Area Forecast Discussion
Issued by NWS Tiyan, Guam
Issued by NWS Tiyan, Guam
364 FXPQ50 PGUM 050848 AFDGUM Area Forecast Discussion National Weather Service Tiyan GU 648 PM ChST Wed Jun 5 2024 .Marianas Synopsis... Satellite observations show partly cloudy to mostly cloudy skies across the Marianas with a general clearing trend through the afternoon observed. A few isolated showers linger across the region. Combined seas are generally between 4 and 6 feet, mainly composed of trade-wind swell and wind waves. && .Discussion... The scattered showers and isolated thunderstorms that impacted the Marianas earlier today have mostly dissipated. The main concern will be the mid to upper level circulation that is approaching the Marianas from the east. Satellite imagery shows a few squalls near and to the south of the circulation. Isolated showers and isolated thunderstorms will be possible tonight as the circulation nears the Marianas. A lull is expected beginning Thursday and into the weekend with isolated showers possible across the region. An uptick in precipitation will be possible early next week as the Tropical Upper Tropospheric Trough (TUTT) pivots over the region. && .Marine... Combined seas range between 4 and 6 feet and could increase into the 5 to 7 foot range by Thursday night. On Friday seas will begin to diminish again with seas dropping to the 3 to 5 feet range by Saturday. Thunderstorms will be possible tonight before a lull is expected this weekend. Thunderstorms look to return to the region early next week. && .Eastern Micronesia... An Inter-Tropical Convergence Zone (ITCZ) fragment has been generating scattered showers and isolated thunderstorms between Kosrae and Pohnpei during the day. Latest model guidance shows the (ITCZ) building back south of Majuro on Thursday, then to south of Kosrae around Saturday and generating periods of scattered showers and isolated thunderstorms through most of the weekend. Models then show the ITCZ fragmenting and eventually dissolving early next week before rebuilding again around the middle of next week. Benign sea conditions and light and gentle trades are expected to continue through at least early next week at Pohnpei and Kosrae. For Majuro, gentle to moderate trades are expected through Friday, becoming light to gentle this weekend into early next week with benign seas conditions. Altimetry passes this afternoon show combined seas between 5 and 7 feet east of Majuro and between 4 and 6 feet at Kosrae and Pohnpei. && .Western Micronesia... The Tropical Upper Tropospheric Trough (TUTT) Cell north of Yap State is generating scattered showers and isolated thunderstorms at Yap and Palau today. Model guidance shows the TUTT cell will continue to move west-southwest and away from Palau late Thursday into early Friday morning allowing shower and thunderstorm activity to decrease. A trade-wind trough over Chuuk and upper level support from a TUTT cell east of the Marianas that is generating scattered showers and isolated thunderstorm north of Weno will push west of the State Thursday night. A trade-wind pattern pattern will develop with weak troughs generating periods of isolated showers through early next week. Benign sea conditions and light and gentle trades are expected to continue for Chuuk, Yap, and Palau through early next week. Altimetry passes this afternoon show combined seas mostly 2 to 3 feet. && .GUM WATCHES/WARNINGS/ADVISORIES... GU...None. MP...None. Marianas Waters...None. && $$ Marianas: Williams Micronesia: Kelly