An upper-level trough and embedded low overspread much of mainland Alaska, while a series of shortwaves rotated through the trough. At the surface, an attendant low and its front, extended from near Kodiak Island and out along the Southcentral coast.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS AFC wrote it up.
An upper-level trough and embedded low overspread much of mainland Alaska, while a series of shortwaves rotated through the trough. At the surface, an attendant low and its front, extended from near Kodiak Island and out along the Southcentral coast. As a result, widespread (heavy) snow showers persisted along the Southcentral coastal regions and gusty winds blanketed the Gulf of Alaska, Prince William Sound, and areas north towards the Copper River Basin.
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 Mar 16, 3:53 PM AKST, 17 minutes earlier.
Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 453 PM AKDT Thu Mar 16 2023 .ANALYSIS AND UPPER LEVELS... The high amplitude ridge/trough pattern persists across the state this afternoon. Northerly flow between the two continues across the Bering with gusty winds and snow showers from the eastern Aleutians to the Alaska Peninsula. For Southwest Alaska, conditions are generally clear and dry with scattered mid to high level clouds. To the east, the upper-level trough axis extends from Kaktovik to the north south and west over the north Pacific. Multiple waves continue to rotate around the upper-level low anchoring the trough. The first of these waves is moving inland over Southcentral with an increase in mid and high level cloud cover. The second of these waves is associated with an occluded surface east of Kodiak City. A surface trough extending from this feature is moving from the northern Gulf to the Southcentral coast, with yet another band of snow showers from Homer and Seward across Prince William Sound to Cordova. Satellite imagery is also showing the development of a baroclinic leaf, the precursor to the next surface low, as yet another shortwave rounds the base of the trough and begins to move north toward the Gulf of Alaska. It is this system that will produce widespread precipitation and gusty winds across the Gulf and southern half of Southcentral Alaska beginning Friday. && .MODEL DISCUSSION... Models remain in overall agreement thorough Saturday morning, having now homed in on the evolution and track of the compact storm-force low as moves from the eastern Gulf to the Barren Islands. Beyond that time, however, model divergence grows, especially with the potential development of a new storm-force surface low. There was quite a bit of uncertainty regarding this feature within the 00z and 06z guidance. Most recent runs (12z and 18z), however, are starting to key in on a solution of surface low development over the eastern Gulf for late Saturday morning, moving east-northeast toward the Barren Islands for Sunday morning. The 12z GFS is the strongest with this feature, taking a slightly more southerly track. The 12z and 18z NAM have a weaker feature that tracks through the northern Gulf and along the Southcentral coast. The 12z GEM and EC depict solutions much more similar to the GFS. && .AVIATION... PANC...VFR conditions and light winds will persist through early Friday morning. Light snow is expected to develop by early morning Friday, potentially lingering through late Friday morning. MVFR conditions are expected during this time with the potential for IFR conditions if a period of more moderate snow develops. Northerly winds will also increase beginning early morning Friday with gusts approaching 25 kt by mid-morning. && .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Friday and Saturday)... A near-stationary low that had been persisting off the east coast of Kodiak Island is finally beginning to weaken this evening. Through the rest of tonight low pressure will continue to weaken and ultimately dissipate over interior Bristol Bay. The big forecast challenge over the next 24 hours entails the next North Pacific low, which will cross over Kodiak Island by midday tomorrow. A winter weather advisory is in effect for Kodiak Island with snow and blowing snow expected through Friday morning. Strong southerly flow east of the N Pacific low will bring an influx of moisture along with snow into coastal regions of Southcentral. Warming temperatures through Friday afternoon will see some areas transition from snow to a rain/snow mix, or even all rain. Coastal areas of Prince William Sound, including Cordova, Whittier, and Portage will be the most prone to the changeover. Likewise, Seward is also expected to see a warm-up through midday on Friday. Further inland, moderate to heavy snow is forecast from Valdez up into Thompson Pass. Gusty winds are expected to reduce visibility due to blowing snow, and a winter weather advisory in effect for the region. Moderate to heavy snow is also forecast across the Eastern Kenai Peninsula, especially from Moose Pass up into Turnagain Pass. Areas of light snow remain possible across the Anchorage Bowl up into the Mat-Valley on Friday. Lower elevation areas may see an inch or less of accumulation. Higher elevations could see around 2 inches of snow. With the southern position of the Gulf low over Kodiak, the pressure gradient will reintroduce enhanced Mat- Valley winds on Friday. Wind gusts ranging from 25 to 35 mph are expected during the late morning and early afternoon hours. Snow and blowing snow may reduce visibility at times. A second Gulf low is forecast to push across Kodiak Island on Saturday. This second low is looking stronger with a broader region of storm force winds possible across the Gulf, and the potential for hurricane force gusts. A slightly more southward track may spare the Kenai Peninsula and Prince William Sound from the strongest winds. Another round of precipitation, including rain and snow, appears likely over the second half of the day. && .SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3: Tonight through Sunday)... A trough situated over Mainland Alaska will continue to bring begin