Oakville, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

260
FXUS63 KLSX 281708
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1208 PM CDT Wed May 28 2025

.KEY MESSAGES...

- Showers will taper off and pull to the east by mid-morning. The
  next chance for showers and thunderstorms arrives late
  Wednesday into Thursday.

- Temperatures remain below normal through Friday. Much warmer air
  will push temperatures well into the 80s Saturday into next
  week.


&&

.SHORT TERM...  (Through Late Thursday Afternoon)
Issued at 300 AM CDT Wed May 28 2025

Scattered, light showers are pulling east of the Mississippi River
early this morning with observations showing most locations
measuring just a few hundredths of an inch. SPC mesoanalysis shows
MUCAPE is low enough (<250 J/kg) to be negligible, essentially near
zero. RAP guidance indicates pockets of around 100 J/kg or less
through the remainder of the morning and no lightning has been
observed in any of the activity over the last several hours.
Therefore, the slight chance (15-20%) for thunder was pulled from
the forecast for the remainder of the morning.

A high pressure ridge centered over the northern Great Lakes expands
westward today as it expands through the central Plains. The
southern periphery of the ridge is projected to gradually build into
the region today as low pressure departs to the east. Short range
guidance suggests a few showers could linger into the early
afternoon today. However, model soundings indicate capping develops
in the 700-750mb layer as air becomes less saturated on
northwesterly flow. A shallow, isolated shower is certainly
possible closely following this morning`s showers, but it will be
much harder to come by as time progresses. Measurable rainfall is
likely over once this morning`s activity moves out. Mid-level
saturation will keep clouds around through the early morning
before skies break late morning into early afternoon as saturation
erodes. This will allow temperatures to climb pretty close to
yesterday`s highs (low/mid- 70s).

The upper level low that has aided in steering shortwave after
shortwave through the region over the Memorial Day weekend into
early this week will finally begin to progress southeast through
Thursday. While vorticity continues to spoke around the parent low,
another shortwave independent from the upper low will drop southeast
into the Plains late this evening, then moves eastward through the
day Thursday. Guidance has shown some degree of a mid-level trough
extending westward from today`s exiting system, which separates
cooler H8 temperatures to the north and milder air to the south.
Upper ascent associated with the upper low rides over this mid-
level feature and results in a west-east oriented band of showers
over northern Missouri. Very little MUCAPE accompanies this
portion of the rainfall as it is further into the cooler air.
Meanwhile, the southern shortwave rides along a NW-SE oriented
CAPE gradient that will steer convective potential through Kansas
and Oklahoma this afternoon and evening.

As this system curves eastward around the upper trough, it begins to
pull the boundary southward as a cold front by late Thursday
afternoon and evening. The interaction of these features will result
in numerous showers and a few embedded thunderstorms. Thunderstorm
potential will likely be low (15-20%) over a majority of the CWA
considering that it is placed further into the cooler air with the
southward progression of the cold front. RAP/NAM/HRRR all show
MUCAPE largely confined to locations south of I-44 in Missouri and
pushing southeast through the late evening. Embedded thunderstorms
are more likely over Reynolds, Iron and Madison Counties (MO) with
perhaps a couple of rumbles of thunder as far north as I-70.


Maples

&&

.LONG TERM...  (Thursday Night through Tuesday)
Issued at 300 AM CDT Wed May 28 2025

We will finally see the last of the impacts of the upper level
low/trough late Thursday into early Friday morning. The surface low
tracks in the vicinity of the Missouri Bootheel into southern
Indiana, while the system slants to the northwest through the H8 and
H5 levels. A bulk of the precipitation moves east, while the
mid/upper portion of the low holds onto some lingering showers for
Illinois locations. The question then is how quickly skies clear.
High temperatures could be affected slightly, if clouds hold on over
the southern and eastern sections of the CWA. NBM has cooler
temperatures (mid-70s) for highs along and south of I-70 with upper
70s across northeastern Missouri and west-central Illinois.
Inversely, quicker clearing may lead to a slight adjustment in highs
where NBM currently holds temperatures back.

A return to warmth continues to be the main story for the upcoming
weekend into next week with high confidence in above normal
temperatures. Long range guidance has consistently shown an
amplified ridge building eastward from the western CONUS over the
last several forecast cycles. 500mb EOF cluster analysis shows only
minor disagreement in timing the eastward progression of the ridge
with height anomalies extending well north into Canada. NBM
interquartile ranges have been around 5-6 degrees with some
narrowing in the data. Sunday may have the biggest spread (~7
degrees), due to a shortwave that tracks down the southeast side of
the ridge late Saturday into Sunday and gives rise to convection
over the central sections of the U.S. However, NBM has begun to back
off PoPs (now below 15%), while deterministic guidance is leaning
slightly further west with upper the level shortwave. Temperatures
only continue to warm into next week as the ridge axis centers
overhead late Monday into Tuesday. NBM lower quartiles show highs in
the mid/upper 80s while the upper quartiles push temperatures into
the low-90s. This may end up being the first long duration heat of
this magnitude so far this year.

Chances for rain may return to the area late in the period, sometime
between Monday and Tuesday. The upper levels become busy with
shortwave traffic and one of these features becomes trapped and
meanders around for a couple of days over the central U.S. This
atypical behavior would suggest the predictability is low at this
distance in time and will likely change to some degree over the next
several days.


Maples

&&

.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1203 PM CDT Wed May 28 2025

Ceilings in stratocumulus have lifted over the past few hours,
with mainly low MVFR conditions expected this afternoon. Cannot
rule out a stray sprinkle or very light rain shower, but a vast
majority of the area should stay completely dry.

Widespread light rain is expected to enter parts of central
Missouri around daybreak Thursday and move eastward through most
of the area. Visibilities should drop to between 3-5SM, with
ceilings also dropping below 2000 feet AGL within a few hours
after the onset of the rain.

Gosselin

&&

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

$$

WFO LSX