735
FXUS63 KEAX 290759
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
259 AM CDT Mon Apr 29 2024

.KEY MESSAGES...

- Quiet, seasonal weather conditions for Monday and Monday night.

- Strong to severe storms possible Tuesday afternoon and evening.

- Active weather pattern continues through at least Thursday
  night, with a lull possible Friday into Saturday. This could
  aggravate ongoing flooding concerns across the area.

&&

.DISCUSSION...
Issued at 259 AM CDT Mon Apr 29 2024

Surface analysis at 2 am shows the cold front splitting the forecast
area generally north to south, east of I-35. This front will
continue to move east and should be east of the forecast area by
12Z. There will be a few showers and possibly a thunderstorm
along the front as it moves east in the predawn hours. A cooler
and less humid airmass will move into the region behind the
front and give the area seasonal temperatures with dry
conditions. Highs today should range from the upper 60s across
northern MO to the middle 70s south of Highway 50.

This dry and seasonal weather will be short-lived as the surface
shifts into the Southeast by Tuesday afternoon. With lee troughing in
the High Plains, a tighter pressure gradient develops across the
central to eastern Plains. This allows for southerly flow to develop
and moisture, which wasn`t displaced that far south to begin with,
surges northward. In the mid and upper-levels, a strong shortwave
trough will eject into the central Plains and push a cold front
eastward across Nebraska and Kansas. This helps tighten the pressure
gradient further and by the afternoon we should be seeing wind gusts
of 30-35 mph across eastern KS and western MO. The return of
moisture and temperatures climbing into the lower to middle 80s will
help build modest instability across eastern KS and western MO.
HREF probabilities show a 70+ chance of greater than 1000 J/kg
of surface based CAPE. These percentages drop off at 2000 J/kg
so eastern KS and western MO will likely end up in the 1000-2000
J/kg range for SBCAPE as the front is moving into the area.
There`s also a high probability of effective shear between 30-40
kts with it`s orientation nearly orthogonal to the cold front.
This will favor the potential for supercells with large hail,
damaging winds and a tornado or two. The greatest area looks to
be from far northwest MO in eastern KS and west central MO.

With the strongest forcing associated with the shortwave trough
passing north of the area, the southward push of the front dies and
the front stalls in the vicinity of the forecast area. Models vary
significantly with this but the consensus is generally in our south
or possibly just south of the forecast area. As the next shortwave
digs into the Four-Corners region, southerly flow increases and
pushes the front north again as a warm front. Convection may be
ongoing Wednesday as the warm front lifts into Northern MO or just
north of the area. This warm and moist low-level pattern leads to
moderate instability with the area likely to see 2000-3000 J/kg of
CAPE by Wednesday afternoon. This could be lower if convection and
cloud cover are more widespread. Wednesday evening, a strong low-
level jet develops and noses into the boundary. As a result,
the coverage of showers and storms become more widespread after
sunset Wednesday evening. The focus of this round of convection
looks to be across northwestern to northern MO, in the vicinity
of the front.

For Thursday, a strong shortwave trough will move into the
northern Plains and push the front southward as a cold front.
Instability will be more uncertain depending on how the
Wednesday night/ Thursday AM convection evolves. But if the area
does recover from that earlier activity, we should be the
right-rear quadrant of the upper jet with stronger mid to upper-
level flow leading to stronger shear. So there is a more
conditional risk of severe weather Thursday depending on how the
area destabilizes from the earlier convection.

Similar to today, a cooler and drier airmass moves into the region
Friday. That should lead to a period of quieter weather before the
moisture recovers. Models show the high shifting into the Southeast
with southerly flow returning, allowing moisture to return to the
area late in the weekend and into next week. Models vary on the
pattern more for this time frame so confidence is lower on any one
day being more likely than another for rainfall. This results in a
broad brushing of lower PoPs for Sunday and Monday.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 1155 PM CDT Sun Apr 28 2024

A cold front moved through the terminals in the last 1-2 hours.
This will lead to light westerly winds and drier air moving into
eastern KS and western MO, which will result in VFR conditions
through the forecast.

&&

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

&&

$$

DISCUSSION...CDB
AVIATION...CDB