TD 07W is forecast to reach Tropical Storm intensity within 24hours/ Invest 97W still under watch// North Altantic: 05L(ELSA) South of Cuba, 05/03utc updates

TD 07W. WARNING 2 ISSUED AT 05/03UTC.SIGNIFICANT FORECAST CHANGES: DUE TO THE INCREASE IN FORWARD SPEED OVER THE PAST FEW HOURS, THE TIME OF LANDFALL HAS MOVED FORWARD SIGNIFICANTLY AND THE PEAK INTENSITY HAS ALSO BEEN LOWERED 15 KNOTS. FORECAST DISCUSSION: TROPICAL DEPRESSION 07W (SEVEN) WILL CONTINUE RAPIDLY TRACK NORTHWEST THROUGH THE NEXT 12 HOURS ALONG THE SOUTHWESTERN PERIPHERY OF THE STEERING SUBTROPICAL RIDGE TO THE NORTHEAST. FORWARD MOTION IS EXPECTED TO REMAIN ABOVE 35 KM/H THROUGH 12H, BUT SLOW THEREAFTER AS THE STEERING FLOW SLACKENS AS THE SYSTEM MOVES SOUTHWEST OF TAIWAN. THE TIMING OF LANDFALL ALONG THE COAST OF SOUTHEASTERN CHINA HAS MOVED UP SIGNIFICANTLY IN RESPONSE TO THE FASTER INITIAL MOTION VECTOR, AND IS NOW EXPECTED AT OR BEFORE 36H. ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN MARGINALLY FAVORABLE FOR CONTINUED DEVELOPMENT THROUGH 24H WITH WARM (30-31C) SSTS, AND LOW TO MODERATE VERTICAL WIND SHEAR. HOWEVER THE UPPER-LEVEL OUTFLOW IS FORECAST TO DEGRADE TO A SINGLE WESTWARD CHANNEL, AND THE CONTINUED FAST FORWARD MOTION WILL SERVE TO INHIBIT THE CONSOLIDATION AND EXPANSION OF THE CORE ON THE WESTERN SIDE. THUS TD 07W IS FORECAST TO CONTINUE TO INTENSIFY BUT AT A MUCH SLOWER RATE THAN THE PREVIOUS FORECAST, WITH A PEAK OF 40 KNOTS NOW EXPECTED AROUND 24H. ONCE INLAND OVER SOUTHEASTERN CHINA, THE SYSTEM WILL RAPIDLY WEAKEN AND DISSIPATE BY 48H.

SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SUGGESTS THAT THE OVERALL CIRCULATION ASSOCIATED WITH TD 07W HAS IMPROVED SLIGHTLY. LOW-LEVEL CURVED BANDS ARE NOW CLEARLY EVIDENT IN THE SOUTHERN SECTOR, WRAPPING INTO A VERY COMPACT LOW LEVEL CIRCULATION CENTER (LLCC), INDICATING THAT A DISTINCT CLOSED LLCC HAS PINCHED OFF FROM THE LARGER TROUGH IN WHICH TD 07W WAS PREVIOUSLY EMBEDDED. FROM A CONVECTIVE STANDPOINT HOWEVER, THE SYSTEM REMAINS DISORGANIZED, WITH CONVECTION FLARING ALONG THE FEEDER BANDS BUT FAILING TO MAINTAIN ITSELF OVER OR NEAR THE CORE. THE SYSTEM HAS SPED UP SIGNIFICANTLY OVER THE PAST FEW HOURS, NOW MOVING AT LEAST 41 KM/H TOWARDS THE NORTHWEST, ALONG A TIGHTENED GRADIENT ON THE SOUTHWESTERN PERIPHERY OF A DEEP SUBTROPICAL RIDGE TO THE NORTHEAST. THE INITIAL POSITION WAS PLACED WITH MODERATE CONFIDENCE INITIALLY BUT LATE RECEIPT OF A 050023Z ASCAT-A PASS PROVIDES HIGH CONFIDENCE TO THE POSITION. THE INITIAL INTENSITY IS ASSESSED WITH MODERATE CONFIDENCE BASED ON A T2.0 (30 KTS) DVORAK INTENSITY ESTIMATE FROM KNES AND THE PREVIOUSLY MENTIONED ASCAT-A PASS, WHICH DOES SHOW A SLIGHT FURTHERANCE OF THE WRAP IN THE WIND FIELD IN THE NORTHERN QUADRANT, AND A PATCH OF 30 KNOT WINDS IN THE NORTHEAST THROUGH SOUTHEAST QUADRANTS.

TD 07W.MODEL DISCUSSION: NUMBERICAL MODEL GUIDANCE REMAINS GOOD AGREEMENT ON THE OVERALL SCENARIO BUT SHOWS INCREASED UNCERTAINY COMPARED WITH THE PREVIOUS FORECAST. THE HWRF AND NAVGEM REMAIN THE RIGHT SIDE (DOWN TRACK) OUTLIERS, TAKING THE SYSTEM OVER TAIWAN, WHILE THE ECMWF AND ECMWF ENSEMBLE ARE THE LEFTMOST OUTLIERS. SPREAD BETWEEN OUTLIERS IS 280 KM AT 24H INCREASING TO 530 KM BY 36H. THE STRENGTHENING OF THE LOW TO MID-LEVEL RIDGE INTO CENTRAL CHINA AFTER 12H SHOULD RESULT IN A SLIGHTLY MORE WESTWARD TRACK, WHICH IS REFLECTED IN THE OFFICIAL FORECAST. THE NVGM AND HWRF SOLUTIONS TAKE THE SYSTEM UNREALISTICALLY INTO THE TEETH OF THE RIDGE TO THE NORTH AND ARE DEEMED UNLIKELY SOLUTIONS. THE JTWC FORECAST LIES ON THE RIGHT EDGE OF THE TIGHTEST GROUPING OF THE CONSENSUS MEMBERS THROUGH LANDFALL. INTENSITY GUIDANCE HAS SHIFTED DRAMATICALLY DOWNWARD SINCE THE PREVIOUS FORECAST, WITH ALL AVAILABLE GUIDANCE MAINTAINING PEAK INTENSITY AT OR BELOW 40 KNOTS. THE JTWC FORECAST REMAINS ABOVE THE INTENSITY CONSENSUS AND NEAR THE GFS SOLUTION.

INVEST 97W. NUMERICAL MODELS ARE IN GENERAL AGREEMENT THAT 97W WILL TRACK NORTHWESTWARD BUT ARE SPLIT REGARDING INTENSIFICATION, WITH ECMWF DETERMINISTIC MODEL, THE ECMWF ENSEMBLE, AND NAVGEM SHOWING DEVELOPMENT IN THE NEXT TWO TO THREE DAYS WHILE THE GFS AND JGSM ARE BELOW WARNING CRITERIA.

JTWC IS ISSUING 6HOURLY WARNINGS AND 3HOURLY SATELLITE BULLETINS ON TD 07W. INVEST 97W IS STILL MEDIUM.

05/00UTC.

NORTH ATLANTIC. TS 05L(ELSA). WARNING 19 ISSUED AT 05/03UTC.TRACKING SOUTH OF CUBA WHILE INTENSIFYING SLIGHTLY TO 60KNOTS WITHIN 12H.

05L(ELSA). GUIDANCE.

05/00UTC.