Monster El Nino Hurls Record Barrage of Hurricanes at Hot Blob, Sets Sights on Drought-Ravaged California
1
September, 2015
The
Hot Blob in the Northeastern Pacific held its own for quite some
time. But it now faces the assault of a barrage of tropical cyclones
spat from the maw of a monster El Nino that is now tracking its way
toward the strongest such event on record. If this keeps up, the
Ridiculously Resilient Ridge warding storms off the US West Coast
will be besieged by increasingly powerful cyclonic systems. The Ekman
pumping from such storms will cool the ocean surface at its periphery
and expanding toward its heart, eventually crushing the ocean impetus
for ridge formation. The continuation of such a pattern could then
kick Bjerknes feedback into higher gear — opening wide the door for
powerful storms striking the US West Coast this Fall and Winter.
*
* * * *
A
Record-Shattering Barrage of Pacific Cyclones
Late
during the evening of August 29th of 2015 something odd happened. For
the first time in the history of modern meteorological record
keeping, three category four typhoons simultaneously churned their
way northward through the Pacific Ocean.
These massive and powerful storms, just one category shy of the
strongest typhoons we have a measure for, were hurled out of a region
of extremely hot sea surface temperatures near the Equator. A zone,
that for late August was also hitting record hot levels amidst a
building Monster El Nino. And never before in modern memory had so
many storms of such high intensity filled Pacific Ocean waters.
(Signs
that powerful Fall and Winter storms are coming for the US West
Coast? From north to south, strong cyclones are starting to put the
squeeze on the Ridiculously Resilient Ridge. The Central and Eastern
Pacific between 10 and 30 North, in particular, shows an eye-widening
number of tropical cyclones. As of Tuesday, September 1, a whopping
four tropical systems were churning northward out of an extremely hot
El Nino zone. Image source: Earth
Nullschool.)
By
today, the furthest northward cyclones had vented their fury and
dropped in intensity. Meanwhile, a fourth storm — tropical
depression 14-E —
was in the process of exploding over the very hot waters of the
Eastern Pacific. It’s an unprecedented number of storms flowing out
of what may become the strongest El Nino on record as part of a
powerful ocean-atmospheric feedback.
Strong
Bjerknes Feedback to Crush RRR?
Now,
this strong storm pulse is starting to put the squeeze on the
famed Ridiculously
Resilient Ridge (RRR).
It’s a persistent ridge that for the better part of three years has
turned storms away from the US West Coast — deepening already
prevalent drought conditions over California and threatening water
security across the US West.
But
now the RRR is surrounded by storms. A strong frontal trough runs
from 30 North across the Central Pacific and on up into the Bering
Sea. Another significant late summer low churns off the Pacific
Northwest — running south and east toward Seattle and British
Columbia. And four tropical cyclones push northward into the ridge’s
southern boundary. It’s a full court atmospheric press. One that,
through the mechanism of Ekman pumping, will push for the generation
of upwelling and related cooling of the Northeastern Pacific waters
beneath the RRR.
(Sea
surface temperature and atmospheric conditions are beginning to fall
more in line with an El Nino related pattern called Bjerknes
Feedback. Image source: NOAA.)
If
this happens, a good portion of the RRR’s atmospheric inertia will
fail — opening wide the door for a powerful west to east storm
track development fed by heat rising off a Monster El Nino sprawling
over the Equatorial zones. It’s a pattern that’s starting to
look like a rather significant Bjerknes-type
feedback to
a record or near record El Nino. One that may well continue to
develop and grow ever-stormier as Fall progresses.
2015
El Nino Still Heating Up, Expected to Heat Up More
Feeding
the powerful pulse of storms is a still-heating Equatorial Pacific.
As of Monday,NOAA’s
Weekly El Nino Report found
that the critical Nino 3.4 zone had warmed 2.2 degrees Celsius above
average. This warming follows an inexorable three month rise that
began in June and has mostly continued unabated.
Furthermore,
seasonal trends together with the already powerful observed
atmospheric feedbacks would tend to continue to push surface warming
through October and November. So it’s likely that an El Nino that
has already ventured well into monster event range will warm further
over the coming 4-10 weeks — setting the stage for a possible
excession of 1997’s record setting intensity.
(The
2015 El Nino is
starting to look like one of the very intense events some climate
models predicted as an upshot of human-forced global warming.
It’s only early September and Nino 3.4 is already 2.2 C hotter than
average. This Equatorial Pacific region is still heating up as
storm-forced up-welling begins to develop cool regions in the RRR
supporting zones of the Northeastern Pacific Hot Blob. It will take a
boatload of strong storms to crush the RRR, but the still
strengthening monster El Nino to the south keeps firing them
northward. Image source: Earth
Nullschool.)
Model
runs still point toward this possibility with CPC/IRI
convergent and dynamic 3 month average predictions in the range of
2.3 to 2.5 C above average (which
would beat out 1997’s 2.2 C departure). Meanwhile, uncorrected
CFSv2 model runs continue to put the
October, November, December 3 month average prediction in the range
of 2.75 C above baseline.
A level that would basically blow the 1997 El Nino out of the water.
To this point it’s worth re-iterating that weekly sea surface
temperature departures for the Equatorial Pacific are now entering
record setting ranges. Many
analysts, like Weather Underground’s Steve Gregory, expecting these
waters to continue to warm over the coming weeks.
Conditions
in Context: Look Out For Rough Weather Coming to US West Coast
Though
it’s too early to lock in the death of the RRR, conditions are
lining up that will continue to put the squeeze on this persistent
weather pattern. As a result, chances for some very intense storms
beginning to slam into the US West Coast starting during October,
November and December are on the rise. For those looking to a
possible end to the droughts, wildfires and water shortages in the
Western US, this potential change in conditions may be seen as a
relief.
However,
such an extreme switch brings with it the distinct possibility that
storms associated with a potential strongest El Nino on record will
be very disruptive. The droughts and numerous wildfires throughout
the West have established soil conditions that will only enhance
flood related impacts. Powerful rains associated with El Nino will
likely increase erosion and further damage soils in regions already
impacted by the severe droughts, mass tree deaths, and wildfires
related to human forced climate change and fossil fuel burning.
(As
of August 13, 2015, some parts of California were facing a rainfall
deficit of 2 years or more. In order to break the drought, 2015’s
monster El Nino would have to set off severe flood conditions during
Fall and Winter. With the RRR under threat, is California staring
down the barrel of a switch to an equally ridiculous barrage of
storms? Image source:National
Weather Service, Phoenix.)
To
this final point, parts of California are now entering a 2 year
rainfall deficit. A deficit that, in some places, equals 30-40 inches
or more. A monster El Nino crushing the RRR and massively amplifying
the Pacific Ocean storm track and pumping immense volumes of moisture
into the mid-latitudes raises the risk that this much water or more
could be dumped upon parts of California and the US West Coast in
little more than a season. A switch from persistent, crushing drought
to flash flood that could be extraordinarily disruptive.
Links:
Hat
Tip to Ray Duray
(Please
support public, non-special interest based science like the fantastic
El Nino reports provided by NOAA and without which this analysis
would not be possible.)
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