Alert archive / Florida / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 44, NWS Miami, FL

May 20, 2012Palm Beach County, Florida

NWS Miami, FL issued this severe thunderstorm warning at May 20, 2012, 5:38 PM EDT for Palm Beach County, Florida. It was in force for 37 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: May 20, 2012, 5:38 PM EDT (21:38 UTC)
Expired: May 20, 2012, 6:15 PM EDT
In force: 37 min
Issued by: NWS Miami, FL
Area: Storm-based polygon

County Palm Beach County, FL

The radar

The Miami radar (KAMX), 115 km from the middle of the area, began a volume at 21:40 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

Miami, FL (KMFL), launched 12:00Z, 9.6 hours before the alert went out and 90 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: 982 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 629 m above ground
0-6 km bulk shear: 25 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 69 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

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

319 
WUUS52 KMFL 202138
SVRMFL
FLC099-202215-
/O.NEW.KMFL.SV.W.0044.120520T2138Z-120520T2215Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
538 PM EDT SUN MAY 20 2012

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN PALM BEACH COUNTY IN SOUTH FLORIDA.

* UNTIL 615 PM EDT

* AT 536 PM EDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 5 MILES
  SOUTH OF WELLINGTON...AND MOVING NORTHEAST AT 20 MPH.

* THE STORM WILL AFFECT...
  WELLINGTON...
  GREENACRES CITY...
  ROYAL PALM BEACH...
  GOLDEN LAKES...
  HAVERHILL...
  AND SURROUNDING COMMUNITIES.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 58 MPH AND
OR LARGE HAIL. FREQUENT TO EXCESSIVE LIGHTNING AND HEAVY RAINFALL IS
ALSO POSSIBLE. IF THE STORM APPROACHES YOUR LOCATION, SEEK SHELTER IN
AN ENCLOSED BUILDING ON THE LOWEST FLOOR AND STAY AWAY FROM WINDOWS.

&&

LAT...LON 2647 8027 2656 8038 2688 8030 2671 8003
      2666 8003
TIME...MOT...LOC 2138Z 217DEG 16KT 2661 8027

$$

MJB

2 follow-up statements

508 
WWUS52 KMFL 202152
SVSMFL

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
552 PM EDT SUN MAY 20 2012

FLC099-202215-
/O.CON.KMFL.SV.W.0044.000000T0000Z-120520T2215Z/
PALM BEACH FL-
552 PM EDT SUN MAY 20 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM EDT
FOR EAST CENTRAL PALM BEACH COUNTY...

AT 549 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING LARGE HAIL...AND
DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
WELLINGTON...MOVING NORTHEAST AT 20 MPH.

SEVERE THUNDERSTORMS CAN PRODUCE VERY STRONG WINDS IN EXCESS OF 58
MPH...LARGE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAINFALL. STAY
INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

SEVERE THUNDERSTORMS CAN ALSO PRODUCE TORNADOES WITH LITTLE OR NO
ADVANCE WARNING. PREPARE TO MOVE TO A PLACE OF SAFETY IN AN INTERIOR
ROOM IN THE LOWEST FLOOR OF YOUR HOUSE OR BUSINESS IF A TORNADO IS
SPOTTED.

LAT...LON 2652 8025 2656 8038 2688 8030 2671 8003
      2666 8003
TIME...MOT...LOC 2152Z 214DEG 17KT 2666 8023

$$

MJB

886 
WWUS52 KMFL 202211
SVSMFL

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
611 PM EDT SUN MAY 20 2012

FLC099-202219-
/O.EXP.KMFL.SV.W.0044.000000T0000Z-120520T2215Z/
PALM BEACH FL-
611 PM EDT SUN MAY 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL PALM BEACH COUNTY
WILL EXPIRE AT 615 PM EDT...

NATIONAL WEATHER SERVICE RADAR INDICATES THE THUNDERSTORM HAS 
WEAKENED. THUS THE THUNDERSTORM WARNING WILL EXPIRE AT 615 PM EDT.

HOWEVER, GUSTY WINDS AROUND 40 MPH, SMALL HAIL, AND HEAVY DOWNPOURS 
ARE STILL POSSIBLE AS THIS STORM MOVES TO THE NORTHEAST. 

LAT...LON 2652 8025 2656 8038 2688 8030 2671 8003
      2666 8003
TIME...MOT...LOC 2209Z 214DEG 17KT 2673 8018

$$

MJB

The office that day

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

Issued	Product	Office	Counties	Lasted
May 20, 5:18 PM EDT	Special Weather Statement	MFL	Broward	42 min
May 20, 5:21 PM EDT	Special Weather Statement	MFL	Palm Beach	39 min
May 20, 5:33 PM EDT	Severe Thunderstorm Warning	MFL	Broward, Palm Beach	42 min
May 20, 5:56 PM EDT	Special Weather Statement	MFL	Broward	49 min
May 20, 6:03 PM EDT	Areal Flood Advisory	MFL	Broward	64 min
May 20, 6:30 PM EDT	Special Weather Statement	MFL	Miami-Dade	30 min
May 20, 6:49 PM EDT	Special Marine Warning	MFL		86 min
May 20, 6:58 PM EDT	Special Weather Statement	MFL	Miami-Dade	62 min
May 20, 7:33 PM EDT	Special Weather Statement	MFL	Miami-Dade	57 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.