greno
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Post by greno on Jul 3, 2015 3:52:48 GMT -8
we are leaving in a few weeks and finalizing packing and such. We have never been to Yosemite this late in the year. The NPS Yosemite website has the weather in the valley at 100 to 105 degrees for a high every day for the past week. Totally believable, but most other websites have a 20 degree swing for the high temp in the valley at the same time, i.e. highs of 85 to 90. I guess it could have a lot to do with where the thermometers are placed in the valley.
I am trying to figure out if I need to bring the 20 degree bags or the 40 (may be a little chilly). We are going from Glacier Point to Illiluotte and then around and making our way to Tuolumne, fairly decent elevation. I am just trying to justify in my mind that it may be the mid 30s at night and pack accorindingly because cold wife and kids are worse on Dad. Am I off base with the temps?
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Post by paula53 on Jul 3, 2015 9:40:39 GMT -8
The valley is warmer than Tuolumne Meadows. There is a tremendous elevation gain when driving to the Meadows. Its over 8,000 in elevation. The 40 degree bag may not be warm enough at night. I would bring the 20 degree bag.
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speacock
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I'm here for the food...
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Post by speacock on Jul 3, 2015 11:09:10 GMT -8
At 10,000' and above you can expect 20F temperatures in any month. I spend most of my time sleeping on top of a 20F bag though. I always have at least a 200 Polartek equivalent fleece and for those that need more, a down vest stuffed in bottom of my pack. It takes up about the size of my fist. On top of the fleece, I have a mountain parka or a Prius type waterproof if I am staying below 10,000'. Going over passes, the fleece comes in handy during rest stops so it is at top of pack. Thunderstorms can build quickly and might locally dump 4" of granular hail in an hour...which will usually be gone by bedtime.
One August night on Lyle Creek we had frost near the water and a skim of ice in a cup of water left out. Being new to the area and 'younger', we had over packed and wore everything we had. The other nights (and days) were warm to hot.
I much prefer higher altitudes over the Valley.
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Post by High Sierra Fan on Jul 4, 2015 15:16:20 GMT -8
Somewhere on the park's site is a weather information page that has location specific forecasts. As a rule of thumb you can correct for elevation from a Valley ( 4000 ft at Happy Isles) temperature by using the dry adiabatic cooling rate of approx. 5.5 degrees loss per thousand feet of rise in elevation (the loss varies somewhat depending on humidity) That's because air that doesn't get an energy input (the adiabatic part) responds to the lowering of atmospheric pressure as it goes up by expanding, that movement apart of the air molecules means the temperature is lower. So take the Lows predicted and subtract.... www.nps.gov/yose/planyourvisit/weathermap.htmNational weather service: "Dry Adiabatic Lapse Rate The rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere. The dry adiabatic lapse rate (abbreviated DALR) is 5.5°F per 1000 ft or 9.8°C per km." forecast.weather.gov/glossary.php?word=dry+adiabatic+lapse+rateEta: also a weather forecast for "Yosemite" doesn't necessarily refer to Yosemite Valley and given "Yosemite" is the size of the state of Rhode Island there's a lot to choose from,.., My rule of thumb? I can make warmer sleeping gear inefficient by leaving the bag open etc. but pushing a setup below its rated minimums doesn't work very well at all.
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rebeccad
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Post by rebeccad on Jul 5, 2015 10:57:14 GMT -8
Agree with replies here. If you are going up to Tuolumne, you may want the warmer bags. We just returned from SEKI, backpacking out of Mineral King, so higher than you are going, but random t-storms gave us a wide range of temps. My 32-deg bag was perfect
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Post by High Sierra Fan on Jul 5, 2015 14:15:40 GMT -8
Also which route? Via LYV or Red Peak Pass and Vogelsang Pass as that last is higher than Tuolumne for a good portion.
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greno
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Post by greno on Jul 5, 2015 18:22:14 GMT -8
Going the first night to My. Starr King, next night LYV, HD and then think about it. May go towards Merced then Sunrise, don't know. I taking five days of food, really depends on how my 9 year old handles it. She has done 10 mile dayhikes, but this is new to her. Wife and son will be good, just didn't want to get cold and the weather forecast range for the valley varies too much from site to site. Mailing our food to the post office tomorrow....
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Post by High Sierra Fan on Jul 5, 2015 20:20:55 GMT -8
You've got Half Dome permits? That's great, it's a fun experience. As the trip gets closer (and if you're mailing food I guess it's within the next two weeks or so since theres a limit how long the post office holds packages) the weather forecast will get more sccurate though mountain weather always has some variables with it. Heck last August I got snowed on twice up along the Clark Range.... The Cathedral Range is a favorite of mine and I'm sure you'll all have a wonderful time. Staying hydrated given this year's drought may be the real challenge. Some of the reliable streams are not going to have a long season. Get the latest information for your route from the office as you pick up your permit.
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greno
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Post by greno on Jul 6, 2015 6:37:57 GMT -8
entry date 7/22, close!
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speacock
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I'm here for the food...
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Post by speacock on Jul 6, 2015 10:11:30 GMT -8
You have a 'sweet spot' date. You shouldn't have any snow problems this year and water will more than likely be available in most creeks.
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Post by paula53 on Jul 9, 2015 9:32:01 GMT -8
Yesterday Caltrans closed 120 from a little past Lee Vining to YNP, due to snow. They road is open now. Be prepared for cool temperature any time of the year. Pack accordingly. The rain won't let up until Saturday, here in Northern Nevada.
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Post by High Sierra Fan on Jul 9, 2015 9:39:58 GMT -8
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speacock
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I'm here for the food...
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Post by speacock on Aug 19, 2015 16:23:16 GMT -8
101F in the The Valley yesterday...
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greno
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Post by greno on Aug 22, 2015 7:20:25 GMT -8
We ended up completely changing our trip. The day we picked up our permits in Tuolumne, it was hailing and raining and snowing at about 13k and sticking. We traded in our permit and got a walkup for the original route we wanted from Tuolumne to Happy Isles down the JMT. We had nights in the upper 30s and when we hit the valley 3 days later it was in the 90s. Epic family trip. The first three hours and the last three were tough on all of us, especially my nine year old daughter, but she did great despite of a sometimes less than stellar attitude.
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speacock
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I'm here for the food...
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Post by speacock on Aug 22, 2015 9:16:38 GMT -8
Its great when most things work out. Our kids (when young) would ask if we were there yet from about mile post 1 and the daughter would count the switchbacks. There were 90 something on a trail in Yoho NP in Canada. She almost didn't make it to 11 years old when she started counting back on the return.
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