Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 19 2023 07:17:11 ACUS03 KWNS 190717 SWODY3 SPC AC 190716 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0216 AM CDT Fri May 19 2023 Valid 211200Z - 221200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTH-CENTRAL OREGON INTO NORTHERN IDAHO... ....SUMMARY... Isolated severe thunderstorms are are possible from south-central Oregon into northern Idaho Sunday afternoon and evening. ....Synopsis and Discussion... Relatively modest upper flow is expected across the CONUS on Sunday, with ridging in place over the western CONUS and predominantly zonal flow across much central and eastern CONUS. The only exceptions to this weak flow will be from the Great Lakes into ME, which will be along the southern periphery of the troughing across eastern Canada, and over the Pacific Northwest late in the period as a shortwave trough moves through. This lack of more well-defined synoptic features will result in a lower predictability pattern, with the evolution of convectively induced vorticity maxima and residual outflow/surface fronts dictating the ares where storms are most likely. Based on recent guidance, a weakening front may extend from eastern NC southwestward through the eastern FL Panhandle early Sunday morning. Thunderstorms are possible in the vicinity of this front during the afternoon and evening. Modest shear and buoyancy is currently expected to limit the severe risk. Afternoon thunderstorms are also possible across the southern High Plains, as storms move eastward off the higher terrain. Modest low-level convergence amid a deeply mixed boundary layer could also result in more in-situ development over southeast CO and northeast NM. Overall storm coverage may be augmented by a convectively strengthened vorticity maximum moving within the larger scale upper ridging. Even so, storm coverage remains uncertain and weak shear will likely limit the strength of any storms that do develop. A few stronger storms are also possible during the afternoon and evening across the interior Pacific Northwest, ahead of the approaching shortwave. Moderate buoyancy and increasing mid-level flow may contribute to a few storms strong enough to produce hail and/or damaging gusts. ...Mosier.. 05/19/2023 $$ = = = 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) .