Columbia Bar Question

CohoKen · 01-14-2003, 07:53 PM

I have been across the bar twice in the new boat. But I know it was a good weekend. I need to know just how to tell whether it is wise to go out or not.

I have heard that the ebb tide is the worst, my question is what is the ebb tide exactly? Is it the outgoing tide or low tide?

I know that you guys are the experts and need to pick your brains a little.

lost_sailor · 01-14-2003, 08:00 PM

The tide "ebbs" and "floods." Ebb goes out, flood comes in. In between you have periods of "slack" - it hangs their for a bit (half-hour, hour?) known in common circles as "low slack" or "high slack."

The bar is generally the roughest when the water is running out!

Wiser boaters will provide more details.

pkg40 · 01-14-2003, 08:52 PM

It is a good practice to cross this bar on incoming tides only. You should plan your trip around the tides. A ton of water is going out of that river on a falling tide. When it hits incoming swells the waves can get pretty nasty. This bar routinely has breakers at max ebb on a big tide day. The whole character of the river mouth changes when the flow switches from incoming to outgoing. The effects can be seen in the river to miles offshore.

[ 01-15-2003, 06:42 PM: Message edited by: pkg40 ]

Pilar · 01-15-2003, 08:02 AM

CohoKen, This subject has been discussed in many threads, but none recent.

The change in the river during the tide cycle is simply amazing. Tremendous currents surge through the estuary with each ebb and flood. The peak currents can generate standing waves many times the size of the prevailing ocean swell. This is especially true of the outgoing or 'ebb' tide.

Starting at low tide lets go through the tides for a day. Lets say it is near the full moon and the low is at 7 am. Out on the bar the current has been raging for 6 hours and some of the roughest conditions are present. The swells coming from the open ocean to the west are colliding with the water surging out of the river. The result is breaking waves all through the part of the river between the jetties. These waves can be found all through the river up to the 22 bouy. This is a time to avoid the mouth of the river.

But then the current slows and stops. The waves decrease and as the tide runs back into the river the bar begins to lay down. No more breakers and the waves become organized and begin to follow the prevailing swell. This time of improving conditions right after low tide is when most people choose to cross the bar. As the current picks up to max flood 3 hours after low, schools of bait and birds get pushed into the river.

Conditions continue to improve. I know this is anecdotal but I have noticed that as high tide approaches the weather often changes too. Often as not the wind will drop off and the sun will come out. The water (in the absence of wind) will about noon on a day like this lay down and be calm right through the high slack period. This is a good time to return from your offshore adventure. Conditions are as good as they will be all day.

OK, break time is over and the tide, always changing, stops and begins to go out. The wind freshens and the water in the estuary pushes out towards the bar. By 3 pm, 2 hours after high, the current is strong and the waves are building on the bar. Since this is the afternoon, the wind is picking up as well. Breakers begin to form on Clatsop spit and the area between social security beach and the south jetty becomes a washing machine. Often a rip of conflicting currents will form off the S. Jetty tip. This is a huge hazard to boats returning from the CR bouy as they go north and try to shortcut the channel by cutting in close to the S. Jetty.

At 4 pm the current is at max ebb and the bar begins to break all the way across. If you are returning now, you will have to find a place to be for 3 or 4 more hours before the conditions improve enough for a crossing attempt. As the tide continues to ebb the bar builds bigger waves.

The current begins to subside and the rough bar may not ease up until the ebb tide stops and reverses at 7pm.

So plan your trip to avoid the ebb. Especially the time 3 hours after high right through the low. That is the worst time to cross. Also the size of the tide matters. Subtract the low from the high to get the size of the tide. On days with a big change (8 feet or more) look for more effect from the ebb. Small changes ( 4 ft or less) in tide may not even build a bar.

The flow in the Columbia matters too. Some of the roughest conditions occur in the spring during the runoff from melting snow. This coincides with huge spring tides for a rough bar.

If you monitor the NOAA coastal marine forecast for the Columbia river bar on VHF weather channels, you will be warned of potential bar problems. They frequently post warnings for rough bar during some of the conditions I described above. This is a good resource, use it.

Miss B Haven · 01-15-2003, 08:57 AM

I would only add that the CG at the CR has 3 basic bar rules they normally use (other than their wave/visibility conditions). They may have different criteria (boat size) occasionally but this is what I normally hear.

Open to all craft :smile:
Closed to craft under 30 feet :depressed:
Closed (period) [img]graemlins/berry.gif[/img]

( I left the gobbledy goop about uninspected vessels etc out)

If the bar was in closed on the previous ebb be esp. careful of your timing coming back in. Unless conditions change remarkably while your out you can bet the next tide swing will be the same conditions on the bar (modified only by the height of the tide swing). :smile:

CohoKen · 01-15-2003, 08:22 PM

Thanks for the great information, it will help in determining when I go out. :smile: :smile:

id. painter · 01-16-2003, 07:20 AM

Cohoken, just wondering, what is your boat? id. p.

Miss B Haven · 01-16-2003, 07:24 AM

id - You can click on his profile (or anybodies) and see the boat type (for those who put something in). :smile:

[ 01-16-2003, 01:04 PM: Message edited by: Miss B Haven ]

CohoKen · 01-16-2003, 05:05 PM

id. I got a AW Intruder 20' deep Vee.

Re:Play · 01-18-2003, 09:32 PM

A good place to look at what the bar conditions are is: http://www.wrh.noaa.gov/Portland/

Go to "marine" on the left margine and you can get a lot of info. The latest forecast and the times the bar will be the worst--like was stated earlier.

You can also look at the buoy reports and see what the ocean conditions were for the last 24 hours. If the combination of wind waves and swell height is 8 or more, it is usually miserable to fish, as we spend more time holding on than being able to just stand there.
I fish a 19' Arima and am very comfortable using the 8' combined guideline. Above that it becomes more miserable followed quickly by much more dangerous.

CohoKen · 01-19-2003, 06:53 AM

Thanks Re:Play for the site, very informative.