The weather pattern responsible for bringing frigid air to Europe, like this heavy snow fall on the Colosseum in Rome, is driven in part by a naturally-occurring pattern known as the Arctic Oscillation.

While the U.S. cruises through winter with a snow drought and above-average temperatures, much of Europe and Eurasia are locked in the grips of a deadly cold air outbreak, with more than 300 people reported dead so far. According to news reports, entire communities in Italy, Bosnia, and Romania have become inaccessible due to heavy snowfall and power outages. According to Sky News, a dam in Bulgaria burst due to the combination of snowmelt and heavy rains, killing four people in a village downstream, and other dams in Southeastern Europe are also being threatened. Bosnia, Serbia, Macedonia and Turkey are at risk for heavy snows during the next few days. 

According to U.S. News and World Report, the wintry blitz presents a poorly-timed challenge to European economies, which already are struggling to contain a debt crisis: 

“In more robust economic times, the economic effects of bad weather might be nothing more than bump in the road, but in a place already teetering on the brink of recession, the stakes are higher.”

“[E]ven relatively limited disruption from snow and freezing conditions could very well be enough to tip the balance towards the economy suffering further contraction in the first quarter of this year, which would put it officially back into recession,” writes Howard Archer, chief European and UK economist of IHS Global Insight, in a commentary on the cold snap.

According to Bloomberg News, 93 stations from the Czech Hydrometeorological Institute reported the lowest-ever temperatures for February 5, with one station bottoming out near -38°F. In Ukraine, the cold has killed at least 131 people, and nearly 2,000 were hospitalized due to hypothermia

Ice has forced Austria to close the Danube river to navigation, shutting down access to part of the second-longest river in Europe. In addition, the iconic canals of Venice were reported to be frozen as well.

What’s Going On?

The departures from average of the height of the 500 mb pressure surface from Jan. 28 to Feb. 3, 2012. The red colors near Norway indicate unusually warm air at the mid-levels of the atmosphere (high heights). Dark blue shading across Europe and Eurasia shows telltale signs of colder than average conditions (low heights). Credit: NOAA/ESRL.

The weather pattern responsible for bringing the frigid air to Europe and Eurasia, and locking it in place, is being driven in part by a naturally-occurring pattern of climate variability known as the Arctic Oscillation. Depending on whether it’s in a “positive” or “negative” phase, the Arctic Oscillation can bring warmer or cooler than average wintertime conditions to the U.S. and Europe.

Right now the Arctic Oscillation is in a negative phase, which tends to favor colder than average weather in Europe and the U.S. Scientists don’t fully understand what causes the Arctic Oscillation to switch from one phase to the other, which limits their ability to forecast these changes ahead of time beyond a week in advance.

Stu Ostro, a senior meteorologist at The Weather Channel who has been keeping close tabs on trends in weather and climate extremes in recent years, said the frigid weather in Europe is another in a series of weird winters that have been related to the Arctic Oscillation.

“It’s interesting that the winter started out the opposite of the previous two, with an exceptionally positive Arctic Oscillation and non-blocking pattern, and then it flipped,” he said via email.

Map showing sea level pressure departures from average during the last week in January through early February. The bright red area over Russia and parts of Europe indicate the presence of an unusually strong high pressure area. Credit: NOAA/ESRL.

Map showing surface wind departures from average during the same period. The circle and arrows show how the frigid air from Russia has flowed westward, into much of Europe. Credit: NOAA/ESRL.

“There has been extreme variability of the Arctic Oscillation in recent years, including a record negative monthly value for December in 2009 (the month of the so-called “Snowpocalypse” in the northeast U.S.), a record negative for any month in February 2010 (“Snowmageddon”), and a record positive one for April in 2011 (coinciding with the extraordinary number of tornadoes in the U.S. that month),” Ostro said. “And this has been occurring in the context of the precipitous decline of Arctic sea ice volume.”

Also noteworthy is a very strong and persistent high pressure area that has been sprawled across Russia. The airflow around this stubborn high has been transporting Siberian air into Western Europe, as the maps below show.

As Ostro alluded to, in recent years there have been studies examining how the global warming-related loss of Arctic sea ice might affect winter weather patterns in the northern hemisphere. Some of this research shows that sea ice loss may favor winters with predominately negative phases of the Arctic Oscillation. One potential result of global warming, referred to as the “Arctic Paradox,” is that sea ice loss can help warm the Arctic during the winter, while setting in motion a chain reaction of events that make winters colder than they otherwise would be in Europe and the U.S.. 

The weather pattern during the past two weeks bears some similarities to conditions last December, when the Arctic Oscillation was in an extremely negative phase, and the jet stream helped drive frigid air and winter storms into both Europe and the U.S. This year, though, only Europe and Eurasia have been unusually cold, as other factors have conspired to protect the Lower 48 from Old Man Winter’s wrath. At least for now, anyway, as there are signs this may change during the next few weeks.

Figure 1. The scene in Tripoli, Libya, on February 6, 2012, after a rare snowstorm. Image credit: libyall.com.

