Forecast Discussion / NWS-Twin Cities

780
FXUS63 KMPX 140507
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1107 PM CST Mon Jan 13 2025

.KEY MESSAGES...

- Cold temperatures alongside 5-10mph northwest winds will help low
temperatures drop into the single digits to low teens below zero
tonight. Wind chills will drop into the low to mid 20s across the
area.

- We warm into the mid to upper 30s Thursday and Friday before
dropping back into a prolonged stretch of below normal temperatures
beginning this weekend.

- No chances for snowfall through the 7 day forecast.

&&

.DISCUSSION...
Issued at 238 PM CST Mon Jan 13 2025

GOES satellite imagery shows an unexpected surprise across portions
of Minnesota this afternoon in the form of cumulus from daytime
heating especially along the temperature gradient from the snowpack
versus no snowpack in southern Minnesota. There is also a bank of
mid level clouds moving through western Wisconsin in addition to
another bank of lower clouds making their way east from the Dakotas.
CAM guidance has been exceptionally poor in resolving both the
spread and motion of clouds today, which is troublesome given the
main topic of this discussion will be cold temperatures overnight
which tend to be very reliant on whether or not there is cloud
cover. The hourly cloud cover forecast is a Frankenstein`s monster
of multiple model blends plus hand edits given the poor model
performance, the main consequence of said performance being
confidence remaining too low to issue any cold weather headlines
with the afternoon forecast. Even a small amount of cloud cover
could be the difference of 2 to 3 degrees tonight, and our current
temperature forecast hovers a degree or two lower than our cold
weather advisory criteria right now. Given the uncertainty with
cloud cover and how they will impact temperatures, any decision on
cold weather headlines is being postponed until the 00z suite of
model guidance is produced with hopefully a better handle on the
situation overnight. For now, expect cold temperatures and wind
chills generally in the 20s below zero across the region, with upper
20s below zero most likely in west-central Minnesota with `warmer`
low 20s below zero through the Twin Cities and western Wisconsin.

The 1038mb (per the GFS) arctic high producing the cold temperatures
will be displaced by an amplified upper level ridge with a narrow
jet streak diving southwards within the northerly flow by Thursday,
which should allow for surface conditions to rebound back towards
the 20s to 30s above zero for temperatures as the cold air gets
ejected over the northeastern CONUS into eastern Canada. Low level
WAA should allow for highs reaching into the mid to upper 30s which
would be enough to significantly melt much of the lingering snow
around the Twin Cities, but not enough to melt things further north
where the heavier snow fell this past weekend. The degree of
snowmelt will have implications later on in the forecast period, as
a fresh snowpack typically helps keep especially low temperatures
colder in comparison to bare ground. As we head through the weekend,
a strengthening arctic upper level low will drive southwards into
central Canada with deep troughing across the CONUS, producing
northerly to northwesterly flow aloft and in the lower-mid levels of
the atmosphere. The northerly flow originating from the arctic
circle will drive colder air southwards across most of the CONUS
with the GEFS mean surface high by Monday above 1040mbs across a
significant portion of the northern United States. This will be the
beginning of what looks to be a more prolonged outbreak of colder
arctic air across the region, with our coldest stretch of weather
arriving early next week and lingering through the rest of the
month. The main wild card factor is the lack of deep snowpack which
could limit the extreme cold temperatures to only a few days where
the arctic air arrives before we slowly begin moderating back into
the teens to 20s for highs. For now, expect some significant cold
weather early next week followed by continued colder than normal
conditions afterwards until we see a significant airmass shift.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1057 PM CST Mon Jan 13 2025

The deck of MVFR clouds that had been affecting our southern and
eastern terminals this evening has pushed to our southeast. VFR
conditions are expected the remainder of the period. Scattered
to broken clouds from 5000-8000 feet across eastern MN and
western WI will eventually also clear out by Tuesday afternoon
and give way to area-wide high clouds the remainder of the
period. Northwesterly winds will fall to 5-10 knots quickly
tonight, holding thru the afternoon, before becoming light with
a more southerly component Tuesday evening.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
WED...VFR. Wind SW 10-15 kts.
THU...VFR, chc MVFR. Wind NW 5-10 kts.
FRI...VFR. Wind NW 10-15 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Cold Weather Advisory until 9 AM CST Tuesday for Chippewa-
     Douglas-Kandiyohi-Morrison-Pope-Stearns-Stevens-Swift-
     Todd.
WI...None.

&&

$$

DISCUSSION...TDH
AVIATION...CTG

NWS MPX Office Area Forecast Discussion