Special Weather Statement, NWS Norman, OK

Area Forecast Discussion
National Weather Service Norman OK
640 AM CDT Mon Aug 16 2021

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 348 AM CDT Mon Aug 16 2021

Scattered showers and thunderstorms are developing and moving into
northwest Oklahoma this morning as a relatively subtle shortwave
moves south over the central Plains and towards Oklahoma. This
feature will aid in thunderstorm development through the day. CIN
values decrease through the day for some potential of surface-
based convection, especially in areas where lift is enhanced by
the shortwave... but there still seems to be enough inhibition
that storm coverage may not be too large. Precipitable water
values this afternoon and evening will be above 90th percentile
and storms will be slow moving, so heavy rainfall will be possible
in localized areas where thunderstorms persist, but again the
flooding potential may not be too widespread because storms are
not expected to be very widespread. And again there is some
potential for strong to marginally severe storms given the
moderate instability that develops today, but weak shear will
prevent significant storm organization.

As has been the case recently, we will likely see some widely
scattered diurnal convection in the southeast as well today.

&&

.LONG TERM...
(Tuesday through Sunday)
Issued at 304 AM CDT Mon Aug 16 2021

An upper-level circulation will have reached Oklahoma by Tuesday
morning, and will provide a small amount of support for convection
during the day Tuesday. The disturbance will weaken slowly over
the region, but daily outbursts of convection will likely flare up
for the remainder of the week. With a lightly-capped, very moist
atmosphere, it won't require much forcing to generate generally
unfocused areas of convection (likely forming mainly on outflow
boundaries left over from earlier convection).

There may be enough instability and shear to support the
occasional strong storm, maybe even a few isolated severe storms,
but organized severe weather is not likely.

Minimal changes in day-to-day temperatures are expected, as no
significant changes are expected in the airmass.

&&

.AVIATION...
(12Z TAFS)
Issued at 639 AM CDT Mon Aug 16 2021

Scattered thunderstorms are expected today, mainly across
northwestern Oklahoma including areas near KWWR. These storms will
be slow moving. Elsewhere, there may be localized areas of ground
fog. The fog would typically be rather shallow, but may affect
some airports as may be occurring near KOUN. This fog will burn
off quickly this morning.

&&

.UPPER AIR...
Issued at 315 AM CDT Sat Aug 14 2021

No upper air flights are currently scheduled.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  88  70  88  71 /  10  10  20  20
Hobart OK         91  69  91  69 /  20  20  30  20
Wichita Falls TX  91  71  91  71 /  10  10  40  30
Gage OK           89  67  89  67 /  30  30  30  10
Ponca City OK     88  67  89  68 /  20  20  20  10
Durant OK         90  71  91  71 /  20  10  30  20

&&

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

SHORT TERM...26
LONG TERM....23
AVIATION...26

Hazardous Weather Outlook
National Weather Service Norman OK
435 AM CDT Mon Aug 16 2021

OKZ004>048-050>052-TXZ083>090-170945-
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-
435 AM CDT Mon Aug 16 2021

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

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

.Thunderstorms...
Scattered thunderstorms are expected today with the highest
chances across northwest Oklahoma, and isolated strong to
marginally severe storms will be possible, mainly from mid-
afternoon through mid-evening. There is a marginal risk of severe
thunderstorms across northwestern Oklahoma, generally near and
west of a line from Wakita to Canton to Clinton to Mangum where
hail of around the size of quarters and wind gusts of 60 mph will
be possible with the strongest storms. Slow moving thunderstorms
will produce heavy rainfall and local flooding will be possible in
areas where storms persist.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday...

.Thunderstorms...
A daily chance for thunderstorms will continue through Sunday.
Heavy rain may accompany the storms, and some may produce gusty
winds and hail. However, organized severe weather is not
expected.

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
622 AM CDT Mon Aug 16 2021

OKZ004-009-161145-
Harper OK-Ellis OK-
622 AM CDT Mon Aug 16 2021

...A strong thunderstorm will impact portions of northwestern Ellis
and southwestern Harper Counties through 645 AM CDT...

At 622 AM CDT, Doppler radar was tracking a strong thunderstorm 11
miles southwest of May. This storm drifting slowly southeast.

HAZARD...Winds in excess of 40 mph and penny 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...
May and Catesby.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3645 10000 3664 9999 3664 9973 3637 9980
TIME...MOT...LOC 1122Z 282DEG 4KT 3654 9993

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

..speg.

Special Weather Statement
National Weather Service Norman OK
649 AM CDT Mon Aug 16 2021

OKZ009-161215-
Ellis OK-
649 AM CDT Mon Aug 16 2021

...A strong thunderstorm will impact portions of northwestern Ellis
County through 715 AM CDT...

At 648 AM CDT, Doppler radar was tracking a strong thunderstorm 10
miles southwest of May, moving east at 5 mph.

HAZARD...Winds in excess of 40 mph, penny size hail and very heavy
         rainfall.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible. Heavy rainfall will create reduced visibility
         and may flood poorly drained areas.

Locations impacted include...
Catesby.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 3642 10000 3659 9999 3659 9964 3633 9973
TIME...MOT...LOC 1148Z 284DEG 6KT 3650 9987

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

..speg.