Michael Bentrice: Jeez! It's going to be so cold SE Scandi/E Europe this Friday that our maps cannot shade the anomaly! -20C+
https://twitter.com/mjventrice/status/684488025456381952
something must be wrong with this map because the anomalies show i.e. -23C whereas the forecast temps for friday for that (and all other ) regions on this map rather correspond with the numbers show as anomalies. so if the temp is for example -23 it cannot be 23C below normal because by no means is the normal january temp in finland 0C. to me the temps shown as anomalies seem to be totally normal while daily anomalies do not have much meaning since daily temps are mostly due to weather patterns and come in go within days or even hours.
The map shows the
difference between the
forecast average temperature and the
historical average temperature.
For example, I found a forecast average temperature for Helsinki, Finland for Friday of about -14°C. Whereas the historical average temperature for Helsinki for January 8 is about -3°C. The forecast abnormality is thus about 11°C lower than normal, or -11°C.
Looking at Madrid, Spain: Forecast for Friday is about 11°C, whereas the normal would be about 5°C. A forecast of a 6° abnormality in the warmer (positive) direction, or +6°, indicated on the map by orange colors.
The temperature data I found with a quick Google search may not match the map data exactly, but the trend shown is the same.
You are correct that this is only one day's weather. However, this abnormality is noteworthy because, as modeled, the degree of expected temperature variance is so unusual and unexpected that it is "off the scale." Climate Reanalyzer 5-day average also shows an extremely cold temperature
anomaly (departure from average) in Scandinavia -- about as cold a departure from average as the map can show....