Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 261955

National Weather Service Topeka KS
255 PM CDT Wed Oct 26 2016

.SHORT TERM...(This evening through Thursday)
Issued at 255 PM CDT Wed Oct 26 2016

The mid-level trough was progressing east of the area with a mid-
level ridge stretching across the western U.S. As the mid- level
ridge and surface high pressure builds eastward into the central
U.S., cloud cover will continue to scatter out across eastern
Kansas. With clear skies and light winds shifting from north to
southeast overnight, expect decent radiational cooling to support
low temperatures plunging into the mid/upper 40s. Models do not
show much change in the dewpoint temperatures overnight with
moisture pooling at the surface as a result of the rainfall from
earlier this morning. As a result, the combination of low- level
moisture, light winds, and clear skies will likely result in some
patchy fog development overnight into Thursday morning across much
of the forecast area. This fog should dissipate by mid morning as
conditions dry out in the low-levels with increased mixing. With
southerly winds in place through the day, expect more mild
conditions with afternoon high temperatures rising into the
mid/upper 70s from east to west.

.LONG TERM...(Thursday night through Wednesday)
Issued at 255 PM CDT Wed Oct 26 2016

The forecast for Friday through Tuesday looks to remain dry as the
overall pattern favors ridging over the southern plains with
periodic shortwaves passing across the northern plains. Will need
to watch trends for Monday as the GFS and ECMWF bring a well
defined shortwave across NEB and SD. However moisture appears to
be limited across the state and models keep the strongest PVA and
Q vector convergence north of the forecast area. The forecast
keeps a mention of precip chances for Tuesday night and Wednesday.
There is some uncertainty in that the GFS shows a warm air
advection pattern with moisture advecting north through the
period. On the other hand, the ECMWF wants to bring a weak
boundary into the area with a weaker warm air advection signal.
The GFS shows the moisture advection to be on the shallow side
with forecast soundings keeping the moisture capped and the prev
ECMWF did not show the boundary over the forecast area. So
confidence in precip chances is low for Tuesday night and
Wednesday and have just a slight chance for showers and
thunderstorms. GFS forecast soundings would support enough
elevated instability for thunderstorms.

Temps should remain mild through Wednesday as models keep the cold
air bottled up to the north. It looks like the Topeka area will go
through the month of October without a freeze. The last time that
was the case was in the fall of 1998 when Topeka`s first freeze
happened on Nov 11th.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1240 PM CDT Wed Oct 26 2016

Prior stratus that developed in the wake of morning showers has
been exiting the area and subsidence finally taking hold behind
with dry air mixing into the terminals. Still some SCT clouds
around this afternoon. More clearing should take place tonight
with subsidence helping to strengthen the radiational inversion
overnight. Feel medium to high on confidence level that at least
patchy fog will form during the 7-15Z time frame so have gone with
reduced VIS during this time. Most guidance is also on track with
this, but there are some hints VIS could go lower. Have held off
on that idea at least for the time being.




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