The days with minimal difference between high tide and low tide are supposed to be the safest for crossing the Columbia River bar. I wrote a program to compute and plot this difference versus day for the month of August. This plot is shown below. The days with the least flow are around Aug 6th and 20th. The worst days, according to this criteria, are around August 14th and 29th, when high/low differences of 9 feet are predicted. Guess I am going around the 6th!!!
Nice job. This only holds true though if you plan on crossing during an outgoing tide. A big swing flood tide will lay the bar down like a lake (assuming the Ocean is nice, but if it's not you ain't going anyway). The bar can be rough on any outgoing tide, just less likely with the minimal flows of a neap tide (quarter moons).
I'm heading out the weekend of the 4th, fairly large swings. On Thurs the Hi is at 3 am, too dang early for me so I'll sleep in an hit the bar at 10 am at low slack. By Sat the Hi will be bout 5 am so it's up bright and early to be across at o-dark thirty- TUUUUUNNNNAAAA!!! :cheers:
[ 06-12-2003, 12:39 PM: Message edited by: Miss B Haven ]