An area of low pressure at low level of the atmosphere, in combination with an upper level trough which was located across the northeast Caribbean produced active weather mainly across the southern half of Puerto Rico.
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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 area of low pressure at low level of the atmosphere, in combination with an upper level trough which was located across the northeast Caribbean produced active weather mainly across the southern half of Puerto Rico.
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 20, 5:35 AM AST, 1 hour 25 minutes earlier.
AREA FORECAST DISCUSSION...DELAYED NATIONAL WEATHER SERVICE SAN JUAN PR 535 AM AST TUE AUG 20 2013 .SYNOPSIS...A TUTT REMAINED ANCHORED ACROSS THE CENTRAL AND SOUTHWEST ATLANTIC AND CONTINUES TO SINK FURTHER SOUTHWARDS ACROSS THE NORTHEASTERN CARIBBEAN. OVER THE NEXT FEW DAYS...THE TUTT WILL GRADUALLY ERODE THE UPPER RIDGE WHICH NOW EXTENDS SOUTHWEST ACROSS THE NORTHERN LEEWARDS AND LOCAL REGION FROM THE SUBTROPICAL ATLANTIC. A BROAD SURFACE TROUGH SPREAD ACROSS THE EASTERN CARIBBEAN AND EXTENDING NORTHWARDS ACROSS THE ISLANDS...AND HIGH PRESSURE NORTH OF THE AREA WILL MAINTAIN A MODERATE TRADE WINDS ACROSS THE REGION FOR THE NEXT SEVERAL DAYS. A TROPICAL WAVE WITH AXIS NOW CROSSING THE MONA PASSAGE WILL CONTINUE WESTWARD AND EXIT THE REGION LATER TODAY. SHOWERS AND THUNDERSTORMS WILL HOWEVER CONTINUE TO BE ENHANCED ACROSS THE FORECAST AREA AND THROUGH MOST OF THE WEEK DUE TO THE LINGERING UPPER TROUGH...AND INDUCED LOW LEVEL PERTURBATIONS WHICH WILL TO MOVE ACROSS AND AFFECT THE FORECAST AREA FROM TIME TO TIME. && .DISCUSSION...COPIOUS AMOUNTS OF TROPICAL MOISTURE CONTINUED TO BE ADVECTED NORTHWARDS ACROSS THE REGION OVERNIGHT. THIS PATTERN WILL PERSIST OVER THE NEXT FEW DAYS AS THE ITCZ CONTINUED ITS NORTHWARDS MODULATION ACROSS THE REGION. AS A RESULT...EXPECT VERY MOIST AND UNSTABLE ENVIRONMENT WITH PERIODS OF ENHANCED CONVECTION ACROSS THE ISLANDS AND LOCAL WATERS THROUGH MOST OF THE WORK WEEK. LATEST GFS MODEL GUIDANCE CONTINUED TO SUGGEST CONVECTIVE INSTABILITY AND MOISTURE ADVECTION TO REMAIN HIGH THROUGH THE END OF THE WEEK AS WEAK PERTURBATIONS AND ASSOCIATED TROPICAL MOISTURE WILL CONTINUE TO PROPAGATE WESTWARD ACROSS THE EASTERN CARIBBEAN AND AFFECT THE LOCAL AREA. RAINFALL WILL CONTINUE TO BE LOCALLY HEAVY AT TIMES BUT OVERALL EXPECT THE ACTIVITY TO BE MORE LOCALIZED AND NOT WIDESPREAD FOR THE NEXT SEVERAL DAYS. THE SATELLITE DERIVED PRECIPITABLE WATER AND MODEL GUIDANCE ALSO CONTINUED TO SUGGEST THAT THE HIGHEST CONCENTRATION OF TROPICAL MOISTURE WAS NOW MOVING ACROSS THE REGION TODAY...BUT WILL CONTINUE TO AFFECT THE FORECAST AREA FOR THE NEXT SEVERAL DAYS AS THE BROAD SURFACE TROUGH IS EXPECTED TO LINGER ACROSS THE EASTERN CARIBBEAN. STILL LOOKING FOR A GRADUALLY DRIER WEATHER PATTERN THURSDAY INTO FRIDAY...HOWEVER PRESENT MODELS ALL BRING ANOTHER SURGE OF MOISTURE WITH AN EASTERLY PERTURBATION ACROSS THE REGION THURSDAY INTO FRIDAY. UPPER LEVEL DYNAMICS WILL BE LESS FAVORABLE FOR CONVECTIVE ENHANCEMENT OF SHOWERS AND THUNDERSTORMS...BUT EARLY MORNING AND AFTERNOON CONVECTION WILL REMAIN LIKELY THROUGH THE REST OF THE WEEK. SO FAR FOR THE UPCOMING WEEKEND...AN EVEN DRIER WEATHER PATTERN IS EXPECTED BUT THE CHANCE OF AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE IN ISOLATED SPOTS EACH DAY. && .AVIATION...A MOIST AND UNSTABLE AIR MASS WILL CONTINUE ACROSS THE REGION AND WILL INCREASE EVEN MORE AFTER 20/14Z. EXPECT BRIEF PERIODS OF MVFR CONDITIONS IN SHRA AT MOST TAF SITES DURING THE EARLY MORNING HOURS. AFTER 20/16Z SHRA/TSRA AND MTN OBSCURATIONS