In a post on X the weather agency said: "A heavy spell of rain will sweep across the country on Wednesday morning, with some hill snow in the north.
Turning brighter with sunny spells and scattered heavy showers throughout the afternoon, heavy in the west and wintry over hills in the north.
Ms Nasir said the rain could also bring "the risk of thunder" as the band moves through the afternoon and into the evening.
She said an area of low pressure will track across the country towards the east through the day "taking with it some showery bursts of rain".
Referring to the rain this morning, she said "some heavier pulses can't be ruled out" across much of the country.
