• Aust: TC Seroja 061328

    From Weather Alert@1:2320/105 to All on Tue Apr 6 16:27:00 2021
    AXAU01 APRF 061328
    IDW27600
    TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - WESTERN REGION
    Issued by AUSTRALIAN BUREAU OF METEOROLOGY TROPICAL CYCLONE WARNING CENTRE
    at: 1328 UTC 06/04/2021

    Name: Tropical Cyclone Seroja
    Identifier: 22U
    Data At: 1200 UTC
    Latitude: 11.9S
    Longitude: 119.2E
    Location Accuracy: within 45 nm [85 km]
    Movement Towards: southwest [222 deg]
    Speed of Movement: 5 knots [9 km/h]
    Maximum 10-Minute Wind: 40 knots [75 km/h]
    Maximum 3-Second Wind Gust: 55 knots [100 km/h]
    Central Pressure: 991 hPa
    Radius of 34-knot winds NE quadrant: 70 nm [130 km]
    Radius of 34-knot winds SE quadrant: 60 nm [110 km]
    Radius of 34-knot winds SW quadrant: 60 nm [110 km]
    Radius of 34-knot winds NW quadrant: 60 nm [110 km]
    Radius of 48-knot winds NE quadrant:
    Radius of 48-knot winds SE quadrant:
    Radius of 48-knot winds SW quadrant:
    Radius of 48-knot winds NW quadrant:
    Radius of 64-knot winds:
    Radius of Maximum Winds: 20 nm [35 km]
    Dvorak Intensity Code: T2.5/3.0/S0.0/24HRS STT:W0.5/06HRS
    Pressure of outermost isobar: 1004 hPa
    Radius of outermost closed isobar: 120 nm [220 km]

    FORECAST DATA
    Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
    [UTC] : degrees : nm [km]: knots[km/h]: hPa
    +06: 06/1800: 12.4S 118.7E: 060 [110]: 040 [075]: 994
    +12: 07/0000: 12.8S 118.0E: 065 [125]: 040 [075]: 994
    +18: 07/0600: 13.4S 117.2E: 075 [135]: 040 [075]: 994
    +24: 07/1200: 14.0S 116.5E: 085 [155]: 040 [075]: 994
    +36: 08/0000: 15.0S 114.7E: 100 [190]: 040 [075]: 994
    +48: 08/1200: 16.2S 113.3E: 130 [235]: 045 [085]: 991
    +60: 09/0000: 17.6S 112.1E: 155 [285]: 050 [095]: 988
    +72: 09/1200: 18.8S 111.1E: 175 [330]: 055 [100]: 982
    +96: 10/1200: 21.6S 109.6E: 240 [445]: 065 [120]: 973
    +120: 11/1200: 25.6S 111.3E: 275 [510]: 050 [095]: 984

    REMARKS:
    Tropical Cyclone Seroja is tracking towards the southwest, away from the Indonesian archipelago. Latest IR imagery shows deep convection has reduced and is now displaced to the northeast, partially exposing the LLCC.

    Dvorak analysis: FT=2.5 based on MET with a W- 24hr trend. Unable to apply DT due to a shear pattern with weak T gradient. CI held higher at 3.0. ADT estimates have decreased to 2.3. No recent SATCON data is available. Final intensity 40 knots.

    The impact of SE wind shear and dry air in the mid levels is likely to persist in the next 24-36h and some further weakening is possible although the forecast maintains intensity at 40kn through this period. Beyond that the shear will become more NE'ly without intrusion of dry air permitting a resumption of intensification. Model guidance of intensity varies significantly but a category 3 system remains a possibility.

    Steady southwest movement is forecast as the mid-level ridge strengthens to the south through 72-96h. Sea surface temperatures are much warmer than normal along the forecast track and extending a long way south

    Interaction with another tropical system to the west [23U] results in a high level of uncertainty for the extended forecast track and intensity. The most likely scenario takes the track to the south then turning towards the west
    c oast of WA by 120h.

    Copyright Commonwealth of Australia
    ==
    The next bulletin for this system will be issued by: 06/1930 UTC.
    &&
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