Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 29 2025 06:12:52 ACUS01 KWNS 290612 SWODY1 SPC AC 290611 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN MONTANA ACROSS EASTERN WYOMING...NEBRASKA...AND INTO WESTERN IOWA... ....SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of damaging winds will be possible, with hail most likely over western areas. ....Much of NE into IA... A cold front is likely to extend from northeast Co into northern NE and IA during the afternoon, while low pressure develops over western KS. Winds aloft will be relatively weak at these latitudes, only averaging near 15-20 kt. Winds below 500 mb will also be relatively weak, except for within the deeply mixed boundary layer with gusty south winds. Indications are that thunderstorms will develop by late afternoon across eastern CO and western NE, with increasing coverage and vigor near the stalled front across NE and into northern IA. Models indicate numerous storms during the evening, with a general eastward propagation. Given such weak winds below 500 mb, it appears widespread and potentially shorter lived convection will be possible. However, an eventual aggregation into an MCS is expected, which could yield greater overall coverage of strong to severe gusts. Isolated significant gusts cannot be ruled out as storms move into the strongly heated air mass/deeply mixed boundary layer. ....MT into WY... High pressure will exist over southern Canada with northeast surface winds across much of the northern Plains. Dewpoints in the 50s to near 60 F will remain with in this air mass from eastern MT into WY, and daytime heating will yield MUCAPE over 2000 J/kg by afternoon. Cool temperatures aloft will exist in the mid and upper levels, along with 20-30 kt westerlies. Storms will form over the higher terrain during the late afternoon, aided by upslope flow. Given the backed low-level wind fields, sufficient shear will favor large hail, perhaps into the 1.75 to 2.00" range in the strongest cells. Locally damaging gusts will also be likely. ...Jewell/Squitieri.. 07/29/2025 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .