959 
FXUS63 KTOP 111140
AFDTOP

Area Forecast Discussion
National Weather Service Topeka KS
640 AM CDT Thu Oct 11 2018

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 333 AM CDT Thu Oct 11 2018

A weak upper wave in the quick zonal flow was exiting eastern 
Nebraska early this morning though a much stronger trough was over 
the central Rockies. Low cloud, rather thin per 0Z OMA and TOP 
soundings, lingered over eastern portions of Nebraska and Kansas 
through early this morning on the northeast flank of a ridge of high 
pressure, though some areas of clearing were occurring. Temperatures 
and winds under the clear skies continue to support frost potential 
over the next several hours in mainly north central Kansas.

Surface ridge passing on east across the state keeps modest cold 
air advection in place with weak winds and highs similar to those 
of Wednesday. Frontogenesis spreads east across the area tonight 
with a seasonally-strong mid-level baroclinic zone overhead as the 
Rockies wave enters the Plains. Light to moderate rain should 
gradually develop east across the state with instability aloft 
appearing too weak for anything more than isolated convection. 
Increasing cloud cover will help keep lows mainly in the lower 
40s.

.LONG TERM...(Friday through Wednesday)
Issued at 333 AM CDT Thu Oct 11 2018

Models are in agreement with the progression of a mid level trough 
across the Plains on Friday. Mid level frontogenetic forcing moves 
over eastern Kansas Friday morning as potential vorticity increases 
lift over the are yielding widespread rain. Progressive nature of 
the system will bring an end to precipitation in the afternoon 
hours. Lowered high temperatures a little on Friday with expected 
rainfall and lingering cloud cover especially in northeast and east 
central Kansas. 

Models are continuing to trend a little further south on Saturday as 
the remnants of TS Sergio move across the southern Plains. The bulk 
of the precipitation is likely to focus the heaviest precipitation 
to the south of a frontal boundary across the southern Plains. A 
reinforcing shot of cold air arrives Saturday night and Sunday as a 
cold front pushes through as a mid level trough moves across the 
northern and central Plains. A broad area of mid level frontogenetic 
forcing with negative EPV in the 600-500 mb layer will bring a mix 
of rain and snow to the area as thermal profiles suggest. Light snow 
will be possible Sunday night into early Monday across the cwa. Very 
cold temperatures are also expected Sunday night with lows in the 
20s bringing a hard freeze to the area. Rising heights and warm 
advection will moderate temperatures across northeast Kansas back 
into the 50s and 60s.

&&

.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 640 AM CDT Thu Oct 11 2018

VFR conditions should be the rule over this forecast. A band of
MVFR stratus will impact TOP and FOE for a few hours around 14Z,
though the band does appear to be dissipating as it moves 
southeast. MHK could be spared impacts on the west edge of the
band, so only have enough confidence for TEMPO there. -RA should 
be developing from the west late in the forecast and MVFR 
conditions are possible but too little confidence on timing for 
inclusion yet. 

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
Frost Advisory until 9 AM CDT this morning for KSZ008>010-020-
021-034.

&&

$$

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