Flash Flood in Puerto Rico, May 1, 2002

Name: Flash Flood in Puerto Rico, May 1, 2002
Start: 2002-05-01T14:00
End: 2002-05-01T18:00
Location: Puerto Rico

May 1, 2002 · NWS SJU · 1 event in 1 county or zone

Heavy rains caused flash flooding over parts of Vega Alta, Vega Baja and Dorado. The Cibuco river in Vega Baja went out of its banks flooding several roads and low lying areas.

The toll

Deaths: 0
Injuries: 0
Property damage: $15,000
Crop damage: None recorded
Events: 1

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.

Heavy rains caused flash flooding over parts of Vega Alta, Vega Baja and Dorado. The Cibuco river in Vega Baja went out of its banks flooding several roads and low lying areas. Several houses were affected by the waters.

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 May 1, 9:14 AM AST, 4 hours 46 minutes earlier.

Area forecast discussion, May 1, 9:14 AM AST, 4 hours 46 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
914 AM AST WED MAY 1 2002

UPPER LEVEL TROUGH WITH TWO AXIS...THE PRIMARY AXIS LOCATED JUST
NORTHEAST OF FA...THE SECOND AXIS LOCATED ACROSS THE MONA
PASSAGE...WILL CONTINUES MOVING SLOWLY EAST THROUGH FRIDAY. THESE
FEATURES ARE PRODUCING UNSTABLE ATMOSPHERIC CONDITIONS ACROSS THE
LOCAL REGION WITH SOME UPPER LEVEL DIVERGENCE PER MRF MODEL. MODELS
HAVE ASSOCIATED MID LEVEL TROUGH OVER THE MONA PASSAGE AND EASTERN
HISPANOLA WITH SOME RISING MOTION. AT THE LOWER LEVELS...MRF HAS
THETA-E RIDGE (338K) MOVING ACROSS THE LOCAL AREA THIS MORNING
THROUGH TONIGHT...INDICATING AN INCREASE IN MOISTURE FOR TODAY...BUT
STARTING TO DECREASE BY 02/12Z TOMORROW MORNING. IN THE OTHER
HAND...AVN MODEL HAS RELATIVELY WET ATMOSPHERE ACROSS LOCAL
AREA...WITH PW AROUND 1.6 INCHES TO CONTINUE THROUGH THURSDAY
AFTERNOON...AND SLOWLY DECREASING THROUGH FRIDAY.

PRESSURE ANALYSIS INDICATE RELATIVELY WEAK PRESSURE GRADIENT ACROSS
LOCAL AREA TODAY AND THURSDAY...BECOMING TIGHT BY EARLY FRIDAY.
THEREFORE...EXPECT LIGHT WINDS TODAY AT THE LOWER LEVELS...EXCEPT
ALONG THE COASTS WERE SEA BREEZE WILL DEVELOP...AND INCREASING WINDS
BY FRIDAY AND SATURDAY.

12Z SOUNDING SHOWED SOME COLD AIR ADVECTION AT THE LOWER MID
LEVELS...PW OF 1.78 INCHES...AND LIGHT VEERING WITH HEIGHT WINDS
THROUGH AROUND 10 THOUSAND FEET. THE COMBINATION OF ALL THE
AFOREMENTIONED CONDITIONS ARE FAVORABLE FOR AFTERNOON CONVECTION TO
DEVELOP WITH SOME STRONG THUNDERSTORMS AND LOCALIZED VERY HEAVY
RAINS TO PRODUCE FLOODING FOR THIS AFTERNOON. AFTERNOON SHOWERS
ACTIVITY SHOULD DIMINISH ON FRIDAY AND SATURDAY.

MARINE GUIDANCE SUGGEST NEAR NORMAL CONDITIONS SHOULD PREVAIL
THROUGH THURSDAY WITH SEAS TO 3 TO 5 FEET. THEN...WITH INCREASING
WINDS SEAS STARTING ON FRIDAY...AND WEST-NORTHWEST SWELLS ARRIVING
TO OUR ATLANTIC WATERS EXPECT A GRADUAL INCREASE IN SEAS TO AROUND 6
FEET BY FRIDAY AFTERNOON...AND 6 TO 8 FEET BY EARLY SUNDAY.

EQUIPMENT: WSR-88D OTS FOR SCHEDULED MAINTENANCE ON CHANNEL 2...BUT
SHOULD RETURN BY 1600 UTC.

.SJU...
.PR...NONE.
.VI...NONE.

ROCHE

WRITTEN TEXT FORECASTS (IN ENGLISH OR SPANISH)...SATELLITE IMAGERY
...DOPPLER RADAR DATA...AND A VIRTUAL LIBRARY OF WEATHER INFORMATION
CAN BE FOUND AT THE NWS SAN JUAN WEB SITE AT:

HTTP://WWW.SRH.NOAA.GOV/SJU (ALL LOWER CASE).

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, North Central

When: May 1, 2:00 PM AST to 6:00 PM AST
Where: North Central County, East Portion
Property damage: $15,000
Reported by: EMERGENCY MANAGER

What these are

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.

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

The same day elsewhere

Every storm in Puerto Rico in 2002 Every state in 2002 This day in weather history Warnings in Puerto Rico, May 2002

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: 5293887.