220
FXUS63 KMPX 310612
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
112 AM CDT Fri May 31 2024

.KEY MESSAGES...

- Showers and weak thunderstorms move from west to east the rest of
today through tomorrow morning. Lingering showers and storms
possible tomorrow. No severe storms currently expected.

- Best chance for widespread showers and storms arrives Sunday into
Monday, with a continued on and off diurnal pattern through next
week. Alongside Sunday into Monday, Tuesday/Tuesday night appears to
have a better chance for a few stronger storms.

&&

.DISCUSSION...
Issued at 248 PM CDT Thu May 30 2024

There are a few strikes of lightning within what has otherwise
remained a cluster of unorganized showers in western Minnesota this
afternoon, with the complex moving from south-southwest to north-
northeast amidst southerly steering winds at the surface. Satellite
shows the limited extent to this grouping as more organized
convection has begun to fire in east-central South Dakota, with this
line of convection producing our only concern-worthy storms for
later this evening as they move into southwestern Minnesota.
Elsewhere, we have upper level clouds stemming from the weak
convection and some fair weather cumulus over portions of western
WI. Showers and weak convection will gradually move eastwards this
afternoon and evening before stalling around sunrise tomorrow
morning with a weak boundary draped over east-central to southern
Minnesota. The question is how long showers linger and if we see any
organized storm activity within, and CAM response has remained
relatively muted today with limited thunderstorm activity due to a
lack of significant instability. The nocturnal showers are propped
up by a present but weak low level jet which looks to dissipate
after sunrise tomorrow morning. Scattered showers overnight could
produce over a quarter inch of rainfall in some locations, however
there will be gaps so not everyone will see appreciable rainfall
from this system as it pushes out of the area tomorrow.

Further chances for isolated to scattered showers and weak
thunderstorms will arrive on Saturday driven by diurnal processes in
an area of weak AVA as a trough swings through central Canada.
Saturday has the best chance to stay mostly dry for the next few
days as the forcing is weak and cloud cover looks to hamper any kind
of significant instability from developing. This changes by Sunday
as flow aloft remains zonal but a strong 850mb jet begins to advect
moisture northwards originating from the Gulf, with instability
growing later on Sunday as the jet strengthens over Minnesota. Upper
level support is weak but present in the form of zonal flow and a
bit of shortwave energy pushing through the region, however the main
player will continue to be a surface low forming at the nose of the
LLJ in northern Minnesota, with WAA and the LLJ helping to produce
more widespread rainfall and the potential for a few stronger storms
late Sunday into early Monday. We have yet to get CAMs involved,
however synoptic scale ensembles and deterministic solutions show a
complex of showers and thunderstorms present over much of the state
by early Monday morning, and there should be enough instability
present to maintain thunderstorms with the main question being the
strength of any storms. For now, expect some widespread moderate to
strong rain showers and the potential for a few storms with a chance
to see a stronger complex of storms or MCS depending on what CAMs
look like as we get a bit closer.

As showers and storms dissipate during the day Monday, we see around
a 24 hour break before yet another system looms on the horizon, this
time in the form of an occluded upper level low producing widespread
synoptic lift and spinning up a surface low by late Tuesday to early
Wednesday. Uncertainty remains fairly high due to differences in
timing and the stacking of upper level and surface features, however
the dynamics to produce more widespread rainfall and stronger storms
does appear present within current guidance. The system continues to
be the primary player in the region through much of next week as it
occludes and spins over the Great Lakes, with decent consistency
over the last few days of this feature persisting through much of
next week. This remains a `wait and see` type of forecast as we need
to get through our first system Sunday into Monday before we can
have greater confidence as it pertains to next week, just keep in
mind that a continued unsettled pattern looks to persist into the
first week of June.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1251 AM CDT Fri May 31 2024

A line of showers and storms associated with a cold front is
slowly making its way across western and central Minnesota late
this evening. MVFR conditions are possible within the line of
showers, but VFR conditions will prevail overall. While the
north end of this line has waned in coverage and intensity over
the past couple of hours, the central portion (currently
impacting KSTC) has seen an uptick in activity. Just out ahead
of this and further south into Iowa, it appears another wave of
showers is developing, likely with the LLJ. This trend is
expected to continue through the early morning hours before
things die out as the front stalls somewhere near KMSP. This
break will be relatively short lived as an additional round of
showers and storms looks to develop by early afternoon for
southern/eastern Minnesota and western Wisconsin. There is
uncertainty in the north/westward extent, so opted to go with a
PROB30 for the mid afternoon hours. Winds will remain fairly
light through the period but are expected to go from southerly
ahead/along the front to westerly behind it.


KMSP...As mentioned above, there should be a break in the
showers by mid morning before another round develops in the
afternoon. Felt confident enough to remove the PROB30 during
this time, but still uncertain in how long these will last into
the evening, so went with a PROB30 after 00z. Winds will be
10kts or less outside of an isolated higher gusts with any
thunderstorms.

/OUTLOOK FOR KMSP/
SAT...VFR/MVFR. Wind SW 5-10kts.
SUN...VFR, likely MVFR/-TSRA late. Wind S 5-10kts.
MON...MVFR/-TSRA early, then VFR. Wind SW to NW 10kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...Dye