Alert archive / Florida / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 13, NWS Melbourne, FL

April 20, 2012Lake County, Volusia County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 20, 2012, 5:04 PM EDT for Lake County, Volusia County, Florida. It was in force for 56 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Apr 20, 2012, 5:04 PM EDT (21:04 UTC)
Expired: Apr 20, 2012, 6:00 PM EDT
In force: 56 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon

Counties Lake County, FL, Volusia County, FL

The radar

The Melbourne radar (KMLB), 129 km from the middle of the area, began a volume at 21:05 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

Time	Report	Where	Remark
Apr 20, 5:17 PM EDT	TSTM WND DMG	4 Wnw Astor Park, FL	RADAR ANALYSIS AND INFORMATION FROM EMERGENCY MANAGEMENT INDICATES STRAIGHT-LINE WINDS FROM A SEVERE THUNDERSTORM PRODUCED WIND DAMAGE ALONG HIGHWAY 40...JUST EAST OF HIGHWAY 19. SEVERAL TREES WERE DOWNED...SOME TOPPLED ONTO HIGHWAY 40. WINDS ESTIMATED NEAR 60
Apr 20, 5:25 PM EDT	HAIL 0.88	6 Wnw Deltona, FL	SKYWARN SPOTTER OBSERVED NICKEL SIZE HAIL IN ORANGE CITY ONE BLOCK SOUTH OF INTERSECTION OF 17 92 AND RHODE ISLAND AVE.
Apr 20, 5:35 PM EDT	TSTM WND DMG	3 Se Deltona, FL	PIN TREE FELL ON HOME FORT SMITH BLVD. TIME ESTIMATED FROM RADAR.
Apr 20, 5:45 PM EDT	HAIL 1.75	Deltona, FL	PUBLIC REPORTED GOLF BALL SIZED HAIL.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 9.1 hours before the alert went out and 108 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: 414 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 861 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 22 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.

880 
WUUS52 KMLB 202104
SVRMLB
FLC069-127-202200-
/O.NEW.KMLB.SV.W.0013.120420T2104Z-120420T2200Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
504 PM EDT FRI APR 20 2012

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN LAKE COUNTY IN FLORIDA
  VOLUSIA COUNTY IN FLORIDA

* UNTIL 600 PM EDT.

* AT 503 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED  
  SEVERE THUNDERSTORMS CAPABLE OF PRODUCING QUARTER SIZE HAIL...
  AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORMS WERE LOCATED
  NEAR DELAND AND ALEXANDER SPRINGS...MOVING EAST AT 20 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE...BUT ARE NOT LIMITED 
TO...  
PAISLEY...HONTOON SPRINGS...LAKE HELEN....ORANGE CITY AND 
DELTONA.
   
PRECAUTIONARY/PREPAREDNESS ACTIONS...

HAIL UP TO THE SIZE OF QUARTERS HAS BEEN REPORTED WITH EARLIER 
STORMS...AND LARGE HAIL IS POSSIBLE WITH THESE STORMS.  IF YOU ARE 
IN THE PATH OF THE STORM...TAKE IMMEDIATE ACTION TO PROTECT LIFE AND 
PROPERTY.

&&

LAT...LON 2908 8093 2908 8091 2892 8083 2882 8122
      2884 8133 2888 8137 2884 8140 2886 8158
      2896 8169 2897 8166 2905 8166 2905 8164
      2928 8165 2932 8168 2938 8145 2940 8142
      2927 8141 2927 8116 2941 8116 2942 8109
TIME...MOT...LOC 2059Z 259DEG 16KT 2899 8125

$$


52

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 20, 3:06 PM EDT	Severe Thunderstorm Warning	MLB	Lake, Orange	38 min
Apr 20, 3:56 PM EDT	Special Weather Statement	MLB	Lake, Orange, Osceola, Seminole	64 min
Apr 20, 4:08 PM EDT	Severe Thunderstorm Warning	MLB	Indian River	67 min
Apr 20, 4:09 PM EDT	Severe Thunderstorm Warning	MLB	Orange, Osceola	66 min
Apr 20, 4:15 PM EDT	Special Marine Warning	MLB		2 hr
Apr 20, 4:19 PM EDT	Special Weather Statement	MLB	Martin	41 min
Apr 20, 4:22 PM EDT	Severe Thunderstorm Warning	MLB	Osceola	53 min
Apr 20, 4:29 PM EDT	Special Weather Statement	MLB	Volusia	61 min
Apr 20, 4:35 PM EDT	Severe Thunderstorm Warning	MLB	Volusia	55 min
Apr 20, 4:43 PM EDT	Severe Thunderstorm Warning	MLB	Okeechobee	62 min
Apr 20, 5:20 PM EDT	Special Weather Statement	MLB	Indian River	40 min
Apr 20, 5:34 PM EDT	Special Marine Warning	MLB		116 min
Apr 20, 5:34 PM EDT	Severe Thunderstorm Warning	MLB	Brevard, Osceola	56 min
Apr 20, 5:39 PM EDT	Severe Thunderstorm Warning	MLB	Indian River, Saint Lucie	66 min
Apr 20, 5:59 PM EDT	Special Marine Warning	MLB		2 hr
Apr 20, 6:36 PM EDT	Severe Thunderstorm Warning	MLB	Brevard, Orange, Seminole, Volusia	54 min
Apr 20, 6:49 PM EDT	Special Weather Statement	MLB	Martin	56 min
Apr 20, 7:37 PM EDT	Special Weather Statement	MLB	Brevard	53 min
Apr 20, 7:49 PM EDT	Special Marine Warning	MLB		41 min

Nearby

Severe Thunderstorm Warnings in Florida, 2012 Every severe thunderstorm warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.