054
FXUS63 KMPX 090827
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
227 AM CST Sat Nov 9 2024

.KEY MESSAGES...

- Periods of showers and drizzle this afternoon through Sunday
  morning.

- Consistent near to slightly above normal temperatures (upper
  40s, low 50s) for the next week.

- Next potential system arrives Wednesday.

&&

.DISCUSSION...
Issued at 226 AM CST Sat Nov 9 2024

The upper low that has been stuck over NM/CO the past couple of days
is finally on the move with a broad shield of rain out ahead of the
systems dry slot from the KS/MO border, arcing back up into southern
SoDak. Though this may look promising for us to see a soaking rain
today, a quick look at last nights sounding shows our problem, a
very dry antecedent airmass that this system must displace. RH
time/height cross-sections show that the process of moistening this
dry airmass will take place in pieces, with the upper and mid levels
slowly moistening during the day today. The low levels moisten
overnight, though that will coincide with the arrival of the dry
slot drying out the mid and upper levels. The net result is that
we`re expecting to see an arcing band of showers develop ahead of
the dry slot across southern MN this afternoon that will move
northeast through the day, moving into western WI this evening.
Behind this initial band, if we see any additional precip it will
come in the form of drizzle. Late tonight, the upper low will move
across northern IA on its way to Green Bay by Sunday afternoon. This
will bring back another shower threat late tonight through Sunday
morning across south central and southeast MN given their proximity
to the upper low and its rich pool of vorticity. When all is said
and done, most areas are expected to see around a tenth of an inch
of rain, with amounts closer to a quarter inch down along the I-90
corridor where they could double dip with the rain out ahead of the
dry slot this afternoon and then another round tonight with the
upper low. Given all of the cloud cover expected this weekend, we`ll
see fairly constant temperatures in the 40s to low 50s, so no wintry
precipitation will occur.

Sunday night we`ll see a secondary cold front sweep across the area
from a surface low going across northwest Ontario. This will be a
dry front, by the northwest winds will bring a small and brief cool
down for Monday, with highs expected to be in the 40s, followed by
lows Monday night down into the 20s and low 30s. We`ll start to see
southerly winds return on Tuesday in response to height falls to our
west as a trough moves across the Rockies. This will quickly send
highs back into the 50s on Tuesday. Said upper trough will move
across the upper MS Valley on Wednesday and provide us with our next
shot at rain. The big trend with this wave is models have trended
toward this being a weaker and progressive trough. Moisture will be
surging north during the day on Wednesday, with it really just a
question of when does the moisture meet the forcing to make precip.
Once again, this looks like a system that may leave western MN high
and dry, with precip chances best Wednesday afternoon across eastern
MN and western WI. Given the trend toward a progressive wave, we`ve
seen the 1-2" soakers disappear from the ensemble members, with the
strongest QPF clustering coming in around a quarter of an inch.

Behind this system, we dry out for Thursday and Friday, but not cool
down, with highs remaining in the upper 40s to mid 50s. Next
weekend, a deep trough will setup over the western CONUS which looks
to at least lay the foundations for what could be another fairly
active period of weather starting next weekend and continuing into
the following week as we see multiple waves eject out of that
western trough and head into the central CONUS.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1125 PM CST Fri Nov 8 2024

We`re waiting on the rain down in Nebraska to get here during
the day on Saturday. However, it will have a lot of dry air to
overcome first, so did start to delay some the arrival of rain.
This system looks to present itself in multiple wave of light
precipitation. The first looks to come together across southern
MN Sat afternoon, moving into western WI in the evening. A
second area of rain looks to move into southern MN late Saturday
night as the upper low drifts overhead, with some breaks in the
precip likely. CIGS look to remain VFR until a site gets toward
the back edge of the first precip shield and like bringing in
the mention of rain, delayed arrival of MVFR cigs some as well.

KMSP...Basically, starting as early as 21z, there will be a
chance of rain at MSP and that chance will not go away until
around 18z on Sunday. In that time period, on and off rain
showers are expected, with amounts remaining fairly light. MVFR
cigs are expected to set in between 1z and 4z Sunday, with IFR
cigs possible after 8z.

/OUTLOOK FOR KMSP/
SUN...MVFR/-SHRA likely early, bcmg VFR. Wind WNW 10-20 kts.
MON...VFR. Wind N 5-10 kts.
TUE...VFR. Wind SE 15-25G35 kts.

&&

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

&&

$$

DISCUSSION...MPG
AVIATION...MPG