Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1030 AM CDT Thu Oct 23 2025
.KEY MESSAGES...
- Widespread freeze anticipated for all of southern WI overnight
into Friday morning.
- Gradual warm up to just above normal this weekend. Rain
chances (~20-50%) return Sunday night through Wednesday.
&&
.UPDATE...
Issued 911 AM CDT Thu Oct 23 2025
Persistent but gradually weakening nwly sfc winds around the
large occlusion over Quebec will maintain a cold low level
trough over srn WI today. Scattered to broken cloud cover via
stratocumulus will continue today via low level instability.
High temps in the upper 40s to lower 50s still looks good.
The occlusion will finally shift farther away across ern Canada
and New England for tnt-Fri with 500 mb height rises of 120m
tnt then another 60m on Fri. Large scale subsidence and drying
will take hold late tnt when a narrow ribbon of vorticity
maximums that currently extends from wrn Ontario into srn WI
shifts ewd. PWATs will fall below 0.25 inches by 12Z Fri. At the
sfc, the north to south ridge over the Great Plains will move to
wrn WI by 12Z Fri then slowly shift ewd across the state on Fri.
Thus expect clearing skies tnt with some clouds hanging on in
the evening over ern WI. The good radiational cooling conditions
in an already cool airmass should allow temps to drop to 26-30F
well inland and lower 30s over far ern WI. A Freeze Warning is
in effect.
Gehring
&&
.SHORT TERM...
Issued 336 AM CDT Thu Oct 23 2025
Today through Friday:
Low pressure will continue to sit over Quebec today and then
finally pull away tonight. High pressure will slide over WI
overnight through Friday night. Northwest winds will be brisk
again today, but gusts should be less than 20 mph. Stratocumulus
clouds will occur again today, but remain sparse southwest of
Madison. Expect clearing from southwest to northeast through
late evening as high pressure moves in. Winds will drop off
quickly at sunset this evening.
Efficient radiational cooling is expected for areas southwest
of a line from Fond du Lac to Kenosha. With 925mb temps down to
0 to 1C and a modest inversion, surface temps are expected to
drop into the upper 20s. Areas east of this line may take longer
for the winds and therefore temps to drop to around freezing.
Lakeshore areas can expect frost, with a freeze a little more
uncertain. Issued a freeze warning for all counties in srn WI,
although only the far inland areas of the lakeshore counties are
at risk for the hard freeze, with other areas seeing frost.
Light winds and sunshine are expected on Friday. Highs will be
in the lower to mid 50s.
Cronce
&&
.LONG TERM...
Issued 336 AM CDT Thu Oct 23 2025
Friday night through Wednesday:
High pressure remains in place through Friday night, with light
winds and expectations for temperatures in the low 30s once again.
A few areas may dip into the upper 20s due to low winds and clear
skies and therefore very efficient radiational cooling.
Going into Saturday, high pressure exits toward the east, bringing
in southeasterly winds and increasing moisture and temperatures.
Expecting highs in the upper 50s to low 60s. Overnight lows are
expected to remain in the upper 30s and low 40s, with higher
temperatures near Lake Michigan with onshore flow and warm water
temperatures.
Saturday night, low pressure arrives onshore in the Pacific
northwest, propagating over the northern Rockies into Sunday, and
drawing moisture from a weak low pressure system across the
southern Plains up northward and producing the next chances
(15-20%) for rainfall across southern Wisconsin Sunday night.
Phasing between these two systems will dominate the pattern Monday
through Wednesday, with majority of modeling now showing the
northern low pressure system propagating into the Canadian
Prairies and diverging primarily in their solutions for the
southern system.
These divergent solutions seem to be driven by the ways the
tropics behave in the next few days, with the position and
strength of a tropical system steering the southern Plains low. A
stronger system nearer to Florida will serve to drive the
southern Plains low farther south and prevent phasing and
therefore prevent rainfall across southern Wisconsin, while a
weaker system farther from Florida will allow for more phasing
between the cold front of the northern low and the frontogenesis
region of the southern Plains low to bring rainfall and perhaps a
few storms to southern Wisconsin. For now, kept NBM precipitation
chances, with expectations for these to be refined as confidence
in solutions increases. Regardless of phasing, expect generally
southerly winds and near-normal temperatures through midweek, with
a cold front bringing cooler temperatures again into Wednesday
and Wednesday night.
MH
&&
.AVIATION...
Issued 911 AM CDT Thu Oct 23 2025
Areas of MVFR Cigs this morning transitioning to sct-bkn035 for
the afternoon then clearing tnt. Just few-sct035-040 fair wx
cumulus for Fri afternoon.
Gehring
&&
.MARINE...
Issued 336 AM CDT Thu Oct 23 2025
Low pressure over Quebec will gradually progress into
northeastern Quebec through Friday. Northwesterly winds will
remain brisk over Lake Michigan today, but with gusts below 25
kt. Isolated waterspouts remain possible toward the east half of
the lake through the afternoon.
High pressure will build into the Upper Mississippi Valley
today, then cross Lake Michigan tonight into Friday and allow
for light and variable winds. Winds will become southerly on
Saturday as the high moves into Ontario. The high will linger
over Quebec Sunday into Tuesday as broad low pressure moves
into the northern Great Plains, resulting in breezy southeast
winds over Lake Michigan. Winds and waves will likely be
hazardous to small craft from Sunday through Wednesday due to
the persistent onshore flow.
Cronce
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Freeze Warning...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-
WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-
WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...2 AM Friday
to 9 AM Friday.
LM...None.
&&
$$
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