Alert archive / Florida / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 95, NWS Melbourne, FL

July 21, 2011Orange County, Seminole County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Jul 21, 2011, 7:24 PM EDT for Orange County, Seminole County, Florida. It was in force for 41 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 21, 2011, 7:24 PM EDT (23:24 UTC)
Expired: Jul 21, 2011, 8:05 PM EDT
In force: 41 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon

Counties Orange County, FL, Seminole County, FL

The radar

The Melbourne radar (KMLB), 93 km from the middle of the area, began a volume at 23:27 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

Cape Canaveral, FL (KXMR), launched 12:00Z, 11.4 hours before the alert went out and 92 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: 382 J/kg
Mixed-layer CIN: -81 J/kg
Mixed-layer LCL: 1083 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

846 
WUUS52 KMLB 212324
SVRMLB
FLC095-117-220015-
/O.NEW.KMLB.SV.W.0095.110721T2324Z-110722T0015Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
724 PM EDT THU JUL 21 2011

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN AND CENTRAL ORANGE COUNTY IN FLORIDA
  WESTERN SEMINOLE COUNTY IN FLORIDA

* UNTIL 815 PM EDT.

* AT 723 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 58 MPH.  THIS STORM WAS LOCATED NEAR ORLANDO...AND MOVING NORTH
  AT 5 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED TO...
  AZALEA PARK...ORLOVISTA...WINTER PARK...WEKIWA SPRINGS STATE
  PARK...WEKIVA SPRINGS...PINE HILLS...MAITLAND...LONGWOOD...
  LOCKHART...LAKE MARY...GOLDENROD...FOREST CITY...FERN PARK...
  FAIRVIEW SHORES...CASSELBERRY...APOPKA AND ALTAMONTE SPRINGS

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 58 MILES AN
HOUR AND OR LARGE DESTRUCTIVE HAIL. FREQUENT TO EXCESSIVE LIGHTNING
AND VERY HEAVY RAIN WILL ALSO BE POSSIBLE. IF THE STORM APPROACHES
YOU...SEEK SHELTER IN AN ENCLOSED BUILDING ON THE LOWEST FLOOR. KEEP
AWAY FROM WINDOWS.

&&

LAT...LON 2864 8153 2879 8157 2878 8133 2838 8119
      2839 8141
TIME...MOT...LOC 2323Z 176DEG 4KT 2852 8136

$$


15

1 follow-up statement

701 
WWUS52 KMLB 220005
SVSMLB

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
805 PM EDT THU JUL 21 2011

FLC095-117-220015-
/O.CAN.KMLB.SV.W.0095.000000T0000Z-110722T0015Z/
SEMINOLE-ORANGE-
805 PM EDT THU JUL 21 2011

...THE SEVERE THUNDERSTORM WARNING FOR WESTERN AND CENTRAL ORANGE 
AND WESTERN SEMINOLE COUNTIES IS CANCELLED...

THE SEVERE STORM THAT PROMPTED THE WARNING HAD WEAKENED AND WAS NO
LONGER CAPABLE OF PRODUCING LARGE HAIL OR DAMAGING WINDS. AS A
RESULT...THE WARNING HAS BEEN CANCELLED. HOWEVER...HEAVY RAIN AND 
DANGEROUS LIGHTNING STRIKES WILL CONTINUE TO BE POSSIBLE ACROSS THE 
ORLANDO AREA.

LAT...LON 2864 8153 2879 8157 2878 8133 2838 8119
      2839 8141
TIME...MOT...LOC 0005Z 176DEG 4KT 2857 8136

$$


15

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 3:21 PM EDT	Special Weather Statement	MLB	Indian River	39 min
Jul 21, 7:35 PM EDT	Special Weather Statement	MLB	Lake	40 min
Jul 21, 7:36 PM EDT	Areal Flood Advisory	MLB	Lake, Orange, Seminole	84 min
Jul 21, 7:52 PM EDT	Severe Thunderstorm Warning	MLB	Lake	22 min

Nearby

Severe Thunderstorm Warnings in Florida, 2011 Every severe thunderstorm warning in 2011

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.