Hawaiian Islands Weather Details & Aloha Paragraphs / July 15-16, 2015

Air Temperatures – The following maximum temperatures (F) were recorded across the state of Hawaii Wednesday…along with the minimums Wednesday:

85 – 76  Lihue, Kauai
90 – 77  Honolulu, Oahu – record high for Wednesday was 94…back in 1995
86 – 74  Molokai
89 – 74  Kahului, Maui 
88 – 76  Kailua Kona
87 – 72  Hilo, Hawaii

Here are the latest 24-hour precipitation totals (inches) for each of the islands, as of Wednesday evening:

0.84  Mount Waialeale, Kauai
0.60  Oahu Forest NWR, Oahu
0.15  Puu Alii, Molokai
0.00  Lanai
0.00  Kahoolawe
0.26  Hana AP, Maui
0.67  Waiakea Uka, Big Island

The following numbers represent the strongest wind gusts (mph)…as of Wednesday evening:

20  Waimea Heights, Kauai – SE
31  Kuaokala, Oahu – ENE
28  Molokai – NE
28  Lanai – NE
31  Kahoolawe – NE
31  Maalaea Bay, Maui – NNW
28  Kealakomo, Big Island – E

Hawaii’s Mountains – Here’s a link to the live web cam on the summit of near 13,800 foot Mauna Kea on the Big Island of Hawaii. This web cam is available during the daylight hours here in the islands…and when there’s a big moon shining down during the night at times. Plus, during the nights you will be able to see stars, and the sunrise and sunset too… depending upon weather conditions.

Aloha Paragraphs

There are a couple of tropical disturbances here in the
central Pacific – in addition to tropical storm Enrique
well to our east, and hurricane Dolores close to
Mexico…both in the eastern Pacific
more information below

There’s the leading edge of a showery low cloud area
impacting the islands, which broke way from TS Enrique
further to our east…along with areas of thunderstorms
far west and south of the state – Looping version

Look for increasing showers, the bulk of which will fall
along our windward sides…although not exclusively
Looping version

