Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 439 PM EDT Wed Jul 17 2013 Valid 00Z Thu Jul 18 2013 - 00Z Sat Jul 20 2013 ***Heat wave for the Eastern U.S. through the week*** ***Wet pattern for western Texas into the Southern Rockies*** ***Showers and storms near Canadian border with a cold front*** The heat and humidity is here for a few more days for the Eastern U.S., including the Mid-Atlantic, Northeast, Ohio Valley, and spreading into the Midwest and Great Plains. A large upper level ridge and sinking air in the lower atmosphere are causing the hot conditions. Although this is the hottest weather so far this season, it is less than the extreme heat observed last summer over these areas. Isolated showers and thunderstorms may provide temporary relief, but these are not expected to become widespread until a front approaches from the north by the end of the week. An unusual feature of the upper level pattern is a retrograding upper level low over the Southern Rockies. This system began its trek from the East Coast several days ago, and is forecast to bring more rainfall to much of the Southwest U.S. and western Texas. This will also be in combination with the monsoonal flow from Mexico, which will further increase shower and thunderstorm coverage. Elsewhere, a band of scattered showers and storms is likely from North Dakota eastward to the Upper Great Lakes and New England. This is where a frontal boundary is expected to remain for the next couple of days, and convergence along this front will aid in developing convection and rainfall. Dry weather is expected for the West Coast, which is typical for this time of year. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php