For much of the winter the MJO (Madden Julien Oscillation), a long range forecast index based on convective trends in the tropical Pacific remained in phases that were not conducive for cold air outbreaks. As a result, we enjoyed a very mild winter here in the Midwest.
Now that we are already for the warm days of spring, the MJO is not cooperating. The past week with our snow and record to near record cold we've been in the chill of phase 1. Below you can see the MJO index (dotted green line) is projected to depart phase 1 where we are today, zip through 2, and head into an extended stay in 3 to close out the month.
That's not great news as you can readily see below how phase 3 is a strong indicator of below normal temperatures for much of the nation during April. Phase 2 isn't great either. Here's the temperature analogs for phases 1, 2, and 3 in April.
At face value the MJO in 3 really looks ugly. However, there's two other teleconnections that argue against it, Here's the AO (Arctic Oscillation). For much of the past 4 months this has been in a positive phase which tends to block cold air intrusions with zonal flow aloft. We were indeed mild.
The EPO brings cold in the negative phase by promoting a ridge off the west coast and downstream trough in the central and east. Much of winter it remained positive and we were mild with modified Pacific air masses
So we have a big contradiction between the MJO (chilly) and the AO and EPO pointing (mild).
Personally I think the MJO is going to lead the way and I like the colder trend the GFS ensemble shows. In fact, if the AO and EPO were negative I'd be all in for a very chilly period ahead. However, with them not on board in their respective cold phases I will say below to slightly below normal instead of much below! Here are the temperature departures the GEFS shows in 5 day increments. That's pretty close to what the MJO temperature analogs look like for phases 2 and 3 above.
However this plays out, the short term brings cooler weather Tuesday following the passage of a cold front last night. Highs in most areas today hold in the range of 50-55 degrees....there will certainly be a nip in the air along with a fresh morning breeze.
Wednesday, ahead of the next cool-down late week we should see a rapid rise on temperatures and highs should reach 70 and hold in the upper 60s Thursday.
The next opportunity for rain will come late Wednesday afternoon and evening with the best chances in the NE half of my area. Where it does rain amounts are generally shown to be 1/4" or less...a bit heavier from NE Iowa into NC Illinois.
That's where I'm going to leave it for now. The movers are coming tomorrow and we're getting things ioaded nto the pods we have in our driveway. The contents head for Maine this weekend. We won't depart until May 1st. By the way. the process of moving sucks, if I haven't mentioned that recently. It better be worth it! We will be documenting our move to New England in the midst if the pandemic so look for blogs and videos on that in coming days. Roll weather...TS