MFR 28/18Z再將近中心最大風速提升至80kts，中心氣壓降至964hpa；JTWC定強則維持與前二報相同，強度已達巔峰。
MFR：

ZCZC 326

WTIO30 FMEE 281804
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 24/15/20182019
1.A TROPICAL CYCLONE 15 (LORNA)
2.A POSITION 2019/04/28 AT 1800 UTC:
WITHIN 30 NM RADIUS OF POINT 18.9 S / 90.0 E
(EIGHTEEN    DECIMAL NINE   DEGREES SOUTH AND
NINETY    DECIMAL ZERO   DEGREES EAST)
MOVEMENT: SOUTH 10 KT
3.A DVORAK ANALYSIS: 5.0/5.0/D 1.0/24 H
4.A CENTRAL PRESSURE: 964 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 80 KT
RADIUS OF MAXIMUM WINDS (RMW): 37 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 370 SE: 740 SW: 650 NW: 370
34 KT NE: 150 SE: 370 SW: 370 NW: 150
48 KT NE: 90 SE: 110 SW: 110 NW: 90
64 KT NE: 70 SE: 70 SW: 70 NW: 70
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 1900 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP
1.B FORECASTS:
12H: 2019/04/29 06 UTC: 20.9 S / 89.7 E, VENT MAX= 065 KT, TROPICAL
CYCLONE
24H: 2019/04/29 18 UTC: 23.1 S / 89.5 E, VENT MAX= 050 KT,
POST-TROPICAL DEPRESSION
36H: 2019/04/30 06 UTC: 25.5 S / 89.8 E, VENT MAX= 040 KT,
POST-TROPICAL DEPRESSION
48H: 2019/04/30 18 UTC: 29.0 S / 91.1 E, VENT MAX= 035 KT,
POST-TROPICAL DEPRESSION
60H: 2019/05/01 06 UTC: 33.6 S / 95.1 E, VENT MAX= 030 KT,
EXTRATROPICAL DEPRESSION
2.B LONGER-RANGE OUTLOOK:
NIL
2.C ADDITIONAL INFORMATION:
T=CI=5.0
OVER THE LAST 6 HOURS, EYE HAS BECOME PROGRESSIVELY BETTER DEFINED.
IN THE SAME TIME, TOP CLOUD TEMPERATURES HAS REMAINED VERY COLD. AS A
CONSEQUENCE, RAW T NUMBERS HAVE RAISED AT 6.0 BETWEEN 1500Z AND
1700Z. PARTIAL 1121Z ASCAT SWATH ANNOUNCED THIS IMPROVEMENT SHOWING A
RING OF CONVECTION VERY INTENSE. BUT GMI IMAGERIES SHOWED ALSO A TILT
BETWEEN THE LOW LEVEL CIRCULATION AND THE MID LEVEL CIRCULATION DUE
TO THE INCREASING WESTERN VERTICAL WINDSHEAR. BY THE WAY, 89 GHZ
1517Z AMSU MICROWAVE IMAGERY SHOWS AN ERODED EYEWALL WITHIN THE
NORTHERN QUADRANT ANNOUNCING A WEAKENING OF THE SYSTEM.
DURING THE NEXT FEW DAYS, LORNA SHOULD KEEP ON ITS SOUTHWARD TRACK,
NEAR 90AOEAST, STEERING BY THE WESTERN SIDE OF THE MID LEVEL RIDGE.
FROM TOMORROW, A MID LEVEL RIDGE LOCATED SOUTH OF THE SYSTEM THAT
LIMITED A FASTER EVACUATION TO THE SOUTH IS EXPECTED TO MOVE EASTWARD
WITH THE ARRIVAL OF A DEEP UPPER LEVEL TROUGH COMING FROM THE
SOUTH-WEST. SO LORNA SHOULD ACCELERATE TOWARDS THE SOUTHEAST AHEAD
THE TROUGH.
THE TIME WINDOW FOR CONDUCIVE CONDITIONS IS EXPECTED TO END SHORTLY,
WITH A FORECAST INCREASE OF THE NORTH-WESTERLY SHEAR, INDUCING DRY
AIR INTRUSIONS IN MID TROPOSPHERE.THE WEAKENING OCEANIC HEAT
POTENTIAL SOUTH OF 18S SHOULD ACCELERATE THAT WEAKENING. TOMORROW,
LORNA SHOULD START TO LOOSE ITS PURELY TROPICAL CHARACTERISTICS AS
THE SYSTEM INTERACTS WITH THE SUBTROPICAL JET, BEFORE FILLING UP MORE
CLEARLY FROM TUESDAY.=
NNNN

