We have grandchildren visiting this week, so it seems prudent to get the new open thread started a day early, and before they wake up!

The ARCUS Sea Ice Prediction Network July report has recently been published. Here’s the graphic overview of the 30 predictions for September sea ice monthly average extent:

The July median forecasted value for pan-Arctic September sea-ice extent is 4.66 million square kilometers with interquartile values of 4.51 and 4.87 million square kilometers, while individual forecasts range from 3.12 and 5.30 million square kilometers. We note the lowest forecast is an outlier, and the only forecast that predicts a new record September sea-ice extent value (current record is September 2012, with a sea-ice extent of 3.57 million square kilometers).

Compared to the June SIO forecasts, the July median forecast is slightly higher (4.66 million square kilometers vs 4.54 million square kilometers), and the interquartile range is narrower (0.36 million square kilometers compared to 0.56 million square kilometers ), illustrating a lower inter-model uncertainty in the forecasts.

What do you suppose the odds are of the “outlier” prediction of 3.12 million km² becoming reality? How about the next lowest “dynamic model” prediction of 3.89 million km² ?

Watch this space!