554 
 WTPZ41 KNHC 271500
 TCDEP1
 
 HURRICANE AMANDA DISCUSSION NUMBER  20
 NWS NATIONAL HURRICANE CENTER MIAMI FL       EP012014
 800 AM PDT TUE MAY 27 2014
 
 Amanda's eye has again disappeared from the infrared and
 first-light visible imagery from GOES-West this morning.  However,
 microwave imagery from the TRMM and SSMI polar-orbiting satellites
 still indicated a small, complete eyewall was present.  Using
 a blend of final T and Dvorak current intensity estimates from TAFB
 and SAB suggests an intensity of 100-105 kt, while the ADT estimate
 of 125 kt appears to be too high.  The initial intensity is set at
 105 kt, but this may be slightly too strong if the current
 deterioration of the convective structure continues.  The initial
 wind radii are primarily based upon a 0518Z ASCAT-A scatterometer
 pass.
 
 The microwave imagery fixes allow for a fairly confident assessment
 of the initial position and motion of Amanda.  The hurricane is
 moving toward the north-northwest - 340 degrees - at about 5 kt, due
 to the steering influence of an upper- to mid-level low to its
 northwest and a ridge to its northeast.  These features should
 continue to slowly advect Amanda toward the north or north-northeast
 for the next three days or so, before a strong northeast-southwest
 oriented ridge builds north of the tropical cyclone.  That ridge,
 along with a weakening Amanda being steered by the low-level flow,
 should result in Amanda turning to the southwest in the latter part
 of the forecast period.  The models are in generally good agreement
 with this scenario, but differ some on when the turn occurs, and
 thus how far to the north Amanda reaches.  On the extremes, the GFS
 has Amanda getting farthest to the north at 21N while the UKMET only
 has the cyclone reaching 17N before the turn occurs.  The official
 forecast is a blend of the farther north TVCE variable consensus
 technique and the farther south previous official forecast.
 
 The CIMSS analysis and the GFS-based SHIPS both indicate southerly
 vertical shear of about 20 kt affecting Amanda.  While the shear is
 anticipated to diminish quite a bit by all of the dynamical models
 in about two days, the moisture and instability should decrease
 significantly at the same time.  The dynamical models very quickly
 weaken Amanda, while the dynamical-statistical guidance shows more
 gradual weakening.  However, it appears that the SSTs being used in
 SHIPS/LGEM are biased high by about 1 degree C along the track of
 Amanda, which would suggest that these statistical techniques are
 somewhat too strong. The official forecast is very similar to
 the IVCN variable consensus model and the previous advisory.
 However, if current convective trends continue and the statistical
 models do indeed turn out to be biased high, then this forecast may
 be conservative in how quickly Amanda falls apart.
 
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  27/1500Z 14.7N 112.3W  105 KT 120 MPH
  12H  28/0000Z 15.2N 112.3W   90 KT 105 MPH
  24H  28/1200Z 15.8N 111.8W   75 KT  85 MPH
  36H  29/0000Z 16.6N 111.2W   60 KT  70 MPH
  48H  29/1200Z 17.5N 110.6W   50 KT  60 MPH
  72H  30/1200Z 18.5N 110.0W   40 KT  45 MPH
  96H  31/1200Z 18.0N 110.5W   30 KT  35 MPH
 120H  01/1200Z 17.5N 111.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 
 $$
 Forecaster Landsea