742
FXUS63 KMPX 311729
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1229 PM CDT Fri May 31 2024

.KEY MESSAGES...

- Today...Showers and thunderstorms will move across southern
  and eastern MN into western WI. Severe weather is not
  expected, but a few pockets of heavy rain are possible.

- Saturday and Sunday...Most locations will be dry on Saturday
  as rain exits east. Another system will bring thunderstorms
  from the Dakotas into western MN on Sunday. A few storms could
  be severe across western and central MN, but storms should
  weaken as they move toward Wisconsin.

- Tuesday/Night...Another system will bring widespread rain
  Tuesday and Tuesday night. Timing and placement are still
  uncertain, but the potential for severe storms bears watching.

&&

.DISCUSSION...
Issued at 318 AM CDT Fri May 31 2024

TODAY...Showers and thunderstorms were slow to progress eastward
overnight, but have started to fill in across southern Minnesota as
expected. These storms are along a weak boundary that will continue
to sag southeast this morning, but then will stall out and shift
north a bit as a warm front. Low level FGEN will lead to numerous
showers and thunderstorms, and the steering winds aloft will
parallel to the forcing. As a result, the main concern today is
training thunderstorms, heavy rain, and potential for flooding.
Overall this is a lower-end threat in the sense that the footprint
of the heavy rain will be small, and the lack of a tropical airmass
should limit the precipitation amounts. Current forecast has a
pretty broad area of 1 to 2 inches with the northern extent along a
line from Redwood Falls up through the Twin Cities and into Rice
Lake WI. The southern extent is from north central Iowa up through
Rochester MN and Eau Claire WI. Based on the synoptic set up and the
HiRes output, a few locations within this area could see upwards of
3 to 4 inches.

SATURDAY AND SUNDAY...No significant changes from the previous
forecast. On Saturday showers and thunderstorms will be ending
across western WI, so most locations should be dry, which is
welcomed news if you have outdoor festivities planned. on Sunday
the Day4 outlook area for severe weather transitioned to a
slight risk across western MInnesota, with a marginal risk
generally up to the WI/MN border. This event is driven by a low-
amplitude shortwave trough which will lead to a favorable deep
layer shear profile of southerly H925 winds, and westerly H500
winds. There should be adequate instability to support
thunderstorms, and organized convection is expected to develop
Sunday afternoon, and move eastward during the evening and
overnight. Forecast soundings show capping in place across the
warm sector, but this CAP should be just enough to limit early
storm initiation and allow around 2000 J/kg of MLCAPE to
develop. As of now, the main concerns appear to be hail mainly
across western MN, transitioning to more of a wind threat as the
storms congeal and move east.

MONDAY THROUGH FRIDAY...Monday will be dry in the wake of the
departing storm system. The dry period should be short-lived as
another northern stream shortwave trough moves across the High
Plains toward the Upper Midwest. In contrast to Sunday`s system,
this wave is more amplified and takes on a negative tilt and
should have stronger forcing for ascent. Another round of
widespread convection is expected across the Upper Midwest. With
the dynamics in place, the severe weather threat should hinge
on the instability, which is highly uncertain this far out based
on the timing of the system, so for now continued with the
blended forecast guidance.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1222 PM CDT Fri May 31 2024

VFR turning MVFR with periods of SHRA & TSRA for the TAF period
as a front stalls over the area today. TSRA is most likely after
20z through around 02-03z before we lose instability and SHRA
lingers through 10-12z tomorrow. The main uncertainty within the
TAF will be CIG heights throughout with a high probability of
MVFR for most sites that see SHRA and around a 20-25 percent
chance of IFR mainly during the period of SHRA before 12z.
Visibility could also briefly drop to low MVFR/IFR this
afternoon depending on the strength of storms, however
instability is fairly limited so rainfall rates dropping
visibility below 2sm is not expected for now.

KMSP...SHRA into TSRA coverage is expected to increase this
afternoon as the front stalls over the area, with currently
high-res guidance keeping the line directly over the Twin
Cities. The current TAF keeps us MVFR at the lowest, however
there is still a possibility of some IFR visibility with some
stronger TSRA or even tomorrow morning with the lingering -SHRA.

/OUTLOOK FOR KMSP/
SUN...VFR, MVFR/-TSRA likely late. Wind S 5-10kts.
MON...MVFR/-TSRA early, then VFR. Wind SW to NW 10-15kts.
TUE...VFR early, then MVFR/SHRA/-TSRA. Wind SE 10kts.

&&

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

&&

$$

DISCUSSION...JRB
AVIATION...TDH