予想（する）

prediction, expectation (in one's own opinion)

予報（する）

forecast, prediction (as announced/reported by someone)

湿度

level of humidity

湿気

humidity, moisture

湿る

to become moist, to become damp

曇る

to get cloudy, to become overcast

曇り

cloudy

嵐

storm

強風

strong wind

大雨

heavy rain

小雨

light rain

折りたたみ

folding, collapsible (esp. umbrella)

（を）差す

to open (an umbrella)

にわか雨

rain shower

にわかに

suddenly, abruptly, something so suddenly it couldn't be predicted

突然

abrupt, sudden

とたん

just (now), as soon as

（が）濡れる

to get wet

（を）濡らす

to wet (something)

あっという間に

in the blink of an eye

（が）止む

to stop

ところどころ

here and there, some parts (of something)

（が）積もる

to pile up, to accumulate

快晴

clear weather

輝く

to shine, to glitter

眩しい

blindly bright, radiant

のち

later, afterwards

当たる

to be right, to be correct

外れる

to miss the mark, to get it wrong (guess, prediction)

ふるさと

hometown