NAAPS Model run: 00Z 16 April - 00Z 21 April

**FOR ADDITIONAL INFORMATION AND GRAPHICS, SEE HTML VERSION.**

Asia:

Surface observations show dust being reported throughout Takla Makan on the 16th.

Over the next five days, the upper level trough fills and a shortwave ridge forms upstream 
at 45N-60N, 60E-90E by the 18th.  Dust is lofted each day in the Gobi and/or Takla 
Makan, but the dust concentration and optical depths are not as high.  The dust plumes 
barely make it out over the Western Pacific.  The signature wrapping and northeastward 
transport are absent.  Little dust is lifted on the 18th under the SW ridge.  An upper 
level disturbance cuts below the ridge to loft dust in The Takla Makan on the 19th and 
continues to loft dust in the Gobi on the 20th.  

Pacific:

Wed. 16 Apr:  With the associated weather system, optical depths drop to zero near the 
Central Coast.  A branch of higher optical depths (0.2-0.4) splits at 125W and spreads
north and south of the cold front.  

Thu. 17 Apr:  Modeled optical depths rebound to 0.1-0.2 throughout the day after the 
passage of the front.  An imbedded plume with AOD = 0.2-0.4 aligns with the backside of
the trough along 125W.  

Fri. 18 Apr:  0.1-0.2 optical depths located along CA coast and over parts of CA.  Higher 
AODs (0.2-0.4) are approaching from northwest (40N, 130W).  By late afternoon, 
the higher AOD plume has reached the OR/CA border and angles backward to the SW 
(30N, 140W).  

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Sat. and Sun. 19-20 Apr:  All day 0.2-0.4 optical depths are over central CA and 
over the coastal waters. 
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ALW 1600 PDT April 16, 2003