Alert archive / Oklahoma / Flash Flood Warnings in 2017

Flash Flood Warning 111, NWS Norman, OK

October 21, 20174 counties in Oklahoma

NWS Norman, OK issued this flash flood warning at Oct 21, 2017, 9:02 PM CDT for 4 counties in Oklahoma. It was in force for 118 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: Oct 21, 2017, 9:02 PM CDT (02:02 UTC)
Expired: Oct 21, 2017, 11:00 PM CDT
In force: 118 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Flood severity: None

Counties Cleveland County, OK, Lincoln County, OK, Logan County, OK, Oklahoma County, OK

The radar

The Norman radar (KTLX), 18 km from the middle of the area, began a volume at 02:05 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 2.0 hours before the alert went out and 31 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: 1764 J/kg
Mixed-layer CIN: -20 J/kg
Mixed-layer LCL: 974 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 207 m²/s²
0-3 km storm-relative helicity: 226 m²/s²
Significant tornado parameter: 1.9
Supercell composite: 10.8

Open this sounding in Storm Lab

The text

As transmitted.

183 
WGUS54 KOUN 220202
FFWOUN
OKC027-081-083-109-220400-
/O.NEW.KOUN.FF.W.0111.171022T0202Z-171022T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Norman OK
902 PM CDT SAT OCT 21 2017

The National Weather Service in Norman has issued a

* Flash Flood Warning for...
  Eastern Oklahoma County in central Oklahoma...
  Northwestern Lincoln County in central Oklahoma...
  North central Cleveland County in central Oklahoma...
  Southeastern Logan County in central Oklahoma...

* Until 1100 PM CDT
  
* At 901 PM CDT, Doppler radar indicated thunderstorms producing 
  very heavy rain across the warned area. One to two inches of rain 
  has already fallen. Flash flooding is occurring or is imminent, 
  particularly in urban areas.

* Some locations that will experience flooding include...
  Oklahoma City, eastern Edmond, Moore, Midwest City, Del City,
  Choctaw, Harrah, Spencer, Jones, Nicoma Park, Luther, Wellston,
  Valley Brook, Carney, Arcadia, Warwick, Fallis, Tinker Air Force
  Base, Stanley Draper Lake and Forest Park.

Additional rainfall amounts of one to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3528 9743 3544 9750 3543 9757 3578 9730
      3591 9677 3534 9728

$$

WR

1 follow-up statement

451 
WGUS74 KOUN 220346
FFSOUN

Flash Flood Statement
National Weather Service Norman OK
1046 PM CDT SAT OCT 21 2017

OKC027-081-083-109-220356-
/O.CAN.KOUN.FF.W.0111.000000T0000Z-171022T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Oklahoma OK-Lincoln OK-Cleveland OK-Logan OK-
1046 PM CDT SAT OCT 21 2017

...THE FLASH FLOOD WARNING FOR EASTERN OKLAHOMA...NORTHWESTERN
LINCOLN...NORTH CENTRAL CLEVELAND AND SOUTHEASTERN LOGAN COUNTIES IS
CANCELLED...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3528 9743 3544 9750 3543 9757 3578 9730
      3591 9677 3534 9728

$$

WR

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Oct 21, 6:51 PM CDT, 2 hours 11 minutes earlier.

Area forecast discussion, Oct 21, 6:51 PM CDT, 2 hours 11 minutes before

Area Forecast Discussion
National Weather Service Norman OK
651 PM CDT Sat Oct 21 2017

.DISCUSSION...

&&

.AVIATION...
Thunderstorms will move east beyond central, southwest, and north
central Oklahoma before 11 PM. Until then very large hail and
strong wind gusts are likely in some areas. Ceilings will lift
quickly into VFR category when the cold front passes shortly after
thunderstorms. Gusty north winds will subside by mid-day Sunday.

&&

.PREV DISCUSSION... /issued 210 PM CDT Sat Oct 21 2017/

DISCUSSION...
The cold front continues to progress southward this afternoon
across northwestern OK, with a few elevated showers quickly
lifting northeast ahead of it. Stratus is finally starting to mix
out over portions of western and central OK so expect
destabilization through late this afternoon. Initial storm
development should occur sometime around 5 PM along the front in
western and northwestern OK. A few discrete cells will be possible
over southwestern OK and western north TX, with the greatest
potential for a tornado or two near the Red River early this
evening. Otherwise, expect rapid linear merge into a squall line
extending from northern OK into southern and southwestern OK
around 9-10 PM. Wind damage will become a concern during that time
frame. The storms should exit our FA around 1-2 AM.

