Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 331 PM EDT Fri Jul 03 2015 Valid 00Z Sat Jul 04 2015 - 00Z Mon Jul 06 2015 ...Slow moving frontal system will bring showers/thunderstorms to Appalachians/Middle Atlantic states... ...Scattered thundershowers across the Interior West with possible heavy storms in the Rockies as heat slowly eases... ...Significant cooling across the northern Rockies/Plains later with rain in the cool air over the weekend...with potential for severe thunderstorms ahead of the cold front over the Mississippi Valley especially on Monday... A weak area of low pressure will make its way eastward along a nearly stationary front that should begin to drop slowly southward as a cold front with showers and thunderstorms common across the northern tier of the Southeast across the Appalachians across the rest of the Southeast into the Mid Atlantic states before high pressure builds across the northern Mid Atlantic states on Sunday as the wave of low pressure moves offshore. Heaviest rains of 1 to 2 inches are expected from southern Arkansas across the southern border of Tennessee across the spine of the Appalachians into the Mid Atlantic states with heaviest amounts likely across the Upper South. A few severe thunderstorms are also possible. While heat advisories will continue across the holiday weekend across the Northwest, a sharp cold front is expected to drop south southeastward across the northern Rockies on Saturday night into Sunday with a cold rain developing across Montana and parts of North Dakota on Sunday into Sunday night. Much cooler temperatures will surge southward especially across Montana and western North Dakota on Sunday night into Monday with cooler air dropping southward as far as Colorado by Monday. Thunderstorms will develop ahead of the strong cold front but the best chance for severe weather is likely be on Monday ahead of the front across the Mississippi valley For the western U.S., diurnally driven showers and storms will continue to be present each afternoon and evening across the Four-Corners region and extending southward into Mexico in response to monsoonal moisture in place. Isolated thunderstorms are also possible across the higher elevations of northern California, Oregon, and Washington. Kocin Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php