Flood Watch 10, NWS Norman, OK

967 
WGUS64 KOUN 110350
FFAOUN

Flood Watch
National Weather Service Norman OK
1050 PM CDT Sun Oct 10 2021

OKZ013-019-020-025-026-029-030-110500-
/O.CAN.KOUN.FA.A.0010.000000T0000Z-211011T0900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Noble-Logan-Payne-Oklahoma-Lincoln-Cleveland-Pottawatomie-
Including the cities of Perry, Shawnee, Norman, Prague, Guthrie, 
Stroud, Chandler, Meeker, Wellston, Oklahoma City, Davenport, 
Stillwater, and Moore
1050 PM CDT Sun Oct 10 2021

...FLOOD WATCH IS CANCELLED...

The Flood Watch for portions of central Oklahoma and northern 
Oklahoma, including the following areas, in central Oklahoma, 
Cleveland, Lincoln, Logan, Oklahoma, Payne and Pottawatomie. In 
northern Oklahoma, Noble has been cancelled.

The potential for heavy rain has ended. However, flooding of 
low-lying and flood prone areas may persist into early Monday 
morning from heavy rainfall that occurred Sunday evening. Please 
continue to heed remaining road closures.

$$

.speg.

Area Forecast Discussion
National Weather Service Norman OK
553 AM CDT Sun Oct 10 2021

...New AVIATION...

.SHORT TERM...
(Today and tonight)
Issued at 228 AM CDT Sun Oct 10 2021

Strong to severe storms are likely to impact much of the area
later this afternoon and into the evening. Primary threat is
damaging winds, and large hail with the strongest storms.
Tornadoes are also possible. Locally heavy rainfall is possible
Sunday evening, especially across central and eastern Oklahoma.

An intense, mid-level shortwave trough is expected to lift across
the Southern Plains this afternoon, becoming more negatively
tilted as it moves into Oklahoma. An attendant surface cyclone is
expected to form late this morning/early afternoon, with a cold
front in its wake. Ahead of the approaching cyclone, southerly
surface flow will aid in moisture advection through the day. The
magnitude of moisture advection (and depth), however, is still in
question. The NAM is forecasting upper 60s to low 70s dewpoints as
far north as northern Oklahoma. The GFS and ECMWF both have low
to mid 60s dewpoints across the area. Looking at current
observations, mid 60s dewpoints are already present across central
Texas; so very well could have low to mid 60s dewpoints as far
north as the OK/KS border by tomorrow afternoon.

Convective initiation and evolution:

Convection could initiate as early as 4pm near the dryline and
along the cold front that will be draped across southwest Oklahoma
and will extent northeastward into north central Oklahoma. At
this time, there is a brief window of discrete supercells owing to
favorable shear profiles (effective shear > 45 kts) and steep
mid-level lapse rates. The primary threat in this window will be
very large hail, damaging winds and a few tornadoes. As the
evening progresses, the cold front will advance
south/southeastward and the dryline will shift eastward.
Convection is expected along these boundaries as they move through
the area and the convection should quickly evolve into a line of
storms. A 50-60 kt low-level jet should increase shortly after
sunset, which will help bolster the low-level shear profile and
present the threat for overnight QLCS tornadoes and damaging wind
gusts. Locally heavy rainfall could accompany these storms through
the afternoon and evening, especially across central and eastern
Oklahoma. Here, multiple rounds of storms are possible, which
could present the risk for flooding and flash flooding.

It is important to remember that any storms this
afternoon/evening present the threat for all hazards. It is never
too early to make sure you have a plan in place, should a warning
be issued. Make sure you have multiple ways of receiving weather
information, and check back for additional updates.

Bunker

&&

.LONG TERM...
(Monday through Saturday)
Issued at 153 AM CDT Sun Oct 10 2021

The upcoming week will have a couple of significant short-wave
troughs with periods of humid and dry airmasses and and enhanced
chances for rain and thunderstorms. However, no cool air mass is set
to enter the southern plains next week with lower temperatures
coming from rain. In contrast Monday will begin with weak short-wave
ridging passing over the southern plains with warm and dry
conditions. A more active pattern starts Tuesday with the approach
of a strong upper-level trough from the west. Boundary layer
moisture will rapidly move northward into Oklahoma Tuesday with
showers and thunderstorms. Severe weather is possible later Tuesday
with increased shear and moisture advection as the upper low moves
from southern Colorado into western Nebraska with the trough passing
through northwestern Oklahoma. The southwesterly flow in the wake of
this feature will allow the surface front to weaken/stall over
southeastern Oklahoma on Wednesday. By Thursday a pattern change is
expected to result in another short-wave trough approaching the
southern plains, but this time from the northwest. A surface front
is expected to arrive from the northwest and with deeper moisture
still resident in the southeast part of Oklahoma, showers and
thunderstorms are again expected later Thursday into Friday. Severe
weather chances appear lower with this feature than with the one on
Tuesday. This front on Friday is expected to finally bring cooler
and considerably drier air from the northwest.

&&

.AVIATION...
(12Z TAFS)
Issued at 548 AM CDT Sun Oct 10 2021

A cold front is currently moving into parts of northwest OK this
morning. This cold front will continue to push south/southeastward
through the day and into the evening. A period of gusty winds
behind this front are expected. Later this afternoon, storms are
expected to develop along the cold and well behind the front this
afternoon and into the evening. This will result in MVFR
conditions developing at most sites through the middle to end of
the period. Some of the storms that develop this afternoon and
evening could be strong to severe, where all hazards are possible.

&&

.UPPER AIR...
Issued at 228 AM CDT Sun Oct 10 2021

An Upper Air flight is planned for 12Z, and 20Z Sunday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  85  55  76  56 /  60  90   0   0
Hobart OK         87  53  80  57 /  70  60   0   0
Wichita Falls TX  91  55  82  58 /  30  40   0   0
Gage OK           71  47  78  55 /  70  70   0   0
Ponca City OK     85  55  76  53 /  60 100   0   0
Durant OK         89  60  81  57 /  10  90   0  10

&&

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

SHORT TERM...13
LONG TERM....09
AVIATION...13

Hazardous Weather Outlook
National Weather Service Norman OK
400 AM CDT Sun Oct 10 2021

OKZ004>048-050>052-TXZ083>090-111000-
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-
400 AM CDT Sun Oct 10 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...
There is a risk for severe thunderstorms late this afternoon and
evening across all but northwestern Oklahoma. Isolated storms are
expected to form from southwestern and central Oklahoma into western
north Texas. Subsequently, these storms and others are expected to
form a squall line across south central and southeast Oklahoma.
Damaging wind and large hail are the primary hazards. However,
tornadoes are also possible, especially with the early storms and
during the formation of the squall line.

.Flooding...
There is a risk for flooding or flash flooding with thunderstorms
this afternoon and evening over much of the eastern three-quarters
of Oklahoma. The relatively greater risk for flooding is northeast
of Oklahoma City this evening.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

.Thunderstorms...
Severe storms will be possible across much of Oklahoma and western
north Texas Tuesday into early Wednesday. All modes of severe
weather are possible, particularly in northwestern Oklahoma.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will be needed late Sunday and again Tuesday.