Good evening everyone!
The Storm Prediction Center, Norman, OK. has issued a MODERATE risk of Severe Thunderstorms FROM EAST TEXAS ACROSS MUCH OF LOUISIANA…SOUTHEAST ARKANSAS…WESTERN TENNESSEE AND ALL OF WESTERN MISSISSIPPI…
…THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE MDT RISK AREA FROM EAST TX THE UPPER TX GULF COAST NORTHEAST TO THE OH RIVER VALLEY…TN VALLEY AND NORTHERN GULF COAST… .
..SEVERE WEATHER OUTBREAK POSSIBLE ACROSS PARTS OF THE LOWER MISSISSIPPI RIVER VALLEY ON SATURDAY…
Analysis this afternoon and evening of forecast severe weather sounding parameters indicates the greatest threat for severe thunderstorms will lie within the 30% probability area in the probabilistic map.
The greatest threat for tornadic activity appears to lie within the hatched area. Based on analysis of the GFS and NAVGEM solutions of various severe weather parameters based on F5 Data severe weather software, including but not limited to forecast lifted indices, SWEAT Index, Storm Relative Helicity, Craven- Brooks values, etc. the severe event could initiate as early as 8 – 9 a.m. CDT. The area with the greatest risk for tornadoes, possibly EF2 -EF3 from approximately 9 a.m. to 12 p.m. EST is outlined in blue in the following map:
After this time frame, based on the probability that the atmosphere will most likely remain conducive for severe weather overnight, as the threat shifts North and East, the likelihood for severe weather is outlined in blue, with tornadic activity a possibility early in the period outlined in orange, then after 6 p.m. EST over the portion circled over Ohio.
Ingredients at the time of analysis indicated a vigorous LLJ (Low Level Jet), Mid level jet, and a fairly strong Jetstreak in the upper levels. Ample humidity is also forecast at the low and mid levels of the atmosphere. Wind shear, both directional and speed should provide enough helicity for rotational supercells.
Bear in mind, this current synopsis is based on information analyzed late this afternoon, and some things will most likely change by tomorrow.
I will analyze severe weather index parameters again in the a.m., as well as morning soundings from around the risk areas, particularly in the MODERATE risk area, and will try to update before noon time. The possibility could exist for this to become a PDS, however I will make this determination after completion of analysis in the morning.
Have a blessed evening!
T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)