Subj : DAY1SVR: Enhanced Risk To : All From : Mike Powell Date : Thu Jul 27 2023 16:09:00 ACUS01 KWNS 271957 SWODY1 SPC AC 271955 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Thu Jul 27 2023 Valid 272000Z - 281200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF EASTERN MINNESOTA...WISCONSIN NORTHWOODS...WESTERN UPPER MICHIGAN... ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS WITHIN THE SOUTHERN NEW ENGLAND INTO THE MID-ATLANTIC... ....SUMMARY... Severe gusts and hail (some potentially significant) are possible the remainder of this afternoon and evening in parts of Minnesota and Wisconsin. Damaging to severe gusts also may occur today with thunderstorms in parts of the Mid-Atlantic/New England regions, and the central High Plains and Rockies. ....20Z Update... A few minor changes to wind probabilities from the Ohio Valley into the Northeast as well as modifications to the general thunder area based on the latest observational trends. The prior forecast reasoning otherwise remains valid. ...Wendt.. 07/27/2023 ..PREV DISCUSSION... /ISSUED 1112 AM CDT Thu Jul 27 2023/ ....Northeast... A well-defined shortwave trough is moving across central NY today. Forcing for ascent ahead of this trough will aid in the development of scattered thunderstorms by mid-afternoon from parts of PA and southeast NY into southern and eastern New England. Rich low-level moisture and pockets of strong daytime heating will yield MLCAPE values around 2000 J/kg. Rather strong wind fields will promote relatively fast-moving storms capable of wind damage. Parts of southern New England may also have sufficient low-level vertical shear to pose a risk of a tornado or two. Please refer to MCDs #1736 and #1737 for further details. ....Western Great Lakes/Upper Midwest... Fast zonal flow is present today across the northern Plains, with 50-70 knot westerly winds above 6km noted on forecast soundings. A surface boundary is sagging southward across MN, and should provide the focus for rapid thunderstorm development later this afternoon. A very unstable air mass will develop from central MN into northern WI, along with sufficient deep-layer shear for supercells capable of very large hail. Storms are expected to persist well into the evening as they spread eastward into parts of Upper MI and much of northern/central WI. The risk of rather widespread damaging winds will increase across this area. Given the favorable environment and consistent 12z model signals, have upgraded portions of this area to ENH. ....Rockies and High Plains... Similar to yesterday, scattered high-based showers and thunderstorms are expected to develop over the high terrain of CO northward into much of WY and MT. Fast westerly flow and steep low-level lapse rates will promote a risk of damaging wind gusts in some of these storms. As activity spreads eastward into the Plains, a few more robust updrafts may also produce large hail. $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .