677 AXNT20 KNHC 050005 TWDAT Tropical Weather Discussion NWS National Hurricane Center Miami FL 805 PM EDT Tue Sep 4 2018 Tropical Weather Discussion for North America, Central America Gulf of Mexico, Caribbean Sea, northern sections of South America, and Atlantic Ocean to the African coast from the Equator to 32N. The following information is based on satellite imagery, weather observations, radar and meteorological analysis. Based on 1800 UTC surface analysis and satellite imagery through 2345 UTC. ...SPECIAL FEATURES... Tropical Storm Gordon is centered near 29.7N 87.9W at 05/0000 UTC, or about 65 nm southeast of Biloxi, Mississippi or 60 nm south of Mobile, Alabama moving NW or 315 degrees at 13 kt. Estimated minimum central pressure is 999 mb. The maximum sustained winds are 60 kt with gusts to 75 kt. Latest satellite imagery and NWS radar imagery shows scattered moderate isolated strong convection within 150 nm of the center in the NE quadrant and within 90 nm of the center in the SE quadrant. Similar type convection is to the southeast of Gordon over the east gulf waters from 25N to 28N between 84W and 87W. Scattered moderate to isolated strong convection is from 25N to 27N between 87W and 89W, and over much of the Florida panhandle extending eastward across northern Florida to near 82W. Gordon is forecast to make landfall along the north-central Gulf of Mexico coast this evening. Public Advisories on Gordon are issued under the WMO/AWIPS headers WTNT32 KNHC/MIATCPAT2. Forecast advisories on Gordon are issued under WMO/AWIPS headers WTNT22 KNHC/MIATCMAT2. Hurricane Florence is centered near 20.3N 43.2W at 04/2100 UTC, or about 1134 nm E of the northern Leeward Islands moving WNW at 10 knots. The estimated minimum central pressure is 984 mb. The maximum sustained winds are 75 kt with gusts to 90 kt. The overall cloud pattern of Florence has become very symmetrical during the day and evening. Latest satellite imagery shows what appears to be a developing eye feature. The imagery shows scattered to numerous strong convection within 90 nm of the center in the NE semicircle, and within 60 nm of the center in the SW semicircle. Scattered moderate convection is from 20N to 21N between 41W and 43W. Latest NHC forecast has Florence continuing on a WNW motion through Wed night before it takes a northward turn on Thu. Florence is forecast to possibly strengthen tonight, then begin to weaken on Wed and through the end of the week. Public Advisories on Florence are issued under WMO/AWIPS headers WTNT31 KNHC/MIATCPAT1. Forecast Advisories are issued under WMO/AWIPS headers WTNT21 KNHC/MIATCMAT1. A strong tropical wave has its axis extending from 04N26W to 13N25W and to near 19N23W, with a 1007 mb low on the axis near 11N25W. This system depicts a broad area of low pressure with disorganized cloudiness. Deep convection, for the time being, is rather limited. Scattered moderate convection is within 30 nm of a line from 13N24W to 12.5N28W, within 30 nm of another line from 08N27W to 07N30W and within 30 nm of 14N24W. This system has a medium chance of becoming a tropical cyclone during the next 48 hours. Refer to the latest NHC Tropical Weather Outlook under AWIPS/WMO headers MIATWOAT/ABNT20 KNHC for more information. ...TROPICAL WAVES... A Caribbean Sea tropical wave has its axis along 77W/78W south of 21N to near 10.5N. The wave is moving under an area of upper level cyclonic wind flow, with an elongated NE to SW oriented trough. Scattered moderate isolated strong convection is increasing over and along the eastern coast of Cuba. Isolated moderate convection is from 15N to 18N between the wave and 80W. Scattered showers and isolated thunderstorms are over and near the Windward Passage. The northern portion of an eastern Pacific tropical waves reaches along 95W northward to the far southwest Gulf of Mexico to near 22N. It is moving westward at 15 kt. Scattered moderate convection is within 60 nm north of the wave from 21N to 22.5N between 94W and 95W. ...MONSOON TROUGH/ITCZ... The monsoon trough axis through the coastal sections of Senegal near 15N17W to the 1007 mb low associated with the broad area of low pressure described above under Special Features, and continues to 09N31W to 10N43W. The ITCZ axis extends from 10N43W to 08N50W to 09N59W. Scattered strong convection is just inland Africa from 13N to 15N between 14W and 17W. ...DISCUSSION... GULF OF MEXICO... Please see the SPECIAL FEATURES section above for details on Tropical Storm Gordon. An upper level trough is to the west of Gordon, from southeastern Louisiana to the Yucatan Peninsula of Mexico. Upper level cyclonic wind flow is inland in Mexico, from 25N southward between 96W and 106W. Aside from convection associated with Tropical Storm Gordon, scattered moderate convection is noted over much of the western half of the gulf waters from 22N to 28N between 91W and 97W. Isolated showers and thunderstorms are elsewhere over the remainder of the gulf. CARIBBEAN SEA... An upper level trough passes through the Atlantic Ocean, just to the north of Hispaniola, along a NE-to-SW line, toward Jamaica and eastern Honduras/NE Nicaragua. Isolated moderate rainshowers cover the Caribbean Sea from 13N northward from 70W westward. The easternmost part of the monsoon trough is along 08N/10N from 74W in Colombia beyond western Panama and southern Costa Rica. Widely scattered moderate to isolated strong rainshowers are from 11N southward from 75W westward. The tropical wave along 77W/78W will move across the rest of the central Caribbean through early Wed, then across the western Caribbean later on Wed and through Fri. A relatively weak surface ridge, that is to the north of the region, will maintain moderate to fresh trade winds mostly everywhere, through Saturday. ATLANTIC OCEAN... Please see the SPECIAL FEATURES section above for details on Hurricane Florence and on a new area of broad low pressure over the far eastern Atlantic with a medium chance of tropical cyclone formation. Upper level cyclonic wind flow covers the Atlantic Ocean from 20N northward from 46W westward. Widely scattered moderate to isolated strong rainshowers are from 30N northward between 55W and 61W. Isolated moderate rainshowers are elsewhere in the area of upper level cyclonic wind flow. A weak pressure pattern will maintain gentle to moderate easterly winds across the area through Saturday. Easterly swell from Hurricane Florence will move into the open waters east of the Bahamas starting late Wednesday. For additional information please visit http://www.hurricanes.gov/marine $$ MT/Aguirre