Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 112337
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
537 PM CST Wed Dec 11 2013
.SHORT TERM...(Today through Thursday)
Issued at 252 AM CST WED DEC 11 2013
A strong clipper system is currently tracking through Iowa and
spreading light snow to that area. There may be some flurries make
into northern Missouri but cloud bases are above 10K feet so the
chances are pretty low. The bigger issue, and most sensible for us
is the arctic front that is currently moving through northwestern
Missouri. Strong cold advection is expected behind the front and
it`s likely that most of northern Missouri and northeastern Kansas
has seen their high temperatures for the day. Daytime high
temperatures will range from the teens to the 20s across the area.
Wind chills will also be bitterly cold as a 1040+mb high pressure
area builds into the region. The pressure gradient through the
morning hours will support winds around 15 mph with gusts as high as
25 mph. This will lead to wind chill values of 5 to 14 degrees below
zero, during the day, across northern Missouri.
Fortunately the strong high pressure will travel quickly across the
region, moving to our south and east by early Thursday morning. This
means winds will quickly switch to the south overnight with
temperatures warmer later in the night than earlier. The southwest
winds will also lead to daytime highs back into the mid/upper 30s in
our southwest and the upper 20s in northeastern Missouri.
.LONG TERM...(Friday through Tuesday)
Issued at 252 AM CST WED DEC 11 2013
Main concern in the extended period revolves around precipitation on
Friday/Friday night and, more importantly, the precipitation type.
It is the latter that is the very challenging part of this forecast
as there are likely to chance POPs in the forecast for Friday/Friday
night. The player in producing the precipitation will be an upper
level shortwave trough moving into the Southern/Central Plains on
the day Friday which will move through the area Friday night.
Now to try and figure out the tricky precipitation type. Friday
morning cold air will be in place across the area with morning lows
in the mid teens to mid 20s. Gulf moisture will stream northward out
ahead of the aforementioned upper level shortwave into the cold air
in place. Model soundings indicate there will be a significant warm
nose aloft above freezing at the onset of precipitation over the CWA.
This would provide for a freezing rain or sleet scenario. However, by
the afternoon hours, model soundings indicate the warm nose will cool
while surface temperatures move just above freezing (especially
along and south of I-70). The whole column will be above freezing
across the extreme southern CWA leading to all rain. However, further
north, sleet appears to be the more likely p-type. Friday night we
will experience diurnal cooling as well as a cold frontal passage
which will allow for rain/sleet to eventually turn over to snow
during the night time hours and continue into early Saturday morning.
There may initially be a few hundredths of ice accumulation Friday
morning across the southern CWA however as we move into Friday
afternoon that will gradually melt as we move above freezing.
Otherwise expect an accumulation of sleet and snow through Friday
night (Friday across the north) into Saturday morning ranging from
half an inch across the northwestern CWA to around 2 inches across
the eastern CWA.
The remainder of the weekend into Monday then looks benign as far as
sensible weather goes however, it will continue to remain cold. This
will be due to northwest flow aloft and a series of cold surface
high pressure areas traversing the region. High temperatures will
range from near 20 to the lower 30s on Saturday and Sunday. Monday
northwest flow will relax and highs will range from the mid
20s to upper 30s. There will be a slight chance for snow on Tuesday
as a shortwave moves through the region however, most models keep
this feature north of the CWA.
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 537 PM CST WED DEC 11 2013
No significant visibility or ceiling restrictions are expected
through the TAF period. Winds will gradually transition from light
and variable tonight to southwest at around 10 kts by mid morning