Saturday, 19 October 2013

November Warmer.... core of cold shifts west

A +AAM transport has occurred over the pacific basin during the past 10-15 days... which has aided in the development of a very warm pattern east of the rockies.
We saw this pattern at 200mb since october 1st:
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The poleward AAM transport was well established during this timeframe. I added a red arrow to illustrate this event better. This pattern favours eastern IO convection which has been helping enhance the west pacific tropical "flare up".
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Now this is where it gets interesting... the GEFS has a very strong MJO wave moving into phases 8/1. This pattern usually coincides with negative EAMT and frictional torque anoms. We are seeing the opposite pattern currently.
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Given typical progression of the GWO, what should happen next is an increase in easterlies between 30N-30S, eastern u.s troughiness favoured for the rest of october and an MJO wave moving towards phases 7,8 and 1 for the first half of november. This shifts the core of the coldest air over the northern rockies and interior west, with some intrusions into the great lakes/midwest at times. An increase in convection is likely over the central pacific/dateline area given the pattern. Euro weeklies/JMA agree with this overall pattern evolution. If a CCKW can coincide with the GWO, this would help increase confidence on developing convection over the central pacific. Keeping a close eye on the wave developing between 60-120E. Lets see if the euro shifts to this type of MJO setup... right now the ensemble members are all over the place with the ENS mean parked over the null phase.

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