Special Weather Statement, NWS Melbourne, FL

Area Forecast Discussion
National Weather Service Melbourne FL
239 PM EDT Thu May 6 2021

.DISCUSSION...

...Scattered Lightning Storms Developing This Afternoon; Isolated
Severe Possible...

Current-Tonight...Late morning, early afternoon start to convection
developing over the west central FL peninsula and moving rapidly
into central FL. Activity will traverse the peninsula and adjacent
local coastal waters presenting issues for mariners.

USAF 915 MHZ Cape wind profilers continue to show fairly deep
westerly flow. The ECSB will either be pinned along the coast or
only will make minimal inland progression this afternoon due to the
westerly flow aloft.

The 15Z KXMR sounding came in with a PWAT of 1.56 inches and a cool
500 mb temp of -9.0C. A frontal boundary is still forecast to press
southward into the central FL peninsula during the afternoon and
early evening. It will be preceded by SCT-NMRS showers and lightning
storms, especially across the eastern peninsula as the WCSB races
toward the east coast.

Sufficient parameters remain in place for a few strong/potentially
severe storms across ECFL, especially nearer the coast when activity
interacts with the ECSB, which will promote an increase in coverage
and intensity. Convection will continue to push east, or even
southeast propagating along outflow boundaries and eventually off of
the coast and across the local intracoastal/coastal waters. The best
chance for strong/isolated severe storms will between 3 pm and 7 pm.
One or two storms will be capable of damaging winds near 60 mph and
large hail. The SPC has kept for today the eastern peninsula in a
Marginal Risk for Severe Storms. Interactions with inland lake
breezes will also pose a risk for strong storms over the interior as
well. Frequent lightning strikes and localized heavy rainfall will
also be threats from showers and storms today. An isolated, short-
lived, tornado cannot be ruled out.

The storms will push offshore early this evening and the frontal
boundary will push south of Lake Okeechobee by sunrise Fri. Cooler
and drier air will gradually filter into the area behind the front
late, allowing min temps to fall back into the M-U60s most of the
area, except L60s for portions of north Lake/inland Volusia
counties, which is very close to seasonal norms for early May.

Previous Extended Forecast Discussion...

Friday-Sunday...The mid/upper level trough will move downstream of
east-central Florida as it follows the frontal boundary out of the
region. A slight chance for isolated showers will exist across the
Treasure Coast and areas near Lake Okeechobee with lingering
moisture possible behind the front through the morning hours. High
pressure will build in behind the front with cooler temperatures
expected as winds veer to the north-northwest areawide. Highs will
top out closer to normal with temperatures forecast to reach the mid-
to-upper 80s with mostly sunny skies and dry conditions. Lows will
reach the mid 50s to mid 60s overnight. The dry air will stick
around through the weekend across most of the County Warning Area
with high pressure parked over northern Florida and the associated
weak ridge over eastern CONUS. The warming trend will begin on
Sunday as winds switch from the south-southeast with the surface
high expected to move downstream of Florida; this means slightly
warmer highs can be expected on Sunday with temperatures in the
upper 80s to low 90s. Lows will also trend warmer with temperatures
in the 60s to low 70s overnight.

Sunday-Wednesday...Moisture will increase through Tuesday as
southeast flow continues with the surface ridge axis draping over
Florida. The return of significant moisture and WAA, will interact
with the seabreeze to create isolated to scattered showers and
thunderstorms daily mainly Monday through Wednesday. Temperatures
will warm up a bit heading into early next week, with highs in the
upper 80s to lower 90s and lows in the upper 60s to lower 70s Sunday
through Wednesday.

&&

.AVIATION...Onshore winds at the immediate coast with sea breeze
formation, although inland progression of the ECSB will be difficult
with the deep WRLY flow as previously mentioned. SCT SHRA/TSRA will
develop across the coverage warning area increase in coverage and
intensity as they move east and interact with the sea breeze which
will be located just inland from the coast during the late aftn. A
few strong storms will be capable of wind gusts up to 50 knots,
mainly near the east coast. Winds this evening/overnight generally
SW/W/WNW at 5-10 kts. Drying on Fri with NW/N winds in upwards of 15
kts and some higher gusts.

