Subject : On weather
What prompted this post is reading a current weather forecast and wondering if we are all on the same page as it relates to weather.
Red sky at night, sailor’s delight; red sky in the morning, sailors take warning. What this means to me is that there is a pasage of a low. Lows as in lows in weather tell you allot. Weather systems move from West to East, so if a low is to your west, you are likely to experience deteriorating weather as the low approaches.
So should we keep track of the Barometer readings? Visual observations, such s clouds?
Red sky proverb proves right about 70% of the time.
Here is a recent weather forecast double spaced to make it easier to read.
TONIGHT N WIND 10 TO 15 KT. WIND WAVES 2 FT. NW SWELL 6 FT AT 11 SECONDS.
MON N WIND 5 TO 10 KT WITH GUSTS TO 15 KT. WIND WAVES 2 FT. W SWELL 5 FT AT 10 SECONDS.
MON NIGHT N WIND 5 TO 10 KT. GUSTS TO 15 KT IN THE EVENING. WIND WAVES 2 FT. W SWELL 5 FT AT 10 SECONDS. TUE E WIND TO 5 KT…
BECOMING SW IN THE AFTERNOON. WIND WAVES 1 FT. W SWELL 3 FT AT 10 SECONDS. CHANCE OF SHOWERS. TUE NIGHT W WIND 5 TO 10 KT…
BECOMING SW 10 TO 15 KT AFTER MIDNIGHT. WIND WAVES 2 FT. W SWELL 3 FT AT 10 SECONDS. SHOWERS LIKELY. WED W WIND 10 TO 15 KT…
BACKING TO SW IN THE AFTERNOON. WIND WAVES 2 FT. W SWELL 4 FT AT 10 SECONDS. CHANCE OF SHOWERS AND A SLIGHT CHANCE OF TSTMS.
WED NIGHT W WIND 10 TO 15 KT. WIND WAVES 2 FT. W SWELL 4 FT. CHANCE OF SHOWERS.
THU N WIND 15 TO 20 KT. WIND WAVES 4 FT. W SWELL 5 FT.
FRI N WIND 20 TO 25 KT. WIND WAVES 6 FT. NW SWELL 5 FT.
I don’t now have the correct info to credit the following but here is a description of what the above means in terms of waves described in height and seconds.
Ocean waves are measured in height and period (seconds). Obviously the longer the waves are spaced out for us the better.
Wave height is the distance from a wave’s trough to its crest. The crest is the top of an unbroken wave, the trough is at the bottom of the front of the wave.
Wave period is the amount of time (in seconds) it takes from the moment one wave crest passes a fixed point until a second wave crest passes that same point.
Typically one will hear waves described like, ” It’s 5 ft @ 13 seconds”.
What this means is that the average height of the largest 33% of the waves are 5 ft and that the average period (time between wave crests) of the most prevalent swell is 13
If you are in a boat at sea, significant sea heights are very important. By reading the forecast, such as the one above we now have an expectation as to what we can expect to encounter.