Climate Scenarios of June-September 2022 in Kenya

Climate Scenarios of June-September 2022 in Kenya

This forecast was issued in May 2022 and is based on Astronomical Cycles of Jupiter, Saturn, Mercury, Venus and the Moon on experimental basis. The cycles are referenced on key phases of the planets, e.g. Conjunctions and oppositions of the planets as well as the Moon's Apogee-Perigee and Full Moon-New Moon phases.

The General JJAS Season Conditions

The June-September 2022 (JJAS-2022) season is regarded as the cold season of the region. The month of June normally marks the beginning of the season but may have rains as an extension of the MAM season especially over the coast and western areas of Kenya. In the month of July the cold conditions intensify and in many cases marks the peak of the season. While most of the areas remain dry in July, the coastal region and the western parts of Kenya may have occasional light rains from time to time. The cold conditions may extend to the month of August and in most cases the cold conditions may cease thus ushering in a hot and dusty condition that runs into September. However, in the month of August, some areas in the highlands of Kenya may exhibit a peak in rainfall that doesn’t last long. The month of September is normally dry and hot for most areas.

Summary Forecast

The season is likely to shift from one condition to the opposite in a cycle that may be repeated over and over again throughout the period June to September. We are likely to have rainfall being experienced in two main periods; the first is, from the 2nd week of June to the 1st week of July, and the second one is the middle of August 2022. It is likely that the rainfall may be significant in the 4th week and 1st week of July in many areas except some areas in the northwest. In August, the rains will concentrate mainly in the rift valley and the highlands to the east (Table 1). In September, there is likelihood of occasional rains in the 3rd / 4th week due to incursions of the ITCZ from the north which may affect mainly the extreme northern sector and to some extent the eastern half of the country.


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The season will be generally cooler than normal but may be interrupted by relatively warm episodes from time to time in many areas especially in the northern and eastern sector counties. The cold conditions will be felt in three phases; one, the 2nd week of June to the 1st week of July; two; the 4th week of July to the 2nd week of August; and three; most of the month of September 2022 (Table 2). The month of June will be dominated by mix cold wet conditions extending into the 1st half of July. It will be followed by a cool / dry condition in the last half of July with a peak in cold conditions towards the end of July and early August. The last half of August will be relatively warm and dry but the month of September will be dominated by cool / dry conditions in many areas especially the eastern sector. These conditions will interrupted by warm / dry conditions from time to time.

Disclaimer

The forecasted conditions may deviate due to influences of other non-astronomical factors, e.g. ENSO, IOD an MJO. However, MJO has been given a special consideration for those interested in seeing how climate conditions associated ?with it interacts with the main forecast.

The MJO and Associated Climate Conditions in Kenya

In the past the forecasts done have been found to deviate from the intended conditions due to influences of other climate drivers that are not incorporated in the forecasts. Three climate drivers come into the picture; ENSO, IOD and Madden-Julian Oscillation (MJO). While the first two are fairly stable, MJO is highly unstable and unreliable in seasonal forecasting. The MJO is associated with weekly to monthly periods of enhanced and suppressed rainfall in many parts of the tropical world that includes Kenya which lies across the Equator approximately between latitudes 5oN and 5oS.

Past experiences have shown that the MJO is a significant causative factor of climate conditions in Kenya. Its evolution is highly erratic and therefore its prediction skill is fairly low even within 14 days and the skill is almost negligible beyond two weeks.?In the last two seasons, MJO was found to have altered or shifted the periods of forecasted rainfall by as much as 1-2 weeks in some instances, however, most of the key conditions forecasted remained as forecasted.?This is a little setback to our astronomical based predictions.

For the last 10 years, it has been observed that the evolution of MJO goes with a certain persistent climate pattern in Kenya throughout the year. After observations between 2010 and 2021, a phase diagram with the climate conditions in Kenya which are associated with each of the 8 phases was developed and is provided here (see Figure below).?It is meant to assist the reader with a better picture of the conditions in Kenya and you can tell what kind of conditions that are likely to dominate with a 2 weeks lead time by referring to the phase diagram provided by;

BOM ( https://www.bom.gov.au/climate/mjo/ ) or

NOAA (https://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml )

By comparing the two scenarios (the forecast and the MJO climate conditions) you will likely get a better picture of the general conditions as the season progresses.

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Figure 1: Common climate conditions in Kenya and associated 8 phases of the MJO ( based on the MJO phase diagram).?

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