Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0102 AM CDT Wed Jul 15 2020 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF CENTRAL/EASTERN MO...WESTERN/CENTRAL IL... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SOUTHERN/CENTRAL HIGH PLAINS... ...SUMMARY... Severe storms are most likely this afternoon and evening across parts of the mid Mississippi Valley, with damaging wind, large hail, and a couple of tornadoes possible. More isolated severe storms will be possible over portions of the southern and central High Plains, with large hail and damaging wind as the main hazards. ...Synopsis... A broad upper trough is expected to remain in place across the north-central CONUS today into tonight. Multiple embedded shortwave troughs will move eastward within the larger-scale trough, including a potentially vigorous MCV moving from the central Plains into the mid-MS Valley. At the surface, a weakening cold front will likely become nearly stationary across the southern Plains, while a surface wave associated with the MCV is forecast to move from the central Plains into the mid-MS Valley and Midwest by tonight. ...Mid-MS Valley and Vicinity... The severe potential across this region will largely be tied to the MCV moving out of the central Plains, and some uncertainty remains regarding the intensity and timing of this feature. Along and east of the MCV track, and south of an outflow-reinforced boundary likely to be somewhere across eastern MO into central IL, moderate to locally strong buoyancy (MLCAPE of 2000-3500 J/kg) is forecast to develop this afternoon, as strong heating occurs within a very moist environment. Intensification of any ongoing convection near the MCV track will be possible by early afternoon, with additional development to the south and east by late afternoon. Modestly enhanced midlevel flow attendant to the MCV will support effective shear of 30-40 kt, sufficient to support organized structures. Convection will likely evolve into one or more clusters, with corridors of damaging wind possible, especially where substantial boundary-layer warming/steepening of low-level lapse rates can occur. Some tornado risk may also evolve, either with any semi-discrete supercells early in the convective evolution, or associated with any cluster or QLCS that interacts with the effective surface boundary. ...Southern/Central High Plains... Easterly low-level flow and modest (but sufficient) deep-layer flow/shear will again support a threat of severe thunderstorms across portions of the southern/central High Plains this afternoon and evening. Initiation is expected by early afternoon across the higher terrain of central/southern CO into NM, with convection spreading into a larger portion of the High Plains by late afternoon/early evening. Steep midlevel lapse rates/moderate buoyancy, and effective shear of 25-40 kt, will support a large hail risk with the initial semi-discrete activity, in addition to a threat of locally severe wind gusts. One or more clusters may spread eastward by early evening, with a continued threat of locally severe wind gusts. Overnight, a cluster of storms with a lingering marginal wind/hail risk may persist into portions of western/northern OK and far southern KS, within a plume of strong elevated buoyancy. ..Dean/Lyons.. 07/15/2020Read more
from SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_1200.html
No comments:
Post a Comment