NEAR TERM /UNTIL 6 AM SATURDAY MORNING/
KEY MESSAGES:

- Patchy valley fog possible tonight.
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Smoke aloft will gradually clear to the south tonight, giving way to clear skies under subsidence and high pressure. The pressure gradient will remain weak with the surface high centered over the Finger Lakes of New York. These calm and clear skies will lend to efficient radiational cooling. This prompted nudging low temperatures toward the NBM 10th percentile and keeping fog confined to valley locations with rivers and creeks serving as a warm moisture source. Any fog is expected to clear rapidly beyond daybreak. Probabilities of dense fog remain 0% to 10%.

SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/
KEY MESSAGES:

- Remaining dry but becoming warmer.
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High confidence ridging builds for most of the short term period as an upper low cuts off to our east and troughing digs to our west maintaining dry weather locally. Ensemble mean 500 mb heights rise to 588-591 dm and, as the surface high slowly migrates east, southerly return flow will begin an increase in temperatures and moisture through the weekend. Probabilities for >90F remain at 0% to 20% for Monday and jump to 50 to 60% on Sunday primarily in river valleys and urban areas south of I-80. Dew points are forecast to tick from the upper 50s and lower 60s on Saturday to the low-to-mid 60s on Sunday. This should keep conditions feeling comfortable and heat risk low despite above average temperatures.

Ridging will begin to shunt to the east on Sunday as ensemble clusters absorb a cutoff upper low back into the flow aloft.
Generally good agreement amongst them on its amplification and track through the Ohio Valley provides overall high confidence in the evolution of the pattern which will introduce some high clouds from the west late on Sunday.

LONG TERM /MONDAY THROUGH FRIDAY/
KEY MESSAGES:

- A few rounds of disturbances pass into the middle of next week.
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Some disagreement in the ensemble clusters comes into play with how the other cutoff low to our east evolves, though most keep it around to a varying degree through the day on Monday. This scenario would favor a slightly drier solution, though if it departs quicker which is currently a less likely but still possible outcome, an approaching wave from the west will be allowed to move in quicker and support a wetter solution. Either way, rain chances increase on Monday and continue through mid- week with a series of disturbances as there is good agreement that the Northeast sits under a low amplitude trough under-cut by warm moist southwest flow in response to a strong developing ridge over the south-central United States. This pattern is climatologically supportive of severe weather chances, although many of the details may not be resolved until next week draws closer. Machine learning continues to paint a broad-brushed, low probability severe threat by mid-week.

With flow aloft extending downstream of the Canadian Rockies, prominent wildfire smoke could make another return to the Pittsburgh region, though fine details are usually resolved with two days lead time.

As of the most recent update, it appears that clusters are backing off the idea of extreme heat in the northeast to start off August. All clusters now retrograde the ridge axis back into the west, maintaining troughing in the east. This setup is less susceptible to extreme heat, but CPC maintains the moderate risk of excessive heat for now. Will continue to monitor for changes in the coming days.

AVIATION /22Z FRIDAY THROUGH WEDNESDAY/
VFR is expected through the TAF period as high pressure builds across the region. Early morning river valley steam fog is expected, though there is a low probability that the TAF sites will be affected. The CU rule and model soundings indicate scattered diurnal cumulus clouds will develop again Saturday, as light NE wind veers to the E.

Outlook
VFR will continue through the weekend under high pressure.
Periodic restriction potential in showers/thunderstorms returns Monday through Wednesday with a slow moving trough of low pressure.

PBZ WATCHES/WARNINGS/ADVISORIES
PA...None.
OH...None.
WV...None.