRADUAL WARMING TREND THROUGH WEDNESDAY AS SOME
WARMER AIR FROM THE PLAINS GETS PUSHED NEWD TOWARD THE GREAT LAKES
AHEAD OF THE NEXT FRONT MIDWEEK.

.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 324 AM EDT MON SEP 2 2013

NOT MUCH IN THE WAY OF WEATHER IN THE EXTENDED AS ONLY A SLIGHT
CHANCE OF RAIN EXPECTED WITH A COLD FRONT PASSAGE ON SATURDAY. THE
ECMWF IS NOW A BIT QUICKER THAN THE GFS WITH SHOWERS COMING IN
FRIDAY NIGHT. KEPT POPS LIMITED TO SATURDAY.

WEDNESDAY NIGHT OR THURSDAY COULD ALSO HAVE A FEW SHOWERS AS A COLD
FRONT COMES THROUGH...BUT IT IS WEAKENING AND MOISTURE IS LIMITED SO
DECIDED TO KEEP THOSE PERIODS DRY FOR NOW.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 130 PM EDT MON SEP 2 2013

AREAS OF LAKE ENHANCED MVFR BKN CLOUD CEILINGS THROUGH EVENING WITH VFR
SCT CLDS OVERNIGHT. BEST COVERAGE WILL BE NORTHWEST OF A KAZO TO
KLAN LINE. CLOUD BASES WILL RANGE FROM 025-035 KFT WITH TOPS
GENERALLY BELOW 080 KFT.

MAY SEE SOME VERY LOCALIZE FOG IN LOW LYING AREAS...RIVERS...ETC
TUE MORNING BUT AGAIN...VERY LOCALIZED.

OUTLOOK...VFR CLOUD CEILINGS 030-050 KFT POSSIBLE TUE MIDDAY THEN
CIG AND VIS UNLIMITED FROM TUE AFTN THROUGH WED.

&&

.MARINE...
ISSUED AT 1142 AM EDT MON SEP 2 2013

WINDS BENT MORE OFF SHORE THIS MORNING AND WHILE WAVES WERE UP
INITIALLY AT THE BEACHES THEY HAVE DROPPED SOME MID TO LATE
MORNING. THE HRRR FORECASTS THE WINDS TO COME BACK TO ABOUT 340
DEGREES OR FROM THE NORTH-NORTHWEST THIS AFTERNOON AND EVENING.
THEREFORE NO CHANGES WERE MADE TO THE SMALL CRAFT ADVISORY OR THE
BEACH HAZARDS STATEMENT. WHILE THE DIRECTION IS NOT IDEAL FOR HIGH
WAVES RIGHT AT THE SHORE IT SHOULD BE GOOD ENOUGH TO PRODUCE 3-5
FOOTERS AS WE HEAD THROUGH THE COURSE OF THE AFTERNOON AND
EVENING. STRUCTURAL CURRENTS AND LONGSHORE CURRENTS WILL BECOME
MORE OF A PLAYER TOO AS THE WINDS BACK. THE HIGHEST WAVES IN THIS
FLOW REGIME WILL BE NORTH OF WHITEHALL AND SOUTH OF HOLLAND. AS
EXPECTED...THE CLOUDS AND COOL TEMPERATURES HAVE KEPT BEACH
POPULATION DOWN WITH THE SURF CAM AT GRAND HAVEN SHOWING LIMITED
FOLKS ON THE BEACH. FOR THOSE ON THE BEACH HOWEVER CONDITIONS WILL
BECOME MORE HAZARDOUS AS WE HEAD THROUGH THE DAY...ESPECIALLY
BEACHES ON THE NORTH SIDES OF NORTH PIERS AND BREAKWALLS.


&&

.HYDROLOGY...
ISSUED AT 324 AM EDT MON SEP 2 2013

NO HYDRO CONCERNS. DRY WEATHER IS EXPECTED THIS WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 8 PM EDT THIS EVENING FOR MIZ037-
     043-050-056-064-071.

LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>849.

&&

$$

UPDATE...DUKE
SYNOPSIS...93
SHORT TERM...93
LONG TERM...OSTUNO
AVIATION...COBB
HYDROLOGY...93
MARINE...DUKE







AREA FORECAST DISCUSSION

NWS JACKSON MS

 1117 AM CDT MON SEP 2 2013

.UPDATE...

HAVE MADE A FEW MORE CHANGES SINCE THE EARLIER UPDATE. THE MOST
SIGNIFICANT UPDATE WAS TO REMOVE THE RISK FOR SEVERE STORMS ALONG
THE HIGHWAY 82 CORRIDOR IN THE GRAPHICS/HWO FOR THIS AFTERNOON/
EVENING. HAVE ALSO SHIFTED BETTER NEAR TERM POPS FARTHER SOUTH AND
CUT BACK ON TODAY`S TEMPERATURES A LITTLE MORE IN CURRENT RAIN AREA.

THE COMPLEX OF SHOWERS/THUNDERSTORMS ACROSS NORTHWEST PORTIONS OF
THE ARKLAMISS HAS DIMINISHED SOME...AND CLOUDS/RAIN ARE KEEP THE
AIRMASS MORE STABLE...THUS LIMITING ANY CONCERN FOR SEVERE STORMS.
HOWEVER...CONTINUED REGENERATION OF CONVECTION ON THE UPSTREAM SIDE
OF THE COMPLEX HAS RAISED SOME CONCERN FOR HEAVY RAINFALL AND MINOR
FLOODING IN THE BOLIVAR/SUNFLOWER COUNTY AREA FOR THE NEXT HOUR OR SO
AND WE ARE MONITORING THIS FOR THE NEAR TERM.

OTHERWISE...SHALLOW OUTFLOW FROM THIS COMPLEX IS MOVING SOUTH WITHOUT
DEEP CONVECTIVE DEVELOPMENT IN THE CAPPED AIRMASS. WITH CONTINUED
DAYTIME HEATING AND DESTABILIZATION...THE RISK FOR STORMS TO DEVELOP
WILL INCREASE ALONG THE BOUNDARY AS IT STALLS SOUTH AND EAST OF THE
CURRENT COMPLEX...BUT THE MOST RECENT HRRR/WRF GUIDANCE CONTINUE TO
BE BEARISH WITH TSTM DEVELOPMENT LATER THIS AFTERNOON/EVENING...SO
HAVE NOT RAISED POPS VERY MUCH. A FEW STRONG PULSE-TYPE STORMS WILL
BE POSSIBLE IF STORMS CAN DEVELOP IN AREAS THAT RECEIVE THE GREATEST
HEATING...ESPECIALLY ALONG AND NORTH OF THE I-20 CORRIDOR. /EC/

&&

.PREV DISCUSSION... /ISSUED 902 AM CDT MON SEP 2 2013/

UPDATE...

A COMPLEX OF SHOWERS/THUNDERSTORMS AFFECTING THE HIGHWAY 82
CORRIDOR...ESPECIALLY IN THE DELTA REGION IS BRINGING HIGH COVERAGE
OF RAINFALL AND HAVE INCREASED POPS TO REFLECT THIS. THE EXPECTATION
IS THAT THIS COMPLEX WILL DIMINISH AS IT MOVES SOUTHEAST INTO A MORE
STABLE MID LEVEL ENVIRONMENT LATER THIS MORNING AND EARLY AFTERNOON.
WITH STRONG AFTERNOON HEATING...STORMS COULD ERUPT ALONG ANY
DIFFERENTIAL/OUTFLOW BOUNDARIES PRODUCED BY THIS COMPLEX...HOWEVER
THE HRRR AND ASSORTMENT OF WRF GUIDANCE ARE STINGY WITH ADDITIONAL
CONVECTIVE DEVELOPMENT LATER THIS AFTN. SO CONFIDENCE IN CONVECTIVE
BEHAVIOR/EVOLUTION TODAY IS LOWER THAN USUAL. /EC/

PREV DISCUSSION... /ISSUED 405 AM CDT MON SEP 2 2013/

SHORT TERM...TODAY THROUGH TUESDAY NIGHT...UPPER RIDGING THAT HAS
BEEN PRESENT OVER OUR REGION THIS WEEKEND WILL CONTINUE TO
RETROGRADE TO THE WEST. IN ADDITION...AN UPPER TROUGH WILL BE
SITUATED ACROSS THE OHIO VALLEY/EASTERN THIRD OF THE UNITED STATES.
THIS WILL LEAVE THE ARKLAMISS REGION BETWEEN THESE TWO UPPER LEVEL
FEATURES AND GENERALLY UNDER NORTHWEST FLOW ALOFT. THIS WILL HELP TO
BRING A SHORTWAVE TROUGH INTO OUR REGION TODAY AHEAD OF A FRONTAL
BOUNDARY. THIS TROUGH LOOKS TO BE RESPONSIBLE FOR THE CONVECTION
CONTINUING ACROSS PORTIONS OF THE MID SOUTH EARLY THIS MORNING.
MODELS INDICATE THAT CONVECTION SHOULD CONTINUE TO DEVELOP THROUGH
THE DAY IN ASSOCIATION WITH THIS SHORTWAVE TROUGH...THE APPROACHING
FRONTAL BOUNDARY...AND LEFTOVER MESOSCALE OUTFLOW BOUNDARIES PRESENT
ACROSS THE AREA. GIVEN COOL MIDLEVEL TEMPERATURES AROUND -6 TO -8C
PRESENT ACROSS THE REGION LEADING TO VERTICAL TOTALS AROUND
28-29C...AMPLE MOISTURE...AND SUFFICIENT DAYTIME HEATING...
CONVECTION WILL INCREASE LATER THIS AFTERNOON ITO THE EVENING. SOME
OF THE STORMS COULD BE SEVERE GIVEN THE BETTER LAPSE RATES AND WILL
CONTINUE TO ADVERTISE THIS POTENTIAL...ESPECIALLY GIVEN THE LABOR
DAY HOLIDAY. THE BEST CONDITIONS APPEAR TO BE NORTH OF I-20 AND
ESPECIALLY NORTH OF HIGHWAY 82 CORRIDOR.

