Alert archive / Oklahoma / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 587, NWS Norman, OK

July 30, 20205 counties in Oklahoma

NWS Norman, OK issued this severe thunderstorm warning at Jul 30, 2020, 4:38 AM CDT for 5 counties in Oklahoma. It was in force for 37 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: Jul 30, 2020, 4:38 AM CDT (09:38 UTC)
Expired: Jul 30, 2020, 5:15 AM CDT
In force: 37 min
Issued by: NWS Norman, OK
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Alfalfa County, OK, Blaine County, OK, Garfield County, OK, Kingfisher County, OK, Major County, OK

The radar

The Vance AFB radar (KVNX), 55 km from the middle of the area, began a volume at 09:41 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

Norman, OK (KOUN), launched 00:00Z, 9.6 hours before the alert went out and 135 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: 1768 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 1314 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 195 m²/s²
0-3 km storm-relative helicity: 202 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.4

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 Jul 30, 3:38 AM CDT, 1 hour earlier.

Area forecast discussion, Jul 30, 3:38 AM CDT, 1 hour before

Area Forecast Discussion
National Weather Service Norman OK
338 AM CDT Thu Jul 30 2020

...New SHORT TERM...

.SHORT TERM...
(Today and tonight)
Issued at 337 AM CDT Thu Jul 30 2020

Main concern in the short term is a storm complex coming off the
high plains of western Kansas into northwest Oklahoma.  With DCAPE
values of 1000-1200 J/kg and MUCAPE up to 3000 J/kg, could certainly
see some of these cells producing severe wind gusts and marginal
severe hail. Expecting the northwest flow aloft steering this
complex to keep it up in northern Oklahoma for the next couple of
hours. The HRRR seems to have a good handle on this system with
collapsing it shortly after sunrise.  For this afternoon, a lee cold
front coming off Kansas will begin to push in.  Most of the CAMs
solutions break out late afternoon convection along the frontal
boundary, ranging from isolated cells to linear, so keeping POPs in
the forecast through the afternoon.

Later tonight, expecting the frontal boundary to be in place across
southern Oklahoma as northwest flow aloft brings in another
shortwave disturbance. Expecting numerous storms to breaks this
evening and overnight across portions of southwest, central, and
into northcentral Oklahoma as well as western north Texas. A
Marginal risk for severe storms is in place for later tonight, with
hail & winds as the main hazards. Although some of these storms
could produce heavy rain, high PW values that we have seen over the
last couple of days will have shifted well to our east, keeping the
widespread excessive rain and flooding potential much lower.

&&

.LONG TERM...
(Thursday night through next Tuesday)
Issued at 213 PM CDT Wed Jul 29 2020

Showers and thunderstorms will continue overnight Thursday night,
ending west to east on Friday as a upper level trough and associated
front make their way southeast across the central and southern
plains.

Cooler, drier air will lag behind Thursday's front keeping
temperatures below normal well into next week and limiting rain
chances over the weekend.

Both deterministic and ensemble models suggest the possibility of an
MCS Sunday night into Monday morning. Raised PoPs well above
initialized guidance (which tends to under perform with MCS's)
through this period.

Ensemble cluster analysis continues to show midweek as the most
likely time for a pattern change with the upper high building back,
though there is still a significant amount of variance among
ensemble members.

Day

&&

.AVIATION...
(06Z TAFS)
Issued at 1038 PM CDT Wed Jul 29 2020

Generally, VFR weather is expected. Thunderstorms in northern
Oklahoma are expected to dissipate before sunrise Thursday.
Otherwise, a front from the north on Thursday afternoon will bring
scattered showers and thunderstorms to the northern half of
Oklahoma.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  92  69  80  65 /  50  60  30  10
Hobart OK         96  68  85  64 /  50  60  30  10
Wichita Falls TX 100  70  87  66 /  30  60  30  10
Gage OK           90  63  84  60 /  30  60  20  10
Ponca City OK     87  68  80  63 /  60  60  30   0
Durant OK         98  71  87  67 /  20  60  60  10

&&

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

SHORT TERM...68
LONG TERM....14
AVIATION...09

Hazardous weather outlook, Jul 29, 9:42 PM CDT, 6 hours 56 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Norman OK
942 PM CDT Wed Jul 29 2020

OKZ004>048-050>052-TXZ083>090-301130-
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-
942 PM CDT Wed Jul 29 2020

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

.DAY ONE...Through tonight...

.Thunderstorms...
There is a risk of strong to severe thunderstorms across the
northern third of Oklahoma. The stronger storms will produce
wind gusts near 60 mph and locally heavy rainfall. Some hail is
also possible. The most likely time for severe storms will be from
the mid evening through about 2 am.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday...

