274
FXUS61 KCTP 310919
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
519 AM EDT MON MAR 31 2025
SYNOPSIS
* LOW PRESSURE IN QUEBEC WILL MOVE NORTHEAST TODAY, WITH THE
TRAILING COLD FRONT BRINGING A RISK OF STRONG TO SEVERE STORMS
TO SOUTHEAST PA LATE THIS AFTERNOON AND EVENING.
* MUCH COOLER TEMPERATURES FOLLOW FOR TUESDAY AND WEDNESDAY AS
HIGH PRESSURE BRINGS SUNSHINE, GUSTY WINDS AND LOW RELATIVE
HUMIDITY TUESDAY AFTERNOON.
* DAILY SHOWER/THUNDERSTORM CHANCES FOLLOW FOR THE SECOND HALF
OF THE WEEK AS ANOTHER LOW TRACKS WEST OF PENNSYLVANIA THROUGH
THE GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY AND THE TRAILING
FRONT STALLS JUST TO THE SOUTH OF PENNSYLVANIA.
NEAR TERM /THROUGH 8PM THIS EVENING/
CLOUD COVER, AN ACTIVE SOUTHERLY BREEZE AND ANOMALOUS SURFACE
DEWPOINTS HAVE CREATED A VERY WARM NIGHT FOR LATE MARCH, WITH
LOWS IN THE MID 50S TO LOW 60S OVER MOST OF THE AREA. THE
BACKDOOR COLD FRONT DRIFTED WEST AGAIN OVERNIGHT, DROPPING
PORTIONS OF SCHUYLKILL, LEBANON, AND DAUPHIN COUNTIES INTO THE
LOW 50S AND UPPER 40S.
A BATCH OF SHOWERS ASSOCIATED WITH A STRONG SHORTWAVE DRIFTING
ACROSS THE GREAT LAKES CONTINUES TO DRIFT NORTHEASTWARD ACROSS
CENTRAL PA THIS MORNING. WITH THE BEST UPPER LEVEL FORCING
LIFTING WELL NORTH OF PA, THESE SHOWERS WILL CONTINUE TO WEAKEN
THIS MORNING. LATEST GUIDANCE INDICATES ACCUMULATION OF A TENTH
TO QUARTER INCH WEST OF I-99 AND IN THE NORTHWEST MOUNTAINS
THROUGH MIDDAY BEFORE THE COLD FRONT SWEEPS THROUGH.
AS THE COLD FRONT DRIFTS SOUTHEAST TODAY ASSOCIATED WITH A STRENGTHENING
SURFACE LOW THAT WILL TRACK NORTH OF PA, IT WILL TAKE A BIT FOR
SHOWERS TO REINTENSIFY THIS AFTERNOON. VERY LITTLE RAIN IS
EXPECTED ACROSS THE CENTRAL RIDGE AND VALLEY REGION. A PRE-
FRONTAL LOW LEVEL JET AND PLUME OF DEEPEST MOISTURE WILL BE OVER
SOUTHEAST PA BY LATE THIS AFTERNOON WITH MIDDAY BREAKS IN THE
CLOUD COVER OVER THE EASTERN HALF OF THE FORECAST AREA HELPING
FUEL DEVELOPING CONVECTION ACROSS PRIMARILY SOUTHEAST PA BASED
ON THE LATEST CAMS. STORMS SHOULD BEGIN TO BECOME MORE
WIDESPREAD AFTER 4PM/20Z.
STRONG MID LEVEL WIND/SHEAR PROFILES, COMBINED WITH EPS CAPES IN
THE 500-1000J/KG RANGE OVER THE LOWER SUSQ VALLEY, SUPPORT THE
POTENTIAL OF SEVERE WEATHER THIS EVENING. THE LATEST SPC SLIGHT
RISK AREA WAS TRIMMED BACK ON THE WEST SIDE, MORE IN LINE WITH
HREF UPDRAFT HELICITY VALUES TARGETING AREAS SOUTHEAST OF I-81
FOR THE BEST POTENTIAL OF ORGANIZED SEVERE CONVECTION.
RELATIVELY MODEST INSTABILITY, COMBINED WITH STRONG FORCING
FAVORING LINEAR RATHER THAN DISCRETE CONVECTION, SUGGESTS
DAMAGING WIND GUSTS ARE THE MAIN THREAT, WITH LARGE
HAIL/ISOLATED TORNADOES MUCH LESS LIKELY. THE THREAT OF SEVERE
WEATHER SHOULD END AROUND 00Z, AS THE COLD FRONT PUSHES
SOUTHEAST OF THE FORECAST AREA.
