000 AXPZ20 KNHC 190112 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0041 UTC Mon Aug 19 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 0000 UTC surface analysis and satellite imagery through 0030 UTC. ...SPECIAL FEATURES... A 1008 mb low pressure center is located about 150 nm SW of the Guatemala/Mexico border, near 12N92W. The center has been nearly stationary today, but is expected to resume a WNW track tonight, that will persist early this week. Moderate convection is located within about 210 nm of all quadrants. Locally heavy rainfall is occurring across portions of coastal El Salvador, Guatemala, and Chiapas. This low has a medium chance of tropical formation through Tuesday. The threat for heavy rainfall and potential flash flooding will be over Guatemala, Chiapas, and Oaxaca over the next couple of days. Fresh winds and seas of 5 to 7 feet are associated with this low this evening, and winds and seas should gradually increase as the low tracks parallel to the coast. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOEP/ABPZ20 KNHC for more information. A 1008 mb low pressure center has formed about 900 nm SW of the southern tip of Baja California, near 11N119W, moving west at 5 to 10 kt. Numerous moderate and scattered strong convection exists from 09N to 15N between 116W and 125W. Fresh winds are occurring 60 nm N semicircle and 210 nm S semicircle of this low. There is a moderate chance of tropical formation of this low that is forecast to move W or WNW around 10 kt over the next couple of days. Winds and seas may gradually increase in association with this low. ...TROPICAL WAVES... A tropical wave axis extends along 109W, moving west around 5 kt. Scattered moderate convection is located from 08N to 15N between 106W and 115W. A tropical wave is along 130W, moving W around 5 kt. Weak low pressure, around 1010 mb, is associated with this wave near 14N129W. A cluster of moderate convection is located with 60 nm all quadrants of this low center. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 08N76W to 10N86W to low pres near 12N92W to low pres near 11N119W to 15N130W. Scattered moderate convection is noted from 06N to 15N between 80W and 90W and from 07N to 12N between 96W and 106W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more details about the low pressure area south of Guatemala/Mexico border and approaching the Gulf of Tehuantepec. A weak high pressure ridge extends SE from the north-central Pacific into the Baja California offshore waters, bringing gentle to moderate NW winds to these waters. This ridge will slowly shift SE into the middle of the week, causing the pressure gradient to increase Monday through early Wednesday. This will support moderate to fresh NW winds offshore of Baja California Norte, becoming fresh to locally strong Tuesday afternoon and evening. A low pressure trough along the Baja California peninsula will support fresh S to SE winds over the northern Gulf this morning before tonight. This trough will redevelop again late Wed into Thu to again produce fresh southerly wind flow across the northern Gulf. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section for more details about the low pressure area SW of the Guatemala/Mexico border. Winds across the Papagayo region will remain offshore and pulse at times to fresh through the early part of the week. Southerly swell with seas of 5 to 7 ft offshore of Ecuador and the Galapagos Islands will subside tonight, with new long period SW swell arriving by mid-week. Otherwise, mainly moderate W to SW winds will prevail S of 10N, along with seas of 4 to 6 feet. REMAINDER OF THE AREA... Weak low pressure of 1010 mb has formed near 12N136W. Moderate convection is located with about 60 nm of the center in all quadrants, with the possibility of locally higher winds and seas in its vicinity. The low should move westward, west of 140W by Monday afternoon. A weak ridge extends SE from 1023 mb high pressure near 41N143W. Scatterometer data showed gentle to moderate trades outside of any deep convection, while altimeter data sampled 4-7 ft seas. A weak cold front or pre-frontal trough is forecast to breach SE of 30N140W by the end of the forecast period with a wind shift and building seas to 7 ft behind it. This will force the ridge ahead of it to shift ESE, and gradually tighten the pressure gradient to the south across the tradewind belt. E to NE tradewinds will freshen W of 120W Tue through the end of the week due to this pattern shift. $$ KONARIK