Macomb, Michigan 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

384
FXUS63 KDTX 262017
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
417 PM EDT Thu Jun 26 2025

.KEY MESSAGES...

- Scattered to numerous thunderstorms continue this afternoon after
  shifting north toward the I-69 corridor.

- A Marginal Risk of severe storms may lead to damaging down burst
  winds. Localized flooding is also possible due to very moist
  airmass and saturated soils from recent storms this week.

- Yet another round of thunderstorms is likely Friday as a cold front
  moves through Lower Michigan. There is a Marginal Risk of severe
  intensity during the afternoon and evening.

- High temperatures increase back to the upper 80s to 90 degrees
  Friday and Sunday after a brief cool down Saturday.

&&

.DISCUSSION...

An interesting progression of thunderstorm development from this
morning continues to unfold across the area this afternoon and
evening. Broad scale support for nocturnal/elevated convection late
last night resulted in storms grazing the Tri Cities and Thumb
around sunrise this morning. The larger scale support, mainly near
the entrance region upper jet circulation, helped the 850-700 mb
theta-e ridge percolate over southern Lower Mi all morning until
becoming surface based toward noon. A messy multicell convective
mode dominated since then and which has migrated south of the Ohio
border after forecast issuance. Lingering severe potential, for
mainly damaging wind and heavy rainfall, has shifted farther north
to the hybrid marine layer/surface front. This has released new
storms where MLCAPE projections show a 2000 J/kg instability axis
through early evening. In all cases, precip loaded damaging wind
gusts are the primary severe hazard followed by heavy rainfall. Hail
is a distant third given the deep moisture profile and low CAPE
density in the mid levels.

The ongoing storms across Lower Mi are expected to dissipate with
the loss of heating tonight, in time to look toward the Midwest
where another low pressure system is interacting with the resident
surface front across the Great Lakes. Surface based storms out there
are also expected to diminish/dissipate on the downward side of the
heating cycle followed by a new transition to low level jet forced
convection tonight. The surface low moves into NW WI while pulling
the front back north into northern Lower Mi late tonight and Friday
morning. This presents a dry warm sector scenario for SE Mi and a
more favored nocturnal MCS track north of the Tri Cities late
tonight into Friday morning.

Yet another round of thunderstorms is likely for SE Mi Friday
afternoon as the WI surface low continues into northern Ontario
while dragging a cold front across Lower Mi. The solid warm sector
in place over the area is HREF projected to build SBCAPE up to
around 2000 J/kg ahead of the front. Bulk shear is also advertised
to be on the low side, however a deeper dive into model soundings
indicates unidirectional mid level flow around 35 knots with some
dry air around the 500 mb level. The big CAPE helps with the lower
end wind field for storms evolving into line segments along the
front with damaging wind potential the primary hazard, as good or
better than SPC`s Marginal Day 2 outlook for our area into Friday
evening.

The Friday cold front ushers weak high pressure into the area for
Saturday, slightly cooler and a little less humid. This reverses
Sunday as the next low pressure system moves into the Great Lakes
and brings highs back up near 90. The front associated with this
system leads to a larger scale pattern shift resulting in at least
lower humidity with greater staying power next week.

&&

.MARINE...

Marine conditions remain unsettled in terms of thunderstorms this
afternoon through Friday while wind and waves are otherwise subdued
outside of the storms during this time. The current center of low
pressure in the Midwest moves eastward along a frontal zone that has
been wavering across Lake Huron and Lower Michigan over the last
couple days. The low moves across the Straits Friday and pulls a
weak cold front southward through Lower Michigan and into the Ohio
valley Friday night. Light wind and favorable weather follow with
weak high pressure Saturday followed by another low pressure system
entering the northern Great Lakes during Sunday through Sunday
night. This system brings a stronger cold front into Lake Huron and
Lower Michigan to start next week.

&&

.PREV DISCUSSION...
Issued at 125 PM EDT Thu Jun 26 2025

AVIATION...

Moderately unstable, uncapped environment over southeast Michigan,
with frontal boundary/dew pt gradient near the I-69 corridor.
Disorganized strong thunderstorms should continue, but location is a
bit challenging as outflow boundaries serve to focus additional
redevelopment.  None-the-less, multiple rounds of showers/storms
across southern TAF sites looks reasonable, and will be maintaining
the tempo TS group through the afternoon, although concerned with
the latest drift to the south with the bulk of the activity.
As low pressure enters the Western Great Lakes this evening, the
surface boundary over Lower Michigan will attempt to lift north,
providing better focus over MBS/FNT for the evening hours. With the
elevated low level moisture/high surface dew pts over southeast
Michigan tonight, much better chance for low clouds and/or some fog,
depending on how thick mid/high clouds from upstream activity over
the Western Great Lakes advances east. However, with today`s
rainfall, enough confidence in MVFR stratus and/or fog development to
include in tafs, with very light southerly winds tonight, IFR not
out of the question, especially at MBS. Another round of showers and
thunderstorms appears likely tomorrow afternoon as cold front
arrives during peak heating. Southwest wind gusts ahead of the front
will likely reach into the 20-25 knot range in the afternoon, in
addition to the stronger/gustier winds in any thunderstorm.

For DTW/D21 Convection...Bulk of storms over southern Lower Michigan
are showing signs of propagating southeast, away from terminal. Thus
lower confidence for the rest of the afternoon. None-the-less, would
expect enough destabilization to trigger additional storms late this
afternoon, and will keep much of the inherited taf intact.

 THRESHOLD PROBABILITIES...

* Low to medium for thunderstorms this afternoon and evening.

* Low in ceilings aob 5000 feet through evening. Moderate overnight
  and tomorrow afternoon.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.

&&

$$

DISCUSSION...BT
MARINE.......BT
AVIATION.....SF


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at www.weather.gov/detroit.