Meteorologist's Links


Spurred on by the NWS changing many of the URL's for a lot of their text products, I've updated and made some additions to my METEOROLOGIST'S LINKS page at:https://ggweather.com/home.html

Many on this email distribution are aware of this page which has been evolving for probably 20 years with handy links to products that I use almost daily. There are also links here to a number of the other resource pages that I hope are useful compilations in a single source. Enjoy.
T-Storm/Tornado Links: http://ggweather.com/tornado.htm
Hurricane Links: http://ggweather.com/hurricane.htm
Fire Weather Links: http://ggweather.com/firewx.htm
El Nino/La NIña Links: http://ggweather.com/enso.htm

Please let me know if you find any errors, broken links, or additional sites that may be of interest to meteorologists and the media.

 


 

Posted

Developing El Niño Comparisons


The eastern tropical Pacific continues to warm toward a likely El Niño event later this summer that is then forecast to continue through the winter. For the first time in 3 years, the Oceanic Niño Index (ONI) has moved back into positive territory. (See https://ggweather.com/enso/oni.htm)

This warming is seen in all the Niño Regions with the most dramatic rise in Niño 1+2 off the South American coast where the anomalies are about +2.5 °C. 



Comparing the current event to the two previous “very strong” El Niños in late May of 1997 and 2015 shows several differences. Currently, this year has not warmed as much in the west as prior years. It also shows 2015 as more of a Central Pacific event, with more similarity between 1997 and 2023.


It will be interesting to see how the current event develops over the next six months. Stay tuned.
 
Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

 

Are California Coastal Water Temperatures Warmer During El Niño?

 

Media reports of late, and during past El Niño events, have attributed the presence of warm water species of marine life along the California coast to El Niño. However, a look at the data doesn't support that conjecture. Contextually, the sea surface temperature (SST) warming associated with El Niño occurs in the tropical Pacific, approximately 3,000 miles away from California, plus there is no physical process where that equatorial water is transported to the California coast. And in the short-term, the current El Niño has not even officially formed yet, and most waters along the California coast are below normal.

Historically, during El Niño winters, there are just about equal chances of coastal water temperatures being above or below normal. The following analysis was done by looking at two separate areas along the California coast. In Northern/Central California the study area was a 2-degree square (36° to 38° N and 122° to 124° W) between about Point Reyes and Big Sur and about 100 miles offshore. In Southern California, the area was a 2-degree square (32° to 34° N and 117° to 119° W) between about Santa Barbara and San Diego and about 100 miles offshore,

During the 13 El Niño events since 1980, sorted by strength, the sea surface temperature anomalies (SSTAs) in the northern area were only warmer than normal in 6 of the 13 years.

And along the southern California coast, the El Niño year SSTAs were warmer than normal in 7 of the 13 years.


Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

 

Posted

Updated El Niño Precipitation and Temperature Anomaly Maps


I have updated the climatologies of previous El Niño precipitation and temperature anomaly maps, with all new graphics and now using "percent of normal" data. For example, below are the precipitation anomaly maps for the last two strong El Niño's; highlighting that even with a specific ENSO category there can be very large differences. 
PRECIPITATION - https://ggweather.com/enso2023/us_elnino_precip.html
TEMPERATURE - https://ggweather.com/enso2023/us_elnino_temp.html
ENSO Resource Page - https://ggweather.com/enso.htm


Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather


 

Posted

When Will Tioga Pass Open in 2023?

Due to this year's epic Central Sierra Nevada snowpack, current estimates from Yosemite National Park are that Tioga Pass will open later than usual this year; possibly not until July. To put this year into context, below is what has happened in previous years. 






Posted

El Niño Resources for 2023


 

Last week, the Climate Prediction Center issued an El Niño Watch, with the expectation that conditions in the tropical Pacific would transition into an El Niño pattern by late summer and continue into next winter. And immediately a number of headlines popped up, raising the specter of doom and gloom. The tone reminded me of the fall of 1997 and this cartoon from the Sacramento Bee:


Consequently, I have updated a number of El Niño and La Niña resources that may assist in keeping things in perspective. They are all available from the EL NIÑO / LA NIÑA RESOURCE PAGE 

.

The Oceanic Nino Index is the defacto metric widely used to classify the strength of ENSO (El Niño - Southern Oscillation).events. See https://ggweather.com/enso/oni.htm for current and historic values.


I have also put together a page of misconceptions about ENSO Events. See http://ggweather.com/enso/enso_myths.htm



This is coupled with an ENSO Glossary with some of the more common terminology. See http://ggweather.com/enso/glossary.htm



And to put historical precipitation on the types and strengths of ENSO events, the following analyzed chronologies were updated for both the United States and California. See https://ggweather.com/enso2021/  for the US, then https://www.ggweather.com/ca_enso2021/ca_elnino.html and https://www.ggweather.com/ca_enso2021/ca_lanina.html for California.




Please let me know of any errors or omissions.

