Saginaw, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

669
FXUS63 KDTX 161955
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
355 PM EDT Thu Jul 16 2026

.KEY MESSAGES...

- The Air Quality Alert remains in effect for the rest of today
  through Friday due to persistence of wildfire smoke causing
  hazardous air quality.


- Improvement of smoke concentration begins Friday night as wind
  shifts SW after passage of a warm front.

- Thunderstorm potential increases with scattered coverage Friday and
  Friday night. Severe intensity is not expected.

- There is a Marginal Risk of severe intensity thunderstorms as
  coverage becomes numerous Saturday afternoon and evening.

- Dry weather with cooler temperatures and lower humidity moves in
  by Sunday.

&&

.DISCUSSION...

Afternoon GOES West and recently restored GOES East satellite
imagery show the expansive plume of forest fire smoke extending from
the MN/Ontario border, over the Great Lakes, and into the mid
Atlantic states. The plume is fortified by stable high pressure
similarly aligned which is only allowing incremental visibility
improvement as a proxy for density/concentration. Boundary layer
mixing is clearly also limited by the cooling effect of the smoke on
daytime heating that is limiting temperatures to the lower and mid
80s most locations. Nocturnal surface layer stabilization after
sunset combines with just a slow eastward drift of high pressure to
maintain similar smoke density tonight and Friday morning.

The next low pressure system, organizing in the northern Plains
tonight, moves into the upper Midwest Friday. It offers an
opportunity for smoke improvement over Lower Mi but not until Friday
night as the surface warm front approaches from the mid MS/OH
valleys. Until then, HREF and REFS mean QPF projects convection
along and west of the warm front Friday afternoon which matches up
well with hi-res versions of the NAM and RAP. This timing has sub-
severe thunderstorms moving from the west toward SE Mi with isolated
to scattered coverage late in the day and Friday evening. The warm
front then moves SW to NE to help displace the smokey air mass into
Ontario late Friday night.

The warm front moves into Ontario as low pressure reaches just north
of the Straits by Saturday morning. There is good model agreement on
this solution which places nocturnal/elevated convection mainly over
the northern Great Lakes and northern Ontario Friday night, and
places SE Mi in the warm sector of the system through Saturday
morning. The trailing cold front is strongly supported for this time
of year by the parent mid level short wave tracking over the
northern Great Lakes, enough to maintain a band of showers and
thunderstorms along the front Friday night and Saturday morning as
the front moves through northern Lower Mi. REFS mean surface based
CAPE is in the 1000-2000 J/kg range as the front enters central and
SE Mi during the morning rising to around 2500 J/kg Saturday
afternoon. The broad instability axis combines with the southern
fringe of faster flow aloft to set up a respectable storm
environment. Model forecasts of 0-6 km bulk shear averaging 30 knots
presents an opportunity for organized thunderstorms Saturday
afternoon until the front exits into Ontario and Ohio Saturday
evening. SPC maintains a Marginal Risk for severe storms in SE Mi in
the Day 3 update and this looks solid.

Passage of the cold front Saturday evening ushers in dry weather
with cooler and less humid conditions Sunday into early next week.
Extended range global models project a prolonged period of mid level
trough development from Hudson Bay into southern Ontario. Low
pressure systems track through this long wave pattern and reinforce
cooler air across Lower Mi during the early to mid week period. This
results in temperatures closer to, or even below normal, with lower
potential for thunderstorms.

&&

.MARINE...

Dense smoke due to Canadian wildfires persists across the entire
central Great Lakes today and into tomorrow. This supports the
continuation of a Dense Smoke Advisory until 4 AM Friday for
visibilities AOB 1 NM. Additional extensions in time may still be
needed. Weak high pressure influence over the central Great Lakes
maintains light north-northwest winds through this afternoon,
although speeds may approach 20 knots over the northern half of Lake
Huron where the pressure gradient is more constricted. Weak low
pressures systems emerge over the northern Plains and Mid-
Mississippi Valley tonight, eventually converging over the Great
Lakes with time on Friday. This leads to more active weather with
periods of showers and thunderstorms arriving later in the day.
Prevailing winds should generally remain below headline criteria
through the forecast period, with one exception being marginal Small
Craft Advisory gusts over Saginaw Bay and/or The Thumb nearshores
Saturday afternoon. This arises within the wake of a cold front
associated with a secondary, and more robust, low pressure system
passing through The Straits on Saturday. High pressure builds back
into the region late Saturday and Sunday supporting drier conditions.

&&

.PREV DISCUSSION...
Issued at 130 PM EDT Thu Jul 16 2026

AVIATION...

Smoke remains entrenched across the region today and tonight with
only minimal improvements to current conditions expected. Smoke
thickness has limited the effects of diurnal mixing with most sites
still MVFR cigs with LIFR vsbys early this afternoon. Given the lack
of improvement thus far, went pessimistic with potential improvement
to low VFR cigs/IFR vsbys. Would expect a regression in conditions
again overnight as smoke is aids in generating areas of fog to mix
in.

D21/DTW Convection...No convection is forecast through tonight.

DTW THRESHOLD PROBABILITIES...

* High for ceilings at or below 5000 feet today.

* Moderate for vsbys below 1/2SM early this afternoon, low by late
  afternoon.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...None.

Lake Huron...Dense Smoke Advisory until 4 AM EDT Friday for LHZ361>363-421-422-
     441>443-462>464.

Lake St Clair...Dense Smoke Advisory until 4 AM EDT Friday for LCZ460.

Michigan waters of Lake Erie...Dense Smoke Advisory until 4 AM EDT Friday for LEZ444.

&&

$$

DISCUSSION...BT
MARINE.......KGK
AVIATION.....KDK


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