Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Kansas City/Pleasant Hill MO
1136 am CST Tue Dec 6 2016
issued at 300 am CST Tuesday Dec 6 2016
The initial push of the first round of cold air for the season has
arrived. A cold front has nearly pushed through the County Warning Area early this
morning with moderate cold air advecting into the area behind it.
This will keep highs in the mid 30s to near 40 today despite morning
clouds giving way to mostly sunny skies this afternoon. A surface
ridge of high pressure will build into the area tonight will lows
dropping into the low to mid 20s. This surface ridge will be the
precursor to snow on Wednesday providing the cold conditions. It
will also provide for very dry air in place as the quick moving
system moves through the region. Consequently, in may take a while
for conditions to saturate enough for snow to reach the surface.
Models have become fairly consistent in snow developing in the
afternoon and continuing through the evening. The greatest amounts
will fall south of the Missouri River where half an inch to one inch
will be likely. North of the river, expect just a dusting to half an
inch with areas near the MO/Iowa border getting no more than some
flurries. This system will exit the area Wed night before midnight.
Beyond the precipitation, this system will provide for another
reinforcing shot of cold air with highs Wednesday in the mid 20s to
mid 30s. Continued cold air advection behind the system Wednesday
night and will drop lows into the teens with highs only reaching the
low to mid 20s on Thursday. Winds will subside Thursday night as
another surface ridge of high pressure builds into the region.
Temperatures Thursday night will be the coldest of the season thus
far with lows in the upper single digits and lower teens.
Temperatures will begin to moderate on Friday and Saturday as
northwest flow aloft across the region relaxes and as warm air
advects back into the area behind the departing surface ridge on
Friday. Despite the being of moderating temperatures on Friday, they
will still be well below normal with highs in the mid 20s to near
30. Saturday, warm air advection increases as weak upper level
ridging builds into the region in response to an upper level trough
digging into the central rockies. It is this system that will bring
the next chance for precipitation. It currently appears that this
system will begin an rain or a mix Saturday evening but will change
over to snow as cold air gets ushered in behind a surface low which
is progged to track along the southern boundary of the County Warning Area. Minor
accumulations may be possible. This system is expected to exit the
area Sunday morning with surface high pressure moving into the area
drying out conditions in the afternoon. Temperatures Sunday and
Monday will be more seasonable with highs in the mid 30s to mid 40s.
Aviation...(for the 18z tafs through 18z Wednesday afternoon)
issued at 1135 am CST Tuesday Dec 6 2016
Gusty northwest winds will subside from west to east towards sunset.
Otherwise, VFR conditions with high clouds increasing after midnight.
Ceilings will lower but remain VFR through mid Wednesday morning.
Expect light snow to move into extreme east central Kansas by mid
morning and spread east-southeast from kc area southward during rest
of morning. MVFR ceilings developing southern portions of kc area
southward by late morning. Snow accumulations half inch or less after
15z across west central MO and east central Kansas.