ZCZC MIATCDEP3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM CARLOS DISCUSSION NUMBER 27 NWS NATIONAL HURRICANE CENTER MIAMI FL EP032015 400 AM CDT WED JUN 17 2015 The satellite appearance of Carlos continues to rapidly deteriorate as the surface circulation separates further from the remaining less organized and shrinking deep convection. Moderate northerly shear and mid to upper-level dry, stable, air penetrating the cloud pattern from western Mexico has more than likely been the contributing factor in the sudden weakening trend. Small, compact, tropical cyclones such as Carlos are notorious for spinning down as quickly as they can rapidly intensify. The initial intensity is lowered to 55 kt for this advisory and this could be generous given that the Dvorak technique has been known to be imprecise with small tropical cyclones. The NHC forecast calls for rapid weakening through the period as the cyclone interacts with the mountainous terrain of western Mexico before moving back over water around the 24 hour period. The current forecast philosophy is that Carlos' circulation will have been severely disrupted by the time of its expected to move offshore and into the southern Gulf of California. Thus, regeneration is unlikely and dissipation should occur in 48 hours or less. The initial motion is estimated to be around 330/6 kt. The primary steering mechanism through the forecast period is the south-southeasterly low-level flow produced by high pressure to the east-northeast of the cyclone and a trough of low pressure extending southward from the Gulf of California. The official forecast, which is nudged to the right of the previous forecast, is based primarily on a blend of the Florida State Superensemble, the GFS, and the shallow layer Beta and Advection Model (BAMS). FORECAST POSITIONS AND MAX WINDS INIT 17/0900Z 19.0N 104.8W 55 KT 65 MPH 12H 17/1800Z 19.8N 105.2W 35 KT 40 MPH...INLAND 24H 18/0600Z 20.6N 105.7W 25 KT 30 MPH...POST-TROP/REMNT LOW 36H 18/1800Z 21.1N 106.3W 20 KT 25 MPH...POST-TROP/REMNT LOW 48H 19/0600Z...DISSIPATED $$ Forecaster Roberts NNNN