WITH THE FRONTAL BOUNDARY LINGERING ACROSS THE REGION...SHOWERS AND
STORMS WILL LINGER THROUGH THE NIGHT AND INTO TUESDAY ALONG AND
SOUTH OF THE FRONT. BEHIND THE FRONT...DRIER AIR WILL BEING TO
FILTER INTO THE REGION ON TUESDAY. THIS...ALONG WITH COOLER LOW
LEVEL TEMPERATURES...WILL HELP TO MAKE FOR A RATHER PLEASANT DAY ON
TUESDAY FOR LOCATIONS ESPECIALLY NORTH OF I-20/HIGHWAY 82. BY 12Z
WEDNESDAY...MODEL PW VALUES SHOW LOCATIONS SOUTH OF I-20 SEEING
VALUES AROUND 1.5 INCHES...WHEREAS LOCATIONS NORTH OF I-20 WILL BE
AROUND 1-1.3 INCHES. GUIDANCE HAS CONTINUOUSLY BEEN SHOWING MUCH
COOLER TEMPERATURES ON TUESDAY WITH ENSEMBLE MEANS AROUND THE UPPER
80S FOR HIGHWAY 82 CORRIDOR. CONTINUED THE TREND OF CUTTING MAV
GUIDANCE BY A DEGREE OR TWO IN ACCORDANCE WITH THIS AIRMASS BEING
BEHIND THE BOUNDARY. THE MORE NOTICEABLE CHANGE WILL COME IN
OVERNIGHT LOWS. LOWS ON TUESDAY NIGHT WILL BE IN THE MID TO LOWER
60S ACROSS THE NORTHERN COUNTIES. /28/

LONG TERM...WEDNESDAY THROUGH SUNDAY...THE CWA WILL BE DIVIDED IN
HALF THROUGH MUCH OF THE LONG TERM WITH A DRIER AIRMASS AND VERY
LITTLE CHANCE FOR RAIN ACROSS THE NORTH WITH DEEP MOISTURE AND
GREATEST RAIN CHANCES CONTINUING ACROSS THE SOUTH.  COME WEDNESDAY
MORNING A LARGE MID LEVEL(595DAM) HIGH WILL BE CENTERED OVER
COLORADO WITH A 1020MB SURFACE RIDGE CENTERED OVER THE TENNESSEE AND
OHIO VALLEYS. A STALLED COLD FRONT IS EXPECTED TO BE DRAPED ACROSS
THE SOUTHERN PORTIONS OF OUR CWA. A DRIER AIRMASS WITH PWS BELOW AN
INCH AND A HALF AND MID 60 SURFACE DEWPOINTS WILL RESIDE NORTH OF
THE FRONT WHILE NEAR TWO INCH PWS AND LOWER 70 DEW POINTS CONTINUE
ACROSS THE SOUTHERN THIRD OF OUR CWA. THIS DRIER AIRMASS WILL LEAD
TO BELOW NORMAL MORNING LOWS ACROSS THE NORTH THROUGH THE END OF THE
WEEK. WARMER THAN NORMAL AFTERNOON HIGHS WILL CONTINUE HOWEVER THE
GFS MOS WAS AMONG THE HIGHEST ENSEMBLE MEMBER AND HAVE LEANED TOWARD
ENSEMBLE MEAN HIGHS THURSDAY THROUGH THE END OF THE WEEK. MAINLY
AFTERNOON AND EARLY EVENING RAIN CHANCES WILL BE CARRIED SOUTH OF
INTERSTATE 20 WEDNESDAY WHILE WL LEAVE OUT MENTION NORTH OF
INTERSTATE 20. VERY LITTLE CHANGE IN SENSIBLE WEATHER IS EXPECTED
OVER OUR AREA THURSDAY BUT A SECOND STRONGER SURFACE HIGH WILL DROP
OUT OF THE NORTHERN PLAINS ACROSS THE GREAT LAKES REGION THURSDAY
NIGHT AND THEN TO THE MID ATLANTIC SEABOARD FRIDAY. THIS WILL
REINFORCE THE DRY NORTH TO NORTHEAST FLOW ACROSS OUR REGION AND
NUDGE THE STALLED FRONTAL BOUNDARY JUST SOUTH OF HIGHWAY 84. DRY
CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE NORTHERN TWO THIRDS
OF OUR CWA BUT MODEL CONSENSUS SUGGESTS CARRYING LOW POPS ACROSS THE
HIGHWAY 84 CORRIDOR FRIDAY AND SATURDAY. THE LARGE MID LEVEL RIDGE
WILL BREAK DOWN SUNDAY INTO MONDAY WHILE WEAK SURFACE RIDGING
BECOMES ORIENTED ALONG THE GULF COAST. DEEPER MO

&&

.AVIATION...

SHOWERS AND THUNDERSTORMS ARE AFFECTING THE GLH-GWO-CBM/GTR CORRIDOR
THIS MORNING. THIS ACTIVITY WILL DIMINISH BY EARLY AFTERNOON...WITH
ISOLATED AFTERNOON STORMS POSSIBLE NEAR TAF SITES THIS AFTERNOON AND
EVENING. OTHERWISE...MORNING MVFR CATEGORIES WILL BE POSSIBLE AGAIN
EARLY TUESDAY MORNING...ESPECIALLY IN AREAS THAT RECEIVE RAINFALL.

&&

.PRELIMINARY POINT TEMPS/POPS...
JACKSON       96  71  92  68 /  16  36  21  13
MERIDIAN      95  70  92  67 /  20  36  23   8
VICKSBURG     96  69  93  67 /  31  41  22  13
HATTIESBURG   97  73  96  72 /  20  20  32  17
NATCHEZ       96  72  93  71 /  16  25  35  20
GREENVILLE    93  70  92  65 /  64  39  14  11
GREENWOOD     92  69  92  64 /  61  41  13  10

&&

.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS BINGHAMTON NY

 1216 PM EDT MON SEP 2 2013

.SYNOPSIS...
A COLD FRONT WILL BRING ANOTHER ROUND OF THUNDERSTORMS TO NY AND
PA TODAY. SOME OF THESE STORMS MAY PRODUCE HAIL...GUSTY
WINDS...AND HEAVY RAIN. THE FRONT WILL STALL JUST TO OUR EAST ON
TUESDAY, WITH A CHANCE FOR A FEW SHOWERS OVER OUR REGION. COOLER
AND DRIER WEATHER IS FORECAST FOR MID WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NOON UPDATE...

MORNING WRAP UP AND FLOOD POTENTIAL...QUICK UPDATE WITH A BUSY MORNING BEHIND
US AND AN ACTIVE AFTERNOON EXPECTED. AREA OF CONFECTION FROM THIS
MORNING IS JUST ABOUT TO CLEAR OUR CWA. FLOODING EARLIER ACROSS
SCHUYLER COUNTY NEAR MECKLENBURG IS BEGINNING TO DIMINISH. A CALL
TO THE 911 CENTER LET US KNOW THAT MOST OF THE MAJOR ROADS ARE NOW
OPEN AGAIN BUT STILL ENOUGH ISSUES ON SECONDARY ROADS TO KEEP THE
FLASH FLOOD WARNING UP THROUGH 1245 PM BEFORE LETTING IT EXPIRE.
THIS AREA ALONG WITH FARTHER EAST THROUGH NORTHERN BROOME...AND
PARTS OF CHENANGO COUNTY...ALONG WITH WESTERN LUZERNE (FROM LAST
NIGHTS RAIN) WILL HAVE TO BE CAREFULLY WATCHED FOR FLASH FLOOD
POTENTIAL DUE TO THE SATURATED GROUND. REFER TO THE GRAPHICAL HWO
N OUR WEBSITE (WEATHER.GOV/BGM CLICK ON HAZARDOUS WEATHER OUTLOOK
AT THE TOP THEN FLOODING) TO SEE THE AREAS OF CONCERN. IS IT IMPORTANT
TO NOTE THAT IT WAS THE RATE OF RAINFALL (1.5"+ IN LESS THAN AN
HOUR) THAT LIKELY CAUSED THE PROBLEM. THE STORM TOTAL FROM KBGM
WAS JUST RESET AS IT WAS A RUNNING TOTAL FOR MORE THAN 24 HOURS
AND WE WANTED TO HAVE A CLEAN SLATE FOR THIS AFTERNOON`S
CONVECTION.

AFTERNOON SEVERE THREAT...ISOLATED STORMS HAVE ALREADY POPPED UP
ACROSS BRADFORD COUNTY PA WITH A DECENT CORE ALOFT (HAIL) AND
BACK BUILDING TENDENCIES (FLASH FLOOD THREAT). MEANWHILE MORE CONVECTION
IS EXPECTED TO FIRE OVER WNY AHEAD OF A COLD FRONT. WIND SHEAR IS
THE ONLY LIMITING FACTOR AT AROUND 25 KTS FOR 0-6 KM SHEAR.
WE HAVE PLENTY OF DYNAMICAL FORCING WITH THE SURFACE FRONT AND
UPPER LEVEL TROF SWINGING THROUGH TO COMPENSATE FOR THE WEAKER
SHEAR. IN ADDITION SBCAPES ARE OVER 2000 J/KG THANKS TO INCREASING
SUNSHINE AND A VERY MOIST ENVIRONMENT. OUR LOCAL SEVERE WEATHER CHECKLIST
POINTS TO A HAIL DAY WITH VERY DRY AIR IN THE MID LEVELS AND
STRONG MID LEVEL LAPSE RATES. WITH HAIL BEING THE NUMBER 1
THREAT...WIND IS NOT FAR BEHIND DUE TO THE DRY AIR IN THE MID
LEVELS AND WE MENTIONED FLASH FLOODING THREAT ABOVE. EXPECT
ISOLATED TO SCT. CONVECTION NEXT FEW HOURS...THEN BKN LINES OF
STORMS TO DEVELOP BETWEEN 18Z AND 21Z OVER THE FINGER LAKES BEFORE
MOVING SOUTH AND EAST. THE HRRR AND ARW SEEM TO HAVE A DECENT
HANDLE ON THIS SCENARIO IF YOU WANT A GRAPHICAL VIEW.



&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
COLD FRONT WILL STALL TO OUR EAST ON TUESDAY AS UL TROF SAGS
SOUTHEASTWARD OUT OF ONTARIO AND INTO NORTHERN NY. DESPITE DRY AIR
ADVECTION, THE PRESENCE OF THE TROF WILL KEEP A FEW SHOWERS OVER
FA THROUGH THE AFTERNOON HOURS.

BY EARLY WEDNESDAY, WE FINALLY GET ON THE WESTERN EDGE OF THE TROF
AXIS. PRECIP WILL SHIFT EASTWARD TO THE COAST, WHILE SKIES WILL
BEGIN TO CLEAR OVER NY/PA. THE COOL POOL ALOFT WILL BE DIRECTLY
OVERHEAD, KEEPING TEMPS IN THE LOWER 70S FOR MUCH OF THE FA.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
3 AM UPDATE...
NO CHGS NEEDED TO LONG TERM AT THIS TIME AS UL RIDGE HOLDS ACRS
WRN U.S. THRU SUNDAY BEFORE STARTING TO FLATTEN OUT EARLY NEXT
WEEK.