WILL INCREASE ACROSS THE LOCAL FLYING AREA WITH PERIODS OF MVFR OR EVEN IFR CONDITIONS AT MOST OF PUERTO RICO AND THE U.S. VIRGIN ISLANDS TAF SITES. MOSTLY VFR CONDITIONS WILL PREVAIL ACROSS THE LEEWARD ISLANDS TIL AT LEAST 20/21Z. LOW LEVEL WINDS WILL CONTINUE FROM THE EAST TO EAST SOUTHEAST AT 10 TO 20 KTS AND GUSTY NEAR SHOWERS AND THUNDERSTORMS...INCREASING TO 15 TO 30 KNOT AFTER 20/14Z. && .MARINE...MODERATE TO LOCALLY FRESH TRADE WINDS WILL CONTINUE ACROSS THE REGIONAL WATERS FOR THE NEXT SEVERAL DAYS. WINDS AND SEAS WILL BE HIGHER IN AND AROUND THUNDERSTORM ACTIVITY. SMALL CRAFT SHOULD THEREFORE EXERCISE CAUTION DUE TO SEAS UP TO 6 FEET AND WINDS UP TO 20 KNOTS. FOR ADDITIONAL INFO...PLEASE REFER TO THE LATEST COASTAL WATERS FORECAST PRODUCT ISSUED BY WFO SAN JUAN PR. && .PRELIMINARY POINT TEMPS/POPS... SJU 88 79 89 80 / 60 50 50 30 STT 89 79 89 80 / 70 60 60 50 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. COASTAL WATERS...NONE. && 72/09
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 541 AM AST TUE AUG 20 2013 AMZ710>745-PRZ001>013-210945- 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- 541 AM AST TUE AUG 20 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT THE MOISTURE BEHIND A TROPICAL WAVE ACROSS HISPANIOLA IN COMBINATION WITH THE PROXIMITY OF AN UPPER LEVEL TROUGH WILL CONTINUE TO PRODUCE A MOIST AND UNSTABLE WEATHER PATTERN WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE REGION TODAY AND TONIGHT. THESE FEATURES WILL COMBINE WITH LOCAL EFFECTS TO INDUCE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS MOST OF PUERTO RICO. URBAN AND SMALL STREAM FLOODING ARE LIKELY WITH THE POTENTIAL FOR FLASH FLOOD IN ISOLATED AREAS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THE LINGERING MOISTURE ACROSS THE REGION WILL COMBINE WITH DAYTIME HEATING AND LOCAL EFFECTS TO DEVELOP SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS MAINLY ACROSS INTERIOR AND WESTERN SECTIONS OF PUERTO RICO ON WEDNESDAY. URBAN AND SMALL STREAM FLOODING ARE LIKELY WITH THE POTENTIAL FOR FLASH FLOOD IN ISOLATED AREAS UNTIL WEDNESDAY. .SPOTTER INFORMATION STATEMENT... RAINFALL AMOUNTS REPORTS ARE WELCOME. AMZ715-725-VIZ001-002-210945- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 541 AM AST TUE AUG 20 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT THE MOISTURE BEHIND A TROPICAL WAVE ACROSS HISPANIOLA IN COMBINATION WITH THE PROXIMITY OF AN UPPER LEVEL TROUGH WILL CONTINUE TO PRODUCE A MOIST AND UNSTABLE WEATHER PATTERN WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE REGION TODAY AND TONIGHT. THESE FEATURES WILL COMBINE WITH LOCAL EFFECTS TO INDUCE THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE LOCAL ISLANDS TODAY. URBAN AND SMALL STREAM FLOODING ARE LIKELY WITH THE POTENTIAL FOR FLASH FLOOD IN ISOLATED AREAS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THE LINGERING MOISTURE ACROSS THE REGION WILL COMBINE WITH LOCAL EFFECTS TO DEVELOP SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS PARTS OF THE LOCAL ISLANDS ON WEDNESDAY. URBAN AND SMALL STREAM FLOODING ARE LIKELY WITH THE POTENTIAL FOR FLASH FLOOD IN ISOLATED AREAS. .SPOTTER INFORMATION STATEMENT... RAINFALL AMOUNTS REPORTS ARE WELCOME.
The San Juan radar (TJUA), 12 km away, was scanning. The volume nearest the first event began at 11:02 UTC.
1 flash flood. Local standard time, as filed.
Road PR-181 and Road PR-184 were impassable and closed due to rio Marin out of its banks.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2013Every state in 2013This day in weather historyWarnings in Puerto Rico, August 2013
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: 475554.