Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Aug 03 2024 05:02:06 ACUS02 KWNS 030502 SWODY2 SPC AC 030500 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Sat Aug 03 2024 Valid 041200Z - 051200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT ACROSS PARTS OF CENTRAL INTO NORTHEASTERN FLORIDA AND ADJACENT SOUTHEASTERN GEORGIA...SOUTHERN MINNESOTA AND ADJACENT PORTIONS OF EASTERN SOUTH DAKOTA...NORTHERN IOWA...AND SOUTHWESTERN WISCONSIN...SOUTH CENTRAL INTO SOUTHEASTERN MONTANA AND ADJACENT NORTHERN WYOMING... ....SUMMARY... Widely scattered strong thunderstorms may pose at least some risk for severe weather across parts of central into northeastern Florida and adjacent southeastern Georgia, portions of the upper Mississippi Valley and portions of the northern Rockies Sunday through Sunday night. ....Synopsis... Models indicate that mid-level flow across the northern mid-latitudes will remain amplified, with a notable mid-level high continuing to evolve over the Canadian Yukon Territory vicinity Sunday through Sunday night. Downstream, seasonably strong cyclonic flow likely will be maintained across the upper Great Lakes vicinity through St. Lawrence Valley, to the south of a prominent cyclone slowly migrating eastward across northern Quebec. In lower latitudes, a prominent high is forecast to remain centered across the Four Corners vicinity, while higher heights also begin to elongate eastward across the southern Rockies into the central Great Plains. Within modest westerly flow on the northern periphery of this feature, low-amplitude troughing may progress across and east-southeast of the northern Rockies into the Dakotas. Seasonably high moisture content (including a plume of precipitable water in excess of 2 inches) will remain largely confined to along and east of a weakening mid-level trough/shear axis, between the Western Ridging and ridging over the subtropical western Atlantic. While this is forecast to shift offshore of the northern Atlantic Seaboard, to the south of the Quebec cyclone, it likely will linger near the southern Mid Atlantic coast through the Florida Peninsula, and be reinforced by a surge of tropical moisture associated with a developing tropical cyclone emerging from the Caribbean. Beneath a lingering plume of warm-elevated mixed-layer air extending east-southeast of the northern Rockies, toward the upper Mississippi Valley, residual low-level moisture, enhanced by evapotranspiration, may contribute to a corridor of moderate to strong potential instability near a stalling surface frontal zone. ....Southeast... The risk for severe weather Sunday through Sunday night still appears largely conditional at the present time, due to the typical uncertainties accompanying a developing landfalling tropical system at this extended time frame. However, based on the current forecast track of what is expected to be a developing tropical storm, west-southwest of Tampa Bay early Sunday into the Big Bend vicinity by early Monday, much of central through northeastern Florida may be impacted by a period of enlarging clockwise-curved low-level hodographs, coincident with a tropically moist and unstable boundary-layer. This environment may become supportive of a risk for tornadoes. ....Northern Rockies... Model forecast soundings suggest that the boundary-layer may become very warm, deeply mixed and characterized by at least weak instability across much of southeastern into south central Montana by late Sunday afternoon, before an evolving cluster of thunderstorms begins to propagate east-southeast of the higher terrain. It appears that this convective development will be aided by forcing associated with the low-amplitude perturbation which may include a 30-40+ kt westerly mid-level speed maximum. Downward mixing of this momentum, coupled with the thermodynamic forcing, probably will contribute to a few strong to severe surface gusts, before the convection weakens Sunday evening. ....Northern Great Plains/Upper Mississippi Valley... Convective potential remains unclear due to model variability and uncertain forcing for thunderstorm development within the corridor of strong potential instability near the stalled frontal zone. However, models suggest that mid-level inhibition may become weaker across the upper Mississippi Valley portion of the surface front, relative to upstream across the northern Great Plains. Isolated thunderstorm development may not be out of the question during the peak late afternoon heating. Otherwise, forcing on the nose of a nocturnally strengthening and veering low-level jet might support thunderstorm development late Sunday evening and overnight. ...Kerr.. 08/03/2024 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .