Area Forecast Discussion
Issued by NWS Topeka, KS

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FXUS63 KTOP 291724

National Weather Service Topeka KS
1124 AM CST SUN NOV 29 2015

Issued at 1124 AM CST SUN NOV 29 2015

Will update the headlines shortly to reflect the latest trends.
Think that for the rest of the afternoon, precipitation will be
light enough that any additional ice accumulations will be minor.
Therefore will downgrade the warning to an advisory for the
remainder of the afternoon. For tonight and Monday morning, the
GFS continues to be slightly warmer than any other guidance in
lifting the freezing line into Cloud and Washington line. Am
leaning more towards the freezing line holding in closer to
Herrington, Manhattan and Seneca overnight based on the model
consensus. The warm nose over the cold air at the surface is not
quite as pronounced as it has been in recent days. Because of
this, am thinking there could be a narrow swath of ice
accumulations of a quarter inch or more just to the northwest of
the freezing line and am considering an ice storm warning for
these areas. To the east of the freezing line, precipitation
should be all rain. There are still indications from forecast
soundings that there could be a brief period of snow across Cloud,
Republic and Washington counties.


.SHORT TERM...(Today)
Issued at 425 AM CST SUN NOV 29 2015

The storm system of the past several days continues to pester the
forecast area, with cumulative accumulation over several days in
addition to new accumulation now beginning to cause significant
impacts in the form of tree and power line damage.

A persistent band of freezing rain showers and freezing drizzle has
been set up on the northwestern fringe of the mid/upper level
moisture plume for more than 12 hours now, and while rates have not
been impressive, the duration of the event in addition to ice
already accumulated over the past few days has begun to exceed
critical amounts. This band has been focused generally from SW to NE
through from Hutchinson through Manhattan and Falls City. The
northeastern extent of this area had not had as much accumulation
over the past few days, but farther south the cumulative ice
warranted issuance of an ice storm warning with reports of branches
and power lines coming down in Dickinson, Geary, Riley, Morris, and
Wabaunsee counties with potential to further expand. This band of
rain showers is likely to very slowly shift east through the day,
but appears likely to persist at least through noon and probably
into the afternoon hours while periods of drizzle continue over the
remainder of the area.

The biggest forecast question through today will be in the location
of the freezing line. All model guidance forecasts a very gradual
warming from southeast to northwest through the day today with those
showers eventually changing from freezing rain to rain for parts of
the area. This is most likely to consistently turn to rain east of a
line from Council Grove to Holton by noon, but with some potential
to move even farther west. This will obviously have a huge impact on
how much ice accumulates and even a change of 1 degree could make a
big difference. Have run at least the central part of the advisory
and the ice storm warning through 00Z, and expect continued
evaluation of the freezing line location to play a large role in
potential early cancellation and/or extension into this evening.

.LONG TERM...(Tonight through Saturday)
Issued at 425 AM CST SUN NOV 29 2015

By tonight, the closed mid-level low will be centered over Wyoming
with a surface low lifting northward into the area. This advancing
surface low will help to usher additional moisture and lift into the
area to support ongoing light precipitation across much of the
forecast area into Monday.  While confidence is high in the
development of widespread light precipitation, confidence is lower
with regards to the thermal profile and what precipitation types can
be expected through the overnight period.  Surface temperatures
tonight will likely hover within a couple of degrees around the
freezing mark with model variations in how warm the warm nose will
be over the area.  The GFS is the strongest with the warm nose and
the NAM appears to be trending a bit warmer as well, but the ECMWF
weakens the warm nose across the northwestern half of the forecast
area. Considering the depth of the warm nose, precipitation across
much of east central Kansas will likely remain in the form of rain.
Locations further west (from roughly Manhattan to Concordia) may see
periods of freezing rain or a mix of rain/freezing rain. With this
warming trend in the models, soundings are not as supportive of
sleet development but cannot entirely rule out the potential for it
to mix in overnight across far north central Kansas. The uncertainty
in which locations will only receive rain versus a rain/freezing
rain mix leads to uncertainty in potential ice accumulations.  The
best potential for ice accumulations unfortunately may be co-located
with the regions that have already been impacted the most by ice
accumulations over the last two days, with upwards of an additional
0.1-0.2 inches of ice accumulation possible.  Have opted out of
extending any headlines into tonight at this time due to too much
uncertainty in the temperature profile, but if conditions trend
toward a favorable zone of freezing rain, then some sort of headline
may need to be issued.  Surface high pressure will quickly move into
the region Monday into Monday night, helping to push the surface low
northeast of the area by Monday night.  As a result, expect
precipitation to end from southwest to northeast through the day on
Monday.  As this system exits the area, some light snow may develop
across far north central and far northern Kansas on Monday as the
thermal profile cools in those locations.  Any snow accumulations
should be around 1 inch or less in north central Kansas.

A stretch of dry weather is finally expected by Monday night and
should persist through the end of the week as the region remains
under the influence of surface high pressure.  As this surface high
shifts east of the area, expect a gradual warming trend with
temperatures with highs in the mid 30s to mid 40s on Tuesday and
warming into the mid 40s to mid 50s by Friday.


.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1124 AM CST SUN NOV 29 2015

IFR continues will prevail through the period. Think temps will
remain just above freezing at TOP and FOE with MHK potentially
hovering a degree on either side of freezing. Stronger forcing
overnight is expected to lead to widespread precip and LIFR CIGS
with the heavier precip.


.TOP Watches/Warnings/Advisories...
Winter Weather Advisory until 6 PM CST this evening for

Winter Weather Advisory until noon CST today for KSZ012-024-026-

Ice Storm Warning until 6 PM CST this evening for KSZ022-023-



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