Unusual jet stream kink causing Europe’s harsh winter weather
The reason for the exceptionally cold and snowy winter weather in Europe lies in the behavior of the jet stream. The jet stream–the band of strong west-to-east blowing upper-level winds that circles the globe at mid-latitudes–acts as the dividing line between cold, polar air to the north, and warmer subtropical air to the south. On average, the jet blows straight west to east. But this winter, the jet has had a highly convoluted shape, with unusually large excursions to the north and south. When the jet bulges southwards, it allows cold air to spill in behind it, and that is what has happened to Europe over the past two weeks. The jet often gets “stuck” in one of these highly convoluted shapes, allowing a persistent period of extreme weather to occur. The latest predictions from the GFS and ECMWF models show the unusual jet stream pattern over Europe persisting for at least another week.

Figure 2. The jet stream pattern over Europe shows that the jet is taking a major dive southwards across France and into North Africa, keeping almost all of Europe on the cold (north) side of the jet.

The AO and NAO
A good measure of the tendency of the jet to form major bulges in winter is the Arctic Oscillation (AO) Index, which has ranged between -1 and -3 over the past two weeks. A strongly negative AO Index like this means the winds of the jet are relatively weak, allowing it to sag southwards over Europe and allow cold air to plunge southwards behind it. Usually, a negative AO also means cold winter weather over North America, but not this winter. In North America, we’re better off paying attention to the North Atlantic Oscillation (NAO) Index, which we can think of as the Northern Atlantic portion of the AO. Ordinarily, the AO and NAO are in phase during winter (about 80 – 90% of the time), meaning that Europe and North America experience similar winter weather. However, over the past two weeks, the NAO has been positive while the AO has been negative. The positive NAO means that jet stream winds have been strong over North America and the North Atlantic, keeping cold air bottled up to the north over Canada and the Arctic. This pattern is predicted to persist for at least another week.

Jeff Masters

While much of the U.S. has had a mild winter this year, record cold and snow are being blamed for more than a hundred deaths in Europe. According to the Associated Press, snow has fallen as far south as the Adriatic Sea, and the Black Sea has frozen along the Romanian coast. In Ukraine, temperatures dipped to the -20s°F, killing more than 40 people, many of them homeless, and hospitalizing hundreds more with hypothermia. Here, a woman braves a blizzard in Skopje, the capital of Macedonia.

Credit: EPA

Snow over Algeria in 2005. Winter weather descended on Northern Africa on January 26 and 27, 2005, leaving parts of Algeria and Morroco white with snow. Courtesy: NASA.

Date / time: 07/02/2012 13:24:24 [UTC]
Event: Snow Storm
Area: Africa
Country: Algeria
State/County: Statewide
Location: [48 departments]
Number of Dead: 25 person(s)

Description:

A cold snap sweeping large parts of Europe has also exacted a heavy toll in Algeria, where 25 people have died in accidents linked to heavy snowstorms, the fire and rescue services announced Tuesday. Twenty-eight of Algeria's 48 departments have had snow over the past week, including the capital Algiers. The snow has cut off access to many parts of the mountainous Kabylie region in the north, where a number of villages have been without power and water since the weekend. The rescue service said 10 people had died in traffic accidents linked to the bad weather and 15 had died of carbon monoxide poisoning caused by faulty gas heaters. Unused to snow, the authorities have struggled to cope. Colonel Mohamed Khelaf, director of the rescue effort, told Chaine III national radio that 40,000 troops had been deployed to clear roads, help the sick and bring supplies, including gas bottles, to remote areas. Further heavy snowfall was expected in the east and the centre of the country Tuesday and Wednesday.

Event updates:
Situation Update No. 1 on 07.02.2012 at 13:26:09.

By Amantha Perera

KAPARATOTTA, Sri Lanka (AlertNet) – When they headed out into shallow waters that evening, the fishermen of the small village of Kaparatotta didn’t notice anything to cause alarm. The sky was a little cloudy, and the sea its usual boisterous self – not safe for a swim, yet nothing seasoned fishermen couldn’t handle.

But around 9 pm on Nov. 25, 2011, the ocean suddenly turned vicious. Within a few minutes, the small wooden boats with outboard engines, trolling just 1 to2 kilometers from shore, were being battered by waves as high as 25 feet.

Despite years having passed since the 2004 Asian tsunami that wracked Sri Lanka’s coast, and a government mandate to improve early warning systems in the country, the fishermen had no warning of the approaching storm.

“I have never seen anything like that, ever in my life,” said fisherman Thushara Jayaweera. “Those kind of waves don’t break mid-sea usually, but we were being tossed up like rag dolls.”

The several crew members on his boat tried to sail towards the shore, but the waves were too high and rough for them to make progress. Thinking they had met their fate, they turned back towards deeper waters – a decision that saved their lives.

Closer to the shore, Lamahevage Chandana tried to manoeuvre his small vessel through a huge wave.

“The moment we got over (it), the boat was flipped up and dropped down. It split in two like a matchstick,” he recalled.

He grabbed hold of an old buoy tied to one of the masts. He and his father-in-law survived in the swelling sea for over seven hours by hanging on to the buoy.

“We could see the shore all the time, but the sea was so rough no one could get to us. We prayed and waited,” he said.

