Record Cold in the tropics

Seems like after the strong warmth in the tropics to near records standards for Winter in the tropics that HillyBilly pointed out 2 weeks ago or so now mother nature is trying to compensate with incredible low temps the past few days in the tropics mainly at night. Heres an article about it... From Weatherzone. Karl has already said he doesn't mind us doing this



Record cold hits the tropics

Tom Saunders, Saturday July 18, 2009 - 14:16 EST

Temperatures have plummeted across Queensland during the past three days causing frost to spread well north into the tropics.

Clermont in the Central Highlands plummeted to minus three degrees on Saturday morning, 10 degrees below their July average and the towns coldest night on record. Sub zero temperatures even spread as far north as Mt Isa, their coldest night in seven years. Even mild coastal areas have dropped to single figures over the past few nights with Rockhampton recording a minimum of just three on Saturday morning, colder than any night in central Sydney for more than 20 years.

The cold snap has resulted from a pool of very cold air from the Southern Ocean that moved north over eastern Australia during the week. The airmass has now moved out into the Tasman Sea which will allow temperatures to rise considerably over the next few days. By Tuesday Queenslanders will be bathing in highs as much as eight degrees above average.

- Weatherzone

Weatherzone 2009

Nights have turned chilly across (about) 20S with very dry air behind the "cold outbreak". Had a quick look at it seems Clermont is the only site to have set a record - rather oddly it dipped to -3.5C while most other sites were nearer 0C.

BTW watch for a rapid warm up in the west with high thickness values dropping south again.

Lots of 36C showing up in NW WA this afternoon. These numbers are typically within 1-1.5C of site records and within ~1.5C of the Australian July record (37.6C at Wyndham from 1996).

The extraordinary warmth/heat is definetly back up there for this time of the year.. What do you think could be a cause of this DJ? Lack of Strong Southerlies pushing through into the tropics this Winter? Or Warmer than normal ssts sitting to the NW of Australia?

Johnno, don't want to be alarmist but the blame fairly lies (IMHO) with global warming. We are seeing very frequently in inland arid regions runs at record highs. If you think about it - these regions have very low cloudiness and pretty benign synoptic forcing (just the occasional strong front/cloud/rainband) so have many opportunities in a year to set up nearly optimal conditions for extreme heat. When you add 1-2C to the average what would have previously been well short of a record suddenly gets close to being a record.... 34 becomes 35-36C (a big difference).

There are also weather changes (trends) going on - Australia has become less cloudy in recent decades in aut/win/spr and the weather patterns have tended more sluggish/anticyclonic. These would also tend to favour more hot extremes (though also - paradoxically some ripper frosts as drier, less cloudy conditions dominated by highs favours cold nights).

What worries me is that this extreme heat may well take a plunge south. There have been a few signs of this recently - the 24.9C in Mildura earlier in the week and the ~25C around Sydney. Quite a lot of places had early season record approached or broken. If we set up a long fetch NW'ly I would hate to think how hot it could get in Vic with all that extreme heat in residence. Of course, if could also stay up north... let's hope.

Max of 37.3 at Fitzroy Crossing on Friday, so 0.3C short of the all OZ record.

does the topic heading need to be changed?

Also what does early heat in the NW usually mean for the rest of the country in the following spring or summer seasons?