National Weather Service Raw Text Product

929 
FXZS60 NSTU 230006
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago  AS
106 PM SST Sat Feb 22 2020

.Forecast Discussion...

Tropical Storm Wasi became disorganized last night as it passed
through Savaii yesterday evening and weakened as it passed south
of American Samoa overnight. As of this afternoon, the center of 
the system continues to move southward. According to JTWC and the 
Fiji Meteorologicial Service, the track will continue in that 
direction for the next few days. Since the damaging winds from the
tropical storm will also move away from the territory, the 
Tropical Storm Warning has been cancelled for all of American 
Samoa. However, a Wind Advisory remains in effect through the rest
of the night winds to reach to the Wind Advisory criteria, around
30 mph, during periods of potential heavy rain throughout the
evening.

Even though the severe winds remain the south of American Samoa,
the monsoonal trough will provide additional rain to the area. The
territory received plenty of rain overnight last night and through
most of this past week. Landslides have been reported in the area
and the additional rain may trigger more as the current visible 
satellite imagery shows a band of rain close to the region. Global
models show that mid-level moisture will stay in place through 
the evening. This is because the monsoonal trough will continue 
to direct moisture from the north during this time. Therefore, we
will extend the Flash Flood Watch through early tomorrow. We will
continue to monitor the convective showers to the north later 
this evening and will cancel the Flash Flood Watch, if warranted.

The monsoonal trough to the east of American Samoa on Monday will
remain in that position through the mid week and will weaken as it
will lack proper surface convergence for persistant heavy
rainfall. A weak ridge will enter the region that will give the
territory light and variable winds by midweek. 

As for now, global models do not show any evidence of tropical 
systems developing in the new week. However, we still currently
have low to mid strength wind shear along with warm sea surface
temperatures in the region which makes favorable conditions for 
development in the region. However, the shear tendency is rising,
which will help reduce any development in general, and the 
convectional showers to the north/northwest of the territory are 
not showing signs of development. Also, JTWC (Joint Warning 
Typohoon Center) does not have an invest in the region.

&&

.Marine...

The latest information from the PacIOOS shows seas have subsided
to around 7 feet. The High Surf Warning has been cancelled, 
however a High Surf Advisory is now in effect. As Tropical Storm 
Wasi continues to move southward, this will generate building seas
for tonight. Even though periods are expected to be short through
tonight, the higher sea heights will cause surf to reach up to 12
feet at times for the southern shoreline. This advisory will last
through tonight. Seas are expected to ease to below advisory 
levels for the beginning to mid week next week. A Small Craft 
Advisory is now in effect and will remain through early Monday.


&&

.PPG WATCHES/WARNINGS/ADVISORIES...
A Wind Advisory is in effect through Saturday night.
A High Surf Advisory is in effect through Saturday night. 
A Flash Flood Watch remains in effect through Sunday.

&&

$$

LaPlante