A Look at Nargis
Posted May 5, 2008
Updated May 6, 2008
We still have several weeks until the beginning of the Atlantic Hurricane season, which starts June 1st and runs through the end of November. However, news reports in the past few days remind us that conditions supportive of forming tropical storms and hurricanes (increased sea surface temperatures and reduced vertical wind shear) are starting to set in on the northern side of the equator. It's fairly typical to see hurricane season begin a little earlier in the eastern Pacific than in the Atlantic, where peak activity is usually concentrated in the August to October time frame, and it is likewise pretty common for the western Pacific to get an even earlier start on the tropical season. We've seen that this year, as some significant activity has already gotten underway. The western Pacific area recorded a Tropical Storm in mid January (though you could debate the semantics of whether that was a late storm from last year, an early storm for this year, or just a sporadic out of season occurrence) followed by Typhoon Neoguri in mid April. That typhoon reached category two intensity before weakening as it passed Hainan Island and then struck China at tropical storm strength on April 19th. In addition to those two storms, there are two new Typhoons just underway in the western Pacific, one of which (Misawa) has rapidly reached category 4 strength with sustained winds estimated at 115 knots (132 mph).
Moving one basin over, only a single storm has developed as yet over the Northern Indian Ocean, but it was very intense and has had a major impact on Myanmar (also called Burma) since making landfall on Saturday May 3rd. Cyclone Nargis formed over open ocean between India and Myanmar last week and moved eastward, strking southern Myanmar and then turning northeastward as it passed inland (see the attached tracking map from the Joint Typhoon Warning Center, along with two satellite images of the storm as it was approaching the shores of southwest Myanmar). Winds just before landfall were estimated at 115 knots, with gusts around 140 knots (161 mph), making it a category four system on the Saffir-Simpson scale. Note that hurricanes, typhoons and tropical cyclones are all meteorologically the same type of system, they just go by different names in different parts of the world.
As often happens with news reports of a developing disaster, the scale of impact from this storm has increased dramatically over time as some level of communication into devastated areas has been restored, and more information flows in to and eventually out from the national government. A day or so after the storm, fatalities were estimated at 3-400 people, but very recent reports cited by the Voice of America web site have raised the approximate death toll to nearly 4000, with some 3000 missing. Here's hoping those numbers turn out high, or at least level off soon...
* An update from May 6 - unfortunately, the toll continues to rise, with recent reports estimating 10-15,000 dead as a result of the storm.