Weather Underground Forecast for Friday, April 19, 2013.
Severe thunderstorms will continue spreading across the Eastern states on Friday as a low pressure system over the Great Lakes continues pulling a cold front eastward. Warm and moist air from the Gulf of Mexico will pour in ahead of this front, producing more showers and thunderstorms. These conditions will allow for severe thunderstorms to develop with large hail and strong winds, with possibly a few tornadoes. If severe thunderstorms develop, they will most likely be contained to the Mid-Atlantic states from South Carolina through Washington D.C. Meanwhile, the northern side of this system will allow for snow showers to taper off for the Upper Midwest and Great Lakes as the system pulls northeastward and further into eastern Canada. High pressure building in behind the low pressure system and associated cold front will push cooler air in from the North, allowing for chilly conditions to spread across the Eastern Valleys on Friday. Expect highs to range in the 50s to lower 60s for the Mississippi River Valley and Tennessee Valley.
Out West, another system moves into the Pacific Northwest from the Gulf of Alaska. This will pull Pacific moisture onshore, kicking up rain and mountain snow showers across Oregon and Washington. Precipitation from this system will spread into the Intermountain West and Northern Rockies as it advances eastward throughout the day.
Temperatures in the Lower 48 states Thursday have ranged from a morning low of -9 degrees at Yellowstone, Wyo. to a high of 98 degrees at Port Isabel, Texas