Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 24 2024 05:13:26 ACUS01 KWNS 240513 SWODY1 SPC AC 240511 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1211 AM CDT Wed Jul 24 2024 Valid 241200Z - 251200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID MISSISSIPPI AND OHIO VALLEYS...MID ATLANTIC REGION...ARIZONA...AND THE NORTHWEST STATES.... ....SUMMARY... Isolated strong to severe thunderstorms may produce damaging gusts from parts of Iowa/Illinois into Pennsylvania/New York. Other locally strong storms are possible in parts of the Northwest, northern Rockies, Southwest, and Mid Atlantic regions. ....IA/IL/IN... Large-scale troughing will amplify on Wednesday as a shortwave trough over MN digs into the western Great Lakes. A surface cold front will sag into the Mid MS an OH Valleys by afternoon, with very warm and humid conditions expected to the south of the front. All 00z model solutions agree on the development of afternoon storms along/ahead of the front from southeast IA into central IL/IN. Moderately strong westerly flow aloft, steep lapse rates, and degree of CAPE suggest a threat of a few strong/severe storms capable of damaging winds and some hail. ....PA/NY... As the aforementioned front sags into western NY, slightly enhanced southwesterly low-level winds will strengthen warm advection and lift over parts of eastern NY/PA. This will likely lead to scattered thunderstorms through the afternoon. Forecast soundings show MLCAPE values over 1000 J/kg and sufficient deep-layer shear for a few organized storm clusters capable of locally gusty/damaging winds. ....NC/VA... Deep west-southwesterly winds will strengthen by this afternoon along a corridor from the southern Appalachians into the Mid-Atlantic states. This enhanced flow/shear profile will aid in helping to organize scattered diurnal thunderstorm development from western NC into parts of southern/eastern VA. Mid-level lapse rates will be poor, but strong heating and high PWAT values will promote a risk of a few intense storm clusters capable of gusty/damaging winds. ....AZ... The upper ridge over the western states will remain centered over parts of NV/UT today, with 15-25 knots of northeasterly mid-level flow across central/eastern AZ. Meanwhile at the surface, considerable moisture is expected to spread northward from Baja CA into the lower deserts overnight, with dewpoints around 60s expected tomorrow. Most 00z CAM guidance suggests multiple clusters of thunderstorms will form along the eastern rim and mountains of eastern AZ, with steering flow helping to spread the storms westward into the moist air mass Wednesday evening. This may lead to a more active convective day over central/southern AZ, with damaging wind gusts possible. Will maintain only MRGL risk at this time, but trends will be monitored for possible upgrade to SLGT in later updates. ....Northwest... Relatively fast cyclonic flow aloft will remain over the Pacific Northwest states into the northern Great Basin. Water vapor imagery shows ample mid-level moisture in place from northern CA into southern OR, which should spread eastward and aid in afternoon thunderstorm development from OR into parts of ID/MT. Forecast soundings show weak CAPE, but a few of the stronger cells could produce locally gusty/damaging winds. ...Hart/Halbert/Lyons.. 07/24/2024 $$ = = = 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) .