Marine Weather - Coastal

Jack DaleISPA Yachtmaster Offshore Instructor Evaluator

Sail Canada Advanced Cruising InstructorASA Advanced Coastal Cruising / Catamaran Instructor

IYT Yachtmaster Coastal Instructor

Outline Weather Systems West Coast Weather

Areas Reporting Stations Local Weather Hazards

The Marine Forecast VHF Internet

Other Weather Sites

Weather Systems Low Pressure System High Pressure System

Low Pressure System Warm air in centre

rising Rotates counter-

clockwise in northern hemisphere

Tracks from west to east

Low Pressure System Isobars show lower

pressure toward centre Warm air rising Usually two fronts

Warm Cold

Most extreme Tropical depression Hurricane

Warm Front Warm air rides over

cold air Falling pressure Rising air cools Moisture condenses Clouds form Rain

Warm Front Profile Temperature

increases with passing of front

Sky may clear

  Before Passing While Passing After Passing

Winds south-southeast variable south-southwest

Temperature cool-cold, slow warming steady rise warmer, then steady

Pressure usually falling levelling off slight rise, followed by fall

Cloudsin this order: Ci, Cs, As, Ns, St, and fog; occasionally Cb in 

summerstratus-type

clearing with scattered Sc; occasionally Cb in summer

Precipitationlight-to-moderate rain, snow, sleet, or drizzle

drizzle or noneusually none, 

sometimes light rain or showers

Visibility poor poor, but improving

fair in haze

Dew Point steady rise steady rise, then steady

 

Cold Front Cold air forces warm

high up Rising air cools May create

thunderstorms

Cold Front Profile Severe wind shift

Direction Strength

Temperature drops

  Before Passing While Passing After Passing

Winds south-southwest gusty; shifting west-northwest

Temperature warm sudden drop steadily dropping

Pressure falling steadily minimum, then sharp rise rising steadily

Clouds increasing: Ci, Cs and Cb

Cb Cu

Precipitation short period of showersheavy rains, sometimes with hail, 

thunder and lightningshowers then clearing

Visibility fair to poor in haze poor, followed by improving good, except in showers

Dew Point high; remains steady sharp drop lowering

Reading Wind Barbs

Cloud Cover

Forecast AreasBowie

Explorer

Queen Charlotte Sound

Central Coast McInnes Island to Pine Island

Queen Charlotte StraitW Coast Vancouver Is. North

W Coast Vancouver Is. South

Johnstone Strait

Georgia Strait N of Nanaimo

Georgia Strait S of Nanaimo

Haro StraitJuan de Fuca W, Central, E

Howe Sound

Reporting Stations

VHF Forecast Technical Synopsis Local Area Forecast Extended Forecast Local Conditions Notices to Shipping Wave Forecast

Technical Marine Synposis Location of

Low Pressure Systems High Pressure Systems Ridges of High Pressure Troughs of Low Pressure

Local Area Forecasts Today and Tomorrow

Wind Precipitation

Strong Wind Warning only in Cruising Season

Local Areas Strait of Georgia, North of Nanaimo Strait of Georgia, South of Nanaimo Howe Sound Haro Strait Juan de Fuca Strait

East Entrance Central West Entrance

West Coast Vancouver Island South

Wave Height Forecast Forecast Values

Wind Wave Swell Combined

West Coast Vancouver Island South

Extended Forecast Next Three Days Areas May be Combined Listen for Wind Shifts

Intensity Direction Passage of a Front

Local Conditions Automated Reports

Winds and Barometric Pressure Sheringham Point to Sand Heads

Ocean Buoy Reports La Perouse Bank

Local Conditions Lighthouse Weather Reports

Visibility, Winds, Seas, Remarks Estevan Point to Trial Island

Automated Weather Reports Juan de Fuca Wind, Barometric Pressure, Seas (buoys) Cape Flattery to Ogden Point

Local Hazards

SymbolsStrong Winds

High Waves

Steep Waves

Weather

Web Sites Sail Flow

http://www.sailflow.com Big Wave Dave

http://http://www.bigwavedave.ca/ Weather Underground

http://www.wunderground.com/

Web Sites Environment Canada – Marine Weather

http://weatheroffice.gc.ca/marine/index_e.html

Predict Wind http://www.predictwind.com/

Smartphone Apps Weather Eye Passage Weather

Other Resources