Quantcast

Not Again? Could This Trend Be More Realistic?

Good morning bloggers,

4

It’s Friday! That is the good news.  What is the bad news?  The trend in the models is the bad news.  The trend may have been there longer than we think; maybe for the past 90 days.  Take a look at the past 30  and 90 days from the Climate Prediction Centers latest ENSO (El Niño Southern Oscillation) report:

The Past 30 days:

Screen Shot 2017-12-15 at 6.17.30 AM

The Past 90 Days:

Screen Shot 2017-12-15 at 6.18.01 AM

These four maps show the past 30 days, top maps, and the past 90 days, bottom maps.  Since this years cycling pattern set up in October it has been warmer than average in most areas of the United States and drier than average in many areas as well.  Today is day 54 of the dry spell in Kansas City with only 0.27″ of rain since October 22nd.  There has been no snow yet; and there is a big concern that these trends will continue.  What is causing this? La Niña?

Screen Shot 2017-12-15 at 6.24.59 AM

Screen Shot 2017-12-15 at 6.16.56 AM

Look at the last number posted on this chart.  It is -0.7°C on the latest three-month average of this ONI index.  This is the same level this index was at this point last fall.  The patterns are very different, however.  The blue shaded areas show the La Niña events. The red shaded areas show the El Niño events. It takes five consecutive three-month averages to be considered a La Niña or an El Niño.  This winter will likely come in as a weak La Niña event just like last winter. Last winter, California was excessively wet with record breaking mountains snowfall and flooding rains.  This year has been almost the exact opposite. Something bigger is going on.  Now, look at these trends:

Screen Shot 2017-12-15 at 6.15.09 AM

Screen Shot 2017-12-15 at 6.15.49 AM

The NAO and the AO (North Atlantic Oscillation and the Arctic Oscillation) indexes have both trended into positive territory. When these indexes are positive, there is a lower probability of Arctic blasts and the flow aloft, the jet stream is more likely weakened and farther north.  Both the AO and NAO never dipped deep negative as was projected weeks ago. And, they have been trending into positive territory in the past couple of weeks.

These influences are real and affecting the weather pattern.  Take a look at last nights European Model forecast valid in ten days on Christmas Eve:

Screen Shot 2017-12-15 at 6.31.46 AM

This is the surface forecast valid December 24th at 6 PM central time. This would be another dry weather pattern; this is basically showing a continuation of what we have been experiencing.  This is very different from what the European Model and other models had been showing and modeling for the past week. The models appeared to be forming a big ridge over the eastern Pacific and a western trough, not this.

The 06z (midnight) GFS model run:

1

The trend on the other models has also been in the dry direction for Kansas City.  This map above shows an amplification of the pattern, but that eastern Pacific ridge is back and in a bad place if you want rain in Southern California, snow in Kansas City, snow in Denver.  It is back into the position that it was in over the past ten days.  This may be very wrong, and I hope so as take a look at what this model run, and the European model was similar, over the next 15 days:

2

As you can see, California stays dry and only this weekends storm produced anything near KC, which is also still suspect. Can this trend change? Sure it can. In yesterdays video, I showed one critical area to watch over the Pacific Ocean. By Sunday, this pattern will have gone through that important area where the models have been making all kinds of errors. And, then by early next week we will likely know if the dry trend continues, or if that ridge may form a bit farther west.

What does all of this mean?  For KC it means that our weather frustrations may continue to grow stronger, if that is possible.  And, it means, that a record breaking early season dry trend over Southern California where the fires continue to rage may very well continue.

Have a great day and thank you for spending a few minutes of your day reading the Action Weather Blog featuring Weather2020 and the LRC.  Let’s continue our discussion over on the Weath

Gary

Share and Enjoy:
  • Print
  • Digg
  • StumbleUpon
  • del.icio.us
  • Facebook
  • Yahoo! Buzz
  • Twitter
  • Google Bookmarks

1 comment to Not Again? Could This Trend Be More Realistic?

  • Terri

    Does that mean it might be both warm *AND* dry? Isn’t that unusual? I know that an overcast tends to keep the heat in!