SIGNIFICANT TORNADO AND SEVERE WEATHER OUTBREAK IS ON THE WAY.....
EXPECTED HARDEST HIT STATES
THIS AFTERNOON
eastern Oklahoma
Arkansas
northern Louisianna
Mississippi
southern Missouri
western Tennessee
TONIGHT
Arkansas
Louisianna
Mississippi
Alabama
western Tennessee
western and southern Kentucky
SUNDAY
southern and eastern Alabama
Georgia
South Carolina
North Carolina
northern Florida
A very dangerous weather situation is in the process of developing today as a violent clash between colder air to the north and warm and humid air to the south will cause widestread severe weather across the lower Mississippi River Valley and the Southern states. Large hail, damaging winds and large, destructive tornadoes are all expected later this afternoon, this evening and during the overnight.
A couple of fronts will interact with the unstable air across the area today, each bringing with it a round of severe weather. The first round will be associated with or just to the north of the warm front that is slowly moving northward and stretching from eastern Oklahoma, through Arkansas and into central Mississippi and Alabama. This front will be the focal point for storms that will have the potential to produce large destructive tornadoes. The second round will be associated with the dry line as it pushes through eastern Oklahoma and northeastern Texas by late afternoon. Tornadoes and damaging winds will be possible with this feature. Finally, by the evening and into the overnight a squall line will then develop with the the third and final front..... the cold front. Damaging straight line winds (Bow Echos) and very large hail will be the main threats with this front.
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The image below is courtesy of the National Weather Service in Little Rock Arkansas and depicts the area that is expected to get hit the hardest with tornadoes.
This circled area is where the air will be the most unstable... 0-1 km Helicity values (rotation) are very high in some locations, well within tornado range spiking over 250 m2 / s2. The surface instability is quite high as well with dewpoints in the 60's and 70's and temperatures in the mid 70's to mid 80's.
In the upper levels a strengthening low level jet will swing through as the upper level trough moves out of the Rockies and into the southern plains states. In the image below do you see how the two lines are diverging (moving apart) near the area in grey that says LIFT. When air aloft diverges it forces the surface air to rise to fill in that area aloft. So now not only do we have a very unstable surface environment but we have the upper level support as well.
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The Storm Prediction Center has expanded the MODERATE RISK area today. It now stretches across the Arklatex and mid south region eastward across the Gulf Coast States later today and tonight.
A SLIGHT RISK for severe weather surrounds the moderate risk from the southern plains eastward to the Atlantic Coast and northward to the lower Ohio Valley.
