Alert archive / Florida / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 20, NWS Jacksonville, FL

April 23, 1997Clay County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Apr 23, 1997, 7:29 AM EDT for Clay County, Florida. It was in force for 31 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: Apr 23, 1997, 7:29 AM EDT (11:29 UTC)
Expired: Apr 23, 1997, 8:00 AM EDT
In force: 31 min
Issued by: NWS Jacksonville, FL
Area: Whole counties

County Clay County, FL

What was reported inside it

Time	Report	Where	Remark
Apr 23, 7:29 AM EDT	Hail 1	Orange Park, FL
Apr 23, 7:57 AM EDT	Thunderstorm Wind	Lake Geneva, FL	Large trees were blown down.

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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 23, 3:00 AM EDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Jacksonville, FL (KJAX), launched 00:00Z, 11.5 hours before the alert went out and 59 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: 814 J/kg
Mixed-layer CIN: -147 J/kg
Mixed-layer LCL: 1303 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

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.

NWS Jacksonville, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 23, 2:10 AM EDT, 5 hours 19 minutes earlier.

Area forecast discussion, Apr 23, 2:10 AM EDT, 5 hours 19 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
210 AM EDT WED APR 23 1997

LTST SFC ANAL SHOWS LOW ACROSS N GA WITH SECONDARY LOW ACROSS SOUTHERN AL
WITH FNT XTNDG ACROSS N GA...CNTRL AL...AND SE MS. SAT LOOPS SHOW
SUBTROPICAL JET ACROSS GULF WITH POLAR JET DIGGING INTO SE. ACCOMPANYING
THESE WE HAVE TWO JET STREAKS COMBINING WITH INCREASED DIFF VORT AVECTION
ACROSS ATMOSPHERIC COLUMN...AND DRY AIR INTRUSION AT MID LVLS...TO CREATE
THREAT OF SVR WX. ETA SEEMS TO HAVE A GUD HNDL OF SITUATION SO WILL STICK
WITH IT. AT THIS TIME IT SEEMS TO ME THAT MAIN THREAT OF SVR WX WILL CONT
FOR GA THRU THE LATE MORNING HOURS WITH THREAT OF SVR WX MOVG INTO FL AFTER
SUNRISE. LOOKING AT HELICITY VALUES IN NAWIPS AND SNDGS ACROSS THE AREA
FROM 00Z I BELIEVE THAT MAIN THREAT WITH STORMS WILL BE LARGE HAIL...
DUE TO DRY AIR INTRUSION ALOFT WITH WET BULBS RANGING BETWEEN 9000/10000...
ACROSS BOTH SE GA AND FL WITH THREAT OF TORNADIC ACTIVITY GREATEST NORTH
OF CWA.

SSI TU 081/054 075/055 18600
JAX TU 082/053 076/051 18700
GNV TU 082/052 077/050 18700

SANTOS

In the hours before

Special weather statement, Apr 23, 6:48 AM EDT, 41 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, Apr 23, 7:04 AM EDT, 25 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, Apr 23, 7:07 AM EDT, 22 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, Apr 23, 7:18 AM EDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FLORIDA
718 AM EDT WED APR 23 1997

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0510 AM    CALLAHAN                  FL   TORNADO
04/23/97   NASSAU                         PRELIMINARY REPORT...POWER
                                          OUT WITH TREES DOWN.

0515 AM                              FL   TORNADO
04/23/97   NASSAU                         TORNADO TOUCHDOWN AT
                                          INTERSTATE 95 AND STATE
                                          ROAD A1A.

0535 AM    ARLINGTON                 FL   WIND DAMAGE
04/23/97   DUVAL                          LARGE TREE DOWN ACROSS
                                          HOUSE ON PINCANNON ROAD

0540 AM    JACKSONVILLE              FL   WIND DAMAGE
04/23/97   DUVAL                          TREES DOWN ACROSS
                                          PICKETVILLE ROAD

0545 AM    JACKSONVILLE              FL   WIND DAMAGE
04/23/97   DUVAL                          TREES AND POWER LINES DOWN
                                          ON GARDEN STREET

Local storm report, Apr 23, 7:18 AM EDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE JACKSONVILLE FLORIDA
718 AM EDT WED APR 23 1997

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0510 AM    CALLAHAN                  FL   TORNADO
04/23/97   NASSAU                         PRELIMINARY REPORT...POWER
                                          OUT WITH TREES DOWN.

