Spring 2022 NH / Fall 2022 SH Discussion Thread

Some thundery showers in the NW outer suburbs. Lucky folks, for their yards will be temporarily relieved from the ongoing drought.

We had some dime-sized (3/4") (1.7 cm) hail on Monday. It was only the second time I had seen hail in Norman, and the biggest hail I have seen here. We have gotten hail more than twice since I've lived here, but it's typically been when I'm in class or otherwise away from a window.

very cold day for May in the Northeast, looks even worse in Atlantic Canada. temps and dews



nationwide



700 hPa show an omega pattern

Meanwhile, it got up to 102°F (39°C) in Lubbock, TX today, with 3% relative humidity.

Cold again, high 12.8c, low 5.6c, mostly cloudless and sunny, dry.

Months' Worth Of Rain To Hit QLD This Week
(Source: Weatherzone )

A rare late-autumn deluge will inundate QLD this week, causing life-threatening flooding and significant transport disruptions across the state.

A sustained stream of atmospheric moisture feeding into a slow-moving upper-level trough will produce widespread and heavy rain across the state during the next 4 to 5 days.

This weather pattern is very unusual for May and some parts of the state could see several months’ worth of rain in a single day. The map below shows that a broad area of QLD could pick up more than 100 mm from this system and some areas could see more than 300 mm. Some areas of NSW will also see heavy rain later in the week.

Monday
Showers are starting to become more widespread over QLD today as the upper-level trough moves over central Australia, towards QLD.

Heavy falls are unlikely for most areas on Monday, although large parts of the state could see 5 to 20 mm and isolated pockets of more than 50 mm are possible.


Tuesday
Rainfall will become widespread and heavy as the upper-level trough moves over the stare from the west, with flooding through some inland districts. Some rain will also spread into northern NSW late in the day.

A severe weather warning has been issued for several districts in Central Western QLD due to heavy rain that is expected to start falling from Tuesday morning and continue throughout the day.

Daily rainfall totals of around 50 to 100 mm are likely across the central and northern inland of QLD, with isolated totals possibly reaching 150 to 200 mm. Some areas could also see six-hourly rain rates exceeding 100 mm with intense thunderstorms.

These rainfall rates may lead to life-threatening flooding, particularly across inland QLD where the ground is flat.


Wednesday
Heavy rain will continue across parts of inland QLD and northern NSW on Wednesday, while also spreading east towards the coast.

Widespread daily falls of 100 to 150 mm are forecast over the central and northern coast and inland, with totals possibly exceeding 250 mm in some areas. Six-hourly rainfall rates are likely to reach 60 to 120 mm and may exceed 150 mm in thunderstorms.

There is also potential for locally heavy rain to develop over parts southern QLD and northern NSW on Wednesday as tropical moisture starts to drift further south.


Thursday onwards

Rain is likely to continue over parts of QLD and NSW on Thursday and Friday, with more heavy rain targeting eastern QLD as a low-pressure system develops near the coast. However, there is some uncertainty regarding the position of the low and as a result, where the heaviest rain will fall.



The map below shows the forecast rainfall for Thursday and Friday from three different computer models, with some models suggesting heavy rainfall could shift south impacting parts of southeastern QLD.



This week’s rain is unseasonable for May and could impact industries and communities across both states that are not accustomed to these conditions at this time of year:



Flooding is likely to cause prolonged disruptions to transport routes and power networks



Low-lying parts of the landscape, such as mines, lakes and rivers, could become inundated by flash floods



Increased cloud cover will reduce solar power generation across parts of eastern Australia



Reduced visibility in heavy rain could affect aviation and port operations



It may become dangerous to travel at times, with life-threatening flash flooding a risk in some areas, both near the coast and in the outback



Any communities or industries in QLD and northern NSW should pay close attention to the latest forecasts and warnings throughout the week, as these will continue to be updated with the latest model data.

Effect of the ocean is very clear

Single digit dews again, this time further north

La Nina Not Letting Go
( Source: Weatherzone )


New data from the U.S. Climate Prediction Centre shows that La Niña is persisting in the Pacific Ocean at a strength not seen during May for more than two decades.
The temperature of the central equatorial Pacific Ocean – an area called the Nino 3.4 region – is one of the key indices used to monitor La Niña throughout the year. When sea surface temperatures inside the Nino 3.4 region are persistently lower than average, the Pacific Ocean is in a La Niña pattern.

The map below shows the current state of sea surface temperature anomalies in the Pacific Ocean, with the Nino 3.4 region highlighted by the blue box.


According to the U.S. Climate Prediction Centre (CPC), the Nino 3.4 sea surface temperature anomaly during the week ending on May 4 was -1.2ºC. This is the lowest weekly value observed by the CPC during May since 2000.

According to Australia’s Bureau of Meteorology, which uses a different baseline to calculate Pacific Ocean temperature anomalies, the weekly Nino 3.4 anomaly was -0.76ºC. This was also the lowest May value in the five years of data available on their website.

La Niña events typically begin in the Southern Hemisphere’s winter or spring, peak in spring and summer and break down in autumn. This year’s La Niña is remaining unusually well-established into the back end of autumn.

As a result, parts of northern and eastern Australia are continuing to experience persistent and heavy rain this week. Some areas in Queensland are currently under a severe weather warning for heavy rain and flood watches and warnings have also been issued across the state.


With La Niña struggling to loosen its grip in the Pacific Ocean, parts of Australia could continue to see above-average cloud cover and rainfall in the coming weeks.