A 12 Day Outlook: Is That Ridiculous?

June 27, 2016

Yesterday I first used this graphic during the 10pm show; of course this is today’s version:


It’s a 12 day OUTLOOK (not a detailed forecast).  It contains an abbreviated 7 Day forecast, then a more general outlook for the following 5 days.  I’ll use this in the 2nd half of the 10pm show and sometimes in other shows as well.  There may be some days in which I don’t use it at all, you can see the reasoning below.

In Portland all long-range TV forecasts were just 5 days until around 1996.  That year a new news director showed up at KOIN (I was there from 1993-2000) and suggested we do a 6 Day Forecast.  How clever…it was Channel 6!  Forecast accuracy was gradually improving in the models so the extension seemed reasonable and we implemented that change.  Within the next 5 years the other 3 stations went to 7 day forecasts and we did at KOIN as well.  When I came over here to Meredith Corp. as KPDX Chief Meteorologist in 2000, management was listening to some weird consultant that only wanted a 4 day forecast (what????).  I compromised and we went back to a 5 day forecast for two years.  When KPTV/KPDX merged in 2002 (new bosses!) the KPDX newscasts ended and I was back in the 7 Day forecast game via KPTV from there on out.

I know of at just two other times longer range forecasts have been used on-air here in Portland.  Sometime in the late 1980s I remember Miles Muzio at KOIN doing “The Long Ranger”; a 14 day forecast.  Wow, that was pretty bad considering the state of forecasting in the 1980s.  Yet, I clearly remember getting all wound up when he showed freezing rain possible 12-14 days away!  It didn’t happen of course.  Then here at KPTV around 2009 on Good Day Oregon our meteorologist Drew Jackson would occasionally do a 12 day forecast.  He did that when the pattern appeared stable enough or clear enough that far out to give some confidence.  That was my inspiration to bring it back.

So why bring it back?

I think it’s time for several reasons:

  1. Numerical Forecast Modeling (THE MODELS) is gradually getting better and better, and more important…
  2. …Model Ensemble forecasts are now available to us here at FOX12.  Those are collections of many different runs of each model.  When they are all similar, confidence goes up.  When very different? Low confidence!
  3. We are all seeing 10-14 day forecasts all over the place now on apps.  Even our own FOX12 Weather App goes out to 10 days!  That’s all computer driven of course; no human interaction with that forecast.  Those numbers come straight from long range models, regardless of the accuracy.  Since all that information is out there, at least I can give you some perspective on what you’re seeing.  That’s where the 12 day forecast helps out a bit.  For example, if just one model is showing snow in 9 days and your app says so, I can throw a little reality into that forecast based on what others are showing.
  4. People ask me all the time about the “big picture” beyond the 7 Day Forecast.  Examples:  Do you see a dry period coming up to stain my deck? Any chance at all for extreme heat in the next 2 weeks? Are we clear of a “snow threat” for the next 12 days?  Those questions will often be answered by a 12 day outlook.

There will be times when long range models are all over the place; I likely won’t even bother to guess on those days.

So is a 12 day forecast RIDICULOUS in 2016?  In this format I sure don’t think so!

By the way, the big thing I’m noticing in maps for the first 10-14 days of July is a total lack of extreme heat.  This summer is sure looking different than last year…a good thing.  Take a look at the 16 day temperature anomaly from the 12z GEFS ensembles:


Below normal for this coming weekend then 10 degrees or less of above normal temps through the 13th.  That means highs would be somewhere between 70-88 over the next 2 weeks.  The monthly ECMWF run came out this afternoon…very interesting.  About as normal as it gets.  Check out four weeks of surface temperature anomaly across N. America.  Near or slightly above normal through July:

Chief Meteorologist Mark Nelsen