Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 357 PM EST Mon Dec 28 2015 Valid 00Z Tue Dec 29 2015 - 00Z Thu Dec 31 2015 ...Major winter storm to impact the Middle Mississippi Valley/Great Lakes region into New England... ...Threat for flash flooding continues across sections of the Tennessee/Ohio Valleys and down toward the south-central U.S... ...Anomalous warmth remains in place east of the Mississippi River with cooler conditions to the west... The National Weather Service hazards map paints an active pattern from lower Plains eastward. This is all in response to a compact upper low currently lifting through the Ozarks. The western and northern edge of the precipitation shield continues to feature a mixture of snow, sleet, and freezing rain. Mild Gulf air overrunning the shallow axis of cold air has led to this complex array of precipitation types. Overall, such impacts are to stretch from the Middle/Upper Mississippi Valleys across the Great Lakes and into New England. The current forecast suggests 6 to 10 inches of snow are possible from southern Minnesota up across the northern half of Michigan into upper sections of New England. As mentioned, ice will be an issue with accumulations extending from lower Michigan into much of the northeastern U.S. 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. Highs on Tuesday should remain in the teens from Idaho eastward to the Upper Midwest which equates to readings about 10 to 15 degrees below normal. Meanwhile, across the east, the mild weather will continue through Wednesday, particularly from the mid-Atlantic southward. Forecast temperatures should be about 20 to 25 degrees above climatology over the Mid-Atlantic and Carolinas on Tuesday 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. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php