Area Forecast Discussion
Issued by NWS Pago Pago

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FXZS60 NSTU 160127

Area Forecast Discussion
National Weather Service Pago Pago  AS
227 PM SST Tue Oct 15 2019

.Discussion...Satellite data continues to show an area of light
rain showers just north of the islands, expanding and spreading
south into American Samoa this afternoon and evening. IR
satellite cloud top temperatures show that this area of
precipitation is rather shallow and stable, with only light to
occasionally moderate rainfall expected. Overall, based on current
trends will continue to mention scattered rain showers through

The latest vertical moisture profile data and theta-e profile
suggests a much more unstable and moist airmass dropping into the
region through the remainder of the work week. A surface trough
associated with a storm system near New Zealand, and convergening
mid level streamlines (925/850mb) will likely generate an
increase in aerial coverage and intensity of rainfall over the
islands Wednesday and Thursday. Expect there is a chance for
locally heavy rain possible Thursday, as moisture increases
through the entire column.

Will slowly diminish the chances for rain Friday night through
the weekend, as drier mid and upper level moisture develops on
the backside of the eastward exiting surface trough.


.Marine...Current surface and marine observations show winds,
waves and seas are remaining under advisory criteria this
afternoon and evening. Expect marine conditions to remain fairly
stable as an area of high pressure lingers east of the islands.
Some increased surf is possible Wednesday and Thursday as some
wave momentum from the storm system near New Zealand, lifts
toward American Samoa.






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