863
FXUS63 KEAX 080855
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
355 AM CDT Tue Jul 8 2025

.KEY MESSAGES...

- Stratiform Showers Through This Morning

- Outflow Boundaries May Initiate New Convection This Afternoon In
  Central Missouri, Depending on Recovery

- Drier Wednesday; Active Toward End of Week

&&

.DISCUSSION...
Issued at 355 AM CDT Tue Jul 8 2025

Thermal boundary from south of Omaha to near Kansas City has pushed
a bit further eastward, but overnight this generated a CAPE gradient
that helped keep the MCS over eastern Nebraska going for a longer
period of time, even when it became outflow dominant. Finally as of
08z, seeing a substantial downward trend in the stronger
precipitation cores. There is not much deep layer shear to support
it, and finally appears to be cut-off from the instability it could
draw in overnight. Expansive trailing stratiform rain shield has
developed across most of the forecast area, and should persist
through most of the morning. Eventually should see H5 short-wave
exit, and subsidence start to clear this out by late morning.

With this MCS holding together further southeast than yesterday`s
CAMs runs had projected, the mesoscale environment has been and will
continue to altered substantially past sunrise this morning. The main
question, is where does the outflow boundary stall. A few runs after
06z this morning of the HRRR has placed this outflow from Linn
County Kansas east-northeastward toward Howard and Cooper Counties
Missouri. That then initializes new convection around 21-22z, which
would align with peak heating. Another mid-level vort maxima will be
moving across the region at some point this afternoon, with
potential for that to induce surface pressure falls from the Central
Plains to the middle Mississippi Valley. If these come together
between 18-22z this afternoon, and there is enough destabilization
in this zone of convergence, stronger thunderstorms could be
favorable. Main threat would be severe wind gusts. As has been the
story for most of the activity over the past several days, the deep
layer shear has been weak, thus hard for updrafts to organize when
they initiate over Missouri. If convection develops, most of this
should push southeastward toward the Ozarks through the remainder of
the evening. Have concentrated POPs mainly south of Interstate 70
for this afternoon. If the outflow boundary pushes further
southeastward and stratiform shield lingers long enough to prevent
insolation, our forecast area may see very little in the way of new
development. The SPC SWODY1 marginal risk for winds is conditional
on initiation of storms this afternoon.

Wednesday, deterministic guidance has started to depict a subtle
eastward shift of the broad anticyclone over the southwest CONUS,
that may actually introduce H5 height rises and broader subsidence,
pushing short-wave activity further eastward. As a result,
precipitation chances for most of Wednesday have been on a downward
trend compared to previous forecasts. GEFS and other ensemble suites
are showing decreasing probabilities for 0.10 inch of QPF on
Wednesday. It still appears that a higher theta-e boundary layer may
be in place though, so if there is any destabilization cannot
completely rule out a few isolated showers to initiate within a
cumulus field. Temperatures will still be in the upper 80s to lower
90s, with dewpoints generally in the mid 60s to lower 70s. Thursday,
stronger PV anomaly promotes troughing over the western CONUS that
will begin to de-amplify the ridge. Stronger dCVA into the Front
Range begins to promote lee cyclogenesis, with pressure falls
extending eastward across the Plains. Thursday afternoon, this may
increase convergence, and even provide a mid-level vort maxima to
generate isolated to scattered thunderstorm activity. We may start
to see an increase in deep layer shear by Thursday, which may allow
for better organization of storms if they are able to develop. SPC
SWODY3 currently highlights this with a marginal risk.

Stronger mid-level vort maxima is progged to move through Friday
into Saturday, capable of bringing more widespread shower and
thunderstorm activity heading into the weekend. Deep layer shear
should be much greater, as stronger mid-level jet streak moves
overhead. The main question for Friday and Saturday activity is
where will the better surface forcing be located at, that could end
up being the controlling factor for stronger to severe storms. QPF
may also need to be monitored closely for hydro related issues
headed into the weekend. Slightly cooler air settles in Saturday
into Sunday, with high temperatures forecast in the upper 70s to
lower 80s.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1219 AM CDT Tue Jul 8 2025

Watching organized thunderstorm complex move southeast out of
Nebraska. Although decaying, heavier shower activity is
expected. Heavier shower activity should reach STJ between 0630z
and 0700z. Will continue to monitor lightning trends to
determine if thunder reaches STJ. Less confidence in westward
extent of the complex, therefore a bit more uncertain with the
KC metro terminals. Timing out the line, if it holds together,
will arrive at MCI between 07z and 08z, and then IXD about an
hour later. For now, will place TSRA in a PROB30 group for the
KC metro terminals. Weaker shower activity may develop behind
that between 11-13z. Heavier precipitation expected across
Central Missouri through the morning hours. Redevelopment of
storms over Central Missouri may be possible on Tuesday
afternoon, but will need to watch how current activity modifies
the environment. If the environment remains too stable, better
precipitation chances may push more into southern and
southeastern Missouri for Tuesday afternoon. Expecting mostly
VFR conditions, though brief MVFR ceilings are possible. If a
downpour occurs at the terminals, may see a few minutes of IFR
visibility. Wind gusts with decaying showers may reach between
25-35kts.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...Krull