weather Tagged ‘weather’

Steve Gregory on Current Tropical Conditions

Tuesday, August 26th, 2014

Hurricane CRISTOBAL Northbound – ‘97L’ Needs Monitoring – Strong System over Africa

By: SteveGregory , 4:01 PM GMT on August 26, 2014

HURRICANE CRISTOBAL

CRISTOBAL intensified into a hurricane early last night as wind shear eased a bit, and outflow improved somewhat to the North and south. Shear remains relatively high near 20Kts, and with no improvement in the outflow pattern above the storm expected and the proximity to drier to its west – significant intensification appears unlikely as the 988mb storm moves Northward during the next 2 days along the western periphery of the sub-tropical (Bermuda) High centered in the central Atlantic. All the models are now in excellent agreement on both the track and intensity forecast for CRISTOBAL, and except for large waves and localized rip currents along the east coast – CRISTOBAL will have no impact on the US mainland

INVEST 97L POSES A POTENTIAL THREAT OF DEVELOPMENT THIS WEEKEND

Although NHC dropped 97L overnight, this system is now BACK on the NHC home page chart, most likely due to several global models now forecasting it to develop this weekend as it approaches the Leeward Islands – with the GFS and a few other models tracking it as a cyclone into the southeast coast of the US mainland late next week. Because NHC ‘dropped’ the system over night, none of the specialized hurricane models we executed during the 12Z cycle run. However, the models will almost certainly be initialized for the 18Z cycle run later today. That said – the system is currently surrounded by dry and somewhat stable air with no significant outflow signature seen on SAT imagery at this time; so development, if any, will be quite slow for the next 72 hours.

STRONG DISTURBANCE STILL WESTBOUND OVER AFRICA

Finally, the strongest African tropical disturbance of the season is now located over west-central Africa with a long history of deep convection and a well established rotation in low to mid levels. The disturbance is now moving slowly westward, and is expected to emerge off the west African coast this weekend. Some model projections forecast this system to gradually intensify next week – but also put it on a more Northwesterly track next week – implying this system will start heading out to sea by later next week.

Fig 1: Early morning VIS imagery shows the center of CRISTOBAL on the NW side of deep convection moving Northward at about 5Kts (based on the last 6 hours of RECON/SAT image tracking). The overall satellite signature is highly unusual for a tropical cyclone, especially of hurricane intensity – with the system appearing to be along the southern edge of a mid-latitude frontal boundary. In some respects, that is exactly what has occurred over the last 24 hours, with the southward plunge of well defined dry air surge to the immediate west of the cyclone, leading to a ‘linear’ type orientation of convection extending from well north of CRISTOBAL southward to the storm itself. There is a small possibility that this ‘dynamic’ boundary actually helped intensify the cyclone, despite the moderate shear and dry air that is just west of the storms core circulation. Normally, dry air this close to a relatively weak and sheared system like we had would weaken or totally halt intensification – but in this case (the first I’ve ever seen) – the opposite occurred. It’s worth noting that the dry air surge extended into the northern GOM as well – triggering a line of strong convection there.

Fig 2: The above overview of the tropical Atlantic shows a significant tropical wave/disturbance that was (and now again, is) 97L approaching 50W, and is still westbound at ~16Kts. Dry air is to the north and northwest of the system does not appear to be infiltrating the central area of what isolated convection there is. However, the system still remains in a less than favorable area of somewhat stable air – with no upper level wind support. As the system approaches the far eastern CARIB late this week, the environment should become somewhat more favorable for development.

Fig 3: Enhanced IR imagery over Africa earlier this morning highlights the very strong system in west-central Africa. This system had been moving W/SW for the last 36 hours – but has slowed its forward motion somewhat, and is expected to move on a West/Northwest (290°) during the next few days.

Fig 4: The above image over Africa includes satellite derived winds – and show a well established cyclonic flow around the major system of interest – just as it had for the last 2 days

Fig 5: The global models like the NAVY GEM above – and the GFS & CMC forecasts (not shown) all forecast the system to slowly intensify next week, with the GFS then carrying the system into the SE U.S. coast as a cyclone. Clearly, this system needs close monitoring.

from:    http://www.wunderground.com/blog/SteveGregory/comment.html?entrynum=220

El Nino 2014?

Tuesday, May 20th, 2014

El Niño: Is 2014 the new 1997?

May 19, 2014:  Every ten days, the NASA/French Space Agency Jason-2 satellite maps all the world’s oceans, monitoring changes in sea surface height, a measure of heat in the upper layers of the water.   Because our planet is more than 70% ocean, this information is crucial to global forecasts of weather and climate.

Lately, Jason-2 has seen something brewing in the Pacific—and it looks a lot like 1997.

“A pattern of sea surface heights and temperatures has formed that reminds me of the way the Pacific looked in the spring of 1997,” says Bill Patzert, a climatologist at NASA’s Jet Propulsion Laboratory. “That turned out to be the precursor of a big El Niño.”

splash

A new ScienceCast video examines the evidence that an El Niño is developing in the Pacific.  Play it

“We can’t yet say for sure that an El Niño will develop in 2014, or how big it might be,” cautions Mike McPhaden of NOAA’s Pacific Environmental Research Laboratories in Seattle, “but the Jason-2 data support the El Niño Watch issued last month by NOAA.”

What Jason-2 has been seeing is a series of “Kelvin waves”—massive ripples in sea level that travel across the Pacific from Australia to South America.  Forecasters are paying close attention because these waves could be a herald of El Niño.

