Drought in Guam, July 1 to 30, 2024

Area Forecast Discussion
National Weather Service Tiyan GU
501 PM ChST Sun Jun 30 2024

.Marianas Synopsis...
Satellite imagery is showing increasing clouds and showers this
afternoon. A few lightning strikes were observed west of Guam. Latest
altimetry and Ritidian buoy data are indicating seas of 3 to 5 feet.

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.Discussion...
A disturbance to the southeast of the Marianas will push across the
region through tomorrow. Latest CIMSS MIMIC Precipitable Water is
showing a over 2 inch values approaching the CNMI and over 2.5
inches approaching Guam. Have scattered showers for Tinian and Saipan
through tonight and for Guam and Rota through tomorrow. While the
upper-level support for thunderstorms has diminished and the model
Galvez-Davison Index (instability) is marginal, have included a
slight chance for thunderstorms as there have been a few strikes
observed earlier to the west of Guam. For the rest of the period,
multiple disturbances will pass near to south of the Marianas.
Expect upticks in clouds and showers, especially for Guam and Rota,
where moisture will be deeper and convergent flow will be more
prevalent.

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.Marine/Surf...
Gentle to moderate trade winds and combined seas of 3 to 5 feet will
continue this week. Some gusty winds and choppy seas are possible at
times through the week near heavier showers and thunderstorms,
especially over Guam and Rota waters, as a couple of disturbances
pass near to south of the Marianas.

A moderate risk of rip currents will continue along east facing
reefs, with a low risk along all other reefs. Little change in surf
and rip risk expected through the week.

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.Eastern Micronesia and Chuuk...
Developing ITCZ is producing spotty showers and is expected to
remain spotty as the models show the ITCZ remaining weak with the
TUTT moving out. Thus, lowered the probability of precipitation (POP)
slightly from the previous forecast. Tuesday, models indicate a
localized increase in showers along the leading edge of the ITCZ near
Pohnpei around Monday night, then to Chuuk Tuesday, then fizzling
out before it reaches Yap. The heavier showers look to pass north of
Pohnpei and Chuuk but will bring scattered showers for them Monday
night Tuesday. An increase in shower potential is expected late week
for Majuro and possibly for Kosrae as convergent tradewinds develop
over by the Marshalls and move across the region.

Seas of 4 to 6 feet were observed by altimetry near Majuro and
Kosrae. Not much change is expected for marine conditions. Gentle to
moderate trades are expected at times.

&&

.Western Micronesia for Palau and Yap...
The near-equatorial trough continues to produce some showers nearby
Koror's waters. Latest model run shows that heavier showers are
expected to develop west of Koror near the disturbance this evening,
and we should also see convective activity increasing along the near-
equatorial trough to bring scattered showers tonight for Koror and
Yap. Scattered showers are expected for tomorrow also, but should
slowly trend down to partly cloudy with isolated showers some time
tomorrow. After a brief lull, incoming showers from the east are
expected to cross both Koror and Yap around mid-week.

Seas of 3 to 5 feet were observed by altimetry near Koror and Yap's
waters, and buoys reported around 4 feet. Not much change is
expected for marine conditions. Mostly gentle trades are expected,
becoming moderate at times.

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.GUM WATCHES/WARNINGS/ADVISORIES...
GU...None.
MP...None.
Marianas Waters...None.

&&

Marianas: Slagle
Micronesia: Hong