After the previous rainfall events, soils remained saturated across the region, maintaining the risk of flooding at significant levels. A mid to upper-level trough remained close enough to the region to generate shower and thunderstorms activity.
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.
After the previous rainfall events, soils remained saturated across the region, maintaining the risk of flooding at significant levels. A mid to upper-level trough remained close enough to the region to generate shower and thunderstorms activity. Conditions gradually improved across the region, but enough instability remained, and showers and thunderstorms developed each afternoon.
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 May 11, 4:33 PM AST, 6 minutes earlier.
Area Forecast Discussion National Weather Service San Juan PR 433 PM AST Sat May 11 2024 .SYNOPSIS... A distant mid to upper-level trough will remain close enough to keep marginally unstable conditions through the rest of the weekend. With southeasterly winds and available moisture, heat indices could exceed 102 degrees Fahrenheit, potentially reaching around 108-110 degrees in localized coastal areas of northern Puerto Rico over the weekend. Lingering saharan dust will persist through at least early next week. && SHORT TERM...Tonight through Monday... Afternoon convection began after 2PM today and by this time, 4:27PM, a line of thunderstorms stretches from Utuado to Catano with up to 2 inches of rainfall detected according to radar estimates. Rainfall will continue through the rest of the afternoon into the early evening hours for these areas, however conditions should improve into the night. A distant mid-to-upper level through will remain close enough to keep marginally unstable conditions during the weekend. In the meantime, an associated upper-level jet streak (70-90 knots) will continue to spread across the northeastern Caribbean, further enabling the development of deep convection through late tonight, with 500 mbar temperatures falling to around -7 degrees. Consequently, there is a potential for thunderstorm development, as indicated by the Galvez-Davison Index. Stormy conditions are possible late tonight over the local waters, with some activity affecting Puerto Rico's eastern half, Vieques, Culebra, and the U.S. Virgin Islands. With the lingering moist airmass, strong winds aloft associated with a upper-level low northeast of the region, and a weak lower level steering flow from the south-east all combines to allow unstable weather to prevail this evening through Monday, especially during the afternoon hours. Conditions are expected to improve over the next few days however afternoon showers with isolated thunderstorms on Sunday and Monday are still likely. Wind speeds will persist at 5-15 mph from the southeast, shifting to an easterly flow on Monday. This shift will relocate the areas with the potential for the highest rainfall totals from northern sections of Puerto Rico on Sunday to western sections early next week. Temperatures may soar along the coast and urban areas into the upper 80s to mid-90s, while higher elevations could see highs in the upper 70s to mid-80s. With abundant moisture across the region, heat indices could exceed 102 degrees Fahrenheit, potentially reaching around 108-110 degrees in localized coastal areas of northern Puerto Rico over the weekend mainly during the hours between 10am and 3pm && LONG TERM...Tuesday through Saturday... /from previous discussion/ The NASA aerosol optical thickness (AOT) guidance continues to suggest lingering Saharan dust particles to start the period. Model guidance to suggest a mid- to upper-level ridge affecting the region by the start of the period, promoting more typical weather with afternoon convection due to diurnal and local effects. However, model guidance suggests an upper trough closing in on the islands from the northwest by Friday and moving across through Saturday. Precipitable water (PWAT) values are forecast to generally stay at normal values, between 1.5 to near 2.0 inches, through the workweek as patches of moisture advect into the region, Friday and Saturday look to be the wettest days with high end normal values to possibly above normal values. Light to moderate easterlies are forecast through the period as a surface high moves into the western Atlantic. Most available moisture should reach up to 850 to 800 mb for the period, with model guidance