000 WTNT45 KNHC 182048 TCDAT5 Hurricane Maria Discussion Number 10 NWS National Hurricane Center Miami FL AL152017 500 PM AST Mon Sep 18 2017 Maria is developing the dreaded pinhole eye. The last reports from an Air Force Reserve Hurricane Hunter aircraft and radar data from Martinique indicated an eye with a diameter of about 8-10 n mi, and this featured has recently become better defined in visible and infrared satellite imagery. The aircraft data supported an intensity of 105-110 kt back at 18Z, and all indications are that rapid intensification is continuing. Thus, the initial intensity is increased to 115 kt. Another Hurricane Hunter aircraft is schedule to arrive in Maria about 2330Z, and it is distinctly possible that it will find a higher intensity than 115 kt. After an excursion to the left overnight, Maria has resumed a motion of 290-295 degrees at about 8 kt, and the short-term motion may be even farther to the right. A weak subtropical ridge to the north of the hurricane should steer it generally west-northwestward for the next three days, with the center crossing the Leeward Islands near Dominica during the next few hours. This is expected to be followed by a track across the northeastern Caribbean to near the Virgin Islands, then followed by a passage over or near Puerto Rico around the 48 h point. Once north of Puerto Rico, the hurricane should gradually turn toward the northwest and north-northwest as it approaches a weakness in the ridge. The track guidance is tightly clustered through 120 h, and the new forecast track is an update of the previous forecast that lies a little to the south of the various consensus models. Atmospheric and oceanic conditions appear favorable for additional rapid strengthening for the next 24 h and possibly longer. The intensity forecast, which is at or above the upper edge of the guidance, now calls for Maria to reach a peak intensity of 135 kt in about 24 h, and it is possible that the hurricane could reach category 5 status. Later in the forecast period, land interaction and less favorable upper-level winds are expected to cause some weakening. On top of these general trends, there is also the possibility that eyewall replacement cycles could occur that would affect the intensity. However, Maria is likely to remain an extremely dangerous major hurricane through the forecast period. It should be noted that the despite the great intensity of Maria, the hurricane force winds are currently confined to a small area near the eye. The radii forecast assumes that the 64-kt radii will not expand significantly during the next 36 h. However, if an eyewall replacement cycle occurs, the hurricane-force winds could expand to an area larger than forecast. If radar data from the eastern Caribbean is regularly available, Tropical Cyclone Updates may be issued this evening. KEY MESSAGES: 1. Maria will affect portions of the Leeward Islands and the British and U.S. Virgin Islands as an extremely dangerous major hurricane during the next couple of days, and hurricane warnings are in effect for many of these islands. 2. Maria is likely to affect Puerto Rico as an extremely dangerous major hurricane, and a hurricane warning has been issued for that island. 3. The potential for a life-threatening storm surge, accompanied by large and destructive waves, has increased for the Leeward Islands, the Virgin Islands, and Puerto Rico. 4. Life-threatening flash floods and mudslides from heavy rainfall are expected across the Leeward Islands, including Puerto Rico and the U.S. and British Virgin Islands. FORECAST POSITIONS AND MAX WINDS INIT 18/2100Z 15.1N 60.7W 115 KT 130 MPH 12H 19/0600Z 15.7N 61.9W 125 KT 145 MPH 24H 19/1800Z 16.5N 63.3W 135 KT 155 MPH 36H 20/0600Z 17.3N 64.7W 135 KT 155 MPH 48H 20/1800Z 18.2N 66.2W 130 KT 150 MPH...OVER PUERTO RICO 72H 21/1800Z 20.0N 69.0W 125 KT 145 MPH...OVER WATER 96H 22/1800Z 22.0N 71.5W 120 KT 140 MPH 120H 23/1800Z 25.0N 73.0W 105 KT 120 MPH $$ Forecaster Beven