Thursday, December 22, 2011

Heavy rainfall in Dar es Salaam

Dar es Salaam experienced extremely heavy rainfall yesterday, with one source reporting a 24-hour total at the airport of 233 mm. An article in The Muslim News quotes a Tanzania Meteorological Agency (TMA) source reporting 156.4 mm. Either one is apparently the highest 24-hour amount since the mid 1950s.

Flooding and lightning strikes have killed at least 20 people according to the BBC, and left thousands homeless. The event has reportedly crippled the city of Dar, destroying considerable infrastructure. TMA forecasts the heavy rains to continue over the region.

Snowfall data and accounts from Kilimanjaro are not available yet. Being convective in nature, the heavy rainfall may not be widespread.
[UPDATE 12/30 & 1/3/12:  Snowfall began at the station on Wed., 28 Dec. and continued to the 31st. Telemetry indicates ~11cm of accumulation for the event, which is certainly a significant snowfall by Kilimanjaro standards. Tim from SENE was recently on the mountain, so perhaps we'll have a first-hand report soon.]

Tuesday, December 20, 2011

East African Drought

The Weather Underground blog has a helpful discussion of the drought which so terribly impacted East Africa this year, and author Jeff Masters points out that it was 2011's deadliest weather disaster. He annotates several figures from NOAA's Climate Prediction Center (above), showing that the drought was concentrated to the north of Kilimanjaro. Likewise, the most anomalous rainfall through the currently-underway short rains season has also been further north. On the mountain, the relative snowfall amounts are consistent with regional patterns depicted in the figures.

Masters also provides some thoughts on East Africa's future vulnerability. Considerable uncertainty exists between measured precipitation trends, and that predicted by models due to changes in Walker circulation. Kilimanjaro snowfall and glacier mass balance measurements support evidence from station data for steady drying of the climate in recent decades.

Fieldwork photos

Finally... images from September-October fieldwork have been processed, and a selection is now posted here! This trip was especially enjoyable and productive, as hopefully conveyed by the photos.