Area Forecast Discussion
Issued by NWS State College, PA

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 KCTP 211959
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
359 PM EDT THU MAY 21 2015

.SYNOPSIS...
AN UNSEASONABLY COOL WEATHER PATTERN WILL CONTINUE THROUGH THE
END OF THE WEEK WITH A RATHER CHILLY START TO THE WEEKEND. A
GRADUAL WARMING TREND IS FORECAST THROUGH THE EARLY TO MIDDLE PART
OF NEXT WEEK ALONG WITH AN INCREASING RISK FOR SHOWERS AND
THUNDERSTORMS.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. RADAR
IMAGERY SHOWS THAT SHOWERS HAVE MOVED EAST OF THE STATE FOR THE
TIME BEING. HOWEVER...A SHORTWAVE CURRENTLY MOVING ACROSS THE
OHIO VALLEY WILL LIKELY HELP FIRE SOME MORE SHOWERS ACROSS THE NRN
MTNS AND LAURELS LATE THIS AFTN AND EVENING. LATEST HRRR GUIDANCE
SUGGESTS THOUGH THAT THEY SHOULD REMAIN ISOLATED IN COVERAGE.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY NIGHT/...
THE MAIN LARGE SCALE UPPER TROUGH AXIS IS PROGGED TO ROTATE
THROUGH THE ERN GREAT LAKES AND NRN NEW ENGLAND ON FRIDAY WHICH
SHOULD DRIVE A RE-ENFORCING SFC COLD FRONT THROUGH CENTRAL PA.
MODEL CONSENSUS CONTINUES TO SUGGEST ISOLD/WDLY SCT SHOWERS WITH
THE FRONTAL PASSAGE BUT WITH VERY LIMITED MSTR KEPT POPS AOB 20
PCT. MAX TEMPS SHOULD MODERATE SOME BUT STILL AVG BELOW NORMAL
FOR THIS TIME OF YEAR.

BEHIND THE COLD FRONT ACROSS THE REGION...A SPRAWLING AREA OF
HIGH PRESSURE /1030MB+/ WILL BUILD UNDER A DEVELOPING LARGE UPPER
RIDGE OVER THE REGION. A REINFORCING SHOT OF COLDER AIR AHEAD OF
RIDGE AXIS WILL BRING QUITE CHILLY TEMPS FOR SAT MORNING...WHERE A
FREEZE IS LOOKING MORE LIKELY ACROSS MUCH OF THE NORTHERN MTNS. A
/WELL COORDINATED/ FREEZE WATCH REMAINS IN EFFECT THERE...WITH
SCT FROST EXTENDING INTO THE LAUREL HIGHLANDS AND PORTIONS OF THE
CENTRAL MTNS. POTENTIAL FLY IN THE OINTMENT COULD BE THE
WINDS...THOUGH LIGHT...REMAINING JUST HIGH ENOUGH TO KEEP TEMPS
FROM BOTTOMING OUT COMPLETELY.

THE COLD AIR IS QUICKLY REPLACED BY MODERATING TEMPS ON SAT...AS
HIGHS REBOUND INTO THE 60S UNDER FULL SUN. NOT QUITE AS CHILLY FOR
SAT NIGHT WITH LOWS SETTLING BACK INTO THE 40S IN MOST
LOCALES...UPPER 30S POSS IN THE NW MTNS.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
SUNDAY MARKS BEGINNING OF A ROBUST WARM-UP THAT WILL CONTINUE
THROUGH NEXT WEEK. ALL GUIDANCE SIGNALS THIS WARMING TREND...WITH
HIGH CONFIDENCE IN ABOVE NORMAL TEMPERATURES BY MEMORIAL DAY AS
ANOMALOUS 500MB RIDGE BUILDS OVER THE EASTERN U.S.

SOME DIFFERENCES ON PLACEMENT OF A WARM FRONTAL ZONE LIFTING NWD
FROM THE SRN PLAINS/LWR MS VLY WHICH WILL HAVE IMPACTS ON PCPN
RISK EARLY NEXT WEEK...THOUGH BEST DAILY POPS /HIGH CHANCE TO LOW
LIKELY/ WILL BE OVER THE NW WITH CHANCE POPS IN THE SE.

SLOW EVOLVING FLOW PATTERN GRADUALLY TAKES RIDGE AXIS EASTWARD AS
TROUGH OVER THE CENTRAL PORTION OF THE COUNTY WEAKENS...WITH JET
STREAM RETREATING NORTHWARD AND BECOMING MORE ZONAL. THIS WILL
STRETCH A SLOWLY APPROACHING COLD FRONTAL BOUNDARY MORE W-E...AND
LIKELY REMAINING OFF TO OUR NW. WE/LL REMAIN ON THE VERY WARM AND
MUGGY SIDE OF THE FRONT IN A VERY SUMMER-LIKE PATTERN...KEEPING
DAILY SHOWER/TSTM CHANCES IN THE FORECAST. HIGHS FROM MONDAY
ONWARD WILL RANGE FROM THE UPPER 70S NORTH TO THE MID/UPPER 80S
SE...WITH MILD LOWS IN THE 60S TO AROUND 70 IN THE SE.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
FLOW AROUND AN AREA OF LOW PRESSURE OVER NORTH CAROLINA THIS AFTN
WILL CONTINUE TO SUPPORT A LARGE AREA OF CLOUDS ACROSS PA. MOST
OF THE CIGS ARE...AND WILL REMAIN VFR...BUT UPSLOPE FLOW IS
CAUSING SOME LOWERED CIGS AT KAOO AND KUNV AND IFR AT KJST.
SHOWERS HAVE MOVED EAST OF THE STATE FOR THE TIME BEING.
HOWEVER...A SHORTWAVE MOVING ACROSS THE OHIO VALLEY WILL LIKELY
HELP FIRE SOME MORE SHOWERS ACROSS THE WRN AND NRN MTNS LATE THIS
AFTN AND EVENING....THOUGH THEY SHOULD REMAIN ISOLATED IN
COVERAGE.

IMPROVING FLYING CONDS ARE EXPECTED LATER THIS EVENING...AS WINDS
SHIFT TO THE NW...DRAWING DRIER AIR AND CLEARING SKIES INTO THE
REGION.

HIGH PRESSURE WILL BUILD ACROSS THE REGION FRIDAY INTO THE
WEEKEND.

OUTLOOK...

FRI-SUN...NO SIG WX EXPECTED.

MON-TUE...MAINLY VFR...MVFR POSS IN SHRA/TSRA.

&&

.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR PAZ004>006-010-011-017-037.

&&

$$
SYNOPSIS...GARTNER
NEAR TERM...GARTNER
SHORT TERM...GARTNER/RXR
LONG TERM...RXR/STEINBUGL
AVIATION...FITZGERALD/GARTNER


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.