Alert archive / Arizona / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 9, NWS Phoenix, AZ

July 7, 1999Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 7, 1999, 7:43 PM MST for Maricopa County, Arizona. It was in force for 62 min. 2 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 7, 1999, 7:43 PM MST (02:43 UTC)
Expired: Jul 7, 1999, 8:45 PM MST
In force: 62 min
Issued by: NWS Phoenix, AZ
Area: Whole counties

County Maricopa County, AZ

What was reported inside it

Time	Report	Where	Remark
Jul 7, 7:50 PM MST	Thunderstorm Wind 60	Phoenix, AZ	Widespread area of very strong winds, damaged homes and cut power to at least 11,500 customers around the metropolitan area. Trees and limbs were downed. Official winds to 57 mph were clocked at 43rd Ave and lower Buckeye Road. President Clinton, arrived in Ph
Jul 7, 8:30 PM MST	Thunderstorm Wind 60	Scottsdale, AZ	An entire line of power poles down along McDowell Road between Longmore and Dobson roads.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 2.7 hours before the alert went out and 198 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: 4 J/kg
Mixed-layer CIN: -322 J/kg
Mixed-layer LCL: 1577 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 51 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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.

In the hours before

Special weather statement, Jul 7, 6:10 PM MST, 1 hour 33 minutes before

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Special weather statement, Jul 7, 6:10 PM MST, 1 hour 33 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.
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    </section>
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</body>
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The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 7, 5:59 PM MST	Severe Thunderstorm Warning	PSR	Pinal	51 min
Jul 7, 7:50 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	35 min
Jul 7, 8:28 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	32 min
Jul 8, 4:00 PM MST	Severe Thunderstorm Warning	PSR	Gila	45 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1999 Every severe thunderstorm warning in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.