000 AXPZ20 KNHC 300903 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jun 30 2018 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... At 0900 UTC Jun 30: Tropical Storm Emilia was centered at 17.0N 118.6W, or 695 miles SW of the southern tip of the Baja California Peninsula, moving west-northwest, or 285 degrees at 8 kt. The estimated minimum central pressure is 1003 mb. The maximum sustained wind speed is 35 kt with gusts to 45 kt. Easterly shear continues with numerous strong convection observed within 120 nm either side of a line from 18N121.5W to 11N119W. Emily is forecast to continue to move across cooler surface waters and gradually weaken to a tropical depression tonight. Refer to the latest NHC forecast/advisory under AWIPS/WMO headers MIATCPEP1/WTPZ31 KNHC for additional details. A 1008 mb surface low is centered near 10N101W, drifting westward. Scattered moderate and isolated strong convection is observed to the north of the system within 150 nm either side of a line from 13N96W to 10N109W. Environmental conditions are favorable for continued development and this system is likely to become a tropical cyclone during the next 48 hours. Even if the convection does not organize into persistent banding, the tightening pressure gradient will produce easterly winds near gale force north of the center today through Sun, with minimal gale force conditions forecast within 240 nm over the northeast quadrant on Sun night. Strong to near gale easterly winds are forecast south of 15N between 97W and 107W through early Sun. Refer to the latest high seas forecast under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for additional details on this developing gale. ...TROPICAL WAVES... A tropical wave is analyzed north of 07N along 88W, and is moving west at 10 kt. Scattered moderate and isolated strong convection is observed within 75 nm of 11N89W and 05N89W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends west across off the Pacific coast of Costa Rica at 09N84W through a tropical wave along 88W to the tropical low pressure at 10N101W, then resumes southwest of tropical cyclone Emilia at 14N122W to 09N131W where scatterometer winds indicate a transition to an ITCZ which continues west to beyond 07N140W. Aside from the convection associated with T.S. Emilia and the tropical wave along 88W and the surface low at 10N101W, scattered moderate isolated strong convection is observed within 75 nm either side of a line from 03N78W to 08N79W to 12N90W, and within 120 nm either side of a line from 04N87W to 06N97W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features section for details regarding the developing low pressure system centered near 10N101W. A northwest to southeast orientated low level ridge will extend across the Pacific waters west of the Baja California Peninsula through early next week. Light to occasionally moderate winds are expected around this ridge. Gulf of California: Fresh south to southwest winds are forecast along 30N through late this morning followed by moderate winds through tonight. Light and variable winds forecast elsewhere across the gulf waters through Sun. Gulf of Tehuantepec: Extended guidance is suggest strong northerly winds late Wed night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... See the special features section for details regarding the developing low pressure system centered near 10N101W. Gulf of Papagayo: Fresh to occasionally strong offshore winds will occur across and within 150 nm downstream of the Gulf of Papagayo through the middle of next week. Gentle to occasionally moderate easterly winds are forecast elsewhere north of the monsoon trough which is meandering between 08N and 10N, and gentle to moderate southerly winds are forecast south of the monsoon trough through the weekend. REMAINDER OF THE AREA... See the special features section for further details on Tropical Storm Emilia and the developing low pressure system currently near 10N101W. Elsewhere, a surface ridge extends into the area from near 32N136W to beyond 26N118W. Moderate to locally fresh northeasterly winds, and 6 to 8 ft seas, are expected to continue across the area through late Sun. Fresh to locally strong north winds, accompanied by 7 to 9 ft seas, will reach along 32N between 125W and 135W on Sun night. These conditions will propagate south to along 29.5N between 130W and 140W by early Mon, with seas of 8 to 10 ft forecast west of a line from 32N123W to 23N140W, in the wake of a weak cold front passing through the discussion area north of 30N. $$ Nelson