A tropical tropospheric trough (TUTT) moving northwest across the area along with a surface trough across the Florida peninsula allowed for scattered showers and storms to develop across the Atlantic waters and Biscayne Bay. 5 inches.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MFL wrote it up.
A tropical tropospheric trough (TUTT) moving northwest across the area along with a surface trough across the Florida peninsula allowed for scattered showers and storms to develop across the Atlantic waters and Biscayne Bay. Deep moisture and plenty of instability resided across the region as well, with PW's close to 2.5 inches. The overall flow regime was light and a little more southeasterly to southerly. Therefore, another day of increased diurnal coverage of showers and thunderstorms on top of already saturated soils with slow storm motion and high rainfall rates led to flooding across portions of Miami-Dade and Collier counties.
The local office's own words before the first event, 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 the first event at Sep 9, 6:30 AM EST, 2 hours earlier.
Area Forecast Discussion National Weather Service Miami FL 730 AM EDT Wed Sep 9 2020 .Aviation... Unsettled pattern continues with morning showers and storms around the waters which could sneak near a terminal causing bouts of sub- VFR. Convective focus will shift over land as the morning continues with the highest coverage of showers and storms expected inland this afternoon. Sub-VFR conditions will continue to be possible through the period with any convection with IFR/LIFR possible at terminals directly impacted. && .Prev Discussion... /issued 240 AM EDT Wed Sep 9 2020/ DISCUSSION... Short Term (Today-Thursday): Showers and storms have continued over the local waters of South Florida overnight, particularly in the Gulf near and SW Florida coast. The tropical tropospheric trough (TUTT) is moving northwest across the area. With the latest TAFB surface analysis has a surface trough SW-NE across the Florida peninsula. Also, latest satellite derived precipitable water values are above 2 inches and the 00Z MFL sounding had a value of ~2.2 inches. Deep moisture and plenty of instability remains across the region today. The overall flow regime will remain light and become a little more southeasterly to southerly. Therefore, another day of increased diurnal coverage of showers and thunderstorms with slow storm motion, potential training of storms and high rainfall rates. The main concern remains unchanged from yesterday with heavy rainfall and the potential for flooding. We will have to monitor localized areas that may see heavy rainfall with repeated rounds on top of any already saturated soils. Flash Flood guidance is about 3 to 3.5 inches in a 3 hour timeframe across portions of the east coast, while flash flooding is not the most likely scenario there is low-end potential for this over vulnerable, low-lying areas with antecedent conditions. Overall, increased coverage of showers and thunderstorms with Lake region and western Atlantic metro seeing the highest rain chances this afternoon and evening. As we move into Thursday, easterly flow returns with the abundant moisture still across the area. However, the more typical summertime pattern of late morning-early afternoon showers and storms along the east coast before shifting towards the interior and Gulf coast as the sea breeze and easterly flow push. Increased cloud cover will once again keep temperatures near to just below normal for this time of year. Long Term (Thursday night - Tuesday): Model guidance for the long term begins the period with broad high pressure expanding across the western Atlantic, while a meandering semi-stationary frontal boundary slides gradually into northern Florida. This boundary will help in keeping deep moisture over SoFlo through the upcoming weekend, while the southern periphery of the aforementioned high will bring persisting ESE flow across the area through much of the long term. This synoptic scenario will result in continuing moisture advection, with passing showers and thunderstorms favoring the afternoon/early hours each day. Model POPs remain fairly high, with long range solutions showing values as high as 90 percent all the way to the weekend. But the continuing variance between model runs in the past couple of days suggest that inherited philosophy of capping POPs around 70 percent is reasonable. Thus, will continue to cap at 70 percent each afternoon period through Sunday. POPs begin to gradually decrease on Monday with a little drier air filtering into the region. Models also develop an amplifying trough over the central CONUS and migrate it eastward during the weekend, pushing the ridge over the west Atlantic slightly southward and closer to the Florida peninsula. But the trough seems to remain well north of the area with no significant impacts in our overall weather scenario. Thus, expect the easterly flow/sea breeze weather pattern to continue. For temperatures, the hot days continue with afternoon highs still hovering the low 90s, and heat index values in triple digits for most of SoFlo. MARINE... Fairly benign marine conditions outside of showers and thunderstorms across all the local waters through the period at times. Lightning, waterspouts, and locally higher winds and waves will be concerns with the strongest storms impacting any portions of the waters. && .Preliminary Point Temps/PoPs... West Palm Beach 89 76 89 77 / 40 30 50 20 Fort Lauderdale 89 78 88 79 / 50 30 60 30 Miami 90 78 90 78 / 50 40 60 30 Naples 90 75 91 76 / 50 50 80 40 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && Aviation...02/RAG
Hazardous Weather Outlook for South Florida National Weather Service Miami FL 310 AM EDT Wed Sep 9 2020 AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676- 091915- 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- 310 AM EDT Wed Sep 9 2020 ...SHOWERS/STORMS ACROSS SOUTH FLORIDA TODAY... ...LOCALIZED FLOODING POSSIBLE DUE TO HEAVY RAINFALL... This hazardous weather outlook is for South Florida. .DAY ONE...TODAY AND TONIGHT Thunderstorms: Scattered to numerous thunderstorms this afternoon and evening. Main concerns are the potential for heavy rainfall resulting in localized street flooding, and lightning. Waterspouts: Isolated waterspouts are possible over all local South Florida waters. Flooding: This is the main concern with showers and thunderstorms today. High rainfall rates and multiple rounds of heavy rainfall may lead to localized flooding. No other hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY Thunderstorm chances remain elevated through the week. The primary concerns are heavy rain along with lightning and to a lesser degree strong gusty winds. Rip current risk could increase by late this upcoming weekend particularly across the Palm Beach beaches. No other hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... Spotter activation is not anticipated. However, please relay any information about observed severe weather to the NWS while following all local, state, and CDC guidelines. For more information...visit the National Weather Service in Miami website at www.weather.gov/miami.
The national radar mosaic for the moment the first event began.
3 flood. Local standard time, as filed.
A member of the public reported via social media flooding produced by heavy rains from a thunderstorm near NW 36th Street and 24th Avenue with water half way up car tires.
Broadcast media reported several streets in Hollywood that flooded with several cars stalled out in the flood waters near Moffett Street and 14th Avenue due to heavy showers and thunderstorms. Rainfall amounts from gauges in the area were around 3.5 inches between 9 AM and 1030 AM EDT.
Social media reported significant flooding on Isle of Capri and surrounding areas with water three-quarters the way up a fire hydrant and halfway up a mailbox. Personal rain gauge in Isle of Capri and Marco Island measured 3 to 4.5 inches between 11 AM and 12:30 PM EDT.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2020Every state in 2020This day in weather historyWarnings in Florida, September 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 920156, 920157, 920158.