Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 337 AM EST Tue Dec 29 2015 Valid 12Z Tue Dec 29 2015 - 12Z Thu Dec 31 2015 ...Major winter storm to impact the Great Lakes region into New England... ...Threat for flash flooding continues across portions the Coastal Plains and southern Appalachians... ...Temperatures for northern tier of CONUS below normal for late December, well above normal for Mid-Atlantic and Southeast... Snow and heavy rain has ended over much of central states; however residual flooding and/or the threat for flooding will persist from Oklahoma to Illinois. Several rivers across the Midwest are out of their banks and impacting thousands of individuals. Several locations along the Mississippi River from St. Louis down to the delta are anticipating major flooding, possibly even breaking record flood levels. The low center of this system is currently lifting through the Iowa/Illinois area and will reach the Great Lakes region by this afternoon. The western and northern edge of the precipitation shield continues to feature a mixture of snow, sleet, and freezing rain as warm, moist air streams over a shallow layer of cold air. Precipitation will stretch from the Middle/Upper Mississippi Valleys across the Great Lakes and into New England. Accumulations of 6 to 10 inches of snow will be possible from southern Minnesota to upper sections of New England. Extreme northern Vermont, New Hampshire and western Maine could receive 12 to 18 inches. As mentioned, ice will be an issue with accumulations extending from Upper state New York into much of New England. Numerous Winter Storm Warnings and Advisories are in effect across the upper Midwest and the Northeast. Besides the wintry aspect of the system, there will continue to be the possibilities of heavy rainfall and severe weather. In the near term, the lower Ohio Valley and Tennessee Valley can expect periods of moderate/heavy rainfall capable of producing flash flooding. This should wind down as the cold front sweeps eastward toward the I-95 corridor. However, the primary upper dynamics will continue lifting toward the higher latitudes which should allow the frontal zone to stall from the central Gulf Coast up toward the lower Mid-Atlantic. This will spread additional heavy rains through mid-week to sections of Mississippi and Alabama which already experienced episodes of flash flooding late last week. Amplified flow over the nation will maintain rather healthy temperature anomalies the next couple of days. Broad upper troughing which continues to be replenished by upstream disturbances will favor below normal temperatures from the West Coast to the Great Plains. Temperatures today across the Northern Plains and Upper Midwest will average 10 to 15 degrees cooler than this typical for late December. Temperatures should be about 20 to 25 degrees above climatology over the Mid-Atlantic and Carolinas on today as highs soar into the low/mid 70s. A rather sharp north-south gradient is noted with regions under the influence of a sprawling ridge of high pressure expecting highs in the 30s and 40s over much of New England. Campbell/Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php