Strong, Unusual Tropical Cyclone Hits Burma

UPDATE: May 2, 2023 @ 12:30 PM

For the 15th anniversary, at the bottom of this post, I have added a series of news entries from our International Blog as the storm progressed from formation to landfall.

UPDATE: MAY 4, 2009 @ 1:30 PM

From my disaster blog anniversaries post:

Today is the anniversary of Tropical Cyclone Nargis, the deadliest storm ever in Myanmar (Burma), occuring last year. Below is a reprint from our Weather Headlines. NASA has a page with satellite images from Nargis.

"It was the worst natural disaster ever to befall Mynmar (Burma), with a death toll of at least 146,000. And it ranks among the top ten deadliest tropical cyclones historically. One year ago, on May 2, 2008, Tropical Cyclone Nargis swept over the Ayayerawady (Irrawaddy) River Delta and into the capital city, Yangon (Rangoon). Before reaching its landfall, Nargis held storm status as high as a Category 4 hurricane at the time of maximum strength, as sustained winds reached 135 mph.

The severe loss of life was the result of a track parallel to, and roughly along, the shore of the river delta. This allowed the storm to hold its severe strength across the breadth of the massive delta. Severe tidal flooding swept inland along tidal fingers for many tens of miles, making drowning by far the primary cause of storm deaths."

UPDATE MAY 6, 2008 @ 4:32 PM

NEW BLOG: NASA Sat Shows Massive Burma Flooding

UPDATE MAY 5, 2008 @ 7:19 PM

NEW BLOG: First Lady Blames 22,500 Deaths on Burma Gov.

ORIGINAL POST MAY 4, 2008 @ 3:00 PM

Chris Burt, Author of the book "Extreme Weather" emailed me Saturday to say "Perhaps the strongest tropical storm on record has hit Yangon, Mynamar (Rangoon, Burma - the country between India and China) today. The airport reported wind gusts to 138mph (archived observations)." NASA has a couple of great hi-res satellite shots of the storm from May 3 and May 4th, and the Navy has one at landfall.

Chris goes on to say:

"It is virtually unheard of for a Category 3 storm to make landfall this far south on the eastern shores of the Andaman Sea/Bay of Bengal. Knowing Yangon well (I was there just 7 weeks ago) I expect major damage to have occurred to the majority of the weak wood frame and other old structures so common to this city although there should not have been a storm surge due to its inland location."

APPENDIX (ADDED IN 2023):

Here are a series of news entries from our International Blog as the storm progressed from formation to landfall, unchanged from their original text:

APRIL 28, 2008:

As of 0600 UTC Monday, the JTWC reckoned highest sustained winds about Nargis to be 65 knots (120 kmh), or that of a minimal hurricane. A 1200 UTC update showed the same result.

Nargis is the first Bay of Bengal tropical cyclone. As of Monday evening, local time, the eye of TC Nargis was nearly 350 miles east of Chennai, India. Nargis packed highest sustained winds of 75 mph, but it was hovering nearly stationary.

Atmospheric factors such as a growing atmospheric ridge southeast of Nargis and a westerly flow to its north favored a swing towards the northeast within the next day or two. The likely upshot of this shift in track would be a substantial threat later in the week to the coast of Myanmar.

Midspring is a time of tropical cyclone threat over the Bay of Bengal as the South Asian atmosphere shifts out of its winter set-up in readiness for the onset of the South West Monsoon.

Indicators bespeak strengthening of TC 01B over the next 2-3 days. An atmospheric ridge to the southeast of Nargis will help in steering the storm toward the northeast. This outcome is agreed by numerical forecast models and the forecasters of the JTWC. Likely destination for this cyclone will be Mynamar.

--It would seem that Nargis is marking the onset of earliest stage of the South West Monsoon, 2008, over Southeast Asia. It looks as though the worst of the pre-rain heat has come and gone in Thailand; the heat may have peaked in Myanmar.

APRIL 29, 2008:

Tropical Cyclone Nargis (01B) has not strengthened much over the last 24-36 hours. Indeed, as of 1200 UTC Tuesday, the JTWC showed 70-knot (130-kmh) estimated highest sustained winds--up only slightly from 0600 UTC Monday. As discussed by the JTWC, satellite imagery showed the telltails of dry air intrusion and convergence aloft, both of which are unfavorable to sustaining a tropical cyclone or hurricane.

As of 1200 UTC Tuesday, the center of Nargis was reckoned to be about 400 miles (650 kms) east of Chennai, India. Movement was still sluggish at 4 knots (7 to 8 kmh) toward the east-northeast.

