Tropical Cyclone Raquel

[Nev]

Thought this probably deserved a thread (even if it's a short one), just because of how unusual this TC is. TC Raquel near the Solomon Islands was named by TCWC Brisbane at about 6am NZST yesterday morning. This is the first ever TC to be named off the east coast of Australia in July and only the second named TC to have occurred in the region during winter, the other being TC Ida (May 29 to June 3, 1972). There was also TC Lindsay off the west coast of Australia in July 1996. Also, (like TC Pam & TS Bavi) almost identical Tropical Storm Chan-Hom has been developing on the other side of the equator.

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by BRISBANE TROPICAL CYCLONE WARNING CENTRE
at: 1852 UTC 01/07/2015
Name: Tropical Cyclone Raquel
Identifier: 01U
Data At: 1800 UTC
Latitude: 7.1S
Longitude: 159.1E
Location Accuracy: within 30 nm [55 km]
Movement Towards: south [180 deg]
Speed of Movement: 1 knot [1 km/h]
Maximum 10-Minute Wind: 45 knots [85 km/h]
Maximum 3-Second Wind Gust: 65 knots [120 km/h]
Central Pressure: 990 hPa
...
REMARKS:
Strong east-northeast vertical wind shear has continued to limit any further
development of tropical cyclone Raquel overnight. The CIMMS vertical wind shear
product continues to show that the wind shear is approximately 20-30 knots in
strength. Convection has been confined primarily to the west and south of the
system due to the vertical wind shear and as a result parts of the Solomon
Islands have experienced heavy rain for much of the night, which would increase
the risk of flash flooding and/or landslides.

Convection has started to build back closer to the estimated low level centre
overnight and as a result the latest Dvorak analysis was based on a shear
pattern with the low level centre located one-third of a degree into the deep
convection, giving a DT of 3.5. MET and PAT were both 3.0. The FT was based on
MET. The location of the system is rated as fair given the recent SSMI microwave
data at 1611UTC.

The strong east-northeast wind shear should continue to constrain development
this morning. However, satellite imagery shows that a poleward outflow channel
is starting to develop due to an upper trough moving eastwards across the Coral
Sea, which may allow for some intensification late today or during Thursday. It
is for this reason the system is still forecast to possibly reach category 2
strength by early Thursday.

Tropical cyclone Raquel should continue moving in a general southwards direction
today under the influence of a mid-level ridge situated to the east of the
Solomon Islands. The movement of the system is expected become slow moving by
Friday as this steering influence breaks down with the approach of the upper
trough moving eastwards across the Coral Sea. Computer model guidance greatly
varies in the direction the system will take once this steering influence
weakens.

[Razor]

On top of that the poor buggers just had a sizeable 5.8 shallow earthquake too. The Solomons deserve a break

[Nev]

Looks like Raquel might be a 'gone-burger'...
LLCC was exposed this morn and convection has been completely displaced towards the SW.

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by BRISBANE TROPICAL CYCLONE WARNING CENTRE
at: 0042 UTC 02/07/2015
Name: Tropical Cyclone Raquel
Identifier: 01U
Data At: 0000 UTC
Latitude: 6.6S
Longitude: 159.6E
Location Accuracy: within 20 nm [35 km]
Movement Towards: east northeast [063 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 35 knots [65 km/h]
Maximum 3-Second Wind Gust: 50 knots [95 km/h]
Central Pressure: 998 hPa
...
REMARKS:
Tropical cyclone Raquel has significantly weakened this morning with the latest
visible satellite imagery clearly showing the displacement of the deep
convection from the low level centre. The CIMMS vertical wind shear product
indicates that approximately 20-30 knots of east-northeast shear exists across
the system. Convection has been primarily confined to the south of the system
this morning due to the wind shear and as a result parts of the Solomon Islands
experienced heavy rain for much of last night.

The latest Dvorak analysis was based on a shear pattern with the low level
centre located 1.25 degrees away from the deep convection, giving a DT of 2.0.
MET and PAT were 1.5 and 2.0 respectively. The FT of 2.5 was based on DT, though
constrained by the Dvorak rules. CI was maintained at 3.0 for initial weakening.
The location of the system is rated as good to fair.

The strong east-northeast wind shear should continue to constrain development
today and could even lead to the system falling below tropical cyclone strength.
Satellite imagery shows that a poleward outflow channel is starting to develop
due to an upper trough moving eastwards across the Coral Sea. This increased
outflow to the south may allow the system to maintain its category 1 strength
into Friday, but this would require convection to reform near the centre.

Tropical cyclone Raquel is now expected to move in more of an eastwards
direction today. This change in forecast is due to the expectation that the
system will move with the background westerly flow since it is now a much more
shallow system than what the computer model guidance is depicting. It is
anticipated that the system could adopt more of a southwards track tonight if it
begins to be steered by the mid-level flow, but this would be highly dependent
on the system redeveloping a circulation to depth once again.

[Nev]

Not surprisingly, Ex-TC Raquel downgraded by the BoM this arvo…

TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by BRISBANE TROPICAL CYCLONE WARNING CENTRE
at: 0716 UTC 02/07/2015
Name: Ex-Tropical Cyclone Raquel
Identifier: 01U
Data At: 0600 UTC
Latitude: 6.4S
Longitude: 160.0E
Location Accuracy: within 30 nm [55 km]
Movement Towards: east northeast [066 deg]
Speed of Movement: 4 knots [8 km/h]
Maximum 10-Minute Wind: 30 knots [55 km/h]
Maximum 3-Second Wind Gust: 45 knots [85 km/h]
Central Pressure: 1000 hPa
...
REMARKS:
Ex-Tropical cyclone Raquel has significantly weakened with an exposed low level
circulation centre [LLCC] clearly visible on the satellite imagery all day. The
CIMMS vertical wind shear remains around 20-30 knots of east-northeast across
the system. Convection has been well away from the centre to the south of the
system.

The latest Dvorak analysis indicated difficulty in obtaining DT as the pattern
was based on exposed LLCC. MET=1.5 adjusted to 2.0 using PT, giving a FT=2.0. CI
was still kept at 2.5.

Ex-Tropical cyclone Raquel is moving in an eastwards direction but is expected
to turn towards the south in 24 hours and then towards west later. The strong
east-northeast wind shear should continue to constrain development in the short
term. An upper trough moving eastwards across the Tasman Sea may increase the
outflow to the south by Saturday, hence leading to possibly some redevelopment.