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WTXS31 PGTW 011500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04S (ALVARO) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 04S (ALVARO) WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 011200Z --- NEAR 21.5S 42.7E MOVEMENT PAST SIX HOURS - 105 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 075 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT REPEAT POSIT: 21.5S 42.7E --- FORECASTS: 12 HRS, VALID AT: 020000Z --- 21.7S 44.6E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 24 HR POSIT: 095 DEG/ 10 KTS --- 24 HRS, VALID AT: 021200Z --- 21.8S 46.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 36 HR POSIT: 095 DEG/ 08 KTS --- 36 HRS, VALID AT: 030000Z --- 22.0S 48.6E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 48 HR POSIT: 110 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 031200Z --- 22.6S 50.2E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 125 DEG/ 10 KTS --- 72 HRS, VALID AT: 041200Z --- 24.9S 53.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 120 DEG/ 11 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 051200Z --- 26.9S 58.0E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 011500Z POSITION NEAR 21.6S 43.2E. 01JAN24. TROPICAL CYCLONE 04S (ALVARO), LOCATED APPROXIMATELY 145 NM EAST-NORTHEAST OF EUROPA ISLAND, HAS TRACKED EAST- SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 011200Z IS 989 MB. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 011200Z IS 19 FEET. NEXT WARNINGS AT 020300Z AND 021500Z.// NNNN
WDXS31 PGTW 011500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04S (ALVARO) WARNING NR 003// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 21.5S 42.7E INITIAL INTENSITY: 60 KTS GEOGRAPHIC REFERENCE: 145 NM EAST-NORTHEAST OF EUROPA ISLAND MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 09 KTS SIGNIFICANT WAVE HEIGHT: 19 FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: TROPICAL CYCLONE (TC) 04S HAS CONSOLIDATED STEADILY OVER THE PAST 12 HOURS, FLIRTING WITH A RAGGED, FORMATIVE EYE AT TIMES. RECENT ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A CENTRAL DENSE OVERCAST BUILDING OVER AND OBSCURING THE CENTER. FORTUNATELY, A 011026Z AMSR2 37 GHZ COLOR COMPOSITE MICROWAVE IMAGE DEPICTS A CYAN RING SURROUNDING A ROUND, WELL-DEFINED MICROWAVE EYE FEATURE, WHICH SUPPORTS THE INITIAL POSITION WITH HIGH CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 60 KNOTS BASED ON AN AVERAGE OF THE SUBJECTIVE DVORAK ESTIMATES (55-65 KNOTS) AND A 011029Z DMINT ESTIMATE OF 57 KNOTS. ADDITIONALLY, A 010253Z SENTINEL-1A SAR PASS INDICATED MAXIMUM WINDS OF 59 KNOTS AND A 011026Z AMSR2 WINDSPEED IMAGE REVEALED A SWATH OF 50-62 KNOTS WINDS OVER THE EASTERN SEMICIRCLE WITH SOME HIGHER WINDS ALONG THE COAST. THE INITIAL INTENSITY ASSESSMENT IS CONSISTENT WITH THE STRONG MICROWAVE EYE FEATURE AND SHORT-LIVED VISIBLE EYE. INITIAL WIND RADII BASIS: OBJECTIVE BEST TRACK CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE POSITIONED TO THE NORTH STEERING THE SYSTEM GENERALLY EASTWARD. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: T3.5 - 55 KTS KNES: T4.0 - 65 KTS FMEE: T4.0 - 65 KTS CIMSS SATCON: 45 KTS AT 011230Z CIMSS ADT: 49 KTS AT 011200Z CIMSS DMINT: 57 KTS AT 011029Z FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: FAVORABLE VWS: 10-15 KTS SST: 29-30 CELSIUS OUTFLOW: STRONG POLEWARD OTHER FACTORS: MID- TO UPPER-LEVEL DRY AIR ENTRAINMENT ANALYSIS CONFIDENCE: INITIAL POSITION: HIGH INITIAL INTENSITY: MEDIUM INITIAL WIND RADII: LOW 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: DUE TO RAPID CONSOLIDATION OF THE SYSTEM'S CORE, THE INITIAL INTENSITY IS SIGNIFICANTLY HIGHER THAN THE PREVIOUS JTWC WARNING. ADDITIONALLY, INITIAL INTENSITIES FROM 311800Z TO 010600Z HAVE BEEN RE-EVALUATED AND REVISED HIGHER. FORECAST DISCUSSION: TC 04S IS FORECAST TO WEAKEN AS IT TRACKS EASTWARD AND APPROACHES THE COAST OF MADAGASCAR, WITH LANDFALL ANTICIPATED NEAR TAU 06. AFTER TAU 06, THE SYSTEM WILL WEAKEN RAPIDLY AND DISSIPATE AS IT TRACKS EASTWARD ACROSS THE MOUNTAINOUS TERRAIN OF SOUTHERN MADAGASCAR. TC 04S WILL RE-EMERGE OVER THE INDIAN OCEAN NEAR TAU 36 WITH A BRIEF PERIOD OF REINTENSIFICATION TO ABOUT 40 KNOTS BY TAU 48. AFTER TAU 48, TC 04S WILL TURN EAST-SOUTHEASTWARD AS IT TRANSITIONS TO THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE POSITIONED TO THE NORTHEAST. THE SYSTEM IS EXPECTED TO WEAKEN STEADILY AS IT INTERACTS WITH STRENGTHENING SUBTROPICAL WESTERLIES AND ENCOUNTERS STRONG VERTICAL WIND SHEAR (40 TO 55 KNOTS) AND COOLING SEA SURFACE TEMPERATURES (26 TO 25 C). TC 04S WILL DISSIPATE NO LATER THAN TAU 96. MODEL DISCUSSION: NUMERICAL MODEL GUIDANCE IS IN FAIR AGREEMENT LENDING MEDIUM CONFIDENCE TO THE JTWC TRACK FORECAST THROUGH TAU 96. THE 010000Z ECMWF ENSEMBLE (EPS) AND THE 010600Z GFS ENSEMBLE (GEFS) GENERALLY INDICATE A LOW TO MODERATE PROBABILITY OF REINTENSIFICATION TO 35-49 KNOTS EAST OF MADAGASCAR. HOWEVER, THERE IS HIGH UNCERTAINTY DUE TO THE MARGINAL CONDITIONS FORECAST DURING THIS PHASE OF THE JTWC FORECAST. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
