The past week has not been a good one here in the Midwest. Aside from being wet, here In Cedar Rapids we've gone 5 consecutive days without highs getting out of the 40s. I can't find another year where that has happened so late in the season. Here's the temperature departures for the past week.
After the passage of this weekends monster storm, the 500 mb jet is now highly amplified and it looks like a northwest flow will prevail for the foreseeable future.
In fact, most of my long range teleconnections strongly favor below normal temperatures through at least the middle of May. Here's 3 key indicators that make this a high confidence assessment.
The AO (Arctic Oscillation) in a negative phase.
The NAO (North Atlantic Oscillation) also in a negative state.
The EPO (Easter Pacific Oscillation) negative as well.
If that's not proof enough of a cool pattern (and it sure is for me), the MJO (Madden Julian Oscillation) is getting more and more amplified and moving into Phases 1 and 2. (Follow the dotted green lines showing the daily progression). Both 1 and 2 are chilly phases for May here in the Midwest. Below you can see how phase 1 equates to below normal May temperatures over the heart of the nation.
The U.S. long range climate model the CFSv2 is also catching the trend. Here's its temperature departure forecast for the next 10 days.
Now days 10-20.
Going a step further, the model has this for temperatures the entire month of May.
If there's a silver lining to the cool weather, it's the fact the northwest flow aloft will cut off the deep moisture that's caused so much rain in recent weeks. The GFS has this for total precip the next 10 days. Not much to be found around my neck of the woods. Good news for farmers who have plenty of field work to do.
In summation, it's a good news bad news forecast for the central Midwest. The rain has gone away but the cool temperatures are here to stay. Cool is now the new rule! Roll weather...TS