Is April a dire weather month in Alaska?

I try to keep the number of errors in my Alaska Weather Calendar to a minimum. I have a team of freelance editors and proofreaders to help me, otherwise it would be hopeless. My hat is off to them. Nonetheless, errors slip by, mostly because I introduce them via last minute changes that few if any of my checkers get to to check. Nobody’s perfect, so I don’t fret over the occasional slip-up. In fact, the typo just brought to my attention gave some levity to local author Heather Lende who spotted it and used it in her blog, so I decided to play it a little more here.

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On various calendar date blocks I give a short review of a historical weather event or weather or climate lesson appropriate for the day or season. For April 13th on the current calendar, I wanted to relate that this is the driest time of year for most parts of Alaska. Instead I called it the direst time of the year. Let’s look at both questions.

Dire?

I’d say at this time of year we have a strange interplay between the dire and the hopeful. Dire when there is more sideways snow and you know it will not be the kind you can ski on. Hopeful when the wind dies, the sun comes out and it gets warmer than it has been in many months. Hopeful, too, when the snow melts back day by day, but dire when the melting seems to reveal only mud and things that should have been put away last fall. I think a real biggie is that April starts the teasing season: days are longer, some nice weather comes along, but when it backslides it is still early enough to be real wintery. And remember, “nice” and “wintery” are relative considering the vastly differing  range of weather from Ketchikan to Barrow. But the contrast is still there…maybe more so in May for the Arctic. On a more serious note, many people struggle at this time of year because they have been looking forward to Spring to improve their personal outlook and when it doesn’t, things can look dire.

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Dry?

Easy question here. April is the driest time or about as dry as any time of year for about three quarters of Alaska’s area. The Arctic Coast is very dry from December through May…very little difference, month to  month at Barrow, for one, so “about as dry as” works here. April is more clearly the driest month in the interior and southcentral Alaska. Along the south and southeast coasts and the in the Bering Sea and Aleutians, April is relatively dry, but the months keep getting drier as spring turns to summer and June or July is typically driest in those areas.

The other weather answer: Warming

How about April warming? Here is a table showing how much warming happens at various locations from April 1 to May 1 of an average year. The data is from the daily normals (1981-2010) published by the NCDC. These are smoothed averages from 30 years of data. Both highs and lows are important and it is instructive to see how they differ. You can also see the differences in diurnal range from place to place, though that is what we are after here.

click on small chart for °C

Notice that the places which warm the most in April are the coldest places (they have a lot of catching up to do), then interior stations (the land warms quickly, especially when the snow is gone–the days are very long and the skies fairly clear). After that are the south and southeast coasts (they have much moderating water nearby, but also the continental land mass to aid warming) and the least amount of warming happens in the Bering Sea and Aleutian islands (due to the overpowering influence of the cold, cold ocean surrounding the small land masses). This is one of the reasons Unalaska/Dutch Harbor is featured in the “world’s Worst Weather” special section of my 2015 Alaska Weather Calendar. Only about 4 or 5 degrees F (2-3  C) of warming in the month compared to 20-25 F (11-14  C) in the northern interior!

I’ve included two stations that lie a ways above their towns. The Keystone Ridge station is about 1,150 ft (140m)  higher than the Fairbanks Airport. The high temperature there warms about as much as at the airport during April, staying a little cooler. However the low temperatures are much milder (hard to say warmer) at the start or April, as they are all winter. By May 1 the difference is mostly gone…the large winter inversions that give the higher elevation locations the break from the worst of the cold become weak, shallow or nonexistent in spring through fall. Glen Alps is over 2,000 ft (600 m) above the Anchorage “bowl.” There are plenty of days in mid winter where Glen Alps is getting warm wind off Prince William Sound and the flat parts of Anchorage are stuck in a stagnant cold pool, but by April these situations are fewer and the averages show it: less warming in April and the highs are quite cooler by May 1.

