Alert archive / Oklahoma / Special Weather Statements in 2021

Special Weather Statement, NWS Norman, OK

September 3, 2021Alfalfa County, Oklahoma

NWS Norman, OK issued this special weather statement at Sep 3, 2021, 3:49 PM CDT for Alfalfa County, Oklahoma. It was in force for 26 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
Sep 3, 2021, 3:49 PM CDT (20:49 UTC)
Expired
Sep 3, 2021, 4:15 PM CDT
In force
26 min
Issued by
NWS Norman, OK
Hail
0.00 in
Wind
50

County Alfalfa County, OK

The radar

The Vance AFB radar (KVNX), 37 km from the middle of the area, began a volume at 20:52 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 12:00Z, 8.8 hours before the alert went out and 176 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-pSkew-T log-p diagram, Dodge City, at 12:00Z on 2021-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 885 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Dodge City, at 12:00Z on 2021-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 117 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
885 J/kg
Mixed-layer CIN
-100 J/kg
Mixed-layer LCL
1122 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
117 m²/s²
0-3 km storm-relative helicity
86 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.1

Open this sounding in Storm Lab

The text

As transmitted.

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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 Sep 3, 2:38 PM CDT, 1 hour 11 minutes earlier.

Area forecast discussion, Sep 3, 2:38 PM CDT, 1 hour 11 minutes before
Area Forecast Discussion
National Weather Service Norman OK
238 PM CDT Fri Sep 3 2021

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Saturday)
Issued at 235 PM CDT Fri Sep 3 2021

Heat and humidity will continue to be a concern for at least the
remainder of Friday and into Saturday for portions of Oklahoma and
western north Texas. Triple digit heat index values will continue
through eastern and southern Oklahoma as well as western north Texas
ahead of the advancing cloud cover and precipitation. Temperatures
will slightly decrease for Saturday along with continued mixing of
lower dewpoints in southern Oklahoma. While the 100+ heat index
values will continue, a heat advisory will likely not be needed.

Showers continue in northern Oklahoma, with storms now beginning to
develop along a surface boundary in the Oklahoma/Texas panhandle,
and will begin moving and developing in western Oklahoma in the next
hour. Surface/mixed layer CAPE (>2000 J/kg) as well as lower level
lapse rates (widespread >8C) are definitely plentiful enough to
support storms developing, however the mid-level lapse rates ( < 6C)
as well as the wind shear (marginal in all layers) are weak and do
not support any organized storms. The general ongoing trend are
quick up/down storms: the storm rapidly develops, becomes a prolific
lightning producer, then weakens rapidly. The high amount of
precipitable water in the area (widespread >1.5", areas >2") will
fuel the continued development of shower/storms, and storms are
expected become more widespread throughout the evening and overnight
along and ahead of the surface boundary. With the high amount of
moisture available, heavy rainfall and flooding conditions will be
the main concern, with severe winds also possible with strong
downdraft generation within these storms.

Zwink

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 235 PM CDT Fri Sep 3 2021

No major changes with the evolution of the precipitation event as it
moves through Oklahoma and western north Texas. The weakening upper
level ridge eventually gives way to an upper level trough that is
moving through the Great Lakes region, continuing the gradual shift
southward of precipitation chances Saturday night until the eventual
arrival of a surface boundary. This trough has trended stronger,
with more upper-level support available for widespread showers and
storms to develop. This east-west surface boundary will enter from
Kansas late Saturday night and move south through Oklahoma and
western north Texas Sunday afternoon. Precipitation will mostly be
focused around this boundary, with a primary concern of heavy
rainfall, possible flooding, and strong winds.

Precipitation chances in southern Oklahoma/western north Texas will
linger into Monday as the upper level trough exits to the east.
Surface temperatures will be seasonably cooler, with highs behind
the front in the 80s Sunday with the precipitation and cloud cover.
An upper level ridge that was building along the west coast will
begin to shift eastward as the upper level trough exits eastward,
which will result in dry conditions Monday afternoon throughout the
remainder of the week. Temperatures will quickly return to at or
above seasonably average amounts by Monday.

Zwink

&&

.AVIATION...
(18Z TAFS)
Issued at 106 PM CDT Fri Sep 3 2021

VFR conditions are expected to continue Friday afternoon through
Saturday at most terminals. Showers and thunderstorms are ongoing
along the Kansas/Oklahoma border, and will continue through the
evening and overnight. These storms will gradually southward over
the next day, and may begin to impact the northern terminals
overnight.

&&

.UPPER AIR...
Issued at 630 PM CDT Thu Sep 2 2021

No upper air flights are planned at this time.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  76  95  70  83 /  10  30  70  30
Hobart OK         75  97  69  85 /   0  30  60  40
Wichita Falls TX  76  98  73  88 /   0  10  30  40
Gage OK           71  86  64  84 /  40  70  50  20
Ponca City OK     74  90  65  85 /  50  70  60  10
Durant OK         74  97  74  89 /   0   0  20  40

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory until 7 PM CDT this evening for OKZ019-020-026-
     030>032.

TX...None.
&&

SHORT TERM...50
LONG TERM....50
AVIATION...50
Hazardous weather outlook, Sep 3, 11:32 AM CDT, 4 hours 17 minutes before
Hazardous Weather Outlook
National Weather Service Norman OK
1132 AM CDT Fri Sep 3 2021

OKZ004>048-050>052-TXZ083>090-041645-
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-
1132 AM CDT Fri Sep 3 2021

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

.DAY ONE...Today and Tonight...

