Heat Wave Persists Over the Central U.S.; Significant Flooding Expected in the Northern Mid-Atlantic Tuesday

Dangerous and extreme heat will remain across portions of the Central U.S. this week, persisting across the Mid to Lower Mississippi Valleys, Gulf Coast, Southern Plains and portions of Texas. A heat wave over the Southwest will intensify late this week. Severe thunderstorms and flash flooding will spread from the Great Lakes/Ohio Valley to the Mid-Atlantic and Northeast the next few days. Read More >

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FXZS60 NSTU 280109
AFDPPG

Area Forecast Discussion
National Weather Service Pago Pago AS
209 PM SST Mon Jul 27 2026

.Discussion...
Latest satellite imagery shows the line of showers mentioned in
yesterday`s forecast extending across the Samoa Island chain.
This feature brought an uptick in showers overnight, with rainfall
nearing one inch at Toa Ridge. Expect this line to linger over
the Samoa Islands through Tuesday. Model guidance suggests the
trough will weaken by Tuesday afternoon. However, since the
showers have been delayed by a day, we will continue to monitor
how conditions evolve.

In the meantime, trade winds are still expected to build in the
area Tuesday. Southeast winds of around 15 mph are already
being observed across the area, suggesting the high pressure near
New Zealand extends over the Samoa Islands. This system is
forecast to push the aforementioned showers farther north Tuesday
afternoon and maintain breezy weather through Friday.

By Saturday, the high pressure system is expected to exit the
region. Expect light winds and fair weather through the new week.

&&

.Marine...
Observations from the PacIOOS buoys show wave heights in the range
of 6 to 7 feet with peak periods up to 17 seconds from a southwest
swell. Although wave heights are currently below advisory
criteria (8 feet), both a Small Craft Advisory and High Surf
Advisory are now in effect due to the southwest swell.
Furthermore, seas are forecast to build throughout the week as
winds strengthen in the area starting Tuesday. Wave heights are
expected to peak Wednesday into Thursday due to persistent trade
winds before subsiding over the weekend as winds diminish.

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

&&

$$

TM