A storm force low from the North Pacific swept through the western and central Aleutians on the evening of February 20 through midday on February 21, bringing high winds to the community of Adak. Storm force winds were aided by a strong (1045 mb) surface high pressure south of the Gulf of Alaska, which led to a strong pressure gradient on the east side of the low as it intensified over the…
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The episode as NWS AFC wrote it up.
A storm force low from the North Pacific swept through the western and central Aleutians on the evening of February 20 through midday on February 21, bringing high winds to the community of Adak. Storm force winds were aided by a strong (1045 mb) surface high pressure south of the Gulf of Alaska, which led to a strong pressure gradient on the east side of the low as it intensified over the western Aleutians late on February 20. The swath of strongest winds pushed through the central Aleutians near Adak during the early morning hours of February 21, before the low quickly exited into the northern Bering Sea.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Anchorage, AK wrote its last area forecast discussion before the first event at Feb 20, 5:13 PM AKST, 7 hours 47 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 513 PM AKST Mon Feb 20 2023 .ANALYSIS AND UPPER LEVELS... In the upper levels the jet stream extends south of the Aleutians and east towards Southeast Alaska. An upper level ridge is dominating the southern mainland with areas of fog and stratus across Cook Inlet, the Knik and Turnagain Arms and across the Copper River valley. Most of the fog has lifted but stratus remains in place. A couple of shortwaves across the AKPen and Southwest Alaska are moving northeast and weakening with brief periods of enhanced winds and scattered showers. A stronger low pressure system is lifting out of the northern Pacific towards the western and central Aleutians with increasing south to southeast winds at Shemya and Adak. Otherwise areas of stratus are located over Southwest Alaska. && .MODEL DISCUSSION... Models are in fairly good agreement with the synoptic scale features, but show some differences in the details of the smaller scale features. The main challenge out west initially will be determining if high winds will occur across the Pribilofs tonight and tomorrow morning. While across Southcentral fog and stratus will pose problems Tuesday morning as well as a shortwave moving across the area Tuesday evening through Wednesday morning with chances of light snow. Most models are showing brief periods of light snow but differ on the timing and coverage, so this lends to lower forecast confidence. Otherwise, two strong low pressure systems will move across the Bering Tuesday and Wednesday which will pose Ptype challenges for Southwest Alaska. && .AVIATION... PANC...VFR conditions with light winds are expected through this evening with a chance of fog and stratus moving off of the water, which could bring periods of IFR conditions after midnight into the morning hours on Tuesday. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)... A quiet weather pattern will persist across Southcentral for Tuesday and the first half of Wednesday. Clouds will increase Wednesday afternoon as the upper level ridge shifts eastward and the subsidence associated with this upper level ridge ceases. Forecast confidence decreases Wednesday evening and remains low on Thursday with respect to forecast specifics. The general trend is snow will move across the region Wednesday afternoon and taper off Thursday morning and afternoon. Confidence remains low with respect to exact forecast snowfall amounts, though there is confidence that the highest accumulations are expected across the Hatcher Pass area. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Tonight through Thursday)... A ridge of high pressure over the Southwest mainland will slowly shift eastward midweek. Meanwhile, low stratus and fog trapped underneath the ridge will likely stay overnight. For the rest of the workweek, an active weather pattern is getting underway as a series of storm systems impacts western Alaska. The first system is associated with a North Pacific low approaching from the Bering into the Chukchi Sea early Tuesday. Daytime temperatures will increase into the mid to high 30s as gusty southerly winds move into the region. Precipitation with this system will spread over the Kuskokwim Delta and Bristol Bay between Tuesday and Wednesday. The region will initially start out as snow before warmer air results in snow mixing with or changing to rain. However, there is still some uncertainty about the initial colder air in place, leaving a small chance of freezing rain early in the morning on Wednesday. After this system pushes northward, the next warmer system arrives shortly afterwards on Wednesday. Daytime temperatures will be in the mid 30s to low 40s along with gusty, southwest winds. Precipitation type is likely to be be rain as the atmospheric column of air warms above the surface for the entire forecast area. Rain will be more widespread for the low-lying regions through Thursday evening. As the system exits the region, cold, dry conditions returns as a weak ridge moves overhead later this week. