National Weather Service Raw Text Product

776 
FXPQ50 PGUM 050849
AFDGUM

Area Forecast Discussion
National Weather Service Tiyan GU
649 PM ChST Tue May 5 2020

.Marianas Synopsis...
A trade-wind disturbance that brought scattered showers this morning 
has moved into western Mariana waters. Satellite shows mostly clear 
skies east of the region while scatterometer data shows moderate 
trade winds. Buoys show seas of 4 to 6 feet.

&&

.Discussion...
Rain gauges across the Marianas show that the trade-wind disturbance
brought up to three-quarters of an inch of rain to much of the 
Marianas last night. NUCAPS soundings along with satellite imagery 
show dry air moving into the Marianas. This dry air will keep any 
rain that does form isolated and short-lived.

The 00z run of the GFS continues to show increased showers over the 
Marianas by Sunday while the earlier 18z run was more in line with 
the Euro keeping convection south of the Marianas. However, both 
models still indicate increasing moisture near the region. For now
the forecast remains unchanged with increasing cloud cover Sunday and
Monday.

&&

.Marine...
Moderate trades will persist through the next 5 days, and seas will
change very little. A slight decrease in seas is expected Wednesday
then seas will return to the 4 to 6 ft range.


&&

.Eastern Micronesia...
Isolated showers and thunderstorms prevail across the eastern half of
Micronesia this afternoon. Models show increasing trade-wind 
convergence over the area. This will cause scattered showers and 
isolated thunderstorms over Pohnpei and Kosrae Wednesday through 
Friday and Wednesday through Thursday night at Majuro. The 
convergence will persist near Majuro which will produce another
episode of scattered showers and isolated thunderstorms at that 
location on Saturday. 

Satellite altimetry and Wave watch data show seas will continue to 
be high enough to produce hazardous surf on east facing reefs of 
Kosrae through tonight. 

&&

.Western Micronesia...
Afternoon satellite imagery showed an area of scattered showers and
isolated thunderstorms near Palau. This is probably the result of 
convergence just east of a surface trough that is near Palau. The
scattered showers and isolated thunderstorms will continue through
part of the evening. Drier air to the east will filter in and 
decrease shower activity by midnight.

A circulation is found southeast of Yap near 3N141E. Models keep the
circulation weak and show it drifting over the western half of 
Micronesia eventually passing near Palau. GFS has the circulation 
passing near Palau Sunday while ECMWF is much earlier with passage 
near Thursday. ICON model has the circulation passing over this 
location this weekend. Despite the timing of the passage of the 
circulation, models generally agree on the placement and timing of 
the shower activity.

Low-level convergence north of the circulation was causing scattered
showers to the east of Yap this afternoon. This area of scattered 
showers will move over Yap starting Wednesday and persisting through
Friday. Thunderstorms were not observed with this area this afternoon
but expect them to develop by Wednesday. As the circulation moves 
closer to Palau, scattered showers and isolated thunderstorms will 
prevail there Wednesday night through Sunday. 

Trade-wind convergence is causing scattered showers and isolated
thunderstorms over Chuuk this afternoon and this will persist through 
tonight. These showers will push further south of this location and 
only expect isolated showers and thunderstorms Wednesday through 
Thursday. The convergence will increase bringing in a second round 
of scattered showers and isolated thunderstorms to Chuuk Thursday 
night and Friday. The area of convergence will remain close enough to 
Chuuk so as to keep skies mostly cloudy and generate isolated showers 
and thunderstorms Saturday and Sunday. 


&&

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

$$

Slaughter/Ziobro/Aydlett