514
FXUS63 KMPX 011933
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
233 PM CDT Tue Jul 1 2025

.KEY MESSAGES...

- Airmass thunderstorms possible on Wednesday across eastern MN
  and WI. Additional rain possible over southern MN Wednesday
  night.

- Better chances for showers and storms area-wide Friday into
  Saturday before a frontal passage occurs.

&&

.DISCUSSION...
Issued at 232 PM CDT Tue Jul 1 2025

It`s a beautiful summer day today with only fair weather cumulus
clouds this afternoon and highs in the 80s. The weather remains
mostly tame tonight as lows fall into the low to mid 60s. We do have
20% PoPs in western and southwestern MN for most of Wednesday
morning as WAA could generate some showers. However, slightly better
chances for rain will be Wednesday afternoon into the evening as an
upper-level trough passing through the Upper Great Lakes may cause
scattered showers and storms to develop over eastern MN/WI. The
Storm Prediction Center does have our entire area highlighted in a
Marginal risk for damaging winds and large hail. 1500-2500 J/kg of
MUCAPE and 30-35 knots of shear could allow for one or two
supercells or stronger clusters of storms. The tornado threat looks
very low as low-level shear is meager at best. This activity should
dissipate as we go into Wednesday night, but a few forecast models
suggest an additional area of rain developing over southern
MN/northern IA in response to low-level WAA. This activity should be
small in area but the 12Z HREF shows the possibility of a thin strip
of +0.5" rainfall from training storms near I-90 Wednesday night.
This activity will either dissipate or move southeast by sunrise
Thursday.

Highs look to remain within the 80s Thursday through Friday but some
areas may approach 90 as warmth slowly increases. Isolated showers
and storms may occur (20-30% chance) over WI Thursday night within a
mini "ring of fire" setup. Much better chances for rain arrive
Friday afternoon and look to last through Saturday night, as the
upper-level ridge that was overhead on Thursday moves east.
Proceeding in its place will be several mid-level impulses within
west-southwesterly flow. Guidance favors showers and storms
developing in the eastern Dakotas and western MN later Friday with
the arrival of the first mid-level impulse. Some storms could be
strong as highs in the upper 80s and moist air should allow for at
least 2500 J/kg of MUCAPE. Though, thankfully a significant severe
threat doesn`t seem likely at this time as bulk wind shear is well
under 30 knots. Large hail may be possible with initial updrafts,
but the wind threat would become a better possibility if storms grow
upscale as they travel east during Friday night. In addition to the
severe threat, guidance shows rain being widespread over MN Friday
evening into Saturday morning, likely putting a damper on 4th of
July activities. PWATs of 1.5" to +2" could also lead to heavy
rainfall, depending if storms train and/or move very slowly.
Redevelopment of showers and storms seems probable over eastern
MN/WI Saturday afternoon/evening as another mid-level impulse and
cold front encroach the region. These features should push east into
the Great Lakes during Sunday, hopefully allowing for a dry finish
to the 4th of July weekend.

The first half of next week looks cooler and more comfortable with
highs in the mid to upper 70s. Prevailing zonal upper-level flow
will mean chances for weak waves to bring showers and thunderstorms
to the region throughout the first half of the week. But, timing and
location of the waves between models mostly leads to a smearing of
20-30% PoPs. Greater model divergence occurs later next week as
ensembles differ in the evolution of the upper-level pattern. The
EPS and Canadian ensemble favor troughing developing over the
eastern CONUS, which would place the Northern Plains in the upstream
(and drier) northwesterly flow. Meanwhile, the GEFS favors
continuing the zonal flow, leading to likely more rain chances the
latter half of next week. We will have to see which pattern evolves
and if we continue to be wetter than normal. Or, if we start drying
out like the last few summers.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1206 PM CDT Tue Jul 1 2025

No significant weather expected throughout the period with light
winds from 5-10kts decreasing below 5kts overnight, returning to
5-8kts at 240-270 later in the period. FEW050 for fair weather
cumulus possible this afternoon, with a sub 20 percent chance of
-TSRA as RWF/MKT overnight. FEW250 is expected after 02z due to
 upper level smoke that should move through by 08-10z. End of
 period could see -TSRA added in future TAFs, but it remain
 condition on where/when the storms form tonight.

KMSP...No additional concerns.

/OUTLOOK FOR KMSP/
THU...VFR, chc -TSRA/MVFR late. Wind SE 5-10kts.
FRI...VFR, chc TSRA/IFR pm. Wind S 10-15G25-30kts.
SAT...-SHRA/MVFR, chc IFR. Wind W 5-10kts.

&&

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

&&

$$

DISCUSSION...CTG
AVIATION...TDH