Flood in Florida, November 19, 2021

Area Forecast Discussion
National Weather Service Miami FL
932 AM EST Fri Nov 19 2021

.UPDATE...
Breaks in dense cloud coverage have allowed for sunshine to grace
parts of the east coast today, allowing for temperatures 1-2
degrees above forecast guidance. The 12Z MFL sounding indicates
bifurcated steering flow, as modest westerly mid/upper
tropospheric flow sits atop moist boundary layer (SFC-850 hPa)
easterly winds. These competing steering currents are allowing for
a slow meandering of convection towards the SSW. Furthermore, PWI
nearing 2.0 inches and mean LFC (level of free convection) of
around 1 to 1.5 km indicates that deep moist convection should
initiate with little encumbrance. Of particular concern for today
are recently saturated locations (including near downtown Miami).
Enhanced instability and weak mean steering flow could result in
high rainfall rates and slow moving storms - a favorable setup for
potential localized and flash flooding. Greatest rainfall
potential for today generally exists from the early afternoon to
early evening hours, though showers may linger periodically
thereafter.

&&

.PREV DISCUSSION... (Issued 642 AM EST Fri Nov 19 2021)

AVIATION(12Z TAFS)...
Active convection this morning along the Atlantic terminals, as
intermittent MVFR conditions are possible owing to reductions in
CIGs/VIS. Greatest convective coverage and associated impacts
likely between 15-00Z. Short-fused TEMPO groups could be necessary
to account for brief IFR/LIFR impacts. Convective coverage should
generally wane around 00Z, though lingering SHRA/TSRA will remain
possible overnight. Winds generally NE around 10 kt.

PREV DISCUSSION... (Issued 242 AM EST Fri Nov 19 2021)

SHORT TERM (Friday and Saturday)...

The deep tropical moisture will remain over South Florida today and
into the weekend. A sfc trough just offshore between South Florida
and the Bahamas as well as a cold front moving down the peninsula
today stalling and washing out. A mid-level impulse will also move
over the Florida peninsula helping enhance convection. Hi-res models
develop convection over the waters and coastal areas which then push
west over east coast given the northeast flow pattern. High rain
chances will be along the east coast today. Scattered to numerous
showers and thunderstorms possible with the main impact being heavy
rainfall leading to localized flooding. Storm will have high
rainfall rates and the potential for training storms could drop a
few inches of rain in a short amount of time. Flooding potential
will be higher over areas that saw a significant amount of rainfall
yesterday.

The unsettled weather pattern will continue into the weekend. Deep
moisture with the front washing out across the area and surface
trough over the east coast or just offshore will continue to allow
for showers and storms each afternoon and evening. The highest
chance of POPs will be over the east coast metro areas. The PWAT
values will also remain high over the eastern areas of South Florida
this weekend around 1.7 to 1.9 inches which is near the 90th
percentile range for this time of year. Therefore, the main concern
will continue to be the potential for heavy rainfall and localized
flooding. With areas with antecedent conditions due to previous days
rainfall having higher potential of flooding concerns.

Given the antecedent conditions and the potential for heavy
rainfall, high rainfall rates and training of storms leading to
localized flooding. The Weather Prediction Center has placed the
east coast of South Florida in a Marginal Risk for excessive
rainfall both Friday and Saturday.

LONG TERM (Saturday Night through Thursday)...

With the southern stream tangled in the departing northern stream
wave, an elongated area of +PV will overspread south Florida on
Sunday resulting in a swath of dry air in the middle and upper
troposphere. However, in the lower atmosphere, easterly flow
around the base of a ridge will advect Atlantic moisture into
south Florida beneath the aforementioned dry air. This regime will
favor late night convection over the Gulf stream, spreading
inland through the mid-morning hours and gradually dissipating
across the interior/west coast later in the day. Sunday night into
Monday, a northern stream frontal system will move into the
eastern CONUS and push the surface ridge eastward. As it does so,
low-level flow will veer southwesterly ahead of the surface front.
This will essentially cut off any upslope flow or moisture
transport into the region and begin the drying process. The veered
flow will also limit convergence along the approaching frontal
boundary, and with the continued presence of dry air aloft, little
in the way of showers and storms are expected along the front
Monday into Monday night. The remainder of the week looks to
remain dry in the wake of the frontal passage and with deep layer
ridging forecast thereafter.

