Tropical & Extra Tropical cyclone season 2017/18

[Cyclone Tracy]

EC ensemble 0304 12z becoming very interesting. Depression now becoming quite likely this weekend near Vanuatu with some runs are now showing a chance of U.S scale hurricane strength early to mid next week near Fiji.

Longer term, the main EC model projecting a classic extratropical cyclone Fujiwhara effect scenario around the NI

[Cyclone Tracy]

Tropical depression 13F currently has sustained winds around 30 knots and is moving into a very favourable environment east of Vanuatu. This could be a rapid intensification cyclone and be a significant threat within a few days around the Fijiian Islands.

[Nev]

TC Keni was named by RSMC Nadi just after 1am this morn. Central pressure 995 hPa...

TROPICAL DISTURBANCE ADVISORY NUMBER A10 ISSUED FROM RSMC NADI ON APRIL 081315UTC.

TROPICAL CYCLONE KENI WAS LOCATED NEAR 16.1S 170.1E AT 081200 UTC. POSITION POOR BASED ON HIMAWARI-8 EIR IMAGERY AND PERIPHERAL SURFACE REPORTS. CYCLONE MOVING NORTH AT ABOUT 5 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 35 KNOTS.

EXPECT WINDS ABOVE 33 KNOTS WITHIN 80 NAUTICAL MILES IN NE QUADRANT
AND WITHIN 50 NAUTICAL MILES IN SE QUADRANT
AND WITHIN 60 NAUTICAL MILES IN SW QUADRANT
AND WITHIN 60 NAUTICAL MILES IN NW QUADRANT.

DEEP CONVECTION HAS INCREASED IN THE PAST 12 HOURS WITH PRIMARY BANDS TRYING TO WRAP AROUND THE LLCC. CLOUD TOPS COOLING. ORGANISATION HAS IMPROVED SIGNIFICANTLY PAST 24 HOURS. CYCLONIC CIRCULATIONS EXTENDS UP TO 500HPA. SYSTEM LIES UNDER AN UPPER RIDGE WITH STRONG UPPER DIVERGENCE IN A LOW SHEARED ENVIRONMENT. SST AROUND 28 TO 29 DEGREES CELCIUS.
...

[Cyclone Tracy]

TC Keni now a severe tropical cyclone cat 3 on Fiji's door step.

[NZ Thunderstorm Soc]

Not again, they'll be saying

[Nev]

RSMC Nadi actually upgraded TC Keni to Cat 3 just after 7am this morn and has been battering Fiji's main islands for most of the day. Lowest pressure was 970 hPa, currently 978 hPa...

[Cyclone Tracy]

TC Keni current ADT method pressure at 956 hPa, 90 knots sustained at 4.52am NZT with eye closing over . Continued to strengthen through the night. Now racing at 25 knots into unfavourable shear.

[Cyclone Tracy]

TC Keni has now upgraded on Satcon and AMSU intensifcation methods as well. JTWC now having Keni fairly close to ADT method for pressure at 958 hPa at 6am NZT.

[Nev]

MetService has just downgraded TC Keni to Cat 2. LLCC now fully exposed with convection well sheared to the south. Should be fully extratropical by tonight…

WTNZ41 NZKL 110723
STORM WARNING 204
THIS AFFECTS OCEAN AREAS: SUBTROPIC AND PACIFIC
TROPICAL CYCLONE KENI 980HPA] CENTRE WAS LOCATED NEAR 27.8 SOUTH
173.2 WEST AT 110600 UTC.
POSITION GOOD.
REPEAT POSITION 27.8S 173.2W AT 110600 UTC.
CYCLONE IS MOVING SOUTHSOUTHEAST 30 KNOTS.
EXPECT SUSTAINED WINDS OF 60 KNOTS CLOSE TO THE CENTRE EASING TO 45
KNOTS BY 111800 UTC AND THEN EASING TO 40 KNOTS BY 120600 UTC WITH
HIGH TO VERY HIGH SEA AND MODERATE TO HEAVY SWELL EASING.
EXPECT WINDS OVER 47 KNOTS WITHIN 90 NAUTICAL MILES OF CENTRE IN THE
EASTERN SEMICIRCLE AND WITHIN 60 NAUTICAL MILES OF CENTRE IN THE
WESTERN SEMICIRCLE.
EXPECT WINDS OVER 33 KNOTS WITHIN 190 NAUTICAL MILES OF CENTRE IN
THE EASTERN SEMICIRCLE AND WITHIN 110 NAUTICAL MILES OF CENTRE IN
THE WESTERN SEMICIRCLE WITH VERY ROUGH SEA AND MODERATE TO HEAVY
SWELL.
FORECAST POSITION NEAR 34.9S 169.1W AT 111800 UTC
AND NEAR 45.1S 167.9W AT 120600 UTC.
THIS WARNING CANCELS AND REPLACES WARNING 196.

[Nev]

The South Pacific/Coral Sea Tropical Cyclone Season officially ended yesterday with just 7 named TC's (incl. 3 severe), less than NIWA's seasonal prediction of 8-10 TC's and the 1981-2010 average of 10.4 TC's. However, the remnants of 2 of those (Fehi and Gita) crossed directly over NZ, while another (Hola) closely brushed the east coast of the North Island. Still more than previous season's 4 named TC's though, 2 of which occurred in May.