Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 270530

National Weather Service Topeka KS
1130 PM CST THU NOV 26 2015

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Friday)
Issued at 321 PM CST THU NOV 26 2015

Cold front has swept through the area earlier this morning as high
pressure builds into the central plains. Southwest flow aloft has
allowed warm temperatures and moisture to persist over this surface
frontal boundary. An area of light to moderate rain has developed
along and behind the front where lift has been maximized. Sub
freezing air located to the north and west has finally pushed into
north central KS. This is where a change over to freezing rain is
possible through the afternoon. The freezing line is forecast to
gradually move southeastward through the evening and overnight.
There seems to be a break in the precip or more showery activity,
but the regional radar has begun to fill in across the panhandles
and southwest KS. This area of precip is forecast to move
northeastward into this sub freezing air where icing is expected. At
first the roads might not be cold enough for accumulation, but
overtime the roads will likely start to freeze. Of course the
bridges and overpasses will freeze over first.

The best time for freezing rain appears to be later this evening and
overnight. Overnight the models agree on a decent amount of qpf
amounting to about 0.2 to 0.3" of ice accumulation. This may be
enough to cause isolated power outages especially given the possible
wind gusts. The roads will likely become hazardous shortly after the
freezing temperatures arrive. There may be a lull in the precip
after midnight before yet another round of lift moves in from the
southwest tomorrow morning. Forecast soundings are indicating the
cold air may be slightly deeper than anticipated. This may cause
more sleet to mix with freezing rain regardless of the warm nose
aloft. By sunrise the freezing line will be somewhere near Emporia
to Topeka, and continues across most areas by mid day Friday. The
models are indicating that the precip stays confined to areas along
and south of I-70. Light icing could be possible in these areas if
freezing rain remains the predominate precip type. Although as we
move into tomorrow cooler temps aloft and in the lower levels
introduce the potential for more of a mix of snow and sleet mix.
Amounts in this case would amount to very little, but could cause
road issues.

.LONG TERM...(Friday Night through Thursday)
Issued at 321 PM CST THU NOV 26 2015

The weekend periods` forecast continues to bring uncertainty in
specifics but at least some potential for additional periodic
wintry precipitation. Southwest upper flow continues to keep at
least some moisture content in the atmosphere with the upper low
making slow progress into the Plains early next week. Depth and
quality of the moisture is still hard to narrow down, with most
guidance showing at least some periods where depth up into the ice
crystal zone will be difficult to come by. Forcing for strong ascent
is also not readily apparent, though fairly steady but weak
isentropic upglide is present for many periods behind the old
high. At this point the greater chances for more widespread
precipitation look to come Sunday night into Monday as a shortwave
rotates around the ejecting low, but the still rather moist low
layers and persistent though modest ascent keep at least small
chance for precip Friday night through Sunday. Could easily see
drizzle or freezing drizzle dominate precip types most of these
periods, but the inclusion of freezing rain gets the message
across of potential problems without an excessively complicated

Remainder of the forecast continues to look benign. Pacific high
pressure builds in from the west for near normal temps.


.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1130 PM CST THU NOV 26 2015

The main band of showers is currently moving east of the area
allowing TAF sites a brief clearing of the precip before
redevelopment early morning.  Introduce PL at MHK at 12Z tomorrow,
with TOP/FOE seeing a mix of FZRA/PL.  With this precip, expect IFR
ceilings to hold on through the period.  Some models show TOP/FOE
eventually changing over to all PL tomorrow, but with low confidence
on this exact timing will need to continue to monitor trends.


.TOP Watches/Warnings/Advisories...
Winter Storm Warning until 6 PM CST Friday for KSZ010>012-

Freezing Rain Advisory until 6 PM CST Friday for KSZ026-039-040-

Winter Weather Advisory until 6 AM CST Friday for KSZ008-009-020-



SHORT TERM...Sanders
AVIATION...Heller is the U.S. government's official web portal to all federal, state and local government web resources and services.