Thunderstorms booming

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SSSdave
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Thunderstorms booming

Post by SSSdave » Sun Jul 19, 2020 2:56 pm

After a dry end of June through July , current forecast for the central High Sierra is now more stormy than forecast previous days. There have been storms the last 2 days and it could get worse across a broader area. I have a permit for Convict Creek but if the these storms continue and raise stream levels, no one may be able to cross the creek at 8990 where the bridge was washed out long ago requiring a ford. Last few hours the storms on radar seem to be sitting in one place growing larger that is always the worst scenario if one is underneath it all for hours. The Convict Canyon below Mildred is obviously one of the worst places to be in such a situation or during earthquakes as the towering canyon has immense amount of steep Paleozoic Era talus and rocks that can readily become debris flows. Will be wise to avoid dangerous lightning exposed areas.

Area Forecast Discussion
National Weather Service Reno NV
310 AM PDT Sun Jul 19 2020

Tuesday, a weak upper low approaches the CA coast with some modest
cooling aloft possible. This could bring a bit more instability
with afternoon heating along with forcing for longer-lived, stronger
thunderstorms starting in eastern California and pushing out into
the western Great Basin by Tuesday evening. There is also a threat
for more widespread coverage of lightning given the potential for
more organized storms. While storms definitely have the potential
to produce heavy rainfall, the increase in lightning coverage will
bring concern for fire starts (fanned by outflow winds) on the
periphery of thunderstorms. -Snyder

.LONG TERM...Wednesday into next weekend...

Most of the medium range guidance stalls the weak incoming trough
over California for mid week and then the trough weakens and
retrogrades to near the CA coast by the weekend. This is a change
from previous model runs with a lot less southwest wind aloft and
thus lesser flow to push moisture out of the area. Thus the risk
of thunderstorms may stay with us through the period. NBM point
probabilities for storms continue to indicate this and thus we
have expanded daily chances for thunderstorms for the eastern
Sierra north to the Sierra Front. Storms may have to be expanded
further if this trend persists in future model data.








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c9h13no3
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Re: Thunderstorms booming

Post by c9h13no3 » Mon Jul 20, 2020 8:49 am

Yeah, got thunderstormed on yesterday, had to get off the summit of Granite Dome in a bit of a hurry before the clouds rolled in. Lots of lightning, a bit of rain, no hail.
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Flamingo
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Re: Thunderstorms booming

Post by Flamingo » Mon Jul 20, 2020 11:15 am

Oh geez, I just returned from a four day trek in Northern Yosemite, and we got heavy lightning, thunder, and rain every afternoon. . . but also plenty of sunshine to dry out :)

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Re: Thunderstorms booming

Post by SSSdave » Sun Jul 26, 2020 9:01 pm

Stormed every afternoon on my 6-day Convict Creek trip 7/20 > 7/21 but was on the periphery each day till being nailed Friday. Current forecast is for the afternoon thunderstorms to end Monday night with dry sunny weather then set to move in for a week plus into August. All these storms are well needed to extend the peak high country greenery and flowers, as late June through last week was very dry. Wildflowers depending on exposure are now at peak in many areas above 9k. Below that is hopelessly dried from the earlier long dry period. Mammoth's Howard Sheckner was bemoaning how this summer started out so dry with no Mexican monsoonal events to this date. Even at 10k some southern exposures may already have gone brown and dried while northerly and forest shadowed zones are fine. The huge lush valley behind Mildred Lake at 9.7k was at peak greenery and flowers. Mosquitoes only out late or mid day sans any breeze in the marshiest places .

At 9.6k Sonora Pass volcanic geology are now lush with wildflowers. Hiked about 2 miles this morning sizing up landscapes. Good enough that this person is likely to spend a day their enroute to my next trip on the East side.

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