Area Forecast Discussion
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
395 FXPQ50 PGUM 161839 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 439 AM ChST Mon Jun 17 2024 .Marianas Synopsis... Satellite imagery is showing partly cloudy skies and isolated trade showers over the Marianas. Latest altimetry data and Ritidian buoy are showing seas of 4 to 6 feet in the waters. Gentle to moderate winds prevail. && .Discussion... Latest model guidance and satellite trends still shows a weak disturbance moving through the area south of Guam, bringing scattered showers to Guam by around noon today. Latest runs show the disturbance moving through a bit slower, maintaining scattered showers through Tuesday morning. By Tuesday afternoon, a dry trade- wind pattern returns to Guam, continuing through the weekend. Meanwhile, the CNMI looks to remain in a dry trade-wind pattern through the weekend. Some gusty winds are possible during the daytime hours today and tomorrow as the gradient is slightly tighter with the disturbance passing through. && .Marine/Surf... Gentle to moderate trade winds with occasional fresh gusts will prevail through the middle of the week, becoming gentle Thursday. Combined seas of 5 and 7 feet will slowly diminish to between 3 and 5 feet by midweek as the trade swell subsides. Scattered showers are expected for Guam waters this afternoon through Tuesday as a weak disturbance passes by to the south of Guam. Isolated thunderstorms possible across the southern Guam waters. A moderate risk of rip currents is expected along north and especially east facing reefs through Tuesday. A low risk will remain along south and west facing reefs. Surf will subside 1 to 2 feet along north and east facing reefs by midweek, dropping the rip current risk to low for north facing reefs. && .Eastern Micronesia and Chuuk... Active weather continues across this region and the Inter-Tropical Convergence Zone (ITCZ) has become better developed overnight. An area of heavy showers is over the Date Line to the east of Majuro, where a pattern of low-level convergence and upper-level divergence is fairly robust. Otherwise, there are several patchy areas of showers and isolated thunderstorms from over Chuuk State eastward across Pohnpei and Kosrae. As stated before, the ITCZ will support areas of showers and a few thunderstorms across the region this week, though minor shifts in the ITCZ may allow for periods of isolated showers for some of the islands. Combined seas of 4 to 6 feet are expected across the region, with some heavier conditions over the northeast Marshall Islands. Seas are not expected to change much this week as the trade swell is expected to change very little. Besides locally stronger gusts near showers and thunderstorms, winds will remain gentle to moderate this week, becoming moderate to fresh at Majuro later this week. && .Western Micronesia for Palau and Yap... Satellite loops indicate a disturbance and possible weak circulation is centered southeast of Koror early this morning at about 5N137E. A surface trough also curves from the disturbance northeastward across Yap State. Westerly winds converging along the south side of the disturbance are causing widespread heavy showers just north of the Equator. Also, divergent upper-level flow around a TUTT Cell well north of Yap was helping to produce patchy heavy showers just north and east of Yap. Models indicate the disturbance will drift toward the west, but very slowly, and unstable weather will likely continue over far Western Micronesia most of this week, especially as active weather could arrive from the east. Combined seas 3 to 5 feet and light east to southeast winds are expected for Yap and Koror through the next few days. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...None. MP...None. Marianas Waters...None. && $$ Marianas: Slagle Micronesia: Simpson