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TROPICAL DEPRESSION NINE DISCUSSION NUMBER   1
NATIONAL WEATHER SERVICE MIAMI FL
5 PM EDT WED SEP 19 2001
 
DURING THE PAST 6 HOURS...SATELLITE AND SURFACE OBSERVATIONS 
INDICATE THAT THE STRONG TROPICAL WAVE OVER THE SOUTHWEST CARIBBEAN 
SEA HAS DEVELOPED INTO TROPICAL DEPRESSION NINE. THE LOW-LEVEL 
CIRCULATION IS BROAD AND APPEARS TO HAVE TWO CENTERS...ONE EAST OF 
COSTA RICA AND ANOTHER ONE EAST OF PUERTO CABEZAS NICARAGUA.  SINCE 
THE STRONGEST AND MOST PERSISTENT DEEP CONVECTION IS ASSOCIATED WITH 
THE NORTHERNMOST CENTER...I HAVE OPTED TO START ADVISORIES ON THAT 
CIRCULATION.  UPPER-LEVEL OUTFLOW IS VERY CIRCULAR AND QUITE 
IMPRESSIVE...MORE INDICATIVE OF A MATURE TROPICAL CYCLONE.

THE INITIAL MOTION ESTIMATE IS 285/15.  ON THIS TRACK...THE 
DEPRESSION WILL BE INLAND OVER EASTERN NICARAGUA IN 6 TO 12 HOURS. 
MOST OF THE NHC MODEL GUIDANCE TAKES THE SYSTEM WESTWARD INTO THE 
NORTHEASTERN PACIFIC OCEAN IN 36 HOURS. HOWEVER...SOME OF THE GLOBAL 
MODELS SPLIT THE SYSTEM INTO TWO SEPARATE CIRCULATION CENTERS. THE 
SOUTHERNMOST CENTER IS FORECAST TO TRACK WESTWARD ACROSS COSTA RICA 
AND RE-DEVELOP INTO A SIGNIFICANT TROPICAL CYCLONE IN THE 
NORTHEASTERN PACIFIC IN 48 TO 72 HOURS...WHILE THE NORTHERNMOST 
CENTER TRACKS WEST-NORTHWESTWARD AND SLOWS DOWN NEAR THE SOUTHERN 
BAY OF CAMPECHE IN 72 HOURS.  I HAVE OPTED TO TAKE THE MORE NORTHERN 
TRACK BASED ON THAT CIRCULATION CURRENTLY BEING EMBEDDED IN THE 
STRONGEST CONVECTION.

AIR FORCE RECON AIRCRAFT WAS DELAYED IN TAKING OFF AND WILL NOT BE 
IN THE DEPRESSION UNTIL 2230Z.  IT IS STILL POSSIBLE THAT THE 
CYCLONE COULD STRENGTHEN INTO A TROPICAL STORM JUST BEFORE MAKING 
LANDFALL IN ABOUT 6 HOURS OR SO.  TROPICAL STORM WATCHES HAVE BEEN 
POSTED ALONG THE CARIBBEAN COASTS OF NICARAGUA...HONDURAS... 
GUATEMALA...AND SOUTHERN BELIZE IN THE EVENT THAT STRONGER WINDS 
DEVELOP IN THE CONVECTIVE BANDS OVER WATER TO THE NORTH AND EAST OF 
THE CENTER LATER TONIGHT AND TOMORROW.  IF THE DEPRESSION TRACKS A 
LITTLE FARTHER NORTH THAN FORECAST AND THE CENTER REMAINS OVER WATER
...THEN MORE STRENGTHENING WOULD OCCUR THAN IS INDICATED BY THE 
OFFICIAL FORECAST.  REGENERATION INTO A SIGNIFICANT TROPICAL CYCLONE 
OVER THE SOUTHERN BAY OF CAMPECHE IS ALSO POSSIBLE IN 72 HOURS. 
HOWEVER...THE PRIMARY THREAT FROM THIS CYCLONE WILL BE HEAVY 
RAINFALL AND INLAND FRESH WATER FLOODING.
 
FORECASTER STEWART
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     19/2100Z 13.9N  82.5W    30 KTS
12HR VT     20/0600Z 14.3N  84.8W    30 KTS...INLAND
24HR VT     20/1800Z 15.0N  87.5W    25 KTS...INLAND
36HR VT     21/0600Z 15.9N  89.8W    25 KTS...INLAND
48HR VT     21/1800Z 16.9N  91.8W    20 KTS...INLAND
72HR VT     22/1800Z 18.0N  94.0W    25 KTS...INLAND NEAR COAST
 
 
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