832
FXUS64 KOUN 071114
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
514 AM CST Thu Nov 7 2024

...New AVIATION...

.KEY MESSAGES...
Updated at 245 AM CST Thu Nov 7 2024

- Heavy rainfall and flooding potential exists on Friday across
  western into northern Oklahoma and western-north Texas.

- A few strong to marginally severe thunderstorms are possible
  from Thursday evening into early Friday morning. Large hail
  would be the main concern with any severe thunderstorm.

- Cooler and dry this weekend before a warm up into early next
  week.

&&

.NEAR TERM...
(Today and tonight)
Issued at 245 AM CST Thu Nov 7 2024

The return of precipitation chances, especially across the western
forecast area, will be the main weather story today. A closed low
across the Desert Southwest is expected to foster the onset of
precipitation across western portions of Oklahoma and north Texas
by this afternoon. While more persistent intervals of rain are
expected to focus across aforementioned areas, pockets of lighter
rainfall may extend as far east as ~Ponca City-Atoka through
sunrise Friday. While a majority of flooding concern is expected
to emerge after 12-3 AM Friday (see short term discussion for
further details), at least localized heavy rainfall is possible by
late Thursday evening. As such, a Flood Watch will begin at 6 PM
this evening for portions of western Oklahoma and western-north
Texas.

Scattered thunderstorms are expected to accompany this activity as
well. While widespread severe weather is not currently expected,
a few strong to marginally severe thunderstorms will be possible,
mainly across western-north Texas. As convection is expected to
remain rooted above the stable boundary layer (north of an
effective warm front in west-central Texas), hail would be the
primary concern with stronger thunderstorms.

Ungar

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 245 AM CST Thu Nov 7 2024

Widespread and locally heavy rainfall is forecast on Friday.
While most areas will see rain during the day, a focused corridor
of heavier rainfall/thunderstorms is expected for areas along and
west of the US-81 corridor. A combination of factors is expected
to yield a pronounced potential for heavy/efficient rainfall and
flooding from western-north Texas into western and northern
Oklahoma.

1. Precipitable Water/Relative Humidity: An unseasonably moist
mid-tropospheric airmass is forecast to advect northward ahead of
the slowly approaching upper system. Even amongst ensemble
systems (HREF), mean precipitable water on the order of ~1.25-1.50
inches is rather anomalous for early November (>95th percentile).
In addition, vertical profiles display highly saturated (>80%)
mid-levels, indicating potential for efficient rainfall
processes.

2. Thunderstorms: At least scattered thunderstorms are expected
amidst the broader precipitation shield across the region on
Friday. Not only will these yield locally heavier rates, potential
exists for repeated rounds of heavier cores/thunderstorms over
similar areas during the day.

3.) Recent Heavy Rainfall: Many locales across western Oklahoma and
western-north Texas, especially along and south of the Interstate 40
corridor, have received rather notable (>3-5 inch) rainfall
totals since last Saturday. In turn, our once receptive soils (to
rainfall) are now much less so heading into this event. Current
Flash Flood Guidance values over 3-6 hours are running <3-inches
for some locations across the aforementioned region. HREF *mean*
values over this time interval near (or exceed) threshold values
in isolated corridors here.

Fusing the above factors together highlights an evident potential
for flooding across western forecast zones through the day on
Friday. A Flood Watch will continue through 9 PM on Friday.

The axis of heavier rain and intermittent thunder will shift
eastward, towards the Interstate 35 corridor/central Oklahoma,
into Friday evening. Residence time of heavier precipitation areas
is expected to remain short enough to avoid widespread concern
for flooding here, though at least localized occurrences in
usual/flood-prone areas will be possible into Friday night. All
precipitation should clear our area by ~daybreak Saturday
morning.

Saturday looks to be a pleasant weather day with nil impact. The dry
slot of the late week system looks to overspread the forecast area
during the day, fostering clearing skies, dry weather and seasonable
temperatures.

Ungar

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 245 AM CST Thu Nov 7 2024

The period looks to feature mostly dry surface conditions and nil
weather impacts. Quasi-zonal flow looks to emerge across the Plains
into the early week, with a slow warming trend expected. Some
locations across western-north Texas have a medium (40-60%) chance
to see 80-degree high temperatures on Tuesday. By the midweek,
attention will turn towards the potential for the passage of another
high-amplitude upper system across the central CONUS. At this
update, some precipitation potential and arrival of a frontal
passage (cooler temperatures) are advertised. Details on this
system will come into better focus into this weekend.

Ungar

&&

.AVIATION...
(12Z TAFS)
Issued at 514 AM CST Thu Nov 7 2024

Mid-level clouds will expand over the area today. Lower clouds
(and associated MVFR and locally IFR ceilings) will move in this
afternoon and become more widespread this evening and overnight.
Showers and thunderstorms will move into western sections late
this afternoon and this evening and spread across the area
through the evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  64  52  61  45 /  10  70  80  80
Hobart OK         63  50  63  41 /  40  90 100  50
Wichita Falls TX  66  59  66  44 /  60  90  90  50
Gage OK           54  42  57  37 /  20  90 100  50
Ponca City OK     62  45  60  47 /   0  50  60  90
Durant OK         74  59  67  53 /  10  30  70  90

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Flood Watch from this evening through Friday evening for
     OKZ009>011-014>017-021>023-033>038.

TX...Flood Watch from this evening through Friday evening for
     TXZ083>085-087-088.

&&

$$

NEAR TERM...09
SHORT TERM...09
LONG TERM....09
AVIATION...26