Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 221138

Area Forecast Discussion
National Weather Service Topeka KS
538 AM CST Mon Jan 22 2018

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 351 AM CST Mon Jan 22 2018

Early this morning an upper level low was located across northwest
KS. This upper low will track east across the northern half of the
state and will move east across northern MO this afternoon. At this
time the best mid level frontogenetical forcing was located northwest
of of the upper low and extended from northwest KS, northeast into
northeast NE. The heavy snow band will remain northwest and north
of the CWA Today. As the upper low moves east across the northern
counties of the CWA, we should see vertical temperature profiles
cool to near or below 0 deg C, as the upper low approaches and
stronger ascent begins to cool the vertical column, thus the light
rain this morning across north central KS will mix with and
change to snow after 12Z and continue through the morning hours.
The southern end of the stronger frontogenetical forcing will move
east across the northern counties and may provide stronger ascent
for continuous light snow and perhaps some bands of moderate snow
through the mid morning hours into the afternoon hours. northwest
winds will begin to increase later this morning from northwest to
southeast across the CWA as a surface low deepens across
northwest MO and shifts northeast into southern IA by this
afternoon. The surface pressure gradient will increase across the
CWA and northwest winds will increase to 20 to 30 MPH with gusts
of 35 to 40 MPH. The stronger low-level CAA will lag farther
northwest, thus temperatures may remain steady around to a few
degrees above freezing across the western counties with mid 30s
across the remainder of the CWA. The light rain will begin to mix
with snow across northeast and east central KS during the
afternoon hours. We may see a change over to wet snow during the
mid and late afternoon hours across east central KS but with
temperatures in the mid 30s, there should only be a light coating
of accumulation. The best chance to see 1 to 2 inches of snowfall
will be across north central KS during the morning and early
afternoon hours. There could be a slushy inch or two of snow
accumulations across Marshall, Riley, Clay and Nemaha Counties
during the early afternoon. Given temperatures near or just above
freezing, I don`t see much in the way of blowing snow, plus the
warmer surface temperatures will make the snow wetter and less
dry, so any blowing snow would be limited to areas that may see
higher snowfall rates, may be our northwest and north central
counties this morning and into the afternoon hours.

The snow will gradually end from west to east across the CWA during
the late afternoon and early evening hours. Overnight lows will drop
into the lower to mid 20s, so any moisture on area roadways may
freeze causing some slick spots.

.LONG TERM...(Tuesday through Sunday)
Issued at 351 AM CST Mon Jan 22 2018

The upper low across the Great Lakes and OH valley will fill into
an open wave and shift east across the eastern US through mid
week. An upper level ridge across the western conus will amplify
and move east across the plains Wednesday into Thursday. An upper
level trough will move into the western US and then lift east-
northeast across the plains Friday into Saturday. There may be a
chance for rain late Friday into Saturday morning across the
eastern half of the CWA, ahead of a surface cold front. High
temperatures will be in the 40s on Tuesday but will warm through
the workweek into the mid to upper 50s by Thursday and Friday. As
the upper trough and surface cold front moves east across the CWA
Friday night, high temperatures will cool back into the 40s during
the weekend.


.AVIATION...(For the 12Z TAFS through 12Z Tuesday morning)
Issued at 533 AM CST Mon Jan 22 2018

Low stratus will develop across the terminals through 14Z, with
ceilings of 500 to 900 feet. As northwest winds increase the
resulting mixing should bring ceilings up to low MVFR by late
morning. There will also be periods of light rain this morning
which will mix with and perhaps chance to snow in the late morning
at MHK and during the afternoon hours at KTOP and KFOE. The precip
should end early this evening. Northwest winds will increase to
around 20 KTS with some gusts of 25 to 30 KTS.


Winter Weather Advisory until 3 PM CST this afternoon for KSZ008-



LONG TERM...Gargan
AVIATION...Gargan is the U.S. government's official web portal to all federal, state and local government web resources and services.