| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

---

Tropical Storm LESLIE (Text)

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
 
TROPICAL STORM LESLIE DISCUSSION NUMBER  19
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122012
1100 PM AST MON SEP 03 2012
 
WEST-NORTHWESTERLY SHEAR CONTINUES TO KEEP THE STORM FROM BECOMING
BETTER ORGANIZED...WITH THE MAIN MASS OF DEEP CONVECTION DISPLACED
TO THE SOUTHEAST OF THE ESTIMATED CENTER LOCATION.  HOWEVER...A
RECENT ASCAT OVERPASS INDICATES THAT SOME SLIGHT STRENGTHENING HAS
OCCURRED...AND BASED ON THE SCATTEROMETER DATA THE CURRENT
INTENSITY IS SET TO 55 KT.  THIS IS ALSO CONSISTENT WITH THE LATEST
DVORAK ESTIMATES FROM TAFB AND SAB.  NOT MUCH ADDITIONAL
INTENSIFICATION IS LIKELY IN THE SHORT TERM AS THE DYNAMICAL
GUIDANCE DOES NOT SHOW THE SHEAR RELAXING SIGNIFICANTLY FOR THE NEXT
24 TO 36 HOURS.  LATER ON...HOWEVER...THE GLOBAL MODELS ARE
INSISTENT THAT THE UPPER-LEVEL WIND PATTERN WILL BECOME MORE
CONDUCIVE FOR STRENGTHENING...AS THE GFS DEPICTS A WELL-DEFINED AND
SYMMETRICAL UPPER-TROPOSPHERIC ANTICYCLONE BECOMING ESTABLISHED
OVER LESLIE IN ABOUT 72 HOURS.  THE OFFICIAL INTENSITY FORECAST IS
SIMILAR TO THAT FROM THE PREVIOUS ADVISORY...AND IS CLOSE TO A
BLEND OF THE LATEST LGEM AND SHIPS PREDICTIONS.
 
MICROWAVE AND GEOSTATIONARY SATELLITE FIXES INDICATE THAT THE STORM
HAS MOVED VERY LITTLE...IF AT ALL...SO THE INTIAL MOTION ESTIMATE
IS STATIONARY.  LESLIE IS EXPECTED TO MOVE QUITE SLOWLY IN A
GENERAL NORTHWARD DIRECTION WHILE IT REMAINS IN VERY WEAK STEERING
CURRENTS FOR A GOOD PART OF THE FORECAST PERIOD.  BY ABOUT 5
DAYS...THE FLOW BETWEEN A MID-TROPOSPHERIC TROUGH OVER THE EASTERN
U.S. AND AN ANTICYCLONE TO THE NORTHEAST OF THE TROPICAL CYCLONE
SHOULD INDUCE A SLIGHTLY FASTER NORTH-NORTHWESTWARD MOTION.  THE
OFFICIAL TRACK FORECAST IS ABOUT THE SAME AS THAT FROM THE PREVIOUS
ADVISORY AND REMAINS CLOSE TO THE MULTI-MODEL CONSENSUS TVCN.
 
BUOY OBSERVATIONS SHOW THAT WAVES GREATER THAN 12 FEET HIGH EXTEND
SOME 300-400 N MI FROM THE CENTER.  DUE TO THE LARGE SIZE OF THE
TROPICAL CYCLONE AND ITS EXPECTED SLOW MOTION...LARGE SWELLS
PROPAGATING AWAY FROM LESLIE WILL AFFECT BERMUDA AND NEARLY ALL OF
THE U.S. EAST COAST FOR MUCH OF THE WEEK.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/0300Z 24.0N  63.1W   55 KT  65 MPH
 12H  04/1200Z 24.6N  63.2W   55 KT  65 MPH
 24H  05/0000Z 25.3N  63.2W   55 KT  65 MPH
 36H  05/1200Z 25.8N  63.2W   55 KT  65 MPH
 48H  06/0000Z 26.3N  63.2W   60 KT  70 MPH
 72H  07/0000Z 27.2N  63.5W   70 KT  80 MPH
 96H  08/0000Z 28.5N  64.0W   80 KT  90 MPH
120H  09/0000Z 31.0N  65.0W   85 KT 100 MPH
 
$$
FORECASTER PASCH
 
NNNN