Flash Flooding and Debris Flows in Puerto Rico, November 7 to 12, 2020

Name: Flash Flooding and Debris Flows in Puerto Rico, November 7 to 12, 2020
Start: 2020-11-07T15:00
End: 2020-11-12T02:45
Location: Puerto Rico

November 7 to 12, 2020 · NWS SJU · 26 events in 11 counties and zones

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 26

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.

What happened

The episode as NWS SJU wrote it up.

Very deep tropical moisture pulled up by the circulation of Tropical Cyclone Eta as it was moving across Cuba and into Southern Florida moved over the area. As a result, environmental conditions were very favorable for multiple days of heavy shower activity. A tropical wave was also injected into Eta's moisture plume, further enhancing the moisture content across the local area between 11/10 and 11/11.

What forecasters said that day

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 San Juan, PR wrote its last area forecast discussion before the first event at Nov 7, 11:57 AM AST, 3 hours 3 minutes earlier.

Area forecast discussion, Nov 7, 11:57 AM AST, 3 hours 3 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, Nov 7, 5:28 AM AST, 9 hours 32 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The radar

The San Juan radar (TJUA), 108 km away, was scanning. The volume nearest the first event began at 18:57 UTC.

Open the radar archive at this moment

Event by event

12 flash flood, 10 flood, 4 debris flow. Local standard time, as filed.

Flood, Isabela

When: November 7, 3:00 PM AST to 5:45 PM AST
Where: Isabela County, 28.16 mi NW of Adjuntas to 27.98 mi NW of Adjuntas
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.483, -67.025

Flooding was reported along Calle Malasia between Road PR-4470 and Road Kuwait.

Flood, Guayama

When: November 8, 12:26 PM AST to 8:49 PM AST
Where: Guayama County, 1.86 mi NNE of Guayama to 1.8 mi NNE of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.003, -66.115

Urban flooding on Road PR-179 KM 0.8.

Flash Flood, Humacao

When: November 8, 3:30 PM AST to 9:30 PM AST
Where: Humacao County, 4.07 mi NNW of Humacao to 3.45 mi N of Humacao
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.187, -65.817

The intersection of Roads PR-927 and PR-924 was closed to traffic due to flooding.

Flood, Guayama

When: November 8, 4:00 PM AST to 8:49 PM AST
Where: Guayama County, 2.95 mi WSW of Guayama to 3.06 mi WSW of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.961, -66.171

Flooding was reported on Road PR-3, near Alpla factory in that area.

Flood, Guayama

When: November 8, 4:00 PM AST to 8:49 PM AST
Where: Guayama County, 0.44 mi E of Guayama to 0.52 mi NE of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.981, -66.123

Avenida Laporte was flooded.

Flood, Guayama

When: November 8, 4:15 PM AST to 8:49 PM AST
Where: Guayama County, 0.32 mi NE of Guayama to 0.38 mi NE of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.983, -66.126

A bridge in Desvio Dulces Sue os was affected by flooding.

Debris Flow, Patillas

When: November 8, 4:30 PM AST to 8:30 PM AST
Where: Patillas County, 1.31 mi E of Patillas to 1.48 mi E of Patillas
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.016, -65.981

A mudslide was registered on Road PR-757, KM 4.9 in Barrio Apiadero.

Flash Flood, Guayama

When: November 8, 4:30 PM AST to 8:49 PM AST
Where: Guayama County, 1.37 mi ESE of Guayama to 1.43 mi ESE of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.974, -66.110

Road PR-774, near Residencial Luis Pales Matos, was completely flooded and closed to traffic.

Debris Flow, Patillas

When: November 8, 4:30 PM AST to 8:30 PM AST
Where: Patillas County, 2.25 mi E of Patillas to 2.37 mi E of Patillas
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.016, -65.966

A mudslide was registered on Road PR-758 near Los Rios, sector Las Avispas. The mudslide affected the road, removing the pavement and infrastructure.

Flash Flood, Las Piedras

When: November 8, 5:00 PM AST to 9:30 PM AST
Where: Las Piedras County, 1.53 mi N of Las Piedras to 1.5 mi N of Las Piedras
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.202, -65.848

Emergency Managers reported four houses completely flooded in Barrio Boqueron, Calle Cruz De Malta.

Debris Flow, Guayama

When: November 8, 5:00 PM AST to 8:49 PM AST
Where: Guayama County, 5.66 mi NNE of Guayama to 5.81 mi NNE of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.057, -66.101

A mudslide was reported on Road PR-742, KM 2.3 in Barrio Carite. A house was affected.

Flash Flood, Las Piedras

When: November 8, 5:00 PM AST to 9:30 PM AST
Where: Las Piedras County, 3 mi NNE of Las Piedras to 2.88 mi NNE of Las Piedras
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.220, -65.832

Road PR-31 at Gulf Gas Station in Barrio Boqueron was completely under water.

