Disturbance 96L moved very slowly across the Sahel region of Africa during the week, dumping torrential rains on Wednesday that triggered flash floods that killed at least 55 people in Mali's capital city, Bamako. Serious flooding also affected neighboring Burkina Faso, Gambia, Guinea, Niger and Senegal. Buildings have collapsed, roads have been rendered impassable, and valuable farmland is submerged beneath flood water, affecting over 200,000 people.
JeffMasters, • 3:40 PM GMT on August 31, 2013
The end of August is upon us, and with just one day remaining in the month, the remarkably quiet Atlantic hurricane season of 2013 is highly likely to be just the 6th season since the Hurricane Hunters began flying in 1944 without a hurricane forming by the end of August. This year's combination of no El Niño, warm ocean temperatures, and an exceptionally low August ACE is an event unparalleled in the historical record, going back to 1966.
JeffMasters, • 3:19 PM GMT on August 30, 2013
The most reliable models for predicting the genesis of tropical cyclones up to four days in advance are the GFS, ECMWF, and UKMET models. The models miss most genesis events; in 2011, the probability of detection of a tropical cyclone genesis event was only 9% - 23%, meaning that 77 - 91% of time, a tropical depression or tropical storm formed without the models predicting that it would form. The best model to use for looking at Atlantic tropical cyclone genesis in 2011 was the UKMET model.
JeffMasters, • 3:29 PM GMT on August 29, 2013
California's massive Rim Fire in Yosemite National Park continues to grow, but firefighters took advantage of less windy conditions on Tuesday and had attained 23% containment of the fire as of 9:20 am EDT on Wednesday. According to Inciweb, the Rim Fire has burned 187,000 acres. This ranks as the 7th largest fire in state history, and largest fire on record in the California Sierra Mountains. The Rim Fire will likely climb to be the 5th biggest fire in California's history by this weekend.
JeffMasters, • 2:22 PM GMT on August 28, 2013
Tropical Storm Fernand's life as a tropical storm was brief, lasting just 15 hours at tropical storm strength on Sunday evening and Monday morning. But heavy rains from Fernand have caused the greatest death toll from a 2013 Atlantic named storm yet: thirteen people. The victims all died in in flash floods in Mexico's mountainous terrain west of Veracruz, due to landslides that came down upon houses. Fernand hit Veracruz at 12:45 am EDT Monday morning as a tropical storm with 50 mph winds.
JeffMasters, • 1:51 PM GMT on August 27, 2013
Tropical Storm Fernand's brief life as a tropical cyclone is almost complete, as the 35-mph tropical depression chugs inland over Mexico's mountainous terrain west of Veracruz. Fernand hit Veracruz at 12:45 am EDT Monday morning as a tropical storm with 50 mph winds. The 4 - 8 inches of rain Fernand will dump along its track will be capable of creating flash flooding and dangerous mud slides.
JeffMasters, • 2:55 PM GMT on August 26, 2013
The tropical wave that crossed over Mexico's Yucatan Peninsula and entered the Gulf of Mexico's Bay of Campeche over the weekend has rapidly spun up into Tropical Depression Six. TD 6 is a small storm, and heavy rainfall will be the main threat. Radar images from Alvarado, Mexico show heavy rain bands from TD 6 are already over land, and the 4 - 8 inches of rain TD 6 will bring to the coast is capable of creating flash flooding and dangerous mud slides.
JeffMasters, • 9:19 PM GMT on August 25, 2013
After the wettest July ever recorded in Florida, the Army Corps is battling to draw down the level of Lake Okeechobee. The huge lake represents an important source of fresh water to South Florida, but also poses a grave danger. The 25 - 30'-tall, 143-mile long Herbert Hoover Dike surrounding the lake is vulnerable to leaking and failure when heavy rains bring high water levels to the lake. A 2011 risk assessment estimated the dike's probable failure rate at every fourteen years.
JeffMasters, • 2:39 PM GMT on August 24, 2013
A weak trough of low pressure over the Northern Gulf of Mexico has created a small area of heavy thunderstorms off the coast of Alabama, which are moving west at 10 - 15 mph. Surface pressures are high in the region, wind shear is a moderately high 15 - 20 knots, and an upper level low is centered over the Yucatan Channel is bringing some dry air to the Gulf of Mexico. These factors will discourage development.
