864
FXUS61 KCTP 210902
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
502 AM EDT SAT MAR 21 2026
WHAT HAS CHANGED
DENSE FOG ADVISORY FOR A PORTION OF EAST-CENTRAL PA UNTIL 8AM
SEVERE THUNDERSTORM RISK LEVEL INCREASED FROM 1 TO 2 FOR SUNDAY
OVER SOUTH CENTRAL PA
KEY MESSAGES
1) LOW VISIBILITY IN DENSE FOG COULD MAKE DRIVING HAZARDOUS
EARLY THIS MORNING ACROSS PORTIONS OF EAST-CENTRAL PA
2) FIRST WEEKEND OF SPRING WARMUP PRECEDES RAIN AND SEVERE
THUNDERSTORM RISK SUNDAY AFTERNOON INTO SUNDAY NIGHT
DISCUSSION
KEY MESSAGE 1: LOW VISIBILITY IN DENSE FOG COULD MAKE DRIVING
HAZARDOUS EARLY THIS MORNING ACROSS PORTIONS OF EAST-CENTRAL PA
TEMPORARY CLEARING IN THE WAKE OF YESTERDAYS RAINFALL HAS
RESULTED IN PATCHY TO LOCALLY DENSE FOG FORMATION ACROSS
PORTIONS OF EAST CENTRAL PA. VISIBILITY TRENDS HAVE BEEN
IMPROVING ON THE MARGIN UPON THE ARRIVAL OF LOWER CLOUD DECK
CONTINUING TO EXPAND SOUTHEASTWARD PER IR SATELLITE IMAGERY.
COORDINATED WITH PHI ON ISSUANCE OF DFA UNTIL 8AM WITH SEVERAL
ASOS AND RWIS SITES REPORTING VISBY BELOW 1000FT OR <1/4 MILE.
KEY MESSAGE 2: FIRST WEEKEND OF SPRING WARMUP PRECEDES RAIN AND
SEVERE THUNDERSTORM RISK SUNDAY AFTERNOON INTO SUNDAY NIGHT
A NICE START TO SPRING THIS WEEKEND WITH FCST HIGHS RAMPING 15
TO 30F ABOVE THE HISTORICAL AVERAGE BY SUNDAY. THIS SURGE OF
WARMTH WILL BE BRIEF AND FOLLOWED BY A NOTICEABLE COOLDOWN ON
MONDAY WITH MAX TEMPS 20-30 DEGREES LOWER THAN SUNDAY.
SPC EXPANDED THE LEVEL 2/SLIGHT RISK OUTLOOK FROM THE UPPER
OHIO VALLEY INTO SOUTH CENTRAL PA (SOUTH OF I-80) FOR SUNDAY
AFTERNOON AND EVENING. CAPE AND 0-6KM SHEAR PROFILES APPEAR
RATHER FAVORABLE FOR ORGANIZED SEVERE STORMS AHEAD OF A
SOUTHEASTWARD ADVANCING COLD FRONT. LARGE HAIL PROBS ARE
RELATIVELY HIGH WITH 700-500MB LAPSE RATES 7-7.5 C/KM AND
ESSENTIALLY MATCH THE DAMAGING WIND PROBS.
SECONDARY FRONTAL WAVE DEVELOPMENT NEAR THE DELMARVA/SRN NJ
SHOULD HOLD UP THE COLD FRONT AND ALLOW COLDER TEMPS TO
BLEED/CREEP SOUTHWARD LATE SUNDAY NIGHT INTO MONDAY MORNING.
THIS SHOULD RESULT IN A RAIN/SNOW MIX OR CHANGEOVER TO WET SNOW
ALONG THE NORTHERN EDGE OF THE FRONTAL PRECIP BAND AS IT EXITS
THE AREA. A COATING OF SNOW UP TO 0.5" IS MOST LIKELY ON NON-
PAVED SFCS ACROSS THE NORTHERN TIER BY 12Z MONDAY. HIGH TEMPS
ON MONDAY ARE PROJECTED TO BE 20 TO 30 DEGREES COLDER THAN
SUNDAY, PUNCTUATED BY A CHILLY AND BRISK/GUSTY NW WIND.
THE REST OF NEXT WEEK SHOULD FEATURE MORE TEMPERATURE SWINGS UP
AND DOWN WITH OCCASIONAL LIGHT PRECIP. THE BEST PRECIP SIGNAL IN
THE 21/00Z MODEL CYCLE IS IN THE LATE THURSDAY/THURSDAY NIGHT
TIMEFRAME.
