2023 snowpack, official numbers in history

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Lenier
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Re: 2023 snowpack, official numbers in history

Post by Lenier »

Wandering Daisy wrote: Fri Apr 14, 2023 9:26 pm With the snow comes runoff. I just looked at today's CDEC 50% probability of peak 1-day snowmelt flows. I am not 100% I am reading this correctly. Correct me if I am wrong.

the numbers below are: 50% probability peak flows date/depth I am not quite sure exactly what "50%" means. At any rate here are a few examples. The most probable case is about 2 weeks earlier for peak flows.

Merced River at Happy Isles 6/4 9.9 feet (note that flood stage is 8.0 feet)
Merced River at Pohono Bridge 6/1 19.6 feet (note that flood stage is 10.0 feet)
Lake Elenore inflow 5/7 5.8 feet
Cherry Creek 5/28 9.2 feet

SF American at Kyburz 6/3 7.9 feet
Rubicon at Hell Hole 5/24 8.4 feet

Kaweah at Lake Kaweah 5/30 13.5 feet
Kings at Pine Flat 5/29 57.3
Kern at Lk Isabella 5/29 24.2

I did not look up all the flood stages. If the melt is at 50/50 probability, it looks like first week in June is the 50/50 probable peak flow. The 9.6 feet over flood stage at Pohono Bridge in Yosemite likely means that the road will be flooded and no access to the valley.

I think the CDEC projections are updated frequently. This is something interesting to keep an eye on. Also, once peak flow is reached it takes time for levels to come down.

https://www.cnrfc.noaa.gov/awipsProducts/RNOHFSSPK.php
Aren't those streamflow values in acre feet, and not in actual water level? I'm not sure how you measure something flowing in acre feet, though. How does this convert to cfs?

"DATA REPRESENTS STREAMFLOW VOLUMES ENDING AT 1200 UTC FOR EACH DAY
STREAMFLOW VOLUMES ARE IN 1000 ACRE-FEET"

EDIT: There is a conversion. You take the numbers on that chart linked in Daisy's post, and divide by 1.983 to get the max cfs at that gage. From there, you can look up a chart to estimate the flood stage. For Pohono in Yosemite, that's just under 12 feet for the 50% probability flow estimate. Please correct me if I'm wrong!
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Teresa Gergen
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Re: 2023 snowpack, official numbers in history

Post by Teresa Gergen »

Driving down into Big Pine today from Westgard Pass/SH-168.
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Teresa Gergen
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Re: 2023 snowpack, official numbers in history

Post by Teresa Gergen »

Some photos from hanging out in the Bishop area today. Bishop skyline and White Mtns from the canal:
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At the road closure just above Aspendell:
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At the South Lake road closure just above Bishop Creek Lodge:
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And below that on the way back down:
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texan
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Re: 2023 snowpack, official numbers in history

Post by texan »

Thanks for sharing, lots of snow to melt. From your pics above 8K-8.5K looks like solid snow on middle fork and south forks of Bishop Creek.

Texan
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