Archive | History RSS for this section

Happy 2nd Birthday

HappyBirthdayI just wanted to wish everyone a Happy Birthday on this second anniversary of Two years ago today, citizen scientist “parrish” provided the first classification. Here’s what we get from that first one:

1,parrish,Td0721(1981),1981-07-22 09:00:00 UTC,2012-09-26 18:57:45 UTC,1981202N24123.TD0721.1981.07.22.0900.37.GMS-1.034.hursat-b1.v05.png,,,,,,,,,band-2.0,,,GMS-1,same,curved

To most, it is a bunch of comma-separated gobbledygook However, to our science team, it is a treasure trove of information — especially when you consider we have 350,000+ lines of this data.

Read More…


Trouble in Paradise: Hawaii and Tropical Cyclones

Hawaii – a tropical paradise, full of sun, fun, palm trees, beauty, mountains, volcanoes and more.  But wait…have you ever thought about Hawaii and tropical cyclones?  Although not frequent, tropical cyclones have battered the Hawaiian Islands several times in recent memory.

Read More…

Do cyclones develop ‘off-season’ in the Atlantic?


Headquarters for the U.S. National Hurricane Center

In the Atlantic, the official dates for the hurricane season are 1 June – 30 November. This certainly doesn’t mean that cyclones only exist during this time frame, yet 97% of all cyclones that have developed have occurred during those months.  While we really won’t know exactly how many cyclones have developed out of season prior to 20th century technological advances, there is evidence of off-season storms in the Atlantic dating back to May of 1771, and more recently tropical storm Beryl in May of 2012. Most cyclones that develop out of season do not typically impact the U.S., but there have been more than handful that have, giving us pause to think what a fickle planet our Earth can be.

Read More…

Featured Storm – Super Typhoon Fengshen (2002)

Origin and Track of Typhoon Fengshen

Origin and Track of Typhoon Fengshen

Typhoon Fengshen was the strongest storm of the 2002 Pacific typhoon season. It developed on July 13 near the Marshall Islands and rapidly intensified due to its small size. Fengshen went from being a tropical depression to a cyclone in only 6 hours. By July 15, Fengshen was given typhoon status, and after initially moving to the north, it turned toward the northwest. On July 18, the typhoon reached its peak intensity of 185 km/h (115 mph), according to the Japan Meteorological Agency; the Joint Typhoon Warning Center (JTWC) estimated peak winds of 270 km/h (165 mph). Disparities like this between agencies are the driving force behind the creation/purpose of  Cyclone Center, and with your help these dissimilarities can be smoothed out. Your classifications are important to us, so we ask that you please take a moment and provide your input on Typhoon Fengshen to help us determine its peak winds.

Typhoons Fengshen (north) and Fung-Wong

Typhoons Fengshen (north) and Fung-Wong (south) undergo the Fujiwhara effect

The JTWC estimated that Fengshen was a super typhoon for five days, which broke the record for longest duration at that intensity. This record would later be tied by Typhoon Ioke in 2006. While approaching peak intensity, Typhoon Fengshen underwent the Fujiwhara effect with Typhoon Fung-wong, causing the latter storm to loop to its south. The Fujiwhara effect is when two nearby cyclonic vortices orbit each other and close the distance between the circulations of their corresponding low-pressure areas. Interaction of smaller circulations can cause the development of a larger cyclone, or cause two cyclones to merge into one.

Fengshen gradually weakened while approaching Japan, and it crossed over the country’s Ōsumi Islands on July 25 as a severe tropical storm. The typhoon swept a freighter ashore, killing four of the 19 crew members aboard. In Japan, Fengshen dropped heavy rainfall that caused mudslides and left $4 million (¥475 million Japanese Yen) in crop damage. After affecting Japan, Fengshen weakened in the Yellow Sea to a tropical depression, before moving across China’s Shandong Peninsula and dissipating on July 28. The typhoon produced strong winds and heavy rain in Japan. A station in Miyazaki Prefecture reported the highest rainfall in Japan with a total of 717 mm (28.2 in). Most of the precipitation fell in a 24 hour period, and the heaviest 1 hour total was 52 mm (2.0 in) in Taira, Toyama. The remnants of Fengshen produced heavy rainfall in northeastern China. The storm affected the capital city of Beijing, becoming the first storm to produce significant impact there since Typhoon Rita in 1972.

– Kyle Gayan is an undergraduate student in Atmospheric Sciences at the University of North Carolina at Asheville and is also a retired USAF Master Sergeant; his 20 years of service was spent exclusively in the weather career field. He recently joined the Cyclone Center team as a classifier and contributor to our social media.