Those on shore watched helplessly as their relatives and friends were thrown around at the mercy of the rough ocean. Sometimes when the wind died down, they could hear faint cries for help.

“You can’t describe it in words – it was a tragedy. Families were standing where we are today and watching their loved ones struggle,” said Thakshila Damayanthi, a young woman who is also an elected member of the local urban council.

By the next day, 14 fishermen were dead; 11 of their bodies were never recovered. Along Sri Lanka’s southern coast, a total of 29 people died and over 10,000 buildings were damaged by the winds, which weather specialists attributed to a sudden temperature rise.

Experts say a mass of hot air rose quickly north of Kaparatotta, causing cold air from the south to gust northwest – a weather phenomena that seems to have become more common in recent years.

WAKE-UP CALL

Fishing communities are increasingly convinced that disasters like this could be prevented with simple warning techniques, such as text message alerts.

“There has been so much talk about early warning since the tsunami, but when it is really needed, we get nothing,” Damayanthi said.

The tsunami was a wakeup call on the need for the introduction of early warning mechanisms in Sri Lanka, according to Mudalihamige Rathnayake, head of the geography department at Ruhunu University, close to Kaparatotta.

“Before that, there was no concept of early warning or disaster mitigation,” he said.

Several months after the tsunami, in May 2005, Sri Lanka passed the Disaster Management Act, which established the Disaster Management Centre (DMC), the first national body set up to oversee disaster mitigation and relief efforts. One of the center’s mandates was to monitor and issue early warnings.

Rathnayake told AlertNet that, in the past few years, Sri Lanka has experienced increasingly extreme weather, which appear to be linked with climate change and which is making early warning much more important.

“We have seen the trend of an increase in disastrous weather events,” he said.

Since June 2009, the South Asian island nation has dealt with four large floods, affecting over 2 million people. Early last year, eastern regions received a year’s worth of rain in just one month, heavily damaging the vital rice crop.

Instances of very strong winds have also increased due to sharp temperature increases, which cause hot air to rise, pulling in colder air that brings gusts over a concentrated area, according to Rathnayake.

UN HIGHLIGHTS WEAKNESSES

Yet, despite the growing need to be prepared for disasters, a U.N. assessment – ironically released the same week as the Kaparatotta disaster – found that Sri Lanka’s warning systems still need much improvement.

The report highlighted a lack of coordination between the various government organisations tasked with monitoring and providing information to the country’s Disaster Management Centre.

“It is critical to the efficiency of the process that scenario development, early warning and related actions should not be considered in isolation but as an integrated process,” it said.

At least one government body – the National Aquatic Research and Resource Development Agency (NARA), which operates under the fisheries ministry – had knowledge of the sudden build-up of winds last November. Fisheries and Aquatic Resources Minister Rajitha Senaratne told parliament in the weeks after the storm that NARA had sent a warning to both the DMC and the meteorological department.

But DMC spokesperson Pradeep Kodipplili told AlertNet the centre “never got any official warning of any sort”.

NO BACK-UP BATTERY

Lack of preparedness was also evident on the ground. Damayanthi found that the local radio transmission station did not have a working back-up battery for its communications equipment when the power supply was disrupted by the high winds in Kaparatotta.

“You and I talk of early warning, but these guys had forgotten to charge the battery – that was what we were faced with that day,” she said.

The blame for not alerting the DMC has largely fallen on the meteorological department. But the U.N. assessment revealed the meteorological department also lacks the tools to accurately track developing weather patterns like the November storm.

“The Department of Meteorology of Sri Lanka does not have the capacity required to provide quantitative rain forecasts. Models currently used are assessed by the department as not fully reliable, and the information issued by the department is not detailed,” said the report. The department’s radar equipment is now being upgraded.

Ruhunu University’s Rathnayake also noted that the general public has not been educated about how to respond to warnings.

“We need to build awareness on how to react to cyclones, floods or even droughts. Different disasters require different approaches,” he said.

Rathnayake’s research in the south has found that the tsunami’s vast devastation has created a basic level of home-grown savvy.

“People know that if a tsunami is coming you need to run away from the shore. But beyond that they know very little,” he said.

At least some of the damage caused by floods in recent years could have been avoided if proper warnings had been issued, he added.

On the shores of Kaparatotta, there is little optimism this will start happening any time soon.

“The tsunami was the signal for us to take natural disasters seriously, but we haven’t,” said council member Damayanthi. “I don’t think a small tragedy like (ours) will change anything.”

To see a video version of this story, please click here.

Amantha Perera is a freelance writer based in Sri Lanka. This story is part of a series supported by the Climate and Development Knowledge Network.

Some rain is gracing the Golden State today, which is experiencing abnormally dry to moderate drought conditions.

With storms a rarity this winter, a system paralleling the coast is bringing a rainy day to coastal and some inland areas of California.

A few tenths of an inch of rain are in store for most of northern and central California with amounts dwindling farther south. However, a soaking will reach as far south as San Diego and into Baja California, Mexico, as the day progresses.

A bit of rain will fall over the San Joaquin Valley into the evening.