最后于 2024-01-02 04:25:00 被ygsj24编辑 ，原因： -
WTIO30 FMEE 011929 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 12/1/20232024 1.A SEVERE TROPICAL STORM 1 (ALVARO) 2.A POSITION 2024/01/01 AT 1800 UTC: WITHIN 20 NM RADIUS OF POINT 21.4 S / 43.9 E (TWENTY ONE DECIMAL FOUR DEGREES SOUTH AND FORTY THREE DECIMAL NINE DEGREES EAST) MOVEMENT: EAST 9 KT 3.A DVORAK ANALYSIS: NIL 4.A CENTRAL PRESSURE: 989 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 50 KT RADIUS OF MAXIMUM WINDS (RMW): 35 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 95 SE: 95 SW: 175 NW: 155 34 KT NE: 0 SE: 35 SW: 130 NW: 110 48 KT NE: 0 SE: 0 SW: 0 NW: 85 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 900 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS (WINDS RADII IN KM): 12H: 2024/01/02 06 UTC: 21.5 S / 45.6 E, VENT MAX= 030 KT, OVERLAND DEPRESSION 28 KT NE: 0 SE: 130 SW: 150 NW: 0 24H: 2024/01/02 18 UTC: 21.6 S / 47.7 E, VENT MAX= 025 KT, OVERLAND DEPRESSION 36H: 2024/01/03 06 UTC: 22.0 S / 49.3 E, VENT MAX= 035 KT, MODERATE TROPICAL STORM 28 KT NE: 110 SE: 165 SW: 150 NW: 100 34 KT NE: 0 SE: 100 SW: 0 NW: 0 48H: 2024/01/03 18 UTC: 23.1 S / 51.0 E, VENT MAX= 040 KT, MODERATE TROPICAL STORM 28 KT NE: 0 SE: 130 SW: 110 NW: 0 34 KT NE: 0 SE: 85 SW: 0 NW: 0 60H: 2024/01/04 06 UTC: 24.3 S / 52.9 E, VENT MAX= 030 KT, POST-TROPICAL DEPRESSION 28 KT NE: 120 SE: 130 SW: 0 NW: 0 72H: 2024/01/04 18 UTC: 25.2 S / 54.7 E, VENT MAX= 025 KT, FILLING UP 2.B LONGER-RANGE OUTLOOK: NIL 2.C ADDITIONAL INFORMATION: ***HAPPY NEW YEAR 2024 FROM RSMC LA REUNION*** T=CI=/ ALVARO REACHED THE WEST COAST OF MADAGASCAR, CLOSE TO MOROMBE (TULEAR PROVINCE) AT AROUND 16Z. SINCE 12Z, ALVARO'S CLOUD PATTERN HAS GRADUALLY DETERIORATED AS IT APPROACHED THE MALAGASY MAINLAND, BUT ALSO DUE TO PERSISTENT AND SUSTAINED MID-TROPOSPHERIC WESTERLY SHEAR ACCORDING TO THE LATEST CIMSS DATA, AND THE LATEST WATER VAPOR IMAGES SHOWING AN ARC OF SHEAR IN THE WESTERN SEMICIRCLE. THE CLOUD TOPS GRADUALLY WARMED UP, AND THE CHALKY EYE OBSERVED THIS AFTERNOON GRADUALLY DISAPPEARED BENEATH THE MAIN CONVECTION A LITTLE BEFORE 13Z. HOWEVER, A SKETCH OF AN EYE REAPPEARED SURREPTITIOUSLY AROUND 17Z, PROVIDING FAIRLY RELIABLE DATA FOR THE OBSERVATION POINT AND STILL SUGGESTING HIGH INTENSITY. THE LATEST SSMIS F-16 AND SSMIS F-17 IMAGES FROM 1516Z AND 1608Z SUPPORT THIS VIEW AND STILL SHOWED A SOLID, WELL-CONSTITUTED 89 GHZ HOT CORE. THE FINAL INTENSITY WAS RAISED TO 50KT IN THE LIGHT OF THESE ELEMENTS AND THE LATEST OBJECTIVE AND SUBJECTIVE DATA. NO CHANGE IN TERMS OF TRAJECTORY, ALVARO IS FOLLOWING THE WESTERLY FLOW DRIVEN BY A NEAR-EQUATORIAL RIDGE LOCATED FURTHER NORTH AND A WEAK TROUGH PASSING FURTHER SOUTH. AFTER CROSSING THE MADAGASCAN MAINLAND ON TUESDAY, THE VORTEX SHOULD EMERGE OVER THE EAST COAST OF MADAGASCAR IN THE MANAKARA SECTOR (FIANARANTSOA PROVINCE) ON TUESDAY NIGHT. IT SHOULD BE NOTED THAT THERE IS STILL SOME UNCERTAINTY AS TO THE SPEED AT WHICH ALVARO WILL MOVE OVER LAND, LEAVING CONSIDERABLE UNCERTAINTY AS TO THE TIMING OF ITS EMERGENCE AT SEA. THEREAFTER, GUIDED BY THE RIDGE OF HIGH PRESSURE FORTIFYING ITSELF OVER THE NORTHERN MASCARENE ISLANDS AND BY THE FLOW FURTHER SOUTH, ALVARO WILL CONTINUE ITS COURSE IN A GENERAL SOUTH-EASTERLY DIRECTION, BRINGING IT UNDER INCREASINGLY UNFAVORABLE ENVIRONMENTAL CONDITIONS, WITHIN WHICH THE SYSTEM WILL GRADUALLY LOSE ITS PURELY TROPICAL CHARACTERISTICS. DUE TO ITS MARKED INTERACTION WITH THE MALAGASY LANDS, ALVARO HAS ABRUPTLY LEFT THE WARM WATERS OF THE MOZAMBIQUE CHANNEL, ALONG THE TULEAR PROVINCE. MOREOVER, THE SHEAR IS SET TO CONTINUE UNDERMINING THE SYSTEM TO SOME EXTENT. IN SPITE OF EVERYTHING, CONVECTIVE ACTIVITY SHOULD REMAIN HIGH DUE TO INERTIA. THE VORTEX SHOULD RECONSOLIDATE LATE ON TUESDAY NIGHT AND EMERGE TO THE EAST OF MADAGASCAR, THANKS TO GOOD SURFACE LOW LEVEL CONVERGENCE AND A TEMPORARY RETURN TO COASTAL WARMTH. THIS POTENTIAL FOR REINTENSIFICATION COULD BE REDUCED IF THE VORTEX WEAKENS MORE MARKEDLY AS IT CROSSES MADAGASCAR. IN THE CASE OF THE CURRENT FORECAST, REINTENSIFICATION IS THEN POSSIBLE FOR ALMOST 24 HOURS, BUT THE INCREASE IN SHEAR AND THE INTRUSION OF DRY AIR FROM THE NORTH-WESTERN SECTOR