Confidence increased, details in post

The chances of a severe wx outbreak affecting the CONUS has been raised to 25%, give or take. The GFS and its ensembles are really latching onto this idea of a strong Pacific jet stream carving out a trough over the intermountain west. A LOT can still go wrong, and these are still thoughts, not a true forecast.

Just wanted to add something regarding overall teleconnection patterns, although I'm really not good at them though. First of all, the SST's over near Japan are above normal. The temperature gradient between the Bering Sea and the central north Pacific is greater than usual (negative sea sfc temp anomalies over the Bering Sea and positive over areas further south). Negative anomalies are still strong over the Gulf of Alaska. These signs suggest that a stronger Pacific jet stream is favored. In addition, my current research indicates big but brief spurts of tornado activity are favored as an El Nino weakens. Otherwise an El Nino favors a quiet tornado season. As this current el nino weakens, this outbreak goes along with Nino climo.

As of right now, my preliminary call is for an event from Feb. 17-24. Many big events have happened on the 21st before, but that is just pure coincidence. Could this be a repeat?

SSTA's:




12Z operational GFS (BTW, it's extremely dumb to use post 300-hr GFS unless the pattern and the ensembles support what it shows. This is mainly just for future verification.)


I am in the process of attaching the ensembles.

EDIT 2-14-07: For those who read this blog (how many?), I apologize for not attaching the ensembles. I've had it on my hard disk, so here it is:
Click to animate


One last thing - I feel a SLGT risk could still verify for the Day 4-5 event, but again, the arctic high to the north is not a recipe for a major outbreak.