Alert archive / Florida / Special Weather Statements in 2017

Special Weather Statement, NWS Melbourne, FL

June 30, 2017Okeechobee County, Florida

NWS Melbourne, FL issued this special weather statement at Jun 30, 2017, 4:17 PM EDT for Okeechobee County, Florida. It was in force for 43 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
Jun 30, 2017, 4:17 PM EDT (20:17 UTC)
Expired
Jun 30, 2017, 5:00 PM EDT
In force
43 min
Issued by
NWS Melbourne, FL

County Okeechobee County, FL

The radar

The Melbourne radar (KMLB), 72 km from the middle of the area, began a volume at 20:20 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, 8.3 hours before the alert went out and 114 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, Cape Canaveral, FL at 12:00Z on 2017-06-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1757 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Cape Canaveral, FL at 12:00Z on 2017-06-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -45 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
1757 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
740 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-45 m²/s²
0-3 km storm-relative helicity
-27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

What forecasters said that day

The local office's own words before this special weather statement 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 special weather statement went out at Jun 30, 3:55 PM EDT, 22 minutes earlier.

Area forecast discussion, Jun 30, 3:55 PM EDT, 22 minutes before
Area Forecast Discussion
National Weather Service Melbourne FL
355 PM EDT Fri Jun 30 2017

.DISCUSSION...

Through tonight...Late morning Cape sounding shows temps aloft
have cooled a bit to -7C with precip water values of 1.9 inches.
Early start to the convection has produced numerous boundary
collisions already resulting in frequent lightning and heavy
rains just inland from the east coast. The sounding also suggests
the possibility of wet microbursts. Expect a collision over the
north interior with the west coast breeze in a few hours near Lake
county. There is a potential for storms or some debris rain to
push back to the volusia coast this evening where steering flow is
a little more steadily toward the E/NE. All activity should
diminish by midnight.

Saturday...High pressure ridge axis will be draped across central
FL peninsula and adjacent Atlc and produce a light south to
southwest flow turning onshore in a E/SE sea breeze near the
coast. Atmosphere will remain quite moist with precip water values
around 2 inches so expect the east coast sea breeze to become
active with scattered showers/storms by early afternoon. Focus for
storms will remain over the north interior during the late
afternoon so will hold onto likely (60 percent) PoPs Orlando
northward. Steering flow should bring some of the activity back to
the coast from the Cape northward. Quicker inland penetration of
the sea breeze along the Treasure coast of Martin and Saint Lucie
will limit rain chances to 30 percent.

High temperatures will reach the low to mid 90s over the interior
and near 90 beaches with peak heat indices around 105.

Sunday and Monday...Low-level high pressure ridge axis remaining
just to our south will keep winds southerly during the late morning
and early afternoon before the east coast sea breeze moves inland
each afternoon. PWATs approaching 2 inches along with 500 mb
temperatures between -7 and -8 Celsius will support showers and
thunderstorms with the best chances again favoring the interior
locations. The main storms threats will be frequent lightning
strikes, localized very heavy rainfall, and gusty downburst winds.

Max temps will remain in the low 90s inland and closer to 90 near
the coast. Lows will be in the mid 70s with some lower 70s in some
of the usual cooler spots.

&&

.AVIATION...High coverage of storms expected over the interior
terminals through 00Z, possibly pushing back toward DAB through
02Z. Then quiet overnight thru at least 14Z with convection
bubbling up once again as the east coast sea breeze redevelops and
sparks isolated to scattered SHRA/TSRA along or just inland from
the coast, with higher coverage expected over the interior after
18Z.

&&

.MARINE...
Ridge axis north of area will settle southward over the waters
through the weekend and into early next week. Light winds and
minimal seas will prevail outside of daily convection. Winds
generally S/SW over Volusia/Brevard waters except for afternoon
sea breezes near shore. Farther south, winds mostly light SE. Seas
1-2 feet nearshore and 2-3 feet offshore.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  75  91  74  90 /  30  50  30  50
MCO  75  93  75  93 /  30  60  30  60
MLB  76  90  75  89 /  20  40  20  40
VRB  75  89  74  90 /  20  40  20  40
LEE  76  92  76  93 /  40  60  30  60
SFB  75  93  76  93 /  30  60  30  60
ORL  76  93  76  93 /  30  60  30  60
FPR  75  90  73  90 /  20  30  20  40

&&

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

&&

SHORT TERM...Kelly
IMPACT WEATHER/DSS....Ulrich
AVIATION/MID TERM...Combs
Hazardous weather outlook, Jun 30, 1:00 PM EDT, 3 hours 17 minutes before
Hazardous Weather Outlook
National Weather Service Melbourne FL
100 PM EDT Fri Jun 30 2017

AMZ550-552-555-570-572-575-FLZ041-044>047-053-054-058-059-064-141-
144-147-010000-
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-
100 PM EDT Fri Jun 30 2017

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

.THUNDERSTORM IMPACT...
Scattered lightning storms are expected through the remainder of the
afternoon, with the highest concentration expected away from the
coast.

Storm motion will be slow and erratic. Cloud to ground lightning and
heavy rainfall amounts between one and three inches in a 60 to 90
minute period will be the main storm threats. Brief gusty winds to
30 or 40 mph we also be possible.

.MARINE THUNDERSTORM GUST IMPACT...
Thunderstorms could produce wind gusts up to 35 knots over large
inland lakes this afternoon.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.
Scattered to locally numerous lightning storms are forecast to
continue through this weekend as well as the Fourth of July
holiday. Storm coverage will remain a little higher over the
interior and northern counties. The primary threats will be
dangerous lightning strikes and locally heavy rainfall, along
with some brief gusty winds.

.SPOTTER INFORMATION STATEMENT...
Spotter activation will not be needed today. However, spotters
are requested to report rainfall amounts of greater than 2 inches
or any observed flooding.

Cristaldi/Ulrich

In the hours before

Special weather statement, Jun 30, 4:17 PM EDT, 0 minutes before
Special Weather Statement
National Weather Service Melbourne FL
417 PM EDT FRI JUN 30 2017

FLZ058-302100-
Okeechobee FL-
417 PM EDT FRI JUN 30 2017

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN OKEECHOBEE COUNTY
UNTIL 500 PM EDT...

At 416 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles southeast of Fort Drum. This storm was nearly stationary.

Winds in excess of 40 mph will be possible with this storm.

This storm will remain over mainly rural areas of northeastern
Okeechobee County.

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 is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2759 8078 2756 8078 2756 8068 2726 8068
      2726 8079
TIME...MOT...LOC 2016Z 210DEG 4KT 2746 8070

Combs

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 29, 8:23 PM EDTSpecial Weather StatementMLBLake52 min
Jun 29, 8:39 PM EDTAreal Flood AdvisoryMLBLake96 min
Jun 30, 4:59 PM EDTSpecial Weather StatementMLBOrange46 min
Jun 30, 5:21 PM EDTSevere Thunderstorm WarningMLBOrange, Osceola28 min
Jun 30, 5:37 PM EDTSpecial Weather StatementMLBLake38 min

Nearby

Special Weather Statements in Florida, 2017Every special weather statement 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.