Monthly Climate Summary December 2019

 1. Rainfall Performance Doc No: TEA 3/3/7/1 F-009 In This Bulletin  2. ENSO status and forecast Revision No: 1  3. Rainfall forecast Effective Date: 01.07.2017 Approved by:

1.Rainfall 1.1 Spatial Distribution

The good rainfall which was observed in November continued to be received in Decem- ber. The majority of reporting stations reported rainfall which was in the category of normal to above normal rainfall with exceptions being areas in the northern Lubombo and southern Shiselweni where slightly below average rainfall was received (see fig 2). The spatial distribution of the November rainfall followed the traditional patterns with areas in the Highveld and Middleveld receiving more rainfall than those in the Lowveld (fig.1). Mbabane, Nkhaba and Motshane Tinkhudla received the most rainfall while Si- phofaneni, Sithobela , Sigwe and Lubuli were the Tinkhudla receiving the least amount of Rainfall. Khubutha , Lamgabhi and neighbouring Tinkhudla’s received the highest amounts of rainfall when compared to their 30 year average with some reporting over 175 percent of their normal rainfall for the month.

Fig 1. Fig 2. 2

1.2 Actual Recorded Rainfall

Higher than long term average rainfall was reported in Mbabane, Matsapha, Malk- erns, Sithobela, Khubutha and Piggs Peak. Mbabane had the highest monthly rainfall total of 247 mm followed by Malkerns with a monthly total of 230 mm. Only Nhlangano and Mananga reported rainfall which was below the long term average recording 115 and 86 mm respectively.

300 250 December 2019 Rainfall Totals 200 150 LT-Ave 100 Rainfall Rainfall (MM) 2019-Rain 50 0

Fig 3

1.2 Temporal distribution of Rainfall

The first dekad of the month received the most of the rainfall occurring in the reporting month. The rest of the month was relatively dry with 3-4 days reporting rainfall in 20 day period. The highest daily rainfall collection in a majority of reporting stations was on the 8th of December. Mbabane (see fig4) in the Highveld reported 76.7 mm on that day whilst Mananga (see Fig 5)in the Lowveld 25.5 mm. Sta- tions in the Lowveld also recorded the least total number of rainy days when compared to stations in the Highveld. Mananga had a total of 7 rainy days while Mba- bane had a total of 13 days.

Mananga Daily Rainfall Mbabane Daily Rainfall 30 100 20 50 10

0 0 Rainfall Rainfall (MM) Rainfall Rainfall (MM) 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 1 3 5 7 9 1113151719212325272931 Dates Dates

Fig 4 Fig 5 3 2. 0 ENSO OUTLOOK

Currently in an INACTIVE mode (see fig 6), the ENSO outlook implies that there is a minimal chance of El Nino or La Nina forming in the coming months with at least 60% chance that this will be the case through out autumn . A majority of the climate mod- els also favour an ENSO neutral condition through-out the southern hemisphere sum- mer (see fig 7). Because of the neutral ENSO condition, other climate drivers influence our climate. The position of the zonal arm of the Inter-Tropical Convergence Zone (ITCZ) over our country mid-end of January is expected to enhance rainfall in the Kingdom.

Fig 6 Fig 7

3.0 Rainfall Forecast (February-March-April)

The predictors used put most of the country in Normal-to-Above-Normal rainfall over the forecast period with only Zone III in the Normal to Below Normal Cate- gory. The regional breakdown of the predicted February-March-April (FMA) 2020 rainfall probabilities are as presented below

Fig 8. 4

© Eswatini Meteorological Services Additional ENSO information obtained from: Ministry of tourism and Environmental *Bureau of Meteorology in Australia, Http:// Affairs www.bom.gov.au P.O. Box 2652 *National Oceanic and Atmospheric Administration Mbabane (NOAA). Phone (+268) 24046274/24048859 * IRI Fax (+268) 24041530 E-mail: [email protected] http:www.swazimet.gov.sz