208
FXUS61 KCTP 150947
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
447 AM EST FRI NOV 15 2024
SYNOPSIS
LIGHT RAIN SHOWERS FOCUSED ACROSS THE CENTRAL MOUNTAINS AND
SUSQUEHANNA VALLEY EARLY TODAY WILL DECREASE IN COVERAGE
DURING THE MID TO LATE MORNING HOURS AS UPPER LEVEL LOW
PRESSURE CONTINUES TO DRIFT SOUTHEAST ACROSS VIRGINIA AND TOWARD
THE DELMARVA PENINSULA.
DRY AND MILDER WEATHER IS ANTICIPATED FOR THE WEEKEND, WITH
BREEZIER CONDITIONS LEADING TO AN ELEVATED WILDFIRE SPREAD RISK
ON SATURDAY. A PASSING RAIN SHOWER WILL BE POSSIBLE ON MONDAY;
OTHERWISE CONTINUED SEASONABLY MILD AND DRY THROUGH EARLY NEXT
WEEK
NEAR TERM /UNTIL 6 PM THIS EVENING/
1012 MB, SLOWLY WEAKENING SURFACE LOW OVER THE NORTH SHORE OF
LAKE ERIE EARLY THIS MORNING HAS A SFC TROUGH EXTENDING SSE
THROUGH THE UPPER OHIO RIVER VALLEY AND CENTRAL APPALACHIANS TO
A SECONDARY LOW (~1002 MB) JUST SOUTH OF THE OUTER BANKS.
UPPER LEVEL LOW PRESSURE SINKING SE FROM NORTHERN VA THIS
MORNING WILL INJECT ENERGY INTO THIS LOW CAUSING QUITE RAPID
INTENSIFICATION, BUT LITTLE IMPACT TO OUR CWA.
RIDGING ALOFT FROM THE WEST AND LLVL RIDGING FROM THE NORTH WILL
COMBINE TO FIRST DECREASE THE MID AND UPPER LEVEL CLOUD DECK
THEN GRADUALLY ERODE THE LOWER STRATUS/STRATOCU DECK FROM NE TO
SW ACROSS THE REGION LATE THIS MORNING THROUGH THIS AFTERNOON.
BUFKIT SOUNDINGS WITH HIGH MOISTURE UP THROUGH ABOUT 5 KFT AGL
ARE MORE PESSIMISTIC THAN THE HREF/NBM APPROACH WITH RESPECT TO
THE TIMING OF THE CLEARING TREND AND DELAY IT BY UP TO 2-3 HOURS
AT ANY ONE LOCATION THIS AFTERNOON.
THE CLOSE PROXIMITY TO THE AFOREMENTIONED SFC TROUGH WILL KEEP
THE LOW CLOUDS LINGERING THE LONGEST ACROSS THE WESTERN MTNS OF
PA WITH EVEN SOME DRIZZLE POSSIBLE INTO EARLY THIS AFTERNOON.
TEMPS TO START THE DAY WILL RANGE FROM THE UPPER 30S TO
LOW 40S. HIGHS THIS AFTERNOON WILL BE IN A RATHER TIGHT RANGE OF
ONLY 5-7 DEG F - IN THE UPPER 40S (NORTHERN AND WESTERN MTNS)
TO LOW AND MID 50S THROUGHOUT THE CENTRAL AND SOUTHERN VALLEYS.
SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/
LOW CLOUDS WILL LIKELY LINGER OVER THE WESTERN ALLEGHENIES AND
LAUREL HIGHLANDS TONIGHT WITH DECREASING CLOUD COVER (SCT-BKN)
FURTHER EAST.
HIGH PRESSURE BUILDING IN FROM THE GRT LKS SHOULD SUPPLY FAIR
WEATHER SATURDAY. HOWEVER, MODEL SOUNDINGS INDICATE LOW LEVEL
MOISTURE TRAPPED BENEATH A SUBSIDENCE INVERSION COULD RESULT IN
STUBBORN LOW CLOUDS THE FIRST HALF OF THE DAY WHERE THE
NORTHWEST FLOW ASCENDS THE ALLEGHENY PLATEAU.
VERTICAL MIXING UP TO BETWEEN 2.5-3 KFT AGL SATURDAY WITH
PROGGED 900MB TEMPS OF 4-6C YIELDS HIGH TEMPS RANGING FROM
AROUND 50F OVER THE HIGHEST ELEVATIONS OF THE N MTNS/LAURELS, TO
AROUND 60F IN THE SUSQ VALLEY.
A MODERATELY TIGHT LLVL PRESSURE GRADIENT ACCENTUATED BY LARGER
SCALE DESCENT WITHIN THE THERMALLY INDIRECT/RIGHT EXIT REGION
OF AN 80KT NW JET MAX WILL LEAD TO PEAK NW WIND GUSTS IN THE 25
TO 30 MPH RANGE ON SATURDAY.
POTENTIAL FOR ELEVATED TO CRITICAL FIRE WX CONDITIONS WILL
BE THE RESULT AND A FIRE WEATHER WATCH REMAINS IN EFFECT FOR THE
EASTERN THIRD OF THE CWA ON SATURDAY - WHICH MATCHES UP WELL
WITH PA DCNR/BOF CATEGORICAL VERY HIGH FIRE DANGER RISK.
