Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 354 AM EDT Wed Sep 06 2017 Valid 12Z Wed Sep 06 2017 - 12Z Fri Sep 08 2017 ...Heavy rainfall possible from the Northeast the northern Mid-Atlantic today... ...Temperatures continuing to be well above normal for the Western U.S.... Scattered to widespread showers and thunderstorms are expected from New England to portions of the Carolinas as a cold front pushes through the East Coast. Areas of higher rainfall intensities is forecast from New Jersey to Maine; which may increase the risk for flash flooding. The front is expected to slow its eastward progression by the end of the work, pushing offshore by Thursday evening. An upper-level system behind this front moves slowly across the Great Lakes region which should keep showers and thunderstorms in the forecast for the Great Lakes region over the next couple of days. In the wake of the cold front, temperatures across the eastern half of the nation are expected to be as much as 5 to 10 degrees below normal. Strong upper-level ridging over the West will maintain the well above seasonal averages - with many locations across the Pacific Northwest reaching highs of 10 to 20 degrees above normal. Heat advisories, red flag warnings, and air quality alerts remain in effect. Much of the Northwest will remain dry through the middle of the week but monsoonal moisture should bring mainly diurnally driven showers and thunderstorms across the southern Rockies and the Southwest. By Thursday, a system moving towards central California may also increase moisture across the central West Coast which should also help to moderate the temperatures. Additionally, Tropical Depression Thirteen is forecast to be over the western Gulf through the the end of the work week. This feature will cause an increase in precipitation for South Texas by Friday. Although the exact track of major Hurricane Irma remains uncertain beyond 72 hours, confidence is very high Irma will be near the vicinity of the Bahamas, Dominica and Cuba by Friday. Rain will steadily increase today through the end of the week across Florida and up to the Southeast Coast as Irma approaches. Campbell Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php