.Thunderstorms...
Thunderstorm chances will continue through late Friday with the
highest chances Thursday night into Friday morning. Strong to
severe storms will be possible Thursday afternoon into the
overnight hours Thursday night, with damaging winds, large hail
and locally heavy rain the main concerns. Most of Saturday and
Sunday will be dry, but thunderstorm chances will increase Sunday
night through Monday morning.

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

In the hours before

Special weather statement, Jul 30, 1:53 AM CDT, 2 hours 45 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
153 AM CDT Thu Jul 30 2020

OKZ020-026-300730-
Payne OK-Lincoln OK-
153 AM CDT Thu Jul 30 2020

...SIGNIFICANT WEATHER ADVISORY FOR Payne and northeastern Lincoln
Counties Until 230 AM CDT...

AT 147 AM CDT, the leading edge of strong thunderstorms was located
along a line extending from near Oilton to near Cushing, with
additional thunderstorms extending back to southwest of
Stillwater. There storms are moving east at 45 MPH.

HAZARDS INCLUDE...
Wind gusts to 50 MPH...

LAT...LON 3596 9719 3615 9723 3614 9662 3587 9662
TIME...MOT...LOC 0647Z 276DEG 39KT 3608 9663 3598 9672

..speg.

Special weather statement, Jul 30, 2:37 AM CDT, 2 hours 1 minute before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
237 AM CDT Thu Jul 30 2020

OKZ004-300815-
Harper OK-
237 AM CDT Thu Jul 30 2020

...SIGNIFICANT WEATHER ADVISORY FOR northwestern Harper County Until
315 AM CDT...

AT 235 AM CDT, a strong thunderstorm was located 7 miles northeast of
Gate, moving east at 20 MPH.

HAZARDS INCLUDE...
Hail up to the size of nickels...
Wind gusts to 50 MPH...

LAT...LON 3700 9953 3679 9955 3681 10000 3700 10000
TIME...MOT...LOC 0735Z 270DEG 19KT 3693 9997

..speg.

Special weather statement, Jul 30, 3:18 AM CDT, 1 hour 20 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
318 AM CDT Thu Jul 30 2020

OKZ004-005-010-300845-
Woodward OK-Harper OK-Woods OK-
318 AM CDT Thu Jul 30 2020

...SIGNIFICANT WEATHER ADVISORY FOR north central Woodward...Harper
and northern Woods Counties Until 345 AM CDT...

AT 317 AM CDT, strong thunderstorms were along a line extending from
10 miles south of Buttermilk to near Laverne, moving east at 50 MPH.

HAZARDS INCLUDE...
Hail up to one-half inch diameter...
Wind gusts to 50 MPH...

LAT...LON 3699 9856 3662 9932 3665 10000 3700 10000
TIME...MOT...LOC 0817Z 273DEG 42KT 3696 9932 3674 9988

..speg.

Special weather statement, Jul 30, 3:57 AM CDT, 41 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
357 AM CDT Thu Jul 30 2020

OKZ005>007-012-300930-
Garfield OK-Alfalfa OK-Woods OK-Grant OK-
357 AM CDT Thu Jul 30 2020

...SIGNIFICANT WEATHER ADVISORY FOR northwestern Garfield...
Alfalfa...Woods and Grant Counties Until 430 AM CDT...

AT 353 AM CDT, the leading edge of strong and gusty thunderstorm
winds extended along a line extending from near Manchester to 7
miles east of Waynoka, moving east at 60 MPH. The strong winds will
approach before the thunderstorms themselves.

HAZARDS INCLUDE...
Wind gusts to 50 MPH...

LAT...LON 3700 9746 3675 9746 3651 9788 3656 9895
      3700 9930
TIME...MOT...LOC 0853Z 273DEG 52KT 3694 9803 3657 9875

..speg.

Local storm report, Jul 30, 4:14 AM CDT, 24 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE NORMAN OK
414 AM CDT THU JUL 30 2020

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

0405 AM     TSTM WND GST     1 SSW CHEROKEE          36.74N 98.36W
07/30/2020  M57 MPH          ALFALFA            OK   MESONET

