Bouldering in castle rock this Friday? (rain?)

Hi,

I was wondering if its reasonable to climb at Castle Rock this Friday or is the sand stone too wet?

It will be too wet.  It rained until noon yesterday.  I watch the fuel moisture data for Ben Lomond (closest NOAA "actuals").  When fuel moisture gets to single digits, it might be dry enough.  If fuel moisture has stayed above 10%, I don't bother going up there.  Here is the link to the data.  https://www.wrh.noaa.gov/mesowest/getobext.php?wfo=mtr&sid=BNDC1&num=72&raw=0

Hey Amir thanks for asking.

Over the years I have seen topos and even this website telling climbers to "wait a day or two after rain" for the rock to dry.  History has shown that there is a lot more nuance to it as castle is affected by the shade of the trees and sometimes the coastal marine layer.  Sometimes the weather forecast does not mention rain however if you were to walk around the park early in the morning you may find things still a tad damp. Whether this dampness is very superficial or not I find I climb my best when Im not facing ethical dilemmas about whether or not I ought to be climbing.  

Thanks Jay for the beta.  A lot of times if you check the weather for say santa cruz or los gatos you dont get a full picture of what went down on skyline.

Look at the forecast

There is a private sensor at CRSP that you can view through WeatherUnderground.  But, it doesn't have history.  I have found that the info for Ben Lomond corresponds surprisingly well to Castle/Indian even though it is not on the crest.  You are correct that there are a lot of variables.  That's why I'm watching the fuel moisture data to try to find something more objective than "x days since rain".

Jay Anderson wrote:

It will be too wet.  It rained until noon yesterday.  I watch the fuel moisture data for Ben Lomond (closest NOAA "actuals").  When fuel moisture gets to single digits, it might be dry enough.  If fuel moisture has stayed above 10%, I don't bother going up there.  Here is the link to the data.  https://www.wrh.noaa.gov/mesowest/getobext.php?wfo=mtr&sid=BNDC1&num=72&raw=0

That is some awesome weather beta, and using fuel moisture as a proxy for "is it dry in the forest" is clever. 

How did you settle on 10% as the threshold of choice? 

JCM wrote:

How did you settle on 10% as the threshold of choice? 

During the fall, when it was dry AF, fuel moisture was 5-7% during the day.  It rained in Oct, fuel moisture jumped into the 20's, and settled back to 7-8% during the day after ~ 3-4 days.  I climbed and it seemed fine (my favorite boulder is relatively dry for the area).  I watched it again after another big set of rains and tried it once it had gone down into single digits.  It was OK where I was climbing.  I noticed that it sometimes touches single digits briefly and then goes back up quickly when relative humidity hits 100%.  Therefore, my current thinking is that it has to hit single digits for an entire afternoon and then come back to single digits the next day.  If that happens, might be good to go.  If it hits single digits and then gets humid and jumps back to 15-20%, I don't drive up to check.  This is my first winter of tracking it and trying to correlate.

Jay Anderson wrote:

During the fall, when it was dry AF, fuel moisture was 5-7% during the day.  It rained in Oct, fuel moisture jumped into the 20's, and settled back to 7-8% during the day after ~ 3-4 days.  I climbed and it seemed fine (my favorite boulder is relatively dry for the area).  I watched it again after another big set of rains and tried it once it had gone down into single digits.  It was OK where I was climbing.  I noticed that it sometimes touches single digits briefly and then goes back up quickly when relative humidity hits 100%.  Therefore, my current thinking is that it has to hit single digits for an entire afternoon and then come back to single digits the next day.  If that happens, might be good to go.  If it hits single digits and then gets humid and jumps back to 15-20%, I don't drive up to check.  This is my first winter of tracking it and trying to correlate.

I wonder if the correlation is different in the spring, when there is less rain and the rock is dry, but the seasonal accumulated moisture allows fuel moisture to stay higher for a while.

Really interesting idea this is.

