A Mesodiscussion is issued by the National Weather Service's Storm Prediction Center when there is a chance of a significant weather event impacting an area. These are routinely issued before weather watches or as updated to weather watches.
SPC MD 1394
MD 1394 CONCERNING SEVERE THUNDERSTORM WATCH 440... FOR NORTHERN ILLINOIS...NORTHERN INDIANA AND WEST-CENTRAL OHIO
Mesoscale Discussion 1394 NWS Storm Prediction Center Norman OK 1158 PM CDT Tue Jul 05 2022 Areas affected...Northern Illinois...Northern Indiana and West-central Ohio Concerning...Severe Thunderstorm Watch 440... Valid 060458Z - 060700Z The severe weather threat for Severe Thunderstorm Watch 440 continues. SUMMARY...An isolated severe threat will be possible across parts of northern Illinois and in west-central Ohio, over the next couple of hours. A marginal severe threat may also develop in parts of northern Indiana. Due to the marginal nature of the threat, WW 440 will allowed to expire at 05Z. DISCUSSION...Latest mosaic radar imagery shows a strong line segment in northern Illinois, with other thunderstorms ongoing from northern Indiana to central Ohio. The storms are located along the northern edge of a moderately unstable airmass, with the RAP showing MLCAPE across this area in the 1500 to 2500 J/kg range. The line of storms in northern Illinois will likely continue to move eastward, and be associated with a marginal wind-damage threat. Further to the east-southeast, the moderate instability combined with adequate deep-layer shear, may support an marginal wind-damage threat. The potential for strong wind gusts may be greatest across western and central Ohio, where surface-based thunderstorms are already ongoing. ..Broyles.. 07/06/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...IWX...IND...LOT...DVN... LAT...LON 41708600 42138846 42108915 41968959 41708976 41328949 40828737 40368589 39828457 39538362 39558298 39728282 40118279 40538314 41188454 41708600Read more
SPC Center Public Severe Weather Outlook (PWO)
Public Severe Weather OutlookPUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1137 AM CDT TUE JUL 05 2022 ...Severe thunderstorms expected over parts of the Mid-Missouri Valley and Upper Midwest this afternoon and evening... * LOCATIONS... Southeast South Dakota Southwest Minnesota Northwest Iowa * HAZARDS... Widespread damaging winds, some hurricane force Isolated large hail up to baseball size * SUMMARY... A derecho with embedded significant severe wind gusts appears probable from central to eastern South Dakota into southwest Minnesota and northern Iowa into this evening. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Grams.. 07/05/2022 $$Read more