501
FXUS61 KCTP 200648
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
248 AM EDT TUE OCT 20 2026
WHAT HAS CHANGED
* NO CHANGES
KEY MESSAGES
1) EXTENDED STRETCH OF DRY AND SEASONABLE WEATHER THIS WEEK
DISCUSSION
KEY MESSAGE 1: EXTENDED STRETCH OF DRY AND SEASONABLE WEATHER
THIS WEEK
10 PM UPDATE...
DEWPOINTS ARE RECOVERING OVER THE NW FROM MID-AFTERNOON DEPTHS.
SOME FOG IS POSSIBLE TONIGHT IN THE VALLEYS, BUT THE DRYNESS OF
THE AIRMASS DOES ARGUE AGAINST IT. WITHOUT REAL SUPPORT TO
REMOVE THE SMALL MENTION OF PATCHY FOG IN THE GRIDS, WE'LL JUST
KEEP IT IN THERE.
PREVIOUS DISCUSSION...
PERSISTENT HIGH PRESSURE OVER THE NORTHEAST U.S. WILL PROVIDE
AN EXTENDED STRETCH OF DRY AND SEASONABLE WEATHER THIS WEEK.
TONIGHT WON'T BE AS COLD AS THE PAST FEW NIGHTS HAVE BEEN, BUT
WE SHOULD STILL SEE TEMPERATURES DROP INTO THE UPPER 30S AND LOW
40S. PATCHY FROST WILL BE POSSIBLE IN THE COLDEST SPOTS, BUT
NOT IN THE AREAS WHERE THE GROWING SEASON IS STILL ACTIVE. THE
LATEST MODEL DATA SHOWS THE DRY SPELL CONTINUING INTO THE FINAL
WEEK OF OCTOBER. THIS RAIN- FREE PATTERN WILL FEATURE A STRING
OF SUNNY AND SEASONABLY WARM AFTERNOONS WITH LOW HUMIDITY
FOLLOWED BY CLEAR AND CHILLY MOONLIT NIGHTS WITH AREAS OF FROST.
AVIATION /06Z TUESDAY THROUGH SATURDAY/
HIGH PRESSURE AND VERY DRY AIR ARE ALLOWING FOR CONTINUED DRY
CONDITIONS AND CLEAR SKIES ACROSS THE MAJORITY OF THE FORECAST
AREA THIS EVENING. SOME VALLEY FOG ACROSS NORTHWESTERN
PENNSYLVANIA IS STARTING TO FORM BASED ON ECONUS NIGHTTIME
MICROPHYSICS; HOWEVER, FOG CONTINUES TO REMAIN WEST OF ALL
CENTRAL PENNSYLVANIA AIRFIELDS. CURRENT THINKING BASED ON
OBSERVATIONS AND MODEL GUIDANCE IS THAT FOG MAY MAKE A CLOSER
APPROACH TO BFD CLOSER TO SUNRISE BUT OVERALL EXPECTING VFR
CONDITIONS TO CONTINUE THROUGH THE OVERNIGHT PERIOD.
AS A COASTAL STORM CRAWLS SLOWLY NORTH INTO EARLY TOMORROW, A
TIGHTENING PRESSURE GRADIENT HAS RESULTED IN INCREASING N TO NE
FLOW. THIS HAS SET UP A PERIOD OF LOW-END LOW-LEVEL WIND SHEAR
FOR THE EASTERN AIRFIELDS (IPT, LNS, MDT) INTO EARLY TUESDAY
MORNING AS WINDS AT THE SURFACE REMAIN LIGHT DUE TO A STABLE
NOCTURNAL BOUNDARY LAYER. SLIGHTLY AFTER SUNRISE, DIURNAL
HEATING WILL ALLOW THE STABLE BOUNDARY LAYER TO GIVE WAY TO
DEEPER MIXING RESULTING IN WIND GUSTS IN THE 15-20 KT RANGE FOR
THE EASTERN AIRFIELDS.
WED-SAT...PATCHY AM FOG AND FROST POSSIBLE IN THE NORTH AND WEST;
OTHERWISE, VFR CONDITIONS WILL PREVAIL.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
WHAT HAS CHANGED...DANGELO
KEY MESSAGES...STEINBUGL/BAUCO
DISCUSSION...DANGELO/STEINBUGL/BAUCO
AVIATION...BEATY
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