FXUS61 KCTP 261747

AFDCTP



Area Forecast Discussion

National Weather Service State College PA

147 PM EDT Thu Jun 26 2025



.SYNOPSIS...

* Flash flood and severe t-storm risk increased this afternoon

  and evening over east central PA  

* Breaking heat gives way to drenching downpours into the last

  weekend of June; unsettled pattern continues to start July



&&



.NEAR TERM /THROUGH TONIGHT/...

Several changes/updates in the near term: 



1. [Flash] flood watch over east central PA: 3pm to midnight

Signals from the 00 and 12Z HREF continue to favor slow moving

storms along lee-side trough and backdoor frontal zone. Both

HREF and RRFS show pockets of elevated probabilities of >2"/hr 

rainfall rates by mid-late afternoon into the evening. Despite

the lack of synoptic/kinematic support, the favorable 

thermodynamic profile (1.75-2.00" PWs and max CAPEs 2000-3000 

J/Kg) combined with the likelihood of slow cell motions with the

potential for repetitive convection along the aforementioned 

boundaries are key drivers of the watch with point rain amounts

2-4" possible over a short duration. No change to the D1 SLGT

risk ERO from WPC. 



2. SPC convective outlook upgrade from risk level 1 to 2 (SLGT)

Full sunshine this morning across south central into southeast 

PA allowing temps to rise into the mid 80s to low 90s. While not

as extreme, hot/humid conditions will lead to scattered

thunderstorm development through the evening. Winds aloft are 

weak, suggesting disorganized/pulse convective modes. However, 

steep low-level lapse rates and moderate CAPE values will once 

again result in a risk of locally damaging wind gusts. 



Heat Advisory remains in effect until 7 PM EDT.



Showers will gradually fade into late tonight. There appears to

be an emerging signal for fog and low clouds overnight into 

early Friday morning particularly across the eastern half of 

the CWA with plenty of residual moisture and low level easterly 

flow.



&&



.SHORT TERM /FRIDAY/...

Friday should be a bit cooler across central and eastern PA, 

although another round or two of SHRA/TSRA is expected for the 

aftn/eve.



&&



.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...

The anomalous upper-level ridge that brought heat to much of 

the eastern United States will continue to gradually be 

suppressed to the south in the extended period, and long range 

models suggest that it should be replaced by an upper level 

trough over the northeastern United States by the middle of next

week.



As for sensible weather...the unsettled pattern will persist 

into at least the first half of the upcoming weekend, with 

SHRA/TSRA likely on Saturday, especially in the afternoon and

evening. Sunday looks like the better day of the weekend, with 

a small area of high pressure building in, and keeping PoPs less

than 40 percent. An approaching cold front and upper trough 

will bring more widespread SHRA/TSRA later Monday into Tuesday.

After that, we could be in for a welcome shot of cooler and 

drier weather for the middle to later part of next week.



&&



.AVIATION /18Z THURSDAY THROUGH TUESDAY/...

Main thing this morning is pockets of dense fog, especially

here at the office. Areas that did not get much rain have

less low clouds and fog. Expect conditions to improve by

13Z, given the strong June sun.



More information below.



Main change to the 06Z TAF package was to use VCSH more, 

instead of thunder. Cold front near PA early today, but main 

driving force will be lee side trough forming later this 

afternoon, as low levels heat up east of the mtns. Anyway, 

expect coverage to be less than yesterday.



Earlier discussion below.



Weak boundary dropping down from the north now will drape 

itself over the state tonight and be stubborn to move out over 

the next few days.



Overnight, fog is expected to develop across much of the region

in the wake of showers and storms today, mainly where it ended

up raining. The coverage will not be 100% of the area, and more

so in the valleys. Have kept MVFR and IFR visibility at most 

sites for a few hrs late tonight. That should dissipate Thurs AM

after just an hour or two of sun. There could be a deck of

low/IFR clouds instead or in addition to any fog over the NW. 



The high moisture lingers for the next few days, and little

change is expected to our pattern. Daily SHRA/TSRA, and any

could make some heavy rain or gusty winds. 



Outlook...



Fri-Mon...Continued impacts from SHRA/TSRA, mainly in the aftns

and eves. Less hot.



&&



.CLIMATE...

Record for MDT today is 100 set in 1952, not expecting to 

break that one.



&&



.CTP WATCHES/WARNINGS/ADVISORIES...

Flood Watch until midnight EDT tonight for PAZ028-037-041-042-

046-049>053-056>059-063>066.

Heat Advisory until 7 PM EDT this evening for PAZ034>036-

063>065.



&&



$$



SYNOPSIS...Steinbugl

NEAR TERM...Steinbugl

SHORT TERM...Lambert/Evanego

LONG TERM...Colbert

AVIATION...Martin/Bowen

CLIMATE...Banghoff

