Tropical Weather Discussion
Issued by NWS
Issued by NWS
275 AXPQ20 PGUM 280113 TWDPQ Tropical Weather Discussion National Weather Service Tiyan GU 1113 AM ChST Fri Jun 28 2024 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... None. ...OTHER WEATHER SYSTEMS... NEAR EQUATORIAL TROUGH... A Near Equatorial Trough (NET) originates near the southern Philippines, entering the area of responsibility near 5N130E and extends southeast, to then exit the AOR near EQ137E, staying well south of the main islands of Palau and Yap Proper. Pockets of moderate convection occurring within the NET and along its northern periphery where trade convergence is enhanced, across the main islands of Palau but south of Yap Proper. The NET will linger and drift northward over the coming days, possibly transitioning to a weak monsoon-like trough, with convection increasing for Palau and Yap. TRADE-WIND TROUGHS... A pair of westward-moving trade-wind troughs are helping to focus showers and thunderstorms. One southwest of Chuuk extending northwest towards Yap Proper, and another between Chuuk and Pohnpei. While these troughs and attendant convection will continue west, satellite-derived precipitable water products show a band of increased moisture between 2N and 10N that will help convection to gradually redevelop over the weekend as the ITCZ becomes more established. TUTT... A Tropical Upper-Tropospheric Trough (TUTT) stretches from 18N130E eastward to a TUTT low north of the Marianas, then northeast and exiting the AOR near 25N148E. Showers and thunderstorms are beneath the TUTT cell north and west of the Marianas and southeast of Iwo To. The TUTT cell will continue to drift slowly west southwest over the coming days and weaken slightly, with attendant convection gradually diminishing. OTHER SYSTEMS... ...ITCZ/TRADE CONVERGENCE... A region of trade convergence is transitioning to an Inter- Tropical Convergence Zone (ITCZ). The convergence zone starts near the NET to the east of Palau and south of Yap Proper eastwards across Chuuk, Pohnpei and Kosrae, then south of Majuro to east of the Date Line. Pockets of moderate to deep convection occurring with the convergence zone, especially in the proximity of passing trade troughs. The ITCZ is expected to become better developed through the weekend, with convection increasing across central and eastern Micronesia. ...SHEAR LINE... A weak shear line enters the AOR near 25N163E and extends southwest, ending near 20N147E. A line of low-topped showers are occurring along the shear line, with some better vertical development south of Minami Torishima in the vicinity of the TUTT. The shear line will linger for about 24 hours and then slowly wash out with showers diminishing. $$ Slagle