Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

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FXUS63 KEAX 251122
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
522 AM CST Thu Dec 25 2014

.DISCUSSION...
Issued at 342 AM CST THU DEC 25 2014

Water vapor imagery showing deep positively tilted trough digging
along the West Coast this morning with low amplitude ridging
downstream across the Plains and Lower Missouri Vly. Temps this
morning largely residing in the lower 30s...with regional VAD wind
profiles showing a notable increase in recent hrs thanks to a
strengthening pressure gradient across the Nation/s Heartland. As has
been highlighted in recent days...ridging aloft combined with strong
thermal advection will allow for a warm Christmas Day with upper 40s
to lower 50s expected area wide this afternoon. Of concern however
will be the strengthening winds with all available guidance
suggesting sustained winds of 20-25 kts...with higher gusts /30-35 kt
range/later today. Toyed with the idea for a wind advisory across
western sections of the CWA...however have decided to hold off as
best pressure fall couplet expected to move into our region late in
the day. This should allow highest peak heating winds to occur
across the High Plains into central KS...with slightly weaker winds
downstream into our area. Regardless...this Christmas Day promises
to be warm /10-15 degrees above normal/ and breezy.

Next weather feature of interest will arrive by Friday afternoon as a
cold front starts to approach from the northwest. Out ahead of this
boundary...warm air advection and weak isentropic upglide will result
in developing -RA/DZ Friday afternoon...with a continuation right into
Saturday morning. In contrast to last night/s model runs...feature
looks much more progressive which should result in precip exiting
stage right by early Saturday afternoon. What looked like a possible
region wide snowfall is looking less and less ominous this morning as
fcst soundings show very poor moisture aloft in the ice crystal
growth region. That said...cannot rule out some light accumulations
Fri night/early Sat but accums will likely remain well under an
inch.

Heading into next week...main story will be the return of very cold
weather following the passage of a cold front Monday
afternoon/night. GFS and ECMWF very much in agreement that an airmass
with origins to northern Canada will dive south across the Plains and
Midwest as high pressure of nearly 1050-mb builds south along Front
Range. With clear skies at night...overnight lows may extend into
the single digits/lower teens Wed and Thurs mornings with highs
struggling to reach the 20 degree mark. As we stated
yesterday...enjoy the warm weather today while you can!

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 522 AM CST THU DEC 25 2014

VFR conditions expected through the fcst period with passing upper CI
aloft. Morning radar VWP data showing 35kt winds at 2 kft as low-
level speed max approaches. Have maintained LLWS mention through 15z
to account for a rapid speed increase and directional change just off
the deck. Winds will continue to increase today with 30+ kt gusts
possible at IXD and MCI later this afternoon. Wind should begin
subsiding by late early evening with loss of daytime heating.

&&

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

$$

DISCUSSION...32
AVIATION...32







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