Hawaiian Islands Weather details & Aloha paragraphs / March 20-21, 2012

Air Temperatures – The following maximum temperatures were recorded across the state of Hawaii Tuesday:   

Lihue, Kauai –                     79  
Honolulu airport, Oahu –  84  (Record high temperature for this date – 88 / 1998) 
Kaneohe, Oahu –                 M
Molokai airport –                 80
Kahului airport, Maui –      84   (Record high temperature for this date – 90 / 1952)
Kona airport –                    81
Hilo airport, Hawaii –           81

Air Temperatures ranged between these warmest and coolest spots near sea level – and on the highest mountain tops…as of 5pm Tuesday evening:

Kahului, Maui – 80
Princeville, Kauai – 75

Haleakala Crater –  43 (near 10,000 feet on Maui)
Mauna Kea –         43 (near 13,800 feet on the Big Island)

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. Here's the Haleakala Crater webcam on Maui…although this webcam is often not working correctly.

 Aloha Paragraphs

Today was the first full day of Spring 2012

Brief period of volcanic haze now locally…fading soon

As this weather map shows, we have a near 1026 millibar high pressure system to the northeast.  At the same time, we have a deep storm low pressure system far northeast, with its associated cold front extending far southwest from its center, to a low pressure system to the west of Kauai. Our winds will become strengthening trade winds Wednesday through the rest of the week.

The following numbers represent the strongest wind gusts (mph), along with directions Tuesday evening:

14                 Princeville, Kauai – ENE
21                 Kalaeloa, Oahu – SE
07                 Molokai – NE
29                 Kahoolawe – ESE
27                 Kapalua, Maui – NE
10                 Lanai – WNW
24                 South Point, Big Island – NE

We can use the following links to see what’s going on in our area of the north central Pacific Ocean Tuesday evening.  Looking at this NOAA satellite picture we see scattered low clouds over the ocean, although at a minimum upstream at the time of this writing…and mostly over the ocean to the west and southwest of the islands. The mountains had some cloud cover over them this evening in places too. We can use this looping satellite image to see an upper level low pressure system, with its associated trough/front over the ocean to our southwest through northwest…with heavy weather out that way.  Checking out this looping radar image we see just a few showers being carried along over the ocean by the returning trade winds. There were a few showers near Kauai and Oahu that were locally heavier at the time of this writing.

Here are the 24-hour precipitation totals (inches) for each of the islands as of Tuesday evening:
 
0.50               Mount Waialeale, Kauai
0.05               St. Stephens, Oahu
0.00               Molokai
0.00               Kahoolawe
0.00               Maui
0.14               Kealakomo, Big Island  

Sunset Commentary:  Our local winds will increase in strength Wednesday into the weekend. These stronger and gusty trade winds will continue through the rest of this week…right on into next week. At the moment, we have no marine wind advisories active, although as the trade winds rebound during the next 12-18 hours, we'll see small craft wind advisories going up in our windiest coastal and channel waters around the state. These will likely remain in force through most of the rest of the week…if not right on into early next week.

As the aforementioned stronger trade winds arrive soon, the windward sides will turn more showery…with some of these showers being carried over into the leeward sides locally. An upper level trough of low pressure will edge near the islands Friday into Saturday, likely increasing our showers further then. The showers Friday and Saturday may become quite heavy, at least locally, as an upper level low pressure system will enhance them then. As we push into the second half of the weekend, on into early next week, drier weather should return.

Here in Kula, Maui at 540pm Tuesday evening, our skies were partly to mostly cloudy, with light volcanic haze (vog)…and an air temperature of 67.1F degrees. As noted above, our winds will be picking up as we move into Wednesday, and then persist well into the future. This is a classic response to the spring season here in the tropics, which happens to be right on schedule…given that this has been the first full day of our spring season. Meanwhile, as the trade winds surge, they will carry moisture our way, especially along our north and east facing coasts and slopes…known of course as our windward sides. There will be some of these showers transported over into the south and west leeward sides with time too, on the gusty trades. It appears that the Friday and Saturday time frame will have the best chance of seeing the most widespread showers, and some of those will be locally heavy too. ~~~ I'll be back early Wednesday morning with your next new sunrise commentary, I hope you have a great Tuesday night wherever you're spending it! Aloha for now…Glenn.

Extra: This looping satellite image shows the upper area of low pressure out over the ocean to our west…with its associated clouds pushing in our direction.

Interesting: During the Pliocene epoch (5.3 to 2.6 million years ago) climate became cooler and drier, and seasonal, similar to modern climates. The global average temperature in the mid-Pliocene was 2—3 °C higher than today, global sea level 80 feet higher and the northern hemisphere ice sheet was ephemeral before the onset of extensive glaciation over Greenland that occurred in the late Pliocene around 3 million years ago.

