Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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000
FXUS63 KDTX 250719
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
319 AM EDT Mon Mar 25 2024

.KEY MESSAGES...

- Widespread rain will affect the area late tonight and Tuesday
morning.

- Showers and scattered thunderstorms are possible late Tuesday
afternoon and evening. Some storms may produce strong winds.

- It will be windy on Tuesday, with gusts over 35 MPH possible.

- Colder weather returns Wednesday.

&&

.DISCUSSION...

Long wave trough amplification across the central US today will be
driving mid level height rises across the eastern Great Lakes. At
the sfc, a ridge of high pressure will remain anchored along the
eastern seaboard. Deep layer south flow will increase across the
Ohio Valley and Great Lakes today. There will be enough influence
from the downstream anticyclone that despite the increasing warm air
advection, ample deep layer dry air will ensure a dry forecast today
with just some passing mid and high level clouds. The strength of
the low level wind fields will be efficient in driving warm air into
Se Mi today. 925mb temps are forecast to warm from -4 Deg C last
evening to +8 to +10 Deg C by late this afternoon. After the cold
weekend, this will result in a much warmer day today. The
southeasterly component to the sfc winds will add some influence
from the Great Lakes, which may temper the response a bit and
support highs mainly in the 50s.

An upper wave will lift into the Upper Mississippi Valley tonight
with the associated sfc low forecast to track into western
Wisconsin. This will drive the associated deep layer moist plume
associated with the warm conveyor eastward across Southeast Michigan
between 09Z and 15Z Tuesday. Isentropic analysis shows extremely
efficient moisture transport within the warm conveyor, with model
soundings indicating precipitable water rising to an inch across Se
Mi. The 296K surface indicates Se Mi along the nose of a 70-85 kt
low level jet, which will place strong theta e convergence across Se
Mi. This in tandem with good upper level difluent flow will support
an axis of widespread rain. The moist axis is shown to be fairly
progressive as the wind fields in the low level jet are shown to
veer during the morning, focusing the better convergence east. The
mid level dry slot will also move across Se Mi by late morning,
ending the widespread rain and possibly supporting just some drizzle
into the afternoon. The low level wind fields through the day
Tuesday will remain quite strong (40-50 knots at 2-3k feet).
Boundary layer stability concerns suggest holding winds below
advisory criteria attm.

Trends within the 00Z model suite are stronger with a trailing mid
level short wave forecast to rotate across nrn Illinois Tues
afternoon and into northern Michigan Tues night, with a strong
northern stream trough dropping into the Dakotas forcing an
increasingly progressive pattern. This wave will help drive a cold
front across Se Mi late Tues afternoon/evening. A narrow axis of
surface based instability is forecast along the lead edge of this
front, forecast to wane as it moves into Se Mi due to loss in
daytime heating. Given the strong shear profiles, any amount of
surface based convection would pose a severe weather risk. Based on
the 00Z model suite forecast SB Cape parameters, the SPC Day2
outlook has a marginal risk of severe weather from Indiana into SW
Lower Mi, right into the western sections of the DTX CWA. The
aforementioned northern stream wave is then forecast to evolve into
a closed circulation across the northern lakes region by Wednesday,
which will support seasonally cool conditions across the forecast
area through the end of the work week.

&&

.MARINE...

Southeasterly flow strengthens this morning ahead of the next low
pressure system, with Small Craft Advisories in effect for nearly
all Lake Huron nearshores due to elevated wave action. Influx of
warm and stable air sets up a strong inversion which keeps gusts
comfortably below 30 knots through today.

A strong low level jet (winds at 1 kft agl of 55-60 knots) surges in
early Tuesday morning, with a band of rain and cooler air on its
nose. The cooler air works to weaken the inversion, allowing enough
shallow mixing for gales across central and northern Lake Huron.
Given the 00Z model guidance, an upgrade to a gale warning for
tonight and Tuesday will in place for Lake Huron between Port
Sanilac and Presque Isle. A cold front pivots through Tuesday night
followed by high pressure mid-week, bringing quieter marine weather
to the Great Lakes.

&&

.HYDROLOGY...

A storm system will impact the Upper Midwest and Great Lakes region
for the next couple of days. A pair of frontal boundaries associated
with this system will produce two distinct rounds of rain across
Southeast Michigan. The first will occur mainly between 4 AM and 10
AM Tuesday, with a quarter to half inch of rain possible. The next
will occur late Tuesday afternoon and evening. This second round
will be more convective but will be faster moving. So additional
rainfall amounts will be under a quarter inch.

&&

.PREV DISCUSSION...
Issued at 1153 PM EDT Sun Mar 24 2024

AVIATION...

High clouds thin out over Lower Mi late tonight until reloading from
the west during the morning. The result is VFR above 5000 feet that
continues through the day as a large low pressure system strengthens
in the central Plains. Precipitation is held to the west due to the
slow movement of the system and by low level dry air dominating on
increasing SE wind. The wind increases to gusts around 25 knots by
mid afternoon until stabilizing toward evening which then sets up a
favorable LLWS scenario through Monday night.

DTW THRESHOLD PROBABILITIES...

* None.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Gale Warning from midnight tonight to 10 PM EDT Tuesday for LHZ362-
     363-421-422-441-442-462-463.

     Small Craft Advisory until midnight EDT tonight for LHZ421-441-442.

     Small Craft Advisory until 10 PM EDT Tuesday for LHZ443.

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

$$

DISCUSSION...SC
MARINE.......MV
HYDROLOGY....SC
AVIATION.....BT


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