conditions across Southwest. As the aforementioned trough continues to sit in place, warmer air wrapping around will eventually move into the region later this weekend and bring back chances of precipitation to the Bristol Bay area by at least Friday evening through Saturday morning. Otherwise, expect clear conditions tonight and then again by Saturday afternoon, along with a gradual warming trend through the forecast period. && .SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 3: Tonight through Sunday)... A trough anchored over Mainland Alaska continues to bring colder air down from the north across the Bering. This is creating convective showers with gusty winds that have been impacting the Alaska Peninsula, eastern Aleutians, and the central Bering/eastern Bering the past couple days. By Saturday, chances for precipitation begin to increase for the western Bering as shortwaves drop from the north and the ridge currently in place shifts to the west. Meanwhile, the eastern Bering will continue to experience benign conditions with northerly flow. The next big weather maker will track into the western Bering by Sunday and will bring back precipitation, gusty winds, and southerly flow to the Bering as it slowly tracks east through next week. Be sure to check back with the forecast as this system develops! &&.LONG TERM FORECAST (Days 4 through 7: Monday through Thursday) Looking into the extended forecast, both deterministic guidance and their respective ensembles concur on the continuation of an active weather pattern through Thursday for both domains. A pair of negatively tilted shortwave troughs lift northward from the Gulf of Alaska and into Southcentral Alaska through Wednesday morning. The best chance of precipitation associated with these shortwaves will be for coastal Southcentral due to having the best upslope enhancement. A more significant trough digs southward from Siberia, through the Bering Sea, across the Alaska Peninsula, and into the Gulf Wednesday as it becomes negatively tilted in nature. However, both deterministic guidance and ensemble guidance are not in agreement with the ultimate evolution and behavior of this trough. The 12z Canadian deterministic guidance is the furthest north with the closed upper-level low in the northern Gulf, while the GFS is way further south with the upper low in the North Pacific and south of Kodiak Island. The 12z ECMWF is in between the GFS and Canadian. Where this upper trough decides to negatively tilt and where the upper low closes off will ultimately determine the track and strength of the associated surface low for Wednesday into Thursday and its effects for Southcentral. Out west, Southwest Alaska will initially be unsettled as a deep Bering Sea low sends its front into the coast and inland Monday afternoon bringing a chance of moderate to perhaps heavy precipitation, especially for coastal sections of Southwest. An additional front on Wednesday and Thursday may impact Southwest, but as alluded to previously, there is a lot of uncertainty with this system at both the lower levels and upper levels. The Bering Sea and Aleutian Chain both look to remain active as well with continued lower heights and overall trough conditions persisting through Wednesday. The front that affects Southwest on Monday afternoon, first sweeps the eastern Aleutian Chain Monday morning with moderate precipitation and gusty winds. After that, conditions remain unsettled with additional shortwaves digging southeastward from Kamchatka, through the Bering, and across the Chain through Wednesday. Zonal flow, from west to east, tries to establish itself through the Bering on Thursday, but there is a lot of uncertainty there as guidance hints at a North Pacific low trying to lift northward around the western Aleutian Chain around that time as well. && .AFC WATCHES/WARNINGS/ADVISORIES... PUBLIC...Winter Weather Advisory 131 171. MARINE...Storm Warning: Northern Gulf. Gale Warning: Barren Islands, Kamishak Bay, Shelikof Strait, Prince William Sound, Lower Cook Inlet. Heavy Freezing Spray Warning:Alaska Peninsula, Bristol Bay, Pribilof Islands, Kuskokwim Delta. FIRE WEATHER...NONE. && SYNOPSIS AND MODEL DISCUSSION...TM SOUTHCENTRAL ALASKA...BL SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...NS LONG TERM...DN
SPECIAL WEATHER STATEMENT National Weather Service ANCHORAGE AK 406 PM AKDT Thu Mar 16 2023 AKZ125-171215- Western Prince William Sound- Including the cities of Whittier, Seward, Girdwood, and Moose Pass 406 PM AKDT Thu Mar 16 2023 ...SNOW AND POTENTIAL BLOWING SNOW FRIDAY INTO FRIDAY NIGHT... An unsettled weather pattern continues across Western Prince William Sound and the Eastern Kenai Peninsula. The next Gulf low will bring renewed snow showers and gusty northerly winds, beginning early Friday morning and lingering into Friday night. Snow is expected to become heavy at times, especially along the Seward Highway, from Moose Pass to Summit Lake to Turnagain Pass. Elsewhere, warming temperatures by midday may change snow over to a rain/snow mix or to all rain for Portage, Whittier, and Seward. Travel may become difficult and motorists are urged to slow down and use caution.
3 winter weather. Local standard time, as filed.
Kyle Sobek (Thompson Pass DOT) reported 2 to 2 1/2 feet storm total snow at Thompson Pass and 10 in Tonsina.
Kodiak City leadership reported storm total snow amounts of 12-14 inches (more than what was reported at the airport). They also mentioned that the Coast Guard Base had shut down for the day.
The Kodiak Airport ASOS noted visibilities of a quarter mile in moderate snow showers and freezing fog at the peak of the event. Westerly winds were noted at 26 kts with gusts to 40 kts at 2:12PM.
DOT reported 10 inches new snow in Tonsina. Meanwhile, the 511 webpage noted very difficult road conditions from MM 42 to 82 along the Richardson Hwy due to heavy snow, wind, blowing snow, drifting snow, icy patches, and reduced visibility.
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, March 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: 1105211, 1105212, 1105213.