934
FXUS64 KOUN 200423
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1123 PM CDT Fri Jul 19 2024

...New AVIATION...

.SHORT TERM...
(This evening through Saturday)
Issued at 313 PM CDT Fri Jul 19 2024

Our upcoming "wetter" weekend now in the short term and forecast is
still on track although has slightly changed with the convection
strength when it initially starts, surface boundaries and rainfall
amounts.  Still seeing a weak trough digging through the U.S. Great
Plains & Upper Midwest Regions from the main upper jet stream flow
over Canada, and this trough will still provide the upper support
for rain/storms this weekend.

Tonight will see another MCS over the Central through Southern
High Plains as this disturbance rotates through the upper ridge
persisting over the U.S. Southwest. Tonight`s MCS on the higher
plains may also be enhanced by a surface trough stretched across
western Kansas through the Oklahoma/Texas Panhandles and this
surface boundary may move into our area late Saturday. This MCS is
expected to develop in a high CAPE/strong sheared environment
with upper moderate to low end instability and up to 40 kts
effective shear. Models runs have also been consistent with a
southerly low- level jet developing tonight, strongest at 850 mb
with the eastern extent of the jet maxima over our western CWA.
Conditions will be favorable for organized severe storms with this
MCS as well as a potential for supercells early in the event.
Right now expecting the highest severe risk tonight over western
Kansas to the Oklahoma Panhandle but some of these organized
severe storms in the northwest flow aloft could be steered into
northwest Oklahoma before weakening into a less unstable and
weaker sheared environment. As a result, northwest Oklahoma will
be in a Marginal severe risk area with damaging wind gusts as the
main severe risk. D-CAPE values expected will be sufficient for
severe winds producing damaging downdrafts. As far as timing, most
CAMs are projecting around midnight although one of the solutions
HRW NSSL is an hour earlier. Confidence is high we shouldn`t see
any late afternoon convection out west due to a strong cap, and
confidence increases for the timing of this MCS in our area later
in the evening toward midnight. The MCS will have weakened to
below severe across the remainder of western Oklahoma and adjacent
western north Texas through the remaining morning hours.

After the MCS activity on Saturday morning, expecting a series of
shortwaves coming through the aforementioned trough to initiate rain
with more elevated convection during the afternoon extending into
central Oklahoma. Overall not expecting any severe weather with
these higher-based storms.  However this would be conditional should
any outflow boundaries from earlier storms linger resulting in more
unstable surface-based storms to reinitiate.

&&

.LONG TERM...
(Saturday night through next Thursday)
Issued at 313 PM CDT Fri Jul 19 2024

Storm POPs will increase into southeast Oklahoma by Saturday evening
and remain widespread Saturday night and Sunday across our area
possibly becoming more surface-based with the aforementioned surface
boundary pushing through and stalling across northern Texas on
Monday. Overall our CWA will be getting some accumulating but not
heavy rain amounts with total accumulations from Saturday through
Monday between 0.25 to 0.50. Grand Ensemble probabilities are only
10-30% of receiving greater than a half inch of total rainfall
during that 3-day time period. The main upper jet still expected to
remain in an Omega blocking pattern through mid-week keeping the
weak trough over the Southern Plains. This will keep us in a wetter
pattern for Monday with the higher probabilities across our southern
CWA near the surface front into Tuesday.  The troughing will also
keep our temperatures not as hot yet cooler than seasonably normal
as well as keeping those heat indices down.  By Wednesday on, the
upper trough will have moved out and replaced by the persisting
ridge over the U.S. Southwest. Along with a return of south winds,
will start to see a warming trend with temperatures gradually
returning to normal for the latter half of next week. Looking beyond
at the Climate Prediction Centers 8-14 day outlook, much of our area
is outlooked for "Near Normal" temperatures with northwest Oklahoma
leaning 30-40% leaning "Above Normal." Guidance suggests a gradual
warming trend going into August.

&&

.AVIATION...
(06Z TAFS)
Issued at 1122 PM CDT Fri Jul 19 2024

The initial storms in Kansas dissipated while moving toward
the forecast area or have remained farther west. But another round
of storms have formed in northwest Kansas and we may see
additional development that will move toward the area Saturday
morning, and storm chances will be increasing.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  68  89  68  85 /  10  30  60  30
Hobart OK         70  95  67  89 /  20  30  50  20
Wichita Falls TX  71  95  70  91 /  10  30  40  40
Gage OK           67  92  65  86 /  30  30  30  20
Ponca City OK     66  84  67  85 /  10  30  60  30
Durant OK         67  93  70  89 /   0   0  30  40

&&

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

$$

SHORT TERM...68
LONG TERM....68
AVIATION...26