Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 242033

333 PM CDT Fri Oct 24 2014

.SHORT TERM:  (Tonight through Sunday)
Issued at 332 PM CDT Fri Oct 24 2014

The last vestiges of this morning`s low clouds and fog is finally
dissipating.  However, clearing sky and light wind combined with
relatively high dewpoints in the mid and upper 50s tonight will
likely produce more fog.  A weak trof of low pressure now moving
through eastern Nebraska will also drop into the area providing a
little lift and convergence but not much of an increase in wind.
Unsure how low to go at this time, but at least patchy fog looks
likely with more widespread fog in northeast MO/west central IL.

Fog will likely linger into the daytime hours of Saturday morning.
A lot of uncertainty as to how long...but at least through 14-15Z
seems likely.  The trof is expected to come to a halt Saturday
afternoon/evening near the MO/AR border then begin lifting back to
the north as a warm front as warm advection begins ahead of the next
system.  The warm front continues lifting north Sunday and decent
mixing should give us temperatures well above normal.  MOS
temperatures through Sunday look pretty reasonable so have followed
them closely.


.LONG TERM:  (Tonight through Thursday)
Issued at 335 AM CDT Fri Oct 24 2014

(Tonight - Monday)

Aforementioned frontal boundary is progged to move through the rest of
the CWA overnight tonight with little fanfare other than a subtle wind
shift from the southwest to the west/northwest. With light winds and
clearing skies behind boundary and associated shortwave trough...did
lean a bit toward cooler NWP guidance with lows mainly in the 50s across
the area.

The Saturday through Monday period will be characterized by well-above
normal temperatures as upper-level ridging builds overhead and 850-hPa
thermal ridge advects toward the mid-Mississippi Valley. Have upped highs
quite a bit from previous forecast into the 70s/80s areawide or some
10-20 degrees above normal. Lows will also follow suit and get progressively
warmer. All in all...dry and unseasonably warm will be the rule with
record or near-record high and/or high low temperatures possible.

(Monday Night - Thursday)

A cold front will move through the area on Monday night with medium-ranged
guidance in very good agreement with fropa timing and associated rain
chances. This front should bring a fairly good chance of showers with
thunder also possible. Instability looks almost non-existent however due
to low-leevl ridging preventing Gulf moisture from streaming northward.
However...did leave mention of thunder in the grids as believe there
should be at least some meager instability...if nothing else due to the
very anomalous sfc temps. This front will also finally move out the
unseasonably warm temperatures and usher in daytime highs and nighttime
lows much closer to seasonal norms for late October. Highs are expected
to be back in the 60s with lows in the 40s Tuesday through Thursday along
with dry weather conditions.



.AVIATION:  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1203 PM CDT Fri Oct 24 2014

Stratus and fog were slow to clear this morning, a true sign of
the changing of the season and lower sun angle. Should see most if
not all locations become VFR this afternoon before a renewed
threat of fog or stratus development tonight ahead of a weak trof.

Specifics for KSTL:

VFR conditions expected to continue with a light south wind
becoming west/northwest tomorrow morning. There is a chance of
some MVFR fog developing late tonight and early tomorrow morning.



Saint Louis     59  78  55  79 /   0   0   0   5
Quincy          54  75  50  77 /   0   0   0  10
Columbia        56  79  55  83 /   0   0   0   5
Jefferson City  55  79  53  83 /   0   0   0   5
Salem           54  75  49  76 /   0   0   0   5
Farmington      55  77  51  80 /   0   0   0   0




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