Alert archive / Oklahoma / Special Weather Statements in 2021

Special Weather Statement, NWS Norman, OK

July 18, 2021Greer County, Oklahoma

NWS Norman, OK issued this special weather statement at Jul 18, 2021, 8:21 PM CDT for Greer County, Oklahoma. It was in force for 24 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
Jul 18, 2021, 8:21 PM CDT (01:21 UTC)
Expired
Jul 18, 2021, 8:45 PM CDT
In force
24 min
Issued by
NWS Norman, OK

County Greer County, OK

The radar

The Altus AFB radar (KFDR), 75 km from the middle of the area, began a volume at 01:20 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

Amarillo Airport, TX (KAMA), launched 00:00Z, 1.4 hours before the alert went out and 198 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, Amarillo Airport, TX at 00:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 775 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Amarillo Airport, TX at 00:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
775 J/kg
Mixed-layer CIN
-18 J/kg
Mixed-layer LCL
1818 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

As transmitted.

320 
WWUS84 KOUN 190121
SPSOUN

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
821 PM CDT Sun Jul 18 2021
 
OKZ034-036-190145-
Greer OK-Jackson OK-
821 PM CDT Sun Jul 18 2021

...SIGNIFICANT WEATHER ADVISORY FOR south central Greer and north
central Jackson Counties Until 845 PM CDT...

AT 816 PM CDT, a strong thunderstorm was located 5 miles west of
Mangum, moving southeast at 30 MPH.

HAZARDS INCLUDE...
Hail up to the size of nickels... 
Wind gusts to 50 MPH...

LAT...LON 3490 9973 3498 9954 3471 9931 3460 9960
TIME...MOT...LOC 0116Z 333DEG 25KT 3488 9960 

$$

..speg.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 7:02 PM CDTSevere Thunderstorm WarningOUNTillman43 min
Jul 18, 7:06 PM CDTSpecial Weather StatementOUNCleveland24 min
Jul 18, 7:19 PM CDTAreal Flood AdvisoryOUNCleveland4 hr
Jul 18, 7:23 PM CDTAreal Flood AdvisoryOUNAtoka, Coal, Hughes4 hr
Jul 18, 7:27 PM CDTSpecial Weather StatementOUNGrady33 min
Jul 18, 7:36 PM CDTSpecial Weather StatementOUNBeckham24 min
Jul 18, 7:58 PM CDTSpecial Weather StatementOUNPontotoc32 min
Jul 18, 8:56 PM CDTSpecial Weather StatementOUNJackson, Kiowa49 min
Jul 18, 8:58 PM CDTSpecial Weather StatementOUNCarter, Garvin, Murray32 min
Jul 18, 9:20 PM CDTSevere Thunderstorm WarningOUNJohnston, Marshall28 min
Jul 18, 9:59 PM CDTSpecial Weather StatementOUNTillman61 min
Jul 18, 10:03 PM CDTAreal Flood AdvisoryOUNCarter, Garvin, Johnston, McClain, Murray, Pottawatomie4 hr
Jul 18, 10:10 PM CDTAreal Flood AdvisoryOUNHarmon, Jackson5 hr
Jul 18, 10:49 PM CDTSpecial Weather StatementOUNPottawatomie26 min
Jul 19, 12:18 AM CDTAreal Flood AdvisoryOUNCaddo, Comanche, Grady3 hr
Jul 19, 1:03 AM CDTAreal Flood AdvisoryOUNComanche3 hr
Jul 19, 4:01 AM CDTAreal Flood AdvisoryOUNCarter, Jefferson, Love, Marshall, Murray, Stephens5 hr
Jul 19, 7:46 AM CDTAreal Flood AdvisoryOUNJohnston, Pontotoc3 hr
Jul 19, 8:12 AM CDTFlash Flood WarningOUNJohnston, Pontotoc3 hr
Jul 18, 10:20 PM CDTSpecial Weather StatementOUNFoard25 min
Jul 18, 11:40 PM CDTSpecial Weather StatementOUNArcher, Baylor, Clay, Wichita50 min
Jul 19, 12:22 AM CDTAreal Flood AdvisoryOUNArcher, Baylor3 hr
Jul 19, 12:49 AM CDTAreal Flood AdvisoryOUNArcher, Wichita3 hr
Jul 19, 3:46 PM CDTSpecial Weather StatementOUNFannin

Nearby

Special Weather Statements in Oklahoma, 2021Every special weather statement in 2021

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.