Hurricane Katrina and the Intensifying Coastal Threat

This week Cyclone Center introduces Hurricane Katrina (2005) as one of our featured storms.  This is the 8th anniversary of Katrina’s assault on the northern Gulf of Mexico coast.  The city of New Orleans, despite a massive system of protective levees and pumps, lost over 1500 souls, almost all from drowning when water flooded about 80% of the city.  Since then,  millions of dollars have been spent on the repair and upgrade of the levee system in and around metro New Orleans.  Are they ready for the next one?

“We’ll be absolutely ready for it,” said U.S. Army Corps communications officer Wade Habshey in a recent Discovery News article. “What we have in place now can withstand a Katrina-level storm.”

New Orleans flooding caused by 60 kt. winds, 10-14 ft. storm surge.  Category-5 values: 150 kt winds, 30-35 ft. storm surge.

New Orleans flooding caused by 60 kt. winds, 10-14 ft. storm surge. Category-5 values: 140 kt winds, 25-35 ft. storm surge.

But what exactly is a “Katrina-level” storm?  Winds in downtown New Orleans rarely exceeded minimal hurricane force at the peak of the event.  Storm surge and the strongest winds from the weakening Katrina were focused well to the east in coastal Mississippi.  And yet levees failed, water flooded significant portions of the city, and over 1,500 perished.

An even bigger concern in the long-term are geological changes occurring in the area; coastal portions of Louisiana are sinking into the ocean as climate-forced sea levels continue to rise and land areas sink.  This exacerbates the threat of  hurricanes for a region that experiences one on average every couple of years.  Many climate scientists now believe that hurricanes will be stronger on average in the future as the ocean, which provides the fuel for the storms, continues to warm.

What more should be done?  Government officials exude confidence that the improvements to the levy system will hold up, but we’ve heard that story before.  Claims were made soon after Katrina that the levee system was designed to withstand a Category-3 storm , not something like “Katrina’s strength”.  We’ve already seen that Katrina wasn’t even a hurricane in New Orleans – what happens when a real Category-4 or 5 storm hits the area?  We can only hope that residents will have left, because it’s a very good bet that there will be little dry land to stand on.

– Chris Hennon is part of the Cyclone Center Science Team and Associate Professor of Atmospheric Sciences at the University of North Carolina at Asheville

Diary of 1949 Typhoon Allyn: Part 4 – The end

If you missed it, read the introduction to this article and part 1 and part 2 and part 3.

Admin Bldg. #4 ComMar after Typhoon Allyn. Guam 20 Nov. 1949

Admin Bldg. #4 ComMar after Typhoon Allyn. Guam 20 Nov. 1949

Typhoon Allyn was one of the most destructive to pass Guam. Although the eye passes some distance to the South, damage was severe over most of the island. the following is the conclusion of a diary of events during the 10 hours of the storm’s passage over the island.

“1705K: The eye of the typhoon passed approximately 45 miles to the south of the station between 1615 and 1630K. Our pressure has risen two millibars now and should continue to rise as the storm moves on.

“1720K: An item of interest might be that when the air freight terminal went to pieces, there were several cars wrecked. One in particular, a Ford, is folded up just like an accordion and is one complete wreck. Several other cars are almost as bad. The front end of the terminal building here is beginning to sag and the operations sections has a large hole in it. Doesn’t look good if these winds continue as they are.

“1800K: Forecast diminishing winds and eye passage given to radio at 1715K to be relayed to [other bases]. Courier from Harmon arrived 1730K and was given forecast. Wind at this timeis definitely swinging to south presently southeast at 70 knots with gusts to 85 knots.

“1915K: Forecast given … that winds would be 30 knots by [midnight], present winds SE at 50 knots with gusts to 60 knots.

“2200K: The winds are slowly dying down, but still holding steady around 40 knots with gusts in the 50s. Our pressure is on the rise still and by 6 hours everything should be well under control. Light rain is continuing to fall with intermittent heavy showers.”

So in the time span from noon until 10 p.m., the conditions went from showers to dangerous winds back to rain showers. The result was catastrophic. Nearly $20 million (1949 dollars, about $200 million in 2012 dollars) was done to military installations. The economy of Guam was also severely impacted.  Most – if not all – of several important crops were destroyed: breadfruits (100% lost), vegetables (90%), banana (75%) and so on.

Diary of 1949 Typhoon Allyn: Part 3 – The center passes

If you missed it, read the introduction to this article and part 1 and part 2.

This is the strongest part of the storm. Part 4 will conclude the diary and summarize some information from the damage report.

