snowing heavily
雱 centers on heavy snowfall: snow falling thickly and abundantly.
雱 combines 雨 (rain) with 方, which likely contributes the sound. The character is used specifically for heavy snow.
Rain 雨 pours down in a square 方 pattern, blanketing everything in thick, heavy snow.
For ホウ, imagine a heavy snowstorm howling outside: howl -> ホウ, and the snow piles up deep.