Waterspout in Guam, September 16, 2001

Name: Waterspout in Guam, September 16, 2001
Start: 2001-09-16T13:30
End: 2001-09-16T13:47
Location: Guam

September 16, 2001 · NWS GUA · 1 event in 1 county or zone

A Waterspout was observed to the west of the National Weather Service Office from 1330 to 1347

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
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.

A Waterspout was observed to the west of the National Weather Service Office from 1330 to 1347

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 Sep 16, 4:05 AM SST, 9 hours 25 minutes earlier.

Area forecast discussion, Sep 16, 4:05 AM SST, 9 hours 25 minutes before

AREA SYNOPTIC DISCUSSION
NATIONAL WEATHER SERVICE TIYAN GU
1 AM GUAM LST MON SEP 17 2001

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

A MONSOON TROUGH STRETCHES FROM 26N130E...SOUTHEASTWARD TO A
DEVELOPING CYCLONIC CIRCULATION NEAR 20N138E. CONVERGENT
SOUTHWESTERLY FLOW SOUTH OF THE TROUGH AXIS COMBINED WITH UPPER
LEVEL DIVERGENCE SOUTH OF A LARGE UPPER-LEVEL LOW LOCATED NEAR
30N140E ARE GENERATING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
WELL NORTH OF YAP AND PALAU...AND WEST OF THE MARIANA ISLANDS. THIS
AREA IS BOUNDED BY A LINE THAT STRETCHED FROM 21N134E TO 25N140E TO
25N143E TO 15N140E TO 14N131E BACK TO 21N134E.

A DEVELOPING MONSOON TROUGH STRETCHES FROM THE CYCLONIC CIRCULATION
SOUTHEASTWARD TO A WEAK CYCLONIC CIRCULATION WEST OF CHUUK NEAR
8N147E...THEN EASTWARD ALONG 8N TO 8N163E THEN NORTHEASTWARD TO A
CYCLONIC CIRCULATION IN THE NORTHERN MARSHALL ISLANDS NEAR 12N167E
AND FINALLY SOUTHEASTWARD TO A WEAK CYCLONIC CIRCULATION NEAR
9N174E. LOW LEVEL CONVERGENCE AROUND THE EASTERN HALF OF THE TROUGH
AXIS IS PRODUCING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER
AN AREA BOUNDED BY A LINE THAT STRETCHED FROM 8N162E TO 18N165E TO
16N AND THE DATE LINE TO 7N AND THE DATE LINE TO BACK TO 8N162E.
THIS AREA IS AFFECTING THE MARSHALL ISLANDS. FARTHER
WEST...CONVERGENCE INTO THE MONSOON TROUGH IS PRODUCING ISOLATED
SHOWERS AND THUNDERSTORMS OVER AN AREA FROM 6N TO 12N BETWEEN 150E
AND 160E. THIS AREA INCLUDES CHUUK STATE AND POHNPEI STATE.

LOW LEVEL CONVERGENCE OF EASTERLY WINDS INTO THE MONSOON TROUGH IS
CREATING A NARROW LINE OF SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS 60 NM EITHER SIDE OF A LINE FROM12N142E TO 16N145E TO
17N152E.  THIS AREA IS AFFECTING THE MARIANA ISLANDS.

AN UPPER-LEVEL LOW NORTHEAST OF WAKE ISLAND NEAR 25N171E IS AIDING
IN THE DEVELOPMENT OF PATCHY LIGHT RAIN AND SCATTERED SHOWERS FROM
18N TO 25N BETWEEN 166E AND 173E.  THIS INCLUDES WAKE ISLAND.

Event by event

1 waterspout. Local standard time, as filed.

Waterspout, Guam

When: September 16, 1:30 PM SST to 1:47 PM SST
Where: Guam County, Central Portion
Reported by: OFFICIAL NWS OBS.

What these are

Waterspout: A tornado over water. One that moves ashore is filed as a tornado from the coastline on.

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

The same day elsewhere

Every storm in Guam in 2001 Every state in 2001 This day in weather history Warnings in Guam, September 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 2026-09-24. Each event’s entry at NCEI: 5267628.