Alert archive / Oklahoma / Heat Advisories in 2021

Heat Advisory 23, NWS Norman, OK

August 31, 202128 counties in Oklahoma

NWS Norman, OK issued this heat advisory at Aug 31, 2021, 12:04 PM CDT for 28 counties in Oklahoma. It took effect at Sep 1, 2021, 12:00 PM CDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Aug 31, 2021, 12:04 PM CDT (17:04 UTC)
In effect from
Sep 1, 2021, 12:00 PM CDT
Expired
Sep 1, 2021, 7:00 PM CDT
In force
7 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 17:10 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

Springfield, MO (KSGF), launched 12:00Z, 5.1 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-pSkew-T log-p diagram, Springfield, MO at 12:00Z on 2021-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 13 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, Springfield, MO at 12:00Z on 2021-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 33 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
13 J/kg
Mixed-layer CIN
-212 J/kg
Mixed-layer LCL
1345 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
33 m²/s²
0-3 km storm-relative helicity
54 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 31, 6:19 AM CDT, 5 hours 45 minutes earlier.

Area forecast discussion, Aug 31, 6:19 AM CDT, 5 hours 45 minutes before
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Hazardous weather outlook, Aug 31, 12:01 PM CDT, 3 minutes before
Hazardous Weather Outlook
National Weather Service Norman OK
1201 PM CDT Tue Aug 31 2021

OKZ004>048-050>052-TXZ083>090-011715-
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-
1201 PM CDT Tue Aug 31 2021

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

.DAY ONE...Today and Tonight...

.Thunderstorms...
A few isolated storms may develop in parts of south central and
southeast Oklahoma, near the Red River, this afternoon. Brief
heavy rain and gusty winds are the main concerns. The potential
for any storms is expected to end after sunset.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday...

.Heat...
Triple digit heat indices will be possible for at least parts of
the area Wednesday through Friday with the highest and most
widespread indices expected Wednesday afternoon when values could
reach 105 or higher. A Heat Advisory will be in effect Wednesday
afternoon across southeast and portions of central and northern
Oklahoma.  Take steps to prevent heat related illnesses.

.Thunderstorms...
Showers and thunderstorms will be possible across portions of
northern Oklahoma Thursday and Friday with more widespread low
chances over the weekend.

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

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 31, 1:06 PM CDTSpecial Weather StatementOUNComanche24 min
Aug 31, 1:16 PM CDTSpecial Weather StatementOUNComanche29 min

Nearby

Heat Advisories in Oklahoma, 2021Every 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.