Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 180238

Area Forecast Discussion...Updated
National Weather Service Saint Louis MO
938 PM CDT MON OCT 17 2016

Issued at 937 PM CDT Mon Oct 17 2016

Warm and breezy evening is ongoing as area lies in tight pressure
gradient between low pressure over the upper Midwest and high
pressure off the southeast coast. Still expect tonight will be
mainly dry with a relatively dry atmosphere and not much forcing.
With the winds staying up tonight and scattered-broken cirrus
overhead, going lows in the mid 60s to around 70 still look good.



.SHORT TERM...  (Through Late Tonight)
Issued at 349 PM CDT Mon Oct 17 2016

Wind gusts of 30-40 mph were ongoing this afternoon across the
CWA. Although the intensity of the wind gusts will diminish after
sunset, some gusts will still persist through the night. A cold
front will move into the region overnight. Overnight lows are
expected to be around 25 degrees above average except for the
extreme northwestern corner of the CWA where the cold front will
have made sufficient progress to affect overnight lows.


.LONG TERM...  (Tuesday through Next Monday)
Issued at 349 PM CDT Mon Oct 17 2016

Main changes from the prev forecast deal with Tues and Wed.

Have added PoPs for Tues as the cdfnt approaches the region. The LLJ
Tues morning will help push moisture into the region. With the cap
eroding, or even non-existent, just ahead of the fnt, believe there
will be a threat for some precip across parts of the CWA.

Mdls continue to differ regarding where the sfc fnt and 850mb fnt
will be located Tues night into Wed. This presents different
possibilities as to where the precip will set up. Therefore, have
continued some more widespread PoPs across the region, with the
highest PoPs for those areas and times that mdls are in agreement.

The GFS is slower with the upper trof late this week which poses
some uncertainty for temps this weekend. Regardless, with continued
CAA on Sat, temps shud be a little below seasonal avg. Temps shud
begin to rebound early next week.

With the sfc ridge axis stretched across the Gulf, the extd
portions of the forecast are expected to remain dry.



.AVIATION...  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 617 PM CDT Mon Oct 17 2016

A strong low level jet between 1000-2000ft AGL over the area will
cause LLWS at the terminals tonight. This will occur even with
gusty south winds tonight. The gusts will diminish tomorrow with
the approach of a cold front and winds will veer out of the
northwest behind it. While there may be some isolated showers
along the front that could affect the St. Louis area terminals on
Tuesday afternoon, confidence is too to include any mention of
rain at this time. Will go with just dry and VFR conditions at all
of the terminals for now.

SPECIFICS FOR KSTL: A strong low level jet around 1500ft AGL will
cause LLWS at the terminal tonight. This is despite the fact there
will be gusty south winds through the night tonight. The gusts
will diminish tomorrow as a cold front approaches the terminal
from the northwest and moves through early tomorrow evening. Some
isolated showers could affect the terminal tomorrow afternoon,
though confidence is too low to include any mention of rain at
this time. Will go with just dry and VFR conditions at the
terminal for now.



Issued at 245 AM CDT Mon Oct 17 2016

Unseasonably warm conditions are expected to persist through
Tuesday and may approach record territory. The following lists
record high temperatures and record high minimum temperatures for
St. Louis, Columbia and Quincy during these times.

St. LouisColumbiaQuincy

10/17High Low:66/199864/196566/1935

Tuesday High:87/195386/195387/1924
10/18High Low:68/198564/197166/1938




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