636
FXUS61 KCTP 161102
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
602 AM EST SAT NOV 16 2024
SYNOPSIS
WE'LL HAVE A DRY, BREEZY AND NOTABLY MILDER START TO THE
WEEKEND WITH PARTIAL CLEARING AND AN ELEVATED RISK FOR
WILDFIRE ACROSS EAST CENTRAL PA. A WEAK AND GENERALLY DRY
COLD FRONTAL PASSAGE WILL OCCUR EARLY ON MONDAY BEFORE A
REBOUND IN TEMPERATURES OCCURS ON 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 PM THIS EVENING/
RELATIVELY SHALLOW, BUT EXTENSIVE STRATUS AND STRATOCU CLOUDS
CONDITIONS TO BLANKET MUCH OF CENTRAL AND WESTERN PA EARLY THIS
SATURDAY MORNING WHILE PARTLY CLOUDY SKIES WERE NOTED OVER FAR
SOUTHEASTERN PA INVOF KMUI AND KLNS.
THE LOW CLOUD DECK COVERING MUCH OF THE CENTRAL MTNS AND
MIDDLE/WEST BRANCH PORTION OF THE SUSQ VALLEY EARLY THIS
MORNING SHOULD ERODE FROM THE SOUTH AND EAST DURING THE MIDDAY
AND AFTERNOON - PER THE LATEST HREF AND NBM DATA - AS THE
BOUNDARY LAYER NEARLY TRIPLES FROM AROUND 1000 FT AGL TO 3000
FEET AGL THIS AFTERNOON.
UPSLOPE, NORTHWEST FLOW AND MOISTURE OFF THE GLAKES WILL
RESULT IN THE MOST PERSISTENT CLOUD COVER OVER THE W MTNS.
MODEL SOUNDINGS INDICATE THE NW MTNS WILL BE THE LAST TO CLEAR,
WITH BREAKING CLOUDS NOT ANTICIPATED THERE UNTIL AROUND DUSK.
DAYBREAK TEMPS TODAY WILL RANGE FROM AROUND 40F OVER THE NW
MTNS, TO THE MID AND UPPER 40S ACROSS THE LOWER SUSQ VALLEY.
THIS AFTERNOON'S HIGH TEMPS WILL RANGE FROM THE UPPER 40S ACROSS
THE NORTHERN AND WESTERN MOUNTAINS OF THE STATE TO THE UPPER 50S
THROUGH MUCH OF THE MIDDLE AND LOWER SUSQ VALLEY.
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 SATURDAY. BUKFIT SOUNDINGS SUPPORT
FREQUENT GUSTS IN THE 20-25KT RANGE FROM LATE MORNING THROUGH
LATE AFTERNOON, WITH THE STRONGEST GUSTS ACROSS THE EASTERN PART
OF THE FORECAST AREA. SEE FIRE WX SECTION FOR LATEST THINKING
CONCERNING FWW/RFW/SPS.
SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/
A NORTH-SOUTH ORIENTED SURFACE HIGH PRESSURE RIDGE IS PROGGED
TO PUSH INTO PA TONIGHT, RESULTING IN DIMINISHING WIND AND
SKIES BECOMING MOSTLY CLEAR.
LATEST SREF AND NAMNEST BOTH INDICATE VALLEY FOG IS A GOOD BET
LATER TONIGHT, ESPECIALLY OVER THE ALLEGHENIES, WHERE THE WINDS
SHOULD DIMINISH EARLIEST.
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).
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
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.
A COLD/OCCLUDED FRONT IS PROGGED TO SWEEP ACROSS PA AHEAD OF
THIS FEATURE WED PM, ACCOMPANIED BY A ROUND OF SHOWERS. MEAN QPF
BASED ON THE 18Z EPS IS AROUND A HALF INCH WED/WED NIGHT.
