Old Jamestown, Missouri 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

372
FXUS63 KLSX 081717
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1217 PM CDT Thu May 8 2025

.KEY MESSAGES...

- Showers and scattered thunderstorms are expected to continue through
  early this evening, with the best chances (50-70%) along and
  south of I-70.

- Dry weather is expected Friday through Sunday along with near to
  slightly below normal temperatures.

- Rain chances (20-50%) return early next week, with a focus during
  the afternoon hours on Monday and Tuesday.


&&

.SHORT TERM...  (Through Late Friday Afternoon)
Issued at 320 AM CDT Thu May 8 2025

Scattered to numerous shower activity along with a few rumbles of
thunder have continued tonight, with a focus in a west-east band near
the I-70 corridor in Missouri. This is where low-level moisture
convergence is strongest just north of the track of the weakening
850-hPa cyclone. This low is expected to continue to weaken today,
with its remnant trough axis sliding southward toward the mid south
by early this evening. This in turn means a shift to the south with
the highest PoPs (50-70%) in southeast Missouri and southwest
Illinois this afternoon. Further north, scattered showers will
linger into the early evening as a backdoor cold front moves from
north to south. After this front passes through the CWA, rain
chances cease as cooler and drier air filters into the region.

Decreasing clouds are forecast overnight with light northeasterly
surface winds. Temperatures will cool, especially across northeast
Missouri and west-central Illinois where it clears first. Lows in
the low to mid 40s are forecast in these areas, with upper 40s to
low 50s further south. These readings would be about 5 degrees below
normal for the date.

A seasonably cool day is on tap for Friday with light northeasterly
winds and a sunny sky. Highs are forecast to range from the upper
60s to low 70s.


Gosselin

&&

.LONG TERM...  (Friday Night through Wednesday)
Issued at 320 AM CDT Thu May 8 2025

(Friday Night - Sunday)

Dry and near to below normal temperatures are forecast through the
weekend as a ridge of surface high pressure remains quasi-anchored
across the Mississippi Valley. Highs in the 70s are forecast both
Saturday and Sunday, with Sunday the warmer of the two afternoons.
Low temperatures both mornings are expected to be in the mid 40s to
low 50s.


(Sunday Night - Wednesday)

Ensemble guidance remains in good agreement with the evolution of
the cutoff midlevel low over the lower Mississippi Valley heading
into early next week. The consensus remains for it to shift back
northward toward the lower Ohio Valley early next week before it
kicks out to the north and east. The timing has slowed down slightly
(~6-12 hours) compared to this time yesterday however. This delays
the onset of PoPs a bit, but the general theme is the same. Look for
an increase in cloud cover starting Sunday night, with PoPs focused
mainly during the afternoon hours on Monday and Tuesday when
instability is maximized. The highest PoPs (30-50%) remain across
east-central and southeast Missouri as well as southern Illinois
closer to the track of the closed midlevel low. By Wednesday, the
low should be far enough northeast that dry weather is favored
with mid/upper level ridging building into the mid-Mississippi
Valley. After a period of near to slightly above normal
temperatures, a sizable warmup will begin on Wednesday. Mainly mid
80s are forecast by Wednesday afternoon, or some 10+ degrees
above normal. There is high confidence in these well-above normal
temperatures given the synoptic pattern, and this is also
supported by a low inter-quartile range on the NBM (~3-5F). Even
the 25th percentile of the NBM shows highs at least several
degrees above normal.


Gosselin

&&

.AVIATION...  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1209 PM CDT Thu May 8 2025

This morning`s precipitation has ended across the central Missouri
terminals and is edging eastward out of the St. Louis metro
terminals. At those sites, on/off showers are possible through
19-20Z with KCPS most likely to see precipitation. Thunder
chances are too low to mention, but I cannot rule out a stray
lightning bolt at some point in the early afternoon. KCPS is also
most likely to see MVFR ceilings, associated with this rain,
through mid afternoon. Once the rain moves out, ceilings are
expected to lift to VFR conditions.

Otherwise, VFR flight conditions will dominate the TAF period and
the sky will clear this afternoon into the evening.

Delia

&&

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

$$

WFO LSX