National Weather Service Weather Forecast Office

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KDTX 191100
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
700 AM EDT Fri Apr 19 2024

.KEY MESSAGES...

- Rain moves out this morning with mostly sunny skies returning for
the afternoon. Breezy conditions with westerly gusts of 25 to 30 mph
today.

- Cool and quiet weather this weekend with potential for some frost
to develop Sunday morning.

- Next chance of showers and thunderstorms arrives Tuesday.

&&

.AVIATION...

Pockets of MVFR to IFR will be possible the first hour of the
forecast as low level saturation remains in the wake of the weak
cold frontal passage. Efficient, steeply sloped isentropic descent
will clear skies out between 15-21Z this afternoon. Deep boundary
layer mixing is expected to result in northwest surface winds of 15
to 25 knots. Troughing and associated midlevel cooling will push
into Southeast Michigan and lead to mid cloud and saturation this
evening and overnight.

DTW THRESHOLD PROBABILITIES...

* High for ceiling aob 5000 ft through 12-14Z this morning.

&&

.PREV DISCUSSION...
Issued at 354 AM EDT Fri Apr 19 2024

DISCUSSION...

Steady rain has spread over most of SE MI this morning in response
to a mid-level wave ushering in moisture advection and ascent ahead
of a cold front. Coverage of rain is currently near its peak and
will move out to the east over the next several hours as the front
pushes through. Radar estimates and observations upstream suggest
most areas are on pace to receive a few tenths up to a half inch of
rain. Morning clouds then clear out as the wake subsidence works in,
with mostly sunny skies expected to return. Steady height falls
ensue through the rest of the day as a closed mid-level low over
Ontario expands south across the area. Cool advection sends 850mb
temps to the negative single digits by midday with a deepening, well
mixed boundary layer offering a breezy afternoon with gusts of 25 to
30 mph. Otherwise, dry and seasonable conditions with high temps in
the mid to upper 50s.

A secondary dry cold front moves through tonight, reinforcing the
cool advection through Saturday. This pattern likely prevents the
boundary layer from fully decoupling tonight and the mixing should
hold lows in the mid to upper 30s. Temps then rebound to the upper
40s to lower 50s on Saturday with similarly breezy but dry
conditions through the day. An increase in clouds is expected with
most guidance showing a shallow layer of 750-850mb moisture rotating
around the Canadian low.

Chilly conditions are expected Saturday night into Sunday morning
with weaker flow resulting from a ridge of high pressure building in
across the Ohio Valley. This looks to allow lows to settle into the
lower 30s outside of the urban footprint, so some frost may develop
Sunday morning especially if clouds clear out. Weak warm advection
and air mass modification then boost temps back into the mid 50s by
the afternoon. Shortwave ridging passing overhead on Monday leads to
another dry and mild day.

A pattern shift is taking shape for the mid-week period with the
likely arrival of an amplified northern wave. Tuesday is currently
favored for the passage of a cold front with NBM guidance offering
70+% PoPs and potential for some thunderstorms dependent on timing
and placement of the instability axis. Another shot of cooler air
works in behind this system with some concern for freezing temps as
a surface anticyclone sets up overhead Wednesday night bringing
favorable radiating conditions and potential for lows to dip into
the upper 20s Thursday morning.

MARINE...

Cold front and associated showers clear the region late this morning
ushering in cooler westerly flow as an upper trough settles over the
Great Lakes. This pattern holds fairly constant through this weekend
albeit with slight variability in wind direction ranging between
west and northwest as a series of weak disturbances embedded within
the trough slide across the northern Great Lakes/Ontario. Cooler
airmass supports modestly unstable overlake thermal profiles
maintaining more efficient mixing particularly during the daylight
hours where peak winds can be expected. Strongest winds occur over
northern Lake Huron with peak gusts in the 25-30kt range with 15-
25kt gusts instead favored over the rest of the region. Small craft
advisories are in effect for the Saginaw Bay and tip of the Thumb
nearshore waters from midday Friday through Saturday afternoon due
to these moderate winds and subsequent rougher wave action.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 1 PM this afternoon to 4 PM EDT Saturday
     for LHZ421-422-441.

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

$$

AVIATION.....CB
DISCUSSION...TF
MARINE.......KDK


You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.