WTNT41 KNHC 220842 RRA

TCDAT1



TROPICAL DEPRESSION FIONA DISCUSSION NUMBER  22

NWS NATIONAL HURRICANE CENTER MIAMI FL       AL062016

500 AM AST MON AUG 22 2016



ALTHOUGH DEEP CONVECTION HAS CONTINUED TO PULSE NEAR THE CENTER OF

FIONA, RECENT SCATTEROMETER WIND DATA AND VARIOUS SATELLITE

CLASSIFICATIONS SUPPORT MAINTAINING THE SMALL BUT REMARKABLY

RESILIENT CYCLONE AS A 30-KT TROPICAL DEPRESSION. THE INTENSITY

FORECAST STILL REMAINS SOMETHING OF AN ENIGMA. STRONG WESTERLY WIND

SHEAR IS FORECAST TO PERSIST FOR THE NEXT 12-18 HOURS, AFTER WHICH

THE UPPER-LEVEL WINDS RELAX SOMEWHAT AND BECOME A LITTLE MORE

CONDUCIVE FOR STRENGTHENING TO OCCUR. HOWEVER, DRY MID-LEVEL

AIR OF 40-50 PERCENT HUMIDITY IS ALSO FORECAST TO SURROUND THE

CYCLONE, WHICH COULD ACT TO HINDER THE DEVELOPMENT OF PERSISTENT

DEEP CONVECTION FOR THE NEXT 24-36 HOURS. THEREFORE, IF FIONA

CAN SURVIVE THE AFOREMENTIONED HOSTILE CONDITIONS DURING THE NEXT 24

HOURS OR SO, THEN SOME RESTRENGTHENING OR MAINTAINING THE STATUS AS

A TROPICAL CYCLONE IS POSSIBLE.  THE GLOBAL MODELS STILL DISAGREE ON

THE FUTURE OF FIONA AND HAVE FLIPPED-FLOPPED, WITH THE ECMWF NO

LONGER SHOWING DISSIPATION IN 5 DAYS, WHICH IS SIMILAR TO THE UKMET

SOLUTION, WHEREAS THE GFS NOW SHOWS FIONA DEGENERATING INTO AN OPEN

TROUGH BETWEEN 96-120 HOURS. THE NHC FORECAST MAINTAINS CONTINUITY

AND INDICATES DISSIPATION IN 5 DAYS AS A COMPROMISE BETWEEN THESE

POSSIBILITIES.



THE INITIAL MOTION ESTIMATE REMAINS 290/16 KT. ALTHOUGH THERE IS

UNCERTAINTY IN THE FUTURE STATUS OF FIONA, THE NHC MODEL GUIDANCE

IS IN PRETTY GOOD AGREEMENT ON THE TRACK OF THE CYCLONE FOR THE

NEXT 72 HOURS. THE SMALL CYCLONE IS FORECAST TO MOVE QUICKLY=