Alaska Statewide Climate Summary August 2020

August 2020 HIGHLIGHTS

- VERY WARM AUGUST THROUGHOUT THE STATE WITH ST. PAUL ISLAND SETTING NEW RECORD HIGH AVERAGE TEMPERATURE.

- VERY WET AUGUST IN JUNEAU AND KETCHIKAN WITH DROUGHT CONDITIONS ON THE WEST COAST.

o KOTZEBUE AND UTQIAGVIK EXTREMELY DRY. o KODIAK DRIER THAN TYPICAL CONDITIONS FOR THE SUMMER.

- OVERALL ARCTIC SEA ICE IS AT THE SECOND LOWEST EXTENT SINCE RECORD BEGAN IN 1979.

The following report provides an overview of the August weather. The report is based on data from selected weather stations throughout the state of Alaska. “Departure from normal” refers to the climatological average over the 1981-2010 period.

Temperature

Temperatures across Alaska were warmer than average for 90% of the locations reporting data (Figure 1; Table 1). The only locations cooler than average were Juneau (-0.8 °F) and Ketchikan (-0.7 °F). The largest deviations from normal were St. Paul Island (+5.7 °F), Bettles (+4.8 °F), Fairbanks (+3.6 °F), McGrath (+3.1 °F) and Utqiaġvik (+2.9 °F). Figure 2 shows temperature patterns at St. Paul Island since the beginning of 2020. The location has consistently shown higher than average temperatures since mid-March 2020 and, for the month of August, the most warming of all recorded locations.

Highest mean daily records were broken in the following locations: on August 20th in Kodiak, increasing 0.5 °F from the previous record of 63.5 °F set in 1995; on August 17th, in Kotzebue, increasing 0.5 °F from the previous record of 62.5 °F set in 2007; for one-third of the month of

August at St. Paul Island (see Appendix for daily details); on August 19th in Talkeetna, increasing 0.5 °F from the previous record of 61.5 °F set in 2004; and on August 21st in Yakutat, increasing 1.5 °F from the previous record of 60 °F set in 1923. The lowest minimum daily record was broken in Cold Bay on August 27th from 39°F in 1994 to 38 °F in 2020 and in Ketchikan on August 30th from 55 °F in 1924 to 54 °F in 2020. All other values (e.g., highest minimum and maximum daily) and dates are listed in Tables A1, A2 and A3 in the appendix.

Figure 1: Monthly mean temperature departure from normal, August 2020.

Table 1: Mean monthly air temperature, normal (1981-2010) and departure for selected stations throughout the state, August 2020. Red is above average; blue is below average.

Station Observed (ºF) Normal (ºF) Departure (ºF) Anchorage 58.8 56.7 2.1 Bethel 55.5 53.5 2.0 Bettles 57.3 52.5 4.8 Cold Bay 53.0 52.1 0.9 Delta Junction 56.2 54.8 1.2 Fairbanks 59.7 56.1 3.6 Gulkana 54.6 53.5 1.0 Homer 55.1 53.9 1.2 Juneau 55.0 55.8 -0.8 Ketchikan 57.3 58.0 -0.7

King Salmon 55.9 54.6 1.3 Kodiak 57.6 55.2 2.4 Kotzebue 53.9 51.7 2.2 McGrath 57.7 54.6 3.1 Nome 51.3 50.1 1.2 St. Paul Island 54.6 48.9 5.7 Talkeetna 58.7 56.7 2.0 Utqiaġvik 41.9 39.0 2.9 Yakutat 54.6 53.9 0.8

Figure 2: St. Paul Island daily mean temperature departures from normal (1981-2010) in 2020. Red and blue bars represent positive and negative temperature departures. Grey line represents the mean normal temperature, red and blue lines represent respectively the historic highest and lowest records of mean daily temperature. Note the above average temperatures from mid-March until present, with continuous positive departures in the summer (June – August).

Daily mean temperature departures (Figure 3) show above average temperatures for all locations except Juneau and Ketchikan, with Bettles, Fairbanks, Kotzebue, McGrath, St. Paul Island and Utqiaġvik showing the greatest consistently high temperatures for the majority of days in August.

Figure 3: Daily mean temperature departures for each day in August 2020, at the selected stations.

Precipitation

Precipitation in August was below average in 63% of locations and above average in the rest (Figure 4). Areas receiving the most rain include Ketchikan (an impressive 22.8 inches, or, 233% of normal), Juneau (10.3 inches, or, 179% of normal) and Gulkana (2.5 inches, or, 139% of normal) (Table 2).

Figure 4: Monthly precipitation sums expressed as percent of normal (1981-2010), August 2020.

Table 2: Monthly precipitation sum, normal (1981-2010) and departure expressed as a percentage of the normal (1981-2010) for selected stations throughout the state, August 2020.

