Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 231132

632 AM CDT Tue Sep 23 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 328 AM CDT TUE SEP 23 2014

Upper trough making its way east out of the Central Rockies into
upper ridge over the Mississippi Valley. A rather sharp moisture
gradient existed ahead of the trough and south to southwest low
level trajectories were only allowing a slow modification to the dry
airmass and upstream precipitation from northwest Kansas into
northeast Nebraska early this morning had made slow east to
northeast progress since 0Z.

As the system comes east to just north of east today, isentropic
upglide and 700-850mb moisture convergence with the upper trough
weakens a bit today, likely at least in part due to diurnal
weakening of the low level jet, and short-range guidance is quite
similar with a slow drying trend to the precipitation. Still appears
western locations will see good coverage of precipitation early this
morning with what appears to be a weak MCV enter north central
Kansas at this writing. Should see a slow increase in intensity and
coverage tonight as upper trough axis sharpens bringing deeper
moisture on east in reinforced isentropic ascent. Far southeastern
locations will continue to be dominated by the dry low level
anticyclone and may well stay dry through tonight. Isolated to
scattered thunder still possible with modest elevated CAPE values
today and tonight. Bumped up temps a bit today with some late-day
clearing anticipated west and early day dry conditions east and

.LONG TERM...(Wednesday through Monday)
Issued at 328 AM CDT TUE SEP 23 2014

Upper trof remains over the Central Plains on Wednesday as it
slowly weakens with time. Scattered precipitation chances diminish
to just slight chances by the evening hours as lift wanes and
temperatures aloft warm. Kept slightly cooler highs for Wednesday
with clouds and precipitation in the area. As rain ends, clouds
diminish and southerly winds return for Thursday, have highs near
80 and a dry forecast.

For Friday through Monday, a blocking pattern with coastal
longwave trofs and a 590dm high over the Northern Plains will
bring a dry forecast with high temperatures remaining around 80.
By late in the forecast, the pattern begins to break down, but how
it does so differs in long range models. Either case sensible
weather should remain similar as the weekend and will keep the
forecast as such.


.AVIATION...(For the 12Z TAFs through 12Z Wednesday Morning)
Issued at 631 AM CDT TUE SEP 23 2014

VFR conditions anticipated. Precipitation in central KS appears to
be breaking up, but will carry VCSH for a few hours. Somewhat
better chances come in the latter portions of the forecast but
again impacts should be brief MVFR at worst. Some increase in wind
should occur as mixing depths increase in the next several hours.




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