Really wet morning, it's been raining steadily for the past few hours. 1.41" of rain on the month so far as of this morning and probably a decent bit more today.
They’re correct that the NE-Pacific blobs are associated with +NAO, because +NAO constructively interferes with the leading EOF of +TNH (loading pattern).
We moved into a more +NAO intradecadal regime in 2013, which coincided with the termination of the -PMM/-TNH era (which had started in 2006/07 and lasted until 2011/12).
In recent years the +NAO regime has attenuated into a more neutral state, hence the reduced frequency of +TNH and slow decay of the NE-Pacific warm blob thru the 2020s. Though I suspect the “blob” will return when the IPWP extends again (sooner rather than later) unless the teleconnection between WPAC forcing and +NAO/+TNH can be broken or disrupted somehow.
With the MJO active and seasons changing, I find it hard to believe this regime of western troughing will be as stable as modeled.
There should be at least 7-10 days with a western ridge and eastern trough next month, most likely between the 10th and the 20th. Maybe I’m wishcasting but I don’t see why the current pattern wouldn’t change when the MJO returns to the W-Hem 10-15 days from now.