THERE WILL LIKELY BE A TIGHT GRADIENT OF RAINFALL TOTALS IN
SOUTHEAST PA. AMPLE INSTABILITY AND PWATS OVER 1.25 INCHES
SOUTHEAST OF KMDT SHOULD SUPPORT MORE SUBSTANTIAL RAINFALL IN
THAT AREA, WITH HEAVY DOWNPOURS POTENTIALLY LEADING TO LOCALIZED
AMOUNTS IN EXCESS OF 1.5 INCHES BASED ON SOME HREF MEMBERS.
THIS WOULD BE BENEFICIAL RAINFALL IN A REGION THAT HAS BEEN VERY
DRY. FFG VALUES INDICATE SIGNIFICANT FLOODING IS VERY UNLIKELY.
MONDAY WILL BE THE LAST DAY OF THE UNSEASONABLE WARMTH, WITH
NBM GUIDANCE INDICATING HIGHS RANGING FROM AROUND 60F OVER THE
NW MTNS, TO THE MID 70S ACROSS THE SUSQ VALLEY.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/
A MUCH DRIER NORTHWEST FLOW WILL OVERSPREAD THE REGION TONIGHT BEHIND
THE EXITING COLD FRONT, LEADING TO BREAKING CLOUDS OVER MOST OF
THE REGION AND SOME GUSTY WINDS. LAKE EFFECT STRATOCU ARE
EXPECTED TO LINGER OVER THE ALLEGHENIES THROUGH TONIGHT.
HOWEVER, PROGGED INVERSION HEIGHTS LOOK TOO LOW TO SUPPORT
ANYTHING MORE THAN A FEW LATE NIGHT FLURRIES OVER WARREN/MCKEAN
COUNTIES. SEE NO REASON TO DEVIATE FROM NBM MONDAY NIGHT MIN
TEMPS, WHICH RANGE FROM THE UPPER 20S OVER THE NW MTNS, TO
AROUND 40F ACROSS THE LOWER SUSQ VALLEY. 24 HOUR TEMPERATURE
CHANGES WILL BE ON THE ORDER OF -20F TO -30F ON TUESDAY MORNING
COMPARED TO THIS MORNING.
HIGH PRESSURE AND AN ASSOCIATED LOW-PWAT AIRMASS SHOULD BUILD
INTO THE REGION BEHIND THE EXITING COLD FRONT, RESULTING IN FAIR
AND RELATIVELY COOL WEATHER TUESDAY INTO EARLY WEDNESDAY. GUSTY
WINDS ON TUESDAY MORNING WILL GRADUALLY TAPER OFF THANKS TO A
WEAKENING PRESSURE GRADIENT AS HIGH PRESSURE SETTLES IN.
ABUNDANT SUNSHINE WILL ACCOMPANY A SEASONABLY COOL AFTERNOON
WITH HIGHS IN THE 50S SOUTH AND EAST OF THE I-99/I-80 CORRIDOR
WITH 40S FARTHER WEST AND NORTH. BREEZY AND DRY CONDITIONS COULD
RESULT IN AN ELEVATED RISK OF WILDFIRE SPREAD ON TUESDAY.
PLEASE SEE THE FIRE WEATHER SECTION FOR MORE DETAILS.
UPPER RIDGING CONTINUES TO BUILD FOR TUESDAY NIGHT AS A
DEEPENING SURFACE LOW MOVES INTO THE UPPER MIDWEST. INCREASING
CLOUDS MAY LEAD TO A NICE SUNRISE WEDNESDAY MORNING AS LOWS DROP
WITHIN A FEW DEGREES OF FREEZING AREAWIDE (ABOVE FREEZING SOUTH,
BELOW FREEZING NORTH).
LONG TERM /WEDNESDAY THROUGH SUNDAY/
GUIDANCE THEN TRACKS ANOTHER DEEPENING SURFACE LOW WEST OF PA
THROUGH THE GREAT LAKES ON THURSDAY. SOUTHEAST FLOW AHEAD OF THE
STRONG STORM SYSTEM COULD PRODUCE GUSTY WINDS OF 25 TO 40MPH
WEDNESDAY AND WEDNESDAY NIGHT. RAIN ALONG THE ATTENDANT WARM
FRONT COULD SPREAD INTO CENTRAL PA BY WED PM, WITH A CHANCE OF
SHOWERS ACCOMPANYING THE TRAILING COLD FRONT THURSDAY. A COLD
AIR DAMMING SCENARIO AHEAD OF THE APPROACHING WARM FRONT WITH
SURFACE HIGH EAST OF NEW ENGLAND SUPPORTS UNDERCUTTING NBM MAX
TEMPS SLIGHTLY WED. HOWEVER, MUCH MILDER CONDITIONS ARE LIKELY
THURSDAY, WITH THE REGION POTENTIALLY BREAKING INTO THE WARM
SECTOR SOUTH OF THE SURFACE LOW.
