Calamity John

Now it's beginning to look quite alarming. Instead of John staying west of Baja, the current forecasts show John moving into the Gulf of California, the Sea of Cortez, and moving directly into Arizona via the route Nora took several years ago. There are heavy precipitation hits forecast all over Arizona, with a particularly colorful bullseye in the Prescott area.

And soon too! The calamity is forecast to start Monday morning and extend at least through Wednesday.

But before freaking out too soon, the GFS model disagrees with NOGAPS model, and instead keeps John west of Baja, with only a mild breakup forecast.

In general, I trust the NOGAPS model better, because it is a baroclinic model (takes into account temperature gradients), whereas the GFS model is a barotropic model.

I'm going with the alarmist forecast.