000 AXPZ20 KNHC 051004 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 750 UTC Sun Mar 5 2017 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... Strong high pressure northeast of the region will maintain 30-35 kt north to northeast gap winds along a narrow swath across the Gulf of Tehuantepec until around dawn this morning. A broader swath of 20-30 kt north to northeast winds cover the remainder of the gulf to near 13N between 94W and 97W. Seas of 10-13 ft are confined within the area of gale force winds while seas of 8-11 ft are present within the area of 20-30 kt winds. The winds will diminish below gale force this morning as high pressure ridging extending from the Gulf of Mexico southwest to eastern Mexico shifts eastward and the tight pressure gradient over southeastern Mexico and the Isthmus of Tehuantepec slackens. By Monday morning, residual swell from this event will be combining with east swell emanating from the Gulf of Papagayo as well as SW swell coming from the Southern Hemisphere in a area spreading from near 05N to 10N between 91W and 109W. This area of seas will subside to less than 8 ft by Monday evening. A pulse of strong northerly flow will push through the Gulf of Tehuantepec on Monday with seas of 8-10 ft. This next round of gap winds will then diminish on Monday afternoon as seas fall to below 8 ft. See the latest NWS High Seas Forecast under AWIPS/WMO headers MIAHSFEP2/FZPN03 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ axis extends from 03N93W to 02N109W to 04N117W. A surface trough analyzed from near 02N120W to 12N121W interrupts the ITCZ. The ITCZ resumes from 03N123W to 02N129W to 03N140W. Scattered moderate and isolated strong convection is seen within 60 nm of a line from 10N111W to 13N120W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A tight pressure gradient associated with strong high pressure that extends from southeast U.S. to the Gulf of Mexico and to eastern Mexico is currently generating gale force north to northeast winds over portions of the Gulf of Tehuantepec. Please see the special features section for more details. High pressure ridging across the northern and central waters supports light to gentle northwest winds offshore west of Baja California and gentle to moderate winds for the Mexican waters north of 16N. Seas of 4-6 ft are present in both of these areas. A cold front will enter the northwest portion of the discussion area this afternoon, then weaken as it passes across the northeast waters this evening into Monday. The front will be accompanied by moderate to fresh north to northeast winds. The leading edge of long period northwest swell associated with the front will follow the front and enter the far northern portions of the area north of 29N and west by this evening. This set of northwest swell is forecast to move into the offshore waters of Baja California Norte Monday night and Tuesday. Seas will build to 10 ft in zone PMZ011. By Tuesday, strong northwest winds will develop over the Gulf of California, with seas building to 8 ft. Another Tehuantepec wind event is progged to begin around midday on Wednesday as strong high pressure expands southwest over the Gulf of Mexico and eastern Mexico in the wake of another cold front crossing the Gulf of Mexico. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... High pressure north and east of the region will continue to funnel fresh to strong northeast to east winds into the Gulf of Papagayo and surrounding waters through the forecast period. On Sunday during the late night and early morning hours the areal coverage of strong winds will reach from 07N to 13N as far west as 93W. Seas will build to 8-10 ft within this area as swell propagates westward and merges with large swell propagating from the Gulf of Tehuantepec. Over the Gulf of Panama...north to northeast fresh to strong winds through the gulf tonight will subside this morning. Seas will subside to less than 8 ft this evening. Elsewhere...light to gentle breezes and seas of 4-6 ft will prevail through early next week. REMAINDER OF THE AREA... High pressure ridging over the northern and central waters has weakened. This has reduced the pressure gradient over the western waters and allowed winds in this area to fall to moderate speeds. Seas in this have diminished below 8 ft. A cold front will begin crossing the northern waters this afternoon. The leading edge of long period northwest swell will follow the front into the far northern portions of the area north of 29N and west by this evening. This set of northwest swell is forecast to encompass all of the waters north of 22N by Monday evening. Seas of 8-10 ft are expected at thatm time, highest near 30N120W. $$ cam