509
FXUS63 KDTX 030720
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
320 AM EDT Fri May 3 2024

.KEY MESSAGES...

- Numerous showers hang around today, with a chance of non-severe
thunderstorms.

- High pressure fills in briefly on Saturday offering drier weather
ahead of the next weak cold front that tracks through SE Michigan
early Sunday morning.

- Seasonably warm temperatures expected through early next week with
high temperatures in the low to mid 70s.

&&

.DISCUSSION...

Large upper level low/trough over Central North American early this
morning, with the center along the northern Minnesota border. The
500 MB low (~540 DAM) will track off to the northeast, reaching
Hudson Bay Saturday morning.

Deep southwest flow will maintain above normal temperatures over
southeast Michigan right through the weekend. Moisture advection has
peaked out with the broad 850-700 MB Theta-E ridge axis extending
north, through the Central Great Lakes. Still looks like lingering
showers around today with possible thunderstorms as a ribbon of
upper level PV approaches from the southwest.  Severe weather not
expected with weak mid level lapse rates and MLcapes under 750 J/kg.

Height rises/surface ridging expected on Saturday, leading to mainly
dry conditions during the day. Low clouds trapped underneath
subsidence inversion, with perhaps a bit of drizzle/very light
showers toward the southern Michigan border where the higher dew pts
reside. Weak height falls/cold front then on track to move through
through Saturday night, worthy of chance pops, despite the bulk of
the forcing over northern Great Lakes.

Western confluent upper level flow Sunday preceding an upper level
ridge axis arriving early next week, supporting at least a 48 hour
window of dry and pleasant weather.

&&

.MARINE...

A low pressure system will then track through the northern Great
Lakes today pulling the warm front up through the region early in
the day. This will allow winds to flip around to the south-southwest
which will bring in a warmer airmass, helping to keep gusts down.
Scattered showers and thunderstorms will focus on this morning warm
frontal passage and may persist into the afternoon. Showers and
thunderstorms then increase coverage once again in the evening as
the cold front gets pulled through the region. Brief area of high
pressure brings quieter weather on Saturday. Winds will flip around
to the northeast behind the cold front tonight, but the area of high
pressure will keep winds below 20 knots. Southerly winds will
redevelop Saturday night ahead of the next cold front that will
sweep through Sunday, but will turn northwesterly behind the front
Sunday afternoon.

&&

.PREV DISCUSSION...
Issued at 1157 PM EDT Thu May 2 2024

AVIATION...

Clusters of elevated showers and isolated thunderstorms continue
over SE Mi late tonight through the morning. Ongoing activity along
and north of the warm front combines with additional showers and
storms moving in from the IL/southern Lake Mi area as the front
moves very slowly from northern IN and western OH into southern
Lower Mi. Earlier nocturnal timing of rainfall contributes to
expansion of MVFR ceiling in and around the warm front as it moves
northward and eastward during the morning followed by a similar
cloud field quickly followed by the associated cold front. The cold
front is set to move through SE Mi during afternoon also providing a
focus for showers and scattered storms until exiting eastward by
Friday evening.

For DTW/D21 Convection... An isolated and elevated thunderstorm
occurs late tonight among scattered to numerous showers across SE
Mi. The storms will have ordinary intensity through the morning
until daytime instability builds up in the afternoon. A renewed time
window for thunderstorms then occurs mid to late afternoon as a cold
front moves through the region. Scattered coverage occurs among
numerous showers along the front, although strong to severe storms
are not expected.

DTW THRESHOLD PROBABILITIES...

* Low for thunderstorms tonight and Friday.

* Moderate for ceiling 5000 ft or less Friday.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...None.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

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


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