JTWC：

WTXS32 PGTW 282100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE 25S (LORNA) WARNING NR 022//
RMKS/
1. TROPICAL CYCLONE 25S (LORNA) WARNING NR 022   
   01 ACTIVE TROPICAL CYCLONE IN SOUTHIO
   MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
   WIND RADII VALID OVER OPEN WATER ONLY
    ---
   WARNING POSITION:
   281800Z --- NEAR 19.4S 90.5E
     MOVEMENT PAST SIX HOURS - 160 DEGREES AT 13 KTS
     POSITION ACCURATE TO WITHIN 030 NM
     POSITION BASED ON CENTER LOCATED BY SATELLITE
   PRESENT WIND DISTRIBUTION:
   MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT
                            040 NM SOUTHEAST QUADRANT
                            030 NM SOUTHWEST QUADRANT
                            025 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT
                            075 NM SOUTHEAST QUADRANT
                            055 NM SOUTHWEST QUADRANT
                            045 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 135 NM NORTHEAST QUADRANT
                            140 NM SOUTHEAST QUADRANT
                            105 NM SOUTHWEST QUADRANT
                            095 NM NORTHWEST QUADRANT
   REPEAT POSIT: 19.4S 90.5E
    ---
   FORECASTS:
   12 HRS, VALID AT:
   290600Z --- 21.3S 90.1E
   MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
                            020 NM SOUTHEAST QUADRANT
                            015 NM SOUTHWEST QUADRANT
                            005 NM NORTHWEST QUADRANT
   RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT
                            100 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 250 NM NORTHEAST QUADRANT
                            300 NM SOUTHEAST QUADRANT
                            180 NM SOUTHWEST QUADRANT
                            100 NM NORTHWEST QUADRANT
   VECTOR TO 24 HR POSIT: 175 DEG/ 10 KTS
    ---
   24 HRS, VALID AT:
   291800Z --- 23.3S 90.2E
   MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT
                            050 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            020 NM NORTHWEST QUADRANT
   RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT
                            270 NM SOUTHEAST QUADRANT
                            120 NM SOUTHWEST QUADRANT
                            040 NM NORTHWEST QUADRANT
   VECTOR TO 36 HR POSIT: 175 DEG/ 11 KTS
    ---
   36 HRS, VALID AT:
   300600Z --- 25.5S 90.5E
   MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   BECOMING EXTRATROPICAL
   RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT
                            230 NM SOUTHEAST QUADRANT
                            040 NM SOUTHWEST QUADRANT
                            010 NM NORTHWEST QUADRANT
   VECTOR TO 48 HR POSIT: 160 DEG/ 16 KTS
    ---
   EXTENDED OUTLOOK:
   48 HRS, VALID AT:
   301800Z --- 28.5S 91.6E
   MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT
   WIND RADII VALID OVER OPEN WATER ONLY
   EXTRATROPICAL
   RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT
                            190 NM SOUTHEAST QUADRANT
                            010 NM SOUTHWEST QUADRANT
                            000 NM NORTHWEST QUADRANT
    ---
REMARKS:
282100Z POSITION NEAR 19.9S 90.4E.
TROPICAL CYCLONE (TC) 25S (LORNA), LOCATED APPROXIMATELY 565 NM
SOUTHWEST OF COCOS ISLAND, AUSTRALIA, HAS TRACKED SOUTH-SOUTHEASTWARD
AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY SHOWS THE SYSTEM CONTINUED TO ELONGATE ALONG THE
SOUTHERN FLANK, AN INDICATION OF STRONG VERTICAL WIND SHEAR. CENTRAL
CLOUD TOPS ALSO CONTINUE TO WARM. HOWEVER, POLEWARD OUTFLOW REMAINS
STRONG AND RAIN BANDS REMAIN TIGHTLY WRAPPED INTO THE LOW LEVEL
CIRCULATION (LLC). THE INITIAL POSITION IS EXTRAPOLATED FROM AN EYE
FEATURE IN THE EIR LOOP THAT HAS SINCE BECOME OBSCURED. THE INITIAL
INTENSITY IS BASED ON THE DVORAK ESTIMATE OF T4.5/75KTS FROM PGTW.
UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS IN AN AREA OF HIGH (25
KNOTS PLUS) VERTICAL WIND SHEAR (VWS). HOWEVER, STRONG POLEWARD
OUTFLOW CONTINUES TO PROVIDE VENTILATION TO THE ASSOCIATED
CONVECTION. ALONG TRACK SEA SURFACE TEMPERATURES ARE BECOMING LESS
CONDUCIVE AT 26C. TC 25S WILL CONTINUE TO TRACK ALONG THE WESTERN
PERIPHERY OF A DEEP-LAYERED SUBTROPICAL RIDGE (STR) TO THE EAST.
THE STR IS EXPECTED TO BUILD SLIGHTLY AND STEER THE CYCLONE ON A MORE
SOUTH-SOUTHWESTWARD TRACK OVER THE NEXT DAY. AFTERWARD, A MIDLATITUDE
TROUGH APPROACHING FROM THE SOUTHWEST WILL WEAKEN THE STR AND ALLOW A
MORE SOUTH-SOUTHEASTWARD TRACK. BY TAU 48, TC LORNA WILL BEGIN
EXTRA-TROPICAL TRANSITION AND BY TAU 48, WILL TRANSFORM INTO A
STORM-FORCE COLD-CORE LOW. INCREASING VWS AND COOLING SSTS WILL ALSO
TRIGGER A GRADUAL WEAKENING PHASE, ERODING THE CYCLONE TO 35 KNOTS BY
TAU 48, POSSIBLY DISSIPATION. NUMERICAL MODELS ARE IN TIGHT AGREEMENT,
LENDING HIGH CONFIDENCE TO THE JTWC TRACK FORECAST. MAXIMUM
SIGNIFICANT WAVE HEIGHT AT 281800Z IS 27 FEET. NEXT WARNINGS AT
290300Z, 290900Z, 291500Z AND 292100Z.//
NNNN

