(1) AN AREA OF CONVECTION (REMNANTS OF TC 17P) HAS PERSISTED
NEAR 19.5S 158.2E APPROXIMATELY 470 NM WEST-NORTHWEST OF NOUMEA, NEW
CALEDONIA, AND HAS TRACKED SOUTHWARD AT 09 KNOTS OVER THE PAST SIX
HOURS. RECENT ANIMATED SATELLITE IMAGERY SHOWS FLARING CONVECTION
ALONG THE NORTHEASTERN PERIPHERY OF A WEAK LOW LEVEL CIRCULATION
CENTER. A 261656Z AMSU-B 89GHZ MICROWAVE IMAGE SHOWS DIMINISHED DEEP
CONVECTION WITH LOW LEVEL BANDING WRAPPING INTO THE CENTER. UPPER
LEVEL ANALYSIS INDICATES THE LOW LEVEL CIRCULATION CENTER LIES
WITHIN A FAVORABLE ENVIRONMENT WITH LOW TO MODERATE (10 TO 20 KNOT)
VERTICAL WIND SHEAR. SEA SURFACE TEMPERATURES ARE FAVORABLE FOR
INTENSIFICATION WITH TEMPERATURES OF 26-28C. MODERATE OUTFLOW ALOFT
IS SUPPORTING CONVECTION. MODELS ARE IN GOOD AGREEMENT ON
REINTENSIFICATION OF SYSTEM AROUND TAU 24-36 WITH GALE FORCE WINDS.
HOWEVER, MODELS INDICATE AN EXPANSIVE WIND FIELD AWAY FROM THE
CENTER, WHICH SUGGESTS THE SYSTEM MAY HAVE SUBTROPICAL
CHARACTERISTICS WHEN IT REGENERATES. THE POTENTIAL FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS LOW.
Tropical Cyclone Outlook for Coral Sea
Issued at 2:30 pm EST on Tuesday 27 March 2018
for the period until midnight EST Friday 30 March 2018.
Existing Cyclones in the Eastern Region:
None.
Potential Cyclones:
Ex-tropical cyclone Iris is located to the northwest of New Caledonia and is expected to continue to move southwards for the rest of today. On Wednesday, this system is forecast to stall before moving northwestwards on Thursday.
While this system has a low chance of redeveloping into a tropical cyclone, it is expected to remain offshore of the the Queensland coast for the next three days.
Likelihood of a tropical cyclone in the Eastern Region on:
Wednesday:Very low
Thursday: Low
Friday: Low
(1) THE AREA OF CONVECTION (REMNANTS OF TC 17P) PREVIOUSLY
LOCATED NEAR 16.1S 150.8E, IS NOW LOCATED NEAR 14.9S 149.6E,
APPROXIMATELY 250 NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA. ANIMATED
ENHANCED INFRARED SATELLITE IMAGERY AND A 311159Z AMSU-B 89GHZ IMAGE
SHOW A FULLY EXPOSED, WELL DEFINED LOW LEVEL CIRCULATION CENTER WITH
LIMITED FLARING CONVECTION DISPLACED TO THE PERIPHERY IN THE NORTH.
A 311200Z ASCAT PASS SHOWS A BROAD SWATH OF 20 KT WINDS ENCIRCLING
THE DISTURBANCE, AND PATCHES OF 25 KT WINDS TO THE SOUTH OF THE
CENTER. THE DISTURBANCE IS CURRENTLY LOCATED IN A MARGINAL
ENVIRONMENT, WITH LIMITED DIVERGENCE ALOFT, AND AN AREA OF
CONVERGENCE TO THE SOUTH SUPPRESSING CONVECTION, AND MODERATE TO
HIGH VERTICAL WIND SHEAR (15-30 KNOTS). HOWEVER, SEA SURFACE
TEMPERATURES (28-30 CELSIUS) ARE WARM. THE SYSTEM IS CURRENTLY
ASSESSED AS SUBTROPICAL DUE TO ITS EXPANSIVE BUT CONTRACTING WIND
FIELD AND AN AMSU RADIAL CROSS-SECTION DEPICTING A COLD OVER WARM
OVER COLD ANOMALY PATTERN. HOWEVER, THE TOTAL PRECIPITABLE WATER
CONTENT HAS BEEN INCREASING OVER RECENT HOURS IN THE CENTER OF THE
DISTURBANCE, WHICH COULD BE INDICATIVE OF INCREASING TROPICAL
CHARACTERISTICS. IN THE NEAR TERM, GLOBAL MODELS AGREE THAT THE
REMNANTS OF 17P WILL TRACK SOUTHEASTWARD. HOWEVER, AFTER SEVERAL
DAYS, THERE IS SIGNIFICANT SPREAD IN THE MODEL GUIDANCE; SOME DEPICT
MODERATE DEVELOPMENT IN LATER TAUS, WHILE OTHER MODELS MAINTAIN THE
SYSTEM AROUND 34 KTS OF WIND SPEED. ADDITIONALLY, A COMPLICATED
STEERING ENVIRONMENT MAKES THE PREDICTED DIRECTION OF MOVEMENT
UNCLEAR AFTER SEVERAL DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE
ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED
TO BE NEAR 999 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO
MEDIUM.
