WTNT44 KNHC 031457 RRA

TCDAT4



POST-TROPICAL CYCLONE HERMINE DISCUSSION NUMBER  25

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092016

1100 AM EDT SAT SEP 03 2016



SATELLITE IMAGERY INDICATES THAT HERMINE HAS BECOME A POST-TROPICAL

CYCLONE, WITH THE COLDEST CONVECTIVE TOPS NOW LOCATED MORE THAN 200

N MI NORTHEAST OF THE EXPOSED CENTER.  DESPITE THIS CHANGE IN

STRUCTURE, SURFACE DATA FROM THE OUTER BANKS INDICATE THAT SOME

STRONG WINDS PERSIST NEAR THE CENTER, AND THE INITIAL INTENSITY IS

SET TO 55 KT FOR THIS ADVISORY.  DURING THE NEXT 48 TO 72 HOURS,

HERMINE WILL INTERACT WITH A STRONG MID-LATITUDE SHORTWAVE TROUGH

AND ALL OF THE GLOBAL MODELS SHOW THE SYSTEM RE-INTENSIFYING DURING

THAT TIME AND A REDEVELOPMENT OF A STRONGER INNER CORE, ALBEIT ONE

SITUATED UNDERNEATH AN UPPER-LEVEL LOW. REGARDLESS OF ITS FINAL

STRUCTURE, HERMINE IS EXPECTED TO REMAIN A DANGEROUS CYCLONE THROUGH

THE 5 DAY PERIOD.



THE INITIAL MOTION ESTIMATE IS A SOMEWHAT UNCERTAIN 060/14.  HERMINE

SHOULD CONTINUE MOVING NORTHEASTWARD IN DEEP-LAYER SOUTHWESTERLY

FLOW THROUGH 24 HOURS AND THEN MEANDER GENERALLY NORTHWARD FROM 36

TO 72 HOURS WHILE THE CYCLONE DEEPENS BENEATH THE UPPER-LEVEL LOW.

LATE IN THE PERIOD, THE GUIDANCE IS IN GENERALLY GOOD AGREEMENT

SHOWING A STEADIER MOTION TOWARD THE NORTHEAST, ALTHOUGH THERE IS

SIGNIFICANT SPREAD.  THE NEW NHC FORECAST IS GENERALLY CLOSE TO THE

PREVIOUS ONE AND IS NEAR A CONSENSUS OF THE GFS AND ECMWF THROUGH 3

DAYS, AND THEN FAVORS THE GUIDANCE THAT IS A BIT FASTER AND FARTHER

NORTH AT DAYS 4 AND 5.





KEY MESSAGES:



1. THE SLOW MOTION AND LARGE WIND FIELD ASSOCIATED WITH HERMINE WILL

RESULT IN A LONG DURATION OF HAZARDOUS CONDITIONS ALONG MUCH OF THE=