The two phenomena, Kelvin waves and El Niño, are linked by wind. Pacific trade winds blow from east to west, pushing sun-warmed surface waters toward Indonesia.  As a result, the sea level near Indonesia is normally 45 cm higher than it is near Ecuador.  Researchers call that area the “warm pool”—it is the largest reservoir of warm water on our planet.

Sometimes, however, trade winds falter for a few days or weeks, and some of that excess sea level   ripples back toward the Americas. “That’s a Kelvin wave,” says McPhaden. “It’s not unusual to see a couple every winter.”

El Niño happens when trade winds falter not just for days, but for many months. Then Kelvin waves    cross the Pacific like a caravan, raising sea level and leaving warmer equatorial waters in their wake.

On May 8th, the National Centers for Environmental Prediction forecasted a 65% chance of El Niño developing during the summer of 2014. More

“The El Niño of 1997/98 was a textbook example,” recalls Patzert. “At that time we were getting data from TOPEX/Poseidon, a predecessor of Jason-2.  Sea surface maps showed a whitish bump, indicating a sea level some 10 centimeters higher than usual, moving along the equator from Australia to South America.”

“The same pattern is repeating in 2014,” says McPhaden. “A series of Kelvin waves generated by localized west wind bursts in the western Pacific that began in mid-January 2014 are headed east. Excitement is building as a third weakening of the Pacific trade winds happened in mid-April.”

Ocean and atmospheric scientists at NOAA and NASA are carefully monitoring the Pacific trade winds. The tipping point for declaring a significant El Niño will be an even longer lasting, larger collapse in Pacific trade winds, possibly signaling a shift in weather all around our planet.

“It will become much clearer over the next two to three months whether these recent developments are the forerunner of a major El Niño—or any El Niño at all,” says McPhaden.

from:    http://science.nasa.gov/science-news/science-at-nasa/2014/19may_elnino/

Record Drought in California

Thursday, May 15th, 2014

Record May Heat, Drought, and Fires Scorch California

By: Dr. Jeff Masters , 2:21 PM GMT on May 15, 2014

Record May heat sent temperatures soaring above 100° in much of Southern California on Wednesday, and fierce Santa Ana winds fanned fires that scorched at least 9,000 acres in San Diego County, forcing thousands to evacuate. For the second consecutive day, the Los Angeles Airport set a record for the hottest May temperature since record keeping began in 1944. Wednesday’s 96° beat the record set on Tuesday of 93°. Other all-time May record heat was recorded at Camarillo (102°) and Oxnard (102°) on Wednesday. In Downtown Los Angeles, the mercury hit 99° on Wednesday, falling short of the all-time May record is 103° set on May 25, 1896. More record heat is forecast on Thursday, and hot offshore Santa Ana winds will bring extreme fire danger.


Figure 1. A firenado in Fallbrook, California at old Highway 395 and Interstate 15 on May 14, 2014. Image credit: Jena Rents via Twitter.


Figure 2. True-color MODIS satellite image of fires burning in Southern California and Northern Mexico on Wednesday afternoon, May 14, 2014. Image credit: NASA.

100% of California in severe to exceptional drought
Today’s U.S. Drought Monitor report showed grim news for California: 100% of the state is now in severe or higher drought, up from 96% the previous week. Though just 25% of California is classified as being in the highest level of drought, “Exceptional”, Erin McCarthy at the Wall Street Journal estimates that farms comprising 53% of California’s $44.7 billion market value lie in the Exceptional drought area. Averaged state-wide, the Palmer Drought Severity Index during April 2014 was the second worst on record, behind 1977. For the 12-month period ending in April, drought conditions in California for 2013 – 2014 were also the second most severe on record, slightly below the 2008 – 2009 drought. To break the drought, most of the state needs 9 – 15″ or precipitation to fall in one month. This amounts to more than a half-year’s worth of precipitation for most of the state.


Figure 3. The May 13, 2014 U.S. Drought Monitor showed 100% of California in severe or higher drought, with 25% of the state in the highest level of drought, “Exceptional.” Image credit: U.S. Drought Monitor.

California’s rainy season is over
The California October through April rainy season is now over. Between October 2013 and April 2014, the state received 10.44″ of precipitation, which is just 51% of average for the period, and the third lowest such total on record. Going back to 1895, the record low mark was set in 1976 – 1977, when the state got just 34% of its average rainy season precipitation. California typically receives less than 10% of its annual precipitation between May and September, and the coming hot and dry summer in combination with a severely depleted Sierra snowpack will cause a severe fire season and significant agricultural damages. The fifth and final snow survey of the season on May 1 found that the statewide snowpack’s water content–which normally provides about a third of the water for California’s farms and cities–was only 18% of average for the date. Already, the 2014 drought has cost the state at least $3.6 billion in agricultural damages, the California Farm Water Coalition estimates. CAL FIRE recently announced it had hired 125 additional firefighters to help address the increased fire threat due to drought conditions.

from:    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2679

2014 Tornado Forecast

Saturday, April 26th, 2014

Tornado Alley To Be Active This Season With A Number Of Outbreaks

Tornado Alley To Be Active This Season With A Number Of Outbreaks

(TheWeatherSpace.com) – Recent trends suggest that the Central United States will be very active this season, whereas some seasons it is not.  Numerous tornado outbreak events are likely.

Find your state region to get updates for your state by clicking here.

As the upper jet stream starts to react to the closing season, troughs will dig further into California, thus the surface lows should form in Colorado and Kansas, bringing with it the perfect setup for violent tornado outbreaks.  This is the seventh year of prediction made here at TheWeatherSpace.com about the tornado season.  All predictions have been accurate, including the tornado drought in the plains a couple years back.  This year will not feature a death ridge.

