Area Forecast Discussion
Issued by NWS St. Louis, MO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
277
FXUS63 KLSX 300833
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
333 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 06z TAFs through 06z Saturday Night)
Issued at 1102 PM CDT Fri Apr 29 2016

Cloud ceilings will continue to gradually drop into the MVFR
category at the taf sites overnight as an intensifying southerly
low level jet brings increasing low level moisture into the area.
Showers and thunderstorms have already moved into COU and the St
Louis metro area late this evening and this activity will
continue overnight and into the early morning hours as a large
area of showers and storms over southwest MO moves northeastward
into our area. Ceilings and visibilities may at least briefly drop
into the IFR category late tonight and early Saturday morning
with the rain or showers and embedded elevated storms. Most of the
showers and storms should shift east-northeast of the taf sites by
late Saturday morning as a warm front shifts northeast of the
area. Easterly surface wind will veer around to a south-
southwesterly direction Saturday afternoon after passage of the
warm front. There may be scattered storms redeveloping late
Saturday afternoon or early evening mainly in the St Louis metro
area.

Specifics for KSTL: Showers and a few storms will continue
overnight and into Saturday morning with the cloud ceiling
dropping into the MVFR category around 06Z Saturday. The ceilings
and visibilities will drop down into the IFR category at times
late tonight and early Saturday morning. Most of the showers and
storms should shift east-northeast of STL by late morning with
the potential of scattered storms redeveloping late Saturday
afternoon or early evening. The prevailing ceiling will become VFR
Saturday afternoon. Easterly surface wind will continue late
tonight, then veer around to a southeasterly direction Saturday
morning, and a southwesterly direction Saturday afternoon.

GKS
&&

.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 /  70  30  30  10
Jefferson City  75  51  66  48 /  70  30  20  10
Salem           70  59  70  50 /  90  50  40  10
Farmington      73  54  72  48 /  80  50  20  10

&&

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

$$
WFO LSX



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.