Obtaining Weather Information At Sea. Mike Reynolds sv Zen Again

Transcription

1 Obtaining Weather Information At Sea Mike Reynolds sv Zen Again

2 Overview Introduc/on Alone In Company Radio Forecasts Radio Fax Weather Data Other Benefits Conclusion Note 1 we re considering beyond mobile/vhf range to shore Note 2 no financial interest in the companies men/oned

3 Introduc/on Weather MaKers Safety (geong there safely) Comfort (enjoying geong there) Progress (geong there quickly) Weather forecas/ng is improving Wind- shadows, sea breezes, currents Access to forecasts is improving Data services geong beker, faster & cheaper

4 Alone First things first - look out the window!!! Log what you see to make trends clear Barometer, wind, sea, swell, current, cloud, temperatures Forewarning of fronts, cyclones, thunderstorms Use radar to detect and track weather Thunderstorms Line squalls Fronts Working at this makes you a beker forecaster!

5 In Company Share the weather! Observa/ons and forecasts Not just cruisers - Sydney Hobart boats must report 40+ knot winds to race control (HF/SSB broadcast) Examples A broadcast on VHF 16 when a strong rain squall hits you in offshore waters can help others prepare Describe via VHF or HF a downloaded forecast to less well equipped boats sailing in company

6 Broadcast Radio Forecasts Needs a MF/HF radio receiver with AM & SSB VMC and VMW transmit voice forecasts on HF/ SSB for coastal and high seas around Australia, four /mes daily for each region AM radio sta/ons can ocen be heard well offshore and provide local weather summaries More adventurously, avia/on weather (VOLMET) for major airports is also broadcast on HF/SSB Similar services from sta/ons around the world

7 Broadcast Radio Fax Needs SSB radio receiver and decoding socware TransmiKed from VMW & VMC on various bands Covers Australia, Indian Ocean, Pacific Ocean and SE Asia regions Fixed daily schedule Analysis and forecast weather charts Sea level and 500hPa weather charts Wave heights and surface temperatures Similar service from sta/ons around the world

8 Weather Data A wide range of data services provide remote access to internet resources Remote access is predominantly via either HF/ SSB or satellite HF/SSB requires a transceiver and a modem Satellite requires either a phone and modem, or a dedicated (ocen data only) terminal Most of these systems offer limited data bandwidth (less than 200 characters/second)

9 Weather Data via HF/SSB Hardware HF SSB transceiver, Pactor modem & PC Socware Airmail Services sailmail.com for mari/me mobile sta/ons US$250pa, ~20 sta/ons, nearest in Sydney winlink.org for amateur operators ( hams ) Free, ~100 sta/ons, nearest in Perth Worth geong your Amateur License!

10 Weather Data via Satellite Satellite Phone Similar to dumb mobile phone Add a data cable/adaptor and socware PC socware provides client, GRIB viewer etc May need external antenna Satellite Terminal Coffee- mug size rail- mount unit with built- in GPS Connects directly to PC (some wirelessly) PC socware provides client, GRIB viewer etc Configurable to send regular posi/on reports Satellite services slowly increasing their bandwidth In a few years mobile- like bandwidths may be truly global

11 Got the kit, what now? The data available depends on the service you use. Some services are free, others paid. Paid usually adds- value eg rou/ng advice (predictwind), currents (/detech) Weather data usually requested using a formaked or a URL address (ie a web page address) Request can be one- off or mul/- day subscrip/on Weather data usually delivered as: Text or with akached GRIB (GRIdded Binary) file Some satellite system s on- board PC socware automates the reques/ng and presenta/on of weather data The background of this slide is a GRIB of NT offshore waters

12 Text Data The service provider simply s you the text of the forecast you requested Socware includes a global catalog of forecasts Airmail uses the saildocs.com service The background of this slide is from: to query@saildocs.com Body of send aus.wa- w You can try this at home!

13 GRIB Files A GRIB file shows one or more weather forecasts in graphical form, similar to hand- drawn weather maps Socware helps you to configure your GRIB: Geographical area Wind, wave, pressure, rain &/or current etc Sequence of forecasts (daily, 12- hourly etc) One- off or sequence (up to 14 days) Vessel movement (moves geographical area daily) The background of this slide is from: to query@saildocs.com Body of send GFS:10N,05N,097E,100E 0.5,0.5 0 PRMSL,WIND You can try this at home too!

14 More on GRIB Files GRIB files can not only be viewed in GRIB viewer socware, they can also be viewed in chartploker socware and used by tac/cal naviga/on socware for route op/misa/on (maxsea, expedi/on etc) An interes/ng parameter is CAPE (Convec/ve Available Poten/al Energy) which shows the likelihood of thunderstorms (CAPE not supported by Airmail) Background of this slide shows CAPE, wind and surface pressure Historical global GRIBs can be downloaded from the NOAA web site (at home for planning purposes) Can download a series of historical GRIBs and animate them in a GRIB viewer. Gives examples of real weather, vice pilot chart averages

15 Currents and Tides in GRIB Files Ocean surface current GRIBs are available eg NOAA provides 5- day average currents on 1 degree grid based on OSCAR satellite data Background shows OSCAR SE Asia currents Note the eddies in the Timor and Arafura Seas!!! Some local /dal surface currents are available eg Solent, San Francisco, Sydney, Auckland TideTech provides a paid service

16 Other Benefits With capability aboard you can also:- Send & receive normal s (no akachments) Friends, family, blogs, yachts in company Officials, event organisers, marinas Send posi/on reports for publishing online eg Sailmail, Winlink, Pangolin, SailBlogs, ShipTrak Send weather reports for use in forecas/ng Pangolin accepts & forwards weather reports With HF/SSB you have long range voice comms Skeds with nearby yachts and volunteer nets HF/SSB DSC provides long range emergency comms SAR authori/es increasingly encouraging satphones

17 Conclusion Many ways of obtaining weather informa/on when at sea, from Mk 1 eyeball to satellite- delivered GRIBs When moving beyond the Mk 1 eyeball and beyond VHF/mobile range there s technology to install and master, and services to select Installing beker comms has many benefits Start your research early

18 Thanks for your attention