TS 04W(CHABA), Invest 98W// TC 02L// Invest 94E and Invest 95L: 30/03utc updates

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) LOCATED UNDER THE NORTHERN AREA OF BUILDING CONVECTION IN THE SOUTHERN SEMI-CIRCLE. THE LATEST VISIBLE SATELLITE LOOP INDICATES BUILDING CONVECTION IN THE NORTHEAST QUADRANT, HOWEVER THERE IS EVIDENCE OF SHEAR FROM THE NORTHEAST AS WELL. THE INITIAL POSITION IS PLACED WITH MEDIUM CONFIDENCE BASED OFF THE PGTW FIX AND AFOREMENTIONED VISIBLE SATELLITE LOOP. THE INITIAL INTENSITY OF 35 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON STRUCTURE AND TWO SHIP WEATHER OBSERVATIONS OF 34 KTS AND 35 KTS, BOTH LOCATED SOUTHWEST OF THE LLCC.

FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: INCREASING MAX INTENSITY TO 60 KTS BEGINNING AT TAU 36 THROUGH TAU 48, JUST BEFORE LANDFALL OVER EASTERN HAINAN. FORECAST DISCUSSION: TS CHABA WILL TRACK NORTH-NORTHWESTWARD AND STRENGTHEN TO 55 KTS OVER THE NEXT 24 HOURS. BY TAU 36, THE STR TO THE NORTHEAST WILL BUILD IN CAUSING THE SYSTEM TO SHIFT TO A MORE NORTHWESTWARD TRACK. AT THIS TIME INTENSITY WILL INCREASE TO 60 KTS DUE TO TS CHABA PASSING UNDER AN AREA OF DECREASED VERTICAL WIND SHEAR (5-10KTS) AND KEEP INTENSITY AT 60 KTS BY TAU 48, JUST BEFORE PASSING OVER THE EASTERN PORTION OF THE ISLAND OF HAINAN. BY TAU 72, TS CHABA WILL SUCCUMB TO THE AFFECTS OF LAND INTERACTION BETWEEN HAINAN AND MAINLAND CHINA AND WILL DECREASE IN INTENSITY TO 35 KTS. TAUS 96 AND 120 TAKE THE SYSTEM OVER LAND IN SOUTHERN CHINA WHERE DISSIPATION WILL OCCUR.

MODEL DISCUSSION: THE JTWC MODEL CONSENSUS ENVELOPE REMAINS RELATIVELY TIGHT, WITH THE NAVGEM TRACKER BEING THE OUTLIER PLACED OFF TO THE WEST OF CONSENSUS, THEN CROSSING OVER OFF TO THE EAST OF THE ENVELOPE BY TAU 36. ALSO AT TAU 36, THE JGSM TRACKER SHOOTS OFF TO A MORE NORTHWARD DIRECTION. BECAUSE OF THIS, THE JTWC TRACK IS LAID TO THE LEFT OF CONSENSUS AFTER TAU 48. THERE IS A 25 NM MODEL SPREAD IN TRACK CONSENSUS AT TAU 12, INCREASING TO 50 NM BY TAU 48. AFTER TS CHABA INTERACTS WITH LAND BY TAU 72, THE MODEL SPREAD INCREASES TO 120 NM, LOWERING THE CONFIDENCE IN THE TRACK FORECAST DURING THE LATER PORTION OF THE FORECAST PERIOD. INTENSITY GUIDANCE ALSO IS RELATIVELY UNIFORM. THE JTWC FORECAST INTENSITY IS PLACED WITH MEDIUM CONFIDENCE. ALL AGREE ON INCREASING INTENSITY UP TO TAU 48. AFTERWARDS, THE JTWC INTENSITY IS SET BELOW CONSENSUS TO ACCOUNT FOR A GREAT DEAL OF LAND INTERACTION WITH HAINAN AND MAINLAND CHINA.

