It appears, the Coast Guard intends to expand Base Seattle by 18 to 53 acres and will be adding at least a couple of new buildings and renovating others over the next ten years. There is a report by The Business Journals here. You can see the Federal Register announcement “Modernization of Coast Guard Base Seattle; Preparation of Programmatic Environmental Impact Statement” here, and you can get a better look at the three alternatives using the virtual displays here. It appears the Base will be getting at least two additional large berths.
In addition to basing the three currently planned Polar Security Cutters, the proposal refers to basing other cutters as well.
This suggests either the “Arctic Security Cutter” (medium icebreaker) and/or the Offshore Patrol Cutter. The OPC seems most likely, and we may see as many as three based in Seattle. If so, it probably means none in Port Angeles or Warrenton, OR. This would seem to follow the pattern of concentrating ships of a class together to facilitate support and maintenance.
Before the current round of recapitalization, beginning with the Bertholf class National Security Cutters, PACIFIC AREA had 13 large patrol cutters, 10 WHECs and three 210 foot WMECs. Three OPCs in Seattle, along with the two planned for Kodiak, two planned for San Pedro, and six NSCs in Alameda and Honolulu would restore that number.
Given the greater emphasis on the Western Pacific and Arctic, along with the fact that FRCs are performing missions that used to require WMECs, particularly in the 7th and 8th Districts, we might expect the number of large patrol cutters in the Pacific to increase, but the total number is now expected to shrink from 44 (or 42 depending on when you counted) to 36. Still 13 ships would only constitute just over one third of the total fleet. I would feel a lot more comfortable if we had three OPCs each in Kodiak, San Pedro, and Seattle, in addition to the six NSCs for a total of 15 large patrol cutters in PACAREA, and three ships of a class at a base makes good sense for the support point of view. .
Thanks to Mike for bringing this to my attention.
Chuck Hill's CG Blog 
That “base” is crammed into the Seattle waterfront and is also in a undesirable area of the city. I am surprised they don’t consider moving the whole thing up to Everett for example. This on the assumption that there is room.
Navy Times version. https://www.navytimes.com/news/your-navy/2021/05/13/coast-guard-looks-to-expand-seattle-base-as-us-ramps-up-arctic-presence/
News Release
U.S. Coast Guard 13th District Pacific Northwest
Contact: 13th District Public Affairs
Office: (206) 220-7237
After Hours: (206) 251-3237
13th District online newsroom
Coast Guard extends comment period for the Draft Programmatic Environmental Impact Statement (PEIS) for proposed Base Seattle expansion
SEATTLE — The Coast Guard has extended the period for public comment on the Draft Programmatic Environmental Impact Statement (PEIS) for the proposed expansion of Coast Guard Base Seattle.
The Public commentary period, which had previously been scheduled to conclude Dec. 2, has been extended and will now close on Dec. 16.
The Draft Programmatic Environmental Impact Statement can be read in its entirety at the following online location: https://www.dcms.uscg.mil/NEPA
The release of the Draft PEIS on Oct. 7 started a public commentary period, during which the Coast Guard will accept public commentary online at https://www.regulations.gov with docket number USCG-2021-0183.
Alternatively, comments may be sent via mail addressed to:
U.S. Coast Guard, Shore Infrastructure Logistics Center, Environmental Management Division, ATTN:
Mr. Dean Amundson, 1301 Clay St., Suite 700N, Oakland, CA 94612-5203.