|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
A warm and wet storm has pushed into the area this morning. Light to moderate rainfall is occurring below 800-1,000′ with snow above this. The rain snow line could creep up a bit more, to 1200′, before cooling off this afternoon. In the upper elevations, we could see 8-12″ of heavy snow by this evening while almost an inch of rain could fall on snow (or ground) at the lower elevations. Ridgetop winds associated with the precipitation are climbing and forecast to be strong through the day, averaging 40-50mph from the east. What does this all do for our avalanche issues? Well, it all depends on the amount of snow and wind really.
Wind slabs should be the most likely avalanche problem as the higher terrain will see the higher snowfall amounts accompanied by wind. Many of these areas are difficult to access on a day like today, but that said, the possibility of a natural wind slab sending debris into an accessible place in the flats or the trees could catch someone off guard if under steep slopes; for example, under the steep Seattle Ridge gullies. Wind slabs could also be found in the mid-elevation trees if the storm really does put down more than 6″. If headed to these areas, note how much new snow there is and if it’s being blown into fresh slabs.
Even out of the wind, you might see some shallow storm slabs forming as this event is coming in upside down (heavier snow over lighter snow). Both wind or storm slabs could be small and harmless (6″ or less), or in places with more snow/wind, larger and enough to bury a person (1-2′). If braving the rainy and windy roads to head into the hills, it’s a day to really pay attention to the changing weather and signs of instability, such as cracking in the new snow and any signs of recent avalanches.
Cornices: This is a prime cornice building event, sticky warm snow and strong, but not too strong winds. Natural cornice falls are possible, which often turn out to be the main driver for triggering a wind slab in the upper elevations.
Wet snow avalanches: If we really do get rain up to 1,200′, the snow could get slushy and small wet loose avalanches could be triggered in these lower elevations.
Glide cracks continue to open around the region. We are keeping track of where known glide cracks are. So far, these are not in areas commonly traveled by recreating public. Here is a list:
Girdwood Valley: Goat shoulder, Raggedtop lower SE shoulder, the far NE end of Penguin Ridge above Girdwood.
Turnagain Pass: The far northern end and SE aspect of Seattle Ridge, Warmup Bowl (-1 Bowl) NE aspect on the backside of Seattle Ridge.
Summit Lake: Gilpatrick’s S face, Devil’s Creek south side.
Yesterday: Cloudy to broken skies were over the region. Between 1-3″ of snow fell in the early morning before tapper off. The rain/snow line was roughly 500-600′. Ridgetop winds were moderate, averaging 10-20mph during the day, before increasing last night into the 35-40-mph range from the east. Temperatures continue to be warm, in the upper 30’sF at sea level and the mid 20’sF along the ridgetops.
Today: A weather system has moved in this morning from the Gulf. Widespread snow showers above 1,200′ and rain below this is expected through the day. Accumulations are expected to be 6-12″ in the Alpine and .5-1″ of rain at sea level, the higher amounts expected nearest Turnagain Arm. Ridgetop east winds will remain strong, averaging 35-45mph. Temperatures should climb to 40F at sea level and the upper 20’sF along ridgelines.
Tomorrow: Tapering snow showers are expected tomorrow morning before skies begin to clear during the day. Ridgetop winds are forecast to shift westerly and then northerly bringing in cooler air. These should remain somewhat elevated in the 15-25mph range. Temperatures finally look to dip below 30F at sea level and below 20F along ridgetops. Models are hinting at continued dry weather and mostly clear skies for Monday and Tuesday, stay tuned.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||32||0||0.1||129|
|Summit Lake (1400′)||31||0||0||44|
|Alyeska Mid (1700′)||32||3||0.3||116|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||27||SE||14||26|
|05/18/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/30/21||Turnagain||Observation: Sunburst||W Wagner Forecaster|
|04/27/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/26/21||Turnagain||Observation: Magnum||Creighton/ Hoople|
|04/25/21||Turnagain||Observation: Sunburst||Nick D'Alessio|
|04/24/21||Turnagain||Observation: Airplane obs||Johnston-Bloom / DiJulia /Hilliard Forecaster|
|04/24/21||Turnagain||Observation: Corn biscuit||Heather Johnson|
|04/23/21||Turnagain||Avalanche: Lynx Ck Drainage||W Wagner Forecaster|
|04/23/21||Turnagain||Avalanche: Sunburst||Eeva Latosuo|
|04/23/21||Turnagain||Observation: Center Ridge Turnagain pass||Joe Kurtak|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: firstname.lastname@example.org
|Area||Status||Weather & Riding Conditions|
This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area. This advisory does not apply to highways, railroads or operating ski areas.