Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 021856
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
256 PM EDT MON MAY 2 2016

.SYNOPSIS...
A COLD FRONT OVERHEAD WILL SLIDE INTO SOUTHEAST PA AND MD THIS
EVENING. SHOWERS AND SCATTERED THUNDERSTORMS WILL POP UP OVER
SOUTHERN PA...AND SOME COULD MAKE GUSTY WINDS. A WAVE OF LOW
PRESSURE ROLLING UP THROUGH THE MID-ATLANTIC ALONG THE OLD FRONT
WILL LEAD TO RAIN AND A FEW THUNDERSTORMS FOR THE SOUTHEAST
TONIGHT. UNSETTLED WEATHER WILL BE IN STORE FOR MUCH OF THE WEEK.
MODERATING TEMPERATURES WILL OCCUR INTO THE MIDDLE OF THE UPCOMING
WEEK...FOLLOWED BY SOME COOL AND SHOWERY CONDITIONS LATER IN THE
WEEK AS A DEEP UPPER LOW MOVES FROM THE UPPER GREAT LAKES TO THE
CENTRAL APPALACHIANS.

&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
CLEARING GETS FILLED IN WITH DIURNAL CU QUICKLY AS IT OCCURS.
FRONT APPEARS TO BE INTO KJST/KSEG AND STILL MOVING S. IT MAY
STALL AS IT REACHES SE PA. SO FAR NO DEEP CONVECTION OCCURRING
ALONG THE FRONT. IT APPEARS TO BE LIMITED BY THE EARLIER CAP AND
THE STRONG SPEED SHEAR IN THE 5-10KFT LAYER. HOWEVER...THE POSS OF
SH/TSRA IS THERE FOR THE LATE AFTN/EVENING AS THE FRONT CONTINUES
TO MOVE S. THE DRY AIR AND CLEARING HAVE ALLOWED TEMPS TO GET INTO
THE 70S IN THE SW/SC AND THE ACTIVE CLEARING IN THE SE WILL ALLOW
THE CURRENT TEMPS IN THE 50S TO POP UP INTO THE 60S AND L70S THERE
TOO. AS WE LOSE HEATING...ANY SH/TSRA SHOULD DIE. BUT THE ENERGY
DRIVING THE STORMS OVER KY WILL BE CROSSING WV/VA AND BRING A GOOD
AREA OF LIFT INTO THE SRN HALF OF THE AREA LATER THIS EVENING.
THUS...MORE RAIN/STORMS ARE EXPECTED.

&&

.SHORT TERM /MIDNIGHT THROUGH 6 PM TUESDAY/...
THE WAVE OF LOW PRESSURE MOVING ALONG THE OLD BOUNDARY WILL SPREAD
RAIN/STORMS INTO THE SE THIRD TO HALF OF THE AREA. THE HEAVIEST
WILL BE IN THE LOWER SUSQ WHERE MODEL QPF IS IN THE 0.5 TO 1 INCH
RANGE. DESPITE OUR VERY RECENT WET SPELL..THIS SHOULD NOT MAKE
ANY WORRIES FOR FLOODING. POPS WILL TAPER OFF TO LITTLE OR NIL NW
OF UNV-IPT. THE MAIN FORCING FROM THE WAVE WILL BE PAST US BY
SUNRISE TUES. HOWEVER...PRESSURE WILL LOWER OVER THE ALLEGHENIES
DURING THE DAY AS HEATING AND CONVECTION WILL RESULT. SOME SCT
SHRA WILL POP OVER THE HIGHER HILLS AFTER MORNING MIXING LIFTS THE
CLOUDS. WILL LEAVE POPS LOWER IN THE E AND HIGHER IN THE W. TEMPS
TUES WILL RUN A FEW DEGREES COOLER THAN TODAY OVER MOST OF THE
AREA AND THUS SLIGHTLY BELOW NORMALS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
WEDNESDAY SHOULD BE MOSTLY CLOUDY BUT MAINLY DRY A WEAK RIDGE OF
HIGH PRESSURE SLIDES EAST ACROSS THE STATE IN THE MORNING.

