Mesoscale Discussion 0075 NWS Storm Prediction Center Norman OK 1028 AM CST Wed Feb 05 2020
Areas affected...southwest through central Louisiana...southwest through central Mississippi and extreme western Alabama
Concerning...Severe potential...Watch likely
Valid 051628Z - 051800Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorms are expected to gradually increase in intensity and organization initially from southwest through central Louisiana, and eventually into southwest through central Mississippi into the afternoon. Supercells and bowing segments posing a risk for damaging wind and a few tornadoes will be the main threats. Trends are being monitored for a tornado watch.
DISCUSSION...A stationary front extends from northwest AL to a weak surface low in northern LA where it becomes a cold front and continuing into southeast TX. Forcing for ascent within the exit region of an upper jet rounding the base of an upper trough is beginning to overtake the western part of the warm sector across southwest through central LA. This is manifested by a recent increase in thunderstorms along and behind the front southwest LA through eastern TX. The southerly low-level jet will also respond and become coupled with the exit upper jet region, and is forecast to increase to 50+ kt this afternoon. The 12Z RAOB data from Lake Charles already showed moderate instability with 2500 J/kg MUCAPE in warm sector. Storms should soon become surface based and organize as supercells as temperatures rise through the low 70s F. The storms will subsequently spread northeast into MS this afternoon. The strengthening low and mid-level jets will support 50+ kt effective bulk shear and 200-300 m2/s2 storm relative helicity with largest hodographs expected east of the northeast migrating surface low.
Special Weather Statement National Weather Service New Orleans LA 1038 AM CST Wed Feb 5 2020
LAZ039-040-064-069-070-072-MSZ077-080-051730- Washington-Lower Plaquemines-Upper St. Bernard-Southern Tangipahoa-Lower St. Bernard-St. Tammany-Hancock-Pearl River- 1038 AM CST Wed Feb 5 2020
...A LINE OF STRONG THUNDERSTORMS WILL AFFECT CENTRAL ST. BERNARD... ST. TAMMANY...SOUTHEASTERN TANGIPAHOA...NORTH CENTRAL PLAQUEMINES AND SOUTHEASTERN WASHINGTON PARISHES...HANCOCK AND SOUTHERN PEARL RIVER COUNTIES...
At 1038 AM CST, radar indicated strong thunderstorms were located along a line extending from 7 miles southwest of Madisonville to 8 miles northwest of Lake Catherine to 10 miles northeast of Violet to 7 miles southwest of Shell Beach. Movement was northeast at 45 mph.
Winds in excess of 30 mph are possible with these storms.
Locations impacted include... Slidell, Bogalusa, Picayune, Covington, Diamondhead, Pearl River, Abita Springs, Madisonville, Sun, Kiln, Pearlington, Lacombe, Crossroads, Shoreline Park, Stennis Space Center, Bush, Mcneil, Shell Beach and Slidell Airport.
Torrential rainfall is also occurring with these storms, and may cause localized flooding. Do not drive your vehicle through flooded roadways.
That severe storm in west Louisiana looks to have hail with it on radar returns. Also, a watch will be issued soon!
Maybe some smaller hail. Looking at some of the dual pol returns, it looks like it could be really heavy rain but the CC is suggestive of some hail in there. At least something melting. It's worth noting the LCH sounding had the wet bulb zero about 3000' below LIX. Hail more likely over there.
Curious to see the reports from the area.
Did a quick look at the NAM and HRRR, and so far the 3k NAM did a better job at depicting what is currently happening.
Severe Thunderstorm Warning National Weather Service Lake Charles LA 1049 AM CST Wed Feb 5 2020
The National Weather Service in Lake Charles has issued a
* Severe Thunderstorm Warning for... Northwestern Beauregard Parish in southwestern Louisiana... Southwestern Vernon Parish in west central Louisiana... Northeastern Newton County in southeastern Texas...
* Until 1130 AM CST.
* At 1049 AM CST, a severe thunderstorm was located over Singer, moving northeast at 45 mph.
HAZARD...60 mph wind gusts and quarter size hail.
IMPACT...Hail damage to vehicles is expected. Expect wind damage to roofs, siding, and trees.
* Locations impacted include... Rosepine, Merryville, Singer, De Ridder, Deridder, Tulla, Junction and Evans.
For your protection move to an interior room on the lowest floor of a building.
Prepare immediately for large hail and damaging winds. People outside should move immediately to shelter inside a strong building. Stay away from windows.
Mesoscale Discussion 0076 NWS Storm Prediction Center Norman OK 1116 AM CST Wed Feb 05 2020
Areas affected...Southeastern Louisiana...far southern Mississippi...southwestern Alabama...western Florida Panhandle
Concerning...Severe potential...Watch possible
Valid 051716Z - 051915Z
Probability of Watch Issuance...40 percent
SUMMARY...Low-level wind fields on KLIX/KMOD VAD suggest potential for low-level storm rotation. Storm mode and upstream precipitation should limit the overall threat, but isolated strong wind gusts and a brief tornado are possible. Should trends in storm intensity increase, a WW will be considered.
DISCUSSION...A cluster of storms has develop over the past 2 hours across portions of the Mississippi Delta region and progress northeastward. Storms along the southwestern flank of this activity have shown some transient and weak low-level rotation. Updrafts have remained rather weak with only a few cells showing 50 dBZ cores on the 7 km CAPPI. This is likely due to warm air aloft that was evident on the 12Z LIX and JAN soundings. Further limiting the strength of this activity will be the ongoing rainfall downstream of the stronger cores in LA/MS. Nevertheless, modest to moderate low-level SRH (around 100-200 m2/s2 in the 0-1 km layer) on KLIX/KMOD VAD profiles suggest some storm rotation is possible. Despite the negative factors, isolated strong wind gusts and a brief tornado are possible particularly along the southwestern flank where inflow would be less impacted by precipitation. Trends in storm intensity will be monitored for possible WW issuance.
Post by thermalwind on Feb 5, 2020 11:30:31 GMT -6
I think you got hail in the cell near Leesville and the one on the edge of the warning box. Differential Reflectivity is showing a hail core there on the edge of the polygon like due east from Fort Polk.