Special Weather Statement, NWS Green Bay, WI

Area Forecast Discussion
National Weather Service Green Bay WI
626 PM CDT Sun Jul 16 2023

Updated aviation portion for 00Z TAF issuance

.UPDATE...
Issued at 313 PM CDT Sun Jul 16 2023

Continuing to monitor some high-based and low-topped convection
ahead of a cold front entering the northwest portion of the
forecast area. Showers and storms have been gradually increasing
in areal coverage since 2 pm CDT north of highway 29. Proximity
soundings (RAP) are strongly inverted-V with steep 0-3 km LRs
thus certainly some wind gust potential with any storms that can
maintain a decent updraft and dump some water into the dry
boundary layer for additional evaporative cooling. Will continue
to handle with SPSs for now with potential for a few localized
wind gusts to 50 mph. Storms will gradually move southeast across
the remainder of the forecast area and should gradually weaken
after 00Z.
&&

.SHORT TERM...Tonight and Monday
Issued at 155 PM CDT Sun Jul 16 2023

The main concerns for the short term forecast will be:
-Rain and a few storms this afternoon and evening
-Lingering smoke aloft from the Canadian wildfires
-Another small showers chance tomorrow

Storms Today:
A weak cold front will work its way across the region this
afternoon and evening, bringing showers with a chance of thunder
to the region. The main front is still in northwestern WI, but
some of the showers and a few storms will work their way into
north-central WI by the mid afternoon. Dynamics along the front
will be the main driver for any thunderstorm development, with
fairly impressive bulk shear around 35 knots and strong vorticity
advection along the left exit region of an upper level jet.
Despite the forcing however, instability remains at a premium,
with more modest CAPE values around 500 to 700 J/kg and only
modest mid-level lapse rates. As a result, storms will likely be
fairly scattered with the frontal passage. Stronger storms will
likely be relatively brief, arising only where the strongest
forcing aligns with the better instability. The main thunderstorm
concerns will be wind gusts mixing to the surface and small hail.
Severe weather still seems unlikely at this time.

Smoke:
Smoke has rapidly improved over the course of the day, with
surface visibility from smoke around 3 miles this morning lifting
to relatively unlimited visibility at the surface. Some hazy skies
and light smoke at the surface will remain through at least
midnight however, especially across central to east-central
Wisconsin, including the Fox Valley. There area a few hints that
some haze will return Monday afternoon, but for the most part the
worst of the smoke will be out of the region for now.

Showers Monday:
Another weak shortwave will work its away across the north on
Monday, producing cloudy skies along the Upper Peninsula border.
Some light precipitation will be possible out of this layer at
times, but no thunder is currently expected. The rest of the area
will predominantly see dry conditions.

Aside from the concerns above, temperatures will be a few degrees
cooler than last night, with lows in the upper 40s to middle 50s.
Tomorrow, high temperatures are forecast to be in the upper 60s to
upper 70s.

.LONG TERM...Monday Night Through Sunday
Issued at 155 PM CDT Sun Jul 16 2023

Overall, no significant changes to the long term portion of this
forecast package.

As far as the big picture is concerned, large-scale upper-level
pattern will undergo a rapid transition as the upper-level low
that has been loitering around southern Hudson Bay finally
releases to the northeast by 12Z Tuesday allowing upper-level
heights to rebound over the western Great Lake with flow becoming
strongly zonal. Unfortunately, consensus of medium range guidance
is also locking in on another pesky upper-level circulation over
southern Canada that will slowly drift southeast and becoming
situated somewhere just north of Lake Superior by 12Z Thursday.
With the fast zonal flow in place, confidence remains low during
the mid-week in terms of timing of aforementioned upper-low and
any weaker impulses that may eject from this primary system into
the forecast area.

In response to the approaching upper-level system, broad upper-
level PVA in concert with low-level WAA will increase late
Wednesday over the northwest portion of the forecast area, in
concert with an approaching cold front. At least initially, deeper
boundary layer moisture, steep mid-level LRs and best overall
instability will be somewhat limited as these will be mostly
bottled up across the central plains near a strong W-E baroclinic
zone that will be host to MCS activity there. Thus, it appears
precipitation late Wednesday into Wednesday night will be on the
lighter side and mostly confined to the Northwest half of the
forecast area.

On Thursday, the upper-level low pressure system and associated
surface low pressure system and cold front will likely be located
somewhere over Wisconsin with additional shower and thunderstorm
activity probable. Whether or not any of the convective activity
is able approach severe limits later in the day will largely
depend on cloud cover, extent of lingering morning activity and
how progressive the surface cold front will translate across the
forecast area. Regardless, the period from roughly 06Z Thursday
through 00Z Friday will be rather unsettled. Given the above
uncertainty, stayed close to blended temperature guidance during
this period.

Model consensus for Friday suggests that although surface low
pressure will be east of the forecast area, some E-W orientated surface
troughing may persist suggesting perhaps some diurnal shower
activity, especially into the afternoon.

By early next weekend, it appears we will be back into a more NW
flow regime with some potential for some weaker, moisture limited
impulses dropping southeast across the area from time to time.
&&

.AVIATION...for 00Z TAF Issuance
Issued at 618 PM CDT Sun Jul 16 2023

A cold front and upper level disturbance will produce scattered
showers and thunderstorms through about 03z, so will have TEMPO
groups in the TAFs. Patchy smoke/haze in the southern part of the
forecast area is also expected to improve this evening. Expect
clearing skies and diminishing winds overnight. On Monday, expect
a fairly quiet day with gusty WNW winds and widespread cumulus
developing by mid to late morning. Ceilings could initially be in
the MVFR category in northern WI, but should rise to VFR by early
afternoon. A few light showers or sprinkles may also occur in far
northern WI.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&

UPDATE.........ESB
SHORT TERM.....Uhlmann
LONG TERM......ESB
AVIATION.......Kieckbusch

Hazardous Weather Outlook
National Weather Service Green Bay WI
215 PM CDT Sun Jul 16 2023

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-171915-
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-
215 PM CDT Sun Jul 16 2023

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

.DAY ONE...Tonight

Scattered thunderstorms are possible late this afternoon, especially
north of Highway 29. The strongest storms could produce gusty
winds to 45 mph and small hail. The storms will gradually weaken
as they move southeast across the remainder of the forecast area
this evening.

Wildfire smoke from Canada may lead to reduced air quality at
times primarily south of Highway 29. An Air Quality Advisory is
in effect for east central Wisconsin and areas south until
midnight.

.DAYS TWO THROUGH SEVEN...Monday through Sunday

Thunderstorms are possible late Wednesday through Thursday. It's
too early to determine whether any of the storms will approach
severe limits.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely not be needed today and tonight.

LMZ521-522-541>543-171915-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
215 PM CDT Sun Jul 16 2023

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

.DAY ONE...Tonight

Scattered thunderstorms are possible this afternoon and evening.
Any thunderstorms could pose a hazard to mariners.

.DAYS TWO THROUGH SEVEN...Monday through Sunday

Thunderstorms are possible Wednesday through Thursday. Any
thunderstorms could pose a hazard to mariners.

<!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>

<!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>

<!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>

<!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>

<!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>

<!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>