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WTNT45 KNHC 250859
TCDAT5

TROPICAL DEPRESSION TEN DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL102011
500 AM EDT THU AUG 25 2011

THE AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE SEVERAL
HUNDRED MILES WEST-SOUTHWEST OF THE SOUTHERN CAPE VERDE ISLANDS HAS
ACQUIRED SUFFICIENT ORGANIZATION TO BE DECLARED A TROPICAL
DEPRESSION.  THE CENTER APPEARS TO BE LOCATED NEAR THE NORTHEAST
TIP OF A CURVED BAND WRAPPING AROUND THE WESTERN SEMICIRCLE.
SATELLITE INTENSITY ESTIMATES ARE AT T2.5 FROM TAFB AND SAB WHICH
SUGGEST THAT THE DEPRESSION COULD BE NEAR TROPICAL STORM STRENGTH.
HOWEVER...GIVEN THE UNCERTAINTY REGARDING THE CENTER LOCATION AND
THE RECENT WARMING OF CONVECTIVE TOPS NEAR THE ESTIMATED CENTER...A
MORE CONSERVATIVE ASSESSMENT OF THE INTENSITY SEEMS MOST PRUDENT.
THE INITIAL INTENSITY IS SET AT 30 KT.

SINCE THE CENTER HAS NOT BEEN WELL FORMED...THE INITIAL MOTION
ESTIMATE IS A FAIRLY UNCERTAIN 280/10.  THE DEPRESSION SHOULD
DECELERATE ON A WEST-NORTHWESTWARD AND THEN NORTHWESTWARD COURSE
DURING THE NEXT DAY OR TWO AS IT NEARS THE WESTERN EDGE OF A LOW-
TO MID-LEVEL RIDGE OVER THE FAR EASTERN ATLANTIC.  GLOBAL MODELS
SHOW A WEAKNESS IN THE RIDGE ALONG 35W IN 2-3 DAYS WHICH SHOULD
BECOME MORE PRONOUNCED AS A MID- TO UPPER-LEVEL TROUGH BEGINS TO
DIG SOUTHWARD OVER THE NORTHEAST ATLANTIC.  THIS SHOULD CAUSE THE
TRACK OF THE CYCLONE TO TURN TOWARD THE NORTH-NORTHWEST AND
POSSIBLY THE NORTH LATER IN THE FORECAST PERIOD.  THE TRACK AROUND
96-120 HOURS IS HIGHLY DEPENDENT ON THE VERTICAL INTEGRITY OF THE
CYCLONE...WITH A WEAKER/SHALLOWER SYSTEM LIKELY LYING WEST OF THE
FORECAST TRACK.  THE OFFICIAL NHC TRACK IS CLOSE TO THE MULTI-MODEL
CONSENSUS TVCN.

EVEN THOUGH THE DEPRESSION SHOULD TRACK OVER WARM ENOUGH WATERS
DURING THE NEXT COUPLE OF DAYS...ANALYSES FROM UW-CIMSS CURRENTLY
SHOW 15-20 KT OF NORTHEASTERLY SHEAR OVER THE DEPRESSION WHICH
IS FORECAST BY THE SHIPS MODEL TO CONTINUE.  ALTHOUGH A TEMPORARY
REDUCTION OF THE SHEAR COULD OCCUR IN ABOUT 48 HOURS...THE ABRUPT
TURN OF THE CYCLONE TOWARD THE NORTH-NORTHWEST BEYOND THIS TIME WILL
BRING IT OVER 25C-26C WATERS AND LATER IN A REGION OF INCREASING
SOUTHWESTERLY SHEAR ASSOCIATED WITH THE SOUTHWARD EXTENSION OF AN
UPPER-LEVEL TROUGH OVER THE NORTHEAST ATLANTIC. THE OFFICIAL NHC
INTENSITY FORECAST IS IN GOOD AGREEMENT WITH THE MULTI-MODEL
CONSENSUS THROUGH 48 HOURS...SHOWING SLOW STRENGTHENING. WEAKENING
IS INDICATED AFTER THAT TIME IN LIGHT OF THE NEGATIVE ENVIRONMENTAL
FACTORS THE CYCLONE IS FORECAST TO ENCOUNTER AND IS BELOW MOST THE
GUIDANCE.

FORECAST POSITIONS AND MAX WINDS

INIT  25/0900Z 12.4N  30.4W   30 KT  35 MPH
 12H  25/1800Z 12.8N  31.8W   35 KT  40 MPH
 24H  26/0600Z 13.5N  33.4W   40 KT  45 MPH
 36H  26/1800Z 14.5N  34.3W   45 KT  50 MPH
 48H  27/0600Z 15.5N  35.1W   50 KT  60 MPH
 72H  28/0600Z 17.7N  36.1W   45 KT  50 MPH
 96H  29/0600Z 20.0N  37.0W   35 KT  40 MPH
120H  30/0600Z 22.5N  38.5W   30 KT  35 MPH

$$
FORECASTER KIMBERLAIN