Alert archive / Florida / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 131, NWS Jacksonville, FL

June 20, 2001Alachua County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Jun 20, 2001, 7:38 PM EDT for Alachua County, Florida. It was in force for 37 min. 1 report 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
Jun 20, 2001, 7:38 PM EDT (23:38 UTC)
Expired
Jun 20, 2001, 8:15 PM EDT
In force
37 min
Issued by
NWS Jacksonville, FL
Area
Whole counties

County Alachua County, FL

The radar

The Jacksonville radar (KJAX), 110 km from the middle of the area, began a volume at 23:39 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.

What was reported inside it

TimeReportWhereRemark
Jun 20, 8:00 PM EDTThunderstorm WindGainesville, FLNumerous reports of large trees and power lines 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 nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 11.6 hours before the alert went out and 219 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-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2001-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 636 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 12:00Z on 2001-06-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
636 J/kg
Mixed-layer CIN
-55 J/kg
Mixed-layer LCL
1062 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
10 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.

NWS Jacksonville, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 20, 2:30 PM EDT, 5 hours 8 minutes earlier.

Area forecast discussion, Jun 20, 2:30 PM EDT, 5 hours 8 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
230 PM EDT WED JUN 20 2001

CURRENTLY...SATELLITE WATER VAPOR IMAGERY SHOWED SHORT WAVE ENERGY
LIFTING NORTHEAST ACROSS THE AREA. THIS ENERGY WAS GENERATING
THUNDERSTORMS OVER THE ATLANTIC OFF THE FLORIDA/GEORGIA COAST. MSAS
ALSO SHOWED HAT GOOD CONVERGENCE WAS GENERATING SOME THUNDERSTORMS
ALONG THE EASTERN FLORIDA COAST...WITH THE THUNDERSTORMS BEING MORE
NUMEROUS OVER THE CENTRAL AND SOUTHERN FLORIDA COAST. THE GULF SEA
BREEZE WAS BEGINNING TO BEGINNING TO MAKE SOME MOVEMENT...WITH SOME
SHOWERS BEGINNING TO DEVELOP ALONG THE I-75 CORRIDOR. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO INCREASE ACROSS THE AREA DURING THE
NEXT HOUR OR TWO WITH BOTH SEABREEZES BEGINNING TO COME INTO
PLAY...SO EXPECT PRETTY MUCH A REPEAT OF TUESDAY.

FOR THE REMAINDER OF THE PACKAGE IT SEEMS LIKE MORE OF THE SAME WITH
SEABREEZE INTERACTION PRODUCING AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS. AFTERNOON HIGH TEMPERATURES WILL RANGE IN THE UPPER
80S AND LOWER 90S...WITH OVERNIGHT LOWS RANGING FROM THE UPPER 60S
TO MID 70S. A COLD FRONT WILL APPROACH THE AREA BY LATE WEEK...BUT
WILL PROBABLY DISSIPATE ACROSS OR JUST NORTH OF THE AREA.

PRELIM
AMG 70/92/69/89 4334
SSI 73/88/72/86 3334
JAX 71/90/71/90 3434
GNV 70/92/70/90 3334 33

.JAX...
FL...NONE.
GA...NONE.

BLS

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 20, 7:01 PM EDTSevere Thunderstorm WarningJAXMarion44 min

Nearby

Severe Thunderstorm Warnings in Florida, 2001Every severe thunderstorm warning in 2001

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; radar from the NEXRAD Level II archive.