Squall Line of Severe Thunderstorms Packing Damaging Winds & Hail Likely Sunday

        A line of severe thunderstorms associated with an approaching cold front is expected Sunday Afternoon into the Evening across Central and Eastern PA. It will likely come in the form of a squall line or bow echo. One thing that they both have in common, damaging winds.

        Damaging winds will be the main threat Sunday, likely between 58-70mph in storms that are severe. Although mid-levels of the atmosphere will be on the warm side, hail will also be possible in the strongest of storms.

        The line will begin to form in Western PA around noon-time Sunday, but will not begin to become severe until it moves into Central PA, where conditions will be more conducive for potent cells. Furthermore, we are watching the possibility of storms coming up from the Maryland area, into SE PA ahead of this line. These storms have the best chance at forming spin-ups (weak tornadoes). Besides that, the higher tornado threat will remain in Maryland and Virginia.

        We have created a more well thought-out scale. We have also done this to limit the amount of confusion between our page and the SPC. The new key is under our newly updated map below.

        Here is our Main Thunderstorm Risks Graphic, indicating which severe storm element looks most probable.

        Finally, we understand that TIMING matters to many of you so we have created an estimated thunderstorm timing graphic.

        We will be posting all SPC/NWS watches and warnings issued Sunday, so be sure to like our facebook page to stay informed by clicking here. Stay safe everyone!

        If you would like to view the Storm Prediction Center’s Sunday Outlook, click here!

        If you would like to see what the NWS State College has to say about Sunday’s Threat, read below. This is a screenshot from their most recent forecast discussion.