000 AXPZ20 KNHC 300956 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Jan 30 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 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Strong northerly winds across the Gulf of Tehuantepec has increased to minimal gale force tonight and extend southward offshore to near 14.5N95.5W. These northerly gales will persist into early Wed morning as high pressure ridge builds southward along the eastern slopes of the Sierra Madre mountains behind a cold front moving across the western Gulf of Mexico. This will be a short-lived Tehuantepec gap wind event as the the pressure gradient over southeast Mexico weakens again Wed. This will allow winds to diminish back to fresh to strong force Wed morning, and to 20 kt or less Wed evening. Maximum seas during the gale force winds will build to 10-11 ft by Wed morning. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. Gale from 15N to 19N west of 137W: A prominent deep layer cutoff low is centered east-northeast of the Big Island of Hawaii near 21N151W, and is supporting a surface trough to its east, along about 142W. The pressure gradient between the surface trough and high pressure farther north is maintaining a large area of strong to near-gale force E to SE winds from 09N to 20N W of 135W. Scattered to numerous showers and thunderstorms are active in this area as well. Winds may reach minimal gale force during the next several hours and continue into Wed morning, especially near areas of strong thunderstorms from 15N to 20N between 135W and 140W. These marine conditions are expected to generally persist on Wed, with seas building to 9 to 13 ft, then diminish Thu as the supporting upper low weakens into a trough and lifts northward. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 02N83W TO 05.5N87W TO 03N99W TO 05N119W TO 06N132W TO 11N138W. Scattered moderate to strong convection is occurring east of the low pressure and trough described above, from the ITCZ northward to 16N and W of 133W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Broad and weak ridging extends from 1021 mb high pressure centered near 30N131W through the Revillagigedo Islands. This is maintaining light to gentle breezes across the region. Wave heights are 3 to 5 ft in open waters and 1 to 3 ft in the Gulf of California. The pattern will change by Thu as a vigorous mid/upper level disturbance moves south along the coast of southern California, supporting 1011 mb low pressure and accompanying cold front into the mouth of Colorado River and northern Gulf of California. This will result in fresh to strong S to SW winds across the far northern Gulf of California by Thu night. This will be short- lived however as the disturbance pivots through the region. Looking ahead, a another disturbance will move into California with a slightly stronger cold front moving across Baja California Norte and the northern Gulf of California by late Sat into early Sun. This will bring another pulse of strong S to SW winds to the northern Gulf of California late Sat. The front will also be accompanied by longer period NW swell of 8 to 12 ft reaching Guadalupe Island and the northern portion of Baja California Norte by Sat night. The swell will decay as it moves south, but seas of 8 to 10 ft will cover the waters off Baja California through late Sun. Elsewhere off Mexico, gentle breezes and seas of 4 to 6 ft will persist through Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong northeast winds are expected during the overnight and early morning hours through most of the forecast period. These winds may reach around 30 kt tonight and each night through Thu night. Gulf of Panama: Expect fresh to strong N to NE winds at night through Thu night. Seas downstream of the Gulf, south of 07N, are forecast to reach 6 to 8 ft with these winds Wed through Fri. REMAINDER OF THE AREA... See above for information on a gale warning for tonight into early Wed. A weak cold front is expected to move into the northern waters north of 28N Thu then lift northward. A slightly stronger cold front will follow Thu night, and reach from Baja California Norte to 22N140W by late Sun. Strong winds will accompany the front north of 27N Fri and Sat. High pressure building in the wake of the front will support fresh to strong trade winds from 20N to 25N west of 135W Fri night through Sun. $$ Stripling