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Avalanche Forecast for 2019-03-19 07:00
- EXPIRED ON March 20, 2019 @ 7:00 amPublished on March 19, 2019 @ 7:00 am
- Issued by Aaron Beverly - Mount Shasta Avalanche Center
Bottom Line
Wet weather with above 6,000 feet snow levels returns tonight. A few inches of snow is expected. Though a rather large wet slab avalanche was observed above the road cut just below Bunny Flat yesterday afternoon, we feel this is an isolated event. Nonetheless, avoid steep slopes below treeline where you see roller balls or recent wet avalanches.
Avalanche Problem 1: Normal Caution
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Character ?
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Aspect/Elevation ?
Normal caution is advised. If traveling into steep terrain, have a plan, but be able to adjust to the conditions you find and the skills your group has. Bring the gear and skills necessary for avalanche rescue.
Wet avalanches, though unlikely, are a concern in isolated areas below treeline. If you see roller balls or pinwheels, it might be time to move to a different aspect.
Forecast Discussion
A wet slab avalanche occurred late in the afternoon yesterday. It was about 150 feet in length, had an 18 inch crown, and occurred above the road cut just below Bunny Flat.
Wet slab avalanches aren't seen much in these parts and are hard to predict. They are often foreshadowed by other wet slab or wet loose avalanches, periods of rapid warming, and channels in the upper layers of the snowpack that allow water to flow to weaker layers beneath. Aside from rapid warming, no other notable signs presented themselves before this occurrence.
We feel this is an isolated event. Similar events would be confined to the road going to Bunny Flat where there are small, steep unsupported slopes created by snow removal operations. Warm weather today may continue conditions capable of producing wet slab avalanches.
Recent Observations
In the last three days, temperatures on Mount Shasta at 7,600 feet have ranged from near 30 to 49 degrees consistently, with lows only briefly dropping below freezing. The snowpack has lost about 7 inches. Easterly and southerly winds have been mostly light.
Although very few signs of wet avalanche instabilities have been seen, a rather large (D3) wet slab avalanche occurred on an unsupported slope above the road cut just below Bunny Flat parking lot. This was about 150 feet long, had a crown of 18 inches, and slid just below a crust layer.
Snow surfaces above 10,000 feet have remained firm. Near treeline, surfaces are softening up after noon. Below treeline, snow has been heavy and wet. No signs of ice fall have been observed.
Weather and Current Conditions
Weather Summary
If you missed out on the fun this weekend, you have one last chance to soak it up before another storm blows in. High pressure will remain in place throughout the day. Clear skies, warm temperatures and light winds will continue until late this evening.
A trough of low pressure to our north is slowly moving towards the forecast area. This will allow scattered clouds to build tonight and tomorrow. The wind will gradually increase as this storm approaches. There is a chance of snow/rain showers Tuesday night, then snow/rain will fall Wednesday. Snow levels will start around 6,500 feet Tuesday then drop to 6,000 feet on Wednesday.
24 Hour Weather Station Data @ 5:00 AM
| Weather Station | Temp (°F) | Wind (mi/hr) | Snow (in) | Comments | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cur | Min | Max | Avg | Avg | Max Gust | Dir | Depth | New | Water Equivalent | Settlement | ||
| Mt. Shasta City (3540 ft) | 30 | 30 | 66 | 46 | 2 | N | ||||||
| Sand Flat (6750 ft) | 29 | 26 | 50 | 35 | 135 | 0 | 0 | 3 | ||||
| Ski Bowl (7600 ft) | 29.5 | 29.5 | 48.5 | 37.5 | 170 | 0 | 0 | 3 | ||||
| Gray Butte (8000 ft) | 35.5 | 35 | 46.5 | 39.5 | 9 | 25 | ESE | |||||
| Castle Lake (5870 ft) | station not responding | |||||||||||
| Mount Eddy (6509 ft) | 30.5 | 30 | 49 | 38 | 3 | 7 | WSW | 130 | 3 | |||
| Ash Creek Bowl (7250 ft) | ||||||||||||
| Ash Creek Ridge (7895 ft) |
Two Day Mountain Weather Forecast
Produced in partnership with the Medford NWS
| For 7000 ft to 9000 ft | |||
|---|---|---|---|
|
Tuesday (4 a.m. to 10 p.m.) |
Tuesday Night (10 p.m. to 4 a.m.) |
Wednesday (4 a.m. to 10 p.m.) |
|
| Weather | Sunny | Clear | Mostly cloudy |
| Temperature (°F) | 45 | 30 | 50 |
| Wind (mi/hr) | East 5-10 | Southeast 5-10 | Southeast 5-10 |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
| For 9000 ft to 11000 ft | |||
| Tuesday | Tuesday Night | Wednesday | |
| Weather | Sunny | Clear | Mostly cloudy |
| Temperature (°F) | 30 | 17 | 31 |
| Wind (mi/hr) | Southeast 10-15 | Southeast 0 | Southeast 15-20 |
| Precipitation SWE / Snowfall (in) | / 0 | / 0 | / 0 |
Season Precipitation for Mount Shasta City
| Period | Measured (in) | Normal (in) | Percent of Normal (%) |
|---|---|---|---|
| From Oct 1, 2023 (the wet season) | 31.74 | 33.38 | 95 |
| Month to Date (since Apr 1, 2024) | 2.21 | 3.88 | 57 |
| Year to Date (since Jan 1, 2024) | 23.33 | 18.17 | 128 |