A death ridge is when a ridge of high pressure sets up over the Western United States, owning to a northwest flow into the region with no upper divergence or colder air aloft to push supercells off.  This has happened a couple times in the seven year prediction period done on this site.

This year, however, is not a death ridge, but one where a trough should set-up end April into May across the Western United States.   Impulses riding that into the Great Plains will bring the perfect ingredients for tornadoes … and since the jet may be in perfect orientation for these events, outbreaks are likely …

from:    http://www.theweatherspace.com/2014/04/10/tornado-alley-to-be-active-this-season-with-a-number-of-outbreaks/

The PEEPonauts

Thursday, April 24th, 2014

PEEP-O-NAUTS TAKE RISKY TRIP TO THE EDGE OF SPACE: On April 20th, the students of Earth to Sky Calculus launched a pair of suborbital helium balloons to the stratosphere. One payload carried a radiation sensor to measure the effects of the Easter geomagnetic storm on Earth’s upper atmosphere. The other payload carried a colony of halobacteria in an experiment to find out if the extremophiles could live at the edge of space. In honor of the holiday, the students launched some peeps as halobacteria companions. As this movie shows, it’s risky being a peep-o-naut:

The near-miss only 2000 ft. above the launch site almost brought an explosive end to the mission. Fortunately, the two balloons carried on to the stratosphere, gathering data on the solar storm in progress during the flight. Here is what peeps look like at the edge of space. Later, the peeps and halobacteria parachuted to Earth, landing in a tree in the Inyo Mountains of central California.

from:    spaceweather.com

Jeff Masters on California Drought

Sunday, February 2nd, 2014

California’s Sierra Snowpack Only 12% of Average, a Record Low

By Dr. Jeff Masters
Published: 4:32 PM GMT on January 31, 2014

California’s first significant snow storm of 2014 hit the Sierras on Wednesday and Thursday, dumping up to 2 feet of snow, with a melted water equivalent of up to two inches. However, this modest snowstorm was not enough to keep the Sierra snowpack from recording its lowest snow amounts in more than 50 years of record keeping during Thursday’s Sierra Snow Survey. The survey found a snow pack that was only 12% of normal for this time of year. Until Thursday, the lowest statewide snowpack measurement at this time of year was 21% of average, in 1991 and 1963, according to the Los Angeles Times. Since snowpack in the Sierras forms a crucial source of water for California, the dismal snow survey results are a huge concern.


Figure 1. Frank Gehrke, chief of the California Cooperative Snow Survey Program for the Department of Water Resources, walks leaves a snow covered meadow after the second snow survey of the year near Echo Summit, Calif., Thursday, Jan. 30, 2014. Despite the overnight snow storm the survey showed the snow depth at 12.4 inches with a water content of only 1.4 inches for this location at this time of the year. Gehrke said that while the recent snow fall will help, it is not enough to impact the water supply.(AP Photo)

The forecast: little drought relief in sight
One of the most persistent and intense ridges of high pressure ever recorded in North America has been anchored over the West Coast since December 2012. While the ridge has occasionally broken down and allowed low pressure systems to leak though, these storms have mostly brought spotty and meager precipitation to California, resulting in California’s driest year on record during 2013. January 2014 could well be its driest January on record. The ridge inevitably builds back after each storm, clamping down on any moisture reaching the state. Since rain-bearing low pressure systems tend to travel along the axis of the jet stream, these storms are being carried along the axis of the ridge, well to the north of California and into Southeast Alaska, leaving California exceptionally dry. The latest runs of the GFS and European models show that the ridge is now building back, and it appears likely that California will see no significant precipitation until at least February 7. A weak upper level low will move along the coast on Sunday and spread some light rain along the immediate coast, but this precipitation will generally be less than 0.25″–too little to have any significant impact on the drought. The ridge will not be as intense when it builds back, though, which gives me some hope that a low pressure system will be able to break the ridge by mid-February and bring the most significant rains of the winter rainy season to California.


Figure 2. One of the key water supply reservoirs for Central California, Lake Oroville, as seen on January 20, 2014. Image credit: California Department of Water Resources.

Worst California drought in 500 years?
UC Berkeley paleoclimatologist B. Lynn Ingram, author of “The West Without Water: What Past Floods, Droughts, and Other Climatic Clues Tell Us About Tomorrow”, said in an interview, “this could potentially be the driest water year in 500 years.” Her research on tree rings shows that California has not experienced such an extreme drought since 1580. “If you go back thousands of years, you see that droughts can go on for years if not decades, and there were some dry periods that lasted over a century, like during the Medieval period and the middle Holocene. The 20th century was unusually mild here, in the sense that the droughts weren’t as severe as in the past. It was a wetter century, and a lot of our development has been based on that.” It’s no wonder, then, that the overall agricultural impact of the drought could reach $1 billion this year, according to the Fresno-based Westlands Water District.

California’s drought woes are part of an on-going 14-year Western U.S. drought that began in 2000, and peaked between 2000 – 2004. A 2012 study titled, Reduction in carbon uptake during turn of the century drought in western North America, found that the 2000 – 2004 drought was the most severe Western North America event of its kind since the last mega drought over 800 years ago, during the years 1146 – 1151. The paper analyzed the latest generation of climate models used for the 2013 IPCC report, which project that the weather conditions that spawned the 2000 – 2004 drought will be the new normal in the Western U.S. by 2030, and will be considered extremely wet by the year 2100. If these dire predictions of a coming “megadrought” are anywhere close to correct, it will be extremely challenging for the Southwest U.S. to support a growing population in the coming decades.

