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FXUS63 KMPX 281951
AFDMPX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
251 PM CDT Sun Jun 28 2026
.KEY MESSAGES...
- Scattered thunderstorms are expected to develop this evening
along and north of the I-94 corridor. These storms will be
elevated, with an isolated risk for large hail existing.
- A line of strong to severe storms is expected to develop late
in the day on Monday in western MN, tracking east toward
Wisconsin through the evening.
- Long duration period of heat and humidity starts Monday. The
Extreme Heat Warning remains in effect for Monday. Counties
that were not initially in the Excessive Heat Warning were
placed in a Heat Advisory. Heat impacts will be felt all week
with little overnight relief and therefore a building heat
stress.
- Daily chances for thunderstorms through next week. Storms will
be capable of severe weather and torrential rain, if they are
able to form.
&&
.DISCUSSION...
Issued at 251 PM CDT Sun Jun 28 2026
The decaying MCS that moved across the region this morning did two
things. First, brought a much needed soaking rain area-wide and two,
it delayed the arrival of the tropical airmass, giving us one more
day of relative comfort before the heat and humidity really push in.
At 2pm, that warm from was near a Sioux City to Des Moines line and
won`t get up into southern MN until closer to sunset, so we did
pull back several degrees on highs for today.
Tonight, this warm front will continue to push north, with scattered
thunderstorms expected to develop north of the warm front. Exactly
when/where this next round of storms develops is uncertain, but it
looks to occur between 8pm and 10pm somewhere not far from the I-94
corridor. The greatest storm coverage is expected overnight north of
I-94 from east central MN, back into northwest and west central WI.
These storms will be elevated, but with MUCAPE in excess of 4000
j/kg, you can`t rule out a few storms being capable of producing
large hail, which is covered by the Marginal Risk in the Day 1
convective outlook.
Monday, a surface low will become occluded as it moves north across
the Dakotas. This will push the warm front up into northern MN, with
a very hot airmass overspreading the area. As we have been seeing
much of the summer, the NBM warm bias in the 48 hour + window is
slowly being corrected with time, with 100 degree highs now off the
map. However, we will still see highs well into the 90s, with
dewpoints uncomfortably finding their way up into the mid 70s. This
will create very dangerous heat conditions Monday afternoon, with
afternoon heat index values topping out in the 100 to 110 range. For
heat headline changes, we added Morrison County into the Excessive
Heat Warning, with any counties not in the Warning placed into a
Heat Advisory. For now, we continue to run this one-day at time to
see how convection influences temperatures through the rest of the
week.
As for those storm chances, we will see a strong cap move in behind
the warm front, with h7 temps on Monday surging to around +16C.
However, as the surface low moves into southern Canada Monday
afternoon, we will see a cold front push into western MN. At the
same time, the upper trough driving this system will push far enough
east to start nudging the EML and associated cap east as well, with
h7 temps along the SD border progged to drop below 12C around 00z (7
pm Monday evening). This will set the stage for convective
initiation along the cold front in western MN around that 7pm
timeframe. At this juncture, we`re leaning on what the AI versions
of the GFS and ECMWF shows, which would say the 12z NAMnest likely
has the best idea of what storms will look like later in the day on
Monday. The greatest severe risk Monday is definitely up in the Red
River Valley, but with MLCAPE progged to be in excess of 5000 j/kg,
any storms that form down here will have the potential to be severe.
Given the expected storm mode (linear) and very high freezing
levels, damaging wind gusts look to be our primary risk, with a
tornado or two being possible as well. The greatest severe risk
Monday looks to be west of I-35, with the Day 2 Slight Risk pretty
close to what our expectations are.
For the rest of the forecast through 4th of July weekend, ridging
will be the dominate player. That ridge will be centered over the
Tennessee Valley during the upcoming week, it will break down next
weekend, then intensify over the 4-corners region after the 4th.
Through all of this, the northern tier of the central CONUS will
remain on the periphery of the ridge, within the zone of enhanced
upper flow. A classic ring of fire pattern. The current expectation
is that the front that comes in Monday night will stall out over the
region as it runs into the upper ridge to the southeast. It is
expected that each day next week, we`ll see storms bubble up along
the boundary in the late afternoon/early evening. With Pwats never
far from 2" and MUCAPE always in excess 2000 j/kg, heavy rainfall
and severe weather will be a daily risk, it`s just a question of
where the boundary and any subtle shortwaves will be on a daily
basis. As of this afternoon, the front looks to likely be south of
us on Tuesday, but then drift back up over us Wednesday and
Thursday, when the NBM shows likely (over 55%) and even some
categorical (over 75%) PoPs during the overnight hours both days.
This same type of weather pattern will continue through the Fourth
of July, with high confidence in daily thunderstorms occurring, but
low confidence on where they will be between central Iowa and
northern MN. The one bright spot of all this potential activity is
that it does keep us out of the extreme category for heat, but
definitely still in the uncomfortable category, with daily highs
around 90, afternoon heat indices pushing 100, and lows struggling
to dip much below 70 thanks to the dewpoints frequently sitting
above 70.
&&
.AVIATION /18Z TAFS THROUGH 00Z TUESDAY/...
Issued at 121 PM CDT Sun Jun 28 2026
This forecast period has proven to be tricky especially
forecasting cigs. This morning`s wake low has left enough trailing
subsidence which has forced clearing across southwestern MN. Hi-res
guidance has handled this subsidence poorly. It is expected that
isentropic upglide should regain dominance and force scattered
to broken low VFR cu to develop this afternoon. There also is
another shot that our northern sites (AXN, STC, and RNH) see a
few scattered showers/thunder redevelop this afternoon.
Forecast soundings do prefer that the environment is capped
aloft however included prob30 mentions at these sites should any
cu manage to produce any precip.
As for winds, the highest wind gusts have moved east accompanied
with the wake low. Conditions will remain breezy out of the SE
this afternoon between 20-30kts then gradually be on the
decrease this evening. Winds then will shift southerly late
tonight into early tomorrow morning and increase once again with
gusts between 20- 30kts.
KMSP...Scattered low VFR cu this afternoon with breezy SE`ly gusts
between 25-30kts. Winds weaken this evening with cigs redeveloping.
At this time, low confidence exists if MSP manages to reach MVFR
cigs this evening vs. low VFR and scattered. Decided to keep the TAF
in low VFR at this time but lowered sky cover could be introduced in
future amendments based on trends. Kept precip mentions out of MSP
for now as higher confidence for any redevelopment of precip was
north of the field. Winds shift southerly tonight and increase back
to 25-30kts late morning/early afternoon.
/OUTLOOK FOR KMSP/
MON...VFR. Chc PM TSRA. Wind S 15-20G30 kts.
TUE...VFR. Wind SW 10-15G25 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory from 9 AM Monday to midnight CDT Monday night
for Chippewa-Douglas-Lac Qui Parle-Pope-Stevens-Swift-
Todd-Yellow Medicine.
Extreme Heat Warning from 9 AM Monday to midnight CDT Monday
night 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 Monday to midnight CDT Monday night
for Rusk.
Extreme Heat Warning from 9 AM Monday to midnight CDT Monday
night for Barron-Chippewa-Dunn-Eau Claire-Pepin-Pierce-
Polk-St. Croix.
&&
$$
DISCUSSION...MPG
AVIATION...Dunleavy
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