Wednesday, August 12, 2015

Coho Ho Ho Rally 2015 - Brads Weather and boat reports August 12th

Congratulations to Steve Lewis and the crew of s/v Manatee!
First boat to San Francisco from the fleet of 2015!

Way to go Steve!

Here's Brads Weather Brief:

Brad's Coho ho ho weather August 12 2015, 12:00 PDT

As I typ this there is thunder and lightning going on outside my office!

There is a short term aspect to this forecast.  The NWS has issued a weather statement regarding thunderstorms in the coastal waters from about the Columbia River South to Tillamook.  By the time this forecast gets out they may have passed, but I suspect there will remain a chance of thunder storms through Thursday.   North Star is the only boat that may be effected by this.  With thunderstorms there can be Gusty winds likely to 30 knots for short duration.   Lightening is also a factor.

For the larger scale pattern the upper level low will be effecting most the forecast area until late Thursday.  Late Thursday and in to Friday the pacific high will strengthen as the upper level low exits to the NE and dissipates inland.  The weather models show a Pacific High that is well entrenched and fairly stationary well off shore at about 43N 150W.  The high is currently about 1028 mb.  The models have it strengthening to 1037 mb by late Saturday which is fairly impressive height for the Pacific high.  Also impressive is how stationary it appears it will be.
With the upper level low exiting a more typically pattern should come into play with thermally induced low pressure inland at Northern California and high pressure offshore.  Though the high is forecast to stay well offshore it is going to be strong enough that the pressure gradients are likely tighten up enough to have upper end small craft warnings or even possible lower end gale warning for parts of the Southern Oregon and Northern California Coast starting Saturday.   In this scenario with the high so far offshore often times in the waters closest to the coast (within 10 miles) relief can be found in significantly reduced winds.  The seas typically remain very bouncy.   Based on the weather models the strongest NW winds look to be from Cape Blanco to Cape Mendocino.

For the Strait of Juan de Fuca (SJDF) onshore flow should persist with Westerlies.  Today and tomorrow should be fairly mellow with stronger onshore push beginning Friday.  Winds will tend to be diurnal in nature with more wind in the Afternoon and evening hours.

Four Day Forecast:


SJDF – Light wind to 10 knots to the west with the potential of building winds to 20 knots in the evening.  Small chance of thunderstorms

Cape Flattery to Newport OR – North to NW winds 0-10 knots backing around to the S to 10 kts in the evening.  The exception here is North half of Washington coast winds are forecast to remain out of NW and blow as high as 20Knots with gusts to 25.  Chance of thunderstorms North part of Oregon South part of Washington.   Seas mixed swell to 3'

Newport OR to SF – Generally light winds, shifting to the South by the evening.  Potential for stronger southerly winds gusting to as high as 20 knots from the South right at Cape Mendocino.  Seas mixed Swell to 3'.  Chance of showers in some places.

Thursday August 13

SJDF – diurnal winds lighter in the morning 5-15 out of the west, building 10-20 in the afternoon and up to 30 knots out of the West in the evening.  Wind waves 0-5' depending on windy it is.

Cape Flattery to Newport OR – S to SW winds to  10 knots except the vicinity of Cape flattery where it looks to be NW To W winds to 15 knots.  Seas, Swell 3' or less from mixed directions.

Newport Oregon to SF -  SW winds to 10 knots from Cape Blanco north, with winds shifting more W to NW from about Mendocino South.  In between the capes?........Maybe South, maybe N wind maybe no wind.  What ever direction not likely to exceed 10 knots.  Seas – Swell not exceeding 3'.

Friday August 14

SJDF – West winds to 10 knots building to as high as 25 knots in the afternoon and evening

Cape Flattery to Newport – W to NW wind 5-20 knots with more wind in the Northern part of the area.  Swell should start to increase to as high as 4' from the NW.  Wind waves 2' or less.

Newport to SF – Starting to get interesting.  Wind should increase throughout the day with strongest breeze filling first in the Southern portion of the forecast area and moving North.  Winds will be from the NW with a wide range of speed depending on location.  Offshore more than 10 miles out speeds could be as high as 25 knots with higher gusts.  From Cape Blanco North it should be lighter on Friday perhaps to 20 knots.  Within 10 miles of the coast winds should remain lighter, for the most part not exceeding 15 knots.  Seas: Rapidly building what they call combined seas to 8' with a wave period of 7 or 8 seconds. 

Saturday August 15

SJDF West winds to 10 knots building to 20 in the afternoon and evening

Cape Flattery to Newport – NW wind 10-20 with higher gusts possible.  Winds should be lighter 10 miles or closer to shore to 15 knots.  Seas, Swell 4-6' from the NW at 7 to 8 seconds with building wind waves to 4'.

Newport to SF – Should be blowing pretty good by now.  NW winds, sustained 20-30 with higher gusts (wouldn't be surprised if some 40 knot gusts occur).  Strongest winds will be between Cape Blanco and Cape Mendocino.  Winds should be less 10 miles or closer to shore, likely staying below 20 knots.  Seas, Waves 12' at 9 seconds.  NOAA hasn't posted It yet but there will likely be small craft warnings for hazardous seas showing up in their forecast for the Saturday Sunday time frame.

Reminder:  I mentioned this when I spoke last month.  Wave Height forecasts are for the average of the top 1/3 of the waves.  The majority will actually be smaller, but………maximum wave height can and will be taller up to twice as tall.  So when the forecast calls for 12' seas.  There will be the occasional 24' wave. J

Sunday August 16

SJDF – West wind 10 knots building to 20 knots for the afternoon and evening

Cape Flattery to Newport – NW winds 10-20 knots.  Seas NW swell to 5' with wind waves to 3 to 4'

Newport to SF – Identical to Saturday.  NW winds 20-30 with higher gusts.  Combined seas 12' at 9 seconds.  Strongest winds between the capes.


Brad Baker   l   Swiftsure Yachts
2500 Westlake Ave N. Suite F   l   Seattle, WA 98109
Office: 206.378.1110    Cell: 206.920.7147   l   Fax: 206.378.1124

Boat Reports
From Steve Lewis August 12th, 05:15 hrs

Clear sky and calm seas now. Dense fog at Pt Reyes.  San Francisco looms 20 miles SE. No traffic. We hope to sail in, Cody @helm.

View the location or send a reply to Stephen Lewis:

Stephen Lewis sent this message from:
Lat 37.766082 Lon -122.825538

From Steve Lewis August 11th:

We finally have full sunshine on day 6! Wind is variable 0-5 kn. Waves 1-2ft. Very few boats out here.

View the location or send a reply to Stephen Lewis:

Stephen Lewis sent this message from:
Lat 38.558762 Lon -124.020282


Humpback whale sighted at 0820 PDT.

View the location or send a reply to Stephen Lewis:

Stephen Lewis sent this message from:
Lat 38.829868 Lon -124.3

No comments:

Post a Comment