What no sea ice means

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
240 PM AKDT MON SEP 12 2011

THE TEMPERATURE AT BARROW...THE NORTHERNMOST CITY IN ALASKA...
HAS NOT BEEN BELOW FREEZING...32 DEGREES...SINCE JUNE 29TH. THIS
74 DAY STREAK IS BY FAR THE MOST CONSECUTIVE DAYS THAT BARROW HAS
EVER HAD WITHOUT THE TEMPERATURE DROPPING BELOW FREEZING. THE
PREVIOUS RECORD OF 68 DAYS WAS SET TWO YEARS AGO.

THE TEMPERATURE IS NOT EXPECTED TO GO BELOW FREEZING AT BARROW FOR
AT LEAST A FEW MORE DAYS.

$$
RT SEP 11

This is a direct result of the pack ice being 150 miles north of Barrow and nearshore water temperatures in the 40s.

Autumn

A cloudy Saturday over most of northern Alaska.; polar orbiter image from NWS Alaska Region. Here in Fairbanks-land, rain and temperatures in the 30s and 40s. Snow level is above most of the terrain: at 3pm ADT temperature was 35F at both Munson Ridge (3100' MSL) and Caribou Peak (2500' MSL), 39F here at Keystone Ridge (1600' MSL). Rainfall amounts so far mostly in the tenth to quarter inch range. Combined with the golden foliage, it really seems like autumn, though warmer weather is on tap for early next week.

No urban heat island here

Here is the plot of temperatures for the past year at Eureka, Nunavat, from the Climate Prediction Center. Eureka is on the Fosheim Peninsula, on the north-central side of Ellesmere Island at 80N. Unlike other northern Canadian weather stations in the high Arctic, Eurerka is set back on a deep fjord, so has a less maritime climate that other sites. The middle plot shows the 30-day running mean, which smooths out the day to day variation in "weather", though as the top plot shows, temperatures have been monolithically above normal since early May.

Arctic Sea Ice Seond Lowest of Record

The National Snow and Ice Data Center has released their August analysis of sea ice cover in the Arctic. The mean ice coverage for the month of 5.52 million sq km is the second lowest of the satellite era (since 1979). There is the plot of NSIDC of the August mean coverage: the trend is stunning.



The press release also notes that as of September 5th the coverage had fallen below the minimums measured in both 2008 and last year, guaranteeing that 2011 is at least the second lowest minimum coverage of record. Here is the coverage plot for September 6th from the University of Illinois Polar Research group.



The ice melt season has about two weeks to go, and is certain to be very close to the 2007 record minimum. The implications for Alaska weather and climate are, of course, large. The fact that Barrow has not had a temperature of freezing or below since July 9th is directly attributable to the lack of near shore sea ice and the "warm" waters offshore (as of Seep 6th the NWS Anchorage Marine Ice program had sea surface temperatures of about +6C near Barrow).

Here comes ex-Talas

Here's the surface analysis for 10am ADT Monday from the Ocean Prediction Center. The 956 mb low southeast of Kodiak Island is the remains of tropical storm Talas, and is making for a pretty windy wet day on the Gulf coast. Kodiak has had gusts to around 50 mph and Middleton Island about 65 mph.

Update: As of 5pm ADT, Middleton Island has had winds 63 gusting to 78 mph. The Cape Cleare buoy (46076), a little southwest of Middleton Island has reported similar winds with seas of 26 ft.

Update 2: My old colleague Stu Ostro, who works as a Senior Meteorologist at the Weather Channel, pointed out to me that this storm is not really the remains of Talas, though some of energy may be from Talas. I hang my head. Still though, a deep storm for Labor Day.

Chilly Morning

Autumn is in full swing across Interior Alaska. Here's a photo from Livengood Monday morning (from the FAA) showing the golds of September.

It was completely clear Sunday night/Monday morning, with an aurora through in for good measure. Throw in a seasonable airmass and not much wind, and it's no surprise that Monday was the coolest morning thus far this early autumn, with a fairly widespread frost or freeze in the valley.

Lows reported thus far include:

Goldstream Creek: 25F
Chena Hot Springs: 28F
Woodsmoke PW: 28F
Eielson AFB: 31F
UAF West Ridge: 35F
Fairbanks Airport: 37F
Keystone Ridge: 41F

In the hills this was not the coolest night of the season; here on Keystone Ridge it was the coolest night in almost a month.

Talas Coming to Alaska

Tropical Storm Talas made landfall on southern Japan early Saturday and will move over the Sea of Japan later today. From there the storm will head north and then northeast, and will be a deep storm in the northern Gulf of Alaska by Monday evening. At the right is the 12UTC GFS forecast for 10pm ADT: a 958mb low in the Gulf of Alaska this time of year is quite unusual, but this is a way to do it. The storm will bring plenty of rain and wind to the coast. Here in the Interior, the main impacts will be to produce some wind and keep it reasonably mild. A bigger impact comes with the eventual evolution of the cyclone: ex-tropical systems historically give numerical models fits, especially in the mid range. So will this storm pump-up a ridge over western North America, or spin down in isolation over the Gulf? Time will tell.

Arctic Sea Ice update

Looks like the September 1st total Arctic sea ice coverage is now right at the coverage at this date during the record low 2007 season. Amazingly disturbing but utterly unsurprising. Image from the National Snow and Ice Data Center.

End of Summer

With the foliage now rapidly turning to autumnal reds and yellows, thoughts turn to the end of summer in Interior Alaska, and the question arises, are summers ending later than in years gone by? Of course, I have a chart for this question.

Since a couple of cool days does not autumn make, I've defined the end of summer as the last day in the season when the 7-day centered running mean is 55F or higher. From the plot at the left, it is clear that at least until very recently, there was no trend at all. However, the gray line is the 4 year running mean, and it has, just in the past few years, popped up to the highest value in the century of instrumental records. Through September 1, this summer is already beyond the mean date for the past 40 years, and if the forecast for the next few days works out, this will push this year's "end of summer" later still.

