Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 181731

National Weather Service Topeka KS
1231 PM CDT Tue Oct 18 2016

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 221 AM CDT Tue Oct 18 2016

07Z water vapor imagery shows broad cyclonic flow over the CONUS
with one shortwave lifting through MN and a second shortwave moving
onshore over the Pacific Northwest. Meanwhile at the surface a cold
front continues to push south into the southern plains. 06Z surface
obs show the boundary from near Nebraska City to just west of
Manhattan and onto the Wichita area. The 00Z TOP RAOB shows a fairly
dry airmass was in place ahead of the boundary and a big reason for
the dry frontal passage.

The forecast for today and tonight has dry weather continuing.
Models do not show much if any synoptic scale forcing which makes
sense with no obvious wave upstream on the water vapor imagery. On
top of that the cold front should be all the way through the forecast
area by day break. The one interesting feature in the model
solutions is the development of a weak surface low or inverted
trough over the Ozarks and central OK late tonight. This area of low
pressure tends to cause low level flow to veer more to the east and
southeast with the potential for some moisture to advect back north
over the surface ridge. In general models tend to keep this area of
theta-e advection mainly south of the forecast area so precip
chances appear to be very small for east central KS.

The cold air advection from this initial front appears to be short
lived as the high pressure system gradually weakens through the day
today. Therefore with decent insolation highs are expected to warm
into the lower and middle 70s this afternoon which is in line with
mixing down temps from around 875MB. With low level flow veering
tonight, the cold air advection should be over with models
indicating neutral advection. However mostly clear skies and
relatively dry air should allow for some radiational cooling and
lows to fall to around 50.

.LONG TERM...(Wednesday through Monday)
Issued at 221 AM CDT Tue Oct 18 2016

By Wednesday, a broad upper level trough will be moving over the
central United States.  This trough deepens and moves east over
northeast Kansas throughout the afternoon and evening, bringing a
small chance for precipitation Wednesday night.  From here, no
sensible weather is expected through the end of the period.  Surface
high pressure moves in Thursday keeping conditions dry and much
cooler with highs only expected to reach into the lower 60s.  This
high pressure slides off southeast by Friday, allowing a stronger
pressure gradient Friday afternoon leading to some gustier winds.
Upper level ridging moving in from the southwest dominates through
Monday keeping any active weather out of northeast Kansas.  Highs
and lows trend towards more seasonal values after Thursday with
highs in the upper 60s and low 70s, and lows generally in the 40s.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1231 PM CDT Tue Oct 18 2016

VFR conditions anticipated. A dry airmass building in and enough
north to northeast winds off the surface should prevent any
diurnal BR development. Could see stratus late in the forecast but
it should be well above limiting levels.




SHORT TERM...Wolters
LONG TERM...Heller
AVIATION...65 is the U.S. government's official web portal to all federal, state and local government web resources and services.