Alert archive / Tennessee / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 166

April 26, 20174 states

The Storm Prediction Center issued this severe thunderstorm watch at Apr 26, 2017, 5:02 PM CDT for 4 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Apr 26, 2017, 5:02 PM CDT (22:02 UTC)
Expired
Apr 26, 2017, 11:00 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 45 counties

Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Lee County, AR, Mississippi County, AR, Phillips County, AR, Poinsett County, AR, St. Francis County, AR, Dunklin County, MO, Pemiscot County, MO, Benton County, MS, Calhoun County, MS, Coahoma County, MS, DeSoto County, MS, Lafayette County, MS, Marshall County, MS, Panola County, MS, Pontotoc County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Carroll County, TN, Chester County, TN, Crockett County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN, Weakley County, TN

The radar

The Memphis radar (KNQA), 19 km from the middle of the area, began a volume at 22:05 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
10%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
50%
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
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 26, 5:23 PM CDTSevere Thunderstorm WarningMEGCraighead, Crittenden, Cross, Mississippi, Poinsett, St. Francis39 min
Apr 26, 5:43 PM CDTSevere Thunderstorm WarningMEGCrittenden, Mississippi47 min
Apr 26, 10:18 PM CDTSevere Thunderstorm WarningMEGChickasaw, Lee, Monroe, Pontotoc42 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

Little Rock, AR (KBYH), launched 12:00Z, 10.0 hours before the alert went out and 76 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, Little Rock, AR at 12:00Z on 2017-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 271 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, Little Rock, AR at 12:00Z on 2017-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 129 square meters per square second.19395878Sfc1 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
271 J/kg
Mixed-layer CIN
-181 J/kg
Mixed-layer LCL
821 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
160 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.9

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 10:51 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Washington54 min
Apr 25, 11:27 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more7 hr
Apr 26, 1:42 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Crawford, Franklin, Johnson and 10 more2 hr
Apr 26, 5:37 AM CDTMesoscale DiscussionSPCConway, Crawford, Franklin, Garland, Howard, Johnson and 14 more113 min
Apr 26, 6:00 AM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 23 more7 hr
Apr 26, 7:29 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 23 more2 hr
Apr 26, 9:39 AM CDTMesoscale DiscussionSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 47 more36 min
Apr 26, 10:08 AM CDTTornado WatchSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 51 more7 hr
Apr 26, 1:05 PM CDTMesoscale DiscussionSPCClark, Columbia, Dallas, Grant, Hempstead, Hot Spring and 9 more85 min
Apr 26, 3:53 PM CDTMesoscale DiscussionSPCClay97 min
Apr 26, 4:23 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 19 more67 min
Apr 26, 4:44 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 11 more5 hr
Apr 26, 6:10 PM CDTMesoscale DiscussionSPCMississippi95 min
Apr 25, 7:14 PM CDTMesoscale DiscussionSPCMcDonald91 min
Apr 26, 12:26 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Madison, Mississippi and 6 more94 min
Apr 26, 12:46 PM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Carter, Madison, Perry and 6 more6 hr

Nearby

Severe Thunderstorm Watches in Tennessee, 2017Severe Thunderstorm Watches in Mississippi, 2017Severe Thunderstorm Watches in Arkansas, 2017Every severe thunderstorm 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.