The National Weather Service Storm Prediction Center in Norman, Oklahoma has revised their forecast of a severe weather outbreak on Friday. They have now moved the Jasper/Lakes area into the enhanced risk zone, which now stretches from the ArkLaTex down through the Sabine River Valley to the Golden Triangle.
They have also specified their timing for this area, saying that our greatest risk will be from late afternoon to late night on Friday.
Meteorologists say tornadoes, damaging straight-line winds, and cloud-to-ground lightning are probable.
On Saturday the problem area shifts to the east as Louisiana, Mississippi, and Alabama will be facing the probability of a severe weather event.
The following statement was released by the Storm Prediction Center on Wednesday morning:
NWS Storm Prediction Center Norman OK
0230 AM CST Wed Jan 08 2020
Valid 101200Z - 111200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF FAR SOUTHEAST OK...EASTERN TX...NORTHERN AND SOUTHWEST LA AND SOUTHERN AR...
Severe thunderstorms are possible Friday afternoon into early Saturday morning across portions of the Arklatex into the lower Mississippi Valley vicinity. Damaging wind gusts and tornadoes will be the main threats with these storms.
A volatile weather pattern continues to be apparent for Friday from eastern TX/OK into the lower MS Valley. An intense mid/upper shortwave trough over the southern Rockies into northern Mexico will intensify as it shifts east into the southern Plains through the end of the period. Most guidance shows a 100+ kt 500 mb jet streak spreading across eastern OK/TX after 00z, with a 60+ kt south/southwesterly low level jet developing over the Arklatex/Sabine River vicinity by 00z. Guidance varies some in the development of a surface low, located somewhere from north TX to northern OK Friday morning. The low will deepen as it shifts east/northeast across AR to near the MO Bootheel vicinity by Saturday morning.
While the evolution of the surface low remains a bit uncertain, strong south/southeasterly low level flow ahead of the low and its associated cold front, will bring rich Gulf moisture northward across eastern OK/TX and the lower MS Valley. Upper 60s F to low 70s F dewpoints over eastern and coastal TX will spread eastward across LA/southern AR and into MS and southwest AL by 12z Saturday. Atop this anomalously moist boundary layer, steep midlevel lapse rates courtesy of an EML spreading east/northeast from the Mexican Plateau will result in pockets of MLCAPE from 750-1500 J/kg from eastern TX into LA and adjacent portions of AR/MS where stronger heating is expected. Further north, where temperatures and dewpoints will be lower, instability will quickly diminish to less than 500 J/kg into the mid-MS Valley. Mixed convective mode is likely, with a QLCS developing in the vicinity of the surface cold front by late afternoon across OK/north TX. Intense shear will aid in damaging wind potential and very moist low levels, combined with backed low level flow/strong SRH, will support mesovortex development along the line. The QLCS will develop east/northeast through the overnight hours.
Additionally concerning is any convection that develops across the warm sector ahead of the front/QLCS. Guidance continues to indicate that more discrete warm sector development is possible, across parts of eastern TX into LA. Supercells capable of all severe hazards, some possibly significant, appear most probable across this area from late afternoon into the overnight hours.