Sunday, February 2, 2014

Fairbanks Temperature Update

The chart below shows recent daily mean temperatures in Fairbanks, compared to the 1981-2010 normal; the gray lines show the +/- 1 standard deviation range around the daily normal values.  The see-saw pattern that began in mid-November ended abruptly in mid-January, giving way to very unusual warmth that persisted for most of the rest of the month.


Below is the January climate summary, courtesy of NWS Fairbanks.  Note that the summary says that the 45 °F on the 24th was the "warmest temperature recorded at the airport during the month of January" - this refers to January 2014, not the all-time record for January, which is 52 °F (Jan 16, 2009).




PUBLIC INFORMATION STATEMENT...CORRECTED
NATIONAL WEATHER SERVICE FAIRBANKS AK
624 AM AKST SAT FEB 1 2014

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

JANUARY 2014 WAS EXCEPTIONALLY WARM AND DRY IN FAIRBANKS WITH THE
AVERAGE TEMPERATURE FALLING BELOW NORMAL ON ONLY 4 DAYS...HOWEVER
WITH THE WARM TEMPERATURES CAME TWO FREEZING RAIN EVENTS OVER A 3
DAY PERIOD THAT CREATED HAZARDOUS DRIVING CONDITIONS AND CLOSED
MANY LOCAL SCHOOLS FOR TWO DAYS.

JANUARY STARTED WARM WITH AVERAGE TEMPERATURES 10 TO 20 DEGREES
ABOVE NORMAL FOR THE FIRST 9 DAYS...HOWEVER TEMPERATURES PLUMMETED
FROM 15 ABOVE ON THE 8TH TO 41 BELOW ON THE 12TH AND 13TH. 41
BELOW WAS THE COLDEST TEMPERATURE RECORDED AT THE AIRPORT DURING
THE MONTH OF JANUARY.

WARM TEMPERATURES RETURNED AGAIN TO THE INTERIOR BY MID MONTH.
A HIGH PRESSURE RIDGE ALOFT THAT STRETCHED FROM NEAR HAWAII TO
NORTHERN ALASKA ALLOWED A PROLONGED CHINOOK EVENT THAT LASTED
FROM AROUND THE 20TH TO THE 28TH OF JANUARY TO DEVELOP OVER THE
INTERIOR. AVERAGE TEMPERATURES WERE 20 TO 40 DEGREES ABOVE NORMAL
THROUGH THIS PERIOD. THE TEMPERATURE SOARED TO 45 DEGREES AT THE
FAIRBANKS AIRPORT ON THE 24TH. THIS WAS THE WARMEST TEMPERATURE
RECORDED AT THE AIRPORT DURING THE MONTH OF JANUARY. THE WARM
TEMPERATURES WERE NOT UNIQUE TO FAIRBANKS AS SEVERAL SITES ACROSS
THE INTERIOR SET RECORDS INCLUDING AN ALL TIME RECORD HIGH
TEMPERATURE FOR THE MONTH OF JANUARY OF 52 DEGREES AT DENALI
NATIONAL PARK HEADQUARTERS ON THE 26TH.

THE AVERAGE HIGH TEMPERATURE FOR THE MONTH OF JANUARY AT THE
FAIRBANKS AIRPORT WAS 16.4 DEGREES ABOVE ZERO WHICH IS 15.3
DEGREES ABOVE THE NORMAL HIGH TEMPERATURE OF 1.1 DEGREES ABOVE
ZERO. THIS RANKS AS THE 7TH WARMEST OF 106 YEARS OF RECORD. THE
AVERAGE LOW TEMPERATURE FOR THE MONTH OF JANUARY AT THE FAIRBANKS
AIRPORT WAS 1.1 DEGREES BELOW ZERO WHICH IS 15.8 DEGREES ABOVE
THE NORMAL LOW TEMPERATURE OF 16.9 DEGREES BELOW ZERO. THIS RANKS
AS THE 7TH WARMEST OF THE 107 YEARS OF RECORD. THE AVERAGE
TEMPERATURE WAS 7.6 DEGREES ABOVE WHICH WAS 15.5 DEGREES ABOVE THE
NORMAL AVERAGE TEMPERATURE OF 7.9 DEGREES BELOW.

0.22 INCH OF PRECIPITATION FELL AT THE AIRPORT DURING THE MONTH
OF JANUARY WHICH IS 0.36 INCH BELOW THE NORMAL PRECIPITATION OF
0.58 INCH. THIS RANKS AS THE 20TH DRIEST OUT OF 103 YEARS OF
RECORD. ONLY 2.5 INCHES OF SNOW FELL AT THE FAIRBANKS AIRPORT
WHICH IS 7.8 INCHES BELOW THE NORMAL JANUARY SNOW FALL OF 10.3
INCHES. WELL ABOVE NORMAL TEMPERATURES ALLOWED A HIGH PROPORTION
OF THE PRECIPITATION THAT FELL TO FALL IN LIQUID FORM FURTHER
REDUCING THE AMOUNT OF SNOW FALL. THE 2.5 INCHES OF SNOW THAT FELL
RANKS AS THE 12TH LOWEST AMOUNT FOR A JANUARY TOTAL SNOW FALL.