250 PM UPDATE...

A FAIRLY QUIET EXTENDED PERIOD WITH A FEW WEAK FRONTAL BOUNDARIES
BRINGING CHCS FOR PRECIP. FIRST BOUNDARY EARLY IN THE PD WILL
BRING JUST SLGT CHCS FOR SHRA MAINLY TO NRN PORTION OF FA WED
NGT/EARLY THURS. ANOTHER CLD FRONT SATURDAY MAY BRING SOMEWHAT
BETTER CHCS FOR PRECIP. MAIN STORY LATER THIS WEEK WILL BE COOLER
AIRMASS WITH HIGHS PSBLY NOT GETTING OUT OF THE 60S FOR A LARGE
PART OF THE FA ON THURSDAY WITH LOWS DROPPING WELL INTO THE 40S
FRIDAY MORNING. BEYOND THAT, TEMPS MODERATE TO NEAR OR SLIGHTLY
ABOVE FOR HIGHS BY THE WEEKEND AS SFC HIGH PRESSURE MOVES OVER AND
THEN SE OF THE REGION.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
12Z UPDATE...
CONDITIONS RANGE FROM VFR TO LIFR AS AIRMASS SATURATED FROM RAIN
LAST NIGHT RESULTS IN DENSE FOG DEVELOPMENT AT SOME TERMINALS.
HOWEVER TERMINALS THAT ARE CURRENTLY BEING AFFECTED BY SHOWERS
HAVE IMPROVING CONDITIONS. KBGM AND KAVP ARE CURRENTLY AT IFR AND
WILL REMAIN THERE THROUGH 13Z THIS MORNING. AT KITH AND KELM
EXPECT MVFR CONDITIONS IN LIGHT SHRA THROUGH 14Z WITH KSYR AND
KRME REMAINING VFR.

CONDITIONS IMPROVE TO A BKN-OVC VFR DECK AFTER 15Z AT ALL
TERMINALS ALONG WITH A BRIEF BREAK IN THE RAIN. COLD FRONT WILL
APPROACH FROM THE NORTHWEST AFTER 20Z THIS AFTERNOON WITH MVFR
RESTRICTIONS POSSIBLE. FOLLOWING FRONTAL PASSAGE EXPECT TERMINALS
TO DROP TO MVFR OVERNIGHT.

LGT/VRB WINDS THIS MORNING WILL BECOME MORE SWRLY AROUND 5KTS
DURING THE DAY SHIFTING TO THE NORTHWEST TOWARD MIDNIGHT.

OUTLOOK...

TUE...POTENTIAL FOR MVFR IN SCT SHRA.

WED-FRI...MAINLY VFR WITH POTENTIAL MORNING RESTRICTIONS DUE TO
FOG.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.

&&

$$
SYNOPSIS...DJP/HEDEN
NEAR TERM...DJP/HEDEN
SHORT TERM...DJP
LONG TERM...JML/PVN
AVIATION...PVN







AREA FORECAST DISCUSSION

NWS RALEIGH NC

 249 PM EDT MON SEP 2 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST TONIGHT...
THEN PUSH SLOWLY SOUTHEAST THROUGH THE CAROLINAS ON TUESDAY. IN THE
WAKE OF THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION ON
WEDNESDAY AND LINGER THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1220 PM MONDAY...

OVERVIEW:
CYCLONIC FLOW ALOFT WILL PERSIST ACROSS THE CAROLINAS AND
MID-ATLANTIC THROUGH TONIGHT AS A POTENT UPPER LEVEL LOW TRACKS
SLOWLY EAST FROM THE UPPER GREAT LAKES TOWARD QUEBEC/NEW ENGLAND. AN
ASSOCIATED COLD FRONT...EXTENDING SOUTHWEST FROM THE LOWER GREAT
LAKES TO THE LOWER MS RIVER VALLEY THIS MORNING...WILL TRACK SLOWLY
SOUTHEAST TO THE SOUTHERN APPALACHIANS TONIGHT.

INSTABILITY:
EXPECT MODERATE TO PERHAPS STRONG DESTABILIZATION BY PEAK HEATING
THIS AFTERNOON AS STEEPER MID-LEVEL LAPSE RATES (6.0-7.0 C/KM)
ADVECT INTO THE REGION FROM THE N/NW ATOP A WARM/MOIST LOW-LEVEL
AIRMASS. A SMALL (BUT NOTICEABLE) DEWPOINT DISCONTINUITY WILL
PERSIST ACROSS THE SANDHILLS AND COASTAL PLAIN TODAY...WITH SFC
DEWPOINTS 73-75F ALONG AND EAST OF A LINE FROM RCZ-FBG-RWI.
INSOLATION COMBINED WITH THE AFOREMENTIONED MOISTURE IN THE
SANDHILLS/SE COASTAL PLAIN HAS RESULTED IN COMPLETE EROSION OF CINH
AND 1500 J/KG MLCAPE AS OF 15Z...AND THIS AREA SHOULD SEE MLCAPE
VALUES OF 2000-3000 J/KG BY PEAK HEATING. IN THE N/NW PIEDMONT...
DESPITE A SLIGHTLY DRIER LOW-LEVEL AIRMASS...STEEPER MID-LEVEL LAPSE
RATES SHOULD CONTRIBUTE TO MODERATE DESTABILIZATION WITH MLCAPE
VALUES OF 1000-2000 J/KG. A DRIER MID-LEVEL AIRMASS ASSOCIATED WITH
THE MODIFIED EML ADVECTING INTO THE MID-ATLANTIC WILL CONTRIBUTE TO
HIGHER DCAPE IN COMPARISON TO PREVIOUS DAYS...RANGING FROM 750-1250
J/KG AT PEAK HEATING...HIGHEST ALONG AND JUST EAST OF HWY 1.

PRECIP CHANCES:
EXTREMELY CHALLENGING FORECAST. SHALLOW CONVERGENCE ASSOCIATED WITH
A LOW-LEVEL TROUGH OVER THE COASTAL PLAIN WILL BE PRESENT THROUGH
EARLY AFTERNOON...THOUGH THIS CONVERGENCE ZONE MAY EFFECTIVELY
RETROGRADE TO THE HWY 1 CORRIDOR LATER THIS AFT/EVE AS LOW-LEVEL
FLOW OVER WESTERN NC BACKS FROM NW-W IN ASSOC/W VERY WEAK HEIGHT
FALLS AND INCREASING CYCLONIC SHEAR VORTICITY ACROSS THE
MID-ATLANTIC. 15Z WV IMAGERY AND RAP DATA SUGGESTS THAT A SMALL
AMPLITUDE SHORTWAVE (OR AN MCV SPAWNED BY UPSTREAM CONVECTION
EARLIER THIS MORNING) IS PRESENT IN VICINITY OF THE CLT METRO AREA.
THIS FEATURE APPEARS TO BE ENHANCING CLOUD COVER ACROSS THE W/SW
PIEDMONT...AND A SLIGHT `SWIRL` IS EVEN DISCERNIBLE IN VIS SAT
IMAGERY. ENHANCED CLOUD COVER ASSOC/W THIS FEATURE IS ALREADY
CREATING A DIFF HEATING BOUNDARY ACROSS THE SW PIEDMONT AND
SANDHILLS...FURTHER COMPLICATING THE FORECAST. REGARDLESS...THIS
FEATURE COULD PROVIDE SUFFICIENT FORCING FOR CONVECTIVE DEVELOPMENT
BETWEEN 16-21Z IN THE SANDHILLS AND SE COASTAL PLAIN...ESPECIALLY
GIVEN MODERATE TO STRONG INSTABILITY AND LITTLE/NO CINH. AT THE SAME
TIME...SUBSIDENCE IN THE WAKE OF THIS FEATURE COULD SUPPRESS
CONVECTIVE DEVELOPMENT IN THE W/NW PIEDMONT THROUGH MID/LATE
AFTERNOON. GIVEN CYCLONIC FLOW ALOFT IT IS CERTAINLY POSSIBLE THAT
ADDITIONAL DISTURBANCES WILL PROGRESS ACROSS THE REGION LATER THIS
EVENING/TONIGHT...THOUGH SUCH FEATURES COULD ALSO RESULT IN
SUBSIDENCE /SUPPRESSED DEVELOPMENT/ DEPENDING ON THE TRACK...TIMING
AND LOCATION. WITH THE ABOVE IN MIND...WILL INDICATE PRECIP CHANCES
RANGING FROM 30-50%...LOWEST IN THE W/NW PIEDMONT AND HIGHEST IN THE
SANDHILLS/SE COASTAL PLAIN.

TEMPERATURES:
EXPECT HIGHS TODAY RANGING FROM THE MID/UPPER 80S IN THE WESTERN
PIEDMONT TO THE LOWER 90S IN THE COASTAL PLAIN...PRIMARILY DEPENDING
ON CLOUD COVER. LOWS TONIGHT SIMILAR TO LAST NIGHT IN THE LOWER 70S.

SEVERE THREAT:
THOUGH DEEP-LAYER SHEAR REMAINS WEAK (15-20 KT) AND SIMILAR TO
YESTERDAY...STEEPER MID-LEVEL LAPSE RATES (6.0-7.0 C/KM)...MODERATE
INSTABILITY...AND A DRIER MID-LEVEL AIRMASS/HIGHER DCAPE (750 TO
1250 J/KG) WOULD SUGGEST MORE ROBUST COLD POOLS AND A BETTER
POTENTIAL FOR DAMAGING WINDS WITH DEEP CONVECTION THIS AFT/EVE.
GIVEN ABOVE NORMAL UNCERTAINTY WITH REGARD TO CONVECTIVE COVERAGE...
THE THREAT WILL BE CONDITIONAL IN NATURE...ESPECIALLY ACROSS THE
N/NW PIEDMONT WHERE THE THERMODYNAMIC ENVIRONMENT WILL BE MORE
SUPPORTIVE BUT CONVECTIVE INITIATION WILL BE MORE QUESTIONABLE. WILL
MENTION A CHANCE OF ISOLD SVR STORMS IN THE HWO ALONG/EAST OF HWY 1
THIS AFT/EVE WHERE DEVELOPMENT APPEARS MORE LIKELY. -VINCENT

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 245 PM MONDAY...

