MJO Shift Drives Colder U.S. Pattern in March

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Chart of the day: ECMWF 30-Day MJO forecast.

Discussion: ECMWF updated their 30-day MJO outlook earlier today. The projection indicates MJO shifts into phase_7 (West Pacific tropics) with increasing intensity over the next 1-2 weeks. During FEB/MAR, a MJO phase_7 favors excessive precipitation in the Central U.S. ECMWF projects MJO to shift eastward across the equatorial East Pacific and toward the Atlantic tropics (phase_8) during March which supports a cold trough in the U.S. likely enhanced by widespread west/north U.S. snow cover.

Week-2 Ahead Forecast valid March 6-13, 2023: Western chill begins eastward shift.

Discussion: The West U.S. chill is likely to advance eastward around the 10th of March inspired by and eastward MJO shift toward the Atlantic tropics. The East U.S. warmth will fade during the second half of the period.

Week-3 Ahead Forecast valid March 13-20, 2023: U.S. cold pattern.

Discussion: A large area of colder than normal climate is projected for mid-March due to an elongated upper trough across the U.S. An expanding snow cover will be necessary to validate the outlook.

Week-4 Ahead Forecast valid March 20-27, 2023: Lingering cold.

Discussion: The upper trough supporting the colder pattern continues although ECMWF may be hanging onto the cold pattern too long.