FXUS63 KEAX 050936
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
336 AM CST Sun Feb 5 2012

.DISCUSSION...

Today - Tonight:

The upper low that has affected the region over the last few days
continues to weaken as it spins over northwestern Missouri. Warming
cloud top temperatures per IR satellite, decreasing radar returns and
increasing ceilings and visibilities all confirm the weakening of the
system. This trend will continue as the low slides southeast into
central Missouri and any remaining precipitation will be confined to
the vicinity of the low so have added low pops through our
southeastern zones to account for this. Any precipitation should be
out of the forecast area by mid to late morning so have kept the
afternoon period dry.

Outside of the lingering precipitation chances, today's cloud
forecast is rather difficult. The clouds associated with the upper
low should move south and east/erode through the day. But 11-3.9u
satellite imagery reveals an area of very low stratus and fog moving
southward through Iowa and Nebraska. There may be a period of time
this morning when northern Missouri clears completely out and
coupled with recent snow across the far northwest corner of the
state could have dramatic effects on our temperatures due to
radiational cooling around sunrise. I am not overly confident on the
timing of either cloud element in our north so have tended to play
the middle ground with regards to temperatures there. Models have
very poor handling of the low stratus but see no reason why it won't
progress southward into northern Missouri by mid morning or so,
further limiting any warm up in that part of the forecast area.

For tonight, while quiet weather is expected, models continue to
struggle with the effects of the new snow cover to our north and
northwest. The latest SREF visibility and ceiling probability
forecast indicate an increasing potential for low clouds and lower
visibilities across our north. Have therefore added a mention of fog
across northern Missouri as this makes conceptual sense given the
moist and cool boundary layer.

Monday:

Quiet weather is expected for this period as the upper level energy
that brought the region snow has been split apart, with one piece
heading east and another that has gotten cutoff within the upper
ridge over western North America. Mostly clear/clear skies are
expected and we should be able to warm back into the mid to upper 40s
for most locations and even a few 50 degree readings are possible in
our southern zones.

Monday Night - Tuesday:

The above mentioned cutoff portion should begin to eject eastward
through the Central Plains, aided by another wave diving southward
out of Canada. This will bring a chance for precipitation across the
forecast area by mid day Tuesday and with a very strong, 1040mb high
pressure surging down the Plains behind the Canadian system, enough
cold air will be move into the region bring a chance for light snow
to the forecast area. The GFS seems to the most robust with this
system with other models offering up a weaker system with less QPF.
So this system will need to be watched for the potential for light
accumulating snow. Temperatures Tuesday may not budge much from
overnight lows, especially across northern Missouri, given the cloud
cover and warm advection and highs in the lower 30s are expected
across that part of the forecast area.

Wednesday - Sunday:

Dry weather is expected to prevail through the extended period. With
a ridge developing over the western CONUS and deep troughing over
the east persisting into the later half of the week, we should see
northwesterly flow across the Central Plains. This should keep us
close to or just above normal for most the period with the possible
exception of Friday, when a colder airmass moves into the eastern
Plains/Midwest in response to the deepening eastern trough. There is
quite a bit of spread amongst the models, both deterministic and
ensembles, with how deep the trough digs but by the end of the
weekend, flow should become less amplified and a return to above
normal temperatures is expected.

CDB

&&

.AVIATION...

Precip has changed to snow over the past hour as upper low shifts
over the terminals. Some local enhancement can be expected over the
next 1 to 3 hours, with conditions averaging low IFR visibility and
low IFR to LIFR ceilings in light snow. Improving conditions KSTJ
after 08Z and KMKC/KMCI between 09 and 10Z. Winds north-northwest
around 8 knots.

VFR conditions expected for the balance of the period, unless skies
clear prematurely before daybreak which would promote the potential
for dense fog.

Will need to monitor LIFR stratus over ern SD/NW IA for any
potential to migrate south toward the terminals by mid-morning. RUC
does show a plume of 925mb RH moving this way, so this deck will
need to be monitored for further development.

Bookbinder

&&

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

$$

WFO EAX



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