Special Update

Further Update Saurday, please check blog. Quick Update SA trough with showers and isol thunderstorms May 24-25th 2022 G’Day everyone, just a quick little update on the first system in the sequence of many over the next week or so. Currently we have a trough moving through the Bight and West Coast District which is the same system that barrelled viciously through SW WA yesterday delivering squally showers and thunderstorms including a tornado out over the wheatbelt showing the powerful dynamics at play. The system as expected has begun to weaken but has managed to bring down some moisture from the warming Indian ahead of it, evident by the cloudband that is present over Central and Eastern SA (1030pm local on 24th). Now if you had your eye on the sky over the past few days you would have noted quite a bit of surfaced based convection around during the late mornings and early to mid-afternoons and this was due to the NE flow bring in moisture out of the very damp eastern seaboard. This little extra moisture will help dilute the weakening and sliding factor of the current trough and allow scattered showers and isolated thunderstorms to re-develop tomorrow afternoon over the Mallee and eastern districts in general with a little bit of solar heating. Initially though, showers and thunderstorms over the West Coast with patchy light rain ahead extending eastwards overnight. The cluster of showers and thunderstorms will gradually spread to more isolated thunderstorms and patchy rain areas by the early morning tomorrow (25th) over Central Districts so the West Coast and western Eyre Pen will see the greatest thunderstorm activity tonight. Due to the convective nature of the system, there will be more holes than Swiss cheese for the rainfall totals with a range anywhere from 1-15mm likely. Thunderstorms over the West Coast though could yield up to 25mm tonight. Beyond tomorrow, we will see a couple of weak troughs waffle in from the W/SW in an onshore flow keeping some isolated to scattered showers going at times, chiefly afternoons. A cold front is then expected to cross from the W/SW again on saturday with a band of showers and isolated thunderstorms however this front will weaken quickly and lack penetration. Heavier showers are likely over KI and the southern and western portions of the Fleurieu, especially with any isolated thunderstorms. More significantly however is the strong cold front and associated upper trough due later sunday which I touched on during the May update a week ago. Powerful jetstream dynamics will be present with this system and severe weather is likely including cold and windy conditions which will warrant sheep graziers alerts as well as damaging wind warnings. It is the sort of system where cold air tornadoes are ‘somewhere’ along the frontal boundary or organised convective lines immediately behind it. A deep and unstable pool of cold air will blast in behind the front driving squally showers, cold air thunderstorms, possible small hail through Monday and Tuesday with significant rainfall totals accumulating about the ranges and elevated terrain. The rain shadow effect though will be fairly strong given the westerly nature at first and strong winds though the main frontal band and stronger cold air lines will have more punch east. I will issue a second update for that system late saturday with greater detail. Rainfall: For now, rainfall will be extremely patchy until the bigger system arrives later sunday but generally 5-12mm for all districts with the exception of parts of NE EP, parts of the Upper North and some holes in the Mallee where 3-5mm is more likely. Scattered totals to 15-20mm are more likely over the West Coast and Adelaide regions with isolated totals to 25-30mm over the Adelaide Hills. Link to temporary blog website: https://farmweathersa.blogspot.com/ Happy Farming and Cheers from The Weatherman *Note – For interest only, all thoughts are of The Weatherman and may not be reproduced without my consent.