Flash Flooding and Hail in Minnesota, July 27, 2025

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
558 AM CDT Sun Jul 27 2025

.KEY MESSAGES...

- Heat and humidity intensify Sunday with highs in the upper
  80s to mid 90s and heat indices in the upper 90s to mid 100s.

- Unsettled weather resumes late Sunday and lasts through early
  next week. Severe storms are possible Sunday night and heavy
  rainfall is possible Monday night.

- Cooler and drier conditions later next week.

&&

.DISCUSSION...
Issued at 413 AM CDT Sun Jul 27 2025

Ridging will continue to build in from the west through the course
of today. A few pre-dawn storms are possible this morning as a mid-
level wave embedded within this ridge has already initiated
some convection over the eastern Dakotas and northwestern MN.
The most concentrated region of storm coverage this morning
should remain across northern MN although, there is a slight
chance that some of that convection reaches portions of west-
central MN.

As they say in the south, "its not the heat, its the humidity!" That
holds true for our forecast today which is why heat headlines exist
for all of central and southern MN and western WI. Typical warm
areas across western MN could make a run at the upper 90s should the
+30C h925 temps verify but as of now opt'd to run with NBM output in
the mid 90s. Areas elsewhere can expect highs at or about 90. The
driver for this extreme heat event are the widespread low to mid 70
dew points which in turn force heat indices this afternoon. Areas in
eastern MN and the St. Croix River Valley can expect a heat index at
our just above 100 degrees whereas 100 to 105 across western MN. Max
WBGTs will reach the upper 80s for most areas. Try and keep cool if
you can by ensuring to stay hydrated, wear light clothing, and limit
time outdoors. Also, suspended wildfire smoke will alert its
way eastward as it accompanies the ridge but some good news is
that it looks to be remain prevalent aloft. Thus surface
impacts to air quality look to remain null today.

As we this evening into the overnight hours, convection still looks
to be a favorable possibility. Flow aloft becomes westerly and
increases to about 40kts. Extreme instability of +3000 J/kg SBCAPE
will be in place. Residual boundaries that remain from the ongoing
convection across NW MN this morning will aid in parcel ascent and
ultimately drive CI again this afternoon along and north of the
I-94 corridor in western MN. Multi-cell lines are expected to
congeal into a SSE progressing QLCS which will provide primarily
a damaging wind threat, but with steep lapse rates of 8C, large
hail will also be possible. Lastly with 45 to 50kt effective
shear, a tornado or two also cannot be ruled out.

Sunday night's convection will setup the stage for Monday's
convective environment. A boundary will exist somewhere likely
over southern MN into WI and is progged to lift northward.
Tropical like PWATs exceeding +2" with a continuing unstable
airmass, and strengthening LLJ, additional CI is possible with
storms capable of producing heavy rainfall. The SPC has upgraded
portions of western MN to a slight risk of severe
thunderstorms. Forecast guidance still is trying to work out
where potential training storms could drop the highest QPF.
HREF 24-hr PMM through Monday evening favors areas across
eastern- central MN down to southeastern MN seeing potentially 3
to 4" of storm total rainfall. As for temperatures Monday,
things still remain hot and humid but not as impactful as
Sunday's heat threat. This heat will be dependent on any
existing convective contamination which would limit heating
potential.

As for Tuesday, the threat for thunderstorms will be focused along
N/IA border. As of now the SPC has maintained a marginal risk for
severe thunderstorms in that region given a frontal boundary is
forecast to pass through that area. Confidence remains low for exact
location impacts as there are a few spatial inconsistencies within
forecast guidance. Therefore, maintained lower mention of PoPs
Tuesday.

Cooler and drier air will follow for the rest of the week with
surface high pressure building in.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 558 AM CDT Sun Jul 27 2025

VFR with some MVFR/IFR fog possible this morning and have
maintained TEMPO groups where fog developed. Mostly clear skies will
transition to elevated surface smoke AOA 20kft this afternoon.
Likely TSRA is expected to sweep across sites from west to east late
tonight into the pre-dawn hours of Monday morning. Have adjusted
PROB30 timing accordingly to reflect trends in latest CAMs. Light
southerly winds will increase to between 10-12kts with gusts ranging
between 18-20kts across western sites this afternoon. Winds veer
northerly in the next TAF period.

KMSP...Fog possible this morning but likely should remain in the
river valley and not reach the terminals. Light southerly winds will
increase to near 10kts with a few gusts near 18kts through this
afternoon. Still keeping an eye on pre-dawn storms for early Monday
morning. Have pushed back timing another couple of hours in the
PROB30 grouping to reflect current trends with the latest CAMs.
Winds will begin to veer northerly by mid-morning Monday.

/OUTLOOK FOR KMSP/
WED...VFR. Chc MVFR A.M. -TSRA. Wind NE 5-10G15 kts.
THU...VFR. Wind E 5-10 kts.
FRI...VFR. Wind SE 5-10kts.

&&

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

&&

DISCUSSION...Dunleavy
AVIATION...Dunleavy

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
314 AM CDT Sun Jul 27 2025

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
280815-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa-
Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington-
Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota-
Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth-
Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Eau Claire-
314 AM CDT Sun Jul 27 2025

This Hazardous Weather Outlook is for portions of central and
southern Minnesota, and west central Wisconsin.

.DAY ONE...Today and Tonight.

Hot and very humid conditions arrive today. Extreme Heat Warnings
or Heat Advisories are in effect through early this evening.

Showers and thunderstorms are likely tonight, especially along
and north of I-94. Damaging winds are the main threat, but some
large hail and a tornado or two cannot be ruled out.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Additional thunderstorms are likely Monday night and Tuesday.
Heavy rainfall and some severe weather is possible.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter may be needed tonight and Monday night.