TC 22S(HALIMA): CAT 1 US, forecast to weaken mainly after 24hours//Remnants of TC 21S(CHARLOTTE):extratropical,27/03utc

JTWC IS ISSUING 12HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TC 22S(HALIMA).

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC HALIMA WILL CONTINUE TO TRACK SOUTHEASTWARD UNDER THE STEERING INFLUENCE OF THE NER. AFTER 24H, THE SYSTEM WILL TRACK MORE EASTWARD AS THE NEAR EQUATORIAL RIDGE (NER) EXTENDS WESTWARD AND IMPEDE THE OVERALL SPEED OF MOTION FOR TC 22S. NEARING 48H, A SUBTROPICAL RIDGE TO THE SOUTHWEST WILL ASSUME STEERING AS IT BUILDS AND DRIVES A SHALLOWER AND WEAKER TC HALIMA NORTHWARD, THEN NORTHWESTWARD BY 60H. THE INCREASING VWS WILL BE RESPONSIBLE FOR THE GRADUAL WEAKENING OF THE SYSTEM, DESPITE POLEWARD VENTING AWAY FROM THE SYSTEM. A SLIGHT COOLING TO THE SSTS AND INCREASED DRY AIR INTRUSION BY TAU 60 WILL CONTRIBUTE TO FURTHER WEAKENING, WHICH WILL ENHANCE DISSIPATION THROUGH 96H.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A MEDIUM-SIZED SYSTEM, WITH FLARING CONVECTION ON THE WESTERN AND EASTERN SIDES OF THE LOW-LEVEL CIRCULATION (LLC). DRY AIR ENTRAINMENT ON THE NORTHERN SECTOR IS WEAKENING THE SYSTEM AS IT CONTINUES TRACKING SOUTHEAST, AS EVIDENCED BY THE MIMIC-TOTAL PRECIPITABLE WATER (TPW) LOOP AND THE EIR LOOP. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON A LARGE MICROWAVE EYE FEATURE IN BOTH THE 262324Z SSMIS 37GHZ AND 91GHZ IMAGES. THE INITIAL INTENSITY IS SET WITH HIGH CONFIDENCE BASED ON AN OVERALL ASSESSMENT FROM MULTIPLE AGENCIES AND AUTOMATED DVORAK ESTIMATES (SHOWN BELOW), WHICH CONTINUE SHOWING THE DETERIORATING TREND. OVER THE LAST TWELVE HOURS, LITTLE HAS HELPED ENHANCE TC HALIMA WITHIN THE ENVIRONMENT, WITH WARM SST AND STRONG POLEWARD OUTFLOW OFFSET BY INCREASING VERTICAL WIND SHEAR. THE CYCLONE IS TRACKING ALONG THE SOUTHWEST PERIPHERY OF A DEEP-LAYERED NER TO THE NORTHEAST.

MODEL DISCUSSION: NUMERICAL MODELS ARE IN OVERALL FAIR AGREEMENT UP TO 48H. BY 96H, A BIFURCATION SETS UP WITHIN THE DETERMINISTIC AND ENSEMBLE MODELS. GFS (AVNI, AEMI) AND ECMWF (ECM2, EEM2) TURN THE SYSTEM EQUATORWARD AS THE NER REMAINS THE MAIN STEERING MECHANISM, AND UKMET (EGRI, UEMI) TURNS IT POLEWARD WITH THE STEERING FROM THE STR TO THE SOUTH. THE DETERMINISTIC NAVGEM AND AFUM INDICATE A POLEWARD VORTEX TRAJECTORY. BECAUSE OF THIS, THERE IS MEDIUM CONFIDENCE IN THE JTWC TRACK AND INTENSITY FORECAST UP TO 48H, THEN LOW CONFIDENCE AFTERWARD.