The Pittsburgh area braces for a bout of severe weather today, as the National Weather Service in Pittsburgh forecasts "strong to severe thunderstorms this afternoon and evening ahead of a cold front," with a risk of isolated flooding due to heavy rainfall. As temperatures are set to climb through the weekend, residents can expect a tempestuous end to their Wednesday after what will start as a warm, balmy morning.
Experts warn of "strong to severe storms expected between 1 pm to 8 pm" with "damaging winds will be the main threat." According to an early morning update from the National Weather Service, Pittsburgh PA, there is also a possibility for "isolated tornadoes and hail as large as a quarter" which can't be entirely ruled out, despite the Storm Prediction Center (SPC) having removed the 2% tornado outlook for the day. The Weather Prediction Center (WPC) continues to signal a Marginal risk for flooding, a concern further exacerbated by the predictions of machine learning outputs that the weather service mentioned.
The region, starting from the Ohio River Valley, woke up to warm conditions, with low temperatures floating in the range of upper 60s to low 70s. The stability of the atmosphere will be influenced by diurnal heating throughout the day, which could catalyze the development of severe weather conditions. The NWS Pittsburgh notes that "by late evening, the severe threat will likely evolve into a heavy rain threat," particularly for urban areas that may experience "training or rainfall rates ranging from 2-4 inches per hour." With precipitable water values (PWATs) well above seasonal averages, urban areas might witness significant downpours leading to flash flooding.
By Thursday, a sigh of relief is in sight as dry conditions are forecasted to return with the establishment of high pressure across the region. The reprieve will be accompanied, however by a rise in temperatures, potentially reaching the mid-90s over the weekend due to increasing low-level moisture and high 500 millibar heights. The weekend forecast appears to be a mixed bag, "Shower and thunderstorm chances return Saturday into Sunday with the next low-pressure system," the NWS Pittsburgh explains. The onset of the coming week may bring calmer skies, with high pressure expected to take charge once again.
Travelers and aviators should expect VFR conditions throughout the morning, but should be prepared for disruptions as "pre-frontal showers and storms will increase in coverage from west to east after 17Z." Taking a cautious stance, the National Weather Service advises a potential for "strong wind gusts and hail" in the storms later in the day, with a period of MVFR and possible IFR conditions following the thunderstorm activity. The most recent aviation outlook from the NWS indicates that these conditions should give way to VFR by Friday under returned high pressure.
No advisories, watches, or warnings were in effect as of the latest update from the National Weather Service Pittsburgh PA, but the ever-dynamic nature of weather systems suggests that residents and visitors alike keep a close eye on updates as the day progresses.
