| TROPICAL DEPRESSION FOURTEEN ADVISORY NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011 500 PM AST TUE SEP 06 2011 ...NEW TROPICAL DEPRESSION FORMS IN THE FAR EASTERN ATLANTIC... SUMMARY OF 500 PM AST...2100 UTC...INFORMATION ---------------------------------------------- LOCATION...11.8N 37.0W ABOUT 920 MI...1480 KM WSW OF THE CAPE VERDE ISLANDS ABOUT 1650 MI...2655 KM E OF THE LESSER ANTILLES MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H PRESENT MOVEMENT...WNW OR 285 DEGREES AT 18 MPH...30 KM/H MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES WATCHES AND WARNINGS -------------------- THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT. DISCUSSION AND 48-HOUR OUTLOOK ------------------------------ AT 500 PM AST...2100 UTC...THE CENTER OF NEWLY FORMED TROPICAL DEPRESSION FOURTEEN WAS LOCATED NEAR LATITUDE 11.8 NORTH... LONGITUDE 37.0 WEST. THE DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST NEAR 18 MPH...30 KM/H...AND THIS GENERAL MOTION IS EXPECTED TO CONTINUE DURING THE NEXT TWO DAYS. MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/H...WITH HIGHER GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS AND THE DEPRESION COULD BECOME A TROPICAL STORM TONIGHT OR WEDNESDAY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES. HAZARDS AFFECTING LAND ---------------------- NONE NEXT ADVISORY ------------- NEXT COMPLETE ADVISORY...1100 PM AST. $$ FORECASTER AVILA TROPICAL DEPRESSION FOURTEEN DISCUSSION NUMBER 1 NWS NATIONAL HURRICANE CENTER MIAMI FL AL142011 500 PM EDT TUE SEP 06 2011 SATELLITE IMAGES INDICATE THAT A TROPICAL DEPRESSION HAS FORMED WITHIN THE AREA OF DISTURBED WEATHER IN THE FAR EASTERN ATLANTIC. THERE HAS BEEN AN INCREASE IN THE ORGANIZED CONVECTION PRIMARILY IN BANDS TO THE NORTH AND WEST OF THE CENTER...AND THE UPPER-LEVEL OUTFLOW IS WELL ESTABLISHED PRIMARILY IN THE WESTERN SEMICIRCLE. DVORAK T-NUMBERS FROM TAFB AND SAB HAVE INCREASED TO 2.0 ON THE DVORAK SCALE LEADING TO AN INITIAL INTENSITY OF 30 KNOTS. SATELLITE IMAGES SHOW THAT THE DEPRESSION IS CURRENTLY ON A DEVELOPING TREND...BUT GLOBAL MODELS INDICATE THAT THE UPPER-LEVEL WINDS ARE ONLY MARGINALLY FAVORABLE FOR STRENGTHENING ALONG THE PATH OF THE CYCLONE. THE OFFICIAL FORECAST CALLS FOR GRADUAL INTENSIFICATION... FOLLOWING THE LGEM MODEL. NONE OF THE GUIDANCE SUGGEST SIGNIFICANT STRENGTHENING...BUT THE DEPRESSION IS EXPECTED TO BE A HURRICANE AS IT NEARS THE LEEWARD ISLANDS. SINCE THE DEPRESSION HAS JUST FORMED AND WE DID NOT HAVE A WELL DEFINED CENTER BEFORE...THE INITIAL MOTION IS UNCERTAIN. IT APPEARS THAT THE DEPRESSION IS MOVING TOWARD THE WEST-NORTHWEST AT 16 KNOTS ON THE SOUTH SIDE OF THE ATLANTIC SUBTROPICAL RIDGE. THIS PATTERN IS FORECAST TO PERSIST...SO THIS GENERAL MOTION WITH A GRADUAL DECREASE IN FORWARD SPEED IS EXPECTED THROUGH FIVE DAYS. THE TRACK GUIDANCE IS UNCERTAIN WITH THE GFS MOVING THE CYCLONE VERY FAST ON A WEST-NORTHWEST TO NORTHWESTWARD TRACK...AND THE ECMWF A LITTLE SLOWER AND FARTHER TO THE SOUTH. HOWEVER...IT APPEARS THAT THESE TWO RELIABLE MODELS ARE GRADUALLY COMING INTO BETTER AGREEMENT. THE OFFICIAL FORECAST TRACK IS BIASED A LITTLE SLOWER TOWARD THE ECMWF. FORECAST POSITIONS AND MAX WINDS INIT 06/2100Z 11.8N 37.0W 30 KT 35 MPH 12H 07/0600Z 12.3N 39.6W 35 KT 40 MPH 24H 07/1800Z 12.9N 43.8W 40 KT 45 MPH 36H 08/0600Z 13.7N 47.5W 45 KT 50 MPH 48H 08/1800Z 14.5N 50.7W 50 KT 60 MPH 72H 09/1800Z 16.0N 57.0W 55 KT 65 MPH 96H 10/1800Z 17.0N 62.0W 60 KT 70 MPH 120H 11/1800Z 19.5N 66.5W 65 KT 75 MPH $$ FORECASTER AVILA |