Excessive Rainfall in the Southern Plains; Extreme Heat Coming to the Southwest U.S.

Heavy to severe thunderstorms may bring areas of excessive rainfall and flooding over parts of the southern Plains through Friday. A Slight Risk of excessive rainfall has been issued. Dangerously hot temperatures are forecast across parts of southern Arizona and far southeastern California Saturday through Monday. An Extreme Heat Watch has been issued. Read More >

055
FXZS60 NSTU 110059
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago AS
159 PM SST Tue Jun 10 2025

.DISCUSSION...
Upper air data (RAOB) from this afternoon (11/00Z) show an
inversion at around 850 mb to the mid-levels. A deep inversion
layer as this indicates stable atmospheric conditions over the
area. Also supporting these stable conditions are the open-cell
cumuli clouds moving across the territory from the south,
generated by a high pressure system. The open-cell cumuli clouds
are normally associated with a high pressure system. These clouds
have been recognized as shower clouds, which are able to produce
showers for brief times, from time to time. Model data is showing
the high pressure system migrating to the east and exiting the
region by at least the weekend. By Sunday, easterly winds will
decrease to a moderate flow through at least Monday.

Model data also show another high pressure system to the
southwest, moving east, and generating southerly winds by the end
of the forecast period. These southerly winds together with the
gentle easterly winds will likely converge and create instability
over the area for this time frame.

Thus, expect partly cloudy skies with scattered showers and
breezy trades for the rest of the week. A more gentle to moderate
easterly flow with an increased potential for showers is expected
for the remainder of the forecast period.

&&

.Marine...
Wind driven waves generated by the fresh to strong trades,
produced by a strong high pressure system to the south will
continue to impact south and east facing shores through at least
the weekend. Data from the PacIOOS buoy near Aunu`u show heights
peaking at more than 9 feet with peak periods reaching 12 seconds
from time to time. This prompted the issuance of a high surf
advisory earlier in the day through the weekend. The
inconsistency in the long period data aligns with wind-driven
waves and choppy conditions influenced by local winds versus
swells generated by a storm at a distance. Model data shows this
phenomena remaining for most of the week. By Saturday night into
Sunday, winds will gradually decrease to a moderate easterly flow,
improving ocean conditions for this time frame.

&&

.PPG WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory
Small Craft Advisory

&&

$$

JTAllen