Puerto Rico, 2004

Debris Flow in Puerto Rico, April 19, 2004

April 19, 2004 · NWS SJU · 1 event in 1 county or zone

1 debris flow, as filed by the National Weather Service.

The toll

Deaths
0
Injuries
0
Property damage
None recorded
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 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 Apr 19, 5:30 AM AST, 10 hours earlier.

Area forecast discussion, Apr 19, 5:30 AM AST, 10 hours before
FXCA62 TJSJ DDHHMM
AFDSJU

PUERTO RICO AND U.S. VIRGIN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN JUAN PR
530 AM AST MON APR 19 2004

.DISCUSSION...
AS HAS BEEN ADVERTISED PAST FEW DAYS...ABUNDANT MOISTURE CONVERGING
ALONG AND EAST OF A LOW LLVL TROF CURRENTLY ALONG EASTERN PUERTO
RICO...WILL MOVE SLOWLY WESTWARD ACROSS THE LOCAL AREA THROUGH THE
LATE EVENING HOURS TO YIELD SCATTERED TO NUMEROUS SHOWERS AND
ISOLATED TO LOCALLY SCATTERED THUNDERSTORMS. AN UPPER LEVEL TROUGH
JUST TO OUR NORTHWEST WILL PROVIDE UNSTABLE MID AND UPPER LEVEL
CONDITIONS TO ENHANCE CONVECTIVE ACTIVITY ACROSS THE REGION AND MAY
PRODUCE ITS MOST PRONOUNCED LIFT ACROSS THE REGION THIS AFTERNOON
AND EVENING. SOME AREAS WILL SEE VERY HEAVY RAINFALL. DRIER LLVL AIR
AND MORE STABLE CONDITIONS EXPECTED TUESDAY AFTERNOON THROUGH THE
REST OF THE WEEK BUT WITH UPPER TROUGH LINGERING CLOSE ENOUGH FOR AN
AFTERNOON TSTORM OR TWO POSSIBLE THROUGH MID WEEK ACROSS WRN P.R.

&&

.MARINE...
NELY FLOW TO THE WEST OF OLD SHEAR LINE AND MERGING LLVL TROF
COMBINING WITH PREVAILING ENE WIND SWELL AND SMALL NW SWELL FOR
COMBINED SEAS NEAR 7 FEET ACROSS FAR NORTH MONA PASSAGE...WITH
OFFSHORE ATLANTIC SEAS OTHERWISE 5-6 FEET. HAVE TRIED TO ALTER
MARINE GRAPHICS TO REFLECT FORECASTED MODEL TREND NEXT FEW DAYS.

&&

.HYDROLOGY...
IF RECENT DOPPLER RADAR TRENDS CONTINUE THROUGHOUT THE NEXT 12
HOURS...SCATTERED AREAS MAY SEE 1-2 INCHES TODAY WITH ISOLATED
PRECIP MAXES 4-6 INCHES POSSIBLE...AND 6-8 INCHES NOT OUT OF THE
QUESTION. THIS AMOUNT OF RAIN COULD OCCUR IN 2-6 HOURS AND WOULD
LEAD TO FLASH FLOODING. FLASH FLOOD WATCHES MAY NEED TO BE ISSUED
TODAY. INTERIOR SECTIONS OF P.R. ARE EXPECTED TO BE THE FOCUS OF THE
HEAVIEST RAINFALL OVER LAND NEXT 24 HOURS...WITH ST CROIX POISED FOR
SUFFICIENT MOISTURE AND RAINFALL AS WELL.

&&

.PRELIMINARY POINT TEMPS/POPS...
SJU  86  73  85  72 /  60  50  60  40
STT  85  72  84  71 /  60  40  30  50

&&

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

&&
Hazardous weather outlook, Apr 19, 6:00 AM AST, 9 hours 30 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN JUAN PR
600 AM AST MON APR 19 2004

PRZ001>013-AMZ710>750-201000-
600 AM AST MON APR 19 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO.

.TODAY AND TONIGHT...INCREASED MOISTURE AND INSTABILITY WILL
CONTINUE ACROSS THE LOCAL AREA THROUGH TONIGHT...WHICH WILL INCREASE
THE CHANCES OF RAINFALL AND THE POTENTIAL FOR SOME URBAN AND SMALL
STREAM FLOODING. THIS RAINFALL COULD ALSO PRODUCE SOME AREAS OF
RIVER FLOODING.

LONG PERIOD EAST NORTHEAST SWELLS WILL CONTINUE TO AFFECT THE LOCAL
ATLANTIC WATERS AND THE EASTERN CARIBBEAN PASSAGES THROUGH TODAY.

.SPOTTER CALL TO ACTION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.

.TUESDAY THROUGH SUNDAY...THERE WILL BE A GREATER AMOUNT OF
INSTABILITY AND MOISTURE OVER OUR LOCAL AREA THROUGH MUCH OF THE
WEEK WHICH WILL PRODUCE MORE WIDESPREAD SHOWER ACTIVITY.
LONG PERIOD EAST NORTHEAST SWELLS WILL CONTINUE TO AFFECT THE LOCAL
ATLANTIC WATERS AND THE EASTERN CARIBBEAN PASSAGES WITH A PEAK IN
SEA HEIGHTS EXPECTED AT NEAR 7 FEET IN THE OFF SHORE ATLANTIC WATERS
THIS AFTERNOON.

VIZ001-002-AMZ710>730-201000-
600 AM AST MON APR 19 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS.

.TODAY AND TONIGHT...INCREASED MOISTURE AND INSTABILITY OVER THE
LOCAL AREA THROUGH TONIGHT WILL INCREASE THE CHANCES OF
RAINFALL AND THE POTENTIAL FOR SOME URBAN AND SMALL STREAM FLOODING.

LONG PERIOD EAST NORTHEAST SWELLS WILL CONTINUE TO AFFECT THE LOCAL
ATLANTIC WATERS AND THE EASTERN CARIBBEAN PASSAGES THROUGH TODAY.

.SPOTTER CALL TO ACTION STATEMENT...
SPOTTER ACTIVATION IS NOT ANTICIPATED TODAY.

.TUESDAY THROUGH SUNDAY...THERE WILL BE A GREATER AMOUNT OF
INSTABILITY AND MOISTURE OVER OUR LOCAL AREA THROUGH MUCH OF THE
WEEK WHICH WILL PRODUCE AN OVERALL INCREASE IN SHOWER ACTIVITY
THROUGH THE WEEK.
LONG PERIOD EAST NORTHEAST SWELLS WILL CONTINUE TO AFFECT THE LOCAL
ATLANTIC WATERS AND THE EASTERN CARIBBEAN PASSAGES WITH A PEAK IN
SEA HEIGHTS EXPECTED AT NEAR 7 FEET OFF SHORE ATLANTIC WATERS THIS
AFTERNOON.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE WEB
SITE FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS AT (ALL LOWERCASE
LETTERS): HTTP://WWW.SRH.NOAA.GOV/SJU.

Event by event

1 debris flow. Local standard time, as filed.

Debris Flow, Mayaguez and Vicinity

When
April 19, 3:30 PM AST
Where
Mayaguez and Vicinity forecast zone
Reported by
EMERGENCY MANAGER

A landslide was reported in the municipality of San German.

What these are

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

More

Every storm in Puerto Rico in 2004Every state in 2004This day in weather historyWarnings in Puerto Rico, April 2004

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: 5390260.