Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 354 AM EDT Tue May 12 2020 Valid 12Z Tue May 12 2020 - 12Z Thu May 14 2020 ...Increasingly active weather pattern developing in the Plains and Midwest with rounds of severe weather and bouts of heavy rain... ...Temperatures to average 10 to 20 degrees below normal from the Mississippi River to the East Coast, cool Tuesday in the Plains gives way to warmer weather by Wednesday... ...Periods of rain in the Northwest, critical fire weather conditions in parts of the Southwest and southern High Plains... The weather pattern across the Lower 48 is showing signs of breaking down the stagnant "Warm West, Cool East" regime as the jet stream becomes more zonal from coast to coast. This means more upper-level disturbances tracking from western regions into the Heartland through mid-week. Today, showers and thunderstorms are forecast to develop over the Northern Rockies as a low pressure system tracks through the Intermountain West. Additionally, storms should fire in the South Central U.S. Tuesday evening. As the low tracks into the Plains on Wednesday, the dry line in the Southern Plains will spark thunderstorms that are likely to become severe. The Storm Prediction Center has Enhanced and Slight Risks issued for the Southern and Central Plains. Showers and storms are also possible in the Upper Mississippi Valley to the north of the low emerging into the Northern Plains. By Thursday morning, the storm system will traverse the Midwest where heavy showers and storms are possible, along with perhaps another round of severe weather in the Central and Southern Plains later in the day. Farther east, a dome of high pressure will have a strong grip over much of the eastern third of the country. Temperatures remain chilly for mid-May with more record cold minimum and maximum temperatures possible today from the Arkansas River Valley and the Upper Midwest to the Northeast. Freeze Warnings and Frost Advisories are also in effect for portions of these regions. Parts of the Plains begin to warm up by Wednesday but cooler temperatures stick around across the northeastern quarter of the CONUS. As a warm front lifts northward Thursday, temperatures will rebound to seasonally warmer levels throughout the Mid-South and Mid-Atlantic. In addition to the warmer temperatures, much of the East Coast can expect little in the way of precipitation thanks to the influence of high pressure overhead. While eastern regions begin to warm up and stay mostly dry, the West Coast and most notably the Northwest will witness cooler and wetter conditions through mid-week. This is due to an upper-level low off the Pacific Northwest coast that should stick around for a couple days. This pattern is a welcome sight providing beneficial rainfall to drought stricken areas of the Northwest. Speaking of "drought stricken", the dry conditions combined with hot and gusty conditions will make for increased fire weather concerns from southeastern Nevada and to Oklahoma and Texas Panhandles. Critical fire weather areas have been issued in these areas as well as the central Four Corners region. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php