Morenci, Michigan Weather Forecast Discussion

527
FXUS63 KDTX 230920
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
520 AM EDT Tue Sep 23 2025
.KEY MESSAGES...
- A Dense Fog Advisory is in effect for portions of Southeast
Michigan through 9am.
- Scattered showers and thunderstorms will be possible through the
middle of the week. Localized heavy rainfall may be possible.
- Temperatures in the 70s throughout the week which will generally
be at to slightly above normal.
&&
.AVIATION...
Calm winds and saturated near surface conditions have led to the
development of fog, dense at times, that expanded through the Metro
terminals and into KPTK. Dense fog leading to visibilities down to a
half-mile or less is expected to hold generally around the
aforementioned locations, with lower confidence that any dense fog
will make it north into KFNT. Visibilities and ceiling heights will
improve through the later morning hours as daytime heating works to
burn off fog. Periodic isolated to scattered showers with embedded
thunderstorms are again possible this afternoon and evening, with
low confidence regarding timing and coverage. Higher probability
windows are highlighted within PROB30 groups.
For DTW/D21 Convection...Fog, dense at times, will be likely through
the morning hours, with improvement in visibilities and ceiling
heights expected between 12-14Z. Then, additional chances for shower
and thunderstorms development again this afternoon and evening. Low
confidence regarding any thunderstorm timing, with latest guidance
highlighting a possible window between 19Z to 22Z.
DTW THRESHOLD PROBABILITIES...
* High for cigs/vsby to 200ft and/or 1/2sm through the morning.
* Low for thunderstorms to impact DTW this afternoon and evening.
&&
.PREV DISCUSSION...
Issued at 346 AM EDT Tue Sep 23 2025
DISCUSSION...
The main influence on weather over the next few days will be a
thermodynamic environment that includes a moist troposphere below
8.0 kft agl and little to no stability in the column. In fact, model
soundings support unstable conditions continuing during the Tuesday
and Wednesday overnight periods with midlevel lapse rates steeper
than moist adiabatic. PWAT values are projected to hold at around
1.30 inches during the coming days. As a result, the primary concern
through Thursday will be the potential for heavy rainfall with
shower and thunderstorm activity and the possibility of flash
flooding.
For this morning, a lack of surface wind with moist near surface
conditions has led to fog development for the lower elevation areas
south of the Irish Hills. Some HRRR condensation pressure deficit
data suggests this will continue through daybreak or 13Z. Unsure and
uncertain how much fog will really develop or fill in over the urban
heat island but the potential does exist for some fog in Detroit.
Added areas of fog into the forecast and will monitor trends this
morning. If it becomes widespread could issue a Dense Fog Advisory.
Very subtle forcing mechanisms at play today with weak quasi
stationary baroclinic zone hanging out around Saginaw Bay and the
warm sector to the south. Models show closed upper low circulation
meandering very slowly/drifting southward from the U.P. and Lake
Superior likely only accentuating the boundary. A weak upper level
jetlet is shown to eject eastward along the southern periphery of
the closed low directly into Lower Michigan. Plan view of thetae
shows moisture ribbon/higher thetae content advecting into the area
timed with the jet streak. This is forecasted to slide across the
northern cwa invof the aforementioned baroclinic zone this
afternoon. So while precipitation/shower thunderstorm chances will
exist across all of the cwa, the most likely location for activity
is north of the M59 and I 69 corridors. Slow storm movement of west
to east brings the potential for heavy rainfall at any one
location. Difficult to really message rainfall amounts given the
convective setup, but the modeled interquartile ranges of QPF is not
outright concerning.
For tonight, a persistence in elevated instability brings the
potential for additional shower and thunderstorm activity tonight.
Stalled out activity and/or training along boundaries may result in
heavy rainfall.
One big model trend in the latest guidance is for an increase or
convergence in model solutions for vertical velocities late
Wednesday afternoon particularly across the south half of the cwa.
This is in response to upper level low pressure and prior MCV
remnants  phasing into and ejecting northward across the Ohio River
Valley. The trend has been to move timing of this low pressure up
prior to Wednesday night. Latest guidance including the NAM and EPS
membership suggest bulk of the frontogenesis and strong isentropic
lift associated with the near surface circulation will just miss the
area to the south and east. Control run of ECMWF still brings a
direct hit. Obviously, this is something that will need to be
monitored, possibly even a Flood Watch, as any northward jog could
bring heavy rainfall axis into the forecast area under a SHARS type
scenario.
Mainly dry conditions are possible for the end of the week and and
next weekend as models are suggesting midlevel and surface ridging
in place. Despite northwest flow, not seeing any signal for cold air
so above normal temperatures of upper 70s and near 80 degrees is a
real possibility. Humidity values are more uncertain and could be
running a little high in the latest forecast.
MARINE...
An upper level trough is draped over the Great Lakes and will linger
through mid week while slowly dropping southeast. Low pressure
system currently spinning over the northern lakes will help force a
stalled front southward today while additional weak wave may ripple
along the front. This will lead to an extended period of unsettled
weather with multiple rounds of showers with occasional embedded
thunderstorms. Pressure gradient is weak and winds aloft are also
weak so chances of any stronger winds or gusts with storms are
lower. Winds will become northeasterly today behind the front and
remain northeasterly through midweek.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Dense Fog Advisory until 9 AM EDT this morning for MIZ063-068>070-
     075-076-082-083.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....AM
DISCUSSION...CB
MARINE.......DRK
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion