Area Forecast Discussion
Issued by NWS Pittsburgh, PA

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667 FXUS61 KPBZ 070612 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 212 AM EDT Mon Jul 7 2025 .SYNOPSIS... Showers and storms return on Monday with a slow moving cold front. Some of the rain may be heavy with localized flooding possible. The boundary stalls Tuesday and an unsettled pattern will bring daily rain chances throughout the week along with near normal temperatures. && .NEAR TERM /THROUGH TODAY/... KEY MESSAGES: - Dry conditions expected through tonight. --------------------------------------------------------------- The afternoon diurnal cu field should dissipate around sunset with the loss of daytime heating, followed by another quiet night with the warming trend continuing as lows remain in the upper 60s to around 70 degrees. Some patchy fog and haze will be possible again late tonight into early Mon morning as moisture continues to advect back into the region and wind remains light or calm. && .SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/... KEY MESSAGES: - Hot on Monday with heat indices in the upper 90s. - Slow moving showers and storms Monday with a heavy rainfall and low-end severe weather threat. - Boundary slows and stalls across northern WV maintaining daily precip chances. ---------------------------------------------------------------- An upper trough enters the region Monday and begins to flatten out as it does so. Favorable timing of it will push Chantal`s remnants to our east as Bermuda high pressure helps deflect it to the north and east form the Carolinas. What we will see locally is a weak cold front extending southward from a low pressure system in Ontario slowly sweep through. Warm and moist advection will continue ahead of the boundary and give the region another chance to see high temperatures exceeding 90 degrees (60-90% south of I-80 but lower farther north owing to increasing cloud coverage). Heat indices will creep up into the upper 90s and some locales, especially urban areas and valleys, may see 100. With increasing cloud cover/heavy rain arriving in the afternoon, and the threat for advisory criteria very localized, opted for no heat headlines in coordination with neighbors. The front will creep into our forecast area by the late morning/early afternoon hours as convection fires along it aided by daytime heating. Some showers may be ongoing in the morning across northwest PA/eastern OH in weak pre-frontal convergence, but not seeing more widespread development until later. The environment will be supportive of heavy rain producers with ensemble mean PWAT values >1.75", MUCAPE near 1500 J/kg, deep warm cloud depths nearing 16,000 feet, and weak flow characterized by MBE vectors around 10 knots oriented close to boundary parallel. With the HREF in play, we have a better idea of what sort of rainfall rates/amounts could be possible. Probability for 1"/hour rates at any given hour tomorrow afternoon and evening is as high as 60% and pegs the I-80 corridor. Even 2"/hour rates aren`t completely off the table with some 10-20% blobs showing up. Total amounts through Monday night exhibit a 40-70% probability of one inch, and a 15-30% probability of two inches again with highest chances north of Pittsburgh. With some time to recover since our last heavy rain event, the area won`t be quite as hydrophobic, but soil moistures are still elevated, so a flash flood risk is certainly there and we remain in a Marginal Risk (1/4) for excessive rainfall. The other mention will be a low-end severe risk as a Marginal Risk (1/5) clips our northern counties. With the aforementioned destabilization, we`ll have the instability in play, but shear will be weak overall (<20 knots deep layer). This points toward a water loaded downburst threat given the PWATs, especially in any areas that would see just a bit of mid-level drier air intrusion and nudge up in DCAPE, which is possible to the north coincident with where we`re outlooked for severe. A hail threat is nearly null given the high moisture content and weak shear both detrimental to hail growth. The boundary really struggles to move headed into the middle of the week as mid-level flow parallels it. Latest ensemble clusters will peg northern WV as the most likely spot for it to sit with solutions coming into better agreement in the mid-levels. This is going to provide us with daily, diurnally driven rain chances within the proximity of the boundary as daytime heating fires showers and storms off of it. A relief from the higher PWAT air seems unlikely, so any of these showers and storms will be capable of locally heavy rainfall. Southern and eastern portions of our region have been included in a Tuesday Marginal Risk (1/4) for excessive rainfall. The highest precip probabilities will remain mainly south of the Mason Dixon line Tuesday along the front, though lower end probabilities will exist farther north. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... KEY MESSAGES: - Stalled boundary plagues the area with daily precip chances through the end of the week - Another system favored to move in over the weekend. ------------------------------------------------------------------- A similar story for Wednesday keeping highest PoPs south of Pittsburgh before low pressure tracking across the Great Lakes lifts the boundary back up north as a warm front. This will overspread higher precip chances to the area on Thursday and Friday as additional waves of low pressure ride along the front. We should finally rid our area of that disturbance just in time for another one to develop out of the Northern Plains and bring yet another unsettled pattern next weekend. Still some ensemble disagreement on how that evolves, but not seeing too much confidence in a dry weekend. Temperatures are favored to hold just above normal through next weekend, though with cloud cover and rain around, they may prove to be slightly cooler than currently forecast in spots. && .AVIATION /06Z MONDAY THROUGH FRIDAY/...
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Cumulus will develop later this morning as lower levels begin to mix and gust out of the southwest. Overall, winds will veer more westerly during the afternoon ahead of a slow- moving front. The mentioned front, which will cross in the afternoon to evening hours, will bring a chance of rain and thunderstorms with a conditional severe wind risk, most likely for FKL and DUJ. Cig restrictions are possible in cold advection behind the front Tuesday morning. Outlook... MVFR/IFR cig restrictions are possible in cold advection behind the front overnight into Tuesday morning. The rest of the week will be defined by diurnal storm chances each day.
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&& .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...MLB NEAR TERM...Cermak/AK SHORT TERM...MLB LONG TERM...MLB AVIATION...88