Rocheport, Missouri Weather Forecast Discussion

774
FXUS63 KLSX 011108
AFDLSX
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
608 AM CDT Wed Oct 1 2025
.KEY MESSAGES...
- Warm and dry weather is favored through Monday.
&&
.SHORT TERM...  (Through Late Thursday Afternoon)
Issued at 317 AM CDT Wed Oct 1 2025
The commanding ridge that has dominated the pattern over the last
several days will shift eastward through the period. As this occurs,
a weak upper level shortwave trough approaches the Mississippi
Valley over the next 24 hours. The trough is insignificant in terms
of sensible conditions, but will continue to send scattered to
broken high clouds overhead, in addition to a few diurnal mid-
level clouds this afternoon. The end result will be partially
obscured sunshine and high temperatures (mid to upper 80s) a few
degrees cooler than Tuesday. Clouds clear out late tonight into
early Thursday with lows in the upper 50s to low-60s.
Though ridging shifts to the east, it will maintain its grip with
warm and dry conditions becoming baked into the forecast. Mostly
sunny conditions are expected Thursday, bumping high temperatures
back into the upper 80s to near 90 degrees.
Maples
&&
.LONG TERM...  (Thursday Night through Tuesday)
Issued at 317 AM CDT Wed Oct 1 2025
One small change since the last update is the subtle hint at a stray
shower or two Thursday evening into Friday. Upper level ridging
amplifies out of the southwest, drawing a weak upper level vort lobe
southward and parallel with the Mississippi River. The mid-level
ridge that is centered over the Ohio Valley advects moisture
north-northwestward into southern Missouri and Illinois by
Thursday evening. GFS/GFS MOS is most bullish with precipitation
chances (~30% 24-hour prob.) ending 00z Saturday (Friday evening).
It is less evident in the tail end of hi-res guidance, but
HRRR/RAP does show a stray shower or two. The signal is a little
better Friday afternoon as diurnal trends take over, potentially
sparking a few diurnally driven showers. Ensemble guidance places
spotty potential across the area with probabilities for measurable
precipitation ranging 20-40%. Even if something panned out, the
weak signals that are there now would not result in any widespread
relief. Despite a dry forecast, if this trend bears any truth, a
couple of places could get lucky with a localized brief shower.
Dry weather and above normal warmth continue through the weekend.
Highs continue to climb well into the 80s with a few locations
touching 90 degrees, mainly in and around urban areas. Dry weather
is favored Monday. However, there is some indication that low
precipitation chances could arrive as soon as Monday afternoon.
As upper level ridging centers over the mid-Atlantic Region,
southerly flow around the western side of the mid-level ridge
overruns the slow-moving surface cold front from the north. It
has becoming increasingly evident that the blocking pattern will
temporarily stall the front at least until late Tuesday, when a
strong surface ridge builds into the Upper Mississippi Valley and
shunts the front southward through Wednesday morning.
There is a little better agreement with long range deterministic
guidance with general consensus of the overall pattern. Peak
precipitation potential and temperature trends will be dependent
on the progress of the front. Latest LREF guidance has bumped up
to 30-35% for measurable precipitation. NBM guidance maintains a
dry forecast Monday, but trends could prove otherwise. Mean
precipitation totals of around 0.25" fall from late Monday
afternoon through Wednesday with the 75th percentile indicating
less than 0.50". Unfortunately, it still doesn`t look all that
promising in terms of widespread beneficial rain.
There is an interesting note about the recent heat and what is
expected over the next week. While the heat has been notable, we`ve
not hit any record highs as we`ve been competing with triple digit
records from the 1950s. While missing a record isn`t something to
write home about, the mean temperatures tell a different story.
Climatological means for October 1 through October 5 show that
this year`s warm start to October could end up ranking in the top
5 warmest starts, if not flirting with the top 3.
Maples
&&
.AVIATION...  (For the 12z TAFs through 12z Thursday Morning)
Issued at 606 AM CDT Wed Oct 1 2025
Scattered to broken high clouds will continue streaming overhead
today with light and variable surface winds intermittently
reaching above 5 knots. VFR conditions are expected throughout the
period.
Maples
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX

NWS LSX Office Area Forecast Discussion