WTNT44 KNHC 021455 RRA

TCDAT4



TROPICAL STORM HERMINE DISCUSSION NUMBER  21

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092016

1100 AM EDT FRI SEP 02 2016



HERMINE IS MOVING OVER SOUTHEASTERN GEORGIA AND HAS WEAKENED

STEADILY SINCE LANDFALL.  CONVECTIVE TOPS HAVE WARMED, BUT SEVERAL

LAND STATIONS HAVE SHOWN SUSTAINED WINDS NEAR TROPICAL STORM FORCE

NEAR THE CENTER WITH SOME GUSTS CLOSE TO 50 KT.  STRONGER WINDS ARE

ALSO FOUND OVER THE ATLANTIC COASTAL WATERS, WITH BUOY 41008

REPORTING WINDS AROUND 40 KT IN THE LAST HOUR.  BASED ON THIS, THE

INITIAL INTENSITY IS SET TO 45 KT FOR THIS ADVISORY.  THE CENTRAL

PRESSURE, BASED ON SURFACE DATA, IS ABOUT 989 MB.  WHILE THE CENTER

OF HERMINE WILL REMAIN OVER LAND FOR THE NEXT 24 HOURS OR SO, I

DON'T EXPECT THE WINDS OVER WATER TO DECREASE MUCH, SO THE NHC

FORECAST SHOWS NO CHANGE DURING THAT TIME.  STRENGTHENING THROUGH A

COMBINATION OF DIABATIC AND BAROCLINIC PROCESSES IS SHOWN AFTER THE

SYSTEM MOVES OFFSHORE.  THE GFS, ECMWF, AND UKMET ALL SHOW HERMINE

INTERACTING WITH A POTENT UPPER-LEVEL SHORTWAVE TROUGH IN 2-3 DAYS,

AND THE SYSTEM COULD RE-STRENGTHEN TO NEAR HURRICANE FORCE AT THAT

TIME.  SLOW WEAKENING IS EXPECTED LATER IN THE PERIOD, BUT HERMINE

IS EXPECTED TO REMAIN A DANGEROUS CYCLONE THROUGH 5 DAYS.  THE NHC

INTENSITY FORECAST IS BASED LARGELY ON GLOBAL MODEL GUIDANCE, AND IS

A BIT HIGHER THAN THE PREVIOUS ONE.



THE INITIAL MOTION ESTIMATE IS 040/16.  HERMINE SHOULD CONTINUE

MOVING NORTHEASTWARD FOR THE NEXT 36 TO 48 HOURS AHEAD OF AN

APPROACHING MID-LATITUDE TROUGH.  AFTER THAT TIME, THE CYCLONE

SHOULD TURN NORTHWARD AND NEARLY STALL OUT AS IT INTERACTS WITH THE=