MIAMI-SOUTH FLORIDA National Weather Service Forecast Office http://www.weather.gov/miami National Weather Service Preliminary Report August 1, 2017 Miami and Miami Beach Flood Event Synopsis: an elongated area of low pressure (trough) extended across South Florida on August 1st. This along with daytime heating triggered a band of heavy showers and thunderstorms just off the coast of Miami-Dade County early in the afternoon. This band then redeveloped to the west over Miami Beach, Key Biscayne and Downtown Miami just after 2 PM and became nearly stationary, then redeveloped farther to the west and southwest across The Redland, Kendall, Palmetto Bay and Pinecrest. Rainfall totals of 4-6 inches were widespread in these areas, with isolated amounts of 7-8 inches. Virtually all of this rain fell in a three-hour period during the mid and late afternoon ending around 6 PM. Rainfall rates of 2-4” per hour were common, with these rates generally lasting for 2-3 hours. This in combination with high tide between 5-6 PM led to significant flooding in the Miami Beach and Brickell areas. Impacts (information gathered from a combination of sources including TV and print media, social media and survey by NWS meteorologists): - Miami Beach: numerous reports of flood waters entering businesses, homes, apartment lobbies and parking garages. Water was 1 to 2 feet deep on streets in many areas of South Beach, including Purdy Avenue, West Avenue, Alton Road, Pennsylvania Avenue, Meridian Avenue, Collins Avenue, Washington Avenue and Indian Creek Drive. Numerous vehicles stalled in these streets and others across the city. - City of Miami: more than 10 businesses, stores and buildings in the vicinity of Mary Brickell Village had at least 1 to 4 inches of water inside their structures, based on water marks and accounts from store employees. This includes stores and businesses on SW 10th Street between S. Miami Avenue and SW 1st Avenue. SW 10th street was also closed for half a block due to deep water. - Rest of Miami-Dade County: no major impacts noted other than flooded neighborhood streets. (note: this weather event was not directly associated with Tropical Storm Emily, but as part of the trough which extended across South Florida. This is the same trough that spawned Emily early Monday morning July 31st in the northeastern Gulf of Mexico, which moved south to across South Florida by Tuesday, August 1st.) Select 24-hour Rainfall Totals ending at 8 AM Wednesday, August 2nd (data below considered unofficial except Miami Beach Golf Club) The Redland/Krome Ave & SW 200 Street (CoCoRaHS) 7.46” Miami Beach/Alton Road & 56th Street (CWOP) 7.19” Miami Beach Golf Club (NWS COOP) 6.50” Virginia Key (Miami-Dade DTPW) 5.25” Virginia Key/NOAA-AOML (CoCoRaHS) 5.18” Florida’s Turnpike & SW 173rd Street (CWOP) 4.72” Palmetto Bay (CoCoRaHS) 4.44” Pinecrest/The Falls 4.03” Kendall/SW 136th Street & 127th Ave (Wunderground) 3.84” Virginia Key: Univ. of Miami RSMAS 3.74” Brickell Key (Miami-Dade DTPW) 3.68 Vizcaya Area (WeatherBug) 3.41” Miami/SW 25th Street & 27th Avenue (Wunderground) 3.33” Surfside (CWOP) 3.31” Pinecrest/SW 102nd Street and US1 (Wunderground) 3.19” Marlins Park (WeatherBug) 2.61” Note on graphics below: radar estimates can be significantly far off from actual measurements. Rain gauges are considered “ground truth” and are typically more accurate than radar estimates. The graphics below are storm total rainfall estimates from the Key West WSR 88-D radar. The Miami WSR 88-D radar graphic is not included as it did not have a good handle on the rainfall totals for most areas and was biased too low. The graphics of radar totals help us to graphically see the general areas where the heaviest rains occurred. For estimating rainfall totals, we use the rain gauge data, and then fill in the gaps with the radar data to provide estimates of rainfall totals. 24-hour rain graphic from NWS Key West WSR 88-D Radar with select rain gauge measurements included 24-hour rain total graphic from NWS Weather and Hazards Data Viewer Acknowledgments: Andrew Hagen of NWS Miami contributed greatly to this report by compiling the rainfall data and creating the graphics, as well as conducting an informal flood survey in the Brickell area yesterday evening. .