Mesoscale Discussion 1416 NWS Storm Prediction Center Norman OK 1229 PM CDT Mon Jun 23 2025 Areas affected...parts of northeastern Iowa through central and northeastern Wisconsin Concerning...Severe potential...Watch possible Valid 231729Z - 232000Z Probability of Watch Issuance...60 percent SUMMARY...Gradually intensifying thunderstorm activity may pose increasing potential for a few strong downbursts through 3-5 PM CDT. DISCUSSION...Destabilization, within a pre-frontal boundary-layer characterized by seasonably high moisture content (including surface dew points in excess of 70F), is supporting a gradual increase in convective development, particularly within a small cluster near La Cross WI. This is occurring as insolation contributes to erosion of a relatively warm capping layer based around 700 mb, perhaps aided by forcing for ascent associated with one or two sub-synoptic mid/upper perturbations migrating around the northwestern periphery of the prominent mid-level high centered near the southern Appalachians. With continuing boundary-layer warming and weakening of inhibition, a further increase in thunderstorm development seems likely to gradually continue during the next few hours. Updraft inflow characterized by CAPE in excess of 2000 J/kg, in the presence of modestly sheared west-southwesterly deep-layer mean flow, weakening, but still in excess of 30 kt, may slowly contribute to increasing intensity and organization. Although the development of any appreciable convectively generated surface cold pool will probably be slow due the moist nature of the low-level levels, and modest lapse rates, precipitation loading in stronger convection may increasingly pose the risk for a few strong downbursts through 20-22Z. ..Kerr/Thompson.. 06/23/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MQT...GRB...MKX...DVN...ARX...DMX... LAT...LON 43519239 44889036 45658874 45018674 44138837 43379009 42459249 42699322 43519239 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
Category: Watches, Warnings, Advisories, & Hazards