Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 132128
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
328 PM CST SAT FEB 13 2016
Issued at 327 PM CST SAT FEB 13 2016
Main forecast challenges deal with weather type and headlines. The
forecast area is really being split by wintry weather, both
spatially and temporally, with snowfall in our northeast and light
freezing drizzle in our south. The snowfall will likely start earlier
(late this evening) than the freezing drizzle, which may hold off
unto closer to sunrise. Strong isentropic ascent will eventually
saturate the lowest several thousand feet of the atmosphere in north
central to northeastern Missouri. Have delayed onset of snow several
hours based on forecast soundings,the large temperature/ dewpoint
depressions on surface observations and the relatively high cloud
bases. Forecast soundings for the Kirksville area saturate around
midnight or perhaps a little later. Have waited until then to
increase PoPs into the likely range. Snow amounts in our northeastern
zones are still expected to be in the 1" to as much as 3" range in
Schuyler County. After coordination with neighbors, have issued a
winter weather advisory for our extreme northeastern counties,
including the Kirksville area.
The other aspect of this wintry episode is the potential for
freezing drizzle in the southern half of the forecast area.
Confidence in this is quite a bit lower than with the snowfall in
the northeast. First, the lowest several thousand feet never really
saturate. Second, by the time saturation begins to lower, the warm
front lifts through, warms the surface above freezing and desaturates
the sounding aloft. So there really only looks like a marginal
potential for several hours when lift is maximized coincident with
the greatest amount of saturation. This seems to be around the 12Z
time frame +/- an hour or two. However, freezing drizzle can have a
major impact on travel as it can be deceptive in it`s ability to
slicken roads. So it`ll be important for people who have to travel
Sunday morning to understand that roads may be slick. But for now,
confidence just isn`t high enough to issue an advisory at this time.
Another clipper system will move through Monday night/ Tuesday
morning. Forecast soundings show the lowest several thousand feet to
be above freezing, even all the way into the northeastern portions of
the forecast area. So for snow, the wave should have little impact
with regards to wintry weather in the forecast area and we should see
just rain or perhaps a rain/snow mix in our northern zones.
The rest of the forecast looks quiet regarding precipitation. An
upper level ridge will spread east with low level flow out of the
south. This will help temperatures soar to well above normal levels
by Thursday into Friday. Highs may be in the 70s in parts of the
forecast area Thursday and potentially into Friday.
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1118 AM CST SAT FEB 13 2016
VFR conditions with ceilings between 5 and 8 thousand feet are
expected through the rest of the afternoon and into the overnight.
Late tonight, ceilings are expected to lower to MVFR and possibly
into the 1500 to 2000 ft range. There is also a chance for light
freezing drizzle across eastern Kansas and western Missouri late
tonight and early tomorrow morning. The most likely timing for this
seems to be centered around 12Z give or take a few hours.
Temperatures are expected to warm above freezing late Sunday morning
with lower levels drying out, ending the potential for freezing
MO...Winter Weather Advisory from 9 PM this evening to 6 PM CST
Sunday for MOZ008-017-025-033.