Will it rain or snow again before the end of 2023? And before the end of the celebrations?

Days go by and the year goes by. Options for seeing rain are shrinking and annual rainfall records are increasingly meager. Rain will be the biggest absentee at the beginning of the Christmas holiday, as well as snow. Maps hint Some light around discount time, between December 29th and 31st.

Anticyclone weather at the start of the Christmas holidays

The Azores anticyclone will once again approach the Iberian Peninsula and southwestern Europe from the end of the week. Resolving high pressures on Catalonia It will completely stabilize the atmosphere and enhance the presence of fog inside. Thermal investment will also return to the mountains, where it will be particularly warm Temperature values are more typical in spring Or mid-autumn.

On Christmas and Saint Stephen’s Day, maximum temperatures are expected to reach around 10°C at an altitude of 2,000 meters and lows between 5 and 8°C at this level. Spring atmosphere in the Pyrenees with the predominance of the sun.
On the coast and pre-coast, the sun also shines and the weather is pleasant at noon, with maximum temperatures ranging between 16 and 18 degrees Celsius on average.
On the other hand, the weather will be quite wintery in Ponent and inland points due to the presence of fog. Fog will persist in the Terra Firma region and parts of the Ebro Valley, as well as in some parts of the Central Plateau and the Segre Valley. In this environment the maximum temperature can be less than 5°C.

The anticyclone weakens before the end of 2023

Atmospheric stability can begin to deteriorate Middle of next week. Although there is still strong uncertainty, Two major weather forecasting centers (GFS and ECMWF) Bet on one Gradual drop in temperatures in the highlands As of December 27, in addition to weakening high pressures.

Between days December 29 and 31 A few days ago, the maps hinted at the possibility of some more significant changes. It will likely arrive accompanied by a deep Atlantic storm and a trough of cold air aloft. Right now, it doesn’t look like it will directly affect Catalonia, but it will This could bring some scattered rain and snow north of the Pyrenees.

The uncertainty at the moment is high and it will be necessary to follow whether this possibility will remain in the next outputs of meteorological models or whether it will end up disappearing. However, this will be the last chance in 2023 for a slight increase in precipitation calculations From meteorological observatories.

The NAO is also seeing a weakening anticyclone ahead of the new year

Indicator NAO (North Atlantic Oscillation) It is an indicator that allows you to understand the composition of the atmosphere on a global scale. This is a useful indicator for predicting how action centers (anticyclones and storms) in the Iberian Peninsula, Catalonia and Western Europe will move in the medium term.

This indicator measures Atmospheric pressure difference At sea level between Iceland and the AzoresWhich gives us an idea of the size or strength of the anticyclone, which indicates stability in the Iberian Peninsula, as it prevents the arrival of cold air storms. This NAO has Two stages: the positive that day negative. the Positive phase Refers to a very strong Azores hurricane and low pressure in Iceland, implying a Regional circulation At high latitudes. Usually, with the positive phase of our NAO Lovely time. Instead of that, Negative phase It consists of the weakening of the anticyclone in the Azores and its displacement with respect to its usual place, which allows this Clearing cold air areasThe spread of storms at low latitudes and the passage of the jet stream over the Iberian Peninsula.

Development and forecasts of the NAO index. Source: NOAA

according to Forecast carried out by the US agency NOAA, NAO index (Currently clearly positive) it will tend to approach neutrality in the coming days and will even be slightly negative on New Year’s Day. This fact is consistent with the forecasts of the ECMWF and GFS models, which bet on the weakening of the anticyclone and the approach of storms at the end of December.

Nothing is certain in the first week of January

European Center for Medium-Range Weather Forecasts (ECMWF) weekly maps They hint that the first week January can be generally dry, more than usual in Catalonia. Maps show more than normal rainfall across the European Atlantic Front and towards the Cantabria region, a fact that indicates the passage of Atlantic storms that may reach Catalonia further.

No clear trend can be seen regarding January rainfall in the case of Catalonia. NOAA’s monthly model in North America predicts much more rain than normal in the western Iberian Peninsula. However, we must remember that these forecasts are low in reliability and usually only hint, at best, at the general trend.