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FXUS63 KLSX 020315
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1015 PM CDT Fri Aug 1 2025

.KEY MESSAGES...

- Pleasant and dry summer weather continues through the weekend.

- A gradual warm up is expected next week, with an eventual return
  to the 90s.


&&

.SHORT TERM...  (Through Late Saturday Afternoon)
Issued at 150 PM CDT Fri Aug 1 2025

Our stretch of pleasant summer weather is fully here. Dewpoints have
fallen into the 50s in many spots with temperatures only reaching
the 70s to low 80s. Surface high pressure over the Upper Midwest has
brought us this pleasant break from summer`s heat. This surface high
gradually weakens and expands eastward into the Great Lakes this
weekend with its influence still felt across our area. A dry
northeast flow maintains these pleasant dewpoints and cool
temperatures. Nighttime lows drop into the 50s for most. There
remains some wildfire smoke caught up in the mid level northwesterly
flow, subsiding into the surface high. However, this is not expected
to be particularly noticeable for most of us. The surface high
weakening with time and northwesterly mid level flow shifting to
more westerly should limit the quantity of smoke infiltrating
our region.

Kimble

&&

.LONG TERM...  (Saturday Night through Next Friday)
Issued at 150 PM CDT Fri Aug 1 2025

Ridging gradually builds over the Southwest US next week, eventually
expanding to bring some warmer temperatures back into our region.
With this ridge nudging in from the west, and prolonged low level
northerly to easterly flow ahead of it, we won`t have as much Gulf
moisture to bring the more extreme humidity back. So even though our
temperatures begin to climb back into the 90s by the end of next
week, our humidity is not expected to be as oppressive. There`s also
pretty strong agreement that ridging will be beat back by a deeper
trough next weekend, so the return of heat won`t be as long lasting
as our last heat wave.

Rain chances also remain fairly minimal through the weekend into the
coming week. The only potential source of rain is a shortwave trough
which slowly rounds the northeast side of the ridge and gets cut off
over the lower Mississippi Valley Monday into Tuesday. Forcing
within this trough will be fairly weak and instability pretty
limited due to the lack of robust moisture return, so widespread
rain is not likely. However, a few pop up showers or thunderstorms
could occur in the vicinity of this trough mainly Monday into
Tuesday. This is most likely in our eastern forecast area where some
marginally better low level moisture arrives from the east just as
the trough settles in aloft. Rain chances the rest of the week are
more related to waves rounding the top of the western ridge and
confidence in whether one or more of those reaches our area and when
is low enough to limit NBM PoPs to 20 percent or less each day.

Kimble

&&

.AVIATION...  (For the 06z TAFs through 06z Saturday Night)
Issued at 1012 PM CDT Fri Aug 1 2025

Haze/wildfire smoke will reduce visibilities to low VFR/possible
MVFR through 15Z, mainly at UIN and SUS. Other dry and VFR
conditions are expected through the period. Winds will continue
mainly out of the east to northeast through the period.

Britt

&&

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

$$

WFO LSX