Tomorrow will be quiet with much cooler and drier air moving into
the Southern Plains. Skies will also clear. A brief warmup is
expected Monday, but another cold front will arrive Tue.
Precipitation is not expected with this front. Again, temperatures
will climb back to a few degrees above normal for Wed and Thu
before a strong cold front arrives overnight Thursday thru Fri.
Some snow will even be possible over northwestern OK Sat AM as a
deep trough sweeps across the central and northern CONUS. Highs on
Friday and Sat are expected to be 10 to 15 degrees below average.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  76  50  68  48 /  50 100   0   0
Hobart OK         79  46  70  47 /  70  90   0   0
Wichita Falls TX  83  50  71  48 /  30  90   0   0
Gage OK           76  40  71  46 /  20  10   0   0
Ponca City OK     77  47  69  46 /  80 100   0   0
Durant OK         80  56  71  48 /  20 100  10   0

&&

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

09/09/09

Hazardous weather outlook, Oct 21, 6:00 PM CDT, 3 hours 2 minutes before

Hazardous Weather Outlook
National Weather Service Norman OK
600 PM CDT Sat Oct 21 2017

OKZ004>048-050>052-TXZ083>090-221100-
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-
600 PM CDT Sat Oct 21 2017

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

.DAY ONE...Tonight...

.Thunderstorms...
There is an enhanced risk of severe thunderstorms across parts of
north central, central, and southern Oklahoma, and adjacent parts of
northern Texas. A slight and marginal risk cover much of the rest of
the area.

Location...
The enhanced risk is near and southeast of a line from
Enid to Clinton, Altus, and Seymour Texas. This includes places like
Ponca City, Enid, Lawton, Oklahoma City metro, Ada, Ardmore, and
Wichita Falls.

Impacts...
Damaging wind gusts to around 80 mph and large hail up to the size
of tennis balls are the primary hazards. There is a low potential
for tornadoes across parts of central and southern Oklahoma, and
adjacent parts of northern Texas.

Timing...
Severe thunderstorms will continue until 2 am.
The most likely time for tornadoes is until 9 PM.

Discussion...
Thunderstorms continue forming along a cold front moving southeast
across Oklahoma. Large hail is the main hazard until mid-evening
after which damaging winds will become the main hazard. Isolated
wind gusts up to 80 mph are possible.

The tornado potential, particularly in southwest Oklahoma, will
decrease late this evening.

.SPOTTER AND EMERGENCY MANAGEMENT STATEMENT...

Storm spotter groups and emergency management personnel across the
risk areas should prepare for severe weather operations late this
afternoon and tonight.

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

.Thunderstorms...
A few thunderstorms may linger in parts of southeast Oklahoma
Sunday morning before exiting the area.

.Cold/Frost...
Patchy frost and near freezing temperatures may be possible across
portions of Oklahoma late next week.

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, Oct 21, 8:36 PM CDT, 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
836 PM CDT SAT OCT 21 2017

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

0830 PM     HAIL             3 ENE TABLER            35.06N 97.78W
10/21/2017  E0.88 INCH       GRADY              OK   AMATEUR RADIO

&&

MAD

Local storm report, Oct 21, 8:47 PM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
847 PM CDT SAT OCT 21 2017

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

0830 PM     HAIL             BRIDGE CREEK            35.23N 97.72W
10/21/2017  E1.00 INCH       GRADY              OK   AMATEUR RADIO

&&

MAD

Local storm report, Oct 21, 8:50 PM CDT, 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
850 PM CDT SAT OCT 21 2017

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

0847 PM     HAIL             3 NW MOORE              35.36N 97.53W
10/21/2017  E1.00 INCH       CLEVELAND          OK   EMERGENCY MNGR

&&

MAD

Local storm report, Oct 21, 8:56 PM CDT, 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
856 PM CDT SAT OCT 21 2017

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

0854 PM     TSTM WND GST     1 E DUNCAN              34.50N 97.94W
10/21/2017  M58 MPH          STEPHENS           OK   AMATEUR RADIO

&&

MAD

Local storm report, Oct 21, 8:58 PM CDT, 4 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
858 PM CDT SAT OCT 21 2017

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

0855 PM     HAIL             1 NE DEL CITY           35.46N 97.43W
10/21/2017  E0.75 INCH       OKLAHOMA           OK   TRAINED SPOTTER

            JUST WEST OF SOONER ROAD AND JUST SOUTH OF
            RENO AVE.

&&

MAD

Local storm report, Oct 21, 9:02 PM CDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
902 PM CDT SAT OCT 21 2017

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

0845 PM     HAIL             3 W MOORE               35.35N 97.55W
10/21/2017  E1.00 INCH       CLEVELAND          OK   PUBLIC

            SOCIAL MEDIA.

