Sunday, December 10, 2006

Eenie Meanie...Chili Beanie - The Spirits Are About To Speak!

Click to animate. Loop speed = 3 sec / frame

Fast...hi-index flow regimes can/t last forever. If they did...it wouldn/t be Planet Earth where differential sfc heating and orography play key roles in the creation and propagation of weather producing Rossby waves.

Today/s ECMWF progs depict a buckling in the hi-index (zonal) LW flow regime over the PAC early in the forecast period. By D+7...a deep trof b/comes established in the W and a heat ridge bulges over the SE.

This trof-W, ridge-E configuration is not immediately favorable for winter wx along the EC but there/s little reason to think this evolving pattern will become dominant beyond D+7 b/c 1) the forecast five-wave pattern is by definition progressive and 2) we/re in the midst of a moderate +ENSO which is not conducive for persistent SE ridging.

Also notable by D+7 is the lowering (rising) 5H heights over the Azores (Greenland) suggestive of a developing hi-lat block.

Given the hi-amp western ridge just upstream of the cold pool in the full-latitude western trof...the upr LOW could retrograde into a 'bowling ball' as the progressive ridge rolls over then aligns near 125W.

Moose: Eenie meanie, chili beanie--the spirits are about to speak!
Squirrel: Are they friendly spirits?
Moose: Just listen.

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