Abundant moisture from the gulf and a remnant tropical system converged with a front coming in from northwest early on the morning of the 21st resulting in widespread heavy rain and numerous reports of flash flooding across central and south central Oklahoma and western north Texas through the day.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS OUN wrote it up.
Abundant moisture from the gulf and a remnant tropical system converged with a front coming in from northwest early on the morning of the 21st resulting in widespread heavy rain and numerous reports of flash flooding across central and south central Oklahoma and western north Texas through the day.
The local office's own words before the first event, 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 the first event at Sep 21, 5:08 AM CST, 1 hour 52 minutes earlier.
Area Forecast Discussion
National Weather Service Norman OK
608 AM CDT Fri Sep 21 2018
.DISCUSSION...
&&
.AVIATION...
For the 12z TAFs:
Periods of rain, occasionally heavy with visibility reductions
temporarily as low as 2 to 3 SM will occur at most TAF sites.
Gradual decrease in heavy rain potential will occur at most TAF
sites by later today. Thunderstorms are possible with occasional
lightning, but for most sites we handled this with VCTS. MVFR
ceilings should prevail through the TAF period except in northern
Oklahoma where a return to VFR is likely by late afternoon or
evening.
&&
.PREV DISCUSSION... /issued 353 AM CDT Fri Sep 21 2018/
DISCUSSION...
Heavy rainfall event continues to unfold with approaching cold
front, combined with phasing of northern/central plains s/wv trough
and weakening remnants of weak tropical disturbance. Greatest
influence of tropical moisture will remain confined to far southern
portions of Oklahoma and northern Texas late today through tomorrow
given delayed lower level return and advected layered precipitable
water trends. Highest QPF values are expected south of the OKC
metro, down toward Ardmore, Ada, and Durant and primarily from late
this afternoon through Saturday morning. Rainfall totals of 5 to 8
inches certainly appear possible over these areas. With heavier
precipitation ending across western parts of Oklahoma by evening, we
will move the expiration of the Flood Watch up to 00Z this evening
across the western-third or so of Oklahoma. Will keep rest of watch
going and let later shifts adjust as needed. 00Z NAM and last couple
runs of the ECM slow progression of southern wave over northern
Texas, allowing for heavy rainfall to potential last into much of
Saturday across the Red River Valley. Higher probabilities will be
maintained through the day.
In addition to the widespread rainfall, much cooler air will spread
into the region today and tonight. Below average temperatures will
be forecast through the weekend, with temperatures moderating on
Monday ahead of next frontal boundary. An evolving central U.S.
trough will be reflected at surface with passage of cold front on
Tuesday. Along with a downward trend in temperatures, rain chances
will return with this frontal boundary Tuesday into Wednesday. A
more clipper type system progd to dive into the northern plains
Wednesday into Thursday, allowing yet another front to move in late
in the week. This front has the potential to usher in the driest air
we have seen in quite some time, with dewpoints likely to fall into
the 40s over a larger area than currently forecast. With moisture
less abundant by this time, chances for showers and storms appears
lower and will keep pops at or below guidance values.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 75 59 71 60 / 100 90 40 20
Hobart OK 73 59 73 59 / 100 50 20 10
Wichita Falls TX 77 61 70 62 / 100 90 70 30
Gage OK 71 50 75 54 / 80 0 0 10
Ponca City OK 74 55 76 58 / 90 20 10 10
Durant OK 80 67 71 64 / 100 100 90 60
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch through Saturday afternoon for OKZ018>020-023>032-
037>048-050>052.
Flood Watch through this evening for OKZ014>017-021-022-033>036.
TX...Flood Watch through Saturday afternoon for TXZ084>090.
Flood Watch through this evening for TXZ083.
&&
12/11Hazardous Weather Outlook National Weather Service Norman OK 459 AM CDT Fri Sep 21 2018 OKZ004>048-050>052-TXZ083>090-221000- 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- 459 AM CDT Fri Sep 21 2018 This hazardous weather outlook is for portions of northern... western...central...and southern Oklahoma...and western north Texas. .DAY ONE...Today and Tonight... .Heavy Rainfall and Flooding... Periods of rain will be heavy at times and this could cause flooding of low-lying and poorly drained areas. The greatest chance of flooding or flash flooding will be over the southern half of Oklahoma and north Texas. .Thunderstorms... A few thunderstorms are possible today. Severe storms are not expected. .DAYS TWO THROUGH SEVEN...Saturday through Thursday... .Heavy Rainfall and Flooding... Heavy rain chances will continue through Saturday across southern Oklahoma and north Texas. This could cause flooding of low-lying and poorly drained areas. .Thunderstorms... A few thunderstorms are possible Saturday, mainly across southern Oklahoma and north Texas. Low chances of storms will return Monday and continue through next week. Severe storms are not expected. Get graphics and more details at weather.gov/norman...and follow our weather forecast office on Twitter and Facebook.
The Norman radar (KTLX), 131 km away, was scanning. The volume nearest the first event began at 12:58 UTC.
34 flash flood. Local standard time, as filed.
Eight inches of water was over roadway at intersections of Wiley Rd and Old Cabin Rd.
Roadways reported under water.
Flash flooding reported over Highway 270.
A house was flooded.
Water well over roadway at intersections of S. Gregory Rd and SW 29th st.
Eight inches of water reported over the roadway on east Pontotoc Road.
USGS gage on Honey Creek measured flood wave with water one foot over roadway in Turner Falls state park.
Significant water reported over roadway.
Significant water over the road at Cherokee trading post.
Six to twelve inches of water over the roads around parts of town.
USGS river gauge site reporting 3 feet of water over roadway at entrance to the park.
High water on road reported on Broadway between 15th and 33rd.
High water on road near University of Central Oklahoma.
High water on roads at 15th st and Kelly Ave.
Car stalled/stuck in high water. Road impassable.
Flowing water over the roadway.
Highway 377 was closed from highway 7 north to Fittstown.
Water was up to the foundation of several homes in Davis.
Highway 77 south of Davis to I-35 has been shutdown by ODOT.
Southwest 15th between Mustang and Sara Road was impassable.
Curb flooding and road closures near Hammond avenue.
Water rescues from vehicles were reported in Stonewall.
Memorial road was closed at Henney road due to flood damage and reported sink hole.
Road closures due to high water at Mobil road and Airport road in Healdton.
Road closure due to high water at Cargo road east of Ratliff city.
Harris Ranch road closed due to being under water.
Roads washed out near the intersection of 3615 and 1630.
Flood waters are entering homes at the intersection of 1st and county road 3640.
Water rescue performed at Chandler creek at the intersection of Cherry road and Madische road.
County road 1670 washed out west of the county road 3590 intersection.
Road partially washed out by flood waters.
Oil city road and Radar road near Healdton were closed due to flash flooding.
Wingate road, Delta road, Inwood road, Samedan road, Longview road, Cargo road, and |Mobil roads in or near Ratliff city were closed due to flash flooding.
Water rescue was completed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oklahoma in 2018Every state in 2018This day in weather historyWarnings in Oklahoma, September 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 784393, 784396, 784398, 784401, 784402, 784404, 784411, 784412, 784413, 784415, 784417, 784418, 784419, 786572, 786573, 786574, 786575, 786576, 786578, 786580, 786581, 786582, 786583, 786584, 786585, 786586, 786589, 786590, 786591, 786592, 786593, 786595, 786597, 786598.