Alert archive / Oklahoma / Severe Thunderstorm Watches in 2017

Severe Thunderstorm Watch 519

December 4, 20177 counties in Arkansas; 13 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Dec 4, 2017, 3:39 PM CST for 7 counties in Arkansas; 13 counties in Oklahoma. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Dec 4, 2017, 3:39 PM CST (21:39 UTC)
Expired
Dec 4, 2017, 8:09 PM CST
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt

Counties Benton County, AR, Carroll County, AR, Crawford County, AR, Franklin County, AR, Madison County, AR, Sebastian County, AR, Washington County, AR, Adair County, OK, Cherokee County, OK, Choctaw County, OK, Delaware County, OK, Haskell County, OK, Latimer County, OK, LeFlore County, OK, McIntosh County, OK, Muskogee County, OK, Ottawa County, OK, Pittsburg County, OK, Pushmataha County, OK, Sequoyah County, OK

The radar

The Western Arkansas radar (KSRX), 74 km from the middle of the area, began a volume at 21:40 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
2%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Dec 4, 4:29 PM CSTSevere Thunderstorm WarningTSAHaskell, McIntosh, Muskogee, Sequoyah46 min
Dec 4, 4:37 PM CSTSevere Thunderstorm WarningTSALatimer, Pittsburg23 min
Dec 4, 4:50 PM CSTSevere Thunderstorm WarningTSABenton40 min
Dec 4, 5:13 PM CSTSevere Thunderstorm WarningTSASequoyah34 min
Dec 4, 5:30 PM CSTSevere Thunderstorm WarningTSAHaskell, Latimer, LeFlore30 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

Springfield, MO (KSGF), launched 12:00Z, 9.7 hours before the alert went out and 112 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, Springfield, MO at 12:00Z on 2017-12-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Springfield, MO at 12:00Z on 2017-12-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 367 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
840 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
367 m²/s²
0-3 km storm-relative helicity
360 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 4, 1:26 PM CSTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Johnson and 10 more94 min
Dec 4, 5:34 PM CSTMesoscale DiscussionSPCBenton, Boone, Carroll, Conway, Crawford, Franklin and 20 more86 min
Dec 4, 2:34 PM CSTSevere Thunderstorm WatchSPCAdair, Audrain, Barry, Barton, Bates, Benton and 55 more5 hr
Dec 4, 3:57 PM CSTMesoscale DiscussionSPCAdair, Audrain, Barry, Barton, Benton, Boone and 53 more93 min

Nearby

Severe Thunderstorm Watches in Oklahoma, 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.