Warmth is on the way for portions of the Midwest and Northeast currently clenched by the bitter grip of arctic cold. But the reprieve will come with a price. Heavy rain will sweep across the eastern half of the country Tuesday through early Thursday just as Gulf of Mexico warmth nips away at the cold. The warmth won’t stick around long though. Displaced but not disbanded, frigid air will immediately trail the rain. The cold will pour southeastward with haste as precipitation will not necessarily finish upon its arrival, prompting rain to transition to snow for much of the Midwest and inland portions of the Northeast.
The cross-country storm originated as low pressure in the northern Pacific Ocean that reached North America early Sunday morning. It spread heavy snow across the Pacific Northwest and the Rocky Mountains before emerging in the central Plains Monday as an intensifying snowstorm capable of bringing blizzard conditions to parts of eastern Colorado and northwestern Kansas.
The storm will spread heavy snow across the Plains and Upper Midwest between Monday night and Tuesday night as it becomes entangled by Gulf of Mexico moisture. Snowfall accumulations of 6-12″ are possible along a wide corridor extending from central Nebraska across northern Iowa, southern Minnesota and northern Wisconsin to Michigan’s Upper Peninsula. A separate swath of heavy snow will extend across the eastern Dakotas and northern Minnesota. The wide-reach of the heavy snow will likely snarl travel and commerce region-wide.
By Tuesday night warmth will be surging northward from the Gulf of Mexico throughout the Ohio and Mid-Mississippi River Valleys. Moisture will pour out of the Gulf and concentrate ahead of the low’s associated cold front. A long corridor of heavy rain will develop along an axis from southern Texas to lower Michigan and intensify as it sweeps eastward Wednesday and Thursday.
The surge of Gulf warmth will suppress the cold as far north as southern Maine by Wednesday afternoon as the storm creeps eastward. In parts of the Ohio Valley, northern Pennsylvania, Upstate New York and western New England, precipitation Wednesday may start as a mix of snow and freezing rain but the wintry precipitation is expected to quickly transition to heavy rain. The storm’s close proximity to the Gulf Wednesday will grant it open access to a direct subtropical moisture feed vigorous enough to overwhelm the deepest of cold layers. For coastal portions of the Mid-Atlantic and New England, including the busy I-95 corridor, the cold will not be as stubborn so precipitation is expected to begin as rain Wednesday evening.
The resurgence of warmth and moisture is expected to help the storm dump 1-2″ of rain nearly ubiquitously everywhere east of the Mississippi River between Wednesday and early Thursday afternoon. Additional rain is possible in the coastal Northeast, where heavy rain is likely to continue through the first half of Thursday as the storm reaches the Atlantic Ocean and undergoes rapid intensification.
All this rain will follow the coldest air of the season for much of the East. But since the Gulf warmth is only expected to suppress into southern Canada the early-week cold rather than eradicate it, the first of two consecutive cold shots will jump at the chance to invade as soon as the storm departs to the northeast.
For many areas between the Mississippi River and the Atlantic Ocean, midweek storm’s trailing cold shot will undercut the above-freezing temperatures before precipitation even has a chance to clear out. A swift transition to snow Wednesday evening into the overnight hours will be the result from southern Illinois to northern Maine. Only the Southeast and coastal Northeast will escape the changeover. Snowfall is generally expected to be light, but a blanket of 1-3″ from the mid-Mississippi River Valley to the interior Northeast will eradicate any evidence of the warm up before a much deeper polar plunge this weekend.
Snow chances will return by Saturday following the return of painfully cold temperatures that will bring the mercury into the single digits all the way to the Northeast coast. Two systems may bring snow to the Midwest and Northeast following this next arctic blast between Saturday and early next week. More about the snow will be discussed throughout the week as more specific details become clear.