Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 242031
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
331 PM CDT SUN APR 24 2016

.SHORT TERM...  (Through Late Tonight)
Issued at 330 PM CDT Sun Apr 24 2016

Most of the convection tonight is expected to remain north of our
forecast area, associated with an upper level low now over southwest
SD and a surface low over central SD which will move eastward
through the northern Plains.  Widely scattered, weakening convection
though may move into portions of northeast and central MO as well as
west central IL late tonight as a southwesterly low level jet brings
low level warm air advection and increasing moisture into this area.
Will just have slight chance pops late tonight for areas north and
west of STL.  Southerly surface/low level winds, increasing cloud
cover, and relatively high surface dew points will lead to low
temperatures 10 to 15 degrees above normal and warmer than the
previous night.

GKS

.LONG TERM...  (Monday through Next Sunday)
Issued at 330 PM CDT Sun Apr 24 2016

Warmer conditions to persist through Tuesday with several weak
shortwaves sliding through helping to trigger scattered showers and
thunderstorms. In the meantime, frontal boundary associated with
main system to slowly sink south, eventually stalling out along I-70
corridor by Tuesday afternoon.

More active weather to ramp up late Tuesday night as low level jet
increases with decent instability and convergence along the stalled
front. Elevated storms, some of which may be severe, could develop
into an MCS and slide east along front. Main threats would be large
hail, damaging winds and possibly a few tornadoes.

Depending on when morning activity diminishes/moves out on
Wednesday, another round of storms to develop as front moves back
north as a warm front and main cold front starts to slide through
Wednesday afternoon/evening. So if atmosphere is able to recharge,
storms to develop ahead of system with main threats being large hail
and damaging winds.

Precipitation to taper off Thursday and Thursday night, before next
chance of rain returns on Friday and persists through Sunday.
Otherwise, the default ridge setup in our part of the CONUS will
ensure that temps remain at or above average throughout the period.

Byrd
&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1113 AM CDT Sun Apr 24 2016

Just few-scattered diurnal cumulus clouds this afternoon, and
some high level clouds this evening. An upper level low now over
southwest SD and an associated surface low over central SD will
move eastward through the northern Plains tonight and into the
Great Lakes region on Monday. It appears that most of the
convection associated with this storm system will remain north of
the taf sites, although could not rule out a few showers or storms
late tonight and Monday morning impacting UIN and COU.  For now
will leave precipitation out of the tafs as the probability is
quite low and the timing still uncertain. Will get some low-mid
level clouds moving into the taf sites late tonight and Monday
morning as a low level jet brings increasing low level moisture
into the area. There may be a brief period of MVFR cigs Monday
morning in UIN or COU. Southerly surface winds, gusty at times
this afternoon and again late Monday morning, will become more
southwesterly Monday morning.

Specifics for KSTL: Few-sct diurnal cumulus clouds this afternoon,
high level clouds tonight, then VFR low-mid level cloudiness on
Monday. There may be a few showers/storms on Monday, mainly during
the afternoon, but will leave the STL taf dry for now as the
probability is quite low and the timing uncertain. Southerly
surface wind will increase to around 13-15 kts this afternoon and
become gusty. The southerly wind will weaken a little this
evening, then become more southwesterly Monday morning as well as
strengthen and become gusty again by late Monday morning.

GKS

&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     61  83  66  83 /  10  20  20  20
Quincy          60  80  61  79 /  20  20  20  20
Columbia        60  80  63  81 /  20  20  20  20
Jefferson City  60  82  64  82 /  20  20  20  20
Salem           59  80  65  81 /  10  20  20  20
Farmington      58  81  64  81 /  10  10  20  20

&&

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

$$
WFO LSX



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