WASM-
The WASM Regional Center issues the monthly bulletin
for December 2024, which indicates a delay in major weather depressions affecting Jordan until the second week of December, based on data from the WASM Regional Center's climate model, which was updated on 2-12-2024. Some clear changes were observed regarding the time periods at the beginning of the weather depressions' impact, which is expected to concentrate during the last days of the month.
Jordan is expected to experience stable weather with some scattered rainy cases during the beginning of the month as a result of weak weather depressions that remain distant from the kingdom's atmosphere, with expectations of weather depressions approaching the kingdom's atmosphere again during the second week of the month and gradually.
Details|
From 1 to 7 December| .. A stable and cold period with expectations of light rainfall during the middle of this period.
From 8-17 December| Gradual return of weather depressions activity to the kingdom's atmosphere, which is expected to begin with a rainy case during the beginning of this period and end with a cold weather depression, with good amounts of rainfall expected during the middle of this month.
From 18-23 December| A stable and warm period affects the kingdom, and it is expected to be a temporary stabilization.
From 24-31 December| A very cold and humid period with expectations of successive weather depressions continuing, and it is expected to result in large amounts of rainfall and snow chances are possible but weakly.
Snow Chances|
Snow chances are weak during this month and increase during two periods. The first is around 13-16 December (we do not expect it to be significant), and the second during the last days of the month, which is expected to have good chances and likely to improve, as the characteristics of wet, rainy and cold weather depressions will prevail at the same time due to the polar jet stream's distance from the kingdom's atmosphere. Snow chances are mostly confined above the peaks of high mountains, especially during the last days of the month, and changes are possible if the time period approaches.
Rainfall Amounts|
This month is expected to record again rainfall amounts higher than the averages as has been the case during the previous month, especially in the northern regions and the western and central parts of the country. Most rainfall amounts are expected to be recorded during the last days of the month, and we expect good amounts during the middle of the month.
This month will appear dry during the first 3 weeks of its beginning, but performance will improve significantly during the last week of it, and we do not expect a complete cessation of rainfall as it will renew at an acceptable rate during the second week of this month.
Temperatures|
Temperatures are generally below average, but they rise slightly above their seasonal averages during the first half of this month, and begin to drop significantly below their seasonal averages during the last week of the month with expectations of a very cold and humid wave occurring.
Atmospheric Layer Analysis|
Atmospheric data obtained at 500 millibars levels as well as at 850 millibars level clearly indicate the dominance of a high pressure system toward western Europe and is expected to gradually extend toward its center, and will take a west-east pattern, meaning the polar jet stream will remain distant from the kingdom's atmosphere. This means the distance of major polar air masses from the eastern Mediterranean region, especially during the period between 1 to 18 December (meaning there will be rainy, cold and humid weather depressions).
However, some gradual changes are expected to occur after 23 December, as the influence of the European high pressure system toward northern Europe and its center will increase, meaning polar air masses are gradually approaching the kingdom's atmosphere during the last days of the month, and our expectations are for their main impact on the region at a later time.
The reason for the polar jet stream's inability to affect the eastern Mediterranean is due to several important effects during this month, which is the intensification of North Atlantic storms through northern Europe during the first two-thirds of the month. However, the expected changes with the beginning of the Murabbaniyah period will increase the chances of polar air masses reaching the kingdom with changes in atmospheric organization.
We expect significant weather depressions in the region, especially during the period between 13 to 18 December, as well as during the last week of the month. These weather depressions are expected to bring important rainfall amounts to the region as a whole.
Despite the previous optimistic results that these weather depressions would begin around the middle of the first week of December, the new results reflected some minor changes in the time period only, due to more than expected activity in North Atlantic storms and these changes were incorporated into our climate model data, which reflected only changes in the time period.
Jordan | Monthly Report for December 2024 | Late Onset of Weather Depressions Until the Second Week of the Month
