NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 060539
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
1239 AM CDT Wed May 6 2026

.KEY MESSAGES...

- Dry and cool conditions are expected through Wednesday night.
  Lows in the lower to middle 30s are expected overnight and
  Wednesday night, bringing widespread frost. A Frost Advisory
  is in effect overnight through early Wednesday morning for
  most areas except along the Lake Michigan shore.

- Scattered showers (20 to 30 percent chances) and a rumble of
  thunder may occur Thursday and Friday with peak daytime
  heating. A brief snow shower may mix in Thursday morning with
  cold temperatures aloft.

- Temperatures are expected to gradually warm up later this week
  through the weekend.

&&

.SHORT TERM...
Issued 1155 PM CDT Tue May 5 2026

Overnight through Friday night:

Scattered to broken middle to high clouds will continue to push
east northeast across the area overnight, gradually becoming
scattered into Wednesday morning. Light and variable winds are
expected overnight into early Wednesday morning.

Lows overnight should drop into the lower to middle 30s in most
areas away from the lake. The Frost Advisory continues for all
of southern Wisconsin overnight into early Wednesday morning.

Broken diurnal stratocumulus clouds should then develop from
middle to late morning Wednesday and linger through the
afternoon. There should be west northwest winds developing again
by midday lingering into the afternoon, with some gustiness at
times. There may also be a southeast lake breeze that develops
in the afternoon for areas near Lake Michigan. Highs should
reach the middle 50s for most areas, with temperatures turning
cooler near the lake in the afternoon.

Another night of frost should occur Wednesday night into early
Thursday morning, with light winds, skies clearing out and
radiational cooling. Lows should drop into the middle 30s for
most areas except near Lake Michigan, with some lower 30s in
spots. Another round of Frost Advisory headlines will eventually
be needed for this period.

Cyclonic flow at 500 mb should allow for some differential CVA
to push through the area Thursday into Thursday night, with some
weak warm air advection trying to focus over or to the south of
the area. Forecast soundings are showing some moisture and weak
instability developing with steep low level lapse rates Thursday
afternoon and evening. Kept small chances (around 20 to 30
percent) for showers in the forecast. There may be a rumble or
two of thunder, as the mean layer CAPE extends above the -10
degree Celsius level. Highs should rise into the upper 50s to
lower 60s Thursday, perhaps cooler near the lake if a lake
breeze develops.

Another round of differential CVA from passing 500 mb vorticity
maxima pushes through Friday into early Friday evening, with
perhaps another push of low level warm air advection. Forecast
soundings show a similar setup with some moisture and weak
instability with peak heating. Kept small chances (20 to 30
percent) for showers Friday into Friday evening. Highs may rise
into the middle 60s inland, with cooler temperatures near Lake
Michigan.

Wood

&&

.LONG TERM...
Issued 1155 PM CDT Tue May 5 2026

Saturday through Tuesday:

500 mb cluster analysis continues to show an elongated and
anomalously deep trough over Ontario Saturday, which shifts
southeast and becomes less deep early next week. This should
keep the area within northwest flow at 500 mb during this time.
Ensemble means are generally showing some warm air advection
developing Saturday, with a cold front pushing southeast through
the area Saturday night.

This should bring warmer temperatures Saturday, along with
better chances (30 to 50 percent) for showers and perhaps a few
storms Saturday into Saturday night. The highest chances would
be in southern portions of the area, where the front will be
with peak heating.

Ensemble means generally bring high pressure through the region
Sunday into Monday, bringing dry conditions and temperatures
closer to seasonal normal values. Low pressure developing in
Minnesota Tuesday may have some warm air advection develop ahead
of it into the area, which may bring the next chances (20 to 30
percent) for showers and a few storms.

Wood

&&

.AVIATION...
Issued 1155 PM CDT Tue May 5 2026

Scattered to broken middle to high clouds will continue to push
east northeast across the area overnight, gradually becoming
scattered into Wednesday morning. Diurnal stratocumulus clouds
around 5000 to 6000 feet AGL should then develop from middle to
late morning Wednesday and linger through the afternoon. Skies
should then scatter out again Wednesday night.

Light and variable winds are expected overnight into early
Wednesday morning. There should be west northwest winds
developing again by midday lingering into the afternoon, with
some gustiness at times. There may also be a southeast lake
breeze that develops in the afternoon for terminals near Lake
Michigan. Light and variable winds are expected once again
Wednesday night.

Wood

&&

.MARINE...
Issued 1155 PM CDT Tue May 5 2026

High pressure around 30.0 inches will continue to slide
southward into the central Plains into Wednesday, bringing light
and variable winds to Lake Michigan. South winds should then
develop Thursday, with south to southwest winds continuing
through Saturday, as high pressure around 30.0 inches remains
across the central Plains. Low pressure around 29.5 inches
should move southeast across portions of the region Saturday
into Saturday night. A passing cold front with the low will turn
winds northwesterly Saturday night into Sunday. High pressure
around 30.2 inches should then build into the western Great
Lakes region later Sunday into Monday.

Wood

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...Frost Advisory...WIZ046-WIZ047-WIZ051-WIZ052-WIZ056-WIZ057-
     WIZ058-WIZ059-WIZ060-WIZ062-WIZ063-WIZ064-WIZ065-WIZ066-
     WIZ067-WIZ068-WIZ069-WIZ070-WIZ071-WIZ072...1 AM
     Wednesday to 8 AM Wednesday.

LM...None.
&&

$$

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