611
FXUS63 KMPX 301948
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
248 PM CDT Thu May 30 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 /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1225 PM CDT Thu May 30 2024

A difficult TAF period ahead with increasing clouds and shower
chances increasing after 00z as they spread eastwards overnight.
AXN/RWF are already seeing -SHRA/-TSRA approaching the sites by
20-21z, with increasing chances by 00z. As we get past 02-03z,
-TSRA should transition to mostly -SHRA as the line pushes
 towards the rest of the sites. Winds initially at 150-180 at
 10-15kts gust up to 25kts through this afternoon before
 decreasing as the -SHRA arrives. Chances for -TS once again
 pick up towards the end of the period roughly 18-21z tomorrow.

KMSP...The main consideration within the TAF is whether or not
to include TS mention overnight, which has been omitted in favor
of -SHRA for now. There is still a roughly 10-20 percent chance
for lightning from 06z to 13z which is the primary time frame
for -SHRA, however the confidence is still fairly low as the
environment remains unfavorable until tomorrow afternoon.

/OUTLOOK FOR KMSP/
SAT...VFR/MVFR, chc -TSRA. Wind SW 10-15kts.
SUN...VFR, likely MVFR/-TSRA late. Wind S 10-15kts.
MON...MVFR/-TSRA early, then VFR. Wind W to NW 10kts.

&&

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

&&

$$

DISCUSSION...TDH
AVIATION...TDH