Jordan News

Jordanians usually use the term “Khamasini Low” at the end of the winter season and during the spring, which is accompanied by dusty weather conditions and a temperature difference between a noticeable rise and a significant decrease within a short period.

According to the MENA Weather platform, the pentagonal depressions are the depressions that form in the eastern slopes of the Atlas Mountains in central and western Algeria and move parallel to the coasts of the Mediterranean Sea from Algeria to Tunisia, then Libya and Egypt to the Levant, Iraq and Turkey.

As for the time of their impact, they usually begin to form with the beginning of the astronomical season (vernal equinox, March 22) and last for 50 days, which is why they are called the quinquennial depressions (i.e. their effect lasts 50 days in most years).

With regard to the reason for its formation, with the movement of the earth towards the north with the vernal equinox, the land temperature begins to increase more than the coastal areas; Therefore, the atmospheric pressure decreases as the temperature rises in the valleys, which results in dynamic instability in the layers of the atmosphere due to the thermal difference of the air masses (cold over the sea and warm over the land).

The Atlas Mountains in the northwest of the African continent play a dynamic role in increasing the cyclonic movement of the winds accompanying the depression in the eastern slopes of the mountain range.

The five-year depressions are also accompanied by a warm front, dusty weather, active winds, and possibly a state of atmospheric instability, then a cold air front and a relatively cold or cold mass that causes rain in some areas.

It is worth noting that the five-year depressions are not considered one of the main pressure systems that lead to heat waves in the Levant, where the effect of the accompanying heat rise is limited to a day or two at most, after which the cold part of the depression enters.

Note that one of the conditions for naming a heat wave is that it persists for more than 3-4 days, and it is rare for heat waves to occur during the period in which the five-year depressions are active, and heat waves often cause heights in the upper layers of the atmosphere and not depressions.

Next Sunday, Jordan will be gradually affected by the first Khamasini air depression for this season, as it will be deep and center north of Egypt.

According to the forecasts of the Arab Weather Center, temperatures are rising significantly and becoming warmer than the usual rates for this time of the year by about (7-9) degrees Celsius.

It is expected that five-year weather conditions, which are warm, dry and very dusty, will prevail in most regions, with the appearance of clouds at different altitudes, which are expected to be associated with rain showers in random areas of the Kingdom.

Later in the day, thick dust waves are expected to erupt, which will lead to a significant decrease in horizontal visibility and possibly its absence on a number of external roads.