Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Sun Aug 30 2020 Valid 311200Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS AND ARKANSAS RIVER VALLEY... ...SUMMARY... Thunderstorms associated with large hail and wind damage will be possible across parts of the southern Plains and Arkansas River Valley on Monday. Marginally severe wind gusts will be possible in parts of the Ozarks, central Gulf Coast states and Carolinas. ...Southern Plains/Arkansas River Valley/Ozarks... West-southwest mid-level flow will be in place across the south-central U.S. on Monday. At the surface, a cold front will advance southeastward into the central Plains and Ozarks. Ahead of the front, surface dewpoints in the upper 60s and lower 70s F will result in moderate instability developing across much of the moist sector by afternoon. Thunderstorms appear likely to form along parts of the front and in areas across the moist sector where pre-existing boundaries are present. NAM forecast soundings along and just south of the front from southern Oklahoma into central Arkansas at 00Z/Tuesday have MLCAPE in the 2000 to 3000 J/kg range and 0-6 km shear of 35 to 45 kt. This environment should support supercells with isolated large hail. Steep low-level lapse rates may also contribute to a wind-damage potential with supercells and short bowing line segments. At this time, the models are in much better agreement for Monday. The general consensus is that a broken band of strong thunderstorms will develop from parts of west Texas east-northeastward across the Red River Valley and into central Arkansas. The severe threat should be concentrated in the late afternoon and early evening, but a few persisting storm clusters could extend the threat into the mid to late evening. ...Central Gulf Coast States... Westerly mid-level flow will be in place across the Ohio and Tennessee Valleys on Monday. At the surface, a moist airmass will be located across much of the central Gulf Coast states where dewpoints will be in the upper 60s and lower 70s F. In response, moderate instability should develop across much of the region by afternoon. Although deep-layer shear will be on the weak side, low-level lapse rates will become steep in areas that heat up the most. Storms that develop in those areas will have potential for marginally severe gusts. ...Carolinas... A shortwave trough will move across the southern Appalachians on Monday as west-southwest mid-level flow remains in the Carolinas. A corridor of moderate instability is forecast to develop across the western and central Carolinas. Thunderstorms should develop in the higher terrain of the southern Appalachians and spread eastward across the instability corridor during the afternoon. Steep low-level lapse rates and moderate deep-layer shear should be sufficient for a marginal wind-damage threat during the mid to late afternoon. ..Broyles.. 08/30/2020Read more
from SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day2otlk_0600.html
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