THE AREA OF CONVECTION (REMNANTS OF TC 17P) PREVIOUSLY
LOCATED NEAR 14.5S 148.4E, IS NOW LOCATED NEAR 15.6S 149.1E,
APPROXIMATELY 210 NM EAST-NORTHEAST OF CAIRNS, AUSTRALIA. ANIMATED
MULTI-SPECTRAL SATELLITE IMAGERY AND A 312348Z MHS 89GHZ IMAGE SHOW
A BROAD LOW LEVEL CIRCULATION CENTER WITH INCREASING AMOUNTS OF
PERSISTENT CONVECTION AND IMPROVING LOW LEVEL BANDING EASILY
DISCERNABLE IN THE IMAGES. A 312349Z ASCAT PARTIAL PASS SHOWS A
BROAD SWATH OF PRIMARILY 20-25 KNOT WINDS ENCIRCLING THE
DISTURBANCE, WITH PATCHES OF 30 KNOT WINDS TO THE SOUTH. THE
DISTURBANCE IS CURRENTLY LOCATED IN A FAIR ENVIRONMENT, WITH LIMITED
DIVERGENCE ALOFT AND A NARROW RIBBON OF FAVORABLE VERTICAL WIND
SHEAR SURROUNDED BY HIGHER (20-30 KNOTS) VALUES. SEA SURFACE
TEMPERATURES (28-30 CELSIUS) ARE FAVORABLE. THE REMNANTS OF 17P HAVE
GRADUALLY BEEN TRANSITIONING FROM A SUB-TROPICAL STRUCTURE BACK TO
TROPICAL, WITH FLORIDA STATE UNIVERSITY(FSU) PHASE SPACE DIAGRAM
INDICATING A DEEPENING WARM CORE. THE TOTAL PRECIPITABLE WATER
CONTENT HAS BEEN INCREASING OVER RECENT HOURS IN THE CENTER OF THE
DISTURBANCE. AS THE SYSTEM TRACKS FURTHER SOUTHWARD THE ENVIRONMENT
IS EXPECTED TO BECOME MORE FAVORABLE. GLOBAL MODELS AGREE THAT THE
REMNANTS OF 17P WILL BEGIN TO TRACK SOUTHWARD, WITH MOST MODELS
SHOWING FURTHER INTENSIFICATION OVER THE NEXT FEW DAYS. MAXIMUM
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 KNOTS. MINIMUM SEA
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR
THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24
HOURS IS HIGH.
IDQ20065
Australian Government Bureau of Meteorology
Queensland Region
Tropical Cyclone Warning Centre
TROPICAL CYCLONE INFORMATION BULLETIN
For 11:16 am EST on Monday 2 April 2018
At 10 am AEST Monday, Tropical Cyclone Iris (Category 1) with central pressure
995 hPa was located over the Coral Sea
near latitude 16.9 south longitude 148.7 east, which is about 310 km east of
Cairns and 330 km northeast of Townsville.
The cyclone is moving southwest at 13 kilometres per hour.
Tropical cyclone Iris has redeveloped in the Coral Sea off the tropical
Queensland coast.
Tropical cyclone Iris is expected to continue moving southwest for most of the
day today, before becoming slow moving tonight. On Tuesday the system is
expected to turn east and move away from the Queensland coast. It may develop
further, but is not expected to cross the Queensland coast.
Damaging wind gusts and heavy rainfall are possible about coastal and island
areas between about Rollingstone and Sarina as the cyclone makes its closest
approach to the coast. A severe weather warning is current for these
conditions; refer to that product for more information.
The next Information Bulletin will be issued by 5 pm AEST today.