LOOKING AHEAD TO FEBRUARY WITH THE CLIMATOLOGICALLY COLDEST PART
OF WINTER BEHIND...AND AVAILABLE DAY LIGHT INCREASING AT NEARLY
SEVEN MINUTES PER DAY...A NOTICEABLE DIURNAL TEMPERATURE RANGE
WILL BE FELT...ESPECIALLY BY THE END OF THE MONTH. THE AVERAGE
HIGH TEMPERATURE AT THE FAIRBANKS AIRPORT INCREASES FROM 3 DEGREES
ABOVE ON THE 1ST TO 17 DEGREES ABOVE ON THE 28TH. THE AVERAGE LOW
TEMPERATURE INCREASES FROM 16 BELOW ON THE 1ST TO 10 BELOW ON THE
28TH. TEMPERATURES IN FEBRUARY HAVE RANGED FROM 50 ABOVE IN 1943
TO 58 BELOW IN 1947 AND MOST RECENTLY IN 1993. THE NORMAL
PRECIPITATION FOR FEBRUARY IS 0.42 INCHES. AVERAGE SNOWFALL IN
FEBRUARY IS 8.1 INCHES. AVAILABLE SUNSHINE INCREASES FROM 6 HOURS
AND 59 MINUTES ON THE FIRST TO 10 HOURS AND 2 MINUTES ON THE 28TH.

THE OUTLOOK FOR FAIRBANKS FOR FEBRUARY FROM THE CLIMATE PREDICTION
CENTER CALLS FOR EQUAL CHANCES OF ABOVE...NEAR NORMAL OR BELOW
NORMAL TEMPERATURES. THE CLIMATE PREDICTION CENTER IS ALSO
CALLING FOR EQUAL CHANCES FOR ABOVE NORMAL...NEAR NORMAL OR BELOW
NORMAL PRECIPITATION.

OBSERVED LAST MONTH...01/2014

                         OBSERVED   RANK
AVG MAX TEMP (F)             16.4   7TH WARMEST OF 106 YEARS
AVG MIN TEMP (F)             -1.1   7TH WARMEST OF 107 YEARS
AVG TEMP (F)                  7.6   7TH WARMEST OF 106 YEARS
TOTAL PRECIPITATION (IN)      0.22 20TH DRIEST OF 103 YEARS TOTAL
SNOW (IN)                     2.50 93RD SNOWIEST OF 104 YEARS

$$

CCC

5 comments:

  1. Looks like cold and crisp is coming:

    http://www.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/arT2mMonInd1.gif

    At least the photoperiod and insolation are increasing to help moderate the daily temps.

    Gary

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  2. Given the winter 2013-14 info shown above (relatively warm so far), here's a link to one of the consequences of all that:

    http://pafg.arh.noaa.gov/wmofcst_pf.php?wmo=NOAK49PAFG&type=pub

    and the source site:

    http://aprfc.arh.noaa.gov/php/icedb/ak_it_color.php (dig around, there's more)

    Ice depth can be a function of residual heat before freeze up, time of ice formation and subsequent time period, wind events during ice formation, air temperatures, and snow cover through the winter. Any penetration of the ice cover by liquid water from below can add to localized ice thickness through water overflow conditions and the melting of surface snow.

    Gary





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    Replies
    1. Thanks Gary. The first link you sent is missing a few letters on the end. Here is the full address: http://pafg.arh.noaa.gov/wmofcst.php?wmo=NOAK49PAFG&type=public

      I have noticed the last few years that the Chena River at Pike's seems to get 10"-20" thick early in the season and then thens out in February. Any ideas why?

      Here in Southcentral most of our snow is gone and now that it is very cold (for us) the lake ice and soil frost penetration are really going deep. Someone at the Anchorage NWS office e-mailed me that a soil site in the Matanuska Valley had their frost depth increase from 10" to 31" since late January.

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    2. Not exactly sure Brian about Pike's ice, but once frozen that stretch of the Chena gets well packed by snow machines, foot traffic, and vehicles crossing the creek to get to nearby roads.

      Any fluffy insulating snow cover is soon reduced to hard pack. Beneath the ice, the water warmed by the power plant upstream flows with relative warmth compared with water upstream of the plant. Waterfowl can reside year round in the open stretches.

      So it may freeze early to depth, then thin via lack of insulation and increased input of warm outflow upstream during cold weather. Best guess.

      With Spring warmth, careless motorists that cross that area often succeed in determining the depth of the river below the ice.

      Gary

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    3. Another thought re Pike's ice...at some point after freeze-up the volume of water flowing in the lower Chena River likely declines then stabilizes. Gradual reduction of input from groundwater sources and tributaries as winter progresses would be the probable cause.

      As cold increases, the Aurora Energy plant (http://www.alaskapower.org/pdf/BukiWright.pdf) would increase it's heated effluent to meet the output demand for its services. That, coupled with a decrease in flow volume of cold water in the adjacent river, probably increases the water temp downstream leading to a reduction in the thickness of ice and open areas of water.

      How's that for a pre-coffee SWAG?

      Gary

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