Area Forecast Discussion
Issued by NWS Northern Indiana
Issued by NWS Northern Indiana
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158 FXUS63 KIWX 121011 AFDIWX Area Forecast Discussion National Weather Service Northern Indiana 611 AM EDT Wed Jun 12 2024 .KEY MESSAGES... - Chances severe storms late Thursday & Thursday evening with strong gusty winds and large hail. - Hot & humid Sunday through Wednesday; highs around 90 to 95 with afternoon heat indices 95 to possibly as high as 105. - After Thursday, best chances for storms are Monday and Tuesday late afternoons and evenings. && .DISCUSSION... Issued at 255 AM EDT Wed Jun 12 2024 Day 2 of return flow around a large surface high will continue to allow temperatures to recover and reach well above normal by Thursday with afternoon temperatures approaching 90. Deeper, more significant moisture will be lacking and will help keep heat indices from climbing much above 90 degrees. The arrival of a weak cold front and associated upper level disturbance and upper level jet support will bring a fairly good potential for severe thunderstorms late Thursday into Thursday. In addition to these parameters, the edge of a robust EML will reach northern Indiana. Some capping with this EML will likely delay storm development. At this point, believe the best chances for storms are basically 20Z to 04Z (4pm EDT to midnight), but best chances appear to be in a smaller 7pm to 11pm window. SPC has upgraded the marginal risk to a slight risk over about the northwest half of the forecast area where the best chances for storms will reside. Otherwise, hot conditions will develop Sunday and very likely persist into at least Wednesday. A low level moisture intrusion will be delayed until Monday. Raised model blend dew points about 2F bringing given this intrusion bringing heat indices close to 100 during Monday and Tuesday afternoon. Given high confidence in this scenario, will continue to message the heat & humidity in the Hazardous Weather Product and social media. Substantial precipitable water values of generally 1.8 to 2.1" with high CAPEs will support chances for stronger storms with heavy rainfall. Activity should be highly diurnal with the best chances for storms during late afternoons and evening hours. && .AVIATION /12Z TAFS THROUGH 12Z THURSDAY/... Issued at 610 AM EDT Wed Jun 12 2024 Ridging moving eastward out of the area with zonal flow aloft into the region with southerly winds at the surface with a few gusts around 15 knots possible through 00z Thur. Otherwise, VFR conditions will prevail through the forecast period. && .IWX WATCHES/WARNINGS/ADVISORIES... IN...None. OH...None. MI...None. MARINE...None. && $$ DISCUSSION...Skipper AVIATION...Andersen