FXUS63 KMPX 111134
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
534 AM CST Mon Dec 11 2023

.KEY MESSAGES...

- No impactful weather is expected over the next 7 days, with
  temperatures returning to well above normal levels Thursday
  through next weekend.

&&

.DISCUSSION...
Issued at 253 AM CST Mon Dec 11 2023

Satellite imagery this morning looks an awful lot like it did 24
hours ago, with stratus covering almost all of MN and WI as it got
trapped beneath an inversion, with light winds that were not able to
mix it out. Overnight, we've seen the west edge of the stratus field
slowly descend to the point where we're starting to see some dense
fog form in southwest MN. As for when it may go away, as southwest
winds pick up in strength, this should help to finally push the
stratus northeast. In addition, the GOES cloud thickness imagery
shows an expanding patch of decreasing thickness in the stratus
between the Twin Cities and Mankato, so this decreasing thickness
trend along with increased mixing from southwest winds lends some
confidence that we will finally see the stratus get pushed to the
northeast this afternoon, but we did further delay its demise in the
grids. These southwest winds are developing ahead of a cold front
that will sweep across the area this evening. Despite being in the
warm sector today, we did lower highs a few degrees given the
fog/stratus the meager sun angle will have to overcome before it can
start heating the ground. The coldest air and resultant deepest
dendritic growth zone behind this front will be up around Lake
Superior, so any flurry/snow shower activity behind this front
Monday night will remain northeast of our area. Behind this front,
Tuesday will see highs largely remain in the 20s and after that,
winter goes into hibernation.

From Wednesday through next weekend and beyond, upper ridging will
dominate western into central North America. We'll have weak flow
locally, with the northern stream remaining well to our north, which
will keep us stuck in a persistent feed of mild airmasses of Pacific
origin. We continue to have a dry forecast, but there is still a
signal in the ensembles for some precip potential Friday/Friday
night. However, there has been little run-to-run consistency with
this precipitation potential over the last few days, with it showing
up in one model run, only to disappear in the next. Given this lack
of consistency, along with the weak flow present, didn't see a
reason yet to deviate from our current dry forecast. At any rate, if
we do see precip, we're likely talking about amounts under 0.05" and
with a type of just plain rain. As for temperatures, they will be
very mild. In fact, from Thursday through next weekend, highs most
days should be in the 40s. NBM 90th percentile each day is 3 to 5
degrees warmer than what we have in the forecast, which is plausible
for highs depending on what we do for things like timing of fronts
and sky cover. This means seeing a few more 50s for highs,
especially in southern MN is not out of the question as we work
toward the end of the week into next weekend. And of course looking
at the 8-14 day outlook from the CPC, these mild airmasses look to
stick with us pretty much right up to Christmas. Historically, the
Twin Cities sees a white Christmas (a snow depth of at least 1" with
the 12 UTC observation) about 75% of the time. This year, that white
Christmas probability is likely down more in the 10%-20% range.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 528 AM CST Mon Dec 11 2023

Stratus deck remains and it likely won't scatter out for MSP
and surrounding areas until mid/late afternoon. Cigs have been
IFR/MVFR all night, with a few LIFR cigs and vis in western MN
as fog limits visibility. Winds will shift to the northwest and
strengthen, with gusts to 20-25 kts after 00Z-03Z.

KMSP...Low-end MVFR stratus to continue through the early afternoon.
Cold frontal passage Monday night will bring NW winds to the
terminal around 03Z, with gusts to 20 kts possible.

/OUTLOOK FOR KMSP/
TUE...VFR. NW 10-15G20 kts.
WED...VFR. SW 5-15 kts.
THU...VFR. SW 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Dense Fog Advisory until 9 AM CST this morning for MNZ073-074-
     082-091.
WI...None.

&&

$$

DISCUSSION...MPG
AVIATION...PEM