OF THE SYSTEM SHOULD THEN CONTINUALLY WEAKEN ALVARO FROM WEDNESDAY EVENING. IMPACTS ON MADAGASCAR (BY DEFAULT, THE CHRONOLOGY OF EVENTS IS GIVEN IN UTC): - GALE FORCE TO STRONG GALE FORCE WINDS CURRENTLY AFFECTING THE PROVINCE OF TULEAR UNTIL MID-NIGHT ON MONDAY TO TUESDAY. GALE FORCE WINDS MAY OCCASIONALLY BLOW OVER FIANARANTSOA PROVINCE ON TUESDAY MORNING. - HEAVY RAIN AND RISK OF LOCAL FLOODING THIS EVENING ON THE WEST COAST OF TULEAR PROVINCE, OF THE ORDER OF 100 TO 200MM SPREADING EASTWARDS ON TUESDAY, AS FAR AS FIANARANTSOA PROVINCE. ACCUMULATIONS IN THE ORDER OF 100-200MM UP TO LOCALLY 300MM DURING THE PASSAGE OF ALVARO. IN THE MANAKARA AREA, RAINFALL COULD BE HEAVIER (LOCALLY 400/ 500 MM) DUE TO EXISTING CONVECTIVE ACTIVITY GENERATED BY THE CONVERGENCE OF COASTAL FLOWS, AFTER THE PASSAGE OF THE SYSTEM. - AVERAGE WAVES OF THE ORDER OF 4 TO 6M THIS EVENING BETWEEN 12UTC AND 21UTC, CLOSE TO THE IMPACT ZONE, ALONG THE COASTS OF TULEAR PROVINCE. RESIDUAL WAVES OF THE ORDER OF 4M ARE ALSO POSSIBLE ON THE PROVINCE'S NORTHERN COAST UNTIL 00Z. - A SURGE OF THE ORDER OF A METRE IS POSSIBLE AROUND THE ALVARO LANDING POINT.=
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WTIO30 FMEE 020113 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 13/1/20232024 1.A MODERATE TROPICAL STORM 1 (ALVARO) 2.A POSITION 2024/01/02 AT 0000 UTC: WITHIN 30 NM RADIUS OF POINT 21.4 S / 44.8 E (TWENTY ONE DECIMAL FOUR DEGREES SOUTH AND FORTY FOUR DECIMAL EIGHT DEGREES EAST) MOVEMENT: EAST 9 KT 3.A DVORAK ANALYSIS: NIL 4.A CENTRAL PRESSURE: 1001 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 35 KT RADIUS OF MAXIMUM WINDS (RMW): 35 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 85 SE: 100 SW: 100 NW: 165 34 KT NE: 55 SE: 0 SW: 45 NW: 0 48 KT NE: 0 SE: 0 SW: 0 NW: 0 64 KT NE: 0 SE: 0 SW: 0 NW: 0 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1009 HPA / 900 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS (WINDS RADII IN KM): 12H: 2024/01/02 12 UTC: 21.5 S / 46.6 E, VENT MAX= 030 KT, OVERLAND DEPRESSION 28 KT NE: 130 SE: 175 SW: 165 NW: 150 24H: 2024/01/03 00 UTC: 21.6 S / 48.8 E, VENT MAX= 040 KT, MODERATE TROPICAL STORM 28 KT NE: 155 SE: 195 SW: 165 NW: 155 34 KT NE: 110 SE: 150 SW: 85 NW: 85 36H: 2024/01/03 12 UTC: 22.5 S / 50.1 E, VENT MAX= 035 KT, MODERATE TROPICAL STORM 28 KT NE: 175 SE: 215 SW: 175 NW: 165 34 KT NE: 120 SE: 165 SW: 85 NW: 85 48H: 2024/01/04 00 UTC: 23.7 S / 52.0 E, VENT MAX= 030 KT, POST-TROPICAL DEPRESSION 28 KT NE: 195 SE: 230 SW: 175 NW: 175 60H: 2024/01/04 12 UTC: 25.0 S / 54.4 E, VENT MAX= 025 KT, POST-TROPICAL DEPRESSION 72H: 2024/01/05 00 UTC: 26.6 S / 56.4 E, VENT MAX= 025 KT, FILLING UP 2.B LONGER-RANGE OUTLOOK: NIL 2.C ADDITIONAL INFORMATION: ***HAPPY NEW YEAR 2024 FROM RSMC LA REUNION*** ALVARO IS NOW EVOLVING OVER THE MADAGASCAN LANDS AT A GOOD PACE, AND HAS LOST SOME OF ITS INTENSITY OVER THE LAST 6 HOURS UNDER THE EFFECT OF WEST-NORTH-WEST ALOFT SHEAR AROUND 20KT AND THE FACT OF BEING DEPRIVED OF THE WARM SURFACE WATERS OF THE MOZAMBIQUE CHANNEL. ALTHOUGH THE BANDED EYE PATTERN SINCE LANDING (AROUND 16UTC) HAS BEEN PROGRESSIVELY FADING, VERY INTENSE CONVECTION PUFFS HAVE BEEN TRIGGERED NEAR THE CENTER OF THE LOWER LAYERS, WITH SUMMITS COOLING UNDER THE EFFECT OF THE NOCTURNAL CYCLE, MAINTAINING SUMMIT TEMPERATURES OF -81AOC, RIGHT UP TO THE TIME OF THE NETWORK. MOREOVER, MICROWAVE DATA (SSMIS F-17 AND F-16 AND METOP-01) FOR THE NIGHT CONFIRM THE CENTRAL HOT CORE'S GOOD HEALTH. IN THE ABSENCE OF RECENT OBSERVATION DATA, OBJECTIVE ELEMENTS ALLOW US TO CLASSIFY ALVARO AS A MODERATE TROPICAL STORM. NO CHANGE IN TRACK, AS ALVARO FOLLOWS THE WESTERN TRACK DRIVEN BY A NEAR-EQUATORIAL RIDGE TO THE NORTH AND A WEAK TROUGH TO THE SOUTH. AFTER CROSSING THE MALAGASY LANDS ON TUESDAY, THE VORTEX SHOULD EMERGE AT SEA ON THE EAST COAST OF MADAGASCAR IN THE MANAKARA SECTOR (FIANARANTSOA PROVINCE) ON TUESDAY NIGHT. IT SHOULD BE NOTED THAT THERE IS STILL UNCERTAINTY AS TO THE SPEED AT WHICH ALVARO WILL MOVE ON LAND, LEAVING THE TIMING OF ITS EMERGENCE AT SEA UNCERTAIN. THEREAFTER, GUIDED BY THE RIDGE OF HIGH PRESSURE STRENGTHENING TO THE NORTH OF THE MASCAREIGNES AND BY THE FLOW FURTHER SOUTH, ALVARO WILL CONTINUE ITS TRACK IN A GENERAL SOUTH-EASTERLY DIRECTION, BRINGING IT UNDER INCREASINGLY UNFAVORABLE ENVIRONMENTAL CONDITIONS. DUE TO ITS INTERACTION WITH THE MALAGASY LANDMASS, ALVARO HAS ABRUPTLY LEFT THE WARM WATERS OF THE MOZAMBIQUE CANAL, BORDERING THE PROVINCE OF TULEAR. IN ADDITION, THE HIGH-LEVEL SHEAR IS SET TO CONTINUE ERODING THE SYSTEM. DESPITE THIS, CONVECTIVE ACTIVITY SHOULD REMAIN HIGH DUE TO INERTIA. THE METEOR SHOULD RECONSOLIDATE AT THE