TROPICAL DISTURBANCE ADVISORY NUMBER A25 ISSUED FROM RSMC NADI
Feb 161354 UTC.
TROPICAL CYCLONE WINSTON CENTRE 975HPA CATEGORY 2 WAS LOCATED NEAR
18.0 SOUTH 173.7 WEST AT 161200 UTC. POSITION FAIR BASED ON HR MTSAT
IR IMAGERY AND SURFACE OBSERVATIONS. CYCLONE MOVING EAST-NORTHEAST AT
ABOUT 12 KTS. MAXIMUM 10 MINUTE AVERAGE WINDS NEAR THE CENTRE
ESTIMATED AT ABOUT 60 KNOTS.
EXPECT WINDS OVER 47 KNOTS WITHIN 60 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 33 KNOTS WITHIN 120 NAUTICAL MILES IN NE
QUADRANT,
WITHIN 150 NAUTICAL MILES IN SE QUADRANT,
WITHIN 90 NAUTICAL MILES IN W
SEMICIRCLE.
DEEP CONVECTION REMAINS PERSISTENT WITH CONVECTIVE BAND WRAPPING
AROUND LLCC. ORGANIZATION REMAINS GOOD. SST AROUND 30 DEGREES
CELSIUS. SYSTEM LIES UNDER A MODERATE UPPER DIVERGENCE REGION AND IN
LOW TO MODERATE SHEARED ENVIRONMENT. OUTFLOW GOOD TO THE EAST. SYSTEM
IS BEING STEERED TO THE EAST-NORTHEAST BY THE WEST-SOUTHWEST DEEP
LAYER MEAN WIND FLOW. DVORAK ANALYSIS BASED ON 1.0 WRAP WITH WHITE
BAND YIELDS DT=4.0, MET AND PT AGREE. FT BASED ON DT. THUS YIELDING
T4.0/4.0/D1.5/24HRS.
FORECASTS :
AT 12 HRS VALID AT 170000 UTC 17.5S 172.0W MOV ENE AT 08KT WITH 65KT
CLOSE TO CENTRE.
AT 24 HRS VALID AT 171200 UTC 17.3S 170.9W MOV ENE AT 06KT WITH 70KT
CLOSE TO CENTRE.
OUTLOOK:
AT 36 HRS VALID AT 180000 UTC 17.2S 170.4W MOV E AT 03KT WITH 75KT
CLOSE TO CENTRE.
AT 48 HRS VALID AT 181200 UTC 17.4S 170.7W MOV SE AT 02KT WITH 80KT
CLOSE TO
CENTRE.
THE NEXT TROPICAL DISTURBANCE ADVISORY ON TROPICAL CYCLONE WINSTON
WILL BE ISSUED AT OR AROUND 162000 UTC.
TROPICAL DISTURBANCE ADVISORY NUMBER A10 ISSUED FROM RSMC NADI
Feb 121345 UTC.
SEVERE TROPICAL CYCLONE WINSTON CENTRE 950HPA CATEGORY 4 WAS LOCATED
NEAR 19.7S 171.4E AT 121200 UTC. POSITION GOOD BASED ON HR MTSAT IR
IMAGERY AND SURFACE OBSERVATIONS. CYCLONE MOVING SOUTH AT ABOUT 07
KTS. MAXIMUM 10 MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT
ABOUT 90 KNOTS.
EXPECT WINDS OVER 63 KNOTS WITHIN 25 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 47 KNOTS WITHIN 40 NAUTICAL MILES OF CENTRE.
EXPECT WINDS OVER 33 KNOTS WITHIN 120 NAUTICAL MILES IN E SEMICIRCLE,
WITHIN 080 NAUTICAL MILES IN W SEMICIRCLE.
EYE WELL DEFINED. EYE WARMING AND CLOUD TOPS COOLING PAST 6 HOURS.
ORGANIZATION GOOD. SST AROUND 31 DEGREES CELSIUS. SYSTEM LIES UNDER A
STRONG UPPER DIVERGENCE REGION IN A LOW TO MODERATE SHEARED
ENVIRONMENT. OUTFLOW GOOD. SYSTEM TRACKING ALONG THE WESTERN
PERIPHERY OF THE SUB-TROPICAL RIDGE LOCATED TO THE EAST. DVORAK
ANALYSIS BASED ON EYE PATTERN, OW EYE SURROUNDED BY W IN CMG RING
WITH EYE ADJUSTMENT YIELDS DT=6.5. MET=5.0 AND PT=5.5.FT BASED ON PT
THUS, YIELDING T5.5/5.5/D2.0/24HRS.
FORECASTS :
AT 12 HRS VALID AT 130000 UTC 22.0S 171.7E MOV S AT 12KT WITH 100KT
CLOSE TO CENTRE.
AT 24 HRS VALID AT 131200 UTC 24.1S 172.8E MOV SSE AT 11KT WITH 95KT
CLOSE TO CENTRE.
OUTLOOK:
AT 36 HRS VALID AT 140000 UTC 25.2S 174.6E MOV SE AT 10KT WITH 90KT
CLOSE TO CENTRE.
AT 48 HRS VALID AT 141200 UTC 25.0S 176.5E MOV ESE AT 10KT WITH 85KT
CLOSE TO
CENTRE.
THE NEXT TROPICAL DISTURBANCE ADVISORY ON TROPICAL CYCLONE WINSTON
WILL BE ISSUED AT OR AROUND 122000 UTC.
