Alert archive / Arkansas / Special Weather Statements in 2017

Special Weather Statement, NWS Tulsa, OK

April 21, 2017Polk County, Arkansas

NWS Tulsa, OK issued this special weather statement at Apr 21, 2017, 10:10 PM CDT for Polk County, Arkansas. It was in force for 20 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Apr 21, 2017, 10:10 PM CDT (03:10 UTC)
Expired
Apr 21, 2017, 10:30 PM CDT
In force
20 min
Issued by
NWS Tulsa, OK

County Polk County, AR

The radar

The Western Arkansas radar (KSRX), 72 km from the middle of the area, began a volume at 03:10 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

Shreveport, LA (KBAD), launched 00:00Z, 3.2 hours before the alert went out and 252 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 00:00Z on 2017-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 828 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 00:00Z on 2017-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
828 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1486 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
143 m²/s²
Significant tornado parameter
0.2
Supercell composite
4.5

Open this sounding in Storm Lab

The text

As transmitted.

548 
WWUS84 KTSA 220310
SPSTSA

Special Weather Statement
National Weather Service Tulsa OK
1010 PM CDT FRI APR 21 2017
 
OKZ076-220330-
Le Flore OK-
1010 PM CDT FRI APR 21 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LE FLORE COUNTY
UNTIL 1030 PM CDT...

At 1010 PM CDT, a strong thunderstorm was located 3 miles northwest
of Mountain Fork, moving east at 50 mph.

Nickel size hail will be possible with this storm.

This storm will remain over mainly rural areas of southeastern Le
Flore County.

A tornado watch remains in effect until 100 AM CDT for southeastern
Oklahoma.

LAT...LON 3470 9459 3474 9445 3457 9446 3456 9455
TIME...MOT...LOC 0310Z 256DEG 44KT 3467 9448 

$$

The office that day

Everything else NWS Tulsa, OK issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 7:44 PM CDTSpecial Weather StatementTSAPushmataha46 min
Apr 21, 8:06 PM CDTSevere Thunderstorm WarningTSAPushmataha39 min
Apr 21, 8:22 PM CDTSpecial Weather StatementTSAChoctaw38 min
Apr 21, 8:44 PM CDTSpecial Weather StatementTSAMcCurtain46 min
Apr 21, 8:48 PM CDTSevere Thunderstorm WarningTSAChoctaw57 min
Apr 21, 9:45 PM CDTSpecial Weather StatementTSAChoctaw30 min
Apr 22, 3:11 PM CDTRiver Flood AdvisoryTSAMuskogee6 days
Apr 21, 8:33 PM CDTSpecial Weather StatementTSAMadison27 min

Nearby

Special Weather Statements in Arkansas, 2017Every special weather statement 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.