Showers mostly over the ocean, arriving over the
islands locally…some quite generous
looping radar image

~~~ Hawaii Weather Narrative ~~~

The trade winds will continue to blow through the rest of this week…into the early part of next week. Here’s the latest weather map, showing the Hawaiian Islands, and the rest of the North Pacific Ocean, along with a real-time wind profiler of the central Pacific. We find a near 1032 millibar high pressure system to the northeast of the state…moving northeast. Meanwhile, there are tropical systems/troughs west, southwest, south and east of Hawaii…moving more or less westward. The trade winds are now expected to continue unabated through the next week. 

Increasing windward showers through the next couple of days…some elsewhere at times. The forecast continues to suggest we’ll see an increase in showers tonight through the Saturday morning time frame…along with a rise in humidity levels. These showers will arrive over Maui County and the Big Island first, then sliding up the chain toward Oahu and Kauai. The models go on to point out drier weather later Saturday into early next week. I’ll be back with more updates on all of the above and below, I hope you have a great Wednesday night wherever you’re spending it! Aloha for now…Glenn.

Here on Maui…it’s 535am Wednesday morning, with clear to partly cloudy conditions over the the island. The air temperature here in Kula, at my upcountry weather tower was 58.9 degrees, while it was 75 down at the Kahului airport, 72 out in Hana…and 45 up at the summit of the Haleakala Crater at near the same time./ It’s a gorgeous day here on Maui, and I’m finding it interesting eyeballing that next slug of moisture to our east…taking aim on the windward sides of both Maui and the Big Island tonight.

– It’s just now 5pm here in Kula, under partly cloudy skies, and light trade wind breezes. Looking around the rest of the island of Maui, I see lots of sunshine beaming down, with areas of low clouds mixed in here and there. The beaches seem to have the fewest clouds at the time of this writing. As noted above, look for increasing clouds and showers, along with high humidity tonight into Saturday, mostly along the windward sides…but not exclusively.

World-wide tropical cyclone activity:

>>> Atlantic Ocean:  There are no active tropical cyclones

>>> Caribbean Sea: There are no active tropical cyclones

>>> Gulf of Mexico: There are no active tropical cyclones

Here’s a satellite image of the Atlantic Ocean

Here’s a satellite image of the Caribbean Sea…and the Gulf of Mexico

Tropical cyclone formation is not expected during the next 5 days over the Gulf of Mexico, Caribbean Sea or Atlantic Ocean

Here’s the link to the National Hurricane Center (NHC)

>>> Eastern Pacific:

Hurricane 05E (Dolores) at category 3 strength…remains active in the eastern Pacific Ocean, located 240 miles south-southwest of Cabo San Lucas, Mexico. Here’s a graphical track map of this system.

Here’s what the hurricane models are showing for this hurricane…along with a satellite image

Tropical Storm 06E (Enrique) remains active in the eastern Pacific Ocean, located 1655 miles west of the southern tip of Baja California. Here’s a graphical track map of system.

Here’s what the hurricane models are showing for this tropical storm…along with a satellite image

Here’s a wide satellite image that covers the entire area between Mexico, out through the central Pacific…to the International Dateline.

Here’s the link to the National Hurricane Center (NHC)

>>> Central Pacific:  There are no active tropical cyclones

1.)  An area of low pressure associated with former tropical storm Iune, located more than 1100 miles southwest of Honolulu , Hawaii, has been moving steadily west. The system continues to generate disorganized showers and thunderstorms periodically. However, environmental conditions will likely impede further development over the next couple of days.

* Formation chance through 48 hours, low…10 percent

Here’s a satellite image of this area of disturbed weather

Here’s a link to the Central Pacific Hurricane Center (CPHC)

>>> Northwest Pacific Ocean:

Typhoon 11W (Nangka) remains active in the northwest Pacific…located about 142 NM southeast of Iwakuni, Japan. Here’s the JTWC graphical track map, along with a satellite image. Here’s what the computer model is showing.

Tropical storm 1C (Halola) remains active…located about 148 NM west-southwest of Wake Island. Here’s the JTWC graphical track map, along with a satellite image of this gradually strengthening tropical cyclone. Here’s what the computer models are showing.

Here’s the JTWC graphical track map, along with a satellite image of this gradually strengthening tropical cyclone.

>>> South Pacific Ocean: There are no active tropical cyclones

>>> North and South Indian Oceans: There are no active tropical cyclones

Here’s a link to the Joint Typhoon Warning Center (JTWC)

Interesting:  How Climate Change will Affect Air Travel – Global air travel contributes around 3.5 percent of the greenhouse forcing driving anthropogenic climate change, according to the International Panel on Climate Change (IPCC). But what impact does a warming planet have on air travel and how might that, in turn, affect the rate of warming itself?

A new study by researchers at the Woods Hole Oceanographic Institution and University of Wisconsin Madison found a connection between climate and airline flight times, suggesting a feedback loop could exist between the carbon emissions of airplanes and our changing climate. The study was published today in Nature Climate Change.

“Upper level wind circulation patterns are the major factor in influencing flight times,” says lead author Kris Karnauskas, an associate scientist in WHOI’s Geology and Geophysics Department. “Longer flight times mean increased fuel consumption by airliners. The consequent additional input of CO2 into the atmosphere can feed back and amplify emerging changes in atmospheric circulation.”

The study began when co-author Hannah Barkley, a doctoral student in the MIT-WHOI Joint Program in Oceanography, asked Karnauskas a deceptively simple question. Barkley had noticed a direct flight she took from Honolulu back to the east coast—a route she has flown many times as field scientist—took far less time than expected, and she asked Karnauskas why that might be.

“The first thing that came to mind was, what did the flight-level winds look like that day,” Karnauskas says.

