Alert archive / Florida / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 23, NWS Melbourne, FL

April 4, 2017Indian River County, Okeechobee County, Osceola County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 4, 2017, 4:07 PM EDT for Indian River County, Okeechobee County, Osceola County, Florida. It was in force for 38 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: Apr 4, 2017, 4:07 PM EDT (20:07 UTC)
Expired: Apr 4, 2017, 4:45 PM EDT
In force: 38 min
Issued by: NWS Melbourne, FL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Indian River County, FL, Okeechobee County, FL, Osceola County, FL

The radar

The Melbourne radar (KMLB), 58 km from the middle of the area, began a volume at 20:10 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 8.1 hours before the alert went out and 100 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: 1001 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 699 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 183 m²/s²
Significant tornado parameter: 0.8
Supercell composite: 5.4

Open this sounding in Storm Lab

The text

As transmitted.

865 
WUUS52 KMLB 042007
SVRMLB
FLC061-093-097-042045-
/O.NEW.KMLB.SV.W.0023.170404T2007Z-170404T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Melbourne FL
407 PM EDT TUE APR 4 2017

The National Weather Service in Melbourne has issued a

* Severe Thunderstorm Warning for...
  Northeastern Okeechobee County in east central Florida...
  Southwestern Indian River County in east central Florida...
  Southeastern Osceola County in east central Florida...

* Until 445 PM EDT

* At 407 PM EDT, a severe thunderstorm was located 9 miles northwest
  of Fort Drum, moving east-southeast at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Fort Drum.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 2756 8068 2751 8068 2746 8084 2757 8098
      2765 8110 2778 8104 2777 8091 2766 8056
      2756 8055
TIME...MOT...LOC 2007Z 288DEG 23KT 2764 8088 

HAIL...1.00IN
WIND...60MPH
 
$$

Sedlock

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 Melbourne, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 4, 10:00 AM EDT, 6 hours 7 minutes earlier.

Area forecast discussion, Apr 4, 10:00 AM EDT, 6 hours 7 minutes before

Area Forecast Discussion
National Weather Service Melbourne FL
10 AM EDT Tue Apr 4 2017

.DISCUSSION...

Strong divergence aloft is supporting a band of strong storms across
north FL shifting south toward greater instability over north
Lake/Volusia counties. The divergence is forecast to weaken
considerably by afternoon so the threat for strong/isolated severe
storms will be over Lake and Volusia counties through noon to 1 pm.
Updated the forecast to increase PoPs for Lake and Volusia and lower
max temps based on clouds and precip.

&&

.AVIATION...Primary concern is band of storms slipping south toward
LEE/DAB/SFB with potential for gusty downburst winds and frequent
lightning through 16-17Z.

&&

.MARINE...
Today...small craft exercise caution over much of the waters today
as south winds up to 15-20 knots will persist with seas 4-6 feet.

&

.CLIMATE...
Daytona Beach, Orlando and Melbourne broke their record warm minimum
temperature yesterday, April 3rd. Additional high and warm low
temperature records may be set or tied today and Wednesday.

Current High and Warm Low Temperature Records for the 4th and 5th:

LOC  DATE   HI-MAX   HI-MIN
DAB 4-Apr  93 1974  70 1991
MCO 4-Apr  93 1918  69 1974
MLB 4-Apr  92 1977  71 1974
VRB 4-Apr  92 2012  73 1960

DAB 5-Apr  90 1957  70 1954
MCO 5-Apr  91 1999  68 1957
MLB 5-Apr  91 1977  72 1957
VRB 5-Apr  90 1977  73 1957

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  89  69  90  68 /  30  10  10  50
MCO  92  69  92  69 /  20  10  10  40
MLB  92  71  90  71 /  10  10  10  30
VRB  90  71  89  70 /  10  10  10  30
LEE  88  70  92  68 /  30  10  10  50
SFB  92  70  93  68 /  30  10  10  40
ORL  92  71  92  70 /  20  10  10  40
FPR  90  70  89  69 /  10  10  10  20

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.

