Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 353 AM EDT Sun Apr 12 2015 Valid 12Z Sun Apr 12 2015 - 12Z Tue Apr 14 2015 ***Stormy weather pattern across the southern U.S.*** ***Cold front crossing the Plains and Ohio Valley*** ***More rain and snow showers returning to Pacific Northwest*** A well-developed shortwave trough tracking across the northern half of the country in the mid-levels of the atmosphere will result in the passage of a cold front from the northern High Plains and reaching the Great Lakes and Ohio Valley by Monday afternoon. Although the main surface low with this feature will be well to the north over central Canada, there will likely be a couple waves of low pressure that develop along this cold front. The most active weather pattern is expected to evolve over the southern Plains and the Deep South. The stationary front that has been situated along the Gulf Coast is progged to return northward as a warm front and advect copious amounts of moisture from the Gulf of Mexico for the beginning of the work week. This is a result of return flow from a departing surface high pressure area to the east and the approaching cold front to the west. There will likely be widespread 1 to 3 inch rainfall amounts by Tuesday morning in these areas, with locally higher amounts possible that could cause some flooding issues. Elsewhere across the continental U.S., cold weather by April standards is expected for much of the Rocky Mountain region and the Great Basin. The approach of the next cold front over the Pacific Northwest on Monday will bring scattered rain and mountain snow showers back into the forecast. Pleasant weather is expected for the Mid-Atlantic and Northeast U.S. through Monday as high pressure keeps that region mostly sunny and precipitation free. D. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php