Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 18, NWS Miami, FL

April 27, 1999Palm Beach County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Apr 27, 1999, 2:43 PM EDT for Palm Beach County, Florida. It was in force for 47 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: Apr 27, 1999, 2:43 PM EDT (18:43 UTC)
Expired: Apr 27, 1999, 3:30 PM EDT
In force: 47 min
Issued by: NWS Miami, FL
Area: Whole counties

County Palm Beach County, FL

The radar

The Miami radar (KAMX), 115 km from the middle of the area, began a volume at 18:44 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

Tampa Bay, FL (KTBW), launched 12:00Z, 6.7 hours before the alert went out and 227 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: 684 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 913 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

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, Apr 27, 10:05 AM EDT, 4 hours 38 minutes before

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Special weather statement, Apr 27, 2:01 PM EDT, 42 minutes before

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Special weather statement, Apr 27, 2:01 PM EDT, 42 minutes before

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<head>
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      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
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The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 27, 2:37 PM EDT	Severe Thunderstorm Warning	MFL	Broward	48 min
Apr 27, 3:12 PM EDT	Severe Thunderstorm Warning	MFL	Miami-Dade	48 min

Nearby

Severe Thunderstorm Warnings in Florida, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.