Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Sun Aug 30 2020 Valid 301200Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN SD...CENTRAL/EASTERN NE...AND FAR NORTH-CENTRAL KS... ...SUMMARY... Strong to severe storms will be possible over parts of the Great Plains Sunday afternoon and evening, with damaging wind gusts and large hail the main threats. ...Northern/Central Plains... Shortwave trough currently moving into the northern Rockies is expected to continue eastward/southeastward throughout the day, reaching the northern Plains by late Sunday afternoon. A cold front will precede this shortwave, likely stretching from eastern ND south-southwestward to the southern KS/CO border. A well-defined elevated mixed layer will be in place, but strong heating and deep boundary-layer mixing is expected to result in an erosion of much of the convective inhibition ahead of the front by the late afternoon. Ascent along the front, augmented by large-scale forcing for ascent attendant to the approaching shortwave tough, will interact with this destabilizing air mass, resulting in convective initiation. The strength of the buoyancy suggests initial updrafts will be strong enough to produce hail, including the potential for a few instances of significant hail. However, these updrafts will also develop in the presence of notable mid-level dry air, and the resulting dry air entrainment is expected to impede overall updraft strength as well as promote the development of strong downdrafts. Additionally, the stronger shear will likely lag the surface front. These factors merit leaving out any significant hail areas with this outlook. Severe thunderstorms are still expected to during the late afternoon and evening along the front from central ND into central KS. Highest coverage of severe storms is currently expected to occur over eastern SD into central/eastern NE. ...Southern Plains into the TN Valley... Pair of ongoing mesoscale convective systems, one approaching the Red River border of TX and OK and the other moving into far northeast TX and southwest AR, will likely influence thunderstorm potential today along the remnant front extending from northwest TX into middle TN. Current trends suggest the remnants of western MCS will continue eastward through the Arklatex and Mid MS Valley. Thunderstorm development in the Arklatex appears less likely given the overturning that is occurring right now, with higher potential farther east into the mid MS Valley and adjacent TN Valley. The overall environment in this area will be moderately unstable and weakly sheared, supporting the possibility of a few storms capable of damaging wind gusts. Overall severe coverage is expected to be limited by the marginal environment. Farther west, isolated thunderstorms are possible amidst the deeply mixed environment over all the TX/OK Panhandles. Convergence along the surface trough/dryline combined with ascent from a convectively induced shortwave trough approaching the region could result in isolated convective initiation. As a result, a conditional severe risk for hail and/or strong wind gusts will exist late this afternoon through this evening. ..Mosier/Karstens.. 08/30/2020Read more
from SPC Forecast Products http://www.spc.noaa.gov/products/outlook/day1otlk_1200.html
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