A strong low pressure system will arrive on Shabbat and last into Monday. Rain associated with this system will overspread the western coastal areas sometime Saturday morning and arrive in the mid to late afternoon in the central mountains and eastern Valleys.
This looks to be a fairly widespread rain event, and it will be cold enough for accumulating snow on the Hermon.
There will be some very strong convective cells just off-shore, so there is the potential that the coastal cities will get brushed with heavy rain (we'll try to look into this more on Erev Shabbat).
Rain Motzei Shabbat/Saturday night (> 10 mm/3-hr) will bring the potential for flooding in the eastern Valleys, as well as areas of the Arava and possibly even down to Eilat.
The weather has been cool in the mornings (about 5 Celsius here in Efrat) and we don't see a warm up in sight. In fact, the end of next week or early next week may see a more significant winter storm, both in terms of cold and rain amounts. One global ensemble member is also indicating very strong winds.
We'll see how that goes, but first this "weekend's" rains.