They quickly queried a database of the winds on a NOAA website, selecting for the altitude jets fly at and plugging in the date of Barkley’s flight, and saw that the jet stream that day was extra fast.

“There was just a big swath of extra-fast westerly winds stretching from Honolulu, Hawaii, to Newark,” says Karnauskas. “It was just serendipitous, as if she was part of some kind of golden mileage club where the atmosphere just opens up for you.”

The finding piqued their curiosity about just how unusual Barkley’s experience was, and the simple question led to a study of decades worth of data on flights between Honolulu and the North American West Coast (Los Angeles, San Francisco, and Seattle) by four different air carriers.

Through a database maintained by the Department of Transportation they were able to download departure and arrival data by each airline and the routes traveled—for every single flight that has occurred over the past 20 years. Because the upper level winds blow from west to east, the eastbound leg of a roundtrip flight is generally faster than the westbound leg. After quality controlling the data, Karnauskas plotted the differences in flight times for eastbound and westbound flights and noticed that regardless of the airline carrier, the difference for all the carriers looked the same, over the past 20 years.

“Whatever was causing these flights to change their duration, was the exact same thing, and it wasn’t part of the airline’s decision-making process,” Karnauskas says. The hypothesis was born that climate variability (not just day-to-day weather) determines flight times.

He began digging into massive volumes of atmospheric data to assemble a “composite” snapshot of what the atmosphere looks like on days where the difference in flight times is large, versus small. When he overlaid the plots of the airlines’s differences in flight times with graphs of wind variability at climatic time scales, Karnauskas says he “was pretty blown away.” The plots were virtually identical.

Even after smoothing out the seasonal differences (the jet stream is always a little stronger in winter and weaker in summer), leaving him with the year-to-year variability, the match held up almost perfectly. Flight-level wind speed explained 91 percent of the year–to–year variance. The result also pointed toward the influence of El Niño – Southern Oscillation (ENSO) – a phenomenon Karnauskas has studied extensively.

As the temperature of the equatorial Pacific Ocean rises and falls, like a pebble in a pond, atmospheric waves are set off toward the higher latitudes of both hemispheres, where they change circulation patterns.

“I came into this study, thinking this is going to be a weird junket that is totally unrelated to anything I do, but it really led me back to El Niño, which is what I do.”

Karnauskas found that just by looking at the state of the tropical Pacific Ocean, he could predict what the airlines’ difference in flight times had been. For this so-called hindcast, “we’re talking about anomalies happening down at the equator that are affecting the atmosphere in such a spatially broad way, that it’s probably influencing flights all around the world.”

Their analysis also determined that the difference in flight times between eastbound and westbound flights on any given route didn’t cancel each other out; rather there was a residual. In other words, when an eastbound flight became 10 minutes shorter, the corresponding westbound flight became 11 minutes longer.

According to Karnauskas, it took some “obsessive drilling into the data to find that residual, and at face value it seems very minor.” The net additional flying time for a pair of eastbound and westbound flights between, for example, Honolulu and LA is only a couple minutes for every 10 mph speedup of the prevailing wind.But, he says, “the wind really fluctuates by about 40 mph, so multiply those couple of minutes by each flight per day, by each carrier, by each route, and that residual adds up quickly. We’re talking millions of dollars in changes in fuel costs.”

Once the researchers had proven that the atmospheric circulation affects how long planes are in the air, they began to wonder about the impact climate change would have on the airline industry. 

According to the study, there are approximately 30,000 commercial flights per day in the U.S. If the total round–trip flying time changed by an average of one minute, the amount of time commercial jets would spend in the air would change by approximately 300,000 hours per year. This translates to approximately 1 billion gallons of jet fuel, which is approximately $3 billion in fuel cost, and 10 billion kilograms of CO₂ emitted, per year.

“We already know that as you add CO₂ to the atmosphere and the global mean temperature rises, the wind circulation changes as well—and in less obvious ways,” says Karnauskas.

Based on what they had learned about the airlines’ residual flight times, the researchers explored how climate models predict the atmospheric circulation to change and to make some estimates of how much more CO₂ will be emitted by the airline industry in the face of those changes. Currently, global climate model projections do incorporate projected emissions from the global aviation industry, but if atmospheric circulation changes, those initial assumptions would miss the potential feedback.

Karnauskas believes this information could be useful for the airline industry to more efficiently plan for future fuel costs, reallocate fuel resources, refine the predicted flight durations for their customers, and better manage all the inconveniences and manpower related to flight delays.

While this study focuses on a very small subset of the total global airline traffic, Karnauskas has plans to expand this study to include all global flights – a massive undertaking. To work with such large datasets, Karnauskas has been granted access to Azure, a powerful cluster of networked supercomputers operated by Microsoft, under a special research grant jointly offered between Microsoft Research and the White House Climate Data Initiative.

In reflecting on the findings of this project and the simple question Barkley had initially asked, Karnauskas says one of the biggest surprises is that the airline industry doesn’t seem to be aware of the flight time patterns beyond the day-to-day.

“The airline industry keeps a close eye on the day-to-day weather patterns, but they don’t seem to be addressing cycles occurring over a year or longer,” he says. “They never say, ‘Dear customer, there’s an El Niño brewing, so we’ve lengthened your estimated flight duration by 30 minutes.’ I’ve never seen that.”