We promise a “deep dive” into the meteorology in our Insights segment, and Matt Noyes delivers today! It’s not short – but you’ll understand all the inner workings of Friday’s severe thunderstorm risk by the time you’re done watching. As Matt reminds us, our Noyes’ 1°Outside Weather Network App is your best tool everyday, but especially on thunderstorm days.
Current Analysis
A cold front is positioned across the Great Lakes and is set to arrive in New England by Friday afternoon. As this front slices into the warm and humid air mass, thunderstorms are likely to develop.
Friday’s Weather Setup
- Warmth and Humidity: Expect dew point temperatures nearing 70 degrees, indicating very humid conditions across southern New England.
- Thunderstorm Timing: Most of the day will be dry in Southern New England, but the risk of showers and storms increases by the afternoon and evening. Northern New England will see earlier development of storms, which will keep temperatures slightly cooler there.
Atmospheric Energy Indicators
- CAPE (Convective Available Potential Energy): This measure of thunderstorm energy will be high, around 1,000-2,000 joules per kilogram, spanning from central Pennsylvania through New York into New England. Higher values indicate a greater chance of thunderstorms.
- Jet Stream Energy: A shortwave trough (a dip in the jet stream) from Michigan will destabilize the atmosphere by mid-afternoon, further enhancing storm development.
Storm Development and Timing
- Late Morning to Midday: Showers and storms will start in New York and the mountains, moving into western Massachusetts by 3 PM, then into central New Hampshire and the Maine coast.
- Early Evening: The Massachusetts Turnpike and areas north of Boston will see the highest storm chances around 6 PM.
- Late Evening: Storms will slow down as they encounter cooler Atlantic air, reducing the severe weather threat in Southeast Massachusetts but increasing the risk of localized flash flooding from Hartford to Worcester and into southern New Hampshire and Maine.
Flash Flooding Risk
The Weather Prediction Center has highlighted a flash flood risk due to slow-moving downpours expected during the late day and evening.
Weekend Outlook
- Saturday: Showers may linger, especially from Boston to Gloucester points southeast in the morning, even popping up in Southeast areas during the midday. The day will start humid but will gradually turn less humid as the wind shifts to the northwest.
- Sunday: Expect exceptional weather with cooler temperatures along the coast due to a sea breeze. Highs will be around 80 degrees.
Next Week
The warmth is expected to build again, continuing the summer-like pattern.
Stay Safe
Be prepared for thunderstorms and potential flash flooding on Friday. Use the 1DegreeOutside app for real-time updates and radar tracking. Stay informed and stay safe.
