Updated Thunderstorm and Other Resource Pages

With the severe weather season beginning to crank up I have updated a number of resources pages.  See 

Thunderstorm and Tornado Resources 2015 - http://ggweather.com/tornado.htm 

Hurricane Resource Page 2015http://ggweather.com/hurricane.htm 

2015 California & National Fire Weather Forecasts and Linkshttp://ggweather.com/firewx.htm 


Please let me know of any corrections, additions or comments to make them better.

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There's an excellent new "animated streamline" map that has the ability to display GFS forecast streamline maps, plus current observations and forecast plus nearby webcam.  See https://www.windyty.com.

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All of these, and many more links are on the Meteorologist's Links Pagehttp://ggweather.com/home.html 


I am also tweeting out these and other weather-related information.  My Twitter handle is @ggweather


 

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Two Decades of CPC Winter Outlook Skill Score Verification

A recent CPC blog post said:  "We recommend that you track the verification skill scores over time (not just for one forecast), as they give you a feel for whether you should trust them or not.  Any individual forecast could hit the mark or be way off".  Consequently, below are the CPC seasonal forecasts for winter for the past 20 years. It is left to the reader to assess how "skillful" these outlooks are.

For the full breakdown see  http://ggweather.com/cpc/verify/cpc_winter.htm

http://ggweather.com/images/hss_resize.jpg

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

http://ggweather.com/PHPlist/ut.php?u=5a7eb2c1449b144646514dd004f4b1a9&m=665

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Nothing "Official" About the Equinox

Is the date and time of a full moon called the "offical full moon" or the definition of "pi" called the "offical value of pi"? So, why do so many call the Vernal (Spring) Equinox, which occurs today at 3:45 pm pdt (2245 utc/gmt), the "official" beginning of Spring. It is simply an astronomical event that defines when the plane of earth's equator passes the center of the sun causing the earth's axis to be perpendicular to its orbit around the sun. It is not a weather event and no one or no agency issues a proclamation making it "official" anyway.

And meteorologically, Spring is defined as the months of March, April and May.

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

 

CPC Winter Forecasts in Review

As I have done in recent years, I went back and looked at how good or bad the forecast from the NWS/CPC was for the just finished winter (December, January, February). While there were some hits, but a couple of colossal fails dominated.  For the second year in a row the Outlook was for above or near normal temperatures in the Northeast!  NOT!  And the precipitation forecast was for above normal rainfall across the southern two-thirds of California.  NOT!  

For the details see http://ggweather.com/cpc/2015/ 

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El Nino Upgraded from Watch to Advisory

Too little, too late?

CPC has upgraded their El Nino Watch to an El Nino Advisory <http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ensodisc.html>, but with only a 50-60% chance it will persist through summer.  The upgrade is despite the ONI dipping from +0.7 to +0.6. <http://ggweather.com/enso/oni.htm> and during a time of year when the influences of El Nino are waning.


An excellent analysis of these potential impacts can be found at http://www.climate.gov/news-features/blogs/enso/march-2015-enso-discussion-el-ni%C3%B1o-here.

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

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February 2015 California Climate Summary

In general the Golden State saw a dry and warm February.  Average maxima at Eureka was "only" 3.4 degrees above, while the remaining key cities ranged from 5.4 (San Diego) to 8.4 (Redding) above normal. See http://ggweather.com/calif/feb2015.htm 

 

February 2015 rainfall generally ranged from more in the north to less in the south.  Eureka was 90% of normal while San Diego totaled only 8% of normal with most locales in the middle between about 33% to 66%. See http://ggweather.com/calif/feb2015.htm

 

Correspondingly, season to date rainfall numbers slipped; but on the weight of our very wet December they are still better than some of the previous years.  SF Bay Area season to date numbers are mostly between 90% and 110% of normal, while statewide key cities percent of nomal values range from 75% to 99% of normal. See  http://forecast.weather.gov/product.php?site=NWS&product=RR4&issuedby=MTR 

 

In the key Sierra Nevada basins the 8-Station Northern Sierra Precipitation Index is at 90% of normal while the 5-Station San Joaquin Index is only at 49% of normal.  See http://cdec.water.ca.gov/cgi-progs/products/PLOT_ESI.pdf and http://cdec.water.ca.gov/cgi-progs/products/PLOT_FSI.pdf 

 

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

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Pebble Beach Weather

What a difference a week makes! If the AT&T Pebble Beach Pro-Am Golf Tournament had been played last week it would have been what many think of as "typical Crosby weather".  In fact, it has only rained on 58% of the years during the tournament.  See http://ggweather.com/pebble.htm for a year-by-year breakdown of rain during this event.  

This year it will picture postcard weather with temperatures in the low to mid-70s.

 

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SF Dry Spell Ends at 43 days

With 0.01" of rain being recorded this morning between 08:00 and 09:00 am the dry spell in downtown San Francisco has ended at 43 days. The last measurable rain in SF was recorded on December 24, 2014 making this the second longest winter dry spell since records began during the Gold Rush in 1849. The record is 60 consecutive days set between November 17, 1876 and January 15, 1877.

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

 

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National Weatherpersons' Day

February 5 commemorates the birthdate of John Jeffries (1744) as National Weatherpersons’ Day; a day that recognizes the contributions of meteorologists in the United States.  Jeffries (1744-1819) was one of America's first weather observers, having begun to take daily weather observations in Boston in 1774 and took the first balloon weather observation in 1784.

Born in America, he trained as a physician in England and was the Surgeon General for British Forces in North America during the Revolutionary War.  Historically he is best known in his era for the first balloon flight across the English Channel with Frenchman Jean Pierre Blanchard  on January 7th 1785.

 

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Atmospheric Rivers - Background Information

Below are a number of links relating to Atmospheric Rivers (ARs). These relatively narrow (~240 miles) slow moving bands of subtropical moisture account for between 30% and 50% of the rainfall occuring along the West Coast. Many of Washington, Oregon and California's historic flooding events have been related to ARs. They are also colloquially known as the "Pineapple Express" because some of their moisture originates from the vicinity of the Hawaiian Islands.


http://www.esrl.noaa.gov/psd/atmrivers/

http://www.esrl.noaa.gov/psd/atmrivers/questions/ 

http://tenaya.ucsd.edu/~dettinge/Dettinger_Ingram_sciam13.pdf  

http://pubs.usgs.gov/of/2010/1312/of2010-1312_text.pdf 


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

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