At the core of the frontal system, it's forecast to have anywhere
between -2 to -3 sigma height and temperature anomalies. The cold
core will be nearest to south Florida on Tuesday, and with flow
originating from a solely continental source, highs will struggle
to reach the 70 degree mark along the east coast metros and will
likely remain in the middle to upper 60s elsewhere. Overnight
Tuesday, lows are forecast to fall into middle to upper 40s across
the interior Lake region, upper 40s to low 50s across the
remainder of the interior, and the mid to upper 50s across the
southeast portions of south Florida. Beyond Tuesday, a gradual
warming trend is expected as ridging slowly overspreads and low-
level flow veers easterly.

MARINE...

Breezy northeast to easterly flow over the local South Florida
waters. Pressure gradient tightens to allow for Small Craft
Advisory later today and overnight for the Atlantic waters and
northern Gulf waters. An increasing northeasterly swell will
increase seas in the northern Atlantic waters so the Small Craft
Advisory will continue for the northern Atlantic into the weekend.
Scattered to numerous shower and thunderstorm chances will
continue over all waters today, and will continue through the
weekend for the Atlantic waters.

BEACHES...

East/northeasterly flow continues across the region. This will
allow for a high risk of rip currents for the Atlantic beaches
through at least Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            73  80  73  82 /  50  70  40  30
West Kendall     72  82  71  83 /  50  70  40  30
Opa-Locka        72  81  72  83 /  50  70  50  30
Homestead        72  80  71  82 /  50  60  40  30
Fort Lauderdale  73  80  74  81 /  50  70  50  40
N Ft Lauderdale  73  80  73  81 /  50  70  50  40
Pembroke Pines   72  80  71  82 /  50  70  50  30
West Palm Beach  72  80  71  81 /  50  70  50  40
Boca Raton       73  80  72  82 /  50  70  50  40
Naples           69  83  68  83 /  20  30  10  30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Saturday evening for FLZ168-172-
     173.

AM...Small Craft Advisory from 4 PM this afternoon to 10 AM EST
     Saturday for AMZ651-671.

     Small Craft Advisory from 4 PM this afternoon to 4 AM EST Sunday
     for AMZ650-670.

GM...Small Craft Advisory from 4 PM this afternoon to 10 AM EST
     Saturday for GMZ656-676.

&&

Update/Aviation...Bhatti

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Hazardous Weather Outlook for South Florida
National Weather Service Miami FL
1044 AM EST Fri Nov 19 2021

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
200945-
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-
1044 AM EST Fri Nov 19 2021

...Localized Flooding Possible East Coast...
...Hazardous Marine And Beach Conditions...

This hazardous weather outlook is for South Florida.

.DAY ONE...TODAY AND TONIGHT

Flooding: High rainfall rates and slow moving storms may lead to
localized flooding across portions of the east coast metropolitan
areas.

Thunderstorms: Scattered to numerous showers and thunderstorms will
be possible today across South Florida. Main impacts will be localized
flooding and lightning.

Rip currents: There is a high risk of rip currents for all Atlantic
beaches.

Waterspouts: A waterspout threat exists for all of the local waters
through at least this evening (with the exception of the outer Gulf
waters).

Marine: Increasing northeasterly winds around 15-20 knots with
higher gusts may cause hazardous marine conditions. A small craft
advisory will go into effect this afternoon and continue into the
weekend for South Florida waters.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

An elevated risk of rip currents will continue along the Atlantic
beaches throughout the rest of the week and may linger into the
upcoming weekend. Rip Current risk for the Gulf waters will increase
with a frontal passage early next week.

There is potential for heavy rainfall on Saturday as well, which
could lead to localized flooding. The greatest risk will be for
recently saturated locations along the east coast.

Elevated winds and seas will result in hazardous marine conditions
for small craft operators into the upcoming weekend.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated, however individual spotters
are encouraged to report flooding to the National Weather Service
forecast office in Miami.

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

PRELIMINARY LOCAL STORM REPORT...SUMMARY
NATIONAL WEATHER SERVICE MIAMI FL
643 AM EST FRI NOV 19 2021

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

0524 PM     FLOOD            2 NNE MIAMI             25.79N 80.19W
11/18/2021                   MIAMI-DADE         FL   BROADCAST MEDIA

            WTVJ METEOROLOGIST REPORTED STREET FLOODING
            IN DOWNTOWN MIAMI VIA SOCIAL MEDIA NEAR THE
            CORNER OF BISCAYNE BLVD AND NE 15TH ST.
            WATER WAS ABOUT HALFWAY UP THE TIRES OF
            CARS.

