1. AIR MASSES AND FRONTS

2. AIR MASSES HAVE YOU EVER WONDERED HOW IT CAN BE ALMOST 60 ONE DAY AND THE NEXT DAY IT IS A SNOW STORM? CHANGES IN WEATHER ARE CAUSED BY MOVEMENT AND INTERACTIONS OF THE AIR MASSES, LIKE WHEN THEY MOVE AND MEET! AIR MASSES: A LARGE BODY OF AIR THAT HAS SIMILAR TEMPERATURE AND MOISTURE THROUGHOUT.

3. FRONT FRONT: THE BOUNDARY THAT FORMS BETWEEN DIFFERENT AIR MASSES. 4 TYPES OF FRONTS COLD WARM OCCLUDED STATIONARY

4. COLD FRONT IS CAUSED WHEN A COLD AIR MASS MEETS AND DISPLACES A WARM AIR MASS, BECAUSE THE MOVING COLD AIR IS MORE DENSE, IT MOVES UNDER THE LESS DENSE WARM AIR PUSHING IT UP. IT PRODUCES THUNDERSTORMS, HEAVY RAIN OR SNOW. COOLER WEATHER USUALLY FOLLOWS A COLD FRONT BECAUSE THE WARM AIR PUSHES AWAY FORM THE EARTH’S SURFACE.

5. WARM FRONT A WARM AIR MASS MEETS AND OVERRIDES A COLD AIR MASS. THE WARM, LESS-DENSE AIR MOVES OVER THE COLD, DENSER AIR. THE WARM AIR GRADUALLY REPLACES THE COLD AIR. WARM FRONTS GENERALLY BRING DRIZZLY PRECIPITATION. AFTER THE FRONT PASSES, WEATHER CONDITIONS ARE CLEAR AND WARM.

6. OCCLUDED FRONT A FASTER-MOVING COLD AIR MASS OVERTAKES A SLOWER-MOVING WARM AIR MASS AND FORCES THE WARM AIR UP. THE COLD AIR MASS THEN CONTINUES ADVANCING UNTIL IT MEETS A COLD AIR MASS THAT IS WARMER THE COLD AIR MASS THEN FORCES THIS AIR MASS TO RISE. THIS CAUSES COOL TEMPERATURES AND LARGE AMOUNTS OF PRECIPITATION.

7. STATIONARY FRONT A COLD AIR MASS MEETS A WARM AIR MASS AND LITTLE HORIZONTAL MOVEMENT OCCURS. IT CAUSES WEATHER SIMILAR TO A WARM FRONT-DRIZZLY PRECIPITATION

8. AIR PRESSURE CHANGE IN AIR PRESSURE = CHANGE IN WEATHER BAROMETER: IS USED TO MEASURE AIR PRESSURE H=HIGH PRESSURE=FAIR WEATHER L=LOW PRESSURE=STORMY WEATHER

9. ISOBARS ISOBARS: ARE LINES THAT CONNECT POINTS OF THE EQUAL AIR PRESSURE.

10. WEATHER MAPS IN ORDER TO MAKE WEATHER MAPS FOR THE UNITED STATES, METEOROLOGISTS BASE THEIR INFO ON SEVERAL SOURCES SUCH AS WEATHER BALLOONS, SATELLITES, AND OVER 100 WEATHER STATIONS ACROSS THE US. WEATHER SATELLITES: SHOW IMAGES OF WEATHER SYSTEMS ON TV, THEY SHOW CLOUDS WIND SPEEDS, HUMIDITY, TEMPERATURES ETC.. A WEATHER MAP CAN BE USED TO PREDICT A 5 DAY FORECAST.