Thursday 9 July 2015

The Screaming Hot Pacific

Screaming Hot Pacific A Sea of Storms as 2015 El Nino Breaks Records For Spring Intensity


8 July, 2015
The currently strengthening El Nino enters the record books for Spring heat even as it throws off an extreme surge of tropical cyclone activity in the Western Pacific…
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For a swath of ocean from the Date Line to 120 degrees West Longitude (Nino 3.4) it’s been a rather hot spring. Sea surface temperatures for the benchmark zone hit 4th highest in the regional climate measure (starting in 1950) for the period. With almost every climate model predicting continued El Nino strengthening through Fall, this early benchmark would be some cause for concern. Averages for the region hit a positive anomaly of +0.85 C, just behind record holder 1992 at +1 C. But even more disconcerting was the extreme warming through another marker zone just to the west. A heat build-up which shattered all previous seasonal records for the period. For the Nino 4 region stretching from 160 East to 150 West Longitude, the April to June time frame for 2015 was the hottest ever seen:

Nino 4
(Nino 4 hits new record hot temperatures for Spring of 2015, crushing all previous record holders. Data Source: NOAA El Nino Monitoring. Image source: Eric Blake.)

Hotter, in fact, by a long shot — crushing the previous all-time positive anomaly record of +0.65 as it surged to +1 C above the regional average. For an El Nino that is still ramping up against the climatological trend for Summer to Fall cooling, these early markers may well serve as an indicator for future intensity.
The new record also came before the most recent surge in thunderstorm activity over the Western Pacific set off a major burst of westerly winds. A powerful atmospheric back-blast that will likely generate a third warm Kelvin Wave and further tip the Eastern Pacific into ever more extreme high temperature values. An extraordinary burst of storms in its own right powered by record levels of moisture bleeding off this zone in the Pacific and an amazing temperature gradient that is now starting to form from the higher temperature deltas along and near the Equator.
West Pacific El Nino Sea of Storms
(West Pacific a sea of storms on July 8 as El Nino continues to show signs of intensification. Image source: LANCE MODIS.)

By earlier this week these storms had coalesced into three powerful tropical cyclones — Linfa, Chan-hom, and Nangka. Two of which — Chan-hom and Nangka — now rate as super typhoons on the Hong Kong intensity scale (100 knots or greater maximum sustained wind speed).
Chan-Hom is predicted to plow into the China coastline near Shanghai over the next 36-48 hours as a 115 knot (132 mph) major cyclone. On the satellite shot, this beast clearly displays a substantial footprint. Joint Typhoon Warning Center reports show an extensive tropical storm force wind field stretching out up to 145 nautical miles from the storm’s center with hurricane force winds extending out 35 nautical miles. Linfa is also predicted to interact with land over the next two days — skirting Taiwan as a moderate strength tropical storm before retrograding southward into the Northern Philippines. Nangka is expected to skirt Guam, then remain over open ocean through the 13th of July.

All together, these ocean heat and moisture fueled storms represent an extraordinary accumulated cyclone energy anomaly for the region. One that is forecast to hit nearly nine times the mean value for the Western Pacific for the seven day period of July 6 through July 12. Yet another off-the charts weather reading coming from the still strengthening and global warming amplified 2015 El Nino:
Cyclone energy
(ECMWF forecast model shows extreme cyclone accumulated energy potentials for Central and Western Pacific. Image source: ECMWF.)

In context, we can add this intense Western Pacific cyclonic outburst to a long list of related 2015 El Nino and global warming influenced events (more on this in a future post). These include widespread South American drought, the Ridiculously Resilient Ridge and associated North American Wildfires, Western North American droughts, Arctic Sea Ice impacts, The Central US Floods of May and June, a delayed Monsoon and deadly heatwave switching to extreme floods in India, a mass casualty heatwave in Pakistan, and floods in Thailand and China (among others).
By later this Fall, if the strong to monstrously strong El Nino predicted in the model runs does emerge, other significant El Nino related impacts may manifest due to a related strengthening of the Pacific storm track. As a result, we could see a switch from epic drought to epic deluge for the US West Coast. It’s a narrative that has become all too common as human forced global warming in the range of 0.8 to 1 C above 1880s values continues to enable far more extreme hydrological weather events than we are used to (drought and flood). El Nino’s hand in increasing evaporation over the Equatorial Pacific, when combined with the broader impact of human forced warming, is one that generates a still higher risk for these kinds of extreme events. And with El Nino forecast to be strong to absolutely monstrous, it is highly advised that US West Coasters keep a weather watch out for the coming Fall.
Links:
NOAA El Nino Monitoring (Please support publicly funded, non special interest based science.)
Hat tip to Colorado Bob
Hat tip to climatehawk


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