Golden Gate Weather Services

CPC Winter Outlooks and an Updated El Niño Forecast

With the latest NOAA 2018-2019 Winter Outlook just released, here's how the previous three CPC Winter Precipitation Outlooks "verified". At least here on the West Coast they seem to have pretty much missed the mark.

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And the just updated IRI/CPC Oceanic Niño Index (ONI) forecast is significantly warmer than last month's; pushing the winter months into the moderate El Niño category.

However, even in the moderate El Niño category there is still a large range of solutions and little predictive value. See https://www.ggweather.com/ca_enso/ca_elnino.html for the California and https://www.ggweather.com/enso2016/us_elnino.html for the US.

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

New & Improved El Niño (and La Niña) California Precipitation Climatology

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The Climate Prediction Center (CPC) currently has an El Niño Watch for this coming Fall and Winter, though they have been gradually decreasing its probability of occurrence in recent months.

I have put together a new & improved comprehensive California Precipitation climatology for ENSO (i.e., El Niño and La Niña) events. See
https://www.ggweather.com/ca_enso/ca_elnino.html and https://www.ggweather.com/ca_enso/ca_lanina.html.

The climatology is based upon the 10 California Hydrologic regions (map) and generated with the updated (and excellent) Western Region Climate Center's California Climate Tracker tools.

As always, corrections, comments and corrections are greatly appreciated.

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

PG&E and SoCal Edison Mesonets

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In recent months both Pacific Gas & Electric (PG&E) and Southern California Edison (SCE) have been installing extensive weather station networks. Primarily mounted on utility poles they gather wind, temperature and humidity data every 10 minutes. Currently PG&E has about 100 stations online and SCE about 70 stations; and it is my understanding that more are being installed. (San Diego Gas & Electric (SDG&E) has had a similar mesonet of about 150 stations for about 5 years) The data is available on MesoWest and on via NWS graphical interface. However, neither MesoWest or the NWS page let's one parse out just these mesonets, so I have put together a couple pages, both in tabular and map/graphical form.

PG&E: Table, Map
SCE: Table , Map
SDG&E mesonet
These have both been added to the Mesonet section on my Meteorologist Links page.

Enjoy and please let me know of any comments or suggestions.

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

California Summer Temps Mostly Above Average - Recap

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Meteorological summer (i.e., June, July, August) has ended and most of the Golden State ended up with above normal temperatures. The biggest anomalies were over the southern half of the California and over the northern interior.
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Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (408) 379-7500
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

San Francisco still a month away from average hottest day

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San Francisco is still a month away from their normal hottest day of the year! Conversely, most other cities around California and the nation are well past their normal hottest day, which typically occurs about a month after the Summer Solstice. But a few locations, especially along the West Coast, wait until August and even September to peak. And San Francisco is certainly the latest of any major United States city by not reaching its normal highest maximum temperature of 70.4 until September 24t. Image: https://gallery.mailchimp.com/204b7b5836feabf8f536d0226/images/c03ef7b3-e82f-4033-a310-b54eaddf2945.jpg
Source: http://ggweather.com/normals/daily.htm

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (408) 379-7500
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

El Niño Rainfall Climatology

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With the eastern tropical Pacific warming and most forecasts leaning toward at least a weak El Niño event this coming winter I have put together a new climatology looking at early-August conditions relative to the subsequent rainfall season. I have also updated several previous ENSO climatologies with regards to rainfall and temperatures.

New: Early August Comparative Weak/Moderate El Niño Seasonal Rainfall Climatology

Updated: US Winter Precipitation & Temperature Climatologies: El Niño | La Niña
Updated: California El Niño Precipitation Climatology
Updated: California La Niña Precipitation Climatology

Updated links to all of the above and more at EL NIÑO / LA NIÑA RESOURCE PAGE

Summary of California 2017-2018 Rainfall Season Ending Tomorrow

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The California 2017-2018 rainfall season ends tomorrow with totals across the state below normal and on the order of half of the totals recorded in 2016-17. See http://ggweather.com/ca2017rain.htm and http://ggweather.com/ca2016rain.htm.

See also the Precipitation Snapshot at http://ggweather.com/water/

Also the Western Region Climate Center's Precipitation Anomaly maps from https://wrcc.dri.edu/anom/cal_anom.html

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

Updated Resource Pages; Tioga Pass by the Nummbers

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I have updated the following Weather Resource pages for 2018. But please let me know of any errata, suggestions or additions. Enjoy.

