Area Forecast Discussion Issued by NWS Detroit/Pontiac, MI
000
FXUS63 KDTX 170945
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
545 AM EDT Sun Mar 17 2024
.KEY MESSAGES...
- Temperatures slightly below normal expected today and tomorrow with
chances for flurries/light snow showers.
- Reinforcing shot of arctic air for Wednesday and Thursday.
&&
.AVIATION...
Cold northwest winds will persist through tomorrow, with the
moisture flux from the Great Lakes likely maintaining mostly cloudy
skies/VFR ceilings through the period. Isolated-scattered snow
showers are also expected, especially during the afternoon hours
across FNT/PTK, and a brief dip into IFR visibility likely, along
with cigs approaching MVFR. Diurnal mixing depths should allow for
wind gusts of 25 knots as well. Winds lose the gustiness tonight,
but likely hold aoa 10 knots, which will promote Lake Michigan
clouds and moisture expanding east as surface trough drops south,
with borderline VFR/MVFR cigs and additional light snow showers in
play.
For DTW...Ceilings likely flirting with the 5000 foot level through
most of today, with any snow flurry/snow shower activity allowing
for cigs to dip under 5000 feet.
.DTW THRESHOLD PROBABILITIES...
* Moderate in ceilings aob 5000 feet through the TAF period.
* Meduim for precip type being snow today, high tonight and Monday.
&&
.PREV DISCUSSION...
Issued at 414 AM EDT Sun Mar 17 2024
DISCUSSION...
The cold front cleared Michigan late last evening with cold west-
northwest flow taking over the state. This marks the beginning of a
pattern shift to slightly below climatological normals with regards
to temperatures for a couple days. Temperatures at 850 mb will fall
into the -9C to -11C range by this afternoon supporting highs in the
upper 30s to low 40s. The cold airmass with the longwave upper trough
over the Great Lakes will be sufficient enough support scattered
flurries and light snow shower activity today. In addition, 0-3 km
lapse rates on the order 7-8 C/km will also help boost daytime snow
shower activity. Moisture will be lacking with this set up with
models offering very light QPF today. Forecast soundings show a
favorable cloud bearing layer within the DGZ and supersaturation with
respect to ice that adds confidence to flurry/light snow shower
activity. Similar story for Monday as troughing and cold airmass
center over the Great Lakes, though flurry activity may not be quite
as widespread. Expecting any accumulation to be on the order of a
dusting to possibly a couple tenths through Monday. Overnight lows
both tonight and Monday night fall into the mid 20s.
A quick short wave trough embedded within the upper level northwest
flow will swing across the Great Lakes Monday night into Tuesday
afternoon. Best forcing is focused in northern portions of the CWA
across the Thumb region. QPF continues to lack with this system.
Could again see some minor accumulations from snow shower activity
streaming from northern lower Michigan into the Thumb. A notch of
warmer air will graze Lower Michigan on Tuesday offering potential
to see daytime highs in the 40s towards the Ohio border.
The aforementioned shortwave trough on Tuesday will move east with a
reinforcing shot of arctic air arriving in its wake for Wednesday
and Thursday. Temperatures at 850 mb are forecast to approach -20C
by Thursday morning. High temperatures mostly in the 30s look likely
during this time. Shortwave energy with a northwest to southeast
oriented jet stream over the region will bring potential for another
round of lake effect showers streaming into southeast Michigan.
MARINE...
The strong low now entering southern Quebec may be slowly weakening
but it is part of a larger upper level trough which will keep a cool
airmass over the region the next few days leading to unstable
conditions. Additionally, this low will pull it`s second cold front
down through the region Sunday night bringing moderate northwest
winds but the cold advection will lead to a ramp up in wave heights
so a new round of Small Craft Advisories will be issued for Saginaw
Bay and the tip of the Thumb to account for this. We`ll watch wind
direction in the next 24 hours to see if they go more northerly
which would bring the higher waves into the nearshore zones along
the eastern Thumb from Harbor Beach to Port Huron.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 4 PM this afternoon to 4 PM EDT Monday
for LHZ421-422-441.
Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&
$$
AVIATION.....SF
DISCUSSION...AA
MARINE.......AA
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