END OF THE NIGHT FROM TUESDAY TO WEDNESDAY, MOVING OUT TO THE EAST OF MADAGASCAR THANKS TO GOOD SURFACE CONVERGENCE AND A TEMPORARY RETURN TO WARM COASTAL CONDITIONS. THIS POTENTIAL FOR REINTENSIFICATION COULD BE REDUCED IF THE VORTEX WEAKENS MORE MARKEDLY AS IT CROSSES MADAGASCAR. IN THE CURRENT FORECAST, REINTENSIFICATION IS POSSIBLE ON WEDNESDAY, BUT THE INCREASE IN SHEAR AND THE GRADUAL INTRUSION OF DRY AIR ALOFT FROM THE SYSTEM'S NORTH-WESTERN SECTOR SHOULD LOGICALLY WEAKEN ALVARO CONTINUOUSLY FROM WEDNESDAY EVENING ONWARDS. IT WILL THEN GRADUALLY LOSE ITS PURELY TROPICAL CHARACTERISTICS AS IT MOVES INTO THE SOUTHERN LATITUDES. IMPACTS ON MADAGASCAR (BY DEFAULT, THE CHRONOLOGY OF EVENTS IS GIVEN IN UTC): - RESIDUAL GALE-FORCE WINDS ARE STILL BLOWING ALONG THE COASTAL FRINGE OF TULEAR PROVINCE. GALE FORCE WINDS MAY BEGIN TO BLOW ALONG THE COAST OF FIANARANTSOA PROVINCE FROM TUESDAY, AS THE SYSTEM MOVES. - MORE GOOD RAIN LOCALLY TONIGHT OVER TULEAR PROVINCE, OF THE ORDER OF 100MM EVACUATING ON TUESDAY TO THE EAST, REACHING FIANARANTSOA PROVINCE. TOTAL ACCUMULATIONS OF THE ORDER OF 200/300MM UP TO LOCALLY 400 MM OVER THE EPISODE, DURING THE CROSSING OF ALVARO. IN THE MANAKARA AREA, RAINFALL COULD BE HEAVIER (LOCALLY 400/ 500 MM) DUE TO EXISTING CONVECTIVE ACTIVITY GENERATED BY THE CONVERGENCE OF COASTAL FLOWS, AFTER THE PASSAGE OF THE SYSTEM. - AVERAGE WAVES OF AROUND 4 TO 5 M ARE BEING ATTENUATED OVERNIGHT ALONG THE COASTS OF TULEAR PROVINCE.=
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WTXS31 PGTW 020300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04S (ALVARO) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 04S (ALVARO) WARNING NR 004 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 020000Z --- NEAR 21.4S 44.9E MOVEMENT PAST SIX HOURS - 090 DEGREES AT 10 KTS POSITION ACCURATE TO WITHIN 050 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND REPEAT POSIT: 21.4S 44.9E --- FORECASTS: 12 HRS, VALID AT: 021200Z --- 21.6S 46.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 24 HR POSIT: 100 DEG/ 09 KTS --- 24 HRS, VALID AT: 030000Z --- 21.9S 48.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 030 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 125 DEG/ 10 KTS --- 36 HRS, VALID AT: 031200Z --- 23.0S 50.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 130 DEG/ 13 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 040000Z --- 24.7S 52.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 130 DEG/ 12 KTS --- 72 HRS, VALID AT: 050000Z --- 27.7S 56.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 115 DEG/ 08 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 060000Z --- 29.1S 59.7E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 020300Z POSITION NEAR 21.5S 45.3E. 02JAN24. TROPICAL CYCLONE 04S (ALVARO), LOCATED APPROXIMATELY 210 NM SOUTHWEST OF ANTANANARIVO, MADAGASCAR, HAS TRACKED EASTWARD AT 10 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 020000Z IS 997 MB. NEXT WARNINGS AT 021500Z AND 030300Z. // NNNN
WDXS31 PGTW 020300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04S (ALVARO) WARNING NR 004// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 21.4S 44.9E INITIAL INTENSITY: 45 KTS GEOGRAPHIC REFERENCE: 210 NM SOUTHWEST OF ANTANANARIVO, MADAGASCAR MOVEMENT PAST 6 HOURS: EASTWARD AT 10 KTS SIGNIFICANT WAVE HEIGHT: XX FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A RAPIDLY DETERIORATING CIRCULATION THAT IS TRANSITING OVER INCREASINGLY MORE MOUNTAINOUS TERRAIN. A 012214Z ATMS 183GHZ MICROWAVE IMAGE INDICATES DEEP CENTRAL CONVECTION, DEVOID OF ANY SURROUNDING BANDING FEATURES. A LACK OF OTHER IMAGERY OR OBSERVATION DATA MEANS THE INITIAL POSITION IS PLACED WITH RELATIVELY LOW CONFIDENCE. THE INITIAL INTENSITY OF 45 KTS IS ASSESSED WITH LOW CONFIDENCE BASED ON AUTOMATED INTENSITY ESTIMATES LIKE DPRINT INDICATING 57KTS WHILE STORM STRUCTURE AND MODEL GUIDANCE SUPPORT A LOWER INTENSITY COMMENSURATE WITH A SHARPER WEAKENING TREND. INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND RADII). CURRENT STEERING MECHANISM: NEAR EQUATORIAL RIDGE POSITIONED TO THE NORTHEAST, STEERING THE SYSTEM GENERALLY EASTWARD. