During the market weather video earlier this week, I mentioned that in the 10-day forecast time frame, our lean in the outlook was in favor of how the U.S. model was showing the upper-air pattern. The comment went on to say that the European forecast model had consistently over-forecast hot conditions for the Midwest in the ten-day period, which had failed to materialize.

That comment led to a question sent in by DTN contributing editor Philip Shaw from Dresden, Ontario. Philip's question was as follows:

"...you talked about the differences in forecast between the EU and US weather models and how the differences have been consistent throughout this growing season. Why is this? Is it simply a difference of opinion between forecasters or are they interpreting data differently, as in a different diagnostic approach, or is it just "one of those things"?

Good question, and Mike Palmerino and I spent some time discussion this situation. Here's what's going on:

The European model has undergone some major tweaking in the past year, with higher resolution in its forecasts; however, the upgrades in the Euro model are not in effect past the 7-day time frame. And, coincidentally, it is during the 8-9-10 day time frame when we have noticed the Euro model's calculations wanting to bring in hot high pressure to the Midwest. Again, this feature has simply not verified.

This is similar to a situation that the U.S. model had about 10 years ago, when in its 10-day time frame the U.S. model would consistently blow up high pressure out of the southwestern U.S. clear across the Midwest, and displayed withering heat waves that did not develop. In the subsequent years, the U.S. model has had some improvements and changes made to its programming to where that model is doing a much better job--and at this point, it's handling the current weather pattern much better than the Euro is.

That having been said, we still look at both models each day, because it is important to know what they're saying about the forecast--and if they both agree for a period of time, it really boosts the confidence level of the forecast.

Bryce

I can be found on Twitter at bryceadtnwx.