The remnants of Typhoon Merbok in the northern Pacific Ocean began approaching the Bering Sea on Thursday, September 15, 2022. This storm transitioned into an extra-tropical area of low pressure and strengthened as it traversed the Bering Sea from southwest to northeast. Impacts were first observed with high winds in the Central and Western Aleutians early on Friday, September 16. The storm continued to move northeast and peaked in intensity on Friday with a minimum central pressure of 937 mb at 4:00 AM, which is the lowest pressure ever recorded in the Bering Sea for the month of September (data since 1950). More remarkably, it appears to have been the lowest pressure recorded for any time of year along portions of its track. The storm slowly weakened but remained very powerful as it moved through the Bering Strait on Saturday morning September 17, taking a perfect track to bring significant coastal flooding to the northern Bering Sea coast. The storm continued to move northeast into the Chukchi Sea Saturday afternoon, September 17 and stalled out, gradually dissipating through Tuesday, September 20 over the Chukchi Sea.
The impacts on Friday were mainly over the Bering Sea and the Pribilof Islands in the form of high winds and seas. Buoy 46035, located at 57.016N, 177.703W in the Bering Sea recorded wind gusts to 76 mph and seas of 52 feet Friday morning. By Friday evening, and into the weekend, the low moved towards the western Alaskan coastline, bringing high winds and near record storm surge.
What made this storm unusual was threefold: Storm strength, storm track, and the speed of its movement. As Merbok���s remnants approached the Bering Sea, an eastward transitioning disturbance reinforced the storm���s strength by infusing its energy into Merbok���s remnants, while merging cold, dry air aloft (pulled from continental east Asia), with the tropical surface air below.  This interaction increased the storm���s strength exponentially, while facilitating the storm���s extra-tropical transition. While it is common to get Hurricane-Force winds during the Fall and Winter in these extra-tropical systems, the strength of the storm was historic for the month of September. Additionally, the Bering Sea���s strongest storms typically occur when there is some sea ice present to buffer and protect the coastline from wave action. In September, there is no sea ice in the Bering or Chukchi Seas, leaving the coastline vulnerable to wind driven waves, along with the storm surge.
Also of note were the storm���s track and speed of movement. Merbok tracked from the Southwest Bering Sea in a nearly straight line into the Bering Strait at a speed that induced a ���dynamic fetch.��� This means that the storm moved at the same speed as the waves it was generating, causing winds to continue to build the same areas of high seas, thus resulting in sea heights over 50 feet. The straight line of the track to the Bering Strait meant that these huge seas, once generated, were sustained by the storm until it deposited these seas into the Western Alaska Coastline. This is what caused the record breaking storm surge at some locations.
A myriad of impacts were noted across the West Alaska Coastline. While waters rose in many villages, homes became uninhabitable or lifted off their foundations, and roads were washed out, local community leaders have stressed that many of their villages have sustained a serious loss in their way of life. Of note is the fishing fleet loss, and the many fish camps and smoke houses damaged or lost across many villages. This is more than just a physical loss of possessions and property. These camps have been in families for generations. This is a loss of food security and a place to teach traditional practices and values to the kids.
Flood specific:
High winds and heavy rain from the remnants of Typhoon Merbok caused flooding from heavy rain and wind driven backwater along the Kuskokwim River from Bethel to the Kuskokwim Delta. Heavily impacted were the towns of Napakiak and Oscarville which are located below Bethel, the nearest river gage location. Minor flooding was also likely around the Brown Slough in Bethel. Many small villages in ungaged locations were impacted from this event.

Flood in KUSKOKWIM DELTA, ALASKA
From 16-SEP-22 22:00:00 to 18-SEP-22 00:00:00 (AKST-9)
Location: NAPAKIAK
Flood cause: Heavy Rain / Tropical System
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Coastal surge caused high water on the lower Kuskokwim River with moderate flooding impacts along the lower reaches (Napakiak and Oscarville, AK), and minor flooding impacts in the Bethel, AK area. Mark Leary (Bethel Search and Rescue) reported water flowing up to one foot above the riverbank across (Brown) slough and boat harbor while patrolling the area. Elsewhere on the east side of town the main road was reported submerged.
Twitter post of Bethel and Napakiak flooding: https://twitter.com/MarkSpringer/status/1571228834200166400
https://twitter.com/desertgranite/status/1571191312095019009.

