Bands of showers and thunderstorms associated with a tropical wave moved across the local island and produced heavy showers and strong thunderstorms across Cabo Rojo and Mayaguez.
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.
Bands of showers and thunderstorms associated with a tropical wave moved across the local island and produced heavy showers and strong thunderstorms across Cabo Rojo and Mayaguez.
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 Jul 31, 11:45 AM AST, 1 hour 45 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1145 AM AST THU JUL 31 2008 .UPDATE...MADE CHANGES TO GRIDS INCREASING POPS ACROSS LOCAL AREA. THE LEADING EDGE OF A TROPICAL WAVE HAS BEGUN TO MOVE ACROSS THE COASTAL WATERS. THIS AREA OF MOISTURE WILL CONTINUE TO PROPAGATE WESTWARD AFFECTING MUCH OF THE FA LATE THIS AFTERNOON AND CONTINUING THROUGH FRIDAY. 12Z TJSJ SOUNDING SHOWED EASTERLY WINDS UP TO 650 MB. WINDS ARE GENERALLY BETWEEN 15-25KT. ACROSS THE COASTAL WATERS...SMALL CRAFT NO OTHER SIGNIFICANT CHANGES WERE MADE TO FORECAST REASONING. && .AVIATION..WINDS WILL BE FROM THE EAST NORTHEAST AT 10 TO 20 MPH...WITH GUSTS UP TO 30 KNOTS POSSIBLE NEAR THUNDERSTORMS. TJSJ AND TJBQ SHOULD SEE VFR AS THE PREVAILING CONDITIONS... HOWEVER...TJPS MAY SEE MVFR AND EVEN BRIEFLY IFR BETWEEN 18Z TO 22Z AS SHOWERS AND THUNDERSTORMS DEVELOP ACROSS CENTRAL PUERTO RICO AND THEN MOVE SOUTHWESTWARD TOWARD THE SOUTH AND SOUTHWESTERN COASTAL AREAS OF PUERTO RICO. && .PREV DISCUSSION... /ISSUED 526 AM AST THU JUL 31 2008/ SYNOPSIS...A 1024 MB SURFACE HIGH PRESSURE ACROSS THE EAST CENTRAL ATLANTIC NEAR 36 NORTH 35 WEST...EARLY THIS MORNING...WILL CONTINUE TO EXTEND SOUTHWEST ACROSS THE BAHAMAS ISLANDS THROUGH AT LEAST TOMORROW...PRODUCING A MODERATE TO FRESH TRADE WIND FLOW ACROSS THE REGIONAL WATERS. A TROPICAL WAVE ACROSS THE EASTERN CARIBBEAN EARLY THIS MORNING...WILL MOVE ACROSS THE LOCAL REGIONAL WATERS TODAY THROUGH FRIDAY...PRODUCING AN INCREASE IN CLOUDINESS...SHOWERS...WINDS AND THUNDERSTORMS. DISCUSSION...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WERE DETECTED OVERNIGHT AND EARLY IN THE MORNING MAINLY ACROSS THE CARIBBEAN WATERS AND ACROSS THE EASTERN SECTIONS OF PUERTO RICO INCLUDING THE U.S. VIRGIN ISLANDS...VIEQUES AND CULEBRA. THIS ACTIVITY WAS ASSOCIATED WITH THE LEADING EDGE OF A TROPICAL WAVE ACROSS THE EASTERN CARIBBEAN EARLY THIS MORNING. LATEST GFS MODEL RUN INDICATED THAT THE BULK OF MOISTURE ASSOCIATED WITH THIS WAVE...WILL MOVE ACROSS THE CARIBBEAN COASTAL WATERS BY 18Z TODAY WITH MODERATE MOISTURE ACROSS THE LOCAL ISLANDS. A SECOND PULSE OF MOISTURE WILL CROSS THE FA ON FRIDAY. THE NAM MODEL GUIDANCE SUGGEST THAT THE BULK OF MOISTURE WILL MOVE ACROSS THE FA STARTING AT 15Z FRIDAY AND LASTING AT LEAST UNTIL SATURDAY. ANYWAY...BOTH MODELS SUGGEST A WET AND UNSTABLE WEATHER PATTERN ACROSS THE REGION UNTIL AT LEAST SATURDAY. AN INCREASE IN WINDS ESPECIALLY ACROSS THE CARIBBEAN WATERS IS ALSO EXPECTED AS THE TROPICAL WAVE MOVES WESTWARD ACROSS THE REGION TODAY AND TOMORROW. AVIATION...A TROPICAL WAVE WILL BE MOVING INTO THE LOCAL AREA AND HAS ALREADY SPREAD SCATTERED SHOWERS ACROSS TKPK DURING THE EARLY MORNING HOUR. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO SPREAD WESTWARD DURING THE NEXT 24 TO 36 HOURS WITH SPOTTY MVFR CONDITIONS DUE TO LOWER CEILINGS AND LOCALLY REDUCED VISIBILITIES IN HEAVY RAIN. PUERTO RICO WILL EXPERIENCE SOME MOUNTAIN OBSCURATIONS POSSIBLY BEGINNING AT AROUND 16Z AND CONTINUING THROUGH THE LATE AFTERNOON HOURS. WINDS WILL BE FROM THE EAST NORTHEAST AT 10 TO 20 MPH...WITH GUSTS UP TO 30 KNOTS POSSIBLE NEAR THUNDERSTORMS. TJSJ AND TJBQ SHOULD SEE VFR AS THE PREVAILING CONDITIONS... HOWEVER...TJPS MAY SEE MVFR AND EVEN BRIEFLY IFR BETWEEN 