253
FXUS63 KTOP 171157
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
657 AM CDT Tue Oct 17 2017

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 259 AM CDT Tue Oct 17 2017

Currently, few to scattered mid to high clouds continue to
traverse over northeastern KS associated with a very minor low
amplitude wave within the broader northwest flow pattern in place.
Quiet weather remains with a dry atmosphere and continental type
airmass in place. Light southerly winds are helping to keep
overnight temps warmer than last night and only expected to bottom
out in the mid 40s.

Northwest flow regime will hold for the next 24-30 hrs with perhaps
another low amplitude wave bringing mid to high clouds once again
over the area. Weak forcing with this wave won`t allow for much
cloud coverage once again.  Certainly, no precip will be seen with
an overall very dry and stable atmosphere in place.  Looking for
warmer 900-850mb temps to support warmer high temps today into the
middle 70s across the area.  A weak LLJ will also be mixed down
helping a few gusts into the late morning and into the afternoon
reach near the 20mph mark. All in all, not a bad fall day in
store.

.LONG TERM...(Wednesday through Monday)
Issued at 259 AM CDT Tue Oct 17 2017

Dry conditions continue through Thursday as the upper flow goes
from zonal, through a shortwave ridge, then becomes southwesterly
into Friday as the next large scale upper trof over the western
US starts to make eastward progress. Highs should be in the 70s
with overnight lows Wednesday night in the 40s, becoming lows in
the 50s Thursday night as warm advection and southerly flow
returns in the boundary layer.

Models differ on whether leading shortwave impulse in the flow
for Friday will be enough to generate any rain over eastern Kansas
and currently just have some low end PoPs for Friday evening.
Differences continue through Saturday with speed and southern
extent of the larger trof, with relative agreement that the axis
is forecast to be east of the state by early Sunday. Enough
instability and shear Saturday afternoon as the trof and front
move through that these storms could be strong, should this
forecast trend continue. Cooler temperatures come in behind the
system with another front pushing southward into Monday, dropping
highs back into the 60s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 644 AM CDT Tue Oct 17 2017

For the 12Z TAFs, have kept WS mention through 13Z at all sites as
a weak LLJ remains in place. Will begin to mix after sunrise and
expect winds to begin to increase at the surface as a result.
Could see gusts around 20kts mid morning into the afternoon. Some
potential for WS again tonight, but LLJ may be somewhat less
pronounced so have left mention out of forecast for now.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...Drake
LONG TERM...67
AVIATION...Drake