000 WTNT44 KNHC 020859 TCDAT4 HURRICANE MATTHEW DISCUSSION NUMBER 17 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142016 500 AM EDT SUN OCT 02 2016 The overall organization of the hurricane has changed little overnight, with the small eye remaining distinct in infrared satellite pictures. A very recent AMSR2 microwave overpass showed no indication of an eyewall replacement, but there was a notable dry slot between the inner core and the outer bands over the southern portion of the circulation. Although Dvorak data T-numbers decreased slightly at 0600 UTC, the objective and subjective CI numbers are about the same as before, so the initial intensity will remain 130 kt for this advisory. Another Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Matthew this morning, which should provide a better assessment of the hurricane's current strength and structure. Although some weakening is predicted during the next couple of days, Matthew is expected to remain a powerful hurricane when it approaches the islands of the Greater Antilles in a couple of days. The upper-level wind environment is expected to remain favorable over the Bahamas, and warm waters in that area should allow Matthew to maintain much of its intensity while it moves over that area later in the forecast period. Matthew has been moving slowly west-northwestward during the past few hours, but the longer-term motion estimate is northwest or 320 degrees at 4 kt. The forecast track reasoning remains unchanged from before. Matthew should move slowly northwestward today, and then turn northward tonight as a mid- to upper-level trough develops over the eastern Gulf of Mexico. This motion will take Matthew towards Jamaica, western Haiti, and eastern Cuba over the next couple of days. After that time, the global models bend Matthew back toward the north-northwest between the aforementioned trough and a developing ridge off the northeast United States coast. The dynamical models are in good agreement on this scenario through 72 hours, with increasing spread thereafter. The GFS, ECMWF, and UKMET are along the western side of the guidance at days 4 and 5, while the HWRF is along the eastern side. The latest NHC track is close to the model consensus through day 3, but is west of the consensus at 96 and 120 h, to be closer to the typically better performing global models. It is important to remind users that average NHC track forecast errors are around 175 miles at day 4 and 230 miles at day 5. Therefore, it is too soon to rule out possible hurricane impacts from Matthew in Florida. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 13.9N 74.1W 130 KT 150 MPH 12H 02/1800Z 14.6N 74.5W 125 KT 145 MPH 24H 03/0600Z 15.6N 74.7W 120 KT 140 MPH 36H 03/1800Z 17.1N 74.7W 115 KT 130 MPH 48H 04/0600Z 18.8N 74.5W 110 KT 125 MPH 72H 05/0600Z 22.6N 74.8W 105 KT 120 MPH 96H 06/0600Z 25.5N 75.5W 100 KT 115 MPH 120H 07/0600Z 28.0N 76.2W 95 KT 110 MPH $$ Forecaster Brown