310
FXUS61 KCTP 171755
AFDCTP
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1255 PM EST SUN NOV 17 2024
SYNOPSIS
* DRY STRETCH CONTINUES INTO TUESDAY FOR MOST OF THE AREA WITH
MILD TEMPERATURES AND LIGHT WINDS.
* A SHORTWAVE WILL BRING LIGHT SHOWERS TO NORTHERN PA LATE
TONIGHT AND THEN MORE RAIN IS POSSIBLE MAINLY IN WESTERN PA
TUESDAY AFTERNOON INTO WEDNESDAY.
* MORE WIDESPREAD PRECIPITATION AND MUCH COOLER TEMPERATURES
ARRIVE WEDNESDAY NIGHT INTO THURSDAY AS AN DEEP UPPER LOW
PASSES OVERHEAD AND BRINGS GUSTY WINDS AS WELL AS THE FIRST
ACCUMULATING SNOW OF THE SEASON FOR PARTS OF THE AREA.
NEAR TERM /THROUGH TONIGHT/
PATCHY VALLEY FOG AND SOME LOW CLOUDS HAVE MIXED OUT AT MIDDAY
WITH TEMPERATURES IN THE 40S AREAWIDE. MILDER AIR STREAMING
EAST AT MID AND UPPER LEVELS OF THE ATMOSPHERE CONTINUES TO ADVECT
AN EXTENSIVE SHIELD OF CIRRUS TODAY. THE CIRRUS WILL BE THICK
ENOUGH TO DIM OR EVEN BLOCK THE LOW ANGLE SUN AT TIMES TODAY.
WE'LL CALL IT A MIX OF SUN AND CLOUDS, THOUGH BREAKS IN THE
CIRRUS DECK WILL BE RELATIVELY INFREQUENT.
EXPECT MAX TEMPS TO VARY FROM THE UPPER 40S ACROSS THE HIGH
TERRAIN OF THE NORTH AND WEST TO THE LOW AND MID 50S ACROSS MUCH
OF THE REMAINDER OF CENTRAL PA. SOME UPPER 50S ARE STILL
POSSIBLE ACROSS THE FAR SE ZONES WHERE THE LONGEST DURATION OF
SUNSHINE WILL OCCUR BEFORE THE HIGH CLOUDS BEGIN TO THICKEN UP.
A RATHER EXTENSIVE AND THICK SHIELD OF MID AND HIGH CLOUDS
TONIGHT WILL LEAD TO MIN TEMPS IN THE UPPER 30S (EAST) TO MID
40S (SW MTNS) WHICH WILL BE A HEALTHY 8-15 DEG F ABOVE NORMAL. A
NORTHERN STREAM SHORTWAVE WILL PIVOT ACROSS THE EASTERN GREAT
LAKES INTO THE NEW ENGLAND STATE FOR LATE TONIGHT INTO EARLY
MONDAY. THIS FEATURE WILL SEND A WEAK COLD FRONT THROUGH THE
REGION AND TRIGGER SOME LIGHT RAIN SHOWERS DOWNWIND OF LAKE ERIE
NEAR AND TO THE NORTH OF THE NY BORDER.
SHORT TERM /MONDAY THROUGH WEDNESDAY/
RIDGING SFC AND ALOFT RETURNS ON MONDAY, BRINGING DRY
CONDITIONS WITH MILDER DAYTIME TEMPERATURES IN THE 55-65F RANGE
(+10-15 DEGREES ABOVE THE HISTORICAL AVERAGE). MORNING CLOUDS
ASSOCIATED WITH THE AFOREMENTIONED FRONT WILL CLEAR OUT AS THE
DAY GOES ON, GIVING WAY TO A MOSTLY SUNNY MIDDAY TO AFTERNOON.
HIGH CLOUDS WILL BEGIN STREAMING IN BY SUNSET AHEAD OF THE NEXT
WEATHER MAKER.
UPPER LEVEL RIDGING OVER PA SHOULD PROVIDE AT LEAST THE CENTRAL
AND EASTERN ZONES WITH MILD AND MOSTLY RAIN-FREE CONDITIONS FOR
THE BULK OF TUESDAY. HOWEVER, WARM ADVECTION ASSOCIATED WITH A
WEAKENING SHORTWAVE LIFTING INTO THE GRT LKS MAY LEAD TO
INCREASING LATE AFTERNOON/EVENING CLOUDS AND PERHAPS A FEW
SHOWERS, MAINLY OVER THE NW MTNS. FOCUS THEN SHIFTS TO A CUT-
OFF UPPER LOW DROPPING INTO THE MIDWEST.
ON WEDNESDAY, BETTER MOISTURE MOVES INTO THE REGION AND SHOULD
SUPPORT MORE CLOUDS AS WELL AS AN INCREASING CHANCE FOR SHOWERS
INTO THE EVENING. HIGHS ON WEDNESDAY WILL BE IN THE 50S AND
60S.
LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/
BY WEDNESDAY NIGHT, A SURFACE COLD FRONT AND AN ASSOCIATED
DEEPENING UPPER LOW WILL MOVE INTO PENNSYLVANIA, USHERING IN
WIDESPREAD RAIN SHOWERS OVERNIGHT WEDNESDAY INTO THURSDAY ALONG
WITH COOLER TEMPERATURES.
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT ABOUT THE
PERSISTENCE OF THIS PATTERN AND KEEPS SUB 0C 850MB TEMPS
OVERHEAD (OR NOT TOO FAR AWAY) THROUGH THE WEEKEND. THIS COLD
AIR ALOFT WILL COMBINE WITH WELL ABOVE NORMAL WATER TEMPERATURES
ON THE GREAT LAKES TO PRODUCE A PROLONGED PERIOD OF LAKE
ENHANCED AND UPSLOPE SHOWERS THURSDAY THROUGH AT LEAST SATURDAY.
