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Weather overview and short-term outlook to Wednesday 24 February 2021

Weather overview and short-term outlook to Wednesday 24 February 2021

Visual: Synoptic map for southern Africa as on 16:00 Friday 19 February

Source: 1stweather.com, http://clients.customweather.com/1STWX/plots/AVN_mslp_small_day1.gif

Recent Developments

The rain season so far has been relatively cool compared to a typical Namibian January and compared to the blistering temperatures we had to endure during November and the first three weeks of December.

One would expect that the very good rainfall so far would be good for grazing in general but an interesting biological anomaly is slowly appearing in the Otjozondjupa, Omaheke and Kavango West regions. Despite the more than adequate rainfall, 700 mm+ in many areas, the grass biomass is disappointingly low and this purely because of the persistent cloud cover in the central and north-eastern districts. Grass needs a certain level of precipitation but then it needs heat from solar energy and when this is absent, its growth is stunted.

The visual chosen for this week is from Customweather, a source not known for its accuracy but rather for its splendid techni-colour maps and charts, shows the location of the tropical cyclone, Guambe, offshore southern Mozambique.

Guambe has created somewhat of a stir in Namibia as many people expect it to have an “afterflow” that will eventually reach us in about a week. Alas, that will not happen. Guambe is too far south to join any of the conveyors that bring us rain, but it will certainly create havoc in Mozambique and South Africa’s Kwa-Zulu Natal province, much like Domoina in 1984.

For the past two weeks our local weather was very predictable, following a typical late January pattern, with intermittent cloud formation and isolated, but strong, showers, more or less up to or near to the escarpment. Nothing much happening on the rainfall side except for Kavango West, Kavango East, the former Bushmanland and Bwabwata, for it has been raining cats and dogs for a fortnight, and will continue to do so.

On the Radar

Cyclone Guambe will carry on with its destruction until Sunday at which point the approaching South Atlantic high pressure cell will deflect it to the south-east. Not a drop from Guambe will reach us and the weekend will continue much the same as the past week.

Cloud formation will take place daily, and isolated to scattered thunder showers can expected over the central plateau, the eastern section on the border with Botswana, and perhaps as far south as Aminuis.

The rain in Kavango West, Kavango East, Bwabwata, Otjozondjupa and the northern half of Omaheke will continue every day, perhaps for another 10 days.

By Monday evening there is a noticeable disturbance over the Kaudum area at the 500 mB level (18,000 feet). At this stage it looks as if the chances are very good for a cyclonic depression forming over the north-eastern quadrant but south of Kavango West. The epicentre will be somewhere between the eastern section of Otjozondjupa and the northern part of Omaheke.

When that happens as expected, a rain windows opens for the interior and from about Tuesday evening or Wednesday, we can expect good rainfall over most of the eastern half, but still with a reasonable chance for the western half up to the escarpment.

On Wednesday and Thursday next week, the chances are also good that this wet intrusion may get to the central and eastern parts of both the Hardap and Karas regions. Depending on the strength and duration of the cyclonic depression, we may just enter another 10-day wet spell.


 

About The Author

Weatherman

In Memoriam. The weekly weather column is compiled by the editor in honour of the legacy of John Olszewski, the widely respected and well-known weatherman of Namibia. After writing the weather column for more than twelve years, he has left an indelible mark at the Economist, and the technical ability among the editorial staff to "read" the maps that he so often consulted. - Ed.


Rain Rate >UTC + 2 hrs = Namibian Time<