fuel for El Nino’s fire and a record hot 2015 on the way…
week, a set of climate models predicted the emergence of a large and
moderately strong westerly wind burst running against the trades
associated with an eastward propagating cloudy and rainy phase of
And, over the past few days a moderate strength, but very
wide-ranging, westerly wind pattern appeared.
strengthening westerly wind burst over the Western Equatorial Pacific
could produce a third warm Kelvin Wave and further heighten an El
Nino that already has a potential to be very intense come Fall. Image
20 to 35 mile per hour westerly winds are prevalent along a 2,500
mile stretch of ocean running from just east of the Philippines,
across an equatorial zone just north of New Guinea, and on eastward
for hundreds more miles in the direction of the Date Line. The winds
are associated with numerous low pressure systems developing both
north and south of the Equator — their cyclonic wind patterns
joining in a daisy chain like feature to drive a large synoptic
westerly wind back-burst (WWB).
the next few days, winds within the zone are predicted to strengthen
to near gale force intensity. But it’s the size of the zone that
may have the greatest impact.
long-fetch westerlies in this region of the world have a tendency to
push warm surface waters, now topping off at 31 degrees Celsius (and
1-2 C above the already hotter than normal 1979 to 2000 average),
downward and eastward. This heat pump action generates what, in
meteorological parlance, are known as warm Kelvin Waves. And warm
Kelvin Waves are high energy fuel for strengthening El Ninos.
water propagation through the upper 300 meters of the central and
eastern Equatorial Pacific serves as oceanic fuel for El Nino events.
In the above graph by NOAA, not one but two warm Kelvin Waves are
indicated — one peaking during April and May, and a second ongoing
now. Will a significant westerly wind burst, now lighting off in the
Western Pacific, generate a third warm Kelvin Wave by August? Image
Climate Prediction Center.)
in the Central Pacific, anomalous warm sea surface temperatures were
continuing to build. By mid-May, Central Pacific sea surface
temperatures exceeded the moderate El Nino threshold of 1 C above
average. By Monday, June 22, NOAA’s
weekly El Nino statement had
indicated that the Central Pacific region had warmed to a 1.4 degree
Celsius positive anomaly. A level just 0.1 C short of strong El Nino
a third significant Westerly Wind Burst on top of an already warming
Equatorial Pacific throws yet one more variable into the dynamic El
A variable that could heighten the already strong
potential for a major El Nino event late this Summer through to Fall.
And one that could further heighten extreme global record hot
temperatures during 2015. For the late June WWB is likely to produce
an extraordinary third Warm Kelvin Wave, giving the currently
strengthening El Nino yet one more shove toward increasingly extreme