Alaska has the Highest, the Coldest, the Wettest?
It's getting ridiculous. Alaska already has the highest mountain in North America, more miles of coastline than all the lower 48, and thousands of glaciers and grizzlies. Now comes the claim that a spot in Alaska is the wettest place on Earth.
First, a nod to the reigning champ (sorry). Mount Waialeale, on the island of Kauai in Hawaii, rises 5,000 feet above the sea. As tropical trade winds heavy with moisture attempt to hurdle the mile-high bump, they leave more than 400 inches of rain each year on the mountain. If you saved all that water in a graduated cylinder, it would rise to 33 feet tall.
That's a lot of rain, but meteorologists have recorded even more impressive downpours. More than 1,000 inches of rain fell in Cherrapunji, India, during the monsoon season from 1860 to 1861. In March, 1952, 72 inches of rain fell in one day at Cilaos, on Reunion Island in the West Indian Ocean. Closer to home, on July 4, 1956, a cloudburst in Unionville, Maryland, flooded the streets with an incredible 1.23 inches of rain in 60 seconds.
Despite these impressive statistics, the wettest spot on Earth may be in the Coast Mountains of southeast Alaska, in the high country about halfway between Juneau and Yakutat, according to Jan Curtis of the Alaska Climate Research Center at the Geophysical Institute. Curtis came to this conclusion after looking at weather model data sent to him by George Taylor, a climatologist at Oregon State University. After studying Taylor's Alaska map, which is color-coded for amount of precipitation, Curtis saw a great black spot in the mountains southeast of Yakutat. The black mark meant that the area should receive more than 450 inches of precipitation (rain and the water from snow if it all was melted) each year. That spot, an area between Glacier Bay and the Pacific Ocean at about 10,000 feet, may be the wettest spot on Earth.
Of course, the usefulness of computer models to describe the real world is always debated, and with good reason. No weather stations exist in the area of the alleged precipitation champion, but Taylor's model does use real data as input, and it's checked against what Alaska's 400 weather stations reveal. The model uses real weather data from 1961 to 1990, and also takes into account how winds run into mountains and hills, causing air to rise and condense. Weather patterns may also help verify Southeast Alaska as the wet winner. The presence of the Aleutian Low and the jet stream over the Gulf of Alaska tend to drive winds perpendicular into Alaska's panhandle, slamming the Coast Mountains with lots of rain and snow.
Alaska's greatest recorded precipitation in one hour and one day were both recorded in Southeast. Annette, a town about as far south in Alaska as you can go, in 1958 received more than an inch of rain in one hour. Angoon, on Admiralty Island south of Juneau, recorded more than 15 inches of rain on an October day in 1982.
Curtis pointed out that the town of Little Port Walter, one of the closest weather stations to the black spot, gets more than 220 inches of precipitation each year. With upslope winds causing air to cool and lose its ability to hold moisture with altitude, the Coast Mountains receive a lot more rain and snow than Little Port Walter, which is about 12 feet above sea level. Curtis thinks it's quite possible the model is correct, and Alaska has the wettest spot on Earth.
A great place needs contrasts. If all of Alaska were as wet as that place west of Glacier Bay, we wouldn't want to live here. We might rather live in a place more like Barrow, one of the driest areas of the state with an average of about six inches of precipitation each year. If you really like dry, you would have loved 1935, when the weather service in Barrow recorded just 1.61 inches of precipitation the whole year.