&&

Kelly/Sedlock

Hazardous weather outlook, Apr 4, 4:39 AM EDT, 11 hours 28 minutes before

Hazardous Weather Outlook
National Weather Service Melbourne FL
439 AM EDT Tue Apr 4 2017

AMZ550-552-555-570-572-575-FLZ041-044>047-053-054-058-059-064-141-
144-147-042045-
Flagler Beach to Volusia-Brevard County Line 0-20 nm-Volusia-
Brevard County Line to Sebastian Inlet 0-20 nm-
Sebastian Inlet to Jupiter Inlet 0-20 nm-Flagler Beach to Volusia-
Brevard County Line 20-60 nm-Volusia-
Brevard County Line to Sebastian Inlet 20-60 nm-
Sebastian Inlet to Jupiter Inlet 20-60 nm-Inland Volusia County-
Northern Lake County-Orange-Seminole-Southern Brevard County-
Osceola-Indian River-Okeechobee-St. Lucie-Martin-
Coastal Volusia County-Southern Lake County-
Northern Brevard County-
439 AM EDT Tue Apr 4 2017

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

.THUNDERSTORM IMPACT...
Deeper moisture ahead of a stalled front north of the area, may
generate isolated to scattered showers and lightning storms across
north central Florida, mainly from late this morning into the
afternoon. While main threats will be dangerous cloud to ground
lightning and heavy downpours, isolated stronger storms could
develop and produce strong wind gusts up to 40 to 50 mph and small
hail. Storms will move toward the east-northeast up to 30 to 35
mph.

.RIP CURRENT IMPACT...
A moderate risk for rip currents will continue at the beaches of
east central Florida today. Always swim within sight of a
lifeguard and never swim alone.

.MARINE THUNDERSTORM GUST IMPACT...
Isolated thunderstorms that develop over north central Florida
this afternoon will move toward the east to northeast up to 25 to
30 knots. Any stronger storms will have the potential to produce
wind gusts around 34 knots or greater as they move offshore, north
of Melbourne.

.WIND AND SEA IMPACT...
Southerly winds up to 15 to 20 knots will continue across much of
the adjacent Atlantic waters today. Small craft should exercise
caution.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.
Isolated lightning storms will again be possible ahead of a
stronger cold front late Wednesday night into Thursday.

Poor to hazardous boating conditions will continue across the
coastal waters from mid to late week with the next frontal
passage.

.SPOTTER INFORMATION STATEMENT...
Spotter activation will not be needed today.

Weitlich

In the hours before

Special weather statement, Apr 4, 3:06 PM EDT, 1 hour 1 minute before

Special Weather Statement
National Weather Service Melbourne FL
306 PM EDT TUE APR 4 2017

FLZ047-041930-
Southern Brevard County FL-
306 PM EDT TUE APR 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL BREVARD COUNTY UNTIL 330
PM EDT...

At 305 PM EDT, Doppler radar was tracking a strong thunderstorm over
Suntree, or near Patrick Air Force Base, moving east at 20 mph.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Melbourne, Rockledge, Cocoa Beach, Satellite Beach and Patrick Air
Force Base.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning will be possible with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2815 8081 2833 8077 2834 8057 2816 8055
TIME...MOT...LOC 1905Z 261DEG 20KT 2823 8071

Sedlock

Local storm report, Apr 4, 3:07 PM EDT, 1 hour before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
307 PM EDT TUE APR 04 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0253 PM     HAIL             5 E CASSELBERRY         28.68N 81.25W
04/04/2017  M1.00 INCH       SEMINOLE           FL   TRAINED SPOTTER

            TRAINED SPOTTER MEASURED ONE INCH HAIL IN WINTER SPRINGS.

&&

KR

Special weather statement, Apr 4, 3:13 PM EDT, 54 minutes before

Special Weather Statement
National Weather Service Melbourne FL
313 PM EDT TUE APR 4 2017

FLZ053-058-042015-
Okeechobee FL-Osceola FL-
313 PM EDT TUE APR 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR WEST CENTRAL OKEECHOBEE AND
OSCEOLA COUNTIES UNTIL 415 PM EDT...

At 309 PM EDT, Doppler radar was tracking developing thunderstorms
along the west coast sea breeze near the Kissimmee River. This
boundary will collide with an outflow boundary advancing into
Osceola County from the east and ignite new, strong thunderstorms.
Movement should be towards the east at 20 to 25 mph.

Dime size hail and winds in excess of 40 mph will be possible with
any storms that develop through late afternoon.

