Extreme weather in Europe up to the Arctic

'Zombie' Hurricane Leslie to finally unravel in Portugal, Spain this weekend

AccuWeather,

12 October, 2018

Leslie has held on like a zombie in the Atlantic since September, but the wandering in the ocean may come to an end well before Halloween.

Leslie has been meandering the Atlantic since it first formed on Sept. 23.

Through Friday, Oct. 12, Leslie has stayed between 30 and 65 degrees west longitude well away from any land or island areas and has survived on warm waters and moisture over the middle of the Atlantic.

The tropical cyclone has been bumped around by weather systems passing by over the North Atlantic but has not encountered a strong enough system to thrust the storm toward land.

Now, all of that may change as a non-tropical feature is forecast to pull Leslie eastward and allow the storm to break out of the central Atlantic region, where it has been trapped for weeks.

"The strong front moving through the United Kingdom could pull Leslie towards Europe by early next week," said AccuWeather Meteorologist Tyler Roys.

Seas and surf in this area will build ahead of Leslie's approach starting with the Azores, Canary Islands and the Island of Madeira.

Leslie is interacting with some wind shear, likely bringing the storm down to tropical storm criteria on Saturday as it pushes just north of the island of Madeira.

Despite the exact strength of Leslie, waves of heavy rain, as well as gusty winds will be likely across Madeira, even if there is not direct landfall.

Increasingly heavy rain and a uptick in wind gusts are expected to start as early as late Saturday in southern Portugal.

"Wind gusts of 65 to 80 km/h (40-50 mph) are possible across southern Portugal and southwestern Spain, especially near the coasts," added Roys.

Torrential rainfall will also accompany Leslie as it moves from the coast to inland locations of the Iberian Peninsula. Rainfall amounts of 25-50 mm (1-2 inches) are likely with an AccuWeather Local StormMax™ of 100 mm (4 inches).

The cities likely to be most affected will be Lisbon to Lagos and Faro, Portugal, and from Huelva and Seville, Spain, to the Strait of Gibraltar.

There is a remote chance that Leslie not only survives the hostile weather zone but could also drift back to the southward toward the Canary Islands and western Africa coast.

Should this be the case, rough seas would still likely affect southern Portugal and Spain, in addition to Morocco.

If Leslie makes this southerly turn and avoids land, it could make a run at the longest-lasting storm in the Atlantic Ocean.

In order for Leslie to be the longest-lived tropical cyclone on record, it would have to hold through the third week of October and into the fourth week of the month. Pacific Hurricane/Typhoon John holds the record for longevity with 31 days.

There is a chance that Leslie may rival the Atlantic tropical cyclone longevity record. That title is held by the San Ciriaco Hurricane in 1899. The 1899 storm killed thousands of people in Puerto Rico and lasted for nearly 28 days.

Leslie first formed over the middle of the Atlantic and about 1,145 miles (1,845 km) west-southwest of the Azores.

During the first few days of its life, Leslie was a subtropical storm. A subtropical storm has characteristics of a tropical storm and also a non-tropical storm.

During the late afternoon hours on Saturday, Sept. 29, Leslie had acquired full tropical characteristics.

Early on Wednesday, Oct. 3, Leslie became a hurricane. However, it would not be the last time for Leslie to do so.

By the late afternoon hours on Thursday, Oct. 4, Leslie had weakened to a tropical storm and would remain as a tropical storm into Tuesday, Oct. 9.

During the late evening hours on Oct. 9, Leslie again garnered enough strength to regain hurricane status.

Leslie is not the only system tracking through the Atlantic, the lingering circulation and moisture from Michael, which caused catastrophic damage in the Florida Gulf Coast, and Nadine will be traversing the Atlantic through the weekend.

There is the chance that Michael as a tropical rainstorm may hit part of the same area of Spain and Portugal after Leslie's arrival.

