Figure 1. Infrared VIIRS image of Super Typhoon Vongfong as seen at 17:03 UTC (1:03 pm EDT) on October 7, 2014. At the time, Vongfong was a peak-intensity Category 5 storm with 180 mph winds. Image credit: Dan Lindsey, NOAA/NASA and RAMMB/CIRA.
Figure 2. Infrared VIIRS images of some of the strongest Pacific tropical cyclones of the past year at their peak intensity. The colors tell us the temperature of the cloud tops. The colder the cloud tops, the higher they are, indicating stronger updrafts and thus a more vigorous tropical cyclone. The white colors are temperatures of -80°C (-112°F), and the pink colors (only seen in Haiyan) are still colder, about -85°C (-121°F). This is the temperature at the very top of the troposphere (base of the stratosphere), about 50,000 feet high. Haiyan (195 mph winds) stands out as being much more intense than the other super storms (Rammasun: 155 mph winds; Genevieve: 160 mph winds; Vongfong: 180 mph winds.) Image credit: Dan Lindsey, NOAA/NASA and RAMMB/CIRA (and thanks to TWC's Michael Lowry for putting this mosaic together.)
Vongfong is Earth's fourth Category 5 storm of 2014
Vongfong is Earth's fourth Category 5 storm of the year, and the second in the Western Pacific. The other Western Pacific Cat 5 was Super Typhoon Halong, which topped out at 160 mph winds on August 3, eventually making landfall in Japan on August 10 as a tropical storm. Another Western Pacific Super Typhoon, Rammasun, was only rated a Cat 4 when it hit China's Hainan Island on July 17, killing 195 people and causing over $7 billion in damage. However, a pressure characteristic of a Category 5 storm, 899.2 mb, was recorded at Qizhou Island just before Rammasun hit Hainan Island. If this pressure is verified, it is likely that the storm will be upgraded to a Category 5 in post-season reanalysis. The Eastern Pacific has had two Cat 5s in 2014 that did not affect land: Marie (160 mph winds) and Genevieve (160 mph winds.) The South Indian Ocean has had one Cat 5 this year, Tropical Cyclone Gillian in March (160 mph winds.) Gillian did not affect any land areas. Between 2000 - 2013, Earth averaged five Category 5 storms per year, with 51% of these occurring in the Western Pacific.
Vongfong a threat to Japan
Vongfong began a turn to the north on Wednesday morning, and is a threat to hit Japan on Sunday or Monday. Satellite loops show Vongfong is an extremely impressive storm, with a large area of heavy thunderstorms with very cold cloud tops, excellent upper-level outflow, and a large 25-mile diameter eye. With the typhoon over warm waters of 30°C (86°F) and under light wind shear of 5 - 10 knots, continued existence as a Category 5 storm is possible. The 11 am EDT Wednesday forecast from the Joint Typhoon Warning Center predicted that Vongfong would remain a Category 5 storm through 8 am Thursday. Cooler waters and higher wind shear will induce weakening by Friday as the typhoon approaches Japan. Vongfong will be recurving as it approaches Japan, and the models differ considerably on when and where this recurvature will take place, and thus when Vongfong will make landfall. In their 00Z Thursday runs, the European and GFS models both predicted landfall would occur on the main island of Kyushu, with the European model forecasting a landfall near 18 UTC Sunday, and the GFS model forecasting a landfall about twelve hours later, near 06 UTC Monday.
Figure 3. Rainfall from Typhoon Phanfone as estimated by NASA's TRMM satellite. The typhoon's heaviest rains stayed offshore, but some areas of 6+ inches (yellow colors) were observed west of Tokyo. The typhoon dumped 48 centimeters (19 inches) of rain in the mountainous region of Shizuoka Prefecture. At one point during the storm, rain fell in Shizuoka—the capital city of the prefecture—at a record-rate of 8.7 centimeters (3.4 inches) per hour. Heavy rains from Typhoon Vongfong are expected to fall on soils already saturated by Typhoon Phanfone's rains, which could lead to much more severe flooding than was observed for Phanfone. Image credit: NASA/TRMM
Figure 4. Typhoon Phanfone's heavy rains and resulting runoff led to sediment plumes in Japan's Suruga Bay, visible in the natural-color image (top) acquired October 6, 2014, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite. Such plumes were not apparent on September 29 (bottom image). Image credit: NASA Earth Observatory.
