Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 271759

1259 PM CDT Sat Sep 27 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 347 AM CDT SAT SEP 27 2014

Weak upper low remains just to the northeast, with slow northward
movement noted in recent water vapor imagery. Low level moisture not
quite what it was Friday morning and not expecting and anything more
than isolated showers early this morning. Continued mid level dry
air advection from the south despite some increase in potential
vorticity aloft should keep the daytime hours dry. Slightly cooler
850mb air from the SSE should keep temps a degree or two lower than
those of Friday. Models again similar with 700-800mb layer becoming
increasingly saturated in mainly north central Kansas tonight on
modest 305K surface isentropic upglide and combine with modest
elevated instability for small convective chances, mainly after
midnight as these processes increase.

.LONG TERM...(Sunday through Friday)
Issued at 347 AM CDT SAT SEP 27 2014

An upper level trough will be located across the Mid Missouri Valley
into northeast Kansas on Sunday. Models continue to show the upper
low moving southeast through the day and into Missouri with a lobe
of energy rotating through the base across northeast Kansas
increasing upward vertical motion. Isolated showers and
thunderstorms will be possible and have left in the forecast. Most
areas are likely to remain dry with temperatures warming into the
lower to middle 80s.

Dry weather is expected to last into early Tuesday with a ridge
building across the Central Plains ahead of an approaching upper
trough in the western state and Rockies. Highs in the 80s with lows
in the 60s are expected.

By Tuesday a negatively tilted shortwave trough will rotate out of
the Rockies and move northeast across the Plains. By afternoon
Tuesday surface based CAPE will approach 1000 J/kg in central and
north central Kansas and bulk shear is forecast to increase to 30 to
40 kts across the cwa. Could see some strong storms Tuesday
afternoon and Tuesday evening.

A cold front will stall over the Western High Plains into the
Dakotas Tuesday night and early Wednesday then progressing southeast
into central Kansas Wednesday night as the upper trough progresses
eastward across the Rockies and a lead wave ejects northeast into
the Plains. Shear increases into the 35 to 45 kt range during the
day with around 1200-2000 J/kg of SBCAPE along and ahead of the
frontal boundary. Some of the storms may be strong to severe
Wednesday and Wednesday night. The longwave upper trough moves
eastward across the Plains Thursday with the trough axis moving
through eastern Kansas Thursday night. Shortwave dropping southeast
from the northern Plains may clip northeast Kansas Friday and bring
a chance of showers. High temperatures will cool from the upper 70s
to lower 80s on Wednesday to the upper 60s to lower 70s on Friday.
Lows will cool from the 60s into the lower 50s by the end of the


.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1241 PM CDT SAT SEP 27 2014

All terminals are expected to remain VFR throughout the afternoon
into the early morning hours on Sunday. The shallow fog between
09-14Z Sunday at KTOP and KFOE will be the challenging time frame.
Confidence is higher though due to no major airmass change and
favorable conditions setting up similar to the previous day. The
small possibility of showers could also begin to affect KMHK
between 1200Z and the end of the TAF period but have been left out
for now due to lower confidence.




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