Weather

872 
fxhw60 phfo 102052 cca 
afdhfo 


Area forecast discussion...corrected 
National Weather Service Honolulu HI 
1045 am HST Friday Oct 10 2008 


Correction for last paragraph of discussion section. 


Synopsis... 
showery weather crossed over the islands this morning. The overall 
picture this weekend will be normal trade wind weather in which 
scattered showers favor windward and mountain areas. Trades will be 
gentle to moderate in strength. A change is possible on Columbus day 
when an upper low develops just north producing a surface trough 
over the islands. Winds will become light and blow from the south or 
southeast through the middle of the week with the possibility of 
wetter conditions over Kauai on Monday and Oahu by early Tuesday. 


&& 


Discussion... 
the atmosphere is presently stable. The early morning showers are 
nearly clear of the islands except for Kauai. Oahu received the 
largest precipitation amounts through the morning...one third to one 
half inch over typically wetter areas but also a few hundredths in 
central Oahu and over Honolulu. There will likely be another bout of 
passing trade showers tonight. The atmosphere will be slightly 
unstable tonight but no especially significant amount of trade 
shower precipitation is expected through Saturday morning. High 
cloudiness will move over the islands at times through the weekend. 


The large upper trough associated with a storm presently over the 
eastern Aleutian Islands will dip southward over the next few days 
and models have fair agreement in cutting off an upper low about 500 
miles north of the islands Monday night. Models indicate a surface 
trough across the central islands Monday. This will shift the 
surface winds to southeasterly. Accompanying moisture and 
precipitation may affect mainly Kauai and Oahu...Kauai experiencing 
it first as early as Monday afternoon. 


There is disagreement between models on the position of the upper 
low for the Tuesday through Friday period. The European model drifts 
the upper low westward through the second half of next week 
indicating a possible return to trades. But UKMET and GFS differ 
significantly. The GFS slowly moves it west of Kauai weakening it at 
the same time. This would suggest only very weak trades with a 
southeast tendency along with lingering instability and wet 
conditions over Kauai and Oahu for second half of week. Will wait 
for better agreement before departing much from a weak convective 
type forecast that would result from weak trades with afternoon sea 
breeze tendency. 


&& 


Marine... 
the large storm low over the eastern Aleutian Islands will send the 
first large northwest swell of the season. Surf will likely exceed 
the 15 foot high surf advisory threshold for north facing shores 
early Sunday and persist into early Tuesday. 


&& 


Hfo watches/warnings/advisories... 
none. 
&& 


$$ 
Hoag