Area Forecast Discussion
Issued by NWS Milwaukee/Sullivan, WI
FXUS63 KMKX 050920
Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
320 AM CST Mon Dec 5 2016
.TODAY AND TONIGHT...Forecast confidence - Low to Medium.
Low clouds blanket southern WI and adjoining areas early this
morning and will persist through the morning as high pressure ridge
passes by to the south. Areas of fog will affect western CWA this
morning as boundary layer winds diminish a bit, however enough
mixing and stratus expected to prevent fog from becoming dense for a
Currently thinking low clouds should eventually thin later today as
low level winds back to the south to southwest and additional drying
occurs above 1k feet. Confidence in this happening shaky at this
point as fresh snowcover and lingering low level moisture may aid in
low clouds persisting. Even if low clouds do dissipate later today,
upstream warm air advection ahead northern Plains low pressure will
bring mid-high level clouds across WI today and tonight. Therefore,
wl not be too optimistic with any clearing and warming temps up
Northern Plains northward drifting low pressure will drag occluding
front into western WI late tonight. Weak frontogenetical forcing
along boundary and approaching mid-level trof may generate just
enough lift for a patchy light mix of precipitation across the
western CWA after midnight tonight.
The wave will roll through on Tuesday, dragging a cold front
through the area by the afternoon. Looks quite dry in the mid
levels most places, through soundings keep enough saturation for
some low pops in the north. Any light snow that does fall should
taper off by the afternoon hours behind the front. Highs will be
.WEDNESDAY THOUGH FRIDAY...Forecast Confidence...High
High pressure will slowly move through the region Wed through
Fri. It will likely be mainly dry with below normal temps through
this period under the influence of the high. Not out of the
question to see a few snowflakes as a weak wave rolls through
Thursday, but not enough confidence for pops at this time.
.SATURDAY AND SUNDAY...Forecast Confidence...Medium
Models are in decent agreement in bringing snow chances back to
the area Saturday as a wave moves in behind the departing high.
Snow amounts look generally on the low end at this point...but
certainly a lot of time for details to change.
It looks dry Sunday per the ECMWF and Canadian solutions, though
the GFS does bring a second wave and a little more light snow.
Below normal temps are expected to continue for the weekend.
Widespread stratus and IFR/MVFR cigs across southern WI and
adjoining areas. Stratus field has been partially eroding across
eastern IA but redeveloping farther south toward MO border and
moving northward. Will hold on to stratus and low cigs for much of
the morning and then start to lift cigs and erode stratus later
today. Confidence is low on timing and stratus may actually hang on
for longer due to strong elevated inversion perhaps trapping clouds
and moisture around 1K ft or lower. Mid-high clouds will stream in
above stratus during the morning and persist over parts of the area
into tonight. Small chance for mixed light precipitation across
western area later tonight as frontal boundary approaches.
Lingering tighter pressure gradient in wake of low pressure trof
resulted in gusty west winds over the near shore waters overnight.
Racine Reef reported west gusts of 20-25 knots 06-07Z but have since
subsided to around 15kts. Expect wind gusts to remain below 20
knots as high pressure passes by to the south of Lake Michigan this
morning. Winds will back to the south to southeast this afternoon
and tonight. Second low pressure area moving through the northern
plains tonight will result in increasing low level winds overnight.
Steep low level lapse rates due to lingering warm lake surface
temperatures may allow gusts to reach Small Craft Advisory levels
for a time tonight north of Port Washington, however not enough
confidence at this time to pull trigger on advisory.
TODAY/TONIGHT AND AVIATION/MARINE...MBK
Tuesday THROUGH Sunday...DDV