AIR MASSES AND FRONTS AIR MASSES HAVE YOU

AIR MASSES AND FRONTS

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

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

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

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.

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.

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

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

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

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. .