947
FXUS63 KMPX 022018
AFDMPX

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

.KEY MESSAGES...

- Thunderstorms, a few with severe weather and 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, mainly dry weather, and breezy weather expected
  Wednesday into next weekend.

&&

.DISCUSSION...
Issued at 316 PM CDT Sun Jun 2 2024

With a broad shortwave moving across the northern Plains, we`ve seen
southerly h85 winds and associated moisture transport increase
across MN out ahead of that shortwave. This isentropic lift and
moisture transport has resulted in the showers that we saw come out
of eastern SoDak early this afternoon. SPC mesoanalysis at 18z
showed a pocket of 1000+ j/kg of mlCAPE had developed down by St.
James and as soon as this area of showers got to the north of St.
James, a quick uptick in radar reflectivities was noted near Redwood
Falls. With SSE low level flow, this instability won`t make much
progress east, so the intensity of returns we`re seeing back west of
New Ulm at 230pm are not expected to maintain their intensity into
the Twin Cities as they run away from the instability.

For the rest of tonight, there are a couple of things to watch.
First, we`ve seen storms expand across NoDak, this has been the
region of QLCS generation we`ve been worried about the past couple
of days. The other concern we`ve been seeing from the last few runs
of the HRRR and its the potential for the development of scattered
storms this afternoon in eastern SoDak/western MN. Basically, the
HRRR is developing convection on the northeast fringe of the strong
pool of instability over south central SoDak (expected to build to
over 4000 j/kg of mlCAPE). The HRRR has been generating some updraft
helicity tracks with this activity, indicating the potential for
some supercell structures. This potential for more convection to
fire ahead of the NoDak activity has only led to more uncertainty on
how those storms will evolve through the night. The main trend we`ve
seen with the potential for any lines of storms tonight is less
organization. The biggest impact from the lack of organization is we
saw our QPF from WPC take a pretty good hit for tonight. Though
severe probabilities from the SPC have not changed through the day,
given less organization expected, our severe threat for tonight is
trending toward the downward direction.

Monday morning, we`ll see showers clear out of western WI, with dry
weather expected Monday afternoon and evening. Late Monday night, we
may see storm potential pick back up as southerly h85 winds and
associated moisture transport start to tick up. Models right now are
pretty muted on this potential, though as we`ve seen today, models
don`t have the greatest track record with generating enough
convection when you get into the patterns of broad isentropic lift
in a moist environment with a little bit of instability.

Tuesday will feature a strong, negatively tilted short wave working
across the Dakotas during the afternoon, with a cold front sweeping
across MN. With temperature expected to warm in into the low to mid
80s ahead of the front and dewpoints near 70, we`ll have ample
instability for storm development. The CAMs that go out that far
(NAMnest and FV3) both show a pretty healthy band of storms
developing during the heat of the afternoon ahead of the cold front,
which makes sense given the forcing. CSU machine learning severe
probabilities showed an uptick in severe probabilities across the
upper MS Valley, so an upgrade to a Slight Risk when the current Day
3 outlook becomes the Day 2 outlook tonight would not be a surprise.

Not much has changed with the forecast beyond Tuesday. A broad h5
trough will be in place across Canada, with a dip in the flow down
into the Great Lakes. This will put us in northwest flow. This will
result in some pleasant weather conditions as dewpoints fall into
the 40s for several days, with lows in the 40s/50s and highs in the
upper 60s to mid 70s. The only drawback for Wednesday through
Saturday is we`ll likely see northwest winds gusting over 30 mph
each afternoon. We mention it will be mostly dry, but we could see a
little light rain during this period if we see a shortwave working
through in the northwest flow, but there`s been little agreement on
when/where any of these hiccups may occur.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1243 PM CDT Sun Jun 2 2024

Current satellite shows mid-high level cloud cover increasing
across much of Minnesota this afternoon. An area of
showers/storms are moving into western Minnesota, and could
impact KRWF and KAXN within the next couple of hours. Although
the environment is less favorable over central and eastern
Minnesota, this disturbance could bring scattered showers and an
isolated rumble of thunder to areas around KSTC, KMSP, KMKT, and
KRNH. The main line of storms is still on track to move in this
evening/night, with the main threat being strong winds and
locally heavy rain. Cigs will likely drop to low-end MVFR or
high-end IFR overnight, before improving to VFR as the system
moves east. Winds will be out of the S/SE, becoming more SW and
diminishing by tomorrow morning.

KMSP...It is looking more likely that afternoon showers will
impact KMSP, with the potential for some TS in the vicinity.
Confidence is low (10-30%), so left mention out of the TAF at
this time. The afternoon showers could diminish chances for
stronger storms to impact the area later today, but rain and the
potential for thunder is still expected overnight.

/OUTLOOK FOR KMSP/
MON PM...VFR. Wind W 5-10 kts.
TUE...VFR early, then MVFR/SHRA with -TSRA/IFR possible. Wind S bcmg W 10-20 kts.
WED...VFR. Wind W 20G35 kts.

&&

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

&&

$$

DISCUSSION...MPG
AVIATION...BED