####018003209#### ACUS01 KWNS 271627 SWODY1 SPC AC 271625 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Sat Apr 27 2024 Valid 271630Z - 281200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS PORTIONS OF SOUTHERN KANSAS...MUCH OF OKLAHOMA...AND NORTHWEST TEXAS.... ...SUMMARY... Severe thunderstorms are likely today and tonight across the southern and central Plains into the lower to mid Missouri Valley. The most numerous/intense storms are expected from north Texas into Oklahoma and southeast Kansas, where strong tornadoes, very large hail of 2-3 inches in diameter and damaging winds of 60-80 mph are all possible. ...A regional outbreak of severe thunderstorms is forecast for this afternoon and evening across parts of KS/OK. Very large hail and strong tornadoes are possible.. ...OK/northwest TX/south-central KS... Water vapor imagery shows the main upper trough is still back over southern AZ, with a rapidly ejecting mid/upper level jet streak nosing into OK/TX. This lead feature has aided in the development of severe storms this morning over parts of west TX/OK. Storms will develop northeastward through the afternoon into central KS, despite an expansive anvil shield from the morning convection. These storms will pose a risk of very large hail and a few tornadoes through the afternoon and early evening. Farther south, the air mass across much of central/western OK and northwest TX continues to warm/destabilize as temperatures rise through the mid/upper 70s - eliminating CINH. Only weak upper forcing through the afternoon will result in chaotic development of discrete supercells in a very strongly sheared and very unstable environment. Forecast soundings show very steep mid-level lapse rates, ample low-level moisture, and strong/increasing shear profiles through the day. Details of timing and location are nebulous, but those storms that develop will pose a risk of very large hail and strong and possibly long-track tornadoes. The stronger large-scale forcing will arrive around/after dark, with a greater eastward surge of storms across central OK expected. This activity may organize upscale in bowing segments will an increasing risk of damaging winds along with hail and tornadoes into southeast KS and northeast OK tonight. ...Southeast CO into northern KS... A rather strong surface boundary extends from southeast CO across much of northern KS. Relatively strong heating along this boundary and moderate instability will lead to scattered thunderstorm development by mid-afternoon along the entire corridor. Steep mid-level lapse rates, strong deep-layer shear, and favorable low-level wind profiles in vicinity of the boundary will pose a risk of very large hail and a few tornadoes through the afternoon and early evening. This activity is expected to build eastward this evening along the same boundary into parts of southern IA/northern MO, with a continued risk of large hail along with an increasing threat of damaging winds. ..Hart/Jewell.. 04/27/2024 $$