SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1116 AM CDT Sun May 18 2025 Valid 181630Z - 191200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHWEST AND CENTRAL KANSAS INTO FAR NORTHWEST OKLAHOMA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN MISSISSIPPI...CENTRAL ALABAMA...AND SOUTHERN GEORGIA... ...SUMMARY... Severe thunderstorms capable of all severe hazards are expected this afternoon and evening across portions of the central and southern Plains. Several strong to intense tornadoes are possible. ...KS/OK... A large upper trough continues to deepen over the western US, with a band of 60-70 knot southwesterly mid-level flow extending across NM into western KS/OK. The surface dryline will mix eastward into western KS and along the TX/OK border by mid-afternoon, with the air mass to the east becoming extremely unstable with dewpoints in the upper 60s and MLCAPE values over 4000 J/kg. Strong southerly/southeasterly low-level winds throughout the warm sector will provide a conditionally favorable environment for intense supercells capable of very large hail, damaging winds, and tornadoes. However, morning model guidance continues to show diverse solutions regarding coverage of convection later today. The area of greatest confidence in storm development and intensity will be near the warm front/dryline triple point over south-central KS. Discrete supercell development appears likely here, with forecast soundings showing favorable hodograph structures to promote a risk of strong tornadoes. The MDT risk has been extending slightly eastward along the warm front. Farther south along the dryline in western OK, confidence in initiation is lower. However, any storm that can form will be capable of all hazards. ...Western North TX... Another region of higher confidence in convective initiation will be over western north TX along the dryline. Hot surface temperatures in vicinity of a dryline bulge will aid in storm development. These storms will likely expand eastward and into southwest OK through the evening, with very large hail and damaging winds possible. ...MS/AL/GA... A narrow corridor of SLGT risk has been added for this afternoon from eastern MS across central AL and southern GA. Multiple MCSs are ongoing in this corridor, with associated outflow boundaries present. These boundaries may be the focus for further development this afternoon, with sufficient CAPE/shear combinations to pose a risk of damaging winds in the strongest cells. ..Hart/Moore.. 05/18/2025