Volcanic Ash in Guam, May 26 to 28, 2003

Name: Volcanic Ash in Guam, May 26 to 28, 2003
Start: 2003-05-26T00:00
End: 2003-05-28T12:00
Location: Guam

May 26 to 28, 2003 · NWS GUA · 3 events in 3 counties and zones

May 26th and 27th. Westerly winds across the Pacific brought thin clouds of ash from the volcano over Guam, Rota, Tinian and Saipan.

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 3

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 GUA wrote it up.

May 26th and 27th. Westerly winds across the Pacific brought thin clouds of ash from the volcano over Guam, Rota, Tinian and Saipan. These clouds had originally blown westward from the volcano by easterly winds out over the Pacific Ocean. Changing wind currents caused by typhoon Chan-hom and a monsoon trough in the area, redirected the ash plume over the Mariana islands.The VOG caused low visibilities over the coastal waters of Tinian and Saipan. The poor visibility caused by the volcanic haze was one of the main reasons why a 21 foot boat carrying four Japanese tourist, a captain and his crew mate got lost at sea for 24 hors before they were rescued by the U.S. Coast Guard on the morning of the 28th.

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 GUA wrote its last area forecast discussion before the first event at May 25, 3:44 PM SST, 8 hours 16 minutes earlier.

Area forecast discussion, May 25, 3:44 PM SST, 8 hours 16 minutes before

AREA SYNOPTIC DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1 PM GUAM LST MON MAY 26 2003

WESTERN NORTH PACIFIC BETWEEN EQUATOR AND 25N FROM 130E TO 180.

TYPHOON CHAN-HOM HAS EXITED THE DISCUSSION AREA TO THE NORTHEAST AND
IS LOCATED NEAR 29N159E. SEE WTPN32 PGTW FROM THE JOINT TYPHOON
WARNING CENTER FOR FURTHER INFORMATION. A MONSOON TROUGH EXTENDS
FROM TYPHOON CHAN-HOM SOUTHWESTWARD TO 20N150E THEN WESTWARD TO
18N130E. LOW-LEVEL CONVERGENCE ASSOCIATED WITH THE TROUGH IS
GENERATING SCATTERED SHOWERS WITHIN 50 MILES OF A LINE FROM 25N162E
TO 20N154E TO 19N142E.

MONSOONAL WESTERLY WINDS ARE PRODUCING SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ACROSS THE REPUBLIC OF PALAU AND YAP STATE
WITHIN 150 MILES OF A LINE FROM 11N133E TO 7N140E TO 5N148E...AND
NEAR CHUUK AND POHNPEI BETWEEN 5N AND 12N FROM 148E TO 159E.

AN UPPER-LEVEL LOW CENTERED NEAR 20N172E IS PRODUCING CLOUDS AND
LIGHT RAIN BETWEEN 13N AND 23N FROM 161E TO 167E...AND BETWEEN 12N
AND 17N FROM 167E TO 180...INCLUDING WAKE ISLAND.

Event by event

3 volcanic ash. Local standard time, as filed.

Volcanic Ash, Guam

When: May 26, 12:00 AM SST to May 28, 12:00 AM SST
Where: Guam forecast zone
Reported by: OFFICIAL NWS OBS.

Volcanic Ash, Saipan

When: May 26, 12:00 AM SST to May 28, 12:00 PM SST
Where: Saipan forecast zone
Reported by: NEWSPAPER

Volcanic Ash, Rota

When: May 26, 12:00 AM SST to May 28, 12:00 AM SST
Where: Rota forecast zone
Reported by: NEWSPAPER

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 Guam in 2003 Every state in 2003 This day in weather history Warnings in Guam, May 2003

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 2026-09-24. Each event’s entry at NCEI: 5355686, 5355986, 5355987.