Volcanic Ash in Puerto Rico, July 29, 2001

Name: Volcanic Ash in Puerto Rico, July 29, 2001
Start: 2001-07-29T04:00
End: 2001-07-29T12:00
Location: Puerto Rico

July 29, 2001 · NWS SJU · 13 events in 13 counties and zones

The Montserrat Volcano erupted during the late afternoon of Sunday July 29. A large amount of volcanic ash was released into the atmosphere during Sunday evening and night.

The toll

Deaths: 0
Injuries: 0
Property damage: $300,000
Crop damage: None recorded
Events: 13

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.

What happened

The episode as NWS SJU wrote it up.

The Montserrat Volcano erupted during the late afternoon of Sunday July 29. A large amount of volcanic ash was released into the atmosphere during Sunday evening and night. Simultaneously, a strong tropical wave was crossing the Leeward Islands. Strong southeast winds moved the volcanic ash towards the U.S. Virgin Islands and Puerto Rico. Rainfall during Sunday night and Monday morning deposited the ash across most of the Virgin Islands and eastern Puerto Rico. This was a significant event. Roads, cars and vegetation were covered by an ash layer. Aviation operations across Puerto Rico and the Virgin Islands were suspended until Tuesday morning.

What forecasters said that day

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 Jul 28, 3:15 PM AST, 12 hours 45 minutes earlier.

Area forecast discussion, Jul 28, 3:15 PM AST, 12 hours 45 minutes before

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Event by event

13 volcanic ash. Local standard time, as filed.

Volcanic Ash, Culebra

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Culebra forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Eastern Interior

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Eastern Interior forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Northeast

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Northeast forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, San Juan and Vicinity

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: San Juan and Vicinity forecast zone
Property damage: $300,000
Reported by: EMERGENCY MANAGER

Volcanic Ash, Southeast

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Southeast forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Vieques

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Vieques forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Central Interior

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Central Interior forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Mayaguez and Vicinity

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Mayaguez and Vicinity forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, North Central

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: North Central forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Northwest

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Northwest forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Ponce and Vicinity

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Ponce and Vicinity forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Southwest

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Southwest forecast zone
Reported by: EMERGENCY MANAGER

Volcanic Ash, Western Interior

When: July 29, 4:00 AM AST to 12:00 PM AST
Where: Western Interior forecast zone
Reported by: EMERGENCY MANAGER

What these are

Volcanic Ash: Ash from an eruption that fell on land or reduced visibility.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Puerto Rico in 2001 Every state in 2001 This day in weather history Warnings in Puerto Rico, July 2001

Sources

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: 5259955, 5259956, 5259957, 5259958, 5259959, 5259960, 5259961, 5259962, 5260056, 5260057, 5260058, 5260059, 5260060.