29) Gibraltar

Gibraltar 36° 09N 5°21’W

Weather forecasting and decision-making

While out today I stopped at the Internet café to research weather charts and graphic images.  I download the data on a flash-drive and then we look at the pics on my laptop at the nav station and make decisions.  This next passage from Gibraltar to The Canaries is about 660 miles as the crow flies according to Encarta.  The GPS and the vessel trip log will tell the real story.

We specifically look at wind and wave images and base our decisions on them.  The satellite photo is fairly helpful in determining cloud cover but the size of the wave is the most important thing to us, next, the direction the wave is going, then the direction and velocity of the wind.  The following images are what we used today to make the decision to leave on Wednesday morning.  Keep in mind that these are forecasts.  Keep in mind that they attempt to estimate wave height due to wind induced waves but they don’t necessarily take into account swell.

 

The system west of Spain is still spinning and drawing air into it from the Med.  Here in Gibraltar we experienced the venturi effect of the wind being sucked northwest. 

 

Today’s waves are forecast 9-12 feet heading east.  We are heading west out of Gibraltar and then southwest.  So, anything that comes at us from those directions will put it on our nose and in sailing terms that means uphill; against the wind and against the waves.  Up hill is synonymous with very uncomfortable and sometimes unsafe.  We would not leave port and head into this condition.  Strong winds for today are adding to the seas and the system to the north is still well developed. 

This starts Monday night at 12am and is for 24 hours, Tuesday.  The seas have knocked down to 7 feet and that is a little better but not good enough.  East winds are ok.   

Wednesday at noon the seas are down to 5 feet on the nose and favorable winds.

This is for Wednesday and starts at 12am.  The waves along our route are looking ok and the winds have decreased. 

The waves have knocked down considerably by Wednesday at noon and we plan to leave port this day in the morning.  Although, the winds have increased considerably out of the east.  

By Wednesday at midnight the seas should have knocked down as much as they are going to which is about 4 feet and will be abeam or slightly aft of our quarter.  The winds thru the straight have increased quite a bit and hopefully we will be south of them.  It appears that these winds are what is knocking down the wind waves.