Megadroughts in the Western U.S. can develop from natural causes, as well, and the current pattern of cooler than average ocean temperatures in the Eastern Pacific and warmer than average ocean temperatures in the Atlantic increase the odds of drought conditions like the ones we have seen during the current megadrought. Edward Cook, director of the Tree Ring Laboratory at Columbia University’s Lamont-Doherty Earth Observatory in Palisades, N.Y., said at a presentation last month at the American Geophysical Union meeting that tree ring data show that the area of the West that was affected by severe drought in the Medieval period was much higher and much longer than the current drought. It is “indeed pretty scary,” Cook said. “One lasted 29 years. One lasted 28 years. They span the entire continental United States.” Two megadroughts in the Sierra Nevada of California lasted between 100 and 200 years. Bobby Magill at Climate Center has more on Dr. Cook’s presentation in a post, Is the West’s Dry Spell Really a Megadrought?

Figure 3. Normalized precipitation over Western North America (five-year mean) from 22 climate models used to formulate the 2013 IPCC report, as summarized by Schwalm et al., 2012, Reduction in carbon uptake during turn of the century drought in western North America. The horizontal line marks the precipitation level of the 2000 – 2004 drought, the worst of the past 800 years. Droughts of this intensity are predicted to be the new normal by 2030, and will be considered an outlier of extreme wetness by 2100. The paper states: “This impending drydown of western North America is consistent with present trends in snowpack decline as well as expected in-creases in aridity and extreme climate events,including drought, and is driven by anthropogenically forced increases in temperature with coincident increases in evapotranspiration and decreases in soil moisture. Although regional precipitation patterns are difficult to forecast, climate models tend to underestimate the extent and severity of drought relative to available observations. As such, actual reductions in precipitation may be greater than shown. Forecasted precipitation patterns are consistent with a probable twenty-first century megadrought.” Image credit: Schwalm et al., 2012, Reduction in carbon uptake during turn of the century drought in western North America, Nature Geoscience 5, 551-555, Published online 29 JULY 2012, DOI: 10.1038/NGEO1529, www.nature.com/naturegeoscience.

Related posts
Unprecedented Cut in Colorado River Flow Ordered, Due to Drought, my August 2013 post.

Lessons from 2012: Droughts, not Hurricanes, are the Greater Danger, my November 2012 post.

How Two Reservoirs Have Become Billboards For What Climate Change Is Doing To The American West, August 12, 2013 climateprogress.org post by Tom Kenworthy.

Scientists Predicted A Decade Ago Arctic Ice Loss Would Worsen Western Droughts. Is That Happening Already?, June 2013 post by Joe Romm at climateprogress.org.

Twenty Cities At Risk of Water Shortages, August 14, 2013 wunderground news post by Nick Wiltgen

‪If There’s Global Warming…Why Is It So Cold?‬
It’s been top-ten coldest January on record in the Upper Midwest, and much colder than average over much of the Eastern U.S. However, the that isn’t the case over other portions of the globe, including the Western U.S. and Alaska. Wunderground’s weather historian Christopher C. Burt analyzes the situation in his latest post, How Cold has this January been in the U.S.? He concludes, “this January’s average temperature nationally has probably been close to normal since the western half of the nation has been almost as much above average as the eastern half was below average. The only region that will most likely have experienced a TOP 10 coldest January will be the Upper Midwest.” In the U.S., only four stations set all-time low minimum temperature records in January, compared to 34 that set all-time high maximum temperature records. I’ve been monitoring global temperatures this month, and it appears likely that January will rank between the 5th and 15th warmest January since record keeping began in 1880. Of particular note were the amazingly warm January temperatures in the Balkans. According to weather record researcher Maximiliano Herrera, “over 90% of all stations in the Balkans from Slovenia to Croatia to Bosnia to Serbia To Montenegro to Kosovo etc., have DESTROYED their previous record of warmest January ever (many locations have 100 – 200 years of data.) In many cases the monthly temperatures were 7 – 9°C (13 – 16°F) above average, and the new records were 3 – 4°C above the previous record. This is for THOUSANDS of stations, almost all of them. In Slovenia, for example, Mount Kredarica is the only station in the whole country not to have set its warmest January on record.”

Video 1. ‪If There’s Global Warming … Why Is It So Cold?‬ The latest video from climate videographer Peter Sinclair on the Yale Climate Forum website demonstrates that while it was a very cold January in the Midwest, this has been counterbalanced by record warmth over the Western U.S. and Alaska, caused by an unusually extreme kink in the jet stream.

Links
Another Unexpected Disaster That Was Well Forecast. Based in Atlanta, TWC’s Bryan Norcross concludes that “WARM GROUND + VERY COLD AIR + SNOW + WORKDAY = CHAOS. If the decision-makers understood the formula above, this information should have been sufficient to trigger a proper response.”

Jon Stewart Lays Into Georgia’s Snowpocalypse

from:    http://www.wunderground.com/blog/JeffMasters/article.html?entrynum=2624

2013 Heat Records

Monday, January 20th, 2014
Nine Nations or Territories Set All-Time Heat Records in 2013
By: Dr. Jeff Masters, 2:43 PM GMT on January 20, 2014 +23

It was another notable year for all-time heat records in 2013, with six nations and three territories tying or setting records for hottest temperature on record. No nations set an all-time cold record in 2013. For comparison, five countries and two territories set all-time hottest temperature records in 2012, and the most all-time national heat records in a year was twenty nations and one territory in 2010. Since 2010, 45 nations or territories have set or tied all-time heat records, but only one nation has set an all-time cold temperature record. Since each of those years ranked as one of the top eleven warmest years in Earth’s history, and 2010 was the warmest year on record, this sort of disparity in national heat and cold records is to be expected. Most nations do not maintain official databases of extreme temperature records, the national temperature records I report here are in many cases not official. I use as my source for international weather records Maximiliano Herrera, one of the world’s top climatologists, who maintains a comprehensive list of extreme temperature records for every nation in the world on his website. If you reproduce this list of extremes, please cite Maximiliano Herrera as the primary source of the weather records. Wunderground’s weather historian Christopher C. Burt maintains a database of these national heat and cold records, for 235 nations and territories, on wunderground.com’s extremes page.


