000
FXUS63 KEAX 061441
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
841 AM CST Fri Dec 6 2013

.UPDATE...
Issued at 833 AM CST FRI DEC 6 2013

Based upon latest radar/satellite trends and 12z NAM output the
northern edge of the snow band moving across southern and east
central MO will barely graze the far southeastern CWA today. Thus,
have tightened up PoP gradient across the southern CWA. Snow is not
reaching the ground as surface obs across the CWA show ceilings 7-10k
ft while radar shows weak returns as low as 4k ft south of a Kansas
City to Kirksville line...signaling snowflakes are evaporating
before they reach the ground. NAM/GFS Bufr soundings show this very
dry sub-cloud region will remain intact through the rest of today.

&&

.SHORT TERM...(Today through Saturday Afternoon)
Issued at 337 AM CST FRI DEC 6 2013

The lower several thousand feet of the atmosphere remains extremely
dry and with limited lift over the region saturation into that
extremely dry sub-cloud layer has been difficult to achieve and
maintain. Radar trends and observations showed that only some light
snow or flurries hit the ground across the southern third of the
forecast area before the dry air reestablished itself. This trend
should persist through the day with any accumulating snow today
across our far southern zones or into southern Missouri. So have
continued the trend from the previous forecast and scaled back the
highest PoPs to this area. Have kept a mention of flurries through
the morning hours as far north as the Kansas City area as there may
be a few snow flakes survive the dry air this far north.

Temperatures will remain extremely cold for this time of year, about
20 to 30 degrees below normal. These temperatures will be reinforced
today with another stout high pressure building from the north. The
pressure gradient will be tight enough across the area today to
yield 5-10 mph winds with some gusts to around 15 mph. So while
temperatures climb into the teens and 20s, wind chill values will
make afternoon temperatures feel more like the single digits
above/below zero. Winds will weaken some tonight but it will still
be windy enough result in -5 to -15 degree wind chill values. This
is dangerously cold and anyone that is outside will need to be
protected from the elements. Conditions will improve slightly during
the day Saturday but those attending any outdoor championship games
will need to dress for bitterly cold conditions.

.LONG TERM...(Saturday Evening through Thursday)
Issued at 337 AM CST FRI DEC 6 2013

Saturday night - Sunday night:

The main concern in the extended period will come during this time
frame as an synoptic scale light snow storm is coming into focus.
This will come courtesy of a shortwave trough ejecting out ahead of
a broad upper trough across the Rockies. Did delay timing of snow
until after midnight Saturday night as dry air will be in place on
Saturday and model soundings indicate it may take awhile for the
column to saturate. Liquid QFP with this system looks pretty
meager...on the order of 0.05" across the southern CWA to as much as
0.2" across the northern CWA. However, despite the lack of moisture,
snow ratios will be in the 15:1-20:1 range which will produce a
broad swath of 1-3" of light powdery snow across the area...again
with the higher amount near the Missouri/Iowa border. The bulk of
the snow will fall during the day Sunday but linger across the
eastern CWA into Sunday night before coming to an end by midnight
Sunday night. Impacts for this event should be minimal as snow
amounts will remain light and accumulate slowly during the day
Sunday.

Monday - Friday:

Conditions through the work week will remain dry and cold despite a
warm up through the week. The aforementioned broad trough across the
Rockies will push into the Plains on Monday and shift over the
region while deamplifying on Tuesday. This will continue to keep
temperatures not only well below normal but below freezing. Monday
will be the coldest day of the week with highs in the low teens to
lower 20s. Tuesday, temperatures will start off very cold in the
single digits but, will rebound into the mid 20s to near 30.
Wednesday, upper flow becomes nearly zonal however cold surface high
pressure building into the area will keep highs in the mid 20s to
near 30. It won`t be until Thursday and Friday that temperatures
finally return to above freezing with highs in the 30s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 511 AM CST FRI DEC 6 2013

Expect VFR conditions today with overcast mid-level clouds around
8-10kft. There is the potential to see a few snowflakes or flurries
at the terminals this morning but no vsby restrictions are expected.
Otherwise, skies should become mostly clear tonight with just some
scattered high level cirrus clouds. Winds will be out of the north
for the duration of the TAF period, ranging from 10-15kts today
diminishing to 5-10kts tonight.


&&

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

$$

UPDATE...MJ
SHORT TERM...CDB
LONG TERM...73
AVIATION...73