El Niño Circulation Reanalysis; September Summary; Worldwide AQI

El Niño Circulation Reanalysis; September Summary; Worldwide AQI

 

Here's a reanalysis of the 500 mb heights, height anomalies and the precipitable water anomalies for the strong and very strong El Niño winters (Nov-Mar). See http://ggweather.com/enso/reanalysis/ These really brought back my recollections from 1997-98 of the nearly continuous zonal flow across the Pacific, and the models being consistently too slow with the embedded short-waves.

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Not surprisingly, September was warmer than normal statewide while precipitation ranged from negligible to epic (Los Angeles, 996% of normal). But the Southern California rainfall must be kept in perspective as normal in LA for September is on 0.24". See  http://ggweather.com/calif/sep2015.htm 

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Interesting website with near-real-time Air Quality Index (AQI) values color-coded world-wide.  http://aqicn.org/here/ 


Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com 

 

 

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Recent El Niño Background Articles/Papers

Current El Niño Background Resources

 

A number of excellent and timely articles/papers about El Niño have been posted in the past few weeks, and I have collected some of them below. There is lots of other great stuff out there so please drop me a note if there is something I have missed.

IRI - September Climate Briefing: More Confidence than Ever


NOAA - United States El Niño Impacts


NCAR - Watch 2015 and 1997 El Niños Build, Side-by-Side


NOAA Climate Office - What can drought-stricken California expect from the El Niño winter forecast?,

NOAA Climate Office - California Drought Assessment

Commentaries about the"blob"
Cliff Mass (UWash) - Godzilla El Nino Versus The BLOB: Who Will Win?

Weather West -  Record-strength El Niño likely to bring wet winter to California in midst of worst drought on record 


Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com






 

 

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Butte and Valley Fire Weather Links

Fire Weather Links

 

In response to numerous requests for weather information in regards to the Valley and Butte Fires, here are some fire weather resources:

Fire Weather Forecasts:  NWS Sacramento Fire Wx Forecasts  (Valley Fire CAZ507, Butte Fire CAZ267 & CAZ220)

Current observations:  http://www.wrh.noaa.gov/map/?obs=true&wfo=sto 

Other Fire Weather Links:  http://ggweather.com/firewx.htm 

Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com






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Warm August Caps Warm Summer Over Most of California - Lots of SF Records

Warm August Caps Warm Summer Over Most of California - Lots of SF Records

 

Most major cities across California had warmer than normal maximum and minimum temperatures both for August and for entire summer (i.e., June, July, August). 

August saw average monthly maxima ranging from rigth at normal  at Fresno to 3.7 above normal at San Franciso and 4.2 above normal at San Diego. Only San Jose was cooler than normal with a  -0.2 degree anomaly.  The average monthly minima had even warmer anomalies.  San Francisco's average monthly minimum was 5.1 degrees above normal, with the 60.2 degrees smashing the previous record of 58.2 set just last year. Elsewhere average monthly minima were  1.4 (Fresno) to 3.7 (Los Angeles) degrees above normal.  See http://ggweather.com/calif/aug2015.htm 

Summer (JJA) was also almost universally warmer than normal, again with San Jose being the outlier. Redding was the warmest with a summertime maximum anomaly of 4.2 degrees above normal, followed by San Diego at 3.0 above normal.   Redding and San Francisco had the warmest June-July-August average minimum anomalies with +4.8 and +3.7 degrees respectively.  http://ggweather.com/calif/summer2015.htm 

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San Francisco's warm August saw 16 new daily records.  A new record max of 90 degrees was set on August 16th. But it was the 15 new or tied record high minimums that were pretty eye-catching. See the just updated SF Daily Almanac at http://ggweather.com/sf/almanac.html#August  for details.

Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com




 

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Don't Blame It On El Niño

Don't Blame It On El Niño

 

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I took this picture of humpback whales lunge feeding Monday near Moss Landing, CA. But it's NOT because of El Niño!

Though given the number of media linkages of El Niño to just about every marine animal story along the California coast the mythology has taken on a life of it's own.  There continues to be the misconception that because El Niño has something to do with warmer than normal somewhere in the Pacific AND waters along the California coast are warmer than normal THEN they are related.  They are not!

The current warm water anomalies along the California coast first showed up in February 2014 but the tropical Pacific (i.e., Niño 3.4 region) did not reach minimal El Niño strength until November 2014. 

[link to animated GIF of above image]

And this is not unique to this El Niño. Historical SST records of northern and central California SST anomalies show that during the five strong and very strong  El Niño events (1957-58, 1965-66, 1972-73, 1982-83, 1997-98) only two were warmer than normal.  And along the southern California coast, three of the five were about normal.

Jan Null, CCM
Golden Gate Weather Services

 

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Updated El Niño Forecast Models Get Even Stronger

Updated Niño Models Get Even Stronger

 

The updated forecast models for El Niño Sea Surface Temperature Anomalies (SSTA) from IRI/CPC have gotten even stronger.  Last month's average of the 17 dynamic models had the Oceanic Niño Index (ONI) peaking at 2.2 in the October/November/December (OND) period and now they are forecast to peak at 2.5 in OND and stay there through NDJ. If these numbers verify, then we are looking at SSTA's that rival 1997-98 and 1982-83.

Even with all the usual caveats about no guarantees, this trend is very encouraging for a continuing increase in the chances of above normal precipitation in California. Additional El Niño related links can be found at the El Niño / La Niña Resource Page.  Stay Tuned.  

