Special Weather Statement, NWS Melbourne, FL

Area Forecast Discussion
National Weather Service Melbourne FL
1028 AM EDT Thu Jun 21 2018

.DISCUSSION...

...Heat Indices Between 101 and 106 Areawide this Afternoon...

Current-Tonight...WFO MLB WSR-88D active early this morning showing
echoes across WCNTRL FL with some ISOLD activity occasionally moving
into the central peninsula. Local HRRR model shows this trend of
convection pushing eastward into the ECFL thru late morning/early
afternoon, especially near/north of I-4. 915 MHZ Cape wind profilers
show fairly deep westerly flow, but light with wind speeds averaging
around 10 kts. The 10Z KXMR sounding has come in with a PWAT of 2.13
inches, but with a warm 500 mb temperature of -5.2C. Models show
forecast temperatures at -6.0C to -6.5C at this level which is still
relatively warm.

The ECSB does not appear to develop today at least north of the
Cape. Should it develop southward along the Space Coast or Treasure
Coast, then it will likely be pinned along the coast without much or
little movement inland. The WCSB will be the main player today with
convection pushing from WCNTRL FL eastward into the eastern
peninsula during the afternoon and early evening. Coverage should be
highest late afternoon into early evening through additional
boundary collisions, and perhaps pulsing near the east coast should
the ECSB develop. Main concerns continue to be torrential downpours,
cloud to ground lightning, small hail, and gusty downburst winds up
to around 45 mph. Fairly high PoPs areawide around 50pct.

A hot day in store with afternoon highs in the L90s. Combined
temperature/moisture readings will push apparent temperatures/heat
indices in the 101 to 106 range areawide. Lows remain warm in the L-
M70s with conditions sultry.

&&

.AVIATION...Convection getting an early start along the I-4 corridor
with activity pushing eastward across the area from WCNTRL this
morning. This trend will continue into early afternoon. Some tempo
groups for IFR/MVFR conditions necessary for KLEE to KDAB and down
to KISM/KMCO/KSFB and KTIX. Additional tempo reductions in cig/vis
during the afternoon and early evening as the WCSB promotes
development of scattered showers and storms pushing them E/SE across
the area and eventually offshore.

&&

MARINE...Today-Tonight...Surface ridge axis remains south of the
area promoting a SWRLY flow generally 6-12 kts, though does increase
for a few hours mid/late evening to around 15 kts over the open
Atlc. The ECSB may not develop at all across the Volusia coast due
to the stronger westerly flow, but if it develops southward it will
likely remain pinned along the coast. Should it develop anywhere,
then naturally we will see winds back at the coast to ESE/SE. Expect
an increase in offshore pushing showers/storms as early as early
afternoon Cape northward with increasing chances southward late
afternoon/early evening. Winds/seas locally higher invof storms.
Seas mainly AOB 2 ft otherwise.

&&

.HYDROLOGY...The St Johns River Above Lake Harney near Geneva is
forecast to remain fairly steady at current levels, staying above
Action Stage and below flood stage through late this week and into
the weekend.

&&

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

Sedlock/Johnson

Hazardous Weather Outlook
National Weather Service Melbourne FL
1000 AM EDT Thu Jun 21 2018

AMZ550-552-555-570-572-575-FLZ041-044>047-053-054-058-059-064-141-
144-147-220300-
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-
1000 AM EDT Thu Jun 21 2018

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

.THUNDERSTORM IMPACT...
Scattered showers and storms will develop this afternoon through
early evening. Storm movement slowly east to southeast across
the region and offshore. A few stronger storms will be possible,
producing frequent lightning strikes, strong wind gusts up to 40
mph and locally heavy rainfall. Isolated locations may have brief
ponding of water on roadways or poor drainage flooding.

.MARINE THUNDERSTORM GUST IMPACT...
Scattered storms developing across the area, this afternoon and
early evening hours, will move slowly east to southeast. A few
stronger storms will have the potential to produce gusty winds
near 34 knots over inland lakes, and as they push offshore the
coast of east central Florida through late day.

.RIVER FLOOD IMPACT...
The St Johns River Above Lake Harney near Geneva is forecast to
remain fairly steady above Action Stage, but remaining below
flood stage through late this week and into the weekend.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
Moisture will remain elevated across the area through late week
and into the weekend, with scattered to numerous thunderstorm
development expected across east central Florida during the
afternoon and evening hours. A few stronger storms will continue
to be possible each day, producing frequent lightning strikes,
strong gusty winds and locally heavy rainfall.

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

Weitlich/Johnson

Special Weather Statement
National Weather Service Melbourne FL
1127 AM EDT THU JUN 21 2018

FLZ041-044>046-144-211630-
Northern Lake County FL-Orange FL-Seminole FL-Inland Volusia FL-
Southern Lake County FL-
1127 AM EDT THU JUN 21 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN SEMINOLE...LAKE...
WESTERN ORANGE AND CENTRAL VOLUSIA COUNTIES UNTIL 1230 PM EDT...

At 1126 AM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from near Emeralda to Mascotte. Movement was
east southeast at 10 mph.

Winds in excess of 40 mph will be possible with these storms.

Locations impacted include...
Deltona, Sanford, Apopka, Altamonte Springs and Ocoee.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2894 8194 2895 8166 2918 8162 2908 8115
      2835 8160 2835 8179 2836 8179 2836 8186
      2835 8186 2835 8194
TIME...MOT...LOC 1526Z 300DEG 6KT 2893 8178 2856 8189

Johnson