Marine Weather - Offshore

Jack DaleISPA Yachtmaster Offshore Instructor Evaluator

Sail Canada Advanced Cruising InstructorASA Advanced Coastal Cruising / Catamaran

InstructorIYT Yachtmaster Coastal Instructor

Outline Station Plot NOAA Weather Fax Grib Files Grib Readers NAVTEX Internet Resources Smartphone Resources

Reading a Station Plot http://www.hpc.ncep.noaa.gov/

html/stationplot_buoy.shtml

Ship Buoy Plot

Temperature

Temperature

The current air temperature measured to the nearest whole degree Fahrenheit.

Weather

A weather symbol is plotted if at the time of observation, there is either precipitation occurring or a condition causing reduced visibility. 

Weather

Weather Symbols

Dew Point

The current dew point temperature measured to the nearest whole degree Fahrenheit.

DewPoint

Wind

WindWind is plotted in increments of 5 knots (kts), with the outer end of the symbol pointing toward the direction from which the wind is blowing.

Wind Symbols

Water Temperature

The current water temperature measured to the nearest whole degree Fahrenheit.

WaterTemperature

Pressure

Sea-level pressure is plotted in tenths of millibars (mb), with the leading 10 or 9 omitted. For reference, 1013 mb is equivalent to 29.92 inches of mercury.

Pressure Tendency

Tendency

The pressure trend has two components, a number and symbol, to indicate how the sea-level pressure has changed during the past three hours.

Pressure Trend Symbols

Swell Information Swell direction, period,

and height represented by a 6-digit code. First two digits = the

swell direction Middle digits

describe the swell period (in seconds)

Last two digits are the swell's height (in half meters).Swell

Information

Swell Information Example 090703 

09 -- The swell direction is from 90 degrees (i.e. it is coming from due east).

07 -- The period of the swell is 7 seconds.

03 -- The height of the swell is 3 half meters. 

Wave Information

Wave Information

Period and height represented by a 5-digit code. First digit

"1" for buoy "2" for ship

Second and third digits the wave period (in seconds)

Final two digits the wave height (in half meters).

Wave Information Example 10603 

1 --   A group identifier for a buoy.06 -- The wave period is 6 seconds.03 -- The wave height is 3 half meters. 

Station Identifier Format of the station

identifier depends on the observing platform.  Ship -- Typically 4 or 5

characters. If 5 characters, the fifth will usually be a digit.

Buoy -- Drifting or stationary, a buoy will have a 5-digit identifier. First digit always a "4".

StationIdentifier

Cloud TypesHigh Cloud

Mid Level Cloud

LowCloud

Cloud Types

Cloud Types

Cloud Types

Station Plot

Note that not all of the possible measurements are included.Wave height is shown as a total (wind wave + swell height)

Station Plot

Weather ParameterWeather Symbol Decoded

Station ID KPZH

Temperature (fahrenheit or celsius) 70 degree F

Present weather thunderstorm

Dew point temperature (fahrenheit or celsius)  68 degree F

Wind speed, direction, sky coverSSW 25 ktovercast

Station Pressure (mb) 048 = 1004.8 mb

3 hour pressure tendency -7 \ = -0.7 mb pressure decrease with steady pressure fall

optional wave height (feet or meter) 11 ft

Sea Surface Temperature (fahrenheit or celsius) 75 degrees F

Ship Observations http://coolwx.com/buoydata/

plotbuoy.php

Buoy Observations http://www.ndbc.noaa.gov/

Station Plots

Buoy Station Plot Ship Station Plot

Ocean Boston - Tanker

Drifting Buoy

Surface Analysis

Weather Fax From NOAA

500 Mb Analysis & Forecast Surface Analysis & Forecast Sea State Analysis & Wave Period

Forecast / Direction Wind / Wave Analysis & Forecast Satellite Photos Gales, Storms and Hurricanes