How do you look at April? Dire? Hopeful? A little of each? Let me know your outlook as well as any thoughts, additions, corrections (typos?) questions etc via the comments link below. And hang in there…Spring always comes eventually.

Alaska weather on a roller coaster

Wind-blown dust in Haines and other places.

forecast-map

Red flag wildfire danger for the Mat Valley.

Strong pressure gradient along coast.

Back into the freezer

The strong “January thaw” that pushed well into the interior and tied the all time January record for Alaska is being pushed toward the back of our memories by seasonal and colder weather. Boy, it feels colder after a long warm spell! Wind chills here in northern Southeast Alaska are bouncing down to 5 to 15F below zero (-20C to -26C) at times. The wind tunnel of Lynn Canal has had sustained 50 kts with gusts to 76 (58/88 mph, 26/39 m/s), while Juneau has had moderate Taku winds, which come over the mountains instead of around them, giving them a particular gustyness. Southcentral has been feeling the cool-down and wind for several days. Gap winds funneling  through the mountains on their way to fill ocean low pressure areas hit the usual Palmer, Whittier,  (sustained winds ~35 mph with gusts to ~58 [15G26 m/s ]), and Valdez (30G50 mph [13G23 m/s]).  River flats left bare from the recent thaw provided the light glacial silt so easily picked up by the winds. Both Palmer and Haines reported haze or blowing dust with visibility dropping to 2 miles (3 km) at Haines (the Haines airport is closer to the river than at Palmer.) Meanwhile interior temperatures have fallen 80+ Fahrenheit degrees (50 Celsius degrees) in some places since late January!

Nothing new under the icy moon

The most interesting thing about this weather event, in my opinion, is that it is really nothing out of the ordinary. Many days of every winter are spent tying things down or chasing them down all along the coast. Many worse wind storms have come and gone, even this winter. Take Skagway. The peak wind of 36 kts (41 mph, 18 m/s) yesterday has already been endured there on 36 other days since November 1st of this winter, 11 days with a more respectable 43 kts or 50 mph (26 m/s).  The warm spell in the last half of January was in a different class. Quite a few stations have new records for January, either single warmest day or warmest January average. Many others place it in the top 3 or top 5, etc. But, as warm and record-breaking as it was, there were past times when it was, depending on the individual spot you’re looking at, almost as warm as, as warm as, or even warmer than January 2014. Alaska winter weather has always included wild swings between warm and cold. Looking at averages does not tell the whole picture. Look at this graph of Anchorage temperatures from 1992. Then click on the graph to browse other years at the NWS site. You’ll see a common theme, with many variations: winter temperatures spend about as much time in the extremes as they do in the so called “normal” range. Around March things settle down, and the summer weather sticks much closer to the score. Similar tune for most parts of Alaska.

PAFC 1992 Annual Temps

Yes, there are some stable, in-between weather periods…winter weather nirvana to most of us. Lets hope for some more of those before the winter is over. What are the ups and downs of weather where you are? What is your idea of winter weather nirvana? Please use the comments link for feedback or questions.

Flying through the JAWS of Southeast Alaska Weather

While waiting to board my Alaska Airlines flight from Juneau to Seattle April 9, the all-to-common announcement came over the PA about a likely weather delay. As I happened to have my laptop handy with Internet access available, I quickly checked the Juneau airport weather observations. I did not see any weather issue that would keep the 737 on the ground. The ceiling and visibility were way above minimums. The wind was strong, but pretty well aligned with the runway…not too bad. Here are the observations in METAR format (click here for help in reading them).

