Alert archive / Oklahoma / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 651

September 26, 2012Crawford County, Sebastian County, Arkansas; 13 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Sep 26, 2012, 2:17 PM CDT for Crawford County, Sebastian County, Arkansas; 13 counties in Oklahoma. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued
Sep 26, 2012, 2:17 PM CDT (19:17 UTC)
Expired
Sep 26, 2012, 10:00 PM CDT
In force
8 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Crawford County, AR, Sebastian County, AR, Haskell County, OK, Hughes County, OK, Latimer County, OK, LeFlore County, OK, Lincoln County, OK, McIntosh County, OK, Muskogee County, OK, Okfuskee County, OK, Okmulgee County, OK, Pittsburg County, OK, Pottawatomie County, OK, Seminole County, OK, Sequoyah County, OK

The radar

The Tulsa radar (KINX), 78 km from the middle of the area, began a volume at 19:18 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
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Sep 26, 2:42 PM CDTSevere Thunderstorm WarningTSAMcIntosh, Okfuskee, Pittsburg63 min
Sep 26, 2:47 PM CDTSevere Thunderstorm WarningOUNHughes58 min
Sep 26, 3:45 PM CDTSevere Thunderstorm WarningTSAMcIntosh, Pittsburg60 min
Sep 26, 3:54 PM CDTSevere Thunderstorm WarningOUNHughes66 min
Sep 26, 4:21 PM CDTSevere Thunderstorm WarningTSAMcIntosh, Okfuskee, Pittsburg54 min
Sep 26, 4:41 PM CDTFlash Flood WarningTSAMcIntosh4 hr
Sep 26, 4:55 PM CDTFlash Flood WarningTSAPittsburg4 hr
Sep 26, 5:13 PM CDTSevere Thunderstorm WarningTSAPittsburg62 min
Sep 26, 7:38 PM CDTSevere Thunderstorm WarningTSAMcIntosh, Okmulgee52 min
Sep 26, 8:04 PM CDTSevere Thunderstorm WarningOUNHughes, Seminole41 min
Sep 26, 8:16 PM CDTFlash Flood WarningOUNHughes3 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

Norman, OK (KOUN), launched 12:00Z, 7.3 hours before the alert went out and 137 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, Norman, OK at 12:00Z on 2012-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 51 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, Norman, OK at 12:00Z on 2012-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
51 J/kg
Mixed-layer CIN
-540 J/kg
Mixed-layer LCL
1962 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
367 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 26, 1:26 PM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Cleburne, Craighead, Franklin and 17 more94 min
Sep 26, 2:04 PM CDTMesoscale DiscussionSPCSebastian86 min
Sep 25, 7:29 PM CDTSevere Thunderstorm WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 23 more4 hr
Sep 25, 9:33 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Comanche, Cotton and 18 more87 min
Sep 26, 1:50 PM CDTMesoscale DiscussionSPCCimarron, Texas55 min
Sep 26, 3:59 PM CDTSevere Thunderstorm WatchSPCBeaver, Cimarron, Texas7 hr

Nearby

Severe Thunderstorm Watches in Oklahoma, 2012Severe Thunderstorm Watches in Arkansas, 2012Every severe thunderstorm watch in 2012

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.