Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 091103
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
503 AM CST Fri Dec 9 2016
Issued at 312 AM CST FRI DEC 9 2016
Through much of the next 7 days, the upper pattern will be quasi-
zonal with a fast upper jet streaming overhead. While this implies
no significant upper storm systems, we will see several quick-hitting
light precipitation events through late next work week.
The first event should develop late Saturday night/early Sunday. At
the surface, high pressure is expected to move into the eastern half
of the CONUS Saturday. This will shift winds around to the south and
allow for some moderation of temperatures into the upper 30s/lower
40s Saturday. Overnight lows though are expected to fall below or
near freezing. As a fast moving upper system moves into the area
during the overnight hours, light precipitation is expected to
develop during the morning hours. There remains several degrees of
variance between models at the onset of precipitation Sunday morning
but it`s possible there may be a brief period of freezing drizzle or
freezing rain before warm advection warms temperatures above
freezing, changing precipitation to all liquid. This transition area
may lift northward through the morning hours as things warm up.
Fortunately, any icing looks to be very light and perhaps just a
trace to hundredth. But this is enough to still cause slick roads for
anyone out Sunday morning. As the upper system pulls away and cold
air surges back into the region, there may be a period of light mixed
precipitation to light snow as the cold air deepens. Again this looks
to be very light with little or no ice and only a few tenths of inch
of snow in far northern Missouri. Heavier snow amounts should stay
well north of the forecast area.
The next light precip event should move into the area Tuesday night
into Wednesday. This will correspond to another surge of Arctic air
into the area. In the post-frontal cold advection, another fast-
moving upper wave sweeps through the area. The forcing associated
with this wave seems to be enough to saturate the column and with
cold air in place, light snow develops. While there`s still a fair
amount of uncertainty with where the snow develops, the ECMWF is
further south than the GFS and the Canadian, it`s going to be very
cold, likely colder than the current spell of cold air.
.Aviation...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 503 AM CST FRI DEC 9 2016
VFR conditions are expected as high pressure moves into the area.
This will also keep winds light through the forecast. While winds
will be variable this morning and early this afternoon, winds should
become light out of southeast this evening. Only mid to high level
clouds are expected through the period.