Alert archive / Florida / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 13, NWS Miami, FL

May 21, 2009Palm Beach County, Florida

NWS Miami, FL issued this severe thunderstorm warning at May 21, 2009, 1:34 AM EDT for Palm Beach 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
May 21, 2009, 1:34 AM EDT (05:34 UTC)
Expired
May 21, 2009, 2:15 AM EDT
In force
41 min
Issued by
NWS Miami, FL
Area
Storm-based polygon

County Palm Beach County, FL

The radar

The Miami radar (KAMX), 112 km from the middle of the area, began a volume at 05:37 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 00:00Z, 5.6 hours before the alert went out and 87 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, Miami, FL at 00:00Z on 2009-05-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 7 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Miami, FL at 00:00Z on 2009-05-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 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
7 J/kg
Mixed-layer CIN
-154 J/kg
Mixed-layer LCL
1797 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS52 KMFL 210534
SVRMFL
FLC099-210615-
/O.NEW.KMFL.SV.W.0013.090521T0534Z-090521T0615Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
134 AM EDT THU MAY 21 2009

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

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

* UNTIL 215 AM EDT

* AT 133 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED NEAR
  OCEAN RIDGE...AND MOVING NORTHWEST AT 15 MPH.

* THE STORM WILL AFFECT...
  OCEAN RIDGE...
  BOYNTON BEACH...
  LAKE WORTH...
  GREENACRES CITY...
  AND SURROUNDING COMMUNITIES.

SEVERE THUNDERSTORMS CAN PRODUCE VERY STRONG WINDS IN EXCESS OF 60
MPH...LARGE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAINFALL. STAY
INSIDE AWAY FROM WINDOWS UNTIL THE STORM HAS PASSED.

FREQUENT LIGHTNING IS OCCURRING WITH THIS THUNDERSTORM. IF
OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES AND
AVOID WATER. MOVE INDOORS OR INSIDE A VEHICLE IF POSSIBLE. AVOID
USING THE TELEPHONE UNLESS IT IS AN EMERGENCY. TRY TO UNPLUG
UNNECESSARY ELECTRICAL APPLIANCES BEFORE THE THUNDERSTORM APPROACHES.

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 2655 8004 2651 8004 2648 8005 2648 8006
      2664 8037 2681 8017 2665 8003 2655 8003
TIME...MOT...LOC 0534Z 137DEG 12KT 2653 8006

$$

DG
2 follow-up statements
193 
WWUS52 KMFL 210558
SVSMFL

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
158 AM EDT THU MAY 21 2009

FLC099-210615-
/O.CON.KMFL.SV.W.0013.000000T0000Z-090521T0615Z/
PALM BEACH FL-
158 AM EDT THU MAY 21 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 AM EDT
FOR EAST CENTRAL PALM BEACH COUNTY...

AT 157 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING PENNY SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED
NEAR ATLANTIS...MOVING NORTHWEST AT 15 MPH.

THE SEVERE THUNDERSTORM WILL BE NEAR...
ATLANTIS...
PALM SPRINGS...
GREENACRES CITY...
FLORIDA GARDENS...
AND SURROUNDING COMMUNITIES.

SEVERE THUNDERSTORMS CAN PRODUCE VERY STRONG WINDS IN EXCESS OF 60
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.

IN ADDITION TO LARGE HAIL AND DAMAGING WINDS...CONTINUOUS CLOUD TO
GROUND LIGHTNING IS OCCURRING WITH THIS STORM. MOVE INDOORS
IMMEDIATELY! LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS.
REMEMBER...IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE
STRUCK BY LIGHTNING.

REPORT SEVERE WEATHER OR DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY
OR YOUR COUNTY EMERGENCY MANAGEMENT. THEY WILL RELAY YOUR REPORT TO
THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN MIAMI. OR YOU CAN
ALSO CALL THE NATIONAL WEATHER SERVICE IN MIAMI DIRECTLY AT
305.229.4528 TO REPORT SEVERE WEATHER.

