WTPS12 NFFN 181800
TROPICAL DISTURBANCE ADVISORY NUMBER B23 ISSUED FROM RSMC NADI
Dec 182015 UTC.

TROPICAL CYCLONE YASA CENTRE 980HPA WAS LOCATED NEAR 20.3S 176.8W AT
181800 UTC. POSITION POOR BASED ON HIMAWARI-8 EIR IMAGERY AND
PERIPHERAL SURFACE REPORTS. CYCLONE MOVING EAST SOUTHEAST AT ABOUT
16 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED
AT ABOUT 55 KNOTS DECREASING TO 50 KNOTS BY 191200UTC.

EXPECT WINDS OVER 47 KNOTS WITHIN 55 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 55 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 50 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 35 NAUTICAL MILES IN NW QUADRANT
EXPECT WINDS OVER 33 KNOTS WITHIN 125 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 125 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 100 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 100 NAUTICAL MILES IN NW QUADRANT

DEEP CONVECTION OBSCURING LLCC. ORGANISATION POOR. TC YASA LIES JUST
TO THE EAST OF AN APPROACHING UPPER TROUGH IN A MODERATE SHEARED
ENVIRONMENT. THE UPPER TROUGH WILL BRING HIGH SHEAR OVER THE SYSTEM
WHICH WILL CAUSE FURTHER WEAKENING. YASA IS BEING STEERED
SOUTHEASTWARDS ALONG THE SOUTHERN PERIPHERY OF A NEAR EQUATORIAL
RIDGE TO THE NORTHEAST. CYCLONIC CIRCULATION EXTENDS UPTO 500HPA. SST
IS AROUND 28 DEGREES CELSIUS. DVORAK ANALYSIS BASED ON CURVED PATTERN
WITH 0.45 WRAP ON LOG YIELDS DT OF 2.5. MET 4.0 AND PT 4.0. FT BASED
ON PAT THUS, YIELDING T3.5/4.0/W1.0/24HRS.


FORECASTS :
AT 12 HRS VALID AT 190600 UTC 21.5S 177.5W MOV S AT 15 KT WITH 55 KT
CLOSE TO CENTRE

AT 24 HRS VALID AT 191800 UTC 23.1S 178.2W MOV SSW AT 13 KT WITH 45
KT CLOSE TO CENTRE

OUTLOOK :
AT 36 HRS VALID AT 206000 UTC 24.1S 179.2W MOV SSW AT 13 KT WITH 40
KT CLOSE TO CENTRE
AT 48 HRS VALID AT 201800 UTC 24.6S 179.5W MOV SSW AT 13 KT WITH 40
KT CLOSE TO CENTRE

THE NEXT TROPICAL DISTURBANCE ADVISORY ON YASA WILL BE ISSUED AROUND
190200 UTC.
--- SBBSecho 3.11-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (21:1/175)