High Sierra Topix

I recently got permits out of Red Cone (7/13) to head north to Yosemite. I know the currently snow pack is pretty low compared to averages and significantly lower than last year.

At what point in time during the snow season would you feel comfortable forecasting the snow conditions for the 2024 summer hiking season? Additionally, when does Yarts typical publish their summer schedule for Mammoth Lakes HWY 120E/395 route? I know this is tied into the snow conditions and clearance of Tioga Rd.

Thanks in advance for any insight.

The peak of snow depth is normally around the third or fourth week of March. There can still be more snow after that, but there is a lot more melting. As a result, I used to make most summer plans around April 1.

I have been watching snow pack info for many years as part of planning spring ski trips, and the takeaway is that I would pay no attention until at least April. The state uses the snowpack as of April first as its measure of the snowpack based water supply, because historically that is the peak amount. But variation from year to year not only in total snowpack but also in when it falls, is substantial. There is plenty of data on the state water department website, some of it realtime, so you can see not only the current state of the snowpack but also the ongoing trend and historical data to compare to.
The short answer is, pay no attention before April, and keep looking at it until June.
And historically, on average, in Mid July you will have few issues with snow but the skeeters may be fierce.
I have no idea regarding the Yarts info.
https://cdec.water.ca.gov/snowapp/swcchart.action
That page gives you the quick overview on current snowpack. You would be kinda on the cusp of central and south.

Yea, at least end of April. There are Big Snow years that were of no consequence by mid summer, because the last big spring snow storm - generally around Easter - failed to produce. On the other hand, I recall several years when snow lingered late into the summer season, when the last significant April snow storm dumped a load, regardless the rest of the snow season was lack luster.

Ed

Ha! I was going to answer the first of May, for the reasons stated above. Of course, if the year is truly a drought year, then May 1 might be a bit late...we've done at least one trip in April, when there was no snow at 8,500 feet. It was colder than h3ll, thought...grin.

balzaccom wrote: ↑Sun Jan 21, 2024 7:49 am Ha! I was going to answer the first of May, for the reasons stated above. Of course, if the year is truly a drought year, then May 1 might be a bit late...we've done at least one trip in April, when there was no snow at 8,500 feet. It was colder than h3ll, thought...grin.

I always plan after opening day of trout season or about May 1st but as you said(Balzaccom), this is a drought year so that may be a bit late. One good thing about a drought year is you can fish the rivers and streams early. Last year was a bust because of all the run-off. The West Walker wasn't fishable until late August in most parts.

Texan

To give a guesstimate, the current snow pack is a bit below average. I would expecting hiking to open at a typical cadence, not early or late, with most options being "in" come June.

For example, at the Central Sierra Snow Lab at 6000', they've gotten 76% of average for total water falling from the sky, but only 60% of a typical snowpack due to a lot of it falling as rain. In the higher elevations of the Sierra, rain is obviously less of an issue. Areas in the southern part of the range (the Whitney Zone for example) are trending towards being significantly drier, but the El Nino pattern is still going (favors southern precip), and it only takes a storm or two to get them on track.

But the bottom line is, we're below normal, but not so much that I'd be banking on an early entry yet. But keep your eye on May permits in the southern & lower elevations of the Sierra.

It is still too early to project the current snowpack to the "final" one, although I think it highly unlikely we'll have a super heavy winter like 2023. We've had some winters that started out dry but ended up above average owing to very late storms (1986 is an example). In contrast, we've had other winters where we started out on a pace ahead of average but ended up quite dry because little additional snow fell after a fast start to the season. Accordingly, I always wait until the beginning of April to check the snow pack measured late in March. Note also that the snowpack usually varies a lot from north to south, so it pays to check out the snowpack for select snowcourses near the area of interest instead of statewide or Sierrawide averages.

It is somewhat true that predicting snow conditions in a future June while presently in January comes with some wide error bars, if things are trending one way or another strongly enough, you can start to rule out certain possibilities.

The three snowiest months in the Sierra are December, January, and February (really more like December 15th thru March 15th). And usually by February with 2/3rds of the vote already in, the range of possibilities get narrower.

If I was thinking about putting down $20 getting a desirable permit for Memorial Day (that doesn't cross any unbridged creeks or any big passes), I think it's probably worth that bet. But there's another atmospheric river in the forecast, stay tuned.

The precipitation forecast is less confident than the temperature forecast
during the week-2 period as warm, moist Pacific air once again engulfs the
CONUS. The strongest precipitation chances are across the West Coast where an
atmospheric river event is forecast bringing greater than 70% chances for
above-normal precipitation to parts of Northern California.
https://www.cpc.ncep.noaa.gov/

Looking at the CDC Snow Water Content reports for the three regions and the state as a whole, 6 out of the last 23 years have had similar or less snow. Not one of those years reached the average for water content at the snow sensors in any of the regions, including the southern Sierra (it looks like the highest was about 80% of the April 1 average). Of course, all of those snow sensors aren't necessarily where we want to go. Also, this is only looking at the past 23 years of snow data. Right now, I'm feeling pretty good about August, including mossie levels, but I'm not ready to start planning on any July trips into the high Sierra. If we're still trending well below average at the end of January, then I'll feel better about a mid-July start for the high Sierra.