Pittsburgh residents should be prepared to keep their umbrellas at hand and their weather radios on, as the National Weather Service (NWS) in Pittsburgh predicts a stormy forecast. The latest updates from the NWS, communicated via an Area Forecast Discussion, indicate that the city can expect continued showers and thunderstorms, potentially leading to localized flooding through Friday, with the stormy pattern expected to persist into the following week.
For today, the risk of flooding is deemed slight, although forecasters confess to low confidence in predicting a widespread flood event. Thunderstorms may occur predominantly from noon to 10 p.m., and residents should be aware of potential wet microbursts during this time. The primary concern, however, revolves around flash flooding, spurred by heavy rains capable of dumping an average of 1-2 inches per hour, with possible bursts up to 3-4 inches.
The absence of a Flood Watch may seem puzzling amidst such volatile predictions. Still, the National Weather Service has its reasons: the latest high-resolution weather models are showing little in the way of strong convergence or forcing that would result in steady storms, and an anticipated increase in mid-level winds is expected to push storm motion to approximately 15-20 knots. Moreover, a lack of preceding heavy rainfall has kept flash flood guidance relatively high.
Thursday's forecast is equally precarious, with heavy rain showers and thunderstorms potentially favoring the southern half of the forecast area. However, model predictions exhibit high variability in storm coverage, resulting in significant uncertainty for forecasters. Depending on the location of a surface cold front and a possible assist from a lake breeze off Erie, conditions could vary markedly across the region. Some areas may experience drier and cooler weather, while others could see the axis of greater storm coverage shifting along or south of the I-70 corridor.
Looking further ahead, no respite seems imminent for Saturday as earlier models, which hinted at a possible break, have now changed course, projecting an extension of the weather pattern into next week. Even though the exact flood and severe weather potential remains highly uncertain and will likely be influenced by the outcomes of preceding days, residents should be wary as the conditions continue to develop favorably for thunderstorms and potential severe weather events.
The aviation outlook also brings cautionary notes for pilots and travelers, noting VFR tonight, but increasing cloud cover alongside scattered showers by morning, which will escalate into numerous thunderstorms in the afternoon. The expected diurnal instability may trigger conditions of MVFR and IFR around thunderstorms, along with the possibility of fog and stratus forming in the saturated low levels due to the day's rainfall.
