ZCZC SPCSWOMCD ALL ACUS11 KWNS 242204 SPC MCD 242204 WIZ000-MNZ000-250300- Mesoscale Discussion 0295 NWS Storm Prediction Center Norman OK 0504 PM CDT Sun Mar 24 2024 Areas affected...Parts of southeastern Minnesota and northern/central Wisconsin Concerning...Heavy snow Valid 242204Z - 250300Z SUMMARY...A snowband with eventual heavy rates near 1-1.5 inch/hour is expected to move northward across parts of southeastern Minnesota and northern/central Wisconsin into tonight. The onset of heavier rates is expected in the 23Z-04Z time frame. DISCUSSION...KARX radar data and mesoanalysis as of 22Z indicate a well-defined frontogenetic band moving northward across far northern IA, southern MN, and southwest WI. This band is generally located along the northern periphery of a swath of 40-50-kt 1-km flow per regional VWP data, which also shows a large clockwise-curved low-level hodograph -- indicative of strong low-level warm-air advection. The associated low-level warm nose is yielding melting of hydrometeors beneath the snowband (and a robust bright-banding signature), with light to moderate snowfall rates thus far. With time, the band will continue northward into a region of colder low-level air, and additional low-level cooling should be aided by nocturnal effects and wet-bulbing. As a result, snowfall rates should eventually increase to near 1-1.5 inch/hour as the snowband moves into the increasingly cold air. There is some uncertainty on how widespread these heavier rates will be (especially in the next couple of hours), due to the marginally cold temperatures and much of the frontogenetic ascent remaining below the dendritic growth zone. Nevertheless, the heavy-snow potential should increase in the 23Z-04Z time frame. ..Weinman.. 03/24/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GRB...DLH...ARX...MPX... LAT...LON 44059117 43959249 43979386 44239442 44649458 45019452 45409416 45709334 45959186 45928898 45698837 45288825 44718867 44218993 44059117 NNNN