Beach Hazards Statement 7, NWS Detroit, MI

891 
WHUS43 KDTX 180710
CFWDTX

Coastal Hazard Message
National Weather Service Detroit/Pontiac MI
310 AM EDT Sun Aug 18 2024

MIZ049-190200-
/O.CON.KDTX.BH.S.0007.240818T1400Z-240819T0200Z/
Huron-
310 AM EDT Sun Aug 18 2024

...BEACH HAZARDS STATEMENT REMAINS IN EFFECT FROM 10 AM EDT THIS
MORNING THROUGH THIS EVENING...

* WHAT...Hazardous Swim Conditions on Saginaw Bay and Lake Huron 
  expected.

* WHERE...Huron County.

* WHEN...From Sunday morning through Sunday evening.

* IMPACTS...Strong currents can pull swimmers into deeper water.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain out of the water to avoid hazardous swimming conditions.

&&

$$

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
758 PM EDT Sat Aug 17 2024

.KEY MESSAGES...

* Occasional Showers and Scattered thunderstorms will persist
  through the end of the weekend.

* Dry and seasonally cool weather can be expected Monday into the
  middle of next week.

&&

.AVIATION...

A closed low pressure system is in place over Southeast Michigan
this evening. Convection has universally weakened the past hour
signifying that lapse rates within the 4.5 and 7.5 kft agl layer are
now limiting updrafts. Prevalence of absolute vorticity will keep
shower activity a possibility through the early evening hours but
given the barotropic nature of the system forecast precision on
timing and location is difficult. A lack of dry air will bring MVFR
ceilings and potential light br overnight. Daytime heating will
bring the potential for shower activity again Sunday afternoon but
coverage is not expected to be as great as today. Modest northwest
winds are anticipated throughout much of the period.

For DTW/D21 Convection...The potential for shower activity exists
this evening. No -tsra is anticipated at this time.

DTW THRESHOLD PROBABILITIES...

*  Low for thunderstorms this evening. Low for Sunday.

*  High for cigs at or below 5000 ft tonight and Sunday.

&&

.PREV DISCUSSION...
Issued at 301 PM EDT Sat Aug 17 2024

DISCUSSION...

The upper low now centered over north central Lower Michigan will
rotate across southern Lake Huron tonight, then drift across across
Ontario on Sunday. There will be an overall decrease in the coverage
of showers/thunderstorms during the evening will the loss in daytime
heating. The exception will be across the Saginaw Valley and thumb
region where short energy pivoting around the low may sustain better
shower coverage into the night. Ample cloud cover with dewpoints in
the 60s will keep min temps in the mid to upper 60s tonight. There
is respectable agreement among the high res solutions suggesting mid
level short wave features pivoting around the back side of the upper
low will support additional rounds of showers and scattered
thunderstorms across the thumb region into Port Huron on Sunday.
Deep layer moisture and cyclonic flow across Se Mi will allow
another uptick in showers/thunderstorms across the rest of the
forecast area Sunday afternoon during the peak in the diurnal cycle.
Thunderstorm chances will be higher along/south of the I-94 corridor
where 0-1km ML CAPE is forecast to peak at 1000 J/kg. The cloud
cover and afternoon convective potential will suppress daytime highs
to the 70s.

Increasing northerly flow and mid level subsidence in the wake of
the retreating upper low and associated sfc low will drive much
drier air across Se Mi Sunday night. Despite clearing skies and
respectable low level cold air advection, the increasing gradient
flow will hold nighttime lows in the 50s. 850mb temps down into the
single digits on Monday will allow a respectable growth of the
daytime mixed layer. Moisture flux off Lake HUron will support a
shallow moist layer which will warrant a healthy afternoon cu field.
20 to 25 knots throughout the mixed layer will lead to a rather
breezy day. The airmass will support seasonally cool daytime highs
ranging from the upper 60s to lower 70s on Monday. Long wave
amplification early next week will feature a building ridge across
the Upper Midwest and troughing/mid level low across eastern Canada
and New England. A strong low level anticyclone/sfc high will reside
across the Great Lakes within this pattern, keep dry conditions with
seasonally cool temperatures through most of the week.

MARINE...

Numerous showers and thunderstorms are ongoing across all waterways
at issuance, with similar coverage expected to carry into the
evening. Activity will wane overnight at the nocturnal minimum, but
is expected to flare up again on Sunday in similar fashion. All of
this is related to an upper low that is currently passing over
northern lower Michigan. Passage of this low has already shifted
winds in some locations to the NW, with uniform northerly flow
developing across all waterways tonight. This flow regime aligns
directly along the long axis of Lake Huron and will cause in uptick
in winds (25-30 knots) and waves (6-8 feet) from Sunday afternoon
through early Tuesday morning. Small Craft Advisories have been
issued as a result. The upper low will gradually vacate into Ontario
early next week, followed by high pressure which will ensure a
quieter mid-week period for the Great Lakes.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 10 AM Sunday to 4 AM EDT Tuesday for
     LHZ421-441.

     Small Craft Advisory from 4 PM Sunday to 4 AM EDT Tuesday for
     LHZ442-443.

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

AVIATION.....CB
DISCUSSION...SC
MARINE.......MV

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

Hazardous Weather Outlook
National Weather Service Detroit/Pontiac MI
312 AM EDT Sat Aug 17 2024

MIZ047>049-053>055-060>063-068>070-075-076-082-083-180900-
Midland-Bay-Huron-Saginaw-Tuscola-Sanilac-Shiawassee-Genesee-Lapeer-
St. Clair-Livingston-Oakland-Macomb-Washtenaw-Wayne-Lenawee-Monroe-
312 AM EDT Sat Aug 17 2024

This hazardous weather outlook is for southeast Michigan.

.DAY ONE...Today and Tonight

Scattered non-severe thunderstorms are possible this afternoon into
tonight.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Scattered non-severe thunderstorms are possible Sunday afternoon and
evening.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.

LCZ460-LEZ444-LHZ361>363-421-422-441>443-462>464-180900-
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-
312 AM EDT Sat Aug 17 2024

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

.DAY ONE...Today and Tonight

Scattered non-severe thunderstorms are possible this afternoon into
tonight.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Scattered non-severe thunderstorms are possible Sunday afternoon and
evening.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed today and tonight.

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

KDK