Alert archive / Arkansas / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 286, NWS Little Rock, AR

August 11, 2017Grant County, Jefferson County, Arkansas

NWS Little Rock, AR issued this severe thunderstorm warning at Aug 11, 2017, 12:21 PM CDT for Grant County, Jefferson County, Arkansas. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 11, 2017, 12:21 PM CDT (17:21 UTC)
Expired: Aug 11, 2017, 1:00 PM CDT
In force: 39 min
Issued by: NWS Little Rock, AR
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Grant County, AR, Jefferson County, AR

The radar

The Little Rock radar (KLZK), 62 km from the middle of the area, began a volume at 17:24 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.

The nearest sounding before it

Little Rock, AR (KBYH), launched 12:00Z, 5.4 hours before the alert went out and 213 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1097 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 851 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 52 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Little Rock, AR wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 11, 6:59 AM CDT, 5 hours 22 minutes earlier.

Area forecast discussion, Aug 11, 6:59 AM CDT, 5 hours 22 minutes before

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Hazardous weather outlook, Aug 11, 4:07 AM CDT, 8 hours 14 minutes before

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In the hours before

Special weather statement, Aug 11, 12:00 PM CDT, 21 minutes before

Special Weather Statement
National Weather Service Little Rock AR
1200 PM CDT FRI AUG 11 2017

ARZ043>046-054>056-111745-
Pulaski AR-Hot Spring AR-Grant AR-Lonoke AR-Prairie AR-Saline AR-
Jefferson AR-
1200 PM CDT FRI AUG 11 2017

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL PRAIRIE...LONOKE...
GRANT...NORTHWESTERN JEFFERSON...SOUTHEASTERN SALINE...SOUTHEASTERN
PULASKI AND EAST CENTRAL HOT SPRING COUNTIES UNTIL 1245 PM CDT...

At 1200 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near McAlmont to near Wrightsville to near East
End to near Perla. Movement was east at 35 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Little Rock...                    North Little Rock...
Pine Bluff...                     Sherwood...
Jacksonville...                   Malvern...
Sheridan...                       Lonoke...
White Hall...                     England...
Carlisle...                       Wrightsville...
Redfield...                       Tull...
Prattsville...                    Poyen...
Humnoke...                        Keo...
Perla...                          Barrettsville...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with these storms, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3487 9164 3458 9173 3442 9185 3417 9206
      3432 9288 3452 9245 3464 9227 3486 9220
TIME...MOT...LOC 1700Z 277DEG 29KT 3479 9216 3464 9220 3452 9239 3435
9274

57

The office that day

Everything else NWS Little Rock, AR issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 11, 12:00 PM CDT	Special Weather Statement	LZK	Grant, Lonoke	45 min
Aug 11, 12:31 PM CDT	Severe Thunderstorm Warning	LZK	Jackson, White, Woodruff	15 min
Aug 11, 1:00 PM CDT	Special Weather Statement	LZK	Arkansas, Jefferson	45 min
Aug 11, 1:09 PM CDT	Special Weather Statement	LZK	Hot Spring	51 min
Aug 11, 1:45 PM CDT	Special Weather Statement	LZK	Clark	30 min
Aug 11, 2:08 PM CDT	Special Weather Statement	LZK	Cleveland	52 min
Aug 11, 2:11 PM CDT	Severe Thunderstorm Warning	LZK	Bradley, Cleveland, Drew, Lincoln	34 min
Aug 11, 2:36 PM CDT	Special Weather Statement	LZK	Ouachita	39 min
Aug 11, 2:40 PM CDT	Special Weather Statement	LZK	Drew	35 min
Aug 11, 3:03 PM CDT	Severe Thunderstorm Warning	LZK	Bradley, Calhoun, Ouachita	42 min
Aug 11, 3:26 PM CDT	Severe Thunderstorm Warning	LZK	Ouachita	34 min
Aug 11, 3:29 PM CDT	Severe Thunderstorm Warning	LZK	Drew	16 min
Aug 11, 3:49 PM CDT	Special Weather Statement	LZK	Bradley	41 min

Nearby

Severe Thunderstorm Warnings in Arkansas, 2017 Every severe thunderstorm warning 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.