Tropical Weather Discussion
Issued by NWS
Issued by NWS
654 AXPQ20 PGUM 100058 TWDPQ Tropical Weather Discussion National Weather Service Tiyan GU 1058 AM ChST Mon Aug 10 2026 Tropical Weather Discussion for the Western North Pacific between the Equator and 25N from 130E to 180. The following information is based on recent satellite imagery/data, weather observations, radar, and meteorological analysis. ...SPECIAL FEATURES... TROPICAL CYCLONES... Tropical Storm Peilou (13W and formerly named Kujira) continues to churn east across the northern part of Guam`s AOR. It`s currently located near 21N147E, roughly 90 miles northeast of the Maug Islands. Peilou is forecast to strengthen slightly and turn northeast over the next 48 hours. Invest 98W has moved out of Guam`s AOR. For more information please refer to bulletins from the Joint Typhoon Warning Center under WMO header WTPN32 PGTW and from the National Weather Service under WMO header WTPQ32 PGUM. TROPICAL AND MONSOON DISTURBANCES... Newly-formed Invest 90W is passing through the RMI, currently located near 10N169E. This system has had a persistent LLCC for 4 or 5 days now (since before it crossed the Date Line), with equally persistent convection along the western Semicircle of the LLCC for about 36 to 48 hours. The models have also started to pick up on this disturbance. Given all of this, we coordinated with JTWC to invest 90W this morning. This system has held a consistent westward track (270 heading) over the last 4 to 5 days, hugging 10N. The pattern does remain somewhat favorable as it has very warm SSTs of 86 to 87 degrees, and dry air entrainment is not an issue. Conversely, it`s fighting a bit of easterly to northeasterly shear, with vertical wind shear estimated to be in the 15 to 20 knot range. This is moderate/"conditionally" favorable. We expect 90W to continue heading west over the next 48 to 72 hours, despite the models trying to lift it northwest, as it looks to be small/weak enough to not feel the affects of the monsoon trough and tropical disturbances northeast of the CNMI. Stay Tuned! ...OTHER WEATHER SYSTEMS... MONSOON TROUGH... The monsoon trough continues to weaken and retreat west, slightly. It`s currently positioned north of a line from 8N130E to 20N162E, with it becoming the inflow in Peilou once you get east of 150E. It continues to bring scattered showers and isolated thunderstorms to the Marianas and points westward, and this should continue for another day or two. $$ Doll