Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 356 PM EST Sat Dec 21 2013 Valid 00Z Sun Dec 22 2013 - 00Z Tue Dec 24 2013 ...Expansive storm system will continue to bring a large number of hazards from snow and ice to flooding to severe weather through the rest of the weekend to the central and eastern U.S.... ...Temperatures will feel like Spring for much of the East, while they remain well below average for the Central U.S... ...More rain/snow for the Pacific Northwest into the early part of next week... A large storm system in the center of the country will slowly spread eastward through the remainder of the weekend as two very different air masses collide. Several waves of low pressure will track northeastward along a frontal boundary currently separating temperatures in the 20s across Oklahoma from temperatures near 80 across Mississippi. The anomalous December warmth spreads all the way into New England where temperatures are well into the 50s this afternoon. Ongoing severe icing across Oklahoma to Missouri will transition toward light and moderate snow tonight as the ice threat shifts to southern lower Michigan and Northern New England. A broad 4 to 8 inches of snow is forecast from eastern Kansas into northern lower Michigan while 0.25 to 1.0 inches of freezing rain is possible for sections of northern New York eastward into New England. Far northern Maine is expected to remain all snow with this storm, likely picking up 6-12 inches by Monday evening. Flooding will be another major concern with this system, due in part to slow moving excessive rainfall rates more typical of April and May than December, and melting snow cover from portions of the Ohio Valley into the Northeast. Ongoing flooding near the middle Mississippi valley will spread northeastward tonight and into the Mid-Atlantic region on Sunday where 2-4 inches of rain is expected. A threat for tornadoes and strong to severe straight line winds will continue this evening and into the overnight hours from the lower Mississippi valley into the Ohio Valley, with the threat diminishing by early Sunday morning into the Southeast and Appalachians. Behind the storm system's associated cold front, temperatures will range from 10 to 30 degrees below average, with the greatest departures in the central and northern Plains. Out across the Northwest, mountain snow and lower elevation rain will pick back up again in intensity with the approach of a cold front Sunday night. Rain/Snow totals across the northwest should not be out of the ordinary for Winter, meaning a decent shot, but not too heavy nor light. Otto Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php