suggesting additional available moisture through the mid levels by Friday and Saturday. Limited Heat Risk (heat indices from 102 to 107 degrees Fahrenheit) or even higher, especially during the daily maximum heating, will persist across several lower elevation sectors of the islands where no significant rain is observed. This diurnal heating, local effects and sea breeze variations will continue to promote up to strong afternoon convection, steered by easterly winds and possibly enhanced by the upper through on Friday and Saturday. This will promote convective activity mainly over sectors of the interior to western half of the Puerto Rico and downwind of the local islands. Above- normal sea surface temperatures can also promote nighttime showers across windward sectors of the islands, patchy fog is also forecast for areas of the interior during the early morning hours. && .AVIATION... (18Z TAFS) SHRA/TSRA expected to develop north of Cordillera Central and near TJBQ, dissipating around 11/23Z. Periods of reduced VIS and lower ceilings expected. SHRA will increase across the Caribbean waters and near the USVI terminals after 00Z. Winds are light, out of the SW at 5-7 kts, switching from the SE around 06z. After 12Z, speeds will pick up to 9-11 kts. SHRA/TSRA will develop again after 12/17Z for NW PR, impacting TJBQ. && .MARINE... A surface high pressure across the central Atlantic and a building low in the western Atlantic will allow southeasterly winds to prevail through the weekend. A weak northerly swell will continue to fade across the Atlantic waters and passages. Strong showers and thunderstorms over the waters can result in locally higher seas and gusty winds. && .SJU WATCHES/WARNINGS/ADVISORIES... PR...None. VI...None. AM...None. && CAM/MMC/RC
Hazardous Weather Outlook National Weather Service San Juan PR 448 AM AST Sat May 11 2024 AMZ711>745-PRZ001>013-121000- 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- 448 AM AST Sat May 11 2024 This Hazardous Weather Outlook is for portions of Puerto Rico. .DAY ONE...Today and Tonight .Lightning...Isolated thunderstorms are possible, mainly across central to northern Puerto Rico in the afternoon and eastern Puerto Rico, Vieques, and Culebra tonight. Be aware of thunderstorms in your area and be prepared to take shelter. .Excessive Rainfall...Flooding of urban areas, roads, and small streams. Since soils remain saturated, life-threatening flash flooding and mudslides, possibly entering structures and cutting off neighborhoods. Some rivers may exceed flood stage, affecting nearby roads and structures. .Excessive Heat...Heat index of 102-107 degrees across most coastal areas, including Vieques and Culebra. Localized heat index exceeding 108 degrees are possible, mainly across northern Puerto Rico and other urban areas. Heat exhaustion possible with prolonged exposure. .DAYS TWO THROUGH SEVEN...Sunday through Friday The excessive rainfall and lightning hazards risk will persist each day, particularly from the typical afternoon showers and isolated thunderstorm development. With high moisture levels, heat indices could surpass 102 degrees Fahrenheit each day, with the potential for 108-110 degrees in localized areas on Sunday. A moderate rip current risk is likely on Tuesday and Friday. .SPOTTER INFORMATION STATEMENT... Spotter activation is encouraged. Please relay any information about flooding, winds, waves, and rip currents to the National Weather Service in San Juan. AMZ716-726-VIZ001-002-121000- St. Thomas St. John adjacent Islands-St Croix- Nearshore Atlantic and adjacent Caribbean Coastal Waters- 448 AM AST Sat May 11 2024 This Hazardous Weather Outlook is for portions of USVI. .DAY ONE...Today and Tonight .Lightning...Isolated thunderstorms are possible tonight. Be aware of thunderstorms in your area and be prepared to take shelter. .Excessive Rainfall...Ponding of water in roads and poorly drained areas. Urban and small stream flooding is possible. .Excessive Heat...Heat index 102-107 degrees. Heat exhaustion possible with prolonged exposure. .DAYS TWO THROUGH SEVEN...Sunday through Friday With high moisture levels, heat indices could surpass 102 degrees Fahrenheit each day. A moderate rip current risk is likely from Tuesday onward, mainly for Saint Croix. .SPOTTER INFORMATION STATEMENT... Spotter activation is encouraged. Please relay any information about flooding, winds, waves, and rip currents to the National Weather Service in San Juan.
