La Vagabonde's crossing

[Cherod]

Should that high not bring some warmer winds .?

[atoll]

Originally Posted by Cherod

Should that high not bring some warmer winds .?

high pressure brings cold dry air,low pressure warm damp air
i would expect temps to go from about 24C to about 14c as they get closer to the azores.

interesting to see how the jet stream is feeding that cyclone,still think sebastian will head north -NE along the trough line

https://www.netweather.tv/charts-and...6.50,48.57,712

[Budawang]

Originally Posted by Breaking Waves

>>"When you sail in cold weather - or big winds - there are a few comforts that make it all so much more manageable."

They are going to get colder night watches here soon - northerly winds and being further north.

It's a vivid memory from various N Atlantic passages - some nights bitterly cold and some others quite pleasant for no particular obvious rhyme or reason.

Any of you experts at windy.com - can you get actual nighttime low temps for offshore positions?

Currently 21 Celsius. Not going below 17 Celsius over the next couple of days.

[conachair]

Originally Posted by Breaking Waves

Any of you experts at windy.com - can you get actual nighttime low temps for offshore positions?

Ship not too far in front tallies up well with the ECMWF temperature forecast --


Doesn't look too bad for next few days, though 5am tired in a stiff breeze can still feel pretty chilly even if not too cold ...

[Cherod]

Originally Posted by atoll

high pressure brings cold dry air,low pressure warm damp air
i would expect temps to go from about 24C to about 14c as they get closer to the azores.

interesting to see how the jet stream is feeding that cyclone,still think sebastian will head north -NE along the trough line

https://www.netweather.tv/charts-and...6.50,48.57,712

I really meant the wind which is coming up from the south now , or soon , looping round from African coast , things may change considerably by time they reach the Azores !!

[Breaking Waves]

this is a quite useful easterly tack they have made.

But they don't want to sail into that dark red boundary in front as there is a gale up there.

I thought it would be fast enough moving to not allow them to catch it, but their speed has been higher than I expected and I believe (although have not checked) the system movement seems a bit slower than expected. So they have been catching the front (edit - that could just be the boat position is updating but the front position is not between model runs - IDK how either predict wind or Windy handle their displays between model runs - static or extrapolate ?).

They either need to slow down further, or tack north. The routing would say north, but it really does not understand the 'slow down' approach.



next GFS update is in about half an hour and next euro update in about 3hrs. GFS has been fine but the euro model has been systematically a little more reliable.

[Cherod]

Latest predict 16.50 ( gmt ) shows pretty close to the stronger wind , looks same direction just somewhat stronger , yes maybe she / they will turn N for a few hours yet .

[atoll]

Originally Posted by Cherod

I really meant the wind which is coming up from the south now , or soon , looping round from African coast , things may change considerably by time they reach the Azores !!

i think "cold front" that they are sailing along is probably a bit of a giveaway for their current conditions.
sea water temp is about 22C,air temp 21C probably dropping by 5 deg at night,so 16C,wind chill in 30 knots will make it feel like 12-14C.

considering they a week ago were in 30-32C it must feel like it is freezing for them!

as to distance from the azores,they are virtually at the lattitude of the azores,which is what matters ,at 36N,the azores is 37N

[TeddyDiver]

Originally Posted by Breaking Waves

this is a quite useful easterly tack they have made.

But they don't want to sail into that dark red boundary in front as there is a gale up there.

I thought it would be fast enough moving to not allow them to catch it, but their speed has been higher than I expected and I believe (although have not checked) the system movement seems a bit slower than expected. So they have been catching the front (edit - that could just be the boat position is updating but the front position is not between model runs - IDK how either predict wind or Windy handle their displays between model runs - static or extrapolate ?).

They either need to slow down further, or tack north. The routing would say north, but it really does not understand the 'slow down' approach.

Attachment 203502

next GFS update is in about half an hour and next euro update in about 3hrs. GFS has been fine but the euro model has been systematically a little more reliable.

According Windy the front seems be moving fast to ENE, and they should also to enjoy the westerlies. Slowing down would turn the winds towards north and dropping close to 5kt saturday morning.

[Cherod]

Originally Posted by atoll

i think "cold front" that they are sailing along is probably a bit of a giveaway for their current conditions.
sea water temp is about 22C,air temp 21C probably dropping by 5 deg at night,so 16C,wind chill in 30 knots will make it feel like 12-14C.

considering they a week ago were in 30-32C it must feel like it is freezing for them!

as to distance from the azores,they are virtually at the lattitude of the azores,which is what matters ,at 36N,the azores is 37N

From what I can see they are about to change from one system into another , initially southerly system , surely a wind from the south will be warmer than the one originating from the North ??

[atoll]

Originally Posted by Cherod

From what I can see they are about to change from one system into another , initially southerly system , surely a wind from the south will be warmer than the one originating from the North ??

only really if it is passing over land otherwise seawater temp will be the prime factor midocean,warm air rises,and cold air sinks,so local temps will be more inline with their geographic position and ocean temp in the longer term.
cooler air might be trapped briefly with a front and warm air with a ridge or vice versa,but sun and cloud cover will dictate the mean air temp over seawater temp

[Cherod]

( as of latest predict at 17.50 gmt ) Maybe maybe maybe , that westerly is moving above then and they can continue as they are and the next front ( gale ) might have moved N E a bit and they can ride the tail if it ( well someone did say the thread is for speculation ! )

[Cherod]

Originally Posted by atoll

only really if it is passing over land otherwise seawater temp will be the prime factor midocean,warm air rises,and cold air sinks,so local temps will be more inline with their geographic position and ocean temp in the longer term.
cooler air might be trapped briefly with a front and warm air with a ridge or vice versa,but sun and cloud cover will dictate the mean air temp over seawater temp

I bow to your greater knowledge of mid ocean environment. But it is looking good for them

[Breaking Waves]

Looking at the latest GFS run and I find the data on the current local conditions to be a bit muddled.

latest GFS does say that the 'front' edge is 100nm in front of them (and moving away), which means if they want they may be able to continue east for a while (as long as the wind angle allows). I trust this with some confidence because frontal edge can be seen both by pressure and clouds.

GFS says they should be in westerly winds, but I think from their course they are clearly in SWly winds. So I think the GFS grib detail on winds just behind the front is muddled a bit.

This will probably all resolve as the low passes over them and the clutter in the suction just behind the front moves away.

The bigger picture is pretty much the same - purple is the lastest routing, orange the prior one. Nothing complicated is happening at the moment and the plan would be just to work east, throw in a little north when it is easier, at a comfortable pace.



I have marked in the forecast (GFS) position of the low below them and put in measurement of the distance to the boat when it crosses their routing - black circle boat and red circle low = 780nms in front. Which is a good safe distance. OFC that assumes this track is somewhat correct - and atoll is right . . . it is always possible it will not be.

[atoll]

Originally Posted by Cherod

I bow to your greater knowledge of mid ocean environment. But it is looking good for them

last time i crossed west to east during mid summer as soon as we got to their lattitude and picked up the westerlies it was 18C.....felt absoulooooutly freezing considering it was 30C when we left the week before,and we have inside steering!