LAT...LON 2656 8005 2654 8006 2652 8007 2652 8009
      2664 8037 2681 8017 2665 8003
TIME...MOT...LOC 0558Z 137DEG 12KT 2659 8012

$$

DG
693 
WWUS52 KMFL 210611
SVSMFL

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
211 AM EDT THU MAY 21 2009

FLC099-210621-
/O.EXP.KMFL.SV.W.0013.000000T0000Z-090521T0615Z/
PALM BEACH FL-
211 AM EDT THU MAY 21 2009

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL PALM BEACH COUNTY
WILL EXPIRE AT 215 AM EDT...

NATIONAL WEATHER SERVICE RADAR INDICATED THAT THE THUNDERSTORM HAS
WEAKENED. THUS...THE SEVERE THUNDERSTORM WARNING WILL EXPIRE AT 
215 AM EDT.

HOWEVER...THUNDERSTORMS REMAIN IN THE AREA. FREQUENT 
LIGHTNING...GUSTY WINDS TO 40 MPH...VERY HEAVY RAINFALL AND SMALL 
HAIL ARE STILL POSSIBLE. STAY TUNED TO NOAA WEATHER RADIO OR LOCAL 
MEDIA FOR THE LATEST UPDATES.

LAT...LON 2656 8005 2654 8006 2652 8007 2652 8009
      2664 8037 2681 8017 2665 8003
TIME...MOT...LOC 0611Z 137DEG 12KT 2662 8015

$$

DG

The office that day

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

IssuedProductOfficeCountiesLasted
May 20, 8:27 PM EDTSpecial Marine WarningMFL63 min
May 20, 8:34 PM EDTSpecial Marine WarningMFL56 min
May 21, 12:11 AM EDTSpecial Marine WarningMFL64 min
May 21, 12:33 AM EDTSpecial Weather StatementMFLMartin27 min
May 21, 12:59 AM EDTSpecial Weather StatementMFLMartin31 min
May 21, 1:08 AM EDTSpecial Marine WarningMFL37 min
May 21, 1:12 AM EDTSpecial Marine WarningMFL63 min
May 21, 1:27 AM EDTSpecial Weather StatementMFLPalm Beach33 min
May 21, 1:31 AM EDTSpecial Marine WarningMFL119 min
May 21, 1:37 AM EDTSpecial Weather StatementMFLMartin38 min
May 21, 2:09 AM EDTSpecial Marine WarningMFL2 hr
May 21, 2:25 AM EDTSpecial Weather StatementMFLBroward50 min
May 21, 2:40 AM EDTSpecial Weather StatementMFLBroward35 min
May 21, 2:47 AM EDTSpecial Marine WarningMFL118 min
May 21, 3:03 AM EDTSpecial Weather StatementMFLPalm Beach57 min
May 21, 6:43 AM EDTSpecial Marine WarningMFL62 min
May 21, 9:22 AM EDTCoastal Flood StatementMFLBroward, Miami-Dade, Palm Beach11 hr
May 21, 10:10 AM EDTSpecial Weather StatementMFLBroward65 min
May 21, 10:12 AM EDTSpecial Weather StatementMFLBroward63 min
May 21, 10:43 AM EDTAreal Flood AdvisoryMFLBroward, Palm Beach107 min
May 21, 2:09 PM EDTSpecial Weather StatementMFLBroward66 min
May 21, 6:23 PM EDTSpecial Weather StatementMFLHendry52 min
May 21, 7:12 PM EDTSpecial Weather StatementMFLHendry63 min
May 21, 7:31 PM EDTSpecial Marine WarningMFL59 min
May 21, 7:58 PM EDTSpecial Weather StatementMFLPalm Beach62 min

Nearby

Severe Thunderstorm Warnings in Florida, 2009Every severe thunderstorm warning in 2009

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.