902 
FXUS63 KMPX 142112
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
312 PM CST Wed Dec 14 2022

.SHORT TERM...(This evening through Saturday Morning) Issued at 310 
PM CST Wed Dec 14 2022

KEY MESSAGES: 

- Snowfall returns tonight, with heavy snowfall expected from 
central Minnesota through western Wisconsin through Thursday.

- The heaviest snow will fall Thursday morning, where forecast 
amounts of 3-6" are expected during a short period of time leading 
to travel hazards during the morning commute.

- Light snow continues Thursday night through Friday.

Precipitation has mostly ended this afternoon across the area, as 
the dry slot of a well-developed area of low pressure sits over the 
region. Winter weather will return tonight as the dry slot exits the
region, and very strong forcing aloft move over the region as the 
surface & upper-level lows move directly over the area. The strongest
forcing arrives tonight through tomorrow morning, as a potent 
shortwave pivots around the low from the southern Plains directly 
into the upper Mississippi Valley. This will cause the already mature
surface low to actually reintensify over the area tomorrow, and lead
to a 6-8 hour window of heavy snow expected from central Minnesota 
through western Wisconsin.

Light rain/drizzle will become more widespread this evening as 
forcing begins to increase over the region and temperatures remain 
above freezing. As the strongest forcing from the shortwave arrives 
tonight, surface temperatures are expected to dynamically cool 
closer to freezing which will result in a changeover from rain to 
snow from east to west around midnight. Deterministic and ensemble 
consensus is high in QPF amounts greater than 0.5" during a 6-8 hour 
window across west-central Wisconsin, and between 0.3 to 0.5" across 
central and eastern Minnesota. These liquid precip amounts coupled 
with forecast snow ratios around 10:1 mean snowfall accumulations of 
4-6" across western WI and 2-4" across central & eastern MN falling 
during a relatively short window of time. Model consensus is also 
high for this burst of heaviest snow occurring during the overnight 
hours across western Wisconsin, and early to mid-morning across 
central and eastern Minnesota. Snowfall rates around 1" per hour 
during this time along with the wet & heavy nature of the snow means 
major travel impacts are expected during the morning commute.

Snowfall rates will gradually diminish through the morning and 
afternoon as the strong forcing from the shortwave moves north of 
the area. However, light snow is expected to continue falling all 
the way through Saturday morning as the fully matured area of low 
pressure slowly sits and spins over the region. Snowfall 
accumulations are only expected to be on the order of of 1-2" every 
12 hours starting Thursday afternoon, but this will still lead to 
another 2-4" of snowfall accumulation on top of the snow that will 
have accumulated by the end of Thursday morning. All in all, the 
highest snowfall accumulations of 8-12" by Saturday morning are 
expected in western Wisconsin,  generally along and east of a Polk-
Eau Claire county line in western Wisconsin. Total amounts of 4-8" 
are expected across central and eastern Minnesota, while amounts 
should be generally around 3-4" or less across southern Minnesota

A Winter Storm Warning has been issued until Friday night across 
central & eastern Minnesota through western Wisconsin - where the 
heaviest snow and greatest travel impacts Thursday morning are 
expected. A Winter Storm Advisory has been issued for south-central 
Minnesota where lesser snowfall accumulations and travel impacts are 
expected.

.LONG TERM...(Saturday through Wednesday) Issued at 310 PM CST Wed 
Dec 14 2022

Key Messages:

- Light lingering snow will come to an end on Saturday.

- High confidence in below normal temperatures through the end of 
the year.

After this week's messy weather, a break in excitement will arrive 
later in the day on Saturday. A few hours of light snow to the east 
of the Twin Cities is possible, but things should be quiet on the 
precipitation front at least through Tuesday. 

Saturday onward will, however, bring chilly arctic air to the region 
as the trough departs eastward. Northwesterly winds will hold strong 
for at least a couple of days, giving no reprieve from the single 
digit high temperatures currently forecast for late weekend into 
early next week. This is good news for those who are prepping back 
yard ice rinks and wishing for a white Christmas, as Friday will 
likely be the last time in 2022 that we will see above freezing 
temperatures.

