Flash Flooding and Debris Flow in Puerto Rico, January 13 to 15, 2010

Name: Flash Flooding and Debris Flow in Puerto Rico, January 13 to 15, 2010
Start: 2010-01-13T17:15
End: 2010-01-15T22:30
Location: Puerto Rico

January 13 to 15, 2010 · NWS SJU · 11 events in 8 counties and zones

A frontal boundary draped across northern Puerto Rico producing persistent light to moderate showers which resulted in significant rainfall accumulations across much of the northern half and the eastern section of Puerto Rico. Most of the reported flooding could be categorized as urban and small stream flooding while the most significant river impacts were experienced along the Rio Cibuco, Rio…

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: $25,000
Crop damage: None recorded
Events: 11

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.

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 Jan 13, 2:52 PM AST, 2 hours 23 minutes earlier.

Area forecast discussion, Jan 13, 2:52 PM AST, 2 hours 23 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
252 PM AST WED JAN 13 2010

.SYNOPSIS...AN AREA OF HIGH PRESSURE WILL MOVE ACROSS THE EASTERN
UNITED STATES SEABOARD BY THURSDAY. THIS FEATURE WILL FORCE THE
FRONTAL BOUNDARY REMNANTS ACROSS HISPANIOLA AND THE ATLANTIC
WATERS NORTHWEST OF PUERTO RICO TO MOVE ACROSS THE LOCAL ATLANTIC
WATERS AND ACROSS PART OF THE LOCAL ISLANDS THURSDAY THROUGH
SATURDAY.

&&

.DISCUSSION...SATELLITES IMAGES THIS AFTERNOON DEPICTED ABUNDANT
CLOUDINESS EXTENDING FROM HISPANIOLA...EAST NORTHEASTWARD ACROSS
THE ATLANTIC FOR SEVERAL HUNDRED MILES. THIS MOISTURE IS
ASSOCIATED WITH THE REMNANTS OF AN OLD FRONTAL BOUNDARY STALLED TO
THE NORTHWEST OF PUERTO RICO FOR THE LAST FEW DAYS. THIS FEATURE
WILL CONTINUE TO PROVIDE SOME INSTABILITY FOR THE DEVELOPMENT OF
SCATTERED SHOWERS AND A FEW AFTERNOON THUNDERSTORMS ESPECIALLY
ACROSS WESTERN AND INTERIOR SECTIONS OF PUERTO RICO OVER THE NEXT
FEW DAYS. THIS ACTIVITY WILL LIKELY PERSIST INTO THE EVENING
HOURS...ESPECIALLY THURSDAY AND FRIDAY. IN FACT...LATEST RADAR
OBSERVATIONS THIS AFTERNOON SHOWED SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER SOUTHWESTERN SECTIONS OF PUERTO RICO AND ACROSS
THE INTERIOR...SOUTHWEST OF THE METROPOLITAN AREA.

A SURFACE HIGH PRESSURE SYSTEM...WILL MOVE ACROSS THE WESTERN
ATLANTIC BY THURSDAY. THIS HIGH PRESSURE SYSTEM WILL HELP TO PUSH
THE FRONTAL BOUNDARY REMNANTS ACROSS THE LOCAL ATLANTIC WATERS AND
THE NORTHERN SECTIONS OF THE LOCAL ISLANDS BY THE END OF THE
WEEK...INCREASING THE CHANCES OF SHOWERS...ESPECIALLY OVER THE
NORTHERN HALF OF PUERTO RICO. THE GFS MODEL GUIDANCE SUGGESTS THAT
THE FRONTAL BOUNDARY REMNANTS WILL THEN LIFT NORTHWARD ACROSS THE
ATLANTIC WATERS BY THE UPCOMING WEEKEND. A HIGH PRESSURE SYSTEM WILL
THEN BUILD ACROSS THE REGION BY EARLY NEXT WEEK...LIMITING AGAIN THE
CHANCES OF PRECIPITATION.

&&

.AVIATION...VOLCANIC ASH SHOULD BE DIFFUSE AS IT PASSES TISX ON WEST
NORTHWEST COURSE. EXPECT SAME CLOUD TO PASS TIST ARND
13/21Z-14/02Z.