“1605K: Now getting gusts to 100 m.p.h. Everything still holding fairly well. Visibility is less than one eighth of a mile and rain is falling at a rate of about 4 hundredths of an inch per hour. Emergency lights still not working. Believe the starter is out. Pressure still falling. The clouds still the same with a few breaks in the lower stratus with overcast solid above. Ceiling is now about 50 feet.

“1620K: Put in for a call to Clark field and was greeted by a call from Iwo Jima. They want to close down operations there but advised that they stay in operation for at least 24 hours in case of emergency at this station. Gave them the latest information on the storm and our condition. The wind is estimated at 90 knots now and the visibility is almost zero. The ceiling is estimated at 50 feet in precipitation.

“1632K: Corrugated roofing just started tearing off the roof of the terminal, it made a tremendous crash when the section tore off. All of the troops that are using the terminal as a typhoon shelter had looks of apprehension and I can’t say that I blame them. Indications are that the barometer is starting to level out. The crash of sheet metal on the terminal wasn’t the terminal roof apparently but the remains of the freight terminal on the east side of us. Capt. Highley said that it completely collapsed.Visibility has lifted from zero to 3/4 of a mile but the wind still has 110 knot gusts.

“1650K: Report just received from the Rawin crew, who had just left their hut, and they say that all the buildings are going and that sheet metal is flying thick through the air. Looks like the center has passed us as we had a 1 millibar rise in [pressure in] the last 15 minutes, although will wait for one more observation before we draw any definite conclusions. Winds still haven’t decreased although they are beginning to vear into the SE. Maybe its past us.”

Part 4 will contain the conclusion of this diary and a summary of the damage report.

Diary of 1949 Typhoon Allyn: Part 2 – Conditions worsen

If you missed it, read the introduction to this article and part 1.

What is rawin? What is the hydrogen shack? What is Antrac? What is a T-6? Well, I’m learning as I transcribe this, too. I’ve provided links to other sites that provide more information, but some things are still a mystery to me. For instance, Antrac appears to be related to air traffic control (that is, what I’ve learned from web searching). But I could be wrong.

Page from Consolidated Report on 1949 Typhoon Allyn

Page from Consolidated Report on 1949 Typhoon Allyn

The following is an hour of notes from Typhoon Allyn.

“1437K: Just went outside to check on the T-6’s at the east end of the ramp. They are not in sight. Don’t know whether they have been moved or whether they are out of sight on the low end of the ramp. It is very difficult to stand erect in the open. Andersen AFB is estimating 85 knots. No buildings have blown down but trees are starting to go over. The pole for the Antrac antenna is swaying about six feet at the top. One pole has gone down at the Rawin shack. The banana trees have been uprooted. Rawin reports that the T-6’s were still on the ramp the last time they went by.

“1445K: The corrugated roof on the inflight kitchen quonset is starting to tear off. One section is gone completely and another is starting to rip off. Estimate that the Antrac pole will stay up another hour or hour and a half.

“1455K: Capt. Myers just returned from quarters area, he said that the large hangar doors just went through th PLM hangar as he came by. Heavy rain just began to fall and the visibility has been reduced to less than one eighth of a mile and the wind is now hanging at about ninety knots. The rain is in sheets and horizontal with the ramp. Debris is beginning to fly and the inflight kitchen is still holding its own. The wind tee is just about demolished.

“1510K: The station is being used as a fire control center for this area. The fire marshall has men stationed and is standing by himself for fires that are reprted into this station. The observer will not be able to take psychrometer readings much longer as it is impossible to stand against the wind.

“1515K: Numerous power lines have blown down, and island power is due to go off at anytime. We can’t get the emergency power unit to work.

“1520K: The lights just went out. No emergency power as yet, but repair crews on the way. Estimating the winds at 80 knots and the visibility at three eighths of a mile in torrential rains.

“1530: Pressure is dropping on an average of four millibars per hour and the tendency is still down. The bottom is really falling out of this. Sheet metal is now tearing off of the depot hangars and the Rawin shack is OK; however, the hydrogen shack is going. The doors have been blown off and it shouldn’t last much longer. Debris is traveling along the ramp at about twenty miles per hour.

Diary of 1949 Typhoon Allyn: Part 1 – Preparing for the storm

If you missed it, read the introduction to this article.

Before we continue the narrative, one should have an understanding of the time conventions in these posts. The U.S. military uses time zones named by letter. The “Z” time zone is the same as the UTC, the Universal Time Coordinate, which is the time in …. Guam – in the Western Pacific – is in the “K” time zone. So times listed in the report as “K” refer to local time. For instance, 17:00K is 5 p.m. local time. To learn which letter your time zone corresponds to, visit this web page describing time zones. Keep in mind that the following spans a three hour period.

