000
WTNT43 KNHC 190255
TCDAT3
 
TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL082011
1100 PM EDT THU AUG 18 2011
 
SATELLITE IMAGES DURING THE LAST FEW HOURS BEFORE SUNSET INDICATED
THAT THE LOW-LEVEL CIRCULATION OF THE WAVE OVER THE WESTERN
CARIBBEAN SEA WAS BECOMING BETTER DEFINED WITH LOW CLOUDS MOVING
WITHIN NORTHWESTERLY FLOW OFFSHORE OF THE COAST OF NORTHEASTERN
HONDURAS. MICROWAVE DATA FROM THE PAST SEVERAL HOURS CONFIRM THAT
THE SYSTEM HAS A LOW-LEVEL CIRCULATION AND A RECENT 0134Z SSMIS
PASS EVEN HAS A WEAK RING FEATURE IN THE 37 GHZ CHANNEL.
SIGNIFICANT 24H PRESSURE FALLS OF 3 TO 4 MB HAVE ALSO BEEN OBSERVED
AT BUOY 42057...WHICH HAVE LONG BEEN A HALLMARK OF TROPICAL CYCLONE
FORMATION.  DVORAK ESTIMATES OF T2.0 FROM BOTH TAFB AND SAB...IN
ADDITION TO THE ABOVE DATA...SUPPORT ADVISORIES BEING INITIATED ON
A TROPICAL DEPRESSION.  A PEAK 1-MIN WIND OF 27 KT FROM THE BUOY
AND EARLIER ASCAT DATA SUGGEST AN INITIAL INTENSITY OF ABOUT 30 KT. 
 
THE DEPRESSION DOES NOT HAVE MUCH TIME TO STRENGTHEN BEFORE
THE CIRCULATION INTERACTS WITH THE NORTHERN COAST OF HONDURAS.
ONLY MODEST STRENGTHENING IS FORECAST...WHICH IS IN GOOD AGREEMENT
WITH THE MODEL CONSENSUS.  GIVEN HOW CLOSE THE SYSTEM IS TO
LAND...IT IS ALSO QUITE POSSIBLE THE DEPRESSION MAY NOT STRENGTHEN
AT ALL AND WEAKEN OVER THE HIGHER TERRAIN OF HONDURAS.
 
THE INITIAL MOTION ESTIMATE IS 270/10.  A MID-LEVEL RIDGE OVER THE
GULF OF MEXICO SHOULD GENERALLY STEER THE SYSTEM TO THE WEST OVER
THE NEXT SEVERAL DAYS.  THIS SCENARIO IS SUPPORTED BY MOST OF THE
GLOBAL MODELS...WITH THE GFDL FORECAST OF THE DEPRESSION MOVING
INTO THE SOUTHERN BAY OF CAMPECHE BEING CONSIDERED AN UNLIKELY
SOLUTION.  THE NHC FORECAST LIES BETWEEN THE DYNAMICAL MODEL
CONSENSUS AND THE ECMWF MODEL.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  19/0300Z 15.4N  82.1W   30 KT  35 MPH
 12H  19/1200Z 15.5N  83.4W   30 KT  35 MPH
 24H  20/0000Z 15.7N  84.9W   35 KT  40 MPH...INLAND
 36H  20/1200Z 15.9N  86.6W   35 KT  40 MPH...OVER WATER
 48H  21/0000Z 16.2N  88.5W   35 KT  40 MPH
 72H  22/0000Z 17.0N  93.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  23/0000Z...DISSIPATED
 
$$
FORECASTER BLAKE/BROWN