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
FXUS63 KLSX 282045

Area Forecast Discussion
National Weather Service Saint Louis MO
345 PM CDT THU APR 28 2016

.SHORT TERM...  (Through Late Tonight)
Issued at 339 PM CDT Thu Apr 28 2016

Still expect a dry night as upper ridge approaches the area from the
west and surface low moves over Indiana moves off to the east.
Clouds currently across northern Missouri and central Illinois will
slowly move south through the night as the low moves to the east.
Lows tonight will be slightly cooler than MOS guidance, particularly
where clouds have kept temperatures down today.


.LONG TERM...  (Friday through Next Thursday)
Issued at 339 PM CDT Thu Apr 28 2016

...Friday through Sunday...

Not too much change to going forecast as showers and thunderstorms
will begin to overspread the area on Friday.  It still appears that
likely or categorical PoPs will be needed Friday night into
Saturday morning as strong moisture convergence will lie
underneath decent ascent ahead of mid level trough. There is some
differences between the ECMWF/NAM vs. the GFS with the ECMWF/NAM
showing a slightly more northerly track with the surface low on
Saturday evening than the GFS. The ECMWF/GFS could bring more of a
severe weather threat, so will need to watch this closely. The
chance of thunderstorms will linger into Sunday before the upper
low moves out of the area.

...Monday through Thursday...

While the details differ, the overall idea of the GFS and ECMWF
is the same with the upper pattern becoming more amplified next
week.  Shortwave trough will move southeast out of the Canada early
next week and phase with upper trough moving east out of the
southwest CONUS. This will cause northwesterly flow aloft to
develop by midweek. Rain chances look minimal at this point in the
northwesterly flow with near normal temperatures as the GFS Mean
ensemble and the ECMWF 850mb temperatures will be in the 5-10C



.AVIATION...  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1235 PM CDT Thu Apr 28 2016

A rather large area of stratus covered the Upper MS Valley and
northern Plains into northern MO and through a good portion of
northern and central IL. The southern extent impacting KUIN was
located within cyclonic westerly low level flow, and stretched
just north and west of KCOU. KUIN will continue to see MVFR flight
conditions this afternoon which are expected to improve to VFR by
00z. Overnight however lower stratus and some light fog will
likely move back into KUIN and persist into Friday morning.
Elsewhere predominately VFR flight conditions are expected with
potential for MVFR stratus on and off at KCOU through late

Specifics for KSTL:

VFR flight conditions are expected through the forecast TAF
period. Westerly winds this afternoon will become light this
evening and veer with time.





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