Alert archive / Florida / Areal Flood Advisories in 2021

Areal Flood Advisory 65, NWS Miami, FL

July 20, 2021Broward County, Palm Beach County, Florida

NWS Miami, FL issued this areal flood advisory at Jul 20, 2021, 12:45 PM EDT for Broward County, Palm Beach County, Florida. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Jul 20, 2021, 12:45 PM EDT (16:45 UTC)
Expired
Jul 20, 2021, 4:04 PM EDT
In force
3 hr
Issued by
NWS Miami, FL
Area
Storm-based polygon

Counties Broward County, FL, Palm Beach County, FL

The radar

The Miami radar (KAMX), 88 km from the middle of the area, began a volume at 16:44 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 4.8 hours before the alert went out and 66 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 12:00Z on 2021-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2142 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Miami, FL at 12:00Z on 2021-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
2142 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
757 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Miami, FL wrote its last area forecast discussion before this areal flood advisory went out at Jul 20, 9:59 AM EDT, 2 hours 46 minutes earlier.

Area forecast discussion, Jul 20, 9:59 AM EDT, 2 hours 46 minutes before
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Hazardous weather outlook, Jul 20, 9:52 AM EDT, 2 hours 53 minutes before
Hazardous Weather Outlook for South Florida
National Weather Service Miami FL
952 AM EDT Tue Jul 20 2021

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
210200-
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-
952 AM EDT Tue Jul 20 2021

...SCATTERED TO NUMEROUS STORMS THIS AFTERNOON...
...LOCALIZED FLOODING POSSIBLE WITH HEAVIEST DOWNPOURS...

This hazardous weather outlook is for South Florida.

.DAY ONE...TODAY AND TONIGHT

Thunderstorms: scattered to numerous thunderstorms, especially over
the east coast metro areas and Lake Okeechobee region. The primary
impacts will be lightning strikes, gusty winds, and locally heavy
rainfall.

Wind: A few storms could be strong enough to produce wind gusts up to
45mph.

Flooding: Localized flooding is possible with the heaviest
downpours, and instances of multiple rounds of heavy rain over the
same location.

Waterspouts: There is a slight chance of waterspouts over the
Atlantic waters this morning then over Lake Okeechobee and Gulf
waters this afternoon.

Temperature: Apparent temperatures will reach the slight to moderate
range, with possible values of 105 to 108 over much of the interior
this afternoon.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Scattered thunderstorms are possible each day, with the greatest
coverage expected over the western half of South Florida during the
afternoon hours. Heat indices are forecast to climb into the low 100s
as the week progresses.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

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

The office that day

Everything else NWS Miami, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 20, 1:51 PM EDTSpecial Weather StatementMFLPalm Beach39 min
Jul 20, 2:20 PM EDTSpecial Weather StatementMFLMiami-Dade40 min
Jul 20, 3:03 PM EDTSpecial Weather StatementMFLHendry42 min
Jul 20, 4:04 PM EDTFlash Flood WarningMFLBroward99 min
Jul 20, 4:37 PM EDTAreal Flood AdvisoryMFLBroward, Palm Beach66 min
Jul 20, 4:45 PM EDTSpecial Weather StatementMFLBroward45 min

Nearby

Areal Flood Advisories in Florida, 2021Every areal flood advisory in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.