Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 348 AM EDT Mon May 11 2020 Valid 12Z Mon May 11 2020 - 12Z Wed May 13 2020 ...Much colder than average temperatures to stick around through Tuesday for the central/eastern U.S., while warmth continues in the Great Basin... ...Rain and thunderstorms to develop across the Pacific Northwest/Northern California and the Southern/Central Plains Monday and Tuesday, South Florida also stays wet... ...Low pressure system may spark thunderstorms in New England today with a light wintry mix or snow on the backside... To start the week, much of the central and eastern U.S. will remain mired in a prolonged stretch of colder than average temperatures. Record cold minimum and maximum temperatures should be set from the Plains all the way to the Eastern Seaboard both Monday and Tuesday. Freeze Warnings and Frost Advisories are in effect across parts of the Midwest, with additional Freeze Warnings and Watches across the Appalachians into parts of the Northeast. Meanwhile in the West, warmer than average temperatures are expected to continue across the Great Basin and Four Corners regions. Warm and windy conditions are a recipe for fire weather concerns in the Southwest, resulting in the issuance of a Critical Risk by the Storm Prediction Center both Monday and Tuesday. Temperatures along the West Coast are forecast to trend cooler on Tuesday as a Pacific storm system advances inland on Tuesday. The upper-level low coming into the West will also lead to increasing chances for rainfall in the Pacific Northwest and northern California on Monday into Tuesday, with the heaviest rainfall amounts along the northern California and southern Oregon coast. Higher elevations of the Cascades, Sierra Nevada, and then into the Northern Rockies could see some light snow from this storm system. The Northern High Plains may also see a couple of rounds of wintry weather on the cold side of a front draped across the Intermountain West through Tuesday. As upper-level energy moves eastward, odds of spotty showers and thunderstorms will ramp up over the Central and Southern Plains Monday and Tuesday. Rainfall totals between 1-2 inches with locally higher amounts could lead to isolated areas of flash flooding. Additionally, portions of the Florida peninsula are expected to dry out after this evening's rain, but showers and thunderstorms will linger over South Florida through Tuesday with a couple of frontal systems nearby. Farther east, a low pressure system has its sights set on the Northeast today. Thunderstorms are forecast ahead of this low, some of which could be strong to severe in southern New England where a Marginal Risk has been posted by the Storm Prediction Center. Another round of light wintry mixed precipitation or snow is also possible for the Central Appalachians and parts of the interior Northeast behind the low. Drier conditions will take hold of the Northeast by Wednesday morning as high pressure centered over the Great Lakes begins to build in overhead. Mullinax Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php