A broad upper level low pressure was located over the west central Atlantic with a trough that extended southwest across the Northeast Caribbean. The proximity of this trough enhanced low level wind convergence, leading to the development of strong thunderstorms across north central of Puerto Rico.
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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.
A broad upper level low pressure was located over the west central Atlantic with a trough that extended southwest across the Northeast Caribbean. The proximity of this trough enhanced low level wind convergence, leading to the development of strong thunderstorms across north central of Puerto Rico. These thunderstorms produced gusty winds and pea size hail in Vega Baja and between Corozal and Morovis.
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 27, 5:03 AM AST, 9 hours 59 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 503 AM AST FRI JUL 27 2007 .SYNOPSIS...SURFACE HIGH PRESSURE SYSTEM ACROSS THE NORTH CENTRAL ATLANTIC...EXTENDS SOUTHWESTWARD TO THE BAHAMAS AND CONTINUED TO SHIFT SLOWLY SOUTHEAST. THE HIGH AND ASSOCIATED RIDGE WILL CONTINUE TO DOMINATE THE CENTRAL ATLANTIC AND NORTHEAST CARIBBEAN THROUGH THE END OF WEEK...WHILE SLOWLY WEAKENING. A WEAK LOW LEVEL DISTURBANCE WILL MOVE ACROSS THE LOCAL AREA THIS MORNING... AND BRING A SLIGHT INCREASE IN SHOWERS. && .DISCUSSION...LIGHTER WINDS WERE MEASURED AND A RELATIVELY DRY LOCAL AIRMASS WAS MEASURED BY 00Z SOUNDING IN TJSJ AND MACM. 3.9U SATELLITE IMAGERY SHOWED PATCHY CLOUDS WITH MAINLY ISOLATED MODERATE SHOWERS ASSOCIATED. THE HIGH PRESSURE SYSTEM IN THE NORTH CENTRAL ATLANTIC HAS WEAKEN AND MOVED SOUTHEAST SLOWLY RESULTING IN WEAKER WINDS LOCALLY. THIS WILL RESULT IN ENHANCED LOW LEVEL CONVERGENCE OF THE WINDS THIS AFTERNOON LEADING TO THE DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS. THE STEERING FLOW FROM THE SOUTHEAST MAY ALSO FAVOR THUNDERSTORM ACTIVITY IN THE VICINITY OF THE SAN JUAN METRO AREA. SAL ANALYSIS SHOWED SAHARAN DUST REMAINING OVER THE LOCAL AREA. THIS WILL RESULT IN HAZY SKIES TODAY AND PROBABLY SATURDAY. THE GFS MODEL GUIDANCE ADVERTISES ANOTHER TROPICAL WAVE APPROACHING THE LOCAL AREA EARLY ON MONDAY. THIS TROPICAL WAVE IS EXPECTED TO RESULT IN AN INCREASE IN THE LOCAL MOISTURE AND ENHANCED CHANCES FOR THE OCCURRENCE OF PRECIPITATION. && .MARINE...WINDS HAVE SUBSIDED ACROSS THE ATLANTIC AND CARIBBEAN COASTAL WATERS AND THERE ARE NO PRECAUTIONARY STATEMENTS IN EFFECT FOR ANY OF THE COASTAL WATERS. && .CLIMATE...THE LOCAL AREA IS LOCATED IN GEOGRAPHIC POSITION WHERE THE CHANCES FOR TROPICAL CYCLONE DEVELOPMENT UPSTREAM OF THE ISLANDS INCREASES DURING THE MONTHS OF AUGUST AND SEPTEMBER AND OCTOBER. && .PRELIMINARY POINT TEMPS/POPS... SJU 90 78 91 78 / 0 0 20 20 STT 87 79 87 79 / 20 20 20 40 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && 37/11
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 600 AM AST FRI JUL 27 2007 PRZ001>013-AMZ710>750-281000- 600 AM AST FRI JUL 27 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO. .TODAY AND TONIGHT...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON OVER THE CENTRAL AND WEST INTERIOR AND WILL GENERALLY MOVE TOWARD THE WEST NORTHWEST AT 10 MPH. ISOLATED THUNDERSTORMS OVER THE INTERIOR COULD PRODUCE BRIEF PERIODS OF LOCALLY HEAVY RAINFALL...FREQUENT CLOUD TO GROUND LIGHTNING STRIKES AND MINOR FLOODING ACROSS POOR DRAINAGE AND LOW LYING AREAS. OTHERWISE...NO OTHER HAZARDOUS WEATHER IS EXPECTED FOR THIS PERIOD. .DAYS TWO THROUGH SEVEN...SCATTERED AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS EACH DAY. LOCALIZED HEAVY RAINFALL OVER THE INTERIOR AND WEST. NO