Storm on the Horizon

Take a look at this impressive system which will bring 23 ft waves to the NW Coast by the weekend.

BY ERIN JOHNSON

We have strong weather headed our way; here are some of the forecasts for this massive low pressure system.

This is a map of the forecasted pressure on Thursday.  To help put this into context, here’s a little background on how to read these maps.

The lines are called isobars, and they indicate the pressure measured at sea level. The closer together these isobars are, the greater the change in pressure over a specific area.  Wind is air moving from high to low pressure, so the greater the pressure change, the greater the winds.  You can also get a general idea for the wind direction based on the isobars.  Wind blows with low pressure on to the left and high pressure on the right in the northern hemisphere, and is generally within 15-40 degrees off the direction of the isobars.

Other things to note: The center of the low pressure system (indicated by the L) is 947 mb, keep in mind that average sea-level pressure is 1013 mb. This is a very strong low. Also, this map gives temperature in degrees Celsius indicated by the color changes, so you get that information as well.

Another interesting forecasting tool is the NWS wavewatch3 models. Take a look:

Check out the height of these waves! The color indicates height in meters, so in the first map that maroon color is roughly 43 ft. (!)  The waves are able to get this big because of the combination of high winds over a long period of time with a large fetch (space for waves to build).

The second map shows the wave heights when they reach our coast. Now they aren’t 43 ft, but these waves are 7 meters or about 23 ft; Still substantial. If you have a chance to get out to Ocean Shores on Saturday you’d get a pretty good show.

This is a remarkable weather system, and I’m interested in seeing how it pans out. If you’d like to see an animation of the wave height, go to this website-

http://polar.ncep.noaa.gov/waves/main_int.html

Set the drop boxes to “latest model run”, “North Pacific Hurricane (reg)”, “wave heights”, and “animation”. Then just hit “go”. Pretty cool.

Also, I’m following Cliff Mass’s weather blog on the right, check in with that for his take on the system. He’ll give updates as the storm progresses.