Maps ahead for the real hardcore weather geeks only…
Interesting turn of events with the ECMWF over the past few days. It’s now showing ridging returning earlier than expected. In the monthly run one week ago it was showing ridging after the first week or so of October. Now it’s pretty much from here on out through the month of October. Here are the 4 weekly maps showing upper-level ridging hanging around the region for the next 4 weeks.
I can’t show you the maps (legal issue), but the total precipitation (ensemble average) is only around 2″ in the next 32 days here in the valley. The control run (higher res) shows 3-4″ during that period. Surface temperatures are above normal, when all 32 days are averaged, in both control and ensembles.
What a pain to forecast this coming weekend. The GFS builds a ridge quite close to us, but the ECMWF and GEM (Canadian) both bring a cold trough down over us Saturday. It leaves quickly, but these models would imply 60-65 degrees on Saturday with a few showers, whereas the GFS says about 85 and sunny with strong easterly wind. I went in the middle for now. You can sure see the disagreement even among just the ECMWF ensembles:
Chief Meteorologist Mark Nelsen