[JTWC] Summary: TROPICAL CYCLONE (TC) 06P (ULA), LOCATED APPROXIMATELY 190 NM SOUTH-SOUTHWEST OF PAGO PAGO, AMERICAN SAMOA HAS TRACKED SOUTHWESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A SLIGHTLY ELONGATED CENTRAL DENSE OVERCAST FEATURE OBSCURING THE LOW LEVEL CIRCULATION CENTER. THE CURRENT POSITION IS PLACED WITH FAIR CONFIDENCE BASED ON LOW REFLECTIVITY BANDING SEEN IN A 010623Z SSMIS 91GHZ MICROWAVE IMAGE AND IS SUPPORTED BY AGENCY SATELLITE FIXES. THE MICROWAVE IMAGE SHOWS AN UNORGANIZED CONVECTIVE STRUCTURE WITH THE BULK OF CONVECTION NOW LOCATE ALONG THE SOUTHERN SEMI-CIRCLE. THE CURRENT INTENSITY HAS BEEN HELD AT 90 KNOTS BASED ON CURRENT INTENSITY ESTIMATES OF T5.0 (90 KNOTS) FROM PGTW AND KNES. THE UPPER LEVEL ENVIRONMENT REMAINS MOSTLY FAVORABLE WITH LOW VERTICAL WIND SHEAR (VWS) AND STRONG DIVERGENCE; HOWEVER, THE SYSTEM IS STRUGGLING AS SIGNIFICANT DRY AIR TO THE SOUTH IS APPLYING PRESSURE AGAINST THE SYSTEM AND ELONGATING THE MOISTURE FIELD. THIS IS EVIDENT IN THE TOTAL PRECIPITABLE WATER LOOP. TC ULA CONTINUES TO TRACK ALONG THE NORTHERN PERIPHERY OF THE DEEP-LAYERED SUB-TROPICAL RIDGE TO THE SOUTH. GIVEN THE CURRENT ENVIRONMENT, THE CYCLONE HAS THE POTENTIAL TO INTENSIFY AS IT TRACKS FURTHER WESTWARD; HOWEVER, VWS WILL QUICKLY BEGIN TO INCREASE AND THE SYSTEM WILL TURN POLEWARD INTO COLDER WATER. THESE FACTORS WILL START A WEAKENING TREND AND LEAD TO FULL DISSIPATION BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE HAS COME INTO TIGHTER AGREEMENT ON THE AFOREMENTIONED TRACK SCENARIO WHICH LEADS TO HIGH CONFIDENCE IN THE JTWC FORECAST. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 010600Z IS 27 FEET. NEXT WARNINGS AT 012100Z AND 020900Z.