000
WTNT43 KNHC 042042
TCDAT3

HURRICANE BERTHA DISCUSSION NUMBER  16
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL032014
500 PM EDT MON AUG 04 2014

Bertha continues to have a disorganized appearance on satellite
imagery.  A small burst of deep convection is occurring just east
of the center, and the system continues to have well-defined
upper-level outflow over the southeastern quadrant.  A NOAA
Hurricane Hunter aircraft is currently investigating the tropical
cyclone, and we shall soon see if Bertha is maintaining hurricane
status.  Based on wind data from an Air Force mission earlier this
afternoon, which showed a slight decrease, the current intensity is
reduced to 65 kt.  Flight-level wind data from that earlier mission
also showed that the circulation had a very small extent over the
northwestern quadrant, and high-resolution visible imagery shows low
clouds moving northwestward, away from the center, not far from the
center over that quadrant.  This suggests that, if the environmental
low-level flow increases, Bertha may have a difficult time
maintaining a closed circulation.  For now, the NHC intensity
forecast calls for gradual weakening, and is a little below most of
the guidance since the shear is predicted to become prohibitively
strong, 50 kt or more, in just 36 hours.

Fixes from the aircraft showed a gradual increase in forward speed
and the initial motion is around 360/15.  There are no important
changes to the track forecast or reasoning.  During the next couple
of days, Bertha will be moving between a mid-level high pressure
area over the southwestern Atlantic and a broad trough moving off
the northeast United States coast.  This should result in a gradual
turn toward the north-northeast and northeast with additional
acceleration during the next 24-48 hours.  Later in the forecast
period, Bertha or its post-tropical counterpart should accelerate
east-northeastward in the mid-latitude westerlies over the north
Atlantic.  The official forecast is similar to the previous one and
lies between the latest GFS and ECMWF tracks.

FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 29.4N  73.6W   65 KT  75 MPH
 12H  05/0600Z 31.8N  72.8W   65 KT  75 MPH
 24H  05/1800Z 34.7N  70.7W   65 KT  75 MPH
 36H  06/0600Z 37.5N  67.0W   60 KT  70 MPH
 48H  06/1800Z 40.0N  62.0W   55 KT  65 MPH
 72H  07/1800Z 47.0N  50.0W   50 KT  60 MPH...POST-TROP/EXTRATROP
 96H  08/1800Z 49.0N  37.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
120H  09/1800Z 49.0N  24.0W   40 KT  45 MPH...POST-TROP/EXTRATROP

$$
Forecaster Pasch