Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 351 AM EDT Thu Jul 09 2015 Valid 12Z Thu Jul 09 2015 - 12Z Sat Jul 11 2015 ...Flash flooding possible for the higher terrain of northern California and Nevada, portions of the central Plains, as well as portions of the central Appalachians and the northern Mid-Atlantic... ...A slight risk for severe thunderstorms is possible across the northern Mid-Atlantic region on Thursday... ...Above average temperatures continue through the week for the Pacific Northwest... An area of low pressure currently moving through the Ohio Valley will push into the lower Great Lakes and eventually the northern Mid-Atlantic by Thursday afternoon. A widespread area of showers and thunderstorms associated with this system will spread eastward from the Ohio Valley into the northern Mid-Atlantic. An area of heavier rainfall is expected to pool along the warm front as it lifts through the northern Mid-Atlantic region Thursday, which may lead to the potential for flash flooding. An additional area of excessive rains is possible in the higher terrain of West Virginia. Near the low pressure center itself, locally strong to severe thunderstorms may also be possible. The western edge of this system is forecast to lift slowly northward as a warm front the next few days with scattered showers and thunderstorms expected in the vicinity of the boundary across the central Plains and the middle Mississippi Valley. The most widespread and heaviest of the activity is expected along the front itself and WPC has highlighted a slight risk for flash flooding in this area for Thursday. An upper-level low moving into northern California will weaken as it moves into the Great Basin but should continue to allow for showers and thunderstorms to develop across parts of the intermountain West. These should remain confined mainly to areas of higher terrain and most widespread during peak daytime heating hours. Across the higher terrain of northern California and Nevada, isolated flash flooding may be a threat. Additionally, monsoonal moisture streaming into the four corners region will also keep showers and thunderstorms in the forecast across the southern and central Rockies. And finally, high pressure in the mid to upper levels of the atmosphere remains parked over the Pacific Northwest. This will keep the above normal temperatures in place through the end of the work week. Relief may be in sight by the weekend though as the ridge finally begins to break down allowing for temperatures to moderate closer to seasonal values. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php