Most desert areas will barely have enough to dampen the ground, but there can be a few exceptions.

As with most rain in California, and especially since it is so infrequent this year, motorists should allow extra stopping distance and use caution when cornering at intersections. Enough rain will fall to cause isolated incidents of urban flooding.

Since the storm is moving southeastward, rather than pushing substantially inland, the Sierra Nevada will more or less constitute the eastward extent of the precipitation with up to a few inches of snow over some of the southwest facing ridges. There may be enough snow to make for slushy spots over Donner Pass.

The rain will end from northwest to southeast across California during the afternoon and evening hours. The rain should taper to spotty showers during the evening rush around San Francisco and Sacramento but will continue through the evening rush in Los Angeles and San Diego.

The storm will grow stronger and will unload more substantial rain and mountain snow over central Mexico during the end of the week.

Men shoveling snow from a street in Sarajevo. Record snowfall has paralyzed transportation in the Bosnian capital, where a state of emergency has now been declared. Photo by Sulejman Omerbasic, copyright © Demotix (5/02/12).

Serbia’s national television network, RTS, and other media reported on Friday that a state of emergency has been declared by the government, while citizens have been reporting critical situations throughout the country and that municipal services have been doing a poor job of tackling the snowfall in many urban areas.

In an article titled “Serbia Blocked by Snow, State of Emergency in 27 Municipalities, Recommendation to Call Off School Attendance” [sr], the Head of the State of Emergency Sector of the Serbian Ministry of Internal Affairs, Predrag Maric, is reported to have stated on Friday:

27 municipalities in Serbia have declared a state of emergency due to heavy snowfall. Maric has told Beta news agency that the most difficult situations are in Sjenica, Ivanjica, Prijepolje, Crna Trava and Surdulica, where the height of snow has reached approximately 2 meters. According to him, power supply is “relatively good,” outages are being fixed quickly and there have been no long power outages.

Maric also announced the possibility of declaring a full state of emergency nationwide, which the Government did on Sunday evening, cancelling school throughout Serbia at least until Friday, February 10, among other things.

Several actions have been organized by the online community in Serbia and the region to fend off the snow and to attempt to regain a functional state in urban areas at least, such as a #lopataup (”#shovelup”), organized by one online community leader, Zoran Torbica, and other local Twitter users.

In the meantime, Al Jazeera Balkans, the recently established regional office of Al Jazeera news network in the region, has joined forces with the team from Ushahidi to set up a platform for tracking verified information on everything from road blocks, power outages to other critical points and information in the entire region. Ushahidi is an open-source platform for information collection, visualization and interactive mapping, which was also used in Serbia just after the earthquake in Kraljevo in November 2010 to map and track damage in the area.

Haris Alisic, who heads the New Media team for Al Jazeera Balkans, launched the platform on Sunday evening, and many members of the online community, including some of the region’s GV authors, have joined the Al Jazeera-Ushahidi team in curating, tracking and verifying reports from the region.

The adapted Ushahidi platform can be located on Al Jazeera’s official site, while reports can be sent in by anyone using the following channels:

- via SMS to +387644218661
- via Twitter by using the hashtags #kolaps #sneg #snijeg #lopataup #iskljucenje
- via email to oluja2012@aljazeera.net
- or by entering information directly into the form on the”pošaljite izvještaj” tab on the Al Jazeera page

If you would like to volunteer your time to help map critical areas and are familiar with using online tools, please contact the author of this article, or Haris Alisic via Twitter, or leave a comment here on Global Voices, and we will contact you for more information on what you can do to help. We also ask that you all begin reporting from your area on Twitter and using the above-mentioned hashtags on Twitter, which are automatically collected by the platform and then reviewed and verified by Al Jazeera and volunteers.

Bosnian men are trying to push a car away from the deep snow. Photo by Sulejman Omerbasic, copyright © Demotix (5/02/12).

Written by Danica Radisic

Wait, you thought we were going to talk about Sunday night’s football game? That small clash between the New York Giants and the New England Patriots in Super Bowl 46, watched by more than 100 million fans in the U.S.?

Well, we are. Sort of. Because Sunday’s Super Bowl in Indianapolis capped this snowless winter’s coming-out party. Thanks to the winter that wasn’t, Indy was a big hit. Temperatures in the city averaged approximately 25 degrees higher than normal this week. Mild, snowless winters like this one may be more common as the world continues to warm, as will extreme variations in weather patterns. Much of Europe has been enduring that kind of variation as severe cold and snow has killed hundreds across the continent the past few days.

When Indianapolis was awarded the Super Bowl several years ago, the groans from the football congnoscenti were audible. Indianapolis? A hick town in the Midwest? Do they have any other restaurants other than St. Elmo’s? And did anyone tell them the Super Bowl is in February?! The logo should have been a set of snowblowers.

Some of the whining came from the party crowd that would rather have every Super Bowl in Miami or New Orleans, but almost everyone prefers sunshine and beaches to ice scrapers and rock salt. The game wouldn’t be affected because the Colts had the good sense to build a dome over Lucas Oil Stadium, but the city’s week-long party leading up to it is always colored by the weather.

