Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 121527
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
927 AM CST Fri Jan 12 2018

.UPDATE...

The remaining lower cloud deck is slowing eroding, so mostly
sunny for the afternoon still looks ok. Temps won`t move much this
afternoon. We might gain a few degrees from our mid morning
readings, but that`s it.

&&

.MARINE...
Strong northerly winds into Saturday afternoon. A few gale gusts
possible. Large waves and some freezing spray expected.

&&

.PREV DISCUSSION... (Issued 539 AM CST Fri Jan 12 2018)

UPDATE...Freezing drizzle has ended across far southeast WI about
1-2 hours ago, however effects remain. Untreated road and walks
across eastern CWA may be slippery from overnight -zl. Issued SPS
to highlight slippery threat. Passing mid-level trof setting off
scattered flurries and a few light snow showers. Expect the
flurries to taper off through mid to late morning with gradual
clearing later in the day.

Low level flow remains mostly north later this morning and
afternoon, however latest RAP soundings hang onto low level
moisture closer to the lake. There is a slight NNE component abv
3K feet, but much drier at this level versus closer to the
surface. Hence wl continue decreasing cloud trend closer to the
lake later today.

AVIATION(12Z TAFS)...Expect scattered flurries to diminish this
morning with gradual clearing. MVFR ceilings will give way to VFR
conditions most areas. However as referenced above, some
uncertainty regards to possible MVFR ceilings lingering or
returning for a time closer to the lake. Low level flow becomes
NNW tonight so widespread VFR expected.

PREV DISCUSSION... (Issued 322 AM CST Fri Jan 12 2018)

SHORT TERM...

TODAY and TONIGHT - Confidence...Medium to High.

Patchy -zl accompanied passage of low level trof over eastern CWA
overnight. Trof will be exiting far southeast in next several
hours so -zl should end. Scattered flurries however will continue
into the early morning as low level cold air advection and
lingering rh along with lingering mid-level trof affect the area.
Expect both low and high clouds over the area to thin through the
morning with mostly clear skies settling in most areas for the
afternoon. Breezy northwest to north winds and low level cold air
continuing to strengthen so not expected much temperature rebound
once the sunshine returns.

A few high clouds may scrap the southern areas for a time
tonight, however mostly clear skies should allow overnight temps
to fall into the -5 to 5 degree range. Lingering northwest breezes
will result in late night wind chills falling to 10 to 20 below
zero.

LONG TERM...

Saturday...Forecast confidence is high:

Mostly sunny skies and below normal temperatures are expected
Saturday under high pressure.

Sunday through Tuesday...Forecast confidence is medium to high:

Models remain in good agreement in bringing low pressure through
early next week. The first shot of snow Sunday afternoon through
Sunday night will be with warm advection ahead of the wave and
then also when the wave and surface low move through. The upper
low will then move overhead on Monday, with the second round of
snow expected as another wave drops through Monday into Monday
night.

Overall, lift looks a little better than with previous model runs
24 and 48 hours ago. Additionally, still seeing a pretty deep
dendritic growth zone in soundings. Given this signature along
with temps and thicknesses, think snow to liquid ratios of 20-30
to 1 seem possible. Ended up with 3 to 5 inches of snow in the
forecast, mainly for Sunday afternoon through Monday night,
though a little snow may linger in the east on Tuesday. Given
this is a longer duration event and it will be a little breezy at
times, settling and compaction may result in somewhat lower
amounts on the ground by the time the snow wraps up. Have highest
amounts in the northeast, where it looks like the snow will fall
the longest due to the pivoting of the system.

Below normal temperatures will continue through early next week.

Wednesday and Thursday...Forecast confidence is medium:

Dry weather is expected to return for Wednesday and Thursday as
high pressure passes through the area. Southwest winds on the back
side of the high should bring temps back to around normal
Thursday.

AVIATION (09Z TAFS)...Widespread MVFR stratus and high clouds
across southern WI should thin through the morning with VFR
conditions developing by afternoon and continuing through tonight.
Flurries to continue into the early morning, however patchy -zl over
far southeast CWA should continue to diminish next several hours.
Breezy northwest winds will veer to the north today.

MARINE...Northwest winds will veer to the north this morning and
remain gusty.  Frequent gusts to 30 knots are expected with a few
gusts likely reaching 33-35 knots.  However expect these high gusts
to be infrequent enough to hold off on upgrading to Gale Warning at
this point, however will need to be watched closely.  Highest gusts
expected after 12Z into this evening.  Gusty north winds will cause
higher waves to build today.  These higher waves and winds will
cause freezing spray.  The high winds and waves will continue into
Saturday so no changes planned with ongoing Small Craft Advisory.

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Small Craft Advisory until 3 PM CST Saturday for LMZ643>646.

&&

$$

Update...Davis
Today/Tonight and Aviation/Marine...MBK
Saturday THROUGH Thursday...DDV



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