Observation by Jeffrey Luther:
On 6/29/2021 and 6/30/2021 there was flooding that caused significant erosion. These are the results from last week's flood from all the rain in the Brooks Range, I need to get to the well island to look for my 30ft markers I made there.
On July 12, 2021, Jeffrey Luther added the following record, providing monitoring notes from May12 to July 8, 2021:
BEFORE FLOOD:
May 12 - before breakup I made the measurements on the banks
May 16 - after 1st high water no erosion yet
May 28 - 2ft 5 inches lost towards Airport
May 28 - 1ft 1 inch lost @ old landfill
June 8 - no changes on both places (undercutting)
June 15 - 2ft 7 inches lost towards airport
June 15 - 2ft 1 inch lost @ old landfill
June 24 - 2ft 10 inches towards airport
June 24 - 2ft 8 inches @ old landfill
July 8 (AFTER FLOOD) - 10ft towards airport, 12ft 3 inches @ old landfill
July 13 - 11ft towards airport, still same at old landfill 12'3"
On July 16, 2021, Jeffrey Luther wrote:
Seven more feet eroded from the 13th to today towards airport, I didn't think it would go that fast, otherwise I would do daily measurements. There was a lot of undercut at the airport area bank, looks like a small shore below there now, water is dropping, so the erosion might be done for the year unless we have another flood.
July 16 - 18ft towards airport, 12ft 3inches @ old landfill
2020 + 2021 erosion totals: 24ft towards airport, 28ft 11inches @ old landfill
Rick Thoman, Climate Scientist at the Alaska Center for Climate Assessment and Policy, writes:
The last days of June brought exceptionally heavy rain to the northern half of Northwest Arctic Borough and parts of the western North Slope. A weather front stalled along the Brooks Range as a series of low pressure systems moved from northeast Russia across the Chukchi Sea and into Alaska. As you can see on the attached graphic, total rainfall June 28 to 30 from automated weather stations in the Noatak valley were generally near or above two inches (I suspect the FAA weather station amount at Noatak is too low). Red Dog Mine reported more than 4 inches of rain, the highest three-day rainfall total since August 2016. While this region occasionally receives rains of this amount, that nearly always is in late July or August. The information from Mr. Luther is vital to documenting this very unusual event.
Crane Johnson with the NSW River Forecast Center writes:
I'll ask someone in our office to take a look at this event and see if there is anything we can add. The photos only show erosion, was there flooding as well? Here is a page that describes the NWS definition of flash flooding It is important for us to reserve that term for 'flash flood' events such as dam breaks, torrential rains resulting in flooding in 3-6 hours.
On July 14, Crane added:
I shared this with our Northern Region Hydrologist to see if they have anything to add. Great observation and excellent way to document erosion. We would be interested in potentially adding an observer on the Noatak River for daily river observations. We are trying to expand our network of daily community river observers, especially on systems that are completely ungaged. Rick provides some great background information on the weather leading up to this erosion event.
On July 14, Jeffrey replied:
Let me know what needs to be done from our end to see if an observer can be added up here.
Comment by Joy Britt, ANTHC: The ANTHC Contamination Support Program is managing a permafrost monitoring project and will be traveling to Noatak in late Summer/ early Fall 2021 to conduct a permafrost assessment utilizing the BLK 360 scanner. In doing so, we will be able to measure the water treatment facilities. These measurements will act as baseline data to compare future measurements to. We look forward to meeting Jeff Luther and assisting with Noatak's monitoring of climate change.
Comments from LEO editors
LEO Member Jeff Luther diligently recorded the erosion effects that Noatak received from heavy rains on June 28th and June 29th, 2021. Attached are photos illustrating the quantitative data of how much land was lost on the riverbank due to this event. The Noatak weather station recorded precipitation for 6/29/21 and 6/30/21. According to the Timeanddate.com Noatak precipitation records graphs below, from June 28th through June 30th Noatak received light rain. The WeatherUnderground graphs attached below also show precipitation data for these days. Chyna Perez-Williams
Excerpted below is also the notice issued by the National Weather Service and archived by Claims Pages found here:
Widespread heavy rainfall is expected to impact the Western Brooks Range, including the Noatak and Kobuk River basins, through mid-week. Rainfall totals of 2 to 3 inches or more are expected in the higher terrain of the Western Brooks Range, with 1 to 2 inches in lower elevations.
Note: this observation has been shared with the State of Alaska Department of Homeland Security and Emergency Management.
Brooks Range