Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 211633 AAA
Area Forecast Discussion...UPDATED
National Weather Service Milwaukee/Sullivan WI
1133 AM CDT FRI OCT 21 2016
Combination of stratus deck moving southward into eastern portions
of the forecast area, along with diurnal cumulus development
elsewhere across the area, should linger into this afternoon. More
clouds are expected in the northern and eastern counties. These
clouds should gradually become more scattered by later this
afternoon into early this evening.
There should be more low to mid clouds moving southeast into the
area later tonight into Saturday morning, with a 500 mb vorticity
maximum. There is some uncertainty with how extensive these
clouds will be in southern Wisconsin. This will affect how cold it
will get tonight across the area, and the extent of any frost
development. Think there will be at least scattered to broken
clouds, and possibly more, so will continue to evaluate need for a
Frost Advisory in the southeast counties.
In general, our frost/freeze headlines will continue only for
Ozaukee, Waukesha, Milwaukee, Walworth, Racine and Kenosha
Counties. These areas have yet to see conditions supportive of
frost over a wide portion of those areas. The rest of the area has
seen a few nights with near-freezing temperatures and frost, so
will discontinue issuing frost/freeze headlines in those areas.
VFR stratus and stratocumulus should linger this afternoon across
TAF sites. These clouds should become more scattered by later this
afternoon into early this evening. North winds will remain light
to moderate this afternoon, before weakening to light and variable
Another round of scattered to broken clouds should move southeast
through the area later tonight into Saturday morning. These clouds
should remain in VFR category during this time. May see scattered
clouds linger into Saturday afternoon, with winds becoming light
Modest nly winds today will maintain waves around 4 feet south of
Wind Point. The winds and waves will gradually lower through the
afternoon into the evening.
.PREV DISCUSSION... /Issued 314 AM CDT FRI OCT 21 2016/
TODAY AND TONIGHT...Forecast Confidence Is High.
A large Upper level trough axis will reach the eastern Great Lakes
this evening as a ridge pushes into the Northern Plains. Little in
the way of upper level divergence with mainly weak downward 700mb
motion. Weak upward motion begins tonight. Weak 700 mb warm air
advection begins this afternoon, with stronger 8950 mb warm air
Forecast soundings indicate the shallow moisture producing the
stratocumulus deck will thin and begin to scatter out by sunrise.
Therefor expect partly/mostly sunny skies. Then 850/700 mb RH
increases, especially after midnight with the developing warm air
The surface ridge will move across southern Wisconsin early this
evening with weak south winds developing south central Wisconsin
late tonight. Frost potential expected to be greatest over
southeast Wisconsin, where frost is likely, even close to lake
Michigan. Frost advisories will likely to be needed.
Lake showers may brush the far southeast Wisconsin shore areas,
especially near Wind Point and Kenosha early this morning. The HRRR
then shifts the lake band more to the east by mid/late morning.
SATURDAY THROUGH MONDAY...Forecast Confidence...High
High pressure will bring continued mostly sunny to partly cloudy
skies Saturday. Highs temps will warm back up to around or even a
couple degrees above normal as southwest winds develop on the
back side of the high.
Weak low pressure is progged to move through the state on Sunday.
It still looks like the best forcing will remain to the north of
the surface low, so expecting the dry weather to continue. High
pressure will follow the departing low for Monday.
Should see temps several degrees above normal Sunday, falling
back to around normal Monday.
TUESDAY THROUGH THURSDAY...Forecast Confidence...Medium
A stronger low will develop to the southwest on Tuesday, moving
through the area on Wednesday. This system is expected to bring
widespread rainfall to the forecast area Tue and Wed. The biggest
problem with this low is where exactly it will track. The GFS and
Canadian models continue to track it just to the south of the
WI/IL border. This would keep the milder temps and instability
south of the forecast area. The ECMWF is a little farther north
and would suggest a small thunder chance, so left a low end
thunder mention in the forecast.
High temperatures Tue/Wed were lowered a bit more given models
are still looking pretty cool both days, especially if a
persistent rainfall develops. Current forecast is still milder
than the blend of model 2 meter temps, so may need to lower the
temps a bit more, especially if the more southern track of the
Kept some low pops Thursday per the slower ECMWF solution dragging
the upper trough through. The GFS is dry though, moving the system
Mostly VFR cigs expected. Cigs mainly between 4-5 kft in most
places. There is the potential for some MVFR cigs near Lake michigan
until mid morning. Some Lake effect showers may brush the shoreline
areas, especially from Wind Point to Kenosha. Expect clouds
to gradually scatter out.
Surface high pressure will move across southern Wisconsin early this
evening, with mid level clouds increasing from the west late.
Brisk north winds near Small craft advisory condition from North
Point Lighthouse into mid morning due to the pressure gradient from
the low near western Pennsylvania, and high pressure over the mid
and upper Mississippi Valley. Still the potential of 3 to 5 foot
waves until mid morning, so will extend the Small craft advisory til
Waves will remain in the 2 to 4 foot range into the early
afternoon with 10 to 15 knot north winds.
TODAY/TONIGHT AND AVIATION/MARINE...Hentz
Saturday THROUGH Thursday...DDV