Flash Flood and Heavy Rain in Florida, June 2, 2017

Area Forecast Discussion
National Weather Service Miami FL
806 AM EDT Fri Jun 2 2017

.AVIATION...
Numerous showers and at least a few thunderstorms are expected
today, likely leading to relatively brief, but significant
restrictions. Timing and duration confidence is too low to warrant
inclusion in TAFs, however. Coverage should increase through the
morning with most likely period for activity being early through
mid-afternoon. Went with SHRA with VCTS during this period. Winds
will generally be SE around 10 KT.

&&

.PREV DISCUSSION... /issued 418 AM EDT Fri Jun 2 2017/

DISCUSSION...
Latest water vapor imagery shows a plethora of mid
and upper level moisture stretching from the southern Gulf of
Mexico to the northeast, across the Florida peninsula. Meanwhile,
pockets of deep convection were noted near the Yucatan. Surface
analysis continues to indicate a 1020 mb surface high south of
Bermuda, which has once again allowed for a moist southeast flow.
Yesterday evenings 00Z MFL sounding measured 1.82 inches of PW,
much higher than 24 hours prior. With SBCAPE values near a
respectable 2500 J/KG, the atmosphere is primed for action.
However, besides a few hit and miss showers over the Atlantic, NWS
radar is rather quiet. Short term models prog this activity to
slowly approach the east coast metro by day break. With a light
southeast flow pattern expected today, both the Atlantic and Gulf
sea breezes will be allowed to develop. Lift from surface
convergence, along with diurnal heating, will generate scattered
to numerous showers and thunderstorms this afternoon. The highest
concentration of storms will again be over the central and
northern interior near Lake Okeechobee. However, outflow boundary
interactions could spread the activity all the way to the coasts
later in the day. The main threats from the activity will be brief
heavy rain from slow moving storms, and cloud to ground
lightning. Maximum temperatures will be lower than the last
several days, down the mid 80s along the coastal regions, due to
thickening cloud cover.

This weekend: Both the GFS and ECMWF continue to show influence
from a weak low pressure system centered over the southern Gulf
of Mexico. Out ahead of this feature, deep tropical moisture will
advect northeastward towards the Florida peninsula. The forecast
time- height cross sections shows moisture increasing at nearly
all levels from the surface to 300 mb with PWs periodically
creeping over 2 inches. Multiple shortwave disturbances associated
with the low will move over our CWA this weekend, further
enhancing instability and increasing the shower/storm coverage.
Greater mid and upper level cloud coverage will help to moderate
temperatures. Maximums may only reach the mid 80s across much of
the CWA on Saturday, around 5 degrees below average for this time
of year.

Early to mid next week: Long range guidance begins to deepen a
low pressure trough along the eastern seaboard early next week.
In response, winds will veer to the southwest, out ahead of this
feature. As abundant tropical moisture streams overhead, shower
and thunderstorm chances will remain elevated over our region
through at least mid next week.

MARINE...
Surface high pressure south of Bermuda will continue
to bring generally light southeast wind to the coastal waters
through this weekend. Shower and thunderstorm coverage will
likely increase today with a chance of showers and thunderstorms
through this weekend. Otherwise, generally good boating
conditions are expected with wave heights below 3 feet through
early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach  85  72  83  73 /  70  60  60  50
Fort Lauderdale  86  75  84  75 /  60  50  60  50
Miami            87  75  84  74 /  60  50  60  50
Naples           87  73  84  73 /  60  50  50  50

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&

DISCUSSION...27/JT
MARINE...27/JT
AVIATION...23/SK

Hazardous Weather Outlook for South Florida
National Weather Service Miami FL
937 AM EDT Fri Jun 2 2017

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
030145-
Lake Okeechobee-Biscayne Bay-
Coastal waters from Jupiter Inlet to Deerfield Beach FL out 20 NM-
Coastal waters from Deerfield Beach to Ocean Reef FL out 20 NM-
Waters from Jupiter Inlet to Deerfield Beach FL from 20 to 60 NM-
Waters from Deerfield Beach to Ocean Reef FL from 20 to 60 NM
excluding the territorial waters of Bahamas-Glades-Hendry-
Inland Palm Beach-Metro Palm Beach-Coastal Collier-Inland Collier-
Inland Broward-Metro Broward-Inland Miami-Dade-Metro Miami-Dade-
Mainland Monroe-Coastal Palm Beach-Coastal Broward-Coastal Miami-
Dade-Far South Miami-Dade-
Coastal waters from Chokoloskee to Bonita Beach FL out 20 NM-
Coastal waters from East Cape Sable to Chokoloskee FL out 20 NM-
Waters from Chokoloskee to Bonita Beach FL from 20 to 60 NM-
937 AM EDT Fri Jun 2 2017

...Thunderstorms with heavy rainfall possible, especially
afternoon...
...Moderate Risk of Flooding in Northeastern Miami-Dade County...

This hazardous weather outlook is for South Florida.

.DAY ONE...TODAY AND TONIGHT

Thunderstorms: Thunderstorms are possible across South Florida,
mainly this afternoon. The best chances will be in the interior once
again. The main threats will be lightning and locally heavy rain,
which may produce some urban street flooding, mainly in Collier
County.

Waterspouts: There is a slight chance of waterspouts across the South
Florida coastal waters, mainly in the morning hours.

Flooding: There is a moderate risk of flooding in Miami-Dade county
with some heavy rainfall associated with convective showers and
thunderstorms this morning and afternoon. There also is a slight risk
flooding over urban areas in Collier County and Lake Okeechobee
region later this afternoon with storms and showers.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

Thunderstorms will continue to be possible for all areas through
Saturday, mainly during the afternoon. The primary threat with this
activity will be lightning, gusty wind, and locally heavy rainfall.

No other Hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

For more information...visit the National Weather Service in
Miami website at www.weather.gov/miami.