An upper-level trough pattern in combination with a moist and unstable air mass combined to create favorable conditions for shower and thunderstorm activity across the area.
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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.
An upper-level trough pattern in combination with a moist and unstable air mass combined to create favorable conditions for 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 Nov 7, 9:57 PM AST, 5 minutes earlier.
Area Forecast Discussion National Weather Service San Juan PR 957 PM AST Tue Nov 7 2017 .UPDATE... TJSJ 08/00z sounding observed a subtropical jet with deep tropical moisture across the region. Under a trough pattern aloft and surface moisture convergence, environmental conditions are favorable for the development of showers and thunderstorms across the islands overnight. Most of the activity is expected to affect the U.S. Virgin Islands, and eastern Puerto Rico as well as the surrounding waters. Be especially cautious at night when it is harder to recognize the dangers of flooding. && .AVIATION... +SHRA/TSRA are expected to affect TJSJ/TIST til at least 08/04z. This activity will produce MVFR or even IFR conditions. TEMPO groups are in effect for TJSJ/TIST due to TSRA and low vis. Elsewhere -SHRA/VCSH are possible. E-SE winds at 5 to 10 knots overnight, but gusty in/near SHRA/TSRA. The winds are forecast to increase at 10 to 15 knots aft 08/13z. Environmental conds are favorable for the development of SHRA/TSRA across the region. && .MARINE... In general, mariners can expect seas and winds below 6 feet and 18 knots, respectively. However, hazardous marine conditions are expected in and near shower and thunderstorm activity, where locally higher seas and winds and frequent lightning are anticipated. && .PREV DISCUSSION... /issued 441 PM AST Tue Nov 7 2017/ SYNOPSIS...Upper level trof pattern west of the region will continue through at least Thursday to maintain instability aloft across the region. A moist southeasterly low level wind flow will also maintain good tropical moisture pooling through most of the work week. This moist and unstable environment will result in periods of showers and thunderstorm development across the islands and local waters. SHORT TERM...Rest of today through Thursday...Significant cloudiness and periods of mostly light showers continued across parts of the islands during the afternoon. Some areas did however experience brief periods of moderate to locally heavy rainfall earlier today. Isolated thunderstorms with areas of heavy rainfall were noted over the coastal waters and local passages. The overall wet weather pattern is expected to continue thru at least Thursday due to the instability aloft and good moisture convergence under the dominant southeasterly low level wind flow. Model guidance continued to suggest precipitable water content will remain near to or slightly above 2 inches for the entire forecast period. Therefore, showers and thunderstorms will remain possible across much of the local waters, USVI, and eastern PR overnight and early in the morning. Local and diurnal effects along with the instability aloft and available moisture will lead to an increase in shower and thunderstorm activity over PR during the afternoons. Any additional rainfall each day will increase the potential for urban and small stream flooding as well as mudslides in areas of steep terrain as soils remain saturated by previous days rains. LONG TERM...Friday through Wednesday...Upper level ridge is forecast to build from the south ad upper trough will fill while lifting northwards into the Atlantic. However, a broad surface trough is forecast to develop and linger over the east central Caribbean to help maintain a fairly moist east to southeast wind flow across the region. Precipitable water is however forecast to remain near 2.00 inches or slightly above through the period. Overall shower and thunderstorm development is expected each afternoon over portions of the interior, W and NW quadrant of Puerto Rico... and mainly over the west end of the U.S. Virgin Islands during the day. Isolated thunderstorm activity over the offshore Atlantic and Caribbean waters will be possible through the weekend and into early next week. AVIATION...High level cloudiness with light passing showers will continue to prevail across the local area through the forecast period. Mainly VFR conditions will prevail across most TAF sites through at least 08/12z. Low level winds will be mainly light and variable tonight. MARINE...Seas will be at 4 feet or less and east to southeast winds between 5 to 15 knots for the next couple of days. Locally higher seas and winds can be expected with the thunderstorms. There is a low risk of rip currents for most beaches overnight, through Wednesday except for Cramer park in Saint Croix where there is a moderate risk of rip currents. && .PRELIMINARY POINT TEMPS/POPS... SJU 76 85 75 86 / 60 60 50 60 STT 76 84 75 87 / 60 60 50 30 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && SHORT TERM...99 LONG TERM....99 AVIATION...
Perspectivas sobre Condiciones Peligrosas del Tiempo Servicio Nacional de Meteorologia San Juan PR 419 AM AST martes 7 de noviembre de 2017 AMZ710>745-PRZ001>013-080830- 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- 419 AM AST martes 7 de noviembre de 2017 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 probabilidad de tronadas con lluvia fuerte y rafagas de vientos esta tarde a traves de la mayor parte de Puerto Rico, Vieques y Culebra. .Inundaciones...Lluvias fuertes pudieran resultar en inundaciones urbanas y de riachuelos a traves de la mayor parte de Puerto Rico. Algunas inundaciones podrian resultar en carrteras cerradas a traves de los sectores del este de Puerto Rico. .Viento...Vientos sostenidos en exceso de 20 mph se espera a traves de algunas areas de las aguas costeras. .Corrientes marinas...Existe un riesgo moderado de corrientes marinas para la costa del Atlantico de las islas. .Dias Dos a Siete...miercoles a lunes Un patron de tiempo mas humedo con aguaceros y tronadas son posibles hasta el jueves. .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 al Servicio Nacional de Meteorologia en San Juan. AMZ715-725-VIZ001-002-080830- San Tomas, San John e Islas Adyacentes-Santa Cruz- Aguas cercanas del Atlantico y aguas costeras adyacentes del Caribe- 419 AM AST martes 7 de noviembre de 2017 Esta perspectiva sobre las condiciones del tiempo peligrosas es para Puerto Rico y las aguas costeras adyacentes del Atlantico. .Dia Uno...Hoy y esta noche .Tronadas...Existe probabilidad de tronadas con lluvia fuerte y breves rafagas de vientos a traves de la mayor parte de las islas locales. .Inundaciones...Lluvias fuertes pudieran resultar en inundaciones urbanas y de riachuelos a traves de las islas locales. .Dias Dos a Siete...miercoles a lunes Se espera un patron de tiempo mas humedo con aguaceros y tronadas mayormente entre martes y jueves. .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.
The national radar mosaic for the moment the first event began.
2 flood. Local standard time, as filed.
Marginal along Balderioty, highway 26, flooded and impassable. Numerous vehicles stranded.
Many roads in San Juan including Balderioty, Ponce de Leon flooded and impassable. Hospital flooded in Santurce.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2017Every state in 2017This day in weather historyWarnings in Puerto Rico, November 2017
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: 728489, 728490.