WTNT42 KNHC 231445 RRA

TCDAT2



TROPICAL STORM KARL DISCUSSION NUMBER  37

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122016

ISSUED BY THE NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

1100 AM AST FRI SEP 23 2016



A NOAA P3 FLIGHT CONTINUED TO FLY THROUGH KARL FOR A FEW HOURS

AFTER THE RELEASE OF THE LAST ADVISORY, AND WHILE IT DIDN'T FIND

WINDS HIGHER THAN 50 KT, DROPSONDE DATA DID INDICATE THAT THE

MINIMUM PRESSURE HAD FALLEN TO 992 MB.  MICROWAVE DATA INDICATE

THAT KARL IS STILL UNDER THE INFLUENCE OF 15-20 KT OF SOUTH-

SOUTHEASTERLY SHEAR.  THE CONVECTIVE PATTERN HAS CONTINUED TO

IMPROVE, HOWEVER, WITH AN ELONGATED CURVED BAND EXTENDING TO THE

NORTHEAST AND EAST OF THE CENTRAL CONVECTION.



WITH SEA SURFACE TEMPERATURES RUNNING BETWEEN 29-30C FOR THE NEXT

24 HOURS AND VERTICAL SHEAR EXPECTED TO DECREASE SLIGHTLY, IT SEEMS

LIKELY THAT KARL WILL CONTINUE TO STRENGTHEN DURING THE NEXT COUPLE

OF DAYS.  THE INTENSITY GUIDANCE IS IN FAIRLY GOOD AGREEMENT ON THE

INTENSIFICATION TREND, AND IN FACT MOST OF THE MODELS ARE SHOWING

KARL REACHING A STRENGTH BETWEEN 60 AND 65 KT IN ABOUT 24 HOURS.

THEREFORE, THE UPDATED OFFICIAL FORECAST NOW SHOWS KARL REACHING

HURRICANE INTENSITY AT THAT TIME.  CONTINUED STRENGTHENING IS

LIKELY AFTER THAT TIME, AND THE PEAK INTENSITY SHOWN IN THE

OFFICIAL FORECAST IS SLIGHTLY HIGHER THAN THE PREVIOUS FORECAST AT

48 HOURS, WHICH IS IN LINE WITH THE LATEST GUIDANCE.  KARL WILL BE

IN THE PROCESS OF EXTRATROPICAL TRANSITION AT THAT TIME, BUT THE

GLOBAL MODELS FIELDS ONLY AGREE THAT THE TRANSITION WILL BE

COMPLETE BY 72 HOURS.  KARL SHOULD THEN BE ABSORBED BY A LARGER

EXTRATROPICAL LOW BY DAY 4.=