Expert Forecast Opinion

534
FXUS63 KDTX 091910
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
310 PM EDT Thu Apr 9 2026

.KEY MESSAGES...

- Another round of rain showers with possible embedded thunderstorms
develops mainly after midnight tonight lasting through tomorrow
morning.

- Dry weather and cooler but still near normal temperatures tomorrow
afternoon and Saturday.

- Warmer temperatures moving in Sunday into mid-week come with an
active shower and thunderstorm pattern.

&&

.DISCUSSION...

Cold front continues its progression through southeast Michigan this
afternoon as shower coverage gradually wanes across the south. The
cold front is expected to stall out around the southern Michigan by
the end of the end of this afternoon. High pressure settling in
behind the front brings clear skies across most of southeast
Michigan. Gusty afternoon winds from better mixing will decrease
into this evening as lower level flow weakens and the boundary layer
becomes more stable. Low end PoPs(20-30%) and lingering clouds will
remain in the forecast early in the evening along the southern
boundary supported by weak ascent downstream of a mid level wave.

Tonight will see increasing coverage of showers, mainly after
midnight, as the mid level wave moves along this front drawing it
northward and nocturnal low level jet ramps up. Weak mid level lapse
rates and the lack of surface instability will limit the thunder
potential, but a few elevated embedded thunderstorms will be
possible. PWATs increasing towards and inch and potentially reaching
one inch along a narrow corridor arriving with the low-mid level
thetae. A SW to NE axis of rainfall averaging 0.50 to 0.75 inches is
forecast through tomorrow morning, which will be focused across
central to northern portions of the CWA. Any embedded thunderstorm
activity may be able to push localized amounts up towards one inch
of rainfall. Rainfall rates should be held in check for the most
part given the lack of strong instability.

High pressure will build back into the region late Friday bringing
an end to the precipitation chances, but lower level moisture
trapped under an inversion will keep higher coverage of clouds into
Friday night. High pressure center moves directly over Michigan
Saturday morning with increasing subsidence bringing a cloud
clearing trend. Temperatures settle down into the mid 50s for highs
during the afternoon to start the weekend under the mostly clear
skies.

Sunday will see strong warm/moist advection driving by a low
pressure system that will track across the northern Plains clipping
the northern Great Lakes over Lake Superior. Temperatures at 850mb
will surge to 10+C offering well above normal temperatures Sunday
afternoon in the 60s to low 70s. Better moisture will also result in
increasing rain and thunderstorm chances Saturday night/early Sunday
morning along an advancing warm front. The trajectory of this system
will carry rain chances Sunday evening into Monday. Pattern remains
active through the early half of the week with relatively high
confidence in above normal temperatures in the 70s at least through
Tuesday. Models depicting weaker embedded shortwaves early week with
the greater western CONUS trough ejecting into the plains toward mid-
week will be responsible for multiple rounds of rain and
thunderstorm chances during this period. Mid-week period currently
holds the better organized convective potential, but will have to
see how the pattern shakes out with how the ridge across the Eastern
CONUS may affect the inbound Pacific trough. This would direct
greater convective potential to the west.

&&

.MARINE...

Southerly flow gradually decreases this morning and veers toward the
west throughout the day, behind an Ontario low pressure system and
its associated cold front. Strong low level flow tied to the passing
low also departs which ensues peak morning gusts stay below gales,
particularly for central Lake Huron where there was prior concern.
The wave response becomes less prominent as the day continues, but
still exceed Small Craft Advisory criteria for the southern Huron
nearshore zones, therefore an advisory remains in effect. Rounds of
showers decrease from northwest to southeast today, with low
potential for thunder. A wave lifting out of The Plains leads to
additional opportunities for showers and perhaps a thunderstorm
tonight and Friday, while some light snowfall is more likely for the
north/central Huron basin. High pressure then builds out of the
Upper Midwest to start the weekend with drier and weaker northwest
flow. Active weather will be possible again Sunday through Tuesday
due to several passing disturbances. Potential exists for gusts to
gales, mainly late Sunday into Monday.

&&

.HYDROLOGY...

Another round of showers develops mainly after midnight tonight that
lasts through tomorrow morning before ending tomorrow afternoon.
This system brings a SW-NE rainfall axis with amounts focused mostly
across central and northern portions of southeast Michigan. Rainfall
totals average 0.50 to 0.75 inches in a 6 to 12 hour time window.
There is a chance for localized totals near 1 inch where embedded
thunderstorms may develop. Flooding potential remains low with this
event, although the new rainfall could slightly delay drainage from
river and stream systems after the heavy rain that occurred last
weekend.

&&

.PREV DISCUSSION...
Issued at 146 PM EDT Thu Apr 9 2026

AVIATION...

Mid-level moisture ahead of the cold front is focused across far
southeastern MI and will continue to sag south while stalling with
the front along the MI/OH stateline this evening. These clouds and
some showers may persist or redevelop near DTW and YIP late this
evening, but dry low-levels north of the front favor prevailing VFR
conditions into tonight. Wind weakens through the evening while
veering around to north/northeast late. High cloud moves in then
lowers through the early morning as weak low pressure tracks in
along the stalled front. This brings an increasing coverage of light
rain through the morning hours, with MVFR ceilings likely. A period
of IFR is possible, centered between 10z and 18z, then broken MVFR
ceilings are favored through the afternoon as post-frontal
stratocumulus settles across the region. East to northeast wind for
most of the area early tomorrow backs to north then northwest
through the day. The Detroit sites and areas south may see a period
of southwest wind as the front lifts north tomorrow morning, then a
flip to northwest flow in the afternoon.

For DTW...Added a TEMPO group for scattered convective showers in
the 03z to 07z window tonight. Confidence too low for a thunder
mention at this time.

DTW THRESHOLD PROBABILITIES...

* Low for ceilings at or below 5000 ft today. Medium late tonight
into Friday morning. High after 14z.

* Low for thunderstorms late this evening.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 4 PM EDT this afternoon for LHZ421-422-
441>443.

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

$$

DISCUSSION...AA
MARINE.......KGK
HYDROLOGY....AA
AVIATION.....TF


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