Severe Weather : Georgia / Alabama #Derecho Event March 18 2013

Widespread wind damage reports were reported across much of Georgia and Alabama on March 18 2013. There were also reports of Hail varying in size from small to upward of 3 inches.

While this storm system as far as I’ve seen has not been classified as a Derecho, it does qualify as one. A Derecho is classified as a long lived line of storms causing wind damage for more than 240 miles along most of it’s length. Another requirement to meet Derecho qualification is wind speeds of or greater than 57 MPH at points along the path of the storm. I don’t have data to back this up, but from following and reporting on many of the storms spawned by this system, I’d say this qualification was also met.

This system caused widespread wind damage from North Alabama where it began to take on the characteristics of a Derecho and lasting into Southeast Georgia. The distance covered is almost double the 240 mile requirement.

Here’s a Radar loop of the event …

Here’s a couple maps showing wind damage and hail as well as a couple tornado reports.

Severe weather still on track for Georgia and Alabama Wednesday JAN 30 #gawx #alwx

This was written for my local area and posted on my Facebook page Cataula Georgia Weather. The local area is Columbus and Fort Benning Georgia and Phenix City Alabama. You can use this information for areas anywhere in East Alabama and West Georgia as the system coming through will cover a large area. On with the show….

The exact time is still in question depending on which model you go by and I will continue to look at them for agreement. Still looking like instabilities will increase sometime after 8:00 AM EST Wednesday morning. Regardless of timing, before the main area comes through we may see some thunderstorms in the area some which could be severe with damaging winds, lightning, and heavy rain.

The winds will be gusty during this time 20 to 25 mph and will increase as the expected line of stronger storms gets closer and moves through the area to about 40 mph. Gusty winds like this can cause damage without being associated with severe storms. Stronger winds are likely in any severe storm. I’ll also keep a watch for any discrete / individual storm cells developing out in front of the main line. These may become strong enough to bring severe weather to the area before the main line. These type of individual storm cells may also be capable of spawning tornadoes. The greatest threat at this time remains unchanged from my previous posts .. Strong to severe ‘damaging winds’ are likely and the possibility of a tornado or two. As always, ‘not everyone will see severe storms and or tornadoes’.

I’ll be looking at this closely over the coming hours for any changes that may increase the severity of the storms. Right now I do have one concern. As the trough approaches that will be bring the storms to the area, it looks to go from a positive tilt to a neutral tilt. This will increase the wind speeds / shear in both the upper and lower levels. At this time the winds are more than adequate for a damaging wind event and a couple tornadoes. Any increase would make this a larger threat. If the trough should go negatively tilted, the wind and shear would again increase even more. This is something that will need to be monitored and I will be doing just that. I’ll have another update Wednesday Morning or sooner is needed. ~ ED

As always, find me on Facebook https://www.facebook.com/CataulaGeorgiaWeather and Twitter Follow @Cataulagawx
before and when the storms strike. I’m there all the time and don’t always have time to update the blog here 😉

Christmas Severe Weather Event in the Southeast – December 25 2012

Regardless of strength and track of the developing low, at a minimum this will be a ‘damaging wind event’. On the extreme side it looks like there will be more than a couple tornadoes to deal with mainly in Central and Southern areas of Mississippi, Alabama, Georgia and possibly extreme Northern Florida.

If you’ve followed me long enough you know I won’t / don’t sugar coat what I see. I want you to enjoy your Christmas but I want you to be aware of the storms that will develop during the day Tuesday in Mississippi and Alabama continuing east through the afternoon into the early morning hours on Wednesday in Georgia. I will remind you that not everyone will experience severe weather and/or tornadoes.

Without getting into technical details [ weather speak ] here’s the latest outlook from various National Weather Service office’s around the southeast. Click image to enlarge.

Here’s the outlook from the Storm Prediction Center on 12/23/12 AM. This outlook will be updated on Monday and Tuesday Morning and throughout the day Tuesday December 25 2012.

I’ll be keeping an eye on this for further developments.

Technical details [ weather speak ]- 12z NAM and 12z GFS Severe parameters look strong for Mississippi, Alabama, Georgia and Northern Florida and a tad weaker [Lifted index and Cape] in East Georgia, still looks more than adequate for severe storms at this time.

Looking at latest data from the 12z NAM and 12z GFS, it appears the system has slowed somewhat. Nonetheless Wind Shear is still quite strong with a Jet Streak of 80+ knots on the 12z NAM and 90 knots on the 12z GFS in the areas mentioned above.

The lifted index on both models is -1 to -3 and approaching -5 on the NAM Late Wednesday night. Cape on the NAM is in the 1500 to 1750 Jkg Tuesday evening and around 750 on the GFS during the same time frame. I suspect a feedback issue here.

I expect backing winds will increase the threat of Tornadoes as time goes on. Also depending on cloud cover and rain or lack thereof ahead of the system the overall strength will increase due to heating allowed. Dewpoints will be in the high 50’s to mid 60’s and approaching the 70’s along the gulf coast adding instability and will be transported north.

Be sure to follow me on twitter where I post information when severe weather is happening including radar images and most if not all Tornado and Severe Warnings with information as to location and where the storms are headed. Follow @Cataulagawx

If you’re local to the Columbus GA, Ft Benning GA, Phenix City Al area, you can also follow my posts on Facebook https://www.facebook.com/CataulaGaWeather

Posted 1:50 PM EST 12/23/2012