Mesoscale Discussion 2103 NWS Storm Prediction Center Norman OK 1147 AM CDT Mon Oct 21 2019
Areas affected...southeast Louisiana...southeast Mississippi...southwest Alabama and the far western Florida Panhandle
Concerning...Severe potential...Watch possible
Valid 211647Z - 211815Z
Probability of Watch Issuance...60 percent
SUMMARY...Threat for isolated damaging wind and a couple of tornadoes should persist into the afternoon along the central Gulf Coast region from southeast LA through southeast AL and the far western FL Panhandle. Trends are being monitored for a WW.
DISCUSSION...Late this morning an MCV embedded within a general area of rain is located west of the New Orleans area, moving east northeast. Storms have intensified over southeast LA within zone of convergence south of the MCV. Diabatic heating of the moist boundary layer with temperatures warming into the low to mid 80s F is occurring east of the thicker cirrus plume across the central Gulf Coast region, but MLCAPE should remain below 1000 J/kg due to moist adiabatic mid-level lapse rates. The primary low-level jet is forecast to shift north of the more unstable portion of the warm sector, but a weaker secondary low-level jet associated with the MCV will maintain low-level hodographs (150-200 m2/s2 storm relative helicity) sufficient for a few embedded low-level mesocyclones. However, the dominant convective mode will probably remain linear. Some intensification of the line may occur as it moves into a destabilizing boundary layer, supporting a threat for isolated strong to damaging wind gusts and a couple of tornadoes this afternoon.
Severe Thunderstorm Warning National Weather Service New Orleans LA 1237 PM CDT Mon Oct 21 2019
The National Weather Service in New Orleans has issued a
* Severe Thunderstorm Warning for... West central St. Bernard Parish in southeastern Louisiana... Southeastern St. Charles Parish in southeastern Louisiana... Southwestern Orleans Parish in southeastern Louisiana... Northwestern Jefferson Parish in southeastern Louisiana... Northwestern Plaquemines Parish in southeastern Louisiana...
* Until 130 PM CDT.
* At 1237 PM CDT, a severe thunderstorm was located near Avondale, moving northeast at 30 mph.
HAZARD...60 mph wind gusts.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include... New Orleans, Chalmette, Avondale, Marrero, Harvey, East New Orleans, Timberlane, Belle Chasse, Metairie, Jefferson, Gretna, Harahan, Westwego, Poydras, River Ridge, Estelle, Woodmere, Elmwood, Violet and Terrytown.
For your protection move to an interior room on the lowest floor of a building.
Just saw this on social media Ascension Parish Traffic Problems Facebook page: Reports of a possible tornado 🌪 in the area of Enterprise Tbone Plant on Hwy 75 in Geismar causing minor damage.
Geismer [Ascension Co, LA] TRAINED SPOTTER reports TSTM WND DMG at 12:01 PM CDT -- POSSIBLE TORNADO. REPORT OF DAMAGE OFF OF HWY 75 NEAR GEISMAR. POWER LINES REPORTED DOWN, AND ONE INJURY REPORTED DUE TO FALLING BRICKS. TIME ESTIMATED BASED ON RADAR.
Mesoscale Discussion 2104 NWS Storm Prediction Center Norman OK 0149 PM CDT Mon Oct 21 2019
Areas affected...western Florida Panhandle into south-central Alabama
Concerning...Severe potential...Watch possible
Valid 211849Z - 212115Z
Probability of Watch Issuance...40 percent
SUMMARY...Isolated low-topped rotating showers are likely to continue developing in the northern Gulf of Mexico and across southern Alabama and the western Florida Panhandle through the afternoon.
DISCUSSION...A few low-topped showers have developed across southern Alabama and offshore from the western Florida Panhandle in the last 1-2 hours. While no CG lightning has been observed (via Vaisala NLDN), these storms are weakly rotating via KEVX. Modest buoyancy is limiting the depth of these storms to around 10-13,000 feet with a subsidence layer residing around 800-675 mb per observations and mesoanalysis. High-level cirrus from the MCS to the west is limiting surface heating over the northern Gulf and central Gulf Coast, but enough instability is present to foster isolated convection. Deep layer shear (40-50 knots effective bulk shear) and low-level veering with height winds being enhanced by a wind shift/pseudo-warm front south of the Florida Panhandle, will likely result in rotating storms. A brief, weak tornado and strong wind gusts are possible with these discrete storms through the afternoon.
Should not be anything severe but widespread rain is likely....2-4 inches with isolated higher amounts possible. At least it should fall over a period of time and not all at once, but yeah, Friday looking awfully soggy and stormy.