480
FXUS61 KCTP 162344
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
644 PM EST SAT NOV 16 2024
SYNOPSIS
WE'LL HAVE A DRY, BREEZY AND MILDER START TO THE WEEKEND WITH
PARTIAL CLEARING AND AN ELEVATED RISK FOR WILDFIRE SPREAD ACROSS
EAST CENTRAL PA. A WEAK AND LOW PRECIP COLD FRONT WILL SLIDE
ACROSS THE NORTH LATE SUNDAY NIGHT INTO MONDAY, FOLLOWED BY A
WARM FRONT BRINGING A FEW SHOWERS ACROSS WEST CENTRAL PA LATE
TUESDAY.
THE NEXT CHANCE FOR WIDESPREAD PRECIPITATION WILL COME IN THE
FORM OF WIDESPREAD RAIN SHOWERS WEDNESDAY NIGHT INTO THURSDAY,
THEN A LIKELY CHANGEOVER TO SNOW ACROSS THE HIGHER TERRAIN OF
NORTHERN AND WESTERN PA WITH A MIX OF RAIN AND WET SNOW SHOWERS
IN THE VALLEYS.
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/
A LOW STRATUS DECK CONTINUES TO BLANKET MUCH OF THE CENTRAL AND
NW MTNS THIS AFTERNOON, WITH MOISTURE TRAPPED BETWEEN 2000-5000
FT, BENEATH A SUBSIDENCE INVERSION. MODEL SOUNDINGS INDICATE
SOME OF THE CLOUD AREA ACROSS THE CENTRAL MOUNTAINS WILL
CONTINUE TO ERODE PRIOR TO SUNSET, BUT CLOUDS WILL HOLD STRONG
IN THE NW INTO THE OVERNIGHT HOURS, AND PERHAPS EXPAND EAST
AGAIN AFTER DARK.
A FAIRLY TIGHT GRADIENT BETWEEN UPSTREAM HIGH PRESSURE OVER THE
GRT LKS AND LOW PRESSURE OFF OF THE EAST COAST WILL RESULT IN
GUSTY NORTHWEST WINDS AS HIGH AS 30 MPH IN SOUTHEASTERN ZONES
INTO EARLY THIS EVENING. SEE FIRE WX SECTION FOR LATEST
THINKING CONCERNING FIRE WEATHER.
A NORTH-SOUTH ORIENTED SURFACE HIGH PRESSURE RIDGE IS PROGGED
TO PUSH INTO PA TONIGHT, RESULTING IN DIMINISHING WIND. LATEST
SREF AND NAMNEST BOTH INDICATE PATCHY FOG IS POSSIBLE,
ESPECIALLY ACROSS THE NORTH AND WEST, AS THE SUBSIDENCE
INVERSION STRENGTHENS AND THE LOW CLOUD DECK PUSHES CLOSER TO
THE GROUND.
SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/
FAIR WEATHER AND LIGHT WIND ARE EXPECTED ON SUNDAY UNDER THE
HIGH PRESSURE SYSTEM. HOWEVER, WARM ADVECTION ALOFT IN ADVANCE
OF A SHORTWAVE OVER THE GRT LKS IS LIKELY TO SPREAD A VEIL OF
CIRRUS OVER THE REGION, ESPECIALLY IN THE NORTH. PROGGED 850MB
TEMPS SURGE TO 20 DEGREES ABOVE CLIMO SUNDAY. HOWEVER, WEAK
MIXING UNDER THE SURFACE RIDGE WILL RESULT A MORE MODEST WARMUP
WITH HIGHS IN THE 50S TO AROUND 60F.
A NORTHERN STREAM SHORTWAVE WILL PIVOT ACROSS THE EASTERN GREAT
LAKES INTO NEW ENGLAND LATE SUNDAY NIGHT INTO EARLY MONDAY.
THIS FEATURE WILL SEND A WEAK COLD FRONT THROUGH THE REGION
AND TRIGGER SOME LIGHT RAIN SHOWERS DOWNWIND OF LAKE ERIE CLOSE
NEAR AND TO THE NORTH OF THE NY BORDER. RIDGING SFC AND ALOFT
RETURNS FOR THE REST OF MONDAY, BRINGING DRY CONDITIONS WITH
MILDER DAYTIME TEMPERATURES IN THE 55-65F RANGE (+10-15 DEGREES
ABOVE THE HISTORICAL AVERAGE).
UPPER LEVEL RIDGING OVER PA SHOULD PROVIDE THE REGION WITH MILD
AND MOSTLY RAIN-FREE CONDITIONS TUESDAY. HOWEVER, WARM ADVECTION
ASSOCIATED WITH A WEAKENING SHORTWAVE LIFTING INTO THE GRT LKS
MAY PRODUCE A FEW SHOWERS, MAINLY OVER THE NW MTNS. FOCUS THEN
SHIFTS TO A CUT-OFF UPPER LOW DROPPING INTO THE MIDWEST.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AN APPROACHING AREA OF LOW PRESSURE WILL BRING A COLD/OCCLUDED
FRONT ACROSS PENNSYLVANIA ON WEDNESDAY, MAINLY IN THE AFTERNOON
AND EVENING HOURS. THIS INCREASED LIFT AND MOISTURE WILL BRING
ABOUT AN INITIAL ROUND OF SHOWERS WITH AN EVENTUAL TRANSITION
INTO A RAIN/SNOW MIX THURSDAY MORNING WITH COLDER AIR FILLING IN
BEHIND THE FRONTAL PASSAGE WITH SNOW SHOWERS BECOMING THE MORE
DOMINANT PRECIPITATION TYPE. IT IS OF NOTE THAT CONSIDERABLE
SPREAD REMAINS WEDNESDAY NIGHT INTO THURSDAY WITH REGARDS TO
TEMPERATURES AND DEW POINTS BEHIND THIS FRONTAL PASSAGE, THUS
HAVE STUCK CLOSE TO NBM GUIDANCE GIVEN THIS UNCERTAINTY.
