Weather data - what's in a weather chart.

Typical weather data pattern for an approaching depression heading in from the Atlantic - taken from the weather station aboard the now un-manned Sevenstones Lightship. The barometer falls (barometric pressure) as the centre of the low nears the south west - the wind speed increases in the other direction with similar rapidity.

The current sat chart shows the first depression to hit currently at 960 millibars - which is quite low........

twelve hours on and the chart for 0600 tomorrow morning has the low deepening to 943, which is very low - the closer the isobar lines around the centre of the low are together the stronger the wind - looks like the west coast of Scotland is due for a hammering again.

This chart is a print out from a weather fax machine aboard the Breton boat, Le Heidi when she was sheltering in Newlyn on the 11th January 1993 - it shows the 940 millibar depression moving at 25 knots across the Atlantic........

before deepening to one of the deepest lows ever recorded at a predicted 911 millibars it hovered around 915 - unless someone knows different?......

sou'west of Ireland a weather buoy's chart has the wave height dropping over the last 24 hours from a high point of 32 feet around midnight last night to around 20 feet this evening.........

and all hands tied up alongside - though unlike not too many years ago, there's not a single French boat in sight!

At sea, an old saying has it that; wind before rain, set your sails again, rain before wind, sheet your sails in - in other words, if the heavy rain comes first and is followed by a rising wind (generally in this area from the south west) - look out!