Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Sep 21 2023 17:32:54 ACUS02 KWNS 211732 SWODY2 SPC AC 211731 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Thu Sep 21 2023 Valid 221200Z - 231200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTHERN NE AND SD AS WELL AS OVER THE COASTAL MID-ATLANTIC... ....SUMMARY... Severe thunderstorms will be possible across parts of the central and northern Plains, mainly Friday afternoon into Friday night. A few tornadoes are also possible along the Mid-Atlantic Coast early Saturday morning. ....Synopsis... A mid/upper cyclone will likely be centered near the OR/ID/NV border intersection early Friday morning, before then gradually shifting eastward throughout the day. This cyclone is forecast to be centered over eastern WY by early Saturday morning. Enhanced mid-level flow will accompany this cyclone, spreading across the Great Basin and into the central Plains as the cyclone progresses eastward. Surface lee troughing across the High Plains will likely deepen ahead of this system, and cyclogenesis along this troughing may lead to the development of a pair of surface lows, one over the central Plains and the other farther north across southeast MT. Elevated showers and thunderstorms will likely be ongoing at the beginning on the period from the Mid MO Valley into eastern OK and northeast TX. Evolution of these storms and their attendant cloud cover and outflow will influence the surface pattern across the Plains. General expectation is that the resulting combination of cloud cover and storm outflow will lead to a sharpening of the warm front across central and southern Plains. Strong heating is anticipated west of this warm front across the warm sector, but the warm temperatures aloft will likely keep most of OK and KS capped throughout during the afternoon and evening. The only exception is across southwest TX, where the combination of heating and low-level moisture could erode all the convective inhibition. A conditional risk for storms capable of strong gusts and large hail exists in this area. Higher thunderstorm chances are expected farther north across NE and SD during the evening and overnight. Much of this activity will likely be elevated, fostered by a strengthening low-level jet over the warm front and aided by increasing large-scale ascent attendant to the approaching cyclone. Environmental conditions support the potential for some stronger storms capable of large hail and a strong gust or two. There is a low-probability chance that development occurs close enough to the warm to support a surface-based (or at least near-surface-based) storm, with limited tornado potential. Additional development is possible early Saturday morning closer to the low, with some severe potential with this activity as well. ....Mid-Atlantic Coast... A developing tropical cyclone, recently deeded Potential Tropical Cyclone 16 by NHC, is forecast to track northeastward. Wind fields are expected to strengthening considerably, elongating hodographs over the Mid-Atlantic states. Highest tornado potential is anticipated closer to the center of this system, where the best low-level moisture and resulting instability will exist. Based on the current forecast, this appears it will occur over coastal NC around 06Z to 12Z. ...Mosier.. 09/21/2023 $$ = = = 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) .