000 FXUS63 KGRR 060824 AFDGRR  Area Forecast Discussion National Weather
Service Grand Rapids MI 324 AM EST Wed Dec 6 2023  LATEST UPDATE... Short
Term/Long Term/Marine  .SHORT TERM...(Today through Thursday) Issued at 324
AM EST Wed Dec 6 2023  A few light snow showers and flurries will continue
to develop through the morning with h8 temps down around -8 C yielding
delta t/s in the middle teens. Precipitation will taper off toward midday
as deeper moisture decreases and h8 temps begin to moderate.  Dry wx is
expected for most of our area tonight. A mid to upper level disturbance
passing by well to the north to ne of our area may bring just a few light
mixed light rain/light snow showers to our ne fcst area. Milder and dry wx
is forecast for Thursday. A fair amount of sun in conjunction with
increasing sw flow waa will help to boost max temps well into the 40s. 
.LONG TERM...(Thursday night through Tuesday) Issued at 324 AM EST Wed Dec
6 2023  The latest 00Z deterministic runs of the ECMWF/GFS/Canadian have
all changed their tune quite a bit as far as the late weekend weather goes.
The longwave trough which digs over the center of the nation is now shown
to be a bit more progressive and less amplified so the sfc frontal zone
just drifts east through Michigan with no notable sfc low developing along
it.  This scenario would mean a round of rain showers Friday night through
Saturday night ahead/along of the front, followed by some light lake effect
snow showers in the cold advection behind the front Sunday into Monday.
Ensemble 50th percentile QPF amounts have lowered, as well as the threat of
stronger winds.  That said there are still a few (minority) ensembles
members which support the idea of a decent sfc low developing along the
baroclinic zone although that number is shrinking in the new 00Z data. A
few members are also still putting down a stripe of synoptic snow through
the area but it should be noted that the EC ENS 90th percentile snow
amounts have lowered considerably and the prob of >6" is now less than 10
percent.  So while overall fcst confidence still remains relatively low for
later in the weekend, the risk of any higher impact weather is definitely
decreasing in the new 00Z 12/6 data.  Otherwise confidence is high
regarding the unseasonable warmth preceding the frontal passage, with temps
Friday expected to be in the 50s and even a decent potential for sunshine.
Similar highs are possible on Saturday as well, especially over ern
sections, depending on frontal timing and shower coverage. 

NWS GRR Office Area Forecast Discussion