Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 339 AM EST Mon Jan 26 2015 Valid 12Z Mon Jan 26 2015 - 12Z Wed Jan 28 2015 ...A major winter storm to affect the Northeastern U.S. on Monday/Tuesday... ...Very mild temperatures to continue over the central states... ...Wet weather expected across the Desert Southwest... At this point in time, a clipper system is weakening over the Ohio Valley and Central Appalachians which will eventually give way to a potent coastal storm. A general region of 2 to 4 inches of snow should spread over the much of the Mid-Atlantic region given the limited moisture and decaying nature of the initial system. However, as the upper trough digs across the Carolinas, it will attain a favorable orientation for rapid strengthening. By Monday evening and into the overnight hours, coastal cyclogenesis will commence east of the Delmarva with heavy precipitation spreading north and west of the low track. Unlike the system this past week which had limited access to cold air, a pronounced surface ridge to the north will supply sufficient subfreezing air to the Northeastern U.S. This will allow snow to be the dominant precipitation type with hefty totals expected given the anomalous slug of moisture hitting the New England coast. It appears many of the major metropolitan areas will be affected anywhere from Philadelphia through New York City and into Boston. The WPC winter weather desk expects anywhere from 18 to 24 inches of snow from southeastern New York all the way along coastal New England. An additional maxima is likely in the vicinity of eastern Massachusetts where 24 to 30 inches of snow is possible. Given the mesoscale nature of heavy snow bands, isolated areas of even higher amounts cannot be ruled out. As the surface low deepens rather markedly late Monday night, the pressure gradient will increase resulting in very windy conditions across the northeastern states. In particular, forecast wind gusts may easily reach the 40 to 70 mile per hour range resulting in near-zero visibility given the abundance of snow on the ground. This has resulted in blizzard warnings being issued from southeastern New York/northeastern New Jersey up the coastline to northeastern Maine. Very warm temperatures for late January to prevail over the Central U.S. Persistent downsloping flow in the lee of the Rockies will promote ample warmth over the Northern Rockies and into much of the Great Plains. Temperatures anomalies are expected to peak around the 25 to 30 degree above normal range. This would suggest highs into the low 70s over the Central Plains early this week. Elsewhere, a secondary clipper system will affect the Upper Great Lakes on Monday with only a few inches of snow expected given the weak nature of the feature. Out West, an upper low initially anchoring the subtropical East Pacific will lift northward spreading a broad axis of light to moderate rainfall. Snow levels will be rather high keeping wintry precipitation confined to the higher elevations of the Central Sierra Nevada range. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php