Alert archive / Louisiana / Tornado Watches in 2017
Tornado Watch 359
The Storm Prediction Center issued this tornado watch at Jun 21, 2017, 10:01 AM CDT for 4 states. It was in force for 9 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 21, 2017, 10:01 AM CDT (15:01 UTC)
- Expired
- Jun 21, 2017, 7:00 PM CDT
- In force
- 9 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 0.5 in
- Strongest gust expected
- 60 kt
All 52 counties
Baldwin County, AL, Covington County, AL, Escambia County, AL, Mobile County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Acadia Parish, LA, Ascension Parish, LA, Assumption Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Plaquemines Parish, LA, Pointe Coupee Parish, LA, Saint Bernard Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, Saint Tammany Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Terrebonne Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Amite County, MS, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Stone County, MS, Walthall County, MS, Wilkinson County, MS
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 50%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 20%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 50%
Warnings issued inside it
25 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 11:06 AM CDT | Flash Flood Warning | MOB | Butler, Conecuh, Covington, Escambia | 6 hr |
| Jun 21, 11:31 AM CDT | Flash Flood Warning | JAN | Lamar, Marion | 3 hr |
| Jun 21, 11:33 AM CDT | Tornado Warning | LIX | Orleans | 13 min |
| Jun 21, 12:05 PM CDT | Flash Flood Warning | MOB | Baldwin, Clarke, Conecuh, Escambia, Monroe, Washington | 6 hr |
| Jun 21, 12:53 PM CDT | Tornado Warning | LIX | Livingston, Saint John the Baptist, Tangipahoa | 37 min |
| Jun 21, 1:26 PM CDT | Tornado Warning | LIX | Livingston | 19 min |
| Jun 21, 2:15 PM CDT | Tornado Warning | MOB | Okaloosa, Santa Rosa | 45 min |
| Jun 21, 2:29 PM CDT | Tornado Warning | MOB | Baldwin | 46 min |
| Jun 21, 2:35 PM CDT | Tornado Warning | LIX | Hancock | 14 min |
| Jun 21, 2:44 PM CDT | Tornado Warning | MOB | Escambia | 30 min |
| Jun 21, 2:46 PM CDT | Tornado Warning | MOB | Baldwin | 59 min |
| Jun 21, 3:10 PM CDT | Tornado Warning | MOB | Baldwin | 25 min |
| Jun 21, 3:21 PM CDT | Severe Thunderstorm Warning | LIX | Orleans, Saint Tammany | 54 min |
| Jun 21, 3:21 PM CDT | Tornado Warning | LIX | Harrison | 24 min |
| Jun 21, 3:46 PM CDT | Flash Flood Warning | MOB | Baldwin, Clarke, Mobile, Washington | 6 hr |
| Jun 21, 3:48 PM CDT | Flash Flood Warning | JAN | Forrest, Lamar, Marion | 3 hr |
| Jun 21, 3:53 PM CDT | Tornado Warning | MOB | Baldwin | 52 min |
| Jun 21, 4:03 PM CDT | Tornado Warning | MOB | Greene | 17 min |
| Jun 21, 4:17 PM CDT | Tornado Warning | MOB | Escambia | 43 min |
| Jun 21, 4:52 PM CDT | Severe Thunderstorm Warning | MOB | Mobile | 38 min |
| Jun 21, 5:04 PM CDT | Severe Thunderstorm Warning | MOB | Baldwin, Mobile | 86 min |
| Jun 21, 5:48 PM CDT | Severe Thunderstorm Warning | MOB | Baldwin | 44 min |
| Jun 21, 5:51 PM CDT | Flash Flood Warning | MOB | Baldwin, Choctaw, Clarke, Conecuh, Escambia, Monroe and 1 more | 6 hr |
| Jun 21, 6:10 PM CDT | Severe Thunderstorm Warning | MOB | Baldwin | 26 min |
| Jun 21, 6:45 PM CDT | Tornado Warning | MOB | Covington | 45 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Slidell Radar S, LA (KSIL), launched 12:00Z, 3.0 hours before the alert went out and 67 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 262 J/kg
- Mixed-layer CIN
- -75 J/kg
- Mixed-layer LCL
- 465 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 485 m²/s²
- 0-3 km storm-relative helicity
- 506 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 5.3
The text
As transmitted.
644 WWUS20 KWNS 211457 SEL9 SPC WW 211457 ALZ000-FLZ000-LAZ000-MSZ000-CWZ000-220000- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 359 NWS Storm Prediction Center Norman OK 1000 AM CDT Wed Jun 21 2017 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Alabama Far Northwest Florida Southern Louisiana Southern Mississippi Coastal Waters * Effective this Wednesday morning and evening from 1000 AM until 700 PM CDT. * Primary threats include... A few tornadoes possible Isolated damaging wind gusts to 70 mph possible SUMMARY...A few storms will continue spread onshore to the northeast of Tropical Storm Cindy with potential for rotating storms to produce brief tornadoes. The tornado watch area is approximately along and 55 statute miles north and south of a line from 40 miles west of Lafayette LA to 15 miles east southeast of Pensacola FL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...This tornado watch replaces tornado watch number 358. Watch number 358 will not be in effect after 1000 AM CDT. AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 17025. ...Weiss
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 20, 8:15 PM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile | 3 hr |
| Jun 20, 9:48 PM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile | 57 min |
| Jun 20, 10:24 PM CDT | Tornado Watch | SPC | Baldwin, Mobile | 12 hr |
| Jun 21, 2:08 AM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile | 2 hr |
| Jun 21, 7:47 AM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile | 118 min |
| Jun 21, 3:42 PM CDT | Mesoscale Discussion | SPC | Baldwin, Mobile | 93 min |
| Jun 21, 6:29 PM CDT | Mesoscale Discussion | SPC | Baldwin, Conecuh, Covington, Escambia, Mobile, Washington | 61 min |
| Jun 21, 6:45 PM CDT | Tornado Watch | SPC | Baldwin, Butler, Clarke, Conecuh, Covington, Crenshaw and 5 more | 8 hr |
Nearby
Tornado Watches in Louisiana, 2017Tornado Watches in Mississippi, 2017Tornado Watches in Alabama, 2017Every tornado watch in 2017
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive.