03/08/2022, 10:22 am EST

Breaking the U.S. Cold Pattern in the Medium-range

The Alaska high-pressure "ridge bridge" guides arctic air cross-polar into a longwave trough over North America the next week or so causing an unusually cold outbreak. However, immediately thereafter the pattern flips warmer.
03/07/2022, 4:03 pm EST

La Nina Is A Little Stronger

La Nina weakened due to emergence of a subsurface Kelvin Wave in the equatorial East Pacific in early February. However, that influence is fading, trade winds are increasing and La Nina has regained some strength the past 2 weeks.
02/28/2022, 1:07 pm EST

East Pacific Kelvin Wave Fading; La Nina Regains Some Strength

During the past 2-3 weeks the convective phase of the Madden Julian oscillation (MJO) has dominated the eastern Indian Ocean/West Indonesia tropics. The general rising air induced by convection along this stretch is replaced by increasing easterly trade winds arriving from the central/eastern equatorial Pacific. The trade wind increase in the central/eastern equatorial Pacific has caused up-welling of cool subsurface water to cause La Nina to gain some strength.