It is very tempting to pin this recent and dramatic change on the loss of sea ice near Alaska, though we need some modeling of this idea.

August Weather Summary

What I did on my vacation…

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1216 PM AKDT THU SEP 1 2011

...MONTHLY WEATHER SUMMARY FOR FAIRBANKS ALASKA...

...FAIRBANKS WEATHER SUMMARY FOR AUGUST AND A REVIEW OF THE SUMMER...

AUGUST WAS A FAIRLY CLOUDY MONTH WITH FREQUENT BUT MOSTLY LIGHT
RAINFALL. THE MONTH ENDED ON A DRIER NOTE THROUGH...WITH A STRING OF
RATHER SUNNY DAYS HIGHLIGHTING THE BEGINNINGS OF THE AUTUMN
COLORS AND A COUPLE OF LATE NIGHT AURORA DISPLAYS.

AT THE FAIRBANKS INTERNATIONAL AIRPORT...THE AVERAGE HIGH
TEMPERATURE IN AUGUST WAS 67 DEGREES AND THE AVERAGE LOW WAS 48
DEGREES. THE MEAN TEMPERATURE OF 57.2 DEGREES WAS 1.1 DEGREES
ABOVE NORMAL. THE HIGH FOR THE MONTH WAS 76 DEGREES ON THE 4TH AND
THE LOW WAS 40 DEGREES ON THE 8TH. THE COOLEST OF THE NORMALLY
COOLER OUTLYING AREA DID HAVE ONE OR MORE MORNINGS WITH FREEZING
TEMPERATURES...INCLUDING 27 DEGREES AT GOLDSTREAM VALLEY BOTTOM ON
THE 30TH AND 31 DEGREES AT WOODSMOKE...NEAR NORTH POLE ON THE
29TH.

TOTAL RAINFALL IN AUGUST AT THE AIRPORT WAS 1.60 INCHES...WHICH
WAS 0.28 INCHES BELOW NORMAL. SOME RAIN FELL ON 22 DAYS AT THE
AIRPORT...FOUR MORE THAN AVERAGE...BUT ON ALMOST HALF OF THOSE
DAYS THERE WAS JUST A TRACE OF RAIN. THE 12 DAYS WITH MEASURABLE
RAIN IS ONE DAY LESS THAN AVERAGE. THERE WERE THUNDERSTORMS IN THE
AREA ON SEVERAL DAYS DURING THE MONTH...THOUGH NONE WAS HEARD AT
THE AIRPORT. AS IS OFTEN THE CASE...RAINFALL WAS SIGNIFICANTLY
HIGHER AT NEARLY ALL OTHER WEATHER OBSERVING LOCATIONS IN THE
GREATER FAIRBANKS AREA. THESE INCLUDE...

AURORA.................1.96 INCHES...0.17 INCHES BELOW NORMAL
EIELSON AFB............2.04 INCHES...0.31 INCHES BELOW NORMAL
UAF WEST RIDGE.........2.18 INCHES...0.10 INCHES ABOVE NORMAL
NORTH POLE.............2.19 INCHES...0.17 INCHES ABOVE NORMAL
FORT WAINWRIGHT........2.35 INCHES
EAST FARMERS LOOP......2.43 INCHES
FAIRBANKS MIDTOWN......2.74 INCHES...0.62 INCHES ABOVE NORMAL
KEYSTONE RIDGE.........2.76 INCHES...0.36 INCHES ABOVE NORMAL

SMOKE FROM THE BONNIFIELD FIRE ON THE FLATS SOUTH OF FAIRBANKS WAS
EVIDENT ON SEVERAL DAYS EARLY IN THE MONTH.

FOR THE SUMMER AS A WHOLE...THE AVERAGE TEMPERATURE OF 59.8 DEGREES
AND TOTAL RAINFALL OF 5.07 INCHES ARE BOTH CLOSE TO NORMAL.
HOWEVER...EXCEPT FOR THE LAST WEEK OF MAY...THERE WAS A DISTINCT
LACK OF HOT WEATHER. THE TEMPERATURE REACHED 80 DEGREES OR HIGHER
NINE DAYS...BUT FIVE OF THOSE DAYS WERE IN MAY. THE HIGHEST
TEMPERATURE THIS SUMMER AT THE AIRPORT WAS 88 DEGREES ON JUNE
25TH. ACCORDING TO THE ALASKA FIRE SERVICE...JUST OVER 292
THOUSAND ACRES BURNED IN THE STATE THROUGH THE END OF
AUGUST...WELL BELOW THE AVERAGE OF RECENT DECADES. TWO FIRES
THOUGH THAT STARTED DURING THE WARM WEATHER OF MAY WERE OF MAJOR
CONCERN TO THE FAIRBANKS AREA....THE MOOSE MOUNTAIN FIRE ABOVE
GOLDSTREAM VALLEY AND THE HASTINGS FIRE NORTHEAST OF MURPHY DOME.

