Monday, September 17, 2012
Slight Risk Continues For Tomorrow
A slight risk for severe weather remains in place for tomorrow for our region. We have a three in ten chance (as of this afternoon) of any one location getting severe criteria wind (58 mph or greater) within 25 miles of it, with the black "hatched" area picking up a one in ten chance of 75 mph winds. Those odds, especially the 30% one, may very well be bumped tomorrow and we could end up seeing a moderate risk for severe weather around the region. More on the timing and setup on the squall line in a bit.
The front is going to have some dynamics and pop to it -- wind at 5000 feet above the ground is modeled to be anywhere between 60 and 80 mph in our region as the front passes through tomorrow evening. The low, which will pass to our northwest, is progged to intensify and as it deepens we should see a squall line of wind-whipped rain develop and march east with the front. Timing on the front varies amongst the various models but a general consensus suggests the squall line should move through the region starting from 5-8 PM (west) and reaching Philadelphia anytime from 7-10 PM. It might be notch later but I think these times will hold as a general rule of thumb.
Rain will be heavy with the front as it moves through (illustrated below with the Euro's depiction via Wunderground.com) but winds will be the bigger story. Winds could gust to 70 mph, if not higher, in the strongest of cells within the squall line. While thunder may be limited, the gusty wind potential will not be. A few tornadoes can't be ruled out in parts of the region as well tomorrow afternoon and evening...I think the "best" chance of that will be in Central into Northeastern Pennsylvania.
You can track the rains tonight as they approach and move in through our current weather page.