ZCZC SPCSWOMCD ALL ACUS11 KWNS 310339 SPC MCD 310339 OHZ000-INZ000-MIZ000-310745- Mesoscale Discussion 0048 NWS Storm Prediction Center Norman OK 0939 PM CST Sat Jan 30 2021 Areas affected...central and northern IN...west-central and northwest OH Concerning...Winter mixed precipitation Valid 310339Z - 310745Z SUMMARY...Heavy snowfall rates will generally range 1 to 1.5 inches per hour and move from central IN northeastward into northern IN and northwest OH late this evening into the overnight. A gradual transition to mixed precipitation type is forecast across central IN and west-central OH. DISCUSSION...Radar mosaic shows a broad precipitation shield from IL eastward into OH. Strong low-level warm-air advection/isentropic lift and ascent associated with mid-level forcing attendant to the migratory shortwave trough, have resulted in moderate to heavy snowfall rates across central IN earlier this evening. The tropospheric column across much of northern IN has recently saturated with light to moderate snow being observed as of 1030pm EST. Snowfall rates are forecast to increase tonight across northern IN and northwest OH and peak in the 1 to 1.5 inches/hour range for a few hours before decreasing. Farther south, a nose of warm air around 850 mb was sampled on the 00 UTC Lincoln, IL raob --- indicative of a profile favoring mixed precipitation atop a sub-freezing layer near the surface. It appears this warm air around 850 mb will continue to shift east into parts of central IN and west-central OH tonight. Forecast soundings suggest a transition from snow to snow/sleet or freezing rain/rain will occur later tonight (12am-3am EST). It is uncertain how far north the transition to mixed precipitation type will occur (near a line from Lafayette-Marion-Celina), but areas farther south/southwest will be most likely transition to mixed precipitation type. ..Smith.. 01/31/2021 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...IWX...IND...LOT... LAT...LON 41898652 41908577 40968366 40348353 39798382 39528454 40108684 40578706 41658688 41898652 NNNN