JeffMasters, • 12:29 PM GMT on August 23, 2013
Typhoon Trami hit Southeast China on Wednesday as a Category 1 storm with 85 mph winds, after dumping torrential rains in the Philippines that killed 17 people. Trami's rains are creating new flooding flooding problems for a Chinese nation already reeling from a week of deadly floods that have killed over 250 people. Twenty-one of the deaths came on Tuesday evening, due to a flash flood in northwest China's Qinghai Province.
JeffMasters, • 3:07 PM GMT on August 22, 2013
July 2013 was the globe's 6th warmest July since records began in 1880, according to NOAA's National Climatic Data Center (NCDC). NASA rated it the 10th warmest July on record. The year-to-date period of January - July has been the 6th warmest such period on record. July 2013 global land temperatures were the 8th warmest on record, and global ocean temperatures were the 5th warmest on record.
JeffMasters, • 3:20 PM GMT on August 21, 2013
For the first time in history, the U.S. government has ordered that flow of Colorado River water from the 50-year-old Glen Canyon Dam be slashed, due to a water crisis brought about by the region's historic 14-year drought. On Friday, the Federal Bureau of Reclamation--a division of the Department of Interior that manages water and electric power in the West--announced that it would cut water released from Lake Powell's Glen Canyon Dam by 750,000 acre-feet in 2014.
JeffMasters, • 3:20 PM GMT on August 20, 2013
There are no tropical disturbances of note in the Atlantic today. The tropical wave off the coast of Africa (94L) that we were watching on Sunday has become too disorganized to be a threat to develop. None of the reliable computer models is calling for tropical cyclone formation in the Atlantic this week. In the Eastern Pacific, there is a tropical disturbance several hundred miles south of Manzanillo, Mexico that most of the models predict will develop by Thursday.
JeffMasters, • 2:48 PM GMT on August 19, 2013
A new tropical wave (94L) has just emerged over the Tropical Atlantic. 94L has a modest amount of spin, but the storm's heavy thunderstorms are not very intense, and are poorly organized. The Sunday 06Z run of the GFS model and 00Z run of the ECMWF model did not calling for 94L to develop. In their 8 am EDT Sunday Tropical Weather Outlook, NHC gave 94L a 10% of developing by Tuesday, and a 30% chance of developing by Friday.
JeffMasters, • 4:22 PM GMT on August 18, 2013
Tropical disturbance 92L over the South-Central Gulf of Mexico is looking less organized today due to dry air from an upper-level low pressure system over the Gulf. Satellite loops show that 92L has lost the well-developed surface circulation it had Friday, and its heavy thunderstorms are elongated and not well-organized, even though wind shear is a moderate 10 - 20 knots over the the wave, and ocean temperatures are a very warm 29 - 30°C.
JeffMasters, • 3:30 PM GMT on August 17, 2013
Tropical wave 92L crossed over Mexico's Yucatan Peninsula overnight, and the center of the disturbance is now located in the Gulf of Mexico along the west coast of the Yucatan Peninsula. Satellite loops show that 92L has a well-developed surface circulation, but there are no heavy thunderstorms near the center. A moderate-sized region of heavy thunderstorms does lie to the northeast and east of the center, over Cancun, Cozumel, and southwards to Belize.
JeffMasters, • 2:09 PM GMT on August 16, 2013
The tropical wave in the Western Caribbean near the Yucatan Peninsula (92L) is growing more organized this morning, after an evening when it lost most of its heavy thunderstorm activity. Satellite loops show a modest-sized area of heavy thunderstorms that are increasing in intensity and areal coverage, but there are a no signs of a surface circulation. Winds at surface stations in the Western Caribbean also do not show a surface circulation.
JeffMasters, • 2:40 PM GMT on August 15, 2013
Pressures are falling in the Western Caribbean where a tropical wave (92L) is headed northwest at 10 - 15 mph. Cayman Islands radar shows that the thunderstorm activity is disorganized, and satellite loops show only a modest area of heavy thunderstorms, and no signs of a surface circulation. Wind shear is a moderate 10 - 20 knots over the the wave, which should allow slow development today.
JeffMasters, • 12:40 PM GMT on August 14, 2013
July 2013 was the 30th warmest July in the contiguous U.S. since record keeping began in 1895. A persistent trough of low pressure over the middle of the country brought unusually cool conditions there, and strong ridges of high pressure over both the east coast and west coast brought unusually warm conditions to the West and Northeast. Eleven states in the Northeast and West had top-ten warmest Julys on record. Four southern states had top-ten coolest Julys on record.