Numerical forecast models show Nargis aiming toward the northeast for a late-week landfall upon Myanmar. A lessening of dry inflow and the return to a more diffluent setting aloft would allow Nargis to strengthen meaningfully before reaching land. This storm will need to be watched carefully.

APRIL 30, 2008:

As of late Wednesday, local time, the Bay of Bengal tropical cyclone, Nargis, packed highest sustained winds of hurricane strength as it posed a serious threat to the Myanmar coast. Wednesday evening, the center of Tropical Cyclone Nargis was more than 500 miles south of Kolkata, India, and about as far west-southwest of the Myanmar coast. Highest sustained winds were near 80 mph as the storm drifted northeastward at a sluggish 5 mph.

Numerical forecasts indicated that Nargis would track towards the east and the northeast leading to a likely landfall Friday or early Saturday. Nargis showed potential for further strengthening into Friday.

Maybe it is only my subjective opinion, but this infrared shot (via METEO-7 and NRLMRY) seems to show a somewhat strengthened Tropical Cyclone Nargis versus the same time Tuesday. As of 1200 UTC, the JTWC were showing highest estimated sustained winds of 70 knots, or 130 kmh--as had been indicated at this time Tuesday. In its latest reckoning, the JTWC found drift towards the northeast at 5 knots, or 9 kmh.

Consistency in numerical forecasts since the start of the week leads me to be rather confident of a landfall upon western Myanmar, by TC Nargis, later in the week. As of now, some time between Friday afternoon and Saturday afternoon looks to be the time window for a landfall west or northwest of Yangon. The JTWC have a Saturday morning landfall. Movement is forecast to become more easterly with time. As for storm strength, the JTWC forecast a boost in wind speed ahead of, and leading up until, landfall. I am inclined to believe that it will strengthen, too, although I had earlier foreseen a stronger storm by now.

MAY 1, 2008:

As of Thursday evening, local time, a strengthened Tropical Cyclone Nargis was set to make its last drive towards a landfall upon western Myanmar. At the time, the eye of Nargis was within about 370 to the west of Yangon, Myanmar, and about 200-250 miles from the nearest shore of the South Asian nation. Highest sustained winds about the eye of Nargis topped 100 mph as it drove towards the east at 10 mph.

Landfall by Nargis upon western Myanmar was indicated for Friday evening, local time, or Friday morning, EDT. The likely location was to be west and northwest of Yangon. The setting was such that landfall could happen with Nargis holding sustained winds above hurricane. Impacts would be destructive wind, especially near landfall, and excessive flooding rains, perhaps as far inland as eastern Myanmar.

TC Nargis is making its "last dash" towards land, that being western Myanmar off the Bay of Bengal. Thursday, infrared satellite imagery...

...is of a strengthened storm having sustained winds the equivalent of a Category 2 hurricane. Indeed, the JTWCboosted its top wind speed estimate to 90 knots, or 165-170 kmh. Forward speed was up somewhat to 9 knots, or nearly 17 kmh.

Also as of 1200 UTC, Thursday, the JTWC plotted the eye of Nargis within about 370 miles, or nearly 600 kms, west of Yangon, Myanmar. This was within 200-250 miles, or 320-400 kms, of the western shore of Myanmar.

There is now a fairly solid consensus on the part of numerical forecasts that landfall of Nargis will happen Friday evening, local time, west to west-northwest.

MAY 2, 2008:

Powerful Tropical Cyclone Nargis slammed Myanmar (Burma) Friday to Friday night as it roared ashore from the Bay of Bengal. At landfall, which occurred late in the afternoon, local time, near Cape Negrais, Nargis wielded maximum sustained winds around 130 mph and peak gusts of 150-160 mph; this made it a strong Category 3 or minimal Category 4 storm on the Saffir-Simpson Scale. In any case, Nargis almost certainly produced severe damage and destruction at the point it reached land and along its inland path. Indeed, the cyclone was forecast to maintain hurricane strength as it crossed the Ayeyarwady Delta on its way toward Yangon (Rangoon), the national capital, Friday night to Saturday. Along with powerful winds, the storm also unloaded torrential, flooding rain.

