Area Forecast Discussion
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FXUS61 KPBZ 011831
AFDPBZ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PITTSBURGH PA
231 PM EDT SUN MAY 1 2016

.SYNOPSIS...
SHOWER CHANCES WILL CONTINUE INTO THE EARLY PART OF THE WEEK WITH
DRIER CONDITIONS THEN RETURNING UNTIL A MID-WEEK SYSTEM.

&&

.NEAR TERM /THROUGH TONIGHT/...
SCATTERING OUT OF CLOUDS HAS ALLOWED FOR AN INCREASE IN
INSTABILITY AS A SOUPY BOUNDARY LAYER HAS REMAINED THROUGHOUT THE
DAY. AN INTERMEDIATE 18Z KILN SOUNDING REVEALED VIRTUALLY NO CAP
IN THE SCATTERED OUT ENVIRONMENT. SHOWERS HAVE POPPED QUITE
QUICKLY POST-SCATTER OUT WITH THUNDER DEVELOPMENT LIKELY NOT FAR
BEHIND. THIS ACTIVITY IS ALL FORMING ALONG A QUASI-STATIONARY
BOUNDARY SPLAYED OUT ACROSS OUR REGION. MODEL CAPES SUGGEST
1500-2000 J/KG WILL BE POSSIBLE INTO THE EVENING WITH MODEST
SHEAR. SPC HAS CONTINUED THE MARGINAL RISK OF SEVERE WEATHER
ACROSS MUCH OF OUR AREA AS A RESULT.

INSTABILITY DOES WANE THIS EVENING...HOWEVER YET ANOTHER WAVE IS
SET TO TRACK DOWN THE FRONTAL BOUNDARY...ALLOWING IT TO SURGE A
BIT NORTHWARD. STRONG DIFFERENTIAL PVA ALONG WITH RIGHT ENTRANCE
REGION DIVERGENCE TRAVERSES THE NORTHERN HALF OF THE CWA OVERNIGHT
AS A RESULT...MEANING A GOOD SWATH OF SHOWERS SHOULD CROSS THE
AREA. POPS WERE ADJUSTED UPWARD AND SLOWED A BIT PER THE CONSENSUS
OF 12Z GUIDANCE WITH THIS FEATURE.

DUE TO THE MOIST AIR MASS IN PLACE WITH VERY HIGH
DEWPOINTS...OVERNIGHT LOWS WILL LIKELY BE FAIRLY WARM FOR EARLY
MAY. FRIES

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
LOW PRESSURE WILL BE OVER NORTHWESTERN PENNSYLVANIA AROUND
SUNRISE...AND SHOULD RACE INTO NEW ENGLAND BY EVENING. WHILE RAIN
WILL DIMINISH QUICKLY DURING THE MORNING WITH THE DEPARTURE OF THE
LOW...A WAVE WILL DEVELOP ALONG THE TRAILING COLD FRONT. THIS WILL
INCREASE THE CHANCE FOR SHOWERS MONDAY NIGHT...BUT THE BULK OF THE
PRECIPITATION WILL REMAIN TO THE SOUTHEAST OF THE REGION. SOME
SHOWERS WILL LINGER TUESDAY...BUT THE REGION SHOULD BE DRY BY
TUESDAY EVENING. THE NEXT GAP IN RAIN WILL BE SHORT AS AN UPPER
LEVEL LOW BEGINS TO DROP OVER THE EASTERN GREAT LAKES. THE NAM IS AN
OUTLIER TO THE WEST...AND HAVE FOLLOWED THE GFS/ECMWF FOR TIMING AND
PLACEMENT OF THE LOW. THIS WILL YIELD INCREASING CHANCE FOR SHOWERS
THROUGH THE DAY ON WEDNESDAY. WITH MOSTLY CLOUDY SKIES THROUGH THE
PERIOD...TEMPERATURES WILL BE AT OR SLIGHTLY BELOW NORMAL.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HAVE GONE WITH LIKELY POPS IN ALL LOCATIONS WEDNESDAY NIGHT WITH THE
UPPER LEVEL LOW OVERHEAD. WEATHER WILL REMAIN COOL...CLOUDY...AND
WET WITH SCATTERED SHOWERS THURSDAY AND FRIDAY BEFORE THE LOW DRIFTS
EAST. SATURDAY SHOULD BE DRY BEFORE ANOTHER COLD FRONT APPROACHES
FROM THE WEST ON SUNDAY. TEMPERATURES WILL REMAIN BELOW NORMAL
THURSDAY AND FRIDAY BEFORE RETURNING TO NORMAL FOR THE WEEKEND.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
LOW CLOUDS ARE RAPIDLY BREAKING UP AS DIURNAL MIXING INCREASES.
WITH A VERY WEAK CAP HOLDING BACK INSTABILITY...INSOLATION WILL
ALLOW FOR RAPID DEVELOPMENT OF SCATTERED SHOWERS AND THUNDERSTORMS.
GIVEN THE SOUPY AIR MASS...THESE WILL POP VIRTUALLY ANYWHERE IN
THE AREA THROUGH THE AFTERNOON. MORE ORGANIZED SHOWERS AND
WIDESPREAD RESTRICTIONS WILL ENCROACH LATER THIS EVENING AND
OVERNIGHT AS A FINAL WAVE MOVES DOWN THE STATIONARY BOUNDARY
ACROSS THE AREA. IFR CONDITIONS WILL BE LIKELY AT MOST SITES INTO
MONDAY MORNING.

.OUTLOOK /MONDAY THROUGH THURSDAY/...
ANOTHER ROUND OF RESTRICTIONS IS LIKELY WITH A WEDNESDAY COLD
FRONT.

&&

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

&&

$$


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