Sapp, Missouri Weather Forecast Discussion

642
FXUS63 KLSX 290702
AFDLSX
Area Forecast Discussion
National Weather Service Saint Louis MO
202 AM CDT Mon Sep 29 2025
.KEY MESSAGES...
- Fall warmth continues this week with no significant rain chances
  in sight.
&&
.SHORT TERM...  (Through Late Tuesday Afternoon)
Issued at 201 AM CDT Mon Sep 29 2025
An upper level ridge remains centered over the mid Mississippi River
area today. A broad surface high is centered over the eastern Great
Lakes but its influence extends through our area and all the way to
Texas. The result for us is warm temperatures and continued dry
conditions. The next couple of days are likely the warmest of the
week as the ridge aloft is at peak intensity. Still, though,
nighttime temperatures drop back to around 60 or the upper 50s due
to strong nighttime cooling conditions and a dry air mass.
Kimble
&&
.LONG TERM...  (Tuesday Night through Sunday)
Issued at 201 AM CDT Mon Sep 29 2025
Expansive surface high pressure over the northeast US maintains an
easterly flow over the Deep South, keeping rich Gulf moisture
suppressed well to the south over Mexico and far south Texas this
week. Our air mass locally doesn`t change much in a stagnant flow
regime with dewpoints remaining mostly in the 50s to low 60s at
times. We`ll continue to see the warm days and seasonably cooler
nights with no rain in sight. The upper ridge does eventually tilt
and break down a bit by this weekend, with a western US trough
pushing eastward into the Plains. But at the moment, it doesn`t look
to get close enough to our area to produce meaningful rain chances
through this weekend. Surface high pressure does move to the East
Coast, though, with a southerly flow over the center of the country
opening us up to increased moist advection from the Gulf late this
weekend into early next week. So our chances of developing
instability or taking advantage of one of the passing troughs
slamming into the ridge to squeeze out a little rain will start to
increase. But even the long range guidance is pretty clear that the
better chances stay to our north and west even early next week as
the ridge stays more dominant over our area. For now the dry
forecast will continue.
Kimble
&&
.AVIATION...  (For the 06z TAFs through 06z Monday Night)
Issued at 1036 PM CDT Sun Sep 28 2025
Made no changes to going TAFs as I expect additional fog to
redevelop again tonight in the river valleys including at
JEF/SUS/CPS with similar visibilities and ceilings as what we had
early on Sunday morning. Other than that, expect dry and VFR
conditions with mainly light winds.
Britt
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX

NWS LSX Office Area Forecast Discussion