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000
FXUS63 KEAX 091100
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
600 AM CDT Tue Apr 9 2024

.KEY MESSAGES...

- Temperatures Generally Above Normal This Week

- Rain Showers For Southeastern Two-Thirds of CWA Wed-Thurs.

- Very Warm Weekend Possible

&&

.DISCUSSION...
Issued at 255 AM CDT Tue Apr 9 2024

Two main features are controlling the weather pattern this morning
across much of the central CONUS. There is a an upper-level closed
low system over the western Great Lakes that will be lifting
northward into Canada later this afternoon. There is a deep H5
trough axis over the desert southwest that has been providing strong
southwesterly flow from the TX/OK Panhandle into the lower Missouri
River Valley. Behind the closed-low system north of our area is a
weak H5 ridge axis that has been working to push a surface
anticyclone into the Central Plains, which has also been pushing a
cold front southward across the forecast area overnight. This has
been competing with a surface cyclone in west Texas that has been
developing in response to stronger dCVA ahead of the trough axis.
Currently an inverted surface trough extends to the southwestern
Ozarks ahead of this system but has not yet provided much forcing in
our area. Higher-level cirrus clouds have been filtering in ahead of
this system over the past 12 hours. Through the rest of the morning,
expecting the cold front to push a bit further southeast into our
forecast area as the ridge axis over the Northern High Plains
attempts to shift eastward. However the lifting H5 trough over the
desert southwest will begin to stall its southeastward progress. With
the surface anticyclone dropping southward, low-level flow will
eventually shift from the east-northeast, limiting moisture
transport into the region. Therefore, will hold off precipitation
potential for most of this afternoon. The surface cyclone over west
Texas begins to lift eastward as the trough axis also lifts
northeastward. By late afternoon to early evening, this should stall
the cold front roughly along the Interstate 44 corridor. Most of
area will be on the cooler side of this boundary, but as long as the
cloud cover remains thin, there should be enough insolation to help
keep temperatures in the upper 60s across a large portion of the
area. Current inner-quartile spread amongst NBM members is between
67 and 71 degrees for most points in eastern Kansas to Central
Missouri. With the thermal boundary expected to push south of our
area, thinking temperatures right around the 50th percentile should
be a realistic forecast. As the low continues to push northward
against the stalled boundary, low-level convergence increases in
southern Missouri and should start to produce light rain activity in
southern Missouri but the surface anti-cyclone over the Central
Plains will help to keep our area dry. Through Tuesday, most
ensemble suites hold a less than 10 percent chance for
precipitation.

Wednesday morning, H5 trough axis sweeps across Texas. Strong dCVA
into eastern Oklahoma and western Arkansas will continue to deepen
the surface cyclone with surface troughing extending into the middle
Mississippi River Valley. This will begin to push the thermal
boundary back northward. Low-level flow turns more southerly
Wednesday morning and should provide better moisture transport from
far eastern Kansas into Central Missouri. Rain shower activity
slowly pushes toward the Interstate 70 corridor and convergence
along our eastern counties should push light rain along the Hwy. 63
corridor through the early afternoon. Ensemble probabilities for at
measurable rain increase to between 40 and 50 percent for our
northern counties and around 70 percent toward the south. This
convergence along the thermal boundary continues into Thursday
morning, with precipitation finally winding down Thursday afternoon
and pushing eastward. The QPF max axis currently sits southeast of
our forecast area where the stronger mid-level vort max will be
located along with better kinematics. Current ensemble means for
areas along the Interstate 44 corridor are around 1.1 inches. For
our area, ensemble means are generally between 0.10 and 0.25 inches
for Kansas City to Kirksville, and 0.25 to 0.50 inches from Bates
County MO over to Pettis County MO. Mean values are lower for the
northwestern third of our forecast area, though will note with
latest ensemble suites have seen a slight uptick in probabilities
for light rain for far northwest Missouri and northeast Kansas. NBM
has also picked up on this trend, and have pulled the POPs for
Wednesday a bit further north based on 06z CAM guidance, mainly the
HRRR, indicating showers traveling northward of Hwy. 36. The main
limiting factor for heavier rainfall in our area will be the lack
instability, which is currently progged to remain across the lower
Mississippi River Valley and the Gulf Coast. Therefore, the current
mode of precipitation for Wednesday into Thursday will mainly be
general showers. However, if a stronger push of theta-e can work
northward, perhaps a narrow instability axis could develop that
would support a few rumbles of thunder but is currently not favored
in deterministic nor ensemble guidance. Temperatures for Wednesday
will generally be in the upper 60s. Cloud cover will be the large
limiting factor to temperatures on Wednesday. By Thursday morning,
the bulk of the vorticity with the 500mb trough becomes wrapped
around the system as it becomes vertically stacked. Current
deterministic model solutions show a large amount of wrap around
moisture that will continue to provide shower activity primarily for
the eastern third of our forecast area through the early morning
hours on Thursday. A weak short-wave trough to the north will help
to keep enough flow on the backside that will allow the system to
move east of the Mississippi River Valley by Thursday afternoon and
should be able to push the thermal boundary out of the area. Rain
showers should exit with the thermal boundary leaving the area
Thursday afternoon. Strong pressure gradient on the backside of the
system will lead to gusty winds Thursday into Friday.

Amplified ridge axis shifts eastward Thursday Night into Friday,
which will provide an AVA regime heading into the end of the work
week across our forecast area. Lingering cloud cover on the backside
of the exiting system will keep temperatures cooler on Thursday
afternoon but should give way to clear skies with subsidence by
Friday. Thermal ridge axis continues to advance eastward through
Friday, with mid-level short-wave trough over the Baja Peninsula
driving southwesterly flow ahead of the ridge axis and promoting a
robust WAA regime, along with stronger insolation. Heading into the
weekend, this will result in well above normal temperatures for this
time of year. Current ensemble means this weekend for afternoon
highs are in the lower to mid 80s. For Saturday and Sunday, there is
not much spread for inner-quartile ranges amongst the NBM members,
thus is a rather robust signal for very warm conditions heading into
the weekend. Currently, there does not appear to be much moisture
return as this push of WAA occurs, thus limiting precipitation
chances over the weekend. Most ensemble suites hold less than a 10
percent chance for any precipitation over the weekend. For the start
of the next work week, there is a signal for troughing over the
western CONUS, but medium range solutions greatly diverge in how
active southwesterly mid-level flow becomes for the start of next
week. If conditions remain dry, extremely warm temperatures could
continue. But the flow is more active and is able to produce thicker
cloud cover and precipitation, temperatures likely will be cooler.
Inner-quartile values for temperatures amongst various ensemble
system next week have as much as a 15 degree spread for many points
across our forecast area.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 600 AM CDT Tue Apr 9 2024

VFR conds will prevail thru the TAF pd with varying covg of high
clouds thru this TAF cycle. Winds will be out of NNW btn 5-10kts
thru 23Z-01Z when winds will become lgt and vrb.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...73