St. Paul, Minnesota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

074
FXUS63 KMPX 171802
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
Issued by National Weather Service La Crosse WI
102 PM CDT Thu Apr 17 2025

.KEY MESSAGES...

- Today, strong to severe thunderstorms possible this afternoon
  through this evening. Large hail is the primary threat.
  Localized heavy rain, damaging wind, or an isolated tornado
  can`t be ruled out.

- Additional rain chances Sunday into early Monday, and again
  Tuesday of next week, but no significant weather impacts are
  expected.

&&

.DISCUSSION...
Issued at 244 PM CDT Wed Apr 16 2025

TODAY...Thunderstorms are expected to develop this afternoon and
last into the evening. A few storms could be strong to severe,
especially in southern Minnesota. The main threat is large hail,
but heavy rain, damaging winds, and an isolated tornado can`t be
ruled out.

It was a dry and breezy morning, with dewpoints in the upper
20s to lower 30s,and winds out of the southeast at around 10 to
15 mph. That will change later today as a strong low level jet
will develop and advect moisture northward across the region.
Meanwhile southwest flow aloft has already brought an elevated
mixed layer across the region, with 500-700mb lapse rates around
7.5 to 8.5 C/km already in place across as shown via the SPC
Mesoanalysis page. The addition of low level moisture, together
with afternoon heating will lead to around 1000 to 2000 J/kg of
MLCAPE within in inverted surface pressure trough extending up
from Iowa into central Minnesota.

Storms are expected to develop this afternoon, and move
eastward this evening. Hodographs still show an elongated wind
profile, but there is veering in the lowest 3 km, and one could
argue that forecast soundings are more supportive of surface-
based storms than they were yesterday. For that reason, large
hail is still the primary threat, but damaging and an isolated
tornado can`t be ruled out.

In addition to the severe threat, PWAT values will approach 1.1
to 1.3 inches, which is near record territory for mid-April.
Although the storms will be moving east, any storms that train
over the same area could dump 2 to 3 inches or more of rain over
an isolated area, which is supported by some of the individual
HiRes solutions. Since we have been fairly dry, the risk for
excessive runoff is low, so the flood risk would primarily be
for urban areas.

FRIDAY THROUGH WEDNESDAY...Lingering rain showers will last into
Friday before the system departs. Cooler and drier air will
follow into Saturday, with highs only in the low to mid 50s. On
Sunday, a shortwave trough over the Texas panhandle is forecast
to move up toward the Great Lakes. Widespread rain is expected
with this system. A westerly track would bring this rain across
Minnesota and Wisconsin, while an easterly track would only
bring rain to Wisconsin. Ensemble guidance off the ENS is
farther west, and the GEFS is farther east. The blended guidance
with highest rainfall chances east of I-35, and lesser amounts
to the west, seem appropriate. Forecast confidence in this
system should increase over the next couple of days.

Lastly, there is another shortwave expected to move through
Tuesday into Tuesday night. This will bring additional rain
chances, but it will be moving through quickly. There is a small
chance that we could build enough instability for storms, but at
this point it looks like rather low impact weather for next
week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 102 PM CDT Thu Apr 17 2025

Showers and storms will be the main TAF consideration through
the afternoon and evening as much of the CAMs develop a line of
storms between 20z to 22z across south-central MN. These will
progress eastbound throughout the evening hours with periods of
IFR vsbys likely in heavier storms. Earlier development
continues to move through portions of western WI this afternoon
which is currently impacting the KEAU TAF site with MVFR vsbys
possible. After the main line of storms exits, a cold front will
sweep through the area late evening and overnight, veering winds
from southerly to the northwest and increasing to around 10-15
kts, with gusts of 25-30 kts through 18z in western MN.

KMSP...Hi-res guidance continues to key in on a line of TSRA to
move through KMSP in the 21z to 02z timeframe with IFR vsbys
likely with any heavier storms. Cigs will reduce to MVFR levels
as the line passes through with IFR cigs likely at times
(70-90% chance) as the cold front works its way through
overnight. Winds will shift from southerly to northwesterly
overnight with winds in the 10-15 kt range. Cigs will remain
high-IFR to low-MVFR through Friday morning before slowly
improving by afternoon but likely remaining MVFR on Friday.

/OUTLOOK FOR KMSP/
FRI...MVFR/-SHRA possible, then VFR. Wind NW 10-15G20kts.
SAT...VFR. Wind NW 5-10 kts.
SUN...Chc MVFR/-SHRA. Wind E 5-10 kts.

&&

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

&&

$$

DISCUSSION...JRB
AVIATION...ARX