Alert archive / Louisiana / Tornado Watches in 2017
Tornado Watch 101
The Storm Prediction Center issued this tornado watch at Mar 29, 2017, 7:26 PM CDT for Ashley County, Chicot County, Arkansas; 37 parishes in Louisiana; 25 counties in Mississippi. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 29, 2017, 7:26 PM CDT (00:26 UTC)
- Expired
- Mar 30, 2017, 3:00 AM CDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 64 counties
Ashley County, AR, Chicot County, AR, Acadia Parish, LA, Allen Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Richland Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Tensas Parish, LA, Vermilion Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Bolivar County, MS, Carroll County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lawrence County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Rankin County, MS, Sharkey County, MS, Simpson County, MS, Sunflower County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS
The radar
The Ft Polk radar (KPOE), 82 km from the middle of the area, began a volume at 00:30 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 40%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 30%
- One or more gusts of 65 knots or more
- 10%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 60%
Warnings issued inside it
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 29, 7:53 PM CDT | Flash Flood Warning | LCH | Calcasieu, Cameron, Jefferson Davis | 6 hr |
| Mar 29, 8:00 PM CDT | Tornado Warning | LCH | Acadia, Jefferson Davis | 30 min |
| Mar 29, 8:27 PM CDT | Severe Thunderstorm Warning | LCH | Acadia, Evangeline, Lafayette, Saint Landry | 48 min |
| Mar 29, 8:27 PM CDT | Tornado Warning | LCH | Allen, Evangeline, Rapides | 12 min |
| Mar 29, 8:36 PM CDT | Severe Thunderstorm Warning | JAN | East Carroll, Richland, West Carroll | 54 min |
| Mar 29, 8:50 PM CDT | Severe Thunderstorm Warning | LCH | Iberia, Lafayette, Saint Landry, Saint Martin, St. Mary, Vermilion | 40 min |
| Mar 29, 9:24 PM CDT | Severe Thunderstorm Warning | JAN | Chicot | 45 min |
| Mar 29, 10:30 PM CDT | Flash Flood Warning | LCH | Acadia, Allen, Evangeline, Jefferson Davis, Saint Landry | 6 hr |
| Mar 29, 10:43 PM CDT | Severe Thunderstorm Warning | JAN | Concordia, Tensas | 47 min |
| Mar 29, 11:04 PM CDT | Tornado Warning | JAN | Adams, Jefferson | 41 min |
| Mar 30, 12:01 AM CDT | Severe Thunderstorm Warning | JAN | Franklin, Jefferson, Lincoln | 44 min |
| Mar 30, 12:12 AM CDT | Severe Thunderstorm Warning | JAN | Claiborne, Copiah, Hinds | 63 min |
| Mar 30, 12:31 AM CDT | Severe Thunderstorm Warning | LCH | Cameron, Vermilion | 44 min |
| Mar 30, 12:42 AM CDT | Severe Thunderstorm Warning | JAN | Copiah, Lincoln | 52 min |
| Mar 30, 1:11 AM CDT | Severe Thunderstorm Warning | JAN | Hinds, Madison, Rankin, Yazoo | 36 min |
| Mar 30, 1:42 AM CDT | Flash Flood Warning | LCH | Saint Landry | 5 hr |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Lake Charles Mun, LA (KLCH), launched 00:00Z, 0.4 hours before the alert went out and 161 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
- 1539 J/kg
- Mixed-layer CIN
- -1 J/kg
- Mixed-layer LCL
- 662 m above ground
- 0-6 km bulk shear
- 56 kt
- 0-1 km storm-relative helicity
- 157 m²/s²
- 0-3 km storm-relative helicity
- 162 m²/s²
- Significant tornado parameter
- 1.1
- Supercell composite
- 4.5
The text
As transmitted.
208 WWUS20 KWNS 300021 SEL1 SPC WW 300021 ARZ000-LAZ000-MSZ000-CWZ000-300800- URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 101 NWS Storm Prediction Center Norman OK 720 PM CDT Wed Mar 29 2017 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Extreme southeastern Arkansas Southwestern through northeastern Louisiana Western Mississippi Coastal Waters * Effective this Wednesday night and Thursday morning from 720 PM until 300 AM CDT. * Primary threats include... A couple tornadoes possible Isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...The threat for severe weather, with clusters of thunderstorms, is expected to spread northeastward across the watch area through the remainder of this evening and overnight, before diminishing late tonight. A few tornadoes are possible, along with damaging winds and isolated large hail. See SPC mesoscale discussion 370 for initial meteorological details. The tornado watch area is approximately along and 60 statute miles east and west of a line from 40 miles west southwest of Intracoastal City LA to 25 miles northeast of Greenville MS. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 98. Watch number 98 will not be in effect after 720 PM CDT. CONTINUE...WW 99...WW 100... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 23030. ...Edwards
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 29, 7:34 PM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Clark, Conway, Fulton, Garland and 23 more | 86 min |
| Mar 29, 9:44 PM CDT | Mesoscale Discussion | SPC | Baxter, Cleburne, Faulkner, Fulton, Independence, Izard and 6 more | 91 min |
| Mar 29, 9:58 PM CDT | Mesoscale Discussion | SPC | Ashley, Chicot, Drew | 92 min |
| Mar 30, 1:34 AM CDT | Mesoscale Discussion | SPC | Ascension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 10 more | 86 min |
| Mar 30, 11:10 AM CDT | Mesoscale Discussion | SPC | Harrison, Jackson | 65 min |
Nearby
Tornado Watches in Louisiana, 2017Tornado Watches in Mississippi, 2017Tornado Watches in Arkansas, 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; radar from the NEXRAD Level II archive.