MFR 28/06Z升格為熱帶氣旋，近中心最大風速升至70kts，中心氣壓974hpa。

ZCZC 489
WTIO30 FMEE 280639 RRA
RSMC / TROPICAL CYCLONE CENTER / LA REUNION
TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN)
0.A WARNING NUMBER: 22/15/20182019
1.A TROPICAL CYCLONE 15 (LORNA)
2.A POSITION 2019/04/28 AT 0600 UTC:
WITHIN 20 NM RADIUS OF POINT 16.8 S / 89.5 E
(SIXTEEN    DECIMAL EIGHT   DEGREES SOUTH AND
EIGHTY NINE    DECIMAL FIVE   DEGREES EAST)
MOVEMENT: SOUTH 10 KT
3.A DVORAK ANALYSIS: 4.5/4.5/D 0.5/24 H
4.A CENTRAL PRESSURE: 974 HPA
5.A MAX AVERAGE WIND SPEED (10 MN): 70 KT
RADIUS OF MAXIMUM WINDS (RMW): 37 KM
6.A EXTENSION OF WIND BY QUADRANTS (KM):
28 KT NE: 370 SE: 370 SW: 480 NW: 370
34 KT NE: 150 SE: 170 SW: 170 NW: 90
48 KT NE: 40 SE: 90 SW: 90 NW: 40
7.A FIRST CLOSED ISOBAR (PRESSURE / AVERAGE DIAM): 1010 HPA / 1700 KM
8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP
1.B FORECASTS:
12H: 2019/04/28 18 UTC: 18.8 S / 89.4 E, VENT MAX= 070 KT, TROPICAL
CYCLONE
24H: 2019/04/29 06 UTC: 20.6 S / 89.0 E, VENT MAX= 050 KT,
POST-TROPICAL DEPRESSION
36H: 2019/04/29 18 UTC: 22.3 S / 88.7 E, VENT MAX= 040 KT,
POST-TROPICAL DEPRESSION
48H: 2019/04/30 06 UTC: 24.3 S / 89.0 E, VENT MAX= 035 KT,
POST-TROPICAL DEPRESSION
60H: 2019/04/30 18 UTC: 26.7 S / 90.2 E, VENT MAX= 030 KT,
EXTRATROPICAL DEPRESSION
2.B LONGER-RANGE OUTLOOK:
NIL
2.C ADDITIONAL INFORMATION:
T=4.5+
NNNN

另JTWC亦認同一時間近中心最大風速升至75kts，中心氣壓975hpa，強度已近巔峰。

25S LORNA
As of 06:00 UTC Apr 28, 2019:

