With tomorrow's weather forecast looking cold and rainy, it looks like the sixth annual Big Walk will have to take place next Sunday, April 4th. If it rains again on that day, Wednesday the 7th will have to do (although waiting that long might mean missing the peak of the hanami season). The route will likely start at Inokashira Park in Kichijoji and finish near Nakameguro.
Until then, sacrifice a goat and pray for my meteorological fortuity.