November 30 marks the final day of the 2010 Atlantic hurricane season--a strange and highly active season. While it was an exceptionally active year, with 19 named storms, 12 hurricanes, and 5 intense hurricanes, deaths and damages were far below what one would expect from so much activity. To me, this year is most memorable for what didn't happen--we did not get a full fledged hurricane rip through the Deepwater Horizon oil spill, nor did a devastating hurricane cause massive loss of life in Haiti's vulnerable earthquake zone. However, two hurricanes from this year are virtually certain to get their names retired--Tomas and Igor--and two other storms that did billions of damage to Mexico, Karl and Alex, are likely to have their names retired, as well.
JeffMasters, • 1:01 PM GMT on November 29, 2010
We currently have moderate La Niña conditions over the tropical Pacific ocean, which means that a large region of cooler than average waters exists along the Equator from the coast of South America to the Date Line. Cooler than average waters in this location tend to deflect the jet stream such that the Pacific Northwest experiences cooler and wetter winters than average, while the southern U.S. sees warmer and drier winter weather. The last three winters with moderate to strong La Niña conditions occurred in 2007 - 2008, 1999 - 2000, and 1998 - 1999. These winters were extremely variable. The most recent La Niña winter, in 2007 - 2008, was near average in temperature and precipitation; the other two winters were the two warmest winters in U.S. history.
JeffMasters, • 5:38 PM GMT on November 24, 2010
Bolivia tied its all-time hottest temperature mark on October 29, when the mercury hit 46.7°C (116.1°F) at Villamontes. This ties the record set in Villamontes on three other dates, most recently on November 9, 2007. The year 2010 now has the most national extreme heat records for a single year--nineteen. These nations comprise 20% of the total land area of Earth. This is the largest area of Earth's surface to experience all-time record high temperatures in any single year in the historical record.
JeffMasters, • 1:25 PM GMT on November 23, 2010
Colombia is experiencing its worst rainy season in at least 30 years, with at least 136 deaths over the past few months and 1.3 million people affected by flooding. Heavy rains in the capital of Bogota on Wednesday brought the Bogota River to its highest level in 30 years, and more rain is in the forecast--the latest 1-week rain forecast calls for an additional 3 - 5 inches (100 - 150 mm). Colombia's rainy season usually peaks in October, then gradually wanes in November and December as summer arrives. This year's rain have been enhanced by the presence of colder than average Pacific waters caused by La Niña.
JeffMasters, • 2:01 PM GMT on November 22, 2010
October 2010 was the globe's eighth warmest October on record, according to the National Oceanic and Atmospheric Administration (NOAA). NASA's Goddard Institute for Space Studies rated October 2010 the third warmest October on record. Both NOAA and NASA rated the year-to-date period, January - October, as the warmest such period on record. Arctic sea ice extent in October 2010 was the third lowest in the 31-year satellite record behind 2007 and 2009, and is currently at a record low for this time of year.
JeffMasters, • 2:20 PM GMT on November 19, 2010
The formation of Hurricane Tomas this month marks the fourth consecutive year in the Atlantic with a hurricane occurring November 1 or later. It used to be that late-season hurricanes were a relative rarity--in the 140-year period from 1851 - 1990, only 30 hurricanes existed in the Atlantic on or after November 1, an average of one late-season hurricane every five years. But in the past twenty years, late-season hurricanes have become 3.5 times more frequent--there have been fifteen late-season hurricanes, and five of those occurred in the Caribbean. Three of these were major hurricanes, and were the three strongest late-season hurricanes on record.
JeffMasters, • 1:40 PM GMT on November 17, 2010
An area of disturbed weather in the southern Caribbean off the coast of Nicaragua has diminished, and no longer appears to be a threat to develop into a tropical depression. NHC is giving the system a 20% chance of developing into a tropical depression by Thursday. In the Western Pacific, it is currently the quietest typhoon season on record. On average, by this point in the season, there should have been 24.5 named storms, 16 typhoons, and 4 supertyphoons (storms with 150+ mph winds.) So far in 2010, there have been just 14 named storms, 8 typhoons, and 1 supertyphoon.
JeffMasters, • 1:37 PM GMT on November 16, 2010
An area of disturbed weather in the southern Caribbean off the coast of Colombia has changed little today, but has the potential to develop into a tropical depression on Tuesday or Wednesday. The models predict that the steering currents in the southern Caribbean will keep the disturbance moving generally west-northwestward at about 5 - 10 mph for the next three days, which would bring it ashore over Nicaragua or northeast Honduras on Wednesday. NHC is giving the system a 20% chance of developing into a tropical depression by Wednesday. At this time, it appears that the storm will stay confined to the Caribbean.
