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How much rain will Downtown L.A. receive from July 1, 2017 to June 30, 2018?


Total Rain from 7/1/2017 to 6/30/2018  

16 members have voted

  1. 1. How much rain will downtown L.A. receive from July 1, 2017 to June 30, 2018?

    • 3.21 inches or less (driest year on record)
      1
    • 3.22 to 5.00 inches
      7
    • 5.01 to 7.50 inches
      4
    • 7.51 to 10.00 inches
      2
    • 10.01 to 12.50 inches
      2
    • 12.51 to 15.00 inches
      0
    • 15.01 inches or more
      0


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It's been a terribly dry year for Southern California with only one major storm so far, and it's likely the very heavy rain may have prevented the water from soaking in well enough and giving a chance for the hills to green up. Another very weak storm is predicted tomorrow, but in a few weeks without some significant rainfall we are likely to see more high fire danger conditions.

So far the driest year on record for Downtown L.A. is 3.21 inches in 2006-2007. At that time the water year was July 1 to June 30, but recently it's been October 1 to September 30, which I think is a stupid change. However, some websites still record the values from July 1 to June 30.

Here is a poll for how much rain Downtown L.A. will get by June 30. Will this be the driest July 1 to June 30 on record?

FYI, total rainfall since July 1, 2017 as of January 18, 2018 is 1.96 inches.

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Driest year on record. We match the QBO and solar progression for 6/30/06 - 7/1/07, except this year is a Niña with enhanced off-equator SSTAs/forcing and even more expanded Hadley Cells now compared to then.

 

Disaster.

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It's been a terribly dry year for Southern California with only one major storm so far, and it's likely the very heavy rain may have prevented the water from soaking in well enough and giving a chance for the hills to green up. Another very weak storm is predicted tomorrow, but in a few weeks without some significant rainfall we are likely to see more high fire danger conditions.

 

So far the driest year on record for Downtown L.A. is 3.21 inches in 2006-2007. At that time the water year was July 1 to June 30, but recently it's been October 1 to September 30, which I think is a stupid change. However, some websites still record the values from July 1 to June 30.

 

Here is a poll for how much rain Downtown L.A. will get by June 30. Will this be the driest July 1 to June 30 on record?

 

FYI, total rainfall since July 30, 2017 as of January 18, 2018 is 1.96 inches.

 

Keep in mind that WU data contains errors. Example: Pasadena minimum of 17F on 2/21/03 :rolleyes:  [Actually: 75/ 53

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Driest year on record. We match the QBO and solar progression for 6/30/06 - 7/1/07, except this year is a Niña with enhanced off-equator SSTAs/forcing and even more expanded Hadley Cells now compared to then.

 

Disaster.

 

When do you see these features changing to something that would be more favorable for Socal rainfall?

 

I really hope these Hadley Cells contract in the future, so we aren't dominated by the Baja ridge for the rest of eternity!

 

If this pattern continues, there is going to be a huge part of the country in severe to extreme drought later this year.

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I have been forecasting Los Angeles to receive around 8" for the season, like that of 1962-63, but by the way things are going, it could be much lower. However, I am sticking to my original forecast of 8" from earlier this season, in case we get a wetter pattern later in the winter and spring, which is still a possibility.

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When do you see these features changing to something that would be more favorable for Socal rainfall?

 

I really hope these Hadley Cells contract in the future, so we aren't dominated by the Baja ridge for the rest of eternity!

 

If this pattern continues, there is going to be a huge part of the country in severe to extreme drought later this year.

Probably in 2019/20, when the next Niño starts. Next winter is debatable, but I’m leaning dry.

 

And yeah, I’m already worried about the 4-Corners/Plains death ridge. Dry springs across the Southern Plains and Central US are usually a bad omen when it comes to the subsequent summers..and we’re also in a pretty nasty drought here by cold season standards.

 

If we don’t see some good rains in April/May this year, we’re screwed. It’s already as brown/dead as I’ve ever seen in at this time of year. Almost no green grass anywhere, even dormant conifers are dropping needles and branches.

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Probably in 2019/20, when the next Niño starts. Next winter is debatable, but I’m leaning dry.

 

And yeah, I’m already worried about the 4-Corners/Plains death ridge. Dry springs across the Southern Plains and Central US are usually a bad omen when it comes to the subsequent summers..and we’re also in a pretty nasty drought here by cold season standards.

 

If we don’t see some good rains in April/May this year, we’re screwed.

 

Hopefully you are correct about 2019-20, but am also hoping 2018-19 is at least somewhat better than this year.

 

Drought in the areas you mentioned could very well bring a hot summer to those areas. I wonder if there will be an enhanced summer monsoon this year?

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  • 4 weeks later...

Starting to look like Phil may be onto something...

FWIW, the SSW probably renders my prediction irrelevant at this point. The -NAM/-NAO will force an equatorward contraction of the EPAC Hadley Cell, along w/ constructive interference from the QBO (still downwelling).

 

Then again, this process might take some time. I’m not sure how “entrenched” this NPAC regime was/is, so it might put up a fight if the subsurface is homogenous enough to maintain some degree of coupling w/ the atmosphere above.

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  • 2 weeks later...

They have 2.55" since July 1 with the 0.07" they got last September.