LOOKING AHEAD TO SEPTEMBER...THIS MONTH TYPICALLY FEATURES MILD
TEMPERATURES AND BRIGHT AUTUMN COLORS EARLY ON FOLLOWED BY A TASTE
OF THE WINTER TO COME BY THE LAST DAYS OF THE MONTH. THE AVERAGE
HIGH TEMPERATURE DROPS FROM 62 DEGREES ON THE FIRST TO 46 DEGREES
ON THE 30TH. THE AVERAGE LOW TEMPERATURE DROPS BELOW FREEZING ON
THE 25TH. IN THE LAST 106 YEARS...TEMPERATURES IN FAIRBANKS HAVE
RANGED FROM A HIGH OF 84 DEGREES IN 1957 TO A LOW OF 3 ABOVE IN
1992. PRECIPITATION AVERAGES 1.10 INCHES. MOST...BUT NOT
ALL...SEPTEMBERS SEE THE FIRST SNOW OF THE UPCOMING WINTER...AND A
SMALL ACCUMULATION IS NOT UNUSUAL DURING THE LAST WEEK OF THE
MONTH. TOTAL SEPTEMBER SNOWFALL HAS EXCEEDED SIX INCHES JUST FOUR
TIMES IN THE PAST CENTURY...BUT THREE OF THOSE YEARS WERE IN THE
1990S.

$$
RT SEP 11

Late summer sunshine

A lovely last day of August at Arctic Village, from the FAA webcam

Return of the Inversion

I was outside at 1230am Sunday and the sky was filled with stars; just a band band of light on the northern horizon (one of the many benefits of outdoor plumbing). Weather-wise, this can only mean one thing: the return of the inversion.
On the left is the temperature plot from the 3AM upper air sounding from Fairbanks, showing a 6.4ºC temperature increase in the lowest 300 meters. The spread in morning low temperatures is of course wider. Lows include: 26ºF at the Salcha River RAWS, 29ºF at the Angel Creek RAWS. 30ºF at Goldstream Creek Co-op, 32F at the Woodsmoke (near North Pole) PWS, up to lows of 50ºF at Clearly Summit and the Nenana Hills RWISs and 48ºF here on Keystone Ridge, making it one of the mildest overnight lows of the month.

Sea Ice Updated

All eyes are on Hurricane Irene now, but here's a quick update on Arctic sea ice coverage, from the folks at the National Snow and Ice Data Center, and as usual, the news isn't good. As of August 25th, total sea ice coverage is just barely above the record low year of 2007. What's interesting about this is that the atmospheric conditions this summer have not been a repeat of 2007. There have been times that it has been similar, but others when it has not been. This shows the impact of the now much thinner ice than was in place in 2007.

Late Season Thunder

There were about 170 lightning strikes in Interior Alaska on Monday, which is a lot for this late in the season. In fact, some of the cells were producing lightning til well after midnight. Here's the view from west ridge of UAF looking southeast about 910pm Monday.

Pot of Gold Found

A 9pm ADT Monday from the FAA webcam at the Ruby airport. Ruby is along the Yukon River about 25 miles upriver from Galena.

It's a Soaker

Fairbanks-land enjoyed a classic August weekend, with something like 3/4 of an inch of rain spread over Saturday and Sunday. The rain was over a long enough duration that it will not impact rivers much. Here's the hydrograph for the upper Chena River (near Mile 40 Chena Hor Springs Road) from the Alaska-Pacific RFC.

There was enough rain to bring monthly totals up to about normal. However, the number of days with rain since late July is above normal, hence the widespread perception that it has been unusually wet.

Close but no Cigar

The mean Sea Level Pressure at Fairbanks bottomed out at 982.1mb at noon ADT Saturday, 1.2mb above the record low pressure for August.

Deep Storm in the Gulf of Alaska

A fairly deep storm for August is churning through the northern Gulf of Alaska. The 330pm ADT GOES infrared image shows a classic cloud structure to the system, with well defined warm, cold and occluded fronts. Unlike most Gulf storms, this one is forecast by all the numerical models to maintain fairly deep pressures as it crosses the Alaska Range on Saturday. In fact, Fairbanks will approach its lowest August sea-level pressure of record on Saturday of 980.9 mb (28.97 inches) set August 5, 1984.

Fire Weather Season About Over

Damp, if not soaking weather persists over most of Alaska, and more than 200 lightning strikes Wednesday not withstanding, the fire season is about over.

According to the Alaska Fire Service, thus far a total of 292,440 acres has burned in Alaska this summer. This number has not changed (or at least been updated by AFS) for more than a week. This is about 27% of the acreage burned last summer. While not the lowest in recent years, it is well below the 20 year median of 681,000 acres.

Like last year, this year was a classic example of how the fire season in Alaska is so completely dependent on warm AND dry weather. Much of Interior Alaska was not especially wet this summer, but after mid-June there was no period of more than a couple days of dry AND warm weather. Here is a plot of the mean July 500 mb height anomalies:



Over land, lower 500mb heights in the summer correspond pretty well with cooler than normal temperatures. This is just what we see over Alaska. A big negative anomaly near the Bering Strait, but with below normal heights extending eastward.

Now here's the same plot for July 2009, which was one of the warmest and driest Julys of record over Interior Alaska, and a big fire year:



A much different picture over Alaska.

Signs of Autumn

Signs of autumn are starting to show in the vegetation. Here's a photo of the front yard Tuesday afternoon. The dogwood has gone purple and the Spiraea is turning yellow and red. Not much color in the birch and aspen yet but it will not be long.

Oh yeah, yesterday was the first day since July 23rd with zero precipitation here at Keystone Ridge. The 23 days is the longest streak of consecutive days with some precipitation in 15+ years of record here. However, total rainfall during this time was only slightly above normal. A lot of days with trace, 0.01 or 0.02 inches of rain. Output from the solar panels though is way down from the past few years.

Arctic Ice Update

Here's the Alaska-centric view of sea ice coverage in the Arctic as of August 15th. As as been the case for a couple weeks, this summer's coverage is just above the record low year of 2007. There is about another month of retreat left; it looks certain that this year will have either the lowest or second lowest summer ice minimum coverage in the satellite era (since 1979).

Soaker in Denali

The western half of Denali National Park has received a lot of rain in the past couple days. Eielson Visitors Center as received 2.53 inches of rain since late Friday night.
Other amounts include:
Kantishna: 1.60 inches
Toklat: 1.40 inches
Wonder Lake: 1.17 inches

Even this much rain does not normally produce flooding problems in the Park. Freezing levels are lowering and as of Sunday morning are down to about 4500' MSL.

