364
FXUS63 KMPX 090820
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
320 AM CDT Wed Jul 9 2025

.KEY MESSAGES...

- Dry and warm today, with the chance of showers and thunderstorms
  across southwestern Minnesota overnight.

- Marginal Risk (1/5) for strong to severe thunderstorms Thursday
  afternoon into early Friday.

- Widespread soaking rain and storms continue Friday.

&&

.DISCUSSION...
Issued at 320 AM CDT Wed Jul 9 2025

Today and Tonight...Our Wednesday begins on quiet and comfortable,
with temperatures in the low to mid 60s. We have not seen much
in the way of fog up until this point, however as temperatures
cool under clear skies it remains plausible that patchy ground
fog develops here and there through daybreak. It`ll be warm (mid
80s) and sunny for most locations today as the Upper Midwest
remains under the influence of Great Lakes high pressure, which
will also work to keep humidity levels in check. The exception
will be across southwestern MN, where heat (upper 80s) combines
with increasing humidity (dew points in the upper 60s). It`s
these locations that will be the first to potentially see the
return of active weather in the shape of showers and
thunderstorms late tonight.

Early morning upper air analysis reveals a dominate ~594dm ridge
over the SW CONUS with troughing over the Great Lakes. Water vapor
captures ongoing convection across the north central Plains, which
appears to be tied to the low-level jet. This jet will push a warm
front east across the Dakotas, which will serve as a focus point for
new convection as a mid-level impulse pushes east across the flow
today. It will take some time before any convection approaches western
MN and it should be mentioned that CAM solutions offer a rather
murky view into how things may unfold. In general, any convection
that develops should strengthen into the evening in response to
the nocturnal low-level jet, which will be positioned farther
east tonight. A smoothed solution from the HREF displays a narrow
axis of strong instability across the eastern Dakotas/into southwest
MN. Would tend to think of the eastern axis of instability as
the "tracks" for one or two clusters of storms to traverse into
early Thursday morning. Additionally, HREF does keep ~1500 J/kg
of MUCAPE in place across western MN well into the night. With
this in mind, we have collaborated with neighboring offices to
raise PoPs above the NBM to ~30-40% along and west of a line
from Pope to Freeborn counties. The potential for these storms
to be severe is low given a very weak shear.

Wet Weather to End the Work Week...The main drivers of the forecast
through the end of the week will be a shortwave trough moving across
the Great Plains today into tonight, a stronger vort max moving
across southern Canada, and the eventual phasing of these two
features Friday into Saturday. Despite the complexity of the
forecast, confidence is high in the return of widespread
precipitation chances Thursday night through Friday. The
evolution of tonight`s convective episode will have impacts on
boundary/frontal placement heading into Thursday. However, the
atmosphere should recover and allow for some airmass thunderstorms
Thursday afternoon. A better chance for showers and storms will
arrive later Thursday night as the shortwave trough advances
east and ascent increases. Given strong instability, isolated
instances of damaging wind and hail will be possible across
western MN through the early morning hours of Friday -- though
from a severe weather perspective, locations western across the
Dakotas will have a higher threat with over these next few days.
The nocturnal timing and weakly sheared environment will limit
a greater risk.

Phasing of the initial shortwave trough into the the northern vort
max will be the driver of more widespread rain and thunderstorm
chances on Friday. Guidance displays an atmosphere conducive for
heavy rain, with PWATs nearing the 90th percentile of sounding
climatology (>1.5"). Consensus blend shows the potential for 1-1.5"
across eastern MN/western WI by the time all is said and done,
however there are still some heavier solutions on the table tied to
more convectively driven rainfall rates. We will likely have
numerous clusters of rain and storms ongoing Friday, along with
the potential for an MCV to develop and spin through the region
(further enhancing the heavy rain potential). We`ll lean on
upcoming CAM guidance to try and tighten the forecast up.

Weekend and Beyond...Dry weather will return for much of the weekend
following the passage of a cold front Saturday morning. Temperatures
are forecast to be in the upper 70s to lower 80s Saturday and then
climb into the mid 80s Sunday and Monday. The warming trend is tied
to increasing warm advection ahead of the next storm system that
aims to send a cold front/precipitation chances through the Upper
Midwest on Tuesday/Wednesday.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1150 PM CDT Tue Jul 8 2025

Terminals aim to stay VFR through the 6z TAF period. Light
winds and clear skies through daybreak may promote the
development of patchy ground fog. However, surface dew point
depressions are slightly greater than recent mornings, so plan
is to continue without visibility reductions in the 6z TAF set
and then AMD as necessary should a more notable fog scenario
unfold through the night. Winds between 5-10 kts through the
afternoon, with diurnal Cu around ~5kt feet.

KMSP...No additional concerns at this time.

/OUTLOOK FOR KMSP/
THU...VFR. SHRA/TSRA likely late night. Wind S 10-15kts.
FRI...SHRA/TSRA likely. Wind SW 5-10kts bcmg WNW 10-15kts.
SAT...VFR. Wind NW 10-15 kts.

&&

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

&&

$$

DISCUSSION...Strus
AVIATION...Strus