precipitation deficit
New York Todayから。見出しもいいけど（Let it snowのもじり）、Remember以下もさらにtellingです。
Let it rain
Good Wednesday morning. Remember that thing called an umbrella?
It’s going to pour later this afternoon. We’re very sorry.
But the earth, at least, could use some rain.
It’s been a dry month so far, with rainfall way below normal.
We’re in no danger of drought, thanks to an unusually wet winter.
(Hint: snow counts as water.)
But today’s rain could begin to make up for March’s precipitation deficit.
precipitation deficitのことを日本では「水不足」というと思いますが、正確には「降水（量）不足」ですね。（UG）