GFS AND NAM FORECASTS DIVERGE TOO MUCH TO MAINTAIN STRONG CONFIDENCE
IN REST OF FORECAST. SHOWERS HAVE DEVELOPED OVER THE MAINLAND AS
EXPECTED BUT BOUNDARY OF OLD FRONTAL ZONE REMAINS WELL TO THE
NORTHWEST AND IT IS NOT CLEAR THAT STRONG CONVECTION OF NAM OVER
INTERIOR NOW THROUGH 14/12Z CAN MATERIALIZE OR MAINTAIN AHEAD OF IT.
FOR NOW WILL INDICATE CIGS DEVELOPING OVER PUERTO RICO AT VFR LEVELS
AT TAF SITES AND SOME MOUNTAIN OBSCURATIONS WITH SCATTERED SHOWERS
THROUGH 14/18Z. SOME MVFR PSBL FOR TJMZ AND TJBQ TIL 14/00Z. LESS
WEATHER INDICATED FOR TIST...TISX...TNCM...TKPK. SHOULD PULSE FROM
BOUNDARY TO NORTH EMERGE RAPIDLY AS FORECAST IN NAM EXPECT MORE
WIDESPREAD SHWRS...MORE NORTHERLY WINDS AND MUCH LOWER CIGS INLAND.

&&

.MARINE...MODERATE...NORTH NORTHWESTERLY SWELLS WILL CONTINUE TO
SLOWLY SUBSIDE ACROSS THE LOCAL ATLANTIC WATERS THIS EVENING.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  74  80  73  81 /  50  50  40  40
STT  74  83  73  83 /  30  30  20  40

&&

.SJU WATCHES/WARNINGS/ADVISORIES...
PR...NONE.
VI...NONE.
&&

12/72

Hazardous weather outlook, Jan 13, 5:11 AM AST, 12 hours 4 minutes before

HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN
ISLANDS
NATIONAL WEATHER SERVICE SAN JUAN PR
511 AM AST WED JAN 13 2010

AMZ710>745-PRZ001>013-140915-
SAN JUAN AND VICINITY-NORTHEAST-SOUTHEAST-EASTERN INTERIOR-
NORTH CENTRAL-CENTRAL INTERIOR-PONCE AND VICINITY-NORTHWEST-
WESTERN INTERIOR-MAYAGUEZ AND VICINITY-SOUTHWEST-CULEBRA-VIEQUES-
THE NEARSHORE AND OFF SHORE ATLANTIC AND CARIBBEAN COASTAL WATERS-
511 AM AST WED JAN 13 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE
ADJACENT COASTAL WATERS.

.DAY ONE...TONIGHT

SWELL FROM THE NORTH NORTHWEST WILL IMPACT THE NORTHERN COASTS
TODAY WITH BREAKING WAVES POSSIBLY REACHING 10 FEET IN A FEW
AREAS. THERE IS A HIGH RISK OF RIP-CURRENTS...ESPECIALLY AS THESE
SWELL BEGIN TO SUBSIDE. THERE IS ALSO A SLIGHT RISK OF URBAN AND
SMALL STREAM FLOODING IN THE NORTHWEST PORTION OF PUERTO RICO THIS
AFTERNOON WHERE SHOWERS FORM. OVER 2 INCHES WERE OBSERVED IN SOME
AREAS THERE YESTERDAY AND STREAMS MAY FILL MORE QUICKLY TODAY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

AMZ715-725-VIZ001-002-140915-
ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX-
NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS-
511 AM AST WED JAN 13 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND
THE ADJACENT COASTAL WATERS.

.DAY ONE...TONIGHT

SWELL FROM THE NORTH NORTHWEST WILL IMPACT THE NORTHERN COASTS
TODAY WITH BREAKING WAVES POSSIBLY REACHING 10 FEET IN A FEW
AREAS. THERE IS A HIGH RISK OF RIP-CURRENTS...ESPECIALLY AS THESE
SWELL BEGIN TO SUBSIDE.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED.

The radar

The San Juan radar (TJUA), 40 km away, was scanning. The volume nearest the first event began at 21:16 UTC.

Open the radar archive at this moment

Event by event

5 flood, 3 flash flood, 2 heavy rain, 1 debris flow. Local standard time, as filed.

