FXUS61 KPBZ 261623

AFDPBZ



Area Forecast Discussion

National Weather Service Pittsburgh PA

1223 PM EDT Thu Jun 26 2025



.SYNOPSIS...

Hot and humid through the end of the week with daily afternoon 

storm, isolated flooding, and severe wind chances. Rain chances

decrease Sunday, followed by another active period Monday to

Tuesday before temperatures return to near normal and conditions

trend slightly drier mid-week.



&&



.NEAR TERM /THROUGH TONIGHT/...

KEY MESSAGES:



- Heat concerns continue through the afternoon for most of the

  area, with indices approaching 100F, hottest for valley and 

  urban locations.

- A marginal chance of severe wind and flooding into the 

  afternoon and evening with downburst potential.

---------------------------------------------------------------



Heat concerns linger through the period with mostly the effects

of cumulative heat stress. While we anticipate that heat will

not be as warm as days prior (40% to 80% chance of heat 

indices >95F in the Heat Advisory Area). Impacts will be 

highest for valley and urban locations given anticipated highest

heat indices and stresses on existing infrastructure. 

Additionally, the impacts may be higher for areas that do not 

receive rain and are not impacted by a cold pool, though the 

exact locations remain low confidence up to a couple hours 

before occurrence. In areas impacted by rain or cooler 

temperatures, there may be some relief this afternoon. 



As for the severe threat, the 12Z morning sounding has shown a

mostly saturated profile with weak, generally westerly, flow.

DCAPE is not as stark as the day prior, but SPC mesoanalysis

shows pockets of 800 J/kg to 1000 J/kg moving overhead with

roughly 1500 J/kg to 2000 J/kg of MLCAPE. A mature cell in this

environment will be capable of producing downburst wind 

threats. RAP analysis indicates a freezing level of roughly 

13kft as of noon and the -10C to -30C layer between 19kft and 

28kft. A developed cell ingesting liquid water in an updraft 

into this level would be most opportune to develop an icy core.

The higher the cell develops and the broader the cell is, the 

moore likely severe criteria may be met at the surface when the 

core falls out.



In tandem with the wind threat will come the flooding threat.

The morning sounding still has an anomalously high 1.68" PWAT

reading. With weak westerly flow, we would expect storms that

develop on the west side of cold pools (up-shear) to be mostly 

stationary. Unlike yesterday, flow aloft is westerly, so anvils

may blow east and leave this side of developed cells in

comparatively clearer skies, and potentially more instability.

These reasons are all supportive of an afternoon/evening flood

threat that slightly lags the severe threats. 



Development is generally expected in the 1pm to 3pm timeframe as

the convective temperature in the upper 80s are reached. The

most likely area for development today may be along the rugged 

cumulus between Cleveland and Pittsburgh, perhaps aggravated by

an inland penetrating lake boundary.



Into tonight, convective coverage is expected to drop off,

though elevated instability may keep a very isolated shower or 

two. Nonetheless, threat chances would be lower should any rain

develop. Dew points in the upper 60s and low 70s will keep 

temperatures anomalously warm, with a 30% to 70% chance of 

staying above 70F overnight, highest for the urban and valley 

areas. This has justified the continuation of the heat advisory 

with cumulative heat stress.



&&



.SHORT TERM /FRIDAY THROUGH SATURDAY/...

KEY MESSAGES:



- Heat concerns continue on Friday; heat advisory will be in 

  effect through 8pm Friday.

- Daily downburst wind and flooding threats in the afternoon and

  evening continue through Sunday.

----------------------------------------------------------------On Friday, chances of >90F are again highest for valley and

urban locations, with NBM showing a 20% to 40% chance. Heat 

indices could push 100F in these areas yet again. This will 

justify the continuation of the heat advisory through 8pm 

Friday. Environmental parameters will be similar as days prior, 

with LREF showing 1000 J/kg to 1500 J/kg MLCAPE, 600 J/kg to 800

J/kg DCAPE, and weak shear from the southwest with up-shear 

flooding potential. Chances again taper off at night. Low 

temperatures have a >50% chance of lows >70F again south and 

west of Pittsburgh Friday night.



Daily thunderstorm, downburst wind, and flooding threats

continue for the weekend during the afternoon/evening hours.

Initiation may be a bit more likely on Saturday as a front sags

south across the the center of the forecast area, and the front

may be a bit more likely south of I-70 Sunday as the front

continues its southward sag. 



Both the southward sagging front and increased cloud cover

potential may keep temperatures a few degrees cooler into the

weekend. Most spread in temperatures is between the mid-to-

upper 80s. This will still be climatologically warm, but cooler 

in perspective, which may allow heat risks to temporarily 

reduce.



&&



.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...

KEY MESSAGES:



- Potential for storms and locally heavy rainfall through at

  least Tuesday and possibly on Wednesday.

-------------------------------------------------------------------



Sunday night will feature the potential of some lingering

showers and thunderstorms but the overall convection should

weaken with sunset and loss of daytime heating. This is

especially the case since temperatures have cooled off a tad. 

Expect a brief warmup Monday, there is some indication of a 

brief troughing pattern by the middle of next week, though there

are some uncertainties in exactly how strong the trough will 

be, as indicated by clustered variability. The threat of

unsettled weather will likely continue.



&&



.AVIATION /16Z THURSDAY THROUGH MONDAY/...

Patchy fog has plagued a few sites this morning, mostly those

that saw rain yesterday, with restrictions ranging from MVFR

down to LIFR with light wind and clear skies. Expect that as we

heat this morning, mixing will quickly commence and allow for

any restrictions to diminish within an hour to two after

sunrise.



Scattered thunderstorms are expected to develop this afternoon

and evening in a similar manner to Wednesday as convection 

fires in the vicinity of a quasi-stationary front across the 

region. Included a prob30 for thunder, variable wind gusts, and

associated restrictions at all airports during the most likely 

time of occurrence.



Convection should wane again this evening with the loss of

daytime heating and diurnal instability. Mid-level clouds 

should linger into the evening with VFR expected. 



Outlook... 

Patchy MVFR/IFR in fog/stratus is expected Friday morning with

low level moisture in place. More numerous showers and

thunderstorms are expected Friday and Saturday afternoon and 

evening as the front wavers across the region. 



There is a lesser potential for afternoon showers/storms on 

Sunday as high pressure briefly brushes by to the north. 

Showers/storms return again Monday with an approaching cold 

front.



&&



.CLIMATE...

Daily record high maximum (left) and daily record high minimum (right)

temperatures for Thursday are listed below.



Thursday June 26th

Pittsburgh, PA:         95F (1966)              75F (1952)

Zanesville, OH:         97F (1952)              73F (1952)

Morgantown, WV:         96F (1952)              74F (1952)

Dubois, PA:             91F (1966)              66F (2000)

Wheeling, WV:           96F (1943, 1952)        73F (1952)

New Philadelphia, OH:   99F (1988)              71F (2022)



&&



.PBZ WATCHES/WARNINGS/ADVISORIES...

PA...Heat Advisory until 8 PM EDT Friday for PAZ013-014-020>022-029-

     031-073-075.

OH...Heat Advisory until 8 PM EDT Friday for OHZ039>041-048>050-

     057>059-068-069.

WV...Heat Advisory until 8 PM EDT Friday for WVZ001>004-012-021-509-

     510.



&&



$$



SYNOPSIS...Milcarek

NEAR TERM...Milcarek

SHORT TERM...Milcarek/Shallenberger

LONG TERM...Milcarek/Shallenberger

AVIATION...WM/MLB

CLIMATE...MLB

