Severe Storm Outlook Narrative (AC)
Issued by NWS

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
372
ACUS02 KWNS 240514
SWODY2
SPC AC 240513

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1213 AM CDT Tue Sep 24 2024

Valid 251200Z - 261200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Severe thunderstorm potential is low on Wednesday.

...Synopsis...

An upper low within the base of the larger-scale upper trough
extending from the Great Lakes to the Lower MS Valley will become
cut-off from northern stream flow on Wednesday. As this occurs, the
northern shortwave trough will progress east across the Great Lakes
and southern Ontario. The developing upper cyclone over the
Mid-South/Lower MS Valley will not move much through the period.
However, moderately enhanced southerly deep-layer flow on the
eastern flank of the cut-off low will persist over the Southeast.
Meanwhile, latest forecast guidance and NHC forecasts show a
strengthening tropical cyclone emerging across the eastern Gulf of
Mexico. This system is forecast to remain well offshore from the
southwest FL coast through 12z Thursday.

...Southeast...

A stalled surface boundary/inverted trough will extend from near
coastal MS/AL northeast across the central Appalachians. Near and
east of this boundary, south/southeasterly low-level flow will
maintain a very moist airmass with dewpoints from the mid 60s to low
70s F. Potentially widespread convection may be ongoing Wednesday
morning across portions of this area, limiting destabilization.
Despite vertical shear that may otherwise support organized
convection, weak instability and poor lapse rates will limit severe
potential, though the strongest cells may produce locally gusty
winds.

Further south across the FL Peninsula, southeasterly low to midlevel
flow will increase, especially after 00z, as the developing tropical
cyclone emerges into the eastern Gulf. Forecast soundings show
enlarged, favorably curved low-level hodographs developing late in
the period. However, instability across the Peninsula is expected to
remain weak through early Thursday morning. At this time, tropical
cyclone related tornado potential appears limited through 12z
Thursday.

...Upper OH Valley/Lower Great Lakes vicinity...

A cold front will move east/southeast across the Lower Great Lakes
during the afternoon and into the overnight hours. Ahead of this
feature, a corridor of 60s F dewpoints will be in place. However,
surface heating is expected to be muted by cloud cover and showers.
As a result, instability will be weak and lapse rates will remain
poor, precluding severe thunderstorm potential.

..Leitman.. 09/24/2024

$$