0538 PM     FLASH FLOOD      1 NE MIAMI              25.78N 80.19W
11/18/2021                   MIAMI-DADE         FL   PUBLIC

            PUBLIC REPORTED FLOODING OF ROADWAYS NEAR
            THE FROST SCIENCE MUSEUM IN DOWNTOWN MIAMI
            INCLUDING STALLED CARS IN THE FLOOD WATERS.

0541 PM     FLASH FLOOD      1 NNE MIAMI             25.79N 80.19W
11/18/2021                   MIAMI-DADE         FL   BROADCAST MEDIA

            WSVN REPORTED SEVERAL VEHICLES STRANDED IN
            FLOOD WATERS ALONG BISCAYNE BLVD NEAR THE
            ADRIENNE ARSHT CENTER VIA SOCIAL MEDIA.

0559 PM     FLOOD            1 SE LIBERTY CITY       25.81N 80.21W
11/18/2021                   MIAMI-DADE         FL   PUBLIC

            PUBLIC REPORTED FLOODING VIA SOCIAL MEDIA ON
            INTERSTATE 195 NEAR THE INTERSTATE 95
            INTERCHANGE BLOCKING THE FAR RIGHT EASTBOUND
            LANE OF TRAFFIC.

0613 PM     FLOOD            2 SSW MIAMI BEACH       25.78N 80.14W
11/18/2021                   MIAMI-DADE         FL   PUBLIC

            PUBLIC REPORTED FLOODING VIA SOCIAL MEDIA
            NEAR THE INTERSECTION OF ALTON ROAD AND 10TH
            STREET. SEVERAL INCHES OF STANDING WATER
            WERE VISIBLE OVER THE CURB, SIDEWALK, AND
            PART OF THE ROADWAY. WATER WAS ROUGHLY ABOUT
            HALFWAY UP THE TIRES OF CARS.

0616 PM     FLOOD            MIAMI BEACH             25.81N 80.12W
11/18/2021                   MIAMI-DADE         FL   PUBLIC

            PUBLIC REPORTED FLOODING VIA SOCIAL MEDIA AT
            THE INTERSECTION OF COLLINS AVE & 36TH ST IN
            MIAMI BEACH. SEVERAL INCHES OF WATER WERE
            VISIBLE ABOVE THE ROADWAY AND ADJACENT
            SIDEWALK. WATER WAS ABOUT HALFWAY UP THE
            TIRES OF CARS.

0626 PM     FLASH FLOOD      MIAMI BEACH             25.81N 80.12W
11/18/2021                   MIAMI-DADE         FL   PUBLIC

            PUBLIC REPORTED FLASH FLOODING VIA SOCIAL
            MEDIA AT THE INTERSECTION OF 34TH STREET AND
            COLLINS AVENUE. SOCIAL MEDIA PICTURE
            PROVIDED SHOWS WATER ENTERING A BUILDING.

0629 PM     FLASH FLOOD      1 NNE MIAMI             25.78N 80.19W
11/18/2021                   MIAMI-DADE         FL   BROADCAST MEDIA

            BROADCAST METEOROLOGIST REPORTS FLASH FLOOD
            VIA SOCIAL MEDIA AT THE INTERSECTION OF
            BISCAYNE BLVD & NE 11TH ST IN DOWNTOWN
            MIAMI. SEVERAL STALLED-OUT VEHICLES ARE
            PRESENT IN THE PHOTO PROVIDED, WITH WATER
            COMPLETELY OBSCURING CAR TIRES. CURBS AND AN
            ADJACENT SIDEWALK TO THE ROADWAY ARE NO
            LONGER VISIBLE.

0643 PM     FLASH FLOOD      3 SSW MIAMI BEACH       25.77N 80.14W
11/18/2021                   MIAMI-DADE         FL   BROADCAST MEDIA

            BROADCAST REPORTER POSTED A VIDEO ON SOCIAL
            MEDIA SHOWING SEVERAL INCHES OF STANDING
            WATER ON 5TH STREET IN THE VICINITY OF
            MICHIGAN AVE. WATER APPEARED TO BE MORE THAN
            HALFWAY UP CAR TIRES WITH ADJACENT SIDEWALKS
            AND CURBS COMPLETELY UNDER WATER.

&&

ATV