971 
 WTPZ44 KNHC 041453
 TCDEP4
 
 HURRICANE NORBERT DISCUSSION NUMBER   9
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP142014
 800 AM PDT THU SEP 04 2014
 
 Norbert has become a little better organized overnight, with the
 TRMM and AMSR2 microwave sensors indicating that the low- and
 mid-level centers have become more vertically aligned.  The cyclone
 is still experiencing northeasterly shear though, given the
 asymmetric shape on the latest satellite images. Dvorak intensity
 estimates are all near 75 kt, so that will used as the initial wind
 speed.  An Air Force Hurricane Hunter aircraft is en route to
 investigate Norbert, and should provide a more precise estimate of
 its intensity.
 
 While moderate shear has been affecting the cyclone, it has not
 been strong enough to prevent slow strengthening.  Although the
 shear is not forecast to change much over the next few days,
 Norbert is expected to move into an environment characterized by
 cooler SSTs and drier, more stable air.  These negative factors
 should cause some weakening on Friday, with a more significant
 downward trend anticipated by late this weekend.  The latest NHC
 forecast is close to a blend of the previous interpolated forecast
 and the intensity consensus.  Norbert should become a remnant low in
 about 4 days due to it moving over very cool waters west of Baja
 California.
 
 The track of Norbert has been quite erratic over the past 24 hours,
 but a 12-hour motion still appears to be northwestward at about 6
 kt.  A mid-level ridge is expected to remain over northwestern
 Mexico, keeping Norbert on the same general course during the next
 few days, offshore of Baja California.  At long range, model
 guidance remains divergent on how much of a northward turn that
 Norbert will take due to a mid-latitude trough weakening the ridge.
 The 3-5 day track also partially depends on the intensity at that
 time range, with a deeper system probably moving farther west, more
 like the ECMWF solution.  Since there has not been much change to
 the overall guidance, the new NHC forecast is about the same as the
 previous one, and remains relatively close to the dynamical model
 consensus.
 
 Moisture from the remnants of Dolly and the Pacific ITCZ is being
 advected northward by the outer circulation of Norbert across
 northern Mexico and into the southwestern United States. This could
 result in heavy rains and life-threatening flash flooding in these
 areas during the next few days.  Please see information from your
 local weather office for more details.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  04/1500Z 20.7N 110.4W   75 KT  85 MPH
  12H  05/0000Z 21.5N 111.1W   80 KT  90 MPH
  24H  05/1200Z 22.5N 112.2W   80 KT  90 MPH
  36H  06/0000Z 23.5N 113.3W   75 KT  85 MPH
  48H  06/1200Z 24.3N 114.5W   65 KT  75 MPH
  72H  07/1200Z 25.9N 117.0W   50 KT  60 MPH
  96H  08/1200Z 27.6N 118.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
 120H  09/1200Z 29.0N 119.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Blake