822
FXUS63 KMPX 161115
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
615 AM CDT Mon Jun 16 2025

.KEY MESSAGES...

- Showers and thunderstorms looking increasingly likely this
  morning, from a decaying thunderstorm complex out of the
  Dakotas

- This will influence the potential for severe weather this
  afternoon and evening, but it remains too early to say when &
  where the threat may be lowered.

- Active pattern continues through the week with a return to
  above- normal temperatures for the weekend.

&&

.DISCUSSION...
Issued at 203 AM CDT Mon Jun 16 2025

Complex forecast today regarding the evolution of multiple areas
of thunderstorms development across the Upper Midwest, and how
they may influence our potential for severe weather this
afternoon and evening. Overnight, a shortwave tracking along the
North Dakota/South Dakota border has generated a robust
mesoscale convective system, with gusts up to 90 mph being
reported. Farther south, a broken line of thunderstorms has
developed across South Dakota along a weak surface cold front.
These areas of thunderstorms are expected to continue unabated
across the Dakotas through the early morning, with the questions
being how strong will they remain as they enter western
Minnesota, & how long will they potentially last into eastern
Minnesota & western Wisconsin. MUCAPE values will actually be
increasing through the early morning across western Minnesota as
warm & most advection continues, however deep shear values drop
off greatly across eastern South Dakota & western Minnesota.
Hi- resolution model scenarios are a complete grab-bag with
many of them struggling to resolve the thunderstorm complex
along the ND/SD border. The models that do have a handle on the
ongoing convection generally weaken the complex as it moves
through the eastern Dakotas into western Minnesota early this
morning, but maintain at least broken showers and thunderstorms
all the way into eastern Minnesota & western Wisconsin through
the morning. MCS maintenance parameters show a low chance
(20-30%) of the ongoing complex remaining severe into western
Minnesota & very low chance (<10%) into eastern Minnesota, so
some wet weather looks likely this morning but probably nothing
severe. At the same time, an ongoing region of scattered
showers and thunderstorms driven by the low- level jet will
continue into this morning across southern Minnesota.

Current radar timing trends project the weakening complex of
showers and thunderstorms reaching western Minnesota by 6-7 AM,
eastern Minnesota by 8-9 AM, & whatever remains of it moving
out of western Wisconsin before 11-noon. The question then
begins how much warming are we able to see during the afternoon
and will the atmosphere destabilize enough for a second round
of storms to develop during the afternoon and evening. The
already limited sample size we have of high-resolution models
handling the ongoing convection show a wide range of outcomes,
making this a lower-confidence forecast for the severe potential
this afternoon until we get through the first wave of precip in
the morning. Taking an ensemble of high-resolution models shows
surface-based CAPE values do recover to 2000-2500 J/kg by mid-
afternoon across western & southern Minnesota, albeit weakly
capped. It wouldn`t take much forcing to get a few storms to
initiate in this environment, and we should have plenty of
remnant outflow boundaries in addition to the weak surface cold
front, but it`s tough to pinpoint when & where this initiation
could occur. Best guess would be at least a few storms develop
later in the afternoon/early evening across west-central
Minnesota, & then potentially merge into a convective line
depending on the amount of instability present. A weaker
afternoon environment means we may see just a few marginally
strong-severe storms, while one with 2000+ J/kg CAPE means our
severe event is still on, with initial storms capable of very
large hail and damaging winds eventually merging into a line of
storms with more of a damaging wind threat & the chance for a
few tornadoes. While the coverage of strong to severe storms
this afternoon remains very uncertain across central Minnesota,
storms looks to be much more widespread across northern
Minnesota along the remnant MCV from the ongoing Dakotas
thunderstorm complex. The bulk of this activity will likely stay
over northern & north- central Minnesota, but several high-
resolution models depict a thunderstorm complex capable of
widespread damaging winds, which may dip far enough south to
impact our northern counties of central Minnesota & western
Wisconsin (Stevens County MN through Rusk county WI).

Very long story short, we don`t have a handle on how things may
unfold this afternoon at the moment, but should have a much
better idea by late morning or early afternoon when we can
better pinpoint where surface boundaries have set up & how our
instability tends are looking for the afternoon. Have a severe
weather plan for later this afternoon & evening, and closely
monitor the forecast for updates as we head into the afternoon.

For the rest of the week - the pattern remains active over the
Upper Midwest but we may see a break in the thunderstorms
midweek as the jet stream dips more southerly over the mid-
Mississippi valley. Multiple rounds of showers and thunderstorms
are still likely with this pattern, but models are showing a
trend towards the bulk of this activity mainly staying just
south of the area. A shortwave Tuesday night morning will
generate widespread thunderstorms and probably the best chance
for heavy rain & flooding this week, but most guidance keeps
this activity over Iowa with maybe the northern fringes of this
activity leading to some thunderstorms over far- southern
Minnesota. Otherwise, Wednesday & Thursday look notably drier
over our area aided by building ridging over the central plains.
This ridging will lead to much warmer temperatures by Friday &
especially over the weekend, with temperatures potentially
nearing 90 along with summer-like humidity. The building ridging
will also place the upper midwest under a potentially active
"ring of fire" pattern, where a number of shortwaves ride along
the northern periphery of the ridge. Pick a model & you`ll find
any number of potential heavy rain and severe thunderstorm
events, but models notoriously struggle with depicting these
shortwaves at this timescale. Confidence is high towards above-
normal temperatures and at least the potential for anther round
or two of thunderstorms, but low on where and when any of these
systems may develop.

&&

.AVIATION /12Z TAFS THROUGH 12Z TUESDAY/...
Issued at 603 AM CDT Mon Jun 16 2025

Areas of fog, especially in western MN, should burn off within
the next few hours. IFR/MVFR cigs at AXN/EAU should rise to VFR
by late this morning. All terminals should remain prevailing
VFR through at least this evening. WI terminals should see a
degradation in cigs during Monday night. The line of
thunderstorms currently entering western MN should continue
northeast, passing close to AXN and STC. Due to still remaining
uncertainty of if storms affect these terminals, have kept
PROB30s for rain this morning. Scattered showers and storms over
southeast MN and western WI will push east and clear our area
over the next few hours. Have also kept the PROB30s at all
terminals for this afternoon and into this evening, as CAMs
suggest scattered storms developing near central MN and
traveling southeast. If these storms occur, there is a good
chance they will be severe with damaging winds and large hail as
the main threats. Southerly winds will increase to 10-12 knots
today with gusts to 20 knots. Winds slow tonight and turn west-
northwesterly.

KMSP...Showers will pass near the terminal for the first 2 or so
hours. Removed any mention of a morning round of -TSRA as CAMs
are keeping the main morning line of storms well north. Have
kept the PROB30 for -TSRA for this afternoon/evening with models
still showing large uncertainty with storm timing and location.

/OUTLOOK FOR KMSP/
TUE...VFR/MVFR chc IFR/-TSRA. Wind NW 5-10kts.
WED...MVFR/-SHRA chc IFR/-TSRA. Wind N 5-10kts.
THU...VFR, chc MVFR/-TSRA. Wind W 5-10kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

$$

DISCUSSION...ETA
AVIATION...CTG