ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL STORM KARINA DISCUSSION NUMBER 48 NWS NATIONAL HURRICANE CENTER MIAMI FL EP112014 200 PM PDT SUN AUG 24 2014 Strong vertical shear being induced by an upper-level high centered northeast of Karina continues to weaken the tropical storm. Deep convection continues in association with the cyclone, though it is occurring only over the western semi-circle and it has decreased in areal extent. In fact, in the last few visible images, the low-level center is popping out from underneath the thinning cirrus overcast. A "bulls-eye" ASCAT-B hit at 1802Z indicated a peak surface wind between 40 and 45 kt, so the initial intensity is set at 45 kt. Strong vertical shear should continue to afflict Karina, as the outflow from major hurricane Marie will soon begin to reach the tropical storm. The combination of high vertical shear, marginally warm SSTs, and fairly dry air should lead to a gradual weakening of the tropical cyclone. Karina should become a remnant low in about two days. However, the strong shear and mediocre thermodynamics may lead to remnant low status earlier. The intensity forecast is based upon a blend of the SHIPS and LGEM statistical models, and is a bit lower than that from the previous advisory due to the weakened initial condition of the cyclone. The aforementioned ASCAT-B pass confirmed the rather small tropical-storm-force wind radii of Karina. A gradual reduction in the cyclone's size is anticipated as the cyclone winds down. Karina is being steered eastward at 8 kt around the large circulation of post-tropical cyclone Lowell to its north-northeast. The center of the system is now well known, due to the ASCAT-B pass and the visible appearance of the low-level center. The steering influence of Lowell will diminish by tomorrow as the distance between the systems increases, and Karina should respond by slowing down and turning gradually to the east-southeast. In about 36 hours, Karina's track will mainly be influenced by the approaching large and powerful Marie. Karina or its remnant low should be accelerated toward the east until it becomes absorbed within Marie between two and three days. The forecast track is based upon the TVCN multi-model track consensus technique and is slightly faster than that issued in the previous advisory. FORECAST POSITIONS AND MAX WINDS INIT 24/2100Z 17.8N 130.4W 45 KT 50 MPH 12H 25/0600Z 17.7N 129.1W 35 KT 40 MPH 24H 25/1800Z 17.5N 127.9W 30 KT 35 MPH 36H 26/0600Z 17.2N 127.2W 25 KT 30 MPH 48H 26/1800Z 16.5N 126.1W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 27/1800Z...DISSIPATED $$ Forecaster Landsea NNNN