&&

MAD

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 21, 7:09 PM CDT	Severe Thunderstorm Warning	OUN	Jackson, Tillman	36 min
Oct 21, 7:10 PM CDT	Tornado Warning	OUN	Caddo	35 min
Oct 21, 7:13 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Tillman	47 min
Oct 21, 7:22 PM CDT	Severe Thunderstorm Warning	OUN	Caddo, Canadian, Grady	38 min
Oct 21, 7:24 PM CDT	Severe Thunderstorm Warning	OUN	Caddo, Comanche, Grady	51 min
Oct 21, 7:27 PM CDT	Tornado Warning	OUN	Caddo, Grady	33 min
Oct 21, 7:34 PM CDT	Flash Flood Warning	OUN	Caddo	116 min
Oct 21, 7:39 PM CDT	Areal Flood Advisory	OUN	Caddo, Comanche	2 hr
Oct 21, 7:40 PM CDT	Special Weather Statement	OUN	Kay, Kingfisher, Logan, Noble	35 min
Oct 21, 7:53 PM CDT	Areal Flood Advisory	OUN	Caddo, Canadian, Grady, Kingfisher, Logan, Oklahoma and 1 more	3 hr
Oct 21, 7:55 PM CDT	Tornado Warning	OUN	Grady, McClain	35 min
Oct 21, 7:56 PM CDT	Severe Thunderstorm Warning	OUN	Canadian, Cleveland, Grady, Oklahoma	49 min
Oct 21, 7:59 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Tillman	46 min
Oct 21, 8:07 PM CDT	Special Weather Statement	OUN	Payne	23 min
Oct 21, 8:10 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Grady, McClain	50 min
Oct 21, 8:17 PM CDT	Areal Flood Warning	OUN	Caddo, Canadian, Grady	118 min
Oct 21, 8:20 PM CDT	Areal Flood Warning	OUN	Caddo, Canadian, Grady	115 min
Oct 21, 8:33 PM CDT	Special Weather Statement	OUN	Lincoln, Oklahoma, Payne	27 min
Oct 21, 8:33 PM CDT	Severe Thunderstorm Warning	OUN	Grady, Jefferson, Stephens	42 min
Oct 21, 8:36 PM CDT	Areal Flood Advisory	OUN	Lincoln, Logan, Noble, Payne	114 min
Oct 21, 8:37 PM CDT	Tornado Warning	OUN	Cleveland, McClain	23 min
Oct 21, 8:47 PM CDT	Areal Flood Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	3 hr
Oct 21, 8:48 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, McClain, Oklahoma	42 min
Oct 21, 8:49 PM CDT	Flash Flood Warning	OUN	Canadian, Cleveland, Grady, McClain, Oklahoma	116 min
Oct 21, 8:57 PM CDT	Severe Thunderstorm Warning	OUN	Cotton, Tillman	48 min
Oct 21, 9:04 PM CDT	Special Weather Statement	OUN	Lincoln, Payne	41 min
Oct 21, 9:10 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Grady, Stephens	50 min
Oct 21, 9:17 PM CDT	Areal Flood Advisory	OUN	Carter, Cleveland, Comanche, Cotton, Garvin, Grady and 10 more	118 min
Oct 21, 9:19 PM CDT	Severe Thunderstorm Warning	OUN	Cleveland, Lincoln, Oklahoma, Pottawatomie, Seminole	41 min
Oct 21, 9:34 PM CDT	Special Weather Statement	OUN	Jefferson	26 min
Oct 21, 9:38 PM CDT	Tornado Warning	OUN	Pottawatomie, Seminole	37 min
Oct 21, 9:52 PM CDT	Severe Thunderstorm Warning	OUN	Hughes, Lincoln, Pottawatomie, Seminole	38 min
Oct 21, 9:55 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, Pontotoc, Seminole	50 min
Oct 21, 10:10 PM CDT	Tornado Warning	OUN	Pontotoc	22 min
Oct 21, 10:39 PM CDT	Special Weather Statement	OUN	Carter, Johnston, Love, Marshall, Murray	36 min
Oct 21, 10:47 PM CDT	Special Weather Statement	OUN	Coal, Hughes	28 min
Oct 21, 10:52 PM CDT	Areal Flood Advisory	OUN	Coal, Garvin, Hughes, Murray, Pontotoc, Seminole	53 min
Oct 21, 11:47 PM CDT	Special Weather Statement	OUN	Bryan	28 min
Oct 21, 11:48 PM CDT	Special Weather Statement	OUN	Atoka	27 min
Oct 22, 9:53 AM CDT	River Flood Warning	OUN	Comanche, Cotton	56 hr

Nearby

Flash Flood Warnings in Oklahoma, 2017 Every flash flood 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; radar from the NEXRAD Level II archive.