Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 042153
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
353 PM CST THU FEB 4 2016
Issued at 352 PM CST THU FEB 4 2016
Short Term (Tonight - Saturday night):
Lacking a snowstorm to grab one`s attention will have to settle on
watching an elongated upper trough heading our way. Water vapor
satellite imagery shows two vorticity maxima, one near the 4-corners
and the other over southwest MT. Both are tracking southeast and by
process of elimination it`ll be the MT feature that will affect us.
Not expecting much affect on the sensible weather as low level
moisture will be lacking as noted by the dry wedge in the near
surface layer. Do think there will be sufficient mid level warm air
advection to generate a good deal of mid clouds and sufficient top-
down saturation to wring out widely scattered light rain
showers/sprinkles over the southeast 1/2 of the CWA Friday night.
Bufr soundings also suggest presence of ice crystals so can`t rule
out snow mixed in with the rain.
Progressive upstream shortwave ridging aloft won`t allow any cold air
advection to settle in so mild temperatures expected on Saturday
aided by at least partly cloudy skies.
Long Term (Sunday - Thursday):
The upper pattern becomes extremely amplified by early next week
with a very deep and expansive upper trough east of the MO River and
a sharpening upper ridge over the western U.S. While the AO is
trending towards negative it`s hard to say this cold shot is a
result of it warm air advection spreads back into the picture by
Thursday, Wednesday if the more progressive GFS is to be believed.
The brief surge of arctic air is expected to overspread the region
beginning Sunday night as a second upper trough, stronger than Friday
night`s version, dives southeast across the Northern/Central Plains
and MO River Valley. With the Gulf of Mexico not opening up until
the cold front is east of us and the best dynamics also east of us
this system will have to rely on the moisture it brings with it for
any precipitation in our CWA. Believe there will be enough wrung out
for scattered snow showers/flurries Sunday night through Monday.
Seeing the strength of the deepening process with this upper trough
and long fetch on the backside of the surface low am a bit concerned
we are underestimating the strength of cold air advection and thus
the model blend being used may be too warm for Monday and Tuesday.
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1138 AM CST THU FEB 4 2016
VFR conditions with little in the way of sensible weather issues.
Modest southwest winds will veer to the northwest early this evening
as weak surface trough moves through. Will see increasing higher
based VFR ceilings tomorrow.