[Tropical] Tropical Cyclone Discussion

[EMWIN Server]

WTNT42 KNHC 031438
TCDAT2

TROPICAL STORM KAREN DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122013
1000 AM CDT THU OCT 03 2013

KAREN CONTINUES TO HAVE A SOMEWHAT SHEARED APPEARANCE ON SATELLITE
IMAGERY...WITH THE DEEP CONVECTION DISPLACED TO THE NORTHEAST OF THE
LOW-LEVEL CENTER. THIS IS CONSISTENT WITH THE 20 OR SO KT OF SHEAR
ANALYZED OVER THE CYCLONE BY THE SHIPS MODEL. THE INITIAL INTENSITY
IS RAISED TO 55 KT BASED ON SEVERAL BIAS-CORRECTED SFMR WINDS IN
THE 50-55 KT RANGE REPORTED BY THE AIRCRAFT. WITH MODERATE SHEAR
EXPECTED TO CONTINUE...ONLY GRADUAL STRENGTHENING IS EXPECTED
BEFORE THE SHEAR INCREASES FURTHER IN ABOUT 48 HOURS. SOME
WEAKENING IS ANTICIPATED AS KAREN APPROACHES THE GULF COAST...BUT
THE STORM COULD STILL BE NEAR HURRICANE STRENGTH AT LANDFALL. THE
NHC FORECAST IS CLOSE TO THE SHIPS AND LGEM MODELS THROUGH THE
PERIOD. KAREN SHOULD BE INVOLVED WITH A FRONTAL ZONE BY DAY 4 AND
ABSORBED BY THE FRONT BY DAY 5.

THE INITIAL MOTION ESTIMATE IS STILL A RELATIVELY UNCERTAIN 330/10.
THE TRACK FORECAST REASONINS HAS NOT CHANGED...AS KAREN WILL MOVE
AROUND THE PERIPHERY OF THE SUBTROPICAL RIDGE DURING THE NEXT DAY
OR SO AND THEN ACCELERATE NORTHEASTWARD AHEAD OF A MID/UPPER-LEVEL
TROUGH. THERE REMAINS CONSIDERABLE EAST/WEST SPREAD IN THE TRACK
GUIDANCE...WITH THE GFS REMAINING WELL EAST OF THE OTHER GLOBAL
MODELS AND ITS ENSEMBLE MEAN. THE TRACK GUIDANCE HAS SHIFTED A
LITTLE TO THE WEST THIS CYCLE...AND THE NEW NHC TRACK IS CLOSE TO
THE MULTI-MODEL CONSENSUS AND ABOUT A HALF A DEGREE LEFT OF THE
PREVIOUS TRACK THROUGH 48 HOURS. NOTE THAT A STRONGER STORM WOULD
LIKELY MOVER FARTHER EAST...WHILE A WEAKER SYSTEM WOULD BE MORE
LIKELY TO TAKE A TRACK FARTHER WEST.

FORECAST POSITIONS AND MAX WINDS

INIT  03/1500Z 22.2N  87.9W   55 KT  65 MPH
 12H  04/0000Z 23.8N  88.7W   60 KT  70 MPH
 24H  04/1200Z 25.4N  89.4W   60 KT  70 MPH
 36H  05/0000Z 26.9N  89.5W   65 KT  75 MPH
 48H  05/1200Z 28.2N  89.1W   60 KT  70 MPH
 72H  06/1200Z 31.0N  87.0W   45 KT  50 MPH...INLAND
 96H  07/1200Z 35.0N  81.5W   25 KT  30 MPH...POST-TROP/EXTRATROP
120H  08/1200Z...ABSORBED BY FRONT

$$
FORECASTER BRENNAN



This weather bulletin was brought to you by:
www.nashvilleweather.net