tropicbreeze

A tropical low has developed in the northern Coral Sea Tropical Cyclone Outlook IDD10610 Tropical Cyclone Outlook for the Northern Region, including the Gulf of Carpentaria Issued at 2:15 pm CST on Friday 13 February 2015 for the period until midnight CST Monday 16 February 2015. Existing Cyclones in the Northern Region:Nil. Potential Cyclones: A tropical low is located in the northwest Coral Sea near Cape York and expected to remain slow moving till Sunday, before moving west into the Gulf of Carpentaria. The low will continue to develop as it moves towards the northeast coast of the Top End. Likelihood of a tropical cyclone in the Northern Region on: Saturday: Very low. Sunday: Low. Monday: Moderate. Global Models GFS Ensembles CMC Ensembles

It is quite amazing really, and fortunate Higos has kept clear of populated areas. Meantime this side of the equator has been very docile for a quite a while. But next week may change with a TC expected to develop near Christmas Island and another in the Gulf of Carpentaria. The monsoon trough has re-established itself along the north coast and things will likely quieten down north of the equator.

At 021200 UTC central pressure 974 hPa, wind speed (10 minute) 60 knots, tracking south south east at 9 knots, sea surface temperatures about 29C, vertical wind shear is high, outflow remains good to the south.

Ex-Eunice now, the system is really hurtling along at 35 knots. At 020600 UTC central pressure 972 hPa, wind speed (10 minute) 55 knots, radius of maximum winds 74 kms, tracking east south east at 35 knots. RMSC La Reunion won't be issuing any further advices. Next advice on this system will be issued by Perth Tropical Cyclone Warning Centre.

Ola has continued to intensify and has now been upgraded to a severe tropical cyclone. At 010600 UTC central pressure 965 hPa, wind speed (10 minute) 70 knots, tracking south south west at 2 knots, sea surface temperatures about 30C. Outflow is still good to the south but remains restricted elsewhere, vertical wind shear is moderate.

At 010600 UTC central pressure 965 hPa, wind speed (10 minute) 70 knots, radius of maximum winds 41 kms, tracking east south east at 20 knots. Lower sea surface temperatures and north westerly shear is causing a collapse of the deep convection in the northern sector. Looks like Eunice after extra tropical transition may catch up and merge with the ex-Diamondra.

At 310600 UTC central pressure 982 hPa, wind speed (10 minute) 50 knots, sea surface temperature about 30C, tracking south south east at 3 knots. Vertical wind shear is low and outflow is good southwards but restricted elsewhere. Wind speed of 60 knots is expected in 36 hours. RMSC Nadi Tropical Cyclone Warning Number 39 issued 0737 UTC Saturday 31 January 2015

At 310600 UTC central pressure 932 hPa, wind speed (10 minute) 110 knots, radius of maximum winds 15 kms, tracking east south east at 10 knots. Eunice is undergoing eye wall replacement. The surrounding environment is slowly deteriorating. In 48 hours the system should commence extra tropical transition.

The tropical low hanging around in the Coral Sea has moved slowly south east and is now north of New Caledonia. RMSC Nadi advised at 300600 UTC position near 16.8 S 161.6 E, central pressure 995 hPa, wind speed (10 minute) 25 knots, tracking south south east at 8 knots. Vertical wind shear is low, outflow to the north and south of the system is good, and sea surface temperatures are around 30C. The possibility of developing into a tropical cyclone within the next 24 hours is high.

It certainly is chugging along nicely now. RMSC La Reunion at 300600 UTC have the central pressure at 900 hPa, wind speed (10 minute) 130 knots, radius of maximum winds 20 kms. There's no indication of an eye wall replacement occuring any time soon. Currently at 68E the possibility of it reaching the Australian Western Zone still at tropical cyclone strength is becoming more likely.