500 Mb Analysis Upper

air flow 5640-

meter height contour

Isoheights

Surface Analysis

Sea State Analysis Wave

height Average

of Highest 1/3

Meters Wave

direction Ice edge

Wind Wave Analysis Feet

24 Hour 50 Mb Forecast

24 Hour Surface Forecast

24 Hour Wind and Wave Forecast

In Feet

48 Hour 500 Mb Forecast

48 Hour Surface Forecast

48 Hour Wind and Wave Forecast

Meters Ice

Edge

48 Hour Wave Period & Direction

Period in seconds

Arrows show dominant wave direction

96 Hour 500 Mb Forecast

96 Hour Surface Forecast

96 Hour Wind and Wave Forecast

Meters Ice edge

96 Hour Wave period & Direction

Satellite Photos (2)

High Wind and Seas Graphic

Gale force wind and above

Seas in feet

Acquiring Weatherfax Internet SSB radio Weatherfax receiver Sat Phone (email)

Weatherfax Internet http://weather.noaa.gov/fax/

marine.shtml Email FTP Web

Weatherfax SSB

Pt.Reyes(NMC) 4346(except 19z,23Z), 8682, 12786, 17151.2, 22527(19z,23Z) kHz  Radiofax Broadcast

Start Broadcast 0140Z 0655Z 1120Z 1400Z 1840Z 2320Z

Broadcast Schedule

1124Z 2324Z

SSB to Modem to PC to Printer

Weatherfax Receiver PC Chartplotter

GRIB Files A widely used bit-oriented data

exchange scheme is the WMO GRIddedBinary (GRIB) format. GRIB is an efficient vehicle for transmitting large volumes of gridded data to automated centers over high-speed telecommunication lines using modern protocols.

GRIB.US Viewer (Free)

Expedition ($US 1295) Uses

polars Coast

al Curre

nt Wind

Expedition Offshore Also

available in LT (free)

Acquiring Grib Files FTP – Grib.US Email – SailDocs

To: query@saildocs.comSubject: anything

send gfs:40N,60N,140W,120W

Note that this is identical to:send gfs:40N,60N,140W,120W|2,2|24,48,72|PRESS,WIND

gfs = Global Forecast System

File extension .grb

NAVTEX Used in Sea Area

A2 150 miles

offshore Synopsis Forecast Waves

NAVTEX ReceiverPrinterDisplayKeyboard

NAVTEX Introduction & Synopsis

FQCN33 CWVR 281826NAVTEX FOR TOFINO VAE AT 10:30 AM PST MON 28 FEB 2011. VLD 28/18Z-02/08Z,WND(KT), VIS(NM) ABV 1 NM UNL IND, FOG IMPL VIS LESS THAN 1 NM.  SYNOPSIS:28/18Z Q-STNR LOW 990 MB OVR WRN QUEEN CHARLOTTE SOUND. 28/18Z BLDN RIDGE OVR NRN BC INTERIOR.

NAVTEX Local ForecastWEST COAST VANCOUVER ISLAND - N:WNG: GALE.WND: SW15-25. 01/05Z S25-35. 02/05Z SE45.VIS: 28/18Z-02/05Z 0-1 SHWRS/LGT-SN. WEST COAST VANCOUVER ISLAND -S:WNG: GALE.WND: SW15-25. 01/17Z SE15-25. 02/04Z SE35-45.

NAVTEX Local ForecastEXPLORER-NW:WNG: GALE.WND: W25-35. 01/16Z W15-25. 01/20Z V5-15. 02/04Z NE25. EXPLORER-SE:WNG: GALE.WND: SW25-30. 02/00Z SE30. 02/05Z SE45.

NAVTEX Wave ForecastWAVES(M) VLD 28/12Z-02/08Z. WEST COAST VANCOUVER ISLAND - N:3-4. 28/17Z 2-3. 02/02Z 2. WEST COAST VANCOUVER ISLAND -S:3-4. 01/11Z 2-3. EXPLORER:3-5. 01/08Z 3. 01/23Z 2.

Weather Routing Services Herb Hilgenberg

http://www3.sympatico.ca/hehilgen/vax498.htm Free

Commander’s Weather http://www.commandersweather.com/ Gulf Stream analysis as well Fee for service Sample forecast

http://www.commandersweather.com/index_files/Page346.htm

Web Sites NOAA WeatherFax Grib.us Predict Wind

http://forecast.predictwind.com/ Passage Weather

http://www.passageweather.com/ Buoy Weather

http://www.buoyweather.com/

Smartphone Apps Navionics Mobile versions

Passage Weather Buoy Weather