ECMWF Month-Long Maps: Chilly 1st Half of November?

October 28, 2013

Last night’s ECMWF monthly run.  Some interesting changes from the previous two runs.  Appears that upper-level high wants to be a little farther west, leaving some sort of troughing (cool) over us through mid-November.  That says cooler than average temps for the first half of the month.  If the trough is over or west of us, that’s also very wet.

500za_week1_bg_NA

500za_week2_bg_NA

500za_week3_bg_NA

500za_week4_bg_NA

The cool trend shows up nicely in the 12z ECMWF ensemble 850mb chart:

tseries_850t_000-360_Portland
Note the red line showing the average of all the ensembles; it’s below the average of +4 to +6 during this period.

Chief Meteorologist Mark Nelsen