097
FXUS63 KMPX 291003
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
503 AM CDT Mon Jun 29 2026

.KEY MESSAGES...

- Very hot & humid today. Heat Index values of 100-110 degrees
  this afternoon with little cooling relief overnight.

- Low chance of thunderstorms this evening, but, if
  thunderstorms are able to develop they could become severe
  with heavy rain.

- Hot & humid weather continues this week, although not nearly
  as intense as today. Continued low chances for thunderstorms
  as well.

&&

.DISCUSSION...
Issued at 459 AM CDT Mon Jun 29 2026

Very hot & humid weather develops today as strong warm advection
continues over the Upper Midwest, in response to a deepening &
anomalously strong low over the Canadian Prairies. The ridging
aloft over the region peaks this afternoon with 700 mb
temperatures of 17C on the upper end of climatology for June &
July. There will be some stubborn low stratus to clear out this
morning across central Minnesota & western Wisconsin as rich
moisture gets trapped under the stout capping inversion, but
otherwise we should see plenty of sunshine today allowing for
temperatures to easily reach the low to mid 90s. The very muggy
dew points in the mid to upper 70s being advected in from Iowa
will limit any run at 100 degrees today, but this will only make
the heat index values worse as we are still expected to have
a "feels like" temperatures of 100-110 degrees for much of the
area this afternoon & evening.

The very hot & humid conditions will also create an explosively
unstable atmosphere with most-unstable CAPE values of 5000-6000
J/kg expected to develop this afternoon. To go along with the
extreme instability, seasonably strong wind shear values of
30-40 kts will be present across the region as the wind fields
strengthen in response to the deepening low to our north. This
is a high-ened environment for severe weather we`ll have over
the region this afternoon, BUT, the very strong capping of 15+
degrees C at 700 mb *should* limit any storm develop the Dakotas
& northern Minnesota.

Things change a bit late this evening, as a surface cold front
moves eastwards through the area & our temperatures aloft begin
to decrease. Some of the larger-scale global models are more
robust at initiating a line of convection along the front late
this evening & overnight as our 700 mb temperatures cool to
more reasonable levels. Instability values will be slightly
lower than this afternoon, but still very unstable, so any
storms that would be able to initiate tonight could likely
become severe with damaging wind gusts & heavy rainfall.
Meanwhile high- resolution models are much more sparse with
initiation along the front tonight, potentially picking up on
some sort of subsidence response to the intense convection
expected off to our north. It`ll be a classic conditional
summertime thunderstorm forecast:
probabilities are low (20-30%) that thunderstorms are able to
develop, but, the chance for severe weather & heavy rain is
high if they do. be sure to monitor forecast trends through this
afternoon & evening.

Tomorrow through the holiday weekend, we begin a stretch of
mostly similar days as the ridging aloft becomes entrenched
over the region. Hot & humid weather continues, although not
nearly as hot as today, with max heat index values of 90 to 100
degrees expected daily. Periodic chances for thunderstorms are
also present as a number of weak disturbances traverse
northwards around the ridge, and any of these thunderstorms
complexes could pose a threat for severe weather & heavy rain.
Models are widely scattered on resolving these impulses (as
expected) so precip probability forecasts are going to remain
very broad brushed, but we do look to have higher chances for
thunderstorms & heavy rain during the morning hours Tuesday &
Wednesday. These morning thunderstorm chances could also impact
our forecast temperatures as any day with morning precip & cloud
cover with have significantly cooler temperatures than
currently forecast. As for daily temperature trends, there is a
noticeable departure between the ECMWF & GFS suite of guidance,
with the ECMWF members trending much cooler midweek through the
weekend. ECMWF AI/ensemble/deterministic guidance suggests
we`ll see temperatures more in the mid to upper 80s while the
GFS members still depict highs in the 90s most days. Excessive
heat conditions with heat indices of 100-105 still look likely
again tomorrow afternoon across the metro & western Wisconsin,
but the heat threat looks more uncertain beyond that.

&&

.AVIATION /06Z TAFS THROUGH 12Z TUESDAY/...
Issued at 1224 AM CDT Mon Jun 29 2026

Scattered showers and storms will continue for the next few
hours across central MN north of I-94 and portions of western
WI. Activity will continue to lift northeast and out of the
forecast area by 08-09z. Skies remain BKN to OVC with CIGs at
2-5 kft leading to IFR and MVFR conditions at some of the
terminals. Skies for MSP, MKT, RWF are becoming FEW to SCT at
4-8 kft. Isolated instances of IFR to MVFR CIGs remain possible
through the overnight and early morning hours. AXN is the most
likely to see LIFR as CIGs drop to around 400 feet. RAP
forecast soundings at AXN show deep low-level saturation for
most of tonight so thinking mist/drizzle will occur into Monday
morning. Visibilities as a result will drop to at least 1 1/2sm.
Clouds should begin to lift and break apart after 12z Monday,
with VFR likely by the afternoon. Winds remain predominately out
of the S/SE at 10-15 knots, becoming 7-12 through the morning
hours. Winds will become gusty out of the south with sustained
winds around 20 knots and gusts to 30 knots during the afternoon
and evening.

KMSP...Isolated instances of MVFR CIGs through the morning. By
mid-morning timeframe, skies will continue to clear with VFR
conditions expected through the day. Winds generally light at
7-12 knots out of the SE through the morning, becoming gusty out
of south at 15-20 knots sustained with gusts to 25-30 knots.
There is a chance for -SHRA or -TSRA after 03z but confidence is
low so no mention in 06z TAF.

/OUTLOOK FOR KMSP/
TUE...VFR. Wind SW 10-15G25 kts.
WED...VFR. Chc -TSRA. Wind SW 10-15G25 kts.
THU...VFR. Chc PM -TSRA. S 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory from 9 AM this morning to midnight CDT tonight
     for Chippewa-Douglas-Lac Qui Parle-Pope-Stevens-Swift-
     Todd-Yellow Medicine.
     Extreme Heat Warning from 9 AM this morning to midnight CDT
     tonight for Anoka-Benton-Blue Earth-Brown-Carver-Chisago-
     Dakota-Faribault-Freeborn-Goodhue-Hennepin-Isanti-Kanabec-
     Kandiyohi-Le Sueur-Martin-McLeod-Meeker-Mille Lacs-
     Morrison-Nicollet-Ramsey-Redwood-Renville-Rice-Scott-
     Sherburne-Sibley-Stearns-Steele-Waseca-Washington-
     Watonwan-Wright.
WI...Heat Advisory from 9 AM this morning to midnight CDT tonight
     for Rusk.
     Extreme Heat Warning from 9 AM this morning to midnight CDT
     tonight for Barron-Chippewa-Dunn-Eau Claire-Pepin-Pierce-
     Polk-St. Croix.

&&

$$

DISCUSSION...ETA
AVIATION...LPR