An upper level trough across the Mona passage generated an outflow boundary, producing very heavy rainfall and strong gusty winds across the San Juan metro area, North Central and Western Interior sections of Puerto Rico. Also, this upper level trough combined with strong daytime heating and favorable upper level dynamics to produce scattered to numerous showers with thunderstorms.
Every event with a place to put it. Tap one for its entry below.
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 across the Mona passage generated an outflow boundary, producing very heavy rainfall and strong gusty winds across the San Juan metro area, North Central and Western Interior sections of Puerto Rico. Also, this upper level trough combined with strong daytime heating and favorable upper level dynamics to produce scattered to numerous showers with thunderstorms.
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 10, 3:04 PM AST, 1 hour 58 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 304 PM AST FRI MAY 10 2013 .SYNOPSIS...AT MID AND UPPER LEVELS...A TROUGH IS PASSING THROUGH THE LOCAL AREA AND SHORT WAVES WILL PASS THROUGH THIS THROUGH SUNDAY. A RIDGE WILL MOVE THROUGH THE AREA ON TUESDAY FOLLOWED BY ANOTHER BROAD TROUGH ON THURSDAY. THE CORE OF THE JET WILL PASS OVERHEAD TONIGHT AT UPPER LEVELS. AT LOWER LEVELS...HIGH PRESSURE WILL CONTINUE TO BUILD UNTIL TUESDAY IN THE NORTH CENTRAL ATLANTIC GENERATING MODERATE TO FRESH TRADE WIND FLOW OVER THE AREA. A TROUGH NORTH OF HISPANIOLA AND THE MONA CHANNEL WILL PASS THROUGH PUERTO RICO AND THE U.S. VIRGIN ISLANDS TONIGHT GENERATING SHOWERS AND THUNDERSTORMS FOLLOWED BY DRIER AIR ON SUNDAY. PATCH MOISTURE WILL CONTINUE THROUGH THE REST OF NEXT WEEK WITH WEAKER FLOW AS HIGH PRESSURE WEAKENS AND LOW PRESSURE FORMS WELL NORTH OF THE AREA WEDNESDAY AND MOVES NORTHEAST ON THURSDAY. && .DISCUSSION...STRONG THUNDERSTORMS ASSOCIATED WITH AN UPPER LEVEL TROUGH NORTH OF HISPANIOLA AND THE MONA CHANNEL HAVE GENERATED AN OUTFLOW BOUNDARY THAT ENTERED THE NORTHWESTERN PORTION OF OUR LOCAL ATLANTIC WATERS AFTER NOON. IT IS MOVING SOUTHEAST AT ABOUT 16-20 KNOTS AND IS EXPECTED TO REACH PUERTO RICO BETWEEN 10/21-22Z. EAST SOUTHEAST WINDS WILL SHIFT ABRUPTLY TO THE NORTHWEST OR NORTH AS IT PASSES THROUGH AMZ710 AND AMZ712 AND AMZ741. IT SHOULD BE SOMEWHAT WEAKER BY THE TIME IT REACHES AGUADILLA BUT MAY STILL PRODUCE VIGOROUS SHOWERS OVER THE NORTHWESTERN TWO THIRDS OF PUERTO RICO. THE GFS INDICATES THAT GOOD MOISTURE AT LOWER LEVELS WILL CONTINUE TONIGHT THROUGH SUNDAY MORNING AND THIS WILL ENSURE THAT SHOWERS CONTINUE ON THE WINDWARD SIDE OF PUERTO RICO. SHOWERS WILL ALSO MOVE ACROSS THE CARIBBEAN WATERS OVER THE U.S. VIRGIN ISLANDS. ON SATURDAY NIGHT A WEAK LOW PRESSURE AT 850 MB IS DEPICTED JUST NORTH OF THE FORECAST AREA...AND WINDS DROP TO NEAR ZERO...OTHERWISE SOUTHEAST FLOW CONTINUES WELL INTO THE MIDDLE OF NEXT WEEK. SINCE LOW LEVEL FLOW IS QUITE MOIST EXPECT PERSISTENT SHOWER ACTIVITY ON THE SOUTHEAST SIDE OF THE ISLAND NIGHT AND MORNINGS AND SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE WESTERN PORTION IN THE AFTERNOONS MONDAY THROUGH FRIDAY. UPPER LEVEL FLOW WILL NOT BE AS CONDUCIVE TO DEEP CONVECTION AFTER SUNDAY MORNING...BUT SOME OF THE SHOWERS WILL HAVE HEAVY RAIN. && .AVIATION... AN OUTFLOW BOUNDARY APPROACHING THE ATLANTIC COASTAL WATERS FROM THE NORTHWEST WILL ARRIVE AROUND 21Z...THEREFORE...EXPECT BRIEF PERIODS OF GUSTY WIND SHIFTS. VCTS/SHRA ARE FORECASTED FOR TJBQ AND TJSJ. MAINLY ESE WINDS BETWEEN 10 TO 20 KTS ARE EXPECTED ACROSS MOST TAF SITES. LATE TONIGHT AN INCREASE ON VCTS/SHRA IS POSSIBLE OVER THE ISLANDS. && .MARINE...AN OUTFLOW BOUNDARY IS MOVING SOUTHEAST INTO THE LOCAL WATERS...BUT WINDS ARE NOT EXPECTED TO REACH 20 KNOTS SUSTAINED...SOME GUSTS MAY BE HIGHER HOWEVER. WINDS AND SEAS ARE EXPECTED TO DIMINISH AFTER TONIGHT THROUGH SUNDAY AND THEN CHANGE ONLY A LITTLE. && .PRELIMINARY POINT TEMPS/POPS... SJU 73 84 74 88 / 50 50 40 40 STT 75 86 76 86 / 60 60 40 40 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. COASTAL WATERS...NONE. && 13/12
