SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0723 AM CDT Thu Oct 23 2025 Valid 231300Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHERN GREAT PLAINS... ...SUMMARY... Isolated severe storms are expected this afternoon into the overnight hours across the southern Great Plains. ...Southern Great Plains... Morning water-vapor imagery shows a mid- to upper-level low near the NV/UT/AZ border and model guidance shows this feature moving east into southern CO by late tonight. Southerly low-level flow is forecast to gradually increase through the evening and aid in moisture advecting northward from south-central TX (12.5 g/kg lowest 100-mb mean mixing ratio via the 12 UTC Del Rio, TX raob) into northwest TX and southern OK. Models continue to show only weak lee cyclogenesis, but the pronounced increase of a LLJ and associated low-level warm advection will aid in storm development and focus severe potential late this afternoon but especially into the evening/overnight. A southwest-northeast oriented boundary will extend from the TX South Plains into southwest OK by mid afternoon. The stronger heating and moisture increase will likely set up along and south of the boundary. The latest forecast soundings suggest supercells capable of a threat for large hail will be the primary risk from the TX South Plains northeast into southwest OK during the evening. Some enlargement of the hodograph and moistening low levels could yield an isolated risk for a tornado, in addition to localized severe gusts with the stronger storms. An increase in convective coverage is expected through the late evening as the LLJ and associated warm advection promote clustering and messy storm modes with time, coincident with a waning overall severe threat into the overnight. Farther west, diurnally-driven storms will likely develop in closer proximity to the mid-level cold pocket over the southern Rockies. An isolated risk for marginally severe hail/wind is possible with this activity before subsiding during the evening. ..Smith/Bentley.. 10/23/2025