Update: steady rain has ended, as this photo from the NPS at Wonder Lake shows

Snow on the Mountains

I was in Tok Wednesday and Thursday: grey and rainy. Snow level about 5000' MSL Wednesday, and a bit lower Thursday. This photo is of the Sheep Mountains from just east of the Robertson River rest stop on Wednesday.

Warm Weather Frequency

With the Tanana Valley Fair in full swing and a bout of cooler weather the last few days, it reminds me of how quickly temperatures drop off in Interior Alaska, climatologically speaking.

Here is a plot of the frequnecy, by week, of daily high temperatures of 75F or warmer (Data 1905-2010). There are a couple of interesting things here. First, from late May to late June there is a basically linear increase in the frequency, then a plateau the first half of July. The decline is not quite so linear from mid July to early August, but close. Thereafter days with high temperatures 75º or warmer become increasingly unusual. The latest date with a temperature so warm is Sept 21, 1995 during a spectacular chinook.

Fresh Snow in the Brooks Range

FAA webcam photo from Chandalar DOT camp on the Dalton Highway at 1220pm Saturday. Looks the fresh snow level is at about 4500' MSL.

It was NOT 97 degrees at Northway in July

Okay, I guess have have to say this: It was NOT 97 degrees at Northway in July.

There is a news story going around about record highs in all 50 states in July, including 97F at Northway on July 11th. 97F would be an all-time record high for Northway.

Except that the high temperature on July 11th at Northway was 77F.

The 97F high temperature was encoded in an observation, but the temperature sensor was bused (probably the aspirator fan failed). The FAA observers did correct the daily max temp after the original observation went out to the world.

Other high temps that day were in the upper Tanana Valley region were in the upper 70s and lower 80s.

Moral of the story is the same as always: constant vigilance.

Not Much Frost

Skies were never able to clear overnight so there was not much in the way of freezing temperatures in the Fairbanks area. The low at the airport was 44F, but even Goldstream Creek only got to 36F, which is nothing for there (they had 4 days in July with a min temp of 32F or less). Eielson AFB also got to 36F. The coop site at Mile 42 Steese Highway did report a low of 30F. To the north of Fairbanks there were less clouds, and Livengood RAWS reported a low of 28F, and 31F at Seven Mile, just north of the Yukon River on the Dalton Highway.

Now That's a Front

You say it must be getting on towards autumn when Rick starts putting up upper air plots? Well…

A well marked but essentially dry cold front moved through the Fairbanks area Friday mid-morning. We don't often see temperatures this time of year cooler at the surface at 3pm than at 3am in the absence of rain. The 850mb temperature was right at freezing at 3pm, not quite a record but still impressively cool for the first week of August.

Early August Sea Ice

According to the analysis of Arctic Sea Ice coverage by the National Snow and Ice Data Center, ice coverage for July was the lowest of record, even lower than 2007. However, during the last couple weeks of July the rate of ice loss decreased, and as of August 3rd the total coverage is no longer lower than the same date in 2007.



This is potentially good news, but the slower loss may not last. Figure 4 of the analysis, below, shows that there is a lot of first year ice that is still vulnerable to loss in the six or seven weeks that remain of the ice loss season.

Darkness

2am Thursday in Fairbanks: darkness at night, a novel idea.

Wind Clouds

Pretty view of lenticular clouds from Delta Junction Wednesday evening. Surface winds gusted to nearly 50 mph at Fort Greely on Wednesday, which is pretty unusual for this time of year even in Delta.

July Narrative Summary

Public Information Statement
National Weather Service Fairbanks Ak
1211 Pm AKDT Mon Aug 1 2011

...Fairbanks Weather Summary For July...

Weather in July was fairly typical for an Interior Alaska mid-summer...with no extremes of temperatures. Rainfall…as is often the case this time of year...was highly variable.

At the Fairbanks Airport...the average high temperature was 71 degrees and the average low was 52 degrees. The average temperature of 61.8 degrees was 0.7 degrees below normal. The highest temperature for the month was 81 degrees on the 22nd. the low for the month was 45 degrees on the 17th and 20th.

Rainfall was highly variable in the area. At the Fairbanks Airport...the total July rainfall was 1.70 inches...almost exactly the normal of 1.73 inches. Measurable rain fell on 16 days during the month...three days more than normal. Thunder was hear at the airport on three days in july...which is also about normal. However...Eielson AFB measured monthly rainfall of 1.39 inches...just barely half of normal. In contrast…the College Observatory cooperative station on UAF West Ridge recorded 2.18 inches of rain in July…which is a tenth of an inch above normal.

Other July rainfall totals include...

University West..........2.84 Inches
Aurora.........................2.68 Inches
Goldstream Creek.......2.63 Inches
Gilmore Creek............2.12 Inches
East Farmers Loop.....2.01 Inches
Keystone Ridge...........1.90 Inches
Fort Wainwright..........1.33 Inches
North Pole..................1.31 Inches
Salcha River At Bridge...0.95 Inches

Much more rain fell in the uplands well east of town...which caused the Chena and Salcha rivers to rise to near flood stage on July 6th. The cooperative weather station at 43 mile Steese Highway recorded 5.53 inches of rain for July...while the automated station near Angel Creek in the upper Chena basin recorded 4.83 inches. Along the Salcha River...an automated gauge about 20 miles above the bridge recorded 4.54 inches of rain.

A couple of wildfires started mid-month on the flats south of Fairbanks...and the Bonnifield #1 fire grew to over 6000 acres by months end. This fire brought smoke at times to the area...which
on a couple of days was thick around North Pole and Eielson AFB.