THE PATTERN TURNS QUITE UNSETTLED FOR LATER WEDNESDAY THROUGH
FRIDAY AS A DEEP...SLOW-MOVING CLOSED LOW DROPS SE ACROSS THE
GREAT LAKES...BEFORE BECOMING SITUATED FROM THE CENTRAL
APPALACHIANS TO THE MID ATLANTIC COAST. LATEST 00Z/06Z OPER/ENS
GUIDANCE IS FAIRLY CONSISTENT IN EVOLUTION/LOCATION OF THIS UPPER
LOW COMPARED TO THE PREVIOUS FEW MODEL RUNS.

LATEST GUIDANCE SUGGESTS THAT A STEADY FEED/PLUME OF MOISTURE
WILL STREAM NWWD AND SPIRAL AROUND THIS UPPER LOW...WITH THE
CURRENT TARGET AREA FOR THE STEADIEST AND HEAVIEST SHOWERS LOCATED
SOMEWHERE ACRS CENTRAL AND NRN PENN...EAST TO THE SUSQ VALLEY.
PLENTY OF TIME TO WORK OUT THE FINER DETAILS FOR THIS MDTLY HEAVY
PRECIP EVENT.

UPPER LOW SLOWLY PROGRESSES EASTWARD AWAY FROM THE REGION LATER
FRIDAY AND OVER THE UPCOMING WEEKEND AS RIDGE WORKS IN FROM THE
WEST. STILL KEPT MENTION OF A SHOWER SE ON SAT. POTENTIAL FOR
ANOTHER WAVE TO BRING CHANCE FOR PRECIP ON SUNDAY...BUT MODEL
CONFIDENCE DECREASES BY THIS TIME.

SO OVERALL...SEASONAL TEMPS MIDWEEK FOLLOWED BY COOLER READING
HEADING INTO THE WEEKEND...THEN A WARMING TREND. NOT MUCH SUNSHINE
TO BE HAD THIS WEEK WITH PLENTY OF CLOUDS AND INTERMITTENT
SHOWERS.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
CONVECTION JUST NOT POPPING ALONG THE FRONT...PERHAPS DUE TO SPEED
SHEAR BETWEEN FL050 AND FL100 AND ALSO A MINOR CAPPING INVERSION
AROUND THAT SAME LEVEL. THERE IS STILL A CHC FOR A TSRA BEFORE
SUNSET IN THE FAR SRN TIER...BUT MAINLY TO THE S OF AOO-JST. KMDT
AND KLNS ARE BREAKING OUT OF THE MIRE NOW AND SOME CONVECTION
COULD FIRE UP THERE BEFORE SUNSET. HOWEVER...AFTER A BRIEF BREAK
IN LIFT/FORCING...THERE IS A WAVE ROLLING UP THE OLD FRONT ACROSS
WV/VA. THE LIFT WILL LIKELY LEAD TO AN AREA OF RAIN AND EMBEDDED
TSRA SLIDING ACROSS THE SERN THIRD OF THE AREA - MAINLY MDT AND
LNS - EARLY TONIGHT. EXPECT IFR/LIFR THERE AND IFR/MVFR
RESTRICTIONS IN JST-AOO-UNV-IPT. AFTER THE WAVE PASSES TO OUR
EAST...THE CLOUDS WILL START TO LIFT. DIURNAL MIXING ON TUES WILL
LEAD TO SOME ISOLD SHRA AROUND THE WRN SITES.

OUTLOOK...

WED...PATCHY AM FOG POSSIBLE. AFTN SHRA POSS...MAINLY E.

THU-FRI...OCNL SHOWERS/RESTRICTIONS POSSIBLE.

SAT...NO SIG WX.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO
LONG TERM...LAMBERT/RXR
AVIATION...DANGELO


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