000
FXUS63 KEAX 030549
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1149 PM CST Mon Dec 2 2013

.SHORT TERM...(This Evening through Tuesday Night)
Issued at 340 PM CST MON DEC 2 2013

Short term concerns will once again center on fog, possibly dense,
formation later tonight and its areal extent. Then next challenge
will be timing of the much anticipated Arctic cold front.

For tonight low-level moisture remains in place and going nowhere
with southerly winds continuing. While the fog/stratus finally
eroded late this afternoon do anticipate it reforming overnight,
initially most likely over the areas which were last to
clear...meaning the far southern counties as well as it spreading
into northeast MO. Timing-wise after midnight but can`t rule out
earlier owing to the late dissipation today. SREF and NAM/RAP
condensation pressure deficit progs have performed well and they all
support the above scenario as well as a westward spread into west
central MO, including the KC Metro, towards sunrise.

The Arctic cold front will likely remain just northwest of the CWA
during the daylight hours of Tuesday, allowing one last day of much
above average temperatures. If the morning fog/stratus can dissipate
by late morning then a good chance entire region will see highs in
the 60s. Continue to favor the faster NAM/GFS solutions on cold
front advancement. Per coordination with adjacent offices have used
a 50-50 blend of the NAM/GFS which do a better job with the gusty
northwest winds in the post-frontal environment. Will leave current
forecast dry although post frontal stratus could yield a few
sprinkles.

.LONG TERM...(Wednesday through Monday)
Issued at 340 PM CST MON DEC 2 2013

For the last few days, coarser scale models have been indicating a
relatively narrow corridor of snow from east central Kansas through
central Missouri. The higher resolution NAM continues this trend but
the better resolution provides a bit more detail and confirms that a
narrow band is more likely. First, a fairly tight baroclinic region
should setup across the southern half of the forecast area. This
elevated boundary, which shows up well at around 850mb to 800mb
should then be activated by a weak wave moving out of areas to the
southwest. This will occur underneath a strong upper jet with the
right rear quadrant of the upper jet streak enhancing lift over the
area. Strong frontogenesis is then expected to develop as the
theta-e gradient tightens. The strong coupled forcing will be
quick-lived but will likely lead to at least several inches of snow
during the day Thursday and into the evening hours. While it looks
like there will be at least light snow across a good portion of the
forecast area, any accumulating snow looks to occur in a very narrow
corridor. These types of systems are inherently difficult to pin
down so even what it depicted now in the forecast is very likely too
broad, with a location that will be probably be /fine-tuned in the
coming days.

Otherwise, the bitter, unseasonably cold temperatures will persist
through the remainder of the forecast with highs in the 20s and lows
in the single digits to teens. The long wave trough responsible for
this pattern shift shows no signs of easing and strong high pressure
centers continually reinforce the already cold air mass.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday Night)
Issued at 1140 PM CST MON DEC 2 2013

Fog is beginning to form across most of the forecast area ahead of
anticipated time frame. As a result have added lowered visibility for
all terminals with deterioration of conditions through the overnight
hours. For the next several hours the terminals may only bounce
between VFR and MVFR/IFR, so handled that threat with Tempo groups.
Toward the sunrise hours more prevailing foggy conditions should
arrive. After early to mid morning conditions will revert back to
VFR. Frontal passage will likely take place at KSTJ with southerly
winds going northerly very late in the TAF period, will likely add a
group for wind shift with the 12z issuance for KSTJ and perhaps for
KMCI and KMKC.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

SHORT TERM...MJ
LONG TERM...CDB
AVIATION...Leighton