-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 232233
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
633 PM EDT THU MAY 23 2013

.SYNOPSIS...
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SCATTERED THUNDERSTORMS THIS EVENING WILL GIVE WAY TO SHOWERS AND
MUCH COOLER TEMPERATURES...AS A COLD FRONT CROSSES THE REGION.
COOL AND DRY CONDITIONS CAN BE EXPECTED FOR THE WEEKEND.
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&&

.NEAR TERM /THROUGH FRIDAY/...
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SCATTERED STORMS ARE SLOWLY WEAKENING ACROSS REGION AS LOW LEVEL
INSTABILITY WANES. LITTLE CHANGE TO PREVIOUS FORECAST OTHER THAN TO
ADJUST POPS AND SKY TOWARD CURRENT RADAR TRENDS. ONLY SHOWERS BY 9
PM OR SO WITH STRONG SECONDARY COLD FRONT ACROSS CENTRAL OHIO.
WEAK WAVE NEAR WHEELING WILL PUSH NORTHEAST AND ALLOW FRONT TO
SWEEP THROUGH EARLY TONIGHT. WINDS WILL ABRUPTLY TURN NORTHWEST
AND GUST THROUGH THE NIGHT BEHIND THE FRONT. MUCH COLDER AIR WILL
FLOOD INTO THE REGION WITH SHOWER CHANCES DECREASING TONIGHT INTO
FRIDAY MORNING.

ON FRIDAY RATHER COLD NORTHWEST FLOW WILL KEEP A FEW SHOWERS IN
THE RIDGES OTHERWISE MUCH DRIER AIR AND COLD ADVECTION AT 850 MB
WILL KEEP TEMPERATURES MUCH BELOW NORMAL. SKIES WILL CLEAR ACROSS
THE ENTIRE REGION BY LATE DAY.
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&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
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COLDER AND MUCH DRIER AIR WILL CONTINUE TO RAPIDLY INVADE THE AREA
FRIDAY NIGHT WITH DEW POINTS RAPIDLY DECREASING THROUGH THE 40S
AND INTO THE LOWER 30S AND UPPER 20S BY SATURDAY MORNING. AS WIND
BACKS OFF FRIDAY NIGHT AND THE BOUNDARY LAYER DECOUPLES...CLEAR
SKIES WILL RESULT IN SUPERIOR RADIATIONAL COOLING. AS
SUCH...WIDESPREAD FROST IS LIKELY AND LOCAL FREEZING CONDITIONS
ARE POSSIBLE IN THE COLDER SPOTS.

WITH LITTLE OVERALL PATTERN EVOLUTION FROM FRIDAY NIGHT INTO
SATURDAY NIGHT AND SIMILAR RH PROFILES AND WIND PROFILES...YET
ANOTHER FROSTY NIGHT IS POSSIBLE SATURDAY NIGHT. BY
SUNDAY...SLIGHTLY WARMER 850 MB TEMPERATURES AND A TINY BIT OF
MIXING MAY ALLOW HIGHS TO START TO STRUGGLE UP MORE INTO THE 60S
RATHER THAN STRADDLING 60F ITSELF. FRIES
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&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
DRY WEA IS EXPD THRU THE PERIOD WITH HIGH PRESSURE IN CONTROL. A
WARM FRONT WILL APPROACH THE DISTRICT FOR WEDNESDAY INTO THURSDAY
BRINGING AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS. TEMPS
WL START OUT BLO AVG OVR THE WEEKEND...THEN MODERATE TO SEASONAL
LVLS AS HIGH PRESSURE SHIFTS E OF THE AREA AND FLOW TURNS SRLY.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
GENERAL VFR CONDITIONS CAN BE EXPECTED ACROSS THE PORTS THIS
EVENING WITH SCATTERED SHOWERS AND POSSIBLE THUNDERSTORMS.
MVFR RESTRICTIONS OR BRIEF IFR ARE POSSIBLE WITH THE HEAVIER
SHOWERS. AS A COLD FRONT APPROACHES THE AREA THIS EVENING...WIND
GUSTS ARE EXPECTED TO PICK UP AS WELL AS THE ARRIVAL OF MVFR CIGS.
WINDS WILL VEER TO THE NORTHWEST BEHIND THE FRONT...AND WIDESPREAD
IFR CONDITIONS ARE EXPECTED AFTER MIDNIGHT.

.OUTLOOK.../FRIDAY THROUGH TUESDAY/...
RESTRNS ARE LIKELY WITH REMAINING SHWRS INTO FRIDAY...BUT BLDG HIGH
PRES WL QUICKLY RTN VFR TO AREA PORTS BY FRIDAY AFTN. GENL VFR WL
THEN PERSIST INTO TUESDAY.

&&

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

&&

$$