Looking ahead to august...normal temperatures start to decline noticeably. The normal high temperature falls from 70 degrees on the first to 62 by the end of the month. Normal low temperatures fall from 51 degrees on the first to 43 on the 31st. In the past 106 years...august temperatures in Fairbanks have ranged from a high of 93 degrees in 1994 to a low of 21 degrees in 1922. Low lying areas usually have the first frost of the season in August.

Normal rainfall is 1.88 inches. Snow is very rare at valley level in August...though it has occurred a few times. Accumulating snow has occurred in town just once in August. On August 29th
1922...three inches of snow accumulated in Fairbanks.

Possible sunshine declines by more than three hours...from over 18 hours on the first to less than 15 hours on the 31st. Darkness returns to Fairbanks skies for the first time since late
April...and the first northern lights of the season at often spotted during the last ten days of the month.

$$

RT Aug 11

Fire Season Winding down

This morning's Alaska Fire Service situation report has zero staffed fires in the state, with seasonal acreage burned at 290,600 acres. This is an increase of 28,000 acres since the end of June. There are still a few active fires in the state, including the Chitsia Mountain fire in the northwest part of Denali National Park and the Bonnifield #1 fire on the flats south of Fairbanks. However, with August knocking, 2011 is clearly not going to be a big fire year. It is likely that there will be some more burning, and the total acreage may well reach 300,000 acres by the end of the season. Indeed, numerical models are forecasting a moderate chinook wind event for Monday and Tuesday. Near the Alaska Range there has not been very much rain the past few days, so I expect both the above mentioned fires to grow.

More on Climate Normals

Here's a plot by Blake Moore of the Alaska Climate Research Center showing the location of all sites in Alaska with 1981-2010 normals. There are 203 stations here, a whopping 60% increase in the net number of stations that had normals for the 1971-2000 period. Note though the large areas with almost no stations, including the comparatively heavily populated Yukon-Kuskokwim delta.

Sweet Rain

All of Fairbanks-land has received some rain the past day or so, though amounts vary greatly. Tuesday morning a solid area of rain made it into the eastern portions of the area. In the afternoon thunderstorms developed along the eastern edge of the rain shield. Overnight, another area of steadier rain developed mostly north and west of town. The result of these features is a hodge-podge of rainfall amounts.

At the upper end is the coop observation from Steese Highway Mile 42, with a whopping 2.10 inches. Angel Creek RAWS recorded 1.03 inches, and the CWOP site near Weller School, 1 Mile Chena Hot Springs Road, reported 0.95 inches. The Munson Ridge SNOTEL in the upper Chena Basin received over an inch of rain, though much of the that came late Monday night and Tuesday morning.

The hydrograph (from Alaska-PacificRFC) for the Chena River at the Wendell Street Bridge shows no rise yet (as expected) and only a moderate rise over the next few days as water from the upper Chena basin works downriver.



At the lower end, where we would have like to see a soaking rain, on the Tanana Flats to help squash the Bonnifield #1 fire, there was not much. The Blair Lakes RAWS reported 0.15 inches of rain and the Gold King RAWS, southwest of the fire, reported 0.13 inches. Better than none, but a lot more is needed. The Bonnifield #1 fire is now up to 6449 acres and will likely to continued to smoulder until the snow comes.

More Siberian Heat

Not timely, but just to make sure I note it:

Last Monday, July 18th, Yakutsk had a max temp of 38.4C, 101F. Low was 18.9C, 66F
Amga the same day had a high of 37.9C, 100F.

Also on the 18th, Verkhoyansk, on the Yana River and one of the super cold places in winter, had 34.1C, 94F.

Clear Creek Fire

A couple of fires on the Tanana Flats flared to life this week, and really took off today with low RHs and gusty southwest winds. The plume has been evident on the Pedro Dome radar all day. Here's a photo from about 745pm ADT Saturday from the Alaska Climate Research Center webcam. This produced a dramatic plume from town and, in some places ashfall too. In a much too common story, the models are backing off from any significant rainfall anytime soon.

Update: According to AFS Sunday morning, this is the Bonnifield #1 fire, which grew to over 2000 acres on Saturday. The Clear Creek Fire is onyl a few miles away from Bonnifield #1, and it grew by a couple hundred acres.

Comparing Normals

One of the highlights of the new 1981-2010 normals is that NCDC has employed some fairly standard statistical techniques to develop normals for stations with much less than the full (or nearly full) 30 year period. In part this has become practical with the great increase in computing power over the past 20 years rather than any magical breakthrough in statistical or climatic understanding. That said, here are plots of the 1981-2010 daily normal max and min temperatures for Keystone Ridge (1600' MSL) and Goldstream Valley Bottom (500' MSL, known to NCDC as Ester 5NE). There stations are about nine miles apart in the same drainage, so this is about as close to an apples to apples comparison as there is.

For normal highs, temperatures, Goldstream Valley Bottom runs colder than the ridge from late October until late February.



For normal min temperatures, the valley is always cooler than the ridge, though of course the differences are much larger during the snow cover season.



The other feature of both plots is that for the first time, NCDC has utilized the actual daily values in computing the daily normals. Duh, you say? In the past, NCDC has used a simple spline function that basically mapped a smooth curve of the monthly means to the daily values. As a result, daily normals were simple sine curves that mostly varied in how sharp the extremes were. With these new normals, much more structure in the daily normals. Notice the flat stretch in normal max temperatures during late November and early December at Keystone Ridge.

Arctic Sea Ice at

Gee, what a surprise. As of this week, Arctic sea ice is at a record low minimum for the satellite era (since 1979), running just below 2007. Here is the Alaska-centric view from the University of Illinois. There is about 7 to 9 weeks left of the ice melting season, and 2011 will almost certainly either wind up with lowest or second lowest (behind 2007) minimum coverage.