&&

.MARINE...Current-Tonight...The ECSB will be pinned along/near the
coast this afternoon due to stronger WRLY flow aloft. An early start
to showers/storms which will push off the coast all afternoon into
early evening. While winds over the open waters are forecast to
become a southerly component, any shower/storm development (pushing
off coast) will distort the local wind field (variability). Even
with 1-2 ft seas, both winds/seas locally higher invof of storms
later today/tonight.

Some of the storms will be strong, containing wind gusts up to 50
knots and possibly hail or isolated waterspout. The stronger storms
should clear the Treasure Coast by sunset or shortly thereafter. A
frontal boundary will push across the local Atlc waters late tonight
with winds becoming NW around 14-17 knots late in the night and
towards daybreak. This will build seas 3-4 feet offshore (Cape
northward).

Previous Marine Extended Forecast Discussion...

Friday-Monday... Winds will shift from the northwest Friday and
northeast by Friday evening through Saturday as high pressure builds
into Florida. Onshore flow will return by Saturday afternoon as the
high pressure ridge moves east into the Atlantic. Southeasterly flow
will be moderate Saturday night up to 15 knots and persist into
early next week with waves reaching 3-5ft in the offshore waters.
Winds will increase from the southeast at around 14-18kts on Monday
with waves of 2-4ft expected.

&&

.FIRE WEATHER...Fri...Minimum RH values reaching as low as 25-30pct,
northerly winds in upwards of 15 mph with some higher afternoon
gusts, and relatively high ERC values, will make for a fire weather
sensitive day across east-central Florida behind a cold front.

Sat...NERLY winds near 10 mph with min RH values 25-30pct NW of I-4
and 30-40pct Volusia coast and inland from the Space/Treasure
coasts. Continued fire sensitivity.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  64  84  58  80 /  10   0   0   0
MCO  68  85  59  84 /  20   0   0   0
MLB  68  84  62  82 /  30  10   0   0
VRB  68  85  61  83 /  40  10   0   0
LEE  66  84  57  84 /  10   0   0   0
SFB  66  85  58  83 /  20   0   0   0
ORL  69  86  61  85 /  20   0   0   0
FPR  67  86  61  83 /  40  10   0   0

&&

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

SHORT TERM...Sedlock
LONG TERM/RADAR....Weitlich
AVIATION...Sedlock
DATAC/BLOG...Haley

Hazardous Weather Outlook...Updated
National Weather Service Melbourne FL
317 PM EDT Thu May 6 2021

AMZ550-552-555-570-572-575-FLZ041-044>047-053-054-058-059-064-141-
144-147-070000-
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-
Northern Lake-Orange-Seminole-Southern Brevard-Osceola-
Indian River-Okeechobee-St. Lucie-Martin-Coastal Volusia-
Southern Lake-Northern Brevard-
317 PM EDT Thu May 6 2021

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL FLORIDA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

.THUNDERSTORM IMPACT...
Scattered lightning storms will continue south of the I-4 corridor
and move toward the East around 25 mph. Some of the storms will
become strong, especially as they collide with the east coast sea
breeze sitting just inland from the east coast during the mid to
late afternoon. The primary threats will be frequent lightning
strikes, strong wind gusts and very heavy rain. One or two storms
may become severe, containing damaging wind gusts near 60 mph and
large hail. An isolated, short-lived, tornado cannot be ruled out.
The best chance will be over the coastal counties between 3 pm and 7
pm. Locally heavy rainfall may cause brief, nuisance flooding in
prone spots.

.MARINE THUNDERSTORM GUST IMPACT...
Scattered lightning storms will continue over the Florida peninsula,
especially south of the I-4 corridor and move East around 25 mph
toward the east coast during the afternoon and early evening. As
these storms approach the Space and Treasure coasts, coverage and
intensity will increase before pushing across the intracoastal and
nearshore Atlantic waters. These offshore moving storms will be
capable of producing wind gusts greater than 35 knots along with
hail and very heavy rain. Special Marine Warnings are likely along
portions of the coast during the afternoon and early evening.

