Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 191152

Area Forecast Discussion
National Weather Service Topeka KS
552 AM CST Thu Jan 19 2017

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 259 AM CST Thu Jan 19 2017

Satellite water vapor loop shows the upper low centered over western
Kansas at 08Z with energy rotating around the low. Latest surface
analysis shows 40 degree dew points generally along Interstate 70
and south at 08Z. 88D VAD winds show a southwest to south flow at
850mb with 925mb winds about the same. Moisture will continue to
push northward this morning as winds become more southerly with the
approach of the low moving eastward. Short term high resolution
models have been overdoing the light precipitation early this
morning as regional radars show precipitation is further to the east
and expect this trend for a few more hours. Stratus will likely keep
dense fog at bay this morning, but anticipate some advection fog
across the area. Later this morning and afternoon expect some
drizzle across north central and parts of northeast Kansas to
develop and have expanded a little further east of Manhattan. Despite
the clouds temperatures should warm into the mid 40s to lower 50s.
This evening the upper low will move across northeast Kansas with
the upper trough axis moving out of the area shortly after 06Z.
Expect to see some drizzle or very light rain across the area when
lift increases this evening. Clouds will remain through the night
while chances for drizzle decrease after midnight with the loss of
lift in the lower saturated layer. Do expect some light fog as well
with an extensive area of low clouds. Lows tonight should range from
the mid 30s far north central to the lower 40s across east central

.LONG TERM...(Friday through Wednesday)
Issued at 259 AM CST Thu Jan 19 2017

By Friday, one mid-level shortwave trough will be lifting north of
the area with a second mid-level shortwave expected to swing over
the area by Friday night.  This second approaching wave will help to
lift an area of low pressure and associated warm front northward
across the CWA Friday afternoon into Friday evening. Model soundings
continue to show shallow moisture and lift present in the low-levels
ahead of the advancing warm front. As a result, have the mention of
drizzle through the day and AM fog for much of the northern half of
the CWA.  With the warm front lifting northward across the area
through in the afternoon, winds will shift to the south over east
central KS early enough in the afternoon to likely boost
temperatures into the mid/upper 50s with highs only into the upper
40s/low 50s across north central to far northeast KS.  As this
second wave lifts northeastward toward the Great Lakes region,
conditions will dry out late Friday night through Saturday with
unseasonably mild temperatures persisting as highs rise into the low
to upper 50s.

Models continue to show a mid-level trough over the southwestern
U.S. at the start of the weekend tracking eastward into Texas and
Arkansas and eventually becoming a closed-off low. However, latest
model guidance is in decent agreement with tracking this low a bit
further south compared to previous model runs. As a result, the wrap-
around precipitation will likely remain just south and east of the
CWA through the day on Sunday, resulting in dry conditions across
the CWA for the latter part of the weekend.  Slightly cooler
temperatures are expected Sunday into Monday with highs in the 40s
as a weak mid-level ridge and surface high pressure advance into the
central U.S. behind the exiting southern system.

The next chance for precipitation may be from another mid-level
trough that models show pivoting into the central U.S. on
Tuesday/Tuesday night. There is still model uncertainty in the
coverage of any precipitation that develops from this system.  While
temperatures will remain near or slightly above the seasonal normals
with highs in the 40s, overnight low temperatures are expected to
drop below freezing. As a result, any evening precipitation Tuesday
night into Wednesday morning would result in rain transitioning over
to snow.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 538 AM CST Thu Jan 19 2017

LIFR cigs will continue through the late morning hours at the
Topeka terminals, while MHK cigs will build to LIFR within the
next 1-2 hours. A brief improvement to IFR (possibly MVFR) during
the afternoon hours. As cloud depths increase this afternoon and
evening, light drizzle is expected to develop. Cigs will begin to
lower once again to IFR and LIFR after sunset this evening,
continuing through the end of the period.




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