WTNT42 KNHC 202044 RRA

TCDAT2



TROPICAL STORM KARL DISCUSSION NUMBER  26

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL122016

ISSUED BY THE NWS WEATHER PREDICTION CENTER COLLEGE PARK MD

500 PM AST TUE SEP 20 2016



KARL'S CENTER HAD LOST SOME DEFINITION THROUGHOUT THE DAY, BUT DEEP

CONVECTION HAS REDEVELOPED NEAR THE CENTER LATE IN THE AFTERNOON.

DVORAK CURRENT INTENSITY ESTIMATES WERE LOWERED TO 2.5 FROM TAFB AND

2.0 FROM SAB, AND THE LATEST UW-CIMSS ADT ESTIMATE IS T3.2. A NOAA

P-3 FLIGHT CURRENTLY CONDUCTING A RESEARCH MISSION INTO KARL HAS

NOT YET FOUND TROPICAL-STORM-FORCE WINDS, BUT IT HAS NOT SAMPLED

THE ENTIRE CIRCULATION YET. THE INITIAL INTENSITY IS THEREFORE HELD

AT 35 KT PENDING ADDITIONAL DATA FROM THE P-3. THE MINIMUM PRESSURE

IS LOWERED TO 1005 MB BASED ON DROPSONDE DATA FROM THE NOAA G-IV

JET, WHICH IS ALSO FLYING NEAR KARL.



LITTLE TO NO CHANGE IS EXPECTED IN THE STRENGTH OF KARL OVER THE

NEXT 24 HOURS AS THE INFLUENCE OF AN UPPER LOW CONTINUES TO SHEAR

OUT THE WESTERN SIDE OF THE STORM. THE GLOBAL MODELS INDICATE THAT

THE SHEAR SHOULD RELAX IN THE NEXT 24 TO 36 HOURS ALLOWING A SLIGHT

STRENGTHENING IN THAT PERIOD. AS KARL ROUNDS THE MID-LEVEL RIDGE

IT WILL FIND ITSELF IN A MORE FAVORABLE ENVIRONMENT WITH WARM

SSTS AND LOWER SHEAR. AN INCREASED RATE OF INTENSIFICATION SHOULD

TAKE PLACE IN THE 48 TO 72 HOUR TIME FRAME, AND KARL IS EXPECTED TO

REACH HURRICANE STRENGTH BY THE END OF THAT PERIOD. THE OFFICIAL

INTENSITY FORECAST HAS BEEN NUDGED SLIGHTLY DOWNWARD BASED ON THE

LATEST GUIDANCE, HOWEVER IT IS STILL ON THE UPPER END OF THE

GUIDANCE SPREAD.



THE CENTER OF KARL CONTINUES PUSHING WEST NEAR THE 20TH PARALLEL=