Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 051133

633 AM CDT MON OCT 5 2015

.SHORT TERM:  (Through Late This Afternoon)
Issued at 317 AM CDT Mon Oct 5 2015

Look for decreasing low clouds this morning but a gradual increase
in mid/high clouds by afternoon. The lack of extensive stratus
should lead to warmer afternoon high temperatures across the region
today compared to yesterday. Winds will remain out of the north or
northeast due to the influence of a ridge axis to the north.


.LONG TERM:  (Tonight through Sunday)
Issued at 317 AM CDT Mon Oct 5 2015

Still appears tranquil weather will persist for the CWA heading
into midweek as weak ridging holds over the central CONUS. The
primary forecast question through Wednesday is temperature
specifics. AMS will be quite mild for early October with 850MB
temps roughly between +10 to +13C, but models are indicating
several waves of cloudiness...first from moisture streaming north
from Mexico, then with additional moisture advecting east from
the Plains.

Not certain as to the exact extent of this cloudiness, but models do
seem to agree that it will not be the insolation-killing low
cloudiness that made for a very chilly Sunday afternoon along and
west of the Mississippi River, but rather cloudiness of the mid
and high level variety. Given the extent of cloudiness suggested
by forecast soundings for Tuesday I`ve trimmed back temps a bit to
reflect roughly a 15-20 degree warmup from early morning
lows...which puts them in line with conditional climatology values
with a mid cloud deck for early October. Clouds should be less
extensive on Wednesday, and this should allow highs to push into
the 75-80 degree range.

After nearly a week of stalled weather features over the eastern two-
thirds of the CONUS, the GFS, ECMWF, and GEM all remain in fairly
good agreement that the upper air pattern will become much more
progressive during the latter half of the week.

A strong shortwave in the westerlies will dip southeast and push
through the mid and upper Mississippi Valley on Thursday and
Thursday night, bringing a threat of showers and thunderstorms to
the entire forecast area.  However, by Friday the GFS has the
shortwave trof east of the area, while the ECMWF and GEM slow the
movement of this feature over the mid-Mississippi Valley.  Based on
this, will maintain some PoPs over at least the southeast half of
the CWA on Friday.  Temperatures will remain very mild on Thursday,
with a noticeable cool down in the wake of the front on Friday.

Ridging is then expected to build back into the central U.S. over
the weekend as shortwave continues to dig into the eastern part of
the country.  Temps over our area should rebound in response,
with highs well in the 70s once again by Sunday.



.AVIATION:  (For the 12z TAFs through 12z Tuesday Morning)
Issued at 629 AM CDT Mon Oct 5 2015

Overnight MVFR stratus has largely moved off to the west and
northwest, although a few sites around the region were reporting
fog and/or new IFR stratus development early this morning. Current
thinking is that any of the newly developed early morning
fog/stratus should be short-lived given the arrival of mid/high
clouds and imminent sunrise. Any cig/vis restrictions should be
temporary and return to VFR by 15-16z. VFR conditions are then
expected for the rest of the TAF period.





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