Weather Related Words:
1) Flurries: very light snowfall
E.g.  There are a few flurries but the snow is not sticking to the roads.
2) Fog/Foggy: thick water vapor that blocks the vision 
E.g.  We could not see the road because there was too much fog.
3) Frost: ice crystals on a frozen surface
E.g.  Some flowers are so strong they can withstand frost.
4) Lightning: electrical discharge and flash between a cloud and the ground
E.g.  You must switch off the computers when it's lightning.
5) Overcast: no sun is visible
E.g.  The sky is overcast this morning.
6) Partly cloudy: the sky is sunny and cloudy at the same time
E.g.  Today's forecast is partly cloudy with clear skies by evening.
7) Sleet (similar to hail): rain that freezes as it falls
E.g.  all weather tires are best if you have to drive in sleet.
8)Tornado/cyclone: windstorm
E.g.  The tornado picked up everything in the path, including animals and cars.