Earth Snapshot RSS Feed Twitter
 
 
 
 

Posts tagged Pago Pago

Tropical Cyclone Garry (10P) North of American Samoa

14.3S 170.7W

January 22nd, 2013 Category: Tropical Storms

Tropical Cyclone Garry (10P) – January 21st, 2013

Enhanced image

Track of Tropical Cyclone Garry (10P) - January 21st, 2013 © Univ. of Wisconsin

Track of TC 10P

Tropical Cyclone Garry (10P), located approximately 140 nm north of Pago Pago, American Samoa, has tracked east-southeastward at 07 knots over the past six hours. Maximum significant wave height is 16 feet.

Animated infrared satellite imagery continues to indicate slow consolidation with deep convective banding confined to the eastern semi-circle. An SSMIS 37ghz image depicts curved convective banding wrapping into the LLCC. There is fair confidence in the initial position, which is positioned on the western edge of the deep convection.

The initial intensity is assessed at 40 knots based on an average of Dvorak estimates ranging from 35 to 45 knots. Surface observations at Pago Pago remain light at 10 to 15 knots. Upper-level analysis indicates a generally favorable environment with weak northwesterly vertical wind shear and fair poleward outflow.

TC 10P is forecast to track east-southeastward under the steering influence of the low- to mid- level near-equatorial ridge through TAU 72 but should turn southeastward in the extended TAUs as the subtropical ridge builds east of the system. With the exception of NOGAPS, model guidance is in good agreement. There is high confidence in the JTWC forecast track, which is positioned faster and equatorward of the multi-model consensus. TC 10P is forecast to intensify to a peak intensity of 75 knots by TAU 72.

Tropical Cyclone 14P Tracks East-Southeastward

14.8S 160.3W

February 8th, 2010 Category: Tropical Storms

Tropical Cyclone 14P - February 7th, 2010

Tropical Cyclone 14P - February 7th, 2010

Enhanced image

Enhanced image

Track of TC 14P - February 7th, 2010 © Univ. of Wisconsin

Track of TC 14P

Tropical Cyclone 14P, located approximately 540 nautical miles east-northeast of Pago Pago, has tracked east-southeastward at 15 knots over the past six hours. Maximum significant wave height is 11 feet.

Animated multispectral satellite imagery shows improved deep convection over the last 12 hours with divergent outflow aloft. A recent TRMM microwave image, in concert with SSMIS image, shows multiple convective bands starting to wrap into the developing low level circulation center (LLCC).

Despite Dvorak estimates from ranging from 25 to 30 knots, the current intensity of 35 knots is based on the microwave signature and takes into account the small size of the system (perhaps causing erroneously low Dvorak estimates), which is embedded within the well-developed trough.

Over the next 24 to 36 hours, TC 14P will continue to track east-southeastward with the northwesterly flow on the south side of the near equatorial ridge. At the same time, the system will further consolidate and intensify due to the favorable environment.

After TAU 24, a subtropical steering ridge, currently anchored east of 120W, will gradually build westward and cause the system to make a turn toward the South. Around TAU 72, TC 14P will begin to track more westward as it remains equatorward of the subtropical ridge axis. By the end of the forecast period, the system is expected to weaken slightly as the vertical wind shear increases ahead of an approaching mid-latitude trough.

Beyond the extended TAUs, the passing trough may weaken the steering ridge and enable TC 14P to turn poleward. The early model guidance is limited and a bit spread out, though it has consistently pointed to the westward turn over the last three model runs.

Tropical Cyclone Nisha (10P) Expected to Intensify

January 29th, 2010 Category: Tropical Storms

Tropical Cyclone Nisha (10P) - January 27th, 2010

Tropical Cyclone Nisha (10P) - January 27th, 2010

Enhanced image

Enhanced image

Track of TC 10P - January 28th, 2010 © Univ. of Wisconsin

Track of TC 10P

Tropical Cyclone Nisha (10P), located approximately 450 nautical miles southeast of Pago Pago, American Samoa, has tracked eastsoutheastward at 16 knots over the past six hours. The maximum significant wave height is 13 feet.

Animated infrared imagery and a TRMM microwave image show an increase in low level organization within the past 12 hours as well as deep, convective banding wrapping into the low level circulation center (LLCC) from the east.

Upper level analysis shows the system is located just poleward of the near-equatorial ridge axis, causing moderate vertical wind shear, and that a mid-latitude trough to the southeast is currently supporting good poleward outflow.

The near-equatorial ridge is currently steering TC 10P and will continue to do so through TAU 96 when Nisha will track more south-southeastward due to a passing mid-latitude trough and subsequent reorientation of the ridge.

Additionally, Nisha will remain over warm waters (greater than 28 degrees celsius) and in favorable conditions for gradual intensification during the remainder of the forecast period. Numerical model guidance is in relatively good agreement with an east-southeastward track with the exception of the GFDN model which takes the system northward due to a forecast of weaker intensities.