679
FXUS63 KMPX 111059
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
559 AM CDT Fri Sep 11 2026

.KEY MESSAGES...

- A few thunderstorms will develop late this afternoon and
  tonight, primarily north of I-94. There is a level 2 out of 5
  risk for severe thunderstorms.

- Widespread rain arrives Monday, but forecast rain amounts have
  trended lower.

- Turning much cooler this weekend and next week with highs in
  the 60s to low 70s.

&&

.DISCUSSION...
Issued at 251 AM CDT Fri Sep 11 2026

Clear skies are present across the Upper Midwest early this
morning. Clouds will increase today as a disturbance over
northern WY currently ejects eastward to the northern Plains
and Upper Midwest by this evening. Models indicate this wave
will weaken with time with the best forcing remaining across
northern MN. However, a LLJ will strengthen through the day to
45-50 kts overhead/across the warm sector and a narrow plume of
higher pwats (~1.5 inches) will be present just ahead of a
surface cold front. That, in combination with fairly steep mid
level lapse rates around 7.5 C/km, will lead to around 2000 J/kg
of MLCAPE. Capping will be weakest across western and northern
MN which is where storms are expected to be most numerous
(especially with northern extent where height falls will be more
impressive) late this afternoon and early evening. Bulk shear
around 40 kts would allow for supercell development. Large hail
and damaging winds are the primary threats, although the
strengthened LLJ will increase SRH to the point where a few
tornadoes are also possible. Storm development south of I-94
appears improbable with the exception across far western MN due
to greater capping and weaker forcing. However, maintained 20
PoPs in these areas for the potential that some of the initial
activity is maintained into the late evening hours. The
increasing LLJ throughout the day will also lead to gusty
southerly winds as mixing depth maximizes. Some gusts exceeding
40 mph are likely across central and southern MN.

Zonal flow will follow for Saturday, and by Sunday, a short
wave will rotate southeast across MN into WI. This may bring a
chance of showers across southern MN into IA and SD, but dry
high pressure to the north will limit the northern extent of any
precip. The high will slide east to the Great Lakes Sunday night
and warm air advection will begin across the Upper Midwest as a
potent trough advances into the northern Plains. Very strong
moisture advection will be brought on by a 50-55 kt LLJ Monday
and pwats are expected to increase to around 2 inches.
Isentropic lift will allow widespread showers to develop across
the region, but the trough will swing through quickly and limit
the residence time of the activity. In addition, the surface
warm front will remain well to the south across southwestern IA
and keep the more efficient thunderstorms anchored there. Models
have trended down on QPF locally from the 2-3 inches progged a
couple days ago. Given the lift and moisture in place, still
thinking an inch is not unreasonable on a widespread basis with
heavier amounts south and lighter amounts north, but this is
shaping up to be another disappointing event in the fight
against the drought.

For the rest of next week, zonal flow will continue with mid
level ridging remaining anchored in place across the south. A
nearly stationary front will draped from the central Plains to
mid Mississippi Valley and will keep the hot and humid air well
to the south. It will also act as a focus for numerous rounds of
showers and thunderstorms. At this time the odds of being under
the influence of dry high pressure outweigh the prospects of
any significant rain near the front. Following the cold front
tonight, we`ll remain in a definitively cooler pattern. This not
to say we won`t hit 80 again at some point into early/mid
October, but this front appears to mark the beginning of fall
weather for the Upper Midwest.

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 555 AM CDT Fri Sep 11 2026

No major changes to the 12z TAF set. Another hour or two of
LLWS possible at the western MN terminals. Focus then shifts to
strong southerly sustained winds between 15-20kts and gusts
upwards of 30-35kts for much of the daylight hours. Thunderstorms
are possible across portions of central MN this evening ahead
of a frontal passage, so have maintained PROB30s for -TSRA at
AXN & STC. A few of the latest hi-res members illustrate convection
developing across western WI as the low-level jet intensifies
tonight. Not ready to add a shower or storm mention into the
RNH/EAU TAFs, but a PROB30 may be needed at 18z. Speaking of the
LLJ, did include another round of LLWS at MKT, MSP, RNH, & EAU
as the LLWS strengthens heading into early Saturday morning.
This round of LLWS will not be as prolonged as a frontal passage
will turn the winds out of the WNW towards the end of the
period.

KMSP...Strong southerly winds dominate the forecast today.
Gusts upwards of 30-35kts likely late morning through the
afternoon. Winds decrease slightly this evening, however a
strengthening low-level jet will increase LLWS concerns after
sunset. Potential for showers & thunderstorms at MSP remains
too low to include mention in the 12z TAF, but the convective
environment will need to be monitored for potential mention in
later TAFs. Window for a shower or storm is ~3-6z.

/OUTLOOK FOR KMSP/
SAT...VFR. Winds NW 5-10G20kts.
SUN...VFR. Slight Chc -TSRA/MVFR. Wind NNW5-10kts.
MON...RA/MVFR expected, chance TSRA/IFR. Wind SE 15G25kts
becoming SW.

&&

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

&&

$$

DISCUSSION...Borghoff
AVIATION...Strus