Alert archive / Florida / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 114, NWS Miami, FL

July 10, 2009Glades County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Jul 10, 2009, 6:36 PM EDT for Glades County, Florida. It was in force for 54 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 10, 2009, 6:36 PM EDT (22:36 UTC)
Expired: Jul 10, 2009, 7:30 PM EDT
In force: 54 min
Issued by: NWS Miami, FL
Area: Storm-based polygon

County Glades County, FL

The radar

The Melbourne radar (KMLB), 139 km from the middle of the area, began a volume at 22:38 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, 10.6 hours before the alert went out and 181 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: 111 J/kg
Mixed-layer CIN: -152 J/kg
Mixed-layer LCL: 1430 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 102 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

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 Miami, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 10, 2:21 PM EDT, 4 hours 15 minutes earlier.

Area forecast discussion, Jul 10, 2:21 PM EDT, 4 hours 15 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
221 PM EDT FRI JUL 10 2009

.DISCUSSION...ABUNDANT MID TO HIGH LEVEL CLOUDS HAVE INHIBITED
CONVECTIVE ACTIVITY AND ANY TSRA WILL LIKELY BE DELAYED IN
DEVELOPING. STILL COULD GET STRONG IF ENOUGH HEATING CAN GET
UNDERWAY WITH TEMPERATURES NOW APPROACHING 90 DEGREES COASTAL AREAS
AND LOWER 90S INTERIOR. SO IT WILL NOT TAKE MUCH MORE HEATING TO
GET GOING CONSIDERING THE LOW LEVEL INSTABILITY. THUS, FEEL A
LITTLE HESITANT IN LOWERING AFTERNOON POPS AND THIS COULD EASILY
LAST WELL INTO THE EVENING HOURS. ALTHOUGH SINCE CONVECTION HAS
NOT STARTED YET AND IT IS ALREADY MID AFTERNOON, DID LOWER BY 10
PERCENT EVERYWHERE. ANOTHER VERY ODD FEATURE SHOWING UP IS SOME
FORM OF WEAK SURFACE BOUNDARY MOVING SOUTH OF LAKE OKEECHOBEE. YOU
CAN BARELY MAKE OUT THIS BOUNDARY ON VISIBLE SATELLITE IMAGERY AND
AS IT PASSED PBI THEIR WIND SHIFTED TO THE NORTHWEST. AM A LITTLE
PERPLEXED AS TO WHAT IS CAUSING THIS BOUNDARY SINCE IT DOES NOT
APPEAR ANYWHERE ELSE WITH OTHER SURFACE OBSERVATIONS, BUT
NONETHELESS IT IS THERE AND IT COULD INTERACT VERY EASILY WITH THE
EAST COAST SEA BREEZE. SO ANOTHER RELUCTANT FACTOR IN REDUCING
AFTERNOON POPS BY TOO MUCH. AFTER THE FIRST PERIOD, ALL MODELS
AGREE THAT DEEP LAYER RIDGE WILL BUILD IN ACROSS SOUTH FLORIDA AS
MID LEVEL RIDGE FINALLY ERODES. WITH THE RIDGE BUILDING IN OVER
THE AREA, BOTH THE GFS AND NAM FORECAST SOUNDINGS SHOW VERY WEAK
WIND FIELDS THROUGH EARLY NEXT WEEK AND THUS HAVE STORM MOTION OF
LESS THAN 5 KNOTS. SO LOOKS AS IF THE WEEKEND WILL HAVE MOSTLY SEA
BREEZE DRIVEN CONVECTION AND LOCALLY HEAVY RAINFALL WILL CONTINUE
TO BE A THREAT FOR WHEREVER THE STORMS SET UP. IN ADDITION, WILL
BEGIN TO ADVERTISE LOWER CHANCES FOR RAINFALL WITH THE RIDGE
BUILDING IN. THE GFS IS SHOWING 50H TEMPERATURES WARMING BY
SEVERAL DEGREES INTO EARLY NEXT WEEK. BY TUESDAY, THE GFS SHOWS
THE RIDGE BUILDS TO ABOUT CENTRAL FLORIDA PUTTING SOUTH FLORIDA
UNDER DEEP EASTERLY FLOW SHIFTING THE HIGHEST POPS TO THE WEST
COAST FOR A COUPLE OF DAYS AND THEN THE RIDGE SLIPS BACK TO THE
SOUTH ON THURSDAY AS THE NEXT IN A SERIES OF SHORT WAVES DIGS INTO
THE SOUTHEAST STATES.

&&

.MARINE...WIND AND SEAS WILL REMAIN QUITE TRANQUIL THROUGH THE
PERIOD WITH LESS THAN 4 FEET ON THE SEA HEIGHTS.

&&

.FIRE WEATHER...NO PROBLEMS OR CONCERNS.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  75  89  76  88 / 30 30 20 30
FORT LAUDERDALE  79  90  79  89 / 30 30 20 30
MIAMI            78  91  78  89 / 30 30 20 30
NAPLES           73  92  74  91 / 20 30 20 30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

LONG TERM...30/KOB
SHORT TERM/AVIATION...54/BNB

Hazardous weather outlook, Jul 10, 9:43 AM EDT, 8 hours 53 minutes before

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In the hours before

Special weather statement, Jul 10, 6:31 PM EDT, 5 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
631 PM EDT FRI JUL 10 2009

FLZ063-102245-
GLADES FL-
631 PM EDT FRI JUL 10 2009

...STRONG THUNDERSTORM MOVING ACROSS EAST GLADES COUNTY...

AT 630 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM 7 MILES NORTHWEST OF MOORE HAVEN...MOVING
SOUTHEAST AT 5 MPH.

FREQUENT TO EXCESSIVE LIGHTNING...GUSTY WINDS TO 50 MPH...DIME-SIZED
HAIL...TORRENTIAL DOWNPOURS...OR A COMBINATION OF THESE ARE POSSIBLE.
LIGHTNING IS THE NUMBER ONE WEATHER RELATED KILLER IN FLORIDA. TREES
AND OPEN SHELTERS OFFER NO PROTECTION. WIND GUSTS OF UP TO 50 MPH CAN
DOWN SMALL TREE LIMBS AND BRANCHES...AND BLOW AROUND UNSECURED SMALL
OBJECTS. SEEK SHELTER IN A SAFE BUILDING UNTIL THE STORM PASSES.

LAT...LON 2681 8104 2679 8120 2689 8127 2694 8119
TIME...MOT...LOC 2231Z 311DEG 5KT 2688 8120

TINGLER

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 9, 8:31 PM EDT	Special Weather Statement	MFL	Broward	29 min
Jul 9, 9:51 PM EDT	Special Weather Statement	MFL	Monroe	24 min
Jul 10, 4:43 AM EDT	Special Marine Warning	MFL		62 min
Jul 10, 5:13 AM EDT	Special Marine Warning	MFL		54 min
Jul 10, 6:31 PM EDT	Special Weather Statement	MFL	Glades	14 min
Jul 10, 7:09 PM EDT	Severe Thunderstorm Warning	MFL	Glades, Hendry	66 min
Jul 10, 7:11 PM EDT	Special Marine Warning	MFL		94 min
Jul 10, 7:38 PM EDT	Severe Thunderstorm Warning	MFL	Glades, Hendry, Palm Beach	40 min

Nearby

Severe Thunderstorm Warnings in Florida, 2009 Every 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.