LOOK FOR A FROSTY START TO SUNDAY WITH LOWS IN THE 25-35F
RANGE. HIGH PRESSURE DOME MIGRATES OVER CENTRAL PA ON SUNDAY
PROVIDING A MOSTLY SUNNY AND PLEASANT END TO THE WEEKEND WITH
LIGHT WINDS. HIGHS IN THE MID 50S TO LOW 60S REMAIN ABOVE
AVERAGE FOR MID NOVEMBER.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
A SUBTLE SHORTWAVE IS STILL PROGGED TO PASS NORTH OF US SUNDAY
NIGHT INTO MONDAY MORNING. A WEAK AND MOISTURE STARVED
COLD FRONT WILL SLIDE ACROSS THE STATE AS A RESULT, BUT GIVEN
HOW DRY THE AIRMASS WILL BE POPS HAVE BEEN CAPPED NEAR 30% AND
ARE ONLY PRESENT ACROSS THE NW WHERE MOISTURE WILL BE SUFFICIENT
FOR LIGHT PRECIPITATION.
SURFACE HIGH PRESSURE WILL BUILD IN ALONG WITH UPPER LEVEL
RIDGING PROVIDING FAIR AND TRANQUIL WEATHER FOR MONDAY AFTERNOON
BEFORE CLOUDS BEGIN BUILDING IN AGAIN FOR TUESDAY AHEAD OF A
DIGGING UPPER LEVEL TROUGH. HIGH TEMPERATURES FOR THE MIDDLE OF
NEXT WEEK WILL MODERATE AND BECOME 10-15 DEGREES ABOVE NORMAL
GIVEN RELATIVELY WARM 850MB TEMPS ALOFT. ADDITIONALLY A SLIGHT
CHANCE OF RAIN WILL PERSIST FOR TUE AND WED GIVEN THE
UNCERTAINTY OF THE SURFACE LOWS POSITION OFF TO OUR WEST.
WEDNESDAY AND BEYOND COULD BE THE FIRST SIGNAL FOR A PATTERN
CHANGE ACROSS THE REGION TO BECOME MORE COLD AND SEASONABLE.
STRONG HIGH PRESSURE WILL BUILD ACROSS THE WESTERN UNITED STATES
WITH A DEEP CLOSED LOW OVER THE HIGH PLAINS THAT WILL LIKELY
PROGRESS NORTH EASTWARD INTO THE END OF NEXT WEEK. CURRENT
GUIDANCE HAS A DEEP SURFACE LOW SPINNING OVER THE WESTERN GREAT
LAKES AT THE END OF NEXT WEEK WHICH COULD BRING IN OUR FIRST
WAVE OF CONTINENTAL POLAR AIR FOR THE SEASON.
AVIATION /09Z FRIDAY THROUGH TUESDAY/
CONFIDENCE REMAINS HIGH (80%) IN IFR CONDITIONS FOR THE REST OF THE
DAY AT JST AND BFD. THE EASTERN TERMINALS (IPT/MDT/LNS) WILL
STAY OUT OF IFR, WITH ONLY IPT AMONG THAT BUNCH DEALING WITH AN
MVFR CLOUD DECK. DZ IS POSSIBLE UNTIL MID-MORNING AT
JST/AOO/UNV. IMPROVEMENT IS THEN EXPECTED TO MVFR BY LATE
MORNING IN AOO AND UNV, BUT PERHAPS NOT VFR BEFORE THE END OF
THE DAY. CROSS-LAKE FLOW THEN REINFORCES THE LLVL MSTR AND COULD
EVEN TAKE IPT BACK TO MVFR FOR FRI NIGHT AND SAT, AND CERTAINLY
SINK AOO AND UNV BACK TO MVFR EVEN IF THEY IMPROVE.
THE NW WIND ABOVE THE SUBSIDENCE INVERSION INCREASES AGAIN FRI
EVENING AND LASTS INTO MID-DAY SAT, AND WARRANTS A MENTION OF LLWS
FOR THE LATTER PART THIS (06Z) PACKAGE, AND LIKELY LONGER FOR THE
NEW/12Z PACKAGE. THE SIGNAL IS STRONGEST OVER THE SRN, ESP 2 SERN
TERMINALS, WHERE A TIGHT GRADIENT DEVELOPS BETWEEN THE DEPARTING,
THEN OFF-SHORE, LOW AND THE HIGH MOVING IN FROM THE WEST. SAT AFTN
SFC GUSTS INTO THE M20S AT MDT AND LNS. MVFR CIGS STAY IN FOR THE NW
UNTIL SAT AM, THEN IMPROVE TO VFR (EVERYWHERE) AS HIGH PRESSURE
FLOATS OVERHEAD.
OUTLOOK...
SUN...IFR BFD/JST EARLY. IMPROVEMENT TO VFR FOR ALL TERMINALS
THROUGH THE DAY.
SUN PM-MON AM...CFROPA. MVFR CIGS/VIS IN -SHRA, MAINLY N HALF.
MON PM-TUES...NW FLOW. IFR/MVFR CIGS NW, VFR SE.
FIRE WEATHER
A FAIRLY TIGHT PRESSURE GRADIENT BETWEEN THE UPSTREAM HIGH AND
LOW PRESSURE OVER THE CANADIAN MARITIMES SHOULD RESULT IN WIND
GUSTS SAT AFTERNOON IN THE 20-30 MPH RANGE OVER THE EASTERN
PART OF THE FORECAST AREA PER LATEST BUFKIT SOUNDINGS. THE
WINDS, COMBINED WITH RH VALUES DIPPING TO NEAR 30PCT AND VERY
DRY FINE FUELS, WILL LIKELY RESULT IN AN ELEVATED RISK OF
WILDFIRE SPREAD.
CTP WATCHES/WARNINGS/ADVISORIES
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
AFTERNOON FOR PAZ051>053-057>059-066.
SYNOPSIS...LAMBERT/BAUCO
NEAR TERM...LAMBERT/BAUCO
SHORT TERM...LAMBERT/BAUCO
LONG TERM...BOWEN
AVIATION...DANGELO/BOWEN
FIRE WEATHER...FITZGERALD/STEINBUGL
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