The combination of good moisture and instability, combined with local effects and an upper level trough to produced scattered to numerous showers with thunderstorms mainly over the interior and southwest sections of Puerto Rico.
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.
The combination of good moisture and instability, combined with local effects and an upper level trough to produced scattered to numerous showers with thunderstorms mainly over the interior and southwest sections of Puerto Rico.
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 Sep 15, 4:12 PM AST, 38 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 412 PM AST SAT SEP 15 2012 .SYNOPSIS...TUTT WILL CONTINUE TO SHIFT WEST TONIGHT...AS MID TO UPPER LEVEL RIDGE EXTENDS ACROSS THE LOCAL AREA FOR SUNDAY AND MONDAY. AN ACTIVE TROPICAL WAVE WILL AFFECT THE REGION MONDAY AFTERNOON AND NIGHT THROUGH AT LEAST TUESDAY OR TUESDAY NIGHT. && .DISCUSSION...HAD ANOTHER ACTIVE WEATHER AFTERNOON TODAY...THANKS TO THE COMBINATION OF GOOD MOISTURE AND INSTABILITY...LOCAL EFFECTS AND THE TUTT AXIS IN A GOOD LOCATION TO ACTIVELY VENTILATE THE DEVELOPING SHOWERS AND THUNDERSTORMS. EXPECT AFTERNOON CONVECTION TO GRADUALLY DIMINISH AND END THIS EVENING...BUT THIS MAY TAKE AT LEAST A COUPLE OF MORE HOURS. AS TUTT CONTINUES MOVING WEST TONIGHT...MID TO UPPER LEVEL RIDGE WILL ENCOMPASS THE LOCAL AREA FOR SUNDAY AND MONDAY. THIS SHOULD TRANSLATE INTO AN "OVERALL" DRIER AND MORE STABLE PATTERN...BUT STILL EXPECT SOME CLOUDINESS...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS EACH AFTERNOON. EXPECT TROPICAL WAVE CURRENTLY EAST OF THE WINDWARD ISLANDS...TO CONTINUE MOVING WEST TO WEST NORTHWEST TONIGHT THROUGH SUNDAY NIGHT AND MONDAY...AND THEN BEGIN TO AFFECT THE LOCAL AREA MONDAY AFTERNOON AND NIGHT...WITH ASSOCIATED ACTIVE WEATHER PROBABLY CONTINUING THROUGH AT LEAST TUESDAY OR TUESDAY NIGHT. WE WILL NEED TO CONTINUE TO MONITOR THIS TROPICAL WAVE...AS IT HAS THE POTENTIAL TO PRODUCE A SIGNIFICANT INCREASE IN SHOWERS AND THUNDERSTORMS ACROSS THE LOCAL ISLANDS. && .AVIATION...VFR CONDITIONS EXPECTED FOR THE USVI/BVI TERMINALS... WHILE SHRA/TSRA ACROSS PUERTO RICO ARE EXPECTED THROUGH THE REST OF THE AFTERNOON HOURS. TERMINALS IN PR MAY OBSERVE VCTS UNTIL 15/22Z...AND TJMZ MAY OBSERVE TSRA UNTIL THAT TIME. CONDITIONS ARE EXPECTED TO IMPROVE AFTER 16/00Z...LEAVING VFR CONDITIONS FOR THE LOCAL TAF SITES OVERNIGHT. && .MARINE...GENERALLY EXPECT WINDS OF 17 KNOTS OR LESS AND SEAS OF 6 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST MONDAY. EAST NORTHEAST SWELLS WILL CONTINUE TO SLOWLY SUBSIDE ACROSS THE WATERS TONIGHT...BUT SMALL BOAT OPERATORS SHOULD CONTINUE TO EXERCISE CAUTION ACROSS THE LOCAL ATLANTIC OFF SHORE WATERS. && .PRELIMINARY POINT TEMPS/POPS... SJU 78 90 78 90 / 20 20 20 20 STT 78 89 79 89 / 20 20 20 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. COASTAL WATERS...NONE. && 25/06
