000
FXUS63 KSGF 060535
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1135 PM CST Thu Dec 5 2013

.UPDATE...
Issued at 805 CST THU DEC 5 2013

The winter storm continues to impact the region this evening. The
wintry mix of precipitation that impacted portions of the area
today has changed over to all snow early this evening except for far
south central Missouri where a mix continues. This mix of wintry
precipitation will change over to all snow by midnight tonight if
not sooner.

The snowfall is currently occurring along and south of Interstate
44 with a lull in the snow occurring north of the Interstate 44
corridor. Light to moderate snow will continue to affect southern
Missouri south of Interstate 44 this evening, with the snow
expected to expand northward during the overnight hours into
Friday morning. The snow will then taper off from west to east
Friday afternoon coming to an end late Friday afternoon.

IR satellite imagery is showing cooling cloud tops across Oklahoma
into Texas ahead of the upper level trough swinging east into the
plains. A strong upper level jet is also developing to the north
with the area being in the right entrance region of the jet. This
will result in the light to moderate snow continuing through the
overnight hours into Friday morning. Temperatures are currently in
the 20s and will drop into the teens overnight. These cold
temperatures will allow high snow to liquid ratios with 15:1 if
not higher snow ratios occurring tonight into Friday morning. With
the snow expected to continue this evening along with the high snow
ratios...we have increased snow amounts some. Storm total snow
falls including what fell this afternoon are now expected to be
1 to 3 inches north of Highway 54, 3 to 6 inches south of Highway
54 to north of Interstate 44, with 6 to 10 inches generally along
and south of Interstate 44 with locally higher amounts to 12
inches possible across far southern and south central Missouri.

Updated products have been sent.

&&

.SHORT TERM...(This Evening through Friday)
Issued at 224 PM CST THU DEC 5 2013

Snow has expanded this afternoon across the I-44 corridor...as
upper level ascent strengthened enough to overcome low level dry
air. Short term model guidance has hinted at the possibility of
mid level frontogenesis increasing across northern Arkansas and
southern Missouri over the next couple of hours, which could
result in an additional uptick in precipitation intensity heading
into the evening hours.

For areas along the greater I-44 and U.S. 60 corridors,
precipitation has either changed over entirely to snow, or will
very shortly. Once that transition takes place, precip should,
for the most part, remain all snow through the remainder of the
event. While snow across this area should remain fairly light
through the evening hours, it will likely have impacts on the
evening rush hour given cold ground and air temps. Would expect to
see a dusting to two inches of snow accumulation by mid to late
evening.

For the remainder of the afternoon across southern and south
central Missouri, a mix of sleet, snow and freezing rain will
remain possible, with precipitation transitioning to a mix of
sleet and snow, and then all snow by late evening. Accumulations
will remain fairly light through evening across this area as well,
but impacts to travel will certainly continue through the evening
drive home.

By mid evening, we should see a lull in precipitation, especially
north of U.S. 60, and at the very least a decrease in intensity
further south.  By midnight or so, another wave of precipitation
will begin to overspread the area. By this point, expect to see
all snow for the vast majority of the CWA. The only exception may
be the far southeastern corner, where a mix of snow and sleet will
be possible for a few hours before finally changing over. This
snow should continue into mid day Friday, before clearing from
west to east.

Tonight`s snow still looks to be the more significant in terms of
accumulations, given good lift and rather high snow to liquid
ratios.  When all is said and done, am still expecting to see
snowfall of 1 to 3 inches north of I-44, a gradient of 3
to 6 inches of snow across the great I-44 corridor, and then 4 to 8
inches of snow across southern and south central Missouri.  Given
dry air to our north and continued north winds, there will probably
be a fairly sharp gradient to snowfall along and just north of
I-44.

Snow should be out of the area by tomorrow afternoon at the latest,
with clearing skies by tomorrow evening.  That will set the stage
for a very, very cold night to start the weekend.

.LONG TERM...(Friday Night through Thursday)
Issued at 224 PM CST THU DEC 5 2013

A strong Arctic high pressure system will move over the Ozarks
region Friday night into Saturday and bring bitterly cold
temperatures to the area. Saturday morning lows are expected to be
between 0 and 5 degrees above with wind chills around 10 below. If
these temperatures occur, a Wind Chill Advisory may need to be
considered.

Despite mostly sunny skies on Saturday, the Arctic airmass will only
allow temperatures to climb into the upper teens to lower 20s. The
temperatures will also be impacted by the snow cover from Thursday
and Friday`s winter storm.

The Arctic airmass will slide northeast of the region through the
day Saturday as another winter system begins to move towards the
area. The latest model runs have begun to taper back the snow
amounts expected for Saturday night and through the day Sunday.
Also, there is some concern that if precipitation does occur Sunday
that a loss of cloud ice depicted by the models for Sunday afternoon
would transition any precipitation over to light sleet or
freezing drizzle before coming to an end Sunday evening. One thing
that may work to overcome this might be the good isentropic ascent
noted on the models, but this will need to be watched as we head
into the event Sunday.

Behind the system for Sunday is another reinforcing shot of Arctic
air which will keep the region very cold into the end of next week.
Lows on Tuesday morning are expected to be very cold with most areas
along and south of I-44 at or below 3 degrees for morning lows.
Areas to the north will be slightly warmer in the upper single
digits, likely as a result of lower snow amounts from the snows on
Thursday/Friday and on Sunday. Some locations along the Plateau
may see wind chills fall to near 10 below again.

A very slow warming trend is expected towards the end of next week
with temperatures forecast to climb above the freezing mark for the
first time next Thursday. Temperatures are expected to climb into
the lower to middle 30s.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1128 PM CST THU DEC 5 2013

Light snow will persist for much of tonight at the Springfield and
Branson aerodromes with flight conditions varying between MVFR and
IFR. Joplin will see periods of light snow with flight conditions
dropping into the IFR category with any steadier snow. There may
be a brief lull in snow intensity late tonight before snow
increases again Friday morning. IFR visibilities are expected for
much of Friday morning as the snow increases. The snow will then
taper from west to east Friday afternoon with flight conditions
beginning to improve. There is still an indication that a brief
period of freezing drizzle will be possible as the snow comes to
an end.

&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER STORM WARNING until 6 PM CST Friday FOR MOZ082-083-
     090>098-101>106.

     WINTER WEATHER ADVISORY until 6 PM CST Friday FOR MOZ055>058-
     066>071-077>081-088-089.

KS...WINTER WEATHER ADVISORY until 6 PM CST Friday FOR KSZ073-097-101.

&&

$$

UPDATE...Wise
SHORT TERM...Boxell
LONG TERM...Hatch
AVIATION...Schaumann