Area Forecast Discussion
Issued by NWS St. Louis, MO

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711
FXUS63 KLSX 162117
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
317 PM CST Fri Feb 16 2018

.SHORT TERM...  (Through Late Saturday Afternoon)
Issued at 315 PM CST Fri Feb 16 2018

Surface ridge to continue building into region early tonight. So
will see winds diminish this evening. With the lighter winds and
clearing skies, temperatures to drop into the low 20s to low 30s.
However, will begin to see mid and high clouds move back into region
from the southwest as next system approaches area. The cloud cover
will keep temps steady and maybe even rise a bit towards daybreak
for portions of central and southern MO.

Also, low level moisture will be on the increase, but a lot of dry
air to overcome, so precipitation chances to very slowly ramp up
from southwest to northeast through Saturday morning with this
system. Some concern about precip type initially because of the
colder air and evaporative cooler aloft. So will see it begin as
light snow, then become mixed with rain, then all rain by midday
Saturday. Portions of central and southern Missouri could see a
few tenths of an inch of snow, especially over the Ozarks.
However, the ground will be a bit warmer so most of it will melt
on contact.

The rain will taper off by the late afternoon hours as system exits
region. Despite the cloud cover and precipitation, temps to warm up
into the low 40s to low 50s on Saturday.

Byrd

.LONG TERM...  (Saturday Night through Next Friday)
Issued at 315 PM CST Fri Feb 16 2018

Active weather pattern to persist through rest of forecast period.

Will have a bit of a break Saturday night through Sunday with
temperatures moderating. Highs by Sunday will be in the mid 50s to
low 60s.

Warm southerly flow to persist Sunday night through Monday as a more
significant cold front approaches region from the northwest. Will
see several rounds of rain from Sunday night through Wednesday
evening. With slow movement of this front, a number of questions
remain. How much rain will fall across the region, will there be any
chances of severe weather, etc. For now will just mention beneficial
rains possible as do not feel that this will cause any flooding
since it will fall over a long period of time. The warmest day will
be Monday, with highs in the mid 60s to low 70s, then beyond that
temps will depend on cloud cover, precipitation and location of cold
front. For now slowly lowered temps through midweek with front
finially exiting region.

Beyond that, extended models continue to show active pattern with
additional chances of rain late Thurday night into Friday.

Byrd
&&

.AVIATION...  (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1125 AM CST Fri Feb 16 2018

System exiting to our east, so ridge of high pressure building in.
Will see winds lighten and veer to the north, then east later
tonight. As for clouds, clearing from north to south. Still have
MVFR cigs over STL metro which should lift to VFR by 20z.
Otherwise, next system to approach area Saturday morning with mid
and high clouds sliding back in from the southwest. A lot of dry
air to overcome, so precipitation will be slow to develop. Kept
tafs dry for now.

SPECIFICS FOR KSTL:
System exiting to our east, so ridge of high pressure building in.
Will see winds lighten and veer to the north, then east later
tonight. As for clouds, clearing from north to south. Still have
MVFR cigs over STL metro which should lift to VFR by 20z.
Otherwise, next system to approach area Saturday morning with mid
and high clouds sliding back in from the southwest. A lot of dry
air to overcome, so precipitation will be slow to develop. Kept
tafs dry for now. Will see cigs dip back down to MVFR at KSTL by
18z Saturday.

Byrd

&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     29  48  31  59 /   5  40   0   5
Quincy          23  45  26  56 /   5  30   0   0
Columbia        27  49  29  61 /  20  40   0   0
Jefferson City  27  50  28  61 /  20  50   0   0
Salem           29  44  30  55 /   5  40   5   5
Farmington      29  48  30  57 /  20  70   0   5

&&

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

$$
WFO LSX



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