The next major event as I have been mentioning for the past week is now in sight and it will be impacting large areas of QLD. This event has the potential to produce widespread heavy rainfall leading to flooding and also carries a severe weather risk for large areas of the eastern interior of the nation. The risk is also expanding further south coming into parts of NSW as well with some areas forecast to see well above normal rainfall once again which could also create flooding in areas recovering from the flooding at the end of Summer and through Autumn so far.
The southeast is cold today and the showery weather will ease with a frost risk the main problem that we need to watch over the northeast of VIC and southern and southeast NSW as well as across the ACT. Some areas clearly having their coldest weather so far this year and that will translate into the coldest nights of the year so far.
Warmer weather out west will continue to drive up the temperatures far above the average in a northwest flow this weekend into next week, with the next change on the board bringing widespread rainfall approaching from Tuesday. A large band of rain is forecast to develop over the SWLD during Tuesday night into Wednesday with the chance of thunderstorms and severe weather potential.
Temperatures will start to fall away over the in west next week, but in the east, after this cold outbreak, conditions will start to warm up with the northwest flow bringing in the moisture from the west and north, but lying-in wait for a lifting mechanism to utilise the moisture.
That may come in the form of a cold front tracking eastwards, with rainfall chances possibly increasing over SA from Thursday and the southeast states from Friday. This front and trough will help to kick the moisture and the long duration upper rain event out to sea with conditions improving for QLD next weekend.
Tropical areas feeling drier today and through the weekend but the moisture from QLD will return to the NT with the showers set to return next week, a sign of what the dry season is forecast to be like for 2022, interrupted and feeding rainfall events south and east through the nation.
Let's take a look.
Rainfall Next 10 Days
Rainfall is forecast to remain scattered to widespread over the southeast tonight and through Saturday with a low-pressure system meandering through Bass Strait, but the weather is forecast to ease rapidly as the system moves away. The showers decreasing and the air drying out further leading to a settled spell for the southern and southeast Ag Areas. For the northeast we are looking at widespread rainfall developing over the course of early next week with moisture which provides showery weather for the coast, moving inland, then connecting with the upper trough pushing in from the NT. Widespread rainfall with locally heavy falls is forecast to emerge from Tuesday through to Friday across the state with the heaviest of the rainfall; determined by the movement and orientation/evolution of the upper low. Rainfall could also clip the eastern portions of SA early to mid-next week. Rain with some moderate to heavy falls also likely to extend south into NSW and possibly as far south as the ACT. The weather remains dry over southeast areas including VIC during much of next week. A strong cold front over the SWLD from Tuesday may bring a band of moderate to heavy rainfall with windy weather and falling temperatures. Rainfall could be heavy enough for some areas to record their May average in a sitting. While the rain in the east begins to contract eastwards through the back half of next week, this may open the door for the rainfall in WA to come into SA and then VIC next weekend. So, two major rainfall events on the board may compete or complement each other, which will be key for falls becoming widespread for SA and VIC or being a bust for these areas.
Thunderstorm Forecast Saturday
A stalled boundary over QLD will continue to trigger showers and a few thunderstorms, no severe weather is expected. A few thunderstorms possible about northeast Arnhem Land. A departing low may send up another trough with the risk of hail and thunder in the showers.
Thunderstorm Forecast Sunday
Thunderstorms may start to develop through a large portion of inland QLD as an upper low begins to move towards the east. Thunderstorms at this time not expected to be severe but will watch trends. The severe weather threat from storms increases from early next week.
Thunderstorm Forecast Monday
Thunderstorms are forecast to become more widespread and extend south through the day and overnight into Tuesday through to NSW with heavy rainfall leading to flash flooding the main concern over inland QLD. The rest of the nation sits in stable air.
Thunderstorm Forecast Tuesday
Thunderstorms are forecast to continue over much of QLD, with storms possibly severe with heavy rainfall leading to flash flooding and damaging winds and large hail also quite possible given the sharp upper low. Heavy rainfall along the coast with thunderstorms may also lead to flash flooding. There is the chance of thunderstorms Tuesday night with the approach of a front over the southwest.
Thunderstorm Forecast Wednesday
Thunderstorms continue over the northeast of the nation and may begin to shift southwards into NSW and eastern SA as a deepening upper low moves slowly through southern and central QLD. Storms could be severe leading to heavy rainfall and flash flooding, damaging winds and large hail nearer the centre of circulation. Dangerous thunderstorms with a tornado risk is possible in the purple zone. The new front over in WA with a trough could lead to a band of rain and thunderstorms. Some storms there could produce heavy rainfall.
Severe Weather Watch - Tuesday through Friday
Flash and riverine flooding is possible next week as widespread rainfall falls over relatively wet catchments following months of above average rainfall. Rainfall rates could be heavy enough to cause renewed moderate flooding in some of the disaster zones.
Severe Weather Risk - Tuesday through Friday
A deepening upper trough which will likely cut off into an upper low will combine with deep moisture to produce widespread rainfall, some heavy through the inland with the risk of riverine and flash flooding. A separate trough over the coastal areas between Cardwell to Hervey Bay may trigger torrential rainfall through this period but the confidence is not high.
