067 
 WTPZ41 KNHC 131435
 TCDEP1
 
 TROPICAL STORM KARINA DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP112014
 800 AM PDT WED AUG 13 2014
 
 Deep convection has continued to increase with cloud tops of -80C
 to -84C noted just west of low-level center. Satellite intensity
 estimates are a consensus T2.5/35 kt from TAFB, SAB, and UW-CIMSS
 ADT. An earlier ASCAT overpass also indicated surface winds near
 34 kt. Based on these data, the depression has been upgraded to
 Tropical Storm Karina.
 
 Karina is moving westward at 13 kt along the southwestern periphery
 of a strong deep-layer subtropical ridge anchored over the
 south-central and southwestern United States. The ridge is forecast
 by the global models to build westward to the north and northwest
 of the cyclone, which should keep Karina on a basic westward motion
 throughout the 5-day period. The model guidance envelope has
 shifted a little to the south with increasing spread, especially
 beyond 72 hours. This is mainly due to the significant southward
 shift by the ECMWF model, which shows a much weaker system being
 steered more southwestward by moderate northeasterly trade wind
 flow. The ECMWF model is considered to be an outlier at this time,
 and the official track forecast is just a little faster than the
 previous advisory and lies near the consensus model TCVE.
 
 Karina is experiencing northeasterly vertical wind shear of 12-14
 kt. Despite these modest shear conditions, the convective cloud
 pattern of Karina has continued to develop into a classic hooked
 band appearance, plus a small central dense overcast feature.
 Microwave satellite data also suggests that the inner core wind
 field has tightened somewhat up since the previous advisory. With
 the wind shear currently affecting the system forecast to slowly
 subside over the next 4 to 5 days while the cyclone is over 28-29C
 SSTs, steady intensification appears likely. This development
 scenario is consistent with the trend of all of the NHC model
 guidance, and the NHC official intensity forecast indicates this by
 making Karina a hurricane by 48 hours, which is higher than the ICON
 intensity consensus model and closer to the SHIPS model.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  13/1500Z 17.2N 111.0W   35 KT  40 MPH
  12H  14/0000Z 17.4N 112.8W   45 KT  50 MPH
  24H  14/1200Z 17.5N 115.3W   55 KT  65 MPH
  36H  15/0000Z 17.6N 117.6W   60 KT  70 MPH
  48H  15/1200Z 17.8N 120.0W   65 KT  75 MPH
  72H  16/1200Z 18.3N 124.1W   75 KT  85 MPH
  96H  17/1200Z 18.5N 128.0W   75 KT  85 MPH
 120H  18/1200Z 18.5N 131.1W   70 KT  80 MPH
 
 $$
 Forecaster Stewart