210
FXUS63 KGRR 050243
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
943 PM EST Wed Dec 4 2024

.KEY MESSAGES...

- Hazardous Travel tonight through Thursday

- Rain/Thaw early next week

&&

.UPDATE...
Issued at 943 PM EST Wed Dec 4 2024

It has certainly been a crazy evening weather-wise as impressive
squall associated with the Arctic front pressed quickly through
the area, producing wind gusts in excess of 50 mph and scattered
to numerous power outages along the lakeshore. Winds were not
quite as strong farther inland; 35 to 45 mph gusts were more
common with only isolated outages as the line passed through.

A few thunderstorms also occurred and produced areas of 1/4 mile
visibilities in heavy snow. Most main interstates/highways are
currently red or orange on the MDOT MiDrive map suggesting travel
is being severely hampered by the ongoing widespread snow, wind
and falling temps.

No changes to the warning/advisories although after Midnight most
of the accumulating snow will become restricted to areas
near/west of Hwy 131 as the synoptic portion of the event winds
down and we transition to pure NW flow lake effect. Wind gusts
will lower a bit but will still gust to 35 mph; highest along the
lakeshore where blowing snow and occasional whiteouts will be more
prevalent than farther inland. The Thursday morning commute will
be a tricky one with temps only around 20 and slick/snow covered
roads.


&&

.DISCUSSION...
Issued at 337 PM EST Wed Dec 4 2024

- Hazardous Travel tonight through Thursday

The cold front is currently advancing towards Lower Michigan with
a burst of snow along the front in Wisconsin and snow showers
behind it across Minnesota. These should be given an added
convective boost by heat/moisture flux from Lake Michigan. So we
expect heavy snow squalls combining with strong winds to cause
whiteouts along and behind the front.

There is also the potential for residual moisture to freeze on
roads as temperatures fall from the lower 30s to the lower 20s
tonight.

Flow goes northwest behind the front and the hi res models show a
dominant LES band affecting western Lower Michigan through
Thursday, slowly wavering across the area currently in the Winter
Storm Warning. Some areas that see banding persist the longest
could see snow totals near 10 inches by Thursday night.

The thermal trough axis moves east by Friday with snow showers
winding down and fair weather arriving for the weekend.

- Rain/Thaw early next week

Return flow sets up on Sunday as cold sfc high pressure moves
east with thawing temperatures persisting into Monday. Southern
stream low with plenty of Gulf moisture moves northeast, but
model trends today suggest the bulk of rains stays off to the
southeast of the forecast area. Current likely POPs on Monday will
remain for now. After the low goes by, colder air filters in on
the backside for Tuesday and snow showers are possible through the
middle of the week under upper troughing and cyclonic flow.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 640 PM EST Wed Dec 4 2024

Snow squalls associated with the Arctic front pushing through
over the next 3-4 hours, dropping the vsbys to 3/4 mile or less
and producing wind gusts as high as 35-40 kts at most terminals. A
rumble of thunder also cannot be ruled out as there have been some
lightning strikes recently noted over the lake (currently offshore
of Holland).

Overnight the snow showers will transition to pure lake effect
bands behind the front and with NW winds that means MKG and AZO
will be impacted the most by vsby reductions while places east of
there see less frequent/significant vsby reductions in snow.
Winds will continue to gust to 30 kts into Thursday.

&&

.MARINE...
Issued at 337 PM EST Wed Dec 4 2024

No changes to the Gale Warning. Arctic front comes through tonight
with some gusts at storm force. West gales continue overnight with
some coastal flooding possible along beaches from South Haven to
Holland and even some flooding along rivers near Lake Michigan.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Storm Warning until 1 AM EST Friday for MIZ037>039-
     043>045-050-056-057-064-065-071>073.
     Winter Weather Advisory until 1 AM EST Friday for MIZ040-046-051-
     052-058-059-066-067-074.
MARINE...Gale Warning until 1 PM EST Thursday for LMZ844>849.

&&

$$

UPDATE...Meade
DISCUSSION...Ostuno
AVIATION...Meade
MARINE...Ostuno