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: NO CURRENT ESTIMATE FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: HIGHLY UNFAVORABLE VWS: 20-25 KTS SST: 28-29 CELSIUS OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: LOW INITIAL INTENSITY: LOW INITIAL WIND RADII: NOT APPLICABLE 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: OVER THE NEXT 12-20 HOURS, THE MOUNTAINOUS EASTERN COAST OF MADAGASCAR WILL PROGRESSIVELY TEAR APART 04S. BY TAU 24, WHEN THE CIRCULATION FINALLY RE-ENTERS OPEN WATERS, IT MAY BRIEFLY INTENSIFY TO AROUND 40KTS BUT INCREASING VERTICAL WIND SHEAR (VWS) AND DRY AIR ENTRAINMENT WILL QUICKLY RAIN ON THAT PARADE. AS THE NER TO THE NORTH BUILDS POLEWARD, 04S WILL SHIFT TO A SOUTHEASTWARD COURSE. BY TAU 48, VWS SURPASSES 35KTS AND COOLING SSTS FURTHER EXACERBATE AN ALREADY DETERIORATING ENVIRONMENT, RESULTING IN A STEADING WEAKENING TREND THROUGH THE FORECAST PERIOD. THOUGH 04S BEGINS TO INTERACT WITH THE SUBTROPICAL WESTERLIES AND ASSOCIATED BAROCLINIC ZONE BY 96, IT IS ANTICIPATED THAT THE SYSTEM WILL DISSIPATE BEFORE ANY MEASURABLE SUBTROPICAL CHARACTERISTICS CAN BE OBTAINED. MODEL DISCUSSION: WITH THE EXCEPTION OF NVGM, NUMERICAL MODELS ARE IN GOOD AGREEMENT, SHOWING A 160NM SPREAD BY TAU 72. FOR THIS REASON, THE JTWC FORECAST TRACK IS PLACED WITH OVERALL MEDIUM CONFIDENCE. RELIABLE MODEL INTENSITY GUIDANCE IS IN POOR AGREEMENT WITH A 25KT DISCREPANCY BY TAU 24 THAT WORSENS TO 30KTS BY TAU 96. DECAY-SHIPS AND GFS ARE THE LOWEST MEMBERS WHILE HAFS AND COAMPS-TC INDICATE 45KTS THROUGH TAU 84. FOR THIS REASON, THE JTWC INTENSITY FORECAST IS PLACED WITH OVERALL LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: MEDIUM TRACK 72-120 HR: MEDIUM INTENSITY 0 - 72 HR: LOW INTENSITY 72-120 HR: LOW// NNNN
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WTIO30 FMEE 020700 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 14/1/20232024 1.A OVERLAND DEPRESSION 1 (ALVARO) 2.A POSITION 2024/01/02 AT 0600 UTC: WITHIN 30 NM RADIUS OF POINT 21.5 S / 46.0 E (TWENTY ONE DECIMAL FIVE DEGREES SOUTH AND FORTY SIX DECIMAL ZERO DEGREES EAST) MOVEMENT: EAST 10 KT 3.A DVORAK ANALYSIS: NIL 4.A CENTRAL PRESSURE: 1003 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 25 KT RADIUS OF MAXIMUM WINDS (RMW): NIL 6.A EXTENSION OF WIND BY QUADRANTS (KM): NIL 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 900 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS (WINDS RADII IN KM): 12H: 2024/01/02 18 UTC: 21.9 S / 48.4 E, VENT MAX= 030 KT, TROPICAL DEPRESSION 28 KT NE: 155 SE: 230 SW: 240 NW: 120 24H: 2024/01/03 06 UTC: 22.7 S / 50.0 E, VENT MAX= 035 KT, MODERATE TROPICAL STORM 28 KT NE: 185 SE: 250 SW: 240 NW: 140 34 KT NE: 120 SE: 140 SW: 140 NW: 85 36H: 2024/01/03 18 UTC: 24.0 S / 51.5 E, VENT MAX= 035 KT, MODERATE TROPICAL STORM 28 KT NE: 205 SE: 280 SW: 240 NW: 150 34 KT NE: 130 SE: 150 SW: 140 NW: 85 48H: 2024/01/04 06 UTC: 25.6 S / 53.6 E, VENT MAX= 030 KT, POST-TROPICAL DEPRESSION 28 KT NE: 230 SE: 295 SW: 295 NW: 0 60H: 2024/01/04 18 UTC: 27.1 S / 55.6 E, VENT MAX= 030 KT, EXTRATROPICAL DEPRESSION 28 KT NE: 250 SE: 315 SW: 240 NW: 0 72H: 2024/01/05 06 UTC: 28.1 S / 57.1 E, VENT MAX= 030 KT, EXTRATROPICAL DEPRESSION 28 KT NE: 0 SE: 740 SW: 280 NW: 0 2.B LONGER-RANGE OUTLOOK: NIL 2.C ADDITIONAL INFORMATION: ALVARO CONTINUED TO WEAKEN OVERNIGHT AS IT MOVED OVER MADAGASCAR. THE LATEST MICROWAVE IMAGES (LATE-NIGHT SSMIS) SHOW CONVECTION PERSISTING IN THE SYSTEM'S EASTERN SEMICIRCLE. NEVERTHELESS, THE CLOUD TOPS HAVE STARTED TO WARM UP SIGNIFICANTLY. THIS DETERIORATION MUST BE FAVORED BY THE PRESENCE OF A STRONG WESTERLY SHEAR ANALYZED BY CIMSS AT OVER 20KT. THE LATEST OBSERVATIONS OR MODEL ANALYSES NO LONGER SUGGEST THE PRESENCE OF A NEAR GALE FORCE. THE INTENSITY IS THEREFORE LOWERED TO 25KT. NO CHANGE IN TERMS OF TRAJECTORY, ALVARO IS FOLLOWING THE WESTERLY FLOW DRIVEN BY A NEAR-EQUATORIAL RIDGE LOCATED FURTHER NORTH AND A WEAK TROUGH PASSING FURTHER SOUTH. THE VORTEX SHOULD EMERGE OVER SEA ON MADAGASCAR'S EAST COAST SOUTH OF MANANJARY (FIANARANTSOA PROVINCE) THIS EVENING. THEN, DRIVEN BY THE STRENGTHENING RIDGE TO THE NORTH OF THE MASCARENES, ALVARO WILL CONTINUE ITS TRACK IN A GENERAL SOUTHEASTWARD. IT SHOULD BE NOTED THAT THERE IS STILL SOME UNCERTAINTY REGARDING ALVARO'S MOVEMENT SPEED OVER THE NEXT FEW DAYS. THE CURRENT FORECAST IS BASED ON A CONSENSUS OF THE MOST RELIABLE MODELS. AS IT MOVES BACK OVER THE INDIAN OCEAN'S WARM WATERS, ALVARO COULD TEMPORARILY REINTENSIFY, BENEFITING FROM GOOD UPPER LEVEL DIVERGENCE IN THE SOUTHEAST. HOWEVER, THE PERSISTENCE OF A STRONG WESTERLY SHEAR SHOULD LIMIT THE POTENTIAL FOR DEVELOPMENT. SOME DETERMINISTIC MODELS, SUCH AS IFS AND AROME, SUGGEST INTENSIFICATION TO THE SEVERE TROPICAL STORM STAGE, BUT THIS SEEMS UNLIKELY GIVEN THE UNFAVORABLE ENVIRONMENT AND THE RECENT CROSSING OF MADAGASCAR. THE CURRENT FORECAST FORECASTS A PEAK AT THE MODERATE TROPICAL STORM STAGE. THEN, AS IT INTERACTS WITH STRONG UPPER WINDS, ALVARO WILL GRADUALLY LOSE ITS TROPICAL CHARACTERISTICS WHILE MOVING INTO SOUTHERN LATITUDES. IMPACTS ON MADAGASCAR : WIND GUSTS UP TO 100KM/H ARE EXPECTED IN FIANARANTSOA PROVINCE UNTIL LATER NIGHT, ESPECIALLY ON THE COAST. - HEAVY PRECIPITATION IS STILL EXPECTED OVER FIANARANTSOA PROVINCE, WITH ACCUMULATIONS RANGING FROM 100 TO 300MM OVER THE NEXT 24 HOURS. - THE SEA WILL BE MODERATE TO ROUGH BETWEEN MAHANORO AND TAOLAGNARO, WITH WAVES OF 4 TO 5M UNTIL TOMORROW WEDNESDAY.=
