NASA MARINE WEATHERMAN & METMAN CLIPPER

You might need an antenna rail mount, see Nasa spare parts

For many years commercial vessels have received weather forecasts via radioteletype (RTTY) from the German National Weather Agency (DWD). Whilst a few intrepid yachtsmen have tuned into this excellent service, with a general purpose HF receiver connected to a personal computer, results have often been disappointing.
Weatherman combines a synthesised HF receiver, a powerful computer and a high contrast display to form a complete, reliable, stand alone RTTY receiver. Unlike Navtex, which is an international service for navigational and meteorological warnings, weatherman is dedicated to receiving weather forecasts.
DWD operates on a 24 hour continuous schedule and broadcasts continually on several frequencies simultaneously. This helps to cope with the radio propagation and reception conditions which vary with time of day and the distance from the transmitter.
The DWD service is free to yachtsmen but must not be used for commercial purposes.
The daily schedule includes times of day, frequencies and areas of coverage. The user can program Weatherman to record information only from areas of interest. The memory is able to store several thousand lines of text. Details of further Atlantic coverage together with the latest schedule are available from http://www.dwd.de. 
An excellent website with details RTTY, Navtex and HF radio weather services can be found here:http://weather.mailasail.com/Franks-Weather 

For a yachtsman planning a voyage, the ability to predict the weather is essential. 
The rate of change of barometric pressure and history of wind speed can be an invaluable indicator of imminent conditions.

Many sailors rely on low cost domestic barometers, which are inaccurate, have low resolution and very poor history. Several quality paper recording instruments exist but are delicate, fiddly to use and rely on paper which can jam when damp. The MeteoMan overcomes all these problems. It provides an accurate, high resolution barograph recording in excess of five days data on barometric pressure and wind speed. It is easy to use, reliable, rugged and draws very little power from the boat's battery.
The Meteoman is available with an optional NMEA Wind sensor which provides wind direction, wind speed and external temperature. The Meteoman provides reliable meteorological information for the yachtsman. The main display shows the wind speed and direction, the ambient temperature and the barometric pressure.
To assist in predicting future trends the unit also displays a precision barograph and an anemograph showing barometric pressure and wind speed for the previous five days.

In addition to the meteorological functions the unit includes a marine chronometer, a stop watch, a race countdown timer, display of internal temperature and battery voltage.

MeteoMan can be connected to an NMEA Clipper Wind system where it will get wind speed/direction data via the Clipper wind output.

NMEA Wind Sensor supplied with mounting brackets and 20 metres of two core screened cable.
NMEA 0183 sentences: Wind speed/direction MWV Temperature XDR