Pacific Discussion

  • NHC East Pacific Tropical Weather Discussion
    by (nhcwebmaster) on August 17, 2019 at 9:03 AM

    000 AXPZ20 KNHC 170903 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Aug 17 2019 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... Low pressure at 1012 mb located a couple of hundred miles S of the coast of Guatemala is supporting numerous showers and scattered thunderstorms within 150 nm in the NW semicircle, along with gusty winds and heavy downpours across Central America from Panama to Guatemala, and spreading NW into SE Mexico. This low has a medium chance for tropical cyclone formation during the next couple of days as it moves W-NW around 10 kt while paralleling the coastlines, and moisture associated with the low will continue to produce heavy rainfall and possible flash flooding. Winds and seas will also increase across the offshore waters areas from El Salvador to offshore of Mexico the next several days. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more information. ...TROPICAL WAVES... A tropical wave axis near 83W extends southward from near the Costa Rica/Panama border into the eastern Pacific, moving W at 10 to 15 kt. Limited deep convection is present near the wave on the eastern Pacific side. A tropical wave axis near 96W/97W extends southward from Oaxaca Mexico into the eastern Pacific, moving W at around 10 kt. Scattered moderate to strong convection was noted N of 06N between 93W and 98W. A tropical wave axis is near 106W, moving W at 5 to 10 kt. Scattered moderate convection is noted from 14N to 15N between 107W and 107W, with scattered moderate and isolated strong convection from 15N to 17N between 99W and 106W. A tropical wave axis is near 117W, moving W at 5 to 10 kt. Numerous moderate and scattered strong convection is noted from 08N to 12N between 115W and 124W. A tropical wave axis is near 128W, moving west at 5 to 10 kt. Scattered moderate and isolated strong convection is from 14N to 17N between 123W and 128W. Scattered moderate convection is from 08N to 10N between 128W and 130W. Low pressure may form in association with this wave during the weekend or early next week as it moves slowly westward. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N85W to low pressure near 12N90W to 13N106W to 11N120W to 09N130W to 08N140W. Scattered moderate and isolated strong convection is from 06N to 08N between 87W and 90W, from 06N to 12N between 109W and 114W, and also from 06N to 10N W of 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for more details about the area of low pressure and associated heavy rainfall. A broad high pressure ridge extends across the Baja California offshore waters, bringing gentle to moderate NW winds to the region. This ridge will generally remain in place through early next week. The pressure gradient between this ridge and low pressure over the western United States has led to stronger winds north of the area, and these winds have generated swell that will may propagate to northern parts of the waters offshore Baja California Norte for the first part of the weekend. Seas at times will build to around 7 ft. Low pressure trough extending down the Baja California peninsula will support locally strong S and SE winds over the northern Gulf through today, generating seas of around 6 ft. The pressure gradient along the Pacific coast of Baja California will tighten early next week, with NW winds increasing to moderate to fresh. For the remainder of waters offshore Mexico, generally gentle winds will prevail through today. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please read the Special Features section for more details about the area of low pressure and associated heavy rainfall. Winds in the Gulf of Papagayo will become offshore and pulse to fresh Sun night, then moderate thereafter. Southerly swell of 5 to 7 ft impacting the Ecuador/Galapagos offshore waters will decay through early next week. Otherwise, mainly moderate winds will prevail into early next week, along with seas of 4 to 6 feet. REMAINDER OF THE AREA... Moderate to fresh winds in the wake of a tropical wave now W of 140W support seas of 6 to 8 ft from 15N to 20N W of 136W. These seas will diminish during the next several hours as the wave moves away from the area. Across the remainder of the Pacific high seas area, moderate to fresh winds prevail in the NW corner, with moderate winds or less elsewhere. Winds will diminish for the second half of the weekend into early next week as the pressure gradient slackens. Northerly swell N of 27N will lead to seas of 8 to 9 ft to the W of 125W through early Sun before decaying. $$ Lewitsky