Alert archive / California / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 7, NWS Sacramento, CA

May 24, 2019Butte County, Sierra County, Yuba County, California

NWS Sacramento, CA issued this severe thunderstorm warning at May 24, 2019, 10:29 PM PDT for Butte County, Sierra County, Yuba County, California. It was in force for 40 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: May 24, 2019, 10:29 PM PDT (05:29 UTC)
Expired: May 24, 2019, 11:09 PM PDT
In force: 40 min
Issued by: NWS Sacramento, CA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Butte County, CA, Sierra County, CA, Yuba County, CA

The radar

The Beale AFB radar (KBBX), 41 km from the middle of the area, began a volume at 05:32 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 5.5 hours before the alert went out and 347 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 178 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 2118 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 167 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

What forecasters said that day

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

NWS Sacramento, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at May 24, 1:54 PM PDT, 8 hours 35 minutes earlier.

Area forecast discussion, May 24, 1:54 PM PDT, 8 hours 35 minutes before

Area Forecast Discussion
National Weather Service Sacramento CA
154 PM PDT Fri May 24 2019

.SYNOPSIS...
Scattered rain showers and thunderstorms mainly mountains and
foothills today and Saturday as one low pressure system moves
east and another drops in to take its place. Locally heavy rain
possible. More widespread showers or thunderstorms on Sunday and
Sunday night with snow for the higher Sierra elevations.
Afternoon mountain showers continuing through mid week. &&

.DISCUSSION...
Showers and a few isolated thunderstorms have popped up over the
Sierra early this afternoon, thanks to a upper level disturbance
moving through the area. Favorable conditions for shower and
tstorm activity will likely continue into the early evening hours,
with most of the precip staying confined to the terrain. However,
some shower activity may slip into the Sacramento valley this
evening as the upper low drops farther southward. Overall
precipitation amounts are expected to remain light but some
embedded heavier showers/thunderstorms could bring locally heavier
precipitation.

Looking to Saturday a Pacific Northwest trough will drop
southward through Northern California and will mostly be an
inside slider type of system. Therefore, the biggest chance of
showers or thunderstorms will be over the eastern half of the
forecast area. Once again precip amounts overall will be light
but heavier showers will be possible. The passage of the trough
will also bring cooler air into the north state, putting our high
temperatures to a few to several degrees below normal.

Come Sunday, a stronger low pressure system is forecast to arrive
in northern California. Showers and thunderstorms will remain in
the forecast but over the entire CWA this time. This system will
usher in even cooler air which will drop snow levels and put our
daytime highs down to 10-15 degrees below normal. Snow levels will
likely drop to below pass levels, which will likely bring travel
impacts to the Sierra. The greatest threat for snowfall and
potential accumulation will be Sunday - Monday morning, so
travelers should take note of the road conditions and forecast
before heading out. This storm system will shift eastward into
the Great Basin on Monday, placing the shower threat on our
eastern mountains. By the afternoon, snow levels should be above
pass levels with daytime highs climbing a bit although remaining
below normal.

&&

.EXTENDED DISCUSSION (Tuesday THROUGH Friday)

Unsettled pattern continues through the period as ensembles
support troughing across the area through the week. Chances for
showers or thunderstorms expected over higher terrain throughout
the week, mainly in the afternoon and early evening hours.
Elsewhere, dry conditions are expected. Temperatures will be on
the rise through the period with Valley highs in the upper 70s to
low 80s Tuesday, reaching into the mid and upper 80s by late next
week.

&&

.AVIATION...

Mainly VFR conditions at TAF sites next 24 hours. Local MVFR/IFR
conditions in showers and thunderstorms mainly over the
foothills/mountains and the N Sac Valley through the overnite hrs
obscuring higher terrain Sustained winds less than 15 kts at TAF
sites with local gusts to 20 kts. After sunrise Sat morning,
marine cloudiness spreading inland into the Srn Sac Vly with MVFR
CIGS 015-025 expected.

&&

.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&

In the hours before

Local storm report, May 24, 8:31 PM PDT, 1 hour 58 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>

Special weather statement, May 24, 9:14 PM PDT, 1 hour 15 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, May 24, 9:34 PM PDT, 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, May 24, 10:23 PM PDT, 6 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, May 24, 10:26 PM PDT, 3 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, May 24, 10:26 PM PDT, 3 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 Sacramento, CA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 24, 5:17 PM PDT	Special Weather Statement	STO	Lake	58 min
May 24, 6:03 PM PDT	Special Weather Statement	STO	Shasta	57 min
May 24, 6:39 PM PDT	Special Weather Statement	STO	Shasta	66 min
May 24, 6:46 PM PDT	Severe Thunderstorm Warning	STO	Shasta	44 min
May 24, 7:28 PM PDT	Special Weather Statement	STO	Shasta	47 min
May 24, 7:45 PM PDT	Severe Thunderstorm Warning	STO	Shasta	45 min
May 24, 8:05 PM PDT	Special Weather Statement	STO	Glenn	40 min
May 24, 8:16 PM PDT	Tornado Warning	STO	Shasta	44 min
May 24, 9:14 PM PDT	Special Weather Statement	STO	Shasta	46 min
May 24, 9:43 PM PDT	Severe Thunderstorm Warning	STO	Butte, Plumas	47 min
May 24, 9:50 PM PDT	Flash Flood Warning	STO	Butte	115 min
May 25, 1:51 AM PDT	Special Weather Statement	STO	Tehama	39 min
May 25, 2:45 AM PDT	Severe Thunderstorm Warning	STO	Tehama	45 min
May 25, 3:35 AM PDT	Special Weather Statement	STO	Butte	25 min
May 25, 10:55 AM PDT	Winter Weather Advisory	STO		33 hr

Nearby

Severe Thunderstorm Warnings in California, 2019 Every severe thunderstorm warning in 2019

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.