Scientific Forecaster Discussion
fxus63 kmkx 220245
Area forecast discussion
National Weather Service Milwaukee/Sullivan WI
945 PM CDT Sat Jul 21 2018
Update...the forecast is on track for tonight and Sunday.
Marine...a Small Craft Advisory remains in effect tonight through
Sunday afternoon for breezy nly winds and 3-6 foot waves. The
winds will gradually weaken throughout Sunday with waves falling
below 4 feet by evening.
Beaches...a beach hazards statement remains in effect tonight
through Sunday afternoon for beaches along the Lake Michigan
shoreline. The combination of winds and waves will lead to a
high swim risk during this period, which will cause dangerous
structural, longshore and rip currents. Stay out of the water this
Previous discussion... (issued 641 PM CDT Sat Jul 21 2018)
Update...the large upper low over mi, in, and Ohio will continue
to swing vort lobes and weak sfc troughs into srn WI through
tomorrow. These features will be weaker than prior days with less
rainfall coverage expected later tonight and Sunday.
Aviation(00z tafs)...cigs will mainly range from 600-1900 feet
tnt-sun am, although higher at times west of Madison. The cigs
will then rise to VFR around 3.5 kft during Sunday afternoon.
Previous discussion... (issued 353 PM CDT Sat Jul 21 2018)
Tonight and Sunday...forecast confidence is medium.
Showers should continue to develop and/or slide southward through
the area into early this evening. They may linger for a time later
this evening and perhaps overnight, especially in eastern portions
of the area, closer to the 500 mb low center. Kept isolated
thunder wording into early evening, with meager mean layer cape.
Clouds will linger tonight into Sunday morning, with low ceilings
overnight into Sunday morning. Lows in the middle 60s are
Kept lower end chances for showers going on Sunday, as the area
remains in the 500 mb cyclonic flow aloft, and brings several
vorticity maxima through the area. Enough low level moisture
remains to support the shower chances as well. Should see gradual
scattering out of clouds in the afternoon from north to south.
Highs in the upper 70s look reasonable inland, a little cooler
Lakeside with onshore winds.
Sunday night into Tuesday...forecast confidence is high.
Models are showing a weak cold front moving southeast through the
region Monday and exiting on Tuesday. Not much upward vertical
motion or moisture to speak of with this feature, so kept the dry
forecast. Highs should rise back into the 80s early next week,
with gradually increasing dewpoints.
Tuesday night into Saturday...forecast confidence is medium.
Models are showing a stronger cold front moving southeast through
the region later Wednesday into Wednesday night. This may have
enough moisture and upward vertical motion to bring some chances
for showers and storms. Models are more unsettled later in the
week, with differences with the handling of another system during
this time. For now, kept small pops going with seasonable
Aviation(21z taf updates)...
Showers should continue to develop and/or move southward across
the area into early this evening. Isolated thunderstorms are
possible until sunset. VFR ceilings will linger into the evening
inland, with 2000 to 3000 foot ceilings near the lake and in
northeast parts of the area. Gusty north winds will continue into
this evening, with gusts to 23 knots at times near the lake.
The showers may linger into the evening hours, perhaps later
tonight in eastern portions of the area. Showers are possible
through tonight into Sunday as well, with the best chances near
Lake Michigan. Ceilings should gradually drop below 1000 feet by
around midnight tonight, lingering into Sunday morning. They
should mix up later in the morning and into the afternoon, with
ceilings above 3000 feet by middle afternoon.
Gusty north winds will linger near the lake overnight. Winds will
become northeast on Sunday, with some gusts to 20 knots possible
near the lake in the morning.
A Small Craft Advisory remains in effect for the nearshore waters
of Lake Michigan through Sunday afternoon. Gusty north winds of
15 to 20 knots, with gusts to 25 knots, are expected during this
period. Waves will be in the 3 to 6 foot range, highest toward the
Beach hazards statement continues for the beaches along Lake
Michigan from Sheboygan through Kenosha County through Sunday
afternoon. Gusty north winds are expected during this period, in
the 15 to 20 miles per hour range. Some gusts to 25 miles per hour may occur. Waves are
expected to be in the 3 to 6 foot range.
The combination of winds and waves will lead to a high swim risk
during this period, which will cause dangerous structural,
longshore and rip currents. Stay out of the water this weekend.
WI...beach hazards statement through Sunday afternoon for wiz052-060-
Lm...Small Craft Advisory until 5 PM CDT Sunday for lmz643>646.