155
FXUS63 KMPX 020906
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
406 AM CDT Sun Jun 2 2024

.KEY MESSAGES...

- Severe thunderstorms & localized heavy rain possible this evening,
especially across western and central Minnesota.

- Another chance for widespread rain and potentially severe
thunderstorms is likely Tuesday.

- Pleasant and mainly dry weather expected Wednesday into next
weekend.

&&

.DISCUSSION...
Issued at 405 AM CDT Sun Jun 2 2024

High clouds associated with a line of thunderstorms that have
developed ahead a weak boundary moving across Nebraska and Kansas
are making their way northward early this morning. The 06z WPC
surface analysis depicts a warm front across central Minnesota,
where some ACCAS have developed over the last few hours. Further
west back into North Dakota, a few isolated thunderstorms have
developed. Southerly flow will continue to bring warm, moist air
northward through this morning and into the early afternoon while
the parent surface low lifts into the western Dakotas. Aloft, a
subtle shortwave will push through this afternoon with an increasing
LLJ nosing into southwestern Minnesota. This could be enough to
spark some storms across southern Minnesota and northern Iowa during
the afternoon. This would be well ahead of the convection that will
be forming over the Dakotas and moving into Minnesota during the
evening along the cold front that hi-res models have been
advertising over the past couple of days. The main question with
this earlier chance of storms will be how it will impact the later,
main line of storms coming out of North Dakota. As these North
Dakota storms develop and progress eastward this afternoon, they are
expected to grow upscale into a QLCS during the early evening hours.
CAMs show this line diving south across central Minnesota and
eventually weakening. Wind will be the main threat, but a few spin
ups along the line in western Minnesota aren`t out of the question
along with some hail.

Even being only 12-18 hours out from the event, there are still some
questions and discrepancies in timing and the southern extent of
this line. As previously mentioned, there`s the question of storms
firing across southern Minnesota during the afternoon. There`s also
the model differences in the timing of the eventual QLCS from the
Dakotas. The ARW is by far the fastest, with the QLCS moving through
the Twin Cities around sunset while the majority of other CAMs hold
off until around or after 06z. There are also differences in
strength/coverage of the line as it moves into a more stable
environment to the east, but current thinking is that it will be
tough for western Wisconsin to see much in the way of severe storms
by early Monday morning. Showers will linger across eastern portions
of the forecast area during the first half of the day before clouds
clear from west to east with mostly sunny skies expected area wide
by Monday evening.

The clear skies will be short lived as cloud cover quickly returns
overnight into Tuesday as yet another warm front lifts northward.
Tuesday looks like it has the potential to be another active weather
day with the threat of heavy rainfall and a few severe
thunderstorms. With the return of strong southerly flow, dew points
look to climb into the mid to upper 60s with temperatures in the low
80s, despite ample cloud cover. Forecast soundings have PW values of
nearly 2", which is impressive considering the 90th percentile for
June 4 is not even 1.5". Aloft, a 500mb trough will take on a
negative tilt as it progresses across southern Canada and the
western Dakotas. A surface cold front is forecast to quickly move
through the area during the afternoon, which would be favorable
timing for thunderstorm development. Heavy rainfall in addition to a
few strong to severe storms look increasingly likely for Tuesday
afternoon and evening. Both of these threats are covered by an ERO
Slight Risk and a SWODY3 Marginal Risk respectively.

The middle of the week through the remainder of the period looks to
be much cooler and quieter as we see northwest flow return. A cutoff
low looks to stall over the northern Great Lakes through Friday. At
the surface, breezy west to northwesterly winds are expected with
gusts of 30-35 MPH possible on Thursday. Highs in the low to mid 70s
with minimal chances for afternoon showers are expected through the
end of the period.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1234 AM CDT Sun Jun 2 2024

With light winds and clear skies, there is some concern for fog
through early this morning at our usual foggy sites (KRNH/KEAU),
but otherwise VFR conditions are expected. High clouds will
move in later this morning with some SHRA/TSRA developing by
late afternoon across western Minnesota before moving eastward
through the end of the TAF period. MVFR cigs/vis are possible
with any of the showers and thunderstorms, but overall VFR will
prevail. Winds will be light and variable this morning before
becoming southeasterly around 10-15kts with gusts to 25kts.

KMSP...There`s a small chance for some thunder to develop ahead
of the main line later this afternoon, but best chances still
look to hold off until 06z or later and last into Monday
morning.

/OUTLOOK FOR KMSP/
MON...MVFR/-RA early chc TS, then VFR. Wind W 5-10 kts.
TUE...VFR early, then MVFR/SHRA/-TSRA. Wind S bcmg W 10-20 kts.
WED...VFR. Wind W 15-20G30-35 kts.

&&

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

&&

$$

DISCUSSION...Dye
AVIATION...Dye