ECMWF Monthly Maps

October 12, 2015

For hardcore weather geeks only…

Hmmm, not quite what we were seeing last week at this time.  The ECMWF monthly run shows upper-level ridging quite persistent over the next 4 weeks.  Here are the 4 weekly maps:

500za_week1_bg_NA

500za_week2_bg_NA

500za_week3_bg_NA

500za_week4_bg_NA

Notice ridging wants to stay closer to us.  Here are the 15 day anomalies from the GFS, GEM’s most recent runs:

m500za_f360_bg_NA (1)

m500za_f360_bg_NA

This is a wet pattern in the last few days of October…quite a bit different.  Hmmm, disagreement is always interesting.

Chief Meteorologist Mark Nelsen


Very Warm Pacific, El Nino Update, A Normal September

October 12, 2015

Just noticed this on a morning discussion over on the WeatherBell (paid) site.  Joe D’Aleo has a graphic comparing current sea surface temps to the 2002 and 1997 El Ninos.  Right now equatorial temps are a bit cooler than 1997 but warmer than the weaker 2002 event:

Capture

The two maps on the right are current SST, the left side is 1997 on this date and 2002 (lower left).  You can see one significant difference in this year…warmer ocean temps across the northeast Pacific.  The Blob might look a bit different, but temps are still well above normal for most areas offshore and it sure hasn’t died at all.

By the way, WeatherBell charges about $180/year for this site…worth every penny (boss pays for it) in this business.  No, they don’t give me free access for tooting their horn.

El Nino is currently in the STRONG category with the weekly ONI index at 2.4 as of today.  The highest 3-month running average is 2.3, set during the 1997 event.  You can check out the values here.  There is a weekly update at this link out every Monday morning.

So now we wait and see what this event brings.  I think it’s obvious we are guaranteed a very mild winter, but two big questions:

  1.  Will it be a “wet event” like 82-83 and 97-98?  Or a “dry event” like 91-92, 02-03?  Gut feeling is that it’ll be the former.  Plenty of precip mixed in with lots of dead periods.
  2. Will we get some sort of snow/ice event?  It only takes one “backdoor arctic blast” through the Gorge and then returning moisture to give us a storm in the metro area.  So the pattern has to only be just right for less than a week to give us something memorable…like January 1998.

The national September stats are out from NCDC…and…it was a NORMAL MONTH!  Yes, we didn’t have a hot September, we didn’t have extra warm nights, we weren’t chilly.  Just slightly below average rainfall.  Otherwise a very pleasant month…that was nice:

201509 (1)

201509

I hope you enjoyed it because October is running well above normal again.  The next 16 days on the ECMWF (out to near the end of the month) show warmer than normal or normal.  Very warm later this week, then a quick cooldown over the weekend:

tseries_850t_000-360_Portland

Chief Meteorologist Mark Nelsen