What does a Monster El Nino look like? In two words — climate change. And by the end of August climate change’s Monster El Nino may have spawned two strong tropical cyclones and hurled their powerful remnant systems into the Arctic.
The 2015 Monster
The Equatorial Pacific is cracking wide open. Heat, at near new records for August, is oozing out. In the Nino 3.4 zone last week, the heat bleed hit a new intensity of + 2 degrees Celsius above average. That puts our current El Nino easily in the running for one of the top three strongest. And the warming there is expected to continue through at least October — possibly setting up conditions in which the 2014-2016 El Nino is the most intense and perhaps longest-running such event ever seen.
(Our Monster El Nino and three hot blobs — one off California, one off the Pacific Northwest, and one in the Bering and Chukchi — just keep getting hotter and hotter. The extremity of heat covering this section of the Pacific Ocean is simply extraordinary. And the fact that it keeps building may have some serious impacts on Pacific, Arctic, and North American weather patterns. Image source: Earth Nullschool.)
Unlike typical El Ninos, the high heat anomalies are not isolated to a band along the Equator. They extend upward across a vast pool that encompasses practically all of the Northeastern and North-Central Pacific. All of the Bering Sea and a chunk of the Arctic Ocean as well. It’s as if the typical El Nino heat has developed a great chimney that runs over thousands of miles from Equator to Arctic. One that encompasses millions of square miles of much warmer than normal ocean surface. An entire zone that, for the ocean, is a blistering 1-5 degrees Celsius hotter than ‘normal.’
The Warming World’s Intense El Ninos’ Dance With Polar Amplification
Scientists have long warned us about this. Warned us that increasing global temperatures through ongoing fossil fuel burning could greatly amplify the intensity and the frequency of strong El Nino events. A recent paper published in Nature has continued this line of research finding that, under human-forced global warming, the frequency of strong El Ninos is doubled. And, right on queue, the 2014-2016 El Nino is shaping up to be one of the nastiest, if not the nastiest such event we’ve yet experienced.
But it’s not just a question of the intensity of heat boiling out of the Equatorial Pacific. It’s also a question of how a strong El Nino behaves in a world that has been forced to warm by 1 degree Celsius. According to Dr. Jennifer Francis, a significant portion of that extra heat has tended to focus in the Arctic. And this extra Arctic heat has, among other things, gone to work weakening the Jet Stream. In some regions, as we see today over the entire Northeastern Pacific, the tendency has been for powerful high amplitude ridges to form. The ridges often extend all the way into the Arctic — developing pathways for yet more heat to hit the high polar zones.
Like El Nino, the ridge over the Northeastern Pacific is involved in an ocean-atmosphere dance. It’s a dance that includes widespread and abnormally warm water (see hot blob strengthens). And it’s a dance that includes the powerful impact of a Monster El Nino stalking the equatorial zones.
El Nino Hurls Twin Typhoons at the Arctic
Last week, this atmospheric dance included the formation of two tropical cyclones. Feeding off the powerful convection rising up over the Equatorial Pacific, these massive cyclones gathered intensity from the easterlies rushing in to feed the El Nino. They steamed north and westward. By today, Typhoon Goni was threatening the Philippines and Taiwan with 125 mph sustained winds. Meanwhile, Super Typhoon Atsani’s 150 mph sustained winds were tearing through Pacific Ocean waters east of Guam.
(GFS model forecast graphically displayed by Earth Nullschool finds typhoons Goni and Atsani running into wall of the Ridiculously Resilient Ridge by Tuesday. It’s an atmospheric heat bleed from El Nino to Arctic that, according to long range forecasts, has a risk of carrying these strong storms with it. Image source: Earth Nullschool.)
Over the next few days, the typhoons are expected to turn north and eastward. Goni is predicted to skirt the Philippines, Taiwan and Japan. Atsani is expected to remain over open waters to the east of Japan. Both are heading toward the hot, northward moving airs on the backside of the Ridiculously Resilient Ridge.
Currently, the Ridge is positioned over the Northeastern Pacific Ocean hot pool just south and east of the Aleutians. It’s a strong and very deep high pressure system that’s expected to maintain in the range of 1035 to 1040 mb over the coming days. It’s dredging up the hot El Nino airs of the Equatorial Pacific and flinging them all the way to the Arctic Ocean.
Atsani is expected to plow into the back of this atmospheric wall of hot airs and to then follow the warm flow northward — approaching the Bering Sea edge by next Thursday as a powerful 960 to 970 mb extra-tropical low with Goni’s remnants following in its wake.
(Forecast sea level pressure map for Thursday, August 27th show Atsani’s powerful remnants on a track for the Bering Sea and Alaska or the Arctic Ocean. Image source: Climate Reanalyzer.)
If Atsani’s remnants enter the Bering as predicted, it will then either track through Alaska or enter the southern Chukchi and Beaufort Seas. At that point, the strength and disposition of the Arctic high will determine its final path. If the high recedes closer to Greenland and the Canadian Archipelago, Atsani’s extratropical system could be projected into the Arctic Ocean proper as a late season cyclone threatening the sea ice. If the Arctic high is more centrally located, Atsani’s remnants would plow down into the facing trough over Western and Central Canada — bringing with it some very stormy weather.
A Very Odd Storm Track
As with last week, we continue to see this odd tendency for a storm track to develop from the Western Pacific through to the Bering Sea, Alaska, and the Arctic itself. It’s a teleconnection-driven atmospheric dance between a powerful summer El Nino, the hot blob of water over the Northeastern Pacific, and the Ridiculously Resilient Ridge riding over top. With such a pattern so firmly entrenched, there’s a risk that this storm track will maintain well into Fall and, perhaps, persist into Winter with Alaska as the destination for Pacific storms. Under such a pattern there is little hope for drought-busting weather to reach California. Which would mean a continuation of terribly dry conditions there unless our Monster El Nino can somehow squash the extraordinarily dogged RRR.
Meanwhile, for the Arctic, the risk of powerful storms plowing through weak, late season ice is looking a little bit less like an outlier event and more and more like a possibility for end August. So we’ll have to keep a close watch on Atsani, Goni, the RRR and the Arctic High.
Links:
Frequency of Strong El Ninos Doubles Under Human Heat Forcing
Wrecked Pacific Storm Track Now Runs from Equator to Arctic Ocean
robertscribbler 