An upper level trough was located across the Mona Passage and this allowed for isolated to scattered showers and thunderstorms to produce locally heavy rain over the San Juan Metropolitan 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 was located across the Mona Passage and this allowed for isolated to scattered showers and thunderstorms to produce locally heavy rain over the San Juan Metropolitan 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 5, 10:19 AM AST, 3 hours 23 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1019 AM AST WED AUG 5 2009 .UPDATE...NO CHANGES TO FORECAST PACKAGE AT THIS TIME. PREVIOUS SHIFT HAD A GOOD HANDLE ON ONGOING WEATHER CONDITIONS. && .AVIATION...VFR CONDITIONS WILL PREVAIL ACROSS ALL TAF SITES THROUGH THE REST OF THE MORNING HOURS. HOWEVER...MVFR CIGS AT JMZ WITH VCTS ARE EXPECTED THIS AFTERNOON FROM 17Z TO 23Z. ELSEWHERE SOME PASSING SHOWERS ARE POSSIBLE. && .PREV DISCUSSION... /ISSUED 417 AM AST WED AUG 5 2009/ SYNOPSIS...A TUTT WITH AXIS ACROSS THE MONA PASSAGE IS TO EVOLVE INTO A CLOSED LOW OVER HISPANIOLA BY THU. MEANWHILE...TROPICAL WAVE ALONG 55W TO MOVE ACROSS THE ISLANDS ON THU. STRONG SUBTROPICAL RIDGE TO BUILD SW INTO THE ERN CARIBBEAN FOR THE WEEKEND. DISCUSSION...LOCAL AREA WILL BE ON THE EAST SIDE OF TUTT AXIS THIS AFTERNOON WHICH TYPICALLY IS A FAVORABLE PLACE OF CONVECTION. HOWEVER...MOISTURE REMAINS MODEST AT BEST WITH PWAT VALUES AROUND 1.65 INCHES. WHILE THERE WILL STILL BE CONVECTION ON THE WEST THIS AFTERNOON WIDESPREAD EXCESSIVE AMTS ARE NOT EXPECTED. TROPICAL WAVE ALONG 55W IS FCST TO CROSS THE AREA ON THU. ALTHOUGH NO DEEP CONVECTIVE ACTIVITY IS ASSOCIATED WITH THIS WAVE AT THE MOMENT WAVE IS LIKELY TO GET MORE ACTIVE AS IT APPROACHES PR/USVI AS IT BEGINS TO INTERACT WITH EAST SIDE OF TUTT LOW FCST TO EVOLVE ACROSS HISPANIOLA. ALTHOUGH AN INCREASE IN CONVECTIVE CONVERAGE IS ANTICIPATED WITH THIS WAVE VERTICAL SHEAR WILL REMAIN TOO STRONG ACROSS THE ERN CARIBBEAN PROHIBITIVE OF TC FORMATION. BEHIND THE WAVE A WIND SURGE WILL FOLLOW WITH HAZE AND DUST LIKELY FOR THE WEEKEND. STRONG MID-UPPER LVL RIDGING WILL BUILD ACROSS THE ERN CARIBBEAN FOR FRI AND SAT LIKELY PUTTING A LID ON CONVECTION. WAS TEMPTED TO LOWER POPS FOR FRI AND SAT AS AIR MASS LOOKS BONE DRY. IN ANY CASE...EXCELLENT BEACH WX EXPECTED FOR THE WEEKEND. REST OF THE TROPICAL ATLC REMAINS QUIET WITH NO THREAT AREAS TO DISCUSS. AVIATION...MVFR CIGS AT JMZ WITH VCTS. REST OF THE TAF SITES SHOULD REMAIN VFR WITH ONLY VCSH AT BEST. GREATER SHRA/TSRA CVRG IS EXPECTED FOR THU AS TROPICAL WAVE INTERACTS WITH A TROUGH TO THE WEST. MARINE...SEAS REMAIN AROUND 6 FT ACROSS AMZ710. WINDS INCREASE THU NIGHT BEHIND TROPICAL WAVE WITH SCA LIKELY FOR AMZ710 AND 732. && .PRELIMINARY POINT TEMPS/POPS... SJU 89 78 88 78 / 30 30 50 30 STT 89 80 90 80 / 30 30 50 20 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && 71/10
HAZARDOUS WEATHER OUTLOOK FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS NATIONAL WEATHER SERVICE SAN JUAN PR 522 AM AST WED AUG 5 2009 AMZ710>745-PRZ001>013-060930- 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- 522 AM AST WED AUG 5 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. AMZ715-725-VIZ001-002-060930- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 522 AM AST WED AUG 5 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The San Juan radar (TJUA), 33 km away, was scanning. The volume nearest the first event began at 18:01 UTC.
1 flash flood. Local standard time, as filed.
The U.S. Geological Survey sensor along the Puerto Nuevo River indicated the river rose above the flood stage of 15 feet and reached 16.61 feet.
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, August 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 2026-09-24. Each event’s entry at NCEI: 194331.