2018 Thunderstorm and Tornado Resource Guide

2018 Hurricane Resource Guide

2018 Fire Weather Resource Guide

~~~~~~~~~~~~~~~~~~~~~~~~

With Tioga Pass due to open Monday (5/21/2018) here are some historical records going back to 1980.

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (408) 379-7500
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

Beware Daily Weather Records!!

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During big rain events, a particular rainfall amount may be touted as record rainfall for the date, just as during hot weather the temperature may be proclaimed a daily maximum record. Ideally, meteorological data should be based on where we are in our orbit around the sun and not a particular calendar day. This is because our calendar is slightly flawed when it comes to specific days as it takes 365.25 days to circle the sun giving us a leap day every four years.

Consequently, the dates in a leap year after February 29^th, are all displaced by one day. That is, April 6^th in 2017, 2018 and 2019 is the 96^th day of the year, while April 6^th in a leap year (i.e., 2016, 2020) is the 97^th day. So, if a record event for a particular date happened in a leap year versus a non-leap year we are actually comparing different days based upon of position relative to the "solar year".

For example, the largest rainfall amount for San Francisco for April 21^st is 1.39” in 1880, a leap year so it was the 112^th day of that year. But the record for April 22^nd, is 0.43” in 2007, not a leap year so it is also the 112^th day of the year!
Which is correct? The bottom line is that neither is really right all of the time!

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (408) 379-7500
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

1 & 2-Day SF Bay Area April Rainfall Records

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1 and 2 Day SF Bay Area April Rainfall Records

One Day Record

Two Day Record

Name

Rain (in.)

Date

Rain (in.)

Date

Since

ALAMEDA COUNTY

BERKELEY

2.49

1896-04-24

4.04

1958-04-02

1893

FREMONT

0.96

2003-04-13

1.62

2003-04-13

1996

HAYWARD AIR TERMINAL

0.98

2012-04-10

1.65

2003-04-13

1998

LIVERMORE

1.80

1958-04-03

2.10

1958-04-04

1903

LIVERMORE MUNICIPAL AP

1.14

2003-04-12

1.79

2003-04-13

1998

NEWARK

1.41

2003-04-13

1.46

2003-04-14

1906

OAKLAND INTL AP

2.03

1974-04-01

2.24

2012-04-13

1948

OAKLAND MUSEUM

2.07

1974-04-01

2.10

1974-04-02

1970

TRACY PUMPING PLANT

1.10

1983-04-28

1.70

1983-04-28

1955

UPPER SAN LEANDRO FILTERS

2.20

1974-04-02

3.12

1974-04-02

1948

CONTRA COSTA COUNTY

CONCORD BUCHANAN FIELD

0.97

2012-04-12

1.54

2017-04-07

1999

CONCORD WASTEWATER PLANT

1.20

2017-04-07

1.91

2017-04-08

1991

MARTINEZ WATER PLANT

1.50

2003-04-13

1.81

2017-04-08

1970

MOUNT DIABLO JUNCTION

2.35

1958-04-03

2.90

1958-04-04+

1952

RICHMOND

2.32

1953-04-27

2.48

1982-04-11

1950

MARIN COUNTY

KENTFIELD

4.95

1935-04-07

5.31

1935-04-08

1902

SAN RAFAEL-CIVIC CENTER

4.39

1896-04-25

5.24

1958-04-02

1894

MONTEREY COUNTY

BIG SUR STATION

4.50

1982-04-11

6.37

1982-04-11

1915

CARMEL VALLEY

1.60

2006-04-05

2.27

2006-04-05

1959

KING CITY

1.58

1982-04-10

2.25

1912-04-10

1902

MONTEREY

2.11

1974-04-01

2.36

1912-04-11

1906

MONTEREY PENINSUL AP

1.23

1969-04-05

1.47

1969-04-06

1968

MONTEREY WFO

1.45

2006-04-04

1.68

2006-04-04

1995

SALINAS AP

2.15

1974-04-01

2.15

1974-04-02

1930

SALINAS NO. 2

2.09

1974-04-01

2.58

1974-04-02

1958

NAPA COUNTY

ANGWIN PACIFIC UNION COL

3.08

1982-04-11

3.82

1982-04-11+

1940

CALISTOGA

2.65

1911-04-05

5.26

1996-04-02

1906

MARKLEY COVE

2.64

1982-04-11

2.94

1982-04-12

1970

NAPA COUNTY AIRPORT

1.07

2017-04-06

1.85

2017-04-07

1998

NAPA STATE HOSPITAL

2.66

1996-04-01

3.23

1958-04-03

1893

SAINT HELENA

3.52

1927-04-01

5.64

1926-04-05

1907

SAINT HELENA 4 WSW

2.20

2010-04-12

2.88

2017-04-08+

1948

SAN BENITO COUNTY

HOLLISTER 2

1.43

1981-04-19

1.63

1981-04-20

1948

PANOCHE 2 W

1.14

1958-04-03

1.24

1957-04-18

1949

PINNACLES NM

2.17

1958-04-03

2.39

1958-04-04

1937

SAN FRANCISCO COUNTY

SAN FRANCISCO DOWNTOWN

