The combination of sea breeze convergence, intense heating, orographic lifting and upper level jet dynamics allowed for localized slow moving intense thunderstorm cells over Hatillo and Arecibo during the early evening. Localized but heavy very rainfall produced flash flooding.
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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.
The combination of sea breeze convergence, intense heating, orographic lifting and upper level jet dynamics allowed for localized slow moving intense thunderstorm cells over Hatillo and Arecibo during the early evening. Localized but heavy very rainfall produced flash flooding. Doppler radar estimated rainfall amounts of 6-8 inches for the 24 hour period ending at midnight. The nearest USGS rain gauge at Rio Camuy near Bayaney recorded 3.21 inches from 1635-2100 AST.
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 27, 2:52 PM AST, 4 hours 8 minutes earlier.
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</html>The San Juan radar (TJUA), 83 km away, was scanning. The volume nearest the first event began at 23:02 UTC.
1 flash flood. Local standard time, as filed.
Intense rainfall led to serious but localized urban flooding at Parcelas Roberto Clemente II, located between the Pajuil and Campo Alegre neighborhoods of Hatillo. Around 28 families sustained major property damage as mud laden runoff waters flooded their homes.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2009Every state in 2009This day in weather historyWarnings in Puerto Rico, November 2009
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 2026-09-30. Each event’s entry at NCEI: 203299.