Area Forecast Discussion
Issued by NWS St. Louis, MO

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FXUS63 KLSX 240856
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
356 AM CDT Wed May 24 2017

.SHORT TERM...  (Through Late Tonight)
Issued at 352 AM CDT Wed May 24 2017

Upper low continues to sink swd early this morning. As it does, the
pocket of mid clouds over central MO will continue to move esewd,
although, any precip associated with it will likely be
light/sprinkles.

Otherwise, expect much of the region to be dry thru about mid
morning as SHRA begin to develop. Expect these SHRA to continue to
develop thru the afternoon with isod TS also during the afternoon.
Uncertain exactly what coverage will be, but kept PoPs in high
chance range. These SHRA shud dissipate quickly with sunset, except
over the ern portions of the CWA where precip is more dynamically
forced.

As for temps, have trended twd cooler guidance for today expecting
most breaks in clouds to fill in. Also trended cooler for tonight as
well with the clouds breaking up as the ridge builds into the area.
Winds will be light tonight, especially across wrn portions of the
CWA. Have held off adding fog to the forecast with better conditions
west of the CWA. However, will need to monitor and may need to be
added with updates.

Tilly

.LONG TERM...  (Thursday through Tuesday)
Issued at 352 AM CDT Wed May 24 2017

Weak surface ridge will be over region on Thursday with dry and mild
weather in store for the forecast area. Highs will be in the low to
mid 70s.

By Thursday night, surface ridge to move off to the east as next
system moves in from the southern plains. Fairly zonal flow aloft,
frontal boundary associated with system to stall out along I-70
corridor for the last part of the work week and into the holiday
weekend. Will see increasing low level moisture towards daybreak on
Friday with showers and some storms on the increase. With sufficient
instability and shear could see an MCS develop and slide east along
boundary during this time period. However, timing and development
still hard to pin down. For the most part, will see several rounds
of showers and storms through Sunday, with best chances
Saturday/Saturday night.

By Sunday night, precipitation moves off to the south and east with
dry weather for Memorial Day. However, could see some wrap around
showers/isolated storms along and north of I-70 Monday afternoon and
evening. Could see more isolated/scattered showers on Tuesday, as
another spoke of energy aloft rotates around system anchored over
Great Lakes.

As for temperatures through the period, will see at or below normal
temps on Thursday, then warm up a bit above normal for the holiday
weekend despite the chances of precipitation. Then cool down to near
normal Sunday through Tuesday.

Byrd
&&

.AVIATION...  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1051 PM CDT Tue May 23 2017

Upper level low over IA will drop southeastward through eastern
MO on Wednesday. It appears that most of the showers will likely
be east-southeast of the taf sites late tonight into Wednesday
morning, although could not rule out isolated sprinkles from mid
level clouds. Scattered showers and a few storms should redevelop
over the area Wednesday afternoon. For now will likely just
include VCSH in the tafs Wednesday afternoon. Should have mainly
mid level cloudiness late tonight, then low level cloudiness will
develop Wednesday morning, possibly as low as around 2000-3000
feet. Northwesterly surface winds will continue through the period
with surface troffing across the OH and TN Valley regions and
surface ridging over the Plains.

SPECIFICS FOR KSTL: Upper level low over IA will drop southeastward
through eastern MO on Wednesday. It appears that most of the
showers will likely be east-southeast of the STL area late
tonight into Wednesday morning, although could not rule out
isolated sprinkles from mid level clouds. Scattered showers and a
few storms should redevelop over the area Wednesday afternoon. For
now will likely just include VCSH in the STL taf Wednesday
afternoon. Should have mainly mid level cloudiness late tonight,
then low level cloudiness will develop Wednesday morning, possibly
as low as around 2000-3000 feet. Northwesterly surface winds will
continue through the period with surface troffing across the OH
and TN Valley regions and surface ridging over the Plains.

GKS
&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     65  52  74  59 /  40  20   0  10
Quincy          62  50  72  57 /  30  20   0  20
Columbia        62  49  74  59 /  30   5   0  20
Jefferson City  64  49  75  59 /  30  10   0  20
Salem           65  53  73  56 /  40  20   5  10
Farmington      63  49  74  57 /  40  20   0  10

&&

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

$$
WFO LSX



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