An upper level trough located west of Puerto Rico, combined with a strong upper level jet and moisture advected from the southeast, to produce numerous showers with thunderstorms across the region. The western interior section of Puerto Rico was the most affected with total rainfall accumulation exceeding 7 inches in the municipality of Utuado.
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.
The episode as NWS SJU wrote it up.
An upper level trough located west of Puerto Rico, combined with a strong upper level jet and moisture advected from the southeast, to produce numerous showers with thunderstorms across the region. The western interior section of Puerto Rico was the most affected with total rainfall accumulation exceeding 7 inches in the municipality of Utuado. Several mudslides were reported as well as urban and small stream flooding.
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 29, 3:35 PM AST, 3 hours 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 335 PM AST FRI APR 29 2011 .SYNOPSIS...BROAD SURFACE HIGH PRESSURE OVER THE NORTH CENTRAL ATLANTIC WILL CONTINUE TO PROMOTE A MODERATE TO LOCALLY FRESH TRADE WIND FLOW ACROSS THE NORTHEASTERN CARIBBEAN ISLES THROUGH AT LEAST LATE SATURDAY. THIS SURFACE HIGH WILL SLOWLY PULL TO THE EAST NORTHEAST AS POLAR TROUGH MOVES ACROSS THE EASTERN USA TO THE WESTERN ATLANTIC. AFTERWARDS...ANOTHER HIGH PRESSURE WILL ESTABLISH NORTH OF PUERTO RICO EARLY NEXT WEEK. && .DISCUSSION...SATELITTE IMAGERY AND CURRENT SURFACE ANALYSIS REVEAL A STRONG HIGH PRESSURE CENTERED OVER THE NORTH CENTRAL ATLANTIC. THIS FEATURE IS PRODUCING A BROAD ANTICYCLONIC FLOW ACROSS THE NORTH ATLANTIC THAT IS PROMOTING A MODERATE TO LOCALLY FRESH TRADE WIND FLOW ACROSS THE LOCAL REGION. THE MID/UPPER LEVEL TROUGH NORTHEAST OF THE REGION WILL PULL/LIFT NORTHEAST AS A POLAR TROUGH MOVES INTO THE WESTERN ATLANTIC EARLY NEXT WEEK. ANOTHER HIGH PRESSURE OVER THE EASTERN USA SLIDES OFF THE COAST INTO THE WESTERN ATLANTIC ON MONDAY. THIS WIND REGIME ACROSS THE LOCAL REGION TENDS TO BRING SHOWERS TO WINDWARD AREAS DURING NIGHTS AND MORNINGS...WITH SEA BREEZE CONVERGENCE OVER LEEWARD AREAS LEADING TO CLOUDS AND SHOWERS OVER INTERIOR AND WESTERN SECTIONS DURING AFTERNOONS AND EARLY EVENINGS THROUGH THE WEEKEND. GLOBAL MODELS ARE FORECASTING A SURGE OF MOISTURE AND BETTER CHANCE FOR ACTIVE WEATHER LATE SUNDAY INTO THE EARLY PART OF NEXT WEEK...AS UPPER LEVEL RIDGE ERODES ACROSS THE AREA DUE TO APPROACHING MID TO UPPER LEVEL SHORT WAVE TROUGH. THE EVOLVING PATTERN WILL FAVOR THE MOISTURE ADVECTION FROM THE EAST SOUTHEAST ACROSS PUERTO RICO AND VIRGIN ISLANDS...WITH PW VALUES TO PEAK AROUND 1.8 INCHES BY TUESDAY MORNING. && .AVIATION...SHWRS WILL CONT DOWNSTREAM FROM TISX AND OVER WESTERN PUERTO RICO WITH SOME TOPS NEAR 35 KFT IN TSTMS. SHWRS WILL DIMINISH OVER PR AFT 29/22Z AND MTN OBSCURATIONS AFT 30/03Z. SOME BRIEF MVFR MAY OCCUR AT TJMZ OTHERWISE ALL STATIONS WILL HAVE PREDOMINATELY VFR CONDS. LLVL WINDS E-ENE 10 TO 25 KTS BELOW 10 KFT...STRONGEST FROM 1-4 KFT. && .MARINE...SEAS WILL SLOWLY SUBSIDE DURING THE WEEKEND ACROSS THE COASTAL WATERS. HOWEVER...SEAS BETWEEN 6 TO 7 FEET WILL CONTINUE TO AFFECT THE OFFSHORE ATLANTIC WATERS THROUGH SATURDAY EVENING. AS A RESULT...A SMALL CRAFT ADVISORY FOR THE OFFSHORE ATLANTIC WATERS REMAINS IN EFFECT THROUGH SATURDAY EVENING. && .PRELIMINARY POINT TEMPS/POPS... SJU 74 86 75 86 / 10 10 20 30 STT 76 86 76 86 / 20 20 20 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...SCA FOR AMZ-710. VI...SCA FOR AMZ-710. && 12/11
HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS NATIONAL WEATHER SERVICE SAN JUAN PR 600 AM AST FRI APR 29 2011 AMZ710>745-PRZ001>013-301000- 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- 600 AM AST FRI APR 29 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION PARTICULARLY OVER THE OFFSHORE ATLANTIC WATERS. WINDS AND SEAS WILL BE DECREASING SLOWLY TODAY BUT REMAIN BE LOCALLY ROUGH AND HAZARDOUS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. AMZ715-725-VIZ001-002-301000- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 600 AM AST FRI APR 29 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT SMALL BOAT OPERATORS SHOULD EXERCISE CAUTION PARTICULARLY OVER THE OFFSHORE ATLANTIC WATERS. WINDS AND SEAS WILL BE DECREASING SLOWLY TODAY BUT REMAIN LOCALLY ROUGH AND HAZARDOUS. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
5 debris flow. Local standard time, as filed.
A mudslide was reported along the Rolando Caba as avenue behind Colegio San Jose in Utuado. Two homes were affected.
A mudslide was reported in road 111, Km 10.7 close to El Cacique restaurant in Barrio Caguana in the municipality of Utuado.
A mudslide was reported in Barrio Guanico, Road 603 in the municipality of Utuado.
A mudslide was reported in Barrio Caguana Road 111, Km 3.2 and Road 123, Km 1.8 in the municipality of Utuado.
A mudslide was reported at Road 611,km 0.8 in Barrio Sabana Grande in the municipality of Utuado.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2011Every state in 2011This day in weather historyWarnings in Puerto Rico, April 2011
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: 287942, 289198, 289199, 289200, 303523.