000 AXPZ20 KNHC 170957 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Mon Jun 17 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 0845 UTC. ...TROPICAL WAVES... A presently ill-defined tropical wave over the western Caribbean Sea along 81W is expected to enter the far eastern Pacific Mon night and may become reinvigorated thereafter. A tropical wave along 111W from 03N to 15N is moving westward at 10-15 kt. A tropical wave with axis along 127W-128W from 03N to 15N is moving westward at about 15 kt. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N73.5W TO 09N80W TO 10N86W TO 07.5N98W TO 11.5N122W TO 10N127W, where latest scatterometer data indicates that it transitions to ITCZ, continuing TO 06N136W TO beyond 06N140W. Widely scattered moderate isolated strong convection is from 05N to 14N between 94W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The pressure gradient between a high pressure ridge west of Baja California and a low pressure trough along the Baja California peninsula is maintaining moderate northwest to north winds across most of the adjacent offshore waters where seas remain in the 4-5 ft range. Winds and seas off Baja California will change little through Mon evening as the ridge remains over offshore waters. Surface low pressure is expected to cover a rather expansive area over the southwestern United States and along California late Mon through Wed as a sharpening mid to upper- level trough moves over those regions. This will result in the weakening of the ridge to the east of 124W, and cause winds to diminish through Wed. Mainly gentle southwest to south winds prevail over the southern half of the Gulf of California. These winds will increase to gentle to moderate southeast to south winds over the entire Gulf today. These winds then become light and variable on Tue and through Wed evening. Fresh south to southwest winds will develop over the far northern part of the Gulf late this afternoon and evening due to daytime heating then diminish to moderate early on Tue. Long-period southwest swell is across the Mexican offshore waters, however the seas will remain in the 5-6 ft range through the middle of the upcoming week. Expect variable winds generally less than 15 kt across the waters between Las Tres Marias and Puerto Angel through mid week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh offshore winds will continue to pulse to strong at night across the Gulf of Papagayo region through the upcoming week, with seas peaking around 7-8 ft downstream of the Gulf. Otherwise, fairly tranquil conditions will persist off Central America under a weak pressure pattern. Gentle to moderate south to southwest flow along with scattered showers and isolated thunderstorms will prevail south of the monsoon trough through much of the upcoming week. Long-period southwest swell propagating through the southern waters will build the waveheights to 9 ft between Ecuador and the Galapagos Islands through the remainder of this weekend. Wave model guidance suggests that new south to southwest swell will propagate through the southern waters west of 85W Tue night through Thu building waveheights there to a peak of 8 ft again before they begin to subside late on Thu. REMAINDER OF THE AREA... A broad high pressure ridge prevails across the northern waters, centered on a 1028 mb high near 37N139W. Moderate to fresh northeast to east winds prevail north of the ITCZ and west of 125W. Latest altimeter data continue to show seas in the 5-7 ft range across most of this region. Overnight satellite data showed fresh NE winds and seas around 8 ft from 12N to 17N west of 134W. Moderate to fresh winds are expected to persist mainly south of 20N into early next week as a couple of weak tropical waves move westward and pass south of the ridge. Long period southwest swell will continue to propagate through high seas areas east of 120W through tonight. Seas will remain 8 to 9 ft south of the Equator through the middle of the upcoming week, as reinforcing southwest swell is expected to reach the far southwestern waters tonight. Expect 8-9 ft seas south of the Equator and west of 100W by Tue. Elsewhere, northwest to north swell will propagate through the far northern waters west of about 125W beginning on Mon night and continuing through Wed night as strong high pressure builds southward to the north of the area, while low pressure lingers offshore of California. Waveheights associated with the N swell will likely build to 8- 10 ft north of 28N late Tue. $$ Stripling