0515 AM                              FL   TORNADO
04/23/97   NASSAU                         TORNADO TOUCHDOWN AT
                                          INTERSTATE 95 AND STATE
                                          ROAD A1A.

0535 AM    ARLINGTON                 FL   WIND DAMAGE
04/23/97   DUVAL                          LARGE TREE DOWN ACROSS
                                          HOUSE ON FINCANNON ROAD
0540 AM    JACKSONVILLE              FL   WIND DAMAGE
04/23/97   DUVAL                          TREES DOWN ACROSS
                                          PICKETVILLE ROAD

0545 AM    JACKSONVILLE              FL   WIND DAMAGE
04/23/97   DUVAL                          TREES AND POWER LINES DOWN
                                          ON GARDEN STREET

Local storm report, Apr 23, 7:20 AM EDT, 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSONVILLE FLORIDA
718 AM EDT WED APR 23 1997

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0510 AM    CALLAHAN                  FL   TORNADO
04/23/97   NASSAU                         PRELIMINARY REPORT...POWER
                                          OUT WITH TREES DOWN.

0515 AM                              FL   TORNADO
04/23/97   NASSAU                         TORNADO TOUCHDOWN AT
                                          INTERSTATE 95 AND STATE
                                          ROAD A1A.

0535 AM    ARLINGTON                 FL   WIND DAMAGE
04/23/97   DUVAL                          LARGE TREE DOWN ACROSS
                                          HOUSE ON PINCANNON ROAD

0540 AM    JACKSONVILLE              FL   WIND DAMAGE
04/23/97   DUVAL                          TREES DOWN ACROSS
                                          PICKETVILLE ROAD

0545 AM    JACKSONVILLE              FL   WIND DAMAGE
04/23/97   DUVAL                          TREES AND POWER LINES DOWN
                                          ON GARDEN STREET

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 23, 4:59 AM EDT	Tornado Warning	JAX	Nassau	31 min
Apr 23, 5:29 AM EDT	Severe Thunderstorm Warning	JAX	Duval	61 min
Apr 23, 7:38 AM EDT	Severe Thunderstorm Warning	JAX	Columbia, Suwannee	37 min
Apr 23, 7:46 AM EDT	Severe Thunderstorm Warning	JAX	Saint Johns	44 min
Apr 23, 7:57 AM EDT	Tornado Warning	JAX	Clay, Putnam	33 min
Apr 23, 8:13 AM EDT	Tornado Warning	JAX	Alachua	47 min
Apr 23, 8:31 AM EDT	Tornado Warning	JAX	Bradford, Clay	59 min
Apr 23, 8:43 AM EDT	Flash Flood Warning	JAX	Alachua	4 hr
Apr 23, 9:41 AM EDT	Severe Thunderstorm Warning	JAX	Flagler	49 min
Apr 23, 9:56 AM EDT	Tornado Warning	JAX	Marion	64 min
Apr 23, 10:08 AM EDT	Flash Flood Warning	JAX	Putnam	4 hr
Apr 23, 10:31 AM EDT	Severe Thunderstorm Warning	JAX	Flagler	29 min
Apr 23, 11:39 AM EDT	Severe Thunderstorm Warning	JAX	Alachua	36 min
Apr 23, 11:50 AM EDT	Severe Thunderstorm Warning	JAX	Clay	40 min
Apr 23, 12:26 AM EDT	Severe Thunderstorm Warning	JAX	Coffee, Jeff Davis	49 min
Apr 23, 3:20 AM EDT	Severe Thunderstorm Warning	JAX	Ware	40 min
Apr 23, 3:39 AM EDT	Severe Thunderstorm Warning	JAX	Wayne	51 min

Nearby

Severe Thunderstorm Warnings in Florida, 1997 Every severe thunderstorm warning in 1997

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.