Golden Gate Weather Services

This morning it has been reported that Punxsutawney Phil did see his shadow and thus the "forecast" is for six more weeks of winter.

Groundhog Day has its roots in an ancient Celtic celebration called Imbolog. This date is the midpoint between the winter solstice and the spring equinox. In an agrarian society that was very dependent on the weather, this was a time to celebrate having made it halfway through winter. The superstition arose that if the weather was fair on Imbolog, the second half of the winter would be cold and stormy, but if the weather was cold and overcast or stormy, the second half of the winter would be mild.

In Christian times, February 2nd was also celebrated as Candlemas, but the earlier Imbolog superstition continued. In Scotland they said, ``If Candlemas be bright and clear, there'll be two winters in the year'' and in England, they said, ``If Candlemas be sunny and warm, ye may mend your mittens and look for a storm.''

The Romans learned of this tradition from the Celts, and eventually brought it with them to the area that would later become Germany. Eventually, when German immigrants came to North America they brought these beliefs to Pennsylvania. Their tradition of predicting the weather became centered on the woodchuck or groundhog, and if he could see his shadow, there would be six more weeks of winter.

A newspaper in Punxsutawney, PA helped keep the tradition alive and in 1887 declared Phil as America’s official forecasting groundhog. As the story became embellished each year the other newspapers picked it up and the rest as they say is history. Regionally there have been a number of other furry rodent contenders such as General Beauregard Lee of Atlanta, Sir Walter Wally in Raleigh, NC, and Jimmy of Sun Prairie, WI.  And in 1993 the motion picture "Groundhog Day" popularized the event even further.

NOAA's National Center for Environmental Information has summarized this tradition and its associated climatology at: https://www.ncei.noaa.gov/news/groundhog-day-forecasts-and-climate-history.
Additional information can be found at http://www.groundhog.org/.


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

What's your perfect climate? Lots of sunshine and hot temperatures? Four distinct seasons? Lots of snow for skiing or tornadoes for storm-chasing? Or maybe that decreed by King Arthur in the Broadway musical "Camelot".


In reality, it's totally subjective with no one-size-fits-all solution. With that caveat, the Camelot Climate Index (CCI), as portrayed below, was designed (as a grad school project) to be a "pleasant" climate with mild temperatures and minimal precipitation. In its latest iteration, the primary data used are from the NCDC 30-year normals for the period 1981-2010. A complete description of the methodology can be found here. Enjoy.


Camelot Climate Index

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

See: https://ggweather.com/dec1995/

Today and tomorrow (Dec 11-12) mark the 25^th anniversary of what is arguably the strongest storm to hit the San Francisco Bay Area and the West Coast in the past 70 years. It is the only time in that period that saw SF Bay Area winds in excess of 100 mph at sea level and over 130 mph on Mount Diablo. And at the same time, San Francisco recorded over 5 inches of rain in a 30-hour period while Kentfield had in excess of 11 inches. It is the strongest storm, and benchmark of the Bay Area Storm Index (BASI) with a rating of 10.0.

Dr. John Monteverdi (Emeritus Professor of Meteorology at San Francisco State University) and I have put together a webpage with some of the highlights from this remarkable event.  See https://ggweather.com/dec1995/





Jan Null, CCM
Certified Consulting Meteorologist
Golden Gate Weather Services
Phone: (650) 712-1876
Email: jnull@ggweather.com
Web: http://ggweather.com
Twitter: @ggweather

The NOAA Climate Prediction Center (CPC) announced this morning that we have entered into a weak La Niña pattern that is expected to last through the winter. https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.shtml



But, what does that mean as far as this winter's rainfall across California and the United States? Given past climatology, it can mean almost anything!  This is dramatically illustrated by the past two La Niñas, both weak, which occurred in the winters of 2016-2017 and 2017-18. Their rainfall patterns looked dramatically different, especially in the West and California. See https://www.ggweather.com/ca_enso/ca_lanina.html and https://ggweather.com/enso2016/us_lanina.html 

For comparison in California, below are the seasonal percentage of normal rainfall for the 11 La Niña events since 1950:


 

And likewise, the precipitation anomalies for the United States.


The bottom line is that with most ENSO (El Niño Southern Oscillation) events, and especially with weak La Niñas, there is no clear signal that can be used as a predictor. What is often forgotten, is that while ENSO events have a strong influence on a given year's weather, they are not the only game in town and the impact of ENSO is influenced by a myriad of other interacting factors like the North Atlantic Oscillation (NAO), Pacific North America (PNA) pattern, Arctic Oscillation (AO), Pacific Decadel Oscillation (PDO), Madden-Julian Oscillation (MJO), etc. STAY TUNED!

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