237
FXUS63 KMPX 072011
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
311 PM CDT Tue May 7 2024

.KEY MESSAGES...

- Scattered thunderstorms beginning to develop this afternoon
  across east-central Minnesota & western Wisconsin. A few
  strong storms are possible through this evening.

- Another round of thunderstorms & locally heavy rain is
  expected Wednesday night across far-southern Minnesota.

- Less active pattern is likely to end the week.

&&

.DISCUSSION...
Issued at 305 PM CDT Tue May 7 2024

A line of spotty showers/storms developed late this morning over
western Renville county, and has slowly progressed further
north up into north-central Minnesota. As the associated
boundary moves northeastward, development is expected further
south and east of the current line. The NAM 3km seems to have
the best handle of the storms this morning, which would put our
main time period for development around 3pm local time and
lasting through 9-10pm in western Wisconsin (if you buy into
this specific model). Any storms that pop up over east-central
Minnesota and western Wisconsin will have the potential to
produce small hail, gusty winds, and a few brief spin-ups. The
combination of 500-1000 J/kg MLCAPE, 25-30 kts of effective bulk
shear, and a slight signal of enhanced stretching potential
should be enough to support these organized storms capable of
producing the aforementioned hazards. Spotty rainfall amounts
close to 0.5"+ are likely for areas that are impacted by storms
this afternoon, especially over western Wisconsin where more
widespread rain chances is expected.

Another period of scattered showers/storms is on deck tomorrow
afternoon into Thursday as the upper-level low over the Northern
Plains spins a few blips of vorticity into southern Minnesota. This
will prompt multiple rounds of slow-moving, training thunderstorms,
with the main hazard expected to be excessive rainfall. Ensemble
guidance continues to highlight the potential for localized
rainfall amounts in exceedance of 3" along the Minnesota/Iowa
border. The exact location of this heavy rainfall will likely
be unknown until the event is underway, however the potential is
there for a flooding threat in southern Minnesota Wednesday
night into Thursday.

Drier conditions are likely following this system, as northwest flow
sets up aloft, however isolated chances for diurnally-drive showers
will remain in place most afternoons/evenings. A brief cooldown is
expected on Thursday after the gradual passage of the upper low,
then temperatures will generally trend up into the low-mid 70s over
the next week or so. A return to a more active pattern does not look
likely until mid-late next week potentially.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1211 PM CDT Tue May 7 2024

A line of showers has popped up between KRWF and KAXN early this
afternoon. This is much earlier/further west than models had
this morning, so adjusted TAFs accordingly. In far western
Wisconsin, a few light radar returns are starting to pop as
well. Still thinking that later this afternoon TSRA will become
more widespread from KMSP and points eastward, but will still be
fairly scattered in nature. As such, have opted to go with
TEMPO instead of prevailing. Thunder chances drop off quickly
after 03z. Winds will turn southwesterly and become light and
variable overnight as the surface low moves overhead.

KMSP...As mentioned above, still anticipating a few scattered
showers and thunderstorms this afternoon, mainly after 22z.
Another chance for showers exists near the end of the period,
but confidence is low just how far north these will extend.

/OUTLOOK FOR KMSP/
THU...VFR. Wind NE 10G20 kts.
FRI...Mainly VFR. Chance PM MVFR/-TSRA. Wind NW 15G25 kts.
SAT...VFR. Wind NW 10-15G20 kts.

&&

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

&&

$$

DISCUSSION...BED
AVIATION...Dye