528
FXUS63 KMPX 082345
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
645 PM CDT Wed May 8 2024

.KEY MESSAGES...

- Scattered, pulse-y thunderstorms expected this afternoon and
  evening across southern Minnesota. Locally heavy rain and a
  few strong or severe storms are possible.

- Periodic shower and thunderstorm chances will continue through
  early next week.

- Temperatures will remain near or above normal.

&&

.DISCUSSION...
Issued at 252 PM CDT Wed May 8 2024

Our stagnant mid/upper level low pattern will slide east tonight,
setting up a nearly horizontal, positively-tilted trough axis along
the Minnesota/Iowa/SoDak border region. Soundings show an inverted-V
setup, with cold air above a warm and dry boundary layer. Surface
temps have already eclipsed 70F in much of southern Minnesota,
supporting a broad area of 500 J/kg SBCAPE embedded with pockets of
1000+ J/kg along the MN/SoDak border. Steep low-level lapse rates
will be enough to create a broad area of showers/storms,
however lack of wind shear should prevent any longer-lived
supercell convection. In other words, we are expected storms to
form and dissipate quickly, leading to isolated hail and strong
downdraft winds. Given the slow movement of the occluded low,
some storms could tap into the effective SRH and form brief
landspouts or weak non-supercell tornadoes. The main threat
will shift to locally heavy rains overnight, with the highest
totals expected south of the MN/IA border.

Northeasterly flow behind the occluded front will advect in slightly
cooler and drier air, leading to quiet weather tomorrow
afternoon/night. An upper-level shortwave disturbance will then
slide southeast through the Great Lakes region on Friday. Steeper
lapse rates and patches of weak MUCAPE will likely lead to a broad
area of scattered showers and thunderstorms across east-central
Minnesota and western Wisconsin. The main forcing, and greatest QPF,
looks to be trending slightly further east into Wisconsin per model
(Euro and GFS) run-to-run change.

The upper-level pattern will stay largely the same through early
next week, with a cut-off low to the west and general troughiness to
the east. Any small scale disturbances that ride down from Canada
would bring similar chances for scattered showers and thunderstorms
over the Upper Midwest. Temperatures will trend 5-10 degrees above
normal, with some areas potentially seeing highs in the 80s Sunday-
Tuesday. The best chance for that comes on Sunday, with nearly 50%
of NBM members breaking the 80F mark across the southern half of
Minnesota.

The cut-off low over the western CONUS will attempt to progress
eastward by mid-week, which would likely be the general
timeframe of our next shot of active weather.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 623 PM CDT Wed May 8 2024

Rain this afternoon has been tied to an upper low over eastern
SoDak and an inverted surface trough up along the MN/SD border.
These features will slowly sag south and east through the
night, which means precipitation is in all likelihood done for
MPX terminals, so removed precip mention from all TAFs. Thursday
morning, as the surface low moves across Iowa, numerous models
show MVFR cigs developing to the north of the low that could
swipe MSP, MKT, & RWF. Those MVFR cigs could come with a few
sprinkles, but moisture on forecast soundings is pretty shallow,
so little in the way of rainfall is expected. After the morning
MVFR threat, skies will clear out through Thursday afternoon
with 10-20 kt NNE winds.

KMSP...The HRRR continues to hint at a shower threat between 12z
and 16z Thursday morning, though RAP forecast soundings show
rather shallow moisture being in place during the morning, which
should really limit the shower threat.

/OUTLOOK FOR KMSP/
FRI...Mainly VFR. Chance PM MVFR/-TSRA. Wind NW 20G35 kts.
SAT...VFR. Wind NW 10-15G20 kts.
SUN...VFR. Wind WSW 10-15G20 kts.

&&

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

&&

$$

DISCUSSION...BED
AVIATION...MPG