FXUS61 KPBZ 061109

AFDPBZ



Area Forecast Discussion

National Weather Service Pittsburgh PA

709 AM EDT Wed May 6 2026



.WHAT HAS CHANGED...

Updated aviation forecast, otherwise no significant changes 

were made to the forecast.



&&



.KEY MESSAGES...

1) Morning rain will clear to cooler and drier weather through

Friday, before more rain chances return over the weekend.



2) Frost remains possible tonight and Friday morning.



&&



.DISCUSSION...

KEY MESSAGE 1... 

Rain is expected to persist through this morning, before

clearing into the afternoon. With no additional instability 

expected between now and late-morning, rain will likely remain 

stratiform, with no additional convective or flooding concerns. 

The heaviest totals have been observed up in Mercer County 

(~0.5" as of 1am); ensembles suggest most likely totals by the 

end of the event in the I-80 corridor will be around 0.75", with

a 30% chance of >1". Chances of >1" rapidly decrease to the 

south and east, with chances generally >15% elsewhere. 



Drier and cooler weather is expected Thursday and Friday 

courtesy of the post-cold-frontal environment and a brief bout 

of high pressure. Chances of rain increase again late Friday 

and through Sunday night. Chance Friday and Saturday will be 

courtesy of a couple of weaker shortwaves. The brunt of rainfall

accumulations is forecast Sunday with the next low pressure 

passage and cold front. Chances of >1" right now are generally 

<20% and the system seems generally progressive in most 

scenarios, which would keep flooding concerns low. 





KEY MESSAGE 2... 

There is medium to high confidence in clouds scattering some

overnight tonight north of Pittsburgh as high pressure 

gradually builds in. With it, the pressure gradient will also 

relax and calm overnight winds with decoupling. NBM probabilities

of temps less than 37F tonight are generally 30% to 50% north 

of Pittsburgh, but chances of a freeze are <5%. Thus, there is a

low probability of a frost tonight. Most instances will likely 

be isolated and patchy depending on micro- scale terrain 

influence.



A similar regime will linger Friday morning, with a higher 

chance of low clouds clearing area-wide. This will correlate to

a bit higher chances of a frost, with regions north of 

Pittsburgh and the higher terrain of PA/WV seeing a 50% to 80% 

chance of less than 37F, and the rest of the region generally 

between 10% to 35%. Chances of a freeze are, again, low for 

now, highest at 10% to 25% for Forest County and eastern Tucker 

County.



&&



.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...

Though the heavier rain exists east by 14z, residual light

rain/drizzle plus delay in the surface frontal passage will hold

and further spread IFR to locally LIFR conditions this morning.

Dry advection and subsidence working from the west offers

ceiling improvements starting in the late morning hours through

this evening, with moisture convergence delaying VFR timing at

the southeastern-most sites (KLBE/KMGW).



Gradual clear of clouds below 5kft is expected this evening,

with cirrus exiting thereafter. Hi-res modeling is very bearish

(less than 10%) on fog development, the late arrival of drier

air near KMGW plus overnight clear could allow for a brief

visibility drops near dawn.



Outlook... 

Isolated showers could develop with peak heating Thursday 

afternoon areawide with additional showers (and low probability 

restrictions) possible overnight north of I-80. Then, rain and 

restrictions develop Friday afternoon into Saturday, starting a

trend of intermittent periods of rain/restrictions associated

with passing shortwaves within the broad Great Lakes troughing.



&&



.PBZ WATCHES/WARNINGS/ADVISORIES...

PA...None.

OH...None.

WV...None.



&&



$$



DISCUSSION...Milcarek

AVIATION...Frazier