Tropical Cyclone Olga

[Cookie]

THE AREA OF CONVECTION PREVIOUSLY LOCATED NEAR 9.8S

162.2E, IS NOW LOCATED NEAR 11.5S 160.0E, APPROXIMATELY 130 NM SOUTH

OF HONIARA, SOLOMON ISLANDS. ANIMATED MULTISPECTRAL IMAGERY INDICATES

BROAD TURNING WITH A WESTERLY WIND SURGE NORTH OF THE SYSTEM AND

STRONG EASTERLY FLOW TO THE SOUTH OF THE SYSTEM. A 202218Z METOP-A

89 GHZ MICROWAVE IMAGE INDICATES CURVED BANDING AND A DEVELOPING LOW-

LEVEL CIRCULATION CENTER (LLCC). A 202218Z ASCAT PASS SHOWS A BROAD

CIRCULATION WITH 20 TO 25 KNOT WINDS OVER THE WESTERN SEMI-CIRCLE.

UPPER-LEVEL ANALYSIS INDICATES THAT THE SYSTEM IS LOCATED IN A

REGION OF STRONG TO MODERATE EASTERLY VERTICAL WIND SHEAR WITH

STRONG DIFFLUENCE ENHANCED BY AN UPPER-LEVEL TROUGH EAST OF

AUSTRALIA. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25

KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1003 MB.

THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL

CYCLONE WITHIN THE NEXT 24 HOURS REMAINS FAIR.

[Cookie]

[Somerset Squall]

The depression is now appears to be absorbing the remains of Neville as it moves briskly westwards towards the coast of the Cape York Peninsula. Strong shear will continue to effect the system, and although some strong convection is blowing up over the system, it is considered unlikely to become a TC in the hostile environment.

[Somerset Squall]

Well, against all odds, 04F has become a tropical cyclone, named Olga. Intensity is at 40kts currently. It appears that the massive blow up of convection has managed to persist long enough for the upgrade to cyclone status. Although sheared, Olga looks quite healthy in this respect currently.

Olga may strengthen over the next day or so before landfall, which is expected around Cairns. Shear should cap any major intensity gains but is not as strong as it was with Neville, so Olga may survive the journey to the coast. The remnant low of Neville is rotating around Olga at the moment, but should become absorbed soon. This shouldn't have any effect on Olga as the remnant low of Neville is much smaller. Even if Olga doesn't strengthen much more, she is a large cyclone capable of unleashing some very large rainfall totals so Olga needs to be closely watched.

[Cookie]

thanks for the updates mate

[Somerset Squall]

Olga has moved westwards towards the northeast coast of Queensland and has continued to intensify. Intensity is now at 55kts, and Olga has a pretty impressive central dense overcast feature which is indicative of a healthy storm and relaxation in shear. Olga is not far off landfall, and this is thought to occur midway between Cooktown and Cairns. Olga is still interacting with the remnant low of Neville, which has spun around the northern side of Olga and currently resides east-northeast of the cyclone. Olga is still expected to absorb ex-Neville soon. The result of this merger is unclear. BOM are expecting no effect, with Olga moving inland across the Cape York Peninsula (CYP) and decaying into a remnant low before limping into the Gulf Of Carpentaria (GOC). JTWC expect the merger to provide more energy for Olga to survive as a tropical cyclone for the duration of the passage over the CYP into the GOC. We shall see as always.

JTWC's scenario will put Olga into warm waters and low shear present in the GOC. This could allow for some rapid intensification if Olga gets this far. Therefore, the Top End of Australia need to be weary of Olga. Of primary threat of course is the CYP, where some flooding rains are already spreading inland.

This satellite image shows Olga and the remnant low of Neville (to the east-northeast):

Edited January 23, 2010 by Somerset Squall

[Somerset Squall]

The Fujiwhara interaction between TC Olga and the remnant low of Neville is amazing. I don't think it's going to be as clear cut as JTWC make out. Olga looks a little weaker now, but at the same time, the remnant low of Neville is becoming stronger, now located southeast of Olga. The new satellite image clearly shows the two dancing around each other:

Edited January 23, 2010 by Somerset Squall

[Cookie]

borrowed this from someone else

[Somerset Squall]

Nice image Cookie.

Olga has died a death this evening. The complex interaction with the remnant low of Neville never meant an easy forecast, but Olga was not expected to de-generate so quickly. The circulation is very messy now and intensity has fallen below TC strength. Olga has actually drifted southeastwards through the day, indicating the remnant low of Neville had some influence over the tropical cyclone. The two centres have now merged and what is left is a pretty poorly organised low with widespread messy convection. The chance still remains for Olga to re-organise in the GOC if it reaches this far, but the chances aren't so good now.

