Severe Weather Outlook

show me my personal outlook →

Hayley here - Do you like lofi music and terrifyingly loud computer voices? Then stop by the 24/7 ish severe weather live stream!

Outlook for Wednesday, September 11

Outlook Summary

A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday into Wednesday night, in association with Tropical Cyclone Francine.

Outlook Images

overview

tornado 5%

wind 5%

hail 5%

Detailed Outlook

SPC AC 110547

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1247 AM CDT Wed Sep 11 2024

Valid 111200Z - 121200Z

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL GULF COAST

### SUMMARY

A few tornadoes are possible across the central Gulf Coast vicinity on Wednesday into Wednesday night, in association with Tropical Cyclone Francine.

Central Gulf Coast

Hurricane Francine is forecast to continue northeastward across the northwest Gulf of Mexico today, likely making landfall over the central LA Coast during the afternoon. Easterly/northeasterly winds are expected across much of the Southeast from the morning through the afternoon, which will likely keep the tropical airmass associated with this cyclone offshore (or only over immediate coastal portions of south-central and southeast LA). As the storm makes landfall, mid 70s dewpoints will spread northward into more of southeast LA, southern MS, southern AL, and the far western FL Panhandle during the evening. This increased low-level moisture could boast buoyancy enough for more sustained/persistent updrafts. Robust low to mid-level wind fields associated with the cyclone will support rotation within any more persistent updrafts, with some isolated low-topped supercells possible.

Current guidance suggests the highest tornado potential will exist from 21Z through 04Z from far southeast LA across southern MS/AL. Mid 70s dewpoints and southerly/southeasterly surface winds will persist from southern MS/AL into the far western FL Panhandle, supporting a low-probability tornado risk through early Thursday morning.

Parts of the Northwest/Northern Rockies

The strong shortwave trough currently off the Pacific Northwest coast is forecast to continue eastward throughout the period, while also deepening/maturing. By early Thursday morning, this shortwave trough will likely extend from the ID Chimney/northwest MT into the Great Basin. Strong mid-level flow will accompany this shortwave, spreading eastward from northern CA through the Great Basin as the wave progresses eastward.

Relatively cool mid-level temperatures are already in place from the northern Intermountain West into the northern Rockies, with 500 mb temperatures from -11.5 to -14 deg C sampled on the regional 00Z soundings. Strong heating and boundary-layer mixing beneath these cool mid-level temperature will result in modest buoyancy during the afternoon ahead of the shortwave trough. Afternoon thunderstorm development is anticipated as large-scale ascent increases amid this destabilized and modest buoyant airmass. The stronger flow and vertical shear will be displaced south of the region, but moderate shear combined with the cool temperatures aloft could still contribute to some isolated hail. High cloud bases and resultant strong outflow could result in some gusty winds as well.

Northern High Plains

Lee surface troughing will deepen throughout the day, with southeasterly surface winds increasing in response. Strong heating/mixing is anticipated across the region. Low-level moisture advection may help offset some of this mixing but dewpoints will likely still drop into the mid 40s to low 50s across much of the region. Highest dewpoints are anticipated across northeastern MT and western North Dakota. Even with this limited moisture, the strong heating should destabilize the airmass. Late afternoon thunderstorms are anticipated with this destabilized airmass as both increasing large-scale ascent and low-level convergence provide the lift needed for convective initiation. Vertical shear will likely be strong enough for some updraft organization (particularly across northwest MT), and high cloud bases will contribute to the potential for strong outflow capable of damaging gusts.

..Mosier/Lyons.. 09/11/2024

CLICK TO GET WUUS01 PTSDY1 PRODUCT

NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z

National Risk Overview

Wednesday, September 11: TORNADO: 5%; HAIL: 5%; WIND: 5%
Thursday, September 12: TORNADO: 5%; HAIL: 15%; WIND: 15%
Friday, September 13: ANY SEVERE: low / uncertain
Saturday, September 14: ANY SEVERE: low / uncertain
Sunday, September 15: ANY SEVERE: low / uncertain
Monday, September 16: ANY SEVERE: low / uncertain
Tuesday, September 17: ANY SEVERE: low / uncertain

Your Severe Outlook

Hey, it looks like your location wasn't detected.

Drag the marker on the map and we'll show you the severe weather potential for a given location.

Hi, I'm Hayley. Did you know that I run this site out of my own pocket? So if you'd like to help out and you're already planning on buying something off of Amazon, why not use our Amazon Severe Weather Outlook link before you buy and we'll get a tiny portion of your purchase.

Severe Weather Outlook Amazon link →

About Severe Weather Outlook . com

SWO started as a spinoff project of wickedwx, but has since replaced the site.