124
FXUS63 KMPX 171121
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
621 AM CDT Sat May 17 2025

.KEY MESSAGES...

- Cloudy and breezy again today. Areas of frost likely in western
Minnesota tonight.

- Cooler temperatures continue into next week. Next chance for
  rain arrives Monday into Tuesday.

&&

.DISCUSSION...
Issued at 259 AM CDT Sat May 17 2025

The swirl of a system on GOES 19 continues this morning as our
system will be moving out today, with continued cloud cover and
breezy winds until it pushes into the eastern Great Lakes later
tonight. The persistent light showers tonight are pushing into
western Wisconsin with dry air finally wrapping enough to dry things
out west of the Twin Cities as of around 3am, with eastern MN dry by
6am and western WI by later this afternoon. The focus of the
forecast transitions from light showers to likely frost tomorrow
night for areas of central and western Minnesota with a wedge of
cool air at 850mb following the departing system as our upper level
flow transitions to WNW. Skies will be clearing later in the day and
will allow for rapidly cooling temperatures down into the low to mid
30s in western Minnesota to near 40 in the Twin Cities and western
WI. We are far enough along where everything is green and growing,
such that sensitive plants should be covered or brought inside to
protect them from the cold especially given the warm temperatures
over the last week to 10 days.

The cooler air in the mid levels retreats northwards by early Monday
as we transition towards our next weather system arriving later on
Monday into Tuesday, with a developing trough and surface low
ejecting over the Rockies before stalling over western SD/NE. Lower
level flow over southern Minnesota will tilt towards the southeast
as a warm sector like environment begins to form south of a pseudo-
stationary frontal boundary. The main differences between ensemble
guidance right now is in the placement of said front, which is going
to be the cutoff between little to no rainfall north of the front
and the production of scattered to widespread showers and weak
storms south of the front. Instability is somewhat lacking in
forecast soundings and there is not enough veering to produce good
shear such that thunderstorm potential looks fairly low and some
rumbles of thunder are the expectation, especially as this system
will be much cooler compared to our previous one. The showers could
persist as long as early Wednesday in southern Minnesota before the
upper level low ejects into eastern Canada leaving us with northerly
flow and drying air once again.

There are some hints at a return to warmer temperatures by Memorial
Day weekend within much of the global guidance with warmer 850mb
temperatures developing over the central Rockies and moving towards
the region by Memorial Day. For right now, ensembles show a
significant spread such that confidence is low, however the upper
level pattern looks to favor warming back to at least normal if not
above normal temperatures by the end of the month.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 607 AM CDT Sat May 17 2025

Added TEMPO groups at AXN and STC for a few hours this morning
as periods of IFR cigs look possible. Though, all terminals will
largely be MVFR with low overcast stratus persisting through
most of today. Went a bit more pessimistic for our eastern
terminals with the MVFR stratus failing to lift or break apart
enough to reach VFR by the end of the TAF period. Across
western MN lies more hope as greater breaks in the clouds should
allow for VFR by tonight. Northwesterly winds will be breezy
this morning into the afternoon. Strongest winds are expected in
western MN where sustained values of near 15 knots and gusts to
25 knots are forecast. However, winds gradually slow this
afternoon into this evening, falling to near 5 knots and
becoming more northerly after midnight.

KMSP...Cigs near 1100 feet should persist until about 19Z where
they will then rise to 2000 feet. Have opted to hold onto MVFR
until 08Z given low-level saturation in forecast soundings.
Northwesterly winds will gust to 20-25 knots during today.

/OUTLOOK FOR KMSP/
SUN...VFR. Wind NE 5-10 kts.
MON...Mainly VFR. Chance MVFR/SHRA. Wind E 15-20G30kts.
TUE...Mainly VFR. Chance MVFR/SHRA. Wind E 15-20G30kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Frost Advisory from 1 AM to 9 AM CDT Sunday for Benton-
     Chippewa-Douglas-Kandiyohi-Lac Qui Parle-Meeker-Morrison-
     Pope-Redwood-Renville-Stearns-Stevens-Swift-Todd-Yellow
     Medicine.
WI...None.

&&

$$

DISCUSSION...TDH
AVIATION...CTG