PAJN 091353Z 12021G36KT 10SM -RA FEW018 BKN036 OVC050 06/02 A2918 RMK AO2
     PK WND 12036/1349 PRESFR SLP880 P0001 T00560022
PAJN 091453Z 13028G37KT 7SM -RA FEW013 BKN032 OVC045 05/03 A2914 RMK AO2 
     PK WND 13041/1431 SLP867 VIS LWR S-SW P0000 60004 T00500028 58048 

PAJN 091553Z 12022G33KT 3SM -RA FEW013 BKN032 OVC045 05/03 A2912 RMK AO2 
     PK WND 12036/1501 SLP859 P0004 T00500033

What was I missing? Before I could dig deeper, one of the pilots got on the PA and re-educated me, and the whole crowd–mostly seasoned Alaskan flyers with way more weather and aviation savvy than you’d find at a typical airport down south. Read the rest of this entry »

Signs of Spring in Alaska

We’re a few days into Spring, at least according to astronomers. Last Wednesday (3/20) was the Vernal (Spring) equinox–equal night, equal day. While the flowers may be blooming many places in the Lower 48, such traditional signs of spring are a long way off here in the frozen north. But here are a few signs of the season for this equinox time of year in Alaska: Read the rest of this entry »

Two kinds of cold in Alaska

Dry cold, wet cold?   no.

Winter cold and summer cold?  no. Bitterly cold vs extremely cold?  no. Calm vs windy cold? close.

All these would make good blog subjects, but what I’m thinking about today is domestic cold vs imported cold. Seriously.

I have a good recent example. Read the rest of this entry »

The power of the sun

Although the world apparently did not end on Dec 21, 2012 the date triggers strong feelings for most Alaskans every year. Of course it is because it marks the winter solstice…the shortest day of the year…and the promise of longer days ahead. It’s a few weeks past the solstice before most Alaskans notice any change, and even longer for the increasing solar radiation to have any noticeable effect on the weather. So, congratulations, we’re about at that point, and in my psychological bag of tricks for keeping upbeat through the Alaskan winter, it is the point beyond which things have got to just keep getting better. My advice is to get outside as much as possible and ingest some of the increasing daylight. At this point in the cycle (January 12th) here are the daylight stats:

city day length (hr:min) daily change (hr:min)
Barrow 0:00 n/a
Kotzebue 3:45 +0:08
Fairbanks 4:54 +0:06
Nome 5:02 +0:05
Anchorage 6:16 +0:04
Bethel 6:22 +0:04
Juneau 7:00 +0:03
Kodiak 7:08 +0:03
Ketchikan 7:37 +0:03
Adak 8:13 +0:02

Read the rest of this entry »

Why is it so cold in Glennallen?

The question in the title came to me in an email, but for every email I get there are probably hundreds asking the same question in Glennallen. Sure, there are thousands more asking it about where they live, be it Fairbanks or Juneau or Orlando for that matter. But I want to look at what appears to be a unusually cold spot this winter, the capital of the Copper River Valley, population, after throwing in close neighbors Gulkana, Gakona, Copper Center, etc, of a 1,100 or so very tough Alaskans.

Let’s look at the weather depiction map from yesterday Morning, courtesy of the Alaska Aviation Weather Unit. A great example, as Gulkana (that’s where the weather station is located), labeled with its 4 letter code PAGK, was the colder than any station except Northway (PAOR)! It was 40 below (Fahrenheit or Celsius, take your pick), colder than Fairbanks at the time and most of the rest of those off the map to the north. Those around it are way warmer, with only Eureka (PAZK) being in the same ballpark. Talkeetna (PATK) and Anchorage (PANC) are not even below zero! Are not all these places in the Southcentral zone?

Read the rest of this entry »

Termination dust waits for no one

When I moved to Alaska in 1982, I was a real cheechako. I did not even know what termination dust was. The term was never mentioned in meteorology school. It does not appear in the meteorology glossaries of the NWS, American Meteorological Society or the Weather Channel, nor is it in Wikipedia. Back then it was a bit of an initiation for new arrivals to figure out what the others were talking about. Here are a couple recent examples, taken Tuesday evening, August 28th. (I back-dated this post a few days to that date.)

Looking west from the Haines High School track. Read the rest of this entry »