&&

JPIKE

Local storm report, Jul 30, 4:35 AM CDT, 3 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 8:49 PM CDT	Special Weather Statement	OUN	Harper	26 min
Jul 29, 9:15 PM CDT	Special Weather Statement	OUN	Harper	30 min
Jul 29, 9:45 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Woods, Woodward	45 min
Jul 29, 10:23 PM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Woods	36 min
Jul 29, 10:36 PM CDT	Special Weather Statement	OUN	Alfalfa	24 min
Jul 29, 11:51 PM CDT	Special Weather Statement	OUN	Grant, Kay, Noble	24 min
Jul 30, 12:15 AM CDT	Special Weather Statement	OUN	Kay, Noble	30 min
Jul 30, 1:53 AM CDT	Special Weather Statement	OUN	Payne	37 min
Jul 30, 2:37 AM CDT	Special Weather Statement	OUN	Harper	38 min
Jul 30, 3:18 AM CDT	Special Weather Statement	OUN	Harper	27 min
Jul 30, 3:57 AM CDT	Special Weather Statement	OUN	Alfalfa, Grant, Woods	33 min
Jul 30, 4:14 AM CDT	Severe Thunderstorm Warning	OUN	Alfalfa, Garfield, Grant	46 min
Jul 30, 4:56 AM CDT	Severe Thunderstorm Warning	OUN	Garfield, Grant, Kay, Kingfisher, Logan, Noble and 1 more	49 min
Jul 30, 5:46 AM CDT	Special Weather Statement	OUN	Lincoln, Logan, Oklahoma, Payne	29 min
Jul 30, 6:15 AM CDT	Special Weather Statement	OUN	Lincoln, Oklahoma	30 min
Jul 30, 6:48 AM CDT	Areal Flood Advisory	OUN	Kay	3 hr
Jul 30, 3:23 PM CDT	Special Weather Statement	OUN	Washita	22 min
Jul 30, 4:18 PM CDT	Special Weather Statement	OUN	Kiowa	27 min
Jul 30, 4:22 PM CDT	Severe Thunderstorm Warning	OUN	Greer, Jackson, Kiowa	23 min
Jul 30, 4:28 PM CDT	Severe Thunderstorm Warning	OUN	Kiowa	17 min
Jul 30, 4:43 PM CDT	Special Weather Statement	OUN	Hughes	17 min
Jul 30, 4:48 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Greer, Jackson, Kiowa, Tillman	42 min
Jul 30, 4:51 PM CDT	Special Weather Statement	OUN	Grady	24 min
Jul 30, 5:00 PM CDT	Special Weather Statement	OUN	Tillman	15 min
Jul 30, 5:03 PM CDT	Special Weather Statement	OUN	Coal	27 min
Jul 30, 5:07 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Grady, Stephens	38 min
Jul 30, 5:28 PM CDT	Severe Thunderstorm Warning	OUN	Coal, Hughes	32 min
Jul 30, 5:29 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Tillman	46 min
Jul 30, 5:35 PM CDT	Severe Thunderstorm Warning	OUN	Garvin, McClain	40 min
Jul 30, 5:40 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Stephens	50 min
Jul 30, 5:43 PM CDT	Special Weather Statement	OUN	McClain	17 min
Jul 30, 6:07 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Garvin, Grady, McClain, Stephens	23 min
Jul 30, 6:14 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Jefferson, Stephens, Tillman	16 min
Jul 30, 6:19 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Pontotoc	26 min
Jul 30, 6:27 PM CDT	Severe Thunderstorm Warning	OUN	Carter, Cotton, Garvin, Jefferson, Johnston, Love and 4 more	48 min
Jul 30, 6:30 PM CDT	Areal Flood Advisory	OUN	Coal, Hughes	3 hr
Jul 30, 6:31 PM CDT	Severe Thunderstorm Warning	OUN	Comanche, Cotton, Tillman	44 min
Jul 30, 6:36 PM CDT	Special Weather Statement	OUN	Pontotoc	24 min
Jul 30, 6:52 PM CDT	Special Weather Statement	OUN	Ellis	23 min
Jul 30, 6:56 PM CDT	Severe Thunderstorm Warning	OUN	Atoka, Coal, Hughes, Johnston, Pontotoc	19 min
Jul 30, 4:06 PM CDT	Special Weather Statement	OUN	Wilbarger	24 min
Jul 30, 4:14 PM CDT	Severe Thunderstorm Warning	OUN	Wilbarger	31 min
Jul 30, 4:25 PM CDT	Severe Thunderstorm Warning	OUN	Foard	20 min
Jul 30, 4:39 PM CDT	Severe Thunderstorm Warning	OUN	Wilbarger	51 min
Jul 30, 4:41 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Knox	49 min
Jul 30, 5:26 PM CDT	Severe Thunderstorm Warning	OUN	Archer, Baylor, Wichita, Wilbarger	49 min
Jul 30, 5:33 PM CDT	Severe Thunderstorm Warning	OUN	Baylor, Foard, Hardeman, Wilbarger	27 min
Jul 30, 5:45 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Wilbarger	30 min
Jul 30, 5:54 PM CDT	Special Weather Statement	OUN	Knox	36 min
Jul 30, 6:10 PM CDT	Severe Thunderstorm Warning	OUN	Foard, Hardeman, Wilbarger	39 min
Jul 30, 6:41 PM CDT	Special Weather Statement	OUN	Wichita	34 min
Jul 30, 6:55 PM CDT	Special Weather Statement	OUN	Baylor	35 min

Nearby

Severe Thunderstorm Warnings in Oklahoma, 2020 Every severe thunderstorm warning in 2020

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.