EXTREME CLIMATIC EVENT
IAN the most powerful cyclone to hit northern islands of Tonga
Tonga has declared a state of emergency for the northern islands, after the authorities reported extensive damage to homes on Hunga.
IAN is forecast to track east of Tonga’s capital, Nuku’alofa, but could still cause large scale destruction to property and infrastructure.
FIRE-EARTH Models showed IAN had intensified to a super cyclone with sustained winds of about 235 km/h gusting to over 280 km/h at 04:20UTC on January 11, 2014.
Super Cyclone IAN. Water Vapor [FIRE-EARTH Enhancement] Satellite Image. Recorded at 03:52UTC on Saturday, January 11, 2014. Initial Image Sourced from: CIMSS/SSEC/WISC.
The FIJI Met Office has just issued the following Warning:
Special Weather Bulletin Number TWENTY EIGHT for Tonga
ON SEVERE TROPICAL CYCLONE IAN -
ISSUED FROM RSMC NADI (FIJI) – Jan 11, 2014 at 04:20UTC
TROPICAL CYCLONE WARNING.
A HURRICANE WARNING REMAINS IN FORCE FOR THE HA’APAI GROUP.
A GALE WARNING REMAINS IN FORCE FOR THE TONGATAPU GROUP BUT IS NOW
CANCELED FOR VAVAU GROUP.
A STRONG WIND WARNING REMAINS IN FORCE FOR THE REST OF TONGA.
SEVERE TROPICAL CYCLONE IAN CENTRE [935HPA] CAT 5 WAS LOCATED NEAR 19
DECIMAL 5 SOUTH 174 DECIMAL 2 WEST OR ABOUT 55 NAUTICAL MILES
SOUTH-SOUTHWEST OF VAVA’U AND 10 NAUTICAL MILES SOUTHEAST OF HA’APAI
AT [11 Jan 03:00UTC ] IAN IS CURRENTLY MOVING TOWARDS THE SOUTH-SOUTHEAST AT
ABOUT 08 KNOTS. CLOSE TO ITS CENTRE, THE CYCLONE IS ESTIMATED TO HAVE
AVERAGE WINDS UP TO ABOUT 110 KNOTS WITH MOMENTARY GUSTS TO 155
ON THIS FORECAST TRACK, THE CYCLONE IS EXPECTED TO BE LOCATED ABOUT
95 NAUTICAL MILES SOUTH-SOUTHEAST OF HA’APAI OR ABOUT 85 NAUTICAL
MILES EAST OF NUKUALOFA AT [11 Jan at 15:00UTC] AND ABOUT 140 NAUTICAL MILES
SOUTHEAST OF NUKUALOFA OR ABOUT 185 NAUTICAL MILES SOUTH-SOUTHEAST OF
HA’APAI AT [12 Jan 03:00UTC]
DESTRUCTIVE WINDS MAY BEGIN SEVERAL HOURS BEFORE THE CYCLONE CENTRE
PASSES OVERHEAD OR NEARBY.
FOR THE HA’APAI GROUP:
EXPECT VERY DESTRUCTIVE HURRICANE FORCE WINDS WITH AVERAGE SPEED OF
110 KNOTS AND MOMENTARY GUSTS TO 155 KNOTS. WINDS EXPECTED TO EASE TO
AVERAGE SPEED OF 65 KNOTS WITHIN THE NEXT 6 HOURS. HEAVY RAIN AND
SQUALLY THUNDERSTORMS. FLOODING INCLUDING SEA FLOODING OF LOW LYING
COASTAL AREAS. PHENOMENAL SEAS. DAMAGING HEAVY SWELLS.
FOR THE TONGATAPU GROUP:
EXPECT DAMAGING GALE FORCE WINDS WITH AVERAGE SPEED OF 40 KNOTS AND
MOMENTARY GUSTS TO 55 KNOTS. RAIN, HEAVY AT TIMES AND SQUALLY
THUNDERSTORMS. FLOODING INCLUDING SEA FLOODING OF LOW LYING COASTAL
AREAS. HIGH SEAS. DAMAGING HEAVY SWELLS.
FOR THE REST OF TONGA:
CLOCKWISE WINDS 20 TO 25 KNOTS, GUSTING TO 40 KNOTS. OCCASIONAL RAIN
AND SQUALLY THUNDERSTORMS. ROUGH TO VERY ROUGH SEAS. MODERATE TO
Tropical Cyclone Scales
Australian Tropical Cyclone Intensity Scale. Copyright: FIRE-EARTH Blog.
Southwest Indian Ocean
Very Intense Tropical Cyclone: sustained winds >115 kt (>212 km/h)
Intense Tropical Cyclone: sustained winds of 90–115 kt (166–212 km/h)
Tropical Cyclone: sustained winds of 64–89 kt (118–165 km/h)
Severe Tropical Storm: winds of 48–63 kt (89–117 km/h)
Moderate Tropical Storm: winds of 34–47 kt (63–88 km/h)
Tropical Depression: wind of 28–33 kt (51–62 km/h)
Tropical Disturbance: winds <28 kt ( <50 km/h).