CYCLONIC FLOW ALOFT WILL STRENGTHEN OVER THE CAROLINAS ON TUE AS AN
UPPER LEVEL LOW TRACKS EAST INTO QUEBEC/NEW ENGLAND. THE BEST DPVA
AND HEIGHT FALLS WILL REMAIN WELL NORTH OF CENTRAL NC...THOUGH SMALL
AMPLITUDE DISTURBANCES EMBEDDED IN INCREASINGLY NW FLOW ALOFT WILL
REMAIN POSSIBLE THROUGHOUT THE DAY. IN THE LOWER LEVELS...A
LOW-LEVEL TROUGH AND SFC COLD FRONT IS PROGGED TO TRACK SOUTHEAST TO
THE HWY 1 CORRIDOR BY EARLY AFTERNOON...PROGRESSING SLOWLY SOUTHEAST
TOWARD THE CAROLINA COAST BY MIDNIGHT. ANTICIPATE MODERATE DIURNAL
DESTABILIZATION ALONG/EAST OF HWY 1 ON TUE...WITH AT LEAST MARGINAL
INSTABILITY IN THE NW PIEDMONT. GIVEN A GOOD LOW-LEVEL FOCUS
COINCIDING WELL WITH PEAK HEATING (ALONG/EAST OF HWY 1 AT LEAST)...
CYCLONIC FLOW ALOFT...PWAT VALUES OF 1.50-1.75" AND MARGINAL TO
MODERATE INSTABILITY...WILL INDICATE PRECIP CHANCES RANGING FROM
20-30% N/NW PIEDMONT TO 50-60% IN THE SANDHILLS AND SE COASTAL PLAIN
DURING THE AFTERNOON HOURS...WITH CHANCES DECREASING AND EVENTUALLY
ENDING FROM NW-SE TUE EVENING AS THE FRONT PROGRESSES TOWARD THE
COAST AND A DRIER AIRMASS ADVECTS INTO CENTRAL NC. WILL INDICATE DRY
CONDITIONS AFTER MIDNIGHT. EXPECT HIGHS TUE SLIGHTLY COOLER THAN
TODAY...IN THE MID/UPPER 80S (N/NW) TO LOWER 90S (S/SE). LOWS TUE
NIGHT WILL DEPEND PRIMARILY ON THE TIMING OF THE FRONT...THE
ADVECTION OF A DRIER AIRMASS INTO CENTRAL NC FROM THE NORTH...AND
CLEARING. WILL INDICATE LOWS RANGING FROM THE LOWER/MID 60S N/NW TO
UPPER 60S /NEAR 70F/ S/SE. -VINCENT

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 245 PM MONDAY...

WEDNESDAY THROUGH THURSDAY...THERE IS LITTLE LIFT ON BOTH THE NAM
AND THE GFS BOTH WEDNESDAY AND THURSDAY...WITH ONLY WEAK MID-LEVEL
WAVES MOVING THROUGH IN THE NORTHWEST FLOW ALOFT. PRECIPITABLE WATER
VALUES ARE LOWER THAN HAVE BEEN THE AVERAGE OF LATE...THE HIGHEST
AMOUNTS BEING JUST ABOVE 1.5 INCHES IN THE SANDHILLS AND SOUTHERN
COASTAL PLAIN THURSDAY WHICH IS AT THE HIGH END OF THE NORMAL RANGE
FOR EARLY SEPTEMBER. WHILE MIXED-LAYER CAPE IN THE LOWEST KM IS
1000-1500J/KG MAINLY ALONG AND SOUTH OF U.S. 64 BOTH WEDNESDAY AND
THURSDAY...BUFR SOUNDINGS FROM THE NAM AND GFS ARE GENERALLY STABLE
TO DEEP CONVECTION BOTH DAYS. THE NAM HAS NO QPF WEDNESDAY...WHILE
THE GFS HAS MEAGER QPF IN CENTRAL NORTH CAROLINA OUTSIDE OF THE
TRIAD. WITH THE WEAKENING AND SLOWING INITIAL SURFACE FRONT SOUTH OF
THE AREA WEDNESDAY...WEAK 850MB CONVERGENCE JUST SOUTH OF THE AREA
AS WELL...LITTLE FORCING ALOFT...AND LAPSE RATES ALOFT NEAR OR JUST
TO THE WARM SIDE OF MOIST ADIABATIC ON BUFR SOUNDINGS...THINK THAT
OUTSIDE OF AN ISOLATED SHOWER WEDNESDAY WHICH WOULD BE MORE LIKELY
IF IT WOULD OCCUR TOWARD THE SOUTHEAST...CHANCES FOR PRECIPITATION
SEEM SMALL. WEDNESDAY NIGHT INTO THURSDAY...NAM AND GFS BUFR
SOUNDINGS SHOW SLIGHT COOLING ALOFT LATE AT NIGHT INTO MIDDAY
THURSDAY BEFORE THE MID-LEVELS WARM AGAIN AS THE DAY WEARS ON. WHILE
THE NAM IS AGAIN DRY...THE GFS QPF SHOWS A SMATTERING OF LIGHT
PRECIPITATION IN CENTRAL NORTH CAROLINA IN WHICH AN ISOLATED SHOWER
OR TWO IS PLAUSIBLE LATE IN THE MORNING INTO MID AFTERNOON IF THE
SUBTLE COOLING ON THE KRDU GFS BUFR SOUNDING JUST LEFT OF MOIST
ADIABATIC VERIFIES. WHILE CERTAINLY NOT RULING OUT AN ISOLATED
SHOWER THURSDAY...WILL CONTINUE WITH THE DRY WORDED FORECAST AND A
GRIDDED PRECIPITATION FORECAST OF TEN PERCENT.

HIGH TEMPERATURES WILL BE FORECAST CLOSE TO WHAT THE 1000-850MB
THICKNESSES AND A BLEND OF MOS GUIDANCE WOULD IMPLY...MID 80S TO
AROUND 90 BOTH WEDNESDAY AND THURSDAY. WEDNESDAY NIGHT LOWS WILL BE
IN THE 60S. UNDER A LIGHT WIND AND WITH THE WEAK SURFACE FRONT JUST
SOUTH OF THE AREA...THE AIR MASS SHOULD REMAIN FAIRLY MOIST
PARTICULARLY OVER THE SANDHILLS AND SOUTHERN COASTAL PLAIN. GUIDANCE
IS IN AGREEMENT ABOUT THE POTENTIAL FOR AT LEAST PATCHY FOG
ESPECIALLY EAST OF U.S. 1 LATE WEDNESDAY NIGHT AND THURSDAY MORNING
AND WILL NOTE THIS IN THE FORECAST.

THURSDAY NIGHT THROUGH MONDAY...A GENERAL NORTHWEST FLOW ALOFT
REMAINS IN PLACE DURING THIS PART OF THE LONG-TERM PERIOD...WITH THE
TROUGH AXIS ALOFT OVERHEAD FOR THE WEEKEND. A VERY MODEST INCREASE
IN HEIGHTS ALOFT IS ALLUDED TO TOWARD THE END OF THIS PERIOD IN THE
LONG-TERM GUIDANCE...WITH MAINLY LIGHT WINDS ALOFT. GUIDANCE POPS
ARE IN THE ISOLATED-TO-SCATTERED RANGE...LEAST EARLY WITH A MODEST
TREND HIGHER LATER IN THE PERIOD. THIS SEEMS REASONABLE...AS BEHIND
A SECOND SURFACE FRONT THURSDAY NIGHT SURFACE HIGH PRESSURE BUILDS
IN WHICH SHOULD ALLOW FOR INCREASED STABILITY FOR THE END OF THE
WEEK AND THE START OF THE WEEKEND...WHEN THE FORECAST WILL LARGELY
BE DRY. WILL RETAIN THE SLIGHT CHANCE INHERITED IN THE FORECAST FOR
SATURDAY TOWARD THE YADKIN RIVER...CERTAINLY NOT EXPANDING FURTHER
AS COARSE MODEL SOUNDINGS FROM THE GFS AND ECMWF ARE FAIRLY STABLE
EVEN INTO SATURDAY...BUT THEN MODEST CHANCES INCREASE THROUGHOUT
CENTRAL NORTH CAROLINA SUNDAY INTO MONDAY COURTESY OF A WARMER AIR
MASS WITH A GRADUAL INCREASE IN LOW-LEVEL MOISTURE AND LAPSE RATES
ALOFT ON THE COARSE MODEL SOUNDINGS. WITH NO SIGNIFICANT FORCING
APPARENT REGARDING SURFACE FEATURES OR IN THE MID-LEVELS...ANY DEEP
CONVECTION SHOULD TEND TO BE ISOLATED-TO-SCATTERED AND MAINLY
DIURNAL IN NATURE.

AS HIGH PRESSURE BUILDS IN FRIDAY...THE GRADIENT APPEARS TIGHT
ENOUGH THAT IT COULD BE SOMEWHAT BREEZY INITIALLY WITH MIXING. UNDER
A NORTHEAST FLOW IN THE LOW LEVELS...THE LONG-TERM GUIDANCE HAS BEEN
CONSISTENT SHOWING AT LEAST MODEST UPPER-LEVEL MOISTURE...BOTH OF
WHICH COULD LIMIT THE TEMPERATURE RISE. HAVE TRENDED LOWER WITH THE
HIGHS FOR FRIDAY...AND SOME GUIDANCE SUGGESTS HIGHS WILL STRUGGLE TO
GET TO 80 ESPECIALLY NORTH OF U.S. 64 FRIDAY AFTERNOON. ALSO LOWERED
MINS FOR FRIDAY NIGHT DIRECTLY UNDER SURFACE HIGH PRESSURE AND A
LIGHT WIND EXPECTED...WITH SOME READINGS POSSIBLY INTO THE LOWER TO
MID 50S NORTHEAST OF THE TRIANGLE. EXPECT A GRADUAL WARMING TREND
FOR BOTH HIGHS AND LOWS SATURDAY THROUGH MONDAY...NORMAL TO JUST
ABOVE NORMAL BY THE END OF THE FORECAST PERIOD AS 1000-850MB
THICKNESSES RISE AND FOLLOWING THE TREND OF THE CONSENSUS OF THE
BIAS-CORRECTED TEMPERATURE GUIDANCE.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1130 AM MONDAY...

24-HR TAF PERIOD:
AFTER LINGERING MVFR CEILINGS THIS MORNING LIFT TO VFR BY 16Z...
EXPECT VFR CONDITIONS TO GENERALLY PREVAIL THROUGH EARLY TO MID
AFTERNOON. ANTICIPATE AN INCREASING CHANCE FOR SHOWERS AND
THUNDERSTORMS AT ALL TERMINALS FROM MID/LATE AFTERNOON THROUGH THIS
EVENING...WITH THE RELATIVE BEST CHANCE AT THE RDU/FAY/RWI
TERMINALS. AN ISOLD SVR STORM WITH SFC WIND GUSTS AS HIGH AS 35-50
KT CANNOT BE RULED OUT. OTHERWISE...EXPECT A POTENTIAL FOR SUB-VFR
FOG OR CEILINGS ONCE AGAIN EARLY TUE MORNING (08-14Z).