.WATERSPOUT IMPACT...
Storms near the coast late today may fully exploit the low level
shear resulting from boundary collisions. This may result in a
funnel cloud or two. Funnel clouds can briefly touch down,
producing a brief tornado or waterspout.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.
On Friday, the combination of low relative humidity and gusty
northwest winds will produce a fire weather danger. Any new or
ongoing fires may spread rapidly.

Isolated to scattered lightning storms will return early next
week.

.SPOTTER INFORMATION STATEMENT...
Spotters should monitor the weather and self activate if needed.

Sedlock/Kelly

PRELIMINARY LOCAL STORM REPORT
National Weather Service Melbourne FL
412 PM EDT THU MAY 6 2021

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

0356 PM     TSTM WND GST     MELBOURNE AIRPORT       28.10N 80.64W
05/06/2021  M39 MPH          BREVARD            FL   ASOS

            THE ASOS AT MELBOURNE INTERNATIONAL AIRPORT KMLB REPORTED
            A 39MPH/34KT WIND GUST FROM THE NNW

&&

CL

PRELIMINARY LOCAL STORM REPORT
National Weather Service Melbourne FL
414 PM EDT THU MAY 6 2021

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

0351 PM     TSTM WND GST     PATRICK AIR FORCE BASE  28.24N 80.61W
05/06/2021  M43 MPH          BREVARD            FL   AWOS

            THE AWOS AT PATRICK SPACE FORCE BASE KCOF REPORTED A
            43MPH/37KT WIND GUST FROM THE NW

&&

CL

PRELIMINARY LOCAL STORM REPORT
National Weather Service Melbourne FL
425 PM EDT THU MAY 6 2021

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

0412 PM     TSTM WND GST     VERO BEACH AIRPORT      27.65N 80.42W
05/06/2021  M40 MPH          INDIAN RIVER       FL   ASOS

            THE ASOS AT VERO BEACH MUNICIPAL AIRPORT KVRB REPORTED A
            40MPH/35KT WIND GUST FROM THE WSW

&&

CL

PRELIMINARY LOCAL STORM REPORT
National Weather Service Melbourne FL
504 PM EDT THU MAY 6 2021

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

0446 PM     TSTM WND GST     5 ESE BAREFOOT BAY      27.86N 80.44W
05/06/2021  M41 MPH          AMZ552             FL   C-MAN STATION

            STATION SIPF1 AT SEBASTIAN INLET REPORTED A 41MPH/36KT
            WIND GUST

&&

CL

PRELIMINARY LOCAL STORM REPORT
National Weather Service Melbourne FL
507 PM EDT THU MAY 6 2021

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

0432 PM     TSTM WND GST     3 ENE BAREFOOT BAY      27.90N 80.47W
05/06/2021  M39 MPH          Brevard            FL   MESONET

            WXFLOW STATION AT MELBOURNE BEACH BARRIER ISLAND
            SANCTUARY REPORTED A 39MPH/34KT WIND GUST

&&

CL

Special Weather Statement
National Weather Service Melbourne FL
558 PM EDT Thu May 6 2021

FLZ064-062245-
Martin FL-
558 PM EDT Thu May 6 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN MARTIN COUNTY UNTIL
645 PM EDT...

At 558 PM EDT, Doppler radar was tracking a strong thunderstorm near
Jonathan Dickinson State Park, or near Jupiter Island, moving east at
25 mph.

Half inch hail and wind gusts up to 50 mph will be possible with this
storm.

Locations impacted include...
Tequesta, Jupiter Island, Hobe Sound, Hobe Sound Beach and Jonathan
Dickinson State Park.

LAT...LON 2697 8008 2697 8014 2696 8014 2696 8026
      2708 8023 2707 8008
TIME...MOT...LOC 2158Z 281DEG 22KT 2698 8017

Pendergrast