Warm California Coastal Waters Not Necessarily El Niño Related

Warm California Coastal Waters Not Necessarily El Niño Related

 

In recent days there have been numerous reports of warmer than normal water along the California coast as well as an abundance of sharks, red crabs and dead marine life washing ashore. And in too many reports there has been at least an implied linkage to El Niño.  But the warmer than normal water associated with El Niño occurs in the tropical Pacific, about 2500 miles southwest of California.  Historically, the waters along the northern and central California coast have been above normal during only about half (55%) of the El Niño events since 1950, and 64% of the times in the Southern California coastal waters. (See #7 at http://ggweather.com/enso/enso_myths.htm )

It should also be noted that California coast waters were also well above normal last summer, long before the formation of the current El Niño. This warming is more likely associated with the "warm blob" in the northeast Pacific, which is likely a byproduct of the persistent ridging off the west coast that has been the prime factor in the ongoing drought.

To view historic Sea Surface Temperature (SST) anomalies worldwide see http://ggweather.com/sst.htm. The clickable map is for the north Pacific but there is data for the entire globe via a pulldown menu. The data can also be displayed as a time series.  Thanks to Scott Archer of IPS Meteostar for his programming wizardry in helping make this data so easily accessible.


Jan Null, CCM
Golden Gate Weather Services

 

Posted

2014-15 Rainfall Season in review

2014-15 Rainfall Season in review

Today is the last day of the California rainfall season (July 1 to June 30) and as expected it was another dry year.  Most of northern California was between about 70% and 80% of normal, with central California having a wider range between 55% and 80%, and southern California mostly between 50% and 60%.  There were a few outliers in each category, primarily boosted by singular convective events.  

The important Sierra Nevada precipitation indices were equally low with 71% in the northern Sierra Nevada and less than 45% of normal in central and southern Sierra.  See http://ggweather.com/ca2014rain.htm





Jan Null, CCM
Golden Gate Weather Services

Posted

California's 4-year Rainfall Deficit

California's 4-year Rainfall Deficit

These tables and chart show the total deficit in California rainfall since the 2011-2012 season July 1 to June 30) in both inches and percent of normal.

For example, San Francisco is 31.63 inches behind their normal four-year total.  Consequently, to make up all of the deficit, the rainfall that San Francisco would need this coming season would be 55.28" (i.e., 31.63" + 23.65") or 234% of normal. [The all time record for San Francisco is 49.27"!!]

It should be noted that making up the rainfall deficit is very different than the requirements to "end the drought" as the components of a drought are dependent upon a myriad of variables like the type of user, population, existing supplies etc.

Also online at http://ggweather.com/4-year_deficit.htm 




Jan Null, CCM
Golden Gate Weather Services
 

 

Posted

Models Even Stronger with Upcoming El Nino

Models Even Stronger with Upcoming El Nino

 

The just released IRI/CPC mid-June ENSO Prediction Plume forecasts an even from stronger El Niño event than the previous two months.  And this forecast is important in that it is past the Spring Predictability Barrier. Here is a comparison of the last three dynamic model plume forecasts.

 

The current mean of the 17 dynamic forecast models is 1.8 in the October-November-December period, but in looking at the individual members that make up the mean, there are seven of the models that exceed 2.0, including the Japanese model (2.7), NASA (2.5) and both NOAA and ECMWF at 2.4. 



And now the usual caveat that El Niño does NOT guarantee any particular meteorological outcome, for example above normal rainfall in California.  However, the stronger the El Niño event (i.e. ONI) the higher the probability of above normal rain in California and other impacts in the United States and other parts of the world.  See El Niño / La Niña Winter Historic Precipitation & Temperatures and Climatology of El Niño Events and California Precipitation.


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

 

Posted

One Hot Day in NOT a Heat Wave!

One Hot Day in NOT a Heat Wave!

 

I have searched high and low but I can't find anything that defines a single hot day as a "Heatwave".  Yet headlines and breathless newscasters have insisted on calling this past Monday and now the warm-up expected tomorrow "heatwaves".

Climatologically, this type of weather is to be expected.  For example, Livermore averages two 100-degree maximum days in June while San Jose averages four 90-degree days.  It is occasions when there are multiple consecutive days that are a these levels (and minimums remain abnormally high overnight) that really constitute a "heatwave"   

Here are a couple definitions of heatwave:
- World Meteorological Organization:  "...when the daily maximum temperature of more than five consecutive days exceeds the average maximum temperature by 5 °C..."

- National Weather Service Glossary:  A period of abnormally and uncomfortably hot and unusually humid weather. Typically a heat wave lasts two or more days.
 
   

That being said, it is always advisable for persons to take precautions to protect themselves and others when there is abnormally hot weather, especially early in the year when most are not acclimated.

Jan Null, CCM
Golden Gate Weather Services

 

Posted

Cool May Gray

Coastal areas of California had a cool gray May while statewide rainfall for the month ranged from to zero to over 12 times normal.

 

A saggy trough of low pressure aloft made the marine layer a nearly permanent fixture for the month. Consequently cities near the coast were mostly 2 to nearly 6 degrees below normal, though San Diego managed to be just 0.6 below normal.  Inland it was also cooler than normal in most areas, though Redding in the northern Sacramento Valley was three degrees above normal while Sacramento, only  150 miles to the south, felt the persistent marine layer and was 3.2 degrees below normal.

 

In San Jose, after an 84 degree max on May 1st not a single day exceeded normal. For the month San Jose's average May 2015 maxima of 68.6 degrees was 5.7 cooler than its normal of 74.3 degrees, the coolest May since 67.97 degrees in 1977. (Their record coolest May is 66.81 inches in 1915.) It was also the first month below normal in San Jose since last September.

 

San Francisco was similarly cool, with only May 1st topping 64 degrees all month. And it was the 1st time since September 2013 that the average monthly maxima was below normal!

 

The persistent trough also produced several significant rain events on the South Coast, with San Diego's 2.39" for the month was their wettest May since 2.54 in 1921, and 1292% of normal. Elsewhere rainfall was hit or miss and highly variable with generally drier amounts north.

 

See http://ggweather.com/calif/may2015.htm 

 

 

Jan Null, CCM

Golden Gate Weather Services

http://ggweather.com

Posted

Updated El Niño Climatologies and Forecasts

Updated El Niño Climatologies

With many of the May versions of the SST ONI forecasts beginning to show El Niño strengthening well into the strong category (see below) I have updated a number of El Niño climatologies to add a "very strong" category. Each of the previous categories (Weak, Moderate, Strong) spanned a half degree anomaly on the ONI and it seemed logical to add a category for the next step of greater than or equal to an ONI of +2.0.  See El Niño and La Niña Years and Intensities (ONI).

This moved two years (1982-83 and 1997-98) from the strong category to "very strong" and an examination of these two years understandably shows the most definitive signature for rainfall for California.  [The 1972-73 season fell just shy of the meeting the "very strong" criteria, but certainly exhibited a similar very wet California outcome.] See El Niño and La Niña Winter Historic Precipitation and Temperatures and Climatology of El Niño Events and California Precipitation.

Important Caveat:  These are climatologies of past events and are made up of a broad range of events from a small sample that are averaged together.  Consequently, like all averages, this type of data should not be used as a forecast! Or as your stock broker says "Past performance is no guarantee of future result." 

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

Updated El Niño Forecasts

The new mid-May plume of forecasts come out from IRI/CPC on Thursday (5/21) but many of the individual elements are already available and showing significant warming in future months across the eastern equatorial Pacific.
NOAA Ensemble Mean 
ECMWF Nino Plumes
Australian BOM Nino3.4 Outlook 


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

Posted

El Niño Forecasts - Past and Present

El Niño Forecasts - Past and Present

 

Following yesterday's latest NOAA El Niño Advisory there is, similar to last spring, already talk about the upcoming "strong El Nino".  However, a look at the actual model data from April 2014 and April 2015 does not support this. [Neither did the forecast from last year]




The most robust 2015 model is the NCEP CVSv2, but it was also one of the strongest last year and we know how that came out! 

