For Btumbawe :
No gale warning.
The reliability of the situation is good.
Skies very cloudy, risk of some thundery outbreaks. Risk of showers in the morning, light showers dying away progressively in the afternoon. In the evening, skies progressively clouding over with storms forming.
Possibility of showers NNE force 1 turning ESE force 2 in the middle of the day then E. Gusts reaching 11 knots in the evening. Smooth to slight sea. Low, short swell from ESE. Visibility reduced by fog becoming good in the middle of the day then reduced by mist.