SNOW UPDATE FROM TMT'S PETER O'DONNELL:
Snow chances will increase steadily this evening for regions in the current snow areas of Ulster and north Leinster, and then north of a line stretching from Wicklow to Clare line through Saturday as colder temperatures develop. It is very difficult to say what areas will see good accumulations other than east facing slopes or any higher terrain in the zone prescribed above.
There is nothing too organized about the pattern but it has the look of a patchwork quilt of 1-5 cm accumulations with some areas seeing only trace amounts. Mixing issues (rain to snow or snow to rain) should gradually fade out except for onshore locations and locations at sea sea level. Even here the rate of fall will determine precipitation type i.e. the harder it comes down the more likely snow or at least heavy hail.
The most important detail is that 850 mb temps (upper air temperatures at approximately 1500m) are going to fall steadily towards about -7 C in the zone I have described. This is colder than currently in snow areas of Ulster, so that should be a very good sign for phase change. It will be a cold frosty night, with icy patches likely to form. Lowest temperatures of plus 2 to -2 C, or lower where there is lying snow.
South of the zone outlined above, snow chances are restricted to higher ground mostly above 300m until we see further advance of the upper level cold through Sunday. Then it becomes a question of where oncoming Atlantic moisture hits receptive upper level parameters and that would seem to be mid-Kerry. Places like Inch, Dingle and Valentia will likely not see rain turn over to snow, but Listowel to Cork should do so at least for part of Monday.
Snow chances will increase steadily this evening for regions in the current snow areas of Ulster and north Leinster, and then north of a line stretching from Wicklow to Clare line through Saturday as colder temperatures develop. It is very difficult to say what areas will see good accumulations other than east facing slopes or any higher terrain in the zone prescribed above.
There is nothing too organized about the pattern but it has the look of a patchwork quilt of 1-5 cm accumulations with some areas seeing only trace amounts. Mixing issues (rain to snow or snow to rain) should gradually fade out except for onshore locations and locations at sea sea level. Even here the rate of fall will determine precipitation type i.e. the harder it comes down the more likely snow or at least heavy hail.
The most important detail is that 850 mb temps (upper air temperatures at approximately 1500m) are going to fall steadily towards about -7 C in the zone I have described. This is colder than currently in snow areas of Ulster, so that should be a very good sign for phase change. It will be a cold frosty night, with icy patches likely to form. Lowest temperatures of plus 2 to -2 C, or lower where there is lying snow.
South of the zone outlined above, snow chances are restricted to higher ground mostly above 300m until we see further advance of the upper level cold through Sunday. Then it becomes a question of where oncoming Atlantic moisture hits receptive upper level parameters and that would seem to be mid-Kerry. Places like Inch, Dingle and Valentia will likely not see rain turn over to snow, but Listowel to Cork should do so at least for part of Monday.
***For the record, below is a forecast map that we posted here on Thursday morning outlining the snow risk for Ireland during Friday. It corresponds with what we have seen during the day.
Please note that further details are available in here.
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