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 292158
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
558 PM EDT MON JUN 29 2015

.SYNOPSIS...
A SERIES OF DISTURBANCES WILL KEEP PERIODIC RAIN CHANCES THROUGH
MUCH OF THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
SHOWERS ARE EXPECTED TO CONTINUE TO ADVANCE ACROSS THE REGION THIS
EVENING AHEAD OF AN APPROACHING WARM FRONT. A FEW THUNDERSTORMS
ARE POSSIBLE SOUTH OF PIT THOUGH MOST OF THE AVAILABLE INSTABILITY
IS PROGGED TO REMAIN SOUTH OF OUR AREA. ADDITIONAL SHOWERS WILL
REMAIN POSSIBLE AS THE WARM FRONT CROSSES OVERNIGHT...THOUGH WITH
LACK OF LOW LEVEL JET AND SUFFICIENT INSTABILITY LEFT THUNDER OUT
OF THE FORECAST OVERNIGHT.

A RELATIVE BREAK IN THE PRECIP IS EXPECTED TUESDAY MORNING ANOTHER
SHORTWAVE AND ASSOCIATED COLD FRONT APPROACH LATER IN THE
DAY WITH INCREASING SHOWER/STORM CHANCES. MODEL PROGGED SHEAR AND
INSTABILITY ARE MARGINAL...SO THE POTENTIAL FOR STRONG STORMS IS
IN QUESTION.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
BROAD UPPER TROUGH WILL DOMINATE THE EASTERN CONUS THROUGH MID-
WEEK...WITH SEVERAL SHORTWAVE TROUGHS EXPECTED TO MOVE THROUGH
THE FLOW. THUNDERSTORMS ARE EXPECTED AT THE START OF THE TUESDAY
NIGHT PERIOD...BUT THESE SHOULD WANE QUICKLY AS THEIR SUPPORTING
UPPER WAVE DEPARTS AND DRIVES THE ASSOCIATED COLD FRONT SOUTHWARD.

THIS COLD FRONT WILL BECOME STALLED ACROSS THE FORECAST AREA ON
WEDNESDAY...AND LIKELY WILL BE THE FOCUS FOR ADDITIONAL SHOWERS
AND STORMS ON WEDNESDAY AFTERNOON AS MODEST INSTABILITY PERSISTS
IN THE WARM SECTOR...AND ANOTHER SHORTWAVE TROUGH IMPINGES ON THE
REGION.

TEMPERATURES ON WEDNESDAY WILL NOT DEPART MUCH FROM NORMAL VALUES.
AMID INCREASING CUMULUS COVER...HIGHS ARE EXPECTED IN THE UPPER
70S-LOWER 80S...WITH MINIMA IN THE LOWER 60S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
ALTHOUGH THE LONGWAVE TROUGH WILL FLATTEN SOMEWHAT IN THE MEDIUM
RANGE...A PROGRESSIVE PATTERN WILL PERSIST...WITH SEVERAL
SHORTWAVE TROUGHS EXPECTED TO IMPACT THE REGION LATE-WEEK THROUGH
THE WEEKEND. A STALLED FRONTAL BOUNDARY WILL BE DIVERTED QUITE
LITTLE DURING THIS TIME...AND WILL PROVIDE FOCUS FOR DAILY ROUNDS
OF SHOWERS AND STORMS.

MODELS DO NOT AGREE ON DETAILS AT THIS RANGE...BUT THE GENERAL
PICTURE IS THAT A SHORTWAVE TROUGH FROM THE SOUTHERN PLAINS MOVES
ALONG THIS STALLED BOUNDARY LATE IN THE WEEK. THE PRECISE POSITION
OF THE STALLED FRONT WILL DICTATE THE COVERAGE OF ANY ASSOCIATED
PRECIPITATION IN THE PITTSBURGH FORECAST AREA...BUT CONSENSUS
SUGGESTS THAT THE SOUTHERNMOST PORTION OF THE AREA HAS THE
GREATEST LIKELIHOOD OF MEASURABLE RAIN. THUS...POPS WERE ADJUSTED
IN THE LATTER HALF OF THE WEEK TO DEPICT A BIT MORE OF A GRADIENT.

THERE IS NO INDICATION THAT TEMPERATURES WILL DEVIATE FROM
CLIMATOLOGICAL NORMALS BY ANY SIGNIFICANT DEGREE. MAXIMA IN THE
UPPER 70S-LOWER 80S AND MINIMA IN THE LOWER 60S SHOULD BE COMMON
AT LEAST THROUGH THE WEEKEND.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS PERSIST EARLY THIS EVENING...DESPITE LIGHT RAIN
SHOWERS. DRY LOW-LEVELS WILL KEEP RESTRICTIONS LIMITED UNTIL
FURTHER SATURATION OCCURS LATER THIS EVENING. WARM FRONT WILL PASS
LIGHT RAIN MAINLY TO THE NORTH...BUT REMNANT SHOWER AND
THUNDERSTORM ACTIVITY ALONG A MID-LEVEL WAVE WILL MOVE IN LATER
TONIGHT AND OVERSPREAD THE AREA. THE BEST CHANCES FOR ANY
THUNDERSTORMS TO PERSIST ARE ALONG THE SOUTHERN TERMINALS...BUT
CONFIDENCE IS NOT HIGH ENOUGH FOR INCLUSION AT THIS TIME.

EXPECTING MAINLY MVFR CIGS FOR MOST LOCATIONS PRE-DAWN...WITH SOME
IFR ALONG THE NORTH WITH THE DEEPER MOISTURE. CONDITIONS WILL
IMPROVE QUICKLY AFTER SUNRISE TUESDAY...BUT MORE RESTRICTIONS ARE
POSSIBLE IN AFTERNOON SHOWERS/THUNDERSTORMS.

.OUTLOOK.../TUESDAY THROUGH FRIDAY/...
PERIODIC RESTRICTIONS ARE POSSIBLE THROUGH THE WEEK WITH A SERIES
OF CROSSING DISTURBANCES.

&&

.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.