Mesoscale Discussion 1885 NWS Storm Prediction Center Norman OK 0147 PM CDT Mon Aug 12 2024 Areas affected...southern portions of the southern Great Salt Lake Desert into Greater Salt Lake City vicinity Concerning...Severe potential...Watch unlikely Valid 121847Z - 122045Z Probability of Watch Issuance...5 percent SUMMARY...Thunderstorm development may continue to increase, with some consolidation possible, across southern portions of the Great Lake Lake Desert into southern Salt Lake City vicinity through 3-4 PM MDT. This activity may be accompanied by small hail and a few strong to severe surface gusts. DISCUSSION...A moist boundary layer, including surface dew points in the mid 50s F, has become moderately unstable with CAPE increasing in excess of 1000 J/kg with daytime heating. This has already supported the initiation of a number of thunderstorms, perhaps aided by forcing for ascent associated with a weak short wave impulse, preceding a notable mid-level trough progressing inland across northern and central California through late afternoon. Daytime heating has already contributed to a mixed boundary layer characterized by temperature/dew point spreads up to around 30 F, but this may not increase much further, as convection becomes increasingly widespread through 21-22Z. Despite the somewhat modest depth of the boundary layer, shear beneath 30-50 kt west-southwesterly flow in the 500-300 mb layer may contribute to small to perhaps marginally severe hail in stronger storms. And melting/sub-cloud evaporative cooling might still contribute to outflow with strong to locally severe surface gusts reaching the surface, aided by modest east-northeasterly storm motions within 25-30 kt cloud-bearing layer mean flow. ..Kerr/Mosier.. 08/12/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SLC...LKN... LAT...LON 40211407 41041198 40241180 39791231 39141442 40211407
Storm Prediction Center Mesoscale Discussion 1885
12
Aug