Flash Flood, Guayama

When: November 8, 5:15 PM AST to 8:49 PM AST
Where: Guayama County, 1.27 mi ESE of Guayama to 1.3 mi ESE of Guayama
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.976, -66.111

Houses were flooded in Calle 9, Urbanization Vives.

Flash Flood, Las Piedras

When: November 8, 6:00 PM AST to 9:30 PM AST
Where: Las Piedras County, 1.55 mi WNW of Las Piedras to 1.08 mi NNW of Las Piedras
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.189, -65.871

Emergency managers reported that Road PR-936 was completely flooded and heavily damaged by rain.

Debris Flow, Las Piedras

When: November 8, 6:00 PM AST to 9:30 PM AST
Where: Las Piedras County, 0.42 mi ENE of Las Piedras to 0.49 mi E of Las Piedras
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.183, -65.845

Emergency managers reported a mudslide on Road PR-926 in Barrio Collores.

Flash Flood, Las Piedras

When: November 8, 7:00 PM AST to 9:30 PM AST
Where: Las Piedras County, 3.21 mi NNW of Las Piedras to 2.96 mi N of Las Piedras
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.225, -65.861

Road PR-9936 was flooded due to Rio Gurabo going out of its banks.

Flood, Naguabo

When: November 9, 7:50 PM AST to 8:50 PM AST
Where: Naguabo County, 3.04 mi W of Naguabo to 3.13 mi W of Naguabo
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.215, -65.776

Road PR-31, exit 22, was impassable due to flooding caused by Rio Blanco going out of its banks.

Flash Flood, Humacao

When: November 11, 4:02 PM AST to 10:00 PM AST
Where: Humacao County, 3.52 mi W of Humacao to 3.51 mi W of Humacao
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.124, -65.853

Persistent heavy rains caused a small stream to go out of its banks and flood portions of Road PR-909 KM 3.5 in Barrio Mariana.

Flood, Salinas

When: November 11, 4:30 PM AST to 5:54 PM AST
Where: Salinas County, 2.22 mi SE of Salinas to 2.41 mi SE of Salinas
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.973, -66.231

Emergency managers reported urban flooding along Road PR-3 KM 150. Road became impassable.

Flash Flood, Naguabo

When: November 11, 4:30 PM AST to 10:00 PM AST
Where: Naguabo County, 2.82 mi W of Naguabo to 2.98 mi NE of Naguabo
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.218, -65.773

Emergency reported Rio Blanco out of its banks, affecting portions of multiple roads including Road PR-31 in Sector La Fe, Sector Botijas, and Sector Pipina. Also, PR-973 in Barrio Marianna and PR-192.

Flash Flood, Patillas

When: November 11, 4:45 PM AST to 10:00 PM AST
Where: Patillas County, 2.32 mi S of Patillas to 3.07 mi SE of Patillas
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 17.986, -65.999

Emergency managers reported a stream out of its banks, affecting Road PR-3. A few cars were stranded and the road was impassible.

Flood, Ceiba

When: November 11, 5:03 PM AST to 7:00 PM AST
Where: Ceiba County, 3.54 mi WNW of Ceiba to 3.57 mi NNW of Ceiba
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.275, -65.677

Persistent heavy rains lead to minor flooding across portions of Roads PR-3, PR-977 and PR-975, making them impassable in some areas.

Flood, Fajardo

When: November 11, 5:13 PM AST to 7:00 PM AST
Where: Fajardo County, 1.23 mi NW of Fajardo to 2.09 mi NNW of Fajardo
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.334, -65.662

Persistent heavy rains lead to minor urban flooding along Avenida El Conquistador, making it impassable in some areas.

Flash Flood, Arroyo

When: November 11, 5:30 PM AST to 10:00 PM AST
Where: Arroyo County, 9.6 mi E of Arroyo to 9.77 mi E of Arroyo
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.004, -65.906

Emergency managers reported that Rio Maunabo went out of its banks, affecting Road PR-3 towards Patillas. Road was impassable.

Flash Flood, Las Piedras

When: November 11, 5:30 PM AST to 10:00 PM AST
Where: Las Piedras County, 3.75 mi N of Las Piedras to 3.18 mi N of Las Piedras
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.234, -65.859

Emergency managers reported multiple streams out of their banks affecting portions of Road PR-31. Portions of the road were impassable. Flood waters affected various houses.

Flood, Ponce

When: November 12, 12:46 AM AST to 2:45 AM AST
Where: Ponce County, 30.11 mi WSW of Cayey to 29.97 mi WSW of Cayey
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.006, -66.578

Road PR-1 was flooded at Mercedita Airport.

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.
Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
Debris Flow: A fast-moving slurry of mud, rock and debris, usually on a slope soaked by heavy rain or stripped by a fire.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Puerto Rico in 2020 Every state in 2020 This day in weather history Warnings in Puerto Rico, November 2020

Sources

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: 928729, 928730, 930414, 928732, 928733, 928734, 928743, 929820, 929836, 929838, 929846, 929849, 929851, 929856, 929857, 929858, 929943, 929949, 929950, 929952, 929956, 930374, 930375, 930376, 930377, 930378.