Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Oct 29 2023 04:39:36 ACUS02 KWNS 290439 SWODY2 SPC AC 290437 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1137 PM CDT Sat Oct 28 2023 Valid 301200Z - 311200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... The risk for thunderstorms appears negligible across much of the U.S., Monday through Monday night. ....Discussion... Although mid/upper ridging near the North American Pacific coast may undergo some weakening, models indicate that it will maintain considerable amplitude through this period. As it does, it appears that a vigorous downstream short wave trough of Arctic origins will continue to dig southeastward across the central Canadian/U.S. border area through the mid Missouri/upper Mississippi Valleys by late Monday night. This is forecast to maintain positively tilted larger-scale troughing across much of the interior of the U.S., in the wake of a preceding impulse accelerating into and through an increasingly confluent regime across the St. Lawrence Valley into Canadian Maritimes. Downstream of the lead impulse, an initially modest surface wave, along a sharp frontal zone across the northern Mid Atlantic into southern New England at 12Z Monday, is forecast to rapidly migrate offshore into the northwestern Atlantic and deepen. The trailing cold front may nose southward to the lee of the Blue Ridge, through much of the southern Mid Atlantic by late Monday night, and a bit slower through the eastern Gulf Coast states and offshore of the northwestern Gulf coast, as the mid-level cold core lags across the Upper Great Lakes region into central Great Plains. The shallow leading edge of the cold air will continue to undercut a lingering modestly moist southerly return flow across the northwestern Gulf coast through southern Mid Atlantic vicinity, which could provide support for weak elevated instability and areas of convective development along the lower/mid-tropospheric baroclinic zone. However, forecast sounding suggest that relatively warm layers/weak lapse rates farther aloft will tend to minimize the risk for more than very isolated/sporadic lightning flashes. ....Upper Great Lakes... In the wake of the lead short wave impulse, cold mid-level air (including at or below -20C around 700 mb) is forecast to linger across the region Monday through Monday night. It appears that steep lapse rates beneath this regime across Lake Superior into northern Lake Huron may remain or become supportive of low-topped convection with occasional lightning, some of which could impact Upper Michigan coastal areas. ...Kerr.. 10/29/2023 $$ = = = 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) .