000 AXPZ20 KNHC 230314 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 108 UTC Wed Nov 23 2016 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 0300 UTC. ...SPECIAL FEATURES... Hurricane Otto is moving slowly WNW at 03 kt in the SW Caribbean Sea near 10.7N 79.8W at 23/0300 UTC or about 195 nm east of Limon, Costa Rica, or about 250 nm ESE of Bluefields, Nicaragua. Estimated minimum central pressure is 988 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Otto is forecast to arrive over Central America near or along the border of Costa Rica and Nicaragua on Thursday afternoon as a minimal hurricane, but is now expected to emerge offshore into the northeast Pacific Ocean as a tropical storm on Friday. Tropical storm conditions remain possible in zones PMZ111...PMZ113 and PMZ115 Friday and Saturday. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. Gulf of Tehuantepec gale warning: Fresh to strong N winds will abate briefly on Wednesday afternoon, then increase to minimal gale force Wednesday night as the gradient tightens due to strengthening high pressure ridge over eastern Mexico. Gales are then expected to persist through Saturday night. The strongest winds, up to 40 kt, are expected during the overnight and early morning hours Friday night until Saturday morning as the gradient sets up between high pressure N of the area and Otto approaching from the east. Seas will build to up to 14 ft during the stronger winds. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 10N85W to 06N92W. The intertropical convergence zone axis continues from 06N92W to 10N114W to 11N126W to 10N133W to 11N138W to beyond 11N140W. Scattered moderate and isolated strong convection is observed within 120 nm either side of a line from 15N116W to 08N129W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure building in over the Rockies will cause winds to increase to fresh to strong out of the NW over the Gulf of California n of 25N late Wednesday through Friday. These winds are expected to seep through the northern passages of the peninsula into the Pacific waters W of the peninsula Thursday and Thursday night. Winds will then diminish thereafter as the pressure gradient weakens. Otherwise, moderate to fresh N winds will persist west of the peninsula across the open Pacific waters. NW swell W of Baja are decaying and seas W if Baja S of 25N will subside below 8 ft tonight. A new cold front approaching 30N140W will send fresh N swell into the waters, resulting in seas building to 7 to 10 ft on Thursday. Seas will build to 8 to 12 ft on Thursday night and Friday as the new set of NW swell arrive. The newest batch of swell will decay slightly Friday night into Saturday. Another cold front will approach from the NW Saturday night. Winds in the northern Gulf of California will increase to fresh to strong speeds out of the SW to W Saturday night. Seas will build once again over this weekend as the NW swell associated with the front arrive. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, the fresh to strong NE gap winds have abated to moderate to fresh speeds, allowing seas to subside below 8 ft. See the special features section above for potential impacts from Otto later in the forecast period. Mariners planning to transit through the Panama Canal are also urged to monitor Otto in the SW Caribbean. Elsewhere, gentle to locally moderate offshore winds and combined seas of 3 to 6 ft prevail N of the monsoon trough, while moderate to fresh SW flow and combined seas of 3 to 5 ft prevail S of the monsoon trough. Little change is forecast through the end of the week and into the upcoming weekend. REMAINDER OF THE AREA... Relatively strong high pressure ridging prevails across the waters N of 25N. Farther S, a surface trough is located just N of the ITCZ from 12N126W to 16N125W. The combination of these features is resulting in fresh to strong trades from roughly 10N to 20N, where NE wind waves are mixing with long period NW swell, producing combined seas of 7 to 11 ft. A weak cold front is still expected to move E over the area N of 28N. The front will eventually stall and dissipate from 32N130W to 30N140W by late Friday. Another round of reinforcing NW swell will accompany the front. High pressure will be reinforced behind this weakening boundary as well. Fresh to strong trades should persist through Sunday. Yet another cold front will make an incursion into the northern waters Friday night into Saturday. High pressure building in behind the front will enlarge the area of fresh to strong trades N of the ITCZ and bring fresh to strong NW winds to the waters W of Baja as far S as 24N Sunday night through Monday night. $$ cam