(Blog Written by Donald Sutherland)
Some morning thoughts…
1. Yesterday, the Temple/Miller, TX automatic observation site recorded a temperature of 129°F (53.9°C). It remains to be seen whether this recording will be validated. What is more clear is that the focus of the heat has shifted to the Western Third of the U.S. and Canada.
2. Ensemble forecasts have persistently called for the development of a strongly negative PNA after mid-month. A negative PNA correlates increasingly with heat in the Central and Northern Plains and Great Lakes toward the end of July and in August. If the PNA forecast verifies and if the outcome is consistent with the correlation, this could be a signal that the relief from extreme heat in that portion of North America could be temporary.
3. For now, the GFS ensembles keep the focus of the anomalous heat in the Western Third of North America through 360 hours, including the Pacific Northwest. That outcome would be at odds with a strong PNA-.