000 AXPZ20 KNHC 171004 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri May 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 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia near 08N75W to the coast at 08N78W and continues from there to across western Panama and southern Costa Rica to 11N90W to low pressure of 1010 mb at 10N101W, then to 08N110W and to 06N120W, where latest scatterometer data indicates that it transitions to the ITCZ and continues to 05N130W and to beyond the area at 06N140W. Numerous strong convection is seen 30 nm of the trough between 97W and 100W. Scattered strong convection is within 90 nm north of the trough between 93W and 97W. Scattered moderate to strong convection is seen 30 nm of the trough between 101W and 102W. Scattered moderate to isolated strong convection is within 120 nm south of the ITCZ between 106W and 109WS, and also within 60 nm south of the ITCZ between 103W and 106W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening cold front stretches from eastern Nevada southwestward to the far northern Gulf of California, to across Baja California Norte and to well west of these waters as a dissipating front to near 23N129W. Weak high pressure remains over the area north of about 18N. The resultant present gradient is bringing moderate to fresh northwest to north winds off Baja California. Light and variable winds are over southern Gulf of California, while moderate west to northwest winds are elsewhere across the Gulf, with the exceptions of strong west gaps winds from 29N to 30N west of 114W and strong northwest winds occurring north of the front. Waveheights are in the range of 4-6 ft over the offshore waters, except for slighter higher waveheights of 5-7 ft north of 27N. Waveheights are in the 4-6 ft range over the far northern Gulf of California and 2-4 ft elsewhere over the Gulf. Smoke from agricultural fires over southern Mexico is leading to hazy sky conditions over the offshore waters between Manzanillo and Puerto Angel. For the forecast, the winds offshore Baja California will increase to fresh to strong speeds later this morning as the gradient tightens in response to high pressure centered well to the west of the area that will build southeastward across the forecast waters behind the weakening cold front as it moves east of the northern Gulf. Combined waveheights will build to the range of 7-10 ft off the coast of Baja California mainly north of Cabo San Lazaro late Fri through Sat. This will primarily be due to southwest decaying swell in the region, but with the added factor of shorter period northwest swell that will propagates through these waters. Hazy conditions are expected to continue along and near the coast of Mexico from near Puerto Angel to Manzanillo through at the upcoming weekend. Another cold front will move across Baja California early on Mon brining another round of northwest swell to the waters off Baja California through next week, and strong gap winds to the northern Gulf of California by late Tue. Moisture attributed to the weak low pressure presently located well to the southwest of the Gulf of Tehuantepec may possibly begin to impact sections of southeastern Mexico and the Gulf of Tehuantepec early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A weak pressure pattern will maintain generally gentle onshore wind flow across the region through Sat before moderate to fresh offshore gap winds develop across the Papagayo region. Large cross-equatorial southwest swell will build the waveheights to the west of Ecuador tonight and through early next week. Agricultural fires continue over northern Central America. However, the low-level southerly flow is generally keeping the associated smoke over land and no significant impact on visibility is occurring over the offshore waters at this time. REMAINDER OF THE AREA... A weakening cold front extending from the southwestern US to 32N112W, to 31N114W and 26N120W, where it is dissipating to near 23N129W will move across the waters north of 20N through this evening. Weak high pressure is analyzed north of about 18N and west of 115W. The gradient between the high pressure and lower pressure in the tropics is allowing for generally moderate to fresh northeast to east winds to exist south of the ridge. The cold front will continue to weaken through today as continues eastward away from much of the area. A second cold front will reach near 32N140W by Sat, and move east-southeastward reaching northern Baja California on Sun night. Winds with this front are forecast to be in the moderate to fresh range. A large set of northwest swell will follow in behind the front through early next week. Waveheights with this swell are forecast to be in the 8-10 ft range. Elsewhere large cross-equatorial southwest swell will build seas to the east of 120W Fri night through early next week. $$ Aguirre