National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KMKX 160254
AFDMKX

Area Forecast Discussion
National Weather Service Milwaukee/Sullivan WI
954 PM CDT Mon Apr 15 2024

.KEY MESSAGES...


- Rounds of showers and storms will likely (60-85%) bring over
  an inch of rain Tuesday afternoon through Wednesday afternoon
  with pockets of 2-2.50 inches or more possible especially
  over south central WI.

- There is a conditional severe threat for far south central WI
  Tuesday afternoon and evening.

&&

.UPDATE...
Issued 952 PM CDT Mon Apr 15 2024

Dry conditions are expected to continue overnight with
increasing clouds as the low pressure across the plains moves
north towards Wisconsin. Recent CAMs depict some showers and
storms developing across southern Wisconsin around noon on
Tuesday ahead of the main theta-e advection associated with the warm
front, but any storms that develop at that time are expected to
remain sub-severe given an overall lack of instability and
forcing.

Attention still remains on the potential for severe storms and
heavy rainfall Tuesday afternoon and evening as the low moves
into the region. Model guidance continues to indicate MUCAPE of
around 1000 J/kg across southwestern Wisconsin and 0-6km shear
of 40-50KT which combined with forcing from the warm front
associated with the low, would provide a catalyst for severe
weather. However, given the expected cloud cover tomorrow, there
remains the question of how much destabilization will occur.
Regardless, strong winds and hail remain the primary threat,
although an isolated tornado or two cannot be ruled out.

Falkinham

&&

.SHORT TERM...
Issued 308 PM CDT Mon Apr 15 2024

Tonight through Tuesday night:

A sfc ridge continues to slowly shift ewd this afternoon while a
lake breeze is gradually moving inland. Another very mild day
with very low relative humidity is occurring.

For tnt and Tue AM, strong low pressure will move from the
central high plains and across NE. Ely winds and clouds will
increase with only 20-30 percent chances of showers and storms
over sw WI through noon. Afterward, strong low to mid level thetae
advection is expected ahead of the occluded low and negative
tilt upper wave. An ATM river with PWs of 1.2-1.4 inches will
arrive with the warm front reaching far sw WI around early
evening, although some of the strongest convection may go
through beforehand. Thus much of srn WI will see elevated
showers and storms but with mdt effective shear and MUCAPE of
1000-1500 J/KG especially toward sw WI where the frontal
inversion won`t be as deep. Thus the highest SVR potential for
large hail and damaging winds will be along and west of a line
from WI Dells to Madison to Janesville with lesser chances to
the east. Heavy rainfall will also occur with the HREF PMM
producing rain accum of 2-2.50 inches over sw WI and portions
of south central WI. Will message both the SVR risk and heavy
rainfall.

A dry slot will arrive late Tue evening into the overnight while
a narrow warm sector will lift into srn WI. The cold front or
occluded front will then pass from early Wed AM to late morning
as the occluded low tracks to west central WI by 18Z Wed. There
does appear to be enough instability and CAPE for another round
of showers and storms but with high uncertainty on SVR
potential.

Gehring

&&

.LONG TERM...
Issued 308 PM CDT Mon Apr 15 2024

Wednesday night through Monday:

The low will move away by Wed evening with declining winds and
little to no pcpn left. A large upper low will then move along
the Canadian/US border with shortwave troughs rotating through
the nrn Great Plains into the Great Lakes. 850-700 mb
frontogenesis associated with the features will bring rain
chances of 30-50 percent for Thu into Thu eve. A cold front will
then follow with a prolonged period of nwly winds until high
pressure arrives for Sun-Mon. High temps only in the 50s and
lows in the 30s are forecast for Fri-Sun with perhaps 60F on
Mon.

Gehring

&&

.AVIATION...
Issued 952 PM CDT Mon Apr 15 2024

Primarily VFR conditions are expected throughout the TAF period.
Gusty east winds are expected on Tuesday as the low across the
Great Plains moves north towards Wisconsin, with cloud cover
increasing throughout the day. MVFR ceilings are expected to
develop by Tuesday evening as the warm front moves through
southern Wisconsin. Showers and thunderstorms are also expected
to accompany the warm front and low as they traverse the area,
with visibilities and ceilings falling to IFR conditions in
areas of heavier rainfall.

Falkinham

&&

.MARINE...
Issued 308 PM CDT Mon Apr 15 2024

Light and variable winds will become east to northeast over all
of the open lake by late afternoon. Easterly winds will then
develop and increase late tonight into Tuesday morning over the
south half of the lake as low pressure of 29.2 inches approaches
from the Central Plains. Brisk easterly winds are expected by
Tuesday evening with a potential for gales over much of the lake
into Wednesday. A Gale Watch is now in effect for this period.

The low will slowly move across central Wisconsin on Wednesday
reaching northern or central Lake Michigan Wednesday evening with
a central pressure around 29.5 inches. The brisk southeast winds
over the southern half of the lake will shift southwesterly
Wednesday afternoon, while brisk and possible easterly gales will
continue across the far northern portion of the lake. The winds
will finally turn westerly but much weaker for late Wednesday
night over the far north. Light to modest westerly winds Thursday
morning will then turn southwest for the afternoon across the
entire lake. For the nearshore waters from Sheboygan to Winthrop
Harbor, a Gale Watch is in effect Tuesday night.

Gehring

&&

.MKX WATCHES/WARNINGS/ADVISORIES...
WI...None.
LM...Gale Watch...LMZ080-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-
     LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
     LMZ874-LMZ876-LMZ878...6 PM Tuesday to 10 AM Wednesday.

     Gale Watch...LMZ261-LMZ362...6 PM Tuesday to 7 PM Wednesday.

     Gale Watch...LMZ643-LMZ644-LMZ645-LMZ646...6 PM Tuesday to 7
     AM Wednesday.

&&

$$

Visit us at weather.gov/milwaukee

Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSMilwaukee
www.twitter.com/NWSMilwaukee
www.youtube.com/NWSMilwaukee