Severe Storm Outlook Narrative (AC)
Issued by NWS
Issued by NWS
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088 ACUS01 KWNS 270558 SWODY1 SPC AC 270557 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1257 AM CDT Fri Sep 27 2024 Valid 271200Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE SC/NC COASTAL PLAIN... ...SUMMARY... Tornadoes will be most likely during the morning and remain possible into the afternoon across parts of the Carolinas and Virginia, in association with Tropical Cyclone Helene. ...Carolinas/Virginia... Helene is forecast by NHC to weaken into a tropical storm by the start of the forecast period. Continued weakening and eventual evolution into a post-tropical cyclone is forecast by later tonight, as the cyclone interacts with a mid/upper-level low over the Mid South and curls northwestward toward the Ohio Valley. The associated low-level wind field, coincident with a rich tropical moisture plume (with mid to upper 70s F dewpoints) in the eastern semicircle of the cyclone, will be strongest at the start of the period and substantially weaken during the afternoon. One or more bands of relatively low-topped supercells may be ongoing at the start of the period across parts of the Carolinas, immediately in advance of an increasingly pronounced midlevel dry slot. Low-level shear/SRH will remain quite strong in the morning, and the greatest relative tornado threat is still expected early in the period from the Pee Dee region of SC into the NC Coastal Plain. Convective bands will move northward into the afternoon, with some tornado potential spreading across parts of southern and central Virginia. Weakening low-level flow/shear and increasing influence of the midlevel dry slot should result in decreasing tornado potential by late afternoon into the evening. ..Dean/Barnes.. 09/27/2024 $$