JTWC Issues Tropical Cyclone Formation Alert for Developing Tropical Disturbance East Southeast of Guam


Guam – The Joint Typhoon Warning Center [JTWC] in Honolulu has issued a  Tropical Cyclone Formation Alert for the developing tropical disturbance east southeast of Guam.  


READ the JTWC Alert below:

Joint Typhoon Warning Center Pearl Harbor Hawaii – Tropical Cyclone Formation Alert

1. Formation of a significant Tropical Cyclone is possible within 170 nm either side of a line from 13.7n 147.8e to 10.7n 141.6e within the next 06 to 24 hours. 

Available data does not justify issuance of numbered Tropical Cyclone Warnings at this time.

Winds in the area are estimated to be 18 to 23 knots. Metsat imagery at 151932z indicates that a circulation center is located near 13.0n 146.5e. the system is moving southwestward at 11 knots.

2. Remarks: The area of convection previously located near 14.3N 148.5E is now located near 13.0N 146.5E, approximately 107 NM east-southeast of Guam. 

Recent animated infrared satellite imagery indicates developing deep convection associated with a consolidated low-level circulation center (llcc). A 151633z amsu-b microwave  image reveals persistent convection that has deepened with a slight curvature along the southern semi-circle. A 151152z ascat pass
depicted a 20 knot elongated circulation located slightly norheast of guam. 161958z observations in Guam have indicated pressures dropping over the past 24 hours to 1005.8 hpa with 20-24 knot winds. 

The disturbance currently lies equatorward of an upper-level ridge axis, in an area of moderate northeasterly vertical wind shear. 

Maximum sustained surface winds are estimated at 18 to 23 knots.  

Minimum sea level pressure is estimated to be near 1006 mb. Due to the increased consolidation of the llcc, the potential for development of a significant tropical cyclone within the next 24 hours is high.

3. This alert will be reissued, upgraded to warning or cancelled by 162100z.