Rain continues to impact Noatak River

Observation by Jeffrey Luther:

Heavy rains have elevated river levels throughout August and September. High water continues to erode the river bank in the community. The photos show a tree that was 22 feet from the edge is know 3 feet. Total erosion has reached 91 ft. by old landfill and new mark shows 112 ft. marker.

Update by Jeffrey Luther 9/7/23: (8:00am) We are going through another high water alert. Here is what we received from the weather station. "Active Weather Alerts SPECIAL WEATHER STATEMENT ISSUED: 2:45 PM SEP. 6, 2023 – NATIONAL WEATHER SERVICE ...High River Levels This Week...High river levels will continue this week on the Kobuk and Noatak Rivers, and rivers on the Seward Peninsula. Heavy rain that fell Tuesday night through Wednesday night is causing the high water. No flooding is expected at this time, but people camping and boating along rivers should be alert for rising water and increased debris in the rivers."

LEO Says:

We were following the forecast from the NWS (August 25) which stated:

"A large portion of the Noatak and Kobuk River Basins can expect 2 to 4 inches of rain through the weekend. The Kobuk and Noatak Rivers and their tributaries could reach bankfull levels by this weekend, with a slight chance of flooding next week. Water will cover gravel bars, increased debris will be in the rivers, and water could rise up to the brush line. People along rivers in this area are encouraged to monitor water levels.

We reached out to one of our top weather advisors," Rick Thoman at ACCAP. Rick provided us with a consult and a graphic from the NWS Alaska-Pacific River Forecast Center showing their estimate of total precipitation August 26 to September 2, with the Noatak valley in the green colors (1.5 inches or less). L. Flora

Comment by Rick Thoman:

Rainfall in the Noatak River valley August 26-27 at the handful of weather stations available above Noatak averaged 1 to 2 inches. From August 27 to September 3 rainfall has generally been in the one half to one inch range. Total summer (June through August) rainfall at the Kelly River weather station upriver from Noatak was nearly 1.5 inches above normal (118 percent of normal).

Comment by Michelle McAuley from NOAA:

First photo: historical plotted point-base precipitation totals from Kobuk & Noatak basins showing Aug 24-28. Howard Pass (the point with 2.23) is in the upper Noatak basin. Based on our precip frequency data estimates, the return interval for that sort of four-day total is close to 5 years. From Aug 17-21 that same station recorded 3.28" rain, which is somewhere between a 10 and 25 year rainfall. From Aug 17-27th, the total was 5.27"; somewhere between 25 and 50 year return interval for 10 days

Second Image: Our gage analysis of the USGS gage on the Kobuk near Kiana, is another perspective. The shaded areas show gage statistics... shaded blue is 90th percentile to daily record, teal is 75th -90th, green is 25th to 75th. The dashed line is the average over the period of record (1976 to present, with a few missing years), and the blue line is observed this year. The gage quickly went from around average to near record in these August rains.

Third Image: Last image is our precipitation analysis for the month of August.