354
FXUS63 KEAX 061934
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
Issued by National Weather Service Topeka KS
234 PM CDT Thu Jun 6 2024

.KEY MESSAGES...

- Showers and thunderstorms are likely (50 to 70 percent) Friday
  night into Sat. morning. Locally heavy rain and perhaps some
  large hail could be a problem.

- A second round of heavy rain is possible (40 to 70 percent)
  Saturday night. This rain should be shifted south but may
  still lead to flooding issues.

- Mild temperatures with mainly dry conditions are forecast to
  begin next week.

&&

.DISCUSSION...
Issued at 234 PM CDT Thu Jun 6 2024

19Z water vapor imagery showed an upper trough axis from the
great lakes into northern Alberta with a modest upper ridge over
the southwestern U.S. This has lead to northwest flow through
the middle and lower MO river valley. The weak isentropic
upglide had shifted south of the forecast area with sunny skies
across northern and central MO. At the surface weak high
pressure was nosing into southwest MO with some dry air
advecting into northern MO.

This high pressure is forecast to remain over the MO and KS state
line into Friday morning leading to clear skies and light winds
helping lows to fall back into the middle and upper 50s. The main
focus of the forecast is the developing return flow Friday night
night. 12Z models continue to show strong theta-e and moisture
advection with the latest runs shifting the nose of the low level
jet into northwest MO. This in turn has caused the track of the
possible MCS to shift north from previous solutions. The NBM still
shows pretty high probabilities for precip, but given the
variability in the placement of the MCS, have opted to keep POPs in
the 60 to 70 percent range for now. With models showing PWs
increasing to around 2 inches, areas within the path of the MCS
could pick up an inch or two of rain. But again the predictability
of where the rainfall may occur is to low to say with much
confidence where the heavy rain will set up. Forecast soundings also
show elevated instability with CAPE values between 1000 and 2000
J/kg depending on which model you look at. 0-6km shear is progged to
be plenty strong enough for organized updrafts so in addition to the
heavy rain risk, there could be some risk for large hail and strong
wind gusts with the storms.

A frontal boundary/outflow from the MCS Saturday morning is progged
to set up over southwestern MO and southeastern KS Saturday
afternoon. This could act as a focus for redevelopment of showers
and thunderstorms into Saturday evening and POPs have been increased
because of this. Models continue to show a fair amount of moisture
along this boundary and the mean flow looks to be a little more
parallel to the boundary that could aid in training storms. So a
second round of heavy rain is possible Saturday night into Sunday
morning. Fortunately this second round of rain should be displaced
further south from the Friday night rain. Still there could be some
local flooding issue develop by Sunday morning.

The forecast for next week looks to be a little more nuanced
depending on where and when shortwaves may move through within an
overall northwest flow pattern. With the operational runs of the GFS
and ECMWF showing low continuity with these smaller scale features,
the spread in possible outcomes in higher than normal and
predictability is lower. So have kept the blend forecast from the
NBM as it is a good first iteration to the forecast.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1201 PM CDT Thu Jun 6 2024

Weak surface ridging with relatively dry air over the region is
expected to keep VFR conditions in place. Winds will become
light and variable towards sunset and then pick up after sunrise
Friday from the south and southwest.

&&

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

&&

$$

DISCUSSION...Wolters
AVIATION...Wolters