Alert archive / Oklahoma / Special Weather Statements in 2021
Special Weather Statement, NWS Norman, OK
NWS Norman, OK issued this special weather statement at May 17, 2021, 11:29 PM CDT for Ellis County, Harper County, Roger Mills County, Oklahoma. It was in force for 46 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
- May 17, 2021, 11:29 PM CDT (04:29 UTC)
- Expired
- May 18, 2021, 12:15 AM CDT
- In force
- 46 min
- Issued by
- NWS Norman, OK
Counties Ellis County, OK, Harper County, OK, Roger Mills County, OK
The radar
The Vance AFB radar (KVNX), 155 km from the middle of the area, began a volume at 04:29 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
Dodge City, (KDDC), launched 00:00Z, 4.5 hours before the alert went out and 168 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.
- Mixed-layer CAPE
- 456 J/kg
- Mixed-layer CIN
- -9 J/kg
- Mixed-layer LCL
- 1128 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 34 m²/s²
- 0-3 km storm-relative helicity
- 113 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.2
The text
As transmitted.
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</html>What forecasters said that day
The local office's own words before this special weather statement 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 special weather statement went out at May 17, 6:04 PM CDT, 5 hours 25 minutes earlier.
Area forecast discussion, May 17, 6:04 PM CDT, 5 hours 25 minutes before
Area Forecast Discussion
National Weather Service Norman OK
604 PM CDT Mon May 17 2021
...New AVIATION...
.SHORT TERM...
(This evening through Tuesday)
Issued at 203 PM CDT Mon May 17 2021
Severe thunderstorms are expected to develop near a dry line in
eastern NM this afternoon and move east across the TX panhandle
toward the northern part of TX and southwestern OK by early evening.
Apart from the main severe hazard of large hail, the rest of tonight
and Tuesday will be dominated by heavy rainfall. The upper low over
western NM is forecast to move very slow to northeastern NM by
Tuesday evening. The abnormally moist air mass over the southern
plains will remain in place with a few periods of showers and rain
affecting southern and much of central Oklahoma beyond the daytime
Tuesday. The flood watch continues and we will add all of our
counties in northern Texas to the watch.
&&
.LONG TERM...
(Tuesday night through next Sunday)
Issued at 217 PM CDT Mon May 17 2021
Multiple rounds of showers and storms are likely throughout the
week and into parts of the weekend. On Wednesday morning, showers
and storms could be ongoing as the base of an mid-level closed low
moves into the Southern Plains. As this closed low moves through
the area, weak southerly flow will persist until the next mid-
level wave moves into the the West Coast this weekend. Moderate
850 mb flow atop low to mid 60s surface dewpoints should favor
continuous precipitation chances throughout the long term.
Elevated instability appears to be in place across much of the
area through the long term, so thunderstorms are possible with any
precipitating activity. Deep-layer shear is forecasted to be
weak, so any organized severe storms do not appear likely at this
time. Subsequent forecasts and changes in the models could build
confidence with the potential for organized severe storms.
The flooding potential exists across most of the area; especially
south-central, southeastern OK, and western north TX, where
multiple inches of precipitation have already fallen (and are
forecasted to fall) before the long term period begins.
Precipitable water values are supposed to stay between 1.5-1.75
inches through the remainder of the week, which is much higher
than sounding climatology for this time of year. Any additional
heavy rainfall could pose a threat of flash flooding and prolonged
periods of flooding.
Southerly surface flow should persist through the period, which
will keep high temperatures in the mid to upper 70s into the lower
80s. In addition, mostly cloudy skies should help to keep the low
temperatures in the low to mid 60s.
Bunker
&&
.AVIATION...
(00Z TAFS)
Issued at 559 PM CDT Mon May 17 2021
Storms are likely to form early this evening and continue into
the overnight hours, affecting all TAF sites. IFR and MVFR
conditions are expected to develop with the precipitation and
continue into the morning. Winds should veer from easterly to more
southerly towards the morning hours. Periods of light rain are
possible for some sites.
&&
.UPPER AIR...
Issued at 203 PM CDT Mon May 17 2021
An Upper Air flight is planned for May 18 0000Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 62 74 62 76 / 80 70 80 50
Hobart OK 60 75 60 79 / 80 60 60 40
Wichita Falls TX 64 76 63 79 / 80 70 60 50
Gage OK 57 76 56 77 / 60 60 60 40
Ponca City OK 61 76 62 77 / 60 70 90 70
Durant OK 65 76 64 76 / 70 80 90 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch through Wednesday morning for OKZ019-020-022>032-
034>048-050>052.
TX...Flood Watch through Wednesday morning for TXZ083>090.
