Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jul 25 2024 17:24:59 ACUS02 KWNS 251724 SWODY2 SPC AC 251723 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1223 PM CDT Thu Jul 25 2024 Valid 261200Z - 271200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF EASTERN ND INTO NORTHWEST MN...PARTS OF WY INTO THE NORTHERN HIGH PLAINS...PARTS OF SOUTH-CENTRAL/SOUTHEAST AZ...NORTHEAST NV INTO NORTHWEST UT... ....SUMMARY... Isolated severe thunderstorms are possible across parts of eastern North Dakota and northwest Minnesota during the afternoon and evening. Isolated strong to severe storms will also be possible across parts of Wyoming into the northern High Plains, south-central and southeast Arizona, and northeast Nevada into northwest Utah. ....Synopsis... A mid/upper-level trough is forecast to move across the northern Rockies/High Plains and Canadian Prairies on Friday. Immediately ahead of this trough, one or more lower amplitude shortwave troughs may eject northeastward across the Dakotas. Continued deamplification of a persistent upper ridge over the Southwest is expected, as a shortwave trough moves inland over California and eventually into the Great Basin. Farther east, an upper trough will persist across parts of the southern Plains into the lower MS Valley, with another upper trough expected to shift slowly eastward across the Mid Atlantic and Northeast. ....Eastern ND into northwest MN... A relatively narrow corridor of moderate to strong destabilization (with MLCAPE increasing to near or above 2500 J/kg) is expected from eastern ND into northwest MN Friday afternoon, along/east of a cold front. While stronger large-scale ascent is expected to remain displaced north of the international border, isolated storm development will be possible during the late afternoon into the early evening. Effective shear of 30-40 kt will conditionally support some storm organization, and a supercell or two will be possible initially, with a threat of hail, localized damaging gusts, and possibly a tornado. A moderate low-level jet could support increasing storm coverage through the evening. While there may be a tendency for convection to become increasingly elevated with time, an isolated severe-storm threat could persist into Friday night. ....WY into parts of the northern High Plains... Some modest low-level moistening will be possible into parts of WY and western SD on Friday afternoon, though guidance varies regarding the magnitude and timing of this moisture return and related destabilization. There will be some potential for relatively high-based convection to develop during the afternoon and evening, potentially aided by any low-amplitude shortwaves ejecting northeastward ahead of the primary upper trough. One or more clusters capable of isolated severe gusts could move across parts of WY into western SD and adjacent portions of extreme southeast MT and northwest NE. ....Arizona... Strong thunderstorms will again be possible across parts of central/southern AZ on Friday. Steering flow may tend to be a bit weaker and more northerly compared to previous days, which would limit the southwestern extent of the severe threat. However, depending on the magnitude of destabilization in the wake of potentially extensive convection on D1/Thursday, isolated strong to severe outflow gusts will be possible during the afternoon closer to the Rim, and potentially into lower elevations during the evening. ....Northeast NV into western UT... High-based thunderstorm development is again expected across parts of NV into western UT Friday afternoon into the evening, in advance of the shortwave trough moving into CA. Moisture and instability are forecast to be weaker compared to D1/Thursday, but isolated strong to severe gusts will be possible with any deeper convection. A Marginal Risk has been added where confidence is currently greatest in storm coverage within a relatively favorable downburst environment. ...Dean.. 07/25/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .