Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0258 PM CDT Wed Sep 11 2024

Valid 112000Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE GULF COAST...

...SUMMARY...
Hurricane Francine will pose a tornado threat through tonight across
the middle Gulf Coast region.

...20z Update...
The forecast remains on track with no changes needed to the current
D1 Outlook. Hurricane Francine continues to move northeastward, with
an increasing threat for tornadoes expected across southern
Louisiana shifting into southeastern Mississippi, southern Alabama,
and the Florida panhandle this evening. See previous discussion
below for more information.

..Thornton/Guyer.. 09/11/2024

.PREV DISCUSSION... /ISSUED 1127 AM CDT Wed Sep 11 2024/

...Gulf Coast - Hurricane Francine...
Hurricane Francine will continue to generally move northeastward
toward the southern Louisiana coast. Reference NHC for the latest
forecast track and intensity details. As Francine approaches the
coast later this afternoon into evening, a considerable
strengthening of east-southeasterly winds on its east-northeast
periphery will lead to an increasing near-shore/inland supercell
risk. This will be in tandem with a northward shift of a maritime
warm front and associated moisture-rich air, which will tend to stay
with about 50-75 miles within the Gulf Coast spanning southeast
Louisiana to the Florida Panhandle. The supercell/tornado risk is
expected to steadily increase this afternoon across southeast
Louisiana, transitioning northeastward toward southeast Mississippi,
southern Alabama and the Florida Panhandle into this evening and
overnight, with a few tornadoes possible regionally.

...Northern Rockies and northern High Plains...
High-based thunderstorms are expected to pose an isolated severe
risk late this afternoon into evening, with severe-caliber wind
gusts a possibility, along with some hail possible as well across
the northern Rockies including parts of Idaho and western Montana.
This is influenced by the lead portion of a Pacific Northwest
upper-level trough, with preceding height falls and the exit region
of the upper jet overspreading the northern Rockies and northern
High Plains through tonight.

Thunderstorms should increase in coverage/intensity by late
afternoon, especially from far southeast Oregon into southern Idaho,
southern Montana and northwest Wyoming. Around 250-750 J/kg MLCAPE
coincident with 25-35 kt of effective shear will support clusters
and bands of storms capable of hail and stronger wind gusts. 

Additional widely scattered storms are expected across the northern
High Plains within a modestly moist environment. Dry sub-cloud
layers will support the potential for stronger downdrafts and the
possibility of some severe-caliber wind gusts.