But once the moaning stopped and people arrived in Indy this past week, they were treated to mild temperatures that were pushing 60 degrees. All the gloom and doom about ice and snow, about how it would snarl traffic and keep people from flocking downtown to celebrate the event? That happened last year, when the Super Bowl was in Dallas.

So the locals in Indy celebrated the unseasonably balmy weather by throwing a great party, with hundreds of thousands flocking downtown to see a city transformed by the NFL’s big show. There was even a temporary zip line over downtown that people slid down without gathering icicles. The national media gushed over the atmosphere.

Locals in Indy celebrated the unseasonably balmy weather by throwing a great party, with hundreds of thousands flocking downtown to see a city transformed by the NFL’s big show. Credit: Carl Van Rooy/flickr.

“It’s at the top of the list. It’s one of the best Super Bowls I have ever covered,” said Rick Gosselin, a columnist for the Dallas Morning News. “Indianapolis got a break because of the weather. This has not been a cold winter. I have always thought this is a great big event town.”

This year, the first dip in the weather came the day before the big game, when it rained.

Colts owner Jim Irsay joked that it was all part of the plan. “I know the way we’re preparing and the way we’ve controlled the weather, which is hard to do. But we’ve had certain techniques that we’re going to keep hidden,” he said.

And what’s the next cold-weather, turned warm-weather venue seeking Super Bowl stardom? Two years from now when it comes to the greater New York area. It gets a big opportunity to show off then because not only is some of the fun outdoors, but so is the game.

Oh yeah. One more thing. The final score was New York 21, New England 17.

Additional Online Resources:

Super Bowl Revelers Flock Downtown — The Indy Channel

Reaction: What Super Bowl 2012 journalists are saying about Indy — IndyStar.com

Super Bowl week begins in Indianapolis; ice and snow no-shows — Pittsburgh Tribune-Review

Storm Chaser Andy Gabrielson Killed in Accident

Feb 6, 2012; 9:27 AM ET

Storm Chaser Andy Gabrielson, who had an uncanny ability to film dozens of tornadoes up close, perished Saturday evening in a tragic traffic accident in Oklahoma. He, and another driver, were the victims of a drunk driver going the wrong way on the Interstate. This is the second storm chaser death this decade, but it’s notable that neither died while chasing.

Andy was a well respected chaser who had traveled over 180,000 miles in 24 states to intercept over 150 tornadoes — arguably the most successful, even more so than well-known chaser celebrities. Yet he shied away from the limelight, doing what he did to document for science and save lives through spotter reporting. An incredible thing happened upon the news of his death — dozens of chasers and spotters in Kansas formed the initials “A.G.” by faking their GPS positions on the SpotterNetwork.Org‘s map, while those who couldn’t lit up the rest of the Midwest like a Christmas tree. It was a fitting tribute to a great man. Here’s a timelapse of the GPS positions:

A memorial fund has also been setup by his chasing group, SevereStudios.com. They say: “100% of donations will be given to the Gabrielson family to help his young daughter. Andy’s parents are also researching a scholarship in Andy’s name to help students interested in weather. In addition to the Memorial Fund, you may still purchase Andy’s DVD’s at the SevereStore with all proceeds after shipping going to the Gabrielson family.” If you want to see what the legend was like (and help his family), buy those two DVDs today.

He was chasing in Texas as recently as Friday, when WFAA interviewed him during a ridealong (video above). You can also leave comments on SevereStudio’s page; a couple are reprinted below:

“Andy was one of the first chasers I started watching, and I remember watching every time I could, I met him a few times and was astounded by how polite he was.”

“I always admired the work that Andy did, he put his heart and soul into chasing and documenting severe weather. Simply one of the best of the best. Wishing I had a chance to shake his hand. He will be watching over us now. Andy, steer those tornadoes to open fields and live streams. Rest in peace, dear Sir.”

Another nice way that we can remember his work is to nominate him for a ShortyAward in #weather. This was his last video uploaded to YouTube, less than a month ago (although he was streaming live video while chasing in Oklahoma as recently as last Friday):

Figure 1. Radar-estimated rainfall from Invest 90L.

What’s going on?
Obviously, strong tropical disturbances capable of developing into named storms are very rare in February, and I’ve never seen one in my 30 years as a meteorologist. However, ocean temperatures are warm enough year-round to support a tropical storm in the waters of the Western Caribbean. Water temperatures today in the region were 26 – 26.5°C (79 – 80°F), which is near average for this time of year. If an unusual configuration of the jet stream allows wind shear to drop below about 25 knots in the Western Caribbean, there is the opportunity for a rare off-season tropical storm to form in February. I discussed in an appearance on NPR’s All Things Considered on Friday just how unusual the atmospheric flow patterns have been this winter, and today’s rare tropical disturbance over South Florida is symptomatic of how whacked-out our 2012 atmosphere has been. In isolation, the strange winter weather of 2011 – 2012 could be a natural rare occurrence, but there have been way too many strange atmospheric events in the past two years for them all to be simply an unusually long run of natural extremes. Something is definitely up with the weather, and it is clear to me that over the past two years, the climate has shifted to a new state capable of delivering rare and unprecedented weather events. Human emissions of heat-trapping gases like carbon dioxide are the most likely cause of such a shift in the climate, as I discussed in my post last week, Where is the climate headed?

