Mods take note, I had to make a quick decision on this thread, as there is already a discussion of Gonzalo that has touched on this storm potential. There are two reasons for not wanting to change that thread with a LEVEL 1 (local LEVEL 2) tag, one being fear of thread hi-jack, but also that I would prefer not to hype up the Gonzalo aspect of the storm.
This event takes the energy from post-tropical Gonzalo, currently located around 53N 30W, and merges it with an existing frontal system northwest of Scotland. The results according to most model guidance (which has upgraded somewhat overnight) will be a fast-moving, sharply defined trough that appears likely to generate wind gusts to 100 or 110 km/hr over many parts of Ireland around midnight to 0600h, but as strong as 130 km/hr near Donegal Bay and possibly into Galway Bay as well.
The timing is conducive to a moderate storm surge with some overtopping of coastal installations possible around the high tides at 0430-0500h Tuesday.
Coastal and marine interests should be aware that very poor conditions will sweep in late afternoon or early evening and rage on most of the night with the possibility of some force 11-12 conditions off the west coast.
Expect blustery conditions for about 12 hours once this sets in, with the risk of some power outages from falling trees weakened by the saturation of soils after 20-25 mm rainfalls. The winds will come from the SW until frontal passage and then from W to WNW, and in fact the strongest winds for some may occur after frontal passage. The south coast, on the other hand, will see stronger gusts ahead of the trough, then after the windshift gusts may not be quite as strong there coming from a land direction.
Watch for updates (and if the threads are merged, so be it).