&&
SHORT TERM...09
LONG TERM....13
AVIATION...13Hazardous weather outlook, May 17, 10:43 PM CDT, 46 minutes before
Hazardous Weather Outlook...UPDATED National Weather Service Norman OK 1043 PM CDT Mon May 17 2021 OKZ004>048-050>052-TXZ083>090-190345- 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- 1043 PM CDT Mon May 17 2021 This hazardous weather outlook is for portions of northern... western...central...and southern Oklahoma...and western north Texas. .DAY ONE...Through Tonight... .Thunderstorms... A few strong to severe thunderstorms will remain possible thru late tonight, mainly across portions of northwestern and southwestern Oklahoma, and western north Texas. Hail up to the size of quarters and wind gusts up 60 mph will be possible. .Heavy Rainfall... Localized flooding could occur across portions of southern Oklahoma thru tonight. .DAYS TWO THROUGH SEVEN...Tuesday through Sunday... .Thunderstorms... Thunderstorm chances will continue thru Saturday. A few severe thunderstorms will be possible Tuesday afternoon and evening mainly across portions of eastern and southeastern Oklahoma. Hail up to the size of golf balls and damaging wind gusts up to 60 mph will be possible. Strong to severe storms will again be possible across western Oklahoma and western north Texas Wednesday afternoon and evening. .Heavy Rainfall... Areas of flooding will be possible mainly along and south of Interstate 44 thru at least Wednesday. 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, May 17, 7:46 PM CDT, 3 hours 43 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
746 PM CDT MON MAY 17 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0741 PM HAIL 1 NE GOREE 33.48N 99.51W
05/17/2021 E1.25 INCH KNOX TX TRAINED SPOTTER
&&
RCBSpecial weather statement, May 17, 10:03 PM CDT, 1 hour 26 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1003 PM CDT Mon May 17 2021
OKZ034>037-TXZ085-180330-
Kiowa OK-Tillman OK-Greer OK-Jackson OK-Wilbarger TX-
1003 PM CDT Mon May 17 2021
...SIGNIFICANT WEATHER ADVISORY FOR southwestern Kiowa...northwestern
Tillman...southeastern Greer...Jackson and north central Wilbarger
Counties Until 1030 PM CDT...
AT 959 PM CDT, non-thunderstorm winds of about 40-50 mph are possible
for the next one to two hours.
HAZARDS INCLUDE...
Wind gusts up to 50 MPH...
LAT...LON 3436 9922 3442 9944 3446 9960 3474 9944
3485 9937 3493 9911 3466 9898 3456 9911
TIME...MOT...LOC 0259Z 240DEG 16KT 3468 9918
JTSpecial weather statement, May 17, 10:29 PM CDT, 1 hour before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1029 PM CDT Mon May 17 2021
OKZ033-036-TXZ083-180400-
Harmon OK-Jackson OK-Hardeman TX-
1029 PM CDT Mon May 17 2021
...SIGNIFICANT WEATHER ADVISORY FOR Harmon...southwestern Jackson and
northwestern Hardeman Counties Until 1100 PM CDT...
AT 1027 PM CDT, a strong thunderstorm was located 6 miles northwest
of Childress, moving east at 35 MPH.
HAZARDS INCLUDE...
Wind gusts to 50 MPH...
LAT...LON 3484 10000 3485 9999 3485 9973 3434 9972
3435 10000
TIME...MOT...LOC 0327Z 268DEG 30KT 3451 10032
JTSpecial weather statement, May 17, 11:12 PM CDT, 17 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1112 PM CDT Mon May 17 2021
OKZ033-036-TXZ083-085-180445-
Harmon OK-Jackson OK-Wilbarger TX-Hardeman TX-
1112 PM CDT Mon May 17 2021
...SIGNIFICANT WEATHER ADVISORY FOR southeastern Harmon...
southwestern Jackson...northwestern Wilbarger and central Hardeman
Counties Until 1145 PM CDT...
AT 1109 PM CDT, the leading edge of strong and gusty thunderstorm
winds extended near Eldorado, moving east at 35 MPH.
HAZARDS INCLUDE...
Wind gusts to 50 MPH...
LAT...LON 3428 9988 3473 9988 3471 9948 3457 9932
3426 9931
TIME...MOT...LOC 0409Z 268DEG 32KT 3443 9961
JTSpecial weather statement, May 17, 11:19 PM CDT, 10 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
1119 PM CDT Mon May 17 2021
OKZ035>037-180500-
Kiowa OK-Tillman OK-Jackson OK-
1119 PM CDT Mon May 17 2021
...SIGNIFICANT WEATHER ADVISORY FOR southern Kiowa...Tillman and east
central Jackson Counties Until midnight CDT...
AT 1116 PM CDT, non-thunderstorm winds of 40 to 50 mph are possible.
HAZARDS INCLUDE...
Wind gusts to 50 MPH...
