Tropical Storm, Micronesia
- When
- May 21, 6:00 AM GST to May 22, 10:00 PM GST
- Where
- Micronesia forecast zone
- Crop damage
- $1,000
- Reported by
- Official NWS Observations
Tropical Storm in Guam, May 21 to 22, 2011
Tropical Depression 04W was intensifying into Tropical Storm Songda as it passed just south of Yap island around 1200 GST on Saturday May 21st, moving west-northwest at 6 mph. The highest sustained wind recorded at Yap Airport was from the east at 25 mph that evening at 1958 GST, and the highest gust was from the east at 49 mph at 1931 GST.
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- $1,000
- 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 GUM wrote it up.
Tropical Depression 04W was intensifying into Tropical Storm Songda as it passed just south of Yap island around 1200 GST on Saturday May 21st, moving west-northwest at 6 mph. The highest sustained wind recorded at Yap Airport was from the east at 25 mph that evening at 1958 GST, and the highest gust was from the east at 49 mph at 1931 GST. The lowest sea level pressure was 997.3 mb, also at 1931 GST. Rainfall for the 24 hour period ending at 2200 GST on the 22nd was 6.11 inches.
Only minor damage amounting to about $1,000 was sustained, mainly to crops.
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 Guam wrote its last area forecast discussion before the first event at May 20, 8:40 AM UTC, 11 hours 20 minutes earlier.
Area forecast discussion, May 20, 8:40 AM UTC, 11 hours 20 minutes before
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE TIYAN GU 640 PM CHST FRI MAY 20 2011 .SYNOPSIS... RADAR SHOWS ISOLATED SHOWERS ACROSS THE COVERAGE AREA...ALTHOUGH SEVERAL SHOWERS TRAINED ACROSS OUR WEATHER OFFICE TODAY. SATELLITE SHOWS ISOLATED TRADE-WIND SHOWERS NEARBY AND UPSTREAM. A TROPICAL CYCLONE FORMATION ALERT HAS BEEN ISSUED FOR 98W CENTERED NEAR 9N141E. && .DISCUSSION... MODELS DID NOT INITIALIZE 98W REAL WELL...BUT SEEM TO BE CATCHING UP WITH TIME. IT IS EXPECTED TO INTENSIFY AND DRIFT WEST-NORTHWEST IN THE COMING DAYS. OTHERWISE...LIGHT TO MODERATE TRADE WIND FLOW AND ISOLATED SHOWERS WILL PREVAIL FOR GUAM ZONES. GFS INDICATES MOISTURE COULD GRADUALLY INCREASE NEXT WEEK FROM EAST-SOUTHEAST. ONLY MINOR CHANGES WERE MADE TO PREVIOUS GRIDS AT THIS TIME. && .MARINE... IPAN BUOY SHOWS COMBINED SEAS 5 FT/8 SEC FROM ENE. LIGHT TO MODERATE TRADE WIND CONDITIONS ARE EXPECTED THROUGH THIS FORECAST. && UPDATED TO INCLUDE MICRONESIA DISCUSSION .EASTERN MICRONESIA... A WEAK CIRCULATION CENTERED AT ABOUT 5N153E...A SURFACE TROUGH RUNNING FROM THE CIRCULATION TO 10N157E AND TRADE WIND CONVERGENCE ARE PRODUCING OVERCAST SKIES...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BETWEEN 2N AND 11N FROM 152E TO 164E. POHNPEI AND KOSRAE ARE WITHIN THIS AREA OF INCLEMENT WEATHER. EXTENDED SCATTERED SHOWERS ONE PERIOD INTO SATURDAY SINCE THE MODELS KEEP SCATTERED SHOWERS OVER THESE LOCATIONS AT LEAST THROUGH THAT POINT. MAJURO SHOULD BE MAINLY DRY THROUGH THE FORECAST PERIOD. && .WESTERN MICRONESIA... CHUUK IS UNDER OR JUST WEST OF THE SAME CONVECTIVE CLOUD MASS WITH SCATTERED SHOWERS THAT GAVE POHNPEI AND KOSRAE SCATTERED SHOWERS ON FRIDAY. THE MODELS GIVE CHUUK SCATTERED SHOWERS THROUGH AT LEAST SATURDAY. A MONSOON TROUGH STRETCHES FROM MINDANAO TO BETWEEN PALAU AND YAP STATE TO TROPICAL DISTURBANCE 98W CENTERED NEAR 9N142E. TROPICAL DISTURBANCE 98W HAS JUST BEEN DECLARED TROPICAL DEPRESSION 04W AND IS MOVING TOWARD THE NORTHWEST AT 3 KTS. TD04W WILL AFFECT YAP WITH SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS BEGINNING LATER THIS EVENING AND KOROR BEGINNING ON SUNDAY. FOR MORE INFORMATION ON TD04W REFER TO JTWC TROPICAL CYCLONE WARNING UNDER THE WMO HEADER WTPN31 PGTW. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...NONE. MARIANAS WATERS...NONE. && SIMPSON/DEVITA
Event by event
1 tropical storm. Local standard time, as filed.
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
- Tornadoes and Hail in Kansas, May 21, 2011
- Excessive Heat in Kentucky, May 21, 2011
- Hail in Nebraska, May 21, 2011
- Hail in Kansas, May 21, 2011
- Tornado and Flash Flood in Texas, May 21 to 22, 2011
- Tornado and Hail in Minnesota, May 21 to 22, 2011
- Hail and Damaging Winds in Iowa, May 21, 2011
- Flooding in Arkansas, May 21 to 31, 2011
- Flash Flooding in Maine, May 21, 2011
- Damaging Winds in Tennessee, May 21, 2011
- Tornadoes and Hail in Oklahoma, May 21, 2011
- Tornado and Hail in Missouri, May 21, 2011
More
Every storm in Guam in 2011Every state in 2011This day in weather historyWarnings in Guam, May 2011The 2011 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: 315457.