A significant winter storm will develop in the Southern Plains spreading a mix of rain, freezing rain, and heavy snow to portions of the Central Plains and Midwest Monday and Tuesday, eventually moving into the Mid Atlantic and the Northeast early next week. Heavy snow is likely to develop across Kansas and spread through Missouri, Iowa, and Illinois where places could see 8-12" of snow accumulation with isolated higher amounts. Snowfall rates of 1-2" an hour are possible which could cause reduced visibility in intense snow squalls. Freezing rain is also likely, with the greatest potential of freezing rain to stretch across parts of northern Missouri through central Illinois into Indiana and western Ohio. Freezing rain accumulations of a few hundredths of an inch likely with possible accumulations of a tenth of an inch. Freezing rain also possible across parts of the Appalachian Mountains in West Virginia, Virginia, and southern Pennsylvania. Severe thunderstorms to develop late today into tomorrow across parts of the south-central US and into the Lower Mississippi Valley. Hail and Damaging winds will be the primary threat.
A deep upper-level trough and a potent shortwave will move northeastward Monday while taking on a negative tilt across the Plains. Behind this mid and upper-level trough and shortwave, CAA and a pool of cold air will allow for snow across parts of the southwestern US to the Great Lakes region. This will combine with a strengthening jet streak and mid-level frontogenesis maxima will produce enhanced ascent across the region.
This system will likely produce two phases of wintry precipitation, freezing rain and sleet in the low-mid level warm advection ahead of the low, and heavy snow in the mid-level deformation/frontogenesis maxima in the cold sector as moisture wraps around the low due to isentropic ascent.
Today freezing rain will develop moving across central Kansas to northern Missouri, central/southeast Illinois, southern Indiana, and into Ohio Valley. Another swath of freezing rain will develop on Monday from northeast Kansas across northern Missouri to Iowa, central Illinois, central Indiana, and Ohio. Ice accumulations of a few hundredths of an inch to a tenth of an inch possible across this region with isolated higher amounts.
As the low deepens and moves eastward, guidance has good agreement
that a band of heavy snow will develop in the mid-level deformation zone in the cold sector. The combination of isentropic ascent into the dendritic growth zone combined with theta-e and moisture advection aloft will produce a saturated column with intensifying mesoscale ascent as it interacts with the shortwave and increasing frontogenesis band. Heavy snowfall is expected from southeast Nebraska across northeastern Kansas, far northwest Missouri, southern Iowa into northern Illinois.
Within this band, snowfall rates may peak at 2"/hr, with the enhanced ascent.
EPS probabilities for 6" peak near 95 percent in these areas, with maxima of 12" expected in parts of southeast Nebraska to southern Iowa.
Moving into Monday night into Tuesday, this system will move through the Ohio Valley and into the Mid-Atlantic/Northeast. Upper-level jet streaks are forecast to cross from the Ohio Valley across Pennsylvania and West Virginia, which will aid in transporting moisture into the region, and also produce forcing for ascent within this moistening column. Cold air damming along the Appalachian Mountains will trap cold air at the surface in the mountains of western Maryland and adjacent portions of West Virginia and northwest Pennsylvania /southwest Pennsylvania will be reinforced by precipitation. A mix of sleet and freezing rain is likely, especially in the terrain and elevated valleys of the Central Appalachians through the Laurel Highlands of Southwest Pennsylvania. WPC probabilities in this area are greater than 50% for 0.25" of freezing rain. Further to the north, cooler temperatures along with moisture transport and ascent will allow for some snowfall across the deformation zone across portions of central Pennsylvania and New York. WPC probabilities for 4 inches are moderate across central Pennsylvania and into southern New York.
Current NWS Hazards
72 Hour Snowfall Maps
72 Hour Hand Drawn Snowfall Map
Day 1 (Today)
Large hail and isolated wind damage will be possible this evening and tonight across parts of the southern Plains.
Day 2 (Monday)
A few strong to perhaps locally severe storms may linger into Monday from East Texas to the mid-Mississippi Valley.