Figure 1. A moose takes a dip to cool off in a backyard pool in this photo taken in Big Lake, Alaska on June 17, 2013, by Lonea Moore McGowen (Courtesy KTUU-TV.) Bentalit Lodge, Alaska hit 36.7°C (98°F) on June 17, tying the mark set in Richardson on 15 June 1969 for hottest undisputed temperature in Alaska history. The official heat record for Alaska remains the 100°F registered at Fort Yukon on June 27, 1915. However, there are questions concerning this figure as outlined by our weather historian, Christopher C. Burt.

New all-time national heat records set in 2013

Heard and McDonald Islands (uninhabited territory of Australia) set a new all-time heat record of 26.1°C (79°F) at Split Bay on 1 March. Previous record: 21.6°C set at the same station in April 1992.

Ghana tied its all time highest temperature record with 43.0°C (109.4°F) at Navrongo on 6 March; the same value had also been recorded on 25 February 2010 and 19 April 2010 at the same location.

The United States tied its highest undisputed temperature at the Furnace Creek Visitors Center, Death Valley California, with 53.9°C (129°F) on 30 June. The only higher temperatures ever recorded on the planet occurred in Death Valley on July 10, 12, and 13, 1913, when readings of 134°F, 130°F, and 131°F were recorded. These 100-year-old official hottest temperatures in Earth’s history have many doubters, though, including Mr. Burt, who noted in a 2010 blog post that “The record has been scrutinized perhaps more than any other in the United States. I don’t have much more to add to the debate aside from my belief it is most likely not a valid reading when one looks at all the evidence.

St. Pierre et Miquelon, a French territory off the coast of Newfoundland, Canada, set its all time highest temperature record with 28.3°C (82.9°F) at the St. Pierre Airport on 6 July. Previous record: 28.0°C at St. Pierre town in August 1876 and August 1935.

Greenland, a territory of Denmark, set a new all time highest temperature with 25.9°C (78.6°F) at Maniitsoq Airport on 30 July. Previous record: 25.5°C at Kangerlussuaq on 27 July 1990. There is a claimed 30.1°C measurement at Ivigtut on 23 June 1915, but this is almost certainly a mistake, since the reading doesn’t fit at all with the hourly data of that day, and the station in over a century has never recorded any temperature above 24°C.

Austria set a new national record of highest temperature with 39.9°C (103.8°F) at Dellach im Drautal on 3 August, which beat the old record of 39.7°C set at the same location on 27 July 1983. The 3 August 2013 record was beaten again on 8 August 2013, with a 40.5°C (104.9°F) reading recorded at Bad Deutsch-Altenburg.

Slovenia also set a new all time heat record on 8 August, with 40.8°C at Cerklje Ob krki. Previous record: 40.6°C set at Crnomelj on 5 July 1950.

Japan set a new all-time heat record with 41.0°C (105.8°F) at Shimanto on 12 August. Previous record: 40.9°C at Tajimi and at Kumagaya on 16 August 2007.

Comoros tied its national record of highest temperature at the Hahaya Int. Airport with 35.6°C (96.1°F) on 19 November; the same value was recorded at the former Moroni Airport (its location looks to have been very close of the current international airport) on 31 December 1960.


Figure 2. The official Furnace Creek, Death Valley maximum recording thermometer for the maximum temperature measured on June 30th, 2013. The 129.2°F (54.0°C) reading was the highest June temperature ever measured on Earth. Photo courtesy of Death Valley National Park and NWS-Las Vegas. Note, though, since only whole Fahrenheit figures are official in the U.S., the value was registered as 129°F.

Notable global heat and cold records set in 2013
Hottest temperature in the world in 2013: 53.9°C (129°F) at Death Valley, California, June 30
Coldest temperature in the world in 2013: -81.7°C (-115°F) at Dome A, Antarctica, July 31
Hottest temperature in the Southern Hemisphere: 49.6°C (121.3°F) at Moomba Aero, Australia, January 12
Coldest temperature in the Northern Hemisphere: -64.2°C (-83.6°F) at Summit GEO, Greenland, March 4

Number of major world stations which set their all time highest temperature in 2013: 389
Number of major world stations which set their all time lowest temperature in 2013: 12

On 27 February, 2013, a new February all-time heat record for the Northern Hemisphere was set with 44.5°C (112.1°F) at Abu Na’ Ama (Sudan). Previous record: 44.4°C with two former record holders: Kayes in Mali, and Kiffa in Mauritania.

A day for the history books: European heat wave of 8 August 2013
An incredible heat wave over Central Europe on 8 August 2013 was a day for the history books of world climatology, with two nations and three world capitals setting all-time heat records on the same day. Dozens of stations in six European countries also set all-time heat records that day. The three capitals that set new all-time heat records on 8 August:

Vienna, Austria reached 39.5°C (103.1°F), beating the previous city record of 38.9°C which was recorded in July 1957.

Bratislava, Slovakia reached 39.4°C (102.9°F), beating the previous city record of 38.9°C set in July 2007.