LOOKING AHEAD:
A CHANCE OF SHOWERS/STORMS WILL PERSIST ON TUE AS A COLD FRONT
TRACKS SOUTHEAST ACROSS CENTRAL NC...WITH THE BEST CHANCE AT THE
EASTERN TERMINALS (RDU/FAY/RWI) DURING THE AFTERNOON AND EARLY
EVENING. ASIDE FROM A SMALL CHANCE FOR FOG AT THE FAY/RWI TERMINALS
AROUND SUNRISE (08-12Z) EACH MORNING...EXPECT VFR CONDITIONS WED-FRI
AS HIGH PRESSURE BUILDS INTO THE REGION. -VINCENT

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...VINCENT
LONG TERM...DJF
AVIATION...VINCENT






AREA FORECAST DISCUSSION

NWS RALEIGH NC

 1224 PM EDT MON SEP 2 2013

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION FROM THE NORTHWEST TONIGHT...
THEN PUSH SLOWLY SOUTHEAST THROUGH THE CAROLINAS ON TUESDAY. IN THE
WAKE OF THE FRONT...HIGH PRESSURE WILL BUILD INTO THE REGION ON
WEDNESDAY AND LINGER THROUGH THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1220 PM MONDAY...

OVERVIEW:
CYCLONIC FLOW ALOFT WILL PERSIST ACROSS THE CAROLINAS AND
MID-ATLANTIC THROUGH TONIGHT AS A POTENT UPPER LEVEL LOW TRACKS
SLOWLY EAST FROM THE UPPER GREAT LAKES TOWARD QUEBEC/NEW ENGLAND. AN
ASSOCIATED COLD FRONT...EXTENDING SOUTHWEST FROM THE LOWER GREAT
LAKES TO THE LOWER MS RIVER VALLEY THIS MORNING...WILL TRACK SLOWLY
SOUTHEAST TO THE SOUTHERN APPALACHIANS TONIGHT.

INSTABILITY:
EXPECT MODERATE TO PERHAPS STRONG DESTABILIZATION BY PEAK HEATING
THIS AFTERNOON AS STEEPER MID-LEVEL LAPSE RATES (6.0-7.0 C/KM)
ADVECT INTO THE REGION FROM THE N/NW ATOP A WARM/MOIST LOW-LEVEL
AIRMASS. A SMALL (BUT NOTICEABLE) DEWPOINT DISCONTINUITY WILL
PERSIST ACROSS THE SANDHILLS AND COASTAL PLAIN TODAY...WITH SFC
DEWPOINTS 73-75F ALONG AND EAST OF A LINE FROM RCZ-FBG-RWI.
INSOLATION COMBINED WITH THE AFOREMENTIONED MOISTURE IN THE
SANDHILLS/SE COASTAL PLAIN HAS RESULTED IN COMPLETE EROSION OF CINH
AND 1500 J/KG MLCAPE AS OF 15Z...AND THIS AREA SHOULD SEE MLCAPE
VALUES OF 2000-3000 J/KG BY PEAK HEATING. IN THE N/NW PIEDMONT...
DESPITE A SLIGHTLY DRIER LOW-LEVEL AIRMASS...STEEPER MID-LEVEL LAPSE
RATES SHOULD CONTRIBUTE TO MODERATE DESTABILIZATION WITH MLCAPE
VALUES OF 1000-2000 J/KG. A DRIER MID-LEVEL AIRMASS ASSOCIATED WITH
THE MODIFIED EML ADVECTING INTO THE MID-ATLANTIC WILL CONTRIBUTE TO
HIGHER DCAPE IN COMPARISON TO PREVIOUS DAYS...RANGING FROM 750-1250
J/KG AT PEAK HEATING...HIGHEST ALONG AND JUST EAST OF HWY 1.

PRECIP CHANCES:
EXTREMELY CHALLENGING FORECAST. SHALLOW CONVERGENCE ASSOCIATED WITH
A LOW-LEVEL TROUGH OVER THE COASTAL PLAIN WILL BE PRESENT THROUGH
EARLY AFTERNOON...THOUGH THIS CONVERGENCE ZONE MAY EFFECTIVELY
RETROGRADE TO THE HWY 1 CORRIDOR LATER THIS AFT/EVE AS LOW-LEVEL
FLOW OVER WESTERN NC BACKS FROM NW-W IN ASSOC/W VERY WEAK HEIGHT
FALLS AND INCREASING CYCLONIC SHEAR VORTICITY ACROSS THE
MID-ATLANTIC. 15Z WV IMAGERY AND RAP DATA SUGGESTS THAT A SMALL
AMPLITUDE SHORTWAVE (OR AN MCV SPAWNED BY UPSTREAM CONVECTION
EARLIER THIS MORNING) IS PRESENT IN VICINITY OF THE CLT METRO AREA.
THIS FEATURE APPEARS TO BE ENHANCING CLOUD COVER ACROSS THE W/SW
PIEDMONT...AND A SLIGHT `SWIRL` IS EVEN DISCERNIBLE IN VIS SAT
IMAGERY. ENHANCED CLOUD COVER ASSOC/W THIS FEATURE IS ALREADY
CREATING A DIFF HEATING BOUNDARY ACROSS THE SW PIEDMONT AND
SANDHILLS...FURTHER COMPLICATING THE FORECAST. REGARDLESS...THIS
FEATURE COULD PROVIDE SUFFICIENT FORCING FOR CONVECTIVE DEVELOPMENT
BETWEEN 16-21Z IN THE SANDHILLS AND SE COASTAL PLAIN...ESPECIALLY
GIVEN MODERATE TO STRONG INSTABILITY AND LITTLE/NO CINH. AT THE SAME
TIME...SUBSIDENCE IN THE WAKE OF THIS FEATURE COULD SUPPRESS
CONVECTIVE DEVELOPMENT IN THE W/NW PIEDMONT THROUGH MID/LATE
AFTERNOON. GIVEN CYCLONIC FLOW ALOFT IT IS CERTAINLY POSSIBLE THAT
ADDITIONAL DISTURBANCES WILL PROGRESS ACROSS THE REGION LATER THIS
EVENING/TONIGHT...THOUGH SUCH FEATURES COULD ALSO RESULT IN
SUBSIDENCE /SUPPRESSED DEVELOPMENT/ DEPENDING ON THE TRACK...TIMING
AND LOCATION. WITH THE ABOVE IN MIND...WILL INDICATE PRECIP CHANCES
RANGING FROM 30-50%...LOWEST IN THE W/NW PIEDMONT AND HIGHEST IN THE
SANDHILLS/SE COASTAL PLAIN.

TEMPERATURES:
EXPECT HIGHS TODAY RANGING FROM THE MID/UPPER 80S IN THE WESTERN
PIEDMONT TO THE LOWER 90S IN THE COASTAL PLAIN...PRIMARILY DEPENDING
ON CLOUD COVER. LOWS TONIGHT SIMILAR TO LAST NIGHT IN THE LOWER 70S.

SEVERE THREAT:
THOUGH DEEP-LAYER SHEAR REMAINS WEAK (15-20 KT) AND SIMILAR TO
YESTERDAY...STEEPER MID-LEVEL LAPSE RATES (6.0-7.0 C/KM)...MODERATE
INSTABILITY...AND A DRIER MID-LEVEL AIRMASS/HIGHER DCAPE (750 TO
1250 J/KG) WOULD SUGGEST MORE ROBUST COLD POOLS AND A BETTER
POTENTIAL FOR DAMAGING WINDS WITH DEEP CONVECTION THIS AFT/EVE.
GIVEN ABOVE NORMAL UNCERTAINTY WITH REGARD TO CONVECTIVE COVERAGE...
THE THREAT WILL BE CONDITIONAL IN NATURE...ESPECIALLY ACROSS THE
N/NW PIEDMONT WHERE THE THERMODYNAMIC ENVIRONMENT WILL BE MORE
SUPPORTIVE BUT CONVECTIVE INITIATION WILL BE MORE QUESTIONABLE. WILL
MENTION A CHANCE OF ISOLD SVR STORMS IN THE HWO ALONG/EAST OF HWY 1
THIS AFT/EVE WHERE DEVELOPMENT APPEARS MORE LIKELY. -VINCENT

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 350 AM MONDAY...

AFOREMENTIONED UPPER LEVEL TROUGH WILL ADVANCE EASTWARD ACROSS THE
NORTHEAST AND NEW ENGLAND STATES ON TUESDAY WITH TRAILING SFC COLD
FRONT MOVING INTO THE AREA TUESDAY AFTERNOON AND OFFSHORE BY TUESDAY
EVENING. WELL REMOVED FROM THE SHORTWAVE TROUGH DYNAMICS AND JET
SUPPORT OVER SOUTHERN NEW ENGLAND COAST...MID AND UPPER LEVEL
SUPPORT OVER THE CAROLINAS WILL BE QUITE DIRE TUESDAY AFTERNOON.
ADDITIONALLY...WEAKENING LOW-LEVEL MOISTURE FLUX CONVERGENCE OWING
TO THE DEEP LAYER WESTERLY FLOW IN PLACE EAST OF THE MOUNTAINS WILL
RESULT IN ISOLATED TO SCATTERED SHOWERS AND STORMS TUESDAY
AFTERNOON...WITH BEST CHANCE AGAIN IN THE EAST DUE TO THE TIMING OF
THE FRONTAL PASSAGE COINCIDING WITH PEAK AFTERNOON HEATING AND
MODERATE DESTABILIZATION. GIVEN WEAK FORCING...SEVERE THREAT WILL
REMAIN LOW WITH ONLY AN ISOLATED STRONG TO SEVERE STORM EXPECTED...
MAINLY ACROSS THE FAR EAST TUESDAY AFTERNOON. HIGHS IN THE MID 80S
WEST TO NEAR 90 ACROSS THE SOUTHEAST.

WEAK HIGH PRESSURE WILL BUILD BEHIND THE FRONT WITH ENSUING N-NELY
WINDS ADVECTING DRIER AND COOLER AIR INTO THE AREA OVERNIGHT. LOWS
IN THE LOWER 60S NW TO UPPER 60S SE.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...