Station Precipitation (in) Normal (in) % of normal Anchorage 3.2 3.2 98.8 Bethel 2.2 3.3 68.6 Bettles 1.6 2.6 61.0 Cold Bay 2.7 3.7 72.6 Delta Junction 2.0 1.9 103.7 Fairbanks 2.1 1.9 112.8 Gulkana 2.5 1.8 139.4 Homer 2.4 2.3 103.0 Juneau 10.3 5.7 179.1 Ketchikan 22.8 9.8 232.9 King Salmon 3.1 3.0 106.4 Kodiak 2.7 4.6 59.2 Kotzebue 0.4 2.2 16.1 McGrath 2.2 2.8 77.9 Nome 1.1 3.2 33.9

St. Paul Island 2.1 3.1 69.7 Talkeetna 3.6 5.1 71.4 Utqiaġvik 0.2 1.1 21.9 Yakutat 13.7 14.1 97.2

Notably, Ketchikan received significantly more precipitation than normal (Figures 4, 5), as has been the case the entire summer. Areas receiving much less precipitation than normal include Kotzebue (0.4 inches, or 16% of normal), Nome (1.1 inches, or 34% of normal) and Utqiaġvik (0.2 inches, or, 22% of normal). Kodiak also stands out for receiving less precipitation than normal: only 2.7 inches versus 4.6 inches, or, 59% of normal. Overall, Kotzebue received the least amount of precipitation for the month.

Figure 5: Monthly precipitation sums for August 2020 at the selected stations compared to the normal (1981-2010), in inches.

Drought Conditions

Below normal precipitation in over half of the locations from which data were collected reveal drought conditions (rated D0: abnormally dry) in the south-central and western part of the state (Figure 6). Kotzebue, at 16% of normal precipitation for this time of year (Figure 4; Table 2) is

under moderate drought conditions, as is Kodiak (D1, both seen as pale orange in Figure 6). The figure below has been produced through a collaboration of the USDA, NOAA and the National Drought Mitigation Center.

Figure 6: U.S. Drought Monitor map for Alaska, updated on September 1, 2020. The table on the right shows the percent area affected by different categories of drought intensity. Figures and data produced and released by the U.S. Drought Monitor, a partnership between the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration (https://droughtmonitor.unl.edu).

Wildfire Activity

For the month of August 2020, the state of Alaska continued to see minimal wildfire activity (Figure 7), with a near-even split of fires caused by lightning and human activity. A total of 181,225 acres (up 1500 acres from last month) have burned in Alaska from the start of 2020 through August 31st, 2020. This is in great contrast to the contiguous US, where the west coast is being ravaged by record-breaking fire activity.

Please check our UAFSmoke website at http://smoke.alaska.edu for updated fire information. UAFSmoke shows current wildfire status information and up to 72 hours forecast of concentration of black carbon and particulate matter included in wildfire smoke.

Figure 7: Map of current wildfires updated on August 12, 2020 from the UAFSmoke website (http://smoke.alaska.edu). Data are from the Alaska Interagency Coordination Center. Circles represent the size, but not the shape, of the fire. Fires that have not been updated in more than a week are shown with grey markers.

Arctic Sea Ice

From July 30th to August 6th, 2020, sea ice decreased by a rate of 4.23%, down to 5.812 million km2 from 6.069 million km2 for the week, showing some slow-down in melt. While still in a record low, the 2020 extent, up to this point, was still above the 2012 and 2018 marks. From August 6th to August 13th, 2020, the sea ice decreased by a rate of 7.38%, down to 5.383 million km2 from 5.812 million km2. Following this period of slow August ice loss, the pace quickened during the middle of the month as areas of low ice concentration melted away and temperatures were above average over much of the Arctic Ocean. From August 13th to August 20th, 2020, the rate of sea ice loss decreased by a double-digit rate of 12.61% from the level the previous week of 5.383 million km2 to 4.704 million km2. From August 20th to August 27th, 2020, sea ice decreased by a lower rate – only 7.25% - going from 4.704 million km2 to 4.363 million km2, taking up a 2nd place position in low sea ice extent, above the all-time low set in 2012 (green line) and just below the

2018 (gold) line. Sea ice melt is slowing, given the onset of autumn in the Arctic and so, with only a few weeks left in the melt season, the jury is still out whether this will be the record-setting year. Surpassing the low extent of sea ice in 2012 seems a bit unlikely at this point, but then that's why we look to the data. Pictured is the sea ice extent up to this date (Figure 8) and sea ice concentration for the month of August (Figure 9).

Figure 8: Time series of daily Arctic sea ice extent. This year’s data (light blue) are updated until August 27, 2020. The median sea ice extent for the 1981-2010 reference period is depicted in blue. Specific years are highlighted in colors. Plot Compiled by: Howard J. Diamond, PhD; Climate Science Program Manager at NOAA's Air Resources Laboratory Data Source: National Snow & Ice Data Center (NSIDC; https://nsidc.org/).