THE AREA OF CONVECTION (INVEST 98W) PREVIOUSLY LOCATED NEAR 17.8N 129.2E IS NOW LOCATED NEAR 18.2N 131.4E, APPROXIMATELY 632 NM EAST- NORTHEAST OF MANILA, PHILIPPINES. ENHANCED MULTISPECTRAL SATELLITE IMAGERY AND A 292156Z SSIMIS 91GHZ PASS DEPICTS A CONVECTIVE BANDING OFFSET TO THE SOUTH OF A BROAD, ILL DEFINED LOW LEVEL CIRCULATION (LLC). A TUTT CELL LOCATED SOUTHWEST OF SASEBO, JAPAN HAS TRACKED TO THE WEST WHICH IS INTRODUCING AN AREA OF UPPER LEVEL DIVERGENCE OVER INVEST 98W, FURTHER INCREASING INSTABILITY. ENVIRONMENTAL ANALYSIS INDICATES FAVORABLE CONDITIONS FOR DEVELOPMENT DEFINED BY; MODERATE EQUATORWARD OUTFLOW ALOFT, LOW (10-15KT) VERTICAL WIND SHEAR, AND WARM (30C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN STRONG AGREEMENT THAT 98W WILL TRACK NORTHWESTWARD AS IT BEGINS TO DEVELOP OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.

012 WTNT42 KNHC 300243 TCDAT2 Potential Tropical Cyclone Two Discussion Number 10 NWS National Hurricane Center Miami FL AL022022 1100 PM EDT Wed Jun 29 2022 Last-light visible satellite imagery suggests that the disturbance is gradually developing a closed circulation However, surface observations from the ABC islands, as well as imagery from the Curacao radar, indicate that the center is poorly defined. In addition, the associated convection has become less organized during the past several hours. Based on this, the system will not be upgraded to a tropical storm at this time. The initial intensity remains 35 kt, with these winds most likely occurring over the open Caribbean to the north of the ABC Islands. The initial motion is now 275/18 kt. A large mid-level ridge to the north of the system should steer it generally westward for the next 2-3 days with some decrease in forward speed, with a more west-northwestward motion after the system crosses Central America into the Pacific. The track guidance has nudged a little farther south through the first 60 h or so, so the new forecast track is also nudged a little southward and lies close to the various consensus models. Warm sea surface temperatures, a moist air mass, and light shear should allow the system to develop as it moves away from land later tonight and on Thursday. The current forecast continues to call for the system to become a tropical storm and then be just below hurricane strength as it nears the coast of Nicaragua in about 48 h. Significant weakening should occur over Central America, followed by re-intensification over the eastern Pacific. The new intensity forecast follows the overall trend of the guidance and is similar to the previous forecast.

FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN 140 NM EITHER SIDE OF A LINE FROM 12.1N 103.1W TO 15.5N 113.6W WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME. WINDS IN THE AREA ARE ESTIMATED TO BE 18 TO 23 KNOTS. METSAT IMAGERY AT 300000Z INDICATES THAT A CIRCULATION CENTER IS LOCATED NEAR 12.2N 103.3W. THE SYSTEM IS MOVING WEST-NORTHWESTWARD AT 23 KNOTS. 2. REMARKS: AN AREA OF CONVECTION (INVEST 94E) HAS PERSISTED NEAR 12.2N 103.3W, APPROXIMATELY 741 NM SOUTH-SOUTHEAST OF CABO SAN LUCAS, MEXICO. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) AND A 300000Z SSMIS 91GHZ IMAGE DEPICT A SMALL LOW PRESSURE SYSTEM WITH LOW LEVEL RAIN BANDS WRAPPING INTO A LOW-LEVEL CIRCULATION CENTER. UPPER LEVEL ANALYSIS INDICATES THE DISTURBANCE IS LOCATED IN AN AREA OF FAVORABLE (5-10 KNOTS) VERTICAL WIND SHEAR, GOOD POLEWARD OUTFLOW AND WARM SEA SURFACE TEMPERATURES (28-29C). GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT INVEST 94E WILL TRACK GENERALLY WEST AS IT INTENSIFIES OVER THE EASTERN PACIFIC. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1009 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH.