Other Factors: MJO Index

1. Other Factors: MJO Index Madden Julian Oscillation (MJO): A 40- to 60-day period of alternately strong or weak trade winds that normally blow west. It is named after Roland Madden and Paul Julian, two scientists from the National Center for Atmospheric Research who in 1971 were studying wind patterns in the tropical Pacific. For unknown reasons, these tropical winds sometimes weaken, and the Sun-warmed pulse of ocean water that they usually cause to drift west drifts east. As this pulse of warm water, called a Kelvin wave, moves east-from the coast of Africa across the Indian and Pacific Oceans-it carries changed air patterns above it.

2. MJO Data Links Current MJO Data and Archives (CPC) Archived MJO (Historical Images) Click here for current MJO Phase

3. Other Factors: MJO Index When the wave crashes into South America, the water stops, but the air pattern continues over land northeastward, into the Caribbean atmosphere and across the Atlantic Ocean. Before this cycle is complete, another pulse has already started in the Indian Ocean. Scientists are still studying the MJO. Most agree, however, that when the MJO cycle speeds up and warm Kelvin waves pile up in the Pacific Ocean, we have the start of an El Niño. The MJO usually brings flooding rains (also known as the "Pineapple Express") to the Pacific Northwest and California. In an active hurricane season on the East Coast, it can mean several hurricanes within a few weeks, followed by a long spell with no hurricanes. MJO Tutorial Site

4. Other Factors: MJO Index For the East coast of the United States, the impact of the MJO during the winter months is uncertain. We know the MJO goes through phases, 8 to be exact.

5. Other Factors: MJO Index Although much is uncertain, phases 8 and 1 of the MJO appear to be the most favorable for large scale East coast snowstorms due to the above heights (high pressures) over and near Greenland which in turn impacts the negative NAO. Click here for current MJO Phase

6. Other Factors: MJO Index According to HM (Eastern US Weather Forum), MJO does not have to be in Phase 8 all the time to get SECS (Significant East Coast Snowstorms). It is one tool to the general equation. It is not until phase 4-7 when the MJO alignment favors a ridge back east. Click here for current MJO Phase

7. Other Factors: MJO Index 500mb Height Anomalies for each MJO phase for every month

8. Other Factors: MJO Index (Thanks to NWJ)

9. Other Factors: MJO Index (Thanks to NWJ)

10. Phase 4 (March 2007)

11. MJO Phase (Blizzard of 2006)