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
FXUS63 KLSX 072040

Area Forecast Discussion
National Weather Service Saint Louis MO
240 PM CST Wed Dec 7 2016

.SHORT TERM...  (Through Late Thursday Afternoon)
Issued at 239 PM CST Wed Dec 7 2016

Area of light snow across parts of central MO is expected to
continue to sink south this afternoon and evening. Did pull PoPs and
mention of flurries a little further west with very dry boundary
layer in place. Still appears the accumulating snow will remain just
west of the CWA.

PoPs drop quickly this evening as forcing pushes out of the region.
Expect clouds to clear out overnight. While the CWA should be
completely clear by sunrise Thurs morning, expect mixing to increase
overnight with gusts around 20 kts by 12z. Have overall trended twd
a compromise of guidance for temps tonight.

As for temps on Thurs, while the area will remain under CAA with the
sfc ridge building into the region, a clear sky shud help push temps
upward with mixing as deep as 925 mb. However, given the cold air
under the ridge currently upstream, have still trended twd the
coolest guidance for Thurs.


.LONG TERM...  (Thursday Night through Next Wednesday)
Issued at 239 PM CST Wed Dec 7 2016

Main concerns during the long term are snow fall potential and
timing along with the cold weather. High pressure over the area will
slide into the Ohio valley by saturday morning. A progressive
shortwave will race over southern Iowa and into Indiana saturday
afternoon and evening. This will bring isolated chances of snow
showers to northeast Missouri into west central Illinois.

Attention then turns to the cold front which will provide better
chance for snow fall to areas north of I-70 with a rain/snow mix
more likely for areas south of I-70 Sunday. It is too early at this
point to speculate on accumulation amounts.  All precipitation
should end west to east with frontal passage late sunday night into
early monday morning. An even colder shot of air comes in behind the
front Tuesday into Wednesday.



.AVIATION...  (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1123 AM CST Wed Dec 7 2016

Have continued a VFR forecast thru this TAF period. There is an
area of SN over ern MO, with a small band stretching into central
MO currently. With the dry low level air in place, expect no more
than flurries at KCOU, with the forcing pushing south this
afternoon. Cigs shud lift and sct out later this evening. KUIN
should only see a bkn to ovc mid deck thru this evening.

Strong and gusty wnwly winds will pick up Thurs morning and
continue thru the afternoon hours.

SPECIFICS FOR KSTL/KSUS/KCPS: Continued a VFR forecast thru the
period. Expect cigs to lower this afternoon as a system approaches
the area. However, currently only some sct flurries are expected.
Strong and gusty wnwly winds will pick up Thurs morning and
continue thru the afternoon hours.





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