<message to="mfannin2@nwws-oi.weather.gov/jaxl#adecc3c5e2157e6cf777ed1e32a81294" type="groupchat" from="nwws@conference.nwws-oi.weather.gov/nwws-oi"><body>KCTP issues Area Forecast Discussion (AFD) valid 2024-06-01T02:57:00Z</body><html xmlns="http://jabber.org/protocol/xhtml-im"><body xmlns="http://www.w3.org/1999/xhtml">KCTP issues Area Forecast Discussion (AFD) valid 2024-06-01T02:57:00Z</body></html><x xmlns="nwws-oi" id="nwws_processor.4715" issue="2024-06-01T02:57:00Z" ttaaii="FXUS61" cccc="KCTP" awipsid="AFDCTP"><![CDATA[

369

FXUS61 KCTP 010257

AFDCTP



Area Forecast Discussion

National Weather Service State College PA

1057 PM EDT Fri May 31 2024



.SYNOPSIS...

*Pleasant rain-free end to May and splendid start to June

*Chance of rain returns Sunday

*Trending warmer, more humid, and more unsettled next week



&&



.NEAR TERM /THROUGH SATURDAY/...

Ideal radiational cooling setup again tonight (with abnormally 

dry/low pwat air in place and sfc ridge axis overhead) supports

minimum temps at or below the 5-10th percentile NBM or closer 

to the tabular MAVMOS (which verified much better last night)

particularly in the northern tier. The end result is another

late season frost risk focused over the NW Mtns, where a frost 

advy was issued for 1-7AM Saturday. Air/water spreads exceeding

25 degrees should also support fog in the deep river/stream

valleys north of I-80 late tonight.



&&



.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

Upper level ridging over PA will ensure fair weather Saturday.

The surface high will slip off the East Coast, resulting in a

warmer southerly return flow, with 850mb temps supporting highs

ranging from the mid 70s over the N Mtns, to the low 80s in the

Susq Valley. Warm advection aloft should spread increasing

cirrus into the region Saturday. However, model RH profiles

suggest it will be relatively thin, so mostly sunny wording

should suffice. 



High clouds should continue to increase/thicken Saturday night 

ahead of shortwave trough and associated sfc low tracking 

eastward from the Ohio Valley. The bulk of latest model guidance

tracks a weak surface low just south of PA, likely resulting in

a period of rain Sunday PM. Cloud cover and an associated lack 

of instability in the models indicates thunderstorms are 

unlikely. Current NBM max temps are in the 70s Sunday. However, 

later shifts may have to dial back the temps depending on the 

arrival time of any rain. Latest 2m temp ensemble plumes are 

widely diverging, with most members cooler than the current 

forecast. Ensemble mean qpf suggests most likely rainfall Sunday

PM of <0.20 inches.



Passage of the shortwave should result in drier weather Monday.

However, the combination of a lingering frontal boundary south

of PA and high pressure to the north could result in persistent low

clouds, especially over Southern PA.



&&



.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

Medium range guidance points to fair and warm weather Tuesday,

with ridging at the surface and aloft over PA. Falling heights

and surging pwats ahead of a deepening upper level trough over

the Grt Lks will result in showery weather Wednesday and 

Thursday. At the surface, the latest GEFS and EC both indicate 

an occluded front will traverse Central PA Thu PM, as a triple 

point low passes south of the area. This scenario favors 

relatively stable air over the forecast area with a limited risk

of severe weather. Ensemble plumes suggest most likely areal 

average rainfall Wed-Thu between 0.5 and 1 inch. 



Latest GEFS and EPS indicate drier weather Friday, as the low

level jet/plume of highest pwats shift east of PA with the

exiting cold/occluded front. However, scattered, diurnally-

driven showers appear possible, especially over the NW Mtns,  

associated with the deep upper trough/closed low parked over 

the Grt Lks. 



&&



.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...

Light winds and mainly clear skies are prevailing across central

Pennsylvania airspace this evening. Tonight would make for a

good radiational cooling night, but with a lack of moisture fog

formation will be difficult. Patchy fog is possible in NW PA,

but confidence is low (<20%), thus a mention has not been made

in the 00Z TAF package for BFD. 



Winds will remain light tomorrow with VFR conditions continuing

across the area.  



Outlook...



Sat...Mainly clear skies with VFR conditions.



Sun...PM Sct showers and thunderstorms



Mon...Patchy AM fog, slight chance of PM t-storms. 



Tue-Wed...Showers and thunderstorms possible.



&&



.CLIMATE...

With only 1 day left, the preliminary monthly summary for May 

2024 would be notably warmer than the historical average 

(ranking in the top 5-25th warmest) with near to above normal 

precipitation. CLMs should be issued overnight on the midshift.



&&



.CTP WATCHES/WARNINGS/ADVISORIES...

Frost Advisory until 7 AM EDT Saturday for PAZ005-006-010-011.



&&



$$



SYNOPSIS...Steinbugl

NEAR TERM...Fitzgerald/Steinbugl

SHORT TERM...Fitzgerald/Steinbugl

LONG TERM...Fitzgerald

AVIATION...Bowen

CLIMATE...Steinbugl

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