930
FXUS63 KEAX 050529
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1229 AM CDT Fri Jul 5 2024

.KEY MESSAGES...

- Storm Chances Drastically Decreased For This Evening

- Seasonable Temperatures Through Weekend

- More Precipitation End of Weekend

&&

.DISCUSSION...
Issued at 257 PM CDT Thu Jul 4 2024

H5 trough axis is currently moving across the Central Plains this
afternoon with several vort maxes and perturbations moving ahead of
that into the lower Missouri River Valley. The first thermal
boundary has been nudged southward into Ozarks, mainly forced by the
convection early this morning. As a result of that, a lot of the
instability that was expected to be around was pushed well south of
Interstate 70, and prevented a lot redevelopment through the late
morning hours despite larger scale lift with the passing mid-level
short-waves. Also, the dCVA associated with the troughing over the
Plains and subtle dCVA ahead of it pushed surface pressure falls and
cyclogenesis processes further south for this afternoon. There is
still a trailing cold front, which is more of a dewpoint
discontinuity then a true temperature one at this point, that is
coming in from Kansas. This front had been the focus for
redevelopment this afternoon. However, with the cloud clover
lingering, differential heating was not strong in our forecast area,
and was forced into the Ozarks and portions of the Ohio River
Valley. As of 19z, there were still some cumulus clouds in eastern
Kansas ahead of the cold front but little in the way of any
glaciation or rapid cloud top cooling. The lack of instability and
weaker convergence has been the reason for decreasing precipitation
trends through the afternoon. As of the 16z cycle, the HRRR
completely eliminated most convection, with simulated reflectivity
fields showing a few isolated showers. While there is still a decent
amount of shear along the front and in the presence of the mid-level
vort maxes, the thermodynamics and low-level convergence just is not
there anymore to realize any kind of severe threat. Given that the
cold front is still coming in, will leave some mentionable POPs in
the forecast to cover light shower activity. There may be some
elevated instability that perhaps an isolated thunderstorm could
develop with and produce some lightning, but the probabilities for
even general non-severe thunderstorms have rapidly dwindled in the
past few hours. With that being said, expecting mostly dry
conditions for the rest of your Independence Day evening. Keep in
mind several creeks and streams are still running high, and we may
still have standing water in some low lying areas. For right now,
will keep the Flood Watch out in case any showers do develop along
the front, and will gradually cancel the flood watch as the cold
front moves across the forecast area through the evening. But
overall QPF values look to be less than 0.25 inches at this point.
Overall, winds will be light in variable as the front passes,
eventually becoming more northerly. A weak inversion may setup post-
frontal as a surface anti-cyclone moves into the area, which may
make the air a bit stagnant this evening. Keep this in mind for any
4th of July celebrations.

Closed H5 low drops into Iowa by Friday morning which will maintain
some H5 height falls in our area, but stronger surface anti-cyclone
developing under subsidence in the central Plains slides eastward
underneath that, and largely eliminates most of the forcing keeping
a rather dry forecast for our area on Friday. There is a weak signal
for light QPF in our far north with some moisture wrap around Friday
afternoon, but the bulk of the forcing and better belt of moisture
transport will be in the upper Mississippi River Valley. The
presence of the mid-level low will help keep temperatures bit cooler
and reduce influences from the ridge trying to build over the
Central Plains. Another short-wave trough begins to dig out of the
Rockies late Saturday afternoon, that will provide a brief period of
height rises across our area and may provide better theta-e
advection heading into the late evening hours. The main vort max
associated with this then moves over the forecast by middle of the
day Sunday and will bring rain shower and thunderstorm chances.
Current GEFS and other medium range ensemble suites paint
probabilities above 70 percent across a large portion of the
forecast area for QPF of at least 0.10 inches, and lower end
probabilities between 20 and 30 percent for at least 0.50 inches of
QPF Sunday into Monday. Still some uncertainty with where the better
instability axis sets up for the weekend, with some solutions
placing this over the Central Plains and others closer to the
Mississippi River Valley. Therefore, difficult to comment on severe
convection potential for Sunday and Monday at this time. There may
be some additional thunderstorm chances through the middle of next
week as few more short-wave perturbations moves across the area.
Temperatures generally will be in the upper 80s, with some lower 90s
possible. Amongst NBM members, inner-quartile spread is not overly
large, but you can see some uncertainty that is presented by shower
and thunderstorm through the middle of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1226 AM CDT Fri Jul 5 2024

VFR conditions are expected through the forecast. Light west-
northwesterly winds will increase slightly during the day and
trend to the northwest. A few gusts into the low 20kt range look
possible. It also looks like we`ll see scattered diurnal CU.
Winds weaken and skies clear after 00Z.

&&

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

&&

$$

DISCUSSION...Krull
AVIATION...CDB