Wednesday, January 12, 2011

Rapidly rising rivers!

I just had a conversation with the NWS River Forecast Center about our extremely active river flow. Lee’s Camp has only had a little over 2 inches of rain today, and, we have had about an inch or so down here, yet the rivers are showing a significant flow increase. Their thoughts were this may have been a combination of saturation, hardness (frozen still below the surface) and snow melt contributing to the rainfall runoff rates. Current forecasts have the next 12 hr rainfall rates decreasing over the previous 12 hours which would slow the rate of rise and even allow the rivers to crest soon. My only concern is looking at the satellite picture I see some enhanced cloud tops moving onto the coast which would suggest another period of occasional moderate rainfall which would aggravate the situation. He also indicated they were already running new models and the output would be available soon which would update a lot of the river forecasts. The 5 minute look and 10 minute discussion suggested a crest of bankfull around 7-10am tomorrow morning. While the flow rate increases have slowed a little in the last hour, future rain rates obviously will affect this. The most significant rise, as one might expect, has been in the Wilson River that has gone up over 2’ in the last 12 hours, showing a level of 7.32 at 3:30pm. Action Stage is 10.5 and Flood Stage is 12.0.

Bottom line, interest in the North Main area of Tillamook, and low lying areas in Nehalem need to be aware this is taking place. I don’t want my potential 5am call to catch everyone off guard.

Oh, and we are coming into a period of astronomically high tides. The charts show an 8.0 for Garibaldi at 6:45am in the morning, with the next largest high tide at 7:35 Friday morning.

I’ll be watching this tonight and will look at it first thing in the morning, barring any calls overnight from the NWS!

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