Eau Claire, Wisconsin 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

187
FXUS63 KMPX 180423
AFDMPX

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1123 PM CDT Thu Apr 17 2025

.KEY MESSAGES...

- Strong to severe thunderstorms remain possible this afternoon
  through this evening. Large hail will be the primary threat
  with localized heavy rain possible, especially across the
  Minneapolis/St. Paul metro area. Damaging wind or a couple
  tornadoes cannot be ruled out.

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

&&

.DISCUSSION...
Issued at 230 PM CDT Thu Apr 17 2025

Today - Tonight: Severe Storms Possible

As of 12:30 this afternoon, a line of strong storms formed generally
along the Mississippi River from Wabasha to Rush City, MN. These
formed along an axis of instability and locally increased shear.
The storms have remained elevated in nature and have produced
some sub-severe hail ranging from pea to nickel sized. These are
moving off to the northeast fairly quickly and have now exited
the local area.

Moving into the convection for this afternoon, an upper level
shortwave is currently rippling from southwest to northeast across
the north/central plains and into Southern Minnesota. Warm air
advection associated with a 850 mb low level jet is transporting
warm/moist air from the southern plains into southern Minnesota with
dew points across southwestern and south/central Minnesota already
in the mid 50s. This is pushing SBCAPE values over 1000 J/kg west of
I-35. With clearing skies across this area, SBCAPE values could
climb to around 2000 J/kg in the next hour or 2. This area is
located in an inverted trough with a surface low forming across the
Northern Plains and a warm front lifting northeast, creating a warm
sector. Convective initiation is expected between 19-21Z in this
warm sector as synoptic lift increases ahead of the surface low and
frontal boundaries. Storms that form ahead of the warm front will
remain elevated in nature but storms in the warm sector should be
able to tap into the plentiful SBCAPE and mid level lapse rates in
the 7.5-9 deg C/km. Shear will not be as impressive this far north
with EBWD in the 20-30 kt range. Forecast hodographs show modest
veering in the lowest 3km with long/straight continuations above 3
km. Taking the shear into account, it looks like discrete storms
will grow upscale into a more linear feature with embedded
supercells. The main threat with the steep mid level lapse rates and
instability looks to be large hail but deep inverted-V forecast
soundings across the local area highlights a potentially increased
damaging wind threat. This also drops the chances for a tornado to
near zero with the high LCLs in the inverted V.

Along with the severe weather threats, we will also see a threat for
heavy rainfall and potential flash flooding across the MSP metro
area this evening. Soundings show deep precipitable water values in
the 1-1.25 inch range which could break the daily max according to
SPC sounding climatology with an April 18 00Z max of 1.16 in. With
the influx of moisture and increased synoptic lift across the area,
a robust area of showers and thunderstorms will develop this
afternoon. Should any of these storms begin to train across the same
area, they could bring localized heavy rainfall. Once the activity
organizes into a more linear segment, the storms should move fairly
quickly off to the east. The 17.12 HREF highlights some low
probabilities of rain rates exceeding 1 inch per hour across the MSP
metro area and east/central Minnesota this afternoon and evening.
Given how dry the area has been recently, flash flooding would be
limited to the metro areas with increased runoff. WPC has
highlighted the MSP metro area in their Day 1 Excessive Rainfall
Outlook with a marginal. The threat for flooding is low overall but
not impossible given the abundant moisture present.

Friday - Mid Next Week: Rain Chances and Warming Temperatures

Some lingering rain showers will continue through tomorrow but the
heaviest rain should come with the activity this afternoon/evening
as any location will likely not see much more than a tenth of
additional accumulation. An upper level trough axis should swing
through late Friday into early Saturday and wipe out rain chances
across the area. Temperatures will be coolest tomorrow with the rain
chances and north/northwesterly surface flow keeping high
temperatures in the upper 40s to mid 50s. With continued weak CAA
into Saturday, high temperatures will stay limited to the 50s.

An upper low across the Texas Panhandle early Sunday is expected to
eject northeast into the Upper Midwest through the day. Ahead of
this, an inverted surface trough is expected to develop across the
Dakotas with warmer temperatures in the 60s just to our west. Right
now, we are forecast to stay mainly in the 50s, apart from far
western portions of our area in Lac qui Parle and Yellow Medicine
counties which could climb into the lower 60s. As the low begins to
move into the upper Midwest, we currently look to stay on the
western side of it. The EC ensemble tends to track the low closer to
our area with higher rain totals possible compared to the GFS
ensemble with lower totals and a more easterly track. Blended
guidance has come more in line with the EC with the track further
west and increased PoPs east of I-35 Sunday into Monday. Another
weak shortwave trough Tuesday will keep rain chances in the forecast
with a chance for thunderstorms with some instability forecast.
Overall impacts should be minimal overall.

Temperatures Monday will stay cooler to the east with the increased
rain chances and with 60s west of the I-35 corridor. Temperatures
across the area increase into the upper 50s to 60s areawide Tuesday
through the end of the week with 850 mb thermal ridging building
into the area with 850 mb temps 6-10 degrees above normal for late
April.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1102 PM CDT Thu Apr 17 2025

The precipitation shield continues to shrink this evening and
have been able to remove TS mention for all TAF sites this
cycle. Light rain is still likely at the start for EAU but the
other TAF sites will start out dry. The only chance for
precipitation looks to potentially be a few showers in far
eastern MN into western WI mid-to-late Friday afternoon.
Otherwise, MVFR ceilings are expected for all sites prior to
sunrise, remaining as such for much of Friday. There is a decent
potential for IFR ceilings at the WI TAF sites tomorrow, so have
added such mention to those sites. Winds will eventually swing
around from S to NW with the passage of a cold front this
evening, with speeds remaining near 10kts overnight then
increasing to near 15G25kts during the day tomorrow.

KMSP...No additional precipitation expected for tonight so have
initialized with a dry TAF and with clouds within VFR range.
However, MVFR ceilings are expected prior to sunrise, which are
then expected to remain in place for much of the day. A few
showers mid-to-late day are possible, but not expected to be
significant in and of themselves as the ceilings will be the
main issue to deal with.

/OUTLOOK FOR KMSP/
SAT...VFR. Wind NW 5-10 kts.
SUN...VFR early. MVFR/-SHRA likely late. Wind SE 10-15 kts.
MON...Chance MVFR/-SHRA early. VFR late. Wind N 10 kts.

&&

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

&&

$$

DISCUSSION...Barendse/ARX
AVIATION...JPC