Hurricane Joaquin is still churning out in the open Atlantic more than 14 days since it become a tropical depression on September 28th in the Caribbean.
The official track from the NHC has it sustaining tropical characteristics through the upcoming weekend as it tracks as it approaches Europe.
This had me wondering what the furthest NORTH any hurricane has traveled. The award goes to Hurricane Faith in 1966. This system started out off the coast of western Africa, headed toward the Caribbean then north off the coast of the U.S. then out to sea. It lasted 26 days and traveled more than 6800 miles.
What I find fascinating is that according to the official track data (wind, position and date) it held hurricane strength over incredibly cold water. The hurricane crossed into water below 20 degrees Celsius off the coast of Nova Scotia yet it stayed at category 2 strength for another two and a half days.
WATER TEMPERATURE IN CELSIUS
The storm didn't officially weaken until it reached the north of Great Britain where the water temperatures dropped to between 10 and 12 degrees Celsius. The "X" marks the approximate location where Hurricane faith was downgraded to a tropical storm....yet it continued as an extra tropical storm/low into Scandinavia for another week!
The National Hurricane Center has a great summary on the hurricane season that year. They show a map of Faith denoting its movement into the arctic north of the Arctic Circle into the Soviet Union then north into the Barents Sea where water temperatures were barely above freezing.
Air temperatures were in the 30s and 40s.
It finally ended its journey over an uninhabited island chain north of the Arctic Circle around 600 miles from the North Pole.
As this current El Nino continues to evolve, it helps to visualize how these changes in the tropical Pacific ocean temperatures drive the changes in the hemispheric circulation which impact our winter weather across the US.
How do we define an El Nino? The Climate Prediction Center uses the ONI (Oceanic Nino Index) to define El Nino and La Nina events. Their definition for El Nino/La Nina using the ONI is as follows:
An El Nino event is defined when the three month running mean of (ERSST.v4) sea surface temperature anomalies in the Niño 3.4 region climb above the threshold of 0.5o for five consecutive overlapping three month periods.
In other words, we take the average ocean temperature anomaly in the 3.4 region over a 3 month period, say September through January. Take the next five month overlapping periods--October through December and November through January--(the first two for example) and find these averages. That is your five consecutive, 3 month running mean. If this period's average is at or above +0.5 degrees, we classify this as an El Nino. The ERSST.v4 dataset goes back to 1850. Using this methodology, the top 10 strongest E Ninos are easy to find. Hat tip to Eric Webb for compiling the ERSSTv4 data.
The top ten El Ninos are as follows: 1877-78, 1888-89, 1982-83, 1997-98, 1896-97, 1902-03, 1905-06, 1940-41, 1957-58, 1972-73 What do the sea surface temperatures for each of these El Ninos look like? I created an animation of each El Nino's six, three month overlapping period starting with the September-November period ending with the February-April period. Each El Nino evolves differently. The position of the equatorial warm water, position and strength of the warm/cool pools in the PDO region are different with some, similar to others. Here is each sea surface temperature anomaly animation from the list above.
1877-78 El Nino
1888-89 El Nino
1982-83
1997-98
1896-97
1902-03
1905-06
1940-41
1957-58
1972-73
How does the atmosphere respond in each of these cases at the 300mB level? More on this later.
What were the winter temperatures like in each of these strong (both eastern and central) El Ninos?
One glaring similarity is that each of these El Nino events (1888-89, 1940-41 and 1957-58) average temperatures across the eastern US stayed close or slightly above average in December and in January. Then in February, the bottom falls out and temperatures drop significantly below average across a large area of the east. If you look at the Pacific sea surface temperature configuration of these winters (eyeballing the ENSO region, Eastern Pacific/west coast/Gulf of Alaska regions and Pacific Meridional Mode area), they closely resemble this year!
Last year at this time (Spring 2014) the talk of a "Super El Nino" was at the forefront of weather circles. The resultant El Nino later in the year surely didn't fit the hype for a variety of reasons. This year's close El Nino cousin is a little different. I believe the "hype" is more warranted this go-around.
Here is a great El Nino animation from NASA showing its evolution.
Using the ONI (Oceanic Nino Index), I logged all El Ninos since the early 1900s. The ONI is a 3 month overlapping sea surface temperature anomaly index of the Nino 3.4 region, the area used in defining the ENS state.
In determining how different this evolving El Nino is compared to past events, I used the actual NON-OVERLAPPING monthly Nino 3.4 sea surface temperatures anomalies for each early stage El Nino event starting in March and continuing through December. My goal was to see any slight variation in ocean temperature that was smoothed by the 3-month overlapping ONI. Note: Many of these El Nino events continued into the following year not shown here.
The first chart below shows El Nino events from 1982 to early 2015.
Some key points: This year's event has started MUCH FASTER and earlier than the historic El Nino events in 1997 and 1982. The 1986-87 event peaked in summer then slowly dropped by fall after a similar start.
The current El Nino is well ahead of all of the events from the early 1950s through the late 1970s. Some of these El Ninos were weak. 1965 and 1972 was strong.
The El Ninos of the late 1920s, 30s and 40s were late bloomers showing little sign of El Nino until mid fall.
The early 20th century El Ninos had more erratic evolutions. Even the strong El Nino of 1918 struggled until fall/early winter.
Of all 23 El Ninos I charted, only the El Nino of 1905 had WARMER ocean temperatures in May compared to this year's event. That year peaked at 1.5 in September.
So in summary...
* El Nino headlines need historical perspective. Don't be quick to compare this event to the 1997 event per the model projections.
* The 2015 El Nino is building faster than any El Nino since 1905
* The rapid rise in ENSO 3.4 ocean temperatures this early in spring historically usually means the El Nino will sustain itself through the summer. The major El Ninos of 1997, 82 and 72 started off slower. A big start doesn't necessarily mean 2015 will be another 1997 or 1982. In fact, the warmth is more centralized. The warmth in '82 and '97 sloshed eastward by summer.
Warmth so far this year has two lobes, one central near dateline and another eastern closer to South America.
* The moderate El Ninos (SST 3/4 between 1.0 and 1.5) in 1987, 72, 65, 57, 30, 25, 23, 18, 05 and 1902 all sustained El Nino status through December per the ENSO 3/4 ocean temperatures.
What does all of this mean for the summer, fall and upcoming winter?
* The next 2-3 months will be critical in determining how this El Nino will impact our (US) weather this summer and especially fall.early winter. The position of the warmth will be a big factor.
* How much cool water near Australia relative to the ENSO 4 and 3/4 region temperatures will be HUGE in driving the westerly wind bursts necessary in sloshing more warmth to the east keeping the El Nino machine going.
Next week, we'll dive more into why the COOL WATER NEAR AUSTRALIA is so critical in the development of El Nino
