A deepening low pressure trough over eastern Australia is contributing to an intensification of heavy rainfall through parts of NSW and QLD, adding to the threat of both flash flooding and riverine flooding. Northeastern parts of NSW and the southern inland of Queensland are two areas that have already seen heavy falls over the past 48 hours. St George in southern Queensland has recorded over 120mm of rain since 9am on Tuesday, with close to 90mm of this in the past day. In NSW, Moree has accumulated over 150mm since 9am on Tuesday, while Tamworth and Narrabri have both recorded more than 100mm in the past 24 hours. These falls come on the back of significant rainfall in the previous week, so catchments are saturated, and many rivers are already in flood. Most river systems across northeastern NSW and southern Queensland are experiencing at least minor to moderate flooding, but there are now a growing number reaching the major flood threshold. The Gwydir and Mehi rivers are both under a major flood warning following the heavy falls in the Moree region. Major flooding is expected through Gravesend and Moree during Thursday and Friday. For Moree the expectation is for a flood peak on Friday morning slightly above that seen in the November 2011 floods. Major flooding is also expected along the Paroo River over the next week, with flood peaks pushing from QLD into NSW. Major flooding can also be expect on the Balonne River, especially downstream from St George. Major flooding is also occurring on the Warrego River, although for Charleville the current expectation is for a moderate flood peak of 5 metres on Friday. Flash flooding is also going to be a considerable risk through the remainder of today and Friday morning, with a deep low pressure trough remaining slow-moving across both NSW and QLD. Severe weather warnings for heavy rainfall have been issued in both states, with the NSW warning currently covering many northern, central and eastern districts. The warning even includes heavily populated areas such as Newcastle, Sydney and Wollongong. Southern and central inland districts of Queensland are covered by a similar warning. The low pressure trough that is triggering the heavy rain will gradual weaken during Friday and tend to push off the coast on Saturday. This will allow a substantial easing of rainfall on the weekend, with relatively dry conditions then forecast into the start of next week. This break in the rain will be welcome but the next 24-36 hours will remain a period of concern as heavy falls set in.