Climatological Report (Monthly)
Issued by NWS Juneau, AK

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000
CXAK57 PAJK 030124
CLMAJK
NATIONAL WEATHER SERVICE JUNEAU AK
358 PM AKST FRI FEB 02 2024

...................................

...THE JUNEAU CLIMATE SUMMARY FOR THE MONTH OF JANUARY 2024...

CLIMATE NORMAL PERIOD: 1991 TO 2020
CLIMATE RECORD PERIOD: 1936 TO 2024

WEATHER         OBSERVED          NORMAL  DEPART   LAST YEAR`S
                VALUE   DATE(S)   VALUE   FROM     VALUE
                                          NORMAL
..............................................................
TEMPERATURE (F)
RECORD
 HIGH             60   01/20/1942
 LOW             -22   01/12/1972
HIGHEST           48   01/29         43       5
LOWEST             2   01/12          2       0
AVG. MAXIMUM    32.4               33.1    -0.7
AVG. MINIMUM    23.8               23.8     0.0
MEAN            28.1               28.5    -0.4
DAYS MAX >= 90     0                0.0     0.0
DAYS MAX <= 32    14               12.0     2.0
DAYS MIN <= 32    27               22.7     4.3
DAYS MIN <= 0      0                0.9    -0.9

PRECIPITATION (INCHES)
RECORD
 MAXIMUM       12.29   2022
 MINIMUM        0.94   1969
TOTALS          9.68               6.02    3.66
DAILY AVG.      0.31               0.19    0.12
DAYS >= .01       21               20.4     0.6
DAYS >= .10       16               13.4     2.6
DAYS >= .50        6                3.9     2.1
DAYS >= 1.00       3                1.1     1.9
GREATEST
 24 HR. TOTAL   1.84   01/29 TO 01/29

SNOWFALL (INCHES)
RECORDS
 TOTAL          75.2
TOTALS          76.8R              24.5    52.3      5.7
SINCE 7/1       96.5               57.3    39.2
DAYS >= TRACE     17               10.3     6.7       11
DAYS >= 1.0       11                6.2     4.8        3

DEGREE DAYS
HEATING TOTAL   1135               1133       2
 SINCE 7/1      4228               4831    -603
COOLING TOTAL      0                  0       0
 SINCE 1/1         0                  0       0

FREEZE DATES
RECORD
 EARLIEST     08/24/1969
 LATEST       06/13/1965
EARLIEST                        10/21
LATEST                          05/05
..............................................................

WIND (MPH)
AVERAGE WIND SPEED              7.2
HIGHEST WIND SPEED/DIRECTION    40/110    DATE  01/29
HIGHEST GUST SPEED/DIRECTION    57/120    DATE  01/29


WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               1
HEAVY RAIN                0     RAIN                       2
LIGHT RAIN               12     FREEZING RAIN              0
LT FREEZING RAIN          4     HAIL                       0
HEAVY SNOW                0     SNOW                       5
LIGHT SNOW               17     SLEET                      0
FOG                      24     FOG W/VIS <= 1/4 MILE      6
HAZE                      0

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

$$

...EL NINO WINTER OR NOT, JANUARY WAS COLDER THAN NORMAL WITH OVER 3
TIMES THE NORMAL JANUARY SNOWFALL IN SOME LOCATIONS...

The middle of the month saw a multi-day snow event from 12 to 15
January. The setup featured very cold surface airmass with
widespread temperatures in the single digits or, in some cases below
zero Farehheit. The moisture laden weather system moved in and
produced heavy snow over many locations. In Juneau, the 3-day snow
total at the airport was 28.3 inches, which was 4th place for a 3-
day event in the month of January and 15th place overall for any
month. Other notable facts: Juneau reached its month normal snowfall
for January before the middle of the month during this event.
Additionally, snow ratios for Southeast Alaska are typically 5:1 or
10:1, meaning that 5 (or 10) inches of snow equates to 1 inch of
liquid water. At the beginning of this event while temperatures were
still bitterly cold, the snow ratio at the forecast office in Juneau
was a phenomenal 55:1 - thats 55 inches of snow for every 1 inch of
liquid. What do you think about THAT, NWS Boulder!

One week later, beginning on the 21st of January, Southeast Alaska
experienced another multi-day snow event. By the end of the 24th of
January, Juneau recorded another 35.3 inches of snow and snow depth
at the airport maxed out at 38 inches. In the back of the Mendenhall
Valley, the forecast office recorded 30.9 inches of new snow with a
maximum depth of 40 inches at midnight on the 24th. The main
difference between these two snow events had to do with the very
different snow ratios. While the first event featured very light and
fluffy powder that could be easily cleared of driveways and side
walks with a household leaf blower, the water content of that snow
was relatively little. The second event featured much lower snow
ratios and higher liquid water equivalent, which made snow and berm
removal much more difficult.

With over 3 feet of snow on the ground (and rooftops) after the
second snow event, temperatures began warming to above normal
temperatures with overnight lows above freezing for the last week of
the month. Additionally, a significant abount of rain fell on the
snowpack, causing the snow water equivalent, or SWE to rise to over
6 inches, meaning that horizontal surfaces were bearing a snow load
of over 30 pounds persquare foot. Fortunately, very few collapsed
roofs were reported and numerous residents took the proactive
measure of cleaning their roofs "just in case". By the end of the
month, SWE and snow loading on roofs was no longer a concern, as the
rain of the last few days had eliminated much of the snow pack and
most of the rooftop snow. All just in time for a third round of
significant snowfall that began on the evening of the 31st of
January. By midnight, 6.8 inches of new snow had fallen at the
Juneau airport, raising the January monthly total to 76.8 inches and
claiming the title as snowiest January on record. This was also the
second snowiest of any month on record.

Fritsch
$$


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