Area Forecast Discussion
Issued by NWS State College, PA

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FXUS61 KCTP 050303
AFDCTP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1103 PM EDT MON MAY 4 2015

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL SAG SOUTHEAST AND BECOME NEARLY
STATIONARY OVER PENNSYLVANIA TUESDAY INTO WEDNESDAY.
NUMEROUS...MAINLY AFTERNOON SHOWERS AND SCATTERED THUNDERSTORMS
WILL OCCUR IN THE VICINITY OF THIS FRONTAL BOUNDARY TUESDAY. HIGH
PRESSURE WILL RETURN FOR THE END OF THE WEEK. MUCH OF THIS WEEK
WILL BE MUCH WARMER THAN NORMAL.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
A FRACTURED AREA OF SHOWERS AHEAD OF THE ADVANCING FROPA IS
PUSHING THROUGHT THE NORTHWEST AND WEST CENTRAL MOUNTAINS LATE
THIS EVENING. OUTFLOW FROM THESE SHOWERS IS REACHING THE CENTRAL
MOUNTAINS...EVIDENCE OF HOW DRY THE BOUNDARY LAYER WAS THIS
AFTERNOON AND CONTINUES TO BE THIS EVENING.

ISOLATED TO SCATTERED COVERAGE OF SHOWERS WILL OVERSPREAD THE
LAUREL HIGHLANDS AND CENTRAL AND NORTH CENTRAL MOUNTAINS
OVERNIGHT. REALLY NOT EXPECTING MUCH QPF OVER WHAT HAS ALREADY
FALLEN OVER THE NORTHWEST WHERE SOME SPOTS SAW 0.1" TO 0.2"...BUT
WILL CONTINUE TO SEE MODERATE RH RECOVERY WHICH IS GOOD FOR FIRE
WEATHER CONCERNS HEADING INTO TUESDAY.

THE AFOREMENTIONED COLD FRONT WILL SETTLE SLOWLY SOUTH THROUGH
THE STATE OVERNIGHT...CONTINUING THE THREAT FOR SHOWERS. WILL
REMOVE THUNDER FROM THE FORECAST OVERNIGHT AS INSTABILITY IS
LACKING. HOWEVER...A RIBBON OF 1.1" TO 1.25" PW WILL LIE ACROSS
THE COMMONWEALTH TO THE SOUTH OF THE FRONT...AND WILL BE THE FOCUS
FOR SOME STEADIER SHOWERS. NOT ANTICIPATING ANY WIDESPREAD OR
HEAVY SHOWER ACTIVITY AT THIS TIME HOWEVER...AS THE DRY AIR
APPEARS TO BE WINNING THIS BATTLE. LOWS EARLY TUESDAY WILL BE
GENERALLY IN THE 50S...OR SOME 10-15 DEG ABOVE NORMAL.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
THE WAVY QUASI EAST/WEST FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY OVER THE AREA TUESDAY...AND THE DUAL TO TRI-LAYERED
CLOUD COVER SURROUNDING IT SHOULD BE BKN-OVC FOR MUCH OF THE
TIME. ANY HOLES AND LOCALIZED ISOLATION THAT OCCUR WILL WORK ALONG
WITH THE HIGH PWAT AIR /IN EXCESS OF 1 INCH/ TO BUBBLE UP SCTD-
NUMEROUS...MAINLY AFTERNOON AND EARLY EVENING SHRA/TSRA WITH BRIEF
DOWNPOURS AND GUSTY WINDS OF 30-40 MPH POSSIBLE.

HIGH TEMPS TUESDAY WILL BE 8-10F COOLER THAN MONDAY ACROSS THE NW
HALF OF THE STATE...BUT JUST 2-5 DEG LOWER THAN THE PRIOR DAY
ACROSS THE SCENT ZONES AND LOWER SUSQ REGION.

BASIN AVG RAINFALL TUESDAY SHOULD BE 2-4 TENTHS WITH LOCALLY OVER
ONE-HALF OF AND INCH WHERE SEVERAL SHRA AND TSRA OCCUR.

