075
FXUS61 KCTP 191057
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
557 AM EST TUE NOV 19 2024
SYNOPSIS
*MOSTLY CLOUDY AND RELATIVELY MILD INTO MIDWEEK WITH LIGHT RAIN
SPREADING WEST TO EAST LATE THIS AFTERNOON THROUGH TONIGHT
*GUSTY RAIN SHOWERS LATER WEDNESDAY WILL PRECEDE THE FIRST TASTE
OF WINTER WEDNESDAY NIGHT THROUGH FRIDAY
*THE FIRST SNOW ACCUMULATION OF THE SEASON IS EXPECTED IN THE
ALLEGHENY MOUNTAINS WITH SEVERAL INCHES POSSIBLE AT PEAK
ELEVATIONS IN THE LAUREL HIGHLANDS BY THE WEEKEND
NEAR TERM /THROUGH TONIGHT/
SOME PATCHY FOG AND LOW CLOUDS UNDER AN INCREASING SHIELD OF
MID AND HIGH CLOUDS EARLY THIS MORNING AS WAA RAMPS UP AHEAD OF
DEEP UPPER TROUGH CARVING OUT FROM THE NORTHERN PLAINS/UPPER
MIDWEST SOUTHWARD TOWARD THE OZARKS.
UPPER LEVEL RIDGING SHOULD PROVIDE CENTRAL PA WITH RELATIVELY
MILD AND RAIN-FREE CONDITIONS FOR MOST OF TODAY. WEAK MIXING
UNDER THE RIDGE AXIS ALONG WITH PLENTY OF CLOUDS WILL RESULT IN
LOWER TEMPS (-5 TO -10F) VS. YESTERDAY (MONDAY) IN MOST
LOCATIONS WITH FCST MAX TEMPS IN THE 50 TO 60F RANGE (+5-10F
ABOVE DAILY CLIMO).
THE AFOREMENTIONED WAA ALONG WITH SURGE OF 1" PWATS TIED TO
WEAKENING LLJ FOCUSED INTO THE UPPER OHIO VALLEY SHOULD SUPPORT
A PERIOD OF LIGHT RAIN SPREADING WEST TO EAST FROM LATE THIS
AFTERNOON THROUGH THE FIRST PART OF TONIGHT. AS THE DEEPER
MOISTURE PEELS AWAY, FCST SOUNDINGS INDICATE THE SECOND HALF OF
TONIGHT INTO EARLY WEDNESDAY MORNING WILL FEATURE LINGERING
LIGHT RAIN/DRIZZLE AND AREAS OF FOG GIVEN RESIDUAL BL MOISTURE
UNDER INVERSION AND VERY LIGHT SFC WINDS FROM THE SOUTH/EAST.
RAINFALL TOTALS WILL BE LARGELY NEGLIGIBLE AT <0.10" FOR MOST OF
CENTRAL PA (HIGHEST AMOUNTS OVER THE ALLEGHENY PLATEAU), BUT
ENOUGH TO MAKE MOST SURFACES WET. A VERY MILD NIGHT BY MID TO
LATE NOVEMBER STANDARDS) WITH FCST LOW TEMPS +15-20F ABOVE THE
HISTORICAL AVERAGE RANGING FROM THE LOWER 40S IN THE ENDLESS
MTNS TO AROUND 50F ON THE LAUREL RIDGETOPS.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/
FOCUS THEN SHIFTS TO A VIGOROUS BOWLING BALL CUT-OFF UPPER LOW
BARRELING EAST SOUTHEASTWARD THROUGH THE GREAT LAKES. MODEL
SOUNDINGS INDICATE AN EASTERLY FLOW OFF OF THE ATLANTIC WILL
LIKELY YIELD STRATUS OVER MUCH OF THE AREA WED, ESPECIALLY OVER
THE CENTRAL MTNS. FALLING HEIGHTS AND SURGING PWATS ALONG A
SOUTHERLY LOW LEVEL JET SHOULD THEN BRING THICKENING CLOUDS AND
AN INCREASING CHANCE OF SHOWERS ACROSS THE ENTIRE AREA BY LATE
WEDNESDAY OR WED EVENING. WE HAVE UNDERCUT NBM MAX TEMPS WED,
DUE ITS WARM BIAS IN EASTERLY FLOW/CAD SCENARIOS. REGARDLESS,
WEDNESDAY WILL BE THE LAST MILD DAY FOR A WHILE AS COOLER, MORE
SEASONABLE AIR ARRIVES BY THURSDAY.
RECENT GUIDANCE ALL TRACKS A SURFACE COLD/OCCLUDED FRONT THROUGH
CENTRAL PA WED EVENING IN ADVANCE OF THE UPPER LOW APPROACHING
FROM THE GRT LKS. STRONG LARGE SCALE FORCING AHEAD OF THE UPPER
LOW AND LOW LEVEL CONVERGENCE ALONG THE FRONT SUPPORTS A HIGH
CHANCE OF RAIN WED NIGHT. SHALLOW CONVECTION IS POSSIBLE NEAR OR
ALONG THE COLD FRONT GIVEN RAPIDLY COOLING TEMPERATURES ALOFT.
THE MOST LIKELY RAINFALL BY LATE WED NIGHT IS IN THE 0.25 TO
0.75 INCH RANGE, WITH THE HIGHEST TOTALS OVER THE EASTERN PART
OF THE FORECAST AREA.
