Wonder Lake View

Nice photo of Denali from the near the Wonder Lake rangers station Tuesday morning. Photo courtesy of the National Park Service.

Arctic Sea Ice

Sea ice coverage in the Arctic Basin was pretty close to normal during the spring, but has been decreasing much faster than usual the past several weeks. To the right below is the Alaska-centric view of coverage as of Monday, June 18th. Notice that the Bering Sea is nearly ice free now. On the left is the plot of total areal coverage from the National Snow and Ice Data Center, illustrating the dramatic decrease since the end of May, and is a result of so much of the Arctic sea ice now being first year ice, that is, ice that formed this past winter, which is not very thick and susceptible to summer melt.This is evidently the lowest total sea ice coverage for mid June in the satellite era (1979-present)

Courtesy of the University of Illinois

Courtesy of NSIDC

Nice photo Saturday afternoon from the Ester Dome webcam, looking southeast across town and the Flats, with a flat topped cumulus producing some light rain down toward North Pole. Image courtesy of the FAA.

Fairbanks Temperatures

Here's an update on Fairbanks temperatures, with my preferred standardized anomaly plot. The three to four week cycle that temperature  followed over the winter has, as expected, somewhat broken down. The chart also illustrates that the warm weather earlier this month (mean temperature of 69F on the 8th), was, relative to the typically variability for a given time of year, the farthest above normal for any day this year.

Catching Up

Back in town. Some highlights:

Keystone Ridge had 16 days in May with exactly a trace of precip. Only eight days with measurable precip.

As of Thursday morning, Jun 14, total acreage burned in Alaska so far is just of 33,000 acres.

More to come as I get caught up.

Even Bigger Lightning Day

This has been an active week for thunder, with Monday being the first day of the season with more than 1000 strikes. Tuesday was even more active, with more than 4000 strikes in the Interior, with many fire starts.

Traveling

I'm traveling for a couple weeks so posting will be light o rmaybe none, depending on connectivity issues.

First Big Lightning Day

The thunder season has gotten off to an early, but otherwise slow start. Up until Tuesday, there had not yet been a day with even 100 strikes state-wide. That changed big-time Tuesday as a strong trough aloft touched off more than 700 strikes, most of them in an arc from Old Crow, YT southwest to the Nulato Hills. The trough passed through Fairbanks-land mid-AM, too early to touch off thunder. There were very few early afternoon in the uplands north of the Steese Highway. This is the latest date for the first 100 strike day since 2001.

High Water Follow-up

Here's an update on the high water over the holiday weekend. At the left are Monday morning hydrographs for the upper Chena and lower Salcha Rivers. The peak stage Saturday on the Salcha was the highest stage in four years, and on the Chena the highest since 2003. The Chena at Fairbanks crested Sunday at 6.4 feet, which is notable mostly in that it's a five foot rise since last week.

It's a Soaker

 May only rarely brings soaking stratiform rains that send Interior Rivers out of their banks, but this is one of them. Here is the Saturday morning hydrograph from the Chena River near the Mile 40 Bridge. In addition to much more rain than anticipated, this rain also accelerated high elevation snowmelt. At the Munson Ridge SNOTEL, at 3100' MSL south of Chena Hot Springs, there was still a snow depth of four inches being reported Friday morning, which is now down to one inch, which is at the noise level. Fairbanks Airport set a new precipitation record Friday with 0.52 inches of rain.

Other rain amounts in the area include
Salcha River RAWS: 1.23 inches
Mile 40 Chena Hot Springs Road: 0.99 inches
Birch Lake RWIS: 0.94 inches
Woodsmoke near North Pole: 0.77 inches
Fort Knox Mine: 0.70 inches
Keystone Ridge: 0.68 inches
Aurora: 0.62 inches
Fairbanks Mid-town: 0.59 inches

Summer Rains

It's a sure sign on summer when I start posting hydrographs. Here is the plot of observed and forecast stages on the Salcha River at the Richardson Highway bridge. Water levels have been rising in response to showers the last few days, and will rise more with the steady rains today. Since late Thursday evening, rainfall amounts of a quarter to one inch of rain has been common, with the highest amounts east of Fairbanks and the lowest west of town.

