495
FXUS63 KEAX 110818 CCA
AFDEAX

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

.KEY MESSAGES...

- Multiple chances for showers and storms through end of the week
  with both diurnal and nocturnal convection possible.

- Trending hot and humid this weekend into early next week. Heat
  indices likely (>75%) above 100 and possibly (~20%) above 105.

- Active pattern returns mid to late next week with multiple
  chances for showers and storms.

&&

.DISCUSSION...
Issued at 316 AM CDT Thu Jul 11 2024

Ongoing convection, as of 08Z, looks like it is being caused by
isentropic ascent in the 305K to 310K levels with relatively strong
low-level winds and moisture transport intersecting a tight pressure
gradient over eastern KS and western MO. There also appears to be a
weak low-level boundary draped generally along I-70. This boundary
looks like it will linger in the area today and may provide enough
of a focus that isolated to scattered convection develops in the
afternoon heat. Which is somewhat concerning as models show
afternoon MLCAPE values again climbing into the 1500 to 2000
J/kg range within a marginally strong enough shear environment
of 20-30 kts. Forcing along this boundary, combined with the
strong instability and modest shear, may support another round
of strong to potentially severe storms this afternoon and this
evening. A nearly 5000 foot deep inverted V suggest good
potential for microbursts/ strong winds. Tonight, isentropic
ascent will develop again on the 305K and 310K levels. Like what
has been happening early this morning, this may lead to
isolated to scattered convection lingering into the overnight
hours. The threat of strong to severe weather looks lower
overnight due to CAPE decreasing with loss of daytime heating
and shear diminishing as well. For Friday, again it looks like a
weak boundary will be draped from northwestern MO to the
southeast. Strong diurnal heating of a very moist boundary layer
will result in afternoon MLCAPE values potentially in excess of
2000 J/kg. While shear looks weaker, forecast soundings show an
inverted V look and if convection can develop, looks like a
classic summertime microburst setup. Coverage of precipitation
looks more isolated but HREF probabilities of QPF >0.01 show
25-50% probabilities. With another two forecast cycles to fine
tune things, have just increased PoPs into the slight chance
range for now.

Heat and humidity will noticeably increase this weekend into early
next week. The upper ridge shifts eastward with its axis generally
along the High Plains. Strong southwesterly low-level flow will
help to push temperatures near 100 degrees Sunday and
potentially in excess of 100 degrees on Monday. In fact, the NBM
shows a 30-40% chance of high temperatures in excess of 100
degrees across eastern KS and western MO on Monday. This would
include the KC area. Additionally, overnight low temperatures,
particularly for the urban core of KC, look exceptionally warm.
The NBM shows a 30-50% chance for lows to be warmer than 80
degrees Monday morning. When combined with daytime heat, there
will be little to no relief from the heat.


This round of excessive heat looks short-lived, fortunately, as that
upper ridge is forecast to weaken and retrograde back to the western
US.  The tradeoff to that is that the pattern looks more active with
multiple rounds of storms possible in a broadly northwesterly flow
regime. That suppression of the ridge and retrograde to the west
allows for relatively stronger upper-level flow to move over
the area and models show a series of shortwaves moving through
the northwesterly flow. All this points to an active pattern for
the middle to later part of next weak.


&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1201 AM CDT Thu Jul 11 2024

VFR conditions should generally prevail. Scattered convection
may redevelop now through 12Z and impact terminal space. Current
wind field is quite variable, but should generally become
easterly by sunrise.

&&

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

&&

$$

DISCUSSION...CDB
AVIATION...Blair