459
FXUS63 KEAX 201936
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
236 PM CDT Thu Jun 20 2024

.KEY MESSAGES...

- Pulse showers and thunderstorms are expected this afternoon
  and evening along a boundary generally extending along I-35
  across the KC metro through Schuyler County MO. No severe
  weather is anticipated and storms should conclude after
  sunset.

- Temperatures continue to warm through the weekend with heat
  index values surpassing 100F starting Saturday.

- Heat indices continue to climb early next week reaching
  100-105F. Overnight lows range between 70-75F bringing little
  nocturnal relief from the heat.

&&

.DISCUSSION...
Issued at 236 PM CDT Thu Jun 20 2024

Winds have shifted back from the south signaling the start of the
warming trend that continues through next week. The subtle frontal
boundary that brought scattered showers and storms around the region
early this morning has lifted slightly northward allowing everyone
to bask in the warm air and moisture ascending from the Gulf Coast.
Highs elevate towards 90 degrees today with dew points around 70F.
As southerly flow moves across this boundary, now oriented from the
KC metro northeast into Schuyler County, showers and isolated
thunderstorms are developing. These pulse storms are expected to
remain sub severe; however, heavy downpours are possible given the
ample moisture within atmosphere. Pop-up storm chances are expected
to continue through sunset.

Temperatures continue to slowly climb through the day tomorrow with
highs in the low to mid 90s. Saturday and Sunday look to be the
first time that heat index values crest 100F. The slow ascent of
temperatures continues into early next week where heat index values
range from 100-110F with the higher values further south. Overnight
lows early next week barely touch the mid-70s which prompts the
considerations for heat advisories or an excessive heat warning
during the time period.

The primary culprit for this heat is a stout high pressure system
transiting across the country. This high pressure has been sitting
over the eastern CONUS for the past several days. It has been
contributing both to the influx of heat and humidity into the region
as well as the passing shortwaves which have brought the
precipitation seen over the past few days. This high finally starts
moving although instead of moving from west to east it retrogrades
east to west across the southern CONUS. As the system works its way
westward, it redistributes the upper level pattern deviating flow
north of the area. An upper level shortwave works its way across the
northern CONUS Saturday into Sunday attempting to push southward
into northern MO. This will bring a front as well as chances for
showers and storms mainly overnight Saturday into Sunday. So far the
most likely hazard with these storms is heavy rainfall and flooding
chances across northern MO as some places have received upwards of 4
inches of rain over the past 48 hours. Runoff and drainage
performance will need to be evaluated to determine the flooding
potential for later storms.

The high parks itself over the desert SW early next week. Normally,
upper level NW flow suggest calmer and drier conditions; however
guidance suggest this more opening up opportunities for
precipitation during the week. This is because lower level flow
maintains its southerly orientation continuing the push warm air and
moisture into the area with upper level shortwaves circulating the
high pressure creating a ring of fire setup. Unfortunately, most of
the precipitation chances seem confined to the overnight periods
which brings little relief to daytime heat. Long term guidance does
show a potential break in the heat wave as a high pressure works its
way out of interior Canada late next week. Unfortunately, guidance
has been quite variable in the extended ranges so much uncertainty
remains in the synoptic layout for late next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 101 PM CDT Thu Jun 20 2024

VFR conditions persist through the forecast period. Some diurnal CU and sporadic
showers continue through sunset. Winds remain light generally
out of the south.

&&

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

&&

$$

DISCUSSION...Pesel
AVIATION...Pesel