SPC : TROPICAL DEPRESSION 12F (96P)

[cycloneye]

[cycloneye]

AN AREA OF CONVECTION HAS PERSISTED NEAR 16.3S 157.7E,
APPROXIMATELY 605 NM WEST-NORTHWEST OF NOUMEA, NEW CALEDONIA.
ANIMATED MULTISPECTRAL IMAGERY SHOWS A BROAD CIRCULATION EMBEDDED IN
A SEGMENT OF THE MONSOON TROUGH STRETCHING FROM THE GULF OF
CARPENTARIA TO NEW CALEDONIA. THIS IS EVIDENT ON A 062235Z ASCAT
SCATTEROMETRY IMAGE DEPICTING AN ELONGATED CIRCULATION CENTER WITH
10-15 KNOT WINDS. CONVECTION ABOUND ALONG THE TROUGH WITH FORMATIVE
BANDING TO THE NORTH OF THE DISTURBANCE. LOW LEVEL STREAMLINE
ANALYSIS SHOWS AN EXTENSIVE SOUTHEASTERLY WIND FIELD TO THE SOUTH AND
NORTHWESTERLY WINDS TO THE NORTH OF THE SYSTEM. UPPER LEVEL ANALYSIS
INDICATES THE AREA IS UNDER A DIVERGENT ZONE WITH LOW TO MODERATE
VERTICAL WIND SHEAR, JUST TO THE SOUTH OF A RIDGE AXIS. NUMERICAL
MODELS INCLUDING NOGAPS, GFS, AND ECMWF SUPPORT DEVELOPMENT OF A
CYCLONE IN THIS AREA WITH NOGAPS BEING THE MOST AGGRESSIVE IN TERMS
OF INTENSITY. SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB.
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS POOR.

[cycloneye]

Looks better organized.

[cycloneye]

Upgraded to Fair

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 16.3S
157.7E, IS NOW LOCATED NEAR 16.2S 163.4E, APPROXIMATELY 210 NM EAST-
NORTHEAST OF VANUATU. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS
INCREASED DEEP CONVECTION BUILDING OVER AN INCREASINGLY ORGANIZED
LOW LEVEL CIRCULATION CENTER. RECENT MICROWAVE IMAGERY INDICATES
IMPROVED LOW LEVEL BANDING WITH A MAJORITY OF THE DEEP CONVECTION
ALONG THE EASTERN SEMI-CIRCLE. ANIMATED WATER VAPOR IMAGERY DEPICTS
FAVORABLE EQUATORWARD OUTFLOW AND INCREASINGLY FAVORABLE POLEWARD
OUTFLOW ASSOCIATED WITH A TRANSITORY UPPER LEVEL TROUGH. UPPER LEVEL
ANALYSIS REVEALS THE SYSTEM IS SLIGHTLY SOUTH OF THE RIDGE AXIS IN A
REGION OF HIGHLY DIFFLUENT FLOW. HIGH VERTICAL WIND SHEAR (25 TO 35
KNOTS) IS CAUSING CONVECTION TO BE SHEARED TOWARD THE EAST. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. DUE TO THE INCREASED
LOW LEVEL ORGANIZATION AND A HIGHLY FAVORABLE OUTFLOW PATTERN, THE
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE
WITHIN THE NEXT 24 HOURS IS UPGRADED TO FAIR.

[Grifforzer]

AXAU21 ABRF 071846
IDQ20018
TROPICAL CYCLONE TECHNICAL BULLETIN: AUSTRALIA - EASTERN REGION
Issued by BRISBANE TROPICAL CYCLONE WARNING CENTRE
at: 1846 UTC 07/03/2011
Name: Tropical Low
Identifier: 21U
Data At: 1800 UTC
Latitude: 15.7S
Longitude: 159.8E
Location Accuracy: within 90 nm [165 km]
Movement Towards: east [082 deg]
Speed of Movement: 11 knots [20 km/h]
Maximum 10-Minute Wind: 25 knots [45 km/h]
Dvorak Intensity Code: T1.5/1.5/D1.0/24HRS
Pressure of outermost isobar: 1006 hPa
Radius of outermost closed isobar: 150 nm [280 km]
Storm Depth: Shallow
FORECAST DATA
Date/Time : Location : Loc. Accuracy: Max Wind : Central Pressure
[UTC] : degrees : nm [km]: knots[km/h]: hPa
+12: 08/0600: 16.1S 162.7E: 120 [220]: 030 [055]: 1002
+24: 08/1800: 17.0S 165.2E: 150 [280]: 030 [055]: 1002
+36: 09/0600: 18.2S 168.3E: 180 [340]: 035 [065]: 998
+48: 09/1800: 19.7S 170.7E: 215 [400]: 035 [065]: 997
+60: 10/0600: 21.1S 171.9E: 260 [485]: 040 [075]: 991
+72: 10/1800: 22.2S 172.4E: 310 [580]: 040 [075]: 991
REMARKS:
Location from IR and microwave is poor. Little discernable organization at the
moment with lack of deep convection near LLCC. System in a low to moderate shear
environment but in a strong upper divergent flow. Deep moist inflow to the
northeast, ensure that the system likely to intensify. System expected to move
east-northeast due to deep southwesterly caused by an upper trough to the south.

