Riverview, Michigan Weather Forecast Discussion

536
FXUS63 KDTX 240704
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
304 AM EDT Wed Sep 24 2025
.KEY MESSAGES...
- Scattered to numerous at times showers with some embedded
thunderstorms are expected through the day.
- Heavy downpours leading to highly localized rainfall amounts will
be possible. This may lead to localized flooding, especially for
urban areas.
- Temperatures in the 70s through the remainder of the week, which
will generally be at to slightly above normal.
&&
.DISCUSSION...
A closed low currently centered across the eastern U.P. is expected
to retrograde into northern lower Michigan today as a secondary
shortwave feature pivots southwest around the parent circulation.
Concurrently, an additional wave progressing eastward across the
Plains will induce some interaction with the parent low with
attempted phasing of the features. Models have struggled with the
overall evolution of the longwave pattern, but this will result in
the deepening the overall trough through the Great Lakes,
maintaining broad ascent and a positive backdrop for for continued
shower and thunderstorm chances today and tomorrow.
Of particular concern for this morning... The latest 00Z hi-res
models output a robust signal for heavy rain from the MI/OH border
up through the urban Metro region, with a secondary signal across
the Thumb. This is derived from a subtle low-level perturbation tha
t will produce a localized zone of enhanced convergence and weak
cyclonic curvature providing a focal point for ascent. While this
signal is not particularly strong and covers a relatively small
spatial domain, the slow storm motion (15 knots or less) and slow
translation speed of the convergence has the potential to sustain
heavy rainfall and training over the same area. Additionally, this
aligns with the pw maxima of 1.25-1.50" (90th percentile w.r.t
climatology), enhancing rainfall efficiency. The ECMWF EFI, while not
particularly sensitive to mesoscale details, highlights this
particular region with values of .7-.8 and SoT > 0, lending
confidence that some locations along and south of I-94 have the
potential to experience some sustained heavy rainfall through the
morning.
Father north into the I-69 corridor through the Thumb, models depict
additional low-level confluence into the late morning hours,
suggesting potential for a secondary rainfall maximum. In any case
under the broader synoptic setup, scattered, to at time numerous,
showers with embedded thunderstorms will be possible for all of SE
MI into the afternoon and evening, which includes highly localized
rainfall totals given any stronger storms and/or training. While
widespread flooding is not anticipated, flood or flash flood
products may be leveraged based on observed trends. Please see the
hydrology section for additional details. Isolated activity is
possible overnight, but coverage will be sparse.
An additional uptick in coverage will be possible during daylight
hours tomorrow, but the signal is not as pronounced with less
mesoscale enhancement. The upper-level trough axis swings out of the
Great Lakes late tonight through Friday morning. A shortwave will
pivot over Michigan Friday evening which bring the low-end chance for
a light shower favored over the Tri-Cities or northern Thumb, but
otherwise high pressure builds over the state through the weekend
into early next week, limiting rain chances.
&&
.MARINE...
Persistent upper level trough over the region will lead to continued
chances for showers and embedded thunderstorms across the region
through Thursday before the trough finally pushes east of the area.
A slow moving front, stationary at times, draped across the region
will be the primary focus for these showers with waves of upper
level support at times. Overall risk of severe weather is low but an
isolated storm may produce a gust near 35 knots or small hail. Wind
field will be light with a weak gradient over the region so winds
and waves should not become a concern in the next few days. High
pressure then builds in for the end of the week bringing quieter
weather to the region again.
&&
.HYDROLOGY...
A storm system lifting northeast across the Ohio valley into
Michigan will produce widely scattered to numerous at times showers
through the day with some embedded thunderstorms. Given slower storm
motion and the potential for heavy downpours, highly localized
rainfall totals will be possible pending any training and
thunderstorm activity. Basin averaged rainfall totals will range
between a half-inch to an inch with highly localized rainfall totals
of 1-3+ inches possible. There is a signal for this higher end
rainfall potential to fall around the MI/OH border and through the
urban Metro regions, but overall confidence of heavy rainfall
timing, coverage, and location is low. Localized flooding of urban,
low-lying, and poor draining areas along with rises in area rivers
will be possible with higher end rainfall totals.
&&
.PREV DISCUSSION...
Issued at 1143 PM EDT Tue Sep 23 2025
AVIATION...
Convection has diminished to isolated showers/thunderstorms as
instability has waned. Expect a redevelopment of
showers/thunderstorms Wednesday as daytime heating develops and
short wave forcing increase. The coverage of mid/high clouds is
adding a degree of uncertainty as to the coverage of fog/low cloud
development overnight into Wed morning. This is most notable at the
Detroit terminals where there is still a respectable temp/dewpoint
spread. This has warranted backing off the LIFR conditions in the
Detroit terminals. From PTK northward, any period of clearing
tonight will support a rapid low cloud and/or fog expansion given
the resident moisture in the low levels.
For DTW/D21 Convection...Any convection during the overnight and
early morning will remain isolated. Thunderstorm chances increase
Wed afternoon, but coverage and timing uncertainties support
refraining from including a mention in the terminals at this time.
DTW THRESHOLD PROBABILITIES...
* High in ceilings aob 5000 feet overnight and Wednesday.
* Low for cigs/vsby to 200ft and/or 1/2sm late tonight/early
  Wednesday morning.
* Low for thunderstorms tonight and Wednesday.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
DISCUSSION...AM
MARINE.......DRK
HYDROLOGY....AM
AVIATION.....SC
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion