368 
 WTNT44 KNHC 240849
 TCDAT4
 
 TROPICAL DEPRESSION FOUR DISCUSSION NUMBER   3
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL042014
 500 AM AST SUN AUG 24 2014
 
 The satellite presentation of the tropical depression has gradually
 improved overnight.  Convection has increased to the northeast
 of the center and a little more banding is noted.   Although the
 pressure has dropped a few millibars during the past 6 to 12 hours,
 data from an Air Force Reserve Hurricane Hunter aircraft
 indicate that the cyclone remains a 30-kt tropical depression.
 
 Fixes from the aircraft yield an initial motion of 325/8 kt. The
 cyclone is expected to slow down and turn north-northwestward today
 into a break in the ridge caused by a mid- to upper-level trough
 that is currently moving off the U.S. east coast.  This trough is
 forecast to dig southeastward during the next 24 to 36 hours before
 lifting northeastward on Tuesday.  The track guidance has shifted
 significantly eastward this cycle, with the exception of the latest
 ECMWF, which is very similar to its 1200 UTC run.  The eastward
 shift in most of the models appears to be the result of increased
 interaction of the cyclone with the aforementioned trough during the
 next 48 hours.  This leads to a more north-northwestward or
 northward motion during the next day or so.  Once the trough lifts
 out, most of the guidance shows a bend back toward the northwest,
 before the cyclone turns northward and northeast around a
 subtropical ridge to its east.  The NHC track has been shifted
 eastward, but it remains along the western side of the
 guidance envelope out of respect for the ECMWF and continuity of the
 previous forecasts. The new track forecast is closest to the HWRF,
 but is well west of the latest multi-model consensus.  Future
 eastward adjustments may be required if the eastward model trend
 continues.  Given that a large spread remains in the guidance,
 the confidence in the track forecast remains lower than normal.
 
 Light to moderate northwesterly shear is expected during the next
 few days.  However, the shear is not expected to be strong enough to
 prevent strengthening, and the official forecast calls for gradual
 intensification throughout the forecast period. The NHC intensity
 forecast is close to the SHIPS guidance and the intensity
 consensus ICON.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  24/0900Z 22.9N  73.3W   30 KT  35 MPH
  12H  24/1800Z 23.7N  73.7W   40 KT  45 MPH
  24H  25/0600Z 24.4N  73.9W   45 KT  50 MPH
  36H  25/1800Z 25.0N  74.0W   50 KT  60 MPH
  48H  26/0600Z 25.9N  74.1W   55 KT  65 MPH
  72H  27/0600Z 28.5N  75.5W   60 KT  70 MPH
  96H  28/0600Z 31.5N  75.0W   65 KT  75 MPH
 120H  29/0600Z 34.0N  70.0W   70 KT  80 MPH
 
 $$
 Forecaster Brown