SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon May 19 2025 Valid 191630Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS FAR NORTH TEXAS...MUCH OF CENTRAL AND EASTERN OKLAHOMA...SOUTHEAST KANSAS...AND THE OZARKS... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TENNESSEE INTO SOUTH CAROLINA... ...SUMMARY... Significant severe weather is likely from the central/southern Plains into the the Ozarks today into tonight. All severe weather hazards are expected, to include tornadoes (some potentially strong to intense), very large hail, and severe winds. A powerful upper trough over the southern Rockies will eject into the Plains today, with an associated 70-80 knot mid level jet nosing into OK. Meanwhile, the primary surface low will deepen over northwest OK and a southerly low-level jet will strengthen across the warm sector. The resulting synoptic pattern is very favorable for significant severe weather over portions of OK/AR/MO/KS, with the potential for strong tornadoes, very large hail, and widespread damaging winds. However, the mesoscale details of the forecast result in considerable uncertainty regarding the corridors of greatest risk. ...Eastern OK/Western AR/Southwest MO... A southern stream shortwave trough over TX will track northeastward today. Large scale ascent ahead of this feature will weaken the cap and likely lead to rather widespread convective development by early afternoon over much eastern OK and western AR. Forecast soundings in this area show a very unstable air mass and favorable low and deep layer shear profiles for supercell development. All severe hazards are possible, including strong tornadoes. Refer to MCD #874 for further details. ...North TX/Central OK/Eastern KS/southeast NE... Behind the aforementioned convective development, a pronounced dryline will become established from west-central OK into central KS. Strong heating along and west of the dryline, combined with dewpoints near 70f to the east, will result in extreme instability and only a weak cap. Large-scale mid-level height falls/forcing for ascent associated with the approaching upper trough over the southern Rockies will lead to discrete/intense supercell development by mid/late afternoon - potentially along the entire length from north TX into KS. These storms will pose a risk of very large hail and strong tornadoes through the early evening. Farther north in northeast KS and southeast NE, the Pacific cold front will impinge on the dryline, aiding convective development but perhaps leading to more linear forcing. Nevertheless, large hail and tornadoes will still be possible. ..Hart/Moore.. 05/19/2025