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:


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:

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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:


Chief Meteorologist Mark Nelsen

Warm Temps Today

October 9, 2015

11pm Friday…

With the cloud cover we still hit 71 degrees in Portland today, a good 4 degrees above normal.  But take a look at the “hot” October temperatures to the south!


I was surprised Medford wasn’t a record…I see it was 94 on this date in the past though.

So far Portland is running about 5 degrees above normal for October and that sure won’t change a lot in the next week as high pressure and a warm atmosphere continue overhead most of the time.  In fact models in general remain warm for another 10 days.  WAY out there around the 20th there are indications we turn significantly cooler with more precipitation.  Climatologically the last 10 days of October we see a significant uptick in rainfall so we’ll see how that works out.  Note the good agreement on GFS ensembles with cooling to around normal (cool in late October!) around the 20th:


Note the unusually high 850mb temps about a week from now.  The ECMWF is showing the same thing, so I’m confident we may once again get up to around 80 degrees at that time.  Take a look at both the GFS (latest 00z run) and ECMWF meteograms.  Both are similar with highs peaking around 80.



I think the big message here is that this coming week may very well be the last of the warm and dry weather if long-range models are correct.  You gardeners better get your last-minute stuff wrapped up in the next 7-10 days.

It’s time for a Mark Nelsen temperature forecast check. I just charted all of September and the first few days of October.  Looks like I actually had a slight cool bias forecasting highs as PDX (just like I did all summer long), but was on the warm side more frequently with the lows.  That cooler period with clear skies back at mid-month really threw me off.



Chief Meteorologist Mark Nelsen

Fresh Podcast Posted

October 7, 2015

The boys are back! After a long hiatus, Mark and Brian return to the podcast with a recap on this crazy weather year. Last winter was one of the worst on record, this summer was the hottest on record… so what does that mean for the next few months? The guys will have an answer.

Plus, space news, Cities of the Week and Joe Raineri makes a special appearance with some big news of his own.

80s Again In October…Whew!

October 5, 2015

We hit 85 in Portland today, and check out the low 80s on the North Coast!


BMAC October 80 degree days

Very unusual to hit 85 in October.  We’ve only been that warm 3 times in the past 24 years in October.  2 of those were last year.  It’s interesting to note it was one year ago today we hit 85 as well…in fact there were 5 consecutive days 80+ last year in early October.  After that we didn’t get above 75 degrees.  Within 2 weeks we were well into the heating season with high temps in the 50s and a few 60s.  Things can (and usually do) change quickly in mid-late October!  So those of you that are tired of sunshine and crisp fall mornings hang on…those cloudy/damp days aren’t far away now.

Chief Meteorologist Mark Nelsen

October Begins Mainly Warm & Dry

October 2, 2015

9pm Friday…

This month has the distinction of being the fastest-changing of any month here in Portland.  That’s temperature-wise.  The high temp drops 12 degrees from 70 on the first to 58 on Halloween.  No other month sees such a rapid rise or fall.  It’s not really part of our rainy season although in some years the rainy season really kicks in the 2nd part of the month.


September was a somewhat boring weather month this year.  Temperatures were near or just slightly below normal and rain was below normal.

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We’re seeing a few sprinkles or showers moving through the area this evening as a cold upper level trough drops south through the Pacific Northwest.  The center of the low is just coming across the border into Washington at this hour.  It’s moving quickly and by sunset tomorrow it’ll already be into Nevada.  The result is a quick breakout to sunshine Saturday west of the Cascades as drier northeasterly flow moves in.  We have a beautiful weekend on the way!

The weather pattern for this first week or so of October appears to be very mild with upper-level ridging remaining near the West Coast most of the next 10 days.  Note the ECMWF ensemble 850mb temperature chart shows above average temperatures through the 17th.


Chief Meteorologist Mark Nelsen