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

Posted

Historical Low Level Snow in the Bay Area


 

The last widespread snowfall down to near sea level in the San Francisco Bay Area was 47 years ago, on February 5, 1976. Granted, there have been a handful of occasions since with small pockets of cold air allowing for snow to get close to sea level, but nothing widespread. And the odds against it happening later this week are small, but not impossible. The most likely scenario will be snow accumulations in areas around the bay above 1000 to 2000 feet. 

Historically, there have only been 11 days when snow has been recorded near sea level in downtown  San Francisco, Twice on February 5th; in 887 and again in 1976. (https://www.ggweather.com/sf/snow.htm). 


The event on February 5, 1887, was the snowiest on record with over 3 inches in the downtown area of the City.  This is well documented in Mark McLaughlin's wonderful  "San Francisco Snowstorms" document (http://thestormking.com/Sierra_Stories/San_Francisco_Snowstorms/san_francisco_snowstorms.html)


The 1976 event was spectacularly captured by the SF Chronicle in this photo by Art Frisch.
 
The meteorology on Feb 5, 1976, showed a cold front having moved south over the state during the overnight hours and supported by a very cold 500 mb low (5280m) west of Pt. Reyes. The 1000-500 mb thickness was 5221 meters.






The hourly observations that morning showed snow falling at San Francisco International Airport, and it may have been the last snow observation recorded at SFO, since it is unlikely to have been picked up by current automated sensors. [I remember this quite vividly as I had worked a midnight shift as an observer at SFO some of those snowy observations and then drove home to the East Bay through a winter wonderland.]




The setup for later this week shows a similar strength upper low farther offshore than in 1976, with a 5210m minima on Friday morning. But will the moisture synch up with the coldest air and at the right time of day? The odds right now look better for low-level snow south of the Bay Area.



Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

 

Posted

California Precipitation Rankings


With clearing skies over California, the current rainfall totals for the month of January seem close to final.*

For historical context, the tables below rank the 20-wettest first seven months (July through January) of the rainfall season, and how those locations ended the season in June. The two biggest takeaways:
1. Despite the impressive parade of storms in December and the first half of January, only the Central and Southern Sierra Nevada Indices barely cracked the top 10 for each location's period of record.
2.  All of these locations ended the season above normal for years that had similar amounts to where they are this year.

* Data for Los Angeles is current through 8 am January 30. A few showers still persist there, but it is doubtful that any additional rain will shift the ranking.











Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather






 

 

Posted

California Rainfall and Reservoir Updates

 

Despite recent moderate precipitation amounts across the state (https://ggweather.com/seasonal_rain.htm), the rainfall and reservoir deficits continue to grow; well beyond the capability to make up the amounts in a single season. Even after the 1.79 inches that San Francisco has received to date, the total 4-season deficit is currently over 29 inches and will be over 50 inches by the end of the season, if no rain were to fall. (San Francisco normal 22.89", SF record 49.27 in 1861-1862.)

Likewise, the critical 8-Station Northern Sierra Precipitation Index (8SI) currently has a deficit of more than an entire season. 

And these large rainfall deficits are evident in the current levels of the state's reservoirs which have steadily declined over the past 3= seasons and are at just 61% of their average mid-November storage.

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

 

 

Posted

Mini Review of Last year's CPC Winter (DJF) Outlook

ABSTRACT
Comparison of last year's NOAA Climate Prediction Center (CPC) 90-day precipitation and temperature forecasts for the winter period of December-February (DJF) 2021-2022 with the actual observed conditions.

DATA SOURCES
The 90-day (DJF) outlooks were retrieved from the NOAA Climate Prediction Center (CPC) archives and the corresponding observed temperature and precipitation data were downloaded from NOAA ESRL Climate Division Data.

ANALYSIS
The CPC Winter Outlook DJF 2021-2022 did better than in several of the recent winters, partly because the overall pattern ended up close to a "typical" La Niña.  However, it must be noted that the CPC outlooks are probabilistic versus deterministic, which makes them harder to judge as right or wrong.

Here is t subjective graphical grading used below. Overall if a forecast was in the right category (i.e., above normal was forecast and above normal was observed) it was graded as "good" and marked with a "+". Conversely, if it was the wrong category (i.e., above normal was forecast and below normal was observed then it was graded as "not good" with a "-". And if the forecast was off by a single category (i.e, above normal was predicted and it was normal) or there was a mixture of above and below in close proximity to one another then graded it as "mixed" and marked with a "0".  

SUMMARY
Of the 41 precipitation regions compared, 14 (34%) regions rated as "good", 10 (24%) as "not good" and 17 (41%) as "mixed".
Of the 39 temperature regions compared, 20 (51%) regions were rated as "good", only 1 (3%) as "not good" and 18 (46%) as "mixed".

However, it is left to the individual reader to do their own comparisons and evaluate the relative usefulness of the forecasts to their particular activity.



Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

Posted