Forecast as of:
Personal Weather Stations [Add your weather station!]
There are no weather stations in your area, find out more information!
Area forecast discussion National Weather Service tiyan GU 752 am chst Friday Oct 9 2015 Synopsis... pgua Doppler weather radar shows only a few showers moving through the marianas waters. The VAD wind profile reveals north winds of 5 to 9 knots through the lowest 3 thousand feet of the air. && Discussion... deep tropical convection is still located to our south at around 10n. The monsoon trough feeding into Tropical Storm Choi-Wan has now morphed into some sort of middle-latitude baroclinic feature. Most likely the monsoon trough will now re-form along that line of convection. Overall the weather will be pretty laid back the next several days...looks like the monsoon trough will move a little closer resulting in an increase in cloud cover. The main story will be seas...check the marine section for details. && Marine... with ritidian and tanapag buoys both still in the 9 to 11 foot range...had to extend the Small Craft Advisory from 6 am to 6 PM today. There is still an impressive fetch of north winds on the west side of Choi-Wan as it undergoes extratropical transition. Both the small craft and high surf advisories may have to be extended again...this will be the main forecast problem for the day shift. && Eastern micronesia... a weak monsoon trough has reestablished north of micronesia near 16n from north of far western micronesia eastward to a tropical disturbance centered south of Wake Island near 17n167e. In response...a convergent band of fresh west to northwest winds has also formed north of Chuuk...Pohnpei and Kosrae between 8n and 12n. Meanwhile...the sub-tropical ridge near 25n is also showing signs of strengthening. This should gradually cause the monsoon trough to sink southward over the next few days. Therefore...expect showers and thunderstorms associated with the convergent band to reach Chuuk later today...Pohnpei and Kosrae by this evening. The monsoon trough curves southeastward from the disturbance near Wake Island...passing through a weak circulation centered just north of Majuro at 12n170e to beyond 180 at 10n. Diverging surface winds south of the circulation center should provide a brief period of less shower coverage for Majuro today. As the circulation and trough shift southward tonight...converging west to southwest winds near the center will bring back wet weather to the capital. A developing frontal boundary currently near Japan is going to move slowly eastward during this weekend. It might gradually weaken the sub- tropical ridge and allow the monsoon trough and circulation to lift back northward. If so...improving weather is possible for the entire region starting early next week. Both latest satellite altimetry and ww3 model output suggest long- period north swell generated by former Tropical Storm Choi-Wan has built further this morning. This will cause surf to reach hazardous levels across Chuuk and Pohnpei states today. Surf should stay at hazardous levels through at least Saturday night. && Western micronesia... reasoning for the Chuuk forecast is included in the eastern micronesia discussion due to a similar monsoon pattern. Despite modest monsoonal winds across the Republic of Palau and Yap state...model guidance reveals possible presence of middle-level dry air. Latest sounding data from Koror does show a hint of dryness between 450 and 300 mb. This trend should support an isolated shower regime for both locales through Saturday. As the monsoon trough moves southward closer toward 10n...weaker winds near the trough might introduce fair weather by Saturday evening. Toward midweek...the chance of showers over far western micronesia could increase as the circulation currently north of Majuro tracks westward. Long-period north swell produced by former Tropical Storm Choi-Wan will maintain hazardous surf across the Republic of Palau and Yap state through this weekend. Both swell and surf should begin to subside early next week. && Gum watches/warnings/advisories... GU...high surf advisory until 6 PM chst Saturday for guz001>004. Marianas waters...Small Craft Advisory until 6 PM chst this evening for pmz151>154. && $$ Stanko/chan