Alert archive / Wisconsin / Areal Flood Advisories in 2021

Areal Flood Advisory 36, NWS Green Bay, WI

August 29, 2021Outagamie County, Wisconsin

NWS Green Bay, WI issued this areal flood advisory at Aug 29, 2021, 12:08 AM CDT for Outagamie County, Wisconsin. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Aug 29, 2021, 12:08 AM CDT (05:08 UTC)
Expired
Aug 29, 2021, 2:51 AM CDT
In force
3 hr
Issued by
NWS Green Bay, WI
Area
Storm-based polygon

County Outagamie County, WI

The radar

The Green Bay radar (KGRB), 30 km from the middle of the area, began a volume at 05:09 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Green Bay/Straub, WI (KGRB), launched 00:00Z, 5.1 hours before the alert went out and 30 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Green Bay/Straub, WI at 00:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 969 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Green Bay/Straub, WI at 00:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 70 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
969 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
1292 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
70 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Green Bay, WI wrote its last area forecast discussion before this areal flood advisory went out at Aug 28, 6:37 PM CDT, 5 hours 31 minutes earlier.

Area forecast discussion, Aug 28, 6:37 PM CDT, 5 hours 31 minutes before
Area Forecast Discussion
National Weather Service Green Bay WI
637 PM CDT Sat Aug 28 2021

Updated aviation portion for 00Z TAF issuance

.SYNOPSIS...
Issued at 232 PM CDT Sat Aug 28 2021

Still warm and very humid with showers and thunderstorms
tonight--and possibly lingering over the east on Sunday. Cooler
and much less humid conditions are expected for the upcoming work
week.

Large scale pattern changes during the period will be rather
subtle. A modest band of seasonably strong westerlies will remain
across the northern United States and Canada throughout the
period. The mean trough position will be over the West, with
ridging downstream shifting between the eastern and central CONUS
and eastern Canada. Amplitude will tend to wane the first few days
of the period, increase a little during the upcoming work week,
then decrease again late in the period.

The warm and very humid air mass presently across the area will
give way to more seasonable (cooler and less humid) conditions,
with temperatures generally near to a little above normal after
tomorrow. The chance for precipitation will be limited after
tomorrow. So amounts for the period will depend heavily upon what
falls in about the next 30 hours, with below normal amounts
expected thereafter.
&&

.SHORT TERM...Tonight and Sunday
Issued at 232 PM CDT Sat Aug 28 2021

Skies were partly to mostly cloudy this afternoon. Scattered
showers and thunderstorms developed across portions of northeast
and east-central Wisconsin. The clouds, and showers and storms
have kept temperatures down with readings in the upper 70s to
middle 80s.

For the rest of the afternoon into tonight, scattered showers and
thunderstorms will continue to move northeast across northeast
Wisconsin. A cluster of showers and thunderstorms now across
northwest Wisconsin, which was warned on early this afternoon
will move into north-central Wisconsin late this afternoon mainly
north of Rhinelander at the moment based on radar trends. Will
need to monitor this cluster of storms that has a history of
producing gusty winds, frequent lightning strikes and torrential
rainfall.

Meanwhile, a cold front across the eastern Dakotas and northwest
Minnesota will be the focusing mechanism for additional shower and
thunderstorm develop. This cluster of storms will move into
central and north-central Wisconsin around or shortly after
midnight. Some of the storms could still be strong or severe, with
the main risk being damaging winds and torrential rainfall. The
models have the thunderstorms quickly weakening as they move into
northeast and east-central Wisconsin toward 12z Sunday. Lows
tonight will be in the lower to middle 60s north to the lower 70s
across northeast and east-central Wisconsin.

There will be some lingering showers around early Sunday morning
as the cold front enters the area. Yesterday, there was some
concern that there was a risk of severe weather across east-
central Wisconsin. It now appears the front will be just east of
the area where the risk of severe weather appears to be lower
today. The Storm Prediction Center Day 2 Outlook has removed the
marginal risk from east-central Wisconsin. The showers and storms
should come to an end by late afternoon with drier air filtering
in from the west.

.LONG TERM...Sunday Night Through Saturday
Issued at 232 PM CDT Sat Aug 28 2021

It now appears the cold front will exit the area quickly enough
that any convection accompanying the front will be east of the
area by 00Z Monday. Once the front clears the area, quiet weather
will settle over the region for a few days as an anticyclone
ridges from Hudson Bay into the Lake Superior region. Isolated-
scattered showers are possible mid-week as weak shortwaves rotate
through the area. Diurnal destabilization will probably play a
role in the rain chance, so any showers would most likely occur
during the middle to early evening.

Warmer air from the Plains will begin to return to the area late
in the period, leading to a little better chance for
precipitation late next week.

The standard broad-based blend of guidance products used to
initialize the forecast grids seemed reasonable, so no significant
changes were necessary.
&&

.AVIATION...for 00Z TAF Issuance
Issued at 637 PM CDT Sat Aug 28 2021

Another few rounds of showers and thunderstorms are expected
through Sunday morning ahead of a cold front approaching the
western Great Lakes region as evidenced on upstream doppler radar
observations. The best chance for this activity will be across
north-central Wisconsin as many CAMs models dissipate the storms
before they reach east-central Wisconsin. The showers and storms
could produce some gusty winds and heavy rain, but the highest
risk for severe weather appears to be out to the west. Look for
some MVFR/IFR CIGS to develop across northern Wisconsin late
tonight due to abundant low level moisture.