Flood Risk - Next Week
The flood risk is expected to increase through the middle to latter part of next week, especially the closer you are to the coast between Ayr and Bundaberg along the coast. A low to moderate risk extends well inland and will be connected to where heavy thunderstorms emerge.
Severe Weather Watch - Tuesday through Thursday
A large cold front with a tight thermal gradient, deepening moisture profile and strong upper-level trough will lead to widespread rainfall and strong to gale force winds moving through the region identified Tuesday night through Thursday.
Frost Risk Friday through Sunday Morning
Cold air trapped under high pressure combining with clear skies, dry air and light winds will assist in the formation of the first frost event of the season. No severe frosts are expected at this time.
SOUTHERN ANNULAR MODE - TURNING BACK TO NEUTRAL FROM SATURDAY
The SAM is expected to remain at positive levels through the coming days before heading back towards neutral values but in recent days, there are more members than not, suggesting the positive phase could persist into the back half of the month which could increase rainfall chances for the east and north again.
MEDIUM TERM - May 13th-20th 2022
Rainfall anomalies will continue to come down through the east as we see the drier air and more stable conditions move in and the full rain event now moves into the short term forecast so you will find near record rainfall values possible for QLD and well above average values for NSW. The rainfall increases over southern Australia through this period with the approach of a wave of low pressure and this connected to the moisture that is deepening via the Indian Ocean so this will place many areas in a wetter bias but not as heavy as what we are seeing over QLD and NSW in the short term. I am placing a slight drier bias over SA and into VIC to compensate for the error margin that could come with the moisture deviating away from the region during this time but it is low confidence forecasting for this period.
Temperature anomalies are forecast to remain below normal over the west of the country with the cooler and windy weather connected to the frontal weather in the west leading to widespread cloud and cooler air remaining trapped in the region. The weather is expected to remain warmer than normal over northern tropical areas with the weather more humid as well. The more seasonal weather is forecast to remain in place for most elsewhere though we could see some above average temperatures over the southeast and eastern inland in the downstream northwest flow that will be drawing in warmer air in advance of frontal weather moving east.
DATA - I will have the next video coming up on Sunday afternoon. Have a great weekend!
00Z GFS - Surface Pressure Pattern and Rainfall Distribution - Next 2 Weeks
The pressure pattern is looking more settled on the idea for the rain event to be heavy and lead to severe weather and flooding over parts of Central and Eastern QLD. This rain event will also bring in falls to NSW and the ACT but the rule of thumb is that the further south you come, the lighter and more patchy your falls will be. Some of the falls could exceed the average by a long margin from northern NSW into QLD next week. For the remainder of the nation the weather is settling down with a cooler airmass lingering over the southeast and eastern inland with morning frost and colder than average temperatures. Warmer weather over the west of the nation will become more of a feature through the central and then the southeast states as we move into the middle of next week as a front that brings some welcome rainfall to the SWLD of WA will help to draw in a northwest flow across the south of the country. The weather over the tropics also looks to dry out this weekend but then turn quite humid once again next week with a moist northeast flow redeveloping. Into the back of next week, will watch the trends on the models to see how the rain progresses east from WA into SA. Models hot and cold on that idea. The medium term offers more moisture streaming in from the northwest through to the southeast of the nation with moderate rainfall likely to spread into WA once again and then onwards to the east and southeast. The eastern inland of QLD and NSW should begin to clear though showery weather may continue along the coast through mid month.
00Z GFS - Precipitable Water Values - Next 2 Weeks
The main feature is found over the eastern inland of the nation now, with moisture increasing from the northeast and starting to erode that cooler and drier airmass that has infiltrated the south and east in recent days. So there will be a gradual increase in the rainfall chances as we move into the new working week with some significant falls and near record values being forecast over parts of the nation’s east with heavy rainfall developing. The rainfall is likely to be more patchy over the southeast but that moisture will reach the southeast inland with warming temperatures and more humid air compared to what we are seeing now. So the spell of frosty nights may end. Overall the atmospheric river may start up over the northern and western inland of the nation via the jet stream and this may start to spread across the nation’s south and east as we move through the medium term. We could also see further above average moisture content over the north of the nation return via northeast winds.
00Z GFS - Rainfall Accumulation - Next 10 Days
Rainfall event over the east and northeast is expected to dominate the short term and clear by this time next week. The showery weather over the southeast today and the easing conditions over TAS is forecast to move away this weekend with drier weather returning into the first half of next week. The rainfall over the SWLD is forecast to remain very much seasonal, this is thanks to the moisture spreading in from the west through the south. A cloud band is forecast to emerge, and rainfall may become moderate and heavy over the west of the nation and south of the nation mid to late next week. The rain band may begin to break down as it comes through SA and into the southeast inland of the country. The east should dry out later next week into the weekend.
00Z GFS - Rainfall Accumulation - Next 2 Weeks - Check video for state-based fly around.
Further rainfall is forecast to develop via the jet stream as the next wave of low pressure pushes through the southwest of the nation and this will spread throughout the southern and southeast inland of the country. This may offer better rainfall chances for southern Ag areas of the country. The eastern inland is forecast to dry out but showery weather may persist along the coast with onshore winds.
More weather information coming up on Saturday with the next broad video update coming up on Sunday afternoon heading into another working week from here in the northern tropics!