JeffMasters, • 2:54 PM GMT on November 15, 2010
An area of disturbed weather in the southern Caribbean off the coast of Colombia has seen a slow increase in organization and heavy thunderstorm activity this morning, and has the potential to develop into a tropical depression on Monday or Tuesday. The models predict that the steering currents in the southern Caribbean will keep the disturbance moving generally west-northwestward at about 5 mph for the next five days, which would bring it ashore over Nicaragua or northeast Honduras as early as Tuesday night. NHC is giving the system a 40% chance of developing into a tropical depression by Tuesday. At this time, it appears that the storm will stay confined to the Caribbean, and will not by drawn northwards across Cuba towards Florida and the Bahamas.
JeffMasters, • 2:29 PM GMT on November 14, 2010
An area of disturbed weather in the southern Caribbean off the coast of Colombia has changed little this morning, but has the potential to develop into a tropical depression on Monday or Tuesday. The models predict that the steering currents in the southern Caribbean will keep the disturbance moving generally west-northwestward at about 5 mph for the next five days, which would bring it ashore over Nicaragua or northeast Honduras as early as Tuesday night. NHC is giving the system a 40% chance of developing into a tropical depression by Monday. At this time, it appears that the storm will stay confined to the Caribbean, and will not by drawn northwards across Cuba towards Florida and the Bahamas.
JeffMasters, • 3:10 PM GMT on November 13, 2010
An area of disturbed weather has developed in the southern Caribbean off the coast of Colombia, and has the potential to develop into a tropical depression early next week. Satellite images show that 94L has a limited amount of heavy thunderstorms, but the activity is showing signs of organization, with several curved bands developing on the west side of the center. Water vapor satellite images show a large amount of dry air lies to the north over the northern Caribbean, and this dry air may slow down development to a small degree. SSTs are warm, 29°C, and wind shear is a moderate 10 - 15 knots.
JeffMasters, • 8:11 PM GMT on November 12, 2010
In 2008, we had four named storms in July, and the second most powerful November hurricane on record. Both 2007 and 2005 had rare December storms, and 2003 featured Tropical Storm Anna, the first April tropical storm ever recorded. This year, Hurricane Tomas made 2010 the fourth straight year with a November hurricane, a first. The latest runs of the GFS and NOGAPS models are suggesting the possibility that we will have Tropical Storm Virginie in the Caribbean between Colombia and Nicaragua a week from now. Is hurricane season getting longer? A recently published paper by Dr. Jim Kossin concludes that yes, there is a "apparent tendency toward more common early- and late-season storms that correlates with warming Sea Surface Temperature but the uncertainty in these relationships is high".
JeffMasters, • 1:35 PM GMT on November 11, 2010
Thirty five years ago today, on November 10, 1975, one of the strongest storms in Great Lakes history sank the ore carrier Edmund Fitzgerald on Lake Superior, with the loss of all 29 men aboard. This date in weather history also features four other remarkable record-setting storms: the 1911 Great Cold Front, the 1913 "White Hurricane", the 1940 Armistice Day Blizzard, and the 1998 Super Cyclone. The deadliest weather event in Great Lakes history was the so-called "White Hurricane" of Nov. 9-11, 1913. Twelve ships foundered with all hands lost, and another 29 were stranded or washed ashore, with a death toll of 260-300. Winds were measured as high as 80mph in Buffalo, New York, and 79mph in Cleveland, Ohio.
JeffMasters, • 1:31 PM GMT on November 10, 2010
President Obama is in Jakarta, Indonesia, but that nation's most active volcano--Mount Merapi on Java--is spewing enough ash to potentially cut the President's visit short. Merapi has been erupting since late October, and the mountain's pyroclastic flows and ash have been blamed for the deaths of over 150 Indonesians since the eruption began. The capital city of Jakarta lies about 250 miles west-northwest of Merapi. The winds today are blowing from east to west over the Merapi volcano, and are expected to continue this direction for the remainder of the day. The ash cloud is sufficiently close to the city that just a small change in wind direction could bring ash to Jakarta.
JeffMasters, • 3:01 PM GMT on November 09, 2010
Since the active hurricane period we are in began in 1995, seven of the fifteen years have seen an Atlantic named storm form after November 8. Only two of these storms caused loss of life: Tropical Storm Odette of 2007, whose floods killed eight people in the Dominican Republic, and Hurricane Lenny of 1999, which killed fifteen people in the Lesser Antilles. I believe we are all done this hurricane season with dangerous storms capable of causing loss of life. The latest long-range models don't hint at anything developing over the next seven days, and I give a 30% chance we will see one more inconsequential named storm, which will not cause loss of life if it forms.
JeffMasters, • 1:45 PM GMT on November 08, 2010
Tropical Storm Tomas is merging with a cold front over the open Atlantic Ocean and has only a few more hours of life as a tropical cyclone. Despite bringing heavy rains of 4 - 8 inches to highly vulnerable Haiti on Friday, flooding from the storm is only being blamed for eight deaths in the country. Haiti has thankfully avoided a flooding catastrophe, and it certainly could have gone far worse for Haiti. Still, Tomas' passage caused plenty of flooding damage in Haiti. The heavy rains and floods from the storm will also worsen the country's cholera epidemic, which has already claimed over 500 lives. Cholera is a spread via contaminated water, and Tomas' rains will cause a great deal of water contamination.