18Z TO 22Z AS SHOWERS AND THUNDERSTORMS DEVELOP ACROSS CENTRAL PUERTO RICO AND THEN MOVE SOUTHWESTWARD TOWARD THE SOUTH AND SOUTHWESTERN COASTAL AREAS OF PUERTO RICO. MARINE...WINDS ARE EXPECTED TO INCREASE AS THE TROPICAL WAVE LOCATED ACROSS THE EASTERN CARIBBEAN EARLY THIS MORNING...MOVES OVER OUR LOCAL REGIONAL WATERS TODAY AND TOMORROW. THEREFORE EXPECT AN INCREASE ON WAVE HEIGHTS ACROSS THE CARIBBEAN AND ATLANTIC WATERS. TODAY THROUGH LATE FRIDAY...MARINERS SHOULD EXPECT SHOWERS AND THUNDERSTORMS IN THE FORM OF SQUALLS MAINLY ACROSS THE CARIBBEAN WATERS. && .PRELIMINARY POINT TEMPS/POPS... SJU 87 76 88 77 / 40 50 50 40 STT 86 76 87 77 / 50 50 50 40 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && 71/10/
HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS NATIONAL WEATHER SERVICE SAN JUAN PR 654 AM AST THU JUL 31 2008 AMZ710>750-PRZ001>013-011100- 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- 654 AM AST THU JUL 31 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT A TROPICAL WAVE CURRENTLY MOVING ACROSS THE WINDWARD ISLANDS...IS EXPECTED TO ARRIVE TO THE LOCAL AREA BETWEEN LATE THIS AFTERNOON AND EARLY FRIDAY. HOWEVER...THE FIRST BANDS OF MOISTURE ASSOCIATED TO THE WAVE HAVE ALREADY ENTERED TO THE LOCAL EASTERN CARIBBEAN WATERS. LATEST SATELLITE IMAGES ARE SHOWING MODERATE TO HEAVY SHOWER ACTIVITY AND ISOLATED THUNDERSTORMS JUST SOUTH OF SAINT CROIX. THIS ACTIVE WEATHER IS ANTICIPATED TO MOVE WESTWARD AS THE DAY PROGRESSES AND MAINLY AFFECT THE CARIBBEAN WATERS. ALTHOUGH...BRIEF PERIOD OF HEAVY SHOWERS AND SQUALLS MAY AFFECT PARTS OF THE LOCAL ISLANDS TODAY. THE SOUTH AND SOUTHWESTERN SECTIONS OF PUERTO RICO ARE ANTICIPATED TO EXPERIENCE THE WORST WEATHER CONDITIONS THIS AFTERNOON AS LOCAL ISLAND EFFECTS INTERACT WITH ABUNDANT LOW LEVEL MOISTURE AND UNSTABLE LOW TO MID LEVEL ATMOSPHERE. THIS MAY LEAD TO MINOR FLOODING ACROSS ROADWAYS...UNDERPASSES...LOW LYING AND POOR DRAINAGE AREAS AS WELL AS SMALL STREAMS AND URBAN AREAS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY SAME TROPICAL WAVE ABOVE MENTIONED...WILL LINGER AROUND THROUGH EARLY SATURDAY...WITH A SECOND ROUND OF MOISTURE ARRIVING TO THE LOCAL AREA OVERNIGHT (EARLY FRIDAY MORNING). EXPECT GOOD ACTIVITY OF SHOWERS AND THUNDERSTORMS ACROSS PUERTO RICO ON FRIDAY AFTERNOON...LASTING THROUGH THE EVENING HOURS...WHILE LITTLE BY LITTLE...THIS ACTIVITY MOVES AWAY FROM THE FORECAST AREA BY SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED. AMZ720-730-VIZ001-002-011100- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 654 AM AST THU JUL 31 2008 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT A TROPICAL WAVE CURRENTLY MOVING ACROSS THE WINDWARD ISLANDS...IS EXPECTED TO ARRIVE TO THE LOCAL AREA BETWEEN LATE THIS AFTERNOON AND EARLY FRIDAY. HOWEVER...THE FIRST BANDS OF MOISTURE ASSOCIATED TO THE WAVE HAVE ALREADY ENTERED TO THE LOCAL EASTERN CARIBBEAN WATERS. LATEST SATELLITE IMAGES ARE SHOWING MODERATE TO HEAVY SHOWER ACTIVITY AND ISOLATED THUNDERSTORMS JUST SOUTH OF SAINT CROIX. THIS ACTIVE WEATHER IS ANTICIPATED TO MOVE WESTWARD AS THE DAY PROGRESSES AND MAINLY AFFECT THE CARIBBEAN WATERS. ALTHOUGH...BRIEF PERIOD OF HEAVY SHOWERS AND SQUALLS MAY AFFECT PARTS OF THE LOCAL ISLANDS TODAY. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY SAME TROPICAL WAVE ABOVE MENTIONED...WILL LINGER AROUND THROUGH EARLY SATURDAY...WITH A SECOND ROUND OF MOISTURE ARRIVING TO THE LOCAL AREA OVERNIGHT (EARLY FRIDAY MORNING). EXPECT GOOD ACTIVITY OF SHOWERS AND THUNDERSTORMS ACROSS SECTIONS OF THE ISLANDS ON FRIDAY AFTERNOON...LASTING THROUGH THE EVENING HOURS...WHILE LITTLE BY LITTLE...THIS ACTIVITY MOVES AWAY FROM THE FORECAST AREA BY SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED.
