Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 847, NWS Norman, OK

September 18, 2017Caddo County, Comanche County, Cotton County, Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Sep 18, 2017, 12:20 AM CDT for Caddo County, Comanche County, Cotton County, Oklahoma. It was in force for 40 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
Sep 18, 2017, 12:20 AM CDT (05:20 UTC)
Expired
Sep 18, 2017, 1:00 AM CDT
In force
40 min
Issued by
NWS Norman, OK
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Caddo County, OK, Comanche County, OK, Cotton County, OK

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 5.3 hours before the alert went out and 108 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, Norman, OK at 00:00Z on 2017-09-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 380 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, Norman, OK at 00:00Z on 2017-09-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 square meters per square second.19395878Sfc1 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
380 J/kg
Mixed-layer CIN
-121 J/kg
Mixed-layer LCL
1027 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-1.5

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 Norman, OK wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 17, 7:16 PM CDT, 5 hours 4 minutes earlier.

Area forecast discussion, Sep 17, 7:16 PM CDT, 5 hours 4 minutes before
Area Forecast Discussion
National Weather Service Norman OK
716 PM CDT Sun Sep 17 2017

.DISCUSSION...

&&

.AVIATION...
Showers and thunderstorms will be scattered across some of
central and southern Oklahoma overnight. East winds north of a
weak front across southern Oklahoma will turn south as the front
dissolves by mid-day Monday. VFR conditions are expected outside
of the few intense thunderstorms.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  71  91  72  93 /  40  20  10  10
Hobart OK         69  92  72  96 /  50  10  10  20
Wichita Falls TX  73  93  73  97 /  20  10  10  10
Gage OK           64  92  69  95 /  50  20  20  10
Ponca City OK     69  89  70  93 /  40  40  20  10
Durant OK         70  91  72  93 /  10  10   0  10

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&

25/09/09
Hazardous weather outlook, Sep 17, 9:07 PM CDT, 3 hours 13 minutes before
Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
907 PM CDT Sun Sep 17 2017

OKZ004>048-050>052-TXZ083>090-190215-
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-
907 PM CDT Sun Sep 17 2017

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

.DAY ONE...Rest of Tonight...

.Thunderstorms...
Showers and storms will continue to develop and move across
portions of Oklahoma and western north Texas through early Monday
morning. A few of the storms in parts of southern Oklahoma and
western north Texas could become strong to severe with hail up to
the size of half dollars and wind gusts to 65 mph. Otherwise,
heavy rain and cloud to ground lightning will be the main
concerns.

.DAYS TWO THROUGH SEVEN...Monday through Saturday...

.Thunderstorms...
Remnant thunderstorms will be possible Monday morning across
portions of central and eastern Oklahoma. Additional
thunderstorms may develop Monday afternoon across northern
Oklahoma, where there is Marginal Risk for strong to severe
thunderstorms. Hail and gusty winds are the primary hazards.

A low chance of thunderstorms will return on Thursday with
increasing chances of thunderstorms toward the upcoming weekend.
Locally heavy rainfall will be possible, especially by Saturday.

.Fire Weather...
Elevated fire weather conditions will be possible across portions
of Oklahoma and north Texas from Tuesday through Friday of this
week due to hot temperatures, breezy conditions, and low relative
humidity.

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

In the hours before

Local storm report, Sep 17, 11:31 PM CDT, 49 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
1131 PM CDT SUN SEP 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1029 PM     TSTM WND DMG     ALTUS                   34.64N 99.33W
09/17/2017                   JACKSON            OK   TRAINED SPOTTER

            POWER LINES DOWN IN ALTUS

&&

SC
Special weather statement, Sep 17, 11:36 PM CDT, 44 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1136 PM CDT SUN SEP 17 2017

OKZ037-TXZ085-086-180500-
Tillman OK-Wichita TX-Wilbarger TX-
1136 PM CDT SUN SEP 17 2017

...SIGNIFICANT WEATHER ADVISORY FOR southern Tillman...northwestern
Wichita and east central Wilbarger Counties Until midnight CDT...

AT 1133 PM CDT, strong thunderstorms were along a line extending from
near Hollister to near Harrold, moving east at 20 MPH.

HAZARDS INCLUDE...
Wind gusts over 50 MPH...
Minor flooding in areas of poor drainage...

Locations impacted include...
Electra, Grandfield, Davidson, Hollister, Loveland, Oklaunion,
Harrold and Haynesville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 3410 9916 3437 9911 3433 9861 3429 9861
      3396 9876
TIME...MOT...LOC 0433Z 272DEG 18KT 3435 9892 3406 9903

MAHALE
Local storm report, Sep 17, 11:47 PM CDT, 33 minutes before
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Special weather statement, Sep 17, 11:47 PM CDT, 33 minutes before
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      <h1 id="headline">This service is currently unavailable.</h1>
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Local storm report, Sep 17, 11:53 PM CDT, 27 minutes before
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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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Special weather statement, Sep 18, 12:10 AM CDT, 10 minutes before
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</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
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        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

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

IssuedProductOfficeCountiesLasted
Sep 17, 7:43 PM CDTSpecial Weather StatementOUNPontotoc47 min
Sep 17, 7:59 PM CDTSpecial Weather StatementOUNLove46 min
Sep 17, 8:26 PM CDTSpecial Weather StatementOUNGreer, Harmon49 min
Sep 17, 8:44 PM CDTAreal Flood AdvisoryOUNLove2 hr
Sep 17, 9:24 PM CDTSpecial Weather StatementOUNGreer, Harmon51 min
Sep 17, 10:18 PM CDTSpecial Weather StatementOUNKiowa42 min
Sep 17, 10:40 PM CDTSpecial Weather StatementOUNKiowa35 min
Sep 17, 11:17 PM CDTSpecial Weather StatementOUNTillman43 min
Sep 17, 11:36 PM CDTSpecial Weather StatementOUNTillman24 min
Sep 17, 11:40 PM CDTSevere Thunderstorm WarningOUNComanche, Cotton, Tillman50 min
Sep 17, 11:47 PM CDTSpecial Weather StatementOUNJackson43 min
Sep 18, 12:10 AM CDTSpecial Weather StatementOUNJackson35 min
Sep 18, 12:16 AM CDTSevere Thunderstorm WarningOUNJackson, Tillman23 min
Sep 18, 12:40 AM CDTSpecial Weather StatementOUNTillman35 min
Sep 18, 1:01 AM CDTSpecial Weather StatementOUNCotton, Grady, Stephens29 min
Sep 18, 5:44 AM CDTSpecial Weather StatementOUNWoodward31 min
Sep 18, 6:15 AM CDTSpecial Weather StatementOUNAlfalfa, Major, Woods, Woodward30 min
Sep 18, 6:45 AM CDTSpecial Weather StatementOUNAlfalfa, Garfield, Major45 min
Sep 17, 8:14 PM CDTAreal Flood AdvisoryOUNClay2 hr
Sep 17, 9:37 PM CDTSpecial Weather StatementOUNHardeman23 min
Sep 17, 11:21 PM CDTSpecial Weather StatementOUNHardeman24 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2017Every 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.