899
FXUS63 KMPX 301203
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
703 AM CDT Thu Jul 30 2026

.KEY MESSAGES...

- A corridor of heavy rain expected along the MN River Valley in
  SW Minnesota, starting this evening and continuing overnight.
  Localized flooding possible, especially in low-lying areas.

- Very nice weather this weekend, with milder temperatures,
  light winds, and sunny skies expected.

- Smoky skies continue at times, but the chance for surface
  smoke impacts appears low.

&&

.DISCUSSION...
Issued at 302 AM CDT Thu Jul 30 2026

Today...Regional IR satellite imagery shows convection ongoing
across the Dakotas and northern MN early this morning. Some
showers may continue into western or central MN, though upper
level forcing will taper off and allow most places to remain dry
until later today.

As the mid-level shortwave amplifies overhead this afternoon,
surface cyclogenesis off the lee of the Rockies will be the
trigger for scattered convection over a relatively broad area
across the central and northern Plains. A couple thousand Joules
of MUCAPE and about 35 kts of bulk wind shear may support
isolated supercells or mature line segments capabale of severe
winds. This would primarily be during the afternoon and evening
with the initial round of storms across the Dakotas and parts of
western MN.

Through the evening, storms will likely become more stratiform
and overspread across a larger area as the main lobe of 500mb
vorticity moves through SW MN. Low-level winds also increase
overnight, wrapping moisture around the low pressure center. At
the same time, you have some sense of a TROWAL/fgen forcing on
the northern edge of the low, almost similar to what we see with
a number of our strong winter low pressure systems. "Imagine if
this was all snow" is fair to bring up, but we`ll save that for
another day as we have more important business to attend to.
Forecasting QPF is often a very humbling thing, especially in
these convective scenarios. Not everyone is going to see 4+
inches of rain, but there certainly is a good signal that some
areas will. Both physical and computer based guidance have
focused in the MN River Valley (roughly from Granite Falls to
Mankato) as the likely corridor for pockets of the heaviest
rainfall amounts. This is the area where the deepest moisture
overlaps with the greatest vorticity aloft. A Flood Watch was
contemplated, however, given 1) the very dry antecedent
conditions, 2) the slow-moving nature of this system (rain falls
over a longer period rather than training storms or a very
intense MCS), and 3) the greater capacity of mature farmlands
out in those areas, we felt that any flooding will likely be
localized to any fast responding creeks and streams or low-
lying areas. That said, always remember to Turn Around, Don`t
Drown when encountering any flooded roadways.

The amount of rainfall outside of this corridor is more
uncertain and largely dependent on individual storm tracks or
persistence of the stratiform rain Friday morning. Also not
dissimilar to winter systems, we will likely have some influence
from drier air with winds turning out of the northeast along and
north of the I-94 corridor (including St Cloud and the Twin
Cities metro into western WI). Although in this case, the "drier
air" still has a pool of 1" PWATS. It will take a lot of bad
luck for these areas to not see ANY rain, though history is
certainly not on our side for the way this summer has gone. Both
STC and MSP airports are staggeringly in the red for
precipitation through the year so far. As of yesterday, STC`s
precip departure from normal (1991-2020) is -3.72", and MSP`s
is -4.35". EAU is doing a little better, but still 1.00" behind
normal as well.

Somewhat of an interesting evolution with the recent CAMS is
that we may see additional storm development along the frontal
boundary of the dry and moist airmasses Friday
afternoon/evening. This may provide a better chance for rain in
the areas that miss out on the heaviest amounts Thursday night
and Friday morning, especially in a solution similar to the 7/29
18z run of the RRFS.

This Weekend...Saturday and Sunday continue to look like great
days with mostly sunny skies and temperatures in the low to
mid 80s each afternoon.

Next Week...Winds shift out of the south as a strong low
pressure system develops across northern Saskatchewan and
Manitoba. A cold front will likely drape across the northern
Plains and spark a round of storms Monday into Tuesday. A
corridor of moist and unstable air will develop out ahead of the
front, and if paired with enough vertical shear, could produce
a zone for organized convection. The timing may end up being a
limiting factor for any severe weather in the Upper MS Valley,
however, as the front is currently favored to end up moving
through overnight while instability decreases. Storm chances
may persist into Tuesday afternoon, but invading high pressure
will result in quieter weather for the middle of the week.

&&

.AVIATION /12Z TAFS THROUGH 18Z FRIDAY/...
Issued at 653 AM CDT Thu Jul 30 2026

Mid and high level clouds continue to increase today as our next
round of showers and storms develop across the central and
northern Plains today. Several hours of scattered to widespread
showers are expected to spread west to east tonight into Friday
morning. Some storms will be embedded within the showers,
especially during the evening and early morning hours as rain
first moves in.

KMSP...KMSP will likely be on the northern edge of the heaviest
rain, though several hours of -SHRA still look likely starting
around 10z. We could see some TSRA in the showers, especially
when heavier rain moves in around 12-15z.

/OUTLOOK FOR KMSP/
FRI...Chance AM MVFR/-TSRA. Wind NE 5-10kts.
SAT...VFR. Wind N 5-10kts.
SUN...VFR. Wind. SE 5-10kts.

&&

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

&&

$$

DISCUSSION...BED
AVIATION...BED