OVERALL THE LONG TERM PERIOD WILL BE CHARACTERIZED BY DRIER
CONDITIONS AS THE WESTERLIES REMAIN WELL NORTH OF THE REGION AND
SURFACE HIGH PRESSURE AND WEAK FLOW ALOFT MOSTLY DOMINATES THE
WEATHER ACROSS CENTRAL NC. THE FRONT THAT IS PROGGED TO MOVE THROUGH
THE AREA ON TUESDAY WILL BE SOUTH OF THE FORECAST AREA BY WEDNESDAY
MORNING...WITH DRIER AIR FILTERING IN BEHIND THE FRONT AS HIGH
PRESSURE BUILDS IN FROM THE NORTHWEST. ANOTHER REINFORCING SHOT OF
STRONGER SURFACE HIGH PRESSURE WILL BUILD OVER THE AREA FRIDAY INTO
SATURDAY AS A SHORTWAVE IN THE WESTERLIES TO OUR NORTH DRAGS ANOTHER
FRONT THROUGH NEW ENGLAND/NORTHERN MID ATLANTIC REGION ON THURSDAY.
GIVEN THE DRIER AIR IN PLACE OVER OUR REGION...AM NOT EXPECTING ANY
PRECIP WITH THE ASSOCIATED WEAK TAIL END OF THE SURFACE TROUGH. THE
NEXT CHANCE OF PRECIP...ALTHOUGH ONLY MINIMAL CHANCES AT BEST...WILL
COME LATE IN THE WEEKEND AS THE SURFACE HIGH SHIFTS OFFSHORE AND
RETURN FLOW GRADUALLY BEGINS TO INCREASE OUR MOISTURE ONCE AGAIN.
TEMPS WILL GENERALLY BE NEAR TO SLIGHTLY BELOW NORMAL THROUGH THE
ENTIRE PERIOD.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1130 AM MONDAY...

24-HR TAF PERIOD:
AFTER LINGERING MVFR CEILINGS THIS MORNING LIFT TO VFR BY 16Z...
EXPECT VFR CONDITIONS TO GENERALLY PREVAIL THROUGH EARLY TO MID
AFTERNOON. ANTICIPATE AN INCREASING CHANCE FOR SHOWERS AND
THUNDERSTORMS AT ALL TERMINALS FROM MID/LATE AFTERNOON THROUGH THIS
EVENING...WITH THE RELATIVE BEST CHANCE AT THE RDU/FAY/RWI
TERMINALS. AN ISOLD SVR STORM WITH SFC WIND GUSTS AS HIGH AS 35-50
KT CANNOT BE RULED OUT. OTHERWISE...EXPECT A POTENTIAL FOR SUB-VFR
FOG OR CEILINGS ONCE AGAIN EARLY TUE MORNING (08-14Z).

LOOKING AHEAD:
A CHANCE OF SHOWERS/STORMS WILL PERSIST ON TUE AS A COLD FRONT
TRACKS SOUTHEAST ACROSS CENTRAL NC...WITH THE BEST CHANCE AT THE
EASTERN TERMINALS (RDU/FAY/RWI) DURING THE AFTERNOON AND EARLY
EVENING. ASIDE FROM A SMALL CHANCE FOR FOG AT THE FAY/RWI TERMINALS
AROUND SUNRISE (08-12Z) EACH MORNING...EXPECT VFR CONDITIONS WED-FRI
AS HIGH PRESSURE BUILDS INTO THE REGION. -VINCENT

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...CBL
LONG TERM...KRR
AVIATION...VINCENT






AREA FORECAST DISCUSSION

NWS BISMARCK ND

 111 PM CDT MON SEP 2 2013

.UPDATE...
ISSUED AT 111 PM CDT MON SEP 2 2013

AS OF 18 UTC...SURFACE HIGH PRESSURE CONTINUES TO PROPAGATE INTO
MINNESOTA...WITH RETURN FLOW ACROSS WESTERN AND CENTRAL NORTH
DAKOTA. NO CHANGES REQUIRED WITH THIS FORECAST UPDATE...OTHER THAN
TO BLEND TO THE OBSERVED TRENDS.

UPDATE ISSUED AT 1014 AM CDT MON SEP 2 2013

NO SIGNIFICANT CHANGES WITH THIS UPDATE AS THE INHERITED FORECAST
IS ON TRACK...WITH ALL FOG BURNED OFF ACROSS WESTERN AND CENTRAL
NORTH DAKOTA.

UPDATE ISSUED AT 645 AM CDT MON SEP 2 2013

PATCHY FOG HAS DEVELOPED FROM PARTS OF THE JAMES RIVER VALLEY
NORTH AND WEST TOWARDS THE TIOGA AREA. THE HRRR SHOWED THIS TO
SOME DEGREE...AND HAVE ADDED A MENTION OF PATCHY FOG IN THE GRIDS
TO COVER THE LOWER VISIBILITIES. WILL CARRY THE FOG THROUGH 14Z
WHICH IS CLOSE TO THE TIMING FROM THE HRRR. MADE SMALL ADJUSTMENTS
TO TEMPERATURES AND DEWPOINTS TO REFLECT CURRENT
CONDITIONS...OTHERWISE THE FORECAST LOOKS ON TRACK.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 315 AM CDT MON SEP 2 2013

TRANQUIL WEATHER WILL HIGHLIGHT THE SHORT TERM FORECAST.

CURRENTLY...SURFACE HIGH PRESSURE CENTER WAS NEAR THE BORDER OF
NORTH DAKOTA/MINNESOTA/MANITOBA WITH THE HIGH AXIS EXTENDING
SOUTHWARD ACROSS THE RED RIVER VALLEY. BROAD LOW PRESSURE WAS OVER
THE LEE OF THE ROCKIES. CLEAR SKIES AND LIGHT WINDS NEAR THE SURFACE
HIGH CENTER HAS ALLOWED TEMPERATURES TO DROP INTO THE 40S OVER MUCH
OF EASTERN AND CENTRAL NORTH DAKOTA. MOST OF THE WESTERN THIRD OF
THE STATE REMAINED IN THE 50S AS OF 3 AM CDT.

SOME OF THE SHORT TERM MODELS HINTED AT LIGHT TO MODERATE FOG...OR
LOW CLOUDS...FROM NEAR BISMARCK TO WILLISTON/MINOT. ALTHOUGH
SATELLITE PICS INDICATE CLEAR SKIES...MANDAN AIRPORT WAS REPORTING
CLOUDS AT 4300 FEET. THINKING THIS IS MORE ISOLATED IN NATURE AND
WILL KEEP CLEAR SKIES IN THE FORECAST TODAY AND TONIGHT.

THE SURFACE HIGH IS FORECAST TO MOVE SOUTHEAST INTO MINNESOTA THIS
EVENING AND TO WISCONSIN/IOWA BY DAYBREAK TUESDAY MORNING. THUS
SOUTH/SOUTHEAST WINDS AT 5 TO 15 MPH SHOULD PREVAIL TODAY. AFTER
YESTERDAY`S HIGHS FROM THE UPPER 60S TO UPPER 70S/NEAR
80...TEMPERATURES SHOULD BE A TAD WARMER TODAY WITH THE COOL HIGH
PRESSURE EXITING THE AREA. LOOKING AT HIGHS FROM THE MID 70S IN THE
TURTLE MOUNTAINS TO JAMES RIVER BASIN...TO THE UPPER 80S IN THE FAR
WEST.

IN ADDITION...LOW TEMPERATURES MONDAY NIGHT WILL ALSO BE HIGHER THAN
REPORTED THIS MORNING...WITH SOUTH WINDS OF AROUND 5 TO 10 MPH
TONIGHT. LOOKING AT LOWS FROM THE LOWER 50S EASTERN PORTIONS OF
CENTRAL NORTH DAKOTA TO THE LOWER 60S WEST.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 315 AM CDT MON SEP 2 2013

THE LONG TERM WILL BEGIN WITH A LARGE RIDGE ACROSS THE
CENTRAL UNITED STATES.  THE 02.00 NAM AND GFS BOTH BRING A WAVE
THROUGH THE H5 RIDGE ON TUESDAY AND MOVE IT ACROSS WESTERN AND
SOUTHERN NORTH DAKOTA TUESDAY INTO TUESDAY NIGHT.  WILL CARRY THE
HIGHEST POPS ACROSS THE SOUTHWEST AND SOUTH...WITH LESSER CHANCES IN
THE NORTH.

THE H5 RIDGE AMPLIFIES AND DOMINATES THE WEATHER OVER THE NORTHERN
PLAINS FROM WEDNESDAY THROUGH THURSDAY NIGHT. THIS WILL BRING
MAINLY DRY WEATHER ACROSS WESTERN AND CENTRAL NORTH DAKOTA. THE
RIDGE BREAKS DOWN TOWARDS THE WEEKEND AS AN UPPER LOW APPROACHES
THE NORTHERN PLAINS FROM THE PACIFIC NORTHWEST. THE CHANCES FOR
RAIN / THUNDERSTORMS WILL INCREASE AS THE UPPER LOW APPROACHES...AND
THE LATEST ALL BLEND MODEL CONSENSUS CAPTURES THIS TREND WELL.
TEMPERATURES WILL ALSO COOL AS THE RIDGE BREAKS DOWN AND THE RAIN
CHANCES INCREASE. WILL SEE HIGHS IN THE MID 80S TO LOWER 90S ON
THURSDAY AND FRIDAY...COOL INTO THE MID 70S TO MID 80S BY SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 111 PM CDT MON SEP 2 2013

VFR CONDITIONS ARE EXPECTED FOR THE 18 UTC TAFS WITH SURFACE HIGH
PRESSURE ACROSS MINNESOTA.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...AYD
SHORT TERM...JV
LONG TERM...CK
AVIATION...AYD







AREA FORECAST DISCUSSION

NWS LA CROSSE WI

 245 PM CDT MON SEP 2 2013

.SHORT TERM...(TONIGHT THROUGH TUESDAY)
ISSUED AT 245 PM CDT MON SEP 2 2013

THICK BLANKET OF CLOUDS ACROSS WI AND PARTS OF EASTERN MN EARLY THIS
AFTERNOON...ON THE BACKSIDE OF A EASTWARD DEPARTING LOW PRESSURE
SYSTEM. THE LATEST HRRR AND SREF POINT TO SOMEWHAT RAPID
DISSIPATION/EXITING EAST OF THIS CLOUD DECK AS THE AFTERNOON WEARS
ON. MUCH OF THIS WOULD BE DUE TO THE MIXING IN OF DRY AIR AS A SFC
HIGH SLIDES IN FROM THE NORTHERN PLAINS. THAT SAID...SATELLITE STILL
DEPICTS THE ORIGINAL CLOUD SHIELD FAIRLY WELL...MORE A
NORTHWEST-SOUTHEAST RUNNING BAND. RAP13/NAM12 RH FIELDS HANG ONTO TO
SOME OF THIS SATURATION OVER NORTHEAST IA/SOUTHWEST WI THROUGH THE
OVERNIGHT. GOING TO SIDE WITH THE CLEARING TREND...HOLDING ONTO
CLOUDS THE LONGEST IN THE SOUTH. ADD A LIGHT NEAR SFC WIND FIELD
INTO THE MIX AND CLIMATOLOGICALLY FAVORED TIME OF YEAR AND RIVER
VALLEY FOG SHOULD DEVELOP...LIKELY BECOMING DENSE AT SOME LOCATIONS.
MOST OF WHAT DEVELOPS SHOULD BURN OFF BY 9-10 AM. THERE IS SOME
CONCERN THAT FOG COULD FORM OUTSIDE OF THE VALLEYS. THERE WAS SOME
FOG TO THE WEST UNDER THE HIGH EARLY THIS MORNING...BUT SOME OF
THIS WAS IN LOCATIONS THAT HAD RECENT RAINS. WE HAVE BEEN
EXCEEDINGLY DRY...AND DESPITE THE DEVELOPING CLEAR SKIES/LIGHT
WINDS...FOG DEVELOPMENT COULD BE INHIBITED BY THE DRY CONDITIONS.
MAY ADD IN SOME PATCHY FOG AREAWIDE. IF NOT...CONDITIONS WILL HAVE
TO BE MONITORED AND ADJUSTMENTS MADE TO FORECAST IF FOG LOOKS MORE
LIKELY. DON/T FEEL A DENSE FOG ADVISORY IS LIKELY. IF IT WOULD HAVE
RAINED RECENTLY...THAT WOULD BE A DIFFERENT STORY.

