000 AXPZ20 KNHC 090245 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 033 UTC Sat Feb 9 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 0000 UTC surface analysis and satellite imagery through 0230 UTC. ...SPECIAL FEATURE... Gulf of Tehuantepec gale force gap wind event: A cold front is moving S into the Bay of Campeche. High pressure building south along the Sierra Madre Oriental mountains of Mexico in the wake of the cold front has tightened the pressure gradient across the Isthmus of Tehuantepec. Minimum gale force winds are expected to become strong gale force winds Sat night and Sun, then high pressure will start to weaken. This will loosen the pressure gradient across Tehuantepec, which will allow winds across Tehuantepec to diminish below gale force around midday Sunday, then diminish further to 20 kt or less Mon. Seas resulting from this gap wind event will peak near 17 ft Sat. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from low pres 1006 mb near 09N75W to 06N81W to 03N89W. The ITCZ continues from 03N89W to 02N104W to 05N119W to beyond 06N140W. Scattered moderate convection is noted from 06N to 08N between 121W and 123W, from 05N to 07N between 127W and 129W and from 04N to 08N W of 138W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge extends from 32N133W SE to the Revillagigedo Islands. The pressure gradient between this ridge and low pres over interior Mexico will maintain moderate NW to N winds along the coast of Baja California through Mon night. High pressure over the Great Basin region of the United States will maintain strong NW winds across the Gulf of California today. The area of high pressure across the Great Basin region will weaken and shift eastward, allowing winds to diminish across the Gulf of California this evening. Elsewhere light to gentle breezes and seas in the 4 to 6 ft range will prevail between the Gulf of Tehuantepec and Cabo Corrientes through the forecast period. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: High pres building SE from the eastern United States will tighten the pressure gradient over the Caribbean. This will generate strong gap winds across the Gulf of Papagayo, which will pulse to near gale force during the overnight hours tonight through Sun night. The ridge of high pressure will weaken and shift E early next week, which will help to diminish winds across the Papagayo region. Highest seas will build to near 11 ft during the time of peak winds. The area of 8 ft seas propagating SW from the Gulf of Papagayo will merge with the area of seas propagating downstream from the Gulf of Tehuantepec by Sat afternoon and create an area of 8 ft seas generally located from 02N to 16N between 85W and 110W. Long period SW and NW swell will also contribute to combined seas in this area. Gulf of Panama: A similar gap wind scenario can be expected across the Gulf of Panama, with strong winds pulsing to near gale force during the overnight hours this weekend. Winds will diminish early next week. Seas will build to near 11 ft downstream from the Gulf of Panama over the weekend. Elsewhere, gentle to moderate breezes will persist through Sun. REMAINDER OF THE AREA... The pressure gradient between a ridge of high pressure aligned from E to W along 29N, and lower pressure in the vicinity of the ITCZ is maintaining an area of fresh to strong trades north of the ITCZ to near 20N and west of 120W. Fresh to strong SE to E winds are also expected to develop N of 21N and W of 137W by dawn on Sat due to a tightening pressure gradient between the high pressure ridge and a deepening low pressure center currently located NNE of Hawaii near 26N152W. The surface low NNE of Hawaii will track E, then NE towards the forecast waters this weekend, tightening the pressure gradient over the waters N of 20N and west of 130W. This will increase winds to near gale force over this area Sat morning. Enhanced winds will linger over this area until Mon. The fetch of winds over this area will help seas build to between 14 and 16 ft near 30N140W Sat through Mon. $$ CAM