-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KPBZ 161905
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
305 PM EDT THU MAY 16 2013

.SYNOPSIS...
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A COLD FRONT EXTENDING FROM MORGANTOWN TO ZANESVILLE WILL PUSH
SOUTH TONIGHT. THIS BOUNDARY WILL BE STATIONARY FRIDAY THEN WAVER
OVER PORTIONS OF THE UPPER OHIO VALLEY INTO THE WEEKEND.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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WEAK IMPULSE MOVING ALONG BOUNDARY NEAR THE MASON DIXON LINE INTO EASTERN
OHIO WILL BRING LOW CHC POPS SOUTH OF I-70 THIS EVENING. MID DECK
AND DIURNAL CU ELSEWHERE SOUTH OF I-80 WILL SLOWLY DECREASE
TONIGHT. MUCH LOWER DEW POINTS WORKING SOUTH ACROSS REGION BEHIND
FRONT AS BUBBLE OF HIGH PRESSURE WORKS EST ACROSS NEW ENGLAND. LOW
TONIGHT A NEAR EVEN BLEND OF GFS/NAM MOS.

THE FRONT WILL STALL ACROSS WEST VIRGINIA FRIDAY WITH DRY AIR
ENCOMPASSING MUCH OF THE REGION. SCATTERED SHOWERS STILL POSSIBLE
ACROSS THE FAR SOUTH. PARTLY TO MOSTLY SUNNY SKIES ACROSS ALL BUT
THE FAR SOUTH CLOSER TO THE FRONT. NAM MOS SEEMS TOO COOL FOR MAX
TEMPS BUT DID GO A DEGREE OR TWO BELOW GFS MOS IN WEAK COLD
ADVECTION.
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&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
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FOR FRIDAY NIGHT INTO SUNDAY GENERAL AGREEMENT THAT BOUNDARY WILL
PUSH NORTHWARD BUT AGAIN DISAGREE ON TIMING AND STRENGTH OF
POSSIBLE SHORTWAVES. IF GFS IS MORE CORRECT SOUTHERN STREAM ENERGY
WOULD WORK TOWARD THE REGION LATER SATURDAY INTO EARLY SUNDAY WITH
HIGHER RAIN CHANCES. NOT MUCH CONFIDENCE IN THIS. SO TRENDED
TOWARD NAM SOLUTION WITH HIGHEST SHOWER CHANCES ACROSS THE SOUTH
AND RIDGES THROUGH THE WEEKEND. TEMPERATURES NOT FAR FROM GFS MOS.
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&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
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MODEL AGREEMENT ON THE OVERALL UPPER LEVEL PATTERN IS BEGINNING TO
IMPROVE...AT LEAST THROUGH DAY 6 BEFORE THERE ARE GLARING
DIFFERENCES. IN GENERAL...UPPER LEVEL RIDGING WILL CONTINUE TO
AMPLIFY OVER THE EASTERN HALF OF THE CONUS AS A CUTOFF LOW DEVELOPS
OVER THE NORTHERN PLAINS. THIS LOW WILL SLOWLY MAKE IT`S APPROACH
THROUGH THE PERIOD...HELPING TO SWING AN ASSOCIATED FRONT ACROSS THE
REGION BY LATE WEDNESDAY/EARLY THURSDAY. HOWEVER...DIFFERENCES STILL
REMAIN IN THE AMOUNT OF CONVECTIVE ACTIVITY THERE WILL BE IN THE
WARM SECTOR SUNDAY THROUGH WEDNESDAY AS DIFFERENT SHORTWAVES MOVING
THROUGH THE UPPER LEVEL FLOW ARE TIMED DIFFERENTLY FROM RUN TO RUN.
TO TAKE INTO ACCOUNT THESE DIFFERENCES...OPTED TO REMAIN
CONSERVATIVE WITH POPS UNTIL LATE TUESDAY BEFORE INCREASING CHANCES
IMMEDIATELY AHEAD OF THE COLD FRONT. TEMPERATURES WERE ALSO KEPT
BELOW MOS GUIDANCE...ESPECIALLY ON TUESDAY AND WEDNESDAY AS AMPLE
MOISTURE AND CLOUD COVER WILL LIKELY KEEP TEMPERATURES FROM REACHING
THE MID 80`S SUGGESTED.
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&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
STATIONARY BOUNDARY REMAINS RIGHT AROUND KMGW THIS AFTERNOON.
HOWEVER...A SECOND SHORTWAVE SHOULD HELP TO PUSH IT FURTHER SOUTH
ALLOWING FOR WINDS TO SHIFT W-NW AT ALL TAF SITES AND HELP CLEAR OUT
ANY LINGERING MVFR CIGS AT KLBE. THERE COULD BE ADDITIONAL RAIN
SHOWERS NEAR KMGW/KLBE THIS AFTERNOON AS SHORTWAVE CROSSES...HOWEVER
WILL KEEP THIS OUT OF THE TAFS AS IT SHOULDN`T CAUSE MUCH IN THE WAY
OF RESTRICTIONS.

WHILE MOST OF THE TAF SITES SHOULD REMAIN VFR OVERNIGHT WITH CLEAR
SKIES AND CALM WIND...MGW AND ZZV COULD EXPERIENCE SOME FOG
RESTRICTIONS WITH THEIR CLOSER PROXIMITY TO THE STATIONARY BOUNDARY
AND RECENT RAINFALL HELPING TO SATURATE LOWER LEVELS. FOR NOW...JUST
MADE AN MVFR FOG MENTION...WHICH IS WHAT IS SUGGESTED BY THE LAMP
AND SREF.

VFR CONDITIONS SHOULD RETURN AT ALL SITES FRIDAY WITH LIGHT AND
VARIABLE WINDS.

.OUTLOOK.../FRIDAY NIGHT THROUGH TUESDAY/...
GENERAL VFR SHOULD CONTINUE UNTIL SATURDAY AFTERNOON BEFORE BETTER
INSTABILITY AND MOISTURE BRING INCREASING CHANCES FOR
SHOWERS...THUNDERSTORMS...AND SOME RESTRICTIONS THROUGH TUESDAY.

&&

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

&&

$$