NWS-Milwaukee/Sullivan Forecast Discussion

						FXUS63 KMKX 071031
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
531 AM CDT Thu May 7 2026

.KEY MESSAGES...

- Widespread frost across southern WI early this morning.
  Additional frost chances Tonight/Friday morning for inland WI,
  especially towards central WI.

- Small chances (10-30%) for scattered light rain showers in the
  daytime hours Today thru Saturday.

- Warmer temps Friday and Saturday (highs in the 60s, then
  closer to 70).

- Roughly 60% chances for light rainfall next Tuesday.

&&

.UPDATE...
Issued 530 AM CDT Thu May 7 2026

Latest model trends have trended drier but the NAM seems to be
capturing at least where echoes exist and given the surface
being not terribly dry there is at least a chance some of this
is reaching the surface. This also lends some credence to the
NAM for the rest of today and thus despite the drier trend we
will maintain the 20-30% chances for much of the CWA today for a
shower and maybe even a rumble of thunder. Otherwise a frosty
morning but is expected to rise to the upper 50s today.

Kuroski

&&

.SHORT TERM...
Issued 100 AM CDT Thu May 7 2026

Today and Tonight:

The Frost Advisory remains in effect through 8 AM CDT this
morning, with overnight low temps expected to bottom out in the
low 30s to around 30 degrees flat. Some areas could easily fall
to the upper 20s, particularly west of a Green Lake to
Burlington line (where clouds cleared out faster this evening).

Daytime highs in the 50s to around 60 expected this afternoon
(warmest towards southwest WI). A westerly breeze around 10 MPH
occasionally gusting to 20 in the afternoon will kick in later
this morning, subsiding late in the afternoon. A southeasterly
lake breeze may push back against it, confined to the immediate
shoreline until the prevailing winds subside later in the
afternoon.

A passing 500mb trough and a pocket of cooler air aloft may form
some open cellular (popcorn-style) light rain showers out of the
broken high-based cumulus clouds today, though we've reduced
rain chances to 10-30%. For most areas, these rain showers
should evaporate before reaching the ground. A stray rumble of
thunder cannot be completely ruled out, but is growing less
likely with time (15% chance or less). Rain chances and cloud
coverage erode quickly as the sun angle decreases this evening,
leaving dry weather and mostly clear skies tonight.

Sheppard

&&

.LONG TERM...
Issued 100 AM CDT Thu May 7 2026

Friday through Wednesday:

Ensemble temperature plumes show a continued warming trend Friday
into Saturday, with light southwesterly winds and a chance for a
shoreline lake breeze Friday, followed by modest southwest winds and
no lake breeze Saturday. The warmth should peak Saturday afternoon
with highs in the upper 60s to around 70. Broad high pressure over
the southeastern CONUS and broad low pressure over central Canada
should form a zone of confluence / strong low to mid level WAA over
IL on Friday, with only 5-15% chances for stray shower activity from
that to meander into southern WI. For Saturday, a shortwave trough
and cold front (extending southwest of the Canadian low pressure)
sweep southeastward across Wisconsin, with the surface to 700mb WAA
refocusing over our region Saturday morning followed by the frontal
passage sometime in the afternoon (plenty of dispersion on the exact
time). There will be chances for scattered light rainshowers ahead
of and along the front (through the daytime hours Saturday), but the
latest model guidance decreases Saturday's precip chances from ~45%
to ~25% on account of a drier and well mixed PBL ahead of the front.
For both the Friday and Saturday shower chances, a few rumbles of
thunder cannot be completely ruled out, but storms are expected to
be weak if applicable, and ensemble + deterministic model CAPE has
decreased since the last forecast iteration. As such, the "slight
chance of thunder" wording has been removed from the forecast for
now.

High temperatures fall into the 50s to around 60 behind the front on
Sunday, with a northwest synoptic breeze and shoreline lake breeze
possible. Passing high pressure and weaker winds on Monday should
allow for a more progressive lake breeze (at least 1 county inland,
progressing further late in the afternoon), keeping shoreline
temperatures in the 50s, though inland temperatures moderate upwards
a few degrees. The slow warming trend continue through mid next week.

The only substantial precip chance through the forecast period is
Tuesday (~60%) on account of a passing clipper system, with a
relatively good consensus between GFS/ECMWF guidance. The fast
moving nature of this system ought to limit the expected QPF, with
the GEFS only resolving 10-20% chances of reaching half an inch. The
arrival time and intensity of this system will continue to be
monitored.

Sheppard

&&

.AVIATION...
Issued 530 AM CDT Thu May 7 2026

VFR TAF period is expected with modest west winds and a chance
for a shower today and maybe a rumble of thunder. Either way
CIGS and VSBYS expected to remain VFR with no concerns into
Friday either with modest west to southwest winds. There is a
small chances for the lake breeze to kick in near the lake but
would not be expected to make it very far west.

Kuroski

&&

.MARINE...
Issued 100 AM CDT Thu May 7 2026

High pressure around 30.0 inches will continue to work south-
southeastward across the central Plains with light and variable
winds continuing over Lake Michigan overnight. South to
southwesterly winds will develop for Thursday and continue
through Saturday as the high pressure slides further southeast
across the Lower Mississippi River Valley. However, winds will
then increase ahead of a developing low pressure around 29.5
inches tracking north of the Great Lakes into Quebec for
Saturday before dragging a cold front southward across Lake
Michigan later in the day. Winds shift to the north-northwest
behind the front for Sunday while high pressure around 30.2
inches builds down across the region into the start of next
week.

Sheppard

&&

.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 until 8 AM
     Thursday.

LM...None.
&&

$$

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