February 24th & 25th 2011 Severe Weather Threat

Something different this time to talk about for the United States than what I have talked about.  We are getting closer to spring and that means severe weather is knocking at the backdoor.  As a matter of fact, that's exactly what is happening right now for the Southern Mississippi Valley.  There is a potential for some severe weather to be seen in Louisiana, Mississippi, Arkansas, eastern Texas, Tennessee, and Alabama.  Here is the current convective outlook from Thursday 1200Z (6:00 AM) to Friday 1200Z (6:00 AM) from the Storm Prediction Center. 
What this is showing is the risks of severe weather.  The brown line shows the general area where severe weather is possible.  The important lines are the green "slight" risk line and, more important, the red "moderate" line.  The slight risk line is saying that all the states and parts of states within that line are in a slight risk of severe thunderstorms.  The moderate risk line is saying that every portion of the states inside that line are in a moderate risk of seeing severe thunderstorms.  This may not seem like much, but allow me to put this in perspective for you.  The Storm Prediction Center will issue slight risk on the day 2 convective outlook, but it isn't common for the Storm Prediction Center to issue a moderate risk on a day 2 convective outlook which indicates that something in the atmosphere is going to mix just right to create severe weather.  If you are wondering what the percentages or probabilities of severe weather for this region is here is a map to show you. 
The pink 45% line is telling us that the area within that line has a 45% or higher chance of seeing some severe weather.  The same goes for 30%, 15% and 5%.  There is another signifcant color surrounding the 45% line and that's a blue line that's hatched inside.  What this is telling us is that the hatchet area has a 10% or greater chance of significant severe weather which means that cities such as Tunica, MS; Memphis, TN; Texarkana, TX & AR; and Little Rock, AR.  What is the difference you ask?  It is basically the difference between experiencing a severe thunderstorm to just produce lightning and heavy rain to a thunderstorm that could produce strong winds, hail, and the possibility of a tornado.  If you would like to read the discussion on why this could happen and the details to it then visit http://www.spc.noaa.gov/products/outlook/day2otlk.html.

Several NWS offices are showing various graphics on this severe weather threat.  I will show you images from NWS offices from 4 different NWS offices.  Here is what the NWS in Little Rock, AR is showing on the severe weather for Thursday. 

Now an image from the NWS in Shreveport, LA. 

Images from the NWS in Jackson, MS. 

Finally an image from the NWS in Memphis, TN. 

The point of all these is to see the perspective from each NWS office that is going to be experiencing the severe weather for tomorrow.  The highest threat stays around the Memphis area and west TN, northern MS, and most of Arkansa.  Alabama was mentioned at the beginning to get the severe weather and they will, but they will see the highest probability of severe weather on Friday.

I will keep everyone updated on the severe weather threat tomorrow as it progresses on things start to unfold.  I will also post more images tomorrow on an updated blog on this event pertaining to Alabama and other areas that will be effected with this event on Friday.  If you would like to see and read more details of this event from the previous NWS offices here are the thinks to each one for you to look at.  For Little Rock, AR: http://www.srh.noaa.gov/lzk/, for Shreveport, LA: http://www.srh.noaa.gov/shv/, for Jackson, MS: http://www.srh.noaa.gov/jan/, and Memphis, TN: http://www.srh.noaa.gov/meg/.