ZCZC SPCSWOMCD ALL ACUS11 KWNS 021755 SPC MCD 021755 UTZ000-NVZ000-022030- Mesoscale Discussion 0183 NWS Storm Prediction Center Norman OK 1155 AM CST Sat Mar 02 2024 Areas affected...the Great Salt Lake Desert into Wasatch vicinity Concerning...Severe potential...Watch unlikely Valid 021755Z - 022030Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorm activity may overspread the region, including much of the Salt Lake City area, through 2-3 PM MST, accompanied by potentially damaging surface gusts, small hail, sharply reduced visibilities and a changeover of precipitation to at least a brief period of heavy snow. DISCUSSION...Forecast soundings indicate thermodynamic profiles with largely sub-freezing temperatures and/or wet-bulb temperatures across the Great Salt Lake Desert into Wasatch vicinity, except for initially a shallow near-surface layer over lower elevations. With insolation, a modestly deep and well-mixed boundary-layer appears to be evolving in advance of an approaching cold front, with sufficient moisture to support the development of weak boundary-layer based CAPE. With continuing insolation, further cooling aloft will support additional destabilization through mid afternoon. Deepening pre-frontal convective development, some of which has begun to produce lightning, is already underway upstream in response to the destabilization, aided by forcing for ascent ahead of mid-level troughing overspreading much of the Great Basin and Northwest. One northeastward progressing embedded short wave perturbation appears to passing near or to the northwest of the Great Salt Lake, with another trailing to its southwest. It appears that associated forcing for ascent may be accompanied by a developing cluster of convection with embedded thunderstorms overspreading the Great Salt Lake Desert into Wasatch vicinity through 20-22Z. Beneath the exit region of a vigorous upper jet streak, Rapid Refresh and NAM output indicate strong mean flow on the order of 45-50+ kt developing in the lowest few kilometers above ground-level, both ahead and to the rear of the convection. Coupled with latent cooling in convective downdrafts, aided by melting small hail or graupel, downward mixing of momentum may promote strong to severe gusts reaching the surface. This may also coincide with a precipitation changeover from rain and graupel to at least a brief period of heavy snow, contributing to sharply reduced visibilities as surface temperatures cool to near freezing. ..Kerr/Hart.. 03/02/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SLC...LKN... LAT...LON 40701408 41461309 41391244 40731205 39441349 39441442 39871463 40701408 NNNN