Tropical wave combined with an upper-level low to create shower and thunderstorm across different sectors 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.
Tropical wave combined with an upper-level low to create shower and thunderstorm across different sectors 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 Aug 5, 12:02 PM AST, 3 hours 53 minutes earlier.
Area Forecast Discussion National Weather Service San Juan PR 1202 PM AST Sun Aug 5 2018 .UPDATE... Doppler radar shows scattered showers moving along the northern coast of Puerto Rico. These showers produced heavy rain over the San Juan metro area this morning, and over northwestern Puerto Rico. Moisture ahead of the axis of the wave is being enhanced by the upper level low to the north of Puerto Rico and the Upper level high to to east, these features are causing convergence. Model guidance keeps the strongest divergence aloft in the southern Caribbean waters this is where the strongest convection has remained since this morning. Currently convection has started to spread to north and possible will effect the southern portions of Puerto Rico later this afternoon. Showers and isolated thunderstorms are expected to develop over the northwest and western Puerto Rico this afternoon. Some showers and thunderstorms may cause brief heavy rainfall, therefore urban and small stream flooding, and ponding of roadways is possible across western Puerto Rico. Monday a tropical wave will move into the region and will be helped by a trough to the west of Puerto Rico. At this time there are some difference in current model guidance from the last couple of days. The GFS and EURO showed 500 mb, 250 mb heights and temperatures deceasing early this week, now the models have backed off this trend. The GFS and Euro shows ridging at 500 mb instead of a trough with the troughiness remaining well to the east of Puerto Rico. As a result high resolution models have decreased rainfall amounts over the U.S. Virgin Islands and Puerto Rico. This recent trend models have backed away from the unstable conditions that were forecasted over the last several days. Another inhibiting factor is the Saharan dust that is current across the east Atlantic and local area creating drier conditions and taking way the low level moisture need for instability. && .AVIATION...SHRA are expected across the most of the terminal sites today. Another noon convection has started to develop to the east and will continue to progress to the west. Terminals TJMZ and TJBQ could see SHRA/TSRA by 05/18Z and continuing until 05/22Z. Sfc winds out of the east at 10 to 15 kts with higher gusts. && .MARINE...Seas 4 to 6 feet with winds 10 to 20 kts are expected today. Showers and isolated thunderstorms are expected to develop across the north Atlantic and Caribbean waters today and through the overnight hours due to a tropical wave that will move into the region late tonight. && .PREV DISCUSSION... /issued 439 AM AST Sun Aug 5 2018/ SYNOPSIS...An upper-level low currently located north of Puerto Rico will continue to move westward into the southwest Atlantic through mid week. A tropical wave and its associated moisture field will move over the region late tonight through Monday. A drier and stable weather pattern is expected by Tuesday and will hold through Friday. Another tropical wave may impact the region by next Saturday. SHORT TERM...Today through Tuesday... There is Saharan dust over the local area and it will persist over the next several days. Approaching tropical wave will cause an increase in the available moisture across the local area today into Monday. There is also an upper low that is moving west just north of the local area. The combination of these two features will cause an increase in shower and thunderstorms potential across the local area depending on the positioning. At this time, satellite imagery shows areas of convection over the Caribbean just south and east of the upper low, and this area of convection is expected to move west as the upper low moves west. Having said that, there is some disagreement among the model guidance and also among the different model runs. Most of the different models, both global and high resolution, show that there will be showers and thunderstorms across Puerto Rico this afternoon while a few showers are expected elsewhere. Then for tonight, the showers and thunderstorms are forecast to remain mainly over the local waters. The only model that shows some convection over land areas tonight is the ECMWF, that has some rain across eastern PR, the rest of the models have the convection over water. In addition, the rainfall amounts and coverage has diminished over land areas for Monday, keeping the convection to portions of the northwest quadrant of Puerto Rico in the afternoon. Bottom line is that the interaction of this tropical wave and the upper low will bring an increase of shower and thunderstorm activity to the local area. The local forecast highlights the areas where the highest chance of rain is expected. For Tuesday, the tropical wave passes and drier air moves in. Rainfall activity is expected to diminish quite a bit and mainly fair weather with haze is to be expected. LONG TERM...Wednesday through Sunday... Model guidance continues to indicate that the drier than normal air mass as well as the high concentration of Saharan dust particulates will hold through Friday. Therefore, expect mainly fair weather conditions and hazy skies with very limited shower activity. The area that has the best probability of observing shower activity will be across western PR during the afternoons due to strong heating, sea breeze convergence, and topographical effects. Even these showers that do manage to develop across western PR during the afternoons are expected to be short-lived and not produce significant rainfall accumulations given the dry air mass in place. By Saturday, model guidance continues to indicate the arrival of another tropical wave. Therefore, a significant increase in shower and thunderstorm activity is possible. Given that we are still almost a week away from this