Polar Low

[Konstantinos]

In this thread we will discuss everything about polar low.

Wikipedia:

A polar low is a small-scale, short-lived atmospheric low pressure system (depression) that is found over the ocean areas poleward of the main polar front in both the Northern and Southern Hemispheres. The systems usually have a horizontal length scale of less than 1,000 kilometres (620 mi) and exist for no more than a couple of days. They are part of the larger class of mesoscale weather systems. Polar lows can be difficult to detect using conventional weather reports and are a hazard to high-latitude operations, such as shipping and gas and oil platforms. Polar lows have been referred to by many other terms, such as polar mesoscale vortex, Arctic hurricane, Arctic low, and cold air depression. Today the term is usually reserved for the more vigorous systems that have near-surface winds of at least 17 m/s (38 mph).

http://en.wikipedia.org/wiki/Polar_low

Every tropical depression - storm in Mediterranean is called Polar Low. Right?

[summer blizzard]

In this thread we will discuss everything about polar low.

Wikipedia:

A polar low is a small-scale, short-lived atmospheric low pressure system (depression) that is found over the ocean areas poleward of the main polar front in both the Northern and Southern Hemispheres. The systems usually have a horizontal length scale of less than 1,000 kilometres (620 mi) and exist for no more than a couple of days. They are part of the larger class of mesoscale weather systems. Polar lows can be difficult to detect using conventional weather reports and are a hazard to high-latitude operations, such as shipping and gas and oil platforms. Polar lows have been referred to by many other terms, such as polar mesoscale vortex, Arctic hurricane, Arctic low, and cold air depression. Today the term is usually reserved for the more vigorous systems that have near-surface winds of at least 17 m/s (38 mph).

http://en.wikipedia.org/wiki/Polar_low

Every tropical depression - storm in Mediterranean is called Polar Low. Right?

 

Not all systems in the Med are Polar Lows as some do have documented warm cores and were therefore akin to the Atlantic hybrids or fully tropical.

 

Notably the following had documented warm cores..

 

January 23–27, 1982

 

 

 

A well-defined warm core had emerged at the center of the storm, with temperatures 6~8 warmer than the cold air to the northwest of the storm.

 

 

September 12–13, 1996

 

Waters in September are warm enough ~(generally 24-28C)

 

 

October 4–6, 1996

 

Satellite looks a bit sub-tropical.

 

 

October 6–11, 1996

 

Low shear, warm core, forecast by models for several days.

 

 

 

March 27–28, 1999

 

Developed some kind of warm core but was probably sub-tropical.

 

 

 

September 16–19, 2003

 

Formed over 27C waters.

 

 

 

September 28–29, 2003

 

Tropical Storm, radar image was also tropical with the classic big blob look.

 

 

 

October 17–19, 2003

 

Probably a hurricane.

 

 

 

October 26–28, 2005

 

Tropical Storm.

 

 

 

September 26–27, 2006

 

Warm core, very much a v shape pressure observation (classic in the tropics).

 

 

January 27–29, 2009

 

Sub-Tropical storm, observed warm core.

 

 

November 2011

 

 Satellite Services Division and NESDIS both classified the storm as Tropical Storm 01M

[summer blizzard]

The September 12th 1996 looks similar to how something tropical may develop..

 

 

As does October 4th-6th and the one that spawned afterward..

 

 

 

The 2006 one..

 

 

And the Nov 11 one..

 

 

 

........

 

Have to say having looked at all the charts it's not the most fertile environment. Generally you either get a frontal wave splitting, stalling and then going tropical (similar to a lot of early season Atlantic storms) however that takes days and by that time they've hit land. You do get the classic shower development but a lot of time there under a deep layer anti-cyclone which could easily kill the moisture. The examples above of success are quite profound.

[Somerset Squall]

I didn't realise there were 3 tropical systems in 2003! You could almost call that a season lol.

[Konstantinos]

Not all systems in the Med are Polar Lows as some do have documented warm cores and were therefore akin to the Atlantic hybrids or fully tropical.

I did not understand the definition from wikipedia. If a system has near-surface winds of at least 17 m/s (38 mph), it is not enough for calling it Polar Low?

[Su Campu]

Konstantinos, have a look at this excellent tutorial on polar lows.

http://www.eumetrain.org/resources/mfc_2013_s9.html