World weather roundup

21 01 2016

In this blog we take a look at what’s happening around the world where the weather is straying away from what’s normal or has the potential to bring disruption.

North America
A deep area of low pressure will bring the threat of severe weather across the Gulf States of Louisiana, Mississippi, Alabama and Georgia with heavy rain and severe thunderstorms combined with gale force winds. This rain may lead to more flooding in the lower Mississippi River basin.

Further north and east this system a ‘nor’easter’ will bring a risk of disruptive snow combined with gale force winds. Areas from Washington and Philadelphia up to New York are most at risk, and the US National Weather Service have issued blizzard watches for the risk of 8-12 inches of snow. There is also a risk of coastal flooding with the strong winds leading to rough seas too. Impacts on travel in the area could be significant.

Asia
Across eastern and southeast Asia a large surge of cold air will spread across China and Taiwan with further heavy falls of snow anticipated across Japan. Parts of China and Taiwan will experience temperatures some 15 degrees below the average for January, with Taipei seeing highs of 6C instead of the low 20s Celsius. Some snow is also likely here over fairly modest hills.

Further south the unseasonal weather will bring a spell of heavy rain across northern Thailand, Laos and Vietnam, bringing a risk of flooding.

Australasia
In the South Pacific Ocean, Tropical Storm Victor lies to the east of Tonga and is expected to pass just to the south of the islands on Friday, bringing a period of gale force winds, heavy rain and thunderstorms and a risk of coastal flooding. The weakening storm is then expected to head towards New Zealand over the weekend.

Official warnings for the latest tropical cyclones in the South Pacific are produced by the Fiji Meteorological Service. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance. We also provide updates on current tropical storms via @metofficestorms on Twitter.

Europe
A large blocking area of high pressure over central and southeastern parts of Europe, which until recently also brought cold weather to the UK, will persist across these areas into the weekend.

Forecast pressure chart for midday Saturday 23 January 2016

Forecast pressure chart for midday Saturday 23 January 2016

Across Scandinavia, the Baltic States, Poland and Western Russia very cold conditions will be maintained with temperatures around 5-10C below average, but with dry weather expected.

Much of southeast Europe will also continue to feel the effects of this cold air with temperatures across inland areas well below average by day and some areas struggling to rise above freezing. Overnight minimums widely in negative double figures will compound the cold. Snowfall is also likely to lead to some disruption over Romania and then parts of Turkey, Serbia and Croatia over the coming days as weather fronts affect these areas. Next week should see a return to conditions more typical for the time of year as milder air arrives from the south and west.

Further north, the cold, still conditions are the perfect recipe for fog and freezing fog with parts of France, Belgium, the Netherlands and Germany being affected by this during Thursday and Friday before milder air arrives over the weekend.





Cyclone Quartet in the Tropics

13 03 2015

There are currently four cyclones active across tropical regions of the Pacific and Indian Oceans. Here we take a look at each storm and its impacts.

Four cyclones seen on 12 March 2015. Image courtesy of The National Institute of Informatics

Four cyclones seen on 12 March 2015.
Image courtesy of The National Institute of Informatics

Cyclone Pam is the most intense of the four cyclones and, at the time of writing on March 13, is making landfall over the Republic of Vanuatu in the South Pacific Ocean as one of the most intense southern hemisphere cyclones on record. Sustained winds are estimated to be near 170 mph with a central pressure of 900 mb. Port Vila, the capital of Vanuatu, is located on the island of Efate and here preparations for the cyclone have been rushed to completion and residents of the city with a population of 45,000 have taken cover as the cyclone approaches. The eye of the cyclone is expected to pass just to the east, if not directly over the city.

Cyclone Pam seen on 13 March 2015 Image courtesy of The US Naval Research Laboratory

Cyclone Pam seen on 13 March 2015
Image courtesy of The US Naval Research Laboratory

Australia was struck by two cyclones simultaneously in February (Marcia and Lam) and this week is dealing with another dual threat. Cyclone Olwyn came ashore yesterday (12 March) in Western Australia near the town of Exmouth with wind gusts of 112 mph recorded at Learmonth Airport and a 1.75 m storm surge. Olwyn is tracking parallel to the coast and so is continuing to bring strong winds and heavy rain to a large stretch of the coast of Western Australia.

Meanwhile in northern Queensland Tropical Storm Nathan has made a very close approach to the coast bringing over 200mm rain in places in 24 hours. However, the centre of the storm has stayed off shore and is predicted to move back out to sea so minimising the threat of this storm to populated areas.

Tropical cyclones in the northern hemisphere are not frequent at this time of year, but in the North Pacific Tropical Storm Bavi has formed and is slowly gathering strength. The storm is well away from any large land masses, but by the end of the weekend could pass close to the US island territory of Guam.

Official warnings for these cyclones are produced by the Fiji Meteorological Service, the Australian Bureau of Meteorology and the Japan Meteorological Agency. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance. We also provide updates on current tropical storms via @metofficestorms on Twitter.

 





Cyclone Evan strikes Samoa

13 12 2012

Towards the end of every year tropical storm activity moves from the northern hemisphere to the southern hemisphere. The South Indian Ocean has already spawned three tropical storms including the unusually strong early season Cyclone Anais in October. Attention has now switched to the South Pacific Ocean and Cyclone Evan.

Evan formed near Fiji a few days ago and moved north-east as it strengthened. As it reached the equivalent of hurricane intensity (winds near 75 mph) it made landfall over Samoa close to the capital city of Apia. Although winds of this strength are not exceptional for a cyclone, first reports indicate considerable wind damage and flooding from a storm surge of 12-15 feet (3.5-4.5 m). This storm surge is of similar height to that experienced in New York City during ‘Superstorm’ Sandy in October.

Visible satellite image of Cyclone Evan on 12 December 2012

Visible satellite image of Cyclone Evan on 12 December 2012

Although Samoa lies within the cyclone belt of the South Pacific Ocean, the island nation has been relatively storm free for many years. Cyclone Heta passed close by in 2003, but the last time Samoa received direct strikes from tropical storms was in 1997 and 1998 by storms named Tui and, coincidentally, Evan.

To make matters worse, Cyclone Evan is expected to become slow moving near Samoa and American Samoa, producing large amounts of rainfall, before turning back south-west. Latest forecasts suggest Evan will strengthen some more and could threaten a strike on Fiji early next week.

Regional warnings for Cyclone Evan are produced by the Fiji Meteorological Service. The Met Office routinely supplies predictions of cyclone tracks from its global forecast model to regional meteorological centres worldwide, which are used along with guidance from other models in the production of forecasts and guidance.

You can keep up to date with tropical cyclones around the world on our website or follow us on Twitter.








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