LAT...LON 3464 9920 3463 9895 3459 9887 3452 9883
3451 9883 3451 9881 3438 9873 3416 9879
3420 9894 3421 9895 3421 9897 3422 9899
3423 9904 3437 9919
TIME...MOT...LOC 0416Z 268DEG 32KT 3432 9888
JTSpecial weather statement, May 17, 11:29 PM CDT, 0 minutes before
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE Norman OK 1129 PM CDT Mon May 17 2021 OKZ004-009-010-014>016-021-180515- Woodward OK-Roger Mills OK-Dewey OK-Harper OK-Beckham OK-Custer OK- Ellis OK- 1129 PM CDT Mon May 17 2021 ...SIGNIFICANT WEATHER ADVISORY FOR southwestern Woodward...Roger Mills...western Dewey...southwestern Harper...northwestern Beckham... northwestern Custer and Ellis Counties Until 1215 AM CDT... AT 1127 PM CDT, strong thunderstorms were along a line extending from 7 miles north of Higgins to 7 miles north of Sweetwater, moving northeast at 50 MPH. HAZARDS INCLUDE... Hail up to one-half inch diameter... Wind gusts to 50 MPH... LAT...LON 3671 10001 3689 9950 3568 9928 3531 10000 TIME...MOT...LOC 0427Z 233DEG 45KT 3623 10004 3553 9990 JT
The office that day
Everything else NWS Norman, OK issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 17, 10:03 PM CDT | Special Weather Statement | OUN | Jackson | 27 min |
| May 17, 10:29 PM CDT | Special Weather Statement | OUN | Harmon | 31 min |
| May 17, 10:42 PM CDT | Severe Thunderstorm Warning | OUN | Harmon, Jackson | 33 min |
| May 17, 11:12 PM CDT | Special Weather Statement | OUN | Jackson | 33 min |
| May 17, 11:19 PM CDT | Special Weather Statement | OUN | Tillman | 41 min |
| May 17, 11:43 PM CDT | Severe Thunderstorm Warning | OUN | Ellis, Woodward | 32 min |
| May 18, 12:19 AM CDT | Special Weather Statement | OUN | Woodward | 56 min |
| May 18, 12:21 AM CDT | Special Weather Statement | OUN | Roger Mills | 24 min |
| May 18, 12:44 AM CDT | Special Weather Statement | OUN | Washita | 61 min |
| May 18, 1:02 AM CDT | Special Weather Statement | OUN | Woodward | 58 min |
| May 18, 1:03 AM CDT | Special Weather Statement | OUN | Dewey | 57 min |
| May 18, 1:06 AM CDT | Special Weather Statement | OUN | Jefferson | 24 min |
| May 18, 1:28 AM CDT | Special Weather Statement | OUN | Major | 47 min |
| May 18, 2:00 AM CDT | Special Weather Statement | OUN | Comanche, Kiowa, Tillman | 30 min |
| May 18, 2:35 AM CDT | Special Weather Statement | OUN | Comanche, Cotton, Tillman | 55 min |
| May 18, 2:48 AM CDT | Special Weather Statement | OUN | Kingfisher | 42 min |
| May 18, 2:56 AM CDT | Special Weather Statement | OUN | Garfield | 49 min |
| May 18, 3:36 AM CDT | Special Weather Statement | OUN | Kingfisher | 39 min |
| May 18, 12:03 PM CDT | Special Weather Statement | OUN | Noble | 27 min |
| May 18, 4:14 PM CDT | Special Weather Statement | OUN | Alfalfa | 31 min |
| May 18, 4:44 PM CDT | Special Weather Statement | OUN | Garfield | 46 min |
| May 17, 7:00 PM CDT | Severe Thunderstorm Warning | OUN | Baylor, Knox | 45 min |
| May 17, 7:11 PM CDT | Special Weather Statement | OUN | Wilbarger | 34 min |
| May 17, 7:22 PM CDT | Areal Flood Advisory | OUN | Knox | 3 hr |
| May 17, 7:33 PM CDT | Severe Thunderstorm Warning | OUN | Baylor, Knox | 42 min |
| May 17, 8:00 PM CDT | Severe Thunderstorm Warning | OUN | Archer, Baylor, Wichita | 45 min |
| May 17, 8:17 PM CDT | Severe Thunderstorm Warning | OUN | Archer, Wichita | 23 min |
| May 17, 8:19 PM CDT | Areal Flood Advisory | OUN | Baylor | 3 hr |
| May 17, 8:33 PM CDT | Areal Flood Advisory | OUN | Archer | 3 hr |
| May 17, 9:28 PM CDT | Areal Flood Advisory | OUN | Wichita | 3 hr |
Nearby
Special Weather Statements in Oklahoma, 2021Every special weather statement 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.