FXUS61 KPBZ 191120 AFDPBZ Area Forecast Discussion National Weather Service Pittsburgh PA 720 AM EDT Tue Aug 19 2025 .SYNOPSIS... High pressure will maintain dry weather today. Scattered shower and thunderstorm chances will return tonight and Wednesday with a weak cold front. After seasonable temperatures Wednesday, highs will gradually warm into the weekend. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Dry weather today with increasing clouds this evening --------------------------------------------------------------- Warm and dry conditions expected again today, and mostly to partly sunny skies will push high temperatures back into the upper 80s; lower 80s across the I-80 corridor and higher terrain. Clouds will likely increase later this evening with an approaching disturbance from the west. Probabilities increase between 8pm to 11pm for isolated light showers in eastern Ohio/near Lake Erie. However, elevated dry air may evaporate precipitation before reaching the ground. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... KEY MESSAGES: - Scattered shower/storm chances return tonight and Wednesday - A few higher terrain showers possible Thursday afternoon - Rainfall amounts remain low ---------------------------------------------------------------- Weak low pressure will cross the eastern Great Lakes by this evening as the previously stalled front to our south lifts north as a warm front. Scattered rain chances will increase overnight ahead of the trailing cold front, dissipating in the wake of the front by Wednesday afternoon/evening. Upslope showers across the ridges may linger through the afternoon. All indications are that precipitation will be widely scattered, with some locations receiving very little rainfall. Probability for >0.25" remains at 60% or lower, with highest values north of Pittsburgh. Still, modeled PWATs for Wednesday morning are anomalously high and range from 1.8 to 2.0". Though unlikely, if deeper convection is able to develop, localized flash flooding can't be ruled out. Renewed high pressure across the Great Lakes and Ohio Valley should keep most of the area dry overnight into Thursday. However, weak troughing could help to initiate stray diurnal showers primarily over the ridges Thursday afternoon. With Hurricane Erin to our east, flow will be out of the northeast on Thursday. Near to just below average high temperatures are expected through mid-week. Overnight lows remain a few degrees above average. && .LONG TERM /FRIDAY THROUGH MONDAY/... KEY MESSAGES: - Above average temperatures expected into the weekend - Precipitation chances return Saturday into Sunday with a passing cold front - Cooler weather begins next week ------------------------------------------------------------------- Extended forecasts indicate that a ridge of high pressure over the Ohio River Valley will be present into Friday, bringing mostly dry conditions and temperatures that are near to above average. A passing cold front and an upper-level trough will likely increase the chances of precipitation over the weekend, but rainfall amounts this far out look paltry at best. NBM PQPF for >0.25" range from just 20% west of Pittsburgh to 50% east. Of note, machine learning does indicate a 5 to 15% chance of severe weather with this passing front on Sunday, so this will need to be monitored in the coming days. Generally high confidence exists in persistent eastern CONUS troughing by early next week. This should keep temperatures below average through at least early week. && .AVIATION /11Z TUESDAY THROUGH SATURDAY/... Afternoon cu will be favored with bases around 5-7kft. The gradient will tighten a bit ahead of approaching weak low pressure with winds veering more southerly around5-10 mph. Outlook... Overnight into Wednesday, a weakening upper-level trough approaching from the northwest will increase shower/thunderstorm chances, which could result in temporary cig restrictions. Thursday, VFR conditions will return with ensembles strongly favoring high pressure and dry weather through the end the week. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && $$ SYNOPSIS...Rackley NEAR TERM...Hefferan/Rackley SHORT TERM...Rackley LONG TERM...Hefferan/Rackley AVIATION...MLB/88