Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0630 AM CST Sun Mar 01 2026 Valid 011300Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTH FLORIDA AND OKLAHOMA... ...SUMMARY... Isolated severe thunderstorms capable of producing occasional large hail and damaging winds may occur this afternoon and evening across parts of south Florida and Oklahoma. ...South Florida... Recent water vapor satellite imagery shows a weak/low-amplitude mid-level shortwave trough over the northeast Gulf. This feature will track east-southeastward today over the FL Peninsula. Modest ascent associated with the shortwave trough should aid in isolated to widely scattered thunderstorms developing this afternoon across parts of south FL in the vicinity of a decaying front, and along the Atlantic Coast sea breeze. Around 1000-1500 J/kg of MLCAPE may develop across this region by peak afternoon heating, with seasonably cool mid-level temperatures present (around -12 to -13C at 500 mb). While low-level winds are expected to remain weak, some enhancement to the west-northwesterly mid-level flow attendant to the approaching shortwave trough should provide marginal deep-layer shear to foster modest thunderstorm organization. Consensus of recent high-resolution guidance suggests that at least isolated thunderstorms may form by 18-22Z south of the front and along various sea breezes while posing some threat for severe hail and occasional damaging winds. Have therefore included a Marginal Risk for parts of south FL with this update. ...Oklahoma... With large-scale upper troughing persisting over the eastern CONUS today, a weak shortwave trough will advance east-southeastward from the central High Plains this morning towards OK by early evening. A surface cold front is progged to decelerate and eventually stall along the I-40 corridor in OK, with modest boundary layer moisture present to its south. A narrow corridor of around 500-1000 J/kg of MUCAPE should develop by late afternoon/early evening along/near the front, aided by daytime heating and modestly steepened mid-level lapse rates. There is still a fair amount of uncertainty regarding convective initiation and overall thunderstorm coverage later today across OK, mainly owing to only weak large-scale ascent attendant to the low-amplitude shortwave trough and somewhat modest low-level moisture. Even so, the presence of elongated/nearly straight hodographs at mid/upper levels and related strong deep-layer shear suggest some potential for large hail and locally damaging winds if any robust updrafts can form and be sustained near the front late this afternoon and continuing into the evening. A focused Marginal Risk has been introduced this update where the best chance for isolated/sustained convection is apparent. ...Northern California... Large-scale ascent will overspread northern CA and vicinity ahead of an upper low that will approach the CA Coast by this evening. Gradually cooling mid-level temperatures and filtered diurnal heating of a modestly moist low-level airmass should support the development of weak instability across this region through the afternoon and evening. Isolated thunderstorms should develop, with the more robust updrafts possibly capable of producing small hail and gusty winds. This activity is expected to remain below severe levels owing to the weak instability forecast. ..Gleason/Bentley.. 03/01/2026Read more