Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

700
FXUS63 KLSX 302006
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
306 PM CDT Mon Mar 30 2026

.KEY MESSAGES...

- Another day of record highs is possible on Tuesday with elevated
  fire weather expected for locations generally along and south of
  I- 36 in Missouri and Illinois.

- Several rounds of rain and thunderstorms are forecasted Tuesday
  night into Saturday night. Locations across central and northern
  Missouri have a 60-70% chance for >2" of rain Tuesday night into
  Thursday.


&&

.SHORT TERM...  (Through Late Tuesday Night)
Issued at 303 PM CDT Mon Mar 30 2026

Current mid-level water vapor imagery shows subtle ridging across
the center of the CONUS with an abundance of dry air in place across
the area that has allowed for a plethora of sunshine today. Surface
cyclogenesis on the lee side of the Rockies and a strong surface
high across the southeast CONUS has led to a tightened southwest to
northeast oriented pressure gradient across the Mid-Mississippi
River Valley today. The result has been strong southerly winds and
robust warm air advection that has aided in a quick warmup with
afternoon temperatures largely in the low/mid 80s across the bi-
state area. Elevated fire weather conditions were forecasted for
locations south of I-70 in Missouri this afternoon. Most the area
has trended a little higher with dew points than previously expected
which has resulted in slightly higher RH values. However, some
locations across the Ozarks will still reach elevated fire weather
conditions this afternoon.

A relatively stationary cold front that is currently positioned
across the Upper Midwest will have an influence on our sensible
weather for the remainder of the week. Tonight, a mid-level
shortwave traversing west-east along the US-Canadian border will
slowly push the cold front southward towards our area. Model
guidance is in good agreement that this front should enter
northeastern Missouri and west-central Illinois tomorrow evening,
keeping the entire area in the warm sector for another day with
widespread highs in the low/mid 80s nearing high temperature records
once again. However, about 30-40% of high-res guidance is keying in
on the development of a few showers and scattered thunderstorms
across north-central Missouri tomorrow morning along and just south
of the slow moving cold front. Any isolated thunderstorms tomorrow
should remain sub-severe since we lack any mid/upper-level forcing
that would support taller convective growth. The showers and storms
that develop will track eastward along the cold front with the bulk
of precipitation remaining to the north of I-70 generally across
northeastern Missouri and west-central Illinois on Tuesday.

With the slow southward propagating cold front forecasted to stay
north of the area on Tuesday, it will be another warm day with
southwesterly winds gusting to 25-30kts. The latest REFS joint
probabilities for Red Flag Warning criteria (RH <25%; sustained 10m-
wind >17mph) on Tuesday reach 20-30% across the Ozarks with a 70-80%
chance for elevated fire weather. Therefore, our current thinking is
that elevated fire conditions prevail with isolated spots briefly
reaching RFW criteria across the Ozarks tomorrow afternoon. For
locations along and north of I-70, confidence is much lower due to
the scattered showers/storms and more widespread cloud cover.
However, elevated fire conditions cannot be ruled out completely as
any location that remains dry or experiences abundant breaks in
cloud cover will dry out enough to reach elevated fire thresholds
since winds will be strong enough.

Peine/Kimble

&&

.LONG TERM...  (Wednesday through Next Monday)
Issued at 303 PM CDT Mon Mar 30 2026

At the start of the extended, the slow moving cold front will be
pushing southward through the area with model guidance still varying
on how far south the front makes it before stalling. The general
consensus within guidance parks the front somewhere near the I-70
corridor by Wednesday morning. As a result, a large spread in highs
can be expected on Wednesday with 50s to the north and 80s to the
south. This front will be the dividing line between abundant
rainfall with temperatures 10 degrees below average (north of the
front) to drier conditions with temperatures 20 degrees above
average (south of the front).

A mid-level trough is progged to eject into the Central Plains
Wednesday with the increased southerly flow ahead of the system
helping to lift the stationary front back to the north Wednesday
into Thursday. Over the last 24 hours, the position of this stalled
front has trended northward, which has led to a warmer trend in the
forecast for much of the area. This mid-level trough and its surface
reflection will lead to increased southerly flow, advecting an
abundance of moisture into the region with PWATs reaching 1.3-1.5",
which is near the 99th percentile for climatology. This will lead to
widespread rainfall Wednesday morning into Thursday night with the
axis of heaviest rainfall expected to stretch from Kansas City
northeastward into northern Missouri and west-central Illinois.
Within this corridor, the LREF and NBM mean is just over 2" with
amounts dropping off as you move southeast from this swath.
Regardless, the St. Louis metro has a 60% chance for >1" with
southern Missouri and Illinois at a modest 30-40%. The key take away
is that everyone will see rain with the Wednesday to Thursday night
round, but it will not be raining at any one location the entire
time.

A secondary mid-level trough ejects into the Plains Friday night
into Saturday bringing another widespread round of rain to the area
Saturday into Sunday. Currently, rainfall amounts appear to be
lighter but still substantial with this round of precipitation as
the NBM 72hr QPF probabilities for >1" are around 40-50% for most of
the area. It is worth noting that some of the higher end rainfall
potential could be washed out or muted this far out due to spatial
and temporal uncertainty within model guidance. Regardless, between
Wednesday and Sunday, multiple rounds of rain are forecasted with
the potential for nuisance flooding if the same areas receive the
heaviest rainfall with each round of precipitation. Behind the
second mid-level trough, northwesterly flow appears to hold on for a
few days which would knock back temperatures to near or slightly
below average along with drier conditions Sunday into early next
week.

Peine/Kimble

&&

.AVIATION...  (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1247 PM CDT Mon Mar 30 2026

VFR flight conditions are expected for the entire TAF period. Low-
level wind shear is expected at all terminals tonight as surface
winds relax and a 50kt LLJ develops overhead. Surface winds become
gusty tomorrow morning ending the LLWS threat by 14Z. Mid-level
clouds (VFR) will be on the increase as a slow moving cold front
approaches from the north approaching northeastern Missouri by
tomorrow afternoon/evening. Short-range guidance is keying in on
scattered showers and thunderstorms across central and northeastern
Missouri tomorrow morning into the afternoon. Any mention of this
has been left out for now since confidence in the coverage and
timing of any precipitation is low and temporally it is still about
20 hours away.

Peine/Pfahler

&&

.CLIMATE...
Issued at 238 AM CDT Sun Mar 29 2026

Record Maximum Temperatures at Regional Long-Term Climate Sites

             March 30th   March 31st

St. Louis:   86F (1986)   87F (1981)
Columbia:    84F (1967)   86F (1940)
Quincy:      82F (1943)   81F (2010)

Record High Minimum Temperatures at Regional Long-Term Climate Sites

St. Louis:   67F (1998)   63F (1917)
Columbia:    65F (1967)   59F (1967)
Quincy:      61F (1998)   58F (2010)


&&

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

$$

WFO LSX