000 WTNT44 KNHC 292037 TCDAT4 HURRICANE MATTHEW DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142016 500 PM AST THU SEP 29 2016 After the low-level center became nearly exposed this morning, deep convection has redeveloped over the center. The overall cloud pattern of Matthew has become better organized during the day, with some banding features over the eastern and northern portions of the circulation. Thanks to some timely observations from the Air Force Hurricane Hunters, Matthew was upgraded to a hurricane at 18Z. This was based on several believable SFMR-observed surface wind measurements from the aircraft. Matthew is forecast to remain in an environment of 15 to 20 kt of shear into Friday, with some relaxation of the shear expected by late Friday. The official intensity forecast is a little higher than the previous one, and is a little above the model consensus but close to the latest HWRF model prediction. Matthew has not slowed down yet, with the initial motion remaining westward at 15 kt. A mid-tropospheric ridge to the north of the hurricane should maintain a westward to slightly south of westward motion for the next 48 hours or so. Then, Matthew is likely to turn to the right as it nears the western periphery of the ridge, and head generally northward to the southwest and west of the high and east of a trough over the Gulf of Mexico late in the forecast period. One should not focus on the details of the track at 72 to 120 hours due to the inherent forecast uncertainties. It should be noted that the NOAA G-IV aircraft is currently doing a synoptic surveillance mission to provide data in the environment of Matthew for initializing the numerical models. It is hoped that these additional data will improve the accuracy of tonight's model runs. The unusually far south track of Matthew has necessitated the issuance of a tropical storm watch for a portion of the coast of Colombia. FORECAST POSITIONS AND MAX WINDS INIT 29/2100Z 14.1N 67.8W 65 KT 75 MPH 12H 30/0600Z 14.0N 69.6W 70 KT 80 MPH 24H 30/1800Z 13.8N 71.5W 75 KT 85 MPH 36H 01/0600Z 13.7N 72.7W 80 KT 90 MPH 48H 01/1800Z 13.7N 73.7W 85 KT 100 MPH 72H 02/1800Z 15.7N 75.1W 90 KT 105 MPH 96H 03/1800Z 18.6N 75.5W 90 KT 105 MPH 120H 04/1800Z 22.5N 75.5W 85 KT 100 MPH $$ Forecaster Pasch/Brown