A historical precedent: the 1952 Groundhog’s Day tropical storm
There is a historical precedent for a tropical storm this time of year–the 1952 Groundhog’s Day tropical storm that hit Southwest Florida. According to Wikipedia,

The 1952 Groundhog Day Storm was the only Atlantic tropical cyclone on record in the month of February. First observed in the western Caribbean Sea on February 2, it moved rapidly throughout its duration and struck southwestern Florida within 24 hours of forming. In the state, the winds damaged some crops and power lines, but no serious damage was reported.

Meteorologist Andrew Hagen performed a re-analysis of all the tropical storms between 1944 – 1953 for his Ph.D. thesis, and looked in detail at the 1952 Groundhog Day’s storm. He noted that it didn’t look like a classic tropical storm, but it didn’t look like an extratropical storm, either, and should stay in the database as the first named storm of 1952. In the old teletype files for February 1952, he found a February 2 message from the Cuban Weather Service that expressed some concern about possible tropical development between Cuba and Florida. NHC responded: “TROPICAL STORMS DO NOT FORM IN FEBRUARY.”

Figure 2. February 2, 1952 teletype message from the Hurricane Center to the Cuban Weather Service, explaining that there couldn’t possibly be a tropical storm in February. Image credit: Andrew Hagen.

Jeff Masters

Photo from Alaska Volcano Observatory.

By John Marsh, AccuWeather.com Staff Writer

Feb 6, 2012; 6:50 PM ET

Image: Gift of the Givers (Click on image for larger view.)

Accompanied by the Ehlanzeni district Executive Mayor, L. M. Shongwe, Executive Mayor Ms T.S. Khoza, members of SAPS Nkomazi Municipality, Ehlanzeni District and provincial government members, GOTG responds to the flood victims in Mpumalanga. The 50 families in Buffelspruit directly affected by the flood as well as the Mekemeke villagers received:

350 Food Parcels
50 10kg Mealie Meal
50 Washing Powder
50 Hair Relaxer
10 Boxes of Baby Milk
100 Packs Huggies
30 Cases Juice
1 Pallet Margarine
200 Blankets

Total Project Value: R350 000.00

- Gift of the Givers.

Indications are a storm will plow into Mexico later this week to spread rain over a large part of the nation during an unusual time of the year.

Essentially, this storm would bring from one to three winter season’s worth of rainfall and mountain snow.

Typically the period from late fall to the early spring is a dry time of the year for the region. Much of Mexico receives the bulk of its yearly rainfall from warm season-driven showers and thunderstorms spanning late May into early October.

A storm riding in from the central Pacific Ocean will plow southward later this week and may set up shop for a several-day period over central and southern Mexico.

From this position, the storm should be able to pump beneficial moisture over the a significant part of the nation from the last part of this week into the weekend.

While the details as to which areas will benefit the most from the wet pattern are unclear, there is potential for several tenths to an inch of rain in many locations. Several inches of rain could fall in portions of central and northeastern Mexico.

Rainfall for the entire month of February tends to be on the order of one to several tenths of an inch with less than an inch of rain falling on average for the entire winter season.

Portions of Mexico have been in a multi-year drought with rainfall even lacking during the wet season.

It is possible Mexico City (at an elevation of 7,300 feet) may receive snow from the storm. There is a more remote possibility that snow will fall in Guadalajara (at an elevation of 5,000 feet).

A few feet of snow could fall over the highest elevations of the Sierra Madre.

While the storm will be mostly beneficial, there is a slight risk of too much rain in a few places. This would generally only occur if the storm’s heavy rain is focused over the same area for a few days, or if a complex of thunderstorms were to develop, unloading a few inches of rain in a matter of hours.

The system due to move into Mexico later this week is not associated with the system brushing South Florida and the Bahamas today. However, it is part of the same system that will bring beneficial rain to much of California over the next couple of days.

It could be sign that the southern branch of the jet stream is ready to play a more active role with storms in the U.S. during the latter part of the winter.

The jet may add subtropical moisture to the storms farther north, perhaps giving them a boost in intensity and precipitation output.

The latest in a series of major winter storms will dump heavy snow in areas from the Balkan Peninsula and Italy to North Africa early in the week.

By Jim Andrews, Senior Meteorologist

Feb 6, 2012; 11:30 AM ET

Some of these same areas have already received deep, even immobilizing, accumulations of snow following last week’s series of storms, which disrupted transportation infrastructure over a wide area.

Snow has contributed to the weather-related death toll, since late January, of at least 300 people, most of them dying of cold exposure.

About 70,000 people in Serbia were still cut off in snow-bound villages, according to many recent reports. Some mountain areas in Algeria also remained isolated.

Further disruptions to transportation by road, rail and air will take place.

Through Tuesday, heaviest new falls of snow will hit eastern and southern Italy to the mountains and inland valleys of Bulgaria, Serbia, Bosnia-Hercegovina, Macedonia, Kosovo and Montenegro.

By Wednesday, a fresh foot of snow will cover some of these regions.