At 291800 UTC central pressure 915 hPa, wind speed (10 minute) 125 knots, radius of maximum winds 19 kms, tracking south south east at 9 knots. Eunice has intensified rapidly, which is not unusual for cyclones with a small eye. They change rapidly in response to their surrounding environment. During Friday upper divergence equatorward is expected to weaken, however, poleward outflow remains good and vertical wind shear low. With a bit of a stretch Eunice might make it to the Australian Western Zone still at tropical cyclone strength. Although westerly shear is likely to set in the system should at that stage be accelerating eastwards effectively reducing the relative shear.

At 281800 UTC central pressure 968 hPa, wind speed (10 minute) 75 knots, radius of maximum winds 19 kms, tracking south east at 9 knots. Eunice is expected to peak in about 48 hours at 100 knots. At 1249 UTC and 1532 UTC there were indications of eyewall replacement occuring. Vertical wind shear remains weak until Sunday but then increasing shear and lowering sea surface temperatures should commence a weakening of the system.

At 281800 UTC central pressure 986 hPa, wind speed (10 minute) 45 knots, radius of maximum winds 83 kms, tracking east south east at 6 knots. In about 48 hours Diamondra should begin extra-tropical transition.

At 271800 UTC this system had a central pressure of 997 hPa, wind speed (10 minute) 30 knots, radius of maximum winds 56 kms, and moving east at 5 knots. Although yesterday predicting a peak intensity of 110 knots RMSC La Reunion now expects it to reach a peak of 90 knots in 60 hours. Cloud top temperatures of -89C and favourable conditions along the forecast track will assist early rapid intensification. Vertical wind shear is weak and should remain so for the next 5 days.

At 271800 UTC Diamondra had a central pressure 0f 990 hPa, wind speed (10 minute) 40 knots, radius of maximum winds 56 kms, and moving east south east at 5 knots. The LLCC is on the western edge of the deep convective activity. It's not expected to strengthen any further.

A few interesting comments from the Australian Bureau of Meteorology on TC Niko about its formation. Weekly Tropical Climate Note Issued 27 January 2015 Niko, first South Pacific tropical cyclone this season On 20 January, an area of low pressure near Tahiti developed to tropical cyclone strength and tracked south across French Polynesia. Tropical cyclone Niko was not especially strong nor did the centre of the storm pass over any islands, but it caused flooding and gale force winds over Tahiti from the storm's outer rain bands. Niko was unusual because tropical cyclones occur less frequently over the southeast Pacific compared with the southwest Pacific and usually only develop in El Niño years when sea surface temperatures in the region are warmer than normal. Sea surface temperatures across the tropical eastern Pacific Ocean, including the waters surrounding Tahiti, have been warmer than normal for several months and likely contributed to the cyclone's development. See the Bureau of Meteorology's ENSO Wrap up for official El Niño information. It is also likely that the Madden-Julian Oscillation (MJO) contributed to the favourable conditions for tropical cyclone Niko's development. Over the past week the MJO has been present, but weak, over the tropical Pacific Ocean. This placed the MJO in a location favourable for enhanced convection over the southeast Pacific. The MJO is forecast to remain subdued for the coming week and is not expected to be a major influence on tropical weather. See the Bureau's MJO Monitoring for more information on location and tracking of the MJO. The risk of tropical cyclone development across the South Pacific remains high while warmer than normal waters are present in the region. Next update expected by 3 February 2015 | Product Code IDCKGEW000

This system has been named Diamondra, it's actually one of three active systems currently in the central Indian Ocean. Central pressure 996 hPa, wind speed (10 minute) 35 knots, radius of maximum winds 46 kms, moving south west at 4 knots. It's now expected to peak in 48 hours at 55 knots.

It's great when the 'weather dice' fall just the right way. That evening started to look like a write-off with all the heavy cloud. But last minute the cloud over the horizon moved and all the nearer cloud was set ablaze. And I may be biased but silhouetted palm trees against a sunset just add a little bit of magic.