Snow in Denali Park

Snow fell Monday in parts of Denali Park. Snow at Eielson Visitor Center (3600' MSL) in July is not unusual, perhaps an every other year event on average. Enough snow to close the road in July much less common. Snow at Headquarters, at 2000' MSL, has only occurred once since observations started 90+ years ago. That was in 2003, when there was an inch of snow at HQ.

No big surprise: 850 mb temperatures at Fairbanks were +2.2C 3pm Monday and +1.4C 3am Tuesday. These are low but not excessively so for mid-July. And warmer weather is on the way.

The New Normals are Here

Eagerly awaited by climate fans everywhere, the 1981-2010 normals were released by the National Climatic Data Center earlier this month. Starting August 1, these will replace the 1971-2000 normals in the United States. Here is a quick look at the new normals for Fairbanks and how they have changed from the 1971-2000 set.

The warming in winter continues as the cold winters of the early and mid 1970s have dropped off, and this set comprises almost entirely the warm phase of the PDO. The other big temperature change is in June. Although not large in absolute terms, it is the largest standardized change of any month. This reflects the fact that temperatures don't vary nearly as much in summer as in winter. This early summer warming directly ties in with increased fire seasons.

For precipitation, the only really dramatic change is in July, with a big bump up, enough to make July solidly the wettest month of the year. Traditionally, August in Fairbanks has been the wettest month of the year, but in fact Fairbanks has been near the eastern edge of the area in which August is the wettest month of the year, and that line has clearly shifted westward.

Siberian Heatwave

No, this is not a repeat of a post from last summer. Major heatwave building in central Siberia.

Yakutsk reported max temperature of 95F on Tuesday and 96F Wednesday (Alaska Time). Amga, southeast of Yakutsk had a high of 97F Wednesday.

The numerical models keep this going several more days at least.

Nice Evening in Fairbanks

A delightful Wednesday evening in Fairbanks. Sunny, 68F and pleasant breeze. Love it :)

Fire Creep

Tuesday morning's (July 12) situation report from the Alaska Fire Service states that acres burned this season in Alaska is now up to about 272,000 acres This is an increase of about 10,000 acres since the first of the month. No surprise, with more than 13,000 lightening strikes and several dozen new fires in the past two weeks. However, the pattern has changed and looks locked into a somewhat cooler and damper, but most definitely not thundery pattern for the next week. There were no lightening strikes at all in the state on Monday. Given this forecast, time is running out this to be a major (million+ acre) fire season in Alaska. Once it starts to get dark at night and relative humidities recover, it becomes much harder for fires to dramatically grow. Not impossible, as 2004 and 2005 showed, but those were record dry Augusts with big fires already burning, whereas today the biggest fire that is actively burning is the 3800 acre Lloyd fire, southwest of Tanana. Only two other fires over 1000 acres are actively burning in the state.

I sure hope I don't jinx it by saying this, but it's looking hopeful :)

Convective Rainfall

Slow moving thundershowers brought good downpours to parts of the Fairbanks area on Friday. As often happens with convective showers, amounts varied greatly over short distances. Some totals include:

Around town:
Fairbanks Airport #2: 0.86 inches (near the Airport Post Office)
Fairbanks ASOS: 0.52 inches
Aurora Coop: 0.28 inches (near Lemeta)
Fairbanks Midtown: 0.15 inches
UAF West Ridge: 0.10 inches
East Farms Loop: 0.08 inches
Fort Wainwright RAWS: 0.03 inches

North Pole area:
North Pole-KJNP: 0.13 inches
Woodsmoke: 0.08 inches
Eielson: 0.01 inches

North of town:
Goldstream Valley Bottom: 0.56 inches
Goldstream Creek: 0.30 inches
42 Mile Steese Hwy: 0.26 inches
Fort Knox Mine: 0.19 inches
Chena Hot Springs: 0.05 inches
Keystone Ridge: 0.04 inches

Big High Aloft: the North Pole Edition

Here is the 4am ADT Friday 500 mb analysis by Environment Canada. See that huge 585 dm high near 85N/170W? My friend and former colleague Stu Ostro has done some work with the NCEP reanalysis data (1948-2011), and finds that this is close to the highest 500 mb height of record in the 85-90N belt (exactly where it ranks will depend on how the numbers shake out in the reanalysis). What this translate to is that, as a first approximation, underneath the high, the average temperature in the airmass between the surface and 500 mb (about 18000 feet) is about as warm as it has been anytime in the past 63 years.

Update: according to the NCEP reanalysis, on Thursday Jul 07 the mean 500 mb height 85-90N was 5877 gpm. This breaks the previous record daily average of 5848 gpm set in July 1966

Arctic Sea Ice

The monthly National Snow and Ice Data Center analysis of Arctic sea ice coverage is out for June, and shows that the ice extent at the end of June is the second lowest of the satellite era record, just behind—last year. This morning's webcam shot from Barrow shows all the shorefast ice is gone.

It is a near certainty this year will be among the few lowest sea ice minimums of record, and certainly could exceed 2007.

Seward Peninsula Storm

Here's a statement Tuesday evening from my colleague Wes in Nome about the less than delightful weather for the 4th in my old hometown. This was the front end of Bering Sea storm that brought 40+ mph winds and soaking rains to Nome-land on Tuesday (4pm ADT Tuesday analysis from Environment Canada)

...FOURTH OF JULY 2011 IN NOME ONE OF COLDEST ON RECORD...

THE INDEPENDENCE DAY JUST CELEBRATED IN NOME, ALASKA WENT DOWN IN THE
RECORD BOOKS AS ONE OF THE COLDEST ON RECORD. THE TEMPERATURE
PLUMMETED TO JUST BELOW FREEZING AT 31 DEGREES JUST AFTER 6 AM MONDAY
MORNING...JUST ONE DEGREE SHY OF THE ALL-TIME RECORD FOR THE FOURTH
OF JULY OF 30 REACHED IN 1924. THIS MADE IT THE SECOND COLDEST
TEMPERATURE EVER IN NOME ON INDEPENDENCE DAY.