HOWEVER, THERE IS A WIDE SPREAD IN THE GUIDANCE. A DECENT NUMBER
OF ENSEMBLE MEMBERS ARE MUCH WETTER (1-2 INCHES), REPRESENTING
THE CHANCE THAT MOISTURE FROM SARA'S REMNANTS ARE DRAWN NORTH
INTO PA AHEAD OF THE FRONT.
ALL MEDIUM RANGE GUIDANCE SUPPORTS UNSETTLED AND CHILLY WEATHER
THURSDAY AND FRIDAY, AS THE UPPER LOW EITHER PASSES OVER OR JUST
NORTH OF PA. A MOIST NORTHWEST FLOW ON THE WESTERN PERIPHERY OF
THE UPPER LOW, COMBINED WITH LAKE EFFECT MOISTURE, SUPPORTS A
PERIOD OF UPSLOPE PRECIPITATION ACROSS THE ALLEGHENY PLATEAU
THU PM THROUGH FRIDAY. THERMAL PROFILES LOOK COLD ENOUGH DURING
THIS TIMEFRAME FOR A RAIN/SNOW MIX OVER THE ALLEGHENY PLATEAU,
WITH THE POTENTIAL OF SOME ACCUMULATION, ESPECIALLY ON THE
RIDGETOPS. A NORTHWEST FLOW SHOULD YIELD LIGHTER, MORE
INTERMITTENT RAIN SHOWERS IN THE LOWER ELEVATIONS EAST OF THE
ALLEGHENIES.
AVIATION /12Z SATURDAY THROUGH WEDNESDAY/
FOR THE 12Z TAF PACKAGE, MAY END UP HOLDING ONTO THE CLOUDS
A BIT LONGER, CONCERN IS WARMING ALOFT MAY TRAP THE MOISTURE
UNDER THE THE INVERSION.
EARLIER DISCUSSION BELOW.
A COMPLEX AREA OF LOW PRESSURE ALONG THE EAST COAST WILL KEEP
WIDESPREAD LOW CLOUDS AND EVEN ISOLATED POCKETS OF DRIZZLE OVER
THE MOUNTAINS TO LATER THIS MORNING OR EARLY THIS AFTERNOON.
AS THE SUN COMES UP AND THE CLOUDS START TO BREAK UP, WINDS
WILL BECOME MORE ON THE GUSTY SIDE. WINDS WILL WEAKEN TOWARD
SUNSET.
OUTLOOK...
SUN...VFR CONDITIONS.
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.
FIRE WEATHER
AN ELEVATED RISK OF WILDFIRE SPREAD IS EXPECTED LATE THIS
MORNING THROUGH THIS AFTERNOON, PRIMARILY ACROSS THE
COUNTIES TO THE EAST OF THE LOWER AND MIDDLE SUSQ MAINSTEM.
THIS THREAT FOR WILDFIRE SPREAD WILL BE DUE TO A COMBINATION OF
GUSTY WINDS 25-35 MPH FROM THE NORTHWEST, LOW RELATIVE HUMIDITY
(<40%) AND DRY FUELS AND LEAF LITTER. THE LACK OF CURING ON
FRIDAY, COMBINED WITH AN UPTICK IN MINRH HAS LEAD US TO HOLD
OFF ON UPGRADING TO RFW OR EXPANDING THE FWW. COORDINATION
CONSENSUS WITH FIRE PARTNERS SUPPORTS RIDING THE WATCH THROUGH
SATURDAY (IN LIEU OF CANCELING AND ISSUING SPS).
CTP WATCHES/WARNINGS/ADVISORIES
FIRE WEATHER WATCH FROM 9 AM EST THIS MORNING THROUGH THIS
AFTERNOON FOR PAZ051>053-057>059-066.
SYNOPSIS...LAMBERT/STEINBUGL
NEAR TERM...LAMBERT/FITZGERALD
SHORT TERM...LAMBERT/FITZGERALD/STEINBUGL
LONG TERM...FITZGERALD
AVIATION...MARTIN
FIRE WEATHER...LAMBERT/STEINBUGL
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page