Pontiac, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

934
FXUS63 KDTX 191629
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1229 PM EDT Thu Mar 19 2026

.KEY MESSAGES...

- Warmer conditions Friday, with a chance of rain showers.

- Above average temperatures will persist into the weekend.

&&

.AVIATION...

West low-level flow under a cold airmass has and will continue to
support a 4kft-6kft stratus deck for the remainder of daylight
hours. Flow will back to the southwest tonight which will cut off
the lake connection, diminishing low-level stratus coverage. Mid and
high based bkn-ovc clouds will filter in upstream from the Plains
late tonight and overnight. A clipper low pressure system will drop
in across northern lower Michigan bringing a chance for light rain
showers across southern Michigan. KMBS will have slightly higher
probabilities to see several hours of rain showers given closer
proximity to the low, with lower confidence to observe rain showers
for locations south.

DTW THRESHOLD PROBABILITIES...

*  Low confidence in ceilings at or below 5000 feet through this
   afternoon and evening.

&&

.PREV DISCUSSION...
Issued at 204 AM EDT Thu Mar 19 2026

DISCUSSION...

Lower amplitude mid level northwest flow will continue to govern
conditions to finish the work week period. Minor perturbation
embedded within the mean flow will translate across the region
today. This occurs atop a stalled elevated frontal zone and
associated narrow low level moist plume. Minimal signal to suggest
anything outside of a lower probability for light qpf production /if
any/ at a very limited scale and duration as weak ascent washes
through today. Forecast will continue to highlight simply a low end
potential targeting south of I-96. Surface temps flirting near
freezing at daybreak may allow for a couple observations of light
freezing drizzle or flurries as moisture depth fluctuates,
particularly in the Irish Hills. No meaningful icing concerns given
the expected brevity in occurrence, with temperatures then
accelerating above freezing post-daybreak. Highs arriving in the 40s
most locations, as a window of modest cold air advection atop the
boundary layer proves minimally impactful.

Another low amplitude wave set to traverse the northern great lakes
Friday. Projected system trajectory ensures the meaningful
associated ascent and moisture advection within a broader region of
warm air advection holds well to the north. Sounding data offers a
generally dry and stable diurnal profile both with the modified
early day warm sector and within the immediate post-cold frontal
environment. Forecast will continue to highlight a lower probability
for the southern expanse of more direct frontal forcing to glance
across mainly the thumb region late Thursday night into early
Friday. Frontal timing potentially stunting the magnitude of warming
across the north, lending to a greater south to north thermal
gradient with above average highs ranging from lower 60s to upper
40s.

No significant wx through at least Saturday. SE Michigan will reside
south of the governing north pacific upper jet and within a quasi-
zonal mid level flow north of a broadening southern conus ridge.
Moderating thermal profile across this window maintains certainty
for continued above average temperatures with dry conditions under
high magnitude stability Saturday. Subtle height falls as the upper
jet bends southward will draw an east-west elongated baroclinic zone
across the lower peninsula Saturday night into Sunday. Limited
residence time for meaningful forced ascent along the advancing
elevated frontal slope before drier east flow south of expansive
high pressure aggressively takes control. Forecast offers an
appropriate chance mention for a mix of light rain and snow centered
on Sunday morning, with pace of the cold air advection relative to
precip timing carrying some uncertainty yet for ptype. Frontal
timing with dictate whether notably colder post-frontal conditions
for the latter half of the weekend or hold off until early next
week.

MARINE...

Low pressure departing northeastern Ontario leaves a weak frontal
boundary draped across the Great Lakes today with light,
disorganized flow in place. Southerly winds then increase to around
15 to 20 kt Friday morning as a clipper system arrives over the
northern lakes. Light snow is possible across northern Lake Huron,
otherwise mainly light rain is favored as milder air works into the
region. Wind shifts to northwest at around 15 kt as the system
quickly departs late Friday, then a weaker pressure pattern
maintains relatively light and disorganized wind on Saturday. A
strong cold front sinks across the region on Sunday with gusty
northeast wind of 20 to 30 kt. Probability for gales is low at this
time, but Small Craft Advisories will likely be needed across
southern Lake Huron due to wave heights around or above 4 feet.
Expansive high pressure builds in behind the front on Monday.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....AM
DISCUSSION...MR
MARINE.......TF


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