Is it possible to have perfect weather all the time?

Well, Maui comes close, but even paradise has it's flaws. Maui is located at  20.80° N, 156.33° W, amidst the climate zone the tropic of cancer and the northern temperate zone, resulting in fairly consistent temperatures year-round with warm summers and mild “winters”. 

Summer spans from May to September with average highs in the mid-80's and peaking in the high-80's during August and September. “Winter”, or rather the rainy season, begins in October and stretches to April with average high temperatures in the low-80's, however temperatures have been know to fall into the low-60's.

Clouds generally form on the eastern side of the island, and due to that pesky little volcano in the middle of the island adiabatic processes come into play. Orographic lifting occurs where these clouds and warm air masses are forced upslope over Haleakala. As this warm moist air changes elevation and reaches the condensation point, precipitation occurs. As the clouds lose their moisture and dissipate, the dry air descends down the opposite (leeward) side of the mountain and a rain shadow forms, thus cities on the west coast such as Lahaina, Wailea, and Kihei (Kihei holla!) tend to be sunny and dry.

Maui's location leaves the weather heavily influenced by the trade winds, which are easterly winds that occur in the tropics as warm air 'rises' towards the poles, cooling, and subsequently “sinking” back towards equator to be heated again. Average humidity or amount of moisture held in the air in Maui hovers around 70%, peaking in the morning. Rainfall plays a large role in Maui's climate as a whole, and tends to happen frequently but not usually for an extended period of time per storm. Rain is most likely to occur in the morning, and most often during the winter months, or the rainy season. Severe storms, particularly thunderstorms are rare as precipitation is not usually the result of frontal or convergent lifting. 

Annual rainfall averages vary depending on where and at what elevation you are at on the island. Eastern and higher elevation areas such as Hana generally see about 85” of rain per year, exorbitant compared to lower and western regions like Kihei (Kihei holla!) that collect on average only about 8” annually. This past year however, the western/leeward side of the island saw less rainfall than usual, causing a draught. Severe hurricanes rarely hit Maui as the mountainous terrain causes the most sever typhoons to vitiate into tropical storms, yet tsunamis as a result of seismic activity in other areas of the pacific rim are a major concern, and their potential for devastation is monitored closely by the Pacific Tsunami Warning Center.

Water, water, everywhere...

Well duh, it's an island. Maui's humid tropical climate and diverse terrain set the stage for some incredible hydrological features! Ground water, water which moves in the porous space between rocks, is one of Maui's most important resources because it is used for agriculture, drinking, and other industrial needs.

The majority of rainfall returns to the ocean via streams or the atmosphere by evaporation, but some remains trapped in the earth. Beneath the surface, water stays in either the saturated or unsaturated zone. In the unsaturated layer, water and air are caught between the pore spaces in rocks; in contrast the saturated layer contains only water and is refereed to as the water table.

The amount of water Maui's volcanic soil can hold, or its permeability, varies based primarily on the viscosity of the the lava flow and topography. More compact flows which occur as incline decreases generally hold less water resulting in surface water.

Pipiwai Trail

Surface water occurs where the amount of water flow exceeds the ground's ability to absorb it and generally takes the form of streams and ponds. Components of surface water include direct runoff, base flow (where streams meet the water table), excess irrigation, and water returned from bank storage. Streams in Maui can be effluent, meaning the water table facilitates stream flow, or influent meaning they lose water to recharge the aquifer.

Recharge, or the replacement of water reserves in the ground, is particularly important because Maui contains no desalination plants. Recharge occurs as precipitation, runoff, and surface water makes its way to aquifers, the last permeable layer of soil from which water can still be obtained. Aquifers can be unconstrained like the water table, or constrained as in trapped between two impermeable layers such as an artesian aquifer.

Island beginnings

Maui exemplifies many of the geographic features we've talked about so far, beginning with the actual formation of the island. Maui, like all the Hawaiian islands, was formed as a result of a volcano. Haleakala (dormant since 1790) (1) was produced by the Hawaiian hotspot. Because Hawaii is not located on the boundary between tectonic plates, the hotspot is particularly unique. As magma located close to the sea floor rises through a conduit, it cools and layers, resulting in an island. While the hot spot remains stationary, the plate above it moves, resulting in a chain of islands that were carried off the hotspot by top-layer drift. (2)

(4)

Currently the hot spot is facilitating the activity of Kilauea on/under the Big Island, some 113 miles away from Maui's current location.

As the second oldest of the islands it is smaller than the Big Island due to longer drift and therefore longer exposure to erosion and weathering. In addition to mere drift erosion, volcanic activity around the Pacific rim results often in earthquakes and tsunamis, such as the Tsunami that hit South East Asia after Christmas of 2004. Presently Maui is not as susceptible to tsunamis as it once was due to protection from outlying minor islands, however historically Maui had no defense, particularly at the island's creation 1.1 million years ago. (3)

As an extrusive formation Haleakala is a typical shield volcano composing the majority of the island. The particularly fluid magma that resulted from its eruptions traveled farther before cooling, creating a mound that is particularly wide but not necessarily steep (12,000ft elv, 30,183 acres). Basalt, the foundation of the island, is the most common rock type outside the main continents and is rich in oxidized minerals. The mineral grain in basalt is so fine that it cannot be seen by the naked eye, however it is highly porous due to escaping gas as it reaches the surface and cools.

(1)http://www.soest.hawaii.edu/GG/HCV/haw_formation.html

(2)http://pubs.usgs.gov/gip/dynamic/hotspots.html

(3)http://www.mauiinformationguide.com/maui-weather-report.php

(4)http://www.accuracyingenesis.com/seamount.html

Intro: Aloha!

Maui!

Hi all! My name is Jordan, I'm a senior in my last semester here at UCD perusing my B.A. in Psychology. I moved to the Colorado foothills about 8 years from Maui, Hawaii. Being born and raised in Maui, I was always surrounded by spectacular scenery and fascinatingly beautiful landscapes which for the most part I took for granted. Rarely, if ever, did I consider my surroundings from a physical geographical standpoint. By taking an in depth look at Maui, I hope to gain a greater understanding of the development of the islands, Particularly the formations of Mt. Haleakala, and be able to appreciate my home from both scientific and aesthetic perspectives.