630 
 WTNT45 KNHC 141505
 TCDAT5
 TROPICAL STORM OMAR DISCUSSION NUMBER   5
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL152008
 1100 AM EDT TUE OCT 14 2008
  
 SATELLITE AND RADAR DATA INDICATE THE DEPRESSION HAS CONTINUED TO
 BECOME BETTER ORGANIZED AND CLOUD TOPS HAVE COOLED SIGNIFICANTLY
 WITH SOME TOPS TO -86C NEAR THE CENTER. OUTFLOW HAS ALSO IMPROVED
 IN ALL QUADRANTS AND IS LESS RESTRICTED TO THE NORTHWEST NOW. THE
 INITIAL ADVISORY OF 35 KT IS BASED ON A CONSENSUS T2.5/35 KT
 SATELLITE ESTIMATE FROM TAFB AND SAB FOR THE PAST 12 HOURS...PLUS
 SEVERAL BELIEVABLE 30-34 KT QUIKSCAT WIND VECTORS NOTED IN THE
 NORTHWEST QUADRANT AROUND 1036Z THIS MORNING. THUS...TROPICAL
 DEPRESSION FIFTEEN HAS BEEN UPGRADED TO TROPICAL STORM OMAR.
 
 THE INITIAL MOTION ESTIMATE IS 115/02. OMAR HAS BEEN DRIFTING SOUTH
 TO SOUTHEASTWARD THE PAST 12 HOURS...AND CURRENTLY SHOWS NO SIGN OF
 CHANGING THAT MOTION. HOWEVER...ALL OF THE AVAILABLE MODEL GUIDANCE
 INDICATES THAT A BROAD DEEP MID-LATITUDE TROUGH OVER THE CENTRAL
 AND WESTERN ATLANTIC WILL CONTINUE TO DROP SOUTHWARD AND GRADUALLY
 PICK UP OMAR AND NUDGE IT TO THE EAST DURING THE NEXT 12 HOURS...
 AND THEN ACCELERATE IT TO THE NORTHEAST AFTER THAT. THE LATEST
 TREND IN WATER VAPOR IMAGERY SUPPORTS THIS SCENARIO AS A PIECE OF
 SHORTWAVE ENERGY ALONG 70W LONGITUDE CAN BE SEEN DIGGING DUE SOUTH.
 NHC MODEL GUIDANCE IS TIGHTLY CLUSTERED CROSS-WISE...BUT THERE ARE
 SIGNIFICANT DIFFERENCES IN THE FORWARD SPEED AND JUST HOW SOON OMAR
 GETS PICKED UP BY THE AFOREMENTIONED TROUGH. THE OFFICIAL FORECAST
 TRACK HAS BEEN SHIFTED TO THE EAST OR RIGHT OF THE PREVIOUS TRACK
 ...MAINLY DUE TO THE MORE EASTWARD INITIAL POSITION...BUT NOT AS FAR
 EAST OR AS FAST AS THE MODEL CONSENSUS.
 
 RECENT DEVELOPMENT OF A CDO-LIKE AREA OF CENTRAL DEEP CONVECTION
 SUGGESTS THAT OMAR MAY BE STARTING A PERIOD OF RAPID STRENGTHENING.
 IN ADDITION...A LARGE MASS OF CONVECTION IN THE EASTERN SEMICIRCLE
 THAT HAS BEEN DISRUPTING INFLOW INTO THE CIRCULATION CENTER HAS
 WEAKENED CONSIDERABLY...WHICH SHOULD ALLOW FOR MORE CONVECTIVE
 FORCING TO OCCUR NEAR THE LOW-LEVEL CENTER. THE IMPROVING OUTFLOW
 PATTERN AND A FORECAST OF DECREASING VERTICAL WIND SHEAR OF LESS
 THAN 10 KT FOR THE NEXT 24 HOURS FURTHER SUPPORTS A FORECAST OF
 STEADY INTENSIFICATION OF AT LEAST ONE T-NUMBER PER DAY FOR THE
 NEXT 24 HOURS. AFTER THAT...SOUTHWESTERLY VERTICAL WIND SHEAR AHEAD
 OF THE LARGE MID-LATITUDE TROUGH IS EXPECTED TO INCREASE TO GREATER
 THAN 20 KT...SO THE INTENSIFICATION TREND SHOULD SLOW DOWN BY DAY 2
 AND BEYOND. THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO THE
 PREVIOUS ADVISORY AND IS A BLEND OF THE SHIPS...GFDL...AND HWRF
 MODELS.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      14/1500Z 14.0N  69.0W    35 KT
  12HR VT     15/0000Z 14.7N  68.3W    45 KT
  24HR VT     15/1200Z 15.8N  67.3W    55 KT
  36HR VT     16/0000Z 17.3N  65.6W    60 KT
  48HR VT     16/1200Z 19.1N  63.6W    65 KT
  72HR VT     17/1200Z 23.8N  60.0W    65 KT
  96HR VT     18/1200Z 28.0N  58.0W    65 KT
 120HR VT     19/1200Z 33.0N  55.0W    65 KT
  
 $$
 FORECASTER STEWART