Signs of Wetter Pattern Ahead

January 10, 2016

11pm Sunday…

January has sure been different than December.  Only .80″ rain in the past two weeks here in Portland but 6 times that much in the previous 2 weeks!

MarkRain_JanuaryFacts

Now models are looking significantly wetter over the next 10+ days.    The general pattern is a strong upper-level trough to our west over the Gulf of Alaska and weak ridging over the Intermountain region. The 10 day ensemble average 500mb maps show the lower than normal heights on both the GFS and ECMWF models:

It’s a bit farther south than in a typical winter (Thank you El Nino?), so California will continue to get rain and mountain snow out of these systems.  The GFS seems to be the wettest model.  15 day rain forecast shows 15-20″ precip in the Siskiyous and Coastal Ranges of northern California.  That’s TOO much:

gfs_tprecip_nw_65

The latest ECMWF shows up around 10-15″ in the same area.  Wow.

15 day snowfall forecast:

gfs_6hr_snow_acc_nw_41

That’s excellent news for water-starved California.   And after a 2-3 week lull in the Pacific Northwest we’ll see snow return to the Cascades too.  Just in time because we’ve come down to right around average snowpack for this time of year around Mt. Hood.

Systems appear to still be splitting a bit; so as of now I don’t see a real stormy pattern for us here in Oregon/Washington.  Just frequent wet systems.

Tired of the East Wind?

It’s been blowing almost constantly over the past two weeks.  Good news, it’s going dead for at least a day or two this week.  Wednesday’s system includes low pressure sliding by to our north and the pressure gradient actually turning WESTERLY through the Gorge.  Nice…those of you in the Gorge can enjoy the after two more days of wind Monday/Tuesday.

Chief Meteorologist Mark Nelsen