WHILE THE DAY BEGAN WITH A COLD SUN AFTER SUNRISE, CLOUDS MOVED IN
FROM THE SOUTH BY LATE MORNING AND THICKENED THROUGH THE AFTERNOON
BEFORE RAIN SET IN BY MID-AFTERNOON. THE RAIN MEASURED OVER A
QUARTER OF AN INCH (0.27 INCHES), MAKING IT THE ELEVENTH WETTEST
INDEPENDENCE DAY IN NOME IN OVER 100 YEARS OF RECORDS AND THE WETTEST
IN NOME SINCE 2003.

BY MIDNIGHT THE TEMPERATURE HAD MANAGED TO RISE TO 45 DEGREES,
ENSURING AN AVERAGE TEMPERATURE OF 38 DEGREES FOR THE DATE. WHILE
NOME HAD REGISTERED A COLDER TEMPERATURE ON THE FOURTH IN 1924, THE
INDEPENDENCE DAY 2011 EDITION IN NOME TIED FOR THE COLDEST AVERAGE
TEMPERATURE EVER...WITH THAT OF 1985.

DESPITE WHAT MANY MAY HAVE DESCRIBED AS A MISERABLE, VERY UNSUMMER-
LIKE WEATHER DAY ACROSS THE SOUTHERN SEWARD PENINSULA WITH EVEN A
COATING OF SNOW REPORTED SNEAKING DOWN TO MIDDLE ELEVATIONS OF THE
INTERIOR HILLS...NOMITES CELEBRATED IN TRADITIONAL FASHION ENJOYING
PARADES, FLAG-WAVING, GAMES, RACES, REINDEER DOGS, AND ICE CREAM.
HOWEVER, MANY DID SO THIS YEAR WEARING COATS, GLOVES, AND HATS.

The Longer View

Here's a plot from the Climate Prediction Center of temperatures and departures from normal for the past year at Fairbanks. The middle plot shows the 31 day mean departure. This smooths out the short-term "weather" variations and bring out seasonal length patterns: warm late last summer and autumn, then mostly cooler than normal winter and spring, and now near to a bit above normal.

Fairbanks June Wx Summary

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE FAIRBANKS AK
1245 PM AKDT FRI JUL 1 2011

...JUNE WEATHER SUMMARY FOR FAIRBANKS...
...MILD AND WET...

JUNE STARTED OFF WARM AND DRY...CONTINUING THE TREND FROM LATE MAY. THIS ALLOWED FOR SMOKE FROM INTERIOR WILDFIRES ON A FEW DAYS...BUT IN TOWN THE SMOKE WAS NOTICEABLY DENSE ON JUST ONE DAY. STARTING ON JUNE 9TH...SHOWERS AND THUNDERSTORMS BECAME MORE FREQUENT. THUNDER WAS HEARD AT THE AIRPORT ON FOUR DAYS IN JUNE...COMPARED TO AN AVERAGE OF THREE. THE LAST THREE DAYS OF THE MONTH SEEMED MORE TYPICAL OF AUGUST WEATHER IN INTERIOR ALASKA...WITH THICK CLOUD COVER AND PERIODS OF STEADY RAIN.

AT THE FAIRBANKS AIRPORT...THE AVERAGE HIGH TEMPERATURE WAS 70 DEGREES AND THE AVERAGE LOW 51 DEGREES. OVERALL...THE AVERAGE TEMPERATURE FOR JUNE OF 60.4 DEGREES WAS 0.7 DEGREES ABOVE NORMAL. THIS TEMPERATURE EXCESS WAS DUE TO WARMER THAN NORMAL OVERNIGHT LOW TEMPERATURES...WHICH WERE BOOSTED BY FREQUENT NIGHTTIME CLOUD COVER. ONLY ONE DAY HAD A TEMPERATURE ABOVE 80...BUT THE HIGH TEMPERATURE OF 88 DEGREES ON JUNE 25TH WAS THE HIGHEST JUNE READING SINCE 2004. THE LOWEST TEMPERATURE DURING JUNE AT THE AIRPORT WAS 43 DEGREES ON THE 5TH AND 10TH. SOME OF THE NORMALLY COOLER LOW LYING AREAS RECORDED LOW TEMPERATURES NEAR OR JUST BELOW FREEZING EARLY IN THE MONTH...INCLUDING 30 DEGREES AT GOLDSTREAM VALLEY BOTTOM AND 33 DEGREES AT WOODSMOKE NEAR NORTH POLE...BOTH ON JUNE 5TH.

THE MONTH STARTED OFF CONTINUING THE DRY WEATHER OF SPRING...BUT SHOWERS BECAME MORE FREQUENT AS JUNE WORE ON. MEASURABLE RAIN FELL ON HALF THE DAYS OF THE MONTH...SIGNIFICANTLY MORE THAN THE LONG TERM AVERAGE OF 11 DAYS WITH 0.01 INCHES OR MORE OF RAIN. AS IS TYPICAL FOR JUNE...DAILY RAINFALL VARIED WIDELY IN THE GREATER FAIRBANKS AREA...THOUGH MONTHLY TOTALS WERE SIMILAR. THE AIRPORT MEASURED 1.77 INCHES FOR JUNE...BY FAR THE LOWEST MONTHLY TOTAL IN THE AREA. HOWEVER...THIS WAS STILL ABOUT A THIRD OF AN INCH ABOVE NORMAL. MOST OF THE RAIN FELL DURING THE LAST WEEK OF THE MONTH. OTHER JUNE TOTALS INCLUDE...
GOLDSTREAM CREEK.................2.01 INCHES
UNIVERSITY WEST..................2.15 INCHES
UAF WEST RIDGE...................2.58 INCHES
GILMORE CREEK....................2.60 INCHES
SALCHA...........................2.61 INCHES
NORTH POLE.......................2.91 INCHES
EAST FARMERS LOOP................2.96 INCHES
40 MILE CHENA HOT SPRINGS ROAD...3.95 INCHES

