224
FXUS63 KGRR 081122
AFDGRR
Area Forecast Discussion
National Weather Service Grand Rapids MI
622 AM EST Sun Feb 8 2026
.KEY MESSAGES...
- Snow passes mainly southwest of forecast area this morning
- Snow passes mainly north of area Monday night
- Increasing precipitation chances by this weekend
&&
.DISCUSSION...
Issued at 310 AM EST Sun Feb 8 2026
- Snow passes mainly southwest of forecast area this morning
The SPC mesoanalysis 800-750mb EPVg display nicely tells the story
regarding the northwest-southeast oriented FGEN snow band passing
east of Chicago at this time. There is a sharp reflectivity gradient
on the west side of this band, indicating good coupling between the
ascending branch of the FGEN response and the overlying layer of
negative EPV (conditional instability). The consequent narrow,
sharply focused snow band will give far southwest Lower MI a
glancing blow of little to no accumulations. For the rest of the
forecast area, accumulating snow is looking far less likely due to
subsidence contributed from both shortwave ridging aloft (per water
vapor imagery) and mesoscale subsidence poleward of the FGEN band.
- Snow passes mainly north of area Monday night
As noted previously, a northern stream shortwave trough and clipper
tracks north of Lower Michigan Monday into Tuesday. Model guidance
indicates low chances for accumulating snow to reach as far south as
our northern forecast area. For example, regarding probabilities of
exceeding a tenth of an inch of accumulation, latest REFS guidance
indicates a 50 percent chance of this happening in Clare County (our
far northeast forecast area), whereas 08/01Z NBM guidance gives just
a 10 percent chance of this happening north of US-10.
Tuesday will be the warmest day in quite a while prior to colder air
filtering in behind the exiting clipper. High temperatures farther
south towards I-94 could make a run at 40 degrees.
- Increasing precipitation chances by this weekend
It seems likely that dry conditions will prevail in the Tuesday to
Thursday timeframe with surface high pressure centered in the area.
Precipitation chances nudge upward beginning late Thursday/Friday
and continue into the weekend. This uptick in precipitation
chances is partly associated with the typical growing uncertainty
that occurs at longer forecast projection times and this will
usually trend the forecast towards climatological PoPs.
The other reason behind this uptick in PoPs is that we do see a
signal for longwave troughing in the west and downstream ridging
somewhere in the mid-section of the CONUS by the weekend. Cluster
analysis shows growing agreement with this solution among the
medium range ensembles. The main questions are amplitude and phase
speed of this wave. Although precipitation details are a bit
tough to iron out at this point, what`s more certain is a warmer
pattern due to upper ridging centered near or perhaps just east of
our longitude, accompanied by deep southwesterly flow. Some
guidance like the AI GEFS even suggests much of the southern
forecast area could get into the 40s by Sunday. This should
provide a clue that precipitation type could be more of a
rain/snow mix, with a non-zero probability of some freezing rain
as well.
&&
.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 622 AM EST Sun Feb 8 2026
The probability for IFR conditions being met at any of the
terminals through the period is very low...around 5 percent.
Based on radar trends, we scaled back on mention of snow, leaving
just a brief PROB30 for Kalamazoo early this morning.
MKG ceilings did briefly get down to 3000 feet AGL earlier this
morning, but don`t expect MVFR ceilings to be a concern today
across southwest Lower MI. Ceilings will most likely stay above
6000 ft AGL.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
DISCUSSION...TJT
AVIATION...TJT
NWS GRR Office Area Forecast Discussion