PRC001-023-059-067-093-097-111-113-121-125-153-311815-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
1255 PM AST THU JUL 31 2008
THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A SPECIAL WEATHER
STATEMENT EFFECTIVE UNTIL 215 PM AST FOR PEOPLE IN THE FOLLOWING
MUNICIPALITIES
IN PUERTO RICO
HORMIGUEROS...ADJUNTAS...MARICAO...SABANA GRANDE...SAN GERMAN...
YAUCO...GUAYANILLA...PONCE...CABO ROJO...MAYAGUEZ AND PENUELAS
AT 1250 PM AST DOPPLER RADAR INDICATED SEVERAL LINES OF SHOWERS AND
STRONG THUNDERSTORMS MOVING WESTWARD TOWARDS OR ACROSS THESE AREAS.
THESE SHOWERS AND THUNDERSTORMS MAY CAUSE SOME FLOODING ACROSS
ROADWAYS...UNDERPASSES...LOW LYING AND POOR DRAINAGE AREAS.
LOCALIZED BRIEF PERIODS OF HEAVY RAINFALL...GUSTY WINDS UP TO 35 MPH
...HAIL AND CLOUD TO GROUND LIGHTNING CAN ALSO BE EXPECTED WITH
THESE THUNDERSTORMS.
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.
AAS/FCPRC001-023-059-067-093-097-111-113-121-125-153-311815-
COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO
SERVICIO NACIONAL DE METEOROLOGIA SAN JUAN PR
1255 PM AST JUEVES 31 DE JULIO DE 2008
EL SERVICIO NACIONAL DE METEOROLOGIA EN SAN JUAN HA EMITIDO UN
COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO EN EFECTO HASTA
LAS 2:15 PM AST PARA LAS PERSONAS EN LOS SIGUIENTES MUNICIPIOS EN
PUERTO RICO
HORMIGUEROS...ADJUNTAS...MARICAO...SABANA GRANDE...SAN
GERMAN...YAUCO...GUAYANILLA...PONCE...CABO ROJO...MAYAGUEZ Y PENUELAS
A LAS 12:50 PM AST...EL RADAR DOPPLER INDICO VARIAS LINEAS DE
AGUACEROS Y FUERTES TRONADAS MOVIENDOSE HACIA EL OESTE A TRAVES DE
ESTAS AREAS.
ESTOS AGUACEROS Y TRONADAS PODRIAN CAUSAR ALGUNAS INUNDACIONES A
TRAVES DE CARRETERAS...PUENTES...AREAS BAJAS Y DE POCO DRENAJE.
BREVES PERIODOS DE LLUVIA LOCALIZADA...RAFAGAS DE VIENTO DE HASTA 35
MPH...GRANIZO Y RELAMPAGOS DE NUBE A TIERRA TAMBIEM SE ESPERAN
DEBIDO ESTAS TRONADAS.
EL EXTERIOR...MANTENGASE ALEJADO DE OBJETOS ALTOS AISLADOS COMO
ARBOLES. MUEVASE AL INTERIOR DE UN EDIFICIO SI ES POSIBLE. CUANDO SE
ENCUENTRE EN EL INTERIOR...MANTENGASE ALEJADO DE VENTANAS Y PUERTAS
Y EVITE UTILIZAR TELEFONOS...SOLO UTILICELOS EN CASO DE EMERGENCIA.
INTENTE DESCONECTAR ENSERES ELECTRICOS INNECESARIOS ANTES DE QUE SE
ACERQUE LA TRONADA.
AAS/FCThe San Juan radar (TJUA), 114 km away, was scanning. The volume nearest the first event began at 17:29 UTC.
1 flood, 1 flash flood, 1 heavy rain. Local standard time, as filed.
A trained spotter reported highway 102 flooded near la Bajura sector.
A trained spotter reported highway 114 between Mayaguez and Cabo Rojo impassable. One car was carried off the road in the current but the occupants were reported safe.
A trained spotter reported downed trees on highway 108 between the municipalities of Mayaguez and Cabo Rojo.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2008Every state in 2008This day in weather historyWarnings in Puerto Rico, July 2008
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: 124004, 123987, 123990.