Alert archive / Alabama / Tornado Watches in 2017

Tornado Watch 362

June 21, 201711 counties in Alabama; 7 counties in Florida; 11 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jun 21, 2017, 6:45 PM CDT for 11 counties in Alabama; 7 counties in Florida; 11 counties in Mississippi. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Jun 21, 2017, 6:45 PM CDT (23:45 UTC)
Expired
Jun 22, 2017, 2:59 AM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt
All 29 counties

Baldwin County, AL, Butler County, AL, Clarke County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Escambia County, AL, Geneva County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Bay County, FL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Forrest County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Lamar County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 37 km from the middle of the area, began a volume at 23:49 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
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

12 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Jun 21, 6:45 PM CDTTornado WarningMOBCovington45 min
Jun 21, 7:16 PM CDTTornado Warning Tornado observedMOBCovington, Crenshaw19 min
Jun 21, 7:37 PM CDTSevere Thunderstorm WarningMOBOkaloosa53 min
Jun 21, 7:41 PM CDTSevere Thunderstorm WarningMOBEscambia39 min
Jun 21, 8:51 PM CDTTornado WarningMOBCovington24 min
Jun 21, 9:10 PM CDTSevere Thunderstorm WarningMOBOkaloosa35 min
Jun 21, 9:21 PM CDTTornado WarningMOBOkaloosa22 min
Jun 21, 10:36 PM CDTFlash Flood WarningMOBButler, Covington, Crenshaw6 hr
Jun 22, 1:04 AM CDTTornado WarningTAEGeneva26 min
Jun 22, 1:14 AM CDTTornado WarningMOBCovington46 min
Jun 22, 1:44 AM CDTSevere Thunderstorm WarningMOBBaldwin41 min
Jun 22, 2:24 AM CDTFlash Flood WarningMOBCovington, Escambia6 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 11.8 hours before the alert went out and 185 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.

Skew-T log-pSkew-T log-p diagram, Slidell Radar S, LA at 12:00Z on 2017-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 262 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 12:00Z on 2017-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 485 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
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

Open this sounding in Storm Lab

The text

As transmitted.

383 
WWUS20 KWNS 212343
SEL2  
SPC WW 212343
ALZ000-FLZ000-MSZ000-CWZ000-220800-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 362
NWS Storm Prediction Center Norman OK
645 PM CDT Wed Jun 21 2017

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Southern Alabama
  Western Florida Panhandle
  Southern Mississippi
  Coastal Waters

* Effective this Wednesday night and Thursday morning from 645 PM
  until 300 AM CDT.

* Primary threats include...
  A couple tornadoes possible
  Isolated damaging wind gusts to 70 mph possible

SUMMARY...A few tornadoes and damaging wind gusts will remain
possible across the watch area this evening and tonight, as showers
and thunderstorms rotate inland around TS Cindy.

The tornado watch area is approximately along and 65 statute miles
north and south of a line from 40 miles northwest of Gulfport MS to
20 miles east northeast of Panama City FL. For a complete depiction
of the watch see the associated watch outline update (WOUS64 KWNS
WOU2).

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...CONTINUE...WW 359...WW 360...WW 361...

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.

...Hart

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 8:15 PM CDTMesoscale DiscussionSPCBaldwin, Mobile3 hr
Jun 20, 9:48 PM CDTMesoscale DiscussionSPCBaldwin, Mobile57 min
Jun 20, 10:24 PM CDTTornado WatchSPCBaldwin, Mobile12 hr
Jun 21, 2:08 AM CDTMesoscale DiscussionSPCBaldwin, Mobile2 hr
Jun 21, 7:47 AM CDTMesoscale DiscussionSPCBaldwin, Mobile118 min
Jun 21, 10:01 AM CDTTornado WatchSPCBaldwin, Covington, Escambia, Mobile9 hr
Jun 21, 3:42 PM CDTMesoscale DiscussionSPCBaldwin, Mobile93 min
Jun 21, 6:29 PM CDTMesoscale DiscussionSPCBaldwin, Conecuh, Covington, Escambia, Mobile, Washington61 min

Nearby

Tornado Watches in Alabama, 2017Tornado Watches in Mississippi, 2017Tornado Watches in Florida, 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.