000
FXUS63 KEAX 041122
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
522 AM CST Wed Dec 4 2013

.SHORT TERM...(Today and Tonight)
Issued at 325 AM CST WED DEC 4 2013

For today, the primary concern will be fog, stratus and drizzle
chances along and behind a southeastward moving cold front, with
measurable precipitation chances increasing as a shortwave trough
pushes northeastward across the CWA late this morning into the early
afternoon. Dry air above 800 mb will keep any precipitation amounts
very light, but extensive boundary layer moisture and a combination
of lift from the shortwave trough and weak convergence along the
925mb-850mb front may allow for at least light to moderate drizzle
if not light stratiform rain, especially in far north and northeast
MO. Dense fog may also continue into the mid to late morning near
the IA border even as northerly winds increase, due to advection of
moist near-surface air into the region, so will consider extending
the northern segment of the dense fog advisory if visibilities do
not improve after 12z.

Steady to falling temperatures are expected this morning across most
of the region, then afternoon temperatures will continually decrease
as colder air pushes in from the north. Highs will be reached early
this morning in far northwest MO, and during the mid to late morning
elsewhere, ranging from the mid 30s in the northwest to the lower
50s in the far southeast. Temperatures should stay above freezing in
areas seeing drizzle or light rain this afternoon, but will need to
be closely monitored in far northwest MO where the freezing line is
a bit closer. Precipitation will taper from west to east late this
afternoon as slightly drier air works in from the northwest and the
shortwave trough departs, keeping the overnight hours chilly but dry.

.LONG TERM...(Thursday through Tuesday)
Issued at 325 AM CST WED DEC 4 2013

Very little change to previous forecast, with the biggest refinement
to tightening northern gradient of snowfall accumulations for
Thursday-Friday period.

Several model members have a good degree of consistency of
placement of surface and synoptic features for Thursday into Friday,
lending increased confidence to forecast. Furthermore, the general
theme of model QPF is in modest agreement with placement/amounts,
with the biggest differences in handling the degree of dry air
advecting in from the north in the H7-H85 layer. This primarily
affects our forecast area in determining the northern extent of
accumulating snowfall. Went with a model consensus which keeps basic
theme from earlier forecasts: minor snowfall accumulations in the
far southeastern portions of the CWA, around 1 inch of snow along a
line from Mound City, KS to Sedalia, MO. A sharp drop off in snow
amounts are expected north of that line and likewise a large
increase with southward extent.

After a lull in the weather for late Friday afternoon and Saturday,
an additional round of light snow is expected beginning late
Saturday night into Sunday night for the entire forecast area as a
large upper trough approaches from the Four-Corners region. While
models are relatively consistent on timing, a larger spread with the
degree of lift/moisture over the area yields some uncertainty to
total snowfall amounts. Currently, most areas may expect to see
around 1 inch of snowfall from this episode, but amounts may vary as
the upper system is better sampled/resolved with time.

Temperatures continue to look bitterly cold and persist into at
least middle next week. Following today, temperatures are expected
to remain below freezing through at least Wednesday. High
temperatures will only reach the teens and 20s, with a few nights
potentially falling into the single digits.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 522 AM CST WED DEC 4 2013

Dense fog with surface visibilities between 1/4 to 1/2 mile will
continue to develop across northern Missouri this morning, while
patchy dense fog will be a bit more transient in nature along and
south of I-70. IFR to LIFR stratus will also continue to stream down
from the north, impacting all but far southern parts of the forecast
area. Visibilities and ceilings should gradually improve during the
late morning and early afternoon hours, eventually becoming fully
VFR throughout the region by 00z Thursday. Winds will increase out of
the north northwest over the next 2-4 hours, gusting briefly to 25
kts especially in northern Missouri.

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...DENSE FOG ADVISORY until 8 AM CST this morning FOR KSZ057-060.

MO...DENSE FOG ADVISORY until 8 AM CST this morning FOR MOZ002>008-
     015>017-043>045-053-054.

&&

$$

SHORT TERM...Laflin
LONG TERM...Blair
AVIATION...Laflin