Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI

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FXUS63 KMKX 160533

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1133 PM CST Wed Nov 15 2017

.UPDATE...Thin spots continue to increase and have shifted south
into southern Wisconsin and also linger in the northeast. Appears
stratus is turning more cellular in nature, but large shield
remains over northern and central WI. Still think this may shift
southward for a time into southern WI during the late night before
more widespread clearing develops Thursday morning.


.AVIATION(06Z TAFS)...Varying ceilings between MVFR and VFR
expected through the late night as stratus beginning to thin and
break up in spots. Gusty northwest winds will slowly diminish
through mid-morning Thursday.


.PREV DISCUSSION... (Issued 953 PM CST Wed Nov 15 2017)

UPDATE...Widespread stratus beginning to thin in parts of far
western Wisconsin as well parts of the northeast and east
central. This trend may continue as cold air advection begins to
wane and short wave ridging begins to spread in from the west.
Blustery WNW winds of 15 to 25 knots with gusts as high as 30
knots will continue next few hours before diminishing. Overnight
temperatures look in good shape.

MARINE...Few gusts reaching Gale Warning levels off shore. Racine
Reef observation reported gust to 35 knots around 03z. Few more
gale gusts are possible through the late night but mostly wind
gusts are expected to remain at or below 33 knots. May yet upgrade
to Gale Warning in next few hours. Otherwise, Small Craft Advisory
remains in effect through Thursday morning due to gusty WNW winds.

PREV DISCUSSION... (Issued 544 PM CST Wed Nov 15 2017)

UPDATE...Low clouds will linger for much of the night. Increasing
subsidence and low level drying should result in partial clearing
Thursday morning with mid-high clouds already expected to stream
into the area Thursday afternoon and evening. Strong, gusty
northwest winds will continue this evening, then slowly diminish.
Surge of colder air will result in temperatures falling into the
low to mid 30s during the evening.

AVIATION(00Z TAFS)...MVFR ceilings should overspread far
southeast Wisconsin in the next hour or two. Low level cold air
advection behind cold front will result in low clouds over
southern WI for much of the night. Low clouds may linger into
Thursday morning before clearing. Gusty northwest winds will
continue overnight but slowly diminish.

PREV DISCUSSION... (Issued 227 PM CST Wed Nov 15 2017)


Rest of this afternoon into Thursday - Confidence...Medium to
High Cold advection stratus wrapping southeast into srn WI
overtaking any brief clearing due to dry slot. Lingering rain
shifts out by mid/late afternoon. Low level RH progs show that
this cloud cover should hang around into late tonight or early
Thursday. Surface pressure gradient remains tight into Thursday
morning then high pressure builds in from the west for the
afternoon easing the wind field.

Friday Through Sunday...Forecast Confidence Is Medium...

A strong trough moves across the northern plains and becomes
more negatively tilted as it moves east of Wisconsin by Saturday.
The GFS and Canadian have continued the trend toward the slower
and slightly weaker trough.

A surface low will intensify, especially just east of the lake
Huron area Saturday. Models are more in line, but the ECMWF and
now the canadian is a still a little more south in the

Warm air advection develops Thursday night and begins to bring
more moisture into the region. The models are still dry Thursday
night, with light rain spreading in friday, especially afternoon.
By the time this occurs, precipitation type should be rain. There
is some elevated CAPE around 150 Joules/kg on the GFS Friday

It will be windy, both ahead of, and especially behind the low,
any wind advisories are unlikely.

Possibility of snow accumulations in our area is low, as by the
time the cold air moves in behind the low, the precipitation is

By Sunday afternoon a surface ridge will be moving across
Wisconsin, diminishing the winds.


Monday Through Wednesday...Forecast Confidence Is Medium...

A somewhat cyclonic northwest flow Sunday night becomes more
zonal Monday across southern Wisconsin. The ECMWF has a quicker
and stronger shortwave in the northern stream over south central
Wisconsin that drops into the Great Lakes region Tuesday. The GFS
is much weaker with this feature, with the canadian more of a

A south flow begins sunday night and Monday, with a surface low
moving north of the lake Superior region Monday night. This then
brings some cold air advection into southern Wisconsin, quicker
and stronger on the ECMWF Tuesday.

With the track of the low so far north, little precipitation is


A cold front continues to shift to the east
of WI with still some lingering rain across the northeast cwa.
Lighter showers in the southeast. A window of breaks in the
overcast noted between dry slot and incoming cold advection
stratus from the northwest. Should see more breaks in the clouds
for Thursday as a ridge of high pressure edges closer and scours
out some of the low level RH/MVFR cloud deck.


Small Craft Advisory in good shape. Wind shift has
occurred with passage of cold front. WNW winds will be gusty with
the higher waves shifting more towards the open waters due to the
offshore component.


LM...Small Craft Advisory until noon CST Thursday for LMZ643>646.



Tonight/Thursday and Aviation/Marine...Collar
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