By late Tuesday into Wednesday of next week, the signal remains for 
some snow across the CWA as a Canadian low pressure system will dip 
south of the border. Model discontinuities exist, so not much more 
can be said on this potential system other than there is a chance 
for more snow by the middle of next week. Given the forecast 
temperatures, P-types won't be an issue with any precipitation that 
does fall.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1242 PM CST Wed Dec 14 2022

Precipitation has mostly ended at area terminals this afternoon,
outside of some intermittent drizzle. IFR ceilings already exist 
over the area and will only trend lower as precipitation returns this
evening. Visibility will drop to MVFR/IFR levels late this afternoon
& evening as drizzle become more widespread. Drizzle/light rain will
then transition over to snow around midnight across central MN & 
western WI terminals, and during the early morning across western 
Minnesota. Visibility around 1SM is expected during the snow, with 
periods down as low as 1/2SM possible in the hours before sunrise. 
The snow will continue through the morning, but gradually diminish in
intensity with visibility likely reaching MVFR by the end of the 
period. IFR ceilings are expected to persist through the period.

Continues easterly winds will persist into this evening, with gusts
around 20 kts diminishing by tonight. Winds will back from easterly 
to northerly overnight and through the morning as the surface low 
passes over the area. Speeds will diminish to below 10 kts overnight
and remain around 10 kts or less through the morning.

KMSP...Drizzle will become more widespread this evening with
visibility gradually becoming more MVFR. Expect snow to begin at the
terminal around midnight, with visibility quickly dropping to around
1SM as the snow begins. A few hours of visibility approaching 1/2SM
is possible during the heaviest snow, which is mots likely between
2-6 AM. Snowfall accumulation of 2-4" is expected leading up to &
during the morning rush. Snowfall intensity will gradually diminish 
through the morning, but intermittent MVFR snow is likely into the 
afternoon.

Winds will slowly back from easterly to northeasterly this evening 
and through the overnight hours. Winds are expected to become more 
northerly as opposed to northeasterly by 5-6 AM.

/OUTLOOK FOR KMSP/
Sat...MVFR cigs likely. Wind NW 10-15 kts gusting to 25 kts. 
Sun...MVFR cigs possible. Wind W 5-10 kts. 

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Winter Storm Warning from 3 AM to 9 PM CST Thursday for Chippewa-
     Douglas-Kandiyohi-Lac Qui Parle-Meeker-Pope-Stearns-Stevens-
     Swift-Todd-Wright-Yellow Medicine.

     Winter Storm Warning from midnight tonight to 6 PM CST Thursday for 
     Anoka-Chisago-Dakota-Hennepin-Isanti-Kanabec-Mille Lacs-
     Morrison-Ramsey-Washington.

     Winter Storm Warning from midnight tonight to 9 PM CST Thursday for 
     Benton-Sherburne.

     Winter Weather Advisory from 3 AM to 9 PM CST Thursday for Blue 
     Earth-Brown-Carver-Faribault-Freeborn-Le Sueur-Martin-McLeod-
     Nicollet-Redwood-Renville-Rice-Scott-Sibley-Steele-Waseca-
     Watonwan.

     Winter Weather Advisory from 9 PM this evening to 6 PM CST Thursday 
     for Goodhue.

WI...Winter Storm Warning from midnight tonight to 6 PM CST Thursday for 
     Barron-Polk-St. Croix.

     Winter Storm Warning from 9 PM this evening to 6 PM CST Thursday 
     for Rusk.

     Winter Storm Warning from 9 PM this evening to 3 PM CST Thursday 
     for Chippewa-Dunn-Eau Claire-Pepin-Pierce.

&&

$$

SHORT TERM...ETA
LONG TERM...PEM
AVIATION...ETA