OTHER HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED TODAY. VIZ001-002-AMZ710>730-281000- 600 AM AST FRI JUL 27 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS. .TODAY AND TONIGHT...ISOLATED MODERATE SHOWERS DEVELOPING OFF THE WEST COAST OF THE ISLANDS THIS AFTERNOON. NO OTHER HAZARDOUS WEATHER IS EXPECTED FOR THIS PERIOD. .DAYS TWO THROUGH SEVEN...ISOLATED MODERATE SHOWERS MOVING ACROSS THE LOCAL WATERS AT NIGHT AND TYPICAL RAIN BANDS DEVELOPING OFF THE WEST COASTS OF THE ISLANDS EACH MORNING AND AFTERNOON. NO OTHER HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER CALL TO ACTION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED TODAY. STAY TUNED TO NOAA WEATHER RADIO AND OTHER LOCAL MEDIA FOR FURTHER DETAILS OR UPDATES. 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 FROM YOUR PDA/PHONE: HTTP://MOBILE.SRH.NOAA.GOV OR WWW.SRH.NOAA.GOV/WML
PRC027-039-054-081-101-131-271945-
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN JUAN PR
241 PM AST FRI JUL 27 2007
THE NATIONAL WEATHER SERVICE IN SAN JUAN HAS ISSUED A SPECIAL WEATHER
STATEMENT EFFECTIVE UNTIL 345 PM AST FOR PEOPLE IN THE FOLLOWING
MUNICIPALITIES
IN PUERTO RICO
CIALES...FLORIDA...MOROVIS...SAN SEBASTIAN...LARES AND CAMUY
AT 239 PM AST THE DOPPLER WEATHER RADAR AND LOCAL SPOTTER INDICATED
STRONG THUNDERSTORMS DEVELOPING ACROSS THESE MUNICIPALITIES. THE
STRONGEST STORMS WERE BETWEEN CIALES AND MOROVIS...AND BETWEEN
LARES SAN SEBASTIAN AND MOCA. THESE STORMS WERE SLOWLY DRIFTING
NORTHWEST.
THE ACCOMPANYING HEAVY RAINS MAY FLOOD LOW LYING AREAS SUCH AS
DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED
ROADS AS THEY MAY BE WASHED OUT. WATER LEVELS OF SMALL STREAMS AND
RIVERS MAY ALSO QUICKLY RISE...THEREFORE SEEK HIGHER GROUND IF
THREATENED BY FLOOD WATERS.
INTENSE LIGHTNING IS REPORTED WITH THESE STORMS. 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. PEA SIZE
HAIL IS ALSO POSSIBLE WITH SOME OF THESE STORMS.
RAMPRC027-039-054-081-101-131-271945- COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO SERVICIO NACIONAL DE METEOROLOGIA SAN JUAN PR 241 PM AST VIERNES 27 DE JULIO DE 2007 EL SERVICIO NACIONAL DE METEOROLOGIA EN SAN JUAN HA EMITIDO UN COMUNICADO ESPECIAL SOBRE LAS CONDICIONES DEL TIEMPO HASTA LAS 345 PM AST PARA LAS PERSONAS EN LOS SIGUIENTES MUNICIPIOS EN PUERTO RICO CIALES...FLORIDA...MOROVIS...SAN SEBASTIAN...LARES Y CAMUY A LAS 239 PM AST EL RADAR DOPPLER Y OBSERVADORES DEL TIEMPO INDICARON FUERTES TRONADAS DESARROLLANDOSE A TRAVES DE ESTOS MUNICIPIOS. LAS TRONADAS MAS FUERTES ESTABAN ENTRE CIALES Y MOROVIS...Y ENTRE LARES...SAN SEBASTIAN Y MOCA. ESTAS TRONADAS SE MOVIAN LENTAMENTE AL NOROESTE. LAS LLUVIAS FUERTES PUEDEN INUNDAR AREAS COMO PUENTES Y AREAS BAJAS. EVITE ESTAS AREAS Y NO CRUZE CARRETERAS INUNDADAS. LOS NIVELES DE LOS RIOS Y QUEBRADAS PUEDEN SUBIR RAPIDAMENTE...POR LO TANTO MUEVASE A TERRENO MAS ALTO SI ES AMENAZADO POR INUNDACIONES. RELAMPAGOS INTENSOS HAN SIDO REPORTADOS CON ESTAS TRONADAS. SI ESTA AFUERA...MANTENGASE ALEJADO DE OBJETOS ALTOS COMO LOS ARBOLES. MUEVASE ADENTRO SI ES POSIBLE. CUANDO ESTE ADENTRO...ALEJESE DE LAS VENTANAS Y PUERTAS Y EVITE UTILIZAR EL TELEFONO SI ES UNA EMERGENCIA. GRANIZO PEQUENO ES POSIBLE EN ALGUNAS DE ESTAS TRONADAS.
The San Juan radar (TJUA), 49 km away, was scanning. The volume nearest the first event began at 18:59 UTC.
1 thunderstorm wind. Local standard time, as filed.
Gusty winds, pea size hail, and knocked down small trees were reported in Vega Baja.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2007Every state in 2007This day in weather historyWarnings in Puerto Rico, July 2007
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: 51440.