148
FXUS63 KMPX 041724
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1224 PM CDT Fri Jul 4 2025

.KEY MESSAGES...

- Hot and humid today with a Heat Advisory in effect for central
  MN and west central WI.

- Showers and thunderstorms are expected tonight into Saturday.

- Relief from the heat and occasional chances for thunderstorms
  next week.

&&

.DISCUSSION...
Issued at 329 AM CDT Fri Jul 4 2025

Showers and thunderstorms continue across parts of western WI
early this morning in response to a low level jet, moisture
convergence, and an instability gradient. SPC mesoanalysis
highlights enough bulk shear to organize a few of these cells to
severe limits capable of large hail. Otherwise, an axis of ~2
inch pwats extending across southern and western WI had allowed
for very efficient rainfall. Convection has been training
southeast as renewed development continues to the north. 6 hour
QPE ranges from 2 to 4 inches from eastern St. Croix County,
across Dunn and into southern Chippewa and Eau Claire counties.
There have been a few reports of flooded roads, but any
instances have been isolated. Convection is starting to wane and
this trend is likely to continue through the early morning
hours.

A warm front along the Mississippi River will lift north this
morning. Gusty south winds will develop mid morning while skies
clear. 925 mb temps in the upper 20s C should bring highs back
into the low 90s. It should be a degree or two warmer than
yesterday with better mixing, slightly warmer temps aloft, and
lower dew points. Nevertheless, heat indices will still reach
the mid 90s to lower 100s area wide. Expanded the Heat Advisory
across central MN and the rest of west central WI. This is where
winds are expected to be lowest, leading to higher WBGT values,
and where dew points will be highest.

Showers and thunderstorms will develop along a surface trough
and cold front across the Dakotas and northern MN this
afternoon. The front will inch eastward tonight and activity
should begin spreading into western MN this evening. A few
severe storms are possible with this activity, but as the night
wears on the atmosphere will begin to stabilize and as
convection continues eastward it should weaken. However, very
high pwats along the front, possibly nearing 2.25 inches, very
high freezing levels near 15kft, and MBE velocities of only 5
to 10 kts will allow storms to be rather efficient rain
producers. A low pressure center will ride northeast along the
slow moving front Saturday. Rounds of showers and thunderstorms
are expected near the front, especially in the afternoon with
diurnal instability increasing.

The front will push east Saturday night and the rest of the
weekend looks dry. West northwest flow aloft will bring a
return of near normal temperatures next week. Several weak
disturbances will bring periodic chances for showers and
storms. The EML is expected to remain west across the Rockies
and Plains, but lapse rates locally will be steep enough for
bouts of strong instability. There doesn`t appear to be one
particular period with higher confidence for widespread
convection, but a scenario similar to this morning`s with
localized clusters of thunderstorms and heavy rain are possible
through the week.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1203 PM CDT Fri Jul 4 2025

VFR conditions until a line of showers and thunderstorms from
the Dakotas travels east into western MN late this evening.
Terminals in western to central MN could experience stronger
storms with gusty winds and potentially large hail while
visibilities fall to MVFR. But, the activity should weaken as it
travels east overnight, reaching WI by about 11Z Saturday
morning. By this point, precipitation should likely be showers
but can`t rule out a thunderstorm, hence the inclusion of
PROB30s for -TSRA at RNH and EAU. Cigs should plummet to at
least MVFR once precipitation arrives with most terminals likely
seeing a brief reduction to IFR before cigs improve to MVFR by
late morning. South-southwesterly winds will gust to 20-25 knots
this afternoon but slow to near or just under 10 knots this
evening. Winds will increase slightly and become northwesterly
from west to east across MN Saturday morning after the frontal
passage occurs.

KMSP...Moved up rain`s arrival time to 10Z on Saturday morning.
Kept PROB30 for -TSRA for the first few hours of the rain`s
arrival as thunderstorms still look possible, though activity
will be weakening. Cigs should drop to MVFR (with bases near
1500 feet during heavier precip) once precip arrives.
Redevelopment of -TSRA is possible again early Saturday
afternoon before conditions improve to VFR later in the
afternoon.

/OUTLOOK FOR KMSP/
SUN...VFR. Wind NW 5-10kts.
MON...VFR. Wind SE 5-10kts.
TUE...VFR, chc MVFR/-TSRA. Wind W 5-10kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory until 8 PM CDT this evening for Anoka-Benton-
     Carver-Chippewa-Chisago-Dakota-Douglas-Hennepin-Isanti-
     Kanabec-Kandiyohi-Lac Qui Parle-McLeod-Meeker-Mille Lacs-
     Morrison-Pope-Ramsey-Scott-Sherburne-Stearns-Stevens-
     Swift-Todd-Washington-Wright-Yellow Medicine.
WI...Heat Advisory until 8 PM CDT this evening for Barron-Chippewa-
     Dunn-Eau Claire-Pepin-Pierce-Polk-Rusk-St. Croix.

&&

$$

DISCUSSION...Borghoff
AVIATION...CTG