000 AXPZ20 KNHC 201023 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Jun 20 2019 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. ...TROPICAL WAVES... A tropical wave is along 89W-90W from 04N to 14N moving westward at 10-15 kt. Scattered moderate to strong convection is noted near the wave from 05N to 13.5N between 87W and 94W. A tropical wave is along 99W-100W from 04N to 13N is moving westward at 10-15 kt. Scattered moderate to strong convection has developed surrounding this wave from 05N to 11N between 95W and 103W. A tropical wave with axis along 121W-122W from 04N to 15N is moving westward at 15 kt. Scattered moderate isolated strong convection is about the wave from 10N to 15N between 117W and 126W, and ahead of the wave from 08N to 15N between 129W and 137W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from a 1008 mb low over northern Colombia westward to 10N85W to 08N95W to 13N111W, to where it transitions to the ITCZ to 10N130W. The ITCZ then continues through 10N140W. Outside of convection discussed above under the Tropical Waves section, little significant convection is occurring. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Overnight scatterometer data continued to show gentle to moderate northwest wind across offshore waters as weak high pressure dominates E of 130W. Overnight altimeter satellite data showed seas at 4-5 ft. Low pressure over the Colorado River Valley will strengthen some Friday, and a surface trough will continue to extend from this low over Baja California. This will cause winds to increase over the northern Gulf of California, producing strong to near gale force SW to W gap winds on Fri night. Farther south, a weak tropical wave will move west across the southern Mexico offshore waters, with little impact in winds and seas, while enhancing overnight coastal showers and thunderstorms. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate breezes will prevail over most of the waters into the weekend. However, fresh offshore gap winds across the Papagayo region will pulse to 20-25 kt through sunrise tonight, and to around 20 kt again Friday night into early next week. These gap winds are due to a tight pressure gradient between high pressure north of the Caribbean sea and the lower pressure associated with the monsoon trough. Overnight altimeter satellite scans showed seas of 4 to 7 ft prevailing as southerly swell will continue to be dominant into the weekend. REMAINDER OF THE AREA... A 1032 mb high remains quasi-stationary well north of the area near 42N139W, with a ridge extending southward to the tropical region west of 125W. South of this ridge, easterly winds of 15 to 20 kt are occurring across the tradewind belt south of 18N, and these trade winds should persist through the weekend. North of 26N, seas of 8 to 10 feet are occurring, due to northerly swell generated in gales off the west coast of the United States. This swell will continue with minor fluctuations for the next several days. Farther south, long-period cross-equatorial swell is causing seas of 8 to 9 feet generally south of 08N. This swell will decay some toward the end of the week, before new swell arrives this weekend, again increasing seas south of 08N to 8 to 10 feet. $$ Stripling