Ljubljana, Slovenia reached as high as 40.2°C (104.4°F), beating for the FIFTH TIME IN SIX DAYS the old record of 38.0°C set in June 1935. This is particularly amazing, since the city has about 150 years of data. This is the sequence:

3 August 38.3°C
4 August 38.4°C
6 August 38.6°C
7 August 39.5°C
8 August 40.2°C

One other world capital set an all-time heat record in 2013: Bangkok, Thailand, which reached 40.1°C (104.2°F) in the Metropolis Station on 26 March, beating the previous record of 40.0°C set in April 1979 and April 2012.

A big thanks goes to Maximiliano Herrera for providing the information in this post.

from:    http://www.wunderground.com/blog/JeffMasters/show.html

Winter Forecast fr/The Weather Space

Thursday, October 24th, 2013

2013 – 2014 Winter Forecast Released From TheWeatherSpace.com

tws1314seasonmonth

NOTE: The ONLY Way Above Normal is CALIFORNIA for Precipitation … It is not the orange color in the Eastern USA … Orange is Below normal precip!

NOTE: This is the AVERAGE of all three months, Dec/Jan/Feb …

Dec – nationwide warm
Jan – Warm west, cold east
Feb – nationwide warm

Discussion:  Storm pattern for this does not begin till December so anything before this does not count.  During the main winter season of December, January, and February we will see most of he USA under above average temperatures.  With an active southern jet stream and split flow pattern over the Pacific Northwest, this looks to bring the storm track across the Southern USA, impacting California with above average precipitation.  Although this is not an El Nino year, this forecast is made by other means not disclosed.

The active southern branch of the jet will bring above average temperatures to most of the country, with the exception of the extreme Northeastern part from New England through Maine where temperatures will be below normal with an active snow track.

Areas across Texas and into Florida will be in this southern branch jet stream, which means that a number of strong surface lows will develop and bring above average precipitation to both states.  In fact, this pattern brings severe thunderstorms and tornadoes to Florida, and possibly another March 1993 type event.

Furthermore the storm track will go from Florida up through the New England / Northeastern USA.  Despite being above average in temperatures for the season, cold shots will always be likely and one or two storms may become strong nor’easters as this pattern favors such …

The pattern brings surface lows through KS/MO/IA for Blizzard Conditions across Nebraska, South Dakota, North Dakota, and Minnesota.  This will become the norm if lows branch off at the surface from the southern branch jet stream.

The pattern also favors normal temperatures for the Pacific Northwest, with normal rainfall … some areas will see below normal rainfall in those spots though.  This season does not favor an active storm season for the Pacific Northwest.

from:    http://www.theweatherspace.com/2013/10/14/2013-2014-winter-forecast-released-from-theweatherspace-com/

Dr. Masters on August 2013 Extremes

Tuesday, September 24th, 2013

August 2013 was the globe’s 4th warmest August since records began in 1880, according to NOAA’s National Climatic Data Center (NCDC). NASA rated it the 5th warmest August on record. The year-to-date period of January – August has been the 6th warmest such period on record. August 2013 global land temperatures were the 11th warmest on record, and global ocean temperatures were the 5th warmest on record. August 2013 was the 342nd consecutive month with global temperatures warmer than the 20th century average. Global satellite-measured temperatures in August 2013 for the lowest 8 km of the atmosphere were 14th or 11th warmest in the 35-year record, according to Remote Sensing Systems and the University of Alabama Huntsville (UAH), respectively. Wunderground’s weather historian, Christopher C. Burt, has a comprehensive post on the notable weather events of August 2013 in his August 2013 Global Weather Extremes Summary. The big stories that he highlights are the intense heat waves that hit Central Europe and East Asia, which brought all-time national heat records to Austria, Slovenia, and Japan. Ljubljana, the capital of Slovenia, passed its all-time heat record a remarkable five times during the month.


Figure 1. Departure of temperature from average for August 2013, the 4th warmest August for the globe since record keeping began in 1880. Most of the world’s land areas experienced warmer-than-average monthly temperatures, including Australia, northern South America, western North America, Europe, and much of eastern Asia. Far eastern China, part of eastern Russia north of Japan, and part of northeastern South America were record warm for the month. The southeastern United States, Far East Russia, part of South Africa, Paraguay, and Bolivia were cooler than average. No regions of the globe were record cold. Image credit: National Climatic Data Center (NCDC) .

The six billion-dollar weather disasters of August 2013


Disaster 1. The most damaging billion-dollar weather disaster of August was in Northeast China, where the Nei River overflowed, killing 54 and leaving 97 missing in Fushuan. The flooding killed 118 people and cost $5 billion. In this photo, workers use an excavator to clean up mud after heavy rain hit on August 19, 2013 in Fushuan, in the Liaoning Province of China. Photo by ChinaFotoPress/Getty Images.

Disaster 2. Super Typhoon Utor killed 70 people in China and did $2.6 billion in damage. Utor also did $33 million in damage in the Philippines. This video taken by storm chaser James Reynolds shows debris flying as Typhoon Utor hits Zhapo, China on 14th August 2013.