JeffMasters, • 3:50 PM GMT on November 07, 2010
Tropical Storm Tomas is over the open Atlantic, headed away from the islands, and is unlikely to trouble any more land areas. Despite bringing heavy rains of 4 - 8 inches to highly vulnerable Haiti yesterday, flooding from the storm is only being blamed for seven deaths thus far, and Haiti has avoided a flooding catastrophe. More Haitians died (12) last weekend from flooding rains of much lesser amounts, so I think part of the credit for the low death toll during Tomas has to go to the preparedness efforts made in advance of the storm.
JeffMasters, • 4:38 PM GMT on November 06, 2010
Data from the Hurricane Hunters show that Tomas has weakened. The 3:28pm center fix found that Tomas' pressure had risen to 992 mb, and the top surface winds seen by the SFMR instrument were just 64 mph. The weakening was probably due to the fact the center of Tomas passed very close to the rugged terrain of Haiti's southwest peninsula, and the rough mountains disrupted the flow into the developing eyewall of the hurricane. Conditions remain favorable for intensification, and Tomas could be an 85 mph Category 1 hurricane when it passes through the southeastern Bahamas and Turks and Caicos Islands on Saturday morning.
JeffMasters, • 8:24 PM GMT on November 05, 2010
Deadly Hurricane Tomas has intensified into a dangerous Category 1 hurricane with 85 mph winds this morning, and is lashing Haiti, eastern Cuba, and the southwestern coast of the Dominican Republic with torrential rains. Recent microwave imagery shows that a long band of heavy rain with rainfall rates of 1/2" - 3/4" per hour lies to the southwest of Port-au-Prince and Gonaives, the two most vulnerable cities in Haiti to catastrophic flooding. The rain band is lined up to bring the earthquake zone of Haiti an additional 3" - 6" of rain today and tonight, bringing the storm total for Port-au-Prince and the surrounding mountains to 6" - 9". Rains of this magnitude are likely to cause extremely dangerous flooding for the 1.3 million Haitians living in makeshift refugee camps, and may cause heavy loss of life.
JeffMasters, • 1:57 PM GMT on November 05, 2010
Tropical Storm Tomas is headed north towards Haiti, and the northernmost spiral bands of the storm have already reached the tip of Haiti's southwestern peninsula, the eastern tip of Jamaica, and eastern Cuba. It appears at this time that the most dangerous flooding rains of 5 - 10 inches will be confined to the southwestern and northwestern peninsulas of Haiti, and that the earthquake zone where 1.3 million people live in makeshift shelters and tents will experience lesser rains that will cause serious but not catastrophic flooding.
JeffMasters, • 7:44 PM GMT on November 04, 2010
Tropical Storm Tomas is headed north towards Haiti, and the northernmost spiral bands of the storm have already reached the tip of Haiti's southwestern peninsula and the eastern tip of Jamaica. It appears at this time that the most dangerous flooding rains of 5 - 10 inches will be confined to the southwestern peninsula of Haiti, and that the earthquake zone where 1.3 million people live in makeshift shelters and tents will experience lesser rains that will cause serious but not catastrophic flooding.
JeffMasters, • 2:11 PM GMT on November 04, 2010
Tomas has struggled mightily over the past few days, and is now just a tropical depression. However, the storm is in an environment highly favorable for strengthening, and the storm still should reach Category 1 hurricane strength before passing over western Haiti on Friday. Even if it does not reach hurricane strength, Tomas is still likely to bring heavy rains of 4 - 8 inches to Haiti. Rains of this magnitude are capable of causing disastrous flooding.
JeffMasters, • 1:38 PM GMT on November 03, 2010
The islands of St. Lucia, Barbados, and St. Vincent and the Grenadines continue to assess damage and clean up after Hurricane Tomas pounded the Lesser Antilles as a strengthening Category 1 hurricane with 90 - 95 mph winds on Saturday. St. Lucia was hardest hit, with fourteen people dead, many more missing, and damage estimated at $100 million, which is 10% of the nation's GDP. Tomas is gradually strengthening, and could be a hurricane by Thursday. On Friday, Tomas is expected to strike Haiti or Jamaica.
JeffMasters, • 2:58 PM GMT on November 02, 2010
Hurricane Tomas dealt a punishing blow to the Caribbean island of St. Lucia on Saturday, with the neighboring islands of St. Vincent and Barbados also suffering heavy damage. St. Lucia received the full brunt of the northern eyewall of Tomas as it intensified, and the St. Lucia weather service reported that sustained winds of 90 - 95 mph affected the island. A state of emergency has been declared, and heavy flooding washed out many bridges and roads. Damage to structures is considerable, with many roofs gone, and damage reported to hospitals, schools, and businesses. Tomas remains a weak tropical storm today, but is expected to regain hurricane strength by Friday.
JeffMasters, • 2:04 PM GMT on November 01, 2010