The Subway--High Flash Flood Danger...

[effjammer]

I've got a permit to hike the Subway top down tomorrow, August 22. The NWS just issued a "High" warning for flash floods in Zion. Bummer. Never done the Subway, and its not looking good... Is the hike from the bottom up to the Subway any less risky in such conditions?

[DSTRBD]

Yes its 'less" risky (no really narrow area without high ground) I would think if its not raining on you then there would not be to much worry, I have always just made it a point to get out of the subway section before noon (before any storms can build) I hiked it top down yesterday and the last flash that happened really filled in 80% of the swims so it can be done pretty fast. The the first "swim" is only maybe chest deep and the areas like keyhole are totally full of sand, the bowling ball corridor is still a swim but not very much of it.

So unless its raining in the morning or I could see a big storm coming from the upper trailhead, I personally would still go....just my .02

Oh and there is no hand lines anywhere so take 60 feet of something with you.

[effjammer]

Thanks, DSTRBD. Nice avatar by the way... We'll definitely keep an eye on the weather. To be out of the subway section by noon, what time do you hit the trailhead?

[jman]

Thanks, DSTRBD. Nice avatar by the way... We'll definitely keep an eye on the weather. To be out of the subway section by noon, what time do you hit the trailhead?

Depends on how big your group is and their experience. But typically I would start around 7-7:30am and start boulder hopping easily in the afternoon and be done by 3-4pm.

[Scott P]

I guess I would have to disagree that the Subway should be done in high flash flood danger. It's a fairly long drainage with a fairly high elevation collection area.

I wouldn't want to be in the Subway when it was raining.

It is true that most thunderstorms are in the afternoon, but it's not guaranteed and flash floods can and do hit at all times in the day (or night).

[FONT=Verdana]You would probably be safe if you went tomorrow, but a definite risk is still there.

[FONT=Verdana]Since the canyon will still be there tomorrow or whenever, if it were up to me, I

[DSTRBD]

At this point the danger is marked as "moderate" Where did you see it marked as high? Like I said, unless its raining or you can see a storm coming, I would not worry to much, the drainage for the subway is not a very large area so you can "see" any storm that might cause you trouble. Use YOUR best judgement, The above is the criteria that I use when making my choice.... I have hiked it at least 20 times over the years with never an issue..... Just my .02

[effjammer]

Its been rated as high for most of the day, including when I picked up the permit. Its just been downgraded to moderate--definitely going in the right direction.

[trackrunner]

FYI from the NWS;
Moderate - Localized slot canyons, dry washes, and small streams may experience flash flooding

The Spry & Lodge monster flash flood sure was localized fitting the moderate rating for the day.

Subway's drainage the left fork is not small. Scott is right it's a long drainage.

I had a old roommate get caught by a flash flood right before the exit gully. another group only little further up canyon spent a long night wating for the flood to go down to cross and exit.

[stefan]

my 2

[DSTRBD]

[QUOTE=stefan;412844]my 2

[DSTRBD]

FYI from the NWS;
Moderate - Localized slot canyons, dry washes, and small streams may experience flash flooding [COLOR="red"]Yep, moderate indeed...make an informed decision.. have you ever went out in moderate danger?

The Spry & Lodge monster flash flood sure was localized fitting the moderate rating for the day.
I was in Zion on that day, and it was raining off and on all day. I would not have hiked into either of those canyon's if it was raining or I could see a storm coming (or thinking about coming) as per my "advice" in my first post.


Subway's drainage the left fork is not small. Scott is right it's a long drainage.
Small enough that you can "see" whats falling into it. My point here is that a storm you cannot see 20 miles away is not going to flash the left fork. If its not raining on/near you there is a good chance it will not flash.

I had a old roommate get caught by a flash flood right before the exit gully. another group only little further up canyon spent a long night wating for the flood to go down to cross and exit.

.02

[Scott P]

Small enough that you can "see" whats falling into it. My point here is that a storm you cannot see 20 miles away is not going to flash the left fork. If its not raining on/near you there is a good chance it will not flash.



Actually the drainage is quite long and is probably close to 20 miles long before hitting the Subway (though above the reservoir, runoff wouldn't mean much), though that would be the drainage distance rather than the straight line. It also has many, many fingers. A conservative estimate of the area that drains into North Fork above the Subway is over 14 square miles. Luckily much of that is vegetated though, which would make less dangerous than if it was all slickrock.

Of course whether or not a drainage over 14 square miles is big or small is rather arbitrary. It is big enough however that huge flash floods do come through (of which the huge logs that come and go are evident) and that a flash flood could hit you fast before you know it.

[stefan]

this was posted here a little while back but it's worth seeing again (filmed Aug 4, 2008)


http://www.youtube.com/watch?v=ThMz7S9-co4

[trackrunner]

again I agree with Scott. it's a long canyon system nothing small. in the canyon your view of lava point or wildcat canyon is obstructed making it hard to "see" a localized storm up canyon.

one comment I remember from the spry & lodge/mos/wylie/employee flash flood is they did not "see" it coming. it was a clear sky only minutes before and those drainages are much smaller than left fork.

FYI the last rating for Sunday was not moderate but high for flash flood version issued at 3:57 AM Sunday (http://www.wrh.noaa.gov/slc/forecast/PILversion.php?sid=SLC&pil=RRA&version=1) & there is a current flash flood watch (http://forecast.weather.gov/showsigwx.php?warnzone=UTZ019&warncounty=UTC053&firewxzone=UTZ439&local_place1=Springdale+UT&product1=Flash+Flood+Watch)

[Ryebrye]

The subway is a blast when it's flowing from snow melt - but a flash flood is probably several orders of magnitude higher flow.

I'd find something else to do.

If you do decide to do it, be sure to bring a waterproof video camera that could survive a flash flood so at least your next of kin will have something to remember you by and submit to Man vs Wild.

[taatmk]

I was in Zion this past Thursday and Friday. We had a permit to hike Englestead on Thursday, but aborted the plan due to the Flash Flood Warning issued that day. When we went to the VC to try and get a permit for the next day, Friday Aug 20, the Virgin was overflowing its banks as it went under the bridge near the Visitor's Center. The rangers at the Back County Desk said it had spiked at 170 cfs early that morning. Not a good time to be in any slot canyon....

[effjammer]

All good comments... Based upon the flashflood warning that posted at 3 something this morning, we abandoned the Subway and went to the backup plan and climbed North Guardian Angel. Maybe I'll post pictures later. There was a group going in the Subway in front of us. Apparently more risk adverse. We watched the weather all morning. Probably would have made it through just fine, but when you get in the habit of ignoring obvious warnings--floods, avalanche, severe storm, etc.--eventually its going to catch up with you. Got a raincheck on the permit, so maybe September/Octoberish???