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 to 3: Tonight through Thursday)... The main weather feature is associated with a strong North Pacific low approaching the western Aleutians. The leading frontal boundary will overspread the region, bringing elevated seas, heavy precipitation, and widespread gale force winds, with localized areas of storm force winds. The strongest core of winds are expected Monday night through early Tuesday morning for the central Aleutians as the wind direction shifts to the west- southwest. A High Wind Warning remains in effect from midnight tonight to 9am Tuesday. Precipitation type will predominately be rain as the atmospheric column of air warms above the surface. As the low lifts northward on Tuesday, the Pribilofs can see increasing southerly gales to storm force winds and precipitation as well. There is moderate confidence that the region could reach hurricane force gusts as a cold, unstable air wraps around the low. A High Wind Warning remains in effect from 3am to 6pm AKST Tuesday. Conditions are expected to improve briefly Tuesday followed by a second system arriving in the evening. This system will bring another round of rain and southerly gale force winds between Tuesday night and Thursday. Conditions will slowly improve for the rest of the week as a weak ridge of high pressure moves overhead. && .LONG TERM FORECAST (Days 4 through 7: Friday through Monday)... Model disagreement is becoming more noticeable by the end of the week towards Friday, but the overall trend towards much colder, drier conditions developing across most of the southern Mainland going into the weekend still looks probable. The GFS in particular appears to be struggling with the interaction between a shortwave trough diving southeast across the Alaska Peninsula and a separate low set to be entering the Gulf on Friday and Saturday. The 12z GFS is depicting partial trough phasing between these upper features, resulting in a much deeper low compared to other solutions developing over the Gulf through Saturday. Aside from the apparent outlier scenario in the GFS across eastern parts of the outlook area, models are in good agreement for a much colder, drier period to take shape across most of Southcentral and Southwest this coming weekend, as an Arctic air mass filters in from the northwest under deep synoptic troughing developing aloft. Out in the west, another potent gale to storm force low will traverse the Bering from west to east as it rides around a flat longwave ridge. Most solutions show the low weaken rapidly as it moves downstream from the strengthening ridge and as it crosses the southern Alaska Peninsula late on Saturday, keeping broader impacts from this system limited more to the Aleutian Chain and Pribilofs. Looking out towards the start of next week, solutions are continuing to key in on another much stronger system entering the western Bering by late Sunday into Monday. This pattern is beginning to look almost like a 'reset' back to what we will see unfold over the next few days, with a strong ridge over the Bering again shifting towards Southwest while another deep low pressure moves into the Bering in its place. While the exact details for this next system well out in time are unsurprisingly not well- defined, it's becoming more likely for another very deep low to cross the northern and western Bering between Sunday and Monday. A strong trailing front could approach Southwest with increasing potential for strong winds and heavy precipitation by Monday. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...High Wind Warning: 187, 195. MARINE...Storm Warning: 170, 173-177, 179, 412-414. Gale Warning: 165, 172, 178, 180, 181, 185, 351-352, 411. FIRE WEATHER...NONE. && SYNOPSIS AND MODEL DISCUSSION...RC SOUTHCENTRAL ALASKA...ED SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MF LONG TERM...AS
1 high wind. Local standard time, as filed.
A National Ocean Service observing station in Adak recorded several wind gusts in excess of 65 knots (75 mph) during the morning hours of February 21. There was also an isolated wind gust to 69 knots (79 mph) during the previous afternoon, though winds during this secondary peak otherwise remained below the high wind threshold.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Alaska in 2023Every state in 2023This day in weather historyWarnings in Alaska, February 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1102222.