Locations impacted include...
Kissimmee, Saint Cloud, Celebration, Lake Marian and Buena Ventura
Lakes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Torrential rainfall will be possible with any storm activity, and
may lead to localized flooding. Do not drive your vehicle through
flooded roadways.

Frequent cloud to ground lightning is also possible with any storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2722 8097 2736 8103 2739 8112 2749 8120
      2755 8121 2760 8114 2771 8115 2783 8122
      2786 8130 2806 8146 2801 8138 2808 8135
      2809 8145 2814 8146 2814 8152 2826 8156
      2826 8166 2834 8166 2834 8090 2715 8087
TIME...MOT...LOC 1909Z 278DEG 25KT 2771 8105

Sedlock

Local storm report, Apr 4, 3:24 PM EDT, 43 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
324 PM EDT TUE APR 04 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0255 PM     HAIL             5 ENE CASSELBERRY       28.69N 81.24W
04/04/2017  M1.00 INCH       SEMINOLE           FL   AMATEUR RADIO

            HAM RADIO OPERATOR MEASURED QUARTER-SIZED HAIL ABOUT 0.75
            MILES WEST OF THE INTERSECTION OF SR-417 AND SR-434 IN
            WINTER SPRINGS

&&

KR

Special weather statement, Apr 4, 3:37 PM EDT, 30 minutes before

Special Weather Statement
National Weather Service Melbourne FL
337 PM EDT TUE APR 4 2017

FLZ047-042000-
Southern Brevard County FL-
337 PM EDT TUE APR 4 2017

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL BREVARD COUNTY UNTIL
400 PM EDT...

At 336 PM EDT, Doppler radar was tracking a strong thunderstorm near
South Patrick Shores, or near Satellite Beach, moving slowly east-
southeast.

Dime size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Palm Bay, Melbourne, Satellite Beach, Indialantic and Patrick Air
Force Base.

LAT...LON 2808 8072 2824 8072 2826 8056 2813 8054
      2802 8049
TIME...MOT...LOC 1936Z 272DEG 28KT 2817 8066

Sedlock

Local storm report, Apr 4, 3:50 PM EDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
350 PM EDT TUE APR 04 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0346 PM     TSTM WND GST     MELBOURNE AIRPORT       28.10N 80.64W
04/04/2017  M43 MPH          BREVARD            FL   ASOS

&&

PG

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 4, 10:07 AM EDT	Special Marine Warning	MLB		3 hr
Apr 4, 10:54 AM EDT	Special Weather Statement	MLB	Volusia	36 min
Apr 4, 12:07 PM EDT	Special Marine Warning	MLB		53 min
Apr 4, 12:34 PM EDT	Special Weather Statement	MLB	Lake	56 min
Apr 4, 1:12 PM EDT	Severe Thunderstorm Warning	MLB	Lake, Orange	63 min
Apr 4, 2:11 PM EDT	Severe Thunderstorm Warning	MLB	Orange, Seminole	49 min
Apr 4, 2:49 PM EDT	Severe Thunderstorm Warning	MLB	Brevard, Orange, Seminole, Volusia	56 min
Apr 4, 3:04 PM EDT	Special Marine Warning	MLB		116 min
Apr 4, 3:06 PM EDT	Special Weather Statement	MLB	Brevard	24 min
Apr 4, 3:13 PM EDT	Special Weather Statement	MLB	Okeechobee, Osceola	62 min
Apr 4, 3:37 PM EDT	Special Weather Statement	MLB	Brevard	23 min
Apr 4, 3:41 PM EDT	Special Marine Warning	MLB		64 min
Apr 4, 3:41 PM EDT	Severe Thunderstorm Warning	MLB	Brevard	49 min
Apr 4, 4:08 PM EDT	Severe Thunderstorm Warning	MLB	Osceola	67 min
Apr 4, 4:12 PM EDT	Special Weather Statement	MLB	Indian River	48 min
Apr 4, 4:24 PM EDT	Special Weather Statement	MLB	Indian River	66 min
Apr 4, 4:42 PM EDT	Severe Thunderstorm Warning	MLB	Indian River	35 min
Apr 4, 4:44 PM EDT	Special Marine Warning	MLB		91 min
Apr 4, 6:01 PM EDT	Special Weather Statement	MLB	Okeechobee	59 min

Nearby

Severe Thunderstorm Warnings in Florida, 2017 Every severe thunderstorm warning in 2017

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.