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000
FXUS63 KEAX 110755
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
255 AM CDT Thu Apr 11 2024

.KEY MESSAGES...

- Light Showers Central Missouri, Windy Today

- Very Warm This Weekend

- Active Weather Possible Start of Next Week

&&

.DISCUSSION...
Issued at 255 AM CDT Thu Apr 11 2024

Mid to upper-level trough axis is moving across the region early
this morning with associated surface cyclone starting to exit the
eastern portions of our forecast area. Cold front as of 07z this
morning is roughly along a line from the KC Metro to Trenton, MO.
Our forecast will remain on the backside of cyclonic flow through at
least the rest of the morning, which will keep skies overcast during
that time. Clearing is noted on satellite imagery over most of
central Kansas and central Nebraska and that clearing will slowly
work its way across our area by the afternoon. Strong gradient at
925mb with modest CAA will result in gusty winds on the backside of
the front through portions of this morning and afternoon. Wind gusts
around 40 MPH may be possible at times. Ensemble probabilities for
exceeding 45 MPH though are less than 30 percent across most of the
area, thus have not issued any wind related headlines. Dry air and
windy conditions will lead to elevated fire weather concerns this
afternoon, especially for northwest Missouri and northeast Kansas.
However, with recent moisture added to fuels across the area, does
not appear to be an overly potent setup for fire weather issues like
the area had back in March. Will continue to monitor wind and
humidity trends through the afternoon and will update the forecast
as needed for this. With strong convergence along the cold front and
stratiform cloud cover, light showers are still possible for eastern
and southeastern counties in our area through early this morning,
and a another weak shot of vorticity this afternoon may be able to
force a few showers along the Hwy. 63 corridor. However, low-level
moisture content remains very low. A lot of the radar reflectivity
returns during the overnight hours have not been tied to any reports
at the surface of precipitation. Further, CAM trends for this
morning and afternoon have backed off quite bit, with simulated
reflectivity fields in the CAMs be associated with less than 0.01
inch of QPF. Better mid-level support for rain activity appears to
be in far eastern Missouri. Have placed slight chance POPs in our
far east for this afternoon but overall is not expected to amount to
much. Temperatures today will generally be in the mid 60s. Spread
between the inner-quartile values of the NBM members is narrow,
appears most guidance has a good handle on how the cold front will
move through the area today. The main trough axis will be east of
the area by Friday morning and will start to give way to an
amplified H5 ridge but we may see another vort max on the backside
of the system delay mid-level height rises by a few hours. However,
drier air continues to filter in with surface anticyclone dropping
southward into the Central Plains. This will begin to erode
lingering stratiform clouds across central and eastern Missouri by
Friday morning (western portions of our forecast may already be
clear by then). With approaching ridge axis, AVA regime sets up by
Friday afternoon and strong subsidence should work to clear clouds
out. Low-level flow slowly shifts more southwesterly through Friday
transitioning the area to a WAA regime. This may allow temperatures
Friday to reach the lower 70s in our western counties, while eastern
counties hold onto mid and upper 60s.

Mid-level ridge axis continues to move eastward across the Central
Plains Saturday morning, with strong southwesterly flow between
925mb and 850mb rapidly increasing the strength of WAA across the
area. With a lack of return moisture flow, not expecting clouds to
be overly dense which should allow for insolation during peak
heating. The signal for temperatures in the lower 80s Saturday
afternoon is still there, as has been the case with most ensemble
suites for nearly the past week. Inner-quartile spread amongst NBM
members has increased slightly, but still favors temperatures in the
lower 80s, with the 75th percentile values in the mid 80s. During
Saturday, deterministic GFS/NAM/ECMWF depict an omega-block pattern
at H5 with ridging over the central CONUS, a closed-low over the
eastern Great Lakes Region and another closed-low off the west
coast. However, deterministic solutions are showing a decent signal
for a few vort maxes to eject ahead of the system across the
Intermountain West and into the Central Plains, that by Sunday will
de-amplify the ridge pattern across the region and lead to brisk
zonal mid-level flow. But this does not happen until after the
thermal ridge axis passes through the area, which on Sunday supports
temperatures in the the mid to upper 80s across most of the area. A
few locations have 75th and 90th percentile values that push the
lower 90s. It may be difficult to reach that if the closed-low
system west of the area does not progress far enough east to help
push the thermal ridge axis across the area. Therefore, will keep
Sunday`s highs in the official forecast the mid to upper 80s. A few
passing clouds may occur with this if any Pacific Moisture gets
picked up and ejects ahead with any vort maxes. But closer to the
surface and within the boundary layer moisture will be lacking.
Therefore, maintaining a dry forecast through the weekend. Ensemble
probabilities for any measurable precipitation through the weekend
are generally less than 20 percent across our forecast area.

For the start of next week, deterministic solutions are still
struggling to come to consensus on how the closed-low system and
stronger PV anomaly over the Pacific Evolves and breaks down the
ridging from the weekend. Deterministic GFS places the track of
better mid-level CVA from the Colorado Front Range through Central
Nebraska Monday afternoon into Tuesday. Meanwhile, deterministic
ECMWF tracks this a bit further east and provides better kinematic
forcing to our area, which on Monday would bring active
thunderstorms to about the Interstate 35 corridor. The WPC Cluster
Analysis also indicates this uncertainty, as two of the clusters
lift the closed-low/trough earlier, while the other two let is
travel further east before the stronger CVA gets ahead of the trough
axis and lifts it northward. With that being said, probabilities for
CAPE of at least 1000 J/kg are around 60 percent for Monday
afternoon and eveing. Overall probabilities for measurable
precipitation are generally above 70 percent across most of our
forecast area. With that, increasing confidence in precipitation for
our area starting Monday and continuing into Tuesday. The main
question will be where the better kinematics line up and wind shear.
Currently the central and southern plains from northern Texas to
central Kansas have a more consistent signal amongst ensemble
members for active parameters, with fewer members supporting it as
you head eastward away from there. The other question for area will
be how much moisture return can we realize prior to the forcing
moving into our area. In addition, the weekend`s preceding ridge and
strong southwesterly flow likely leaves a stout EML in place for
eastern Kansas to central Missouri, leading to higher potential for
a strong cap to be in place. However, if a deterministic ECMWF track
is realized with the system, that forcing and overall kinematic
field would likely be able to overcome any capping issues. This
potential has been highlighted in the SPC Outlooks that cover the
Days 4-8 periods. The 04/11/2024 update is not yet out at the time
of this discussion yet, but the 4/10/2024 Day 6 outlook highlights
this potential and uncertainty with the location of best forcing,
especially the eastward areal extent.

Through the middle of next week, another short-wave trough may track
behind the Monday-Tuesday system that could bring more precipitation
into portions of Wednesday and Thursday. However, this will largely
depend on how the preceding system evolves, and how the previous
weekends omega block pattern breaks down.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1225 AM CDT Thu Apr 11 2024

Cloud cover will be around area through at least late morning,
and could linger into the early afternoon hours of the KC metro
terminals. Most of the shower activity should be east to the
area. Winds will pickup through the day, and may see gusts
between 25 and 30 kts. Ceilings and visibility conditions
should remain VFR.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...None.
KS...None.

&&

$$

DISCUSSION...Krull
AVIATION...Krull