HIGH PRESSURE AND A COLD/DRY INFLUX OF AIR WILL GET THE SHORTENED
WORK WEEK OFF TO A CHILLY START. 850 MB TEMP ANOMALIES AROUND -1
TODAY INTO TUE MORNING. WITH PLENTY OF RADIATIONAL COOLING FROM
CLEARING SKIES...LIGHT WINDS...AND THE AFOREMENTIONED COLD AIR
ADVECTING IN...LOWS NEAR 40 ARE LIKELY IN SOME OF THE COLD DRAINAGE
AND LOW LYING AREAS OF CENTRAL/NORTH CENTRAL WI. ELSEWHERE 40S TO
NEAR 50 WILL BE THE RULE...ABOUT 10 TO 15 DEGREES BELOW NORMAL.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 245 PM CDT MON SEP 2 2013

A SURFACE HIGH WILL MEANDER SLOWLY SOUTHEAST ACROSS THE
REGION...WHILE AN UPPER LEVEL RIDGE HOLDS TO THE WEST FOR THE
SHORTENED WORK WEEK. MODELS FAVORING KEEPING ANY PERTURBATIONS ALONG
THE UPPER LEVEL FLOW NORTH/SOUTH OF THE FORECAST AREA...THUS DRY
CONDITIONS WILL CONTINUE.

SOME HOPE FOR RAIN TOWARD THE LATER PART OF THE WEEKEND AND EARLY
NEXT WEEK. THE RIDGE AXIS SHIFTS OVER THE UPPER MISSISSIPPI ON
SUNDAY...WITH AN UPPER LEVEL SHORTWAVE ROLLING ACROSS THE RIDGE TOP
MON/TUE...FLATTENING IT OUT. A SFC WARM FRONT WILL SWEEP AHEAD OF
THE UPPER LEVEL FORCING...WITH THE GFS/EC DEVELOPING PCPN WITH THIS
THERMODYNAMIC LIFT ON SUNDAY. PCPN CHANCES WOULD HANG THROUGH MONDAY
UNTIL THE UPPER LEVEL TROUGH AND ITS ASSOCIATED COLD FRONT MOVE
THROUGH LATER ON TUE. SOME DIFFERENCES IN TIMING ON WHEN THE VARIOUS
FEATURES WOULD MOVE IN...AND THUS ON THE PCPN CHANCES. ALL
SAID...IT LOOKS LIKE THE BEST SHOT FOR WIDESPREAD RAIN FOR THE LOCAL
AREA. WILL SIDE WITH THE CONSENSUS SOLUTION FOR PCPN CHANCES FOR
NOW.

TEMPERATURES WILL BE ON A SLOW RISE THROUGH THE WEEK...WITH A COUPLE
FAIRLY WARM DAYS FOR EARLY SEPT ON FRI/SAT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON) ISSUED
AT 1223 PM CDT MON SEP 2 2013

MVFR STRATUS DECK PERSISTS ACROSS THE AREA EARLY THIS AFTERNOON.
SOUNDINGS SHOW THIS MOISTURE/CLOUDS TRAPPED UNDER A VERY STRONG
SUBSIDENCE INVERSION NEAR 875MB...LIMITING MIXING/DISSIPATION OF THE
CLOUD DECKS AT MID-DAY. BASED ON SATELLITE IMAGERY...TRENDED TAFS
THRU 00Z MORE PESSIMISTIC WITH THE CLOUD DECK VERY SLOWLY LIFTING/
MIXING/BREAKING UP. CONCERN IS THESE CLOUDS WILL LINGER INTO THE
EVENING...BUT MODELS/SOUNDINGS INSIST THE TRAPPED LOW LEVEL MOISTURE
WILL ADVECT OUT OF THE AREA BY OR SHORTLY AFTER 00Z.

RATHER DRY AIRMASS ABOVE THE 875MB INVERSION...SO ONCE CLOUDS ARE
GONE...VERY FAVORABLE FOR STRONG RADIATIONAL COOLING TONIGHT WITH
THE SFC-925MB RIDGE AXIS OVER THE AREA AT 12Z TUE. BR/FG EXPECTED TO
FORM IN THE RIVER VALLEYS AND OTHER FAVORED LOW LAYING AREAS IN
ROUGHLY THE 09Z-15Z TIME-FRAME. CLOUDS AND COOLER HIGHS TODAY MAY
MAKE MVFR/IFR CIGS/VSBYS IN BR/FG MORE WIDESPREAD THAN EARLIER
THOUGHT...BUT LEFT THIS AS 1/2SM FG BKN003 AT KLSE FOR NOW GIVEN THE
UNCERTAINTIES OF THE STRATUS DECK DISSIPATION/CLEARING. ONCE ANY
BR/FG WOULD BURN OFF BY MID MORNING...GOOD VFR EXPECTED TUE UNDER
DRY HIGH PRESSURE AND SFC-500MB RIDGING.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

$$

SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION.....RRS










AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 1222 PM CDT MON SEP 2 2013

UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND TUESDAY
ISSUED AT 422 AM CDT MON SEP 2 2013

FORECAST CONCERNS ON CLOUD TRENDS TODAY.

UPPER TROF CONTINUES TO MOVE TO THE EAST THIS MORNING. SAT
IMAGERY SHOWING LOW CLOUDS DROPPING SOUTH THROUGH THE WESTERN
LAKES BEHIND SYSTEM. CLOUDS HAVE HAD A HARD TIME FILLING IN OVER
THE SOUTHERN CWA...ESPECIALLY IN THE EAST WHERE DOWNSLOPE
COMPONENT OF NW WINDS OPENING HOLES. SCATTERED LIGHT SHOWERS
CONTINUE OVER NORTH CENTRAL WI WITH RHI PICKING UP ANOTHER .01
LAST HOUR.

CANADIAN HIGH PRESSURE WILL CONTINUE TO MOVE SOUTHEAST INTO THE
STATE TODAY. INCREASING SUBSIDENCE AND ADVECTION OF DRIER AIR
INTO THE REGION SHOULD WORK TO ERODE THE CLOUDS THROUGH THE DAY.
DECREASING INVERSION HEIGHTS WILL ALSO LIMIT LAKE SUPERIOR CONTRIBUTION
TO THE CLOUDS AND PCPN. GEM REGIONAL AND HRRR APPEAR TO BE
HANDLING CURRENT CLOUD TRENDS AND HAVE LEANED TOWARDS THEIR
THOUGHTS OF CLEARING BY LATER AFTERNOON. WILL CONTINUE TO CARRY
SOME TRACE LIGHT SHOWERS OVER NORTH CENTRAL INTO THE LATER
MORNING. NO SIGNIFICANT CHANGE MADE TO PREVIOUS TEMP FORECAST.

SFC HIGH PRESSURE TO BE CONTROL WEATHER OVER STATE THROUGH TUE.
LOOKING FOR CLEAR SKIES AND LIGHT WINDS. HAVE TRENDED A BIT COOLER
TONIGHT IN THE TYPICAL COOLER LOCATIONS...THOUGH SHOULD SEE SIG
DIURNAL SWING FOR TUE FOR TEMPS TO RECOVER BACK TO NEAR SEASONAL
NORMS.

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY
ISSUED AT 422 AM CDT MON SEP 2 2013

THE UPPER LEVEL RIDGE AMPLIFYING OVER THE WESTERN CONUS IS THE
MAIN FEATURE DURING THIS PART OF THE FORECAST. SURFACE HIGH
PRESSURE OVER THE REGION AT THE START OF THE PERIOD WILL PUSH
SOUTHWARD AS A COLD FRONT MOVES THROUGH WISCONSIN MIDWEEK. ANY
UPPER LEVEL SUPPORT REMAINS FAR TO THE NORTHEAST AND THERE IS
LITTLE MOISTURE AROUND SO A DRY FRONTAL PASSAGE IS EXPECTED.
COOLER CONDITIONS BEHIND THE FRONT SHOULD NOT LAST LONG AS SURFACE
WINDS BECOME MORE SOUTHERLY AND BRING WARMER AIR BACK TO THE AREA.

