343
FXUS63 KEAX 061143
AFDEAX

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
643 AM CDT Mon May 6 2024

.KEY MESSAGES...

- Severe weather expected tonight as squalline moves through the
region. Strong straight-line winds and brief tornado are expected to
be the main severe hazards tonight.

- Visibility associated with dense fog this morning is expected to
improve by late morning.

- Additional severe weather possible Wednesday afternoon with large
hail and damaging winds being the main threats.

&&

.DISCUSSION...
Issued at 403 AM CDT Mon May 6 2024

Active weather picture today with significant outbreak of severe
weather expected across the central and southern plains today with
strong upper low exiting the four corners region building into the
central plains.

As of 08Z... Complex of storms associated with a
departing upper low across southeastern Missouri building east into
the Tennessee Valley. Lingering low level moisture from the
departing system leading to some fog across the region. Dense fog
has begun to develop across eastern Kansas into western Missouri.
Models suggest this will likely expand prior to sunrise, and have
coordinated a dense fog advisory with neighboring offices for the KC
metro and areas south and west.  There is the potential dense fog
advisory may need to be expanded farther north, but with less
moisture, confidence is not as high and have left these locations
out of the advisory for the time being.

For today, the strong upper trough across the four corners region is
expected to lift northeast towards the Central Plains.  Warm sector
is expected to expand today as warm front lifts north/east across
the central plains.  North of the warm front, easterly wind and
stratus will be fairly prevalent. Have shaved expectations for
forecast highs today, but think there could be a late day surge of
warming especially south of the warm front.  CAMs suggest storms
could develop as early as 15-16 Z across southern Nebraska/northern
Kansas along a dry line. These storms are expected to develop in a
strongly sheared environment, with effective shear of 40-45 knots.
These storms will continue to build farther east through the
afternoon hours feeding off increasing instability farther east.

Thunderstorms are expected to develop into a squalline, shifting
into the immediate region after 00Z tonight. Strongly sheared
environment with bulk shear values of 30-40 knots and MU CAPE values
of 1500-2000 J/kg will continue to support squalline across the
region. With the strong shear, potential for embedded supercells
within the line to lead to enhanced areas of severe weather.
Downdraft CAPE across the region remains a widespread 1-2K
suggesting the potential of strong damaging winds with the line as
it works into the region.  The line appears to be fairly progressive
potentially limiting the flash flood potential, but with mature MCS
including large trailing stratiform region, could see rainfall
amounts of 1-2". With lowered flash flood guidance given the wet
antecedent conditions, could see some renewed flood threats
overnight.

Clearing skies are expected behind the complex of storms overnight
leading to a much quieter day across the region on Tuesday. However,
the upper trough across the western US is expected to lift into the
northern US where it remains cutoff from the upper flow. A strong
short wave wrapping around the low is expected to rotate into the
region on Wednesday afternoon leading to a renewed threat of
thunderstorms across the region. While low level moisture looks to
be somewhat limited ahead of the meso-low, could see surface dew
points approach 60 degrees and CAPE values approach 1000 J/kg.  With
strongly sheared environment, could see storms develop that would be
capable of damaging winds and large hail.

Late this week, the upper trough gradually finds its way to the east
with north/northwesterly flow prevailing leading to cooler and drier
conditions across the region.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 637 AM CDT Mon May 6 2024

Fog continues at the terminals this morning, with VSBYs ranging
from quarter mile at IXD to 3SM at MKC and STJ with LIFR CIGs.
Conditions should improve to MVFR by around 14z to 15z this
morning.

A line of strong to severe storms should overspread the
terminals from the west around 3z tonight. The leading edge of
this line will produce very heavy rain, reducing VSBY to 2SM or
lower, with thunderstorm wind gusts out of the WSW up to 60 mph
(or perhaps even higher). Later TAF issuances will likely need
to handle these short term 60 mph thunderstorm wind gusts with a
TEMPO group once it becomes within the 9 hour range. Moderate
rain with occasional thunder will likely continue from around
4z to 7z tonight, after which storms should exit to the east,
with VFR conditions returning.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...Dense Fog Advisory until 9 AM CDT this morning for MOZ028-029-
     037-043-053.
KS...Dense Fog Advisory until 9 AM CDT this morning for KSZ057-060-
     103>105.

&&

$$

DISCUSSION...BT
AVIATION...BMW