Life story

 

High pressure system ZHYGIMONT

(baptized on the 30th of December 2016)

 

Being the last high pressure system named by the Berliner Wetterkarte in 2016, the anticyclone ZHYGIMONT was located over Newfoundland at the end of December. On the 30th of December the high pressure area ZHYGIMONT was predicted for the following day. With an air pressure of 1025 hPa the anticyclone ZHYGIMONT extended over a large area of the eastern United States and over the North Atlantic.

On the following day the anticyclone ZHYGIMONT was centered over the North Atlantic southward of Greenland with an atmospheric pressure set at 1030 hPa. The anticyclone was embedded in a high-pressure area in the 500 hPa level, that means in about 5 km height, which was spreading to Greenland and is called a ridge.

Following the direction of the prevailing winds in 5 km height, on the 1st of January, the anticyclone ZHYGIMONT was analyzed in ground-level over the south of Greenland as well as over Iceland. The air pressure increased from 1030 to
1040 hPa. Due to the characteristics of high pressure systems, air mass is sinking; thus, the anticyclone was causing a rainless day with maximum temperatures of 3 to 2C in Iceland, while Scandinavia was influenced by the low pressure system CORINNA I, and its weather fronts that were bringing rain.

On the following day, the relatively stable anticyclone ZHYGIMONT approached from the North Atlantic to influence the weather on the British Isles. In the center of the high pressure area over the North Atlantic, located northwestern from Ireland and southern from Iceland, the air pressure already reached 1045 hPa. Due to maritime sub polar air flowing to Iceland, temperatures increased up to 11C at the meteorological station Dalatangi in eastern Iceland. The cold front of the cyclone CORINNA was bringing precipitation mostly to the southern parts of England; up to 9 l/m in St. Catherines Pt. in 24 hours until 7 pm, whereas in Scotland, Wales and Ireland it remained less wet. Sunshine duration was measured between 6 and 7 hours in England, but only 0 to 1 in Scotland where the sky was covered with clouds by the cyclone AXEL, which was situated between Greenland as well as Iceland at 1 am. Maximum temperatures reached 7C in Plymouth, West Freugh or Stornoway; weather stations located at higher altitudes recorded maximum temperatures of -2C in Aonach Mor and Cairnwell as well as -4C on Cairngorm Mountains.

On the 3rd of January the high reaching anticyclone ZHYGIMONT was located in the west of the British Isles without having changed the position significantly, but under declining air pressure that reached about 1035 hPa. The high pressure system ZHYGIMONT was surrounded by prevailing northern winds in 500 hPa that were extending to Central Europe, as well as a low pressure system over the Azores. The weakening anticyclone ZHYGIMONT spread from large areas over the North Atlantic, over Great Britain to Western Europe. Especially the coastal zones in France experienced a sunny day with sunshine duration of 7 to 8 hours, like Quimper, Dinard/Pleurtuit or Cherbourgh/Maupertus. It remained dry in France and most parts of England, except of low amounts of precipitation in southern England, such as Charlwood with 0.2 l/m or Bournemouth with the same amount of rainfall due to the low pressure system AXEL over the Norwegian Sea. In the maritime sub polar air, temperatures rose up to 9C in La Hague or 5C in Le Talut, whereas in centrally located regions of France, temperatures dropped to values below the freezing point.

Surrounded by the low pressure system AXEL now over the Baltic Sea and an unnamed cyclone in the west, the spatial expansion the anticyclone ZHYGIMONT was reduced until the 4th of January. One center of the system was situated northwestern of Ireland, another one over the western coast of France. Since the northern parts of the country were already influenced by the cold front from the cyclone AXEL, regions like the Normandy remained without sunshine. In the North Atlantic Sea, maximum air temperatures were rising by a few degrees in comparison to the day before, so that La Hague reported 10C, Paris 6C and Nancy/Essey 3C.

On the 5th of January the anticyclone ZHYGIMONT covered an area that included Great Britain and Ireland, as well as the Gulf of Biscaya. The air pressure of the system remained unchanged at 1030 hPa. Nevertheless, the anticyclone ZHYGIMONT was more and more incorporated by the high pressure system ANGELIKA that was centered over Scandinavia showing low temperatures up to -20C in the 850 hPa level at a height of 1.5 km. The clear sky was leading to sunshine for 6 to 7 hours during the day and frosty weather at night with cooling down to -8C in Benson, -5C in London and also down to -8C in the Scottish Highlands.

However, the anticyclone ZHYGIMONT weakened further, so that it could not be analyzed on the meteorological maps of the Berliner Wetterkarte on the following day. Therefore, on the 5th of January the high pressure system appeared for the last time on our weather maps.

 

 

Geschrieben am 19.01.2017 von Natja Bublitz

Berliner Wetterkarte: 05.01.2017

Pate: Yuri Zisser