


Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
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-- Discussion containing changed information from previous version are highlighted. --938 FXUS61 KPBZ 061735 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 135 PM EDT Sun Jul 6 2025 .SYNOPSIS...-- Changed Discussion --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.-- End Changed Discussion --&& .NEAR TERM /THROUGH TONIGHT/...-- Changed Discussion --KEY MESSAGES: - Major Heat Risk continues this afternoon for the Pittsburgh urban heat island. - Dry conditions expected through tonight. --------------------------------------------------------------- Temperatures have reached the mid to upper 80s early this afternoon underneath a scattered summertime diurnal cu field. Dewpoints have risen to the mid to upper 60s in many places, resulting in heat indices climbing into the low 90s in some spots already. Expect high temperatures to top out around or just above 90 degrees over the next few hours, with heat indices reaching the mid to upper 90s but remaining below Heat Advisory criteria. The cu field should dissipate once again 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 Monday morning as moisture continues to advect back into the region and winds remain light or calm.-- End Changed Discussion --&& .SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...-- Changed Discussion --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.-- End Changed Discussion --&& .LONG TERM /WEDNESDAY THROUGH SUNDAY/...-- Changed Discussion --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.-- End Changed Discussion --&& .AVIATION /18Z SUNDAY THROUGH FRIDAY/...-- Changed Discussion --A scattered cu field with cigs around 5kft AGL has developed across the area this afternoon, with generally light southwest winds at all area terminals. A high confidence VFR forecast remains in place through much of the current TAF period. Increasing mid-level cloud cover and shower/thunderstorm chances (and associated restriction potential) will work their way back into the northwestern half of the forecast area towards the tail end of the period as a cold front slowly approaches from the northwest. Introduced PROB30s to reflect this timing at ZZV and FKL, as well as in the extended portion of the PIT 30-hr TAF. Outlook... Daily thunderstorm chances (and associated restrictions) return Monday through the coming week, likely following a diurnal pattern with peak probabilities occurring each afternoon and evening.-- End Changed Discussion --&& .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...MLB NEAR TERM...Cermak SHORT TERM...MLB LONG TERM...MLB AVIATION...Cermak