Area Forecast Discussion
Issued by NWS Pittsburgh, PA
Issued by NWS Pittsburgh, PA
745 FXUS61 KPBZ 100626 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 226 AM EDT Mon Aug 10 2026 .WHAT HAS CHANGED... The overall forecast remains the same, and confidence in details of timing and location of strongest storms remains fairly low. && .KEY MESSAGES... 1) Daily shower and thunderstorm chances return today and remain in the forecast through at least Thursday with both the potential for strong/severe storms and heavy rainfall. && .DISCUSSION... KEY MESSAGE 1... A convective line crossing north of Pittsburgh, the remnants of earlier stout storms, are producing mainly brief heavy rain and wind gusts of up to 40 MPH as they cross. These, as well as weaker activity to the south, should exit to the east by sunrise. After a brief break later this morning, additional convection is likely to arrive by midday/early afternoon, likely the continuation of activity currently near the southern end of Lake Michigan. Another round is then possible after sunset with a shortwave passage. While exact timing and evolution of afternoon/evening convection remains in question, there is still a decent level of confidence in the presence of an environment conducive for severe storms. Model soundings suggest mean-layer CAPE values will be in the 1500 to 2000 J/kg range during the peak heating period, with deep-layer shear on the order of 25 to 35 knots. This will support organized convection with mainly a damaging wind threat, both from cold pool consolidation and downburst potential (DCAPE of around 1000 J/kg). Some at least transient supercell structures/rotating storms are also possible, thus the threat for a tornado or two cannot be ignored. For Tuesday (and potentially Wednesday as well), the main threat corridor shifts south a bit, with the best potential for severe storms mainly south of I-70 (matching SPC`s day 2 Slight Risk area). This is where richer instability will reside during the afternoon and evening. Again, damaging winds appear to be the primary threat, as this may be the more favored region for convective complex passage. The more concentrated wind damage threat area likely remains just to the south of our region, but could clip portions of at least eastern Ohio. In addition to severe threats, there remains the risk of flash flooding. Given precipitable water values lifting back into the 1.6 to 1.7 inch range (90th to 95th percentile in the climatology), as well as the potential for multiple thunderstorm complexes, WPC continues to highlight our region in a Slight (level 2 of 4) Risk for excessive rain for today into Tuesday night, with the main heavy rain threat area shifting south of the Mason-Dixon Line by Wednesday. 48-hour NBM mean precipitation totals are in the 1.5 to 2.5 inch range generally south of US-422, with 90th percentile totals in the same area of 3 to 4 inches. Given the still relatively moist soil across the region, such rainfall totals could create at least isolated flash flooding issues in the heavier convection. Still, with the uncertainty in timing and location of the greatest potential, will hold off on the issuance of a Flood Watch at this time. By Thursday, both heavy rain and severe weather threats should begin to subside as a stronger Great Lakes shortwave pushes a boundary across the area, leading to less threatening weather. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... VFR is generally favored outside of convective periods, though diurnal heating/mixing between 13z-18z Monday may yield brief MVFR cu. Current thunderstorm line north of Pittsburgh should affect DUJ briefly with IFR visibility in heavy rain, as well as a wind gust to 30 knots. Timing of future thunderstorm complexes remains tricky today. Two general rounds are foreseen during the TAF period: one from 14Z to 20Z, associated with current southern Great Lakes storms, and another mainly after 00Z with a shortwave passage. These details are subject to change as the mesoscale environment evolves. In any case, storms will be capable of brief IFR to LIFR visibility as well as gusty wind - perhaps to between 40 and 50 knots peak in the strongest storms, and even hail is a possibility. Such winds are more likely with the daytime activity as opposed to the evening storms. The current TAFs represent best guess timing based on latest available data but is of low confidence. Outlook... Active weather through much of the week with varying rounds of showers and thunderstorms. Timing of storms for a given day is likely to be of lower confidence and dependent on upstream storm progression. Most restrictions during this period will be tied to storm activity and/or morning fog/stratus resultant of rain plus overnight clearing. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ DISCUSSION...CL AVIATION...CL/Frazier