Hawaiian Islands Weather Details & Aloha Paragraphs / June 28-29, 2015

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

84 – 75  Lihue, Kauai
87 – 75  Honolulu, Oahu
87 – 71  Molokai
92 – 68  Kahului, Maui – Tied the all time maximum record for Sunday…set back in 1969
86 – 77  Kailua Kona
88 – 72  Hilo, Hawaii

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

0.48  Mount Waialeale, Kauai
2.12  Moanalua RG, Oahu
0.00  Puu Alii, Molokai
0.00  Lanai
0.00  Kahoolawe
0.00  Maui
0.01  Kiholo RG, Big Island

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

20  Mana, Kauai – NW
23  Kuaokala, Oahu – NNE
18  Molokai – E
20  Lanai – NE
28  Kahoolawe – NE
18  Kapalua, Maui – NE
23  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

Low pressure system with a cold front north of the islands…high
clouds approaching from the southwest

Clouds being carried our way on the trade wind flow,
high cirrus south of the Big Island – Looping version

Some showers over the islands…and over the
nearby ocean – here’s the looping radar image

~~~ Hawaii Weather Narrative ~~~

Trade winds will continue…losing strength into the new 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 moderately strong high pressure systems to the northwest and northeast of the state. At the same time, there’s low pressure systems to the north, and well to the northeast, with associated cold fronts evident to the north of the islands. Our trades will soften some now, with onshore daytime sea breezes, and offshore flowing land breezes during the nights. This somewhat unusual weather situation, caused by the relatively close proximity of the cold fronts to our north, should be fairly short-lived. Climatology would strongly suggest rebounding trade winds by later Tuesday or Wednesday…remaining well established into next weekend and beyond.

As the trade winds weaken some…we’ll see showers popping-up over the islands during the afternoon hours locally. The windward sides will still see a few showers, although not all that many are expected. As the trades remain rather soft into the new week, we’ll see a convective weather pattern continuing. This will manifest as afternoon upcountry clouds leading to localized showers, clearing back during the nights for the most part. Several atmospheric factors may come together…to induce increased shower activity in the Tuesday through Thursday time frame. This potential enhancement to our local showers, should be followed by a more normal passing shower regime along our windward sides. I’ll be back with more updates on all of the above, I hope you have a great Sunday wherever you’re spending it! Aloha for now…Glenn.

Here on Maui…it’s 620am Sunday morning, with mostly clear conditions, along with some relatively light volcanic haze as well. The air temperature here in Kula, at my upcountry weather tower was 55.9 degrees, while it was 69 down at the Kahului airport, 77 out in Hana…and 43 up at the summit of the Haleakala Crater at near the same time. / It’s now getting on to the later morning time frame, with partly to mostly cloudy conditions overhead here in Kula…and clear sunny skies down at the beaches. The light to almost moderately thick volcanic haze is sticking around too.

– It’s now very early Sunday evening, under clouds around the mountains…and sunny skies along the beaches. Looking down into the central valley from up here in Kula, I can still see light to almost moderately thick volcanic haze in our atmosphere.


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: There are no active tropical cyclones

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

No tropical cyclones are expected through the next five days

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

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

Here’s a satellite image with this area marked with an X

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

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

There are three tropical disturbances active in the western Pacific, one with a low chance, and the other two with a medium chance of developing during the next 24 hours. Here’s a Navy satellite image showing these areas.

>>> 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: Beijing growing explosively, impacting weather and climate – A new study by scientists using data from NASA’s QuikScat satellite has demonstrated a novel technique to quantify urban growth based on observed changes in physical infrastructure. The researchers used the technique to study the rapid urban growth in Beijing, China, finding that its physical area quadrupled between 2000 and 2009.

Data from NASA’s QuikScat satellite show the changing extent of Beijing between 2000 and 2009 through changes to its infrastructure. Gray and black indicate buildings, with the tallest and largest buildings in the city’s commercial core appearing lighter gray. Other colors show changes in areas not yet urbanized (for example, clearing land or cutting down trees), with the rate of change indicated by color. Blue-green indicates the least change, yellow-orange more change, and red the greatest change. Image credit: NASA/JPL-Caltech

A team led by Mark Jacobson of Stanford University, Palo Alto, California, and Son Nghiem of NASA’s Jet Propulsion Laboratory, Pasadena, California, used data from QuikScat to measure the extent of infrastructure changes, such as new buildings and roads, in China’s capital. They then quantified how urban growth has changed Beijing’s wind patterns and pollution, using a computer model of climate and air quality developed by Jacobson.

New infrastructure alone — the buildings and roads themselves, not including additional pollution created by the new city dwellers and their vehicles — created a ring of impacts around the older parts of Beijing. The impacts included increasing winter temperatures by about 5 to 7 degrees Fahrenheit (3 to 4 degrees Celsius) and reducing wind speed by about 2 to 7 mph (1 to 3 meters per second), making the city air more stagnant.

“Buildings slow down winds just by blocking the air, and also by creating friction,” Jacobson explained. “You have higher temperatures because covering the soil reduces evaporation, which is a cooling process.” Roads and roofs heat up more during the day than soil or vegetation would because they are drier. The heat and more stagnant air create a cascade of consequences, such as increased ground-level ozone pollution.

Beijing’s official city limits enclose an area larger than the state of Connecticut, but much of that real estate is undeveloped and likely to remain so — nature preserves and rugged mountains, for example. The Chinese capital is far from the only world city whose official area differs from its actual footprint.

“There are so many definitions of urban extent, both legislative and administrative,” Nghiem pointed out. “To learn how physical change affects the environment, you cannot use an arbitrary political definition. The reality is what’s happening on the ground.” The new method allows researchers to pinpoint just that.

Other satellites such as Landsat, operating since 1972, and the Visible Infrared Imaging Radiometer Suite on the Suomi National Polar-orbiting Partnership satellite also track urbanization in various parts of the world. These mostly use visible evidence, such as changes in the extent of city lights or clearing of vegetation, as stand-ins for growth. These measures have recognized limitations, however. For example, city neighborhoods without streetlights may be indistinguishable from the countryside at night. Nghiem’s technique can enhance and complement existing measurements.

Nghiem used advanced data-processing techniques on measurements from NASA’s QuikScat scatterometer, a satellite radar managed by JPL that operated from 1999 to 2009. Like all radars, QuikScat sent pulses of microwaves toward Earth and recorded the waves that bounced back, called backscatter. Nghiem’s technique takes advantage of the fact that human-built structures produce stronger backscatter than soil or vegetation. The more, larger or taller the buildings are, the stronger the backscatter. His data-processing method improves the “focus” of the QuikScat image from a pixel size of about 15 miles (25 kilometers) per side to 0.6 mile (1 kilometer) per side, allowing the researchers to capture detail at the scale of a few city blocks.

Nghiem emphasized that the study set only the lower bounds for the impacts of urbanization on local weather and pollution. “If you were to develop a city that didn’t allow any pollution sources, not even a single gas-powered car, you would still have these bad effects.”