Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

297
FXUS63 KLSX 071129
AFDLSX

Area Forecast Discussion
National Weather Service St Louis MO
529 AM CST Sat Nov 7 2026

.KEY MESSAGES...

- A Freeze Warning remains in effect through 8 a.m. this morning.

- Hazardous weather is not anticipated through next Saturday as
  dry conditions prevail and temperatures gradually warm to
  start the week.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 332 AM CST Sat Nov 7 2026

Temperatures are expected to fall near and below freezing areawide
this morning - A Freeze Warning continues through 8 a.m. After a
seasonably cool Saturday, milder temperatures arrive Sunday with dry
conditions persisting.

Surface analysis shows high pressure centered over eastern Kansas
and western Missouri early this morning with well-defined clearing
in the stratus deck extending through central/southeast Missouri in
the latest GOES-19 microphysics satellite imagery. Raw metar plots
indicate dewpoints range from the upper 20s to mid-30s, matching the
lower quartile from the 00z REFS. RAP/HRRR guidance is often more
aggressive in picking out lower dewpoint values and drying trends,
suggesting dewpoints fall another 2-3 degrees, favoring the lower
quartile of the REFS guidance. Forecast lows in the upper 20s to low-
30s are on track with locally cooler readings in outlying areas,
especially north of I-70.

What has also become well-defined is the development of river steam
fog north of the Mississippi River confluence. Latest USGS data
reflects Mississippi River temperatures in the mid-50s near Quincy,
IL to the low-60s near Cape Girardeau. As air continues to cool
tonight, additional river steam fog is likely to develop at other
locations paralleling main rivers/tributaries. Early morning
commuters should remain cautious when approaching bridges, where
rapid visibility restrictions are likely.

Today`s temperatures won`t be far off the mark from yesterday`s with
highs ranging through the 50s. High pressure remains in control
tonight, though the coolest air shifts south of I-70 as westerly
flow increases around the northern side of the ridge and high clouds
accompany the southeast progression of an upper level trough. The
late night/early morning time of high clouds over the northwestern
portion of the CWA could be enough to inhibit lows from making it to
freezing, while upper 20s and low-30s are spread across southeast
Missouri and southwest Illinois Sunday morning. Mid-level thermal
profiles indicates 850mb air warms to around 10C, an increase of
approximately 3-5C. This brings temperatures near normal for Sunday
afternoon with highest in the low to mid-60s under mostly clear
skies.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 332 AM CST Sat Nov 7 2026

Milder conditions are expected with near to above normal
temperatures through Wednesday. Seasonably cool temperatures return
late in the week with dry weather favored through much of the period.

(Monday through Wednesday)

The northern stream remains active and departed to the north with
several upper level disturbances traversing the northern CONUS and
southern Canadian Provinces. Meanwhile, a broad, closed low evolves
into and open wave as it slowly crosses Texas moves eastward into
the Gulf States. The axis to a low amplitude mid-level ridge
approaches the Mississippi Valley Monday, being closely followed by
a mid-level trough. Both features progressively become more muted
through Wednesday as mid-level temperatures in the mid-teens (C)
over the northern Plains are moderated before reaching the
Mississippi Valley thanks to northwesterly flow aloft. The only hint
at rain comes late Wednesday as a weak surface low develops near the
Missouri/Arkansas border and quickly moves eastward. The system is
not well organized at this stage, lacking both moisture and broad
support for beneficial rainfall. Highs are expected to be in the 60s
each afternoon. Chilly morning lows in the 30s/40s Monday give way
to the 40s Tuesday and Wednesday morning.

(Thursday through Saturday)

Both GFS/ECM global guidance show a long wave trough enveloping the
eastern CONUS through the later portion of the period, though its
development and exact evolution give rise to increasing spread
through the later portion of the period. Despite the disagreement,
the general characteristics are becoming more clear, including
seasonably cool or chilly temperature late in the week into next
weekend. LREF ensembles show the greatest spread in the upper level
pressure pattern extending from the Dakotas through Oklahoma,
indicating uncertainty in the depth or breadth of its influence.
ECMWF/GFS Ensembles do agree, in characteristic, that cooler
conditions arrive by Thursday with the coolest air arriving Friday.
Spread decrease briefly when surrounding the cooler air before
expanding once again Saturday, suggesting timing differences in the
eastward progression of the longwave trough. Several embedded
shortwaves rotate down the western side of the trough, though the
number, placement, and timing of these features are not well handled
at this distance in time, though low end precipitation potential
may become more evident as we progress through the week.

&&

.AVIATION /12Z TAFS THROUGH 18Z SUNDAY/...
Issued at 525 AM CST Sat Nov 7 2026

Clear skies and calm wind have allowed temperatures to cool well
in the 30s this morning, which has resulted in the river steam
fog that is impacting terminals adjacent to rivers and river
valleys. The densest has been observed around KJEF and KSUS with
restrictions occasionally down to 1/4SM. River steam fog will
erode around or just after 13z.

Otherwise, conditions quickly return to VFR this morning as sct/bkn
high clouds stream in from the west today.

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...Freeze Warning until 8 AM CST this morning for MOZ018-019-026-
     027-034>036-041-042-047>052-059>065-072>075-084-085-099.
IL...Freeze Warning until 8 AM CST this morning for ILZ058>060-064-
     065-069-070-074-079-095>102.

&&

$$

SHORT TERM...Maples
LONG TERM...Maples
AVIATION...Maples