633
FXUS63 KMPX 310815
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
315 AM CDT Fri Jul 31 2026

.KEY MESSAGES...

- Heavy rain continues through the first half of the day across
  southwestern and southern Minnesota. Rainfall swath of 2-4",
  along with localized rainfall amounts in excess of 4"+ may
  result in flooding.

- Pleasant weekend ahead, with comfortable Summer temperatures
  and mostly sunny (at times hazy/smoky) skies.

- Isolated to scattered storm chances return early next week.

&&

.DISCUSSION...
Issued at 315 AM CDT Fri Jul 31 2026

HEAVY RAIN TODAY...It`s quite the soggy start to Friday across west-
central and southern MN, where MPX radar imagery captures an
expansive shield of moderate to heavy rainfall. Driving the
precipitation is a stacked upper-wave that is progged to mature
into a closed upper-low as it digs southeast from the Dakotas
into Iowa today. At the surface, cyclogenesis is underway across
eastern South Dakota and guidance depicts the low sliding to
the southeast through central Iowa by midday. Such an evolution
places the western & southwestern portions of MN in a zone
favored for a one-two punch of warm advective precipitation (as
we`re seeing early this morning) and a heavy deformation band of
rainfall that will develop on the northern side of the mid-
level low and prolong the heavy rain threat through the morning.
Combine the synoptic forcing with an environment primed for
efficient rainfall owing to skinny CAPE, a very deep warm cloud
layer, rich PWATs (2+"), and slow storm motions and the pieces
are in place for a flood threat. The overall theme in the 00z
CAM guidance supports the going forecast, with a wide swath of
2-4" of rain along and near the MN River and a narrow, more
localized swath of amounts exceeding 4" -- it`s very possible a
few locations measure upwards of 6" for a storm total! With this
in mind, our eyes are on the flash flood indicators early this
morning. 2 AM MRMS data illustrates that locations across Chippewa
County, MN have likely already observed 3-4" with rain ongoing.
Our Flash Flood Watch remains in effect for all counties south
of a Swift to Meeker line. The majority of the Watch will expire
at noon, however we`ve followed timing trends in the CAMs and
opted to extend the Watch until 4 PM for the southern two tiers
of counties along I-90. As noted in WPC MPD #901, dry antecedent
soils should work to mitigate the overall flood threat, however
the long duration nature of the moderate to at times heavy rain
certainly bears watching.

For those in the Twin Cities Metro, the forecast remains largely
unchanged, as a sharp cut-off in rainfall amounts is expected from
the southwest portion of the Metro (Carver/Scott) to the northeast
(Anoka/Washington). We`ve observed a slight northerly shift in some
of the latest CAM guidance (the last several runs of the HRRR in
particular). Should these solutions come to fruition, it`s possible
that more of the Metro could observe amounts closer to or exceeding
an inch, but again these chances would favor communities to the
south and west of the immediate Twin Cities Metro. Rain will end
from northwest to southeast as the surface low departs towards
eastern Iowa this afternoon. One other note, we have boosted
winds across southern MN this afternoon as near term guidance
is more aggressive featuring 35-40 mph gusts in response to the
strengthening system.

NICE WEEKEND WEATHER...By Saturday, the well-defined closed upper-
low is forecast to take residence over the Ohio Valley. Ridging will
expand east across the northern CONUS, which supports a quiet weekend
forecast for the Upper Midwest. Forecast highs are in the upper 70s
to lower 80s Saturday & Sunday, with the anticipation of mostly
sunny skies overhead. It`s possible that the skies may appear
hazy at times due to wildfire smoke present in the upper-levels
of the atmosphere, however impactful surface smoke is not
anticipated at this time.

STORM CHANCE EARLY NEXT WEEK...A progressive shortwave supported by
an active Pacific jet is forecast to traverse through central
Canada early next week. The majority of the upper-level forcing
associated with this feature will slide north of the Upper
Midwest, however a trailing cold front is forecast to move
across the Dakotas into MN later Monday into Tuesday. Early
indications are that moisture return ahead of the front may be
lacking, so it`s not surprising to see NBM only feature 40-60
PoPs across western MN that lower to 20-30 PoPs in eastern MN
late Monday night. Of note, several of the AI severe weather
forecast tools highlight northwestern MN (where NBM`s PoPs are
higher) for a chance of stronger storms, which makes sense given
proximity to the upper-forcing. We`ll keep an eye on this
through the weekend. The front is forecast to sag south Tuesday
and may force new convection across southern MN in the afternoon.
Drier weather returns by way of high pressure for the middle of
next week.

&&

.AVIATION /06Z TAFS THROUGH 12Z SATURDAY/...
Issued at 1245 AM CDT Fri Jul 31 2026

A slow moving area of rain with embedded thunderstorms is
ongoing early this morning across southwestern Minnesota.
MVFR/IFR cigs will persist with this activity through early
afternoon. There may be brief periods of LIFR conditions for
KRWF and KMKT where the axis of heaviest precip lies this
morning. Biggest change for this TAF set was to increase wind
speeds for all, but especially KRWF and KMKT. Hi-res guidance
suggests that gusts of around 25-30kts are likely through the
Minnesota River Valley southward. Rain will gradually taper off
by mid afternoon from west to east with VFR cigs returning by
this evening. Winds go northerly at around 5-10kts.

KMSP...Adjusted the start time of the -SHRA to be a little
earlier based on radar trends. Also added a TEMPO group for
lower vis with heavier rain for this morning. A few showers may
persist into the mid afternoon, but VFR conditions are expected
by late afternoon/evening. Winds will shift from southeasterly
this morning to northeasterly this afternoon with gusts around
20kts.

/OUTLOOK FOR KMSP/
SAT...VFR. Wind N 5-10 kts.
SUN...VFR. Wind ESE 5 kts.
MON...VFR. Wind SSE 5-10 kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Flood Watch until noon CDT today for Brown-Chippewa-Kandiyohi-
     Lac Qui Parle-Le Sueur-McLeod-Meeker-Nicollet-Redwood-
     Renville-Sibley-Swift-Yellow Medicine.
     Flood Watch through this afternoon for Blue Earth-Faribault-
     Freeborn-Martin-Steele-Waseca-Watonwan.
WI...None.

&&

$$

DISCUSSION...Strus
AVIATION...Dye