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