Area Forecast Discussion

311
FXUS63 KLSX 031140
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
540 AM CST Wed Dec 3 2025

.KEY MESSAGES...

- Up to a dusting of light snow is possible (40-60%) this
afternoon and evening along I-70 and I-64.

- Well below average temperatures are expected tonight and Thursday
night, with near daily record lows at Quincy.

- Another round of light wintry precipitation is possible (20-40%)
  late in the weekend.


&&

.SHORT TERM...  (Through Late Tonight)
Issued at 335 AM CST Wed Dec 3 2025

Temperatures have dropped into the teens and the 20s early this
morning as most of the area is experiencing strong radiational
cooling over the snowpack.  Parts of the southern and eastern CWA
are seeing low clouds holding on or expanding in recent hours with
some fog over the far southern CWA.  Couldn`t rule out some patchy
freezing fog in the far southern CWA early this morning.  Regional
radars are showing a stripe of returns that the CAMS have moving
into the northern CWA by 12Z. Can`t rule out that there wouldn`t be
flurries or light snow over northeast Missouri with this so will
maintain 20 PoPs.

The better chance for precipitation will be with the mid level
frontogenesis that will develop this afternoon and this evening. The
NAM/GFS is showing the placement of the band closer to the I-70
corridor which is farther south than it was forecast to be this time
yesterday.  The HREF is still supporting 40-60% PoPs along and
behind the front as it move southeast through the CWA this afternoon
and this evening.  Even with the cold start, temperatures over the
central CWA will be able to climb up into the upper 30s allowing for
some rain to mix with the snow before it changes to all snow. The
band of snow will shift off to the south of I-70 this evening and
eventually dissipate as the upper trough moves off to the east.  QPF
totals are still expected to be very light with this narrow band
(

NWS LSX Office Area Forecast Discussion