 Meteorologist – a scientist who studies the weather; they make observations to use on weather maps and to make weather forecasts  Modern-day weather forecasts are based on computer weather models  Different models may produce different predictions  These models cannot predict the weather perfectly, therefore meteorologists use more than one model and make predictions accordingly

 National Weather Service – issues weather advisories when severe weather is observed or could occur  Weather Watch – prepare for severe weather that is observed or could occur in your area  Weather Warning – severe weather conditions exist in your area and you should take immediate action

 Weather Station Model – created by meteorologists, they contain information about the weather at a specific location  These are provided by meteorologists from all over the world  They are uniformly written so any meteorologist can read them  They are updated 4 times daily

 If the barometric pressure starts with a 0-4 add a 10 to the front and a decimal between the last two digits.  If the barometric pressure starts with a 6-9 add a 9 to the front and a decimal between the last two digits.  Look at the barometric pressure on the previous slide. It starts with a 9 (998). They added a 9 to the front 9998, then put a decimal between the last two digits to get millibars.

 Climate – the average of all weather conditions over a long period of time (30 years) The Three Major Climate Zones on Earth

 Tropics  Fall between 23.5º North (Tropic of Cancer) and 23.5º South (Tropic of Capricorn) latitude  Always receive the most direct rays from the sun  Warm temperatures year round

 Polar Zones  Fall between the Poles to 66.5º North and 66.5º South latitude  Always receive indirect rays from the sun  Cold temperatures year round  Temperate Zones  Fall between the Tropics and Polar Zones  Weather generally changes with the seasons  In the summer the sun’s rays are more direct so it is warmer and in the winter the rays are less direct so it is cooler

 Large bodies of water – have a moderating effect; coastal areas are warmer in the winter and cooler in the summer  Mountains – act as barriers over which winds must flow