WTNT44 KNHC 312052 RRA

TCDAT4



TROPICAL STORM HERMINE DISCUSSION NUMBER  13

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092016

400 PM CDT WED AUG 31 2016



THE SYSTEM APPEARS BETTER ORGANIZED ON SATELLITE IMAGES THAN IT WAS

YESTERDAY, WITH MORE EVIDENCE OF CONVECTIVE BANDING FEATURES.

HOWEVER, BASED ON THE NOAA HURRICANE HUNTER DATA THE CENTER IS

STILL SITUATED NEAR THE NORTHERN EDGE OF THE MAIN CONVECTIVE CLOUD

MASS.  ALSO, DATA FROM THE AIRCRAFT SHOW A VERY ASYMMETRIC WIND

FIELD WITH ALL OF THE STRONG WINDS OCCURRING OVER THE EASTERN AND

SOUTHEASTERN PORTIONS OF THE CIRCULATION.  THE ADVISORY INTENSITY

IS SET TO 40 KT BASED ON SFMR-OBSERVED SURFACE WINDS FROM THE

HURRICANE HUNTERS.  HERMINE SHOULD BE IN AN ENVIRONMENT OF

MODERATE WEST-SOUTHWESTERLY SHEAR UNTIL IT NEARS THE COAST, WHEN

THE DYNAMICAL MODELS SHOW INCREASING SHEAR.  THE OFFICIAL INTENSITY

FORECAST HAS BEEN NUDGED UPWARD A BIT, AND THERE IS A DISTINCT

POSSIBILITY THAT HERMINE COULD BECOME A HURRICANE BEFORE LANDFALL.

THE PREDICTED EXTRATROPICAL TRANSITION OF THE SYSTEM IS BASED ON

THE LATEST GLOBAL MODEL FORECASTS, WHICH SHOW THE CYCLONE BECOMING

EMBEDDED WITHIN A FRONT OVER THE EASTERN UNITED STATES BY 72 HOURS.



THE AIRCRAFT DATA SHOW A RATHER BROAD AREA OF LIGHT WINDS NEAR THE

CENTER, MAKING THE ACTUAL CENTER FIXES A LITTLE UNCERTAIN.

HOWEVER, THE BEST ESTIMATE OF INITIAL MOTION IS NORTH-NORTHEASTWARD

OR 030/6 KT.  A DEVELOPING MID-LEVEL TROUGH OVER THE SOUTHEASTERN

UNITED STATES SHOULD CAUSE HERMINE TO MOVE NORTH-NORTHEASTWARD AT

INCREASING FORWARD SPEED OVER THE NEXT COUPLE OF DAYS.  THE GFS AND

ECMWF GLOBAL MODELS HAVE SHIFTED WESTWARD FROM THEIR PREVIOUS=