Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 231729
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
129 PM EDT Sat Mar 23 2024

.KEY MESSAGES...

- Dry weather with below average temperatures will continue to mark
conditions through the remainder of the weekend.

- A more significant warming trend will emerge early next week.
Breezy conditions will develop during this time.

- Rain potential increases Monday night continues through Tuesday.

&&

.AVIATION...

Diurnal heating has and will continue to expand strato cu between 4-
5 kft across SE MI through the afternoon and early evening hours.
Cloud coverage will scatter and clear by the late evening given the
loss of sunshine. Sporadic wind gusts to 20 knots will be possible
through the afternoon. Some lingering low-level clouds will also be
possible across KMBS beyond the evening hours given some low-level
convergence with an added boost of moisture from the Saginaw Bay
under northeast flow, but otherwise generally clear conditions are
expected overnight.

.DTW THRESHOLD PROBABILITIES...

* Moderate in ceilings aob 5000 feet today.

&&

.PREV DISCUSSION...
Issued at 305 AM EDT Sat Mar 23 2024

DISCUSSION...

Meaningful snow activity ended overnight for all of SE MI as
Friday`s shortwave is now rapidly tracking toward the eastern
seaboard to eventually merge into a large coastal system. A
secondary cold front marking the lead edge of high pressure is
dropping through the central Great Lakes early this morning with
radar obs depicting areas of light snow showers/flurries over
northern lower MI in advance. Radar trends show this activity
diminishing as it pushes further south due to losing upper support
from the trough currently over the northern Great Lakes. Snow
showers are managing to maintain better coherency over Lake Huron
thanks to additional moisture flux however. Its this activity that
will offer a brief window this morning for areas in the far
northern/eastern Thumb to see a light snow shower as northerly flow
attempts to draw these showers in from the open waters. Very
minimal, if any, accumulations expected should snow encroach from
over Lake Huron. Otherwise, drier weather takes hold today as the
aforementioned surface high pressure dropping out of the Canadian
Prairie builds across the central Great Lakes. With the high center
holding to our west, northwesterly low level flow reinforces the
thermal troughing already in place with CAA lowering local 850mb
temps into the low negative teens (C) supporting highs only in the
30s today.

Increasing mid-level subsidence and a drier Canadian airmass
gradually erodes near-surface moisture over the course of the day as
diurnal mixing heights within this advective regime increase to 4-
5kft. While forecast soundings suggest this mixing won`t be
sufficient to fully clear low level moisture/lingering clouds, it
should allow for at least a mix of sun and cloud today. Ridge axis
drifts overhead tonight further clearing clouds as well as lowering
winds to 5mph or less allowing for more efficient radiative cooling.
Overnight lows expected to fall well into the lower 20s with some
upper teens in the more rural areas of the CWA. Similar setup for
Sunday though with sunnier skies, temperatures rise into the upper
30s to low 40s.

Major pattern shift begins Monday as a potent mid-upper Pacific
trough ejects out of the inter-mountain west and into the Plains.
Resulting rapid cyclogensis leads to the generation of a warm front
over the Ohio/mid-Mississippi river valleys that is quickly forced
north into lower MI over the course of the day. Significant WAA
follows with 850mb temps rising from around -10C Sunday night to +8-
10C Monday evening. Much warmer though breezy days can be expected
for both Monday and Tuesday as a result. Rain chances looking to
arrive late Monday night-early Tuesday as the Plains low lifts into
the upper Midwest/NW Ontario. Rain chances continue through the day
Tuesday as Gulf moisture is drawn nearly due north into the Great
Lakes in advance of the attendant cold front that is progged to
stretch from northern WI to LA gulf coast. Because of this
orientation, influence of convective activity across the southern
CONUS likely will play a large role in determining how much
moisture, and subsequent QPF, is able to lift into southern lower MI.

MARINE...

High pressure builds in today with organized northerly flow ushering
in a colder airmass that persists through the weekend. The onshore
flow component creates elevated wave heights that exceed 5 feet,
thus Small Craft Advisories are in effect from Outer Saginaw Bay to
Port Huron for the better part of today and tonight. Quieter
conditions prevail Sunday as the high pressure center drifts
overhead, with winds veering to the east and eventually southeast by
Sunday night. The next low pressure system arrives early next week,
bringing widespread rain to the Great Lakes and an increase in
southeast winds. The southeast direction and warm incoming airmass
will both work against widespread gale potential, though will still
monitor gust potential as an energetic low level jet will move in
aloft.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until midnight EDT tonight for LHZ421-441>443.

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

$$

AVIATION.....AM
DISCUSSION...KDK
MARINE.......MV


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