EXPECTED HARDEST HIT STATES - Texas, Oklahoma, southeastern Kansas, southern Missouri, Louisianna, Mississippi, Arkansas, western Kentucky and Tennessee....
TIMELINE....
WEDNESDAY ....Eastern Oklahoma, eastern Texas, southern Kansas...
WEDNESDAY NIGHT ....Arkansas, southern Missouri, northern Louisianna, northwestern Mississippi, northeastern Texas, western Tennessee, western Kentucky...
THURSDAY.....Southeastern Mississippi, central and eastern Tennessee, southeastern Kentucky, Alabama, Georgia...
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DISCUSSION ....
It's basically last week all over again with a few minor tweaks and changes here and there. Warm and humid air will surge northward out of the Gulf of Mexico as an upper level low pressure system moves out of the front range and into the plains states. Surface winds out of the south turn southwest and eventually west-southwest with height providing plenty of shearing. Surface instability is pretty high as well with dewpoints in the 60's and lifted indicies of -5 to -8 all up and down the plains. CAPE values are moderate to severe with most locations between 1500 to 2000 j/kg. Finally EHI values (Energy Helicity Index) and 0-3 km Helicity numbers both are very high across eastern Texas,eastern Oklahoma and western Arkansas. These values correlate strongly with the development of rotating updrafts and supercell thunderstorms.
Here's an example of what were looking at on Wednesday....normally we would like to see 0-3km Helicity numbers of at least 200 to start worrying about supercells. Well some of the forecast guidence is showing locations over 400 Wednesday evening with this upcoming event. EHI values of 1 to 2 have been known to be associated with significant tornadoes within supercell thunderstorms. Some of the forecast guidence shows EHI numbers for this event across some of the area between 3 and 4.
So dynamically the pieces to the puzzle are all there. The moisture is there, the upper level energy is there, the surface feature is there. If everything comes together just right there could be a large number of tornadoes Wednesday and Wednesday Night. A good estimate at this time would be somewhere in the line of 40 -60 tornadoes with more possible farther east on Thursday. Some of these tornadoes do have the potential to be large and very destructive EF3's.
Please keep it tuned to your local weather source and myweatherlive.com for the latest severe weather developments.
-CS
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The Storm Prediction Center has a SLIGHT RISK for severe weather issued for portions of the southern plains to the Ozarks and the lower Mississippi River Valley....
A MODERATE RISK has not been issued as of yet but more than likely will be by tomorrow morning for northeastern Texas, southeastern Oklahoma and maybe extreme western Arkansas...
