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000
FXUS63 KTOP 301129
AFDTOP

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
629 AM CDT FRI SEP 30 2016

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 319 AM CDT Fri Sep 30 2016

Main features undergo minor changes today and tonight and bring some
forecast difficulties by late tonight. Upper low over the Ohio
Valley looks to lift a bit north with the low level ridge over the
Missouri Valley weakening somewhat. This should allow for slightly
more cirrus to reach eastern Kansas with time with the airmass
modifying a bit for slightly warmer high temps today. The ridge
weakens enough for winds off the surface to go more easterly this
evening, bringing the potential for the low cloud over eastern
portions of Iowa and Missouri early this morning to make their way
into northeastern Kansas late this evening. Models are in good
agreement with these trajectory trends and bring a decrease in
speeds late in the night. Depending on where the stratus ends up and
how far east and persistent the cirrus will be, at least patchy fog
seems possible for mainly northeastern locations after 08Z.

.LONG TERM...(Saturday through Thursday)
Issued at 319 AM CDT Fri Sep 30 2016

Saturday may see some patchy fog in northeast Kansas especially in
the lower elevations and river valleys. Surface ridge will be over
northeast Kansas Saturday morning with light winds expected and
clear skies. Highs on Saturday will mainly be in the lower to mid
70s across the area. Slightly warmer temperatures are expected on
Sunday with the return of southerly flow and rising heights. The
upper low in the Ohio Valley on Saturday will move off to the
northeast through Monday as an upper level trough move across the
western CONUS with a ridge over the Southern and Central Plains.
This will bring temperatures back into the lower 80s for Monday. By
Tuesday the upper trough will move out into the Plains with main
upper low moving northeast into the Northern Plains. Good
moisture return is forecast along with increasing shear and
instability. Best chances focus on Tuesday night into Wednesday for
thunderstorms. A cold front is forecast to move through central and
eastern Kansas on Wednesday as the upper trough moves across the
Plains. The upper trough axis looks to move through on early
Thursday. Expect precipitation to linger in the east Wednesday night
then dry out behind the front by Thursday morning. Cooler
temperatures in the low to mid 70s and lows in the 40s to lower 50s
Friday morning.

&&

.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 629 AM CDT Fri Sep 30 2016

Shallow ground fog earlier this morning at TOP has dissipated
though can`t completely rule out more development through 13Z. A
more likely persistent fog concern comes late in the forecast as
deeper moisture is advected east into the area before winds
diminish. Went with MVFR mention at this point but could easily
see at least brief conditions below IFR.

&&

.TOP Watches/Warnings/Advisories...
NONE.
&&

$$

SHORT TERM...65
LONG TERM...53
AVIATION...65