Here is the current surface setup this morning. We currently have a weak area of low pressure centered over Central Texas around the Dallas metro area with a warm front extending across the northern Gulf Coastal plain and Black Belt areas. The movement of this warm front will be vital in just how unstable portions of the deep south get on this afternoon and Saturday when it comes to the potential for severe weather. A rather deep upper trough to the east will keep cool advection coming in pretty strong to the north of the warm front, but a deepening wave to the west should turn winds more southerly and at least get the surface features moving northward somewhat in response. These are all questions that will become resolved in the next 24 hours.
The day 2 convective outlook from the SPC highlights a good chunk of Alabama in a SLGT risk (standard risk) of severe storms for Saturday afternoon and into the overnight.
A 30% risk area has been defined from areas encircled from a Monroe, LA – Dothan, AL – Tuscaloosa, AL – Jackson, MS region. This area is expected to see the most unstable air mass during this period and will likely be in the uncontaminated warm sector for a decent period of time. Thus, diabatic heating could allow temperatures to soar into the mid 70’s to lower 80’s. This will need to be monitored for a possible upgrade to moderate risk if these factors do indeed come together.
At this time, we look for scattered cellular development to take place across Mississippi and Alabama tomorrow afternoon with the threat of hail, high winds, and a tornado or two. The hail threat could be rather significant. Then, the instability axis is forecast to spread northward toward the Tennessee Valley ahead of the cold front and allow for a strengthening line of severe storms to push through much of Central Alabama. We will continue to keep you alert of changes with the situation through early tomorrow. Stay tuned as we will likely have teams in the field for this potential high impact weather event.
A winter weather advisory has been placed for Jackson and Dekalb counties of northeast Alabama through noon on Saturday as decent snowfall is dropping south and eastward out of Tennessee and Kentucky. We actually expect a good chunk of north and central Alabama to see snowfall from this system, but most of the potential for accumulations of near 1” will be over the mountain terrain of northeast Alabama. We will monitor the progression of the snowfall and keep you updated if things change over the next several hours.
We are watching tonight for a quick hitting snow event that should take place in the very early morning hours. The models are showing some snow, with very little if any accumulation but we are monitoring precipitation trends just in case since an arctic airmass is making its way southward along the front. Short range ensemble forecast maximum snowfall depth has upwards of 2″ from Auburn through Columbus in the early morning hours on the latest run. I don’t really buy into that becuase the low level temperature profile should be too warm to support it, but given that it’s shown we will mention the potential.
Here is another view of the composite refectivity from the WRF-ARW. This is a high resolution model at 4km. It has a decent snow band setting up over east Alabama from near Sylacauga north and eastward through the Atlanta metro area by 5am Saturday morning. This is something htat is quite possible, but as you can see the surface temperatures should be just above freezing which should allow for little to no accumulation.
We will watch things as the progress throughout the evening hours, but this doesn’t look major. What could be major for areas just to our west is what is coming down the road. We will get into that later on in much detail. For now, enjoy the snow showers folks in east AL.
Wow…what a day. LSM affiliate John Sibley captured the most intense footage of the day with tornadic activity near the Hattiesburg, MS metro area with a long tracked supercell that ravaged much of the area.
What a catch by our affiliate on his live stream today. We have video available for licensing if you are media. Contact brett@livestormsnow.com for information regarding licensing the high quality product that is degraded in the Youtube videos above.
John is scheduled to appear on several local affiliates in the morning along with The Weather Channel, ABC News, and Good Morning America. We will post updates as available along with more damage video and imagery.
Forecast, Severe Thunderstorms | Brett Adair | 
March 22, 2013 6:04 am | 
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