Strong tropical wave combined with an upper-level low to create strong shower and thunderstorm activity across the area.
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.
Strong tropical wave combined with an upper-level low to create strong shower and thunderstorm activity across the area.
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 30, 6:11 PM AST, 49 minutes earlier.
Area Forecast Discussion...DELAYED National Weather Service San Juan PR 611 PM AST Thu Aug 30 2018 .SYNOPSIS...A TUTT lifting north northwest across the region and a tropical wave moving across the area will continue to enhance convective development the evening through Friday afternoon. As the TUTT lifts northward, a high pressure ridge will build from the east, leading to a more seasonal weather pattern of overnight streaming showers and locally and diurnally convection to the local islands by Saturday. Another tropical wave is forecast to enter the eastern Caribbean late sunday and move across the region Monday through Tuesday. This will again enhance showers and thunderstorm development across the islands and coastal waters. && .SHORT TERM...Tonight through Saturday... Considerable cloudiness spread across the region by the earlier and ongoing convection due to the interaction of the lingering Tutt and the passing tropical waves, will persist into the evening hours. Showers and enhanced thunderstorm activity should be focused mainly over portions of the east coastal areas of Puerto Rico and around the U.S. Virgin islands well into the evening hours. This activity should gradually diminishing by late evening. Until then, rainfall will continue to be locally heavy at times especially over the coastal waters and around portions of the Virgin Islands, where periods of heavy rains and frequent lightning continued with the strong thunderstorm activity. For the rest of the overnight and early morning hours, the best chance for continued shower activity will be near USVI and on the eastern third of Puerto Rico where periods of locally heavy rains is forecast. On Friday, lesser cloud coverage and more sunshine is expected across the region. This will allow better daytime heating leading to another round of enhanced afternoon convection mainly over parts of central and western Puerto Rico as well as around the San Juan metro. The potential for urban and small stream flooding as well as mudslides in areas of steep terrain will also remain high. More seasonal weather conditions expected Saturday through Sunday as the Tutt pulls away from the region and high pressure ridge builds aloft. .LONG TERM...Sunday through Thursday... High pressure ridge will continue to build from the east over the local area during the weekend, resulting in less favorable upper level dynamics for convective development over the forecast area. However, the prevailing trade winds will continue to transport patches of low level moisture into the area, promoting overnight and early morning showers streaming across the local waters into portions of the Virgin Islands and eastern Puerto Rico. This will be followed by diurnal induced afternoon convection over portions of the interior and western Puerto Rico. As surface winds become more east northeast on Sunday, convection should be focused over the southwestern quadrant of Puerto Rico. Mostly isolated afternoon convection can be expected elsewhere. By late Sunday into early next week, another surge of moisture is expected as a tropical wave is forecast to move across the forecast area by Monday into Tuesday. The increasing instability and moisture will help aid in the development of additional showers and thunderstorms through at least Tuesday. A somewhat drier air mass is expected to then spread across the local area Wednesday and Thursday except for the occasional passing early morning clouds and showers transported in the prevailing northeast wind flow. && .AVIATION...SHRA/TSRA in progress across the FA. Tops FL450-520. TSRA decreasing. Areas of IFR/MVFR and mtn obscurations til aft 31/02Z. Conds impvg ovr w half PR aftwrds. Areas of east winds FL005- 010 20-30 kt just north of PR coast, ovr SE PR and lcl gusts arnd TSRA till 30/22Z. Othw sfc winds bcmg SE 10-20 kt blo FL100. && .MARINE...Frequent lightning accompanying areas of strong thunderstorms will continue to affect parts of the local waters into the evening hours, as a tropical wave crosses the region. Choppy seas occasionally up to 8 feet are expected to continue mainly across the offshore waters and local passages overnight through Friday. && .PRELIMINARY POINT TEMPS/POPS... SJU 76 85 77 88 / 60 60 20 20 STT 79 89 79 90 / 60 40 20 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && SHORT TERM...RAM LONG TERM....DS
Perspectivas sobre Condiciones Peligrosas del Tiempo Servicio Nacional de Meteorologia San Juan PR 527 AM AST jueves 30 de agosto de 2018 AMZ710>745-PRZ001>013-310930- 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- 527 AM AST jueves 30 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...Se esperan tronadas con lluvia fuerte y vientos en rafaga breves hoy a traves de las islas locales, especialmente a traves del este de Puerto Rico a medida que una onda tropical se mueva sobre el area. .Inundaciones...Lluvias fuertes pudieran resultar en inundaciones urbanas y de riachuelos. .Vientos...Se esperan vientos sostenidos sobre 20 mph a traves de las aguas locales. .Oleaje...Se espera oleaje de hasta 7 pies a traves de las aguas mar afuera del Atlantico hasta las 8 AM AST de hoy. Oleaje picado de hasta 6 pies en el resto del area. .Corrientes marinas...Existe un riesgo moderado de corrientes marinas para las playas del norte, sureste y suroeste de Puerto Rico, al igual que para playas de Vieques y Culebra. .Dias dos a siete...viernes a miercoles Se espera que los aguaceros y tronadas asociadas a una onda tropical continuen hasta el viernes. Se espera lluvia fuerte e inundaciones el viernes. .Comunicado sobre informacion reportada por observadores... No se anticipa activacion amplia de observadores, sin embargo, se les exhorta a los observadores individuales a reportar vientos fuertes, inundaciones y corrientes marinas al Servicio Nacional de Meteorologia en San Juan. AMZ715-725-VIZ001-002-310930- San Tomas, San John e Islas Adyacentes- Santa Cruz- Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe- 527 AM AST jueves 30 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 .Tronadas...Tronadas con lluvia fuerte y rafagas de viento breves son posibles alrededor de las islas hoy. Algunas de ellas pudieran afectar tierra. .Inundaciones...Lluvias fuertes pudieran resultar en inundaciones de carreteras y de riachuelos. .Vientos...Se esperan vientos sostenidos sobre 20 mph a traves de porciones de las aguas locales. .Oleaje...Se espera oleaje vigorosos de hasta 7 pies a traves de las aguas mar afuera del Atlantico hasta las 8 AM AST hoy. Oleaje picado de hasta 6 pies para el resto del area. .Dias dos a siete...viernes a miercoles No se anticipa activacion amplia de observadores, sin embargo, se les exhorta a los observadores individuales a reportar vientos fuertes, inundaciones y corrientes marinas al Servicio Nacional de Meteorologia en San Juan. .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.
The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
Minor flooding reported along the marketplace located near Highway 104.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in U.S. Virgin Islands in 2018Every state in 2018This day in weather historyWarnings in U.S. Virgin Islands, 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: 783417.