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全球热带气旋监测公报
“阿尔瓦罗”向偏东方向移动
时 间：2日14时（北京时）
海 域：马达加斯加境内
命 名：“阿尔瓦罗”，ALVARO
中心位置：南纬21.5度、东经46.0度
强度等级：热带低压
最大风力：6级（13米/秒，相当于我国的热带低压）
中心气压：1003百帕
参考位置：马达加斯加境内
变化过程：过去24小时，“阿尔瓦罗”强度由10级减弱到6级
预报结论：“阿尔瓦罗”将以每小时15-20公里的速度向偏东方向移动，进入洋面后强度还将有所增强。
图1 卫星红外监测图像（北京时间2024年01月02日14时00分）
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WTIO30 FMEE 021225 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 15/1/20232024 1.A OVERLAND DEPRESSION 1 (ALVARO) 2.A POSITION 2024/01/02 AT 1200 UTC: WITHIN 30 NM RADIUS OF POINT 21.6 S / 46.6 E (TWENTY ONE DECIMAL SIX DEGREES SOUTH AND FORTY SIX DECIMAL SIX DEGREES EAST) MOVEMENT: EAST 8 KT 3.A DVORAK ANALYSIS: NIL 4.A CENTRAL PRESSURE: 1003 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 25 KT RADIUS OF MAXIMUM WINDS (RMW): NIL 6.A EXTENSION OF WIND BY QUADRANTS (KM): NIL 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1008 HPA / 900 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS (WINDS RADII IN KM): 12H: 2024/01/03 00 UTC: 22.1 S / 49.1 E, VENT MAX= 030 KT, TROPICAL DEPRESSION 28 KT NE: 155 SE: 230 SW: 240 NW: 120 24H: 2024/01/03 12 UTC: 23.2 S / 51.1 E, VENT MAX= 035 KT, MODERATE TROPICAL STORM 28 KT NE: 185 SE: 260 SW: 240 NW: 140 34 KT NE: 120 SE: 140 SW: 140 NW: 85 36H: 2024/01/04 00 UTC: 24.9 S / 53.1 E, VENT MAX= 035 KT, POST-TROPICAL DEPRESSION 28 KT NE: 205 SE: 280 SW: 240 NW: 150 34 KT NE: 130 SE: 130 SW: 0 NW: 0 48H: 2024/01/04 12 UTC: 26.7 S / 55.3 E, VENT MAX= 035 KT, POST-TROPICAL DEPRESSION 28 KT NE: 220 SE: 405 SW: 335 NW: 0 34 KT NE: 130 SE: 130 SW: 0 NW: 0 60H: 2024/01/05 00 UTC: 28.5 S / 58.2 E, VENT MAX= 030 KT, EXTRATROPICAL DEPRESSION 28 KT NE: 130 SE: 555 SW: 370 NW: 0 72H: 2024/01/05 12 UTC: 29.1 S / 59.9 E, VENT MAX= 030 KT, EXTRATROPICAL DEPRESSION 28 KT NE: 0 SE: 555 SW: 370 NW: 0 2.B LONGER-RANGE OUTLOOK: NIL 2.C ADDITIONAL INFORMATION: ALVARO CLOUD PATTERN HAS CONTINUED TO DETERIORATE WITH AN APPARENT LOW LEVEL CIRCULATION ON SATELLITE IMAGERY DUE TO THE WINDSHEAR. DEEP CONVECTION IS ONLY PRESENT IN THE EASTERN SEMI-CIRCLE. THE LATEST OBSERVATIONS OR MODEL ANALYSES NO LONGER SUGGEST THE PRESENCE OF A NEAR GALE FORCE. THE INTENSITY IS THEREFORE MAINTAINED AT 25KT. NO CHANGE IN TERMS OF TRAJECTORY, ALVARO IS FOLLOWING THE WESTERLY FLOW DRIVEN BY A NEAR-EQUATORIAL RIDGE LOCATED FURTHER NORTH AND A WEAK TROUGH PASSING FURTHER SOUTH. THE VORTEX SHOULD EMERGE OVER SEA ON MADAGASCAR'S EAST COAST SOUTH OF MANANJARY (FIANARANTSOA PROVINCE) THIS EVENING. THEN, DRIVEN BY THE STRENGTHENING RIDGE TO THE NORTH OF THE MASCARENES, ALVARO WILL CONTINUE ITS TRACK IN A GENERAL SOUTHEASTWARD. IT SHOULD BE NOTED THAT THERE IS STILL SOME UNCERTAINTY REGARDING ALVARO'S MOVEMENT SPEED OVER THE NEXT FEW DAYS. THE CURRENT FORECAST IS BASED ON A CONSENSUS OF THE MAIN GUIDANCE (IFS/GFS/CONW). AS IT MOVES BACK OVER THE INDIAN OCEAN'S WARM WATERS, ALVARO COULD TEMPORARILY REINTENSIFY, BENEFITING FROM GOOD UPPER LEVEL DIVERGENCE IN THE SOUTHEAST. HOWEVER, THE PERSISTENCE OF A STRONG WESTERLY SHEAR SHOULD LIMIT THE POTENTIAL FOR DEVELOPMENT. SOME DETERMINISTIC MODELS, SUCH AS IFS AND AROME, KEEP ON SUGGESTIN AN INTENSIFICATION TO THE SEVERE TROPICAL STORM STAGE, BUT THIS SEEMS UNLIKELY GIVEN THE UNFAVORABLE ENVIRONMENT AND THE RECENT CROSSING OF MADAGASCAR. THE CURRENT FORECAST ASSUMES A PEAK AT THE MODERATE TROPICAL STORM STAGE. THEN, AS IT INTERACTS WITH STRONG UPPER WINDS, ALVARO WILL GRADUALLY LOSE ITS TROPICAL CHARACTERISTICS WHILE MOVING INTO SOUTHERN LATITUDES. IMPACTS ON MADAGASCAR : WIND GUSTS UP TO 100KM/H ARE EXPECTED IN FIANARANTSOA PROVINCE UNTIL LATER NIGHT, ESPECIALLY ON THE COAST. - HEAVY PRECIPITATION IS STILL EXPECTED OVER FIANARANTSOA PROVINCE, WITH ACCUMULATIONS RANGING FROM 100 TO 300MM OVER THE NEXT 24 HOURS. - THE SEA WILL BE MODERATE TO ROUGH BETWEEN MAHANORO AND TAOLAGNARO, WITH WAVES OF 4 TO 5M UNTIL TOMORROW WEDNESDAY.=
最后于 2024-01-02 21:05:00 被ygsj24编辑 ，原因： -
