869
FXUS63 KEAX 161733
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1233 PM CDT Tue Jul 16 2024

.KEY MESSAGES...

- Chances of thunderstorms today as a cold front/outflow
  boundary drops south through the region. Timing of
  precipitation is very difficult, but if storms are able to
  develop, a few could be strong producing gusty winds.

- Much cooler and drier condition are expected Wednesday into Friday
  as Canadian high pressure builds into the Upper Midwest.

- Chances of storms return to the region this weekend as a series of
  disturbances funnel into the Upper Midwest.

&&

.DISCUSSION...
Issued at 344 AM CDT Tue Jul 16 2024

Complex set up today with relatively zonal flow across the
lower 48, but jet speed max rounding the base of the upper level
trough over the Hudson Bay will enhance upper level lift later
today into tomorrow evening. At the surface, outflow boundary
extending from MCS that raked across Iowa into Illinois is
situated just south of highway 36. Clouds are bubbling along
this front trying to initiate convection, but cap remains in
place with roughly 100 J/kg of cin remaining lifting 925-850 mb.
HRRR and RRFS have been trending lower on convective chances
prior to 12Z through the night. Initially, solutions suggested
that convection would try to develop along this boundary between
06-09Z, but cap may just be too much to overcome.

Outflow boundary/cold front is expected to sag southward through the
day as area of low pressure across central KS as of 08Z moves east.
As this area of low pressure approaches, expect to see the cap
weaken further and could see shower and thunderstorm development in
eastern KS toward 15Z spread east across the region. Greatest
instability and precipitable water will be confined to areas along
and south of the front, where SB CAPE values of 3-4K are possible.
Precipitable water is 2-2.25" along and south of the boundary, so if
a storm is able to develop, it would likely be a very efficient storm
with deep warm cloud rain processes. Effective shear is generally in
the 25-35 knot range with the greatest shear behind the front, so
a few storms may organize enough to be strong-severe.

The surface boundary is expected to work into central Missouri by
early this evening, but moisture lags behind the front with a
modicum amount of instability lingering.  It is possible a storm or
two could develop within the right rear quadrant of the upper level
jet, though there is no real obvious mechanism to focus
precipitation chances on.

Drier and cooler air filters into the lower 48 as Canadian high
pressure builds into the Upper Midwest and remains through the
weekend resulting in cooler and drier conditions. A few ridge riding
short waves are forecast late this week into the weekend to drop
into the Midwest under amplified NW flow as ridge builds out west.
Could see additional storms this weekend with these features, but
are ill-timed in the solutions at this point.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1224 PM CDT Tue Jul 16 2024

Storms have moved well east of the terminals, and subsequent
convection is expected to stay south and east of the KC metro.
Therefore, expecting VFR and precip-free conditions for the next
24 hours. Winds will become predominantly northeast 5 to 10 kt
this afternoon, before transitioning to light and variable
overnight. There is around a 20 percent chance of sub-VFR
CIGs/VSBYs around 12z, but these probabilities are too low for
any TAF inclusion at this time. Exception is at STJ, where
confidence in fog is higher in the couple hours surrounding
sunrise.

&&

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

&&

$$

DISCUSSION...BT
AVIATION...CMS