Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KTOP 181729

1229 PM CDT Sat Oct 18 2014

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 318 AM CDT SAT OCT 18 2014

Water vapor showing final shortwave trough on the backside of Great
Lakes trough now moving southeast across the mid MO valley area with
drier air aloft and subsidence in its wake. This will help to
restrict any northward push of the high cirrus clouds to the south
of the county warning area through the day. In the low levels...cold
air advection will be on the decline as the colder air aloft focuses
further east and stratocu deck to the north should remain well to
the north and east of the cwa. However...the surface ridge to the
north will translate eastward and allow for lighter northerly winds
early today to veer more easterly in the afternoon. With the cooler
start to the day and weaker mixing...high temperatures will be
limited to the low to middle 60s.

For the flow aloft trends slightly more zonal...high
clouds will slowly start to increase from southwest to northeast
later in the night...but mostly clear skies should be the rule.
Light southeast winds will veer more southerly late. This should
limit lows to generally the low to middle 40s.

.LONG TERM...(Sunday through Friday)
Issued at 318 AM CDT SAT OCT 18 2014

Sunday Night, the longer wave length trough across the eastern US
will amplify as a shorter wave length trough across south central
Canada digs southeast across the upper mid west and into the mid MS
river valley. As a 60 KT H5 jet max digs southward across MO there
may be enough lift along with residual moisture for a few showers
across southeast KS. The northern fringe may of these showers may clip
the southeast counties of the CWA during the night. The only model
with QPF as far north as Coffey and Anderson counties is the ECMWF.
Both the NAM and GFS keep QPF south and southeast of the CWA. At
this time I went with 14 pops across the southeast counties in case
some isolated showers may develop ahead of the surface cold front.

Monday through Wednesday, the longer wave length trough across the
eastern conus will gradually shift east and slowly become more of a
closed upper low across the mid Atlantic states. An upper level
ridge across the western US will move east across the plains. The
coldest airmass will remain well northeast of the CWA. Highs will
reach the upper 60s to lower 70s, with some areas reaching the mid
70s on Monday. Overnight lows will generally be in the mid to upper

Wednesday night through Thursday, an upper level trough across the
northern high plains will shear apart. The southern section of the
upper trough will dig southward across the high plains into far
western TX by Thursday afternoon. As the H5 trough digs southward
across the high plains scattered showers and thunderstorms will
develop along a weak surface cold front across western KS and
eastern NE. This front will remain nearly stationary with the best
chances for rain occurring across southwest KS northeast into north
central KS. As the H5 trough digs farther south into far west TX
the stronger ascent will shift south of KS into OK. The showers
and isolated thunderstorms along and west of the surface cold
front will diminish during the late afternoon hours of Thursday.
Cloud cover and perhaps scattered showers and isolated
thunderstorms will keep highs a bit cooler in the mid 60s to
around 70 degrees.

Thursday night through Friday. The H5 trough will transition into a
closed off upper low across far southwest TX. A weak cold front will
pass southeast across the CWA Thursday evening. An upper level ridge
over the western US will build eastward across KS and to the north
of the upper low over southwest TX. Expect mostly sunny skies with
highs in the lower to mid 70s.


.AVIATION...(For the 18Z TAFs through 18Z Sunday Afternoon)
Issued at 1204 PM CDT SAT OCT 18 2014

MVFR stratus has halted advance into northeast KS and is now
mixing out around the edges. Do not expect more than SCT clouds
at TAF sites this afternoon. Otherwise, light winds and gradual
wind shift to the east then south this evening and overnight.




LONG TERM...Gargan
AVIATION...GDP is the U.S. government's official web portal to all federal, state and local government web resources and services.