Expert Forecast Opinion

776
FXUS63 KDTX 220723
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
323 AM EDT Wed Jul 22 2026

.KEY MESSAGES...

- Dry conditions with temperatures dipping below average during the
mid to late week period.

- Next chance at precipitation Saturday night into Sunday.

&&

.DISCUSSION...

Deep H3 to H5(sub 560dam) troughing is in place across all of the
Great Lakes this morning with surface extension of cold front now
pushing southward through portions of central IN/OH. Much cooler
conditions in this setup as 850mb temperatures currently range
between +4C to +6C areawide. Surface dewpoints have easily dropped
into the 40s for many areas and temperatures at daybreak are
expected to be in the lower 50s. Projected absolute vorticity charts
support another vorticity maximum, collocated with composite trough
axis, digging into the Lake Huron between 18-00z today. Northerly
gradient with legitimate cold pool aloft over Ontario results in
fresh isentropic downglide and cold advection over the area today.
Gusty well mixed northwest surface winds of 10 to 25 mph today.
Forecast soundings support high static stability in the 6.0 to 16.0
kft agl yielding dry conditions but with some boundary layer cumulus
this afternoon.

Flow trajectories rapidly evolve to anticylonic tonight as strong
surface high pressure builds into Wisconsin. Main narrative tonight
is very chill nightitme temperatures with the potential for some
areas outside of the Detroit urban heat island to dip into the 40s.
Moderating and warming airmass between 4.0 and 8.0 kft agl will dry
out any lingering low-mid relative humidity for the daytime
Thursday. Very comfortable weather will exist Thu with temperatures
in the upper 70s and dewpoints in the lower 50s. Progressively
warmer Friday and Sunday with incremental increases in surface
humidity. Latest indications are surface ridge axis will continue
to hold through Southeast Michigan.

Jet exit region with anticyclonically wave break pushes into Lower
Michigan for Sunday. Models suggest shortwave energy cascading in
vicinity of the Southeast Michigan with return of warm advection.
Persistent northwest flow could lead to a more active period early
next week with regards to precipitation. Current forecasts suggest
highs in the 80s early next week.

&&

.MARINE...

High pressure moves into the area after our cold front has fully
passed the Great Lakes region, resulting in some dry weather, and
strong cold air advection that will encompass the area for the next
couple of days. Winds will be relatively gusty and coming out of the
northwest through today then subsiding on Thursday. Small Craft
Advisories remain in effect for near shore areas of Lake Huron
around the thumb and Saginaw Bay. Beach Hazard Statements are in
effect around the thumb throughout today as well. Calmer conditions
continue for the rest of the week.

&&

.PREV DISCUSSION...
Issued at 1155 PM EDT Tue Jul 21 2026

AVIATION...

Passage of the cold front earlier this evening leaves dry weather
over Lower Mi tonight and turns the forecast toward cloud trends for
the late night and morning. Evening observations show borderline
MVFR/VFR stratus expanding rapidly southward across the area in the
cool and dry air advection post front. The dry component is
impressive as surface Td drops rapidly into the 40s, which is
beginning to reflect in upstream ceiling trends more up into low end
VFR. The inbound dry air, combined with downslope into the Saginaw
Valley on steady NW low level wind, suggests MVFR ends up more of
tempo condition through the initial stage of daytime heating early to
mid morning. Continued cool NW flow gusting near 20 knots then
quickly mixes the remaining clouds into scattered cumulus and
eventually a scattered to broken mid cloud layer by late afternoon
into Wednesday evening.

D21/DTW Convection... Thunderstorms are not in the forecast late
tonight through Wednesday and Wednesday night.

DTW THRESHOLD PROBABILITIES...

* High for ceiling 5000 ft or less late tonight and early Wednesday
morning. Low Wednesday afternoon and evening.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through this evening for MIZ049.

Lake Huron...Small Craft Advisory until 10 PM EDT this evening for LHZ421-
441>443.

Small Craft Advisory until 4 PM EDT this afternoon for LHZ422.

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

$$

DISCUSSION...CB
MARINE.......TO/MV
AVIATION.....BT


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