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| #880246 (Received by flhurricane at: 3:42 AM 22.Nov.2016) TCDAT1 TROPICAL STORM OTTO DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL162016 400 AM EST TUE NOV 22 2016 Deep convection has continued to burst near the low-level center of Otto tonight. A pair of ASCAT passes between 02Z and 03Z showed peak winds of around 45 kt, which support maintaining the intensity at 50 kt for this advisory. This intensity estimate is also represents a blend of the 06Z subjective Dvorak estimates of 45 kt and the latest UW-CIMSS ADT estimate of 53 kt. An Air Force Reserve Hurricane Hunter aircraft is scheduled to investigate Otto later this morning. Otto`s outflow pattern remains restricted south and southeast of the center, consistent with about 20 kt of shear analyzed over the cyclone by the SHIPS model analysis and UW-CIMSS. This shear is forecast to persist for the next 24 h or so and then abate somewhat by 36 hours. Given this, some gradual strengthening is expected while Otto moves over waters of around 29C, and the NHC forecast shows Otto becoming a hurricane in 24 to 36 h. The official forecast through 48 h is a little above the intensity consensus and close to the latest FSU Superensemble and the NOAA HFIP consensus aid HCCA. After that time, land interaction should result in weakening and much of the guidance continues to suggest that Otto will weaken to a remnant low after it emerges into the eastern Pacific, and this is still reflected in the official forecast. It is worth noting, however, that the ECMWF maintains Otto as a stronger cyclone over the Pacific through day 5. After drifting south-southeastward overnight, Otto is estimated to be stationary. Little net motion is expected today while the tropical cyclone is caught in a region of weak steering currents. By 24 hours, a mid-level ridge will begin to build north of Otto, which should impart a west-northwestward motion and then a westward turn at a slightly faster forward speed by 48 h as the ridge amplifies. This synoptic pattern should steer Otto toward the coast of Central America in 48 to 72 hours. After that time, a further westward acceleration is expected as the mid-level ridge builds westward. The new NHC track forecast is faster than the previous one at 48 hours and beyond and has been adjusted southward at days 3-5. The new official forecast lies between HCCA and the FSU Superensemble through 48 hours and is close to a blend of the GFS and ECMWF after that time. FORECAST POSITIONS AND MAX WINDS INIT 22/0900Z 10.7N 79.0W 50 KT 60 MPH 12H 22/1800Z 10.7N 79.1W 55 KT 65 MPH 24H 23/0600Z 10.9N 79.8W 60 KT 70 MPH 36H 23/1800Z 11.2N 80.8W 65 KT 75 MPH 48H 24/0600Z 11.2N 82.0W 70 KT 80 MPH 72H 25/0600Z 11.0N 85.2W 50 KT 60 MPH...INLAND 96H 26/0600Z 10.5N 89.0W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 27/0600Z 10.0N 93.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Brennan |
