Area Forecast Discussion
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FXUS61 KPBZ 240513
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
113 AM EDT SUN MAY 24 2015

.SYNOPSIS...
TEMPERATURES WILL CONTINUE TO WARM THROUGH THE HOLIDAY WEEKEND.
THE CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS WILL EXIST
THROUGH MUCH OF THE WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
BOUNDARY LAYER DECOUPLING WILL HELP TEMPERATURES LOWER OVERNIGHT BUT
NOT TO THE EXTENT AS LAST NIGHT AS DEW POINTS SLOWLY BEGIN TO
RISE BY EARLY MORNING WITH SOUTHERLY FLOW. OPTIMAL RADIATION
COOLING IS ALSO UNOBTAINABLE DUE TO THE SHORT NIGHTS. HAVE
GENERALLY GONE WITH SLIGHTLY BELOW MOS GUIDANCE TEMPERATURES
OVERNIGHT.

HIGH PRESSURE WILL CONTINUE TODAY WITH 850MB WARM SOUTHWEST FLOW.
MID LEVEL MOISTURE RETURNS AND INCREASES CLOUD COVERAGE LATER IN
THE DAY. TEMPERATURES WILL RISE TO APPROXIMATELY 5 DEGREES ABOVE
NORMAL.

&&

.SHORT TERM /TONIGHT THROUGH TUESDAY/...
HAVE REMOVED ALL POPS FROM SUNDAYS NIGHT AS WARM FRONT APPEARS TO
MOVE NORTH A BIT WEST OF THE REGION. AS HAS BEEN THE REFRAIN
THROUGH SEVERAL DAYS OF THE FORECAST...IT APPEARS THAT THE SYSTEM
DEVELOPING IN THE PLAINS WILL STAY SLIGHTLY FARTHER TO THE
WEST..AND HAVE THEREFORE PULLED CHANCE POPS MONDAYS AFTERNOON
SLIGHTLY FARTHER TO THE WEST. 12KM TAM SHOWS RAIN MOVING IN
MONDAY AFTERNOON/NIGHT...BUT CONSIDERING THE 4KM NAM DOES NOT SHOW
THIS FEATURE...HAVE DECIDED TO BACK OFF THE GFS/NAM SOLUTION AND
STICK CLOSER TO THE DIURNAL TREND TO PRECIPITATION DEPICTED BY THE
SREF/ECMWF. AS SHORTWAVES CONTINUE TO MOVE UP THE UPPER LEVEL
RIDGE...COVERAGE OF SHOWERS/STORMS ON TUESDAY MIGHT FINALLY EXPAND
ACROSS THE ENTIRE FORECAST AREA. BY THE BEGINNING OF THE WORK WEEK
TEMPERATURES WILL RETURN TO A MID SUMMER PATTERN...WITH HIGHS IN
THE MID 80S AND LOWS IN THE MID 60S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
SOUTHWEST FLOW IS PROGGED ACROSS THE REGION THROUGH MID TO LATE
WEEK. WEAK SHORTWAVES EMBEDDED IN THE FLOW ARE EXPECTED TO BRING
PERIODIC SHOWER AND THUNDERSTORM CHANCES. A MORE ORGANIZED TROUGH
MAY BEGIN TO APPROACH OVER THE WEEKEND.

USED TWEAKED WPC ENSEMBLE BASED GUIDANCE TO SMOOTH OUT
UNCERTAINTY DUE TO MODEL AND TIMING DIFFERENCES OF INDIVIDUAL
FEATURES. TEMPERATURES ARE EXPECTED TO AVERAGE 10 TO 15 DEGREES
ABOVE SEASONAL LEVELS.

&&

.AVIATION /05Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE WILL CONTINUE TO SUPPORT VFR AND LIGHT WINDS THAT
WILL SLOWLY TURN SOUTHERLY INTO SATURDAY.

.OUTLOOK.../SUNDAY THROUGH THURSDAY/...
DISTURBANCES IN SOUTHWEST FLOW WILL BRINGS RESTRICTIONS AT TIMES
LATER MONDAY THROUGH THURSDAY.

&&

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

&&

$$


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