3.45

1853-04-16

3.59

1853-04-17

1849

SAN FRANCISCO OCEANSIDE

1.45

1978-04-15

1.50

1978-04-16

1948

SAN MATEO COUNTY

HALF MOON BAY

2.36

1941-04-04

2.54

1953-04-27

1939

REDWOOD CITY

2.54

1958-04-02

3.90

1958-04-02

1906

SAN FRANCISCO INTL AP

2.30

1958-04-02

3.21

1958-04-02

1945

SKYLINE RIDGE PRESERVE

2.75

2003-04-13

2.96

2003-04-13

1995

SANTA CLARA COUNTY

GILROY

3.65

1958-04-03

4.07

1958-04-04

1906

LOS GATOS

3.70

1901-04-29

5.89

1958-04-02

1893

MOFFETT FEDERAL AIRFIELD

1.17

1958-04-02

1.73

1983-04-28

1945

MOUNT HAMILTON

1.87

1965-04-09

3.38

1965-04-10

1948

SAN JOSE

1.46

1983-04-28

2.06

2006-04-04

1893

BEN LOMOND NO. 4

5.35

1941-04-04

7.15

1958-04-02

1937

SANTA CRUZ

3.75

1923-04-04

4.05

1923-04-05

1893

WATSONVILLE MUNICIPAL AP

1.51

2006-04-04

2.24

2012-04-13

1945

WATSONVILLE WATERWORKS

2.85

1983-04-28

3.15

1983-04-29

1908

SONOMA COUNTY

BODEGA 6 WSW

2.28

2010-04-11

2.42

2010-04-12

2008

CLOVERDALE

2.80

1982-04-11

4.20

2010-04-12

1950

FORT ROSS

4.23

1953-04-27

5.36

1953-04-27

1895

GRATON

4.00

1953-04-27

4.61

1926-04-05

1926

HEALDSBURG

3.25

1953-04-27

4.57

1927-04-02

1893

OCCIDENTAL

5.20

1953-04-27

5.49

1953-04-28

1943

PETALUMA AIRPORT

2.45

1941-04-04

4.40

1926-04-05

1893

SANTA ROSA

3.06

1926-04-04

5.99

1926-04-05

1902

SANTA ROSA SONOMA CO AP

2.36

2017-04-06

2.77

2017-04-07

1998

VENADO

4.68

2006-04-12

5.29

2017-04-08

1948

Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (408) 379-7500
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: https://twitter.com/ggweather
Facebook: https://www.facebook.com/Golden-Gate-Weather-Services-151100414926621/

Jan Null

Jan Null has been a meteorologist in the San Francisco Bay Area for 50 years and is frequently seen on television and heard on the radio when weather is in the news. Twenty-six years ago he founded a consulting firm, Golden Gate Weather Services, after a 24-year career with the National Weather Service. Mr. Null is a Bay Area native, having grown up in Oakland and lived in the East Bay until 2006 when he moved to Saratoga. He received a Bachelor of Science degree in Atmospheric Science from UC Davis in 1974 and his Master’s from San Jose State in 1992. Jan joined the National Weather Service in 1974 at the Weather Service Forecast Office in Redwood City. He worked as an operational forecaster throughout his career, including 13 years as Lead Forecaster. During his tenure at the NWS he also served as Meteorologist-in-Charge at the Center Weather Service Unit at the FAA’s Air Traffic Control Center in Fremont. He also did extensive research into the relationship between El Niño, La Niña and California rainfall and throughout his career he was a frequent media spokesperson for the agency. Jan has also been an Adjunct Professor and Lecturer at San Francisco and San Jose State Universities where he taught one evening a week for nearly 30 years. In 1998, Jan founded Golden Gate Weather Services, a consulting firm that specializes in forensic meteorology. He frequently serves as an expert witness in litigation where the weather is a factor. This often involves reconstructing past weather events or as his wife refers to it: “CSI Weather”. Mr. Null is also an internationally recognized expert of the sad topic of the heatstroke deaths of children in vehicles. After the death of a child left a vehicle in San Jose in 2001 he did a comprehensive study of vehicle temperatures that was ultimately published in Pediatrics in 2005. Since that time he has spoken at numerous national conferences and worked with a wide variety of child safety advocacy groups and agencies to raise awareness about the dozens of children who die from hyperthermia in hot vehicles each year. This data continues to be updated at NOHeatstroke.org. In his spare time he is a serious amateur photographer, specializing in wildlife and landscapes. Jan is married to Susan Hollis, a lifelong Saratoga resident and Realtor. He has two adult children in the Bay Area and the world’s most adorable 9-year old granddaughter and 4-year grandson.

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