MAINLY CLOUDY SKIES...AND LINGERING...MAINLY EVENING
SHOWERS/ISOLATED TSRA ARE IN STORE FOR TUESDAY NIGHT.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
A FRONTAL ZONE STRETCHED FROM THE UPPER MIDWEST TO THE MID ATLC
COAST WILL SERVE AS A FOCUS FOR SCT SHOWERS AND ISOLD TSTMS ON
WEDNESDAY...WITH ADDITIONAL MODEST LIFT PROVIDED BY A WEAK IMPULSE
STREAKING THROUGH ALOFT. THE MODELS SEEM TO AGREE THAT BEST
INSTABILITY AND PWS WILL RESIDE OVER SWRN AND SCENTRAL PA BUT
THERE IS STILL SOME SPREAD IN THE QPF DETAILS. THE LATEST FCST
KEPT CONTINUITY FOR THE MOST PART WITH THE HIGHEST POPS REMAINING
OVER THE SOUTH CENTRAL MTNS AND LAUREL HIGHLANDS. FORCING ALONG
THE BOUNDARY SHOULD WEAKEN INTO THURSDAY AS AN UPPER RIDGE BUILDS
OVER THE EASTERN HALF OF THE NATION.

THE SYNOPTIC PATTERN WILL HAVE A DECIDEDLY SUMMER-LIKE LOOK AND
FEEL THROUGH THE REMAINDER OF THE PERIOD WITH HIGH CONFIDENCE IN
ABOVE NORMAL TEMPERATURES. THE PCPN PATTERN FAVORS ISOLD TO WDLY
SCT DAYTIME HEATING-TYPE SHOWERS AND TSTMS LKLY INITIATING OVER
THE WRN HIGH TERRAIN. A FRONTAL SYSTEM APPROACHING FROM THE GREAT
LAKES AND MIDWEST WILL SUPPORT AN UPTICK IN POPS LATE IN THE PD.

LOW PRESSURE NEAR/ALONG THE SOUTHEAST COAST IS EXPECTED TO STAY
FAR ENOUGH SOUTH AND NOT IMPACT THE AREA WITH PCPN OR ONSHORE
FLOW.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A DYING COLD FRONT WILL PUSH SOUTHEAST INTO THE REGION
OVERNIGHT...ACCOMPANIED BY A FEW SHRA. MAIN AVIATION CONCERN WILL
BE THE POTENTIAL OF LOW CIGS/FOG DEVELOPING OVR THE NW MTNS LATE
TONIGHT...AS PLUME OF LOW LVL MOISTURE ALONG THE FRONT ASCENDS THE
ALLEGHENY PLATEAU. MDL SOUNDINGS INDICATE A POTENTIAL OF IFR CONDS AT
KBFD BTWN 05Z-13Z AND A SLIM CHANCE OF IFR CIGS AT KJST BTWN
11Z-13Z. OTHERWISE...NO SIG RESTRICTIONS EXPECTED...AS ANY
SHOWERS LATE TONIGHT AND TUESDAY AM SHOULD BE LIGHT.

MORE NUMEROUS SHOWERS AND SCTD TSRA WILL DEVELOP TUESDAY
AFTERNOON IN THE VICINITY OF STALLED FRONT LYING ACROSS SOUTHERN
PA. ALTHOUGH VFR CONDS SHOULD PREDOMINATE...BRIEF TSRA IMPACTS
ARE POSSIBLE DURING THE AFTN AND EVENING...MAINLY ACROSS THE
SOUTHERN HALF OF THE STATE.

OUTLOOK...

WED...AM LOW CIGS/FOG POSS KJST. SCT PM TSRA IMPACTS POSS KJST.

THU...AM LOW CIGS/FOG POSS...ESP KJST.

FRI-SAT...ISOLD PM TSRA IMPACTS POSS W MTNS.

&&

.FIRE WEATHER...
STRONG RH RECOVERY HAS TAKEN PLACE EARLY THIS EVENING...WITH ALL
AREAS HAVING RISEN ABOVE 30 PERCENT RELATIVE HUMIDITY AS OF 7 PM
EDT. THEREFORE THE RED FLAG WARNING HAS BEEN CANCELLED ONE HOUR
BEFORE EXPIRATION TIME.

RHS AND CLOUDS WILL STEADILY INCREASE TONIGHT WITH SCATTERED LATE
NIGHT SHOWERS DEVELOPING SOUTH AND EAST ACROSS THE REGION AS A
COLD FRONT SAGS SLOWLY SE FROM THE GLAKES.

THE SHOWERS WILL BECOME MORE NUMEROUS WITH COMPARATIVELY HIGHER RH
VALUES /THAN MONDAY/ DURING THE MIDDAY AND AFTERNOON HOURS
TUESDAY WITH SCATTERED TSRA AS THE FRONT BECOMES NEARLY STATIONARY
ACROSS THE REGION.

&&

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

&&

$$
SYNOPSIS...LAMBERT
NEAR TERM...DEVOIR/LAMBERT
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...FITZGERALD
FIRE WEATHER...


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