Tropical Storm in Guam, August 17, 2003

Name: Tropical Storm in Guam, August 17, 2003
Start: 2003-08-17T00:00
End: 2003-08-17T23:00
Location: Guam

August 17, 2003 · NWS GUA · 1 event in 1 county or zone

The tropical depression did not cause any wind damage, since winds were relatively light. Flooding in poor drainage areas were noted across Guam.

The toll

Deaths: 0
Injuries: 0
Property damage: $50,000
Crop damage: None recorded
Events: 1

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.

Tropical Depression 12W passes through the Mariana Islands, between Guam and Rota.The tropical depression did not cause any wind damage, since winds were relatively light. Rainfall, however, was heavy with a record setting 3.06 inches falling at the National Weather Service Office during the day.Flooding in poor drainage areas were noted across Guam. A small landslide was reported in Merizo.

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 Aug 16, 3:45 PM SST, 8 hours 15 minutes earlier.

Area forecast discussion, Aug 16, 3:45 PM SST, 8 hours 15 minutes before

AREA SYNOPTIC DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1 PM GUAM LST SUN AUG 17 2003

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

TROPICAL DEPRESSION 12W HAS MOVED JUST NORTHWEST OF GUAM AND IS
CENTERED NEAR 14N145E...MOVING NORTHWEST AT 16 MPH WITH MAXIMUM
SUSTAINED WINDS OF 30 MPH. SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS ARE LOCATED ACROSS THE MARIANA ISLANDS BETWEEN 10N
AND 24N FROM 139E TO 147E. FOR ADDITIONAL DETAILS REFER TO JOINT
TYPHOON WARNING CENTER BULLETIN WTPN31 PGTW.

A TROUGH OF LOW PRESSURE EAST OF LUZON IS GENERATING SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS BETWEEN 12N AND 18N FROM 130E
TO 139E.

AN UPPER-LEVEL LOW NEAR 27N160E IS PRODUCING SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS BETWEEN 23N AND 25N FROM 157E TO 164E.

A NEAR-EQUATORIAL TROUGH EXTENDS NORTHEAST FROM THE EQUATOR AT 158E
TO 10N177E THEN EAST TO 180E. CONVERGENCE INTO THE TROUGH IS
GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM POHNPEI
TO THE MARSHALL ISLANDS...OR IN AN AREA BOUNDED BY 6N156E TO 10N156E
TO 14N174E TO 8N178E THEN BACK TO 6N156E.

Event by event

1 tropical storm. Local standard time, as filed.

Tropical Storm, Guam

When: August 17, 12:00 AM SST to 11:00 PM SST
Where: Guam forecast zone
Property damage: $50,000
Reported by: OFFICIAL NWS OBS.

What these are

Tropical Storm: A tropical cyclone with sustained winds of 34 to 63 knots (39 to 73 mph).

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, August 2003 The 2003 hurricane season

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: 5331430.