740 
FXUS63 KLSX 190916
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
416 AM CDT Tue Oct 19 2021

.SHORT TERM... (Through Wednesday Night)
Issued at 316 AM CDT Tue Oct 19 2021

An upper level ridge extended from WI south-southwest through AR 
with an upper level low over UT early this morning. A surface 
ridge was centered over the TN Valley region. Above normal high 
temperatures, similar to yesterday can be expected today with 
upper level ridging over the region and southerly surface winds. 
The only noticeable difference will be some high level cloudiness 
along with stronger winds today. The chance of showers and a few 
storms will return to our area Wednesday and Wednesday evening as 
the upper level low moves eastward through the Northern Plains and
into the Great Lakes region and sends a cold front southeastward 
through our forecast area Wednesday afternoon and night. Scattered
showers and a few storms can be expected along and just ahead of 
the cold front. With only modest low level moisture and instability
along with relatively weak convergence along the front, rainfall 
amounts in general will be on the light side and severe storms 
are not expected, although a few storms could still produce a 
brief heavy downpour, small hail, and strong gusty winds. Cooler 
low temperatures can be expected Wednesday night across northeast
and central MO and west central IL with cold air advection behind
the front.

GKS

.LONG TERM... (Thursday through Monday)
Issued at 316 AM CDT Tue Oct 19 2021

It will be cooler Thursday and Friday, especially across 
northeast MO and west central IL due to northwesterly upper level 
flow, and as a surface ridge over the Northern Plains builds 
southward into MO. Although low level moisture will be limited, 
northwest flow shortwaves could bring a few sprinkles. A much 
better chance of more significant rain can be expected Saturday 
night through Sunday night as the surface ridge shifts east-
northeast of the region and a warm front lifts slowly north-
northeastward through our forecast area. Above normal temperatures
will return on Monday as an upper level ridge builds over the 
central US, and winds become south-southwesterly as the warm front
shifts north- northeast of the forecast area.

GKS

&&

.AVIATION...  (For the 06z TAFs through 06z Tuesday Night)
Issued at 1144 PM CDT Mon Oct 18 2021

VFR conditions are expected to extend through the entire period. 
The only item to note is the potential for gusty southerly winds 
through the daylight hours Tuesday. 

A cold front will approach from the northwest late Tuesday night,
but active weather should remain outside all terminals.

GKS

&&

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

$$

WFO LSX