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 559 AM AST FRI MAY 10 2013 AMZ710>745-PRZ001>013-111000- 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- 559 AM AST FRI MAY 10 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT DUE TO ALREADY SATURATED SOILS...ANY ADDITIONAL RAINFALL WILL LIKELY RESULT IN RAPID RISES IN SMALL STREAMS AND RIVERS AS WELL AS INCREASE THE POTENTIAL FOR MUDSLIDES IN AREAS OF STEEP TERRAIN. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY THE POTENTIAL FOR LOCALIZED FLOODING CONTINUES INTO THE WEEKEND AS PERIODS OF HEAVY RAINFALL REMAIN IN THE FORECAST. .SPOTTER INFORMATION STATEMENT...REPORTS OF LOCALLY HEAVY RAINFALL AND ANY SIGNIFICANT FLOODING WOULD BE APPRECIATED. AMZ715-725-VIZ001-002-111000- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 559 AM AST FRI MAY 10 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT PROLONGED PERIODS OF MODERATE TO HEAVY RAINFALL WILL LIKELY RESULT IN URBAN FLOODING...RAPID RISES IN SMALL STREAMS AND CREEKS AS WELL AS INCREASE THE POTENTIAL FOR MUDSLIDES IN AREAS OF STEEP TERRAIN. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT...REPORTS OF LOCALLY HEAVY RAINFALL AND ANY SIGNIFICANT FLOODING WOULD BE APPRECIATED.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN JUAN PR 343 PM AST FRI MAY 10 2013 PRC017-054-091-143-145-102045- BARCELONETA PR-FLORIDA PR-MANATI PR-VEGA ALTA PR-VEGA BAJA PR- 343 PM AST FRI MAY 10 2013 ...SIGNIFICANT WEATHER ADVISORY FOR STRONG THUNDERSTORMS OVER BARCELONETA... AT 339 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 3 MILES NORTHWEST OF FLORIDA...MOVING NORTHEAST AT 20 MPH. LIGHTNING...SATELLITE AND RADAR TRENDS INDICATE THUNDERSTORMS RAPIDLY INTENSIFYING OVER BARCELONETA. EXPECT GUSTY WINDS TO 30 MPH...FREQUENT AND INTENSE LIGHTNING AND BRIEF HEAVY RAINFALL. INTENSE LIGHTNING IS REPORTED WITH THIS STORM. IF OUTDOORS...STAY AWAY FROM ISOLATED HIGH OBJECTS SUCH AS TREES. MOVE INDOORS IF POSSIBLE. WHEN INDOORS...STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING TELEPHONES UNLESS IT IS AN EMERGENCY. TRY TO UNPLUG UNNECESSARY ELECTRICAL APPLIANCES BEFORE THE THUNDERSTORM APPROACHES. ROSA
COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO SERVICIO NACIONAL DE METEOROLOGIA SAN JUAN PR 343 PM AST VIERNES 10 DE MAYO DE 2013 PRC017-054-091-143-145-102045- BARCELONETA PR-FLORIDA PR-MANATI PR-VEGA ALTA PR-VEGA BAJA PR- 343 PM AST VIERNES 10 DE MAYO DE 2013 ...ADVERTENCIA DE CONDICIONES SIGNIFICATIVAS DEBIDO A FUERTES TRONADAS SOBRE BARCELONETA... A LAS 3:39 PM AST...EL RADAR DOPPLER DEL SERVICIO NACIONAL DE METEOROLOGIA INDICO UNA TRONADA FUERTE 3 MILLAS AL NOROESTE DE FLORIDA...MOVIENDOSE NORESTE AT 20 MPH. EL RADAR Y LAS IMAGENES DE SATELITE INDICAN QUE ESTAS TRONADAS SE INTENSIFICARAN RAPIDAMENTE SOBRE BARCELONETA. SE ESPERAN VIENTOS EN RAFAGAS DE HASTA 30 MPH... INTENSOS Y FRECUENTES RAYOS Y BREVES PERO FUERTES LLUVIAS. SE HA REPORTADO INTENSOS RELAMPAGOS CON ESTAS TORMENTAS. SI SE ENCUENTRA AFUERA...MANTENGASE ALEJADO DE OBJETOS ALTOS COMO ARBOLES. MUEVASE ADENTRO DE UNA ESTRUCTURA SI ES POSIBLE. CUANDO ESTA ADENTRO MANTENGASE ALEJADO DE PUERTAS Y VENTANAS EVITE USAR TELEFONOS A MENOS QUE SEA UNA EMERGENCIA. TRATE DE DESENCHUFAR ENSERES ELECTRICOS ANTES QUE SE ACERQUE LA TORMENTA. ROSA/JAE
The national radar mosaic for the moment the first event began.
4 flood, 2 flash flood. Local standard time, as filed.
Quebrada Machuchal and Quebrada Honda both were out of its banks.
Road PR-111 flooded due to heavy rain and Anon creek, Molino creek, Rio Montebello and Rio Guajataca were out of its banks. Some residence were affected in Seburuquillo sector.
Urban flooding was reported at San Patricio Plaza shopping center.
Parts of Roosevelt Road Avenue flooded in Hato Rey sector.
Rio Blanco was reported out of its banks flooding road PR-31.
Flooding occured at intersection between roads PR-3 and PR-8.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2013Every state in 2013This day in weather historyWarnings in Puerto Rico, May 2013
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: 456993, 456997, 456998, 456999, 457000, 457001.