000 AXPZ20 KNHC 060900 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Jan 6 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... Gulf of Tehuantepec Gale Warning: A tight pressure gradient over southeastern Mexico continues to support gale force N-NE winds in the Gulf of Tehuantepec. Gale winds are expected to persist until Sunday morning, then continue below gale force through Sun evening. NE swell generated by the persistent strong winds will propagate downstream, with seas 8 ft or greater reaching beyond 10N and westward to beyond 100W tonight. Please refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. A strong baroclinic low pressure system is located near 27N131W with a pressure of 1010 mb. A cold front extends southward to 16N132W. An Ascat pass about 12 ago highlighted an extensive area of strong E-SE gale force winds E and SE of the low center reaching to near 127W, and strong to near gale force N-NE winds within about 120 nm NW of the low. Latest scatterometer data shows strong outer winds but did not sample the center. Expect gale force winds are still present, but model guidance shows the low weakening during the next 24 hours. Satellite imagery shows widespread rain with embedded scattered showers from about 23N to 26N between 126W-129W. This activity is lifting northward. With favorable upper support in place, the low will remain vigorous during the next 36 hours. Seas are expected to be 10-15 ft E- SE of the low and building to 12-16 ft in the NW quadrant. Please refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section above for more details about the ongoing gale force wind event in the Gulf of Tehuantepec. Looking ahead, another gale wind event is possible in the Gulf of Tehuantepec early next week as high pressure builds behind the next cold front forecast to move into the Gulf of Mexico. NW swell will propagate into the offshore waters off Baja California Norte Tuesday, with seas building to around 13 ft by Tue night. Elsewhere, relatively tranquil marine conditions are expected during the period. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Winds will pulse to 30 kt in the Gulf of Papagayo into tonight, then diminish Sunday. Light to gentle NE-E winds will prevail elsewhere to the N of 09N, with gentle to moderate S to SW winds expected S of 09N. REMAINDER OF THE AREA... Please see Special Features section above for details regarding a gale force low center near 130W. A 1011 mb low is analyzed near 13N131W. Divergence aloft between a sharp upper trough that stretches from 32N135W to 21N140W is supporting scattered moderate convection within 120 nm of the low center. The low will likely dissipate later today, but a surface trough will remain in the area through early next week. 8 to 10 ft seas north of 20N west of 130W will subside through early next week, ahead of another round of NW swell 8 ft or greater expected by mid week. $$ Mundell