December 2016 places Portugal in weak drought situation
2017-01-06 (IPMA)
December 2016, in Portugal mainland, was classified as very dry regarding the amount of precipitation and normal regarding air temperature.
In the first half of December, the territory was under the influence of a few complex low pressure systems associated with frontal surfaces. Between December 1st and 5th precipitation occurred, being sometimes strong and accompanied by thunderstorm in the Center and South regions. In the period of 13th to 16th, due to the approach and passage of a frontal system of moderate to strong activity, there were periods of precipitation in the form of rain or showers and occasionally hail accompanied by thunder. During these days there was also snowfall, above 800 to 1200 m, in the northern and central interior. Since in the second half of the month practically no precipitation occurred the total precipitation observed was about 46% of the normal, which classifies this month as very dry.
Thus, at the end of December there was an increase in the area in weak drought situation, with about 78% of the area in the dry class.
The average value of the average air temperature in December was 10.41°C, 0.44°C above the normal value. The mean value of maximum temperature, 15.26°C, was higher than the normal value, with an anomaly of +1.38°C, this month being the 2nd month of December with the highest value since 1931. The mean value of the minimum air temperature, 5.55°C was below the normal value, with an anomaly of -0.50°C.
From 17th December, the mean values of minimum air temperature remained below normal until the end of the month. Of note is the 20th that recorded very low values of temperature in most of the North and Center regions, in the Northeast region and also in the interior of the Alentejo, and in some places in the interior of the Alentejo the temperature values were bellow 0°C. The lowest minimum air temperature recorded was - 7°C, on the 30th, at Miranda do Douro.
