APCEDI ALERT 09F/08F #4, 2005: Two Tropical Systems cause Warnings and Watches over 5 Countries

Cyclone Nancy (09F) and Tropical Depression 08F are affecting a wide area of the South Pacific, and as a result 5 countries have issued a variety of warnings and watches as noted below:

COOK ISLANDS:
A STRONG WIND WARNING IS NOW CURRENT FOR PUKAPUKA, NASSAU AND SUWARROW.

SAMOA:
GALE WATCH FOR ALL AREAS.

AMERICAN SAMOA: TUTUILA AND AUNUU:
HIGH SURF ADVISORY IN EFFECT, BUT GALE WATCH CANCELLED.

AMERICAN SAMOA:MANU'A:
HIGH SURF ADVISORY AND GALE WATCH IN EFFECT

TOKELAU
A STRONG WIND WARNING FOR ALL AREAS.

TUVALU
A STRONG WIND WARNING FOR ALL AREAS.

All concerns in Tuvalu, Fiji, Wallis and Futuna, Tokelau, Samoa, American Samoa, Niue, Cook Islands and French Polynesia should monitor these systems carefully. The presence of 2 systems in relatively close proximity to each other makes forecasting modelling for either system more difficult. Therefore, close attention should be paid to both, and local authorities should be prepared for unexpected shifts in direction of either system.

Cyclone Nancy is about 100 miles (161 km) west of Suwarrow in the Northern Cooks and is moving southeast at 6 kt. It is forecast to track generally south. On the forecast course, this system would like stay west of the main Cook Islands, but east of American Samoa and Niue. All concerns in Samoa, American Samoa, Cook Islands, Niue and French Polynesia should monitor Cyclone Nancy carefully for any unexpected changes in direction especially given the presence of System 08F to the west.

Depression 08F continues slow moving between Tuvalu and Tokelau. Models are very divergent on the future growth and direction of this system especially given the presence of Cyclone Nancy to the east. All concerns in Tuvalu, Tokelau, Wallis and Futuna, Fiji and Samoa should monitor this system closely.

FROM FIJI METEOROLOGICAL SERVICE
http://www.met.gov.fj/

CYCLONE NANCY

Tropical Disturbance Advisory Number A9 issued from RSMC NADI
Feb 13/0151 UTC 2005 UTC.

TROPICAL CYCLONE NANCY 09F CENTRE [993hPa] WAS LOCATED NEAR 12.9S 165.3W AT 130000 UTC MOVING SOUTHEAST ABOUT 06 KNOTS. POSITION POOR BASED ON GOES9/10 EIR/VIS IMAGERY WITH ANIMATION. 10-MINUTE AVERAGE WINDS ESTIMATED AT 35 KNOTS CLOSE TO CENTRE, INCREASING TO 45 KNOTS IN THE NEXT 12 TO 24 HOURS. WINDS ABOVE 33 KNOTS WITHIN 100 MILES OF CENTRE IN SECTORS FROM NORTH THROUGH EAST TO SOUTH AND WITHIN 60 MILES OF CENTRE ELSEWHERE.

NANCY IS A COMPACT SYSTEM WITH A SMALL CDO PERSISTING PAST 12 HOURS. MAIN BAND TO EAST STRUGGLING TO WRAP AROUND CDO. DIURNAL EFFECTS AND SHEAR STILL PROMINENT. CONVECTIVE TOPS WARMED SLIGHTLY PAST FEW HOURS. CONVECTION WRAPS ABOUT 0.6 ON LOG10 SPIRAL, YIELDING T3.0/3.0/D0.5/24HRS. MET=3.5. PT=3.0. NANCY REMAINS IN A REGION OF STRONG DIFFLUENCE. OUTFLOW GOOD TO NORTH AND SOUTH BUT RESTRICTED ELSEWHERE. CYCLONE STILL LIES UNDER WEAK STEERING FIELD. CONSENSUS FORECASTS AN INITIAL SOUTH TO SOUTHWEST TURN BEFORE TREKKING SOUTH-SOUTHEAST. GLOBAL MODELS GENERALLY AGREE ON FURTHER INTENSIFICATION AND FUTURE SOUTHWARD TRACK.

FORECASTS:
12HRS VALID AT 131200 UTC NEAR 13.5S 166.0W MOV SW 4KT WITH 40KT CLOSE TO CENTRE.
24HRS VALID AT 140000 UTC NEAR 14.0S 166.0W MOV SW 3KT WITH 45KT CLOSE TO CENTRE.

OUTLOOK:
36HRS VALID AT 141200 UTC NEAR 14.5S 166.3W MOV SSW 3KT WITH 50KT CLOSE TO CENTRE.
48HRS VALID AT 150000 UTC NEAR 15.4S 165.9W MOV SSW 3KT WITH 55KT CLOSE TO CENTRE.

THE NEXT TROPICAL DISTURBANCE ADVISORY ON TC NANCY WILL BE ISSUED AROUND 130800 UTC.
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TROPICAL DEPRESSION 08F

Tropical Disturbance Advisory Number B5 issued from RSMC NADI
Feb 13/0203 UTC 2005 UTC.

TROPICAL DEPRESSION 08F [1000HPA] WAS LOCATED NEAR 9.2S 178.1W AT 130000 UTC. DEPRESSION SLOW MOVING. POSITION POOR BASED ON GOES9 EIR/VIS IMAGERY WITH ANIMATION. 10-MINUTE AVERAGE WINDS ESTIMATED AT 20 TO 25 KNOTS CLOSE TO THE CENTRE.

OVERALL ORGANISATION INCREASED SIGNIFICANTLY PAST 24 HOURS. STILL DIFFICULT TO LOCATE LLCC UNDER THICK CIRRUS OUTFLOW. CONVECTION INCREASING IN ORGANISATION AND COOLING ABOUT THE CENTRAL AREA. BANDING TO NORTH DEVELOPING AND BEGINNING TO WRAP AROUND A DEVELOPING CENTRE. 08F STILL INFLUENCED BY DIURNAL EFFECTS. CONVECTION WRAPS 0.2 ON LOG10 YIELDING A DVORAK OF T1.5/1.5/D0.0/24HRS. SST AROUND 30C. 08F REMAINS IN A REGION OF STRONG DIFFLUENCE. ENVIRONMENT SHEAR IS MINIMAL AND ANTICIPATED TO DECREASE FURTHER. STEERING OVER DEPRESSION IS WESTERLY, AGAINST AVAILABLE GUIDANCE [JMA/UK], FORECASTING A SOUTHWEST TRACK WHLST NOGAPS, SOUTHEAST. GLOBAL MODELS HAVE DIFFERING OPINIONS ON 08F. ALL THREE MODELS FAVOUR FURTHER INTENSIFICATION.

THE NEXT TROPICAL DISTURBANCE ADVISORY ON 08F WILL BE ISSUED AROUND 130830 UTC.
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APCEDI will continue to monitor the progress of these tropical systems.

Kevin Vang
APCEDI Coordinator
http://www.afap.org