Alert archive / Oklahoma / Heat Advisories in 2021

Heat Advisory 18, NWS Norman, OK

August 21, 202128 counties in Oklahoma

NWS Norman, OK issued this heat advisory at Aug 21, 2021, 1:38 PM CDT for 28 counties in Oklahoma. It took effect at Aug 22, 2021, 12:00 PM CDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued: Aug 21, 2021, 1:38 PM CDT (18:38 UTC)
In effect from: Aug 22, 2021, 12:00 PM CDT
Expired: Aug 22, 2021, 8:00 PM CDT
In force: 8 hr
Issued by: NWS Norman, OK

All 28 counties

Atoka County, OK, Bryan County, OK, Canadian County, OK, Carter County, OK, Cleveland County, OK, Coal County, OK, Garfield County, OK, Garvin County, OK, Grady County, OK, Grant County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Kay County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Noble County, OK, Oklahoma County, OK, Payne County, OK, Pontotoc County, OK, Pottawatomie County, OK, Seminole County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 25 km from the middle of the area, began a volume at 18:41 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

Springfield, MO (KSGF), launched 12:00Z, 6.6 hours before the alert went out and 360 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 751 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: -158 m²/s²
0-3 km storm-relative helicity: -249 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 heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Norman, OK wrote its last area forecast discussion before this heat advisory went out at Aug 21, 1:21 PM CDT, 17 minutes earlier.

Area forecast discussion, Aug 21, 1:21 PM CDT, 17 minutes before

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Hazardous weather outlook, Aug 21, 11:49 AM CDT, 1 hour 49 minutes before

Hazardous Weather Outlook
National Weather Service Norman OK
1149 AM CDT Sat Aug 21 2021

OKZ004>048-050>052-TXZ083>090-221700-
Harper-Woods-Alfalfa-Grant-Kay-Ellis-Woodward-Major-Garfield-
Noble-Roger Mills-Dewey-Custer-Blaine-Kingfisher-Logan-Payne-
Beckham-Washita-Caddo-Canadian-Oklahoma-Lincoln-Grady-McClain-
Cleveland-Pottawatomie-Seminole-Hughes-Harmon-Greer-Kiowa-Jackson-
Tillman-Comanche-Stephens-Garvin-Murray-Pontotoc-Coal-Cotton-
Jefferson-Carter-Johnston-Atoka-Love-Marshall-Bryan-Hardeman-
Foard-Wilbarger-Wichita-Knox-Baylor-Archer-Clay-
1149 AM CDT Sat Aug 21 2021

This hazardous weather outlook is for portions of northern...
western...central...and southern Oklahoma...and western north
Texas.

.DAY ONE...Through Tonight...

.Heat...
Hot and humid conditions will lead to heat indices ranging from
105 to 110 degrees this afternoon and evening. These conditions
could cause heat related illness, particularly for those working
or participating in outdoor activities.

.Thunderstorms...
There is a marginal risk of severe thunderstorms this afternoon
and evening for northern and central Oklahoma. The main hazards
will be damaging wind gusts and heavy, localized rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday...

.Heat...
Hot and humid conditions will continue into next week.

Get graphics and more details at weather.gov/norman...and follow
our weather forecast office on Twitter and Facebook.

Mahale

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 21, 1:00 AM CDT	Special Weather Statement	OUN	Grant	30 min
Aug 21, 2:36 AM CDT	Heat Advisory	OUN	Atoka, Bryan, Canadian, Carter, Cleveland, Coal and 18 more	17 hr
Aug 21, 3:32 PM CDT	Special Weather Statement	OUN	Jackson	28 min
Aug 21, 3:40 PM CDT	Special Weather Statement	OUN	Ellis	35 min
Aug 21, 3:52 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OUN	Ellis	38 min
Aug 21, 4:01 PM CDT	Special Weather Statement	OUN	Dewey	29 min
Aug 21, 4:11 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OUN	Dewey	49 min
Aug 21, 4:32 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OUN	Ellis, Woodward	43 min
Aug 21, 5:05 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OUN	Dewey, Major, Woodward	40 min
Aug 21, 5:19 PM CDT	Severe Thunderstorm Warning	OUN	Blaine, Dewey	41 min
Aug 21, 5:22 PM CDT	Special Weather Statement	OUN	Kingfisher	23 min
Aug 21, 5:29 PM CDT	Severe Thunderstorm Warning	OUN	Kingfisher	46 min
Aug 21, 5:31 PM CDT	Special Weather Statement	OUN	Roger Mills	29 min
Aug 21, 5:35 PM CDT	Areal Flood Advisory	OUN	Dewey	3 hr
Aug 21, 5:43 PM CDT	Severe Thunderstorm Warning	OUN	Dewey, Major, Woodward	47 min
Aug 21, 6:03 PM CDT	Special Weather Statement	OUN	Custer	27 min
Aug 21, 6:10 PM CDT	Special Weather Statement	OUN	Blaine	35 min
Aug 21, 6:14 PM CDT	Special Weather Statement	OUN	Dewey	31 min
Aug 21, 6:17 PM CDT	Severe Thunderstorm Warning Considerable damage threat	OUN	Kingfisher	23 min
Aug 21, 6:21 PM CDT	Severe Thunderstorm Warning	OUN	Kingfisher, Logan	39 min
Aug 21, 6:25 PM CDT	Severe Thunderstorm Warning	OUN	Lincoln	50 min
Aug 21, 6:33 PM CDT	Areal Flood Advisory	OUN	Dewey, Ellis, Roger Mills	3 hr
Aug 21, 6:56 PM CDT	Special Weather Statement	OUN	Kingfisher	34 min

Nearby

Heat Advisories in Oklahoma, 2021 Every heat advisory 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.