Special Weather Statement
National Weather Service San Juan PR
406 PM AST Sat May 11 2024
PRZ001-005-006-009-112100-
San Juan and Vicinity PR-North Central PR-Central Interior PR-
Western Interior PR-
406 PM AST Sat May 11 2024
...A LINE OF STRONG THUNDERSTORM WILL IMPACT THE MUNICIPALITIES FROM
UTUADO TO SAN JUAN THROUGH 500 PM AST...
At 402 PM AST, Doppler radar was tracking a line with strong
thunderstorms capable of producing strong gusty winds, and downpours
over the interior municipalities from Utuado to the northern
municipalities near San Juan, moving northeast at 10 mph. Sudden
waterspout are possible across the coastal areas of the northern
municipalities.
HAZARD...Waterspouts and wind gusts up to 40 mph.
SOURCE...Radar indicated.
IMPACT...Waterspouts can easily overturn boats and create locally
hazardous waters. Gusty winds could knock down tree limbs
and blow around unsecured objects.
Locations impacted include...
San Juan, Sabana Seca, Catano, Toa Baja, Vega Alta, Ciales, Morovis,
Florida, Toa Alta, Manati, Vega Baja, Barceloneta, Dorado, Corozal,
Guaynabo, Ceiba, Miranda, Pajonal, San Jose, and Galateo.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
office in San Juan.
&&
LAT...LON 1846 6622 1847 6619 1845 6618 1847 6614
1844 6612 1846 6611 1847 6612 1846 6609
1845 6611 1845 6609 1840 6612 1824 6664
1850 6664 1847 6645 1850 6640
TIME...MOT...LOC 2002Z 204DEG 7KT 1836 6652
WATERSPOUT...POSSIBLE
MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH
CAMComunicado Especial sobre las Condiciones del Tiempo Servicio Nacional de Meteorologa San Juan PR 406 PM AST sbado 11 de mayo de 2024 PRZ001-005-006-009-112100- San Juan y Vecindad PR-Norte Central PR-Interior Central PR- Oeste Interior PR- 406 PM AST sbado 11 de mayo de 2024 ...UNA LNEA DE TORMENTAS ELCTRICAS FUERTES IMPACTAR LOS MUNICIPIOS DESDE UTUADO HASTA SAN JUAN HASTA 500 PM AST... A las 402 PM AST, el radar Doppler estaba rastreando una lnea con tormentas elctricas fuertes capaces de producir rfagas de vientos fuertes, y aguaceros sobre los municipios del interior desde Utuado hasta los municipios del norte cerca de San Juan, movindose al noreste a 10 mph. Las trombas marinas repentinas son posibles a travs de las reas costeras de los municipios del norte. PELIGRO...Trombas marinas y rfagas de viento de hasta 40 mph. FUENTE...Indicado por radar. IMPACTO...Las trombas marinas pueden volcar fcilmente los barcos y crear aguas localmente peligrosas. Los vientos rfagas podran derribar ramas de rboles y volar alrededor de objetos no asegurados. MEDIDAS DE PRECAUCIN/PREPARACIN... Si est al aire libre, considere buscar refugio dentro de un edificio. Para informar condiciones meteorolgicas severas, comunquese con su agencia policial ms cercana. Ellos transmitirn su informe a la oficina del Servicio Nacional de Meteorologa en San Juan. TROMBA MARINA...POSIBLE TAMAO DE GRANIZO MXIMO...0.00 EN RFAGA DE VIENTO MXIMO...40 MPH CAM/MMC
The San Juan radar (TJUA), 38 km away, was scanning. The volume nearest the first event began at 20:39 UTC.
3 flood, 1 flash flood, 1 thunderstorm wind. Local standard time, as filed.
Calle Acuamarina was reported as flooded.
Flooding was reported around American Gasoline, PR-459 and PR-467.
Flooding was affecting PR-459 near Universidad Interamericana de Puerto Rico. A few cars were reported as stranded.
Calle M, near a gas station, was being affected by flooding.
Two cars were impacted by a branch that fell from a tree in front of Cobian Plaza, Ave. Ponce de Leon.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2024Every state in 2024This day in weather historyWarnings in Puerto Rico, May 2024
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: 1185029, 1185030, 1185031, 1185032, 1185033.