MJO Inspires More Heavy Rain

Daily Feature: Westerly Wind Burst Emerges
05/12/2019, 12:41 pm EDT
U.S. & Europe/Western Russia Excessive Rain
05/16/2019, 12:09 pm EDT
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Strongest Madden Julian oscillation event of 2019 (so far) emerges

Next inspiration? 3-6 in. of rain California and then the Midwest.

Discussion: The strongest MJO episode of 2019 continues and is gaining intensity (Fig. 1). Among the several high impact weather events inspired by this MJO so far have included drenching rains/flooding in the Mid-South U.S., similarly heavy rains in Southeast Europe and temperatures reaching 85F on the north coast of Central Russia.

Next up? California is whacked by 3-6 in. of rain (could be more) as the Pacific polar jet stream phases with the subtropical jet stream causing entrainment of tropical energy associated with the MJO. That wave of rain which begins tomorrow will sweep into the Great Plains in the form of powerful severe thunderstorms unloading more excessive rainfall this weekend and early next week. The NOAA 7-day rainfall forecast indicates 5-7 in. of rain in California and 4-6 in. in Iowa (Fig. 2).

Fig. 1: Satellite view of widespread MJO-inspired tropical convection with expected amplifying and phasing jet streams to the north to vault heavy precipitation into California later this week reaching the Great Plains early next week.

Fig. 2: The NOAA/WPC 7-day precipitation forecast for the U.S.