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000
FXUS63 KTOP 142333
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
633 PM CDT Mon Apr 14 2014

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Tuesday)
Issued at 337 PM CDT MON APR 14 2014

Clear skies returning to much of Kansas this afternoon as the
upper trough axis clears and dry air works in. Another, much
weaker upper wave was diving south through the Plains, with area
of weak surface low pressure, mid cloud and very light isolated
precipitation into central portions of Nebraska. Good mixing into
the cool air keeping winds gusts despite weakening pressure
gradient with dewpoints into the teens and lower 20s.

Winds should drop quickly tonight allow for good radiational
cooling...outside of the mid cloud. Expect some decreases in
coverage overall and dry low levels and shallow nature of moisture
to keep precipitation at bay, but the cloud will likely make hourly
temps a challenge. Should see cloud clear by late night to allow all
locations several hours of clear skies and little mixing for well
below freezing lows. Going freeze warning looks very reasonable for
freezing window.  South winds slowly increase for Tuesday with good
low/mid level warm air advection and only a bit of cirrus for a much
warmer day, in the upper 50s to middle 60s. Models differ somewhat
on low level moisture profiles, with GFS deeper with the moisture
leading to increasing dew points. Elevated fire danger still quite
likely for at least a few hours for locations in north central
Kansas, west of the recent thunderstorm activity.

.LONG TERM...(Tuesday Night through Monday)
Issued at 337 PM CDT MON APR 14 2014

Models are coming into better agreement and trending slightly
faster with an upper level shortwave amplifying over the central
plains Thursday. About the biggest difference between the models
is the NAM being somewhat colder and forecasting more snow through
the day. However the SREF probabilities for measurable snow are
not that impressive suggesting the NAM may be on the cool side.
Nevertheless think temps could be cool enough for some wet flakes
late Wednesday night and into Thursday evening based off the
thermal profiles from the GFS and ECMWF. Most solutions show good
forcing overspreading the forecast area as the shortwave amplifies
and develops a slight negative tilt. There also looks to be good
mid level frontogenesis with the wave and all the models saturate
the column. With this in mind have gone with likely POPs for the
entire area Thursday. With the trend to be slightly faster, the
forecast now shows POPs trending lower after midnight Friday and
the slight chance POPs have been removed from the daytime hours
Friday. This is no real instability to speak of Thursday so it is
looking to be a cold and wet day with the chance for some light
snow mixed in. Lowered highs a couple degrees with temps in the
40s for much of the area expecting little or no insolation.

For the weekend, there is a bit more uncertainty in the forecast.
The GFS and ECMWF want to lift out a southern stream wave late
Saturday. Although there are differences with the northern stream
and the GFS shows a progressive solution with a northern stream
shortwave moving into the great lakes by Sunday. The ECMWF has
backed away from any wave in the northern stream and now shows
nearly zonal flow to the north causing the southern stream wave to
hang up over the area through Sunday. Will maintain some low chance
POPs due to the possibility for some kind of wave to affect the
area. The forecast will likely need some adjustments as the
weekend approaches.

Strong southerly winds are possible Wednesday as the pressure
gradient increases ahead of the approaching cold front. some
models are showing that the pressure gradient may be strong enough
for wind advisory conditions. This will be something to watch on
later shifts. The strong southerly winds should help keep temps a
little more warmer Wednesday morning and through the day. Then a
cold front should knock temps back down for Thursday with the
clouds and precip preventing much of a warm up. The split flow
through the weekend should keep much of the cold air to the north
with moderating temps across the central plains with highs in the
60s and lows in the 40s.

&&

.AVIATION...(For the 00Z TAFs through 00Z Tuesday Evening)
Issued at 632 PM CDT MON APR 14 2014

VFR conditions expected through the taf period.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING from 11 PM this evening to 9 AM CDT Tuesday FOR
KSZ008>012-020>024-026-034>040-054>056-058-059.

&&

$$

SHORT TERM...65
LONG TERM...Wolters
AVIATION...Sanders