284 
 WTPZ44 KNHC 071433
 TCDEP4
 
 TROPICAL STORM NORBERT DISCUSSION NUMBER  21
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP142014
 800 AM PDT SUN SEP 07 2014
 
 Deep convection has been decreasing quickly during the last several
 hours, and only a small area of cold cloud tops remains to the
 south of the center.  Satellite intensity estimates are falling, and
 the initial wind speed is lowered to 50 kt using an average of the
 Dvorak CI-numbers from TAFB, SAB, and UW-CIMSS. The quick weakening
 of Norbert is due to the influence of cool waters of around 25 C and
 a dry stable air mass.  These factors will become even more
 unfavorable along the expected track of Norbert, and should cause
 the cyclone to degenerate to a remnant low in about 24 hours, or
 maybe even sooner. Once Norbert becomes a remnant low, the cyclone
 is expected to slowly spin down and then open into a trough in about
 4 days. The NHC intensity forecast is lower than the previous one,
 mainly due to the observed rate of weakening.
 
 Norbert is still moving west-northwestward, but it is expected to
 turn toward the northwest and then north during the next day or so
 when it feels the influence of a deep-layer trough west of
 California.  A slow down and turn toward the northeast or east is
 expected after that time when the shallow system is steered by the
 low-level flow toward the Baja California peninsula.  No significant
 change was made to the previous track forecast, and it lies close to
 the GFS/ECMWF consensus.
 
 Although the system is weakening quickly, tropical moisture
 associated with Norbert and the Pacific ITCZ will continue to
 spread northward across northern Mexico and the southwestern United
 States.  This could result in heavy rains and life-threatening flash
 flooding in these area during the next day or two. Please see
 information from your local weather office for more details.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  07/1500Z 26.0N 117.0W   50 KT  60 MPH
  12H  08/0000Z 26.9N 117.7W   35 KT  40 MPH
  24H  08/1200Z 27.9N 118.2W   30 KT  35 MPH...POST-TROP/REMNT LOW
  36H  09/0000Z 28.5N 118.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
  48H  09/1200Z 29.1N 117.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
  72H  10/1200Z 29.5N 116.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
  96H  11/1200Z...DISSIPATED
 
 $$
 Forecaster Cangialosi