000
WTNT44 KNHC 241453
TCDAT4
 
TROPICAL STORM NADINE DISCUSSION NUMBER  48
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL142012
1100 AM AST MON SEP 24 2012

NADINE HAS BEEN MAINTAINING A BAND OF SHOWERS OVER THE NORTHWESTERN
PORTION OF THE CIRCULATION THIS MORNING.  AN ASCAT OVERPASS SHORTLY
BEFORE 1200 UTC THIS MORNING INDICATED 35-40 KT WINDS...SO THE
INITIAL INTENSITY REMAINS 45 KT.  LITTLE CHANGE IN WIND SPEED IS
EXPECTED DURING THE NEXT 24 TO 36 HOURS AS NADINE REMAINS OVER
MARGINAL SSTS...IN MODERATE SOUTHWESTERLY SHEAR...AND WITHIN A
FAIRLY DRY AIR MASS.  ENVIRONMENTAL CONDITIONS ARE FORECAST TO
BECOME A LITTLE MORE CONDUCIVE FOR STRENGTHENING IN A COUPLE OF
DAYS WHEN THE SHEAR IS EXPECTED TO RELAX AND NADINE MOVES OVER
SLIGHTLY WARMER WATERS.  LATE IN THE PERIOD....IT IS UNCLEAR AS TO
THE AMOUNT OF SHEAR NADINE WILL EXPERIENCE. THE GFS WHICH KEEPS
NADINE FARTHER SOUTH...SUGGESTS A LESS FAVORABLE UPPER-AIR PATTERN
THAN THE ECMWF WHICH TAKES THE STORM MORE NORTHWARD AND CLOSER TO
AN UPPER-LEVEL RIDGE AXIS.  GIVEN THE LARGE UNCERTAINTIES IN THE
LATTER PORTION OF THE PERIOD...THE NHC INTENSITY FORECAST IS A
LITTLE BELOW THE PREVIOUS ADVISORY AND JUST BELOW THE SHIPS/LGEM
GUIDANCE.

THE INITIAL MOTION ESTIMATE IS 295/6. NADINE SHOULD MOVE GENERALLY
WESTWARD DURING THE NEXT 24 HOURS. AFTER THAT TIME...NADINE IS
FORECAST TO TURN SOUTHWESTWARD AS ANOTHER BLOCKING RIDGE DEVELOPS
OVER THE CENTRAL ATLANTIC. THE TRACK GUIDANCE HAS BECOME MUCH MORE
DIVERGENT THAN YESTERDAY LATE IN THE FORECAST PERIOD. THE GFS AND
HWRF KEEP NADINE IN WEAK STEERING CURRENTS AND SHOW LITTLE OVERALL
MOTION FROM 72 TO 120 HOURS. ON THE OTHER EXTREME...THE ECMWF AND
UKMET TAKE NADINE NORTHWESTWARD AROUND THE WESTERN PERIPHERY OF A
MID-LEVEL RIDGE THAT SHIFTS EASTWARD OVER THE EASTERN ATLANTIC. FOR
NOW...THE NHC TRACK FORECAST SPLITS THE DIFFERENCE IN THE GUIDANCE
AND IS A BLEND OF THE PREVIOUS TRACK...THE FLORIDA STATE
SUPERENSEMBLE...AND THE TVCA MULTI-MODEL CONSENSUS. THE NEW
FORECAST IS A BIT SLOWER THAN THE PREVIOUS ADVISORY LATE IN THE
PERIOD.

FORECAST POSITIONS AND MAX WINDS
 
INIT  24/1500Z 31.7N  27.8W   45 KT  50 MPH
 12H  25/0000Z 31.9N  28.9W   45 KT  50 MPH
 24H  25/1200Z 31.7N  30.1W   45 KT  50 MPH
 36H  26/0000Z 31.2N  30.9W   45 KT  50 MPH
 48H  26/1200Z 30.6N  31.3W   50 KT  60 MPH
 72H  27/1200Z 29.8N  32.0W   55 KT  65 MPH
 96H  28/1200Z 30.0N  34.0W   60 KT  70 MPH
120H  29/1200Z 32.0N  35.0W   60 KT  70 MPH
 
$$
FORECASTER BROWN