JCM wrote:

I wonder if the correlation is different in the spring, when there is less rain and the rock is dry, but the seasonal accumulated moisture allows fuel moisture to stay higher for a while.

I poked around online.  I found an article about a weather station being installed that was equipped with a "fuel stick".  Another article explained that a 10-hour fuel stick is four connected Ponderosa Pine dowels made to exact specs.  10-hour fuels are defined to be wood ~ 1/2" in diameter.  The pine dowels are put in the environment and allowed to equilibrate (suck up water).  I assume they could be rained on directly and absorb liquid water too.  I guess they measure the weight and compare to the dry weight, but I haven't found that info yet.

So, this measurement is not measuring real fuels and is not impacted by a root system.  It is measuring the amount of water absorbed and held in the wood.  The atmosphere can dry out quickly, but the wood dries out more slowly.  This seems like a pretty good corollary to what is going on with the rock.

Jay Anderson wrote:

I poked around online.  I found an article about a weather station being installed that was equipped with a "fuel stick".  Another article explained that a 10-hour fuel stick is four connected Ponderosa Pine dowels made to exact specs.  10-hour fuels are defined to be wood ~ 1/2" in diameter.  The pine dowels are put in the environment and allowed to equilibrate (suck up water).  I assume they could be rained on directly and absorb liquid water too.  I guess they measure the weight and compare to the dry weight, but I haven't found that info yet.

So, this measurement is not measuring real fuels and is not impacted by a root system.  It is measuring the amount of water absorbed and held in the wood.  The atmosphere can dry out quickly, but the wood dries out more slowly.  This seems like a pretty good corollary to what is going on with the rock.

Makes sense. I buy it. Clever innovation in using available weather data for climbing purposes. I'll definitely reference this in the future if considering a weekend bouldering trip to Castle Rock.

If you know where the secret stuff is, you are good to go.

Jay Anderson wrote:

There is a private sensor at CRSP that you can view through WeatherUnderground.  But, it doesn't have history. 

It does have weather history. Scroll down on this page and adjust the dates/frequency as necessary:

https://www.wunderground.com/dashboard/pws/KCASARAT125/graph/2022-01-1/2022-01-1/weekly

This station doesn't have fuel moisture, though. Even so, it's worthwhile to compare CRSP and Ben Lomond precipitation history because there are often storms that hit one and miss the other.

Jamie Collins wrote:

It does have weather history. 

Jamie, thanks for straightening me out on that.  Will be useful.  Let me know if you have any observations about climbing conditions vs. fuel moisture in future.

Jay Anderson wrote:

Jamie, thanks for straightening me out on that.  Will be useful.  Let me know if you have any observations about climbing conditions vs. fuel moisture in future.

When I have time, I'll try to download weather history for the two stations and compare them.

Fuel moisture hit 9% yesterday and stayed at 9-10% last night.  It is at 9% this morning and I bet it drops more today.  I am going up today to check it out.

Just a heads up: Castle Rock SP now has its own official climbing closures after rain. There were big no climbing signs plastered around both parking lots. I talked to a ranger, and basically:

• Climbing will typically be “officially closed” for about 2 days after rain
• The website doesn’t get updated very frequently, so the best way to find out about closures is by calling the ranger station
• It seems like closures are based on how wet the rangers think it is, not fuel moisture/whatever data
• The climbing across the street (Sanborn Park) doesn’t have any closures

It‘s been 4 days since rain with pretty low fuel moisture at Ben Lomond but climbing was still closed today. From what I was told, they plan on lifting the closure tomorrow until it rains again on Wednesday. Not sure how/if they plan to enforce this (I saw quite a few boulderers while hiking around today), but definitely something to keep in mind

Michael M wrote:

• It seems like closures are based on how wet the rangers think it is, not fuel moisture/whatever data

This is my experience as well.  And, they aren't too good at keeping track of when it last rained.  But, they're trying and the closures certainly stop some people who would be climbing on wet rock.  BTW, rock was glorious on Sandborn side yesterday...