Japan cleaning up from Typhoon Phanfone
Vongfong is following a track remarkably similar to Typhoon Phanfone, which made landfall as a Category 1 storm with 80 mph winds on Japan's main island of Honshu at 7:16 pm EDT Sunday, October 5, 2014 near the city of Hamamatsu in western Shizuoka Prefecture, about 125 miles west-southwest of Tokyo. A few hours later, the core of the typhoon passed over Tokyo, where sustained winds of 53 mph, gusting to 70 mph were recorded. Phanfone killed at least seven and left four missing, injuring at least 62 others. Heavy rains from Typhoon Vongfong are expected to fall on soils already saturated by Typhoon Phanfone's rains, which could lead to much more severe flooding than was observed for Phanfone. Vongfong will also be moving slower than Phanfone was, potentially leading to higher rainfall amounts.
RapidScat measures Tropical Storm Simon's winds
An ocean wind measurement instrument called ISS-RapidScat was launched on September 20, 2014 on a SpaceX Dragon cargo spacecraft, which docked with the International Space Station (ISS) a few days later. On September 30, RapidScat was plucked out of the Dragon and installed on the Space Station, with full activation occurring the next day. Remarkably, we already have the first test data from the instrument--a swath of ocean surface wind data taken in Tropical Storm Simon off the coast of Mexico's Baja Peninsula on October 4. The RapidScat data showed the size of Simon's wind field very well, and would have been of value for NHC to help define the radius of gale (34 kts) and storm-force (50 kts) winds surrounding the storm. It will take a month or more of calibration and testing before RapidScat's winds are ready for real-time forecasting, but this sample data from Simon shows that we have a great new tool to help out with hurricane and marine wind forecasting! See my blog post on RapidScat from September 30 and NASA's October 6 article for more details on this promising new instrument.
Figure 5. Tropical Storm Simon's winds as seen by the International Space Station-RapidScat scatterometer as the storm approached Mexico's Baja California Peninsula at 0210 UTC Time Oct 4 (7:10 p.m. PDT Oct 3). At the time, Simon was intensifying and had top winds of 50 mph. RapidScat gives erroneously high winds in precipitation, and the higher winds (red colors) in this image are not as strong as indicated. Image Credit: NASA-JPL/Caltech.
Video 1. Time-lapse footage of the RapidScat "wind watcher" instrument being installed on the International Space Station, followed by reaction by the team after its activation.
Dangerous Tropical Cyclone Hudhud a threat to India
It's October, the usual time of year when the Southwest Monsoon over India begins to wane. As the monsoon retreats southwards away from India, its dominance over the atmosphere in the North Indian Ocean's Bay of Bengal weakens, allowing tropical cyclones to form after a four-month period of conditions hostile for tropical cyclone formation. The North Indian Ocean typically has two tropical cyclone seasons: one in May before the arrival of the monsoon, and one in October - November as the monsoon retreats. This second season is now at hand, as we have Tropical Cyclone Hudhud in the Bay of Bengal. Tropical Cyclone Hudhud was a strengthening tropical storm with 50 mph winds at 11 am EDT Wednesday, and the storm is under moderate wind shear of 10 - 15 knots and is over warm waters of 29°C (84°F)--conditions which favor intensification. Satellite loops show a well-organized system with plenty of low-level spiral bands and an increasing amount of heavy thunderstorm activity. With warmer sea surface temperatures ahead of the storm and wind shear expected to remain light to moderate, intensification into at least a Category 3 cyclone appears likely before Hudhud hits the central east coast of India on Sunday between 00 - 12 UTC.
Quiet in the Atlantic
Our top three models for predicting tropical cyclone genesis show nothing developing over the next five days in the Atlantic, though we should watch an area of disturbed weather between the Bahamas and Bermuda that could develop early next week. If development does occur, Bermuda would likely be the only land area affected by the storm.
Heavy rains in Central America
A low pressure area over Central America will move off the Pacific coast of Nicaragua late this week and potentially spawn a tropical depression in the Eastern Pacific this weekend. The UKMET and GFS models do develop this system, while the European model does not. In their 8 am EDT Wednesday Tropical Weather Outlook, NHC gave this Pacific disturbance 5-day development odds of 30%. This disturbance is a threat to bring heavy rains and dangerous flooding to Central America over the next five days.
Jeff Masters
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