Negative NAO Set To Present Mid-Month Headaches…

In case you missed it, you can find our April Outlook here. We want to ensure we’re very transparent and never shy away from the products we put out there. With that said, as difficult as it can be at times, it’s critically important that adjustments are made when necessary. The fact of the matter is that medium and long range modeling has had a glaring error since late winter and early spring. First, it was the EPO and now the NAO that appear to create all sorts of chaos in the medium to longer range period.

We note the NAO (or North Atlantic Oscillation) is set to drop to as negative of levels since January and some data would suggest we’re going to go even lower.

A negative NAO in April would “normally” lead to this kind of temperature pattern:

The normally reliable European model had this kind of pattern for mid-April only a couple of days ago:

Today, we’re talking about this kind of pattern for the exact same time period:

That’s a “night and day” difference. The reason? The model is beginning to catch on to the significant negative NAO developing. Accordingly, latest data delivers incredible high latitude blocking and subsequent cooler anomalies across a large portion of the Lower 48 for the mid-month period. (Note how close the below temperature pattern in the Day 10-15 time frame is to the analog a few images above. Remarkable stuff).

This time of year won’t result in sustained colder than normal conditions and transient warmth will make itself felt from time to time, but it’s a far cry from the sustained warmth originally expected for mid-April.

As we reflect back to the struggles long range models had with the negative EPO and now flip the page forward to the negative NAO problems, it certainly leads to lower than normal confidence in long range data and leads to a “cause for pause” as we put together monthly/ seasonal data into the upcoming late spring and summer months. Transitional seasons (spring and fall) can always be fickle, but some of the issues with the drivers this spring are in a different league.

Enjoy the “spring fling” that will develop late this week and weekend. The warmest air of the year is still on deck.

Longer term, well sometimes you have to throw ideas that have been made of long hours and hard work in the trash and start over from scratch…

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