042
FXUS63 KMPX 031750
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1250 PM CDT Thu Jul 3 2025

.KEY MESSAGES...

- Heat and humidity build as we head into the holiday weekend.
  Heat Advisory issued in western MN today, and for the Twin
  Cities metro on Friday.

- Showers and thunderstorms are expected late Friday into
  Saturday.

- Relief from the heat going into next week with no strong
  signal for anomalous temperatures.

&&

.DISCUSSION...
Issued at 315 AM CDT Thu Jul 3 2025

It is a relatively quiet morning across the Upper Midwest as an
upper ridge continues to gradually shift east. Parts of western
MN are expected to warm considerably, especially near Lac Qui
Parle and Yellow Medicine counties where a Heat Advisory has
been issued for today. Heat indices will likely rise above 100F
in these counties due to warm highs and dewpoints in the low to
mid 70s. Isolated cases of near 100F also look possible along
the MN river valley if we are sunny enough throughout the day,
but confidence and widespread coverage are too low to include in
the Heat Advisory for today. It will be hot and humid area
wide, similar to yesterday if not a couple of degrees warmer.
This heat will allow MUCAPE values in excess of 2000 J/kg to
build today, priming another chance for afternoon/evening
storms. Coverage should tend to be limited until aided by modest
low level WAA during the evening/night, spreading from SE MN up
into western WI. Should storms develop, the unstable airmass
could support an isolated threat of severe hail and wind.

A warm front will continue to lift north into Friday, shifting
the axis of hot and humid air eastward. Widespread heat
indices well into the 90s looks likely, prompting concern for
the metro in particular. We have issued a Heat Advisory for the
7 metro counties given their criteria is 95F+. Adjustments may
need to be made should the forecast trend upwards. We saw
temperatures on the high end of the forecast yesterday thanks to
the persistent sunshine, and the deterministic NBM is still on
the low side of the forecast. To account for this, we have
blended half NBM and half NBM50. A closer push to the 50th
percentile may be needed if highs are on the high end of the
forecast again today. Much of the day should remain dry until
better synoptic forcing develops in the form of a cold front. We
are just starting to get into the range of the hi-res models,
and there is pretty solid agreement for convection to move into
western MN during the late evening (close to 10pm). The main
threats look to be heavy rainfall and frequent lightning, which
will be important for those who may be traveling into western or
northern MN to keep in mind. Based on the timing, the line
could be in a weakening phase as it progresses eastward
overnight. Storms may reignite Saturday along the boundary, but
should be more scattered in nature. Modest shear of ~25 knots
will be in place, which would be sufficient for isolated cases
of severe wind, as highlighted by the Marginal (1 of 5) risk
issued by SPC. Thanks to the frontal passage, we can also expect
some relief from the heat Saturday onwards.

Next week, ridging starts to build out west again. A shortwave
riding down the eastern edge of the ridge could provide our
next period of active weather, likely some time Tuesday based on
long range ensemble guidance. That said, QPF does not stand out
with only a half inch or so on the high end of the forecast.
Confidence drops off quickly for the rest of the week, with no
strong signal for precip or anomalous temperatures.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1228 PM CDT Thu Jul 3 2025

VFR conditions are expected throughout the period. Hi-res models
have increased the chances for thunderstorms for
southern/eastern Minnesota and western Wisconsin this evening,
but they appear to be very scattered in nature. Have opted to do
PROB30s since there is high uncertainty on whether or not they
will become widespread enough to impact any of the terminals. By
late tomorrow morning, winds shift to the south/southwest with
gusts around 20kts.

KMSP...As mentioned above, threw in a PROB30 for thunderstorms
between 00-04z. Should be able to narrow down that time line by
the 21z AMD. Otherwise, winds go south/southwesterly tomorrow
afternoon with gusts around 20kts.

/OUTLOOK FOR KMSP/
SAT...-SHRA/MVFR, chc IFR/TSRA. Wind SW 5-10kts.
SUN...VFR, chc -TSRA/MVFR PM. Wind NW 10kts.
MON...VFR. Wind SE 5-10kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory until 8 PM CDT this evening for Lac Qui Parle-
     Yellow Medicine.
     Heat Advisory from noon to 8 PM CDT Friday for Anoka-Carver-
     Dakota-Hennepin-Ramsey-Scott-Washington.
WI...None.

&&

$$

DISCUSSION...BED
AVIATION...Dye