Moisture already beginning to be pulled north from the Gulf of Mexico ahead of this next system. This system is more potent that the one we saw earlier this week move across the south. It also looks to be faster.
Louisiana and Mississippi
Impacts will be felt in Louisiana beginning Wednesday Night moving quickly into Mississippi by Thursday morning. The greatest threat will be damaging winds of 60 mph plus that will accompany a squall line that is expected to develop. Due to strong wind shear and forcing to the surface, it is likely a few tornadoes will spin up quickly. These types of quick spin ups are hard to detect on radar and usually occur without Tornado Warnings being issued.
Outlook for Wednesday December 19 2012
Alabama and Georgia
It all comes down to timing as to what will happen in Alabama and Georgia. If it comes in later than anticipated I expect a more robust system with more widespread thunderstorms some that will turn severe. If it comes in earlier than anticipated I expect some thundershowers and a few thunderstorms. NOT EVERYONE WILL SEE SEVERE WEATHER. Just as the storm system Yesterday, It didn’t get bad until it was to our south and east.
At this time I expect the main line of stronger storms should they develop to enter the east Alabama area between 12 and 2 PM CST [Thursday] and West Georgia shortly after. This timing is subject to change in the next day or so. We’ll just have to keep an eye on this and see what happens. Right now our area is highlighted just as it was yesterday for a ‘slight risk’ of stronger thunderstorms.
It seems our Second Severe Season has arrived albeit a bit late. Normally the fall severe weather begins in Mid to late November in the southeast. November this year was quite with the exception of a potential severe weather event in the southeast that never materialized during the Nov. 11th thru 13th time frame. If you were around this past week you may recall the Storms and Tornadoes in the Southeast on December 10 2012. on with the show …
This coming bout of potential Severe weather will begin Late Saturday in the ARK-LA-MISS area shifting east with time into Alabama, Georgia and northern Florida. There remains uncertainty with the system as to timing and how strong storms may become due to how strong the upper level low pressure expected to develop in the northern tiers of this region becomes. The stronger the ULL, the more moisture it will pull north from the Gulf of Mexico into an already somewhat unstable air mass closer to the coast and extending northward. Regardless, am expecting some strong storms with isolated severe at this time throughout the region beginning today thru Monday again spreading west to east. Right now [5:05 AM EST 12/15/2012] confidence is somewhat LOW to the severe side based on how much cloud cover and rain occurs ahead of the frontal system in the warm sector.
Threats with this system will be in the form of Isolated strong to severe storms with the potential for a few Tornadoes with stronger storms possible. While the threat of tornadoes looks low at this time, a couple can’t be entirely ruled out due to increasing shear layer to layer which may became surface based over time supporting Bowing Line areas capable of Damaging Straight Line winds and Isolated Supercells which may spawn a Tornado. There is also a threat of Flash Flooding in areas with 1 to 2 inches of rain expected. As always .. not everyone will experience severe storms.
Today through Tomorrow morning the main threat will be the possibility of Damaging winds associated with strong thunderstorms that may develop generally in the afternoon and evening hours continuing through the overnight. … On Sunday the possibility of severe storms increase and continues into the overnight into Monday. On Sunday the Storm Prediction Center at this time [5:17 AM EST 12/15/2012] has an area highlighted for an elevated risk for strong to severe storms. We’ll see how this area looks later today for possible increase in severity or even a decrease. For now here is what they have for Sunday Morning through Monday Morning. [click image to embiggen]
Here’s the anticipated Rain Amounts Today through Tuesday Morning
Don’t forget 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
Tornadic Debris Signature – 0.5 degree correlation coefficient (CC) of Dual Pol from KBMX. There are 3 images in this loop. Notice the “explosion” of CC just east of I-65 on the last two images. This is called a Tornadic Debris Signature or TDS.
Marion County Tornado – These images from the Brandon, MS doppler radar show the tornadic thunderstorm at 8:20 am as the tornado passed near Columbia. The image on the left shows 0.5° base reflectivity data, and the image on the right shows 0.5° storm relative velocity data.
Side note : An active weather pattern continues next week and the following week. Next week may bring some interesting winter weather to the deep southeast per current models or severe storms depending where you’re at. Still a lot of uncertainty in this forecast as models continue to flip flop on final outcome. Computer models should have a better idea this weekend and I’ll post an update then. ~ Ed