.Heat...
Portions of central and eastern Oklahoma will again experience
heat indices as high as 105 degrees this afternoon.

.Thunderstorms...
Thunderstorm chances will increase this afternoon and continue
into the night. A few storms could become severe this evening with
damaging winds being the primary threat. Heavy rainfall with
thunderstorms may cause localized flooding.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday...

.Heat...
Portions of eastern Oklahoma could once again experience heat
indices up to 105 degrees Saturday afternoon.

.Thunderstorms...
Thunderstorms are possible Saturday and Saturday night across the
area. A few severe storms with damaging winds are possible. Heavy
rainfall with thunderstorms may cause localized flooding.
Thunderstorm chances will linger into Sunday, mainly across
southern Oklahoma and north Texas.

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, Sep 3, 2:45 PM CDT, 1 hour 4 minutes before
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Special weather statement, Sep 3, 3:00 PM CDT, 49 minutes before
Special Weather Statement
National Weather Service Norman OK
300 PM CDT Fri Sep 3 2021

OKZ004-009-032030-
Harper OK-Ellis OK-
300 PM CDT Fri Sep 3 2021

...A strong thunderstorm will impact portions of northwestern Ellis
and southwestern Harper Counties through 330 PM CDT...

At 300 PM CDT, Doppler radar was tracking a strong thunderstorm 5
miles southwest of Laverne, moving east at 15 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Laverne and May.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3675 10000 3686 9975 3657 9969 3655 10001
TIME...MOT...LOC 2000Z 249DEG 13KT 3664 9997

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Ware
Special weather statement, Sep 3, 3:14 PM CDT, 35 minutes before
Special Weather Statement
National Weather Service Norman OK
314 PM CDT Fri Sep 3 2021

OKZ005-006-032045-
Alfalfa OK-Woods OK-
314 PM CDT Fri Sep 3 2021

...A strong thunderstorm will impact portions of east central Woods
and west central Alfalfa Counties through 345 PM CDT...

At 313 PM CDT, Doppler radar was tracking a strong thunderstorm near
Avard, moving northeast at 10 mph.

HAZARD...Wind gusts up to 50 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Alva, Dacoma, Avard and Hopeton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3658 9881 3673 9888 3686 9860 3664 9847
TIME...MOT...LOC 2013Z 236DEG 10KT 3667 9876

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH

Ware
Special weather statement, Sep 3, 3:45 PM CDT, 4 minutes before
Special Weather Statement
National Weather Service Norman OK
345 PM CDT Fri Sep 3 2021

OKZ004-009-010-014-032115-
Woodward OK-Roger Mills OK-Harper OK-Ellis OK-
345 PM CDT Fri Sep 3 2021

...Strong thunderstorms will impact portions of Ellis, northwestern
Roger Mills, southeastern Harper and southwestern Woodward Counties
through 415 PM CDT...

At 345 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Laverne to 6 miles south of Arnett.
Movement was northeast at 30 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Woodward, Shattuck, Laverne, Buffalo, Arnett, Gage, Fargo, Fort
Supply, May, Selman, Harmon and Tangier.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3616 9938 3604 9938 3594 9984 3674 9995
      3698 9948
TIME...MOT...LOC 2045Z 246DEG 26KT 3670 9988 3604 9979

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Ware
Special weather statement, Sep 3, 3:49 PM CDT, 0 minutes before
Special Weather Statement
National Weather Service Norman OK
349 PM CDT Fri Sep 3 2021

OKZ005-006-032115-
Alfalfa OK-Woods OK-
349 PM CDT Fri Sep 3 2021

...A strong thunderstorm will impact portions of east central Woods
and southwestern Alfalfa Counties through 415 PM CDT...

At 349 PM CDT, Doppler radar was tracking a strong thunderstorm near
Dacoma, moving east at 20 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Cherokee, Helena, Carmen, Dacoma, Lambert and Hopeton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3654 9867 3673 9868 3681 9831 3652 9826
TIME...MOT...LOC 2049Z 263DEG 16KT 3665 9858

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

Ware

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 3:02 AM CDTHeat AdvisoryOUNHughes, Lincoln, Logan, Payne, Pottawatomie, Seminole16 hr
Sep 3, 2:45 PM CDTSpecial Weather StatementOUNWoods30 min
Sep 3, 3:00 PM CDTSpecial Weather StatementOUNHarper30 min
Sep 3, 3:07 PM CDTSevere Thunderstorm WarningOUNEllis, Harper38 min
Sep 3, 3:14 PM CDTSpecial Weather StatementOUNWoods31 min
Sep 3, 3:45 PM CDTSpecial Weather StatementOUNEllis, Harper30 min
Sep 3, 4:14 PM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods46 min
Sep 3, 4:17 PM CDTSpecial Weather StatementOUNEllis, Woodward28 min
Sep 3, 4:48 PM CDTSpecial Weather StatementOUNWoodward42 min
Sep 3, 5:30 PM CDTSpecial Weather StatementOUNWoods30 min
Sep 3, 6:04 PM CDTSpecial Weather StatementOUNGarfield26 min

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.