Thursday, August 09, 2012

Potentially Wet To Start & Stormy To End

Thunderstorms around the region today have produced some pretty impressive wind and hail reports, with half to one inch hail in parts of Chester and Montgomery Counties, winds to 52 miles per hour at Pottstown Airport and 56 in Trenton, and tree damage in a number of spots. While spotty, thunderstorms did pack some wallop with them.  More thunderstorms are possible through the night, especially towards morning.  A disturbance in the atmosphere is currently over Ohio and West Virginia and will lift northeast towards us overnight.  Those thunderstorms you see on the radar image below will push towards us through the night.

Should they hold, they will work into the Delaware Valley towards daybreak tomorrow morning.  These should not be severe but they could produce heavy rainfall and some loud thunder as they move northeast.  Timing for these storms would be between 4 and 9 AM from southwest to northeast, so the morning commute into work could be impacted if these storms do indeed hold together through the night.

It will not storm all day tomorrow -- there appears to be a bit of a break in the afternoon hours in between wave number one and the cold front itself as it pushes into Pennsylvania.  Thunderstorms will fire up along the front during the afternoon hours in Western Pennsylvania and advance towards Philadelphia during the early evening hours.  The NAM (below) shows its thinking at 8 PM, with thunderstorms just about into the western suburbs.  The Euro paints a similar scenario but a bit earlier -- generally around or just after the dinner hour on timing for those thunderstorms.  This second line could be the severe thunderstorm line (if one develops).  Gusty winds and perhaps hail could accompany this -- in addition to any additional heavy rainfall that could result.

Rainfall amounts in the heaviest thunderstorm activity could exceed a couple of inches -- the best chances for this will be from Lancaster to Allentown to the Poconos and into Northwest Jersey -- however any one location could see an inch or more of rain in heavier thunderstorm activity as it moves through tomorrow.

Track any storms tonight on the current weather page.