Special Weather Statement, NWS Norman, OK

Area Forecast Discussion
National Weather Service Norman OK
601 PM CDT Thu Aug 5 2021

...New AVIATION...

.SHORT TERM...
(This evening through Friday)
Issued at 1240 PM CDT Thu Aug 5 2021

CIRA Advected Layer Precipitable Water shows a narrow band of mid-
and high-level moisture, enhancing rainfall efficiency with
ongoing showers. A few mesonet sites are approaching 0.50".
Coverage has increased markedly in central and portions of
southwest Oklahoma necessitating higher precipitation
probabilities, extending downstream into east-central and
southeast Oklahoma through the afternoon. Where surface-based
instability is higher from near Purcell eastward to near Seminole,
convection has been deeper and some lightning has been observed
in the last hour. Although convection will be more robust over
this area due greater surface-based heating/destabilization,
effective shear is marginal for sustained/organized storms, and
thermodynamic environment suggest wind potential from downbursts
should be limited.

We ran a Hysplit backwards trajectory this morning to see the
path of the haze that reduced visibilities slightly. It's been
present in the low-level flow since at least a few days ago over the
Great Lakes region, but has origins in the west due to wildfires
a few days prior to that. Meanwhile HRRR-smoke model shows another
plume of higher level smoke likely impacting sky clarity later
tonight and tomorrow within stronger northwesterly flow on the
downstream side of shortwave trough. Upstream observations suggest
low-level visibilities are unlikely to be significantly reduced
through tomorrow, and thus we did not include haze in the forecast
at this time.

BRB

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 220 PM CDT Thu Aug 5 2021

A mid-level trough will move across the western U.S and into the
Southern Plains this weekend, which will provide the necessary
lift across northern parts of OK for showers and thunderstorms.
There is some model disagreement on how far south the trough will
move, so keeping PoPs confined to the northern parts of the state
for now. Additional precipitation chances are possible in the
middle of next week, as another round of mid-level perturbations
move in through the area. Models this far out suggest that
precipitation will be confined to northwestern and northern OK,
but areal coverage could increase/change in subsequent forecasts.

With the aforementioned rain chances being isolated in nature,
temperatures in the long term do not change much. Expect high
temperatures slightly above average and ranging from the mid to
upper 90s across most of the state. Early part of next week could
see a Heat Advisory for parts of the area, as heat indices will at
or near 105. WBGT seems to be in agreement with heat-related
stress in south central and southeastern OK early next week.
Persistent southerly flow, at times strong southerly flow, will
keep dewpoints in the upper 60s to lower 70s throughout the long
term.

Bunker

&&

.AVIATION...
(00Z TAFS)
Issued at 557 PM CDT Thu Aug 5 2021

Scattered showers continue to develop to the west of an advancing
line of showers/storms that will continue to move through
southeast Oklahoma early this evening. Do not expect to have any
mention of these at any TAF site as this lingering activity is
expected to diminish quickly this evening. Othewise, some mid
clouds linger overnight into the day tomorrow with a light
southeast wind becoming more southerly late tonight into the day
tomorrow. Across west could see some speeds above 12kts.

&&

.UPPER AIR...
Issued at 221 PM CDT Tue Aug 3 2021

No Upper Air flights are planned.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  69  93  74  95 /  20   0   0   0
Hobart OK         69  97  73  98 /  10   0   0   0
Wichita Falls TX  71  96  75  99 /  20   0   0   0
Gage OK           66  97  72  97 /  10   0   0  20
Ponca City OK     66  94  73  97 /  20   0   0  10
Durant OK         69  94  72  97 /  60   0   0   0

&&

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

SHORT TERM...12
LONG TERM....13
AVIATION...30

Hazardous Weather Outlook
National Weather Service Norman OK
1128 AM CDT Thu Aug 5 2021

OKZ004>048-050>052-TXZ083>090-061630-
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-
1128 AM CDT Thu Aug 5 2021

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

.DAY ONE...This Afternoon and Tonight...

.Thunderstorms...
Scattered thunderstorms are possible into this evening over
portions of Oklahoma and northern Texas. Cloud to ground lightning
and gusty winds are the main concerns.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday...

.Heat and Humidity...
Increasing humidity and temperatures will result in increased
risk for heat stress starting this weekend and continuing into
the following week.

.Thunderstorms...
Scattered thunderstorms are expected late Saturday into early
Sunday over northern Oklahoma. Some storms may become strong to
marginally severe.

Thunderstorm chances will return to portions of the area towards
the middle of next week.

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
356 PM CDT Thu Aug 5 2021

OKZ007-008-052130-
Kay OK-Grant OK-
356 PM CDT Thu Aug 5 2021

...SIGNIFICANT WEATHER ADVISORY FOR southwestern Kay and southeastern
Grant Counties Until 430 PM CDT...

AT 354 PM CDT, a strong thunderstorm was located 6 miles southeast of
Lamont, moving northeast at 10 MPH.

HAZARDS INCLUDE...
Hail up to one-half inch diameter...
Wind gusts to 40 MPH...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe weather is not expected and no warnings are anticipated at
this time.

&&

LAT...LON 3661 9723 3659 9741 3659 9753 3669 9759
      3682 9737
TIME...MOT...LOC 2054Z 240DEG 10KT 3665 9746

30

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
357 PM CDT Thu Aug 5 2021

OKZ011-017-018-052130-
Major OK-Kingfisher OK-Blaine OK-
357 PM CDT Thu Aug 5 2021

...SIGNIFICANT WEATHER ADVISORY FOR southeastern Major...northwestern
Kingfisher and northeastern Blaine Counties Until 430 PM CDT...

AT 354 PM CDT, a strong thunderstorm was located 4 miles northwest of
Okeene, moving east at 20 MPH.

HAZARDS INCLUDE...
Hail up to one-half inch diameter...
Wind gusts to 40 MPH...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe weather is not expected and no warnings are anticipated at
this time.

&&

LAT...LON 3617 9811 3616 9809 3605 9809 3606 9842
      3626 9848 3634 9811
TIME...MOT...LOC 2054Z 258DEG 17KT 3617 9836

30

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
655 PM CDT Thu Aug 5 2021

OKZ015-016-060030-
Dewey OK-Custer OK-
655 PM CDT Thu Aug 5 2021

...SIGNIFICANT WEATHER ADVISORY FOR central Dewey and central Custer
Counties Until 730 PM CDT...

AT 652 PM CDT, strong thunderstorms were along a line extending from
6 miles north of Putnam to 7 miles east of Butler, moving south at 20
MPH.

HAZARDS INCLUDE...
Hail up to one-half inch diameter...
Wind gusts to 40 MPH...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe weather is not expected and no warnings are anticipated at
this time.

&&

LAT...LON 3565 9888 3549 9908 3590 9918 3611 9894
TIME...MOT...LOC 2352Z 359DEG 17KT 3594 9900 3568 9906

30

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE Norman OK
911 PM CDT Thu Aug 5 2021

OKZ022-060245-
Washita OK-
911 PM CDT Thu Aug 5 2021

...SIGNIFICANT WEATHER ADVISORY FOR southwestern Washita County Until
945 PM CDT...

AT 908 PM CDT, a strong thunderstorm was located near Dill City,
moving south at 15 MPH.

HAZARDS INCLUDE...
Hail up to one-half inch diameter...
Wind gusts to 40 MPH...
Minor flooding in areas of poor drainage...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Monitor the weather situation closely and be alert for threatening
weather conditions.

&&

LAT...LON 3538 9922 3537 9901 3512 9899 3513 9931
TIME...MOT...LOC 0208Z 12DEG 12KT 3532 9914

30