博体育

394
FXUS63 KDTX 031717
AFDDTX

Area Forecast Discussion
博体育 Detroit/Pontiac MI
117 PM EDT Sat May 3 2025

.KEY MESSAGES...

* Seasonably cool conditions this weekend with temperatures mainly
in the mid 50s.

* Widespread rain expected Sunday and Sunday night with totals
around a quarter to three quarters of an inch.

* Shower chances continue on Monday with a slight chance of non
severe thunderstorms.

* Gradual warm up back toward normal by middle of next week.

&&

.AVIATION...

Lingering MVFR lower stratocumulus fixated from FNT northward will
gradually mix out through the latter half of the day under generally
drier low level northeast flow. Intervals of thicker high based
cloud will continue to lift across the region through tonight, north
of a broad low pressure system anchored over the Ohio valley. An
increase in low level moisture occurs again late tonight into Sunday
as this system wobbles northward with time. This brings increasing
potential for low VFR to MVFR conditions to emerge from south to
north, with an accompanying chance of rain Sunday.

For DTW/D21 Convection... No thunderstorms expected during this TAF
period.

THRESHOLD PROBABILITIES...

* Low in ceilings aob 5000 feet this afternoon through tonight. High
Sunday.

&&

.PREV DISCUSSION...
Issued at 349 AM EDT Sat May 3 2025

DISCUSSION...

Cool and cloudy weekend begins with rain chances increasing Sunday
through Monday as a cutoff upper low sets up over the region. The
mid/upper level trough is currently over the Midwest and back into
the Central Plains which has placed a surface baroclinic zone just
southeast of the area through Ohio and up the eastern Great Lakes.
Widespread showers are occuring just downstream as an upper level
system tracks through the jet and along the baroclinic zone. Its
proximity is just close enough to our far SE CWA to produce some
light showers overnight. This could continue into the day today as
the longwave trough gets cut off from the stronger Canadian flow and
closes up over the Ohio Valley. As it begins to cutoff, it will draw
the moisture and back into SE MI keeping some showers possible
today. We`ll pretty much be locked into the northerly flow through
the weekend pumping cooler air in the region while the thermal
trough down to around 3C at 850mb stalls over southern MI as well.
Even though most locations will stay dry today outside of Metro
Detroit and Monroe County, clouds will be prevalent helping block
out the early May sun helping produce highs only in the 50s today.

Rain will spread north on Sunday, likely impacting all of SE MI.
Once the upper low get wrapped up tonight, the warm conveyor belt
sets up along the east coast with SE MI being on the westward
extension of the comma. The slow moving cutoff low will keep solid
moisture advection over head all day Sunday with some ribbons of
vorticity releasing up through the area away from the low center.
With PWATs up around an inch all day and prolonged light to moderate
rainfall, most locations will see rain all day. Rainfall totals from
12Z Sunday to 12Z Monday are generally in the 0.25 to 0.75 inch
range but there is a cluster of solutions exceeding 1 inch. Not
expecting any thunderstorms with this activity. Temperatures will
remain in the mid 50s through the day.

Though the low lingers over the region through about Wednesday,
there will be a gradual warm up heading into next week as the
airmass within the cutoff low slowly moderates. Temperatures will
rise back into the mid 60s most of the week with a couple 70s
possible.

MARINE...

Weak upper Midwest high pressure remains the dominant factor today
maintaining generally lighter, 10kt or less, northeast winds with
dry conditions. Exceptions to this are the southern Huron basin and
Saginaw Bay as favorable fetch/shoreline effects nudge winds up
towards 15-20kts. Likewise St Clair and Erie residing closer to the
Ohio Valley low will see similar 15-20kt winds. These southern
waters also could see a shower or two stray north out of Ohio.
Aforementioned low is cutoff Sunday and very slowly wobbles north
through Monday (and potentially through the midweek period)
supporting scattered showers gradually expanding south to north
across the region. A few embedded thunderstorms are possible within
the broader activity, mainly Monday afternoon-evening, though these
are not anticipated to be severe at this time. The drift northward
of the low also expands the 15-20kt NE flow to the remainder of the
area- Saginaw Bay could see gusts closer to 30kts Sunday-Sunday
night. These stronger onshore winds likely will warrant the need for
Small Craft Advisories for at least the Thumb and Bay if not all
nearshore waters.

&&

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

$$

AVIATION.....MR
DISCUSSION...DRK
MARINE.......KDK

You can obtain your latest 博体育 forecasts online
at www.weather.gov/detroit.