Subj : DAY2SVR: Nws Storm Predic To : All From : Mike Powell Date : Wed Nov 08 2023 09:51:00 ACUS02 KWNS 080629 SWODY2 SPC AC 080628 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1228 AM CST Wed Nov 08 2023 Valid 091200Z - 101200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Isolated thunderstorms are possible from central/southern Arkansas and northern Louisiana into south Texas and the Texas Coastal Plain on Thursday. ....Synopsis and Discussion... A southern-stream shortwave trough is forecast to extend from the central Rockies into southern CA early Thursday morning. Northern stream will likely feature a maturing mid-latitude cyclone over northern MN/far northwest Ontario, with a lead shortwave moving from southern Ontario through southern Quebec. Surface low associated with this shortwave will likely progress northeastward across the St. Lawrence Valley, just to the southeast of its parent shortwave. Expansive cold front attendant to this low will stretch back southwestward in the TX Hill Country early Thursday, with gradual southeastward/eastward progression of this front anticipated along the full length of the front throughout the day. Some shallow convection is possible across the Upper OH Valley early Thursday morning. A lightning flash or two is possible, but its limited depth should keep overall coverage below 10%. Farther south, a low-amplitude shortwave trough will likely progress northeastward across TX as the cold front gradually shifts southward. This is expected to lead to the development of a weak low which will gradually move eastward along the front as it moves across the TX Hill Country and Coastal Plain. Despite pre-frontal dewpoints in the mid/upper 60s, warm temperatures aloft and limited heating (due to abundant cloud cover) will keep buoyancy modest. As a result, warm sector thunderstorm development is unlikely. However, mid-level moistening and lift associated with the low-amplitude shortwave will likely support isolated elevated thunderstorms behind the front from south TX into the northern LA and central/southern AR. Highest storm coverage is anticipated of the Arklatex region. Another strong shortwave trough is expected to move across the Pacific Northwest, with the primary frontal band associated with this wave reaching the coast Thursday afternoon. Despite cold temperatures aloft, limited low-level moisture and mild surface temperatures will keep buoyancy very low. As such, convection within the frontal band is expected to remain too shallow for lightning. A few flashes are possible along the WA coast with the more cellular activity behind this band as large-scale ascent persists and mid-level temperatures continue to cool. ...Mosier.. 11/08/2023 $$ --- SBBSecho 3.14-Linux * Origin: Ilink: CCO - capitolcityonline.net (454:1/105) .