Disaster 3. Torrential rains, due, in part, to moisture from Typhoon Trami, fell in the Philippines August 18 – 21, causing massive flooding on Luzon Island that cost $2.2 billion. Twenty-seven people were killed, and 60% of metro Manila was under water at the peak of the flood. According to EM-DAT, the International Disaster Database, this was the most expensive natural disaster in Philippine history. In this photo, pedicabs and makeshift rafts ferry office workers and pedestrians through flood waters that submerged parts of the financial district of Makati on August 20, 2013 in Makati City south of Manila, Philippines. Image credit: Dondi Tawatao/Getty Images)


Disaster 4. In Pakistan, torrential monsoon rains caused significant flooding that affected 5,739 villages. At least 208 people were killed, 63,180 homes were damaged or destroyed, and 1.4 million acres (567,000 hectares) of crops were submerged. The government estimated economic agricultural losses alone at $1.9 billion. Pakistan’s four most expensive weather-related disasters in its history have been floods that occurred in the past four consecutive years. In this photo, Pakistani residents hold onto a rope as they evacuate a flooded area in Karachi on August 4, 2013. Image credit: Asif Hassan/AFP/Getty Images)


Figure 5. Russia experienced its costliest flood disaster in history beginning on August 4, when the Amur and Zeya rivers in the far east of the country along the Chinese border overflowed, flooding 1.7 million acres, damaging or destroying over 11,500 buildings. It was the 4th most expensive natural disaster of any kind in Russian history. These false-color infrared satellite images of Russia’s Amur River taken a little over a year apart show the extent of the extreme flooding that affected the Komsomolsk-on-Amur area (population 500,000) in August 2013. Image credit: NASA.


Disaster 6. A severe weather outbreak in the U.S. Plains and Midwest August 5 – 7 brought baseball sized hail and thunderstorm wind gusts over 80 mph to Minnesota and Wisconsin. Two people were killed, and damage was estimated at $1 billion. In this photo, a severe thunderstorm closes in on Edgemont, South Dakota, on August 7, 2013. Image credit: wunderphotographer ninjalynn.

The world-wide tally of billion-dollar weather disasters so far in 2013 is 25, and the U.S. total is six, according to the August 2013 Catastrophe Report from insurance broker Aon Benfield. This excludes the September Colorado flood, whose damages are preliminarily estimated at $2 billion. Ranked in term of cost, here are the 25 disasters:

1) Flooding, Central Europe, 5/30 – 6/6, $22 billion
2) Drought, Brazil, 1/1 – 5/31, $8.3 billion
3) Drought, Central and Eastern China, 1/1 – 7/31, $6.0 billion
4) Flooding, Calgary, Alberta Canada, 6/19 – 6/24, $5.3 billion
5) Flooding, China, 8/9 – 9/5, $5.0 billion
6) Tornado, Moore, OK, and associated U.S. severe weather, 5/18 – 5/22, $4.5 billion
6) Flooding, China, 7/7 – 7/17, $4.5 billion
8) Flooding, Indonesia, 1/20 – 1/27, $3.31 billion
9) Super Typhoon Utor, China and Philippines, 8/12 – 8/15, $2.6 billion
10) Flooding, Australia, 1/21 – 1/30, $2.5 billion
11) Flooding, Philippines, 8/18 – 8/21, $2.2 billion
12 Tornadoes and severe weather, U.S., 5/26 – 6/2, $2 billion
12) Severe weather, Midwest U.S., 3/18 – 3/20, $2 billion
14) Flooding, Pakistan and Afghanistan, 8/3 – 8/31, $1.9 billion
15) Winter weather, Europe, 3/12 – 3/31, $1.8 billion
16) Drought, New Zealand, 1/1 – 5/10, $1.6 billion
16) Severe weather, U.S., 4/7 – 4/11, $1.6 billion
18) Flooding, Toronto, Canada, 7/8, $1.45 billion
19) Flooding, China, 6/29 – 7/3, $1.4 billion
19) Flooding, China, 7/21 – 7/25, $1.4 billion
21) Flooding, Argentina, 4/2 – 4/4, $1.3 billion
22) Flooding, India and Nepal, 6/14 – 6/18, $1.1 billion
23) Winter weather, U.S. Plains, Midwest, Northeast, 2/24 – 2/27, $1.0 billion
23) Severe weather, U.S. Plains and Midwest, 8/5 – 8/7, $1.0 billion
23) Flooding, Russia, 8/4 – 8/31, $1.0 billion

Neutral El Niño conditions continue in the equatorial Pacific
For the 17th month in row, neutral El Niño conditions existed in the equatorial Pacific during August 2013. NOAA’s Climate Prediction Center (CPC) expects neutral El Niño conditions to last though the winter of 2013 – 2014, and the large majority of the El Niño models also predict that neutral conditions will last through the winter. Temperatures in the equatorial Eastern Pacific need to be 0.5°C below average or cooler for three consecutive months for a La Niña episode to be declared; sea surface temperatures were 0.0°C from average as of September 16, and have been +0.1 to -0.4°C from average since April 1, 2013.

Arctic sea ice falls to 6th lowest August extent on record
Arctic sea ice extent during August was 6th lowest in the 35-year satellite record, according to the National Snow and Ice Data Center (NSIDC). This was the largest August extent since 2009, and a nice change of pace from last year’s all-time record retreat. The Arctic sea ice reached its minimum extent for the year on September 13, and has now begun re-freezing. I’ll have a dedicated post on this, probably on Tuesday.

Quiet in the Atlantic
In the Gulf of Mexico, the tail end of a cold front off the coast of Texas has developed a few disorganized heavy thunderstorms. This disturbance has some modest spin to it, thanks to absorbing Invest 95L on Saturday. However, wind shear is high, 20 – 30 knots, and I don’t expect this disturbance will develop. The disturbance is expected to bring 1 – 3″ of rain to Florida later this week, and on Saturday, the Army Corps of Engineers has re-opened the flood gates on Lake Okeechobee to dump water out of the lake in anticipation of the heavy rains. None the reliable models for tropical cyclone formation is predicting development during the coming five days.

In the Western Pacific, Typhoon Usagi has dissipated after hitting China about 100 miles east-northeast of Hong Kong. The storm is being blamed for at least 25 deaths in China and 2 in the Philippines. Preliminary damage estimates are over $500 million.

