Friday, April 8, 2022

Silvertip - 12.13.2015

Note: updated below the original post to include a version of the Silvertip Traverse in March 2022.
After a great window of high pressure, last week brought two and a half feet of new snow to the top of Turnagain Pass.

Waking up in the morning dusk, we followed the old mining road up the creek. 

But, the high pressure had a downside, it left a weak surface for the new storm snow to bond to. As it slowly got lighter, we were treated to a view of Twin Peaks:

By the time we reached the upper basin, there was a foot of new snow sitting on a settled base. 

Wanting to take advantage of the new snow, but to avoid the danger associated with a thick slab we headed to the southern end of Turnagain Pass.
Avoiding potential avy danger, we followed the north ridge towards the summit. On the skyline is TT43, one of my favorites.

Anchorage Ski Outlook - How to Forecast

1 Minute
5 Minutes
Use Meteoblue Multimodel to see differences in magnitude and timing between models for sun, precip, and temp. For wind, different models have different resolution - think number of pixels in a picture - resolution affects wind forecast, so just look for relative windiness over a week. Confidence in your forecast will be higher if the different models agree. Check back on Meteoblue every day to see if the models are consistently forecasting the same weather - if the forecast is different each time you check then the confidence in your forecast will decrease.
Use the Southcentral Alaska Mountain Forecast and the NWS Point Forecast for the Rain/Snow line - they are imperfect products, but so is rain line forecasting.
 
15 Minutes
  • Short Term Forecast Southcentral AK - most useful, provides specific weather.
  • Model Discussion - usually useful, informs confidence in your forecast.
  • Long Term Forecast - sometimes useful, provides possible trends.
  • Analysis and Upper Levels, Marine Gulf of AK - details and learning opportunities.
  • New Snow -  Use to figure out what area is favored. Hatcher Pass, Anchorage Front Range, and Turnagain Arm storms are better captured by high resolution models (NAM & ECMWF). Note, Windy uses a 10X conversion from precip to snow, with cold storms, the Snow/Water ratio will be 15X or higher.
  • Winds @ 3000 ft - Surface winds. These require high res, so NAM/HRRR are best, then ICON and ECMWF, with GFS the worst.
  • Winds @ 250 hPa - Jet stream elevation - the weather conveyor belt. When it overruns us from the SE it brings precip to western Prince William Sound mountains and the Tordillos/Neacolas. As it rotates and overruns to the SW it favors precip for Hatcher, Anchorage Front Range, Thompson Pass, and the Central Alaska Range. Look to see if the jet stream is coming from as far south as Hawaii for warm Pineapple Express storms. From the N it brings cold and often outflow winds.
Long Term - Should I do a Fly-In Trip???
  • Windy's 10 Day ECMWF and GFS Forecasts - Do the two models agree? Is the forecast changing each time you pull it up? For higher confidence in your forecast look for agreement between the two models and between runs of each model.
  • NWS Forecast Discussion (referenced above) - This product is produced twice daily. Read the long term forecast. Does each new forecast discussion say generally the same thing or it changing? Look for the terms "confidence", "agreement" and "differences" throughout the forecast discussion - this will let you how much the Weather Service is trusting the models.
  • Meteoblue GFS Ensemble and ECMWF Meteogram - Farther into the future the model spread will generally grow. The bigger spreads there are for temp, precip, and wind, the less confidence you have in your forecast and the more prepared you need to be to shovel and hunker down!
And as always - beware of falling snow!!!

Archived 2022 Anchorage Ski Outlooks

3.23.2022

Thurs – Fri: stormy, warm, windy (high confidence).
HEAVY snow (warm, windy everywhere) favoring the mountains closest to the western PWS (Whittier/Portage) then drying out as you move away from there with Hatcher just getting wind and Thompson getting light snow. Rain near the Turnagain Pass road level. Winds everywhere.

Weekendshowery, partly cloudy, warm (high confidence).
Showers for Turny/Gird and especially Whittier/Portage. Partly sunny elsewhere, with the most sun the farther away you are from the western PWS. Rain showers during the day near sea level along Turnagain Arm. Ridgetop winds. Sun affect on south slopes touched by the sun.

Early Next Week: coastal snow, dry inland, warm (low confidence).
Moderate snow for Turny/Gird and especially Whittier/Portage Mon into Tues; rain at sea level. Low confidence in drying for the western PWS mountains on Wed. Light snow for Thompson Pass; showery for the Anchorage FRange; dry at Hatcher. Moderate winds. Sun affect on south slopes touched by the sun.

Dirty Details
Wowie!!! This is a big Turnagain/Girdwood/Whittier storm that will leave Hatcher high and dry. That is courtesy of strong winds blowing from the southeast that heavily favor the western Prince William Sound:

Friday, April 1, 2022

Pioneer Peak - 3.30.2018

Note: updated below the original post to include an evening lap on the north face in March 2022.
Over the last two days Brian and Sam had both skied Pioneer, and it was about to get a refresh - it was time to go get it. Only two small problems: I didn't own ice tools, and Alex had a project due at work. Easily remedied. That night I went to REI, and Alex called in sick with a bad case of powder fever.

Pioneer's giant north face towering over Palmer.

The next morning found us driving back and forth on the Old Glenn looking for the north face trail-head. After a few laps we'd located the appropriate thicket and were skinning into the alders. Within 500 vertical feet we'd reached the avy debris and were soon climbing mellow ice.


I'd never used ice tools before, and was pleased to see how much better they performed than my finger nails and running shoes. Kind of like being a cyborg.

Tuesday, March 15, 2022

Lynx Creek - February & March 2022

In the middle of February 2022, a wet storm riding strong south winds pounded the mountains above Turnagain Arm, overloading the snowpack, and producing a dramatic avalanche cycle. We needed a snowpack that received less of a load, so headed south for the Johnson Pass trailhead. 

As we drove along the Arm we passed the terrifying remains of splintered trees, new avy paths, and concrete debris that had covered the road and railroad. My reptile brain screamed to go home and ride the Stairmaster, but we knew what we were seeing told us nothing about the stability, or lack thereof, in Lynx Creek.

Rolling into the parking lot we could see a couple big crowns in the headwaters of Lynx. As we skinned out of the parking lot and thru the two-stroke exhaust hanging in the valley I figured our odds of a shutdown on our objective of Captain's Chair were around 75%. Soon we were skipping across the flowing waters of Bench Creek; I love a good creek crossing and figured this was a good omen for the day.


As we entered the Lynx drainage we left the creek and started to gain altitude towards Captains Chair. But, not before first stopping to inspect the little cabin overseeing the valley. Tom and Erin took notes for their future cabin - especially on the importance of having a good supply of food for the local porcupine population. 


Entering the hanging valley below our objective we could see that the chute had already slid. Sweet. We weren't in for a complete shutdown.