Major heat wave for northern Europe and the Arctic this weekend

Severe Weather EU,

11 October, 2018

Models agree: northern Europe and the Arctic are in for a major heat wave this weekend. Temperatures are expected to be up to 10-15 °C above the long term average for this period!

The strong ridge and warm air advection ahead of the low pressure area over the Atlantic (including the upcoming cyclone ‘Callum’) will result in temperatures well above the long-term average for this period. Temperatures are expected to soar 

10-15 °C above the 1981-2010 average across large parts of northern Europe, as 

well as over northern parts of central Europe. Additional warming is expected 

across fjords in western Norway as southeasterly winds produce significant Foehn effect / warming of the airmass.

Temperature anomaly (2 m temperature) across Europe from Friday to Monday. GFS model. Map: Wxcharts.eu

Additionally, the warm airmass will push far into the Arctic region, over eastern Greenland and Svalbard, pushing almost all the way to the North Pole.

Temperature anomaly (2 m temperature) over the northern hemisphere on Sunday. GFS model. Map: Wxcharts.eu

Polar jet circulation changes 

bring Sahara dust to Arctic, 

increasing temperatures, 

melting ice

Eureka Alert,

10 October, 2018

Fast Facts

• A new atmospheric mechanism by which dust travels from the Sahara Desert across the eastern side of the North Atlantic Ocean towards the Arctic has been discovered
• The dust emission was generated by a Saharan cyclone that was triggered by the intrusion of a trough emanating from the polar jet
• The poleward transport of warm dust was caused by a meandering polar jet stream
• Approximately half of the warming in the Arctic is being attributed to increased moisture and heat fluxes transported to the region from lower latitudes

A new atmospheric mechanism by which dust travels from the Sahara Desert across the eastern side of the North Atlantic Ocean towards the Arctic has been discovered

The dust emission was generated by a Saharan cyclone that was triggered by the intrusion of a trough emanating from the polar jet

The poleward transport of warm dust was caused by a meandering polar jet stream

Approximately half of the warming in the Arctic is being attributed to increased moisture and heat fluxes transported to the region from lower latitudes

Abu Dhabi, October 10, 2018: Research scientists at NYU Abu Dhabi, along with other global researchers, have identified a new mechanism by which warm dust travels from the Sahara Desert to the Arctic Circle, which has been proven to affect rising temperatures and ice melt in Greenland.

Their findings highlight the role that the polar jet and associated atmospheric circulation plays in the transport of mineral dust from the Sahara desert to the Arctic across eastern side of the North Atlantic Ocean.

A meandering polar jet was discovered as responsible for both the emission and transport of dust from Northwest Africa to the Arctic. The emission has been linked to an intense Saharan cyclone that formed in early April 2011, which was caused by the intrusion of an upper-level trough emanating from the polar jet.

The study has found that atmospheric circulation of this nature enables the transport of dust, warm and moist air masses from subtropics and mid-latitudes to the Arctic, where approximately half of the warming is now being attributed to increased 

moisture and heat fluxes transported to the region.

The warm and moist air masses accompanying the Saharan dust caused a rise in surface temperature of 10C for more than three consecutive days upon reaching southeastern Greenland. Subsequent temperature observations detected increased melting within the ice across this same area.

"The polar jet stream has been identified as the main driver for such events leading 

to the transport of large amount of dust to high-latitudes," said Diana Francis, atmospheric scientist at NYU Abu Dhabi and lead research scientist in this study.

"If the polar jet is set to slow more frequently due to the changes in the Arctic climate system and to the Arctic Amplification, such events are expected to become more frequent," Francis added.

The newly discovered poleward route is considered the most substantial in terms of dust load import into the Arctic, due to the minimal geographical distance between 

the origin point and the destination.

'The impact of dust deposition on ice in Greenland, such as darkening ice and formation of algae on ice or cryoconite, as well as the link between Saharan dust transport and the Arctic heat dome must be investigated further in collaboration with scientists in UK and Germany' Francis emphasized.

Today it is below 1000 hPa in parts of the Arctic