Johnsburg, Minnesota Weather Forecast Discussion

989
FXUS63 KARX 211743
AFDARX
Area Forecast Discussion
National Weather Service La Crosse WI
1243 PM CDT Sun Sep 21 2025
.KEY MESSAGES...
- Scattered showers and thunderstorms possible through Monday.
  Some storms may become strong during the afternoon and evening
  hours, bringing primarily a risk for hail.
- Temperatures stay near normal with highs in the low to mid 70s
  through much of the upcoming week.
&&
.DISCUSSION...
Issued at 245 AM CDT Sun Sep 21 2025
A short reprieve in cyclonic gyres traversing the Upper Mississippi
River Valley limits local precipitation chances through this
morning. A tight cyclonic rotation over North Dakota on early
morning GOES water vapor imagery will reintroduce precipitation and
storm chances later today as a perturbation along its southern
periphery traverses the forecast area overnight. Initial storm and
precipitation chances reach our western peripheral counties in
southeast Minnesota this afternoon/evening, initializing on the nose
of a low level jet streak with sufficient instability (500+ J/kg)
accompanying the 60 degree surface isodrosotherm currently seen on
surface observations over southwest Minnesota. Overall impacts
will be dependent on lingering mid level warmer air and
associated weaker lapse rates with meager, albeit severe
sufficient, deep layer shear of 30kts from 0 to 6 km. Hail will
be the main hazard while damaging winds are not able to be ruled
out. Strong storms may continue overnight upon
re-intensification of the low level jet.
Little progress in the synoptic pattern and frontal boundary along
our western periphery through Monday persists strong to severe storm
potential locally. Similar to Sunday, overall limiting factor will
be meager, albeit severe storm capable, deep layer shear of
20-30 kts from 0 to 6 km.
Subsequent synoptic forcing through the work week will be a broad
upper level trough extending southwest to northeast across the CONUS
(LREF Probabilities) with todays aforementioned cyclonic rotation
lingering over the Great Lakes. Meager progressivity in the global
pattern suggests this setup is a precursor to an omega blocking
pattern through next weekend seen in long term global
deterministic models (GFS/ECMWF).
&&
.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1238 PM CDT Sun Sep 21 2025
Instability showers and storms may impact the TAFs briefly this
afternoon. Additional showers and storms along a cold front may
impact KRST late tonight and Monday morning. In the wake of
this front, there is at least an 80% probability that ceilings
will become IFR at KRST after 22.15z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...JAR
AVIATION...Boyne

NWS ARX Office Area Forecast Discussion