Rain

After two weeks of sprinkles, most parts of Fairbanks-land received measurable rain Wednesday from showers. However, as expected in showery precipitation, amounts were highly variable. Photo from Thursday morning looking south from UAF West Ridge, courtsey of the Alaska Climate Research Center

Rainfall Wednesday included:

Keystone Ridge: 0.28 inches
UAF West Ridge: 0.20 inches
Fort Knox Mine: 0.17 inches
Goldstream Creek: 0.15 inches
Fairbanks Airport: 0.04 inches
East Farmers Loop: 0.02 inches
Aurora: 0.02 inches
Eielson AFB: 0.01 inches
North Pole: Trace

First 70 in Fairbanks

Fairbanks Airport made 70F today for the first time this year. This is exactly the average date (1930-2011) for the first 70º temperature.

Winter Hangs on

Temperatures are warming up across northern Alaska and snow cover is starting to go at low elevations even on the North Slope and Bering and Chukchi Sea coasts. Not so much yet though at higher elevations in of the Brooks Range. The photo at the right taken Sunday morning is from Ivotuk, southwest of Umiat at about 2000 feet elevation.

Warming Up

Temperatures so far this this month have been significantly below normal, as the updated standardized daily temperature anomaly chart at the left shows. Through Wednesday, the high temperature at the Fairbanks Airport for the spring has been 61º on April 16th and again on May 12th. However, that's set to change as the first really warm weather of the season is in the cards, as high pressure aloft builds and has already put an end to the daily convection. Over the past 80 years the mean date for the first 70º temperature in Fairbanks is May 21st, and this year will be very close to that date. 

Cool May Morn

Temperatures fell overnight as skies cleared and the airmass remains on the cool side. Low temperatures Monday morning were near or below freezing in much of Fairbanks-land, including

Updated...
Goldstream Creek: 22F
Eielson AFB: 28F
UAF West Ridge: 28F
Fort Wainwright: 30F
Fairbanks Airport: 30F
Keystone Ridge: 32F
Cleary Summit: 35F
 (Photo Monday morning courtesy of the Alaska Climate Research Center)

The snowpack is getting pretty dirty at Barrow, as this late morning photo  from the UAF Sea Ice groups shows. it's been a cool spring in Barrow, with the temperature the first nine days of May averaging 8 degrees below normal. On the bright side, Barrow had their last sunset of for the summer last night at 12:59am. The next time the sun goes below the horizon at Barrow will be at August first at 220am

Thunder in Fairbanks

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
706 PM AKDT SAT MAY 5 2012
 ...THUNDER AT FAIRBANKS AIRPORT...
...EARLIEST IN 28 YEARS...

A 20 MINUTE THUNDERSTORM AT THE FAIRBANKS AIRPORT EARLY SATURDAY EVENING WAS THE EARLIEST THUNDERSTORM OF THE SEASON SINCE 1984...WHEN THERE WAS A THUNDERSTORM ON MAY 3RD. THUNDER IN THE FIRST HALF OF MAY IS NOT UNCOMMON OVER THE HILLS NORTH AND EAST TOWN...BUT IS QUITE UNUSUAL TO OCCUR SO EARLY IN THE SEASON IN THE FAIRBANKS BOWL. REPORTS OF UP TO ONE TENTH OF AN INCH OF RAIN AND SMALL HAIL HAVE BEEN RECEIVED FROM AREAS ON THE EAST SIDE OF TOWN. $$ RT MAY 2012

(Photo from the FAA's Ester Dome webcam looking southeast at 554pm ADT Saturday)

Chilly on the North Slope...but...

Low temperatures Saturday morning on the North Slope were nearly or a bit below zero, including zero at Barrow, 2 below at Kaktovik and 8 below at Anaktuvuk.

How unusual is this? Not at all. Over the past 50 years, the average date of the last zero temperature in the spring at Barrow is May 3rd.

Webcam photo looking northeast from the Barrow Airport, courtesy of the FAA.

Precip Type in Dry Air

Friday afternoon and evening brought convective showers to Fairbanks-land. However, with a dry and still cool-ish airmass in place, the form of the (light) precipitation that did occur was perhaps not as might be expected. There were a few reports of light rain in the Fairbanks bowl. However, snow was reported near the Chatanika River on the Elliott Highway, below 800 feet elevation. Here on Keystone ridge, it snowed between 330pm and 4pm, with temperatures no lower than 38F. Unsurprisingly, light snow was also reported on Wickersham Dome, elevation 2600 feet.

The graphic shows a plot of the 00Z May 05 Fairbanks upper sounding (heights are in geopotential meters: for practical purposes, just think of the y-axis as in meters). The freezing level was over 3000 feet above the ground. However, the elevation of the "wet-bulb zero" (the elevation that if you saturate the air the temperature would be at freezing) was only 1400 feet above the ground. In at least some of the precipitation shafts, the air was not saturated, allowing snow to fall perhaps as much as 2500 feet below the nominal freezing level.