000
FXUS63 KTOP 232320
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
520 PM CST Fri Jan 23 2015

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Saturday)
Issued at 258 PM CST FRI JAN 23 2015

A weak upper level trough across the upper Midwest will dig
southeast into the mid MS river valley and phase with a more intense
southern stream upper trough moving east out of TX. The resulting
amplified upper trough across the east central conus will keep the
plains in northwesterly flow aloft.

This evening, as the weak positive tilt upper trough axis shifts
southeast across the eastern plains, the stronger ascent will cause
a period of mid-level clouds to develop. As the H5 trough axis
shifts southeast of the area skies will clear through the early
morning hours. Overnight lows will only drop into the mid to upper
20s as west-northwest winds will remain around 5 MPH.

Saturday, an upper level trough over western Canada will dig
southeast into the the northern high plains. Ahead of the the upper
trough, southwesterly surface winds will allow highs to warm into
the mid 50s to around 60 degrees. Even though 850mb temperatures
will warm to around 6 degrees, the mixed boundary layer will only
reach about 930mb. Dry fuels and southwesterly winds of 10 to 20 MPH
with some higher gusts will cause at least a high fire danger across
the CWA Saturday afternoon.

.LONG TERM...(Saturday Night through Friday)
Issued at 258 PM CST FRI JAN 23 2015

The extended period of the forecast will be noted by a continuation
of mild temperatures and predominantly dry conditions.  By Saturday
night, a broad mid-level trough will be situated over the central
and eastern U.S. with a mid-level ridge along the Pacific coastline.
Models show an embedded shortwave trough developing over the
Northern Plains Saturday night and sliding southeastward across the
Midwest through Sunday. The better moisture and lift from this wave
should be focused northeast of the forecast area. However, both the
GFS and ECMWF show the potential for some light precipitation to
skim across northeast Kansas, with model soundings showing
increasing saturation in the mid-levels with dry conditions in the
low-levels. As a result, the mention of sprinkles has been added for
Saturday evening before the wave shifts east of the area.  A decent
pressure gradient is expected to set up over the area on Sunday as
the associated surface low passes just to the east, resulting in
breezy northwesterly winds with gusts upwards of 25-35mph. There
doesn`t look to be much in the way of caa behind this wave, so
temperatures should only be a few degrees cooler on Sunday with
highs in the low/mid 50s.

The region will remain under northwesterly flow aloft through
Tuesday as the mid-level trough remains anchored over the eastern
U.S. and the mid-level ridge slides eastward toward the Rockies and
the High Plains. Trended warmer for Monday with highs in the upper
50s/low 60s as a thermal ridge should develop over the Rockies and
High Plains. Slightly cooler conditions expected for Tuesday as
surface high pressure advances into the area.

By mid-week, models show a wave originating near the Baja peninsula
and tracking northeastward, however models continue to keep the wave
and any associated precipitation north of the forecast area. If this
wave were to track a bit further south, then there may be a slight
chance for some light precipitation, however have kept a dry
forecast for now.  This advancing wave will push an area of surface
low pressure into the Northern and Central Plains by Wednesday,
resulting in southwesterly winds and temperatures rising back into
the 60s.  The weak cold front associated with this system will track
south of the area by Thursday morning. While this frontal passage looks to
be dry across the area, it will be accompanied by cooler air in
which cold-air advection will likely bump high temperatures back
down into the 40s for Thursday and Friday. Models are showing split
flow by the end of the week/early next weekend in which 2 waves may
converge near the forecast area and potentially bring some light
precipitation.

&&

.AVIATION...(For the 00Z TAFs through 00Z Saturday Evening)
Issued at 519 PM CST FRI JAN 23 2015

VFR conditions expected through the period. Wind shifts from west
to northwest then back again with clouds aoa 10kft. May see a few
sprinkles tonight but not enough worth a prevailing group.

&&

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

$$

SHORT TERM...Gargan
LONG TERM...Hennecke
AVIATION...67