High Wind in WESTERN ALEUTIANS, ALASKA
From 14-SEP-22 15:07:00 to 16-SEP-22 06:05:00 (AKST-9)
Magnitude: 60.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Buoy

Shemya (PASY) observation site went out about 5:00PM, so missed peak of the event as the strongest winds associated with Merbok approached the western Aleutians.  Buoy 46071, located just east of Amchitka on 09 / 15 at 5:40 pm reported 40.8G60.2kts (69.3mph).  Waves reported to 40 feet by buoy camera. Strongest winds were expected between Adak and Shemya, so likely much stronger winds were missed by observational sites in this vicinity, especially with the PASY outage.

High Wind in PRIBILOF ISLANDS, ALASKA
From 15-SEP-22 04:02:00 to 17-SEP-22 00:00:00 (AKST-9)
Magnitude: 64.00 MG
Crop damage: 0.00K
Reported by: ASOS

Buoy 46035 (250 nm West of Saint Paul Island) reported a pressure of 28.08 inches (950mb) Sept 16/1650UTC (850 AM) as the center of Merbok reached it's closest proximity to the Pribilof Islands before continuing northeast.  Wind gusts peaked at around 74 mph at the PASN ASOS, while waves observed to 46 feet by about 7 AM Sept 16th. At 950 AM seas up to 52 feet were observed by the closest buoy.

High Wind in CENTRAL ALEUTIANS, ALASKA
From 15-SEP-22 04:02:00 to 16-SEP-22 06:05:00 (AKST-9)
Magnitude: 70.00 MG
Crop damage: 0.00K
Reported by: ASOS

Adak (ADKA2) recorded a 81mph gust at 3:24 AM Sept. 16, 2022 and first hit 75mph at 5:36 PM Sept. 15, 2022 as Merbok passed to the north of the central Aleutians and pushed strong southwest winds across this portion of the Aleutian Islands.  The last 80 mph wind gust at ADKA2 occurred at 654 AM Sept 16th, and winds decreased afterwards. Several calls were made out from NWS Anchorage to Adak to determine any damage, but these attempts were unsuccessful in reaching any residents.

High Wind in KUSKOKWIM DELTA, ALASKA
From 15-SEP-22 04:02:00 to 17-SEP-22 09:00:00 (AKST-9)
Magnitude: 70.00 MG
Crop damage: 0.00K
Reported by: Mariner

Strong onshore and southwesterly winds moved into the Kuskokwim Delta from the evening of September 16th to the morning of September 17th as Merbok's center moved up towards Saint Lawrence Island and approached the Seward Peninsula.  At 6am AKDT September 17th, Arctic Air (tug boat) reported winds of 45 mph with gusts reaching 80 mph on the Kinak River. Toksook Bay reported the highest measured gust from ground ASOS/AWOS during the event, with a gust to 61kts at about 9 pm on September 16th.  The majority of damage observed across the Kuskokwim Delta was due to coastal flooding/erosion rather than the direct effects from the winds.

Coastal Flood in KUSKOKWIM DELTA, ALASKA
From 15-SEP-22 09:40:00 to 18-SEP-22 09:14:00 (AKST-9)
Crop damage: 0.00K
Reported by: Public

A severe storm surge moved into coastal areas of the Kuskokwim Delta during the height of onshore winds and high waves battering the coast as Merbok's center moved northeast towards the Seward Peninsula on the evening of September 16th.  Some of the most severe impacts as far as coastal flooding across the Kuskokwim Delta were focused in Newtok. Patrick LeMay reported the entire community was inundated with water. Residents were cut off from the airport. They estimated 100 feet of shoreline was lost and that the riverbank eroded between 10 and 20 feet overnight. 12 homes flooded with about 35 people without a home to go back to; no homes floated off their foundation. About 60 to 70 people needed temporary shelter at the Newtok school.  A 5,000 gallon fuel tank washed away; empty fuel tanks and boats floated to the other side of the river, and a handful of boats sank. Serious river erosion also was also reported.