THE COOLER TEMPERATURES AT THE SURFACE AND ALOFT WILL SUPPORT
RAIN CHANGING OVER TO SNOW AT TIMES THROUGH THE WEEKEND. THE
BEST CHANCE FOR ACCUMULATING SNOWFALL WILL BE IN THE TYPICAL
UPSLOPE/LAKE EFFECT REGIONS OF THE LAUREL HIGHLANDS AND
NORTHWEST MOUNTAINS, BUT SNOWFLAKES COULD EXTEND SOUTHEAST OF
THE ALLEGHENY FRONT AT TIMES.
IN ADDITION TO FREQUENT PRECIPITATION AND COLD TEMPERATURES,
GUSTY WEST- NORTHWEST WINDS ARE ALSO ANTICIPATED FOR SEVERAL
DAYS INTO NEXT WEEKEND. AS THE SURFACE LOW DEEPENS AND LIFTS
NORTHEASTWARD, WRAP AROUND NORTHWESTERLY FLOW WILL BUFFET
CENTRAL PA WITH GUSTS PERHAPS ABOVE 30MPH. PERSISTENT CLOUD
COVER AND COOLER TEMPERATURES ALOFT WILL KEEP HIGH TEMPERATURES
IN THE UPPER 30S TO NEAR 50, WHICH IS MUCH COOLER THAN WE'RE
USED TO, BUT STILL ONLY A FEW DEGREES BELOW NORMAL FOR THIS TIME
OF YEAR.
AVIATION /18Z SUNDAY THROUGH FRIDAY/
THERE IS VERY HIGH (90-100%) CONFIDENCE IN VFR CONDITIONS
CONTINUING THROUGH 05Z MONDAY AS HIGH CLOUDS PERSIST ACROSS ALL
OF CENTRAL PENNSYLVANIA. AFTER 05Z MONDAY, THERE REMAINS SOME
SIGNAL IN THE BULK OF MODEL GUIDANCE FOR A DECK OF LOW-LEVEL
CLOUDS TO FORM ACROSS WESTERN PENNSYLVANIA, WITH ANY PROSPECT OF
RESTRICTIONS CONFINED TO THE 05-17Z MONDAY TIMEFRAME ACROSS
BFD/JST/AOO/UNV. INITIAL MVFR RESTRICTIONS ARE PROGGED BY A
COMBINATION OF GLAMP/RAP GUIDANCE TOWARDS THE 07-08Z TIMEFRAME
AT BFD, ALTHOUGH THERE REMAINS A POSSIBILITY (~30-40%) IN THE
LOW-LEVEL CLOUD DECK PUSHING TOWARDS THE AIRFIELD IN THE 05-07Z
TIMEFRAME WITH LOWER CONFIDENCE. THERE WILL ALSO REMAIN A PERIOD
WHERE CEILINGS COULD (~30-40% PROBABILITY) DIP BETWEEN 700 AND
1000FT AGL OUTLINED IN BEST IN THE 00Z/12Z HREF AT BFD; HOWEVER,
LOWER CONFIDENCE (~20%) IN THIS SOLUTION AS OF 18Z SUNDAY
WARRANTS A MENTION IN THE AFD ALONG WITH OUTLINING A SCATTERED
LOW-LEVEL DECK THIS FAR OUT.
AT OTHER WESTERN AIRFIELDS (JST/AOO/UNV), MODEL GUIDANCE DOES
SHOW FAIRLY GOOD AGREEMENT WITH RESPECT TO CEILINGS LOWERING
TOWARDS MVFR THRESHOLDS AT JST, WITH LESS SIGNALS IN MVFR
CEILINGS PREVAILING AT AOO/UNV. AFTER SUNRISE ON MONDAY,
GENERALLY EXPECT SCATTERING OUT OF THE LOWER-LEVEL CLOUD DECK
QUICKLY ACROSS EASTERN PENNSYLVANIA. SOME RESIDUAL LOW-LEVEL
CLOUDS WILL REMAIN AT JST/BFD, WITH THE BULK OF MODEL GUIDANCE
GENERALLY HOLDING ONTO LOW CEILINGS UNTIL THE 16-17Z MONDAY
TIMEFRAME.
RECENT MODEL GUIDANCE HAS ALSO BACKED OFF ON LLWS PARAMETERS AT
AOO/UNV/MDT/LNS AS WINDS INCREASE AT 925MB IN THE 06-10Z MONDAY
TIMEFRAME, THUS HAVE KEPT MENTIONS OF LLWS OUT OF THE 18Z
FORECAST PACKAGE. IT IS OF NOTE THAT MODEL GUIDANCE HAS TRENDED
SLIGHTLY MORE FAVORABLE AT UNV/LNS WHILE TRENDING LESS FAVORABLE
AT AOO/MDT, WHICH IS ANOTHER REASON FOR LOWER (~20%) CONFIDENCE
IN ANY LLWS MENTIONS THIS FORECAST CYCLE.
OUTLOOK...
TUE...MAINLY DRY WITH VFR CONDITIONS.
WED...RESTRICTIONS POSS, MAINLY NW. MORE WIDESPREAD
RESTRICTIONS WITH RAIN AND LLWS WED NIGHT.
THU-FRI...RESTRICTIONS LIKELY WITH RAIN AND SNOW SHOWERS.
CTP WATCHES/WARNINGS/ADVISORIES
NONE.
SYNOPSIS...BANGHOFF
NEAR TERM...LAMBERT/BANGHOFF
SHORT TERM...LAMBERT/BANGHOFF
LONG TERM...BANGHOFF/NPB
AVIATION...NPB
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