WTXS31 PGTW 021500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 04S (ALVARO) WARNING NR 005// RMKS/ 1. TROPICAL CYCLONE 04S (ALVARO) WARNING NR 005 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 021200Z --- NEAR 22.1S 47.5E MOVEMENT PAST SIX HOURS - 105 DEGREES AT 12 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY REPEAT POSIT: 22.1S 47.5E --- FORECASTS: 12 HRS, VALID AT: 030000Z --- 22.6S 49.7E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 125 DEG/ 12 KTS --- 24 HRS, VALID AT: 031200Z --- 23.9S 51.9E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 130 DEG/ 11 KTS --- 36 HRS, VALID AT: 040000Z --- 25.4S 53.8E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 130 DEG/ 15 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 041200Z --- 27.4S 56.4E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 021500Z POSITION NEAR 22.2S 48.1E. 02JAN24. TROPICAL CYCLONE 04S (ALVARO), LOCATED APPROXIMATELY 192 NM SOUTH OF ANTANANARIVO, MADAGASCAR, HAS TRACKED EAST-SOUTHEASTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. MINIMUM CENTRAL PRESSURE AT 021200Z IS 1003 MB. NEXT WARNINGS AT 030300Z AND 031500Z.// NNNN
WDXS31 PGTW 021500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL CYCLONE 04S (ALVARO) WARNING NR 005// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. SUMMARY: INITIAL POSITION: 22.1S 47.5E INITIAL INTENSITY: 30 KTS GEOGRAPHIC REFERENCE: 192 NM SOUTH OF ANTANANARIVO, MADAGASCAR MOVEMENT PAST 6 HOURS: EAST-SOUTHEASTWARD AT 12 KTS SIGNIFICANT WAVE HEIGHT: XX FEET SATELLITE ANALYSIS, INITIAL POSITION AND INTENSITY DISCUSSION: ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS THAT TROPICAL CYCLONE (TC) 04S (ALVARO) HAS UNDERGONE RAPID VORTEX DECOUPLING, WITH A RAGGED LOW LEVEL CIRCULATION CENTER (LLCC) NOW VISIBLE WEST OF THE NORTH-SOUTH ORIENTED TERRAIN FEATURES, WHILE THE MID-LEVEL VORTICITY CENTER AND ASSOCIATED CONVECTION CONTINUES TO PUSH OFF TO THE EAST. A 021047Z ATMS 165GHZ MICROWAVE IMAGE SHOWED WEAK LOW-LEVEL BANDING FEATURES DISPLACED TO THE WEST OF AN AREA OF SYMMETRICAL CONVECTION, WHICH MARKS THE EASTERN VORTICITY LOBE. THE INITIAL POSITION IS PLACED CLOSER TO THE MID-LEVEL VORTICITY CENTER, ON THE WESTERN SIDE OF THE CONVECTION, IN ANTICIPATION OF A RAPID REDEVELOPMENT UNDER THE MID-LEVEL ROTATION ONCE IT REACHES THE EAST COAST. SURFACE OBSERVATIONS FROM FARAFANGANA, ALONG THE EAST COAST, REPORT SURFACE WINDS FROM THE SOUTHEAST AT 14 KNOTS, SUGGESTING A LOW-LEVEL ROTATION MAY ALREADY BE DEVELOPING TO THE NORTH OF THE STATION, AND PROVIDING SOME MODEST SUPPORT TO THE PLACEMENT OF THE INITIAL POSITION. OVERALL HOWEVER, THE INITIAL POSITION IS ASSESSED WITH LOW CONFIDENCE. THE INITIAL INTENSITY IS LIKEWISE SET WITH LOW CONFIDENCE DUE TO THE LACK OF SATELLITE-BASED INTENSITY ESTIMATES, WITH THE LONE EXCEPTION OF THE CIMSS DPRINT, AT 37 KNOTS. AS MENTIONED ABOVE, THE SYSTEM HAS DECOUPLED AND THE BEST TRACK IS TRACKING THE EASTERN, MOSTLY MID-LEVEL, ROTATION LEADING TO A TRACK SPEED OF 12 KNOTS TOWARDS THE EAST-SOUTHEAST ALONG THE SOUTHWESTERN PERIPHERY OF A DEEP-LAYER NEAR EQUATORIAL RIDGE (NER) CENTERED TO THE NORTHEAST. ANALYSIS REVEALS A MARGINALLY FAVORABLE ENVIRONMENT CHARACTERIZED BY MODERATE TO STRONG POLEWARD OUTFLOW OFFSET BY 20-25 KNOTS OF WESTERLY SHEAR THE INFLUENCE OF TERRAIN. INITIAL WIND RADII BASIS: NOT APPLICABLE (THERE ARE NO INITIAL WIND RADII). CURRENT STEERING MECHANISM: SOUTHWESTERN PERIPHERY OF A DEEP-LAYER NER TO THE NORTHEAST. AGENCY DVORAK AND AUTOMATED FIXES: PGTW: NO CURRENT ESTIMATE FORECASTER ASSESSMENT OF CURRENT ENVIRONMENT: MARGINALLY FAVORABLE VWS: 20-25 KTS SST: OVER LAND OUTFLOW: MODERATE POLEWARD ANALYSIS CONFIDENCE: INITIAL POSITION: LOW INITIAL INTENSITY: LOW INITIAL WIND RADII: NOT APPLICABLE 3. FORECAST REASONING. SIGNIFICANT FORECAST CHANGES: THERE ARE NO SIGNIFICANT CHANGES TO THE FORECAST FROM THE PREVIOUS WARNING. FORECAST DISCUSSION: TC 04S IS FORECAST TO TRACK SOUTHEASTWARD ALONG THE SOUTHERN SIDE OF THE NER THROUGHOUT THE SHORT DURATION OF THE FORECAST PERIOD, WITH SOME ACCELERATION AFTER TAU 12 AS THE GRADIENT TIGHTENS BETWEEN THE NER AND A TROUGH TO THE SOUTH. THE MID-LEVEL VORTICITY ASSOCIATED WITH THE EASTERN LOBE OF A FULLY DECOUPLED TC 04S, IS SET TO EMERGE BACK OVER WATER OFF THE EASTERN COAST OF MADAGASCAR WITHIN THE NEXT FEW HOURS. ONCE THIS OCCURS, A RAPID, TOP-DOWN REDEVELOPMENT IS ANTICIPATED, TAKING ADVANTAGE OF A BRIEF WINDOW OF SLIGHTLY LOWER VERTICAL WIND SHEAR (VWS), WARM SSTS APPROACHING 28C AND STRONG POLEWARD OUTFLOW, ALLOWING THE SYSTEM TO REINTENSIFY UP TO 40 KNOTS BY TAU 12. SHEAR IS EXPECTED TO REMAIN NEAR 20 KNOTS THROUGH ABOUT TAU 24 BEFORE RAPIDLY INCREASING TO VERY HIGH LEVELS. THE RAPID INCREASE IN WEST-NORTHWESTERLY SHEAR WILL ALSO USHER IN A VERY DRY AIR MASS. THE COMBINED EFFECTS OF THE INCREASED SHEAR AND DRY AIR WILL DECAPITATE THE SYSTEM AND SMOTHER THE REMAINING LOW-LEVEL CIRCULATION AFTER TAU 24, LEADING TO RAPID WEAKENING AND DISSIPATION BY TAU 48. MODEL DISCUSSION: DETERMINISTIC TRACK GUIDANCE IS IN VERY TIGHT AGREEMENT, WITH THE ENTIRE CONSENSUS PACKAGE CONFINED TO A 60NM CROSS-TRACK ENVELOPE AT TAU 48. THE JTWC FORECAST LIES CLOSE TO THE MULTI-MODEL CONSENSUS MEAN WITH HIGH CONFIDENCE. INTENSITY GUIDANCE IS MIXED, WITH THE COAMPS-TC (GFS VERSION) AND HAFS-A MODELS SUGGESTING RAPID INTENSIFICATION BY TAU 12, WITH PEAKS BETWEEN 50 KTS TO 60 KTS, WHILE THE SHIPS AND GFS GUIDANCE SHOW THE SYSTEM BARELY REACHING 35 KTS WITHIN THE FIRST 24 HOURS. THE JTWC FORECAST TRACKS THE CONSENSUS MEAN THROUGH TAU 24, THEN DISSIPATES THE SYSTEM MORE IN LINE WITH THE SHIPS GUIDANCE, WITH LOW CONFIDENCE. FORECAST CONFIDENCE: TRACK 0 - 72 HR: HIGH INTENSITY 0 - 72 HR: LOW// NNNN