On Sunday, a cold front could trigger more storms across far
eastern Wisconsin early in the afternoon which could impact
KGRB/KATW/KMTW. At this time the coverage does not appear high
enough to include in the TAFs. Behind the cold front, gusts of 20
to 25 knots are expected from the west Sunday.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement from 5 AM CDT Sunday through Sunday
evening for WIZ022.
&&

SYNOPSIS.......Skowronski
SHORT TERM.....Eckberg
LONG TERM......Skowronski
AVIATION.......Kurimski
Hazardous weather outlook, Aug 28, 2:10 PM CDT, 9 hours 58 minutes before
Hazardous Weather Outlook
National Weather Service Green Bay WI
210 PM CDT Sat Aug 28 2021

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-291915-
Vilas-Oneida-Forest-Florence-Northern Marinette County-Lincoln-
Langlade-Menominee-Northern Oconto County-Door-Marathon-Shawano-
Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-Waushara-Winnebago-
Calumet-Manitowoc-Southern Marinette County-
Southern Oconto County-
210 PM CDT Sat Aug 28 2021

This Hazardous Weather Outlook is for north-central and northeast
Wisconsin.

.DAY ONE...Rest of the Afternoon and Tonight

Thunderstorms are possible through late tonight. Scattered strong
to severe thunderstorms are possible, especially over north-
central, central and far northeast Wisconsin. The main threats
would be damaging winds, heavy rainfall and hail. The greatest
risk for severe weather will be late this afternoon into early
Sunday morning.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

Thunderstorms are possible on Sunday. A few stronger storms are
possible across east-central Wisconsin from late morning through
mid afternoon on Sunday. Strong winds and hail will be the
possible with the stronger storms.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed through late tonight. Spotters
are requested to report rainfall reports over one inch, large hail
and damaging winds.

LMZ521-522-541>543-291915-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
210 PM CDT Sat Aug 28 2021

This Hazardous Weather Outlook is for portions of northwest Lake
Michigan and the waters of Green Bay.

.DAY ONE...Rest of the Afternoon and Tonight

Thunderstorms are possible through tonight. Any thunderstorms
will pose a hazard to mariners.

.DAYS TWO THROUGH SEVEN...Sunday through Saturday

Increasing southwesterly winds and building waves will cause
hazardous conditions for small craft on Sunday.

Thunderstorms are possible late Sunday morning and afternoon.
Some of the storms could contain hail and strong winds.

Eckberg/Skowronski

In the hours before

Special weather statement, Aug 28, 9:02 PM CDT, 3 hours 6 minutes before
Special Weather Statement
National Weather Service Green Bay WI
902 PM CDT Sat Aug 28 2021

WIZ049-050-290245-
Calumet WI-Manitowoc WI-
902 PM CDT Sat Aug 28 2021

...Strong thunderstorms will impact portions of southeastern Calumet
and southern Manitowoc Counties through 945 PM CDT...

At 902 PM CDT, trained weather spotters reported strong thunderstorms
along a line extending from near Camp Rokilio Scout Camp to near
Elkhart Lake. Movement was east at 20 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Trained weather spotters.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Strong thunderstorms will be near...
  St. Nazianz around 915 PM CDT.
  Valders and Camp Rokilio Scout Camp around 920 PM CDT.

Other locations in the path of these storms include Manitowoc and
Cleveland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with these storms and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4402 8809 4416 8749 4407 8759 4390 8769
      4389 8814
TIME...MOT...LOC 0202Z 258DEG 17KT 4397 8798 4387 8804

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

Kurimski
Local storm report, Aug 28, 9:04 PM CDT, 3 hours 4 minutes before
<!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>
Local storm report, Aug 28, 9:41 PM CDT, 2 hours 27 minutes before
<!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>
Local storm report, Aug 28, 10:34 PM CDT, 1 hour 34 minutes before
<!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>
Local storm report, Aug 28, 11:13 PM CDT, 55 minutes before
<!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>
Local storm report, Aug 28, 11:19 PM CDT, 49 minutes before
<!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>

The office that day

Everything else NWS Green Bay, WI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 28, 8:48 PM CDTSpecial Weather StatementGRBFlorence42 min
Aug 28, 9:02 PM CDTSpecial Weather StatementGRBManitowoc43 min
Aug 28, 10:06 PM CDTAreal Flood AdvisoryGRBCalumet, Manitowoc62 min
Aug 28, 10:24 PM CDTRiver Flood WarningGRBWood21 days
Aug 28, 10:38 PM CDTAreal Flood AdvisoryGRBPortage, Waupaca, Wood3 hr
Aug 28, 11:08 PM CDTFlash Flood WarningGRBCalumet, Manitowoc89 min
Aug 28, 11:22 PM CDTFlash Flood WarningGRBPortage, Waupaca3 hr
Aug 29, 1:15 AM CDTSpecial Marine WarningGRB34 min

Nearby

Areal Flood Advisories in Wisconsin, 2021Every areal flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.