Area Forecast Discussion
Issued by NWS St. Louis, MO

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631
FXUS63 KLSX 301216
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
716 AM CDT SAT APR 30 2016

.SHORT TERM...  (Through Late This Afternoon)
Issued at 331 AM CDT Sat Apr 30 2016

It will be an active day today. Current batch of showers and a few
thunderstorms to continue lifting northeast, slowly exiting from
southwest to northeast by midday. Then another piece of energy to
slide east across northern Missouri this afternoon and evening
helping to lift surface low off to the northeast. Models in pretty
good agreement, developing a line of convection just ahead of cold
front associated with surface low. If atmosphere is able to recover
from morning convection, decent CAPES between 1000-2000 J/kg, lapse
rates, and shear, could support some supercell development. SPC has
kept areas along and south of I-70 in a slight risk for severe
weather with the main threats being large hail, damaging winds and
possibly a few tornadoes.

As for high temperatures, it will be similar to yesterday with a
wide gradient from around 60 far north to the mid 70s south.

Byrd

.LONG TERM...  (Tonight through Friday)
Issued at 331 AM CDT Sat Apr 30 2016

(Tonight)

Storms to lift northeast out of forecast area by 03z Sunday, with
just some lingering showers slowly tapering off. Lows will be in the
upper 40s to upper 50s.

(Sunday through Friday)

Closed upper level low over Nebraska to open up and lift out of
region on Sunday. Will see showers and a few thunderstorms across
the area on back side of system before precipitation comes to an end
Sunday evening.

Surface ridge to build in with cooler temps for beginning of work
week. Highs on Monday will only be in the low to mid 60s, a bit
below normal for this time of year.

Weak surface ridging to remain over region through rest of forecast
period. Some models wanting to have upper level shortwaves under cut
the ridge with some low chances of precipitation towards end of work
week. For now kept this period dry with near normal temps in the mid
60s to mid 70s.

Byrd

&&

.AVIATION...  (For the 12z TAFs through 12z Sunday Morning)
Issued at 629 AM CDT Sat Apr 30 2016

Widespread area of precip assoc with a warm fnt is on schedule to
clear the remaining terminals over the hr or two. CIGs lowered to
IFR in the rain overnight but should slowly improve this mrng
along and south of I70 as a warm front lifts north. The warm front
is fcst to lift into nthrn MO and cntrl IL by late aftn/early
evng. This puts KUIN right on the edge of IFR conditions N of the
bndry and VFR to the S. I am not confident with KUIN/s fcst...CIG
or wind. There will be a break in the precip for the bulk of the
day after the mrng precip exits NE before another round of
convection dvlps along a cold front late this aftn/early this evng
across ern MO and SW IL but should only last an hr or so at any
given location. After that activity passes E...winds should
become wrly behind the cold front.

Specifics for KSTL:

Precip should be out of the terminal by 13Z with slowly improving
CIGs thru the mrng. Winds will gradually become Sthrly by aftn as
a warm front lifts thru which will allow CIGs to continue to
improve to VFR by aftn. Another round of scttrd convection is fcst
to dvlp drng the late aftn/early evng across ern MO. Coverage of
this activity may limit any impacts to the terminal...though even
a direct hit by a TSTM should last less than an hour. After this
passes...expect VFR conditions for the rest of the prd.

2%

&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     73  57  69  49 /  90  50  30  10
Quincy          63  50  59  45 /  90  40  50  10
Columbia        72  50  63  47 /  60  30  30  10
Jefferson City  75  51  66  48 /  50  30  20  10
Salem           70  59  70  50 /  90  50  40  10
Farmington      73  54  72  48 /  90  50  20  10

&&

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

$$

WFO LSX



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