000 AXPZ20 KNHC 070953 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Oct 7 2020 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 0945 UTC. ...SPECIAL FEATURES... Tropical Storm Norbert is centered near 14.0N 107.1W or about 330 nm south-southwest of Manzanillo, Mexico at 0300 UTC drifting N at 1 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed has diminished to 35 kt with gusts to 45 kt. A 0316Z overnight ASCAT data revealed that Norbert had shifted a little to the southwest since 00Z last night. The same ASCAT pass indicated that the cyclonic circulation is rather small. Satellite imagery shows numerous moderate to isolated strong convection within 90 nm of the center in the NE quadrant and within 60 nm of the center in the SE quadrant. Scattered moderate to isolated strong convection is observed from 14N to 15N between 105W-106W and from 13N to 14N between 108W-109W. Norbert is forecast to meander or be nearly stationary over the next coupled of days, roughly near the outer boundary or just outside of the offshore waters of SW Mexico. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP4.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP4.shtml for more details. ...TROPICAL WAVES... A tropical wave has its axis along 86W north of 02N to across northwestern Panama and southwestern Nicaragua. It is moving westward at 10-15 kt. Scattered moderate to isolated strong convection is occurring from 06N northward to just west of northern Costa Rica and just west of the southwest section of Nicaragua. A tropical wave has its axis along 100W from 03N to 16N, moving westward near 10 kt. A narrow line of scattered moderate convection is noted behind the wave from 10N to 14N between 98W and 99W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Panama northwestward to southern Nicaragua and southeastern El Salvador, then it curves southwestward to low pressure of 1010 mb near 11N94W and to 10N98W where it breaks down. It resumes at 14N111W to 13N120W to low pressure of 1008 mb near 12N123W and to 12N137W. The ITCZ extends from 12N137W to beyond the area at 11N140W. Scattered moderate to isolated strong convection is seen within 120 nm north of the trough between 126W-127W and within 60 nm north of the trough between 121W-124W. Scattered moderate convection is within 180 nm south of the trough between 114W-117W and within 180 nm south of the trough between 118W-122W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see Special Features section for details on Tropical Storm Norbert. Seas of 8-10 ft will shift northwestward across the far outer offshore waters of SW Mexico to the west of Manzanillo through Thu. High pressure will become established over the offshore waters of Baja California through the rest of the week, with the associated gradient allowing for generally gentle to moderate northwest to north winds with seas of 5-7 ft. As it is normal for this time of the year, mainly light to gentle southerly winds are expected in the Gulf of California during the next several days. Strong north to northeast winds across the Gulf of Tehuantepec will gradually diminish through the rest of the week. Seas of 8-10 ft there will slowly subside through Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to locally fresh southwesterly winds are expected S of the monsoon trough with mainly light to gentle winds north of it. Seas generated by the recent gale-force gap winds in the Tehuantepec region will continue to propagate across the offshore waters of Guatemala and El Salvador through tonight. REMAINDER OF THE AREA... Please see Special Features section above for details on Tropical Storm Norbert. The Post-Tropical Cyclone Marie low with pressure of 1005 mb is centered near 23N136W. Satellite imagery currently depicts the former tropical cyclone as a large swirl of broken to overcast low and mid-level clouds from 19N to 27N and between 132W-140W. Scattered mainly-low top showers and patches of rain are possible underneath these clouds. The pressure gradient between the low and high pressure to its north is supporting a large wind field of strong to near gale-force winds in the northern semicircle along with wave heights in the 10-15 ft range. Gradual weakening is forecast during the next 48 hours as the remnant low moves over the remainder of the far western part of the area and crosses to west of 140W late Thu night into early Fri, at which time wave heights are expected to lower below 8 ft along and near 140W. Otherwise, gentle to moderate winds are occurring N of the monsoon while moderate to locally fresh winds prevail to the south of the monsoon trough. Seas greater than 8 ft generated by former tropical cyclone Marie cover most of the waters north of 10N and west of a line from 28N130W to 16N137W. Long-period southeast swell from the Southern Hemisphere has reached north to near 10N and between 100W-130W. This swell will continue to propagate northward to near 16N by late Thu. $$ Aguirre