...
Status:
...
Finalized Material from: Ivan, Linus, DMI
Discussed in the following Daily reports:
| Show If | ||
|---|---|---|
| ||
1. Impact
An episode of extremely warm conditions were observed over the North Pole in mid April. The analysis suggests that the warmest period was between 15 and 17 April, when a southerly flow brought warm air. After that quite cold weather came back over the Pole.
...
For the warmest period from 15 to 17 April significant anomalies could be seen over the North Pole in the figure above. They seem more pronounced for the 2-metre temperature compared to T at 850 hPa. Significant positive anomaly can be noticed over Europe form the Mediterranean up to England and Germany caused by warm advection from North Africa. It also appears to be quite cold for the season over Africa. All the anomalies displayed are calculated from ECMWF analysis versus ERA-Interim.
The plot above shows the SST anomaly and sea-ice cover for the 17 April. The normal sea-ice cover is inside the purple line. West of Svalbard the SSTs are somewhat warmer than normal but the sea-ice cover was almost normal.
3. Predictability
3.1 Data assimilation
3.2 HRES
The figure below shows a short forecast for 2-metre temperatures and observations north of 70N. For the area of anomalous temperatures we only have observations from Svalbard and Franz Josefs Land, but no observations close to the North Pole.
3.3 ENS
The 17 April seems the warmest day over the Pole with daily mean temperature anomalies of the order of 20C (top panel in the figure below). The plot below shows the the EFI and SOT for 2-metre temperature for a 1-day forecast (bottom-left) and 7-day foecast (bottom-right)The predictability of this extremes is quite high. EFI for D+7 show a strong signal with positive SOT denoting a chance of temperatures to go beyond the climate.
...