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If you have been waiting to see some statistics on how our winter of 2011-2012 rated compared to climate history, or if you were hoping for a long range forecast (educated guess) for the summer of 2012, stay tuned, I am working on both. I’ve been preoccupied with getting the 2013 Alaska Weather Calendar printed and out to stores. That rush is easing and I hope to increase the blogging frequency at least to where it was before. If you would like an automatic email when a new article is posted, sign up for that service under “Subscribe to Posts” either on the menu items across the top of the page or on the right hand sidebar items.

Of course, I can’t really do a winter wrap-up or declare a winner in the Iditasnow until winter is a little more over, can I? Look at what has been happening around the state:

In the Arctic, no one expects anything like spring weather for some time to come. In fact, the weather there has been pretty average for this time of year: Temperatures in the 20s F (around -5C) with some wind, a little snow and blowing snow lately. However, just a few days ago it was below zero on the North Slope and Bering Strait area. After a very snowy winter in Kotzebue, the 27 inches (69 cm) of snow on the ground is holding steady with well below freezing temperatures.

The plows are still needed in Shishmaref. Click on the image to see it full size.

On the west coast, Alaska Peninsula and the Aleutian Islands winter is holding on very tightly. After a moderate April in Nome, temperatures are showing little if ay upward trend, running about 10 F degrees (5 C degrees) below average, with new snow over the last couple days. The Pribilof Islands have have also been about 10 degrees below average this month, with snow on 7 of 11 days so far, and 21 inches (53 cm) on the ground. Worse is the sea ice still surrounding them and its negative impact on area fisheries. The ice edge is way farther south than usual and, so far, not showing much inclination to retreat north for the summer. St. Paul has been in the pack ice for the longest period since regular record have been kept. Along the AK Peninsula and Aleutians the mostly north winds have been picking up moisture off the ice-free southern Bering Sea and showering it on the volcanic arc in the form of rain and snow showers. At Cold Bay, snow has fallen every day so far this May, and fell 24 of 30 days in April. They have more than doubled their seasonal average, and have been climbing steadily in the Iditasnow standings.

A couple of maps might shed some light on the situation:

This recent sea surface temperature analysis also shows the ice edge in a general way. Look at the very cold water in the southern Bering and quite cold North Pacific: 5C down to around latitude 45N. This heat sink is not going to go away soon.

The 500 mb maps shows a strong low near the Bering Strait streaming cold air out of the polar regions, over the Aleutians and and around the low into Southeast Alaska. This low is forecast to drop south then east and end up near Yakutat. Some relief from the cold is likely after this low dissipates next week.

The interior usually heats up faster in spring than any part of the state due to its distance from moderating ocean influence. With a couple mountain ranges to block cool, moist marine air, the interior responds mostly to radiational effect, which are steadily going more positive with the lengthening days. The warm up is happening now after lingering winter cold in the first few days of May (down to 13 F (-11 C) at McGrath on the 2nd, and 8 (-13) at Bettles on the 3rd. Temperatures are close to average now, with Eagle’s high of 60 F (16 C) yesterday being the first such temperature for the interior since last summer, as far as I can tell.

Spring is springing slower in Southcentral Alaska as well, but nothing too extreme. However, there is still 16 inches (41 cm) of snow in Valdez after the very heavy snow year for the whole region, especially coastal areas.

Southeast Alaska is usually the warmest part of the state in early spring, until overtaken by the interior, and by mid-May has usually had more than its share of sunny, warmish days. Not this year. It’s been wet, cool and windy almost without exception. High temperatures (a better gauge than average temperatures in this case) have been running 5 to 10 degrees below average and precipitation 2 to 3 times average at most stations. Ketchikan has been soaked with around 11 inches (280 mm) of rain already in May, compared to 8.20 inches (208 mm) for the long term average for the whole month. At Skagway, 30-35 mph (50-55 km/hr) south winds paired with mid-40s (~7 C) temperatures are playing havoc with the early tourism business. A handful of cruise ships having already made it to the top of the Inside Passage, but at least one smaller vessel has altered its schedule to avoid bad days on the Lynn Canal blowhole, where 35 kt (65 km/hr) southerlies have been kicking up 7 foot (2 m) seas over the past 24 hours, and close to that on other days.

The Carnival Spirit docked at Skagway Friday, with little action on the dock. Note the webcam's rain splattered lens. Image used courtesy of White Pass & Yukon Route. Current webcam images here.

About now this question tends to surface: Does the cold spring portend a cold summer? It looks like a significant warming is at hand mid to late in the coming week, but that says little about the rest of the summer, so check back for some info on this soon.

How is spring progressing where you are? That info, or any questions or comments are welcome via the comments link below.

Since the leap day checkpoint report, most towns have slowed their snowfall pace. Haines and Yakutat, however, have been running hard, each having added an impressive 50 inches this first half of March.

