Exessive Heat Watch Issued 6/16-19

[maverick]

NWS Hanford:

Be careful and take precautions if your heading up.

[Tom_H]

I am wondering how much this will affect the snowpack. Most of the radiation hitting white snow will reflect straight back into space, but as trees and exposed rocks absorb heat that creates a snowball (excuse the pun) effect of more and more melting. This could be the beginning of a huge surge in stream levels.

[Dave_Ayers]

Yup, possible flood stage for the Merced in Yosemite Valley Sunday night.(https://alerts.weather.gov/cap/wwacapge ... 95fb314cf2).

[Wandering Daisy]

Earlier this year I was in Yosemite Valley at flood stage. Honestly, it is a great time to be there. Photography is amazing with all the reflections off the flooded valley. Just at flood stage there is minor flooding, roads still OK to drive in. Right now the issue if coming up 140 is the closure due to rock fall. Forecast is for about 90 degrees in the valley. That heat may make it a bit less wonderful.

Tom, it is not just reflection off snow. When the air temperature is 80 degrees (as predicted) solid snow areas will also start melting. The melt and freezing at higher altitudes will start to create sun-cups. I bet there will be some massive sun-cups this year!

[Wandering Daisy]

PS. I am heading to the cooler Olympic National Park tomorrow and gladly will escape the heat! No backpacking planned- just some day-hikes in the rain forest and beach walking. We will come back on Hwy 1 down the Oregon coast, returning by 4th July weekend, after which I will seriously try to get into the high Sierra.

[Tom_H]

WD, you're right about air temp. Have fun on the car trip. I am sure the little backpack trip with your granddaughter was a true joy.

[wildhiker]

Driving home from the northern Sierra today (Sun, 6/18), my car outside air temperature gauge said it was between 109 and 112 all the way from Auburn to Vacaville, and then it hit 116 on the hill between Vacaville and Fairfield! I admit, this car gauge may not be the most accurate, but I've never seen it that hot before.
-Phil

[Tom_H]

my car outside air temperature gauge...hit 116 on the hill between Vacaville and Fairfield!

If this keeps up, we will not be hiking on snow all summer as we thought. Crossing streams is going to be treacherous for awhile.