A tropical wave (Invest 99L) near 9°N 41°W, halfway between the Lesser Antilles Islands and the coast of Africa, has the potential to develop into a tropical depression later this week as it moves westward at 10 - 15 mph. Visible satellite loops show that the disturbance now has a moderate amount of poorly-organized heavy thunderstorms that continue to slowly increase in intensity and areal coverage. There is no surface circulation, but some counter-clockwise rotation of the large-scale cloud pattern is evident.
JeffMasters, • 1:26 PM GMT on July 31, 2012
The first African tropical wave of 2012 with a potential to develop is Invest 99L, located in the far Eastern Atlantic near 9°N 36°W, midway between the Lesser Antilles Islands and the coast of Africa. Visible satellite loops show a large area of the surrounding atmosphere has a pronounced counter-clockwise spin, though there is no surface circulation. The disturbance's heavy thunderstorm activity is pretty sparse, but appears to be slowly increasing.
JeffMasters, • 3:10 PM GMT on July 30, 2012
A new study from the Berkeley Earth Surface Temperature (BEST) group, which is funded by the Charles G. Koch Charitable Foundation, has found that not only is the planet warming, but "essentially all of this increase results from the human emission of greenhouse gases." Dr. Richard Muller heads the BEST group and now considers himself a "converted skeptic," a conversion he laid out in detail in a New York Times op-ed on Saturday.
angelafritz • 12:21 AM GMT on July 30, 2012
A huge outbreak of severe thunderstorms hit the nation on Thursday, causing damage in fifteen states and knocking out power to over 250,000 customers. Two people were killed, one by a falling tree in Pennsylvania, and one due to a lightning strike in New York. Two possible tornadoes touched down: one in Elmira, New York and another in Brookville, PA. The severe storms covered an unusually large area, erupting along a 1,500-mile long swath of the country from Texas to Connecticut.
JeffMasters, • 2:48 PM GMT on July 27, 2012
A dangerous outbreak of organized severe thunderstorms with strong, damaging winds is expected this afternoon from Ohio eastwards through Pennsylvania and into New England, says NOAA's Storm Prediction Center (SPC). They have put the region, which includes Columbus, Pittsburgh, Philadelphia, and New York City, in their "Moderate Risk" area for severe weather, just one notch below the highest level of alert. Much of the region is also under advisories for extreme heat.
JeffMasters, • 2:16 PM GMT on July 26, 2012
97% of Greenland appeared to have undergone surface melting on July 12--an event completely unprecedented in 30 years of satellite measurements. Temperatures at at the top of the Greenland Ice Sheet had risen above the freezing mark four times in the 12-year span 2000 - 2011. But in mid-July 2012, temperatures eclipsed the freezing mark on five days, including four days in a row from July 11 - 14.
JeffMasters, • 12:58 PM GMT on July 25, 2012
Typhoon Vicente powered ashore about 60 miles (100 km) southwest of Macao, China Monday at 19:30 UTC as a dangerous Category 4 typhoon with 135 mph winds. The typhoon brought sustained winds of 58 mph with a peak wind gust of 83 mph to Hong Kong. No deaths are being blamed on the typhoon, but 118 were injured, and the storm is dumping very heavy rains over Southeast China that will cause serious flooding.
JeffMasters, • 1:40 PM GMT on July 24, 2012
June 2012 was the globe's 4th warmest June on record. June 2012 global land temperatures were the warmest on record; this makes three months in a row--April, May, and June--in which record-high monthly land temperature records were set. China's latest billion-dollar weather disaster is a torrential rainstorm that hit Beijing Saturday night, dumping the the heaviest rains the city has seen in 60 years. The resulting flooding killed 37 people and did $1.6 billion in damage.
JeffMasters, • 12:19 PM GMT on July 23, 2012
The great U.S. drought of 2012 continues to accelerate, and grew larger and more intense over the past week, said NOAA in their weekly U.S. Drought Monitor report issued Thursday, July 19. The area of the contiguous U.S. covered by drought expanded from 61% to 64%, and the area covered by severe or greater drought jumped from 37% to 42%. These are truly historic levels of drought, exceeded only during the great Dust Bowl drought of the 1930s and a severe drought in the mid-1950s.
JeffMasters, • 2:01 PM GMT on July 20, 2012
The coldest place in Greenland is commonly the Summit Station, at the top of the Greenland Ice Sheet, 10,552 feet above sea level, and 415 miles north of the Arctic Circle. In the 12-year span 2000 - 2011, Summit temperatures rose above freezing only four times. Over the past week, though, temperatures at Summit have eclipsed the freezing mark on five days, including four days in a row from July 11 - 14.
JeffMasters, • 9:25 PM GMT on July 18, 2012
The first new all-time national temperature record of 2012 belongs to Morocco, thanks to the 121.3°F (49.6°C) temperature measured at Marrakech on July 17, 2012. The previous record was 120.4°F (49.1°C) at Agadir on July 30, 2009. With a very hot airmass in place over much of North Africa, the Middle East, and Western Asia the remainder of this week, more all-time national heat records may fall.
JeffMasters, • 2:01 AM GMT on July 18, 2012
The great drought of 2012 is upon us. The percentage area of the contiguous U.S. covered by moderate or greater drought increased to 56% by the end of June, and ranked as the sixth largest drought since U.S. weather records began in 1895, said NOAA's National Climatic Data Center in their monthly State of the Climate drought report on Monday. The last time more of the U.S. was in drought occurred in December 1956, with 58%.