Figure 9: Monthly Arctic Sea Ice concentration for August 2020. Magenta line is outline of the 30-year (1981-2010) median extent for that month. Image: NSIDC (nsidc.org)

Newsworthy Information

Unalaska recorded 120 mph winds when a rapidly developing storm moved from the North Pacific and across the Eastern Aleutians. This is the strongest storm to affect Alaska during the month of August on record: https://www.alaskapublic.org/2020/08/31/unalaska-records-120-mph-winds-during-record-breaking-august-storm/

Ketchikan unofficially broke its summer rainfall record with 47 inches in the months of June, July and August. Of the 90 or so days from June through August, Ketchikan saw 68 days with measurable rainfall. The city’s previous record, 67 days, was set in 1933 and last tied in 1966:

https://www.alaskapublic.org/2020/08/31/merciless-rain-in-southeast-alaska-breaks-records-dampens-spirits/ The National Weather Service records 2020 as a record year for rainfall in Juneau. Juneau International Airport secured the 5th wettest meteorological summer, measuring 19.89 inches of precipitation from June – August: https://www.kinyradio.com/news/news-of-the-north/nws-2020-marks-a-record-for-summer-rainfall/ Indigenous Alaskans demand a voice in research on warming as major erosion and decline in salmon, a major source of sustenance, threaten livelihoods: https://science.sciencemag.org/content/369/6509/1284.full Alaska’s salmon are shrinking and climate change may be to blame: https://www.reuters.com/article/us-environment-salmon-alaska/alaskas-salmon-are-shrinking-and-climate-change-may-be-to-blame-idUSKBN25G10E

Unprecedented fires in the Russian Arctic release record quantities of carbon dioxide, more than the entirety of 2019: https://bellona.org/news/climate-change/2020-09-fires-in-russian-arctic-release-record-quantities-of-carbon-dioxide-studies-say

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Appendix

Table A1: August 2020 daily records of mean daily temperature, i.e. highest/lowest values of mean daily temperature ever recorded on specific days. Records are computed since the beginning of the respective time series. Only highest records were set this month.

Highest Mean Daily Temperature on Record Station Date New Record (ºF) Year of Old Record Old Record (ºF) Kodiak 2020-08-20 64.0 1995 63.5 Kotzebue 2020-08-17 63.0 2007 62.5 St. Paul Island 2020-08-03 58.0 2005 54.5 St. Paul Island 2020-08-09 54.5 2014 53.5 St. Paul Island 2020-08-12 55.0 2014 54.0 St. Paul Island 2020-08-13 58.0 2016 55.5 St. Paul Island 2020-08-14 56.5 2014 55.0 St. Paul Island 2020-08-18 56.0 2014 54.0 St. Paul Island 2020-08-23 56.5 2004 53.5 St. Paul Island 2020-08-24 55.5 2004 54.0 St. Paul Island 2020-08-27 55.0 1977 53.5 St. Paul Island 2020-08-30 56.5 2019 54.0 Talkeetna 2020-08-19 62.0 2004 61.5 Yakutat 2020-08-21 61.5 1923 60.0

Table A2: August 2020 daily records of minimum daily temperature, i.e. highest/lowest values of minimum daily temperature ever recorded on specific days. Records are computed since the beginning of the respective time series. Two lowest records and multiple highest records were set this month.

Highest Minimum Daily Temperature on Record Station Date New Record (ºF) Year of Old Record Old Record (ºF) Anchorage 2020-08-23 58 1977 57 Bettles 2020-08-27 51 1957 49 Juneau 2020-08-01 57 2009 56 St. Paul Island 2020-08-03 54 2005 52 St. Paul Island 2020-08-11 53 2014 51 St. Paul Island 2020-08-12 53 2014 51 St. Paul Island 2020-08-13 53 2016 52 St. Paul Island 2020-08-16 52 2005 51 St. Paul Island 2020-08-17 51 1977 50 St. Paul Island 2020-08-18 53 1996 50

St. Paul Island 2020-08-21 53 2014 52 St. Paul Island 2020-08-23 53 2014 52 St. Paul Island 2020-08-29 53 2016 52 St. Paul Island 2020-08-30 53 2019 51 Talkeetna 2020-08-23 55 1963 54 Lowest Minimum Daily Temperature on Record Station Date New Record (ºF) Year of Old Record Old Record (ºF) Cold Bay 2020-08-27 38 1994 39 Ketchikan 2020-08-30 54 1924 55

Table A3: August 2020 daily records of maximum daily temperature, i.e. highest/lowest values of maximum daily temperature ever recorded on specific days. Records are computed since the beginning of the respective time series. Only highest records were set this month.

Highest Maximum Daily Temperature on Record Station Date New Record (ºF) Year of Old Record Old Record (ºF) Anchorage 2020-08-15 78 2019 77 Bethel 2020-08-18 75 2004 74 Kodiak 2020-08-20 76 1953 72 Kotzebue 2020-08-17 73 2007 71 St. Paul Island 2020-08-03 62 1993 58 St. Paul Island 2020-08-09 59 1990 57 St. Paul Island 2020-08-14 66 2012 63 St. Paul Island 2020-08-18 59 2014 58 St. Paul Island 2020-08-19 60 2014 58 St. Paul Island 2020-08-23 60 1977 59 St. Paul Island 2020-08-24 59 1989 58 St. Paul Island 2020-08-30 60 2016 58