Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 151811 AAB

Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
1211 PM CST Mon Jan 15 2018


We downgraded the winter storm warning to a winter weather
advisory for the southeast counties (Milwaukee, Racine, and
Kenosha). That intense lake effect snowband over Sheboygan will
accelerate as it moves south of Port Washington late this
afternoon into the evening which will limit the additional
snowfall amounts. In addition, that band will be moving through
the metro area after rush hour now.



SBM: The heavy lake effect snowband is the main concern for this
afternoon/evening. It is currently over Sheboygan and will take on
a more west to east orientation through mid afternoon, pivoting
over Sheboygan county. Expect very low visibility within this
band, along with rapidly accumulating snow with rates of 1 to 2 inches
per hour directly under the band. This band will start to slide
south late this afternoon and then accelerate through this
evening. Areas outside of Sheboygan and Washington counties are
expected to have a much lower impact from this snow band since it
should be a shorter duration. Look for increasing northerly winds
behind the band.

MSN: Visibility and ceilings are uncertain for Madison early this
afternoon. There is a band of snow just to the west of MSN that
has the lower cigs/vsbys and that band could set up over Madison
for a time. It appears that the overall weakening trend may be

MKE/UES/RAC/ENW: Wind direction is the main uncertainty for this
afternoon. Expect snow to lighten up this afternoon, but winds
should also remain light and generally out of the south for MKE
and UES. Look for winds to shift to the west at ENW and eventually
RAC for a time late this afternoon. The snow band will slide south
through these sites during the evening hours. The timing is now a
little later than previously expected. Expect visibility less than
1 mile and higher snowfall rates (1-2" per hour) for about a 1
hour period of time under the band.


.PREV DISCUSSION... (Issued 912 AM CST Mon Jan 15 2018)


We`ve had 3 to 5 inches over the western 2/3 of the forecast area
so far. The east is generally around 1 to 2 inches with a few 3
inches in there. Our focus through the day is the focused lake
band stretching from off shore of Milwaukee north into Manitowoc
right now. This will be a productive snow maker with visibilities
likely at 1/2 mi or less as it moves in. This band will gradually
turn more east to west in orientation and drift south through the
day, reaching the Milwaukee metro area for the evening rush hour.
This should add an additional 3 or so inches to our totals so far.
This band is mostly lake effect in origination right snow, but it
will become part of the sharp surface trough convergence axis
with time. That will allow for the snow to spread quite a ways
inland this afternoon into the evening. Overall, the forecast
remains on track. See our social media accounts for some of the
latest graphics depicting current and expected snowfall.


The small craft advisory remains in effect north of Port
Washington through today. The southerly winds are bringing high
waves to those area. A small craft advisory may be needed again
for Tuesday as brisk northeast winds bring high waves again. There
is ice in the nearshore waters making any marine activity

PREV DISCUSSION... (Issued 539 AM CST Mon Jan 15 2018)

UPDATE...The forecast is on track for today and Tue.

AVIATION(12Z TAFS)...Light to moderate snow will continue today
and tonight. Cigs of 1-3 kft will prevail. Vsbys will be variable
from 1-5SM depending on the intensity of the snow at the time.
Heavier snow is expected near Lake MI where vsbys of 1/4-1/2SM
could briefly occur.

PREV DISCUSSION... (Issued 358 AM CST Mon Jan 15 2018)


Today and Tonight...Forecast Confidence is Medium.

The n-s sfc trough over sw WI will occlude as the upper low
approaches from MN. More specifically, the sfc trough will pivot
to a w-e sfc trough later today and then shift swd through the
area. The heavier snow will be associated with this feature with a
general light snow for this morning. Lake enhanced snow will
occur especially as the sfc trough shifts south across ern WI
this afternoon and evening. Forecasted snow accums from 12z today
into Tue AM is 3-7 inches for the lake counties with ern Sheboygan
County experiencing the highest amounts. A general 2-4 inches over
the remainder of srn WI with lesser totals sw of Madison. Winter
Wx headlines remain the same.

Tuesday - Confidence...Medium
Mid level trough axis shifts to the east. Low level flow remains
favorable especially in the morning for lake effect potential.
However, mesoscale models are showing at least the heavier
snowfall remaining out over the lake. Will be a close call in our
lake counties. However enough potential still in place to not
change things up too much at this juncture, especially given the
fickle nature of convectively driven snow bands.

Wednesday through Friday - Confidence...Medium
Expecting moderating temperatures this period with little if any
precipitation expected. the only hiccup is the GFS which brings a
slightly stronger trough through Thursday night while the GEM and
ECMWF have much weaker or further north signals on this feature.

Saturday and Sunday - Confidence...Medium
Models show a little isentropic lift getting underway on Saturday
ahead of the next system in the central Plains but for now much of
the day looks dry. At this time the 00z runs of the GFS and ECMWF
are in remarkable agreement on the track of the surface/850 low
through the state Sunday and Sunday night which is a warmer track
for srn WI. The GEM, while faster, also shows the low tracking
well north. However last run of the GFS had a much colder look so
being about a week out, will be interesting to see how this system
continues to evolve over the numerous model runs yet to come.

AVIATION(09Z TAFS)...Light to moderate snow will continue today
and tonight. Cigs of 1-3 kft will prevail. Vsbys will be variable
from 1-5SM depending on the intensity of the snow at the time.
Heavier snow is expected near Lake MI where vsbys of 1/4-1/2SM
could briefly occur.

MARINE...The brisk sly winds will weaken by later morning so the
Small Craft Advisory south of Port Washington will expire at 6 AM.
However, the Small Craft Advisory will continue until 6 PM as high
waves linger through the day. Another Small Craft Advisory may be
needed on Tue due to brisk nly winds and building waves.


WI...Winter Weather Advisory until 6 AM CST Tuesday for WIZ059-065-

     Winter Weather Advisory until midnight CST tonight for WIZ046-

     Winter Storm Warning until noon CST Tuesday for WIZ052-060.

LM...Small Craft Advisory until 6 PM CST this evening for LMZ643.



Today/Tonight and Aviation/Marine...Gehring
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