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447
FXUS63 KEAX 130841
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
341 AM CDT Thu Jun 13 2024

.KEY MESSAGES...

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- Heat and humidity continue today. High temperatures in the mid to
upper 90s with heat index values from 100-106F anticipated.

- The chance for strong to severe thunderstorms this evening
continues. The primary threats are for large to giant hail (2-4
inches), damaging winds, and heavy rainfall. The overall environment
remains volatile with outcomes ranging from sporadic strong/severe
storms to no storms at all.

- Storm chances persist through the weekend. Fortunately, most of
the precipitation looks concentrated to the overnight hours.

- Heat and humidity continue as high temperatures remain in the 90s
through next week.
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&&

.DISCUSSION...
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Issued at 340 AM CDT Thu Jun 13 2024

Wednesday was a little bit of a preview of what we are expecting to
happen today. Heat and humidity pushed into the region sending high
temperatures into the 90s with dew points just high enough to make
things feel a bit muggy. Outside of our area, isolated supercells in
eastern NE and IA dropped 2-3 inch hail under a somewhat similar
setup to what we are expecting for today.

Firstly, the temperatures, warm most air continues to flow into the
region. The primary axis of southerly flow has veered placing the
center of the warm air and moisture transport into our area. This
looks to push temperatures into the mid to upper 90s for most. It is
not implausible for some areas in far NE KS and NW MO to trifle with
100 degree air temperatures. Enhanced moisture flow raises dew
points across the region into the low 70s which will make it feel
quite muggy outside. SW winds gusting around 20-25 MPH will make it
feel a little more like a blast furnace than a refreshing breeze. A
Heat Advisory is in effect from 1 PM through 8 PM tonight. Please be
sure to practice heat safety including staying hydrated and checking
in on vulnerable neighbors and family members.

Secondly, chances for strong to severe thunderstorms Thursday
evening continues. The previously mentioned warm and moisture
transport creates a very unstable environment aloft. Model guidance
continues to suggest CAPE values in excess of 3000-4000 J/kg with
some outliers suggesting 5000-6000 J/kg possible. Enhanced by mid
level lapse rates in excess of 7-8 C/km creates an incredibly
volatile environment. However, the general lack of forcing and a
significant CAP could inhibit thunderstorm development. The primary
forcing mechanism is a combination of an upper level shortwave
combined with convergent high pressures at low to mid levels. This
creates a "cold" front that looks to enter into NW MO during the
late afternoon/evening hours. This enhances lift and creates a
vehicle to overcome the lower level inhibiting factors (such as the
CAP). While uncertainties continue, confidence is increasing that if
storms form, they will likely grow severe rather quickly dropping
large to possibly giant hail (2-4 inches), damaging winds, and heavy
rainfall. Convective variables at the lowest levels (0-1km) remain
somewhat weak limiting chances for tornadoes.

Expectations for tomorrow are similar to what played out across
eastern Nebraska lat night. A large supercell quickly matured
dropping 2-3 inch hail and damaging winds before rapidly dissipating
after sunset. Model guidance points to a similar chain of events;
however, coverage is expected to be a little more expansive across
northern MO. Storm mode could vary from none (due to capping), to
isolated robust supercells, to large scale strong to severe
thunderstorms complexes. Most CAMs point toward the second solution
with the NAMnest outlying with the 3rd solution. Where exactly
storms develop remains somewhat uncertain as the isolated coverage
make it difficult to pinpoint exactly where a storm will form.
Confidence is increasing in initial development across NE MO and
storms initiating southwestward along the front. This corroborates
with the northern portions of the Enhanced risk outlined by SPC.
Storms then migrate southeastward weakening after sunset. Some
thunderstorms may persist on residual elevated instability during
the first part of the overnight. Storm should peter out before 1 AM.

Surface high pressure settles in Friday. Originating from the north,
this does lower temps and dews Friday sinking values below 90 and 72
degree respectively. A robust shortwave works its way through the
area Friday night into Saturday bringing thunderstorm chances during
the overnight. Fortunately, this environment looks to be far less
tumultuous; however, and isolated strong to severe storm cannot be
ruled out. Intermittent storm chances return Saturday afternoon
through the overnight persisting into Sunday morning.

Somewhat fitting as the summer solstice approaches, the summer time
weather pattern of hot, humid air combined with multiple rounds of
showers and thunderstorms settles in. A strong high pressure over
the SE CONUS continues to route hot and humid air into the central
CONUS keeping highs int he 90s through the next 7 days. Embedded
trough and convergence along the 41st parallel keeps things active
which we will certainly take over the seasonal roasting climatically
common later in the summer.
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&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1237 AM CDT Thu Jun 13 2024

VFR conditions are expected for most of the daytime hours
tomorrow. Some diurnal CU and gusty SW winds precede developing
RA/TSRA during the evening. Several uncertainties remain as
storm development is expected to be sparse in coverage, at least
initially. Therefore, the broadscale timing of precipitation
potential has been outlined and will be refined in subsequent
forecasts.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory from 1 PM this afternoon to 8 PM CDT this
     evening for MOZ001-002-004-011>014-020>023-028>031-037-
     038-043.
KS...Heat Advisory from 1 PM this afternoon to 8 PM CDT this
     evening for KSZ025-057-060-102>105.

&&

$$

DISCUSSION...Pesel
AVIATION...Pesel