754
FXUS63 KGRR 281957
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
257 PM EST Sun Dec 28 2025
.KEY MESSAGES...
- Snow showers with significant winds and blowing snow tonight-Mon
- Additional chances for snow showers Tue and Wed and colder
- Moderating temperatures and mostly quiet late week
&&
.DISCUSSION...
Issued at 257 PM EST Sun Dec 28 2025
- Snow showers with significant winds and blowing snow tonight-Mon
The latest suite of data continues to justify well the headlines
that were issued earlier.
We remain in the warm air advection precipitation ahead of the sfc
low that is just SW of Chicago at 2 pm EST/19z. So far, lightning
has been been observed as far north as I-94. The best chance of
lightning looks to be over the next few hours, before the elevated
instability moves out by mid evening as the sfc low moves NE of the
area.
We see the rainfall diminish quite a bit this evening as the dry
slot moves over much of the area as the entire system occludes. A
few showers will remain, but the heavier rain will be done. Then we
will see precipitation rates pick up with the approach of the wrap
around cold conveyor that slams in across the area just prior to
daybreak. This will change the rain to snow, and bring some light
accumulations to the entire area. Temperatures fall, but the coldest
of the air is delayed getting in here by the lake, and the trowal.
By the time the lake effect gets going just prior to daybreak, the
mean low level flow will be mainly from the NW, favoring the NW and
SW corners of the area. Combine decent lake effect snows, and the
winds gusting up to 60 mph along the immediate lakeshore, and 50-55
just inland, this will create some dangerous traveling conditions on
Monday with blowing and drifting snow.
As you move further inland, the snow showers will not be as
widespread, and the winds a tad lighter. Impacts are still expected,
especially for the Advisory areas. By the time you get to the Mt.
Pleasant to Lansing corridor, not much additional snow will be
accumulating, and the winds will be a bigger impact, with just some
blowing and drifting expected.
The lake effect will wind down quickly then Monday night, as will
the winds. The upper wave supporting this moves out, and the jet
core and deep cold air lifts NE of the area by Monday evening. This
will allow conditions to improve steadily late Monday and Monday
night.
- Additional chances for snow showers Tue and Wed and colder
We see a short break in the better lake effect Monday night and
Tuesday morning, before an uptick in snowfall is expected to happen
Tuesday afternoon.
We will be in the flow from the NW once again, like much of December
was prior to the recent mild weather. We will see a short wave drop
in by Tuesday afternoon. This system does not have a lot of moisture
with it. However, the flow from the WSW and remaining colder air
will allow the lake to enhance the snow a bit for the WSW favored
areas into Tuesday night.
Another break in the activity occurs early Wednesday, before yet
another short wave dives in from the WNW. That short wave looks to
dive a little further south, and the low level mean flow will be
from the NNW. It seems that the southern portion of the forecast
area will see the better chance for snow showers then.
Temperatures will drop even more behind this system, with highs
likely staying in the teens on New Years Day.
- Moderating temperatures and mostly quiet late week
What we see happen the remainder of the week is heights will build a
bit, and likely keep most of the short wave activity north of the
area. This occurs as the large amplitude upper ridge builds to the
east a bit. We do not see the entire ridge move in, but enough to
push the northern branch of the upper jet far enough north away from
the area.
Precipitation chances look rather low to start the new year with
this pattern taking shape. Temperatures also will recover a bit once
the cold air on New Years Day has a chance to moderate with the
higher heights building in.
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1246 PM EST Sun Dec 28 2025
A dynamic weather event is unfolding across the region. Lightning
was noted across northern IN moving slowing north into southern
Lower. We`ve included a VCTS after 19z until 22-23z. Elsewhere
IFR/LIFR cigs vsbys will be widespread in rain/fog.
A strong cold front moves through this evening. Temperatures will
fall and winds will increase from the WNW. Lake effect snow will
also develop creating blowing/drifting with largest accumulations
closer to the lake shore. IFR vsbys in SN/BLSN will be common
overnight into Monday.
&&
.MARINE...
Issued at 210 PM EST Sun Dec 28 2025
Storm Warnings remain out for the lake for tonight into Monday, and
latest model trends continue to show corresponding wind speeds/
frequent gusts 50+ knots are expected on the backside of the system
in the cold air advection and strong pressure gradient. The peak
winds are expected Monday morning and early afternoon, before
gradually diminishing.
&&
.HYDROLOGY...
Issued at 257 PM EST Sun Dec 28 2025
We are watching the trends on the area rivers with this period of
rain coming through. At this time, we are expecting a couple of
points (Holt on Sycamore Creek and Vicksburg on Portage River) to
approach Minor Flood levels, but likely to stay just below. Runoff
is likely to freeze up later tonight as temperatures drop below
freezing, and then levels will gradually stabilize after that.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Storm Warning from 1 AM to 7 PM EST Monday for MIZ037-038-
043-044-050-056-064-071-072.
Winter Weather Advisory from 1 AM to 7 PM EST Monday for MIZ039-
040-045-051-057-058-065-066-073.
Wind Advisory from 1 AM to 7 PM EST Monday for MIZ046-052-059-
067-074.
MARINE...Storm Warning from midnight tonight to 1 AM EST Tuesday for
LMZ844>849.
&&
$$
DISCUSSION...NJJ
AVIATION...04
MARINE...NJJ
HYDROLOGY...NJJ
NWS GRR Office Area Forecast Discussion