Numerous unorganized showers and storms formed under the influence of southwest flow on the afternoon of the 7th. Heavy rain and training storms resulted in some flash flooding.
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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.
Numerous unorganized showers and storms formed under the influence of southwest flow on the afternoon of the 7th. Heavy rain and training storms resulted in some flash flooding.
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 7, 8:51 AM CST, 2 hours 14 minutes earlier.
Area Forecast Discussion National Weather Service Norman OK 951 AM CDT Fri Sep 7 2018 ...Update... && .DISCUSSION... We made a few generally minor updates based on trends this morning. Coincident with a weak baroclinic/convergence zone at 850 mb, and within modest upper diffluence from approaching shortwave and upper jet entrance region to the north, a band of rain with embedded heavy rainfall rates is oriented from north- central Oklahoma through central and southwest Oklahoma in to north Texas. We're quite anomalously moist still, with 12 UTC sounding from Norman and Lamont both showing 2.14 inches of precipitable water, and deep saturation from low LCL up through relatively high freezing height yielding 13,000-14,000 warm cloud depth. The PW values at Norman are about a tenth of an inch above the 15 day max moving average and sets a new daily maximum. This will support warm rain processes and enhanced rainfall rates beyond even what the 88Ds are showing, despite having them in Tropical Z-R this morning (per gauge comparison this morning). With a little more forcing for ascent today (still modest), and such a moist environment, we increased rain chances mainly along and east of ongoing band. Current thinking is that convective cells will increase to the east of the band across south-central Oklahoma up toward the I-44 corridor and become quite numerous later today. While the threat of heavier rain may shift steadily eastward today across mainly southern Oklahoma and portions of north Texas, decent coverage of lighter showers is still probable across a large portion of the area given position of broad/weak trough and attendant upper jet entrance region. Most CAMs seem to represent this situation fairly well, with some variance. HRRR may be too quick to shift the bulk of the convection east, and RAP may be too aggressive with heavier amounts back to the west and north. ARW and NMMb seem to be the most representative of the synoptic and mesoscale environment at this time. We'll monitor trends on the mesoscale late this morning and consider the possibility of a focused Flood Watch through early evening again. BRB && .PREV DISCUSSION... /issued 621 AM CDT Fri Sep 7 2018/ DISCUSSION... The 12Z aviation forecast discussion follows.... AVIATION... A very moist atmosphere remains over Oklahoma and north Texas this morning, and minimal changes are expected through tomorrow morning. Some diurnal improvement in ceilings is expected later this morning, followed by deterioration in the evening/overnight. Rain this morning should drift slowly east and decrease, but diurnal effects will cause the number of showers/thunderstorms to increase again late this morning and this afternoon. Ceilings, visibilities, and precipitation intensities generally will be highly varied over short distances through at least this evening. CmS PREV DISCUSSION... /issued 429 AM CDT Fri Sep 7 2018/ DISCUSSION... Showers continue to develop along a baroclinic zone around 925 mb early this morning from HBR to just west of PNC. Expect this trend to continue through most of the morning with a slow shift to the south and east. Isentropic descent will then develop by late this morning but later this afternoon a mid to upper level shortwave trough should provide sufficient lift for widely scattered showers and thunderstorms to redevelop, especially over central and northern OK. After tomorrow, precipitation chances will decrease as mid level moisture and ascent shift eastward with the aforementioned trough. Even with rain chances decreasing Sun, temps should remain below avg thanks to subtle CAA and lingering stratus. The latter will be most evident over eastern and northeastern for at least the first part of the day. Max temps may stay in the mid 70s along and east of I-35. A slow warming trend is then expected to start next week but will still remain below avg through at least Tue with northwesterly flow aloft remaining present and the upper ridge to our WSW. After Wed, it's questionable how dominate the ridge will become over the central CONUS but temps should start to nudge to near avg by this time with drier BL conditions present. && .PRELIMINARY POINT TEMPS/POPS... Oklahoma City OK 77 69 76 63 / 90 30 20 10 Hobart OK 78 69 79 63 / 70 30 20 0 Wichita Falls TX 79 71 80 66 / 80 40 30 10 Gage OK 76 64 76 60 / 20 20 20 0 Ponca City OK 78 67 75 60 / 80 30 20 10 Durant OK 84 72 79 66 / 80 50 40 20 && .OUN WATCHES/WARNINGS/ADVISORIES... OK...None. TX...None. && 26/12
Hazardous Weather Outlook National Weather Service Norman OK 842 AM CDT Fri Sep 7 2018 OKZ004>048-050>052-TXZ083>090-081345- 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- 842 AM CDT Fri Sep 7 2018 This hazardous weather outlook is for portions of northern... western...central...and southern Oklahoma...and western north Texas. .DAY ONE...Today and Tonight... .Thunderstorms... Isolated thunderstorms are possible through tonight. Severe storms are not expected. .Heavy Rain and Flooding... Rain showers will occasionally be heavy today resulting in some areas of flooding or flash flooding. The greatest flooding threat will be across central and southern Oklahoma, and western north Texas. .DAYS TWO THROUGH SEVEN...Saturday through Thursday... .Thunderstorms... A few thunderstorms will continue across portions of the area through Saturday. Severe storms are not expected. .Heavy Rain and Flooding... Locally heavy rainfall amounts are expected with heavy rain showers and thunderstorms through Saturday. Excessive rainfall may lead to flooding or flash flooding. Get graphics and more details at weather.gov/norman...and follow our weather forecast office on Twitter and Facebook.
The Altus AFB radar (KFDR), 95 km away, was scanning. The volume nearest the first event began at 17:06 UTC.
1 flash flood, 1 flood. Local standard time, as filed.
Flowing water up to the wheel wells of cars on 11th street near Beech Ave and also near Willow Ave.
Water reported up to tops of tires at the intersection of 39th and Portland. Radar precipitation estimates in the area were less than half an inch.
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: 786606, 786607.