Irene was a quite large and impressive tropical wave during most of its journey across the Atlantic Ocean during the week of August 14-20, 2011. For most of this time the wave was nearly surrounded by dry air and with enough vertical wind shear to ensure that any intensification would be slow.
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.
Irene was a quite large and impressive tropical wave during most of its journey across the Atlantic Ocean during the week of August 14-20, 2011. For most of this time the wave was nearly surrounded by dry air and with enough vertical wind shear to ensure that any intensification would be slow. Its forward speed of 20 mph somewhat aided the shear in keeping it weak.
By the time the wave was approaching the Lesser Antilles an Air Force Reserve Hurricane Hunter aircraft had found a low level circulation and 53 knots of sustained wind 1,400 feet above the ocean surface. The system was located at 14.9N, 58.5W at 700 pm AST (2300 UTC) on August 20 and the National Hurricane Center issued its initial warnings, including a tropical storm warning for the U.S. Virgin Islands.|The best forecast estimate for the center of Irene was still to pass south of St. Croix, and across the Puerto Rico coastal waters in the Caribbean Sea.
On August 21 at about 600 pm AST the center of Irene passed over St. Croix but the strongest winds were farther north. At 556 pm AST (2156 UTC) Cyril E. King Airport at Charlotte Amalie, St. Thomas recorded a wind gust to 60 knots (69 mph), also when the WSR-88D radar in Puerto Rico showed the strongest winds over and just south of St. Thomas. By 1236 am AST August 22 sustained winds were reported over Vieques of 52 mph with a gust to 71 mph, while a buoy near Esperanza, PR (Vieques) reported a gust to 66 knots (76 mph) at 106 am AST.
Damage from flooding was extensive across the region from Irene, however, though wind caused widespread damage it was relatively minor compared to a more significant hurricane. Numerous trees were blown down on Sunday night (August 21-22) in St. Thomas and St. John. Flooding was reported at Estate La Grange and La Grande Princesse on Saint Croix. The La Grande gut overflowed its banks flooding the legislature parking lot.
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 21, 7:09 AM AST, 10 hours 3 minutes earlier.
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SAN JUAN PR
709 AM AST SUN AUG 21 2011
.SYNOPSIS...TROPICAL STORM IRENE IS EXPECTED TO SLOWLY INTENSIFY
AND PASS JUST SOUTH OF THE LOCAL ISLANDS THIS AFTERNOON AND
TONIGHT THROUGH MONDAY...BRINGING INCREASINGLY DANGEROUS
CONDITIONS TO THE LOCAL ISLANDS.
&&
.DISCUSSION...HAVE ONGOING GFE ISSUES THIS MORNING AND SEVERAL
PRODUCTS ARE RUNNING VERY LATE. HOPE TO HAVE PROBLEMS SOLVED AND
PRODUCTS OUT AS SOON AS POSSIBLE.
LATEST NHC FORECAST PACKAGE CONTINUES TO HAVE TROPICAL STORM IRENE
SLOWLY INTENSIFYING AND TRACKING A BIT CLOSER TO THE LOCAL
ISLANDS. STORM CENTER IS EXPECTED TO PASS JUST SOUTH OF THE LOCAL
ISLANDS THIS AFTERNOON AND TONIGHT THROUGH MONDAY. CLOSER TRACK
AND FORECAST OF TRANSITION FROM TROPICAL STORM TO HURRICANE AS IT
PASSES SOUTHWEST OF PUERTO RICO...PROMPTED THE ISSUANCE OF A
HURRICANE WATCH FOR PUERTO RICO...CULEBRA AND VIEQUES TO GO ALONG
WITH THE TROPICAL STORM WARNING. A TROPICAL STORM WARNING REMAINS
IN EFFECT FOR ALL OF THE U.S. VIRGIN ISLANDS.
OUTER RAIN BANDS ALREADY SPREADING ACROSS THE U.S. VIRGIN
ISLANDS...CULEBRA...VIEQUES AND THE EASTERN SECTIONS OF PUERTO
RICO AND THIS TREND WILL CONTINUE WITH MORE FREQUENT BANDS AND
STRONGER WINDS THROUGH TODAY AND TONIGHT...AND THEN CONTINUING
THROUGH MUCH OF MONDAY FOR PUERTO RICO.
EXPECTED IMPACTS FROM THIS SYSTEM WILL BE VERY HEAVY TO TORRENTIAL
RAINFALL AND EVENTUAL FLASH AND RIVER FLOODING AND MUDSLIDES...
STRONG AND DAMAGING WINDS WITH EXPECTED DOWNED TREES AND PROBABLE
POWER PROBLEMS...EXTREMELY DANGEROUS SEAS AND SURF AND AT LEAST
SOME LOCALIZED COASTAL FLOODING ALONG EAST AND SOUTH FACING
COASTAL LOCATIONS.
