Alert archive / Arkansas / Tornado Watches in 2015

Tornado Watch 151

May 9, 201519 counties in Arkansas; McCurtain County, Oklahoma; 7 counties in Texas

The Storm Prediction Center issued this tornado watch at May 9, 2015, 2:40 PM CDT for 19 counties in Arkansas; McCurtain County, Oklahoma; 7 counties in Texas. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2015, 2:40 PM CDT (19:40 UTC)
Expired
May 9, 2015, 10:00 PM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 27 counties

Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Sevier County, AR, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Morris County, TX, Red River County, TX, Titus County, TX

The radar

The Shreveport radar (KSHV), 165 km from the middle of the area, began a volume at 19:41 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
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
50%
One or more gusts of 65 knots or more
5%
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
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 9, 3:03 PM CDTFlash Flood WarningSHVHoward117 min
May 9, 3:15 PM CDTFlash Flood WarningSHVHoward, Little River, Sevier3 hr
May 9, 3:27 PM CDTSevere Thunderstorm WarningLZKPike63 min
May 9, 3:29 PM CDTSevere Thunderstorm WarningSHVHempstead, Howard, Sevier46 min
May 9, 4:34 PM CDTSevere Thunderstorm WarningLZKClark, Garland, Hot Spring, Montgomery26 min
May 9, 4:47 PM CDTFlash Flood WarningLZKClark, Garland, Hot Spring, Montgomery, Pike, Scott and 1 more3 hr
May 9, 5:11 PM CDTSevere Thunderstorm WarningSHVBowie, Cass, Morris64 min
May 9, 5:22 PM CDTTornado WarningSHVFranklin, Red River, Titus38 min
May 9, 5:30 PM CDTTornado WarningSHVFranklin, Morris, Red River, Titus45 min
May 9, 5:33 PM CDTTornado WarningSHVBowie42 min
May 9, 6:12 PM CDTSevere Thunderstorm WarningSHVLittle River63 min
May 9, 6:12 PM CDTSevere Thunderstorm WarningSHVMcCurtain63 min
May 9, 6:16 PM CDTTornado WarningSHVFranklin, Red River, Titus34 min
May 9, 6:17 PM CDTTornado WarningSHVLittle River43 min
May 9, 6:24 PM CDTSevere Thunderstorm WarningLZKDallas, Grant, Hot Spring, Jefferson, Pulaski, Saline51 min
May 9, 6:58 PM CDTTornado WarningSHVHempstead, Little River, Miller47 min
May 9, 7:14 PM CDTSevere Thunderstorm WarningSHVLittle River, Sevier61 min
May 9, 7:16 PM CDTTornado WarningSHVLittle River, Sevier44 min
May 9, 7:25 PM CDTTornado WarningSHVHempstead, Little River, Miller50 min
May 9, 7:47 PM CDTSevere Thunderstorm WarningSHVHempstead, Howard, Little River, Miller, Sevier43 min
May 9, 8:10 PM CDTTornado WarningSHVColumbia, Lafayette, Nevada50 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

Shreveport, LA (KBAD), launched 12:00Z, 7.7 hours before the alert went out and 167 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, Shreveport, LA at 12:00Z on 2015-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1263 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, Shreveport, LA at 12:00Z on 2015-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 130 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
1263 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
612 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
130 m²/s²
0-3 km storm-relative helicity
156 m²/s²
Significant tornado parameter
0.5
Supercell composite
4.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

668 
WWUS20 KWNS 091937
SEL1  
SPC WW 091937
ARZ000-OKZ000-TXZ000-100300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 151
NWS STORM PREDICTION CENTER NORMAN OK
240 PM CDT SAT MAY 9 2015

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF 
  SOUTHWEST ARKANSAS
  FAR SOUTHEAST OKLAHOMA
  NORTHEAST TEXAS

* EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 240 PM UNTIL
  1000 PM CDT.

* PRIMARY THREATS INCLUDE...
  A COUPLE TORNADOES POSSIBLE
  SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
  ISOLATED VERY LARGE HAIL EVENTS TO 2 INCHES IN DIAMETER POSSIBLE

SUMMARY...BROKEN SQUALL LINE WITH EMBEDDED SUSTAINED
STORMS/SUPERCELLS EXPECTED TO MOVE GENERALLY EAST INTO WATCH AREA
THROUGH MID-EVENING...WITH A RISK FOR ISOLATED TORNADOES...SEVERE
HAIL...AND LOCALLY DAMAGING WIND.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 110 STATUTE
MILES EAST AND WEST OF A LINE FROM 35 MILES NORTHEAST OF DE QUEEN
ARKANSAS TO 65 MILES SOUTHWEST OF TEXARKANA ARKANSAS.  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...CONTINUE...WW 149...WW 150...

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
500. MEAN STORM MOTION VECTOR 25030.


...CORFIDI

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 8, 10:43 PM CDTMesoscale DiscussionSPCClark, Garland, Hempstead, Howard, Lafayette, Little River and 8 more92 min
May 9, 9:41 AM CDTMesoscale DiscussionSPCHoward, Little River, Polk, Sevier2 hr
May 9, 1:58 PM CDTMesoscale DiscussionSPCClark, Conway, Faulkner, Franklin, Garland, Hempstead and 20 more92 min
May 9, 5:06 PM CDTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 18 more54 min
May 9, 5:52 PM CDTMesoscale DiscussionSPCClark, Columbia, Hempstead, Lafayette, Little River, Miller and 2 more83 min
May 8, 7:27 PM CDTTornado WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Creek and 18 more6 hr
May 9, 3:11 AM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Texas8 hr
May 9, 4:03 AM CDTMesoscale DiscussionSPCComanche, Cotton, Greer, Harmon, Jackson, Kiowa and 1 more57 min
May 9, 5:51 AM CDTMesoscale DiscussionSPCBeaver, Beckham, Blaine, Cimarron, Comanche, Custer and 14 more84 min
May 9, 7:36 AM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Cleveland and 22 more6 hr
May 9, 11:36 AM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Comanche, Cotton, Greer and 7 more84 min
May 9, 1:21 PM CDTTornado WatchSPCAtoka, Bryan, Caddo, Canadian, Carter, Cleveland and 23 more10 hr
May 9, 3:32 PM CDTMesoscale DiscussionSPCBryan, Carter, Coal, Cotton, Garvin, Hughes and 10 more118 min
May 9, 4:52 PM CDTMesoscale DiscussionSPCBeckham, Greer, Harmon, Roger Mills83 min
May 8, 8:42 PM CDTMesoscale DiscussionSPCAndrews, Borden, Callahan, Coke, Coleman, Concho and 28 more2 hr
May 8, 10:48 PM CDTMesoscale DiscussionSPCAndrews, Borden, Callahan, Coke, Crane, Crockett and 26 more87 min
May 9, 2:34 AM CDTMesoscale DiscussionSPCAndrews, Bailey, Castro, Cochran, Dallam, Dawson and 14 more116 min
May 9, 6:21 PM CDTMesoscale DiscussionSPCBrown, Coleman, Comanche, Eastland, Erath, Hood and 6 more84 min

Nearby

Tornado Watches in Arkansas, 2015Tornado Watches in Texas, 2015Tornado Watches in Oklahoma, 2015Every tornado watch in 2015

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.