Rainwatch

Rainwatch is a prototype geographic information system developed by the NOAA Cooperative Institute for Mesoscale Meteorological Studies at The University of Oklahoma. It has been operating and gathering data since 2009 for the West African nation of Niger, and an upgraded version this year is covering the neighboring countries of Senegal and Mali — all with a combined population of almost 50 million.

Rainwatch Network Stations for Niger
Rainwatch Network Stations for Niger

The program has been featured in several publications including Nature Climate Change and the Bulletin of the American Meteorological Society.

Rainwatch provides monsoon rainfall data in real time from monitoring stations and tracks the key seasonal attributes important for food production. Knowing when, where and what to grow or graze animals can be the difference between a bumper harvest and facing starvation. This information is crucial because sub-Saharan Africa depends more strongly and directly on rainfall than any other region on Earth. Yet the area has the fewest rainfall monitoring stations and often suffers from significant delays between the time measurements are made and the resulting data and information are available for users.

“Rainwatch provides decision makers with a low-cost early warning system,” said Peter J. Lamb, director of CIMMS. “This information could be a key to helping communities prepare for and adapt to immediate weather conditions and longer term climate changes.”

Rainwatch provides information in real-time, which helped the Niger government predict and react to the drought of 2011 and deluges of 2012, and inform non-governmental organizations like Oxfam and western governments as they request international relief aid.

Monitoring of 2013 Sahel Rainy Season

THE PRESENT UPDATE IS STATEMENT NO. 8 AND RUNS THROUGH OCTOBER 31. IT IS THE LAST STATEMENT FOR 2013.

WE BEGIN BY SUMMARIZING THE OVERALL SITUATION FOR NIGER-MALI-SENEGAL AT THE END OF THE 2013 RAINY SEASON. THIS WAS ANADEQUATE-TO-ABUNDANT RAINY SEASON FOR MOST OF THE WEST AFRICAN SAHEL. CUMULATIVE SEASONAL TOTALS WERE >70THPERCENTILE AT 17 OF THE 35 STATIONS BEING MONITORED, AND BETWEEN THE 50TH AND 65TH PERCENTILES FOR 7 OTHER STATIONS. RAINFALL ABUNDANCE (>90TH PERCENTILE) CHARACTERIZED 5 OF THE 6 NORTHERNMOST MALI-NIGER STATIONS.  HOWEVER, SEVERE RAINFALL DEFICIENCIES (FROM <10TH TO 35TH PERCENTILES) AFFECTED 2 STATIONS IN EACH OF CENTRAL MALI, SOUTHWESTERN NIGER, AND SOUTH-CENTRAL SENEGAL. THIS SITUATION SHOULD HELP ALLEVIATE THE ONGOING THREAT OF FOOD SHORTAGES FOR ALMOST 20 MILLION SAHELIANS THAT PREVAILED AT THE START OF THE 2013 MONSOON, SUBJECT TO POSSIBLE IMPAIRMENT BY FLOODING IN SOME AREAS OF NIGER AND MALI AND A DELAYED RAINFALL PEAK IN EASTERN SENEGAL.

Rainfall was very low-to-minimal during October, as usually is the case. It did not change the monsoon situation that prevailed at the end of September, which was summarized in our previous report. October updates are provided in three attachments — one for each of Niger, Mali, and Senegal. A summary of that information follows:

Niger —  Very little-to-no rain occurred across southern Niger during October, continuing the prevailing situation of  September 16-30, after an excellent earlier core rainy season for most of the country. As a result, the end-of-October cumulative percentiles for 8 of the 10 stations were unaltered from September 30, with only slight changes occurring for Zinder (5 percentile increase) and N’Guigmi (5 percentile decrease). The four easternmost stations remained in the 65th-75th percentile range, and the adjacent stations of Maradi (agricultural) and Belbeji (more northern, pastoral) sustained their cumulative ranks at the 55th and >90th percentiles, respectively. Further west, there was no relief for the drought afflicted stations of Birni N’Konni and Gaya, which both remained at the 20th percentile, and the cumulative rankings for Niamey (45th percentile) and Tillaberi (>90th percentile) also were unchanged. The most outstanding seasonal results were the very abundant rainfall at the two northernmost stations (Tillaberi, Belbeji; both >90th percentile) and the substantially above average rainfall (65th-75th percentile) at the four eastern stations.

Mali  Rainfall also was minimal across most of southern Mali during October, continuing the prevailing situation of September 16-30, after an excellent core rainy season for almost all of the country. As a result, the end-of-October cumulative percentiles for 10 of the 12 stations were unchanged or varied by only +5 percentiles from September 30. Significant rainfall increased the percentiles for the other two stations — Bamako (from 10th to 45th) and Nara (55th to 70th). The most outstanding seasonal result  was the moisture abundance across most of Mali, with the cumulative rainfall for 5 stations (in the north and west) reaching the 85th percentile or greater, and that for 3 other stations being in the 65th-75th percentile range. Unfortunately, a pronounced exception to this monsoon excellence occurred at the drought afflicted east-central stations of Segou (30thpercentile) and especially  Koutiala (<10th percentile). However, the aforementioned significant October rain at Bamako lifted the capital city from the 10th to the 45th percentile, and thus out of the severe drought category for the season as a whole, but that rain likely was too late to have agricultural benefits.

Senegal   Rainfall also was minimal across most of Senegal during October. This situation maintained the same cumulative total percentiles that had prevailed on September 30 for 5 of the 13 stations being monitored, and limited the change at 7 other stations to only +5 percentiles. The only notable percentile change during October occurred at Kedougou in the extreme southeast ( increased from 20th to 50th percentile). The resulting end-of-season geographical moisture pattern is unchanged from September 30, and features greatest wetness for the 3 westernmost stations (75th-85th percentiles), moderate drought at 2 west-central stations (Diourbel, Nioro;  both 35thpercentiles) and very severe drought at the south-central station of Kolda (10th percentile), and cumulative totals that rank between the 45th-70th percentiles for the remaining 7 stations in the eastern half of the country. For Senegal, the seasonal cumulative rainfall in the capital city (Dakar, 75th percentile) ranked substantially higher than for the capital cities of Mali and Niger, which both ended October at the 45th percentile.

We hope you find the above information and its supporting attachments to be helpful. As we noted at the outset, this is the final Rainwatch statement for 2013. In 2014, we expect that our monitoring of Sahel rainfall will include several additional nations. Please feel free to contact us if you have questions or require further information.

Sincerely,

Peter Lamb, Aondover Tarhule, and Issa Lélé (The University of Oklahoma, USA)

Rosalind Cornforth and Emily Boyd (The University of Reading, UK)

African River high
African River low



Drought and flooding in West Africa is now being tracked by Rainwatch, a program developed by CIMMS researchers.