ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM CARLOS DISCUSSION NUMBER 9 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032015 400 PM CDT FRI JUN 12 2015 Carlos looks a little better organized this afternoon with the center now fully embedded within a more symmetric and deeper central dense overcast. Microwave images show some evidence of inner core features, but they remain fragmented. Since Dvorak estimates are unchanged, the initial intensity will remain 50 kt, but this could be a bit conservative based on recent trends. The storm continues to be stationary within an area of light steering between a mid-level trough over the western Gulf of Mexico and a ridge over northwestern Mexico. The ridge is forecast to build over central Mexico on Sunday, which should then cause Carlos to move toward the west-northwest, nearly parallel to the coast of Mexico, into early next week at an increasing forward speed. A trough over the southwestern United States should move into northwestern Mexico, which could cause the storm to take a turn toward the northwest by Tuesday. Model guidance remains in relatively good agreement on this scenario, and the latest NHC forecast is close to the previous one. The intensity forecast continues to be challenging. During the next day or so, northeasterly shear is forecast to persist, so only a slight intensification of Carlos is anticipated. Thereafter, although the shear is expected to become light, a combination of warm upper-level temperatures, drier air aloft, and possible land interaction could help keep Carlos from strengthening significantly. By day 5, cooler waters and a more stable atmosphere should help to weaken Carlos. Although most of the intensity guidance no longer calls for Carlos to become a hurricane, this guidance has had a noted low bias this season, and the GFS still shows quite a bit of intensificaton. Thus, I am inclined to stay at the upper edge of the guidance, and near the previous NHC forecast. FORECAST POSITIONS AND MAX WINDS INIT 12/2100Z 14.7N 100.6W 50 KT 60 MPH 12H 13/0600Z 14.9N 100.6W 55 KT 65 MPH 24H 13/1800Z 15.2N 100.9W 55 KT 65 MPH 36H 14/0600Z 15.6N 101.6W 60 KT 70 MPH 48H 14/1800Z 16.1N 102.6W 65 KT 75 MPH 72H 15/1800Z 17.3N 104.6W 70 KT 80 MPH 96H 16/1800Z 19.5N 106.4W 60 KT 70 MPH 120H 17/1800Z 22.0N 107.8W 45 KT 50 MPH $$ Forecaster Blake NNNN