NWS Forecast Discussion

Below is the latest Area Forecast Discussion from the Twin Cities National Weather Service office in Chanhassen, MN. It gives insight into why the forecasters are making the predictions you read in your local forecast. The overall "big picture" of the atmospheric setup is well described, as well as the forecasters' interpretation of the various Computer Atmospheric Models (CAMs). Sometimes, very specific information is available here that is not available, or otherwise generalized, in the public forecast.

843
FXUS63 KMPX 311158
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
658 AM CDT Mon Mar 31 2025

.KEY MESSAGES...

- Another widespread precipitation event will impact the area
  Tuesday and Wednesday. A messy mix of precipitation types is
  expected again. Greatest threat for heavy snow continues to
  reside in central Minnesota, where a Winter Storm Watch has
  been issued.

- An extended period of quieter weather sets in for the end of
  this week into next week, with temperatures running slightly
  below normal.

&&

.DISCUSSION...
Issued at 323 AM CDT Mon Mar 31 2025

Things are much quieter tonight, with the surface low pulling
through the Great Lakes and high pressure moving in from the
Dakotas. However, water vapor imagery shows our next trouble maker
crashing into Oregon & Washington. For today, high pressure will
give us our breather between storm systems, with a mix of sun and
clouds, but temperatures will struggle to hit 40 (average highs are
already pushing 50).

That storm system mentioned out by Oregon and Washington will start
to impact us Tuesday morning, with precip lasting into Wednesday
evening. This will once again be a very complex p-type system. The
surface low is forecast to track across southeast MN and western WI
on Wednesday, which will put the precipitation type transition
somewhere over the MN portion of the MPX area. Precipitation will
begin Tuesday morning over western MN and quickly spread ENE across
southern/central MN through Tuesday afternoon. This will be driven
by strong isentropic ascent at the nose of a 50+ kt h7 jet. What
type of precipitation falls with this band will be driven by the
depth of the near surface melting layer. Most of the CAMS show this
initial band on Tuesday falling as snow, though the difference
between this being a 34 degree heavy snow or a 35 degree downpour is
incredibly small. As we move through Tuesday night, the h85 & h7
lows will begin moving north across eastern SoDak, with those
features ending up over the Arrowhead by the end of the day on
Wednesday. Warm air will surge north to the east of the h85 & h7
lows, which will change precip over from snow to rain through the
night across southern MN into western WI. Exactly where the
transition line sets up will be key to where the "winner" in the
snowfall department ends up, as in all likelihood, we will see
double digit snowfall total just to the northwest of where the rain
snow line sets up by Wednesday morning. EPS probabilities continue
to paint central MN (centered around Alexandria, Fergus Falls, and
Brainerd) as being the most likely area to cash in on this snow
event. However, given the uncertainties with where the rain/snow
line sets up and how long the transition to rain takes Tuesday
night, we did add a bit of southern buffer to the Winter Storm
Watch, bringing it down to Swift, Wright, and up to Isanti county.

For the end of the week, a Rex block is still forecast to develop
over western North America. This will set us up into a 7-10 day
stretch of quiet weather under predominately northwest flow, which
will keep temperatures running on the cooler side of normal to start
April. However, you do have to remember, we start April with average
highs around 50. With this pattern in place, it is looking highly
likely that the next system ejecting across the Plains on Saturday
will be shunted to our south, with cool and dry being our scenario
as a trough swings through here over the weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 636 AM CDT Mon Mar 31 2025

Pretty quiet weather today, with nothing more than this batch of
clouds between 4k and 5k feet to deal with this morning.
Overnight we`ll see winds switch from the northwest over to the
southeast. By the end of this period, we`ll have precip rapidly
approaching AXN/RWF at 12z and MSP at 18z.

KMSP...By the end of the TAF, it will either be precipitating,
or precip will be imminent. For the type, we`ll be on the cusp
of either having a 34 degree snow or 35 degree rain.

/OUTLOOK FOR KMSP/
TUE...MVFR/IFR w/-RASN. Wind SE 10-25G25kts.
WED...MVFR/IFR, -RASN. Wind E 15-20G30kts bcmg SW 20-25G35kts.
THU...Chc MVFR cigs. Wind NW 10-15kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Winter Storm Watch from Tuesday morning through Wednesday
     evening for Douglas-Kandiyohi-Pope-Stevens-Swift.
     Winter Storm Watch from Tuesday afternoon through Wednesday
     evening for Benton-Isanti-Kanabec-Meeker-Mille Lacs-
     Morrison-Sherburne-Stearns-Todd-Wright.
WI...None.

&&

$$

DISCUSSION...MPG
AVIATION...MPG

NWS MPX Office Area Forecast Discussion