Plymouth, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

757
FXUS63 KMPX 231750
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1150 AM CST Sat Nov 23 2024

.KEY MESSAGES...

- Cool and relatively quiet weather with cloudy skies for the next
 few days.

- A few snow/rain showers possible north of I-94 late Sunday
  into Monday with minimal accumulation.

&&

.DISCUSSION...
Issued at 307 AM CST Sat Nov 23 2024

Radar is showing light returns this morning amidst what is otherwise
mid level stratus, and as of yet we have not seen much in the way of
surface precipitation. Some sprinkles or flurries are possible as
this wave moves across the area today with the best chance in
western Wisconsin beginning over the next few hours, however no
accumulation is expected unless we start to see better radar returns
aloft leading into a potential seeder feeder type of band. For now,
not expecting this to come to pass as the strongest returns over the
Dakotas have largely continued to weaken as they spread into
Minnesota and eventually Wisconsin. Today will otherwise be cloudy
but quiet with high temperatures generally in the low 30s in western
Minnesota increasing to near 40 in the metro and western Wisconsin
with a weak upper level ridge sliding across the area. Sunday will
continue with more of the same cloudiness and temperatures before a
small chance for precipitation arrives generally north of I-94 with
weak snow showers over the northeastern portion of the CWA before it
moves through by midday Monday. The setup has not changed compared
to guidance over the last few days, with the stronger portion of an
upper level jet remaining too far south to give us strong upper
level support for lift, meaning we will rely on a developing system
in central Canada which looks to produce an upper level occlusion
and broad area of weak CVA as a surface low begins to form Monday
morning. Guidance has begun to align a bit better in terms of spread
with the EPS/CFS bringing a few hundredths of QPF north of the Twin
Cities with the best forcing moving through our neighboring NWS
friends at the Duluth`s coverage area covering central Minnesota to
northern Wisconsin. The main consideration is whether or not we see
a surface low developing under the upper level occlusion, as
evidenced by the differences between a few of the deterministic
global models with some such as the CAN forcing a line of
precipitation once the forcing reaches central Wisconsin by Monday
afternoon and the GFS/ECMWF ejected a weak surface low over the
Great Lakes much more quickly, resulting in a much weaker system
that produces little in the way of precipitation. For now, the best
chance for showers remains to our north through early Tuesday.

The main forecast difference to yesterday beyond the early period
system is a shortwave bringing a quick hit of showers the 2nd half
of Wednesday as temperatures slowly begin to fall towards the
holiday with northwesterly flow aloft and weak surface flow. Another
broad, spinning upper level trough is loosely agreed upon by the
longer range guidance towards next weekend, which is worth watching
for now during one of the busiest travel periods of the year but at
least right now is not expected to pose significant issues across
our area. The main consequence will continue to be a shift towards
colder temperatures by Friday with highs struggling to get out of
the teens in western MN and low 20s for the rest of us as the colder
trend continues into next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1127 AM CST Sat Nov 23 2024

Late morning satellite trends reveal that any gaps in VFR cloud
deck are quickly replaced by high clouds streaming in from the
Dakotas. We expect this theme to continue through the afternoon,
with cloud bases generally above 10k feet. Uncertainty grows
after 6z, as guidance varies on the eventual arrival of MVFR or
lower stratus. Latest RAP soundings are very aggressive, suggesting
that all sites will flirt with MVFR cigs by daybreak Sunday. We
have opted to trend the TAFs a little slower, which leans towards
the blended HREF solution. In doing this, MVFR ceilings arrive
prior to daybreak at AXN/RWF, spreading east towards STC/MKT by
13/14z, and then reaching MSP by midday. RNH/EAU aim to remain
VFR through the 18z period. Despite the timing challenges associated
with the arrival of low ceilings, we have high confidence that
MVFR (or lower) conditions will prevail all the way into Monday
morning. The mention of light wintry precipitation may need to
be added in forthcoming TAFs. Winds turn easterly between 5-15
kts Sunday.

KMSP...No additional concerns outside of the uncertainty
associated with the arrival of MVFR ceilings discussed above.

/OUTLOOK FOR KMSP/
MON...VFR/MVFR, chc -RASN early. Wind NW 10-15G25 kts.
TUE...VFR. Wind NW 5-10 kts.
WED...VFR. Wind E 5-10 kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...Strus