Dense Fog Advisory 21, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
254 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 /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1041 PM CST Sun Dec 10 2023

Stubborn stratus deck continues to hang on with indications it
may not scatter out for MSP and surrounding areas until
early/mid Monday afternoon. Cigs are flirting MVFR/IFR threshold
which should be the case through much of the overnight and
Monday morning. A wind shift to northwesterly will clear any
lingering moisture Monday evening, with gusts to 20-25 kts
after 00Z-03Z.

KMSP...Low-end MVFR stratus will continue into early/mid Monday
afternoon. Some brief dips into IFR are possible through this
time, especially later tonight and early Monday morning. Winds
currently light and variable will become SSWerly over the next
few hours and continue through Monday. Cold frontal passage will
bring winds around from the northwest 02Z-03Z time frame with
gusts to 20 kts.

/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...None.
WI...None.

&&

DISCUSSION...MPG
AVIATION...DPH

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
220 PM CST Sun Dec 10 2023

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
112030-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa-
Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington-
Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota-
Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth-
Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Eau Claire-
220 PM CST Sun Dec 10 2023

This Hazardous Weather Outlook is for portions of central and
southern Minnesota, and west central Wisconsin.

.DAY ONE...Tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will not be needed.