At 261800 UTC La Reunion has the system moving west south west at 9 knots. Central pressure 1000 hPa, wind speed (10 minute) 25 knots. In 48 hours it's expected to peak at 60 knots. Currently vertical wind shear is weak to moderate but should gradually increase after 48 hours.

So BOM reported a maximum of 46C. But then they were "caught out" By whom? Er ...... well, by BOM. So BOM "caught out" BOM "bending the truth". Some people! And following through on some of the links provided, this awesome example of intellectual dexterity stood out: John M 22. January 2015 at 21:10 | Permalink | Reply Interesting to compare the ABC’s matter-of-fact correction with the breathless original headline: “Alice Springs records its hottest day ever, mercury smashes 55-year record†Note the headline implying it was a mercury thermometer that recorded the record. (http://notrickszone.com/2015/01/22/alice-springs-automatic-weather-station-inflated-temperature-by-4-5c-producing-false-record-high/#sthash.8shMg7M9.MBhGcrir.dpbs) Talk about "implying"! Talk about desperation!

As at 23/0743 UTC wind speed is down to 45 knots now, central pressure 991 hPa. Vertical wind shear is moderate to strong, sea surface temperature about 26C. Further weakening is expected over the next 24 hours.

Overnight RSMC Nadi have revised their forecast putting the current speed at 50 knots but but not increasing over the next 36 hours, thereafter decreasing. Wind shear is moderate, outflow is restricted to the west but fair elsewhere.

Niko is now expected to weaken, in 12 hours to 40 knots, 24 hours to 35 knots.

Sunset tonight.

TROPICAL DISTURBANCE ADVISORY NUMBER A6 ISSUED FROM RSMC NADI Jan 22/0133 UTC 2015 UTC. TROPICAL CYCLONE NIKO CENTRE 991HPA [CAT 1] WAS LOCATED NEAR 17.2S 148.7W AT 220000 UTC. POSITION POOR BASED ON GOES EIR/VIS IMAGERY AND PERIPHERAL SURFACE REPORTS. CYCLONE MOVING SOUTH-SOUTHEAST AT ABOUT 09 KNOTS. MAXIMUM 10-MINUTE AVERAGE WINDS NEAR THE CENTRE ESTIMATED AT ABOUT 45 KNOTS. CONVECTION PERSISTENT AND ORGANISATION HAS IMPROVED SLIGHTLY IN THE PAST 24 HOURS. THE SYSTEM LIES IN A LOW SHEARED ENVIRONMENT AND MOVING INTO AN AREA OF INCREASING SHEAR. DIVERGENCE GOOD TO THE EAST OF THE SYSTEM. OUTFLOW GOOD IN EASTERN FLANK BUT RESTRICTED ELSEWHERE. CYCLONIC CIRCULATION EXTENDS UPTO 500HPA. DVORAK ANALYSIS BASED ON CURVED BAND WITH 0.60 WRAP YIELDS DT=3.0, MET=3.5, PT=3.0. FT BASED ON DT THUS YIELDS T3.0/3.0/D0.5/24HRS. GLOBAL MODELS HAVE PICKED UP THE SYSTEM AND MOVE IT SOUTH-SOUTHEAST WITH FURTHER INTENSIFICATION. FORECASTS : AT 12 HRS VALID AT 221200 UTC 18.9S 147.4W MOV SE AT 11 KT WITH 55 KT CLOSE TO CENTRE AT 24 HRS VALID AT 230000 UTC 21.1S 146.4W MOV SSE AT 11 KT WITH 60 KT CLOSE TO CENTRE OUTLOOK : AT 36 HRS VALID AT 231200 UTC 23.3S 145.7W MOV SSE AT 11 KT WITH 50 KT CLOSE TO CENTRE AT 48 HRS VALID AT 240000 UTC 25.5S 145.5W MOV SSE AT 11 KT WITH 35 KT CLOSE TO CENTRE THE NEXT TROPICAL DISTURBANCE ADVISORY ON TROPICAL CYCLONE NIKO WILL BE ISSUED AROUND 220800 UTC.