The Top Ten as of 15 March

Remember, the standings are based on snowfall this season compared to the station’s average yearly snowfall. (No, I did not come up with this rating scheme to just to put Haines in the lead). Read the rest of this entry »

Today is the start of the world famous Iditarod trail sled dog race (“the last great race”), so I thought maybe I should give an report on another (unofficial) great race: the Alaska snow race. It has been a very snowy winter in many parts of Alaska and there is plenty of talk and a little bragging and comparing between towns, so why not make a little fun of it? In no way am I wanting to make light of the real hardships experienced in places like Cordova and Valdez, where schools were closed for more than an isolated “snow day” due to fears of structural failure of school buildings, among other problems. Believe me, I understand the issue of dealing with tons of snow, since I live in one of the major league snow towns (Haines). What I want to do is compare details of a longer list of places facing heavy snow this winter, and look at why. First the standings, as of the leap day checkpoint: units are inches for snow and feet for elevation.

Read the rest of this entry »

The huge section of heavy old snow pictured below finally slid off the roof of our shed sometime in the middle of the night recently. Luckily, it remained jammed vertically in the snow below and did not fall against the shed. What do think it weighs? Click on the photos for a better look…it’s the same berg from opposite ends.

It would not be hard to estimate the weight of this thing if we knew its density. And you might want to know the density your snow for a variety of reasons. One of the more common reasons is to figure if the weight of the snow might damage something. Check out the scene from our school a couple weeks ago: Read the rest of this entry »

It’s been a cold winter across most of Alaska. It’s not the first and it won’t be the last. During every winter there are relatively colder and warmer periods. This year these cold snaps and warm spells seem to be aligned pretty well to the calendar months: November was cold, December warm, and January…one of the coldest, especially for the rail belt and everywhere west. Check out the write-ups from Weather Service personnel in Anchorage http://pafc.arh.noaa.gov/papers/THE%20COLD%20FACTS.pdf and Fairbanks https://nwschat.weather.gov/p.php?pid=201202012052-PAFG-NOAK49-PNSAFG. February is staring off with a big warm-up, thanks to a strong low barreling into Alaska’s midsection like a gut punch. I’m not making any promise that this trend will hold for February. It does look like a week to 10 days’ break for from the cold, but beyond that, I’d be surprised if we don’t get a fair amount of more cold weather (and snow for the coastal and near coastal areas) before the winter is over. See the Climate Prediction Center for more. For this post, however, I want to zero in on an interesting pattern that seems evident during the worst of the cold snaps. Let’s start with this map, used by permission of the Anchorage Daily News.

The figures show the coldest temperature (degrees F) endured at each city over this past weekend (28-29 Jan). Read the rest of this entry »

Alaska is a big place, and the weather system affecting our state right now is even bigger, but I’m going to show you that is it the small scale that counts when it comes to winds of the south and southeast coasts. As I write this, virtually the whole state is under the influence of the strong pressure gradient between a large, deep low in the Northeast Pacific and strong but gradually weakening high pressure in Siberia and the Alaska interior. (The high was up to a crushing 1060 mb a few days ago, compared to the still hefty 1040 mb on this map) Here is the surface map from 3 pm/00z this afternoon from the GFS model (It’s the 12 hr forecast which is about as good as an analysis):

You probably know that where the isobars are drawn with the closest spacing is where the gradient is the strongest and therefore where the wind is supposed to be the strongest. Read the rest of this entry »

Polar lows are small, somewhat elusive, and usually quite potent…cool stuff for weather watchers. They are small compared to their more common, mid-latitude big brother lows, up to a few hundred miles across, compared to a thousand or more miles across for the later. They are more like the size of hurricanes. For that reason, and because they sometimes look a lot like hurricanes on satellite imagery, and because they do share some structural similarities, they are sometimes called arctic hurricanes. The Bering Sea is a hot spot (sorry for all the puns) for polar lows but certainly not the only area…the North Atlantic is a good place too. A interesting polar low recently tracked across the southern Bering, strongly affecting the Pribilof Islands: St. Paul and St. George, but each of the two in curiously differing ways, as we’ll see. Here’s the Infrared satellite image from 15 UTC  (6 am AST) on Jan 3rd. The polar low was still about 200 miles west of the Pribilofs. With most typical low pressure systems, they’d be in the thick of it, but this average-sized polar lows is not yet affecting their weather:

Polar lows often are most impressive on satellite images (many show a more “closed” look than this one) and less so on surface maps due to their size compared to the scale of the typical maps. Read the rest of this entry »

My tips for witnessing unusual, interesting or simply beautiful weather phenomena have always included spending as much time as possible outdoors and keeping your eyes up, as in looking up at the sky often. A couple days ago I found some unusual weather down at my feet. Snow rollers! My other advice is to always have your camera with you, which I did not, but it was close and I was able to fetch it before the mid afternoon dusk turned to complete darkness. Between the duskiness, the falling snow and the flat light, my photos turned out pretty rough, but by the next morning, after a few hours of rain, the snow rollers were history…you would not have suspected a thing. (Please click on the photos to see larger versions.)

Snow rollers form when the snow possesses a certain layered tackiness that allows the top layer to peel off the underlying layer (or sometimes the ground) and stay together as it gets rolled into a ball or tube. The rolling can be bone by either gravity or the wind. No elves or gremlins are needed. If by gravity, a pretty steep slope is usually needed. If wind, then you can guess that a pretty strong wind is needed. Read the rest of this entry »