Hills above the coast in eastern Algeria and nearby Tunisia will also get new falls of snow.

Although the Mediterranean storm will weaken markedly Wednesday and Thursday, a new storm could form over the northwestern Mediterranean Sea late in the week, leading to even more falls of disruptive snow.

St George, Queensland, has seen thousands of residents evacuated as record-high flood waters invade their town, the Australian ABC said on Monday.

The flooding Balonne River was one of many that have burst banks and spilled into towns on plains of inland Queensland and nearby New South Wales.

A record-high flood crest of 14.0 meters was forecast for the Balonne in St George during Monday night, local time.

About 30 homes outside of flood protection were already flooded as of Monday.

Emergency workers had earlier raised a temporary flood barrier at the 14.5-meter level.

Earlier, fears had been that the river would peak near 15.0 meters, resulting in a widespread inundation of the town.

Meanwhile, the town of Mitchell was beginning to assess what the Queensland Premier called a “terrible mess” left by the flooding, the ABC said.

More than 70 percent of the homes in Mitchell, a town of 950, were flooded, some to their roof.

In northern New South Wales, the rampaging Namoi left more than 2,000 people isolated ahead of its expected crest at Wee Waa.

Further record crests are forecasts in the area as runoff in the Darling River basin flows southward and westward during the coming days and weeks.

Exceptionally heavy rain bolstered by tropical moisture since late January sparked the record flooding.

Video credit: YouTube/DownUnderDoug

Kangaroo in flooded waters. Image extracted from YouTube video.

While the clock is ticking on the development of a tropical system near the Florida Straits, the feature is unloading drenching rain on the Keys and South Florida.

Key West has received over 4.50 inches of rain since the midday hours Sunday, enough to cause minor urban and poor drainage area flooding.

Rain was spreading northward over the Florida Peninsula and was reaching into some of the central counties during the midday today.

While drought conditions are not as severe as that of part of Georgia, South Carolina and the Florida Panhandle, central and South Florida is in need of rainfall, on the order of a few inches.

This was the drought status as of Jan. 31, 2012, from the National Weather Service and the United States Department of Agriculture. Yellow areas indicate regions which are abnormally dry, while red areas indicate regions of extreme drought.

Most of the rain from the pattern the next couple of days will fall over South Florida, the Bahamas and part of Cuba. Several additional inches of rain are possible for a few locations.

Tropical storm Jasmine is forecast to strike Vanuatu as a tropical cyclone at about 08:00 GMT on 8 February.Data supplied by theUS Navy and Air Force Joint Typhoon Warning Center suggest that the point of landfallwill benear19.7 S,168.5 E.Jasmine is expected to bring 1-minute maximum sustained winds to the region of around120 km/h (74 mph).Wind gusts in the area maybeconsiderably higher.

According to the Saffir-Simpson damage scale the potential property damage and flooding from a storm ofJasmine’sstrength (category 1)at landfall includes:

• Storm surge generally 1.2-1.5 metres (4-5 feet) above normal.
• No real damage to building structures.
• Damage primarily to unanchored mobile homes, shrubbery, and trees.
• Some damage to poorly constructed signs.
• Some coastal road flooding and minor pier damage.

There is also the potential for flooding further inland due to heavy rain.
The information above is provided for guidance only and should not be used to make life or death decisions or decisions relating to property. Anyone in the region who is concerned for their personal safety or property should contact their official national weather agency or warning centre for advice.

This alert is provided by TropicalStorm Risk (TSR) which is sponsored by Benfield, Royal & SunAlliance,Crawford & Company and University College London (UCL). TSR acknowledges thesupport of the UK Met Office.

Figure 1. Is this football season or baseball season? The Super Sunday Invest 90L looks more characteristic of something we’d expect to see in May.

Forecast for 90L
Both the GFS and ECMWF models predict that the shear will remain below 25 knots through Monday, so there is some potential for continued development of 90L as it moves northeast towards South Florida. On Monday afternoon or evening, the storm will merge with a cold front and move over South Florida, bringing heavy rains of 1 – 3 inches and sustained winds of 20 – 25 mph. If it develops into a tropical depression or tropical storm, which I put at a 20% chance, the winds and rains will be higher. I doubt 90L has enough time or favorable enough conditions to become a tropical or subtropical depression, especially considering the disturbance’s small size. There is a historical precedent for a tropical storm this time of year in this location–the 1952 Groundhog’s Day tropical storm that hit Southwest Florida. According to Wikipedia,

The 1952 Groundhog Day Storm was the only Atlantic tropical cyclone on record in the month of February. First observed in the western Caribbean Sea on February 2, it moved rapidly throughout its duration and struck southwestern Florida within 24 hours of forming. In the state, the winds damaged some crops and power lines, but no serious damage was reported.

Jeff Masters

Satellite Photo of Invest 90L

It has been an odd winter for much of the nation. Snow has been hard to come by in many places while others have had several feet in just the last few days. Warm temps, plentiful rain fall and even a quick start to the severe weather season have all been the norm this year for much of the southern part of the country. We can now add “tropical interest” to the mix.