Flood, San Juan

When: January 13, 5:15 PM AST to January 14, 12:00 PM AST
Where: San Juan County, 10.79 mi WNW of San Juan to 4.69 mi WNW of San Juan
Cause: Heavy Rain
Property damage: $15,000
Reported by: Emergency Manager
Coordinates: 18.462, -66.190

Flooding of roads and streets was reported along many sectors of San Juan and adjacent municipalities in association to a frontal boundary that became stationary. The heaviest rainfall fell in the Santurce area of San Juan. Some stranded cars and flooded homes were reported.

Flash Flood, Vega Alta

When: January 13, 9:53 PM AST to 11:53 PM AST
Where: Vega Alta County, 1.64 mi SW of Vega Alta
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.400, -66.344

River Cibuco overflowed its banks along road 620 in the Candelaria sector of Vega Alta.

Flash Flood, Catano

When: January 14, 5:28 PM AST
Where: Catano County, 0.73 mi WNW of Catano to 1.11 mi NW of Catano
Cause: Heavy Rain
Property damage: $10,000
Reported by: Emergency Manager
Coordinates: 18.435, -66.130

Eight to ten families were evacuated from their homes due to flash flooding near the Juana Matos sector, Puente Blanco and Cucharillas.

Heavy Rain, Barceloneta

When: January 14, 6:00 PM AST to 8:45 PM AST
Where: Barceloneta County, Barceloneta
Reported by: Emergency Manager
Coordinates: 18.430, -66.550

Road 140 in Barrio catanito flooded due to heavy rains.

Flash Flood, Fajardo

When: January 14, 6:00 PM AST to 8:45 PM AST
Where: Fajardo County, 0.24 mi SW of Fajardo to 0.44 mi SW of Fajardo
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.318, -65.653

The Fajardo river overflowed its banks and flooded portions of the road intersecting highway 3 and highway 53 in Fajardo.

Heavy Rain, Vega Baja

When: January 15, 12:00 AM AST to 8:15 AM AST
Where: Vega Baja County, Vega Baja
Reported by: Emergency Manager
Coordinates: 18.450, -66.380

Route 160 along Highway 2 in Almirante Norte was impassable due to high water.

Flood, Vega Alta

When: January 15, 10:25 AM AST to 4:30 PM AST
Where: Vega Alta County, 1.64 mi SW of Vega Alta
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.400, -66.344

Road 620 from the Maricao sector to the Fatima sector of Vega Alta was reported flooded. Rivers Cibuco and Mavilla were also reported approaching bankfull.

Flood, Vega Alta

When: January 15, 3:30 PM AST to 10:30 PM AST
Where: Vega Alta County, 1.61 mi WNW of Vega Alta to 1.46 mi WNW of Vega Alta
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.433, -66.351

Road 676 in Sector Bajuras was closed due to flooding.

Flood, Loiza

When: January 15, 3:30 PM AST to 4:30 PM AST
Where: Loiza County, 1.93 mi SSW of Loiza to 0.37 mi SSW of Loiza
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.394, -65.912

The Loiza river flood waters were eroding parts of road 951.

Debris Flow, San Juan and Vicinity

When: January 15, 3:30 PM AST
Where: San Juan and Vicinity forecast zone
Reported by: Emergency Manager

Mudslides with rocks were reported along road 941 in Barrio La Gloria. A rock fell into road 181 in sector Dos Bocas in Trujillo Alto.

Flood, Vega Alta

When: January 15, 4:20 PM AST to 10:30 PM AST
Where: Vega Alta County, 0.98 mi SW of Vega Alta to 1.77 mi SW of Vega Alta
Cause: Heavy Rain
Reported by: Emergency Manager
Coordinates: 18.409, -66.340

Roads 620 and 647 in Vega Alta remain closed due to flooding.

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.
Heavy Rain: Rainfall totals unusual for the place and season that did not produce a flood.
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 2010 Every state in 2010 This day in weather history Warnings in Puerto Rico, January 2010

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 2026-10-01. Each event’s entry at NCEI: 214949, 216211, 214950, 211745, 213823, 211766, 216226, 216241, 216245, 216248, 216234.