Yes, we are starting off warmer (i.e., a higher Oceanic Niño Index) than last year and this certainly portends the current event persisting and being stronger than last year. But from what the models are actually saying it's still early to say if or when it will reach the strong threshold.

And then there are the comparisons to the very strong event of the winter of 1997-98! From what I am seeing so far, it is WAY too early to compare the two. The current (FMA) ONI is at +0.6, while the ONI for FMA 1997 was already at 1.4. Likewise, the water temperatures of the upper 300 meter along the equator is +1.4 anomaly, while back in 1997 it was +1.9.  There are lots of other comparative metrics to look at and a significant Kelvin wave is bringing warmer subsurface water into the eastern tropical Pacific; but this also happened last year about this time.

Bottom line: too early to tell.

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

 

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Posted

Heatstroke Deaths of Children in Cars

Even as temperatures are just beginning to rise this Spring there has already been the first 2015 juvenile heatstroke death when a 2-1/2 year old boy died last week in a hot car in Phoenix.  But it doesn't even need to be a blazing hot day in a southern state for these tragedies to occur as evidenced by deaths last year in places like Oregon and Michigan on relatively mild days.

 

Most people may have seen media reports about an isolated incident or two of a child dying in a hot car, but when put into a nationwide context there is an epidemic. On average 37 young lives are lost every year in the United States.  Since 1998 over 636 infants and  children have died horrible deaths due to heatstroke inside hot vehicles.

 

These incidents cross every socio-economic classes, from professionals like attorneys, professors and dentists to white collar engineers to blue collar workers to the unemployed. Over half (53%) of juvenile vehicular heatstroke fatalities occur when a caregiver is somehow distracted and accidentally leaves a child in a vehicle, most often when the child was supposed to be dropped off at either childcare or preschool.

 

Another 29% of the heatstroke deaths occur when children playing in vehicles are overcome by the heat.  And the saddest group is comprised of the remaining 17% of the children who died in hot cars after being intentionally left in vehicles by a caregiver who chose to run an errand, get their hair done, go to bar or the casino, etcetera.

 

Heatstroke (aka extreme hyperthermia) describes heat-related illnesses when a body’s temperature exceeds its normal range and loses its ability to cool itself. This is exacerbated in infants and children whose body’s heat up three to five times faster than adult.  When a person’s body temperature reaches 104 degrees (the clinical definition for heat stroke) their cooling system is overwhelmed to the point it begins to shut down.  A person with heatstroke may experience symptoms that include confusion, faintness, strong and rapid pulse, and possible delirium, hot dry skin or even unconsciousness.  Continued exposure to very high temperatures can produce brain damage and other organ failure.  At 107 degrees, cells within the body start to die and organs begin to shut down, quickly leading to death.

 

A car, truck, SUV or van heats up rapidly to lethal temperatures in a very short period of time.  This author began research on the topic in 2002 that was subsequently published in Pediatrics and is continuing and kept up-to-date online at noheatstroke.org.  The research found that temperature readings inside a closed vehicle peak at between 40 and 50 degrees above the outside air temperatures with about two-thirds of the rise in the first 20 minutes.  Consequently, even on a mild 70 degree day temperatures can reach readings that can be fatal to an infant or small child.  The research also found that “cracking” the windows had a negligible effect on the temperature.

 

This research has become a “go to” source  on the topic and is used worldwide.  It is hope that interest in this sad topic will raise the level of interest and awareness and ultimately to save some innocent lives.  The bottom line is that each and every one of these deaths

is 100% preventable.  Infants and children are the most precious cargo that is ever transported in a vehicle and we should always be cognizant of the potential dangers to a child left alone in a car.

 

Please take a moment to share this information either personally or via social media with your family, friends and colleagues. It might save a life.

 

Jan Null, CCM

San Jose State University

mailto:jan.null@sjsu.edu