Plymouth, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

206
FXUS63 KMPX 220510
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1110 PM CST Sat Dec 21 2024

.KEY MESSAGES...

- A light wintry mix likely Sunday night into Monday with snow
  accumulations generally less than an inch. However, an inch of
  snow is possible in west-central WI.

- A warming trend will occur this week with highs in the lower
  to mid 30s by Christmas. Upper 30s to near 40s highs possible
  by late next week.

&&

.DISCUSSION...
Issued at 207 PM CST Sat Dec 21 2024

Fittingly on the winter solstice, what little sunlight there is
available was lessened by mostly cloudy skies today.
Temperatures remained cold as highs only rose into the mid teens
to lower 20s this afternoon. They will not fall much tonight,
though, as WAA occurs ahead of an approaching mid-level trough.
Mostly cloudy skies will remain but we will warm in response
Sunday with highs in the mid 20s in central MN to lower 30s in
southern MN. The shortwave will encroach upon western MN Sunday
night, at which time, most models try to develop precip over the
southern half of MN. This precip advances east, ahead of the
trough, into WI Monday morning before exiting our CWA by around
noon. Examining GFS and NAM forecast soundings shows that at
minimum we could see freezing drizzle, as the thermal profile is
saturated from the surface to about 800 hPa within subfreezing
temperatures. Farther above, an additional layer of saturation
is evident with in the DGZ layer such that snowflakes to periods
of full snow are possible. However, between these 2 layers is a
layer of dry air such that it could limit how many snowflakes
make it to the surface. This issue currently seems most
prevalent over MN whereas over WI the profile becomes more
vertically saturated. Thus, our WI counties have a greater
chance at seeing possibly up to an inch of snow while areas west
could only see a few flakes to a dusting. But, being this will
occur Monday morning and at least some freezing drizzle seems
possible, it will have a good chance at making a potentially
hazardous commute. Keep your guard up when traveling to start
this week of Christmas.

After Monday morning, we will dry out for a few days with
temperatures gradually rising throughout the week. By Wednesday,
forecast highs are in the lower to mid 30s and should climb to the
mid 30s to near 40 by Friday. Despite these temperatures, with
multiple inches of snow on the ground across most of our area, a
majority of our CWA should see a white Christmas. Our next chance of
precipitation looks to be towards the end of the week as long-range
models show an upper level trough moving northeast through the
central CONUS. Big differences exist though between model suites in
that it causes NBM to smear 20-30% PoPs Friday through Saturday.
Currently, the  precipitation type looks to mostly be rain as
temperatures should be largely above freezing (during both the day
and night). These are just very early observations of the forecast
and uncertainty will decrease with time as we approach later next
week. In support, Climate Prediction Center does forecast us for
likely above normal temperatures and above normal precipitation the
end of December into early January.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1100 PM CST Sat Dec 21 2024

Stratus has expanded across southern MN, with the question now
being how quickly it clears out from the south. That clearing is
already past I-90, so we did speed up improvements to VFR in the
morning from previous TAFs. Winds will be southeast through much
of Sunday, but by the afternoon, a low will move into western
MN, which will result in the winds settling down toward sunset
Sunday, with winds Sunday evening swinging from the southeast
over to the northwest via the north. Also, with those northwest
winds will likely usher in another batch of low stratus.

KMSP...Stratus has moved in, but with the clearing line already
through MKT, we did move improvements up a couple of hours, but
that improvement has slowed, so there`s quite a bit of
uncertainty with how quickly it will reach MSP. For Sunday
night, models have been trending away from there being precip at
MSP, so left the TAF dry.

/OUTLOOK FOR KMSP/
MON...MVFR cigs likely. Wind NW 5-10 kts.
TUE...MVFR cigs likely. Wind S 5 kts.
WED...MVFR cigs likely. Wind SE 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...CTG
AVIATION...MPG