&&
.AVIATION...SHWRS AND TSTMS WITH GUSTY WINDS ARE GRADUALLY
INCREASING AHEAD OF THE TS IRENE CURRENTLY LOCATED JUST EAST OF THE
NORTHERN LEEWARDS. SHRA/TSRA WILL OVERSPREAD THE REGION FROM THE
EAST... MAINLY DURING AFTERNOON AND CONTINUING IN EVENING. FREQUENT
MVFR/IFR CONDS WITH TS FORCE WINDS ARE LIKELY AS THE TS IRENE
APPROACHES... STARTING AFTER 21/12Z IN TNCM/TKPK. PR AND USVI SITES
SHOULD EXPERIENCE THESE CONDS AFTER 21/18Z. WEATHER CONDITIONS ARE
EXPECTED TO IMPROVE LATE MONDAY NIGHT.
&&
.MARINE...INCREASINGLY HAZARDOUS MARINE CONDITIONS ARE EXPECTED
TODAY AND TONIGHT AND THEN CONTINUING THROUGH MONDAY...AS
TROPICAL STORM IRENE PASSES JUST SOUTH OF THE LOCAL ISLANDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
SJU 87 80 86 79 / 80 80 70 50
STT 87 80 88 80 / 90 90 70 50
&&
.SJU WATCHES/WARNINGS/ADVISORIES...
PR...TROPICAL STORM WARNING AND HURRICANE WATCH FOR CENTRAL
INTERIOR-CULEBRA- EASTERN INTERIOR-MAYAGUEZ AND VICINITY-
NORTH CENTRAL-NORTHEAST-NORTHWEST-PONCE AND VICINITY-SAN
JUAN AND VICINITY-SOUTHEAST-SOUTHWEST-VIEQUES-WESTERN
INTERIOR.
FLASH FLOOD WATCH FROM 8 AM AST THIS MORNING THROUGH MONDAY
AFTERNOON FOR CENTRAL INTERIOR-CULEBRA-EASTERN INTERIOR-
MAYAGUEZ AND VICINITY-NORTH CENTRAL-NORTHEAST-NORTHWEST-
PONCE AND VICINITY-SAN JUAN AND VICINITY-SOUTHEAST-
SOUTHWEST-VIEQUES-WESTERN INTERIOR.
VI...TROPICAL STORM WARNING FOR ST CROIX-ST. THOMAS/ST. JOHN/ADJACENT
ISLANDS.
FLASH FLOOD WATCH FROM 8 AM AST THIS MORNING THROUGH MONDAY
AFTERNOON FOR ST CROIX-ST. THOMAS/ST. JOHN/ADJACENT ISLANDS.
&&
11/06HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE SAN JUAN PR 1150 PM AST SAT AUG 20 2011 AMZ710>745-PRZ001>013-210500- 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- 1150 PM AST SAT AUG 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PUERTO RICO AND THE ADJACENT ATLANTIC COASTAL WATERS. .DAY ONE...TONIGHT THROUGH MONDAY A TROPICAL STORM WARNING CONTINUES FOR PUERTO RICO...CULEBRA AND VIEQUES. PLEASE REFER TO ALL HURRICANE LOCAL STATEMENTS AND OTHER LOCAL FORECAST PRODUCTS UNTIL FURTHER NOTICE. .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION WILL BE NEEDED DURING THE PASSAGE OF TROPICAL STORM IRENE. AMZ715-725-VIZ001-002-210500- ST. THOMAS ST. JOHN ADJACENT ISLANDS-ST CROIX- NEARSHORE ATLANTIC AND ADJACENT CARIBBEAN COASTAL WATERS- 1150 PM AST SAT AUG 20 2011 THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE U.S. VIRGIN ISLANDS AND THE ADJACENT COASTAL WATERS. .DAY ONE...TONIGHT THROUGH MONDAY A TROPICAL STORM WARNING CONTINUES FOR ALL OF THE U.S. VIRGIN ISLANDS. PLEASE REFER TO ALL HURRICANE LOCAL STATEMENTS AND OTHER LOCAL FORECAST PRODUCTS UNTIL FURTHER NOTICE. .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION WILL BE NEEDED DURING THE PASSAGE OF TROPICAL STORM IRENE.
The national radar mosaic for the moment the first event began.
8 tropical storm, 4 flash flood. Local standard time, as filed.
The Saint Thomas airport ASOS recorded a sustained wind of 46 mph from the northeast.
A downed tree was reported at Melvin Evans road, at Hovensa Training School.
A downed tree was reported blocking road Sprat Hall.
The Saint Thomas airport ASOS recorded a wind gust of 69 mph from the northeast.
Downed tree was reported at Mt Pellier road near Domino Club.
The Saint Croix airport ASOS recorded a wind gust of 51 mph from the south southeast.
Tree downed was blocking La Riene Hill road.
The Christiansted Harbor NOS Station recorded a wind gust of 73 mph from the south southeast.
House flooded at St. Georges road.
Melvin Evans Highway was reported flooded.
Flooding,downed trees and power lines were reported in Saint Thomas.
Flooding, downed trees and power lines were reported in Saint John.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in U.S. Virgin Islands in 2011Every state in 2011This day in weather historyWarnings in U.S. Virgin Islands, August 2011The 2011 hurricane season
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 2026-10-01. Each event’s entry at NCEI: 341601, 341547, 341548, 341600, 341550, 341603, 341565, 341606, 341584, 342530, 340011, 340012.