Monitoring Weather Hazards in Uganda

ByCatherine Mulinde Kafeero

MeteorologistDepartment of Meteorology

Uganda and its neighbours

• Severe local storms - small scale hazardous weather or hydrological events produced by thunderstorms, large hail, damaging winds or flash floods.

• Other hazards - extreme heat or cold, dense fog, high winds, river flooding, and lakeshore flooding.

Severe Weather Events

Severe Weather Thresholds

• Precipitation - ≥ 30mm/24hrs• Winds - ≥ 20knots• Temperatures - ≥ 350 C

Drought Risk in Africa - Uganda

Drought affected areas in Uganda

On March 2, 2012, a landslide in Bududa (Eastern Uganda) left 300 people dead, loss of property and thousands homeless.

•However, the DoM had issued a warning which was rather ignored.

The residents look-on helpless after the occurrence of the landslide while they resorted to using hand hoes with hope of rescuing their loved ones with the help of army soldiers (UPDF).

The landslides were attributed to widespread deforestation on the slopes of Mt. Elgon.

Deforestation is one of the threats to environmental sustainability in the country

Floods are common in Kampala; the capital city of Uganda, western, central and Eastern regions especially during the El-Niño phenomenon.

They damage structures, crops, animals and settlements.

Water borne diseases like cholera, dysentery, and typhoid are also common.

Teso Flash Floods of Sept, 2007

Stranded villagers in Teso awaiting rescue when floods swept away their property

Floods disrupted and paralysed traffic in Teso

Landslides buried,destroyed and damaged homes

Landslide in upper Bulambuli in Sisiyi sub county

Some flooded homes in Bulambuli

Floods in Kampala

In Sebei sub region, Kween district, ngenge subcounty where floods have displaced over

5000 people due to severe rains.

SWFDP workshop, 28 Nov . 03 Dec 2011, Arusha, Tanzania

Floods in lower Bulambuli district

Due to land-lake breeze effect, Lake Victoria basin is reported with the highest average annual frequency of lightning and thunderstorms in the world (Bukoba reports 226 days per year, Kampala 222 days, Entebbe 211days and Kisumu 202 days). More than 800 people in May 1995 were capsized in Lake Victoria

June, 2011 - 22 students and a teacher died after lightning struck their school in the country’s mid-west. In another school, northwest of Kampala – 37 students and two teachers were killed

October, 2012 - Three radio stations also say recent lightning has damaged their transmission equipment

Coverage of case study: Kalangala Islands Coverage of case study: Kalangala Islands

Forecast Tools employed

Synoptic Chart Analysis,Ensemble Forecast,Probabilities and NWP guidance (HRM,

WRF, NCEP, UKMO, ECMWF)Precipitation maps from NOAA and UK

Africa LAM.Satellite Imageries from Eumetsat

Southern Africa Synoptic AnalysisSt. Helena and the Mascarene anticyclones were tremendously weakened by the numerous low pressure systems in their vicinity

As a result the zonal arm of the ITCZ was mainly confined to the southern sector of the country

The meridional arm of the ITCZ was also over our region

MSL and 850hpa wind speed

700hpa Relative Humidity and Winds Relative humidity

levels around Lake Victoria varied between 80% and 95%

These high humidity levels were as a result of moist southwesterly winds blown over our region by the maritime portion of the Mascarene anticyclone

UK Lam Precipitation maps

• UK LAM showed strong signal for relatively heavy precipitation in the Northern and Eastern shores of Lake Victoria in the morning

• The signal was weak for afternoon precipitation

Total Surface Precipitation Probabilities (at least 10mm)

ECMWF EFI and EPS

• The EFI showed no indication of a severe weather event in and around Lake Victoria

• For the 1st and 2nd six-hourly forecasts the EPS members’ prediction of total precipitation had low confidence

• The forecast for the 3rd six hours had a high confidence in which almost all the ensemble members predicted total precipitation in the region of 1mm/6hr

• In the last 6hours, 99% of the ensemble members predicted precipitation of 4mm or less

NCEP GFS Forecast for CAPE

Ncep GFS Forecast for Precipitable Water

• The CAPE values were low over the region• Precipitable water values were relatively high• This implied insufficient energy for lifting moisture

thus culminating into low convective activity over the region

Regional Guidance Products

RSMC - Nairobi RFSC – Dar-es-salaam

Day 1 and 2 Risk Tables

Forecast issued on 17th November, 2012 Valid for 17th and 18th November, 2012 Medium heavy rains expected for Eastern and western

Uganda Degree of confidence being medium ( 50 – 75% )

Real-Time Satellite Observations

Challenges

• Inadequate data• Insufficient facilities and personnel• Model output simulations• Low Public Trust