Special Weather Statement, NWS Twin Cities, MN

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
656 AM CDT Tue Oct 24 2023

.DISCUSSION...(Today through Monday)
Issued at 331 AM CDT Tue Oct 24 2023

KEY MESSAGES:

- Multiple rounds of showers and storms expected through tonight for
  southern and eastern MN into western WI. A small risk for
  marginally severe hail will continue through tonight.

- Widespread rain remains likely Thursday/Thursday night with areas
  in southeastern MN into western WI seeing the most precip.

- Cold air to sweep in behind the late week system with max temps in the
  upper 30s this weekend. First flakes of the season are possible
  with these seasonably cold temps.

As expected, storms fired on the northern edge of the LLJ where
strong isentropic ascent and nearly 2000 j/kg of MUCAPE were present.
A few stronger cells developed, though we were able to scare up
nothing more than some penny size hail reports. As we go through the
morning, storm coverage will diminish as the h85 winds veer some and
becoming nearly parallel to the isotherms, shutting down the
overrunning process we saw overnight. We will get a short lull in
precip this morning as we transition from more isentropic forcing to
fgen related forcing. This transition doesn't look to take very long
and by the early afternoon, showers and storms should get going again
as fgen within the baroclinic zone gets going. This baroclinic zone
and associated fgen will only crawl slightly to the east through
tonight, with multiple rounds of showers and storms expected from
roughly Redwood Falls to St. Cloud on east. Some of the areas that
have seen a good amount of rain overnight will see a few more rounds
of rain through tonight, with a couple of streaks of 2+ inches of
rain through tonight likely, especially in the region from Mankato
over to Eau Claire. This heavy rain threat is highlighted by the 24
hour LPMM QPF ending 12z Wednesday from the HREF, which shows a
couple of streaks of 5-7" of rain for today/tonight over in WI.

As for the severe threat, HREF updraft strength and helicity tracks
continue to show this first overnight round of convection producing
the strongest updrafts through tonight. For later today, the location
of the warm front will determine where we have potential for some
surface based convection. That warm front looks to just sneak to the
west and north of Albert Lea and continue northeast to around Eau
Claire. Much of the convection we see develop within the h85
baroclinic zone this afternoon and tonight looks to happen on the
cool side of this boundary, but enough elevated instability and
shear will be in place to continue to support a marginal risk for
near severe hail. Any wind risk will happen closer to the warm
front, so for us, that risk would reside from roughly Albert Lea to
Eau Claire. Again, the bigger risk today/tonight looks to be from
excessive rain, as multiple rounds of showers and storms are
expected, with that Mankato to Eau Claire region looking to be most
susceptible to excessive rain issues given where storms Monday night
tracked.

Eventually we will get a break on Wednesday as the low level flow
becomes divergent as a surface ridge axis builds in. Though dry, it
will be a cloudy Wednesday, with temperatures not expected to move
very much during the day. This break in precip will be short-lived
though as the next surge in moisture will be moving into southern MN
Wednesday evening.

Come Thursday, there is high confidence in a shortwave advancing
from the South Central Plains toward the Great Lake region. This will
bring another round of precipitation to the region, with the QPF
winners again being in the SE quadrant of MN into western WI. Per the
EPS, forecast PWAT values in the aforementioned region exceed
climatological normals for late October by 250-300% on Thursday. The
flooding potential will certainly be something to keep an eye on as
soils will be saturated from systems earlier in the week. However, a
dry Wednesday will help to mitigate most concerns. Thursday's system
will be more widespread than earlier in the week, with thunder
chances limited to SE MN and western WI. Temperatures in the 50s lead
to high confidence in P-Type not being an issue, yet. It is looking
increasingly likely that areas SE of a line from Mankato-
Minneapolis-Rice Lake will see 1-3" rain through Friday morning (with
highest amounts farther to the SE). The GFS/EPS/CMC agree in near
1.5" at MSP through Thursday night. Taking a look in EAU, the same
trio of models is forecasting 2-2.5".

PoPs will settle on Friday, but the winds won't. The pressure field
will strengthen ahead of a synoptic scale positively-tilted trough
that will arrive late in the weekend. Sustained NW winds around
20MPH, gusting to 30MPH, are likely on Friday afternoon. This will
contribute to quite the gradient in high temps on Friday. Western WI
will be able to reach the 50s, where western MN will struggle to
reach the 40s. By Saturday, the chilly high temps in the 30s will
plague all. Scattered 30% PoPs on Saturday means some could see the
first flakes of the season in the afternoon. No accumulation is
expected as large positively-tilted troughs tend not to be big
producers on the QPF side of things.

With a large upper-level trough spanning the CONUS through the end
of the month, cooler than normal temperatures are favored. They will
stick around at least through the end of the month into early
November, as can be seen highlighted in the CPC's 8-14 day outlook.

&&

.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
Issued at 645 AM CDT Tue Oct 24 2023

We're in a lull of precip right now as we transition from the
overrunning precip we saw overnight to more frontally forced precip
for later today. That round is already starting to develop in SoDak
and should expand rapidly in western MN between 14z and 16z. Once it
gets going, we'll see several rounds of showers and thunderstorms
this afternoon through tonight from RWF to STC on east. Low cigs have
been slow to develop this morning, so did delay their arrival some,
but as rain expands this morning, MVFR cigs should start to develop
with it, with IFR cigs likely overnight as we get on the cold side of
the main frontal boundary.

KMSP...Expect the next round of showers and storms to move in around
lunch time and once it gets here, there will be on and off showers
and storms through about 6z tonight. Cigs have been slow to drop, but
once the next round of precip arrives, the atmo looks to finally
moisten enough to where it will be hard to avoid MVFR/IFR cigs for
the rest of the period.

/OUTLOOK FOR KMSP/
Wed...MVFR/VFR. -SHRA/IFR overnight. Wind NE 5-10 kts.
Thu...MVFR chc IFR. -SHRA likely. Wind NE 10-15 kts.
Fri...VFR. Chc -SHRA/IFR in the morning. Wind NW 15G25 kts.

&&

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

DISCUSSION...MPG/PEM
AVIATION...MPG

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
834 AM CDT Tue Oct 24 2023

WIZ028-241400-
Eau Claire WI-
834 AM CDT Tue Oct 24 2023

...A STRONG THUNDERSTORM WILL IMPACT SOUTHEASTERN EAU CLAIRE COUNTY
THROUGH 900 AM CDT...

At 834 AM CDT, Doppler radar was tracking a strong thunderstorm over
Price, or 17 miles northeast of Whitehall, moving east at 45 mph.

HAZARD...Penny size hail.

SOURCE...Radar indicated.

IMPACT...Minor hail damage to vegetation is possible.

Locations impacted include...
Fairchild.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4460 9124 4467 9092 4460 9092
TIME...MOT...LOC 1334Z 253DEG 39KT 4457 9110

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...<30 MPH

CTG