High Sierra Topix

NWS:

A very impressive cold fall-like trough will dig south in the EPAC by Sunday into NORCAL from the Gulf of Alaska. The system is moisture starved and will bring light precipitation to the higher elevations of the Sierra with a few showers possible mainly north of Tulare County Monday night and Tuesday morning. Snow levels will start out around 9500 feet and lower to around 8500 feet before ending Tuesday morning. A light dusting to up to around 2
inches is possible above 9000 feet in Yosemite NP.

Be prepare, if your heading out this weekend into next week!

Plus crazy wind chill. Here's the forecast for Lyell Canyon.

Monday A 20 percent chance of snow after 11am. Mostly sunny, with a high near 45. Very windy, with a southwest wind 25 to 35 mph increasing to 35 to 45 mph in the afternoon.
Monday Night A 50 percent chance of snow. Mostly cloudy, with a low around 27. Windy, with a southwest wind 30 to 40 mph decreasing to 20 to 30 mph after midnight.

Hi, fairly new to this forum. I'm just wondering how accurate the weather.gov localized reports are. I'm currently planning a loop through Ansel Adams Wilderness in the Thousand Island Lakes area. Current reports say overnight lows around 25 with potential snow next week. Is there any chance temperatures would go any lower than that?

Possibly. You can never tell. I would plan for the temps to get about 5 degrees below that. You have to plan for that to stay safe in the backcountry in the autumn months.

Yeah, after the 2nd week of September, you really need to be ready for it to get down in the teens at higher elevations. Summer is short in the mountains.

I find the NWS forecasts quite good, short term. No forecast is more than about 50/50 after five days. You have to put the cursor on the exact area you are considering. Just zoom in and then click. Because the forecast area is a square block, you sometimes have to move the block a bit to match the elevation of a specific location.

Many times the forecast is generally correct, but the timing is off. A storm may slow down and take a day or two more to move into your location, of it may come in sooner.

In general they will be conservative for 3-4 days out- for example will call it 30% chance of rain/snow, but sooner to the event, it may go either way- the storm may peter out or it may increase to 60% or more chance of rain/snow. You need to be prepared for rain/snow, even if it says only 20%- statistics apply to the larger block, you may end up in the 20% if the block that WILL get rain/snow.

Micro-climate of where you set up your tent can impact the temperature +/- 10 degrees F. The wind generally dies down at night, so cold air settles in low points. If you camp out in the open, it is colder than under tree cover. Too close to water and you get a lot of dew and condensation.

When they say 40-60 mph winds, that is SERIOUS! Not conditions for a novice. Even when prepared and experienced, high winds can be very challenging.

Appreciate all the advice and comments. It looks like there is a cold front moving in this week and there will be chance of rain and snow, but winds will be between 5-15mph.

I'll be bringing my 3 season sleeping bag, my 40 degree quilt as an additional layer, and an additional GG thinlight. I'll also try to camp in some tree cover to help minimize overall exposure to the elements.

Just came out this morning on the Lamarck trail. Search and Rescue was on site, wind gusting to 60 MPH and light precip in the form of sleet. Very nasty last night at upper Lamarck lake. The info I heard at the the trailhead was a rescue attempt on on of the peaks.

I have been tracking the cold front moving in around Bishop/Mammoth area for this weekend (9/27). I may do a hike, just a couple nights, weekend trip. When I first started tracking there was a pretty good chance of snow. Today however, mostly sunny over the weekend, very little chance of snow, but cold temps. Anyone with more accurate info, and what might be a good 2-3 nighter at (semi) lower elevation (10'000' or lower maybe)? We were originally going to do Bishop Pass to LaConte canyon thru Dusy, but time got the best of us so we'll probably do it next year. One thought was the Ediza and Minaret Lake loop from Agnew Meadow. Any other suggestions? We will only hike 6-8 miles/day, we like to take our time. As always, thanks for any input!

Mike West

NWS just changed their forecast- added winter storm watch for the northern Sierra. If you go out, stay south!