Jan Null, CCM
Golden Gate Weather Services


 
 


 

 

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The Misconceptions of El Niño

Misconceptions of El Niño

 

As sea surface temperatures and their forecasts continue to rise, so does the level of hype and misinformation about El Niño in general and it's impact on California in particular.  To try and give it all a bit of a reality check please see the Misconceptions of El Niño.

In recent days, there have been several media references relating the disastrous 1997 New Year's floods and the January 1982 flooding and mudslides to El Niño.  Both of these events occurred the winter before the 1982-83 and 1997-98 El Niño events. 

Here are some other updated related to El Niño links:
El Niño & La Niña Resource Page

Oceanic Nino Index (ONI)
Latest ENSO Advisory
CPC/IRI ENSO Model Prediction Plume

El Niño / La Niña Winter Historic Precipitation & Temperatures
Climatology of El Niño Events and California Precipitation 
El Niño & La Niña...Are They Related to  California Flooding? 

Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com
 

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Summer Precipitation Anomalies During Building El Niño Events

Summer Precipitation AnomaliesDuring Building El Niño Events

 

There has been much speculation about whether the heavy and prolonged "monsoonal flow" precipitation early this summer into Southwest and the southern Plains has been a characteristic of the building El Niño. Below are the precipitation anomalies for the years where the Oceanic Niño Index was at least +0.5 for the May-Jun-Jul (MJJ) period and it was increasing, along with a composite map of all the years.  Based on the composite there does not appear to me an overriding "signal".  See http://ggweather.com/enso/summer/summer_precip.htm for individual years.



Jan Null, CCM
Golden Gate Weather Services
http://ggweather.com

 

 

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Mixed Bag - July California Climate Summary

Mixed Bag - July California Climate Summary

 

July 2015 surely defined a mixed climatological bag.  Average maximum temperatures ranged from 3.6 degrees above normal (Eureka) to 2.0 below normal at San Jose, while precipitation varied from zero (most places) to 5700% of normal at San Diego!

Even across relatively short distances there were large variations in the average maxima, with San Francisco's anomaly +2.6 and San Jose -2.0, occurring across just 40 miles.  Los Angeles and San Diego were likewise juxtaposed with -1.4 and +2.3 respectively.  Also interesting were the average minima for the month with everyone being above normal, in a range from +5.2 (Redding) to +1.7 (Fresno).

The huge variations in the rainfall were due to the influx of subtropical moisture, including the remnants of Hurricane Dolores, that produced some locally rain the southern half of the state; and also the very low normals for the month of July.

See http://ggweather.com/calif/jul2015.htm 

Jan Null, CCM
Golen Gate Weather Services

 

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El Niño Category Changes - Upon Further Review

El Niño Category Changes - Upon Further Review

 

El Niño Category Changes  - Upon Further Review

Just like a sporting event where they go to instant replay to possibly overturn a decision, the same is true with the classification of El Niño's and La Niña's.  This has happened with the dataset used to calculate the Oceanic Niño Index (ONI) and consequently the "category" of nearly a dozen El Niño and La Niña events has changed.  This was the result of the Extended Reconstructed Sea Surface Temperature (ERSST) dataset being upgraded to ERSSTv4 from ERSSTv3.  (See details and previous ONI dataset

The ONI is a retrospective tool and is used to classify past events, and sometimes the most recent month or two values may shift slightly.  It is also not the best indicator in real-time events because it is a 3-month average and may not represent recent dynamic changes very well.  For a year to be classified historically as a warm (El Niño) or cool (La El Niña) event there must be at least 5 consecutive over-lapping 3-month periods above/below the +0.5 degrees C criteria.

This updated ONI data and list of events is annotated with an asterisk to show the ones that changed a category.  In total 23% of the 3-month periods (from 1950 to present) are cooler by 0.1 deg C, 4% cooler by 0.2 deg C, 1% cooler by 0.3 deg C, 20% warmer by 0.1 deg C, 5% warmer by 0.2 deg C and 47% remaining unchanged. This resulted in 9 events decreasing a category while 2 bumped up a category.

Of most recent interest is that last winter (2014-15) is no longer historically counted as an El Niño year because JFM was adjusted to 0.4 deg C, breaking the string of 5 consecutive periods at or above the 0,5 deg C criteria for a weak El Niño.

Summary of event changes:
2014-15  - no longer El Niño
2008-09  - no longer La Niña
2005-06  - no longer La Niña
1999-00 - from strong to moderate El Niño
1994-95 - from moderate to weak El Niño
1987-88 - from strong to moderate El Niño
1979-80  - increased to weak El Niño 
1968-69 - from moderate to weak El Niño
1967-68 - increased to weak La Niña
1956-57 - no longer La Niña
1951-52 - from moderate to weak El Niño 

There are now a total of 23 El Niño events since 1950; with 12 being "weak", 6 being "moderate", 3 "strong" and 2 "very strong".  Of the cool La Niña events, there is a total of 20; with 11 in the "weak" category, 5 "moderate" and 4 "strong".

These changes necessitated a reworking of several analyses of El Niño and precipitation.  These include El Niño / La Niña Winter Historic Precipitation & Temperatures  and Climatology of El Niño Events and California Precipitation.

Jan Null, CCM
Golden Gate Weather Services

 

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