000 AXPZ20 KNHC 221522 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1522 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Tropical Storm Otto is stationary in the southwest Caribbean Sea near 10.4N 79.3W at 22/1500 UTC or about 225 nm east of Limon, Costa Rica, or about 285 nm east-southeast of Bluefields, Nicaragua. Estimated minimum central pressure is 986 mb. Maximum sustained wind speed is 60 kt with gusts to 75 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, then emerging offshore into the northeast Pacific Ocean as a remnant low. Interpolation of the official NHC forecast between days 3 and 5 still results in the possibility of tropical storm conditions in zone PMZ113 for Thursday night into Friday. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMAT1/WTNT21 KNHC for more details. Gulf of Tehuantepec gale warning: Northerly winds are pulsing from strong to near gale force with seas 8 to 11 ft early this morning, due to a locally tight pressure gradient. Winds are forecast to increase to minimal gale force Wednesday night as the gradient tightens due to strengthening high pressure ridging over eastern Mexico, with seas also building to 12 to 13 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 weakening tropical cyclone Otto to the south. 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 06N91W. The intertropical convergence zone axis extends from 06N91W to 05N100W to 10N124W to 1010 mb low pressure near 10.5N136W to 07N140W. Scattered moderate and isolated strong convection is from 07N to 14N between 125W and 132W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening cold front has moved into northwest Mexico with northerly flow 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 northwest in the Gulf of California north of 25N late Wednesday through Friday, with seas reaching 7 ft in the far northern Gulf. These winds are expected to seep through northern passages on the peninsula into the waters west of the peninsula Thursday and Thursday night. Winds will then diminish thereafter as the pressure gradient weakens. Otherwise, moderate to fresh northerly flow 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 send fresh northerly swells into the waters building seas up to 7 to 10 ft Wednesday night, with seas building to 8 to 12 ft Thursday into Friday as a new set of northwest swell arrives. That swell will decay slightly Friday night into Saturday. A new cold front will approach from the northwest Saturday night and winds in the northern Gulf of California will increase to fresh to strong out of the southwest- west Saturday night. Seas will build once again this upcoming weekend with new northwest swell associated with the front arriving. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... In the Gulf of Papagayo, fresh to strong northeast gap winds will manage to build seas to 7 to 9 ft this morning will diminish later today through tonight with seas subsiding. See the special features section above for potential impacts from tropical cyclone Otto later in the forecast period. Mariners planning to transit through the Panama Canal are also urged to monitor tropical cyclone Otto in the southwest Caribbean. Elsewhere, gentle to locally moderate offshore winds and combined seas of 3 to 6 ft prevail north of the monsoon trough, while moderate to fresh southwest flow and combined seas of 3 to 5 ft prevail south 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, with a 1010 mb low centered near 10.5N136W. The combination of these features is resulting in fresh to strong trades from roughly 10N to 20N, where northeast wind waves are mixing with long period northwest 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. $$ CHRISTENSEN