MUCH HIGHER MONTHLY RAINFALL TOTALS WERE MEASURED AT HIGHER ELEVATIONS IN THE UPPER CHENA BASIN...INCLUDING 6.24 INCHES AT MUNSON RIDGE AND 4.53 INCHES AT MONUMENT CREEK NEAR CHENA HOT SPRINGS. HEAVY RAINS ALSO FELL IN THE UPPER SALCHA RIVER BASIN...WHICH PUSHED THE SALCHA RIVER UP TO NEAR FLOOD STAGE ON JUNE 26TH. FARTHER EAST...THERE WAS FLOODING ON THE GOODPASTER RIVER A COUPLE DAYS EARLIER.

LOOKING AHEAD TO JULY...THIS IS OFTEN THE WARMEST MONTH OF THE YEAR IN FAIRBANKS. THE AVERAGE HIGH TEMPERATURE IS 72 DEGREES AND THE AVERAGE LOW 53 DEGREES. IN THE PAST 106 YEARS...JULY TEMPERATURES HAVE RANGED FROM 99 DEGREES IN 1919 TO A LOW OF 30 DEGREES IN 1905. AVERAGE RAINFALL FOR THE MONTH IS 1.73 INCHES..AND MONTH THE WETTEST AND DRIEST JULYS OF RECORD HAVE OCCURRED IN THE PAST TEN YEARS. JULY IS THE ONLY MONTH OF THE YEAR THAT IT HAS NOT SNOWED IN FAIRBANKS. POSSIBLE SUNSHINE DECREASES FROM 21 HOURS AND 27 MINUTES ON THE FIRST TO 18 HOURS AND 18 MINUTES ON THE 31ST. DURING THE LAST WEEK OF THE MONTH IT WILL AGAIN BECOME DARK ENOUGH FOR THE BRIGHTEST STARS TO BE BRIEFLY VISIBLE.

Lightning Climatology: Most strikes in one day

I've been working on developing a climatology of lightning strikes in Alaska using the historical lightning data available on the Alaska Fire Service web site (23 years of data). Here is the plot of the most strikes in one day in the state, from June 15, 2005: just under 8900 strikes. Following long standing practice, a strike day runs from 6am to 6am, so this plots strikes from 6am ADT June 15th to 6am June 16th. It is ironic that on this, the max strike day of record, there are virtually no strikes over the Tanana-Yukon Uplands, the area of the state with highest climatological frequency of lightning.

Barrow Snow

The UAF Sea Ice Group's Barrow webcam is back up, just in time to show a skiff of snow accumulating Friday morning. Trace amounts of snow in Barrow in July are not unusual. There is still some sea ice left too. The broken nature of the sea ice for July one is typical for the "new normal", though 30 years ago this photo would have been more representative of late July or early August

Fairbanks Soaker

From Fairbanks northward there has been a decent amount of rain the past few days. Nothing extreme, but enough, over a long enough period of time to soak in and help boast soil moisture. Coming right before the 4th of July holiday weekend, the timing is good too. Here are some rough totals the past five days:

Angel Creek RAWS: 0.7 inches
Fairbanks Airport: 0.8 inches
Eielson AFB: 0.8 inches
Keystone Ridge: 1.4 inches
Munson Ridge: 2.3 inches
Chatanika River RAWS: 3.2 inches

As of this morning's situation report from the Alaska Fire Service, 262600 acres have burned in Alaska thus far this season. There's potentially still six weeks left in the active fire season, but a good soaking is a good way to be going into July

Midnight Sun

FAA webcam shot from Prudhoe Bay, looking north at 201AM, which is almost exactly solar midnight.

Ice View from Saturday

Here is a MODIS image from the Terra satellite of the northern quarter of Alaska and adjacent oceans, taken Saturday. This nicely shows the edge of pack ice, some shorefast ice and ice in some of the bigger lakes north of 71N. Oh yeah, and lots of green too!

Deep Storm in the Western Aleutians

This analysis from the Ocean Prediction Center valid 10 AM Saturday shows the strong storm that is now in the southern Bering Sea. A pretty deep low for late June, it brought gusts to around 50 mph at Shemya early Saturday, and similar winds Sunday morning to Adak.

Big Lightning Day

There were more than 4300 lightning strikes Saturday across a fairly narrow across the Interior stretching from the upper Tanana Valley to the upper Kobuk valley. In spite of deep moisture, rainfall amounts were mostly underwhelming, generally a quarter inch or less, though there were isolated reports of around an inch of rain. At Keystone Ridge, it thundered intermittently from 6pm to 11pm.

Rains in the Eastern Interior

Eastern Interior Alaska was soaked Wednesday night and Thursday with widespread moderate to heavy rain. Above are hydrographs from the Fortymile River at the Taylor Highway and Birch Creek near 101 Mile Steese Highway. The Fortymile is about to go over flood stage. The much smaller Birch Creek has already crested.

Total rainfall Wednesday and Thursday include…

Ben Creek RAWS (above Coal Creek on the Yukon River): 2.58 inches
Birch Creek RAWS (east of central above the Steese Highway Bridge): 1.43 inches
Chicken RAWS: 1.07 inches
Preacher Creek RAWS (northeast of Circle City): 0.81 inches

The rain got about as far west as the east side of Fairbanks, with most places east of town receiving around a tenth of an inch of rain early Thursday evening. There was no appreciable rain from Fairbanks westward.