Chaska, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

146
FXUS63 KMPX 081721
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1221 PM CDT Tue Jul 8 2025

.KEY MESSAGES...

- Quiet weather through Wednesday. Some patchy fog this morning
  with an isolated shower possible in WI this afternoon.

- Showers and thunderstorms return Thursday night and Friday.

&&

.DISCUSSION...
Issued at 323 AM CDT Tue Jul 8 2025

Some patchy fog has developed overnight across parts of central
MN. It hasn`t been persistent in most locations, which points to
an unlikelihood of becoming widespread and dense. Light
southwest winds are also helping it struggle to develop further.
Any remaining fog by dawn will quickly burn off and fair wx cu
will form late morning. Modest surface-based instability over
Wisconsin could foster development of this cu into showers or
isolated thunderstorms this afternoon.

Tonight and Wednesday will be tranquil with surface high
pressure in place. Off to the west, upslope flow across the high
Plains with passing mid level disturbances should initiate
convection over the western Dakotas Wednesday afternoon. This
activity will continue east on the leading edge of an EML and
eventually on the nose of a strengthening LLJ Wednesday night.
Most guidance dives this convection southeast into western Iowa
overnight, but it`s possible some showers and storms could
overspread parts of southern and western Minnesota. The
evolution of that could play into Thursday`s chances for
convection. It appears the overnight activity should keep the
surface front suppressed to the southwest for much of the day,
with warm air advection and a persistent LLJ likely keeping
convection active across Iowa. By Thursday night, a shortwave
trough over the central Plains will lift northeast while a
larger trough over the northern Rockies/northern Plains begins
to approach from the west. This should lead to thunderstorm
chances increasing farther north in our area, but as is typical
with convective events, confidence is generally low at this
range and mesoscale details will ultimately determine the
outcome. Nevertheless, the two troughs will interact and
eventually phase with each other over the Upper Midwest Thursday
night and Friday when thunderstorm chances increase. Pwats
nearing 2 inches and synoptic forcing with the trough should
lead to widespread showers and storms and the risk for heavy
rainfall. QPF on some guidance is quite impressive, especially
from those that develop slow-moving MCVs from remnant
convection.

The trough will kick east for the weekend. After a cool Saturday
in the 70s, some ridging returns early next week with temperatures
returning to near or just above normal levels.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1218 PM CDT Tue Jul 8 2025

VFR through the period with no precipitation expected. Winds
generally light and from the NW, becoming more N/NE by Wednesday
afternoon. It is possible we see another morning with isolated
patches of fog, but confidence on that is low and have left out
of the TAFs for now.

KMSP...Scattered CU expected to develop this afternoon.
Otherwise, no concerns.

/OUTLOOK FOR KMSP/
WED...VFR. Wind N 5kts.
THU...VFR, chc -TSRA overnight. Wind S 5-10kts.
FRI...SHRA/TSRA likely. Wind SW 5-10kts bcmg W 10-15kts.

&&

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

&&

$$

DISCUSSION...Borghoff
AVIATION...PV