Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Apr 06 2023 04:19:35 ACUS02 KWNS 060419 SWODY2 SPC AC 060417 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1117 PM CDT Wed Apr 05 2023 Valid 071200Z - 081200Z ....NO SEVERE THUNDERSTORM AREAS FORECAST... ....SUMMARY... Areas of thunderstorm activity are possible across the Gulf Coast states, parts of the Colorado Rockies, and the interior Northwest Friday through Friday night, but the risk for severe storms appears negligible. ....Synopsis... While mid/upper flow across the northern mid-latitude Pacific gradually begins to amplify Friday through Friday night, models suggest that an amplified regime will also continue to evolve downstream, across Canada into the northern Atlantic. It appears that this will include a significant remnant perturbation emerging from confluent flow across the Great Lakes through Canadian Maritimes, and supporting strengthening cyclogenesis across the northwestern Atlantic, in the wake of an occluding preceding cyclone pivoting to its northeast and north. A cold front trailing the new cyclone is forecast to surge farther offshore of the northern and middle Atlantic Seaboard, while the center of an expansive cold surface high shifts across the upper into lower Great Lakes vicinity. A much less amplified regime will prevail in the southern mid- and subtropical latitudes, with broad mid-level troughing across the eastern Pacific transitioning to broad ridging across the Gulf of Mexico and Southeast into western Atlantic. One or two short wave perturbations are forecast to progress through this regime across the northern Mexican Plateau through Rio Grande Valley and northwestern through north central Gulf coast vicinity. .....Gulf Coast/Southeast... It appears that cool surface ridging to the southwest of the Great Lakes high will be maintained across the Ohio Valley through much of the middle/lower Mississippi Valley, the southern Great Plains and northwestern Gulf coast, while ridging also noses south-southwestward to the lee of the southern Appalachians through this period. At the same time, a weak return flow off the western Gulf of Mexico is forecast to maintain a relatively moist low-level environment across much of the Gulf Coast vicinity. Above the cool boundary-layer air, this moisture appears likely to contribute to conditionally unstable thermodynamic profiles supportive of widespread convection and embedded thunderstorms. Aided by forcing associated with the short wave perturbations, this may be ongoing early Friday across the Texas coastal plain into lower Mississippi Valley, before gradually spreading east-northeastward through Friday night. Additional thunderstorm development is possible ahead of the wedge cold front across parts of central Georgia Friday afternoon, but modest boundary-layer instability, weak low-level flow/shear and a tendency for convection to perhaps become undercut by the front seem likely to minimize the severe weather potential. A corridor of modest boundary-layer instability across southeastern Louisiana into far southern Mississippi may also support a couple of strong storms Friday afternoon. However, weak low-level forcing for ascent and shear seem likely to result in only brief/marginal severe weather potential, at best, and severe probabilities are being maintained at less than 5 percent. ....Western U.S... Pockets of cold air aloft associated with weak or weakening mid-level troughing may support weak destabilization and scattered thunderstorm activity across parts of the interior Northwest and Colorado Rockies Friday afternoon and evening. ...Kerr.. 04/06/2023 $$ = = = 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) .