Small Craft Advisory for Winds 4, NWS Melbourne, FL

East Central Florida Forecast Discussion
National Weather Service Melbourne FL
917 AM EDT Thu May 4 2017

...A Few Strong Storms Possible this Afternoon into Friday...

.DISCUSSION...
The local environment will destabilize somewhat during the remainder
of the day due to a combination of surface heating, approach of an
upr disturbance, along with development of breeze boundaries and
cooling aloft. These favorable factors will be offset by a canopy of
higher clouds encroaching from the west along with late timing of
the approaching gulf convection toward the FL west coast.

HRRR, which usually has good performance with effects from upstream
organized convection, is not too keen on development of interior
convection over ECFL before 00Z, and they are indicating some sct
storm potential near the east cst ascd with an inland moving ECSB
boundary.  The current forecast wl continue to indicate this along
with a few strong storms: containing small hail and convective wind
gusts of 40 to 50 mph and frequent lightning.

...From previous disc...

There will be an initial chance for storms this afternoon as sea
breeze convection forms well ahead of the approaching front. The
HRRR model has been showing both east and west coast sea breezes
becoming active, and boundary collisions over the east side of the
peninsula generating scattered storms which move offshore around
or a little after sunset. That model was also showing a decaying
pre frontal band of convection or remnant outflow boundary
reaching the area and possibly adding to low level convergence.
Even absent that added bit of forcing, the east coast sea breeze
will provide backed low level winds which may allow for some storm
organization near the coast, but the severe threat looks marginal.

Band of pre-frontal moisture will then spread across the area in the
late evening and overnight.  The HRRR shows decaying band of pre
frontal showers occurring during the evening.  The question then
becomes whether the air mass will recover enough for convection to
redevelop down into the Gulf of Mexico ahead of advancing front.

Deep layer shear will be increasing and low level flow should
stay backed to the south, indicating sufficient convergence for a
line of convection that moves inland from the Gulf to hold
together. With the trough aloft digging well down into the Gulf,
large scale lift also looks supportive of convection. Low level
shear will not be as strong as our typical cool season systems,
but it's May and it should be easier to maintain some cape
overnight. Will just mention that a few storms overnight could be
strong in the Hazardous Weather Outlook for now.

MOS POPs increased on the 00z run and the HRRR has been generating
scattered coverage, so bumped values to 40 percent except 50 percent
in the north this afternoon.  Little change with POPs tonight,
likely in the north and chance in the south.

&&

.AVIATION...Scattered showers and storms will form on the east and
west coast sea breezes this afternoon.  They will bring local MVFR-
IFR for a brief time.  A few of the storms could generate strong
wind gusts.  This activity will move offshore around 00z.  There
will be an additional chance of showers and storms during the
overnight ahead of an approaching frontal boundary.

&&

.MARINE...
Today-Tonight...Winds will become more southerly and pick up to 10-
15 knots this afternoon, except 15-20 knots in the northern waters,
as a frontal boundary approaches. Winds overnight will generally be
south/southwest 15-20 knots. Isolated to scattered storms are
expected to push offshore late this afternoon and early evening.
There is also a chance for another round of showers and storms late
tonight as the front enters the northern waters.

&&

.FIRE WEATHER...
A southerly wind flow will increase low level moisture today, so
min RH values are forecast above 40 percent. A high coverage of
showers and lightning storms will move across east central FL
tonight/Friday bringing a wetting rain to some areas. Dispersion
will be very good Fri with transport winds from WSW around 20
knots by afternoon and stronger in the morning. Dry weather is
expected Saturday into next week with critically low RH possible
across the interior Sunday and Monday.

&&

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

&&

JP/DKW

Hazardous Weather Outlook...UPDATED
National Weather Service Melbourne FL
959 AM EDT Thu May 4 2017

AMZ550-552-555-570-572-575-FLZ041-044>047-053-054-058-059-064-141-
144-147-050000-
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-
959 AM EDT Thu May 4 2017

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

.THUNDERSTORM IMPACT...
Moisture will increase today as a frontal boundary approaches.
There will be a chance of storms this afternoon along the east and
west coast sea breeze boundaries. A few of these storms could
become strong, especially near the east coast later this
afternoon and into the early evening as they move east to
northeast up to 20 to 30 mph and offshore.

A band of showers and storms currently pushing eastward over the
eastern Gulf of Mexico may weaken as they approach the west coast
of Florida later today. However, there is potential for a few
stronger storms with any redeveloping convection ahead of the
weak cold front as it moves into the area late this evening and
overnight, mainly across Lake County and toward the I-4 corridor.

Any stronger storms this afternoon and into tonight will have the
potential to produce strong wind gusts around 40 to 50 mph, small
hail, frequent lightning strikes and locally heavy rainfall.

.MARINE THUNDERSTORM GUST IMPACT...
Scattered storms that form over land will move northeast 20 to 25
knots and cross the coast late this afternoon and into the
evening, potentially evolving into a line of storms that moves
well offshore. Mariners can expect special marine warnings for
wind gusts 35 to 40 knots, even in the waters more than 20
nautical miles offshore.

.WIND AND SEA IMPACT...
South winds will increase to 15 to 20 knots across the waters
north of Cape Canaveral this afternoon, and across most of the
coastal waters tonight.  Small craft should exercise caution.

.FIRE WEATHER IMPACT...
The air mass will be more moist than yesterday, but dry vegetation
combined with a potential for lightning strikes and gusty winds
from storm outflow boundaries, could pose a moderate to high
danger for wildfire spread.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
Scattered showers and storms are forecast along and ahead of a
frontal boundary that will settle southeast of the area Friday
afternoon. Some could be strong, especially south of Orlando and
Cape Canaveral to the Treasure Coast and Okeechobee. Marine
conditions are forecast to remain poor to marginally hazardous
behind the front into Saturday, especially offshore.

.SPOTTER INFORMATION STATEMENT...
Spotters are requested to monitor the weather and self activate
if needed.

Lascody/Weitlich