595
FXUS63 KLSX 301734
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1234 PM CDT Sat May 30 2026

.KEY MESSAGES...

- There will be several rounds of showers and scattered thunderstorms
  through Monday before drier weather is expected next week.

- High temperatures are expected to mainly be in the 80s.


&&

.SHORT TERM...  (Through Late Sunday Afternoon)
Issued at 323 AM CDT Sat May 30 2026

Surface winds were calm or very light over the area early this
morning to the north of a stationary front extending from the Mid
South into the Central Plains.  Low clouds and patchy fog with
visibilities below 1 mile have developed across parts of central and
southern Missouri.  HREF probabilities is showing that this same
area having >50% chance <1/4 mile visibilities between 4-8 am, so
will need to watch visibilities trends the next few hours for the
need of an advisory.

Water vapor imagery is showing a weakening upper trough along the
Mississippi River with a trough over the central Plains.  While the
first trough will continue to weaken and move off to the east this
morning, the band of low level convergence that has been across
southeast and central Missouri since yesterday will remain quasi-
stationary through tonight. RAP soundings are showing MLCAPES around
1500 J/kg with weak deep layer shear so I couldn`t rule out a few
storms producing small hail and gusty winds today. PWATS are around
1.9" with warm cloud depths above 10,000 feet, so locally heavy
rainfall will also be possible.

This activity will likely die down this evening but then pick up
again overnight as thunderstorms that develop over eastern Kansas
and western Missouri later today will move into central and
northeast Missouri after midnight.  Chances over this area will
initially be in the 40-60% range through early Sunday morning but
will fall off by late morning and Sunday afternoon as it moves east
of persistent area of convergence and instability.

Britt

&&

.LONG TERM...  (Sunday Night through Friday)
Issued at 323 AM CDT Sat May 30 2026

Model guidance has been consistent and is showing the upper flow
turning northwesterly and eventually northerly early next week as
the trough deepens over the East Coast.   The LREF is still showing
40-70% of is members producing rain over the CWA late on Sunday
night, likely as a shortwave trough or MCS moves southeast through
the area. The NAM/GFS is showing MLCAPES of around 1000 J/kg with
deep layer shear around 35 knots supporting a few strong storms
overnight along with the possibility for locally heavy rainfall. The
LREF has 30-50% of it members still producing rain into Monday
morning before mainly dry weather is expected on the backside of the
trough through Thursday.  High temperatures will be mainly in the
80s

Britt

&&

.AVIATION...  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1229 PM CDT Sat May 30 2026

Showers and thunderstorms are in the process of exiting the
central Missouri sites, but additional activity will be developing
downstream. The coverage of these showers/weak thunderstorms
should be scattered, so kept PROB30 mentions. Any terminal that
does directly get impacted may see visibilities briefly reduce.
Mostly dry weather is forecast this evening/overnight, but another
area of showers and storms may threaten central Missouri and KUIN
sites Sunday morning. There was enough uncertainty to not prevail
thunderstorms given differences in timing/track, so have a PROB30.

Gosselin

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$

WFO LSX