Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Nov 09 2022 12:57:36 ACUS01 KWNS 091257 SWODY1 SPC AC 091256 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0656 AM CST Wed Nov 09 2022 Valid 091300Z - 101200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NEAR-COASTAL PARTS OF EAST-CENTRAL AND NORTHEASTERN FLORIDA... ....SUMMARY... A tornado threat is expected to develop this evening and persist tonight over parts of eastern Florida. Isolated damaging thunderstorm gusts may occur before dawn tomorrow in parts of the central Plains. ....Synopsis... In mid/upper levels, a large, complex cyclone -- currently centered near the NV/OR border -- is forecast to move northeastward across the north-central Rockies to eastern MT by 12Z tomorrow, as the trailing synoptic-scale trough assumes a more positive tilt. A strong, basal shortwave trough is expected to pivot northeastward from southern CA, with its 500-mb vorticity axis near a RAP-AIA-LIC-FMN line by 12Z. At the surface, 11Z analysis showed a low between HON-FSD, with slow-moving cold front across central/southwestern NE and northeastern CO, to near DEN. The initial low should move northeastward across central MN and weaken today. Approach of the intense mid/upper trough will foster cyclogenesis along the central High Plains segment of the front, which may retreat slightly northward over northeastern CO today before the newer, stronger low moves northeastward along the front overnight. By 12Z, this second, better-organized low should reach southwestern MN, with a much more progressive cold front extending southwestward over eastern NE, central/southwestern KS and northeastern NM. Meanwhile, what now is T.S. Nicole is forecast to proceed across the northern Bahamas today, and into central FL by the end of the period. See latest NHC advisories for tropical watch/warning info on Nicole, as well as track/intensity forecast guidance. ....Eastern FL Peninsula... Latest NHC track guidance shows the center of Nicole ashore in the PBI-VRB corridor tonight, then veering northwestward across central FL into early day-2. Once it reaches the Atlantic Coast, tornado potential will extend relatively far from center, given the large size of this system's favorable low-level wind field. A very moist airmass advecting off the Gulf Stream is expected, especially near and after landfall as near-surface flow veers from northeasterly to east and east-southeast, loses some cooler trajectories now evident north and northwest of center, and emanates from maximized upstream theta-e. Large hodographs below 2 km are expected near the coast -- accordingly pivoting clockwise around the western sector of hodograph origin with time, as the center moves inland. Associated effective SRH in the 200-400 J/kg range should become common, with locally higher values, and increasing surface-based buoyancy near the coast overnight. The greatest supercell/tornado threat prior to 12Z tomorrow should be in the middle-outer circulation sector north-northwest through east of center. Based on the latest NHC forecast track, this portion of Nicole's circulation will remain offshore through the day, then will begin impinging on the East Coast near the time of its central landfall tonight (given the north-northwest orientation of the coastline poleward of center). Because of Nicole's large size and expansive wind fields, much of coastal east-central and northeast FL could begin experiencing a tornado threat around the same time tonight, which will shift further northwestward/inland day-2/Thursday based on the NHC forecasts for track and wind radii. ....Central Plains... After 06Z, as the strengthening and accelerating cold front impinges on the northwest rim of a narrow warm/moist sector tonight, a thin band of scattered convection (including embedded thunderstorms) may develop along it. This activity should form initially over portions of central NE, backbuilding down the front across parts of northern and perhaps central KS before 12Z. Most forecast soundings suggest the buoyancy will begin as elevated -- rooted between 750-850 mb. However, a narrow tongue of surface-based effective lifted parcels is possible immediately ahead of the front, with dewpoints in the low 60s F as already observed in the area (and not expected to diminish). That, plus a shallow dry layer beneath the CAPE, and the presence of strengthening deep-layer winds, suggests a small but not negligible potential for a few gusts near severe limits to reach the surface. ...Edwards/Smith.. 11/09/2022 $$ = = = 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) .