ANOTHER COLD FRONT AND SOME WEAK SHORT WAVE ENERGY WILL BRING A
CHANCE FOR SHOWERS OR STORMS TO THE AREA...MAINLY EARLY NEXT WEEK.
&&

.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1222 PM CDT MON SEP 2 2013

COMBINATION OF MID-LEVEL CYCLONIC FLOW AND 8H COLD
POOL HAS PROVIDED A SUBSIDENCE INVERSION THAT HAS YET TO BE
BROKEN...THEREFORE KEEPING MAINLY MVFR CIGS ACROSS NE WI. WHILE
SOME BREAKS IN THE CLOUDS ARE EXPECTED WITH SOME CIGS BECOMING
VFR...EXPECT MOST OF THESE CLOUDS TO HANG AROUND TIL SUNSET BEFORE
FINALLY BREAKING UP. A RDG OF HI PRES IS FCST TO BUILD INTO WI
LATER TONIGHT AND BE PARKED OVER THE GREAT LAKES ON TUE. VFR
CONDITIONS SHOULD RULE UNDER MOSTLY CLEAR SKIES.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM.....TE
LONG TERM......MG
AVIATION.......AK







AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 1037 AM MDT MON SEP 2 2013

.UPDATE...
ISSUED AT 1036 AM MDT MON SEP 2 2013

SOME SHOWERS AND A FEW THUNDERSTORMS CONTINUE AT MID MORNING OVER
CENTRAL WYOMING...INTO CONVERSE COUNTY. THE ACTIVITY SHOULD DEVELOP
OVER THE MOUNTAINS BY MIDDAY AND THEN MOVE TO THE NORTHEAST AND
SPREAD OVER THE REST OF SOUTHEAST WYOMING AND INTO THE PANHANDLE
AS THE AFTERNOON PROGRESSES. SHOWERS AND THUNDERSTORMS SHOULD BE
MORE WIDESPREAD OVER MAINLY SOUTHEAST WYOMING LATER TODAY THAN THE
PAST FEW DAYS. PRECIPITABLE WATER VALUES ARE CURRENTLY BETWEEN
0.75 AND 1.00 INCHES AND WILL INCREASE SLOWLY THIS AFTERNOON. THE
MID AND UPPER LEVEL PLUME OF MOISTURE IS OVER THE WEST HALF OF
WYOMING AT MID MORNING. THE BULK OF THAT MOISTURE WAS AHEAD OF A
SHORTWAVE TROUGH MOVING INTO NORTHERN UTAH. AT 16Z...THE SURFACE
TROUGH WAS ALONG THE LARAMIE RANGE WITH FAVORABLE SURFACE
CONVERGENCE TAKING PLACE. THOSE FACTORS WILL AID CONVECTION FOR
LATER TODAY. FURTHER TO THE EAST...THE ATMOSPHERE IS CURRENTLY
CAPPED. THE CAP MAY BE ERODED LATE THIS AFTERNOON SOME AS
TEMPERATURES...HOWEVER...12Z NAM KEEPS THE CAP IN PLACE OVER THE
EAST PART OF THE PANHANDLE. TEMPERATURES WILL ALSO SHOULD BE
WARMER TODAY AND WELL ABOVE NORMAL. IN A RECENT UPDATE MADE MINOR
CHANGES TO THE FIRST PERIOD OF THE PREVIOUS FORECAST.

UPDATE ISSUED AT 649 AM MDT MON SEP 2 2013

MADE MINOR CHANGES TO POP FORECAST TODAY. A FEW SHOWERS HAVE
POPPED UP OVER NORTHERN CARBON COUNTY THIS MORNING ALONG AN
ELEVATED WARM FRONT. THIS FRONT IS PROJECTED TO MOVE NORTHEASTWARD
TODAY. MODELS PLACE THE FRONT OVER CONVERSE COUNTY LATE THIS
MORNING AND NEAR THE SOUTH DAKOTA/WYOMING BORDER MID AFTERNOON.
NOT SURE IS CONVECTION WILL BE SUSTAINED ALONG THE BOUNDARY.
USUALLY ELEVATED CONVECTION WILL SUBSIDE WITHIN A FEW HOURS AFTER
SUNRISE BUT IN CASE IT DOES NOT...ADDED LOW END POPS TO WESTERN
AND NORTHERN PORTIONS OF THE FORECAST AREA THIS MORNING. UNSTABLE
AIR WITH THIS BOUNDARY LENDS SOME CREDENCE TO THE NAM PRODUCING
QPF INTO THE NORTHERN NEBRASKA PANHANDLE THIS AFTERNOON. ALSO OF
NOTE IS THE 08Z HRRR MODEL RUN KICKS OUT PRECIPITATION OVER THE
SOUTHERN PANHANDLE THIS AFTERNOON. AT ANY RATE IT IS LOOKING LIKE
THERE IS AT LEAST SOME POTENTIAL FOR STORMS OVER THE PANHANDLE
LATER TODAY.

&&

.SHORT TERM...(TODAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 440 AM MDT MON SEP 2 2013

WILL START OFF THIS MORNING UNDER CLEAR SKIES IN THE EAST AND
PARTLY CLOUDY TO THE WEST. CLOUD COVER TO INCREASE BY THIS
AFTERNOON WITH A FEW SHOWERS AND THUNDERSTORM TO DEVELOP. THE MAIN
QUESTION IS COVERAGE AND LOCATION OF THUNDERSTORM ACTIVITY. BEST
CHANCES SHOULD BE IN THE WEST WHERE AS SHORTWAVE SHORTWAVE MOVES
OVER THAT AREA. THE WAVE IS CURRENTLY OVER CENTRAL UTAH MOVING
NORTHWARD. THE MAIN QUESTION FOR CONVECTION TODAY IS THE TRACK THE
WAVE WILL TAKE. MODELS GENERALLY TRACKING THE WAVE INTO NE
WYOMING AND THEN INTO WRN SOUTH DAKOTA BUT THE NAM IS SLIGHTLY
FARTHER SOUTH AND TRIES TO BREAK OUT CONVECTION INTO THE NORTHERN
PANHANDLE LATE THIS AFTERNOON. DID ADD SLIGHT CHANCE POPS TO THE
PANHANDLE BUT CONFIDENCE IS NOT HIGH.

THERE WILL BE NO SHORTAGE OF HEATING IN THE EAST AS SUNNY SKIES
WILL ALLOW FOR MAX HEATING...SO ASSUMING MAX HEATING AND SOME
UPPER LEVEL SUPPORT...A THUNDERSTORM OR TWO IS NOT COMPLETELY OUT
OF THE QUESTION. ALSO THE MODELS ARE SHOWING DUE POINTS IN THE
LOWER 50S FOR THE PANHANDLE THIS AFTERNOON. BASED ON 15 TO 20 KT
800 MB WINDS AND 60 TO 70 DEGREE DEW POINTS CURRENTLY OVER
KANSAS...WOULD NOT BE SURPRISED TO SEE DEW POINTS APPROACHING 60
DEGREES IN THE PANHANDLE BY LATE THIS AFTERNOON. THIS COULD ALSO
LEAD TO A GREATER CHANCE FOR THUNDERSTORMS LATE THIS AFTERNOON AND
EVENING AND WOULD INCREASE SURFACE BASED CAPE VALUES ABOVE THE
500 J/KG THE MODELS ARE SHOWING. EITHER WAY THE SHEAR IS ON THE
WEAK SIDE TODAY SO SEVERE THUNDERSTORM POTENTIAL IS MINIMAL AT
BEST.

TEMPERATURES WILL REBOUND TODAY AS THE UPPER LEVEL RIDGE
REESTABLISHES ITSELF OVER THE ROCKIES. TEMPERATURES TODAY WILL
GENERALLY BE 5 TO 10 DEGREES WARMER THAN YESTERDAY ACROSS THE
PLAINS WITH 90S FOR HIGHS. FARTHER WEST TEMPERATURES WILL MAINLY
BE IN THE 80S OUTSIDE OF THE MOUNTAINS. THE HEAT WILL CONTINUE
TUESDAY AND COULD BE THE WARMEST DAY OF THE WEEK FOR MANY
LOCATIONS. MAY SEE A FEW RECORDS BROKEN AS DRY WEST TO NORTHWEST
DOWN SLOPE FLOW SETS UP IN THE WAVE OF THE DEPARTING SHORTWAVE.
COULD SEE A FEW LOCATIONS IN THE PANHANDLE TOUCH 100 DEGREES.
SLIGHTLY COOLER WEDNESDAY ACROSS THE PLAINS BUT STILL LOOKING AT
WIDESPREAD 80S AND 90S FOR HIGHS. CHANCES FOR PRECIPITATION
TUESDAY AND WEDNESDAY WILL BE MINIMAL WITH CHANCES FOR MEASURABLE
PRECIPITATION MAINLY CONFINED TO THE MOUNTAINS.

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 440 AM MDT MON SEP 2 2013

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE FORECAST AREA THROUGH
LATE IN THE WEEK...ALTHOUGH WILL BEGIN TO SHIFT EAST AND GIVE WAY
TO SHORTWAVE TROUGHING OVER THE ROCKIES THROUGH THE WEEKEND.
EXPECTING VERY WARM TEMPS ACROSS THE CWA...WITH MARGINAL CHANCES
FOR AFTERNOON SHOWERS AND THUNDERSTORMS. THE BEST CHANCES WILL BE
FOR THE MOUNTAINS AND NEARBY LOWER ELEVATIONS IN THIS FLOW
PATTERN. LEESIDE SFC TROUGH DEVELOPMENT ON THURSDAY WILL MOVE
EASTWARD AS A WARM FRONT ON FRIDAY. THIS COULD FOCUS MORE SHOWER
ACTIVITY FURTHER EAST IN THE LATE AFTERNOON...BUT RIGHT NOW THE
ENVIRONMENT DOES NOT LOOK THAT GREAT FOR MAINTENANCE OF
THUNDERSTORMS WITH LOW BULK SHEAR VALUES PROGGED. A COOL FRONT
LOOKS TO MAKE ITS WAY SOUTH ACROSS THE FORECAST AREA SATURDAY WITH
BLUSTERY NORTHERLY WINDS IN ITS WAKE...TURNING NORTHEAST BY THE
EVENING. TEMPS WILL BE A FEW DEGREES COOLER BEHIND THE FRONT AS
WELL FOR SATURDAY AND SUNDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1036 AM MDT MON SEP 2 2013

VFR CONDITIONS WILL CONTINUE OVER THE CWA THROUGH THE END OF THE
WEEK. SOME SHOWERS AND THUNDERSTORMS WILL BE OVER SOUTHEAST
WYOMING AND NEARBY PARTS OF THE PANHANDLE THIS AFTERNOON AND
EVENING. SOME OF THOSE STORMS WILL PRODUCE BRIEF WIND GUSTS TO
40 KNOTS AND A PERIOD OF HEAVY RAIN. SOUTH TO SOUTHWEST WINDS WILL
GUST AS HIGH AS 25 KNOTS OVER PARTS OF THE CWA THIS AFTERNOON AND
EARLY EVENING.

&&

.FIRE WEATHER...
ISSUED AT 349 AM MDT MON SEP 2 2013

UPPER LEVEL RIDGE WILL CONTINUE TO BE THE MAIN DRIVER OF WEATHER
CONDITIONS THIS WEEK. HOT DRY CONDITIONS WILL BE THE NORM WITH ONLY
SLIGHT CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS. UPPER LEVEL
RIDGE WILL MAKE FOR LIGHT WINDS THROUGH MOST OF THIS WEEK SO NOT
EXPECTING CRITICAL FIRE WEATHER CONDITIONS. IT WILL BE A BIT
BREEZY OVER SOUTHEAST WYOMING TUESDAY AFTERNOON WITH HUMIDITY VALUES
DIPPING INTO THE 15 TO 25 PERCENT RANGE.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&

$$

UPDATE...WEILAND
SHORT TERM...LIEBL
LONG TERM...RJM
AVIATION...WEILAND
FIRE WEATHER...LIEBL