[Cookie]

thanks for the updates mate

[Somerset Squall]

The remnant low of Olga has moved westwards over the last couple days, inland across Queensland. It is currently located inland still, about 100 miles southwest of Mornington Island in the southern Gulf Of Carpentaria. Ex-Olga is moving parallel to the southern coast of the GOC, and is becoming better organised again as it pulls moisture in from the sea. Eventually, an approaching trough from the west should steer Ex-Olg northwards then northeastwards back over water. Here, the remnant low should find good conditions for development, with low shear and very warm sea temps. Therefore, there is a high chance Ex-Olga will become a tropical cyclone again beyond 24hrs.

[Somerset Squall]

Olga has regenerated in the southern Gulf Of Carpentaria, west of Mornington Island. Intensity has risen to 35kts again. Olga is right on the coast and should continue to move northwestwards into the hot waters of the Gulf. Sea temps are around 31-32C, and with low shear through the area, Olga could rapidly intensify. It loos likely that Olga will become stronger than in her first life, JTWC are forecasting a peak of 80kts- but don't be surprised if Olga becomes stronger than this.

The steering environment is complex, and the forecast track for Olga will no doubt chop and change over the enxt day or so. Current thinking is the steering ridge to the south currently steering Olga will break down to be replaced by one developing to the northwest of the cyclone. This will force Olga northeastwards towards the central gulf. Beyond the 48hr time frame, this ridge is expected to break down too, leaving the steering influence to a ridge to the northeast which will send Olga back towards the southeast and cause the cyclone to make landfall in the southeastern Gulf Of Carpentaria before eventually dissipating over central/southern Queensland. With three seperate steering ridges involved in the latest forecast, changes seem extremley likely and where Olga will go is far from certain. Interesting to watch!

[kold weather]

Its looking pretty good now it has to be said, gotta love the quirky tracks the Aussie systems tend to produce thanks interactions with the monsoonal trough as well asthe extra-tropical features that tend to be more potent generally in the Anartic region due to colder temps there.

Anyway as long as Olga does manage to get far enough into the GoC then conditions look very good and primed for decent strengthening, indeed you could well be right SS and the JWTC prediction of 80kts will be good if it stays close to the coast but if it goes further out into the gulf like it looks like it could possibly do then expect this to probably strengthen above 100kts, 2-3 days over those sorts of waters can do amazing things, however Aussie systems are even more difficult to forecast then Atlantic systems, probably the hardest to forecast in the world I'd imagine.

The JWTC latest call by the way is a perfect match of the 12z ECM, which isn't surprising becuase thus far its totally nailed Olga and its track.

[Cookie]

thanks for the updates

[Somerset Squall]

Olga has moved very slowly over the past 24hrs and has actually drifted southwestwards away from water. As a result, Olga has weakened to a 30kt tropical depression. It's not certain that Olga will make it at all to the Gulf Of Carpentaria now. With the southwestward drift, the anticipated turn to the east-northeast may not be enough. JTWC have ceased advisories on Olga, but BOM still have Olga skimming the southern GOC on the eastward track and intensifying to around 50kts before landfall back in Queensland. It certainly looks like any major strengthening will be highly unlikely now.

[Somerset Squall]

The remnant low of Olga has jogged northeastwards and is now pushing quickly in a due eastward direction. This has FINALLY taken the system back over water, and in response, deep convection is firing over the LLC. JTWC have issued a tropical cyclone formation alert on the system, and it appears Olga will reform for a third life this afternoon. Pressures observed at Mornington Island have been falling this morning, and the pressure at ex-Olga's centre is estimated to be 990mb and falling. This suggests that the system is responding well to being back over water. However, Olga doesn't have much time as an equatorial ridge to the northeast will send the low back to the southeast inland across Queensland within the next 24hrs.

What an utterly bizarre track! And a complete nightmare to forecast! Not often you have a system reform twice either (that's based on whether Ex-Olga does make it this afternoon, but chances are looking good)!

[Somerset Squall]

Olga has redeveloped again near Mornington Island, with intensity increasing to 35kts and pressure continuing to fall to around 988mb. Deep convection has become persistant over the LLC and banding features are wrapping into the circulation. However, Olga is just 6-12hrs away from yet anorther landfall, so has not got much opportunity to strengthen. With low shear and warm sea temps however, I would have thought Olga might reach about 45kts before the landfall occurs. Landfall is expected just west of Karumba, southwest Queensland. Olga is likely to continue to unleash flooding rains to the area, especially as the system has passed through this area already.

[Cookie]

really nuts track like you say.

[Cumulonimbus Tower]

Another take on what happened to Olga http://www.colinandrews.net/HAARP-3.html