AVIATION /08Z SATURDAY THROUGH WEDNESDAY/
RAIN HAS EXITED THE AREA THIS EVENING WITH SOME PATCHES OF
CLEARING ALLOWING FOR SOME PATCHES OF LOCALLY DENSE FOG
FORMATION ACROSS CENTRAL PENNSYLVANIA. THE HIGHEST PROBABILITY
FOR RESTRICTIONS WILL LIKELY REMAIN AT BFD WHERE AMPLE LOW-LEVEL
MOISTURE HAS ALLOWED FOR A FAIRLY PERSISTENT IFR CLOUD DECK
THAT IS EXPECTED TO PERSIST THROUGH 12Z SAT WITH HIGH
CONFIDENCE. THE NEXT AIRFIELDS PROGGED FOR IFR RESTRICTIONS
WOULD LIKELY BE AT JST/LNS WHERE SOME PATCHES OF CLEARING WILL
ALLOW FOR FOG FORMATION. THERE WILL REMAIN A NON-ZERO
PROBABILITY IN IFR RESTRICTIONS AT THE REST OF CENTRAL PA'S
AIRFIELDS DUE TO RECENT RAINFALL AND SOME CLEARING; HOWEVER, AT
IPT/UNV THERE IS LOWER CONFIDENCE IN WIDESPREAD LONG-DURATION
IFR RESTRICTIONS AS A MORE EXPANSIVE LOW-LEVEL CLOUD DECK
~3000FT AGL IS MOVING ACROSS THE AREA, WITH ANOTHER AREA OF LOW-
LEVEL (STILL VFR) CLOUD DECKS TRAVERSING THE SUSQUEHANNA VALLEY
AND BEGINNING TO MAKE IT INTO MDT. THAT BEING SAID, MOST
UNCERTAINTY WITH RESPECT TO THE VISIBILITY/CEILING FORECAST IS
HONED IN IN THE NEXT SIX HOURS, SO AVIATORS WILL NEED TO MONITOR
CURRENT FORECAST/OBSERVATIONAL TRENDS ACROSS CENTRAL PA.
WIDESPREAD IMPROVEMENT TOWARDS VFR IS EXPECTED AFTER 12Z
SATURDAY FOR THOSE AIRFIELDS THAT EXPERIENCE RESTRICTIONS
OVERNIGHT. BFD/JST/LNS ARE MORE LIKELY TO REMAIN DOWN INTO THE
MORNING HOURS BEFORE LOW-LEVEL CLOUD DECKS AND ANY FOG FORMATION
WILL MIX OUT LEAVING A BROKEN DECK OF MID-TO-HIGH LEVEL CLOUDS.
FAIRLY HIGH CONFIDENCE WITH RESPECT TO ALL AIRFIELDS PREVAILING
VFR AFTER 15Z SATURDAY AND THROUGH THE END OF THE 06Z TAF
PACKAGE.
OUTLOOK...
SUN...RAIN OVERSPREADS NORTH TO SOUTH, RESTRICTIONS POSSIBLE.
MON...RAIN GRADUALLY TAPERS OFF NORTH TO SOUTH, TRANSITION TO
SNOW POSSIBLE MAINLY NORTH OF I-80 (BFD/IPT). RESTRICTIONS
POSSIBLE WITHIN RAIN/SNOW SHOWERS.
TUE...MAINLY DRY WITH VFR CONDITIONS. SLIGHT CHANCE OF SNOW
SHOWER ACROSS NORTHERN PA LATE WHICH COULD BRING SOME
RESTRICTIONS.
WED...RAIN AND SNOW SHOWERS ACROSS NORTHERN PA WITH
RESTRICTIONS POSSIBLE.
CLIMATE
DAILY RECORD HIGH TEMPERATURES FOR MARCH 22:
HARRISBURG 80 IN 1938
WILLIAMSPORT 82 IN 1938
ALTOONA 81 IN 1966
STATE COLLEGE 80 IN 1938
CTP WATCHES/WARNINGS/ADVISORIES
DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR PAZ028-
049>053-056>059-063>066.
WHAT HAS CHANGED...STEINBUGL
KEY MESSAGES...STEINBUGL
DISCUSSION...STEINBUGL
AVIATION...BEATY
CLIMATE...STEINBUGL
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