Area Forecast Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPBZ 021153
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
753 AM EDT TUE JUN 2 2015

.SYNOPSIS...
AN UPPER LEVEL LOW WILL NEARLY STALL OVER THE OHIO AND TENNESSEE
VALLEYS THROUGH THURSDAY...WITH RAINFALL CHANCES MAINLY SOUTH AND
EAST OF PITTSBURGH. TEMPERATURES WILL RISE TO MORE SEASONABLE
LEVELS.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE MADE TO MAKE MINOR ADJUSTMENTS TO POPS/DIURNAL TRENDS
THROUGH THIS AFTERNOON. OTHERWISE...FORECAST SEEMS TO BE ON TRACK
AT THE MOMENT.

PREVIOUS...
MODELS WANT TO SHOVE THE PRECIPITATION AND DEEPER MOISTURE
SOUTHWARD THIS MORNING...AS A WEAK UPPER LEVEL RIDGE SQUEEZES IN
FROM THE EAST AND OVER SPREADS THE NORTHERN PORTION OF MY FORECAST
AREA. CONFIDENCE IN THE CLOUD FORECAST IS LOW WITH STILL A GOOD
DEAL OF LOWER MOISTURE SOUTH OF THE AFOREMENTIONED RIDGE AND A
PLETHORA OF SHORTWAVES REVOLVING AROUND THE CUTOFF 500 LOW. HAVE
DECIDED TO GO WITH AN OPTIMISTIC CLOUD FORECAST...AT LEAST FOR THE
NORTHERN HALF OF THE REGION.

OBVIOUSLY CLOUDS WILL BE CRITICAL FOR DAYTIME HIGHS...MAKING FOR A
TRICKY TEMPERATURES FORECAST AS WELL.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
STRONG CONSENSUS EXISTS ON A CLOSED UPPER CYCLONE TRAVERSING THE
TENNESSEE VALLEY EARLY IN THE PERIOD WITH THE LOWER HALF OF THE
TROPOSPHERE AT LEAST FEATURING EASTERLY FLOW OVER THE CWA. THIS
SHOULD ALLOW FOR MOISTURE CREEP INTO AT LEAST THE SOUTHERN HALF OF
THE CWA...AS WELL AS ALLOW FOR SOME INTERESTING WIND FEATURES FOR
WEDNESDAY. MODEL SOLUTIONS FAVOR FAIRLY STRONG EASTERLY FLOW AT
THE RIDGETOPS...WITH STRONG LAPSE RATES BELOW THE RIDGETOPS AND A
STABLE LAYER NEAR THE RIDGETOPS. THIS SEEMS AS THOUGH IT WOULD BE
CONDUCIVE TO DOWNSLOPE WIND GUSTS ON WEDNESDAY. THERE DOES NOT
SEEM TO BE ENOUGH MOMENTUM IN THE COLUMN FOR THEM TO BE OF MUCH
CONCERN...HOWEVER EASTERLY GUSTS OF 20-30 KTS WOULD SEEM PLAUSIBLE
IN WESTMORELAND AND FAYETTE COUNTIES.

IN GENERAL...THE PATTERN EVOLVES VERY SLOWLY THROUGH THE REMAINDER
OF THE WEEK AS THE UPPER LOW OVER THE SOUTHEAST SLOWLY MIGRATES
TOWARD THE COAST AND EVENTUALLY WEAKENS. THIS SLOWLY TURNS OUR LOW
LEVEL FLOW FROM THE EAST TO THE NORTHWEST BY LATE IN THE WEEK.
THIS FLOW CHANGE WILL ALLOW FOR A BIT OF COLDER AIR ALOFT TO RUN
INTO THE AREA...INCREASING LAPSE RATES BY FRIDAY...WHICH SHOULD
ALLOW FOR A CHANCE OF SHOWERS AND THUNDERSTORMS.

TEMPERATURES THROUGH THE SHORT TERM INDICATE A WARMING TREND AS
STRATUS FINALLY GIVES WAY TO BETTER MIXING AND MORE INSOLATION AS
THE UPPER LOW LOSES ITS DEFINITION. FRIES

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODEL AND ENSEMBLE GUIDANCE CONTINUES TO FAVOR THE PASSAGE OF A
NORTHWESTERLY COLD FRONT ON SATURDAY...WHICH SHOULD FINALLY BRING
A DRIER PERIOD WITH AMPLE SUNSHINE BEHIND IT. HOWEVER...THE
IMPROVED CONDITIONS WILL LIKELY BE SHORT-LIVED AS THE CONSENSUS
FAVORS CYCLONIC FLOW REESTABLISHING ITSELF OVER THE CWA BY EARLY
NEXT WEEK...MEANING A SOUTHERLY DROPPING OF THE JET AXIS AND
A BETTER CHANCE THE STRONG TRACK WOULD FAVOR WET CONDITIONS AGAIN
BY EARLY NEXT WEEK. FRIES

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
IMPROVEMENT TO LOW MVFR IS OCCURRING ALMOST EVERYWHERE THIS
MORNING. HOWEVER...WITH THE UPPER LOW REMAINING SITUATED OVER THE
SOUTH...AND RIDGING ALOFT...WE MAY BE IN A STRATUS DECK FOR MOST
OF THE DAY. WILL OFFER AN OPTIMISTIC FORECAST WHICH BRINGS MOST
SITES TO VFR THIS AFTERNOON...BUT CONFIDENCE IS LOW.

.OUTLOOK.../TUESDAY THROUGH SATURDAY/...
CONDITIONAL RESTRICTIONS ARE EXPECTED INTO LATE WEEK AS UPPER
TROUGH REMAINS ENTRENCHED OVER THE EASTERN U.S.

&&

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

&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.