Beach Hazards Statement 8, NWS Detroit, MI

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1158 PM EDT Sat Aug 1 2026

.KEY MESSAGES...

- Intervals of showers will persist overnight and early Sunday.
  Potential exists for heavy rainfall to develop at times.

- Dry weather returns on Monday, but it may become unsettled again for
  parts of next week with chances of showers. Temperatures will be
  close to average for early August.

&&

.AVIATION...

An area of deeper low level moisture lifting north of low pressure
tracking through the Ohio valley will track into the region
throughout the early-mid morning period. This will increase the
probability for showers to increase coverage and intensity,
particularly across the Detroit airspace up through PTK. This will
occur as cloud base declines from lower VFR into MVFR with time
through the morning hours. A brief period of IFR also plausible. A
lower probability remains for embedded thunderstorms to develop
anytime Sunday morning across this corridor, but confidence in
occurrence remains quite low. Gradual drying from northwest to
southeast will work to lift lingering MVFR back into VFR as showers
slowly exit to the east Sunday. Prevailing northeast through the
period, turning modest gusting Sunday afternoon.

D21/DTW Convection... There is a low chance of thunderstorms
late tonight and Sunday morning.

.DTW THRESHOLD PROBABILITIES...

* Medium to high for ceiling 5000 ft or less overnight and Sunday.

* Low for thunderstorms Sunday morning.

&&

.PREV DISCUSSION...
Issued at 319 PM EDT Sat Aug 1 2026

DISCUSSION...

A west-east axis of showers and embedded thunderstorms has begun to
develop this afternoon along an broad axis of surface convergence as
deeper moisture lifts north. This area is currently along/near the M-
59 corridor and expected to slowly lift north towards the I-69
corridor through this evening. This mornings raob from DTX showed
PWATs above the 90th percentile for this time of year and a narrow
pocket of elevated instability between 1-6km. Latest RAP analysis
also shows this area generally uncapped, thus this pocket of
instability is likely now surface based. While instability is not
all too impressive, the warm, moist environment remains favorable
for higher rainfall rates with any thunderstorm activity. Rainfall
this afternoon and into tonight will be highly variable and
dependent on where slow moving thunderstorm activity tracks.

Afternoon surface and satellite analysis show both the surface and
upper-level low across central Illinois. With the low already having
occluded across the Midwest and the upper-level wave becoming
cutoff, it will be very slow to move east over the next 24-36 hours.
Another wave of energy is progged to dig south across the region
tonight and through Sunday, helping move the system along to the
east. With these two waves of energy approaching the area through
Sunday, there remain uncertainties in how the potential for heavy
rain and training convection evolve. There will be multiple rounds of
large-scale ascent that move through the region, which will favor a
few windows of convection that look to remain loosely organized.
Thus, it remains very difficult to pinpoint where any axis of
training convection could set up and bring possible urban flooding
concerns, so have opted to hold off on a Flood Watch. Expect at least
0.5-1 inch of rain late tonight through Sunday. Locally higher
totals if we get into a training scenario with embedded
thunderstorms.

Early next week, high pressure moves in behind the departing system
and we should have a few drier days with seasonable temperatures in
the lower 80s. With warm air advection moving back into the region
ahead of another system tracking east across the upper great lakes
and central Canada, we should see a gradual warming trend through
mid to late week.

MARINE...

Northeast flow picks up across the central Great Lakes tonight and
especially Sunday afternoon as a low pressure system over the lower
Ohio Valley lifts northeastward. Strongest flow will channel across
Saginaw Bay leading to Small Craft Advisory conditions. Similar
concerns for the rest of the Lake Huron nearshore, but will
reconsider an extension with the evening update. Chances for rain
and thunderstorms continue through the remainder of the weekend as
the low and its associated frontal features approach. Isolated
storms could produce locally strong winds and elevated waves today
through Sunday. High pressure influence becomes entrenched across
the region Monday offering drier weather and weaker winds, with
headline-free conditions.

HYDROLOGY...

Scattered to numerous showers with embedded thunderstorms are
forecast this afternoon into Sunday. Heavy rainfall rates are still
possible, especially with any thunderstorm activity. Localized
rainfall totals may exceed 2 inch where persistent training
convective activity develops. This may lead to isolated flooding
concerns this weekend, particularly in urban areas.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 8 AM to 10 PM EDT Sunday for LHZ421-422.

     Small Craft Advisory from noon Sunday to 4 AM EDT Monday for
     LHZ441>443.

Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

AVIATION.....MR
DISCUSSION...JA
MARINE.......KGK
HYDROLOGY....JA

You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

Hazardous Weather Outlook
National Weather Service Detroit/Pontiac MI
303 PM EDT Sat Aug 1 2026

MIZ047>049-053>055-060>063-068>070-075-076-082-083-021915-
Midland-Bay-Huron-Saginaw-Tuscola-Sanilac-Shiawassee-Genesee-Lapeer-
St. Clair-Livingston-Oakland-Macomb-Washtenaw-Wayne-Lenawee-Monroe-
303 PM EDT Sat Aug 1 2026

This hazardous weather outlook is for southeast Michigan.

.DAY ONE...This Afternoon and Tonight

There is a chance for thunderstorms through. Severe weather is not
anticipated, but there is a marginal threat for localized heavy
rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

There is slight chance of thunderstorms Sunday. Severe weather is
not anticipated, but there is a marginal threat for heavy rainfall.

.SPOTTER INFORMATION STATEMENT...

LCZ460-LEZ444-LHZ361>363-421-422-441>443-462>464-021915-
Lake St Clair-
Michigan Waters of Lake Erie from Detroit River to North Cape MI-
Lake Huron from 5NM east of Mackinac Bridge to Presque Isle Lt
beyond 5 NM off shore-
Lake Huron from Presque Isle Light to Sturgeon Point MI beyond 5NM
off shore-
Lake Huron from Sturgeon Point to Alabaster MI beyond 5NM off shore-
Outer Saginaw Bay SW of Alabaster to Port Austin MI to Inner Saginaw
Bay-Inner Saginaw Bay SW of Point Au Gres to Bay Port MI-
Port Austin to Harbor Beach MI-Harbor Beach to Port Sanilac MI-
Port Sanilac to Port Huron MI-
Lake Huron from Port Austin to Harbor Beach beyond 5NM Off Shore-
Lake Huron from Harbor Beach to Port Sanilac beyond 5NM Off Shore-
Lake Huron from Port Sanilac to Port Huron beyond 5NM Off Shore-
303 PM EDT Sat Aug 1 2026

This hazardous weather outlook is for portions of Lake Erie, Lake
Huron and Lake St Clair.

.DAY ONE...This Afternoon and Tonight

There is slight chance of thunderstorms through tonight. Severe
weather is not anticipated, but there is a marginal threat for
localized heavy rainfall.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

There is slight chance of thunderstorms Sunday. Severe weather is
not anticipated, but there is a marginal threat for heavy rainfall.

.SPOTTER INFORMATION STATEMENT...

You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

JA