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Area forecast discussion...updated aviation 
National Weather Service St Louis MO
645 am CDT Fri Oct 24 2014

Short term: (through late this afternoon)
issued at 335 am CDT Fri Oct 24 2014

Weak shortwave will round periphery of mid/upper ridge with main impact
being an increase in high-level cloudiness for portions of the area.
At the sfc...a weak frontal boundary will approach northwestern sections
of the County warning forecast area by 0000 UTC Saturday. At this wet weather is
expected to accompany this frontal boundary. Temperatures will continue
on the upswing with highs back above average ranging from the upper
60s over south-central Illinois to low/mid 70s for portions of central...
east-central...and southeastern Missouri.


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 County Warning Area 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 12z tafs through 12z Saturday morning)
issued at 631 am CDT Fri Oct 24 2014

Fog will be slow to burn off this morning, but shud gradually lift
to become St before breaking up. Timing is still somewhat
questionable, but will update as needed. VFR conditions are then
expected thru much of the evening. An approaching cdfnt will shift
the winds to the NW, but will remain light. Fog is expected once
again tonight. Timing and locations are still uncertain, but
confidence is high enuf to lower vsbys into low MVFR range.

Specifics for kstl: mainly VFR conditions are expected thru the
day. However, patches of MVFR cigs may briefly impact the terminal
this morning. Otherwise, winds are expected to remain light with
fog possible around sunrise Sat morning. Have not mentioned in taf
attm due to uncertainty.



Lsx watches/warnings/advisories:
MO...dense fog advisory until 9 am CDT this morning for Audrain MO-
Boone MO-Callaway MO-Knox MO-Lewis MO-Marion MO-Monroe MO-
Ralls MO-Shelby MO.

Illinois...dense fog advisory until 9 am CDT this morning for Adams Illinois.



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