JeffMasters, • 10:59 PM GMT on July 16, 2012
On Thursday morning, July 12, 2012 the low temperature at Death Valley, California dropped to just 107°F (41.7°C), after hitting a high of 128° (53.3°C) the previous day. Not only does the morning low temperature tie a record for the world's warmest low temperature ever recorded, the average temperature of 117.5°F is the world's warmest 24-hour temperature on record.
JeffMasters, • 1:31 AM GMT on July 16, 2012
Given that none of the computer models are forecasting tropical storm formation in the coming seven days, SSTs are only slightly above average, and wind shear and vertical stability are above average, I'll go with a 30% chance of a named storm forming in the Atlantic during the remainder of July.
JeffMasters, • 12:55 PM GMT on July 13, 2012
Smoke from this summer's Russian fires rose high into the atmosphere last week, and got caught in the jet stream. The strong winds of the jet stream carried the smoke to western North America this week, where sinking air associated with a strong area of high pressure brought the smoke to the surface. On Wednesday, CBC reported that the smoke had settled over Vancouver, British Columbia, reducing visibility and increasing air pollution.
JeffMasters, • 2:29 PM GMT on July 12, 2012
The science of quantifying how climate change changes the odds of extreme weather events like droughts and floods took a major step forward Tuesday with the publication of an article titled, Explaining Extreme Events of 2011 From a Climate Perspective. The study found found that La Niña-related heat waves, like that experienced in Texas in 2011, are now 20 times more likely to occur during La Niña years today than La Niña years fifty years ago.
JeffMasters, • 1:54 PM GMT on July 11, 2012
Temperatures in the contiguous U.S. were the warmest on record over the past twelve months and for the year-to-date period of January - June. June 2012 was the 14th warmest June on record, so was not as extreme overall as March 2012 (first warmest March on record), April (third warmest April), or May (second warmest May.) However, temperatures were warm enough in June to set a new U.S. record for hottest 12-month period for the third straight month.
JeffMasters, • 9:04 PM GMT on July 09, 2012
Earth's deadliest flood of 2012 hit the Black Sea area of Russia on Saturday, where 300 mm (11.8") of rain fell in less than 24 hours. The resulting flood waters swept through the town of Krymsk in the Krasnodar region early Saturday, killing at least 171 people. The heavy rains were caused by a low pressure system that tracked just north of the region. The counter-clockwise flow of air around the low brought moisture-laden air from the Black Sea northwards over the mountains bordering the Black Sea.
JeffMasters, • 1:14 PM GMT on July 09, 2012
The extraordinary heat wave of late June/early July 2012 toppled more Dust Bowl-era records on Friday, with three cities in Michigan hitting their hottest temperatures ever recorded. Lansing hit 103°, the hottest day in Michigan's capital city since record keeping began in 1863. More record-breaking triple-digit heat is expected Saturday across much of the Midwest and Tennessee Valley. All-time highs in Washington D.C. (106°), Pittsburgh (103°), and Louisville (107°) may be threatened.
JeffMasters, • 12:50 PM GMT on July 07, 2012
It was another day of triple-digit heat across the Midwest Thursday, as the nation continues to bake in the intense heat of the record-breaking summer of 2012. Chicago hit 103° on Thursday, just 2° below the city's all-time hottest temperature of 105°, set on July 24, 1934. The Windy City might have exceeded their all-time heat record, but for the fortuitous formation of a small but intense thunderstorm that hit the airport at 2:45 pm.
JeffMasters, • 2:34 PM GMT on July 06, 2012
The odds of an El Niño event developing in time for the August - September - October peak of hurricane season have grown to 61%, said NOAA's Climate Prediction Center in their latest El Niño/Southern Oscillation (ENSO) diagnostic discussion, released on July 5. Ocean temperatures in the equatorial Pacific have increased to 0.6°C above average this week, which is just above the 0.5°C above-average threshold used to define a weak El Niño event.
JeffMasters, • 3:13 PM GMT on July 05, 2012
Intense heat continues to bake a large portion of the U.S. this Tuesday, with portions of 17 states under heat advisories for dangerously high temperatures. The heat is particularly dangerous for the 1.4 million people still without power and air conditioning due to Friday's incredible derecho event, which is now being blamed for 23 deaths. The ongoing heat wave is one of the most intense and widespread in U.S. history.
JeffMasters, • 7:34 PM GMT on July 03, 2012
It's true. After 17 years as an independent company, Weather Underground has been sold, and will now be part of The Weather Channel Companies (TWCC.) As one of the founders of Weather Underground, I am excited about embarking upon this new chapter in our company's history. Having the infrastructure, resources, and content of The Weather Channel Companies will enable wunderground to create some great new products, and improve the quality and reliability of our existing content.
JeffMasters, • 6:30 PM GMT on July 02, 2012
Violent severe thunderstorms swept through Eastern North Carolina Sunday afternoon and evening, killing three people--one in a collapsed building, and two due to a falling tree. The deadly thunderstorms were fueled by the extreme heat affecting the Southeast, coupled with unusually high levels of moisture. The extraordinary heat and moisture caused high levels of atmospheric instability rarely seen.
JeffMasters, • 11:48 AM GMT on July 02, 2012