159
ACUS01 KWNS 260101
SWODY1
SPC AC 260059

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 PM CDT Wed Sep 25 2024

Valid 260100Z - 261200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE
SOUTHERN APPALACHIANS INTO PARTS OF THE SOUTHEAST AND FLORIDA...

...SUMMARY...
Isolated strong to severe storms are possible this evening from the
southern Appalachians into parts of the Southeast. Some tornado
threat may develop later tonight over Florida, in association with
Hurricane Helene.

...Florida...
Hurricane Helene is forecast to intensify and move north to
north-northeastward across the southeast Gulf of Mexico tonight; see
NHC forecasts/advisories for more information. Helene`s large wind
field will continue to overspread the Florida Peninsula and Keys
tonight, with low-level shear/SRH becoming increasingly favorable
for low-topped supercells with a potential tornado threat.
Low-topped supercell potential prior to 12Z Thursday morning remains
uncertain, with inland instability expected to remain relatively
limited. Outer rain bands could begin to affect the western
Peninsula later tonight, while convection may persist near a
convergence zone near the east coast.

...Southern Appalachians vicinity into parts of the Southeast...
Widespread precipitation is ongoing this evening within a corridor
from the FL Panhandle into western NC/VA, but weak to locally
moderate buoyancy persists east of this band, with regional VWPs and
the 00Z RNK sounding depicting vertically veering wind profiles
favorable for organized convection. Generally weak low/midlevel
lapse rates will tend to limit storm intensity, but marginal
supercell potential may persist through the evening, with a threat
of isolated damaging gusts and possibly a tornado.

...Northern ID/northeast WA/northwest MT...
While low-level moisture is limited, steep lapse rates and ascent
attendant to an approaching mid/upper-level shortwave trough are
supporting a high-based storm cluster currently moving across the ID
Panhandle. This cluster has a history of 60-65 mph gusts, and will
move across northwest MT early this evening, with a continued threat
of strong to locally severe gusts.

..Dean.. 09/26/2024

$$