Very cold air not over

Isn’t this weekend great? Highs in the 60s, golf courses, lakes, little-league baseball fields, and backyards filling up with people. I love it. And, remember, April is only 5 weeks away.

But, we are still going through what will likely be one of the top 5 coldest winters on record in BHM, with 2 measurable snow events, and very few days with highs in the 50s. The Arctic Oscillation Index (AO) has been negative throughout most of the winter, meaning above normal temperatures in the Arctic, but below normal temperatures in the midlatitudes (here, Europe, Asia). Basically, north winds at low-levels have kept the cold air moving away from the poles and toward the equator, keeping cold air from building as much in the Arctic, instead allowing it to spread across a large part of the Northern Hemisphere.

Here is a chart of the AO index for the winter so far, and the NCEP ensemble forecast for the next 2 weeks (right of the solid line).

We’re getting a brief break right now in the cold air, but more is on the way starting early next week, and continuing for most of the next week or two. Here are NCEP ensemble low-level temperature anomalies (in degrees C).

Blue areas are colder than normal, and red areas are warmer than normal.

So, get ready for at least a few more cold days and very cold nights before Spring gets here to stay for a while.

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