Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 141610
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1010 AM CST Sat Jan 14 2017
Quiet conditions are expected for today into tonight with surface
high pressure in control. Mid to high clouds blanketing the area
this morning should thin this afternoon and evening as drying
The clouds will thicken again by Sunday morning, as mid and high
level moisture returns ahead of the next weather system to impact
our area early next week. This system is still expected to bring a
mix of precipitation types, including light freezing rain, to
southern Wisconsin on Monday.
High temperatures will be a bit milder for today and Sunday,
topping out in the 20s to lower 30s. Lows tonight will range from
the single digits in our northern areas, to around 15 in the
Watching a band of mixed MVFR/IFR clouds to our west and
northwest this morning. As this band slides southeast, we could
see areas of lower ceilings for a time before the low clouds mix
out by late morning. Otherwise, primarily a VFR forecast for this
afternoon into tonight. High level overcast should become
scattered this afternoon before thickening once again late
Light winds will continue through the rest of the weekend as slow
moving high pressure affects Lake Michigan and the Great Lakes. Tug
leaving Milwaukee Harbor reporting NW winds at 5 knots at 9 am. The
light winds and cold temperatures should result in slow ice growth
in shallower areas closer to shore. Warmer air expected to surge
across southern Lake Michigan early next week with increasing winds
should should thin whatever ice develops this weekend.
Winds should gradually increase Sunday night into Monday night, as
low pressure moves toward the area from the southwest.
South winds and waves may reach small craft advisory levels Monday
evening as the low pressure approaches Lake Michigan.
.PREV DISCUSSION... /Issued 240 AM CST Sat Jan 14 2017/
TODAY AND TONIGHT...Forecast confidence is High.
Expect quiet conditions today with surface high pressure in control.
Mostly cloudy skies should linger into morning, with clearing
arriving from the north during the afternoon as mid levels dry.
Upper levels clouds will continue, especially near the Illinois
border. Main issue will be some lingering moisture in the low
levels, especially near Lake Michigan that also extends into
portions of south central Wisconsin. This will gradually mix out.
SUNDAY - Confidence...High
Mid level flow proggd to be broadly anticyclonic with elongated vort
axis strung out across northern WI. Surface/850 millibar ridging
will keep things dry. Best 700 RH remains off to our south. Hints of
some weak 925/850 waa with 925 temps moderating to near 0c.
SUNDAY NIGHT AND MONDAY - Confidence...Low to Medium
The influence of the dry air and ridging gives way to increasing
moisture advection with southerly flow associated with an
eastward translation of LLJ in the central plains. The 12z ECMWF was
more aggressive with bringing QPF into srn WI while the 00z GFS and
GEM show just a nudge into the far sw CWA late in the night. Precip
will continue to expand across srn WI Monday morning with the low
level moisture transport. It still looks like sfc temps will be
tricky for precip type this period with Bufkit soundings showing the
warm layer with support for a mix of fzra/sleet and a brief period
of light snow at the outset. Later Monday morning the low level temp
field is proggd to modify with a northward shift in the mixed precip
with rain becoming more prevalent in the srn cwa. 850 temps will be
on the rise well into the single digits celsius during the
afternoon. A Winter Weather Advisory would be the likely scenario to
handle the freezing rain/sleet/light snow potential for Monday
MONDAY NIGHT AND TUESDAY - Confidence...Medium
Mid level shortwave trough lifts northeast with a surface/850 low
heading towards the area. This will enhance the rainfall across the
area. Went with some hefty pops. Surface low pulls way on Tuesday
though secondary mid level shortwave will be on the way with low
level troughing lingering. Weak caa on Tuesday though soundings/BL
temps suggest precip likely to retain the liquid form. However the
GFS shows an intrusion of colder temps than the other models which
could result in some snow mixing in later Tuesday into Tuesday
WEDNESDAY THROUGH THURSDAY NIGHT - Confidence...Medium
Overall quiet period with a warming trend. Mid level ridging takes
hold with little in the way of forcing to include any pops at this
FRIDAY - Confidence...Low to Medium
Warming trend continues although model disparity with respect to
timing of next system arriving. The GFS is most aggressive in
bringing a low with a surge of rain on Friday. Meanwhile the Euro
and GEM keep things dry. Will stick with the Superblend which does
include some chancy pops accounting for the more progressive GFS.
AVIATION/12Z TAFS/...Main issue will be clouds and ceilings near
Lake Michigan and even into portions of south central Wisconsin
with lingering low level moisture. Light northeast winds in the
low levels have allowed for a few areas of MVFR ceilings in the
1500 to 2000 foot range especially near lake Michigan. However the
moisture and clouds are shallow so scattered to broken areas of
MVFR could linger into early afternoon. This will gradually mix
out. Meanwhile mid levels dry. Upper levels clouds will continue,
especially near the Illinois border.
Weak surface high will result in Light winds.
MARINE...Winds will be generally light into tonight with a weak
surface high across the area.
Winds should then gradually increase Sunday night into Monday night,
as low pressure moves toward the area from the southwest. Winds
may approach Small Craft Advisory levels Tuesday into Wednesday,
as a tighter pressure gradient develops with offshore winds.
TODAY/TONIGHT AND AVIATION/MARINE...Hentz
Sunday THROUGH Friday...Collar