Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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833 ACUS01 KWNS 050538 SWODY1 SPC AC 050537 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1237 AM CDT Sun May 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTH TEXAS... ...SUMMARY... Scattered strong to severe thunderstorms are possible across parts of South Texas today. A few strong, to locally severe, storms are also possible across the Mid-South and upper Ohio Valley. ...South TX to Mid-South... Southern Plains short-wave trough will progress into east TX by sunrise then eject across the Arklatex during the afternoon as a weakening 500mb speed max translates into the lower MS Valley. Low-level warm advection is not expected to be particularly strong ahead of this feature, but a modest LLJ will shift across the Arklatex into the middle TN Valley during the overnight hours. Early this morning, an expansive MCS has evolved ahead of the short wave over the southern Plains. This complex will propagate toward the lower Sabine River Valley then possibly weaken early in the period. Some airmass recovery is expected ahead of the MCS with modest heating expected from northern LA into northern MS by mid day. Of more concern is the trailing southwestern flank of the MCS across south-central TX. Early-day convection will likely extend across the TX Coastal Plain with more isolated activity farther west. However, convective outflow will sag south and serve as the focus for potential renewed robust convection later in the day. Surface temperatures should only warm through the 80s across deep south TX as east-southeasterly low-level flow will limit low-level lapse rates. However, the boundary may prove adequate for isolated supercells to develop within a sufficiently sheared environment for sustained rotating updrafts. Large hail and damaging winds would be the primary risk with the south TX activity. Isolated-scattered convection is expected to evolve across the Mid-South. While forecast lapse rates are poor, a few strong/severe storms could evolve ahead of the aforementioned short wave. Locally damaging winds and perhaps marginally severe hail are possible. ...Ohio Valley... Strong short-wave trough will advance across the upper Great Lakes into western QC by the end of the period. Southern influence of this feature will glance the upper OH Valley such that a few strong storms could evolve during the day. Surface front will be the primary focus for convective development, but forecast soundings show only modest surface-6km bulk shear, and do not exhibit particularly steep lapse rates (6-6.5 C/km). Gusty winds and marginally severe hail are the primary risks. ..Darrow/Flournoy.. 05/05/2024 $$