It’s safe to say that after a spring filled with chilly, overcast, and windy days, we’ve made significant progress in the last ten days. The hot and sticky weather will persist, unless you’re in Pennsylvania’s mountains, where it’s just delightfully warm!
Along with the hot and sticky weather in late June and July, there is always the possibility of thunderstorms, which is why we’re all here today! Unfortunately, because May was so rainy, flash flooding will likely be a hazard throughout the summer.
Storms on Monday and Tuesday will form before and then along a cold front, posing the primary threat of severe winds. Of course, with so much instability accessible, regular lightning poses a risk.
Monday’s Severe Thunderstorm Risk
We expect scattered showers and thunderstorms to form late Monday afternoon. A couple may be on the stronger side at this stage, particularly as dinnertime approaches. Here’s the Hi-Res NAM Future Simulated Radar for 4:00 PM Monday.
Western Pennsylvania appears to be the most active Monday evening, with scattered to widespread thunderstorms anticipated. Some of them may be stronger than others, and there is also the risk of flash flooding.
Monday’s Severe Thunderstorm Threat Forecast
The cold front will move through on Tuesday, although the exact date is uncertain. Should there be a slight delay, the threat will shift to the northwest across much of Northern Pennsylvania. The high risk will focus on Eastern Pennsylvania if it is not delayed.
The Hi-Res NAM delays the front more than other models, triggering a devastating line of storms across Western Pennsylvania Tuesday afternoon. Also, storms are developing in Eastern Pennsylvania.
If there is a tornado hazard, it will be from cells that form ahead of the main line across eastern Pennsylvania. Here’s what it looked like at 4:00 PM on Tuesday.
By 8:00 p.m. Tuesday, the Hi-Res NAM predicts extensive thunderstorms across the eastern half of the state. Some of these will probably be severe.
Tuesday’s Severe Thunderstorm Threat Forecast
Area A: Scattered strong to severe thunderstorms are expected. The greatest threats are damaging gusts of up to 65 miles per hour and frequent lightning. Isolated hail and a very isolated tornado threat are also possibilities.
Area B: Isolated strong to severe thunderstorms are probable. The major dangers include gusty gusts, frequent lightning, and localized urban flash flooding.