GUIDANCE INDICATES A DRY SLOT WILL WORK INTO CENTRAL PA THURSDAY
MORNING, THEN A PERIOD OF CHILLY AND UNSETTLED WEATHER LOOKS
CERTAIN LATE THIS WEEK, AS THE UPPER LOW PIVOTS ACROSS SOUTHERN
PA AND PINWHEELS NEAR THE NJ COAST. A DEEP MOIST NORTHWEST FLOW
ON THE WESTERN PERIPHERY OF THE EXITING UPPER LOW SHOULD RESULT
IN A LONG DURATION, UPSLOPE/OROGRAPHIC AND LAKE ENHANCED
PRECIPITATION EVENT FOCUSED OVER THE ALLEGHENY MTNS AND
PARTICULARLY THE LAUREL HIGHLANDS THROUGH THE END OF THE WEEK.
MODEL THERMAL PROFILES CURRENTLY LOOK COLD ENOUGH TO SUPPORT THE
FIRST ACCUMULATING SNOW OF THE SEASON ACROSS THE HIGHER
ELEVATIONS OF THE ALLEGHENIES THURSDAY INTO FRIDAY, BUT
SNOWFLAKES COULD EXTEND SOUTHEAST OF THE ALLEGHENY FRONT INTO
THE CENTRAL RIDGE AND VALLEY REGION AT TIMES.
THE LAUREL HIGHLANDS ARE POISED TO PICK UP THE MOST SNOW DUE TO
ENHANCED OROGRAPHIC FORCING, FAVORABLY NW FLOW TRAJECTORY, AND
COLDER SURFACE TEMPS. THURSDAY NIGHT LOOKS LIKE THE BEST SHOT AT
SEEING ADVISORY CRITERIA TOTALS OVER SOMERSET COUNTY WITH WPC
PWPF SHOWING HIGH PROBS (>70%) FOR SNOWFALL POTENTIALLY
EXCEEDING 4" AT ELEVATIONS ABOVE 2500FT. WE MODIFIED THE HWO TO
HIGHLIGHT THIS AREA.
LONG TERM /FRIDAY THROUGH MONDAY/
IN ADDITION TO FREQUENT PRECIPITATION AND BELOW NORMAL DAYTIME
TEMPERATURES, GUSTY WEST-NORTHWEST WINDS ARE ALSO ANTICIPATED
FRIDAY AND SATURDAY, AS A TIGHT GRADIENT DEVELOPS WEST OF AN
INTENSIFYING SURFACE LOW OVER NEW ENGLAND. LATEST EPS PLUMES
INDICATE GUSTS OF AROUND 30MPH ARE LIKELY BOTH DAYS. PERSISTENT
CLOUD COVER AND COOLER TEMPERATURES ALOFT WILL KEEP HIGH
TEMPERATURES 5-10 DEGREES BELOW AVERAGE LATE THIS WEEK, WHILE
OVERNIGHT LOWS ARE CLOSE TO NORMAL.
LINGERING LAKE EFFECT OVER THE W MTNS SHOULD DWINDLE BY SUNDAY
AFTERNOON, AS INVERSION HEIGHTS FALL AND HIGH PRESSURE
APPROACHES FROM THE WEST. MILDER CONDITIONS LOOK LIKELY NEXT
MONDAY AHEAD OF AN APPROACHING COLD FRONT, WHICH COULD PRODUCE
LATE DAY RAIN SHOWERS.
AVIATION /10Z TUESDAY THROUGH SATURDAY/
410 AM UPDATE.
NOT MUCH CHANGE, FOG AT SEG EARLIER IS GONE. A BRIEF BIT
OF FOG AT AOO, BUT MID DECK IN THAT AREA NOW, SO FOG IS OUT
OF THAT AREA TOO.
EARLIER DISCUSSION BELOW.
06Z TAFS SENT.
WAS CONCERN FOR FOG EARLIER IN THE EVENING, AS FIRST NIGHT IN
A LONG TIME THAT THERE WAS DEW ON THE CAR AND GRASS AND A BIT
OF FOG WAS FORMING IN SOME SPOTS WHEN I WAS DRIVING AROUND TOWN
DURING THE MID EVENING HOURS.
HOWEVER, MID LEVEL CLOUDS HAVE BEEN MOVING BACK INTO THE AREA.
THUS WENT ALONG WITH THE EARLIER TAF PACKAGE, BUT WILL MONITOR,
SPOTS LIKE IPT COULD SEE FOG, IF MID LVL CLOUDS HOLD OFF. SEG
IS AN INDICATION OF THE POTENTIAL FOR FOG.
OTHERWISE TODAY WILL BE ANOTHER DRY AND MILD DAY.
SHOWERS MOVE INTO WESTERN AREAS LIKE BFD AND JST BY MID TO LATE
EVENING.
WIDESPREAD SHOWERS ON WEDNESDAY WITH LESS THAN GREAT CONDITIONS
FOR AVIATION. THEN THE ATTENTION TURNS TO SNOW SHOWERS, AS ONE
HEADS INTO THURSDAY.
OUTLOOK...
WED...RESTRICTIONS LIKELY, MAINLY NW. MORE WIDESPREAD
RESTRICTIONS WITH RAIN AND LLWS WED NIGHT.
THU-SAT...RESTRICTIONS LIKELY WITH RAIN AND SNOW SHOWERS,
MAINLY ACROSS THE MOUNTAINS. WINDY.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...STEINBUGL
NEAR TERM...FITZGERALD/STEINBUGL
SHORT TERM...FITZGERALD/STEINBUGL/BANGHOFF
LONG TERM...FITZGERALD/DANGELO
AVIATION...MARTIN
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