Plenty of low level moisture combined with favorable upper level dynamics to produced numerous showers with thunderstorms across the southern sections of Puerto Rico.
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.
Plenty of low level moisture combined with favorable upper level dynamics to produced numerous showers with thunderstorms across the southern sections 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 Sep 14, 11:40 AM AST, 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SAN JUAN PR 1140 AM AST WED SEP 14 2011 .UPDATE...THE DOPPLER WEATHER RADAR DETECTED NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS INITIALLY ACROSS THE SOUTHERN SECTIONS OF PUERTO RICO EARLY IN THE MORNING AND LATER ON ACROSS THE CENTRAL AND NORTH CENTRAL SECTIONS OF PUERTO RICO. SEVERAL FLOOD ADVISORIES WERE ISSUED SO FAR THIS MORNING FOR MUNICIPALITIES ACROSS THOSE SECTOR OF THE ISLANDS. THIS ACTIVITY WAS ASSOCIATED WITH THE MOISTURE LEFT BEHIND TROPICAL STORM MARIA...AND IS EXPECTED TO MOVE TO THE NORTH NORTHWEST AFFECTING THE NORTHERN AND NORTHWESTERN MUNICIPALITIES OF PUERTO RICO THIS AFTERNOON. THE CONVECTION ASSOCIATED WITH A WEAK TROPICAL WAVE...EAST OF THE NORTHERN LEEWARD ISLANDS YESTERDAY WAS ABSORBED BY THE CIRCULATION OF TROPICAL STORM MARIA. A WEATHER IMPROVEMENT IS EXPECTED BY THURSDAY NIGHT AND FRIDAY AND POSSIBLE FOR THE UPCOMING WEEKEND...WITH A RETURN TO THE TYPICAL DIURNAL INDUCED SHOWERS ACTIVITY ACROSS THE REGION. ONLY MINOR CHANGES WERE DONE TO THE PREVIOUS FORECAST PACKAGE. && .AVIATION...SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS EXPECTED. AS A RESULT...MVFR OR EVEN IFR CONDITIONS WILL REMAIN POSSIBLE BTW 14/16Z-14/22Z IN AND AROUND ALL PR AND VI TAF SITES. WINDS SSE 10 TO 20 KT. && .PREV DISCUSSION... /ISSUED 354 AM AST WED SEP 14 2011/ SYNOPSIS...SUBTROPICAL RIDGE WILL HOLD THROUGH THU. LARGE TUTT LOW ACROSS THE CNTRL ATLC WILL RETROGRESS OVR THE NEXT SVRL DAYS AND POSITION ITSELF JUST NORTH OF PR EARLY NEXT WEEK THEN FILL. SUBTROPICAL RIDGE WILL THEN BUILD AGAIN FOR MIDDLE OF NEXT WEEK. DISCUSSION...WEAK TROPICAL WAVE THAT WAS ACROSS THE LESSER ANTILLES YDAY AFTERNOON IS NO LONGER DISCERNIBLE ON EITHER SATELLITE IMAGERY OR MODEL HEIGHT/VORTICITY FIELDS AND LIKELY HAS BEEN ABSORBED BY TS MARIA. NEVERTHELESS...STILL PLENTY OF MOISTURE AND INSTABILITY TODAY TO FUEL SCT SHOWERS AND THUNDERSTORMS UNDER A SOUTHEAST STEERING FLOW. HOT WITH TEMPS LIKELY CLIMBING INTO THE MID 90S WITH LESS CLD CVR THAN YDAY. LEADING EDGE OF MUCH DRIER AIR ALONG 55W PER BLENDED TPW IMAGERY WILL ADVECT QUICKLY INTO THE AREA ON THU AS TRADES ESTABLISH ACROSS THE NORTHEAST CARIBBEAN. AREA THEN BECOMES UNDER A STRONG CONVERGENT PATTERN ALOFT FRI-SAT BETWEEN RETROGRESSING TUTT LOW ACROSS THE ATLC AND SUBTROPICAL RIDGE TO THE NORTH. THIS TO SUPPORT A STRONG SUBSIDENCE CAP AND RAPID EROSION OF LOW LEVEL MOISTURE TO GREATLY INHIBIT CONVECTION ESPECIALLY FRI-SAT. TUTT LOW IS THEN FCST TO FILL EARLY NEXT WEEK WITH SUBTROPICAL RIDGE BUILDING TO THE NORTH NEXT TUE. MOISTURE AND INSTABILITY TO GRADUALLY CLIMB EARLY NEXT WEEK FOR BETTER CHANCES OF AFTERNOON CONVECTION. AVIATION...SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS EXPECTED. AS A RESULT... MVFR CONDITIONS WILL REMAIN POSSIBLE BTW 14/16Z-14/22Z IN AND AROUND ALL PR AND VI TAF SITES. WINDS SSE 10 TO 20 KT. MARINE...SEAS GENERALLY 3-4 FT BOTH ATLC AND CARIB WATERS NEXT FIVE DAYS WITH ISOLD TSTMS. && .PRELIMINARY POINT TEMPS/POPS... SJU 90 78 91 79 / 50 30 30 10 STT 88 80 89 79 / 40 30 30 10 && .SJU WATCHES/WARNINGS/ADVISORIES... PR...NONE. VI...NONE. && 72/06
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SAN JUAN PR 507 AM AST WED SEP 14 2011 AMZ710>745-PRZ001>013-151015- 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- 507 AM AST WED SEP 14 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT DUE TO ALREADY SATURATED SOILS...ANY ADDITIONAL RAINFALL WILL LIKELY RESULT IN RAPID RISES IN SMALL STREAMS AND CREEKS AS WELL AS INCREASE THE POTENTIAL FOR MUDSLIDES IN AREAS OF STEEP TERRAIN. .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-VIZ001-002-151015- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 507 AM AST WED SEP 14 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TODAY AND TONIGHT DUE TO ALREADY SATURATED SOILS...ANY ADDITIONAL RAINFALL WILL LIKELY RESULT IN RAPID RISES IN SMALL STREAMS AND CREEKS. .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), 57 km away, was scanning. The volume nearest the first event began at 15:49 UTC.
1 flash flood. Local standard time, as filed.
Rio Inabon was reported out of its banks at Road 1 near Buyones sector and also at Mercedita Airport.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Puerto Rico in 2011Every state in 2011This day in weather historyWarnings in Puerto Rico, September 2011
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: 350184.