Impressive high pressures sliding down out of the Arctic at the same time a busy El Nino central US track into the Lakes is producing some outstanding pressure differences and strong winds, particularly east-northeast. As the photographer says: he usually sees this kind of action more in the fall. This weather pattern is one of the main reasons the past month temperatures have averaged below normal.…/…/'s NOT over, take a look at the pressure/isobaric pattern on the first map for May 1st!

I was looking for a notable cool period this spring but thought I was wrong due to the warm March. I couldn't see how all the cold air stored in the northern and central Canadian territories and Eastern Canada would not slide down into the Lakes sometime this spring. The reason I thought I was wrong besides the warmer march was even though there was widespread north of the Great Lakes, it doesn't necessary mean it HAS to come down HERE! The jet stream pattern could have just as easily delivered it out West, northern Atlantic or even Europe. The one BIG clue it was going to come down HERE was the persistent, stubborn cold upper low over eastern Canada that was accurately predicted to give our warm El Nino problems later in the winter in my Winter Outlook into early spring noted in temperatures and snowfalls above normal, which is why late winter into mid spring has had a more winter-like tumultuous pattern when the cold air did in fact come down when the jet shifted back to a more typical March pattern later in March and most parts of April.

So what about May?

Don't put in those cold and frost/freeze sensitive plants outdoors yet as this general pattern continues into at least the first week of May. The GFS models strongly intimates a couple of surges of cold air, possibly into record cold territory, which will bring some more lows well down into the 30s (if not some 20s) across Southeast Lower Michigan focused around Thursday and again over the Mother's Day weekend (second & third map).

Even a far out as mid May; the GFS in la la land (last map) still cranks in another cold air mass on the 15th. Of course, its accuracy gets more questionable as we move out in time on the maps. In any event, through mid May keep the cold sensitive plants out of the ground in my advice. Seeds, which take a week or so to come up might be a better risk by mid May.