1949 Typhoon Allyn's path through the Pacific

1949 Typhoon Allyn’s path through the Pacific

Page 4: “Running diary of approach of Typhoon Allyn:

“Arrived at Harmon at 1145K on the 17th and set up shop. Things proceeding normally with winds increasing slightly. The nine light indicator at this station won’t last too long from the indications. It is warbling loudly and the count of the flashes at this time is impossible.

“1315K: Wind has now picked up considerably and the reports from North indicate that they are abandoning the station as the radar tower is about to topple over. We are estimating the winds at this time and cross checking with the Navy. The wind at Harmon is now tearing the inflight kitchen apart. The pressure is falling ominously. We are taking readings every 15 minutes and estimating the wind every 5 min. Also, setting up to take readings with the sling psychrometer and trying to keep an accurate count of all the happenings as they occur.

“1322K: A piece of wiod just went down the ramp must have been a 6×6 and 10 feet long.

“1325K: The rawin tower is no longer visible. Winds must be in the vicinity of 70 knots [80 mph] at this time.

“1336K: [A] communication man just came in and said that JMP is going off the air. They are evacuating the station. We are now out of contact with the rest of the Pacific area.

“1355K: Winds are really beginning to blow now. It is whistling thru all the wires, and the poles next to the stations have quite a list to them. Estimating the winds at 60 knots at this time. Wind tee is hanging on by shreds. Communications are out as they have evacuated both the Weather Central and Guam Broadcast stations, so we are out of contact with everyone but Navy. Rain is coming down in sheets and visibility is getting bad. Visibility at 1/2 mile at this time.

“1420K: Low scud 200 feet [high covering] about eight tenths [of the sky] and [completely overcast] stratocumulus clouds just above, moving beter than 50 knots. Antenna pole at the edge of the building now has a 6 foot oscillation.

A first hand account of a typhoon landfall from 1949

In today’s society of 24-hour news and reporting via satellite, it is not uncommon to have unending first hand coverage of a hurricane, tropical cyclone, or typhoon as it makes landfall. In 1949, however, such an account was quite rare. At NCDC (NOAA’s National Climatic Data Center) we have historical records produced by the Air Force during the period when they flew aircraft into typhoons in the western North Pacific. One such report is the “Consolidated Report” which they produced for each typhoon. This report often includes the analysis of current conditions and forecast maps. It contains summaries of reconnaissance flights, communications, meteorological condition summaries and often a damage report.

Damage from 1949 Typhoon Allyn

Damage from 1949 Typhoon Allyn

One typhoon from 1949 – Typhoon Allyn – passed quite close to Guam. The forecasters there included in their “Consolidated Report: Typhoon ‘Allyn’ November 14-24, 1949” a rare addition: a running diary of the typhoon’s approach to Guam. Over the next few days, I’ll be reproducing the diary here for those interested in a first hand description of the landfall conditions. While this doesn’t contain video feeds, or interviews with local residents, it provides insight into the strength of these violent storms and those who had to work through such conditions. This reproduction of that report is dedicated to those who provided forecasts to our armed services and helped protect lives and property during those years of service at Guam and other forecast offices in the Pacific.

Page 4: “During the morning of 17 November, the wind strengthened to 30 knots [34 m.p.h.], and the dark sky and falling barometer gave sure indications of the advent of the storm. Arrangements had been made for Clark [another Air Force Base] to accept forecast responsibility. Also, Haneda had been instructed to perform the functions of the Typhoon Warning Center, for it appeared certain that Guam’s contact with the [outside world] was to be terminated abruptly and for an indefinite period. Acting on instructions to retain responsibility as long as possible, the Center almost overplayed its hand. The plan called for the Center to issue bulletin 13 [bulletins are their term for a warning] by 17:30Z. Clark was to issue bulletin 14; however 15 minutes before the bulletin 13 was ready for transmission, the communication station ceased operations. It was only by special arrangement that this final message was transmitted. By 04:00Z, 17 November, the surface wind was near 50 knots [57 m.p.h.] making the weather station an unhealthy place due to the proximity of a 40 foot radar tower; consequently, all personnel evacuated to typhoon shelters.

“Due to the fact that the weather station at Harmon Air Force Base was located in a typhoon proof structure, it was manned throughout the storm. The following remarks have been taken from a log kept by forecasters who operated that station, beginning 17 November at 11:45K (01:45Z).”

The remainder of this diary chronicles the ensuing 12 hours of the typhoon’s interaction with Guam.

To be continued…