最后于 2024-01-03 04:40:00 被ygsj24编辑 ，原因： -
WTIO30 FMEE 021811 RSMC / TROPICAL CYCLONE CENTER / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER: 16/1/20232024 1.A TROPICAL DEPRESSION 1 (ALVARO) 2.A POSITION 2024/01/02 AT 1800 UTC: WITHIN 30 NM RADIUS OF POINT 21.6 S / 48.0 E (TWENTY ONE DECIMAL SIX DEGREES SOUTH AND FORTY EIGHT DECIMAL ZERO DEGREES EAST) MOVEMENT: EAST 12 KT 3.A DVORAK ANALYSIS: 2.5/2.5/D 0.0/6 H 4.A CENTRAL PRESSURE: 999 HPA 5.A MAX AVERAGE WIND SPEED (10 MN): 30 KT RADIUS OF MAXIMUM WINDS (RMW): 65 KM 6.A EXTENSION OF WIND BY QUADRANTS (KM): 28 KT NE: 110 SE: 110 SW: 65 NW: 65 7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1006 HPA / 700 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: MEDIUM 1.B FORECASTS (WINDS RADII IN KM): 12H: 2024/01/03 06 UTC: 22.4 S / 50.3 E, VENT MAX= 045 KT, MODERATE TROPICAL STORM 28 KT NE: 130 SE: 175 SW: 130 NW: 0 34 KT NE: 0 SE: 100 SW: 0 NW: 0 24H: 2024/01/03 18 UTC: 23.5 S / 51.7 E, VENT MAX= 035 KT, MODERATE TROPICAL STORM 28 KT NE: 130 SE: 175 SW: 150 NW: 0 34 KT NE: 0 SE: 100 SW: 0 NW: 0 36H: 2024/01/04 06 UTC: 25.1 S / 54.1 E, VENT MAX= 035 KT, POST-TROPICAL DEPRESSION 28 KT NE: 130 SE: 130 SW: 0 NW: 0 34 KT NE: 0 SE: 95 SW: 0 NW: 0 48H: 2024/01/04 18 UTC: 26.9 S / 57.4 E, VENT MAX= 035 KT, POST-TROPICAL DEPRESSION 28 KT NE: 110 SE: 415 SW: 230 NW: 0 34 KT NE: 0 SE: 285 SW: 165 NW: 0 60H: 2024/01/05 06 UTC: 27.8 S / 60.0 E, VENT MAX= 030 KT, EXTRATROPICAL DEPRESSION 28 KT NE: 130 SE: 185 SW: 0 NW: 0 72H: 2024/01/05 18 UTC: 28.2 S / 61.9 E, VENT MAX= 030 KT, EXTRATROPICAL DEPRESSION 28 KT NE: 0 SE: 185 SW: 0 NW: 0 2.B LONGER-RANGE OUTLOOK: NIL 2.C ADDITIONAL INFORMATION: T=CI=2.5 CONVECTIVE ACTIVITY HAS PICKED UP SHARPLY AT SEA OVER THE PAST 6 HOURS AS THE ESTIMATED CENTER APPROACHES THE EASTERN COAST OF MADAGASCAR. IN CONNECTION WITH THIS RESUMPTION, ALVARO'S CLOUD CONFIGURATION IS SHOWING A CURVED BAND STRUCTURE, DISTURBED BY THE PRESENCE OF LAND, WITH VERY COLD CLOUD TOPS. WITH CONVECTIVE ACTIVITY HAVING RESUMED MORE THAN 6 HOURS AGO, A DVORAK ANALYSIS CAN AGAIN BE MADE OF THE ORDER OF 2.5, CLASSIFYING ALVARO AS A TROPICAL DEPRESSION WITH ESTIMATED WINDS OF THE ORDER OF 30KT, PARTICULARLY AT SEA. THE LATEST MICROWAVES AND VISIBLE SATELLITE ANIMATIONS PROVIDE LIMITED HELP IN ESTIMATING ALVARO'S CENTER. AT 18UTC, THE CENTER SHOULD SOON REACH THE SEA, BUT THIS LOCATION REMAINS UNCERTAIN. WITH LITTLE CHANGE IN TERMS OF TRACK, ALVARO IS FOLLOWING THE DIRECTIONAL FLOW INDUCED BY THE RIDGE OF HIGH PRESSURE, WHICH IS STRENGTHENING OVER THE NORTHERN MASCARENE ISLANDS. ALTHOUGH THE EXACT LOCATION OF ALVARO AT THE MOMENT IS TRICKY TO DETERMINE, IT IS RETURNING TO THE SEA AND WILL THEREFORE CONTINUE TO TRACK IN A GENERAL SOUTHEASTERLY DIRECTION. THIS TRACK WILL REMAIN FAIRLY CONSTANT, ALTHOUGH THE SPEED COULD BE A LITTLE MORE MARKED IN THE FINAL STAGES. AS IT MOVES BACK OVER THE WARM WATERS OF THE INDIAN OCEAN, ALVARO SHOULD TEMPORARILY REINTENSIFY, BENEFITING FROM GOOD ALTITUDE DIVERGENCE ON THE SOUTHEAST COAST. THIS CONTEXT IS ALREADY NOTABLE, WITH MARKED CONVECTIVE ACTIVITY NEAR THE MALAGASY COAST. HOWEVER, THE PERSISTENCE OF MODERATE TO STRONG WESTERLY SHEAR (MORE SO IN THE SOUTHERN SECTOR OF THE SYSTEM) SHOULD LIMIT THE POTENTIAL FOR DEVELOPMENT TO LESS THAN 24 HOURS. THE CURRENT FORECAST ASSUMES A PEAK AT THE MODERATE TROPICAL STORM STAGE AT SHORT NOTICE, THUS MODERATING THE SIGNAL OF CERTAIN MUCH MORE REACTIVE MODELS. THEREAFTER, AS IT INTERACTS WITH STRONG WINDS ALOFT AND THE INTRUSION OF DRY AIR, ALVARO WILL GRADUALLY LOSE ITS TROPICAL CHARACTERISTICS AS IT CONTINUES ITS SOUTHWARD TRACK. IMPACTS ON MADAGASCAR : - WIND GUSTS OF UP TO 100KM/H ARE STILL EXPECTED UNTIL THE END OF THE NIGHT IN THE PROVINCE OF FIANARANTSOA, PARTICULARLY ALONG THE COAST. - HEAVY PRECIPITATION IS STILL EXPECTED OVER FIANARANTSOA PROVINCE, WITH ACCUMULATIONS RANGING FROM 100 TO 300MM OVER THE NEXT 24 HOURS. - THE SEA WILL BE MODERATE TO ROUGH BETWEEN MAHANORO AND TAOLAGNARO, WITH WAVES OF 4 TO 5M UNTIL TOMORROW WEDNESDAY.=