A TRAILING COLD FRONT IS CURRENTLY PROGGED TO STALL OUT JUST
SOUTH OF PA THURSDAY NIGHT. A POTENTIAL WAVE ON THIS BOUNDARY
LOOKS INCREASINGLY LIKELY TO RESULT IN A PERIOD OF RAIN THURSDAY
NIGHT INTO EARLY FRIDAY, ESPECIALLY ACROSS SOUTHERN PA. LATEST
EPS/GEFS SUGGEST A BRIEF PERIOD OF COOL AND DRIER WEATHER IS
LIKELY FRIDAY PM INTO EARLY SATURDAY ASSOCIATED WITH A SURFACE
HIGH PASSING NORTH OF PA. HOWEVER, ANOTHER WAVE OF LOW PRESSURE
APPROACHING FROM THE OHIO VALLEY COULD SPREAD RAIN BACK INTO THE
REGION SATURDAY PM INTO SUNDAY. LATEST ENSEMBLE MEAN QPF BETWEEN
WED PM AND SUN PM IS CLOSE TO 2 INCHES OVER MUCH OF CENTRAL PA,
WHICH WOULD CERTAINLY BE BENEFICIAL GIVEN THE RECENT DRYNESS.
AVIATION /09Z MONDAY THROUGH FRIDAY/
THE LINE OF THUNDERSTORMS THAT MOVED ACROSS OHIO EARLIER HAS
WEAKENED CONSIDERABLY AS IT APPROACHES THE WESTERN AIRFIELDS.
THE WEAKENING TREND WILL CONTINUE AS THE SHOWERS AND STORMS MOVE
INTO A MUCH MORE STABLE ENVIRONMENT OVER PENNSYLVANIA. CEILINGS
ARE LARGELY VFR WITH THE EXCEPTION OF BFD WHERE MVFR CEILINGS
WILL CONTINUE. MVFR CEILINGS WILL BE POSSIBLE AT OTHER SITES AS
SHOWERS MOVE INTO THE REGION.
EXPECT WINDS TO PICK UP FROM THE SOUTHWEST ON MONDAY, AHEAD
OF A COLD FRONT, WITH A SLIGHT RISK OF STRONG TO SEVERE
STORMS. TIMING OF THE FRONT WOULD BE SUCH AT THE SOUTHEAST
SITES LIKE MDT AND LNS HAVE THE HIGHER CHANCE OF A GUSTY
STORM.
NORTHWEST FLOW BEHIND THE FRONT WILL USHER IN MUCH COLDER AIR
ALONG WITH LOW CLOUDS THAT WILL IMPACT BFD AND JST. THERE IS
AROUND A 30% CHANCE THAT MVFR CEILINGS MAKE IT TO AOO, UNV, AND
IPT AS WELL. A COUPLE OF LIGHT RAIN OR SNOW SHOWERS CAN'T
COMPLETELY BE RULED OUT AT BFD AND JST.
OUTLOOK...
TUE...NO SIGNIFICANT WX OR RESTRICTIONS EXPECTED.
WED...RAIN MOVES IN WEST-TO-EAST LATE. RESTRICTIONS LIKELY PM.
THU...MVFR POSS IN WIDESPREAD RAIN SHOWERS. TSRA POSS, MAINLY S.
CFROPA AFTN/EVE.
FRI...MVFR CIGS AND VISBY EXPECTED, MAINLY S.
FIRE WEATHER
COOLER AND DRIER CONDITIONS ARE FORECAST TO START APRIL ON
TUESDAY AS HIGH PRESSURE MOVES ACROSS PA IN THE WAKE OF A COLD
FRONT. DRY AIR WILL SUPPORT RELATIVE HUMIDITIES TUESDAY AFTEROON
FALLING INTO THE 20S ACROSS MOST OF CENTRAL PA. GUSTY NORTHWEST
WINDS ARE ALSO POSSIBLE TUESDAY, BUT AT THIS TIME IT APPEARS THE
STRONGEST WINDS WILL BE IN THE MORNING. LITTLE TO NO RAIN
ACROSS THE CENTRAL RIDGE AND VALLEY REGION WILL LEAVE FUELS
VULNERABLE TO WILDFIRE SPREAD, WHILE PARTS OF SOUTHEAST PA WILL
HOPEFULLY GET ENOUGH RAIN TO LIMIT CONCERN THERE. WILL CONTINUE TO MONITOR
THE FORECAST AND COORDINATE WITH BOF AND ANF FOR ANY POTENTIAL
NEED FOR FIRE WEATHER STATEMENTS.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BANGHOFF
NEAR TERM...FITZGERALD/BANGHOFF
SHORT TERM...FITZGERALD/BANGHOFF
LONG TERM...FITZGERALD
AVIATION...MARTIN/BAUCO
FIRE WEATHER...BANGHOFF/GARTNER
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