MAY 3, 2008:

Powerful Tropical Cyclone Nargis continues to bring strong winds and heavy rain to Myanmar (Burma) on Saturday as the storm slowly moves to the northeast. At landfall, which occurred late Friday afternoon, local time, near Cape Negrais, Nargis wielded maximum-sustained winds of 130 mph. The cyclone then crossed the Ayeyarwady Delta and headed to the capital city of Yangon where winds gusted to 105 mph. Nargis will continue to weaken as it moves northeastward, but will continue to bring heavy rain to portions of Myanmar and northern Thailand, causing widespread flooding problems.

MAY 4, 2008:

As of early Sunday morning EDT, Tropical Cyclone Nargis was located over eastern Myanmar (Burma), about 150 miles northeast of Yangon. Maximum-sustained winds had decreased to around 35 mph and the storm will dissipate inland over land.

Effects from Nargis have been widespread and have not been confined to just Myanmar. A frontal boundary across southeastern Asia was able to tap into some of the moisture from Nargis, producing heavy rainfall across eastern China and Thailand. Wuhan, the capital of China's Hubei Province, received 6.25 inches of rainfall from Friday into Saturday, while Kan-Yu, Shandong, received 3.18 inches of rainfall on Saturday. The heavy rainfall will be beneficial to croplands on the North China Plain. Heavy rain also extended into Thailand; Chanthaburi received 6.46 inches of rain in a 48-hour span, while more than eight inches of rain has fallen on Mae Sot since late Wednesday. There will still be heavy rain associated with the system to impact eastern Myanmar, northern Thailand, northern Laos and southern China during the next day or two.

I was away from the office as TC Nargis rammed Myanmar--and with it Yangon, the major city--Friday evening, local time. I am still catching up with the sheer power and destructiveness of this mighty storm.

The JTWC reckoned highest sustained winds near the time of landfall to be 105 knots, or 195 kmh--a Category 4 hurricane. *

Landfall happened west of Yangon and the Irrawaddy Delta, yet the storm still had severe impact eastward across the delta and the city. Weather observations from the Yangon airport show estimated sustained winds of 60 knots (110 kmh) for at least four hours Sunday morning. Highest gusts were estimated at a staggering (to me anyways) 120 knots, or 220 kmh.

Breakup of Nargis over highlands east of Yangon was such that little was left to reach Thailand. But the dying cyclone did spur an early shot of South West Monsoon rains including nearly 8 inches as of Sunday afternoon at Chanthaburi, As of Sunday night, it is all over, really, with only some lingering downpours on the Indochina Peninsula.

MAY 5, 2008:

Media reports coming out of Myanmar [Burma] indicate monumental loss of life and severe destruction in the wake of powerful Tropical Cyclone Nargis. The cyclone struck the country in Southeast Asia late Friday to Saturday as it came ashore from the Bay of Bengal; at the time of landfall, Nargis wielded maximum sustained winds of 120-130 mph. On Monday, the government of Myanmar increased the death toll to almost 4,000 and the whereabouts of nearly 3,000 others were unknown, according to Associated Press. The cyclone's violent core passed over the Ayeyarwady [Irrawaddy] River Delta laying waste to much of the low-lying region; in some villages, up to 95 percent of houses were destroyed.

MAY 6, 2008:

*First, I make note of a mistake in my last post. The 105-knot wind reckoned at the time of landfall would rate it a Category 3 hurricane, not Category 4 as I had written. But, 6 or 12 hours ahead of landfall, it was apparently reckoned to have 115-knot sustained winds--good for low-end Category 4 status.

--In the aftermath of Nargis, a few words as to why this storm proved to be among the very worst natural disasters since December, 2004, and the Sumatra tsunami.

The eye of Nargis struck land near Cape Negrais near the southwestern apex of the Ayeyarwady (or Irrawaddy) Delta. From here, it pressed on to the east and northeast, roughly parallel to and only slightly inland from the coast. It was still a hurricane as it reached Yangon after about 100 miles (160 kms) travel over the flat lying Delta. It was after passing Yangon and reaching mountains near the Thailand border the Nargis quickly fell apart.

First, the roughly 100 miles over land was never far from the open sea and so tropical inflow was able to prolong the storm's intensity over land.

Next, the land is flat with stretches of water -- low friction for a land track. This, too, slowed the weakening of Nargis.

Further, southerly -- and thus onshore -- winds rushing in to meet the heart of Nargis drove a storm tide inland along the full breadth of the delta. The interplay of land barely above sea level broken by tidal fingers of the Ayerarwady allowed for maximum inland penetration of the storm tide, which may have reached 15 feet, or upwards of 5 meters. And it is well known that flooding, especially tidal flooding, is a tropical cyclone's deadliest aspect.

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