Scientists are looking at what climate conditions were like 3.3 to 3 million years ago, during a geologic period known as the Pliocene, and they are confident in the accuracy of their data. The Pliocene is the most recent period of sustained global warmth similar to what is projected for the 21st century.

Climate during this time period offers one of the closest analogs to estimate future climate conditions. The USGS is leading research to reconstruct Pliocene ocean temperatures primarily using fossils contained in sediments from that time period.

"Confidence in data, as discussed in this paper, refers to the overall quality of our Pliocene temperature estimates," said USGS scientist Marci Robinson. "For each temperature estimate, we looked at factors such as the abundance of fossils, the number of samples analyzed, fossil preservation, and the techniques used for analysis."

Scientists from around the world are using the Pliocene reconstructions to compare climate model simulations from fourteen general circulation models. This is an international effort with models developed by the United States, Japan, France, United Kingdom, China, Germany and Norway.

In this study, published in the journal Nature Climate Change, an initial comparison was made between four existing models. Conclusions showed that the models are close in agreement with each other and USGS data, except in the North Atlantic where modeled temperatures differ slightly from the Pliocene data and from each other.

"The processes that impact North Atlantic climate are complex, and we have analyzed many sites in the area," said Dowsett. "Based on this study, we have a high degree of confidence in our North Atlantic data, and we will wait to see how the rest of the models compare and plan future research to better understand the complexities."

Processes that influence North Atlantic Ocean temperatures include ocean circulation, the shape and characteristics of the seafloor, and concentrations of atmospheric CO2 and other trace gases. The Earth's orbit is another factor to consider because it affects the amount of sunlight and, therefore, heat that reaches the Earth's surface.

This Pliocene climate data reconstruction will be useful in predicting which climate model will best represent the future. Carbon dioxide concentration during the mid Pliocene has been estimated at around 400 ppmv. Several mechanisms have been proposed to explain global cooling the end of the Pliocene and the onset of extensive northern hemisphere glaciation.

They are:

Panama seaway closure due to salinity contrast between the Atlantic and the Pacific Oceans.

Collapse of permanent El Niño

Uplift of the Rocky mountains and Greenland west coast

Research on the mid-Pliocene constitutes the most comprehensive global reconstruction for any past warm period.

Interesting2: The history of a changing climate has been officially re-written following the release of new data from Russia and bases within the Arctic Circle. Scientists have now calculated that 2010 has overtaken 1998 to now be the warmest year on record, followed in second place by 2005 as 1998 is pushed into third place.

The recalculation of the annual global mean temperature records follows the release of weather data from more than 600 locations around the Arctic Circle. The dataset is compiled by the Met Office and the University of East Anglia's Climatic Research Unit, who today announced the update.

Compiled from temperature observations obtained over land and sea, HadCRUT is used as a basis for a global temperature record going back to 1850. The latest version of the dataset, called HadCRUT4, includes the newly available data, which now contains information from the All Russian Research Institute adding more records from the sparsely observed northern higher latitude region.

Differences in the way sea surface temperature observations have been collected have been taken account of and the new version also provides much more detail on uncertainty. Colin Morice, Climate Monitoring Research Scientist at the Met Office said: "The new study brings together our latest and most comprehensive databases of land and marine temperature observations, along with recent advances in our understanding of how measurements were made at sea.

These have been combined to give us a clearer picture of what the historical data can tell us about global climate change over the past 161 years. "Updates have resulted in some changes to individual years in the nominal global mean temperature record, but have not changed the overall warming signal of about 0.75 °C since 1900."

One of the key reasons for slight changes to mean temperature for later years in HadCRUT4 is the inclusion of much more data from the Arctic, an area which is warming faster than other parts of the world. Phil Jones, Director of the Climatic Research Unit, said: "HadCRUT is underpinned by observations and we've previously been clear it may not be fully capturing changes in the Arctic because we have had so little data from the area.

"For the latest version we have included observations from more than 400 stations across the Arctic, Russia and Canada. This has led to better representation of what's going on in the large geographical region." Another change relates to dealing with the different ways sea-surface temperatures have been measured.

This has had an effect on some years further back in the record, particularly in the mid 20th century. Peter Stott, Head of Climate Monitoring and Attribution at the Met Office, said: "An example of this is the rapid changes in the kinds of measurements we see in the digital archives around the Second World War.

Some sea surface temperature observations were taken from buckets hauled on board ships and others were made in the engine rooms. "Research has shown readings from buckets were generally cooler so when the database changes from one source to another you see artificial jumps in the raw data.

We've quantified these effects and corrected for them providing a clearer view of the evolution of global temperatures."