Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 317 AM EDT Tue Oct 30 2018 Valid 12Z Tue Oct 30 2018 - 12Z Thu Nov 01 2018 ...Heavy snowfall likely for portions of the Southern Rockies... ...Widespread heavy to excessive rainfall possible from the Ohio Valley to the Gulf Coast with severe thunderstorms possible from east Texas to Louisiana on Wednesday... Showers and thunderstorms are expected to develop today along a strong frontal boundary from the Upper Midwest to the Central Plains, along with heavy snowfall across portions of the Colorado and northern New Mexico mountains. As much as 1 to 2 feet of snow is possible in the highest elevations, where winter weather advisories and winter storm watches are in effect. As the front continues advancing eastward the next few days, widespread showers and thunderstorms are likely along the boundary from the Great Lakes and the Ohio Valley southward to the western and central Gulf Coast. Heavy to excessive rainfall/flash flooding is possible with WPC highlighting a slight risk extending from portions of northeast Texas and the lower Mississippi Valley into portions of the Ohio Valley on Wednesday. Strong to severe thunderstorms will also be a threat, especially across parts of eastern Texas into the lower Mississippi Valley where SPC has a slight to enhanced risk for severe weather on Wednesday. This may hamper any outdoor Halloween related activities planned for Wednesday evening. Showers and storms will begin moving into the Northeast by Wednesday evening, with heavy rainfall continuing across the Tennessee Valley and Gulf Coast states into Thursday as well. The backside of this front features a much colder airmass, with afternoon highs by Thursday as much as 10 to 20 degrees below normal across portions of the central and southern Rockies into the Plains. Unsettled weather out west will continue to support scattered rain and higher elevation snow on Tuesday for parts of the Northwest and northern Rockies. Another round of potentially heavy precipitation arrives by Wednesday for the Pacific Northwest with organized rainfall likely to focus along the favored terrain of western Washington and Oregon. Warm and dry conditions will also persist across portions of California along with an elevated to critical fire weather threat. Red Flag warnings are in effect for parts of northern California. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php