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 652 AM AST SAT SEP 15 2012 AMZ710>745-PRZ001>013-161100- 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- 652 AM AST SAT SEP 15 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. AMZ715-725-VIZ001-002-161100- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 652 AM AST SAT SEP 15 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SAN JUAN PR 238 PM AST SAT SEP 15 2012 PRC019-039-047-054-073-091-101-105-107-141-143-145-151930- BARRANQUITAS PR-CIALES PR-COROZAL PR-FLORIDA PR-JAYUYA PR-MANATI PR- MOROVIS PR-NARANJITO PR-OROCOVIS PR-UTUADO PR-VEGA ALTA PR- VEGA BAJA PR- 238 PM AST SAT SEP 15 2012 ...SIGNIFICANT WEATHER ADVISORY FOR STRONG THUNDERSTORMS OVER CIALES AND JAYUYA EASTWARD TO NARANJITO... AT 226 PM AST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED STRONG THUNDERSTORMS OVER JAYUYA...CIALES...MOROVIS...COROZAL...AND NARANJITO...MOVING SLOWLY TO THE NORTH. THESE STORMS WERE PRODUCING VERY HEAVY RAINFALL AND FREQUENT LIGHTNING AND MAY ALSO CONTAIN WIND GUSTS TO 45 MPH AND SMALL HAIL. JJA
COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO SERVICIO NACIONAL DE METEOROLOGIA SAN JUAN PR 238 PM AST SABADO 15 DE SEPTIEMBRE DE 2012 PRC019-039-047-054-073-091-101-105-107-141-143-145-151930- BARRANQUITAS PR-CIALES PR-COROZAL PR-FLORIDA PR-JAYUYA PR-MANATI PR-MOROVIS PR-NARANJITO PR-OROCOVIS PR-UTUADO PR-VEGA ALTA PR- VEGA BAJA PR- 238 PM AST SABADO 15 DE SEPTIEMBRE DE 2012 A LAS 2:26 PM AST...METEOROLOGOS DEL SERVICIO NACIONAL DE METEOROLOGIA DETECTARON FUERTES TRONADAS SOBRE JAYUYA...CIALES...MOROVIS...COROZAL...Y NARANJITO...MOVIENDOSE LENTAMENTE HACIA EL NORTE. ESTAS TORMENTAS ESTABAN PRODUCIENDO LLUVIAS BIEN FUERTES Y FRECUENTES RAYOS Y PUEDEN PRODUCIR RAFAGAS DE VIENTOS DE HASTA 45 MPH Y GRANIZO PEQUENO. JJA/CAM
COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO SERVICIO NACIONAL DE METEOROLOGIA SAN JUAN PR 238 PM AST SABADO 15 DE SEPTIEMBRE DE 2012 PRC019-039-047-054-073-091-101-105-107-141-143-145-151930- BARRANQUITAS PR-CIALES PR-COROZAL PR-FLORIDA PR-JAYUYA PR-MANATI PR-MOROVIS PR-NARANJITO PR-OROCOVIS PR-UTUADO PR-VEGA ALTA PR- VEGA BAJA PR- 238 PM AST SABADO 15 DE SEPTIEMBRE DE 2012 ...ADVERTENCIA POR CONDICIONES DE TIEMPO SEVERO DEBIDO A FUERTES TRONADAS SOBRE CIALES DESDE EL ESTE DE JAYUYA HASTA NARANJITO... A LAS 2:26 PM AST...METEOROLOGOS DEL SERVICIO NACIONAL DE METEOROLOGIA DETECTARON FUERTES TRONADAS SOBRE JAYUYA...CIALES...MOROVIS...COROZAL...Y NARANJITO...MOVIENDOSE LENTAMENTE HACIA EL NORTE. ESTAS TORMENTAS ESTABAN PRODUCIENDO LLUVIAS BIEN FUERTES Y FRECUENTES RAYOS Y PUEDEN PRODUCIR RAFAGAS DE VIENTOS DE HASTA 45 MPH Y GRANIZO PEQUENO. JJA/CAM
The San Juan radar (TJUA), 75 km away, was scanning. The volume nearest the first event began at 20:52 UTC.
1 flash flood. Local standard time, as filed.
Two young men were swept away by a sharp rise in the Guayanilla river in Barrio Jaguapasto. The two young men were found later dead.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flash Flood, Guayanilla | 2012-09-15 | Male | In Water | Direct | |
| Flash Flood, Guayanilla | 2012-09-15 | Male | In Water | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2012Every state in 2012This day in weather historyWarnings in Puerto Rico, September 2012
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: 414692.