Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Feb 20 2023 00:37:02 ACUS01 KWNS 200036 SWODY1 SPC AC 200035 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0635 PM CST Sun Feb 19 2023 Valid 200100Z - 201200Z ....NO THUNDERSTORM AREAS FORECAST... ....SUMMARY... The risk for thunderstorms appears negligible across the U.S. through early Monday. ....Discussion... The primary branch of mid-latitude westerlies emanating from the Pacific continues to curve around the northern periphery of a prominent blocking mid-level high, across the northeastern Pacific into British Columbia and the Pacific Northwest. It then turns broadly cyclonic across the northern Rockies through the middle and northern Atlantic Seaboard, around the southern periphery of a broad, deep mid-level low still centered to the northern of Hudson Bay. At the same time, a prominent mid-level subtropical ridge is being maintained along a major axis extending from the southern Mexican Plateau through the Caribbean and Bahamas. While weak short wave perturbations progressing through the mid-latitude westerlies might contribute to some flattening of the mid-level ridging extending northward into the Gulf Coast states overnight, warm layers aloft are still expected to strongly cap weak to modest ongoing low-level moisture return across parts of the Texas coastal plain and Florida Peninsula. Upstream, although a significant short wave perturbation may begin to accelerate around the northern periphery of the blocking high, there appears likely to be little impact on positively tilted mid-level troughing trailing southwest of the southern California coast into the subtropical eastern Pacific, and largely cut off from the westerlies. An embedded mid/upper cyclonic circulation center has redeveloped northeastward along the trough axis toward the southern California/northern Baja California coast. However, it still appears that the colder mid-level temperatures and low-level moisture supportive of low-topped thunderstorm development will remain well offshore. Some lightning flashes were detected late this afternoon in convection forming across the higher terrain of northeastern Sonora, within the downstream plume of moisture return off the subtropical eastern Pacific. However, this has diminished with the loss of daytime heating. The potential for similar activity across the higher terrain of southeastern Arizona into southwestern New Mexico still appears low, but, based the 20/00z sounding from Tucson and latest radar trends, an isolated brief thunderstorm or two might not be entirely out of the question this evening. ...Kerr.. 02/20/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .