000 AXPZ20 KNHC 222204 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2140 UTC Tue Nov 22 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Newly upgraded Hurricane Otto is drifting slowly W in the SW Caribbean Sea near 10.5N 79.6W at 22/2100 UTC or about 200 nm east of Limon, Costa Rica, or about 260 nm east-southeast of Bluefields, Nicaragua. Estimated minimum central pressure is 984 mb. Maximum sustained wind speed is 65 kt with gusts to 80 kt. Otto is forecast to move across Central America near or along the border of Costa Rica and Nicaragua by the end of the week as a minimal hurricane, but is now expected to emerge offshore into the northeast Pacific Ocean as a tropical storm. Tropical storm conditions remain possible in zones PMZ111...PMZ113 and PMZ115 for Thursday night through Friday night. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. Gulf of Tehuantepec gale warning: Winds have abated for he time being, but N winds will be increasing to minimal gale force Wednesday night as the gradient tightens due to strengthening high pressure ridging over eastern Mexico, with seas also building to 10 to 15 ft. Gales are then expected to persist through Saturday night, with the strongest winds, up to 40 kt, expected during the overnight and early morning hours Friday night into Saturday between the high pressure north of the area and the approaching tropical cyclone Otto to the east. Seas will build to up to 16 ft during the stronger winds. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 09N84W to 05N92W. The intertropical convergence zone axis continues from 05N92W to 10N126W to 09N132W to 11N136W to beyond 09N140W. Numerous moderate and isolated strong convection is present from 07N to 11N between 125W and 128W. Scattered moderate and isolated strong convection is observed elsewhere from 06N to 12N between 125W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening cold front has moved into NW Mexico with northerly flow continuing behind it in the Gulf of California, and west of the Baja California Peninsula. High pressure building in the wake of the front over the Rockies will allow winds to increase to fresh to strong out of the NW in the Gulf of California late Wednesday through Friday, with seas reaching 8 ft in the far northern Gulf as winds reach near gale strength. These winds are expected to seep through northern passages on the peninsula into the 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. Northwest swells of 6 to 9 ft will decay below 8 ft through tonight. Strengthening winds north of the area will send fresh N swell into the waters, resulting in seas building to 7 to 10 ft Wednesday night. Seas will build to 8 to 12 ft Thursday and Friday as a new set of NW swell arrive. The newest batch of swell will decay slightly Friday night into Saturday. A new 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 this upcoming weekend as new 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, fresh to strong NE gap winds will maintain seas at 9 ft this evening, then seas will subside. 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 tropical cyclone 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 north of 25N. Farther south, two surface troughs are embedded in the ITCZ near 125W and 139W. 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 will move east over the area north of 28N, eventually stalling and dissipating from 32N130W to 30N140W by late Friday. Another round of reinforcing northwest swell will accompany the front. High pressure will be reinforced behind this weakening boundary as well, with the fresh to strong trades expected to persist through the remainder of the week and into the upcoming weekend. Another, and stronger cold front is forecast to drop into the northern waters Friday night into Saturday. Northerly winds behind the front will increase to fresh to strong north of 29N with a new set of northwest-north swell arriving with the boundary. $$ cam