023
FXUS63 KGRR 081803
AFDGRR

Area Forecast Discussion
National Weather Service Grand Rapids MI
103 PM EST Wed Jan 8 2025

.KEY MESSAGES...

- Light snow today, Friday, and Sunday

- Continued near to below normal temperatures

&&

.UPDATE...
Issued at 1154 AM EST Wed Jan 8 2025

Lake effect snow is ongoing this morning in a north-northwest
flow regime over Lake Michigan. Snowfall so far has been on the
order of trace amounts up through 3 inches. More consistent
banding occurred overnight across Van Buren County where snowfall
totals were near 3 inches. Since daybreak a consistent band has
not really presented itself but that may change this afternoon.

A shortwave can be seen in water vapor imagery diving southeast
out of the Western U.P. and Northern Wisconsin. We can already see
some light radar returns with this shortwave sliding in from the
northwest. The shortwave will provide both lift and moisture to an
already unstable lake effect snow environment, so we do expect an
uptick in both coverage and intensity this afternoon and early
evening. The next 6 to 12 hours will be the duration of this
event with snow tapering off overnight. Snowfall accumulations
going forward are expected to be in the 1-3 inch range this
afternoon and evening with some isolated 4 inch amounts.

At this point web cameras along the lakeshore, travel speed
websites and our forecast indicates a headline is not needed. We
will obviously be monitoring conditions this afternoon to see how
conditions transpire, but we feel this is likely a sub advisory
event for the bulk of the area.

&&

.DISCUSSION...
Issued at 326 AM EST Wed Jan 8 2025

- Light snow today, Friday, and Sunday

A large latitudinal trough is dropping south across the Great
Lakes. An with it comes a shot of colder air...h8 temps around
-16c...and a short wave that will impact the cwa this afternoon.
 Current radar shows light snow showers mainly hugging the lake
 shore. However, as winds back the northwest later today and the
 short wave moves south over Lake MI, we`ll see snow showers
 increase in both coverage and intensity as lift within the DGZ
 develops. We don`t anticipate large accumulations, but 1-3 inches
 with locally higher amounts along the lake shore seem likely.
 HREF probabilities of more than 2 inches are 80% along the lake
 shore and 70% greater than 3 inches. Probabilities drop off
 quickly east of US-131 where a dusting to an inch are possible
 through tonight before the snow diminishes toward Thursday
 morning.

Light snow is expected Friday as a northern stream trough absorbs
a southern stream shortwave and moves across the Great Lakes. The
bulk of the moisture will remain south of the Ohio River, but some
will be able to advect north into Lower MI. A short wave dropping
south from Canada within this long wave trough will help light
snow develop Friday morning. We`ll be nickeled and dimed again
with 1-3 inches across the cwa. Light snow will wind down
Saturday morning.

A clipper will move through Lower MI Sunday into Monday. A surge
of arctic air will accompany this clipper dropping h8 temps down
to -18c by Monday morning. Initially, we`ll see light synoptic
snow develop followed by lake effect. Northwest boundary layer
winds will result in widespread lake effect snow across the cwa
before it winds down Tuesday morning. Several inches of
accumulation are possible with this system.

- Continued near to below normal temperatures

Highs in mid to upper 20s are expected through the weekend before
falling to around 20 next Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1 PM EST Wed Jan 8 2025

Lake effect snow bands will dominate the TAF concerns through 06Z.
Expect periods of IFR vsbys and cigs due to snowfall at MKG and
AZO until 03Z. Short range models have the snow bands moving
inland and increasing between 20Z and 03Z. This should bring
predominately MVFR cigs with periods of IFR to GRR, AZO, BTL and
MKG. LAN and JXN could see some MVFR cigs and vsbys between 00Z
and 06Z but are on the very edge of these bands.
 Conditions will improve between 03Z and 09Z with VFR developing
by 12Z. VFR will then dominate through tomorrow.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.

&&

$$

UPDATE...Duke
DISCUSSION...04
AVIATION...Ceru