 

Amazing with all of the deep troughing and suppressed jet we have seen recently.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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Amazing with all of the deep troughing and suppressed jet we have seen recently.

Most of the storms of this cycle took an over land trajectory, severely limiting the moisture over Socal. The last couple of storms have brought some rain, but still underwhelming in many areas. Hopefully subsequent storms over the next couple of weeks bring more significant rain and snow to Socal. 

 

On a brighter note, the Sierras got some decent much-needed snowfall with this last system, and helped out the ski resorts tremendously and helped boost the snowpack a bit.

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  • 2 weeks later...

With 0.18" more for Downtown LA last night, they are now at 3.37" since July 1, so it will not be the driest year on record.

 

I'm shocked you guys didn't do better with the recent pattern.  Really bad luck I would say.

Death To Warm Anomalies!

 

Winter 2023-24 stats

 

Total Snowfall = 1.0"

Day with 1" or more snow depth = 1

Total Hail = 0.0

Total Ice = 0.2

Coldest Low = 13

Lows 32 or below = 45

Highs 32 or below = 3

Lows 20 or below = 3

Highs 40 or below = 9

 

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  • 4 weeks later...

As of April 14, 2018, Downtown Los Angeles is sitting at 4.68" for the season (July 1 to present) or 4.61" (October 1 to present). I prefer the old rain year (July 1 - June 30) because the change of rainfall seasons occurred at the driest part of the year climatologically statewide.

 

If Downtown L.A. doesn't receive any more rain for the remainder of the season (June 30), this would be the 3rd driest season on record, surpassed only by 2006-07 and 2001-02, and would even be drier than 1960-61, which was the driest season on record at the time.

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  • 2 weeks later...

As of May 3, Downtown L.A. is now at 4.70" for the season, which is still chasing that paltry 1960-61 total of 4.85".

 

Absolutely pathetic!

 

Meanwhile, Tucson, AZ has had 11.14" from July 1 to present, thanks to a very active July and August monsoon season. 6.80" fell in July alone! The winter has been fairly dry there, though with only 2.57" since October 1.

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  • 2 weeks later...

Flagstaff, AZ, has received only 38 inches of snow for the season (which is over for all intents and purposes).  That's the second-lowest snow year of the airport era (1983-1984 was 32 inches).

 

That is because this winter was so crappy across quite a wide region of the west except for Washington and Montana.

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Once again the "climate change" pattern seems to favor strong ridges over the West Coast all winter and persistent troughing all of the late spring when it's too late to get any major rain. If we could just switch those around, we would have enough rain and spring would be warmer than winter like all other Northern Hemisphere locations.

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Once again the "climate change" pattern seems to favor strong ridges over the West Coast all winter and persistent troughing all of the late spring when it's too late to get any major rain. If we could just switch those around, we would have enough rain and spring would be warmer than winter like all other Northern Hemisphere locations.

This is so frequently misunderstood.

 

Climate change isn’t causing the pattern. Rather, the pattern is what is carrying out the climate change, whatever its trigger may be.

 

The best analogy is El Niño. Obviously, the global temperature spike doesn’t cause the El Niño. Rather, the change in the global circulation and heat transport produces both the El Niño SSTA signature the global temperature spike.

 

What ENSO does to climate on short timescales, other modes of ocean/atmosphere circulation do on longer timescales. The only difference is time.

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  • 4 weeks later...
  • 2 weeks later...

Boy, was I off :wacko:

I never expected a La Nina year to be this dry for Socal. The driest years (or "ultra-dry" years that bring less than 7" to downtown Los Angeles) have always been either ENSO neutral or weak El Nino. There have been some 7-8" La Nina years in the past, but nothing like this year, which was very close in total to 1960-61, which was ENSO neutral.

 

I am really hoping that the SSW (Sudden Stratospheric Warming) event that took place in late February is a game-changer for future winters here in Socal, in that we start seeing more precipitation once again. We got into this horrible drought situation after the SSW event of 2013, and we have only had one really decent winter (2016-17) since the wet season of 2010-11.

 

If we continue to have dry to ultra-dry winters for the next decade and beyond, I will almost be convinced that the loss of Arctic sea ice in recent years from the warming of the Arctic is playing a big role in the weakening and displacement of the jet stream to the north, depriving the southern half of California of its needed precipitation.

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The Arctic has remained relatively stable since 2007, and it’s actually pretty healthy-looking right now, all things considered.

 

The drought was/is a result of the Pacific z-cell expansion which corresponds to the more poleward jet(s) and positive state of the northern annular mode. The warm Arctic is tied into that process as well, but it’s a result of it, rather than a cause.

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The Arctic has remained relatively stable since 2007, and it’s actually pretty healthy-looking right now, all things considered.

 

The drought was/is a result of the Pacific z-cell expansion which corresponds to the more poleward jet(s) and positive state of the northern annular mode. The warm Arctic is tied into that process as well, but it’s a result of it, rather than a cause.

 

Do you see any sign of this process reversing anytime soon, and will this SSW that occurred back in late February help establish a more normal pattern in your opinion?

 

I really don't want to see Socal continue to be nearly as dry as the Atacama Desert like it has been off and on for these last 5 years, especially years like 2012-13, 2013-14 and 2017-18.

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