Storm warnings

Bruce’s Briefs: Wx for 21, 22, and 23 December. Fronts Coming!

Bruce Hedrick Bruce's Briefs 0 Comment
Bruce’s Briefs: Wx for 21, 22, and 23 December. Fronts Coming!

I guess interesting is really an understatement when it comes to describing the weather over the last week. Two high wind events and one tornado, that never happens! Plus in one week we went from being behind in the amount of December rainfall to as of this morning being ahead by about .3 of an inch.

While we will get a brief respite from rain and wind today there are another series of fronts coming ashore Saturday and Sunday. For those of you who are wondering about Christmas Day, it looks like that will be a fairly nice day as in no rain and very little wind.

Click any image to enlarge.

  • December 21 Surface Analysis
  • December 22 Surface Forecast
  • December 23 Surface Forecast
  • December 24 500MB
  • December 24 Surface Forecast
  • December 25 500MB

The chart for today shows the remains of that front that went through yesterday just entering the Bay area with a weak ridge high-pressure developing behind it. Behind that ridge, you have a series of low-pressure systems with the possible development of yet another one off of the Oregon coast.

On the 22nd you can see a  strong low-pressure system (983MB) has developed off of our coast however it will be driven up into BC by that nice ridge of high pressure setting up over the Cascades and running up into Canada.

The really interesting chart is the one for the 23rd which shows the attached frontal system from the low that is going into BC dragging over the Salish Sea with another series of lows developing behind it. In fact, this chart breaks the old Roser Low Count Index* record of 11 by having 14 defined low-pressure systems on one chart. What breaks we get will be few and far between.

Satellite Image

The other factor to be aware of over the coming week will be that will be having the highest tides of the year from now until the 28th of December which when combined with high wind events can cause significant damage and flooding to some shorelines. Since most of our storms come with south winds this shouldn’t be a big deal it’s when the breeze comes from the northeast, north, or northwest that we usually have problems.

Have a great weekend and Holiday Greetings to All and good luck to the Joy Ride Team on the Sydney to Hobart Race. The start, while on the 26th of December down there, means about 1500 hours here on Christmas Day. It will be streaming live on the Internet. 

*The RLCI was developed by Capt Jim Roser as a quick way to gauge the probability of bad weather coming into the Pacific Northwest. The higher the number, the higher the chance of bad weather.

Bruce’s Briefs: Stormy Weather Advisory

Bruce Hedrick Bruce's Briefs, Weather 0 Comment

Plus need a last minute gift for the boater in your crowd? Go to the bottom of this update. *

As my friend Brandon Baker at Elliott Bay Marina reminded me last week, “It is that time of the year!” No, this is not a duplicate of last week, we simply have yet another strong system coming ashore tomorrow. 

It’s not often you get so many colors in the Weather Advisory from the NWS but yesterday’s was particularly colorful and that is usually not a sign of good weather. 

Note especially the deep purple for the coast and the eastern end of the Straits. It’s not for a gale warning, it’s a storm warning, one step below hurricane. So while this won’t be as strong as last Friday it will be right up there. Here’s why; note in the current surf analysis the print right off of our coast, the part that says developing storm. The low just below that may be only 1004MB however it is going to strengthen as it comes on shore.

The chart for today shows why this system will bear watching.

Our innocuous 1004MB low has become a 984MB storm that is now very tightly wound and headed right into central Vancouver Island with an attached cold front extending almost all the way to the Hawaiian Islands. It is moving very quickly and once it hits the coastal buffer zone it will weaken as it moves inland. The other part is that with the current jet stream we have a classic Pineapple Express that will bring plenty of rain and a rising freezing level. That combination can cause low land flooding as our minimal snow back degrades in the rising temps.

The day will come…

So if it’s not going to be as severe as last Friday and I properly secured my vessel, what’s the problem? First off, it may not be that severe but it’s going to be close. Second, in all jostling your vessel has been through, remember that chafe is a relentless enemy and works 24-hours a day on those mooring lines. Remember also that those fenders can be bounced up and on to the dock so those need to be checked as well.

The timeline for this system (done yesterday) is roughly as follows, again, this is not precise so prepare in advance!

Recommended by Bruce and your humble editor.

*I have said recently that the weather is getting interesting however I never thought that would include a tornado in Port Orchard. However, just in time for the Holiday Season, if you need a last minute gift for the boater on your list I would highly recommend the latest edition of Modern Marine Weather by David Burch. I stopped by Starpath in Ballard the other to pick up this book and I must say that is the best work on marine weather I have seen. It is very up to date, very complete, easy to read and understand, and you should probably have a copy at home as well as on the boat. You still have time to pick one up at the Starpath Shop in Ballard at 3050 NW 63rd Street or you can order it online at www.starpathpublications.com.   Highly recommended.

Bruce’s Storm Brief – Don’t be Complacent!

Bruce Hedrick Bruce's Briefs , 1 Comment
Bruce’s Storm Brief – Don’t be Complacent!

Don’t be lulled into complacency by the relative calm we’re currently experiencing in the Seattle area, the wind is coming. It just looks like our coastal buffer zone has once again done its job by slowing the approach of this system and deflecting it into BC. As you can see from the plots of wind speed and barometric pressure at Smith Island, West Point, and Destruction Island, the pressure is still dropping. The other interesting feature of these graphs is the slope of the barometric pressure line which shows how much faster the pressure is dropping up at Smith Island and how much faster the wind speed is increasing. This would tell us that, as we said yesterday, conditions will be more severe along the coast (52 knots at Destruction Island now), in the eastern end of the Straits and the northern end ofAdmiralty Inlet than in the central and south Sound.

Click any image to enlarge.

Right now, it appears the front will pass the coast about mid-afternoon bringing stronger breezes into the central and south Sound with it. This will persist through the early evening before the post-frontal conditions kick in and the pressure gradient begins to ease over the area. The next system will start to show up in the offshore waters early Saturday morning and then in the eastern end of the Straits by midday Saturday. Conditions in the central and south Sound won’t be bad on Saturday or Sunday however you should always check on conditions because there could be pockets of 20-25 knots of southerly.

Click any image to enlarge.

  • West Point 0900 Hours – Wind speed-Air Pressure
  • SMI Readings December 14 Wind speed-Air Pressure
  • Destruction Island Graph Wind speed-Air Pressure

The 48 hour surface forecast still shows what the upcoming week will be light with a succession of low-pressure systems lining up offshore. While they may be deflected to the north of us, the fronts will still drag over our area bringing wind and more rain. Not such good news for the skiers because this next system will drive the freezing level up to over 5500 feet, melting snow and increasing the possibility of some minor flooding in the lowlands.

Interesting times!

Have a great weekend.