583 
fxhw60 phfo 240140 
afdhfo 


Area forecast discussion 
National Weather Service Honolulu HI 
400 PM HST Monday Nov 23 2009 


Synopsis... 
a high far to the northeast will maintain moderate trade winds 
through Tuesday. Another high will pass north of the islands... 
resulting in an increase in the trades late Tuesday through 
Thursday. Showers will focus on windward and Mauka sections. 


&& 


Discussion... 
no changes in the forecast logic or illogic from the previous 
discussion. Just forgot to mention in that discussion that around 
middle-week there may be a slight increase in showers...per the GFS 
model. Am not expecting any significant rainfall amounts. 


Previous discussion... 
higher pressure to the north and lower pressure to the south...plus 
the ever-present coriolis effect turning the winds to the right... 
means more trade winds this week. The trade winds will increase a 
little Tuesday night into Thursday when an east-moving high passes 
to our north...tightening the pressure gradient as it GOES. The 
trades will return to light to moderate through Saturday when the 
high moves off to the northeast...then pick up again when yet 
another high passes by to the north. 


A weakening cold front may bring some organization to the showers 
near Kauai next Sunday. Otherwise...showers will remain random... 
favoring the usual windward and Mauka sections with an exposure to 
the east winds. The absence of a destabilizing upper level trough or 
low means that there is little or no chance of significant rainfall 
this week. 


&& 


Marine... 
surf along north and west facing shores will drop below advisory 
levels Tuesday then rise abruptly Tuesday night and Wednesday. The 
second round of surf could require high surf warnings for north and 
west facing shores. The swell will slowly decrease thereafter...but 
surf may remain at advisory levels through the rest of the week. 


&& 


Hfo watches/warnings/advisories... 
high surf advisory until 6 am HST Tuesday for north and west shores 
of Niihau and Kauai...and North Shores of Oahu Molokai and Maui. 


&& 


$$ 


Craig