Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 440 PM EDT Wed Jun 26 2013 Valid 00Z Thu Jun 27 2013 - 00Z Sat Jun 29 2013 ***Active weather pattern from the Great Lakes to the East Coast*** ***Hot and humid with scattered storms for the East Coast*** ***Major heat wave expected for the Desert Southwest*** A few frontal boundaries from the Upper Midwest to the Ohio Valley will provide the forcing necessary for showers and thunderstorms to develop through Thursday. A wave of low pressure is forecast to move from the Upper Great Lakes to New England, producing showers and thunderstorms with locally heavy rainfall, over the Great Lakes and into the Ohio Valley. Over the eastern half of the U.S., the Bermuda High will continue to control the weather pattern through Thursday. Deep southerly flow from the Gulf of Mexico, along with weak shortwave energy aloft, will lead to the development of scattered showers and storms for much of the East Coast. It will also be hot and humid with highs in the upper 80s to mid 90s. A weak cold front will approach from the Ohio Valley by the end of the week, before stalling out near the coast. Daytime highs will likely be several degrees cooler, but it will continue to remain quite humid with continued chances for thunderstorms. For much of the Desert Southwest, excessive heat warnings are in effect for a major heat wave that is expected to affect the lower elevations of eastern California, Arizona, and Nevada starting Friday. A big upper level high, combined with subsiding air and abundant sunshine, will lead to the hottest temperatures so far this year. Some of the lower Deserts near the Colorado River may reach 120 degrees! It will also be very hot for the lower elevations of Utah and into Northwest Mexico. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php