The NHC is monitoring an area of showers and thunderstorms over the northern Caribbean Sea and southern Gulf of Mexico. There is definitely a surface trough of low pressure across the region which is helping to focus the abundant energy found in the warm waters of the Caribbean and Gulf. In fact, water temps are easily above

SST Map (click to enlarge)

the 80F threshold that we look for in tropical development. However, it is February and upper level winds, among other factors, are simply not going to allow 90L to do much more than create a buzz within the hurricane blogosphere. Its presence could lead to some scattered rain showers for the Florida Keys and perhaps mainland south Florida over the next day or two but that’s about it.

Has a tropical storm ever formed in February that affected the U.S.? Yes. In 1952 there was such an event. Check out the historical track map from Stormpulse: http://www.stormpulse.com/tropical-storm-one-1952

Peloponnese, Greece. Google maps.

Date / time: 05/02/2012 13:30:38 [UTC]
Event: Flood
Area: Europe
Country: Greece
State/County: Multiple areas
Location: [Western regions]
Number of Dead: 1 person
Number of Evacuated: 200 persons
Damage level: Heavy

Description:

One person was killed and more than 200 people evacuated as torrential rain caused widespread flooding and mudslides in the western Peloponnese, in Greece, radio reports said Sunday. Police discovered the body of an 80-year-old woman in her inundated home in the town of Livadia, located in the prefecture of Ilia. Thunderstorms have lashed parts of western Greece since Saturday evening, flooding hundreds of homes and shops. Rescue crews used helicopters to evacuate residents.

The band of snow has now moved on to the near continent and has left a legacy of grey skies across central and eastern areas of England, but brighter skies across Wales and SW England should spread in across The Midlands this afternoon. SE England and East Anglia will likely remain dull, cold but dry this afternoon – with a maximum temperature of just 3C in London. It will be milder in the west today and after a bright morning we will see cloud thicken across the far SW of England, west Wales and NW England, bringing some drizzle or light rain by late afternoon. A grey day for Northern Ireland and western Scotland, with some drizzle or light rain, with sleet and snow over high ground. Eastern Scotland probably escaping with a mainly dry day with some bright or sunny spells, temperature reaching 6C in Edinburgh.

Overnight, mist and low cloud will become quite extensive across many areas, with freezing fog forming over the snow fields of central and eastern England. And to add into the mix there will be some patchy drizzle or light rain around, which combined with temperatures falling close to or below freezing over compacted snow, will lead to a risk of icy surfaces on Monday morning. Monday itself is likely to be a gloomy day for much of the UK, with fog patches slow to clear across central and eastern areas and some drizzle or light rain likely to affect the far west and eastern England at times. It will be less cold, with temperatures reaching 4-5C in the east, 7-9C in the west.

For the rest of the week, Tuesday may see some rain in the far west, which will fall as sleet and snow over the mountains, colder and drier air returning across eastern England from the east, so turning clearer and sunnier here. Wednesday to Friday it looks like being largely dry, sunny and cold by day across southern, central and eastern areas, with hard overnight frosts returning. The northwest and far west will be milder, windier and cloudier with rain at times.

Issued: Sun 05/02 12:04

Credit: Marco Anderson

As forecast, an Atlantic weather front pushed across the UK through yesterday and overnight bringing snowfall to many parts of the UK. As expected the worst of the conditions were across the east of the UK, where the cold air from the continent was able to hold on, leading to significant snowfall, especially across South East England, East Anglia, Lincolnshire, parts of the Midlands, Yorkshire, the North East and the southern uplands of Scotland.

Further west, although there was some snow for a time, the milder air, associated with the weather front soon turned the snow to rain, leaving a grey rather than a white start to Sunday.

As the snow and rain moved away, skies cleared allowing it to turn cold again with widespread ice in many conditions. The Met Office still have an Amber warning for icy roads in force at the moment valid until midday today. Overnight lows got to -9.8C at Bramham, -8.9C at Church Fenton, -8.4C at Topcliffe, Dishforth and Leeming, -7.3C at Church Fenton. -7.2C at Linton-on-Ouse and -6.2C at Ravensworth.

The table below shows snow depths recorded at 9 am this morning.

The band of snow has now cleared the far southeast of England and for the rest of the day it will remain largely dry, but cold in the east, Further west it will turn cloudier with some outbreaks of rain, with some sleet or snow on higher ground. Overnight, cloud and a little rain will slowly spread to many places, although eastern Scotland will probably remain dry. Cold and foggy, especially in areas with lying snow and frosty in the east.

Heading into next week there is only a little snow in the forecast at the moment. Monday will be rather cold with ice likely to be a hazard especially in the southeast. It will then be generally cloudy with only occasional brighter intervals. Patchy rain will affect many areas, this mainly light. It will stay very cold in the east and southeast, but will be less cold elsewhere.

Lala, an 11-month-old Dachshund mix, enjoys snow in Sarajevo, Bosnia and Herzegovina. Photo submitted by AccuWeather.com Facebook fan Mirna L. on Saturday, Feb. 4, 2012.

By Kristina Pydynowski, Senior Meteorologist

Feb 5, 2012; 9:57 AM ET