1. Seasonal Climate Cycles Seasonal Climate Cycles Sea level pressure

2. Sea Level Pressure Pressure is a measure of the atmospheres weight Lows associated with colder temperatures Highs associated with warmer temperatures

4. SEASONAL CYCLE OF PRESSURE - NORTHERN HEMISPHERE LOOK FOR THE FOLLOWNG: WINTER (OCEANS WARMER THAN LAND) DOMINANCE OF LOWS OVER NORTHERN OCEANS HIGH PRESSURE OVER COMPARATIVELY COLD LAND SUMMER (LAND WARMER THAN OCEANS) DOMINANCE OF HIGHS OVER NORTHERN OCEANS LOW PRESSURE OVER RELATIVELY WARM LAND OTHER TREMENDOUS WINTER/SUMMER PRESSURE CHANGE OVER ASIA (PART OF THE ASIAN MONSOON) GENERAL LOW PRESSURE REGION NEAR THE EQUATOR

5. MAXIMUM DEVELOPMENT OF: ALEUTIAN AND ICELANDIC LOWS SIBERIAN AND BERMUDA HIGHS JAN

6. FEB SIBERIAN HIGH INTENSE OTHER HIGHS AND LOWS WEAKEN

7. MAR ALEUTIAN AND ICELANDIC LANDS WEAKEN PACIFIC AND BERMUDA HIGHS EXPAND AND STRENGTHEN

8. APR LOWS CONTINUE TO WEAKEN, HIGHS TO STRENGTHEN

9. MAY HIGHS DOMINANT OVER OCEAN, LOWS OVER LAND

10. JUN LOWS EXPANDS OVER LAND, ESPECIALLY ASIA

11. JUL MAXIMUM DEVELOPMENT OF 1) PACIFIC AND BERMUDA HIGHS 2) LOW PRESSURE OVER LAND (ESPECIALLY ASIA)

12. AUG HIGHS BEGIN TO WEAKEN

13. SEP HIGHS CONTINUE TO WEAKEN LOWS BEGIN TO WEAKEN OVER NORTHERN OCEANS

14. OCT HIGH PRESSURE WEAKENS OVER OCEANS HIGH PRESSURE STARTS TO DEVELOP OVER LAND LOW PRESURE DEVELOPS OVER NORTHERN OCEANS

15. NOV LOW PRESSURE EXPANDS OVER NORTHERN OCEANS HIGH PRESURE EXPANDS OVER LAND

16. DEC EXTREME AREA OF HIGH PRESSURE OVER ASIA (CENTERED ON SIBERIA, CALLED SIBERIAN HIGH)

17. SEASONAL CYCLE OF PRESSURE - SOUTHERN HEMISPHERE LOOK FOR THE FOLLOWNG HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEMI. HIGH PRESSURE MOST DEVELOPED IN JULY & AUGUST LOW PRESSURE MOST DEVELOPED DEC TO FEB

18. HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEM. HIGH PRESSURE MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEM. HIGH PRESSURE MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEM. HIGH PRESSURE MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEM. HIGH PRESSURE MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTH. HEM. HIGH PRESSURE MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEM. HIGH PRES. MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB HIGH PRESSURE OVER OCEANS ALL YEAR CONTINUOUS BAND OF HIGH PRESSURE IN WINTER HIGH PRESSURE CELLS OVER OCEANS IN SUMMER LOW PRESSURE OVER LAND IN SUMMER LESS SEASONAL CHANGE THAN IN NORTHERN HEM. HIGH PRESSURE MOST DEVELOPED IN JULY & AUG LOW PRESSURE MOST DEVELOPED DEC TO FEB