solution, details on the timing and the amount of rainfall expected are uncertain. A quieter day is expected by next Sunday as the tropical wave moves away. AVIATION...SHRA activity is expected to gradually increase today. For the morning hours light VCSH can be expected across most of the local terminals. Afternoon convection is expected in the afternoon, causing VCTS at TJMZ and TJPS, possibly at TJSJ and TJBQ as well. However, TEMPO MVFR conds may be observed at TJMZ at some point between 05/17Z and 05/21Z. Winds will be from the east at 10-15KT with occasional gusts and sea breeze variations. MARINE...Seas of 3 to 5 feet with winds of 10 to 20 knots are expected across the regional waters. Therefore, due to the higher winds, small craft operators should exercise caution. By tonight, an increase in shower and thunderstorm activity is expected across the regional waters, especially the Caribbean waters, as a tropical wave approaches. A low to moderate risk of rip currents will continue across the local beaches. && .PRELIMINARY POINT TEMPS/POPS... SJU 87 77 88 77 / 30 30 20 20 STT 89 80 89 79 / 30 30 10 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && SHORT TERM...TW LONG TERM....GL
Perspectivas sobre Condiciones Peligrosas del Tiempo Servicio Nacional de Meteorologia San Juan PR 532 AM AST domingo 5 de agosto de 2018 AMZ710>745-PRZ001>013-061000- San Juan y Vecindad-Noreste-Sureste- Este Interior- Norte Central- Interior Central-Ponce y Vecindad- Noroeste- Oeste Interior-Mayaguez y Vecindad-Suroeste-Culebra- Vieques-Aguas cercanas y lejanas a la costa del Atlantico y Caribe- 532 AM AST domingo 5 de agosto de 2018 Esta perspectiva sobre las condiciones peligrosas del tiempo es para Puerto Rico y las aguas costeras adyacentes del Atlantico. .Dia Uno...Hoy y esta noche .Tronadas...Existe la posibilidad de tronadas con lluvia fuerte y vientos en rafaga breves a traves de sectores del oeste y suroeste de PR. .Inundaciones...Lluvia fuerte pudiera resultar en inundaciones urbanas y de riachuelos. .Vientos...Se esperan vientos sostenidos en exceso de 20 MPH a traves de las aguas del Caribe y las aguas costeras locales. .Olas...Se espera oleaje picado de hasta 5 pies a traves de las aguas mar afuera del del Atlantico y el Caribe asi como los pasajes locales. .Corrientes Marinas...Existe un riesgo moderado de corrientes marinas para las playas del norte y algunas del sureste y suroeste. Algunas playas de Vieques y Culebra tambien cuentan con un riesgo moderado. .Dias dos a siete...lunes a sabado La onda tropical y la baja presion en la altura que se espera se acerquen al area para hoy deben permanecer hasta el lunes. Esto continuara causando aguaceros y tronadas a traves de las aguas locales y posiblemente sobre sectores de Puerto Rico. Al menos inundaciones urbanas y de riachuelas se deben esperar con esta actividad. .Comunicado sobre informacion reportada por observadores... No se anticipa activacion amplia de observadores, sin embargo, se les exhorta a los observadores individuales a reportar inundaciones y corrientes marinas al Servicio Nacional de Meteorologia en San Juan. AMZ715-725-VIZ001-002-061000- San Tomas, San John e Islas Adyacentes- Santa Cruz- Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe- 532 AM AST domingo 5 de agosto de 2018 Esta perspectiva sobre las condiciones del tiempo peligrosas es para las Islas Virgenes Americanas y las aguas costeras adyacentes. .Dia Uno...Hoy y esta noche .Viento...Se esperan vientos sostenidos en exceso de 20 MPH a traves de las aguas locales y areas costeras. .Oleaje...Se espera oleaje picado de hasta 5 pies a traves de las aguas mar afuera del Atlantico y el Caribe asi como en los pasajes locales. .Corrientes Marinas...Existe un riesgo moderado de corrientes marinas a traves de las playas del norte y este de Santa Cruz. .Dias dos a siete...lunes a sabado La onda tropical y la baja presion en la altura que se espera se acerquen al area para hoy deben permanecer hasta el lunes. Esto continuara causando aguaceros y tronadas a traves de las aguas locales y posiblemente algunos de estos aguaceros pudieran alcanzar las Islas Virgenes Americanas. .Comunicado sobre informacion reportada por observadores... No se anticipa activacion amplia de observadores, sin embargo, se les exhorta a los observadores individuales a reportar corrientes marinas al Servicio Nacional de Meteorologia en San Juan.
Special Weather Statement National Weather Service San Juan PR 340 PM AST SUN AUG 5 2018 PRZ007-009-052045- Western Interior-Ponce and Vicinity- 340 PM AST SUN AUG 5 2018 ...A STRONG THUNDERSTORM WILL AFFECT PONCE...UTUADO AND ADJUNTAS MUNICIPALITIES... At 339 PM AST, a strong thunderstorm was located over northern Ponce and southern Adjuntas. The storm is nearly stationary over the Cordillera Central. . Winds in excess of 30 mph and pea size hail are possible with this storm. LAT...LON 1813 6674 1815 6675 1819 6671 1815 6666 TIME...MOT...LOC 1939Z 237DEG 0KT 1815 6670 Snell
Comunicado Especial de las Condiciones del Tiempo Servicio Nacional de Meteorologia San Juan PR 340 PM AST domingo 5 de agosto de 2018 PRZ007-009-052045- Oeste Interior-Ponce y Vecindad- 340 PM AST domingo 5 de agosto de 2018 ...UNA TRONADA FUERTE AFECTARA LOS MUNICIPIOS DE PONCE...UTUADO Y ADJUNTAS... A las 3:39 PM AST, una tronada fuerte estaba localizada sobre el norte de Ponce y el sur de Adjuntas. Esta tormenta estaba casi estacionara sobre la Cordillera Central. Vientos en exceso de 30 mph y granizo pequeno son posibles con esta tronada. Snell/ColonPagan
The San Juan radar (TJUA), 68 km away, was scanning. The volume nearest the first event began at 19:53 UTC.
1 hail, 1 flood. Local standard time, as filed.
Emergency managers called to report Penny Size Hail in the vicinity of Barrio Saltillo, southeast of the town.
Urban flooding reported across Calle Rexach, Calle William and Calle Martino in Barrio Obrero.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2018Every state in 2018This day in weather historyWarnings in Puerto Rico, August 2018
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: 783372, 783420.