Her response followed criticism of a full-colour map published by Met Éireann over Christmas showing orange storm warnings in place across the Republic of Ireland.
However, on the same map, six counties in Northern Ireland remained white and had no information.
In a post viewed by around 300,000 people online and liked by more than 1,000, including RTÉ’s Rachel English, one poster called the map “ridiculous”.
A commentator said: “Hello Mr. Alien, it’s a bit silly not to include the six counties that make up the North/NI when creating your map. Letting us know doesn’t ‘de-divide’ the location. , we feel that this would be a serious breach of the Good Friday Agreement. ”
another commenter asked. “Is it snowing over there?” Why is the map white? ”
Meanwhile, another commentator was unhappy about visiting relatives in Northern Ireland, saying it would have been easier to drop the “nonsense” and “show the weather across the island”.
In response, Ms Donnelly compounded her criticism over the weekend, slamming the idea that Met Éireann was “excluding” six counties from weather information.
she said this sunday independent Éireann Met Office issues weather forecasts for the entire island of Ireland, but says: “Responsibility for issuing warnings for that jurisdiction rests with the Met Office.”
She said: “Met Éireann displays warnings issued by the Met Office for Northern Ireland. The fact that the area is shown in white on the map means that there are currently no warnings in place for these counties. “This means that there was no warning that there was any warning.”
Ms Donnelly added that she “fully understands the sensitivities” surrounding the division between North Korea and the Republic of Ireland, but pointed to the “nature of the posts on Platform X” that had sparked controversy.
She stressed that Met Eireann operates in collaboration with the Met Office and that the two sides enjoy an “excellent professional working relationship”.
“It has nothing to do with partition other than that the Met Office is responsible for issuing weather warnings for Northern Ireland. Met Eirean issues warnings to the rest of the island. We issue an overall weather forecast and this map is specific to the warnings that are in effect at that particular time.”
In the past, the BBC in London has been accused of treating the Republic of Ireland like “some kind of North Korea” after refusing to include the names of major cities on its weather maps.
Critics suggested it follow the example of ITV, which regularly shows weather maps of cities across Ireland.