Area Forecast Discussion
Issued by NWS Topeka, KS

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000
FXUS63 KTOP 111657
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
1057 AM CST Sun Feb 11 2018

...AVIATION UPDATE...

.SHORT TERM...(Today and tonight)
Issued at 316 AM CST Sun Feb 11 2018

Current WV imagery shows well defined mid to upper positively tilted
trough working into Central Nebraska and Western KS at this hour.
Low level dry advection moving in from the west with north central
Kansas locations scattering out fairly quickly.  Clearing will
continue and anticipate most locations under sunshine by mid morning
over the area.  There are some patchy areas of mist still being
reported over portions of east central KS.  Therefore, will carry
advisory for freezing drizzle for a few more hours until 13Z.  Will
allow other advisories to be expired this hour for western portions
of the area.

As the H5 trough passes subsidence will dominate the period and
surface high pressure will continue to build into the region.  High
temps will be held down over northern areas today with fresh
snowpack in place.  Only have temps in the southern zones reaching
around freezing highs topping out in the low 30s.  Main concern over
the period will be how low temps go under clear skies and calm winds
on Sunday night.  Expect overnight lows to be subzero at some
locations along the KS/NE state line and single digits in areas with
snowpack.

.LONG TERM...(Monday through Saturday)
Issued at 316 AM CST Sun Feb 11 2018

The Monday through Wednesday periods appear fairly straight forward
with dry and steadily warmer conditions. The upper low remains cut
off over southern California with west to southwest flow over the
central Plains. Monday brings increasing cirrus but enough warm-air
advection on southerly 850 mb winds for highs several degrees higher
for at least southern areas. Mid and high cloud with continued
veering winds over the boundary layer keeps Monday night lows 10-15
F warmer than tonight. A weak surface trough approaches the area
from the north Tuesday in association with a weak shortwave moving
across the northern Plains but south to southwest surface winds
should still be enough to push highs to the mid 40s to mid 50s. Low
level flow continues to veer to the west Wednesday for highs in the
mid 50s to mid 60s, with winds light enough and humidities high
enough to keep fire danger potential moderated.

Uncertainty increases rather quickly Wednesday night into Friday
with models diverging on the handling of the cutoff low as a
shortwave trough dives southeast out of the British Columbia. The
GFS keeps the cutoff low to the southwest, while the ECMWF and a few
GEFS members kick the weakening low east ahead of the shortwave.
Will have some mention of precipitation late Thursday into Friday
but little confidence in just where or when the better chances will
be. Temperatures will return to near normal levels by Friday as a
modified Canadian airmass builds in from the northwest, though upper
flow looks to back again for Saturday with more warming potential.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1057 AM CST Sun Feb 11 2018

Dry air with the surface ridge should keep VFR conditions over the
area.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Drake
LONG TERM...65
AVIATION...Wolters



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