275 
fxpq60 pgum 200852 
afdpq 


Area forecast discussion 
National Weather Service tiyan GU 
652 PM chst Thursday Nov 20 2008 


Synopsis...radar and satellite imagery shows only very patchy 
shower activity this afternoon over the marianas...perhaps a 
little more trade-wind shower activity over Saipan and Tinian 
coastal waters than Guam and Rota. South of 10n a tropical wave 
centered near 144e is moving slowly westward and is expected to 
bring some high cloudiness into the area...but very little in 
regards to shower activity. 


&& 


Discussion...looks like mostly dry conditions will prevail over 
the marianas as evident in both the models and from the satellite 
imagery...especially as seen in the water vapor where the middle- 
troposphere appears very dry over our latitude belt. Models 
suggest perhaps a weak shear line...or an increase in trade-wind 
showers in response to the shear line further to the north....is 
possible late Saturday and into Sunday. This signal is not very 
strong. Later in the week...around Wednesday or Thursday...models 
seem to agree on the approach of a weak disturbance affecting the 
area. However...considering the time frame...wouldn't suggest 
holding your breath on this one until things become more 
obvious...one way or the other...by early next week. 


&& 


Marine...not a whole lot of activity with mostly trade-wind flow 
affecting the area. The arrival of a weak northerly swell is 
apparent in both the GFS and NOGAPS runs of the ww3 by late Friday 
and through the weekend. 


&& 


Fire weather...dry weather and breezy conditions seem to be 
putting this next year's fire weather hazard conditions ahead of 
last year's pace with the kbdi index already approaching 500. 


&& 


Eastern micronesia...conditions have improved for Majuro and 
Kosrae as convergence has slackened. Convergence has moved south 
and west of Kosrae and diminished for Majuro. Stable conditions 
will continue through the weekend. Right now Pohnpei is in a 
relatively clear area with a weak surface trough approaching and a 
favorable upper-level environment for showers. Isolated showers 
tonight will give way to scattered showers in the early morning 
over Pohnpei. 


&& 


Western micronesia...have kept the new forecast pretty much in line 
with the last update. Convergence and associated convection near 
and to the east of a surface trough along 143e continues to be 
draped over Chuuk through tonight. GFS...European model (ecmwf) and UKMET show this 
activity nosing westward and remaining south of Yap through the 
forecast period but pushing into the Koror vicinity over the 
weekend. This is reflected in the pq2. There is a possibility that 
a portion of the surface trough and/or the convergence to the 
north of the trough reaches Yap later Friday or Friday night 
giving Yap a period of scattered showers and a slight chance of 
thunder that is not in the current forecast. 


&& 


Gum watches/warnings/advisories... 
GU...none. 
Marianas waters...none. 
&& 


$$ 


Edson/devita