Clarksburg, Missouri Weather Forecast Discussion

264
FXUS63 KLSX 241147
AFDLSX
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
647 AM CDT Wed Sep 24 2025
.KEY MESSAGES...
- Occasional rain with a few thunderstorms will continue today
  and this evening. Rain is expected to end overnight from
  northwest to southeast.
- Dry weather is forecast for the remainder of the forecast
  through next Tuesday. Temperatures will warm from near normal on
  Thursday to 5-10 degrees above normal by this weekend into early
  next week.
&&
.SHORT TERM...  (Through Late Tonight)
Issued at 323 AM CDT Wed Sep 24 2025
Water vapor imagery is showing dry air at mid and upper levels
this morning. This matches up well with ACARS and model soundings
at this time. The drier air aloft is causing a general lull in
shower activity, though low level moisture and some weak lift is
producing some very light rain or drizzle. Should see an uptick in
shower activity again late this morning into the afternoon and
evening as the synoptic short wave over the Great Plains moves
east into Missouri. This will bring mid-upper level moisture back
to the region and modest daytime heating will produce produce some
instability as well. The RAP is advertising as much as 1300-1500
J/Kg SBCAPE this afternoon for parts of the area, however this
continues to look a bit high as that amount of CAPE isn`t showing
up until the 90th percentile in the HREF. Regardless, any
thunderstorms that do develop won`t have a whole lot of
instability to work with and therefore shouldn`t be particularly
strong. P-wats remain relatively high around 1.6-1.8 inches and
warm cloud depths are also high up to around 3km so storms will
continue to be efficient rain producers. However, 24 hour QPE is
showing well under an inch across most of the area, so we should
still have plenty of capability to soak up more rain given the dry
conditions we`ve had leading up to this much needed rainfall.
Rain should end from northwest to southeast tonight as the short
wave digs farther into the Mississippi Valley and northerly low
level flow brings drier air into Missouri and Illinois.
Carney
&&
.LONG TERM...  (Thursday through Tuesday)
Issued at 323 AM CDT Wed Sep 24 2025
The short wave which has been bringing us rain is forecast to
continue digging southeast to the Gulf Coast through the end of the
week and close off over the southeastern U.S. this weekend.  The
pattern then becomes very blocky with a closed low over the
southwest U.S. and a ridge over the central U.S. between the two
lows.  Medium range GFS and ECMWF both show this blocky pattern
hanging in at least through next Tuesday, though they differ
somewhat on how the pattern evolves.  The LREF clusters are very
consistent with one another though, and all agree that the block
will stick with us through Tuesday.  This translates to dry weather
for the Mid Mississippi Valley under the influence of the upper
level ridge.  Should see plenty of sunshine each day with
temperatures warming to 5-10 degrees above normal in the mid 80s by
this weekend and continuing into next week.
Carney
&&
.AVIATION...  (For the 12z TAFs through 12z Thursday Morning)
Issued at 634 AM CDT Wed Sep 24 2025
Areas of MVFR and IFR ceilings generally along and south of I-70
are expected to slowly rise to VFR through the morning into early
afternoon. Another area of MVFR ceilings over southeast Iowa is
expected to drift into northeast Missouri and west central
Illinois before lifting after 15Z. Isolated showers this morning
will increase in coverage by early afternoon and will likely
include a few thunderstorms. Rain should end from northwest to
southeast this evening through 06Z. MVFR/IFR conditions will be
possible with the heaviest showers/storms. Prevailing ceilings may
drop back down to IFR heights across the eastern Ozarks overnight
tonight, and there is the possibility of fog before 12Z Thursday
morning, primarily across northeast Missouri and west central
Illinois.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX

NWS LSX Office Area Forecast Discussion