Dr. Masters co-founded wunderground in 1995. He flew with the NOAA Hurricane Hunters from 1986-1990. Co-blogging with him: Bob Henson, @bhensonweather
By: Dr. Jeff Masters , 3:21 PM GMT on October 22, 2013
Sydney, Australia and the Blue Mountains to its west are bracing for weather conditions that will bring extreme fire danger, with temperatures on Wednesday that are expected to be in the upper 80s, humidities less than 10%, and sustained winds of 15 -25 mph, gusting to 40 mph. These conditions will be "about as bad as it gets", said Shane Fitzsimmons, a fire official for the region. Insurance claims from the huge fires that have ravaged areas just west of Sydney over the past week are already set to exceed $97 million (U.S. dollars), according to The Insurance Council of Australia, even though the worst-hit areas have not been assessed yet. This price tag already makes the disaster Australia's fifth most expensive fire on record, according to EM-DAT, the international disaster database. Australia's just had its hottest September on record, and the 12-month period ending in August 2013 set a record for the hottest 12-month period in Australian history. Australia's warmest summer and 3rd warmest winter on record occurred during this 12-month period.
Wunderground's weather historian Christopher C. Burt has a new post on the history of Australian wild fires. The most expensive and deadly fires in Australian history occurred on Black Saturday, February 7, 2009. Those fires killed 173 people, injured 414, and destroyed 2,029 homes, causing $1.3 billion in damage.
Wunderground member AussieStorm posted this link to a photoalbum of fire pictures taken by residents of the Sydney area.
Figure 1. On October 21, 2013, dozens of wildfires continued to burn in New South Wales, Australia. The fires had already destroyed more than 200 homes, and Australian authorities were concerned that hot, windy weather could exacerbate the situation. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this image at 2:25 p.m. local time (3:25 Universal Time) on October 21. Red outlines indicate hot spots where MODIS detected unusually warm surface temperatures associated with fire.The largest fire shown here is the State Mine fire, which was burning in the Blue Mountains. The fire had burned more than 42,750 hectares, according to the New South Wales Rural Fire Service. Image credit: NASA Earth Observatory.
Hurricane Raymond weakens, but still drenching Mexico
Hurricane Raymond continues to spin just offshore of Acapulco, Mexico, as a Category 2 hurricane with 105 mph winds. As of 11 am EDT Tuesday, Raymond was stationary, centered about 135 miles west-southwest of Acapulco. Raymond brought 5.67" of rain Saturday through Monday to Acapulco, where a Hurricane Watch is posted. Raymond is expected to bring heavy rains of up to 12" to the coast, and this is an area where heavy rains are definitely most unwelcome. Hurricane Manuel hit this region of Mexico with extreme torrential rains when it made landfall on September 15, triggering deadly mudslides and flooding that left 169 people dead or missing and caused $4.2 billion in damage. According to EM-DAT, the International Disaster Database, this was the second most expensive weather-related disaster in Mexican history, behind the $6 billion in damage (2013 dollars) wrought by Hurricane Wilma in October 2005.
Raymond is in an area with weak steering currents, and is likely to show some erratic movement until Wednesday, when a ridge of high pressure is forecast to build in and force the storm west-southwestwards, away from the coast. Recent satellite loops show a weakening trend, as the southeast eyewall is now missing, and the storm's heavy thunderstorms have diminished in intensity. This weakening may be due to the colder waters from below that Raymond's winds have churned to the surface. An Air Force hurricane hunter aircraft will investigate Raymond on Tuesday afternoon.
Wunderblogger Lee Grenci has a detailed look at the ocean temperatures and steering flow affecting Raymond.
Figure 2. MODIS satellite image of Hurricane Raymond, taken at 3:30 pm EDT on October 21, 2013. At the time, Raymond was at peak strength, a Category 3 storm with winds of 125 mph. Image credit: NASA.
Tropical Storm Lorenzo forms in the Middle Atlantic
The 12th Atlantic named storm of 2013, Tropical Storm Lorenzo, was born on Monday afternoon. Lorenzo's formation brings this year's Atlantic tally to 12 named storms, which is one more than the long term average. However, Lorenzo is going to be one of those weak, short-lived tropical storms that likely would have been missed before satellites came along in the 1960s. There have been three other weak, short-lived tropical storms in 2013 that stayed far out to sea that may have been missed before satellites came along--Dorian, Erin, and Jerry. There has been a large increase in the number of "shorties"--Atlantic tropical storms lasting two days or less--since the 1950s, as discussed by Villarini et al. (2011), in their paper, Is the recorded increase in short‐duration North Atlantic tropical storms spurious?
Satellite loops show that Lorenzo has a modest area of heavy thunderstorms, which are pushed to the east side of Lorenzo's center of circulation by strong upper-level winds out of the southwest. Wind shear is moderate, 15 - 20 knots, but is expected to increase to the high range by Tuesday night, giving Lorenzo a rather short life. The storm will not be a threat to any land areas.
Figure 3. Latest satellite image of Lorenzo.
Typhoon Francisco weakening, likely to miss Japan
Typhoon Francisco has steadily weakened since becoming Earth's third Category 5 storm of 2013 on Saturday, and is now a Category 1 storm with 85 mph winds. Francisco is now traversing a large cool patch of ocean up to 2°C colder than the surrounding waters, left behind by the churning action of Typhoon Wipha last week. By the time Francisco makes its closest approach to Japan on Thursday and Friday, it will be a tropical storm undergoing transition to an extratropical storm. However, the latest computer model guidance keeps Francisco well offshore from Japan, and the storm's heaviest rains will miss the country. This is good news for Japan, which is still cleaning up from the record rains that Typhoon Wipha brought last week.
Impressive Typhoon Lekima hits Category 4 strength
The Western Pacific has made up for a slow start to its typhoon season, and has now cranked out its fifth major Category 3 or stronger typhoon of the month. Typhoon Lekima is an impressive Category 4 typhoon with 145 mph winds, intensifying over the warm waters of the Western Pacific about 1,500 miles southeast of Japan. Satellite loops show that Lekima is another very well-organized typhoon with a prominent eye surrounded by a solid ring of eyewall clouds with very cold cloud tops. Lekima is predicted to reach Category 5 strength on Thursday, but will likely recurve to the northeast without affecting any land areas.
Figure 4. MODIS satellite image of Typhoon Francisco (left) and Typhoon Lekima (right), taken at approximately 02 UTC on October 22, 2013. At the time, both typhoons had top winds near 85 mph. Image credit: NASA.
One year ago today: Tropical Depression Eighteen forms
One year ago today, here is what I wrote in my blog post, Tropical Depression 18 forms south of Jamaica: "Tropical Depression Eighteen is here, and appears poised to become Tropical Storm Sandy by early Tuesday morning. TD 18 is over very warm waters of 29.5°C, is in a moist environment, and has light wind shear of 5 - 10 knots. These conditions are very favorable for intensification, and TD 18's heavy thunderstorms are steadily organizing into curved spiral bands….It is unclear at this point whether or not the trough pulling TD 18 to the north will be strong enough to pull the storm all the way out to sea to the northeast; a very complicated steering environment will develop late this week, and it is possible that a narrow ridge of high pressure could build in over TD 18 and force the storm to the west-northwest, with a potential threat to the Northwestern Bahamas and U.S. East Coast by Saturday, as predicted by the ECMWF model."
Figure 5. Morning satellite image of Tropical Depression Eighteen on October 22, 2012.
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