Location: 16.8°S 89.7°E
Maximum Winds: 75 kt
Minimum Central Pressure: 975 mb

18Z命名“Lorna”，巔峰上望熱帶氣旋(75KT)。

WTIO31 FMEE 231845
CMRS / CENTRE DES CYCLONES TROPICAUX DE LA REUNION
BULLETIN D'ANALYSE ET DE PREVISION CYCLONIQUE (SUD-OUEST OCEAN INDIEN)
0.A NUMERO DU BULLETIN : 4/15/20182019
1.A TEMPETE TROPICALE MODEREE 15 (LORNA)
2.A POSITION A 1800 UTC LE 23/04/2019 :
DANS UN RAYON DE 30 MN AUTOUR DU POINT 9.6 S / 82.9 E
(NEUF DEGRES SIX SUD ET QUATRE-VINGT DEUX DEGRES NEUF EST)
DEPLACEMENT: SUD-SUD-EST 10 KT
3.A ANALYSE DE DVORAK: 3.0/3.0/D 1.0/18 H
4.A PRESSION AU CENTRE: 995 HPA
5.A VENT MAX (MOYEN/10 MN): 40 KT
RAYON DES VENTS MAXIMAUX (RVM): 46 KM
6.A EXTENSION DES VENTS PAR QUADRANTS (KM):
28 KT NE: 240 SE: 150 SO: NO: 200
34 KT NE: 150 SE: 90 SO: NO: 110
7.A COTE/DIAM PREMIERE ISOBARE FERMEE: 1008 HPA / 900 KM
8.A EXTENSION VERTICALE DE LA CIRCULATION CYCLONIQUE: PROFONDE
1.B PREVISIONS:
12H: 24/04/2019 06 UTC: 10.3 S / 83.1 E, VENT MAX= 045 KT, TEMPETE TROPICALE
MODEREE
24H: 24/04/2019 18 UTC: 11.1 S / 83.6 E, VENT MAX= 050 KT, FORTE TEMPETE
TROPICALE
36H: 25/04/2019 06 UTC: 11.8 S / 84.2 E, VENT MAX= 060 KT, FORTE TEMPETE
TROPICALE
48H: 25/04/2019 18 UTC: 12.5 S / 84.8 E, VENT MAX= 070 KT, CYCLONE TROPICAL
60H: 26/04/2019 06 UTC: 13.1 S / 85.6 E, VENT MAX= 075 KT, CYCLONE TROPICAL
72H: 26/04/2019 18 UTC: 13.7 S / 86.7 E, VENT MAX= 070 KT, CYCLONE TROPICAL
2.B TENDANCE ULTERIEURE:
96H: 27/04/2019 18 UTC: 15.4 S / 89.3 E, VENT MAX= 060 KT, FORTE TEMPETE
TROPICALE
120H: 28/04/2019 18 UTC: 19.2 S / 90.5 E, VENT MAX= 050 KT, FORTE TEMPETE
TROPICALE
2.C COMMENTAIRES:
T=3.0- CI=3.0-
AU COURS DES DERNIERES 6 HEURES, DES BURSTS DE CONVECTION SE SONT PRODUITES PRES DU CENTRE. LA PASSE ASCAT DE 1523Z MONTRE UNE STRUCTURE
ASSEZ ALLONGEE ET TRES DISSYMÉTRIQUE AVEC LES VENTS LES PLUS FORTS
DANS LE QUADRANT NORD-EST. LA PASSE ASCAT PERMET D'ESTIMER LES VENTS
MAXIMAUX A 40 KT. AUSSI, LE SYSTEME A DONC ETE BAPTISÉ LORNA PAR LE
SERVICE METEOROLIQUE MAURICIEN.
LE SYSTEME SE DEPLACE VERS LE SUD-EST SOUS L'INFLUENCE DE LA DORSALE
PROCHE EQUATORIALE DE BASSE A MOYENNE TROPOSPHERE. AU COURS DES
PROCHAINS JOURS, CETTE DORSALE SE DECALE VERS L'OUEST ALORS QU'UN
TALWEG DE HAUTE A MOYENNE TROPOSPHERE S'INSTALLE GRADUELLEMENT AU
SUD-OUEST DU SYSTEME. CETTE CONFIGURATION EST ALORS FAVORABLE A LA
POURSUITE D'UNE TRAJECTOIRE GLOBALE VERS LE SUD-EST AU COURS DES
PROCHAINS JOURS. CETTE ORIENTATION EST EN BONNE ACCORD AVEC LES
MODELES MAIS L'INCERTITUDE PORTE PLUTOT SUR LA VITESSE DE DEPLACEMENT
DU SYSTEME. CERTAINS MODELES SUGGERENT AUSSI QUE LE SYSTEME POURRAIT
INTERAGIR AVEC UN SYSTEME SE DEVELOPPANT PLUS A L'EST. DANS CE CAS, UN
REAJUSTEMENT DE LA TRAJECTOIRE VERS L'EST POURRAIT ETRE POSSIBLE.
SUR CETTE TRAJECTOIRE, LES CONDITIONS ENVIRONNEMENTALES SONT
FAVORABLES A LA POURSUITE DE L'INTENSIFICATION. LE CISAILLEMENT VERTICAL
EST PREVU RESTER FAIBLE A MODERÉ AVEC UNE EXCELLENTE DIVERGENCE
D'ALTITUDE CÔTÉ POLAIRE. A PARTIR DE VENDREDI, LE CISAILLEMENT DE
SECTEUR NORD-EST EST PREVU SE RENFORCER CONDUISANT A UN
AFFAIBLISSEMENT PROGRESSIF DU SYSTEME. IL EXISTE ENCORE UNE INCERTITUDE
SUR CE POINT EN LIEN AVEC LA VITESSE DE DEPLACEMENT, AMENANT LE SYSTEME
PLUS OU MOINS RAPIDEMENT DANS UN ENVIRONNEMENT CISAILLE.