TYPHOON NANGKA PUBLIC ADVISORY NUMBER 18
WIKI-HURRICANES FORECASTING CENTER
12:00 AM JST WED JUL 08 2015
...NANGKA ALMOST A SUPER TYPHOON...
SUMMARY OF 12:00 AM JST...15:00 UTC...INFORMATION
CENTER POSITION CONFIDENCE: VERY HIGH
ABOUT 630 MI...1,010 KM ESE OF SAIPAN, MARIANA ISLANDS
MAXIMUM SUSTAINED WINDS...125 KT...145 MPH...230 KM/H
MINIMUM BAROMETRIC PRESSURE...927 MB...27.34 INCHES
PRESENT MOVEMENT...W AT 8 KT...10 MPH...17 KM/H
DISCUSSION AND 48-HOUR OUTLOOK
At 12:00 am JST, the center of Typhoon Nangka was situated near 14.0N 153.1E, or about 635 miles (1,020 km) east-southeast of Saipan, Mariana Islands. Maximum sustained winds were 125 knots (145 mph, 230 km/h), with higher gusts. The minimum barometric pressure was 927 millibars (hPa; 27.34 inHg), and the cyclone was tracking west at 8 knots (10 mph, 17 km/h). Some fluctuations in intensity are expected during the next day or so.
Next complete advisory at 6:00 am JST.
TYPHOON NANGKA DISCUSSION NUMBER 17
WIKI-HURRICANES FORECASTING CENTER
6:00 PM JST TUE JUL 07 2015
Typhoon Nangka has leveled off in intensity. A WMG eye is still visible on Dvorak IR, though a littl less defined than earlier and the eye has cooled and was likely the warmest at around 10z at around 18C. Cloud tops remain roughly the same from six hours ago, but they may have warmed slightly. In addition, the western side of the storm is not as well orgnaixed on visible imagery, indicated the shear may have increased some. CI values from WFHC and SAB are still T6.5/127 knts and ADt fixes has not changed much, with the JTWC SSD ADT at T6.8/132 knts and CMISS ADT is still at T6.5/127 knts, so the intensity remains 125 knts, though the storm could have been 130 knts 4-5 hours ago.
Maps from UW-CIMSS indicate that Nangka is approaching a region of increased vertical wind shear on the order of 15 to 25 knots courtesy of an upper-level trough to the cyclone's north and west. However, the flow around the trough becomes more divergent aloft as it approaches Nangka, suggesting that conditions may not be quite as unfavorable as they otherwise would be. It appears that the shear may already be affecting this system as I am not too harpy about how weird the west side looks. As such, only slow intensification is shown through day 2. Thereafter, inner core dynamics such as eyewall replacement cycles could cause for slight weakening before subsequent re-intensification. Later in the period, the approach of an upper-level trough from the north may impart stronger shear.
Nangka is currently tracking swiftly west-northwest (save a recent westerly wobble) under the influence of a strong mid-level ridge across the northern West Pacific. This setup is expected to remain in place for the next three days. Thereafter, the aforementioned upper-level trough is expected to erode the western periphery of the ridge and cause Nangka to turn more poleward at a slower rate. Both the GFS and ECMWF remain in generally good agreement throughout the forecast period, and the updated track forecast is merely updated from the previous. On its current path, Nangka is expected to pose a substantial threat to the northern and central Mariana Islands, and residents there should prepare for potentially life-threatening conditions.
INIT 07/1500Z 14.0N 153.1E 125 KT 145 MPH
12H 08/0000Z 14.7N 151.4E 130 KT 150 MPH
24H 08/1200Z 15.4N 149.4E 135 KT 155 MPH
36H 09/0000Z 16.1N 147.4E 140 KT 160 MPH
48H 09/1200Z 17.1N 145.9E 140 KT 160 MPH...NEAR NORTHERN MARIANA ISLANDS
72H 10/1200Z 19.8N 143.6E 135 KT 155 MPH
96H 11/1200Z 21.1N 141.8E 125 KT 145 MPH
120H 12/1200Z 23.3N 139.7E 115 KT 130 MPH