MODEL GUIDANCE DOES OUTLINE LESS SPREAD IN THE THURSDAY EVENING
THROUGH FRIDAY TIMEFRAME, AS THE UPPER LEVEL LOW IS PROGGED TO
PASS IN CLOSE PROXIMITY TO NORTHERN PENNSYLVANIA. ENHANCED
WESTERLY FLOW BEHIND THE UPPER LOW AND FRONTAL PASSAGE SUPPORTS
CONTINUED MENTIONS OF UPSLOPE SHOWERS ALONG THE ALLEGHENY FRONT
THURSDAY AND FRIDAY WITH LOWER POPS FURTHER SOUTHEAST. THERE
WILL REMAIN SOME CHANCES OF PRECIPITATION ACROSS SE PA ON
THURSDAY, WITH CHANCES OF PRECIPITATION DECREASING FRIDAY
EVENING AND INTO THE WEEKEND.
ACROSS WESTERN PENNSYLVANIA, THE AFOREMENTIONED COOLER
TEMPERATURES WILL PROMOTE A RAIN/SNOW MIX FOR LOCATIONS NORTH
AND WEST OF THE ALLEGHENY FRONT, WITH SNOW SHOWERS BECOMING THE
MORE DOMINANT PRECIPITATION TYPE IN THE HIGHER ELEVATIONS. AT
THIS TIME, ANY PROSPECT OF SNOW ACCUMULATION WILL BE CONFINED TO
THE HIGHEST ELEVATIONS OF NORTHWESTERN PENNSYLVANIA AND THE
LAUREL HIGHLANDS.
AVIATION /00Z SUNDAY THROUGH THURSDAY/
MVFR CEILINGS CONTINUE AT BFD AND UNV THIS EVENING, WHILE THE
REST OF CENTRAL PENNSYLVANIA IS CURRENTLY VFR. VFR CONDITIONS
ARE EXPECTED TO CONTINUE THROUGH THE NIGHT EAST OF UNV, WHILE
AREAS TO THE WEST WILL SEE CEILING AND VISIBILITY RESTRICTIONS
DEVELOP. MODEL SOUNDINGS SUGGEST THAT AS UPPER LEVEL RIDGING
BUILDS IN FROM THE WEST, LOW LEVEL MOISTURE WILL BECOME TRAPPED
BENEATH A SUBSIDENCE INVERSION. THIS WILL LEAD TO IFR/LIFR
CEILINGS AT BFD AND JST, AS WELL AS THE POTENTIAL FOR IFR/LIFR
VISIBILITIES. WHILE CONFIDENCE IN LOW CLOUDS AND FOG IS HIGHEST
AT BFD/JST (80-90%), IT IS POSSIBLE THAT FOG DEVELOPS FARTHER TO
THE EAST AS WELL (AOO/UNV/IPT). THERE IS A MUCH LOWER CHANCE OF
ANY FOG DEVELOPING AT MDT/LNS.
FOG AND LOW CLOUDS WILL GRADUALLY DISSIPATE DURING THE MORNING
AND WILL GIVE WAY TO VFR CONDITIONS AREA-WIDE BY THE AFTERNOON.
WINDS WILL BE LIGHT THROUGH THE 00Z TAF PERIOD, WITH WEST-
NORTHWEST WINDS AROUND 3-5 KNOTS.
OUTLOOK...
SUN NIGHT - EARLY MON...CFROPA. MVFR CIGS/VIS IN -SHRA, MAINLY N
HALF.
MON PM-TUES...NW FLOW. IFR/MVFR CIGS NW, VFR SE.
WED...RESTRICTIONS POSS, MAINLY NW. MORE WIDESPREAD RESTRICTIONS
WITH RAIN AND LLWS WED NIGHT.
THU...RESTRICTIONS LIKELY WITH RAIN AND SNOW SHOWERS.
FIRE WEATHER
THE FIRE WEATHER WATCH HAS BEEN CANCELLED AS CONFIDENCE HAS
INCREASED THAT RH VALUES WILL REMAIN ABOVE 30 PERCENT ACROSS THE
AREA PREVIOUSLY IN THE WATCH. ALTHOUGH CRITICAL FIRE WEATHER
CONDITIONS ARE NO LONGER EXPECTED, THERE IS STILL AN INCREASED
RISK OF WILDFIRE SPREAD AND A SPECIAL WEATHER STATEMENT HAS BEEN
ISSUED TO DISCUSS THIS RISK. FOR AREAS EAST OF THE SUSQUEHANNA
RIVER, MINIMUM RELATIVE HUMIDITY VALUES WILL RANGE FROM THE
UPPER 30S TO THE LOW 40S PERCENT ACCOMPANIED BY WIND GUSTS
BETWEEN 25 AND 35 MPH. THE LOWEST RH VALUES ARE EXPECTED IN
EASTERN SCHUYLKILL COUNTIES, WHERE THEY MAY BRIEFLY DROP TO
NEAR 30 PERCENT (35 PERCENT CHANCE). THE 1-HR AND 10-HR FUEL
MOISTURES ARE ALSO ABOVE CRITICAL LEVELS, EXPECTED TO REMAIN
ABOVE 10 PERCENT TODAY PER DCNR REPORTS.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...LAMBERT/COLBERT
NEAR TERM...LAMBERT/COLBERT
SHORT TERM...LAMBERT/COLBERT
LONG TERM...FITZGERALD/NPB
AVIATION...BAUCO
FIRE WEATHER...COLBERT
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page