000 AXPZ20 KNHC 102203 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Jun 10 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 1800 UTC surface analysis and satellite imagery through 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The Monsoon Trough extends from 11N85W to low pressure near 14N95W 1008 mb to 11.5N103W to 07N111W to 07N117W. The ITCZ axis extends from 07N117W to 07N125W to 08N130W. It resumes at 09N133W to beyond 07N140W. Scattered moderate to strong convection is observed within 180 nm south of the axis between 92W and 95W. Scattered moderate to isolated strong convection is seen within 120 nm south of the axis between 86W and 92W, within 60 nm north of the axis between 91W and 92W, and south of the axis within 30 nm of 10N93W. Scattered moderate convection is within 180 nm south of the axis between 100W and 107W, within 120 nm north and south of the axis between 95W and 98W, and also within 60 nm north of the axis between 107W and 110W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A northwest to southeast oriented ridge extends across the waters just west of the offshore zones. The gradient between the ridge and lower pressure near and over the Baja California peninsula will tighten this evening. This will develop fresh to strong northwest winds within about 60 nm west of the peninsula with seas building to 8 ft. The gradient will relax some early on Sunday allowing for these winds to diminish to the fresh category. Stronger high pressure will build southeastward over the waters west of the offshore zones by early on Monday leading again to a tightening of the pressure gradient over the same general area with strong northwest to north winds developing along with seas building to 8 to 9 ft. By early Monday afternoon, the gradient relaxes allowing for the strong northwest to north winds to diminish to the fresh category, however, a northwest swell propagating through the waters north of 27N between Baja California Norte and 122W will keep seas in the 8 to 9 ft range there and into middle of the upcoming week. Light to gentle winds prevail elsewhere across the offshore waters of Mexico. Seas are in the 5 to 6 ft range elsewhere off the coast of Baja California, 1 to 2 ft over the Gulf of California, and 4 to 5 ft offshore the remainder of Mexico. Gulf of California: Gentle to moderate southerly flow north of 29N will continue through the remainder of this afternoon, then become strong southwest to west winds beginning early tonight as the pressure gradient tightens between the thermal trough along the Gulf, and high pressure west of the Baja California peninsula that noses eastward towards the peninsula. These winds will then diminish to moderate to fresh category on Sunday afternoon as the gradient weakens some. The strong southwest to west winds will develop again on Sunday evening into Monday morning, and diminish early Monday afternoon. Seas are forecast to build to about 5 ft with the strong winds. Light and variable winds are expected south of 30N through Tuesday night. Broad low pressure situated south of the Gulf of Tehuantepec region and to the south of far southeastern Mexico will slowly track west-northwestward through early next week. Associated convection as described above under the ITCZ/MONSOON TROUGH section will remain quite active over and near the same waters where it is presently located. This activity is likely to contain strong gusty winds and rough seas. The most eastern edge of the convective activity has already spread inland some distances inland the coasts of southeastern Mexico, Guatemala, El Salvador and Nicaragua as of this afternoon. Moisture guidance from the NWP models indicate that this activity will persist for a few days, with the possibility of locally heavy rainfall over the aforementioned countries. In addition, there is some potential for the broad area of low pressure to acquire gradual development during the next few days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate westerly winds and 4 to 6 ft seas are expected north of 07N...and moderate southerly winds with 5 to 7 ft seas forecast south of 07N through Wednesday night. REMAINDER OF THE AREA... A 1021 mb surface high center is quasi-stationary near 24N121W with a ridge extending southeastward to near 20N115W. Generally, weak high pressure covers the area, with the exception of stronger high pressure building eastward over the northwest waters behind a weakening cold front that extends from a 1016 mb low pressure center near 31N120W southwestward to 27N130W where it becomes stationary to southwest of the area at 25N140W. An inverted surface trough is along a position from near 06N134W to 13N130W, moving west near 13 kt. Gentle to locally moderate northeast to east winds are present to the south of the ridge to along 10N, with the gentle winds confined near the high center. Moderate to locally fresh northeast winds are north of the frontal boundary. The frontal boundary will gradually weaken through tonight, and dissipate on Sunday as stronger high pressure builds southeastward over much of the area into early next week. The resultant tighter gradient between the high pressure and lower pressure in the vicinity of the tropics will bring fresh northeast to east winds throughout the remainder of area early next week, with seas building to 5 to 7 ft, except for slighter higher seas possible from about 10N to 15N west of 130W where the gradient there is expected to be tighter between the inverted surface trough and the high pressure. $$ Aguirre