JeffMasters, • 9:40 PM GMT on August 13, 2013
Category 2 Typhoon Utor is closing in on Southeast China, where it is expected to come ashore near 08 UTC (4 am EDT) on Wednesday, about 150 miles southwest of Hong Kong. Widespread heavy rains are already falling across much of Southeast China. Utor is a large typhoon, and the will dump torrential rains capable of causing deadly flash floods and mudslides over much of Southeast China and Northern Vietnam over the next three days
JeffMasters, • 3:23 PM GMT on August 13, 2013
Typhoon Utor powered ashore on the northern Philippine Island of Luzon on Monday near 3 am local time (3 pm EDT Sunday) as a Category 4 storm with 140 mph winds. Damage was heavy in Casiguran (population 24,000) near where the typhoon made landfall, with 80% of the infrastructure of the town reportedly destroyed, and all roads into the city blocked. Utor is being blamed for two deaths so far, and 44 fishermen are reported as missing.
JeffMasters, • 1:51 PM GMT on August 12, 2013
Earth's most dangerous tropical cyclone so far in 2013 is Category 4 Typhoon Utor, which is closing in on the northern Philippine Island of Luzon. Landfall is expected at approximately 20 UTC (4 pm EDT) Sunday near Casigran. Satellite imagery shows a formidable storm with well-organized spiral bands, a prominent eye, and good (but not excellent) upper-level outflow. Ocean temperatures are very warm, about 30°C (86°F), which is approximately 0.5 - 1.0°C above average.
JeffMasters, • 11:52 AM GMT on August 11, 2013
As we stand on the cusp of the peak part of hurricane season, all of the major groups that perform long-range seasonal hurricane forecasts are still calling for an active 2013 Atlantic hurricane season. NOAA forecasts an above-normal and possibly very active Atlantic hurricane season in 2013, in their August 8 outlook. They give a 70% chance of an above-normal season, a 25% chance of an near-normal season, and 5% chance of a below-normal season.
JeffMasters, • 4:07 PM GMT on August 09, 2013
A historic heat wave is underway in Central Europe, where both both Austria and Slovenia set all-time national heat records on August 8. Three locations in Austria passed the 40°C (104°F) mark today, beating the former national record of 39.9°C (103.8°F) set just last week on August 3rd at Dellach im Drautal. The top spot today (yet to be officially confirmed), goes to Neusiedl/See with a 40.6°C (105.1°F) reading. Slovenia also surpassed its national heat record on August 8 with a 40.8°C (105.4°F) reading at Cerklje ob Krki
JeffMasters, • 11:09 PM GMT on August 08, 2013
In 2012, the official NHC forecast for Atlantic storms was almost as good as or better than any individual computer models--though NOAA's GFS model did slightly better than the NHC official forecast at 12, 24, and 48-hour periods, and the European model forecast was slightly better at 12-hour forecasts.
JeffMasters, • 1:05 PM GMT on August 07, 2013
The climate models used to formulate the 2007 IPCC report suggested that we might see a decrease in the total number of hurricanes in the Atlantic (and worldwide) later this century. However, the latest set of models used to formulate the 2013 IPCC report, due out in September, show that the total number of hurricanes both globally and in the Atlantic may increase, according to a paper published in July 2013 by one of our top hurricane scientists, Dr. Kerry Emanuel of MIT.
JeffMasters, • 9:57 AM GMT on August 05, 2013
Like an annoying fly buzzing around your head that just won't go away, Dorian is back. Dorian began as a tropical wave that moved off the coast of Africa on July 22, became a tropical storm on July 24, and dissipated to a tropical wave on July 27. The remnants of Dorian continued tracking west-northwest north of the Lesser Antilles Islands and into the Bahamas this week. At 5 AM EDT this Saturday morning, the remnants of Dorian reorganized into Tropical Depression Dorian.
JeffMasters, • 3:37 PM GMT on August 03, 2013
After a long trek over the Atlantic Ocean from the coast of Africa, the remains of Tropical Storm Dorian (now called Invest 91L) have finally arrived at the shores of North America. Ex-Dorian is nearly stationary, and is situated over the Northwestern Bahama Islands, just off the coast of Southeast Florida. Satellite loops and Miami radar images show that ex-Dorian has only a limited amount of heavy thunderstorms, which are not well-organized.
JeffMasters, • 1:44 PM GMT on August 02, 2013