Since things are a little bit quieter across the United States right now, I want to start off this morning’s newsletter talking a bit about some major weather stories going on globally.
I want to first focus on the major flooding occurring in southeast Australia. This graphic from the Australian Bureau of Meteorology (BoM) shows rainfall in New South Wales over the last week, and you can see widespread amounts greater than 200 mm (~8”) in the region north of Sydney, with an area south of Port Macquarie having received more than 400 mm (~16”). Massive record flooding is occurring in this region, with three people confirmed dead and thousands of people evacuated or stranded; BBC reports people are being rescued by helicopter off rooftops.
Per the BoM, the rainfall has been the result of a persistent trough of low pressure along the New South Wales coast which has focused persistent heavy rainfall in the region, and as shown by the above BoM radar loop, heavy showers continue to stream across the region off the South Pacific. As a large upper level trough of low pressure develops and moves east toward the region, this weather pattern will finally break down over the next couple of days, easing the rainfall.
Meanwhile, persistent record heat continues in the Middle East and Japan, and as we have seen recently here in the US, record high minimums are where the greatest extremes are occurring with monthly records being broken in both regions.
Coming back stateside, a number of record warm temperatures - both minimums and maximums - were set yesterday in Texas and the Southeast to the south of the front that today will run from the Red River southeast into central Florida.
Meanwhile, in the Great Lakes and Northeast, much colder and damp conditions have become established. Muskegon, MI set a record low maximum temperature yesterday as they only reached 50F and a number of additional record low maximum temperatures are anticipated in the Northeast today. There will even be a bit of wintry precipitation today in higher elevations of upstate New York and northern New England.
The severe weather threat today will be primarily focused along the Red River region of north Texas and southern Oklahoma. A few waves of scattered severe storms capable of large hail - in some cases greater than 2” - along with damaging downburst winds and perhaps a tornado or two can be expected in this area through tonight.
Additional clusters of thunderstorms are expected to move southeast across the central United States Friday and Friday night, with a large area of marginal to slight (level 1-2 of 5) risks of severe storms. Heavy rainfall will also become a greater concern as repeated rounds of storms move across the same areas, and the Weather Prediction Center has a slight (level 2 of 4) risk of excessive rainfall in areas between Tulsa and Springfield, MO. Meanwhile, the Northeast and Great Lakes regions will continue to be damp and unseasonably cool.

For the Memorial Day weekend, a slow moving upper level weather disturbance will interact with the stationary front across the central part of the country to produce additional rounds of thunderstorms with a continued risk of severe weather. As rainfall continues to add up, flash flooding will become an increasing concern and by Sunday WPC has a large slight (level 2 of 3) risk of flash flooding from the Mid-Mississippi Valley across northeast Texas.
On Monday, the upper level system will continue to move east and begin to push the stationary front south, which will gradually push the focus for thunderstorm activity toward the Gulf Coast into the early and middle part of next week. Meanwhile, the western United States will start to heat up even more under a building area of high pressure aloft.