Jeff Masters

from:    http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2531

August Hurricane Potential

Thursday, August 1st, 2013

A massive dust storm that formed over the Sahara Desert early this week has now pushed out over the tropical Atlantic, and will sharply reduce the odds of tropical storm formation during the first week of August. The dust is accompanied by a large amount of dry air, which is making the Saharan Air Layer (SAL) much drier than usual this week. June and July are the peak months for dust storms in the Southwest Sahara, and this week’s dust storm is a typical one for this time of year. Due in large part to all the dry and dusty air predicted to dominate the tropical Atlantic over the next seven days, none of the reliable computer models is predicting Atlantic tropical cyclone formation during the first week of August.


Figure 1. A massive dust storm moves off the coast of Africa in this MODIS image taken at 1:40 UTC July 30, 2013. Image credit: NASA.

Video 1. The predicted movement through August 3 of this week’s Africam dust storm, using the NOAA NGAC aerosol model. Image credit: NOAA Visualization Laboratory.

How dust affects hurricanes
Saharan dust can affect hurricane activity in several ways:

1) Dust acts as a shield which keeps sunlight from reaching the surface. Thus, large amounts of dust can keep the sea surface temperatures up to 1°C cooler than average in the hurricane Main Development Region (MDR) from the coast of Africa to the Caribbean, providing hurricanes with less energy to form and grow. Ocean temperatures in the MDR are currently 0.7°F above average, and this anomaly should cool this week as the dust blocks sunlight.

2) The Saharan Air Layer (SAL) is a layer of dry, dusty Saharan air that rides up over the low-level moist air over the tropical Atlantic. At the boundary between the SAL and low-level moist air where the trade winds blow is the trade wind inversion–a region of the atmosphere where the temperature increases with height. Since atmospheric temperature normally decreases with height, this “inversion” acts to but the brakes on any thunderstorms that try to punch through it. This happens because the air in a thunderstorm’s updraft suddenly encounters a region where the updraft air is cooler and less buoyant than the surrounding air, and thus will not be able to keep moving upward. The dust in the SAL absorbs solar radiation, which heats the air in the trade wind inversion. This makes the inversion stronger, which inhibits the thunderstorms that power a hurricane.

3) Dust may also act to produce more clouds, but this effect needs much more study. If the dust particles are of the right size to serve as “condensation nuclei”–centers around which raindrops can form and grow–the dust can act to make more clouds. Thus, dust could potentially aid in the formation and intensification of hurricanes. However, if the dust acts to make more low-level clouds over the tropical Atlantic, this will reduce the amount of sunlight reaching the ocean, cooling the sea surface temperatures and discouraging hurricane formation (Kaufman et al., 2005.)


Figure 2. Map of the mean summer dust optical thickness derived from satellite measurements between 1979 and 2000. Maximum dust amounts originate in the northern Sahel (15° to 18° N) and the Sahara (18° to 22° N). The Bodele depression in Chad is also an active dust source. Image credit: Evidence of the control of summer atmospheric transport of African dust over the Atlantic by Sahel sources from TOMS satellites (1979-2000), by C. Moulin and I. Chiapello, published in January 2004 in Geophysical Research Letters.

Dust in Africa’s Sahel region and Atlantic hurricane activity
The summertime dust that affects Atlantic tropical storms originates over the southwestern Sahara (18° – 22° N) and the northwestern Sahel (15° – 18° N) (Figure 3.) The dust from the Southwest Sahara stays relatively constant from year to year, but the dust from the Northwest Sahel varies significantly, so understanding this variation may be a key factor in improving our forecasts of seasonal hurricane activity in the Atlantic. The amount of dust that gets transported over the Atlantic depends on a mix of three main factors: the large scale and local scale weather patterns (windy weather transports more dust), how wet the current rainy season is (wet weather will wash out dust before it gets transported over the Atlantic), and how dry and drought-damaged the soil is. The level of drought experienced in the northwestern Sahel during the previous year is the key factor of the three in determining how much dust gets transported over the Atlantic during hurricane season, according to a January 2004 study published in Geophysical Research Letters published by C. Moulin and I. Chiapello. In 2012 (Figure 3), precipitation across the northwestern Sahel was much above average, which should result in less dust than usual over the Atlantic this fall, increasing the odds of a busy 2013 hurricane season.


Figure 3. Rainfall over the Northwest Sahel region of Africa was about 200% of average during the 2012 rainy season. The heavy rains promoted vigorous vegetation growth in 2013, resulting in less bare ground capable of generating dust. Image credit: NOAA/Climate Prediction Center.

Links
Saharan Air Layer Analysis from the University of Wisconsin

Atlantic dust forecast from the Tel-Aviv University Weather Research Center

Dr. Amato Evan published a study in Science magazine March 2009 showing that 69% of the increase in Atlantic sea surface temperatures over the past 26 years could be attributed to decreases in the amount of dust in the atmosphere.

Kaufman, Y. J., I. Koren, L. A. Remer, D. Rosenfeld, and Y. Rudich, 2005a: The effect of smoke, dust, and pollution aerosol on shallow cloud development over the Atlantic Ocean. Proc. Natl. Acad. Sci. USA, 102, 11 207–11 212.

Wang, Chunzai, Shenfu Dong, Amato T. Evan, Gregory R. Foltz, Sang-Ki Lee, 2012, Multidecadal Covariability of North Atlantic Sea Surface Temperature, African Dust, Sahel Rainfall, and Atlantic Hurricanes, J. Climate, 25, 5404–5415.
doi: http://dx.doi.org/10.1175/JCLI-D-11-00413.1

from:    http://www.wunderground.com/blog/JeffMasters/show.html