[Grifforzer]

Gale Warning 11 ISSUED FROM RSMC NADI Mar 08/0039 UTC 2011 UTC.

TROPICAL DEPRESSION 12F [1004hPa] CENTRE WAS LOCATED NEAR 16.1S 162.8E AT
080000UTC. POSITION POOR. DEPRESSION MOVING TOWARDS THE EAST AT 13 KNOTS.

EXPECT NW/NE WINDS OF 35 KNOTS TO DEVELOP WITHIN 180 NAUTICAL MILES OF THE
CENTRE IN THE NE QUADRANT WITHIN THE NEXT 6 TO 12 HOURS.

THIS IS THE FIRST WARNING FOR THIS SYSTEM.

[HURAKAN]

Tropical Disturbance Summary For area Equator to 25S, 160E to 120W
ISSUED FROM RSMC NADI Mar 07/2255 UTC 2011 UTC.

TROPICAL DISTURBANCE CENTRE [1004HPA] ANALYSED NEAR 16.0S 161.3E AT
071800UTC MOVING EAST AND DEVELOPING. SYSTEM LIES TO THE NORTH OF AN
AMPLIFYING UPPER TROUGH IN A LOW TO MODERATELY SHEARED ENVIRONMENT.
SST IS AROUND 29 TO 30 DEGREES. GLOBAL MODELS ARE DEVELOPING THE
SYSTEM AND ARE GENERALLY MOVING IT TOWARDS THE EAST TO SOUTHEAST.
POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 24 TO 48 HOURS IS MODERATE.

[HURAKAN]

Latest

[HURAKAN]

Tropical Disturbance Summary For area Equator to 25S, 160E to 120W
ISSUED FROM RSMC NADI Mar 08/0930 UTC 2011 UTC.

TROPICAL DEPRESSION TD12F CENTRE [1000HPA] ANALYSED NEAR 16.9S 164.9E
AT 080600UTC. POSITION POOR.
TD12F MOVING EAST SOUTHEAST AT 16 KNOTS AND DEVELOPING.
SST IS AROUND 29 TO 30 DEGREES.
SYSTEM LIES TO THE NORTH OF AN AMPLIFYING UPPER TROUGH IN A LOW TO
MODERATELY SHEARED ENVIRONMENT.
GLOBAL MODELS ARE DEVELOPING THE SYSTEM AND ARE GENERALLY MOVING IT
TOWARDS THE EAST SOUTHEAST.

POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 12 TO 24 HOURS IS HIGH.

[Grifforzer]

Tropical Disturbance Summary For area Equator to 25S, 160E to 120W
ISSUED FROM RSMC NADI Mar 08/2302 UTC 2011 UTC.

TROPICAL DEPRESSION TD12F CENTRE [1001HPA] ANALYSED NEAR 19.3S 171.6E
AT 082100UTC. POSITION POOR BASED ON MTSAT IR/VIS IMAGERY AND SURFACE
OBSERVATIONS. TD12F MOVING EAST-SOUTHEAST AT ABOUT 20 KNOTS.SST IS
AROUND 28 DEGREES.

ORGANISATION REMAINS POOR. CONVECTION HAS DECREASED PAST 12 HOURS.
SYSTEM LIES TO THE EAST OF AN UPPER TROUGH IN A MODERATE TO HIGH
SHEARED ENVIRONMENT. SYSTEM IS BEING STEERED SOUTHEAST BY
NORTHWESTERLY DEEP LAYER MEAN WIND.

GLOBAL MODELS ARE MOVING TD12F SOUTHEAST WITH SOME MODELS SLIGHTLY
INTENSIFYING THE SYSTEM.

POTENTIAL FOR THIS SYSTEM TO DEVELOP INTO A TROPICAL CYCLONE IN THE
NEXT 24 TO 48 HOURS IS LOW TO MODERATE.